JP2007121243A - Device and method for inspecting image display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device and method which inspects precisely and quickly a defect in an image display panel for displaying images in two or more of different directions. <P>SOLUTION: The inspected panel 2 for displaying the independent images in the two or more of different image display directions is held in a panel holding stage 11, and an inspecting display signal is imparted to the inspected panel 2 by a lighting circuit 12. The inspected panel 2 imparted with the inspecting display signal is imaged respectively from the image display directions by line sensor cameras 10a, 10b, while moving the inspected panel 2, to acquire an image data. The defect in the image display panel is detected, based on the comparison of the image data imaged from the respective image display directions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection method and an inspection apparatus for an image display panel capable of displaying a plurality of images having parallax.

  In recent years, an image display panel capable of displaying independent images with respect to two or more different directions (hereinafter referred to as image display directions), that is, a multi-image display panel, has been used in various applications in recent years.

  By using the multi-image display panel and displaying the right-eye image and the left-eye image in the direction in which the viewer's right eye and left eye are positioned, stereoscopic viewing by the observer can be realized. Multi-image display panels that realize stereoscopic viewing have been put to practical use in applications such as entertainment and virtual reality.

  In addition, if the above-described multiple image display panel is used, independent images can be displayed for a plurality of observers located in different directions with respect to the image display panel for the purpose of protecting privacy and ensuring safety. is there.

  The multi-image display panel that displays independent images in two or more different directions includes a transmissive light source capable of emitting light in each image display direction, and the light emission direction of the light source and the transmission 2. Description of the Related Art An image display panel that displays different images in each display direction by switching an image to be displayed on a type image display panel every very short time is known. In addition, the image display panel includes a parallax generation device that limits the light emission direction, and controls the direction of the light emitted from the display area for each display area to any one of the image display directions, thereby A multi-image display panel that displays different images is also known.

  As an element that determines the display quality of the multi-image display panel, display direction characteristics (luminance distribution with respect to the observation direction) of the image display panel are important. In particular, it is important that light is correctly emitted from each display area of the image display panel in a predetermined image display direction. A typical defect in a multi-image display panel is a crosstalk defect in an adjacent display area. Here, the crosstalk defect refers to a first display area that emits light in the first image display direction and a first display that emits light in a second image display direction different from the first image display direction. When there is a second display area adjacent to the area, the light emission direction in the first display area is not correctly controlled, and the light emitted from the second display area is changed from the first display area to the light. The emitted light has an effect.

  An image display panel before product shipment is usually inspected using a visual inspection or a defect inspection apparatus. In particular, for example, a defect inspection apparatus 100 shown in FIG. 9 is known as an apparatus for performing a defect inspection relating to display direction characteristics of an image display panel (Patent Document 1).

  The defect inspection apparatus 100 includes an inspection unit 110 including a condensing lens 101 and a two-dimensional sensor array 102 in which a plurality of sensor elements are two-dimensionally arranged. The display surface of the panel to be inspected 103 is arranged so as to coincide with the front focal position.

  Light rays emitted in one direction from one image display area 103 a of the panel to be inspected are converted into parallel light rays by the condenser lens 101 and enter each sensor element constituting the two-dimensional sensor array 102. That is, the display direction characteristic of the display area 103a is detected as the intensity of light received by each light receiving element constituting the two-dimensional sensor array when the inspection unit 110 is located at the illustrated position. Further, the inspection unit 110 is moved relative to the panel 103 to be inspected, and the entire display area of the inspection panel 103 is two-dimensionally scanned, so that the display direction characteristic regarding each display area of the inspection panel 103 can be obtained. Measured.

  However, in the defect detection apparatus 100, even when the inspection unit 110 is at the illustrated position, light emitted from a display area other than the display area 103a (for example, light emitted from the display area 103b) is two-dimensional. Incident light is incident on the sensor array 102.

  Therefore, the defect inspection apparatus 200 shown in FIG. 10 includes the first lens 201, the pinhole 202, the second lens 203, and a two-dimensional sensor array 204 in which a plurality of sensor elements are two-dimensionally arranged. Has been proposed (Patent Document 1).

  According to the above configuration, when the inspection unit 210 is at the illustrated position, the light emitted from the display area other than the display area 103a cannot pass through the pinhole 202. , It is possible to inspect the display direction characteristics relating to the display area 103a).

  Further, as another apparatus that performs defect inspection relating to the image display panel display direction characteristics, an inspection apparatus 300 shown in FIG. 11 is known (Patent Document 2).

  The defect inspection apparatus 300 includes a condenser lens 301 and a two-dimensional sensor array 302 formed by two-dimensionally arranging a plurality of sensor elements. The condenser lens 301 is arranged on the two-dimensional sensor array 302. Are arranged so that a real image of the panel 103 to be inspected is formed. That is, the light emitted from one display area in the panel 103 to be inspected is collected by the condenser lens 301 and enters one light receiving element constituting the two-dimensional sensor array 103.

In the inspection apparatus 300, the display direction characteristic for each display region is measured by moving the inspection unit 310 including the condenser lens 301 and the two-dimensional sensor array 302 relative to the panel 103 to be inspected. Is done.
JP 2002-333407 (Publication date: November 22, 2002) Japanese Patent Laid-Open No. 2001-281049 (Publication date: October 10, 2001)

  However, for the multi-image display panel as described above, it is necessary to observe the multi-image display panel from a plurality of angles, and it is difficult to quantify the defective state by visual inspection, and the inspection accuracy is not stable. There is a problem.

  The above-described conventional defect inspection apparatus is intended to evaluate the angular distribution of luminance in an image display panel that does not have a special image display direction. The defect inspection apparatus can be used as a multi-image display panel. In application, it is difficult to detect a crosstalk defect. Furthermore, there is a problem that the inspection speed is slow or the inspection accuracy is low.

  The above problem will be described in more detail as follows.

  When inspecting an image display panel using the defect inspection apparatus 200 of Patent Document 1, it is possible to simultaneously observe light emitted in each direction from a certain display region. However, in the defect detection apparatus 200, the display direction characteristics are inspected for each display area, and the influence of adjacent display areas is removed. For this reason, it has not been possible to directly measure the influence of light emitted from another display area that should emit light in another display direction, that is, the influence of crosstalk, on a multi-image display panel.

  In addition, in order to perform a precise inspection of an image display panel, the number of display areas serving as an inspection unit needs to be set to the same level as the number of pixels of the image display panel. In the inspection apparatus that requires two-dimensional scanning when inspecting the entire display area of the image display panel, there is a problem that a sufficient inspection speed cannot be obtained.

  In view of the above inspection speed problem, in the defect inspection apparatus 200, it is possible to increase the inspection speed by arranging a plurality of inspection units 210 one-dimensionally or two-dimensionally. However, the configuration including the plurality of inspection units 210 brings about a new problem that the cost of the defect inspection apparatus increases.

  When inspecting an image display panel using the defect inspection apparatus 300, it is possible to simultaneously observe all display areas constituting the image display panel. However, when the defect detection apparatus 300 is used for a multi-image display panel and the light emission state with respect to the image display direction of the multi-image display panel is inspected, the display direction is changed for each image display direction of the multi-image display panel. It is necessary to appropriately move the inspection unit 310 to a position where the image display panel is viewed and inspect the light emission state in each image display direction.

  For this reason, it has been difficult to simultaneously detect images displayed in the respective display directions by the multi-image display panel using the defect inspection apparatus 300 and detect defects in the multi-image display panel based on the comparison of these images. .

  In the defect inspection apparatus 300, the inspection unit 310 can be moved so that the angle at which the sensor array 302 looks at one display area of the panel to be inspected is constant. However, even in this case, since the optical path length from the display area to the two-dimensional sensor array differs for each display area of the panel to be inspected, it is difficult to focus on each display area.

  The present invention has been made in view of the above-mentioned problems, and its object is to display the display direction characteristics of the above-described multiple image display panel, in particular, the control state of the emission direction in each display region, or the crosstalk defect with high accuracy and high speed. It is to implement an inspection apparatus and an inspection method that can be evaluated or detected.

  An inspection method for an image display panel according to the present invention is an inspection method for detecting a defect in an image display panel that displays independent images for two or more different image display directions, and is provided with a display signal for inspection. In the image display panel, the defect detection of the image display panel is performed based on the comparison between the image data acquisition process for acquiring the image data captured from each image display direction and the image data captured from each image display direction. And a defect detection step to be performed.

  An inspection apparatus for an image display panel according to the present invention that enables the above-described inspection method is an inspection apparatus that detects a defect in an image display panel that displays independent images for two or more different image display directions. A panel holding unit for holding the image display panel, a signal supply unit for supplying an inspection display signal to the image display panel, and an image display direction for each of the image display panels to which the inspection display signal is applied. And an image data acquisition unit for acquiring image data picked up from.

  According to the above configuration, image data captured from each image display direction by the image data acquisition unit with respect to the image display panel held in the panel holding unit and supplied with the display signal for inspection from the signal supply unit. Is acquired.

