WO2016143482A1

WO2016143482A1 - Optical detection device

Info

Publication number: WO2016143482A1
Application number: PCT/JP2016/054836
Authority: WO
Inventors: 染野　義博; 山下　龍麿; 孝文青木; 秀作遊佐; 尚大関口; 智浩鈴木; 岩本　正美; 弘一安藤; 川人　祥二
Original assignee: アルプス電気株式会社; 国立大学法人東北大学
Priority date: 2015-03-10
Filing date: 2016-02-19
Publication date: 2016-09-15
Also published as: JP2016166814A; JP6531326B2

Abstract

According to the present invention, a pulse oscillation circuit (15) causes a measurement light emitted from a light source (11) to become a light having an intensity modulation and being emitted intermittently, and said measurement light is converted by a hologram element or the like into a projection pattern having a high-luminance portion and a low-luminance portion, and is applied to a target object. Using light, from among the light received by a light receiving element (21), that is reflected from the high-luminance portion, phase difference is detected by a phase difference detection circuit (31), and distance is calculated by a Z distance calculation unit (32). Furthermore, using light, from among the light received by the light receiving element (21), that is reflected from the low-luminance portion, information for X-Y coordinates of the target object is obtained by an X-Y position calculation unit (34). This makes it possible to obtain three-dimensional information for a measured target object with high accuracy by means of relatively low-power driving.

Description

Optical detector

The present invention relates to an optical detection device capable of detecting a phase difference of light reflected from an object and measuring a distance from the object.

Patent Document 1 describes a system having an illumination unit that converts detection light from a coherent light source into a random speckle pattern and irradiates the object, and an imaging device that receives light reflected from the object. ing. In this system, a three-dimensional survey is performed by the illumination unit and the imaging device. Random speckle pattern deviation between the reflection pattern from the measurement object detected by the imaging device when the measurement object moves to the measurement area and the reference image obtained when the measurement object does not exist Is detected, and a three-dimensional map of the object to be measured is constructed.

Patent Document 2 describes a detection method in which light from a light source is intensity-modulated and irradiated onto an object. In this method, the reflected light from the object is received by the photoelectric conversion unit, and the distance to the object existing in the space is obtained by calculating the phase difference between the light emitted from the light emitting source and the light received by the photoelectric conversion unit. Is required.

Japanese Patent No. 5001286 Japanese National Patent Publication No. 10-508736

The system described in Patent Document 1 may be suitable for quantifying the shape of the object, but to obtain the three-dimensional information of the object from the detection value of the deviation of the random speckle pattern. Since a huge amount of calculation is required, it is not possible to expect an increase in processing speed.

The method described in Patent Document 2 can directly obtain distance information by measuring a phase difference between light emitted from a light emitting source and light acquired by a photoelectric conversion unit. However, in the method described in Patent Document 2, since a laser light source is used to reduce the influence of disturbance light, it is easily affected by speckle noise, and noise is generated near the edge of the object. Measurement errors are likely to occur. In addition, since the photoelectric conversion unit obtains a phase difference with respect to reflected light from the entire irradiation field of light, in order to accurately detect the phase difference in each pixel, a considerably large emission energy is required. Become.

Furthermore, if it is attempted to obtain the planar shape of the object by the method described in Patent Document 2, it is necessary to perform analysis by image processing using luminance information from all pixels. growing.

The present invention solves the above-described conventional problems, and can effectively detect the distance information of an object by effectively using light energy from a light source, and further relates to a planar shape of the object. An object of the present invention is to provide an optical detection device that can also acquire information.

The present invention includes a light source, a light source driver that emits intensity-modulated measurement light from the light source,
An optical conversion element that converts the measurement light into a predetermined projection pattern and projects the measurement light onto a target; a light-receiving element that receives the measurement light reflected from the target; and a control unit. A light irradiation area formed by converging light emitted from the light source at a plurality of locations and projected onto the object, and a light non-irradiation area that fills the space between the light irradiation areas, , Calculating a distance information in the Z direction from the light receiving element to the light irradiation region by obtaining a phase difference of light from a light receiving output obtained by receiving the light of the light irradiation region by the light receiving element. is there.

In the present invention, the control unit can detect the contour of the object by monitoring the continuity of the light intensity change of the reflected light from the projection pattern.

