WO2010146950A1 - Light point position detection device - Google Patents

Light point position detection device Download PDF

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Publication number
WO2010146950A1
WO2010146950A1 PCT/JP2010/058009 JP2010058009W WO2010146950A1 WO 2010146950 A1 WO2010146950 A1 WO 2010146950A1 JP 2010058009 W JP2010058009 W JP 2010058009W WO 2010146950 A1 WO2010146950 A1 WO 2010146950A1
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WO
WIPO (PCT)
Prior art keywords
light
spot
light receiving
screen
receiving element
Prior art date
Application number
PCT/JP2010/058009
Other languages
French (fr)
Japanese (ja)
Inventor
伊作 永井
Original Assignee
国立大学法人岡山大学
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Publication date
Application filed by 国立大学法人岡山大学 filed Critical 国立大学法人岡山大学
Priority to JP2011519684A priority Critical patent/JP5429897B2/en
Publication of WO2010146950A1 publication Critical patent/WO2010146950A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/16—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using electromagnetic waves other than radio waves
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/0304—Detection arrangements using opto-electronic means
    • G06F3/0325—Detection arrangements using opto-electronic means using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • G01J1/4257—Photometry, e.g. photographic exposure meter using electric radiation detectors applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
    • G01S11/12—Systems for determining distance or velocity not using reflection or reradiation using electromagnetic waves other than radio waves

