JP5367292B2 - Surface inspection apparatus and surface inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface inspection apparatus and a surface inspection method, capable of detecting defects in the wide range of the surface of a material to be inspected. <P>SOLUTION: The surface inspection apparatus 10 includes: a light projecting part 11 for irradiating a light; a light condensing optical part 12 for irradiating a detection light 31 toward the surface 2 of the material to be measured 1, by converting the light to a rectangular shape having the first side and a second side and enlarging the first side part a and scaling down the second side part b, to form the line shaped detection light 31; a detection part 13 for forming the detection light 31 reflected from the surface 2 of the material to be measured as a line-shaped receiving light image 40; and an image processing part 14 for determining the deformed part 49 of the line-shaped receiving light 40, received by the detection part 13 to be the defect 50 of the surface 2 of the material to be measured 1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a surface inspection apparatus and a surface inspection method, and more particularly to a surface inspection apparatus and a surface inspection method for inspecting a surface defect of an object to be inspected.

As an inspection object, for example, the surface of a rotating drum is inspected for defects on the surface of the drum by irradiating the surface of the drum with light, capturing the reflected light with a camera, and performing image processing. (See Patent Document 1).
JP 2006-208184 A

However, in the defect inspection method disclosed in Patent Document 1, when inspecting an uneven defect having a size of about 1 μm on the surface, even if a camera with 10 million pixels is used, for example, Defects can only be detected within a rectangular inspection range of up to 3 mm × 3 mm. In reality, when the influence of noise or the like is taken into consideration at the time of inspection, the range in which the surface irregularities can be inspected becomes even narrower.
Accordingly, an object of the present invention is to provide a surface inspection apparatus and a surface inspection method capable of detecting defects on the surface of an object to be inspected over a wide range in order to solve the above problems.

In order to solve the above problem, the surface inspection apparatus according to the first aspect of the present invention is a surface inspection apparatus for inspecting the surface of a measurement object,
A light projecting unit that emits light;
The light is changed to a rectangular light having a first side and a second side, the first side is enlarged, and the second side is reduced to form a linear detection light. A condensing optical unit for irradiating detection light toward the surface of the object to be measured;
A detection unit for forming the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape;
An image processing unit having a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measurement object;
With
The detection unit includes a screen that forms the light reception image formed in the linear shape, and a camera that captures the light reception image formed in the linear shape received by the screen as an image,
The length of the second side part of the detection light having a rectangular shape is sequentially reduced from the condensing optical part through the surface of the measured object until it reaches the screen,
The detection light reflected from the surface of the object to be measured is directly irradiated onto the screen.
The surface inspection apparatus according to a second aspect of the present invention is the surface inspection apparatus according to the first aspect of the present invention , wherein the subject is within the condensing optical unit having a plurality of condensing means comprising lenses or lens mechanisms. The second side portion of the detection light before entering the condensing means closest to the measurement body is b, and the detection light irradiated to the irradiation target portion on the surface of the measurement object is b. When the second side is b1, and the second side of the received light image formed on the screen is b2,
The relationship of length of b> length of b1> length of b2 is satisfied.
The surface inspection apparatus according to the third aspect of the present invention is the surface inspection apparatus according to the first or second aspect of the present invention, wherein the length of the first side portion of the detection light having the rectangular shape is It increases sequentially from the condensing optical part through the surface of the object to be measured until it reaches the screen.
The surface inspection apparatus according to a fourth aspect of the present invention is the surface inspection apparatus according to the third aspect of the present invention , wherein the subject is within the condensing optical unit having a plurality of condensing means comprising a lens or a lens mechanism. The first side portion of the detection light before entering the light condensing means closest to the measurement body is defined as a, and the detection light irradiated to the irradiation target site on the surface of the measurement target When the first side is a1, and the first side of the received light image formed on the screen is a2,
The relationship of length of a2> length of a1> length of a is satisfied.
A surface inspection apparatus according to a fifth aspect of the present invention is the surface inspection apparatus according to any one of the first to fourth aspects of the present invention, wherein the image processing unit is formed in the linear shape captured by the camera. The edge position data is obtained from the linear data of the received light image, and the defect on the surface of the object to be measured is determined by the amount that the edge position data is deviated from the approximate curve obtained from the edge position data. It is characterized by determining.

