JP2014085282A - Information acquisition device and object detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information acquisition device and an object detection device employing the information acquisition device that easily enable a design of a dot pattern such that uniqueness of the dot pattern is secured in a search range of a reference area, and so as to distribute dots at preliminarily set density and uniformly as much as possible.SOLUTION: The information acquisition device acquires distance information on the basis of a reference image imaged by a CMOS image sensor when a reference surface is irradiated with laser light having a dot pattern and an actual measurement image imaged by the CMOS image sensor when actually measured. Herein, the dot pattern is configured such that the dot pattern includes the same number of dots, any of a plurality of dot units U0 to U4 different in a distribution from each other is arranged periodically in a lateral direction, and further the number of dot units included in one line and the number of dot units included in a line adjacent to the line are different from each other.

Description

  The present invention relates to an object detection apparatus that detects an object in a target area based on the state of reflected light when light is projected onto the target area, and an information acquisition apparatus suitable for use in the object detection apparatus.

  Conventionally, object detection devices using light have been developed in various fields. An object detection apparatus using a so-called distance image sensor can detect not only a planar image on a two-dimensional plane but also the shape and movement of the detection target object in the depth direction. In such an object detection apparatus, light in a predetermined wavelength band is projected from a laser light source or an LED (Light Emitting Diode) onto a target area, and the reflected light is received by a light receiving element such as a CMOS image sensor.

  As such a distance image sensor, a distance image sensor of a type that irradiates a target region with laser light having a predetermined dot pattern is known (Non-Patent Document 1). In such a distance image sensor, a dot pattern when the reference surface is irradiated with laser light is picked up by the image pickup device, and the picked-up dot pattern is held as a reference dot pattern. Then, the reference dot pattern is compared with the actually measured dot pattern captured at the time of actual measurement, and distance information is acquired. Specifically, distance information with respect to the reference region is acquired by a triangulation method based on the position of the reference region set on the standard dot pattern on the measured dot pattern.

  In this case, for example, a region including a dot that most closely matches the dot included in the reference region is searched for on the actually measured dot pattern. The searched area is acquired as the movement position of the reference area. For such a search, the dots included in the reference area must be arranged in a unique pattern that can be distinguished from the dots included in other reference areas. For this reason, the dot pattern of the laser beam irradiated to the target area is usually an irregular and random dot pattern.

19th Annual Conference of the Robotics Society of Japan (September 18-20, 2001) Proceedings, P1279-1280

  As described above, in the object detection apparatus, it is necessary to ensure the uniqueness of the dot pattern in the search range of the reference area. Further, it is desirable that the dots irradiated to the target area are distributed as uniformly as possible with a preset density. However, it is difficult to design a dot pattern so as to satisfy such a condition.

  The present invention has been made in view of this point, and the uniqueness of the dot pattern is ensured in the search range of the reference region, and the dots are distributed as uniformly as possible with a preset density. An object of the present invention is to provide an information acquisition device capable of easily designing a dot pattern and an object detection device using the information acquisition device.

A first aspect of the present invention relates to an information acquisition device. The information acquisition apparatus according to this aspect is arranged so as to be aligned in a first direction with respect to the projection optical system that projects laser light emitted from a laser light source onto a target area with a predetermined dot pattern. A light receiving optical system that images the target area with an image sensor, and a distance acquisition unit that acquires distance information related to a distance to an object included in the target area based on an actual image captured by the image sensor during actual measurement; . The dot pattern includes the same number of dots, and any of a plurality of unit regions having different distributions is periodically arranged in the first direction, and further included in a row in the first direction. The number of types of unit regions and the number of types of unit regions included in a row adjacent to the row in a second direction perpendicular to the first direction are different from each other. .

  A 2nd aspect of this invention is related with an object detection apparatus. The object detection apparatus according to this aspect includes the information acquisition apparatus according to the first aspect and an object detection unit that detects a predetermined target object based on the distance information.

  According to the present invention, the dot pattern can be easily designed so that the uniqueness of the dot pattern is ensured in the search range of the reference area, and the dots are distributed as uniformly as possible in a preset density. An acquisition apparatus and an object detection apparatus using the acquisition apparatus can be provided.

  The effects and significance of the present invention will become more apparent from the following description of embodiments. However, the embodiment described below is merely an example when the present invention is implemented, and the present invention is not limited to the following embodiment.

It is a figure which shows the structure of the object detection apparatus which concerns on embodiment. It is a figure which shows the structure of the information acquisition apparatus and information processing apparatus which concern on embodiment. It is a figure which shows the irradiation state of the laser beam with respect to the target area | region which concerns on embodiment, and the light reception state of the laser beam on an image sensor. It is a figure explaining the production | generation method of the reference pattern which concerns on embodiment. It is a figure explaining the distance detection method which concerns on embodiment. 6 is a diagram for explaining a dot pattern design method according to Embodiment 1. FIG. It is a figure explaining the uniqueness of the dot pattern which concerns on Example 1. FIG. 6 is a diagram illustrating a dot pattern design method according to Embodiment 2. FIG. FIG. 9 is a diagram illustrating a dot pattern design method according to a third embodiment. FIG. 10 is a diagram illustrating a dot pattern design method according to Example 4; FIG. 10 is a diagram illustrating a dot pattern design method according to Example 5; It is a figure which shows the design method of the dot pattern which concerns on Example 6. FIG. FIG. 10 is a diagram illustrating a dot pattern design method according to a seventh embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the embodiment described below, the CMOS image sensor 240 corresponds to an “image sensor” recited in the claims. The X-axis direction and the Y-axis direction correspond to a “first direction” and a “second direction” recited in the claims, respectively. The DOE 140 corresponds to a “diffractive optical element” recited in the claims. However, the description of the correspondence between the above claims and the present embodiment is merely an example, and the invention according to the claims is not limited to the present embodiment.

  First, FIG. 1 shows a schematic configuration of an object detection apparatus 1 according to the present embodiment. As shown in FIG. 1, the object detection device 1 includes an information acquisition device 2 and an information processing device 3. The television 4 is controlled by a signal from the information processing device 3.

  The information acquisition device 2 projects infrared light over the entire target area, and receives the reflected light with a CMOS image sensor, whereby the distance to each part of the object existing in the target area (hereinafter, “three-dimensional distance information”). Get). The acquired three-dimensional distance information is sent to the information processing apparatus 3 via the cable 5.

  The information processing device 3 is, for example, a television control controller, a game machine, a personal computer, or the like. The information processing device 3 detects an object in the target area based on the three-dimensional distance information received from the information acquisition device 2, and controls the television 4 based on the detection result.

