JP2007085893A - Method of testing electro-optical device, device for testing the electro-optical device and method of manufacturing the electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a test device and a test method capable of measuring two-dimensional light distribution of monochromatic light, using a light source that emits white light. <P>SOLUTION: The test method includes a first process for transmitting the white light through a color filter for obtaining monochromatic light, a second process for introducing the monochromatic light in an electro-optical device and transmitting the display surface of the electro-optical device, and a third process for receiving the monochromatic light having transmitted the display surface of the electro-optical device and measuring the two-dimensional light distribution which is light intensity distribution at the measuring point for the angle that a line connecting the measuring point on the display surface of the electro-optical device forms to the normal of the display surface of the electro-optical device. By transmitting the white light through the color filter using the processes, a monochromatic light is obtained from the white color so that, by receiving the monochromatic light that has transmitted through the display surface of the electro-optical device in the second process, the two-dimensional light intensity distribution for the monochromatic light can be measured in the third process. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inspection method for an electro-optical device, an inspection device for an electro-optical device, and a method for manufacturing the electro-optical device.

  One of the evaluation items of the electro-optical device is a two-dimensional light distribution. The two-dimensional light distribution is the relationship between the angle formed by the line connecting the measurement point on the display surface of the electro-optical device and the observation point with respect to the normal of the display surface of the electro-optical device, and the light intensity at the measurement point. (Patent Document 1). Since the electro-optical device is generally used with a light source that emits white light, the measurement of the two-dimensional light distribution is also performed using white light.

JP 2005-114519 A

  However, in recent years, there has been an increasing use of a single product using three types of electro-optical devices, such as projectors, each corresponding to three colors of red, green, and blue. In such a case, the two-dimensional light distribution measurement method using the light source that emits white light has a problem that the two-dimensional light distribution for monochromatic light in accordance with the actual usage cannot be measured.

  In order to solve the above problems, an inspection method for an electro-optical device according to the present invention includes a first step of obtaining white light through a color filter to obtain monochromatic light, and causing the monochromatic light to enter the electro-optical device. A second step of transmitting or reflecting the display surface of the electro-optical device; and measuring the display surface of the electro-optical device by receiving the monochromatic light transmitted or reflected by the display surface of the electro-optical device. A third step of measuring a two-dimensional light distribution that is a light intensity distribution at the measurement point with respect to an angle formed by a line connecting the point and the observation point with respect to a normal of the display surface of the electro-optical device; ,including.

  According to the inspection method for an electro-optical device according to the present invention, in the first step, the monochromatic light is obtained from the white light by transmitting the white light through the color filter. In the step, the two-dimensional light distribution of the monochromatic light can be measured by receiving the monochromatic light transmitted or reflected on the display surface of the electro-optical device in the second step.

  Preferably, in the first step, a color filter that extracts red light, a color filter that extracts green light, or a color filter that extracts blue light is used as the color filter.

  According to the inspection method of the electro-optical device according to the present invention, the red light obtained by transmitting the white light through the color filter for extracting red light, the color filter for extracting green light, or the color filter for extracting blue light. A two-dimensional light distribution for light, green light, or blue light can be measured.

  In order to solve the above-described problem, a method for manufacturing an electro-optical device according to the present invention includes a step of inspecting the above-described electro-optical device.

  According to the method for manufacturing an electro-optical device according to the present invention, it is possible to measure a two-dimensional light distribution for monochromatic light, particularly red light, green light, or blue light in an inspection process, so that it is used with a light source other than white light. As for the electro-optical device, an electro-optical device that has been inspected under the same conditions as in actual use can be obtained.

  In order to solve the above problems, an inspection apparatus for an electro-optical device according to the present invention includes a light source that emits white light and an electro-optical device, and the display surface of the electro-optical device is substantially aligned with the optical axis of the light source. A line connecting the measurement point on the display surface of the electro-optical device and the observation point is received by the electro-optical device holding means that holds the optical optical device so as to be orthogonal to each other, and the light emitted from the electro-optical device A light receiving means for measuring a two-dimensional light distribution, which is an intensity distribution of light at the measurement point with respect to an angle formed with respect to a normal to the display surface of the electro-optical device, and a position between the light source and the electro-optical device holding means; And a color filter holding means for holding the color filter.

  With the configuration according to the present invention, the electro-optical device held on the optical axis of the light source that emits white light is irradiated with monochromatic light generated by the white light passing through the color filter. Therefore, the two-dimensional light distribution for monochromatic light can be measured while using a light source that emits white light.

  Preferably, at least one of the light source and the color filter holding unit and / or the electro-optical device holding unit and the light receiving unit is provided with a retardation plate holding unit to which a retardation plate can be attached and detached. It has.