A surface inspection apparatus according to a sixth aspect of the present invention is a surface inspection apparatus that inspects the surface of a measurement object,
A light projecting unit that emits light;
The light is changed to a rectangular light having a first side and a second side, the first side is enlarged, and the second side is reduced to form a linear detection light. A condensing optical unit for irradiating detection light toward the surface of the object to be measured;
A detection unit for forming the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape;
An image processing unit having a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measurement object;
With
The image processing unit acquires data of a plurality of edge positions on both sides of the linear shape from linear data of the light reception image formed in the linear shape, and the acquired plurality of edges for each one side of the linear shape A linear approximate line is calculated from the position data, the distance between the edge position data and the linear approximate line is calculated for each edge position data, and the calculated values on both sides of the calculated linear line are calculated. The defect on the surface of the object to be measured is determined based on a total value obtained by summing all the values of the distances to the data of a plurality of edge positions.
The surface inspection apparatus according to a seventh aspect of the present invention is the surface inspection apparatus according to the sixth aspect of the present invention, wherein the detection unit forms a screen on which the linearly received light image is formed, and the screen And a camera that captures, as an image, a light-receiving image formed in a linear shape that is received by the camera.
The surface inspection apparatus according to an eighth aspect of the present invention is the surface inspection apparatus according to the sixth aspect of the present invention, wherein the detection unit is a camera that captures the linearly formed light reception image as an image. Features.

The surface inspection apparatus according to a ninth aspect of the present invention is the surface inspection apparatus according to any one of the first to eighth aspects of the present invention, wherein the surface of the object to be measured is a flat surface.
The surface inspection apparatus according to a tenth aspect of the present invention is the surface inspection apparatus according to any one of the first to eighth aspects of the present invention, wherein the surface of the object to be measured is a cylindrical curved surface, The optical optical unit irradiates the detection light such that the longitudinal direction of the cylindrical curved surface and the second side are parallel or oblique.
A surface inspection apparatus according to an eleventh aspect of the present invention is the surface inspection apparatus according to any one of the first to tenth aspects of the present invention, wherein the object to be measured is held and the light collecting optical system is It has the stage for moving the position of a to-be-measured body, It is characterized by the above-mentioned.

The surface inspection method according to the first aspect of the present invention is a surface inspection method for inspecting the surface of a measurement object,
The light projecting portion irradiates light having a rectangular shape with a cross section having a first side and a second side,
A condensing optical unit enlarges the first side of the light of the light projecting unit and reduces the second side to form linear detection light, and the detection light is measured. Irradiate towards the surface of the body,
A detection unit having a screen and a camera forms an image of the detection light reflected from the surface of the object to be measured as a linearly received light image by the screen, and is received by the screen by the camera. Capture the light-receiving image formed in the linear form as an image,
The length of the second side part of the detection light having a rectangular shape is sequentially reduced from the condensing optical part through the surface of the measured object until it reaches the screen,
The detection light reflected from the surface of the object to be measured is directly applied to the screen,
The image processing unit is characterized in that a deformed portion of the light reception image formed in the linear shape received by the detection unit is defined as a defect on the surface of the measured object.
A surface inspection method according to a second aspect of the present invention is the surface inspection method according to the first aspect of the present invention , wherein the subject is within the condensing optical unit having a plurality of condensing means comprising lenses or lens mechanisms. The second side portion of the detection light before entering the condensing means closest to the measurement body is b, and the detection light irradiated to the irradiation target portion on the surface of the measurement object is b. When the second side is b1, and the second side of the received light image formed on the screen is b2,
The relationship of length of b> length of b1> length of b2 is satisfied.
The surface inspection method according to a third aspect of the present invention is the surface inspection method according to the first or second aspect of the present invention, wherein the length of the first side portion of the detection light having the rectangular shape is It increases sequentially from the condensing optical part through the surface of the object to be measured until it reaches the screen.
A surface inspection method according to a fourth aspect of the present invention is the surface inspection method according to the third aspect of the present invention , wherein the subject is within the condensing optical unit having a plurality of condensing means comprising a lens or a lens mechanism. The first side portion of the detection light before entering the light condensing means closest to the measurement body is defined as a, and the detection light irradiated to the irradiation target site on the surface of the measurement target When the first side is a1, and the first side of the received light image formed on the screen is a2,
The relationship of length of a2> length of a1> length of a is satisfied.
A surface inspection method according to a fifth aspect of the present invention is a surface inspection method for inspecting the surface of a measurement object,
The light projecting portion irradiates light having a rectangular shape with a cross section having a first side and a second side,
A condensing optical unit enlarges the first side of the light of the light projecting unit and reduces the second side to form linear detection light, and the detection light is measured. Irradiate towards the surface of the body,
The detection unit forms an image of the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape,
The image processing unit has a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measured object,
The defect on the surface of the object to be measured is obtained by acquiring data of a plurality of edge positions on both sides of the linear shape from the linear data of the light reception image formed in the linear shape. A linear approximate line is calculated from the acquired data of the plurality of edge positions, a distance between the edge position data and the linear approximate line is calculated for each of the edge position data, and then further, The determination is made based on a total value obtained by summing all the distance values for the calculated data of the plurality of edge positions on both sides of the linear shape.

