JP2009194420A - Pixel shift measuring instrument, image display device, and pixel shift measurement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pixel shift measuring instrument which determines the displacement of a display pixel using a simple technique, and to provide an image display device and a pixel shift measurement method. <P>SOLUTION: A pixel shift measuring instrument 200, which measures the displacement of a display pixel, comprises a measuring section for acquiring a measured value, corresponding to the displacement of a display pixel of each pattern image which constitutes a plurality of pattern images, whose displacements of pixels are different from each other, and a section for determining the pixel shift, corresponding to a selected pattern image by selecting one from among the plurality of pattern images, based on the measurement value that corresponds to each pattern image. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pixel shift measuring device, an image display device, and a pixel shift measuring method.

  As an image display device typified by a projector (image projection device in a broad sense), an image that displays a multi-tone image by aligning the positions of display pixels corresponding to sub-pixels of a plurality of color components that constitute one pixel There is a display device. In this type of image display apparatus, the position of the display pixel corresponding to the sub-pixel of each color component may be shifted due to errors in the optical system (for example, the influence of chromatic aberration), adjustment accuracy of the constituent members, and the like. A shift in the position of the display pixel causes a decrease in resolution and generation of a false color at the edge portion of the display pixel, leading to a deterioration in the image quality of the display image. With the recent increase in resolution, the amount of shift in the position of the display pixel corresponding to the sub-pixel tends to be relatively large.

  In order to suppress the deterioration of image quality due to such display pixel position shift, a projector that corrects the pixel shift is known. In this projector, the user observes the display image of the projector and adjusts the position of the display pixel by using a pixel position adjustment function mounted on the projector.

  When this type of pixel position adjustment function is used, it is necessary to be able to accurately measure the amount of pixel shift. However, there are many cases where the shape of the display pixel is not rectangular due to the focus or flare of the projector, and it is difficult to accurately measure the position of the display pixel when trying to simply measure the position of the display pixel. Therefore, even if the pixel shift amount is obtained using the measurement result of such a measuring apparatus and the position of the display pixel corresponding to the pixel shift amount is adjusted, generation of false color at the edge portion of the display pixel is suppressed. I can't.

  For example, Patent Document 1 discloses a technique for measuring such a pixel shift with high accuracy. In Patent Document 1, an image having a mountain wave shape lightness distribution in which the lightness is highest at the center and decreases concentrically is projected, and this image is photographed with a camera to obtain the center position of the mountain waveform from the histogram. Technology is disclosed.

JP 2001-356005 A

  However, the technique disclosed in Patent Document 1 requires a complicated measurement process, and even if the displacement amount of the display pixel can be accurately measured using the technique disclosed in Patent Document 1, It is still necessary to perform precise position adjustment corresponding to the measured pixel shift amount.

  The present invention has been made in view of the technical problems as described above, and one of the purposes thereof is a pixel deviation measuring apparatus, an image display apparatus, and a pixel for obtaining a positional deviation of display pixels by a simple method. It is to provide a deviation measuring method.

  In order to solve the above problems, the present invention is a pixel shift measuring apparatus for measuring a shift amount of a display pixel, and includes a display pixel of each pattern image constituting a plurality of pattern images having different pixel shift amounts. A measurement unit that acquires a measurement value corresponding to a deviation amount, and a pixel that selects one of the plurality of pattern images based on the measurement value corresponding to each pattern image and obtains a deviation amount corresponding to the selected pattern image The present invention relates to a pixel shift measuring device including a shift amount determining unit.

  According to the present invention, the measurement unit measures each pattern image constituting a plurality of pattern images having different pixel shift amounts, and selects one pattern image based on the measurement value, thereby selecting the selected pattern image. Since it is possible to determine the amount of deviation corresponding to the above, it is possible to obtain the amount of pixel deviation by a simple method.

  In the pixel shift measuring apparatus according to the present invention, the measurement unit acquires a measurement value that increases as the false color increases, or a measurement value that decreases as the false color increases, and the pixel shift The quantity determination unit can select a pattern image in which the measurement value is the maximum value or the minimum value.

  According to the present invention, if the measurement value can be acquired in the measurement unit, the pixel shift amount can be obtained without applying a processing load in the pixel shift amount determination unit.

  In the pixel shift measuring apparatus according to the present invention, the measurement unit acquires a measurement value corresponding to a color component of each pattern image, and the pixel shift amount determination unit includes the entire screen of the plurality of pattern images. It is possible to select a pattern image that minimizes the average value of the measured values.

  According to the present invention, the measurement value corresponding to the color component of the pattern image is acquired, and the pattern image is selected based on the average value of the measurement values of the entire screen. With the configuration, the amount of pixel shift can be obtained.

  The pixel shift measuring apparatus according to the present invention may further include a pattern image storage unit that stores the plurality of pattern images having different pixel shift amounts in the horizontal direction or the vertical direction of the pattern image.

  According to the present invention, a plurality of pattern images having different pixel shift amounts in the horizontal direction or the vertical direction of the pattern image are prepared, and the pattern image is selected from the plurality of pattern images. With this technique, the amount of pixel shift in the horizontal or vertical direction of the image can be obtained.

  Further, in the pixel shift measuring apparatus according to the present invention, the plurality of pattern images are generated so that pixel shift amounts are different from each other with respect to a binary image having a line width of one pixel in a grid pattern. It may be an image.

  According to the present invention, a plurality of pattern images are generated on the basis of a binary image having a straight line having a line width of one pixel in a grid pattern, so that a simple method can be used in the horizontal or vertical direction of the image. The amount of pixel shift can be determined with higher accuracy.

  In the pixel shift measuring apparatus according to the present invention, the plurality of pattern images are provided for each of the remaining color components excluding the reference color component among the plurality of color components constituting one pixel, and each color of the remaining color components Pattern images with different amounts of component sub-pixel displacement may be used.