  With the configuration according to the present invention, the monochromatic light obtained by transmitting the color filter is irradiated to the electro-optical device in which the phase difference plate is disposed in the vicinity of at least one of the surfaces. Therefore, it is possible to measure the two-dimensional light distribution of monochromatic light transmitted through the phase difference plate while using a light source that emits white light.

  In order to solve the above problems, an inspection apparatus for an electro-optical device according to the present invention holds a light source and the electro-optical device so that a part of the electro-optical device is positioned on the optical axis of the light source. An electro-optical device holding means capable of performing light reception of light emitted from the electro-optical device, and a line connecting a measurement point on the display surface of the electro-optical device and an observation point is the electro-optical device. A light receiving means for measuring a relationship between an angle formed with respect to the normal of the display surface and light intensity at the measurement point, between the light source and the electro-optical device holding means, and the electro-optical device holding means, A phase difference plate holding means that is positioned at least one of the light receiving means and to which the phase difference plate can be attached and detached.

  With the configuration according to the present invention, an electro-optic in which a phase difference plate is disposed between at least one of the light source and the electro-optical device holding unit and between the electro-optical device holding unit and the light receiving unit. The apparatus emits light emitted from the light source to measure a two-dimensional light distribution. Therefore, it is possible to measure the two-dimensional light distribution for the light transmitted through the phase difference plate.

  Preferably, the retardation plate holding means is in contact with at least a part of the bottom surface of the retardation plate and a substantially central point on each side of the side surface.

  With the configuration according to the present invention, the retardation plate holding means holds the side surface of the retardation plate by point contact. Therefore, with the retardation plate holding means fixed, the retardation plate can be rotated with the central axis as the optical axis, and the azimuth angle of the retardation plate can be finely adjusted. As a result, it is possible to confirm the azimuth angle at which the correction effect is further increased, and it is possible to select a retardation plate having a configuration in which the correction effect is further increased.

  Hereinafter, a transmissive liquid crystal display device (hereinafter referred to as a liquid crystal display device) of a TFT active matrix driving system with a built-in driving circuit as an electro-optical device according to an embodiment of the present invention will be described with reference to the drawings.

  First, the configuration of the liquid crystal display device according to the present embodiment will be described with reference to FIG. 1 and FIG.

  FIG. 1 is an equivalent circuit diagram of various elements, wirings, and the like in a plurality of pixels formed in a matrix, which constitute an image display area 200 described later (see FIG. 2) of the liquid crystal display device. In each of the plurality of pixels formed in a matrix constituting the image display region 200 of the liquid crystal display device according to the present embodiment, a pixel electrode 105 and a TFT 102 for controlling the switching of the pixel electrode 105 are formed. A data line 106 to which an image signal is supplied is electrically connected to the source of the TFT 102.

  Further, the gate electrode 103 is electrically connected to the gate of the TFT 102, and the scanning signal is sequentially applied to the scanning line 108 and the gate electrode 103 sequentially at a predetermined timing. The pixel electrode 105 is electrically connected to the drain of the TFT 102, and the image signal supplied from the data line 106 is written at a predetermined timing by closing the switch of the TFT 102 serving as a switching element for a certain period.

  An image signal of a predetermined level written in the liquid crystal as an example of the electro-optical material via the pixel electrode 105 is held for a certain period with the counter electrode formed on the counter substrate. The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the liquid crystal display device as a whole.

  In order to prevent the image signal held here from leaking, a storage capacitor 104 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 105 and the counter electrode. The storage capacitor 104 is provided side by side with the scanning line 108 and includes a fixed potential side capacitor electrode and a capacitor electrode 110 fixed at a constant potential.

  FIG. 2 shows a liquid crystal display of a TFT array substrate including an image display region 200 formed of a plurality of pixels formed in a matrix form shown in FIG. 1 as viewed from the counter substrate side together with each component formed thereon. It is a top view of a display apparatus.

  In the liquid crystal display device according to this embodiment, the TFT array substrate 202 and the counter substrate 204 are disposed to face each other. A liquid crystal layer (not shown) is sealed between the TFT array substrate 202 and the counter substrate 204, and the TFT array substrate 202 and the counter substrate 204 are provided in a seal material provided in a seal region around the image display region 200. 206 are bonded to each other.

  The sealing material 206 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 202 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. Further, a gap material such as glass fiber or glass bead is dispersed in the sealing material 206 so as to set the distance between the TFT array substrate 202 and the counter substrate 204 (inter-substrate gap) to a predetermined value.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 200 is provided on the counter substrate 204 side in parallel with the inside of the seal area where the sealant 206 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 202 side.

