JP2013181968A - Optical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical instrument capable of achieving distance measurement and object identification without spoiling high speed response and with a simple configuration.SOLUTION: An optical instrument 100 includes a light emitting part 10, a light receiving part 20, storage means, identifying means, and distance calculating means. The light emitting part 10 has a first light source configured to emit light of first wavelength and a second light source configured to emit light of second wavelength different from the first wavelength. The light receiving part 20 receives light emitted from light emitting means and reflected by a measurement target. The identifying means identifies, as a measurement target, an object of reflection spectrum that indicates spectral reflectance corresponding to the first light intensity of the light of first wavelength and the second light intensity of the light of second wavelength, which are included in the reflected light. The distance calculating means calculates a distance between the optical instrument and measurement target on the basis of the difference between the time at which the emission light is emitted and the time at which the reflected light is received and the light propagation velocities thereof.

Description

  The present invention relates to an optical device.

  Devices that measure the distance to a measurement object by irradiating light are known. For example, radar devices that detect the presence and position of a reflecting object by irradiating a transmission wave such as a light wave and a millimeter wave and detecting the reflected wave are known (for example, Patent Document 1 and Patent Document 2). reference). In Patent Document 1 and Patent Document 2, a reflecting object is irradiated with a laser beam based on the time until the voltage signal corresponding to the received light intensity of the reflected light becomes equal to or higher than a reference voltage and the light propagation speed. It is disclosed that the distance to is calculated.

  In addition, a technique for performing object identification by performing spectrum analysis of reflected light is also known (see, for example, Patent Documents 3 to 6). Patent Documents 3 to 6 disclose a method of acquiring reflected light as an image signal and performing object identification using image analysis processing.

  Here, in recent years, it has been required that an optical device that performs distance measurement also performs object identification. As an object identification method, methods using image analysis processing are disclosed in Patent Documents 3 to 6 described above. However, it is necessary to use an image with a relatively high resolution for image analysis processing, which is useful for optical device applications. It was necessary to prepare a suitable imaging system individually. In addition, the image analysis process takes a long time and is difficult to apply to an optical apparatus that requires a high-speed response.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an optical device that can realize distance measurement and object identification with a simple configuration without impairing high-speed response.

  In order to solve the above-described problems and achieve the object, the present invention includes a light emitting means, a light receiving means, a storage means, an identification means, and a distance calculation means. The light emitting means includes a first light source that emits light of a first wavelength, and a second light source that emits light of a second wavelength different from the first wavelength. The light receiving means receives the reflected light from the measurement object of the emitted light including the first wavelength light and the second wavelength light emitted from the light emitting means. The storage means stores in advance the reflection spectrum of the object. The identifying means uses, as the measurement object, an object having the reflection spectrum indicating the spectral reflectance according to the first light intensity of the first wavelength and the second light intensity of the second wavelength, which is included in the reflected light. Identify. The distance calculation means calculates the distance between the optical device and the measurement object based on the difference between the light emission time of the emitted light and the light reception time of the reflected light and the light propagation speed.

  According to the present invention, there is an effect that it is possible to provide an optical apparatus capable of realizing distance measurement and object identification with a simple configuration without impairing high-speed response.

FIG. 1 is a block diagram schematically showing the optical device of the present embodiment. FIG. 2 is a schematic diagram showing a light emitting part. FIG. 3 is a schematic diagram illustrating an example of a scanning pattern of the light L1 emitted from the light emitting unit. FIG. 4 is a schematic diagram illustrating an example of a scanning pattern of the light L1 and the light L2 emitted from the light emitting unit. FIG. 5 is a block diagram illustrating the configuration of the light receiving unit and the functional configuration of the calculation unit. FIG. 6 is a schematic diagram illustrating an example of a waveform indicating a voltage signal corresponding to the light intensity of the reflected light L3. FIG. 7 is a schematic diagram illustrating an example of a waveform indicating a voltage signal corresponding to the wavelength component of the light L1 and a waveform indicating a voltage signal corresponding to the wavelength component of the light L2 obtained from the reflected light L3 from the overlapping region. is there. FIG. 8 is a schematic diagram illustrating an example of a reference reflection spectrum. FIG. 9 is a flowchart showing the procedure of the distance calculation process. FIG. 10 is a flowchart illustrating the procedure of the object identification process. FIG. 11 is a schematic diagram illustrating an example of a configuration of a light emitting unit including a multiplexing member. FIG. 12 is a schematic diagram illustrating an example of a light emitting unit including a hologram element. FIG. 13 is a schematic diagram illustrating an example of a configuration of a light emitting unit including a polarizing element.

  Hereinafter, an optical device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram schematically showing an optical device 100 of the present embodiment.

  The optical device 100 includes a light emitting unit 10, a light receiving unit 20, a calculating unit 30, a display unit 40, and an operation unit 50.

  The light emitting unit 10 emits light toward the measurement object. The light emitting unit 10 includes a plurality of light sources that emit light having different wavelengths. For this reason, the light emission part 10 radiate | emits multiple types of light from which a wavelength differs. The light receiving unit 20 receives the reflected light from the measurement object of the emitted light (hereinafter sometimes simply referred to as light) emitted from the light emitting unit 10. The calculation unit 30 detects the light intensity of the reflected light, calculates the distance from the optical device 100 to the measurement object, and identifies the measurement object.

  The display unit 40 displays various information such as the distance to the measurement object and the identification result of the measurement object P. Examples of the display unit 40 include known display devices such as an LCD (Liquid Crystal Display).

  The operation unit 50 receives various operation instructions from the user. Examples of the operation unit 50 include voice recognition using a mouse and a microphone, buttons, a remote controller, and a keyboard.