  For example, the information processing device 3 detects a person based on the received three-dimensional distance information and detects the movement of the person from the change in the three-dimensional distance information. For example, when the information processing device 3 is a television control controller, the information processing device 3 detects the person's gesture from the received three-dimensional distance information and outputs a control signal to the television 4 in accordance with the gesture. The application program to be installed is installed.

  For example, when the information processing device 3 is a game machine, the information processing device 3 detects the person's movement from the received three-dimensional distance information, and displays a character on the television screen according to the detected movement. An application program that operates and changes the game battle situation is installed.

  FIG. 2 is a diagram illustrating the configuration of the information acquisition device 2 and the information processing device 3.

  The information acquisition apparatus 2 includes a projection optical system 100 and a light receiving optical system 200 as a configuration of the optical unit. The projection optical system 100 and the light receiving optical system 200 are arranged in the information acquisition device 2 so as to be aligned in the X-axis direction.

The projection optical system 100 includes a laser light source 110, a collimator lens 120, a mirror 130, and a diffractive optical element (DOE) 140. The light receiving optical system 200 includes an aperture 210, an imaging lens 220, a filter 230, and a CMOS image sensor 240. In addition, the information acquisition apparatus 2 includes a CPU (Central Processing Unit) 21, a laser driving circuit 22, an imaging signal processing circuit 23, an input / output circuit 24, and a memory 25 as a circuit unit.

  The laser light source 110 outputs laser light in a narrow wavelength band having a wavelength of about 830 nm in a direction away from the light receiving optical system 200 (X-axis negative direction). The collimator lens 120 converts the laser light emitted from the laser light source 110 into substantially parallel light.

  The mirror 130 reflects the laser light incident from the collimator lens 120 side in the direction toward the DOE 140 (Z-axis direction).

  The DOE 140 has a diffraction pattern on the incident surface. Due to the diffractive action of this diffraction pattern, the laser light incident on the DOE 140 is converted into laser light having a predetermined dot pattern and irradiated onto the target area.

  The diffraction pattern of the DOE 140 has, for example, a structure in which a step type diffraction grating is formed in a predetermined pattern. The pattern and pitch of the diffraction grating are adjusted so as to convert the laser light that has been made substantially parallel light by the collimator lens 120 into laser light of a dot pattern. The DOE 140 irradiates the target region with the laser beam incident from the mirror 130 as a laser beam having a dot pattern that spreads radially.

  In addition, the configuration in which the projection optical system 100 includes the DOE 140 in order to generate a dot pattern is an example of the configuration according to claim 9.

  The laser light reflected from the target area enters the imaging lens 220 via the aperture 210.

  The aperture 210 stops the light from the outside so as to match the F number of the imaging lens 220. The imaging lens 220 collects the light incident through the aperture 210 on the CMOS image sensor 240. The filter 230 is a bandpass filter that transmits light in the infrared wavelength band including the emission wavelength (about 830 nm) of the laser light source 110 and cuts light in the visible wavelength band.

  The CMOS image sensor 240 receives the light collected by the imaging lens 220 and outputs a signal (charge) corresponding to the amount of received light to the imaging signal processing circuit 23 for each pixel. Here, in the CMOS image sensor 240, the output speed of the signal is increased so that the signal (charge) of the pixel can be output to the imaging signal processing circuit 23 with high response from the light reception in each pixel.

  In the present embodiment, the effective imaging area (area for outputting a signal as a sensor) of the CMOS image sensor 240 has a size of VGA (horizontal 640 pixels × vertical 480 pixels). The imaging effective area of the CMOS image sensor 240 may have other sizes such as an XGA (horizontal 1024 pixels × vertical 768 pixels) size or an SXGA (horizontal 1280 pixels × vertical 1024 pixels) size.

  The CPU 21 controls each unit according to a control program stored in the memory 25. With this control program, the CPU 21 is provided with the functions of a laser control unit 21a for controlling the laser light source 110 and a distance acquisition unit 21b for generating three-dimensional distance information.

  The laser drive circuit 22 drives the laser light source 110 according to a control signal from the CPU 21.

  The imaging signal processing circuit 23 controls the CMOS image sensor 240 to sequentially take in the signal (charge) of each pixel generated by the CMOS image sensor 240 for each line at a predetermined imaging interval. Then, the captured signals are sequentially output to the CPU 21. Based on the signal (imaging signal) supplied from the imaging signal processing circuit 23, the CPU 21 calculates the distance from the information acquisition device 2 to each part of the detection target object by processing by the distance acquisition unit 21b. The input / output circuit 24 controls data communication with the information processing device 3.

  The information processing apparatus 3 includes a CPU 31, an input / output circuit 32, and a memory 33. In addition to the configuration shown in FIG. 2, the information processing apparatus 3 is configured to communicate with the television 4 and to read information stored in an external memory such as a CD-ROM and install it in the memory 33. However, the configuration of these peripheral circuits is not shown for the sake of convenience.

The CPU 31 controls each unit according to a control program (application program) stored in the memory 33. With this control program, the CPU 31 is provided with the functions of an object detection unit 31a for detecting an object in the image and a function control unit 31b for controlling the function of the television 4 according to the movement of the object. . Such a control program is read from a CD-ROM by a drive device (not shown) and installed in the memory 33, for example.

  The object detection unit 31a extracts the shape of the object in the image from the three-dimensional distance information supplied from the information acquisition device 2, and detects the movement of the extracted object shape. The function control unit 31b controls the function of the television 4 as described above based on the detection result by the object detection unit 31a.

  The input / output circuit 32 controls data communication with the information acquisition device 2.

  The projection optical system 100 and the light receiving optical system 200 are installed side by side with a predetermined distance in the X axis direction so that the projection center of the projection optical system 100 and the imaging center of the light receiving optical system 200 are aligned on a straight line parallel to the X axis. Is done. The installation interval between the projection optical system 100 and the light receiving optical system 200 is set according to the distance between the information acquisition device 2 and the reference plane of the target area.

  Next, a method for acquiring three-dimensional distance information by the information acquisition device 2 will be described.

  FIG. 3A is a diagram schematically showing the irradiation state of the laser light on the target region, and FIG. 3B is a diagram schematically showing the light receiving state of the laser light in the CMOS image sensor 240. For convenience, FIG. 3B shows a flat surface (screen) in the target area and a light receiving state when a person is present in front of the screen.

