Shape measurement system

Abstract

A shape measurement system is provided, with which accurate three-dimensional information can be acquired even when a measured object has a large unevenness on a measurement surface thereof. The shape measurement system of the present disclosure includes a single light source section, two light receiving sections installed offset from each other, and a single signal processing section. The light source section has a light source, a wave form control lens, and a scanning mechanism for scanning in a certain direction of a measurement object with measurement light that has passed through the wave form control lens. The light receiving section has a light receiving lens onto which incident light, which is a portion of the measurement light from the light source section reflected by the measurement object, is incident, an EVS which is an asynchronous imaging device serving as a light receiving element, an event issuing section that detects an event based on output data from the EVS and outputs event data, and a transmitting section for outputting the event data to the signal processing section. The signal processing section has a useless signal removing section for removing a useless signal caused by the incidence of secondary reflected light, and a three-dimensional calculating section for calculating a three-dimensional shape of the measurement object.

Description

Technical Field

[0001] This disclosure relates to a shape measurement system for measuring the shape of a target in three dimensions. Background Technology

[0002] In contrast to scanning (synchronous) imaging devices that perform imaging synchronously with a synchronization signal (such as a vertical synchronization signal), non-scanning (asynchronous) imaging devices, known as event-based vision sensors (EVS), are known (see, for example, Patent Document 1). As an event, the non-scanning imaging device can detect that the amount of brightness change of a pixel used for photoelectric conversion of incident light exceeds a predetermined threshold.

[0003] One example of the application of non-scanning imaging devices is a shape measurement device using the optical cross-section method. The optical cross-section method is used, particularly in inspection processes in factories, to detect shape anomalies in a target object (hereinafter referred to as the "object under test"). In shape measurement using the optical cross-section method, the width, height, etc., of the object under test are measured based on the shape of the imaging cross-section obtained when a linear beam of light is emitted from a light projection unit onto the object under test and the reflected light from the object under test, based on the emitted light, is received by a non-scanning imaging device.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-134271 Summary of the Invention

[0007] The problem to be solved by the present invention

[0008] As described above, for example, a shape measuring device using the optical cross-section method (which is one application of non-scanning imaging devices) measures shape by receiving light reflected from the object under test based on light emitted from the light projection section. However, in this case, due to ambient light, the degree of reflection of light emitted from the light projection section, etc., the imaged shape differs from the original shape, and therefore sometimes an accurate shape measurement cannot be performed.

[0009] For example, when reflected light (conventional reflected light) is captured at a measurement point and guided to the light receiver, there is a possibility that reflected light other than the conventional reflected light (secondary reflected light) may also enter the light receiver. In this case, especially for the object under test with large differences in unevenness, the difference in the optical path or the angle of travel between the secondary reflected light and the conventional reflected light may result in multiple different detection values, thus making it possible to perform inaccurate shape measurement.

[0010] The purpose of this disclosure is to obtain accurate three-dimensional information even for objects whose surface has large differences in unevenness.

[0011] Solution to the problem

[0012] This disclosure was made to achieve the above objectives, and a first aspect of this disclosure is a shape measurement system comprising: a light source unit that emits measurement light toward a measurement target;

[0013] A light receiving unit receives reflected light as measurement light reflected from the measurement target; a signal processing unit includes a three-dimensional shape calculation unit and an unwanted signal removal unit, wherein the three-dimensional shape calculation unit calculates the three-dimensional shape of the measurement target based on event data generated from the reflected light reflected from the measurement target and incident on the light receiving unit, and the unwanted signal removal unit removes unwanted signals generated when unwanted light other than the reflected light is incident on the light receiving unit from the outside; and a scanning mechanism scans the measurement target by moving the light source unit or the measurement target using measurement light projected from the light source unit onto the measurement target (sweep scan).

[0014] In a first aspect, the scanning mechanism may be disposed in the light source unit; the light source unit may include a light source and a waveform control lens for performing waveform control on the light from the light source; and

[0015] The light receiving unit may include: a light receiving lens; an event-based vision sensor (EVS), which is an asynchronous imaging element that captures the time change of reflected light passing through the light receiving lens in a beam of reflected light and outputs an event signal; an event publishing unit that detects events based on output data from the EVS and outputs event data; and a transmitting unit that outputs the event data to the signal processing unit.

[0016] In the first aspect, the light source unit can be a single light source unit; and

[0017] A first and a second light receiver, whose positions are offset from each other, can be configured as light receivers.

[0018] Furthermore, in the first aspect of this disclosure, a first light source portion and a second light source portion whose positions are offset from each other can be configured as light source portions;

[0019] The optical receiver can be a single optical receiver; and

[0020] The signal processing unit may include a control signal transmitting unit, which outputs control signals to each scanning mechanism at time intervals in a time-division manner for each pixel column.

[0021] Furthermore, in the first aspect of this disclosure, the first light source section and the second light source section can be configured as light source sections, the first light source section including a first light source emitting light of a first wavelength and the second light source section including a second light source emitting light of a second wavelength;

[0022] The optical receiver can be a single optical receiver;

[0023] EVS can include two segmentation regions in each pixel column, namely the first segmentation region and the second segmentation region;

[0024] In a measurement light emitted from a light source having two different wavelengths, the first wavelength light and the second wavelength light can be reflected by the measurement target, and the first segmentation region includes: a first filter having a first wavelength transmission characteristic that selectively transmits the reflected light of the first wavelength; and

[0025] The second segmentation region may include a second filter having a second wavelength transmission characteristic that allows light of the second wavelength to be selectively transmitted.

[0026] Furthermore, in the first aspect of this disclosure, a first light source section including a first light source and a second light source section including a second light source can be configured as light source sections;

[0027] The first light source may include: a first optical element, wherein the first optical element generates a first measurement light having a first polarization plane from light emitted from the first light source;

[0028] The second light source unit may include: a second optical element, wherein the light emitted from the second light source by the second optical element generates a second measurement light having a second polarization plane;

[0029] The optical receiver can be a single optical receiver;

[0030] EVS can divide each pixel column into two regions: a first segmentation region and a second segmentation region.

[0031] Alternatively, in the first and second measurement lights, a first reflected light with a first polarization plane and a second reflected light with a second polarization plane are reflected by the target and incident on the light receiving unit. The first segmented region may include a first film that selectively transmits the first reflected light; and

[0032] The second segmented region may include a second film that selectively transmits second reflected light.

[0033] Furthermore, in the first aspect, the first polarization plane can be linearly polarized light vibrating in the vertical direction, and

[0034] The second polarization plane can be linearly polarized light that vibrates in the horizontal direction.

[0035] Furthermore, in the first aspect of this disclosure, the light source unit may be a single light source unit; the light source in the light source unit may include: a splitting device for splitting light from the light source into at least three wavelength bands;

[0036] The optical receiver can be a single optical receiver;

[0037] EVS can divide each pixel column into three segments: the first segmentation region to the third segmentation region.

[0038] Among the three different wavelengths of measurement light emitted from the light source, the reflected light of the three wavelengths can be reflected by the measurement target, and the first segmentation region may include: a first filter having wavelength transmission characteristics that selectively transmit the reflected light of the first wavelength among the three wavelengths.

[0039] The second segmentation region may include a second filter having wavelength transmission characteristics that selectively transmit the reflected light of a second band among the three bands of reflected light reflected from the measurement target; and

[0040] The third segmentation region may include a third filter having wavelength transmission characteristics that selectively transmit the reflected light of the third band among the three bands of reflected light reflected by the measurement target.

[0041] Additionally, in this aspect, the segmentation device may include a prism that splits white light from a light source into three wavelength bands; and

[0042] The three wavelengths of light can be red, green, and blue.

[0043] Furthermore, in the first aspect, EVS can compare the signal voltage based on the time variation of the reflected light with a threshold voltage, and can output an event signal by determining whether the signal voltage is less than or greater than the threshold voltage.

[0044] The shape measurement system disclosed herein is configured to capture multiple independent optical data points corresponding to the shortest optical paths via multiple optical paths. Therefore, the data from the conventional reflected light (traveling on the shortest optical path) within the beam of reflected light captured from the optical paths have the same value, as long as the conventional reflected light is reflected at the same reflection point, regardless of the optical path traveled by the conventional reflected light. That is, the obtained shape (e.g., height) is uniquely determined regarding the physical shape (e.g., height) at the same point on the measured target (only one shape at the same location). Therefore, as long as the reflected light is conventional reflected light, the height value at the same point will not change regardless of the shortest optical path (path) traveled by the reflected light. Therefore, if a pair of identical data values ​​that should always exist is found, this data is obtained from the conventional reflected light, and thus, it is possible to reliably and accurately detect which data is the true data related to the measured surface. That is, even if unwanted secondary reflected light from the reflected and scattered light on the measured surface of the object enters the light receiver, erroneous distance measurements caused by data related to secondary reflected light can be suppressed. Furthermore, according to the shape measurement system of this disclosure, an event-based vision sensor (EVS) (which is an asynchronous imaging device) is used as a light receiving element, thus enabling high-speed and accurate shape measurement, although details will be described later. Attached Figure Description

[0045] Figure 1 This is a schematic diagram showing an outline of the configuration of a shape measurement system according to a first embodiment of the present disclosure.

[0046] Figure 2 This is a schematic configuration diagram showing the shape measurement system according to a second embodiment of the present disclosure.

[0047] Figure 3 This is a block diagram illustrating the configuration of an imaging apparatus according to a second embodiment of the present disclosure, showing a first configuration example.

[0048] Figure 4 This is an output diagram showing the time processing operation of the output signal in each pixel column (pixel array) of the optical receiver in a first configuration example of this disclosure.

[0049] Figure 5 This is a block diagram illustrating a configuration example of the imaging section of an imaging apparatus according to a first configuration example of the present disclosure.

[0050] Figure 6 This is a block diagram illustrating a configuration example of the pixel array section of the imaging section according to a first configuration example of the present disclosure.

[0051] Figure 7 This is a circuit diagram illustrating a circuit configuration example of pixels according to a first configuration example of this disclosure.

[0052] Figure 8 This is a block diagram illustrating a configuration instance of the address event detection unit according to a first configuration instance of this disclosure.

[0053] Figure 9 This is a schematic diagram illustrating the optical path of incident and reflected light on the object under test according to a first configuration example of this disclosure.

[0054] Figure 10 A is an illustrative view showing the scanning direction of the slit light relative to the object under test according to a first configuration example of this disclosure, and Figure 10 B is an illustrative view showing the detection principle of measurements that are correlated with the height of the object being measured.

[0055] Figure 11 This is an illustrative view of a first configuration example of this disclosure for deriving an arithmetic expression for calculating the height of an object under test.

[0056] Figure 12 This is a conceptual diagram illustrating the distribution of reflected light events generated according to a first configuration example of this disclosure.

[0057] Figure 13 This is a configuration block diagram illustrating a shape measurement system according to a second configuration example of the present disclosure.

[0058] Figure 14 This is a timing diagram illustrating the operation of the light source and light receiving unit of the shape measurement system according to a second configuration example of this disclosure.

[0059] Figure 15 This is a configuration block diagram illustrating a shape measurement system according to a third configuration example of the present disclosure.

[0060] Figure 16 This is a block diagram illustrating the configuration of each pixel column of the shape measurement system EVS according to a third configuration example of this disclosure.

[0061] Figure 17 This is a configuration block diagram illustrating a shape measurement system according to a fourth configuration example of the present disclosure.

[0062] Figure 18 A and B are optical path diagrams illustrating the function of the first and second polarizers of the shape measurement system according to a fourth configuration example of this disclosure.