  In this image data, for example, if a decrease in luminance is detected in the display area of the image data (pixels set to emit light in the imaged direction), the image display set in that pixel is displayed. It can be determined that light is not emitted correctly in the direction. Further, for example, if an increase in luminance is detected in a non-display area of the image data (a pixel set so as not to emit light in the direction in which the image is captured), a leak that causes crosstalk in the pixel. It can be determined that light is generated.

  And in the said image data, the visual recognition state from the same image display direction is reflected in all the pixels on data. As a result, the defect inspection as described above is performed on the image display panel displaying independent images in two or more different image display directions, and the image data for the inspection is converted into a special optical system or image processing device. The inspection apparatus can be realized at low cost. Furthermore, it is possible to perform defect inspection quickly while minimizing the acquisition of image data for inspection.

  Further, in the image display panel inspection method, in the image data acquisition step, while moving an imaging device that detects the luminance of a one-dimensional region on the image display panel relative to the image display panel, It is preferable that the image data is acquired by imaging the entire surface of the image display panel.

  According to the above configuration, the area on the image display panel that is imaged by the imaging apparatus with one imaging is a one-dimensional area. For this reason, high-quality image data free from optical distortion and focus fluctuation can be obtained. Therefore, defect determination based on the high-quality image data can be performed, and the accuracy of defect inspection for the image display panel can be improved.

  In order to move the imaging apparatus relative to the image display panel, the imaging apparatus may be moved in the inspection apparatus, or the image display panel (panel holding unit that holds the image display panel) may be moved. May be.

  In the image display panel inspection method, in the image data acquisition step, as the inspection display signal, a signal for displaying the same image in all image display directions of the image display panel is provided, and the defect A configuration in which, in the detection step, a difference between corresponding display areas or non-display areas corresponding to each image data is taken, and it is determined that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. It is preferable to do.

  According to said structure, the signal which gives the signal which performs the same image display with respect to all the image display directions of an image display panel, and if it images from each image display direction with respect to this image display panel, image data obtained Then, a display area detected with high luminance and a non-display area detected with low luminance alternately occur.

  Then, if the difference is obtained so that the corresponding display areas or non-display areas corresponding to the respective image data overlap each other, the difference value is substantially 0 on the entire surface of the panel when there is no defect in the image data panel. That is, if a reference value is determined in advance in consideration of the influence of noise or the like, and there is a pixel whose difference value is larger than this value, it can be determined that the pixel has a defect. By taking the difference between the image data in this way, defect detection can be performed simultaneously on a plurality of image data having different image display directions, and the inspection can be speeded up.

  In addition, the image display panel includes a plurality of image data acquisition units corresponding to the respective image display directions in the inspection apparatus in order to perform the same image display in all the image display directions. If the image data corresponding to is acquired at the same time, it is possible to speed up the processing even in the image data acquisition step.

  In the image display panel inspection method, in the image data acquisition step, an image having a uniform gradation that is not black with respect to all image display directions of the image display panel is displayed as an inspection display signal. In the defect detection step, a pixel having a defect can be determined by comparing the detection value of each pixel with a predetermined threshold for each image data.

  According to the above configuration, if a signal for performing a uniform gradation image is given to all the image display directions of the image display panel, and the image display panel is imaged from each image display direction. In the obtained image data, a display area detected with high luminance and a non-display area detected with low luminance alternately occur.

  Then, the display area in each image data is compared with a specific threshold value, and if a pixel having a luminance lower than the threshold value is detected in the pixel in the display area, the pixel correctly emits light in the set image display direction. It can be determined that no injection has occurred. Further, the non-display area in each image data is compared with a specific threshold value, and if a pixel having a luminance higher than the threshold value is detected in a pixel in the non-display area, leak light that causes crosstalk is detected in the pixel. Can be determined.

  In the above-described defect method, defect determination can be performed for each image data having different image display directions, so that determination with high accuracy is possible.

  In the image display panel inspection method, in the image data acquisition step, as a display signal for inspection, pixels in the display area are displayed with a non-black uniform gradation image, and pixels in the non-display area are displayed. In the defect detection step, a difference between corresponding display areas or non-display areas of each image data is taken, and the difference value is larger than a predetermined reference value. On the other hand, it can be set as the structure which judges that the defect has generate | occur | produced.

  Alternatively, in the inspection method for the image display panel, in the image data acquisition step, the pixels in the display area are caused to perform image display with a non-black uniform gradation as the display signal for inspection, and the pixels in the non-display area Is provided with a signal for performing black display, and in the defect detection step, for each image data, a detection value of each pixel is compared with a predetermined threshold to determine a pixel in which a defect has occurred. It can be.

  According to the above configuration, the image data in the image display direction to be inspected is displayed with a non-black uniform gradation image display on the pixels in the display area and black display on the pixels in the non-display area. Let it be done. For this reason, only the control state of the emission direction of the light emitted in the image display direction to be inspected is evaluated with high accuracy after eliminating the influence of the light to be emitted in the image display direction that is not the inspection target. Is possible.

  In the image data acquisition step, as a display signal for inspection, a signal for causing the pixels in the display area to perform black display and for the pixels in the non-display area to perform image display with a uniform gradation that is not black is given. In the defect detection step, a pixel in which a defect is generated can be determined by comparing the detection value of each pixel with a predetermined threshold for each image data.

  According to the above configuration, for the image data in the image display direction to be inspected, the pixels in the display area are displayed in black, and the pixels in the non-display area are displayed with a non-black uniform gradation image. Let it be done. For this reason, after eliminating the influence of the light to be emitted in the image display direction to be inspected, the light to be emitted in a different image display direction is displayed on the image displayed in the display direction to be inspected. It is possible to evaluate the influence on the object with high accuracy.

  In the image display panel inspection apparatus, a computer may be used as a control unit, and the control unit may control the panel holding unit and the image data acquisition unit to acquire the image data. In this case, a program for causing a computer to function as control means and a computer-readable recording medium on which the program is recorded are also included in the scope of the present invention.

  In the image display panel inspection apparatus, the defect detection unit may be realized by a computer. In this case, a program for causing a computer to function as the defect detection unit and a computer-readable recording medium on which the program is recorded are also included in the scope of the present invention.

  As described above, an inspection method for an image display panel according to the present invention is an inspection method for detecting defects in an image display panel that displays independent images in two or more different image display directions. For the image display panel to which the display signal is given, the above image display is based on the comparison of the image data acquisition process for acquiring the image data captured from each image display direction and the image data captured from each image display direction. And a defect detection step for detecting a defect in the panel.

  An inspection apparatus for an image display panel according to the present invention that enables the above-described inspection method is an inspection apparatus that detects a defect in an image display panel that displays independent images for two or more different image display directions. A panel holding unit for holding the image display panel, a signal supply unit for supplying an inspection display signal to the image display panel, and an image display direction for each of the image display panels to which the inspection display signal is applied. And an image data acquisition unit that acquires image data picked up from.

  Therefore, in the image data, the visual recognition state from the same image display direction is reflected in all the pixels on the data. As a result, image data for inspection can be acquired without using a special optical system or image processing device for an image display panel that displays independent images for two or more different image display directions. The device can be realized at low cost. Furthermore, it is possible to perform defect inspection quickly while minimizing the acquisition of image data for inspection.

  Embodiments according to the present invention will be described below with reference to FIGS.

  In the following description, the panel to be inspected that is inspected by the inspection apparatus or the inspection method according to the present invention is a transmissive image display panel, and two images having parallax are represented by the observer's right eye direction and left eye direction. An image display panel to be displayed. However, the panel to be inspected is specified for convenience of description, and the image display panel that can be inspected by the inspection apparatus or inspection method according to the present invention is not limited to this.

  In addition, the image displayed on the panel to be inspected is a monochrome image, and in the drawing, the display area with high luminance is white, the display area with low luminance is black, and the display area at the intermediate luminance is hatched. Is expressed. However, the monochrome image is specified for simplification of description, and the image display panel can be inspected by the inspection apparatus or the inspection method according to the present invention, but the image display panel is not limited to the image display panel displaying the monochrome image. Absent.

  First, the configuration of the inspection apparatus according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the defect inspection apparatus 1 includes an inspection unit 10, a panel holding stage 11, a lighting circuit 12, a contact unit 13, a transmitted illumination 14, a peripheral device control unit 15, an image processing device 16, and an output unit 17. And inspecting the panel 2 to be inspected.

  The inspection unit 10 includes two line sensor cameras 10a and 10b. The line sensor camera 10a and the line sensor camera 10b are image pickup means in which image pickup devices (for example, CCD (Charge-Coupled Device) devices) are arranged in a one-dimensional shape (column shape). It is possible to image the original area. The one-dimensional area imaged by the line sensor camera 10a or the line sensor camera 10b can be appropriately determined according to the image display characteristics of the panel 2 to be inspected or necessary inspection items. That is, the one-dimensional region may be a single pixel column, or may be a region composed of several adjacent pixel columns. Or conversely, the line sensor camera may have a resolution capable of decomposing one pixel row into a plurality of one-dimensional regions.

