JP2007293139A - Display device and on-vehicle display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device having a multiple view display function, in which one image does not spoil visibility of another image. <P>SOLUTION: The display device comprises: first and second screens formed on a common display section, which are visible from first and second viewing fields respectively; a display control section 10 for displaying first and second images on the first and second screens respectively; and an image quality adjusting section 30 for adjusting image quality of at least one of the first and the second images. The display control section 10 allows an image adjusting section 30 to adjust the image quality of at least one of the first and the second images according to one luminance of at least one of the first and the second images. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device having a so-called multiview function.

As a so-called multi-view display in which different images can be visually recognized from different directions on a common (single) display screen, for example, a parallax barrier is provided in front of the liquid crystal panel, and light from the backlight is supplied for each pixel. There is known one that can display different information (images) on the left and right by sorting the traveling directions (see, for example, Patent Document 1). By mounting such a display device on the vehicle, the passenger in the passenger seat watches other images such as a TV and a DVD on the passenger seat side screen while the driver views the navigation image on the driver seat side screen. It becomes possible.
JP 2005-78080 A

By the way, in the above display device, there may occur a state in which an image displayed on one screen is reflected on the other screen. In particular, in a predetermined area on the screen where the luminance difference between one image and the other image is large, a phenomenon in which an image with high luminance appears in an image with low luminance may occur. Due to such a phenomenon of reflection, for example, a high-brightness TV image on the passenger seat side may be reflected on a navigation image with low luminance on the driver side, making it difficult for the driver to visually recognize the navigation image.
On the other hand, when such a display device is mounted on a vehicle and a television signal is received and the content is displayed on a screen, the electric field strength of the television signal is reduced when passing through a building shadow or a tunnel. As a result, there is a problem in that the noise of the TV image increases and the visibility of the TV image decreases.
Due to such an increase in the noise of the TV image, the brightness of the TV image is lowered, and the above-mentioned reflection phenomenon also occurs on the passenger seat side, which may make it difficult to view the TV image on the passenger seat side.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display device having a multi-view display function in which one image does not deteriorate the visibility of the other image. It is to be. Another object of the present invention is to provide an in-vehicle display device having a multi-view display function with improved visibility even when receiving a weak electric field of a television signal.

The object is to form first and second screens formed on a common display unit and visible from the first and second visual fields, respectively, and the first and second images on the first and second screens, respectively. Display control means for displaying, and image quality adjustment means for adjusting the image quality of at least one of the first and second images, wherein the display control means includes at least one of the first and second images. This can be achieved by a display device that causes the image quality adjusting means to adjust the image quality of at least one of the first and second images according to the luminance.
With this configuration, the image quality is adjusted according to the luminance of at least one of the first and second images, so that one image does not deteriorate the visibility of the other image.

In addition, the object is to display a separate image for two viewing directions on the driver seat side and the passenger seat side on the same screen, to display a driver seat image on the driver seat side, and on the passenger seat side A display control means for displaying a passenger seat image, a receiving means for receiving a television signal, a detection means for detecting the electric field strength of the television signal, and adjusting the image quality of at least one of the driver seat image and the passenger seat image. Image quality adjusting means, and the display control means, when displaying the image of the television signal on one of the driver seat image and the passenger seat image, the electric field strength detected by the detecting means, and the driving This can be achieved by a vehicle-mounted display device that causes the image quality adjusting means to adjust the image quality of at least one of the driver seat image and the passenger seat image according to the brightness of at least one of the seat image and the passenger seat image.
With this configuration, the image quality is adjusted according to the electric field strength of the television signal and the brightness of at least one of the driver seat image and the passenger seat image, so that one image does not deteriorate the visibility of the other image. The visibility can be improved even when a TV signal receives a weak electric field.

In the above configuration, the display control unit may adjust the image quality of at least one of the first and second images to reduce the luminance difference between the first and second images.
According to this configuration, since the luminance difference between the first and second images is reduced, the reflection phenomenon can be effectively reduced.

