JP2011017953A - Apparatus and method for inspecting luminance of liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for inspecting the luminance, wherein the apparatus can inspect the luminance of the liquid crystal panel, even immediately after starting lighting of the backlight.SOLUTION: The apparatus includes an illumination means, an imaging means, a lamp image data-generating means and a means for generating luminance data of a screen for irregularity correction. In the illumination means, the luminance is uniform in a light-emitting surface, and the light amount is stabilized, immediately after the lighting. The imaging means captures the image of the light-emitting surface of the backlight unit and the image of a display screen in the liquid crystal display panel, in which an illumination means is arranged on the backside thereof. The lamp image data-generating means generates a lamp image data, based on lamp luminance data obtained by capturing the image of the light-emitting surface of the backlight unit, when the light amount of the lamp is stabilized. The means for generating luminance data of the screen for irregularity correction has the illumination means, arranged on a backside thereof and generates the luminance data of the screen for irregularity correction. The luminance data of the screen for irregularity correction is obtained, by adding lamp image data to the screen luminance data, obtained by capturing the image of the display screen of the liquid crystal display panel on which an image for inspection is displayed.

Description

  The present invention relates to an apparatus and a method for inspecting the luminance of a display screen of a liquid crystal display panel that performs display by controlling transmission of light from a backlight provided with a number of lamps.

  In recent years, liquid crystal display panels have been widely used as display units for home appliances such as computers and televisions. In general, a liquid crystal display panel has a configuration in which a pair of substrates, which are a thin film transistor (TFT) array substrate and a color filter (CF) substrate, are arranged in parallel to each other at a predetermined interval, and liquid crystal is filled between the substrates. There is no. A plurality of pixel electrodes are formed in a matrix on the TFT array substrate, and a common electrode is formed on almost the entire surface of the CF substrate, and the orientation of the liquid crystal can be controlled by changing the voltage applied between these electrodes. Can be done.

  FIG. 7 is a diagram schematically showing the structure of a liquid crystal display device generally used in the past. As illustrated, the liquid crystal display device 50 includes a bezel 51, a liquid crystal display panel 52, and a backlight 53. The bezel 51 is a member that becomes a frame of the liquid crystal display panel 52, and holds the periphery of the liquid crystal display panel 52. The liquid crystal display panel 52 is obtained by bonding two pieces of glass and sealing the liquid crystal therebetween.

  The backlight 53 includes a frame 54, optical sheets 55 to 57, a diffusion plate 58, a fluorescent lamp 59, a reflection sheet 60, and a backlight chassis 61. The frame 54 has a frame shape and is a member for fixing to the backlight chassis 61 in a state where the optical sheets 55 to 57 and the diffusion plate 58 are laminated.

  The optical sheets 55 to 57 and the diffusion plate 58 are optical members that adjust the characteristics of light incident on the liquid crystal display panel 52 from the fluorescent lamp 59. In this case, the optical sheets 55, 56, and 57 are formed by laminating three sheets, for example, a diffusion sheet having a sheet thickness of 0.1 to 0.3 mm, a lens sheet, and a deflection selective reflection sheet. Further, the thickness of the diffusion plate 58 is a resin plate of about 2 mm, and is disposed below the optical sheets 55 to 57. Further, the white reflection sheet 60 laid under the fluorescent lamp 59 is a member for reflecting the light emitted from the fluorescent lamp 59 to the liquid crystal display panel 52 side.

  The diffuser plate 58 and the optical sheets 55 to 57 are disposed above the fluorescent lamp 59 and the reflection sheet 60 is disposed below the fluorescent lamp 59, whereby the shadow (lamp image) of the fluorescent lamp 59 is formed on the light emitting surface of the backlight 53. ) Can be prevented, and the luminance within the light emitting surface can be made uniform.

  The backlight chassis 61 has a shallow box shape, and a plurality of fluorescent lamps 59 can be accommodated in parallel with each other. The light from the plurality of fluorescent lamps 59 arranged in the backlight chassis 61 is transmitted through the diffusion plate 58, the optical sheets 55 to 57, and the liquid crystal display panel 52 together with the light reflected by the reflection sheet 60. It is visible to the observer side.

