JP3905119B2 - Surface inspection device - Google Patents

Description

  The present invention relates to a surface inspection apparatus that optically detects mainly scratches on a surface of an object to be inspected or foreign matters on the surface.

  For example, an optical surface inspection apparatus is generally used for automatically inspecting scratches on the surface of a processed object to be inspected or foreign matters on the surface. Such a surface inspection apparatus, although not shown, condenses inspection light projected from a light source on the surface of an object to be inspected via an objective lens, and receives the reflected light by a photosensor via another objective lens. The amount of received light is compared with a preset threshold value to detect surface scratches or foreign matter on the surface. And the spreading | diffusion of the surface is coped with by moving a light projection part and a light-receiving part along the surface of a to-be-inspected object, or moving a to-be-inspected object.

  However, in the above-described conventional surface inspection apparatus, when the object to be inspected is an inner peripheral surface of a cylindrical shape such as an engine cylinder, a brake cylinder, a compressor cylinder, and other various operating cylinders, the object is cast on the inner peripheral surface. There is a problem that it is difficult to face the light part and the light receiving part, making measurement difficult.

  In addition, even if the surface of the object to be inspected is flat, the area that can be inspected at a time is narrow, so the inspection device or the object to be inspected must be reciprocated many times while shifting the inspection area little by little, There was a problem that workability was bad.

  Accordingly, the object of the present invention is to easily inspect the inner peripheral surface of the inspection object when it is cylindrical, and when the surface of the inspection object is a flat surface, the number of reciprocating movements of the inspection apparatus or the inspection object It is an object of the present invention to provide a surface inspection apparatus that can improve workability by reducing the number of steps.

In order to achieve the above object, a surface inspection apparatus of the present invention includes a projecting optical fiber that projects inspection light from a light source onto the surface of an inspection object, and a receiving optical fiber that receives reflected light from the inspection object of the inspection light; A surface inspection apparatus for detecting a scratch on the surface of an object to be inspected or a foreign matter on the surface by detecting the amount of reflected light received by the receiving optical fiber and comparing and judging the magnitude of the detected amount In
A plurality of the receiving optical fibers are arranged around the projecting optical fiber, and the projecting optical fiber and the receiving optical fiber are bound to each other and inserted and held in a fiber holding cylinder,
While converging the inspection light emitted from the projecting optical fiber, the path is changed to irradiate the surface of the object to be inspected substantially perpendicularly, and the reflected light is similarly focused while the path is changed to change the receiving optical fiber. The light collecting means and the optical path changing means to be returned to the front of the fiber holding cylinder,
A rotation means for rotating at least the optical path changing means about the axis of the fiber holding cylinder;
The rotating means has a hollow cylindrical output shaft that is rotated by an electric motor, and an optical path support cylinder that is attached to the tip of the output shaft and at least the optical path changing means is attached,
The fiber holding cylinder is inserted into the output shaft.

  According to the surface inspection apparatus of the present invention, the inspection light emitted from the projecting optical fiber is focused through the condensing unit and the optical path changing unit, and the surface of the inspection object is irradiated almost perpendicularly while changing the optical path. The light reflected by the surface of the object to be inspected is converged through the same condensing means and optical path changing means as described above, and returned to the receiving optical fiber while changing the optical path. Therefore, it is possible to detect scratches and foreign matter on the surface of the object to be inspected by detecting the amount of the reflected light with a photo sensor or the like and comparing with a previously input threshold value or the like.

  In this case, the projecting optical fiber and the receiving optical fiber are bundled together and inserted and held in the fiber holding cylinder, and the light collecting means and the optical path changing means are attached in front of the fiber holding cylinder, so that the object to be inspected is a cylinder. Even when the inner peripheral surface is inspected, it is possible to insert the tip portion into a cylindrical inspection object.

  In addition, when the optical path support tube is rotated by the electric motor via the output shaft, the optical path changing means rotates accordingly. Therefore, the point where the inspection light is irradiated, that is, the inspection area is moved with the rotation of the optical path changing means. It is possible to widen the area that can be inspected when the surface inspection apparatus and the inspection object are at a certain relative position.

