JP2012085225A - Image quality adjustment system and image quality adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image quality adjustment system and an image quality adjustment method to adjust an image quality of a display panel, using a photographed image in which moire generation is suppressed.SOLUTION: An image quality adjustment device 20 is connected to a photographic camera 30, a test pattern generator 41, and a ROM writer 42. The photographic camera 30 is provided with a rotation device 31 to rotate with the vertical axis of a CCD element as a rotary shaft. Moreover, a control section 21 of the image quality adjustment device 20 is provided with a rotation adjustment table storing a rotation angle for suppressing moire generation. The control section 21 specifies the size of a liquid crystal panel and specifies the rotation angle of the camera using the rotation adjustment table. Then, the control section 21 instructs the rotation device 31 to rotate at the specified angle. Then, the control section 21 performs irregularity measurement, correction data generation, and correction data writing.

Description

  The present invention relates to an image quality adjustment system and an image quality adjustment method for adjusting the image quality of a display panel using a captured image in which moiré is suppressed.

  Today, a production line for a display panel such as a liquid crystal panel is constructed so as to achieve uniform quality. However, even in such a production line, manufacturing variations occur in individual display panels. Thus, a technique for adjusting each display panel so that a better image can be output has been studied (for example, see Patent Document 1). In the technique described in Patent Document 1, the control unit of the image quality adjustment device generates a test pattern, supplies the test pattern to the liquid crystal panel, and acquires an output image from the photographing camera. Then, bandpass filtering is performed on the output image data to calculate a correction value. When the calculation of the image correction table is completed for all the reference gradations, it is written in the ROM of the correction circuit. For an image signal for displaying an image on the liquid crystal panel, a linearly interpolated correction value is calculated with reference to an image correction table recorded in the ROM.

  In inspection of a display panel, it is known that moire occurs when an image displayed on the display panel is photographed with a camera using a CCD (CCD camera). This moire occurs when the luminance of light received by pixels arranged in a regular grid pattern repeats regular changes little by little. That is, the display panel and the CCD, which are pixels of the display image, are arranged in a regular lattice pattern. However, the relative position shift between each pixel of the display panel and each pixel of the CCD causes a change in the CCD. Moire occurs when the luminance of the light of the display panel received by the pixels repeatedly changes little by little regularly.

  Moire has a large difference in density and becomes an obstacle when inspecting display unevenness of a display panel. Therefore, it is necessary to remove the moire. In this case, ideally (theoretical), moire does not occur if there is no relative displacement between each pixel of the display panel and each pixel of the CCD, but it is not possible to make this displacement zero. Have difficulty.

  Therefore, a technique for removing moire generated when a display image on a display panel is captured has been studied (for example, see Patent Document 2). In the technique described in this document, the exposure of the CCD camera at the start position is opened to start capturing the display image on the display screen, and the XZ stage is simultaneously driven in the horizontal and vertical directions to display the CCD camera on the display screen. Move diagonally along. When the CCD camera reaches the end position, the exposure is closed and the driving by the XZ stage is stopped, and the display image acquisition is completed. Thereby, while the CCD camera is moving obliquely, a display image on the display screen by the CCD camera is acquired. The amount of movement of the CCD camera by the XZ stage is determined by the number of dots that determines the resolution of the display panel, and the CCD camera is driven simultaneously by the horizontal dot pitch in the horizontal direction and the vertical dot pitch in the vertical direction.

  Further, a technique for obtaining an image with reduced moire by image processing has been studied (for example, see Patent Document 3). In the technique described in this document, a spatial axis signal representing an image in which moire has occurred is converted into a frequency axis signal, a frequency component corresponding to moire is removed from the frequency axis signal, and a frequency corresponding to moire is obtained. The frequency axis signal from which the component is removed is converted into a spatial axis signal.

JP 2010-57149 A (first page, FIG. 1) Japanese Patent Laying-Open No. 2005-72816 (first page, FIG. 1) JP 2008-11334 A (first page, FIG. 1)

As described in the patent document, when moiré occurs, the original display unevenness cannot be measured, and thus there is a problem that accurate correction data cannot be generated.
However, the method of Patent Document 2 requires precise control for accurately moving the camera horizontally while keeping the focus on the display panel, and it takes time to control the horizontal movement of the camera. There is a problem that the efficiency is low and the cost increases. In addition, the method of removing moire by image processing in Patent Document 3 requires a complicated image processing program, which takes time for the image processing and has a problem of poor adjustment efficiency.

