JP5304382B2 - Electrophoresis type front plate inspection apparatus and method - Google Patents

Description

  The present invention relates to an electrophoretic front plate inspection apparatus and method for an electrophoretic front plate which is a main component of an electronic paper display.

  Various methods are being developed as technologies for realizing an electronic paper display having high visibility, rewritable characteristics and low power consumption. A display using an electrophoretic phenomenon uses a phenomenon in which charged particles in a solvent move by an electric field. As one of the techniques, a microcapsule type electrophoresis system has been put into practical use. In this method, positively and negatively charged white particles and black particles are placed in a microcapsule filled with a transparent liquid, and an image is formed by pulling up each particle to the display surface by applying an external voltage. Since the microcapsule size is as small as φ several tens μm to several hundreds μm, when the microcapsules are dispersed in a transparent binder, they can be coated like ink. This ink is called electronic ink because an image can be drawn by applying a voltage from the outside. When this electronic ink is coated on a transparent film on which a transparent electrode layer is formed and bonded to a substrate on which an electrode circuit for driving an active matrix is formed, an active matrix display panel can be formed. Here, a component in which electronic ink is coated on a transparent film on which a transparent electrode is formed is called a “front plate”, and a substrate on which an active matrix driving electrode circuit is formed is called a “back plate”. Various defects occur in the front plate. However, if the defect inspection is performed after the two are bonded together, a loss of disposal of expensive normal products of the back plate occurs due to the defect of the front plate. Therefore, a defect inspection at the part stage of the front plate is strongly desired.

  However, the front plate alone has a problem that normal operation of the microcapsule cannot be confirmed because there is an electrode for applying a voltage to the microcapsule only on one side. In order to solve this problem, a conductive film is used as a peeling film for the front plate. That is, by using the conductive film as the second electrode as an alternative to the back plate, the front plate and the expensive back plate can be bonded to each other between the transparent electrode on the front plate and the conductive film. A voltage can be applied to the particles to move the particles in the microcapsules.

  However, among the defects in the front plate, there is a defect that should be called a response abnormality defect in which the response to the applied voltage is faster or slower than the normal part. The abnormal response defect is hardly visible when the front panel display is in a saturated state such as full black or full white, but appears as local unevenness while the display state of the front panel is changing or during intermediate color display. Since it is not easy to detect such a defect with an inspection device, human visual inspection, that is, sensory inspection is performed. However, in the sensory test that depends on human sensory, variations in determination results by the inspector cannot be avoided. In particular, the response abnormality defect is a defect derived from a difference in responsiveness to the applied voltage, and the luminance difference between the response abnormality defect portion and the normal portion is not always constant. Furthermore, even if it is visible at a certain timing, it is a defect having a property that the luminance difference from the normal part is small. Therefore, the sensory inspection of the response abnormality defect has a large subjective factor and tends to cause a determination variation.

  Therefore, in order to establish a physical and quantitative evaluation method and improve inspection accuracy and reliability, there is an increasing demand for sensory inspection as an image inspection apparatus.

In addition, electronic paper displays tend to be low in price due to market competition, and in order to cope with this, a part of the roll-to-roll continuous production method has been adopted.
For this reason, when coating is performed with a coater, streaky coating unevenness often occurs in the coating direction. Further, when the accuracy of the coater fluctuates, streaky coating unevenness occurs in a direction orthogonal to the coating direction.
Such streaky coating unevenness appears as display unevenness after making an electronic paper display panel.

  For the inspection of streak-like unevenness, two-dimensional luminance data is integrated in the application direction and the direction orthogonal to the application direction, the moving average of the integrated data is calculated, and the difference between the integrated data and the integrated moving average data There is an inspection method in which the difference data is calculated to be a threshold value set in advance and the above data is determined to be streaky irregularities. (See Patent Document 1)

  However, this method cannot detect light streak-like unevenness that occurs due to abnormal drive speed. When a point defect with a large luminance level is included, there is a problem that it is determined as a streak defect.