  According to the present invention, the first side of the light is enlarged and the second side of the light is reduced to form linear detection light, and the detection light is irradiated toward the surface of the object to be measured. Since the detection light reflected from the surface of the object to be measured is formed as a light-receiving image formed in a linear shape, and the deformed portion of the light-receiving image formed in this line is regarded as a defect on the surface of the object to be measured, A defect on the surface of the object to be inspected can be detected.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a perspective view showing a first preferred embodiment of the surface inspection apparatus of the present invention.
A surface inspection apparatus 10 shown in FIG. 1 is used to inspect defects such as irregularities on the surface 2 of the measurement object 1. In the first embodiment shown in FIG. 1, the surface 2 of the measurement object 1 is a flat surface.
The surface inspection apparatus 10 includes a light projecting unit 11, a condensing optical unit 12, a detection unit 13, and an image processing unit 14.

The light projecting unit 11 illustrated in FIG. 1 is a laser light source such as a He—Ne laser, for example, and the light projecting unit 11 irradiates the condensing optical unit 12 with a laser beam 20 having a circular cross section.
The condensing optical unit 12 illustrated in FIG. 1 is disposed between the light projecting unit 11 and the surface 2 of the measurement target 1 and includes a first lens 21 and a second lens 22. The first lens 21 is disposed on the light projecting unit 11 side, and the second lens 22 is disposed on the surface 2 side of the measurement object 1. The optical axis OP <b> 1 of the light projecting unit 11 and the condensing optical system 12 is inclined by an angle M with respect to the surface 2 of the measured object 1.

FIG. 2 shows light 20B and the like in the surface inspection apparatus 10 shown in FIG.
The first lens 21 shown in FIG. 1 forms laser light 20 having a circular cross section into light 20B having a rectangular cross section. As shown in FIG. 2, the light 20 </ b> B having a rectangular cross section has first side parts a and a second side parts b and b facing each other. Further, the first lens 21 enlarges the length of the first sides a and a of the light 20B having a rectangular cross section, and the second lens 22 has the second sides b and b of the light 20B having a rectangular cross section. Reduce the length. The two opposing first side parts a and a and the two opposing second side parts b and b are orthogonal to each other, and the length of the first side part a is larger than the length of the second side part b.

As shown in FIG. 2, the lengths of the first sides a and a of the light 20B having a rectangular cross section are enlarged, and the lengths of the second sides b and b of the light 20B having a rectangular cross section are reduced. The detection light 31 having a shape is irradiated on the irradiation target portion 30 on the surface 2 of the measurement object 1.
Thereby, as shown in FIGS. 1 and 2, the detection light 31 having a rectangular shape that is elongated compared to the light 20 </ b> B having a rectangular cross section is irradiated from the condensing optical system 12 to the irradiation target portion 30 on the surface 2 of the measurement object 1. Can be irradiated. The elongate rectangular detection light 31 has first opposing side portions a1 and a1 and second opposing side portions b1 and b1.

  Thus, as shown in FIG. 2, the first lens 21 widens the first sides a and a of the laser beam 20 to a wide angle, and the second lens 22 has the second sides b and b of the laser beam 20. By narrowing down and reducing, the irradiation target portion 30 on the surface 2 of the measurement object 1 can be irradiated with a more elongated rectangular detection light 31.

Returning to FIG. 1, the detection unit 13 includes a screen 33 and a camera 34. As shown in FIGS. 1 and 2, the screen 33 can form the detection light 31 reflected from the irradiation target portion 30 on the surface 2 of the measurement object 1 as a light receiving image 40 formed in a linear shape. .
That is, the detection light 31 is further elongated and projected on the screen 33. As shown in FIG. 2, the light reception image 40 formed in a linear shape has opposed first side portions a <b> 2 and a <b> 2 and opposed second side portions b <b> 2 and b <b> 2.

Here, as shown in FIG. 2, the relationship of the length of the first side part a <b>2> the length of the first side part a <b>1> the length of the first side part a, and the length of the second side part b> The length of the second side part b1 is greater than the length of the second side part b2.
For example, a CCD (Charge Coupled Device) camera can be used as the camera 34, and the camera 34 takes a light-receiving image 40 formed in a line shape on the screen 33 and converts it into an electric signal.

