JP2010204673A - Image display, projector, and image adjusting method of image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display in which a desired image adjustment region can be selected out of the display images and the image of the selected adjustment region can be adjusted after the gradation property of a whole image is confirmed, a projector, and the image adjusting method of an image display. <P>SOLUTION: An image signal processing part 16 makes an image stand still when an operation performing image adjustment is performed, and makes a display part display a selection cursor 51 for selecting a desired image region on an image. Further, the image signal processing part 16, when an operation for selecting an image region by the selection cursor 51 is performed, flickers an adjustment point corresponding to gradation of the selected image region or superposes a property confirmation screen in which color tone of an adjustment point is changed on the image signal, and accordingly, the position of the image region in the gradation property of the whole image is clearly expressed by a graph. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image display device that displays an image represented by an image signal, a projector, and an image adjustment method for the image display device.

2. Description of the Related Art Image display devices that can switch the gradation characteristics of an image represented by an image signal according to the content of the projected image and the projection environment are known. For example, the projector of Patent Document 1 has three types of image quality adjustment options “dynamic”, “natural”, and “soft”, and stores γ values that are gradation characteristic data corresponding to the respective adjustment items. ing. The projector sets a γ value according to the selected adjustment item, and performs gradation correction (hereinafter also referred to as “γ correction”) on the image signal.
In such a general projector, an image that has been γ-corrected according to the selected adjustment item is projected onto a screen after an operation for determining the selection content (hereinafter referred to as “determination operation”). .

  In addition, for example, in an image representing a photograph of a person, a specific image part in the display image is selected and the image adjustment to the part is performed, for example, when the gradation value of the background part is to be adjusted to make the person stand out. There was a need to do. Furthermore, there is a need from an advanced user who has specialized knowledge to check the gradation characteristics of a display image with a graph and to achieve gradation characteristics suitable for the image. Incidentally, in order to perform image adjustment on such a partial image, it is necessary to review the setting of the γ value itself that is the gradation characteristic data.

JP-A-2005-99620

However, in the conventional image display device, there was only the discretion of image adjustment such as selection from a small number of predetermined adjustment items.
Therefore, even if there is an image part that the user wants to perform image adjustment in the displayed image, it is difficult to select the part itself. Even if the image part where the image adjustment is desired can be selected, the output gradation level at the point of the gradation characteristic corresponding to the gradation value of the image part can be adjusted, and the graph showing the gradation characteristic of the image It was difficult to confirm.
As described above, in the conventional image display device, it is difficult to select a specific image adjustment portion in the display image and to adjust the image of the image portion with a point after confirming the graph indicating the gradation characteristics. There was a problem.

  In order to solve the above problems, in the present invention, a desired image adjustment part can be selected from the display image, and after confirming the gradation characteristics of the entire image, the image of the selected adjustment part can be adjusted. An object of the present invention is to provide an image display device, a projector, and an image adjustment method for the image display device.

  In order to achieve the above object, according to an image display device of the present invention, an image display device that displays an image represented by an image signal on a display unit, for selecting a desired image portion on the image. In order to adjust the gradation for each of a plurality of adjustment points in the gradation characteristic of the image, and the characteristic confirmation screen including the selection cursor and the graph indicating the correlation between the gradation characteristic input and output gradation level in the initial setting of the image An OSD unit that superimposes the gradation adjustment screen on the image signal, an operation for starting adjustment of at least the gradation characteristics of the image, an operation for selecting an image part using a selection cursor, and an operation for determining the selected image part. When an operation for performing image adjustment including adjustment of gradation characteristics on the image signal is performed and the operation adjustment is performed on the operation unit, the image is stopped and the OSD unit And an image signal processing unit that displays a selection cursor on the display unit, and the OSD unit corresponds to the gradation of the selected image part when the operation part is operated to select the image part by the selection cursor. When the operation to determine the selected image part is performed on the operation part by superimposing the characteristic confirmation screen with the adjustment point blinking or changing the color tone of the adjustment point on the image signal, and the gradation of the selected image part A gradation adjustment screen of adjustment points corresponding to is superimposed on the image signal.

According to this configuration, when an operation for performing image adjustment is performed, the image signal processing unit stops the image and causes the display unit to display a selection cursor for selecting a desired image portion on the image. Therefore, if the image is a moving image, it is difficult to select an image part because the image changes, but it is easy to select by making the image still. Furthermore, a desired image part can be selected from the still images with a selection cursor.
The OSD unit displays a characteristic confirmation screen that blinks the adjustment point corresponding to the gradation of the selected image region or changes the color tone of the adjustment point when the operation unit is operated to select the image region with the selection cursor. Since the image signal is superimposed, the position of the image portion in the gradation characteristics of the entire image is clearly shown on the graph. Therefore, the adjustment point in the gradation characteristics of the entire image can be confirmed on the graph before the gradation adjustment.
Further, the OSD unit superimposes the gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image part on the image signal when the operation part determines the selected image part. The tone adjustment screen can be used to adjust the gradation of the selected image portion.
Therefore, the image display apparatus of the present invention can select a desired adjustment part from the display image, and can adjust the image of the selected adjustment part after confirming the gradation characteristics of the entire image.

  According to the image display device of the present invention, the image signal processing unit includes a plurality of basic gradation characteristics that are predetermined in order to make the gradation characteristics unique to the display section suitable for at least the installation environment. A gamma correction unit for correcting to any one of the basic gradation characteristics, a gradation point adjustment unit for adjusting an output gradation value for each of a plurality of adjustment points provided in accordance with an input level in the basic gradation characteristics, The gradation adjustment to the image signal by the image signal processing unit is performed by the gradation characteristic obtained by combining the gradation correction in the gamma correction unit and the gradation adjustment in the gradation point correction unit, and is selected. When the output gradation value is adjusted on the adjustment point gradation adjustment screen, the gradation point adjustment unit preferably changes the output gradation value of the adjustment point according to the adjustment content.

The image signal processing unit corrects a tone characteristic specific to the display unit to any one of a plurality of basic tone characteristics determined in advance so as to be suitable for at least the installation environment. A gamma correction unit for adjusting the output gradation value for each of a plurality of adjustment points provided in accordance with the input level in the basic gradation characteristics, so that each function is independent. This is done with dedicated components. Therefore, since each structure can be dedicated, it can be set as a simple structure.
Further, the gradation adjustment to the image signal as the image signal processing unit is performed by gradation characteristics obtained by combining the gradation correction in the gamma correction unit and the gradation adjustment in the gradation point correction unit. Depending on the part, advanced gradation adjustment can be performed.
In addition, when the output gradation value is adjusted on the gradation adjustment screen of the selected adjustment point, the gradation point adjustment unit changes the output gradation value of the adjustment point according to the adjustment content. The image on the back of the gradation adjustment screen is updated to an image reflecting the adjustment contents in real time.
Therefore, according to the image display device of the present invention, advanced gradation adjustment is possible with a simple gradation adjustment configuration, and an image reflecting the adjustment contents can be confirmed in real time.

  According to the image display device of the present invention, the selection cursor includes a pixel selection unit having a size for selecting a plurality of continuous pixels of three or more pixels in the pixels of the display unit, and the selected image part. The gradation characteristic adjustment point corresponding to is the average value of the gradation values for each of the plurality of pixels selected by the pixel selection unit, or the maximum and the gradation value for each of the plurality of pixels selected by the pixel selection unit. It is preferable that the adjustment point of the input gradation level closest to the average value excluding the minimum gradation value is selected.

According to this configuration, since the selection cursor is configured to include a pixel selection unit having a size for selecting a plurality of consecutive pixels of three or more pixels in the pixels of the display unit, a plurality of pixels having a width The selected part intended by the user can be determined based on the pixel data at.
Further, the adjustment point of the gradation characteristic corresponding to the selected image part is the average value of the gradation values for each of the plurality of pixels selected by the pixel selection unit, or for each of the plurality of pixels selected by the pixel selection unit. Since the adjustment point of the input gradation level that is closest to the average value excluding the maximum and minimum gradation values in the gradation value is selected, the influence of the pixel data including noise is reduced, and the user intends It is possible to select an adjustment point corresponding to the selected image part.
Therefore, the image display apparatus of the present invention can accurately select the adjustment site intended by the user from the projected image.

  According to the image display device of the present invention, it is preferable that the pixel selection unit has a size for selecting a total of nine pixels in a square shape composed of three pixels in the vertical and horizontal directions.

According to this configuration, the pixel selection unit has a size for selecting a total of 9 pixels in a square shape composed of 3 pixels in each of the vertical and horizontal directions, and therefore, when taking the average value except for the pixels with the maximum and minimum gradation values Even so, effective pixel data of 7 pixels is obtained. Moreover, since it becomes a moderate size in the whole image, it is easy to visually recognize it, and since it is a square shape, it is easy to select an image part.
Therefore, the image display apparatus of the present invention can easily and accurately select the adjustment site intended by the user from the projected image.

  According to the image display device of the present invention, the selection cursor further includes an annular portion including a shape obtained by enlarging a part of the outer shape of the pixel selection portion around the outer periphery of the pixel selection portion, and the annular portion is always It is preferable to keep the relative position with the pixel selection unit and move on the still image together with the pixel selection unit.

According to this configuration, the selection cursor further includes an annular portion including a shape obtained by enlarging a part of the outer shape of the pixel selection portion around the outer periphery of the pixel selection portion, and the annular portion is always connected to the pixel selection portion. Since the relative position is maintained and the pixel selection unit moves on the still image, the selection cursor has a characteristic form having an annular portion that is slightly larger than the pixel selection unit, and is displayed larger and clearly on the image.
Therefore, it is easy to select a desired image part by a clearly displayed selection cursor.
Therefore, according to the image display device of the present invention, it is possible to easily select a desired image portion with the selection cursor clearly displayed on the image.

  According to the image display device of the present invention, in the selection operation of the image part by the selection cursor, the position of the image selection unit is controlled by the image signal processing unit so that the entire image selection unit does not protrude from the still image, When the image selection unit reaches the edge of the still image, the selection cursor is preferably displayed in a state where a part of the image of the annular portion protruding from the still image is missing.

According to this configuration, the position of the image selection unit is controlled by the image signal processing unit so that the entire picture of the image selection unit does not protrude from the still image, and when the image selection unit reaches the edge of the still image, the selection cursor Is displayed in a state where a part of the annular portion protruding from the still image is missing, it is possible to select an image up to the image part of the edge of the image with the selection cursor. Even when the edge of the selection is selected, the selection cursor can be visually recognized.
Therefore, the image display apparatus of the present invention can select a desired image part in all the effective image areas with the selection cursor.

  According to the image display device of the present invention, the color tone of the selection cursor is set to either white or black, and the OSD unit selects either the color tone of the image part selected by the selection cursor and either white or black. It is preferable to adjust the color tone of the selection cursor to the color tone having the higher contrast with the color tone.

According to this configuration, the OSD unit adjusts the color tone of the selection cursor to the color tone having the higher contrast between the color tone of the image portion selected by the selection cursor and the color tone of either white or black. The color tone of the selection cursor is adjusted so as to be a color tone that is easy to visually recognize.
Therefore, it is easy to select a desired image part by a clearly displayed selection cursor.
Therefore, according to the image display device of the present invention, it is possible to easily select a desired image portion with the selection cursor clearly displayed on the image.