[0063] Figure 19 This is a configuration diagram showing the pixel columns of the shape measurement system EVS according to a fourth configuration example of this disclosure.

[0064] Figure 20This is a block diagram illustrating the configuration of a shape measurement system according to a fifth configuration example of this disclosure.

[0065] Figure 21 This is an illustrative view showing the light projection state of each slit light in the light source section of the shape measurement system according to the fifth configuration example of this disclosure, which is divided into three wavelengths, R, G and B, as incident light.

[0066] Figure 22 This is an illustrative view showing the incident state of reflected light divided into three wavelengths, R, G and B, in the light receiving section of the shape measurement system according to the fifth configuration example of this disclosure. Detailed Implementation

[0067] In the following, the modes for implementing the technology of this disclosure (hereinafter referred to as "implementations") will be described in detail with reference to the accompanying drawings. The technology of this disclosure is not limited to the technology of each embodiment, and the various values, materials, etc., in each embodiment are examples. In the following description, the same elements or elements having the same function are given the same reference numerals, and repeated descriptions thereof are omitted. Note that the descriptions will be given in the following order.

[0068] 1. A shape measurement system according to a first embodiment of the present disclosure

[0069] 2. Shape measurement system according to the second embodiment of the present disclosure

[0070] 2-1. First configuration example... Single light source + multiple light receivers

[0071] 2-2. Second configuration example... Multiple light sources + a single light receiver (time-division control of light sources)

[0072] 2-3. Third configuration example... Multiple light sources + a single optical receiver (wavelength division multiplexing)

[0073] 2-4. Fourth configuration example... Multiple light sources + a single light receiver (polarization switching control)

[0074] 2-5. Fifth configuration example... Single light source + single light receiver (light dispersion through a prism)

[0075] 3. Configurations that can be adopted in this disclosure

[0076] <1. Shape Measurement System According to the First Embodiment>

[0077] Figure 1 This is a schematic diagram illustrating a shape measurement system according to a first embodiment of the present disclosure, and Figure 2 This is a block diagram illustrating a schematic configuration of a shape measurement system according to this disclosure. Figure 1In the accompanying figures, a three-dimensional Cartesian coordinate system is established, wherein the depth direction, scanning and movement direction, and height direction of the object under test are respectively defined as the mutually orthogonal X, Y, and Z directions. It should be noted that this disclosure uses a left-handed coordinate system. The origin is specifically designated at one of the four corners of the object under test.

[0078] [Configuration of the shape measurement system]

[0079] As an illustrative configuration, the shape measurement system 1 of this disclosure includes: a stage 2; a shape measuring device 10, which performs three-dimensional measurement on the measuring surface 100A of the object to be measured 100 mounted on the stage 2 in a standing state; a moving mechanism 3, which constitutes a scanning mechanism for intermittently moving the shape measuring device 10 in the Y direction; a control unit 4, which controls the moving mechanism 3; and a signal processing unit (hereinafter referred to as the "signal processing unit") 13, which performs signal processing in the shape measuring device 10. It should be noted that, as Figure 2 As shown, the shape measuring device 10 of this embodiment includes a light source 11 and a light receiving unit 12, and is housed in the head H.

[0080] In the shape measurement system 1 of this disclosure, a non-scanning (hereinafter referred to as "asynchronous") imaging method called an event-based vision sensor (EVS) is used. This will be described in detail later. Note that in this embodiment, the shapes are arranged from left to right. Figure 1 The multiple objects 100 shown are subjected to shape measurement operations sequentially and continuously. For this purpose, a moving mechanism 3 is provided. However, it goes without saying that the moving mechanism 3 is not needed when performing shape measurement on only a single object 100.

[0081] The stage 2 in this embodiment is a rectangular plate with uniform thickness in plan view, and its two long sides and horizontal sides are aligned with the X and Y directions, respectively. The stage 2 in this embodiment is placed on a base (not shown) or the like.

[0082] like Figure 1 and Figure 2As shown, under the control of the motion control unit 42, the motion mechanism 3 intermittently moves the head H of the shape measuring device 10 at high speed in the Y direction according to the measurement of the object to be measured 100, which will be described later. In this way, the measurement of the object to be measured 100 is performed sequentially. For example, a robot can be used as the motion mechanism 3 for this purpose. Alternatively, racks and pinions, ball screws, annular belts, wires, or any other suitable components can be used. It should be noted that although the motion mechanism 3 of this embodiment intermittently moves the head H in the Y direction, this disclosure is not particularly limited to this. That is, the stage 2 or base, rather than the head H, can also be moved. Furthermore, for example, as in the second embodiment, the motion mechanism of this disclosure can move the light source side within the head H, or only move the light source within the light source section.

[0083] The control unit 4 includes a system control unit 41 and a movement control unit 42. The system control unit 41 controls the movement control unit 42 and the shape measuring device 10 at predetermined timings. The movement control unit 42 controls the movement mechanism 3, which intermittently performs movement operations on the shape measuring device 10. The control unit 4 can move the head H from the starting point to the ending point of the object to be measured 100 at high speed in the Y direction.

[0084] The signal processing unit 13 acquires the three-dimensional shape of the object under test 100 by performing predetermined signal processing at high speed based on the "event data" obtained by the light receiving unit 12 of the shape measuring device 10. For example... Figure 2 As shown, the signal processing unit 13 of this embodiment includes a control signal transmission unit 131, an unwanted signal removal unit 132, a three-dimensional shape calculation unit (hereinafter referred to as "3D calculation unit") 133, and a memory 134. It should be noted that details of each of the above-described elements, including "event data," will be described later.

[0085] The object to be measured 100 is not particularly limited, but in the first embodiment of this disclosure, for example, its bottom surface is rectangular and unevenness is formed on its upper surface (i.e., the measuring surface). Even in cases where the unevenness varies greatly, the shape measuring device 10 of this disclosure can detect and measure the shape at high speed using EVS and with high accuracy using arithmetic expressions described later.

[0086] [Function and Effects of the First Embodiment]

[0087] The shape measuring device 10 of the shape measuring system 1 of this disclosure measures the shape of a test object 100 in three dimensions, including its length (Y), depth (X), and height (Z). As a means of shape measurement according to this disclosure, a slit light (hereinafter sometimes referred to as "measuring light") having a broadband shape or extending in a conical shape and fan-shaped structure is generated by the light source unit 11 in the head H. Note that the shape of the slit light is not limited to the shapes described above. For example, the shape can be a specific shape corresponding to the shape of the test object or the measuring surface and effective for shape measurement.

[0088] The shape measuring device 10 performs shape measurement sequentially, one pixel column at a time, by projecting slit light along the direction of the vertical cross-section (XZ plane) of the object to be measured 100. Furthermore, while performing the slit light projection operation along the XZ direction, Figure 3 The scanning mechanism 113 in the light source unit 11 shown operates to perform a scanning operation from left to right in the Y (lateral) direction. That is, a series of scanning operations are performed from the starting end to the ending end in the Y (lateral) direction. In this way, slit light is projected and scanned in the Y direction, and thus three-dimensional shape measurement is performed.

[0089] In the shape measurement system 1 according to this disclosure, after the measurement light traveling from the light source in the light source unit (not shown) toward the object under test 100 is scattered and reflected at the same measurement point (measurement position) of the object under test 100, at least two types of reflected light (conventional reflected light, which will be described later) traveling on different shortest optical paths can be used as the measurement light traveling toward the reflection (or return path) side of the light receiving unit (not shown). Note that a specific shape measurement method using the reflected light and its qualitative principle will be described in detail in the second embodiment described later.

[0090] The shape measurement operation performed on each object 100 by the laser projected by the shape measuring device 10 has been described above. In this embodiment, this series of shape measurement operations is performed sequentially on each object 100. Therefore, the movement control unit 42 controls the intermittent operation of the movement mechanism 3 at regular intervals. In this way, when the measurement operation of one object is completed, the head H of the shape measuring device 10 moves one step in the Y direction to the next object. By repeating such intermittent operation on the head H each time, the three-dimensional (hereinafter referred to as "3D") shape of the measurement surface 100A of each object 100 can be continuously acquired by the EVS.

[0091] As described above, in this embodiment, an asynchronous imaging device called EVS is used, and unlike conventional sensors, the use of EVS enables shape measurement to be performed at high speed in terms of time.

[0092] <2. Shape Measuring Device of the Shape Measuring System of the Second Embodiment>

[0093] (2-1. First Configuration Example)

[0094] Next, the shape measuring device included in the shape measuring system according to the second embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0095] Figure 3 A first aspect of a second embodiment according to this disclosure (hereinafter referred to as the "first configuration example") is shown. Specifically, Figure 3 The configuration of the shape measuring device 10A according to a first configuration example is shown, particularly the configuration of the light source unit 11, the light receiving unit 12, and the signal processing unit 13 included in the shape measuring device 10A. It should be noted that, compared with... Figure 1 and Figure 2 The same parts in the figures are given the same reference numerals, and their repeated descriptions are avoided.

[0096] The shape measuring device 10A disclosed herein may have the same configuration as or a different configuration than that used in the shape measuring system 1 of the first embodiment. The shape measuring device 10A of the first configuration example includes a single light source unit 11 and a plurality of light receiving units 12.

[0097] As described above, in the shape measuring device 10A according to this configuration example, in addition to a single light source unit 11 and two light receiving units 12 including a first light receiving unit 12A and a second light receiving unit 12B, a signal processing unit 13 is also housed in the head H. It should be noted that in the head H of this disclosure, only the light source unit 11 and the light receiving units 12 can be housed, and the signal processing unit 13 can be installed separately and can exchange data using wireless communication, infrared communication, etc.

[0098] Preferably, the two light receiving units 12, namely the first light receiving unit 12A and the second light receiving unit 12B, are separated as far as possible. For example, the shape measuring device 10A in the first configuration example can be installed at a position opposite to each other in the lateral (Y) direction relative to the light source unit 11, but it is not necessary to arrange them symmetrically with respect to the light source unit 11.

[0099] [Configuration of the shape measuring device]

[0100] In this configuration example, the light source unit 11 (hereinafter referred to as "light source unit 11A") is a single light source unit as described above, and specifically includes the light source 111A, the waveform control lens 112, and the scanning mechanism 113, as follows. Figure 3 As shown. It should be noted that in the following description of this configuration example, "A" will be omitted from the components of the light source section 11A, especially for the light source 111A, in order to simplify the description.

[0101] As the light source 111, a semiconductor laser (hereinafter referred to as "semiconductor laser 111") can be used. The semiconductor laser 111 according to this embodiment can, for example, be a laser with a continuously oscillating blue wavelength (λb). In the first configuration example, this blue light is used as the measurement light for measuring the object under test 100. Note that the laser used in the light source section of this disclosure is not particularly limited to this blue light. The light source of this configuration example preferably emits high-brightness light and has a certain degree of directionality. Furthermore, the illumination light used does not need to be as coherent as a laser, but is preferably illumination light with small chromatic aberration and other aberrations. It should be noted that when a laser is used as the light source, an edge-emitting laser (EEL) or a vertical-cavity surface-emitting laser (VCSL) can be used.

[0102] As the waveform control lens 112, a waveform shaping lens (hereinafter referred to as "waveform shaping lens") is used. This waveform shaping lens is an optical element used to process the emitted laser waveform into a slit shape. As the waveform shaping lens in this configuration example, a cylindrical lens (hereinafter referred to as "cylindrical lens 112") is used. Specifically, for example, the waveform shape of the blue laser light oscillating and emitted from the semiconductor laser 111 in a beam shape is shaped (processed) into a thin and wide rectangular (strip-shaped) light along the travel direction or a thin fan-shaped light along the travel direction (hereinafter, these are referred to as "line slit light" or simply "slit light"). The line slit light of this configuration example is emitted such that... Figure 1 As shown, a slit light is used to simultaneously illuminate the entire column of pixels (columns) with a narrow width and a long length along the depth (X) direction of the object under test 100.

