WO2022185753A1

WO2022185753A1 - Measuring device

Info

Publication number: WO2022185753A1
Application number: PCT/JP2022/001524
Authority: WO
Inventors: 潤 ▲高▼嶋; 正行荒川; 豊加藤; 雅之早川
Original assignee: オムロン株式会社
Priority date: 2021-03-01
Filing date: 2022-01-18
Publication date: 2022-09-09
Also published as: TWI801104B; JP2022132771A; TW202235815A

Abstract

Provided is a high-speed, high-precision measuring device. A measuring device 100 measures a distance to a target object, and is provided with: a light source 110 for projecting light; a mirror 129; a beam splitter 121 for splitting the light projected from the light source into measuring light to be guided to the target object and reference light to be guided to the mirror; an event based camera 130 for acquiring data by detecting a change in a brightness value of received light, for an interference wave between the reference light reflected by the mirror and the measuring light reflected by the target object; a processing unit 140 for measuring the distance to the target object on the basis of the interference wave data; and a control means for performing control to change a received light amount acquired by the event based camera.

Description

Measuring device

The present invention relates to a measuring device.

In recent years, there has been a demand for higher accuracy in the alignment of parts in the multi-layer stacking of semiconductor chips, the assembly of rotary actuators for hard disk drives, the assembly of camera modules built into smartphones, and the light distribution control of LEDs.

A measuring device using an optical system is known as a device for measuring and inspecting measurement objects including these parts.

Patent Document 1 discloses a technique related to an interferometric shape measuring device. The shape measuring apparatus specifies an interference pattern of the amount of light received that varies depending on the difference between the optical path length of the measurement light and the optical path length of the reference light, and obtains the surface shape of the object to be measured based on the interference pattern.

JP 2018-63153 A

However, the shape measuring apparatus disclosed in Patent Document 1 has a problem that high-speed measurement cannot be performed because it is necessary to move and measure a plurality of points and acquire and process a huge amount of data.

Therefore, an object of the present invention is to provide a high-speed and high-precision measuring device.

A measuring device according to one aspect of the present invention is a measuring device that measures a distance to an object, and includes a light source that projects light, a mirror, and a measuring device that guides the light projected from the light source to the object. The beam splitter splits the light into reference light guided to the mirror, and the interference waveforms of the reference light reflected by the mirror and the measurement light reflected by the object are detected by detecting changes in the received luminance value to acquire data. an event-based camera, a processing unit that measures the distance to an object based on interference waveform data, and a control unit that controls to change the amount of light received by the event-based camera.

According to this aspect, the event-based camera detects a change in the brightness value of the interference waveform of the reference light reflected by the mirror and the measurement light reflected by the object at each arranged pixel. Since the data of the interference waveform portion is acquired at the timing of the detection, the amount of data to be acquired can be reduced while acquiring the data necessary for measuring the distance to the object. That is, the measuring device can measure the object at high speed and with high accuracy.

In the above aspect, the control means may include a driving section that drives the mirror so as to change the optical path length difference between the measurement light and the reference light.

According to this aspect, the measuring device can measure the object at high speed and with high accuracy using the white interference measurement method.

In the above aspect, the control means may use a wavelength swept light source as the light source so that the wavelength of the light projected from the light source changes continuously.

According to this aspect, the measurement device can measure the object at high speed and with high accuracy by the wavelength sweeping measurement method.

The above aspect may include a log amplifier that calculates the amount of received light acquired by the event-based camera based on the polarity data, based on the accumulation of the polarity data.

According to this aspect, the log amp can use the increase/decrease in the amount of light received by the event-based camera as the polarity data, and can capture minute changes at high speed, thereby shortening the imaging time.

The above aspect may further include an adjustment unit capable of adjusting the amount of data processed by the event-based camera.

According to this aspect, since the adjustment unit adjusts the amount of data processed by the event-based camera, the event-based camera can appropriately process events even when events occur simultaneously in a plurality of pixels. .

