Optical displacement meter

Abstract

To provide an optical displacement meter with which it is possible to facilitate adjusting a workpiece position without lowering the accuracy of profile measurement.SOLUTION: An imaging head 100 includes: a laser projection unit 110 for projecting measurement light to a workpiece W; an LED projection unit 120 for projecting uniform observation light to the workpiece W; a light-receiving lens 132 for condensing the reflected light of measurement light and observation light from the workpiece W; a light-receiving unit 131 composed of a plurality of two-dimensionally arranged light-receiving elements; and a processing device 200. The laser projection unit 110, the light-receiving unit 131 and the light-receiving lens 132 are arranged so that a plane that includes a flat face including a light-receiving face and the principal face of the light-receiving lens 132 satisfies the Scheimpflug condition with regard to the projection light axis of the laser projection unit 110, whereby observation image data that indicates an observation image, with the focus of the light-receiving unit 131 matched relative thereto, in an area near a measurement position irradiated with measurement light at measurement time.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] In order to measure the profile of a measurement object (hereinafter referred to as a workpiece), an optical displacement meter of a light section method may be used. For example, in the optical displacement meter described in Patent Document 1, linear measurement light is irradiated onto the workpiece from a laser diode, and the reflected light is received by a two-dimensional CCD (charge coupled device). Based on the video signal generated by the CCD, the displacement in the height direction of the workpiece is measured.

[0003] In order for the user to accurately measure a desired position of the workpiece, the irradiation position of the measurement light must be accurately matched with the position on the workpiece to be measured by adjusting the relative position between the optical displacement meter and the workpiece. However, when the optical displacement meter and the workpiece are close to each other, it is difficult to observe the irradiation position of the measurement light with the naked eye.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the optical displacement meter described in Patent Document 1, a CCD is physically or optically directly opposed to the work in order to acquire a frontal image of the work. In this configuration, an overall clear image of the work can be acquired, and the position adjustment of the optical displacement meter becomes easy. However, when there are portions with greatly different heights on the measurement position of the work, perspective images in which the focus of the CCD coincides with each portion of the measurement position cannot be acquired. In this case, since the measurement accuracy of displacement varies according to the height of the measurement position, the profile of the work cannot be measured with high accuracy.

[0006] An object of the present invention is to provide an optical displacement meter capable of easily performing position adjustment with respect to a work without reducing the measurement accuracy of the profile.

Means for Solving the Problems

[0007] The optical displacement meter according to the first invention is an optical displacement meter of a light section method for measuring the profile of a measurement object, having a first light projection axis, a strip-shaped laser beam extending in a first direction, or a dot-shaped laser beam scanned in the first direction as measurement light for irradiating the measurement object, a LED light projection unit for irradiating the measurement object with uniform light as observation light, a light receiving lens for focusing the reflected light of the measurement light and the observation light from the measurement object, a light receiving unit having a light receiving surface composed of a plurality of two-dimensionally arranged light receiving elements, receiving the light focused by the light receiving lens, and outputting a light reception amount distribution, a process for generating profile data indicating the profile of the measurement object based on the light reception amount distribution of the measurement light output by the light receiving unit during measurement, and a process for generating observation image data indicating an observation image of the measurement object irradiated with the observation light as an observation image based on the light reception amount distribution of the observation light output by the light receiving unit, and a processing device for executing the processes, and the laser light projection unit, the light receiving unit, and the light receiving lens are arranged such that the plane including the light receiving surface and the plane including the main surface of the light receiving lens satisfy the Schimpflug condition with respect to the first light projection axis, so that observation image data showing an observation image in which the focus of the light receiving unit relatively coincides is generated in a region near the measurement position irradiated with the measurement light during measurement, and the LED light projection unit is more than the region near the measurement position, the direction of the first light projection axis and First direction the plane formed by By irradiating an observation light onto a wide area in a second direction orthogonal to the the generated observation image, in the degree of focus matching of the light receiving part decreases as it moves away from the area near the measurement position in the second direction. is This is the feature.

[0008] In this optical displacement meter, a strip-shaped laser beam extending in one direction or a dot-shaped laser beam scanned in one direction is irradiated onto the measurement object by the laser projection unit as the measurement light. The measurement light reflected from the measurement object is focused by the light receiving lens. The measurement light focused by the light receiving lens is received by a light receiving surface constituted by a plurality of light receiving elements two-dimensionally arranged in the light receiving part, and a light reception amount distribution is output. Based on the light reception amount distribution of the measurement light output by the light receiving part during measurement, profile data indicating the profile of the measurement object is generated.

[0009] Also, uniform light is irradiated onto the measurement object by the LED projection unit as the observation light. The observation light reflected from the measurement object is focused by the light receiving lens. The observation light focused by the light receiving lens is received by the light receiving surface of the light receiving part, and a light reception amount distribution is output. Based on the light reception amount distribution of the observation light output by the light receiving part, observation image data indicating an image of the measurement object irradiated with the observation light as an observation image is generated.

[0010] Here, the laser projection unit, the light receiving part, and the light receiving lens are arranged so that the plane including the light receiving surface of the light receiving part and the plane including the principal surface of the light receiving lens satisfy the Schimpflug condition with respect to the first projection axis of the laser projection unit. In this case, even when there are portions with greatly different heights on the measurement object, the focus of the light receiving part relatively matches in the area near the measurement position where the measurement light is irradiated during measurement. Therefore, the profile data is generated with high accuracy.

[0011] In addition, observation image data showing an observation image in which the focus of the light receiving unit is relatively aligned is generated in a region near the measurement position where the measurement light is irradiated during measurement. As a result, the measurement position by the measurement light on the measurement object appears clearly in the observation image. Therefore, the user can easily adjust the position of the optical displacement meter with respect to the measurement object by adjusting the position of the optical displacement meter or the measurement object so that a desired portion of the measurement object in the observation image becomes clear. As a result, it is possible to easily adjust the position of the optical displacement meter with respect to the measurement object without degrading the measurement accuracy of the profile.

[0012] The processing device may control the laser light projecting unit and the LED light projecting unit so that the measurement light and the observation light are emitted simultaneously, and generate observation image data in which a bright line of the measurement light is superimposed and displayed at the measurement position where the measurement light is irradiated on the measurement object.

[0013] In this case, the measurement position where the measurement light is irradiated on the measurement object appears clearly as a bright line in the observation image. The user can more easily and precisely adjust the position of the optical displacement meter with respect to the measurement object by adjusting the position of the optical displacement meter or the measurement object so that the bright line overlaps a desired portion of the measurement object in the observation image.

[0014] The processing device may control the laser light projecting unit and the LED light projecting unit so that the measurement light and the observation light are emitted alternately, and alternately execute a process of generating measurement image data showing an image of the measurement object irradiated with the measurement light as a measurement image based on the light reception amount distribution of the measurement light output by the light receiving unit and a process of generating the observation image data.

[0015] In this case, a bright line of the measurement light appears in the measurement image. The user can adjust the position of the optical displacement meter or the measurement object while visually recognizing the bright line of the measurement light in the measurement image and the measurement object in the observation image. As a result, the position of the optical displacement meter with respect to the measurement object can be precisely adjusted.

