Optical displacement meter

Abstract

An optical displacement meter is provided, which can easily adjust the position relative to a workpiece without reducing the measurement accuracy of the contour. A camera (100) includes a laser projector (110), an LED projector (120), a light receiving lens (132), a light receiver (131), and a processor (200). The laser projector (110) emits measurement light to the workpiece (W). The LED projector (120) emits uniform observation light to the workpiece (W). The light receiving lens (132) converges the reflected light of the measurement light and the reflected light of the observation light reflected back from the workpiece (W). The light receiver (131) has a light receiving surface composed of a plurality of light receiving elements arranged in two dimensions. The laser projector (110), the light receiver (131), and the light receiving lens (132) are arranged so that a plane containing the light receiving surface and a plane containing the main surface of the light receiving lens (132) satisfy the Scheimpflug condition relative to the light projection axis of the laser projector (110). This enables generation of observation image data showing an observation image in which the focus of the light receiver (131) is relatively consistent with an area near the measurement position irradiated with measurement light during measurement.

Description

Technical Field

[0001] The present invention relates to an optical displacement meter using a light section method for measuring the contour of a measurement object. Background Art

[0002] Optical displacement meters using the light section method can be used to measure the contour of a measurement object (hereinafter referred to as a "workpiece"). For example, WO 2001 / 073375 describes an optical displacement meter comprising a laser diode and a two-dimensional charge-coupled device (CCD). The laser diode emits a linear measurement light beam toward the workpiece, and the reflected light of the measurement light reflected from the workpiece is received by the CCD. The CCD generates a video signal and, based on this video signal, measures the height displacement of a desired position on the workpiece.

[0003] To accurately measure the desired position on a workpiece, the user needs to adjust the relative position between the optical displacement meter and the workpiece so that the irradiation position of the measurement light is completely aligned with the measurement position on the workpiece. However, when the optical displacement meter and the workpiece are close to each other, it is difficult to visually observe the irradiation position of the measurement light.

[0004] In the optical displacement meter described in WO 2001 / 073375, the CCD is physically or optically directed toward the workpiece to obtain a direct image of the workpiece.

[0005] This structure provides a completely clear image of the workpiece and facilitates positional adjustment of the optical displacement meter. However, if the workpiece has a portion at the measurement location whose height differs significantly from that of other portions, it is difficult to obtain an oblique image of each portion with the CCD focused on the measurement location. In this case, the displacement measurement accuracy varies depending on the height of the measurement location, making it difficult to measure the workpiece's contour with high precision. Summary of the Invention

[0006] An object of the present invention is to provide an optical displacement meter that can easily adjust its position relative to a workpiece without reducing the measurement accuracy of the profile.

[0007] The present invention provides an optical displacement meter using a light section method for measuring the contour of a measurement object. The optical displacement meter includes a laser projector, an LED projector, a light receiving lens, a light receiver, and a processor. The laser projector has a first light projection axis and is configured to emit a strip of laser light extending in one direction or a point of laser light for scanning in the one direction as measurement light to the measurement object. The LED projector is configured to emit uniform light as observation light to the measurement object. The light receiving lens is configured to converge reflected light of the measurement light and reflected light of the observation light reflected from the measurement object. The light receiver has a light receiving surface and is configured to receive the light converged by the light receiving lens and output a received light quantity distribution. The light receiving surface is composed of a plurality of light receiving elements arranged in two dimensions. The processor is configured to, during measurement, execute processing for generating contour data based on the received light quantity distribution of the measurement light output by the light receiver, and execute processing for generating observation image data based on the received light quantity distribution of the observation light output by the light receiver. The contour data shows the contour of the measurement object. The observation image data shows an image of the measurement object irradiated by the observation light as an observation image. The laser projector, the light receiver, and the light receiving lens are arranged so that a plane containing the light receiving surface and a plane containing the main surface of the light receiving lens satisfy a Scheimpflug condition with respect to the first light projection axis, thereby generating observation image data showing an observation image in which a focal point of the light receiver relatively coincides with an area near a measurement position irradiated by the measurement light during measurement.

[0008] In this optical displacement meter, a laser projector emits a strip of laser light extending in one direction or a spot of laser light for scanning in one direction as measurement light toward the measurement object. The measurement light reflected from the measurement object is focused by a light-receiving lens. A light receiver receives the measurement light focused by the light-receiving lens at a light-receiving surface composed of multiple light-receiving elements arranged two-dimensionally. The light receiver outputs a distribution of the amount of received light. Profile data representing the outline of the measurement object is generated based on the distribution of the amount of received light output by the light receiver during measurement.

[0009] The LED projector emits uniform light as observation light onto the measurement object. The observation light reflected from the measurement object is focused by a light-receiving lens. A light receiver receives the observation light focused by the light-receiving lens at a light-receiving surface and outputs a received light quantity distribution. Observation image data is generated based on the received light quantity distribution of the observation light output by the light receiver. The observation image data shows an image of the measurement object illuminated by the observation light as an observation image.

[0010] Under these conditions, the laser projector, light receiver, and light receiving lens are arranged so that the plane containing the light receiving surface of the light receiver and the plane containing the main surface of the light receiving lens satisfy the Scheimpflg condition relative to the first light projection axis of the laser projector. This ensures that the focal point of the light receiver is relatively consistent with the area near the measurement position illuminated by the measuring light during measurement, even when the height of one part of the measurement object greatly differs from the height of other parts. As a result, profile data is generated with high accuracy.

[0011] Furthermore, observed image data is generated, showing an observed image in which the focal point of the light receiver relatively coincides with the area near the measurement position illuminated by the measurement light during measurement. Consequently, the observed image clearly shows the measurement position on the measurement object measured by the measurement light. This facilitates the user's adjustment of the position of the optical displacement meter relative to the measurement object by adjusting the position of the optical displacement meter or the measurement object so that the desired portion of the measurement object clearly appears in the observed image. As a result, the position of the optical displacement meter relative to the measurement object can be easily adjusted without compromising the measurement accuracy of the contour.

[0012] The processor may be configured to control the laser projector and the LED projector so as to simultaneously emit the measurement light and the observation light. The processor may also be configured to generate observation image data showing an observation image in which a bright line of the measurement light is superimposed on a measurement position on the measurement object at which the measurement light is irradiated.

[0013] In this case, the measurement position on the measurement object, where the measurement light is irradiated, clearly appears in the observed image as a bright line. This enables the user to more easily and accurately adjust the position of the optical displacement meter relative to the measurement object by adjusting the position of the optical displacement meter or the measurement object so that the bright line will overlap with the desired portion of the measurement object in the observed image.