  Usually, in order to operate such a liquid crystal display device 50 normally, the liquid crystal display panel 52 is actually turned on to check the operation before assembling the display device 50 in advance, and there is no defect such as uneven brightness. It is necessary to check whether or not.

  Such brightness inspection items of the liquid crystal display panel include point defects and line defects in which one or several pixels of the liquid crystal display panel 52 become defects or bright spots, and uneven brightness in a wide area of the display screen. There is brightness unevenness.

  Conventionally, these items have been inspected mainly by visual sensory evaluation by an operator, but in recent years, luminance inspection using an imaging means such as a CCD camera has been proposed.

  In such a luminance inspection of the liquid crystal display panel 52, an inspection backlight having the same configuration as the backlight 53 included in the liquid crystal display device 50 as a product is arranged on the back surface of the liquid crystal display panel 52 to be inspected, and light is emitted. In addition, the liquid crystal display panel 52 is driven to display an inspection image, and this is imaged by a CCD camera, whereby the luminance of the liquid crystal display panel is inspected.

  FIG. 8 is a diagram showing a schematic configuration of a conventionally used luminance inspection apparatus for a liquid crystal display panel. The brightness inspection device 70 includes a control device 71 and a CCD camera 72 that captures an image of the liquid crystal display panel 52 to be inspected. Configured to inspect. In addition, the luminance inspection apparatus 70 includes an inspection backlight 73 that is provided on the back side of the liquid crystal display panel 52 and irradiates the liquid crystal display panel 52 with predetermined illumination light.

  Further, in the luminance inspection apparatus 70, a monitor 74 is connected to the control device 71, and the imaging result of the CCD camera 72 is displayed on the monitor 74. The control device 71 is configured to be connectable to the liquid crystal display panel 52 and the inspection backlight 73, and can perform inspection while performing drive control of the liquid crystal display panel 52 and lighting control of the backlight 73. . The control device 71 outputs a driving inspection signal to the liquid crystal display panel 52 to perform a luminance inspection in a state where a predetermined image for inspection is displayed. The drive signal correction data to be driven can be generated.

  In such a brightness inspection apparatus 70, the liquid crystal display panel 52 is driven so that the brightness of the entire display screen of the liquid crystal display panel 52 is uniform, that is, the brightness unevenness is eliminated, based on the imaging result of the CCD camera 72. The correction data of the drive signal to be generated is generated for each pixel.

  The inspection backlight 73 is provided with a diffusing plate and a reflection sheet so that the luminance on the light emitting surface is uniform as in the case of the backlight 53 described above, but the place where the fluorescent lamp 73a is arranged is still bright. A slight luminance difference occurs between the peripheral portion and the fluorescent lamp 73a, and illumination unevenness (lamp image) 81 as shown in FIG. 9A occurs. This illumination unevenness 81 is a brightness unevenness unique to the backlight.

  On the other hand, the panel unevenness 82 that occurs due to reasons such as non-uniformity in the thickness of the liquid crystal as shown in FIG. Therefore, it is necessary to generate correction data of a drive signal for driving the liquid crystal display panel 52 so that the illumination unevenness 81 and the panel unevenness 82 disappear in the state shown in FIG. 9B. In addition, the following patent document is mentioned as a prior art document relevant to this invention.

Japanese Patent Application Laid-Open No. 6-118024

  In the above-mentioned luminance inspection of the liquid crystal display panel, since a fluorescent lamp such as a cold cathode fluorescent tube that requires time to turn on and off is used as an inspection backlight for displaying an image on the liquid crystal display panel, it always lights up. It was necessary to let them. That is, since it takes time to turn on and off the fluorescent lamp, if the fluorescent lamp is turned on and off every time the liquid crystal display panel subjected to the luminance inspection is replaced, a quick luminance inspection cannot be performed. For this reason, it is necessary to always turn on the backlight (fluorescent lamp) during the luminance inspection.

  However, since the fluorescent lamp normally requires 30 minutes to 60 minutes from the start of lighting until the light quantity is stabilized, the illumination unevenness 81 is larger than that in the case of FIG. 9A as shown in FIG. Since it appears greatly and remarkably and an accurate luminance inspection of the liquid crystal display panel cannot be performed, there is a problem in the rapidity of the initial luminance inspection.