In the irradiation target portion 30 on the surface 2 of the measurement object 1 shown in FIG. 1, an example is shown in which uneven defects are not formed, and the light reception image 40 formed in a linear shape is linear and linear. The formed received light image 40 has no deformed portion.
On the other hand, FIG. 3 shows an example in which a concave defect 50 is formed in the irradiation target portion 30 of the surface 2 of the measurement object 1.

  The image processing unit 14 includes an image processing device 35 and a monitor 36. As shown in FIG. 3, the image processing apparatus 35 converts a deformed portion 49 of the light reception image 40 formed by the CCD camera 34 into a linear shape to a surface defect 50 in the irradiation target portion 30 of the surface 2 of the measurement object 1. Process as. The monitor 36 displays to the operator a light reception image 40 formed in a line and a deformed portion 49 of the light reception image 40 formed in a line.

  As shown in FIG. 3, when the defect 50 exists in the irradiation target portion 30, a deformed portion 49 is formed in the light receiving image 40 formed in a linear shape corresponding to the defect 50. As described above, when the irradiation target site 30 has the defect 50, the deformed portion 49 corresponding to the defect 50 is enlarged and projected out of the light-receiving image 40 formed in a linear form. The light receiving image 40 formed in a linear shape including 49 is optically captured.

The image processing device 35 processes the deformed portion 49 of the linearly received light image 40 captured by the CCD camera 34 on the assumption that the surface defect 50 in the irradiation target portion 30 of the surface 2 of the measured object 1 exists. The monitor 36 can display the light reception image 40 formed in a line and the deformed portion 49 of the light reception image 40 formed in a line to the operator.
As described above, the surface inspection apparatus 10 according to the first embodiment of the present invention expands the first side of the light and reduces the second side of the light to form linear detection light, thereby detecting light. Is irradiated toward the surface of the object to be measured, and the detection light reflected from the surface of the object to be measured is formed as a light-receiving image formed in a linear shape, and a deformed portion of the light-receiving image formed in this linear shape is measured. Since the defect is on the surface of the body, the defect 49 on the surface 2 of the inspection object 1 can be detected with high accuracy and in a wide range.

(Second Embodiment)
FIG. 4 is a perspective view showing a second preferred embodiment of the surface inspection apparatus of the present invention.
The surface inspection apparatus 10B according to the second preferred embodiment of the present invention shown in FIG. 4 is different from the surface inspection apparatus 10 of the first embodiment shown in FIGS. 1 to 3 in the configuration of the detection unit 13B. Unlike the detection unit 13 shown in FIG. 1 that includes a screen 33 and a camera 34, the detection unit 13B includes only a camera 34B without using a screen. Accordingly, the camera 34 can directly capture the detection light 31 reflected from the irradiation target portion 30 on the surface 2 of the measurement object 1 as a linearly received light image 40. The detection light 31 can be enlarged and projected as a light receiving image 40 that is further elongated and formed linearly in the camera 34.
The other components of the surface inspection apparatus 10B shown in FIG. 4 are substantially the same as the corresponding components of the surface inspection apparatus 10 shown in FIG.

(Third embodiment)
FIG. 5 is a view showing a third preferred embodiment of the surface inspection apparatus of the present invention. FIG. 6 is a plan view of the surface inspection apparatus 10C of FIG. 5 as viewed from the S direction.
The surface inspection apparatus 10 </ b> C shown in FIGS. 5 and 6 is used to inspect the concave defect 150 on the surface 102 of the columnar or cylindrical measurement object 100, unlike the previous embodiments. Accordingly, the surface 102 of the measured object 100 is a curved surface, and the measured object 100 is a rotating drum used in a copying machine, for example.

  The surface inspection apparatus 10C includes a light projecting unit 111, a condensing optical unit 112, a detecting unit 113, and an image processing unit 114. The optical axes of the light projecting unit 111 and the condensing optical unit 112 are along the X direction, the axial direction L of the measured object 100 is the Z direction, and the screen 133 is in the Y direction with respect to the measured object 100. It is arranged along the interval. The screen 133 is a plane parallel to the XZ plane. The X, Y, and Z directions are orthogonal to each other.

The light projecting unit 111 illustrated in FIG. 5 is a laser light source such as a He—Ne laser, for example, and the light projecting unit 11 irradiates the condensing optical unit 112 with a laser beam 120 having a circular cross section.
The condensing optical unit 112 illustrated in FIG. 5 is disposed between the light projecting unit 111 and the surface 102 of the measurement target 100, and includes a first lens mechanism 121 and a second lens mechanism 122. The first lens mechanism 121 is disposed on the light projecting unit 111 side, and the second lens mechanism 122 is disposed on the surface 102 side of the measurement object 100.

