JP4595961B2 - Projection display - Google Patents

Description

  The present invention relates to a projection display device (projector), and more particularly to a projector having a light shielding means such as a diaphragm for improving contrast.

  Projection-type display devices that display an image by spatially modulating and emitting incident light to the spatial light modulation element according to an electrical signal applied to the spatial light modulation element and collecting and projecting the emitted light have become widespread. . Such a projection display device generally has a lamp and a condensing mirror as a light source, and also has an illumination optical system that condenses the light emitted from them and enters the spatial light modulation element. Light from the modulation element is projected onto a screen or the like by a projection lens.

  At present, typical spatial light modulators have a liquid crystal material inside and the incident polarization is rotated by the electric field applied to the liquid crystal (referred to as the liquid crystal type), and a small amount for each pixel. A type that has an operating mirror, reflects incident light with a micro-operating mirror, and performs spatial modulation by changing the holding angle of the micro-operating mirror according to a video signal (referred to as a DMD (digital micromirror device) type) ('DMD' is a registered trademark).

  FIG. 1 shows a basic configuration of a liquid crystal type projection display (liquid crystal projector). The light emitted from the light source 21 goes to the reflecting mirror 22. The reflecting mirror 22 and the illumination optical system 23 collect a lot of light in a liquid crystal element (liquid crystal panel) 25 that is a spatial light modulation element. The collected light enters the polarizer 24 before entering the liquid crystal element 25, and the unidirectional polarized light is extracted. Then, a video signal is applied to the liquid crystal element 25, and the light emitted from the polarizer 24 and incident on the liquid crystal element 25 is spatially modulated, and the polarization direction is rotated according to the video signal. The light exiting the liquid crystal element 25 enters the analyzer 26, and the projected light is selected. The light emitted from the analyzer 26 enters a projection lens 27 and is projected and displayed on a screen (not shown).

  Next, FIG. 2 shows a basic configuration of a DMD type projection display device (DMD projector). Light emitted from the light source 31 travels to the reflecting mirror 32. The reflecting mirror 32 and the illumination optical system 33 collect a lot of light in a DMD element (DMD panel) 34 that is a spatial light modulation element. A video signal is applied to the DMD element 34, and the incident light is spatially modulated, and the tilt of the micro working mirror is changed according to the video signal to change the light emitting direction. The light selected by the DMD element 34 enters the projection lens 35 and is projected and displayed on a screen (not shown).

  By the way, in the comparison of an image with a projection type display apparatus and another image display apparatus, the low contrast of a projection type display apparatus is mentioned. The contrast described here is the ratio of luminance when a white screen is displayed and when a black screen is displayed.

  In the projection type display device as shown in FIGS. 1 and 2, even if a black screen is to be displayed, a small amount of light is incident on the projection lens. This is because the light source is always operated.

  As a measure for solving this drawback, in recent years, in a projection display device, a diaphragm is installed in an illumination optical system or a projection lens (for example, see Patent Document 1).

  The reason why the contrast is increased by installing the diaphragm is as follows. In the case of a liquid crystal projector, a characteristic of the liquid crystal element is that the contrast is deteriorated as the angle of light incident on the liquid crystal panel surface is larger. For this reason, in the liquid crystal projector shown in FIG. 1, as shown in FIG. 3, a stop 41 is installed in the illumination optical system 23 or in the vicinity of the illumination optical system 23 to reduce the angle of light incident on the liquid crystal element 25. And the contrast goes up.

  Alternatively, in the liquid crystal projector shown in FIG. 1, as shown in FIG. 4, a diaphragm 41 is installed in the projection lens 27, and light beams emitted from the liquid crystal element 25 having a large incident angle to the liquid crystal panel are stopped. Contrast is also increased by shading.

  On the other hand, in the case of a DMD projector, as described above, when a black screen is displayed, light incident on the DMD element does not enter the projection lens. However, since the DMD element is an aggregate of minute mirrors, scattered light is generated between the mirrors. For this reason, light that would otherwise not be directed to the projection lens is generated. In order not to actually project this as much as possible, it is possible to increase the contrast by providing a diaphragm in the projection lens.

JP 2001-264728 A (paragraph numbers 0049 to 0054, FIG. 1)

  As described above, there is a conventional projection display device in which contrast is increased by installing a diaphragm. However, the use of a diaphragm having a constant light shielding amount (for example, an aperture diaphragm with a fixed aperture shape) has a detrimental effect that the luminance when a white screen is displayed is lowered.

  A measure for preventing this problem is to use a variable stop (a stop with a variable light shielding amount) to enable a plurality of states when the stop is open and when the cover is closed. The contrast of the projected image becomes a problem due to the brightness of the environment to project. In a bright room, the screen is exposed to light depending on the brightness of the room (such as lighting and the sun) regardless of the presence or absence of the projection display device. For this reason, even if a black screen is displayed, the floating of the black portion by the apparatus does not pose a problem due to external light. The brightness of the white screen is sufficient to cancel out the external light.

  On the contrary, when there is no outside light, the black screen will be noticeable. Conversely, since it is a dark place, the brightness of the white screen is not so necessary. This is because the human eye gets used to it.

  For this reason, in an environment with external light, the aperture is opened, white is brightened, and high brightness image expression is performed. On the other hand, in an environment where there is no external light, the diaphragm is closed to suppress white and increase the contrast. Thus, the variable aperture can achieve both luminance and contrast.