  According to one of the preferred embodiments of the present invention, the optical path changing means is a reflecting mirror or a prism, and the light collecting means is a convex lens. In this case, the optical path can be changed relatively freely according to the target object to be inspected by the arrangement and combination of the reflecting mirrors or prisms.

  According to another preferred aspect of the present invention, the optical path changing means and the light condensing means are constituted by concave mirrors. In this case, since the optical path change and the condensing can be performed simultaneously with one concave mirror, the number of parts can be reduced.

  Furthermore, according to a preferred aspect of the present invention, the optical path changing means changes the optical path in a direction perpendicular to the axis of the fiber holding cylinder.

  According to this, for example, when inspecting the inner peripheral surface of a cylindrical inspection object, the inner peripheral surface can be inspected annularly with a predetermined width by making the optical path changing means go around. Alternatively, the entire inner peripheral surface can be inspected with good workability by repeating the above operation while moving the inspection object little by little in the axial direction.

  Furthermore, according to another preferable aspect of the present invention, the optical path changing means changes the optical path to a position eccentric with respect to the axis of the fiber holding cylinder.

  According to this, for example, when the surface of the object to be inspected forms a flat surface, the optical path changing means makes a round to inspect the surface so as to draw a circular trajectory. By repeating the above operation while moving each one, it is possible to inspect the surface of the inspection object with the circular diameter width, thereby reducing the number of reciprocating movements of the inspection apparatus or the inspection object and improving workability. it can.

  Furthermore, according to another preferred aspect of the present invention, the surface inspection apparatus inspects the inner surface of the inspection object, and has means for moving the inspection object relative to the cylinder axis direction. It consists of what is.

  Furthermore, according to another preferred aspect of the present invention, the optical path support tube is attached to the tip end portion of the output shaft by screwing.

  According to the present invention, the optical path changing means facing the surface of the object to be inspected is rotated around the axis of the fiber holding cylinder by the rotating means, thereby changing the optical path of the inspection light irradiation point, that is, the inspection area. It can be moved with the rotation of the means, and the area that can be inspected when the surface inspection apparatus and the inspection object are at a certain relative position can be expanded.

  Also, in a preferred aspect of the present invention, when the optical path changing means changes the optical path in a direction perpendicular to the axis of the fiber holding cylinder, for example, the inner peripheral surface of a cylindrical object to be inspected is inspected. In this case, by rotating the optical path changing means once, the inner peripheral surface can be inspected in an annular shape with a predetermined width. Therefore, by repeating the above operation while moving the inspection device or the inspection object little by little in the axial direction. The entire inner peripheral surface can be inspected with good workability.

  Furthermore, in another preferable aspect of the present invention, when the optical path changing means changes the optical path to a position eccentric with respect to the axis of the fiber holding cylinder, for example, when the surface of the object to be inspected forms a flat surface. By rotating the optical path changing means once, it is possible to inspect the plane so as to draw a circular locus, and by repeating the above operation while moving the inspection device or the inspection object little by little, the circular diameter width Since the surface of the object to be inspected can be inspected, the number of reciprocating movements of the inspection apparatus or the object to be inspected can be reduced and workability can be improved.

  1 to 3 show an embodiment of a surface inspection apparatus according to the present invention. FIG. 1 is a cutaway plan view of a main part showing a state in which an inner surface of a hollow cylindrical inspection object is inspected using the surface inspection apparatus, and FIG. 2 is an end view of a fiber holding cylinder of the surface inspection apparatus. FIG. 3 is a block diagram showing an example of a detection circuit used in the surface inspection apparatus.

