JP2000097864A - Floodlight device for visual inspection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To illuminate uniformly the whole relative to even a large-sized test member, by executing partial illumination of a test member from an illumination light source through a reflecting mirror, and by changing the illumination direction of an illumination luminous flux corresponding to relative positions between the illumination light source and the reflecting mirror. SOLUTION: A glass substrate, namely, a test member, is loaded on a holder 2, and the holder 2 is raised corresponding to the height of observer's eyes, and inclined at a prescribed angle. An illumination light source 4 is moved to an illumination position A of a guide 5 in this state, and thereby the optical axis of the illumination light source 4 is inclined at an angel θ relative to the center line O, and the light from the illumination light source 4 is reflected on a reflecting mirror 6, and emitted as a parallel luminous flux from a Fresnel lens 71. Besides, the light is emitted as an illumination luminous flux 8 from a Fresnel lens 72, and irradiated on the face of the glass substrate, to thereby enable macro-inspection of a flaw or a dirt on the substrate face containing the left half. Thereafter, the illumination light source 4 is changed over to an illumination position A' along the guide 5, to thereby enable macro-observation for inspecting a flaw or a dirt, even in case of a large-sized glass substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light projector for visual inspection used for visual inspection of large liquid crystal glass substrates and the like.

[0002]

2. Description of the Related Art Conventionally, in order to stably maintain the quality of a glass substrate of a liquid crystal display, an inspection of the appearance of unevenness in the thickness of a resist or the like on a substrate, a pinhole on an ITO film, etc., and a printing on the substrate have been carried out. It is very important to inspect the appearance of patterns for irregularities and irregularities, and dust and scratches attached to the substrate surface.

Conventionally, a light projector for visual inspection is used for such visual inspection. Among such light projectors for visual inspection, unevenness in film thickness of a resist or the like on a substrate and ITO film. As shown in FIG. 6, an elliptical rotating mirror 102 is arranged on the back of the light source 101 as a material suitable for visual inspection of the upper pinhole and the like, and the illumination light from the light source 101 is reflected by the elliptical rotating mirror 102 to absorb heat rays. Collected at the gate 104 via the filter 103,
05, the light is incident on the Fresnel lens 106 for condensing, and is regulated to a parallel light flux. The glass substrate 107 as a member to be inspected is arranged at a predetermined angle in the parallel light flux regulated by the Fresnel lens 106 for condensing. The surface of the glass substrate 107 is evenly illuminated, and minute scattering light generated from the surface of the glass substrate 107 is visually observed by an observer 108. Defective part 109 such as upper pinhole
Is detected.

FIG. 7 shows the same parts as those shown in FIG. 6 with the same reference numerals as those shown in FIG. 6, which are suitable for inspecting the appearance of the pattern printed on the substrate, such as disturbance or unevenness, or dust or scratches attached to the substrate surface. As shown in FIG.
The light projecting Fresnel lens 110 is further arranged in the parallel light flux regulated by
A glass substrate 107 as a member to be inspected is arranged at a predetermined angle in the optical path before the convergence position A of the light flux due to 0, and the surface of the glass substrate 107 is evenly illuminated and reflected from the glass substrate 107. By observing the minute scattered light generated from the surface of the glass substrate 107 from the vicinity of the light convergence position S with the visual observation of the observer 108, the pattern printed on the substrate is disturbed or uneven, or adheres to the substrate surface. There is one that detects a defective portion 111 such as dust or scratches.