In the above configuration, the display control unit may employ a configuration in which the image quality is adjusted for each predetermined number of frames.
According to this configuration, since the image quality is adjusted for each predetermined number of frames, it is possible to perform image quality adjustment that is comfortable for the viewer.

In the above configuration, the display control unit may adjust at least one of luminance, contrast, color tone, and gamma value.
According to this configuration, the reflection can be reduced by adjusting any one of the luminance, contrast, color tone, and gamma value.

  According to the present invention, when one image reduces the visibility of the other image, for example, when the brightness of the other image decreases, or when the brightness difference between both images is significant, different display contents are displayed. In this case, the reflection can be suppressed and the visibility can be improved.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram for explaining a basic configuration of a vehicular multi-view display device according to an embodiment of the present invention.
As shown in FIG. 1, this in-vehicle display device includes a display control unit 10 as a display control unit, a display unit 100, and the like.
The display control unit 10 is supplied with the image data DT1 from the first image source 300A and the image data DT2 from the second image source 300B, and includes the first and second image data DT1 and DT2. The image data ADT is output to the common display unit 100. A specific configuration of the display control unit 10 will be described later. The first and second image sources 300A and 300B are, for example, a video signal source 250 including an analog TV tuner, a digital TV tuner, a DVD playback unit, an HDD (Hard Disk Drive) 50 storing map information, and the like. Consists of

  As will be described later, the display unit 100 includes a liquid crystal panel, a backlight, a parallax barrier, and the like, and displays a first image IM1 based on the first image data DT1 in the right direction (driver's seat (hereinafter referred to as D seat). The driver's seat screen (D seat screen) that can be viewed by the observer OBR from the side view) and the second image IM2 based on the second image data DT2 are leftward (passenger seat (hereinafter also referred to as P seat)). Side) and a passenger seat screen (P seat screen) that can be viewed by the observer OBL. A specific configuration of the display unit 100 will be described later.

FIG. 2 is a diagram showing a vehicle-mounted display device mounted on a vehicle, and FIG. 3 is a cross-sectional view showing the structure of a display unit.
As shown in FIG. 2, the display unit 100 of the in-vehicle display device is built in, for example, a dashboard portion of the vehicle, and the display unit 100 includes a driver seat DS and a passenger seat AS as shown in FIG. Arranged between.
Further, as shown in FIG. 2, an operation panel 150 including a plurality of operation buttons for various operations is provided below the display unit 100.
An occupant seated in the driver seat DS becomes the observer OBR, and an occupant seated in the passenger seat AS becomes the observer OBL. These passengers can simultaneously view the first image IM1 and the second image IM2 displayed on the display unit 100 from the driver seat DS side or the passenger seat AS side, respectively.

  As shown in FIG. 3, the display unit 100 includes a liquid crystal panel 110, a backlight 120 that receives illumination light from the back side of the liquid crystal panel 110, a touch panel 130 (not shown) provided on the front side of the liquid crystal panel 110, and the like. ing.

As shown in FIG. 3, the liquid crystal panel 110 is a color filter substrate having a polarizing plate 111, a TFT (Thin Film Transistor) substrate 112, a liquid crystal layer 113, and pixels of three primary colors RGB arranged in order from the backlight 120 side. 114, a parallax barrier 115, a glass plate 116, a polarizing plate 117, and the like.
The liquid crystal panel 110 has, for example, a display screen in which 800 pixels in the horizontal direction and 480 pixels in the vertical direction are arranged. The display screen includes a left display pixel 118 and a right display pixel 119 in the horizontal direction. Are arranged alternately.

As shown in FIG. 3, the parallax barrier 115 is formed in a stripe shape and includes a shielding part and a light-transmitting part, and the shielding part is disposed between the adjacent left display pixel 118 and right display pixel 119. Is done. By disposing the parallax barrier 115 on the front surface of the color filter substrate 114, the illumination light transmitted through the left display pixel 118 selectively passes through the light-transmitting part of the parallax barrier 115 selectively toward the left side, and is displayed on the right side. Of the illumination light transmitted through the pixel 119, only the illumination light directed toward the right side selectively passes through the light transmitting portion of the parallax barrier 115. As a result, as shown in FIG. 3, the first image IM1 can be viewed from the right side (driver's seat side) of the liquid crystal panel 110, and the second image IM2 can be viewed from the left side (passenger seat side). ing.
The parallax barrier 115 can be the same as those disclosed in JP-A-10-123461 and JP-A-11-84131.