  However, when the variable aperture is opened and closed in this way, the angular distribution of the light emitted from the spatial light modulation element and reaching the screen differs between when the aperture is opened and when the aperture is closed. This is because, as described above, a part of the light incident on the spatial light modulator or a part of the light emitted from the spatial light modulator is blocked and does not reach the screen. This is a means to increase the contrast, but this may cause the following problems.

  In a liquid crystal element, the thickness of a portion (liquid crystal layer) in which liquid crystal is sealed may not be uniform depending on the surface. Even if the same level of voltage is applied to all the pixels of the liquid crystal panel, the thickness of the liquid crystal layer differs depending on the part, so that incident light may not be subjected to the same light modulation. In other words, in the liquid crystal panel, the relationship graph (VT curve) between the applied voltage (V) and the transmittance (T) does not match depending on the effective screen area.

  If this is the case, appropriate light modulation cannot be performed depending on the portion of the screen, so that a difference occurs between the applied video signal and the projected image. For example, even when a video signal having a level corresponding to a transmittance of 50% is input, the transmittance of all parts of the screen does not become 50%, and uneven brightness occurs in the projected image.

  In order to eliminate this uneven brightness, the screen of the liquid crystal panel is divided into a plurality of areas, and the video signal applied to the liquid crystal panel is corrected according to the VT curve characteristics of each area ( The present applicant has already disclosed "Uniformity correction technology" in Japanese Patent Laid-Open No. 11-113019.

  However, the VT curve changes depending on the angular distribution of light incident on the liquid crystal panel even in the same part of the screen. For this reason, the angle distribution of the light emitted from the liquid crystal panel and reaching the screen is changed by opening / closing the variable aperture (the angle distribution of the light incident on the liquid crystal panel is changed by opening / closing the variable aperture on the illumination optical system side). Or the opening and closing of the variable aperture on the projection lens side changes the angular distribution of the light projected from the projection lens when it enters the liquid crystal panel), and even with this uniformity correction technology, appropriate correction cannot be performed. , Uneven brightness may occur in the projected image.

  In the above, the case where the angular distribution of the light emitted from the liquid crystal panel and reaching the screen is changed by opening and closing the variable diaphragm has been described. The cause of the change in the angular distribution of the light emitted from the liquid crystal panel and reaching the screen is changed. In addition to this, when the zoom position of a projection lens composed of a zoom lens with a variable focal length is changed, or a liquid crystal projector in which the projection lens can be replaced, a projection lens with a different F number can be replaced. The case where it performs is mentioned.

  In view of the above points, the present invention provides a projection display device capable of performing appropriate uniformity correction even when the angular distribution of light emitted from a spatial light modulator and reaching a screen changes. It was made as an issue.

The applicant
A light source;
A spatial light modulation element that modulates and emits incident light in accordance with an applied video signal;
An illumination optical system for condensing light from the light source and illuminating the spatial light modulator,
The projection lens that projects the light emitted from the spatial light modulation element can be exchanged between a plurality of types of projection lenses having different F-numbers.
The screen of the spatial light modulation element is divided into a plurality of areas, and the video signal applied to the spatial light modulation element is divided into the screen according to the F number of the currently installed projection lens for each of the areas. A video signal correction unit that performs correction so as to compensate for the light output from the spatial light modulation element that fluctuates depending on the position of the light source, and is a reference correction according to the F number of the projection lens serving as a reference among a plurality of types of projection lenses Individual correction data storage having reference correction data storage means for storing data and storing difference data with respect to reference correction data for performing individual correction corresponding to the projection lens on the currently mounted projection lens If no means exists, correction is performed based on the reference correction data stored in the reference correction data storage means, and this individual correction is applied to the currently mounted projection lens. If the data storage means is present, with a video signal correction means for correcting, based on the reference correction data reference stored in the storage means correction data and the difference data stored in the individual correction data storage means A projection display device is proposed.

This projection display equipment, compared video signal applied to the spatial light modulator, for each of the regions obtained by dividing the screen of the spatial light modulator into a plurality of regions, among the plurality of types of projection lenses with different F-number Video signal correction means for correcting so as to compensate for the light output from the spatial light modulation element that varies depending on the position in the screen in accordance with the F number of the currently mounted projection lens is provided. Therefore, different corrections are performed on the video signal in the same part of the screen of the spatial light modulator depending on the F number of the mounted projection lens.

As described above, the video signal in the same part of the screen of the spatial light modulation element is corrected differently depending on the F number of the currently mounted projection lens, so that it is replaced with a projection lens having a different F number. As a result, even if the angular distribution of the light emitted from the spatial light modulator and reaching the screen changes, appropriate uniformity correction can be performed.
The video signal correction means has reference correction data storage means for storing reference correction data corresponding to the F number of the projection lens serving as a reference, and refers to the reference correction data from the reference correction data storage means. A correction is made by referring to the difference data from the individual correction data storage means storing the difference data with respect to the reference correction data for performing the individual correction corresponding to the projection lens which the currently mounted projection lens has. I do. Thus, even when there are many types of projection lenses that can be exchanged, appropriate uniformity correction according to the exchange of the projection lens can be performed without storing a large number of correction data in the projection display apparatus body.

  In this projection type display device, as an example, the video signal correction means includes, for each area, the characteristics of the light output level of the area with respect to the applied level of the video signal, and the F of the currently installed projection lens. It is preferable to perform correction according to the number.

