JP2011117849A - Object detecting device and information obtaining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simply structured information obtaining device which can accurately obtain information of a target area, and an object detecting device for mounting the same thereon. <P>SOLUTION: The information obtaining device 1 includes a laser light source 11 emitting light having a wavelength of about 800 nm, a temperature regulation element 12 regulating a temperature of the laser light source 11, a temperature sensor 13 detecting the temperature of the laser light source 11, a filter 211 for transmitting reflection light reflected from the target area, a CMOS image sensor 23 receiving the reflection light permeating the filter 211 and outputting a signal, and a filter drive part 200 changing a tilt angle of the filter 211 against the reflection light. A CPU 31 controls the temperature regulation element 12 and the filter drive part 200 so that a light receiving amount of the CMOS image sensor 23 may be maximized within a temperature range of the laser light source 11, which can be set by the temperature regulation element 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

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. For example, in a vehicle-mounted laser radar, laser light is projected from the front of the vehicle, and it is determined whether an object is present in front of the vehicle based on the presence or absence of reflected light at that time. Further, the distance to the object is detected based on the laser light projection timing and the reflected light reception timing. In addition, an arcade game machine, a security system, and the like are also equipped with an object detection device that uses infrared light to detect a person or a gesture thereof.

JP 2008-70157 A

  In such an object detection device, light in a predetermined wavelength band is projected onto a target area from a light source such as a semiconductor laser or an LED (Light Emitting Device). In this case, in order to guide only light in the wavelength band to a light receiving element such as a PSD (Position Sensitive Detector) or a CMOS image sensor, a narrow band filter having the band as a transmission band is used. When the wavelength of the light emitted from the light source changes, changing the tilt angle of the filter can suppress the decrease in the amount of light emitted to the light receiving element from the light emitted from the light source. it can. Further, since the wavelength of light emitted from the light source changes according to the temperature change of the light source, a temperature adjusting element such as a Peltier element is used to suppress the temperature change of the light source.

  However, the temperature range of the light source that can be adjusted by the temperature adjusting element as described above is limited. For this reason, even if the temperature of the light source is adjusted by the temperature adjusting element, there is a possibility that the wavelength of light emitted from the light source cannot be set to a predetermined wavelength band. Further, when changing the tilt angle of the filter, a rotation space for the filter is required in the apparatus, which causes a problem that the apparatus becomes large.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an information acquisition device that can accurately acquire information on a target area with a simple configuration and an object detection device equipped with the information acquisition 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 apparatus according to this aspect includes a light source that emits light of a predetermined wavelength band, a temperature adjustment element that adjusts a temperature of the light source, a temperature sensor that detects a temperature of the light source, and the light emitted from the light source. A projection optical system for projecting light toward the target area, a filter for transmitting the reflected light reflected from the target area, and a light receiving element for receiving the reflected light transmitted through the filter and outputting a signal And an actuator that changes an inclination angle of the filter with respect to the reflected light, and the temperature adjustment element and the temperature adjustment element so that the amount of light received by the light reception element is maximized within a temperature range of the light source that can be set by the temperature adjustment element. A control unit for controlling the actuator.

  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.

  As described above, according to the present invention, it is possible to provide an information acquisition device that can accurately acquire information on a target area with a simple configuration and an object detection device equipped with the information acquisition device.

  The features of the present invention will become more apparent from the following description of embodiments. However, the following embodiment is merely one embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the following embodiment. Absent.

It is a figure which shows the structure of the object detection apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the information acquisition apparatus and information processing apparatus which concern on Embodiment 1. FIG. It is a figure explaining the process of the three-dimensional distance calculating part which concerns on Embodiment 1. FIG. 2 is a diagram illustrating a configuration of a main part of a light receiving module according to Embodiment 1. It is a figure which shows the structure of the light source module which concerns on Embodiment 1, and a light reception module. It is a figure which shows the structure of the light source module which concerns on Embodiment 1 in detail. It is a figure which shows the structure of the filter drive part which concerns on Embodiment 1 in detail. It is a figure which shows the relationship between the detection temperature of the temperature sensor which concerns on Embodiment 1, and the wavelength of a laser beam, and the figure which shows the relationship between the inclination-angle of a filter, and the transmittance | permeability. It is a figure which shows the reference table which concerns on Embodiment 1, and a figure which shows the relationship between the atmospheric temperature of a laser light source, and the detection temperature of a temperature sensor. 4 is a flowchart illustrating temperature control of a laser light source and tilt angle control of a filter according to the first embodiment. 4 is a flowchart illustrating temperature control of a laser light source and tilt angle control of a filter according to the first embodiment. It is a figure which shows the structure of the information acquisition apparatus which concerns on Embodiment 2. FIG. It is a figure which shows the structure of the filter drive part which concerns on Embodiment 2 in detail. It is a figure which shows the structure of the light source module which concerns on Embodiment 3 in detail. 10 is a flowchart showing update control of a target temperature and a target inclination angle according to the third embodiment. It is a modification of the flowchart which shows the temperature control of the laser light source which concerns on Embodiment 3, and the inclination-angle control of a filter. It is a figure explaining the update of the target temperature and the target inclination angle which concern on Embodiment 4, and the shift of the referenceable range.

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

<Embodiment 1>
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 sends a control signal to the television 3 according to the gesture. An application program to output 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 light source module 10 and a light receiving module 20 as a configuration of the optical unit. In addition, as a configuration of the circuit unit, a CPU (Central Processing Unit) 31, a laser driving circuit 32, a temperature control element driving circuit 33, an imaging signal processing circuit 34, a motor driving circuit 35, a memory 36, an input / output A circuit 37 is provided.

  The light source module 10 includes a laser light source 11, a temperature adjustment element 12, a temperature sensor 13, and a projection lens 14. The laser light source 11 is made of, for example, a semiconductor laser, and outputs laser light in a narrow wavelength band with a wavelength of about 800 nm. The temperature control element 12 is composed of a thermoelectric element such as a Peltier element. The temperature control element 12 heats or cools the laser light source 11. The temperature sensor 13 indirectly detects the temperature of the laser light source 11 and outputs a detection signal to the CPU 21. The projection lens 14 spreads and projects the laser beam emitted from the laser light source 11 over the entire target area.