4 is a functional block diagram of the in-vehicle display device, and FIG. 5 is a functional block diagram of the image processing circuit.
As shown in FIG. 4, the display control unit 10 includes a processor (CPU) 11, a RAM (random access memory) 12, a ROM (read only memory) 13, a drawing circuit 20, an image processing circuit 30, a video selection circuit 40, and the like. Composed.

  The display control unit 10 displays the electric field intensity detected by the electric field intensity detection unit 260, the first image IM1, the second image IM2, and the first image IM1 and the second image IM2 when displaying the image of the television signal on one of the first image IM1 and the second image IM2. The image processing circuit 30 is caused to adjust the image quality of at least one of the first image IM1 and the second image IM2 in accordance with the luminance of at least one of the second images IM2. Details will be described later.

The processor 11 is connected to the RAM 12, the ROM 13, the drawing circuit 20, and the like via the bus BUS so as to be able to exchange various data, and the image processing circuit 30, the video selection circuit 40, the HDD 50, the sound processing circuit 80, the touch panel 130, An operation panel 150 is also connected, and the entire apparatus is comprehensively controlled by executing a program stored in the ROM 13.
The RAM 12 stores various data necessary for control by the processor 11.

  The drawing circuit 20 receives drawing parameters from the processor 11 through the bus BUS, forms drawing image data RGB, and outputs this to the image processing circuit 30. Specifically, the drawing circuit 20 draws images such as navigation images (maps, menu images, etc.), audio setting images such as analog TV, digital TV, and DVD.

The TV receiver 252 receives a television signal and outputs an NTSC signal to the video selection circuit 40.
The electric field strength detector 260 detects the electric field strength from the television signal received by the TV receiver 252 and outputs the electric field strength data to the processor 11.

The video selection circuit 40 receives a selection signal SEL from the processor 11 from various video signal data supplied from the DVD playback unit 251, the TV reception unit 252, and the like, and selects one video signal data CMP. Output to the circuit 30. When the video signal data is supplied from the TV receiver 252, an NTSC signal is output to the image processing circuit 30 as the video signal data CMP.
The processor 11 generates a selection signal SEL according to signals from the operation panel 150, the touch panel 130, and the like.

  The image processing circuit 30 adjusts the image quality of at least one of the first image IM1 and the second image IM2. Specifically, as shown in FIG. 5, the image processing circuit 30 includes a video signal image quality adjusting unit 31, a drawn image image quality adjusting unit 32, a TFT timing control circuit 360, and the like.

  The video signal image quality adjustment unit 31 includes an A / D conversion circuit 301A, a contrast adjustment circuit 302A, a luminance adjustment circuit 303A, a color tone adjustment circuit 304A, a gamma value adjustment circuit 305A, an enlargement / reduction circuit 306A, and the like.

The A / D conversion circuit 301 converts the video signal data CMP consisting of an analog signal into a digital signal and sends it to the contrast adjustment circuit 302A.
The contrast adjustment circuit 302A, the brightness adjustment circuit 303A, the color tone adjustment circuit 304A, and the gamma value adjustment circuit 305A change the image quality (contrast, brightness, tone, gamma value) of the first image data in accordance with a control command from the processor 11. adjust.

  The enlargement / reduction circuit 306A performs enlargement / reduction processing on the video signal data CMP at an arbitrary magnification in the horizontal and vertical directions, and outputs the result to the TFT timing control circuit. Note that the expansion / contraction circuit 306A is controlled by a control signal from the processor 11.

  Similarly to the video signal image quality adjustment unit 31, the drawn image image quality adjustment unit 32 also includes an A / D conversion circuit 301B, a contrast adjustment circuit 302B, a luminance adjustment circuit 303B, a color tone adjustment circuit 304B, a gamma value adjustment circuit 305B, and an enlargement / reduction circuit 306B. Etc.