  Regarding the inspection method of the electronic paper display, among the plurality of pixels surrounding the target pixel, the plurality of average values excluding the maximum value and the minimum value are calculated, and after calculating the difference between the target pixel and the average value, There is an inspection method for determining that data exceeding a set threshold value is uneven. (See Patent Document 2)

  However, in this method, when determining streak-like unevenness, there are a plurality of uneven pixels in the pixel surrounding the pixel of interest, and the normal value is different from the average value and the surrounding values because the drive speed is abnormal. Pale streaky unevenness that occurs can not be detected. When a point defect with a large luminance level is included, there is a problem that it is determined as a streak defect.

JP-A-2005-77181 JP2008-86406

  The present invention has been made in view of the above problems, and the problem is to display and capture an image in which a response abnormality defect is noticeable, and to detect a response abnormality defect included as a local streak-like unevenness in the captured image. An object of the present invention is to provide an electrophoretic front plate inspection apparatus and method for extracting with high accuracy.

  The present invention has been made to solve such a problem, and the invention according to claim 1 applies a voltage to white and black display materials charged in different polarities constituting an electrophoretic front plate. And an electric signal output means for driving, an imaging means for imaging the display surface of the electrophoretic front plate, an image digitizing means for digitizing an image captured by the imaging means, and digitization by the image digitizing means Image processing means for processing the processed image, inspection result output means for performing a comparison operation based on the processing result of the image processing means and outputting the inspection result of the front plate, the captured image, and processing by the image processing means In an electrophoretic front plate inspection apparatus comprising an image and a monitor display means for outputting an inspection result by the inspection result output means, the imaging means includes the electric signal By driving the force means, the white display material is moved to the display surface side of the electrophoretic front plate and saturated, and then the black display material is moved to the display surface side to display black from white display. The first state in which the gray state during the transition to is captured is imaged, and the white display material is moved to the display surface side from the saturated state by moving the black display material to the display surface side. A second state that is in the middle of a transition from black display to white display by moving is captured, and the image processing means captures the captured image in the first state and the captured image in the second state. Is calculated for each pixel arranged two-dimensionally, and the obtained two-dimensional data of the difference is integrated for each pixel column or pixel row in the vertical and horizontal directions to obtain the first one-dimensional data in the vertical and horizontal directions. And the first one-dimensional data in the vertical and horizontal directions A moving average operation is performed on each of them to calculate second one-dimensional data, a difference operation between the first one-dimensional data in the vertical direction and the second one-dimensional data, and a first operation in the horizontal direction. A difference between the first one-dimensional data and the second one-dimensional data, and the inspection result output means performs a comparison operation between a predetermined threshold value and the difference calculation result value in the vertical direction; , By comparing the predetermined threshold value and the difference calculation result value in the horizontal direction to determine the presence or absence of stripe-shaped unevenness in the vertical direction and the horizontal direction, and outputting the result .

  According to a third aspect of the present invention, the white display material is driven by an electric signal output means for applying a voltage to the white and black display materials charged to different polarities constituting the electrophoretic front plate. A first state in which a gray state is maintained during the transition from white display to black display by moving the black display material to the display surface side from the saturated state by moving to the display surface side of the electrophoretic front plate. In addition, when the black display material is moved to the display surface side and saturated, the white display material is moved to the display surface side to transition from black display to white display. The difference between the image capturing step for capturing the second state holding the gray state, the image capturing the first state, and the image capturing the second state is calculated for each pixel arranged in two dimensions. The vertical direction of the two-dimensional data of the difference obtained The first one-dimensional data in the vertical direction and the horizontal direction is calculated by integrating each pixel column or pixel row in the horizontal direction, and moving average calculation is performed for each of the first one-dimensional data in the vertical direction and the horizontal direction. To calculate second one-dimensional data, calculate a difference between the first one-dimensional data in the vertical direction and the second one-dimensional data, the first one-dimensional data in the horizontal direction, and the second one An image processing step for performing a difference calculation of one-dimensional data, a comparison operation between a predetermined threshold and the difference calculation result value in the vertical direction, and a predetermined threshold and the horizontal direction And a step of comparing and calculating the difference calculation result value to determine whether or not there are streaky irregularities in the vertical direction and the horizontal direction, and outputting the result.

  According to the present invention, in the inspection of the electrophoretic front plate, the front plate is driven and imaged with a drive signal in which the response abnormal defect is conspicuous, and the response abnormal defect included as streaky unevenness is calculated by processing the captured image. It is possible to detect with high accuracy without depending on the skill level of the worker.