[0103] The scanning mechanism 113 performs scanning by emitting a laser beam in the Y (ROW) direction over time, the waveform of which has been shaped into a slit shape by the cylindrical lens 112. By emitting lasers sequentially in the Y direction, the scanning mechanism 113 can measure the shape of the entire surface of the measurement surface 100A of the object under test 100 in three dimensions.

[0104] Note that in the configuration examples of this disclosure, a type is employed in which the shape measuring device 10A side is scanned relative to the stationary object 100 to measure the three-dimensional shape of the object 100. In this disclosure, a type can be employed in which the shape measuring device 10A side is stationary, and the object 100 side is moved and scanned by a suitable transport device to perform the measurement. However, in the latter case, when a moving object appears, it is captured and a signal is output due to the characteristics of the imaging device 122, which will be described later. Therefore, considerations such as reducing illumination light and measuring shape in dark environments, using the infrared region as the laser source wavelength, and mounting an optical filter with the same wavelength band in front of the imaging element of the imaging device 122 are necessary.

[0105] like Figure 3 As shown, the light receiving unit 12 in this configuration example includes a light receiving lens 121, an imaging device 122, an event publishing unit 123, and a transmitting unit 124. Furthermore, in the first configuration example, for ease of understanding and description, the front-end portion of the light receiving unit 12 will be described as a "light receiving function unit," and for ease of description, the rear-end portion of the light receiving unit 12 will be described as a "detection function unit."

[0106] In this configuration example, specifically, the first light receiving unit 12A includes a first light receiving lens 121A, a first imaging device 122A, a first event publishing unit 123A, and a first transmitting unit 124A. Similarly, specifically, the second light receiving unit 12B includes a second light receiving lens 121B, a second imaging device 122B, a second event publishing unit 123B, and a second transmitting unit 124B. It should be noted that in the following configuration example, for the sake of simplicity, only three digits are given as reference numerals for the above components, and "A" and "B" are omitted.

[0107] The light-receiving function unit, serving as a pre-stage component, receives reflected light (scattered light), specifically, the slit light projected from the light source unit 11A and then reflected by the measurement surface 100A. In this embodiment, the light-receiving function unit may include a light-receiving lens 121 and an imaging unit 21 (described later). The imaging unit 21 includes optical elements comprising an imaging device 122 and various circuits. Using this configuration, the light-receiving function unit acquires brightness (brightness variation) data about the shape of the object 100 being measured, obtained by measuring the object 100 in pixel columns. Then, information signals such as the external shape and positional information associated with the external shape (i.e., signals for detecting event data, described later) are output to the detection function unit in the subsequent stage. Note that the imaging unit 21 will be described in detail later.

[0108] In the components of the light-receiving functional section, the light-receiving lens 121 forms an image of the incident slit light on the imaging device 122. The light-receiving lens of this disclosure forms an image of reflected light only on the imaging device 122.

[0109] Imaging device 122 uses the aforementioned event-based vision sensor (EVS) as a sensor for a system different from conventional systems. The EVS includes an asynchronous imaging device, wherein pixels that perform photoelectric conversion on incident light reflected from the object under test 100 are arranged in a two-dimensional matrix. In this EVS, multiple pixel circuits are arranged in a two-dimensional grid pattern. A group of pixel circuits aligned in the depth (X) direction is called a "row," and a group of pixel circuits aligned in the horizontal (Y) direction orthogonal to the row is called a "column." In each EVS, based on image information of each pixel column (column), a photoelectric conversion signal is captured into each pixel based on the received reflected light beams β1 and β2. The input data is output to event publishing unit 123.

[0110] On the other hand, the detection function unit performs signal processing. In this way, the signal from the incident light is treated as an event. Since the EVS only outputs pixel information indicating that a brightness change has occurred in each pixel, it can output a stable signal without being affected by the color or reflectivity of the object under test or ambient light. The detection function unit may include an event issuing unit 123 and a sending unit 124.

[0111] Event release unit 123 is part of the detection function unit. Event release unit 123 receives a synchronization signal from control signal transmission unit 131 and outputs an event signal (described later) for 3D reconstruction of the surface shape of the object under test 100 obtained from EVS 122 to transmission unit 124 in sync with the synchronization signal.

[0112] That is, when an event is detected, the event publishing unit 123 of this embodiment detects the location of the event based on the synchronization signal input at time t. (See below for further details.) Figures 5 to 8 The location detection is described below. Furthermore, for each received pixel address, the event publishing unit 123 detects a brightness change as an "address event" in real time. When an address event is detected, the event publishing unit 123 performs a brightness comparison with the immediately preceding address event. Brightness changes exceeding a predetermined threshold are detected and taken as an "event," and data including location information (coordinate data) indicating the coordinate position of the event (referred to as "event data") is output to the transmitting unit 124. In addition to location information, the event data may also include time information indicating the relative time of the event's occurrence. Furthermore, this may include grayscale information indicating the signal level.

[0113] The sending unit 124 outputs the event data for three-dimensional reconstruction output from the event publishing unit 123 to the unwanted signal removal unit 132 on the signal processing unit 13 side (described later).

[0114] [Signal processing unit configuration]

[0115] The signal processing unit 13 of this embodiment detects and stores the three-dimensional data of the object under test 100 at high speed based on the data obtained from the light receiving unit 12. As described above, the signal processing unit 13 includes a control signal transmitting unit 131, an unwanted signal removal unit 132, a 3D calculation unit 133, a memory 134, etc.

[0116] like Figure 4 As shown, at the start of the operation for measuring the shape of the object under test 100 (time t0), the control signal transmitting unit 131 outputs control signals to these components to start the light source 111 and the scanning mechanism 113. That is, in sync with the laser oscillation operation at the start of shape measurement, scanning of the object under test 100 in the transverse (Y) direction also begins. Furthermore, the control signal transmitting unit 131 outputs synchronization signals to the event publishing unit 123 of each of the light receiving units 12A and 12B to drive the event publishing unit 123 in sync with the laser oscillation operation of the light source 111 and the scanning operation of the scanning mechanism 113. As a result, while a brightness signal is input via the EVS 122, the event publishing unit 123 can associate the synchronization signal with event data. In this way, shape measurement data for all pixels of the entire surface of the object under test 100 is generated.

[0117] It should be noted that, in cases such as Figure 1 In the system shown, where a large number of objects to be measured are arranged, shape measurements of multiple objects to be measured can be performed one after another through intermittent operation of the moving mechanism 3 of the shape measuring device 10A in the Y direction (this is referred to as "multi-object measurement"). On the other hand, in the case of a shape measurement system for a single object without a moving mechanism, shape measurement operations for a single object to be measured can be repeatedly and continuously performed in time by performing similar control regarding a frequency sweep operation process (this is referred to as "single-object measurement"). As a result, in single-object measurement, time changes of the object to be measured 100 can be detected at minute time intervals. In configuration examples following the first configuration example, the "single-object measurement" type is used, which is convenient, for example, when the shape changes constantly. It should be noted that in this disclosure, "multi-object measurement" can be used in configuration examples following the first configuration example.

[0118] The unwanted signal removal unit 132 removes unwanted signals associated with multipath reflected light (sometimes referred to as "secondary reflected light"), which causes measurement errors when laser light from the light source 111 is incident on the measurement surface 100A. Multipath reflected light is light incident from paths not intended for measurement and is mainly generated due to multiple reflections occurring on various objects in the external world. In this configuration example, the unwanted signal removal unit 132 removes unwanted signals generated by secondary reflected light incident at an angle of incidence (reference angle) different from the particularly desired scattered light (which becomes "conventional reflected light" to be described later) of the slit light incident from the light source 11A onto the imaging device 122.

[0119] Specifically, the coordinates (X, Y, Z) of each pixel corresponding to a designated point on the surface of the object under test 100 (i.e., the incident point of the slit light at a specific time t) are uniquely determined. That is, in the light receiving unit 12, the incident angle of the reflected light from the light source 111 toward the object under test 100 is a specific value (normal incident angle). If the height is the same as the immediately preceding point, the incident angle of the reflected light (sometimes called "normal reflected light") (i.e., the light reflected by the object under test 100 incident at a normal incident angle (sometimes called "normal incident light")) entering the imaging device 122 is the same. Therefore, when the incident angle of the normal reflected light on the light receiving unit 12 is different, there is a difference in unevenness and height compared to the measurement surface at the immediately preceding point. That is, this indicates that the height of the object under test 100 has changed.

[0120] Secondary reflected light sometimes mistakenly strikes the light receiving unit 12 at an angle of incidence different from the conventional angle of incidence. As a result, the shape of the point may be misdetected. In view of this, the unwanted signal removal unit 132 removes electrical signals (hereinafter referred to as "unwanted signals") other than the electrical signals generated from the received light intensity or received light quantity obtained when the light is incident at the expected conventional angle of incidence (hereinafter referred to as "conventional electrical signals"), that is, electrical signals that are different from the unique photocurrent value or photovoltaic value.

[0121] The 3D calculation unit 133, based on the conventional electrical signal obtained after the unwanted signal generating unwanted noise is removed by the unwanted signal removal unit 132, uses an arithmetic expression described later to generate a two-dimensional shape (referred to as "two-dimensional data") for each pixel column by cutting the object under test 100 into a line shape with each slit light. Then, the scanning mechanism 113 scans the frequency and moves the slit light in the Y direction, thereby generating a three-dimensional shape of the object under test 100 (hereinafter referred to as "3D shape") by combining multiple two-dimensional data of the line shape.

[0122] The memory 134 stores shape information about a three-dimensional shape, especially height information (or thickness information), which is event data of each pixel of the object 100 obtained by processing data about the three-dimensional shape of the measuring surface 100A of the object 100, which is captured sequentially by the shape measuring device 10A, through necessary circuitry.

[0123] [Imaging Unit Configuration Example]

[0124] Next, we will refer to Figures 5 to 8 The description includes the imaging unit 21 of the imaging apparatus 122 of this disclosure.

[0125] The following describes in detail a configuration example of the imaging unit 21 of the imaging apparatus 122, which includes the light receiving unit 12 according to the first configuration example. Figure 5 This is a block diagram showing an example of the configuration of the imaging unit 21.

[0126] like Figure 5 As shown, the imaging unit 21 according to this configuration example uses an asynchronous imaging device called EVS, and includes a pixel array unit 211, a driving unit 212, an arbitrator unit 213, a column processing unit 214, and a signal processing unit 215.

[0127] 1) Pixel array section

[0128] In the imaging unit 21 with the above configuration, a plurality of pixels 210 are arranged in a two-dimensional matrix (array) in the pixel array unit 211. The vertical signal line VSL, which will be described later, is routed to this matrix pixel array for each pixel column (column).

[0129] Each of the plurality of pixel units 210 generates an analog signal of voltage corresponding to the photocurrent as a pixel signal. Furthermore, each of the plurality of pixels 210 detects the presence or absence of an address event based on whether the change in photocurrent exceeds a predetermined threshold. Then, in the event of an address event, the pixel 210 outputs a request to the arbitrator unit 213.

[0130] 2) Drive unit

[0131] The driving unit 212 drives each of the plurality of pixels 210 to output the pixel signal generated in the pixel 210 to the column processing unit 214.