  A light projecting optical fiber 3 for projecting inspection light from the light source 2 (see FIG. 3) of the light source unit 12 to the inner surface 1a of the inspection object 1, and the inspection light from the inner surface 1a of the inspection object 1 Two receiving optical fibers 4 a and 4 b that receive the reflected light are bundled together and housed in the fiber holding cylinder 5. Note that there may be a plurality of projecting optical fibers and receiving optical fibers. Preferably, a plurality of receiving optical fibers, more preferably an even number of receiving optical fibers are arranged around one projecting optical fiber. In this embodiment, as shown in FIG. 2, the projecting optical fiber 3 is disposed in the vicinity of the axis 5 </ b> C of the fiber holding cylinder 5, and the receiving optical fibers 4 a and 4 b are disposed adjacent to the projecting optical fiber 3. As the light source 2, a light emitting diode, a laser, a lamp, or the like is used.

  The fiber holding cylinder 5 is formed by forming the armature shaft 9 a of the electric motor 9 in a hollow cylinder shape and is inserted into the hollow cylinder shape of the armature shaft 9 a, and the motor frame 9 b of the electric motor 9 is the right end of the fiber holding cylinder 5. The part is fixedly supported. The right ends of the projecting optical fiber 3 and the receiving optical fibers 4a and 4b protrude outward from the armature shaft 9a. The armature shaft 9a is pivotally supported on the motor frame 9b by a bearing 9c.

  An optical path support cylinder 8 is attached to the tip of the hollow cylindrical element shaft 9a by means such as screwing. In the optical path support cylinder 8, a convex lens 6 which is an example of a condensing means LC for condensing the inspection light onto the inner surface 1a of the inspection object 1 and condensing the reflected light onto the receiving optical fibers 4a and 4b, and the inspection A reflecting mirror 7 is provided as an example of an optical path changing means LA that changes the optical path of the light A and the reflected light B approximately at right angles to the axis 5C of the fiber holding cylinder 5.

  That is, the convex lens 6 is supported inside the optical path support tube 8 by the lens receiver 6a, and the reflecting mirror 7 is supported by the reflecting mirror mounting arm 7a. In this case, for example, by moving the lens receiver 6a and the reflector mounting arm 7a using a known adjusting screw mechanism, the support position and the support angle of the convex lens 6 and the reflector 7 with respect to the optical path support tube 8 can be freely set. It can also be adjusted. Further, the distal end portion of the optical path support cylinder 8 is closed with an end plate 8 a, and a transmission hole 8 b is opened at one place on the peripheral wall of the optical path support cylinder 8.

  The inspection light projected from the projecting optical fiber 3 is collected by the convex lens 6 and reaches the reflecting mirror 7, where the optical path is changed at right angles and passes through the transmission hole 8 b, and the inner surface of the object 1 to be inspected. The light is projected to a specific inspection range R of 1a. Then, the light reflected in the inspection range R reaches the reflecting mirror 7 again through the transmission hole 8b, is reflected by the reflecting mirror 7, returns on the optical path opposite to the above, is condensed by the convex lens 6, and is dotted in the figure. As shown in FIG. 4, the light is received by the receiving optical fibers 4a and 4b.

  In this embodiment, when the electric motor 9 operates and the armature shaft 9a rotates, the optical path support cylinder 8 attached to the tip of the armature shaft 9a rotates, and the position of the inspection range R Is moved along the circumferential direction of the inner surface 1a of the inspection object 1 and the optical path support tube 8 is rotated once, the inspection is ended in an annular shape on the inner surface of the inner surface 1a of the inspection object 1. Therefore, in this embodiment, the electric motor 9 and its armature shaft 9a constitute the rotating means RM of the optical path changing means.

  In addition to the above, various means such as those using an interlocking mechanism such as a pulley or a gear can be adopted as the rotating means RM. For example, even when an electric motor is used, the armature shaft is not formed into a hollow cylindrical shape as shown in FIG. 1, but an output shaft of an appropriate transmission mechanism is formed into a hollow cylindrical shape, and a fiber is connected to the output shaft. The holding cylinder 5 may be inserted, and the optical path support cylinder 8 may be coupled to the output shaft. Further, the rotating means RM can be structured to rotate only LA that is the optical path changing means.

