JP2000275596A - Cell inspection apparatus and cell inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cell inspection apparatus and cell inspection method capable of efficiently carrying out inspection with high reliability by detecting the objective region in spite of rough positioning in correspondence to production of a small quantity in diversified kinds when carrying out the defect inspection of liquid crystal products in the state before sticking of a polarizing plate. SOLUTION: Back light illumination 11 is put out and a liquid crystal cell substrate 8 is projected from above by coaxial vertical illumination 7, by which the image of the part coated with a sealing material is acquired when carrying out the defect inspection of the liquid cell substrate 8 before sticking of the polarizing plate with this cell inspection apparatus. The inspection is carried out after the objective region for the defect inspection of the intrinsically transparent liquid cell substrate 8 is confined by using the image. With regards to the other regions, the presence or absence of the defect is disregarded, by which a yield is improved and the processing time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically inspecting a liquid crystal product such as a liquid crystal display panel or the like (especially for small-quantity production of various kinds) by applying an image processing technique to inspect an optical system for defects or lighting. And a cell inspection method for determining an inspection area without changing a screen size or the like.

[0002]

2. Description of the Related Art In the production and inspection of a conventional liquid crystal display panel, it is important to determine the alignment direction, the positioning of a polarizing plate, and the like. The procedure of the defect inspection for this purpose is, for example, to detect a positioning mark or the like set on the substrate in each step, and to perform an inspection after assembling after position correction. The reason for taking such a procedure is that defects inside the liquid crystal injected therein are revealed only through the polarizing plate.

[0003] Further, when performing various kinds of small-quantity production, it is necessary to accurately perform polarization of an optical system, a positioning jig and the like at the time of setup change. For this reason, in a defect inspection before attaching a polarizing plate, an optical system in which a liquid crystal display panel is sandwiched between a pair of polarizing plates is constructed, and a defect is detected by changing the contrast between the defective portion and its surroundings. Therefore, an inspection apparatus and an inspection method provided with a mechanism for rotating the angle of a polarizing plate in an optical system have already been proposed.

[0004] Japanese Patent Application Laid-Open Nos. Hei 5-219535 and Hei 9-19935 describe related devices of this type.
No. 257641, and the like.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 5-219 is disclosed.
In the technique disclosed in Japanese Patent Application Laid-Open No. 535, the inspection target area is determined by performing a plurality of displays in the liquid crystal display panel.
When generating a display signal, it is necessary to maintain the reliability of the signal itself.

In the technique disclosed in Japanese Patent Application Laid-Open No. 9-257641, a mechanism for rotating the polarizing plate freely is provided. However, since the detection target in the inspection area is a product before the polarizing plate is attached. In addition, the detection target itself is transparent, and even in an optical system sandwiched by polarizing plates, a portion where liquid crystal is not injected is transparent. Therefore, when the rotation angle of the polarizing plate changes, the brightness also changes, and there is a possibility that an over-inspection may occur unless the inspection target area is limited.

SUMMARY OF THE INVENTION An object of the present invention is to improve such a problem and, when performing a defect inspection of a liquid crystal product before attaching a polarizing plate, to limit the target area of the defect inspection to produce various kinds in small quantities. Accordingly, it is an object of the present invention to provide a cell inspection apparatus and a cell inspection method capable of efficiently detecting a target area and performing a highly reliable inspection even with rough positioning.

[0008]

According to the first aspect of the present invention,
A liquid crystal is injected between transparent substrates, and a defect inspection of a liquid crystal cell substrate formed by sealing the injected liquid crystal within a display range with a sealant for bonding the transparent substrate is performed before attaching a polarizing plate to the liquid crystal cell substrate. A cell inspection apparatus to be performed in a state, comprising: holding means for holding a liquid crystal cell substrate; polarizing plates disposed above and below the liquid crystal cell substrate; and a polarizing plate disposed between the upper polarizing plate and the liquid crystal cell substrate. Illumination means for projecting the liquid crystal cell substrate, and imaging means arranged above the upper polarizing plate, for capturing reflected light from the sealant and acquiring an image of the sealant, comprising: It is characterized in that a defect inspection target area is determined based on an image.