  Therefore, the problem to be solved by the present invention is to provide a luminance inspection apparatus and a luminance inspection method capable of improving the quickness of the luminance inspection of the liquid crystal display panel.

  In order to solve the above-mentioned problems, the present invention is an apparatus for inspecting the luminance of a display screen of a liquid crystal display panel for controlling the transmission of light from a backlight provided with a large number of lamps, and the luminance is Illumination means that is uniform and uniform within the light emitting surface and whose light quantity is stabilized immediately after lighting, and imaging means that images the light emitting surface of the backlight alone and the display screen of the liquid crystal display panel on which the illumination means is arranged on the back surface And lamp image data generating means for generating lamp image data based on lamp luminance data obtained by imaging the light emitting surface of the backlight unit when the light quantity of the lamp is stable, and the illumination means on the back surface The lamp image is displayed on the screen brightness data obtained by imaging the display screen of the liquid crystal display panel on which the inspection image is displayed. Jideta is to summarized in that and a non-uniformity correction screen brightness data generation means for generating uniformity correction screen luminance data consideration is.

  In this case, it is preferable to further include a correction data generation unit that generates correction data of a drive signal for driving the liquid crystal display panel based on the unevenness correction screen luminance data. Further, it is preferable that the illumination unit includes a plurality of light emitting diodes arranged on the same plane. Further, the lamp may be a fluorescent lamp such as a cold cathode fluorescent tube. The imaging means may be a digital camera having a CCD.

  Further, in order to solve the above problems, the present invention is a method for inspecting the luminance of a display screen of a liquid crystal display panel that performs display by controlling transmission of light from a backlight provided with a number of lamps, A step of acquiring lamp luminance data of a light emitting surface of the backlight unit when the light quantity of the lamp is stabilized by an imaging unit; a step of generating lamp image data based on the lamp luminance data; In the liquid crystal display panel in which the inspection image is displayed on the display screen on the liquid crystal display panel disposed on the back surface with illumination means that is uniform and uniform and the amount of light is stabilized immediately after lighting, A step of acquiring screen brightness data of the display screen by an imaging means, and generating screen brightness data for unevenness correction in which the lamp image data is added to the screen brightness data; It is an gist further comprising the step of.

  In this case, it is preferable to further include a step of generating correction data of a drive signal for driving the liquid crystal display panel based on the unevenness correction screen luminance data. Further, it is preferable that the illumination unit includes a plurality of light emitting diodes arranged on the same plane. Further, the lamp may be a fluorescent lamp such as a cold cathode fluorescent tube. The imaging means may be a digital camera having a CCD.

  According to the brightness inspection apparatus and the brightness inspection method of the liquid crystal display panel according to the present invention having the above-described configuration, based on the lamp brightness data obtained by imaging the light emitting surface of the backlight unit when the light quantity of the lamp is stable. The lamp image data (illumination unevenness data) is generated in advance, and the luminance of the LED backlight or the like in which a large number of light emitting diodes (LEDs) are arranged on the same plane is uniform and uniform in the light emitting surface immediately after lighting. Lamp image data (illumination unevenness data) is added to screen brightness data (panel unevenness data) obtained by imaging the display screen of a liquid crystal display panel on which an illumination means with stable light quantity is arranged on the back and an inspection image is displayed. LCD screen panel with uneven brightness correction screen brightness data, that is, a backlight with stable lamp light intensity It is possible to generate the equivalent of a captured image data when an image.

  In other words, the illumination unevenness unique to the backlight is generated by imaging the light emitting surface of the single backlight unit in a state where the lamp light quantity is stabilized in advance, thereby generating lamp image data (illumination unevenness data). As for the panel unevenness, the screen brightness obtained by imaging a liquid crystal display panel with an illumination means such as an LED backlight whose brightness is uniform within the light emitting surface and the light quantity is stable immediately after lighting, that is, an illumination means with almost no illumination unevenness is arranged on the back As well as acquiring data (panel unevenness data), this screen brightness data (panel unevenness data) and lamp image data (illumination unevenness data) are added to the unevenness correction screen brightness data, that is, a backlight with stable lamp light intensity. The image data corresponding to the image of the liquid crystal display panel is generated. It becomes possible.

