Interference imaging device

Abstract

The interference image camera device includes a first optical component (21) and a second optical component (22), and has: a first part (8) that allows the first light beam (7) to pass through and changes the direction of the outgoing light with respect to the incident light; and a second part (10) that changes the phase of the second light beam (9) relative to the first light beam (7).

Description

Technical Field

[0001] The invention relates to an interference image pickup device. Background Art

[0002] Conventionally, there are known interference image pickup devices. For example, Japanese Patent Application Laid-Open No. 2012-42218 discloses an interference image pickup device.

[0003] The above-mentioned Japanese Patent Gazette No. 2012-42218 discloses a defect inspection device (interference image camera device), which has a light source for irradiating illumination light to an object, an optical system for interfering transmitted light of the illumination light arriving from different positions of the object, and an imaging element for capturing the intensity pattern of the transmitted light after interference.

[0004] The optical system of the defect inspection device of the above-mentioned Japanese Patent Publication No. 2012-42218 uses a semi-transparent and semi-reflective mirror to split the light coming from the object into two light beams (a first light beam and a second light beam). Thus, for the first light beam and the second light beam separated in space, their phases and directions are relatively changed by a phase shifter and a deflector, and then the two light beams are combined by a semi-transparent and semi-reflective mirror, and interfere on the imaging element to obtain an image. At this time, in the light reaching one point on the imaging element, the light contained in the first light beam and the light contained in the second light beam arrive from points at different positions of the object. Then, defects are inspected based on the optical interference image acquired by the imaging element.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-42218 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, in the defect inspection device (interference image pickup device) of the above-mentioned Japanese Patent Application Publication No. 2012-42218, a semi-transparent mirror is used to separate the light coming from the object in two directions, and after phase shifting and deflecting, the separated light is interfered by another semi-transparent mirror. Therefore, it is necessary to separately provide a semi-transparent mirror for separating the transmitted light, a phase shift unit, a deflector, and a semi-transparent mirror for interfering the separated light. As a result, four optical components need to be provided, so there is a problem that the number of components increases and the defect inspection device becomes large-scale.

[0010] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an interference image pickup device that can reduce the number of components and suppress an increase in size of the device.

[0011] Solutions for solving problems

[0012] In order to achieve the above-mentioned purpose, the interference image camera device of the first aspect of the present invention comprises: an irradiation unit, which irradiates the measurement area of ​​the object with irradiation light from a laser light source; an optical component, which divides the irradiation light reflected or transmitted from points or areas at different positions of the object into a first light beam and a second light beam and transmits the irradiation light through the optical component, and the optical component causes the transmitted first light beam and the second light beam to interfere; a camera unit, which captures the intensity pattern of the first light beam and the intensity pattern of the second light beam after passing through the optical component and interfering; and a rotation mechanism, which rotates at least a part of the optical component, the optical component includes a first optical component, a second optical component arranged opposite to the first optical component, and a third optical component arranged opposite to the first optical component on a side opposite to a side where the second optical component is provided, the rotation mechanism is configured to change the relative angle between the first light beam and the second light beam by rotating at least one of the first optical component and the third optical component, and the first optical component and the second optical component are configured to allow the second light beam to pass through and change the phase of the second light beam.

[0013] In the interference image camera device of the first aspect of the present invention, as described above, the interference image camera device has: an optical member, the irradiation light reflected or transmitted from points or regions at different positions of the object is divided into a first light beam and a second light beam and passes through the optical member, and the optical member causes the transmitted first light beam and the second light beam to interfere; and a rotation mechanism, which rotates at least a part of the optical member, the optical member includes a first optical member, a second optical member and a third optical member, and the rotation mechanism rotates at least one of the first optical member and the third optical member. Thus, it is configured to change the relative angle between the first light beam and the second light beam, and the first optical member and the second optical member are configured to allow the second light beam to pass through and change the phase of the second light beam. Therefore, it is not necessary to separate the irradiation light in two directions, and therefore it is not necessary to set an optical member (semi-transparent and semi-reflective mirror) for separating the light and an optical member (semi-transparent and semi-reflective mirror) for interfering the separated light. In addition, by setting the first optical member and the second optical member, it is not necessary to set a phase shifter. Furthermore, due to the rotation mechanism, it is not necessary to set a deflector. As a result, the first optical member, the second optical member, and the rotation mechanism are provided to replace the phase shifter and the deflector, but it is not necessary to provide an optical member (semi-transparent mirror) for separating light and an optical member (semi-transparent mirror) for interfering the separated light. Therefore, the number of components can be reduced and the size of the device can be suppressed.

[0014] The interference image camera device of the second aspect of the present invention comprises: an irradiation unit, which irradiates the measurement area of ​​the object with irradiation light from a laser light source; an optical component, which divides the irradiation light reflected or transmitted from points or areas at different positions of the object into a first light beam and a second light beam and passes through the optical component, and the optical component causes the transmitted first light beam and the second light beam to interfere; a camera unit, which captures the intensity pattern of the first light beam and the intensity pattern of the second light beam after passing through the optical component and interfering, the optical component includes a first optical component and a second optical component arranged relative to each other, the optical component comprising: a first part, which is composed of at least one of the first optical component and the second optical component, and allows the first light beam to pass through and changes the direction of the outgoing light relative to the direction of the incident light; and a second part, which is composed of the first optical component and the second optical component, and allows the second light beam to pass through and changes the phase of the second light beam relative to the first light beam.

[0015] In the interference image pickup device of the second aspect of the present invention, as described above, the interference image pickup device comprises: an optical member that transmits irradiation light reflected from points or regions at different positions of an object and causes the transmitted first light beam and second light beam to interfere; and an imaging unit that captures the intensity pattern of the first light beam and the intensity pattern of the second light beam after the interference through the optical member, the optical member comprises a first optical member and a second optical member arranged opposite to each other, the optical member comprises: a first part that is composed of at least one of the first optical member and the second optical member, transmits the first light beam and changes the direction of the outgoing light relative to the direction of the incident light; and a second part that is composed of the first optical member and the second optical member, transmits the second light beam and changes the phase of the second light beam relative to the first light beam. Thus, it is not necessary to separate the irradiation light in two directions, and therefore it is not necessary to provide an optical member (semi-transparent mirror) for separating the light and an optical member (semi-transparent mirror) for interfering the separated light. In addition, by providing the first optical component and the second optical component, there is no need to provide a phase shifter and a deflector for changing the direction of the irradiated light, respectively. As a result, the first optical component and the second optical component are provided to replace the phase shifter and the deflector, but there is no need to provide an optical component (semi-transparent and semi-reflective mirror) for separating the light and an optical component (semi-transparent and semi-reflective mirror) for interfering the separated light. Therefore, the number of components can be reduced, and the large-scale device can be suppressed. In addition, since there is no need to provide an optical component for separating and interfering the irradiated light, the loss of light due to reflection and transmission at the optical component can be suppressed. In addition, the above-mentioned optical component can be used to interfere with the irradiated light reflected from points or areas at different positions of the object. Thus, for example, defects can be inspected based on an optical interference image obtained by interfering the irradiated light reflected from a point on the object and an area in its surrounding range, thereby reducing the directional dependence of the detection sensitivity of the defect.

[0016] In the interference image camera device of the second aspect, it is preferred that at least one of the first optical component and the second optical component includes a composite lens pair formed by integrating the first part and the second part. If so configured, the composite lens pair formed by integrating the first part and the second part can have two functions: a phase shifting function for changing the phase of the second light beam and a deflection function for changing the forward direction of the first light beam. As a result, the forward direction of the first light beam can be changed and the phase of the second light beam can be shifted only by using the composite lens pair. Therefore, compared with the case where a semi-transparent and semi-reflective mirror, a deflection unit and a phase shifting unit are provided separately, the number of components can be reduced and the enlargement of the device can be suppressed.

[0017] In the interference image capturing device of the second aspect, it is preferred that, in the first optical member and the second optical member, the first portion is disposed on the outside and the second portion is disposed on the inside. With such a configuration, the first light beam deflected by the first portion disposed on the outside and the second light beam phase-shifted by the second portion disposed on the inside can interfere at the position of the imaging unit.