According to a second aspect of the present invention, a liquid crystal is injected between transparent substrates provided with a transparent electrode pattern for liquid crystal display, and the injected liquid crystal is sealed within a display range by a sealant for bonding the transparent substrates. A cell inspection apparatus that performs a defect inspection of the liquid crystal cell substrate that has been performed before attaching a polarizing plate to the liquid crystal cell substrate, and a holding unit that holds the liquid crystal cell substrate;
A polarizing plate disposed above and below the liquid crystal cell substrate, and a first coaxial epi-illumination means disposed between the upper polarizing plate and the liquid crystal cell substrate and projecting a sealant for the liquid crystal cell substrate; A second coaxial epi-illumination means disposed between the upper polarizer and the liquid crystal cell substrate for projecting a transparent electrode pattern of the liquid crystal cell substrate at a different wavelength from the first co-axial epi-illumination means; An image pickup means disposed above the plate, for acquiring an image of the sealant and the transparent electrode pattern by receiving reflected light from the sealant and the transparent electrode pattern, and an image of the sealant and the transparent electrode pattern. The target area for defect inspection is determined based on

According to a third aspect of the present invention, in the second aspect, the first and second coaxial epi-illumination means are arranged on the same optical axis.
An illumination switching means for switching between the coaxial epi-illumination means, which is arranged on a stage, is provided.

According to a fourth aspect of the present invention, in the third aspect, there is provided a shielding plate access means for inserting and removing a shielding plate between the liquid crystal cell substrate and the lower polarizing plate.

According to a fifth aspect of the present invention, a defect inspection of a liquid crystal cell substrate formed by injecting liquid crystal between transparent substrates and sealing the injected liquid crystal within a display range with a sealant for bonding the transparent substrate is performed. A cell inspection method performed before attaching a polarizing plate to a liquid crystal cell substrate, comprising: an illumination step of projecting a sealing agent from illumination means arranged above the liquid crystal cell substrate; and a reflected light by projection of the illumination means. The method includes a sealant image obtaining step of obtaining an image of the sealant, and a target area determining step of determining a target area for defect inspection of the liquid crystal cell substrate based on the sealant image.

According to a sixth aspect of the present invention, a liquid crystal is injected between transparent substrates provided with a transparent electrode pattern for liquid crystal display, and the injected liquid crystal is sealed within a display range by a sealing agent for bonding the transparent substrates. A cell inspection method for performing a defect inspection on a liquid crystal cell substrate before attaching a polarizing plate to the liquid crystal cell substrate, comprising:
A first illumination step of projecting a sealant by the coaxial epi-illumination means, a sealant image acquiring step of acquiring an image of the sealant from light reflected by the projection of the first coaxial epi-illumination means, and a step above the liquid crystal cell substrate. A second illumination step of projecting a transparent electrode pattern at a wavelength different from that of the first coaxial epi-illumination means by the second co-axial epi-illumination means, and from reflected light by the projection of the second co-axial epi-illumination means. A transparent electrode image obtaining step of obtaining an image of the transparent electrode pattern, and a target area determining step of determining a target area for defect inspection of the liquid crystal cell substrate based on the sealant and the image of the transparent electrode pattern, It is characterized in that the defect inspection is performed only for.

According to a seventh aspect of the present invention, in the method of the fifth or sixth aspect, when an image of the sealant is obtained, an inspection step of inspecting an application state of the sealant is provided.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a liquid crystal cell substrate to be inspected according to a first embodiment of the present invention, and FIG. 2 shows a configuration of a cell inspection device for performing a defect inspection of the liquid crystal cell substrate. .

In this embodiment, a defect inspection of a liquid crystal product (liquid crystal cell substrate) composed of a transparent substrate on which a transparent electrode (ITO film) and the like are formed is performed before attaching a polarizing plate. The liquid crystal cell substrate (the transparent electrode pattern formed
As shown in FIG. 1, a display area 1 for performing liquid crystal display and a sealing agent for bonding the two transparent substrates and sealing the injected liquid crystal are shown in FIG. It has an application section 2 and an edge section 3 outside the sealant application section 2 where no liquid crystal is injected.