  Thereby, the brightness inspection of the liquid crystal display panel can be performed without waiting until the light quantity of the backlight becomes stable as in the conventional case, and the rapidity at the initial stage of the brightness inspection is improved.

It is the figure which showed schematic structure of the brightness inspection apparatus of the liquid crystal display panel which concerns on one Embodiment of this invention. It is the figure which showed the state which the brightness inspection apparatus of FIG. 1 images the light emission surface of a backlight single-piece | unit. It is the figure which showed schematic structure of the illumination means with which the brightness | luminance inspection apparatus of FIG. 1 is provided. It is an image figure of the lamp image data obtained from the imaging data of the light emission surface of the backlight single unit with which the light quantity was stabilized. (A) is an image diagram of screen luminance data which is imaging data of a display screen of a liquid crystal display panel with illumination means arranged on the back surface, and (b) is a result of adding the lamp image data of FIG. 4 to the screen luminance data of (a). It is an image figure of the screen brightness data for unevenness correction corrected in this way. It is an image figure of the display screen of the liquid crystal display panel after correct | amending so that brightness nonuniformity may be eliminated. It is the figure which showed schematic structure of the liquid crystal display device. It is the figure which showed schematic structure of the brightness inspection apparatus of the liquid crystal display panel used conventionally. (A) is the image figure of the imaging data of a liquid crystal display panel, (b) is an image figure of the display screen of a liquid crystal display panel after correcting so that a brightness nonuniformity may be eliminated. It is an image figure of the imaging data of the display screen of the liquid crystal display panel before the light quantity of a backlight is stabilized.

  Hereinafter, embodiments of a luminance inspection apparatus and a luminance inspection method for a liquid crystal display panel according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the luminance inspection apparatus 1 includes a control device 2 and a CCD camera 3 as an imaging unit that performs an imaging operation on the liquid crystal display panel 22 to be inspected. Using the result, the luminance of each of the plurality of pixels included in the liquid crystal display panel 22 is inspected. In addition, the luminance inspection apparatus 1 includes inspection illumination means 4 that is provided on the back side of the liquid crystal display panel 22 and irradiates the liquid crystal display panel 22 with predetermined illumination light. Further, as shown in FIG. 2, the luminance inspection apparatus 1 includes an inspection backlight 8 used for acquiring lamp image data (illumination unevenness data) described later.

  Further, in the luminance inspection apparatus 1, the monitor 9 is connected to the control device 2, and the imaging result of the CCD camera 3 is displayed on the monitor 9. Further, in the brightness inspection apparatus 1, for example, an operation instruction from an operator can be input using a touch panel function provided to the monitor 9, and an inspection process for inspecting the brightness of the liquid crystal display panel 22 can be started. The operator's instruction such as stop is input, and the luminance inspection process of the liquid crystal display panel 22 is performed according to the input instruction.

  A microcomputer is used for the control device 2, and the control device 2 is configured to perform drive control of each part of the luminance inspection device 1. Further, the control device 2 is configured to be connectable to the liquid crystal display panel 22, and can perform inspection while performing drive control of the liquid crystal display panel 22. Therefore, the control device 2 outputs a driving inspection signal to the liquid crystal display panel 22, thereby performing a luminance inspection in a state where a predetermined image for inspection is displayed, and further correcting in pixel units based on the inspection result. It is configured to be able to generate data.

  The control device 2 includes an imaging control unit 10, a signal control unit 11, an illumination unit control unit 12, a backlight control unit 13, a correction data generation unit 14, and a data input unit that are functionally provided in a CPU or MPU of the microcomputer. An output unit 15 is provided. In addition, the control device 2 includes a data storage unit 16 configured using a memory of a microcomputer and the like, and various programs for causing each unit of the control device 2 to function are stored in the data storage unit 16. . The data storage unit 16 can appropriately store data from each unit of the luminance inspection apparatus 1 such as an imaging result and data from the outside.