  According to the image adjustment method of the image display device according to the present invention, the display unit for displaying the image represented by the image signal, the selection cursor for selecting a desired image part on the image, and the initial setting of the image An image signal includes a characteristic confirmation screen including a graph representing the correlation between the input of the gradation characteristics and the output gradation level, and a gradation adjustment screen for adjusting gradations at a plurality of adjustment points in the gradation characteristics of the image. An OSD unit to be superposed, an operation unit for performing at least an operation for starting adjustment of the gradation characteristics of the image, an operation for selecting an image part using a selection cursor, and an operation for determining the selected image part, And an image signal processing unit that performs image adjustment including adjustment of tonal characteristics, wherein the image is stopped when an operation for performing image adjustment is performed. In addition, when the selection cursor is displayed on the display unit and an operation for selecting an image part by the selection cursor is performed, the adjustment point corresponding to the gradation of the selected image part blinks or the color of the adjustment point is changed. When the step of superimposing the changed characteristic confirmation image on the image signal and the operation of determining the selected image part are performed, the gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image part is displayed on the image signal. And the step of superimposing on.

According to this image adjustment method, when an operation for performing image adjustment is performed, the image is stopped and the selection cursor is displayed on the display unit. Therefore, when the image is a moving image, the image changes. For this reason, it is difficult to select an image part, but it is easy to select by making the image stationary. Furthermore, a desired image part can be selected from the still images with a selection cursor.
When an operation of selecting an image part with the selection cursor is performed, a step of superimposing a characteristic confirmation screen on the image signal, blinking the adjustment point corresponding to the gradation of the selected image part or changing the color tone of the adjustment point Therefore, the position of the image part in the gradation characteristics of the entire image is clearly shown in the graph. Therefore, the adjustment point in the gradation characteristics of the entire image can be confirmed on the graph before the gradation adjustment.
Further, when an operation for determining the selected image part is performed, the gradation adjustment screen includes a step of superimposing the gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image part on the image signal. Thus, the gradation adjustment of the selected image portion can be performed.
Therefore, according to the image adjustment method of the image display device of the present invention, a desired adjustment part can be selected from the display image, and after checking the gradation characteristics of the entire image, the image of the selected adjustment part is adjusted. can do.

FIG. 3 is a diagram illustrating one usage mode of the projector according to the first embodiment. 1 is a schematic configuration diagram of a projector. (A) The figure which shows an example of the input-output characteristic of a gradation point adjustment part. (B) A table showing the gradation amount per step for each adjustment point. (A) The graph which shows an example of the VT characteristic of a liquid crystal light valve. (B) The graph which shows an example of the input-output characteristic of a gamma correction part. (A) The enlarged view of the selection cursor in 1 aspect. (B) The figure which shows the one aspect | mode of the selection state of the image site | part by a selection cursor. The flowchart which showed the flow of the image adjustment to a branch screen. (A) The figure which shows the one aspect | mode of a selection screen. (B) The figure which shows the one aspect | mode of a branch screen. The flowchart which showed the flow of the image adjustment in cursor adjustment mode. (A) The figure which shows the one aspect | mode of a characteristic confirmation screen. (B) The figure which shows the one aspect | mode of a gradation adjustment screen. (A) The figure which shows the one aspect | mode of a characteristic confirmation screen. (B) The figure which shows the one aspect | mode of a continuation confirmation screen. The figure which showed the one aspect | mode when the operation screen is superimposed and displayed on the image. The flowchart which showed the flow of the image adjustment in graph adjustment mode. (A) The figure which shows the one aspect | mode of a characteristic confirmation screen. (B) The figure which shows the one aspect | mode of a gradation adjustment screen. (C) The figure which shows the one aspect | mode of a characteristic confirmation screen. 9 is a flowchart showing a flow of image adjustment up to a branch screen in the second embodiment. (A) The figure which shows the one aspect | mode of a selection screen. (B) The figure which shows the one aspect | mode of a branch screen. The flowchart which showed the flow of the image adjustment in cursor adjustment mode. (A), (b) The figure which shows the one aspect | mode of a graph adjustment screen. (C) The figure which shows the one aspect | mode of a continuation confirmation screen. The flowchart which showed the flow of the image adjustment in graph adjustment mode. (A), (b) The figure which shows the one aspect | mode of a graph adjustment screen.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)
<Projector overview>
FIG. 1 is a diagram showing one usage mode of the projector according to the first embodiment of the present invention. A projector 100 as an image display device projects an image based on an image signal supplied from an image signal supply device 200 such as a personal computer onto a screen SC.
As an image adjustment function, the projector 100 is a “color mode” that accentuates a reference γ characteristic, which is a basic gradation characteristic of an image, in order to enhance the expressive power of the image according to the content of the image and the projection environment. It has an image adjustment function including adjustment and “gamma” adjustment for selecting a reference γ characteristic from among a plurality of options stored in advance.

In the “gamma” adjustment, the basic γ characteristic includes a “custom” characteristic. When the “custom” characteristic is selected, a mode in which the gradation characteristic can be customized for each adjustment point is entered. In this “custom” characteristic, the reference γ characteristic itself, that is, the gradation characteristic itself can be customized.
The projector 100 has a function of selecting a desired image part from the projected image for determining an adjustment point to be customized, which is necessary for customizing the gradation characteristics, and a level of the image part that is the selected adjustment point. It has a function for adjusting keys.
For example, in the case of FIG. 1, the background image part of the lower left person in the projected image on the screen SC is selected by the selection cursor 51 for selecting the image part. When the selected image region is confirmed, an adjustment screen for adjusting the gradation of the image region is displayed through a confirmation step or the like.

In addition, in the “gamma” adjustment function, in addition to the “cursor adjustment mode” in which adjustment is started by selecting a desired image portion with the selection cursor 51, a graph showing the gradation characteristics of the entire projected image is displayed. There is also a “graph adjustment mode” in which gradation adjustment is performed by selecting an adjustment point corresponding to the gradation level to be adjusted from the graph. In the “graph adjustment mode”, the gradation of the image portion corresponding to the input gradation level of the selected adjustment point is adjusted.
The operation of the projector 100 including the selection of these functions and the adjustment mode and the adjustment operation is performed by the operation unit 1 provided on the top of the projector 100 placed on the desk or the remote controller 2.
The projector 100 is not limited to being installed on a desk, and for example, may be configured such that the projector 100 is installed on the ceiling and operated by the remote controller 2.

<Projector configuration>
FIG. 2 is a schematic configuration diagram of the projector of the present invention. Here, a schematic configuration of the projector 100 for realizing an image adjustment function such as “gamma” adjustment will be described with reference to FIG.
The projector 100 separates the light emitted by the lamp 3 as the light source unit into the three primary color components of red light, blue light, and green light, and each color light liquid crystal light valve 5R as a display unit for each color light. This is a so-called “liquid crystal three-plate projector” that modulates 5G and 5B according to the image signal and enlarges and projects the full-color modulated light synthesized again onto the screen SC by the projection lens 7. The liquid crystal light valves 5R, 5G, and 5B are light modulation elements, which are provided for red light, green light, and blue light, respectively, and are included in the configuration of the optical unit 4.

The projector 100 includes an operation unit 1, a remote control 2, a lamp 3, an optical unit 4, a projection lens 7, a control unit 10, an operation receiving unit 11, a power supply unit 12, a lamp driving unit 13, a storage unit 14, an AD converter 15, an image signal. The processing unit 16, the image signal correction unit 25, the liquid crystal panel driving unit 26, and the like are included.
The operation unit 1 includes a plurality of operation buttons for operating the projector 100. The plurality of operation buttons include a “power button” for starting and shutting down the projector 100, a “Menu button” for displaying various operation menus, a “Select button” for determining a selected content, “Esc button” for returning to the previous operation screen, “↑ button”, “↓ button”, “→ button”, “← button”, etc. for selecting options and increasing / decreasing the gradation for each step include. Note that “↑ button” and “↓ button” are described as a set, and “up and down button”, “→ button”, and “← button” are described as “left and right buttons” as a set. The “up / down buttons” and “left / right buttons” function as a plus button and a minus button, respectively, depending on the mode of the operation screen.
The remote controller 2 is a remote controller for remotely operating the projector 100, and includes a “γ adjustment button” for directly entering the gradation adjustment mode in addition to a plurality of operation buttons similar to those of the operation unit 1.

The lamp 3 is, for example, a discharge lamp capable of obtaining high brightness such as a high-pressure mercury lamp, a metal halide lamp, and a halogen lamp.
The optical unit 4 separates the light emitted from the lamp 3 into light having a stable luminance distribution and the light having a stable luminance distribution into light components of the three primary colors red, green, and blue. Then, a separation optical system that supplies the liquid crystal light valves 5R, 5G, and 5B for each color light, and a combination optical system that combines again each color light modulated according to the image signal for each color light by the liquid crystal light valve. (Both not shown).
The projection lens 7 expands the full-color modulated light emitted from the optical unit 4 and projects a full-color image on the screen SC.

The control unit 10 is a CPU (Central Processing Unit), and exchanges signals with each unit via the bus line Bus.
When an operation is performed on the operation unit 1 or the remote controller 2, the operation reception unit 11 receives the operation and sends an operation signal serving as a trigger for various operations to the control unit 10.
The power supply unit 12 is stabilized by guiding the AC power from the external power supply 210 from the plug and performing transformation, rectification, and smoothing by a built-in AC / DC conversion unit (both not shown). A DC voltage is supplied to each part of the projector 100.
The lamp driving unit 13 is supplied with power from the power supply unit 12 and generates a high voltage to turn on the lamp 3 to form a discharge path, and to maintain a stable lighting state after lighting. A ballast circuit (both not shown) is included.

The storage unit 14 is configured by a non-volatile memory capable of rewriting data, such as a flash memory or an FeRAM (Ferroelectric Random Access Memory). The storage unit 14 includes a startup program that defines the sequence and contents for starting up the projector 100, and a “gradation characteristic adjustment program” for correcting the gradation characteristics of the image signal according to preferences. Various programs for controlling the operation and accompanying data are stored. The accompanying data includes a plurality of γ correction data corresponding to the VT characteristics indicating the correlation between the input voltage level of each of the liquid crystal light valves 5R, 5G, and 5B measured in the manufacturing stage of the projector 100 and the light transmittance. Is remembered.
The AD converter 15 is an AD converter and includes a decoder (not shown). The AD converter 15 adjusts the analog image signal Vin of various formats supplied from the image signal supply apparatus 200 by A / D conversion based on the sampling clock SCLK after adjusting the signal format by a decoder as necessary. The digital RGB signal is output as an image signal Din. The sampling clock SCLK is generated from a synchronization signal SYNC of the image signal Vin by a PLL (Phase Locked Loop) circuit (not shown) in the image signal processing unit 16 and supplied to the AD converter 15. This AD conversion of the image signal is performed in order to perform various image signal processes on the image signal Vin.

The image signal processing unit 16 is an image processor having a scaler function, and generates a digital image signal Dcs by performing various image processes including scaling and adjustment of gradation characteristics on the image signal Din. A frame memory 17 and an OSD memory 18 are attached to the image signal processing unit 16.
The frame memory 17 is, for example, three memory planes configured by a DRAM (Dynamic Random Access Memory) and storing image data based on image signals for red, green, and blue color lights.
The OSD memory 18 is an image memory, and stores image information such as various operation screens for operating the projector 100 and image data representing a selection cursor for selecting an image part.
The image signal processing unit 16 includes a scaler unit 19, an OSD unit 20, a gradation point adjustment unit 21, a gamma correction unit 22, a CPU unit 23, and the like.

