JP2001242084A - Illumination device and granular object detection device - Google Patents

Abstract

(57) [Problem] To increase the contrast between scattered light from a spacer and reflected light from a wiring pattern,
Provided are an illumination device and a granular object detection device which facilitate separation of a spacer and a background by binarization. SOLUTION: A light guide 1 as light supply means,
A mirror 2 held so as to reflect light from the light guide 1. This illuminating device is used to detect a spacer 7 as a granular body, with respect to a desired detection position.
The light 5 is irradiated in at least two directions that are not substantially perpendicular to any linear portion of the wiring pattern when viewed from above, and in an irradiation direction such that an angle formed with the upper surface of the glass substrate 6 is 3 ° or less. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for counting spacers used for forming a gap between glass substrates such as a liquid crystal panel having a thin film transistor (TFT) as a switching element for driving a liquid crystal. The present invention relates to a particulate matter detection device for performing a cohesion test and a foreign material test for detecting a foreign material on a glass substrate, and a lighting device used for the same.

[0002]

2. Description of the Related Art (Manufacturing process of liquid crystal panel) A liquid crystal panel has electrodes for driving liquid crystal, and is formed between a pair of glass substrates arranged in parallel at a predetermined interval and between the pair of glass substrates. Liquid crystal layer. This liquid crystal panel is manufactured by the following method.

[0003] Among the pair of glass substrates, a thermosetting sealing agent is applied to one of the glass substrates, and spacers for uniforming the distance between the substrates are sprayed on the other glass substrate. As the spacer here, plastic beads having a uniform sphere diameter are usually used. Thereafter, the pair of glass substrates is aligned and temporarily fixed.

The glass substrate is pressed so that the distance between the substrates is equal to the diameter of the spacer. Heating cures the sealant and performs lamination. The bonded substrate is cut into a desired liquid crystal panel size. In a vacuum chamber, liquid crystal is injected into a gap between glass substrates. After the liquid crystal injection, an injection-curable sealing agent is applied to the injection port and irradiated with ultraviolet light to seal the injection hole.

According to the above method, a liquid crystal panel in which a gap between a pair of glass substrates is filled with liquid crystal can be manufactured.

(Spacer) In the above-described manufacturing process of the liquid crystal panel, the number and distribution of the spacers that are arranged to uniformly form the gap between the glass substrates of the liquid crystal panel are important. If the number of the spacers is too small, the gap between the glass substrates becomes narrow, a predetermined gap cannot be formed, and the display quality deteriorates. Also, if there are too many spacers,
So-called light loss around the spacer increases. `` Light loss '' means that the liquid crystal around the spacer causes disorder in alignment, or if the spacer is transparent, the spacer itself transmits light, so that it tries to black display by blocking the light. In this case, the light is transmitted only at that point, and the black display is not correctly performed. Occurrence of such glare causes a decrease in contrast,
The display quality deteriorates.

Therefore, it is necessary to measure the number and distribution of the spacers after dispersing the spacers and monitor the dispersal state of the spacers. The following method is used as a method for counting the number of spacers. Illumination light is applied to the spacer by reflection illumination using a ring light 41 as shown in FIG. 6 to generate scattered light from the spacer. The scattered light from the spacer is captured using a CCD camera. By binarizing the captured image, the spacer and the background are separated, and the number of spacers is counted.

The glass substrate on which the spacers are scattered is T
In the case of a glass substrate on which an FT is formed, a wiring pattern such as a gate line and a source line is formed of a metal film having a high reflectance, such as Ta or Al. When the unevenness of the wiring pattern is large, the edge of the wiring pattern also generates reflected light by illumination with a ring light. Therefore, it is difficult to separate the wiring pattern formed on the glass substrate and the spacer by binarization.

On the other hand, in Japanese Patent Application Laid-Open No. Hei 8-148525, in order to reduce the reflected light from the wiring pattern formed on the glass substrate, in the structure shown in FIG. A technique has been proposed in which a portion irradiated at right angles to the wiring pattern of the source line is shielded from light. As a result, the reflected light from the wiring pattern can be reduced, and the distance between the spacer and the background can be reduced.
Separation by quantification becomes easy.