[0014] The processor may be configured to control the laser projector and the LED projector so as to alternately emit the measurement light and the observation light. The processor may also be configured to alternately execute processing for generating measurement image data based on a received light amount distribution of the measurement light output by the light receiver and processing for generating the observation image data. The measurement image data shows an image of the measurement object illuminated by the measurement light as a measurement image.

[0015] In this case, a bright line of measurement light appears in the measurement image. This allows the user to adjust the position of the optical displacement meter or the measurement object while viewing the bright line of measurement light in the measurement image and observing the measurement object in the image. This allows precise adjustment of the position of the optical displacement meter relative to the measurement object.

[0016] The processor may be configured to automatically switch between the measurement image and the observation image to display the image. This allows the user to adjust the position of the optical displacement meter or the measurement object while viewing the automatically switched and displayed measurement image and observation image, so that the bright line in the measurement image overlaps with a desired portion of the measurement object in the observation image. This makes it easier and more accurate to adjust the position of the optical displacement meter relative to the measurement object.

[0017] The processor may be configured to combine the measurement image data with the observation image data and display an observation image showing the bright line of measurement light superimposed on a measurement position on the measurement object illuminated by the measurement light. This allows a user to adjust the position of the optical displacement meter or the measurement object so that the bright line in the observation image overlaps a desired portion of the measurement object. This makes it easier and more accurate to adjust the position of the optical displacement meter relative to the measurement object.

[0018] The processor may be configured to control the laser projector and the LED projector so that the measurement light and the observation light are alternately emitted during an exposure period of the light receiver. The processor may also be configured to generate observation image data showing an observation image in which a bright line of the measurement light is superimposed on a measurement position on the measurement object at which the measurement light is irradiated.

[0019] In this case, the measurement position on the measurement object, where the measurement light is irradiated, clearly appears in the observed image as a bright line. This enables the user to more easily and accurately adjust the position of the optical displacement meter relative to the measurement object by adjusting the position of the optical displacement meter or the measurement object so that the bright line will overlap with the desired portion of the measurement object in the observed image.

[0020] The optical displacement meter may further include an exclusive control circuit configured to prohibit simultaneous emission of the measurement light and the observation light.

[0021] In some cases, it may be desirable to limit the intensity of light emitted from the optical displacement meter so as not to exceed a predetermined upper limit. The above structure prohibits the simultaneous emission of measurement light and observation light by using an exclusive control circuit. Thus, when the upper limit is set to the intensity of the measurement light, the intensity of the light emitted from the optical displacement meter does not exceed the upper limit. Thus, the intensity of the measurement light can be maintained at the upper limit. This prevents a decrease in processing efficiency due to insufficient measurement light intensity.

[0022] In a housing having an interior space for accommodating the laser projector, the LED projector, the light-receiving lens, and the light receiver, the LED projector may have a second light-projection axis parallel to the first light-projection axis of the laser projector. The housing may include a first surface, a second surface, a measurement window, an observation window, and a light-receiving window. The first surface may be perpendicular to the first and second light-projection axes. The second surface may be arranged in a recessed portion that is recessed from the first surface toward the interior space, at an angle relative to the first surface. The measurement window may be provided on the first surface and configured to transmit measurement light emitted from the laser projector to the measurement object. The observation window may be provided on the first surface and configured to transmit observation light emitted from the LED projector to the measurement object. The light-receiving window may be provided on the second surface and configured to transmit reflected light of the measurement light and reflected light of the observation light reflected from the measurement object. This makes it possible to accommodate the laser projector, LED projector, and camera unit in a compact space while satisfying the Scheimpflug condition.

[0023] The observation window may be provided at a position closer to the light receiving window than the measurement window. This prevents the housing from having a large size in the direction in which the observation window, the measurement window, and the light receiving window are arranged.

[0024] The optical displacement meter may further include a bandpass filter disposed on the optical path of light reflected from the measurement object. The laser projector may be configured to emit measurement light having a wavelength of 400 nm to 480 nm. The LED projector may be configured to emit observation light having a wavelength within a range including the wavelength of the measurement light. The transmittance of the bandpass filter within the wavelength range of the measurement light may be higher than the transmittance of the bandpass filter outside the wavelength range of the measurement light.

[0025] In this case, the bandpass filter transmits measurement light and observation light components with wavelengths approximately equal to the measurement light's, but blocks measurement light components with other wavelengths and ambient light. This allows for accurate generation of profile data and observation image data. Furthermore, measurement light with a wavelength of 400 nm or greater allows users to easily visually identify the measurement light, improving the usability of the optical displacement meter. Furthermore, measurement light with a wavelength of 480 nm or less enables highly accurate generation of profile data.

[0026] The processor may be configured to synthesize the measurement image data and the outline data to generate composite image data showing a first composite image in which a bright line of measurement light is superimposed on the outline. The processor may also be configured to switch between the first composite image and the observed image in response to a user instruction to display the image. In this case, the user can easily determine whether the measurement light is irradiating the desired portion of the measurement object by viewing the outline in the first composite image and the measurement position on the measurement object measured by the measurement light in the observed image.

[0027] The processor may be configured to combine the outline data with the observed image data to display a second composite image including the outline superimposed on the observed image. In this case, the user can easily recognize whether the measurement light is irradiated on a desired portion of the measurement object by viewing the observed image and the outline in the second composite image.

[0028] The present invention facilitates the position adjustment of the optical displacement meter relative to the measurement object without reducing the measurement accuracy of the contour. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a block diagram showing the structure of an optical displacement meter according to a first embodiment;

[0030] Figure 2 It shows Figure 1 A stereoscopic diagram of the appearance of the camera in FIG;

[0031] Figure 3 yes Figure 1 Bottom view of the camera in ;

[0032] Figure 4 Is used to illustrate Figure 1 FIG. 4 is a diagram showing the configuration of the laser projector, LED projector, and camera unit;

[0033] Figure 5 Is used to illustrate Figure 1 FIG. 4 is a diagram showing the configuration of the laser projector, LED projector, and camera unit;

[0034] Figure 6 An example of a transmission wavelength band of an optical filter is shown;

[0035] Figure 7 It is a stereoscopic image of the appearance of the camera and the workpiece;

[0036] Figure 8 shows the relationship between the irradiation position of the measurement light on the surface of the workpiece and the incident position of the light at the light receiver;

[0037] Figure 9shows the relationship between the irradiation position of the measurement light on the surface of the workpiece and the incident position of the light at the light receiver;

[0038] Figure 10 shows the distribution of the amount of received light at the light receiving surface of the light receiver;

[0039] Figure 11 Show Figure 10 Waveform data of a pixel array in ;

[0040] Figure 12 Show Figure 10 All peak positions of the received light quantity distribution in ;

[0041] Figure 13 Shown based on Figure 12 The profile data generated by the peak position of