  The CCD camera 3 is configured to perform an imaging operation in accordance with an instruction signal from the imaging control unit 10, and performs imaging operation on all of the plurality of pixels of the liquid crystal display panel 22 to obtain imaging data as pixels. Get to the unit. In this case, the CCD camera 3 uses a two-dimensional sensor in which CCDs (Charge Coupled Devices) as a plurality of imaging elements are arranged in a plane. In the CCD camera 3, for example, a total of 1 million CCDs are arranged vertically and horizontally, and the liquid crystal display panel 22 is planarly imaged by these CCDs, and a luminance value is acquired for each CCD. .

  As shown in FIG. 3, the inspection illumination unit 4 includes a chassis 5 having a shallow box shape. Inside the chassis 5, a white LED 6 including a red LED 6R, a green LED 6G, and a blue LED 6B is provided. A plurality of bottom surfaces 5a are arranged so as to be even in the vertical and horizontal directions. White light is generated by mixing the colored light of the LEDs 6R, 6G, and 6B of the white LED 6.

  In addition, a diffusion plate 7 is provided on the front surface of the chassis 5, and light emitted from each white LED 6 is diffused by the diffusion plate 7 so that the dot image of each white LED 6 is erased. ing. The light emitted from the diffusing plate 7 is irradiated on the back surface of the liquid crystal display panel 22 with the luminance in the light emitting surface 7a being uniform. In this case, the inspection illumination unit 4 is turned on according to the instruction signal from the illumination unit control unit 12 of the control device 2 and irradiates illumination light from the back surface of the liquid crystal display panel 22. In such inspection illumination means 4, a large number of white LEDs 6 are arranged on the same plane, the luminance is uniformly uniform within the light emitting surface, and the light quantity is stable immediately after lighting, so that the luminance inspection of the liquid crystal display panel 22 is performed. The initial speed is improved. In FIG. 3, the white LED 6 is illustrated in a large size. The diameter of the white LED 6 is about 3 mm, and the distance between the centers of the white LEDs 6 is about 5 mm. Is used.

  In addition, as shown in FIG. 2, a fluorescent lamp 8a such as a cold cathode fluorescent tube is used for an inspection backlight 8 used for acquiring lamp image data (illumination unevenness data) described later. The inspection backlight 8 is turned on according to an instruction signal from the backlight control unit 13 of the control device 2. In this case, the inspection backlight 8 has the same configuration as the backlight that is shipped as a liquid crystal display device by being assembled integrally with the liquid crystal display panel 22 to be inspected.

  Therefore, the backlight control unit 13 acquires, in advance, backlight information about a backlight for a product that is assembled into the liquid crystal display panel 22 and integrated as a liquid crystal display device from an external device such as a system server. Based on the backlight information, the backlight control unit 13 generates an instruction signal and outputs the instruction signal to the inspection backlight 8.

  The signal control unit 11 outputs a driving test signal for inspection to the liquid crystal display panel 22, and displays the liquid crystal display panel 22 in units of pixels with a luminance value indicated by the driving inspection signal. Specifically, the drive inspection signal includes an instruction signal output to the gates and sources of a plurality of TFTs (thin film transistors) as active elements provided for each pixel of the liquid crystal display panel 22. In other words, the drive inspection signal is output to the gate of each TFT and output to the gate pulse signal for turning the gate on and off, and to the source of each TFT, and at the corresponding pixel, With the image (video) signal for displaying a predetermined image (inspection image), the gate is turned on to drive the liquid crystal display panel 22 in units of pixels. Further, the signal control unit 11 determines the voltage (source voltage) supplied to the source by determining the voltage signal to the source, and instructs the corresponding pixel to indicate the luminance value in the inspection image. .