Definitions

  • the present invention relates to a light spot position detection device that detects the position of a light spot displayed on a screen by spot light irradiated from a light source toward the screen.
  • a detection device using a laser beam may be used for detecting a vibration state or a bending state of a bridge or detecting a displacement state of a slope such as a cliff.
  • laser light is spot light
  • a light spot appears when the subject is irradiated with laser light.
  • PSD Position Sensitive Device
  • a photodiode, a phototransistor, or the like is used to detect a change in the position of a light spot.
  • Detectors arranged in a grid pattern are used (for example, see Patent Document 2), or image processing is performed after taking a light spot with an imaging device such as a camera.
  • the PSD it is difficult for the PSD to increase the area of the laser light receiving portion where the light spot is displayed, and it cannot be used in a very bright place such as outdoors, or readjustment is necessary. There was a problem that.
  • optical sensors are easily affected by incident angle characteristics, and are difficult to use in environments where the brightness varies greatly, such as outdoors, and when a light spot is located between adjacent optical sensors. Therefore, it is difficult to detect correctly, and since the resolution depends on the size of the optical sensor, it is difficult to increase the resolution, and the performance is not sufficient.
  • the imaging device captures the light spot, it is often difficult to optimize the shooting conditions in extremely bright places such as outdoors or where the brightness changes, and the usage environment is limited. There was a problem of being.
  • the present inventor has conducted research and development to provide a light spot position detecting device that is relatively inexpensive and hardly affected by the environment, and has achieved the present invention. .
  • the light spot position detection device of the present invention includes a light source for irradiating spot light, and detection means for receiving the spot light emitted from the light source by the screen and detecting the position of the light spot by the spot light appearing on the screen.
  • a light spot position detecting device having a light receiving device, wherein the screen is made of a diffuse transmission material, and the detecting means includes a plurality of light receiving elements provided on the back side of the screen, and output signals from these light receiving elements.
  • an analysis unit for analyzing the above.
  • the light spot position detecting device of the present invention is also characterized by the following points.
  • the light source irradiates the spot light as pulses.
  • the light source includes a control unit that adjusts the duty ratio of the pulsed spot light and transmits a predetermined signal, and the analysis unit of the detection unit transmits the signal by reading the signal from the spot light.
  • the central axis at which the light incident angle of the light receiving element is 0 degrees is orthogonal to the screen, and a shield is provided on the central axis.
  • the light receiving element is provided in a box-shaped housing on which a screen is stretched, and an illuminator that makes the inside of the housing have a predetermined brightness is provided in the housing.
  • a light source that irradiates spot light
  • a light receiver that includes spot light irradiated from the light source, and a detector that detects a position of a light spot by the spot light that appears on the screen
  • the screen Since the screen is made of a diffuse transmission material, it can be made less susceptible to environmental influences such as direct sunlight.
  • the detection means is composed of a plurality of light receiving elements provided on the back side of the screen and an analysis unit for analyzing the output signal from each of these light receiving elements.
  • the number can be set to 4 and at most 10 or less, and the detection means can be configured with a small number of light receiving elements, so that the cost can be extremely low.
  • the detection means detects the position of the light spot appearing on the screen by analyzing the output signal from each light receiving element in the analysis unit, the resolution can be increased.
  • the light spot position detection device of the present invention includes a light source for irradiating spot light, and detection means for receiving the spot light emitted from the light source on the screen and detecting the position of the light spot by the spot light appearing on the screen. It consists of a receiver.
  • a spot is emitted from the light source to generate a light spot on the screen of the light receiver, and the resolution is lowered by detecting the position of this light spot by the detector of the light receiver. It is possible to detect.
  • the detection means is composed of a plurality of light receiving elements provided on the back side of the screen and an analysis unit for analyzing the output signal from each of the light receiving elements, so that it is not easily affected by the environment such as direct sunlight.
  • the position of the light spot can be detected with a relatively small number of light receiving elements.
  • the position of the light spot can be detected by at least three, preferably four light receiving elements.
  • the detection range of the position of the light spot can be set to a desired detection range by adjusting the size of the screen, and the desired detection accuracy can be obtained by appropriately arranging the light receiving elements according to the size of the screen. Can be obtained.
  • the screen is not limited to a flat shape, and may be a spherical shape, for example, and can have an appropriate shape.
  • the light receiving element may be provided in a box-shaped housing on which a screen is stretched, and an illuminator having a predetermined brightness in the housing may be provided in the housing. That is, in general, the detection means of the light receiver is very inferior in sensitivity to illuminance below a certain level, and there is a risk that the detection accuracy of the position of the light spot may be lowered. By setting the brightness to a predetermined level, it is possible to increase the detection accuracy of the position of the light spot by setting the detection means to a state with high detection sensitivity.
  • the light source does not necessarily have to be in an on state in which spot light is always irradiated, and may be irradiated in a so-called pulse shape that alternately repeats an on state in which spot light is irradiated and an off state in which spot light is not irradiated. Good.
  • the amount of light detected by each light receiving element in the off state of the spot light is set as the amount of background light, and from the amount of light detected by each light receiving element in the on state of the spot light, the background By subtracting the amount of light, it is possible to easily eliminate the influence of background light and to make it less susceptible to environmental influences such as direct sunlight.
  • a predetermined signal can be transmitted and a communication function can be provided.
  • the light spot position detecting device receives a light source 10 that irradiates a spot light L, a spot light L emitted from the light source 10 by a screen 25, and a spot light L that appears on the screen 25.
  • the light receiving device 20 is provided with detection means for detecting the position of the light spot.
  • Any light source device may be used as the light source 10 as long as it can irradiate light with high convergence.
  • a light source device that irradiates laser light is suitable, and a laser light source is also used in this embodiment.
  • the light source 10 emits light in a so-called pulse shape that alternately repeats an on state in which spot light is irradiated and an off state in which spot light is not irradiated.
  • the background light component can be easily removed in the light receiver 20 and the detection accuracy of the light spot is improved.
  • the frequency of the spot light may be an appropriate frequency that is not easily affected by the background light.In the case of this embodiment, the frequency was originally set to 520 Hz. I was able to eliminate the effect.
  • the light receiver 20 includes a rectangular housing 26, a screen 25 mounted in an opening 26 a provided on one surface of the housing 26, and first to fourth light receiving elements 21, 22, 23, mounted in the housing 26. 24 and an analyzer 27 for analyzing the signals output from the first to fourth light receiving elements 21, 22, 23, 24.
  • the housing 26 is not limited to a rectangular shape, and may have an appropriate shape. In this embodiment, since it is easy to manufacture, it is a rectangular body. In this embodiment, as will be described later, since the housing 26 is also used as a support for the screen 25 and the first to fourth light receiving elements 21, 22, 23, 24, a material having a certain degree of rigidity is used. 25 and the first to fourth light receiving elements 21, 22, 23, 24 can be stably fixed and supported. In the present embodiment, the fourth light receiving element 24 is provided at a diagonal position in the rectangular housing 26 with respect to the first light receiving element 21, and the second light receiving element 22 and the third light receiving element 22 are provided at the remaining two corners. A light receiving element 23 is provided.
  • the opening 26 a provided in the housing 26 is provided in a rectangular shape on one of the six surfaces of the housing 26.
  • the opening shape of the opening 26a is not limited to a rectangular shape, and may be an appropriate shape in consideration of the variation state of the position of the detected light spot.
  • a frame-shaped outer edge 26b is formed along the periphery of the opening 26a along with the formation of the opening 26a. It has become.
  • the sheet-like screen 25 is disposed in the housing 26 so as to close the opening 26a, and the outer peripheral edge of the screen 25 is overlaid on the outer edge 26b of the housing 26 and bonded using an adhesive or the like.
  • the screen 25 is made of a diffuse transmission material.
  • the screen 25 is a plastic plate.
  • the screen 25 is red in order to easily generate a clear light spot by the spot light L emitted from the light source 10. Any screen 25 may be used as long as a clear light spot can be generated by the spot light L emitted from the light source 10.
  • the first to fourth light receiving elements 21, 22, 23, and 24 are phototransistors of the same model number, and are fixedly attached to the four corners of a rectangular housing 26, respectively.
  • the first to fourth light receiving elements 21, 22, 23, and 24 are provided toward the screen 25 with the central axis S having a light incident angle of 0 degrees orthogonal to the screen 25, and the central axis A shield is provided on S.
  • a general phototransistor can output a voltage that is almost directly proportional to the amount of received light, but has a directivity characteristic, and therefore, as shown in FIG. On the other hand, the output voltage is reduced. Further, when the center axis S of the phototransistor is orthogonal to the screen 25 as in the present embodiment, the distance between the light spot and the phototransistor increases as the position of the light spot moves away from the center axis S. The increase in the output voltage also causes a decrease in the output voltage with respect to the light spot at a position away from the central axis S.
  • a shield is provided on the central axis S of the first to fourth light receiving elements 21, 22, 23, 24 to suppress light reception in a region where the detection accuracy is lowered, and the output voltage with respect to the position variation of the light spot.
  • the first to fourth light receiving elements 21, 22, 23, 24 are mounted on the housing 26 with the central axis S orthogonal to the outer edge portion 26b of the housing 26, whereby the outer edge portion 26b of the housing 26 is shielded. Further, intervals between the light receiving elements 21, 22, 23, 24 are set.
  • the first to fourth light receiving elements 21, 22, 23, 24 can be mounted while being securely fixed by being mounted at the four corners of the housing 26, and the optical axis is attached to the outer edge portion 26 b of the housing 26. It is easy to make it orthogonal.
  • a light-shielding sheet may be disposed on the central axis S of the first to fourth light receiving elements 21, 22, 23, 24.
  • the analysis device 27 that analyzes the signals output from the first to fourth light receiving elements 21, 22, 23, and 24 is a personal computer in which a predetermined analysis program is installed.
  • a signal input to the personal computer is A / D converted and amplified by a predetermined signal adjustment circuit (not shown).
  • FIG. 3 is a schematic circuit diagram of the signal adjustment circuit of the present embodiment, in which the output voltage of the phototransistor PT is amplified by the operational amplifier OP and output.
  • An AC coupling capacitor C is provided between the phototransistor PT and the operational amplifier OP, and only the AC component of the signal output in an AC shape from the phototransistor PT is converted into spot light by making the spot light into a pulse shape. As a signal based on. Thereby, the background light component contained in the signal output from the phototransistor PT can be removed.
  • a first variable resistor VR1 for offset adjustment is connected to the positive input terminal of the operational amplifier OP, and the offset voltage of the signal output from the operational amplifier OP, that is, the minimum voltage in the output pulse-shaped signal, The magnitude of the voltage that is the middle of the maximum voltage can be adjusted. Therefore, the influence of background light can be easily eliminated, and it can be used in various environments.
  • the output voltage of the phototransistor PT detected in the off state where no spot light is irradiated is the photovoltage detected in the on state where the spot light is irradiated as the output voltage caused by the background light.
  • the influence of background light can also be removed by subtracting from the output voltage of the transistor PT.
  • R1 is a first resistor connected in series to the phototransistor PT
  • R2 and VR2 are a second resistor and a second variable resistor that adjust the output of the operational amplifier OP.
  • the second variable resistor VR2 By adjusting the second variable resistor VR2, the amplitude of the signal output from the operational amplifier OP can be adjusted, and can be adjusted to a signal suitable for signal analysis in the analysis device 27.
  • the signal adjustment circuit is not limited to the form shown in FIG. 3 and can have an appropriate circuit configuration.
  • the signal adjustment circuit shown in FIG. 3 is a non-inverting amplifier circuit using the operational amplifier OP, but may be a signal adjustment circuit including an inverting amplifier circuit as shown in FIG.
  • the output voltage of the phototransistor PT ′ is amplified by the operational amplifier OP ′, and an AC coupling capacitor C1 ′ is provided between the phototransistor PT ′ and the operational amplifier OP ′.
  • R1 ′ is a first resistor connected in series to the phototransistor PT ′
  • R2 ′ and R3 ′ are a second resistor and a second variable resistor that adjust the output of the operational amplifier OP ′.
  • a fourth resistor R4 'and a fifth resistor value R5' having the same resistance value connected in series between the power supply voltage and the ground voltage are provided, and this fourth resistor R4 is provided.
  • Vcc / 2 [V] is input to the operational amplifier OP ′ by connecting the “+” and the fifth resistance value R5 ′ to the positive input terminal of the operational amplifier OP ′.
  • the center of the amplitude of the output signal of the phototransistor PT ′ having an AC shape can be easily adjusted to Vcc / 2 [V], and adjustment of the offset voltage by the first variable resistor VR1 is unnecessary. be able to.
  • C2 ′ is a stabilization capacitor provided to suppress fluctuations in the voltage input to the positive input terminal of the operational amplifier OP ′.
  • the thickness of the screen 25 and the resistance values of the first resistors R1 and R1 ′ are appropriately adjusted according to the illuminance of the light source 10, the illuminance of the background light, or the distance from the light source 10 to the screen 25 of the light receiver 20. By doing so, the output signals of the phototransistors PT and PT ′ can be effectively amplified by the signal adjustment circuit.
  • an output voltage of a signal output from the first to fourth light receiving elements 21, 22, 23, 24 is analyzed by the analyzing device 27. 2 is specified, and the distance from each light receiving element 21, 22, 23, 24 to the light spot is specified based on the output characteristic curve of FIG. Is drawn in each of the light receiving elements 21, 22, 23, and 24, and the position of the light spot can theoretically be specified as the position of the intersection of the four virtual circles.
  • the four virtual circles do not intersect at a single point due to the effects of various errors, especially when the illuminance of the light source fluctuates.
  • the output voltage of the signal fluctuates, so that it may be recognized that the position of the light spot fluctuates.
  • the output voltage of the signal output from each of the light receiving elements 21, 22, 23, 24 is in a state multiplied by a substantially equivalent rate of change, Multiply the output voltage of each light receiving element 21, 22, 23, 24 by the rate of change k, and specify the rate of change k where the four virtual circles intersect at one point while changing the value of the rate of change k, and determine the position of the light spot Can be identified.
  • the virtual circle s1 centered on the first light receiving element 21 is used.
  • a fourth intersection point p4 that is an intersection point of the virtual circle s3 centering on 23 and the virtual circle s4 centering on the fourth light receiving element 24 is specified.
  • the first to fourth intersections p1, p2, p3, p4 are identified using the specified value of the change rate k, and the average value of the coordinates of the identified first to fourth intersections p1, p2, p3, p4 is determined.
  • the specified coordinates are used as the position of the intersection.
  • the position where the light receiving elements are internally divided by the radius ratio of the virtual circle Coordinates may be used as intersections and positions, or intersections may always exist by multiplying in advance by the value of the rate of change k where k> 1.
  • the coordinates of the intersection may be specified using the ratio of the output voltages of the signals output from the light receiving elements 21, 22, 23, and 24, respectively.
  • the opening 26a provided in the housing 26 has a square shape of 6 cm square, and a 5 cm square detection similar to the opening 26a with the center of the opening 26a as the center.
  • An area is assumed, and as shown in FIG. 6, measurement points t are set in the detection area in a grid of 5 mm intervals, and output voltage data of each measurement point t in total 121 points are measured in advance.
  • the output voltage value of the first light receiving element 21 at each measurement point t is v1
  • the output voltage value of the second light receiving element 22 is v2
  • the output voltage value of the third light receiving element 23 is v3
  • the fourth light receiving element 24 The output voltage value is represented as v4.
  • the interval between the measurement points is not limited to 5 mm, and may be an arbitrary interval, and the detection area may be larger than 5 cm square.
  • the first to fourth light receiving elements 21, 22, 23, and 24 are arranged at the apexes of a 7 cm square having a shape similar to the opening 26a with the center of the opening 26a as the center.
  • reference data rv1, rv2, rv3, rv4, which are ratios of output voltages, are specified from the output voltage values v1, v2, v3, v4 of the respective light receiving elements 21, 22, 23, 24 by the following expression.
  • rv1 v1 / (v1 + v2 + v3 + v4)
  • rv2 v2 / (v1 + v2 + v3 + v4)
  • rv3 v3 / (v1 + v2 + v3 + v4)
  • rv4 v4 / (v1 + v2 + v3 + v4).
  • the reference data rv1, rv2, rv3, rv4 are provided in the analysis device 27 in advance as a database, and the signals output from the first to fourth light receiving elements 21, 22, 23, 24 are used when detecting the position of the light spot.
  • the output voltage ratio data rv1 ′, rv2 ′, rv3 ′, and rv4 ′ are specified by performing the same calculation as the above-described expression using the output voltage value.
  • D
  • the measurement point t having the minimum value of D is specified as follows, and the specified measurement point t is set as the position of the light spot.
  • the lattice point that is generated and minimizes the value of the SAD correlation D with respect to this reference data is set as the position of the light spot. Therefore, the resolution of the position of the light spot can be set to 0.5 mm.
  • the light receiver 20 of the present embodiment does not need to face the light source 10, and the spot light may be incident on the screen 25 from a predetermined angle other than 90 °.
  • the receiver 20 can be any distance from the light source 10 as long as a point can be generated.
  • the spot light is pulsed, but the light source 10 is provided with adjusting means for adjusting the duty ratio by pulse-modulating the spot light to be irradiated in a pulse shape, not only in a pulse shape, You may adjust suitably the time interval of the ON state which irradiates spot light, or the time interval of the OFF state which does not irradiate spot light.
  • the analyzer 27 of the light receiver 20 outputs the output voltage of the signal output from each of the light receiving elements 21, 22, 23, and 24, respectively.
  • binary data can be transmitted and received by serial communication by identifying the first irradiation pattern and the second irradiation pattern.
  • the analysis device 27 of the light receiver 20 identifies the first irradiation pattern as “1” data and the second irradiation pattern as “0” data, or vice versa.
  • binary data identification is not performed based only on the difference in duty ratio, but serial communication may be performed using the variation in illuminance by adjusting the illuminance of the spot light.
  • a timing generation circuit or the like generally used for generating a predetermined timing signal can be used, and the timing generation circuit based on separately input data And the like, and a desired spot light can be emitted from the light source 10 based on the control signal.
  • an illuminator 28 having a predetermined brightness is provided inside a box-shaped housing 26 on which a screen 25 is stretched. Also good.
  • the illuminator 28 includes four light emitting diodes of first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4, and the first to fourth light emitting diodes 28- 1, 28-2, 28-3, and 28-4 are provided in the central portion of the housing 26, and the first light emitting diode 28-1 is disposed toward the first light receiving element 21, and the second light emitting diode 28-2 is provided. Is disposed toward the second light receiving element 22, the third light emitting diode 28-3 is disposed toward the third light receiving element 23, and the fourth light emitting diode 28-4 is disposed toward the fourth light receiving element 24. Has been established.
  • first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4 are disposed closer to the screen 25 than the first to fourth light receiving elements 21, 22, 23, 24.
  • the 1 to 4 light receiving elements 21, 22, 23, 24 can be effectively illuminated.
  • the light receiver 20 is installed and used in a relatively dark environment such as at night or in a tunnel. Even in this case, sufficient accuracy can be maintained with respect to the detection of the position of the light spot.
  • the first to fourth light receiving elements 21, 22, 23, and 24 generally have extremely low sensitivity to illuminance below a certain level, and the linearity of the amount of change in output voltage with respect to illuminance change is poor.
  • the detection accuracy of the position of the point may be lowered, by illuminating the first to fourth light receiving elements 21, 22, 23, and 24 with the illuminator 28, the amount of change in the output voltage with respect to the change in illuminance can be reduced.
  • the position of the light spot can be detected using a region with good linearity, and the detection accuracy can be improved.
  • the illuminator 28 uses the first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4, but the first to fourth light receiving elements 21, 22, 23,
  • the illuminator 28 can be anything as long as the response characteristics of 24 can be improved.
  • the first to fourth light receiving elements 21, 22, 23, and 24 are provided in the rectangular housing 26, and the rectangular detection region is provided.
  • the present invention is not limited to this embodiment. Instead, as shown in FIG. 8, a rectangular-shaped housing 40 extending in one direction is provided with a screen 41 in the form of a narrow band, and a first light receiving element 42 and a second light receiving element are disposed at both ends of the housing 40 in the longitudinal direction.
  • the element 43 may be provided to have a linear detection region.
  • a triangular screen 51 is provided on one surface of a triangular prism-shaped housing 50, and a first light receiving element 52 and a second light receiving element 53 are provided at three corners of the other surface.
  • a third light receiving element 54 may be provided so as to have a triangular detection region, or a hexagonal screen 61 is provided on one surface of a hexagonal columnar housing 60 as shown in FIG.
  • the first light receiving element 62, the second light receiving element 63, the third light receiving element 64, the fourth light receiving element 65, and the fifth light receiving element 66 are provided at the six corners of the other surface.
  • a sixth light receiving element 67 may be provided to have a hexagonal detection region.
  • a circumferential screen 71 is provided on the peripheral surface portion of the cylindrical housing 70, and a first light receiving element 72 is provided on one end surface portion of the cylindrical housing 70.
  • a second light receiving element 73 is provided on the other end surface portion of the cylindrical housing 70, and in particular, the first light receiving element 72 and the second light receiving element 73 are provided to face each other to form a circumferential surface. You may make it have this detection area
  • a spherical screen 81 is provided at the top of a hemispherical housing 80 having an opening at the top, and a first light receiving element 82 and a first light receiving element 82 are provided at the center of the hemispherical housing 80.
  • the two light receiving elements 83 and the third light receiving element 84 may be arranged with their center axes orthogonal to each other so as to have a spherical detection region.
  • the light spot detection region can be formed in an appropriate shape as necessary, and the light receiving elements may be appropriately arranged in accordance with the shape of the detection region.
  • the light spot position detection apparatus configured in this way can be used for displacement measurement of structures such as bridges, deformation detection of slopes such as cliffs, etc., as schematically shown in FIG.
  • the first light source 93a is provided at a predetermined position of the bridge portion 90 laid between the first pier 91 and the second pier 92.
  • the first light receiver 93b is provided at a position separated by a predetermined distance from the first light source 93a
  • the second light source 94a is provided in the vicinity of the first light receiver 93b
  • the second light source 94a is provided.
  • the second light receiver 94b is provided at a position separated from the third light source 94b by a predetermined distance, and a third light source 95a is provided in the vicinity of the second light receiver 94b, and the third light source 95a is spaced from the third light source 95a by a predetermined distance. Is provided with a third light receiver 95b.
  • first light source 93a, the second light source 94a, and the third light source 95a are each provided with adjusting means for adjusting the duty ratio by pulse-modulating the spot light to be irradiated.
  • the light receiver 93b, the second light receiver 94b, and the third light receiver 95b are provided with an analysis unit that reads binary data from the pulsed spot light emitted from the light sources 93a, 94a, and 95a. ing.
  • the 1st light receiver 93b and the 2nd light source 94a are connected by the 1st connection wiring 96, the signal output from the 1st light receiver 93b is input into the 2nd light receiver 94b, The output signal of the first light receiver 93b can be transmitted to the second light receiver 94b.
  • the second light receiver 94b and the third light source 95a are connected by the second connection wiring 97, and the signal output from the second light receiver 94b is input to the third light receiver 95b.
  • the output signal of the first light receiver 93b and the output signal of the second light receiver 94b are transmitted to the third light receiver 95b, and the output signal of each of the light receivers 93b, 94b, 95b is transmitted from the third light receiver 95b. So that you can get.
  • the light spot position detection device of the present invention can be used not only for detecting changes in a structure but also for a shooting game using a model gun capable of irradiating laser light, or a patent. It can be used as a light receiving unit when guiding a moving object using laser light as described in Document 2.

