JPH0792099A - Surface layer defect detecting device - Google Patents

Abstract

PURPOSE:To detect a stripe cavity vertical (laid along the circumferential direction) to the axis of a cylindrical surface layer at a high speed. CONSTITUTION:In the surface layer defect detecting device having a subject support device for rotating a subject 3 to be inspected having a cylindrical surface layer around its axis 3a, an inspecting light emitting device for emitting an inspecting light laid along the axial 3a direction to the cylindrical surface layer of the subject 3, and a light receiving sensor 13 for detecting the scattered reflected light quantity from the surface layer, the inspecting light emitting device has a projector for emitting the inspecting light from the vicinity of both axial ends of the subject 3 toward the center part of the subject 3 surface in the axial 3a direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting defects in a surface layer of a cylindrical member, a cylindrical member or the like. INDUSTRIAL APPLICABILITY The present invention can be used to detect defects in the surface layer of a photoconductor drum used in an image output device such as a copying machine or a laser printer, or a fixing roller of a fixing device.

[0002]

2. Description of the Related Art Roll parts (parts having a cylindrical surface) such as photoconductor drums, fixing rolls or charging rolls used in the above copying machines and laser printers have a photosensitive layer or a protective layer on the surface of metal parts or rubber rolls. A cylindrical surface layer such as a layer is formed. For example, in a heat fixing roll, a cut metal pipe is coated with a surface layer using a fluororesin. The charging roll is formed by coating a surface layer made of a semiconductive material on a ground rubber roll. These roll parts are finished to have a surface roughness of about several μm to 10 μm by cutting or polishing, and a coating method such as an electrostatic coating method or a dip coating method is used to form a film on the surface. Various surface defects occur in these manufacturing processes.

Specific types and causes of defects will be described below. In the process of cutting and polishing the roll parts, "circumferential scratches" occur on the roll surface due to defective cutting and polishing. In the coating process, unevenness of the coating material causes “foreign matter” and “color irregularity” on the roll surface, and uneven coating conditions cause “dents” and “bulges”, and handling causes “dents” and “scratches”. , Etc. will occur. Defects on the surface of these parts often appear as small black spots or black streak images on the copy surface when the image is output, and some of them do not satisfy the quality standard of the output image. is there. Therefore, we inspect the appearance of the surface of all roll parts and eliminate defective products to ensure quality. The visual inspection has conventionally been performed by a visual inspection by an inspector. The visual appearance inspection has pointed out problems such as an increase in inspection cost and inspection man-hours, variation in inspection quality, difficulty in securing operator training time, and difficulty in securing inspection personnel due to fatigue work. In particular, the roll parts used in laser printers have recently become more problematic due to the increasing production quantity.

Therefore, as an automatic device for visual inspection work,
The following technology (J01) is known. (J01) (Technology described in Japanese Patent Laid-Open No. 5-107196) FIG. 8 is a schematic perspective view for explaining the conventional surface layer defect detection device described in the above publication. In FIG. 8, the light emitted from the fluorescent lamp 01 as the white diffused light source is applied to the surface of the photosensitive drum (that is, the object to be inspected) 03 as the band-shaped slit light by the slit 02. In this state,
A first detection position in which the light-receiving field of the line sensor (light-receiving sensor) 04 is set at the boundary line portion H1 extending in the longitudinal direction of the band-shaped slit light on the surface (surface layer) of the photoconductor drum 03, and the light-receiving field of view is band-shaped slit light. At the second detection position set at the central portion H2 of the above, the defect of the surface layer is detected from the light amount signals respectively detected.

That is, in the conventional technique described in this publication,
At the first detection position, irregularities on the surface of the surface layer, mechanical scratches, etc. are detected, and at the second detection position, a change in the film thickness of the transparent photosensitive layer inside the surface layer, impurities (foreign matter) in the surface layer.
Is detected. As a result of the research by the inventor of the present application, when the photosensitive layer is present inside the transparent layer on the surface such as the photosensitive drum, the change in the film thickness of the photosensitive layer inside the transparent layer is
It has been found that it is possible to detect with higher accuracy by detecting the amount of scattered reflected light from a portion further outside the boundary portion H1, that is, a portion (dark portion) that is slightly vaguely bright. However, in this case, the amount of light detected by the light receiving element is small, and it takes time to accumulate the light amount of the light receiving element. Therefore, it takes time to detect the change in the film thickness.