[0042] Figure 14 An example of a screen displayed on a display is shown;

[0043] Figure 15 An example of a screen displayed on a display is shown;

[0044] Figure 16 Another display example of the image display area is shown;

[0045] Figure 17 Another display example of the image display area is shown;

[0046] Figure 18 shows a measurement image based on the measurement image data generated by the measurement image generation unit;

[0047] Figure 19 shows an observation image based on the observation image data generated by the observation image generation unit;

[0048] Figure 20 is the timing diagram of the control pulses to be applied to the camera;

[0049] Figure 21 An example of an exclusive control circuit is shown;

[0050] Figure 22 Another example of a housing is shown;

[0051] Figure 23 Still another example of a housing is shown. DETAILED DESCRIPTION

[0052] <1> First embodiment

[0053] (1) Structure of optical displacement meter

[0054] Hereinafter, an optical displacement meter using a light section method will be described as an optical displacement meter according to an embodiment of the present invention with reference to the drawings. Figure 1 FIG. 1 is a block diagram showing the structure of the optical displacement meter according to the first embodiment. Figure 1 As shown, the optical displacement meter 500 includes a camera 100, a processor 200, an input unit 300, and a display 400. The camera 100 may be separated from the processor 200. The camera 100 and the processor 200 may be integrated into one body.

[0055] The camera 100 includes a laser projector 110, an LED projector 120, and an imaging unit 130. The laser projector 110 is configured to emit a strip of measurement light extending in one direction toward the measurement object (hereinafter referred to as "workpiece W"). Instead of the strip of measurement light extending in one direction, the laser projector 110 may be configured to emit a point of light for scanning in one direction as measurement light toward the workpiece W. The LED projector 120 is configured to emit uniform observation light toward the workpiece W. The imaging unit 130 receives the measurement light or observation light reflected from the workpiece W and outputs a distribution of the amount of received light.

[0056] The processor 200 includes a memory 201 and a control unit 202. The memory 201 is composed of a device such as a random access memory (RAM), a read-only memory (ROM), a hard disk, or a semiconductor memory, and stores a measurement program. The control unit 202 is, for example, a central processing unit (CPU).

[0057] The processor 200 further includes a setup unit 210, a head control unit 220, a measurement image generation unit 230, an observation image generation unit 240, a contour generation unit 250, a measurement unit 260, and a display processing unit 270 as functional units. The control unit 202 executes a measurement program stored in the memory 201, thereby implementing the functional units of the processor 200. Some or all of the functional units of the processor 200 may be implemented using hardware such as electronic circuits.

[0058] The display processing unit 270 of the processor 200 switches the display of the observation image, the measurement image, and the composite image (each of which will be described later). The setting unit 210 sets any one of the observation image, the measurement image, and the composite image as the image to be displayed on the display 400 based on the designation provided by the input unit 300.

[0059] The setting unit 210 also sets imaging conditions such as the brightness or intensity of the measurement light, the brightness or intensity of the observation light, and the exposure time period of the imaging unit 130 based on the designation provided by the input unit 300. The user is allowed to designate the imaging conditions to the setting unit 210 by operating the input unit 300. The head control unit 220 controls the operations of the laser projector 110, the LED projector 120, and the imaging unit 130 based on the imaging conditions set to the setting unit 210.

[0060] The measurement image generation unit 230 generates measurement image data based on the received light amount distribution of the measurement light output by the imaging unit 130. This measurement image data shows an image of the workpiece W irradiated with the measurement light (hereinafter referred to as the "measurement image"). The observation image generation unit 240 generates observation image data based on the received light amount distribution of the light including the observation light output by the imaging unit 130. The observation image data shows an image of the workpiece W irradiated with the light including the measurement light (hereinafter referred to as the "observation image").

[0061] The "observation image" of the present invention refers to an image represented by image data generated by the imaging unit 130 capturing an image of the workpiece W when the LED projector 120 emits observation light onto the workpiece W, regardless of the lighting state of the laser projector 110. The "measurement image" of the present invention refers to an image represented by image data generated by the imaging unit 130 capturing an image of the workpiece W when the laser projector 110 emits measurement light onto the workpiece W but the LED projector 120 does not emit observation light onto the workpiece W. The "synthetic image" of the present invention refers to an image represented by image data generated to depict a contour superimposed on a measurement image or an observation image.

[0062] The outline generation unit 250 generates outline data showing the outline of the workpiece W based on the measurement image data generated by the measurement image generation unit 230. The measurement unit 260 performs measurement processing based on the outline data generated by the outline generation unit 250. The measurement processing is performed to calculate the size or displacement of a specified portion on the surface of the workpiece W based on the outline data. The user is allowed to specify a desired portion of the workpiece W to be subjected to the measurement processing in the outline data by operating the input unit 300.

[0063] The display processing unit 270 displays various images on the display 400. These images include a measurement image, an observation image, a profile, and an image showing the results of measurement performed by the measurement unit 260. A user is allowed to specify an image to be displayed to the display processing unit 270 and instruct the display processing unit 270 to switch the displayed image by operating the input unit 300. Details of the display processing unit 270 will be described later.

[0064] The input unit 300 includes a keyboard and a pointing device and can be operated by a user. A mouse, a joystick or other device is used as the pointing device. Alternatively, a dedicated console can be used as the input unit 300. The display 400 is composed of, for example, a liquid crystal display panel or an organic electroluminescent (EL) panel.

[0065] (2) Camera

[0066] Figure 2 It shows Figure 1 A stereoscopic view of the appearance of the camera 100 in FIG. Figure 3 It shows Figure 1 The bottom view of the camera 100 in FIG. Figure 2 and Figure 3 As shown, the housing 140 of the camera 100 has a substantially rectangular parallelepiped shape and an internal space. The laser projector 110, the LED projector 120, and the camera unit 130 are accommodated in the internal space of the housing 140. The housing 140 is defined with a width direction, a longitudinal direction, and an up-down direction that are perpendicular to each other.

[0067] The lower portion of housing 140 is provided with a lower surface 141 and an inclined surface 142. Furthermore, an upwardly recessed recess 143 is formed approximately in the center of the lower portion of housing 140 in the longitudinal direction. Lower surface 141 is approximately perpendicular to the vertical direction and faces downward. Inclined surface 142 is located within recess 143 and faces obliquely downward. Lower surface 141 is formed with a measurement window 144 and an observation window 145. Inclined surface 142 is formed with a light receiving window 146.