  As a result, even when this characteristic of the spatial light modulation element does not coincide with each other and changes due to replacement of the projection lens, appropriate uniformity correction can be performed.

According to engagement Ru projecting elevation-type display device of the present invention, even after changing the angular distribution of light reaching the screen is emitted from the spatial light modulator by the exchange of the F-number is different from the projection lens, suitable An effect that uniform uniformity correction can be performed is obtained.
In addition, even when there are many types of projection lenses that can be replaced, it is possible to perform appropriate uniformity correction according to the replacement of the projection lens without storing a large amount of correction data in the projection display device body. Can also be obtained.

  In addition, when the characteristics of the light output level of the spatial light modulation element with respect to the applied level of the video signal do not coincide with the area of the spatial light modulation element and change due to replacement of the projection lens, appropriate uniformity correction should be performed. The effect of being able to be obtained.

  Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 5 shows an example of the configuration of a liquid crystal projector devised in connection with the present invention, and the same reference numerals are given to portions common to FIG. The light emitted from the light source 21 goes to the reflecting mirror 22. The reflecting mirror 22 and the illumination optical system 23 collect a lot of light in a liquid crystal element (liquid crystal panel) 25 that is a spatial light modulation element.

  In the vicinity of the illumination optical system 23, a variable stop 1 is installed. The variable aperture 1 is a mechanical shutter having a variable aperture area. The variable aperture drive unit 2 (a motor that displaces the operation unit of the variable aperture 1, a motor driver that drives the motor, etc.) opens the area of the aperture. Is increased or decreased.

  The light collected by the reflecting mirror 22 and the illumination optical system 23 enters the polarizer 24 through the variable stop 1 before entering the liquid crystal element 25, and the unidirectional polarized light is extracted. Then, a video signal is applied to the liquid crystal element 25, and the light emitted from the polarizer 24 and incident on the liquid crystal element 25 is spatially modulated, and the polarization direction is rotated according to the video signal. The light exiting the liquid crystal element 25 enters the analyzer 26, and the projected light is selected. The light emitted from the analyzer 26 enters a projection lens 27 and is projected and displayed on a screen (not shown).

  The operation panel and remote controller of the main body of the liquid crystal projector are not shown, but an aperture adjustment button for opening and closing the variable aperture 1 (adjusting the area of the opening in two steps, large and small). Is provided. The CPU 6 controls each part in the liquid crystal projector. When an operation for opening the variable aperture 1 is performed with this aperture adjustment button, the variable aperture drive unit 2 is controlled to open the variable aperture 1 ( On the other hand, when an operation for closing the variable aperture 1 is performed with this aperture adjustment button, the variable aperture drive unit 2 is controlled to reduce the variable aperture 1 (the area of the aperture is reduced). , Narrower than the maximum area).

  The video signal applied to the liquid crystal element 25 is corrected by the white balance adjustment unit 3 and the gamma correction unit 4. The white balance adjustment unit 3 adjusts the color temperature of the video signal. Although not shown, the white balance adjustment unit 3 adjusts the white color temperature of the video signal and the black color temperature of the video signal. And a bias circuit for adjusting. The gamma correction unit 4 performs gamma correction on the video signal from the white balance adjustment unit 3 to adjust the image quality. Although not shown, the gamma correction unit 4 has characteristics opposite to the VT curve characteristics of a general liquid crystal element. A lookup table storing curve data is provided.

  The three-dimensional correction unit 5 converts the three-dimensional interpolation data C (X, Y, Z) for the video signal of level Z at an arbitrary pixel G (X, Y) of the liquid crystal element 25 into the white balance adjustment unit 3 and the gamma correction unit. As shown in FIG. 6, a horizontal / vertical counter 11, a position block identification processing unit 12, a coordinate data storage unit 13, a position calculation processing unit 14, a three-dimensional interpolation processing unit 15, and correction data storage are provided. It consists of part 16.

  The horizontal / vertical synchronization counter 11 is a counter for specifying the surface coordinates (X, Y) of a pixel when the position of the pixel (signal) to be corrected in the display screen, that is, when the display screen is viewed as a plane. The horizontal position coordinate X output from the horizontal / vertical synchronization counter 11 is reset to zero in synchronization with the horizontal synchronization signal Hsync and is counted up for each clock CLK to represent the position of the pixel in the horizontal direction. Coordinate data. The vertical position coordinate Y output from the horizontal / vertical synchronization counter 11 is zero-reset in synchronization with the vertical synchronization signal Vsync, and is coordinate data representing the vertical pixel position counted up for each horizontal synchronization signal Hsync. It is said. The clock CLK is synchronized with the change of the pixel on the time axis and is generally called a dot clock.

  The coordinate data storage unit 13 requires correction center coordinate data (coordinate data of the center point to be corrected in the screen of the liquid crystal element 25) Xc, Yc and correction range coordinate data (correction in the screen of the liquid crystal element 25). A register is provided for storing the coordinate data X1, X2, Y1, Y2 of the range to be corrected, and the data Z1, Z2 of the range of the video signal level to be corrected, and this register is factory adjusted. In some cases, correction center coordinate data and correction range coordinate data are previously input from outside and stored.