The scaler unit 19 writes the image data of the image signal Din into the frame memory 17 for each RGB color signal at the resolution of the image signal, and converts the image data to a resolution that can be displayed by the liquid crystal light valves 5R, 5G, and 5B. By reading, a scaling process for generating an image signal that matches the resolution of the display unit is performed. In addition, trapezoidal correction processing for bringing the shape of the effective image projected on the screen closer to a rectangle is performed together with the scaling processing.
The OSD unit 20 controls an OSD (On Screen Display) function that reads an operation screen or the like from the OSD memory 18 and superimposes the read screen on an image signal. The OSD process is performed when an image for each color light of RGB is written in the frame memory 17.

The gradation point adjustment unit 21 and the gamma correction unit 22 are a one-dimensional lookup table (hereinafter referred to as “LUT”) provided in the firmware RAM area, and adjust the gradation characteristics of the image signal Din. . The “RGB-YUV conversion unit” that converts the RGB signal into the YUV signal is preceded by the gradation point adjustment unit 21, and the “YUV-RGB conversion unit that converts the YUV signal into the RGB signal is subsequent to the gamma correction unit 22. (None of them are shown), and “gradation point adjustment” and “γ correction” are performed using the Y signal of the YUV signal.
The CPU unit 23 is a CPU that controls the image signal processing unit 16 as an image processor, and controls the series of image processing using the frame memory 17 and the OSD memory 18. The configuration of the projector 100 may be configured such that the control unit 10 is omitted by the CPU unit 23 also serving as the overall control of the function of the control unit 10, for example, activation of the projector 100, image projection, and shutdown. .

The image signal correction unit 25 is a three-dimensional LUT, and the image signal Dcs input from the image signal processing unit 16 is displayed in a color reproduction region (gamut) that can be expressed by the liquid crystal light valves 5R, 5G, and 5B. A digital image signal is generated that has been subjected to color matching processing for appropriately representing an image according to, and color unevenness correction processing for correcting color unevenness specific to the liquid crystal light valves 5R, 5G, and 5B. Further, the image signal correction unit 25 has a built-in DA converter (not shown), DA-converts the digital image signal generated by the DA converter, and generates an analog image signal Vout.
The liquid crystal panel drive unit 26 supplies the liquid crystal light valves 5R, 5G, and 5B with the image signal Vout input from the image signal correction unit 25, the drive voltage, and the like, and displays the images on the liquid crystal light valves 5R, 5G, and 5B.

<Tone adjustment and correction method>
FIG. 3A is a graph showing an example of input / output characteristics in the LUT of the gradation point adjustment unit. 4A is a graph showing an example of the VT characteristic of the liquid crystal light valve, and FIG. 4B is a graph showing an example of the input / output characteristic in the LUT of the gamma correction unit.
Here, the contents of the adjustment of the gradation characteristics by the gradation point adjustment unit 21 and the gamma correction unit 22 which are characteristic portions of the present invention are shown in FIGS. 2, 3A, 4A, and 4B. Will be described.
In the projector 100, the gradation characteristics are adjusted in two stages: an adjustment by the gradation point adjustment unit 21 as the first stage and an adjustment by the gamma correction unit 22 as the second stage. Therefore, the image signal Dcs output from the image signal processing unit 16 has gradation characteristics obtained by synthesizing the adjustment contents applied in each step.

The first stage is gradation adjustment for each adjustment point of gradation characteristics by the gradation point adjustment unit 21. The gradation point adjustment unit 21 is responsible for adjustment of “custom” characteristics in “color mode” adjustment and “gamma” adjustment.
A plurality of adjustment points “gradation 1 to 9” are provided on the X axis of the graph of FIG. 3A according to the input gradation level. In addition, for each adjustment point “gradation 1 to 9”, dot display portions D1 to D9 indicating output gradation values at the respective adjustment points are provided.
Here, the LUT of the gradation point adjusting unit 21 having the input / output characteristics shown in the graph of FIG. Output. The conversion characteristics in the initial setting of the LUT are set as “y = x” where the input gradation value on the X axis is “x” and the output gradation value on the Y axis is “y”. This corresponds to a γ value of 1.0, which is “natural” in the color mode in the “color mode” adjustment. The color mode has options such as “natural”, “dynamic”, and “theater”.

“Gradation correction data” used for “color mode” adjustment and set for each color mode for giving an accent to the “reference γ characteristic” that is the base of the gradation characteristic of the image is stored in the storage unit 14 in advance. It is remembered. “Gradation correction data” is set in the LUT of the gradation point adjustment unit 21, and an output gradation value is determined for each adjustment point “gradation 1 to 9”.
In the “custom” characteristic of gamma adjustment, the output gradation value for each adjustment point “gradation 1 to 9” is adjusted to a desired value, and customized “gradation correction data” is generated.
The “custom” characteristic adjustment is performed by the gradation point adjustment unit 21, but the adjustment operation is performed from the “gamma” adjustment operation screen, not from the operation screen on which the color mode selection operation is performed.

  The second stage is adjustment for correcting the gradation characteristics inherent to the liquid crystal light valves 5R, 5G, and 5B by the gamma correction unit 22. In the following description, the adjustment of the gradation characteristics by the gradation point adjustment unit 21 is “gradation point adjustment”, and the adjustment for correcting the gradation characteristics specific to each liquid crystal light valve by the gamma correction unit 22. This will be described as “γ correction”.

In the graph of FIG. 4A, the horizontal axis represents the voltage applied to the liquid crystal light valve in 8 bits, and the vertical axis represents the light transmittance. As shown in FIG. 4A, each of the liquid crystal light valves 5R, 5G, and 5B has a unique gradation characteristic (also referred to as “voltage versus transmittance characteristic” or “VT characteristic”).
The gamma correction unit 22 performs correction using the LUT so that the gradation characteristics unique to the liquid crystal light valves 5R, 5G, and 5B become the input / output characteristics indicated by the reference γ characteristics in the graph of FIG. For this reason, the LUT provided for each of the liquid crystal light valves 5R, 5G, and 5B of the gamma correction unit 22 has gradation characteristics specific to the liquid crystal light valves 5R, 5G, and 5B as shown in FIG. “Γ correction data” having input / output characteristics for conversion to a reference γ characteristic (for example, γ value 2.2) is set.
The projector 100 has five options of γ values of 2.0 to 2.4 (0.1 increments) as reference γ characteristics. The γ correction data corresponding to these reference γ characteristics is set in advance after measuring the gradation characteristics for each of the liquid crystal light valves 5R, 5G, and 5B in the manufacturing stage of the projector 100, and is stored in the storage unit 14. ing.

As described above, the gradation characteristics of the projector 100 are adjusted in two ways: “gradation point adjustment” by the gradation point adjustment unit 21 as the first step and “γ correction” by the gamma correction unit 22 as the second step. Since the processing is performed in stages, the image signal Dcs output from the image signal processing unit 16 has gradation characteristics obtained by synthesizing the adjustment contents applied in the respective stages. This can be described by a graph, which is expressed as a gradation characteristic obtained by combining the reference γ characteristic obtained by “γ correction” in FIG. 4A and the adjustment characteristic obtained by “gradation point adjustment” in FIG.
Note that the gradation characteristics may be adjusted in the order in which the adjustment by the gamma correction unit 22 is performed first and then the adjustment by the gradation point adjustment unit 21 is performed.
Thus, for example, by various combinations such as “natural” or “dynamic” or “theater” mode in the reference γ characteristic “γ value 2.0”, and various color modes in the reference γ characteristic “γ value 2.3”. Various tone characteristics are generated.

FIG. 3B is a table showing the gradation amount per step for each adjustment point in the graph of FIG. Here, with reference to FIG. 3B, the “gradation point adjustment” by the gradation point adjustment unit 21 in the first stage will be described in more detail.
In the graph of FIG. 3B, there are nine adjustment points (gradations 1 to 9), and up to six points are set to 511 gradation values or less which are intermediate gradation values.
Of the remaining three points, one point (gradation 7) is provided at the 512 gradation value, which is a substantially intermediate gradation value, so about 78% of adjustment points are from low to medium in the input gradation. It is provided in the gradation range. This is because more adjustment points are provided in a gradation range having a high adjustment frequency determined from an empirical rule.

In order to select the adjustment point from these multiple adjustment points and adjust the gradation characteristics, select the “Custom” characteristic from the “Gamma” adjustment options and select “Cursor adjustment mode” or In “Graph Adjustment Mode”, specify the image part or adjustment point you want to adjust.
For example, when the lower left image part of the image projected on the screen SC of FIG. 1 is selected and determined by the selection cursor 51 in the “cursor adjustment mode”, the closest to the gradation value of the selected image part is shown in FIG. An adjustment point (for example, gradation 4) in the graph of a) is selected.

The adjustment of the output gradation at the selected adjustment point is performed by “up / down buttons” or “left / right buttons” as plus and minus buttons of the operation unit 1 or the remote controller 2. For example, the functions as the plus and minus buttons are “left / right buttons” on the gradation adjustment screen G4 in FIG. 9B, and “up / down buttons” on the graph adjustment screen G12 in FIG. Take on.
The predetermined gradation amount per step by one increase and decrease operation at each adjustment point is, for example, when the plus button is operated once at the adjustment point “gradation 4”, the output gradation value is Then, “4 counts” is increased by one step as a predetermined gradation amount. Similarly, when the minus button is operated once, the output gradation value decreases by “4 counts” by one step. Further, when the plus and minus buttons are kept pressed (hereinafter referred to as “long press”), the number is continuously increased or decreased by one step amount according to the long press time.

As described above, the adjustment gradation amount as a predetermined gradation amount per step by one increase and decrease operation at each adjustment point is determined in advance.
As shown in FIG. 3B, the gradation amount for each adjustment point is “2 counts” for one step at the adjustment point “gradation 8 and 9” in the high gradation region, and other low to medium gradations. In the adjustment point of the area, “4 counts” for one step is set so that the adjustment amount at the adjustment point of the low to medium gradation area is larger than that in the high gradation area.
This is determined from an empirical rule that the amount of adjustment of the gradation value in the high gradation region is smaller than that in the low to medium gradation region.

<Details of selection cursor>
FIG. 5A is an enlarged view of the selection cursor in one embodiment. FIG. 5B is a diagram illustrating an aspect of a selection state of an image part by the selection cursor.
Here, details of the selection cursor used in the “cursor adjustment mode” will be described. FIG. 5A is an enlarged view of the selection cursor 51 for selecting the background image portion of the lower left person in the projected image of the screen SC in FIG.

The selection cursor 51 includes a pixel selection unit 52 and an annular part 53.
The pixel selection unit 52 indicates a selection range for selecting a desired image portion in the image, and selects pixels that fall within the selection range from the effective display pixels of the liquid crystal light valve that is the display unit. In the case of the pixel selection unit 52, nine pixels of pixels p1 to p9 consisting of three consecutive vertical and horizontal pixels are the selection range. Note that the number of pixels is not limited to nine pixels, and may be any number of continuous pixels of three or more pixels.
The annular portion 53 is provided so as to wrap around the pixel selection portion 52 and is always set to have the same color tone as the pixel selection portion 52. The annular portion 53 always moves together with the pixel selection portion 52, and the positional relationship between them is always kept constant.
Since the annular portion 53 surrounds the pixel selection portion 52 in this manner, the selection cursor 51 is located at a small position in the image of the screen SC in FIG. Has also been clearly confirmed.