In the optical detection device of the present invention, the light irradiation region includes a high luminance portion having a high light luminance and a low luminance portion having a light luminance lower than that of the high luminance portion. It is preferable to calculate distance information in the Z direction from the phase difference.

In this case, the control unit can detect the contour of the object by monitoring the continuity of the light intensity change of the reflected light from the low luminance part.

In addition, the present invention calculates distance information in the Z direction from the phase difference of the light in the light irradiation region and monitors the continuity of the light intensity change of the reflected light from the same light irradiation region. It is also possible to detect the contour.

The optical detection device of the present invention can calculate the three-dimensional shape of the object from distance information in the Z direction and the contour.

In the present invention, for example, the projection pattern is a dot pattern. However, the pattern shape of the light irradiation region may be anything.

The present invention uses an optical conversion element to collect measurement light emitted from a light source at a plurality of locations to form a plurality of light irradiation regions. Therefore, the projection pattern of the light irradiated to the object has a plurality of light irradiation regions and a light non-irradiation region that fills between the light irradiation regions.

The present invention detects the phase difference of the light from the light reception output from the light irradiation region formed by collecting the light and obtains distance information (depth information) in the Z direction of the object. When calculating the information in the Z direction, the S / N ratio when obtaining the information in the Z direction can be increased by concentrating the light energy on the light and calculating the phase difference of the light from the reflected light from the light irradiation region. Measurement accuracy can be improved. Further, since the light can be concentrated on the light irradiation region, it is possible to obtain strong resistance against external light such as sunlight.

In addition, since the reflection intensity of light differs between a measurement object such as a hand and an object present in the background of the object, the continuity of the intensity of the reflected light of the light projected in a predetermined projection pattern is monitored. Thus, it is possible to grasp the boundary portion of the measurement object. In particular, when the object is moving, it is easy to detect the boundary of the object.

In a preferred example of the present invention, the light irradiation region is divided into a high luminance portion and a low luminance portion, and a projection pattern is formed by the high luminance portion and the low luminance portion. In this case, the phase difference of the light is detected from the light receiving output of the high luminance portion to obtain distance information in the Z direction, and the continuity of the light intensity is monitored from the light receiving output of the low luminance portion to detect the boundary portion of the object. It is preferable to detect.

By dividing the light irradiation area into a high-luminance part and a low-luminance part, by providing a threshold value for the light reception output, it is a light reception output for calculating the distance in the Z direction by phase difference detection, or an intensity change It becomes easy to discriminate whether the received light output is for detecting the boundary portion of the object by monitoring continuity, and it becomes easier to calculate by dividing the depth detection and the XY information detection.

Also, by increasing the light energy for obtaining the information in the Z direction, the distance information in the Z direction can be detected with high accuracy while being hardly affected by external light.

In the present invention, in particular, by making the projection pattern a dot pattern, it becomes easier to concentrate light energy on the high-luminance part, and it is possible to improve the detection accuracy of distance information in the Z direction. By using this dot pattern, the shape of the boundary portion of the object can be detected with high accuracy.

The side view which shows the structure of the optical detection apparatus of the 1st Embodiment of this invention, A photograph showing an example of a projection pattern of measurement light according to the first embodiment; A plan view showing an example of a light receiving element, Time chart showing processing operation of received light output, (A) (B) is a diagram showing the effect of the embodiment of the present invention, Block diagram of optical detection device, Explanatory drawing which shows an example of the projection pattern of the measurement light of 2nd Embodiment,

FIG. 1 shows the structure of the optical detection device 1 according to the first embodiment of the present invention, and FIG. 6 shows a circuit block diagram of the optical detection device 1.
As shown in FIG. 1, the optical detection device 1 includes a projection device 10 and a light receiving device 20.

The projection device 10 includes a light source 11, one or more projection lenses 12 that convert measurement light emitted from the light source 11 into collimated light or divergent light, and an optical conversion element 13 that converts the measurement light into a predetermined projection pattern. Have. The light source 11 is a laser diode (LD) element that emits invisible light. In the embodiment, an LD element that emits near infrared light or infrared light is used.

The optical conversion element 13 is a hologram element, which converts the measurement light emitted from the light source 11 into a predetermined projection pattern and irradiates the object. As shown in FIG. 2, the light irradiation pattern has a high luminance part d1 and a low luminance part d2 having a luminance lower than that of the high luminance part d1. The hologram element can diffract light passing therethrough and concentrate light energy in a predetermined spatial region. A portion where light is concentrated at a higher density becomes the high luminance portion d1, and a portion where the light concentration rate is lower than that is the low luminance portion d2.