  The right ends of the receiving optical fibers 4 a and 4 b are inserted into the long flexible tube 10 and connected to the inspection calculation unit 11. The inspection calculation unit 11 compares the amount of light received by the receiving optical fibers 4a and 4b with a preset threshold value, detects surface scratches, foreign matter, and the like, and outputs necessary display, printing, and the like. In the inspection calculation unit 11, the received light amount is handled as an analog electric signal or a digital electric signal.

  An example of the circuit configuration of the inspection calculation unit 11 and the light source unit 12 will be described. As shown in FIG. 3, the right ends of the receiving optical fibers 4a and 4b are connected to photosensors 24a and 24b, and the photosensors 24a and 24b are amplification circuits. 25a and 25b. A threshold value setting circuit 26 that converts the amount of received light when the inner surface 1a of the inspection object 1 is clean and has no foreign matter attached to it into a voltage value, and sets and inputs this voltage value as a threshold value. Are connected to the comparison circuit 27.

  The comparison circuit 27 compares the outputs from the amplification circuits 25a and 25b with threshold values to determine the presence or absence of scratches or foreign matter on the surface, and instructs the processing circuit 28 on the determination result. Necessary display, printing, etc. for a scratch or a foreign object are output.

  In order to inspect the entire inner surface 1 a of the inspection object 1, it is necessary to relatively move the surface inspection apparatus in the cylinder axis direction of the inspection object 1. As this method, either a method of moving the inspection object 1 while fixing the surface inspection apparatus or a method of moving the surface inspection apparatus while fixing the inspection object 1 may be adopted. . In this embodiment, the inspection object 1 remains stationary, and the surface inspection apparatus is moved in the cylinder axis direction of the inspection object 1 by the moving means TM.

  That is, by using the linear motor 28 as the moving means TM, the moving element 28a of the linear motor 28 is attached to the motor frame 9b of the electric motor 9, and the moving element 28a inserted through the stator 28b of the linear motor 28 is moved forward and backward to perform surface inspection. The device is moved back and forth. If this mechanical moving means TM is used, the surface inspection device cannot be directly viewed by setting the surface inspection device so that the axis 5C is in a predetermined position with respect to the inner surface 1a of the object 1 to be inspected. Since the light can be accurately condensed and projected on the specific inspection range R of the inner surface 1a, the inspection efficiency is improved.

  Next, the operation of the surface inspection apparatus having the configuration shown in FIG. 1 will be described. The stator 28b of the linear motor 28 is set parallel to the inner surface 1a of the inspection object 1, and the linear motor 28 is driven to insert the optical path support cylinder 8 into the inspection object 1. If the object to be inspected 1 is cylindrical, the optical path center 8C of the optical path support cylinder 8 is aligned with the axis of the object 1 to be inspected.

  When the armature shaft 9a of the electric motor 9 is rotated, the inspection light from the projecting optical fiber 3 is sequentially projected on the entire circumference of the inner surface 1a of the object to be inspected, and the reflected light is sequentially transmitted from the entire circumference of the inner surface 1a. Light is received by the receiving optical fibers 4a and 4b.

  That is, the inspection light from the light source 2 is slightly condensed by the convex lens 6 and reaches the reflecting mirror 7 as shown by the solid line in FIG. 1, where the optical path is changed at right angles and the inspection object 1 is changed. The light is condensed and projected onto a specific inspection range R of the inner surface 1a. The inspection light becomes reflected light in this narrow range, reaches the reflecting mirror 7, is condensed by the convex lens 6, and is received by the left and right receiving optical fibers 4a and 4b as indicated by dotted arrows.

  Thus, the reflected light reflected from the inspection range R of the inner surface 1a of the object to be inspected 1 is received by the photosensors 24a and 24b from the right and left receiving optical fibers 4a and 4b, and the reflected light is converted into voltage and amplified. The signals are amplified by the circuits 25a and 25b. If there is a scratch or foreign matter attached to the inspection range R, the reflected light from the inspection range R is scattered by the scratch or the like, and the amount of light received by the photosensors 24a and 24b is smaller than the amount of light received when there is no scratch or the like. As a result, the output voltage values of the amplifier circuits 25a and 25b become a voltage value when there is no scratch or the like, that is, a value lower than the threshold value.