  According to the present invention, since the pattern image is provided for each color component excluding the reference color component, the shift amount of the display pixel corresponding to the sub-pixel of each color component is accurately obtained for each color component based on the reference color component. Will be able to.

  In addition, the present invention includes any one of the above-described pixel shift measuring devices and an image display unit that displays each pattern image and displays an image based on the shift amount, and the image display unit includes the shift unit. The present invention relates to an image display device that displays an image based on an image signal corrected corresponding to the amount.

  According to the present invention, since the pixel shift amount obtained by the pixel shift measuring device can be accurately reflected in the display image, the measured pixel shift amount cannot be accurately reflected and a false color can be seen. Can be avoided reliably.

  Further, the present invention is a pixel shift measuring method for measuring a shift amount of a display pixel, and is a measurement corresponding to a shift amount of a display pixel of each pattern image constituting a plurality of pattern images having different pixel shift amounts. A measurement step of acquiring a value, and a pixel shift amount determination step of selecting one of the plurality of pattern images based on the measurement value corresponding to each pattern image and obtaining a shift amount corresponding to the selected pattern image. This relates to a pixel shift measurement method including the above.

  According to the present invention, the measurement unit measures each pattern image constituting a plurality of pattern images having different pixel shift amounts, and selects one pattern image based on the measurement value, thereby selecting the selected pattern image. Therefore, it is possible to provide a pixel shift measurement method that can determine the pixel shift amount with a simple method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

  In the following embodiments, the pixel shift measuring device according to the present invention will be described as being included in an image display device, but the present invention is not limited to this. The projector will be described as an example of the image display device according to the present invention. However, the present invention is not limited to this, and various image display devices that are accompanied by generation of false colors due to the displacement of the display pixel position. On the other hand, it goes without saying that the present invention can be applied.

1. Image Display Device FIG. 1 is a block diagram showing a configuration example of an image display device to which the pixel shift measuring device according to this embodiment is applied.
The image display device 10 includes an image display unit 100 and a pixel shift measuring device 200. The image display unit 100 includes a light source (not shown), modulates light from the light source according to an image signal, and projects the light onto the screen SCR using the modulated light. At this time, the image display unit 100 displays a multi-tone image by aligning the positions of display pixels corresponding to the sub-pixels of a plurality of color components constituting one pixel on the screen SCR. In this case, due to an error of the optical system included in the image display unit 100, the pixel position of the display pixel corresponding to the sub-pixel of the screen SCR does not match, and a false color is generated at the edge portion of the display pixel. There is. Here, the false color means a color of an image that is not originally intended (a color that does not exist in an image to be displayed).

  Therefore, in the present embodiment, prior to the projection of the content image on the image display unit 100, the pixel shift measuring device 200 measures the pixel shift amount (shift amount) of the display pixels of the pattern image projected by the image display unit 100. To do. The pattern image is generated corresponding to the pixel shift amount. The image display unit 100 sequentially displays pattern images having different pixel shift amounts, and the pixel shift measuring apparatus 200 acquires a measurement value of each pattern image. In this way, by selecting a pattern image corresponding to a desired measurement value, the pixel shift amount of the pattern image can be determined.

  That is, the image display unit 100 receives the image signal of the pattern image for measuring the pixel shift amount and the image signal of the content image from the pixel shift measuring apparatus 200. The image display unit 100 first projects a plurality of pattern images on the screen SCR in order based on the image signal of the pattern image. The pixel shift measuring apparatus 200 acquires a measurement value corresponding to the pixel shift amount of the display pixel of the projection image (display image) for each pattern image. Thereafter, the image display unit 100 corrects the image signal (input image signal) of the content image based on the pixel shift amount corresponding to the measurement value obtained by the pixel shift measuring apparatus 200, and projects the content image on the screen SCR.

  At this time, a pattern image corresponding to a desired measurement value is selected from the measurement values acquired by the pixel shift measuring apparatus 200. Then, a pixel shift amount corresponding to the selected pattern image is determined. For example, a measurement value in which the false color is most inconspicuous can be determined as the desired measurement value. By doing so, the pixel shift amount can be determined with a very simple configuration.

  The pattern image is generated by the same processing as the image signal correction processing of the content image by the image display unit 100. Therefore, since the pixel shift amount measured by the pixel shift measuring apparatus 200 can be used as it is for the correction process of the image signal of the content image, the measured pixel shift amount does not match the correction process corresponding to the pixel shift amount. In addition, it is possible to reliably avoid a situation in which the occurrence of false colors cannot be suppressed. In addition, since it is only necessary to perform image signal correction processing corresponding to the pixel shift amount, the pixel shift amount can be accurately reflected without having a precise pixel position adjustment function. Generation of false colors can be suppressed.

2. Pixel Deviation Measurement Device As shown in FIG. 1, the pixel deviation measurement device 200 in this embodiment includes a color measurement unit (measurement unit) 210 and a pixel deviation amount determination unit 220. The color measurement unit 210 acquires a measurement value corresponding to the shift amount of the display pixel of each pattern image constituting a plurality of pattern images having different pixel shift amounts. Such a function of the color measuring unit 210 is realized by, for example, a colorimeter or a colorimeter. The pixel shift amount determination unit 220 selects one of a plurality of pattern images based on the measurement value corresponding to each pattern image, and obtains a shift amount corresponding to the selected pattern image. Accordingly, the pixel shift amount can be obtained with a simple configuration and processing, and the pixel shift amount can be obtained according to the accuracy of the prepared pattern image even if the color measurement unit 210 does not have a high resolution.