  The first lens mechanism 121 squeezes the laser light 120 having a circular cross section into light 120B having a rectangular cross section. The light 120B having a rectangular cross section has first side portions a and a that face each other and second side portions b and b that face each other. Moreover, the second lens mechanism 121 enlarges the length of the first sides a and a of the light 20B having a rectangular cross section. Then, the second lens mechanism 122 reduces the length of the second sides b and b of the light 120B having a rectangular cross section. The two opposing first side parts a and a and the two opposing second side parts b and b are orthogonal to each other, and the length of the first side part a is larger than the length of the second side part b.

  FIG. 8 shows an example of a surface defect 150 in the irradiation target portion 130 of the surface 102 of the measurement object 100, and the defect 150 in this example is a recess. When the detection light 131 is irradiated onto the irradiation target part 130 including the defect 150, the detection light 131 is reflected by the irradiation target part 130 and is enlarged and projected as a light reception image 140 formed linearly on the screen 133. As a result, as shown in FIGS. 5 and 8, a light receiving image 140 formed in a more elongated line shape can be formed on the screen 133.

As shown in FIG. 5, the detection unit 113 includes a screen 133 and a camera 134. As shown in FIGS. 1 and 2, the screen 133 can form a detection light 131 reflected on the irradiation target portion 130 of the surface 102 of the measurement object 100 as a light reception image 140 formed in a linear shape. The detection light 131 is further elongated and projected on the screen 133.
For example, a CCD (Charge Coupled Device) camera can be used as the camera 134, and the camera 134 takes a light reception image 140 formed in a line shape on the screen 133 and converts it into an electric signal.

  The image processing unit 114 includes an image processing device 135 and a monitor 136. The image processing device 135 processes the deformed portion 1149 of the linearly received light image 140 captured by the CCD camera 134 as a surface defect 150 in the irradiation target portion 130 of the surface 102 of the measurement object 100. The monitor 136 displays a light reception image 140 formed in a linear shape and a deformed portion 149 of the light reception image 140 formed in a linear shape.

  As shown in FIG. 5, the DUT 100 is detachably mounted on the rotary stage 160 of the XYZθ stage 155. The rotary stage 160 can position the object to be measured 100 by rotating along the rotation direction F about the central axis L.

The XYZθ stage 155 can be positioned by linearly moving the rotary stage 160 along the X, Y, and Z directions, and can be positioned by rotating in the θ direction. As a result, the XYZθ stage 155 and the rotary stage 160 allow the XYZθ stage 155 and the rotary stage 160 to minimize the thickness of the light reception image 140 formed in a line on the screen 133, for example. The distance to the system 112 can be adjusted with respect to the X, Y, and Z directions.
As a result, signal fluctuations due to disturbances such as rotational eccentricity of the measured object can be suppressed, and stable defect detection is possible.

  FIG. 7 shows an example in which the detection light 131 is irradiated with an inclination of θ1 with respect to the axis L of the measurement object 100. When the laser beam source is circular, only the first lens mechanism and the first lens mechanism increase the number of lenses and enlarge the mechanism of the condensing optical system 112 in order to enlarge and irradiate side a. In that case, even if the a side is parallel light, the reflected light from the measurement object 131 of the detection light 131 can be expanded by irradiating the curved surface of the measurement object with inclination.

When it is desired to avoid an increase in the lens mechanism in the cylindrical measurement object, the detection light 131 is compared with the irradiation target portion 130 of the surface 102 of the measurement object 100 that is a curved surface. By irradiating obliquely with respect to the axial direction L of 100, the final screen 133 can be enlarged as if the condensing optical system has an a-side enlargement function.
In addition, if the magnification effect by oblique irradiation and the magnification by the lens are combined, the image is further magnified, and even when the unevenness is in a wide range in the axial direction, the distortion of the linear light receiving image 140 becomes clearer and the defect detection of the wide unevenness Is possible.

The enlarged light-receiving image 140 formed into a line has a deformed portion 149 corresponding to the defect 150, and the deformed portion 149 is orthogonal to the longitudinal direction of the light-receiving image 140 formed in a line. Protrudes in the direction.
An image processing apparatus 135 shown in FIG. 5 processes a deformed portion 149 of the light reception image 140 formed in a linear shape captured by the CCD camera 134 as a surface defect 150 in the irradiation target portion 130 of the surface 102 of the measurement object 100. . The monitor 136 displays a light reception image 140 formed in a linear shape and a deformed portion 149 of the light reception image 140 formed in a linear shape.

