Optical displacement meter

Abstract

The utility model provides an optical displacement meter which can prevent interference light from invading due to the change of the relative angle between a light projection system and a light receiving window and prevent the performance from becoming poor. The present invention is provided with: a light projection / reception module having a light projection unit for irradiating slit light extending in the X direction, a light reception lens for converging reflected light obtained by reflecting the slit light by a workpiece, a bandpass filter fixed in position relative to the light reception lens, and an imaging unit for receiving the converged light; a motor that integrally rotates the light-projecting / light-receiving module; a housing provided with a light receiving window through which the reflected light passes; and a control unit that controls the motor to scan the slit light in a direction orthogonal to the X direction. The light receiving window transmits light in a predetermined wavelength range including the wavelength range of the slit light irrespective of the rotation angle of the light projecting / receiving module during the measurement operation, and the band-pass filter selectively transmits or reflects reflected light of the slit light among the light transmitted through the light receiving window to cause the reflected light to enter the imaging unit.

Description

Technical Field

[0001] The utility model relates to an optical displacement meter. Background Art

[0002] When using a conventional optical displacement meter to obtain the two-dimensional profile of the XZ cross section of the measured object (workpiece) at different positions in the Y direction and generate three-dimensional shape data based on these two-dimensional profiles, the conventional optical displacement meter must be moved relative to the workpiece in the Y direction. Therefore, a conveyor belt for transporting the workpiece and a direct-acting mechanism for moving the conventional optical displacement meter body relative to the workpiece are required. However, the installation space and cost may become obstacles to the introduction of the above-mentioned equipment.

[0003] On the other hand, as an optical displacement meter that can obtain the two-dimensional contours of the XZ cross-section of the workpiece at different positions in the Y direction and generate three-dimensional shape data based on these two-dimensional contours without the need for the above-mentioned equipment, an optical displacement meter that rotates the light projection system and the light receiving system is known (see Patent Documents 1 and 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: European Patent Application Publication No. 3232152

[0007] Patent Document 2: Chinese Utility Model Specification No. 210664364 Utility Model Content

[0008] Problems to be solved by utility models

[0009] The optical displacement meter is a structure in which a light-projecting system and a light-receiving system are housed in a housing and a light-projecting window and a light-receiving window are provided in the housing to prevent dust from adhering to the light-projecting system and the light-receiving system. A bandpass filter is formed in the light-receiving window to prevent the intrusion of interference light having a wavelength range different from the wavelength range of the slit light irradiated from the optical displacement meter. For example, the relationship between the wavelength range and transmittance of a bandpass filter composed of an optical thin film filter changes according to the incident angle of the incident light. In general, when the incident angle to the bandpass filter increases from 0 degrees (vertical incidence), the wavelength range with high transmittance shifts to the short wavelength side.

[0010] In an optical displacement meter in which the angle between the optical axis of the light-receiving lens and the light-receiving window is fixed, the angle at which the light on the optical axis, i.e., the light that can be most concentrated by the light-receiving lens, is incident on the bandpass filter formed on the light-receiving window is also fixed, so the transmission characteristics of the bandpass filter for the light on the optical axis do not substantially change.

[0011] On the other hand, the following problem has been found in optical displacement meters that rotate the light-projecting system and the light-receiving system as in Patent Documents 1 and 2. That is, when the light-projecting system and the light-receiving system are rotated in a housing having a light-receiving window, the angle between the optical axis of the light-receiving lens and the light-receiving window changes, and therefore, when a band-pass filter is formed on the light-receiving window, the angle at which light on the optical axis is incident on the band-pass filter also changes.

[0012] The reflected light obtained by reflecting the slit light emitted from the projection system and reflected by the workpiece, the light focused by the light receiving lens is incident on the bandpass filter with the optical axis of the light receiving lens as the center. Therefore, due to the change in the angle between the optical axis and the bandpass filter, the amount of reflected light of the slit light passing through the bandpass filter is reduced, and the measurement accuracy is also reduced.

[0013] By using a bandpass filter with high transmittance in a wider wavelength range, the amount of reflected light from the slit light passing through the bandpass filter can be suppressed, but it becomes susceptible to interference light, so it is inevitable that the measurement accuracy will be reduced. Patent Documents 1 and 2 do not mention the housing or the light receiving window, and no countermeasures are taken to address the above-mentioned problem.

[0014] In view of the above problems, an object of the present invention is to provide an optical displacement meter capable of suppressing the influence of disturbance light while suppressing a decrease in the amount of light received by reflected light of slit light even if a light projecting system and a light receiving system are rotated.

[0015] Solutions for solving problems

[0016] An optical displacement meter according to one aspect of the present invention comprises, for example: a light-projecting and light-receiving module having a light-projecting portion for irradiating slit light extending in an X direction, a light-receiving lens for converging reflected light obtained by reflecting the slit light from a workpiece, a band-pass filter fixed in relative position to the light-receiving lens, and an imaging portion for receiving light converged by the light-receiving lens; a motor for integrally rotating the light-projecting and light-receiving module; a housing for accommodating the light-projecting and light-receiving module and provided with a light-receiving window for transmitting the reflected light; and a control portion for controlling the motor to scan the slit light in a direction orthogonal to the X direction, wherein the light-receiving window transmits light of a predetermined wavelength range including the wavelength range of the slit light regardless of the rotation angle of the light-projecting and light-receiving module in a measuring operation, and the band-pass filter selectively transmits or reflects the reflected light of the slit light among the light transmitted through the light-receiving window so as to allow the reflected light to enter the imaging portion.

[0017] Preferably, through the rotation of the light-projecting and light-receiving module, the angle formed by the optical axis of the light-receiving lens and the light-receiving window changes within a specified angle range. On the other hand, regardless of the rotation angle of the light-projecting and light-receiving module, the angle formed by the optical axis of the light-receiving lens and the bandpass filter is constant.

[0018] Preferably, the light projecting and light receiving module also has a supporting member, and the light projection axis of the light projecting unit, the light receiving lens and the camera unit are fixed to the supporting member in a manner that satisfies the relationship of Scham's law regardless of the rotation angle in the measuring action, and the bandpass filter is fixed to the supporting member in a manner that the relative position with respect to the light receiving lens is fixed, and regardless of the rotation angle, the reflected light obtained by reflecting the slit light from the workpiece located in the focal plane in the relationship of Scham's law enters the bandpass filter at a constant incident angle.