  More specifically, the color measurement unit 210 acquires a measurement value that increases as the false color increases, or a measurement value that decreases as the false color increases. You may select the pattern image from which a measured value becomes the maximum value or the minimum value. For example, the color measurement unit 210 acquires measurement values corresponding to the color components of each pattern image, and the pixel shift amount determination unit 220 selects a pattern image that minimizes the average value of the color components of the entire pattern image screen. can do. Accordingly, if the measurement value can be acquired by the color measurement unit 210, the pixel shift amount can be obtained without applying a processing load in the pixel shift amount determination unit 220.

  Further, the pixel shift measuring apparatus 200 can include a pattern image generation unit 230 and a pattern image storage unit 240. The pattern image generation unit 230 generates a plurality of pattern images having different pixel shift amounts in the horizontal direction or the vertical direction of the image with respect to a given original pattern image. The pattern image storage unit 240 stores a plurality of pattern images generated by the pattern image generation unit 230 and having different pixel shift amounts in the horizontal direction or the vertical direction of the pattern image.

  FIG. 2 is an explanatory diagram of a pattern image in the present embodiment. In FIG. 2, the horizontal axis represents the pixel shift amount in the horizontal direction of the image, and the vertical axis represents the pixel shift amount in the vertical direction of the image.

  In FIG. 2, a pattern image having a horizontal pixel shift amount of “0.0” and a vertical pixel shift amount of “0.0” is defined as an original pattern image PAT0. Here, the original pattern image PAT0 is a binary image having straight lines with a line width of one pixel in a grid pattern. In FIG. 2, a “white” straight line having a line width of one pixel is provided in a grid pattern on a “black” background.

  The pattern image generation unit 230 generates a pattern image in which the pixel position is shifted in at least one of the horizontal direction and the vertical direction of the image with respect to the original pattern image PAT0. If the given first horizontal direction is a negative direction and the direction opposite to the first horizontal direction is a positive direction with reference to the position of each pixel of the original pattern image PAT0, the pattern image generation unit 230 causes the original pattern image PAT0 to On the other hand, a pattern image in which the pixel position is shifted in the horizontal direction in the range of “−1.0” pixels to “+1.0” pixels, for example, in increments of “0.1” pixels is generated. When the given first vertical direction is a negative direction and the direction opposite to the first vertical direction is a positive direction with reference to the position of each pixel of the original pattern image PAT0, the pattern image generating unit 230 For the image PAT0, a pattern image in which the pixel position is shifted in the vertical direction in the range of “−1.0” pixels to “+1.0” pixels, for example, in increments of “0.1” pixels is generated. In this way, the pattern image generation unit 230 can generate 21 × 21 types of pattern images having different pixel shift amounts in the horizontal direction or the vertical direction of the original pattern image PAT0.

  FIG. 3 is an explanatory diagram of a unit of display pixel shift amount in the present embodiment. FIG. 3 shows the unit of the amount of deviation of the pattern image in the horizontal direction, but the unit of the amount of deviation of the pattern image in the vertical direction is the same.

  In FIG. 3, when the horizontal pixel number of the display image (projected image) on the screen SCR is Y and the horizontal length of the display image on the screen SCR is D, the pattern image generation unit 230 sets D / Y to D / Y. As “1.0” pixels, pattern images having different pixel shift amounts in units of D / (10 × Y) (= “0.1” pixels) in the horizontal direction are generated.

  Similarly, the pattern image generation unit 230 sets the number of pixels in the vertical direction of the display image (projected image) on the screen SCR to YV (not shown), and sets the vertical length of the display image on the screen SCR to DV (see FIG. If not shown, the pattern image generation unit 230 sets DV / YV to “1.0” pixels, and the pixel shift amount in increments of DV / (10 × YV) (= “0.1” pixels) in the vertical direction. Different pattern images are generated.

  As described above, in this embodiment, a pattern image in which the pixel position is shifted is generated with respect to the original pattern image PAT0 in which the edge of the straight line portion of the image is easily discriminated in the horizontal direction and the vertical direction of the image. For this reason, in the pattern image, the edge of the straight line portion of the image is not steep, and the pixel shift amount for correcting the image signal is determined so that the edge of the straight line portion is most easily discriminated when the image is displayed.

  Note that 21 × 21 types of pattern images shown in FIG. 2 are provided for each of the remaining color components excluding the reference color component among a plurality of color components constituting one pixel. If one pixel is composed of RGB sub-pixels of three color components and the reference color component is a G component, the pattern image storage unit 240 has, for example, 21 × 21 × 2 types (for R component and B component) of pattern images. Remember. In this case, the pattern image has an R component pattern image in which the pixel position is shifted in the horizontal direction or the vertical direction of the image with respect to the G component sub pixel position and the pixel position with respect to the G component sub pixel position. It consists of a B component pattern image shifted in the horizontal and vertical directions of the image. In this embodiment, correction processing is performed for each image signal of each color component using the pixel shift amount provided for each color component with reference to the pixel of the reference color component. As described above, since the pattern image is provided for each color component excluding the reference color component, it is possible to accurately obtain the shift amount of the display pixel corresponding to the sub-pixel of each color component for each color component based on the reference color component. become able to.

  FIG. 4 is an explanatory diagram of the operation principle of the pattern image generation unit 230 in the present embodiment.

FIG. 4 shows a pixel Q1 shifted by α (0 ≦ α ≦ 1) pixels in the horizontal direction and β (0 ≦ β ≦ 1) pixels in the vertical direction with respect to the pixel P1 (pixel value p1) of the original pattern image PAT0. To express. The pattern image generation unit 230 uses the pixel value q1 of the pixel Q1 as four pixels including the pixel P1 of the original pattern image PAT0 around the pixel Q1 whose pixel position is shifted (in FIG. 4, P1 (pixel value p1)). , P2 (pixel value p2), P3 (pixel value p3), and P4 (pixel value p4)) are obtained by interpolation as in the following equations.
q1 = ((1-α) × p1 + α × p2) × (1-β) + ((1-α) × p3 + α × p4) × β

  Similarly, the pattern image generation unit 230 obtains the pixel values of the pixels of the other pattern images by interpolating the pixel values of the corresponding pixels of the original pattern image PAT0.