[0010]

According to the technique proposed in the publication, when counting the spacers, the counting is performed at an arbitrary measuring point while moving the substrate to be measured. In order to realize this, in the lighting device proposed in the publication, the ring light 41 is installed so as to float only by a clearance that does not make contact with the glass substrate 6 even when the glass substrate 6 is moved.

At this time, the ring light 41 shown in FIG.
Is disposed at a position slightly above the bottom surface of the ring light 41. If the portion below the optical fiber projector 42 is referred to as a plate 43, it is desirable to make the plate 43 as thin as possible in order to make the light from the optical fiber projector 42 as horizontal as possible. If the thickness is too thin, the strength of the ring light 41 cannot be maintained. But,
If the plate 43 is made thick, light from the optical fiber light emitting port 42 enters the measurement location from obliquely above.

Therefore, when the unevenness of the wiring pattern at the measurement location is large, the irradiation light from the non-light-shielded portion of the ring light is directed to the upper CCD camera at a location where the illumination light is applied substantially perpendicularly to the wiring pattern portion. A large amount of reflected light in the direction is generated.

Alternatively, even if the plate 43 is slightly thicker,
By increasing the diameter of the ring light 41, it is possible to make the incidence of light on the measurement location nearly horizontal,
In that case, the distance from the optical fiber light emitting port 42 to the measurement location becomes longer, and the illuminance decreases.

After all, according to this illuminating device, the reflected light from the wiring pattern of the gate line and the source line is reduced, but the illuminating light from the unshielded portion of the ring light is reduced.
In some cases, reflected light is generated at a portion irradiated perpendicularly to the wiring pattern, so that there is a problem that it is difficult to separate the spacer and the background by binarization.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and reduces reflected light from a wiring pattern formed on a glass substrate of a liquid crystal panel, and reduces scattered light from a spacer and the wiring pattern. It is an object of the present invention to provide an illumination device and a granular object detection device that facilitate separation of a spacer and a background by binarization by increasing the contrast with reflected light.

[0016]

In order to achieve the above object, in an illumination device according to the present invention, a lighting device is provided at a desired detection position on an upper surface of a substrate having a matrix linear pattern provided orthogonally to the upper surface. In order to detect the granular material to be detected, at least two directions that are not substantially perpendicular to any linear portion of the linear pattern when viewed from above with respect to the desired detection position, and form the upper surface of the substrate. Light is irradiated in an irradiation direction such that the angle is 3 ° or less. By adopting this configuration, the linear portion of each component of the linear pattern is not irradiated with light substantially vertically when viewed from above, and the angle formed with the upper surface of the substrate is good even in experiments. Since the obtained result is 3 ° or less, reflected light upward from the edge of each of these components can be reduced.

In the above invention, preferably, there is provided a light supply means, and a mirror held so as to reflect the light from the light supply means in the irradiation direction. By adopting this configuration, the light can be reflected at the lower end of the mirror, so that the light can be reflected at a position very close to the substrate. As a result, the angle formed with the upper surface of the substrate is 3 ° or less. Irradiation of light with sufficient illuminance in the irradiation direction can be performed reliably and easily.

Preferably, in the above invention, a holder having the lower surface for holding the light supply means and the mirror is provided, and the lower surface is provided with a concave portion so as not to hinder the light traveling in the irradiation direction. .

By adopting the above configuration, the positional relationship between the light supply means and the mirror is more reliably fixed due to the presence of the holder, and the handling of the illumination device is facilitated. Also,
Since there is a concave portion on the lower surface of the holder, even if the light reflected from the mirror is diffused or the traveling direction is shifted, if it is within a certain range, it is not hindered by the lower surface of the holder,
It is possible to reach the measurement point and irradiate with sufficient illuminance. Further, by making the depth of the concave portion not deeper than a certain value, it is possible to have a role of blocking light traveling in the irradiation direction such that the angle formed between the concave portion and the upper surface of the substrate is larger than a desired angle.