In the above aspect, the adjustment unit may have an ROI function for reading out data in a predetermined partial area.

According to this aspect, the ROI function is used to set the area necessary for measuring the object as the area from which the data is read, so the object can be measured more appropriately.

In the above aspect, the adjustment unit includes a light-removing unit configured to guide the light irradiated to the predetermined partial region to the event-based camera and not to guide the light irradiated to the other region to the event-based camera. may contain.

According to this aspect, the light-removing section is arranged so as to guide the light irradiated to the predetermined partial area to the event-based camera and not to guide the light irradiated to the other area to the event-based camera. Therefore, it is possible to measure the object more appropriately with respect to the area of the object that is necessary for measurement.

In the above aspect, the light-shaping portion may be composed of a liquid crystal panel.

According to this aspect, using the liquid crystal panel, it is possible to configure the light-shaping portion including the transmissive region that transmits the light irradiated to the predetermined partial region and the light-shielding region that blocks the other region. .

In the above aspect, the light-shaping section may be arranged on the common optical path of the measurement light and the reference light.

According to this aspect, since the optical paths of the measurement light and the reference light have the same conditions, it is possible to reduce the possibility of affecting the interference accuracy.

In the above aspect, the predetermined partial area may be set in advance according to the shape of the object.

According to this aspect, according to the shape of the object, the area that is the characteristic portion of the object, the area that is to be measured, and the like are set as a predetermined partial area from which data is read or light is transmitted. Therefore, the object can be measured more appropriately.

According to the present invention, it is possible to provide a high-speed and highly accurate measuring device.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the measuring device 100 which concerns on 1st Embodiment of this invention. FIG. 4 is a schematic diagram showing how data is acquired by an event-based camera 130 used as an imaging device; FIG. 3 is a diagram showing how the surface shape of an object (distance to the surface) is measured by the measuring device 100 using the event-based camera 130 as an imaging device. 4 is a diagram showing changes (increases and decreases) in the amount of received light acquired by the event-based camera 130 as bipolar, and showing an envelope based on the accumulation of the bipolar data. FIG. FIG. 10 is a diagram showing an example of using a ROI (Region Of Interest) function as an adjustment unit capable of adjusting the amount of data processed by the event-based camera 130. FIG. FIG. 10 is a diagram showing an example of how an event-based camera 130 is used to teach an area from which data is to be read; FIG. 10 is a diagram showing an example of how drawing information is referred to and an area from which data is to be read is taught; FIG. 10 is a diagram showing an example of using a light blocking section as an adjustment section capable of adjusting the amount of data processed by the event-based camera 130. FIG. FIG. 2 is a schematic diagram showing a configuration in which light shielding units are arranged in the measurement apparatus 100 shown in FIG. 1; BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows a structure and a function of 100 A of measuring devices to which the measuring device 100 which concerns on 1st Embodiment of this invention is applied. It is a schematic diagram which shows the structure of the measuring device 200 which concerns on 2nd Embodiment of this invention.

Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. It should be noted that the embodiments described below are merely specific examples for carrying out the present invention, and are not intended to limit the interpretation of the present invention. Also, in order to facilitate understanding of the description, the same reference numerals are given to the same constituent elements in each drawing as much as possible, and redundant description may be omitted.

<First embodiment>
[Configuration of measuring device]
FIG. 1 is a schematic diagram showing the configuration of a measuring device 100 according to the first embodiment of the invention. As shown in FIG. 1, the measurement device 100 includes a light source 110, an optical system 120, an event-based camera 130, and a processing section 140. The optical system 120 includes a beam splitter 121, a plurality of lenses 122-126 and a plurality of mirrors 127-129. Further, a driving section 150 (control means) for driving the mirror 129 is provided.