The selection cursor 51 is superimposed by the OSD unit 20 when the image data for each RGB signal is written in the frame memory 17 in the scaling process by the scaler unit 19. The position of the selection cursor 51 is grasped by the CPU 23 from the initial address at the address on the frame memory 17 by the amount of movement by the operation of the “up / down button” and “left / right button”. Incidentally, the position of the selection cursor 51 in the initial setting is substantially the center of the image.
The gradation value of the pixel selected by the selection cursor 51 is calculated as the luminance signal data (Y signal data) by calculating the image data of the selected pixel in the frame memory 17 in which the image data for each RGB signal is written. As required. Specifically, the luminance signal data is obtained by a calculation such as “Y = 0.299R + 0.587G + 0.144B”.
The projector 100 obtains the average value of the gradation values excluding the maximum and minimum gradation values from the gradation values (Y signal) of the nine pixels thus obtained, as the gradation value of the selected image portion. Recognize as This is to exclude extraneous pixel components due to noise or the like in the image. Note that an average of gradation values of all the selected pixels may be recognized as the gradation value of the selected image portion.

FIG. 5B shows an aspect of the selection cursor when the edge of the image V is selected by the selection cursor. Note that, when the position of the selection cursor 51 reaches the edge of the image V, the CPU unit 23 performs control so that the entire picture of the pixel selection unit 52 does not protrude from the image V. The image V is a bright image with gradation values close to all white.
The selection cursors 51i and 51j select the image part around the lower left of the image V. Here, for the sake of explanation, the selection cursors 51i and 51j are shown side by side on the same screen, but only one of them is actually displayed.
The pixel selection unit 52 of the selection cursor 51i has selected the nine pixels at the extreme end in the lower left of the image V. In this case, the annular portion 53 is displayed only in a portion within the range of the image V.
Similarly, in the case of the selection cursor 51j that selects the pixel on the lower left side of the image V, the annular portion 53 is displayed only in a portion within the range of the image V.
Thus, even when the edge of the image V is selected with the selection cursor, the shape of the annular portion 53 within the range of the image V is displayed, so that the selection cursor is clearly confirmed.

Further, the selection cursors 51i and 51j displayed on the bright image V close to all white have a tone of all black. On the other hand, the selection cursor 51 is white in the image of the screen SC of FIG.
As described above, the CPU section 23 adjusts the color tone of the selection cursor so that the color tone of the selected image part and white or black has the larger contrast according to the gradation of the selected image part. It is controlled by.

<< First Image Adjustment Process Flow-1: To Branch Screen >>
FIG. 6 is a flowchart showing the flow of image adjustment up to the branch screen. FIG. 7A is a diagram illustrating an aspect of the selection screen, and FIG. 7B is a diagram illustrating an aspect of the branch screen.
Here, the flow of processing up to the branch screen in the first mode of image adjustment by the projector 100 will be described with reference to FIGS. 7A, 7B, and 2 as appropriate, centering on FIG.
The projector 100 is installed in an environment as shown in FIG. 1 and is operated by the remote controller 2.

In step S <b> 1, the control unit 10 confirms whether or not there is an operation for performing “gamma” adjustment based on the operation signal from the operation receiving unit 11. If there is an operation to perform “gamma” adjustment, the process proceeds to step S2. If there is no operation, it continues to wait for the operation. By this operation, the “gradation adjustment program” in the storage unit 14 is activated, and the following processing is performed according to the order and contents of the gradation adjustment defined in the program.
In step S2, the control unit 10 causes the image signal processing unit 16 to superimpose the selection screen G1 shown in FIG.

On the left side of the selection screen G1, γ values of 2.0 to 2.4, “custom” indicating custom characteristics, and reset options are displayed as gradation characteristic options. The screen on the right side of the selection screen G1 shows the gradation characteristics of the selected option. The selection screen G1 shows a state in which “custom” is selected, and the graph on the right side of the screen shows the gradation characteristics.
The graph of the selection screen G1 shows a gradation characteristic obtained by synthesizing “γ correction” and an adjustment characteristic by “gradation point adjustment”. This straight line shows a reference γ characteristic “γ value 2.2”. I mean. Since the reference γ characteristic in the initial setting of the projector 100 is “γ value 2.2”, the scale axis is set as a straight line when the graph is “γ value 2.2”. This is because the default basic γ characteristic in the custom characteristic is also set to “γ value 2.2”.
Note that the scale axes are also set in the graphs on various operation screens used in the following description.

In addition, under the selection screen G1, the names of operation buttons corresponding to the operation unit 1 or the remote controller 2 for operating the selection screen G1 are shown. Specifically, the “Esc button” is used to return the operation step by one step, the “Up / Down button” is used to select the gradation characteristic, the “Select button” is used to determine the selection of the “Custom” characteristic, It is displayed when you use the “Menu button” to end the adjustment. It should be noted that such operation guidance displays on other operation screens described below have the same meaning.
In the following description, when a new operation screen is displayed, the operation screen that has been displayed is closed, and after the operation screen is displayed, no operation is performed for a certain time, for example, 2 minutes. If the operation is not performed, the operation screen is closed and the adjustment is finished.

In step S <b> 3, the control unit 10 confirms whether there has been an operation for selecting any of the characteristics from the gradation characteristic options on the selection screen G <b> 1 by an operation signal from the operation receiving unit 11. If there is a selection operation, the process proceeds to step S4. If there is no selection operation, it continues to wait for the operation.
In step S4, the control unit 10 sets the γ correction data of the selected gradation characteristic in the LUT of the gamma correction unit 22, and projects an image based on the gradation characteristic. At this stage, the projected image on the back of the selection screen G1 is an image that has been adjusted according to the selected gradation characteristics.
In step S <b> 5, the control unit 10 confirms whether or not there is an operation for determining the gradation characteristic selected by the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S6. If there is no determination operation, the process returns to step S3, and the selection operation is accepted until the determination operation is performed.

In step S <b> 6, the control unit 10 confirms whether the selected gradation characteristic is a “custom” characteristic. If it is “custom” characteristics, the process proceeds to step S7. If it is not the “custom” characteristic, the process proceeds to step S10.
In step S7, the control unit 10 causes the image signal processing unit 16 to superimpose the branch screen G2 shown in FIG. 7B on the image signal.
The branch screen G2 displays an option for selecting one of “cursor adjustment mode” expressed as “adjust from video” and “graph adjustment mode” expressed as “adjust from graph”. Has been. The branch screen G2 represents a state where the “cursor adjustment mode” is selected.

In step S <b> 8, the control unit 10 confirms whether or not there is an operation for selecting and determining the “cursor adjustment mode” based on the operation signal from the operation receiving unit 11. If there is a selection decision operation, the process proceeds to the “cursor adjustment mode” subroutine. When there is no selection decision operation, it progresses to step S9.
In step S <b> 9, the control unit 10 confirms whether or not there is an operation for selecting and determining the “graph adjustment mode” based on the operation signal from the operation receiving unit 11. If there is a selection decision operation, the process proceeds to the “graph adjustment mode” subroutine. If there is no selection decision operation, the process returns to step S7 and waits for a selection and decision operation.
Subsequently, a case where the “custom” characteristic is not obtained in step S6 will be described.
In step S10, the control unit 10 closes the selection screen G1 by the image signal processing unit 16 in a state where the γ correction data of the gradation characteristics selected and determined is set in the LUT of the gamma correction unit 22, and “gamma” Finish the adjustment.

Note that the selection record in which the “cursor adjustment mode” or the “graph adjustment mode” has been selected and stored is stored in the storage unit 14, and in the next operation, the selection record adjustment mode is selected in the step S 7. A branch screen is displayed.
Further, when the selected gradation characteristic is “custom” characteristic in step S6, it is not limited to displaying the branch screen G2, but for example, adjusting either the direct graph or the cursor adjustment mode. A processing routine for entering the mode may be used.

<< First Image Adjustment Process Flow-2: Cursor Adjustment Mode >>
FIG. 8 is a flowchart showing the flow of image adjustment in the cursor adjustment mode. FIG. 9A is a diagram illustrating an aspect of the characteristic confirmation screen, and FIG. 9B is a diagram illustrating an aspect of the gradation adjustment screen. FIG. 10A is a diagram illustrating an aspect of the characteristic confirmation screen, and FIG. 10B is a diagram illustrating an aspect of the continuation confirmation screen.
Here, the flow of image adjustment in the cursor adjustment mode of the projector 100 will be described with reference to FIGS. 9A, 9B, 10A, 10B, and FIG. .

In step S <b> 21, the control unit 10 causes the image signal processing unit 16 to freeze the image. This is because it is difficult to select an image part if it is a moving image.
In step S <b> 22, the control unit 10 causes the image signal processing unit 16 to superimpose the “selected cursor” on the image signal. This state is, for example, like the selection cursor 51 on the image on the screen SC of FIG.
In step S <b> 23, the control unit 10 confirms whether or not there has been an operation for determining the image portion selected by the “selection cursor” based on the operation signal from the operation receiving unit 11. If there is a selection decision operation, the process proceeds to step S24. If there is no selection decision operation, the selection decision operation is awaited.

In step S24, the control unit 10 causes the image signal processing unit 16 to blink the selected image portion and superimpose the characteristic confirmation screen G3 of FIG. 9A on the image signal.
In this process, first, the control unit 10 reads out image data for each color of RGB at the image portion selected by the “selection cursor” from the frame memory 17, and luminance signal data (Y signal data) from the image data of each pixel. Ask for. Next, an average value of the Y signal data excluding the maximum and minimum gradation values of the Y signal data of each pixel is obtained. Then, the adjustment point closest to the obtained Y signal data is selected as the adjustment point to be adjusted.
Further, the blinking of the selected image portion is obtained by adding the output gradation value of the selected adjustment point in the “gradation correction data” of the gradation point adjustment unit 21 (LUT) to the initial output gradation value plus 32 counts. This is done by switching every 1 Hz with a minus 32 count.
The characteristic confirmation screen G3 shows a state where the adjustment point “gradation 2” is selected, and the display dot portion D2 of the adjustment point “gradation 2” blinks in synchronization with the blinking cycle of the image portion. is doing. Note that the display method of the display dot portion is not limited to blinking. For example, the color tone of the display dot portion may be changed to a color tone different from that of other display dot portions, such as orange. good.

In step S <b> 25, the control unit 10 confirms whether or not there has been an operation for determining the selected adjustment point based on the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S26. If there is no decision operation, it waits for the decision operation.
In step S26, the control unit 10 causes the image signal processing unit 16 to stop blinking of the image portion and superimpose the gradation adjustment screen G4 of FIG. 9B on the image signal. In step S24, a processing routine for displaying the gradation adjustment screen G4 instead of the characteristic confirmation screen G3 may be used. In the case of this flow, the confirmation of the selection determination operation in step S25 is not necessary, and the blinking of the image part is stopped using the adjustment operation on the gradation adjustment screen G4 as a trigger.
In step S <b> 27, the control unit 10 confirms whether there is an operation for adjusting the output gradation value based on the operation signal from the operation receiving unit 11. If there is an adjustment operation, the process proceeds to step S28. If there is no adjustment operation, it waits for the adjustment operation.
In step S28, the control unit 10 sequentially sets the adjusted “gradation correction data” in the LUT of the gradation point adjustment unit 21, and projects an image based on the gradation characteristics. At this stage, the projected image on the back side of the gradation adjustment screen G4 is an image that has been image-adjusted in real time with gradation characteristics according to the adjustment content.

