JP2009068985A - Surface flaw inspection device and surface flaw inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To devise a surface flaw inspection device so as to keep the detection precision of the whole of the inspection surface of an object to be inspected constant, to detect a gentle gradient flaw, not to complicate the processing of measured light receiving data, and to miniaturize the inspection device. <P>SOLUTION: The surface flaw inspection device is constituted so as to inspect the gentle gradient flaw on the surface of the object to be inspected at a high speed and equipped with an irradiation light generating means (11), a means (12) for changing the advance direction of the irradiation light generated from the irradiation light generating means, a means (13) for making the incident angle of the irradiation light on the object (14) to be inspected constant, a means (17a) for making the scanning speed of the irradiation light on the object (14) to be inspected constant, a means (15) for altering the advance direction of the reflected light from the surface of the object (14) to be inspected so as to condense the reflected light to one point, a light receiving position measuring means (16) for measuring the incident position of the reflected light, and a means (17b) for processing the measured receiving light position data to judge a flaw part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a surface defect inspection apparatus and an inspection method for inspecting a defect having a gentle gradient on the surface of an inspection object at high speed. This surface defect inspection apparatus and inspection method can be used for inspecting surface defects such as roller parts in an electrophotographic copying machine.

When a printed matter is output using an electrophotographic copying machine, it is often impossible to output a normal printed matter even if there are a few defects that are difficult to find visually on a roller member inside the machine. Therefore, it is important to detect these very small defects at the manufacturing stage.
In general, the inspection of such defects is performed by an inspector looking at the surface of the member with the eyes or touching the surface of the member. However, these defects are so small that long training was required before they could be found. Moreover, even if a defect can be found as a result of training, the burden on the inspector who performs the work is large, and there are many problems that the inspection result is influenced by the physical condition of the inspector.

In order to solve the above problems, automatic inspection methods using machines have been researched and developed. For example, in the “surface inspection apparatus” described in Japanese Patent Application Laid-Open No. 9-43163 (Patent Document 1), as shown in FIG. 4, the laser from the laser projector 42 on the inspection surface 41 of the inspection object. The beam is scanned, the reflected laser beam is incident on the light receiver 43, the incident light is converted into an electric signal by the photoelectric converter 44, and a filter (band-pass filter) 48 is applied to the electric signal. Then, the defective portion is discriminated in the specific frequency band that has passed. At this time, the pass frequency band of the filter 48 is changed according to the scanning speed of the laser beam on the surface 41 of the inspection object.
In FIG. 4, reference numeral 45 is a high voltage power source, 46 is a high voltage control circuit, 47 is a defect discriminating section, 49 is a planar defect discriminating section, and 50 is a rotary encoder.
However, in the surface inspection apparatus described in Patent Document 1, the processing is complicated, and it is difficult to keep the detection accuracy constant by changing the pass frequency band.

In another example, “surface inspection apparatus and method” described in Japanese Patent Laid-Open No. 5-332947 (Patent Document 2), laser light from a laser light source 51 is used as shown in FIG. Scanning is performed on the surface of the inspection object 57 using the polygon mirror 52, the laser beam reflected by the surface of the inspection object is received by the light receiver 55, and defect inspection is performed by image analysis.
In FIG. 5, reference numeral 53 denotes a condenser lens (fθ lens), 54 denotes a reflection mirror, 55a denotes an optical fiber, and 56 denotes a photoelectric conversion element.
However, in the surface inspection apparatus and method described in Patent Document 2, since the traveling direction of the laser light is spread by the rotating polygon mirror 52, a large light receiver 55 is necessary, and the inspection apparatus becomes large. End up. In addition, since the inclination of the laser beam applied to the surface of the inspection object 57 is not constant, the detection accuracy is not constant.

JP 9-43163 A JP-A-5-332947

  In order to solve the above-described problems of the prior art, the present invention can maintain the detection accuracy of the entire inspection surface of the inspection object constant, so that a defect having a gentle gradient can be detected, The surface defect inspection apparatus is devised so that the processing of the measured light reception data is not complicated and the inspection apparatus can be downsized.