  The comparison circuit 27 compares the average value of the output voltage values from the amplifier circuits 25a and 25b with the threshold value, determines that there are surface scratches, foreign matter, and the like, and instructs the processing circuit 28 of the determination result. In response to this instruction, the processing circuit 28 constituted by a TTL circuit outputs necessary indications and alarms for internal surface scratches or foreign matters to the monitor, an instruction to stop the operation of the surface inspection apparatus, and the like. Display, alarm, etc. will be printed out.

  Although not shown, a differential amplifier circuit and an inverting circuit are added to the circuit of FIG. 3, for example, the output of one amplifier circuit 25b is inverted and input to the differential amplifier circuit, and the other amplifier circuit 25a. The detection sensitivity of the comparison circuit 27 can be improved. Further, if the light receiving efficiency of the light receiving optical fiber is improved by making the optical path changing means LA and the light collecting means LC appropriate, only one light receiving optical fiber is sufficient.

  As described above, when the optical path support cylinder 8 placed on the inner surface 1a of the inspection object 1 is rotated around the axis 5C of the fiber holding cylinder 5 by the electric motor 9, the inner surface 1a of the inspection object 1 is obtained. The inspection light from the projecting optical fiber 3 is sequentially projected all around, the reflected light is sequentially received by the receiving optical fiber from the entire inner surface, and the inner surface 1a of the inspection object 1 can be inspected in an annular shape. . The entire inner peripheral surface 1a of the inspection object 1 can be inspected by repeating the above detection operation while gradually moving the optical path support cylinder 8 in the cylinder axis direction of the inspection object 1 by the linear motor 28. .

  In this embodiment, as the rotating means RM, the electric motor 9 is used as the rotating arm RM, the armature shaft 9a is formed into a hollow cylindrical shape, the fiber holding cylinder 5 is inserted therein, and the optical path support cylinder 8 is directly connected to the armature shaft 9a. Since such a structure is adopted, an interlocking mechanism such as a gear, a pulley, and a friction wheel is not necessary, so that the occurrence of failure and the like can be reduced and the durability can be improved.

  Next, a second embodiment in which a prism 31 is used as the optical path changing means LA in FIG. 4 in place of the reflecting mirror 7 in FIG. The structural members that are substantially the same as those in the embodiment shown in FIGS.

  The prism 31 has a cross section of a right isosceles triangle having a reflection surface 31a having an angle of intersection with the axis 8c of the optical path support cylinder 8 of 45 degrees, and is supported inside the optical path support cylinder 8 by the prism mounting arm 32. Yes. Although not shown, for example, by moving the lens receiver 6a and the prism mounting arm 32 using a known adjusting screw mechanism, the support position and the support angle of the convex lens 6 and the prism 31 with respect to the optical path support tube 8 are set. It can be adjusted freely.

  In this embodiment, the inspection light emitted from the projecting optical fiber 3 is slightly condensed by the convex lens 6 and enters the prism 31, and is totally reflected by the 45 degree reflection surface 31a of the prism 31, and the optical path is changed at a right angle. Then, the light is condensed and projected onto a specific inspection range R on the inner surface 1a of the inspection object 1. The reflected light is returned to the receiving optical fibers 4a and 4b through an optical path opposite to the above. Thus, the prism 31 can also be used as the optical path changing means LA.

  Further, in FIG. 5, a third embodiment in which the optical path changing means LA and the condensing means LC are unified by using the concave mirror 33 is shown as a cutaway plan view of the main part. The structural members that are substantially the same as those in the embodiment shown in FIGS.

  In this embodiment, the concave mirror 33 is supported inside the optical path support cylinder 8 by the concave mirror mounting arm 33a. Then, the inspection light emitted from the projecting optical fiber 3 is reflected by the concave mirror 33 in a right angle direction and condensed, and then condensed and irradiated on a specific inspection range R on the inner surface 1a of the object 1 to be inspected. ing. Then, the reflected light reflected by the inspection range R is reflected again by the concave mirror 33 and returned to the receiving optical fibers 4a and 4b. Also in this embodiment, although not shown in the drawings, for example, by moving the concave mirror mounting arm 32a using a known adjusting screw mechanism, the support position and the support angle of the concave mirror 33 with respect to the optical path support cylinder 8 are set. It can be adjusted freely.