  As shown in FIG. 3A, the projection optical system 100 irradiates a target region with laser light having a dot pattern (hereinafter, the entire laser light having this pattern is referred to as “DP light”). . In FIG. 3A, the light flux region of DP light is indicated by a solid line frame. In the light flux of DP light, dot regions (hereinafter simply referred to as “dots”) generated by the diffraction action by the DOE 140 are scattered according to the dot pattern by the diffraction action by the DOE 140. The dots are generated when the laser light from the laser light source 110 is branched by the DOE 140.

  When a flat surface (screen) and a person are present in the target area, DP light is distributed on the CMOS image sensor 240 as shown in FIG. The light of Dt0 on the target area shown in FIG. 3A enters the position of Dt0 ′ shown in FIG. 3B on the CMOS image sensor 240. An image of a person in front of the screen is taken upside down on the CMOS image sensor 240 in the vertical and horizontal directions.

  4A to 4C are diagrams for explaining a reference pattern setting method used in the distance detection method.

  As shown in FIG. 4A, a flat reflection plane RS perpendicular to the Z-axis direction is disposed at a position at a predetermined distance Ls from the projection optical system 100. The emitted DP light is reflected by the reflection plane RS and enters the CMOS image sensor 240 of the light receiving optical system 200. Thereby, an electrical signal for each pixel in the effective imaging area is output from the CMOS image sensor 240. The output electric signal value (pixel value) for each pixel is developed on the memory 25 of FIG.

  Hereinafter, an image composed of all pixel values obtained by reflection from the reflection plane RS is referred to as a “reference image”, and the reflection plane RS is referred to as a “reference plane”. As shown in FIG. 4B, a “reference pattern region” is set on the standard image. FIG. 4B shows a state in which the light receiving surface is seen through in the positive direction of the Z axis from the back side of the CMOS image sensor 240. The same applies to FIGS. 5A and 5B.

A plurality of segment areas having a predetermined size are set for the reference pattern area set in this way. The size of the segment area is determined in consideration of the contour extraction accuracy of the object based on the obtained distance information, the load of the calculation amount of distance detection for the CPU 21, and the error occurrence rate by the distance detection method described later.

  In the present embodiment, the size of the segment area is set to 15 horizontal pixels × 15 vertical pixels.

  With reference to FIG.4 (c), the segment area | region set to a reference pattern area | region is demonstrated. In FIG. 4C, for the sake of convenience, the size of each segment area is indicated by 9 pixels wide × 9 pixels high, and the center pixel of each segment area is indicated by a cross.

  As shown in FIG. 4C, the segment areas are set such that adjacent segment areas are arranged at intervals of one pixel in the X-axis direction and the Y-axis direction with respect to the reference pattern area. That is, a certain segment area is set at a position shifted by one pixel with respect to a segment area adjacent to the segment area in the X-axis direction and the Y-axis direction. At this time, each segment area is dotted with dots in a unique pattern. The pattern of pixel values in the segment area is different for each segment area in a search range L0 described later.

  Thus, information on the position of the reference pattern area on the CMOS image sensor 240, pixel values (reference patterns) of all pixels included in the reference pattern area, and segment area information set for the reference pattern area are shown in FIG. 2 memory 25. These pieces of information stored in the memory 25 are hereinafter referred to as “reference templates”.

  The CPU 21 in FIG. 2 refers to the reference template when calculating the distance from the projection optical system 100 to each part of the detection target object. When calculating the distance, the CPU 21 calculates the distance to each part of the object based on the shift amount of the dot pattern in each segment area obtained from the reference template.

  For example, as shown in FIG. 4A, when an object is present at a position closer than the distance Ls, DP light (DPn) corresponding to a predetermined segment area Sn on the reference pattern is reflected by the object, and the segment area Sn. It is incident on a different region Sn ′. Since the projection optical system 100 and the light receiving optical system 200 are adjacent to each other in the X-axis direction, the displacement direction of the region Sn ′ with respect to the segment region Sn is parallel to the X-axis. In the case of FIG. 4A, since the object is located at a position closer than the distance Ls, the region Sn 'is displaced in the X-axis positive direction with respect to the segment region Sn. If the object is at a position farther than the distance Ls, the region Sn ′ is displaced in the negative X-axis direction with respect to the segment region Sn.

  Based on the displacement direction and displacement amount of the region Sn ′ with respect to the segment region Sn (pixel displacement amount D shown in FIG. 4A), the projection optical system 100 reaches the portion of the object irradiated with DP light (DPn). The distance Lr is calculated based on the triangulation method using the distance Ls. Similarly, the distance from the projection optical system 100 is calculated for the part of the object corresponding to another segment area. The details of this calculation method are described in, for example, Non-Patent Document 1 (The 19th Annual Conference of the Robotics Society of Japan (September 18-20, 2001) Proceedings, P1279-1280).

In this distance calculation, it is detected to which position the segment area Sn of the reference template has been displaced during actual measurement. This detection is performed by collating the dot pattern obtained from the DP light irradiated onto the CMOS image sensor 240 at the time of actual measurement with the dot pattern included in the segment region Sn. Hereinafter, an image made up of all the pixel values obtained from the DP light irradiated to the imaging effective area on the CMOS image sensor 240 at the time of actual measurement will be referred to as “measured image”. The effective imaging area of the CMOS image sensor 240 at the time of actual measurement is, for example, the size of VGA (horizontal 640 pixels × vertical 480 pixels), as in the case of acquiring the reference image.

  FIGS. 5A to 5C are diagrams for explaining such a distance detection method. FIG. 5A is a diagram showing a reference pattern area set in a standard image on the CMOS image sensor 240, and FIG. 5B is a diagram showing an actually measured image on the CMOS image sensor 240 at the time of actual measurement. FIG. 5C is a diagram for explaining a matching method between the dot pattern of the DP light included in the actually measured image and the dot pattern included in the segment area of the reference template. For convenience, FIGS. 5 (a) and 5 (b) show only a part of the segment areas, and FIG. 5 (c) shows the size of each segment area as horizontal 9 pixels × vertical 9 Shown in pixels.

  When searching for the displacement position at the time of actual measurement of the segment region Si in FIG. 5A, as shown in FIG. 5B, the X axis is centered on the region Si0 at the same position as the segment region Si on the actual measurement image. A range of + α pixels and −α pixels in the direction is set as the search range L0. At the time of search, the segment area Si is sent in the X-axis direction pixel by pixel in the search range L0, and the dot pattern on the segment area Si is compared with the dot pattern on the measured image at each feed position. Hereinafter, a region corresponding to each feed position on the actually measured image is referred to as a “comparison region”. In the search range L0, comparison areas having the same size as the segment area Si are set every other pixel. The search range L0 is set according to the range of distances to be acquired. The wider the range of distances to be acquired, the wider the search range L0.