[0019] Preferably, the bandpass filter is arranged in the light-projecting and light-receiving module at a position which is approximately orthogonal to the optical axis of the light-receiving lens regardless of the rotation of the light-projecting and light-receiving module, and the reflected light passing through the light-receiving window passes through the bandpass filter, thereby allowing the light in the wavelength range of the slit light to be incident on the camera unit.

[0020] Preferably, the imaging unit includes a plurality of pixels arranged two-dimensionally and a cover glass for protecting the plurality of pixels, and the bandpass filter includes a plurality of optical thin films stacked on the cover glass.

[0021] Preferably, regardless of the rotation of the light projecting and receiving module, the cover glass and the bandpass filter are arranged substantially orthogonal to the optical axis of the light receiving lens and inclined with respect to the light receiving surfaces of the plurality of pixels.

[0022] Preferably, the light receiving lens includes a plurality of lenses, and the bandpass filter is arranged on the surface of each lens among the plurality of lenses. The light passing through the light receiving window passes through the bandpass filter arranged on the surface of each lens in sequence, thereby the reflected light of the slit light is selectively incident on the camera unit.

[0023] Preferably, the light projection and light receiving module also has a reflective component whose relative position with the light receiving lens is fixed, the reflective component is arranged on the optical path between the light receiving window and the camera unit, the bandpass filter is composed of a plurality of optical films stacked on the reflective component, and the reflective component and the bandpass filter selectively reflect the reflected light of the slit light among the light that passes through the light receiving window and is incident on the bandpass filter and the reflective component at a specified angle toward the camera unit.

[0024] Preferably, the light projecting and receiving module further includes a supporting member, and the light projection axis of the light projecting unit, the light receiving lens, the reflecting member, and the camera unit are fixed to the supporting member in a manner that satisfies the relationship of Scham's law regardless of the rotation angle in the measuring operation.

[0025] Preferably, the light receiving window is composed of a colored glass filter, which has a substantially constant transmittance within the specified wavelength range regardless of changes in the incident angle, and a transmittance within a first wavelength range including the wavelength range of the slit light is higher than a transmittance outside the first wavelength range and within the specified wavelength range. Regardless of the rotation angle of the light projection and light receiving module in the measuring action, the colored glass filter transmits the light within the first wavelength range, and the bandpass filter selectively passes or reflects the reflected light of the slit light among the light that has passed through the colored glass filter, so that the reflected light is incident on the imaging unit.

[0026] The optical displacement meter involved in other aspects of the utility model comprises, for example: a light-projecting and light-receiving module, which has a light-projecting portion for irradiating a slit light extending in the X direction, a light-receiving lens for converging the reflected light obtained by reflecting the slit light off the workpiece, and a camera portion for receiving the light converged by the light-receiving lens; a motor for rotating the light-projecting and light-receiving module as a whole; a housing for accommodating the light-projecting and light-receiving module and provided with a light-receiving window for transmitting the reflected light; and a control portion for controlling the motor to scan the slit light in a direction orthogonal to the X direction. , wherein the light receiving window is composed of a colored glass filter, and the colored glass filter has a substantially constant transmittance within a specified wavelength range including the wavelength range of the slit light regardless of changes in the incident angle, and the transmittance within the wavelength range of the slit light is higher than the transmittance within the specified wavelength range outside the wavelength range of the slit light, and regardless of the rotation angle of the light projection and light receiving module in the measuring action, the colored glass filter selectively allows the reflected light of the slit light to pass through so that the reflected light is incident on the camera unit.

[0027] In addition, other features, elements, steps, advantages, and characteristics will become more apparent from the following modes for carrying out the invention and the accompanying drawings related thereto.

[0028] Effect of utility model

[0029] According to one aspect of the utility model, the angle range of the incident light of the slit light to the light receiving window is wider than that of the conventional non-rotating optical displacement meter. Therefore, by providing a bandpass filter that allows the light with a wavelength range wider than the wavelength range of the slit light to pass through the light receiving window regardless of the incident angle and is fixed in relative position to the light receiving lens, it is possible to suppress the reduction in the amount of reflected light of the slit light condensed by the light receiving lens passing through the bandpass filter regardless of the rotation while suppressing the influence of interference light. According to another aspect of the utility model, the light receiving window uses a colored glass filter, and the colored glass filter has a characteristic that the transmittance is substantially constant regardless of the change in the incident angle within a specified wavelength range including the wavelength range of the slit light. Therefore, it is possible to suppress the reduction in the amount of light received by the reflected light of the slit light caused by the rotation of the light projection and light receiving module during the measurement operation while suppressing the influence of interference light. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a diagram for explaining an optical displacement measuring system.

[0031] Figure 2 It is a diagram illustrating the principle of triangulation.

[0032] Figure 3 It is a diagram for explaining an optical displacement meter including a reflecting member.

[0033] Figure 4 It is a diagram for explaining the method of detecting the peak position.

[0034] Figure 5 This is a functional block diagram of an optical displacement meter.

[0035] Figure 6 This is a diagram for explaining a first example of the arrangement of the motor.

[0036] Figure 7 This is a diagram for explaining a first example of the arrangement of the motors.

[0037] Figure 8 It is a diagram for explaining a second example of the arrangement of the motors.

[0038] Fig. 9 It is a diagram for explaining a second example of the arrangement of the motors.

[0039] Fig.10 1 is a diagram showing a processing flow of a measurement operation of the optical displacement measurement system.

[0040] Fig.11 It is a diagram for explaining a first arrangement example of the bandpass filter.

[0041] Fig.12 It is a diagram for explaining a second arrangement example of the bandpass filter.

[0042] Fig.13 It is a diagram for explaining a third arrangement example of the bandpass filter.

[0043] Fig.14 It is a diagram for explaining a fourth arrangement example of the bandpass filter.

[0044] Fig.15 It is a diagram for explaining a fifth arrangement example of the bandpass filter.

[0045] Fig.16 This is a diagram for explaining the relationship between the wavelength range of slit light and the transmission characteristics of a bandpass filter and a light receiving window. DETAILED DESCRIPTION

[0046] <Optical displacement measurement system>

[0047] Figure 1 1 is a diagram showing a schematic configuration example of an optical displacement measuring system. An optical displacement measuring system 100 of this configuration example includes an optical displacement meter 1 , a control device 2 , a display device 3 , and an input device 4 .

