JP2013011511A - Object detection device and information acquisition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information acquisition device capable of performing proper control of a light amount of a laser source by using a spectroscopic element with high reproductivity of a transmission factor and an object detection device having the information acquisition device.SOLUTION: The information acquisition device 1 includes a light-emitting device 10 and a light-receiving device 20. The light-emitting device 10 includes a laser source 110, a collimator lens 120, a leakage mirror 130, a DOE 140 for converting a laser beam reflected by the leakage mirror 130 into a laser beam having a dot pattern, a FMD 160 for receiving the laser beams having passed through the leakage mirror 130 and outputting a detection signal corresponding to the received light amount, a filter 150 arranged between the leakage mirror 130 and the FMD 160 for attenuating the light amount of the laser beam having passed through the leakage mirror 130 and an APC control part 21b for controlling an emitted light amount of the laser source 110 on the basis of the detection signal of the FMD 160.

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. Various types of distance image sensors are known.

  In a distance image sensor of a type that irradiates a target region with laser light having a predetermined dot pattern, reflected light from the target region of laser light having a dot pattern is received by a light receiving element. Based on the light receiving position of the dot on the light receiving element, the distance to each part of the detection target object (irradiation position of each dot on the detection target object) is detected using triangulation (for example, non-patent) Reference 1).

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

  In the object detection apparatus having the above configuration, a laser light source, a collimator lens, and a diffractive optical element are used as an optical system for projecting a dot pattern laser beam. Since the laser light source changes the amount of emitted light due to heat generation or aging deterioration, it is necessary to monitor the output of the laser light and perform APC (Auto Power Control) control so as to obtain a desired light output level.

  As a method for performing APC control, a so-called front monitor configuration in which a spectroscopic element is provided in the laser beam emission direction and a part of the laser beam is transmitted and guided to the photodetector can be used. In the object detection device having the above-described configuration, a high-power laser light source is used to project a laser beam having a dot pattern onto a far target region. In this case, if the transmittance of the spectroscopic element is not sufficiently small, the detection signal of the photodetector is saturated, which may adversely affect APC control. However, it is difficult to manufacture a spectroscopic element having a very low transmittance with good reproducibility.

  The present invention has been made to solve such a problem, and includes an information acquisition apparatus capable of appropriately controlling the light amount of a laser light source while using a spectroscopic element having high reproducibility of transmittance, and the information acquisition apparatus. An object of the present invention is to provide an object detection device.

A 1st aspect of this invention is related with the information acquisition apparatus which acquires the information of a target area | region using light. The information acquisition device according to the present aspect is arranged so that a light emitting device that projects a laser beam with a predetermined dot pattern on a target area, and arranged side by side by a predetermined distance from the light emitting device, the target area And a light receiving device for imaging. The light emitting device includes: a laser light source that emits laser light having a predetermined wavelength; a collimator lens that converts the laser light emitted from the laser light source into parallel light; and a spectroscopic device that branches the laser light that has passed through the collimator lens. An element, a diffractive optical element that converts the first laser light dispersed by the spectroscopic element into laser light having a predetermined dot pattern in the target area, and projects the laser light on the target area; A photodetector that receives two laser beams and outputs a detection signal corresponding to the amount of received light; and the second laser that is disposed between the spectroscopic element and the photodetector and reaches the photodetector. A light amount adjusting member that attenuates the amount of light; and a laser control unit that controls the light emission amount of the laser light source based on the detection signal of the photodetector.

  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.

  ADVANTAGE OF THE INVENTION According to this invention, the information acquisition apparatus which can control the light quantity of a laser light source appropriately, and the object detection apparatus carrying this can be provided, using the spectroscopic element with high reproducibility of the transmittance | permeability.

  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 which shows the disassembled perspective view of the light-emitting device which concerns on embodiment. It is a figure which shows the assembly process of the information acquisition apparatus which concerns on embodiment. It is a figure which shows the assembly process of the information acquisition apparatus which concerns on embodiment. It is a figure which shows the structure of the information acquisition apparatus which concerns on embodiment. It is a flowchart which shows APC control of the information acquisition apparatus which concerns on embodiment. It is a figure which shows the structure of the information acquisition apparatus of another modification.

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, an information acquisition device of a type that irradiates a target area with laser light having a predetermined dot pattern is exemplified.

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

  The information acquisition device 1 projects infrared light over the entire target area and receives the reflected light with a CMOS image sensor, whereby the distance between each part of the object in the target area (hereinafter referred to as “three-dimensional distance information”). To get. The acquired three-dimensional distance information is sent to the information processing apparatus 2 via the cable 4.

  The information processing apparatus 2 is, for example, a television control controller, a game machine, a personal computer, or the like. The information processing device 2 detects an object in the target area based on the three-dimensional distance information received from the information acquisition device 1, and controls the television 3 based on the detection result.

  For example, the information processing apparatus 2 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 2 is a television control controller, the information processing device 2 detects the person's gesture from the received three-dimensional distance information, and outputs a control signal to the television 3 in accordance with the gesture. The application program to be installed is installed. In this case, the user can cause the television 3 to execute a predetermined function such as channel switching or volume up / down by making a predetermined gesture while watching the television 3.

  Further, for example, when the information processing device 2 is a game machine, the information processing device 2 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. In this case, the user can experience a sense of realism in which he / she plays a game as a character on the television screen by making a predetermined movement while watching the television 3.

  FIG. 2 is a diagram illustrating configurations of the information acquisition device 1 and the information processing device 2.