In step S <b> 29, the control unit 10 confirms whether or not there has been an operation for determining the adjustment content based on the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S30. If there is no determination operation, the process returns to step S27, and the adjustment operation is accepted until the determination operation is performed.
In step S30, the control unit 10 causes the image signal processing unit 16 to superimpose the characteristic confirmation screen G5 of FIG. In the characteristic confirmation screen G5, a graph showing the gradation characteristics after the gradation point adjustment is displayed.
In step S <b> 31, the control unit 10 confirms whether or not there is an operation for confirming the adjustment result based on the operation signal from the operation receiving unit 11. If there is a confirmation operation, the process proceeds to step S32. If there is no confirmation operation, it waits for the confirmation operation. Further, when there is a confirmation operation, the contents adjusted so far are stored in the storage unit 14 as “tone correction data” having “custom” characteristics. An operation screen for assigning a name to the adjusted “custom” characteristic is displayed. For example, there is a processing routine for storing characteristic names such as “custom 1” and “custom B”. Also good.

In step S32, the control unit 10 causes the image signal processing unit 16 to superimpose the continuation confirmation screen G6 of FIG. 10B on the image signal. The continuation confirmation screen G6 displays a confirmation display for confirming whether or not to continue the adjustment in the cursor adjustment mode.
In step S <b> 33, the control unit 10 confirms whether there has been an operation for continuing the adjustment based on the operation signal from the operation receiving unit 11. If there is a continuation operation, the process returns to step S22, and the adjustment in the cursor adjustment mode is continued using the “tone correction data” adjusted so far as the base data. If there is no continuation operation, the continuation confirmation screen G6 is closed and the adjustment in the cursor adjustment mode is ended.

FIG. 11 is a diagram illustrating an aspect when the operation screen is superimposed on the image. Here, the display positions of the characteristic confirmation screen and the gradation adjustment screen will be described.
In step S24, the characteristic confirmation screen G3 in FIG. 9A is superimposed on the image signal using the selection position determination operation as a trigger. The display position of the characteristic confirmation screen G3 at this time is as shown in FIG. A characteristic confirmation screen G3 is displayed at the lower right. This is because the image signal processing unit 16 controls the image portion selected by the selection cursor 51 and the characteristic confirmation screen G3 so as not to overlap as much as possible. In FIG. 11, for the sake of explanation, the selection cursor 51 and the characteristic confirmation screen G3 are displayed on the same screen, but as described above, both are not actually displayed together.
In addition, the initial display position of the operation screen such as the selection screen, branch screen, characteristic selection screen, and gradation adjustment screen is set at the lower left part of the image, but the display position of the characteristic confirmation screen and gradation adjustment screen Is controlled so as not to overlap the selected image portion or the image portion corresponding to the selected adjustment point. Further, the size of these operation screens is set to ¼ or less of the image area as in the characteristic confirmation screen G3.

In addition, the background in which the blinking of the selected image part in step S24 is performed by increasing / decreasing ± 32 counts of the output gradation value and the reason why the blinking cycle is set to 1 Hz will be described.
The output gradation level in a general image display apparatus is 8 to 10 bits, which is 256 to 1024 output gradation values. Here, when the screen part is visually recognized by the blinking of the screen part, if the gradation is gradually increased or decreased from the gradation “zero” to the maximum value by the full scale of the output gradation level, the contrast is too large and the image is displayed. It flickers and the observer's eyes become tired. In addition, the responsiveness of the display unit may not catch up, and an image with an afterimage may appear. In order to prevent such a phenomenon, it is preferable to perform blinking of the selected image portion with a gradation amount of ± 10% or less in the full scale of the output gradation value.
Therefore, although the increase / decrease amount of the output gradation value is set to ± 32 counts, the present invention is not limited to this, and any gradation amount that is ± 10% or less in the full scale of the output gradation value may be used.
In addition, it is said that the flickering period is set to 1 Hz. Generally, when the flickering period exceeds 3 Hz, human visual characteristics gradually increase the degree of feeling of discomfort due to image flickering. Because. Therefore, the blinking cycle is not limited to 1 Hz, and may be within a range of 0.5 to 3 Hz.

<< First Image Adjustment Process Flow-3: Graph Adjustment Mode >>
FIG. 12 is a flowchart showing a flow of image adjustment in the graph adjustment mode. 13A and 13C are diagrams illustrating an aspect of the characteristic confirmation screen, and FIG. 13B is a diagram illustrating an aspect of the gradation adjustment screen.
Here, the flow of image adjustment in the graph adjustment mode of the projector 100 will be described with reference to FIGS. 13A, 13 </ b> B, 13 </ b> C, and FIGS.

In step S41, the control unit 10 causes the image signal processing unit 16 to freeze the image.
In step S42, the control unit 10 causes the image signal processing unit 16 to superimpose the characteristic confirmation screen G7 of FIG. 13A on the image signal. The characteristic confirmation screen G7 is displayed in a state where the adjustment point “gradation 1” is selected, and the image portion corresponding to the adjustment point “gradation 1” blinks at a cycle of 1 Hz. Further, the dot display portion D1 of the adjustment point “gradation 1” also blinks in synchronization.
In addition, the display method of a dot display part may be changing the color tone of a display dot part into a different color tone from the color tone of other display dot parts, such as orange.

In step S <b> 43, the control unit 10 confirms whether an operation for selecting an adjustment point has been performed based on an operation signal from the operation receiving unit 11. If there is a selection operation, the process proceeds to step S44. If there is no selection operation, the selection operation is awaited.
In step S44, the control unit 10 causes the image signal processing unit 16 to blink the image portion corresponding to the selected adjustment point in a 1 Hz cycle. Further, the dot display portion of the selected adjustment point on the characteristic confirmation screen G7 is also blinked in synchronization. It should be noted that the blinking of the image portion is determined by setting the output gradation value of the adjustment point selected in the “gradation correction data” of the gradation point adjustment unit 21 (LUT) to the initial output gradation value plus 32 counts and minus 32 counts. Then, it is performed by switching every 1 Hz period.

In step S <b> 45, the control unit 10 confirms whether there is an operation for determining the selected adjustment point based on the operation signal from the operation reception unit 11. If there is a determination operation, the process proceeds to step S46. If there is no determination operation, the process returns to step S43, and the selection operation is accepted until there is a determination operation.
In step S46, the control unit 10 causes the image signal processing unit 16 to stop the blinking of the image portion and to superimpose the gradation adjustment screen G8 in FIG. 13B on the image signal. In step S44, the characteristic confirmation screen G7 may be closed and the gradation adjustment screen G8 may be displayed. In the case of this flow, the confirmation of the selection decision operation in step S45 is not necessary, and the blinking of the image part is stopped using the adjustment operation on the gradation adjustment screen G8 as a trigger.
In step S <b> 47, the control unit 10 confirms whether there is an operation for adjusting the output gradation value based on the operation signal from the operation receiving unit 11. If there is an adjustment operation, the process proceeds to step S48. If there is no adjustment operation, it waits for the adjustment operation.
In step S48, the control unit 10 sequentially sets the adjusted “gradation correction data” in the LUT of the gradation point adjustment unit 21, and projects an image based on the gradation characteristics. At this stage, the projected image on the back of the gradation adjustment screen G8 is an image that has been image-adjusted in real time with gradation characteristics corresponding to the adjustment content.

In step S <b> 49, the control unit 10 confirms whether or not there has been an operation for determining the adjustment content based on the operation signal from the operation receiving unit 11. If there is a decision operation, the process returns to step S42. If there is no determination operation, the process returns to step S47, and the adjustment operation is accepted until the determination operation is performed.
If there is a determination operation, the operation screen displayed in step S42 is a characteristic confirmation screen G9 as shown in FIG. In the characteristic confirmation screen G9, for example, the output gradation value of the adjustment point “gradation 5” is a gradation value that incorporates the content of the adjustment performed previously. This adjustment content is already stored in the storage unit 14 as “tone correction data” having “custom” characteristics. An operation screen for assigning a name to the adjusted “custom” characteristic is displayed. For example, there is a processing routine for storing characteristic names such as “custom 1” and “custom B”. Also good.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Since the storage unit 14 stores a plurality of gradation characteristic data including custom characteristics that can customize the characteristics used for image adjustment, the projector 100 has many choices of gradation characteristics and is used. It is possible to respond to choices depending on the diverse preferences of the person.
When an operation for selecting the gradation characteristic of the selection screen G1 is performed, the image signal processing unit 16 adjusts the gradation characteristic of the image signal according to the selected gradation characteristic, and an image based on the adjusted image signal is displayed. Since the projection is performed, it is possible to confirm an image including the adjustment content in the background of the selection screen G1 in the adjustment content selection stage.
Therefore, the projector 100 can perform image quality adjustment according to the user's preference, and can confirm an image incorporating the adjustment content at the adjustment content selection stage.

(2) Since the selection screen G1 includes a graph representing the correlation between the input of the selected gradation characteristic and the output gradation level, the graph representing the selected gradation characteristic is visually recognized. be able to.
Therefore, the projector 100 can also confirm a graph representing the gradation characteristics of the image in addition to the image incorporating the adjustment content at the adjustment content selection stage.

(3) Since the OSD unit 20 superimposes the branch screen G2 for selecting either the graph or the cursor adjustment mode on the image signal with the selection of the custom characteristic as a trigger, the branch screen G2 Either the graph or the cursor adjustment mode can be selected.
Therefore, the projector 100 can select an adjustment method according to the user's preference.

(4) A selection record that is a record in which the “cursor adjustment mode” or the “graph adjustment mode” is selected and determined is stored in the storage unit 14, and a branch screen in which the adjustment mode of the selected record is selected at the next operation. Since G2 is displayed, the possibility that the user selects and operates the adjustment mode is reduced.
Therefore, the projector 100 is easy to use.

(5) When a custom characteristic is selected, a characteristic that is a smaller graph than an image showing the default gradation characteristic of the custom characteristic, regardless of which adjustment mode is “cursor adjustment mode” or “graph adjustment mode” Since the confirmation screen is displayed, the default gradation characteristic of the custom characteristic can be confirmed on the characteristic confirmation screen.
Further, in the “graph adjustment mode”, when an operation for selecting any one of a plurality of dot display portions indicating the output gradation level for each adjustment point in the graph of the characteristic confirmation screen G7 is performed, the OSD portion 20 Since the superimposition of the characteristic confirmation screen G7 is stopped and the gradation adjustment screen G8 smaller than the still image for adjusting the output gradation level of the selected adjustment point is superimposed on the image signal, the gradation adjustment screen G8 Thus, the output gradation level of the selected adjustment point can be adjusted.
Therefore, the projector 100 can adjust the image quality according to the user's preference after confirming the gradation characteristics with the graph.