The light source 110 projects light L0. Light source 110 is typically a white light source, and may be, for example, an SLD (Super Luminescent Diode) light source. An SLD light source is a broadband light source that has the dual characteristics of light emitting diodes (LEDs) and semiconductor lasers (LDs), and has higher coherence than LED light sources and lower coherence than laser light. Note that the light source 110 emits light with a constant intensity, and the emission intensity does not change.

In addition, for the light source 110, for example, a halogen lamp, a white LED, and a white laser light source may be used.

The light L 0 projected from the light source 110 is transmitted through the lens 122 (for example, a collimator lens), collimated, and reflected by the mirror 127 . The light L0 reflected by the mirror 127 then enters the beam splitter 121 while being condensed by passing through the lens 123 .

The beam splitter 121 splits the light L0 into measurement light L1 guided to the object T and reference light guided to the mirror 129 . In other words, part of the light L0 is reflected by the beam splitter 121 (measurement light L1), and the remaining part of the light L0 is transmitted through the beam splitter 121 (reference light L2).

At the lens 124 (for example, the objective lens), the measurement light L1 is collimated by passing through the lens 124 . After that, the area of the object T is irradiated with the measurement light L1, and part of the measurement light L1 reflected by the object T is condensed by passing through the lens 124, and is again directed to the beam splitter 121. Incident.

On the other hand, the reference light L2 transmitted through the beam splitter 121 is transmitted through the lens 125 and collimated, reflected by the mirror 128, and irradiated onto the mirror 129. Mirror 129 is a so-called reference mirror.

Then, the reference light L2 reflected by the mirror 129 is reflected by the mirror 128, passes through the lens 125, is condensed, and enters the beam splitter 121 again.

The measurement light L1 reflected by the object T and incident on the beam splitter 121 and the reference light L2 reflected by the mirror 129 and incident on the beam splitter 121 interfere with each other, and pass through the lens 126 as interference light L3 to be collimated. and directed to the event-based camera 130 . The event-based camera 130 acquires data by detecting changes in the received luminance value for the interference waveform L3. Data acquired by the event-based camera 130 will be described later.

The processing unit 140 determines the distance to the target object T based on the data of the interference waveform L3 acquired by the event-based camera 130, the position of the mirror 129 (optical path length of the reference light L2) controlled by the driving unit 150 described later, and the like. Measure distance.

The drive unit 150 (control means) is an actuator composed of, for example, a voice coil motor (VCM) or the like, and moves the mirror 129 along the optical axis direction so as to change the optical path length of the reference light L2.

Thus, by changing the optical path length of the reference light L2 and changing the optical path length difference between the measurement light L1 and the reference light L2, an interference waveform is generated. Specifically, interference fringes can be observed around the position where the phase difference is 0, and an interference waveform is generated when the optical path lengths of the measurement light L1 and the reference light L2 match. A method of measuring an object using the interference waveform is, for example, a measurement method called a white interference method.

[About event-based cameras]
Here, the event-based camera 130 used as an imaging device will be described. The event-based camera 130 detects a change in the luminance value of the light received in each arrayed pixel, captures an interference waveform at the portion (pixel) where the change is detected at the timing of the detection, and detects the polarity of the luminance change. , to get time and coordinate data.

FIG. 2 is a schematic diagram showing how data is acquired by the event-based camera 130 used as an imaging device. As shown in FIG. 2, the event-based camera 130 detects a change in the luminance value of the received light in each arranged pixel, acquires the data of the interference waveform portion necessary for measurement at the timing of the detection, Other parts do not acquire data.

Conventionally, CMOS used as an image sensor acquires all data for each pixel, and the amount of data is enormous. In other words, the event-based camera 130 efficiently acquires the data of the interference waveform portion necessary for measuring the distance to the object T compared to the CMOS imaging device.

As described above, the event-based camera 130 is used as an imaging device to detect a change in the luminance value of the received light in each arrayed pixel, and to acquire the data of the interference waveform portion at the timing of the detection. The amount of data to be acquired can be reduced while acquiring the data necessary for measuring the distance to the object T.