[0016] The processing device may automatically switch between and display the measurement image and the observation image. In this case, while visually recognizing the measurement image and the observation image that are automatically switched and displayed, the user can adjust the position of the optical displacement meter or the measurement object so that the bright line in the measurement image overlaps the desired part of the measurement object in the observation image. Thereby, the position adjustment of the optical displacement meter with respect to the measurement object can be performed more easily and precisely.

[0017] The processing device may synthesize the measurement image data with the observation image data and display an observation image in which the bright line of the measurement light is superimposed on the measurement position where the measurement object is irradiated with the measurement light. In this case, the user can adjust the position of the optical displacement meter or the measurement object so that the bright line in the observation image overlaps the desired part of the measurement object. Thereby, the position adjustment of the optical displacement meter with respect to the measurement object can be performed more easily and precisely.

[0018] The processing device may control the laser light projection unit and the LED light projection unit so that the measurement light and the observation light are alternately emitted within the same exposure period of the light receiving unit, and generate observation image data showing an observation image in which the bright line of the measurement light is superimposed on the measurement position where the measurement object is irradiated with the measurement light.

[0019] In this case, in the observation image, the measurement position where the measurement object is irradiated with the measurement light appears clearly as a bright line. By adjusting the position of the optical displacement meter or the measurement object so that the bright line overlaps the desired part of the measurement object in the observation image, the position adjustment of the optical displacement meter with respect to the measurement object can be performed more easily and precisely.

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

[0021] It may be desirable to limit the intensity of the light emitted from the optical displacement meter so that it does not exceed a predetermined upper limit value. According to the above configuration, since the exclusive control circuit prohibits the measurement light and the observation light from being emitted simultaneously, even when the intensity of the measurement light is at the upper limit value, the intensity of the light emitted from the optical displacement meter does not exceed the upper limit value. Therefore, it is possible to maintain the intensity of the measurement light at the upper limit value. As a result, it is possible to prevent a decrease in processing efficiency due to insufficient intensity of the measurement light.

[0022] Inside the housing having an internal space that houses the laser light projecting unit, the LED light projecting unit, the light receiving lens, and the light receiving unit, the LED light projecting unit has a second light projection axis substantially parallel to the first light projection axis of the laser light projecting unit, and the housing has a first surface substantially perpendicular to the first and second light projection axes, a second surface inclined with respect to the first surface, a measurement window provided on the first surface through which the measurement light irradiated from the laser light projecting unit to the measurement object passes, an observation window provided on the first surface through which the observation light irradiated from the LED light projecting unit to the measurement object passes, and a light receiving window provided on the second surface through which the reflected light of the measurement light and the observation light from the measurement object passes. In this case, it is possible to compactly house the laser light projecting unit, the LED light projecting unit, and the imaging unit while satisfying the conditions of shine proof.

[0023] The observation window may be provided at a position closer to the light receiving window than the measurement window. In this case, it is possible to prevent the housing from becoming larger in the direction in which the observation window, the measurement window, and the light receiving window are arranged.

[0024] The optical displacement meter further includes a band-pass filter provided on the optical path of the reflected light from the measurement object, the laser light projecting unit emits measurement light having a wavelength of 400 nm or more and 480 nm or less, the LED light projecting unit emits observation light having a wavelength range including the wavelength of the measurement light, and the transmittance of the band-pass filter within the wavelength range of the measurement light may be higher than the transmittance of the band-pass filter outside the wavelength range of the measurement light.

[0025] In this case, the band-pass filter transmits the component of the measurement light or the observation light having a wavelength substantially equal to that of the measurement light, and shields the components of the observation light having other wavelengths and the disturbance light. Therefore, the profile data and the observation image data can be accurately generated. Further, since the measurement light has a wavelength of 400 nm or more, the user can easily recognize the measurement light with the naked eye. This improves the usability of the optical displacement meter. Furthermore, since the measurement light has a wavelength of 480 nm or less, the profile data can be generated with high accuracy.

[0026] The processing device synthesizes measurement image data that shows an image of the measurement object irradiated with the measurement light as a measurement image and profile data based on the light reception amount distribution of the measurement light output by the light reception unit, thereby generating a profile and bright line of the measurement light and synthetic image data showing a first synthetic image in which are superimposed and displayed, and the first synthetic image and the observation image may be displayed.

[0027] The optical displacement meter according to the second invention is an optical displacement meter of the optical sectioning method for measuring the profile of a measurement object, has a first light projection axis, and irradiates the measurement object with a strip-shaped laser beam extending in one direction or a dot-shaped laser beam scanned in one direction as measurement light. A laser light projection unit, an LED light projection unit for irradiating the measurement object with uniform light as observation light, a light receiving lens for focusing the reflected light of the measurement light and the observation light from the measurement object, and a light receiving surface composed of a plurality of two-dimensionally arranged light receiving elements, and a light receiving unit that receives the light focused by the light receiving lens and outputs a light reception amount distribution, a process for generating profile data indicating the profile of the measurement object based on the light reception amount distribution of the measurement light output by the light receiving unit during measurement, and a process for generating observation image data indicating an image of the measurement object irradiated with the observation light as an observation image based on the light reception amount distribution of the observation light output by the light receiving unit. A processing device for executing the processes, and the laser light projection unit, the light receiving unit, and the light receiving lens are arranged such that the plane including the light receiving surface and the plane including the main surface of the light receiving lens satisfy the Scheimpflug condition with respect to the first light projection axis, so that observation image data indicating an observation image in which the focus of the light receiving unit is relatively aligned is generated in the region near the measurement position irradiated with the measurement light during measurement, and the processing device synthesizes measurement image data indicating an image of the measurement object irradiated with the measurement light as a measurement image and the profile data based on the light reception amount distribution of the measurement light output by the light receiving unit, thereby generating a profile and Bright line of the measurement light and Composite image data showing a first composite image in which the profiles are superimposed and displayed, and the first composite image and the observation image are displayed.

Advantages of the Invention

[0028] According to the present invention, it is possible to easily perform position adjustment of the optical displacement meter with respect to the measurement object without reducing the measurement accuracy of the profile.

Brief Description of the Drawings

[0029] [Figure 1] It is a block diagram showing the configuration of the optical displacement meter according to the first embodiment. [Figure 2] It is an external perspective view showing the imaging head of FIG. 1. [Figure 3] It is a bottom view showing the imaging head of FIG. 1. [Figure 4] It is a diagram for explaining the arrangement of the laser light projecting section, the LED light projecting section, and the imaging section of FIG. 1. [Figure 5] It is a diagram for explaining the arrangement of the laser light projecting section, the LED light projecting section, and the imaging section of FIG. 1. [Figure 6] It is a diagram showing an example of the passing wavelength band of the optical filter. [Figure 7] It is a diagram showing the relationship between the irradiation position of the measurement light on the surface of the workpiece and the incident position of the light on the light receiving section. [Figure 8] It is a diagram showing the relationship between the irradiation position of the measurement light on the surface of the workpiece and the incident position of the light on the light receiving section. [Figure 9] It is a diagram showing the relationship between the irradiation position of the measurement light on the surface of the workpiece and the incident position of the light on the light receiving section. [Figure 10] It is a diagram showing the light reception amount distribution on the light receiving surface of the light receiving section. [Figure 11] It is a diagram showing the waveform data in one pixel column of FIG. 10. [Figure 12] It is a diagram showing all the peak positions in the light reception amount distribution of FIG. 10. [Figure 13] It is a diagram showing the profile data generated based on the peak positions of FIG. 12. [Figure 14] It is a diagram showing an example of the screen of the display section. [Figure 15] It is a diagram showing an example of the screen of the display section. [Figure 16] It is a diagram showing another display example of the image display area. [Figure 17] It is a diagram showing still another display example of the image display area. [Figure 18] It is a diagram showing a measurement image based on the measurement image data generated by the measurement image generation section. [Figure 19] It is a diagram showing a measurement image based on the observation image data generated by the observation image generation section. [Figure 20] It is a time chart of control pulses given to the imaging head. [Figure 21] It is a diagram showing an example of an exclusive control circuit. [Figure 22] It is a diagram showing another example of the housing. [Figure 23] It is a diagram showing still another example of the housing.