  In the present embodiment, the configuration using the above-described line sensor camera as an imaging device will be described, but the inspection device according to the present invention is not necessarily limited to this. That is, the imaging apparatus provided in the inspection apparatus according to the present invention may be any means that can image a one-dimensional area on the panel to be inspected and detect the luminance of the one-dimensional area. For example, the imaging apparatus may be an imaging apparatus that includes one or more imaging elements and detects the luminance of the one-dimensional area by scanning the one-dimensional area that is an imaging target. In addition, a so-called TDI (time delay difference method) sensor that detects the luminance of each display area on the one-dimensional area by imaging the one-dimensional area to be imaged a plurality of times and integrating or averaging the imaging results. There may be.

  The inspection unit 10 is configured such that the line sensor camera 10a and the line sensor camera 10b are arranged at a position where a common one-dimensional area on the panel to be inspected 2 can be imaged from two image display directions. Alternatively, the inspection unit 10 includes a mechanism that adjusts the positions and angles of the line sensor camera 10a and the line sensor camera 10b, and the line sensor camera 10a and the line sensor camera 10b correspond to the panel to be inspected according to the panel 2 to be inspected. The common one-dimensional region on 2 is adjusted to a position where it can be imaged from two image display directions.

  The panel to be inspected 2 is held by a panel holding stage 11. The panel holding stage 11 is provided with a mechanism for moving the panel 2 to be inspected in a direction (x-axis direction shown in the figure) orthogonal to the one-dimensional region imaged by the line sensor camera. For this reason, the one-dimensional area imaged by the line sensor camera 10a and the line sensor camera 10b can be sequentially moved on the panel 2 to be inspected. That is, the entire panel to be inspected can be scanned by the line sensor camera.

  The panel to be inspected 2 held by the panel holding stage 11 is connected to the lighting circuit by the contact portion 13. That is, a driving signal is given to the panel to be inspected 2 by the lighting circuit 12 through the contact portion 13.

  If the panel to be inspected 2 is provided with driving means such as a source driver and a gate driver in advance, the panel to be inspected 2 and the lighting circuit 12 are connected by an FPC (Flexible Print Circuit) or a connector. Is also possible.

  When the inspected panel 2 is a transmissive image display panel and is a semi-finished product that does not include a transmissive light source, the transmissive illumination 14 is used as a transmissive light source for a one-dimensional region imaged by the line sensor cameras 10a and 10b. In addition, if the to-be-inspected panel 2 is an image display panel provided with a transmissive light source, the defect inspection apparatus 1 may be configured without the transmissive illumination 14.

  The panel 2 to be inspected is installed on the panel holding stage 11 by a transfer device or manually. Thereafter, the peripheral device control unit 15 turns on the transmissive illumination 14 and causes the lighting circuit 12 to start supplying a drive signal to the panel 2 to be inspected. At the same time, the peripheral device control unit 15 causes the panel holding stage 11 to start moving the panel 2 to be inspected. Thereby, the entire display surface of the panel 2 to be inspected is sequentially imaged by the line sensor camera 10a and the line sensor camera 10b for each one-dimensional area. Image signals captured by the line sensor camera 10 a and the line sensor camera 10 b are sent to the image processing device 16.

  Next, a transmission-type image display panel that displays a plurality (two in this case) of images having parallax in the right eye direction and the left eye direction of the observer, which is a panel to be inspected, will be described with reference to FIG. Further, in line with the panel 2 to be inspected, the arrangement of the line sensor camera 10a and the line sensor camera 10b in the inspection unit 10 provided in the defect inspection apparatus 1 and the two line sensor cameras simultaneously capture images. The one-dimensional region will be specifically described.

  FIG. 2A shows an actual image display state of the panel 2 to be inspected, and shows how it is viewed from the front in a state where there is virtually no parallax. That is, the image (character 'L') displayed in the left eye direction of the observer shown in FIG. 2 (e) and the image (character 'X') displayed in the right eye direction of the observer shown in FIG. 2 (f). ') At the same time.

  FIG. 2A shows a virtual appearance in the absence of parallax. Actually, as shown in FIG. 2B, the parallax generation device 21 is added to the matrix type display device 22. Thus, the image presented to the left viewer is separated from the image presented to the right viewer. FIG. 2B shows the A-A ′ cross section of FIG. When the horizontal direction of the matrix type display device 22 is a row, the vertical direction is a column, and the minimum unit of display is a pixel, the parallax generation device 21 displays an odd-numbered column of pixels only in the left-eye direction, The light emission direction in each pixel is controlled so that the pixel is displayed only in the right eye direction. By limiting the light emission direction of each pixel of a matrix display device to the right eye direction and the left eye direction for each pixel column using a parallax generation device, different image data can be simultaneously presented to the left and right observers. It has become. That is, the image shown in FIG. 2 (a) looks like FIG. 2 (e) to the observer in the left eye direction and looks like FIG. 2 (f) to the observer in the right eye direction.

  As described above, the arrangement of the line sensor camera 10a and the line sensor camera 10b can be adjusted according to the viewing angle characteristics of the panel 2 to be inspected. More specifically, the line sensor camera 10a and the line sensor camera 10b are adjusted so that two adjacent pixel columns are simultaneously imaged from the left eye direction and the right eye direction in accordance with the characteristics of the panel 2 to be inspected. Note that two adjacent pixel columns that are simultaneously imaged by the left and right line sensor cameras 10a and 10b correspond to the same one-dimensional region of an image displayed on the image display panel.

  As shown in FIG. 2 (c), the image captured by the line sensor camera 10a whose arrangement has been adjusted as described above while moving the panel 2 to be inspected has pixel columns with low luminance for each pixel column. The image that appears. Similarly, as shown in FIG. 2D, the image captured by the line sensor camera 10b whose arrangement is adjusted as described above is an image in which low-luminance pixel columns appear every other pixel column. .

  In the image displayed in the left-eye direction shown in FIG. 2C, a pixel column with high luminance (hereinafter referred to as an image display pixel column (display region)) and a pixel column with low luminance (hereinafter, image non-display pixel column). (Referred to as non-display areas) appear alternately. This is because the light emission direction in each pixel column is controlled by the parallax generation device so that the odd pixel columns emit light in the left eye direction and the even pixel columns emit light in the right eye direction. This is because only the light emitted from the laser beam enters the line sensor camera 10a, and the light emitted from the even pixel row does not enter the line sensor camera 10a. In FIG. 2D, the pixel rows with high luminance and the pixel rows with low luminance appear alternately for the same reason.

  When the panel to be inspected is viewed, the display resolution of the panel to be inspected is sufficiently high, so that the pixel columns with low luminance appearing every other column as shown in FIGS. 2 (c) and 2 (d) As shown in FIG. 2E or FIG. 2F, the image of the character “L” or the character “X” is observed.

  Next, a basic method for detecting a defect in the panel 2 to be inspected based on the images taken by the line sensor camera 10a and the line sensor camera 10b will be described with reference to FIGS. First, the case where there is no defect in the panel 2 to be inspected will be described with reference to FIG.

  FIG. 3A shows an image when the panel to be inspected displaying the same white image in the left-eye direction and the right-eye direction is observed from the front in a state where there is virtually no parallax. That is, the panel to be inspected 2 is given a uniform white signal as an image signal to be displayed in the left-eye direction and the right-eye direction by the lighting circuit 12, and the odd-numbered pixel column is lighted correctly in the left-eye direction and the even-numbered pixel column is correctly illuminated in the right-eye direction. Shall be ejected. For simplification of description, in the following description, the odd-numbered pixel columns are eight columns L0 to L7 and the even-numbered pixel columns are eight columns R0 to R7, and a display image is formed with a total of 16 pixel columns. It is supposed to be.

  FIG. 3B shows an image obtained by imaging the panel 2 to be inspected with no defects from the left eye direction with the line sensor camera 10a, and FIG. 3C shows the panel 2 to be inspected with the line sensor camera 10b in the right eye direction. It is the image imaged from.

  Here, the image captured by the left line sensor 10a (FIG. 3B) is moved by the panel holding stage 11 in the direction orthogonal to the pixel columns captured by the two line sensor cameras at the same time. However, it is an image obtained by sequentially imaging each pixel row of L0, R0, L1, R1,..., L7. Similarly, the image (FIG. 3C) captured by the right line sensor camera 10b was obtained by sequentially imaging each pixel row of R0, L1, R1,..., L7, R7. It is an image.

  The two images shown in FIG. 3B and FIG. 3C captured by the line sensor camera are sent to the image processing device 16. The image processing device 16 calculates the difference between both images taken from each display direction. Speaking of the panel to be inspected, with respect to the pixel columns corresponding to the same display area, the luminance difference in each pixel constituting the pixel column is calculated.

  FIG. 3D is a difference image in which the brightness difference obtained with respect to the images shown in FIG. 3B and FIG. When the same white image is displayed in the left-eye direction and the right-eye direction and the panel 2 to be inspected does not include a defect, the image is captured by the line sensor camera 10a in the left-eye direction and the line sensor camera 10b in the right-eye direction. The images are the same, and all the luminance differences are 0 as shown in FIG.