  The detailed configuration of the light source module 10 will be described later with reference to FIGS.

  The light receiving module 20 includes an aperture 21, an imaging lens 22, a CMOS image sensor 23, and a filter driving unit 200. The laser light reflected from the target area is incident on the imaging lens 22 through the aperture 21. The aperture 21 stops the light from the outside so as to match the F number of the imaging lens 22. The imaging lens 22 condenses the light incident through the aperture 21 on the CMOS image sensor 23.

  The CMOS image sensor 23 receives the light collected by the imaging lens 22 and outputs a signal (charge) corresponding to the amount of received light to the imaging signal processing circuit 34 for each pixel. Here, in the CMOS image sensor 23, 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 34 with high response from light reception in each pixel.

  The filter driving unit 200 includes a filter 211. The filter driving unit 200 tilts the filter 211 in a direction parallel to the YZ plane from a state parallel to the XY plane in the drawing according to the drive signal output from the motor drive circuit 35. The filter 211 is a band-pass filter that transmits light in a wavelength band substantially matching the emission wavelength band of the laser light source 11 and cuts other wavelength bands. The filter 211 is a dielectric film interference filter such as a Fabry-Perot filter, and the shape of the filter 211 is a parallel plate shape having a predetermined thickness.

  The detailed configuration of the light receiving module 20 will be described later with reference to FIGS.

  The CPU 31 controls each unit according to a control program stored in the memory 36. With this control program, the CPU 31 is provided with the function of the three-dimensional distance calculation unit 31a for generating three-dimensional distance information.

  The laser drive circuit 32 drives the laser light source 11 according to a control signal from the CPU 31. Here, the laser drive circuit 32 drives the laser light source 11 according to a predetermined modulation method. As a result, laser light having a unique modulation pattern is emitted from the laser light source 11. The temperature adjustment element drive circuit 33 drives the temperature adjustment element 12 according to a control signal from the CPU 31.

  The imaging signal processing circuit 34 controls the CMOS image sensor 23 and sequentially takes in the signal (charge) of each pixel generated by the CMOS image sensor 23 for each line. Then, the captured charges are sequentially output to the CPU 31 as a signal. Based on the signal supplied from the imaging signal processing circuit 34, the CPU 31 calculates the distance from the information acquisition device 1 to each pixel position by processing by the three-dimensional distance calculation unit 31a. At this time, the CPU 31 determines whether the signal at each pixel position is modulated in the same manner as the laser beam modulation method in the laser drive circuit 32, and only when the signal is modulated in the same manner, Used to calculate distance.

  The motor drive circuit 35 controls the filter drive unit 200 according to a control signal from the CPU 31. The memory 36 holds a table for setting the detected temperature of the temperature sensor 13 and the inclination angle of the filter 211 in addition to a program for the CPU 31 to control each unit. Such a table will be described later with reference to FIG.

  The input / output circuit 37 controls data communication with the information processing apparatus 2.

  The information processing apparatus 2 includes a CPU 41, a memory 42, and an input / output circuit 43. 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 42. However, the configuration of these peripheral circuits is not shown for the sake of convenience.

  The CPU 41 controls each unit according to a control program (application program) stored in the memory 42. With such a control program, the CPU 41 is given the function of the object detection unit 41a 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 42, for example.

  For example, when the control program is a game program, the object detection unit 41a 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 41 a detects a person and its movement (gesture) in the image 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 1 is executed by the control program in accordance with the detected movement (gesture).

  The input / output circuit 43 controls data communication with the information acquisition device 1.

  FIG. 3 is a diagram illustrating processing in the three-dimensional distance calculation unit 31a.

  When the information acquisition process in the information acquisition apparatus 1 is activated in response to a command from the information processing apparatus 2, laser light is projected from the laser light source 11 toward the target area with a unique modulation pattern. At this time, if a person (M) is present in the target area as shown in FIG. Thus, the image of the person (M) is projected onto the CMOS image sensor 23.

At this time, of the laser light from the laser light source 11, the light hitting the position Po of the person (M) enters the position of the pixel Pp on the CMOS image sensor 23. Therefore, if the time difference between the emission timing of the modulated laser beam in the laser light source 11 and the light reception timing of the modulated laser beam in the pixel Pp is Δt, the distance Dp from the information acquisition device 1 to the position Po of the person (M) is
Dp = C × Δt (C: speed of light) (1)
Is required. The distances of other positions of the person (M) can be obtained in the same manner.

  The three-dimensional distance calculation unit 31a is based on the time difference ΔT from when the modulated laser beam emission command is given to the laser drive circuit 32 until the received signal of the modulated laser beam at each pixel is input from the imaging signal processing circuit 34. In addition, considering the time lag in each circuit unit and the response of the laser light source 11 and the CMOS image sensor 23, the time difference Δt in the above equation (1) is obtained for each pixel, and the calculation of the equation (1) is performed based on the obtained Δt. To obtain the distance from the information acquisition device 1 to each position of the person (M). At this time, if there are objects, walls, etc. in addition to the person (M) in the target area, the distance is similarly determined for these.

  The three-dimensional distance calculation unit 31a outputs the distance of each position in the target area thus obtained to the information processing device 2 as three-dimensional distance information. In this case, for example, when the person (M) moves his / her hand straight back and forth, three-dimensional distance information in which the distance of the hand position changes is sequentially output to the information processing apparatus 2. The object detection unit 41a of the information processing device 2 performs the detection of the person (M) and the operation of moving the hand back and forth based on the three-dimensional distance information changing in this way. Detection is performed. Then, the CPU 41 performs a control operation defined in the control program based on the detection result.

  FIG. 4 is a diagram illustrating a configuration of a main part of the light receiving module 20.

  In FIG. 2A, reference numeral 24 denotes a holding cylinder that holds the aperture 21 and the imaging lens 22. The holding cylinder 24 has a hollow box shape with an open bottom, and houses an imaging lens 22 composed of a plurality of lens groups. A circular opening is formed in the upper part of the holding cylinder 24, and the aperture 21 is mounted on the upper part of the holding cylinder 24 so as to face the outside from this opening.