[0018] In the interference image pickup device of the second aspect, it is preferred that the optical member is provided with a light shielding member at a boundary portion adjacent to the first portion and the second portion. With such a configuration, it is possible to suppress the following situations: the second light beam that has passed through the second portion of the first optical member passes through the portion of the second optical member that is opposite to the first portion, and the first light beam that has passed through the first portion of the first optical member passes through the second portion of the second optical member. Thus, even if the optical path of the first light beam and the optical path of the second light beam are not separated, it is possible to suppress the first light beam and the second light beam from entering an erroneous optical path.

[0019] In the interference image camera device of the second aspect, the optical member is preferably arranged close to the position of the aperture stop of the optical system that causes the irradiation light reflected from the object to enter the camera unit. Here, the position of the aperture stop of the optical system refers to the position where the irradiation light reflected from each position in the measurement area of ​​the object and incident on the camera unit passes through approximately the same area. In addition, close means both the case of contact with the aperture stop and the case of separation from the aperture stop. If configured in this way, the irradiation light reflected from each position in the measurement area and incident on the camera unit passes through approximately the same area in the optical member, so the ratio of the amount of light passing through the first part of the optical member and the amount of light passing through the second part will not differ greatly depending on the position in the measurement area. In addition, in the case where the first part has a function of generating different deflections depending on the position of transmission, the characteristics of the deflection will not change greatly depending on the position in the measurement area.

[0020] In the interference image pickup device of the second aspect, it is preferred that, in the optical member, the annular first portion surrounds the circular second portion and is arranged adjacent to the second portion when viewed from the incident direction of the irradiation light. With such a configuration, the first portion for changing the advancing direction of the first light beam and the second portion for shifting the phase of the second light beam are adjacent to each other, and therefore, compared with a conventional device in which a phase shifting unit for shifting the phase and a deflecting unit for changing the advancing direction of the irradiation light are separately provided, the space can be reduced. Thus, it is also possible to suppress the enlargement of the device.

[0021] In the interference image pickup device of the second aspect, it is preferred that the surface of the first part of the first optical member that is opposite to the second optical member, and the surfaces of the second part of the first optical member and the second part of the second optical member that are opposite to each other are set to be inclined relative to the direction orthogonal to the incident direction of the irradiated light, and the surfaces of the second part of the first optical member and the second part of the second optical member that are opposite to each other are set approximately parallel to each other. If it is configured in this way, the light that has passed through the first part passes through the second optical member after being refracted by the first part of the first optical member, so that the advancing direction of the first light beam can be changed. On the other hand, even if the light that has passed through the second part is refracted due to the inclination of the second part of the first optical member, the second part of the second optical member is inclined in the same manner as the second part of the first optical member, so that the second light beam is further refracted when passing through the second optical member and returns to the original direction. Therefore, the advancing direction of the second light beam can be transmitted without changing it. In addition, in this structure, by moving the second optical member in a direction perpendicular to the advancing direction of the second light beam, the optical path length of the second light beam passing through the second portion can be easily made longer than the optical path length of the first light beam passing through the first portion. As a result, the phase difference between the first light beam passing through the first portion and entering the imaging unit and the second light beam passing through the second portion and entering the imaging unit can be easily offset (shifted) according to the difference in optical path lengths.

[0022] In the interference image pickup device according to the second aspect, preferably, in the first optical member, the second portion is formed into a circular shape when viewed from the incident direction of the irradiated light, and the first portion is formed into a side shape of a cone with the head portion removed, and the top end is connected to the second portion. With such a configuration, the first light beam deflected in a circular shape can be incident on the periphery of the second light beam in the pickup section.

[0023] In the interference image pickup device of the second aspect, it is preferred that, in the first optical member, the first portion is formed into a side shape of a polygonal pyramid with the head removed when viewed from the incident direction of the irradiated light. If so configured, the deflected first light beam can be incident on the periphery of the second light beam.

[0024] In the interference image camera device of the second aspect, it is preferred that the optical member includes a third optical member arranged opposite to the first optical member, the surface of the second part of the first optical member opposite to the second optical member, and the surface of the second part of the second optical member opposite to the first optical member are inclined relative to a first direction orthogonal to the incident direction of the irradiated light, and the surface of the second part of the first optical member opposite to the third optical member, and the surface of the second part of the third optical member opposite to the first optical member are inclined relative to a second direction orthogonal to the incident direction of the irradiated light and intersecting the first direction, and the interference image camera device further has a rotation mechanism that changes the relative angle between the first direction and the second direction by rotating the third optical member. If so configured, the relative angle between the first direction and the second direction can be changed by rotating the third optical member using the rotation mechanism, thereby changing the angle of the surface of the optical member on which the second light beam is incident or emitted relative to the irradiation direction, and thus changing the angle of refraction of the second light beam. Therefore, the position at which the second light beam is incident on the imaging unit can be adjusted, and thus the relative positions at which the first and second light beams are incident on the imaging unit can be adjusted. As a result, even when there are manufacturing errors in the optical components, the relative positions of the first and second light beams can be adjusted to suppress the occurrence of individual differences in the interference image capturing device.

[0025] In this case, it is preferred that the rotating mechanism has a first rotating mechanism that rotates the first optical member and the third optical member integrally with respect to the second optical member. If so configured, the first optical member and the third optical member integrally rotate, so that the relative position of the second optical member and the first optical member can be changed without changing the relative position of the first optical member and the third optical member. Thus, the angle of refraction of the second light beam relative to the first direction can be adjusted without changing the angle of refraction of the second light beam relative to the second direction.

[0026] In the interference image capturing device having the above-mentioned first rotating mechanism, it is preferred that the rotating mechanism has a second rotating mechanism in addition to the first rotating mechanism, and the second rotating mechanism rotates the third optical member relative to the first optical member. If so configured, the first rotating mechanism can be used to change the relative position of the second optical member and the first optical member, and the second rotating mechanism can be used to change the relative position of the first optical member and the third optical member. Thus, in addition to being able to adjust the angle of refraction of the second light beam relative to the first direction, it is also possible to adjust the angle of refraction of the second light beam relative to the second direction.

[0027] In the interference image capturing device in which the optical member includes the third optical member, it is preferred that the second optical member, the first optical member, and the third optical member are arranged in order from the incident direction of the irradiation light. If so configured, the direction of the irradiation light whose phase is changed by the second optical member and the first optical member can be changed, and therefore, the relative position of the irradiation light whose phase is changed and the irradiation light deflected by the second optical member or the first optical member can be adjusted.

[0028] Effects of the Invention

[0029] As described above, according to the present invention, it is possible to provide an interference image capturing device that can reduce the number of components and suppress an increase in size of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a block diagram showing the configuration of the interference image capturing device according to the first to third embodiments.

[0031] Figure 2 This is a diagram showing an example of the first optical member and the second optical member according to the first embodiment.

[0032] Figure 3 It is a diagram for explaining the traveling direction of the irradiation light which passes through the first optical member and the second optical member in the first embodiment.

[0033] Figure 4 It is a diagram showing the movement of the second optical member in the first embodiment. Figure 4 (A) is a diagram showing the positions of the first optical member and the second optical member before the movement. Figure 4 (B) is a diagram showing the positions of the first optical member and the second optical member after the movement.

[0034] Figure 5 This is a diagram showing an example of the shapes of the first light beam and the second light beam incident on the imaging element according to the first embodiment.

[0035] Figure 6 This is a diagram showing an example of the first optical member and the second optical member according to the second embodiment.

[0036] Figure 7 It is a diagram for explaining the traveling direction of the irradiation light which passes through the first optical member and the second optical member in the second embodiment.

[0037] Figure 8 This is a diagram showing an example of the shapes of the first light beam and the second light beam incident on the imaging element according to the second embodiment.

[0038] Fig. 9This is a diagram showing another example of the shapes of the first light beam and the second light beam incident on the imaging element according to the second embodiment.

[0039] Fig.10 This is a diagram showing an example of the first optical member and the second optical member according to the third embodiment.

[0040] Fig.11 It is a diagram for explaining the traveling direction of irradiation light that has passed through the first optical member and the second optical member in the third embodiment.

[0041] Fig.12 This is a diagram showing an example of the shapes of the first light beam and the second light beam incident on the imaging element according to the third embodiment.