In the prior art (J01), a circular recess or an axial recess on the surface of a cylindrical photosensitive drum (inspection object) is detected at the first detection position. Next, this detection principle will be described with reference to FIG. FIG. 10 is a view of the cylindrical photosensitive drum (inspection object) 03 as seen from the axial direction. FIG. 10A shows a case where there is no defect on the surface, and FIG. 10B shows a point-like defect or axial direction on the surface. There is a defect 03a along it, as shown in FIG.
0C is a streak-like recess (defect) 03b along the circumferential direction on the surface
Indicates the presence of. The first detection position is the light source 01
Specular reflection optical axis 01a and the received light optical axis 0 of the line sensor 04
4a is slightly displaced and does not receive scattered light. However, if there is a dot-shaped recess (defect) or a recess 03a along the axial direction shown in FIG. 10B, the specular reflection optical axis 01a changes slightly in the circumferential direction due to the unevenness, and is aligned with the sensor optical axis 04a. Therefore, the scattered light is received.

However, the photosensitive drum (inspection object)
0 streak along the direction perpendicular to the axis of 03 (circumferential direction)
There is a problem that 3b is difficult to detect. Next, the reason for this will be described with reference to FIG. 11A. In FIG. 11A, the light source 01 and the slit 02 extending in the left-right direction are parallel to the axis of the photosensitive drum 03, and the surface of the photosensitive drum 03 is perpendicular to the axis of the photosensitive drum 03 (that is, the slit 02 and There are streaky depressions 03b in the (vertical) direction. By the way, the reflection direction of the light that has passed through a predetermined part of the slit 02 in the left-right direction and is incident on the recess 03b is deviated in the left-right direction. Therefore, when the light incident on the recess 03b is only light from a predetermined part in the left-right direction, the light receiving element of the line sensor 04 that detects the amount of reflected light from the recess 03b sensitively detects the recess 03b. can do. However, as shown in FIG. 11A, when the light passing through the slit 02 and entering the recess 03b enters from a wide range in the left-right direction, the recess 0
Due to the existence of 3b, if the recess 03b does not exist, the light incident on the light receiving element may not be incident or the light not incident may be incident. Therefore, the change in the amount of light incident on the light receiving element of the line sensor 04 that detects the amount of light reflected from the recess 03b is reduced. In this case, the recess 03
The light receiving element of the line sensor 04 that detects the amount of reflected light from b cannot detect the dent sensitively.

As a solution to the problems of the prior art (J01), the present applicant first applied for the following technology (J02). (J02) (Technology shown in FIG. 9, that is, Japanese Patent Application No. 4-27)
No. 0227) In FIG. 9, the light irradiation device 05 includes a light source 06 and a light-shielding plate 07 in the shape of an elongated cylinder that covers the periphery of the light source 06. The light shielding plate 07 has slits 08 and light shielding portions 09 that are perpendicular to the longitudinal direction and are alternately formed along the longitudinal direction. The light from the light source 06 is applied to the surface of the cylindrical inspection object 03 as a slit light in a lattice shape by the plurality of slits 08. In this case, a bright portion 012, a dark portion 013, and an intermediate brightness boundary portion 014 are generated on the surface of the cylindrical inspection object 03. If there is a streak-like recess 03b (along the circumferential direction) perpendicular to the axis of the object 03 to be inspected in this boundary portion 014, the amount of light incident on the line sensor 016 increases or decreases as compared with other portions due to the recess 03b. .
As a result, the light amount detection signal of the line sensor 016 changes, and the streak-shaped recess 0 along the direction perpendicular to the axis of the inspection object 03 is reduced.
3b can be detected. Next, the reason for this will be described with reference to FIG. 11B. As can be seen from FIG. 11B, the light incident on the recess 03b is only the light that has passed through the predetermined slit 08 disposed in the vicinity of the recess 03b. For this reason,
The light incident on the recess 03b is only light from a predetermined part in the left-right direction. Since the direction of most of the reflected light from the recess 03b in this case is shifted compared to the case of a normal reflecting surface, the light receiving element of the line sensor 04 that detects the amount of reflected light from the recess 03b is the same as in the case of FIG. 11A. The recess 03b can be detected more sensitively.

