Optical probes and inspection equipment

Abstract

Reduces malfunctions in optical modules caused by collisions. [Solution] The optical probe 10 comprises an optical module 11 configured to irradiate the inner surface of an object to be inspected with an annular beam 20, an imaging device 12 positioned to receive the light reflected from the inner surface of the object to be inspected, and a cover member 32 configured to cover the optical module 11.

Description

Technical Field

[0001] The present invention relates to an optical probe and an inspection apparatus.

Background Art

[0002] Conventionally, an inspection apparatus is known that inspects the inner peripheral surface by obtaining an optical cutting image from an annular beam image obtained by irradiating an annular laser beam onto the inner peripheral surface of an inspection object while moving along the axial direction of the tubular inspection object (see, for example, Patent Document 1).

[0003] In this inspection apparatus, an annular beam that spreads in the circumferential direction radially from a point on its central axis is used in the space inside the inspection object. The annular beam is incident on the inner peripheral surface of the inspection object, and an annular beam image is acquired by a camera arranged on the central axis of the inspection object. By analyzing this annular beam image, information regarding the inner diameter, surface shape, presence or absence of defects on the inner peripheral surface, etc. of the inspection object can be obtained.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the inspection apparatus as described above, during inspection, an optical probe including an optical module that irradiates an annular beam onto the inner peripheral surface of the inspection object is moved to enter the space inside the inspection object. At this time, if the optical module collides with some object, there is a risk of causing a malfunction of the optical module.

[0006] The present invention has been made in view of such a situation, and its object is to provide an optical probe and an inspection apparatus capable of reducing malfunctions of the optical module caused by collisions. [Means for solving the problem]

[0007] To solve the above problems, an optical probe in one aspect of the present invention comprises an optical module configured to irradiate the inner surface of an object to be inspected with an annular beam, an imaging device arranged to receive the light reflected from the inner surface of the object to be inspected, and a cover member configured to cover the optical module.

[0008] Another aspect of the present invention is an inspection apparatus. This inspection apparatus comprises a workpiece mounting section for holding an object to be inspected, the above-mentioned optical probe, a support mechanism for holding the optical probe so as to be movable along the central axis of the object to be inspected, and a control unit for controlling the movement of the optical probe by the support mechanism. The control unit stops the movement of the optical probe when a collision is detected by a collision detection sensor. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an optical probe and inspection apparatus that can reduce malfunctions of optical modules caused by collisions. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view of an inspection apparatus using an optical probe according to an embodiment. [Figure 2] This is a schematic perspective view of the optical probe. [Figure 3] This is a schematic cross-sectional view of the optical probe. [Modes for carrying out the invention]

[0011] In the following, identical or equivalent components and members shown in each drawing will be denoted by the same reference numeral, and redundant explanations will be omitted as appropriate. Furthermore, the dimensions of the members in each drawing will be enlarged or reduced as appropriate for ease of understanding. Additionally, some members that are not important for explaining the embodiment will be omitted from the drawings.

[0012] Figure 1 is a schematic cross-sectional view of an inspection device 100 using an optical probe 10 according to an embodiment. The inspection device 100 inspects the inner surface of an object to be inspected 60 by irradiating it with an annular beam.

[0013] The inspection device 100 comprises a housing 50 and a support plate 51 arranged in the internal space of the housing 50. The housing 50 can move on the floor surface by wheels 53. The internal space of the housing 50 is divided into two spaces, upper and lower, by the support plate 51. The upper space will be called the inspection room 50A, and the lower space will be called the waiting room 50B. In this embodiment, the positional relationship between the inspection room 50A and the waiting room 50B is upper and lower, but this is not necessarily required. For example, they may be arranged side by side horizontally. Alternatively, the upper and lower relationship between the inspection room 50A and the waiting room 50B may be reversed.

[0014] A workpiece mounting section 52 is fixed on a support plate 51, and a tubular object to be inspected, for example, 60 is held on the workpiece mounting section 52. The object to be inspected 60 is fixed in a position where its central axis is parallel to the vertical direction. An opening 54 is provided directly below the internal space of the object to be inspected 60, passing through the support plate 51 and the workpiece mounting section 52 in the vertical direction.

[0015] The inspection device 100 includes an optical probe 10. The optical probe 10 is supported by a support mechanism 18 so as to be movable along the central axis of the object to be inspected 60. The support mechanism 18 is controlled by a control unit 42. In standby mode when no inspection is being performed, the optical probe 10 is waiting in a standby chamber 50B below the object to be inspected 60 (below the support plate 51). During inspection, the optical probe 10 is raised by the support mechanism 18 through the opening 54 and enters the inspection chamber 50A, entering the space inside the object to be inspected 60.

[0016] The optical probe 10 includes an optical module 11, an imaging device 12, and an optical module fixing member 13. The optical module 11 is supported directly above the imaging device 12 by the optical module fixing member 13, and its position relative to the imaging device 12 is fixed.