[0005] Recently, liquid crystal displays have been increasing in size, and accordingly, the glass substrates used for them have also been increasing in size. However, in any of the above-described configurations, when the size of the glass substrate is increased, the condensing Fresnel lens 106 or the light projecting Fresnel lens 1 having a size equal to or larger than the size of the glass substrate at this time is used.
10 are required, so that these light-collecting Fresnel lenses 1
06 and the Fresnel lens 110 for light projection tend to be larger and larger. With the current technology, making the lens diameter larger than necessary is difficult to manufacture in order to keep the lens performance constant, and this also makes it difficult to illuminate the glass substrate 107 evenly. There is a problem that the reliability of the visual inspection is reduced. In addition, if a large-sized Fresnel lens 106 for condensing or a Fresnel lens 110 for projecting is used, the focal length becomes large. Therefore, in the case of the vertical type as shown in the figure, the dimension in the height direction becomes extremely large, and There is a problem that the size cannot be avoided.

Therefore, recently, as one corresponding to the enlargement of the glass substrate, one disclosed in Japanese Patent Application Laid-Open No. 9-273996 is considered. FIG. 8 shows a schematic configuration of such a light projecting device for visual inspection.
1 and 125, the illumination light from one light source 121 is reflected by an elliptical rotating mirror 122, and the heat ray absorbing filter 12
The light from the gate 124 is passed through the filter 130 to one of the divided Fresnel lenses 1321 of the Fresnel lens 132 through the filter 124, and similarly, the other light source 1
The illumination light from the mirror 25 is reflected by the elliptical rotating mirror 126, and is transmitted from the gate 129 via the heat ray absorbing filter 128 to the condensing Fresnel lens 13 through the filter 131.
Irradiation is performed on the other divided light-collecting Fresnel lens 1322. In addition, these divided light-collecting Fresnel lenses 132
1 and 1322, the parallel light flux is further divided into light-emitting Fresnel lenses 13 of light-emitting Fresnel lens 133.
31 and 1332, and the glass substrate 1
Irradiation is performed on 35 surfaces. In this case, the light source 12
1, 125, the respective illumination optical axes 121a, 125a
Fresnel lenses 1321 and 1322
The optical axes 1321a and 1322a are displaced by a predetermined angle, and the light source image positions of the light sources 121 and 125 are made to coincide with the convergence position A of the luminous flux by the divided light projecting Fresnel lenses 1331 and 1332. By observing the minute scattered light caused by the defect 136 on the glass substrate 135 from the vicinity of the converging position S of the reflected light from the glass substrate 135 by the observer 137, the pattern printed on the substrate is obtained. Defective portions 136 such as turbulence and unevenness, and dust and scratches attached to the substrate surface are detected.

[0007]

However, the above-mentioned structure has a light source, an elliptical rotating mirror,
Since it is necessary to arrange a plurality of sets of illumination optical systems including a heat ray absorption filter and the like, the number of components is increased, and the apparatus is increased in size and the price is increased.

The present invention has been made in view of the above circumstances, and can illuminate the entirety of a large member to be inspected evenly, and has a simple structure and can be manufactured at low cost. It is an object to provide an optical device.

[0009]

According to the first aspect of the present invention,
It comprises an illumination light source for partially illuminating a member to be inspected via a reflection mirror, and irradiation variable means for changing an irradiation direction of an illumination light beam according to a relative positional relationship between the illumination light source and the reflection mirror.

According to a second aspect of the present invention, in the first aspect of the invention, the irradiation variable means is provided so that the illumination light source is linearly movable, and the partial illumination can be set at a plurality of positions with respect to the member to be inspected. It is characterized by doing.

According to a third aspect of the present invention, in the first aspect of the present invention, the irradiation variable means is provided so that the illumination light source can be moved linearly, and the movement range of the illumination light source is changed according to the size of the member to be inspected. It is characterized by being adjustable.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the illumination variable means is provided so as to be capable of swinging the reflection mirror, and adjusts the swing angle of the reflection mirror according to the size of the member to be inspected. It is characterized by being adjustable.