By combining the techniques of (J01) and (J02), the inventor of the present application combines the techniques of (J01) and (J02) with each other to form a line-shaped recess along the axis, which is a defect of the cylindrical surface layer, and a line-shaped recess perpendicular to the axis.
The following technology (J03) was created as a device that can detect other scratches on the surface layer.

(J03) (Technology shown in FIG. 12) FIG. 12 is a schematic perspective view for explaining a surface layer defect detecting device created by the inventor of the present application. In the surface layer defect detection device shown in FIG. 12, the light source 021 is covered with a cylindrical light shielding member 022. The cylindrical light shielding member 022 has a first slit pattern 023 formed of an elongated slit 023a extending along the axis thereof, and the cylindrical slit member 023 has a cylindrical shape at a position distant from the first slit pattern 023 in the circumferential direction. A plurality of slits 024a extending in the circumferential direction (direction perpendicular to the axis) of the light shielding member 022 arranged in a line along the axis.
And a slit pattern 024. The tubular shading member 022 is controlled in its rotational position by a rotating device (not shown). In FIG. 12, the inspection object 026 is conveyed from right to left, lifted by the lift device 027, and rotatably supported at the inspection position A.

Depending on the rotational position of the light shielding member 022,
The light emitted from the light source 021 is emitted from the cylindrical light shielding member 022.
Each of the slits 023a or 02 of the first slit pattern 023 or the second slit pattern 024 provided in
The cylindrical surface layer of the inspection object 026 is irradiated with light through 4a. For example, first, the emitted light from the light source 021 arranged above the inspection position A is the first slit pattern 0.
The object to be inspected 026 as one strip-shaped slit light by 23.
The surface is illuminated. Therefore, the boundary light receiving sensor 028
Scans the boundary line portion of the strip slit light, and the specular reflection light receiving sensor 029 scans the center line portion of the strip slit light. While rotating the inspection object 026, the entire surface of the inspection object 026 is scanned. By this inspection, it is possible to inspect streaky dents along the axis of the surface of the inspection object 026 and other defects. However, in this case, the detection sensitivity of the linear recess (extending in the circumferential direction) perpendicular to the axis of the surface of the object 026 to be inspected is not high. The object to be inspected 026 shown in FIG.
Is a fixing roll whose surface layer does not have a transparent layer and a photosensitive layer inside thereof. Therefore, since it is not necessary to inspect the film thickness of the photosensitive layer inside the surface layer, scanning of the dark portion outside the boundary portion (that is, scanning of the portion where the photosensitive layer film thickness can be inspected with high accuracy) is performed. Not not.

Next, the cylindrical light shielding member 022 is rotated to illuminate the object to be inspected 026 with the lattice slit light that passes through the second slit pattern 024. At this time, on the cylindrical surface of the object to be inspected 026, three types of illumination areas are formed along the axial direction, that is, a bright portion, a dark portion, and their boundary portion. In this state, the lattice slit light sensor 031 scans the surface of the inspected object 026 and detects the amount of light reflected from the surface. Then, while rotating the object to be inspected 026, the entire surface thereof is scanned. The direction (circumferential direction) perpendicular to the axis of the cylindrical surface of the object 026 in this inspection
The streak-shaped depression along the line can be detected with the highest sensitivity by detecting the reflected light from the boundary between the bright part and the dark part on the surface of the object to be inspected 026.

Therefore, this second slit pattern 02
In the inspection using 4, that is, in the inspection in which the cylindrical surface of the inspection object 026 is illuminated by the lattice slit light, the inspection object 026 is rotated once, and is present in the bright portion and the dark portion of the inspection object 026 surface. The above-mentioned circumferential streaky depressions cannot be detected with high sensitivity. Therefore, in order to detect the streak-shaped recess along the direction perpendicular to the axis of the cylindrical surface of the object to be inspected 026 with high sensitivity over the entire surface of the object to be inspected 026, When the first rotation is performed, it is necessary to rotate the inspection object 026 again to perform the inspection in a state where the light portion or the dark portion becomes the boundary portion between the light portion and the dark portion.