FIG. 2 shows a state in which the measurement light is irradiated on the object (hand H) by the projection pattern converted by the optical conversion element 13 in the first embodiment.

Both the high-luminance part d1 and the low-luminance part d2 defined as light irradiation areas are spot-like (dot-like). A region that fills between the high luminance portion d1 and the low luminance portion d2 and that appears dark in FIG. 2 is a light non-irradiation region.

The light non-irradiation region does not mean a region where no light is applied, but the light concentration rate is extremely low compared to the high luminance portion d1 and the low luminance portion d2 where the light is concentrated, and the high luminance portion This is a region that is considered to be hardly exposed to light as compared with d1 and the low luminance portion d2.

Any arrangement pattern may be used for the high luminance portion d1 and the low luminance portion d2, but in the example shown in FIG. 2, both the high luminance portion d1 and the low luminance portion d2 are regularly arranged in a fixed pattern. ing. In the standard pattern shown in FIG. 2, the spot (dot), which is the light irradiation area, is 8 × 8 as one unit, the high-luminance part d1 is located at four corners of the unit, and the other 60 spots ( Dot) is the low luminance part d2. The units are arranged in the XY direction with the regularity that the adjacent units share the column and the row in which the high luminance part d1 exists.

However, the high luminance part d1 and the low luminance part d2 may be arranged randomly, or the high luminance part d1 is formed in a linear shape so as to cross and extend in the XY direction, The low luminance portion d2 may be formed in a linear shape between the high luminance portions d1, or may be formed in a spot shape (dot shape).

As shown in FIG. 6, a light source driver 14 is connected to the light source 11. The light source driver 14 applies intensity modulation to the measurement light emitted from the light source 11. In this embodiment, a pulse oscillation circuit 15 is connected to the light source driver 14, and measurement light is intermittently emitted from the light source 11 by the light source driver 14.

As shown in FIG. 1, the light receiving device 20 includes a light receiving element 21, at least one light receiving lens 22 positioned in front of the light receiving element 21, and a filter 23 disposed in front of the light receiving lens 22. The filter 23 is configured to transmit a light emission wavelength (infrared light in this embodiment) corresponding to the wavelength of the light source and to block other wavelengths such as visible light.

The light receiving element 21 acquires the reflected light from the high luminance part d1 and the low luminance part d2 irradiated on the entire object (the hand H in the example of FIG. 2) located near the surface of the projection reference plane (background) 2. Light can be received with a possible angle of view.

The light receiving element 21 has a plurality of pixels regularly arranged in the X direction and the Y direction. Each pixel has a lateral electric field control type charge modulation pixel structure (LEFM) schematically shown in FIG.

FIG. 4 shows the operation timing of the LEFM. In LEFM, light received by a pixel (PC) is acquired at a predetermined timing in each of a gate G1 (TX1), a gate G2 (TX2), and a gate G3 (TXD), and this is repeated in a predetermined accumulation period. . The charge accumulated during the accumulation period is taken out during the readout period.

As shown in FIG. 4, the emission period of the measurement light emitted from the light source 11 is T0, and the delay time Td of the reflected light (pulse light) detected by the pixel. If the distance L to the object is zero, there is no phase difference between the light emitting period T0 and the light receiving period Td, so that all charges when the reflected light is received are transferred from the gate G3. Conversely, the longer the distance L, the longer the light receiving period Td takes for the transfer time of the gate G2, and a part of the charge when receiving the reflected light is transferred from the gate G2.

Therefore, when the output at the node of the gate G1 is S1, the output at the node of the gate G2 is S2, and the output at the node of the gate G3 is S3, the distance L from the LEFM to the light irradiation point is
L = (cT0 / 2) × {(S2-S1) / (S2 + S3-2S1)} (Equation 1)
It is represented by (S2 + S3-2S1) is a calculated value for canceling light other than the light emission period T0, that is, outside light. Similarly, (S2-S1) is also a calculated value that eliminates the effect of external light.

When S2-S1 is zero, the distance L is zero. When the entire light receiving period Td enters the transfer period of the gate G2, the distance L becomes the maximum value (cT0 / 2).

Thus, by applying intensity modulation to the light emitted from the light source 11 and configuring the pixels with LEFM, the distance L from the light receiving element 21 to the object can be known based on the light receiving output.