[0132] 3) Arbitration Department

[0133] Arbitrator unit 213 arbitrates requests from each of the multiple pixels 210 and sends a response based on the arbitration result to pixel 210. Pixel 210 that has received a response from arbitrator unit 213 provides event data (detection signal of address event) indicating the detection result to driver unit 212 and signal processing unit 215. Event data can be read from multiple rows when reading event data from pixel 210.

[0134] 4) Column processing department

[0135] The column processing unit 214 includes, for example, an analog-to-digital converter, and performs processing for each pixel column of the pixel array unit 211, such as converting the analog pixel signal output from the pixel 210 of the column into a digital signal. Then, the column processing unit 214 provides the digital signal obtained after analog-to-digital conversion to the signal processing unit 215.

[0136] 5) Signal Processing Unit

[0137] The signal processing unit 215 performs predetermined signal processing on the digital signal provided by the slave processing unit 214, such as correlated double sampling (CDS) processing or image recognition processing. Then, the signal processing unit 215 outputs data indicating the processing result and event data provided by the arbitrator unit 213 via the signal line 216.

[0138] [Configuration example of pixel array section]

[0139] Figure 6 This is a block diagram showing a configuration example of the pixel array section 211.

[0140] In the pixel array section 211 in which a plurality of pixels 210 are arranged in a matrix in two dimensions, each of the plurality of pixels 210 includes a photoelectric conversion section 51, a pixel signal generation section 52 and an address event detection section 53.

[0141] 1) Photoelectric conversion unit

[0142] In the pixel 210 with the above configuration, the photoelectric conversion unit 51 photoelectrically converts the incident light to generate a photocurrent. Then, under the control of the driving unit 212, the photoelectric conversion unit 51 provides the photocurrent generated by the photoelectric conversion to the pixel signal generation unit 52 or the address event detection unit 53 (see...). Figure 5 ).

[0143] 2) Pixel signal generation unit

[0144] The pixel signal generation unit 52 generates a voltage signal corresponding to the photocurrent supplied from the photoelectric conversion unit 51 as a pixel signal SIG, and provides the generated pixel signal SIG to the column processing unit 214 via the vertical signal line VSL (see [link]). Figure 5 ).

[0145] 3) Address Event Detection Department

[0146] The address event detection unit 53 detects the presence or absence of an address event (hereinafter sometimes simply referred to as an "event") based on whether the change in photocurrent from the photoelectric conversion unit 51 exceeds a predetermined threshold. For example, address events include a turn-on event indicating that the change in photocurrent exceeds an upper threshold and a turn-off event indicating that the change is below a lower threshold. Furthermore, the address event detection signal includes, for example, a bit indicating the detection result of a turn-on event and a bit indicating the detection result of a turn-off event. Note that the address event detection unit 53 can be configured to detect only turn-on events.

[0147] When an address event occurs, the address event detection unit 53 provides a request to send a detection signal for the address event to the arbitrator unit 213 (see [link]). Figure 5 Then, when a response to the request is received from the arbitrator unit 213, the address event detection unit 53 provides the address event detection signal (event data) to the driver unit 212 and the signal processing unit 215.

[0148] [Circuit configuration example for a pixel]

[0149] Figure 7 This is a circuit diagram showing an example of the circuit configuration of pixel 210. As described above, each of the plurality of pixels 210 includes a photoelectric conversion unit 51, a pixel signal generation unit 52, and an address event detection unit 53.

[0150] 1) Photoelectric conversion unit

[0151] In the pixel 210 with the above configuration, the photoelectric conversion unit 51 includes a photoelectric conversion element (light receiving element) 511, a transmission transistor 512, and an overcurrent gate (OFG) transistor 513. For example, N-type metal-oxide-semiconductor (MOS) transistors can be used as the transmission transistor 512 and the OFG transistor 513. The transmission transistor 512 and the OFG transistor 513 are connected in series with each other.

[0152] 1-1) Photoelectric converter

[0153] The photoelectric conversion element 511 is connected between the common connection node N1 between the transmission transistor 512 and the OFG transistor 513 and ground, and photoelectrically converts the incident light to generate a charge corresponding to the amount of incident light.

[0154] 1-2) Transmission transistor

[0155] Transmit signal TRG from Figure 5The driving unit 212 shown provides the gate electrode to the transmission transistor 512. In response to the transmission signal TRG, the transmission transistor 512 provides the charge obtained by the photoelectric conversion of the photoelectric conversion element 511 to the pixel signal generation unit 52.

[0156] 1-3) OFG transistor

[0157] A control signal OFG is provided from the driving unit 212 to the gate electrode of the OFG transistor 513. In response to the control signal OFG, the OFG transistor 513 provides an electrical signal generated by the photoelectric conversion element 511 to the address event detection unit 53. The electrical signal provided to the address event detection unit 53 is a photocurrent composed of charge.

[0158] 2) Pixel signal generation unit

[0159] The pixel signal generation unit 52 includes a reset transistor 521, an amplification transistor 522, a selection transistor 523, and a floating diffusion layer 524. For example, an N-type MOS transistor can be used as the reset transistor 521, the amplification transistor 522, and the selection transistor 523.

[0160] The charge obtained by photoelectric conversion through photoelectric conversion element 511 is provided from photoelectric conversion unit 51 to pixel signal generation unit 52 via transfer transistor 512. The charge provided from photoelectric conversion unit 51 accumulates in floating diffusion layer 524. Floating diffusion layer 524 generates a voltage signal having a voltage value corresponding to the amount of accumulated charge. That is, floating diffusion layer 524 converts charge into voltage.

[0161] 2-1) Reset transistor

[0162] Reset transistor 521 is connected to the power supply voltage V. DD The power supply line is between the power supply line and the floating diffusion layer 524. A reset signal RST is provided from the driving section 212 to the gate electrode of the reset transistor 521. In response to the reset signal RST, the reset transistor 521 initializes (resets) the charge of the floating diffusion layer 524.

[0163] 2-2) Amplifying transistor

[0164] Amplifying transistor 522 and selecting transistor 523 are connected at power supply voltage V DD The power supply line is connected in series with the vertical signal line VSL. The amplifying transistor 522 amplifies the voltage signal obtained through charge-to-voltage conversion by the floating diffusion layer 524.

[0165] 2-3) Selecting a transistor

[0166] The selection signal SEL is provided from the driving unit 212 to the gate electrode of the selection transistor 523. In response to the selection signal SEL, the selection transistor 523 outputs the voltage signal amplified by the amplifying transistor 522 as a pixel signal SIG through the vertical signal line VSL to the column processing unit 214 (see [link to relevant documentation]). Figure 5 ).

[0167] In the imaging unit 211, which includes the pixel array unit 211, the pixels 210 having the above configuration are arranged in two dimensions. When the light receiving control unit (not shown) indicates to start detecting address events, the driving unit 212 provides the control signal OFG to the OFG transistor 513 of the photoelectric conversion unit 51, thereby driving the OFG transistor 513 to provide photocurrent to the address event detection unit 53.

[0168] 2-4) Floating diffusion layer

[0169] Then, when an event is detected in a pixel 210, the driving unit 212 disconnects the OFG transistor 513 of pixel 210 and stops supplying photocurrent to the address event detection unit 53. Next, the driving unit 212 drives the transmission transistor 512 by providing the transmission signal TRG to the transmission transistor 512, thereby causing the transmission transistor 512 to transfer the charge obtained by photoelectric conversion by the photoelectric conversion element 511 to the floating diffusion layer 524.

[0170] In this way, the imaging unit 211, which includes a pixel array 211 in which pixels 210 having the above configuration are arranged in two dimensions, outputs only the pixel signals of the pixels 210 in which the occurrence of an event is detected to the column processing unit 214. As a result, compared with the case where pixel signals of all pixels are output regardless of whether an event has occurred, the power consumption of the imaging unit 21 can be reduced, and ultimately the power consumption of the imaging device 122 and the amount of image processing are reduced.

[0171] Note that the pixel configuration shown above is an example and is not limited to this configuration example. For example, a pixel configuration that does not include the pixel signal generation unit 52 can also be used. In the case of using this pixel configuration, it is only necessary to omit the OFG transistor 513 in the photoelectric conversion unit 51 and provide the function of the OFG transistor 513 to the transmission transistor 512.

[0172] 3) Address Event Detection Department

[0173] Figure 8 This is a block diagram showing a configuration example of the address event detection unit 53. For example... Figure 8 As shown, the address event detection unit 53 according to this configuration example includes a current-to-voltage conversion unit 531, a buffer 532, a subtractor 533, a quantizer 534, and a transmission unit 535.

[0174] 3-1) Current-to-voltage conversion unit and buffer

[0175] The current-to-voltage converter 531 converts the photocurrent supplied from the photoelectric converter 51 of the pixel 210 into a voltage signal as its logarithm. The current-to-voltage converter 531 provides the voltage signal obtained by the conversion to the buffer 532. The buffer 532 buffers the voltage signal supplied from the current-to-voltage converter 531 and provides the voltage signal to the subtractor 533.

[0176] 3-2) Subtractors and quantizers

[0177] A row drive signal is provided from the drive unit 212 to the subtractor 533. The subtractor 533 reduces the level of the voltage signal provided from the buffer 532 according to the row drive signal. Then, the subtractor 533 provides the reduced voltage signal to the quantizer 534. The quantizer 534 quantizes the voltage signal provided from the subtractor 533 into a digital signal and outputs the digital signal as an address event detection signal (event data) to the transmission unit 535.

[0178] 3-3) Teleportation Department

[0179] For example, the transmission unit 535 transmits the address event detection signal (event data) provided by the quantizer 534 to the arbitrator unit 213. When an event is detected, the transmission unit 535 provides the arbitrator unit 213 with a request to send the address event detection signal. Then, when a response to the request is received from the arbitrator unit 213, the transmission unit 535 provides the address event detection signal to the driver unit 212 and the signal processing unit 215.

[0180] Shape measurement methods (measurement principles) for measuring the shape of an object under test.

[0181] Next, we will refer to Figure 9 and Figure 10 The shape measurement principle in the shape measuring device 10A of the shape measuring system according to the second embodiment of the present disclosure is described.

[0182] In the first configuration example of this disclosure, as described above, the three-dimensional shape of the object under test 100 (measuring surface 100A) is detected by using a single light source 11A and two light receiving units 12 (i.e., light receiving units 12A and 12B).

[0183] The positional relationship between the light source unit 11A and the light receiving unit 12, which includes light receiving units 12A and 12B, is not particularly limited, but in this configuration example, as... Figure 9As shown, light receiving units 12A and 12B are arranged on both sides of the light source unit 11A. The light receiving units 12A and 12B do not need to be arranged symmetrically with respect to the light source unit 11A, and are preferably separated from each other as much as possible. Alternatively, the light source unit 11A and the light receiving units 12B may be arranged along the same YZ plane, or they may not be arranged on the same YZ plane.

[0184] Blue light from the semiconductor laser (LD) of the light source 111, which is the light source unit 11A, passes through Figure 3 The cylindrical lens 112 shown is waveform-processed to become a line slit light parallel to the XZ plane, and is projected and emitted onto the measurement surface 100A of the object under test 100.

[0185] When the line slit light is incident on the measurement surface 100A, the line slit light is scattered due to the unevenness of the measurement surface 100A, and the scattered light passes through the light receiving lenses of the light receiving units 12A and 12B and enters EVS1 and EVS2, which are imaging devices 122A and 122B.

