JP2011198604A - Organic el substrate inspection device and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection device that accurately discriminates a bulkhead and an organic light emitting layer from an imaged picture and detects only a defect mode causing a significant defect to a display unit, and an inspection method.SOLUTION: An inspection device for an organic electroluminescence (organic EL) substrate having a transparent electrode layer formed on a TFT substrate and a bulkhead and an organic light emitting layer that are arrayed in a pattern on the transparent electrode layer comprises a sample moving means to place the organic EL substrate moving on an XY plane, a light irradiation means to irradiate illumination light to the organic light emitting layer side of the organic EL substrate, an imaging means to convert the reflective light from the organic EL substrate into the electrical signal for obtaining such data, and an image processing means to perform arithmetic processing for image data which are thus obtained by the imaging means where the image processing means performs the following processing.

Description

  The present invention relates to an inspection apparatus and an inspection method for an organic electroluminescence (organic EL) substrate.

  A display device using an organic EL substrate is expected to be applied to a display in recent years because of its features such as space saving and light weight due to its thinness and high luminance emission even at an applied voltage of about 10V. Has been.

  The organic EL substrate has a structure in which an electronic material layer capable of emitting light is held in a space partitioned by embossing or partitioning, and the electronic material layer is sandwiched between a pair of electrodes. By applying a voltage between the electrodes, holes and electrons are injected into the light emitting layer of the electronic material layer, an electroluminescence light emission phenomenon occurs, and the display device functions.

  As the electrode, a transparent electrode such as ITO (Indium Tin Oxide) is used on the light extraction side, and a reflective metal electrode such as aluminum is used on the opposite substrate.

  The electronic material is a laminate of a hole transport layer, a light emitting layer, and an electron transport layer. An organic electronic material is used for the light emitting layer. The hole transport layer and the electron transport layer are used for increasing the light emission efficiency of the light emitting layer.

  In such a configuration, electrons and holes are injected from both electrodes into the light emitting layer through the electron transport layer and the hole transport layer, and the electrons and holes are recombined in the light emitting layer to emit light. A display device for displaying a color image has a structure in which organic EL (element) pixels of three primary colors (RGB) are arranged in order on a substrate, and each organic EL element is a sub-pixel.

  An active matrix method can be given as a driving method of the display device. In this method, each layer is formed on a substrate provided with a thin film transistor (TFT). By adopting a structure in which light emitted from the light emitting layer is extracted from the opposite side of the TFT substrate (top emission structure), light can be extracted regardless of the wiring on the TFT substrate, so that the aperture ratio can be increased.

  An organic EL panel is formed on the TFT substrate with the above configuration. In order to function as a final display device, a transparent substrate such as glass is used in order to prevent entry of oxygen and moisture from the outside. It is necessary to seal.

  With the above configuration, when there is a foreign matter or a light emitting layer missing (white spot) on the organic EL element, when the display device is driven as it is through the sealing process, the voltage applied to the element is not a foreign matter or white spot. Since the current flows through the part, the entire element becomes a non-light emitting state (dark spot). Therefore, it is necessary to perform a foreign matter / white spot inspection on the entire organic EL substrate before the sealing step.

  Further, the white spot inspection of the organic EL substrate may be limited to only the area that actually emits light in the entire substrate. This is because even if white spots occur on the partition wall, no light is emitted on the partition wall, so that there is no defect on the display device. For this reason, it is required that the inspection area is appropriately limited for the white spot inspection.

  Although a systematic inspection technique has not been reported for the inspection of the organic EL substrate, a method of performing a comparison process adopted in Patent Document 1 is generally used for the appearance inspection of a substrate having a repetitive pattern.

JP 2006-71521 A

  The present invention has been made in order to solve the above-described problem. An inspection apparatus and an inspection method for accurately discriminating a partition wall and an organic light emitting layer from a captured image and detecting only a defect mode that gives a serious defect to a display device. It is an issue to provide.