[0068] The measurement window 144 has a substantially rectangular shape extending in the width direction and is configured so as to allow downward transmission of light from the liquid crystal display device contained in the housing 140. Figure 1 The observation window 145 has a substantially square shape and is arranged in the substantially central portion in the width direction so as to allow downward transmission of the light from the laser projector 110 contained in the housing 140. Figure 1 The light receiving window 146 has a circular shape and is arranged in the approximate center portion in the width direction so that light from an obliquely downward direction can pass through and reach the LED projector 120 accommodated in the housing 140. Figure 1 The camera unit 130 is provided.

[0069] In this embodiment, observation window 145 is located between measurement window 144 and recess 143. That is, observation window 145 is closer to light receiving window 146 in the longitudinal direction than measurement window 144. This configuration prevents housing 140 from having a large size in the longitudinal direction.

[0070] Figure 4 and Figure 5 Is used to illustrate Figure 1FIG. 1 is a diagram showing the configuration of the laser projector 110, LED projector 120, and camera unit 130. Figure 4 The camera 100 is shown as viewed from the long side direction. Figure 5 FIG. 1 shows the camera 100 as viewed from the width direction. Figure 4 As shown, the laser projector 110 includes a laser diode (LD) 111 , a collimating lens 112 , and light projection lenses 113 and 114 .

[0071] The LD 111 , the collimator lens 112 , and the light projection lenses 113 and 114 are arranged in the housing 140 in this order from the upper side to the lower side. Figure 2 The measurement window 144 is arranged below the light projection lens 114. The LD 111, the collimating lens 112, and the light projection lenses 113 and 114 provide a light projection axis for the laser projector 110. The light projection axis of the laser projector 110 is substantially parallel to the up-down direction and substantially perpendicular to the lower surface 141 of the housing 140.

[0072] LD 111 emits downwardly a laser beam with a wavelength of, for example, 400 nm to 480 nm as measurement light. Collimating lens 112 collimates the measurement light emitted by LD 111 while transmitting it. Light projection lenses 113 and 114 spread the measurement light, collimated by collimating lens 112, into a stripe in the width direction while transmitting it. The measurement light, spread into a stripe by light projection lenses 113 and 114, passes through measurement window 144 and illuminates workpiece W.

[0073] The LED projector 120 is implemented by an LED and is arranged in the housing 140 so as to be close to Figure 2 The LED projector 120 has an observation window 145. The light projection axis of the LED projector 120 is approximately parallel to the vertical direction and approximately perpendicular to the lower surface 141 of the housing 140. In other words, the light projection axis of the LED projector 120 is approximately parallel to the light projection axis of the laser projector 110. The LED projector 120 emits light with a wavelength of 400 nm to 480 nm downward as observation light. The observation light emitted by the LED projector 120 passes through the observation window 145 and illuminates the workpiece W.

[0074] like Figure 5As shown, the imaging unit 130 includes a light receiver 131, a light receiving lens 132, and an optical filter 133. The light receiver 131 is, for example, a complementary metal oxide semiconductor (CMOS) sensor and has a light receiving surface composed of a plurality of light receiving elements arranged two-dimensionally. The light receiving elements are, for example, photodiodes. The light receiver 131 and the light receiving lens 132 are arranged in the housing 140 such that the plane containing the light receiving surface of the light receiver 131 and the plane containing the main surface of the light receiving lens 132 satisfy the Scheimpflug condition relative to the light projection axis of the laser projector 110.

[0075] The light receiving lens 132 is arranged close to Figure 2 The light receiving window 146 is formed so that the main surface is substantially parallel to the inclined surface 142 of the housing 140. These configuration conditions enable the housing 140 to accommodate the laser projector 110, the LED projector 120, and the camera unit 130 that satisfy the Scheimpflug condition in a compact space.

[0076] The light receiving lens 132 guides the measurement light or observation light reflected from the workpiece W and then passing through the light receiving window 146 to the light receiver 131 while converging the measurement light or observation light. The light receiver 131 receives the measurement light or observation light converged by the light receiving lens 132 via the optical filter 133, and then the light receiver 131 outputs a received light amount distribution.

[0077] The optical filter 133 is, for example, a bandpass filter, and is attached to the light receiving surface of the light receiver 131 . Figure 6 An example of the transmission wavelength band of the optical filter 133 is shown. Figure 6 , the horizontal axis represents the wavelength of light, and the vertical axis represents the normalized intensity of light. The wavelength distribution of the measurement light is represented by a solid line, the wavelength distribution of the observation light is represented by a dotted line, and the transmission wavelength band of the optical filter 133 is represented by a hatched pattern.

[0078] exist Figure 6 In the example shown, the wavelength of the measurement light is approximately 450 nm, and the central wavelength of the observation light is approximately equal to the wavelength of the measurement light. Optical filter 133 transmits light with a wavelength of approximately 450 nm and blocks light of other wavelength bands. In this case, the measurement light and the observation light component with a wavelength approximately equal to the measurement light's wavelength pass through optical filter 133 and reach light receiver 131. On the other hand, the observation light component with a wavelength significantly different from that of the measurement light, as well as ambient light, are blocked by optical filter 133.

[0079] Under these conditions, profile data and observed image data are accurately generated. Furthermore, measuring light with a wavelength of 400 nm or greater allows the user to easily visually identify the measuring light. This improves the usability of optical displacement meter 500. Furthermore, measuring light with a wavelength of 480 nm or less enables highly accurate profile data generation.

[0080] exist Figure 6 In the example of , although the central wavelength of the observation light is approximately equal to the wavelength of the measurement light, the embodiments of the present invention are not limited to this relationship. Under the condition that the wavelength of the measurement light is included in the wavelength distribution range of the observation light, the central wavelength of the observation light may not be equal to the wavelength of the measurement light. In addition, under the condition that the transmittance of the optical filter 133 within the wavelength range of the measurement light is higher than the transmittance of the optical filter 133 outside the wavelength range of the measurement light, the transmission wavelength band of the optical filter 133 may be narrower or wider than Figure 6 The scope of the examples in .

[0081] (3) Generation of contour data

[0082] Figure 7 It is a perspective view of the appearance of the camera 100 and the workpiece W. Figure 8 and Figure 9 The relationship between the irradiation position of the measurement light on the surface of the workpiece W and the incident position of the light at the light receiver 131 is shown respectively. Figures 7 to 9 In FIG, two directions perpendicular to each other on the horizontal plane are defined as the X1 direction and the Y1 direction, and are indicated by arrows X1 and Y1, respectively. In addition, the vertical direction is defined as the Z1 direction, and is indicated by arrow Z1. The X1 direction, the Y1 direction, and the Z1 direction correspond to Figure 2 The width direction, long side direction and up-down direction of the housing 140. Figure 8 and Figure 9 In FIG. 1 , two directions perpendicular to each other on the light receiving surface of the light receiver 131 are defined as an X2 direction and a Z2 direction, and are indicated by arrows X2 and Z2, respectively.