  Further, the “deviation” between the pixels of the display panel and the CCD pixels is affected by panel attributes such as the panel size and resolution. For example, when a display panel is imaged with a fixed focus lens, “displacement” due to the following factors can be considered in imaging at a fixed distance.

(1) When the panel resolution is fixed (for example, a resolution of 1920 × 1080 dots), the panel pixel and the CCD pixel are shifted according to the panel size.
(2) When the panel size is fixed (for example, 40 inches), the panel pixel and the CCD pixel are shifted in accordance with the resolution of the panel such as 1920 × 1080 dots or 1366 × 768 dots.
It is necessary to suppress moire in consideration of such causes.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an image quality adjustment system and an image quality adjustment method for adjusting the image quality of a display panel using a captured image in which moiré is suppressed. There is to do.

  In order to solve the above problems, the invention according to claim 1 supplies the image signal to be displayed on the display panel and also displays the display from the photographing means for measuring the luminance of each pixel displayed on the display panel. An image quality adjustment system including a control unit that acquires a captured image of a panel, wherein the control unit specifies a rotation angle that suppresses the occurrence of moire according to the attribute of the display panel to be adjusted; Means for rotating the photographing means at the rotation angle around the vertical direction with respect to the surface of the display panel; and means for generating an image obtained by converting an image photographed by the photographing means according to the rotation angle; The gist is provided with means for evaluating display unevenness using the converted image, and means for generating correction data for correcting the display unevenness.

  According to a second aspect of the present invention, in the image quality adjustment system according to the first aspect of the present invention, the image quality adjustment system further includes a rotation angle information storage unit that stores information about a rotation angle corresponding to the attribute of the display panel. The gist is to acquire information related to the attribute of the target display panel and specify the rotation angle corresponding to the attribute from the rotation angle information storage means.

  According to a third aspect of the present invention, in the image quality adjustment system according to the first aspect, a uniform image signal is supplied to the display panel, and the intensity of moire generated in a photographed image photographed using photographing means is calculated. Then, the gist is to specify a rotation angle at which the intensity is smaller than a reference value.

  A fourth aspect of the present invention is the image quality adjustment system according to any one of the first to third aspects, wherein the photographing unit is rotated using a rotation angle at which the intensity of the moire is minimized. And

  The invention according to claim 5 supplies the image signal to be displayed on the display panel, and obtains a photographed image of the display panel from the photographing means for measuring the luminance of each pixel displayed on the display panel. The control means specifies a rotation angle that suppresses the occurrence of moiré in accordance with the attribute of the display panel to be adjusted. And a step of rotating the photographing means by the rotation angle about a direction perpendicular to the surface of the display panel, and generating an image obtained by converting the image photographed by the photographing means according to the rotation angle. The gist is to execute a step, a step of evaluating display unevenness using the converted image, and a step of generating correction data for correcting the display unevenness.

(Function)
According to the first or fifth aspect of the invention, the control means specifies the rotation angle that suppresses the occurrence of moire according to the attribute of the display panel to be adjusted. Then, the photographing unit is rotated by a rotation angle with the vertical direction as an axis with respect to the surface of the display panel. An image obtained by converting the image photographed by the photographing unit according to the rotation angle is generated, and the display unevenness is evaluated using the converted image, and correction data for correcting the display unevenness is generated. Thereby, depending on the attributes of the display panel, moire caused by the pixels of the display panel and the pixels of the photographing unit can be suppressed, so that the display unevenness inherent in the display panel can be measured. Then, accurate correction data can be generated for image quality adjustment. Note that the panel size and resolution can be used as the attributes of the display panel.

  According to the invention described in claim 2, the rotation angle corresponding to the attribute of the display panel is specified using the rotation angle information storage means. Although the occurrence of moiré varies depending on the attributes of the display panel, image quality adjustment can be performed using a rotation angle that takes this occurrence into consideration.