It is a figure which concerns on the display material microcapsule used as the test object of this invention. It is a figure which concerns on the display material microcapsule used as the test object of this invention. It is a figure of the electrophoresis type front board used as the inspection object of the present invention. It is an apparatus block diagram of this invention. It is a flowchart which shows the test | inspection method procedure of this invention. It is a drive waveform pattern figure concerning the present invention. It is a brightness | luminance schematic diagram of the response abnormal defect at the time of displaying the electrophoresis front plate based on this invention in gray from white. It is a brightness | luminance schematic diagram of the response abnormal defect at the time of displaying the electrophoretic front plate based on this invention gray from black. It is a figure which shows the difference calculation result which concerns on this invention. It is a flowchart which shows the image processing method procedure of this invention. It is an image by the drive waveform as described in this patent. It is an image by the drive waveform as described in this patent. It is an image of the difference calculation result described in this patent. It is the accumulation | aggregation result of the vertical direction as described in this patent. It is a result of the moving average described in this patent. It is the result of the difference described in this patent. It is the result of the defects described in this patent. It is the captured image of patent document 1. This is the result of integration in the column direction described in Patent Document 1. This is a result of the defect described in Patent Document 1. It is an image by the drive waveform of patent document 2. FIG. It is an image by the drive waveform of patent document 2. FIG. 10 is an image of an abnormal response defect due to a drive waveform described in Patent Document 2.

  Hereinafter, embodiments of the present invention will be described in detail while comparing with the inventions described in Patent Documents 1 and 2.

First, an example in which a portion including streaky unevenness based on the content of Patent Document 1 is inspected will be described.
FIG. 18 shows the luminance level of each pixel when imaged by a CCD camera. This pattern is assumed to be composed of stripe-like unevenness to be detected in the vertical direction of the central portion, unevenness scattered around the periphery, and non-driven inspection portions.
Based on the contents of Patent Document 1, FIG. 19 shows the result of calculating the luminance level of each pixel assumed to be imaged by a CCD camera in the vertical direction.
As a result of designating the threshold value at the center of the high and low levels (shown in FIG. 20), streaky uneven portions can be detected, but point defect portions are also detected as streaky uneven portions. Only streaky irregularities cannot be detected.

Next, based on the content of Patent Document 2, an example in the case where a streaky uneven portion is inspected will be described.
After white display (drive waveform pattern 3 in FIG. 6), a pulse voltage for black display is applied, and gray is displayed in the drive waveform pattern (drive waveform pattern 5 in FIG. 6) with a half pulse width that is saturated multiple short pulses. FIG. 21 shows a response abnormality defect image of the electrophoretic front plate. Furthermore, after black display (FIG. 6 drive waveform pattern 1), a pulse voltage for white display is applied, and the drive waveform pattern (drive waveform pattern 6 in FIG. 6) has a half pulse width that saturates a plurality of short pulses. The displayed abnormal response defect image of the electrophoretic front plate is shown in FIG.
FIG. 23 shows an image of the difference between the image transitioning from white to black display and the image transitioning from black to white display. As a result, streaky unevenness can be detected, but scattered unevenness is also detected, and as a result, only streaky unevenness cannot be detected.

Furthermore, based on this invention, an example at the time of test | inspecting a stripe-shaped unevenness is shown.
After white display (drive waveform pattern 3 in FIG. 6), a pulse voltage for black display is applied, and gray is displayed in the drive waveform pattern (drive waveform pattern 5 in FIG. 6) with a half pulse width that is saturated multiple short pulses. FIG. 11 shows an abnormal response image of the electrophoretic front plate. Furthermore, after black display (FIG. 6 drive waveform pattern 1), a pulse voltage for white display is applied, and the drive waveform pattern (drive waveform pattern 6 in FIG. 6) has a half pulse width that saturates a plurality of short pulses. The response abnormality defect image of the displayed electrophoresis type front plate is shown in FIG.
The difference between the image transitioning from white to black display and the image transitioning from black to white display is calculated. The image is shown in FIG. FIG. 14 shows the result of integrating the images in the vertical direction. The moving average calculation is performed on the result integrated in the vertical direction. The result is shown in FIG. The difference between the result of integration in the vertical direction and the result of the moving average calculation is calculated. The result is shown in FIG. If a threshold value is set at the center of the maximum and minimum brightness differences, only streaky uneven portions can be detected in layers as shown in FIG.