[0042] Fig.13 1 is a diagram showing an example of a first optical member and a second optical member according to a fourth embodiment. Fig.13 (a) is a diagram showing the first optical member, the second optical member, and the third optical member as viewed from the front, Fig.13 (b) is a diagram of the first optical member and the third optical member as viewed from the side.

[0043] Fig.14 1 is a diagram showing a rotating mechanism according to a fourth embodiment. Fig.14 (a) is a diagram showing the state before rotation, Fig.14 (b) is a diagram showing a state in which the first optical member and the third optical member are rotated. Fig.14 (c) is a diagram showing a state where only the third optical member is rotated.

[0044] Fig.15 It is a diagram showing the direction in which irradiated light is refracted when the optical member is rotated.

[0045] Fig.16 It is a diagram showing a trajectory drawn by the irradiation light when the first rotating mechanism and the second rotating mechanism are rotated.

[0046] Fig.17 is a diagram showing a change in position of the second light beam when the first rotating mechanism and the second rotating mechanism are rotated. Fig.17 (a) is a diagram showing a state before the first rotating mechanism and the second rotating mechanism are rotated, Fig.17 (b) is a diagram showing a state after the first rotating mechanism is rotated, Fig.17 (c) is a diagram showing a state after the second rotating mechanism is rotated.

[0047] Fig.18 2 is a diagram showing a first optical member, a second optical member, and a third optical member according to a fifth embodiment. Fig.18(a) is a diagram showing a state before the third optical member is rotated, Fig.18 (b) is a diagram showing a state where the third optical member is rotated by the second rotating mechanism.

[0048] Fig.19 This is a side view showing a state in which the first optical member is rotated by the first rotating mechanism.

[0049] Fig. 20 is a diagram for explaining the deflection of the first light beam in the fifth embodiment. Fig. 20 (a) is the image before deflection, Fig. 20 (b) is the image after deflection.

[0050] Fig.21 It is a diagram showing an example of the shapes of the first light beam and the second light beam incident on the imaging element of the modification. DETAILED DESCRIPTION

[0051] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0052] (Structure of displacement measuring device)

[0053] Reference Figure 1 to Figure 5 , the structure of the displacement measuring device 100 of the first embodiment is described. In this embodiment, the case where the displacement measuring device 100 is used for defect inspection is described as an example. In addition, the displacement measuring device 100 is an example of the "interference image pickup device" in the claims.

[0054] like Figure 1 As shown, the displacement measuring device 100 of the first embodiment includes an irradiation unit 1, an optical member 2, and an imaging element 3. The imaging element 3 is an example of an "imaging unit" in the claims. The displacement measuring device 100 also includes a control unit 4.

[0055] The irradiation unit 1 is connected to the signal generator 5 via a cable. The irradiation unit 1 irradiates irradiation light to the measurement area 61 of the object 6. The irradiation unit 1 includes a laser light source and an illumination light lens (not shown). The illumination light lens diffusely irradiates the irradiation light irradiated from the laser light source to the entire measurement area 61 on the surface of the object 6. Here, the first light beam 7 and the second light beam 9 are irradiation lights reflected from points or areas at different positions of the object 6, and refer to light beams that are spatially separated by the first part 8 and the second part 10 of the optical component 2, respectively. Figure 1 In FIG. 1 , the first light beam 7 and the second light beam 9 are shown with different hatching lines.

[0056] like Figure 2As shown, the optical component 2 includes a first optical component 21 and a second optical component 22 arranged opposite to each other. The first optical component 21 includes a composite lens pair formed by integrating a first portion 8 and a second portion 10. The optical component 2 includes: a first portion 8, which is composed of at least one of the first optical component 21 and the second optical component 22, and allows the first light beam 7 to pass through and changes the direction of the outgoing light relative to the direction of the incident light; and a second portion 10, which is composed of the first optical component 21 and the second optical component 22, and allows the second light beam 9 to pass through and changes the phase of the second light beam 9 relative to the first light beam 7.

[0057] In the first embodiment, the first portion 8 is provided on the outside and the second portion 10 is provided on the inside. In addition, the annular first portion 8 is disposed adjacent to the circular second portion 10 so as to surround the circular second portion 10 when viewed from the incident direction of the irradiation light.

[0058] In the first embodiment, the first optical member 21 and the second optical member 22 have a convex shape in which the thickness of the second portion 10 is greater than the thickness of the first portion 8 .

[0059] The surface of the first portion 8 of the first optical member 21 that faces the second optical member 22 is set to be inclined relative to the direction (X direction) perpendicular to the incident direction of the irradiation light. Therefore, the irradiation light (first light beam 7) that has passed through the first optical member 21 is refracted at the boundary between the first optical member 21 and the air, and enters the second optical member 22. Then, it is further refracted at the boundary between the second optical member 22 and the air, passes through the second optical member 22, and reaches the imaging element 3. As a result, the first light beam 7 after the irradiation light is deflected can be irradiated.

[0060] The opposing surfaces of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 are set to be inclined relative to the direction (X direction) orthogonal to the incident direction of the irradiation light. In addition, the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 are arranged approximately in parallel. Therefore, the irradiation light (second light beam 9) passes through the second portion 10 of the first optical member 21 and is refracted at the boundary between the first optical member 21 and the air. Then, the irradiation light is refracted to the opposite side at the boundary between the second optical member 22 and the air, and returns in the same direction as when it was incident on the second portion 10 of the first optical member 21. That is, as a result, the irradiation light goes straight through the first optical member 21 and the second optical member 22. Then, the second light beam 9 that has passed through the second portion 10 reaches the imaging element 3.

[0061] The second portion 10 of the first optical member 21 and the opposing surface of the second portion 10 of the second optical member 22 are set to be inclined with respect to the direction (X direction) perpendicular to the incident direction of the irradiated light, so that if the second optical member 22 is moved in the direction perpendicular to the advancing direction of the second light beam 9, the optical path length of the second light beam 9 passing through the second portion 10 can be easily made longer than the optical path length of the first light beam 7 passing through the first portion 8. In addition, based on the difference in optical path length, the phase difference between the first light beam 7 passing through the first portion 8 and incident on the imaging element 3 and the second light beam 9 passing through the second portion 10 and incident on the imaging element 3 can be easily offset (shifted).

[0062] like Figure 4 As shown in FIG. 1 , the second optical member 22 is moved by the actuator 11 in a direction (X direction) intersecting the direction (Z direction) in which the light travels. Therefore, the sum of the thicknesses of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 changes. Specifically, Figure 4 Before the movement shown in (A), the length of a portion of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 facing each other in the Z direction is the total length of the thickness L1 and L2. Figure 4 After the movement shown in (B), the length in the Z direction of a certain portion of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22, that is, the thickness becomes the thickness of the total length of L1 and L3. By changing the thickness in this way, the optical path length changes, and therefore, the phase shift of the second light beam 9 can be changed.

[0063] The optical component 2 is configured to interfere with the first light beam 7 and the second light beam 9 reflected at different positions of the object 6. The first light beam 7 and the second light beam 9 are incident on the first optical component 21 approximately in parallel, but the first light beam 7 is deflected at the first portion 8 so that the first light beam 7 and the second light beam 9 arrive at the same position of the imaging element 3, and the first light beam 7 and the second light beam 9 interfere with each other.

[0064] A light shielding member 12 is provided at a boundary portion adjacent to the first portion 8 and the second portion 10 of the first optical member 21. The light shielding member 12 is annular and can inhibit the first light beam 7 reflected from the object 6 from entering the second portion 10 of the second optical member 22, and can inhibit the second light beam 9 from entering the portion of the second optical member 22 that is opposite to the first portion 8 of the first optical member 21.

[0065] like Figure 1As shown in FIG. 1 , the optical member 2 is arranged at a position close to the aperture stop 13. Therefore, light reflected at different positions of the measurement area 61 of the object 6 passes through substantially the same area of ​​the optical member 2 and enters the imaging element 3. In addition, it is preferable that the light reflected at each position in the measurement area enters the aperture stop 13 at an angle as close to parallel as possible. The optical member 2 may be in contact with the aperture stop 13 or may be separated therefrom.