  The luminance difference calculation circuit 370 calculates the difference between the luminance of the video signal data CMP converted into the digital signal and the luminance of the drawing image data converted into the digital signal, and outputs the information to the processor 11.

  In FIG. 5, the TFT timing control circuit 360 generates a control signal for the liquid crystal driving circuit (TFT) of the liquid crystal panel 110 based on the data obtained from the expansion / contraction circuits 306 </ b> A and 306 </ b> B and outputs the control signal to the liquid crystal panel 110.

The HDD 50 stores map information, audio information, and the like. These pieces of information are read by the processor 11, and the map information is output to the drawing circuit 20 as drawing parameters by the processor 11.
The audio processing circuit 80 reproduces the audio data from the processor 11 and outputs it from the speaker SP.

  The touch panel 130 is formed in a transparent sheet shape and is attached to the front surface of the liquid crystal panel 110 described above. When a driver or passenger in the driver's seat operates the operation buttons or the like displayed on the screen of the liquid crystal panel 110. The position touched by the passenger's finger or the like is detected and output to the processor 11.

Next, an example of displaying images on the D seat screen and the P seat screen of the liquid crystal panel 110 by the display control unit 10 will be described with reference to FIG.
FIG. 6A shows a state in which a map image as a drawing image is displayed on the D seat screen, and at the same time, a television image is displayed on the P seat screen.

When the display shown in FIG. 6A is performed, the display control unit 10 provides the drawing circuit 20 with the drawing parameters of the operation buttons together with the map information from the HDD 50 and draws the D seat screen as RGB data. Output and display for the D seat screen.
On the other hand, for the P seat screen, the video selection circuit 40 selects the television as the video signal data CMP, and the image processing circuit 30 converts it into RGB data, which is then output to the TFT timing control circuit 360 for the P seat screen. As output.

Next, a display example in a case where an image is disturbed due to a decrease in electric field strength when receiving a television signal will be described. FIG. 6B illustrates a display example in the case where the TV image displayed on the P seat screen is disturbed due to a decrease in the electric field strength when receiving a TV signal.
When the electric field strength of the television signal is reduced, the television image is disturbed and the luminance is generally lowered. When the brightness of the TV image decreases, a phenomenon may occur in which the map image displayed on the D seat screen is reflected on the P seat screen. This is a phenomenon in which a high-brightness image appears on a screen on which a low-brightness image is displayed due to a luminance difference between the image displayed on the D-seat screen and the image displayed on the P-seat screen. An image with high brightness displayed on the screen diffracts the parallax barrier 115 and leaks to the other screen.
As described above, when the electric field strength of the TV signal is reduced, the luminance is lowered and the visibility is deteriorated, and the image displayed on the D seat screen is reflected on the P seat screen, and the image displayed on the P seat screen is changed. Visibility is further deteriorated.

Next, an example of the reflection reduction process by the display control unit will be described. FIG. 7 is a flowchart illustrating an example of the reflection reduction process performed by the display control unit. This process is executed at a constant cycle while the vehicle-mounted display device is powered on.
Based on the signal from the video selection circuit 40, the processor 11 determines whether a TV image is displayed on either the D seat screen or the P seat screen (step S1). If no TV image is displayed on any screen, this process is terminated.

  The processor 11 determines whether or not the electric field intensity level of the television signal detected by the electric field intensity detector 260 is less than a predetermined threshold (step S2). If the electric field intensity level is equal to or higher than a predetermined threshold, it is determined that an undisturbed television image is displayed, and this process is terminated.

If the electric field intensity level is less than the predetermined threshold, the luminance difference between the television image and the drawn image is calculated (step S3).
Here, the luminance difference is calculated by the luminance difference calculation circuit 370 according to the following equation.