In the above invention, preferably, a lens is provided which condenses the light emitted from the light supply means and guides the light to the mirror. By employing this configuration, the light supplied from the light supply means can be efficiently reflected by the mirror. Further, since the collected light is reflected and travels to the measurement location, the illuminance at the measurement location can be increased.

In the granular object detecting apparatus according to the present invention, an illuminating means including the above-mentioned illuminating device, a light detecting means for detecting a reflected light from the desired measurement site irradiated by the illuminating means, and a light detecting means Extracting means for separating and extracting information derived from the granular material from the result detected by the means.

By adopting the above configuration, of the irradiated light, the component reflected by the linear pattern and traveling toward the light detecting means decreases, while the light scattered by the granular material travels toward the light detecting means. In the image detected by the light detecting means, the contrast between the image of the granular material and the image of the background is large, and it is easy to binarize and separate the image due to the granular material from the image due to the background. Become. Further, since the granular material detection device includes the extracting means, it is possible to easily count and grasp the distribution of the granular material with high accuracy.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) (Configuration) FIG. 1 shows a lighting device according to the present embodiment. The illumination device includes a light guide 1 that is a light supply unit that irradiates light from a light source (not shown), a mirror 2 that reflects irradiation light from the light guide 1 to a glass substrate 6, A holder 3 for holding the mirror 2 is provided. When the glass substrate 6 to be measured is placed on a horizontal surface and the illumination device is installed above the glass substrate 6 to perform the measurement, the light guide 1 emits light from vertically upward to vertically downward. The mirror 2 has an angle of 46 with respect to the horizontal plane of the reflection surface.
° and is fixed to the holder 3. The angle formed by the reflection surface of the mirror 2 with the horizontal plane was 46 ° here,
This is because, as shown in FIG. 2, when the mirror 2 reflects the light emitted from the light guide 1 vertically above, the angle between the reflected light and the horizontal plane is 2 °. This is because the irradiation direction is directed to the measurement location.
When the holder 3 has a structure having no lower surface, there is no possibility that the lower surface of the holder 3 hinders the progress of light.
In order to maintain the strength, it is conceivable that the structure has a lower surface, in which case it is preferable that a concave portion is provided on the lower surface so as not to hinder light traveling toward the measurement location . In the structure of FIG. 1, a groove 4 is provided as such a concave portion. By making the depth of the groove 4 not deeper than a certain value, it is possible to have a role of blocking light traveling in the irradiation direction such that the angle formed between the groove 4 and the upper surface of the substrate is larger than a desired angle.

FIG. 3 shows a state in which the measurement of the glass substrate 6 is performed by the illumination device as viewed from above.
The glass substrate 6 has a wiring pattern in which the gate line 11 and the source line 12 are orthogonal to each other as a matrix linear pattern provided on the upper surface thereof at right angles. Has a TFT element 13. The following description will be made with the center of the transparent electrode 14 in each section as a measurement point.

Referring to FIG. 3, focusing on the direction of light irradiation on the measurement point, the light is irradiated as light 5 from four orthogonal directions which are rotated by about 45 ° from the direction of the linear pattern. As described above, the light guide 1, the mirror 2 and the groove 4 are arranged.

(Operation / Effect) The light emitted from the light guide 1 is reflected by the mirror 2, passes through the groove 4, and travels as a light 5 toward the measurement location. The light 5 is irradiated in an irradiation direction such that the angle formed with the upper surface (horizontal plane) of the glass substrate 6 is 2 ° from the above four orthogonal directions. Light 5 is applied to spacer 7
Scatters on hit. If some kind of light detecting means is installed above this lighting device, scattered light from the spacer 7 can be detected and used as information for inspection.

On the other hand, since the angle between the light 5 and the upper surface of the glass substrate 6 is as small as 2 °, the reflected light caused by the wiring pattern formed on the glass substrate 6 can be reduced in a component reflected upward. The scattered light caused by the spacer 7 can be dominant in the light detected when the light detecting means is disposed above.