  A data line driving circuit 208 and an external circuit connection terminal 210 are provided along one side of the TFT array substrate 202 in a region located outside the sealing region where the sealing material 206 is disposed in the peripheral region. Further, the scanning line driving circuit 212 is provided along two sides adjacent to the one side so as to be covered with the frame light shielding film 53. Further, in order to connect the two scanning line driving circuits 212 provided on both sides of the image display area 200 in this way, the frame light shielding film 53 is covered along the remaining side of the TFT array substrate 202. A plurality of connection wirings 216 are provided.

  In addition, vertical conduction members 214 that function as vertical conduction terminals between the two substrates are disposed at the four corners of the counter substrate 204. On the other hand, the TFT array substrate 202 is provided with a vertical conduction terminal in a region facing these corner portions. Thus, electrical conduction can be established between the TFT array substrate 202 and the counter substrate 204.

  Note that the liquid crystal display device according to the present embodiment is modularized. That is, a flexible printed circuit board (hereinafter referred to as FPC) 25 is attached to the external circuit connection terminal 210 (see FIG. 3), and is housed in a case together with dustproof glass (not shown). For example, a plurality of signal lines connected to the external circuit connection terminal 210 or the inspection terminal are wired in the FPC 25, and a drive signal supplied from a drive signal supply device 330 described later is transmitted to the liquid crystal display device.

  Next, the configuration of the inspection apparatus according to the embodiment for inspecting the liquid crystal display device as described above will be described with reference to FIGS. FIG. 3 is a diagram showing a schematic configuration of the inspection apparatus according to the present embodiment, and FIGS. 4 and 5 are schematic diagrams showing combinations of color filter holding means and phase difference plate holding means. 6 is a diagram showing a schematic configuration of the two-dimensional light distribution measuring means in the inspection apparatus shown in FIG. 3, and FIGS. 7A and 7B show the function of the two-dimensional light distribution measuring means. It is a schematic diagram for demonstrating.

  In FIG. 3, an inspection apparatus includes two-dimensional light distribution measurement means 302, a stage 304 that holds a liquid crystal display device, a probe unit 308 provided with a plurality of probes (not shown), and white light as main parts in a housing 300. A light source 310 is provided. In addition, a drive signal supply device 330 that supplies a drive signal for inspection to the liquid crystal display device and an inspection terminal 340 as a viewing angle characteristic determination unit are provided outside the housing 300. The inspection terminal 340 is configured by a personal computer, a workstation, or the like.

  Then, a first retardation plate holding means 312 and a second retardation plate holding means 322, which can attach and detach a retardation plate above and below the stage 304, respectively, are a first retardation plate holding means mounting portion 314, and A second retardation plate holding means mounting portion 324 is provided.

  Further, a color filter holding means 332 detachably attaching a color filter is provided between the white light source 310 and the second retardation plate holding means mounting portion 324 that supports the second retardation plate holding means 322. The filter holding means mounting portion 334 is provided.

  The two-dimensional light distribution measuring unit 302 includes an optical system capable of measuring a two-dimensional light distribution. FIG. 3 shows the optical axis 645 of the optical system in the two-dimensional light distribution measuring means 302. In the housing 300, the two-dimensional light distribution measuring unit 302 is disposed above the stage 304. The detailed configuration of the two-dimensional light distribution measuring unit 302 will be described later.

  The white light source 310 irradiates the liquid crystal display device 20 held on the stage 304 with inspection light. The white light source 310 may be a fiber type, or may be configured using a laser device or a fluorescent tube. As shown in FIG. 3, the white light source 310 is disposed below the liquid crystal display device 20, that is, below the stage 304.

  The stage 304 is horizontally supported in the housing 300 by a moving mechanism unit 306 capable of moving the stage 304 in the horizontal direction indicated by an arrow A in FIG. Further, a recess 311 for placing the liquid crystal display device 20 to be inspected is formed on the upper surface of the stage 304. Further, the stage 304 is provided with an opening 309 for guiding inspection light emitted from a white light source 310 described later to the image display region 200 of the liquid crystal display device 20 placed on the stage 304.

  The probe unit 308 is supported in the housing 300 by a probe moving mechanism unit (not shown) and is movable in the vertical direction indicated by an arrow B shown in FIG. The probe unit 308 includes a plurality of probes corresponding to a plurality of signal lines wired to the FPC 25. As shown in FIG. 3, the probe unit 308 is connected to an inspection drive signal supply device 330, and a predetermined inspection drive signal output from the inspection drive signal supply device 330 is supplied to the probe unit 308. The Then, the probe unit 308 supplies the supplied inspection drive signal to a plurality of signal lines in the FPC 25 via a plurality of probes.