[0083] exist Figure 7 In the example shown in FIG1 , a groove having a trapezoidal cross section is formed in the surface of the workpiece W so as to extend in the Y1 direction. The camera 100 emits a strip of measurement light to the surface of the workpiece W along the X1 direction. Hereinafter, the linear area on the surface of the workpiece W to which the strip of measurement light is emitted is referred to as the "irradiation area T1". Figure 8 As shown, the measurement light reflected at the irradiation area T1 enters the light receiver 131 via the light receiving lens 132. In this case, the difference in the reflection position of the light at the irradiation area T1 in the Z1 direction causes the incident position of the reflected light to the light receiver 131 to change in the Z2 direction.

[0084] Likewise, Figure 9 As shown, the difference in the reflected position of the light in the irradiation area T1 in the X1 direction causes a change in the incident position of the reflected light on the light receiver 131 in the X2 direction. In view of this, the position of the light incident on the light receiver 131 in the Z2 direction represents the position or height of the irradiation area T1 in the Z1 direction, and the incident position of the light in the X2 direction on the light receiver 131 represents the position of the irradiation area T1 in the X1 direction.

[0085] Figure 10 : shows the distribution of the amount of received light at the light receiving surface of the light receiver 131. Figure 10 As shown, the plurality of pixels "p" of the light receiver 131 are arranged two-dimensionally along the X2 direction and the Z2 direction. Each array of the plurality of pixels "p" along the Z2 direction is referred to as a "pixel array SS". Figure 10 As shown, in Figure 7 Most of the light reflected at the irradiation area T1 enters the light receiving area R1. Therefore, the amount of light received by the pixel "p" at the light receiving area R1 is large. Figure 10 The received light quantity distribution of the measurement light in Figure 1 The measurement image generation unit 230 in generates measurement image data.

[0086] Based on the measured image data, Figure 1 The outline generation unit 250 generates waveform data for each pixel array SS. Figure 11 Show Figure 10 The waveform data of a pixel array SS in Figure 11 In FIG, the horizontal axis represents the position in the Z2 direction, and the vertical axis represents the amount of received light. Figure 11 As shown, the waveform data of a pixel array SS includes Figure 10 The position of the peak "P" in the Z2 direction (hereinafter referred to as "peak position PP") represents the height of the surface or reflection surface at the irradiation area T1 of the workpiece W.

[0087] The outline generation unit 250 detects one peak position PP for each waveform data of the corresponding pixel array SS. Furthermore, the outline generation unit 250 generates outline data showing the outline or shape of the irradiation area T1 of the workpiece W based on the plurality of peak positions PP.

[0088] Figure 12 Show Figure 10 All peak positions PP in the received light amount distribution. Figure 13 Shown based on Figure 12 The profile data generated by the peak position PP. Figure 12 and Figure 13As shown, all the detected peak positions PP are shown by continuous lines to generate profile data showing the profile of the workpiece W.

[0089] (4) Setting of image acquisition conditions

[0090] As described above, the optical displacement meter 500 allows switching of the display between the observation image, the measurement image, and the synthesized image, and also allows specification of image generation conditions. Figure 1 LED projector 120 is controlled to illuminate simultaneously with laser projector 110. In other words, observation light and measurement light are emitted simultaneously. When laser projector 110 and imaging unit 130 satisfy the Scheimpflug condition, the focal point of light receiver 131 coincides with every position on workpiece W measured by measurement light, even if the height of one portion of workpiece W differs significantly from another. This generates observation image data showing the portion of workpiece W illuminated by measurement light and its surrounding area.

[0091] An observation image is displayed on the display 400 based on the generated observation image data. Figure 14 and Figure 15 4 shows an example of a screen displayed on the display 400. Figure 14 As shown, the screen on the display 400 includes an image display area 410 and a designated receiving area 420 arranged side by side. Various images can be displayed in the image display area 410. Figure 14 and Figure 15 In the example of , the observed image is displayed in the image display area 410 .

[0092] A graphical user interface (GUI) including operation buttons and an operation bar or a numerical value input field is displayed in the designated receiving area 420. Figure 1 The input unit 300 operates the GUI in the designation receiving area 420 to designate imaging conditions. Figure 1 The setting unit 210 sets the imaging conditions according to the designation provided via the designation receiving area 420 .

[0093] like Figure 14 As shown in FIG. 1 , the portion of the workpiece W irradiated with the measurement light clearly appears in the observed image as a bright line. Figure 14 In the example of , since the brightness of the observation light is low, the area near the measurement light irradiated portion on the workpiece W does not appear clearly. In this case, the user can increase the brightness of the observation light by operating the GUI in the designated receiving area 420. Figure 15 As shown, this enables displaying, in the image display area 410 , an observation image that clearly shows the measurement light irradiated portion and its vicinity on the workpiece W but does not clearly show other areas.

[0094] The user is allowed to adjust the positions of the camera 100 and the workpiece W while viewing the observation image displayed in the image display area 410 so that the desired portion of the workpiece W will clearly appear in the observation image. Therefore, the position of the camera 100 relative to the workpiece W can be easily adjusted. Furthermore, the user is allowed to more accurately adjust the position of the camera 100 relative to the workpiece W by adjusting the position of the camera 100 or the workpiece W so that the bright line will overlap with the desired portion of the workpiece W in the observation image.

[0095] While it is important that the observation image clearly shows the portion of the workpiece W illuminated by the measurement light, the required clarity of the display area near the illuminated portion varies depending on the observation situation. For this reason, if the LED projector 120 automatically illuminates and automatically adjusts the brightness of the observation light, the usability of the optical displacement meter 500 would be undesirably reduced. Therefore, in this embodiment, the LED projector 120 illuminates in response to user instructions, rather than automatically. Furthermore, the brightness of the observation light is not adjusted automatically, but rather in response to manual user input.

[0096] Other images that facilitate position adjustment of the camera 100 relative to the workpiece W can be displayed in the image display area 410 . Figure 16 Another display example of the image display area 410 is shown. Figure 1 The display processing unit 270 generates first synthesized image data showing a first synthesized image including the contour superimposed on the measurement image by synthesizing the measurement image data and the contour data. Figure 16 The image display area 410 displays a first synthesized image based on the first synthesized image data.

[0097] When the measurement light is reflected multiple times at the surface of the workpiece W or enters the inside of the workpiece W, light reflected from a position other than the surface of the workpiece W reaches the imaging unit 130. This provides an outline that does not reflect the actual cross-sectional shape of the workpiece W. In this case, Figure 16 As shown, the bright line and the contour of the measuring light are displayed in a superimposed manner so that the user can grasp the portion causing the incorrect contour.

