JP2000249659A - Flaw inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a flaw under a favorable condition by properly moving a mirror according to the kind of a sheetlike object to be inspected or according to the formation way of the flaw in a flaw inspection apparatus, in which the sheetlike object to be inspected is irradiated with mirror reflected light from the rear side and in which the flaw of the object to be inspected is inspected. SOLUTION: A holding member 12 which holds the peripheral part of an object 2 to be inspected is provided. In addition, a light source unit 14 which is installed on the rear side of the object 2 to be inspected is provided. A mirror 16 by which the rear of the object 2 to be inspected is irradiated with horizontal parallel light from the light source unit 14 is provided. In addition, a camera 18 which observes the flaw of the object 2 to be inspected, by imaging the object 2 to be inspected from the surface side is provided. Then, a mirror movement mechanism 32 by which the mirror 16 is moved in such a way that the angle of incidence of the horizontal parallel light from the light source unit 14 is changed, while an irradiation state to the rear of the object 2 to be inspected is being maintained, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flaw inspection apparatus for inspecting a flaw of a plate-like inspection object, particularly in a dark field.

[0002]

2. Description of the Related Art Conventionally, as a flaw inspection apparatus for inspecting a flaw of a plate-like inspection object, as shown in FIG. A light source 104 provided on the back side of the device, a mirror 106 for reflecting the light from the light source 104 so as to irradiate the back surface of the device 2, and an image of the device 2 to be inspected by imaging the device 2 from the front side A camera equipped with a camera 108 for observing a wound on the body 2 is known.

[0003] The flaw inspection apparatus is configured to perform dark-field illumination so that the flaw of the inspection object 2 can be clearly observed. That is, camera 1
By inclining the optical axis Ax2 ′ of the reflected light from the mirror 106 illuminated on the back surface of the test object 2 with respect to the optical axis Ax1 of 08 at a predetermined angle, the illuminated light is not directly incident on the camera 108. I have.

[0004]

The object to be inspected 2
Can be observed most clearly by the scattered light (dark-field observation) when the incident angle of the irradiation light on the back surface of the test object 2 reaches a certain angle.
This angle has a different value depending on the type of the inspected object 2 and the manner of scratching.

However, in the above-mentioned conventional flaw inspection apparatus, since the angle of the mirror 106 is fixed, the flaw detection by the camera 108 cannot be performed under favorable conditions in many cases.

The present invention has been made in view of such circumstances, and provides a flaw inspection apparatus capable of detecting flaws under favorable conditions in accordance with the type of an object to be inspected and the manner in which flaws are formed. It is intended to do so.

[0007]

According to the present invention, there is provided a flaw inspection apparatus comprising:
The above object is achieved by using a predetermined mirror moving mechanism.

[0008] That is, a flaw inspection device of the present invention is a device for inspecting a flaw of a plate-shaped test object, comprising a holding member for holding a peripheral portion of the test object, and a back side of the test object. And a mirror for reflecting light from the light source so as to irradiate the back surface of the test object, and observing a defect of the test object by imaging the test object from the front side. An apparatus comprising a camera, wherein a mirror moving mechanism for moving the mirror so as to change an incident angle of light from the light source while maintaining an irradiation state on the back surface of the inspection object is provided. It is characterized by the following.

In addition, first and second pins are formed on both end surfaces of the mirror so as to protrude at a predetermined interval.
The mirror moving mechanism includes a fixed body having a cam groove that engages with the first pin, and a moving body connected to the second pin and movably provided with respect to the fixed body. Preferably, it is provided.

An aperture provided in the optical path on the light source side with respect to the mirror, and an aperture moving mechanism for moving the aperture in a direction substantially orthogonal to the optical path in conjunction with the movement of the mirror. Preferably, it is provided.