  The information acquisition apparatus 1 includes a projection optical system 100 and a light receiving optical system 200 as a configuration of an optical unit. The projection optical system 100 and the light receiving optical system 200 are arranged in the information acquisition apparatus 1 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 leakage mirror 130, a diffractive optical element (DOE) 140, a filter 150, and an FMD (Front Monitor Diode) 160. . 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 1 includes a CPU (Central Processing Unit) 21, a laser driving circuit 22, a PD signal processing circuit 23, an imaging signal processing circuit 24, an input / output circuit 25, and a circuit unit. A memory 26 is provided.

  The laser light source 110 outputs laser light in a narrow wavelength band with a wavelength of about 830 nm in a direction away from the light receiving optical system 200 (X-axis positive direction). The collimator lens 120 converts the laser light emitted from the laser light source 110 into light slightly spread from parallel light (hereinafter simply referred to as “parallel light”).

  The leakage mirror 130 is formed of a multilayer film of dielectric thin films, and the number of layers and the thickness of the film are designed so that the reflectance is slightly lower than 100% and the transmittance is several steps smaller than the reflectance. The leakage mirror 130 has a certain degree of transmittance (for example, a transmittance of 4%) so that the reproducibility of the reflection / transmittance is ensured in the manufacturing process. The leakage mirror 130 reflects most of the laser light incident from the collimator lens 120 side in the direction toward the DOE 140 (Z-axis direction) and transmits the remaining part in the direction toward the FMD 160 (X-axis direction).

  The DOE 140 has a diffraction pattern on the incident surface. Due to the diffraction effect of the diffraction pattern, the laser light incident on the DOE 140 is converted into a dot pattern laser light and irradiated onto the target region. The diffraction pattern has, for example, a structure in which a step type diffraction hologram is formed in a predetermined pattern. The diffraction hologram is adjusted in pattern and pitch so as to convert the laser light converted into 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 leakage mirror 130 as a laser beam having a dot pattern that spreads radially. The size of each dot in the dot pattern depends on the beam size of the laser light when entering the DOE 140. Laser light (0th order light) that is not diffracted by the DOE 140 passes through the DOE 140 and travels straight.

  The filter 150 is made of a material that absorbs light in the wavelength band of the laser light emitted from the laser light source 110. For example, the filter 150 is formed of a material obtained by mixing a resin material with an organic dye having a characteristic of absorbing infrared light, such as a cyanine dye or a methine dye. The filter 150 attenuates the amount of laser light transmitted through the leakage mirror 130 to about 1/3.

  The FMD 160 receives the laser light attenuated by the filter 150 and outputs an electrical signal corresponding to the amount of received light. The FMD 160 includes a light amount of about 1% of the laser light source 110 in a detectable range.

  The detailed configurations of the projection optical system 100 and the light receiving optical system 200 will be described later with reference to FIGS.

  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 an IR filter (Infrared Filter) that transmits light in the infrared wavelength band including the emission wavelength (about 830 nm) of the laser light source 110 and cuts the wavelength band of visible light.

  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 24 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 24 with high response from light reception in each pixel.

  The CPU 21 controls each unit according to a control program stored in the memory 26. With this control program, the CPU 21 controls the laser light source 110 and a so-called APC (Auto Power Control) that automatically controls the light amount of the laser light source 110 in accordance with the signal amount output from the FMD 160. ) Functions of an APC control unit 21b that performs control and a distance calculation unit 21c for generating three-dimensional distance information are provided.

  The laser drive circuit 22 drives the laser light source 110 according to a control signal from the CPU 21. The PD signal processing circuit 23 amplifies and digitizes the voltage signal corresponding to the amount of received light output from the FMD 160 and outputs it to the CPU 21. Based on the signal supplied from the PD signal processing circuit 23, the CPU 21 determines to amplify or decrease the light amount of the laser light source 110 by processing by the APC control unit 21 b. When the APC control unit 21 b determines that the light amount of the laser light source 110 needs to be changed, the laser control unit 21 a transmits a control signal for changing the light emission amount of the laser light source 110 to the laser driving circuit 22. The processing related to APC control will be described later with reference to FIG.

The imaging signal processing circuit 24 controls the CMOS image sensor 240 and sequentially takes in the signal (charge) of each pixel generated by the CMOS image sensor 240 for each line. Then, the captured signals are sequentially output to the CPU 21. Based on the signal (imaging signal) supplied from the imaging signal processing circuit 24, the CPU 21 calculates the distance from the information acquisition device 1 to each part of the detection target by processing by the distance calculation unit 21c. The input / output circuit 25 controls data communication with the information processing apparatus 2.

  The information processing apparatus 2 includes a CPU 31, an input / output circuit 32, and a memory 33. In addition to the configuration shown in the figure, the information processing apparatus 2 is configured to communicate with the television 3, 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 such a control program, the CPU 31 is provided with the function of the object detection unit 31a for detecting an object in the image. Such a control program is read from a CD-ROM by a drive device (not shown) and installed in the memory 33, for example.

  For example, when the control program is a game program, the object detection unit 31a detects a person in the image and its movement from the three-dimensional distance information supplied from the information acquisition device 1. Then, a process for operating the character on the television screen according to the detected movement is executed by the control program.

  When the control program is a program for controlling the function of the television 3, the object detection unit 31 a detects a person in the image and its movement (gesture) from the three-dimensional distance information supplied from the information acquisition device 1. To do. Then, processing for controlling functions (channel switching, volume adjustment, etc.) of the television 3 is executed by the control program in accordance with the detected movement (gesture).