FIG. 3 is a diagram showing how the surface shape of an object (distance to the surface) is measured by the measuring device 100 using the event-based camera 130 as an imaging device. As shown in FIG. 3, for die bonding and camera module measurement, the event-based camera 130 acquires data necessary for measurement at multiple points (on a single surface), and efficiently processes the necessary data at high speed ( reading, etc.). As a result, the measuring device 100 can measure the object at high speed and with high accuracy.

Furthermore, the event-based camera 130 detects changes in the luminance value of the received light in each arranged pixel, and acquires the data of the interference waveform portion at the timing of the detection. May contain an amplifier.

FIG. 4 is a diagram showing a change (increase or decrease) in the amount of received light acquired by the event-based camera 130 as bipolar, and an envelope curve based on the accumulation of the bipolar data. As shown in FIG. 4, the log amp captures minute changes in the amount of light received by the event-based camera 130, and uses the increases and decreases of the changes as bipolar data. Then, based on the accumulation of the bipolar data, the envelope of the received light amount distribution is identified and calculated as the received light amount acquired by the event-based camera 130 .

In this way, by including a log amplifier in the event-based camera 130, minute changes in the amount of light received by the event-based camera 130 can be captured at high speed, so the imaging time can be shortened.

As described above, the event-based camera 130 detects the occurrence of events such as changes in the amount of received light (luminance value) in each of the arranged pixels. Then, the event-based camera 130 acquires the data of the interference waveform portion at the pixels where it is detected that the event has occurred. Here, an adjusting unit is provided that can adjust the amount of data to be processed according to the capacity and performance of the event-based camera 130 so that even when events occur simultaneously in a plurality of pixels, it can be processed appropriately. It doesn't matter if

[About ROI function]
FIG. 5 is a diagram showing an example of using a ROI (Region Of Interest) function as an adjustment unit capable of adjusting the amount of data processed by the event-based camera 130. As shown in FIG. As shown in FIG. 5, of the maximum effective imaging area that can be imaged by the event-based camera 130, five rectangular areas 0 to 4 are set for reading out data, and data is not read out in the other areas. is set to

As a result, the event-based camera 130 acquires data by detecting a change in the luminance value of received light (occurrence of an event) in the pixels arranged in the rectangular areas 0 to 4, but in the other areas, Data is not acquired regardless of whether an event has occurred. The event-based camera 130 does not have to monitor whether an event has occurred in the other area.

Here, as an example, five rectangular areas 0 to 4 are set as the areas from which data is read, but the present invention is not limited to this. Alternatively, 6 or more may be set.

In addition, the size and shape of each rectangular area may be the same or different as the area from which data is read, and may have a shape other than a rectangle.

The area (for example, number, shape, position, etc.) from which data is read may be appropriately set according to the type, capacity, and performance of the event-based camera 130, and the type, shape, etc. of the object to be measured. The setting may be set in advance by the user or may be set by teaching.

FIG. 6 is a diagram showing an example of how the event-based camera 130 is used to teach the area from which data is to be read. For example, the event-based camera 130 is used as the measuring device 100 to measure the object T, and the area from which data is read is taught.

As shown in FIG. 6, the event-based camera 130 acquires data for all pixels in the maximum effective imaging area using the above-described white interference measurement method. For example, the event-based camera 130 may not be able to acquire data from all pixels at the same time depending on the type, capacity, performance, and the like, so it sequentially acquires data for each number of pixels that can be acquired at the same time. Here, since the purpose is to teach the area from which data is to be read, if detailed data is not required as the data to be acquired by the event-based camera 130, all pixels need not be targeted. . For example, as the data acquired by the event-based camera 130, data may be acquired in a thinned manner targeting pixels every several pixels.

Then, based on the data acquired by the event-based camera 130, 3D data of the target object T is generated, and the 3D data is referenced to set the area from which data is read. The area from which data is read out may be set by the user, for example, an area that is a characteristic portion of the object T, an area to be measured, or the like, or an area having a predetermined height is automatically set. You can do so.