  Reference numeral 210 denotes an actuator that changes the tilt angle of the filter 211. An opening for allowing light to pass through is formed in the center of the actuator 210, and a filter 211 is mounted on the upper surface of the actuator 210 so as to cover the opening. The actuator 210 is a part of the filter driving unit 200 shown in FIG. Details of the actuator 210 will be described later with reference to FIG.

  Reference numeral 302 denotes a circuit board on which the CMOS image sensor 23 is mounted. In addition to the CMOS image sensor 23, circuits related to the CMOS image sensor 23 are arranged on the circuit board 302. 303 is a flexible cable, and 304 is a connection terminal. The flexible cable 303 mediates signal transmission between the circuit board 302 and the connection terminal 304. The connection terminal 304 is connected to a circuit board 301 described later. The connection terminal 304 outputs a signal output from the CMOS image sensor 23 side to the circuit board 301 and outputs a control signal output from the circuit board 301 to the CMOS image sensor 23 side.

  Reference numeral 25 denotes a holding frame for holding the actuator 210 on the circuit board 302. The holding frame 25 has an opening for allowing light to pass through in the center.

  At the time of assembly, the holding frame 25 is installed on the circuit board 302 so that the opening of the holding frame 25 is positioned right above the CMOS image sensor 23 as shown in FIG. Subsequently, the actuator 210 is installed on the holding frame 25 so that the filter 211 is positioned right above the CMOS image sensor 23. Further, the holding cylinder 24 is installed on the actuator 210. FIG. 2B shows a state in which the holding cylinder 24, the actuator 210, the holding frame 25, and the circuit board 302 are assembled.

  FIG. 5 is a diagram illustrating the configuration of the light source module 10 and the light receiving module 20 of the information acquisition apparatus 1.

  As illustrated, the light source module 10 and the light receiving module 20 are disposed on a chassis 310 and a circuit board 301 that are horizontally long in the X-axis direction, respectively. The chassis 310 is a plate-like member made of a metal having high thermal conductivity. The chassis 310 has a function of radiating heat from components arranged on the chassis 310.

  The light source module 10 is installed on the chassis 310 via the temperature control element 12 as illustrated. The light source module 10 has a cover 15 as illustrated, and the cover 15 is installed on the temperature control element 12. The cover 15 accommodates the laser light source 11, the temperature adjustment element 12, the temperature sensor 13, and the projection lens 14 of FIG. Further, an emission window 15a is formed on the surface of the cover 15 in the positive Z-axis direction, and the laser light emitted from the laser light source 11 is emitted to the target region through the emission window 15a.

  The main part of the light receiving module 20 shown in FIG. 4 is installed on a circuit board 301 as shown. That is, the circuit board 302 is fixed on the circuit board 301, and the connection terminal 304 (see FIG. 4) is connected to a connector (not shown) on the circuit board 301.

  As shown in the figure, the gear portion 220 is installed on the flange portion 310 a of the chassis 310, and includes a worm gear 221 and gears 222 and 223. A stepping motor 230 is driven by the motor control circuit 35. 2 includes an actuator 210, a gear unit 220, and a stepping motor 230. The detailed configuration of the gear unit 220 and the stepping motor 230 and the relationship between the gear unit 220 and the actuator 210 will be described later with reference to FIG.

  FIG. 6 is a diagram showing the configuration of the light source module 10 in detail.

  The light source module 10 includes a laser holder 16 in addition to the laser light source 11, the temperature control element 12, the temperature sensor 13, the projection lens 14, and the cover 15 shown in FIG.

  As illustrated, the temperature control element 12 is installed on the chassis 310. The laser holder 16 is made of a member having thermal conductivity, and holds the laser light source 11. The laser holder 16 is disposed so as to be in contact with the temperature control element 12. The temperature sensor 13 is installed on the side surface of the laser holder 16. Thereby, the temperature control element 12 can heat or cool the laser light source 11 via the laser holder 16, and the temperature sensor 13 indirectly (CAN) of the laser light source 11 via the laser holder 16. The temperature can be detected.

  A wire 17 for supplying power to the laser light source 11 is connected to a terminal of the laser light source 11. The other end of the wiring 17 is connected to the circuit board 301. For this reason, an opening through which the wiring 17 passes is formed in the cover 15 and the laser holder 16. A drive current is applied to the laser light source 11 via the circuit board 301.

  FIG. 7A is a diagram showing the configuration of the actuator 210 in detail.

  The actuator 210 includes a filter 211, a base 212, a holder 213, and shafts 214 and 215.

  Wall portions 212a and 212b are formed on the left and right of the base 212. Further, shaft holes 212c and 212d are respectively formed in the wall portions 212a and 212b, and the shafts 214 and 215 are rotatably inserted into the shaft holes 212c and 212d. The shaft 214 has a stopper at the end. An opening 212e for allowing light to pass through is formed at the bottom of the base 212.

  The holder 213 is made of a frame member having an opening 213a for allowing light to pass through in the center, and holes for fitting with the shafts 214 and 215 are formed on the left and right walls. A step portion 213b is formed on the upper surface of the holder 213, and the filter 211 is fitted and attached to the step portion 213b.

  At the time of assembly, first, the holder 213 is accommodated between the walls 212 a and 212 b of the base 212. Then, the shafts 214 and 215 are fitted into the holes of the holder 213 while being inserted into the shaft holes 212c and 212d. Thereby, the assembly of the actuator 210 is completed.

  FIG. 7B is a diagram illustrating a detailed configuration of the gear unit 220 and the stepping motor 230.

  When the stepping motor 230 is driven by the motor drive circuit 35, the worm gear 221 mounted on the drive shaft of the stepping motor 230 rotates around the Y axis. Thereby, the gear 222 fitted to the worm gear 221 is rotated around the X axis. A gear 222 a having a smaller diameter than the outer periphery is formed on the inner periphery of the gear 222. When the gear 222 rotates, the gear 223 that meshes with the gear 222a is rotated. A shaft hole 223 a is provided at the center of the gear 223. The shaft 215 of the actuator 210 is passed through and fixed to the shaft hole 223a.