In order to solve the above-mentioned problem, the means irradiates the surface of the inspection object with a light beam at a constant incident angle, scans the surface of the inspection object at a constant speed, and reflects on the surface of the inspection object. The reflected light is condensed at one point.
(1) A surface defect inspection apparatus according to the present invention (corresponding to claim 1) is a surface defect inspection apparatus that inspects a defect having a gentle gradient on the surface of an inspection object at a high speed,
Irradiation light generating means;
Means for changing the traveling direction of the irradiation light beam generated from the irradiation light beam generation means for each time;
Means for making the incident angle of the irradiation light beam to the inspection object constant;
Means for making the scanning speed of the irradiation light constant on the inspection object;
Means for changing the traveling direction so as to collect the reflected light beam reflected by the surface of the inspection object at one point;
A light receiving position measuring means for measuring the incident position of the reflected light beam,
Means for processing the measured light receiving position data and determining a defective portion;
It is to provide.

  By configuring in this way, the light beam reflected on the surface of the inspection object can be condensed on one point on the surface of the light receiving position measuring means. Does not require position measurement means. Further, since the surface of the inspection object can be scanned with the irradiation light having a constant incident angle and a constant scanning speed, the entire inspection surface of the inspection object can be inspected with a certain accuracy. Further, by measuring the incident position of the reflected light beam by the light receiving position measuring means, it is possible to measure the difference in inclination of the reflected light beam. Since the inspection is performed while scanning the irradiation light, the entire inspection surface of the inspection object can be efficiently inspected in a short time.

(2) In the surface defect inspection apparatus, the object to be inspected is a plate-like object, and the means for changing the traveling direction of the irradiation light beam every time is a two-degree-of-freedom rotating mirror, and the object to be inspected The means for making the incident angle of the irradiated light beam constant is a lens, and the means for making the scanning speed of the irradiated light beam constant on the inspection object is a means for commanding the angle of the two-degree-of-freedom rotating mirror. The means for changing the traveling direction of the reflected light beam may be a lens. (Corresponding to claim 2)
According to such a configuration, it can be used for defect inspection of a plate-shaped inspection object, and the surface of the inspection object can be scanned with irradiation light using a two-degree-of-freedom rotating mirror. It is possible to inspect the defect with the inspection object fixed at a certain position.

(3) In the surface defect inspection apparatus, the object to be inspected is a plate-like object, and the means for changing the traveling direction of the irradiation light beam every time is a one-degree-of-freedom rotating mirror, and the object to be inspected The means for making the incident angle of the irradiated light beam constant is a cylindrical lens, and the means for making the scanning speed of the irradiated light beam on the inspection object constant is a means for commanding the angle of the rotating mirror with one degree of freedom. In addition, the means for changing the traveling direction of the reflected light beam is a cylindrical lens, and may have means for translating the inspection object at a constant speed. (Corresponding to claim 3)
According to such a structure, since the means for moving the inspection object is provided, the inspection object can be used for defect inspection of the plate-shaped inspection object, and the inspection object can be used using a rotating mirror with one degree of freedom. It is possible to scan the surface with irradiation light.

(4) In the surface defect inspection apparatus, the object to be inspected is a cylindrical object, and the means for changing the traveling direction of the irradiation light beam every time is a one-degree-of-freedom rotating mirror, and the object to be inspected A means for making the incident angle of the irradiated light beam constant is a cylindrical lens, and a means for making the scanning speed of the irradiated light beam on the inspection object constant is a means for instructing the angle of the rotating mirror with one degree of freedom. A means for changing the traveling direction of the reflected light beam is a cylindrical lens, and a means for rotating the inspection object at a constant speed can be provided. (Corresponding to claim 4)
According to such a structure, since the means for rotating the inspection object is provided, it can be used for defect inspection of the cylindrical inspection object, and the inspection object can be inspected using a rotating mirror with one degree of freedom. It is possible to scan the surface with illumination light.