[0066] like Figure 1 As shown, the imaging lens 14 is disposed between the optical member 2 and the imaging element 3, and converges the first light beam 7 and the second light beam 9 that have passed through the optical member 2. The irradiation lights reflected from the measurement area 61 are incident on the first portion 8 and the second portion 10, respectively, and are incident on the imaging element 3 after being deflected and phase-shifted.

[0067] The imaging element 3 includes, for example, a CMOS image sensor or a CCD image sensor, etc. The imaging element 3 is configured to capture the intensity pattern of the first light beam 7 and the intensity pattern of the second light beam 9. The imaging element 3 causes the first light beam 7 and the second light beam 9 that have passed through the optical member 2 to interfere with each other and perform measurement.

[0068] like Figure 3 As shown in the first embodiment, the first portion 8 and the second portion 10 are inclined at the same angle on the surface of the first optical member 21 facing the second optical member 22. Therefore, the plurality of second light beams 9 passing through the second portion 10 are all refracted at the same angle, so that the second light beams 9 advance straight and the first light beam 7 advances deflected relative to the second light beams 9. Figure 5 As shown in FIG. 1 , in the imaging element 3, the first light beam 7 and the second light beam 9 are incident on the same imaging element 3. Figure 5 In FIG. 1 , the first light beam 7 and the second light beam 9 are shown overlapped.

[0069] The control unit 4 controls the actuator 11 to move the second optical member 22. The movement of the second optical member 22 changes the optical path formed by the first optical member 21 and the second optical member 22, and changes the phase of the transmitted second light beam 9 by changing the optical path length. For example, the actuator 11 moves the first optical member 21 in the X direction within a range of 10 μm. As a result, the phase difference between the first light beam 7 and the second light beam 9 reflected at different positions changes.

[0070] The signal generator 5 of the displacement measuring device 100 of the first embodiment is connected to a vibrator 15 via a cable, and the vibrator 15 is arranged to contact with the object 6 and excite the object 6 to vibrate with sound waves. Specifically, the vibrator 15 is arranged to contact with the object 6, and converts the AC signal from the signal generator 5 into mechanical vibration, thereby exciting the object 6 to vibrate.

[0071] The control unit 4 controls the vibration of the vibrator 15 and the irradiation time of the irradiation light of the irradiation unit 1 via the signal generator 5, and changes the phase shift amount while capturing images. The phase shift amount is changed by λ / 4 each time, and 32 images of irradiation time j (j=0 to 7) and 5 images of the light off before and after each phase shift amount (0, λ / 4, λ / 2, 3λ / 4) are captured, a total of 37 images. In addition, λ is the wavelength of the irradiation light.

[0072] The control unit 4 processes the detection signals from each detection element through the following steps to obtain a dynamic image representing the state of vibration. The control unit 4 measures the spatial distribution of the physical quantity that periodically changes due to the propagation of the vibration of the object 6 based on the reflected light after interference captured by the imaging element 3. For example, the control unit 4 generates a dynamic image related to the propagation of the vibration of the object 6 based on the reflected light after interference captured by the imaging element 3.

[0073] The control unit 4 calculates the optical phase (the phase difference between the two optical paths when the phase shift is zero) Φj using equation (1) based on the brightness values ​​Ij0~Ij3 of images (every 4 images) with the same irradiation time j (j=0~7) but a phase shift difference of λ / 4.

[0074] Φj=-arctan{(Ij3-Ij1) / (Ij2-Ij0)}......(1)

[0075] Furthermore, the control unit 4 performs sinusoidal approximation on the optical phase Φj by the least square method, and obtains the approximation coefficients A, θ, and C in the equation (2).

[0076] Φj=Acos(θ+jπ / 4)+C=Bexp(jπ / 4)+C……(2)

[0077] Here, B is the complex amplitude, which is expressed as in equation (3).

[0078] B=Aexp(iθ): complex amplitude...(3)

[0079] In addition, the control unit 4 constructs and outputs a dynamic image (30 frames to 60 frames) of the light phase change at each phase moment ξ (0≤ξ<2π) of the vibration based on the approximate formula obtained by removing the constant term C from formula (2). In addition, in the above process, in order to remove noise, a spatial filter is appropriately applied to the complex amplitude B. In addition, the step size of the phase shift amount and the irradiation time (λ / 4 and T / 8 respectively in the above example, where T is the period of the vibration) are not limited to this. In this case, the formula becomes a different formula from the above formulas (1) to (3).

[0080] The control unit 4 applies a spatial filter to detect a discontinuous region of the vibration state from the above-mentioned dynamic image as a defective portion of the object 6. That is, the control unit 4 extracts the discontinuous portion of the vibration based on the spatial distribution of the physical quantity. In the case where the shape of the object 6 itself includes concavities and convexities, there is a case where the discontinuity of the vibration state also occurs at the boundary between the flat portion and the concave-convex portion. The control unit 4 may also be configured to detect the defective portion while taking into account the shape information of the object 6, so as to avoid detecting the above-mentioned situation as a defect.

[0081] (Effects of the First Embodiment)

[0082] In this embodiment, the following effects can be obtained.

[0083] In the first embodiment, as described above, the displacement measuring device 100 in the first embodiment includes the optical member 2, the irradiation light reflected or transmitted from points or regions at different positions of the object 6 is divided into the first light beam 7 and the second light beam 9 and passes through the optical member 2, the optical member 2 causes the transmitted first light beam 7 and the second light beam 9 to interfere with each other, the optical member 2 includes the first optical member 21 and the second optical member 22 arranged opposite to each other, and the optical member 2 includes: the first portion 8, which is composed of at least one of the first optical member 21 and the second optical member 22, and transmits the first light beam 7 and changes the direction of the outgoing light relative to the direction of the incident light; and the second portion 10, which is composed of the first optical member 21 and the second optical member 22, and transmits the second light beam 9 and changes the phase of the second light beam 9 relative to the first light beam 7. As a result, it is not necessary to separate the first light beam 7 and the second light beam 9 in two directions, and therefore, it is not necessary to provide an optical member (half mirror) for separating the light and an optical member (half mirror) for interfering the separated light. In addition, by providing the first optical component 21 and the second optical component 22, there is no need to provide a phase shifter and a deflector for changing the direction of the irradiated light, respectively. As a result, the first optical component 21 and the second optical component 22 are provided instead of the phase shifter and the deflector, but there is no need to provide an optical component (semi-transparent and semi-reflective mirror) for separating the light and an optical component (semi-transparent and semi-reflective mirror) for interfering the separated light. Therefore, the number of components can be reduced, and the size of the device can be suppressed. In addition, since there is no need to provide the optical component 2 for separating and interfering the irradiated light, the loss of light due to reflection and transmission at the optical component 2 can be suppressed. In addition, by interfering the irradiated light reflected from areas at different positions of the object 6, the directional dependence of the detection sensitivity of the defect can be reduced.

[0084] In addition, in the first embodiment, as described above, at least one of the first optical member 21 and the second optical member 22 includes a compound lens pair formed by integrating the first portion 8 and the second portion 10. Thus, the compound lens pair formed by integrating the first portion 8 and the second portion 10 can have two functions: a phase shift function for changing the phase of the second light beam 9 and a deflection function for changing the advancing direction of the first light beam 7. As a result, by using the compound lens pair, the advancing direction of the first light beam 7 can be changed, and the phase of the second light beam 9 can be shifted. Therefore, compared with the case where a semi-transparent mirror, a deflection unit, and a phase shift unit are separately provided, the number of components can be reduced, and the size of the device can be suppressed.

[0085] In the first embodiment, as described above, the first portion 8 is provided on the outside and the second portion 10 is provided on the inside of the first optical member 21 and the second optical member 22. Thus, the first light beam 7 deflected by the first portion 8 provided on the outside and the second light beam 9 phase-shifted by the second portion 10 provided on the inside can be caused to interfere at the position of the imaging element 3.

[0086] In the first embodiment, as described above, the optical member 2 is provided with the light shielding member 12 at the boundary portion between the first portion 8 and the second portion 10. Thus, it is possible to suppress the second light beam 9 having passed through the second portion 10 of the first optical member 21 from passing through the portion of the second optical member 22 that faces the first portion 8, and to suppress the first light beam 7 having passed through the first portion 8 of the first optical member 21 from passing through the second portion 10 of the second optical member 22. Thus, even if the optical path of the first light beam 7 and the optical path of the second light beam 9 are not separated, it is possible to suppress the first light beam 7 and the second light beam 9 from entering the wrong optical path.