[0048] In this configuration example, the X direction corresponds to the width direction of the slit light L1 output from the optical displacement meter 1, the Z direction corresponds to the height direction of the workpiece W, and the Y direction corresponds to the direction of the slit light L1 passing through the light projection unit (in Figure 1 The XZ plane described later is a plane extending along the X direction and the Z direction. In addition, the optical displacement meter 1 scans the slit light L1 by rotating the light-projecting and light-receiving module 20, so the scanning direction of the slit light L1 is a direction orthogonal to the X direction on the YZ plane, including the Y direction. In addition, in this specification, "rotation" means reciprocating swinging motion centered on the rotation axis.

[0049] The optical displacement measurement system 100 is a system for measuring the contour and three-dimensional shape of a workpiece W. The contour of the workpiece W refers to data indicating the outer edge of a cross-section surface of the workpiece W generated by the slit light L1. When the slit light is irradiated parallel to the XZ plane, the contour of the workpiece W becomes data indicating the outer edge of the cross-section surface parallel to the XZ plane, and is therefore also referred to as a two-dimensional contour of the XZ cross section of the workpiece W.

[0050] For example, a contour is a collection of (xi, zi) (i is an index). xi represents the position in the X direction. zi represents the height in the Z direction. In addition, a three-dimensional shape is a collection of (xi, yi, zi). yi represents the position in the Y direction.

[0051] The optical displacement meter 1 operates according to the instruction from the control device 2. The optical displacement meter 1 outputs the slit light L1 extending in the X direction and receives the reflected light L2 from the workpiece W. Moreover, the optical displacement meter 1 calculates the contour of the workpiece W based on the light reception result. The optical displacement meter 1 performs imaging at regular intervals to generate the contours of different workpieces W. In addition, the optical displacement meter 1 generates the three-dimensional shape data of the workpiece W based on the contours of different workpieces W.

[0052] The control device 2 outputs instructions based on user input received by the input device 4 to the optical displacement meter 1, and receives measurement results of the workpiece W from the optical displacement meter 1. The control device 2 also outputs display signals to the display device 3. The control device 2 is, for example, a personal computer or a programmable logic controller.

[0053] The display device 3 displays, for example, the measurement result of the workpiece W, a UI (User Interface) for setting the optical displacement meter 1 , and the like based on a display signal from the control device 2 .

[0054] The input device 4 receives user input to the optical displacement measuring system 100. Figure 1 In FIG. 4 , a keyboard and a mouse are illustrated as the input device 4 . However, the input device 4 is not limited to a keyboard and a mouse. For example, the input device 4 may be a touch panel disposed on the display screen of the display device 3 .

[0055] Figure 2 This is a diagram for explaining the principle of light section (triangulation distance measurement). A light projecting unit 11, a light receiving lens 12, and an imaging unit 13 are accommodated inside the housing 10 of the optical displacement meter 1. The light projecting unit 11 has a light source 14 and a light projecting lens 15. For example, the light source 14 is a laser beam emitter, and the light projecting lens 15 may also be composed of a plurality of lenses including a cylindrical lens.

[0056] Light output from the light source 14 is converted into slit light L1 by passing through the light projection lens 15. The housing 10 is provided with a light projection window 16 having light transmission capability for allowing the slit light L1 to pass through. Similarly, the housing 10 is provided with a light receiving window 17 having light transmission capability for allowing the reflected light L2 to pass through.

[0057] The light receiving lens 12 is a lens for converging the reflected light L2 and forming an image on the light receiving surface of the imaging unit 13. The light receiving lens 12 may be a structure including only one lens or a structure including a plurality of lenses. In addition, the light receiving lens 12 may also be a structure including optical components other than lenses (such as optical filters, etc.). The imaging unit 13 is an image sensor having a plurality of photoelectric conversion elements (pixels) arranged in two dimensions. The imaging unit 13 receives the light that has been converged by the light receiving lens.

[0058] like Figure 2 As shown, the optical axis AX2 of the light receiving lens 12 is inclined relative to the light projection axis AX1 of the light projecting unit 11. The light projection axis AX1 of the light projecting unit 11 is consistent with the optical axis of the light source 14. As a result, the reflected light L2 from the height Z1 is imaged at the position V1 in the V direction of the light receiving surface of the imaging unit 13, and the reflected light L2 from the height Z2 is imaged at the position V2 in the V direction of the light receiving surface of the imaging unit 13. In other words, the V direction of the light receiving surface of the imaging unit 13 corresponds to the Z direction of the workpiece W. Although the U direction of the light receiving surface of the imaging unit 13 is not shown in the figure, the U direction corresponds to the X direction of the workpiece W. In other words, the longitudinal direction of the image as the light receiving result output by the imaging unit 13 is the V direction, and the lateral direction is the U direction.

[0059] The light projecting unit 11, the light receiving lens 12, and the imaging unit 13 are rotatable around a rotation axis AX3 along the X direction. The relative positions of the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 are fixed. Figure 2 In the figure, the solid line shows the state of the light projecting unit 11, the light receiving lens 12 and the camera unit 13 before rotating in the counterclockwise direction CCW, and the dotted line shows the state of the light projecting unit 11, the light receiving lens 12 and the camera unit 13 after rotating in the counterclockwise direction CCW.

[0060] The light projecting unit 11, the light receiving lens 12, and the imaging unit 13 can rotate around the rotation axis AX3 along the X direction in a state where the light receiving surface of the imaging unit 13 is tilted relative to the optical axis of the light receiving lens 12 and satisfies Scham's law. Figure 2 In the region R1 indicated by a grid, each cross section through which the optical axis AX1 passes is in focus. That is, even if the height of the workpiece W changes, the optical displacement meter 1 can generate the contour of the workpiece W in focus.

[0061] In addition, the positional relationship between the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 may also be different from Figure 2 The positional relationship shown is reversed.

[0062] In addition, if Figure 3 As shown, the optical displacement meter 1 may also include a reflecting member 18. The reflecting member 18 is disposed on the optical path between the light receiving window 17 and the imaging unit 13, and is used to bend the reflected light L2 and the optical axis AX2 of the light receiving lens 12 back to the light projecting unit 11 side. Thus, a light projecting and light receiving module that integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 can be compactly constructed on a YZ plane extending along the Y direction and the Z direction. Therefore, the moment of inertia of the light projecting and light receiving module that integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 around the rotation axis AX3 can be reduced.

[0063] exist Figure 3In the embodiment, the reflective member 18 is disposed on the optical path between the light receiving lens 12 and the imaging unit 13, but the reflective member 18 may also be disposed on the optical path between the light receiving window 17 and the light receiving lens 12 (for example, see the following description). Figure 8 and Fig. 9 ).