  FIG. 5 shows an example of the original pattern image PAT0 in the present embodiment. FIG. 5 shows only three pixels arranged in the horizontal direction and three pixels arranged in the vertical direction of the image, but the original pattern image PAT0 is not limited to the number of pixels arranged in the horizontal direction or the vertical direction.

  FIG. 6 shows an example of an R component pattern image in the present embodiment. FIG. 6 shows a pattern image shifted by “0.6” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to the original pattern image PAT0.

  FIG. 7 shows an example of a G component pattern image in the present embodiment. FIG. 7 shows a pattern image shifted by “0.0” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to the original pattern image PAT0.

  FIG. 8 shows an example of a B component pattern image in the present embodiment. FIG. 8 shows a pattern image shifted by “0.0” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to the original pattern image PAT0.

  FIG. 5 shows that the R component pixel values of the three pixels arranged in the horizontal direction in the upper part of the original pattern image PAT0 are Rin00, Rin10, Rin20, the G component pixel values are Gin00, Gin10, Gin20, and the B component pixel values are Bin00, Bin10 and Bin20 are indicated. Similarly, the R component pixel values of the three pixels arranged in the middle horizontal direction of the original pattern image PAT0 are Rin01, Rin11, Rin21, the G component pixel values are Gin01, Gin11, Gin21, and the B component pixel values are Bin01, Bin11. , Bin21. Further, the pixel values of the R components of the three pixels arranged in the horizontal direction at the lower stage of the original pattern image PAT0 are Rin02, Rin12, Rin22, the pixel values of the G component are Gin02, Gin12, Gin22, and the pixel values of the B component are Bin02, Bin12, It is Bin22.

  In the case of generating a pattern image shifted by “0.6” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to such an original pattern image PAT0, as shown in FIG. 230, for each pixel, using the R component pixel value of the original pattern image PAT0 and the above-described equation, the pixel values Rout00, Rout10, Rout20 of the three pixels arranged in the upper horizontal direction are arranged in the horizontal direction of the middle. The pixel values Rout01, Rout11, Rout21 of the three pixels and the pixel values Rout02, Rout12, Rout22 of the three pixels arranged in the lower horizontal direction are obtained.

For example, in the above formula, if q1 is Rout00, p1 is Rin00, p2 is Rin10, p3 is Rin01, p4 is Rin11, α is “0.6”, and β is “0.0”, the pixel value Rout00 is It is required as follows.
Rout00 = (1-0.6) × Rin00 + 0.6 × Rin10 = Rin00 × 0.4 + Rin10 × 0.6

  Similarly, when generating a pattern image shifted by “0.0” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to the original pattern image PAT0, as shown in FIG. 230, for each pixel, using the G component pixel value of the original pattern image PAT0 and the above formula, the pixel values Gout00, Gout10, Gout20 of the three pixels arranged in the upper horizontal direction are arranged in the horizontal direction of the middle. The pixel values Gout01, Gout11, Gout21 of the three pixels and the pixel values Gout02, Gout12, Gout22 of the three pixels arranged in the horizontal direction of the lower stage are obtained.

For example, in the above formula, if q1 is Gout00, p1 is Gin00, p2 is Gin10, p3 is Gin01, p4 is Gin11, α is “0.0”, and β is “0.0”, the pixel value Gout00 is It is required as follows.
Gout00 = (1-0.0) × Gin00 + 0.0 × Gin10 = Gin00

  Further, when generating a pattern image shifted by “0.0” pixels in the horizontal direction and “0.0” pixels in the vertical direction with respect to the original pattern image PAT0, as shown in FIG. For each pixel, using the pixel value of the B component of the original pattern image PAT0 and the above formula, the pixel values Bout00, Bout10, Bout20 of the three pixels arranged in the upper horizontal direction, and 3 in the horizontal direction of the middle Pixel values Bout01, Bout11, Bout21 of the pixels, and pixel values Bout02, Bout12, Bout22 of the three pixels arranged in the horizontal direction at the lower stage are obtained.

  FIG. 9 shows another example of the R component pattern image in the present embodiment. FIG. 9 shows a pattern image shifted by “0.8” pixels in the horizontal direction and “0.8” pixels in the vertical direction with respect to the original pattern image PAT0.

  The pattern image generation unit 230 uses, for each pixel, the pixel values Rout00, Rout10, Rout20, and the middle pixel values of the three pixels arranged in the upper horizontal direction using the R component pixel value of the original pattern image PAT0 and the above-described equation. The pixel values Rout01, Rout11, Rout21 of the three pixels arranged in the horizontal direction and the pixel values Rout02, Rout12, Rout22 of the three pixels arranged in the lower horizontal direction are obtained.

For example, in the above formula, if q1 is Rout00, p1 is Rin00, p2 is Rin10, p3 is Rin01, p4 is Rin11, α is “0.8”, and β is “0.8”, the pixel value Rout00 is It is required as follows.
Rout00 = ((1-0.8) × Rin00 + 0.8 × Rin01) × (1-0.8) + ((1-0.8) × Rin10 + 0.8 × Rin11) × 0.8
= Rin00 × 0.2 × 0.2 + Rin01 × 0.8 × 0.2 + Rin10 × 0.2 × 0.8 + Rin11 × 0.8 × 0.8

  In addition, although the example which calculates | requires the pixel value of the pixel of a pattern image by the bilinear method was demonstrated in FIGS. 4-9, the pixel value of the pixel of a pattern image by well-known interpolation processing methods, such as the nearest neighbor method and the bicubic method You may ask for.

