JP2008216150A - Inspection device and method of transparent object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device and an inspection method of a transparent object capable of inspecting simultaneously both the surface and the inside of a transparent inspection object with a simple constitution. <P>SOLUTION: This device is equipped with (a) a light emitting part 14 for irradiating the transparent inspection object 2 surface 2a with a light flux 15a from an oblique direction, and moving an irradiation position 15s linearly, (b) a light receiving part having a light receiving window 16s extending linearly oppositely to the irradiation position 15s on the same side as the light emitting part 14 relative to the inspection object 2, for detecting intensity of a light flux component passing the light receiving window 16s, and (c) a determination part for determining the quality of the inspection object based on the intensity of the light flux component detected by the light receiving part. The light receiving window 16s is widened so as to be transmissible simultaneously by both components, namely, the regularly-reflected light component 15b acquired from the light flux 15a by being regularly reflected by the inspection object 2 surface 2a on the irradiation position 15s as a light flux component, and an internal reflected component 15e acquired from a process wherein the light flux 15a enters the inside of the inspection object 2 from the irradiation position 15s, and is reflected by the back surface 2b, and then emitted from the surface 2a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transparent inspection apparatus and inspection method, and more particularly, to an inspection apparatus and inspection method for optically inspecting the surface and the inside of a transparent inspection object.

  Conventionally, various inspection apparatuses for optically inspecting transparent inspection objects have been proposed.

  For example, the inspection apparatus disclosed in Patent Document 1 irradiates the surface of a glass substrate obliquely with strip-shaped inspection light, collects reflected light and scattered light from the back surface of the glass substrate, and provides a slit to provide scattered light. Is configured such that only the reflected light is imaged on the light receiving surface of the CCD line sensor, and a scratch on the back surface of the glass substrate is detected.

Patent Document 2 discloses that a plate-like inspection object is irradiated with a laser beam obliquely, and scattered light generated by a defect inside the inspection object is observed from above the inspection object with a microscope. Has been.
JP 2005-156416 A JP-A-4-24541

  Since these inspection apparatuses require an imaging optical system that focuses on the inspection target portion, the configuration is complicated, and assembly and adjustment are difficult. Further, since the inspection target part is limited by the focal depth of the imaging optical system, it is impossible to inspect both the surface and the inside of the inspection object at the same time.

  In view of such circumstances, the present invention is intended to provide a transparent inspection apparatus and inspection method capable of simultaneously inspecting both the surface and the inside of a transparent inspection object with a simple configuration.

  In order to solve the above-described problems, the present invention provides a transparent inspection apparatus configured as follows.

  The transparent inspection apparatus includes: (a) a light emitting unit that irradiates a light beam on the surface of a transparent inspection object from an oblique direction and moves the irradiation position of the light beam linearly; and (b) the above-described inspection object. A light receiving portion that has a light receiving window extending linearly facing the irradiation position on the same side as the light emitting portion, and (c) the light receiving portion detects the light receiving portion that detects the intensity of the light beam component that has passed through the light receiving window. And a determination unit that determines the quality of the inspection object based on the intensity of the luminous flux component. The light receiving window includes, as the light flux component, a specularly reflected light component in which the light flux is specularly reflected on the surface of the inspection object at the irradiation position, and the light beam is incident on the inspection object at the irradiation position. And after reflecting on the back surface of the said to-be-inspected object, it forms so that both the internal reflection component radiate | emitted from the said surface of the to-be-inspected object may pass simultaneously.

  In the above configuration, when the inspection object is moved relative to the light emitting unit and the light receiving window, the surface of the inspection object can be inspected continuously.

  According to the above configuration, if there are no defective parts such as foreign matter, coating peeling, chipping, bubbles, etc. on the surface or inside of the object to be inspected, the light receiving window passes the specular reflection component and the internal reflection component with the maximum intensity. The intensity of the light beam component received by the unit is constant and maximum. On the other hand, if there is a defective part such as a foreign object, coating peeling, chipping, or bubble on the surface or inside of the inspection object, the intensity of the specular reflection component and / or internal reflection component due to the generation of scattered light at the defective part is reduced. Or, the optical path of the specular reflection component and / or the internal reflection component changes at the defective part and the specular reflection component and / or the internal reflection component deviates from the light receiving window, so that the intensity of the light beam component received by the light receiving unit is reduced. To do. If there is such a decrease in the intensity of the luminous flux component, it can be determined that a defective portion exists on the surface or inside of the inspection object.

  According to the above configuration, both the surface and the inside can be inspected simultaneously without using an imaging optical system focused on the surface or inside of the object to be inspected, and the configuration can be simplified. Further, the light receiving window can be arranged close to the irradiation position, that is, the surface of the object to be inspected, and the configuration can be reduced in size. Furthermore, since it is not necessary to adjust the focus of the imaging optical system, assembly and adjustment are easy.

  Preferably, a pattern is formed on the back surface of the inspection object.

  The intensity of the specular reflection component and the internal reflection component hardly change even if a pattern is formed on the back surface of the object to be inspected or a pattern is not formed. Therefore, even if a transparent object to be inspected has a pattern formed on the back surface, the front surface and the inside can be inspected simultaneously.