[0064] When the reflective member 18 is disposed on the optical path between the light receiving lens 12 and the imaging unit 13, the reflective member 18 reflects the light focused by the light receiving lens 12, so that the area of ​​the reflective surface of the reflective member 18 can be reduced. When the reflective member 18 is disposed on the optical path between the light receiving window 17 and the light receiving lens 12, the heavy light receiving lens 12 can be arranged close to the rotation axis AX3, thereby increasing the effect of reducing the moment of inertia.

[0065] <Position (calculation of height)>

[0066] Figure 4 This is a diagram for explaining a method of calculating the height of the contour based on the image I1 as the light receiving result output by the imaging unit 13. The slit light L1 has a certain width in the Y direction. Therefore, the width of the spot generated by the reflected light L2 on the light receiving surface of the imaging unit 13 is also as wide as that across a plurality of photoelectric conversion elements.

[0067] Therefore, the optical displacement meter 1 obtains an approximate curve P1 representing the change in brightness value based on the brightness value of each pixel, and calculates the position of the peak in the approximate curve P1 in the V direction. Figure 4 In the figure, the leftmost column is the focus column, and the distribution of the brightness value of the focus column is illustrated (approximate curve P1). The approximate curve P1 is obtained by performing curve fitting on multiple sampling values. Sampling values ​​that are less than the detection threshold are not considered. The position where the peak occurs in the V direction represents the height of the workpiece W. The optical displacement meter 1 obtains the approximate curve P1 at each position (each pixel column) in the U direction, and calculates the position (height) of the peak in the V direction based on the approximate curve P1. By performing this operation processing for each position in the U direction, a contour can be obtained. Such an operation processing can also be called sub-pixel processing.

[0068] In addition, for example, by pre-factory calibration, coordinate transformation conditions (for example, a coordinate transformation table) are generated that represent the correspondence between the UV coordinates and the rotation angle θ and the local coordinates (X, Y, Z), such as represented by (U, V, θ) = (X, Y, Z), and the coordinate transformation conditions are stored in a storage unit (not shown) of the optical displacement meter 1. Therefore, the optical displacement meter 1 can transform the contour in the UV coordinate system into the contour in the XYZ coordinate system based on the rotation angle θ through simple calculations.

[0069] <Function Block>

[0070] Figure 5 1 is a functional block diagram of the optical displacement meter 1. The optical displacement meter 1 includes a light projecting and receiving module 20, a motor 21, and a control unit 22.

[0071] The light projecting and receiving module 20 integrally holds the light projecting unit 11, the light receiving lens 12, and the imaging unit 13. In addition, when the optical displacement meter 1 includes the reflecting member 18, the light projecting and receiving module 20 integrally holds the light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 (in Figure 5 (not shown) are maintained integrally.

[0072] The motor 21 rotates the light projecting unit 11, the light receiving lens 12, and the camera unit 13. More specifically, the motor 21 rotates the light projecting and light receiving module 20. The motor 21 can rotate the light projecting and light receiving module 20 by a direct drive method without configuring an intermediate mechanism such as a speed reducer between the motor 21 and the light projecting and light receiving module 20, or can rotate the light projecting and light receiving module 20 via an intermediate mechanism such as a speed reducer.

[0073] The control unit 22 includes a motor control unit 23, a signal processing unit 24, and a communication unit 25. The control unit 22 controls the motor 21 to rotate the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 in a state satisfying the relationship of Scham's law, so that the slit light L1 is scanned in a direction orthogonal to the X direction. More specifically, the motor control unit 23 controls the motor 21 to rotate the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 in a state satisfying the relationship of Scham's law, and the signal processing unit 24 controls the light projecting unit 11 to irradiate the slit light L1 from the light projecting unit 11.

[0074] The signal processing unit 24 includes a peak detection unit 26, a contour generation unit 27, and a three-dimensional data generation unit 28. The peak detection unit 26 detects the position (peak position) of the peak generating the brightness value in the V direction based on the light receiving result output from the camera unit 13. The contour generation unit 27 generates a contour data by summarizing the heights (zi) at each position (xi) in the X direction of the workpiece W obtained by the peak detection unit 26. The three-dimensional data generation unit 28 generates three-dimensional shape data of the workpiece W based on the contours of the workpiece W with different yi generated by the contour generation unit 27. In addition, at least a part of the peak detection unit 26, the contour generation unit 27, and the three-dimensional data generation unit 28 may be set not in the optical displacement meter 1, but in the control device 2 (refer to Figure 1 )’s interior.

[0075] The communication unit 25 performs wired or wireless communication with the control device 2. For example, the communication unit 25 receives instructions from the control device 2 and transmits the instructions to the control unit 22. In addition, the communication unit 25 transmits the contour data and three-dimensional shape data of the workpiece W generated by the signal processing unit 24 to the control device 2.

[0076] <Motor Configuration>

[0077] Figure 6 and Figure 7 It is a diagram for explaining a first example of the arrangement of the motor 21 . Figure 6 yes Figure 7 A cross-sectional view of the optical displacement meter 1 taken along line BB′ perpendicular to the X direction. Figure 7 yes Figure 6 A cross-sectional view of the optical displacement meter 1 along the XZ plane at line AA′.

[0078] In the first example, the light projecting and receiving module 20 includes a plate-shaped base member 201 extending along a plane perpendicular to the X direction. The light projecting unit 11 , the light receiving lens 12 , the imaging unit 13 , and the reflecting member 18 are mounted on the base member 201 .

[0079] In the first example, the light-projecting and light-receiving module 20 does not overlap with the motor 21 and the accessory parts of the motor 21 in the X direction. The accessory parts of the motor 21 are, for example, encoders that detect the amount of rotation of the rotor of the motor 21. According to the first example of the configuration of the motor 21, it is easy to configure the light-projecting unit 11, the light-receiving lens 12, and the camera unit 13 close to each other. By making the light-projecting unit 11, the light-receiving lens 12, and the camera unit 13 close to each other, the light-projecting and light-receiving module 20 can be compactly configured. Therefore, the moment of inertia of the light-projecting and light-receiving module 20 around the rotation axis AX3 can be reduced.

[0080] In the first example, the control unit 22 does not overlap with the light projecting and receiving module 20 in the X direction, but overlaps with the motor 21 in the X direction.

[0081] Figure 8 and Fig. 9 It is a diagram for explaining a second example of the arrangement of the motor 21 . Figure 8 yes Fig. 9 A cross-sectional view of the optical displacement meter 1 taken along line BB′ perpendicular to the X direction. Fig. 9 yes Figure 8 A cross-sectional view of the optical displacement meter 1 taken along line AA′ perpendicular to the Z direction.