このように、描画画像の各３原色毎のＤ／Ａ３０１Ｂへの入力値の平均値から、テレビ信号のＤ／Ａ３０１Ａへの入力値を減算することにより、テレビ画像と描画画像との輝度差を算出する。
また、輝度差演算回路３７０は、各画像の輝度を算出するために、各画像の所定の領域内においての輝度を算出する。
尚、この輝度差の算出は、１フレーム毎に行ってもよいし、数フレーム毎に行ってもよい。

In this way, by subtracting the input value to the D / A 301A of the TV signal from the average value of the input values to the D / A 301B for each of the three primary colors of the drawn image, the luminance difference between the TV image and the drawn image is obtained. calculate.
Further, the luminance difference calculation circuit 370 calculates the luminance within a predetermined area of each image in order to calculate the luminance of each image.
The calculation of the luminance difference may be performed every frame or every several frames.

  Next, it is determined whether or not the calculated brightness difference value is larger than a predetermined threshold value (step S4). If this luminance difference is small, the process is terminated because the degree of the reflection phenomenon is small.

  When the calculated luminance difference is larger than a predetermined threshold, the processor 11 issues a command to the video signal image quality adjustment unit 31 and the drawn image image quality adjustment unit 32 to perform image quality adjustment for reducing the reflection phenomenon. (Step S5). Specifically, the processor 11 issues a command to the contrast adjustment circuits 302A and 302B, the brightness adjustment units 303A and 303B, the color tone adjustment circuits 304A and 304B, the gamma value adjustment circuits 305A and 305B, and the like, thereby reducing the reflection phenomenon. Adjust the image quality.

For example, as illustrated in FIG. 6B, when an image with low luminance is displayed on the P seat screen and an image with high luminance is displayed on the D seat screen, the processor 11 includes the luminance adjusting unit 303 </ b> A, A command is issued to 303B to adjust the image quality so that the brightness of the image displayed on the P seat screen is increased and the brightness of the image displayed on the D seat screen is decreased.
Further, the processor 11 reduces the contrast of the television image displayed on the P seat screen, changes the color tone to green, changes the color intensity lightly, or adjusts the gamma value to adjust the image. You may adjust so that the difference between black and white may be made small.
The processor 11 performs the image quality adjustment every predetermined number of frames. Specifically, image quality adjustment is performed for one frame out of 30 frames.

  As described above, the display control unit 10 displays the content of the television signal on one of the P seat screen and the D seat screen, and at least one image quality of the first and second images according to the electric field strength of the television signal. Is adjusted to reduce the reflection of one of the first and second images on the screen on which the other image is displayed. According to this configuration, by adjusting the image quality of at least one of the first and second images according to the electric field strength of the television signal, the deterioration of the reflection phenomenon can be prevented when the television signal receives a weak electric field. Visibility can be improved.

Further, the display control unit 10 adjusts the image quality of at least one of the first and second images according to the luminance difference between the first and second images. According to this configuration, by adjusting the image quality of at least one of the first and second images in accordance with the luminance difference, the image quality is adjusted when the reflection phenomenon is likely to occur, so that the visibility can be improved. it can.
Moreover, since the display control unit 10 reduces the luminance difference between the first and second images, it is possible to effectively reduce the reflection phenomenon.
Further, since the display control unit 10 adjusts the image quality for each predetermined number of frames, it is possible to perform image quality adjustment that is comfortable for the viewer.

FIG. 8 is a display example of an image on the D seat screen and the P seat screen of the liquid crystal panel 110 when image quality adjustment is performed on each sub screen.
The display control unit 10 calculates the luminance difference from the drawing image displayed on the D seat screen for each sub screen displayed on the P seat screen, and executes the reflection reduction process for each sub screen. May be.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

In the above embodiment, the image quality adjustment is performed according to the electric field strength and the luminance difference of the television signal. However, the present invention is not limited to this, and the luminance difference between the first image and the second image is greater than or equal to the threshold value. If the luminance of one of the first and second images is reduced, if the first and second images are different, or if the electric field strength of the television signal is reduced, the first and second images Image quality adjustment of at least one of the images may be performed. That is, it is sufficient to adjust the image quality of at least one of the first and second images to reduce the reflection phenomenon as long as the luminance can change.
In order to determine whether one of the luminances has decreased, for example, the processor 11 can determine the decrease in luminance by monitoring signals from the A / D conversion circuits 301A and 301B.