  According to the third aspect of the present invention, the intensity of the moire generated in the captured image captured using the imaging unit is calculated, and the rotation angle at which the intensity is smaller than the reference value is specified. Thereby, even when the state of occurrence of moiré differs depending on the status of the display panel and the photographing means, it is possible to specify an accurate rotation angle for suppressing moiré.

  According to the fourth aspect of the present invention, the photographing means is rotated using the rotation angle at which the intensity of the moire is minimized. As a result, the influence of moire can be reduced and image quality adjustment can be performed.

  According to the present invention, it is possible to provide an image quality adjustment system and an image quality adjustment method for adjusting the image quality of a display panel using a captured image in which the occurrence of moire is suppressed.

Explanatory drawing of the image quality adjustment system of this invention. It is explanatory drawing of the process sequence of this invention, Comprising: (a) is the process sequence of 1st Embodiment, (b) is explanatory drawing of the process sequence of 2nd Embodiment.

<First Embodiment>
Hereinafter, a first embodiment of the image quality adjustment system of the present invention will be described. In the present embodiment, it is assumed that image quality is improved by suppressing display unevenness (brightness unevenness) of the display panel to be adjusted. Here, in order to suppress the occurrence of moire during image quality adjustment, the photographing unit is rotated by a predetermined angle with the photographing direction connecting the display panel to be adjusted and the photographing unit as the central axis. In this embodiment, a rotation adjustment table in which a rotation angle is registered in advance is used. In the present embodiment, the liquid crystal panel 10 having a constant panel resolution is used as the adjustment target product (display panel).

  The liquid crystal panel 10 includes a liquid crystal (liquid crystal unit) sandwiched between transparent electrodes and a backlight that illuminates the liquid crystal from the back. For this reason, the liquid crystal panel 10 outputs an image in which the unevenness of the liquid crystal part and the peripheral light reduction of the backlight are superimposed.

  Therefore, in order to improve the image quality of the liquid crystal panel 10, the liquid crystal panel 10 includes a correction circuit 50 for adjusting the supplied image signal as shown in FIG. The image signal (RGB signal) for displaying an image on the liquid crystal panel 10 is supplied to the liquid crystal panel 10 and the correction circuit 50.

As shown in FIG. 1, the correction circuit 50 includes a non-volatile memory (ROM 51), a selection / interpolation unit 52, and an addition unit 53 in order to adjust the image quality.
This ROM 51 stores data (image correction table) relating to correction values for adjusting the signal value of the input image signal. In the present embodiment, a planar distribution of correction values is stored for each reference gradation.

The selection / interpolation means 52 refers to the image correction table recorded in the ROM 51 for each RGB signal. Here, the selection / interpolation means 52 is a correction determined by four block grid points surrounding the pixel position (xy coordinate) of the image signal in the image correction table of two reference gradations adjacent to each RGB signal value of the image signal. A value (2 × 4 = 8) is acquired. Then, the selection / interpolation means 52 performs linear interpolation on the acquired correction value according to the distance between the signal value of the image signal and each grid point.
The adding unit 53 adds the correction value acquired from the selecting / interpolating unit 52 to the input image signal. The liquid crystal panel 10 acquires the corrected image signal and displays an image.

As shown in FIG. 1, the image quality adjustment system for calculating the correction value includes an image quality adjustment device 20, a photographing camera 30, a test pattern generation device 41, and a ROM writer.
The image quality adjustment device 20 is connected to the photographing camera 30, the test pattern generation device 41, and the ROM writer 42.

  Here, the photographing camera 30 as photographing means photographs an image displayed on the liquid crystal panel 10 and supplies output image data to the image quality adjustment apparatus 20. In the present embodiment, a monochrome camera including a CCD element that can resolve an area smaller than the pixel size of the display panel is used as the photographing camera 30. Then, the image displayed on the liquid crystal panel 10 is taken.

  The photographing camera 30 is provided with a rotation device 31 for rotating the vertical axis of the CCD element as a rotation axis. The rotating device 31 is configured to move the photographing camera 30 around the photographing direction (front direction) connecting the display panel to be adjusted and the photographing means in response to a rotation instruction from the control unit 21 of the image quality adjusting device 20 described later. Rotate. By this rotation, the pixel arrangement of the CCD element can be rotated with respect to the pixel arrangement of the liquid crystal panel 10 to be adjusted.