The light 5 from the four directions irradiates the straight line portions of the gate line 11 and the source line 12 from the direction rotated by about 45 ° when viewed from above. Light does not irradiate straight lines such as the line 12 and the TFT element 13 substantially perpendicularly, and the upward component of light reflected from the edges of these wiring patterns can be reduced.

(Embodiment 2) (Structure) FIG. 4 shows a lighting device according to the present embodiment. Basically, those described in the first embodiment (FIG. 1,
3), but includes a condenser lens 26 as a lens for condensing light emitted from a light guide 21 as a light supply unit and guiding the light to a mirror 22. Condensing lens 2
Reference numeral 6 is held by the condenser lens holder 27 together with the light guide 21.

(Operation and Effect) As described above, the condenser lens 26
Is provided, the light supplied from the light guide 21 can be efficiently reflected by the mirror 22. In addition, since the collected light is reflected and travels to the measurement location as light 25, the illuminance at the measurement location can be increased.

In each of the above embodiments, the angle between the reflecting surface of the mirror 2 and the horizontal plane is 46 °, and the angle between the reflected light and the horizontal plane is 2 °. May be a value other than these. The experiment was conducted by changing the angle several times. When the angle between the reflected light and the horizontal plane was greater than 3 °, the reflection from the wiring pattern detected when the light detection means was placed above The light increased to such an extent that it was difficult to separate the spacer and the wiring pattern due to the binarization of the image. However, if the angle was set to 3 ° or less, the reflected light from the wiring pattern could be significantly reduced. Separation became easy. Therefore, it is desirable that the angle between the reflected light and the horizontal plane is 3 ° or less.

This is because the spacer is mounted so as to protrude greatly above the substrate surface, whereas the wiring pattern is lower than the spacer surface compared to the spacer, so that the wiring pattern is formed at an angle close to a horizontal angle or more. When light is applied, the light impinges on the spacers and is scattered, but the light impinging on the wiring pattern is significantly reduced.

The technique disclosed in Japanese Patent Application Laid-Open No. Hei 8-148,025 also discloses that the light is emitted "almost in the horizontal direction". The angle between the irradiation direction and the horizontal plane must be less than 3 ° because of the restriction that it must be provided near the substrate and that the strength of the ring light itself must be maintained by the plate below the optical fiber light outlet. It was a large value. That is, "almost horizontally"
Substantially only a relatively horizontal illumination direction selected within an angle of greater than 3 °. On the other hand, according to the present invention, when it is 3 ° or less,
The present invention has been found to be particularly preferable, and on the other hand, has provided an illuminating device capable of actually irradiating in a direction of 3 ° or less by eliminating the above-mentioned restriction.

In each of the above embodiments, when viewed from above, the light is emitted from four orthogonal directions which are rotated by about 45 ° from the direction of the linear pattern. This rotation angle is not limited to about 45 °,
As long as it is a direction that is not substantially perpendicular to any linear portion of the linear pattern, the angle with respect to the linear pattern when viewed from above may be irradiation from another angle. In addition, the irradiation from four orthogonal directions is particularly preferable in order to increase the illuminance of the measurement location, adjust the balance of the scattering direction in the spacer, and increase the scattered light from the spacer, but it is not essential, but at least Irradiation from two directions may be used.

(Embodiment 3) (Structure) FIG. 5 shows a granular object detecting apparatus according to the present embodiment. This granular material detection device is for detecting a granular material present at a desired detection position on the upper surface of a substrate, and includes the illumination device 32 described in Embodiment 1 or 2 as illumination means. Furthermore, this granular object detection device
A CCD camera 34 is provided as light detection means for detecting reflected light from a desired measurement location irradiated by the illumination device 32. Further, the granular object detecting device is provided with a CCD camera 34.
An image processing device 35 is provided as an extracting unit for separating and extracting information derived from the granular material from the result detected in step (1).

The light guide 31 of the lighting device 32 receives light from a light source device 33. Light guide 31
However, even if there are a plurality of nodes,
It can be covered by the light source device 33. Light source device 3
For 3, a halogen lamp can be used, for example, but not limited thereto, and any lamp that emits similar light may be used. The illuminating device 32 is held floating above the glass substrate 6 by a certain clearance so that the illuminating device 32 does not come into contact with the glass substrate 6 on which the spacers 7 are scattered.