  In the search range L0 set in this way, while the segment area Si is fed one pixel at a time in the X-axis direction, the matching degree between the dot pattern of the segment area Si and the dot pattern of the comparison area at each feed position is set at each feed position. Desired. The reason why the segment area Si is sent only in the X-axis direction within the search range L0 is that the dot pattern in the segment area is normally displaced only in the X-axis direction during measurement as described above.

  At the time of detecting the matching degree, the difference between the pixel value of each pixel in the segment area Si and the pixel value of the corresponding pixel in the comparison area is obtained. A value Rsad obtained by adding the obtained difference to all the pixels in the comparison region is acquired as a value indicating the similarity.

  For example, as shown in FIG. 5C, when pixels in n columns × m rows are included in one segment area, the pixel values T (i, j) of the pixels in i columns and j rows in the segment area. ) And the pixel value I (i, j) of the pixel in the comparison area i column and j row. Then, the difference is obtained for all the pixels in the segment area, and the value Rsad of the equation shown in FIG. 5C is obtained from the sum of the differences. The smaller the value Rsad, the higher the degree of similarity between the segment area and the comparison area.

  In this way, the value Rsad is obtained for all the comparison regions within the search range L0 for the segment region Si. Then, the comparison area having the minimum obtained value Rsad is detected as the movement area of the segment area Si.

  In the example of FIG. 5B, the dots included in the segment area Si have moved to the position of the comparison area Cj on the measured image. Therefore, in this case, the value Rsad for the comparison area Cj is minimized, and the comparison area Cj is detected as the movement area of the segment area Si. Then, a pixel shift amount in the X-axis direction between the comparison region Cj and the region Si0 located at the same position as the segment region Si is acquired. This pixel shift amount corresponds to the pixel shift amount D shown in FIG. Thereafter, based on this pixel shift amount D, distance information with respect to the segment region Si is acquired based on the triangulation method as described above.

  By the way, when searching for the position of the segment area set on the reference image on the actual measurement image in this way, all the dots in the segment area are dots on the actual measurement image at positions other than the movement position of the segment area. It is necessary to avoid overlapping. If dots overlap at a position other than the movement position of the segment area, the value Rsad at that position becomes small, and the search for the segment area tends to cause an error, and as a result, the accuracy of the distance information may decrease.

  Further, the dots irradiated to the target area need to be set so as to be distributed as uniformly as possible with a preset density.

  As the dot density decreases, the number of dots included in the segment area decreases, and the uniqueness of the dot distribution decreases. On the other hand, when the density of dots increases, the interval between dots becomes narrow, and a plurality of dots are likely to be applied to one pixel on the CMOS image sensor 240. For this reason, the dot pattern irradiated to the target area is set to have a dot density that makes it difficult for a plurality of dots to be applied to one pixel while ensuring the uniqueness of the dots included in the segment area. There is a need.

  If the dots are non-uniform in the target area, the number of dots included in one segment area becomes unstable, and the uniqueness of each segment area varies depending on the number of dots included. Therefore, the dot pattern irradiated to the target area needs to be set so that the dots are distributed as uniformly as possible.

  However, it is difficult to design a dot pattern so as to satisfy such a condition.

  Therefore, in the present embodiment, the dot pattern is configured according to a predetermined rule so that the dot pattern satisfies the above conditions in the target area. Hereinafter, specific configuration examples (Examples 1 to 7) of the dot pattern will be described.

<Example 1>
6A to 6C are diagrams illustrating a configuration example of a dot pattern according to the first embodiment. 6A to 6C show dot patterns that enter the CMOS image sensor 240 when the reference pattern is irradiated with the dot patterns. In this embodiment, for convenience of description, the dot pattern is described in association with the position of the pixel on the CMOS image sensor 240. The squares shown in FIGS. 6A and 6C indicate a region corresponding to one pixel on the CMOS image sensor 240. In FIGS. 6A and 6C, hatched regions indicate regions where dots are present. In the drawings after FIG. 7A, the dot pattern is described in association with the pixels on the CMOS image sensor 240, as in FIGS. 6A and 6C.

  FIG. 6A is a diagram illustrating the configuration of the dot units U0 to U4.

  The dot units U0 to U4 are minimum units when designing a dot pattern. In the present embodiment, the dot units U0 to U4 are set to a size of 4 vertical pixels and 4 horizontal pixels. The dot units U0 to U4 include only one dot at different pixel positions. That is, when the pixel position in the dot units U0 to U4 is expressed as (vertical pixel position, horizontal pixel position), the dot unit U0 includes a dot at the pixel position (1, 1). The dot units U1 to U4 include dots at positions (2, 3), (2, 2), (3, 2), and (3, 3), respectively.

  Hereinafter, for convenience of explanation, unit numbers 0 to 4 are assigned to the dot units U0 to U4, respectively.

  The dot units U0 to U4 correspond to “unit areas” recited in the claims. Further, as shown in FIG. 6A, the configuration in which the dot units U0 to U4 include only one dot is an example of the configuration according to claim 8.

  FIG. 6B is a diagram illustrating an arrangement example of the dot units U0 to U4 on the dot pattern. The numbers shown in FIG. 6B indicate the unit numbers assigned to the dot units U0 to U4. Here, one unit group G is generated by arranging any one of the dot units U0 to U4 in the horizontal direction (X-axis direction) and three in the vertical direction (Y-axis direction).

  The uppermost stage of the unit group G consists of only the dot unit U0 with unit number 0. In the middle part of the unit group G, three types of dot units U0, U1, U3 of unit numbers 0, 1, and 3 are periodically arranged. At the bottom of the unit group G, five types of dot units U0 to U4 of unit numbers 0, 1, 2, 3, and 4 are periodically arranged.

  FIG. 6C is a diagram showing the distribution of dots in the unit group G. In the present embodiment, the unit group G configured as described above is repeatedly arranged in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction) to form a dot pattern. Here, the area of the dot pattern is larger than the size of the effective imaging area of the CMOS image sensor 240. For example, when the effective imaging area of the CMOS image sensor 240 is VGA (640 horizontal pixels × 480 vertical pixels), the dot pattern area is the unit group G (60 horizontal pixels × 12 vertical pixels) shown in FIG. ) Is set to a size such that 12 are arranged in the horizontal direction and 44 are arranged in the vertical direction.