A test pattern generation device 41 as a signal generation unit supplies a test pattern signal to the liquid crystal panel 10 based on an instruction from the image quality adjustment device 20. In the present embodiment, 8-bit RGB signals are supplied to the entire surface of the liquid crystal panel 10.
The ROM writer 42 writes the image correction table in the ROM 51 of the liquid crystal panel 10 to be adjusted.

  The image quality adjustment device 20 is a computer terminal that executes processing for calculating a correction value for adjusting the image quality of the liquid crystal panel 10. The image quality adjustment apparatus 20 includes a control unit 21, a correction information storage unit 22, and a display. This display is used when an administrator of the adjustment process of the liquid crystal panel 10 confirms the adjustment status and the like.

  The control unit 21 includes a CPU, a RAM, a ROM, and the like as control means, and performs processing (processing including a moire adjustment stage, an unevenness measurement stage, a correction data generation stage, etc.) described later. By executing the correction data creation program for this purpose, the control unit 21 functions as the moire adjustment unit 211, the unevenness measurement unit 212, and the correction data generation unit 213.

  The moiré adjustment unit 211 performs a process of adjusting the rotation angle of the photographic camera 30 in order to suppress the occurrence of moiré during the photographing of the liquid crystal panel 10. In the present embodiment, the moire adjustment unit 211 includes a rotation adjustment table (rotation angle information storage unit) that stores a rotation angle for suppressing the occurrence of moire. In this rotation adjustment table, information related to the rotation angle for suppressing the occurrence of moire is stored in correspondence with the panel size (panel attribute) of the liquid crystal panel 10 to be adjusted. The moire adjustment unit 211 provides the rotation device 31 with a rotation instruction including the rotation angle specified using the adjustment table.

  The unevenness measuring unit 212 provides an image signal to the liquid crystal panel 10 to be adjusted, and acquires a captured image of an image output according to the image signal from the imaging camera 30. Then, the light emission intensity (characteristic information) of each pixel is calculated based on the captured image.

  The correction data generation unit 213 executes processing for generating correction information corresponding to the characteristic information of the adjustment target product. Specifically, a correction value is calculated based on an image displayed on the liquid crystal panel 10, and an image correction table configured by the calculated correction value is recorded in the correction information storage unit 22.

  The correction information storage unit 22 stores correction data (image correction table) for correcting the image of each liquid crystal panel 10. This correction data is registered when an image correction table is acquired from the image quality adjustment apparatus 20. The correction information storage unit 22 temporarily stores correction data (image correction table for suppressing display unevenness for each predetermined gradation) to be written in the ROM 51 of the liquid crystal panel 10.

  The display of the image quality adjustment device 20 is used by an administrator of the adjustment process of the liquid crystal panel 10 to check the adjustment status and the like. Specifically, a message is output to this display when error processing described later is performed.

A process for adjusting the image quality of the liquid crystal panel 10 will be described with reference to FIG.
(Panel adjustment processing)
This panel adjustment process is performed using the image quality adjustment device 20.
First, the control unit 21 of the image quality adjustment apparatus 20 executes a process for specifying the size of the liquid crystal panel (step S1-1). Specifically, the moire adjustment unit 211 of the control unit 21 uses the photographing camera 30 to obtain a photographed image obtained by photographing the liquid crystal panel 10. In this case, the moire adjustment unit 211 uses the zoom function of the photographing camera 30 to photograph the entire panel. Then, the moire adjustment unit 211 specifies the panel size of the liquid crystal panel 10 to be adjusted using the size of the liquid crystal panel 10 reflected in the photographed image and the enlargement ratio by the zoom function.

  Next, the control unit 21 of the image quality adjustment apparatus 20 executes a camera rotation process (step S1-2). Specifically, the moire adjustment unit 211 of the control unit 21 acquires a rotation angle corresponding to the panel size from the rotation adjustment table. The moire adjusting unit 211 supplies the rotation device 31 with a rotation instruction including the rotation angle acquired from the rotation adjustment table. In response to this instruction, the rotation device 31 rotates the CCD element (the photographing camera 30) at a specified rotation angle. Further, the moire adjusting means 211 supplies this rotation angle to the unevenness measuring means 212.