This sealant is made of an epoxy resin or the like,
It is applied on a transparent substrate by a method such as screen printing. In the present embodiment, the fact that the sealant applied to the peripheral portion of the liquid crystal is not affected by the rotation of the polarizing plates 6 and 10 and a constant image is obtained by the CCD area sensor 4 or the like is used. Target area for inspection (display area 1
In).

Further, spacers are scattered between the two transparent substrates in order to make the interval between the two transparent substrates uniform. further,
An alignment film for uniformly arranging liquid crystals is provided on each substrate itself or on the inner surface, and the alignment film is rubbed in a predetermined direction in advance. When the polarizing plates 6, 10 are arranged in the same state as the polarizing plates attached to the upper and lower sides of the completed liquid crystal panel with respect to the orientation direction of the liquid crystal molecules by the rubbing process, the reference state is defined as Thus, the polarization axes of the polarizing plates 6 and 10 are directed in orthogonal directions.

In the defect inspection of the liquid crystal cell substrate 8, for example, as is well known, the backlight illumination 11 is turned on from this reference state, and the polarizing plates 6, 10 are rotated about the optical axis by rotating means (not shown). By performing image processing on an image of the liquid crystal cell substrate 8 obtained by an imaging unit described later, display defects or display defects may be detected. Alternatively, a black image, a white image, or the like may be displayed in the display area 1, and an image in the target area obtained by an imaging unit described later may be image-processed to perform a defect inspection such as a dark spot or a bright spot.

The cell inspection apparatus for inspecting the liquid crystal cell substrate shown in FIG. 1 includes a CCD area sensor 4, a lens 5, polarizing plates 6, 10, a coaxial epi-illumination 7, a stage 9, and a backlight 11 as shown in FIG. Prepare.

An image pickup means including a CCD area sensor 4, a lens 5, and the like is disposed above the upper polarizing plate 6, and the lens 5 has an image pickup range fixed to the maximum size of the model to be inspected in the production of various kinds and small quantities. It is installed on the CCD area sensor 4. The imaging unit is configured to input reflected light from the sealant application unit 2 and acquire an image thereof. In the present embodiment, the image thus obtained is subjected to necessary image processing by a control unit (CPU, RAM / ROM, various sensors, input / output unit, etc.) (not shown), and the inside of the sealant application unit 2 is processed. Set as a target area for defect inspection.

The polarizers 6 and 10 are arranged above and below the liquid crystal cell substrate 8 on the optical axis, and the coaxial epi-illumination 7 for detecting the sealant application section 2 by these polarizers 6 and 10 and a liquid crystal cell. It is arranged so as to sandwich a stage 9 for holding the substrate 8.

The coaxial epi-illumination 7 is disposed between the upper polarizer 6 and the liquid crystal cell substrate 8 held on the stage 9,
Illumination means for projecting light onto the liquid crystal cell substrate 8 to detect the sealant application section 2 is configured.

The stage 9 has a hole having a sufficiently large area as compared with a target area portion (including the display area 1) of the liquid crystal cell substrate 8 as a cell to be inspected, and the liquid crystal cell substrate 8 is positioned on the optical axis. The holding means for holding is constituted.

The backlight illumination 11 is constituted by a fluorescent lamp or the like, and projects light from the back of the liquid crystal cell substrate 8 at the time of defect inspection. When the backlight 11 is turned on, a defect inspection of the liquid crystal cell substrate 8 is performed by an optical system including the polarizing plates 6, 10, the CCD area sensor 4, the lens 5, and the like.

Next, the cell inspection method according to this embodiment will be described.