  The drive signal supply device 330 supplies a drive signal for inspection for displaying an image for inspection on the image display area 200 of the liquid crystal display device. As will be described later, since there are two types of images for inspection in this embodiment, all white and all black, the drive signal supply device 330 supplies image signals corresponding to the above two types.

  As described above, the first retardation plate holding unit 312 and the second retardation plate holding unit 322 are provided above and below the stage, and between the second retardation plate holding unit 322 and the white light source. Is provided with a color filter holding means 332. Therefore, the color filter holding means 332 holds the color filter that transmits only light of a wavelength in an arbitrary range, thereby allowing white light to pass through the color filter to the liquid crystal display device held on the stage. Arbitrary monochromatic light obtained can be irradiated. In addition, it is possible to irradiate the monochromatic light with a light transmitted through a phase difference plate. Further, the light modulated by the liquid crystal display device is transmitted through the phase difference plate with the two-dimensional light distribution measuring means 302. It is also possible to receive light.

  4 and 5 schematically show combinations of the first and second retardation plate holding means 322 and the color filter holding means 332. FIG. 4 includes a color filter holding unit 332 and further includes at least one of a first retardation plate holding unit 312 and a second retardation plate holding unit 322. 5 does not include the color filter holding unit 332 but includes at least one of the first retardation plate holding unit 312 and the second retardation plate holding unit 322. By selecting one of these combinations, the liquid crystal display device held by the stage 304 can be irradiated with white light or inspection light having a wavelength in an arbitrary range, and further, the inspection light is applied to the liquid crystal display device. Two-dimensional light distribution can be measured by transmitting through the retardation plate before, after, or both.

  Note that when applied to a reflective liquid crystal display device, the white light source 310 is disposed above the stage together with a half mirror and the like. Further, the color filter holding means mounting portion 334 can be disposed between the second retardation plate holding means mounting portion 324 and the stage.

  Next, the configuration and function of the two-dimensional light distribution measurement unit 302 will be described with reference to FIGS. 6 and 7 in addition to FIG. The two-dimensional light distribution measuring unit 302 is configured by using an optical system capable of measuring a two-dimensional light distribution as disclosed in, for example, Document 1 above.

  In FIG. 6, this optical system includes an objective lens 602, a relay lens system 604, and a filter 606. In FIG. 6, the optical axis 645 of the optical system is shown. 3 and 6, the image display surface 642 in the image display region 200 of the liquid crystal display device 20 is disposed near the front focal point of the objective lens 602 of the optical system shown in FIG. 6. In the present embodiment, the image display surface 642 is a measurement surface for the two-dimensional light distribution. In this embodiment, the diameter R of the measurement spot on the image display surface 642 varies depending on the shape of the objective lens 602 of the optical system shown in FIG. In the present embodiment, the diameter R of the measurement spot is preferably about 200 μm.

  The two-dimensional light distribution measuring unit 302 is provided with an imaging unit 608 as a light detecting unit that detects light from the optical system described above. For example, a CCD may be used as the light detection means. The objective lens 602 collects the emitted light from the image display surface 642 at a position corresponding to the angle and forms an image on the rear focal point. The relay lens system 604 reduces and re-images the image formed by the objective lens 602 on the light detection surface of the imaging unit 608 via the filter 606. An image re-imaged on the light detection surface is picked up by the image pickup means 608, and a two-dimensional light distribution is obtained. That is, the light detection surface in the image pickup means 608 is an image pickup surface. In FIG. 6, the detailed configuration of the imaging unit 608 is not shown.

  Here, the two-dimensional light distribution will be described with reference to FIGS. 7 (a) and 7 (b). In FIG. 7A, the two-dimensional light distribution is represented as, for example, a light intensity distribution corresponding to the elevation angle indicated by the angle θ and the azimuth angle indicated by the angle φ. As shown in FIG. 7A, the azimuth angle φ is defined at a 0 degree position on the measurement surface, and the left (L) 90 degree position is clockwise from the 0 degree position around the measurement point 600. , A 180 degree position, and a right (R) 90 degree position. The elevation angle θ is set to θ = 0 degrees when the observation point on the measurement surface is located directly above the measurement point 600, that is, on the normal line of the measurement surface, and the observation point is centered on the measurement point 600. When tilted on a concentric circle, the line connecting the observation point and the measurement point 600 represents the angle formed with respect to the normal line of the measurement surface. The position of the observation point on the measurement surface is defined by the azimuth angle φ.