(5) A surface defect inspection method according to the present invention (corresponding to claim 5) is a surface defect inspection method for inspecting a defect having a gentle gradient on the surface of an inspection object at a high speed,
Irradiating the surface of the inspection object with a light beam at a constant angle of incidence, scanning the surface of the inspection object at a constant speed,
By means for changing the traveling direction of the reflected light beam reflected by the surface of the object to be inspected, the reflected light beam is condensed on one point on the surface of the light receiving position measuring means,
Only the light beam reflected by the defect portion on the surface of the object to be inspected is greatly deviated and incident on a position deviated from one point on the surface of the light receiving position measuring means. Is to detect the part.

  By configuring in this way, it is possible to focus the light beam reflected on the surface of the inspection object to one point on the surface of the light receiving position measuring means, so even when inspecting a wide area of the surface of the inspection object No large light receiving position measuring means is required. Further, since the surface of the inspection object can be scanned with the irradiation light having a constant incident angle and a constant scanning speed, the entire inspection surface of the inspection object can be inspected with a certain accuracy. Further, since the inspection is performed while scanning the irradiation light, the entire inspection surface of the inspection object can be efficiently inspected in a short time.

The effects of the present invention can be summarized as follows according to the claimed invention.
(1) The invention according to claim 1 and claim 5 The invention according to claim 1 and claim 5 condenses the light beam reflected by the surface of the inspection object at one point on the surface of the light receiving position measuring means, Even when inspecting a wide range of the surface of the inspection object, a large light receiving position measuring means is not required. Further, by scanning the surface of the inspection object with an irradiation beam having a constant incident angle and a constant scanning speed, the entire inspection surface of the inspection object can be inspected with a certain degree of accuracy. It is possible to detect a defect.
Further, by measuring the incident position of the reflected light beam by the light receiving position measuring means, the difference in the tilt of the reflected light beam can be measured, so that it is possible to detect a defective portion on the surface of the inspection object. Since the inspection is performed while scanning the irradiation light, the entire inspection surface of the inspection object can be efficiently inspected in a short time.

(2) Invention according to claim 2 The invention according to claim 2 can be used particularly for defect inspection of a plate-like object to be inspected, and the surface of the object to be inspected by using a two-degree-of-freedom rotating mirror. Since scanning is performed with the irradiation light beam, it is possible to inspect the defect while the inspection object is fixed at a certain position, and the structure can be made smaller. Moreover, since it can manufacture using a general purpose product, manufacturing cost can be restrained low.

(3) Invention according to claim 3 The invention according to claim 3 is provided with a means for moving the inspection object in translation, and thus can be used particularly for defect inspection of a plate-shaped inspection object. . Further, the surface of the object to be inspected can be scanned with the irradiation light beam using a rotating mirror with one degree of freedom, and the surroundings of the means for changing the traveling direction of the irradiation light beam with time can be realized with a simple device configuration. Is possible. Furthermore, since it can manufacture using a general purpose product, manufacturing cost can be restrained low.

(4) Invention According to Claim 4 Since the invention according to claim 4 includes means for rotating the object to be inspected, it can be used particularly for defect inspection of a cylindrical object to be inspected. Further, the surface of the object to be inspected can be scanned with the irradiation light beam using a rotating mirror with one degree of freedom, and the surroundings of the means for changing the traveling direction of the irradiation light beam with time can be realized with a simple device configuration. Is possible. Furthermore, since it can manufacture using a general purpose product, manufacturing cost can be restrained low.

  Embodiments 1 to 3 of the surface defect inspection apparatus and inspection method according to the present invention will be described below with reference to FIGS.

First, Example 1 (corresponding to claims 1, 2, and 5) will be described with reference to FIG.
In the first embodiment, a laser light source (irradiation light beam generation means) 11, a two-degree-of-freedom rotating mirror 12 (means for changing the traveling direction of the irradiation light beam with time), and a lens (irradiation light to the object to be inspected). The laser beam L1 parallel to the traveling direction is generated using the means 13 for making the incident angle constant, and scanning is performed while irradiating the surface of the fixed plate-like inspection object 14 with the laser beam. The reflected laser beam L2 is condensed on one point on the surface of a light receiving element (light receiving position measuring means) 16 such as a PSD sensor (semiconductor position detecting element) by a lens (means for changing the traveling direction of the reflected light beam) 15, and the value is measured. is doing.