  In this embodiment, by using the concave mirror 33, the optical path changing means LA and the condensing means LC can be constituted by a single member, so that the structure can be simplified.

  In each of the above embodiments, the optical path support cylinder 8 in which the inspection light is internally provided with the optical path changing means LA and the condensing means LC is rotated around the axis 5C of the fiber holding cylinder 5 while rotating outside the outer periphery of the axis 5C. This is a structure for inspecting the inner surface 1a located on the side.

  On the other hand, in the embodiment shown in FIG. 6, the surface inspection apparatus capable of efficiently inspecting the planar surface 42a located in front of the optical path center 41C of the optical path support cylinder 41 while the inspection light swivels and rotates, is an essential part. It is shown in a cutaway plan view. Constituent members that are the same as those shown in FIG.

  In this embodiment, in addition to the convex lens 6 and the reflecting mirror 7, the second stage reflecting mirror 43 is supported by the reflecting mirror mounting arm 43 a inside the optical path support tube 41. The optical path support cylinder 41 is attached to the armature shaft 9a by, for example, screwing in such a manner that the optical path center 41C of the optical path support cylinder 41 coincides with the cylinder core 5C of the fiber holding cylinder 5 at the tip of the armature shaft 9a. Although not shown, for example, by moving the lens receiver 6a and the reflector mounting arms 7a and 43a using a well-known adjusting screw mechanism, the support position of the convex lens 6 and the reflectors 7 and 43 to the optical path support tube 41 is The support angle can be adjusted freely. In particular, by changing the position (interval L) of the second-stage reflecting mirror 43 with respect to the reflecting mirror 7, the rotation diameter of the inspection light with respect to the axis 5C, that is, the position of the inspection range R2 can be freely changed. The optical path support tube 41 has its tip end closed with an end plate 41a, and has a light transmission hole 41b at one location on the end plate 41a.

  In the embodiment of FIG. 6, along with the rotation of the armature shaft 9a of the electric motor 9, the inspection light from the throwing optical fiber 3 turns to the planar surface 42a with a radius L from the axis 5C as illustrated in FIG. The light is sequentially emitted while rotating.

  In other words, the inspection light from the light source 2 is slightly condensed by the convex lens 6 from the projecting optical fiber 3 as shown by the solid line in FIG. 6, and reaches the first-stage reflecting mirror 7, where the optical path is changed at a right angle. A specific inspection of the planar surface 42a of the object 42 to be inspected with the parallel optical axis deviated from the axis of the fiber holding cylinder 5 by reaching the two-stage reflecting mirror 43 where the optical path is further changed at a right angle. The range R2 is irradiated. The reflected light travels in the reverse direction of the optical path, reaches the first-stage reflecting mirror 7 from the second-stage reflecting mirror 43, is condensed by the convex lens 6, and is received by the right and left receiving optical fibers 4 a and 4 b. Light is received as indicated by dotted arrows.

  According to this embodiment, by gradually moving the surface inspection apparatus in parallel with the plane of the inspection object 42, the inspection can be performed with a width corresponding to the diameter of the rotating circle in FIG. The inspection area by the movement can be widened, and the workability can be improved by reducing the number of reciprocating movements of the surface inspection apparatus or the inspection object.

  FIG. 8 shows another embodiment in which a flat glass plate 44 having end faces 44a and 44b parallel to each other is used in place of the first-stage reflecting mirror 7 and the second-stage reflecting mirror 43 in the embodiment of FIG. It is a principal part notch top view shown. The flat glass plate 44 is attached to the optical path support tube 41 by a glass plate attachment arm 44c. The other configuration is the same as that of the embodiment of FIG.