  The input / output circuit 32 controls data communication with the information acquisition device 1.

  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 the sake of convenience, FIG. 6B shows a light receiving state when a flat surface (screen) exists in the target area.

  From the projection optical system 100, laser light having a dot pattern (hereinafter, the entire laser light having this pattern is referred to as “DP light”) is irradiated onto the target area. In FIG. 5A, 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”) in which the intensity of the laser light is increased by the diffraction action by the DOE 140 are scattered according to the dot pattern by the diffraction action by the DOE 140.

  In FIG. 3A, for convenience, the light beam of DP light is divided into a plurality of segment regions arranged in a matrix. In each segment area, dots are scattered in a unique pattern. The dot dot pattern in one segment area is different from the dot dot pattern in all other segment areas. As a result, each segment area can be distinguished from all other segment areas with a dot dot pattern.

When a flat surface (screen) exists in the target area, the segment areas of DP light reflected thereby are distributed in a matrix on the CMOS image sensor 240 as shown in FIG. For example, the light in the segment area S0 on the target area shown in FIG. 5A is reflected on the segment area Sp shown in FIG.
Is incident on. In FIG. 3B as well, the light flux region of DP light is indicated by a solid frame, and for convenience, the light beam of DP light is divided into a plurality of segment regions arranged in a matrix.

  In the distance calculation unit 21c, the position of each segment area on the CMOS image sensor 240 is detected, and the position corresponding to each segment area of the detection target object based on the triangulation method from the detected position of each segment area. The distance to is detected. The details of such a detection 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).

  Incidentally, as shown in FIG. 2, when a part of the laser light emitted from the laser light source 110 is transmitted by the leakage mirror 130 and guided to the FMD 160, a photodetector for back monitoring is provided in the CAN of the laser light source 110. Even if it is not arranged, the light quantity of the laser light source 110 can be monitored by the FMD 160.

  However, it is difficult to manufacture the leakage mirror 130 with a very low transmittance (for example, a transmittance of about 1%) with good reproducibility. Further, the laser light source 110 uses high-power laser light to project the laser light to a far target area. Therefore, when the light quantity of the laser beam incident on the FMD 160 is adjusted only by the leakage mirror 130 whose transmittance reproducibility is unstable, the transmittance of the used leakage mirror 130 is larger than a target value (for example, approximately 1%). Is too high, the detection signal output from the FMD 160 is saturated, making it difficult to control the light amount of the laser light source 110.

  Therefore, in the present embodiment, a filter is used as a light amount adjusting member for laser light in the optical path from the leakage mirror 130 to the FMD 160 while using the leakage mirror 130 with a slightly high transmittance that ensures reproducibility of the transmittance. 150 is arranged.

  FIG. 4 is an exploded perspective view showing a configuration example of the light emitting device 10 according to the present embodiment. The light emitting device 10 is a device in which the projection optical system 100 in FIG. 2 is unitized together with other components. FIG. 4 shows the front, rear, left, right, and up and down directions along with the XYZ axes shown in FIG. The vertical direction is parallel to the Z-axis direction, the front-rear direction is parallel to the Y-axis direction, and the left-right direction is parallel to the X-axis direction.

  Referring to FIG. 4, light emitting device 10 includes laser holder 111, lens holder 121, in addition to laser light source 110, collimator lens 120, leakage mirror 130, DOE 140, filter 150, and FMD 160 described above. The DOE holding spring 141, the FMD circuit board 161, the temperature detection circuit board 162, the housing 170, and the lens holder holding spring 180 are provided.

  As illustrated, the laser light source 110 includes a base 110a and a CAN 110b. The base 110a has a circular outline with a part of the outer periphery cut out when viewed from the front.

The laser holder 111 is a frame member having a square outline in a front view and having a circular opening 111a formed at the center. The opening 111a penetrates the laser holder 111 in the left-right direction, and has a configuration in which two cylindrical holes having different diameters are arranged on the same axis. The diameter of the right hole of the opening 111a is larger than the diameter of the left hole, and a ring-shaped step is formed at the boundary where the diameter changes. The diameter of the right hole of the opening 111 a is slightly larger than the diameter of the base 110 a of the laser light source 110. The laser light source 110 is positioned with respect to the laser holder 111 by fitting the base 110a into the opening 111a from the right side until the left surface of the base 110a of the laser light source 110 contacts the step in the opening 111a. In this state, an adhesive is injected into a cutout on the outer periphery of the base 110 a, and the laser light source 110 is bonded and fixed to the laser holder 111.

  The lens holder 121 has a substantially circular outline in a front view, and is made of a frame member having an opening 121a formed at the center. The opening 121a penetrates the lens holder 121 in the left-right direction, and has a configuration in which two cylindrical holes having different diameters are arranged on the same axis. The diameter of the right hole of the opening 121a is smaller than the diameter of the left hole, and a ring-shaped step is formed at the boundary where the diameter changes. The diameter of the right hole of the opening 121a is slightly smaller than the diameter of the collimator lens 120. The collimator lens 120 is positioned with respect to the lens holder 121 by fitting the collimator lens 120 into the opening 121a from the left side until the right side of the collimator lens 120 contacts the step in the opening 121a. In this state, the collimator lens 120 is bonded and fixed to the lens holder 121.

  Two grooves are formed on the side surfaces of the lens holder 121 for allowing an adhesive to flow in when the collimator lens 120 and the lens holder 121 are bonded and fixed.