  The position block identification processing unit 12 is supplied with the coordinates X and Y of the pixel G (X, Y) from the horizontal / vertical counter 11 and is also supplied with the data stored in the coordinate data storage unit 13 for correction. The required range is further divided into a plurality of position blocks.

  The position calculation processing unit 14 receives the coordinates X and Y of the pixel G (X, Y) supplied from the horizontal / vertical counter 11, the data stored in the coordinate data storage unit 13, and the position block identification processing unit 12. From the suffix n that identifies the supplied position block, it is determined at which address of which position block the pixel G (X, Y) is located, and the determination result is output as address data Xb, Yb.

  The correction data storage unit 16 is provided with a register for storing correction data Cc (Xc, Yc, Zc) at the correction center coordinates Gc.

  Based on the address data Xb, Yb from the position calculation processing unit 14 and the correction data Cc stored in the correction data storage unit 16, the three-dimensional interpolation processing unit 15 performs an arbitrary pixel G (X, Y). Three-dimensional interpolation data C (X, Y, Z) is generated by interpolating the output level of the video signal to which level Z is applied. The three-dimensional interpolation data C (X, Y, Z) is supplied to the white balance adjustment unit 3 and the gamma correction unit 4.

  The detailed configuration and operation of the white balance adjustment unit 3, the gamma correction unit 4, and the three-dimensional correction unit 5 are described in Japanese Patent Application Laid-Open No. 11-113019 related to the application of the present applicant. The screen of the liquid crystal element 25 is divided into a plurality of areas, and uniformity correction (white balance adjustment) according to the VT curve characteristics of each area and the level of the video signal is applied to the video signal applied to the liquid crystal element 25. Or gamma correction).

  However, here, as shown in FIG. 6, the correction data storage unit 16 of the three-dimensional correction unit 5 uses correction data Cc used when the variable aperture 1 is opened as a register for storing the correction data Cc. Are provided, and a register 17 for storing correction data Cc used when the variable aperture 1 is closed is provided.

  When adjusting the liquid crystal projector at the factory, the unevenness of color and brightness of the projected image with the variable aperture 1 opened and the unevenness of color and brightness of the projected image with the variable aperture 1 closed are measured. Then, the screen of the liquid crystal element 25 corresponding to the angular distribution of the incident light to the liquid crystal element 25 with the variable aperture 1 opened is compensated for color unevenness and luminance unevenness with the variable aperture 1 opened. The correction data Cc (according to the VT curve characteristics of each area) is stored in the register 17 and also compensates for color irregularities and luminance irregularities when the variable aperture 1 is closed (a state where the variable aperture 1 is closed). The correction data Cc (according to the VT curve characteristic of each area of the screen of the liquid crystal element 25) corresponding to the angle distribution of the incident light on the liquid crystal element 25 in the above is stored in the register 18.

  The CPU 6 controls the three-dimensional correction unit 5 when the operation of opening the variable aperture 1 with the above-described aperture adjustment button, and corrects the correction in the register 17 among the registers 17 and 18 of the correction data storage unit 16. When the data Cc is referred to the three-dimensional interpolation processing unit 15 and on the other hand, an operation of closing the variable aperture 1 with the aperture adjustment button is performed, the three-dimensional correction unit 5 is controlled to correct the correction data storage unit 16. The three-dimensional interpolation processing unit 15 is referred to the correction data Cc in the register 18 among the registers 17 and 18.

Next, the operation of this liquid crystal projector will be described.
When using this liquid crystal projector in an environment with external light, the user performs an operation of opening the variable aperture 1 with the above-described aperture adjustment button. Then, the area of the opening of the variable diaphragm 1 is maximized based on the control of the CPU 6, thereby reducing the amount of light shielded by the variable diaphragm 1, so that the white color becomes bright and high brightness image expression is performed.

  On the other hand, when using this liquid crystal projector in an environment where there is no external light, the user performs an operation of closing the variable aperture 1 with the above-described aperture adjustment button. Then, the area of the opening of the variable diaphragm 1 is reduced based on the control of the CPU 6, and the light shielding amount of the variable diaphragm 1 is increased, so that white is suppressed and the contrast is increased. In this way, both luminance and contrast can be achieved.

  When the variable aperture 1 is opened, based on the control of the CPU 6, the three-dimensional correction unit 5 receives correction data Cc in the register 17 of the correction data storage unit 16 (projection with the variable aperture 1 opened). Three-dimensional interpolation data C (X, Y, Z) created based on correction data for compensating color unevenness and luminance unevenness of the image is supplied to the white balance adjustment unit 3 and gamma correction unit 4. As a result, the white balance adjustment unit 3 and the gamma correction unit 4 perform a uniform operation that compensates for color unevenness and luminance unevenness of the projected image with the variable aperture 1 opened with respect to the video signal applied to the liquid crystal element 25. Mitty correction (white balance adjustment and gamma correction) is performed.

  On the other hand, when the variable aperture 1 is closed, based on the control of the CPU 6, the three-dimensional correction unit 5 receives correction data Cc in the register 18 of the correction data storage unit 16 (projection with the variable aperture 1 closed). Three-dimensional interpolation data C (X, Y, Z) created based on correction data for compensating color unevenness and luminance unevenness of the image is supplied to the white balance adjustment unit 3 and gamma correction unit 4. As a result, the white balance adjustment unit 3 and the gamma correction unit 4 perform a uniform operation that compensates for color unevenness and luminance unevenness of the projected image with the variable aperture 1 closed with respect to the video signal applied to the liquid crystal element 25. Mitty correction is performed.