  FIG. 7C is a diagram showing a state where the actuator 210 and the gear unit 220 are connected. For the gear portion 220, only the gear 223 is shown for convenience.

  Thus, when the shaft 215 of the actuator 210 is fixed to the shaft hole 223a of the gear 223, the holder 213 is rotated about the shafts 214 and 215 by rotating the gear 223. Thus, when the stepping motor 230 is driven, the gear 223 is rotated, and the filter 211 is tilted in a direction parallel to the YZ plane from a state parallel to the XY plane.

  FIG. 8A is a diagram (simulation result) showing the relationship between the temperature detected by the temperature sensor 13 and the wavelength of the laser beam. The horizontal axis represents the detected temperature of the temperature sensor 13, and the vertical axis represents the wavelength of the laser light emitted from the laser light source 11.

  From FIG. 5A, it can be seen that the wavelength of the laser light emitted from the laser light source 11 changes with a change in the temperature detected by the temperature sensor 13. That is, it can be seen that the wavelength of the laser light emitted from the laser light source 11 changes when the temperature detected by the temperature sensor 13 changes due to the temperature of the laser light source 11 changing.

  FIG. 8B is a diagram (simulation result) showing the relationship between the tilt angle of the filter 211 and the transmittance. The horizontal axis represents the tilt angle (tilt angle in the tilt direction) when the filter 211 is tilted in the direction parallel to the YZ plane from the state perpendicular to the Z axis in FIG. On the other hand, the transmittance of light traveling in the Z-axis direction in FIG. 2 is shown. In FIG. 8B, light transmittances of five wavelengths (795 nm, 800 nm, 805 nm, 810 nm, and 815 nm) are shown. In this case, the filter 211 has the maximum transmittance when light having a wavelength of about 810 nm (hereinafter referred to as “optimum wavelength”) is incident on the filter 211 perpendicularly.

  From FIG. 8B, when the wavelength of light incident on the filter 211 in the Z-axis direction in FIG. 2 changes from the optimum wavelength of 810 nm, the maximum transmittance decreases and becomes the maximum transmittance. It can be seen that the inclination angle of the filter 211 changes. That is, when the wavelength of light incident on the filter 211 in the Z-axis direction in FIG. 2 changes from the optimum wavelength, it is necessary to change the tilt angle of the filter 211 in order to maximize the transmittance. Further, even if the inclination angle of the filter 211 is changed so that the transmittance is maximized, the maximum transmittance at that time is smaller than the maximum transmittance at the optimum wavelength (810 nm).

  For this reason, in the said information acquisition apparatus 1, it is desirable to adjust the temperature of the laser light source 11 with the temperature control element 12 so that the wavelength of the laser beam radiate | emitted from the laser light source 11 may be maintained at the optimal wavelength.

  However, the temperature range that can be adjusted by the temperature control element 12 is limited. For this reason, there are cases where the temperature of the laser light source 11 cannot be adjusted to the temperature at which the laser light having the optimum wavelength is emitted, depending on the ambient temperature around the laser light source 11 being driven or just before the laser light source 11 is driven.

  Therefore, in such a case, the temperature of the laser light source 11 and the filter are set so that the temperature (wavelength) and the inclination angle give the maximum transmittance in the adjustable temperature range, that is, in the adjustable wavelength range. It is necessary to adjust the inclination angle 211. In order to realize this, in this embodiment, a reference table is prepared in advance, and the temperature of the laser light source 11 and the tilt angle of the filter 211 are adjusted based on the reference table.

  FIG. 9A shows a reference table.

  As shown in the figure, the reference table shows a CMOS image corresponding to the detected temperature (horizontal direction) of the temperature sensor 13 when the laser light source 11 is in the lighting state and the tilt angle (vertical direction) of the filter 211 in the tilt direction. The S / N ratio of the detection signal by the sensor 23 is described. This table is based on the laser light source 11, the filter 211, the CMOS image sensor 23, the temperature adjustment element 12, and the temperature sensor 13 shown in FIG. 2 and the temperature actually detected by the temperature sensor 13 and the inclination angle of the filter 211. It is created by measuring the detection signal from the CMOS image sensor 23 while changing.

  In the reference table shown in FIG. 9A, the inclination angle at which the S / N ratio of the detection signal becomes maximum differs for each detection temperature of the temperature sensor 13, that is, the detection temperature of the temperature sensor 13, that is, the wavelength of the laser beam. This is because there is a relationship as shown in FIG. 8B between the inclination angle of the filter 211 and the transmittance.

  In the reference table shown in FIG. 9A, for example, when the detection temperature of the temperature sensor 13 is 30 ° C., the transmittance of the filter 211 of the laser light emitted from the laser light source 11 is maximized. This is when the tilt angle of the filter 211 is 5 °. The temperature detected by the temperature sensor 103 described in the reference table is set to a range that is assumed to be detected by the temperature sensor 103 during actual operation.

  FIG. 9B is a diagram showing the relationship between the ambient temperature around the laser light source 11 when the light is turned on and the detected temperature of the temperature sensor 13 when the laser light source 11 is turned on. S1, S2, and S3 on the vertical axis represent temperatures detected by the temperature sensor 13 when the temperature adjustment by the temperature adjustment element 12 is not performed when the ambient temperature is t1, t2, and t3, respectively. The arrow in the figure schematically shows a range in which the temperature detected by the temperature sensor 13 can be changed by driving the temperature control element 12.

  As shown in the figure, the temperature range that can be detected by the temperature sensor 13 (hereinafter referred to as “detectable range”) when the temperature is adjusted by the temperature control element 12 varies depending on the ambient temperature at that time. For example, when the ambient temperature is t1, the detection range of the temperature sensor 13 when the laser light source 11 is turned on is the arrow range in FIG. 5B centering on S1, and when the ambient temperature reaches t2, the temperature sensor The detection range of 13 shifts to an arrow range centered on S2.