Further, a light source holding / rotating member for rotatably holding the light source so as to take a predetermined position on the back side of the object to be inspected and a predetermined position on the front side of the object to be inspected is provided. Preferably,

The type of the "object to be inspected" is not particularly limited as long as it is a plate-shaped optical member.
For example, a filter on which an anti-reflection coating film is formed, ND
A filter, a polarizing plate, a wave plate and the like can be adopted.

The "mirror moving mechanism" is not particularly limited as long as the mirror is moved so as to change the incident angle of light from the light source while maintaining the state of irradiation on the back surface of the test object. The physical configuration is not particularly limited, and for example, a configuration using a cam, a link, a gear, or the like can be adopted.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a flaw inspection apparatus 10 according to one embodiment of the present invention.

1, a flaw inspection apparatus 10 is an apparatus for inspecting a flaw (pinhole or the like) of a plate-like inspection object (for example, a filter on which an antireflection coating film is formed) 2 in a dark field. A holding member 12 for holding a peripheral portion of the device under test 2, a light source unit 14 provided on the back surface of the device under test 2, A mirror 16 for reflecting light so as to irradiate the object 2, a camera 18 for observing a scratch on the object 2 by imaging the object 2 from the front side, and a camera 18
And a monitor 20 for displaying on the screen 20a the image of the test object 2 captured by the computer.

The camera 18 is arranged right above the test object 2 so that its optical axis Ax1 passes through the center of the test object 2. However, the camera 18 can be rotated over a predetermined angle range around the center position of the device under test 2 as necessary, as indicated by arrows in the drawing.

The light source unit 14 includes the laser diode 2
2 (light source), a collimator lens 24, and a lens barrel 26, and rotate so as to be able to take a predetermined position on the back surface side of the device under test 2 and a predetermined position on the front surface side of the device under test as shown in the figure. It is provided as possible. At this time, the optical axis Ax2 of the light source unit 14 is positioned at a position extending in the horizontal direction on the back surface side of the inspection object 2, and the light source unit is located on the front surface side of the inspection object 2. 14
Optical axis Ax2 extends in the vertical direction of the camera 18
It can be positioned at any angle position that forms a predetermined angle with respect to 1.

In an optical path on the light source unit 14 side with respect to the mirror 16, an aperture 2 having a rectangular opening 28a is formed.
8 are provided. The aperture 28 is provided so as to be movable in the vertical direction as described later.

First and second pins 30A and 30B are formed on both end surfaces of the mirror 16 at predetermined intervals so as to protrude therefrom. The mirror 16 is connected to the mirror moving mechanism 32 via the pins 30A and 30B. Supported.

FIG. 2 is a perspective view showing the mirror moving mechanism 32. As shown in the figure, the mirror moving mechanism 32 is connected to a casing 34 (fixed body) having a cam groove 34a engaged with the first pin 30A and a second pin 30B. And a slider 36 (moving body) slidably provided. The mirror moving mechanism 32 moves the mirror 16 to the light source unit 1 while maintaining the state of irradiation of the back surface of the test object 2.
4 so as to change the angle of incidence of the horizontal parallel light.

The cam groove 34a is formed in a substantially arc shape on both side walls of the casing 34. On the other hand, the slider 36
The second pin 30 is slid in a direction parallel to the optical axis Ax2.
B is rotatably supported. By sliding the slider 36, the first pin 30A is moved along the cam groove 34a, thereby changing the tilt angle of the mirror 16.

As shown in FIGS. 3 (a) and 3 (b), the angle of inclination of the mirror 16 changes the angle of incidence of the horizontal parallel light from the light source unit 14 on the mirror 16, and accordingly the mirror 16 The position and shape of the cam groove 34a are set so that the reflected light from the mirror 16 always irradiates the back surface of the test object 2, although the optical axis Ax2 'of the reflected light from the mirror changes. I have. At that time, the casing 3
The aperture 28 disposed on the end face of the light source unit 14 on the light source unit 14 side moves in the vertical direction in conjunction with the movement of the mirror 16, and the paraxial ray bundle of the optical axis Ax2 deviates from the upper end edge of the mirror 16. To prevent it.