  The correction data generation unit 14 includes a data conversion unit 14a and a correction data determination unit 14b. The correction value generation unit 14 includes a luminance value instructed by a drive inspection signal from the signal control unit 11 to the liquid crystal display panel 22, and a CCD camera. The correction data of the drive signal for driving the liquid crystal display panel 22 is generated for each pixel using the imaging data acquired in 3. In the correction data generation unit 14, the data conversion unit 14a compares the imaged data from the CCD camera 3 with the luminance value indicated by the drive inspection signal based on the luminance characteristics of the CCD camera 3. Convert to Further, the correction data determination unit 14 b determines drive signal correction data from the luminance value converted by the data conversion unit 14 a based on the luminance characteristics of the liquid crystal display panel 22. Thereby, in the luminance inspection apparatus 1, correction data for each pixel is generated according to each luminance value from the imaging result of the CCD camera 3 and can be reflected in the image display of the liquid crystal display panel 22.

  The data input / output unit 15 has an interface function, and exchanges data between the control device 2 and an external device such as a system server. The data input / output unit 15 constitutes a data output unit that writes correction data of the drive signal generated by the correction data generation unit 14 to the external storage device 17 as a storage unit on the liquid crystal display panel 22 side. . As described above, in the luminance inspection apparatus 1, the data input / output unit 15 outputs and stores the correction data to the external storage device 17, so that the correction data can be reflected in the display operation on the liquid crystal display panel 22. It is like that.

  Further, the control device 2 uses the imaging result obtained by imaging the light emitting surface 8b of the inspection backlight 8 alone without the liquid crystal display panel 22 as shown in FIG. A lamp image data (illumination unevenness data) generation unit 18 for acquiring unique illumination unevenness is provided.

  Specifically, the lamp image data (illumination unevenness data) generation unit 18 is obtained by imaging with the CCD camera 3 the light emitting surface 8b of the inspection backlight 8 alone when the light quantity of the lamp 8a is stabilized. Based on the imaging result (lamp luminance data), lamp image data (illumination unevenness data) 31 relating to the illumination unevenness 25 as shown in FIG. 4 is generated.

  In addition, the control device 2 is obtained by imaging the display screen 22a of the liquid crystal display panel 22 on which the inspection image is displayed in a state where the inspection illumination unit 4 as illustrated in FIG. By correcting the screen luminance data (panel unevenness data) 32 relating to the panel unevenness 26 as shown in FIG. 5A by adding the lamp image data (illumination unevenness data) 31 generated by the lamp image data generating unit 18 to the correction. A non-uniformity correction screen for generating non-uniformity correction screen luminance data 33 as shown in FIG. 5 (b) corresponding to imaging data when the liquid crystal display panel 22 having a stable backlight light intensity is imaged. A luminance data generation unit 19 is provided.

  Next, a luminance inspection method for the liquid crystal display panel 22 using the above-described luminance inspection apparatus 1 will be described.

  First, prior to the luminance inspection of the liquid crystal display panel 22 as shown in FIG. 1, the light emitting surface 8b of the inspection backlight 8 alone is imaged by the CCD camera 3 as shown in FIG. Specifically, when the light amount of the lamp 8a is stabilized, for example, the lamp brightness which is an imaging result obtained by imaging the light emitting surface 8b of the test backlight 8 30 minutes or 60 minutes after the start of lighting of the lamp 8a. From the data, lamp image data (illumination unevenness data) 31 is generated and stored in the data storage unit 16.

  Next, the display screen 22a of the liquid crystal display panel 22 on which the inspection image is displayed is picked up with the inspection illumination means 4 as shown in FIG. Then, screen luminance data (panel unevenness data) 32 as an imaging result is acquired by imaging by the CCD camera 3 and stored in the data storage unit 16.

  Then, the unevenness correction screen brightness data generation unit 19 uses the lamp image related to the illumination unevenness 25 similarly stored in the data storage unit 16 as the screen brightness data (panel unevenness data) 32 related to the panel unevenness 26 stored in the data storage unit 16. Correction is performed in consideration of data (illumination unevenness data) 31. Thus, although not actually performed, this corresponds to imaging data when the backlight 8 having a stable light quantity of the lamp 8a is arranged on the back surface and the display screen 22a of the liquid crystal display panel 22 is imaged by the CCD camera 3. The non-uniformity correction screen luminance data 33 is generated.