As means for solving the above problems, the invention according to claim 1 includes a transparent electrode layer formed on the TFT substrate, a partition wall and an organic light emitting layer arranged in a pattern on the transparent electrode layer. An inspection apparatus for an organic electroluminescence (organic EL) substrate,
A sample moving means for placing the organic EL substrate and moving it on the XY plane;
A light irradiation means for irradiating illumination light to the organic light emitting layer side of the organic EL substrate;
Imaging means for converting reflected light from the organic EL substrate into an electrical signal and converting it into data;
An organic EL substrate inspection apparatus comprising: an image processing unit that performs arithmetic processing on image data obtained by the imaging unit, wherein the image processing unit performs the following processing.
[A] The comparison pixel is a point separated from the target pixel of the image data by the repetitive pitch of the organic EL substrate, and four comparative pixels are set in the vertical and horizontal directions with respect to the target pixel.
[B] Referring to the luminance values of the target pixel and the comparison pixel, if there are three or more pixels having luminance values exceeding a preset threshold value B, the target pixel is determined as a partition wall and exceeds the threshold value B When the number of comparison pixels having a luminance value is two or less, the target pixel is determined as the organic light emitting layer portion.
[C] Sort five luminance values of the target pixel and the comparison pixel, and perform a difference between the luminance value of the target pixel and the sorted median value.
[D] A threshold value D for the difference value is set separately for each of the partition wall and the organic light emitting layer, and when the target pixel is a partition wall, the target pixel exceeding the threshold D1 in the partition wall is determined. When the defect is a partition wall defect and the target pixel is an organic light emitting layer part, the target pixel exceeding the threshold D2 in the organic light emitting layer part is determined as an organic light emitting layer part defect.

  Further, in the invention described in claim 2, the emission spectrum of the light irradiating means has a single wavelength, and preferably has an emission peak in the vicinity of 800 nm to 850 nm. Inspection equipment.

  According to a third aspect of the present invention, only the regular reflection light out of the reflected light from the organic EL substrate is converted into data in the imaging means, and preferably the light irradiation means and the imaging means are the organic EL substrate. The organic EL substrate inspection apparatus according to claim 1, wherein the organic EL substrate inspection apparatus is disposed at an angle of 40 ° to 45 ° with respect to a vertical plane relative to the vertical axis.

  According to a fourth aspect of the present invention, in the image processing means, the threshold value D2 is set to be positive and negative in advance, and the target pixel that exceeds the positive threshold value exceeds a white defect and a negative threshold value. The pixel of interest is classified as a black defect, and the white defect detected in the organic light emitting layer portion is derived from the absence of the organic light emitting layer, and the black defect is derived from a foreign substance existing on the organic light emitting layer. 2. The black defect detected in the partition wall portion is determined to be derived from a foreign substance existing on the partition wall portion among the black defects detected in the partition wall portion. It is an organic electroluminescent board | substrate test | inspection apparatus in any one of -3.

According to a fifth aspect of the present invention, there is provided an organic electroluminescence (organic EL) substrate having a transparent electrode layer formed on a TFT substrate, partition walls and an organic light emitting layer arranged in a pattern on the transparent electrode layer. An inspection method,
A sample moving means for placing the organic EL substrate and moving it on the XY plane;
A light irradiation means for irradiating illumination light to the organic light emitting layer side of the organic EL substrate;
Imaging means for converting reflected light from the organic EL substrate into an electrical signal and converting it into data;
In the organic EL substrate inspection method, the following processing is performed in the image processing unit using an image processing unit that performs arithmetic processing on image data obtained by the imaging unit.
[A] The comparison pixel is a point separated from the target pixel of the image data by the repetition pitch of the organic EL substrate, and four comparative pixels are set in the vertical and horizontal directions with respect to the target pixel.
[B] Referring to the luminance values of the target pixel and the comparison pixel, if there are three or more pixels having luminance values exceeding a preset threshold value B, the target pixel is determined as a partition wall and exceeds the threshold value B When the number of comparison pixels having a luminance value is two or less, the target pixel is determined as the organic light emitting layer portion.
[C] Sort five luminance values of the target pixel and the comparison pixel, and perform a difference between the luminance value of the target pixel and the sorted median value.
[D] A threshold value D for the difference value is set separately for each of the partition wall and the organic light emitting layer, and when the target pixel is a partition wall, the target pixel exceeding the threshold D1 in the partition wall is determined. When the defect is a partition wall defect and the target pixel is an organic light emitting layer part, the target pixel exceeding the threshold D2 in the organic light emitting layer part is determined as an organic light emitting layer part defect.