  Next, the control unit 21 of the image quality adjustment apparatus 20 performs unevenness measurement processing (step S1-3). Specifically, the unevenness measuring unit 212 of the control unit 21 instructs the test pattern generation device 41 to output an RGB signal for outputting an image of the gradation to be adjusted. Here, in the gradation to be adjusted, signals having the same R signal value, G signal value, and B signal value (common signal values) are used for the entire surface of the liquid crystal panel 10. In response to this instruction, the test pattern generator 41 supplies the liquid crystal panel 10 with an 8-bit RGB signal that is the gradation to be adjusted.

  In response to this, the liquid crystal panel 10 outputs a gray image of the adjustment target gradation. In this case, when the liquid crystal has uneven cell gaps or uneven backlights, the liquid crystal panel 10 has display unevenness in which these unevennesses are superimposed. Here, the imaging camera 30 captures an image on which display unevenness is superimposed.

  Then, the unevenness measuring means 212 takes in output image data obtained by photographing the liquid crystal panel 10 from the photographing camera 30. Then, the unevenness measuring unit 212 generates a converted image obtained by rotating the output image using the rotation angle acquired from the moire adjusting unit 211 by, for example, affine conversion. Note that the rotation conversion method is not limited to affine transformation. Then, the converted image data is converted into a luminance distribution for each block composed of 8 × 8 pixels.

  Next, the unevenness measuring unit 212 executes a filtering process. Specifically, the unevenness measuring unit 212 calculates bandpass data by performing bandpass filtering on the acquired converted image data. This band pass data is composed of a distribution excluding low frequency components and high frequency components according to the in-plane luminance distribution of the liquid crystal panel 10.

  Next, the control unit 21 of the image quality adjustment apparatus 20 executes a correction data generation process (step S1-4). Specifically, the correction data generation unit 213 of the control unit 21 generates an image correction table in which bandpass data is inverted. Specifically, the distribution of correction values on the liquid crystal panel 10 is calculated for each preset gradation (reference gradation). In the present embodiment, a predetermined number (for example, 10 levels) of reference gradations are used in a signal value expressed in 8 bits. Then, the adjustment target gradation corresponding to the reference gradation is sequentially changed for each step, and an image correction table is generated for each adjustment target gradation. Further, the correction information generation means temporarily stores an image correction table in the correction information storage unit 22 in association with an identifier for specifying the adjusted reference gradation.

  When the adjustment is completed, the control unit 21 of the image quality adjustment apparatus 20 executes a correction data writing process (step S1-5). Specifically, the correction data generation unit 213 of the control unit 21 supplies the image correction table extracted from the correction information storage unit 22 to the ROM writer 42. In this case, the ROM writer 42 writes the image correction table in the ROM 51 of the liquid crystal panel 10. As a result, the distribution of correction values is recorded in the ROM 51 with respect to the block position (xy coordinates) in the plane of the liquid crystal panel 10 for each reference gradation.

According to this embodiment, the following effects can be obtained.
(1) In the present embodiment, the control unit 21 of the image quality adjustment device 20 executes a camera rotation process (step S1-2). Thereby, the arrangement of the pixels of the CCD element can be changed with respect to the arrangement of the pixels of the liquid crystal panel 10 to be adjusted to suppress the occurrence of moire. Unlike the case of suppressing moire by defocusing, it is possible to suppress the occurrence of moire while maintaining the resolution.

  (2) In the present embodiment, the control unit 21 of the image quality adjustment device 20 executes a process for specifying the size of the liquid crystal panel (step S1-1). Although the occurrence of moire differs depending on the panel size of the liquid crystal panel 10 to be adjusted, an appropriate rotation angle can be set in consideration of this situation.

  (3) In the present embodiment, the moire adjustment unit 211 supplies the rotation angle to the unevenness measurement unit 212. Then, the unevenness measuring unit 212 generates a converted image obtained by rotating the output image using the rotation angle acquired from the moire adjusting unit 211 by affine transformation. Thus, the original pixel arrangement of the liquid crystal panel 10 can be specified, and correction data in this arrangement can be set.