  The correction data generation unit 14 is instructed by the drive inspection signal from the signal control unit 11 to the liquid crystal display panel 22 and the luminance value and the unevenness correction screen luminance generated by the unevenness correction screen luminance data generation unit 19. Using the data 33, correction data of a drive signal for driving the liquid crystal display panel 22 is generated in units of pixels. In the data converter 14a, the unevenness correction screen luminance data 33 is converted into a luminance value for comparison with the luminance value instructed by the drive inspection signal. Further, the correction data determination unit 14 b determines drive signal correction data from the luminance value converted by the data conversion unit 14 a based on the luminance characteristics of the liquid crystal display panel 22.

  As a result, in the luminance inspection apparatus 1, pixel-by-pixel correction data is obtained from the unevenness correction screen luminance data 33 corresponding to the imaging data obtained by imaging the liquid crystal display panel 22 with the inspection backlight 8 having a stable light amount disposed on the back surface. It is generated according to each luminance value and can be reflected in the image display of the liquid crystal display panel 22 so that the illumination unevenness 25 and the panel unevenness 26 disappear in the state shown in FIG.

  As described above, when the inspection image of the liquid crystal display panel 22 is picked up, it has the same configuration as the backlight that is shipped as a liquid crystal display device by being assembled integrally with the liquid crystal display panel 22 to be inspected. By using the illuminating means 4 such as an LED backlight in which the luminance is uniform and uniform in the light emitting surface and the light quantity is stabilized immediately after lighting without using the inspection backlight 8, the liquid crystal display panel 22 can be used immediately after starting lighting. A luminance test can be performed, and the initial speed of the luminance test is improved.

  Further, lamp image data (illumination unevenness data) 31 is generated in advance based on lamp luminance data obtained by imaging the light emitting surface 8a of the inspection backlight 8 alone when the light amount of the lamp 8a is stabilized, The lamp image data (illumination unevenness data) 31 is added to the imaging data of the liquid crystal display panel 22, that is, the screen brightness data (panel unevenness data) 32 to generate the unevenness correction screen brightness data 33, whereby the light quantity of the lamp 8a is obtained. It is possible to obtain data corresponding to the image data when the liquid crystal display panel 22 is imaged using the backlight 8 in a stable state, and the illumination unique to the backlight 8 together with the panel unevenness 26 unique to the liquid crystal display panel 22. It is possible to generate correction data of a drive signal for driving the liquid crystal display panel 22 so that the unevenness 25 is eliminated. Kill.

  According to the luminance inspection apparatus and the luminance inspection method for the liquid crystal display panel described above, the lamp image data is based on the lamp luminance data obtained by imaging the light emitting surface 8b of the backlight 8 alone when the light quantity of the lamp 8a is stabilized. (Illumination unevenness data) 31 is generated in advance, and the luminance in which many white LEDs 6 are arranged on the same plane is uniformly uniform within the light emitting surface 7a, that is, there is little illumination unevenness, and the light quantity is stabilized immediately after lighting. Lamp image data (illumination unevenness data) 31 is added to screen brightness data (panel unevenness data) 32 obtained by imaging the display screen of the liquid crystal display panel 22 on which the illumination means 4 is arranged on the back surface and an inspection image is displayed. Screen luminance data 33 for correcting unevenness, that is, a liquid crystal display in a state where the light amount of the lamp 8a of the backlight 8 is stable It is possible to generate the equivalent of imaging data when imaging the channel 22.

  Then, the liquid crystal display panel 22 is driven based on unevenness correction screen luminance data 33 corresponding to imaging data when the CCD camera 3 images the display screen 22a of the liquid crystal display panel 22 in a state where the light amount of the lamp 8a is stable. By generating the correction data of the drive signal, it is possible to reflect it in the image display of the liquid crystal display panel 22 without the illumination unevenness 25 and the panel unevenness 26 as shown in FIG. Therefore, the luminance inspection of the liquid crystal display panel can be performed without waiting until the light quantity of the backlight becomes stable as in the conventional case, and the rapidity of the initial luminance inspection is improved.

  In the above, one embodiment of the luminance inspection apparatus and the luminance inspection method for a liquid crystal display panel according to the present invention has been described. However, the present invention is not limited to such an embodiment and is within the scope not departing from the gist of the present invention. Of course, various embodiments can be implemented.