[0082] In the second example, the light projecting and light receiving module 20 includes a base member 201. The base member 201 includes a cylinder extending in the X direction, a cover for blocking one end of the cylinder in the X direction, and a flange extending radially outward from the other end of the cylinder in the X direction. The light projecting unit 11, the light receiving lens 12, the imaging unit 13, and the reflecting member 18 are mounted on the flange of the base member 201.

[0083] In the second example, the light projecting and light receiving module 20 overlaps with at least one of the motor 21 and the accessory of the motor 21 in the X direction. As in the first example, the accessory of the motor 21 is, for example, an encoder that detects the amount of rotation of the rotor of the motor 21. According to the second example of the arrangement of the motor 21, it is easy to arrange the light projecting unit 11 away from the light receiving lens 12 and the imaging unit 13. By arranging the light projecting unit 11 away from the light receiving lens 12 and the imaging unit 13, the scanning range of the slit light L1 can be expanded.

[0084] In the second example, the control unit 22 overlaps with the light-projecting and light-receiving module 20 and the motor 21 in the X direction. In addition, the control unit 22 may be arranged at a position where it does not overlap with the motor 21 in the X direction and overlaps with the motor 21 when viewed along the X direction. In the case where the control unit 22 is arranged at a position where it does not overlap with the motor 21 in the X direction and overlaps with the motor 21 when viewed along the X direction, the control unit 22 may or may not overlap with the light-projecting and light-receiving module 20 and the motor 21 in the X direction.

[0085] <Processing Flow>

[0086] Fig.10 1 is a diagram showing the processing flow of the measurement operation of the optical displacement measuring system 100. When the input device 4 receives a user input for instructing the start of measurement, the measurement starts. Fig.10 The processing flow.

[0087] First, in step S1, the light projecting unit 11 starts irradiating the slit light L1. In the next step S2, the motor control unit 23 starts rotating the motor 21. In addition, the processing of step S1 and the processing of step S2 can also be performed simultaneously. The motor control unit 23 can also rotate the motor before executing step S1 to move the light projecting and receiving module 20 to a specified scanning start position. Through the processing of step S1 and step S2, the scanning of the slit light L1 starts.

[0088] In the next step S3, the motor control unit 23 determines whether the rotation amount (rotation angle) of the motor 21 from the start of rotation is smaller than a threshold value. If the rotation amount of the motor 21 from the start of rotation is smaller than the threshold value, the determination process of step S3 is continued, and the scanning of the slit light L1 is continued.

[0089] When the rotation amount of the motor 21 from the start of rotation reaches the threshold value, the process proceeds to step S4. In addition, the threshold value is the rotation amount calculated based on the measurement range. The measurement range is set by default. When the measurement range is changed by the user, the control unit 22 (for example, the signal processing unit 24) calculates the threshold value of the rotation amount based on the changed measurement range.

[0090] In step S4, the motor control unit 23 stops the rotation of the motor 21. In the next step S5, the light projecting unit 11 stops the irradiation of the slit light L1. The processing of step S4 and the processing of step S5 may be performed simultaneously. Through the processing of step S4 and step S5, the scanning of the slit light L1 ends.

[0091] In the next step S6, the outline generation unit 27 generates an outline. Alternatively, the outline generation unit 27 may start generating an outline while the slit light L1 is scanning.

[0092] In the next step S7 , the three-dimensional data generating unit 28 generates three-dimensional data.

[0093] In the next step S8, the display device 3 displays the measurement result. The measurement result is, for example, a cross-sectional view of the workpiece W based on the contour, a three-dimensional image of the workpiece W based on the three-dimensional data, etc. When the processing of step S8 is completed, Fig.10 The processing flow ends.

[0094] The optical displacement meter 1 has a measurement period and a non-measurement period, wherein during the measurement period, the light-emitting and light-receiving module 20 is rotated at a substantially constant speed in the first rotation direction (counterclockwise CCW) or the second rotation direction (clockwise CW) to perform the measurement operation, and during the non-measurement period, the rotation direction of the light-emitting and light-receiving module 20 is switched without performing the measurement operation. During the measurement period in which the measurement operation is performed, the motor rotates the light-emitting and light-receiving module 20 at a substantially constant speed. Regarding the period of switching the rotation direction, since deceleration and acceleration need to be considered and the calculation of the correlation between the peak position in the V direction and the rotation angle becomes complicated, it is preferably set as a non-measurement period.

[0095] <Bandpass filter>

[0096] The light projecting and receiving module 20 includes a bandpass filter 30 (see the following description) that allows light in the first wavelength range included in the slit light L1 to pass through. Figure 11 to Figure 15). The light receiving window 17 allows light of a wavelength range that includes the first wavelength range and is wider than the first wavelength range to pass through. The reflected light L2 that has passed through the light receiving window 17 is incident on the imaging unit 13 through the band pass filter 30. According to such a structure, the incident angle of the reflected light L2 with respect to the band pass filter 30 is not affected by the change in the angle formed between the optical axis AX2 of the light receiving lens 12 and the light receiving window 17. As a result, the incident angle of the reflected light of the slit light to the band pass filter does not change, so that the intrusion prevention performance of the interfering light in the band pass filter 30 can be suppressed from being deteriorated.

[0097] Fig.16 1 is a diagram showing an example of the relationship between the wavelength range W1 of the slit light emitted from the light projecting unit 11, the transmission characteristic 101 of the bandpass filter 30, and the transmission characteristic 102 of the light receiving window 17 when the light source 14 is a blue laser beam emitter. The transmittance of the bandpass filter 30 in a prescribed wavelength range including the wavelength range of the slit light L1 is higher than the transmittance of the bandpass filter 30 outside the prescribed wavelength range. In addition, the wavelength range of light that can pass through the bandpass filter 30 at a pass rate of 50% or more is narrower than the wavelength range of light that can pass through the light receiving window 17 at a pass rate of 50% or more.

[0098] The light receiving window 17 may be a structure not including an optical filter, or a structure including an optical filter that allows light to pass through the optical filter at a rate of 50% or more, and has a wavelength range wider than the wavelength range of light that can pass through the bandpass filter 30 at a rate of 50% or more. The light receiving window 17 may also be composed of a colored glass filter, for example.

[0099] The bandpass filter 30 is disposed, for example, at a position within the light-projecting and light-receiving module 20 that is substantially perpendicular to the optical axis AX2 of the light-receiving lens 12 regardless of the rotation of the light-projecting and light-receiving module 20. According to this arrangement, it is not necessary to design the bandpass filter 30 in consideration of changes in the optical characteristics when light is not incident perpendicularly to the bandpass filter 30 relative to when light is incident perpendicularly to the bandpass filter 30.

