JP4576006B2 - Projection device for visual inspection - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light projection device for visual inspection used for visual inspection of a large liquid crystal glass substrate or the like.
[0002]
[Prior art]
Conventionally, in order to keep the quality of the glass substrate of the liquid crystal display stable, visual inspection such as unevenness of the film thickness of resist on the substrate and pinholes on the ITO film has been started, and irregularities and unevenness of the pattern printed on the substrate have been started. In addition, appearance inspection such as dust and scratches attached to the substrate surface is extremely important.
[0003]
Conventionally, for such visual inspection, a visual inspection light projecting device is used. Among such visual inspection light projecting devices, the film thickness unevenness of the resist on the substrate or the pin on the ITO film is used. As shown in FIG. 6, an elliptical rotating mirror 102 is disposed on the back of the light source 101 as shown in FIG. 6, and illumination light from the light source 101 is reflected by the elliptical rotating mirror 102 so that a heat ray absorption filter 103 is provided. Through the filter 105 to be incident on the condensing Fresnel lens 106 to be regulated into a parallel light beam. A glass substrate 107 is used as a member to be inspected in the parallel light beam regulated by the condensing Fresnel lens 106. The glass substrate 107 is illuminated with a predetermined angle, and the surface of the glass substrate 107 is illuminated uniformly, and the minute scattering generated from the surface of the glass substrate 107 The By visually observed observer 108, is that to detect the defect portion 109 of the pin holes on the film thickness of the unevenness and the ITO film such as a resist on a substrate.
[0004]
Further, as shown in FIG. 7, the same parts as those in FIG. 6 are given the same reference numerals as those suitable for visual inspection such as disorder or unevenness of the pattern printed on the substrate or dust or scratches attached to the substrate surface. In addition, a light projecting Fresnel lens 110 is arranged in the parallel light beam regulated by the light condensing Fresnel lens 106, and is used as a member to be inspected in the optical path before the light beam convergence position A by the light projecting Fresnel lens 110. The glass substrate 107 is arranged with a predetermined angle to illuminate the surface of the glass substrate 107 uniformly, and is generated from the surface of the glass substrate 107 from the vicinity of the convergence position S of the reflected light from the glass substrate 107. By observing minute scattered light by the observer 108 visually, the pattern printed on the substrate is disturbed or uneven, or defective portions such as dust and scratches attached to the substrate surface. 11 is that to detect the.
[0005]
By the way, recently, liquid crystal displays have been increasing in size, and along with this, glass substrates used for the liquid crystal display are also increasing in size.
However, in any of the above-described configurations, when the glass substrate is enlarged, a condensing Fresnel lens 106 and a light projecting Fresnel lens 110 that are equal to or larger than the size of the glass substrate at this time are required. The condensing Fresnel lens 106 and the projecting Fresnel lens 110 tend to become larger and larger. In the current technology, making the lens diameter larger than necessary is difficult to manufacture in order to keep the lens performance constant, and it is also difficult to illuminate the glass substrate 107 evenly. There is a problem that the reliability of the appearance inspection is lowered. In addition, when a large condensing Fresnel lens 106 and a light projecting Fresnel lens 110 are used, the focal length also increases. Therefore, in the case of the vertical type as shown in the figure, the dimension in the height direction becomes remarkably large, and the apparatus There was a problem that enlargement was inevitable.
[0006]
Therefore, recently, what is disclosed in Japanese Patent Application Laid-Open No. 9-273996 is considered as a countermeasure to the increase in size of the glass substrate. FIG. 8 shows a schematic configuration of such a light inspection apparatus for visual inspection, which has two light sources 121 and 125, and the illumination light from one of the light sources 121 is reflected by an elliptical rotating mirror 122, and a heat ray absorbing filter. 123, the gate 124, the filter 130, and one of the condensing Fresnel lenses 132 is irradiated to one of the condensing Fresnel lenses 1321. Similarly, the illumination light from the other light source 125 is applied to the elliptical rotating mirror. The light is reflected at 126, and is irradiated from the gate 129 through the heat absorbing filter 128 through the filter 131 to the other divided condensing Fresnel lens 1322 of the condensing Fresnel lens 132. Further, the parallel light flux regulated by the split condensing Fresnel lenses 1321 and 1322 is further irradiated to the split light projecting Fresnel lenses 1331 and 1332 of the light projecting Fresnel lens 133, and the surface of the glass substrate 135 is irradiated as a convergent light flux. Like to do. In this case, the respective light axes 1321a and 1322a of the split condensing Fresnel lenses 1321 and 1322 are arranged to be shifted by a predetermined angle with respect to the illumination light axes 121a and 125a of the light sources 121 and 125, respectively. The light source image position is made to coincide with the convergence position A of the luminous flux by the divided light projecting Fresnel lenses 1331 and 1332, and from this state, the vicinity of the convergence position S of the reflected light from the glass substrate 135 is changed to the position on the glass substrate 135. By observing minute scattered light caused by the defective portion 136 by visual observation of an observer 137, the defective portion 136 such as a disorder or unevenness of a pattern printed on the substrate or dust or scratch attached to the substrate surface is detected. Like to do.