[0186] There is a possibility that scattered light generated by scattering on the measuring surface 100A is incident as reflected light onto EVS1 and EVS2, which are imaging devices 122A and 122B. Therefore, in this disclosure, during the measurement on the measuring surface 100A, the reflected light beams, after being scattered and reflected at various locations, are guided into the light receiving units 12A and 12B. In particular, the two measuring beams that enter the light receiving units 12A and 12B at different locations by traveling different shortest optical paths become conventional reflected light. The data obtained from the conventional reflected light is used for shape measurement in this disclosure.

[0187] Even for the object under test 100 in this configuration example, there is a possibility that secondary waves (secondary reflected light) may enter EVS1 and EVS2 (hereinafter sometimes referred to as "EVS1 and 2"), which are imaging devices 122, thus causing measurement (distance measurement) errors. Therefore, the distance to the measurement surface 100A in EVS1 and EVS2, etc., is calculated from the data obtained by measurements through EVS1 and EVS2 at each time t using a predetermined arithmetic expression described later, wherein data with shapes consistent with each other obtained by EVS1 and EVS2 is used as data obtained from conventional reflected light, and the cross-sectional shape of the object under test 100 is calculated from conventional reflected light using the following arithmetic expression to obtain the three-dimensional shape. This will refer to Figure 10 and Figure 11 Detailed description.

[0188] Note that the arithmetic expressions used here are as follows, and in particular, the shape at each point (X, Y, Z) of the measuring surface 100A can be calculated from these arithmetic expressions.

[0189] X = the X-coordinate of a point in the depth direction…(1)

[0190] Y = (scanning speed of the scanning mechanism) * (operation time of the scanning mechanism) - (distance measurement error Δy in the Y direction) ... (2)

[0191] Z = (distance measurement error Δy in the Y direction) / (tanθ) ... (3)

[0192] Where θ is the tilt angle of the light source relative to the vertical line.

[0193] Here, the derivation of expression (3) will be described with reference to the attached figure.

[0194] Figure 11 The optical path of the laser emitted from light source 122, which is an LD oscillator of light source 111, is shown. Because the laser is coherent, portions of the same specific phase (wavefront) along the laser's optical path are represented by thick black circles and slanted dashed lines for ease of understanding. Additionally, the horizontal line is represented by dashed lines to clearly indicate the height from stage 2. It should be noted that the measurement light used in this configuration example of the present disclosure does not necessarily need to use and detect, for example, phase changes, and can therefore be incoherent light.

[0195] exist Figure 11 In this context, assuming the coordinates of the bottom of a specific slit light point C on the measuring surface 100A directly below it are A = (X0, Ya, Z0), the coordinates of the bottom B facing the stage 2 are B = (X0, Yb, Z0), and the coordinates of point C on the surface at a height H measured from the stage 2 are C = (X0, Ya, Za), the following expression is established in triangle ABC for the distance measurement error Δy, which is the deviation of the conventional reflected light from points B and C in the lateral (Y) direction:

[0196] tanθ=Δy / H…(4)

[0197] (Where H is the thickness of the object to be measured 100). The height to be obtained is H = Δy / tanθ, that is, expression (3) is derived from expression (4). Therefore, the three-dimensional coordinates (X0, Ya, Za) of point C, which includes data in the thickness direction of the measuring surface 100A, are obtained through expressions (1) to (3). In addition, the X coordinate of point C is X = 0, but it is not particularly limited to this coordinate position. Any position coordinate in the X direction can be applied to the object to be measured 100 on the stage 2.

[0198] It should be noted that, as a method for obtaining three-dimensional data in this configuration example, a configuration that generates a three-dimensional shape by simultaneously identifying and extracting conventional reflected light from the phase difference or the difference between polarization planes can be used instead of the method described above. A configuration example using polarization planes will be described in detail later.

[0199] Therefore, the plane wave (or spherical wave) reaching the measurement surface 100A of the object under test 100 differs in its transmission time t from the plane wave to the light receiver (and also differs in phase difference, etc.) depending on the height position of the measurement surface 100A. As a result, the distance measurement error Δy included in the above arithmetic expressions (2) and (3) is generated. Therefore, the height H of the object under test can be calculated based on the time t and the distance measurement error Δy. It should be noted that although details are omitted in this disclosure, time differences can also be generated in the intensity E of the electric field reaching the imaging device 122, the amount of accumulated charge, etc. For example, the height of the object under test 100 can be measured by using the difference in brightness of each pixel or the difference in the amount of accumulated charge.

[0200] [The purpose and effect of this configuration example]

[0201] Therefore, according to this configuration example, in EVS1 and EVS2, which are two imaging devices 122A and 122B, by receiving conventional reflected light (scattered light), detection signals with the same shape (height H) are output from both EVS1 and EVS2, not only from points with small shape changes but also from points with large shape (unevenness). Figure 12 This is a schematic diagram showing the output distribution of event data for each pixel at a specific time t1. Figure 12 In this process, it can be determined that the left and right halves of the event data output state are completely different.

[0202] However, given a single EVS (and assuming a single light source), it is not possible to determine which event data output is generated by a conventional signal based on conventional reflected light.

[0203] In this configuration example, two imaging devices 122 are used. At a specific point at a specific time t, in the case of capturing conventional reflected light, the height of the convex portion (or the depth of the concave portion) at the point obtained from both EVS1 and EVS2 should be uniquely determined, regardless of which of EVS1 and EVS2 captures the reflected light. That is, the height H at the same point cannot physically have multiple values. The event data at the same point obtained from both EVS1 and EVS2 should be identical, and the reflected light that gives a unique input signal value between EVS1 and EVS2 is conventional reflected light.

[0204] Therefore, in this embodiment, as described above, calculations based on data obtained from conventional reflected light are performed using the aforementioned arithmetic expression. Thus, accurate shape measurements can be performed even at points with large differences in unevenness. Furthermore, since EVS is used as imaging devices 122A and 122B, three-dimensional images can be captured at high speed.

[0205] As described above, according to this configuration example, the measurement light traveling on the shortest optical path is used as the measurement light traveling from the light source 111 in the light source unit 11A toward the object under test 100. After the measurement light is scattered and reflected at a specific position on the measurement surface 100A, which is the measurement point of the object under test 100, two beams of measurement light (conventional reflected light) that are reflected and scattered at the same point (same position) and travel on different shortest optical paths can be used as measurement light traveling toward the light receiving unit 12. Therefore, even if multipath reflected light (i.e., secondary reflected light) is mixed in the reflected light and the secondary reflected light is incident on the light receiving unit 12, the shape of the measurement surface of the object under test 100 can be accurately measured by using two conventional reflected beams having the above characteristics. In particular, even if the shape has large irregularities, calculations can be performed with high precision using the above arithmetic expressions (1) to (3).

[0206] (2-2. Second Configuration Example)

[0207] Next, we will refer to Figure 13 and Figure 14 This describes a shape measuring apparatus 10B, a second aspect (hereinafter referred to as "second configuration example") of a shape measuring system according to a second embodiment of the present disclosure. Furthermore, the same reference numerals are used to denote the same parts as in the first configuration example, and repeated descriptions are omitted.

[0208] The difference between this configuration example and the first configuration example described above is that two light source units 11 are used, specifically a first light source unit 11B and a second light source unit 11C, and a single light receiving unit 12 (hereinafter referred to as light receiving unit 12C). Preferably, the two light source units, specifically the first light source unit 11B and the second light source unit 11C, are installed separately from each other. For example, the two light source units (specifically, the first light source unit 11B and the second light source unit 11C) can be installed at positions opposite each other in the lateral (Y) direction relative to the light receiving unit 12. The two light source units, specifically, the first light source unit 11B and the second light source unit 11C, do not need to be symmetrically arranged with respect to the light receiving unit 12. Furthermore, in this configuration example, the control of the control signal transmitting unit 131 of the signal processing unit 13 is also different.

[0209] The first light source unit 11B can use a first semiconductor laser (LD1) 111B that continuously oscillates blue laser light with a blue wavelength (λb) as its light source. The second light source unit 11C can also use a second semiconductor laser (LD2) 111C that has the same wavelength (λb) as the first semiconductor laser (LD1) 111B as its light source. As will be described in detail later, the first semiconductor laser (LD1) 111B can perform oscillation by time-division driving with the second semiconductor laser (LD2) 111C according to the control signal from the control signal transmission unit 131.

[0210] In the first light source unit 11B and the second light source unit 11C, the cylindrical lens 112 and the scanning mechanism 113 may also have the same configuration as the configuration in the first configuration example.

[0211] Furthermore, in each of the light source units 11B and 11C in this configuration example, the object to be measured 100 is scanned sequentially in the horizontal (Y) direction. However, in this configuration example, within half of the two divided time intervals, the slit light is sequentially projected onto the entire width of each pixel column (column) in the depth (X) direction. Specifically, as... Figure 14 As shown, when slit light is projected onto each pixel column (column) at time intervals Δt, under the control of the control signal transmitting unit 131, a blue laser with a specific wavelength (λb) is emitted from the first light source unit 11B for Δt / 2 seconds. Afterwards, blue lasers with the same wavelength (λb) are continuously emitted from the second light source unit 11C for Δt / 2 seconds. These blue laser beams are projected onto the object under test 100 from light sources 111B and 111C arranged at different positions.

[0212] Simultaneously, a single light receiver 12C is provided, and the light receiver 12C uses an asynchronous type as the imaging device 122, as in the first configuration example. That is, an event-based vision sensor (EVS) is used, which has a configuration in which pixels that photoelectrically convert incident light reflected by the object under test 100 are arranged in a matrix in two dimensions. In this EVS, as in the first configuration example, for each pixel column, reflected light from the measurement surface of the object under test 100 is sequentially captured into each pixel constituting the pixel column. Then, based on the captured reflected light, each pixel constituting each pixel column generates a photoelectric conversion signal through photoelectric conversion. The photoelectric conversion signal is output to the event publishing unit 123.

[0213] [Effects]

[0214] Therefore, according to this configuration example, the driving time of the first semiconductor laser 111B and the second semiconductor laser 111C is divided into two equal parts. That is, in this configuration example, the slit light is projected onto each pixel column (column) a total of twice; specifically, the laser from the first semiconductor laser is projected once, and then the laser from the second semiconductor laser is projected once. These laser beams are repeatedly emitted sequentially from the starting point (Y=0; origin O) of the object under test 100 in the transverse (Y) direction to the ending point (Y=L, where L is the entire length of the object under test 100 in the transverse direction) in a cyclic manner.

[0215] Therefore, according to this configuration example, in the light receiving unit 12, reflected light from the first light source 11B and the second light source 11C is sequentially incident on the EVS 122 through the lens 121 in each pixel column. At this time, there is a possibility that secondary reflected light is input from each light source in addition to the conventional reflected light. Therefore, as in the first configuration example, the electrical signal related to the secondary reflected light is removed from the electrical signal output to the signal processing unit 13 by the unwanted signal removal unit 132.

[0216] Furthermore, in the second configuration example according to this disclosure, as described above, among the beams of reflected light (scattered light) emitted from the light source units 11B and 11C and reflected by the measurement surface 100A of the object under test 100, the beam of reflected light traveling on the shortest path toward the light receiving unit 12 enters the light receiving unit 12 as two conventional reflected beams. Additionally, there may be reflected light (secondary reflected light) that is reflected and scattered by the measurement surface 100A and then reflected, for example, by another portion, and enters the light receiving unit 12 while traveling another optical path. Even with such secondary reflected light incident, according to this configuration example, the data obtained from the two beams of conventional reflected light is unique, and therefore, unwanted signals associated with secondary reflected light that generates data different from these data can be later removed by the unwanted signal removal unit 132, as in the first configuration example.