[0087] In the first embodiment, as described above, the optical member 2 is arranged close to the position of the aperture stop 13 of the optical system that allows the irradiation light reflected from the object 6 to enter the imaging element 3. As a result, all the light that enters the optical member 2 from the measurement region 61 of the object 6 can be transmitted through the optical member 2, so that the first light beam 7 and the second light beam 9 reflected from each position of the measurement region 61 of the object 6 can be interfered. As a result, a large amount of irradiation light enters the imaging element 3 and interferes with each other, so that the interference of the irradiation light in the entire measurement region 61 of the object 6 can be captured.

[0088] In the first embodiment, as described above, in the optical member 2, the annular first portion 8 surrounds the circular second portion 10 and is disposed adjacent to the second portion 10 when viewed from the incident direction of the irradiation light. Thus, the first portion 8 for changing the advancing direction of the first light beam 7 and the second portion 10 for shifting the phase of the second light beam 9 are adjacent to each other, and thus, compared with a conventional device in which a phase shifting unit for shifting the phase and a deflecting unit for deflecting the advancing direction of the irradiation light are separately provided, the space can be reduced. Thus, it is also possible to suppress the size of the device.

[0089] In the first embodiment, as described above, the surface of the first portion 8 of the first optical member 21 facing the second optical member 22 and the facing surfaces of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 are set to be inclined relative to the direction perpendicular to the incident direction of the irradiated light, and the mutually facing surfaces of the second portion 10 of the first optical member 21 and the second portion 10 of the second optical member 22 are arranged substantially parallel to each other. Thus, the light that has passed through the first portion 8 is refracted by the first portion 8 of the first optical member 21 and then passes through the second optical member 22, so that the advancing direction of the first light beam 7 can be changed. On the other hand, even if the light that has passed through the second portion 10 is refracted due to the inclination of the second portion 10 of the first optical member 21, the second portion 10 of the second optical member 22 is inclined in the same manner as the second portion 10 of the first optical member 21, so that the second light beam 9 is further refracted when passing through the second portion 10 of the second optical member 22 and returns to the original direction. Therefore, the second light beam 9 can be transmitted without changing its advancing direction. In addition, by moving the second optical member 22 in a direction orthogonal to the advancing direction of the second light beam 9, the optical path length of the second light beam 9 transmitted through the second portion 10 can be easily made longer than the optical path length of the first light beam 7 transmitted through the first portion 8. As a result, the phase difference between the first light beam 7 transmitted through the first portion 8 and incident on the imaging element 3 and the second light beam 9 transmitted through the second portion 10 and incident on the imaging element 3 can be easily offset (shifted) according to the difference in optical path length.

[0090] (Second embodiment)

[0091] Next, refer to Figure 1 , Figure 6 to Figure 9, the second embodiment is described. In the second embodiment, an example is described in which, in the first optical component 21, the second part 10 is formed into a circular shape, the first part 8 is formed into a side shape of a cone with the head removed and the top end is connected to the second part 10. In addition, the same structure as the first embodiment is illustrated with the same figure mark as the first embodiment, and the description is omitted. In addition, in the second embodiment, the method of imaging the first light beam 7 and the second light beam 9 reflected at the same point of the object 6 at points or regions at different positions of the imaging element 3 is described, but according to the principle of the conjugate relationship of the imaging optical system, the relationship between the object and the image can be reversed. That is, according to the description in the second embodiment, it is established that the first light beam 7 and the second light beam 9 reflected at points or regions at different positions of the object 6 are imaged at the same point of the imaging element 3.

[0092] like Figure 6 As shown, in the first optical member 31 of the second embodiment, the second portion 10 is formed in a circular shape, and the first portion 8 is formed in a side shape of a cone with the head portion removed, and the tip is connected to the second portion 10 .

[0093] like Figure 7 As shown, the first light beam 7 and the second light beam 9 advance in the optical member 2. Then, the plurality of second light beams 9 that have passed through the first optical member 31 and the second portion 10 of the second optical member 22 proceed directly to the imaging lens 14 and form a point-shaped image on the imaging element 3. On the other hand, the first light beam 7 that has passed through the first optical member 31 and the first portion 8 of the second optical member 22 is deflected by the first portion 8 of the first optical member 31 and enters the imaging lens 14 and forms an image on the imaging element 3.

[0094] like Figure 6 As shown in FIG. 1 , the first portion 8 of the first optical member 31 is in the shape of a truncated cone, so that the first light beam 7 is deflected in a conical shape, and the first light beam 7 is imaged in a circular ring shape around the second light beam 9 that is imaged in a point shape in the imaging element 3. As a result, as shown in FIG. Figure 8 As shown, in the imaging element 3 , the second light beam 9 is located at the center of the first light beam 7 .

[0095] In addition, if Fig. 9 As shown, by deflecting the inclination angle of the first portion 8 , the second light beam 9 is incident on the image pickup element 3 adjacent to the first light beam 7 .

[0096] (Effects of the Second Embodiment)

[0097] In the second embodiment, the following effects can be obtained.

[0098] In the second embodiment, in the first optical member 21, the second portion 10 is formed in a circular shape, and the first portion 8 is formed in a side shape of a cone with the head portion removed, and the top end is connected to the second portion 10. Thus, in the imaging element 3, the first light beam 7 deflected in an annular shape can be incident on the periphery of the second light beam 9.

[0099] In addition, other effects of the second embodiment are the same as those of the above-mentioned first embodiment.

[0100] (Third embodiment)

[0101] Next, refer to Figure 1 , Figure 10 to Figure 12 , the third embodiment is described. In the third embodiment, an example is described in which the first part 8 of the first optical component 41 is formed into a side shape of a polygonal pyramid with the head removed. In addition, the same structure as the first embodiment is illustrated with the same figure mark as the first embodiment, and the description is omitted. In addition, in the third embodiment, the method of imaging the first light beam 7 and the second light beam 9 reflected at the same point of the object 6 at points or areas at different positions of the imaging element 3 is described, but according to the principle of the conjugate relationship of the imaging optical system, the relationship between the object and the image can be swapped. That is, according to the description in the third embodiment, it is established that the first light beam 7 and the second light beam 9 reflected at points or areas at different positions of the object 6 are imaged at the same point of the imaging element 3.

[0102] like Fig.10 As shown, the first portion 8 is formed into a side shape of a polygonal pyramid with the head removed. The second portion 10 is processed into a circular shape. In addition, in order to make the second portion 10 circular, the periphery can also be surrounded by a light shielding member 12 to make the second portion 10 circular.

[0103] like Fig.11 As shown, the first light beam 7 and the second light beam 9 advance in the optical member 2. Then, the first light beam 7 enters the periphery of the portion of the imaging element 3 where the second light beam 9 enters.

[0104] In the third embodiment, Fig.12 As shown in FIG. 1 , in the imaging element 3, a plurality of first light beams 7 are incident on the periphery of the second light beam 9 in a circular ring shape. Fig.12 , the number of faces is 6. The number of first light beams 7 incident on the imaging element 3 changes according to the number of faces. In addition, as the number of faces increases, the first light beams 7 are adjacent to each other, and finally the second embodiment Figure 8 That's close to a ring shape.

[0105] (Effects of the third embodiment)

[0106] In the third embodiment, the following effects can be obtained.

[0107] In the third embodiment, in the first optical member 41 , the first portion 8 is formed in the side surface shape of a polygonal pyramid without a head portion, thereby making it possible to make the deflected first light beam 7 incident on the periphery of the second light beam 9 .

[0108] In addition, other effects of the third embodiment are the same as those of the above-mentioned first embodiment.

[0109] (Fourth embodiment)

[0110] Next, refer to Figure 1 , Figure 13 to Figure 17 A fourth embodiment will be described. In the fourth embodiment, the optical member 2 further includes a third optical member 53 .

[0111] like Fig.13 As shown in (a) of FIG. 4 , in the fourth embodiment, the second optical member 52 , the first optical member 51 , and the third optical member 53 are arranged in this order from the incident direction of the irradiation light.