In the surface defect inspection apparatus shown in FIG. 1, when the laser beam L1 irradiated on the surface of the inspection object 14 hits the defect and changes the traveling direction, the surface of the light receiving element 16 changes from one point (condensing point). In order to enter the shifted position, the computer (means for processing the measured light receiving position data and determining the defective portion) 17b is used to automatically determine whether the reflected laser light is in the defective portion or the normal portion. Can be done automatically. At this time, the angle of the two-degree-of-freedom rotating mirror 12 is controlled using a computer (means for instructing the angle of the rotating mirror) 17a so that the scanning speed of the laser light on the surface of the inspection object 14 is constant. It is trying to become.
As a result, the detection accuracy becomes constant within the inspection range of the surface of the inspection object 14, and processing is facilitated even when a filter is applied to remove noise in the measurement data.

Next, Example 2 (corresponding to claims 1, 3, and 5) will be described with reference to FIG.
In the second embodiment, a laser light source (irradiation light beam generation means) 21, a rotating mirror with one degree of freedom (means for changing the traveling direction of the irradiation light beam for each time) 22, and a cylindrical lens (light irradiation light on the object to be inspected). The laser beam L1 parallel to the traveling direction is generated by using a means 23 for making the incident angle of the laser beam constant, and the laser beam L1 is translated by a moving stage (means for moving the object to be translated at a constant speed) 28. Scanning is performed while irradiating the surface of the plate-like inspection object 24, and the reflected laser light L2 at that time is received by a cylindrical lens (means for changing the traveling direction of the reflected light) 25 and a light receiving element (light receiving position) such as a PSD sensor. Measuring means) The light is condensed at one point on the surface of 26, and the value is measured.

In the surface defect inspection apparatus shown in FIG. 2, when the laser beam L1 irradiated on the surface of the inspection object 24 hits a defect and changes its traveling direction, the surface of the light receiving element 26 shifts from one point (condensing point). Therefore, the computer (means for processing the measured light receiving position data and determining the defective portion) 27b is used to automatically determine whether the reflected laser light is in the defective portion or the reflected laser light in the normal portion. Can be done. At this time, the angle of the rotating mirror 22 with one degree of freedom is controlled using a computer (means for instructing the angle of the rotating mirror) 27a, and the scanning speed of the laser light L1 on the surface of the inspection object 24 is constant. It is trying to become.
As a result, the detection accuracy is constant within the inspection range of the surface of the inspection object 24, and the processing is facilitated even when a filter is applied to remove noise in the measurement data.

Next, a third embodiment (corresponding to claims 1, 4 and 5) will be described with reference to FIG.
In this third embodiment, a laser light source (irradiation light beam generation means) 31, a rotating mirror with one degree of freedom (means for changing the traveling direction of the irradiation light beam with time) 32, and a cylindrical lens (light irradiation light on the object to be inspected). The laser beam L1 parallel to the advancing direction is generated using the 33), and the laser beam L1 is rotated by the rotating jig (the means for rotating the inspection object at a constant speed) 38. Scanning is performed while irradiating the surface of the cylindrical inspection object 34, and the reflected laser light L2 at that time is received by a cylindrical lens (means for changing the traveling direction of the reflected light) 35 and a light receiving element (light receiving device) such as a PSD sensor. The light is condensed on one point on the surface of the position measuring means) 36 and the value is measured.

In the surface defect inspection apparatus shown in FIG. 3, when the laser beam L1 irradiated on the surface of the cylindrical inspection object 34 hits the defect and changes its traveling direction, a point on the surface of the light receiving element 36 (condensing point). ), The computer (means for processing the measured light receiving position data and determining the defective portion) 37b is used to determine whether the reflected laser light is in the defective portion or the normal portion. Can be done automatically. At this time, the angle of the rotating mirror 32 with one degree of freedom is controlled using a computer (means for instructing the angle of the rotating mirror) 37a, and the scanning speed of the laser light L1 on the surface of the inspection object 34 is constant. It is trying to become.
As a result, the detection accuracy becomes constant within the inspection range of the surface of the inspection object 34, and the processing is facilitated even when a filter is applied to remove noise in the measurement data.