Here, while using the above-described measurement method of the white interference method, the event-based camera 130 acquires data for all pixels in the maximum effective imaging area. I do not care.

For example, a half mirror or the like may be arranged so that the interference waveform L3 described using FIG. 1 can be received by a CMOS imaging device arranged separately from the event-based camera 130 . Accordingly, in teaching, the CMOS imaging device receives the interference waveform L3 reflected by the half mirror.

Then, if data is acquired for all pixels in the maximum effective imaging area using the CMOS imaging device while using the above-described white interference method measurement method, a 3D image of the object T can be obtained in the same manner as described with reference to FIG. Data is generated, and an area from which data is read is set by referring to the 3D data.

Furthermore, as a method of setting the area from which data is read by teaching, for example, drawing information such as CAD data of the object T may be imported, and the area from which data is to be read may be set by referring to the drawing information.

FIG. 7 is a diagram showing an example of how drawing information is referred to and an area from which data is to be read is taught. As shown in FIG. 7, the CAD data of the object T to be measured by the measuring apparatus 100 is captured as drawing information, and the captured drawing information is referenced to set the data reading area. The area from which data is read out may be set by the user, for example, an area that is a characteristic portion of the object T, an area to be measured, or the like, or an area having a predetermined height is automatically set. You can do so.

Alternatively, a distance image (image data whose pixel value is the height) may be generated, and the area for reading data may be set while referring to the distance image. There is an effect that the calculation cost of the display processing can be reduced compared to the case of treating as coordinate data in 3D space.

Alternatively, a grayscale image may be generated by performing rendering processing (generating a pseudo image by optical simulation) based on the 3D data, and area setting may be performed by referring to the grayscale image. This has the effect of reducing the calculation cost of display processing.

[About the light shielding part]
FIG. 8 is a diagram showing an example of using a light blocking section as an adjustment section capable of adjusting the amount of data processed by the event-based camera 130. As shown in FIG. As shown in FIG. 8, in the optical system 120, in the optical path of the light (L0, L1, L2) projected from the light source 110, a light blocking section including a region for transmitting the light and a region for blocking the light is arranged. . As shown in FIG. 8, when light is irradiated to the light irradiation region, four transmission regions are set as regions through which the light is transmitted, and light blocking regions are formed so that light is blocked in the other regions. is set.

As a result, since the event-based camera 130 receives light transmitted through the transmissive region, the pixels arranged corresponding to the transmissive region out of the plurality of pixels arranged in the event-based camera 130 receive the light. Data is acquired by detecting a change in luminance value (occurrence of an event). On the other hand, since the event-based camera 130 does not receive light that is blocked by the light-shielding region, among the plurality of pixels arranged in the event-based camera 130, the pixels arranged corresponding to the light-shielding region are It is not necessary to monitor the presence or absence of event occurrence.

Here, as an example, four circular transmissive regions are set as the regions through which light is transmitted. However, the present invention is not limited to this. , or five or more may be set.

In addition, the size and shape of each transmission region may be the same or different, and may be other than circular (eg, elliptical, oval, rectangular, etc.). It may be appropriately set according to the shape.

The transparent areas (for example, the number, shape, position, etc.) may be appropriately set according to the type, capacity, and performance of the event-based camera 130, and the type, shape, etc. of the object to be measured. may be set in advance by the user or may be set by teaching.

Regarding the setting of the transmission area, the teaching method for the area from which the above-described data is read can be applied. For example, with respect to the data readout regions shown in FIGS. 6 and 7, as the light shielding portion, the region corresponding to the data readout region may be set as the transparent region, and the other regions may be set as the light shielding regions. good.

Furthermore, a light shielding section having such a transmissive area and a light shielding area may be realized using, for example, a liquid crystal panel.