[0100] The bandpass filter 30 may also be, for example, Fig.11 As shown, it is provided on the surface of the light receiving lens 12.

[0101] When the light receiving lens 12 includes a plurality of lenses, the band pass filter 30 may also be, for example, Fig.12 As shown in FIG. 1 , it is arranged inside the light receiving lens 12. Fig.12In the embodiment of the present invention, the bandpass filter 30 is held by a flat holding member 31. The holding member 31 may have the same light transmittance as the light receiving window 17, for example. The bandpass filter 30 is composed of a plurality of optical films stacked on the light receiving lens 12 or the holding member 31. In addition, the bandpass filter 30 may be provided on the surface of each lens of the plurality of lenses. In this case, a plurality of bandpass filters can be used, so the effect of the bandpass filter can be improved as a whole.

[0102] The bandpass filter 30 may also be, for example, Fig.13 and Fig.14 As shown in FIG. 1 , the cover glass 33 is provided to cover the light receiving surface 131 of the imaging unit 13. The cover glass 33 may be Fig.13 As shown in FIG. 1 , the optical axis AX2 of the light receiving lens 12 may be arranged perpendicularly. Fig.14 As shown, the bandpass filter 30 is arranged parallel to the light receiving surface 131 of the imaging unit 13. The bandpass filter 30 is composed of a plurality of optical films stacked on a cover glass 33. Generally, the cover glass 33 is smaller than the light receiving lens 12 and the reflective member 18, so the cost can be reduced.

[0103] The bandpass filter 30 may also be, for example, Fig.15 The bandpass filter 30 is provided on the reflective member 18 as shown. The bandpass filter 30 is composed of a plurality of optical films stacked on the reflective member 18. The angle between the reflective member 18 and the imaging unit 13 is relatively large, so even if multiple reflections occur between the optical films, the possibility of incident on the imaging unit 13 can be suppressed. The light projection and light receiving module 20 may also include a plurality of bandpass filters 30. In this case, any of the above-mentioned configurations may be combined.

[0104] By rotating the light-projecting and light-receiving module 20, the angle formed between the optical axis AX2 of the light-receiving lens 12 and the light-receiving window 17 changes within a specified angle range. On the other hand, regardless of the rotation angle of the light-projecting and light-receiving module 20, the light-projecting and light-receiving module 20 maintains the band-pass filter 30 in a manner such that the angle formed between the optical axis AX2 of the light-receiving lens 12 and the band-pass filter 30 is constant. The light focused by the light-receiving lens is incident on the band-pass filter at a constant angle, so that the reflected light of the slit light can be suppressed from being filtered by the band-pass filter. In more detail, the light-projecting and light-receiving module 20 indirectly maintains the band-pass filter 30 via the components included in the light-projecting and light-receiving module 20 (for example, the light-receiving lens 12, the holding member 31, the cover glass 33, the reflecting member 18, etc.). The above-mentioned specified angle range can be, for example, a range including 85 degrees to 95 degrees. In addition, the light projecting and light receiving module 20 further includes a base member 201, to which the light projection axis of the light projecting unit 11, the light receiving lens 12, and the imaging unit 13 are fixed in such a manner that the relationship of Scham's law is satisfied regardless of the rotation angle in the measurement operation, and the band pass filter 30 is fixed in such a manner that the relative position with the light receiving lens 12 is fixed, and the reflected light obtained by the slit light reflected by the workpiece located in the focal plane in the relationship of Scham's law enters the band pass filter 30 at a constant incident angle regardless of the rotation angle. Thus, a contour image based on the reflected light of the focused slit light can be obtained while suppressing the influence of disturbance light.

[0105] In addition, for example, when the bandpass filter 30 is provided on the surface of the light receiving lens 12, the bandpass filter 30 is not arranged along a plane. When the bandpass filter 30 is not arranged along a plane, the angle formed between the virtual plane in contact with the center of the bandpass filter 30 and the optical axis AX2 of the light receiving lens 12 is the angle formed between the optical axis AX2 of the light receiving lens 12 and the bandpass filter 30.

[0106] Preferably, the angle formed between the optical axis AX2 of the light receiving lens 12 and the band pass filter 30 is included in the above-mentioned specified angle range. More preferably, the angle formed between the optical axis AX2 of the light receiving lens 12 and the band pass filter 30 is an angle substantially at the center of the above-mentioned specified angle range. It is further preferred that the optical axis AX2 of the light receiving lens 12 is substantially orthogonal to the band pass filter 30. This is because, in the case where the optical axis AX2 of the light receiving lens 12 is substantially orthogonal to the band pass filter 30, there is no need to consider the design of the change in the optical characteristics of the band pass filter 30 when the light is not incident perpendicularly to the band pass filter 30 relative to when the light is incident perpendicularly to the band pass filter 30.

[0107] <Colored Glass Filters>

[0108] The light receiving window 17 may also be formed of a colored glass filter that allows light in the first wavelength range included in the slit light L1 to pass through. In this case, the optical displacement meter 1 may be configured to not include the above-mentioned bandpass filter 30. In addition, in general, a bandpass filter (optical thin film filter) has a more sensitive transmission characteristic than a colored glass filter, and can narrow the wavelength range with high transmittance, so the influence of interfering light can be further suppressed by further providing a bandpass filter 30.

[0109] Regardless of the change in the incident angle of the reflected light L2 with respect to the light receiving window 17 caused by the rotation of the light projecting and light receiving module 20, the colored glass filter constituting the light receiving window 17 has a substantially constant transmission characteristic for light in a predetermined wavelength range. Therefore, regardless of the angle formed between the light receiving window 17 and the optical axis AX2 of the light receiving lens 12, the optical characteristic of the colored glass filter for light in the first wavelength range including the wavelength range of the slit light L1 is substantially constant. Therefore, it is possible to suppress the deterioration of the intrusion prevention performance of the disturbing light due to the change in the angle formed between the light receiving window 17 and the optical axis AX2 of the light receiving lens 12.

[0110] The colored glass filter constituting the light receiving window 17 allows infrared light to pass through. In other words, the colored glass filter constituting the light receiving window 17 has low performance in preventing the intrusion of infrared interference light. However, since the general imaging unit 13 has low sensitivity to infrared light, the low performance in preventing the intrusion of infrared interference light does not become a big problem.