<Second Embodiment>
Next, a second embodiment of the panel adjustment process embodying the present invention will be described with reference to FIG. Note that the second embodiment has a configuration in which only the moire adjustment process of the first embodiment is changed, and thus detailed description of the same parts is omitted. In the present embodiment, the state of occurrence of moiré is confirmed during image quality adjustment, and the rotation angle of the photographing unit is determined. For this reason, in order to determine the necessity of moire adjustment, the moire adjustment means 211 of the control unit 21 holds data relating to the reference value for the intensity of moire fringes (moire intensity). Further, the control unit 21 is provided with a work memory for storing data on the moire intensity with respect to the rotation angle.

  Here, first, the control unit 21 of the image quality adjustment apparatus 20 executes a uniform image signal input process (step S2-1). Specifically, the moire adjustment unit 211 of the control unit 21 instructs the test pattern generator 41 to supply a uniform image signal to the liquid crystal panel 10 to be adjusted. In the present embodiment, an RGB signal for outputting an intermediate gradation image to the entire surface of the liquid crystal panel 10 is supplied. In response to this, the liquid crystal panel 10 outputs a gray image of the adjustment target gradation.

  Next, the control unit 21 of the image quality adjustment apparatus 20 performs moire measurement processing (step S2-2). Specifically, the moire adjustment unit 211 of the control unit 21 uses the photographing camera 30 to instruct photographing of the output image of the liquid crystal panel 10. The moire adjustment unit 211 captures output image data obtained by photographing the liquid crystal panel 10 from the photographing camera 30. In this case, an image on which display unevenness or moire is superimposed is taken. In this case, the moire adjustment unit 211 calculates low-pass data by performing low-pass filtering for detecting moire fringes. Next, the moire adjustment unit 211 calculates the moire intensity in the low-pass data. The moire adjusting unit 211 records the calculated moire intensity in the work memory in association with the rotation angle (here, 0 degrees).

  Next, the control unit 21 of the image quality adjustment apparatus 20 performs a determination process as to whether or not the image quality adjustment apparatus 20 is within an allowable range (step S2-3). Specifically, the moire adjusting means 211 of the control unit 21 compares the moire intensity with a predetermined reference value. Here, when the moire intensity is equal to or less than the reference value, it is determined that the value is within the allowable range.

When the moiré intensity is within the allowable range (in the case of “YES” in step S2-3), the control unit 21 of the image quality adjustment device 20 performs the unevenness measurement process (step S2-) as in steps S1-3 to S1-5. 11) A correction data generation process (step S2-12) and a correction data writing process (step S2-13) are executed.

  On the other hand, when the moiré intensity is not within the allowable range (in the case of “NO” in step S2-3), the control unit 21 of the image quality adjustment apparatus 20 executes a camera rotation process (step S2-4). Specifically, the moire adjusting means 211 of the control unit 21 instructs the rotating device 31 to rotate at a predetermined minute angle.

  Next, the control unit 21 of the image quality adjustment apparatus 20 performs the moire measurement process as in step S2-2 (step S2-5). In this case, the moire adjustment unit 211 records the calculated moire intensity in the work memory in association with the rotation angle (here, a minute angle).

Next, similarly to step S2-3, the control unit 21 of the image quality adjustment apparatus 20 performs a determination process as to whether or not the image is within the allowable range (step S2-6).
When the moiré intensity is within the allowable range (in the case of “YES” in step S2-6), the control unit 21 of the image quality adjustment device 20 performs the unevenness measurement process (step S2-) as in steps S1-3 to S1-5. 11) to the correction data writing process (step S2-13) is executed.

  On the other hand, when the moiré intensity is not within the allowable range (in the case of “NO” in step S2-6), the control unit 21 of the image quality adjustment device 20 performs a determination process as to whether or not the moiré intensity has a minimum value (step). S2-7). Specifically, the moire adjustment means 211 of the control unit 21 determines that there is a minimum value when the moire intensity stored in the work memory decreases according to the rotation angle and then increases. .

  When the moiré intensity has no minimum value (in the case of “NO” in step S2-7), the control unit 21 of the image quality adjustment device 20 repeats the processing from the camera rotation processing (step S2-4). When the moire intensity increases according to the rotation angle, the rotation direction of the rotation device 31 is reversed.