  Thus, when the unit groups G are arranged in the horizontal direction (X-axis direction), one row made up of a series of unit groups arranged in the horizontal direction corresponds to a “row” described in the claims. Further, as shown in FIG. 6B, predetermined dot units are periodically arranged in each row, and the number of types of dot units included in two rows adjacent in the vertical direction (Y-axis direction) is as follows. The different configurations are examples of the configuration described in claim 1. Moreover, as shown in FIG. 6B, a configuration in which combinations of three rows having different numbers of types of dot units are arranged in the vertical direction (Y-axis direction) so as to be adjacent to each other is described in claim 3. It is an example of a structure.

  As can be seen with reference to FIG. 6C, when the dot units U0 to U4 are configured as shown in FIG. 6A, the dots distributed on the dot pattern are separated from each other by two or more pixels.

  Thus, the configuration in which the dot units U0 to U4 are set so that the dots are separated by two or more pixels when the dot units U0 to U4 are combined is an example of the configuration according to claim 6. When the dot units U0 to U4 are configured in this way, it is possible to prevent a plurality of dots from overlapping one pixel on the CMOS image sensor 240, and it is possible to appropriately acquire distance information.

In this embodiment, as described above, since the number of types of dot units included in the uppermost, middle, and lowermost stages of the unit group G is 1, 3, and 5, respectively, the least common multiple of 1, 3, and 5 In the section where the 15 dot units are arranged in the horizontal direction (corresponding to the width of the unit group G in the X-axis direction), the uniqueness of the dots is secured. For example, if an area of 12 pixels in the vertical direction and 12 pixels in the horizontal direction is set in the unit group G, even if this area is shifted in the horizontal direction by one pixel at a time, in a pixel range for 15 units (15 × 4 = 60), a certain position In this case, the dots included in this region do not completely coincide with the dots included in this region at other positions. Thus, in this embodiment, the uniqueness of the dots is ensured in the range of 15 dot units arranged in the horizontal direction (range of 60 pixels in the horizontal direction).

  FIGS. 7A and 7B are diagrams showing the relationship between the dot pattern configured as described above and the segment area described above. 7A and 7B illustrate a case where the upper left corner of the unit group G is positioned at the upper left corner of the imaging effective area of the CMOS image sensor 240. FIG. 7A shows the distribution of dots near the upper left corner of the effective imaging area, and FIG. 7B shows the distribution of dot units near the upper left corner of the effective imaging area.

  As described above, in this embodiment, the uniqueness of dots is ensured in the range of 15 dot units arranged in the horizontal direction (range of 60 pixels in the horizontal direction). Therefore, the dots included in the segment area S1 set in the upper left corner of the effective imaging area of the CMOS image sensor 240 are dots included in other segment areas in a section (60 pixels) in which 15 dot units are arranged in the horizontal direction. And never exactly match. Therefore, when the dot pattern is configured as in this embodiment, the search range L0 shown in FIG. 5B is set to 60 pixels or less.

  In this embodiment, as shown in FIG. 7B, the dot units included in the segment area S1 are dots included in the segment area S61 that is 60 pixels away from the segment area S1 in the horizontal direction (X-axis direction). Matches the unit exactly. Further, the dot units included in the segment area S1 completely coincide with the dot units included in the segment area Sk that is 12 pixels away from the segment area S1 in the downward direction (Y-axis direction).

  In this embodiment, since the repetition cycle of the uppermost dot unit of the unit group G is 1 unit (4 pixels), the pixel range for 15 units constituting the unit group G (15 × 4 = 60) In addition, the dots included in the region of 1 to 4 pixels from the top and the region of 1 to 3 pixels from the bottom of the segment region S1 are 1 to It overlaps with the dots included in the 4-pixel area and the 1-3-pixel area from the bottom. Further, since the repetition period of the middle dot unit of the unit group G is 3 units (12 pixels), the dots included in the area of 5 to 8 pixels from the top of the segment area S1 are 3 in the horizontal direction from the segment area S1. It overlaps with dots included in the 5 to 8 pixel area from the top of the segment area that appears every unit cycle (every 12 pixels).

  Therefore, for example, the segment area S37 appearing at the 36th pixel (3 units × 12 cycles) in the horizontal direction from the segment area S1 is 1-8 from the top with respect to the segment area S1, as shown in FIG. The dots in the pixel area (area surrounded by the broken line) overlap the dots in the area of 1 to 3 pixels (area surrounded by the broken line) from the bottom. However, in this case as well, the segment area S37 can be distinguished from the segment area S1 by the uniqueness in this area because the dot does not overlap the segment area S1 in the area of 9 to 12 pixels from the top.

Further, since the repetition cycle of the lowermost dot unit of the unit group G is 5 units (20 pixels), the dots included in the area of 9 to 12 pixels from the top of the segment area S1 are laterally extended from the segment area S1. It coincides with dots included in the region of 9 to 12 pixels from the top of the segment region appearing every 5 unit cycles (every 20 pixels). Therefore, for example, the segment area S21 appearing at the 20th pixel (5 units × 4 cycles) in the horizontal direction from the segment area S1 is 1 to 4 from the top with respect to the segment area S1, as shown in FIG.
The dots in the pixel area (area surrounded by the broken line) overlap with the dots in the area of 9 to 15 pixels (area surrounded by the broken line) from the top. However, in this case as well, since the segment area S21 is not overlapped with the segment area S1 in the area of 5 to 8 pixels from the top, it can be distinguished from the segment area S1 by the uniqueness in this area.

  As described above, according to this embodiment, since the dot pattern is configured by regularly arranging the five types of dot units U0 to U4, the dot pattern can be easily designed. Further, since the dot pattern is configured by arranging the dot units U0 to U4 including only one dot so as to be adjacent to each other, the distribution of dots on the dot pattern can be made uniform. Further, since the dot density in the dot units U0 to U4 corresponds to the dot density in the dot pattern, the dot pattern density can be easily adjusted by adjusting the number of dots included in the dot units U0 to U4. Can do. In the present embodiment, since the dot for one pixel is set for the dot units U0 to U4 composed of the area of 16 pixels of 4 pixels vertically and 4 pixels horizontally, the dot density on the dot pattern is 1/16. (≈6%).

<Example 2>
8A and 8B are diagrams illustrating a configuration example of a dot pattern according to the second embodiment. FIGS. 8A and 8B correspond to FIGS. 7A and 7B shown for the first embodiment.