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  • Length Measuring Devices By Optical Means (AREA)

Abstract

Provided is a light point position detection device which is relatively inexpensive and is not readily affected by the environment. The light point position detection device has a light source (10) for irradiating spot light (L), and a light receiver (20) provided with a detection means which receives the spot light (L) radiated from the light source (10) on a screen (25) and detects the position of the light point using the spot light (L) appearing on the screen (25). The screen (25) is constructed from a diffusely transparent material. The detection means is provided with a plurality of photoreceptor elements (21,22,23,24) arranged behind the screen (25) and an analysis unit for analyzing the output signals from the photoreceptor elements (21,22,23,24).

Description

光点位置検出装置Light spot position detector
本発明は、光源からスクリーンに向けて照射したスポット光によってスクリーン上に表示した光点の位置を検出する光点位置検出装置に関するものである。 The present invention relates to a light spot position detection device that detects the position of a light spot displayed on a screen by spot light irradiated from a light source toward the screen.
従来、例えば橋梁の振動状態あるいは撓み状態の検出や、崖などの斜面の変位状態の検出などにレーザ光を利用した検出装置が用いられることがある。 Conventionally, for example, a detection device using a laser beam may be used for detecting a vibration state or a bending state of a bridge or detecting a displacement state of a slope such as a cliff.
特に、レーザ光はスポット光となっているので、被検体にレーザ光を照射すると光点が現れ、この光点の位置の変動を検出することによって被検体あるいはレーザ光の光源の位置変動を検出可能としている。 In particular, since laser light is spot light, a light spot appears when the subject is irradiated with laser light. By detecting the change in the position of the light spot, the position change of the subject or the laser light source is detected. It is possible.
このようなレーザ光を用いた装置において、光点の位置の変動を検出する場合には、ＰＳＤ（Position Sensitive Device）を用いたり（例えば、特許文献１参照。）、あるいはフォトダイオードやフォトトランジスタなどの光センサを格子状に並べて構成した検出器を用いたり（例えば、特許文献２参照。）、カメラなどの撮像装置で光点を撮影した後に画像処理したりすることが行われていた。 In such an apparatus using laser light, PSD (Position Sensitive Device) is used (for example, see Patent Document 1), or a photodiode, a phototransistor, or the like is used to detect a change in the position of a light spot. Detectors arranged in a grid pattern are used (for example, see Patent Document 2), or image processing is performed after taking a light spot with an imaging device such as a camera.
特開２０００－１６１９１１号公報JP 2000-161911 A 特開平０７－２１８２２５号公報JP 07-218225 A
しかしながら、ＰＳＤを用いた場合では、計測精度や計測速度の面では所望の特性を有している一方で、ＰＳＤ自体が非常に高価であるために装置全体の価格が極めて高くなって、一般的な利用にはコスト的に見合わないものとなっていた。 However, in the case of using PSD, while it has desired characteristics in terms of measurement accuracy and measurement speed, since the PSD itself is very expensive, the price of the entire apparatus becomes very high, and in general, It was not worth the cost for a reasonable use.
しかも、ＰＳＤは、光点が表示されるレーザ光の受光部分を大面積化することが困難であり、また、屋外のような非常に明るい場所では使用できなかったり、あるいは再調整が必要であったりするという問題があった。 Moreover, it is difficult for the PSD to increase the area of the laser light receiving portion where the light spot is displayed, and it cannot be used in a very bright place such as outdoors, or readjustment is necessary. There was a problem that.
また、複数の光センサを格子状に並べて構成し、最も大きい光量を検出した光センサの位置で光点位置を特定する検出器を用いた場合には、多くの光センサを使用することにより製造コストが高騰しやすく、低コスト化することが困難であった。 In addition, when using a detector in which a plurality of photosensors are arranged in a grid and the light spot position is identified at the location of the photosensor that has detected the largest amount of light, it can be manufactured by using many photosensors. Costs are likely to rise, making it difficult to reduce costs.
さらに、光センサは入射角特性の影響を受けやすく、しかも、屋外のように明るさが大きく変化する環境では使用が困難であり、そのうえ、隣り合った光センサの間に光点が位置する際には正しい検出が困難であり、分解能が光センサの大きさに依存するために高分解能化が困難であって、性能的にも十分なものではなかった。 Furthermore, optical sensors are easily affected by incident angle characteristics, and are difficult to use in environments where the brightness varies greatly, such as outdoors, and when a light spot is located between adjacent optical sensors. Therefore, it is difficult to detect correctly, and since the resolution depends on the size of the optical sensor, it is difficult to increase the resolution, and the performance is not sufficient.
また、光点を撮像装置で撮影した後に画像処理して光点位置を検出する場合には、画像処理の装置にコストがかかるだけでなく、処理時間が大きくなりやすいという問題があった。 In addition, when the light spot position is detected by performing image processing after the light spot is captured by the imaging device, there is a problem that not only the cost of the image processing device is high, but also the processing time tends to be long.
しかも、撮像装置で光点を撮影しているために、屋外のような非常に明るい場所や明るさが変化する場所では撮影条件を最適化させることが困難であることが多く、使用環境が限定されるという問題があった。 Moreover, since the imaging device captures the light spot, it is often difficult to optimize the shooting conditions in extremely bright places such as outdoors or where the brightness changes, and the usage environment is limited. There was a problem of being.
本発明者は、このような現状に鑑み、比較的安価であるとともに、環境の影響を受けにくい光点位置検出装置を提供すべく研究開発を行って、本発明を成すに至ったものである。 In view of such a current situation, the present inventor has conducted research and development to provide a light spot position detecting device that is relatively inexpensive and hardly affected by the environment, and has achieved the present invention. .
本発明の光点位置検出装置では、スポット光を照射する光源と、この光源から照射されたスポット光をスクリーンで受けるとともにスクリーン上に現れたスポット光による光点の位置を検出する検出手段を備えた受光器とを有する光点位置検出装置であって、スクリーンは拡散透過性材で構成し、検出手段は、スクリーンの裏側に設けた複数の受光素子と、これらの各受光素子からの出力信号を解析する解析部とを備えることとした。 The light spot position detection device of the present invention includes a light source for irradiating spot light, and detection means for receiving the spot light emitted from the light source by the screen and detecting the position of the light spot by the spot light appearing on the screen. A light spot position detecting device having a light receiving device, wherein the screen is made of a diffuse transmission material, and the detecting means includes a plurality of light receiving elements provided on the back side of the screen, and output signals from these light receiving elements. And an analysis unit for analyzing the above.
さらに、本発明の光点位置検出装置では、以下の点にも特徴を有するものである。
（１）光源がスポット光をパルス状として照射すること。
（２）光源が、パルス状のスポット光のデューティ比を調整して所定の信号を送信する制御手段を備え、検出手段の解析部が、スポット光から信号を読み出すことにより信号を伝送すること。
（３）受光素子の入光角度が０度となる中心軸をスクリーンと直交させるとともに、中心軸上に遮蔽体を設けていること。
（４）受光素子は、スクリーンが張設された箱状のハウジング内に設け、このハウジング内に、ハウジング内を所定の明るさとする照光器を設けていること。 Furthermore, the light spot position detecting device of the present invention is also characterized by the following points.
(1) The light source irradiates the spot light as pulses.
(2) The light source includes a control unit that adjusts the duty ratio of the pulsed spot light and transmits a predetermined signal, and the analysis unit of the detection unit transmits the signal by reading the signal from the spot light.
(3) The central axis at which the light incident angle of the light receiving element is 0 degrees is orthogonal to the screen, and a shield is provided on the central axis.
(4) The light receiving element is provided in a box-shaped housing on which a screen is stretched, and an illuminator that makes the inside of the housing have a predetermined brightness is provided in the housing.
本発明によれば、スポット光を照射する光源と、この光源から照射されたスポット光をスクリーンで受けるとともにスクリーン上に現れたスポット光による光点の位置を検出する検出手段を備えた受光器とを有する光点位置検出装置とし、スクリーンを拡散透過性材で構成したことにより、直射日光などの環境の影響を受けにくくすることができる。 According to the present invention, a light source that irradiates spot light, and a light receiver that includes spot light irradiated from the light source, and a detector that detects a position of a light spot by the spot light that appears on the screen, and Since the screen is made of a diffuse transmission material, it can be made less susceptible to environmental influences such as direct sunlight.
そして、検出手段を、スクリーンの裏側に設けた複数の受光素子と、これらの各受光素子からの出力信号を解析する解析部とで構成することにより、光点の検出に必要となる受光素子の数を、通常なら４個、多くても１０個以下とすることができ、少ない数の受光素子で検出手段を構成できるので、極めて安価とすることができる。 And the detection means is composed of a plurality of light receiving elements provided on the back side of the screen and an analysis unit for analyzing the output signal from each of these light receiving elements. Normally, the number can be set to 4 and at most 10 or less, and the detection means can be configured with a small number of light receiving elements, so that the cost can be extremely low.
特に、検出手段では、スクリーン上に現れた光点の位置を、解析部において各受光素子からの出力信号を解析することにより検出しているので、高分解能とすることができる。 In particular, since the detection means detects the position of the light spot appearing on the screen by analyzing the output signal from each light receiving element in the analysis unit, the resolution can be increased.
本発明の実施形態にかかる光点位置検出装置の概略説明図である。It is a schematic explanatory drawing of the light spot position detection apparatus concerning embodiment of this invention. 受光素子として用いたフォトトランジスタの出力電圧の特性曲線である。It is a characteristic curve of the output voltage of the phototransistor used as a light receiving element. 受光素子として用いたフォトトランジスタの出力調整に用いた信号調整回路の説明図である。It is explanatory drawing of the signal adjustment circuit used for the output adjustment of the phototransistor used as a light receiving element. 他の実施形態の信号調整回路の説明図である。It is explanatory drawing of the signal adjustment circuit of other embodiment. 光点の位置の特定方法の説明図である。It is explanatory drawing of the identification method of the position of a light spot. 光点の位置の特定方法の説明図である。It is explanatory drawing of the identification method of the position of a light spot. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 他の実施形態の受光器の説明図である。It is explanatory drawing of the light receiver of other embodiment. 本発明の実施形態にかかる光点位置検出装置の利用形態の説明図である。It is explanatory drawing of the utilization form of the light spot position detection apparatus concerning embodiment of this invention.
本発明の光点位置検出装置は、スポット光を照射する光源と、この光源から照射されたスポット光をスクリーンで受けるとともにスクリーン上に現れたスポット光による光点の位置を検出する検出手段を備えた受光器とで構成している。 The light spot position detection device of the present invention includes a light source for irradiating spot light, and detection means for receiving the spot light emitted from the light source on the screen and detecting the position of the light spot by the spot light appearing on the screen. It consists of a receiver.
すなわち、光点位置検出装置では、光源から照射したスポット光によって受光器のスクリーン上に光点を生じさせ、この光点の位置を受光器の検出手段で検出することにより、解像度を低下させることなく検出可能としている。 That is, in the light spot position detection device, a spot is emitted from the light source to generate a light spot on the screen of the light receiver, and the resolution is lowered by detecting the position of this light spot by the detector of the light receiver. It is possible to detect.
特に、検出手段は、スクリーンの裏側に設けた複数の受光素子と、これらの各受光素子からの出力信号を解析する解析部とで構成しているので、直射日光などの環境の影響を受けにくくすることができるとともに、比較的少数の受光素子で光点の位置を検出することができる。 In particular, the detection means is composed of a plurality of light receiving elements provided on the back side of the screen and an analysis unit for analyzing the output signal from each of the light receiving elements, so that it is not easily affected by the environment such as direct sunlight. In addition, the position of the light spot can be detected with a relatively small number of light receiving elements.
具体的には、スクリーンを平面状に設けた場合には、少なくとも３つ、好適には４つの受光素子によって光点の位置を検出することができる。 Specifically, when the screen is provided in a planar shape, the position of the light spot can be detected by at least three, preferably four light receiving elements.
しかも、光点の位置の検出範囲は、スクリーンの大きさを調整することによって所望の検出範囲とすることができ、受光素子をスクリーンの大きさに合わせて適宜配置することにより、所望の検出精度を得ることができる。 Moreover, the detection range of the position of the light spot can be set to a desired detection range by adjusting the size of the screen, and the desired detection accuracy can be obtained by appropriately arranging the light receiving elements according to the size of the screen. Can be obtained.
なお、スクリーンは平面状に設けるだけでなく、例えば球面状としてもよく、適宜の形状とすることができる。 Note that the screen is not limited to a flat shape, and may be a spherical shape, for example, and can have an appropriate shape.
また、受光素子は、スクリーンが張設された箱状のハウジング内に設けており、このハウジング内にハウジング内を所定の明るさとする照光器を設けてもよい。すなわち、受光器の検出手段は、一般的に、ある程度以下の照度に対する感度が著しく劣りやすく、光点の位置の検出精度が低下するおそれがあるが、ハウジング内に設けた照光器でハウジング内を所定の明るさとしておくことにより、検出手段を検出感度の高い状態として光点の位置の検出精度を高めることができる。 Further, the light receiving element may be provided in a box-shaped housing on which a screen is stretched, and an illuminator having a predetermined brightness in the housing may be provided in the housing. That is, in general, the detection means of the light receiver is very inferior in sensitivity to illuminance below a certain level, and there is a risk that the detection accuracy of the position of the light spot may be lowered. By setting the brightness to a predetermined level, it is possible to increase the detection accuracy of the position of the light spot by setting the detection means to a state with high detection sensitivity.
さらに、光源は、常にスポット光を照射するオン状態となっている必要はなく、スポット光を照射するオン状態と、スポット光を照射しないオフ状態とを交互に繰り返すいわゆるパルス状として照射してもよい。 Further, the light source does not necessarily have to be in an on state in which spot light is always irradiated, and may be irradiated in a so-called pulse shape that alternately repeats an on state in which spot light is irradiated and an off state in which spot light is not irradiated. Good.