Mode for Carrying Out the Invention

[0030] [1] First Embodiment (1) Configuration of the Optical Displacement Meter Hereinafter, as an optical displacement meter according to an embodiment of the present invention, an optical displacement meter of the light cutting method will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an optical displacement meter according to the first embodiment. As shown in FIG. 1, the optical displacement meter 500 includes an imaging head 100, a processing device 200, an input unit 300, and a display unit 400. The imaging head 100 is configured to be detachable from the processing device 200. The imaging head 100 and the processing device 200 may be integrally configured.

[0031] The imaging head 100 includes a laser light projecting unit 110, an LED light projecting unit 120, and an imaging unit 130. The laser light projecting unit 110 is configured to be able to irradiate a strip-shaped measurement light extending in one direction to a measurement object (hereinafter referred to as a workpiece W). Instead of the strip-shaped measurement light extending in one direction, the laser light projecting unit 110 may be configured to be able to irradiate the workpiece W with a dot-shaped light scanned in one direction as the measurement light. The LED light projecting unit 120 is configured to be able to irradiate the workpiece W with uniform observation light. The imaging unit 130 receives the measurement light or observation light reflected by the workpiece W and outputs the received light amount distribution.

[0032] The processing device 200 includes a storage unit 201 and a control unit 202. The storage unit 201 is composed of a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk, a semiconductor memory, etc., and stores a measurement program. The control unit 202 is, for example, a CPU (Central Processing Unit).

[0033] Further, as a functional unit, the processing device 200 includes a setting unit 210, a head control unit 220, a measurement image generation unit 230, an observation image generation unit 240, a profile generation unit 250, a measurement unit 260, and a display processing unit 270. By executing the measurement program stored in the storage unit 201 by the control unit 202, the functional units of the processing device 200 are realized. Part or all of the functional units of the processing device 200 may be realized by hardware such as an electronic circuit.

[0034] The display processing unit 270 of the processing device 200 can switch the display of an observation image, a measurement image, and a composite image (each described later). The setting unit 210 sets the image to be displayed on the display unit 400 to any one of an observation image, a measurement image, and a composite image based on the designation given by the input unit 300.

[0035] Also, the setting unit 210 sets imaging conditions such as the brightness (intensity) of the measurement light, the brightness (intensity) of the observation light, or the exposure period of the imaging unit 130 based on the designation given by the input unit 300. The user can specify 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 light projection unit 110, the LED light projection unit 120, and the imaging unit 130 based on the imaging conditions set in the setting unit 210.

[0036] The measurement image generation unit 230 generates measurement image data indicating an image of the workpiece W (hereinafter referred to as a measurement image) when the measurement light is irradiated, based on the light reception amount distribution of the measurement light output by the imaging unit 130. The observation image generation unit 240 generates observation image data indicating an image of the workpiece W (hereinafter referred to as an observation image) when the light including the observation light is irradiated, based on the light reception amount distribution of the light including the observation light output by the imaging unit 130.

[0037] Note that the "observation image" in the present invention is an image indicated by image data generated by irradiating the workpiece W with observation light by the LED light projecting unit 120 and imaging the workpiece W by the imaging unit 130, regardless of whether the laser light projecting unit 110 is in a lit state. The "measurement image" in the present invention is an image indicated by image data generated by irradiating the workpiece W with measurement light by the laser light projecting unit 110 and imaging the workpiece W by the imaging unit 130 while the LED light projecting unit 120 is not irradiating the workpiece W with observation light. The "synthetic image" in the present invention is an image indicated by image data generated so as to superimpose and display a profile on the measurement image or the observation image.

[0038] The profile generation unit 250 generates profile data indicating the profile of the workpiece W based on the measurement image data generated by the measurement image generation unit 230. The measurement unit 260 performs a measurement process based on the profile data generated by the profile generation unit 250. Here, the measurement process is a process of calculating the dimensions (displacements) of an arbitrary part of the surface of the workpiece W based on the profile data. The user can specify a desired part of the workpiece W for which the measurement process is to be performed on the profile data by operating the input unit 300.

[0039] The display processing unit 270 causes the display unit 400 to display various images such as the measurement image, the observation image, the profile, or an image showing the measurement result by the measurement unit 260. The user can specify the displayed image to the display processing unit 270 or 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.

[0040] The input unit 300 includes a keyboard and a pointing device and is configured to be operable by the user. As the pointing device, a mouse, a joystick, or the like is used. Also, a dedicated console may be used as the input unit 300. The display unit 400 is constituted by, for example, a liquid crystal display panel or an organic EL (electroluminescence) panel.

[0041] (2) Imaging head FIG. 2 is an external perspective view showing the imaging head 100 of FIG. 1. FIG. 3 is a bottom view showing the imaging head 100 of FIG. 1. As shown in FIGS. 2 and 3, in the imaging head 100, the housing 140 has an external shape and an internal space of a substantially rectangular parallelepiped. The laser light projection unit 110, the LED light projection unit 120, and the imaging unit 130 are accommodated in the internal space of the housing 140. In the housing 140, a width direction, a longitudinal direction, and a vertical direction that are orthogonal to each other are defined.

[0042] A lower surface 141 and an inclined surface 142 are provided at the lower part of the housing 140. Further, a concave portion 143 that is recessed upward is formed at a substantially central portion in the longitudinal direction at the lower part of the housing 140. The lower surface 141 is substantially orthogonal to the vertical direction and faces downward. The inclined surface 142 is located in the concave portion 143 and faces obliquely downward. A measurement window 144 and an observation window 145 are formed in the lower surface 141. A light receiving window 146 is formed in the inclined surface 142.

[0043] The measurement window 144 has a substantially rectangular shape extending in the width direction, and is arranged so as to be able to transmit downward the strip-shaped measurement light from the laser light projection unit 110 of FIG. 1 accommodated in the housing 140. The observation window 145 has a substantially square shape, and is arranged at a substantially central portion in the width direction so as to be able to transmit downward the observation light from the LED light projection unit 120 of FIG. 1 accommodated in the housing 140. The light receiving window 146 has a circular shape, and is arranged at a substantially central portion in the width direction so as to be able to transmit light from obliquely below to the imaging unit 130 of FIG. 1 accommodated in the housing 140.