As a result, according to the present invention, by changing the irradiation direction of the partial illumination, even the small light source can illuminate the entire surface of the large non-inspection member uniformly, and the illumination light source and the optical means can be used. Since only one set of illumination optical system is provided, the number of parts can be reduced. Further, according to the present invention, since the illumination range of the partial range can be adjusted according to the size of the inspected member, the entire surface of each inspected member can be evenly illuminated.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a schematic configuration of an appearance inspection light emitting device to which the present invention is applied. In the figure, 1
Is an apparatus main body. Inside the apparatus main body 1, a holder 2 is disposed as a member to be inspected holding means. This holder 2
Holds a large glass substrate 3 used for a flat display such as an LCD as a member to be inspected.
The front end of the apparatus main body 1 is rotatably supported, and can be turned upside down within a predetermined angle around this support.

Above the apparatus main body 1, an illumination light source 4 composed of, for example, a metal halide lamp is provided. The illumination light source 4 is reciprocally movable by a driving means (not shown) along a guide 5 arranged along the width direction of the apparatus main body 1 as shown in FIG. Illumination position A indicated by a solid line and illumination position A ′ indicated by a broken line
, Respectively. The illumination light source 4 is moved along the guide 5 so that the illumination position A
Is located at an angle θ with respect to the center line O, and when at the illumination position A ′, it is located at an angle θ ′ with respect to the center line O.

The reflecting mirror 6 is opposed to the illumination light source 4.
In the illustrated example, they are arranged at an angle of 45 ° so that the light from the illumination light source 4 is reflected and given to the Fresnel lens 7. The Fresnel lens 7 includes a first Fresnel lens 71 and a second Fresnel lens 72. The first Fresnel lens 71 emits a parallel light beam from illumination light incident from the reflection mirror 6, and outputs a second light beam. The Fresnel lens 72 receives predetermined points B and B ′ as shown in FIGS. 3A and 3B from a parallel light beam incident from the first Fresnel lens 71 according to the illumination positions A and A ′ of the illumination light source 4. Illumination flux 8, 8 'converging at
Is irradiated onto the glass substrate 3. That is, the second
When the illumination light source 4 is located at the illumination position A, the Fresnel lens 72 emits the illumination light beam 8 that illuminates the surface of the glass substrate 3 indicated by oblique lines in FIG.
In this case, the illumination light beam 8 'for illuminating the surface of the glass substrate 3 indicated by oblique lines in FIG. 3B is emitted.

Next, the operation of the embodiment configured as described above will be described. First, a glass substrate 3, which is a member to be inspected, is placed and held on the holder 2, and as shown in FIG. 1, the holder 2 is raised and inclined at a predetermined angle corresponding to the height of the line of sight of the observer. In this state, when the illumination light source 4 is moved to the illumination position A at one end of the guide 5 as shown in FIG.
The optical axis of the illumination light source 4 is inclined at an angle θ with respect to the center line O.

Then, the light from the illumination light source 4 is reflected by the reflection mirror 6, emitted as a parallel light beam from the first Fresnel lens 71, and further emitted from the second Fresnel lens 72.
The light is emitted as an illumination light flux 8 converging at point B, and irradiates the surface of the glass substrate 3 on the holder 2 indicated by oblique lines in FIG. As a result, a macro inspection is visually performed on the substrate surface including the left half irradiated with the illumination light beam 8 for scratches, dirt, and the like.

Next, when the illumination light source 4 is moved along the guide 5 to the illumination position A 'at the other end of the guide 5 by a driving means (not shown), the optical axis of the illumination light source 4 becomes an angle with respect to the center line O. θ 'tilt.

Then, the light from the illumination light source 4 is reflected by the reflection mirror 6, emitted as a parallel light beam from the first Fresnel lens 71, and further emitted from the second Fresnel lens 72.
The light is emitted as an illumination light beam 8 ′ that converges at the point B, and irradiates the surface of the glass substrate 3 on the holder 2 shown by oblique lines in FIG. As a result, a macro inspection is visually performed on the substrate surface including the right half irradiated with the illumination light beam 8 'for scratches and dirt.