  As described above, in this liquid crystal projector, opening / closing of the variable aperture 1 is performed by performing different corrections on the same level of video signals in the same part of the screen of the liquid crystal element 25 according to the open / close state of the variable aperture 1. Even if the angular distribution of light emitted from the liquid crystal element 25 and reaching the screen changes depending on the state, appropriate uniformity correction can be performed.

  Further, in the correction data storage unit 16 of the three-dimensional correction unit 5, registers 17 and 18 that store correction data Cc corresponding to the characteristics of each area of the screen of the liquid crystal element 25 in accordance with the open / close state of the variable aperture 1. Therefore, appropriate uniformity correction according to the open / close state of the variable aperture 1 is performed more quickly than when correction data Cc according to the current open / close state of the variable aperture 1 is obtained by calculation. be able to.

  Next, FIG. 7 shows an example of the configuration of a liquid crystal projector to which the present invention is applied, and the same reference numerals are given to portions common to those in FIGS. This liquid crystal projector has no projection, but has a projection lens 28 composed of a zoom lens having an F number of 1.85 to 2.2.

  Although not shown, the operation panel and remote controller of the main body of the liquid crystal projector are provided with a zoom adjustment button for performing an operation of adjusting the zoom position of the projection lens 28. The CPU 6 controls the zoom position of the projection lens 28 based on the operation of the zoom adjustment button.

  7 shows a state where the zoom position of the projection lens 28 is on the wide angle side (state where the F number is 1.85), and FIG. 8 shows a state where the zoom position of the projection lens 28 is on the tele side (F number). (A state in which the white balance adjustment unit 3, the gamma correction unit 4, the three-dimensional correction unit 5, and the CPU 6 are omitted in FIG. 8). As shown in these drawings, the angular distribution of the light emitted from the liquid crystal element 25 and reaching the screen changes according to the change in the zoom position of the projection lens 28.

  At the time of adjusting the liquid crystal projector at the factory, the color unevenness and luminance unevenness of the projection image when the zoom position of the projection lens 28 is on the wide angle side (the state shown in FIG. 7), and the zoom position of the projection lens 28 are on the telephoto side. The projection image 28 in a certain state (the state shown in FIG. 8) is measured for color unevenness and luminance unevenness (projection to compensate for color unevenness and luminance unevenness when the zoom position of the projection lens 28 is on the wide-angle side). According to the VT curve characteristic of each area of the screen of the liquid crystal element 25 corresponding to the incident angle distribution when the light projected from the projection lens 28 enters the liquid crystal element 25 in a state where the zoom position of the lens 28 is on the wide angle side. The correction data Cc is stored in the register 17 (FIG. 6) of the correction data storage unit 16 of the three-dimensional correction unit 5, and color unevenness and luminance unevenness when the zoom position of the projection lens 28 is on the telephoto side. Each area of the screen of the liquid crystal element 25 for compensation (corresponding to the incident angle distribution when the light projected from the projection lens 28 enters the liquid crystal element 25 with the zoom position of the projection lens 28 on the telephoto side) Correction data Cc (according to the VT curve characteristics) is stored in the register 18.

  The CPU 6 controls the three-dimensional correction unit 5 and controls the registers 17 and 18 of the correction data storage unit 16 when an operation for setting the zoom position of the projection lens 28 to the wide angle side is performed with the zoom adjustment button described above. If the correction data Cc in the register 17 is referred to the three-dimensional interpolation processing unit 15 and the zoom adjustment button is operated to set the zoom position of the projection lens 28 to the tele side, the three-dimensional correction is performed. The unit 5 is controlled to cause the three-dimensional interpolation processing unit 15 to refer to the correction data Cc in the register 18 among the registers 17 and 18 of the correction data storage unit 16.

  The rest of the configuration of this liquid crystal projector is the same as that of the liquid crystal projector of FIG.

Next, the operation of this liquid crystal projector will be described.
When the user operates the zoom adjustment button described above, the zoom position of the projection lens 28 is adjusted under the control of the CPU 6.

  When the zoom position of the projection lens 28 is adjusted to the wide angle side, based on the control of the CPU 6, the three-dimensional correction unit 5 receives correction data Cc in the register 17 of the correction data storage unit 16 (of the projection lens 28). Three-dimensional interpolation data C (X, Y, Z) created based on correction data for compensating color unevenness and brightness unevenness in a state where the zoom position is on the wide angle side is white balance adjustment unit 3 and gamma correction unit. 4 is supplied. Thereby, the white balance adjustment unit 3 and the gamma correction unit 4 compensate for the color unevenness and luminance unevenness in the state where the zoom position of the projection lens 28 is on the wide angle side with respect to the video signal applied to the liquid crystal element 25. Uniformity correction (white balance adjustment and gamma correction) is performed.

  On the other hand, when the zoom position of the projection lens 28 is adjusted to the tele side, based on the control of the CPU 6, the three-dimensional correction unit 5 receives the correction data Cc in the register 18 of the correction data storage unit 16 (of the projection lens 28). The three-dimensional interpolation data C (X, Y, Z) created on the basis of color unevenness and luminance unevenness in the state where the zoom position is on the telephoto side) is the white balance adjustment unit 3 and gamma correction unit. 4 is supplied. As a result, the white balance adjustment unit 3 and the gamma correction unit 4 compensate for color unevenness and luminance unevenness in a state where the zoom position of the projection lens 28 is on the tele side with respect to the video signal applied to the liquid crystal element 25. Uniformity correction is performed.