  In the invention according to claim 6, the emission spectrum of the light irradiation means has a single wavelength, and preferably has an emission peak in the vicinity of 800 nm to 850 nm. Inspection method.

  In the invention according to claim 7, of the reflected light from the organic EL substrate, only the regular reflection light is converted into data in the imaging means, and preferably the light irradiation means and the imaging means are the organic EL substrate. The organic EL substrate inspection method according to claim 5, wherein the organic EL substrate inspection method is arranged so as to be inclined at an angle of 40 ° to 45 ° with respect to a vertical plane.

  In the image processing means, the threshold value D is set separately for each positive and negative in advance, and the pixel of interest exceeding the positive threshold is set as a white defect and a negative threshold is set. The pixel of interest that has passed is classified as a black defect, and the white defect detected in the organic light emitting layer portion is derived from the absence of the organic light emitting layer, and the black defect is derived from a foreign substance existing on the organic light emitting layer It is determined that the black defect detected in the partition wall and the black defect exceeding a preset threshold value E is determined to be derived from a foreign substance existing on the partition wall. The organic EL substrate inspection method according to any one of Items 5 to 7.

  According to the present invention, in the quality inspection of the organic EL substrate, it is possible to detect foreign matter on the partition wall, foreign matter on the organic light emitting layer, and omission among defects present on the substrate.

It is a figure which shows typically the organic electroluminescent board | substrate which is a test object of this invention. The schematic diagram of the organic substrate test | inspection apparatus which concerns on this invention. (A) The figure which shows the whole organic electroluminescent board | substrate inspection apparatus. (B) The schematic diagram showing the optical arrangement | positioning of a light irradiation part and an imaging part. The figure for demonstrating the characteristic in the image obtained when an organic electroluminescent board | substrate is imaged. (A) A schematic diagram of an image. (B) Line profile of the image. The figure for demonstrating the comparison process which concerns on this invention. (A) The figure for demonstrating an attention pixel and a comparison pixel. (B) The figure for demonstrating after a comparison process. The flowchart figure for demonstrating the test | inspection process which concerns on this invention. The figure for demonstrating an inspection process.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a diagram schematically showing an organic electroluminescence (organic EL) substrate which is an inspection object of the present invention. In the organic EL substrate to be inspected, the TFT elements 4 are arranged in a pattern on the translucent substrate 6, and the partition walls 3 are formed thereon. In the area delimited by the partition walls 3, the transparent electrode layer 5, the transparent functional layer 2, and the organic light emitting layer 1 are laminated. In addition, the organic light emitting layer 1 is repeatedly arranged in order of organic electronic materials having red, green, and blue light emission peaks.

  In addition, as a structure of an organic electroluminescent board | substrate, it should just be comprised with the transparent electrode, the functional material, and the organic electronic material, and various materials may be used for the functional material.

  The translucent substrate 6 is constituted by a glass substrate or a plastic film or sheet. As the plastic film, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, and polycarbonate can be used, but are not limited thereto. A gas barrier film such as a ceramic vapor-deposited film, polyvinylidene chloride, polyvinyl chloride, or a saponified ethylene-vinyl acetate copolymer may be laminated on the other surface where the transparent electrode layer 5 is to be formed.