(Operation / Effect) The detection of the spacer is performed in the following procedure. The glass substrate 6 is moved so that a desired measurement position of the glass substrate 6 on which the spacers 7 are scattered is directly below the CCD camera 34. Lighting device 32
Is applied to the measurement location.

The irradiation light from the illumination device 32 makes an angle of 2 ° with the upper surface (horizontal plane) of the glass substrate 6 from the four orthogonal directions as described in the first embodiment with respect to the wiring pattern.
Irradiation is performed in such an irradiation direction as follows. As a result, as described in Embodiment 1, the irradiated light is applied to the spacer 7.
However, components reflected toward the upper CCD camera 34 by reflected light from edges of a wiring pattern or the like can be reduced. That is, CC
As light detected by the D camera 34, scattered light from the spacer 7 becomes dominant. Therefore, the CCD camera 3
When the image captured in step 4 is processed by the image processing device 35, the contrast between the image of the spacer 7 and the background image is large, and the image is binarized and is caused by the spacer 7 and the background. It is easy to separate them. As a result, the detection accuracy of the spacer is increased, and the counting and distribution of the spacer can be performed with high accuracy.

In each of the above embodiments, the spacer is detected, but the aggregation of the spacer may be detected, or a foreign substance such as dust or dust on the glass substrate may be detected. That is, it can be used for detection of a granular material other than the spacer.

The above-described embodiment disclosed herein is illustrative in all aspects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes any modifications within the scope and meaning equivalent to the terms of the claims.

[0041]

According to the present invention, since the light is reflected by the mirror to irradiate the light in the irradiation direction in which the angle formed with the upper surface of the substrate is 3 ° or less, the light is reflected upward from the linear pattern. The reflected light can be reduced. Therefore, in the image detected by the light detecting means provided above, the contrast between the image of the granular material and the image of the background increases. Therefore,
It is easy to binarize and separate the one caused by the granular material from the one caused by the background.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lighting device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an optical path according to the first embodiment based on the present invention.

FIG. 3 is a plan view of the lighting device according to the first embodiment based on the present invention.

FIG. 4 is a sectional view of a lighting device according to a second embodiment of the present invention.

FIG. 5 is a side view of a granular object detection device according to a third embodiment of the present invention.

FIG. 6 is a perspective view of a lighting device according to the related art.

[Explanation of symbols]

1,21,31 light guide, 2,22 mirror,
3,23 holder, 4,24 groove, 5,25 light, 6
Glass substrate, 7 spacer, 11 gate line, 12
Source line, 13 TFT element, 14 transparent electrode,
26 condenser lens, 27 condenser lens holder, 32 illumination device, 33 light source device, 34 CCD camera, 35
Image processing device, 41 ring light, 42 optical fiber light emitting port, 43 plate.

Claims (5)

[Claims] 1. A method for detecting a granular material present at a desired detection position on a top surface of a substrate having a matrix-shaped linear pattern provided orthogonally to the top surface, with respect to the desired detection position. An illumination device that irradiates light in at least two directions that are not substantially perpendicular to any straight line portion of the linear pattern as viewed from above, and in an irradiation direction such that an angle formed with the upper surface of the substrate is 3 ° or less. . 2. The lighting device according to claim 1, further comprising a light supply unit, and a mirror held so as to reflect light from the light supply unit in the irradiation direction. 3. A holder for holding the light supply means and the mirror and having a lower surface, wherein the lower surface is provided with a concave portion so as not to hinder light traveling in the irradiation direction. The lighting device according to claim 1. 4. The lighting device according to claim 2, further comprising a lens that collects light emitted from the light supply unit and guides the light to the mirror. 5. An illuminating device including the illuminating device according to claim 1, a light detecting device for detecting reflected light from the desired measurement location irradiated by the illuminating device, and a detecting device for detecting the reflected light. An extraction unit for separating and extracting information resulting from the granular material based on the result obtained.