To this end, the second rotation of the inspection object 026 is performed so that the portion which was the light portion or the dark portion in the first rotation of the inspection object 026 becomes the boundary portion. 0
The position of the lattice slit light with which the cylindrical surface of 26 is irradiated may be shifted in the axial direction. The positions of the bright portion, the dark portion, and the boundary portion of the cylindrical surface of the inspection object 026 illuminated by the lattice slit light are displaced in the axial direction with respect to the cylindrical surface of the inspection object 026. By
The portion that was the bright portion or the dark portion in the first rotation can be set as the boundary portion in the second rotation. And
The position of the lattice slit light (that is, the position of the second slit pattern 024) is shifted in the axial direction until the entire surface of the inspection object 026 is scanned as a boundary portion between the bright portion and the dark portion. The inspection body 026 is rotated. By rotating and inspecting the inspected object 026 several times in this manner, it is possible to detect the streak-shaped recess along the circumferential direction with high accuracy over the entire surface of the inspected object 026.

[0015]

[Problems to be Solved by the Invention] However, the above (J03)
The defect detection method of (1) has a problem that the inspection object 026 must be rotated a plurality of times in order to inspect the entire peripheral surface of the inspection object 026 with high accuracy, and the inspection time becomes long. In view of the above circumstances, the present invention has the following contents. (O01) To be able to detect at high speed a streak-shaped recess (along the circumferential direction) perpendicular to the axis of the cylindrical surface layer.

[0016]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. Note that the reference numerals of the elements of the embodiments are enclosed in parentheses. Further, the reason why the present invention is described in association with the reference numerals of the embodiments described later is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.

In order to solve the above-mentioned problems, the surface layer defect detection apparatus of the present invention comprises an object support device for rotating an object (3) having a cylindrical surface layer around its axis,
An inspection light irradiation device that irradiates the cylindrical surface layer of the inspection object (3) with inspection light along the axis (3a) direction, and a light receiving sensor (13) that detects the amount of scattered reflected light from the surface layer. The surface layer defect detection device provided is characterized by having the following requirements: (Y01) The inspection light irradiation device is the inspection object (3).
Axis (3a) on the surface of the DUT (3)
To have a projector that emits inspection light toward the center of the direction.

(Supplementary explanation of means for solving the problem)
In the invention of the present application, the “inspection object (3)”
May be solid or hollow and means both a solid cylinder and a cylinder. Further, when the projector uses a device having a function of emitting a spot-shaped inspection light having directivity, light is not wasted, which contributes to energy saving and can improve inspection speed. When the spot-shaped inspection light is used, its optical axis direction is set to be substantially parallel to the rotation axis direction of the inspection object (3) for use. Such a light projector is, for example, a light source including a point light source and a fiber bundle that guides the light emitted from the point light source to both end portions of the inspection object (3), and collects the light emitted from the light guide. It can be configured by a lens or the like for irradiating the surface of the inspection object (3).

[0019]

Next, the operation of the present invention having the above features will be described. In the surface layer defect detection device of the present invention having the above-mentioned characteristics, the projector of the inspection light irradiation device is inspected from near both ends in the axis (3a) direction of the inspection object (3) having the cylindrical surface layer. The inspection light is emitted toward the central portion of the surface of the body (3) in the direction of the axis (3a). This inspection light travels in the direction of the axis (3a) along the cylindrical surface of the inspection object (3). When the surface of the object (3) to be inspected irradiated with this inspection light has no scratches or irregularities, light is only specularly reflected on the surface, and scattered reflection light does not occur. The light receiving sensor (13) for detecting the amount of scattered reflected light from the surface layer of the object to be inspected (3) hardly receives scattered reflected light when the surface layer has no scratches or irregularities, but scratches or irregularities. If there is such a problem, since the scattered reflected light is received, it is possible to detect a defect in the surface layer of the inspection object (3).