[0044] In this example, the observation window 145 is located between the measurement window 144 and the concave portion 143. That is, the observation window 145 is provided at a position closer to the light receiving window 146 than the measurement window 144 in the longitudinal direction. According to this arrangement, it is possible to prevent the housing 140 from becoming larger in the longitudinal direction.

[0045] Figures 4 and 5 are diagrams for explaining the arrangements of the laser light projecting unit 110, the LED light projecting unit 120, and the imaging unit 130 in FIG. 1. FIG. 4 shows the imaging head 100 viewed in the longitudinal direction, and FIG. 5 shows the imaging head 100 viewed in the width direction. As shown in FIG. 4, the laser light projecting unit 110 includes an LD (laser diode) 111, a collimator lens 112, and light projecting lenses 113 and 114.

[0046] The LD 111, the collimator lens 112, and the light projecting lenses 113 and 114 are arranged in the housing 140 so as to be arranged in this order from above downward. Below the light projecting lens 114, the measurement window 144 in FIG. 2 is located. The light projecting axis of the laser light projecting unit 110 formed by the LD 111, the collimator lens 112, and the light projecting lenses 113 and 114 is substantially parallel in the vertical direction and substantially orthogonal to the lower surface 141 of the housing 140.

[0047] The LD 111 emits downward, as measurement light, laser light having a wavelength of, for example, 400 nm or more and 480 nm or less. The collimator lens 112 transmits the measurement light emitted by the LD 111 while parallelizing it. The light projecting lenses 113 and 114 transmit the measurement light parallelized by the collimator lens 112 while expanding it in a strip shape in the width direction. The measurement light expanded in a strip shape by the light projecting lenses 113 and 114 passes through the measurement window 144 and irradiates the workpiece W.

[0048] The LED light projecting unit 120 is realized by an LED and is arranged in the housing 140 so as to be close to the observation window 145 in FIG. 2. The light projecting axis of the LED light projecting unit 120 is substantially parallel in the vertical direction and substantially orthogonal to the lower surface 141 of the housing 140. That is, it is substantially parallel to the light projecting axis of the laser light projecting unit 110. The LED light projecting unit 120 emits downward, as observation light, light having a wavelength of 400 nm or more and 480 nm or less. The observation light emitted by the LED light projecting unit 120 passes through the observation window 145 and irradiates the workpiece W.

[0049] As shown in FIG. 5, the imaging unit 130 includes a light receiving unit 131, a light receiving lens 132, and an optical filter 133. The light receiving unit 131 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) sensor and has a light receiving surface on which a plurality of light receiving elements are two-dimensionally arranged. The light receiving elements are, for example, photodiodes. The light receiving unit 131 and the light receiving lens 132 are arranged in the housing 140 such that the plane including the light receiving surface of the light receiving unit 131 and the plane including the main surface of the light receiving lens 132 satisfy the shim-proof condition with respect to the light projection axis of the laser light projection unit 110.

[0050] The light receiving lens 132 is provided close to the light receiving window 146 in FIG. 2 and with its main surface substantially parallel to the inclined surface 142 of the housing 140. According to these arrangements, the housing 140 can compactly accommodate the laser light projection unit 110, the LED light projection unit 120, and the imaging unit 130 while satisfying the above-mentioned shim-proof condition.

[0051] The light receiving lens 132 guides the measurement light or the observation light reflected from the workpiece W and transmitted through the light receiving window 146 to the light receiving unit 131 while focusing it. The light receiving unit 131 receives the measurement light or the observation light focused by the light receiving lens 132 through the optical filter 133 and outputs the light reception amount distribution.

[0052] The optical filter 133 is, for example, a band-pass filter and is attached to the light receiving surface of the light receiving unit 131. FIG. 6 is a diagram showing an example of the passing wavelength band of the optical filter 133. The horizontal axis in FIG. 6 indicates the wavelength of light, and the vertical axis indicates the normalized light intensity. Also, the wavelength distribution of the measurement light is shown by a solid line, the wavelength distribution of the observation light is shown by a dotted line, and the passing wavelength band of the optical filter 133 is shown by a hatching pattern.

[0053] In the example of FIG. 6, the wavelength of the measurement light is about 450 nm, and the central wavelength of the observation light substantially coincides with the wavelength of the measurement light. The optical filter 133 passes light near a wavelength of 450 nm and blocks light in other wavelength bands. In this case, components of the measurement light or the observation light having a wavelength substantially equal to the measurement light pass through the optical filter 133 and are received by the light receiving unit 131. On the other hand, components of the observation light having a wavelength separated from the measurement light and other disturbance light are blocked by the optical filter 133.

[0054] In this case, profile data and observation image data can be accurately generated. Further, since the measurement light has a wavelength of 400 nm or more, the user can easily recognize the measurement light with the naked eye. Thereby, the usability of the optical displacement meter 500 is improved. Furthermore, since the measurement light has a wavelength of 480 nm or less, profile data can be generated with high accuracy.

[0055] Note that, in the example of FIG. 6, the central wavelength of the observation light substantially coincides with the wavelength of the measurement light, but the embodiment is not limited thereto. As long as the wavelength of the measurement light is included within the wavelength distribution range of the observation light, the central wavelength of the observation light does not have to coincide with the wavelength of the measurement light. Further, as long as 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 passing wavelength band of the optical filter 133 may be narrower or wider than the example of FIG. 6.

[0056] (3) Generation of Profile Data FIG. 7 is an external perspective view of the imaging head 100 and the workpiece W. FIGS. 8 and 9 are diagrams showing the relationship between the irradiation position of the measurement light on the surface of the workpiece W and the incident position of the light on the light receiving unit 131. In FIGS. 7 to 9, two directions orthogonal to each other in the horizontal plane are defined as the X1 direction and the Y1 direction, and are indicated by arrows X1 and Y1, respectively. Further, the vertical direction is defined as the Z1 direction and is indicated by an arrow Z1. The X1 direction, the Y1 direction, and the Z1 direction correspond to the width direction, the longitudinal direction, and the vertical direction of the housing 140 in FIG. 2, respectively. In FIGS. 8 and 9, two directions orthogonal to each other on the light receiving surface of the light receiving unit 131 are defined as the X2 direction and the Z2 direction, and are indicated by arrows X2 and Z2, respectively.

[0057] In the example of FIG. 7, a groove having a trapezoidal cross section extending in the Y1 direction is formed on the surface of the workpiece W. The imaging head 100 irradiates the surface of the workpiece W with a strip-shaped measurement light along the X1 direction. Hereinafter, the linear region of the surface of the workpiece W irradiated with the strip-shaped measurement light is referred to as an irradiation region T1. As shown in FIG. 8, the measurement light reflected in the irradiation region T1 enters the light receiving unit 131 through the light receiving lens 132. In this case, if the reflection position of the light in the irradiation region T1 is different in the Z1 direction, the incident position of the reflected light on the light receiving unit 131 is different in the Z2 direction.

[0058] Further, as shown in FIG. 9, if the reflection position of the light in the irradiation region T1 is different in the X1 direction, the incident position of the reflected light on the light receiving unit 131 is different in the X2 direction. Thereby, the incident position of the light in the Z2 direction of the light receiving unit 131 represents the position (height) in the Z1 direction of the irradiation region T1, and the incident position of the light in the X2 direction of the light receiving unit 131 represents the position in the X1 direction in the irradiation region T1.