[0098] In response to Figure 1 The display processing unit 270 switches the instruction of the input unit 300 to Figure 15 The observed image and Figure 16The image is displayed in image display area 410 using the first synthesized image. For example, as in the case of an integrated circuit chip, workpiece W may include a plurality of parts having similar configurations and formed so as to be arranged along the Y1 direction, or the longitudinal direction of housing 140. Furthermore, in this case, the user can easily recognize whether the desired portion of workpiece W is being irradiated with measurement light by viewing the outline in the first synthesized image and the portion of workpiece W irradiated with measurement light in the observation image.

[0099] Figure 17 4 shows another display example of the image display area 410. The display processing unit 270 generates second synthesized image data showing a second synthesized image including a contour superimposed on the observed image by synthesizing the observed image data and the contour data. Figure 17 In the example of , the second synthetic image is displayed in the image display area 410. The user easily recognizes whether the measurement light irradiates the desired portion on the workpiece W by viewing the observation image and the outline in the second synthetic image.

[0100] (5) Effect

[0101] In the optical displacement meter 500 of this embodiment, the laser projector 110 emits measurement light toward the workpiece W, and the measurement light reflected from the workpiece W is focused by the light receiving lens 132. The light receiver 131 receives the measurement light focused by the light receiving lens 132 and then outputs a received light quantity distribution. Profile data is generated based on the received light quantity distribution of the measurement light output by the light receiver 131.

[0102] On the other hand, the LED projector 120 emits observation light toward the workpiece W, and the observation light reflected from the workpiece W is condensed by the light receiving lens 132. The light receiver 131 receives the observation light condensed by the light receiving lens 132 and outputs a received light quantity distribution. Observation image data is generated based on the received light quantity distribution of the observation light output by the light receiver 131.

[0103] Under these conditions, the laser projector 110, the light receiver 131, and the light receiving lens 132 are arranged so that the plane containing the light receiving surface of the light receiver 131 and the plane containing the main surface of the light receiving lens 132 satisfy the Scheimpflug condition relative to the light projection axis of the laser projector 110. In this case, even when the height of one portion of the workpiece W greatly differs from the height of other portions, the focal point of the light receiver 131 coincides with every position measured by the measurement light on the workpiece W. As a result, profile data is generated with high accuracy.

[0104] Furthermore, observation image data is generated that shows an observation image in which the focal point of the light receiver 131 coincides with the position measured by the measurement light on the workpiece W. Thus, the observation image clearly shows the measurement position measured by the measurement light on the workpiece W. The observation image data shows a natural observation image of the workpiece W as viewed by a user from above.

[0105] This facilitates the user to adjust the position of the camera 100 relative to the workpiece W by adjusting the position of the camera 100 or the workpiece W so that the desired portion of the workpiece W will clearly appear in the observation image. As a result, the position adjustment of the optical displacement meter 500 relative to the workpiece W is easily performed without reducing the measurement accuracy of the contour.

[0106] <2> Second embodiment

[0107] The optical displacement meter 500 according to the second embodiment is different from the optical displacement meter 500 according to the first embodiment in the following manner. Figure 1 The optical displacement meter 500 in FIG. In this embodiment, the laser projector 110 and the LED projector 120 are controlled by the head control unit 220 to illuminate alternately. Measurement image data and observation image data are alternately generated by the measurement image generation unit 230 and the observation image generation unit 240, respectively.

[0108] Figure 18 A measurement image based on the measurement image data generated by the measurement image generation unit 230 is shown. Figure 19 2 shows an observed image based on the observed image data generated by the observed image generation unit 240. Figure 18 As shown in FIG, the portion of the workpiece W irradiated with the measurement light appears as a bright line in the measurement image. Figure 19 As shown, in the observation image of this embodiment, the bright line indicating the portion on the workpiece W irradiated with the measurement light does not appear.

[0109] The display processing unit 270 will Figure 18 The measurement image and Figure 19 The observation images are repeatedly and alternately displayed on the display 400. While viewing the alternating display of the measurement image and the observation image, the user is allowed to adjust the position of the camera 100 or the workpiece W so that the bright line in the measurement image overlaps with the desired portion of the workpiece W in the observation image. Thus, the position of the camera 100 relative to the workpiece W is easily and accurately adjusted.

[0110] The display processing unit 270 can, for example, switch between the measurement image and the observation image at a frequency of 10 times or more per second. In this case, the user can hardly perceive the alternation between the measurement image and the observation image. Alternatively, the user perceives that the same image as the image obtained when the laser projector 110 and the LED projector 120 are simultaneously lit is displayed on the display 400, that is, Figure 15 The user can more efficiently adjust the position of the camera 100 relative to the workpiece W by perceiving such an image.

[0111] In another case, the display processing unit 270 can generate image data showing the same image as that obtained when the laser projector 110 and the LED projector 120 are simultaneously lit by synthesizing the measurement image data and the observation image data, and can display the thus obtained image on the display 400. In this case, the user can more efficiently adjust the position of the camera 100 relative to the workpiece W by viewing the image displayed on the display 400.

[0112] <3> Third embodiment

[0113] The optical displacement meter 500 according to the third embodiment is different from the optical displacement meter 500 according to the first embodiment in the following manner. Figure 1 The optical displacement meter 500 in FIG. 1 has the same structure. In this embodiment, the laser projector 110 and the LED projector 120 are controlled by the head control unit 220 to light alternately during the exposure period of the imaging unit 130. The observation image generation unit 240 generates observation image data.

[0114] Specifically, the head control unit 220 generates binary control pulses for controlling the laser projector 110, LED projector 120, and imaging unit 130 of the camera 100. The control pulses for controlling the imaging unit 130 are referred to as "imaging pulses." The control pulses for controlling the laser projector 110 are referred to as "measurement pulses." The control pulses for controlling the LED projector 120 are referred to as "observation pulses."

[0115] The imaging unit 130 changes to an exposure state in response to an imaging pulse at an "H" level, and changes to a non-exposure state in response to an imaging pulse at an "L" level. The laser projector 110 changes to a lighting state in response to a measuring pulse at an "H" level, and changes to an extinguishing state in response to a measuring pulse at an "L" level. The LED projector 120 changes to a lighting state in response to an observation pulse at an "H" level, and changes to an extinguishing state in response to an observation pulse at an "L" level.

[0116] Figure 20 is a timing diagram of the control pulses to be applied to the camera 100. Figure 20 As shown, the measuring pulse P1, the observing pulse P2, and the imaging pulse P3 are each at an "L" level at the initial time point t0. Thus, the laser projector 110 is off, the LED projector 120 is off, and the imaging unit 130 is in a non-exposure state.