  In the center of the DOE holding spring 141, an opening 141a for guiding the laser beam to the target area is formed. The DOE 140 is fitted into the DOE holding spring 141 from below the DOE holding spring 141 and is fixedly bonded. Further, the DOE holding spring 141 is formed with a flange 141 b for fixing the DOE holding spring 141 to the housing 170 on the front and rear side surfaces.

  The filter 150 has a flat plate shape with a constant thickness. As described above, the filter 150 is made of a resin material containing a dye or the like that absorbs infrared light, and has a shape that is thinner than other optical members (for example, about 0.1 mm).

  The FMD circuit board 161 is a circuit board on which the FMD 160 and the capacitor 161a are mounted. The PD signal processing circuit 23 shown in FIG. 2 is mounted on the FMD circuit board 161, and an amplification circuit that amplifies the electrical signal output from the FMD 160, an A / D conversion circuit that performs digital conversion, and the like are mounted. Further, on the FMD circuit board 161, a circuit board on the subsequent stage on which the CPU 21 and the like are mounted and an FPC (Flexible Printed Circuit) 161b for electrical connection with the laser light source 110 are arranged so as to extend from the rear to the front. . The capacitor 161a reduces electrical noise generated on the FMD circuit board 161. The temperature detection circuit board 162 includes a thermistor and detects the temperature of the laser light source 110.

  The housing 170 is composed of a bottomed frame member having a rectangular outline in a top view. The housing 170 has a symmetrical shape in the front-rear direction with respect to a plane parallel to the XZ plane.

  On the inner left side surface of the housing 170, two mirror mounting portions 170a inclined by 45 ° in the in-plane direction of the XZ plane are formed side by side in the front-rear direction. Further, on the left side of the mirror mounting portion 170a, a groove 170b for mounting the FMD circuit board 161 and an FMD mounting portion 170c are formed. Further, a filter mounting portion 170d for mounting the filter 150 is formed on the left side of the FMD mounting portion 170c.

  A U-shaped opening 170e is formed on the right side surface of the housing 170. The width of the opening 170e in the front-rear direction is larger than the diameter of the CAN 110b of the laser light source 110.

A pair of inclined surfaces 170f facing each other are formed at the lower ends of the two inner side surfaces of the housing 170 in the front-rear direction. The two inclined surfaces 170f are inclined by the same angle downward with respect to a plane parallel to the XY plane. When the lens holder 121 is placed on the two inclined surfaces 170f, the displacement of the lens holder 121 is restricted in the Y-axis direction (front-rear direction).

  On the side surface of the housing 170, a hole 170g for mounting the flange 141b of the DOE pressing spring 141 and a hole 170h for mounting a flange 180b of the lens holder pressing spring 180 described later are formed. Further, a screw hole 170i for fixing the housing 170 to a base plate 300 described later is formed on the bottom surface near the center of the housing 170.

  The lens holder pressing spring 180 is a leaf spring having a spring property, and has a stepped portion 180a one step lower in the center. The lens holder holding spring 180 has a symmetrical shape in the front-rear direction. The lens holder pressing spring 180 is formed with two flange portions 180b for fixing the lens holder pressing spring 180 to the housing 170 from above.

  In assembling the light emitting device 10, first, in FIG. 4, the leakage mirror 130 is mounted on the mirror mounting portion 170 a in the housing 170. Accordingly, the leakage mirror 130 is installed in the housing 170 so as to have an inclination of 45 degrees in the in-plane direction of the XZ plane with respect to the XY plane.

  Next, the lens holder 121 on which the collimator lens 120 is mounted is placed on the pair of inclined surfaces 170 f and accommodated in the housing 170.

  Then, the flange portion 180 b of the lens holder pressing spring 180 is inserted into the hole 170 g of the housing 170, and the lens holder pressing spring 180 is applied to the upper portion of the housing 170. At this time, the upper horizontal surface of the lens holder 121 is pressed downward by the step portion 180 a of the lens holder pressing spring 180. Thereby, the lens holder 121 is pressed against the inclined surface 170f of the housing 170 by the bias of the lens holder holding spring 180, and temporarily fixed so as not to move in the Y-axis direction (front-rear direction) and the Z-axis direction (vertical direction). Is done.

  When the lens holder 121 is temporarily fixed to the housing 170 in this way, a predetermined gap is provided between the lens holder 121 and the inner surface of the housing 170 so that the lens holder 121 can move in the X-axis direction (left-right direction). Exists.

  Next, the rear surface of the laser holder 111 is brought into contact with the outer surface of the housing 170 so that the CAN 110 b of the laser light source 110 is inserted into the U-shaped opening 170 e of the housing 170. A predetermined gap exists between the CAN 110b of the laser light source 110 and the opening 170e of the housing 170 so that the laser light source 110 can move in the YZ axis direction (up / down / left / right direction).

  In this state, while the laser holder 111 is pressed against the housing 170 by the adjustment jig, the laser light source 110 is displaced in the YZ axis direction (up / down / left / right direction), and position adjustment in the YZ axis direction (up / down / left / right direction) is performed. . As a result, the optical axis of the laser light source 110 and the optical axis of the collimator lens 120 are aligned. Further, the position of the lens holder 121 in the X-axis direction (left-right direction) is adjusted. Thereby, the focal position of the collimator lens 120 is appropriately positioned with respect to the light emitting point of the laser light source 110.

  With the above position adjustment, a desired dot pattern can be obtained in the target area.