These are the schematic diagrams about Example 1 of this invention which scans a fixed plate-shaped to-be-inspected object, irradiating a laser beam, and measures the reflected laser beam with a sensor. These are the schematic diagrams about Example 2 of this invention which scans the plate-shaped to-be-inspected object which is moving in translation, irradiating a laser beam, and measures the reflected laser beam with a sensor. These are the schematic diagrams about Example 3 of this invention which scans the cylindrical to-be-inspected object which is rotating, irradiating a laser beam, and measures the reflected laser beam with a sensor. These are the schematic diagrams explaining the conventional surface inspection apparatus. These are the schematic diagrams explaining another conventional surface inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Laser light source 12 ... Two-degree-of-freedom rotary mirror 13, 15 ... Lens 14 ... Plate-shaped inspection object 16 ... Light receiving element (PSD sensor) 17a, 17b ... Computer 21 ... Laser light source 22 ... One-degree-of-freedom rotary mirror DESCRIPTION OF SYMBOLS 23,25 ... Cylindrical lens 24 ... Plate-shaped to-be-inspected object 26 ... Light receiving element (PSD sensor) 27a, 27b ... Computer 28 ... Moving stage 31 ... Laser light source 32 ... One degree of freedom rotating mirror 33, 35 ... Cylindrical lens 34 ... Cylindrical object 36 ... Light receiving element (PSD sensor) 37a, 37b ... Computer 38 ... Rotating jig

Claims (5)

A surface defect inspection apparatus for inspecting a defect having a gentle gradient on the surface of an inspection object at high speed,
Irradiation light generating means;
Means for changing the traveling direction of the irradiation light beam generated from the irradiation light beam generation means for each time;
Means for making the incident angle of the light beam incident on the inspection object constant;
Means for making the scanning speed of the irradiation light constant on the inspection object;
Means for changing the traveling direction so that the reflected light beam reflected by the surface of the inspection object is collected at one point;
A light receiving position measuring means for measuring the incident position of the reflected light beam,
Means for processing the measured light receiving position data and determining a defective portion;
A surface defect inspection apparatus comprising:   The inspection object is a plate-like object, the means for changing the traveling direction of the irradiation light beam every time is a two-degree-of-freedom rotating mirror, and the incident angle of the irradiation light beam to the inspection object is constant. Is a lens, the means for making the scanning speed of the irradiated light on the inspection object constant is the means for instructing the angle of the rotating mirror with two degrees of freedom, and the means for changing the traveling direction of the reflected light The surface defect inspection apparatus according to claim 1, wherein the surface defect inspection apparatus is a lens.   The inspection object is a plate-like object, the means for changing the traveling direction of the irradiation light beam every time is a rotating mirror with one degree of freedom, and the incident angle of the irradiation light beam to the inspection object is constant. Is a cylindrical lens, and means for making the scanning speed of the irradiated light beam constant on the object to be inspected is means for commanding the angle of the rotating mirror with one degree of freedom, and means for changing the traveling direction of the reflected light beam The surface defect inspection apparatus according to claim 1, wherein is a cylindrical lens, and has means for translating the inspection object at a constant speed.   The inspection object is a cylindrical object, the means for changing the traveling direction of the irradiation light beam every time is a one-degree-of-freedom rotating mirror, and the incident angle of the irradiation light beam to the inspection object is constant. Is a cylindrical lens, and means for making the scanning speed of the irradiation light beam constant on the inspection object is means for commanding the angle of the rotating mirror with one degree of freedom, and means for changing the traveling direction of the reflected light beam The surface defect inspection apparatus according to claim 1, wherein is a cylindrical lens, and has means for rotating the inspection object at a constant speed. A surface defect inspection method for inspecting a defect having a gentle gradient on the surface of an inspection object at high speed,
Irradiating the surface of the inspection object with a light beam at a constant angle of incidence, scanning the surface of the inspection object at a constant speed,
By means for changing the traveling direction of the reflected light beam reflected by the surface of the object to be inspected, the reflected light beam is condensed on one point on the surface of the light receiving position measuring means,
Only the light beam reflected by the defect portion on the surface of the object to be inspected is greatly deviated and incident on a position deviated from one point on the surface of the light receiving position measuring means. A surface defect inspection method characterized by detecting a portion.

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