[0117] At time t1, the imaging pulse P3 rises to an "H" level, and the measuring pulse P1 rises to an "H" level. At this point, the imaging unit 130 enters the exposure state. The laser projector 110 enters the illuminated state and emits measurement light toward the workpiece W. At time t2, the measuring pulse P1 falls to an "L" level, and the observation pulse P2 rises to an "H" level. At this point, the laser projector 110 enters the extinguished state. The LED projector 120 enters the illuminated state and emits observation light toward the workpiece W.

[0118] At time t3, imaging pulse P3 drops to an "L" level, and observation pulse P2 also drops to an "L" level. At this point, imaging unit 130 enters a non-exposure state. LED projector 120 is turned off. These conditions are maintained until time t4. The operations from time t1 to time t4 are then repeated.

[0119] The period between time points t1 and t3 is an exposure period. The imaging unit 130 receives light reflected from the workpiece W during the exposure period, and outputs a received light quantity distribution of the reflected light during the period between time points t3 and t4. Based on the received light quantity distribution output by the imaging unit 130, the observation image generation unit 240 generates observation image data. The display processing unit 270 displays an observation image on the display 400 based on the observation image data generated by the observation image generation unit 240.

[0120] The observation image data of this embodiment shows the same observation image as the image obtained when the laser projector 110 and the LED projector 120 are simultaneously lit, that is, Figure 15 4. This allows the user to adjust the position of the camera 100 or the workpiece W so that the bright line will overlap with the desired portion of the workpiece W in the observation image while viewing the observation image displayed on the display 400. Thus, the position of the camera 100 relative to the workpiece W is easily and accurately adjusted.

[0121] In this embodiment, the laser projector 110 and the LED projector 120 are controlled not to light up at the same time. However, due to a malfunction of the head control unit 220 or other reasons, the laser projector 110 and the LED projector 120 may light up at the same time.

[0122] In some cases, it may be desirable to limit the intensity of light emitted from camera 100 so as not to exceed a predetermined upper limit. In such cases, the intensity of the measurement light must be reduced below the upper limit to prevent the combined intensities of the measurement and observation light from exceeding the upper limit. Consequently, the exposure time of imaging unit 130 must be increased, resulting in reduced processing efficiency.

[0123] On the other hand, by prohibiting the simultaneous lighting of the laser projector 110 and the LED projector 120, the intensity of the measurement light can be maintained at the upper limit. This eliminates the need to extend the exposure time of the imaging unit 130, thereby preventing a decrease in processing efficiency. In view of this, an exclusive control circuit can be further provided to prohibit the simultaneous lighting of the laser projector 110 and the LED projector 120.

[0124] Figure 21 An example of an exclusive control circuit is shown. Figure 21 As shown, the exclusive control circuit 10 includes amplifier circuits 1 and 2, NOT circuits 3 and 4, an AND circuit 5, and an npn-type bipolar transistor 6 (hereinafter referred to as "transistor 6"). The input of amplifier circuit 1 and the input of NOT circuit 3 are coupled to terminal 221 for outputting a measurement pulse P1 of the head control unit 220. One of the inputs of AND circuit 5 is coupled to terminal 222 for outputting an observation pulse P2 of the head control unit 220. The output of NOT circuit 3 and the other input of AND circuit 5 are coupled to each other. The output of AND circuit 5 and the input of amplifier circuit 2 are coupled to each other.

[0125] The anode of LD 111 of laser projector 110 is coupled to the output of amplifier circuit 1. The cathode of LD 111 is coupled to the collector of transistor 6. The emitter of transistor 6 is grounded. The anode of the LED of LED projector 120 and the input of NOT circuit 4 are coupled to the output of amplifier circuit 2. The cathode of the LED is grounded. The output of NOT circuit 4 is coupled to the base of transistor 6.

[0126] When the measurement pulse P1 is at an "H" level and the observation pulse P2 is at an "H" level or an "L" level, the exclusive control circuit 10 applies an "L" level control pulse to the LED projector 120. Thus, when both the measurement pulse P1 and the observation pulse P2 are at an "H" level, the LED projector 120 is not illuminated. This prevents the laser projector 110 and the LED projector 120 from being illuminated simultaneously. This exclusive control circuit can also be incorporated into the optical displacement meter 500 of the second embodiment.

[0127] <4> Other embodiments

[0128] (1) In the above-described embodiment, although the housing 140 is formed with the recessed portion 143 , embodiments of the present invention are not limited to this configuration. Figure 22 Another example of the housing 140 is shown. Figure 22 As shown, the light receiving lens 132 may be located lower than the lower surface 141 of the housing 140 according to the measurement distance between the camera 100 and the workpiece W. In this case, the housing 140 may not be formed with the recess 143 .

[0129] (2) In the above-described embodiment, although the LED projector 120 is located closer to the imaging unit 130 in the long-side direction than the laser projector 110 , embodiments of the present invention are not limited to this configuration. Figure 23 140 is shown as another example. Figure 23 As shown, by allowing the housing 140 to be slightly larger in the longitudinal direction, the LED projector 120 can be located farther from the imaging unit 130 in the longitudinal direction than the laser projector 110. In response to this, the observation window 145 is located farther from the light receiving window 146 in the longitudinal direction than the measurement window 144.

[0130] (3) In the above embodiment, although the measurement window 144 and the observation window 145 are separately provided on the lower surface 141 of the housing 140, the embodiment of the present invention is not limited to this configuration. Instead of the measurement window 144 and the observation window 145, a window to be used for both transmitting the measurement light and transmitting the observation light may be provided on the lower surface 141 of the housing 140.

[0131] (4) In the above embodiment, although the bright line of the measurement light is displayed in a superimposed manner on the observation image, the embodiment of the present invention is not limited to this display method. The bright line of the measurement light may not be displayed in a superimposed manner on the observation image. In this case, the user can easily adjust the position of the camera 100 relative to the workpiece W by adjusting the position of the camera 100 or the workpiece W so that the desired portion of the workpiece W will clearly appear in the observation image while viewing the observation image.

[0132] (5) In the above embodiment, although the wavelength of the measuring light is 400 nm or more and 480 nm or less, embodiments of the present invention are not limited to this wavelength range. In cases where visual confirmation of the portion irradiated with the measuring light is not necessary, the wavelength of the measuring light may be shorter than 400 nm. In other cases, the wavelength of the measuring light may be longer than 480 nm, provided that the measuring light does not significantly reduce the accuracy of profile measurement.

[0133] The wavelength of the observation light and the transmission wavelength band of the optical filter 133 may be changed according to the wavelength of the measurement light. In the case where ambient light is rarely incident on the light receiver 131 , the optical filter 133 may not be attached to the light receiving surface of the light receiver 131 .