[0020]

EXAMPLES Examples of the present invention will now be described with reference to the drawings, but the present invention is not limited to the following examples. In order to facilitate understanding of the explanation below,
Cartesian coordinate axes X-axis, Y-axis, and Z-axis are defined in the directions of arrows X, Y, and Z that are orthogonal to each other in the drawing, and the arrow X direction is the front, the arrow Y direction is the left, and the arrow Z direction is the up. In this case, the direction opposite to the X direction (front) (-X direction, that is, the opposite X direction) is backward, the opposite direction to the Y direction (left) (-Y direction, that is, the opposite Y direction) is the right direction, and the Z direction ( The direction opposite to the upper direction (-Z direction, that is, the anti-Z direction) is the lower direction. Also,
It is called the front-back direction or the X-axis direction including the front (X direction) and the back (-X direction), and the left-right direction or the Y-axis direction including the left (Y direction) and the right (-Y direction), The upper direction (Z direction) and the lower direction (-Z direction) will be referred to as the vertical direction or the Z-axis direction. Furthermore, in the figure, "○" is put in "○".
The one with "" means an arrow from the back of the paper to the front, and the one with "x" in "○" means an arrow from the front to the back of the paper.

(Embodiment 1) FIG. 1 is an overall schematic perspective view of Embodiment 1 of a surface layer defect detecting apparatus of the present invention. FIG. 2 is a diagram showing the projection angle of the irradiation light with respect to the surface of the roll to be inspected (inspection object). FIG. 3 is a view showing the irradiation light on the inspection surface of the roll to be inspected and the light receiving field of the optical sensor. FIG. 4 is an explanatory diagram of the reflected light of the light applied to the inspection surface. FIG. 5 is a diagram for explaining the reflection characteristics for each defect type. FIG. 6 is an explanatory diagram of sensor signal waveforms of the line sensor.

In FIG. 1, the entire surface layer defect detecting device is indicated by U. Light emitted from a point light source 1 such as a halogen light source is guided to both ends 4a and 4b of a roll to be inspected (object to be inspected having a cylindrical surface layer) 3 by a light guide 2 composed of an optical fiber bundle. The light guide 2 is guided from the downward direction (-Z direction) of the roll 3 to be inspected, and the light emitted from the tip of the light guide 2 is made parallel to the direction of the axis 3a of the roll 3 to be inspected by using the right-angle mirror 6. Right angle mirror 6
Is for downsizing the entire surface layer defect detection device U in the width direction (X-axis direction).

Since the light emitted from the tip of the light guide 2 has a constant spread angle, it is condensed by the condenser lens 7 to form the beam-shaped inspection light 8. The beam-shaped inspection light 8 emitted from the condenser lens 7 is linearly applied to the inspection surface (cylindrical surface layer) 10 of the inspection target roll 3. By irradiating the inspection light 8 from both ends 4a, 4b of the inspected roll 3 toward the central portion of the inspected roll 3, the entire width (axial length) of the inspected roll 3 is illuminated. The reduction optical system 12 in which the light receiving field 11 is aligned on the inspection surface 10 of the roll to be inspected 3 is used to converge the scattered light component from the surface of the roll to be inspected (3) to the line sensor (light receiving sensor) 13. By scanning with the line sensor 13 while rotating the roll 3 to be inspected, a sensor signal of scattered reflected light from the inspection surface 10 of the roll 3 to be inspected is obtained. Although the means for rotating the roll 3 to be inspected is not shown, conventionally known means for rotating the cylindrical member can be adopted. The obtained sensor signal is subjected to a defect signal extraction / determination device 14 to determine a defect and a non-defective product. A dust removing means 15 for blowing out air for removing dust and dust on the inspected roll 3 is arranged along the surface of the inspected roll 3.

Next, the projection angle of the inspection light 8 with respect to the inspection surface 10 of the inspected roll 3 will be described with reference to FIGS. In particular, the authors used the inspection light 8 to detect defects in the circumferential direction that were difficult to detect, especially when the conventional slit light of the fluorescent lamp was used.
Was radiated from the direction of the end of the roll 3 to be inspected while appropriately changing the projection angle, and visually observed. As a result, when viewed from above the inspected roll 3 as shown in FIG. 2, the inspection light optical axis 16 makes the angle (projection angle) θ formed by the central axis 3a of the inspected roll 3 approximately 0. (That is, the inspection optical axis 16 and the central axis 3a are values that are substantially parallel to each other), and the inspection surface 10 of the roll 3 to be inspected is irradiated.
The distance L between the inspection optical axis 16 and the inspection surface 10 of the inspected roll 3 is preferably close to each other. From the experiment, the angle θ is
It is preferable that the distance L is 0 to 5 degrees and the distance L is about 10 mm.