  As described above, in this liquid crystal projector, the zoom of the projection lens 28 is corrected by performing different corrections on the same level of the video signal in the same part of the screen of the liquid crystal element 25 according to the zoom position of the projection lens 28. Even if the angular distribution of the light emitted from the liquid crystal element 25 and reaching the screen changes depending on the position, appropriate uniformity correction can be performed.

  Also, the correction data storage unit 16 of the three-dimensional correction unit 5 stores two types of registers 17 and 18 that store correction data Cc corresponding to the characteristics of each area of the screen of the liquid crystal element 25 according to the zoom position of the projection lens 28. Therefore, appropriate uniformity correction corresponding to the zoom position of the projection lens 28 is performed more quickly than when correction data Cc corresponding to the current zoom position of the projection lens 28 is obtained by calculation. be able to.

  Further, since the CPU 6 determines the current zoom position of the projection lens 28 and correction is performed according to the F number at the current zoom position of the projection lens 28 based on the determination result, the change in the zoom position of the projection lens 28 is performed. Appropriate uniformity correction according to the can be automatically performed.

  Next, FIG. 9 shows an example of the configuration of another liquid crystal projector to which the present invention is applied, and the same reference numerals are given to portions common to those in FIGS. This liquid crystal projector is not provided with a variable aperture, but the projection lens can be exchanged between two types of projection lenses: an F-number 1.85 projection lens and an F-number 2.2 projection lens. . The angular distribution of light emitted from the liquid crystal element 25 and reaching the screen changes according to the F number of the projection lens to be mounted.

  As the projection lens mounted on the liquid crystal projector, a projector provided with an F-number transmission unit 29a as shown as the projection lens 29 in the figure is used. The F number transmission unit 29a is for informing the CPU 6 of the liquid crystal projector of its own F number (1.85 or 2.2), and attaches the projection lens 29 to the liquid crystal projector. Thus, data indicating the F number is stored in a memory (for example, ROM) connected to the CPU 6. The CPU 6 determines the F number of the mounted projection lens 29 by reading data from this memory. (As another example, the F-number transmission unit 29a is composed of protrusions attached to different positions of the projection lens 29 depending on whether the F-number is 1.85 or 2.2, and is projected onto the liquid crystal projector. A means for detecting the position of the projection when the lens 29 is mounted may be provided, and the CPU 6 may determine the F number of the projection lens 29 based on the detection result.

  When adjusting the liquid crystal projector at the factory, the projection image with the projection lens with the F number of 1.85 and the projection image with the projection lens with the F number of 2.2 and the projection image with the F number 2.2. In order to compensate for color unevenness and luminance unevenness in a state where an F number 1.85 projection lens is mounted (with an F number 1.85 projection lens mounted) The correction data Cc (according to the VT curve characteristics of each area of the screen of the liquid crystal element 25) corresponding to the incident angle distribution when the light projected from the projection lens enters the liquid crystal element 25 is It is stored in the register 17 (FIG. 6) of the correction data storage unit 16 and compensates for color unevenness and luminance unevenness in a state where a projection lens of F number 2.2 is attached (F number 2.2). Correction data Cc corresponding to the VT curve characteristics of each area of the screen of the liquid crystal element 25 corresponding to the incident angle distribution when the light projected from the projection lens is incident on the liquid crystal element 25 with the projection lens mounted. Is stored in the register 18.

  When the F number of the projection lens 29 determined using the F number transmission unit 29a of the mounted projection lens 29 is 1.85, the CPU 6 controls the three-dimensional correction unit 5 to correct the correction data. Of the registers 17 and 18 of the storage unit 16, the correction data Cc in the register 17 is referred to the three-dimensional interpolation processing unit 15, and on the other hand, the determination is made using the F number transmission unit 29a of the mounted projection lens 29. When the F number of the projection lens 29 is 2.2, the three-dimensional correction unit 5 is controlled so that the correction data Cc in the register 18 out of the registers 17 and 18 in the correction data storage unit 16 is 3 The dimension interpolation processing unit 15 is referred to.

  The rest of the configuration of this liquid crystal projector is the same as that of the liquid crystal projector of FIG.

Next, the operation of this liquid crystal projector will be described.
When the user mounts the projection lens 29 having an F number of 1.85 on the liquid crystal projector, the F number of the mounted projection lens 29 is 1.85 using the F number transmission unit 29a. Is determined by the CPU 6. Then, based on the control of the CPU 6, the three-dimensional correction unit 5 performs correction data Cc in the register 17 of the correction data storage unit 16 (color unevenness and luminance unevenness in a state where a projection lens having an F number of 1.85 is attached). The three-dimensional interpolation data C (X, Y, Z) created based on the correction data for compensation) is supplied to the white balance adjustment unit 3 and gamma correction unit 4. As a result, the white balance adjustment unit 3 and the gamma correction unit 4 compensate for the color unevenness and luminance unevenness with the projection lens having the F number of 1.85 attached to the video signal applied to the liquid crystal element 25. Uniform uniformity correction (white balance adjustment and gamma correction).