[0112] In the first optical member 51, the second optical member 52, and the third optical member 53, the first portion 8 is provided on the outside, and the second portion 10 is provided on the inside. The surface of the first portion 8 of the first optical member 51 that faces the second optical member 52 is provided to be inclined relative to the direction (X direction) orthogonal to the incident direction of the irradiation light. Therefore, the irradiation light (first light beam 7) that has passed through the second optical member 52 is refracted at the boundary between the first optical member 51 and the air.

[0113] like Fig.13 As shown in (b), the first portion 8 of the first optical member 51 and the first portion 8 of the third optical member 53 extend in parallel with each other in a direction (X direction) orthogonal to the irradiated light. Therefore, the light refracted when incident on the first portion 8 of the first optical member 51 passes through the third optical member 53 at an unchanged angle relative to the Z direction. Fig.13 In (b), the second optical member 52 is omitted.

[0114] like Fig.13 As shown in (a), the surface of the second part 10 of the second optical component 52 opposite to the first optical component 51, and the surface of the second part 10 of the first optical component 51 opposite to the second optical component 52 are inclined relative to the first direction (X direction) orthogonal to the incident direction (Z direction) of the irradiated light.

[0115] like Fig.13As shown in (b), the surface of the second portion 10 of the first optical component 51 opposite to the third optical component 53, and the surface of the second portion 10 of the third optical component 53 opposite to the first optical component 51 are inclined relative to the second direction (Y direction) orthogonal to the incident direction (Z direction) of the irradiated light. Therefore, the direction of the outgoing light of the irradiated light passing through the second portion 10 is inclined toward the X direction due to the second portion 10 of the first optical component 51, and returns to the original direction when incident on the second optical component 52. Furthermore, the direction of the light emitted from the second portion 10 of the second optical component 52 is inclined toward the Y direction, and returns to the original direction when incident on the third optical component 53. That is, as a result, the irradiated light goes straight through the first optical component 51, the second optical component 52, and the third optical component 53. Then, the second light beam 9 that has passed through the second portion 10 reaches the imaging element 3 (refer to Figure 1 ).

[0116] like Fig.14 As shown in (a), the rotation mechanism includes a first rotation mechanism 16 that rotates the first optical member 51 and the third optical member 53 relative to the second optical member 52 as a whole, and a second rotation mechanism 17 that rotates the third optical member 53 relative to the first optical member 51. Fig.14 (a) Fig.14 (b) and Fig.14 In (c) of FIG. 1 , the first rotating mechanism 16 is hatched.

[0117] like Fig.14 As shown in (a), the first rotating mechanism 16 is mounted on the first optical member 51. The first rotating mechanism 16 is, for example, a rotatable holder. In addition, the first rotating mechanism 16 has a portion for carrying the third optical member 53, and the third optical member 53 is carried on the first rotating mechanism 16. Therefore, when the first optical member 51 is rotated by the first rotating mechanism 16, the carried third optical member 53 is also rotated at the same time. Therefore, the first rotating mechanism 16 can rotate the first optical member 51 and the third optical member 53 integrally.

[0118] like Fig.14 As shown in (a), the second rotating mechanism 17 is mounted on the third optical member 53 from the side opposite to the side of the third optical member 53 that faces the first optical member 51. The second rotating mechanism 17 is rotated by, for example, a jig 17a. The third optical member 53 is provided with a hole 17b (see Fig.13 (b)). In addition, the first optical member 51 is provided with a hole 16a for mounting the jig 17a on the third optical member 53 and rotating it (see Fig.13In (b), when the jig 17a is rotated, the first rotating mechanism 16 and the first optical member 51 do not rotate. The second rotating mechanism 17 is configured to rotate the third optical member 53 by rotating the attached jig 17a.

[0119] like Fig.15 As shown in FIG. 1 , the second portion 10 of the optical member 2 has a property of refracting the irradiated light in an oblique direction. In addition, the direction in which the irradiated light is refracted can be changed by rotating the optical member 2 .

[0120] based on Fig.14 , a method of adjusting the direction of the second light beam 9 in the X direction and the Y direction is described.

[0121] Fig.14 (a) shows the arrangement of the first optical member 51 , the second optical member 52 , and the third optical member 54 before adjustment.

[0122] like Fig.14 As shown in (b), the first rotating mechanism 16 is used to rotate the first optical member 51 and the third optical member 53 simultaneously. As a result, the direction of the outgoing light can be adjusted along the direction in which the second portion 10 of the first optical member 51 extends relative to the second portion 10 of the third optical member 53, that is, the Y direction, without changing the direction of the outgoing light along the direction in which the second portion 10 of the first optical member 51 extends relative to the second portion 10 of the third optical member 53, that is, the X direction. In addition, Fig.14 (b) shows the relative Fig.14 (a) is an example in which the first optical member 51 and the second optical member 52 are rotated 90 degrees, but the rotation angle may be smaller than 90 degrees.

[0123] Next, if Fig.14 As shown in (c), the third optical member 53 is rotated by the second rotating mechanism 17, thereby adjusting the direction of the refracted outgoing light along the direction in which the second portion 10 of the first optical member 51 relative to the second portion 10 of the second optical member 52 extends, that is, the X direction, without changing the direction of the outgoing light along the direction in which the second portion 10 of the first optical member 51 relative to the second portion 10 of the second optical member 52 extends, that is, the Y direction. In addition, Fig.14 (c) shows the relative Fig.14 (b) is an example of a 90 degree rotation, but the rotation angle can also be less than 90 degrees.

[0124] based on Fig.16 and Fig.17 , a description will be given of a change in position of the second light beam 9 of the second portion 10 that has passed through the first optical member 51 , the second optical member 52 , and the third optical member 53 .

[0125] exist Fig.16 and Fig.17 In FIG. 1 , a point 93 indicates the position of the second light beam 9 that has passed through the second portion 10 of the first optical member 51, the second optical member 52, and the third optical member 53 and is irradiated on the imaging element 3, a circle 91 indicates the trajectory of the irradiated light that has passed through the second portion 10 of the first optical member 51, the second optical member 52, and the third optical member 53 when the first optical member 51 and the third optical member 53 are rotated integrally by the first rotating mechanism 16, and a circle 92 indicates the trajectory of the irradiated light that has passed through the second portion 10 of the first optical member 51, the second optical member 52, and the third optical member 53 when the third optical member 53 is rotated by the second rotating mechanism 17. In addition, a point 94 indicates the ideal position (adjustment position) of the second light beam 9. Furthermore, a point 95 indicates the position of the first light beam 7 that has passed through the first portion 8 of the first optical member 51, the second optical member 52, and the third optical member 53.

[0126] like Fig.17 As shown in (a) , the second light beam 9 of the second portion 10 that has passed through the first optical member 51 , the second optical member 52 , and the third optical member 53 is adjusted to be irradiated to the position of the point 94 when irradiating to the position of the point 93 .

[0127] like Fig.17 As shown in (b), when the second rotating mechanism 17 is rotated to adjust the position in the Y direction, point 93 is automatically Fig.17 The position of (a) moves in the Y direction. At this time, the first rotating mechanism 16 is used to adjust so that the position of the point 94 in the Y direction is the same as the position of the point 93 in the Y direction.

[0128] like Fig.17 As shown in (c), when the first rotating mechanism 16 is rotated to adjust the position in the X direction, point 93 is Fig.17 The position of (b) is moved in the X direction. At this time, the first rotating mechanism 16 is used to adjust so that the point 93 and the point 94 overlap. Thus, the position irradiated by the first light beam 7 and the position irradiated by the second light beam 9 are adjusted.

[0129] (Effects of the Fourth Embodiment)

[0130] In the fourth embodiment, the following effects can be obtained.