  The temperature of the laser light source 11 in the lighting state changes as the ambient temperature changes. On the other hand, the temperature adjustable range by the temperature control element 12 is limited. Therefore, if the ambient temperature changes, the temperature adjustable range of the laser light source 11 in the lighting state also changes. Thus, when the temperature adjustable range of the laser light source 11 changes, the temperature range (detectable range) that can be detected by the temperature sensor 13 also changes accordingly.

  The CPU 21 obtains a temperature range (detectable range) that can be detected by the temperature sensor 13 during actual operation based on the temperature (atmosphere temperature) detected by the temperature sensor 13 at the start of driving of the laser light source 11. Then, the CPU 21 applies the obtained detectable range to the reference table as a referenceable range (see FIG. 9A). The referenceable range is determined by the circuit setting of the information acquisition apparatus 1 as well as the performance of the temperature control element 24 and the installation environment temperature.

  The CPU 21 detects the detected temperature of the temperature sensor 13 at which the S / N ratio is maximized and the tilt angle of the filter 211, that is, the detected temperature of the temperature sensor 13 at which the transmittance of the filter 211 is maximized, from the reference range thus set. And the inclination angle of the filter 211 is acquired. For example, when a referenceable range is designated as shown in the figure, the highest S / N ratio within the referenceable range is “80”. Therefore, in this case, the CPU 21 acquires the detected temperature (30 ° C.) of the temperature sensor 13 associated with the S / N ratio of 80 and the inclination angle (5 °) of the filter 211 from the reference table. The CPU 21 drives the temperature adjustment element 12 so that the temperature detected by the temperature sensor 13 becomes the acquired sensor temperature, and drives the filter driving unit 200 to match the filter 211 with the acquired inclination angle.

  By setting the temperature detected by the temperature sensor 13 and the tilt angle of the filter 211 in this way, the information acquisition device 1 is adjusted so that the light projected onto the target area can be received most efficiently at the ambient temperature at that time. can do.

  FIG. 10 is a flowchart showing temperature control of the laser light source 11 and tilt angle control of the filter 211. The processing flow of FIG. 6 is started when the information acquisition apparatus 1 is turned on.

  First, the CPU 21 obtains the detection temperature (atmosphere temperature) of the temperature sensor 13 based on the detection signal output from the temperature sensor 13 (S1). Next, the CPU 21 refers to the reference table held in the memory 36 and determines whether the detected temperature of the temperature sensor 13 obtained in S1 is within the range of the sensor temperature described in the reference table ( S2). When the detected temperature is within the sensor temperature range of the reference table (S2: YES), the CPU 21 determines the referenceable range in the reference table based on the detected temperature of the temperature sensor 13 (S3). When the detected temperature is not within the range of the sensor temperature in the reference table (S2: NO), the operation in the information acquisition device is terminated as an abnormality.

  Next, the CPU 21 obtains the target temperature of the temperature sensor 13 and the target inclination angle of the filter 211 when the S / N ratio becomes maximum within the referable range of the reference table (S4). Subsequently, the CPU 21 starts "temperature control of the laser light source" and "filter inclination angle control" based on the obtained target temperature and target inclination angle (S5). The “laser light source temperature control” and the “filter tilt angle control” are performed in parallel with the processing flow of FIG.

  FIG. 11A is a flowchart showing “temperature control of laser light source”.

  The CPU 21 determines whether the temperature detected by the temperature sensor 13 matches the target temperature obtained in S4 of FIG. 10 (S11). If it is determined that the temperature detected by the temperature sensor 13 matches the target temperature (S11: YES), the process returns to S11. If it is determined that the detected temperature of the temperature sensor 13 does not match the target temperature (S11: NO), the temperature adjustment element 12 is driven so that the detected temperature of the temperature sensor 13 becomes the target temperature, and the process proceeds to S11. Returned.

  Thus, even after the detected temperature of the temperature sensor 13 reaches the target temperature, the temperature sensor 13 continues to be controlled so that the detected temperature is maintained at the target temperature.

  FIG. 11B is a flowchart showing “filter inclination angle control”.

  The CPU 21 drives the filter drive unit 200 via the motor drive circuit 35 to match the inclination angle of the filter 211 with the target inclination angle obtained in S4 of FIG. 10 (S21). The tilt angle of the filter 211 is detected by the number of steps of the stepping motor 230 from the reference position. The reference position is set to a position where the filter 211 is perpendicular to the Z axis. By driving the stepping motor 230 by the number of steps corresponding to the target inclination angle from the reference position, the stepping motor 230 is matched with the target inclination angle.

  Next, the CPU 21 determines whether or not the temperature detected by the temperature sensor 13 has reached the target temperature obtained in S4 of FIG. 10 (S22). That is, it is determined whether or not YES is determined in the determination process of S11 of FIG. If it is determined that the temperature detected by the temperature sensor 13 has reached the target temperature (S22: YES), the process proceeds to S23. If it is determined that the temperature detected by the temperature sensor 13 has not reached the target temperature (S22: NO), the process is on standby. As a result, the subsequent processing is advanced only when the detected temperature of the temperature sensor 13 and the inclination angle of the filter 211 reach the target value.

  Next, the CPU 21 acquires the output value of the CMOS image sensor 23 at the target tilt angle of the filter 211, and further tilts the filter 211 forward and backward by one step, and the output value of the CMOS image sensor 23 at each tilt angle. Is acquired (S23). In order to tilt the filter 211 forward and backward by one step, the stepping motor 230 may be driven by one pulse in different rotational directions.

  Of the three output values obtained in S23, when the output value of the CMOS image sensor 23 at the target inclination angle of the filter 211 is the maximum (S24: YES), the inclination angle of the filter 211 is set as the target inclination angle. (S25), the process ends. When the output value at the target tilt angle of the filter 211 is not the maximum (S24: NO), the process proceeds to S25. Subsequently, among the output values of the CMOS image sensor 23 before and after the target tilt angle of the filter 211 obtained in S23, the output value when the filter 211 is tilted one step forward is the maximum (S25: YES), the process proceeds to S27. When the output value when the filter 211 is tilted backward by one step is maximum (S25: NO), the process proceeds to S30.