  On the other hand, when the user mounts the projection lens 29 having an F number of 2.2 on the liquid crystal projector, the F number of the mounted projection lens 29 is 2.2 using the F number transmission unit 29a. It is determined by the CPU 6 that there is. Then, based on the control of the CPU 6, the three-dimensional correction unit 5 performs correction data Cc in the register 17 of the correction data storage unit 16 (color unevenness and luminance unevenness in a state where a projection lens of F number 2.2 is attached). The three-dimensional interpolation data C (X, Y, Z) created based on the correction data for compensation) is supplied to the white balance adjustment unit 3 and gamma correction unit 4. As a result, the white balance adjustment unit 3 and the gamma correction unit 4 compensate for the color unevenness and luminance unevenness in the state where the projection lens of F number 2.2 is attached to the video signal applied to the liquid crystal element 25. Uniformity correction (white balance adjustment and gamma correction) is performed.

  Thus, in this liquid crystal projector, the same level video signals in the same part of the screen of the liquid crystal element 25 are mounted by performing different corrections according to the F number of the mounted projection lens. Even if the angular distribution of the light emitted from the liquid crystal element 25 and reaching the screen is changed by the F number of the projection lens, appropriate uniformity correction can be performed.

  The correction data storage unit 16 of the three-dimensional correction unit 5 stores two types of correction data Cc corresponding to the characteristics of each area of the screen of the liquid crystal element 25 according to the F number of the exchangeable projection lens. 17 and 18, an appropriate uniform according to the F number of the mounted projection lens is obtained rather than the case where correction data Cc corresponding to the zoom position of the currently mounted projection lens is obtained by calculation. Mitty correction can be performed quickly.

  Further, the CPU 6 discriminates the F number of the currently mounted projection lens, and correction is performed according to the F number of the currently mounted projection lens based on the discrimination result. Appropriate uniformity correction according to the number can be automatically performed.

  Next, FIG. 10 shows an example of a change in the configuration of the liquid crystal projector of FIG. 9, and the same reference numerals are given to portions common to FIGS. 1, 5, 6, and 9. As a projection lens to be mounted on this liquid crystal projector, an F number 2.2 projection lens having a difference data storage unit 30a as shown as a projection lens 30 in the figure is used (F number 1.85). The normal projection lens which does not have such a difference data storage unit 30a is used for the projection lens).

  The difference data storage unit 30a is stored in a memory (for example, ROM) connected to the CPU 6 by attaching the projection lens 30 to the liquid crystal projector, in the example of FIG. 9, the register 17 of the correction data storage unit 16 of the three-dimensional correction unit 5 ( The correction data storage unit 16 of the three-dimensional correction unit 5 with respect to the correction data Cc stored in FIG. 6) (correction data for compensating for color unevenness and luminance unevenness when the projection lens having an F number of 1.85 is attached). It is configured by storing difference data of correction data Cc (correction data for compensating color unevenness and luminance unevenness in a state where a projection lens of F number 2.2 is mounted) stored in the register 18 (FIG. 6). Has been.

  Although illustration is omitted, in this example, the correction data storage unit 16 of the three-dimensional correction unit 5 has correction data for compensating for color unevenness and luminance unevenness in a state where a projection lens having an F number of 1.85 is attached. Only a register storing Cc (a register corresponding to the register 17 in FIG. 6) is provided, and correction data Cc for compensating for color unevenness and brightness unevenness when a projection lens of F number 2.2 is mounted. Is not provided (register corresponding to the register 18 in FIG. 6).

  When the difference data storage unit 30a does not exist in the mounted projection lens (when the F number of the mounted projection lens is 1.85), the CPU 6 corrects the correction data Cc in the register of the correction data storage unit 16. Is referred to by the three-dimensional interpolation processing unit 15, and the three-dimensional correction unit 5 is made to create the three-dimensional interpolation data C (X, Y, Z) based on the correction data Cc.

  On the other hand, when the difference data storage unit 30a exists in the mounted projection lens (when the F number of the mounted projection lens is 2.2), the CPU 6 reads the difference data from the difference data storage unit 30a. The difference data and the correction data Cc in the register of the correction data storage unit 16 are referred to the three-dimensional interpolation processing unit 15, and the three-dimensional correction unit 5 receives 3 data based on the data obtained by subtracting the difference data from the correction data Cc. Dimensional interpolation data C (X, Y, Z) is created.

  The other configuration of the liquid crystal projector is the same as that of the example of FIG.

  In this example, it is sufficient to store only the correction data Cc corresponding to the F number (F number 1.85) of the projection lens serving as a reference in the correction data storage unit 16 of the three-dimensional correction unit 5. Thus, in addition to obtaining the same operation effect as the example of FIG. 9, even when there are many types of projection lenses that can be exchanged (here, a projection lens with an F number of 1.85 and an F number of 2.2). The projection lens can be replaced without storing a large amount of correction data in the correction data storage unit 16 of the three-dimensional correction unit 5 of the liquid crystal projector body. It is possible to perform appropriate uniformity correction according to.

  Further, the difference data storage unit 30a of the projection lens can store not only the F number but also difference data including optical characteristics unique to the projection lens, for example, correction of the light amount distribution by the angle of view of the projection lens. Accordingly, the liquid crystal projector main body can perform appropriate uniformity correction corresponding to the optical characteristics of the individual projection lenses to be replaced.