[0131] In the fourth embodiment, it includes a third optical member 53 arranged opposite to the first optical member 51, the surface of the second part 10 of the first optical member 51 opposite to the second optical member 52, and the surface of the second part 10 of the second optical member 52 opposite to the first optical member 51 are inclined relative to a first direction orthogonal to the incident direction of the irradiated light, and the surface of the second part 10 of the first optical member 51 opposite to the third optical member 53, and the surface of the second part 10 of the third optical member 53 opposite to the first optical member 51 are inclined relative to a second direction orthogonal to the incident direction of the irradiated light and intersecting the first direction. In the fourth embodiment, there is also a rotating mechanism that changes the relative angle between the first direction and the second direction by rotating the third optical member 53. Thus, by rotating the third optical member 53 by the rotating mechanism to change the relative angle between the first direction and the second direction, the angle of the surface of the optical member 2 where the second light beam 9 is incident or emitted relative to the irradiation direction can be changed, and thus the angle of refraction of the second light beam 9 can be changed. Therefore, the position where the second light beam 9 is irradiated can be adjusted, and thus the relative position between the first light beam 7 and the second light beam 9 can be adjusted. As a result, even when there is a manufacturing error in the optical member 2, the relative position between the first light beam 7 and the second light beam 9 can be adjusted to suppress the occurrence of individual differences in the displacement measurement device 100 (interference image pickup device).

[0132] In the fourth embodiment, the rotation mechanism includes a first rotation mechanism 16, and the first rotation mechanism 16 rotates the first optical member 51 and the third optical member 53 integrally with respect to the second optical member 52. Thus, by integrally rotating the first optical member 51 and the third optical member 53, the relative position of the second optical member 52 and the first optical member 51 can be changed without changing the relative position of the first optical member 51 and the third optical member 53. Thus, the angle of refraction of the second light beam 9 with respect to the first direction can be adjusted without changing the angle of refraction of the second light beam 9 with respect to the second direction.

[0133] In the fourth embodiment, the rotation mechanism includes a second rotation mechanism 17 in addition to the first rotation mechanism 16, and the second rotation mechanism 17 rotates the third optical member 53 relative to the first optical member 51. Thus, the relative position of the second optical member 52 and the first optical member 51 can be changed by the first rotation mechanism 16, and the relative position of the first optical member 51 and the second optical member 52 can be changed by the second rotation mechanism 17. Thus, in addition to adjusting the angle of refraction of the second light beam 9 with respect to the first direction, the angle of refraction of the second light beam 9 with respect to the second direction can also be adjusted.

[0134] In the fourth embodiment, the second optical member 52, the first optical member 51, and the third optical member 53 are arranged in order from the incident direction of the irradiation light. Thus, the direction of the irradiation light whose phase is changed by the second optical member 52 and the first optical member 51 can be changed, and therefore, the relative position of the irradiation light whose phase is changed and the irradiation light deflected by the second optical member 52 or the first optical member 51 can be adjusted.

[0135] In addition, other effects of the fourth embodiment are the same as those of the above-mentioned first embodiment.

[0136] (Fifth embodiment)

[0137] Next, refer to Figure 1 , Figures 18 to 20 The fifth embodiment will be described. In the fifth embodiment, unlike the fourth embodiment, the optical member 2 is rotated by the first rotating mechanism 16 or the second rotating mechanism 17 to change the direction in which the second light beam 9 is transmitted.

[0138] In the fifth embodiment, Fig.18 As shown, the incident direction of the self-illumination light is the second optical member 72, the first optical member 71, and the third optical member 73, which are arranged in this order.

[0139] like Fig.18 As shown in (a), the opposing surfaces of the second optical member 72 and the first optical member 71 are parallel to each other. In addition, the opposing surfaces of the first optical member 71 and the third optical member 73 are parallel to each other. Therefore, the irradiated light travels straight through the second optical member 72, the first optical member 71, and the third optical member 73.

[0140] like Fig.18 As shown in (b), when the third optical member 73 is rotated by the second rotating mechanism 17, the outer portion of the surface of the third optical member 73 and the first optical member 71 facing each other is parallel, so that the irradiation light is not deflected. On the other hand, in the inner portion of the surface of the third optical member 73 and the first optical member 71 facing each other, the inner surface of the third optical member 73 is inclined relative to the inner surface of the first optical member 71. Therefore, when the irradiation light is incident on the third optical member 73, it is refracted in the X direction and deflected.

[0141] Fig.19This is a diagram showing the state after the first optical member 71 and the third optical member 73 are rotated by the first rotating mechanism 16 as viewed from the side (Y direction). When the first optical member 71 and the third optical member 73 are rotated by the first rotating mechanism 16, the first optical member 71 facing the inner surface of the second optical member 72 is inclined relative to the inner surface of the second optical member 72, so that the irradiation light (second light beam 9) is refracted in the Y direction and deflected. On the other hand, the inner portion of the surface of the third optical member 73 facing the first optical member 71 is parallel, so the deflected irradiation light passes through the third optical member 73 without further refracting.

[0142] like Fig. 20 As shown in (a), before adjustment, the irradiation light that has passed through the outer side of the first optical member 71, the second optical member 72, and the third optical member 73 and the irradiation light that has passed through the inner side are irradiated toward the position of the point 93. Then, as shown in Fig. 20 As shown in (b) of FIG. 8 , by rotating the first rotating mechanism 16 or the second rotating mechanism 17 , the irradiation light that has passed through the inner portion is irradiated toward the position of the point 96 .

[0143] (Effects of the Fifth Embodiment)

[0144] In the fifth embodiment, the following effects can be obtained.

[0145] In the fifth embodiment, there is an optical member 2, which is provided with an irradiation light reflected or transmitted from a point or region at a different position of an object 6, divided into a first light beam 7 and a second light beam 9 and transmitted through the optical member 2, and the optical member 2 causes the transmitted first light beam 7 and the second light beam 9 to interfere with each other; and a rotation mechanism that rotates at least a part of the optical member 2, the optical member 2 includes a first optical member 71, a second optical member 72, and a third optical member 73, and the rotation mechanism causes at least one of the first optical member 71 and the third optical member 73 to rotate. Thus, the relative angle between the first light beam 7 and the second light beam 9 is changed, and the first optical member 71 and the second optical member 72 are configured to allow the second light beam 9 to pass through and change the phase of the second light beam 9. Therefore, it is not necessary to separate the irradiation light in two directions, and therefore it is not necessary to provide an optical member (half-transparent mirror) for separating the light and an optical member (half-transparent mirror) for interfering the separated light. In addition, by providing the first optical member 71 and the second optical member 72, it is not necessary to provide a phase shifter. Furthermore, due to the rotation mechanism, there is no need to set a deflector. As a result, the first optical component 71, the second optical component 72 and the rotation mechanism are provided to replace the phase shifter and the deflector, but there is no need to set an optical component (semi-transparent and semi-reflective mirror) for separating the light and an optical component (semi-transparent and semi-reflective mirror) for interfering the separated light. Therefore, the number of components can be reduced, and the large-scale device can be suppressed. In addition, since there is no need to set an optical component for separating and interfering the irradiated light, the loss of light due to reflection and transmission at the optical component can be suppressed.

[0146] In addition, other effects of the fifth embodiment are the same as those of the fourth embodiment described above.

[0147] [Modifications]

[0148] The embodiments disclosed herein are illustrative in all aspects and should not be construed as limiting. The scope of the present invention is not indicated by the description of the embodiments described above but by the claims, and includes all modifications (variations) within the meaning and scope equivalent to the claims.

[0149] For example, in the above-mentioned embodiment, an example of using the interference image pickup device of the present invention for defect inspection is shown, but the present invention is not limited thereto. For example, the interference image pickup device of the present invention may also be used for other purposes.

[0150] In the above embodiment, an example of using the interference imaging device for defect inspection by applying sound waves to an object is shown, but the present invention is not limited thereto. For example, instead of applying sound waves, heat other than sound waves may be applied to the object.

[0151] In addition, in the above-mentioned embodiment, an example is shown in which the first portion is provided on the outside and the second portion is provided on the inside, but the present invention is not limited to this. In the present invention, the first portion may also be located on the inside.

[0152] In the above embodiment, an example is shown including a compound lens pair formed by integrating the first part and the second part, but the present invention is not limited thereto. For example, a member that transmits the irradiation light and deflects and shifts the phase of the irradiation light may not be a lens.

[0153] In addition, in the above-mentioned embodiment, an example is shown in which, in the optical member, the annular first portion surrounds the circular second portion and is arranged adjacent to the second portion when viewed from the incident direction of the irradiated light, but the present invention is not limited thereto. For example, the first portion and the second portion may be polygonal when viewed from the incident direction of the irradiated light.