The light receiving element 21 receives both the reflected light from the high luminance part d1 and the reflected light from the low luminance part d2 shown in FIG. The light receiving output from the LEFM of the pixel that receives the reflected light from the high brightness portion d1 is high, and the light receiving output from the LEFM of the pixel that receives the reflected light from the low brightness portion d2 is low, and the reflection from the light non-irradiation region The light reception output from the LEFM of the pixel that receives light is further lowered.

A predetermined threshold value is set in the pixel processing circuit 24 shown in FIG. 6, and a light receiving output larger than the threshold value among the light receiving outputs from the LEFM is given to the phase difference detecting circuit 31. The calculation of Equation 1 is performed. That is, the distance L is calculated based only on the reflected light from the high luminance part d1.

As shown in FIG. 2, the measurement light emitted from the light source 11 is concentrated on the spot-like (dot-like) high-intensity part d1 by the optical conversion element 13 constituted by a hologram element. Since the light energy collected in the high luminance part d1 is extracted by setting the threshold value and the phase difference is detected, it is possible to efficiently use the light energy from the light source 11 for distance measurement. Become. Therefore, even if the output of the light source 11 is limited, the irradiation range of the measurement light can be widened, and the distance can be measured in a wide irradiation range. In addition, the reflected light from the spot-like (dot-like) high-luminance portion d1 has a high intensity, and the phase difference is measured using this high-intensity detection output, so that the S / N ratio can also be improved. In addition, resistance to external light such as sunlight can be increased.

FIG. 5A shows a case where measurement light is projected with the projection pattern which is the dot pattern shown in FIG. 2 and a case where simple diffused light is given as measurement light to the object without using the optical conversion element 13. The distance measurement results at and are shown. FIG. 5B shows a case where measurement light is projected with the projection pattern which is the dot pattern shown in FIG. 2 and a case where simple diffused light is given as measurement light to the object without using the optical conversion element 13. It shows the dispersion of the measured value of the distance between and.

5A and 5B, the horizontal axis indicates the reciprocal of the voltage applied to the light source driver 14 that causes the light source 11 to emit light, and the voltage decreases as it proceeds to the right. Therefore, the light emission intensity from the light source 11 Will decline. The vertical axis represents the distance L measured by the above mathematical formula. The number of pixels used for the measurement is 3 × 3 pixels including a region irradiated with one dot-like high luminance part d1. The effective distance, which is a measurable distance range based on the pulse width of the light source, was set to 500 mm. In the lower part of each measurement point in FIG. 5, the number of frames from which the effective distance measurement value was obtained is described.

As shown in FIGS. 5A and 5B, by using a projection pattern that is a dot pattern, even if the emission intensity from the light source 11 is lowered, the number of frames that can obtain an effective measurement value is large. In addition, it can be seen that the variation in the distance detection value is small.

At this time, the light intensity output from the light source is P, and the energy efficiency of the diffraction grating for forming the dots in the high luminance portion is λ. In the case of a divergent light source, the average light intensity per unit area in the light irradiation region is Pdiff, and in the case of dot pattern light, the average light intensity per unit area in one spot (dot) is Pdot. If the light intensity P from the light source is common, and K = Pdot / Pdiff is sufficiently larger than 1, the irradiation method using the dot pattern is more suitable for the signal light with respect to the background light than the diverging light irradiation method. The ratio will be large, and it will be more resistant to ambient light.

Assuming that the diffused light irradiation area is S, the average area of one spot (dot) in the dot pattern irradiation method is a, and the total number of spots (dots) is N, Pdiff = P / S and Pdot = (λ · Since P) / (N · a), K = (λ · S) / (N · a), and the condition that the dot pattern irradiation method can be more accurate than the diverging light irradiation method is (λ · S). ) / (N · a) >> 1.

In the example shown in FIGS. 1 and 2, the object to be measured is the hand H, and the hand H is moving on the projection reference plane 2.

As shown in FIG. 6, the light reception output received by the LEFM of each pixel of the light receiving element 21 is given to the pixel processing circuit 24, and the output whose light reception output is larger than the threshold value is detected by the control unit 30. An output smaller than the threshold value is given to the circuit 31 and given to the dot pattern detection circuit 33.

Preferably, outputs are alternately supplied from the pixel processing circuit 24 to the phase difference detection circuit 31 and the dot pattern detection circuit 33 in a time division manner.