  In S27, the filter 211 is tilted by one step further forward from the tilt angle that was tilted one step before the target tilt angle in S23 by the stepping motor 230. Subsequently, the CPU 21 determines whether the output value of the CMOS image sensor 23 after tilting the filter 211 is increased from the output value at the tilt angle tilted one step before the target tilt angle ( S28). If it is determined that the output value has increased (S28: YES), the process returns to S27, where the filter 211 is further tilted forward by one step, and whether the output of the CMOS image sensor 23 has increased before and after the filter 211 is tilted. Is determined. The processes of S27 and S28 are repeated until the determination in S28 is NO. When it is determined in S28 that the output value has not increased (S28: NO), the filter 211 is inclined backward by one step (S29), and this inclination angle is the inclination of the filter 211 during actual operation. Set to the corner. Thus, the tilt angle control process is completed.

  In S30 to S32, as in S27 to S29, the filter 211 continues to be tilted backward while the output value of the CMOS image sensor 23 increases. That is, the filter 211 is tilted backward by one step until it is determined that the output of the CMOS image sensor 23 is decreased by tilting the filter 211 backward by one step (S31: NO). If it is determined in S31 that the output value has not increased (S31: NO), the filter 211 is tilted forward by one step (S32), and this tilt angle is the tilt of the filter 211 during actual operation. Set to the corner. Thus, the tilt angle control process is completed.

  In this way, the tilt angle of the filter 211 is adjusted to a tilt angle at which a more optimal output value is obtained in the vicinity of the target tilt angle. Thereby, the accuracy of the information acquisition device 1 can be maintained high.

  As described above, according to the present embodiment, the temperature of the laser light source 11 and the inclination angle of the filter 211 are set so that the transmittance is maximized within the referable range of the reference table. Thereby, since the light quantity received by the CMOS image sensor 23 is increased, the detection accuracy by the information acquisition device 1 can be increased.

  Further, according to the present embodiment, even when the temperature of the laser light source 11 that is turned on changes, the temperature adjustment element 12 suppresses the temperature change of the laser light source 11. Thereby, since the change of the wavelength of the laser beam radiate | emitted from the laser light source 11 is suppressed, it is not necessary to change the inclination angle of the filter 211 largely. Therefore, the back focus necessary for tilting the filter 211 can be shortened, and the information acquisition apparatus 1 can be downsized. In this case, since the inclination angle of the filter 211 is constant within the referable range, the control of the filter 211 can be simplified.

<Embodiment 2>
In the configuration of the first embodiment, the refractive action of the filter 211 with respect to the transmitted light changes due to the change in the tilt of the filter 211. For this reason, the optical path of the light after passing through the filter 211 changes in a direction parallel to the Y axis in FIG. 2 in accordance with the change in the tilt of the filter 211, and the light irradiation area on the CMOS image sensor 23 is changed. It changes in the Y-axis direction. As described above, when the light irradiation region changes, the accuracy of the three-dimensional distance information deteriorates, and as a result, the detection accuracy in the object detection unit 31a decreases. The present embodiment solves this problem.

  FIG. 12 is a diagram illustrating a main part of the configuration of the information acquisition apparatus 1 according to the present embodiment. Here, an adjustment plate 241 is added compared to FIG. The adjustment plate 241 is made of a transparent plate having the same shape as the filter 211 and having the same refractive action.

  FIG. 13A is a diagram illustrating the configuration of the actuators 210 and 240. The actuator 240 has substantially the same configuration as the actuator 210. Hereinafter, differences between the actuators 210 and 240 and differences from the actuator of the first embodiment will be described.

  A gear 216 is installed on the shaft 215 of the actuator 210 near the outside of the wall 212b, as shown. A shaft hole formed in the center of the gear 216 is passed through the shaft 215 and fixed. Thus, when the shaft 215 is rotated about the X-axis direction, the gear 216 is rotated about the X-axis direction.

  The shaft 245 of the actuator 240 is shorter than the shaft 215 of the actuator 210 as shown in the figure. The shaft 245 of the actuator 240 is provided with a gear 246 that is the same as the gear 216 near the outside of the wall portion 242b, as shown. A shaft hole formed in the center of the gear 246 is passed through the shaft 245 and fixed. Accordingly, when the gear 246 is rotated about the X-axis direction, the shaft 245 is rotated about the X-axis direction.

  At the time of assembly, the adjustment plate 241 is fitted and attached to a step portion 243b formed on the upper surface of the holder 243 of the actuator 240. The actuators 240 and 210 to which the adjustment plate 241 and the filter 211 are attached are overlapped in the Z-axis direction as shown. At this time, the gear 216 and the gear 246 are fitted to each other.

  FIG. 13B is a diagram illustrating a state in which the actuators 210 and 240 are overlapped. In this state, the filter 211 and the adjustment plate 241 are both parallel to the XY plane.

  When the actuators 210 and 240 are overlapped in this way, when the shaft 215 is rotated, the holder 213 and the gear 245 of the actuator 210 are rotated in different directions. Since the gears 216 and 246 are the same gear, the gear 246 is rotated at the same rotational speed as the gear 216. When the gear 246 is rotated, the shaft 245 is rotated and the holder 243 of the actuator 240 is rotated. Therefore, when the shaft 215 is rotated around the X-axis direction, the filter 211 and the adjustment plate 241 are inclined in the different directions from each other by the same angle in the direction parallel to the YZ plane. FIG. 13C is a diagram showing in detail the configuration of the light receiving module 20 of the information acquisition apparatus 1. Compared to the first embodiment, an actuator 240 is disposed between the actuator 210 and a holding frame (not shown) disposed on the CMOS image sensor 23 as illustrated.

  The shaft 215 of the actuator 210 is fixed by being passed through the shaft hole of the gear 223 as in the first embodiment. Thus, when the stepping motor 230 is driven, the shaft 215 is rotated around the X axis, and the filter 211 and the adjustment plate 241 are inclined in the different directions from each other by the same angle. Will be.

  As described above, according to the present embodiment, the change in the light flux in the Y-axis direction due to the inclination of the filter 211 is canceled by passing through the adjustment plate 241. As a result, light can be always guided to the CMOS image sensor 23 in the same region.