  Next, examples of the present invention will be described in detail.

(Electrophoretic front plate)
First, an electrophoretic front plate to be inspected according to the present invention is described.

(Display material)
The electrophoretic microcapsule that is the core of the display material is composed of titanium oxide having an average particle diameter of 3 μm coated with a polyethylene resin that is negatively charged in a solution in a tetrachloroethylene solvent and an alkyltrimethylammonium chloride (R) that is positively charged in the solution. A dispersion is prepared in which each colored pigment of black pigment particles (13Bk) surface-treated with (CH3) 3N + Cl-, R is an alkyl group) is dispersed.
Each dispersion was mixed with water adjusted to 40 ° C. and an aqueous solution containing gelatin and sodium dodecyl sulfate as an emulsifier, and stirred with a homogenizer while maintaining the liquid temperature at 40 ° C., and O / W (oil-in-water type) An (oil-in-water) emulsion is obtained.
Next, each O / W (oil-in-water emulsion obtained) and an aqueous solution containing gum arabic mixed with water adjusted to 40 ° C. were mixed using a disper, and the liquid temperature of each solution was The pH of the solution was adjusted with acetic acid while maintaining the temperature at 40 ° C., and a microcapsule shell (14) was formed by coacervation, each liquid temperature was adjusted to 5 ° C., formalin solution was added and sodium hydroxide was used. Then, the pH of the solution was adjusted, and the temperature of each solution was adjusted to 50 ° C. while stirring to cure the microcapsule shell, and the diameter of the microcapsules enclosing the dispersion in which white and each color particle were dispersed was screened. To approximately 40 μm (see FIG. 1).

(Preparation of electrophoresis microcapsule coating solution)
The obtained electrophoretic microcapsules and a polyurethane resin solution (Nipporan 5037, manufactured by Nippon Polyurethane Industry Co., Ltd.) are mixed to prepare an electrophoretic microcapsule coating liquid (see FIG. 2).

(substrate)
Transparent insulating base materials are glass, plastic (styrene resin, cellulose, cresol resin, epoxy resin, melamine resin, polyamide, polycarbonate, polyethylene, acrylic resin, phenol resin, polyisobutylene, methacrylic resin, acetal resin, polypropylene, polystyrene, ethylene Resin, polyurethane, vinyl resin, poval, vinylidene resin, silicone resin, urea resin, polyester resin, fluororesin, cycloolefin polymer), but is not limited thereto.

(electrode)
As the transparent conductive film, tin oxide, indium oxide, zinc oxide, conductive polymer, or the like can be used.
The transparent conductive film is formed on the surface of the substrate by a known method such as vapor deposition, sputtering, electrodeposition, coating or printing.

(adhesive)
Although it is a urethane type adhesive, it is not limited to this.
(Conductive release film)
A film in which a back conductive layer such as aluminum is laminated on one surface of a film by a known method such as vapor deposition.

(Electrophoretic front plate)
An electrode is laminated on a substrate, and an electrophoretic microcapsule coating liquid to be a display material is coated on the electrode layer so that the microcapsules are arranged in one layer, and the display material surface and the back conductive surface are An electrophoretic front plate (FIG. 3), which is an inspection object of the present invention, is formed by laminating and bonding with an adhesive.

  FIG. 4 is a configuration diagram of an electrophoretic front plate inspection apparatus for inspection of abnormal response defects according to the present invention.