The control unit 30 includes a CPU, a memory, and the like, and processing operations corresponding to the block diagram shown in FIG. 6 are executed by preinstalled software.

The phase difference detection circuit 31 executed by the control unit 30 is provided with a detection output larger than the threshold value among the light reception outputs received by the LEFM of each pixel, and S1, S2 and S3 are detected from the detection output. Accumulated values of the respective outputs are obtained, and the Z distance calculation unit 32 performs the calculation shown in the above equation 1 so that the distance L from the measurement light irradiation point to the light receiving element 21 in a state where disturbance light components are removed. Is measured. This distance is acquired as distance information of each high-luminance part d1 distributed in a dot shape.

In the dot pattern detection circuit 33 of the control unit 30, the detection output that is smaller than the threshold value among the detection outputs obtained by the pixel processing circuit 24 and mainly the detection output from the low luminance part d 2 is extracted.

The dot pattern detection circuit 33 monitors the continuity of the received light intensity (the amount of received light) of the reflected light from the low luminance part d2. Since the reflectance of light is different between the surface of the hand H, which is the object, and the projection reference plane (background) 2, when the hand H moves, the light from the low luminance part d2 located at the boundary of the hand H The intensity of the reflected light changes. Therefore, the position of the boundary part of the hand can be measured by monitoring the continuity of the intensity of the reflected light from the low luminance part d2. In the control unit 30, the dot pattern detection circuit 33 monitors the continuity of the intensity of the reflected light from each low-brightness unit d 2, and the result is given to the XY position calculation unit 34 for XY position calculation. In the part 34, the outer shape of the hand H is determined.

The Z distance information obtained from the reflected light of the high luminance part d1 and the XY coordinate information obtained from the reflected light of the low luminance part d2 are given to the main arithmetic circuit 35. The main arithmetic circuit 35 can grasp the three-dimensional shape of the surface of the hand H, which is the object, from the distance information of each high brightness portion d1, and the hand H from the XY coordinate information obtained from each low brightness portion d2. The shape (contour information) can be grasped, and by integrating these, the three-dimensional shape of the hand H that is the object can be grasped. Further, since the distance from the projection device 10 or the light receiving device 20 to the hand H can be grasped, it is possible to measure how much the hand H is lifted from the projection reference plane 2.

Further, by grasping the disappearance of the reflected light from the low brightness portion d2 and the disappearance of the reflected light from the respective high brightness portions d1 distributed on the XY coordinates on the surface of the hand H, the hand H becomes X The moving speed and acceleration information when moving in the -Y direction can be obtained.

Note that it is also possible to determine the outer shape of the hand H by monitoring the continuity of the Z distance information obtained from the reflected light of the high luminance part d1.

In the optical detection device 1 shown in FIG. 1, the optical axis O1 of the projection device 10 and the optical axis O2 of the light receiving device 20 are separated from each other, and are not positioned on the same geometrical axis. However, the distance between the optical axis O1 and the optical axis O2 is set sufficiently shorter than the distance L to the hand H that is the object. Therefore, even if the hand H moves and the dot portion of the high luminance portion d1 irradiated on the hand H moves in the Z direction, the reflected light from the high luminance portion d1 when the light is received by the light receiving element 21. The amount of movement in the XY direction is very small and can be ignored in calculation. In such a state, it can be said that the optical axis O1 and the optical axis O2 are substantially coaxial, and the movement of the dots in the XY direction is the shortest. Accuracy can be improved.

However, in the present invention, the optical axis O1 and the optical axis O2 are not located substantially on the same axis, and the hand H is moved, for example, so that the high brightness portion d1 (and the low brightness portion) irradiated to the hand H is reduced. When the dot portion of the luminance portion d2) moves in the Z direction, the dot of reflected light received by the light receiving element 21 may be detected as moving on a so-called epipolar line in three-dimensional measurement. That is, the movement information in the Z direction can be detected using the phase change of the high luminance part d1, and the contour information can be detected based on the movement information of the high luminance part d1 and the low luminance part d2. In this case, since it is possible to detect the outline information simply by reading the movement information of the dot pattern, the processing is easy, and the movement information in the Z direction is targeted for the phase change of the high luminance part d1. Therefore, it is easy to detect.