Here, the liquid crystal panel is composed of a polarizing filter (vertical), a glass substrate (individual electrode), a liquid crystal sandwiched between alignment layers, a glass substrate (common electrode), and a polarizing filter (horizontal). The linearly polarized light cannot pass through the polarizing filter (horizontal) while maintaining the polarization direction (light blocking state). On the other hand, when the polarization direction of light is bent by 90 degrees in the liquid crystal sandwiched between the alignment layers, the light can pass through the polarizing filter (horizontal) (non-light-shielding state). Electrodes on the glass substrate (individual electrode) and the glass substrate (common electrode) are provided for switching the liquid crystal between a light-shielding state and a non-light-shielding state.

FIG. 9 is a schematic diagram showing a configuration in which the light blocking section is arranged in the measuring device 100 shown in FIG. As shown in FIG. 9, a light blocking section 160 is arranged between the lens 122 and the mirror 127 .

The position where the light blocking portion 160 is arranged is not limited to between the lens 122 and the mirror 127. For example, between the light source 110 and the lens 122, between the mirror 127 and the lens 123, between the lens 123 and the beam splitter 121, between the beam splitter 121 and the lens 126, between the lens 126 and the event-based camera 130, or the like. It is sufficient if they are on a common optical path (on the optical paths of the lights L0 and L3).

By arranging the light shielding part 160, the irradiated light may be polarized and diffracted by the liquid crystal and the state may change. and the optical path of the reference light L2 under the same conditions, it is possible to reduce the possibility of affecting the interference accuracy.

Here, the liquid crystal panel has been described as an example of the light shielding portion having the transmission region and the light shielding region, but the light irradiated to the predetermined partial region is guided to the event base camera 130, and is irradiated to the other region. In order not to guide the light to the event-based camera 130, a DMD (digital micromirror device) may be used.

For example, a DMD is used for the mirror 127 that constitutes the measuring apparatus 100 shown in FIG. A DMD reflects light irradiated to a predetermined partial region and absorbs light irradiated to other regions. That is, it is possible to reflect the light irradiated to the predetermined partial area, make it enter the mirror 123 , and finally guide it to the event-based camera 130 .

In this way, the liquid crystal panel, DMD, and the like guide the light irradiated to a predetermined partial region to the event base camera 130, and block or absorb the light irradiated to the other region, thereby causing an event to occur. The reduction is performed so as not to lead to the base camera 130 . That is, it can be said that it is a light cutting portion that reduces a part of the irradiated light.

As described above, according to the measurement apparatus 100 according to the first embodiment of the present invention, the event-based camera 130 is used as an imaging element, and further, minute changes in the amount of received light are appropriately captured by the log amplifier, and the ROI function is performed. And the light blocker 160 appropriately adjusts the amount of data processed by the event-based camera 130 . As a result, the measuring device 100 can more appropriately measure the object T at high speed and with high accuracy.

In this embodiment, the optical system 120 is composed of a beam splitter 121, a plurality of lenses 122 to 126, a plurality of mirrors 127 to 129, etc., as shown in FIGS. is not limited to For example, the light L0 projected by the light source 110 is separated into the measurement light L1 and the reference light L2. Any optical system may be configured as long as it can be received by the camera 130 and a measurement method using the white interference method can be performed.

Further, in the present embodiment, the ROI function and the light shielding unit 160 are taken as an example of an adjustment unit capable of adjusting the amount of data processed by the event-based camera 130, and furthermore, an area for reading out data, a transparent area, a light shielding area, etc. Although teaching has been described, it is not limited to this. For example, the number of pixels in the event-based camera 130 may be reduced (reduced resolution) so that data can be acquired even if events occur simultaneously in all pixels.

[Application example]
FIG. 10 is a schematic diagram showing the configuration and functions of a measuring device 100A to which the measuring device 100 according to the first embodiment of the present invention is applied. As shown in FIG. 10, the measuring device 100A includes a light source 110, an optical system 120A, an event-based camera 130, and a CMOS imaging device 170. Although shown schematically in FIG. 10, the measuring apparatus 100A differs from the measuring apparatus 100 shown in FIG. 1 in that a CMOS imaging device 170 and a half mirror 171A are added.