  Similarly to the embodiment of FIG. 6, this embodiment also refracts the inspection light at the parallel end surfaces 44 a and 44 b of the flat glass plate 44, and parallel light decentered from the axis of the fiber holding cylinder 5 by the distance L. The axis can irradiate a specific inspection range R2 of the planar surface 42a of the inspection object 42.

  Then, as the armature shaft 9a of the electric motor 9 rotates, the inspection light from the light projecting optical fiber 3 is sequentially projected while turning with a radius of an interval L from the axis 5C. And the workability can be improved by reducing the number of reciprocating movements of the surface inspection apparatus or the inspection object.

  Although not shown, a rhombus prism may be used instead of the flat glass plate 44. That is, the optical path is changed in a substantially perpendicular direction by the two reflecting surfaces of the rhomboid prism having an angle of 45 degrees with respect to the optical path center 41C of the optical path support cylinder 41, and is decentered by an interval L from the optical path center 41C. You may comprise so that it may concentrate and light-project in specific inspection range R2.

It is a principal part notch top view which shows the test | inspection state by 1st Example of the surface inspection apparatus of this invention. It is an end elevation which shows the fiber holding cylinder in the Example of FIG. It is a block diagram which shows an example of the detection circuit in the Example of FIG. It is a principal part notch top view which shows the 2nd Example which changed the optical path change means of the surface inspection apparatus of this invention. It is a principal part notch top view which shows the 3rd Example which changed the condensing means and the optical path change means of the surface inspection apparatus of this invention. It is a principal part notch top view which shows the 4th Example of the surface inspection apparatus of this invention. It is explanatory drawing which showed typically the locus | trajectory of the inspection light of the Example of FIG. It is a principal part notch top view which shows the 5th Example of the surface inspection apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Test object 1a Internal surface 2 Light source 3 Throw optical fiber 4a, 4b Receiving optical fiber 5 Fiber holding cylinder 5C Axis 6 Convex lens 7 Reflective mirror 31 Prism 33 Concave mirror LC Condensing means LA Optical path changing means RM Rotating means

Claims (7)

A projection optical fiber for projecting inspection light from the light source to the surface of the object to be inspected, and a light receiving optical fiber for receiving the reflected light of the inspection light from the object to be inspected, and the amount of reflected light received by the light receiving optical fiber In a surface inspection apparatus that detects a scratch on the surface of an object to be inspected or a foreign object on the surface by comparing and judging the magnitude of the detected amount,
A plurality of the receiving optical fibers are arranged around the projecting optical fiber, and the projecting optical fiber and the receiving optical fiber are bound to each other and inserted and held in a fiber holding cylinder,
While converging the inspection light emitted from the projecting optical fiber, the path is changed to irradiate the surface of the object to be inspected substantially perpendicularly, and the reflected light is similarly focused while the path is changed to change the receiving optical fiber. The light collecting means and the optical path changing means to be returned to the front of the fiber holding cylinder,
A rotation means for rotating at least the optical path changing means about the axis of the fiber holding cylinder;
The rotating means has a hollow cylindrical output shaft that is rotated by an electric motor, and an optical path support cylinder that is attached to the tip of the output shaft and at least the optical path changing means is attached,
The surface inspection apparatus, wherein the fiber holding cylinder is inserted into the output shaft.   The surface inspection apparatus according to claim 1, wherein the optical path changing unit is a reflecting mirror or a prism, and the condensing unit is a convex lens.   The surface inspection apparatus according to claim 1, wherein the optical path changing unit and the condensing unit are concave mirrors.   The surface inspection apparatus according to claim 1, wherein the optical path changing unit changes the optical path in a direction perpendicular to the axis of the fiber holding cylinder.   The surface inspection apparatus according to claim 1, wherein the optical path changing unit changes the optical path to a position eccentric with respect to an axis of the fiber holding cylinder.   The surface inspection apparatus is for inspecting an inner surface of an object to be inspected, and has means for relatively moving the object in the cylinder axis direction of the object to be inspected. Surface inspection device. The surface inspection apparatus according to any one of claims 1 to 6, wherein the optical path support tube is attached to a distal end portion of the output shaft by screwing.

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