[0017] Inside the waiting room 50B of the housing 50, a laser light source 15 and a control unit 42 are accommodated. As the laser light source 15, for example, a laser diode that outputs a laser beam with a wavelength within the range of 370 nm or more and 1100 nm or less is used. Laser light is introduced from the laser light source 15 to the optical module 11 via the optical fiber 16. The control unit 42 controls the laser light source 15 and the support mechanism 18 according to commands from the upper controller 40. The image captured by the imaging device 12 is input to the analysis unit 41 of the upper controller 40, and the analysis unit 41 analyzes the image. Based on the analysis result of the image, the inner diameter of the inspection object 60 can be measured.

[0018] Figure 2 is a schematic perspective view of the optical probe 10. The optical probe 10 includes an optical module 11 and an imaging device 12. The optical module 11 includes a collimating lens 11A and a conical mirror 11B. The position of the conical mirror 11B is fixed with respect to the collimating lens 11A by a support member.

[0019] Laser light is guided from the laser light source 15 to the optical module 11 via the optical fiber 16. The laser light output from the output end of the optical fiber 16 is collimated by the collimating lens 11A. In order to reduce the influence on the image captured by the imaging device 12, the optical fiber 16 is preferably covered with a black tube to prevent light reflection.

[0020] The conical mirror 11B is arranged at the position where the collimated light is incident. The conical mirror 11B has a conical reflecting surface. The rotation axis of this conical surface coincides with the optical axis of the collimated light (the optical axis of the collimating lens 11A). The conical mirror 11B reflects the collimated light to generate an annular beam 20 that spreads in the circumferential direction of the inner peripheral surface of the inspection object 60.

[0021] When the apex angle of the conical reflecting surface of the conical mirror 11B is 90°, the annular beam 20 spreads in a disk shape (sheet shape). The inner peripheral surface of the inspection object 60 is a rough surface having irregularities with dimensions equal to or larger than the wavelength of the annular beam 20. When the annular beam 20 is incident on the inner peripheral surface of the inspection object 60, diffuse reflection occurs. The location where diffuse reflection occurs is referred to as a diffuse reflection location 21. The diffuse reflection location 21 is along the intersection line between a plane orthogonal to the central axis of the inspection object 60 and the inner peripheral surface of the inspection object 60. When the inner peripheral surface is a cylindrical surface, the diffuse reflection location 21 has a circular shape. A part of the reflected light 22 diffusely reflected at the diffuse reflection location 21 is incident on the imaging device 12. The imaging device 12 receives the reflected light 22 and generates an image.

[0022] FIG. 3 is a schematic cross-sectional view of the optical probe 10. The optical probe 10 includes an optical module 11 configured to irradiate an annular beam onto the inner peripheral surface of the inspection object 6, and an imaging device 12 disposed to receive the light reflected from the inner peripheral surface of the inspection object 60.

[0023] The optical module 11 includes a collimating lens 11A that collimates the laser light output from the output end of the optical fiber 16, a conical mirror 11B that reflects the collimated light from the collimating lens 11A to generate an annular beam 20 that spreads in the circumferential direction of the inner peripheral surface of the inspection object, and a support member 11C that fixes the collimating lens 11A and the conical mirror 11B at predetermined positions. A plurality of long holes are provided on the side surface of the support member 11C to allow the annular beam 20 from the conical mirror 11B to pass through.

[0024] As described above, during inspection, the optical probe 10 is moved by the support mechanism 18 and enters the space inside the object to be inspected 60. If the object to be inspected 60 is installed misaligned from its predetermined position, the optical module 11 may collide with the object to be inspected. Also, if there is an obstacle in the workpiece installation section 52, the optical module 11 may come into contact with this obstacle. If the support member 11C of the optical module 11 collides with any object in this manner, the optical module fixing member 13 that supports the optical module 11 above the imaging device 12 may bend, and the position and tilt of the annular beam 20 may be shifted. In addition, the optical module fixing member 13 and the support member 11C are fastened together with screws, and these screws may become misaligned. Furthermore, the support member 11C may be deformed or damaged, disrupting the positional relationship between the collimating lens 11A and the conical mirror 11B, and causing the position and tilt of the annular beam 20 to be shifted. The support member 11C is provided with multiple elongated holes for the annular beam 20 to pass through, and the upper and lower parts of the support member 11C are connected by thin support columns placed between the elongated holes; therefore, the strength of the support member 11C is not very high.

[0025] Therefore, the optical probe 10 according to this embodiment includes a cover member 32 configured to cover the optical module 11. The cover member 32 is a substantially cylindrical member formed to cover the support member 11C of the optical module 11. By providing such a cover member 32, it is possible to prevent objects from directly colliding with the optical module 11 and to prevent misalignment or tilt of the annular beam 20. An elongated hole 32a is provided on the side surface of the cover member 32 for the passage of the annular beam 20, and a through hole 32b is provided on the bottom surface of the cover member 32 for the passage of the optical fiber 16.