  After the position is adjusted in this way, the UV adhesive is evenly attached to the boundary between the two front and rear side surfaces of the laser holder 111 and the side surface of the housing 170. After the UV adhesive is attached, the deviation of the optical axis of the laser light is confirmed again. If there is no problem, the UV adhesive is irradiated with ultraviolet rays, and the laser holder 111 is bonded and fixed to the housing 170. If there is a problem in checking the deviation of the optical axis of the laser beam, the laser holder 111 is finely adjusted again, and then the UV adhesive is irradiated with ultraviolet rays, so that the laser holder 111 is bonded and fixed to the housing 170. Is done.

  Further, UV adhesive is evenly attached in the front-rear direction at a position where the lens holder 121 and the inclined surface 170f inside the housing 170 contact each other. After the UV adhesive is attached, the positional relationship between the laser light source 110 and the collimator lens 120 is confirmed again. If there is no problem, the UV adhesive is irradiated with ultraviolet rays, and the lens holder 121 is bonded and fixed to the housing 170. . If there is a problem in confirming the positional relationship between the laser light source 110 and the collimator lens 120, the lens holder 121 is finely adjusted again, and then the UV adhesive is irradiated with ultraviolet rays. Adhered and fixed to.

  Thus, after the installation of the laser light source 110 and the collimator lens 120 with respect to the housing 170 is completed, the flange portion 141b of the DOE holding spring 141 to which the DOE 140 is attached is fitted into the hole 170g of the housing 170, and the DOE holding spring 141 is attached to the housing 170. It is fixed.

  Thereafter, the filter 150 is attached to the filter mounting portion 170d of the housing 170 and fixed by adhesion. Then, the FMD circuit board 161 is inserted into the groove 170b of the housing 170 from above. At this time, the FMD circuit board 161 on which the FMD 160 and the capacitor 161a are mounted is positioned on the FMD mounting section 170c so that the upper end of the FMD circuit board 161 is aligned with the upper end of the FMD mounting section 170c. When the FMD circuit board 161 is positioned in this way, a part of the laser light emitted from the laser light source 110 passes through the leakage mirror 130 mounted on the mirror mounting portion 170a and enters the FMD 160. In this state, it is confirmed whether the detection signal is normally output from the FMD 160. If there is no problem, the FMD circuit board 161 is bonded and fixed to the FMD mounting portion 170c. When the detection signal is not normally output from the FMD 160, the position of the FMD circuit board 161 is adjusted until the detection signal is normally output. Thus, the FMD 160 is mounted on the housing 170 so that the FMD 160 is properly positioned and the light receiving surface of the FMD 160 is perpendicular to the optical axis of the laser light source 110. Further, a portion of the FPC 161 b between the FMD circuit board 161 and the temperature detection circuit board 162 is bonded to the rear side surface of the housing 170. Thereby, the temperature detection circuit board 162 is positioned at a position facing the rear side surface of the laser holder 111. Thus, the assembly of the light emitting device 10 is completed.

  In the present embodiment, as described above, since the projection optical system 100 is configured such that the optical path of the laser light emitted from the laser light source 110 is bent, the light emitting device 10 can be thinned in the Z-axis direction. it can. Here, since it is not necessary to arrange a photodetector for back monitoring in the CAN 110b of the laser light source 110, the diameter of the CAN 110b can be reduced, and even if the light emitting device 10 is made thinner, this reduction in thickness can be achieved. It is not limited by the diameter of the CAN 110b.

  In addition, since the filter 150 is arranged in the optical path from the leakage mirror 130 to the FMD 160, the amount of light of the laser light source 110 can be controlled appropriately without saturation of the detection signal of the FMD 160 even when the leakage mirror 130 having a high transmittance is used. It can be performed. Since the filter 150 has a thin flat plate shape, even if the filter 150 is arranged in this way, the size of the housing 170 is not greatly affected.

  5 and 6 are perspective views showing the assembly process of the information acquisition device 1. For convenience, the assembly process of the light receiving device 20 is not shown. The light receiving device 20 is a device in which the light receiving optical system 200 in FIG. 2 is unitized with other components. The aperture 210, the imaging lens 220, and the filter 230 are accommodated in the cylindrical portion 261 of the lens holder 260. Further, the CMOS image sensor 240 is mounted on the lower surface of the lens holder 260 via the image sensor circuit board 241.

  In FIG. 5, reference numeral 300 denotes a base plate that supports the light emitting device 10 and the light receiving device 20.

  The light emitting device 10 and the light receiving device 20 are disposed on the base plate 300. As illustrated, the base plate 300 has a shape with a narrow width in the front-rear direction (Y-axis direction) and a wide width in the left-right direction (X-axis direction). The base plate 300 has a rib 300a whose outer edge is one step higher than other portions. The rib 300a makes it difficult for the base plate 300 to bend in the positive and negative directions of the Z axis. Therefore, the detection accuracy of the information acquisition apparatus 1 can be ensured even when the base plate 300 having a narrow width in the front-rear direction is used as in the present embodiment.

  The base plate 300 is formed with openings 301 and 302 for positioning when the light emitting device 10 is attached to the base plate 300, and screw holes (not shown) for attaching the light emitting device 10 are formed.

  In addition, the base plate 300 is formed with an opening 303 for fitting the cylindrical portion 261 of the lens holder 260 from below (Z-axis negative direction). The opening 303 has the same shape as the outer diameter of the cylindrical portion 261 and has a dimension that allows the cylindrical portion 261 to be fitted therein. Further, the base plate 300 is formed with screw holes 304a for temporarily fixing the lens holder 260 when adjusting the position, and four holes 304b for pouring an adhesive when fixing the adhesive.