(Fourth embodiment)
FIG. 9 is a view showing a fourth preferred embodiment of the surface inspection apparatus of the present invention.
The surface inspection apparatus 10D according to the fourth preferred embodiment of the present invention shown in FIG. 9 is different from the surface inspection apparatus 10C of the third embodiment shown in FIG. Unlike the detection unit 113 shown in FIG. 5 that includes a screen 133 and a camera 134, the detection unit 13D includes only a camera 134D without using a screen. Therefore, the camera 134D can directly capture the detection light 131 reflected from the irradiation target portion 130 of the surface 102 of the measurement object 100 as a light reception image 140 formed in a linear shape. The detection light 131 can be enlarged and projected as a light receiving image 140 that is further elongated and formed linearly in the camera 134.
The other components of the surface inspection apparatus 10D shown in FIG. 9 are substantially the same as the corresponding components of the surface inspection apparatus 10C shown in FIG.

  Next, referring to FIG. 10, the image processing apparatus 35 according to the above-described embodiment forms a deformed portion 49 of the light reception image 40 formed in a linear shape on the surface of the irradiation target portion 30 of the surface 2 of the measurement object 1. An example of a processing method for processing as the defect 50 will be described. In this processing method, the image processing apparatus 135 according to the above-described embodiment processes the deformed portion 149 of the light reception image 140 formed in a linear shape as a surface defect 150 in the irradiation target portion 130 of the surface 102 of the measurement object 100. The same applies to the case.

  FIG. 10A shows a deformed portion 49 of the light-receiving image 40 formed in a linear shape. The deformed portion 49 is opposite to the edge position data DAn (DA1 to DA7) in the window W on the screen. Side edge position data DBn (DB1 to DB8) is obtained.

  Next, as shown in FIG. 10B, an approximate curve TA is drawn for the edge position data DAn (DA1 to DA7), and an approximate curve TB is drawn for the opposite edge position data DBn (DB1 to DB8). Draw.

  Next, in FIG. 10C, the total value of the distance An (absolute value) between each edge position data DAn (DA1 to DA7) and the approximate curve TAn, and each edge position data DBn (DB1 to DB8) The total value of the distance Bn (absolute value) with the approximate curve TBn is calculated. Then, the determination value V is obtained by summing the total value of the distance An and the total value of the distance Bn. If the determination value V is greater than or equal to a predetermined value, it is determined that the deformed portion 49 is defective. The determination of the deformation portion 149 can be performed in the same manner as the determination of the deformation portion 49.

  In this way, the image processing unit apparatus obtains edge data from the linear data of the linearly received light image captured by the camera, and the edge data is an approximation of the linearly received light image. Defects on the surface of the object to be measured are determined based on the amount deviated from the curve (total distance).

FIG. 11 shows the relationship between the measured dent depth and the image processing data in the irradiation target portion 130 of the surface 102 of the measurement object 100 that is a drum in the third embodiment shown in FIG.
Comparing the case where the drum has no dent and is a good product and the dent portion with the dent, it can be seen that the area V formed by the approximate curve and the edge position is larger at the dent portion with the dent.

  In addition, it can be seen that the area V is increased as the size of the dent increases. Therefore, if the criterion for determining the area V is set to about 1500 and the determination is made that the defective product is defective, it is possible to determine a defective product having a dent value of 1 μm or more.

In the present invention, the surface inspection apparatus that inspects the surface of the object to be measured includes a light projecting unit that irradiates light, and the first side by changing the light into a rectangular light having a first side and a second side. A condensing optical unit for enlarging the portion and reducing the second side portion to form linear detection light and irradiating the detection light toward the surface of the measured object, and reflecting from the surface of the measured object An image in which a detection portion for forming the detected light as a linearly received light image and a deformed portion of the linearly received light image received by the detection portion as a defect on the surface of the object to be measured A processing unit.
As a result, the first side portion of the light is enlarged and the second side portion of the light is reduced to form a linear detection light, and the detection light is irradiated toward the surface of the measurement object to be measured. The detection light reflected from the surface of the body is formed as a light-receiving image formed in a linear shape, and the deformed portion of the light-receiving image formed in a linear shape is used as a defect on the surface of the object to be measured. Surface defects can be detected.

When the surface of the object to be measured is flat, defects on the surface of the object to be inspected can be detected over a wide range.
When the surface of the object to be measured is a cylindrical curved surface, the condensing optical unit irradiates the detection light parallel or obliquely to the longitudinal direction of the cylinder, so that the detection light is a curved surface of the object to be measured. It can be reflected and enlarged and projected at the detection unit.

  The detection unit has a screen that forms a linearly received light image and a camera that captures the linearly received light image received by the screen as an image. Can project.