[0007]
[Problems to be solved by the invention]
However, in this configuration, since it is necessary to arrange a plurality of illumination optical systems including a light source, an elliptical rotating mirror, a heat ray absorption filter, etc., the number of parts increases and the apparatus becomes larger. There was a problem that the price became expensive.
[0008]
The present invention has been made in view of the above circumstances, and can provide a light inspection apparatus for visual inspection that can illuminate the whole large-sized member evenly and that is simple in structure and inexpensive in price. The purpose is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the light projection device for visual inspection according to the present invention is configured such that a holder holding a glass substrate is inclined at a predetermined angle, and an illumination light beam is irradiated from above the glass substrate held by the holder. In the visual inspection apparatus for visually inspecting the glass substrate surface, the apparatus main body for storing the holder, a reflection mirror disposed above the holder, and a reflection surface of the reflection mirror are disposed to face the reflection mirror. an illumination light source for partial illumination to the substrate via a mirror, disposed between the said reflecting mirror holder, fixed Fresnel lens having a single optical axis for converging the illumination light from the illumination light source And the illumination light source is moved along the reflection surface of the reflection mirror so that the illumination light beam converged through the Fresnel lens is scanned over the entire surface of the glass substrate. So, the irradiation direction of a predetermined angle tilt as to the illumination light beam so as to scan the illumination light on the substrate in accordance with the movement position of the illumination source with respect to the optical axis of the optical axis is the Fresnel lens of the illumination light source It is comprised by the irradiation variable means which varies.
[0013]
As a result, according to the present invention, it is possible to uniformly illuminate the entire surface of the large non-inspection member even with a small light source by changing the irradiation direction of the partial illumination, and illumination optics including the illumination light source and the optical means Since only one 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 member to be inspected, the entire surface of each member to be inspected can be illuminated uniformly.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a schematic configuration of an appearance inspection light projecting apparatus to which the present invention is applied. In the figure, reference numeral 1 denotes an apparatus main body, and a holder 2 is arranged inside the apparatus main body 1 as a member to be inspected. The holder 2 holds a large glass substrate 3 used for a flat display such as an LCD as a member to be inspected. The end of the apparatus body 1 on the front side is rotatably supported. It is possible to rise and fall within a predetermined angle range.
[0015]
An illumination light source 4 made of, for example, a metal halide lamp is provided above the apparatus main body 1. The illumination light source 4 can be reciprocated by a driving means (not shown) along a guide 5 disposed along the width direction of the apparatus body 1 as shown in FIG. They are positioned at the illumination position A indicated by the solid line and the illumination position A ′ indicated by the dashed line, respectively. When the illumination light source 4 is located at the illumination position A by movement along the guide 5, the illumination light source 4 is inclined with respect to the center line O by an angle θ, and when it is at the illumination position A ′, In contrast, it is inclined with respect to the angle θ ′.
[0016]
In the illustrated example, the reflecting mirror 6 is disposed at an angle of 45 ° so as to face the illumination light source 4 so that the light from the illumination light source 4 is reflected and applied 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 flux from the illumination light incident from the reflection mirror 6, and the second Fresnel lens 71 The Fresnel lens 72 has 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. The glass substrate 3 is irradiated with the illumination light beams 8 and 8 ′ that converge at (1). That is, when the illumination light source 4 is at the illumination position A, the second Fresnel lens 72 emits the illumination light beam 8 that illuminates the surface indicated by the oblique lines in FIG. 3A of the glass substrate 3, and the illumination light source 4 is illuminated. In the position A ′, an illumination light beam 8 ′ that illuminates the surface of the glass substrate 3 indicated by the oblique lines in FIG. 3B is emitted.