  Moreover, in order to solve the said subject, this invention provides the inspection method of the transparent material comprised as follows.

  The transparent object inspection method includes (1) a first step of irradiating the surface of a transparent inspection object with a light beam from an oblique direction, and moving the irradiation position of the light beam in a linear manner, and (2) at the irradiation position. A second step of detecting the intensity of the light beam component that has passed through the light receiving window extending in a facing line; and (3) the inspection target based on the intensity of the light beam component detected in the second step. And a third step of determining the quality of the object. The light receiving window includes, as the light flux component, a specularly reflected light component in which the light flux is specularly reflected on the surface of the inspection object at the irradiation position, and the light beam is incident on the inspection object at the irradiation position. And after reflecting on the back surface of the said to-be-inspected object, it forms so that both the internal reflection component radiate | emitted from the said surface of the to-be-inspected object may pass simultaneously.

  In the above method, when the inspection object is moved relative to the light emitting unit and the light receiving window, the surface of the inspection object can be inspected continuously.

  According to the above method, the specular reflection component and the internal reflection component with the maximum intensity pass through the light receiving window if there are no defective parts such as foreign matter, coating peeling, chipping or bubbles on the surface or inside of the inspection object. The intensity of the light beam component detected in step 2 is constant and maximum. On the other hand, if there is a defective part such as a foreign object, coating peeling, chipping, or bubble on the surface or inside of the inspection object, the intensity of the specular reflection component and / or internal reflection component due to the generation of scattered light at the defective part is reduced. Or, the intensity of the light flux component detected in the second step by changing the optical path of the specular reflection component and / or the internal reflection component at the defective portion and causing the specular reflection component and / or the internal reflection component to deviate from the light receiving window. Decreases. If there is such a decrease in the intensity of the light beam component, it can be determined in the third step that there is a defective portion on the surface or inside of the inspection object.

  According to the above method, both the surface and the inside can be inspected simultaneously without using an imaging optical system focused on the surface or inside of the object to be inspected, and the configuration can be simplified. Further, the light receiving window can be arranged close to the irradiation position, that is, the surface of the object to be inspected, and the configuration can be reduced in size. Furthermore, since it is not necessary to adjust the focus of the imaging optical system, assembly and adjustment are easy.

Preferably, a pattern is formed on the back surface of the inspection object.
The intensity of the specular reflection component and the internal reflection component hardly change even if a pattern is formed on the back surface of the object to be inspected or a pattern is not formed. Therefore, even if a transparent object to be inspected has a pattern formed on the back surface, the front surface and the inside can be inspected simultaneously.

  According to the present invention, since the imaging optical system is unnecessary, it is possible to simultaneously inspect both the surface and the inside of a transparent inspection object with a simple configuration.

  Hereinafter, examples of the present invention will be described with reference to FIGS.

  As shown in the perspective view of FIG. 1, the inspection apparatus 10 irradiates the surface 2a of the inspection object 2 conveyed in the direction indicated by the arrow 3 by the conveyance apparatus 4 with a laser beam 15a from the light emitting unit 14 and reflects it. The light 15 b is incident on the light receiving unit main body 16.

  The light emitting unit 14 moves the laser beam 15a, which is a parallel light beam focused to a desired spot diameter, in a fan shape as indicated by an arrow 15p. The irradiation position 15 s of the laser beam 15 a moves linearly on the surface 2 a of the inspection object 2. The light receiving unit main body 16 is arranged in parallel so as to face the linear irradiation position 15s.

  As indicated by reference numerals 13 and 19, the control unit 12 is connected to the light emitting unit 14 and the photodetector 18, and the light emitting unit 14 irradiates the received light amount of the specularly reflected light 15b detected by the photodetector 18. By performing signal processing in association with the irradiation angle 15p of the laser beam 15a, the position of the defect is specified. The control unit 12 performs signal processing according to a predetermined program, and determines whether the surface 2a of the inspection object 2 or the inside is good or bad.

  As schematically shown in FIG. 2, which is a cross-sectional view taken along line AA in FIG. 1, the cylindrical light receiving unit main body 16 has a rectangular shape extending linearly facing the irradiation position 15 s. A light receiving window 16s is formed. In the light receiving window 16s, an opening is formed so as to allow both the regular reflection component 15b and the internal reflection component 15e by the irradiated laser beam 15a to pass therethrough.

  That is, the laser beam 15a irradiated to the irradiation position 15s of the surface 2a of the inspection object 2 is divided into a regular reflection light component 15b specularly reflected at the irradiation position 15s and an incident component 15c incident inside the inspection object. . The regular reflection component 15b passes through the light receiving window 16s. On the other hand, the incident component 15c is reflected by the back surface 2b of the inspection object. The reflection component 15d reflected by the back surface 2b of the inspection object exits from the surface of the inspection object. The internal reflection component 15e emitted from the surface of the inspection object passes through the light receiving window 16s.

  A substantially columnar light guide 17 is disposed inside the light receiving unit main body 16 so that light beams 15b and 15e that have passed through the light receiving window 16s are incident thereon.