As shown in FIG. 3, the optical axis 16 of the inspection light 8 is
Is substantially parallel to the central axis 3a of the roll 3 to be inspected and is aligned with the light receiving field 11 of the line sensor (light receiving sensor) 13 on the roll 3 to be inspected.
Adjust the position of. The adjustment method is to use a reference inspected roll having a scribe line on the surface of the inspected roll 3 parallel to the axial direction, and fix the scribe line at a predetermined position to fix the light receiving field 11 and the inspection optical axis 16. The positions may be adjusted so that each of them matches the marking line. In addition, the condenser lens 7
(See FIG. 1) irradiates the inspection surface 10 of the roll 3 to be inspected in a straight line, so that the focal length is preferably long. From the experiment, the lens focal length is preferably about 30 mm. In this embodiment, by selecting the focal length of the condenser lens 7 and the projection angle θ, a wide range of the roll 3 to be inspected is collectively irradiated with light substantially parallel to the axis along the inspection surface 10. can do. In the experiment, length about 150mm, width 10mm
Irradiate a range of degree and both ends 4 of the roll 3 to be inspected
By irradiating from a and b, the cylindrical surface layer of the roll 3 to be inspected up to a length of 300 mm can be inspected. This inspection range is the length of the inspected rolls of a copying machine or laser printer capable of printing up to A3 size, which is practically sufficient.

(Operation of First Embodiment) Next, the operation of the first embodiment having the above-mentioned structure will be described. In FIG. 4, the optical axis 16 of the inspection light 8 to be irradiated is a direction along the axis 3a having no curvature on the inspected roll 3, so that the reflection direction is irrespective of the diameter of the inspected roll 3. It is constant. The inspection surface 10 of the inspected roll 3 is a surface layer formed by coating,
It is a reflective surface with specularity. Therefore, the roll 3 to be inspected
The inspection light 8 radiated in the axial direction having no curvature above is incident on the inspection surface 10 at a minute angle θ, and the reflected light 18 is in the direction of the minute angle θ along the plane regardless of the diameter of the roll 3 to be inspected. Reflect on. The light-receiving optical axis 19 of the line sensor 13 is in a direction perpendicular to the inspection surface 10, and when the inspection surface 10 is normal, the light is scattered from the inspection surface 10 regardless of the illuminance on the inspection surface 10 of the roll 3 to be inspected. Almost no light is received. On the other hand, when there is a defect on the surface, scattered light 20 is generated. Scattered light 2
The magnitude of 0 is proportional to the illuminance on the inspection surface 10 of the inspection target roll 3 by the irradiation inspection light 8. Therefore, the contrast of the defect portion can be increased by increasing the illuminance on the inspection surface 10 of the inspection target roll 3. In the experiment, a halogen light source of 150 W was used, and an illuminance of 2000 LUX was obtained on the inspection surface 10 of the roll 3 to be inspected at the above-mentioned projection angle, so that the defect portion could be easily observed.

In FIG. 5, the inspection surface 1 of the roll 3 to be inspected
For the defect 21 having a protrusion of 0, the irradiated light is strongly scattered on the side surface of the protrusion. With respect to the dent defect 22 due to cracks in the surface layer, the underlying rubber roll and the metal inspection roll have a scattering surface with an average surface roughness of 10 μm or more, and therefore the dent portion shines white. With respect to the defect 23 such as a flat deposit without unevenness, the surface of the deposit is generally a scattering surface and thus shines white. It is difficult to detect the defect 24 continuous in the axial direction due to the unevenness in the circumferential direction and the continuous defect in the axial direction with respect to the linear continuous wrinkles or other irregularities on the surface. 25 can be detected.

FIG. 6 is a diagram showing a defect signal on the line sensor 13. Since almost no reflected light is received from the normal surface portion 31, it is close to the dark output level of the line sensor, and at the defective portion 32. A defect signal is obtained in the positive direction by the scattered light. Moreover, almost no scattered light signal due to the surface roughness of the normal surface portion is detected, and the ratio of the signal height 33 of the defective portion to the signal fluctuation width 34 of the normal portion is 5 to 10 or more, which is a strong defect signal. Is obtained. The light irradiation method of the above-described embodiment can detect dust on the roll 3 to be inspected with extremely high sensitivity. For this reason, the air dust removing means 15 (see FIG. 1) is installed immediately before the light receiving position of the line sensor, or the defect and dust to be detected are the geometric shape on the image such as size and line width. Since different characteristics are different, it is necessary to extract only the defects by the judgment device 14 shown in FIG.