  FIG. 7B schematically shows a two-dimensional light distribution that is imaged on the imaging surface. On the two-dimensional light distribution, a 0 degree position, a left (L) 90 degree position, a 180 degree position, and a right (R) 90 degree position of the azimuth angle φ are defined clockwise.

  Here, in FIG. 6, the angle formed by the light emitted from the image display surface 642 and incident on the objective lens 602 with respect to the optical axis 645 corresponds to the elevation angle θ. The elevation angle θ is converted into a distance y on the rear focal plane by the objective lens 602, and is made a distance proportional to the distance y on the imaging plane by the relay lens system 604. Therefore, for example, in FIG. 7A, the light intensity distribution at the elevation angle θ = 60 degrees is represented as a circle centered at the position showing the elevation angle of 0 degrees according to the azimuth angle φ. The light intensity distribution at the elevation angle θ = 10 degrees is represented as a circle having a smaller diameter than the circle representing the light intensity distribution at the elevation angle θ = 60 degrees.

  Next, the inspection of the liquid crystal display device 20 performed by the inspection apparatus 10 will be described with reference to FIGS. FIG. 8A, FIG. 8B, and FIG. 8C are diagrams showing examples of measurement results of the two-dimensional light distribution measured by the inspection apparatus 10, and FIG. It is a viewing angle characteristic figure which shows the measurement result of the two-dimensional light distribution represented by taking an elevation angle on an axis | shaft and taking light intensity and contrast on a vertical axis | shaft.

  When the liquid crystal display device 20 is inspected, the image display surface 642 is disposed at the front focal position of the optical system in the two-dimensional light distribution measuring unit 302. By moving the stage 304 automatically by the moving mechanism unit 306, Positioning can be performed easily.

  Also, the inspection drive signal output from the drive signal supply device 330 is supplied to the liquid crystal display device 20 via the probe unit 308. In the liquid crystal display device 20, the scanning signal and the image signal output from the scanning line driving circuit 212 and the data line driving circuit 208 are supplied to each pixel unit based on the supplied inspection driving signal. An image is displayed in the display area 200. In the present embodiment, in the image display area 200 based on the inspection drive signal, all white display is performed as a bright state and all black display is performed as a dark state.

  Then, the two-dimensional light distribution measurement unit 302 measures the two-dimensional light distribution in each of the all white display and the all black display. The display light from the image display area 200 is incident on the two-dimensional light distribution measuring unit 302, and the display light is received by the imaging unit 608 through the optical system described above, thereby measuring the two-dimensional light distribution. Is called. Note that the display light of the liquid crystal display device 20 is emitted from the liquid crystal display device 20 as transmitted light of the inspection light emitted from the white light source 310 to the image display region 200.

  The inspection terminal 340 determines the viewing angle characteristics in the liquid crystal display device 20 based on the two-dimensional light distribution distributed by the imaging unit 608 in the two-dimensional light distribution measuring unit 302.

  FIG. 8A shows an example of the measurement result of the two-dimensional light distribution in all black display. With respect to the measurement results shown in FIG. 8A, the distribution of light intensity according to the elevation angle θ when the azimuth angle φ is in the vicinity of the left (L) 135 degrees and the right (R) 45 degrees is shown as a viewing angle characteristic curve 902 in FIG. expressed. The elevation angle θ corresponding to the peak in the viewing angle characteristic curve 902 for all black display, that is, the value at which the light intensity is minimum, is about 0 degrees indicating the vicinity of the front face of the image display surface 642.

  FIG. 8A shows a two-dimensional light distribution in the range where the elevation angle θ is 0 degree to 30 degrees on the left side and the right side, respectively. 8A, when the azimuth angle φ is changed to the left (L) 135 degrees and the right (R) 45 degrees and the elevation angle θ is changed to the left side, the two-dimensional light distribution according to the elevation angle θ is It is represented in a direction heading obliquely upward to the left along a dotted line indicating a left side (L) azimuth angle of 135 degrees from a position indicating an elevation angle of 0 degrees. On the other hand, when the elevation angle θ is changed to the right side when the azimuth angle φ is in the vicinity of the left side (L) 135 degrees and the right side (R) 45 degrees, the two-dimensional light distribution depends on the elevation angle θ from the position showing the elevation angle 0 degrees. It is represented in a direction toward the lower right along the dotted line indicating the azimuth angle of 45 degrees on the right side (R). Further, in FIG. 9, the elevation angle θ when changed to the left side is shown as a negative (−) value, and the elevation angle θ when changed to the right side is shown as a positive (+) value.

  In addition, in FIG. 9, regarding the measurement result of the two-dimensional light distribution in the all white display, the distribution of light intensity according to the elevation angle θ when the azimuth angle φ is around 135 degrees on the left side (L) and 45 degrees on the right side (R) is This is represented as a viewing angle characteristic curve 904 for all white display. The peak in the viewing angle characteristic curve 904, that is, the elevation angle θ corresponding to the value at which the light intensity becomes maximum in the all white display, is around 0 degrees indicating the vicinity of the front face of the image display surface 642.

  The measurement result shown in FIG. 8A shows the ratio of the light intensity value in the viewing angle characteristic curve 902 shown in FIG. 9 to the value at which the light intensity becomes maximum in the viewing angle characteristic curve 904 shown in FIG. It is calculated every time and expressed as a distribution of the ratio. In FIG. 8 (a), the elevation angle is 0 degree, that is, in the vicinity of the front in front of the image display surface 642, concentrically, within the range of the elevation angle on the right side from 0 to 30 degrees and the elevation angle on the left side from 0 to 30 degrees. The light intensity distribution changes from 0 [%] to 40 [%]. In FIG. 8A, the ratio calculated as described above is an area that is 0 [%], an area that is 10 [%], an area that is 20 [%], and 30 [%]. The measurement results are shown separately for the region and the region of 40%.

  FIG. 8B shows a two-dimensional distribution represented as a contrast ratio distribution by calculating a ratio of light intensity in all white display and light intensity in all black display, that is, a contrast ratio, for each elevation angle. The measurement result of the light distribution is shown in the same manner as in FIG. In the measurement result shown in FIG. 8B, the contrast ratio value according to the elevation angle θ when the azimuth angle φ is around the left side (L) 135 degrees and the right side (R) 45 degrees is the viewing angle characteristic of the contrast ratio in FIG. It is represented as curve 906. In the viewing angle characteristic curve 906 shown in FIG. 9, the value of the contrast ratio becomes maximum near an elevation angle of 0 degrees, that is, near the front of the image display surface 642.

  The elevation angle θ at which the contrast ratio value is maximized is preferably 0 degree, and if it deviates greatly from 0 degree, display characteristics may be impaired. Therefore, when determining the viewing angle characteristics, a predetermined range is determined, and a product within the range is determined as a non-defective product.

  It has been found that the “deviation” shows a slightly different value even when the same liquid crystal display device is measured depending on the wavelength of the inspection light, that is, the color of the inspection light. On the other hand, the deterioration of display characteristics due to the “displacement” can be corrected to some extent by the phase difference plate. Therefore, for a liquid crystal display device that is irradiated with monochromatic light instead of white light, it is preferable to perform two-dimensional orientation distribution measurement and determination of viewing angle characteristics based on the result for monochromatic light. Furthermore, for a liquid crystal display device that is used with a phase difference plate disposed on at least one of the light-irradiated surface and the display surface, the two-dimensional orientation distribution measurement and the viewing angle characteristics based on the result are shown. The determination is preferably performed after a retardation plate is arranged. An inspection method and an inspection apparatus according to the present invention include a first retardation plate holding unit 312, a second retardation plate holding unit 322, and a color filter holding unit 332 added to a conventional two-dimensional orientation measuring apparatus. Thus, it is possible to measure the two-dimensional orientation distribution that matches the usage mode of the liquid crystal display device used in the above mode.

  10 to 13 show the measurement results of the two-dimensional orientation distribution when the same liquid crystal display device is irradiated with white light and monochromatic light using the inspection device of the present embodiment. As in FIG. 8, the light intensity is concentrically centered around the elevation angle of 0 degrees, that is, near the front of the image display surface 642, within the range of the elevation angle on the right side from 0 to 30 degrees and the elevation angle on the left side from 0 to 30 degrees. The distribution is shown by dividing every 10%.

  10 is a two-dimensional orientation distribution for white light, FIG. 11 is a two-dimensional orientation distribution for red light, FIG. 12 is a two-dimensional orientation distribution for green light, and FIG. 13 is a two-dimensional orientation distribution for blue light. An example is shown, and (a) is all black display, (b) is contrast, and (c) is all white display.

  As shown in the figure, even in the same liquid crystal display device, different two-dimensional orientation distributions can be obtained depending on the color (wavelength) of the inspection light, and the result of the elevation angle θ at which the contrast ratio value is maximized is also different. Therefore, by using the inspection device of this embodiment or the inspection method of this embodiment, a liquid crystal display device in which the deterioration of display characteristics due to the elevation angle θ deviating from 0 degrees exceeds a predetermined range is reliably selected. It can avoid being supplied to the outside.