Accordingly, by moving the illumination light source 4 along the guide 5, it becomes possible to scan the illumination light source (partial illumination). Further, by switching the illumination light source 4 to the illumination positions A and A ', even if the glass substrate 3 becomes large, it is possible to irradiate the entire surface of the glass substrate evenly, and a macro for inspecting scratches, dirt, etc. Observations can be made. In addition, since only one set of illumination optical system including the illumination light source 4, the reflection mirror 6, the first Fresnel lens 71, and the second Fresnel lens 72 is provided, the number of parts is reduced, and the apparatus can be downsized. It can be cheaper in price. Furthermore, by using partial illumination, the irradiation area on the substrate surface can be reduced, so that an illumination light source with a small power can be used to obtain the same level of brightness.

In the above-described embodiment, the entire surface of the glass substrate 3 can be illuminated by moving the illumination position of the illumination light source 4. However, the reflection angle of the reflection mirror 6 is adjusted, and Even if the entire surface of the glass substrate 3 can be illuminated by the illumination light beam reflected by 6, the same effect as described above can be obtained. (Second Embodiment) FIGS. 4A and 4B show a schematic configuration of a second embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals. .

In this case, the illumination light source 4 includes a plurality of illumination positions P along the width direction of the apparatus main body 1 as shown in FIG.
Positioning is possible at 1, P2 and P3. The glass substrate 3 is configured such that a plurality of observation sections C1, C2, and C3 are set as shown in FIG. 4B by inputting external shape data corresponding to the size to a control device (not shown). Has become.

In such a configuration, when the observer inputs the outer shape data to the control device according to the size of the glass substrate 3, the observer inputs the outer shape data according to the outer shape data at this time, for example, as shown in FIG.
As shown in (b), a plurality of observation sections C1, C2, C3 are set.

From this state, when the illumination light source 4 is turned on,
The illumination light source 4 is moved to the illumination position P1 along the width direction of the apparatus main body 1 by a control signal from the control device, and illuminates an area including the observation section C1 on the glass substrate 3 with the illumination light beam 81 at this time. Thereby, macro observation in the observation section C1 on the glass substrate 3 can be performed. Next, when the macro observation in the observation section C1 ends, the illumination light source 4 is moved to the illumination light illumination position P2, and the illumination light flux 82
As a result, the observation section C2 on the glass substrate 3 is irradiated, and this time, macro observation can be performed in the observation section C2. Further, when the macro observation in the observation section C2 is completed, the illumination light source 4 is moved to the illumination light illumination position P3, and irradiates the observation section C3 on the glass substrate 3 with the illumination light beam 83, and the observation section C3 Macro observation can be performed.

Thus, the illumination light source 4 is moved to the illumination position P
The glass substrate 3 is sequentially moved to 1, P2 and P3.
Since the divided observation sections C1, C2, and C3 can be sequentially irradiated, macro observation can be performed on the entire surface of the glass substrate 3.

Therefore, in this way, the glass substrate 3
However, even if the size of the glass substrate 3 is further increased, the entire surface of the glass substrate 3 can be evenly illuminated with a small illumination light source. In addition, by dividing the same substrate into a plurality of observation sections, visual observation can be concentrated on each observation section, so that the observation accuracy can be improved, and the movement of the observer's eyes is reduced, and fatigue is suppressed. Can be.

In the above-described embodiment, an example has been described in which the glass substrate 3 is divided into three observation sections C1, C2, and C3. However, the glass substrate 3 can be set to three or more sections. In this case, the illumination position by the illumination light source 4 is also four or more. (Third Embodiment) FIGS. 5A and 5B show a schematic configuration of a third embodiment of the present invention, and the same parts as those in FIG. 1 are denoted by the same reference numerals. .

In this case, as shown in FIGS. 5A and 5B, the illumination light source 4 inputs external shape data corresponding to the size of the glass substrate 3 to a control device (not shown).
Can be switched between L1 and L2 in the width direction.