  The light emitting device 10 and the light receiving device 20 need to be arranged so that the exit pupil of the light emitting device 10 and the entrance pupil of the light receiving device are aligned on a straight line in the X-axis direction. Therefore, the base plate 300 has a step 305, and when the light receiving device 20 is attached to the base plate 300 from below (Z-axis negative direction), the position of the exit pupil of the light emitting device 10 matches the position of the entrance pupil of the light receiving device 20. Thus, the periphery of the right end of the base plate 300 is raised by one step in the laser light projection direction (Z-axis positive direction). The exit pupil of the light emitting device 10 is in the vicinity of the exit surface of the DOE 140, and the entrance pupil of the light receiving device 20 is the position of the aperture of the aperture 210.

  The installation interval between the light emitting device 10 and the light receiving device 20 is set according to the distance between the information acquisition device 1 and the reference plane of the target area. The distance between the reference plane and the information acquisition device 1 varies depending on how far away the target is to be detected. The closer the distance to the target to be detected is, the narrower the interval between the light emitting device 10 and the light receiving device 20 is. Conversely, as the distance to the target to be detected increases, the installation interval between the light emitting device 10 and the light receiving device 20 increases.

  As described above, the size of the base plate 300 increases in the direction in which the light emitting device 10 and the light receiving device 20 are arranged.

When assembling the information acquisition device 1, first, the light emitting device 10 is disposed on the base plate 300 from above so that the bottom surface of the housing 170 contacts the edges of the openings 301 and 302 of the base plate 300. In this state, screw holes (not shown) formed in the base plate 300 and screw holes 170i (see FIG. 4) formed in the bottom surface of the light emitting device 10 are combined, and the housing 170 is connected to the base plate via these screw holes. 300 is screwed.

  Next, from the lower side, the light receiving device 20 is disposed so that the cylindrical portion 261 is fitted into the opening 303 and the base plate mounting portion 262 of the lens holder 260 is in contact with the base plate 300. In this state, the screw holes 304a formed in the base plate 300 and the screw holes 262a formed in the lens holder 260 are combined, and the lens holder 260 is screwed to the base plate 300 through these screw holes. Thereafter, after the angle of the light receiving device 20 is adjusted, an adhesive is introduced from the hole 304b, and the light receiving device 20 is bonded and fixed to the base plate 300. In this way, the structure shown in FIG. 6 is assembled.

  One end of the FPC 161b of the light emitting device 10 is connected to the temperature detection circuit board 162, one end is connected to the FMD circuit board 161, and the other end is connected to the circuit board 500 in the subsequent stage (see FIG. 7). . The temperature detection circuit board 162 is disposed in the vicinity of the laser light source 110.

  One end of the FPC 241 b of the light receiving device 20 is connected to the image sensor circuit board 241, and the other end is connected to the circuit board 500 (see FIG. 7) at the subsequent stage. A circuit portion of the information acquisition device 1 such as the laser drive circuit 22 and the CPU 21 shown in FIG. 2 is mounted on the circuit board 500. Thereafter, a cover member (not shown) for protecting the base plate 300 from the outside is attached, and the assembly of the information acquisition device 1 is completed.

  FIG. 7 is a schematic diagram illustrating a configuration of the information acquisition apparatus 1 according to the present embodiment. FIG. 7 is a view of the information acquisition device 1 shown in FIG. 6 as viewed from the rear side, in which the insides of the light emitting device 10 and the light receiving device 20 are seen through.

  Referring to FIG. 7, as described above, the installation interval Da between the light emitting device 10 and the light receiving device 20 is increased to some extent. Further, since the laser light source 110, the collimator lens 120, and the leakage mirror 130 are arranged side by side in the X-axis direction, the distance La from the light emission center p of the DOE 140 to the laser light source 110 and the light emission center p of the DOE 140. As for the distance Lb to the FMD 160, the distance La tends to be larger. Therefore, in order to reduce the size of the information acquisition device 1, it is desirable that the laser light source 110 be arranged in a direction approaching the light receiving device 20 as in the present embodiment.

  In this case, the size of the base plate 300 in the positive direction of the X axis is determined by the distance Lb from the light emission center p of the DOE 140 to the FMD 160. Therefore, in order to further reduce the size of the base plate 300 in the X-axis direction, it is desirable that the distance Lb is as small as possible.

  Here, the filter 150 is made of a resin material containing a dye or the like that absorbs infrared light, and has a thin shape with a thickness Df. For this reason, the distance Lb can be kept small. Instead of the filter 150, for example, a glass ND filter (Neutral Density Filter), a glass material containing a dye similar to the filter 150, or the like can be used. However, since these are considerably thicker than the filter 150, the use of these members increases the distance Lb, leading to an increase in the size of the information acquisition device 1.

  Further, since the filter 150 can be manufactured by a simple method of mixing a dye into a resin material or the like, the manufacturing cost is lower than using other filters.

Therefore, as in the present embodiment, by using the filter 150 in which a dye or the like that absorbs light from the laser light source 110 is mixed in a resin material, the manufacturing cost of the information acquisition device 1 is reduced, and the size of the device is increased. Can be suppressed.

  FIG. 8 is a diagram showing APC control processing. The process of FIG. 8 is performed by the APC control unit 21b of FIG.