In the figure, an output signal (hereinafter referred to as a drive waveform) through an electrical signal generator (31) based on an instruction from a personal computer (PC) (36) is an electrical object to be inspected through a probing device (32). It is sent to the electrophoresis type front plate (33). The front plate (33) to which the drive waveform is applied displays black and white and intermediate gray according to the drive waveform pattern. After the display of the front plate (33) is completed, the camera (34) takes an image of the front plate (33) in accordance with an instruction from the personal computer (PC) (36). (35) is an image input device connected to the camera (34). An image captured in accordance with an instruction from the personal computer (PC) (36) is captured as a digital image into the personal computer (PC) (36) via the image input device (35). The captured image is subjected to calculation for image processing and arithmetic processing by the same personal computer (PC) (36). (37) is a monitor that displays a captured image captured by the camera (34), an inspection result, and the like.
FIG. 5 is a flowchart showing the electrophoresis type front plate inspection method according to the embodiment of the present invention. The inspection method according to the embodiment of the present invention includes driving the electrophoretic front plate from white display to gray display (51), capturing an image to be inspected (captured image) A (52), black on the electrophoretic front plate. This is performed by a series of steps of driving from display to gray display (53), capturing of an inspection image A (54), image processing (55), inspection calculation processing (56), and inspection result monitor display (57). Hereinafter, the contents of each step will be described in the order of steps.

(Inspection image capture) (51, 52, 53, 54)
By installing an electrophoretic front plate on the probing device (33), the electrode and the back conductive layer of the conductive film are connected to a state where electricity can be passed.

  An example of the probing device will be described below. The front plate is placed on the inspection plate of the inspection device. The inspection plate is made of an insulating resin material. A first probe and a second probe incorporating springs are attached to the inspection plate. By lowering the glass plate in parallel from above the front plate by an air cylinder or an electric motor drive, the first probe and the second probe are electrically connected to the electrode and the conductive film of the front plate, respectively. Contact.

(Drive waveform)
In order to display the gray image shown in FIG. 7, the driving waveform for displaying the electrophoretic front plate in white, the driving waveform for displaying the electrophoretic front plate in gray after the white display, and the gray image shown in FIG. For displaying the electrophoretic front plate in black, and a driving waveform for displaying the electrophoretic front plate in gray after the black display.

  The driving waveform for displaying the electrophoretic front plate in white is applied with a pulse voltage for displaying white as shown in driving waveform pattern 3 in FIG.

  The driving waveform for displaying the electrophoretic front plate in white and then gray is a pulse voltage for black display as shown in the driving waveform pattern 5 in FIG. And then return to 0V.

  The driving waveform for displaying the electrophoretic front plate in black is returned to 0 V when a pulse voltage for displaying black is applied as shown in driving waveform pattern 1 in FIG.

  The drive waveform for displaying the electrophoretic front plate in gray after black display is a pulse voltage for white display as shown in the drive waveform pattern 6 in FIG. And then return to 0V.

(Display and imaging procedure)
In addition, there are abnormal response defects that are faster and slower than the surroundings.
When gray display is performed in the black direction from white display, defects appear on the front plate as shown in the image diagram of FIG. FIG. 7B shows the luminance level on the SS ′ line across the response abnormality defect in FIG.

  Further, when the gray display is performed in the white direction from the black display, a defect appears on the front plate as shown in the image diagram of FIG. FIG. 8B shows the luminance level on the S-S ′ line crossing the response abnormality defect of FIG.

  The display states of these two types of front plates are captured as images.

  The procedure is as follows. First, the electrophoretic front plate is displayed in black according to the drive waveform (drive waveform pattern 3) output instruction of the personal computer (PC) (36), and then the personal computer (PC) (36). ) Is displayed in response to a drive waveform (FIG. 6 drive waveform pattern 5) output instruction. Thereafter, in response to an imaging instruction from the personal computer (PC) (36), the camera captures the digital image A and captures the digital image A into the personal computer (PC) (36). Further, in response to a drive waveform (drive waveform pattern 1) output instruction of the personal computer (PC) (36), the electrophoretic front plate is displayed in black, and then the drive waveform of the personal computer (PC) (36) ( FIG. 6 Drive waveform pattern 6) Gray is displayed in response to an output instruction. Thereafter, in response to an imaging instruction from the personal computer (PC) (36), the camera captures the digital image B and captures the digital image B into the personal computer (PC) (36).