  Next, details of the light emitting unit 10, the light receiving unit 20, and the calculating unit 30 of the optical device 100 will be described.

  FIG. 2 is a schematic diagram showing the light emitting unit 10. The light emitting unit 10 includes a lighting controller 14, an optical unit 11, an optical unit 12, and a light deflecting device 13.

  The optical unit 11 includes a light source 11A, a collimating lens 11B, an aperture 11C, and a deflection prism 11D. Specifically, the optical unit 11 includes a collimator lens 11B, an aperture 11C, and a deflection prism 11D in order from the light source 11A side.

  The light source 11A (first light source) is a light source that emits light L1 having a predetermined specific wavelength (first wavelength). The light source 11A emits light having a wavelength different from that of the other light sources provided in the light emitting unit 10 (light source 12A (second light source) in the present embodiment). As the light source 11A, for example, a semiconductor laser that emits laser light, an LED (Light Emitting Diode) element, or the like is used.

  The collimating lens 11B collimates (in parallel) the light L1 emitted from the light source 11A and converts it into a parallel light beam. The aperture 11C functions as an aperture that adjusts the amount of light passing therethrough. Specifically, the aperture 11 </ b> C adjusts the spot diameter so that the spot diameter of the light L <b> 1 irradiated from the optical unit 11 to the measurement object P matches the spot diameter of the light emitted from the optical unit 12. . The aperture adjustment value by the aperture 11C is set in advance so as to satisfy the above conditions. The deflecting prism 11D deflects the light L1 emitted from the light source 11A and passed through the collimating lens 11B and the aperture 11C so as to be coupled to the light deflecting device 13.

  The optical unit 12 includes a light source 12A, a collimating lens 12B, and an aperture 12C. Specifically, the optical unit 12 includes a collimator lens 12B and an aperture 12C in order from the light source 12A side.

  The light source 12A (second light source) is a light source that emits light L2 having a predetermined specific wavelength (second wavelength), and is another light source (light source 11A in the present embodiment) provided in the light emitting unit 10. It emits light with a different wavelength. Examples of the light source 12A include a semiconductor laser that emits laser light and an LED element.

  The collimating lens 12B collimates (in parallel) the light L2 emitted from the light source 12A and converts it into a parallel light beam. The aperture 12C functions as an aperture that adjusts the amount of light L2 that passes therethrough. Specifically, the aperture 12 </ b> C adjusts the spot diameter so that the spot diameter of the light L <b> 2 irradiated from the optical unit 12 to the measurement object P matches the spot diameter of the light L <b> 1 emitted from the optical unit 11. . Note that the aperture adjustment value by the aperture 12C is set in advance so as to satisfy the above condition.

  Note that the wavelengths of the light (light L1, light L2) emitted from each of the light source 11A and the light source 12A may be different from each other as described above. As the wavelength of the light (light L1, light L2) emitted from each of the light source 11A and the light source 12A, for example, the wavelength of the light L1 emitted from one light source (for example, the light source 11A) is 1.3 μm, and the other light source It is preferable that the wavelength of the light L2 emitted from (for example, the light source 12A) is 1.5 μm.

  The light emitting unit 10 includes at least two types of light sources (light source 11A, light source 12A) as light sources that emit light having different wavelengths, and one light source 11A emits light L1 having a wavelength of 1.3 μm, and the other light source 12A. Emits light with a wavelength of 1.5 μm, it is possible to perform identification based on the moisture content of the measurement object P in the calculation unit 30 described later.

  The wavelengths of the light (light L1, light L2) emitted from each of the light source 11A and the light source 12A are not limited to the above values. Specifically, when the light emitting unit 10 includes two types of light sources, the wavelength of the light L1 emitted from one light source (for example, the light source 11A) is in the range of 1000 nm to 1350 nm, and the other light source. The wavelength of the light L2 emitted from (for example, the light source 12A) is preferably in the range of 1400 nm to 1600 nm.

  The light emitting unit 10 includes at least two types of light sources (light source 11A, light source 12A) as light sources that emit light of different wavelengths, and one light source 11A emits light L1 in the wavelength range of 1000 nm to 1350 nm, while the other When the light source 12A emits light L2 having a wavelength in the range of 1400 nm to 1600 nm, object calculation based on the moisture content of the measurement target P can be performed in the calculation unit 30 described later.

  As described above, the light emitting unit 10 includes at least two types of light sources (light source 11A and light source 12A) as light sources that emit light of different wavelengths, and the wavelengths of light emitted from the light source 11A and the light source 12A are described above. Adjustment to the range is also preferable from the viewpoint of reducing the amount of noise (S / N ratio) with respect to the voltage signal according to the light intensity used in the calculation unit 30.

  In addition, when placing importance on the viewpoint of implementation at a lower cost, the light emitting unit 10 includes at least two types of light sources (light source 11A and light source 12A) as light sources that emit light of different wavelengths, and one of the light sources 11A preferably emits light L1 in the wavelength range of 780 nm to 900 nm, and the other light source 12A emits light L2 in the wavelength range of 940 nm to 990 nm.

  The lighting controller 14 controls the light source 11A and the light source 12A. Specifically, the lighting controller 14 controls the light source 11A and the light source 12A to perform pulse driving at regular time intervals. Further, the lighting controller 14 controls the light source 11A and the light source so that the spot positions of the light L1 and the light L2 coincide in the overlapping region of the scanning region of the light source 11A by the light L1 and the scanning region of the light source 12A by the light L2. The phase difference of 12A lighting is adjusted in advance. In addition, a scanning area | region shows the area | region where each of light L1 and L2 radiate | emitted from each of the light source 11A and the light source 12A is irradiated. Further, the overlapping region indicates a region where the scanning region by the light L1 emitted from the light source 11A and the scanning region by the light L2 emitted from the light source 12A overlap. The details of these scanning areas and overlapping areas will be described later.