FIGS. 4A and 4B show an aperture 2
FIG. 9 is a side view showing an aperture moving mechanism 38 that moves the aperture 8 vertically.

As shown, the aperture moving mechanism 38
Is composed of pantograph-shaped links 40 and 42 arranged adjacent to both side walls of the casing 34. The link 40 has a casing 34 at its lower end.
Are rotatably connected to the lower wall of the
A cam groove 40a into which the first pin 30A of the mirror 16 is inserted and engaged is formed above the second link connecting shaft 44. On the other hand, the link 42 is rotatably connected at an upper end thereof to a portion above the rectangular opening 28a of the aperture 28, and has a casing 3 at a lower end thereof.
4 is in contact with the lower wall.

In this aperture moving mechanism 38,
When the first pin 30A moves along the cam groove 34a of the casing 34, the crossing angle of the links 40 and 42 changes due to a change in the engagement position of the first pin 30A with the cam groove 40a of the link 40. Link 42
Is moved in the vertical direction. The cam groove 40 a of the link 40 is shaped so that light passing near the upper end edge of the rectangular opening 28 a of the aperture 28 is incident on a portion near the upper end edge of the mirror 16.

As shown in FIG. 5, in this embodiment, the holding member 12 of the device under test 2 is formed in a turret shape, and is supported on the upper surface of the apparatus main body 46 so as to be rotatable around its central axis 48. ing. The holding member 12 holds a plurality of test objects 2 at a constant angular interval on the same circumference. In addition, a pair of finger insertion notches 12 for facilitating attachment / detachment of the test object 2 is formed in the test object holding opening 12 a of the holding member 12.
b is formed. The surfaces of the holding member 12 and the device main body 46 are coated with a black matte paint.

A camera holding and rotating member 50 for rotatably holding the camera 18 is provided on one side surface of the apparatus main body 46.
A light source holding / rotating member 52 that holds the light source unit 14 in a rotatable manner is attached.

As described in detail above, in the flaw inspection apparatus 10 according to the present embodiment, the angle of incidence of the horizontal parallel light from the light source unit 14 is controlled while maintaining the mirror 16 in the state of irradiating the back surface of the inspection object 2. The mirror moving mechanism 32 that moves so as to change the angle is set so that the angle of incidence of the irradiation light on the back surface of the inspection object 2 is set to an angle at which the scratch on the inspection object 2 can be most clearly observed. be able to.

Therefore, according to the present embodiment, the flaw detection can be performed under favorable conditions by appropriately moving the mirror 16 in accordance with the type of the inspection object 2 and the manner of flaws.

Moreover, in this embodiment, the mirror 1
The first and second pins 30A and 30B are formed on both side end surfaces of the first and second protrusions at predetermined intervals, and the mirror moving mechanism 32 is provided with a cam groove 3 which engages with the first pin 30A.
4a and the second pin 30B
And a slider 36 slidably provided with respect to the casing 34, so that the inclination angle of the mirror 16 can be changed steplessly with a simple configuration.

In this embodiment, the mirror 16
And an aperture moving mechanism 38 that moves the aperture 28 provided in the optical path on the light source unit 14 side up and down in conjunction with the movement of the mirror 16.
The movement of the mirror 16 can prevent the horizontal parallel light from the light source unit 14 from deviating from the upper edge of the mirror 16, thereby preventing the leak light from entering the camera 18. .

Further, in the present embodiment, the light source unit 14 is rotatably held so as to be able to take a predetermined position on the back surface side of the test object 2 and a predetermined position on the front surface side of the test object 2. Since the light source holding / rotating member 52 is provided, the flaw of the inspection object 2 can be inspected by both transmitted light and reflected light.

In the present embodiment, the camera 18
Is arranged right above the test object 2,
Since the camera holding / rotating member 50 can rotate around the center position of the inspection object 2, the mirror 16 is
Even when the tilt angle is such that the horizontal parallel light from the light source unit 14 is reflected directly above the back surface of the test object 2, the camera 18 is appropriately shifted to an angle at which the irradiation light from the mirror 16 is not incident. be able to.