  The material of the transparent electrode layer 5 is indium oxide / tin (ITO), indium oxide / zinc (IZO), zinc composite oxide, metal composite oxide such as zinc aluminum composite oxide, tin oxide (SnO2) or zinc oxide. (ZnO), indium oxide, or the like can be used. Further, it can be formed by a coating pyrolysis method in which an oxide is formed by thermal decomposition after applying a precursor such as indium octylate or acetone indium, but is not limited thereto.

  The partition wall 3 has an enclosure shape to prevent the organic light emitting layer 1 from mixing. The partition wall 3 is made of a positive or negative photosensitive resin, and after the photosensitive resin is applied on the translucent substrate 6 by using a coating method such as a spin coater, bar coater, roll coater, die coater, or gravure coater. , By patterning into a predetermined shape using a photolithographic technique. Applicable photosensitive resins include polyimide, acrylic resin, and novolac resin, but are not limited thereto.

A hole transport layer is disposed as the transparent functional layer 2. The hole transport layer has a function of advancing holes injected from the transparent electrode layer 5 in the direction of the counter electrode and preventing electrons from proceeding in the direction of the transparent electrode layer 5 while passing the holes. In addition, the hole transport layer can be formed by using a wet coating method such as spin coating, bar coating, wire coating, or slit coating with a solution or dispersion of a hole transport material that is a functional material. It is not limited to.

Examples of materials that can be used for the hole transport layer as the transparent functional layer 2 include polyanine derivatives, polythiophine derivatives, polyvinylcarbazole derivatives, PEDOT (poly (3,4-ethyloxyoxyphone)) PEDOT, and polystyrenesulfonic acid (PEDOT / PSS) and the like. The solvent to be dissolved or dispersed is any one of toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, water, or a mixture thereof. However, it is not limited to this.
Moreover, you may add surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber etc. to the solution or dispersion liquid of the hole transport material mentioned above as needed.

  Since the hole transport layer as the transparent functional layer 2 is laminated after the barrier ribs are formed, the center is flat in the portion surrounded by the barrier ribs 3 and the film thickness is increased in the vicinity of the barrier ribs 3. In other words, the transparent functional layer 2 at the location surrounded by the partition walls 3 is a bathtub type.

  The organic light emitting layer 1 is a functional material that emits light by applying a voltage between a transparent electrode and a counter electrode, and a solution or dispersion of a red, green, or blue functional material is applied to a partition wall at a predetermined position. 3 is formed by adhering onto the transparent functional layer 2 inside. Examples of the forming method include a relief printing method, an offset printing method, and a reverse offset printing method, but are not limited thereto.

  FIG. 2 shows an outline of the organic substrate inspection apparatus according to the present invention.

  An organic EL substrate 10 that is an inspection object is placed on a stage 11 that is a sample moving means. The stage 11 can move in the XY directions so that the entire effective range of the organic EL substrate 10 can be imaged by the imaging unit 8.

  Holes for inserting positioning pins may be formed in a regular arrangement in advance on the surface of the stage 11 so that the mechanism can be easily positioned even when the shape or size of the organic EL substrate 10 changes. In addition, the surface of the stage 11 is coated with a color that does not reflect the light from the light irradiation unit 9 as much as possible, is subjected to a matting process, and further has a non-slip function that does not cause displacement when the stage is moved. It is preferable to provide a material.

  Although the charge coupled device (Charge Coupled Device) is used for the image pickup unit 8 which is an image pickup means, the present invention is not limited to this. An LED light source having a light emission peak in the vicinity of 850 nm is used for the light irradiation unit 9 that is a light irradiation means, but is not limited to this. Further, the positional relationship between the imaging unit 8, the light irradiation unit 9, and the organic EL substrate 10 is arranged as shown in FIG. 2B, and the regular reflection of the incident light is inclined by 45 ° with respect to the organic EL substrate 10. Although it is an arrangement to capture, it is not limited to this arrangement.