The measuring device 100A basically measures the target object T by the white interference measurement method, as described in the measuring device 100 . The event-based camera 130 functions as an imaging element that acquires data about the object T in the Z-axis direction, as described for the measurement apparatus 100 .

Furthermore, in the measuring device 100A, the CMOS imaging device 170 receives the light reflected by the half mirror 171A and acquires image data of the target object T. More specifically, the CMOS imaging device 170 functions as an imaging device that acquires an image of the target object T by measurement on the XY axis plane.

As described above, according to the measurement apparatus 100A, by combining the image acquired by the CMOS imaging device 170 and the white interference measurement method using the event-based camera 130, the object T can be measured on the XYZ coordinate axes. It can be realized with one sensor.

Note that the event-based camera 130 may be used to fulfill the same role as the CMOS imaging device 170 . The event-based camera 130 detects changes in brightness, and there are types that output not only the polarity of the change in brightness but also the amount of change in brightness. In this case, it is possible to restore luminance information by performing integration processing.

Furthermore, the ROI function and the light-shaping portion described above may be used in combination. A plurality of ROI regions obtained by dividing the screen can be sequentially switched, captured, and synthesized to form a single image.

In this way, if the event-based camera 130 is used to perform the same role as the CMOS imaging device 170, there is no need to newly provide the CMOS imaging device 170, and the structure can be simplified.

It should be noted that the log amplifier, the ROI function, the light shielding section 160, and the like, which are applied in the measuring apparatus 100, can also be applied to the measuring apparatus 100A.

<Second embodiment>
Next, in a second embodiment of the present invention, a measurement apparatus using a wavelength swept light source as control means for changing the amount of light received by an event-based camera will be described. In addition, in this embodiment, mainly the configuration different from that of the first embodiment of the present invention will be described in detail, and the description of matters common to the first embodiment will be omitted or simplified.

FIG. 11 is a schematic diagram showing the configuration of a measuring device 200 according to the second embodiment of the invention. As shown in FIG. 11, the measurement device 200 includes a light source 210, an optical system 120, an event-based camera 130, and a processing section 140. The optical system 120 includes a beam splitter 121, a plurality of lenses 122-126 and a plurality of mirrors 127-129.

The measuring apparatus 100 according to the first embodiment of the present invention shown in FIG. , an interference waveform is generated by changing the optical path length difference between the measurement light L1 and the reference light L2, and the object T is measured by the white light interference method.

In the measurement apparatus 200 according to the present embodiment, a wavelength swept light source is used as the light source 210 as control means for controlling to change the amount of light received by the event-based camera 130, and the wavelength of the light projected from the light source 210 is is continuously changed to generate an interference waveform between the measurement light L1 and the reference light L2, and the object T is measured by a measurement method called a wavelength sweep method.

The light source 210 is, for example, a MEMS-VCSEL (Micro Electro Mechanical Systems-Vertical Cavity Surface Emitting Laser), DFB (Distributed feedback) laser, SSG-DBR (Super Structure Grating-Distributed Bragg reflector) laser, etc., as a wavelength swept light source. Used. It should be noted that the light source 210 emits light with a constant intensity, and the emission intensity does not change, like the light source 110 of the measuring device 100 according to the first embodiment.

The MEMS-VCSEL changes the lasing wavelength (wavelength sweep) by driving the resonant mirror with the MEMS, the DFB laser sweeps the wavelength by changing the drive current of the laser diode, and the SSG-DBR has two wavelengths. A diffraction grating called a distributed reflector is formed on one resonant mirror, and the wavelength is swept by injecting current.

The event-based camera 130 generates an interference waveform L3 between the measurement light L1 and the reference light L2, which is generated by varying the wavelength of the light projected from the light source 210, as described in the first embodiment of the present invention. Similarly, data is acquired by detecting a change in the luminance value of received light.