In this embodiment, the backlight illumination 11 is turned off and the coaxial incident illumination 7 is turned on before the defect inspection. By doing so, the transparent display area 1 and the edge portion 3 of the liquid crystal cell substrate 8 become dark images depending on the background darkness, and only the sealant application portion 2 becomes a bright image independent of the background darkness. Becomes Therefore, when the backlight 11 is turned off, the reflected light of the sealant application unit 2 is transmitted through the lens 5 to the C
Upon entering the CD area sensor 4, as shown in FIG. 3, a contrast image between the sealant application section 2 and another transparent portion (including the display area 1 and the edge section 3) is obtained. Therefore, the application state of the sealant can be inspected by setting only bright elements of the image as detection targets, and the target area of the defect inspection can be set in the display area 1.

The method of inspecting the application state of the sealant is to extract the edge portion of the sealant application section 2 by image processing by the control section, perform labeling, and calculate the shortest distance of each element. . As a result, defects such as thinning of the sealant and foreign matters in the sealant application portion are detected.

Further, the method of determining the target area of the defect inspection of the liquid crystal cell substrate 8 is as follows. A bright element is extracted from the bright image of the sealant application section 2 and the area of the sealant application section 2 is limited. Next, the image is inverted and a bright image inside the area of the sealant application section 2 is determined as the target area.

Thereafter, as described above, the backlight illumination 1
Is turned on, an image in the target area is acquired by the imaging means, and image processing such as pattern matching is performed on the image to perform a defect inspection.

The upper surface of the stage 9 (coaxial incident illumination 7)
By applying a dark color to the (projected side) or increasing the distance from the optical system below the stage 9, the contrast between the sealant application section 2 and other transparent portions can be further improved.

According to the present embodiment, in the defect inspection step of the liquid crystal cell substrate 8 before the polarizing plate is attached, which constitutes the liquid crystal product, even if the positioning on the stage 9 is not strict, a necessary target area is In order to perform defect inspections only when the inspection target is changed, it is not necessary to investigate changes in the optical system that require rigorous reproduction even if the inspection target is changed. By automatically extracting the target area, erroneous detection can be suppressed, and the angle between the polarizing plates 6, 10 and the display surface (display area 1) of the liquid crystal cell substrate 8 can be corrected.

Further, according to the present embodiment, by obtaining an image of the sealant application section 2, the state of bonding of the transparent substrate by the sealant can be confirmed, and processing such as pattern matching, which is affected by the size of the operation area, can be performed. Can be shortened. [Second Embodiment] FIG. 4 shows a configuration of coaxial epi-illumination of a cell inspection apparatus according to a second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the coaxial epi-illumination 7 is
It comprises a first coaxial epi-illumination 7b using an ED and a second coaxial epi-illumination 7a using a blue LED. This first
The coaxial epi-illumination 7b is white illumination projected to extract an image of the sealant application unit 2. The second coaxial epi-illumination 7a is a blue illumination projected to extract an image of the above-mentioned transparent electrode (ITO film). The reason why the second coaxial epi-illumination 7a is blue illumination is that the transparent electrode can obtain more contrast on the short wavelength side. The switching between the coaxial epi-illumination lights 7a and 7b is performed manually.

Next, a method of determining a target area for defect inspection of the liquid crystal cell substrate 8 will be described.

First, the backlight illumination 11 is turned off and the first coaxial incident illumination 7b is turned on. By doing so, as described above, the reflected light from the sealant application unit 2 is
And enters the CCD area sensor 4 through the sealant application section 2 and other transparent portions (including the display area 1 and the edge section 3).
Is obtained.

Next, the first coaxial epi-illumination 7b is turned off and the second coaxial epi-illumination 7a is turned on. By doing so, a contrast image of the transparent electrode pattern provided on the transparent substrate constituting the liquid crystal cell substrate 8, other transparent portions (including the display area 1 and the edge portion 3), and the sealant application portion 2 can be obtained. .

Next, arithmetic processing is performed between the obtained images to separate the image of the sealant application section 2 from the image of the transparent electrode pattern. Then, the innermost boundary of the image of the sealant application unit 2 and the outermost boundary of the image of the transparent electrode pattern are obtained, and based on this, the target area of the defect inspection is set to include the transparent electrode. At this time, image processing such as pattern matching is also performed limited to the target area.