  The reflected light from the organic EL substrate 10 obtained in the imaging unit 8 is converted into an electric signal and transmitted to the image processing unit 7 which is an image processing unit. The image processing unit 7 performs the following data processing to extract defects present on the organic EL substrate 10.

FIG. 3 shows a line profile of luminance values when imaging is performed with the optical arrangement shown in FIG. The luminance value at the position indicated by the arrow 12 in FIG. 3A is plotted from 0 to 255 (that is, in 256 steps). Referring to the case with the organic light emitting layer, it can be seen that the brightness is different between the partition 13 without the organic light emitting layer and the organic light emitting layer 14 (about 50 at the maximum). Thereby, if an appropriate threshold value is used, the partition wall 13 and the organic light emitting layer 14 can be discriminated by the luminance value.

  Further, comparing the line profiles with and without the organic light emitting layer, it can be seen that the luminance is different in the area of the organic light emitting layer 14 (up to about 30). As a result, even in the organic light emitting layer 14 having transparency to visible light, if the 45 ° specular reflection arrangement and the 850 nm single wavelength light source are used, it is possible to accurately detect the omission of the organic light emitting layer.

  Next, an outline of the cross comparison process will be described. As shown in FIG. 4, four points in the up / down / left / right directions are set for the target pixel 16. Since cells of the same color are lined up in the vertical direction, the points that are repeatedly separated by the pitch Pn are set as the comparison pixels 15 and 18 with respect to the nearest neighbor cell. Further, since one display pixel is composed of three cells (red, green, and blue) with respect to the left-right direction, the points that are repeatedly separated by the pitch Pm are referred to as comparison pixels 17 and 19.

  A total of five luminances of the target pixel 16 and the comparison pixels 15, 17, 18, and 19 are sorted, and the difference between the luminance value of the target pixel and the median value is performed. By replacing the luminance value of the target pixel 16 with a value obtained by adding an appropriate offset value (for example, 128) to the calculated difference value, the repetitive pattern is erased as shown in FIG. Appears as a feature point.

  Only the defect to be detected can be extracted by using the relationship between the substrate portion and the luminance value and the cross comparison process described above. Detailed processing contents will be described with reference to the flowchart of FIG.

  First, the organic EL substrate 10 is imaged by the imaging unit 8 of the organic EL inspection apparatus of FIG. 2, and the obtained image data is transferred to the image processing unit 7 (step S1 of FIG. 5). At this time, the luminance value of each pixel of the image data is generally quantized as digital data of about 4 bits to 10 bits, and in this embodiment, takes the form of 8 bits (0 to 255).

  As shown in FIG. 6, the pixel of interest 16 is set with the pixel (1, 1) coordinate obtained from the captured image as the starting point (step S2 in FIG. 5). Here, the coordinates (1, 1) in FIG. 6 are the coordinates of the image data captured at the earliest time of imaging within the effective inspection area, and (m, n) is the image captured at the latest time. Indicates the coordinates of the data.

  Next, the comparison pixel is set to a pixel that is one pattern pitch away from the target pixel, that is, a pixel having a (10, 1) coordinate (step S3 in FIG. 5). In the figure, only the comparison pixel positioned in the right direction with respect to the target pixel is shown, but actually, four comparison pixels positioned in the vertical and horizontal directions are set. At the end of the repetitive pattern, the setting of comparison pixels may become inappropriate. In this case, processing such as reducing the number of comparison pixels may be performed.

  Next, the area of the target pixel 16 is determined (step S4 in FIG. 5). As shown in FIG. 3B, the brightness values of the partition wall 3 and the organic light emitting layer 1 are greatly different. Therefore, by setting a threshold value B between them, the target pixel 16 can be connected to the partition wall 3 or the organic light emitting layer 1. It is possible to determine which position is located. For the area determination, a total of five luminance values of the target pixel 16 and the comparison pixels 15, 17, 18, and 19 are used. Each area is compared with the threshold B to determine the area. Therefore, the area occupying the majority is determined as the area where the target pixel 16 is located (step S5 in FIG. 5). This process can prevent erroneous determination when a defect exists.