  Referring to FIG. 8A, the APC control unit 21b acquires a PD signal corresponding to the received light amount output from the PD signal processing circuit 23 at the laser emission timing by the laser control unit 21a (S101: YES) ( S102). Then, the APC control unit 21b determines whether the amount of light received by the FMD 160 is within the specified light amount range based on the acquired PD signal value (S103). The prescribed light amount is defined by two threshold values corresponding to the upper limit value and the lower limit value of the appropriate light emission amount of the laser light source 110, and these two threshold values are stored in the memory 26 in advance.

  If the received light amount is within the specified light amount (S103: YES), the APC control unit 21b determines that the laser light source 110 has emitted an appropriate amount of laser light, and advances the process to S107. On the other hand, when the received light amount is not within the prescribed light amount (S103: NO), the APC control unit 21b determines that the laser light source 110 emits an inappropriate amount of laser light, and the received light amount is less than the prescribed light amount. Is also larger (S104).

  When the received light amount is larger than the prescribed light amount (S104: YES), the APC control unit 21b outputs a signal for reducing the light emission amount of the laser light emitted from the laser light source 110 to the laser control unit 21a by one step ( S105). In response to this, the laser control unit 21a decreases the light emission amount of the laser light source 110 by one step. As a result, the amount of light emitted from the laser light source 110 is reduced by one step.

  When the received light amount is smaller than the prescribed light amount (S104: NO), the APC control unit 21b outputs a signal for increasing the light emission amount of the laser light emitted from the laser light source 110 to the laser control unit 21a by one step ( S106). In response to this, the laser control unit 21a increases the light emission amount of the laser light source 110 by one step. As a result, the amount of light emitted from the laser light source 110 is increased by one step.

  Thereafter, it is determined whether it is the end timing of laser emission (S107). If it is not the end timing of laser emission (S107: NO), the process of adjusting the light emission amount of the laser light source 110 (S102 to S107) is repeated. When the laser emission end timing is reached (S107: YES), the APC control unit 21b ends the APC control process, returns to S101, and waits for the next emission timing.

  FIG. 8B is a diagram schematically illustrating an example of a change in the detection signal of the FMD 160 over time in the present embodiment, and FIG. 8C is a comparative example in which the filter 150 is not disposed. It is a figure which shows typically the example of the change of the detection signal of FMD160 by progress of time. In the figure, the horizontal axis indicates the passage of time, and the vertical axis indicates the magnitude of the detection signal (PD signal) of the FMD 160. In step S103, S2 is set as the upper limit value of the prescribed light amount, and S1 is set as the lower limit value. Sm is a limit value of the detection signal that can be output by the FMD 160.

  Referring to FIG. 8B, at time T1, the PD signal is below S1, which is the lower limit value of the prescribed light amount. In this case, the amount of light emitted from the laser light source 110 is increased by the processing of S106 and is positioned within the range of the prescribed light amount.

At times T2 and T4, since the PD signal is within the prescribed light amount range, the laser light source 110
The amount of light is not controlled.

  At time T3, the PD signal exceeds S2, which is the upper limit value of the prescribed light amount. In this case, the amount of light emitted from the laser light source 110 is lowered by the processing of S105 and is positioned within the range of the prescribed light amount.

  In this way, the amount of light emitted from the laser light source 110 is kept within the range of the prescribed light amount.

  Referring to FIG. 8C, when the filter 150 is not arranged, the laser light from the laser light source 110 is not attenuated, and a large amount of laser light enters the FMD 160. In this case, the PD signal from the FMD 160 is saturated, and the limit value of the PD signal that can be output by the FMD 160 is output in all the sections of time T1 to T4. Therefore, actually, even if there is a change in the light emission amount from the laser light source 110 as shown in FIG. 8B, the change in the light amount cannot be read from the PD signal output from the FMD 160, and the laser light source is appropriately 110 light quantity control cannot be performed.

  As described above, in this embodiment, even when the laser light having a large light emission amount and the leakage mirror 130 having a high transmittance are used, the light amount of the laser light is attenuated to the detectable range of the FMD 160 by the filter 150. Therefore, the light amount control of the laser light source 110 can be appropriately performed.

  As described above, according to the present embodiment, since the projection optical system 100 is configured so that the optical path of the laser light emitted from the laser light source 110 is bent, the height of the light emitting device 10 in the direction toward the target region is reduced. can do.

  Further, according to the present embodiment, since the filter 150 is arranged in the optical path from the leakage mirror 130 to the FMD 160, the detection signal of the FMD 160 is not saturated even when the leakage mirror 130 having a high transmittance is used. The light quantity control of the laser light source 110 can be appropriately performed.

  Furthermore, according to the present embodiment, the filter 150 in which a dye or the like that absorbs the light of the laser light source 110 is mixed into the resin material is used as the light amount adjusting member, so that the manufacturing cost of the information acquisition device 1 is suppressed. , Increase in size of the apparatus can be suppressed.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made to the embodiment of the present invention in addition to the above. .

  For example, in the above embodiment, the filter 150 is disposed between the leakage mirror 130 and the FMD 160 so as to be perpendicular to the optical axis of the collimator lens 120. However, as shown in FIG. The filter 150 may be attached to the back surface of the mirror 130, and the filter 150 and the leakage mirror 130 may be integrated. Further, in this configuration, the FMD 160 may be disposed in a back space formed by tilting the leakage mirror 130 and the filter 150. In this case, the distance Lb ′ from the light emission center p of the DOE 140 to the FMD 160 is smaller than that in the above embodiment. Therefore, the light emitting device 10 and the information acquisition device 1 can be further downsized in the X-axis direction.