  In order to determine whether or not the first and second images are different, for example, the operation content of the display on each screen by the operation panel 150 is selected, the selection state of the video selection circuit 40 or the drawing circuit 20 is used for drawing. It can be determined by the processor 11 controlling whether the drawn content is for the first screen and the second screen. Thus, the reason for adjusting the brightness when the first image and the second image are different is that they are displayed on the first and second screens because the brightness of the source such as DVD or navigation image is different. Differences in luminance and display content may occur. Therefore, when the source and contents displayed on the first screen and the second screen are different, the image quality adjustment of at least one of the first and second images is performed to reduce the reflection due to the difference in luminance. Can do.

  In the above embodiment, the case where the image quality adjustment is performed for both the TV image displayed on the P seat screen and the drawing image displayed on the D seat screen has been described, but only one of the images may be adjusted. .

  In the above-described embodiment, the case where the image quality adjustment is performed by reducing the brightness of an image with high brightness and increasing the brightness of an image with low brightness has been described. However, the present invention is not limited to such image quality adjustment. The image quality may be adjusted to lower the brightness. Further, the image quality adjustment may be performed so that the luminance is increased only for the low luminance image.

  In the above embodiment, the in-vehicle display device has been described. However, the present invention is not limited to such a configuration, and for example, a home display device having a multi-view function may be used. Also, in this case, television images with different channels are displayed on both the first and second screens, and image quality adjustment is performed according to the electric field strength of the television signal of the television image displayed on at least one screen. May be.

It is a figure for demonstrating the basic composition of the multiview display apparatus for vehicles which concerns on one Embodiment of this invention. It is a figure which shows the vehicle-mounted display apparatus mounted in the vehicle. It is sectional drawing which shows the structure of a display part. It is a functional block diagram of a vehicle-mounted display device. It is a functional block diagram of an image processing circuit. It is a figure about the example of a display of the image on the D seat screen and P seat screen of a liquid crystal panel by a display control part. It is the flowchart figure which showed an example of the reflection reduction process by a display control part. It is the example of a display of the image on the D seat screen and the P seat screen of a liquid crystal panel when image quality adjustment is implemented with respect to each subscreen.

Explanation of symbols

10 Display control unit (display control means)
11 Processor 12 RAM
13 ROM
20 Drawing circuit 30 Image processing circuit (image quality adjusting means)
31 Video signal image quality adjustment unit 32 Rendered image image quality adjustment unit 40 Video selection circuit 50 HDD
80 Audio processing unit 100 Display unit 110 Liquid crystal panel 120 Backlight 130 Touch panel 150 Operation panel 251 DVD playback unit 252 TV receiving unit (receiving means)
260 Field strength detector (detection means)
301A, 301B A / D conversion circuits 302A, 302B Contrast adjustment circuits 303A, 303B Luminance adjustment circuits 304A, 304B Color tone adjustment circuits 305A, 305B Gamma value adjustment circuits 306A, 306B Enlargement / contraction circuit 360 TFT timing control circuit DS Driver's seat AS Passenger's seat

Claims (2)

First and second screens formed on a common display unit and visible from the first and second fields of view respectively;
Display control means for displaying the first and second images on the first and second screens, respectively;
Image quality adjusting means for adjusting the image quality of at least one of the first and second images,
The display control means causes the image quality adjusting means to adjust the image quality of at least one of the first and second images according to the luminance of at least one of the first and second images.
A display device characterized by that. A display unit capable of displaying individual images for two viewing directions on the driver side and passenger side on the same screen;
Display control means for displaying a driver seat image on the driver seat side and displaying a passenger seat image on the passenger seat side;
Receiving means for receiving a television signal;
Detecting means for detecting electric field strength of the television signal;
Image quality adjusting means for adjusting the image quality of at least one of the driver seat image and the passenger seat image,
The display control means, when displaying the image of the television signal on one of the driver seat image and the passenger seat image, at least one of the electric field intensity detected by the detection means and the driver seat image and the passenger seat image. The image quality adjusting means adjusts the image quality of at least one of the driver seat image and the passenger seat image according to the brightness of
A vehicle-mounted display device.

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