(6) When the “cursor adjustment mode” is selected and determined, the selection cursor 51 is displayed and the image is stationary. Therefore, it is difficult to select the image part by the selection cursor 51, which is difficult when the image is moving. It can be done easily on the image.
Further, when an operation for selecting an image part with the selection cursor 51 is performed, the OSD unit 20 performs an operation for determining the selected image part and then outputs an output gradation level at an adjustment point of gradation characteristics corresponding to the selected image part. Since the gradation adjustment screen G4 smaller than the still image for adjusting the image is superimposed on the image signal, the output gradation level of the selected adjustment point can be adjusted by the gradation adjustment screen G4.
Therefore, the projector 100 can easily select a desired image portion, and can perform image quality adjustment according to the user's preference.

(7) The image signal processing unit 16 adjusts the gradation value of the image portion corresponding to the adjustment point in the still image to the output gradation level on which the adjustment operation is performed in accordance with the gradation level adjustment operation on the gradation adjustment screen. Since the adjustment is performed sequentially according to the adjustment, an image including the adjustment content can be confirmed in real time during the adjustment.
Therefore, the projector 100 can adjust the image quality according to the user's preference, and can check the image including the adjustment contents in real time when the adjustment is performed.

(8) Since a plurality of adjustment points in the custom characteristics are distributed in a range from the low gradation range to the middle gradation range on the input side, the projector 100 allows the user to adjust the gradation most. There are many adjustment points in the gradation area necessary for the "image quality creation" that is expected.
In addition, since the predetermined output gradation amount for each adjustment point is set so that the adjustment point in the low gradation area is larger than the adjustment point in the high gradation area, the graph adjustment screen, The adjustment amount per step of the gradation adjustment screen is set to an adjustment amount that meets the usage needs.
Therefore, the projector 100 is easy to use and can perform image adjustment according to the user's preference.

(9) Since the size of the operation screen including the selection screen, the characteristic confirmation screen, the gradation adjustment screen, and the branch screen is 1/4 or less of the image, even if the portion hidden by the operation screen is excluded, A total of 3/4 or more images can be confirmed. Furthermore, as the initial setting, the operation screen is arranged inside any one of the four corners of the substantially rectangular image, so that the central portion that is the center of the image is not hidden by the operation screen.
Further, since the OSD unit moves the position of the operation screen within the range of the image so that the selected image portion and the operation screen do not overlap with each other, the adjustment of the selected image portion that is most worrisome at the time of adjustment is performed. The situation can be checked during adjustment.
Therefore, the projector 100 can perform image adjustment while always checking the state of the image.

(10) The default gradation characteristics in the default custom characteristics are provided to be changeable, and any one of the plurality of gradation characteristics stored in the storage unit 14 is set. Therefore, it is possible to select a gradation characteristic as a base according to the user's preference.
The adjusted custom characteristics are stored in the storage unit, and the next time the selection screen is displayed, the adjusted custom characteristics are displayed as one of a plurality of gradation characteristic options. Can be easily reproduced.
Therefore, the projector 100 is easy to use and can perform image adjustment according to the user's preference.

(11) In the “cursor adjustment mode”, when an image adjustment operation is performed, the image signal processing unit 16 stops the image and displays a selection cursor 51 for selecting a desired image part on the image. Display on the screen. Therefore, if the image is a moving image, it is difficult to select an image part because the image changes, but it is easy to select by making the image still. Further, a desired image part can be selected from the still images by the selection cursor 51.
When an operation for selecting an image part with the selection cursor 51 is performed, the OSD unit 20 displays an image of a characteristic confirmation screen in which the adjustment point corresponding to the gradation of the selected image part blinks or the color tone of the adjustment point is changed. Since the image is superimposed on the signal, the position of the image portion in the gradation characteristics of the entire image is clearly shown on the graph. Therefore, the adjustment point in the gradation characteristics of the entire image can be confirmed on the graph before the gradation adjustment.
Further, when an operation for determining the selected image part is performed, the OSD unit 20 superimposes the gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image part on the image signal. The gradation adjustment of the selected image part can be performed on the screen.
Therefore, the projector 100 can select a desired adjustment part from the projected image, and can adjust the image of the selected adjustment part after confirming the gradation characteristics of the entire image.

(12) The image signal processing unit 16 selects one of a plurality of reference γ characteristics determined in advance in order to make the gradation characteristics unique to the liquid crystal light valves 5R, 5G, and 5B suitable for human visual characteristics. A gamma correction unit 22 for correcting to one reference γ characteristic, a gradation point adjustment unit 21 for adjusting an output gradation value for each of a plurality of adjustment points provided according to an input level in the reference γ characteristic, Therefore, each function is performed by an independent dedicated component. Therefore, since each structure can be dedicated, it can be set as a simple structure.
Further, the gradation adjustment to the image signal as the image signal processing unit 16 is performed by gradation characteristics obtained by combining the γ correction in the gamma correction unit 22 and the gradation point adjustment in the gradation point correction unit 21. Advanced gradation adjustment can be performed by the two adjustment portions.
In addition, when the output gradation value is adjusted on the gradation adjustment screen of the selected adjustment point, the gradation point adjustment unit changes the output gradation value of the adjustment point according to the adjustment content. The image on the back of the gradation adjustment screen is updated to an image reflecting the adjustment contents in real time.
Therefore, according to the projector 100, advanced gradation adjustment is possible with a simple gradation adjustment configuration, and an image reflecting the adjustment content can be confirmed in real time.

(13) In the “cursor adjustment mode”, the selection cursor 51 includes a pixel selection unit 52 having a size for selecting a plurality of consecutive pixels of three or more pixels in the liquid crystal light valve pixel. Based on the pixel data of a plurality of pixels having a width, it is possible to determine a selection portion intended by the user.
Further, the adjustment point of the gradation characteristic corresponding to the selected image part is the average value of the gradation values for each of the plurality of pixels selected by the pixel selection unit, or for each of the plurality of pixels selected by the pixel selection unit. Since the adjustment point of the input gradation level that is closest to the average value excluding the maximum and minimum gradation values in the gradation value is selected, the influence of the pixel data including noise is reduced, and the user intends It is possible to select an adjustment point corresponding to the selected image part.
Therefore, the projector 100 can accurately select the adjustment site intended by the user from the projected image.

(14) In the “cursor adjustment mode”, the pixel selection unit 52 preferably has a size for selecting a total of nine pixels in a rectangular shape composed of three pixels in the vertical and horizontal directions. Even when the average value is taken except for, effective pixel data of 7 pixels is obtained. Moreover, since it becomes a moderate size in the whole image, it is easy to visually recognize it, and since it is a square shape, it is easy to select an image part.
Therefore, the projector 100 can easily and accurately select the adjustment site intended by the user from the projected image.

(15) In the “cursor adjustment mode”, the selection cursor 51 further includes an annular portion 53 including a shape obtained by enlarging a part of the outer shape of the pixel selection portion 52 on the outer periphery of the pixel selection portion 52. 53 always maintains a relative position with respect to the pixel selection unit 52 and moves on the still image together with the pixel selection unit 52. Therefore, the selection cursor 51 has a circular portion 53 that is slightly larger than the pixel selection unit 52. And is displayed larger and clearer on the image.
Furthermore, the image signal processing unit 16 adjusts the color tone of the selection cursor 51 to the color tone having the higher contrast between the color tone of the image portion selected by the selection cursor 51 and the color tone of white or black. The color tone of the selection cursor 51 is a color tone that is easy to visually recognize.
Therefore, it is easy to select a desired image portion with the selection cursor 51 displayed clearly.
Therefore, according to the projector 100, a desired image part can be easily selected by a selection cursor that is clearly displayed on the image.

(16) In the “cursor adjustment mode”, the position of the pixel selection unit 52 is set by the image signal processing unit 16 so that the entire picture of the pixel selection unit 52 does not protrude from the still image in the selection operation of the image part by the selection cursor 51. When the pixel selection unit 52 is controlled to reach the edge of the still image, the selection cursor 51 is displayed in a state where a part of the image of the annular portion 53 protruding from the still image is missing. The image up to the image part of the edge of the image can be selected, and the selection cursor 51 can be visually recognized even when the edge of the image is selected.
Therefore, the projector 100 can select a desired image portion in all the effective image areas with the selection cursor.

(17) In the “cursor adjustment mode”, when an image adjustment operation is performed, the image signal processing unit 16 stops the image and displays a selection cursor 51 for selecting a desired image portion on the image. Display on the screen. Therefore, if the image is a moving image, it is difficult to select an image part because the image changes, but it is easy to select by making the image still. Further, a desired image part can be selected from the still images by the selection cursor 51.
Further, when an image part is selected from among the still images by the selection cursor 51, the image signal processing unit 16 selects the selected image part in the still image and an image part having substantially the same gradation as the selected image part. Therefore, the selected image portion including substantially the same gradation portion is displayed separately from other image portions by blinking. Therefore, the selected image part can be clearly visually recognized. In addition, this makes it possible to identify at a glance even when an unexpected part is selected.
Therefore, the projector 100 can select a desired image adjustment part from the display image, and can clearly recognize the selected image part.

(18) In the “cursor adjustment mode”, the blinking of the image portion selected by the selection cursor 51 and the image portion having substantially the same gradation as the image portion is input in the gradation characteristics of the image signal representing the still image. This is done by periodically increasing or decreasing the output gradation value at the adjustment point of the input gradation level that is closest to the gradation value of the selected image portion among the plurality of adjustment points corresponding to the gradation level. Thus, the selected image portion and substantially the same gradation portion can be blinked by a simple method of increasing or decreasing the output gradation value at one adjustment point.
Therefore, according to the projector 100, the selected image part and the image part selected together can be visually recognized and identified by a simple method.

(19) The image signal processing unit 16 selects any one of the basic gradation characteristics from among a plurality of basic gradation characteristics determined in advance in order to make the gradation characteristics unique to the display section suitable for human visual characteristics. A gamma correction unit 22 for correcting tonal characteristics, and a gradation point adjusting unit 21 for adjusting an output gradation value for each of a plurality of adjustment points provided according to the input level in the basic gradation characteristics, Since each is a one-dimensional LUT, each has a simple configuration with a dedicated function. Therefore, the correction data set in each LUT can also have a simple data configuration, not complex large-capacity data.
Further, the blinking of the image portion selected by the selection cursor 51 and the image portion having substantially the same gradation as the image portion is performed by the gradation point adjustment unit 21, and thus affects the basic gradation characteristics. And the image portion can be blinked.
Therefore, the projector 100 can visually recognize and identify the selected image part and the image part selected together with a simple configuration.

(20) Increase / decrease in output gradation value for blinking the image point at the adjustment point corresponding to the image portion selected by the selection cursor 51 in the “cursor adjustment mode” or the adjustment point selected in the “graph adjustment mode” Since the amount is an increase / decrease amount of ± 10% or less with respect to the full scale of the output gradation value in the gradation characteristics, the image portion can be visually recognized without a fatigue of the observer's eyes by a moderate contrast. it can. Moreover, the responsiveness of a display part can fully follow.
In addition, since the blinking cycle of the image part is 0.5 to 3 Hz or less, the image part can be clearly recognized without causing discomfort due to flicker.
Therefore, according to the projector 100, the selected image portion can be clearly recognized without giving unpleasant feeling.

(21) The blinking cycle of the image part selected by the selection cursor 51 in the “cursor adjustment mode” or the image part corresponding to the adjustment point selected in the “graph adjustment mode”, and the blinking of the dot display portion of the characteristic confirmation screen The period is synchronized.
Therefore, it can be visually recognized that the selected image portion and the dot display portion of the corresponding adjustment point on the characteristic confirmation screen indicate the same selected portion. Further, by synchronizing the period, visual discomfort is not given.
Therefore, according to the image display device of the present invention, it can be visually informed that the selected image portion corresponds to the dot display portion.