[0111] <Conclusion>

[0112] The various embodiments described above will be generally described below.

[0113] For example, a first optical displacement meter disclosed in the present specification includes: a light-projecting and light-receiving module having a light-projecting portion for irradiating slit light extending in the X direction, a light-receiving lens for converging reflected light obtained by reflecting the slit light from a workpiece, a band-pass filter whose relative position to the light-receiving lens is fixed, and an imaging portion for receiving light converged by the light-receiving lens; a motor for integrally rotating the light-projecting and light-receiving module; a housing for accommodating the light-projecting and light-receiving module and provided with a light-receiving window for transmitting the reflected light; and a control portion for controlling the motor to scan the slit light in a direction orthogonal to the X direction, wherein the light-receiving window transmits light of a predetermined wavelength range including the wavelength range of the slit light regardless of the rotation angle of the light-projecting and light-receiving module in a measuring operation, and the band-pass filter selectively transmits or reflects the reflected light of the slit light among the light transmitted through the light-receiving window so as to cause the reflected light to enter the imaging portion (first structure).

[0114] In the optical displacement meter of the above-mentioned first structure, it can also be the following structure: through the rotation of the light-projecting and light-receiving module, the angle formed by the optical axis of the light-receiving lens and the light-receiving window changes within a specified angle range, and on the other hand, regardless of the rotation angle of the light-projecting and light-receiving module, the angle formed by the optical axis of the light-receiving lens and the bandpass filter is constant (second structure).

[0115] In the optical displacement meter of the above-mentioned first structure or second structure, it can also be the following structure: the light projecting and light receiving module also has a supporting member, the light projection axis of the light projecting part, the light receiving lens and the camera part are fixed to the supporting member in a manner that satisfies the relationship of Scham's law regardless of the rotation angle in the measuring action, and the bandpass filter is fixed to the supporting member in a manner that the relative position with the light receiving lens is fixed, and the reflected light obtained by reflecting the slit light from the workpiece located in the focal plane in the relationship of Scham's law is incident on the bandpass filter at a constant incident angle regardless of the rotation angle (third structure).

[0116] In the optical displacement meter of any one of the above-mentioned structures 1 to 3, the following structure can also be adopted: the bandpass filter is arranged in the light-projecting and light-receiving module at a position substantially orthogonal to the optical axis of the light-receiving lens regardless of the rotation of the light-projecting and light-receiving module, and the reflected light passing through the light-receiving window passes through the bandpass filter, thereby the light in the wavelength range of the slit light is incident on the imaging unit (structure 4).

[0117] In the optical displacement meter of any one of the above-mentioned structures 1 to 4, the following structure may also be adopted: the imaging unit has a plurality of pixels arranged in two dimensions and a cover glass for protecting the plurality of pixels, and the bandpass filter is composed of a plurality of optical films stacked on the cover glass (structure 5).

[0118] In the optical displacement meter of the above-mentioned fifth structure, it can also be the following structure: regardless of the rotation of the light projection and light receiving module, the cover glass and the bandpass filter are approximately orthogonal to the optical axis of the light receiving lens and are arranged at an angle relative to the light receiving surface of the multiple pixels (sixth structure).

[0119] In the optical displacement meter of any one of the above-mentioned structures 1 to 6, the following structure may also be adopted: the light receiving lens includes a plurality of lenses, the bandpass filter is arranged on the surface of each lens among the plurality of lenses, and the light passing through the light receiving window passes through the bandpass filter arranged on the surface of each lens in sequence, thereby the reflected light of the slit light is selectively incident on the imaging unit (structure 7).

[0120] In the optical displacement meter of any one of the above-mentioned structures 1 to 7, the following structure can also be adopted: the light projecting and receiving module also has a reflecting component whose relative position with the light receiving lens is fixed, the reflecting component is arranged on the optical path between the light receiving window and the camera unit, the bandpass filter is composed of a plurality of optical films stacked on the reflecting component, and the reflecting component and the bandpass filter selectively reflect the reflected light of the slit light among the light that passes through the light receiving window and is incident on the bandpass filter and the reflecting component at a specified angle toward the camera unit (structure 8).

[0121] In the optical displacement meter of the above-mentioned structure 8, the following structure may also be adopted: the light-projecting and light-receiving module also has a supporting member, and the light-projecting axis of the light-projecting unit, the light-receiving lens, the reflecting member and the camera unit are fixed to the supporting member in a manner that satisfies the relationship of Scham's law regardless of the rotation angle in the measuring action (structure 9).

[0122] In the optical displacement meter of any one of the above-mentioned structures 1 to 9, the following structure can also be adopted: the light receiving window is composed of a colored glass filter, the colored glass filter has a substantially constant transmittance within the specified wavelength range regardless of changes in the incident angle, and the transmittance within the first wavelength range including the wavelength range of the slit light is higher than the transmittance within the specified wavelength range outside the first wavelength range, regardless of the rotation angle of the light projecting and receiving module in the measuring action, the colored glass filter transmits the light within the first wavelength range, and the bandpass filter selectively passes or reflects the reflected light of the slit light among the light passing through the colored glass filter so that the reflected light is incident on the imaging unit (the 10th structure).

[0123] For example, the second optical displacement meter disclosed in this specification comprises: a light-projecting and light-receiving module, which has a light-projecting portion for irradiating slit light extending in the X direction, a light-receiving lens for converging reflected light obtained by reflecting the slit light off a workpiece, and a camera portion for receiving the light converged by the light-receiving lens; a motor for rotating the light-projecting and light-receiving module as a whole; a housing for accommodating the light-projecting and light-receiving module and provided with a light-receiving window for transmitting the reflected light; and a control portion for controlling the motor to scan the slit light in a direction orthogonal to the X direction, wherein the The light receiving window is composed of a colored glass filter, and the colored glass filter has a substantially constant transmittance within a specified wavelength range including the wavelength range of the slit light regardless of changes in the incident angle, and the transmittance within the wavelength range of the slit light is higher than the transmittance within the specified wavelength range outside the wavelength range of the slit light. Regardless of the rotation angle of the light projection and light receiving module in the measuring action, the colored glass filter selectively allows the reflected light of the slit light to pass through so that the reflected light is incident on the camera unit (the 11th structure).

[0124] <Other Modifications>

[0125] In addition, in addition to the above-mentioned embodiments, various technical features disclosed in this specification can be subjected to various changes within the scope of the main purpose of the technical design. That is, the above-mentioned embodiments should be considered to be illustrative rather than restrictive in all aspects, and it should be understood that the protection scope of the utility model is defined by the claims, including all changes within the meaning and scope equivalent to the claims.