特に、パルス状としてスポット光を照射することにより、スポット光のオフ状態において各受光素子で検出される光量を背景光の光量とし、スポット光のオン状態において各受光素子で検出される光量から背景光の光量分を差し引くことにより背景光の影響を容易に排除でき、直射日光などの環境の影響を受けにくくすることができる。 In particular, by irradiating spot light in a pulse form, the amount of light detected by each light receiving element in the off state of the spot light is set as the amount of background light, and from the amount of light detected by each light receiving element in the on state of the spot light, the background By subtracting the amount of light, it is possible to easily eliminate the influence of background light and to make it less susceptible to environmental influences such as direct sunlight.
さらに、パルス状としたスポット光のデューティ比を調整することにより所定の信号を伝送でき、通信機能を付与することもできる。 Furthermore, by adjusting the duty ratio of the pulsed spot light, a predetermined signal can be transmitted and a communication function can be provided.
以下において、図面に基づいて本発明の実施形態を詳説する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
光点位置検出装置は、図１に示すように、スポット光Ｌを照射する光源10と、この光源10から照射されたスポット光Ｌをスクリーン25で受けるとともにスクリーン25上に現れたスポット光Ｌによる光点の位置を検出する検出手段を備えた受光器20とで構成している。 As shown in FIG. 1, the light spot position detecting device receives a light source 10 that irradiates a spot light L, a spot light L emitted from the light source 10 by a screen 25, and a spot light L that appears on the screen 25. The light receiving device 20 is provided with detection means for detecting the position of the light spot.
光源10は、収束性の高い光を照射できればどのような光源装置を用いてもよいが、レーザ光を照射する光源装置が好適であり、本実施形態でもレーザ光源を用いた。 Any light source device may be used as the light source 10 as long as it can irradiate light with high convergence. However, a light source device that irradiates laser light is suitable, and a laser light source is also used in this embodiment.
特に、光源10は、スポット光を照射するオン状態と、スポット光を照射しないオフ状態とを交互に繰り返すいわゆるパルス状として照射している。 In particular, the light source 10 emits light in a so-called pulse shape that alternately repeats an on state in which spot light is irradiated and an off state in which spot light is not irradiated.
このように、パルス状としてスポット光を照射することにより、後述するように、受光器20において背景光成分の除去を容易として、光点の検出精度を向上させている。なお、スポット光の周波数は、背景光の影響を受けにくい適宜の周波数とすればよく、本実施形態の場合、周波数をもともと520Hzとしていたが、3030Hzに変更することにより蛍光灯に起因したちらつきの影響を解消させることができた。 By irradiating the spot light in the form of pulses in this manner, as will be described later, the background light component can be easily removed in the light receiver 20 and the detection accuracy of the light spot is improved. Note that the frequency of the spot light may be an appropriate frequency that is not easily affected by the background light.In the case of this embodiment, the frequency was originally set to 520 Hz. I was able to eliminate the effect.
受光器20は、矩形体状としたハウジング26と、このハウジング26の一面に設けた開口部26aに装着したスクリーン25と、ハウジング26内に装着した第１～４受光素子21,22,23,24と、これらの第１～４受光素子21,22,23,24から出力された信号を解析する解析装置27とで構成している。 The light receiver 20 includes a rectangular housing 26, a screen 25 mounted in an opening 26 a provided on one surface of the housing 26, and first to fourth light receiving elements 21, 22, 23, mounted in the housing 26. 24 and an analyzer 27 for analyzing the signals output from the first to fourth light receiving elements 21, 22, 23, 24.
ハウジング26は矩形体状に限定するものではなく、適宜の形状としてよい。本実施形態では、製造が容易なことから矩形体状としている。また、本実施形態では、後述するようにハウジング26は、スクリーン25及び第１～４受光素子21,22,23,24の支持体ともしているので、ある程度の剛性を有する素材を用い、スクリーン25及び第１～４受光素子21,22,23,24を安定的に固定支持できるようにしている。なお、本実施形態では、第４受光素子24は、第１受光素子21に対して、矩形状のハウジング26における対角位置に設け、残りの２つの角部に第２受光素子22と第３受光素子23とをそれぞれ設けている。 The housing 26 is not limited to a rectangular shape, and may have an appropriate shape. In this embodiment, since it is easy to manufacture, it is a rectangular body. In this embodiment, as will be described later, since the housing 26 is also used as a support for the screen 25 and the first to fourth light receiving elements 21, 22, 23, 24, a material having a certain degree of rigidity is used. 25 and the first to fourth light receiving elements 21, 22, 23, 24 can be stably fixed and supported. In the present embodiment, the fourth light receiving element 24 is provided at a diagonal position in the rectangular housing 26 with respect to the first light receiving element 21, and the second light receiving element 22 and the third light receiving element 22 are provided at the remaining two corners. A light receiving element 23 is provided.
ハウジング26に設ける開口部26aは、ハウジング26における６面のうちの１面に矩形状に設けている。開口部26aの開口形状も矩形状に限定するものではなく、検出する光点の位置の変動状態を考慮して適宜の形状としてよい。 The opening 26 a provided in the housing 26 is provided in a rectangular shape on one of the six surfaces of the housing 26. The opening shape of the opening 26a is not limited to a rectangular shape, and may be an appropriate shape in consideration of the variation state of the position of the detected light spot.
なお、開口部26aは、ハウジング26における平板状の一側面に設けているため、開口部26aの形成にともなって、開口部26aの周縁に沿って枠状の外縁部26bが形成されることとなっている。 Since the opening 26a is provided on one flat side surface of the housing 26, a frame-shaped outer edge 26b is formed along the periphery of the opening 26a along with the formation of the opening 26a. It has become.
シート状のスクリーン25は、開口部26aを閉塞するようにハウジング26に配置させて、スクリーン25の外周縁をハウジング26の外縁部26bに重ね合わせて、接着剤などを用いて貼り合わせている。 The sheet-like screen 25 is disposed in the housing 26 so as to close the opening 26a, and the outer peripheral edge of the screen 25 is overlaid on the outer edge 26b of the housing 26 and bonded using an adhesive or the like.
スクリーン25は拡散透過性材で構成している。特に、本実施形態では、スクリーン25には、プラスチック板を用いている。また、スクリーン25は光源10から照射されたスポット光Ｌによって鮮明な光点を生じさせやすくするため、赤色としている。なお、光源10から照射されたスポット光Ｌによって鮮明な光点を生じさせることができれば、スクリーン25にはどのようなものを用いてもよい。 The screen 25 is made of a diffuse transmission material. In particular, in the present embodiment, the screen 25 is a plastic plate. Further, the screen 25 is red in order to easily generate a clear light spot by the spot light L emitted from the light source 10. Any screen 25 may be used as long as a clear light spot can be generated by the spot light L emitted from the light source 10.
第１～４受光素子21,22,23,24は、それぞれ同じ型番のフォトトランジスタであって、矩形体状のハウジング26の四隅にそれぞれ固定装着している。 The first to fourth light receiving elements 21, 22, 23, and 24 are phototransistors of the same model number, and are fixedly attached to the four corners of a rectangular housing 26, respectively.
特に、第１～４受光素子21,22,23,24は、入光角度が０度となる中心軸Ｓをスクリーン25に対して直交させながらスクリーン25に向けて設けており、しかも、中心軸Ｓ上には遮蔽体を設けている。 In particular, the first to fourth light receiving elements 21, 22, 23, and 24 are provided toward the screen 25 with the central axis S having a light incident angle of 0 degrees orthogonal to the screen 25, and the central axis A shield is provided on S.
すなわち、一般的なフォトトランジスタでは、受光した光量に対してほぼ正比例の電圧を出力できるが、指向特性を有しているため、図２に示すように、中心軸から離れた位置の光点に対して出力電圧の低下が生じることとなっている。また、本実施形態のように、フォトトランジスタの中心軸Ｓをスクリーン25に直交させている場合には、光点の位置が中心軸Ｓから離れるにつれて、光点とフォトトランジスタとの間の距離が大きくなることによっても、中心軸Ｓから離れた位置の光点に対して出力電圧の低下が生じることとなっている。 That is, a general phototransistor can output a voltage that is almost directly proportional to the amount of received light, but has a directivity characteristic, and therefore, as shown in FIG. On the other hand, the output voltage is reduced. Further, when the center axis S of the phototransistor is orthogonal to the screen 25 as in the present embodiment, the distance between the light spot and the phototransistor increases as the position of the light spot moves away from the center axis S. The increase in the output voltage also causes a decrease in the output voltage with respect to the light spot at a position away from the central axis S.
その一方で、中心軸の近傍では、出力電圧の変化率が小さくなるので、光点の位置変動の検出精度が低下しやすくなっている。 On the other hand, since the rate of change of the output voltage is small in the vicinity of the central axis, the detection accuracy of the position fluctuation of the light spot tends to be lowered.
そこで、第１～４受光素子21,22,23,24の中心軸Ｓ上には遮蔽体を設けて、検出精度が低下する領域での受光を抑制し、光点の位置変動に対する出力電圧の変化率ができるだけ大きい領域を利用して光点の位置を検出することにより、光点の検出精度を高めるようにしている。 Therefore, a shield is provided on the central axis S of the first to fourth light receiving elements 21, 22, 23, 24 to suppress light reception in a region where the detection accuracy is lowered, and the output voltage with respect to the position variation of the light spot. By detecting the position of the light spot using an area where the rate of change is as large as possible, the detection accuracy of the light spot is increased.
すなわち、第１～４受光素子21,22,23,24は、中心軸Ｓをハウジング26の外縁部26bに直交させた状態としてハウジング26に装着することにより、ハウジング26の外縁部26bを遮蔽体として利用し、さらに、各受光素子21,22,23,24間の間隔を設定している。 That is, the first to fourth light receiving elements 21, 22, 23, 24 are mounted on the housing 26 with the central axis S orthogonal to the outer edge portion 26b of the housing 26, whereby the outer edge portion 26b of the housing 26 is shielded. Further, intervals between the light receiving elements 21, 22, 23, 24 are set.
本実施形態では、第１～４受光素子21,22,23,24は、ハウジング26の四隅部分に装着することにより、確実に固定しながら装着できるとともに、光軸をハウジング26の外縁部26bに直交させやすくしている。 In the present embodiment, the first to fourth light receiving elements 21, 22, 23, 24 can be mounted while being securely fixed by being mounted at the four corners of the housing 26, and the optical axis is attached to the outer edge portion 26 b of the housing 26. It is easy to make it orthogonal.
なお、ハウジング26の外縁部26bを遮蔽体として用いるのではなく、遮光性を有するシート体を第１～４受光素子21,22,23,24の中心軸Ｓ上に配設してもよい。 Instead of using the outer edge portion 26b of the housing 26 as a shield, a light-shielding sheet may be disposed on the central axis S of the first to fourth light receiving elements 21, 22, 23, 24.
第１～４受光素子21,22,23,24から出力された信号を解析する解析装置27は、本実施形態では、所定の解析用のプログラムをインストールしたパーソナルコンピュータとしている。 In this embodiment, the analysis device 27 that analyzes the signals output from the first to fourth light receiving elements 21, 22, 23, and 24 is a personal computer in which a predetermined analysis program is installed.
なお、パーソナルコンピュータに入力する信号は、所定の信号調整回路（図示せず）によってＡ／Ｄ変換するとともに増幅している。 A signal input to the personal computer is A / D converted and amplified by a predetermined signal adjustment circuit (not shown).
図３は、本実施形態の信号調整回路の概略的な回路図であり、フォトトランジスタPTの出力電圧をオペアンプOPで増幅して出力している。フォトトランジスタPTとオペアンプOPとの間には、交流結合用コンデンサＣを設けており、スポット光をパルス状としたことによりフォトトランジスタPTから交流状に出力される信号の交流成分のみをスポット光に基づく信号として通過させている。これにより、フォトトランジスタPTから出力された信号に含まれている背景光成分を除去可能としている。 FIG. 3 is a schematic circuit diagram of the signal adjustment circuit of the present embodiment, in which the output voltage of the phototransistor PT is amplified by the operational amplifier OP and output. An AC coupling capacitor C is provided between the phototransistor PT and the operational amplifier OP, and only the AC component of the signal output in an AC shape from the phototransistor PT is converted into spot light by making the spot light into a pulse shape. As a signal based on. Thereby, the background light component contained in the signal output from the phototransistor PT can be removed.
さらに、オペアンプOPのプラス入力端子にはオフセット調整用の第１可変抵抗器VR1を接続して、オペアンプOPから出力される信号のオフセット電圧、すなわち、出力されるパルス状の信号における最小の電圧と最大の電圧の中間となる電圧の大きさを調整可能としている。したがって、背景光の影響を容易に排除でき、様々な環境下で使用できる。 Further, a first variable resistor VR1 for offset adjustment is connected to the positive input terminal of the operational amplifier OP, and the offset voltage of the signal output from the operational amplifier OP, that is, the minimum voltage in the output pulse-shaped signal, The magnitude of the voltage that is the middle of the maximum voltage can be adjusted. Therefore, the influence of background light can be easily eliminated, and it can be used in various environments.
また、パルス状としたスポット光において、スポット光を照射しないオフ状態で検出されたフォトトランジスタPTの出力電圧は、背景光に起因した出力電圧として、スポット光を照射するオン状態で検出されたフォトトランジスタPTの出力電圧から差し引くことによっても背景光の影響を除去できる。 In the pulsed spot light, the output voltage of the phototransistor PT detected in the off state where no spot light is irradiated is the photovoltage detected in the on state where the spot light is irradiated as the output voltage caused by the background light. The influence of background light can also be removed by subtracting from the output voltage of the transistor PT.
なお、図３中、R1はフォトトランジスタPTに直列接続した第１抵抗器であり、R2及びVR2はオペアンプOPの出力を調整している第２抵抗器及び第２可変抵抗器であり、特に、第２可変抵抗器VR2を調整することによりオペアンプOPから出力される信号の振幅を調整でき、解析装置27での信号解析に好適な信号に調整できる。 In FIG. 3, R1 is a first resistor connected in series to the phototransistor PT, and R2 and VR2 are a second resistor and a second variable resistor that adjust the output of the operational amplifier OP. By adjusting the second variable resistor VR2, the amplitude of the signal output from the operational amplifier OP can be adjusted, and can be adjusted to a signal suitable for signal analysis in the analysis device 27.
信号調整回路は、図３に示した形態に限定するものではなく、適宜の回路構成とすることができる。 The signal adjustment circuit is not limited to the form shown in FIG. 3 and can have an appropriate circuit configuration.
すなわち、図３に示した信号調整回路では、オペアンプOPを用いた非反転増幅回路としているが、例えば、図４に示すような反転増幅回路からなる信号調整回路としてもよい。 That is, the signal adjustment circuit shown in FIG. 3 is a non-inverting amplifier circuit using the operational amplifier OP, but may be a signal adjustment circuit including an inverting amplifier circuit as shown in FIG.
図４に示した信号調整回路でも、フォトトランジスタPT'の出力電圧をオペアンプOP'で増幅しており、フォトトランジスタPT'とオペアンプOP'との間には、交流結合用コンデンサC1'を設けている。図４中、R1'はフォトトランジスタPT'に直列接続した第１抵抗器であり、R2'及びR3'はオペアンプOP'の出力を調整している第２抵抗器及び第２可変抵抗器である。 Also in the signal adjustment circuit shown in FIG. 4, the output voltage of the phototransistor PT ′ is amplified by the operational amplifier OP ′, and an AC coupling capacitor C1 ′ is provided between the phototransistor PT ′ and the operational amplifier OP ′. Yes. In FIG. 4, R1 ′ is a first resistor connected in series to the phototransistor PT ′, and R2 ′ and R3 ′ are a second resistor and a second variable resistor that adjust the output of the operational amplifier OP ′. .