  The image processing unit obtains edge position data from the linear data of the light-receiving image formed in a line captured by the camera, and the edge position data is deviated from the approximate curve obtained from the edge position data. Since the defect on the surface of the object to be measured is determined, the defect can be determined accurately.

  In addition, a stage for holding the measured object and moving the position of the measured object relative to the condensing optical system is provided. Thereby, when the condensing optical part irradiates the light for detection with respect to the surface of a to-be-inspected object, the length of the 1st edge part of a detection light and the length of a 2nd edge part can be adjusted.

  By using the surface inspection apparatus and the surface inspection method of the present invention, it is possible to detect uneven defects in a wide range and with high accuracy. That is, defects such as unevenness on the surface of the detection range corresponding to the width of the light of the light projecting unit, for example, the laser beam can be enlarged and projected on the detection unit, and a defect of about 1 μm, for example, can be detected in a wide range.

By the way, this invention is not limited to the said embodiment, A various modified example is employable.
For example, the light projecting unit may use, for example, a light emitting diode or another type of light source in addition to the laser light source.

1 is a perspective view showing a first preferred embodiment of a surface inspection apparatus of the present invention. The first sides a and a of the light having a rectangular cross section are enlarged, the second sides b and b of the light having a rectangular cross section are reduced, and the long rectangular detection light is irradiated on the surface of the object to be measured. It is a figure which shows a mode that the target site | part is irradiated. It is a figure which shows the example in case a defect exists in the irradiation object site | part. It is a perspective view which shows preferable 2nd Embodiment of the surface inspection apparatus of this invention. It is a perspective view which shows preferable 3rd Embodiment of the surface inspection apparatus of this invention. It is the top view which looked at the surface inspection apparatus of FIG. 5 from the S direction. It is a figure which shows the example by which the light for a detection is irradiated diagonally with respect to the irradiation object site | part of the surface of a to-be-measured body from a condensing optical system. It is a figure which shows the example of the surface defect in the irradiation object site | part of the surface of a to-be-measured body. It is a figure which shows preferable 4th Embodiment of the surface inspection apparatus of this invention. It is a figure which shows the example of a processing method which processes a deformation | transformation part as a surface defect in the irradiation object site | part of the surface of a to-be-measured body. It is a figure which shows the relationship between a dent depth measured value and image processing data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Object to be measured 2 Surface of object to be measured 10 Surface inspection device 11 Projecting unit 12 Condensing optical unit 13 Detection unit 14 Image processing unit 21 First lens 22 Second lens 30 Irradiation target portion 31 Light for detection 40 Linearly Formed light receiving image a First side of rectangular light b Second side of rectangular light

Claims (16)