  Note that the luminance difference calculation for the images captured from each display direction may be performed for each one-dimensional display area captured by the line sensor camera as described above, or a plurality of one-dimensional display areas. The image signal for the arbitrary line may be recorded, and the stored image for the arbitrary line may be collectively recorded.

  When the images picked up from the respective display directions are the same, that is, when no difference in luminance is detected with respect to the images picked up from the respective display directions, the output unit 17 outputs a determination result that there is no defect in the panel to be inspected. .

  Next, when the panel to be inspected 2 includes a point defect, a method for detecting the defect will be described with reference to FIG. Here, in particular, due to a partial failure of the parallax generation device 21, the light emission direction in some pixels is not correctly controlled in the predetermined image display direction, and the pixel is observed when the pixel is observed from the predetermined image display direction. A description will be given of a defect in which the luminance does not reach a predetermined value. Thus, when a white image is displayed, a defect in which the pixel does not correctly display a white image due to an electrical abnormality or optical abnormality of the pixel is referred to as a black spot defect.

  A uniform white signal is given to the panel 2 to be inspected as the same image signal displayed in the right eye direction and the left eye direction. FIG. 4A shows how the panel to be inspected 2 to which the image signal is given is viewed from the front in a state where there is virtually no parallax. As will be described later, in the panel 2 to be inspected, there are black spot defects in some pixels, but FIG. 4A is a virtual diagram that does not define the observation direction. Not shown.

  Images taken by the line sensor camera 10a and the line sensor camera 10b of the panel 2 to be inspected having the black spot defect are shown in FIGS. 4 (b) and 4 (c). At this time, it is assumed that due to a partial failure of the parallax generation device 21, a luminance drop is observed in the pixel KL1 of the pixel row L1 in the image captured by the line sensor camera 10a. Similarly, in the image captured by the line sensor camera 10b due to a partial failure of the parallax generation device 21, a decrease in luminance is observed in the pixels KR1 and KR5 of the pixel columns R1 and R5.

  The image captured by the line sensor camera 10a shown in FIG. 4 (b) is compared with the image captured by the line sensor camera 10b shown in FIG. 4 (c), and a luminance difference is determined for each pixel. By taking it, the difference image shown in FIG. 4D is obtained. Here, P1, P2,..., P7 correspond to differences between image display pixel columns, and Q1, Q2,..., Q7 correspond to differences between image non-display pixel columns. In the difference image, the black spot defect KR5 is detected as a pixel having a luminance difference larger than a predetermined reference value. The predetermined reference value is a value determined as an allowable error in consideration of the influence of noise or the like, and can be arbitrarily set according to the required inspection accuracy.

  In the above description, a uniform white signal is given as an image signal to be displayed in the right eye direction and the left eye direction in the non-inspection panel 2, but is given to the non-inspection panel 2 for detecting defective pixels based on the difference image. The image signal is not limited to this. That is, when only the inspection based on the difference image is performed, the image signal may be arbitrary as long as the image signal given in the right eye direction and the image signal given in the left eye direction are the same.

From the difference image shown in FIG. 4D, no defect in KL ₁ and KR ₁ corresponding to the same display area is detected. That is, when a similar defect (a black spot defect with an equivalent gray value) exists in pixels that correspond to the same display area and display an image in different display directions, the above-described defect detection alone using the difference image A defect cannot be detected.

  In order to prevent the above problem, a threshold test may be performed for each image captured from each image display direction. Specifically, a luminance profile may be obtained for each pixel column imaged by the line sensor camera, and a pixel whose luminance is lower than the threshold value may be detected as a luminance reduction portion.

FIG. 4E shows a luminance profile related to the pixel column L1 shown in FIG. A black spot defect in KL1 is detected as a pixel having a luminance lower than the illustrated threshold value Th0. FIG. 4F shows a luminance profile for the pixel columns R1 and R5 shown in FIG. According to the above profile, it is possible to detect a black spot defect in KR ₁ and KR ₅ as a pixel having a luminance lower than the illustrated threshold Th0.

  By assigning high pixel values to the pixels detected as defects based on the above-described difference image and the pixels corresponding to the pixels detected as defects based on the above-described profile for each pixel column, as shown in FIG. In addition, detection result image data having all the information of black spot defects existing in the panel 2 to be inspected can be obtained.

  In the above description, threshold processing in the case where light is not emitted in a predetermined image display direction in some pixels due to a partial failure of the parallax generation device 21 and the luminance of the defective pixel is reduced in the image display direction. Explained. However, this is not limited to defects caused by defects in the parallax generation device 21, but may include defective pixels (or it) due to disturbances in the alignment characteristics of the liquid crystal due to inclusion of foreign matters in the liquid crystal layer, or due to electrical defects in the TFT elements themselves. There is also a defect in which the luminance in the image display direction of (adjacent pixels) is higher than a predetermined luminance. For such a defect, it is possible to detect a defect by setting an upper limit luminance in the threshold processing and detecting pixels exceeding this as a luminance increase portion. Moreover, in order to detect the said brightness | luminance raise site | part, the said threshold value process is implemented with respect to the image non-display pixel row | line | column of each line sensor camera image.

  In the above description, for the purpose of detecting black spot defects, the inspection performed by giving a uniform white image signal to the panel 2 to be inspected has been described. For this reason, a uniform value is used as the threshold value Th0 in FIGS. However, it is also possible to execute the inspection by giving a signal other than the white signal. For example, the inspection can be executed using an image signal having an arbitrary intermediate gradation as long as it is a signal for displaying an image having a uniform gradation that is not black. In this case, an appropriate threshold value can be set according to the drive signal given to the panel 2 to be inspected, and the threshold value processing can be performed. Moreover, it is also possible to perform simultaneously the threshold value process which detects the pixel which is less than the minimum brightness | luminance mentioned above, and the threshold value process which detects the pixel which exceeds an upper limit brightness | luminance as needed.

  When the drive signal given to the panel to be inspected 2 is a complex image signal, it is difficult to set the threshold value in the above threshold processing. In this case, the inspection based on the above-described difference image is effective.

  On the contrary, as described in the above description, defect detection by threshold processing is effective when a uniform image signal is given to the panel 2 to be inspected and inspection is performed. For this reason, according to the drive signal given to the panel 2 to be inspected, it is possible to appropriately combine the inspection based on the threshold processing and the inspection based on the difference image, or to perform only one of the inspections.

  In the above description, the difference image for all the pixel columns between the image shown in FIG. 4B captured by the line sensor camera 10a and the image shown in FIG. 4C captured by the line sensor camera 10b is shown. Although the inspection performed based on the above has been described, if only the black spot defect is an inspection target, a difference image for only the image display pixel column of the two images may be used. However, if the inspection generates a differential image for all pixel columns, there is an advantage that a crosstalk defect described later can be detected at the same time.

  Next, when the panel to be inspected 2 includes a crosstalk defect, a method for detecting the defect will be described with reference to FIG. Here, the crosstalk defect means, for example, that the light emission direction is not correctly controlled in the pixel that should emit light in the right eye direction, and the light from the pixel that should emit light in the right eye direction to the observer in the left eye direction. This is a defect in which the emitted light is observed.

  A uniform white signal is given to the panel 2 to be inspected as the same image signal displayed in the right eye direction and the left eye direction. FIG. 5A shows how the panel 2 to be inspected to which the image signal is given is viewed from the front in a state where there is virtually no parallax. In the panel 2 to be inspected, there is a crosstalk defect in some pixels as will be described later, but FIG. 5A is a virtual diagram that does not define the observation direction. Is not shown.

  Images taken by the line sensor camera 10a and the line sensor camera 10b of the panel 2 to be inspected having the crosstalk defect are shown in FIGS. 5 (c) and 5 (d).

  In FIG. 5C, the pixel column R0 and the pixel column R5 are represented by intermediate gradations. This is because, as shown in FIG. 5B, the light emitted from the pixel row R0 and the pixel row R5 whose emission direction should be controlled in the right eye direction is incident on the line sensor camera 10a located in the left eye direction. is there. Further, in FIG. 5D, the pixel row L1 is expressed by an intermediate gradation. This is because light emitted from the pixel row L1 whose emission direction should be controlled in the left eye direction is incident on the line sensor camera 10b located in the right eye direction.

  The image captured by the line sensor camera 10a shown in FIG. 5C is compared with the image captured by the line sensor camera 10b shown in FIG. 5D, and a luminance difference is determined for each pixel. By taking this, the difference image shown in FIG. 5E is obtained. Here, P1, P2,..., P7 correspond to differences between image display pixel columns, and Q1, Q2,..., Q7 correspond to differences between image non-display pixel columns. In the difference image, the pixel column Q5 is detected as a pixel column having a luminance difference larger than a predetermined reference value. The predetermined reference value is a value determined as an allowable error in consideration of the influence of noise or the like, and can be arbitrarily set according to the required inspection accuracy.