(Image processing) (55)
Next, FIG. 10 shows a flow showing an image processing method procedure.
After the image is captured by the personal computer (PC) (36), the luminance value of each pixel of the digital image A (hereinafter referred to as A (i, j)) and the luminance value of each pixel of the digital image B (hereinafter referred to as B) (Denoted as (i, j)) (see FIG. 9). A difference result (hereinafter referred to as C (i, j)) between each pixel of the obtained image A and image B is represented by C (i, j) = A (i, j) −B (i, j). The The difference results C (i, j) are integrated in the vertical and horizontal directions. The result of integration for each vertical column (hereinafter referred to as D (i)) is expressed as D (i) = C (i, 1) + C (i, 2) +... + C (i, j). The result of integration for each horizontal row (hereinafter referred to as E (j)) is expressed as E (j) = C (1, j) + C (2, j) +... + C (i, j). By calculating the difference between the images and then accumulating in the vertical and horizontal directions, streaky irregularities of the response abnormal defect are more emphasized and can be clearly identified.

(Inspection calculation processing) (56)
(Binarization processing)
The moving average of the vertical moving average amount n and the horizontal moving average amount m specified in advance in the vertical integrated result D (i) and the horizontal integrated result E (j) obtained in the image processing (55). Perform the operation. The resulting vertical moving average result (hereinafter referred to as F (i)) is F (i) = (D (i−n) +... + D (i) +... + D (i + n)) / (N + 1). The horizontal moving average result (hereinafter referred to as G (i)) is G (j) = (E (j−m) +... + E (j) +... + E (j + m)) / (m + 1) expressed.

A difference between the vertical integration result D (i) and the moving average result F (i) in the vertical direction is obtained. The result (hereinafter referred to as H (i)) is represented by H (i) = | D (i) −F (i) |. The difference between the lateral integration result E (j) and the lateral moving average result G (j) is obtained. The result (hereinafter referred to as I (j)) is represented by I (j) = | E (j) −G (j) |.
As shown in FIGS. 19 and 20, binarization processing is performed with a threshold value α1 that detects vertical stripe-like unevenness that is a response abnormality having a different speed from the surroundings. As a result, J (i) = 1 (where H (i)> = α1) and J (i) = 0 (where H (i) <α1). Also, binarization processing is performed with a threshold value α2 that detects horizontal streaky unevenness that causes response abnormalities having different speeds from the surroundings. As a result, K (j) = 1 (where I (j)> = α2) and K (j) = 0 (where I (j) <α2).
(Labeling process)
The vertical streak-like unevenness J (i) and the horizontal streak-like unevenness K (j) extracted in the binarization process are labeled for each detected defect, and its coordinate position, line width, etc. A quantitative value is calculated.

(Pass / fail judgment)
Based on the quantitative value calculated in the labeling process, the pass / fail determination of the subject to be inspected is performed.

(Monitor display) (57)
The pass / fail judgment result is displayed on the monitor (17).

  As described above, according to the embodiment of the present invention, the response speed abnormality appearing on the electrophoretic front plate is repeated a plurality of times with a short pulse width waveform such as the drive waveform pattern 5 or 6 in FIG. In the electrophoretic front plate driving method, the response difference of the response abnormality defect is accumulated and displayed, and the inspection calculation process of FIG. 10 can be performed to more clearly detect the stripe abnormality of the response abnormality.

DESCRIPTION OF SYMBOLS 4 ... Electrophoresis microcapsule 12 ... White particle 13 ... Black colored particle 20 ... Binder solution 31 ... Electric signal generator 32 ... Probing device 33 ... Electrophoresis type front plate 34 ... Camera 35 ... Image input device 36 ... Personal computer 37 ... Monitor 61 ... Pixel of interest 62 ... Pixel group separated by n pixels from the pixel of interest 81 ... Luminance level of response abnormal defect by front plate driving method based on Patent Document 2 82 ... Luminance of response abnormal defect by front plate driving method based on the present invention Level 83: Threshold for detecting abnormal response defects

Claims (4)