In this embodiment, since the filter 150 mixed with the dye is used, the filter characteristics of the filter 150 are not substantially changed even when the incident angle of light is changed. Therefore, as shown in FIG. 9A, even if the filter 150 is disposed so as to be inclined with respect to the optical axis of the laser light source 110, the attenuation of the laser light by the filter 150 can be appropriately performed.

  In the above embodiment, the light emitting device 10 is configured such that the optical path of the laser light emitted from the laser light source 110 is bent. However, as shown in FIG. 9B, from the laser light source 110 to the DOE 140. The optical elements may be arranged in the projection direction (Z-axis direction). In this case, a spectroscopic element 190 having a high transmittance is used. However, the present invention is preferable for use in a configuration in which the height of the projection optical system 100 is suppressed by bending the optical path of the laser light emitted from the laser light source 110 as in the above embodiment. In other words, in this configuration, when the thickness in the height direction is reduced, the back monitor photodetector cannot be disposed in the CAN 110b of the laser light source 110. Since the present invention is configured to disperse part of the laser light emitted from the laser light source, in such an optical system in which a photodetector for back monitoring cannot be arranged in the CAN 110b of the laser light source 110, It is more effective.

  In the above-described embodiment, the leakage mirror 130 is used as the spectroscopic element. However, a polarizing beam splitter that splits the light according to the polarization direction, a diffraction grating that splits by a diffraction phenomenon, a diffractive optical element, or the like may be used. When these spectroscopic elements are used, the amount of light incident on the FMD 160 tends to increase. However, by adjusting the amount of light shielded by the filter 150, the amount of light detected by the FMD 160 can be appropriately controlled without saturation of the detection signal of the FMD 160. Can do.

  Moreover, in the said embodiment, the dye which absorbs infrared light was mixed in the filter 150 as a light quantity adjustment member, However, If the light quantity of the laser light source 110 can be attenuated, it will absorb the light of what wavelength band May be mixed, or a plurality of types of materials may be mixed.

  Further, instead of the filter 150, an optical interference filter such as a band pass filter may be used. In this case, the light emitting device 10 and the information acquisition device 1 are slightly larger in the X-axis direction than when the filter 150 is used.

  Moreover, as long as the installation position and installation angle of the filter 150 are between the leakage mirror 130 and the FMD 160, any position and angle other than the installation position and installation angle of the above-described embodiment and modification example may be used. Good.

  In the above embodiment, the filter 150 is made of a resin material and formed in a flat plate shape. However, any material may be used, and any shape may be used.

  Furthermore, although the step 305 is formed in the base plate 300 in the above embodiment, the step may not be formed. Further, although the light receiving device 20 is attached to the back surface of the base plate 300, it may be installed on the upper surface of the base plate 300 as in the light emitting device 10.

  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. The information acquisition device 1 and the information processing device 2 may be integrated, or the information acquisition device 1 and the information processing device 2 may be integrated with a television, a game machine, or a personal computer.

  The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims.

DESCRIPTION OF SYMBOLS 1 ... Information acquisition apparatus 10 ... Light-emitting device 20 ... Light-receiving device 21a ... Laser control part 21b ... APC control part (laser control part)
DESCRIPTION OF SYMBOLS 110 ... Laser light source 120 ... Collimator lens 130 ... Leakage mirror (spectral element)
140 ... DOE (diffractive optical element)
150 ... Filter (light quantity adjusting member, light absorbing plate)
160 ... FMD (light detector)

Claims (6)

In an information acquisition device that acquires information on a target area using light,
A light emitting device that projects a laser beam with a predetermined dot pattern onto a target area;
A light receiving device that is arranged so as to be laterally separated from the light emitting device by a predetermined distance, and that images the target area,
The light emitting device;
A laser light source that emits laser light of a predetermined wavelength;
A collimator lens for converting laser light emitted from the laser light source into parallel light;
A spectroscopic element for branching the laser light transmitted through the collimator lens;
A diffractive optical element that converts the first laser beam dispersed by the spectroscopic element into a laser beam having a predetermined dot pattern in the target region and projects the laser beam onto the target region;
A photodetector that receives the second laser beam dispersed by the spectroscopic element and outputs a detection signal corresponding to the amount of received light;
A light amount adjusting member that is disposed between the spectroscopic element and the photodetector and attenuates the amount of the second laser light that reaches the photodetector;
A laser control unit that controls a light emission amount of the laser light source based on the detection signal of the photodetector;
An information acquisition apparatus characterized by that. The information acquisition device according to claim 1,
The spectroscopic element reflects a part of the laser light and guides it to the diffractive optical element, transmits a part of the laser light and guides it to the light amount adjusting member,
The laser light source, the collimator lens, the spectroscopic element, the light amount adjusting member, so that the laser light source, the collimator lens and the spectroscopic element are arranged in a straight line, and the diffractive optical element faces the target region. The photodetector and the diffractive optical element are disposed;
An information acquisition apparatus characterized by that. The information acquisition device according to claim 2,
The spectroscopic element is a leakage mirror arranged to be inclined with respect to the optical axis of the laser light source,
The information acquisition device, wherein the light amount adjusting member is attached to a surface of the leakage mirror on the photodetector side. In the information acquisition device according to any one of claims 1 to 3,
The light amount adjusting member contains at least a light absorbing material that absorbs light of the wavelength of the laser light source.
An information acquisition apparatus characterized by that. The information acquisition device according to claim 4,
The light amount adjusting member is a light absorbing plate made of a flat resin material containing the light absorbing material.
An information acquisition apparatus characterized by that.   An object detection apparatus comprising the information acquisition apparatus according to any one of claims 1 to 5.

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