  The light deflecting device 13 deflects the light L1 and the light L2 emitted from the optical unit 11 and the optical unit 12. In the present embodiment, the optical deflecting device 13 is a biaxial deflecting mirror having a reflecting surface that tilts (inclins the optical axis) in directions orthogonal to each other. That is, the optical deflecting device 13 performs deflection in each of the X-axis direction and the Y-axis direction (two directions orthogonal to each other in a horizontal plane orthogonal to the vertical direction (Z-axis direction)).

  Each of the light L1 emitted from the optical unit 11 and the light L2 emitted from the optical unit 12 is incident on the mirror tilt center position on the reflection surface of the light deflector 13. The position of the light deflector 13 is adjusted in advance so that the incident positions of the light L1 and the light L2 are the mirror tilt center position on the reflection surface.

  The light L1 emitted from the optical unit 11 and the light L2 emitted from the optical unit 12 are deflected by the light deflecting device 13 and emitted to the outside of the light emitting unit 10 and the optical device 100 to reach the measurement object P. .

  In the light emitting section 10 configured as described above, the light L1 emitted from the light source 11A is converted into a parallel light beam by passing through the collimating lens 11B, and then the spot diameter is adjusted by the collimating lens 11B, so that the deflecting prism. The light is deflected by 11D and reaches the light deflecting device 13. The light L2 emitted from the light source 12A is converted into a parallel light beam by passing through the collimating lens 12B, and then the spot diameter is adjusted by the collimating lens 12B to reach the light deflecting device 13. Then, the light L1 and the light L2 deflected by the light deflecting device 13 are emitted toward the outside of the light emitting unit 10 (optical device 100).

  Here, as described above, the optical deflecting device 13 tilts in directions orthogonal to each other. The horizontal axis represents time, and the vertical axis represents the tilt angle (optical axis tilt). Then, each of the light L1 and the light L2 incident on the optical deflecting device 13 is driven in a triangular wave in the θz direction (vertical direction) and is driven in a sawtooth wave in the horizontal direction (direction orthogonal to the vertical direction). Further, as described above, the light sources 11A and the light sources 12A are pulse-driven by the lighting controller 14 at regular time intervals.

  FIG. 3 is a schematic diagram illustrating an example of a scanning pattern of the light L1 emitted from the light emitting unit 10. A biaxial deflecting mirror is used for the light deflecting device 13, and the light source 11A is pulse-driven. Then, as shown in FIG. 3, the scanning area by the light L <b> 1 emitted from the light source 11 </ b> A has a rectangular shape shown in the scanning area 111. Then, the scanning spot 110 of the light L1 emitted from the light source 11A is scanned in an S shape at regular distance intervals by the light deflector 13 (see scanning spots 110A to 110C in FIG. 3).

  Similarly, with respect to the scanning pattern of the light L2 emitted from the light emitting unit 10, the scanning region by the light L2 emitted from the light source 12A has a rectangular shape, and the scanning spot by the light L2 scans in an S shape at regular intervals.

  For this reason, when the measurement object P is positioned on each spot 110, reflected light from the measurement object P is generated by at least one of the light L1 and the light L2, and the light receiving unit 20 transmits the reflected light from the measurement object P. Receive light.

  Here, as shown in FIG. 2, there is a deflection angle difference θA at the time of emission from the optical deflector 13 between the light L1 emitted from the optical unit 11 and the light L2 emitted from the optical unit 12 (see FIG. 2). ) Exists. For this reason, a region that does not partially overlap occurs in the scanning region by the light L1 and the scanning region by the light L2.

  FIG. 4 is a schematic diagram illustrating an example of a scanning pattern of the light L1 and the light L2 emitted from the light emitting unit 10. As illustrated in FIG. As shown in FIG. 4, the scanning area by the light L <b> 2 emitted from the light source 12 </ b> A has a rectangular shape shown in the scanning area 112. Then, the scanning spot 120 on the measurement object P of the light L2 emitted from the light source 12A is scanned in an S-shape at regular distance intervals by the light deflector 13 (see scanning spots 120A to 120B in FIG. 4). .

  Then, due to the deflection angle difference θA at the time of emission from the optical deflecting device 13, the scanning region 111 by the light L1 and the scanning region 112 by the light L2 overlap in the overlapping region 113, and other than the overlapping region 113 are non-overlapping. .

  As described above, the light source 11A and the light source 12A are lit at the same interval by the lighting controller 14. Further, the lighting controller 14 adjusts in advance the phase difference of lighting of the light source 11A and the light source 12A so that the spot positions of the light L1 and the light L2 coincide in the overlapping region 113.

  For this reason, the light receiving unit 20 receives reflected light from the same position of the same measurement object P by both the light L1 from the optical unit 11 (light source 11A) and the light L2 from the optical unit 12 (light source 12A). can do. However, the timing at which the light receiving unit 20 receives the reflected light from the same position (the same scanning spot) of the same measurement object P by the light L1 from the light source 11A and the light L2 from the light source 12A is slightly increased. A time difference occurs. For this reason, in this Embodiment, it demonstrates on the assumption that the scanning speed of the optical apparatus 100 is sufficiently quick with respect to the moving speed of the measuring object P. FIG.

  Next, details of the light receiving unit 20 and the calculating unit 30 will be described. FIG. 5 is a block diagram illustrating the configuration of the light receiving unit 20 and the functional configuration of the calculation unit 30.

  The light receiving unit 20 receives the reflected light L3 of the light (light L1 and light L2) emitted from the light emitting unit 10 by the measurement object P. As shown in FIG. 5, the light receiving unit 20 includes a light receiving unit 22. The light receiving unit 22 includes a wavelength filter 22A, a condenser lens 22B, and a light receiver 22C in order from the light incident side.

  The wavelength filter 22A selectively transmits the wavelength component of the light L1 emitted from the light source 11A and the wavelength component of the light L2 emitted from the light source 12A among the received reflected light L3. The condensing lens 22B condenses the reflected light L3 that has passed through the wavelength filter 22A and optically couples it to the light receiving surface of the light receiver 22C.

  The light receiver 22C receives the reflected light L3 transmitted through the wavelength filter 22A and the condenser lens 22B. The light receiver 22C photoelectrically converts the received reflected light L3 and outputs a voltage signal corresponding to the light intensity of the received reflected light L3 to the calculating unit 30. A known photoelectric conversion device may be used as the light receiver 22C. In addition, as the light receiver 22C, one having sufficient intensity linearity in the intensity range of the received reflected light L3 is used.

  FIG. 6 is a schematic diagram illustrating an example of a waveform indicating a voltage signal output from the light receiver 22C and corresponding to the light intensity of the received reflected light L3. As illustrated in FIG. 6, the light receiver 22 </ b> C outputs a voltage signal indicated by the waveform 42 to the calculation unit 30 according to the light intensity of the received reflected light L <b> 3.

  When the reflected light L3 is received from the overlapping region 113 between the scanning region 111 of the light L1 and the scanning region 112 of the light L2, the light receiver 22C receives a voltage signal corresponding to the light intensity of the wavelength component of the light L1, And a voltage signal including both the voltage signal corresponding to the light intensity of the wavelength component of the light L2 is output to the calculation unit 30.

  FIG. 7 shows a waveform indicating the voltage signal corresponding to the wavelength component of the light L1 and the voltage signal corresponding to the wavelength component of the light L2 obtained from the reflected light L3 from the overlapping region 113, which is output from the light receiver 22C. It is a schematic diagram which shows an example of a waveform. As shown in FIG. 7, when the received reflected light L3 includes both the wavelength component of the light L1 and the wavelength component of the light L2, the light receiver 22C uses the wavelength of the light L1 included in the reflected light L3. A voltage signal corresponding to the light intensity of the component (see waveform 44) and a voltage signal corresponding to the light intensity of the wavelength component of the light L2 included in the reflected light L3 (refer to waveform 46) are output to the calculating unit 30. .

  Returning to FIG. 5, the calculation unit 30 includes a received light signal processing unit 32, a distance calculation unit 34, and an object identification unit 36.

  The received light signal processing unit 32 receives a voltage signal corresponding to the light intensity of the reflected light L3 from the light receiver 22C. The received light signal processing unit 32 outputs the received voltage signal to the distance calculation unit 34.

The received light signal processing unit 32 also has a waveform 44 indicated by a voltage signal corresponding to the light intensity of the wavelength component of the light L1, from a waveform indicated by the voltage signal corresponding to the light intensity of the reflected light L3 received from the light receiver 22C. The peak intensity (maximum light intensity) P _L1 (see FIG. 7) is extracted. The received light signal processing unit 32 also has a waveform 46 indicated by a voltage signal corresponding to the light intensity of the wavelength component of the light L2 from a waveform indicated by the voltage signal corresponding to the light intensity of the reflected light L3 received from the light receiver 22C. The peak intensity (maximum light intensity) P _L2 (see FIG. 7) is extracted. Then, the received light signal processing unit 32 outputs the extracted peak intensity P _L1 and peak intensity P _L2 to the object identification unit 36.

  The distance calculation unit 34 receives a voltage signal corresponding to the light intensity of the reflected light L3 from the light reception signal processing unit 32. Then, the distance calculation unit 34 calculates the distance between the optical device 100 and the measurement object P based on the voltage signal received from the received light signal processing unit 32.

  Specifically, the distance calculation unit 34 includes a memory 34A and a timer 34B. The memory 34A stores a threshold value E1 of the received light intensity in advance. The threshold value E1 of the received light intensity is a threshold value for measuring timing for starting time calculation, and an arbitrary value is set in advance. The memory 34 </ b> A stores the time when light irradiation is started from the light sources (the light source 11 </ b> A and the light source 12 </ b> A) provided in the optical device 100 (hereinafter referred to as light source oscillation time). The timer unit 34B is a known clock function unit that measures the current time.

The distance calculation unit 34 stores, in the memory unit 34A, the time when the light intensity indicated by the voltage signal reaches the threshold value E1 from the waveform indicated by the voltage signal received from the received light signal processing unit 32. Then, the distance calculating unit 34 calculates the light emitting unit 10 (that is, the optical device 100) from the difference time between the time when the threshold value E1 is reached and the light source oscillation time and the light propagation speed (≈3 × 10 ⁸ m / s). And the distance between the object P and the measurement object P are calculated. That is, the distance calculation unit 34 calculates the distance between the optical device 100 and the measurement object P by multiplying the difference time between the time when the threshold value E1 is reached and the light source oscillation time by the light propagation speed.

  The distance calculation unit 34 may use a phase difference instead of the difference time between the time when the threshold E1 is reached and the light source oscillation time. Specifically, the light emitted from the light source may be used as a sinusoidal intensity modulation signal, and the difference time may be obtained from the difference between the phase of the optical signal immediately after emission from the light source and the phase of the reflected light from the object. . The signal immediately after emission from the light source can be obtained, for example, by receiving reflected light from the cover glass of the device housing with a light receiver. These phase differences may be obtained by, for example, measuring the above two types of signals by a generally known method such as heterodyne detection.

  Then, the distance calculation unit 34 outputs the calculated distance to the display unit 40. By repeating the above process at each scanning spot, three-dimensional distance data can be obtained in each scanning region of the scanning region 111 of the light L1 and the scanning region 112 of the light L2.

The object identification unit 36 is a functional unit that identifies the measurement target P. The object identification unit 36 converts the peak intensity P _{L1 of} the waveform 44 indicated by the voltage signal corresponding to the light intensity of the wavelength component of the light L1 extracted by the received light signal processing unit 32 and the light intensity of the wavelength component of the light L2. An object having a reflection spectrum stored in advance and showing a spectral reflectance corresponding to the peak intensity P _L2 of the waveform 46 indicated by the corresponding voltage signal is identified as the measurement object P.

  Specifically, the object identification unit 36 includes a reflectance index calculation unit 36A that calculates a reflectance index of the measurement object P, an object identification unit 36B, and a storage unit 36C.

The storage unit 36C stores in advance the light intensity P _L1ini of the light L1 emitted from the optical unit 11. In addition, the storage unit 36C stores in advance the light intensity P _L2ini of the light L2 emitted from the optical unit 12. The light intensity P _L1ini and the light intensity P _L2ini may be measured and stored in advance.

  In addition, the storage unit 36C stores in advance each type of reflection spectrum (hereinafter referred to as a reference reflection spectrum) when the measurement target P to be identified is classified into a plurality of types for each characteristic.

  For example, the case where the optical apparatus 100 is applied as a sensor mounted on a vehicle is assumed. In this case, the reference reflection spectrum indicating the spectral reflectance when the person is irradiated with light in a wavelength region including the wavelength of the light L1 (first wavelength) and the wavelength of the light L2 (second wavelength). And a reference reflection spectrum indicating the spectral reflectance when the road surface is irradiated with light in a wavelength region including the wavelength of the light L1 and the wavelength of the light L2.

  FIG. 8 is a schematic diagram illustrating an example of a reference reflection spectrum. The diagram 48 is a diagram showing a reference reflection spectrum when a person (human skin) is irradiated with light in a wavelength region including the wavelengths of the light L1 and the light L2. Further, the diagram 52 is a diagram showing a reference reflection spectrum when the lubrication road surface is irradiated with light in a wavelength region including the wavelengths of the light L1 and the light L2.

  The reference reflection spectrum stored in advance in the storage unit 36C is not limited to the above two types, and is appropriately adjusted according to the use of the optical device 100. That is, the number of reference reflection spectra stored in advance in the storage unit 36C is not limited to the reference reflection spectra of two types of objects, and may be the reference reflection spectra of each of three or more types of objects.

The reflectance index calculation unit 36A is configured to extract the peak intensity P _{L1 of} the waveform 44 indicated by the voltage signal corresponding to the light intensity of the wavelength component of the light L1 extracted by the received light signal processing unit 32, and the light of the wavelength component of the light L2. The peak intensity P _L2 of the waveform 46 indicated by the voltage signal corresponding to the intensity is received.

  Then, the reflectance index calculation unit 36A calculates a reference reflectance index of the reference reflection spectrum. The reference reflectance index is a value that serves as an index for specifying the reference reflection spectrum. In the present embodiment, the reflectance index calculation unit 36A is based on the light intensity at the wavelength of the light L1 and the light intensity at the wavelength of the light L2 in the reference reflection spectrum, and is stored in the storage unit 36C. A reference reflectance index for each of the reflection spectra is calculated. The calculation of the reference reflectance index may be executed in advance and stored in advance in the storage unit 36C in association with the corresponding reference reflection spectrum.

  The reflectance index calculation unit 36A calculates the reference reflectance index as follows.

  For example, the reflectance index calculation unit 36A, from the reference reflection spectrum, the light intensity corresponding to the wavelength (eg, 1.3 μm) of the light L1 emitted from the light source 11A and the wavelength (eg, the light L2 emitted from the light source 12A). The light intensity corresponding to 1.5 μm) is extracted. The reflectance index calculation unit 36A then subtracts the subtracted value obtained by subtracting the light intensity of the light on the long wavelength side (here, light L2) from the light intensity of the light on the short wavelength side (here, light L1). A division value obtained by dividing the light intensity of the light (here, light L1) and the light intensity of the light on the long wavelength side (here, light L2) by the added value is calculated as a reference reflectance index.

  Specifically, as the reference reflection spectrum, the reference reflection spectrum shown by the diagram 48 (person) shown in FIG. 8 and the reference reflection spectrum shown by the diagram 52 (lubricated road surface) are stored in the storage unit 36C. Suppose.

  In this case, the reflectance index calculation unit 36A calculates a reference reflectance index indicating the lubricating road surface from the reference reflection spectrum of the lubricating road surface using the following formula (1). Further, the reflectance index calculation unit 36A calculates a reference reflectance index indicating a person from the reference reflection spectrum of the person using the following equation (2).

In the equation (1), I ₁ represents a reference reflectance index of the lubricated road surface obtained from the reference reflection spectrum shown by the diagram 52 (lubricated road surface) shown in FIG. Moreover, in Formula (1), R1 _LOW shows the reflectance corresponding to the wavelength (1.3 micrometers) of the light L1 in the reference | standard reflection spectrum of this lubrication road surface. In the formula (1), _{R1 Hi} represents the reference reflectance spectra of該潤smooth road surface, the reflectance corresponding to the wavelength of the light L2 (1.5μm).

In the formula (2), I ₂ represents a reference reflectance index of a person obtained from a reference reflection spectrum indicated by a diagram 48 (person) shown in FIG. Moreover, in Formula (2), R2 _LOW shows the reflectance corresponding to the wavelength (1.3 micrometers) of the light L1 in the reference | standard reflection spectrum of this person. In the formula (2), _{R2 Hi} is definitive Contact to the reference reflectance spectra of the person thereof shows the wavelength of the light L2 reflectance corresponding to (1.5 [mu] m)).

  Then, the reflectance index calculation unit 36A calculates a reference reflectance index corresponding to each of the reference reflectance spectra stored in the storage unit 36C (in this embodiment, a reference reflectance index indicating a lubricating road surface, and a person. (Reference reflectance index shown) is calculated in advance and stored in the storage unit 36C in advance.

Further, the reflectance index calculation unit 36A receives the peak intensity P _{L1 of} the waveform 44 indicated by the voltage signal corresponding to the light intensity of the wavelength component of the light _L1 and the voltage signal corresponding to the light intensity of the wavelength component of the light L2. The peak intensity P _L2 of the waveform 46 shown is received from the received light signal processing unit 32. Then, the reflectance index calculation unit 36A calculates the reflectance index of the reflected light L3.

More specifically, first, the reflectance index calculation unit 36A, the light intensity _{P L1ini} light L1 when emitted from the optical unit 11, and the light intensity _{P L2ini} light L2 when emitted from the optical unit 12, a storage unit Read from 36C.

Then, the reflectance index calculation unit 36A emits the peak intensity P _L1 of the waveform 44 indicated by the voltage signal according to the light intensity of the wavelength component of the light L1 received from the received light signal processing unit 32 from the optical unit 11. The division value divided by the light intensity P _L1ini of the light _L1 is calculated as the reflectance R _L1 of the light L1 (see Expression (3)). Further, the reflectance index calculation unit 36A emits from the optical unit 12 the peak intensity P _L2 of the waveform 46 indicated by the voltage signal according to the light intensity of the wavelength component of the light L2 received from the received light signal processing unit 32. The division value divided by the light intensity P _L2ini of the light L2 at that time is calculated as the reflectance R _L2 of the light L2 (see Expression (4)).

Then, the reflectivity index calculation unit 36A is a subtraction value obtained by subtracting the reflectance _{R L2} of the light L2 from the reflectance _{R L1} of the light L1, the sum of the reflectance _{R L2} of the reflection factor _{R L1} and the light L2 of the light L1 The division value divided by is calculated as the reflectance index I _md of the reflected light L3 (see formula (5)).

  In the above formulas (1), (2), and (5), the reflectance is used to calculate the reference reflectance index and the reflectance index, but the light intensity may be used instead of the reflectance. .

The object identification unit 36B identifies the measurement object P. Specifically, the object identification unit 36B includes the reflectance index I _md of the reflected light L3 calculated by the reflectance index calculation unit 36A, and the reference reflectance index stored in the storage unit 36C (in this embodiment, the reference index The reflectance indices I _{1 to} I ₂ ) are compared. Then, the reference reflectance index indicating a value within ± 10% of the reflectance index I _md of the reflected light L3 calculated by the reflectance index calculation section 36A among the reference reflectance indices stored in the storage section 36C is specified. The object to be measured is identified as the object of the measurement object P.

The object identification unit 36B indicates a value within ± 10% of the reflectance index I _md of the reflected light L3 calculated by the reflectance index calculation unit 36A among the reference reflectance indices stored in the storage unit 36C. When there are a plurality of reference reflectance indices, the object specified by the reference reflectance index closest to the reflectance index I _md is identified as the object of the measurement object P.

  Then, the object identification unit 36B outputs information indicating the identified object to the display unit 40. By repeating the above process for each scanning spot, it is calculated whether or not the same object as the object specified by the plurality of types of reference reflectance indices stored in the storage unit 36C exists in the overlapping region 113. Can do.

  Next, a procedure of distance calculation processing executed by the calculation unit 30 of the optical device 100 will be described. FIG. 9 is a flowchart illustrating a procedure of distance calculation processing executed by the calculation unit 30.

  First, the light reception signal processing unit 32 of the calculation unit 30 receives a voltage signal corresponding to the light intensity of the reflected light L3 from the light receiver 22C (step S200).

  Next, the distance calculation unit 34 calculates the distance between the optical device 100 and the measurement object P based on the voltage signal received from the received light signal processing unit 32 (step S202).

  Next, the distance calculation unit 34 outputs information indicating the calculated distance to the display unit 40 (step S204), and this routine is terminated.

  Next, the procedure of the object identification process performed by the calculation unit 30 of the optical device 100 will be described. FIG. 10 is a flowchart illustrating a procedure of object identification processing executed by the calculation unit 30.

  First, the light reception signal processing unit 32 of the calculation unit 30 receives a voltage signal corresponding to the light intensity of the reflected light L3 from the light receiver 22C (step S300).

Next, the waveform indicated by the voltage signal according to the light intensity of the wavelength component of the light L1 from the waveform indicated by the voltage signal according to the light intensity of the reflected light L3 received from the light receiver 22C. The peak intensity P _{L1 of} 44 and the peak intensity P L2 of the waveform 46 indicated by the voltage signal corresponding to the light intensity of the wavelength component of the light _L2 are extracted (step S302).