[0059] FIG. 10 is a diagram showing the light reception amount distribution on the light reception surface of the light receiving unit 131. As shown in FIG. 10, a plurality of pixels p of the light receiving unit 131 are two-dimensionally arranged along the X2 direction and the Z2 direction. Each of a plurality of columns of pixels p along the Z2 direction is called a pixel column SS. The light reflected by the irradiation region T1 in FIG. 7 mainly enters the light reception region R1 shown in FIG. 10. Thereby, the light reception amount of the pixel p located in the light reception region R1 increases. Measurement image data is generated by the measurement image generation unit 230 in FIG. 1 based on the light reception amount distribution of the measurement light in FIG. 10.

[0060] Waveform data for each pixel column SS is generated by the profile generation unit 250 in FIG. 1 based on the measurement image data. FIG. 11 is a diagram showing the waveform data in one pixel column SS in FIG. 10. In FIG. 11, the horizontal axis indicates the position in the Z2 direction, and the vertical axis indicates the light reception amount. As shown in FIG. 11, a peak P (maximum value) corresponding to the light reception region R1 in FIG. 10 appears in the waveform data in one pixel column SS. The position of the peak P in the Z2 direction (hereinafter referred to as the peak position PP) indicates the height of the surface (reflection surface) of the work W in the irradiation region T1.

[0061] One peak position PP is detected by the profile generation unit 250 in each of the plurality of waveform data corresponding to the plurality of pixel columns SS. Further, based on the plurality of peak positions PP, profile data indicating the profile of the work W (the shape of the irradiation region T1) is generated by the profile generation unit 250.

[0062] FIG. 12 is a diagram showing all the peak positions PP in the light reception amount distribution in FIG. 10. FIG. 13 is a diagram showing the profile data generated based on the peak positions PP in FIG. 12. As shown in FIGS. 12 and 13, all the detected peak positions PP are shown as a continuous line, whereby profile data indicating the profile of the work W is generated.

[0063] (4) Setting of Image Acquisition Conditions As described above, the optical displacement meter 500 can switch the display of the observation image, the measurement image, and the composite image and specify the image generation conditions. In the present embodiment, the LED light projecting unit 120 in FIG. 1 is controlled to light up simultaneously with the laser light projecting unit 110. That is, the observation light and the measurement light are emitted simultaneously. Here, since the conditions of shine proof are satisfied for the laser light projecting unit 110 and the imaging unit 130, even when there are portions with significantly different heights on the workpiece W, the focus of the light receiving unit 131 coincides with all of the measurement positions by the measurement light on the workpiece W. Therefore, observation image data showing the irradiated portion of the measurement light on the workpiece W and its vicinity region is generated.

[0064] Based on the generated observation image data, an observation image is displayed on the display unit 400. FIGS. 14 and 15 are diagrams showing an example of the screen of the display unit 400. As shown in FIG. 14, an image display area 410 and a designation reception area 420 are provided side by side on the screen of the display unit 400. Various images can be displayed in the image display area 410. In the examples of FIGS. 14 and 15, an observation image is displayed in the image display area 410.

[0065] A GUI (Graphical User Interface) including operation buttons, operation bars, numerical input fields, etc. is displayed in the designation reception area 420. The user can specify the imaging conditions by operating the GUI in the designation reception area 420 using the input unit 300 in FIG. 1. The setting unit 210 in FIG. 1 sets the imaging conditions based on the designations given through the designation reception area 420.

[0066] As shown in FIG. 14, in the observation image, the irradiated portion of the measurement light on the work W appears clearly as a bright line. However, in the example of FIG. 14, since the brightness of the observation light is low, the area near the irradiated portion of the measurement light on the work W does not appear clearly. In this case, the user increases the brightness of the observation light by operating the GUI of the designated reception area 420. As a result, as shown in FIG. 15, an observation image in which the irradiated portion of the measurement light on the work W and its adjacent area appear clearly and other areas become unclear can be displayed on the image display area 410.

[0067] While visually recognizing the observation image displayed on the image display area 410, the user adjusts the position of the imaging head 100 and the work W so that a desired portion of the work W in the observation image becomes clear. Thereby, the position adjustment of the imaging head 100 with respect to the work W can be easily performed. Further, the user can more precisely adjust the position of the imaging head 100 with respect to the work W by adjusting the position of the imaging head 100 or the work W so that the bright line overlaps a desired portion of the work W in the observation image.

[0068] It is important that the irradiated portion of the measurement light on the work W appears clearly in the observation image, and the degree to which the area near the irradiated portion should appear clearly varies depending on the observation situation. Therefore, when the automatic lighting of the LED light projecting unit 120 and the automatic adjustment of the brightness of the observation light are performed, the usability of the optical displacement meter 500 is rather deteriorated. Thus, in this example, the automatic lighting of the LED light projecting unit 120 is not performed, and the LED light projecting unit 120 lights up in response to the instruction of the user. Further, the automatic adjustment of the brightness of the observation light is not performed, and the brightness of the observation light is adjusted in response to the manual designation of the user.

[0069] In the image display area 410, it is possible to display other images that facilitate the position adjustment of the imaging head 100 with respect to the work W. FIG. 16 is a diagram showing another display example of the image display area 410. The display processing unit 270 in FIG. 1 generates first composite image data indicating a first composite image in which a profile is superimposed on a measurement image by synthesizing the measurement image data and the profile data. In the image display area 410 of FIG. 16, a first composite image based on the first composite image data is displayed.

[0070] When the measurement light is multiply reflected on the surface of the work W, or when the measurement light penetrates into the work W, the light reflected from a position other than the surface of the work W is received by the imaging unit 130. As a result, a profile different from the actual cross-sectional shape of the work W is obtained. In such a case, as shown in FIG. 16, by superimposing and displaying the bright line of the measurement light and the profile, the user can grasp which part is the cause and why the correct profile cannot be obtained.

[0071] In response to an instruction from the input unit 300 in FIG. 1, the display processing unit 270 switches between the observation image in FIG. 15 and the first composite image in FIG. 16 and causes them to be displayed in the image display area 410. The work W may be formed such that a plurality of parts having similar structures are arranged in the Y1 direction (the longitudinal direction of the housing 140), for example, like an integrated circuit chip. Even in such a case, the user can easily recognize whether the measurement light is irradiated to a desired part of the work W by visually recognizing the irradiated part of the measurement light on the work W in the observation image and visually recognizing the profile in the first composite image.

[0072] FIG. 17 is a diagram showing still another display example of the image display area 410. The display processing unit 270 generates second composite image data showing a second composite image in which a profile is superimposed on an observation image by synthesizing the observation image data and the profile data. In the example of FIG. 17, the second composite image is displayed in the image display area 410. By visually recognizing the observation image and the profile in the second composite image, the user can easily recognize whether or not the measurement light is irradiated to a desired portion of the work W.

[0073] (5) Effect In the optical displacement meter 500 according to the present embodiment, the measurement light is irradiated onto the work W by the laser light projecting unit 110, and the measurement light reflected from the work W is focused by the light receiving lens 132. The measurement light focused by the light receiving lens 132 is received by the light receiving unit 131, and the light reception amount distribution is output. Profile data is generated based on the light reception amount distribution of the measurement light output by the light receiving unit 131.