(Embodiment 2)
<< Second Image Adjustment Process Flow-1: To Branch Screen >>
FIG. 14 is a flowchart showing the flow of image adjustment up to the branch screen. FIG. 15A is a diagram illustrating an aspect of the selection screen, and FIG. 15B is a diagram illustrating an aspect of the branch screen.
Here, the flow of processing up to the branch screen in the second mode of image adjustment performed by the projector 100 according to the first embodiment will be described with reference to FIGS. To do. In addition, about the part similar to Embodiment 1, the same symbol is used and the overlapping description is abbreviate | omitted.
In the image adjustment of the second embodiment, the processing flow, the operation screen function, and the like are different from the image adjustment processing of the first embodiment. For this reason, the “tone adjustment program” that defines the order and contents of image adjustment in the second embodiment is different from the program in the first embodiment. As the operation screen, a screen having a mode different from the operation screen of the first embodiment is stored. Further, the basic γ characteristic in the “custom” characteristic has a γ value 2.4 set in advance by operating the operation unit 1.
The projector 100 is installed in an environment as shown in FIG. 1 and is operated by the operation unit 1.

In step S <b> 51, the control unit 10 confirms whether or not there is an operation for performing “gamma” adjustment based on the operation signal from the operation receiving unit 11. If there is an operation to perform “gamma” adjustment, the process proceeds to step S52. If there is no operation, it continues to wait for the operation. By this operation, the “gradation adjustment program” in the storage unit 14 is activated, and the following processing is performed according to the order and contents of the gradation adjustment defined in the program.
In step S52, the control unit 10 causes the image signal processing unit 16 to superimpose the selection screen G10 shown in FIG.
The selection screen G10 is the same as the selection screen G1 in FIG. The selection screen G10 represents a state in which the “custom” characteristic is selected, but the graph has a curve as compared with the graph of the selection screen G1. This is because the γ value 2.4 is set as the basic γ characteristic in the “custom” characteristic, so that the γ value 2.4 is represented on the scale of the graph having the γ value 2.2 as the reference linear characteristic. Because.

In step S <b> 53, the control unit 10 confirms whether there has been an operation for selecting any of the characteristics from the selection of gradation characteristics on the selection screen G <b> 10 based on the operation signal from the operation receiving unit 11. If there is a selection operation, the process proceeds to step S54. If there is no selection operation, it continues to wait for the operation.
In step S54, the control unit 10 updates the selection screen G10 according to the selected content by the image signal processing unit 16. The update content of the selection screen G10 is to select a display (for example, “2.3”) indicating the selected gradation characteristic on the left side of the screen as the selection display. At this stage, the gradation adjustment of the background image is not performed.

In step S <b> 55, the control unit 10 confirms whether or not there is an operation for determining the gradation characteristic selected by the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S56. If there is no determination operation, the process returns to step S53, and the selection operation is accepted until the determination operation is performed.
In step S56, the control unit 10 confirms whether the determined gradation characteristic is the “custom” characteristic. If it is the “custom” characteristic, the process proceeds to step S58. If it is not the “custom” characteristic, the process proceeds to step S57.
In step S57, the control unit 10 sets the γ correction data of the selected gradation characteristic in the LUT of the gamma correction unit 22, and projects an image with the gradation characteristic. Further, the process returns to step S53, and again waits for an operation for selecting gradation characteristics. At this stage, the projected image on the back side of the selection screen G10 becomes an image adjusted according to the selected gradation characteristic, and the selected gradation characteristic is displayed in a graph on the selection screen G10. In order to end the adjustment, the “Menu button” of the operation unit 1 or the remote controller 2 may be pressed according to the display at the bottom of the selection screen G10.

Next, a case where the “custom” characteristic is obtained in step S56 will be described.
In step S58, the control unit 10 causes the image signal processing unit 16 to superimpose the branch screen G11 shown in FIG. 15B on the image signal. The branch screen G11 is the same as the branch screen G2 in FIG. In the branch screen G11, the graph adjustment mode is selected.
In step S <b> 59, the control unit 10 confirms whether there has been an operation for selecting and determining the “cursor adjustment mode” based on the operation signal from the operation receiving unit 11. If there is a selection decision operation, the process proceeds to the “cursor adjustment mode” subroutine. When there is no selection decision operation, it progresses to step S60.
In step S <b> 60, the control unit 10 confirms whether or not there has been an operation for selecting and determining the “graph adjustment mode” based on the operation signal from the operation receiving unit 11. If there is a decision operation, the process proceeds to the “graph adjustment mode” subroutine. If there is no determination operation, the process returns to step S58 to wait for a selection and determination operation.

<< Second Image Adjustment Processing Flow-2: Cursor Adjustment Mode >>
FIG. 16 is a flowchart showing a flow of image adjustment in the cursor adjustment mode. FIGS. 17A and 17B are diagrams illustrating an aspect of the graph adjustment screen, and FIG. 17C is a diagram illustrating an aspect of the continuation confirmation screen.
Here, the flow of image adjustment in the cursor adjustment mode in the second mode of image adjustment of the projector 100 will be described with reference to FIGS. 17A, 17B, 17C, and FIG. explain.

In step S <b> 71, the control unit 10 causes the image signal processing unit 16 to freeze the image. This is because it is difficult to select an image part if it is a moving image.
In step S <b> 72, the control unit 10 causes the image signal processing unit 16 to superimpose the “selected cursor” on the image signal. This state is, for example, like the selection cursor 51 on the image on the screen SC of FIG.
In step S <b> 73, the control unit 10 confirms whether or not there has been an operation for determining the image portion selected by the “selection cursor” based on the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S74. If there is no selection decision operation, the decision operation is awaited.

In step S74, the control unit 10 causes the image signal processing unit 16 to blink the selected image portion and superimposes the graph adjustment screen G12 of FIG. 17A on the image signal.
In this process, first, the control unit 10 reads out image data for each color of RGB at the image portion selected by the “selection cursor” from the frame memory 17, and luminance signal data (Y signal data) from the image data of each pixel. Ask for. Next, an average value of the Y signal data excluding the maximum and minimum gradation values of the Y signal data of each pixel is obtained. Then, the adjustment point closest to the obtained Y signal data is selected as the adjustment point to be adjusted.
Further, the blinking of the selected image portion is obtained by adding the output gradation value of the selected adjustment point in the “gradation correction data” of the gradation point adjustment unit 21 (LUT) to the initial output gradation value plus 32 counts. This is done by switching every 1 Hz with a minus 32 count.
The graph adjustment screen G12 shows a state in which the adjustment point “gradation 3” is selected, and the color tone of the dot display portion D3 of the adjustment point “gradation 3” is the color tone of other display dot portions ( The color tone is different from that of white, for example, orange. Note that the display method of the dot display unit may be, for example, blinking the dot display unit in synchronization with blinking of the image portion.

On the graph adjustment screen G12, a text for prompting an adjustment “an orange part is an adjustment target. Please adjust the gradation.” Is displayed, and the adjustment state of the adjustment point corresponding to the selected image portion An indicator 55 for confirming the above is provided. The indicator 55 enlarges and displays the adjustment status as the dot display portion of the selected adjustment point moves up and down due to the adjustment.
Note that the position and size of the graph adjustment screen G12 displayed on the image are the same as those of the characteristic confirmation screen G3 of FIG. 11, and the image signal processing unit 16 does not overlap with the image portion selected by the selection cursor 51. It is controlled by.

In step S <b> 75, the control unit 10 confirms whether there is an operation for adjusting the output gradation value based on the operation signal from the operation receiving unit 11. If there is an adjustment operation, the process proceeds to step S76. If there is no adjustment operation, it waits for the adjustment operation.
In step S76, the control unit 10 causes the image signal processing unit 16 to stop blinking of the image portion, and sequentially sets the adjusted “gradation correction data” in the LUT of the gradation point adjustment unit 21, An image with the gradation characteristics is projected. Furthermore, the graph adjustment screen is updated, and as shown in the graph adjustment screen G13 in FIG. 17B, the graph display reflects the adjustment contents and the characters “Please check the adjustment result” are displayed. At this stage, the projected image on the back side of the graph adjustment screen G13 is an image that has been adjusted in real time by the gradation characteristics corresponding to the adjustment contents.

In step S <b> 77, the control unit 10 confirms whether or not there has been an operation for determining the adjustment content based on the operation signal from the operation receiving unit 11. If there is a determination operation, the process proceeds to step S78. If there is no determination operation, the process returns to step S75, and the adjustment operation is accepted until the determination operation is performed.
When there is a determination operation, the contents adjusted so far are stored in the storage unit 14 as “tone correction data” of “custom” characteristics.

In step S78, the control unit 10 causes the image signal processing unit 16 to superimpose the continuation confirmation screen G14 of FIG. The continuation confirmation screen G14 displays a confirmation display for confirming whether or not to continue the adjustment in the cursor adjustment mode.
In step S <b> 79, the control unit 10 confirms whether or not there is an operation for continuing the adjustment based on the operation signal from the operation receiving unit 11. If there is a continuation operation, the process returns to step S72, and the adjustment in the cursor adjustment mode is continued using the “tone correction data” adjusted so far as the base data. If there is no continuation operation, the continuation confirmation screen G14 is closed and the adjustment in the cursor adjustment mode is ended.

<< Second Image Adjustment Process Flow-3: Graph Adjustment Mode >>
FIG. 18 is a flowchart showing the flow of image adjustment in the graph adjustment mode. FIGS. 19A and 19B are diagrams illustrating an aspect of the graph adjustment screen.
Here, the flow of image adjustment in the graph adjustment mode in the second mode of image adjustment of the projector 100 will be described with reference to FIGS.

In step S <b> 81, the control unit 10 causes the image signal processing unit 16 to freeze the image. This is because it is difficult to select an image part if it is a moving image.
In step S82, the control unit 10 causes the image signal processing unit 16 to superimpose the graph adjustment screen G15 of FIG. The graph adjustment screen G15 is displayed in a state where the adjustment point “gradation 1” is selected, and the image portion corresponding to the adjustment point “gradation 1” blinks at a cycle of 1 Hz. Further, the color tone of the dot display portion D1 at the adjustment point “tone 1” is a color tone different from the color tone (white) of the other display dot portions, for example, orange.
On the graph adjustment screen G15, an operation explanation text is displayed, and an indicator 55 for confirming the adjustment status of the selected adjustment point is provided.
In step S <b> 83, the control unit 10 confirms whether an operation for selecting an adjustment point has been performed based on an operation signal from the operation receiving unit 11. If there is a selection operation, the process proceeds to step S84. If there is no selection operation, the selection operation is awaited.