  In the first embodiment, in all the unit groups G constituting the dot pattern, the dot unit arranged at the uppermost stage is fixed to the dot unit U0 of unit number 0. On the other hand, in the second embodiment, the dot unit filling the uppermost stage of the unit group G is changed for each unit group arranged in the vertical direction as shown in FIG. That is, in the unit group G arranged at the uppermost part of the dot pattern, the dot unit U0 of unit number 0 is arranged at a period of one unit in the horizontal direction at the uppermost stage, and the unit adjacent to the lower side of the unit group G In the group G, the dot unit U1 of unit number 1 is arranged at the uppermost stage at a cycle of one unit in the horizontal direction. Hereinafter, similarly, every time the arrangement position of the unit group G is shifted downward, the unit number of the dot unit arranged in the uppermost stage is changed to 2, 3, and 4. Then, under the unit group G in which the dot unit U4 with the unit number 4 is arranged at the uppermost stage, the dot unit U0 with the unit number 0 is again arranged at the uppermost stage. Hereinafter, similarly, every time the unit group G is shifted downward, the unit number of the dot unit arranged at the top is 1, 2, 3, 4, 0, 1, 2,. Be changed.

  Therefore, in the present embodiment, as shown in FIG. 8B, the pair of the second row and the third row from the top is repeatedly arranged in the downward direction at intervals of three rows. In this way, a configuration in which a set of two rows adjacent to each other is repeatedly arranged in a downward direction with a predetermined period is an example of a configuration according to claim 2.

  Also in this embodiment, the dot pattern can be easily designed as in the first embodiment. Further, the density of dots on the dot pattern can be easily adjusted to a desired value, and the dots can be uniformly distributed on the dot pattern. However, in this embodiment, the unit number of the dot unit arranged in the uppermost stage of the unit group G is changed every time the arrangement position of the unit group G is shifted downward by one. Compared to 1, the design is slightly more complicated.

<Example 3>
9A to 9C are diagrams illustrating a configuration example of a dot pattern according to the third embodiment. FIG.
FIGS. 9A and 9B correspond to FIGS. 6A and 6B shown for the first embodiment, and FIG. 9C shows FIG. 7A shown for the first embodiment. ).

  In the first embodiment, one type of dot unit U0 is arranged at the uppermost stage of the unit group G. However, in the third embodiment, as shown in FIG. The dot units U0 and U1 are periodically arranged. The configuration of the dot units U0 to U4 shown in FIG. 9A is the same as that of the first embodiment. In FIG. 9B, the right end position of the unit group G in the first embodiment is indicated by the symbol M. In FIG. 9B, a bold frame indicates a unit group G.

  As described above, when two types of dot units U0 and U1 are arranged at the top of the unit group G, the number of types of dot units included in each row constituting the dot pattern is 2 or more in all rows. . This configuration is an example of the configuration described in claim 5.

  As described above, assuming that there are two types of dot units arranged in the uppermost stage of the unit group G, the number of types of dot units included in the uppermost, middle, and lowermost stages of the unit group G is 2 respectively. In the section in which 30 units, which are the least common multiples of 2, 3, and 5, are arranged in the horizontal direction, the uniqueness of the dots is ensured. Therefore, in the case of this configuration example, the search range L0 shown in FIG. 5B can be extended from 60 pixels in Embodiment 1 to 120 pixels.

  Further, when the number of types of dot units arranged in the uppermost stage of the unit group G is two types as in the present embodiment, the repetition cycle of the uppermost dot unit is 2 units (8 pixels). The dots included in the region of 1 to 4 pixels from the top and 1 to 3 pixels from the bottom of the segment region S1 shown in c) are the segment regions that appear every 2 unit periods (every 8 pixels) in the horizontal direction from the segment region S1. It overlaps with the dot contained in the area | region of 1-4 pixels from the top, and 1-3 pixels from the bottom. As described above, in this embodiment, since the repetition cycle of the uppermost dot unit is changed from that in the first embodiment, in the first embodiment, as shown in FIG. In the area of 1 to 4 pixels and the area of 1 to 3 pixels from the bottom, it overlapped with the dots of the segment areas S21 and S37 appearing in the 20th and 36th pixels from the segment area S1, but in this embodiment, in FIG. As shown in (c), the segment area S1 does not overlap the dots of the segment areas S21 and S37 even in the area of 1 to 4 pixels from the top and the area of 1 to 3 pixels from the bottom. Therefore, according to the present embodiment, the uniqueness of the segment area S1 can be enhanced as compared with the first embodiment.

  In the segment area S61 that appears at the 60th pixel on the right side of the segment area S1, dots in the area of 5 to 12 pixels from the top overlap the segment area S1. However, in this case as well, since the segment area S61 is not overlapped with the segment area S1 in the area of 1 to 4 pixels from the top and the area from 1 to 3 from the bottom, the segment area S1 is unique due to the uniqueness in this area. Can be distinguished from Similarly, in the segment area set to the left of M in FIG. 9B, the dot overlaps with the segment area appearing at the 60th pixel in the right direction from itself, in the area of 5 to 12 pixels from the top. Since the dots do not overlap in the 1 to 4 pixel area and the 1 to 3 area from below, the uniqueness is ensured by this area.

  Also in this embodiment, the dot pattern can be easily designed as in the first and second embodiments. Further, the density of dots on the dot pattern can be easily adjusted to a desired value, and the dots can be uniformly distributed on the dot pattern. Further, as described above, the search range L0 can be doubled as compared with the first and second embodiments, and the uniqueness of the segment area can be further improved.

  In this embodiment, as shown in FIG. 9B, the number of types of dot units included in one row is not an integral multiple of the number of types of dot units included in other rows. A dot pattern is formed. This configuration is an example of a configuration described in claim 4. In the present embodiment, as shown in FIG. 9B, a set of three rows arranged vertically is repeatedly arranged in the vertical direction (Y-axis direction) so as to be adjacent to each other. This configuration is an example of a configuration described in claim 3. Furthermore, in this embodiment, as shown in FIG. 9B, the number of types of dot units included in each row is 2 or more in all rows. This configuration is an example of the configuration described in claim 5.

<Example 4>
10A to 10C are diagrams illustrating a configuration example of a dot pattern according to the fourth embodiment. FIGS. 10A to 10C correspond to FIGS. 9A to 9C shown for the third embodiment.

  In the third embodiment, in all the unit groups G constituting the dot pattern, the dot unit arranged at the uppermost stage is fixed to the dot units U0 and U1 with unit numbers 0 and 1. On the other hand, in the fourth embodiment, the dot unit filling the uppermost stage of the unit group G is changed for each unit group arranged in the vertical direction as shown in FIG. That is, in the unit group G arranged at the uppermost part of the dot pattern, the dot units U0 and U1 of unit numbers 0 and 1 are arranged at a period of two units in the horizontal direction at the uppermost stage. In the unit group G adjacent to the dot unit, the dot units U0 and U2 with unit numbers 0 and 2 are arranged at the uppermost stage in a cycle of 2 units in the horizontal direction. Hereinafter, similarly, every time the unit group G is shifted downward, the unit numbers of the dot units arranged at the uppermost level are (0, 3), (0, 4), (0, 1). ), (0, 2), (0, 3).