  For example, in the above-described embodiment, the LED backlight has been described as an illumination unit in which the luminance is uniformly uniform within the light emitting surface and the light amount is stable immediately after lighting. However, in order to illuminate the liquid crystal display panel evenly, a large number of Any configuration having a point light source and a diffusion plate for diffusing light from the point light source may be used, and the present invention is not limited to the above-described embodiment.

1: Luminance inspection device 2: Control device 3: CCD camera 4: Inspection illumination means 5: Chassis 6: White LED 7: Diffuser 7a: Light emitting surface 8: Backlight for inspection 8a: Lamp 8b: Light emitting surface 9: Monitor DESCRIPTION OF SYMBOLS 10: Imaging control part 11: Signal control part 12: Illumination means control part 13: Backlight control part 14: Correction data generation part 14a: Data conversion part 14b: Correction data determination part 15: Data input / output part 16: Data storage part 17: External storage device 18: Lamp image data generation unit 19: Correction screen luminance data generation unit 22: Liquid crystal display panel 22a: Display screen 25: Illumination unevenness 26: Panel unevenness 31: Lamp image data (illumination unevenness data)
32: Screen luminance data (panel unevenness data) 33: Screen luminance data for correction

Claims (10)

  A device that inspects the brightness of the display screen of a liquid crystal display panel that controls the transmission of light from a backlight with a large number of lamps and displays the brightness uniformly and uniformly within the light-emitting surface. Immediately after the illumination means whose light quantity stabilizes, the light emitting surface of the backlight alone and the imaging means for imaging the display screen of the liquid crystal display panel on which the illumination means is arranged on the back, and when the light quantity of the lamp is stable Lamp image data generating means for generating lamp image data based on lamp luminance data obtained by imaging the light emitting surface of the backlight unit, and the illumination means are arranged on the back and an inspection image is displayed. For unevenness correction in which the lamp image data is added to screen luminance data obtained by imaging the display screen of the liquid crystal display panel Brightness inspection apparatus for liquid crystal display panel; and a non-uniformity correction screen brightness data generation means for generating a surface luminance data.   The brightness inspection of the liquid crystal display panel according to claim 1, further comprising correction data generation means for generating correction data of a drive signal for driving the liquid crystal display panel based on the unevenness correction screen brightness data. apparatus.   3. The luminance inspection apparatus for a liquid crystal display panel according to claim 1, wherein the illumination unit includes a plurality of light emitting diodes arranged on the same plane.   The brightness inspection apparatus for a liquid crystal display panel according to any one of claims 1 to 3, wherein the lamp is a fluorescent lamp such as a cold cathode fluorescent tube.   The brightness inspection apparatus for a liquid crystal display panel according to any one of claims 1 to 4, wherein the imaging means is a digital camera provided with a CCD.   A method for inspecting the brightness of a display screen of a liquid crystal display panel that performs display by controlling transmission of light from a backlight provided with a large number of lamps, wherein the backlight when the light quantity of the lamp is stabilized A process of acquiring lamp luminance data of a single light emitting surface with an imaging means, a step of generating lamp image data based on the lamp luminance data, and a uniform and uniform luminance within the light emitting surface, so that the light quantity is stable immediately after lighting. And a step of displaying an inspection image on a display screen on the liquid crystal display panel disposed on the back surface of the illuminating means, and screen luminance data of the display screen of the liquid crystal display panel on which the inspection image is displayed is acquired by the imaging means. And a step of generating unevenness correction screen luminance data in which the lamp image data is added to the screen luminance data. Brightness inspection method of the display panel.   7. The method of inspecting the brightness of a liquid crystal display panel according to claim 6, further comprising the step of generating correction data of a drive signal for driving the liquid crystal display panel based on the unevenness correction screen brightness data.   8. The luminance inspection method for a liquid crystal display panel according to claim 6, wherein the illuminating means comprises a plurality of light emitting diodes arranged on the same plane.   9. The luminance inspection method for a liquid crystal display panel according to claim 6, wherein the lamp is a fluorescent lamp such as a cold cathode fluorescent tube.   10. The luminance inspection method for a liquid crystal display panel according to claim 6, wherein the image pickup means is a digital camera provided with a CCD.

Images