図４に示した信号調整回路では、電源電圧と接地電圧間との間で直列接続した同一抵抗値の第４抵抗器R4'と第５抵抗値R5'を設けるとともに、この第４抵抗器R4'と第５抵抗値R5'の間とオペアンプOP'のプラス入力端子とを接続して、オペアンプOP'にVcc/2[V]を入力している。これにより、交流状となっているフォトトランジスタPT'の出力信号における振幅の中央をVcc/2[V]に容易に合わせることができ、第１可変抵抗器VR1によるオフセット電圧の調整を不要とすることができる。 In the signal adjustment circuit shown in FIG. 4, a fourth resistor R4 'and a fifth resistor value R5' having the same resistance value connected in series between the power supply voltage and the ground voltage are provided, and this fourth resistor R4 is provided. Vcc / 2 [V] is input to the operational amplifier OP ′ by connecting the “+” and the fifth resistance value R5 ′ to the positive input terminal of the operational amplifier OP ′. As a result, the center of the amplitude of the output signal of the phototransistor PT ′ having an AC shape can be easily adjusted to Vcc / 2 [V], and adjustment of the offset voltage by the first variable resistor VR1 is unnecessary. be able to.
さらに、オペアンプOP'を用いた反転増幅回路を構成していることにより、交流結合用コンデンサC1'を小容量化することができ、背景光の急激な変動に対する追従性を向上させることができる。図４中、C2'はオペアンプOP'のプラス入力端子に入力される電圧の変動を抑制するために設けた安定化用のコンデンサである。 Furthermore, by configuring an inverting amplifier circuit using the operational amplifier OP ′, it is possible to reduce the capacity of the AC coupling capacitor C1 ′, and to improve the followability to a rapid fluctuation of the background light. In FIG. 4, C2 ′ is a stabilization capacitor provided to suppress fluctuations in the voltage input to the positive input terminal of the operational amplifier OP ′.
また、光源10の照度や、背景光の照度、あるいは光源10から受光器20のスクリーン25までの距離に応じて、スクリーン25の厚みや、第１抵抗器R1,R1'の抵抗値を適宜調整することにより、信号調整回路によってフォトトランジスタPT,PT'の出力信号を効果的に増幅できる。 In addition, the thickness of the screen 25 and the resistance values of the first resistors R1 and R1 ′ are appropriately adjusted according to the illuminance of the light source 10, the illuminance of the background light, or the distance from the light source 10 to the screen 25 of the light receiver 20. By doing so, the output signals of the phototransistors PT and PT ′ can be effectively amplified by the signal adjustment circuit.
このように構成した受光器20でスクリーン25上に生じた光点を検出する場合には、解析装置27において、第１～４受光素子21,22,23,24から出力された信号の出力電圧の大きさを特定し、特定された出力信号の大きさから図２の出力特性曲線に基づいて、各受光素子21,22,23,24から光点までの距離を特定し、その距離を半径とする仮想円を各受光素子21,22,23,24において描画して、４つの仮想円の交点の位置として理論的には光点の位置を特定することができる。 When a light spot generated on the screen 25 is detected by the light receiver 20 configured as described above, an output voltage of a signal output from the first to fourth light receiving elements 21, 22, 23, 24 is analyzed by the analyzing device 27. 2 is specified, and the distance from each light receiving element 21, 22, 23, 24 to the light spot is specified based on the output characteristic curve of FIG. Is drawn in each of the light receiving elements 21, 22, 23, and 24, and the position of the light spot can theoretically be specified as the position of the intersection of the four virtual circles.
ただし、実際には、各種の誤差の影響によって４つの仮想円が一点で交わることはなく、特に、光源の照度が変動する場合には、交点の位置は変動していないにもかかわらず、各受光素子21,22,23,24では信号の出力電圧が変動することにより、あたかも光点の位置が変動していると認識されるおそれがある。 However, in reality, the four virtual circles do not intersect at a single point due to the effects of various errors, especially when the illuminance of the light source fluctuates, In the light receiving elements 21, 22, 23, and 24, the output voltage of the signal fluctuates, so that it may be recognized that the position of the light spot fluctuates.
このように、光源の照度が変動する場合には、各受光素子21,22,23,24から出力される信号の出力電圧は、ほぼ同等の変化率が乗じられた状態となっているので、各受光素子21,22,23,24の出力電圧に変化率ｋを乗じ、変化率ｋの値を変動させながら４つの仮想円が一点で交わる変化率ｋを特定して、光点の位置を特定することができる。 Thus, when the illuminance of the light source fluctuates, the output voltage of the signal output from each of the light receiving elements 21, 22, 23, 24 is in a state multiplied by a substantially equivalent rate of change, Multiply the output voltage of each light receiving element 21, 22, 23, 24 by the rate of change k, and specify the rate of change k where the four virtual circles intersect at one point while changing the value of the rate of change k, and determine the position of the light spot Can be identified.
なお、この場合でも、４つの仮想円が一点で交わることはほとんどないために、より具体的には、まず、図５に示すように、通常、第１受光素子21を中心とする仮想円s1と第２受光素子22を中心とする仮想円s2との交点である第１交点p1と、第１受光素子21を中心とする仮想円s1と第３受光素子23を中心とする仮想円s3との交点である第２交点p2と、第２受光素子22を中心とする仮想円s2と第４受光素子24を中心とする仮想円s4との交点である第３交点p3と、第３受光素子23を中心とする仮想円s3と第４受光素子24を中心とする仮想円s4との交点である第４交点p4を特定する。 In this case as well, since the four virtual circles hardly intersect at one point, more specifically, first, as shown in FIG. 5, usually, the virtual circle s1 centered on the first light receiving element 21 is used. And a virtual circle s3 centered on the first light-receiving element 23 and a virtual circle s3 centered on the third light-receiving element 23. A third intersection point p3 that is an intersection point of a virtual circle s2 centered on the second light receiving element 22 and a virtual circle s4 centered on the fourth light receiving element 24, and a third light receiving element A fourth intersection point p4 that is an intersection point of the virtual circle s3 centering on 23 and the virtual circle s4 centering on the fourth light receiving element 24 is specified.
次いで、第１受光素子21と第２受光素子22を結ぶ直線と平行に第１交点p1を通る第１直線L1を想定し、第１受光素子21と第３受光素子23を結ぶ直線と平行に第２交点p2を通る第２直線L2を想定し、第２受光素子22と第４受光素子24を結ぶ直線と平行に第３交点p3を通る第３直線L3を想定し、第３受光素子23と第４受光素子24を結ぶ直線と平行に第４交点p4を通る第４直線L4を想定して、第１～４直線L1,L2,L3,L4で囲まれた四角形の面積が最小となる変化率ｋの値を特定する。 Next, assuming a first straight line L1 passing through the first intersection point p1 in parallel with the straight line connecting the first light receiving element 21 and the second light receiving element 22, parallel to the straight line connecting the first light receiving element 21 and the third light receiving element 23. Assuming a second straight line L2 passing through the second intersection point p2, assuming a third straight line L3 passing through the third intersection point p3 parallel to the straight line connecting the second light receiving element 22 and the fourth light receiving element 24, the third light receiving element 23 Assuming a fourth straight line L4 passing through the fourth intersection point p4 in parallel with the straight line connecting the first and fourth light receiving elements 24, the area of the quadrangle surrounded by the first to fourth straight lines L1, L2, L3, L4 is minimized. The value of the change rate k is specified.
そして、特定された変化率ｋの値を用いて第１～４交点p1,p2,p3,p4を特定し、特定された第１～４交点p1,p2,p3,p4の座標の平均値によって特定された座標を交点の位置としている。 Then, the first to fourth intersections p1, p2, p3, p4 are identified using the specified value of the change rate k, and the average value of the coordinates of the identified first to fourth intersections p1, p2, p3, p4 is determined. The specified coordinates are used as the position of the intersection.
なお、各受光素子21,22,23,24から出力される信号の出力電圧が低くて、仮想円の交点が生じない場合には、受光素子間を仮想円の半径比で内分する位置の座標を交点と位置としてもよいし、ｋ＞１である変化率ｋの値をあらかじめ乗じて、必ず交点が存在するようにしてもよい。 If the output voltage of the signal output from each light receiving element 21, 22, 23, 24 is low and no intersection of virtual circles occurs, the position where the light receiving elements are internally divided by the radius ratio of the virtual circle Coordinates may be used as intersections and positions, or intersections may always exist by multiplying in advance by the value of the rate of change k where k> 1.
あるいは、各受光素子21,22,23,24からそれぞれ出力された信号の出力電圧の比を利用して交点の座標を特定してもよい。 Alternatively, the coordinates of the intersection may be specified using the ratio of the output voltages of the signals output from the light receiving elements 21, 22, 23, and 24, respectively.
具体的に説明すると、本実施形態では、ハウジング26に設けた開口部26aは、6cm四方の正方形状としており、この開口部26aの中心を中心として、開口部26aと相似形状の5cm四方の検出エリアを想定しており、図６に示すように、検出エリアに5mm間隔の格子状に計測点ｔを設定して、合計121点の各計測点ｔの出力電圧データを予め計測しておく。各計測点ｔにおける第１受光素子21の出力電圧の値をv1、第２受光素子22の出力電圧の値をv2、第３受光素子23の出力電圧の値をv3、第４受光素子24の出力電圧の値をv4と表すものとする。 Specifically, in this embodiment, the opening 26a provided in the housing 26 has a square shape of 6 cm square, and a 5 cm square detection similar to the opening 26a with the center of the opening 26a as the center. An area is assumed, and as shown in FIG. 6, measurement points t are set in the detection area in a grid of 5 mm intervals, and output voltage data of each measurement point t in total 121 points are measured in advance. The output voltage value of the first light receiving element 21 at each measurement point t is v1, the output voltage value of the second light receiving element 22 is v2, the output voltage value of the third light receiving element 23 is v3, and the fourth light receiving element 24 The output voltage value is represented as v4.
なお、計測点の間隔は5mmに限定するものではなく、任意の間隔としてよく、検出エリアも5cm四方よりも大きくしてもよい。また、第１～４受光素子21,22,23,24は、開口部26aの中心を中心として、開口部26aと相似形状の7cm四方の正方形の頂点部分に配置している。 The interval between the measurement points is not limited to 5 mm, and may be an arbitrary interval, and the detection area may be larger than 5 cm square. The first to fourth light receiving elements 21, 22, 23, and 24 are arranged at the apexes of a 7 cm square having a shape similar to the opening 26a with the center of the opening 26a as the center.
そして、各受光素子21,22,23,24の出力電圧の値v1,v2,v3,v4から、以下の式によって出力電圧の比であるリファレンスデータrv1,rv2,rv3,rv4を特定する。
　　rv1＝v1/(v1＋v2＋v3＋v4)、
　　rv2＝v2/(v1＋v2＋v3＋v4)、
　　rv3＝v3/(v1＋v2＋v3＋v4)、
　　rv4＝v4/(v1＋v2＋v3＋v4)。 Then, reference data rv1, rv2, rv3, rv4, which are ratios of output voltages, are specified from the output voltage values v1, v2, v3, v4 of the respective light receiving elements 21, 22, 23, 24 by the following expression.
rv1 = v1 / (v1 + v2 + v3 + v4),
rv2 = v2 / (v1 + v2 + v3 + v4),
rv3 = v3 / (v1 + v2 + v3 + v4),
rv4 = v4 / (v1 + v2 + v3 + v4).
このリファレンスデータrv1,rv2,rv3,rv4をデータベースとして解析装置27内にあらかじめ設けておき、光点の位置の検出に際しては、第１～４受光素子21,22,23,24から出力された信号の出力電圧の値を用いて、上記の式と同様の演算を行って出力電圧の比のデータrv1',rv2',rv3',rv4'を特定する。 The reference data rv1, rv2, rv3, rv4 are provided in the analysis device 27 in advance as a database, and the signals output from the first to fourth light receiving elements 21, 22, 23, 24 are used when detecting the position of the light spot. The output voltage ratio data rv1 ′, rv2 ′, rv3 ′, and rv4 ′ are specified by performing the same calculation as the above-described expression using the output voltage value.
そして、ＳＡＤ(Sum of Absolute Diffelence)相関Ｄの値を
　　Ｄ＝｜rv1－rv1'｜＋｜rv2－rv2'｜＋｜rv3－rv3'｜＋｜rv4－rv4'｜
として最小のＤの値となる計測点ｔを特定し、特定された計測点ｔを光点の位置としている。 Then, the value of the SAD (Sum of Absolute Diffelence) correlation D is expressed as D = | rv1-rv1 ′ | + | rv2-rv2 ′ | + | rv3-rv3 ′ | + | rv4-rv4 ′ |
The measurement point t having the minimum value of D is specified as follows, and the specified measurement point t is set as the position of the light spot.
なお、この場合には、光点の位置の分解能が5mmとなって、比較的粗いため、本実施形態では、光点に対する出力電圧の比のデータと、データベースのリファレンスデータrv1,rv2,rv3,rv4とを比較して、光点の位置を取り囲む４つの計測点をあらかじめ特定し、この４つの計測点で構成される領域において双線形補間を利用して0.5mm間隔の格子点のリファレンスデータを生成し、このリファレンスデータに対してＳＡＤ相関Ｄの値を最小とする格子点を光点の位置としている。したがって、光点の位置の分解能を0.5mmとすることができる。 In this case, since the resolution of the position of the light spot is 5 mm and is relatively coarse, in this embodiment, the ratio of the output voltage to the light spot and the reference data rv1, rv2, rv3, Compared with rv4, four measurement points surrounding the position of the light spot are specified in advance, and the reference data of the grid points at intervals of 0.5 mm is obtained using bilinear interpolation in the area composed of these four measurement points. The lattice point that is generated and minimizes the value of the SAD correlation D with respect to this reference data is set as the position of the light spot. Therefore, the resolution of the position of the light spot can be set to 0.5 mm.
このように、各受光素子21,22,23,24からそれぞれ出力された信号の出力電圧の比を利用して光点の座標を特定する方が、先に説明した仮想円を用いて光点の座標を特定するよりも精度がよかった。 As described above, it is better to specify the coordinates of the light spot using the ratio of the output voltages of the signals output from the light receiving elements 21, 22, 23, 24, respectively, using the virtual circle described above. The accuracy was better than specifying the coordinates.
すなわち、仮想円を用いて光点の座標を特定する場合には、ハウジング26に装着された状態における各受光素子21,22,23,24の指向特性の影響が出力電圧の値に影響を及ぼすおそれがあるが、各受光素子21,22,23,24からそれぞれ出力された信号の出力電圧の比を利用した場合には、各受光素子21,22,23,24の指向特性の影響が互いに減殺されて、精度が向上したものと考えられる。 That is, when the coordinates of the light spot are specified using a virtual circle, the influence of the directivity of each light receiving element 21, 22, 23, 24 in the state where it is mounted on the housing 26 affects the value of the output voltage. However, if the ratio of the output voltages of the signals output from the light receiving elements 21, 22, 23, and 24 is used, the influence of the directivity characteristics of the light receiving elements 21, 22, 23, and 24 It is thought that the accuracy was improved after being killed.
本実施形態の受光器20は、光源10と正対している必要はなく、スクリーン25に対してスポット光が90°以外の所定の角度から入射してもよく、またスポット光によってスクリーン25に光点さえ生じさせることができれば、受光器20は光源10からどんなに離れていてもよい。 The light receiver 20 of the present embodiment does not need to face the light source 10, and the spot light may be incident on the screen 25 from a predetermined angle other than 90 °. The receiver 20 can be any distance from the light source 10 as long as a point can be generated.
上述したように、スポット光はパルス状としているが、パルス状に照射するスポット光をパルス変調することによりデューティ比を調整する調整手段を光源10に設けて、単なるパルス状とするだけでなく、スポット光を照射するオン状態の時間間隔、またはスポット光を照射しないオフ状態の時間間隔を適宜調整してもよい。 As described above, the spot light is pulsed, but the light source 10 is provided with adjusting means for adjusting the duty ratio by pulse-modulating the spot light to be irradiated in a pulse shape, not only in a pulse shape, You may adjust suitably the time interval of the ON state which irradiates spot light, or the time interval of the OFF state which does not irradiate spot light.