[0074] Further, the observation light is irradiated onto the work W by the LED light projecting unit 120, and the observation light reflected from the work W is focused by the light receiving lens 132. The observation light focused by the light receiving lens 132 is received by the light receiving unit 131, and the light reception amount distribution is output. Observation image data is generated based on the light reception amount distribution of the observation light output by the light receiving unit 131.

[0075] Here, the laser light projecting unit 110, the light receiving unit 131, and the light receiving lens 132 are arranged so that the plane including the light receiving surface of the light receiving unit 131 and the plane including the principal surface of the light receiving lens 132 satisfy the Schimpflug condition with respect to the light projection axis of the laser light projecting unit 110. In this case, even when there are portions having greatly different heights on the work W, the focus of the light receiving unit 131 coincides with all of the measurement positions by the measurement light on the work W. Therefore, the profile data is generated with high accuracy.

[0076] In addition, observation image data showing an observation image in which the focus of the light receiving unit 131 coincides with the measurement position by the measurement light on the workpiece W is generated. As a result, the measurement position by the measurement light on the workpiece W appears clearly in the observation image. Further, the observation image data shows a natural observation image of the workpiece W that is recognized when the user visually recognizes the workpiece W from above.

[0077] Therefore, the user can easily adjust the position of the imaging head 100 with respect to the workpiece W by adjusting the position of the imaging head 100 or the workpiece W so that the desired portion of the workpiece W in the observation image becomes clear. As a result, the position adjustment of the optical displacement meter 500 with respect to the workpiece W can be easily performed without degrading the measurement accuracy of the profile.

[0078] [2] Second Embodiment Hereinafter, differences between the optical displacement meter 500 according to the second embodiment and the optical displacement meter 500 according to the first embodiment will be described. The optical displacement meter 500 according to the present embodiment has the same configuration as the optical displacement meter 500 shown in FIG. 1 according to the first embodiment. In the present embodiment, the head control unit 220 controls the laser light projecting unit 110 and the LED light projecting unit 120 to light alternately. Further, the measurement image data and the observation image data are alternately generated by the measurement image generation unit 230 and the observation image generation unit 240.

[0079] FIG. 18 is a diagram showing a measurement image based on the measurement image data generated by the measurement image generation unit 230. FIG. 19 is a diagram showing an observation image based on the observation image data generated by the observation image generation unit 240. As shown in FIG. 18, in the measurement image, the irradiated portion of the measurement light on the workpiece W appears as a bright line. On the other hand, as shown in FIG. 19, in the observation image of the present embodiment, no bright line indicating the irradiated portion of the measurement light on the workpiece W appears.

[0080] The display processing unit 270 causes the measurement image in FIG. 18 and the observation image in FIG. 19 to be alternately and repeatedly displayed on the display unit 400. While visually recognizing the alternately displayed measurement image and observation image, the user adjusts the position of the imaging head 100 or the work W so that the bright line in the measurement image overlaps the desired portion of the work W in the observation image. Thereby, the position adjustment of the imaging head 100 with respect to the work W can be easily and precisely performed.

[0081] The display processing unit 270 may switch the display between the measurement image and the observation image, for example, at a frequency of 10 times or more per second. In this case, the user can hardly recognize the switching of the display between the measurement image and the observation image. Therefore, the user is recognized as if an image similar to the case where the laser light projection unit 110 and the LED light projection unit 120 are lit simultaneously (that is, the observation image in FIG. 15) is being displayed on the display unit 400. By visually recognizing such an image, the user can more efficiently adjust the position of the imaging head 100 with respect to the work W.

[0082] Alternatively, the display processing unit 270 may generate image data showing an image similar to the case where the laser light projection unit 110 and the LED light projection unit 120 are lit simultaneously by synthesizing the measurement image data and the observation image data, and cause the display unit 400 to display the image. Even in this case, by visually recognizing the image displayed on the display unit 400, the user can more efficiently adjust the position of the imaging head 100 with respect to the work W.

[0083] [3] Third Embodiment Hereinafter, differences between the optical displacement meter 500 according to the third embodiment and the optical displacement meter 500 according to the first embodiment will be described. The optical displacement meter 500 according to the third embodiment has the same configuration as the optical displacement meter 500 in FIG. 1 according to the first embodiment. In the present embodiment, the head control unit 220 controls the laser light projection unit 110 and the LED light projection unit 120 to alternately light up within the same exposure period of the imaging unit 130. Further, the observation image data is generated by the observation image generation unit 240.

[0084] Specifically, the head control unit 220 generates binary control pulses for controlling each of the laser light projecting unit 110, the LED light projecting unit 120, and the imaging unit 130 of the imaging head 100. The control pulse for controlling the imaging unit 130 is called an imaging pulse. The control pulse for controlling the laser light projecting unit 110 is called a measurement pulse. The control pulse for controlling the LED light projecting unit 120 is called an observation pulse.

[0085] The imaging unit 130 enters an exposure state in response to an imaging pulse at the "H" level, and enters a non-exposure state in response to an imaging pulse at the "L" level. The laser light projecting unit 110 enters a lighting state in response to a measurement pulse at the "H" level, and enters a non-lighting state in response to a measurement pulse at the "L" level. The LED light projecting unit 120 enters a lighting state in response to an observation pulse at the "H" level, and enters a non-lighting state in response to an observation pulse at the "L" level.

[0086] FIG. 20 is a time chart of the control pulses applied to the imaging head 100. As shown in FIG. 20, at the initial time point t0, each of the measurement pulse P1, the observation pulse P2, and the imaging pulse P3 is at the "L" level. Therefore, the laser light projecting unit 110 is in a non-lighting state, the LED light projecting unit 120 is in a non-lighting state, and the imaging unit 130 is in a non-exposure state.

[0087] At time point t1, the imaging pulse P3 rises to the "H" level, and the measurement pulse P1 rises to the "H" level. In this case, the imaging unit 130 enters an exposure state. Also, the laser light projecting unit 110 enters a lighting state, and the workpiece W is irradiated with measurement light. At time point t2, the measurement pulse P1 falls to the "L" level, and the observation pulse P2 rises to the "H" level. In this case, the laser light projecting unit 110 enters a non-lighting state. Also, the LED light projecting unit 120 enters a lighting state, and the workpiece W is irradiated with observation light.

[0088] At time t3, the imaging pulse P3 falls to the "L" level, and the observation pulse P2 falls to the "L" level. In this case, the imaging unit 130 enters a non-exposed state. Also, the LED light projection unit 120 turns off. This state is maintained until time t4. Thereafter, the operations from time t1 to time t4 are repeated.

[0089] The period between time t1 and time t3 is the exposure period. The imaging unit 130 outputs the received light amount distribution of the reflected light from the workpiece W received during the exposure period during the period between time t3 and time t4. Observation image data is generated by the observation image generation unit 240 based on the received light amount distribution output by the imaging unit 130. The display processing unit 270 causes the display unit 400 to display an observation image based on the observation image data generated by the observation image generation unit 240.