[0017]
Next, the operation of the embodiment configured as described above will be described.
First, the glass substrate 3 as a member to be inspected is placed and held on the holder 2, and the holder 2 is raised and inclined at a predetermined angle according to the height of the line of sight of the observer as shown in FIG. In this state, as shown in FIG. 2, when the illumination light source 4 is moved to the illumination position A at one end of the guide 5, the optical axis of the illumination light source 4 is inclined by an angle θ with respect to the center line O.
[0018]
Then, the light from the illumination light source 4 is reflected by the reflection mirror 6, is emitted as a parallel light beam from the first Fresnel lens 71, and is further emitted as an illumination light beam 8 that converges at the point B from the second Fresnel lens 72. The surface shown by the oblique lines in FIG. 3A of the glass substrate 3 on the holder 2 is irradiated. Thereby, a macro inspection by visual inspection is performed on the substrate surface including the left half irradiated with the illumination light beam 8 for scratches and dirt.
[0019]
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 driving means (not shown), the optical axis of the illumination light source 4 is inclined by the angle θ ′ with respect to the center line O. .
[0020]
Then, the light from the illumination light source 4 is reflected by the reflection mirror 6, is emitted as a parallel light beam from the first Fresnel lens 71, and is further emitted as an illumination light beam 8 ′ converged at the point B from the second Fresnel lens 72. Then, the surface shown by the oblique lines in FIG. As a result, a macro inspection by visual inspection is performed on the substrate surface including the right half irradiated with the illumination light beam 8 ′ for scratches and dirt.
[0021]
Therefore, if this is done, the illumination light source (partial illumination) can be scanned by moving the illumination light source 4 along the guide 5. Further, by switching the illumination light source 4 to the illumination positions A and A ′, even when the glass substrate 3 becomes large, the entire surface of the substrate can be irradiated evenly, and a macro for inspecting scratches and dirt. Observations can be made. In addition, since only one set of the 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 can be reduced, and the apparatus can be downsized. The price can be reduced. Furthermore, since the illumination area on the substrate surface can be reduced by using partial illumination, an illumination light source with low power can be used to obtain the same level of brightness.
[0022]
In the above-described embodiment, the entire surface of the glass substrate 3 can be irradiated by moving the illumination position of the illumination light source 4. However, the reflection angle of the reflection mirror 6 is adjusted and the reflection mirror 6 reflects the light. Even if the entire surface of the glass substrate 3 can be irradiated by the illumination light beam, the same effect as described above can be obtained.
(Second Embodiment)
4 (a) and 4 (b) show a schematic configuration of the second embodiment of the present invention, and the same reference numerals are given to the same portions as FIG.
[0023]
In this case, the illumination light source 4 can be positioned at a plurality of illumination positions P1, P2, and P3 along the width direction of the apparatus main body 1 as shown in FIG. Further, the glass substrate 3 is set so 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). It has become.
[0024]
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, a plurality of observations are performed according to the outer shape data at this time, for example, as shown in FIG. Sections C1, C2, and C3 are set.
[0025]
When the illumination light source 4 is turned on from this state, the illumination light source 4 is moved to the illumination position P1 along the width direction of the apparatus body 1 by a control signal from the control device, and on the glass substrate 3 by the illumination light beam 81 at this time The area including the observation section C1 is illuminated. 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 is completed, the illumination light source 4 is moved to the illumination light illumination position P2, and the observation section C2 on the glass substrate 3 is irradiated with the illumination light beam 82, and this time, Macro observation can be performed in the observation section C2. Further, when the macro observation in the observation section C2 is finished, the illumination light source 4 is moved to the illumination light illumination position P3, and the illumination section 83 irradiates the observation section C3 on the glass substrate 3, and the observation section C3. Macro observation can be performed at
[0026]
In this way, by sequentially moving the illumination light source 4 to the illumination positions P1, P2, and P3, the divided observation sections C1, C2, and C3 of the glass substrate 3 can be sequentially irradiated. Macro observation can be performed on the entire surface.
[0027]
Accordingly, even if the glass substrate 3 is further increased in size, the entire surface of the glass substrate 3 can be illuminated uniformly with a small illumination light source. In addition, by dividing the same substrate into multiple observation sections, it is possible to concentrate and visually observe each observation section, so that the observation accuracy can be improved and the observer's eye movement is reduced and fatigue is suppressed. Can do.