(Second Embodiment) Next, a second embodiment of the surface layer defect inspection apparatus of the present invention will be described with reference to FIG. In addition,
In the description of the second embodiment, constituent elements corresponding to those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but is configured similarly to the first embodiment in other points. (S01) In the first embodiment, the light projector including the halogen light source 1 and the light guide 2 was used to irradiate light from both ends of the roll 3 to be inspected substantially parallel to the direction of the axis 3a of the roll 3 to be inspected. In the second embodiment, as shown in FIG. 7, the fluorescent tube 21a, 21b is used to inspect the roll 3 to be inspected.
A point illuminated from the edge. Also in this second embodiment, the first embodiment
Similarly to, defects in the cylindrical surface layer can be detected.

In the first and second embodiments, the inspection light can be irradiated along the axial direction of the inspection surface 10 of the inspection target roll 3 having no curvature. Therefore, minute recesses and protrusions such as foreign matter generated on the curved surface of the roll to be inspected, which has a small roll diameter to be inspected and has a small radius of curvature, which is often used in laser printers, can be detected with high accuracy.

[0031]

The effects of the surface layer defect detecting device of the present invention described above can achieve the following effects. (E01) Since the light to be inspected is applied to the entire width of the roll substantially evenly from both ends, the information of the entire width of the roll to be inspected can be taken in at one time by the conventional method for moving the slit light shielding plate. The inspection can be speeded up in comparison.

[Brief description of drawings]

FIG. 1 is an overall schematic perspective view of a first embodiment of a surface layer defect detection device of the present invention.

FIG. 2 is a diagram showing a projection angle of irradiation light with respect to a surface of a roll to be inspected.

FIG. 3 is a diagram showing a projection angle of irradiation light with respect to an inspection surface of a roll to be inspected and a light receiving field of view of an optical sensor.

FIG. 4 is an explanatory diagram of reflected light of light irradiated on the inspection surface.

FIG. 5 is a diagram illustrating reflection characteristics for each defect type.

FIG. 6 is an explanatory diagram of sensor signal waveforms of a line sensor.

FIG. 7 is a schematic perspective view of a second embodiment of the surface layer defect detection device of the present invention.

FIG. 8 is a schematic perspective view for explaining a conventional surface layer defect detection device.

FIG. 9 is a schematic perspective view for explaining another conventional surface layer defect detection device.

FIG. 10 is a view for explaining the operation of the conventional surface layer defect detection apparatus shown in FIGS. 8 and 9, and the cylindrical photosensitive drum (inspected object) 03 is viewed from the axial direction. FIG. 10A is a diagram showing a state where there is no defect on the surface, and FIG.
0B is a diagram showing a state where dot-like defects or defects 03a along the axial direction are present on the surface, and FIG. 10C is a diagram showing a state where streak-like recesses (defects) 03b along the circumferential direction are present on the surface.

FIG. 11 is a view for explaining the operation of the conventional surface layer defect detection apparatus shown in FIGS. 8 and 9, and FIG. 11A is a slit extending in the axial direction of an inspection object having a cylindrical surface layer. FIG. 11B is a view for explaining the operation when using the (1), FIG.
FIG. 7 is an explanatory view of the operation when a large number of slits extending in the direction of the axis are provided along the axis.

FIG. 12 is an explanatory diagram of another surface layer defect detection device invented by the present inventor.

[Explanation of symbols]

3 ... Inspected object, 3a ... Axis (axis of inspected object), 13 ... Light receiving sensor

Claims (1)

[Claims] 1. An inspection object supporting device for rotating an inspection object having a cylindrical surface layer around its axis, and an inspection for irradiating an inspection light along the axial direction on the cylindrical surface layer of the inspection object. In a surface layer defect detecting device comprising a light irradiation device and a light receiving sensor for detecting the amount of scattered reflected light from the surface layer,
A surface layer defect detection device having the following requirements: (Y01) The inspection light irradiation device inspects from the vicinity of both axial ends of the inspected object toward the axial center part of the inspected object surface. Must have a light projector that emits light.