  The pixel shift measuring device 200 for obtaining the pixel shift amount based on the pattern image as described above has a central processing unit (CPU) and a memory (not shown), and the processing content shown in FIG. 10 is designated. The program is stored in memory. Then, the CPU that has read the program stored in the memory executes the processing specified by the program, thereby realizing the functions of each unit of the pixel shift measuring apparatus 200 in FIG. 1 and controlling each unit. Be able to.

  FIG. 10 shows a flowchart of a processing example of the pixel shift measuring apparatus 200 in the present embodiment.

  Prior to the processing shown in FIG. 10, the pattern image generation unit 230 generates 21 × 21 types of pattern images for each color component as described above. Then, the pixel deviation measuring apparatus 200 instructs the image display unit 100 to project a pattern image as a pattern image projection instruction step (step S10). That is, image data of one pattern image among a plurality of pattern images stored in the pattern image storage unit 240 is read, and an image signal corresponding to the image data is supplied to the image display unit 100, and the image display unit 100 is projected onto the screen SCR.

  Next, as a color measurement step (measurement step), the pixel shift measuring apparatus 200 measures the color component of the projected image on the screen SCR in the color measurement unit 210 (step S12). For example, the color measurement unit 210 measures the color component for each pixel for the entire screen of the projection image. The measurement value acquired by the color measurement unit 210 is supplied to the pixel shift amount determination unit 220. The pixel shift amount determination unit 220 manages the measurement value from the color measurement unit 210 in association with the pattern image to be measured.

  The pixel shift measuring apparatus 200 determines whether or not the color measurement has been completed for all the pattern images stored in the pattern image storage unit 240 (step S14), and if the color measurement has not been completed for all the pattern images. When it is determined (step S14: N), the process returns to step S10.

  On the other hand, when it is determined that the color measurement has been completed for all the pattern images (step S14: Y), the pixel shift amount determination unit 220 performs measurement values associated with the pattern image to be measured as the pixel shift amount determination step. One pattern image is selected based on (step S16). Subsequently, the pixel shift amount determination unit 220 obtains a pixel shift amount corresponding to the pattern image selected in step S16 (step S18), and ends the series of processes (end).

  In step S <b> 16, what pattern image is selected depends on the type of measurement value acquired by the color measurement unit 210.

  FIG. 11A and FIG. 11B are diagrams illustrating the operation of the pixel shift amount determination unit in the present embodiment. FIG. 11A shows an example of the relationship between the measured value whose value increases as the false color increases and the pixel shift amount. FIG. 11B illustrates an example of a relationship between a measured value and a pixel shift amount that decrease as the false color increases.

  As shown in FIGS. 11A and 11B, when the pixel shift amount changes, the measurement value acquired by the color measurement unit 210 or the average value of the measurement values of the entire screen changes. Therefore, in FIG. 11A, the false color can be suppressed to the minimum by obtaining the pixel shift amount that minimizes the measurement value (or the average value of the measurement values of the entire screen). In FIG. 11B, the false color can be minimized by obtaining the pixel shift amount that maximizes the measurement value (or the average value of the measurement values of the entire screen).

  Accordingly, the pixel shift amount determination unit 220 selects a pattern image in which the measurement value (or the average value of the measurement values of the entire screen) associated with each pattern image constituting the plurality of pattern images is the maximum value or the minimum value. . As a result, the amount of pixel shift corresponding to the pattern image is determined. Based on the determined amount of pixel shift, the image signal of the content image is corrected so that the false color is hardly seen. An image can be displayed on the screen.

FIG. 12 is an explanatory diagram of an operation example of the pixel shift amount determination unit 220 in the present embodiment. In FIG. 12, the vertical axis indicates the saturation Cab ^* as the average value of the color components of the entire screen, and the horizontal axis indicates the amount of pixel shift in the horizontal direction of the R component.

As described above, the color measurement unit 210 acquires the measurement value of the color component for each pixel of the display image of the screen SCR on which the pattern image is projected. For example, the saturation Cab ^* of the CIELAB (CIE 1976 L ^* a ^* b ^* ) color space is acquired as a measurement value. Here, the chroma Cab ^* are color coordinates of the CIELAB color space ^a *, as the distance between the origin of the ^{b *} color space is determined by the following equation.
Cab ^* = {(a ^* ) ² + (b ^* ) ² } ^1/2

Then, the pixel shift amount determination unit 220 calculates the minimum value of the calculated average values after calculating the average value of the Cab ^* of the entire screen for each pattern image. Then, the pixel shift amount determination unit 220 selects a pattern image that is the minimum value of the average value of Cab ^* of the entire screen. A pixel shift amount corresponding to the selected pattern image is determined as a pixel shift amount to be obtained. That is, in FIG. 12, as a result of selecting a pattern image that is the minimum value of the average value of Cab ^* of the entire screen, “−0.5” pixels (horizontal direction), which is a pixel shift amount of the pattern image, is obtained.

3. Image Display Unit In this embodiment, the image display unit 100 can correct the image signal of the content image based on the pixel shift amount obtained as described above. In this way, the obtained pixel shift amount can be accurately reflected in the display image of the content, so that it is possible to reliably avoid a situation in which a false color is seen without accurately reflecting the measured pixel shift amount. It becomes like this.

  FIG. 13 shows a block diagram of a configuration example of the image display unit 100 in the present embodiment. In FIG. 13, the same parts as those in FIG.

  The image display unit 100 includes a projection unit 180 and an image processing unit 190. The image processing unit 190 corrects the content image signal in accordance with the pixel shift amount obtained by the pixel shift measuring apparatus 200. The projection unit 180 modulates the light from the light source based on the image signal corrected by the image processing unit 190 and projects an image on the screen SCR.

  The image processing unit 190 includes a pixel shift amount storage unit 192 and an image signal correction unit 194. The pixel shift amount storage unit 192 stores the pixel shift amount measured by the pixel shift measuring device 200. More specifically, the pixel shift amount storage unit 192 stores the pixel shift amount measured by the pixel shift measuring apparatus 200 for each display pixel corresponding to the sub pixel of the display image on the screen SCR. Based on the pixel shift amount read corresponding to the pixel position of the display image, the image signal correction unit 194 corrects the image signal of the display pixel at the pixel position for each color component and outputs the corrected image signal to the projection unit 180. .

  FIG. 14 shows a block diagram of a hardware configuration example of the image processing unit 190 of FIG.

  The image processing unit 190 includes a CPU 300, an I / F circuit 310, a read only memory (ROM) 320, a random access memory (RAM) 330, and a bus 340. The CPU 300, the I / F circuit 310, the ROM 320, and the RAM 330 are electrically connected.

  For example, the ROM 320 stores a program for realizing the function of the image processing unit 190 and pixel shift amount data acquired by the pixel shift measuring apparatus 200. The CPU 300 reads out the program stored in the ROM 320 and executes processing corresponding to the program, thereby realizing the functions of the image processing unit 190 described above by software processing. Note that the RAM 330 is used as a work area for processing by the CPU 300 or as a buffer area for the I / F circuit 310 or the ROM 320. The I / F circuit 310 performs input interface processing of an image signal from an image signal generation device (not shown) and input / output interface processing of a control signal from the pixel shift measurement device 200.

  FIG. 15 shows a flowchart of a processing example of the image processing unit 190 of FIG.

  14 stores a program for realizing the processing shown in FIG. 15 in advance, and the CPU 300 reads the program stored in the ROM 320 and executes the processing corresponding to the program. The processing shown can be realized by software processing.

  Here, prior to the processing shown in FIG. 15, it is assumed that the pixel shift amount is determined for each sub-pixel of the display image on the screen SCR by the pixel shift measuring apparatus 200 as described above. In FIG. 15, the reference color component is described as being a G component, but the present invention is not limited to this, and the reference color component may be an R component or a B component.

  First, the image signal correction unit 194 determines whether or not there is an image signal of content (step S30). When it is determined in step S30 that there is no image signal (step S30: N), the image signal correction unit 194 waits for the input of the image signal.

  When it is determined in step S30 that there is an image signal (step S30: Y), the image signal correction unit 194 performs a correction process using the pixel shift amount at the pixel position for each image signal of the color component of the pixel. Do. That is, the image signal correction unit 194 performs a pixel shift amount (a horizontal pixel shift amount and a vertical shift amount) stored in correspondence with the pixel position of the R component sub-pixel with respect to the R component image signal of the content. Correction processing is performed using the pixel shift amount (step S32).

  Subsequently, the image signal correction unit 194 stores a pixel shift amount (a horizontal pixel shift amount and a vertical direction) corresponding to the pixel position of the B component sub-pixel with respect to the B component image signal of the content. Correction processing is performed using the pixel shift amount (step S34).

Here, the image signal correction unit 194 performs the same processing (see FIGS. 4 to 9) as the pixel value correction processing used when the pattern image generation unit 230 generates the pattern image as described above. to correct. For example, when obtaining the pixel value Rout00 of the R component sub-pixel, the pixel values Rin00, Rin10, Rin01, and Rin11 of the pixels around the sub-pixel are obtained, and the pixel value Rout00 is obtained using the following equation.
Rout00 = ((1-α) × Rout00 + α × Rout10) × (1-β) + ((1-α) × Rout01 + α × Rout11) × β

  In the above formula, it is assumed that the pixel shift amount is α pixels in the horizontal direction and the pixel shift amount is β pixels in the vertical direction with respect to the sub-pixel having the pixel value Rin00. The B component in step S34 is similarly obtained.

  As described above, until the correction process is completed for all the sub-pixels in the display image (step S36: N), the process returns to step S32 to perform the correction process for each sub-pixel in the image. On the other hand, when the correction process is completed for all the sub-pixels in the display image (step S36: Y), when the correction process corresponding to the pixel shift amount is not completed (step S38: N), the process returns to step S30 to perform the process. When the correction process corresponding to the pixel shift amount is finished (step S38: Y), the series of processes is finished (end).

  Note that although FIG. 15 has been described assuming that pixel shift amounts in the horizontal direction and vertical direction are stored for all sub-pixels of the display image, the present invention is not limited to this. Only the pixel shift amounts at a plurality of representative points in the display image are stored, and prior to the processing of FIG. 15, the pixel shift amounts at the representative points are used for all sub-pixels of the display image by a known interpolation processing method. The pixel shift amount in the direction and the vertical direction may be obtained.

  As described above, according to the present embodiment, the pixel shift amount corresponding to the pattern image is used to correct the image signal of the content by the same method as the pattern image generation processing method. The pixel shift amount from the device 200 can be accurately reflected in the correction of the image signal. For this reason, even if the pixel shift amount cannot be measured accurately, an image can be displayed so that the false color is most difficult to see.

  FIG. 16 shows a configuration example of the projection unit 180 in the present embodiment. In FIG. 16, the projection unit 180 in the present embodiment is described as being configured by a so-called three-plate type liquid crystal projector, but the projection unit of the image display device according to the present invention is configured by a so-called three-plate type liquid crystal projector. It is not limited to things.

  The projection unit 180 includes a light source 110, integrator lenses 112 and 114, a polarization conversion element 116, a superimposing lens 118, an R dichroic mirror 120R, a G dichroic mirror 120G, a reflection mirror 122, an R field lens 124R, and a G field lens 124G. , R liquid crystal panel 130R (first light modulation unit), G liquid crystal panel 130G (second light modulation unit), B liquid crystal panel 130B (third light modulation unit), relay optical system 140, cross dichroic A prism 160 and a projection lens 170 are included. The liquid crystal panels used as the R liquid crystal panel 130R, the G liquid crystal panel 130G, and the B liquid crystal panel 130B are transmissive liquid crystal display devices. The relay optical system 140 includes relay lenses 142, 144, and 146 and reflection mirrors 148 and 150.

  The light source 110 is composed of, for example, an ultra-high pressure mercury lamp, and emits light including at least R component light, G component light, and B component light. The integrator lens 112 has a plurality of small lenses for dividing the light from the light source 110 into a plurality of partial lights. The integrator lens 114 has a plurality of small lenses corresponding to the plurality of small lenses of the integrator lens 112. The superimposing lens 118 superimposes the partial light emitted from the plurality of small lenses of the integrator lens 112.

  The polarization conversion element 116 includes a polarization separation film and a λ / 2 plate, transmits p-polarized light, reflects s-polarized light, and converts p-polarized light to s-polarized light. The superimposing lens 118 is irradiated with the s-polarized light from the polarization conversion element 116.

  The light superimposed by the superimposing lens 118 is incident on the R dichroic mirror 120R. The R dichroic mirror 120R has a function of reflecting R component light and transmitting G component and B component light. The light transmitted through the R dichroic mirror 120R is applied to the G dichroic mirror 120G, and the light reflected by the R dichroic mirror 120R is reflected by the reflection mirror 122 and guided to the R field lens 124R.

  The dichroic mirror for G 120G has a function of reflecting G component light and transmitting B component light. The light transmitted through the G dichroic mirror 120G enters the relay optical system 140, and the light reflected by the G dichroic mirror 120G is guided to the G field lens 124G.

  In the relay optical system 140, in order to minimize the difference between the optical path length of the B component light transmitted through the G dichroic mirror 120G and the optical path length of the other R component and G component light, the relay lenses 142, 144, 146 is used to correct the difference in optical path length. The light transmitted through the relay lens 142 is guided to the relay lens 144 by the reflection mirror 148. The light transmitted through the relay lens 144 is guided to the relay lens 146 by the reflection mirror 150. The light transmitted through the relay lens 146 is applied to the B liquid crystal panel 130B.

  The light applied to the R field lens 124R is converted into parallel light and is incident on the R liquid crystal panel 130R. The R liquid crystal panel 130R functions as a light modulation element (light modulation unit), and the transmittance (passage rate, modulation rate) changes based on the R image signal. Therefore, the light (first color component light) incident on the R liquid crystal panel 130R is modulated based on the R image signal, and the modulated light is incident on the cross dichroic prism 160.

  The light applied to the G field lens 124G is converted into parallel light and is incident on the G liquid crystal panel 130G. The G liquid crystal panel 130G functions as a light modulation element (light modulation unit), and the transmittance (passage rate, modulation rate) changes based on the G image signal. Therefore, the light (second color component light) incident on the G liquid crystal panel 130G is modulated based on the G image signal, and the modulated light is incident on the cross dichroic prism 160.

  The B liquid crystal panel 130B irradiated with the light converted into parallel light by the relay lenses 142, 144, and 146 functions as a light modulation element (light modulation unit), and has a transmittance (passage rate) based on the B image signal. , Modulation rate) is changed. Therefore, the light (third color component light) incident on the B liquid crystal panel 130B is modulated based on the B image signal, and the modulated light is incident on the cross dichroic prism 160.

  The R liquid crystal panel 130R, the G liquid crystal panel 130G, and the B liquid crystal panel 130B have the same configuration. Each liquid crystal panel is a liquid crystal, which is an electro-optical material, sealed in a pair of transparent glass substrates. For example, a polysilicon thin film transistor is used as a switching element, and the transmittance of each color light corresponding to the image signal of each sub-pixel. Modulate.

  The image signals corrected based on the pixel shift amount for each color component in the image processing unit 190 of the present embodiment are transmitted through the transmittance (passage rate) of the R liquid crystal panel 130R, the G liquid crystal panel 130G, and the B liquid crystal panel 130B, respectively. , Modulation rate).

  The cross dichroic prism 160 has a function of outputting combined light obtained by combining incident light from the R liquid crystal panel 130R, the G liquid crystal panel 130G, and the B liquid crystal panel 130B as outgoing light. The projection lens 170 is a lens that enlarges and forms an output image on the screen SCR, and has a function of enlarging or reducing the image in accordance with the zoom magnification.

  The projection unit 180 in the present embodiment having the above-described configuration can project the light modulated based on the image signal corrected according to the pixel shift amount as described above onto the screen SCR. The image display unit 100 including the projection unit 180 can display each pattern image and display an image based on the pixel shift amount obtained by the pixel shift measuring apparatus 200. At this time, the image display unit 100 can display an image based on the image signal corrected in accordance with the pixel shift amount.

  As described above, the pixel shift measuring device, the image display device, and the pixel shift measuring method according to the present invention have been described based on the above embodiments, but the present invention is not limited to the above embodiments, and departs from the gist thereof. The present invention can be implemented in various modes as long as it is not, for example, the following modifications are possible.

  (1) In the above embodiment, one pixel is described as being composed of three color component sub-pixels, but the present invention is not limited to this. The number of color components constituting one pixel may be 2, or 4 or more.