  Also in the present embodiment, the same effect as in the third embodiment can be achieved. However, in this embodiment, the unit number of the dot unit arranged in the uppermost stage of the unit group G is changed every time the arrangement position of the unit group G is shifted downward by one. Compared to 3, the design is slightly more complicated.

  In this embodiment, as shown in FIG. 10B, the number of types of dot units included in one row is not an integral multiple of the number of types of dot units included in other rows. A dot pattern is formed. This configuration is an example of a configuration described in claim 4. Further, in this embodiment, as shown in FIG. 10B, a set of the second row and the third row from the top is repeatedly arranged in the vertical direction at intervals of 3 units. This configuration is an example of the configuration described in claim 2. Furthermore, in this embodiment, as shown in FIG. 10B, the number of types of dot units included in each row is 2 or more in all rows. This configuration is an example of the configuration described in claim 5.

<Example 5>
FIGS. 11A to 11C are diagrams illustrating a configuration example of a dot pattern according to the fifth embodiment. 11 (a) and 11 (b) correspond to FIGS. 6 (a) and 6 (b) shown for the first embodiment, respectively, and FIG. 11 (c) shows the first embodiment. This corresponds to FIG.

As shown in FIG. 11A, in this embodiment, the dot units U11 to U16 are set to have a size of 5 pixels vertically and 4 pixels horizontally. In addition, there are six types of dot units U11 to U16 used in the configuration of the dot pattern. Further, the dot units U11 to U16 are configured so that dots are not arranged at the pixel positions on the outermost periphery of the dot unit.

  The dot units U11 to U16 correspond to “unit areas” recited in the claims. As shown in FIG. 11A, a configuration in which no dots are arranged at the outermost pixel positions of the dot units U11 to U16 is an example of a configuration according to claim 7. Further, as shown in FIG. 11A, the configuration in which only one dot is included in the dot units U <b> 11 to U <b> 16 is an example of the configuration according to claim 8.

  As shown in FIG. 11B, in the present embodiment, only the dot unit U15 of unit number 5 is arranged at the top of the unit group G. In the middle of the unit group G, six types of dot units U11 to U16 having unit numbers 1, 2, 3, 4, 5, and 6 are periodically arranged. At the bottom of the unit group G, five types of dot units U5, U4, U3, U2, and U1 with unit numbers 5, 4, 3, 2, and 1 are periodically arranged.

  FIG. 11C is a diagram showing the distribution of dots in the unit group G. Also in the present embodiment, as in the first embodiment, the unit group G is repeatedly arranged in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction) to form a dot pattern.

  In the present embodiment, the unit group G is the least common multiple of 1, 6, and 5 because the number of types of dot units included in the uppermost, middle, and lowermost stages is 1, 6, and 5, respectively. In the section in which the units are arranged in the horizontal direction, the uniqueness of the dots is ensured. Therefore, in the case of the present embodiment, the search range L0 shown in FIG. 5B is set to 120 pixels or less.

  In this embodiment, the repetition cycle of the uppermost dot unit of the unit group G is 1 unit (4 pixels), and the repetition cycle of the middle dot unit is 6 units (24 pixels). The dots included in the region of 1 to 10 pixels from the top of the region S1 are dots included in the region of 1 to 10 pixels from the top of the segment region that appears every six unit periods (every 24 pixels) in the horizontal direction from the segment region S1. And overlap. Therefore, for example, the segment area S49 appearing at the 48th pixel (6 units × 2 cycles) in the horizontal direction from the segment area S1 is 1-10 from the top with respect to the segment area S1, as shown in FIG. Dots in a pixel region (region surrounded by a broken line) overlap. However, in this case as well, the segment area S49 can be distinguished from the segment area S1 by the uniqueness in this area because the dot does not overlap the segment area S1 in the area of 11 to 15 pixels from the top.

  Further, since the repetition cycle of the lowermost dot unit of the unit group G is 5 units (20 pixels), the dots included in the region of 11 to 15 pixels from the top of the segment region S1 are laterally moved from the segment region S1. It coincides with dots included in the region of 11 to 15 pixels from the top of the segment region appearing every 5 unit cycles (every 20 pixels). Therefore, for example, the segment area S21 appearing at the 20th pixel (5 units × 4 periods) in the horizontal direction from the segment area S1 is 1-5 from the top with respect to the segment area S1, as shown in FIG. The dots in the pixel area (area surrounded by the broken line) overlap the dots in the area of 11 to 15 pixels (area surrounded by the broken line) from the top. However, in this case as well, since the segment area S21 is not overlapped with the segment area S1 in the area of 6 to 10 pixels from the top, it can be distinguished from the segment area S1 by the uniqueness in this area.

  Also in this embodiment, the dot pattern can be easily designed as in the first embodiment. Further, the density of dots on the dot pattern can be easily adjusted to a desired value, and the dots can be uniformly distributed on the dot pattern. Further, as described above, the search range L0 can be doubled compared to the first embodiment.

  In the present embodiment, as shown in FIG. 11B, a set of three rows arranged vertically is repeatedly arranged in the vertical direction (Y-axis direction) so as to be adjacent to each other. This configuration is an example of a configuration described in claim 3.

<Example 6>
12A to 12C are diagrams illustrating a configuration example of a dot pattern according to the sixth embodiment. FIGS. 12A to 12C correspond to FIGS. 11A to 11C shown for the fifth embodiment.

  In this embodiment, compared to the fifth embodiment, the types of dot units arranged at the uppermost stage of the unit group G are changed to two types. That is, as shown in FIG. 12B, in this embodiment, the dot units U15 and U16 with unit numbers 5 and 6 are periodically arranged at the uppermost stage of the unit group G.

  In this embodiment, the numbers of types of dot units included in the uppermost, middle, and lowermost stages of the unit group G are 2, 6, and 5, respectively. However, since the least common multiple of 2, 6, and 5 is 30, similarly to the fifth embodiment, the uniqueness of the dots is ensured in the section where 30 units are arranged in the horizontal direction. Therefore, in the present embodiment, the search range L0 shown in FIG. 5B is set to 120 pixels or less, as in the fifth embodiment.