[0090] The observation image data of the present embodiment shows an observation image similar to the case where the laser light projection unit 110 and the LED light projection unit 120 are lit simultaneously (that is, the observation image in FIG. 15). Therefore, while visually recognizing the observation image displayed on the display unit 400, the user adjusts the position of the imaging head 100 or the workpiece W so that the bright line overlaps the desired portion of the workpiece W in the observation image. Thereby, the position adjustment of the imaging head 100 with respect to the workpiece W can be performed easily and precisely.

[0091] In the present embodiment, the laser light projection unit 110 and the LED light projection unit 120 are controlled so as not to be lit simultaneously. However, due to a failure of the head control unit 220 or the like, there is a possibility that the laser light projection unit 110 and the LED light projection unit 120 are lit simultaneously.

[0092] Here, it may be desired to limit the intensity of the light emitted from the imaging head 100 so as not to exceed a predetermined upper limit value. In the case of such a limitation, it is necessary to make the intensity of the measurement light smaller than the upper limit value so that the sum of the intensity of the measurement light and the intensity of the observation light does not exceed the upper limit value. In this case, since it is necessary to increase the exposure time of the imaging unit 130, the processing efficiency decreases.

[0093] On the other hand, when the laser light projection unit 110 and the LED light projection unit 120 are prohibited from lighting up simultaneously, the intensity of the measurement light can be maintained at the upper limit value. Therefore, it is not necessary to increase the exposure time of the imaging unit 130, and it becomes possible to prevent a decrease in processing efficiency. Thus, an exclusive control circuit that prohibits the laser light projection unit 110 and the LED light projection unit 120 from lighting up simultaneously may be further provided.

[0094] FIG. 21 is a diagram showing an example of the exclusive control circuit. As shown in FIG. 21, the exclusive control circuit 10 includes amplifier circuits 1 and 2, NOT circuits 3 and 4, an AND circuit 5, and an npn bipolar transistor 6 (hereinafter simply referred to as transistor 6). The input part of the amplifier circuit 1 and the input part of the NOT circuit 3 are connected to the terminal 221 of the head control unit 220 for outputting the measurement pulse P1. One input part of the AND circuit 5 is connected to the terminal 222 of the head control unit 220 for outputting the observation pulse P2. The output part of the NOT circuit 3 and the other input part of the AND circuit 5 are connected. The output part of the AND circuit 5 and the input part of the amplifier circuit 2 are connected.

[0095] The anode of the LD111 of the laser light projection unit 110 is connected to the output part of the amplifier circuit 1. The cathode of the LD111 is connected to the collector of the transistor 6. The emitter of the transistor 6 is grounded. The anode of the LD of the LED light projection unit 120 and the input part of the NOT circuit 4 are connected to the output part of the amplifier circuit 2. The cathode of the LED is grounded. The output part of the NOT circuit 4 is connected to the base of the transistor 6.

[0096] According to this exclusive control circuit 10, when the measurement pulse P1 is at the "H" level, a control pulse of the "L" level is given to the LED light projection unit 120 regardless of whether the observation pulse P2 is at the "H" level or the "L" level. Therefore, when the measurement pulse P1 and the observation pulse P2 simultaneously become the "H" level, the LED light projection unit 120 does not enter the lighting state. Thereby, the laser light projection unit 110 and the LED light projection unit 120 are prohibited from lighting up simultaneously. Such an exclusive control circuit may be provided in the optical displacement meter 500 according to the second embodiment. "L" level control pulse is applied. Therefore, when the measurement pulse P1 and the observation pulse P2 simultaneously become the "H" level, the LED light projection unit 120 does not enter the lighting state. Thereby, the laser light projection unit 110 and the LED light projection unit 120 are prohibited from lighting up simultaneously. Such an exclusive control circuit may be provided in the optical displacement meter 500 according to the second embodiment.

[0097] [4] Other embodiments (1) In the above embodiment, the recess 143 is formed in the housing 140, but the embodiment is not limited thereto. FIG. 22 is a diagram showing another example of the housing 140. As shown in FIG. 22, depending on the measurement distance between the imaging head 100 and the work W, the light receiving lens 132 may be located below the lower surface 141 of the housing 140. In such a case, the recess 143 may not be formed in the housing 140.

[0098] (2) In the above embodiment, the LED light projecting unit 120 is provided closer to the imaging unit 130 than the laser light projecting unit 110 in the longitudinal direction, but the embodiment is not limited thereto. FIG. 23 is a diagram showing still another example of the housing 140. As shown in FIG. 23, when the housing 140 may be slightly enlarged in the longitudinal direction, the LED light projecting unit 120 may be provided at a position farther from the imaging unit 130 than the laser light projecting unit 110 in the longitudinal direction. In this case, the observation window 145 is provided at a position farther from the light receiving window 146 than the measurement window 144 in the longitudinal direction.

[0099] (3) In the above embodiment, the measurement window 144 and the observation window 145 are separately provided on the lower surface 141 of the housing 140, but the embodiment is not limited thereto. Instead of the measurement window 144 and the observation window 145, a common window that transmits the measurement light and the observation light may be provided on the lower surface 141 of the housing 140.

[0100] (4) In the above embodiment, the bright line of the measurement light is superimposed on the observation image, but the embodiment is not limited thereto. The bright line of the measurement light may not be superimposed on the observation image. Even in this case, the user can easily adjust the position of the imaging head 100 with respect to the work W by adjusting the position of the imaging head 100 or the work W so that a desired portion of the work W in the observation image becomes clear while visually recognizing the observation image.

[0101] (5) In the above-described embodiment, the measurement light has a wavelength of 400 nm or more and 480 nm or less, but the embodiment is not limited thereto. When it is not necessary to visually confirm the irradiation portion of the measurement light, the measurement light may have a wavelength shorter than 400 nm. Alternatively, when the measurement accuracy of the profile hardly decreases, the measurement light may have a wavelength longer than 480 nm.

[0102] Further, the wavelength of the observation light and the pass wavelength band of the optical filter 133 may be changed according to the wavelength of the measurement light. Further, when almost no disturbance light enters the light receiving unit 131, the optical filter 133 may not be attached to the light receiving surface of the light receiving unit 131.

[0103] [5] Correspondence relationship between each component of the claims and each element of the embodiment In the above-described embodiment, the work W is an example of the measurement object, the optical displacement meter 500 is an example of the optical displacement meter, the laser light projecting unit 110 is an example of the laser light projecting unit, and the LED light projecting unit 120 is an example of the LED light projecting unit. The light receiving lens 132 is an example of the light receiving lens, the light receiving unit 131 is an example of the light receiving unit, the processing device 200 is an example of the processing device, the exclusive control circuit 10 is an example of the exclusive control circuit, and the housing 140 is an example of the housing. The lower surface 141 and the inclined surface 142 are examples of the first and second surfaces, respectively, and the concave portion 143 is an example of the concave portion. The measurement window 144 is an example of the measurement window, the observation window 145 is an example of the observation window, the light receiving window 146 is an example of the light receiving window, and the optical filter 133 is an example of the band-pass filter.