[0217] As a result, a conventional electrical signal generated solely by the conventional reflected light beam of the laser is input to the 3D calculation unit 133. In the 3D calculation unit 133, by using the aforementioned arithmetic expression along with data in the depth (X) direction on the measurement surface 100A of the object under test 100, a value indicating the same height (Z or the same H depth) is obtained from these conventional electrical signals. This scan proceeds in the transverse (Y) direction of the object under test 100 from a starting point (Y=0) to an ending point (Y=L). Consequently, an accurate three-dimensional shape of the object under test 100 can be obtained.

[0218] Therefore, according to this configuration example, EVS is used as an imaging device 122, and can detect accurate three-dimensional shape at high speed even for the test object 100 with large unevenness differences, as in the first configuration example.

[0219] (2-3. Third Configuration Example)

[0220] Next, we will refer to Figure 15 and Figure 16 This description covers a third aspect (hereinafter referred to as "third configuration example") of a shape measuring apparatus 10C according to a second embodiment of the shape measuring system of the present disclosure. Furthermore, in this configuration example, the same reference numerals are used to denote the same parts as in the above configuration example, and repeated descriptions are omitted.

[0221] Although two light source units are used, specifically a first light source unit 11D and a second light source unit 11E, as in the second configuration example, the configuration example of this disclosure differs from the second configuration example in that light beams with different wavelengths are emitted from the first light source unit 11D and the second light source unit 11E. Furthermore, also in this configuration example, as in the second configuration example, the laser oscillation operation of the light source is controlled in a time-division manner by the control signal transmission unit 131 in the signal processing unit 13.

[0222] The first light source unit 11D uses a first semiconductor laser (LD1) 111D that continuously oscillates blue laser light with a blue wavelength (λb) as the light source. On the other hand, the second light source unit 11E uses a laser (LD2) 111E that continuously oscillates laser light with a red wavelength (λr; λr>λb) as the light source.

[0223] It should be noted that the light sources 111D and 111E used in the first light source section 11D and the second light source section 11E can also be light sources with wavelengths having the same bandwidth (e.g., white LDs). In this case, two colors of measurement light can be generated by arranging different color filters in each optical path. Furthermore, for example, a semiconductor laser whose wavelength (λ) can be used, and the laser beams can be distinguished by changing the wavelength (λ). Additionally, the laser beams can be distinguished by nonlinear frequency (ω) conversion devices such as second harmonic generation (SHG) or sum-frequency generation (SFG).

[0224] Similarly, in the first light source unit 11D and the second light source unit 11E of this configuration example, when the object to be measured 100 is scanned sequentially along the horizontal (Y) direction, as in the configuration example described above, when light is projected onto each pixel column at a scanning time interval of Δt seconds, each pixel column is first irradiated with blue laser light from the first light source unit 11D for Δt / 2 seconds. Immediately afterwards, red laser light is continuously emitted from the second light source unit 11E for Δt / 2 seconds. Thereafter, a similar scanning operation is repeated sequentially for each pixel column.

[0225] On the other hand, a single light receiver 12D is provided, and an event-based vision sensor (EVS) similar to that in the second configuration example is used as the imaging device 122. However, in the EVS of this configuration example, the region corresponding to each pixel column is divided into two regions corresponding to the operating time interval of each semiconductor laser. Figure 16As shown, blue filters BF1, BF2, BF3, ... are configured as first filters. These first filters absorb light of wavelengths other than blue and transmit blue light only in a first segmented region (which may be referred to as the "blue region"), which is the front half of the region corresponding to each pixel column. Similarly, red filters RF1, RF2, RF3, ... are configured as second filters. These second filters transmit only red light and absorb the remaining light in a second segmented region (which may be referred to as the "red region"), which is the rear half of each pixel column. Using this configuration, only the blue laser from the first semiconductor laser 111D and the red laser from the second semiconductor laser 111E can be separately incident on the front and rear halves (blue and red regions) of each pixel column.

[0226] [Functions and Effects]

[0227] Therefore, according to this configuration example, the driving time of the first semiconductor laser 111D and the second semiconductor laser 111E is divided into two equal parts. That is, in this configuration example, the blue slit light and the red slit light are projected onto each column in this order. In this way, the two colors of laser light are repeatedly emitted from the starting point (Y=0; origin O) of the object under test 100 in the transverse (Y) direction to the ending point (Y=L, where L is the total length of the object under test 100 in the transverse direction) in a cyclic manner.

[0228] Specifically, in this configuration example, only blue laser light from the first semiconductor laser 111D and red laser light from the second semiconductor laser 111E are allowed to be incident on the first and second halves of the pixel region (blue region and red region) of each pixel column, respectively. Therefore, in the light receiving unit 12, even if the reflected blue light and the reflected red light are mixed into a color such as purple and enter each pixel column (column) of the single EVS 122 through the lens 121, unwanted wavelengths are removed by color filters, i.e., blue filters BF1, BF2, BF3... (which are the first filters) and red filters RF1, RF2, RF3... (which are the second filters). Therefore, only laser light with the desired wavelength can be sequentially incident on each predetermined region. At this time, even if laser light of the same color is selectively incident on each color region in each pixel, it is possible for secondary reflected light of the same color to be simultaneously input. Therefore, even if secondary reflected light of the same color enters a region of the same color, the electrical signal of the secondary reflected light associated with the laser of the same color can be removed from the electrical signal obtained by photoelectric conversion from the EVS output to the signal processing unit 13 by the unwanted signal removal unit 132.

[0229] Furthermore, also in the third configuration example according to this disclosure, as in the second configuration example, among the beams of reflected light (scattered light) emitted from the light source units 11D and 11E and reflected by the measurement surface 100A of the object under test 100, the beam of reflected light traveling on the shortest path toward the light receiving unit 12 enters the light receiving unit 12D as two types of conventional reflected light. Meanwhile, also in this configuration example, there may be reflected light (secondary reflected light) that enters the light receiving unit 12D, for example, after being reflected and scattered by the measurement surface 100A and then reflected by another optical path. Even if such secondary reflected light is incident, according to this configuration example, as in the second configuration example, the unwanted signal caused by the secondary reflected light can be removed by the unwanted signal removal unit 132.

[0230] Therefore, the 3D calculation unit 133, which only receives conventional electrical signals related to the two colors of laser, calculates the three-dimensional shape from the two types of conventional electrical signals using the aforementioned arithmetic expression. The same height (H; or the same depth) value is obtained from either of the laser beams in the same pixel column (column) on the measurement surface 100A of the object under test 100. By scanning the object under test 100 from the starting point (Y=0) to the ending point (Y=L) in the lateral direction, the accurate three-dimensional shape of the object under test 100 can be obtained.

[0231] Therefore, according to this configuration example, as in the first and second configuration examples, by using EVS as the imaging device 122C, even for the test object 100 with large unevenness differences, accurate three-dimensional shape can be detected at high speed.

[0232] Furthermore, the EVS in this configuration example is configured such that laser beams of different wavelengths are incident on two separate designated areas corresponding to the wavelengths of the beams in each pixel column. Therefore, for example, even if light of a color mixed with red and blue light (such as purple) enters a designated area of ​​a characteristic pixel column of the EVS equipped with a blue filter BF as ambient light, this light is blocked by the blue filter BF. Thus, only reflected light from the blue laser can incident on the designated area of ​​the pixel column. Furthermore, this also applies to pixel columns equipped with a red filter RF. This allows for accurate measurement of three-dimensional shapes.

[0233] (2-4. Fourth Configuration Example)

[0234] Next, we will refer to Figures 17 to 19 This invention describes a fourth aspect (hereinafter referred to as "fourth configuration example") of a shape measuring device 10D according to a second embodiment of the shape measuring system of the present disclosure. Furthermore, in this configuration example, the same reference numerals are used to mark the same parts as in the above configuration example, and repeated descriptions are omitted.

[0235] The difference between this configuration example and the third configuration example is that semiconductor lasers LD1 and LD2, which emit laser beams of the same wavelength (λ), are used as light source 111F of the first light source unit 11F and light source 111G of the second light source unit 11G, respectively. Furthermore, unlike the third configuration example, polarizers 114 and 115 with different predetermined functions are attached to the first light source unit 11F and the second light source unit 11G, respectively. It should be noted that completely different types of LDs emitting laser beams with different wavelengths, rather than the same wavelength, can be used as LD1 and LD2.

[0236] [First Light Source Section and Second Light Source Section]

[0237] Semiconductor laser LD1 oscillates and emits substantially circularly polarized (or elliptically polarized) laser light with a specific wavelength (λ). LD2 oscillates and emits substantially circularly polarized (or elliptically polarized) laser light with a similar wavelength to semiconductor laser LD1. There are no particular restrictions on the wavelength of the laser light emitted from these lasers, and any wavelength can be selected.

[0238] In the first light source unit 11F, unlike the third configuration example, in order to emit vertically polarized laser light, the first polarizer 114 is positioned immediately following... Figure 18 The optical path (optical axis A1) of LD1, as shown in Figure A, shapes the polarization plane from circularly polarized (or elliptically polarized) light into vertically polarized light (sometimes referred to as "P-wave" below). Similarly, in the second light source unit 11G, unlike the third configuration example, in order to emit horizontally polarized laser light, a second polarizer 115 is set immediately following... Figure 18 On the optical path (optical axis A2) of LD2 shown in B, the polarization plane is shaped from circularly polarized light (or elliptically polarized light) to horizontally polarized light (sometimes referred to as "S-wave" below).

[0239] [Optical Receiver]

[0240] At the same time, such as Figure 19 As shown, the light receiver 12E of this configuration example, configured as the light receiver 12, is configured such that in the EVS, the region corresponding to each pixel column is divided into two regions, namely, a first segmented region and a second segmented region with only P-wave incident and only S-wave incident, respectively, in a mode similar to the third configuration example. Specifically, films having functions similar to those of the first polarizer 114 and the second polarizer 115, namely, vertical polarizing films FP1, FP2, FP3... as the first film, and horizontal polarizing films FS1, FS2, FS3... as the second film, are respectively provided in the first segmented region (hereinafter referred to as the "P-wave region") and the second segmented region (hereinafter referred to as the "S-wave region"), and the first segmented region and the second segmented region are two segmented regions corresponding to each pixel of each pixel column of the EVS.

[0241] Therefore, similarly in this configuration example, as in the third configuration example, only vertically polarized laser light from the first semiconductor laser and horizontally polarized laser light from the second semiconductor laser can be incident on the corresponding regions (i.e., the front and rear halves of each pixel column), respectively. Thus, in the light receiving unit 12, even if vertical and horizontal polarization planes are mixed in the laser light passing through the lens 121 and incident on each pixel column (column) of the single EVS 122, laser light with unwanted polarization planes (e.g., unwanted secondary reflections) is removed by the vertical polarization film FP and the horizontal polarization film FS, which function similarly to polarizers. Therefore, only laser light with the desired polarization plane can be selectively incident on each region of each pixel column of the EVS.

[0242] Furthermore, also in the fourth configuration example according to this disclosure, as in the third configuration example, among the beams of reflected light (scattered light) emitted from the light source units 11F and 11G and reflected by the measurement surface 100A of the object under test 100, the beam of reflected light traveling on the shortest path toward the light receiving unit 12 enters the light receiving unit 12E as two types of conventional reflected light. Meanwhile, also in this configuration example, there may be reflected light (secondary reflected light) that enters the light receiving unit 12E after being reflected and scattered by the measured surface 100A, for example, by being reflected at another point and traveling through another optical path. Even in this case, as in the first to third configuration examples, unwanted signals generated in association with secondary reflected light can be removed by the unwanted signal removal unit 132.