  The reason why the two-dimensional orientation distribution of the liquid crystal display device should be inspected with monochromatic light is not only that the two-dimensional orientation distribution differs depending on the wavelength. When the liquid crystal display device is irradiated with monochromatic light as the inspection light, the transmittance varies depending on the wavelength of the inspection light, and the two-dimensional orientation distribution in the same liquid crystal display device when displaying all white by the applied voltage is also different. It is also a reason to show a value.

  FIG. 14 shows the relationship between the applied voltage and the transmittance when the liquid crystal display device is irradiated with monochromatic light. The red light transmittance curve 132 and the green light transmittance curve 134 indicate that the transmittance increases as the applied voltage increases. On the other hand, the transmittance curve 136 of blue light shows that the transmittance becomes maximum when the applied voltage is around 3.5 volts.

  The liquid crystal display device performs gradation display by dividing the voltage between the maximum transmittance and the zero voltage at a predetermined level. Therefore, the maximum applied voltage is set to 3.5 volts when the above liquid crystal display device is used in a mode where blue light is irradiated, and the maximum voltage is applied when used in a mode where red light or green light is irradiated. Set the voltage to 5.0 volts.

  Therefore, it is certain that monochromatic light will be irradiated when used as a product, but it is not certain which wavelength (color) light will be irradiated. In the inspection, it is preferable to set the applied voltage to 3.5 volts, and in the inspection with red light and green light, the applied voltage is preferably set to 5.0 volts. In other words, it is necessary to change the applied voltage depending on the irradiated light, and the two-dimensional orientation distribution also shows different values depending on the applied voltage. Therefore, in order to make the applied voltage at the time of inspection identical to the applied voltage at the time of use, The light needs to be monochromatic.

Next, the retardation plate holding means according to the present invention will be described. FIG. 15 is a diagram showing a form of the retardation plate holding means 312 in the present invention. 15 (a) is a plan view, FIG. 15 (b) is a cross-sectional view taken along the line AA 'of FIG. 15 (a), and FIG. , Referred to as retardation plate holding means). FIG. (The same applies to the second retardation plate holding means.)
The retardation plate holding means 312 is a substantially square flat frame-like member surrounding the substantially square holding means opening 156, and a step portion 158 for placing the retardation plate 316 is formed inside. Yes. As shown in FIG. 15A, the planar shape of the stepped portion is not a square, but a shape composed of four corner portions 159 and four central points 152 and a straight line portion connecting the corner portions 159 and the central point 152. is there. And each straight part inclines in the outer peripheral direction as it goes to the corner part 159. That is, the angle formed by the two straight portions toward one corner 159 is an acute angle of less than 90 degrees.

When a substantially square phase difference plate having a length of one side substantially equal to the length connecting the two center points 152 facing each other is placed on the stepped portion, the substantially central portion of each side is the stepped portion. It contacts the center point 152 of 158. The line 154 in FIG. 15A indicates the position when it is assumed that the phase difference plate is placed so that each side is parallel to the outer peripheral line of the phase difference plate holding means 312. As shown in the drawing, the stepped portion 158 is not covered with a retardation plate except for the vicinity of the center point 152. Therefore, the phase difference plate can be moved within a predetermined angle in the rotational direction about the optical axis 645 indicated by the arrow C in FIG. 15C.
The angle is determined by the degree of inclination of the linear portion. Therefore, according to the retardation plate holding means 312 according to the present invention, the retardation plate is obtained by slightly rotating the inspection light irradiated on the liquid crystal display device 20 held by the stage 304 around the optical axis. Permeated. The same applies to the inspection light transmitted through the liquid crystal display device 20.

  It has been empirically found that the above-described effect of correcting the viewing angle characteristics by the retardation plate varies when the retardation plate is rotated and the angle between the retardation plate and the liquid crystal display device is changed. Therefore, by using the retardation plate holding means according to the present invention and measuring the two-dimensional orientation distribution of the liquid crystal display device while rotating the retardation plate, the angle at which the correction effect is maximized can be calculated. As a result, for the liquid crystal display device used in combination with the phase difference plate, the two-dimensional orientation distribution can be measured by rotating the phase difference plate so that the angle is the same as the angle at the time of the combination. Inspection can be performed. When the angle at the time of the combination is not determined, the angle can be formed by calculating the angle at which the correction effect becomes the highest.