[0126] Description of Reference Numerals

[0127] 1: optical displacement meter; 2: control device; 3: display device; 4: input device; 10: housing; 11: light-projecting unit; 12: light-receiving lens; 13: camera unit; 131: light-receiving surface; 14: light source; 15: light-projecting lens; 16: light-projecting window; 17: light-receiving window; 18: reflecting component; 20: light-projecting and light-receiving module; 201: base component; 21: motor; 22: control unit; 23: motor control unit; 24: signal processing unit; 25: communication unit; 26: peak detection unit; 27: contour generation unit; 28: three-dimensional data generation unit; 30: bandpass filter; 31: holding component; 33: cover glass; 100: optical displacement measuring system; AX1: light-projecting axis; AX2: optical axis; I1: image; AX3: rotation axis; R1: area; W: workpiece.

Claims

1. An optical displacement meter, characterized in that: have: A light projecting and light receiving module, comprising a light projecting unit for irradiating slit light extending in the X direction, a light receiving lens for converging reflected light obtained by reflecting the slit light off a workpiece, a band pass filter fixed in position relative to the light receiving lens, and an imaging unit for receiving the light converging through the light receiving lens; A motor, which rotates the light-projecting and light-receiving modules integrally; a housing, which accommodates the light-projecting and light-receiving module and is provided with a light-receiving window for transmitting the reflected light; and a control unit that controls the motor to scan the slit light in a direction orthogonal to the X direction, Wherein, regardless of the rotation angle of the light-projecting and light-receiving module during the measuring action, the light-receiving window allows light of a specified wavelength range including the wavelength range of the slit light to pass through, and the bandpass filter allows the reflected light of the slit light among the light passing through the light-receiving window to selectively pass through or reflect the reflected light so that the reflected light is incident on the camera unit.

2. The optical displacement meter according to claim 1, characterized in that: By rotating the light-projecting and light-receiving module, the angle formed between the optical axis of the light-receiving lens and the light-receiving window changes within a specified angle range. On the other hand, regardless of the rotation angle of the light-projecting and light-receiving module, the angle formed between the optical axis of the light-receiving lens and the bandpass filter is constant.

3. The optical displacement meter according to claim 1, characterized in that: The light-projecting and light-receiving module further comprises a supporting member, the light-projecting axis of the light-projecting unit, the light-receiving lens, and the camera unit are fixed to the supporting member in such a manner that the relationship of Scham's law is satisfied regardless of the rotation angle in the measuring operation, and the band-pass filter is fixed to the supporting member in such a manner that the relative position with the light-receiving lens is fixed. Regardless of the rotation angle, the reflected light obtained by the slit light being reflected by the workpiece located at the focal plane in the relationship of the Scham's law enters the bandpass filter at a constant incident angle.

4. The optical displacement meter according to claim 1, characterized in that: The bandpass filter is arranged in the light projecting and receiving module at a position substantially orthogonal to the optical axis of the light receiving lens regardless of the rotation of the light projecting and receiving module. The reflected light having passed through the light receiving window passes through the bandpass filter, whereby the light in the wavelength range of the slit light enters the imaging unit.

5. The optical displacement meter according to claim 1, characterized in that: The imaging unit includes a plurality of pixels arranged two-dimensionally and a cover glass for protecting the plurality of pixels. The bandpass filter is composed of a plurality of optical thin films stacked on the cover glass.

6. The optical displacement meter according to claim 5, characterized in that: Regardless of the rotation of the light projecting and receiving module, the cover glass and the bandpass filter are arranged substantially orthogonal to the optical axis of the light receiving lens and inclined with respect to the light receiving surfaces of the plurality of pixels.

7. The optical displacement meter according to claim 1, characterized in that: The light receiving lens includes a plurality of lenses, and the bandpass filter is arranged on the surface of each lens in the plurality of lenses. The light transmitted through the light receiving window sequentially passes through the bandpass filter provided on the surface of each of the lenses, whereby the reflected light of the slit light selectively enters the imaging unit.

8. The optical displacement meter according to claim 1, characterized in that: The light projecting and receiving module further comprises a reflective member whose relative position with the light receiving lens is fixed, and the reflective member is arranged on the optical path between the light receiving window and the imaging unit. The bandpass filter is composed of a plurality of optical films stacked on the reflective member. The reflecting member and the bandpass filter selectively reflect the reflected light of the slit light among the light that is incident on the bandpass filter and the reflecting member at a predetermined angle after passing through the light receiving window toward the imaging unit.

9. The optical displacement meter according to claim 8, characterized in that: The light projecting and receiving module further includes a supporting member to which a light projection axis of the light projecting unit, the light receiving lens, the reflecting member, and the imaging unit are fixed so as to satisfy the relationship of Scham's law regardless of the rotation angle in the measuring operation.

10. The optical displacement meter according to claim 1, characterized in that: The light receiving window is composed of a colored glass filter, the colored glass filter has a substantially constant transmittance within the specified wavelength range regardless of changes in the incident angle, and the transmittance within a first wavelength range including the wavelength range of the slit light is higher than the transmittance within the specified wavelength range outside the first wavelength range, Regardless of the rotation angle of the light-projecting and light-receiving module in the measuring action, the colored glass filter allows the light in the first wavelength range to pass through, and the bandpass filter allows the reflected light of the slit light in the light that has passed through the colored glass filter to selectively pass through or reflect the reflected light so that the reflected light is incident on the camera unit.

11. An optical displacement meter, characterized in that: have: a light projecting and receiving module, comprising a light projecting unit for irradiating slit light extending in the X direction, a light receiving lens for converging reflected light obtained by reflecting the slit light off a workpiece, and an imaging unit for receiving the light converging through the light receiving lens; A motor, which rotates the light-projecting and light-receiving modules integrally; a housing, which accommodates the light-projecting and light-receiving module and is provided with a light-receiving window for transmitting the reflected light; and a control unit that controls the motor to scan the slit light in a direction orthogonal to the X direction, The light receiving window is composed of a colored glass filter, which has a substantially constant transmittance within a specified wavelength range including the wavelength range of the slit light regardless of changes in the incident angle, and has a transmittance within the wavelength range of the slit light that is higher than a transmittance within the specified wavelength range outside the wavelength range of the slit light. Regardless of the rotation angle of the light projecting and receiving module during the measuring operation, the colored glass filter selectively passes the reflected light of the slit light and allows the reflected light to enter the imaging unit.

Images