An electric signal output means for driving by applying a voltage to white and black display materials charged to different poles constituting the electrophoretic front plate; an imaging means for imaging the display surface of the electrophoretic front plate; An image digitizing means for digitizing an image captured by the imaging means, an image processing means for processing an image digitized by the image digitizing means, and a comparison operation based on a processing result of the image processing means, An electrophoretic front plate comprising test result output means for outputting a test result of the front plate, and a monitor display means for outputting the captured image, a processed image by the image processing means, and a test result by the test result output means. In inspection equipment,
From the state in which the imaging means moves the white display material to the display surface side of the electrophoretic front plate and is saturated by driving the electric signal output means, the black display material is moved to the display surface side. The first state in which the gray state is maintained during the transition from the white display to the black display is imaged, and the black display material is moved to the display surface side to saturate the white state. The display material is moved to the display surface side, and an image of a second state in which a gray state in the middle of transition from black display to white display is maintained is obtained.
The image processing means calculates the difference between the captured image in the first state and the captured image in the second state for each pixel arranged in a two-dimensional manner, and the obtained two-dimensional data of the difference as the vertical direction The first one-dimensional data in the vertical direction and the horizontal direction is calculated by integrating each pixel column or pixel row in the horizontal direction, and moving average calculation is performed for each of the first one-dimensional data in the vertical direction and the horizontal direction. And calculating second one-dimensional data, calculating a difference between the first one-dimensional data in the vertical direction and the second one-dimensional data, the first one-dimensional data in the horizontal direction, and the second The difference calculation of the one-dimensional data of
The inspection result output means compares and calculates a predetermined threshold value and the difference calculation result value in the vertical direction, and determines the predetermined threshold value and the difference calculation result value in the horizontal direction. By comparing and calculating, the presence or absence of streaky unevenness in the vertical direction and horizontal direction is determined and output,
An electrophoretic front plate inspection apparatus characterized by the above. In the first state, the black display material is applied after the electric signal output means applies a voltage having a pulse width at which the white display material moves to the display surface side of the electrophoretic front plate and is saturated. Is a state in which the gray state is maintained by applying a voltage having a pulse width sufficiently shorter than a pulse width that is saturated by moving to the display surface side twice or more,
In the second state, the electric signal output means applies a voltage having a pulse width at which the black display material moves to the display surface side of the electrophoretic front plate and is saturated, 2. The electricity according to claim 1, wherein the gray state is maintained by applying a voltage having a pulse width sufficiently shorter than a pulse width saturated when the display material moves to the display surface side and is saturated. Electrophoretic front plate inspection device. The white display material is moved to the display surface side of the electrophoretic front plate by driving electric signal output means for applying a voltage to white and black display materials charged to different polarities constituting the electrophoretic front plate. The black display material is moved from the saturated state by moving to the display surface side, and a first state in which a gray state is maintained during the transition from white display to black display is captured. The second state in which the gray state in the middle of transition from the black display to the white display is maintained by moving the white display material to the display surface side from the saturated state by moving the display material to the display surface side. An image imaging step for imaging;
The difference between the image picked up in the first state and the image picked up in the second state is calculated for each two-dimensionally arranged pixel, and the two-dimensional data of the obtained difference is calculated in the vertical and horizontal directions. The first one-dimensional data in the vertical direction and the horizontal direction is calculated for each column or pixel row, and the moving average calculation is performed on each of the first one-dimensional data in the vertical direction and the horizontal direction to obtain the second one. And calculating the difference between the first one-dimensional data in the vertical direction and the second one-dimensional data, and calculating the difference between the first one-dimensional data in the horizontal direction and the second one-dimensional data. An image processing step for performing a difference operation;
By comparing and calculating a predetermined threshold value and the difference calculation result value in the vertical direction, and by comparing and calculating a predetermined threshold value and the difference calculation result value in the horizontal direction, Including the inspection result output step of determining and outputting the presence or absence of streaky unevenness in the vertical direction and the horizontal direction,
An electrophoretic front plate inspection method characterized by the above. In the first state, the black display material is applied after the electric signal output means applies a voltage having a pulse width at which the white display material moves to the display surface side of the electrophoretic front plate and is saturated. Is a state in which the gray state is maintained by applying a voltage having a pulse width sufficiently shorter than a pulse width that is saturated by moving to the display surface side twice or more,
In the second state, the electric signal output means applies a voltage having a pulse width at which the black display material moves to the display surface side of the electrophoretic front plate and is saturated, 4. The electricity according to claim 3, wherein the gray state is maintained by applying a voltage having a pulse width sufficiently shorter than a pulse width saturated when the display material moves toward the display surface side. Electrophoretic front plate inspection method.

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