  In the present embodiment, the adjustment plate 241 and the filter 211 are driven by one stepping motor 230, but may be individually driven by another stepping motor.

  In the present embodiment, light is always guided to the same region by the adjustment plate 241 to the CMOS image sensor 23. Instead of arranging the adjustment plate 241, the imaging lens 22 and the CMOS image sensor 23 are replaced by the filter 211. The light may be always guided to the same region by the CMOS image sensor 23 by displacing in the Y-axis direction in accordance with the inclination angle of.

<Embodiment 3>
In the first embodiment, as shown in the flowchart of FIG. 10, the target temperature and the target inclination angle are acquired from the reference table when the information acquisition apparatus 1 is powered on. In the present embodiment, in addition to the acquisition timing of the first embodiment, the target temperature and the target inclination angle are updated based on a temperature sensor that detects the ambient temperature after the information acquisition device 1 is turned on. To.

  FIG. 14 is a diagram showing the configuration of the light source module 10 in detail.

  The light source module 10 of the present embodiment includes the light source module 10 (see FIG. 6) shown in the first embodiment and the temperature sensor 18 installed in the light source module 10. The temperature sensor 18 is installed on the inner wall of the cover 15, detects the ambient temperature (atmosphere temperature) of the laser light source 11, and outputs a detection signal to the CPU 21.

  FIG. 15A is a flowchart showing the update control of the target temperature and the target inclination angle. Note that the processing flow of FIG. 10A is performed in parallel with the processing of FIG. 10A after the processing flow at the start of the operation of FIG.

  First, the CPU 21 starts counting elapsed time (S41). Subsequently, the CPU 21 determines whether the elapsed time has exceeded a predetermined time T (S42). The predetermined time T is set to 1 hour, for example. In addition, the predetermined time T may be set as appropriate to the extent that the accuracy of the information acquisition device 1 does not decrease.

  When it is determined that the elapsed time exceeds the predetermined time T (S42: YES), the CPU 21 obtains the ambient temperature of the laser light source 11 based on the detection signal output from the temperature sensor 18 (S43). Subsequently, the CPU 21 refers to the reference table held in the memory 36, and determines whether or not the detected temperature of the temperature sensor 18 obtained in S43 is within the sensor temperature range described in the reference table ( S44). When the detected temperature is within the sensor temperature range of the reference table (S44: YES), the CPU 21 resets the referenceable range in the reference table based on the detected temperature of the temperature sensor 18 (S45). When the detected temperature is not within the range of the sensor temperature of the reference table (S44: NO), the operation in the information acquisition device is terminated as an abnormality.

  Next, the CPU 21 obtains the target temperature of the temperature sensor 13 and the target inclination angle of the filter 211 when the S / N ratio becomes maximum in the resettable referenceable range (S46). Then, CPU21 updates control of the temperature control element 12 and the actuator 210 using the acquired target temperature and target inclination angle (S47). That is, the target temperature used in FIG. 11A is set to the target temperature obtained in S46, and the processing flow in FIG. 11A is continued. Further, the processing flow of FIG. 11B is started based on the target inclination angle obtained in S46.

  Thus, in the present embodiment, every time the predetermined time T elapses, the referenceable range is reset based on the ambient temperature at that time. Then, the temperature of the laser light source 11 and the tilt angle of the filter 211 are adjusted to the sensor temperature and tilt angle having the largest S / N ratio within the resettable referenceable range. Thereby, even if the atmospheric temperature changes with the passage of time, the temperature of the laser light source 11 and the inclination angle of the filter 211 can be set to the sensor temperature and the inclination angle most suitable for the atmospheric temperature at that time.

  In addition, it may replace with the flowchart of Fig.15 (a), or may perform the process by the flowchart of FIG.15 (b) with the flowchart of Fig.15 (a).

  Referring to FIG. 15B, in S51, the CPU 21 determines whether or not the temperature adjustment element 12 can adjust the detected temperature to the target temperature. Note that the temperature adjustment by the temperature adjustment element 12 is impossible, such as when the drive current of the temperature adjustment element 12 is just before the maximum value, or even if the temperature adjustment element 12 is driven, the detected temperature becomes the target temperature. The case where it does not reach is included.

  If it is determined that the temperature adjustment by the temperature control element 12 is impossible (S51: NO), the process proceeds to S52. The processing after S52 is performed in the same manner as the processing after S43 in FIG.

  In this way, even if the reference temperature range is acquired and before the predetermined time T elapses, if the ambient temperature changes and temperature adjustment becomes impossible, the referenceable range is quickly reset, so that more appropriate In addition, the temperature of the laser light source 11 and the tilt angle of the filter 211 can be adjusted.

  When the temperature sensor 18 that detects the ambient temperature is installed in addition to the temperature sensor 13 as in the present embodiment, in the processing flow of FIG. 10 performed at the start of operation, based on the detected temperature of the temperature sensor 18. Thus, the referable range at the start of the operation may be determined. That is, in S1 of FIG. 10, the temperature detected by the temperature sensor 18 may be obtained instead of the temperature sensor 13.

  In this embodiment, when the control of the temperature control element 12 and the actuator 210 is updated in S47 of FIG. 15A and S56 of FIG. 15B, respectively, FIG. 11A and FIG. However, instead of this, the processing flow shown in FIGS. 16A and 16B may be executed. FIG. 16A is the same processing flow as FIG. 11A, and FIG. 16B is a processing flow consisting only of S21 of FIG. 11B. In this way, although the tilt angle of the filter 211 is not finely adjusted in the vicinity of the target tilt angle, the control of the CPU 21 can be simplified.

<Embodiment 4>
In FIG. 15B, when the detected temperature cannot be adjusted to the target temperature by the temperature control element 12, the ambient temperature is acquired again, and the referenceable range is reset based on the reference temperature. In the present embodiment, the referable range is reset without acquiring the ambient temperature again.

  FIG. 17A is a flowchart showing the update control of the target temperature and the target inclination angle. Note that the processing flow in FIG. 10A is performed in parallel with the processing flow in FIG. 10A after the processing flow at the start of the operation in FIG.