[0028]
In the above-described embodiment, the example in which the glass substrate 3 is divided into the three sections of the observation sections C1, C2, and C3 has been described. However, it may be set to three sections or more. In this case, the illumination position by the illumination light source 4 is also four or more.
(Third embodiment)
5 (a) and 5 (b) show a schematic configuration of the third embodiment of the present invention, and the same parts as those in FIG.
[0029]
In this case, the illumination light source 4 inputs the external shape data according to the size of the glass substrate 3 to a control device (not shown), and thereby follows the width direction of the device main body 1 as shown in FIGS. The moving distance can be switched between L1 and L2.
[0030]
In such a configuration, the observer inputs outline data to the control device in accordance with the size of the glass substrate 3, but now when the outside dimension of the glass substrate 3 is large as shown in FIG. Depending on the external shape data at this time, the moving distance of the illumination light source 4 is set to L1.
[0031]
In this state, when the illumination light source 4 is turned on, the illumination light source 4 moves by a movement distance L1 according to a control signal from the control device. By moving the illumination light source 4 within this movement range L1, the outer dimensions of the illumination light source 4 are moved. The entire surface of the large glass substrate 3 can be irradiated.
[0032]
Further, when the outer dimension of the glass substrate 3 is small as shown in FIG. 5B, the moving distance L2 of the illumination light source 4 is set according to the outer shape data at this time. When the illumination light source 4 is turned on from this state, the illumination light source 4 is moved by a movement distance L2 by a control signal from the control device. By moving the illumination light source 4 within this movement range L2, the outer dimensions are obtained. Can irradiate the entire surface of the glass substrate 3.
[0033]
In this way, even when the sizes of the glass substrates 3 are different, the entire surface of each glass substrate 3 can be irradiated evenly, and an optimal illumination scanning range or observation section corresponding to the size of the substrate can be easily obtained. Can be set.
[0034]
【The invention's effect】
As described above, according to the present invention, since the member to be inspected is partially illuminated in accordance with the changeable direction of the illumination light beam, even if the member to be inspected becomes large, the entire surface of the substrate is not uneven. Irradiation is possible, and macro observation for inspecting 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 apparatus can be downsized, and the price can be reduced.
[0035]
Further, even when the member to be inspected is further increased in size, the entire surface of the member to be inspected can be irradiated evenly, so that 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 an optimal irradiation range or observation section corresponding 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 the 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 visual inspection projector.
FIG. 7 is a diagram showing a schematic configuration of a conventional visual inspection projector.
FIG. 8 is a diagram showing a schematic configuration of a conventional visual inspection projector.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Apparatus 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 '. 81.2.83 ... Illumination luminous flux A ′: Illumination position B. B '... Point P1. P2. P3: Illumination position C1. C2. C3 ... Observation section L1. L2 ... Movement distance

Claims (4)

In the appearance inspection apparatus that inclines the holder holding the glass substrate at a predetermined angle, irradiates the illumination light beam from above the glass substrate held by the holder, and visually inspects the irradiated glass substrate surface,
An apparatus main body for storing the holder;
A reflection mirror disposed above the holder;
An illumination light source that is disposed opposite to the reflection surface of the reflection mirror and that partially illuminates the substrate through the reflection mirror;
Disposed between the said reflecting mirror holder, a fixed Fresnel lens having a single optical axis for converging the illumination light from the illumination source,
The illumination light source is moved along the reflection surface of the reflection mirror so that the illumination light beam converged through the Fresnel lens is scanned over the entire surface of the glass substrate, and the optical axis of the illumination light source is the Fresnel An irradiation variable means for changing the irradiation direction of the illumination light beam so as to incline at a predetermined angle with respect to the optical axis of the lens and to scan the illumination light on the substrate according to the movement position of the illumination light source;
A projection device for visual inspection characterized by comprising: 2. The appearance according to claim 1 , wherein the irradiation variable unit moves the illumination light source to each illumination position that illuminates a plurality of observation sections set on the substrate in accordance with outline data of the substrate. Inspection floodlight. The light projection device for appearance inspection according to claim 1 , wherein the irradiation variable unit sequentially moves the illumination light source to a plurality of illumination positions determined in accordance with outline data of the substrate. The irradiation varying means, the movement range of the illumination light source in accordance with the contour data of the substrate is set, the appearance inspection of claim 1, characterized in that moving the illumination source within the range of movement of this Floodlight device.

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