[0026] The optical probe 10 according to this embodiment further includes a first collision detection sensor 34 for detecting collisions of objects with the cover member 32. In this embodiment, the first collision detection sensor 34 is provided on the upper surface of the cover member 32. The first collision detection sensor 34 is a contact switch comprising two contact plates 35 and 36 arranged at a predetermined distance apart, an elastic body 37 such as sponge rubber provided between the contact plates 35 and 36, and electric wires 38 and 39 connected to the contact plates 35 and 36. The electric wires 38 and 39 are connected to the control unit 42. When the contact plate 35 comes into contact with an object, the elastic body 37 deforms, causing the contact plates 35 and 36 to come into contact and short-circuit, allowing the control unit 42 to detect contact between the object and the cover member 32. To reduce the impact on the image captured by the imaging device 12, it is preferable that the surfaces of the electric wires 38 and 39 are painted black to prevent light reflection.

[0027] The control unit 42 stops the movement of the optical probe 10 when a collision is detected by the first collision detection sensor 34. This prevents a situation where a force exceeding the sensitivity of the first collision detection sensor 34 is directly applied to the optical probe 10, thereby preventing misalignment or tilt of the annular beam 20.

[0028] As shown in Figure 3, the optical probe 10 further includes a base portion 44 that houses the imaging device 12, an optical module fixing member 13 erected on the base portion 44 to fix the position of the optical module 11 relative to the imaging device 12, and a second collision detection sensor 45 provided on the base portion 44. The optical module fixing member 13 is configured to widen from the optical module 11 side toward the imaging device 12 side. The base portion 44 is formed to be wider than the optical module 11.

[0029] The second collision detection sensor 45 is a ring-shaped setting switch and comprises two contact plates 46 and 47 arranged at a predetermined distance apart, an elastic body 48 such as sponge rubber provided between the contact plates 46 and 47, and electric wires 55 and 56 connected to the contact plates 46 and 47. The electric wires 55 and 56 are connected to the control unit 42. When the contact plate 46 comes into contact with an object, the elastic body 48 deforms, causing the contact plates 46 and 47 to come into contact and short-circuit, allowing the control unit 42 to detect contact between the object and the base portion 44.

[0030] In the optical probe 10 according to this embodiment, when the optical probe 10 moves, even if the optical module 11 does not come into contact with an object, the base portion 44, which is wider than the optical module 11, may come into contact with the object. If the base portion 44 comes into contact with an object, the imaging device 12 may be misaligned, potentially causing measurement errors. Therefore, the control unit 42 stops the movement of the optical probe 10 when a collision is detected by the second collision detection sensor 45. This prevents a situation where a force exceeding the sensitivity of the second collision detection sensor 45 is directly applied to the base portion 44, thereby preventing the imaging device 12 from being misaligned.

[0031] In the above-described embodiment, contact sensors such as contact switches were used as the first collision detection sensor 34 and the second collision detection sensor 45. However, the first collision detection sensor 34 and the second collision detection sensor 45 are not limited to contact sensors and may be non-contact sensors such as optical sensors or magnetic sensors. Alternatively, a collision may be detected by detecting a change in the amount of current flowing through the motor used to move the optical probe 10.

[0032] Any combination of the embodiments and modifications described above is also useful as an embodiment of the present invention. The new embodiments resulting from these combinations possess the effects of both the combined embodiments and modifications. [Explanation of Symbols]

[0033] 10 Optical probe, 11 Optical module, 11A Collimating lens, 11B Conical mirror, 12 Imaging device, 13 Optical module fixing member, 15 Laser light source, 16 Optical fiber, 18 Support mechanism, 20 Annular beam, 21 Diffuse reflection point, 24 Tip portion, 25 Reflecting surface, 26 Collimated light, 30 Reflected beam, 32 Cover member, 34 First collision detection sensor, 40 Higher-level controller, 41 Analysis unit, 42 Control unit, 44 Base unit, 45 Second collision detection sensor, 50 Housing, 50A Inspection room, 50B Waiting room, 51 Support plate, 52 Workpiece installation unit, 53 Wheel, 54 Aperture, 60 Object to be inspected, 100 Inspection device.

Claims

1. A light module configured to irradiate the inner surface of an object to be inspected with an annular beam, An imaging device positioned to receive light reflected from the inner surface of the object to be inspected, A cover member configured to cover the aforementioned optical module, An optical probe characterized by having the following features.

2. The optical probe according to claim 1, further comprising a collision detection sensor for detecting an object colliding with the cover member.

3. A base portion that houses the aforementioned imaging device inside, An optical module fixing member erected on the base portion for fixing the position of the optical module relative to the imaging device, A second collision detection sensor is provided on the base portion, The optical probe according to claim 2, characterized by comprising:

4. A workpiece mounting section that holds the object to be inspected, The optical probe described in claim 2, A support mechanism that holds the optical probe so as to be movable along the central axis of the object to be inspected, A control unit that controls the movement of the optical probe by the support mechanism, Equipped with, The inspection apparatus is characterized in that the control unit stops the movement of the optical probe when a collision is detected by the collision detection sensor.

5. A workpiece mounting section that holds the object to be inspected, The optical probe according to claim 3, A support mechanism that holds the optical probe so as to be movable along the central axis of the object to be inspected, A control unit that controls the movement of the optical probe by the support mechanism, Equipped with, The inspection apparatus is characterized in that the control unit stops the movement of the optical probe when a collision is detected by the collision detection sensor or the second collision detection sensor.

Images