When the target pixel 16 is determined to be the partition wall 3 (step S6 in FIG. 5), a comparison process is performed between the target pixel 16 and the comparison pixels 15, 17, 18, and 19 (step S8 in FIG. 5). A pixel exceeding the threshold value D1 is determined as a defect candidate (step S12 in FIG. 5). When the detected defect is a black defect (step S14 in FIG. 5), the difference value is compared with the threshold E, and when the threshold E is exceeded (step S17 in FIG. 5), foreign matter on the partition wall 3 is detected. It is determined that The reason why the threshold value E is provided is that there may be a coating residue of the organic light emitting layer 1 on the partition wall 3 and a film thickness difference of the coating residue may be detected as a black defect. Since the luminance values of the two are greatly different, the threshold value E can be used for discrimination.

  When the target pixel 16 is determined as the organic light emitting layer 1 (step S7 in FIG. 5), a comparison process is performed between the target pixel 16 and the comparison pixels 15, 17, 18, and 19 (step S9 in FIG. 5). A pixel whose difference value exceeds the threshold value D2 is determined as a defect candidate. If the detected defect candidate is a white defect, it is determined that the organic light emitting layer 1 is missing (step S15 in FIG. 5), and if it is a black defect, it is determined as a foreign matter on the organic light emitting layer 1 (step in FIG. 5). S16).

  By repeating the above process (step S20 in FIG. 5), it is possible to determine the mode of the defect detected in the entire substrate and extract only the defect to be detected.

  According to the organic EL substrate inspection apparatus and inspection method of the present invention, among the defects existing on the organic EL substrate, it is possible to discriminate and detect foreign matter on the partition walls and foreign matter / missing on the organic light emitting layer. Become.

DESCRIPTION OF SYMBOLS 1 ... Organic light emitting layer 2 ... Transparent functional layer 3 ... Partition 4 ... TFT element 5 ... Transparent electrode layer 6 ... Translucent substrate 7 ... Image processing part 8 ... Image pick-up part 9 ... Light irradiation part 10 ... Organic EL substrate 11 ... Stage 12 ... Line profile direction 13 ... Partition part profile 14 ... Organic light emitting layer part profile 15 ..Comparison pixel 16 ... Pixel of interest 17 ... Comparison pixel 18 ... Comparison pixel 19 ... Comparison pixel 20 ... Defect

Claims (8)