According to the present embodiment, the target area of the defect inspection is determined based on the image of the sealant coating unit 2 and the transparent electrode pattern, so that the target area can be more clearly limited and defects outside the target area can be determined. The yield can be improved by ignoring it. [Third Embodiment] FIG. 5 shows a configuration of a cell inspection apparatus according to a third embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The control unit 17 of this embodiment includes image input processing means for acquiring and processing an image from the CCD camera 13 (= imaging means) and coaxial incident light for acquiring an image of the sealant application unit 2. An illumination switching means for switching between the illumination 7 and the backlight illumination 11 for defect inspection.

The hand 19 chucks the edge portion of the liquid crystal cell substrate 8 at the time of acquiring an image of the sealant application section 2 or at the time of defect inspection, and sets it at a predetermined position.

With this configuration, under the control of the control unit 17, the above-described determination of the target area and the cell inspection including the defect inspection of the liquid crystal cell substrate 8 are automatically executed. That is, when the control unit 17 determines that the liquid crystal cell substrate 8 is set at a predetermined position in the optical axis by a detection signal from a not-shown set sensor (for example, an optical reflection type sensor), the backlight switching unit 11 uses the illumination switching unit. Is turned off, the coaxial epi-illumination light 7 is turned on, the image data input from the CCD camera 13 is processed to obtain an image of the sealant application section 2, and a target area for defect inspection is determined based on this image. . Thereafter, the coaxial epi-illumination light 7 is turned off by the illumination switching means, and the backlight illumination 11 is turned on.
Based on the image data input from the CD camera 13, necessary image processing is performed on the target area to execute a defect inspection.

According to the present embodiment, the control unit 17 switches between the coaxial epi-illumination 7 for determining the target area of the defect inspection and the backlight illumination 11 for the defect inspection. It is possible to automatically and efficiently limit and correct the angle between the polarizing plates 6 and 10 and the liquid crystal cell substrate 8. [Fourth Embodiment] FIG. 6 shows a configuration of a cell inspection apparatus according to a fourth embodiment of the present invention. Note that the same components as those of the third embodiment are denoted by the same reference numerals, and description thereof is omitted.

The control unit 24 of this embodiment includes an image input processing means for acquiring and processing an image from the CCD camera 13, a coaxial incident illumination 7 for acquiring an image of the sealant application unit 2, and a defect inspection. And a shielding plate driving unit for controlling the driving of a slider 23 for inserting and removing the shielding plate 22.

The shielding plate 22 is inserted into the optical axis by driving the slider 23 when acquiring an image of the sealant application section 2, and is retracted from the optical axis during defect inspection. The slider 23 includes a spring, a solenoid, and the like, and is configured so that the shielding plate 22 can be freely inserted into and removed from the optical axis.

In the present embodiment, when an image of the sealant application section 2 is acquired, the contrast between the background of the image and the sealant application section 2 is improved by the shielding plate 22 and the 1
Irrespective of the relative angle between the pair of polarizing plates 6 and 10, images of the liquid crystal injection portion (including the display area 1) and the outer peripheral portion where the liquid crystal is not injected (including the edge portion 3) can be constantly obtained. The reliability of the setting of the target area or the defect inspection can be improved. [Fifth Embodiment] FIG. 7 shows a configuration of coaxial epi-illumination of a cell inspection apparatus according to a fifth embodiment of the present invention.
Note that the same components as those of the second and fourth embodiments are denoted by the same reference numerals and description thereof is omitted.

In the present embodiment, the coaxial epi-illumination 7 is
When an image of the sealant application unit 2 is extracted by the illumination switching unit of the control unit 24 while being composed of the first coaxial incident illumination 7b using the ED and the second coaxial incident illumination 7a using the blue LED. Controls to project the first coaxial epi-illumination 7b, and to project the second co-axial epi-illumination 7a when extracting the image of the above-mentioned transparent electrode.