  In the above example, the difference data is stored in the storage unit of the projection lens to be exchanged. However, the correction data corresponding to the individual projection lens is stored by the storage unit of the projection lens, and the correction data is stored. Therefore, the present invention can be widely applied to various configurations in which the liquid crystal projector main body performs appropriate uniformity correction according to the replacement of the projection lens.

  In each of the above examples, a liquid crystal projector provided with a variable aperture, a liquid crystal projector having a projection lens composed of a zoom lens, and a liquid crystal projector in which the projection lens can be exchanged are shown separately. However, the present invention is not limited to this, and the present invention is also applied to a liquid crystal projector having a variable aperture and a projection lens composed of a zoom lens, and a liquid crystal projector having a variable aperture and a replaceable projection lens (variable aperture). Appropriate uniformity correction is performed according to the combination of the current open / close state and the current zoom position, or appropriate according to the combination of the current open / close state of the variable aperture and the F number of the currently installed projection lens. Uniformity correction may be performed).

  In each of the above examples, the video signal applied to the liquid crystal element 25 is corrected in accordance with the two-stage open / close state of the variable aperture 1 (two-stage adjustment of the area of the opening). ing. However, as another example, the video signal applied to the liquid crystal element 25 may be corrected according to the open / closed state of the variable aperture 1 in three or more stages.

  Further, in each of the above examples, the present invention is applied to the liquid crystal projector, but the present invention may be applied to other projection display devices. For example, when a variable aperture is installed in the DMD projector, it may be installed in the projection lens.

  In the example of FIG. 5 described above, the variable aperture 1 (mechanical shutter) is used as the light shielding means. However, as another example, a liquid crystal shutter composed of a transmissive liquid crystal element may be used as the light shielding means.

  Further, the present invention is not limited to the above examples, and it is needless to say that various other configurations can be taken without departing from the gist of the present invention.

It is a figure which shows the basic composition of a liquid-crystal projector. It is a figure which shows the basic composition of a DMD projector. It is a figure which shows the conventional liquid crystal projector which installed the aperture_diaphragm | restriction. It is a figure which shows the conventional liquid crystal projector which installed the aperture_diaphragm | restriction. It is a figure which shows the structural example of the liquid crystal projector devised in relation to this invention. It is a block diagram which shows the structural example of the three-dimensional correction | amendment part of FIG. It is a figure which shows the structural example of the liquid crystal projector to which this invention is applied. It is a figure which shows the change of the zoom position of the liquid crystal projector of FIG. It is a figure which shows the structural example of another liquid crystal projector to which this invention is applied. It is a figure which shows the example of a change of the liquid crystal projector of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Variable aperture, 2 Variable aperture drive part, 3 White balance adjustment part, 4 Gamma correction part, 5 Three-dimensional correction part, 6 CPU, 21 Light source, 22 Reflecting mirror, 23 Illumination optical system, 25 Liquid crystal element, 27 Projection lens, 28 projection lens, 29 projection lens, 30 projection lens

Claims (4)

A light source;
A spatial light modulation element that modulates and emits incident light according to the applied video signal;
An illumination optical system for condensing light from the light source and illuminating the spatial light modulator;
With
The projection lens that projects the light emitted from the spatial light modulation element can be exchanged between a plurality of types of projection lenses having different F-numbers.
The screen of the spatial light modulation element is divided into a plurality of regions, and for the video signal applied to the spatial light modulation element, for each of the regions, according to the F number of the currently installed projection lens, A video signal correction unit that performs correction so as to compensate for a light output from the spatial light modulation element that varies depending on a position in the screen, and an F number of a projection lens serving as a reference among the plurality of types of projection lenses Difference correction data with respect to the reference correction data for performing individual correction corresponding to the projection lens on the currently mounted projection lens. Is stored based on the reference correction data stored in the reference correction data storage means, When the individual correction data storage means is present in the installed projection lens, the reference correction data stored in the reference correction data storage means and the difference stored in the individual correction data storage means Video signal correction means for performing correction based on the data
Projection display device. The video signal correction means performs the correction according to the characteristics of the output level of light in the region with respect to the applied level of the video signal and the F number of the currently mounted projection lens for each of the regions. Do
The projection display device according to claim 1. The reference correction data storage means includes, as the reference correction data, correction data (Xc, Yc, Yc) for a video signal of level Zc at the coordinates (Xc, Yc) of the center point to be corrected in the screen of the spatial light modulator. Zc)
The video signal correcting means outputs the output level of the video signal of level Z at coordinates (X, Y) in the screen of the spatial light modulator as data for compensating the light output from the spatial light modulator. 3D interpolation data creation means for creating 3D interpolation data (X, Y, Z) obtained by interpolating
The projection type display device according to claim 2. The three-dimensional interpolation data creation means includes:
Address data Xb, Yb indicating which address of which area of the plurality of areas of the screen of the spatial light modulation element is located at the coordinates (X, Y) is created, and the currently mounted When the individual correction data storage means does not exist in the projection lens, the three-dimensional interpolation data (X) is based on the reference correction data and the address data Xb, Yb stored in the reference correction data storage means. , Y, Z) and when the individual correction data storage means is present in the currently mounted projection lens, the reference correction data stored in the reference correction data storage means and the individual correction data storage means The three-dimensional interpolation data (X, Y, Z) is created based on the difference data and the address data Xb, Yb stored in the correction data storage means.
The projection display device according to claim 3.

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