特に、例えば、スポット光を照射するオン状態の時間間隔が所定の時間より長い第１の照射パターンと、所定の時間よりも短い第２の照射パターンの２種類のスポット光を照射可能として、第１の照射パターンと第２の照射パターンとを適宜組み合わせてスポット光を照射する一方、受光器20の解析装置27が、各受光素子21,22,23,24からそれぞれ出力された信号の出力電圧から第１の照射パターンと第２の照射パターンとを識別することにより、シリアル通信によってバイナリデータを送受信できる。 In particular, for example, it is possible to irradiate two types of spot light, that is, a first irradiation pattern in which the time interval of on-state irradiation with the spot light is longer than a predetermined time and a second irradiation pattern shorter than the predetermined time. While the spot light is irradiated by appropriately combining the first irradiation pattern and the second irradiation pattern, the analyzer 27 of the light receiver 20 outputs the output voltage of the signal output from each of the light receiving elements 21, 22, 23, and 24, respectively. Thus, binary data can be transmitted and received by serial communication by identifying the first irradiation pattern and the second irradiation pattern.
すなわち、受光器20の解析装置27では、第１の照射パターンを「１」のデータ、第２の照射パターンを「０」のデータとして識別する、またはその逆として識別するものである。なお、バイナリデータの識別は、デューティ比の差のみで行うのではなく、スポット光の照度を調節して、照度の変動を利用してシリアル通信を行ってもよい。 That is, the analysis device 27 of the light receiver 20 identifies the first irradiation pattern as “1” data and the second irradiation pattern as “0” data, or vice versa. Note that binary data identification is not performed based only on the difference in duty ratio, but serial communication may be performed using the variation in illuminance by adjusting the illuminance of the spot light.
スポット光のデューティ比を調整する調整手段としては、所定のタイミング信号を生成するために一般的に用いられているタイミング生成回路等を用いることができ、別途入力されたデータに基づいてタイミング生成回路等を用いて制御信号を生成し、この制御信号に基づいて光源10から所望のスポット光を照射可能としている。 As the adjusting means for adjusting the duty ratio of the spot light, a timing generation circuit or the like generally used for generating a predetermined timing signal can be used, and the timing generation circuit based on separately input data And the like, and a desired spot light can be emitted from the light source 10 based on the control signal.
受光器20の他の実施形態として、スクリーン25が張設された箱状のハウジング26の内部に、図７に模式的に示すように、ハウジング内を所定の明るさとする照光器28を設けてもよい。 As another embodiment of the light receiver 20, as shown schematically in FIG. 7, an illuminator 28 having a predetermined brightness is provided inside a box-shaped housing 26 on which a screen 25 is stretched. Also good.
本実施形態では、照光器28は、第１～４発光ダイオード28-1,28-2,28-3,28-4の４つの発光ダイオードで構成しており、第１～４発光ダイオード28-1,28-2,28-3,28-4はハウジング26の中央部分に設けるとともに、第１発光ダイオード28-1を第１受光素子21に向けて配設し、第２発光ダイオード28-2を第２受光素子22に向けて配設し、第３発光ダイオード28-3を第３受光素子23に向けて配設し、第４発光ダイオード28-4を第４受光素子24に向けて配設している。 In the present embodiment, the illuminator 28 includes four light emitting diodes of first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4, and the first to fourth light emitting diodes 28- 1, 28-2, 28-3, and 28-4 are provided in the central portion of the housing 26, and the first light emitting diode 28-1 is disposed toward the first light receiving element 21, and the second light emitting diode 28-2 is provided. Is disposed toward the second light receiving element 22, the third light emitting diode 28-3 is disposed toward the third light receiving element 23, and the fourth light emitting diode 28-4 is disposed toward the fourth light receiving element 24. Has been established.
特に、第１～４発光ダイオード28-1,28-2,28-3,28-4は、第１～４受光素子21,22,23,24よりもスクリーン25寄りに配設して、第１～４受光素子21,22,23,24に対して効果的に照光可能としている。 In particular, the first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4 are disposed closer to the screen 25 than the first to fourth light receiving elements 21, 22, 23, 24. The 1 to 4 light receiving elements 21, 22, 23, 24 can be effectively illuminated.
このように、ハウジング26の内部に照光器28を設けて、ハウジング内を所定の明るさとすることにより、夜間やトンネル内などのような比較的暗い環境下に受光器20を設置して使用する場合でも、光点の位置検出に関して十分な精度を維持することができる。 Thus, by providing the illuminator 28 inside the housing 26 and setting the inside of the housing to a predetermined brightness, the light receiver 20 is installed and used in a relatively dark environment such as at night or in a tunnel. Even in this case, sufficient accuracy can be maintained with respect to the detection of the position of the light spot.
すなわち、第１～４受光素子21,22,23,24は、一般的に、ある程度以下の照度に対して感度が著しく劣り、照度の変化に対する出力電圧の変化量の線形性が悪いため、光点の位置の検出精度が低下するおそれがあったが、照光器28により第１～４受光素子21,22,23,24を照光しておくことにより、照度の変化に対する出力電圧の変化量の線形性が良好な領域を利用して光点の位置を検出することができ、検出精度を向上させることができる。 That is, the first to fourth light receiving elements 21, 22, 23, and 24 generally have extremely low sensitivity to illuminance below a certain level, and the linearity of the amount of change in output voltage with respect to illuminance change is poor. Although the detection accuracy of the position of the point may be lowered, by illuminating the first to fourth light receiving elements 21, 22, 23, and 24 with the illuminator 28, the amount of change in the output voltage with respect to the change in illuminance can be reduced. The position of the light spot can be detected using a region with good linearity, and the detection accuracy can be improved.
本実施形態では、照光器28には、第１～４発光ダイオード28-1,28-2,28-3,28-4を用いているが、第１～４受光素子21,22,23,24の応答特性を改善できるのであれば、照光器28は何であってもよい。 In the present embodiment, the illuminator 28 uses the first to fourth light emitting diodes 28-1, 28-2, 28-3, 28-4, but the first to fourth light receiving elements 21, 22, 23, The illuminator 28 can be anything as long as the response characteristics of 24 can be improved.
上述した実施形態では、矩形体状としたハウジング26に第１～４受光素子21,22,23,24を設けるとともに、矩形状の検出領域を設けているが、この形態に限定されるものではなく、図８に示すように、一方向に伸びた矩形体状のハウジング40に細幅の帯状にスクリーン41を設け、ハウジング40の長手方向の両端に第１の受光素子42と第２の受光素子43とを設けて、ライン状の検出領域を有するようにしてもよい。 In the embodiment described above, the first to fourth light receiving elements 21, 22, 23, and 24 are provided in the rectangular housing 26, and the rectangular detection region is provided. However, the present invention is not limited to this embodiment. Instead, as shown in FIG. 8, a rectangular-shaped housing 40 extending in one direction is provided with a screen 41 in the form of a narrow band, and a first light receiving element 42 and a second light receiving element are disposed at both ends of the housing 40 in the longitudinal direction. The element 43 may be provided to have a linear detection region.
あるいは、図９に示すように、三角柱状のハウジング50の一方の面に三角形状のスクリーン51を設け、他方の面の３つの角部分に第１の受光素子52と、第２の受光素子53と、第３の受光素子54とを設けて、三角状の検出領域を有するようにしてもよいし、図１０に示すように、六角柱状のハウジング60の一方の面に六角形状のスクリーン61を設け、他方の面の６つの角部分に第１の受光素子62と、第２の受光素子63と、第３の受光素子64と、第４の受光素子65と、第５の受光素子66と、第６の受光素子67とを設けて、六角状の検出領域を有するようにしてもよい。 Alternatively, as shown in FIG. 9, a triangular screen 51 is provided on one surface of a triangular prism-shaped housing 50, and a first light receiving element 52 and a second light receiving element 53 are provided at three corners of the other surface. And a third light receiving element 54 may be provided so as to have a triangular detection region, or a hexagonal screen 61 is provided on one surface of a hexagonal columnar housing 60 as shown in FIG. The first light receiving element 62, the second light receiving element 63, the third light receiving element 64, the fourth light receiving element 65, and the fifth light receiving element 66 are provided at the six corners of the other surface. A sixth light receiving element 67 may be provided to have a hexagonal detection region.
さらには、図１１に示すように、円柱状としたハウジング70の周面部分に円周面状のスクリーン71を設け、円柱状のハウジング70の一方の端面部分に第１の受光素子72を設けるとともに、円柱状のハウジング70の他方の端面部分に第２の受光素子73を設け、特に、第１の受光素子72と第２の受光素子73とは互いに対向させて設けて、円周面状の検出領域を有するようにしてもよい。 Further, as shown in FIG. 11, a circumferential screen 71 is provided on the peripheral surface portion of the cylindrical housing 70, and a first light receiving element 72 is provided on one end surface portion of the cylindrical housing 70. At the same time, a second light receiving element 73 is provided on the other end surface portion of the cylindrical housing 70, and in particular, the first light receiving element 72 and the second light receiving element 73 are provided to face each other to form a circumferential surface. You may make it have this detection area | region.
あるいは、図１２に示すように、頂部に開口部を有する半球状のハウジング80の頂部に球面状のスクリーン81を設け、半球状のハウジング80の中心部に、第１の受光素子82と、第２の受光素子83と、第３の受光素子84とを互いの中心軸を直交させながら配置して、球面状の検出領域を有するようにしてもよい。 Alternatively, as shown in FIG. 12, a spherical screen 81 is provided at the top of a hemispherical housing 80 having an opening at the top, and a first light receiving element 82 and a first light receiving element 82 are provided at the center of the hemispherical housing 80. The two light receiving elements 83 and the third light receiving element 84 may be arranged with their center axes orthogonal to each other so as to have a spherical detection region.
このように、光点の検出領域は、必要に応じて適宜の形状とすることができ、検出領域の形状に合わせて受光素子を適宜配置してよい。 As described above, the light spot detection region can be formed in an appropriate shape as necessary, and the light receiving elements may be appropriately arranged in accordance with the shape of the detection region.
このように構成した光点位置検出装置は、図１３に概略的に示すように、橋梁などの構造物の変位計測や、崖などの法面の変形検出等に用いることができる。 The light spot position detection apparatus configured in this way can be used for displacement measurement of structures such as bridges, deformation detection of slopes such as cliffs, etc., as schematically shown in FIG.
特に、本実施形態の光点位置検出装置では、図１３に示すように、第１の橋脚91と第２の橋脚92との間に架設した橋梁部90の所定位置に第１の光源93aを設けるとともに、第１の光源93aから所定の距離だけ離隔した位置に第１の受光器93bを設け、この第１の受光器93bの近傍に第２の光源94aを設けるとともに、第２の光源94aから所定の距離だけ離隔した位置に第２の受光器94bを設け、この第２の受光器94bの近傍に第３の光源95aを設けるとともに、第３の光源95aから所定の距離だけ離隔した位置に第３の受光器95bを設けている。 In particular, in the light spot position detecting device of the present embodiment, as shown in FIG. 13, the first light source 93a is provided at a predetermined position of the bridge portion 90 laid between the first pier 91 and the second pier 92. The first light receiver 93b is provided at a position separated by a predetermined distance from the first light source 93a, the second light source 94a is provided in the vicinity of the first light receiver 93b, and the second light source 94a is provided. The second light receiver 94b is provided at a position separated from the third light source 94b by a predetermined distance, and a third light source 95a is provided in the vicinity of the second light receiver 94b, and the third light source 95a is spaced from the third light source 95a by a predetermined distance. Is provided with a third light receiver 95b.
さらに、第１の光源93aと、第２の光源94aと、第３の光源95aにはそれぞれ照射するスポット光をパルス変調することによりデューティ比を調整する調整手段を設けており、しかも、第１の受光器93bと、第２の受光器94bと、第３の受光器95bには、各光源93a,94a,95aから照射されてきたパルス状のスポット光からバイナリデータを読み出す解析部を具備させている。 Further, the first light source 93a, the second light source 94a, and the third light source 95a are each provided with adjusting means for adjusting the duty ratio by pulse-modulating the spot light to be irradiated. The light receiver 93b, the second light receiver 94b, and the third light receiver 95b are provided with an analysis unit that reads binary data from the pulsed spot light emitted from the light sources 93a, 94a, and 95a. ing.
そして、第１の受光器93bと第２の光源94aとは第１の接続配線96で接続して、第１の受光器93bから出力された信号を第２の受光器94bへ入力して、第１の受光器93bの出力信号を第２の受光器94bに送信可能としている。 And the 1st light receiver 93b and the 2nd light source 94a are connected by the 1st connection wiring 96, the signal output from the 1st light receiver 93b is input into the 2nd light receiver 94b, The output signal of the first light receiver 93b can be transmitted to the second light receiver 94b.
さらに、第２の受光器94bと第３の光源95aとは第２の接続配線97で接続して、第２の受光器94bから出力された信号を第３の受光器95bへ入力して、第１の受光器93bの出力信号と、第２の受光器94bの出力信号を第３の受光器95bに送信して、第３の受光器95bから各受光器93b,94b,95bの出力信号を得ることができるようにしている。 Further, the second light receiver 94b and the third light source 95a are connected by the second connection wiring 97, and the signal output from the second light receiver 94b is input to the third light receiver 95b. The output signal of the first light receiver 93b and the output signal of the second light receiver 94b are transmitted to the third light receiver 95b, and the output signal of each of the light receivers 93b, 94b, 95b is transmitted from the third light receiver 95b. So that you can get.
したがって、各受光器93b,94b,95bにそれぞれ別途の出力用の信号線を設ける必要がなく、簡潔な配線の光点位置検出装置として、橋梁などの大規模な構造物に対して安価に設置できる。 Therefore, it is not necessary to provide a separate output signal line for each of the light receivers 93b, 94b, 95b, and as a light spot position detection device with simple wiring, it can be installed inexpensively on large structures such as bridges. it can.
本発明の光点位置検出装置では、上述したように、構造物における変動検出に用いるだけでなく、レーザ光を照射可能としたモデルガンを利用した射的ゲームに用いることもでき、あるいは、特許文献２に記載されているようなレーザ光を利用して移動物体を誘導する際の受光部として用いることができる。 As described above, the light spot position detection device of the present invention can be used not only for detecting changes in a structure but also for a shooting game using a model gun capable of irradiating laser light, or a patent. It can be used as a light receiving unit when guiding a moving object using laser light as described in Document 2.
　Ｌ　スポット光
　10　光源
　21　第１受光素子
　22　第２受光素子
　23　第３受光素子
　24　第４受光素子
　25　スクリーン
　26　ハウジング
　26a 開口部
　26b 外縁部
　27　解析装置
　Ｓ　中心軸 L Spot light 10 Light source 21 1st light receiving element 22 2nd light receiving element 23 3rd light receiving element 24 4th light receiving element 25 Screen 26 Housing 26a Opening part 26b Outer edge part 27 Analyzing device S Central axis