That is, by inserting the shielding plate 22 into the optical axis and turning off the backlight illumination 11 to turn on the first coaxial epi-illumination 7b, as described above, the sealant application section 2 and other transparent parts are turned on. By obtaining a contrast image with the portion and turning off the first coaxial incident-light illumination 7b and turning on the second coaxial incident-light illumination 7a, the transparent electrode pattern of the liquid crystal cell substrate 8 and the other transparent portions are turned on as described above. And a contrast image between the sealant application unit 2 and the sealant application unit 2 are obtained, and the innermost boundary of the image of the sealant application unit 2 and the outermost boundary of the image of the transparent electrode pattern are obtained by arithmetic processing between the images.
Based on this, the target area of the defect inspection is set to include all the transparent electrodes. Thereafter, the shielding plate 22 is retracted from the optical axis, the backlight illumination 11 is turned on to turn off the second coaxial epi-illumination 7a, and the defect inspection is performed only on the target area.

In this embodiment, the control unit 24 switches the backlight illumination 11 and the two types of coaxial incident illuminations 7a and 7b, so that the image of the sealant application unit 2 and the image of the transparent electrode can be changed without changing the optical system. Can be obtained automatically.

[0050]

According to the present invention, the illumination by the illumination means (coaxial epi-illumination) or the first co-axial epi-illumination means (first co-axial epi-illumination) arranged between the upper polarizer and the liquid crystal cell substrate. 2. Obtain an image of the sealant (sealant-applied portion), which is a visible portion that does not depend on the relative angle between the two polarizing plates or the relative angle with the liquid crystal product, and use this image to form a transparent liquid crystal cell substrate. Since the target area of defect inspection is limited, in the defect inspection when producing various kinds of liquid crystal products in small quantities with the same optical system, it is possible to respond to products of various shapes and sizes, and to change the optical system by changing and adjusting during setup change. It is possible to efficiently perform a highly reliable defect inspection in a limited target area without considering a reproducibility error and without being affected by a positional shift of a product. Further, by performing a defect inspection before attaching the polarizing plate, the angle between the polarizing plate and the display surface of the liquid crystal product can be corrected. The size and shape of the target area can prevent the mixing of many types in small-lot production of various types.Furthermore, the target area is limited when the pattern is inspected by turning on the light by setting the optical system and prober. Thus, the processing time can be reduced.

Further, according to the present invention, the image of the transparent electrode of the liquid crystal cell substrate is obtained by projection of the second coaxial epi-illumination means (second co-axial epi-illumination), and the above-mentioned sealing agent and transparent electrode are obtained. By setting a target area for defect inspection based on the above image, the target area can be more strictly limited and a highly reliable defect inspection can be efficiently performed. Therefore,
It is possible to improve the yield without causing defects in a region that does not affect the quality, such as a portion hidden by a frame at the stage of mounting a liquid crystal product, as a defect.

Further, according to the present invention, by switching the first coaxial epi-illumination means and the second co-axial epi-illumination means on the same optical axis by the illumination switching means, a clear image of both is obtained. It is possible to further improve the reliability when determining the target area of the defect inspection.

Further, according to the present invention, a shield plate is inserted between the liquid crystal cell substrate and the lower polarizer by a shield plate access means (shield plate and slider) when acquiring an image of the sealant. By doing so, it is possible to further enhance the contrast between the sealant and the image of the other transparent portion. Therefore, it is possible to further improve the reliability when determining the target area of the defect inspection.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a liquid crystal cell substrate to be inspected according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a cell inspection device according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating an image of a sealant application unit when the backlight is turned off according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of coaxial epi-illumination of a cell inspection device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a cell inspection device according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a cell inspection device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of coaxial epi-illumination of a cell inspection device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display area 2 Sealant application part 3 Edge part 4 CCD area sensor 5 Lens 6, 10 Polarizer 7, 7a, 7b Coaxial epi-illumination 8 Liquid crystal cell substrate 9 Stage 11 Backlight illumination 13 CCD camera 17, 24 Control part 19 Hand 22 shielding plate 23 slider