[0154] In addition, in the present invention, for example, a part of the first portion of the optical member may be composed of a diffuser such as ground glass or a holographic diffuser. Fig.21 As shown, in the image pickup element, the first light beam is scattered at a plurality of locations around the second light beam.

[0155] In addition, in the above-mentioned embodiment, an example of separating the reflected light from the object into the first light beam and the second light beam is shown, but the present invention is not limited to this. For example, instead of separating the light reflected from the object into the first light beam and the second light beam, the transmitted light from the object may be separated into the first light beam and the second light beam.

[0156] In addition, in the above-mentioned embodiment, an example in which the interference image pickup device is used in a displacement measuring device is shown, but the present invention is not limited to this. For example, the interference image pickup device may be used in a microscope or the like.

[0157] In addition, in the above-mentioned embodiment, an example in which the first part is composed of the first optical component is shown, but the present invention is not limited to this. For example, the first part may also be composed of the second optical component. In this case, in the second optical component, the first part and the second part are integrated.

[0158] In the above embodiment, an example is shown in which the first portion and the second portion of the surface of the first optical member are inclined at the same angle, but the present invention is not limited thereto. For example, they may be inclined at different angles.

[0159] In the above embodiment, an example of a single inclined surface or a cone shape is shown as the shape of the first portion, but the present invention is not limited thereto. For example, two inclined surfaces or curved surfaces may be used for the first portion to deflect the first light beam.

[0160] In addition, in the above-mentioned embodiment, an example of a convex shape in which the thickness of the second part is greater than the thickness of the first part in the first optical member and the second optical member is shown, but the present invention is not limited to this. For example, it can also be a concave shape in which the thickness of the first optical member and the second part is smaller than the thickness of the first part.

[0161] In addition, in the above-mentioned embodiment, an example in which the imaging lens is arranged behind the optical component is shown, but the present invention is not limited to this. For example, the imaging lens can also be arranged in front of the optical component. In addition, the imaging lens can also be composed of multiple lenses or multiple lens groups. For example, it is also possible to make the imaging lens composed of the first lens group and the second lens group, and the first lens group is arranged in front of the optical component, and the second lens is arranged behind the optical component. In this case, if the first lens group is set as a concave lens system, the angle of the light incident on the aperture stop can be made close to parallel, so it is preferred.

[0162] In addition, in the fourth and fifth embodiments, the second optical member, the first optical member, and the third optical member are sequentially arranged from the incident direction of the irradiated light, but the present invention is not limited thereto. For example, the third optical member, the first optical member, and the second optical member may be sequentially arranged from the incident direction of the irradiated light.

[0163] In the fourth and fifth embodiments, the displacement measuring device (interference imaging device) uses the second optical member to change the phase, but the present invention is not limited thereto. For example, the phase may be changed using the third optical member.

[0164] In addition, in the fifth embodiment, an example of deflecting the second light beam is shown, but the present invention is not limited to this. For example, the first light beam may be deflected instead of the second light beam. In this case, the outer portion of the third optical member relative to the first optical member is inclined relative to the outer portion of the first optical member relative to the third optical member, and the inner portions of the first optical member and the third optical member relative to each other are parallel to each other.

[0165] Description of Reference Numerals

[0166] 1. Illuminating unit; 2. Optical component; 3. Image pickup element (image pickup unit); 6. Object; 7. First light beam; 8. First portion; 9. Second light beam; 10. Second portion; 11. Actuator; 12. Shading component; 13. Aperture stop; 14. Imaging lens; 21, 31, 41, 51, 71, first optical component; 22, 52, 72, second optical component; 100. Displacement measuring device (interference image pickup device).

Claims

1. An interference image capturing device, wherein: The interference image camera device comprises: an irradiation unit that irradiates an irradiation light from a laser light source toward a measurement region of the object; an optical member through which the irradiation light reflected or transmitted from points or regions at different positions of the object is divided into a first light beam and a second light beam and passes through the optical member, and the optical member causes the transmitted first light beam and the second light beam to interfere with each other; an imaging unit that captures an intensity pattern of the first light beam and an intensity pattern of the second light beam that have been transmitted through the optical member and interfered with each other; and a rotating mechanism that rotates at least a portion of the optical member, The optical member includes a first optical member, a second optical member disposed opposite to the first optical member, and a third optical member disposed opposite to the first optical member on a side opposite to a side on which the second optical member is disposed. The rotation mechanism is configured to change a relative angle between the first light beam and the second light beam by rotating at least one of the first optical member and the third optical member. The first optical member and the second optical member are configured to transmit the second light beam and change the phase of the second light beam.

2. An interference image camera device, wherein: The interference image camera device comprises: an irradiation unit that irradiates an irradiation light from a laser light source toward a measurement region of the object; an optical member through which the irradiation light reflected or transmitted from points or regions at different positions of the object is divided into a first light beam and a second light beam and passes through the optical member, and the optical member causes the transmitted first light beam and the second light beam to interfere with each other; as well as an imaging unit that captures an intensity pattern of the first light beam and an intensity pattern of the second light beam after being transmitted through the optical member and interfering with each other, The optical member includes a first optical member and a second optical member arranged to face each other. The optical component comprises: a first part, which is composed of at least one of the first optical component and the second optical component, and allows the first light beam to pass through and changes the direction of the outgoing light relative to the direction of the incident light; and a second part, which is composed of the first optical component and the second optical component, and allows the second light beam to pass through and changes the phase of the second light beam relative to the first light beam.

3. The interference image capturing device according to claim 2, wherein: At least one of the first optical member and the second optical member includes a composite lens pair in which the first portion and the second portion are integrated.

4. The interference image capturing device according to claim 2, wherein: In the first optical member and the second optical member, the first portion is provided on the outside, and the second portion is provided on the inside.

5. The interference image capturing device according to claim 2, wherein: The optical member includes a light shielding member at a boundary portion where the first portion and the second portion are adjacent to each other.

6. The interference image capturing device according to claim 2, wherein: The optical member is disposed close to a position of an aperture stop of an optical system that allows the irradiation light reflected from the object to enter the imaging unit.

7. The interference image capturing device according to claim 2, wherein: In the optical member, the annular first portion is arranged adjacent to the second portion so as to surround the circular second portion when viewed from the incident direction of the irradiation light.

8. The interference image capturing device according to claim 2, wherein: The surface of the first part of the first optical component opposite to the second optical component, and the opposing surfaces of the second part of the first optical component and the second part of the second optical component are set to be inclined relative to a direction orthogonal to the incident direction of the irradiated light, and the opposing surfaces of the second part of the first optical component and the second part of the second optical component are arranged to be substantially parallel to each other.

9. The interference image capturing device according to claim 2, wherein: In the first optical member, the second portion is formed in a circular shape when viewed from the incident direction of the irradiation light, and the first portion is formed in a side shape of a cone with the head portion removed, and the tip is connected to the second portion.

10. The interference image capturing device according to claim 2, wherein: In the first optical member, the first portion is formed in a side shape of a polygonal pyramid with a head portion removed when viewed from the incident direction of the irradiation light.

11. The interference image capturing device according to claim 2, wherein: The optical member includes a third optical member arranged to face the first optical member, A surface of the second portion of the first optical member facing the second optical member and a surface of the second portion of the second optical member facing the first optical member are inclined with respect to a first direction orthogonal to an incident direction of the irradiation light, and The surface of the second portion of the first optical member facing the third optical member and the surface of the second portion of the third optical member facing the first optical member are inclined with respect to a second direction that is orthogonal to the incident direction of the irradiation light and intersects the first direction. The interference image capturing device further includes a rotation mechanism that changes a relative angle between the first direction and the second direction by rotating the third optical member.

12. The interference image capturing device according to claim 11, wherein: The rotation mechanism includes a first rotation mechanism that integrally rotates the first optical member and the third optical member relative to the second optical member.

13. The interference image capturing device according to claim 12, wherein: The rotation mechanism includes a second rotation mechanism in addition to the first rotation mechanism, and the second rotation mechanism rotates the third optical member relative to the first optical member.

14. The interference image capturing device according to claim 11, wherein: The second optical member, the first optical member, and the third optical member are arranged in this order from the incident direction of the irradiation light.

Images