Claims (5)

  1. 　スポット光を照射する光源と、
    　この光源から照射されたスポット光をスクリーンで受けるとともにスクリーン上に現れた前記スポット光による光点の位置を検出する検出手段を備えた受光器と
    を有する光点位置検出装置であって、
    　前記スクリーンは拡散透過性材で構成し、
    　前記検出手段は、前記スクリーンの裏側に設けた複数の受光素子と、これらの各受光素子からの出力信号を解析する解析部とを備えた光点位置検出装置。     A light source that emits spot light;
    A light spot position detecting device including a light receiving device that receives spot light emitted from the light source on a screen and includes a detecting unit that detects a position of a light spot by the spot light appearing on the screen,
    The screen is made of a diffuse permeable material,
    The light spot position detecting device includes a plurality of light receiving elements provided on the back side of the screen and an analysis unit that analyzes an output signal from each of the light receiving elements.
  2. 　前記光源は、前記スポット光をパルス状として照射する請求項１記載の光点位置検出装置。 The light spot position detecting device according to claim 1, wherein the light source irradiates the spot light as a pulse.
  3. 　前記光源は、パルス状の前記スポット光のデューティ比を調整して所定の信号を送信する制御手段を備え、
    　前記検出手段の前記解析部は、前記スポット光から前記信号を読み出すことにより前記信号を伝送する請求項２記載の光点位置検出装置。     The light source includes control means for adjusting a duty ratio of the pulsed spot light and transmitting a predetermined signal,
    The light spot position detection device according to claim 2, wherein the analysis unit of the detection unit transmits the signal by reading the signal from the spot light.
  4. 　前記受光素子は、入光角度が０度となる中心軸を前記スクリーンと直交させて設けるとともに、前記中心軸上に遮蔽体を設けている請求項１～３のいずれか１項に記載の光点位置検出装置。 The light according to any one of claims 1 to 3, wherein the light receiving element is provided with a central axis at a light incident angle of 0 degrees orthogonal to the screen and a shielding body provided on the central axis. Point position detection device.
  5. 　前記受光素子は、前記スクリーンが張設された箱状のハウジング内に設け、このハウジング内に、前記ハウジング内を所定の明るさとする照光器を設けている請求項１～４のいずれか１項に記載の光点位置検出装置。