[0134] <5> Correspondence between the constituent elements of the claims and the components of the embodiments

[0135] The above-described embodiment includes components that are examples of constituent elements of the claims. That is, the workpiece W corresponds to the measurement object, the optical displacement meter 500 corresponds to the optical displacement meter, the laser projector 110 corresponds to the laser projector, and the LED projector 120 corresponds to the LED projector. The light receiving lens 132 corresponds to the light receiving lens, the light receiver 131 corresponds to the light receiver, the processor 200 corresponds to the processor, the exclusive control circuit 10 corresponds to the exclusive control circuit, and the housing 140 corresponds to the housing. The lower surface 141 and the inclined surface 142 correspond to the first surface and the second surface, respectively, and the recess 143 corresponds to the recess. The measurement window 144 corresponds to the measurement window, the observation window 145 corresponds to the observation window, the light receiving window 146 corresponds to the light receiving window, and the optical filter 133 corresponds to the bandpass filter.

Claims

1. An optical displacement meter using a light section method, for measuring the contour of a measurement object, the optical displacement meter comprising: a laser projector having a first light projection axis and configured to emit a stripe-shaped laser light extending in one direction or a point-shaped laser light for scanning in the one direction as measurement light to the measurement object; an LED projector configured to emit uniform light as observation light to the measurement object; a light receiving lens configured to converge reflected light of the measurement light and reflected light of the observation light reflected back from the measurement object; a light receiver having a light receiving surface composed of a plurality of light receiving elements arranged two-dimensionally and configured to receive the light concentrated by the light receiving lens and output a received light amount distribution; as well as a processor configured to, during measurement, execute processing for generating outline data based on a received-light amount distribution of the measurement light output by the light receiver, and to execute processing for generating observation image data based on a received-light amount distribution of the observation light output by the light receiver, the outline data showing an outline of the measurement object, the observation image data showing an image of the measurement object irradiated with the observation light as an observation image, wherein the laser projector, the light receiver, and the light receiving lens are arranged so that a plane containing the light receiving surface and a plane containing the main surface of the light receiving lens satisfy a Scheimpflug condition with respect to the first light projection axis, thereby generating observation image data showing an observation image in which the focus of the light receiver is relatively consistent with an area near a measurement position irradiated by the measurement light during measurement, The processor is configured to generate, based on a received light amount distribution of the measurement light output by the light receiver, composite image data of a first composite image showing a contour and a bright line of the measurement light in a superimposed manner by synthesizing measurement image data and the contour data, wherein the measurement image data shows an image of the measurement object irradiated by the measurement light as a measurement image, and the processor is further configured to display the first composite image and the observation image.

2. The optical displacement meter according to claim 1, wherein: The processor is configured to control the laser projector and the LED projector so that the measuring light and the observation light are emitted simultaneously, and the processor is also configured to generate observation image data showing an observation image in which a bright line of the measuring light is shown superimposed on a measurement position on the measurement object where the measuring light is irradiated.

3. The optical displacement meter according to claim 1, wherein: The processor is configured to control the laser projector and the LED projector so that the measuring light and the observation light are emitted alternately, and the processor is also configured to alternately perform processing for generating measurement image data based on the received light amount distribution of the measuring light output by the light receiver and processing for generating the observation image data, and the measurement image data shows an image of the measurement object irradiated by the measuring light as a measurement image.

4. The optical displacement meter according to claim 3, wherein: The processor is configured to display an image by automatically switching between the measurement image and the observation image.

5. The optical displacement meter according to claim 3, wherein: The processor is configured to synthesize the measurement image data and the observation image data, and display an observation image showing a bright line of the measurement light superimposed on a measurement position on the measurement object irradiated with the measurement light.

6. The optical displacement meter according to claim 1, wherein: The processor is configured to control the laser projector and the LED projector so that the measuring light and the observation light are alternately emitted during an exposure time period of the light receiver, and the processor is further configured to generate observation image data showing an observation image in which a bright line of the measuring light is shown superimposed on a measurement position on the measurement object where the measuring light is irradiated. 7 . The optical displacement meter according to claim 3 , further comprising an exclusive control circuit configured to prohibit simultaneous emission of the measurement light and the observation light.

8. The optical displacement meter according to claim 1, wherein: In a housing having an internal space for accommodating the laser projector, the LED projector, the light receiving lens, and the light receiver, the LED projector has a second light projection axis parallel to the first light projection axis of the laser projector, The housing comprises: a first surface perpendicular to the first light projection axis and the second light projection axis; a second surface disposed in a recessed portion recessed from the first surface toward the interior space in a manner inclined relative to the first surface; a measurement window provided to the first face and configured to transmit measurement light emitted from the laser projector to the measurement object; an observation window provided to the first face and configured to transmit observation light emitted from the LED projector to the measurement object; and a light receiving window provided to the second surface and configured to transmit reflected light of the measurement light and reflected light of the observation light reflected back from the measurement object.

9. The optical displacement meter according to claim 8, wherein: The observation window is provided at a position closer to the light receiving window than the measurement window.

10. The optical displacement meter according to claim 1, further comprising a bandpass filter provided on an optical path of light reflected from the measurement object. in, The laser projector is configured to emit measurement light having a wavelength of 400 nm or more and 480 nm or less, The LED projector is configured to emit observation light having a wavelength within a range including a wavelength of the measurement light, and The transmittance of the bandpass filter within the wavelength range of the measurement light is higher than the transmittance of the bandpass filter outside the wavelength range of the measurement light.

11. An optical displacement meter using a light section method, for measuring the contour of a measurement object, the optical displacement meter comprising: a laser projector having a first light projection axis and configured to emit a stripe-shaped laser light extending in one direction or a point-shaped laser light for scanning in the one direction as measurement light to the measurement object; an LED projector configured to emit uniform light as observation light to the measurement object; a light receiving lens configured to converge reflected light of the measurement light and reflected light of the observation light reflected back from the measurement object; a light receiver having a light receiving surface composed of a plurality of light receiving elements arranged two-dimensionally and configured to receive the light concentrated by the light receiving lens and output a received light amount distribution; as well as a processor configured to, during measurement, execute processing for generating outline data based on a received-light amount distribution of the measurement light output by the light receiver, and to execute processing for generating observation image data based on a received-light amount distribution of the observation light output by the light receiver, the outline data showing an outline of the measurement object, the observation image data showing an image of the measurement object irradiated with the observation light as an observation image, wherein the laser projector, the light receiver, and the light receiving lens are arranged so that a plane containing the light receiving surface and a plane containing the main surface of the light receiving lens satisfy a Scheimpflug condition with respect to the first light projection axis, thereby generating observation image data showing an observation image in which the focus of the light receiver is relatively consistent with an area near a measurement position irradiated by the measurement light during measurement, The processor is configured to display a second composite image including the contour superimposed on the observed image by composite the contour data and the observed image data.

Images