A surface inspection device for inspecting the surface of a measured object,
A light projecting unit that emits light;
The light is changed to a rectangular light having a first side and a second side, the first side is enlarged, and the second side is reduced to form a linear detection light. A condensing optical unit for irradiating detection light toward the surface of the object to be measured;
A detection unit for forming the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape;
An image processing unit having a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measurement object;
With
The detection unit includes a screen that forms the light reception image formed in the linear shape, and a camera that captures the light reception image formed in the linear shape received by the screen as an image,
The length of the second side part of the detection light having a rectangular shape is sequentially reduced from the condensing optical part through the surface of the measured object until it reaches the screen,
The surface inspection apparatus, wherein the detection light reflected from the surface of the object to be measured is directly applied to the screen. The second side part of the detection light before entering the condensing unit closest to the measured object in the condensing optical unit having a plurality of condensing units consisting of a lens or a lens mechanism is b, The second side portion of the detection light emitted to the irradiation target site on the surface of the measurement object is b1, and the second side portion of the received light image formed on the screen is b2. When
The surface inspection apparatus according to claim 1, wherein a relationship of length of b> length of b 1> length of b 2 is satisfied.   The length of the first side portion of the detection light having the rectangular shape is sequentially increased from the condensing optical unit through the surface of the measured object until reaching the screen. The surface inspection apparatus according to claim 1 or 2. The first side portion of the detection light before entering the light collecting means closest to the measured object in the light collecting optical part having a plurality of light collecting means consisting of a lens or a lens mechanism is defined as a. The first side of the detection light emitted to the irradiation target site on the surface of the measurement object is a1, and the first side of the received light image formed on the screen is a2. When
4. The surface inspection apparatus according to claim 3, wherein a relationship of length of a2> length of a1> length of a is satisfied.   The image processing unit obtains edge position data from linear data of the linearly received light image captured by the camera, and the edge position data is obtained from an approximate curve obtained from the edge position data. The surface inspection apparatus according to claim 1, wherein the defect on the surface of the object to be measured is determined based on a deviation amount. A surface inspection device for inspecting the surface of a measured object,
A light projecting unit that emits light;
The light is changed to a rectangular light having a first side and a second side, the first side is enlarged, and the second side is reduced to form a linear detection light. A condensing optical unit for irradiating detection light toward the surface of the object to be measured;
A detection unit for forming the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape;
An image processing unit having a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measurement object;
With
The image processing unit acquires data of a plurality of edge positions on both sides of the linear shape from linear data of the light reception image formed in the linear shape, and the acquired plurality of edges for each one side of the linear shape A linear approximate line is calculated from the position data, the distance between the edge position data and the linear approximate line is calculated for each edge position data, and the calculated values on both sides of the calculated linear line are calculated. The surface inspection apparatus characterized by determining the said defect of the surface of the said to-be-measured object by the total value which totaled all the values with respect to the data of several edge position.   The said detection part has a screen which forms the light reception image formed in the said linear form, and a camera which takes in the said light reception image formed in the linear form received by the screen as an image, It is characterized by the above-mentioned. 6. The surface inspection apparatus according to 6.   The surface inspection apparatus according to claim 6, wherein the detection unit is a camera that captures the linearly received light reception image as an image.   The surface inspection apparatus according to claim 1, wherein the surface of the object to be measured is a flat surface.   The surface of the measured object is a cylindrical curved surface, and the condensing optical unit irradiates the detection light so that the longitudinal direction of the cylindrical curved surface and the second side portion are parallel or oblique. The surface inspection apparatus according to any one of claims 1 to 8, wherein   The surface inspection apparatus according to claim 1, further comprising a stage for holding the measured object and moving a position of the measured object with respect to the condensing optical system. . A surface inspection method for inspecting the surface of a measured object,
The light projecting portion irradiates light having a rectangular shape with a cross section having a first side and a second side,
A condensing optical unit enlarges the first side of the light of the light projecting unit and reduces the second side to form linear detection light, and the detection light is measured. Irradiate towards the surface of the body,
A detection unit having a screen and a camera forms an image of the detection light reflected from the surface of the object to be measured as a linearly received light image by the screen, and is received by the screen by the camera. Capture the light-receiving image formed in the linear form as an image,
The length of the second side part of the detection light having a rectangular shape is sequentially reduced from the condensing optical part through the surface of the measured object until it reaches the screen,
The detection light reflected from the surface of the object to be measured is directly applied to the screen,
A surface inspection method, wherein the image processing unit uses a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the object to be measured. The second side part of the detection light before entering the condensing unit closest to the measured object in the condensing optical unit having a plurality of condensing units consisting of a lens or a lens mechanism is b, The second side portion of the detection light emitted to the irradiation target site on the surface of the measurement object is b1, and the second side portion of the received light image formed on the screen is b2. When
The surface inspection method according to claim 12, wherein a relation of length of b> length of b 1> length of b 2 is satisfied.   The length of the first side portion of the detection light having the rectangular shape is sequentially increased from the condensing optical unit through the surface of the measurement object until reaching the screen. The surface inspection method according to claim 12 or 13. The first side portion of the detection light before entering the light collecting means closest to the measured object in the light collecting optical part having a plurality of light collecting means consisting of a lens or a lens mechanism is defined as a. The first side of the detection light emitted to the irradiation target site on the surface of the measurement object is a1, and the first side of the received light image formed on the screen is a2. When
The surface inspection method according to claim 14, wherein a relationship of length of a <b>2> length of a <b>1> length of a is satisfied. A surface inspection method for inspecting the surface of a measured object,
The light projecting portion irradiates light having a rectangular shape with a cross section having a first side and a second side,
A condensing optical unit enlarges the first side of the light of the light projecting unit and reduces the second side to form linear detection light, and the detection light is measured. Irradiate towards the surface of the body,
The detection unit forms an image of the detection light reflected from the surface of the measurement object as a light-receiving image formed in a linear shape,
The image processing unit has a deformed portion of the linearly received light image received by the detection unit as a defect on the surface of the measured object,
The defect on the surface of the object to be measured is obtained by acquiring data of a plurality of edge positions on both sides of the linear shape from the linear data of the light reception image formed in the linear shape. A linear approximate line is calculated from the acquired data of the plurality of edge positions, a distance between the edge position data and the linear approximate line is calculated for each of the edge position data, and then further, A surface inspection method comprising: determining by a total value obtained by summing all values of distances to the calculated data of the plurality of edge positions on both sides of the linear shape.

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