In such a configuration, the observer inputs the outer shape data to the control device according to the size of the glass substrate 3, but now, as shown in FIG. If it is larger, the moving distance of the illumination light source 4 is set to L1 according to the outer shape data at this time.

In this state, when the illumination light source 4 is turned on,
The illumination light source 4 moves by the movement distance L1 according to a control signal from the control device, and by moving the illumination light source 4 within this movement range L1, the entire surface of the glass substrate 3 having a large external dimension can be irradiated. .

When the external dimensions of the glass substrate 3 are small as shown in FIG. 5B, the moving distance L2 of the illumination light source 4 is set according to the external data at this time. When the illumination light source 4 is turned on from this state, the illumination light source 4 moves by a movement distance L2 according to a control signal from the control device, and by moving the illumination light source 4 within this movement range L2, the external dimensions are obtained. Can irradiate the entire surface of the glass substrate 3 having a small size.

Thus, even when the sizes of the glass substrates 3 are different, it is possible to irradiate the entire surface of each glass substrate 3 evenly, and to set an optimum illumination scanning range or observation section according to the size of the substrates. Can be easily set.

[0034]

As described above, according to the present invention, the member to be inspected is partially illuminated in accordance with the emission direction of the illuminating light beam which can be changed, so that even if the member to be inspected becomes large, The entire surface of the substrate can be irradiated evenly, and macro observation for inspecting for scratches and dirt can be performed. Further, since only one set of the illumination optical system including the illumination light source and the optical means is provided, the number of parts can be reduced, the device can be reduced in size, and the cost can be reduced.

Further, even if the member to be inspected becomes larger, the entire surface of the member to be inspected can be irradiated uniformly, so that a stable macro observation can be performed on the front surface of the non-inspection member. Furthermore, even when the sizes of the members to be inspected are different, it is possible to easily set the optimum irradiation range or observation section according to the size of the substrate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing a moving structure of an illumination light source according to the first embodiment.

FIG. 3 is a diagram for explaining an illumination state by an illumination light beam according to the first embodiment.

FIG. 4 is a diagram showing a schematic configuration of a second embodiment.

FIG. 5 is a diagram showing a schematic configuration of a third embodiment of the present invention.

FIG. 6 is a diagram showing a schematic configuration of a conventional light emitting device for visual inspection.

FIG. 7 is a diagram showing a schematic configuration of a conventional light emitting device for visual inspection.

FIG. 8 is a diagram showing a schematic configuration of a conventional light emitting device for visual inspection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body 2 ... Holder 3 ... Glass substrate 4 ... Illumination light source 5 ... Guide 6 ... Reflection mirror 7 ... Fresnel lens 71 ... 1st Fresnel lens 72 ... 2nd Fresnel lens 8.8 '. 81.82.83 ... Illumination light flux A ': Illumination position B. B '... Point P1. P2. P3: Illumination position C1. C2. C3: Observation section L1. L2: Moving distance

Claims (4)

[Claims] An illumination light source for partially illuminating a member to be inspected via a reflection mirror, and an irradiation variable means for changing an irradiation direction of an illumination light beam according to a relative positional relationship between the illumination light source and the reflection mirror. An appearance inspection light emitting device, comprising: 2. The visual inspection system according to claim 1, wherein the irradiation variable means is provided so that the illumination light source is linearly movable, and the partial illumination can be set at a plurality of positions with respect to the member to be inspected. Floodlight device. 3. The illumination variable means according to claim 1, wherein said illumination light source is provided so as to be linearly movable, and a movement range of said illumination light source is adjustable according to a size of a member to be inspected. Light projector for visual inspection. 4. The illumination variable means according to claim 1, wherein said reflecting mirror is provided so as to be swingable, and the swing angle of the reflecting mirror is adjustable according to the size of the member to be inspected. Light projector for visual inspection.