An inspection apparatus for an organic electroluminescence (organic EL) substrate having a transparent electrode layer formed on a TFT substrate, a partition wall arranged on the transparent electrode layer, and an organic light emitting layer,
A sample moving means for placing the organic EL substrate and moving it on the XY plane;
A light irradiation means for irradiating illumination light to the organic light emitting layer side of the organic EL substrate;
Imaging means for converting reflected light from the organic EL substrate into an electrical signal and converting it into data;
An organic EL substrate inspection apparatus comprising: image processing means for performing arithmetic processing on image data obtained by the imaging means, wherein the image processing means performs the following processing. [A] The comparison pixel is a point separated from the target pixel of the image data by the repetitive pitch of the organic EL substrate, and four comparative pixels are set in the vertical and horizontal directions with respect to the target pixel.
[B] Referring to the luminance values of the target pixel and the comparison pixel, if there are three or more pixels having luminance values exceeding a preset threshold value B, the target pixel is determined as a partition wall and exceeds the threshold value B When the number of comparison pixels having a luminance value is two or less, the target pixel is determined as the organic light emitting layer portion.
[C] Sort five luminance values of the target pixel and the comparison pixel, and perform a difference between the luminance value of the target pixel and the sorted median value.
[D] A threshold value D for the difference value is set separately for each of the partition wall and the organic light emitting layer, and when the target pixel is a partition wall, the target pixel exceeding the threshold D1 in the partition wall When the defect is a partition wall defect and the target pixel is an organic light emitting layer part, the target pixel exceeding the threshold D2 in the organic light emitting layer part is determined as an organic light emitting layer part defect.   2. The organic EL substrate inspection apparatus according to claim 1, wherein an emission spectrum of the light irradiation means has a single wavelength, and preferably has an emission peak in the vicinity of 800 nm to 850 nm.   Of the reflected light from the organic EL substrate, only specularly reflected light is converted into data by the imaging means, and preferably the light irradiation means and the imaging means are inclined by 40 ° to 45 ° from a vertical plane with respect to the organic EL substrate. The organic EL substrate inspection apparatus according to claim 1, wherein the organic EL substrate inspection apparatus is arranged.   In the image processing means, the threshold value D2 is set to positive and negative in advance, the pixel of interest exceeding the positive threshold is classified as a white defect, and the pixel of interest exceeding the negative threshold is classified as a black defect, It is determined that white defects detected in the organic light emitting layer portion are derived from missing of the organic light emitting layer, and black defects are derived from foreign matters existing on the organic light emitting layer, and black defects detected in the partition wall portion are detected. 4. The organic EL substrate according to claim 1, wherein among the defects, the black defect exceeding a preset threshold E is determined to be derived from a foreign substance existing on the partition wall. Inspection device. A method for inspecting an organic electroluminescence (organic EL) substrate having a transparent electrode layer formed on a TFT substrate, partitions arranged on the transparent electrode layer, and an organic light emitting layer,
A sample moving means for placing the organic EL substrate and moving it on the XY plane;
A light irradiation means for irradiating illumination light to the organic light emitting layer side of the organic EL substrate;
Imaging means for converting reflected light from the organic EL substrate into an electrical signal and converting it into data;
An organic EL substrate inspection method, wherein the image processing means performs the following processing using an image processing means that performs arithmetic processing on image data obtained by the imaging means.
[A] The comparison pixel is a point separated from the target pixel of the image data by the repetitive pitch of the organic EL substrate, and four comparative pixels are set in the vertical and horizontal directions with respect to the target pixel.
[B] Referring to the luminance values of the target pixel and the comparison pixel, if there are three or more pixels having luminance values exceeding a preset threshold value B, the target pixel is determined as a partition wall and exceeds the threshold value B When the number of comparison pixels having a luminance value is two or less, the target pixel is determined as the organic light emitting layer portion.
[C] Sort five luminance values of the target pixel and the comparison pixel, and perform a difference between the luminance value of the target pixel and the sorted median value.
[D] A threshold value D for the difference value is set separately for each of the partition wall and the organic light emitting layer, and when the target pixel is a partition wall, the target pixel exceeding the threshold D1 in the partition wall is determined. When the defect is a partition wall defect and the target pixel is an organic light emitting layer part, the target pixel exceeding the threshold D2 in the organic light emitting layer part is determined as an organic light emitting layer part defect.   6. The organic EL substrate inspection method according to claim 5, wherein an emission spectrum of the light irradiation means has a single wavelength, and preferably has an emission peak in the vicinity of 800 nm to 850 nm.   Of the reflected light from the organic EL substrate, only specularly reflected light is converted into data by the imaging means, and preferably the light irradiation means and the imaging means are inclined by 40 ° to 45 ° from a vertical plane with respect to the organic EL substrate. The organic EL substrate inspection method according to claim 5, wherein the organic EL substrate inspection method is arranged.   In the image processing means, the threshold value D is set separately for each positive and negative, and the target pixel exceeding the positive threshold is classified as a white defect, and the target pixel exceeding the negative threshold is classified as a black defect. The white defects detected in the organic light emitting layer portion are determined to be derived from missing of the organic light emitting layer, and the black defects are determined to be derived from foreign matters existing on the organic light emitting layer, and are detected in the partition wall portion. The organic defect according to claim 5, wherein among the black defects, the black defect that exceeds a preset threshold value E is determined to be derived from a foreign substance existing on the partition wall. EL substrate inspection method.

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