  Next, the reflectance index calculation unit 36A of the object identification unit 36 calculates the reflectance index of the reflected light L3 (step S304). Then, the object identification unit 36B performs an object identification process for identifying the measurement target P based on the calculated reflectance index and the reference reflectance index stored in the storage unit 36C (step S306). .

  Then, the object identification unit 36B outputs information indicating the identified object to the display unit 40 (step S308), and the routine is terminated.

  As described above, the optical device 100 according to the present embodiment includes the light emitting unit 10 including the light sources (the light source 12A and the light source 11A) that output light having different wavelengths, and the light emitted from the light emitting unit 10 ( The light receiving part 20 which receives the reflected light L3 of the light L1 and the light L2), and the calculation part 30 are provided. In the calculation unit 30, the light intensity of the wavelength component of the light L1 included in the reflected light L3, the light intensity of the wavelength component of the light L2 included in the reflected light L3, and the reflection spectra of each of a plurality of types of objects stored in advance. The measurement object P is identified based on the above.

  Further, in the optical device 100, the light emitting unit 10 (that is, the optical device 100) and the measurement target are calculated from the phase difference or time difference between the light (L1 and L2) emitted from the light emitting unit 10 and the reflected light L3 and the light propagation speed. The distance to the object P is calculated.

  For this reason, in the optical device 100 of the present embodiment, distance measurement and object identification can be realized with a simple configuration without impairing high-speed response.

  Specifically, the object identification information can be easily obtained together with the distance information by adding a few components and a simple analysis mechanism to the optical device for measuring the distance.

(Modification)
In the above embodiment, the light emitting unit 10 irradiates the measurement object P with the light L1 emitted from the optical unit 11 and the light L2 emitted from the optical unit 12 being deflected by the light deflecting device 13. Explained. The light L1 and the light L2 may be combined by the combining member, and then deflected by the light deflecting device 13 to irradiate the measurement object P.

  FIG. 11 is a schematic diagram illustrating an example of the configuration of the light emitting unit 10 </ b> A including the multiplexing member.

  The light emitting unit 10 </ b> A includes a lighting controller 14, an optical unit 11, an optical unit 12, a light deflecting device 13, and a multiplexing member 15. Since the lighting controller 14, the optical unit 11, the optical unit 12, and the lighting controller 14 are the same as those in the first embodiment, detailed description thereof is omitted. Note that the optical unit 11 in the light emitting unit 10A shown in FIG. 11 is configured not to include the deflection prism 11D.

  The multiplexing member 15 is a multiplexer that multiplexes the light L1 emitted from the optical unit 11 and the light L2 emitted from the optical unit 12. Examples of the multiplexing member 15 include a dichroic mirror. The light L4 obtained by combining the light L1 and the light L2 reaches the measurement object P via the light deflecting device 13. Here, the light L4 deflected by the light deflecting device 13 reaches the measurement object P in a state where no deflection angle difference occurs with respect to the light (light L1, light L2) from each optical unit 11 and optical unit 12. The

  Therefore, by adopting a configuration in which the multiplexing member 15 is provided in the light emitting portion 10A, an optical scanning region by the light L1 (see the optical scanning region 111 in FIG. 4) and an optical scanning region by the light L2 (in FIG. 4). , The overlapping region 113 with the optical scanning region 112) can be enlarged as compared with the case where the multiplexing member 15 is not provided.

  For this reason, the polarization of the light L1 and the light L2 irradiated to the measuring object P can be made uniform, and the fluctuation | variation of the light intensity of the reflected light L3 by the influence of polarization can be suppressed. As a result, errors in the light reception signal analysis process in the light reception signal processing unit 32 and the object identification unit 36 can be reduced, and object identification can be performed with higher accuracy.

  Further, the multiplexing member 15 may be a hologram element instead of the dichroic mirror. FIG. 12 is a schematic diagram illustrating an example of a light emitting unit using the hologram element 16 as the combining member 15.

  As illustrated in FIG. 12, the light emitting unit 10 </ b> B includes a lighting controller 14, an optical unit 11, an optical unit 12, an optical unit 17, a light deflecting device 13, and a hologram element 16. The lighting controller 14, the optical unit 11, the optical unit 12, and the light deflecting device 13 are the same as those in the first embodiment. In addition, the optical unit 11 in the light emitting unit 10A illustrated in FIG. 12 is configured not to include the deflection prism 11D.

  The optical unit 17 includes a light source 17A, a collimating lens 17B, and an aperture 17C. Specifically, the optical unit 17 includes a collimating lens 17B and an aperture 17C in order from the light source 17A side.

  The light source 17A is a light source that emits light of a predetermined specific wavelength. The light source 17A emits light having a wavelength different from that of other light sources (in the present embodiment, the light source 11A and the light source 12A) provided in the light emitting unit 10B. Examples of the light source 17A include a semiconductor laser that emits laser light and an LED element.

  The collimating lens 17B collimates (in parallel) the laser light emitted from the light source 17A and converts it into a parallel light beam. The aperture 17C functions as an aperture that adjusts the amount of light passing therethrough. Specifically, the aperture 17 </ b> C has a spot diameter so that the spot diameter of the light emitted from the optical unit 17 to the measurement object P matches the spot diameter of the light emitted from the optical unit 12 and the optical unit 11. Adjust.

  The hologram element 16 as the multiplexing member 15 combines the light L1, the light L2, and the light L5 emitted from the optical unit 11, the optical unit 12, and the optical unit 17. The combined light L6 is deflected by the light deflecting device 13 and reaches the measurement object P.

  Thus, when the hologram element 16 is used as the multiplexing member 15, light emitted from three or more types of light sources can be multiplexed. Moreover, the polarization of the light L1, the light L2, and the light L5 irradiated to the measurement object P can be made uniform, and the fluctuation of the light intensity of the reflected light L3 due to the influence of the polarization can be suppressed.

For this reason, by adopting a configuration in which the hologram element 16 is provided in the light emitting unit 10B, an overlapping region of the light scanning region by the light L1, the light scanning region by the light L2, and the light scanning region by the light L3 is converted into a hologram. It can be enlarged as compared with the case where the element 16 is not provided. A wider measurement area and object identification area can be realized.

  In addition to the configuration of the light emitting unit 10 shown in FIG. 2, it is preferable to further provide a polarizing element 18 on the light incident side of the light deflecting device 13. FIG. 13 is a schematic diagram illustrating an example of a configuration of a light emitting unit including the polarizing element 18.

  As illustrated in FIG. 13, the light emitting unit 10 </ b> C may be configured to include a lighting controller 14, an optical unit 11, an optical unit 12, a light deflecting device 13, and a polarizing element 18. The light deflecting device 13 may be provided on the light emitting side of the optical unit 11 and the optical unit 12 and on the light incident side of the light deflecting device 13.

  The polarizing element 18 may be an element having a function of aligning the polarization of light incident on the polarizing element 18. For the polarizing element 18, for example, a wire grid polarizer having a low incident angle dependency with respect to optical loss is used. By using a wire grid polarizer as the polarizing element 18, it is possible to align the polarization with one element for two light beams (light beams L 1 and L 2) having different incident angles to the polarizing device 18.

  Here, the light intensity of the reflected light L3 (see FIG. 5) received by the light receiving unit 20 varies under the influence of the polarization of the light applied to the measurement object P. This is because, in particular, when the light is incident on an object such as the measurement object P, the object surface of the measurement object P is often not perpendicular to the incident light. Therefore, as shown in FIG. 13, the light emitting unit 10 </ b> C is provided with a polarizing element 18. In this way, the polarization element 18 is provided, and the light intensity of the reflected light L2 received by the light receiving unit 20 is changed by aligning the polarizations of the light L1 and the light L2 emitted from the optical units 11 and 12. Can be suppressed.

  Note that “polarized light is aligned” means that the difference between the polarization degree of the light L1 (that is, the ratio of the polarized component to the total intensity component) and the polarization degree of the light L2 is within a range of ± 10%. Indicates that there is.

  13 shows the light emitting unit 10C having a configuration in which the light emitting unit 10 having the configuration shown in FIG. 5 is further provided with the polarizing element 13, the light emitting unit 10A having the configuration shown in FIG. 11 and FIG. It is good also as a structure further equipped with the polarizing element 18 in the light-projection part 10B of the structure shown. In this case, the polarizing element 18 may be provided on the light incident side of the light deflecting device 13 and on the light emitting side of the multiplexing member 15 (or hologram element 16).

DESCRIPTION OF SYMBOLS 100 Optical apparatus 10, 10A, 10B, 10C Light emission part 11A, 12A Light source 15 Combined member 16 Hologram element 20 Light receiving part 30 Calculation part 32 Light reception signal processing part 34 Distance calculation part 36, 36B Object identification part

JP 2002-40139 A JP 2007-13951 A JP 2006-275955 A JP 2010-256303 A JP 2007-278950 A JP 2002-345760 A

Claims (7)

A light emitting means having a first light source that emits light of a first wavelength and a second light source that emits light of a second wavelength different from the first wavelength;
A light receiving means for receiving the reflected light from the measurement object of the emitted light including the light of the first wavelength and the light of the second wavelength emitted from the light emitting means;
Storage means for storing in advance the reflection spectrum of the object;
Identification means for identifying, as the measurement object, an object having the reflection spectrum indicating the spectral reflectance according to the first light intensity of the first wavelength and the second light intensity of the second wavelength, which is included in the reflected light. When,
Distance calculating means for calculating the distance between the optical device and the measurement object based on the difference between the light emission time of the emitted light and the light reception time of the reflected light, and the light propagation speed;
An optical device. A division value obtained by dividing the difference between the first light intensity and the second light intensity by the addition value of the first light intensity and the second light intensity is calculated as a reflectance index indicating the characteristic of the reflected light. And
A divided value obtained by dividing the difference between the third light intensity of the first wavelength and the fourth light intensity of the second wavelength in the reflection spectrum of the object by the added value of the third light intensity and the fourth light intensity. A reflectance index calculating means for calculating as a reference reflectance index indicating the characteristics of the object,
The identifying means identifies the object of the reflection spectrum indicating the spectral reflectance according to the first light intensity and the second light intensity by identifying the object of the reference reflectance index according to the reflectance index. The optical apparatus according to claim 1, wherein the optical apparatus is identified as a measurement object.   The optical apparatus according to claim 1, further comprising a deflecting unit that is provided on a light emitting side of the light emitting unit and deflects outgoing light emitted from the light emitting unit.   4. The apparatus according to claim 1, further comprising a multiplexing unit that is provided on a light emitting side of the light emitting unit and multiplexes the light having the first wavelength and the light having the second wavelength. The optical device described.   5. The device according to claim 1, further comprising a polarizing element that is provided on a light emitting side of the light emitting unit and polarizes the light having the first wavelength and the light having the second wavelength. Optical device. The first light source emits light having the first wavelength of 1000 nm to 1350 nm,
The optical device according to claim 1, wherein the second light source emits light having the second wavelength of 1400 nm to 1600 nm. The first light source emits light having the first wavelength of 780 nm to 900 nm,
The optical device according to claim 1, wherein the second light source emits light having the second wavelength of 940 nm to 990 nm.

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