[0243] Therefore, according to this configuration example, even when the object under test 100 has large unevenness differences, lasers with specified polarization planes can be incident only on the corresponding specified area in each pixel, specifically, vertically polarized lasers and horizontally polarized lasers, as in the first configuration example. As a result, accurate three-dimensional shapes can be detected. Furthermore, even in this configuration example, the EVS is used as an imaging device, and therefore, three-dimensional shapes can be measured at high speed.

[0244] (2-5. Fifth Configuration Example)

[0245] Next, we will refer to Figures 20 to 22 This describes a fifth aspect (hereinafter referred to as "fifth configuration example") of a shape measuring device 10E according to a second embodiment of the shape measuring system of the present disclosure. Furthermore, in this configuration example, the same reference numerals are used to mark the same parts as in the above configuration example, and repeated descriptions are omitted.

[0246] This configuration example differs from the previous configuration example in that a single light source unit 11H is provided. In addition to the white light emitting LD 111H, cylindrical lens 112, and scanning mechanism 113, the light source unit 11H also includes a beam splitter 116. A single light receiving unit 12F is provided, and it includes a color filter 125 immediately before lens 121 in the reflected light path relative to the light receiving unit 12F. The color filter 125 selectively transmits light in three color bands: red (sometimes abbreviated as "R"), green (sometimes abbreviated as "G"), and blue (sometimes abbreviated as "B") wavelengths. It should be noted that the color filter 125 includes a first filter (hereinafter referred to as "filter R") having wavelength transmission characteristics that only transmit R wavelengths, a second filter (hereinafter referred to as "filter G") having wavelength transmission characteristics that only transmit G wavelengths, and a third filter (hereinafter referred to as "filter B") having wavelength transmission characteristics that only transmit B wavelengths.

[0247] [Light Source Department]

[0248] The light source 111H preferably has a wide emission wavelength band. In this configuration example, a semiconductor laser (hereinafter sometimes referred to as "white semiconductor laser 111H") that emits white laser light covering the visible light region with an oscillation wavelength range of 380 nm to 760 nm is used. As the light source 111H, for example, a white LED obtained by coating a blue LED with a phosphorescent material so that a portion of the blue light is converted into green, yellow, and red light can be used, as long as it emits light within a wide bandwidth, but a light source with high brightness and directionality is preferred.

[0249] Prism 116 disperses and splits the white light emitted from white semiconductor laser 111H. The laser light incident on prism 116 in this configuration example is dispersed and split into a spectrum of seven colors after passing through prism 116 due to the difference in refractive index at each wavelength.

[0250] like Figure 21 As shown, the prism 116 in this configuration example roughly divides the incident light into three bands (R, G, and B bands). The three types of incident light α are blue incident light of approximately 380nm to 500nm (hereinafter referred to as B light: α). B ), green incident light in the 500nm to 580nm range (hereinafter referred to as G light: α) G ), and red incident light from 580 nm to 760 nm (hereinafter referred to as R light: α) R It should be noted that in this disclosure, visible light having a wavelength width of, for example, 380 nm to 760 nm can be separated and divided into finer groups. In this case, it is preferable to use a color filter having the same wavelength transmission characteristics as the color filter on the light-receiving side, which will be described later.

[0251] [Optical Receiver]

[0252] The optical receiver 12F is basically the same as the first and second configuration examples described above; however, as mentioned above, such as Figure 20 and Figure 22 As shown, a color filter 125 is also included. Generally, according to the well-known Fermat principle (principle of least action), light of the same wavelength (light incident on the light receiver 12F) travels along a single optical path (the uniquely determined minimum optical path) (i.e., the shortest optical distance) towards and enters the measurement surface of the object under test. Furthermore, the basic principle is that reflected light travels along the same optical path (minimum optical path) as the incident light with the shortest optical distance (reversibility of light) and returns in the same direction.

[0253] This principle is used in this configuration example of the present disclosure. Therefore, ordinary incident light becomes ordinary reflected light and enters each pixel column of EVS 122. That is, the ordinary reflected light of each of colors R, G, and B can enter the corresponding same wavelength region of the three segmented regions of the color filters 125 (i.e., filters R, G, and B) that include the same colors R, G, and B. This is achieved by fixing the housing 14 (see [reference]) to the light receiving section 12. Figure 20 In this light-receiving unit, the color filter 125 can be modularized or unitized into a light-receiving functional unit. Furthermore, if the color filter 125 has a film shape, it can be directly attached to the lens 121.

[0254] Note that, in order to more effectively showcase the wavelength transmission characteristics of color filter 125 and ensure effective capture of conventional reflected light, a lens with high collimation capability is preferably used as lens 121 immediately following color filter 125, so that light that has passed through each color filter section travels to the same pixel in the pixel column. For example, SELFOC (registered trademark) lenses, collimators, etc., can be used. Thus, for example, the return light incident on filter B of color filter 125 and passing through filter B of color filter 125 can be collimated and incident on the corresponding pixel section, instead of being offset relative to the pixel in the depth (X) direction in the pixel column of EVS 122 after passing through lens 121. Color filter 125 can achieve the same effect as the return light of other color components (R component and G component).

[0255] [Functions and Effects]

[0256] Therefore, according to this configuration example, as Figure 20 and Figure 22 As shown, an RGB wavelength light beam emitted, dispersed, and projected onto the object under test 100 from the light source 11H is reflected by the measurement surface 100A and then incident on the color filter 125. Figure 21 As shown, slit light with RGB dispersion (i.e., laser light from 380 nm to 760 nm) emitted from the light source 11H is reflected by the measurement surface 100A. The conventional reflected light in the reflected beam travels along the shortest path with the shortest optical distance compared to other reflected light and then returns towards the color filter 125.

[0257] Each beam of conventionally reflected R, G, and B light incident on color filter 125 can be incident on regions of other color components besides the region of the same color component within color filter 125. However, for example, even B light α B When incident on a region where the color composition differs from that of filter B (i.e., filter R or filter G), light α of filter B... B It is also absorbed by filter R or filter G in this region. Therefore, it prevents B light α from being absorbed. B The light is incident on the pixel corresponding to the R or G light. In this way, only the reflected light of the B component that has already passed through filter B can enter the specific pixel corresponding to filter B. Therefore, for R, G, and B regular reflected light, even if the return light of the R, G, or B color component is strayed as stray light to another R, G, or B color component region, the stray light will not pass through color filter 125 and be absorbed.

[0258] Therefore, according to the fifth configuration example, only conventional reflected light from a specific region of the measurement surface corresponding to the pixel can be incident on each pixel in each pixel column. Thus, there is no possibility of data regarding the shape of other regions within the measurement surface being mixed, and therefore accurate shape measurement can be performed. Furthermore, image information is generated by using conventional reflected light as reflected light reflected from each reflective surface and then incident. Therefore, even with large differences in the unevenness of the measurement surface, an accurate shape of the measurement surface can be generated.

[0259] That is, also in the fifth configuration example according to this disclosure, among the beams of reflected light (scattered light) of R, G, and B emitted from the light source 11H, the beam of reflected light traveling on the shortest path toward the light receiver 12F (dispersed by the prism 116, traveling on different optical paths, and reflected and scattered by the measurement surface 100A of the object under test 100) enters the light receiver 12F as conventional reflected light of R, G, and B, as in the configuration example described above. Meanwhile, also in this configuration example, there is reflected light (secondary reflected light), which, for example, enters the light receiver 12F by traveling through another optical path after being reflected by another portion and then reflected and scattered by the measurement surface 100A. Even with such reflected light, as in the configuration example described above, the data obtained based on the conventional reflected light in the reflected light captured in the R, G, B pixel region 122 is unique. Therefore, in each of the R, G, and B pixel regions 122, unwanted signals related to the secondary reflected light that generates data different from that data can be removed later by the unwanted signal removal unit 132.

[0260] As described above, according to this configuration example, there is a possibility that secondary reflected light of a color component is allowed to pass through the region of the same color component by the color filter 125 in a manner similar to conventional reflected light. However, even if an unwanted signal is generated from the secondary reflected light, as described above, this signal can be removed by the unwanted signal removal unit 132 of the signal processing unit 13. As a result, in each of the R, G, and B pixel regions 122, even if secondary reflected light, which is another of R, G, and B and may cause erroneous data, enters the EVS 122, this can be effectively removed.

[0261] The embodiments and configuration examples of the shape measurement system according to this disclosure have been described above. Finally, the above descriptions of the embodiments and configuration examples are examples of this disclosure, and this disclosure is not limited to the above embodiments and configuration examples. Therefore, it goes without saying that various changes can be made according to design, etc., in addition to the above embodiments and configuration examples without departing from the technical concept of this disclosure. Furthermore, the effects described in this specification are merely examples and are not limiting. Other effects may also exist.

[0262] Furthermore, the accompanying drawings of the above embodiments and configuration examples are schematic, and the dimensional ratios of each part may not necessarily match the actual dimensional ratios. Of course, the drawings also include parts with different dimensional relationships and ratios. As for the vibration state of the light wave of the measurement light described in the above embodiments and configuration examples, various modes such as circularly polarized light, elliptically polarized light, and linearly polarized light can be applied as long as similar effects can be obtained.

[0263] Furthermore, as stated above, the shape measurement system of this disclosure is not particularly limited to the shape measurement of large quantities of products shipped one after another in a factory, for example. That is, this disclosure can be used to capture temporal changes in the observation, monitoring, or measurement of a single target object or a specific target area, whether static or dynamic. For example, this disclosure can be applied to fixed-point observation / monitoring systems, such as cameras for monitoring at a site, cameras in a parking lot, or vehicle-mounted cameras.

[0264] <3. Configurations that can be adopted in this disclosure>

[0265] It should be noted that this disclosure may also have the following configurations.

[0266] (1) A shape measurement system, comprising:

[0267] The light source unit emits measuring light towards the target being measured;

[0268] The light receiving unit receives reflected light, which is the measurement light reflected from the measurement target;

[0269] The signal processing unit includes a three-dimensional shape calculation unit and an unwanted signal removal unit. The three-dimensional shape calculation unit calculates the three-dimensional shape of the measurement target based on event data generated from reflected light reflected by the measurement target and incident on the light receiving unit. The unwanted signal removal unit removes unwanted signals generated when unwanted light other than the reflected light is incident on the light receiving unit from the outside.

[0270] The scanning mechanism scans the measurement target by moving the light source or the measurement target and using the measurement light projected from the light source onto the measurement target.

[0271] (2) According to the shape measurement system described in (1), wherein,

[0272] The scanning mechanism is disposed in the light source unit;

[0273] The light source section includes a light source and a waveform control lens that performs waveform control on the light from the light source; and

[0274] The light receiving unit includes: a light receiving lens; an event-based vision sensor (EVS) that is an asynchronous imaging element that captures the time variation of reflected light passing through the light receiving lens in the beam of reflected light and outputs an event signal; an event publishing unit that detects an event based on output data from the EVS and outputs event data; and a transmitting unit that outputs the event data to the signal processing unit.

[0275] (3) According to the shape measurement system described in (2), wherein

[0276] The light source section is a single light source section; and

[0277] The first and second light receivers, whose positions are offset from each other, are configured as light receivers.

[0278] (4) According to the shape measurement system described in (2), wherein

[0279] A first light source portion and a second light source portion, whose positions are offset from each other, are configured as the light source portions;

[0280] The optical receiver is a single optical receiver; and

[0281] The signal processing unit includes a control signal transmitting unit, which outputs control signals to each of the scanning mechanisms at time intervals in a time-division manner for each pixel column.