In the above embodiment, the light irradiation area obtains the movement information in the Z direction at the high luminance part d1 and obtains the coordinate information in the XY direction at the low luminance part d2, but the high luminance part d1 and the low luminance part d1. The coordinate information in the XY directions may be detected by using both of the parts d2, that is, the boundary part of the hand H and the movement of the hand may be detected.

FIG. 7 shows a state in which the measurement light is irradiated on the object (hand H) by the projection pattern converted by the optical conversion element 13 in the second embodiment.

In the second embodiment, the measurement light emitted from the light source 11 is converted by the optical conversion element 13 to form a projection pattern that forms a dot-shaped (spot-shaped) light irradiation region d. The shape of each light irradiation region d is circular, and each light irradiation region d is arranged at the same pitch in two orthogonal directions. Alternatively, they are arranged at different pitches in two orthogonal directions. Further, all the light irradiation areas d have uniform luminance. A region where the light irradiation region d is not formed, that is, a region filling the space between the light irradiation regions d is a light non-irradiation region.

In this projection pattern, the reflected light from all the light irradiation areas d is received by LEFM, the light reception output is given to the phase difference detection circuit 31, and the calculation of Equation 2 is performed. The distance L is calculated every time. However, any one of the plurality of light irradiation regions d shown in FIG. 7 may be selected, a phase difference may be obtained from the received light output from the selected light irradiation region d, and the distance L may be calculated. For example, the light irradiation regions d arranged every several in two orthogonal directions are selected, and the distance L is calculated.

It is also possible to detect the boundary portion of the hand H that is the object by monitoring the continuity of the light intensity of the reflected light from each light irradiation region d.

Also in the second embodiment, since the measurement light from the light source 11 is aggregated by the optical conversion element 13 to form the light irradiation region d, the phase difference of the reflected light from the light irradiation region d is determined. By determining, the distance L can be determined with a high S / N ratio. Therefore, it is possible to determine the outer shape of the hand H by monitoring the continuity of the distance L.

Note that the high luminance part d1 and the low luminance part d2 of the first embodiment or the light irradiation region d of the second embodiment may be a linear pattern or a graphic pattern other than a circle. Alternatively, the high luminance part d1 may be formed large and the low luminance part d2 may be formed small. Further, the high luminance part d1, the low luminance part d2, or the light irradiation region d may be arranged at random.

Further, the diffraction structure of the optical conversion element 13 that converts the light from the same light source 11 is changed in a time-sharing manner, so that the projection pattern of only the high luminance part d1 and the projection pattern of only the low luminance part d2 are alternately given to the object. It is also possible.

DESCRIPTION OF SYMBOLS 1 Optical detection apparatus 10 Projection apparatus 11 Light source 13 Optical conversion element 14 Light source driver 20 Light receiving device 21 Light receiving element 22 Light receiving lens 24 Pixel processing circuit 30 Control part d1 High brightness part d2 Low brightness part d Light irradiation area

Claims

A light source, a light source driver that emits intensity-modulated measurement light from the light source, an optical conversion element that converts the measurement light into a predetermined projection pattern and projects it onto an object, and the measurement reflected from the object A light receiving element for receiving light and a control unit;
The projection pattern includes a light irradiation region formed by projecting the light emitted from the light source at a plurality of locations and projecting the target, and a light non-irradiation region that fills the space between the light irradiation regions,
The control unit calculates a phase difference of light from a light reception output received by the light receiving element of light in the light irradiation region, and calculates distance information in the Z direction from the light receiving element to the light irradiation region. An optical detection device.
The optical detection device according to claim 1, wherein the control unit detects the contour of the object by monitoring the continuity of the light intensity change of the reflected light from the projection pattern.
The light irradiation region has a high luminance part having a high light luminance and a low luminance part having a light luminance lower than that of the high luminance part, and the distance in the Z direction from the phase difference of the light of the high luminance part. The optical detection device according to claim 1, which calculates information.
The optical detection device according to claim 3, wherein the control unit detects the contour of the object by monitoring the continuity of the light intensity change of the reflected light from the low-luminance unit.
The contour of the object is detected by calculating distance information in the Z direction from the phase difference of light in the light irradiation region and monitoring the continuity of the light intensity change of reflected light from the same light irradiation region. 2. The optical detection device according to 2.
6. The optical detection device according to claim 2, wherein a three-dimensional shape of the object is calculated from distance information in the Z direction and the contour.
The optical detection device according to any one of claims 1 to 6, wherein the projection pattern is a dot pattern.