The equivalent circuit diagram of a liquid crystal display device. The top view of a liquid crystal display device. The figure which shows schematic structure of the inspection apparatus which concerns on this embodiment. Schematic which shows the combination of a color filter holding means and a phase difference plate holding means. Schematic which shows the combination of a phase difference plate holding means. The figure which shows schematic structure of a two-dimensional light distribution measuring means. The schematic diagram for demonstrating the function of a two-dimensional light distribution measuring means. The figure which shows an example of the two-dimensional orientation distribution of a liquid crystal display device. View angle characteristic diagram. The figure which shows an example of the two-dimensional orientation distribution about white light. The figure which shows an example of the two-dimensional orientation distribution about red light. The figure which shows an example of the two-dimensional orientation distribution about green light. The figure which shows an example of the two-dimensional orientation distribution about blue light. The figure which shows the relationship between the applied voltage and transmittance | permeability of a liquid crystal display device. The figure which shows formation of a phase difference plate holding means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inspection apparatus, 20 ... Liquid crystal display device, 25 ... FPC, 53 ... Frame light shielding film, 102 ... TFT, 103 ... Gate electrode, 104 ... Storage capacitor, 105 ... Pixel electrode, 106 ... Data line, 108 ... Scanning line, 110 ... capacitance electrode, 132 ... red light transmittance curve, 134 ... green light transmittance curve, 136 ... blue light transmittance curve, 152 ... center point, 154 ... when a phase difference plate is assumed to be mounted 156 ... holding means opening 158 ... step part, 159 ... corner, 200 ... image display area, 202 ... TFT array substrate, 204 ... counter substrate, 206 ... sealing material, 208 ... data line driving circuit, 210 ... External circuit connection terminal, 212... Scanning line drive circuit, 214... Vertical conduction member, 216 .. connection wiring, 300 .. casing, 302 .. two-dimensional light distribution measuring means, 304. 308 ... probe unit 309 ... opening part 310 ... white light source 311 ... concave part 312 ... first retardation plate holding means 314 ... first retardation plate holding means mounting part 322 ... second Retardation plate holding means, 324... Second retardation plate holding means mounting portion, 330... Drive signal supply device, 332... Color filter holding means, 334 ... Color filter holding means mounting portion, 340. Lens, 604 ... Relay lens system, 606 ... Filter, 608 ..., Imaging means, 642 ... Image display surface, 645 ... Optical axis, 902 ... Viewing angle characteristic curve for all black display, 904 ... Viewing angle characteristic curve for all white display 906: Viewing angle characteristic curve of contrast ratio.

Claims (7)

A first step of transmitting white light through a color filter to obtain monochromatic light;
A second step of causing the monochromatic light to enter the electro-optical device and transmitting or reflecting the display surface of the electro-optical device;
A line connecting the measurement point and the observation point of the display surface of the electro-optical device by receiving the monochromatic light transmitted or reflected through the display surface of the electro-optical device is a method of the display surface of the electro-optical device. A third step of measuring a two-dimensional light distribution, which is a light intensity distribution at the measurement point with respect to an angle formed with respect to the line, and an inspection method for an electro-optical device.   The said 1st process uses the color filter which extracts red light, the color filter which extracts green light, or the color filter which extracts blue light as said color filter, The color filter which extracts blue light is characterized by the above-mentioned. Inspection method of electro-optical device.   A method for manufacturing an electro-optical device, comprising a step of inspecting the electro-optical device using the inspection method according to claim 1. A light source that emits white light;
Electro-optical device holding means for holding the electro-optical device so that the display surface of the electro-optical device is substantially perpendicular to the optical axis of the light source;
Receiving light emitted from the electro-optical device, the angle between the line connecting the measurement point of the display surface of the electro-optical device and the observation point with respect to the normal of the display surface of the electro-optical device A light receiving means for measuring a two-dimensional light distribution that is an intensity distribution of light at the measurement point;
A color filter holding means for holding a color filter located between the light source and the electro-optical device holding means;
An inspection apparatus for an electro-optical device, comprising:   Retardation plate holding means capable of detaching a retardation plate is provided at least one of the light source and the color filter holding means and between the electro-optical device holding means and the light receiving means. The inspection apparatus for an electro-optical device according to claim 4. A light source;
Electro-optical device holding means capable of holding the electro-optical device so that a part of the electro-optical device is positioned on the optical axis of the light source;
An angle formed by a line connecting a measurement point on the display surface of the electro-optical device and an observation point with respect to a normal line of the display surface of the electro-optical device; A light receiving means for measuring the relationship with the light intensity at the measurement point;
Retardation plate holding means that is located between at least one of the light source and the electro-optical device holding unit and between the electro-optical device holding unit and the light receiving unit, and capable of detaching a retardation plate;
An inspection apparatus for an electro-optical device, comprising: 7. The electro-optic according to claim 5, wherein the retardation plate holding means is in contact with at least a part of a bottom surface of the retardation plate and a substantially central point of each side of the side surface. Equipment inspection device.

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