  In the above description, a uniform white signal is given as an image signal to be displayed in the right eye direction and the left eye direction in the non-inspection panel 2, but is given to the non-inspection panel 2 for detecting defective pixels based on the difference image. The image signal is not limited to this. That is, when only the inspection based on the difference image is performed, the image signal may be arbitrary as long as the image signal given in the right eye direction and the image signal given in the left eye direction are the same.

  A defect in which the pixel row L0 corresponding to the same display area is the pixel row R0 is not detected from the difference image shown in FIG. That is, when there is a similar defect in pixels that correspond to the same display area and display an image in different display directions, the above-described defect can be obtained only by detecting a defect based on a difference image of images captured from each image display direction. Cannot be detected.

  In order to prevent the above problem, a threshold test may be performed for each image captured from each image display direction. Specifically, a luminance profile may be obtained for each pixel column imaged by the line sensor camera, and a pixel column exceeding a preset threshold value may be detected as a crosstalk defect.

FIG. 5F shows the luminance profiles related to the pixel column R0, the pixel column R1, and the pixel column R5 shown in FIG. In FIG. 5 (f), the as pixels having a brightness above a threshold Th ₁ shown, all the pixels constituting the pixel row R0 and the pixel row R5 are detected. Accordingly, the pixel column R0 and the pixel column R5 are detected as pixel columns exceeding a preset threshold value, that is, pixel columns having a crosstalk defect. The pixel row R1 shown for comparison is a pixel row in which the light emission direction is correctly controlled. Therefore, the light emitted from the pixel row R1 does not enter the line sensor camera 10a installed in the left eye direction. For this reason, in the image shown in FIG. 5C captured by the line sensor camera 10a, the luminance of the pixel row R1 is lower than the threshold Th1.

  FIG. 5G shows a luminance profile regarding the pixel columns L1 and L2 shown in FIG. According to the above profile, all the pixels constituting L1 are detected as pixels having a luminance exceeding the illustrated threshold value Th1. Thereby, the pixel column L1 is detected as a pixel column exceeding a preset threshold value, that is, a pixel column having a crosstalk defect. Further, regarding the pixel column L2 shown for comparison, since the luminance in all the pixels is lower than the threshold value Th1, no crosstalk defect is detected in the pixel column L2.

  By assigning a high pixel value to the pixel detected as a defect based on the above-described difference image and the pixel corresponding to the pixel detected as a defect by the threshold processing prior to the above-described comparison, a pixel value shown in FIG. Detection result image data having all the information of the crosstalk defect existing in the inspection panel 2 is obtained.

  The threshold processing described above can be performed on the image display pixel column of each line sensor camera image data as necessary. In this case, pixels that fall below the preset threshold value are detected at the same time as the crosstalk defect is detected. It can be detected as a lowered site.

  In the above description, for the purpose of detecting a crosstalk defect, a case where inspection is performed by giving a uniform white image signal to the panel 2 to be inspected is illustrated. For this reason, a uniform value is used as the threshold Th1. However, according to the image display quality required for the inspection target, it is also possible to execute the inspection by giving a drive signal other than the white color to the panel 2 to be inspected. For example, the inspection can be executed using an image signal having an arbitrary intermediate gradation as long as it is a signal for displaying an image having a uniform gradation that is not black. In this case, the threshold used for the threshold processing may be appropriately set according to the drive signal given to the panel 2 to be inspected. In addition, both the upper limit and the lower limit of the threshold value can be set as necessary.

  When the drive signal given to the panel 2 to be inspected is a complex image signal, the threshold setting is also complicated. In this case, the inspection based on the above-described difference image is effective.

  On the contrary, when a uniform image signal is given to the panel 2 to be inspected and the inspection is executed, defect detection by threshold processing is effective. For this reason, according to the drive signal given to the panel 2 to be inspected, it is possible to appropriately combine the inspection based on the threshold processing and the inspection based on the difference image, or to perform only one of the inspections.

  In the above description, the difference image for all the pixel columns between the image shown in FIG. 5C captured by the line sensor camera 10a and the image shown in FIG. 5D captured by the line sensor camera 10b is shown. Although the inspection performed based on the above has been described, if only the crosstalk defect is the inspection target, a difference image for only the image non-display pixel column of the two images may be used. However, if the inspection generates a differential image for all pixel columns, there is an advantage that the black spot defect can be detected at the same time.

  As described above, when the panel to be inspected does not have a defect, has a black spot defect, and has a crosstalk defect, the function of the inspection apparatus according to the present invention and a part of the inspection method according to the present invention are described. explained. In the above description, a point-like defect or a line-like defect due to a defect in the parallax generation device is detected. However, the cause of the detectable defect is not limited to this, and the point-like defect is caused by an electric defect. Detection of defects or linear defects is also possible.

  Next, a series of inspections for detecting the above-described defects in the panel to be inspected will be described based on a flowchart shown in FIG.

  First, the panel 2 to be inspected is held on the panel holding stage 11 by a transfer device or manually. At the same time, the lighting circuit 12 and the panel 2 to be inspected are connected via the contact portion 13 (first step S1).

  After the panel to be inspected 2 is installed on the panel holding stage 11 and the lighting circuit 12 and the panel to be inspected 2 are connected, the peripheral device control unit 15 sends a control signal to the lighting circuit 12 to drive the panel to be inspected 2. Start signal output. This is the second step S2.

  Next, the peripheral device control unit 15 sends a control signal to the transmitted illumination 14 to start irradiation with transmitted light. In addition, the intensity | strength of the said transmitted light is adjusted to intensity | strength suitable as a transmissive light source of a to-be-inspected panel. When the panel to be inspected 2 itself has a light source, the amount of light emitted from the light source of the panel to be inspected 2 is adjusted. This is a third step S3.

  Next, the peripheral device control unit 15 sends a control signal for causing the inspection unit 10 to start imaging. According to the control signal, the inspection unit 10 captures an image of one pixel row on the panel 2 to be inspected from the left eye direction by the line sensor camera 10a. This is a fourth step S4. At the same time, the inspection unit 10 images one pixel row adjacent to the pixel row from the right eye direction by the line sensor camera 10b. This is the fifth step S5.

  Next, it is determined whether the pixel row captured by the line sensor camera 10a is an image display pixel row or an image non-display is a pixel row. That is, a pixel column imaged from the left eye direction by the line sensor camera 10a is a pixel column that should emit light in the left eye direction (for example, among the pixel columns L0, L1,..., L7 shown in FIG. 3). It is determined whether any one pixel row). This is designated as a sixth step S6. At the same time, it is determined whether the pixel row captured by the line sensor camera 10b is an image display pixel row or an image non-display is a pixel row. That is, a pixel column captured from the right eye direction by the line sensor camera 10b is a pixel column that should emit light in the right eye direction (for example, among the pixel columns R0, R1,..., R7 shown in FIG. 3). It is determined whether any one pixel row). This is referred to as a seventh step S7.

  Note that the line sensor camera 10a and the line sensor camera 10b are arranged so as to capture the same one-dimensional display region, that is, adjacent pixel columns, and therefore the determination results are the same. The determination is made in the image processing device 16 based on the panel installation position signal output from the panel holding stage 11.

  In the sixth step S6 and the seventh step S7, the line sensor camera 10a and the line sensor camera 10b respectively capture the pixel columns of the display unit that should emit light in the direction in which the line sensor camera is arranged. In the eighth step S8 and the ninth step S9, the image processing device 16 compares the two images captured by the line sensor camera when it is determined that they are present (YES in S6 and S7). A luminance difference between pixels corresponding to the same display area is calculated, and first image data (difference image) is generated.

  Subsequent to the eighth step S8 and the ninth step S9, the image processing device 16 performs threshold processing on the image captured by the line sensor camera. This is designated as a tenth step S10 and an eleventh step S11. For example, if a uniform white signal is given to the panel to be inspected, a pixel having a luminance lower than the threshold value is detected as a luminance lowering portion. Based on the detection result, second image data in which high luminance is assigned to the defective pixel is generated.

  The series of processing from S8 to S11 corresponds to the inspection method described with reference to FIG. 4, and black spot defects in the panel 2 to be inspected are detected by the processing from S8 to S11.

  In the sixth step S6 and the seventh step S7, the line sensor camera 10a and the line sensor camera 10b respectively capture the pixel columns of the non-display portion where light should not be emitted in the direction in which the line sensor camera is disposed. If it is determined that the pixel line has been determined (NO in S6 and S7), the pixel column is inspected for a crosstalk defect as described with reference to FIG.

  That is, in the twelfth step S12 and the thirteenth step S13, the image processing device 16 compares the two images captured by the line sensor camera, and calculates the luminance difference between the pixels corresponding to the same display area. Then, third image data (difference image) is generated. Further, following S12 and S13, threshold processing is performed in the fourteenth step S14 and the fifteenth step S15. By the threshold processing, pixels having luminance exceeding the threshold are detected as crosstalk defective pixels. Based on the detection result, fourth image data in which a high pixel value is assigned to the defective pixel is generated.