  A light detector 18 (see FIG. 1) is disposed opposite one end of the light guide 17 so that light incident on the light guide 17 is emitted from one end of the light guide 17 and light emitted from one end of the light guide 17. The intensity is detected by the photodetector 18.

  Although it is preferable to use a photomultiplier tube (photomal) having a very good S / N characteristic for the photodetector 18, it is not limited to this.

  A light detector may be provided at the other end of the light guide 17 so that the outputs of both light detectors are added together.

  The inspection object is, for example, a glass substrate before assembly of a liquid crystal panel or a plasma display, and is inspected in a state where a coating is formed on the front surface 2a and an opaque pattern such as a circuit is formed on the back surface 2b.

  Next, the principle of inspection of the inspection apparatus 10 will be described.

  If there are no defective parts such as foreign matter, coating peeling, chipping or bubbles on the surface 2a or the inside 2k of the object to be inspected, the regular reflection light component 15b and the internal reflection component 15e having the maximum intensity pass through the light reception window 16s. The intensity of the light beam passing through the light becomes maximum and substantially constant, and the output signal level from the photodetector 18 becomes substantially constant and maximum.

  On the other hand, if there is a defective part such as foreign matter, coating peeling, chipping, or bubble on the surface 2a or the inside 2k of the object to be inspected, the intensity of the specular reflection component and / or the internal reflection component accompanying the generation of scattered light at the defective part The intensity of the light beam passing through the light receiving window decreases due to the decrease or the optical path of the specular reflection light component and / or the internal reflection component changes at the defective part and the specular reflection light component and / or the internal reflection component deviates from the light receiving window. As a result, the output signal level from the photodetector 18 is lowered.

  If there is such a decrease in the output signal level from the photodetector 18, it is determined that there is a defective portion in the portion corresponding to the irradiation position 15s of the laser beam 15a on the surface 2a or the inside 2k of the inspection object. Can do.

  The intensity of the regular reflection component is determined by the characteristics of the surface of the inspection object and is not affected by the presence or absence of a pattern formed on the back surface of the inspection object. Further, the internal reflection component is hardly affected by the presence or absence of a pattern formed on the back surface of the inspection object. Therefore, even if a transparent inspection object has a pattern formed on the back surface, the front surface and the inside of the inspection object can be inspected simultaneously.

  The inspection apparatus 10 can inspect both the surface and the inside at the same time without using an imaging optical system focused on the surface or the inside of the inspection object. Further, the light receiving window can be arranged close to the irradiation position, that is, the surface of the object to be inspected, and the configuration can be reduced in size. Furthermore, since it is not necessary to adjust the focus of the imaging optical system, assembly and adjustment are easy.

  <Summary> As described above, since the imaging apparatus 10 is unnecessary, the inspection apparatus 10 can simultaneously inspect both the surface and the inside of the transparent inspection object with a simple configuration.

  In addition, this invention is not limited to the said embodiment, It is possible to implement in various aspects.

It is a perspective view of an inspection device. (Example) It is a principal part expanded sectional view of an inspection apparatus. (Example)

Explanation of symbols

10 Inspection device 12 Control unit (determination unit)
14 Light Emitting Unit 15a Laser Beam (Flux)
15b Regular reflection component 15e Internal reflection component 15s Irradiation position 16 Light-receiving part main body (light-receiving part)
16b Light receiving window 17 Light guide (light receiving part)
18 Light detector (light receiving part)

Claims (4)

A light emitting unit that irradiates the surface of a transparent object with a light beam from an oblique direction, and moves the irradiation position of the light beam in a line;
A light receiving portion extending linearly facing the irradiation position on the same side as the light emitting portion with respect to the object to be inspected, and a light receiving portion for detecting the intensity of a light beam component passing through the light receiving window;
A determination unit configured to determine pass / fail of the inspection object based on the intensity of the light flux component detected by the light receiving unit;
With
The light receiving window includes, as the light flux component, a specularly reflected light component in which the light flux is specularly reflected on the surface of the inspection object at the irradiation position, and the light beam is incident on the inspection object at the irradiation position. And after being reflected on the back surface of the object to be inspected, both of the internal reflection components emitted from the surface of the object to be inspected are simultaneously spread and formed, Inspection device.   The inspection apparatus according to claim 1, wherein a pattern is formed on the back surface of the inspection object. A first step of irradiating a surface of a transparent inspection object with a light beam from an oblique direction and moving the irradiation position of the light beam linearly;
A second step of detecting the intensity of a light beam component that passes through a light receiving window extending linearly facing the irradiation position;
A third step of determining pass / fail of the inspection object based on the intensity of the luminous flux component detected in the second step;
With
The light receiving window includes, as the light flux component, a specularly reflected light component in which the light flux is specularly reflected on the surface of the inspection object at the irradiation position, and the light beam is incident on the inspection object at the irradiation position. And after being reflected on the back surface of the object to be inspected, both of the internal reflection components emitted from the surface of the object to be inspected are simultaneously spread and formed, Inspection method.   The inspection method according to claim 3, wherein a pattern is formed on the back surface of the inspection object.

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