  (2) In the above embodiment, the shift amount of the R component pixel and the B component pixel is defined on the basis of the G component pixel position as the reference color component. However, the present invention is not limited to this. Absent. For example, an R component or a B component may be adopted as the reference color component. Further, the shift amount of each color component pixel may be defined based on the pixel position of a given reference pixel without selecting the reference color component from a plurality of color components constituting one pixel.

  (3) In the above embodiment, the light valve is used as the light modulation unit. However, the present invention is not limited to this. As the light modulation unit, for example, DLP (Digital Light Processing) (registered trademark), LCOS (Liquid Crystal On Silicon), or the like may be employed.

  (4) In the above embodiment, a light valve using a so-called three-plate transmissive liquid crystal panel as an example of the light modulation unit has been described. However, a light valve using a transmissive liquid crystal panel of four or more plates is used. It may be adopted.

  (5) In the above embodiment, the present invention has been described as a pixel shift measuring device, an image display device, and a pixel shift measuring method, but the present invention is not limited to this. For example, it may be a program in which a processing procedure of a pixel shift measuring method for realizing the present invention is described, or a recording medium on which the program is recorded.

1 is a block diagram of a configuration example of an image display device to which a pixel shift measuring device according to an embodiment is applied. Explanatory drawing of the pattern image in this embodiment. Explanatory drawing of the unit of the deviation | shift amount of the display pixel in this embodiment. Explanatory drawing of the principle of operation of the pattern image generation part in this embodiment. Explanatory drawing of the original pattern image in this embodiment. Explanatory drawing of an example of the pattern image of R component in this embodiment. Explanatory drawing of an example of the pattern image of G component in this embodiment. Explanatory drawing of an example of the pattern image of B component in this embodiment. Explanatory drawing of the other example of the pattern image of R component in this embodiment. The flowchart of the example of a process of the pixel shift measuring apparatus in this embodiment. FIGS. 11A and 11B are explanatory diagrams of the operation of the pixel shift amount determination unit in the present embodiment. Explanatory drawing of the operation example of the pixel deviation | shift amount determination part in this embodiment. FIG. 3 is a block diagram of a configuration example of an image display unit in the present embodiment. FIG. 14 is a block diagram of a hardware configuration example of the image processing unit in FIG. 13. FIG. 5 is a flowchart of an operation example of an image processing unit in the present embodiment. The figure which shows the structural example of the projection part in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image display apparatus, 100 ... Image display part, 110 ... Light source,
112, 114 ... integrator lens, 116 ... polarization conversion element,
118 ... Superimposing lens, 120R ... R dichroic mirror,
120G ... Dichroic mirror for G, 122,148,150 ... Reflective mirror,
124R ... R field lens, 124G ... G field lens,
130R ... R liquid crystal panel, 130G ... G liquid crystal panel,
130B ... Liquid crystal panel for B, 140 ... Relay optical system,
142, 144, 146 ... relay lens, 160 ... cross dichroic prism,
170 ... projection lens, 180 ... projection unit, 190 ... image processing unit,
192: Pixel deviation amount storage unit, 194 ... Image signal correction unit, 200 ... Pixel deviation measurement device,
210: Color measuring unit, 220: Pixel shift amount determining unit, 230 ... Pattern image generating unit,
240 ... pattern image storage unit, 300 ... CPU, 310 ... I / F circuit,
320 ... ROM, 330 ... RAM, 340 ... bus, SCR ... screen,
PAT0 ... Original pattern image

Claims (8)

A pixel shift measuring device for measuring a shift amount of a display pixel,
A measurement unit that acquires a measurement value corresponding to the shift amount of the display pixel of each pattern image constituting a plurality of pattern images having different pixel shift amounts;
And a pixel shift amount determination unit that selects one of the plurality of pattern images based on a measurement value corresponding to each pattern image and obtains a shift amount corresponding to the selected pattern image. measuring device. In claim 1,
The measurement unit is
Obtain a measurement value that increases as the false color increases, or a measurement value that decreases as the false color increases;
The pixel shift amount determination unit
A pixel shift measuring apparatus, wherein a pattern image having the maximum or minimum measured value is selected. In claim 2,
The measurement unit is
Obtaining a measurement value corresponding to the color component of each pattern image;
The pixel shift amount determination unit
A pixel shift measuring apparatus, wherein a pattern image that minimizes an average value of the measured values of the entire screen is selected from the plurality of pattern images. In any one of Claims 1 thru | or 3,
A pixel deviation measuring apparatus, comprising: a pattern image storage unit that stores the plurality of pattern images having different pixel deviation amounts in a horizontal direction or a vertical direction of the pattern image. In any one of Claims 1 thru | or 4,
The plurality of pattern images are
A pixel deviation measuring apparatus, wherein the pixel deviation measurement apparatus is an image generated so that pixel deviation amounts differ from each other with respect to a binary image having a line width of one pixel in a grid pattern. In any one of Claims 1 thru | or 5,
The plurality of pattern images are
The pattern image is provided for each of the remaining color components excluding the reference color component among a plurality of color components constituting one pixel, and the shift amounts of the sub-pixels of the respective color components of the remaining color components are different from each other. A pixel shift measuring device. A pixel shift measuring device according to any one of claims 1 to 6,
An image display unit that displays each pattern image and displays an image based on the shift amount;
The image display unit is
An image display device that displays an image based on an image signal corrected in accordance with the shift amount. A pixel shift measuring method for measuring a shift amount of a display pixel,
A measurement step for obtaining a measurement value corresponding to the shift amount of the display pixel of each pattern image constituting a plurality of pattern images having different pixel shift amounts;
And a pixel shift amount determination step of selecting one of the plurality of pattern images based on a measurement value corresponding to each pattern image and obtaining a shift amount corresponding to the selected pattern image. Measuring method.

Images