[0282] (5) The shape measurement system according to (2), wherein

[0283] The first light source section and the second light source section are configured as the light source section, wherein the first light source section includes a first light source that emits light of a first wavelength and the second light source section includes a second light source that emits light of a second wavelength;

[0284] The optical receiver is a single optical receiver;

[0285] EVS includes two segmentation regions in each pixel column: a first segmentation region and a second segmentation region.

[0286] Of the two different wavelengths of measurement light emitted from the light source, the first wavelength light and the second wavelength light are reflected by the measurement target, and the first segmented region includes a first filter having a first wavelength transmission characteristic that selectively transmits the reflected light of the first wavelength; and

[0287] The second segmented region includes a second filter having a second wavelength transmission characteristic that allows light of the second wavelength to be selectively transmitted.

[0288] (6) The shape measurement system according to (5), wherein

[0289] The first wavelength of light is blue wavelength light, and

[0290] The second wavelength of light is red wavelength light.

[0291] (7) The shape measurement system according to (2), wherein

[0292] A first light source section including a first light source and a second light source section including a second light source are configured as a light source section;

[0293] The first light source includes a first optical element, which generates a first measurement light having a first polarization plane from light emitted from the first light source;

[0294] The second light source includes a second optical element, which generates a second measurement light having a second polarization plane from light emitted from the second light source;

[0295] The optical receiver is a single optical receiver;

[0296] EVS divides each pixel column into two regions: a first segmentation region and a second segmentation region.

[0297] In the first and second measurement lights, a first reflected light having a first polarization plane and a second reflected light having a second polarization plane are reflected by the target and incident on the light receiving unit, and the first segmented region includes a first film that selectively transmits the first reflected light; and

[0298] The second segmented region includes a second film that selectively transmits the second reflected light.

[0299] (8) The shape measurement system according to (7), wherein the first polarization plane is linearly polarized light vibrating in the vertical direction and the second polarization plane is linearly polarized light vibrating in the horizontal direction.

[0300] (9) The shape measurement system according to (2), wherein

[0301] The light source section is a single light source section;

[0302] The light source in the light source section includes a segmentation device for dividing light from the light source into at least three wavelength bands;

[0303] The optical receiver is a single optical receiver;

[0304] EVS divides each pixel column into three segments: the first segmentation region, the third segmentation region, and so on.

[0305] In the measurement light of three different wavelengths emitted from the light source, the reflected light of the three wavelengths is reflected by the measurement target, and the first segmentation region includes a first color filter having wavelength transmission characteristics that selectively transmit the reflected light of the first wavelength among the three wavelengths.

[0306] The second segmentation region includes a second color filter having wavelength transmission characteristics that selectively transmit the reflected light of a second wavelength band among the three wavelength bands reflected by the measurement target; and

[0307] The third segmentation region includes a third color filter, which has wavelength transmission characteristics that selectively transmit the reflected light of the third band of the three bands reflected by the measurement target.

[0308] (10) The shape measurement system according to (9), wherein

[0309] The splitting device includes a prism that splits white light from the light source into three wavelength bands; and

[0310] The three wavelengths of light are red, green, and blue.

[0311] (11) The shape measurement system according to (2), wherein

[0312] EVS compares the signal voltage based on the time-varying nature of the reflected light with a threshold voltage and outputs an event signal by determining whether the signal voltage is less than or greater than the threshold voltage.

[0313] Reference Symbol List

[0314] 1 Shape Measurement System

[0315] 2. Stage (measuring stage)

[0316] 3. Moving mechanism (scanning mechanism)

[0317] 4 Control Department

[0318] 10, 10A to 10E Shape Measuring Devices

[0319] 11 Light Source Section

[0320] 11A First Light Source Section

[0321] 11B Second Light Source Section

[0322] 11D First Light Source Section

[0323] 11E Second Light Source Section

[0324] 11F Light Source Section

[0325] 111 Light Source: Semiconductor Laser (LD)

[0326] 111A First Semiconductor Laser (LD1)

[0327] 111B Second Semiconductor Laser (LD2)

[0328] 111C third semiconductor laser (LD3)

[0329] 111F LD

[0330] 112 Cylindrical lens (waveform forming lens, waveform control lens)

[0331] 113 Scanning Agency

[0332] 114 First Polarizer (Optical Element)

[0333] 115 Second Polarizer (Optical Component)

[0334] 116 prism

[0335] 12, 12C, 12D, 12E, 12F optical receivers

[0336] 12A First Optical Receiver

[0337] 12B Second Optical Receiver

[0338] 121 Light receiving lens

[0339] 122, 122A, 122B Asynchronous (Non-scanning) Imaging Devices (Imaging Elements) (EVS, EVS1, EVS2)

[0340] 123 Incident Release Department

[0341] 124 Sending Department

[0342] 13. Signal Processing Unit (Signal Processing Section)

[0343] 131 Control Signal Transmission Unit

[0344] 132 Do not remove signal

[0345] 133 3D Computing Department

[0346] 134 memory

[0347] 21 Imaging Section

[0348] 211 pixel array

[0349] 212 Drive Unit

[0350] 213 Arbitration Department

[0351] 214 Series Processing Department

[0352] 215 Signal Processing Department

[0353] 210 pixels

[0354] 41 System Control Department

[0355] 42. Motion Control Unit

[0356] 51 Photoelectric Conversion Unit

[0357] 52-pixel signal generation unit

[0358] 53 Address Event Detection Department

[0359] 513 OFG transistor

[0360] 531 Current-to-Voltage Conversion Unit

[0361] 532 Buffer

[0362] 533 Subtractor

[0363] 534 quantizer

[0364] 535 Teleportation Department

[0365] 100 test subjects

[0366] 100A measuring surface

[0367] A1 and A2 optical axes

[0368] BF Blue Filter (First Filter)

[0369] RF red filter (second filter)

[0370] FP vertical polarization film (first film)

[0371] FS horizontal polarizing film (second film)

[0372] FR filter R (first filter)

[0373] FG filter G (second filter)

[0374] FB filter B (third filter)

[0375] H head

[0376] X Depth Direction

[0377] Y (horizontal direction)

[0378] Z-axis

[0379] α-incident light (measuring light)

[0380] α R Red incident light (R light)

[0381] α G Green incident light (G light)

[0382] α B Blue incident light (B-beam)

[0383] β reflected light

[0384] β1 reflected light

[0385] β2 reflected light.

Claims

1. A shape measurement system, comprising: The light source unit emits measuring light towards the target being measured; The light receiving unit receives reflected light, which is the measurement light reflected from the measurement target; The signal processing unit includes a three-dimensional shape calculation unit and an unwanted signal removal unit. The three-dimensional shape calculation unit calculates the three-dimensional shape of the measurement target based on event data generated from reflected light reflected by the measurement target and incident on the light receiving unit. The unwanted signal removal unit compares multiple independent optical data corresponding to the same measurement point on the measurement target, which are captured via multiple optical paths. The multiple independent optical data are generated by reflected light traveling on their respective shortest optical paths. The unit identifies the multiple independent optical data with the same data value as data obtained from conventional reflected light and removes unwanted signals caused by secondary reflected light that generates data different from the conventional reflected light data. The secondary reflected light is multipath reflected light incident on the light receiving unit from a path that is not desired for measurement. as well as The scanning mechanism scans the measurement target by moving the light source or the measurement target and using the measurement light projected from the light source onto the measurement target.

2. The shape measurement system according to claim 1, wherein, The scanning mechanism is disposed in the light source unit; The light source unit includes a light source and a waveform control lens that performs waveform control on the light from the light source; and The light receiving unit includes a light receiving lens, an event-based visual sensor (EVS), an event publishing unit, and a transmitting unit. The event-based visual sensor is an asynchronous imaging element that captures the time change of reflected light passing through the light receiving lens in the beam of reflected light and outputs an event signal. The event publishing unit detects events based on output data from the EVS and outputs event data. The transmitting unit outputs the event data to the signal processing unit.

3. The shape measurement system according to claim 2, wherein, The light source unit is a single light source unit; and As the light receiving unit, a first light receiving unit and a second light receiving unit are provided with positions offset from each other.

4. The shape measurement system according to claim 2, wherein, As the light source unit, a first light source unit and a second light source unit are provided with positions offset from each other; The optical receiver is a single optical receiver; and The signal processing unit includes a control signal transmitting unit, which outputs control signals to each of the scanning mechanisms at time intervals in a time-division manner for each pixel column.

5. The shape measurement system according to claim 2, wherein, As the light source unit, a first light source unit and a second light source unit are provided. The first light source unit includes a first light source that emits light of a first wavelength and the second light source unit includes a second light source that emits light of a second wavelength. The optical receiver is a single optical receiver; The EVS includes two segmentation regions in each pixel column: a first segmentation region and a second segmentation region. Of the two different wavelengths of measurement light emitted from the light source, the first wavelength light and the second wavelength light are reflected by the measurement target, and the first segmented region includes a first filter having a first wavelength transmission characteristic that selectively transmits the reflected light of the first wavelength; and The second segmentation region includes a second filter, which has a second wavelength transmission characteristic that allows light of the second wavelength to be selectively transmitted.

6. The shape measurement system according to claim 5, wherein, The first wavelength of light is blue wavelength light, and The second wavelength of light is red wavelength light.

7. The shape measurement system according to claim 2, wherein, As the light source unit, a first light source unit including a first light source and a second light source unit including a second light source are provided; The first light source includes a first optical element, which generates a first measurement light having a first polarization plane from light emitted from the first light source; The second light source includes a second optical element, which generates a second measurement light having a second polarization plane from light emitted from the second light source; The optical receiver is a single optical receiver; The EVS divides each pixel column into two regions: a first segmentation region and a second segmentation region. In the two measurement lights, the first measurement light and the second measurement light, the first reflected light having the first polarization plane and the second reflected light having the second polarization plane are reflected by the measurement target and incident on the light receiving unit, and the first segmented region includes a first film that selectively transmits the first reflected light; and The second segmented region includes a second film that selectively transmits the second reflected light.

8. The shape measurement system according to claim 7, wherein, The first polarization plane is for linearly polarized light vibrating in the vertical direction, and The second polarization plane is linearly polarized light that vibrates in the horizontal direction.

9. The shape measurement system according to claim 2, wherein, The light source unit is a single light source unit; The light source in the light source section includes a segmentation device for dividing light from the light source into at least three wavelength bands; The optical receiver is a single optical receiver; The EVS includes three segmentation regions for each pixel column: a first segmentation region to a third segmentation region. Among the three different wavelengths of measurement light emitted from the light source, the reflected light of the three wavelengths is reflected by the measurement target, and the first segmentation region includes a first filter having wavelength transmission characteristics that selectively transmit the reflected light of the first wavelength among the three wavelengths. The second segmentation region includes a second filter, which has wavelength transmission characteristics that selectively transmit the reflected light of the second band among the three bands of reflected light reflected from the measurement target; and The third segmentation region includes a third filter having wavelength transmission characteristics that selectively transmit the reflected light of the third band among the three bands of reflected light reflected from the measurement target.

10. The shape measurement system according to claim 9, wherein, The splitting device includes a prism that splits white light from the light source into three wavelength bands; and The three wavelengths of light are red, green, and blue.

11. The shape measurement system according to claim 2, wherein, The EVS compares the signal voltage based on the time-varying nature of the reflected light with a threshold voltage, and outputs an event signal by determining whether the signal voltage is less than or greater than the threshold voltage.

Images