  On the other hand, if the moiré intensity has a minimum value (in the case of “YES” in step S2-7), the control unit 21 of the image quality adjustment apparatus 20 executes setting processing at the angle of the minimum value (step S2-8). ). Specifically, the moire adjustment unit 211 of the control unit 21 acquires the rotation angle associated with the minimum value of the moire intensity in the work memory. The moire adjustment unit 211 instructs the rotation device 31 to rotate the acquired rotation angle.

Next, similarly to step S2-3, the control unit 21 of the image quality adjustment apparatus 20 executes a determination process as to whether the minimum value is within the allowable range (step S2-9).
When the minimum value is within the allowable range (in the case of “YES” in step S2-9), the control unit 21 of the image quality adjustment device 20 performs the unevenness measurement process (step S2—as in steps S1-3 to S1-5). 11) to the correction data writing process (step S2-13) is executed.

  On the other hand, even if the minimum value of the moire intensity is not within the allowable range (in the case of “NO” in step S2-9), the control unit 21 of the image quality adjustment apparatus 20 executes the defocus processing (step S2-10). . Specifically, the moire adjustment unit 211 of the control unit 21 defocuses the photographic camera 30 until the moire intensity falls within an allowable range while performing moire measurement. Then, the control unit 21 of the image quality adjustment apparatus 20 executes the unevenness measurement process (step S2-11) to the correction data writing process (step S2-13), similarly to steps S1-3 to S1-5.

According to this embodiment, the following effects can be obtained.
(4) In this embodiment, the control part 21 of the image quality adjustment apparatus 20 performs a moire measurement process (step S2-2). When the moiré intensity is not within the allowable range (in the case of “NO” in step S2-3), the control unit 21 of the image quality adjustment device 20 executes camera rotation processing (step S2-4). When the moiré intensity is within the allowable range (in the case of “YES” in step S2-6), the control unit 21 of the image quality adjustment device 20 performs the unevenness measurement process (step S2-) as in steps S1-3 to S1-5. 11) to the correction data writing process (step S2-13) is executed. Thereby, the moire can be suppressed by the rotation only when the moire is generated.

  (5) In this embodiment, when the moire intensity is not within the allowable range (in the case of “NO” in step S2-6), the control unit 21 of the image quality adjustment apparatus 20 determines whether or not the moire intensity has a minimum value. Processing is executed (step S2-7). Thereby, even when moire cannot be suppressed, image quality adjustment can be performed by setting a rotation angle at which the moire intensity is minimized.

  (6) In the present embodiment, when the moiré intensity has a minimum value (in the case of “YES” in step S2-7), the control unit 21 of the image quality adjustment device 20 executes setting processing at the angle of the minimum value. (Step S2-8). If the minimum value of the moire intensity is not within the permissible range (in the case of “NO” in step S2-9), the control unit 21 of the image quality adjustment apparatus 20 executes defocus processing (step S2-10). . Thereby, even when the moire cannot be suppressed by the rotation of the imaging means, the moire can be suppressed by defocusing.

Moreover, you may change the said embodiment as follows.
In the first embodiment, the process for specifying the size of the liquid crystal panel is executed (step S1-1). Here, the panel size is specified using the photographing camera 30. The method for specifying the panel size is not limited to this, and may be set by an input unit connected to the image quality adjustment apparatus 20.

  In the first embodiment, the liquid crystal panel 10 having a constant panel resolution is used as the adjustment target product, and the rotation angle for suppressing the occurrence of moire is specified in correspondence with the panel size as the panel attribute. . The panel attribute for specifying the rotation angle is not limited to the panel size, and the rotation angle may be specified using the resolution of the panel. In this case, the liquid crystal panel 10 having a constant panel size is set as a product to be adjusted, and the rotation adjustment table has a rotation angle for suppressing the occurrence of moire in accordance with the resolution of the liquid crystal panel 10 to be adjusted. The information regarding is stored. Then, the image quality adjustment device 20 acquires the resolution of the product to be adjusted and rotates the rotation angle using the rotation adjustment table. As a method for acquiring the resolution, the resolution is set by an input unit connected to the image quality adjustment device 20, or is acquired from the adjustment target product data storage unit in which the resolution is registered for the product number of the liquid crystal panel 10. In the latter case, the image quality adjustment device 20 acquires the product number stored in the liquid crystal panel 10 or the product number set by the input unit, and acquires the resolution from the adjustment target product data storage unit.