  In the sixteenth step S16, the first image data to the fourth image data are synthesized. Specifically, for each display area, calculate the logical sum of the pixel values assigned to the corresponding pixels in the four image data, and generate the fifth image data in which the calculation result is assigned to the display area. It ’s fine.

  In S17, the detection result of the defective pixel or defective pixel row is output based on the fifth image data obtained in S16. That is, in the fifth image data, a pixel without a defect is represented by a low gray value, and a defective pixel is represented by a high gray value, so that a defective pixel position can be easily recognized.

  The series of processes from S1 to S17 is for executing an inspection for one pixel column of the panel 2 to be inspected. After the processing up to S17 is completed, the panel holding stage 11 moves the panel 2 to be inspected by one display area in a direction orthogonal to the one-dimensional display area imaged by the line sensor camera. Thereby, the pixel column imaged by the line sensor camera becomes a pixel column adjacent to the pixel column imaged last time. After the panel 2 to be inspected is moved as described above, the process returns to S4 and S5, and the steps from S4 to S17 are repeated for the pixel columns provided in the panel 2 to be inspected, whereby all the pixels of the panel 2 to be inspected. A check is performed on the column.

  In the above-described inspection flow, luminance difference calculation and threshold processing are performed for each pixel column, and the inspection is performed on all the pixel columns of the panel to be inspected by repeating this. However, the present invention is not limited to this. That is, for example, the image processing apparatus includes a recording unit, records image data captured by the line sensor camera for a plurality of pixel columns in the recording unit, and brightness for the image data for the plurality of pixel columns recorded in the recording unit. It is also possible to adopt a configuration in which difference calculation and threshold processing are performed.

  Further, in the inspection flow described above, the crosstalk inspection is performed following the point defect inspection, and the first to fourth image data are synthesized in the sixteenth step, and the seventeenth seventeenth is combined. In the process, an inspection result is output based on the synthesized image data. However, the present invention is not limited to this. That is, for example, following the point defect inspection (S8 to S11), the first image data and the second image data are combined, and a result regarding the point defect inspection is output based on the combined image data. Subsequently to the crosstalk inspection (S12 to S15), the third image data and the fourth image data are combined, and a result regarding the crosstalk inspection is output based on the combined image data. It is also possible.

  Next, a method for more accurately evaluating whether each pixel provided in the panel to be inspected correctly emits light in the light emission direction determined for each pixel will be described with reference to FIG. To do.

  As the first control signal, a uniform white signal as an image signal displayed in the left eye direction and a uniform black signal as an image signal displayed in the right eye direction are given to the panel 2 to be inspected. FIG. 7A shows how the panel to be inspected 2 to which the image signal is given is viewed from the front in a state where there is virtually no parallax. Further, a uniform black signal as an image signal to be displayed in the left eye direction and a uniform white signal as an image signal to be displayed in the right eye direction are given to the panel 2 to be inspected as the second control signal. FIG. 7B shows how the panel to be inspected 2 to which the image signal is given is viewed from the front in a state where there is virtually no parallax. In the panel 2 to be inspected, the light emission direction is not correctly controlled in some pixels as will be described later, but FIGS. 7A and 7B are virtual diagrams that do not define the observation direction. As such, the defective pixels are not shown in these figures. In addition, if the image signal displayed in the left eye direction in the first control signal and the image signal displayed in the right eye direction in the second control signal are signals that display a non-black uniform gradation image, An image signal having an arbitrary intermediate gradation may be used.

  The panel to be inspected 2 has a defect in the parallax generation device in the pixel column L2, the pixel column R2, and the pixel column R7, and is determined from the pixel column as shown in FIG. 7 (c) or FIG. 7 (d). Light is emitted in a direction different from the image display direction.

  FIG. 7E shows an image obtained by imaging the panel 2 to be inspected to which the first control signal is given by the line sensor camera 10a arranged in the left eye direction. Further, FIG. 7F shows an image obtained by capturing the panel 2 to be inspected to which the second control signal is given by the line sensor camera 10b arranged in the right eye direction. In the image of FIG. 7E, since the light emitted from the pixel row L2 is not accurately incident on the line sensor camera 10a, the luminance is detected low in the pixel row L2. Similarly, in the image of FIG. 7F, the luminance is detected low in the pixel column R2 and the pixel column R7.

  The difference image shown in FIG. 7G is obtained by taking the difference between the image shown in FIG. 7E and the image shown in FIG. 7F. If necessary, binarization is performed by threshold processing to detect a linear luminance lowering defect due to an abnormal emission direction in S1 and S7.

  Further, threshold processing is performed on the image shown in FIG. 7E obtained by imaging the panel 2 to be inspected to which the first control signal is given from the left eye direction by the line sensor camera 10a. That is, pixel rows R0, R1,..., R7 that should emit light in a direction different from the direction in which the line sensor camera captures are set in advance in the required luminance profile (FIG. 7 (h)). A pixel having a luminance lower than the threshold value Th2 is detected as a luminance lowering defect.

  Similarly, threshold processing is performed on the image shown in FIG. 7F obtained by imaging the panel 2 to be inspected to which the second control signal is given from the right eye direction by the line sensor camera 10b. That is, the luminance profile is obtained for the pixel rows L0, L1,..., L7 that should emit light in a direction different from the direction in which the line sensor camera images (FIG. 7 (i)). And the pixel which has the brightness | luminance which falls below threshold value Th2 set beforehand with respect to the said brightness | luminance profile is detected as a brightness fall defect.

  FIG. 7J shows image data generated by assigning high luminance to the pixel in which the luminance reduction defect is detected by the threshold processing.

  In the black spot defect inspection by the above-described method, the drive signal given to the panel to be inspected 2 displays a uniform white image in one image display direction and displays a black image in the other image display directions. A signal for driving the inspection panel 2 was used. For this reason, after eliminating the influence of the light emitted from the pixels from which light should be emitted in directions other than the image display direction in which the white image is displayed, the emission of light emitted in the image display direction in which the white image is displayed Only the direction control state can be evaluated with high accuracy.

  Next, a method for evaluating the crosstalk defect in each display region of the panel to be inspected with higher accuracy will be described with reference to FIG.

  The panel 2 to be inspected is supplied with a uniform black signal as an image signal displayed in the left eye direction and a uniform white signal as an image signal displayed in the right eye direction as control signals. FIG. 8A shows how the panel to be inspected 2 to which the image signal is given is viewed from the front in a state where there is virtually no parallax. In the panel 2 to be inspected, there is a crosstalk defect in some pixels as will be described later, but FIG. 8A is a virtual diagram that does not define the observation direction. Is not shown. The image signal displayed in the right eye direction may be an image signal having an arbitrary intermediate gradation as long as it is a signal for displaying an image having a uniform gradation that is not black. However, in order to detect with high accuracy a crosstalk defect that affects an image displayed in the right eye direction and an image displayed in the left eye direction, it is preferable to display a white image in the right eye direction as described above.

  The panel to be inspected 2 has a defect in the parallax generation device in the pixel column R0, the pixel column R1, and the pixel column R7. As shown in FIG. 8B, the image display direction determined from the pixel column is Light is emitted in different directions.

  FIG. 8C shows an image obtained by imaging the panel to be inspected 2 to which the control signal is given from the left eye direction by the line sensor camera 10a. In FIG. 8 (c), the pixel row R0, the pixel row R1, and the pixel row R7 have an intermediate gradation because the light emitted from the pixel row is correctly controlled in the right eye direction to be emitted. This is because the light emitted from the pixel row enters the line sensor camera 10a that images the panel 2 to be inspected from the left eye direction.

  Threshold processing is performed on the image shown in FIG. 8C in which the panel 2 to be inspected given the control signal is imaged from the left eye direction by the line sensor camera 10a. That is, pixel rows R0, R1,..., R7 that should emit light in a direction different from the direction in which the line sensor camera captures are set in advance in the required luminance profile (FIG. 8 (e)). Pixels having a luminance below the threshold value are detected.

  FIG. 8F shows image data generated by assigning high luminance to the pixel in which the luminance reduction defect is detected by the threshold processing. Here, P1, P2,..., P7 correspond to differences between image display pixel columns, and Q1, Q2,..., Q7 correspond to differences between image non-display pixel columns.

  In the crosstalk defect inspection by the above-described method, one image display direction to be inspected is determined, a uniform black image is displayed in the image display direction, and a white image is displayed in the other image display directions. . For this reason, after eliminating the influence of the light to be emitted in the image display direction to be inspected, the light to be emitted in a different image display direction is displayed on the image displayed in the display direction to be inspected. It is possible to evaluate the influence on the object with high accuracy.

  In the crosstalk defect inspection by the above-described method, the drive signal given to the panel 2 to be inspected displays a uniform black image in one image display direction and a uniform white image in the other image display directions. It was set as the signal which drives the to-be-inspected panel 2 so that it might display. For this reason, it becomes possible to evaluate with high accuracy the leakage of light that should be emitted in the other direction in the image display direction in which the black image is displayed, that is, the crosstalk defect.