  However, in this embodiment, since the type of the uppermost dot unit of the unit group G is changed to two types, as shown in FIG. 12C, the dots in the area of 1 to 5 pixels from the top of the segment area S21. Does not overlap with the dots in the segment area S1. For this reason, in a present Example, the uniqueness of a segment area | region can be improved compared with the said Example 5. FIG.

  In this embodiment, as shown in FIG. 12B, a set of three rows arranged vertically is repeatedly arranged in the vertical direction (Y-axis direction) so as to be adjacent to each other. This configuration is an example of a configuration described in claim 3. Furthermore, in this embodiment, as shown in FIG. 12B, the number of types of dot units included in each row is 2 or more in all rows. This configuration is an example of the configuration described in claim 5.

<Example 7>
13A to 13C are diagrams illustrating a configuration example of a dot pattern according to the seventh embodiment. FIGS. 13A to 13C correspond to FIGS. 11A to 11C shown for the fifth embodiment.

  In the present embodiment, compared to the fifth embodiment, the types of dot units arranged at the uppermost stage of the unit group G are changed to four types. That is, as shown in FIG. 13B, in this embodiment, the dot units U15, U16, U12, and U11 having unit numbers 5, 6, 2, and 1 are periodically arranged in the uppermost stage of the unit group G. ing.

  In this embodiment, the numbers of types of dot units included in the uppermost, middle, and lowermost stages of the unit group G are 4, 6, and 5, respectively. Therefore, the uniqueness of the dots is ensured in the section in which 120 units, which are the least common multiples of 4, 6, and 5, are arranged in the horizontal direction. Therefore, in this embodiment, the search range L0 shown in FIG. 5B is extended to 480 pixels (4 pixels × 120 units).

In this embodiment, as shown in FIG. 13B, the number of types of dot units included in one row is not an integral multiple of the number of types of dot units included in other rows. A dot pattern is formed. This configuration is an example of a configuration described in claim 4. In this embodiment, as shown in FIG. 13B, a set of three rows arranged vertically is repeatedly arranged in the vertical direction (Y-axis direction) so as to be adjacent to each other. This configuration is an example of a configuration described in claim 3. Furthermore, in this embodiment, as shown in FIG. 13B, the number of types of dot units included in each row is 2 or more in all rows. This configuration is an example of the configuration described in claim 5.

  As mentioned above, although embodiment of this invention and Examples 1-7 were demonstrated, this invention is not restrict | limited to the said embodiment and Examples 1-7 at all, and Embodiment of this invention In addition to the above, various modifications can be made.

  For example, in the first to seventh embodiments, an example in which the dot units U0 to U4 and U11 to U16 include only one dot is shown, but the number of dots included in the dot unit is not limited to one. Depending on the dot density on the dot pattern, it can be appropriately changed. Further, the size of the dot unit is not limited to that shown in the first to seventh embodiments, and can be appropriately changed according to the density of dots on the dot pattern.

  In the above embodiment, the distance information is obtained using the triangulation method. However, the distance information acquisition method is not limited to this. For example, the pixel described with reference to FIG. The deviation amount D may be acquired as it is as distance information.

  In the above embodiment, the segment area set in the reference image is searched on the actual measurement image. However, the segment area corresponding to the dot pattern of the area set on the actual measurement image is searched on the reference image. You may make it search with.

  Further, in the above embodiment, the filter 230 is disposed to remove light in a wavelength band other than the wavelength band of the laser light irradiated to the target region. For example, light other than the laser light irradiated to the target region is used. In the case where a circuit configuration for removing the signal component from the signal output from the CMOS image sensor 240 is arranged, the filter 230 may be omitted. In the above embodiment, the CMOS image sensor 240 is used as the light receiving element, but a CCD image sensor may be used instead. Furthermore, the configurations of the projection optical system 100 and the light receiving optical system 200 can be changed as appropriate.

  In addition, the embodiment of the present invention can be variously modified as appropriate within the scope of the technical idea shown in the claims.

DESCRIPTION OF SYMBOLS 1 ... Object detection apparatus 2 ... Information acquisition apparatus 3 ... Information processing apparatus 21b ... Distance acquisition part 100 ... Projection optical system 110 ... Laser light source 200 ... Light reception optical system 240 ... CMOS image sensor (image sensor)
140 ... DOE (diffractive optical element)
U0 to U4 ... Dot unit (unit area)
U11 to U16 ... dot unit (unit area)

Claims (10)

A projection optical system that projects laser light emitted from a laser light source onto a target area with a predetermined dot pattern;
A light receiving optical system that is arranged in a first direction with respect to the projection optical system, and that images the target area by an image sensor;
A distance acquisition unit that acquires distance information regarding a distance to an object included in the target area based on an actual measurement image captured by the image sensor at the time of actual measurement;
The dot pattern includes the same number of dots, and any of a plurality of unit regions having different distributions is periodically arranged in the first direction, and further included in a row in the first direction. The number of types of unit regions and the number of types of unit regions included in a row adjacent to the row in a second direction perpendicular to the first direction are different from each other. ,
An information acquisition apparatus characterized by that. The information acquisition device according to claim 1,
The dot pattern is configured such that combinations of a plurality of rows adjacent to each other and having different numbers of types of unit regions included in the dot pattern are periodically arranged in the second direction. A characteristic information acquisition device. The information acquisition device according to claim 2,
The dot pattern is configured such that a combination of the plurality of rows is adjacent in the second direction.
An information acquisition apparatus characterized by that. In the information acquisition device according to claim 2 or 3,
The rows included in the combination are configured such that the number of types of unit regions included in one row is not an integral multiple of the number of types of unit regions included in another row.
An information acquisition apparatus characterized by that. In the information acquisition device according to any one of claims 1 to 4,
In the dot pattern, the number of types of the unit regions included in the row is 2 or more in all the rows.
An information acquisition apparatus characterized by that. In the information acquisition device according to any one of claims 1 to 5,
The unit regions are configured such that dots are separated by two or more pixels on the image sensor when arbitrarily combined so as to be adjacent to each other.
An information acquisition apparatus characterized by that. The information acquisition apparatus according to claim 6,
The unit area is configured such that no dot is included in the outermost pixel position in the unit area on the image sensor.
An information acquisition apparatus characterized by that. In the information acquisition device according to any one of claims 1 to 7,
The unit area includes only one dot,
An information acquisition apparatus characterized by that. In the information acquisition device according to any one of claims 1 to 8,
The projection optical system includes a diffractive optical element that generates the dot pattern by diffractive action,
An information acquisition apparatus characterized by that. An information acquisition device according to any one of claims 1 to 9,
An object detection unit that detects a predetermined target object based on the distance information,
An object detection apparatus characterized by that.

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