In step S84, the control unit 10 causes the image signal processing unit 16 to blink the image portion corresponding to the selected adjustment point at a cycle of 1 Hz. Also, the color tone of the dot display portion of the selected adjustment point on the graph adjustment screen is changed to orange. It should be noted that the blinking of the image portion is determined by setting the output gradation value of the adjustment point selected in the “gradation correction data” of the gradation point adjustment unit 21 (LUT) to the initial output gradation value plus 32 counts and minus 32 counts. Then, it is performed by switching every 1 Hz period.
In step S <b> 85, the control unit 10 confirms whether there is an operation for adjusting the output gradation value based on the operation signal from the operation receiving unit 11. If there is an adjustment operation, the process proceeds to step S86. If there is no adjustment operation, it waits for the adjustment operation.
In step S86, the control unit 10 causes the image signal processing unit 16 to stop blinking of the image portion, and sequentially sets the adjusted “gradation correction data” in the LUT of the gradation point adjustment unit 21, An image with the gradation characteristics is projected. Furthermore, the graph adjustment screen is updated to display a graph reflecting the adjustment contents. At this stage, the projected image on the back of the graph adjustment screen is an image that has been image-adjusted in real time with gradation characteristics corresponding to the adjustment content.

In step S <b> 87, the control unit 10 confirms whether or not there has been an operation for determining the adjustment content based on the operation signal from the operation receiving unit 11. When there is a determination operation, the graph adjustment screen G16 is closed and the adjustment is terminated. If there is no decision operation, the process returns to step S83, and selection and adjustment operations are accepted until the decision operation is performed.
The graph adjustment screen G16 in FIG. 19B shows a state where a plurality of selection and adjustment operations have been performed. Since the output gradation value of the adjustment point “gradation 2 to 7” has been adjusted by multiple adjustments, the gradation characteristic is different from the gradation characteristic that is the base of the graph adjustment screen G15. .

As described above, according to the present embodiment, the following effects can be obtained in addition to the effects of the first embodiment.
(1) When a custom characteristic is selected, the adjustment mode is smaller than an image including a graph indicating the default gradation characteristic of the custom characteristic, regardless of whether the adjustment mode is “cursor adjustment mode” or “graph adjustment mode”. A graph adjustment screen is displayed, and the graph adjustment screen has a plurality of dot display portions for indicating an output gradation level for each of a plurality of adjustment points provided in accordance with an input gradation level and adjusting a gradation characteristic. Therefore, the gradation characteristic itself can be adjusted while confirming the initial gradation characteristic of the custom characteristic on the graph adjustment screen.
Accordingly, the projector 100 can perform image quality adjustment in accordance with the user's preference while confirming the gradation characteristics from the graph.

(2) The image signal processing unit 16 blinks the image portion corresponding to the selected adjustment point at a cycle of 1 Hz, and changes the color tone of the dot display portion of the selected adjustment point on the graph adjustment screen to orange. It is possible to visually recognize that the blinking image portion corresponds to the orange gradation point in the gradation characteristics.
Accordingly, the projector 100 can visually notify the user that the selected image portion corresponds to the dot display unit.

(3) The image signal processing unit 16 responds to the gradation level adjustment operation on the graph adjustment screen according to the output gradation level on which the gradation value of the image portion corresponding to the adjustment point in the still image is adjusted. Since the adjustment is performed sequentially, an image including the adjustment contents can be confirmed in real time during the adjustment.
Further, the adjustment state of the gradation characteristic can be confirmed in real time by using the graph and the indicator 55 on the graph adjustment screen.
Therefore, the projector 100 can confirm in real time an image including the adjustment state of the gradation characteristics and the adjustment contents at the stage of adjustment.

(4) The operation screen displayed in the “graph adjustment mode” is only the graph adjustment screen, and all adjustment operations can be completed by one type of operation screen, so that the operation efficiency is good.
In addition, after the adjustment of one adjustment point is completed, the adjustment efficiency can be improved because the adjustment of another adjustment point can be continuously performed without requiring a determination operation or continuation confirmation. Furthermore, since the adjusted gradation characteristics can be viewed in real time with graphs and images, it is easy to grasp the adjustment status.
Accordingly, the projector 100 is easy to use and can perform image quality adjustment according to the user's preference.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below.

(Modification 1)
This will be described with reference to FIG. In each of the embodiments described above, the selection of the image part and the adjustment of the output gradation value in the cursor selection mode are performed from the “up / down button” or “left / right button” of the operation unit 1 or the remote controller 2. It is not limited. For example, a trackball is installed as a pointing device in the remote controller 2, a device driver corresponding to the trackball is stored in the storage unit 14, and an image part is selected and an output gradation value is adjusted by operating the trackball. It may be to do.
According to this configuration, the projector 100 can perform the adjustment operation efficiently.

(Modification 2)
This will be described with reference to FIG. In each of the embodiments and the modifications described above, “gradation point adjustment” and “γ correction” are described as being performed using the Y signal of the YUV signal, but the present invention is not limited to this.
For example, the storage unit 14 is provided with a luminance table for assigning luminance data for each corresponding color signal from each pixel data of the RGB signal, and “tone point adjustment” and “ It is also possible to perform “γ correction”.
Even with this configuration, it is possible to obtain the same functions and effects as in the above embodiments and modifications.

(Modification 3)
This will be described with reference to FIG. In each of the above-described embodiments and modifications, the projector 100 has been described as a liquid crystal three-plate projection projector using three liquid crystal light valves 5R, 5G, and 5B as light modulation elements. However, the present invention is not limited to this. .
For example, a projector may have a configuration using a single-plate liquid crystal light valve in which red, green, and blue color filters are regularly arranged in a grid pattern and one sheet can emit full-color modulated light. good. Further, a configuration using a reflective liquid crystal display device or a tilt mirror device may be used. Further, the present invention is also suitable for a rear projector that is a projector including such a light modulation element and a screen.
Even if it is these structures, the effect similar to each said embodiment and modification can be acquired.

(Modification 4)
This will be described with reference to FIG. In each of the embodiments and the modifications described above, the image display device is described as being a projector, but is not limited to a projector. The image display apparatus may be an image display apparatus that displays an image represented by the input image signal on the display unit.
For example, the present invention can be applied to a CRT display, a liquid crystal display, a plasma display, an organic EL display, a field emission display, etc., and can obtain the same effects as those of the above embodiments and modifications. it can.

  DESCRIPTION OF SYMBOLS 1 ... Operation part, 2 ... Remote control as operation part, 3 ... Lamp as light source part, 5R, 5G, 5B ... Liquid crystal light valve as display part, 7 ... Projection lens, 10 ... Control part, 14 ... Memory | storage part, DESCRIPTION OF SYMBOLS 16 ... Image signal processing part, 18 ... OSD memory, 19 ... Scaler part, 20 ... OSD part, 21 ... Tone point adjustment part, 22 ... Gamma adjustment part, 23 ... CPU part, 51 ... Selection cursor, 52 ... Pixel selection , 53 ... annular part, 100 ... projector as an image display device, 200 ... image signal supply device, gradation 1 to gradation 9 ... adjustment point, D1 to D9 ... dot display part, G1, G10 ... selection screen, G2 , G11: Branch screen, G3, G5, G7, G9: Characteristic confirmation screen, G4, G8: Gradation adjustment screen, G6, G14: Continuation confirmation screen, G12, G13, G15, G16 ... Graph adjustment screen, Vin, D in, Dcs, Vout ... Image signal, SC ... Screen.

Claims (8)

An image display device that displays an image represented by an image signal on a display unit,
A characteristic confirmation screen including a selection cursor for selecting a desired image portion on the image, a graph indicating a correlation between input and output gradation levels of gradation characteristics in the initial setting of the image, and a floor of the image An OSD unit for superimposing a gradation adjustment screen for adjusting the gradation for each of a plurality of adjustment points in the gradation characteristics on the image signal;
An operation unit for performing at least an operation for starting adjustment of gradation characteristics of the image, an operation for selecting the image part by the selection cursor, and an operation for determining the selected image part;
When an image adjustment including adjustment of the gradation characteristics is performed on the image signal, and the operation for performing the image adjustment is performed on the operation unit, the image is stopped and the selection cursor is displayed on the display unit by the OSD unit. An image signal processing unit to be displayed on
The OSD unit blinks the adjustment point corresponding to the gradation of the selected image region or changes the color tone of the adjustment point when the operation unit is operated to select the image region by the selection cursor. Superimposing the changed characteristic confirmation screen on the image signal,
Further, when an operation for determining the selected image region is performed on the operation unit, a gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image region is superimposed on the image signal. An image display device. The image signal processor is
A gamma correction unit for correcting any one of a plurality of basic gradation characteristics predetermined in order to make the gradation characteristic specific to the display unit suitable for at least an installation environment. When,
A gradation point adjustment unit that adjusts an output gradation value for each of a plurality of adjustment points provided according to an input level in the basic gradation characteristic,
The gradation adjustment to the image signal by the image signal processing unit is performed by gradation characteristics obtained by combining the gradation correction in the gamma correction unit and the gradation adjustment in the gradation point correction unit,
When the output gradation value is adjusted on the gradation adjustment screen of the selected adjustment point, the gradation point adjustment unit changes the output gradation value of the adjustment point according to the adjustment content. The image display device according to claim 1. The selection cursor includes a pixel selection unit having a size for selecting a plurality of continuous pixels of three or more pixels in the pixels of the display unit,
The adjustment point of the gradation characteristic corresponding to the selected image part is an average value of gradation values for each of the plurality of pixels selected by the pixel selection unit, or a plurality of selection points selected by the pixel selection unit. The image display apparatus according to claim 1 or 2, wherein an adjustment point of an input gradation level closest to an average value excluding the maximum and minimum gradation values in gradation values for each pixel is selected.   4. The image display device according to claim 1, wherein the pixel selection unit has a size for selecting a total of nine pixels in a square shape composed of three pixels each in length and width. 5. The selection cursor further includes an annular part including a shape obtained by enlarging a part of the outer shape of the pixel selection part on the outer periphery of the pixel selection part,
5. The image display device according to claim 1, wherein the annular portion always maintains a relative position to the pixel selection unit and moves on the still image together with the pixel selection unit. .   In the selection operation of the image part by the selection cursor, the position of the image selection unit is controlled by the image signal processing unit so that the entire image selection unit does not protrude from the still image, and the image selection unit 6. When the edge of the still image is reached, the selection cursor is displayed in a state where a part of the image of the annular portion protruding from the still image is missing. The image display device according to one item. The color of the selection cursor is set to either white or black,
The OSD unit adjusts the color tone of the selection cursor to a color tone having a higher contrast between a color tone of the image portion selected by the selection cursor and a color tone of white or black. The image display device according to any one of claims 1 to 6. Display unit for displaying an image represented by an image signal, a selection cursor for selecting a desired image portion on the image, and correlation between input and output gradation levels of gradation characteristics in the initial setting of the image An OSD unit that superimposes on the image signal a characteristic confirmation screen including a graph representing the image, and a gradation adjustment screen for adjusting gradations for each of a plurality of adjustment points in the gradation characteristic of the image, and at least a scale of the image An operation unit for starting adjustment of tone characteristics, an operation for selecting the image part by the selection cursor, and an operation for determining the selected image part, and adjustment of the gradation characteristic for the image signal. An image signal processing unit for performing image adjustment including an image adjustment method for an image display device comprising:
When the operation for performing the image adjustment is performed, the step of causing the image to stand still and displaying the selection cursor on the display unit;
When the operation of selecting the image part with the selection cursor is performed, the characteristic confirmation screen in which the adjustment point corresponding to the gradation of the selected image part blinks or the color tone of the adjustment point is changed is displayed. Superimposing on the image signal;
A step of superimposing a gradation adjustment screen of the adjustment point corresponding to the gradation of the selected image portion on the image signal when an operation for determining the selected image portion is performed. An image adjustment method for an image display device.