  When inspecting the image display panel that displays images in the two directions of the left eye direction and the right eye direction exemplified in this embodiment, the light emission state in the right eye direction is inspected by the method shown in FIG. Therefore, the drive signal given to the panel to be inspected 2 and the drive signal given to the panel to be inspected for inspecting a crosstalk defect in which light to be emitted in the right eye direction leaks in the left eye direction by the method shown in FIG. Match. Therefore, a part of the inspection shown in FIG. 7 and the inspection shown in FIG. 8 can be executed simultaneously.

  In the present embodiment, the case where the inspection apparatus and the inspection method according to the present invention are applied to a monochrome transmissive image display panel that independently displays images having two different parallaxes by the parallax generation device has been described. However, the present invention is not necessarily limited to this. For example, the panel to be inspected may be an image display panel that displays a color image. For example, in the case of an image display panel that displays color images in red (R), green (G), and blue (B), the above inspection can be executed for each color.

  The panel to be inspected may be an image display panel that realizes image display in a plurality of image display directions by means other than the parallax generation device. By appropriately adjusting the area that multiple line sensors capture simultaneously in accordance with the image display method of the panel to be inspected, the defect inspection of the multiple image display panel by means other than the parallax generation device is realized by the same method as above it can.

  Further, the image display direction of the panel to be inspected is not limited to the two directions of the right eye direction and the left eye direction, and may further include three or more display methods. In this case, the inspection unit 10 may have the same number of line sensor cameras as the number of image display directions of the panel to be inspected, and the line sensor cameras may be arranged so as to capture the same one-dimensional area.

  Further, the panel to be inspected may be a self-luminous image display panel provided with a transmissive light source in advance. In this case, it is possible to omit transmitted illumination from the inspection apparatus.

  The line sensor camera 10, the panel holding stage 11, and the lighting circuit 12 in the image display panel inspection apparatus 1 are controlled, and each unit and each processing step of the image processing apparatus 16 are performed by a calculation means such as a CPU, It can be realized by executing a program stored in a storage means such as (Read Only Memory) or RAM and controlling input means such as a keyboard, output means such as a display, or communication means such as an interface circuit. . Therefore, the computer having these means can realize various functions and various processes of the inspection apparatus of the present embodiment simply by reading the recording medium on which the program is recorded and executing the program. In addition, by recording the program on a removable recording medium, the various functions and various processes described above can be realized on an arbitrary computer.

  As this recording medium, a program medium such as a memory (not shown) such as a ROM may be used for processing by the microcomputer, or a program reader is provided as an external storage device (not shown). It may be a program medium that can be read by inserting a recording medium therein.

  In any case, the stored program is preferably configured to be accessed and executed by the microprocessor. Furthermore, it is preferable that the program is read out, and the read program is downloaded to a program storage area of the microcomputer and the program is executed. It is assumed that this download program is stored in advance in the main unit.

  The program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as a flexible disk or a hard disk, or a disk such as a CD / MO / MD / DVD. Fixed disk, IC card (including memory card), etc., or semiconductor ROM such as mask ROM, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), flash ROM, etc. In particular, there are recording media that carry programs.

  In addition, if the system configuration is capable of connecting to a communication network including the Internet, the recording medium is preferably a recording medium that fluidly carries the program so as to download the program from the communication network.

  Further, when the program is downloaded from the communication network as described above, it is preferable that the download program is stored in the main device in advance or installed from another recording medium.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of the present invention and is a configuration diagram illustrating a configuration of an inspection apparatus. FIG. 2A is an explanatory diagram for explaining the outline of an image display panel to be inspected by the inspection method or inspection apparatus according to the embodiment of the present invention. FIG. 2B shows the arrangement of the line sensor camera (imaging means) in the inspection apparatus according to the embodiment of the present invention with respect to the panel to be inspected, or the imaging process included in the inspection method according to the embodiment of the present invention. It is explanatory drawing which shows the imaging direction in. FIG. 2C shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the left eye direction (first image display direction). FIG. 2D shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the right eye direction (second image display direction). FIG. 2E is an explanatory view showing how the panel to be inspected is visually observed from the left eye direction. FIG. 2F is an explanatory diagram for explaining how the panel to be inspected is visually observed from the right eye direction. FIG. 3A is an explanatory view showing the state of the image display panel to be inspected by the inspection method or inspection apparatus according to the embodiment of the present invention, and shows the case where the panel to be inspected has no defect. Is. FIG. 3B shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the left eye direction (first image display direction). FIG. 3C shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the right eye direction (second image display direction). FIG. 3D shows an image taken from the left eye direction and a difference image taken from the right eye direction. FIG. 4A is an explanatory diagram for explaining the state of the image display panel to be inspected by the inspection method or inspection apparatus according to the embodiment of the present invention, in a partial region of the panel to be inspected. The case where there is a black spot defect is shown. FIG. 4B shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the left eye direction (first image display direction). FIG. 4C shows an embodiment of the present invention, and is an image obtained by imaging the panel to be inspected from the right eye direction (second image display direction). FIG. 4D shows an image captured from the left eye direction and a difference image captured from the right eye direction. FIG. 4E is a graph showing the luminance profile of each pixel column in the image data shown in FIG. 4B, and particularly a graph showing the luminance profile for the pixel column including a defect. FIG. 4F is a graph showing the luminance profile of each pixel column in the image data shown in FIG. 4C, and particularly a graph showing the luminance profile for the pixel column including a defect. FIG. 4G shows the result of detecting defective pixels of the non-inspection panel obtained by combining the difference image shown in FIG. 4D and the luminance profile shown in FIGS. 4E and 4F. Is image data. FIG. 5A is an explanatory diagram for explaining the state of the image display panel to be inspected by the inspection method or inspection apparatus according to the embodiment of the present invention, in a partial region of the panel to be inspected. This shows a case where there is a crosstalk defect. FIG. 5B is a cross-sectional view of the panel to be inspected, and shows a light emission state in each pixel column. FIG. 5C shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the left eye direction (first image display direction). FIG. 5D shows an embodiment of the present invention, which is an image obtained by imaging the panel to be inspected from the right eye direction (second image display direction). FIG. 5E shows an image captured from the left eye direction and a difference image captured from the right eye direction. FIG. 5F is a graph showing the luminance profile of each pixel column in the image data shown in FIG. FIG. 5G is a graph showing the luminance profile of each pixel column in the image data shown in FIG. FIG. 5H shows a result of detecting defective pixels of the non-inspection panel obtained by combining the difference image shown in FIG. 5E and the luminance profile shown in FIGS. 5F and 5G. Is image data. It is a flowchart for demonstrating the test | inspection method which concerns on embodiment of this invention, Comprising: A series of processes which comprise the said test | inspection method. FIG. 7A is an explanatory diagram for explaining the state of the image display panel to be inspected by the inspection method or inspection apparatus according to the embodiment of the present invention. This shows a case where a drive signal is given to the panel to be inspected so as to display a black image uniform in the direction. FIG. 7B is an explanatory diagram for explaining the state of the image display panel to be inspected by the inspection method or the inspection apparatus according to the embodiment of the present invention. This shows a case where a drive signal is given to the panel to be inspected so as to display a white image uniform in the direction. FIG. 7C is a cross-sectional view of the panel to be inspected shown in FIG. 7A, and shows a light emission state in each pixel column. FIG. 7D is a cross-sectional view of the panel to be inspected shown in FIG. 7B, and shows a light emission state in each pixel column. FIG. 7E is an image obtained by imaging the panel to be inspected shown in FIG. 7A from the left eye direction (first image display direction). FIG. 7F is an image obtained by imaging the panel to be inspected shown in FIG. 7B from the right eye direction (second image display direction). FIG. 7G shows an image taken from the left eye direction and a difference image taken from the right eye direction. FIG. 7H is a graph showing the luminance profile of each pixel column in the image data shown in FIG. FIG. 7 (i) is a graph showing the luminance profile of each pixel column in the image data shown in FIG. 7 (f). FIG. 7 (j) shows the defective pixel detection result of the non-inspection panel obtained by combining the difference image shown in FIG. 7 (g) and the luminance profile shown in FIGS. 7 (h) and 7 (i). Is image data. FIG. 8A is an explanatory diagram for explaining the state of the image display panel to be inspected by the inspection method or the inspection apparatus according to the embodiment of the present invention. This shows a case where a drive signal is given to the panel to be inspected so as to display a white image uniform in the direction. FIG. 8B is a cross-sectional view of the panel to be inspected shown in FIG. 8A, and shows a light emission state in each pixel column. FIG. 8C is an image obtained by imaging the panel to be inspected shown in FIG. 8A from the left eye direction (first image display direction). FIG. 8D is a graph showing the luminance profile of each pixel column in the image data shown in FIG. FIG. 8E is image data showing a defective pixel detection result of the non-inspection panel obtained from the luminance profile of FIG. The prior art shows an inspection unit comprising a condensing lens and a two-dimensional sensor array in which a plurality of sensor elements are two-dimensionally arranged, and the condensing lens is displayed on a panel to be inspected. It is explanatory drawing of the image display panel test | inspection apparatus arrange | positioned so that a surface may correspond to a front focus position. It is a block diagram of the inspection apparatus which shows a prior art and is a modification of the inspection apparatus shown in FIG. 8, and is provided with a pinhole. 1 shows a conventional technique, comprising a condensing lens and a two-dimensional sensor array in which a plurality of sensor elements are two-dimensionally arranged, and the condensing lens is arranged on the panel to be inspected on the two-dimensional sensor array. It is explanatory drawing of the image display panel test | inspection apparatus arrange | positioned so that a real image may form.