  First, the CPU 21 determines whether the detected temperature can be adjusted to the target temperature by the temperature control element 12 (S61). If it is determined in S61 that the temperature adjustment by the temperature control element 12 is impossible (S61: NO), it is determined whether or not the referenceable range can be shifted in the temperature adjustable direction on the reference table (S62). ). Here, if it is determined that it is impossible to shift the referable range (S62: NO), the operation in the information acquisition apparatus is terminated as an abnormality.

  When it is determined that the referenceable range can be shifted (S62: YES), the CPU 21 shifts the referenceable range by one in the temperature adjustable direction (S63). Thereby, a new referable range is reset.

  Here, the shift direction of the referenceable range in S63 is determined based on the control state of the temperature control element 12. For example, when it is determined that the detected temperature cannot be adjusted to the target temperature due to the drive current reaching the maximum value during the heating control of the temperature control element 12, the referenceable range is as shown in FIG. In the reference table shown in FIG. When it is determined that the detected temperature cannot be adjusted to the target temperature due to the drive current reaching the maximum value during cooling of the temperature control element 12, the referenceable range is 1 in the left direction on the reference table. Shifted one by one. Thereafter, in S64 and S65, the same processing as S46 and S47 in FIG.

  FIG. 17B is a diagram showing a state in which the referenceable range is shifted by one in the right direction from the state of FIG. 9A by the processing of FIG.

  As shown in the figure, the referable range is shifted from the range of 30 ° C. to 50 ° C. in FIG. Along with this, the sensor temperature and the inclination angle at which the S / N ratio becomes maximum within the referable range of FIG. 9A also change. That is, in the referenceable range of FIG. 9A, the maximum S / N ratio is 80 when the sensor temperature is 30 ° C. and the inclination angle is 5 °, but in the referenceable range of FIG. When the sensor temperature is 40 ° C. and the tilt angle is 10 °, the S / N ratio is 75, which is the maximum.

  When the referenceable range is reset as described above, the temperature of the laser light source 11 and the tilt angle of the filter 211 can be adjusted more appropriately, as in the third embodiment.

  Further, when the referenceable range is reset as shown in FIG. 16A, the referenceable range can be reset without using the temperature sensor 18 that acquires the ambient temperature. For this reason, also in the first and second embodiments, if the referenceable range is reset as shown in FIG. 16A, the temperature of the laser light source 11 and the tilt angle of the filter 211 can be adjusted more appropriately.

  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 laser beam is spread and projected onto the target area, but the target area may be scanned with the laser beam. In this case, a scanning mechanism using a mirror (for example, Japanese Patent Application Laid-Open No. 2008-102026) or a scanning mechanism using a lens (for example, Japanese Patent Application Laid-Open No. 2006-308558) can be used as laser beam scanning means. . If the scanning position of the laser beam can be detected, a photodetector that can detect the amount of received light can be used instead of the CMOS image sensor.

  In the configuration example of FIG. 11, the optical path correction is performed by tilting the adjustment plate 15 and the filter 211 in the opposite directions. However, other optical path correction elements such as a diffraction element whose diffraction action is changed by a control signal. Can also be used.

  In the above embodiment, a laser light source is used as the light source. However, a narrow band LED can be used instead, and a high-speed responsive CCD image sensor is used instead of the CMOS image sensor 14. You can also. Furthermore, the information acquisition device 1 and the information processing device 2 may be integrated.

  Further, in the reference tables (see FIGS. 9A and 17B) of the above embodiment, the S / N ratios at the inclination angles of the plurality of filters 211 corresponding to the temperature detected by the temperature sensor 13 are shown. Although stored, only the inclination angle that maximizes the S / N ratio at each sensor temperature may be stored.

  Further, the “filter inclination angle control” (see FIG. 11B) shown in the first embodiment is executed only once after the information acquisition apparatus 1 is turned on. Similarly to “control”, the tilt angle of the filter 211 may be repeatedly controlled so that the optimum tilt angle is maintained even after the tilt angle of the filter 211 is once adjusted to the optimum tilt angle.

  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.

1 Information acquisition device 10 Light source module (projection optical system)
11 Laser light source
12 Temperature control element 13, 18 Temperature sensor 23 CMOS image sensor (light receiving element)
31 CPU (control unit)
200 Filter driver (actuator)
210 Actuator 211 Filter

Claims (6)

In an information acquisition device that acquires information on a target area using light,
A light source that emits light of a predetermined wavelength band;
A temperature control element for adjusting the temperature of the light source;
A temperature sensor for detecting the temperature of the light source;
A projection optical system that projects the light emitted from the light source toward the target area;
A filter for transmitting the reflected light reflected from the target area;
A light receiving element that receives the reflected light transmitted through the filter and outputs a signal;
An actuator for changing an inclination angle of the filter with respect to the reflected light;
A controller that controls the temperature adjustment element and the actuator so that the amount of light received by the light receiving element is maximized within a temperature range of the light source that can be set by the temperature adjustment element;
An information acquisition apparatus characterized by that. The information acquisition device according to claim 1,
The control unit includes a table in which information on the maximum transmittance is described in association with the temperature detected by the temperature sensor and the inclination angle of the filter that gives the maximum transmittance at the temperature. Controlling the temperature control element and the actuator based on
An information acquisition apparatus characterized by that. The information acquisition device according to claim 2,
The control unit determines a reference range of the table based on an ambient temperature, acquires the temperature and the inclination angle at which the maximum transmittance is maximum within the reference range, and detects the temperature by the temperature sensor. The temperature control element and the actuator are controlled such that the temperature and the inclination angle of the filter are the temperature and the inclination angle acquired from the table,
An information acquisition apparatus characterized by that. In the information acquisition device according to claim 3,
The control unit, after controlling the tilt angle of the filter to be the tilt angle acquired from the table, finely adjust the tilt angle of the filter so that the transmittance of the filter is maximized,
An information acquisition apparatus characterized by that. In the information acquisition device according to claim 3 or 4,
The control unit re-determines the reference range of the table when the temperature detected by the temperature sensor cannot be the temperature acquired from the table, and the reference after the re-determination Controlling the temperature control element and the actuator based on a range;
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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