          5. The light receiving element according to claim 1, wherein the light receiving element is provided in a box-shaped housing on which the screen is stretched, and an illuminator for providing a predetermined brightness in the housing is provided in the housing. The light spot position detection apparatus described in 1.

PCT/JP2010/058009 2009-06-15 2010-05-12 Light point position detection device WO2010146950A1 (en)

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WO2022172608A1 (en) * 2021-02-12 2022-08-18 パナソニックＩｐマネジメント株式会社 Optical device

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JPS49135495A (en) * 1973-05-02 1974-12-26
JPS59214704A (en) * 1983-05-21 1984-12-04 Mc Kk Automatic device using laser
JPH0618217A (en) * 1992-06-29 1994-01-25 Akitsugu Fujieda Wide range position detector
JP2001514736A (en) * 1996-01-23 2001-09-11 アドバンスト・オプティカル・テクノロジーズ・リミテッド・ライアビリティ・カンパニー Quadrant detector
JP2008541108A (en) * 2005-05-18 2008-11-20 ライカ ジオシステムズ アクチェンゲゼルシャフト Method and system for determining the position of a receiving unit

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JPS61233303A (en) * 1985-04-09 1986-10-17 Nissan Motor Co Ltd Inspecting system for point to be inspected

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JPS49135495A (en) * 1973-05-02 1974-12-26
JPS59214704A (en) * 1983-05-21 1984-12-04 Mc Kk Automatic device using laser
JPH0618217A (en) * 1992-06-29 1994-01-25 Akitsugu Fujieda Wide range position detector
JP2001514736A (en) * 1996-01-23 2001-09-11 アドバンスト・オプティカル・テクノロジーズ・リミテッド・ライアビリティ・カンパニー Quadrant detector
JP2008541108A (en) * 2005-05-18 2008-11-20 ライカ ジオシステムズ アクチェンゲゼルシャフト Method and system for determining the position of a receiving unit

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022172608A1 (en) * 2021-02-12 2022-08-18 パナソニックＩｐマネジメント株式会社 Optical device

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JPWO2010146950A1 (en) 2012-12-06

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