Explanation of symbols

1 Defect inspection equipment (inspection equipment)
2 Panel to be inspected (image display panel)
10 Line sensor camera (image data acquisition unit)
11 Panel holding stage (panel holding part)
12 Lighting circuit (signal supply unit)
15 Peripheral device controller (control means)
16 Image processing device (defect detection unit)

Claims (23)

An inspection method for detecting defects in an image display panel that displays images independent of two or more different image display directions,
An image data acquisition process for acquiring image data captured from each image display direction for an image display panel to which an inspection display signal is given;
And a defect detection step of detecting a defect of the image display panel based on comparison of image data captured from each image display direction.   In the image data acquisition step, the imaging device that detects the luminance of the one-dimensional region on the image display panel is moved relative to the image display panel, and the entire surface of the image display panel is imaged. 2. The inspection method according to claim 1, wherein image data is acquired. In the image data acquisition step, as an inspection display signal, a signal for displaying the same image in all image display directions of the image display panel is given,
In the defect detection step, a difference between corresponding display areas or non-display areas corresponding to each image data is taken, and it is determined that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. The inspection method according to claim 1. In the image data acquisition step, as a display signal for inspection, a signal for displaying an image having a uniform gradation that is not black with respect to all image display directions of the image display panel is provided.
2. The inspection according to claim 1, wherein in the defect detection step, a pixel in which a defect is generated is determined by comparing a detection value of each pixel with a predetermined threshold for each image data. Method. In the image data acquisition step, as a display signal for inspection, a signal for causing the pixels in the display area to display an image with a uniform gradation that is not black, and a signal for performing black display to the pixels in the non-display area are given,
In the defect detection step, a difference between corresponding display areas or non-display areas corresponding to each image data is taken, and it is determined that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. The inspection method according to claim 1. In the image data acquisition step, as a display signal for inspection, a signal for causing the pixels in the display area to display an image with a uniform gradation that is not black, and a signal for performing black display to the pixels in the non-display area are given,
2. The inspection according to claim 1, wherein in the defect detection step, a pixel in which a defect is generated is determined by comparing a detection value of each pixel with a predetermined threshold for each image data. Method. In the image data acquisition step, as a display signal for inspection, a signal for causing a pixel in the display area to perform black display and a pixel in the non-display area to perform non-black uniform gradation image display is provided.
2. The inspection according to claim 1, wherein in the defect detection step, a pixel in which a defect is generated is determined by comparing a detection value of each pixel with a predetermined threshold for each image data. Method. An inspection apparatus for detecting defects in an image display panel that displays images independent of two or more different image display directions,
A panel holding unit for holding the image display panel;
A signal supply unit for supplying an inspection display signal to the image display panel;
An inspection apparatus, comprising: an image data acquisition unit that acquires image data captured from each image display direction with respect to an image display panel to which an inspection display signal is given. An inspection apparatus for detecting defects in an image display panel that displays images independent of two or more different image display directions,
A panel holding unit for holding the image display panel;
A signal supply unit for supplying an inspection display signal to the image display panel held by the panel holding unit;
An image data acquisition unit that acquires image data captured from each image display direction for an image display panel to which an inspection display signal is given from the signal supply unit;
An inspection apparatus comprising: a defect detection unit configured to detect a defect of the image display panel based on comparison of image data acquired from each image display direction acquired by the image data acquisition unit. The image data acquisition unit is an imaging device that detects the luminance of a one-dimensional area on the image display panel,
The inspection apparatus according to claim 8 or 9, wherein the entire surface of the image display panel is imaged while moving a relative position of the image display panel with respect to the imaging apparatus. The signal supply unit gives a signal for displaying the same image for all image display directions of the image display panel as a display signal for inspection,
The defect detection unit calculates a difference between corresponding display areas or non-display areas corresponding to each image data, and determines that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. The inspection apparatus according to claim 9. The signal supply unit gives a signal for displaying an image with a uniform gradation that is not black for all image display directions of the image display panel as an inspection display signal,
The inspection according to claim 9, wherein the defect detection unit determines, for each image data, a pixel in which a defect has occurred by comparing a detection value of each pixel with a predetermined threshold value. apparatus. The signal supply unit gives a signal for causing the pixels in the display region to display an image with a uniform gradation that is not black, and the pixels in the non-display region to perform black display as a display signal for inspection,
The defect detection unit calculates a difference between corresponding display areas or non-display areas corresponding to each image data, and determines that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. The inspection apparatus according to claim 9. The signal supply unit gives a signal for causing the pixels in the display region to display an image with a uniform gradation that is not black, and the pixels in the non-display region to perform black display as a display signal for inspection,
The inspection according to claim 9, wherein the defect detection unit determines, for each image data, a pixel in which a defect has occurred by comparing a detection value of each pixel with a predetermined threshold value. apparatus. The signal supply unit provides a signal for causing the pixels in the display area to perform black display and the pixels in the non-display area to perform non-black uniform gradation image display as a display signal for inspection,
The inspection according to claim 9, wherein the defect detection unit determines, for each image data, a pixel in which a defect has occurred by comparing a detection value of each pixel with a predetermined threshold value. apparatus. A control program for causing the inspection apparatus according to claim 10 to detect a defect of the image display panel,
A computer connected to the panel holding unit and the imaging device;
The panel holding unit and the image data acquisition unit are controlled so that the image data acquisition unit images the entire surface of the image display panel while moving the relative position between the image data acquisition unit and the image display panel. A control program for functioning as a control means. A defect detection program for causing the inspection apparatus according to claim 8 to detect a defect of the image display panel,
A computer connected to the signal supply unit and the image data acquisition unit,
Signal supply unit control means for controlling the signal supply unit so as to give a signal for displaying the same image in all image display directions to the image display panel held by the panel holding unit;
Further, the difference between display areas or non-display areas in the image data acquired by the image data acquisition unit is taken, and it is determined that a defect has occurred in a pixel whose difference value is larger than a predetermined reference value. A defect detection program for functioning as defect detection means. A defect detection program for causing the inspection apparatus according to claim 8 to detect a defect of the image display panel,
A computer connected to the signal supply unit and the image data acquisition unit,
Signal supply unit control means for controlling the signal supply unit so as to give the image display panel held by the panel holding unit a signal for displaying an image having a uniform gradation that is not black in all image display directions. ,
And, for each image data acquired by the image data acquisition unit, to function as a defect detection means for judging a pixel in which a defect has occurred by comparing the detection value of each pixel with a predetermined threshold value Defect detection program. A defect detection program for causing the inspection apparatus according to claim 8 to detect a defect of the image display panel,
A computer connected to the signal supply unit and the image data acquisition unit,
The image display panel held in the panel holding unit is configured to give a signal for performing non-black uniform gradation image display on the pixels in the display region and black display on the pixels in the non-display region. A signal supply unit control means for controlling the signal supply unit;
In addition, a difference between display areas or non-display areas corresponding to each image data in the image data acquired by the image data acquisition unit is obtained, and a defect is detected with respect to a pixel whose difference value is larger than a predetermined reference value. A defect detection program for functioning as a defect detection means for determining that an error has occurred. A defect detection program for causing the inspection apparatus according to claim 8 to detect a defect of the image display panel,
A computer connected to the signal supply unit and the image data acquisition unit,
The image display panel held in the panel holding unit is configured to give a signal for performing non-black uniform gradation image display on the pixels in the display region and black display on the pixels in the non-display region. A signal supply unit control means for controlling the signal supply unit;
And, for each image data acquired by the image data acquisition unit, to function as a defect detection means for judging a pixel in which a defect has occurred by comparing the detection value of each pixel with a predetermined threshold value Defect detection program. A defect detection program for causing the inspection apparatus according to claim 8 to detect a defect of the image display panel,
A computer connected to the signal supply unit and the image data acquisition unit,
The image display panel held in the panel holding unit is configured to give a signal for causing the pixels in the display area to perform black display and the pixels in the non-display area to perform non-black uniform gradation image display. A signal supply unit control means for controlling the signal supply unit;
And, for each image data acquired by the image data acquisition unit, to function as a defect detection means for judging a pixel in which a defect has occurred by comparing the detection value of each pixel with a predetermined threshold value Defect detection program.   The computer-readable recording medium which recorded the control program of Claim 16.   A computer-readable recording medium on which the defect detection program according to any one of claims 17 to 21 is recorded.

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