Explanation of reference numerals

[0104] 1, 2... Amplification circuit, 3, 4... NOT circuit, 5... AND circuit, 6... Transistor, 10... Exclusive control circuit, 100... Imaging head, 110... Laser light projecting unit, 111... LD, 112... Collimator lens, 113, 114... Light projecting lens, 120... LED light projecting unit, 130... Imaging unit, 131... Light receiving unit, 132... Light receiving lens, 140... Housing, 141... Lower surface, 142... Inclined surface, 143... Concave portion, 144... Measurement window, 145... Observation window, 146... Light-receiving window, 200... Processing device, 201... Memory unit, 202... Control unit, 210... Setting unit, 220... Head control unit, 230... Measurement image generation unit, 240... Observation image generation unit, 250... Profile generation unit, 260... Measurement unit, 270... Display processing unit, 300... Input unit, 400... Display unit, 410... Image display area, 420... Designation reception area, 500... Optical displacement meter, p... Pixel, P... Peak, P1... Measurement pulse, P2... Observation pulse, P3... Imaging pulse, PP... Peak position, R1... Light-receiving area, SS... Pixel column, T1... Irradiation area, W... Work

Claims

Claim 1 An optical displacement meter using a light sectioning method for measuring the profile of an object to be measured, a laser light projecting unit for irradiating the object to be measured with a strip-shaped laser beam having a first light projection axis and extending in a first direction, or a dot-shaped laser beam scanned in the first direction as measurement light, an LED light projecting unit for irradiating the object to be measured with uniform light as observation light, a light receiving lens for focusing the reflected light of the measurement light and the observation light from the object to be measured, a light receiving unit having a light receiving surface composed of a plurality of light receiving elements arranged two-dimensionally, receiving the light focused by the light receiving lens, and outputting a light reception amount distribution, a processing device for executing a process of generating profile data indicating the profile of the object to be measured based on the light reception amount distribution of the measurement light output by the light receiving unit during measurement, and a process of generating observation image data indicating an image of the object to be measured irradiated with the observation light as an observation image based on the light reception amount distribution of the observation light output by the light receiving unit, the laser light projecting unit, the light receiving unit, and the light receiving lens are arranged such that a plane including the light receiving surface and a plane including the principal surface of the light receiving lens satisfy the Scheimpflug condition with respect to the first light projection axis, so that observation image data indicating an observation image in which the focus of the light receiving unit is relatively aligned is generated in a region near the measurement position irradiated with the measurement light during the measurement, in the observation image generated by irradiating the observation light by the LED light projecting unit to a region wider in a second direction orthogonal to a plane formed by the direction of the first light projection axis and the first direction than a region near the measurement position, the degree of coincidence of the focus of the light receiving unit decreases as the distance from the region near the measurement position in the second direction increases. An optical displacement meter characterized by this. Claim 2 The processing device controls the laser light projecting unit and the LED light projecting unit so that the measurement light and the observation light are emitted simultaneously, and generates observation image data in which a bright line of the measurement light is superimposed and displayed at the measurement position irradiated with the measurement light on the object to be measured. The optical displacement meter according to claim 1. Claim 3 The processing device controls the laser light projecting unit and the LED light projecting unit so that the measurement light and the observation light are alternately emitted, and generates measurement image data that shows an image of a measurement object irradiated with the measurement light as a measurement image based on the light reception amount distribution of the measurement light output by the light receiving unit, and alternately executes the process of generating the measurement image data and the process of generating the observation image data. The optical displacement meter according to claim 1.

4. The processing device automatically switches between and displays a measurement image and an observation image. The optical displacement meter according to claim 3.

5. The processing device synthesizes the measurement image data with the observation image data and displays an observation image in which a bright line of the measurement light is superimposed on the measurement position irradiated with the measurement light on the measurement object. The optical displacement meter according to claim 3.

6. The processing device controls the laser light projecting unit and the LED light projecting unit so that the measurement light and the observation light are alternately emitted within the same exposure period of the light receiving unit, and generates observation image data showing an observation image in which a bright line of the measurement light is superimposed on the measurement position irradiated with the measurement light on the measurement object. The optical displacement meter according to claim 1.

7. The optical displacement meter according to any one of claims 3 to 6 further includes an exclusive control circuit configured to prohibit the simultaneous emission of the measurement light and the observation light.

8. Inside a housing having an internal space that houses the laser light projecting unit, the LED light projecting unit, the light receiving lens, and the light receiving unit, the LED light projecting unit has a second light projection axis substantially parallel to the first light projection axis of the laser light projecting unit. The housing A first surface substantially perpendicular to the first and second light projection axes, A second surface inclined with respect to the first surface, A measurement window provided on the first surface through which measurement light irradiated from the laser light projecting unit to the measurement object passes, An observation window provided on the first surface through which observation light irradiated from the LED light projecting unit to the measurement object passes, The optical displacement meter according to any one of claims 1 to 7, including a light receiving window provided on the second surface through which reflected light of the measurement light and the observation light from the measurement object passes.

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

10. Further includes a band-pass filter provided on the optical path of the reflected light from the measurement object, The laser light projecting unit emits measurement light having a wavelength of 400 nm or more and 480 nm or less. The LED light projecting unit emits observation light having a wavelength range including the wavelength of the measurement light, The optical displacement meter according to any one of claims 1 to 9, wherein the transmittance of the band-pass filter within the wavelength range of the measurement light is higher than the transmittance of the band-pass filter outside the wavelength range of the measurement light.

11. The processing device generates composite image data showing a first composite image in which a profile and a bright line of measurement light are superimposed by synthesizing measurement image data showing an image of a measurement object irradiated with measurement light as a measurement image and profile data based on the light reception amount distribution of the measurement light output by the light receiving unit, and displays the first composite image and the observation image. The optical displacement meter according to any one of claims 1 to 10.

12. An optical displacement meter using a light section method for measuring the profile of a measurement object, A laser light projecting unit for irradiating a measurement object with a strip-shaped laser beam having a first light projection axis and extending in one direction, or a dot-shaped laser beam scanned in the one direction as measurement light, An LED light projecting unit for irradiating a measurement object with uniform light as observation light, A light receiving lens for focusing the reflected light of the measurement light and the observation light from the measurement object, A light receiving unit having a light receiving surface composed of a plurality of two-dimensionally arranged light receiving elements, receiving the light focused by the light receiving lens, and outputting a light reception amount distribution, A process for generating profile data showing the profile of a measurement object based on the light reception amount distribution of the measurement light output by the light receiving unit during measurement, and a process for generating observation image data showing an image of the measurement object irradiated with the observation light as an observation image based on the light reception amount distribution of the observation light output by the light receiving unit, and a processing device for executing the processes, The laser light projecting unit, the light receiving unit, and the light receiving lens are arranged so that the plane including the light receiving surface and the plane including the principal surface of the light receiving lens satisfy the Scheimpflug condition with respect to the first light projection axis, whereby observation image data showing an observation image in which the focus of the light receiving unit is relatively aligned is generated in a region near the measurement position irradiated with the measurement light during the measurement. The processing device generates composite image data indicating a first composite image in which a profile and a bright line of measurement light are superimposed and displayed by synthesizing measurement image data indicating, as a measurement image, an image of a measurement object irradiated with measurement light based on the light reception amount distribution of the measurement light output by the light receiving unit and profile data, and displays the first composite image and the observation image. An optical displacement meter characterized by the above is provided.

Images