In the above embodiment, the mirror 16 is configured so that the horizontal parallel light from the light source unit 14 is incident. However, the optical axis Ax2 does not necessarily have to be set to extend in the horizontal direction. Further, diffused light or focused light may be incident instead of parallel light.

[0035]

According to the flaw inspection apparatus of the present invention, light from a light source provided on the back side of the inspection object held by the holding member is reflected by a mirror so as to irradiate the rear surface of the inspection object. It has a mirror moving mechanism that moves this mirror so as to change the angle of incidence of light from the light source while maintaining the state of irradiation on the back surface of the device under test. Can be set to an angle at which a flaw on the object to be inspected can be most clearly observed. Therefore, according to the present invention, the flaw detection can be performed under favorable conditions by appropriately moving the mirror in accordance with the type of the object to be inspected and the manner in which the flaw is formed.

[Brief description of the drawings]

FIG. 1 is a side view showing a flaw inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a mirror moving mechanism of the flaw inspection device in FIG. 1;

FIG. 3 is a side view showing the operation of the mirror moving mechanism in FIG. 3;

FIG. 4 is a side view showing an aperture moving mechanism of the flaw inspection device in FIG.

FIG. 5 is a perspective view showing the scratch inspection device of FIG. 1;

FIG. 6 is a schematic diagram showing a conventional example.

[Explanation of symbols]

 2 Inspection object 10 Scratch inspection device 12 Holding member 12a Inspection object holding opening 12b Notch for finger insertion 14 Light source unit 16 Mirror 18 Camera 20 Monitor 20a Screen 22 Laser diode (light source) 24 Collimator lens 26 Lens tube 28 Aperture 28a rectangular opening 30A first pin 30B second pin 32 mirror moving mechanism 34a cam groove 34 casing (fixed body) 36 slider (moving body) 36a bracket 38 aperture moving mechanism 40, 42 link 40a cam groove 44 link connecting shaft 46 Device main body 48 Central axis 50 Camera holding and rotating member 52 Light source holding and rotating member Ax1, Ax2, Ax2 'Optical axis

Continued on the front page (72) Inventor Chihiro Furuhata 1-39, Kamo-cho, Okaya-shi, Nagano Prefecture Inside Okaya Fujikoki Co., Ltd. (72) Inventor Shinichi Matsuda 1-3324 Uetake-cho, Omiya-shi, Saitama Fuji Photo F term (reference) in Koki Co., Ltd.

Claims (4)

[Claims] 1. A device for inspecting a plate-like inspected object for flaws, comprising: a holding member for holding a peripheral portion of the inspected object; a light source provided on a back surface side of the inspected object; A flaw inspection comprising: a mirror for reflecting light from a light source so as to irradiate a back surface of the test object; and a camera for observing a flaw of the test object by imaging the test object from the front side. The apparatus according to claim 1, further comprising a mirror moving mechanism configured to move the mirror so as to change an incident angle of light from the light source while maintaining an irradiation state on a back surface of the inspection object. apparatus. 2. A cam groove for engaging the first pin with the mirror moving mechanism, wherein first and second pins are formed on both end surfaces of the mirror so as to protrude at a predetermined interval. The flaw inspection apparatus according to claim 1, further comprising a fixed body connected to the second pin and a movable body movably provided with respect to the fixed body. 3. An aperture provided in an optical path on the light source side with respect to the mirror, and an aperture moving mechanism for moving the aperture in a direction substantially orthogonal to the optical path in conjunction with movement of the mirror. The flaw inspection device according to claim 1 or 2, further comprising: 4. A light source holding and rotating member for rotatably holding the light source so as to take a predetermined position on the back surface side of the inspection object and a predetermined position on the front surface side of the inspection object. The flaw inspection device according to any one of claims 1 to 3, wherein: