JP4549206B2 - Position detection device - Google Patents

Description

  The present invention relates to a position detection device, and more particularly to a position detection device that detects a position of an object in a three-dimensional space.

  As a conventional position detection device, for example, there is one using a laser beam. A position detection device using laser light is provided with a laser light source, a mirror, a galvanometer scanner (mechanical drive unit) that reflects the emitted laser light from the laser light source and deflects the reflected laser light, and the emitted laser light and the reflected light. A beam splitter for selecting laser light, a photodetector for detecting reflected laser light, and a distance measuring device for measuring the position of an object.

In such a position detection device, the reflection surface of the mirror is controlled by a galvanometer scanner which is a mechanical drive unit, and the reflected direction of the reflected laser light when receiving retroreflection from the object, and the reflection required by the distance measuring device. Based on the distance from the laser beam to the object, the position of the object in the three-dimensional space is detected (see, for example, Patent Document 1).
JP 2001-147269 A

  However, in the conventional position detection device, the mirror is moved by a mechanically operated galvanometer scanner to scan the laser beam. There was a problem that the accuracy was lowered.

  Further, since the galvanometer scanner (mechanical drive unit) is used, there is a problem that the position detection device cannot be reduced in size. Furthermore, since a laser beam is used, it is necessary to provide a mechanism for safety measures, thereby causing a problem that the position detection device cannot be reduced in size.

  Further, since the position of the object is measured by scanning the laser beam, the measurement time interval cannot be made shorter than the scan time. For this reason, there has been a problem that the response of reflected laser light from the moving object is lowered, and the accuracy of the position of the detected object in the three-dimensional space is lowered.

  Accordingly, the present invention has been made in view of the above points, and an object of the present invention is to provide a position detection device that can obtain the position of an object with high accuracy and can be miniaturized.

According to one aspect of the present invention, in a position detection device that detects the position of an object, a light source that irradiates an optical signal, and a reflection unit that is attached to the object and includes a reflection surface that reflects the optical signal First separating means for separating the optical signal and the optical signal reflected by the reflecting means, a first light receiving element for receiving the reflected optical signal, and the optical signal for the first light receiving element And a second separation means for passing a part of the optical signal toward the second light receiving element and a light receiving surface area smaller than the first light receiving element, and a high response speed, Reflecting on the light receiving surface of the first light receiving element based on the second light receiving element for receiving a part of the optical signal separated by the second separating means and the output signal of the first light receiving element. Reflection position calculating means for determining the position of the optical signal A propagation distance calculation means for obtaining a propagation distance from the light source to the second light receiving element, the position of the optical signal reflected on the light receiving surface of the first light-receiving element obtained in the reflection position calculating means, the propagation An object position calculating means for determining the position of the object based on the propagation distance determined by the distance calculating means; and a control unit, wherein the reflecting means covers the reflecting surface of the reflecting means. A position detecting unit, wherein the control unit controls the opening / closing unit to reflect the optical signal after controlling the opening / closing unit to block the optical signal. An apparatus is provided.

  According to the present invention, by providing the first separation unit that separates the optical signal and the optical signal reflected by the reflecting unit, it is possible to irradiate the optical signal in a predetermined range and deflect the optical signal. A mechanical drive (galvanometer scanner) is not required. Thereby, mechanical vibration is eliminated, the position of the object can be obtained with high accuracy, and the position detection device can be miniaturized. Further, by providing the reflection position calculation means, the propagation distance calculation means, and the object position calculation means, the position of the reflected optical signal on the light receiving surface of the first light receiving element and the first light receiving element from the light source The position of the object can be obtained by the object position calculating means based on the propagation distance up to.

  The present invention can obtain a position of an object with high accuracy and can realize a position detection device that can be miniaturized.

  Next, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
With reference to FIG. 1, the position detection apparatus 10 of 1st Embodiment is demonstrated. FIG. 1 is a schematic configuration diagram of a position detection apparatus according to the first embodiment. In FIG. 1, A is an optical signal (hereinafter referred to as “optical signal A”) emitted from the light source 15 separated downward in the figure by the first separating means 21, and B is irradiated with the optical signal A. Area (hereinafter referred to as “irradiation area B”), C is the optical signal A reflected by the reflecting means (hereinafter referred to as “optical signal C”), and E is the mirror image position of the light source 15 (hereinafter “mirror image”). F represents the spot image of the optical signal C on the light receiving surface 26A of the first light receiving element 26 (hereinafter referred to as “spot image F”). Further, in the figure, the X and X directions indicate directions parallel to the light receiving surface 26A of the first light receiving element 26, and the Z and Z directions indicate directions perpendicular to the light receiving surface 26A of the first light receiving element 26, respectively. Yes.

  The position detection device 10 includes a device main body 11 and a calculation means 12. The position detection device 10 is for detecting the position of the object 24 in the three-dimensional space. The position detection device 10 is connected to the information terminal 13, and data related to the position of the object 24 in the three-dimensional space is displayed on the information terminal 13. The information terminal 13 is, for example, a personal computer.

  The apparatus main body 11 includes an optical signal generation unit 14, a condenser lens 20, a first separation unit 21, a reflection unit 22 including a recursive optical system, and a first light receiving element 26.

  The optical signal generator 14 includes a light source 15, a light source driver 16, an optical signal modulator 18, and an optical signal controller 19. The light source 15 is for generating an optical signal. The light source 15 is disposed at a position where the surface 21A of the first separating means 21 can be irradiated with an optical signal. As the light source 15, for example, an infrared LED capable of emitting infrared light may be used.

  As described above, by using the infrared LED as the light source 15, the safety measure mechanism required in the conventional position detecting device using the laser beam becomes unnecessary, and the position detecting device 10 can be downsized. .

  The light source driving unit 16 is for driving the light source 15. The optical signal modulation unit 18 modulates the output signal of the light source driving unit 16 by the output signal controlled by the optical signal control unit 19. Specifically, the optical signal modulating unit 18 modulates any one of the intensity, phase, and frequency of the optical signal emitted from the light source 15. In the present embodiment, the following description is given by taking as an example the case where the intensity of an optical signal is modulated. For example, an oscillator can be used as the optical signal modulator 18. The optical signal control means 19 is for controlling the output signal of the optical signal modulation means 18.

  In this way, by providing the optical signal modulation means 18 that modulates any one of the intensity, phase, and frequency of the optical signal emitted from the light source 15, the modulation signal of the optical signal modulation means 18 and the reflected return light are detected. The propagation time of the optical signal can be calculated by comparison with the demodulated signal, and the distance to the object 24 can be calculated.

  The condenser lens 20 is provided between the light source 15 and the first separation means 21. The condenser lens 20 is for reducing the spot image F of the optical signal C formed on the light receiving surface 26A of the first light receiving element 26 described later.

  The first separating means 21 is arranged such that the light receiving surface 26A of the first light receiving element 26 and the surface 21A of the first separating means 21 form an angle of 45 degrees. The first separation means 21 does not move and its position is fixed. The first separation means 21 is for irradiating the optical signal A downward in FIG. As the first separating means 21, for example, an anti-transmissive mirror having a reflectance set to about 50% can be used.

  Thus, the mechanical drive for irradiating the target 24 with the optical signal is provided by providing the first separating unit 21 and forming the irradiation region B irradiated with the optical signal A by the first separating unit 21. A part (for example, a galvanometer scanner) is unnecessary, the problem of mechanical vibration is solved, the position of the object 24 in the three-dimensional space can be determined with high accuracy, and the position detection device 10 can be downsized. Can be planned.

  FIG. 2 is a sectional view of the reflecting means, and FIG. 3 is an enlarged perspective view of the reflecting sheet. In FIG. 2, the same components as those in FIG.

  As shown in FIG. 2, the reflection means 22 includes a sheet-like base material 23 and a reflection sheet 25, and is attached to an object 24 whose position in a three-dimensional space is desired to be detected. The reflection sheet 25 is provided on the sheet-like base material 23. As shown in FIG. 3, the reflection sheet 25 includes a plurality of triangular pyramid reflectors 28. The reflector 28 has a reflecting surface 28A for reflecting the optical signal A. The plurality of reflectors 28 are arranged such that the reflecting surfaces 28A form an angle of 90 degrees with each other. The optical signal A reflected by the reflecting surface 28A becomes an optical signal C, and the optical signal C substantially reverses the optical path of the optical signal A, and is substantially the same as the light source 15 at the mirror image position E of the light source 15 by the first separating means 21. Form spot images of equal size. Examples of the object 24 include humans and portable devices (for example, PDAs).

  FIG. 4 is a perspective view of the first light receiving element. In FIG. 4, G1 is the center of gravity of the light receiving surface 26A of the first light receiving element 26 (hereinafter referred to as “center of gravity G1”), and G2 is the center of gravity of the spot image F of the optical signal C (hereinafter “center of gravity”). V is a direction vector (hereinafter referred to as “direction vector V”) of the optical signal C incident on the light receiving surface 26A of the first light receiving element 26, and the Y and Y directions are the X and X directions. Each orthogonal direction is shown. In FIG. 4, the same components as those in FIG.

  As shown in FIG. 4, the first light receiving element 26 includes a light receiving surface 26A that receives the optical signal C, and four electrodes 27 provided on four sides of the light receiving surface 26A. The four electrodes 27 are connected to any one of amplifiers 29A to 29D described later. When the light receiving surface 26A receives the optical signal C, the four electrodes 27 output currents corresponding to the resistance from the spot image F of the optical signal C on the light receiving surface 26A to each electrode 27 to the amplifiers 29A to 29D.

  The first light receiving element 26 having the above-described configuration is provided on the optical path of the optical signal C that is a distance d away from the mirror image position E of the light source 15 in the traveling direction of the optical signal C (see FIG. 1). The distance d is an offset amount. As the first light receiving element 26, for example, a PIN photodiode having a uniform resistance on the light receiving surface 26A can be used.

  Next, the calculation unit 12 will be described with reference to FIG. The calculation unit 12 includes amplifiers 29A to 29D, filters 31A to 31D, output current reception means 33, reflection position calculation means 41, propagation distance calculation means 45, object position calculation means 50, and correction means 51. Have

  The amplifiers 29A to 29D are connected to the four electrodes 27 of the first light receiving element 26 and the filters 31A to 31D. When the light receiving surface 26A of the first light receiving element 26 receives the optical signal C, the amplifiers 29A to 29D amplify the output current (output signal) from the electrode 27 and transmit it to the filters 31A to 31D. For example, amplifiers can be used as the amplifiers 29A to 29D.

  The filters 31A to 31D are for removing noise from the output current amplified by the amplifiers 29A to 29D. As the filters 31A to 31D, for example, bandpass filters can be used.

  The output current receiving unit 33 includes a detection unit 34, a determination unit 35, a synchronization unit 36, and a demodulation unit 37. When the detection unit 34 receives the sum of the output currents that have passed through the filters 31 </ b> A to 31 </ b> D, the output current reception unit 33 generates a reception signal for demodulating the modulation signal of the reflected light, and the target position calculation unit from the demodulation unit 37. 50, a synchronization signal such as a clock signal (specifically, used for determination of the spot position and calculation of information of the direction vector V in synchronization with this signal) is transmitted.

The reflection position calculation means 41 includes a reflection position calculation unit 42 and an A / D conversion unit 43. The reflection position calculation unit 42 is connected to the filters 31 </ b> A to 31 </ b> D and the A / D conversion unit 43. Based on the output current that has passed through the filters 31A to 31D, the reflection position calculation unit 42 uses the center of gravity position G1 of the light receiving surface 26A of the first light receiving element 26 as the origin (that is, the coordinates of the center of gravity position G1 are (X, Y, Z ) = (0, 0, 0)), the gravity center position G2 of the spot image F of the optical signal C (hereinafter, the coordinates of the gravity center position G2 are (X, Y, Z) = (X ₁ , Y ₁ , 0). )).

  When the gravity center position G1 exists on the optical axis, the direction vector V of the optical signal C incident on the light receiving surface 26A of the first light receiving element 26 can be calculated by the following equation (1).

V = (− X ₁ , −Y ₁ , 0) (1)
The A / D conversion unit 43 is connected to the reflection position calculation unit 42 and the object position calculation unit 50, and performs A / D conversion on data related to the gravity center position G2 of the optical signal C obtained by the reflection position calculation unit 42. Then, it transmits the object position calculation means 50.

  The propagation distance calculation unit 45 includes a synchronous detection unit 46, an A / D conversion unit 47, and a propagation distance calculation unit 48. The synchronous detector 46 is connected to the optical signal modulator 18. The synchronous detector 46 modulates and drives the intensity of the light source 15 via the light source driver 16 by the output signal of the optical signal modulator 18 that generates a sine wave at a predetermined frequency, and the optical signal A is emitted. The sum of the output currents of the electrodes 27 that have passed through the filters 31A to 31D is synchronously detected by the signal (intensity modulation signal) of the optical signal modulation means 18 to obtain phase information. This phase information is transmitted to the A / D converter 47.

The A / D conversion unit 47 is connected to the synchronous detection unit 46 and the propagation distance calculation unit 48. The A / D converter 47 performs A / D conversion on the phase information obtained by the synchronous detector 46 and transmits it to the propagation distance calculator 48. The propagation distance calculator 48 detects the propagation time based on the A / D converted phase information, and the propagation distance from the light source 15 to the light receiving surface 26A of the light receiving element 26 (hereinafter referred to as “propagation distance r ₁ ”). ) And data related to the propagation distance r ₁ are transmitted to the object position calculation means 50.

The object position calculation unit 50 performs the overall control of the calculation unit 12, and the gravity center position G 2 of the spot image F of the optical signal C obtained by the reflection position calculation unit 41 and the propagation distance r obtained by the propagation distance calculation unit 45. ₁ , the position in the three-dimensional space of the object 24 to which the reflecting means 22 is attached is obtained.

  Here, with reference to FIG.1 and FIG.5, the method of calculating | requiring the position in the three-dimensional space of the target object 24 (when the gravity center position G1 is made into the origin) is demonstrated. FIG. 5 is a diagram for explaining how to obtain the position of the object in the three-dimensional space. In FIG. 5, L is a distance from the center of gravity G1 to the reflecting means 22 (hereinafter referred to as “distance L”), tV (t is an arbitrary real number) has a direction vector V, and passes through the center of gravity G1. Each straight line (hereinafter referred to as “straight line tV”) is shown.

When the coordinate system in FIG. 4 described above is a coordinate system in a three-dimensional space in which the object 24 exists, the propagation distance r ₁ is from twice the distance L from the gravity center position G 1 to the reflecting means 22 to a distance d ( It is equal to the value obtained by subtracting the offset amount, and the following equation (2) is established.

r ₁ = 2L−d (2)
Thereby, the distance L from the gravity center position G1 to the reflection means 22 can be calculated | required by following (3) Formula.

L = (r ₁ + d) / 2 (3)
Therefore, as shown in FIG. 5, the position of the object 24 in the three-dimensional space can be obtained as the intersection H of the hemisphere whose radius centered on the gravity center position G1 is equal to the distance L and the straight line tV. it can.

  In addition, for example, when detecting the position of the object 24 existing in the room in the three-dimensional space, the installation terminal is connected to the information terminal 13 connected to the position detection device 10 (for example, information on the indoor floor plan, Information on the installation position of the first light receiving element 26, the first separation means 21 and the like with respect to the floor plan) is stored, and the position of the object 24 in the three-dimensional space and the installation position information are collated, thereby The position of the object 24 can be specified.

  The correction unit 51 includes a storage unit 52 and a correction unit 53. The storage unit 52 is connected to the correction unit 53 and the object position calculation means 50. The correction unit 51 stores reference data obtained in advance, correction data obtained from the correction unit 53, and the like. The reference data is data (coordinate data) related to a known position.

  The correction unit 53 is connected to the storage unit 52 and the object position calculation means 50. The correction unit 53 obtains correction data based on the difference between the reference data stored in the storage unit 52 and the data when the object 24 is placed at a predetermined position, and stores the correction data in the storage unit 52. Let

  Further, the object position calculation means 50 corrects the position of the object 24 in the three-dimensional space based on the correction data stored in the storage unit 52.

  As described above, the correction unit 51 is provided, and the object position calculation unit 50 corrects the position of the object 24 in the three-dimensional space based on the correction data obtained by the correction unit 51, so that the tertiary of the object 24 is obtained. The position in the original space can be obtained with high accuracy.

  As described above, according to the position detection device 10 of the present embodiment, the optical signal A is applied to the object 24 by forming the irradiation region B to which the optical signal A is irradiated by the first separation unit 21. A mechanical drive unit (for example, a galvanometer scanner) for irradiating the object 24 becomes unnecessary, the problem of mechanical vibration is solved, and the position of the object 24 in the three-dimensional space can be obtained with high accuracy. The position detection device 10 can be downsized.

  The position detection device 10 may be provided with a plate-like member having an opening (pinhole). In this case, the plate-like member may be arranged so that the mirror image position E of the light source 15 is accommodated in the opening. By providing such a plate-like member, the blur of the spot image F of the optical signal C formed on the light receiving surface 26A of the light receiving element 26 is reduced, and the gravity center position G2 of the spot image F is determined by the reflection position calculation unit 42. It can be obtained with high accuracy.

  Further, a light shielding means (for example, a filter) that shields light other than the wavelength of the light source 15 may be provided in the optical path of the optical signal A and / or the optical path of the optical signal C. By providing such a light shielding means, unnecessary light such as room illumination or outside light can be removed, and the S / N ratio of the output current of the electrode 27 can be improved.

  Further, as the propagation distance calculation means 45, in addition to the modulation method described above, a method for measuring the propagation time of pulsed light may be used.

(Second Embodiment)
With reference to FIG. 6, the position detection apparatus 60 of 2nd Embodiment is demonstrated. FIG. 6 is a schematic configuration diagram of a position detection apparatus according to the second embodiment. In FIG. 6, M is a distance from the mirror image position E of the light source 15 to the condenser lens 67 (hereinafter referred to as “distance M”), and N is a light receiving surface 66A of the second light receiving element 66 from the condenser lens 67. (Hereinafter referred to as “distance N”), D is an optical signal C (hereinafter referred to as “optical signal D”) separated toward the second light receiving element 66 by the second separation means 65. Respectively. In FIG. 6, the same components as those of the position detection device 10 shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The position detection device 60 includes a device main body 61 and a calculation means 62 and is connected to the information terminal 13. The apparatus main body 61 is configured such that, in addition to the configuration of the apparatus main body 11 described in the first embodiment, a second separating means 65, a second light receiving element 66, and a condensing lens 67 are further provided. Yes.

  The second separating means 65 is for passing the optical signal C to the first light receiving element 26 side and for directing a part of the optical signal C to the second light receiving element 66. The second separating means 65 is disposed at the mirror image position E of the light source 15 so that the surface 65A of the second separating means 65 and the light receiving surface 66A of the second light receiving element 66 form an angle of 45 degrees. . As the second separating means 65, for example, a half mirror can be used.

  The second light receiving element 66 is a light receiving element having a light receiving surface area smaller than that of the first light receiving element 26 and having a fast response speed, and receives the optical signal D separated by the second separating means 65. As the second light receiving element 66, for example, a PIN photodiode used for normal optical communication can be used.

The second light receiving element 66 is connected to the synchronous detection unit 46 and the detection unit 34 via the amplifier 71 and the filter 72. That is, in the position detection device 60 of the present embodiment, the propagation distance calculation means 33 is based on the output current (output signal) from the second light receiving element 66 and the propagation distance from the light source 15 to the second light receiving element 66. r ₂ is obtained.

Here, the reason why the second light receiving element 66 is provided will be described. Generally, the response speed of the light receiving element decreases as the area of the light receiving surface increases. For example, since it is desirable to apply a modulation signal of several MHz or more when detecting a distance range of several meters, the center of gravity position G2 of the spot image F of the optical signal C is determined by the output signal from the first light receiving element 26. When the propagation distance r ₁ from the light source 15 to the first light receiving element 26 is obtained, the area of the light receiving surface of the light receiving element cannot be reduced so much.

Therefore, in addition to the first light receiving element 26, a second light receiving element 66 having a small area of the light receiving surface 66A and a fast response speed is provided, and based on the output current from the second light receiving element 66, the propagation distance calculating means By determining the propagation distance r ₂ from the light source 15 to the second light receiving element 66 by 33, the accuracy of the propagation distance r ₂ can be improved. Thereby, based on the propagation distance r ₂ and the gravity center position G2 of the spot image F of the optical signal C, the object position calculation means 50 can obtain the position of the object 24 in the three-dimensional space with high accuracy.

  The condenser lens 67 is disposed between the second light receiving element 66 and the second separating means 65. The distance M from the mirror image position E of the light source 15 to the condensing lens 67 and the distance N from the condensing lens 67 to the light receiving surface 65A of the second light receiving element 65 are respectively the focal length f of the condensing lens 67. Is set to be twice as large.

  In this way, by arranging the condensing lens 67 so that each of the distances M and N is twice the focal length f, the second can be obtained without depending on the position of the object 24 in the three-dimensional space. The light receiving element 66 can receive the optical signal D.

  The calculating means 62 is provided with an amplifier 71 and a filter 72 in addition to the structure of the calculating means 12 described in the first embodiment, and a structure in which the filter 72 is connected to the synchronous detector 46 and the detector 34. Has been.

  The amplifier 71 is connected to the second light receiving element 66. When the light receiving surface 66A of the second light receiving element 66 receives the optical signal D, the amplifier 71 amplifies the output current from the second light receiving element 66 and transmits it to the filter 72. As the amplifier 71, for example, an amplifier can be used.

  The filter 72 is for removing noise from the output current amplified by the amplifier 71. As the filter 72, for example, a band pass filter can be used.

As described above, according to the position detection device 60 of the present embodiment, the propagation distance calculation means is based on the output current from the second light receiving element 66 having a response speed faster than that of the first light receiving element 26. 33 by obtaining the propagation distance r _2, it is possible to improve the accuracy of the propagation distance r _2. Further, by using the propagation distance r ₂ instead of the propagation distance r ₁ , the position of the object 24 in the three-dimensional space can be obtained with high accuracy.

Note that, when the position of the object 24 in the three-dimensional space is obtained using the propagation distance r ₂ , the same technique as that of the position detection device 10 of the first embodiment can be used.

(Third embodiment)
With reference to FIG. 7, the position detection apparatus 80 of 3rd Embodiment is demonstrated. FIG. 7 is a schematic configuration diagram of a position detection apparatus according to the third embodiment. In FIG. 7, J is an optical signal emitted from the light source 15 and an optical signal emitted from the light source 15 separated downward in the figure by the first separation means 21 (hereinafter referred to as “optical signal J”). K is an optical signal J reflected by the reflecting means 85 (hereinafter referred to as “optical signal K”), and P is a region irradiated with the optical signal K (hereinafter referred to as “irradiation region P”). Show. In FIG. 7, the same components as those of the position detection device 10 shown in FIG.

  The position detection device 80 includes a device main body 81 and a calculation means 12 and is connected to the information terminal 13. The apparatus main body 81 includes a condenser lens 20, a first separating unit 21, a first light receiving element 26, an optical signal generating unit 82, and a reflecting unit 85 including a recursive optical system. That is, the position detection device 80 of the present embodiment has the same configuration as that of the position detection device 10 except that the position detection device 10 described in the first embodiment is different from the configuration of the optical signal generation unit and the reflection unit. Has been.

  FIG. 8 is a block diagram of the optical signal generator of the present embodiment. In FIG. 8, the same components as those of the optical signal generator 14 shown in FIG.

  As shown in FIG. 8, the optical signal generation unit 82 includes a light source 15, a light source driving unit 16, an optical signal modulation unit 18, an optical signal control unit 19, a clock generation unit 83, and a device ID information providing unit 84. And have.

  The clock generation unit 83 generates a clock signal and gives the clock signal to the output signal from the optical signal modulation means 18. The device ID information giving unit 84 is for giving the device ID information as a digital signal to the output signal from the optical signal modulating unit 18. The device ID information is information such as a unique number assigned to the position detection device 80, for example. The light source 15 emits an optical signal J including a clock signal, device ID information, and an output signal from the optical signal modulator 18.

  FIG. 9 is a schematic configuration diagram of the reflecting means. In FIG. 9, the same components as those of the reflecting means 22 shown in FIG.

  As shown in FIG. 9, the reflecting means 85 includes a sheet-like base material 23, a receiving means 88, a plurality of triangular pyramid reflectors 28, an opening / closing means 91, and a control unit 93. The receiving means 88 is provided on the surface 23 </ b> A of the sheet-like base material 23 and is connected to an amplifier 94 of the control unit 93 described later. The receiving means 88 is for receiving an optical signal J including a clock signal, device ID information, and an output signal from the optical signal modulating means 18. The receiving means 88 transmits an output signal to the amplifier 94 when receiving the optical signal J.

  The opening / closing means 91 is disposed so as to cover the plurality of reflectors 28 provided on the surface 23 </ b> A of the sheet-like base material 23. The opening / closing means 91 is connected to a drive circuit 103 of the control unit 93 described later. The opening / closing means 91 is for switching whether or not to irradiate the reflector 28 with the optical signal J. Opening / closing of the opening / closing means 91 is controlled by the control unit 93 in accordance with the optical signal J received by the receiving means 88.

  When the opening / closing means 91 is opened (the state shown in FIG. 8), the optical signal J passes through the opening / closing means 91 and reaches the reflector 28, and the optical signal J is reflected by the reflecting surface 28A of the reflector 28. Reflected as K. When the opening / closing means 91 is closed, the optical signal J is blocked by the surface of the opening / closing means 91, and the optical signal J does not reach the reflector 28, so that the optical signal K is not reflected. The reflecting means 85 has a drive power supply (not shown), and the opening / closing means 91 is driven by this drive power supply.

  As the opening / closing means 91, for example, a liquid crystal modulation element can be used. By using a liquid crystal modulation element as the opening / closing means 91, the opening / closing means 91 can be driven at a low voltage. In this case, a small battery, a photovoltaic device or the like can be used as the driving power source.

  The control unit 93 includes an amplifier 94, a filter 96, a detection unit 98, a clock detection unit 99, a synchronization unit 101, a storage unit 102, and a drive circuit 103. The amplifier 94 is connected to the receiving means 88 and the filter 96. The amplifier 94 amplifies the optical signal J received by the receiving means 88 and transmits it to the filter 96. For example, an amplifier can be used as the amplifier 94.

  The filter 96 is connected to the amplifier 94 and the detection means 98. The filter 96 removes noise from the optical signal J amplified by the amplifier 94. As the filter 96, for example, a band pass filter can be used.

  The detection means 98 is connected to the filter 96 and the clock detection means 99. The detecting means 98 is for demodulating the amplified optical signal J and transmitting the demodulated optical signal J to the clock detecting means 99.

  The clock detection means 99 is connected to the detection means 98 and the synchronization means 101. The clock detection means 99 is for detecting a clock signal included in the demodulated optical signal J. The optical signal J from which the clock signal has been detected is transmitted to the synchronization means 101.

  The synchronization unit 101 is connected to the clock detection unit 99 and the drive circuit 103. The synchronization unit 101 synchronizes the optical signal J with the clock signal detected by the clock detection unit 99 and transmits the synchronized optical signal J to the drive circuit 103.

  The storage means 102 is for storing unique ID information and is connected to the drive circuit 103. The unique ID information is, for example, information such as a unique number uniquely assigned to the reflecting means 85 or a solid information number unique to the object 24 on which the reflecting means 85 is provided.

  The drive circuit 103 is connected to the synchronization unit 101, the storage unit 102, and the opening / closing unit 91.

  According to the position detection device 80 of the present embodiment, when there are a plurality of objects 24 including the reflection means 85 in the irradiation region P of the optical signal J, the opening / closing means 91 of all the reflection means 85 are first turned on by light. Each control unit 93 performs control so as to cut off the signal J, and then, after a suitable time has passed, each open / close means 91 is controlled so as to reflect the optical signal J, so that it is reflected from each reflective means 85. The positions of the plurality of objects 24 in the three-dimensional space can be detected without the temporal overlap of the optical signals K.

  When a method for measuring the propagation time of pulsed light instead of the modulation method is used as the propagation distance calculating unit 45, a pulse position modulation method (PPM) for selecting pulsed light to be passed by the opening / closing unit 91 is used as the communication method. You may use together. By using the pulse position modulation method (PPM) together, ID information, control information, and the like can be transmitted to and received from the object 24.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and within the scope of the present invention described in the claims, Various modifications and changes are possible. Note that the image sensor (for example, CCD) may be used to directly observe the spot images of the optical signals C and K to detect the position of the center of gravity of the optical signals C and K.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a position detection device that can determine the position of an object with high accuracy and can be miniaturized.

It is a schematic block diagram of the position detection apparatus of 1st Embodiment. It is sectional drawing of a reflection means. It is the perspective view which expanded the reflective sheet. It is a perspective view of a 1st light receiving element. It is a figure for demonstrating how to obtain | require the position in the three-dimensional space of a target object. It is a schematic block diagram of the position detection apparatus of 2nd Embodiment. It is a schematic block diagram of the position detection apparatus of 3rd Embodiment. It is a block diagram of the optical signal generation part of this Embodiment. It is a schematic block diagram of a reflection means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 60, 80 Position detection apparatus 11, 61, 81 Apparatus main body 12, 62 Calculation means 13 Information terminal 14, 82 Optical signal generation part 15 Light source 16 Light source drive part 18 Optical signal modulation means 19 Optical signal control means 20 Condensing lens 21 First Separating Unit 21A, 23A, 65A Surface 22, 85 Reflecting Unit 23 Sheet-like Substrate 24 Object 25 Reflecting Sheet 26 First Light-Receiving Element 26A, 66A Light-Receiving Surface 27 Electrode 28 Reflector 28A Reflecting Surface 29A-29D , 71, 94 Amplifiers 31A to 31D, 72, 96 Filter 33 Output current receiving means 34 Detector 35 Determinator 36 Synchronizer 37 Demodulator 41 Reflection position calculator 42 Reflection position calculator 43, 47 A / D converter 45 Propagation Distance calculation means 46 Synchronous detection section 48 Propagation distance calculation section 50 Object position calculation means 51 Correction means 5 Storage unit 53 Correction unit 65 Second separation unit 66 Second light receiving element 67 Condensing lens 83 Clock generation unit 84 Device ID information providing unit 88 Reception unit 91 Opening / closing unit 93 Control unit 98 Detection unit 99 Clock detection unit 101 Synchronization unit 102 storage means 103 drive circuit A, C, D, J, K optical signal B, P irradiation area d, L, M, N distance E mirror image position F spot image G1, G2 barycentric position H intersection V direction vector

Claims (6)

In a position detection device that detects the position of an object,
A light source that emits an optical signal;
Reflecting means attached to the object and having a reflecting surface for reflecting the optical signal;
First separating means for separating the optical signal and the optical signal reflected by the reflecting means;
A first light receiving element for receiving the reflected optical signal;
Second separation means for passing the optical signal to the first light receiving element side and directing a part of the optical signal to the second light receiving element;
The second light receiving element that receives a part of the optical signal separated by the second separating means, having a light receiving surface area smaller than that of the first light receiving element and having a high response speed;
Reflection position calculation means for determining the position of the reflected optical signal on the light receiving surface of the first light receiving element based on the output signal of the first light receiving element;
Propagation distance calculation means for obtaining a propagation distance from the light source to the second light receiving element ;
An object for determining the position of the object based on the position of the reflected optical signal on the light receiving surface of the first light receiving element determined by the reflection position calculating means and the propagation distance determined by the propagation distance calculating means. An object position calculating means ;
A control unit,
The reflecting means is
Opening and closing means provided so as to cover the reflecting surface of the reflecting means;
The position detection device , wherein the control unit controls the opening / closing means to reflect the optical signal after controlling the opening / closing means to block the optical signal . Having optical signal modulation means,
The position detection apparatus according to claim 1, wherein the optical signal modulation unit modulates any one of an intensity, a phase, and a frequency of the optical signal. Comprising a plate-like member having an opening,
The position detection apparatus according to claim 1, wherein the plate-like member is arranged so that a mirror image position of the light source is accommodated in the opening. Having correction means,
The correction means obtains correction data based on a difference between reference data obtained in advance and data when an object is placed at a predetermined position;
The position detection device according to any one of claims 1 to 3 , wherein the object position calculation means obtains a corrected position of the object based on the correction data. The optical path of the optical path and / or reflected light signal of the optical signal, the position of any one of claims 1 to 4, characterized by providing a light shielding means for blocking light other than the wavelength of the light source Detection device. The light source position detecting device according to any one of claims 1 to 5, characterized in that irradiation with infrared light.

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