Claims (7)

[Claims] 1. A liquid crystal cell substrate formed by injecting a liquid crystal between transparent substrates and sealing the injected liquid crystal within a display range with a sealant for bonding the transparent substrate to a polarizing plate. A cell inspection device that performs a state before attaching the liquid crystal cell substrate, a holding means for holding the liquid crystal cell substrate, a polarizing plate disposed above and below the liquid crystal cell substrate, and between the upper polarizing plate and the liquid crystal cell substrate. Illumination means for projecting the liquid crystal cell substrate; andimaging means arranged above the upper polarizing plate for receiving reflected light from the sealant and acquiring an image of the sealant. A cell inspection apparatus, comprising: determining a target area of a defect inspection based on an image of a sealant. 2. A defect in a liquid crystal cell substrate formed by injecting liquid crystal between transparent substrates provided with a transparent electrode pattern for liquid crystal display, and sealing the injected liquid crystal within a display range with a sealant for bonding the transparent substrates. A cell inspection apparatus for performing an inspection before attaching a polarizing plate to the liquid crystal cell substrate, comprising: holding means for holding the liquid crystal cell substrate; and polarizing plates disposed above and below the liquid crystal cell substrate. A first coaxial epi-illumination means for projecting a sealant for the liquid crystal cell substrate, disposed between the upper polarizer and the liquid crystal cell substrate; A second coaxial epi-illumination means for projecting the transparent electrode pattern of the liquid crystal cell substrate at a wavelength different from that of the first co-axial epi-illumination means; and Reflected light And an imaging means for obtaining an image of said sealant and a transparent electrode pattern, cell inspection apparatus characterized by determining a region of interest to defect inspection images of sealant and a transparent electrode pattern groups. 3. An illumination switching means for arranging said first and second coaxial epi-illumination means in two stages on the same optical axis and switching between said two co-axial epi-illumination means.
The cell inspection device as described in the above. 4. The cell inspection apparatus according to claim 3, further comprising a shielding plate entrance / exit means for inserting and removing a shielding plate between the liquid crystal cell substrate and the lower polarizing plate. 5. A defect inspection of a liquid crystal cell substrate formed by injecting a liquid crystal between transparent substrates and sealing the injected liquid crystal within a display range with a sealing agent for bonding the transparent substrate, the polarizing plate being provided on the liquid crystal cell substrate. A cell inspection method performed in a state before attaching the liquid crystal cell substrate, wherein an illumination step of projecting a sealing agent from an illumination unit disposed above the liquid crystal cell substrate, and obtaining an image of the sealing agent from reflected light by the projection of the illumination unit A sealing agent image acquiring step, and a target area determining step of determining a target area for defect inspection of the liquid crystal cell substrate based on the sealing agent image. 6. A defect in a liquid crystal cell substrate formed by injecting liquid crystal between transparent substrates provided with a transparent electrode pattern for liquid crystal display, and sealing the injected liquid crystal within a display range with a sealant for bonding the transparent substrates. A cell inspection method in which inspection is performed before attaching a polarizing plate to the liquid crystal cell substrate, wherein a first coaxial epi-illumination means disposed above the liquid crystal cell substrate projects a sealant. An illuminating step, a sealant image acquiring step of acquiring an image of the sealant from the reflected light by the projection of the first coaxial epi-illumination means, and a second coaxial epi-illumination means arranged above the liquid crystal cell substrate. A second illumination step of projecting a transparent electrode pattern at a wavelength different from that of the first coaxial epi-illumination means; and a transparent step of acquiring an image of the transparent electrode pattern from light reflected by the projection of the second co-axial epi-illumination means. An electrode image obtaining step; and a target area determining step of determining a target area for defect inspection of the liquid crystal cell substrate based on the image of the sealant and the transparent electrode pattern, wherein the defect inspection is performed only on the target area. Cell inspection method. 7. The cell inspection method according to claim 5, further comprising an application state inspection step of inspecting an application state of the sealant when an image of the sealant is obtained.