Further, the rotation angle for suppressing the occurrence of moire may be stored in the rotation adjustment table in accordance with a plurality of panel attributes (size and resolution). In this case, the image quality adjustment apparatus 20 acquires a plurality of panel attributes (size and resolution) and specifies the rotation angle.
Accordingly, it is possible to suppress the occurrence of moire according to various attributes of the display panel.

In the second embodiment, first, the control unit 21 of the image quality adjustment apparatus 20 performs a uniform image signal input process (step S2-1). Here, as in the first embodiment, the process for specifying the size of the liquid crystal panel (step S1-1) and the camera rotation process (step S1-2) may be executed. Thereby, the rotation angle which suppresses a moire efficiently can be calculated by setting a preset rotation angle as an initial value.

  In the above embodiment, camera rotation processing is executed (steps S1-2 and S2-4). Here, unevenness measurement processing (steps S1-3, S2-11) to correction data writing processing (steps S1-5, S2-13) are performed using one rotation angle with respect to the liquid crystal panel 10 to be adjusted. Execute. Alternatively, the camera rotation angle need not be fixed. For example, in each adjustment area of the liquid crystal panel 10 to be adjusted, the rotation angle may be changed according to the state of occurrence of moire. In this case, the liquid crystal panel 10 is divided into a plurality of areas, and the moire adjusting means 211 of the control unit 21 measures the occurrence of moire for each area. The moire adjustment unit 211 determines the rotation angle according to the occurrence state, and executes the unevenness measurement process to the correction data writing process. When the panel size of the panel to be adjusted is large, the occurrence state of moire varies depending on the location and the elevation angle from the photographing camera 30, but an appropriate rotation angle can be set according to the occurrence state.

  DESCRIPTION OF SYMBOLS 10 ... Liquid crystal panel, 20 ... Image quality adjustment apparatus, 21 ... Control part, 211 ... Moire adjustment means, 212 ... Unevenness measurement means, 213 ... Correction data generation means, 22 ... Correction information storage part, 30 ... Shooting camera, 31 ... Time Moving device 41... Test pattern generator 42. ROM writer 50. Correction circuit 51.

Claims (5)

An image quality adjustment system including a control unit that supplies an image signal to be displayed on a display panel and acquires a captured image of the display panel from an imaging unit for measuring the luminance of each pixel displayed on the display panel. ,
The control means is
Corresponding to the attribute of the display panel to be adjusted, means for specifying a rotation angle for suppressing the occurrence of moire,
Means for rotating the photographing means according to the rotation angle about a direction perpendicular to the surface of the display panel;
Means for generating an image obtained by converting the image photographed by the photographing means according to the rotation angle;
Means for evaluating display unevenness using the converted image;
An image quality adjustment system comprising: means for generating correction data for correcting the display unevenness. Rotation angle information storage means for storing information related to the rotation angle corresponding to the attributes of the display panel,
The control means acquires information related to the attributes of the display panel to be adjusted,
The image quality adjustment system according to claim 1, wherein a rotation angle corresponding to the attribute is specified from the rotation angle information storage unit. Supply a uniform image signal to the display panel, calculate the intensity of the moire generated in the photographed image photographed using the photographing means,
The image quality adjustment system according to claim 1, wherein a rotation angle at which the intensity is smaller than a reference value is specified.   The image quality adjustment system according to claim 1, wherein the photographing unit is rotated using a rotation angle at which the intensity of the moire is minimized. Using an image quality adjustment system provided with a control unit that supplies an image signal to be displayed on the display panel and acquires a captured image of the display panel from an imaging unit for measuring the luminance of each pixel displayed on the display panel A method of adjusting the image quality of the display panel,
The control means is
Corresponding to the attributes of the display panel to be adjusted, identifying a rotation angle that suppresses the occurrence of moire,
Rotating the imaging means at the rotation angle with respect to the direction perpendicular to the surface of the display panel;
Generating an image obtained by converting the image photographed by the photographing means according to the rotation angle;
Using the converted image to evaluate display unevenness;
And a step of generating correction data for correcting the display unevenness.

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