The processing unit 140 measures the distance to the object T based on the data of the interference waveform L3 acquired by the event-based camera 130, the wavelength (frequency) of the light projected from the light source 210, and the like.

As described above, according to the measuring apparatus 200 according to the second embodiment of the present invention, when measuring the object T by the wavelength sweeping measurement method using the wavelength swept light source as the light source 210, the event-based The camera 130 is used to detect the change in the luminance value of the light received by each arranged pixel, and the data of the interference waveform portion is acquired at the timing of the detection. The amount of data to be acquired can be reduced while acquiring necessary data.

Note that the log amplifier, the ROI function, the light shielding section 160, and the like, which are applied to the measuring apparatus 100 according to the first embodiment of the present invention, can also be applied to the measuring apparatus 200 according to the present embodiment.

Furthermore, like the measurement device 100A described using FIG. By combining the measurement method of the wavelength sweep method using the camera 130, the measurement of the object T on the XYZ coordinate axes can be realized with a single sensor.

The embodiments described above are for facilitating understanding of the present invention, and are not for limiting interpretation of the present invention. Each element included in the embodiment and its arrangement, materials, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. Also, it is possible to partially replace or combine the configurations shown in different embodiments.

[Appendix]
A measuring device (100, 200) for measuring a distance to an object,
a light source (110, 210) for projecting light;
a mirror (129);
a beam splitter (121) for splitting the light projected from the light source into measurement light directed to the object and reference light directed to the mirror;
an event-based camera (130) that acquires data by detecting a change in received luminance value with respect to an interference waveform of the reference light reflected by the mirror and the measurement light reflected by the object;
a processing unit (140) for measuring the distance to the object based on the data of the interference waveform;
a control means (150) for controlling to change the amount of light received by the event-based camera;
A measuring device (100, 200) comprising:

100, 100A, 200... Measuring device, 110, 210... Light source, 120, 120A... Optical system, 121... Beam splitter, 122 to 126... Lens, 127 to 129... Mirror, 130... Event base camera, 140... Processing unit, DESCRIPTION OF SYMBOLS 150... drive part, 160... light-shielding part, 170... CMOS imaging element, 171A... half mirror, L0-L3... light, T... object

Claims

A measuring device for measuring a distance to an object,
a light source that projects light;
with a mirror
a beam splitter that splits the light projected from the light source into measurement light guided to the object and reference light guided to the mirror;
an event-based camera that acquires data by detecting a change in received luminance value of an interference waveform between the reference light reflected by the mirror and the measurement light reflected by the object;
a processing unit that measures the distance to the object based on the data of the interference waveform;
control means for controlling to change the amount of light received by the event-based camera;
A measuring device.
The control means includes a drive unit that drives the mirror so as to change the optical path length difference between the measurement light and the reference light.
The measuring device according to claim 1.
The control means uses a wavelength swept light source as the light source so that the wavelength of the light projected from the light source changes continuously.
The measuring device according to claim 1 or 2.
A log amplifier that calculates the amount of light received by the event-based camera based on the accumulation of the polarity data, based on the increase or decrease in the amount of light received by the event-based camera,
The measuring device according to any one of claims 1 to 3.
further comprising an adjustment unit capable of adjusting the amount of data processed by the event-based camera;
The measuring device according to any one of claims 1 to 4.
The adjustment unit has an ROI function for reading data in a predetermined partial area,
The measuring device according to claim 5.
The adjustment unit includes a light cutting unit configured to guide light applied to a predetermined partial area to the event-based camera and not guide light applied to other areas to the event-based camera. ,
The measuring device according to claim 5 or 6.
The light-shaping portion is composed of a liquid crystal panel,
The measuring device according to claim 7.
The light-shaping section is arranged on a common optical path of the measurement light and the reference light,
The measuring device according to claim 7 or 8.
The predetermined partial area is set in advance according to the shape of the object,
The measuring device according to any one of claims 6 to 9.