JP2018010376A - Optical position detection apparatus and optical position detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical position detection apparatus in simple configuration with less components, configured to improve measurement accuracy.SOLUTION: An optical position detection apparatus 100 for detecting a position of a pointing object in a predetermined area includes: an optical scanning unit 110 arranged to face the predetermined area, having a polygon mirror 111, and performing angular-scanning with a beam in a scanning plane parallel with the predetermined area; first and second light-emitting units 120, 130 for emitting beams to two reflection planes 111a, 111b of the polygon mirror 111 each having an angle, respectively; a first light-receiving unit 140 which receives a first beam emitted from the first light-emitting unit 120 and reflected by the reflection plane 111a of the polygon mirror 111; and a second light-receiving unit 150 which receives a second beam emitted from the second light-emitting unit 130 and reflected by the reflection plane 111b of the polygon mirror 111. The optical scanning unit 110 scans the pointing object M by rotating the polygon mirror 111.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical position detection apparatus and an optical position detection method.

In a personal computer, a touch method is often employed in which input is performed by bringing a display location of information displayed on the screen of a display device into contact with a person's finger or a pen-like indicator.
As a method for detecting such a contact position on the screen, a light retroreflector is disposed on the frame portion of the display screen and irradiated from a light emitting unit disposed so as to face the display screen and the light retroreflector. There is a technique for detecting a position by scanning an angle on a screen with a laser beam, detecting light returning from a light retroreflector by a light receiving unit, and calculating an angle (see Patent Documents 1 and 2).

  When a finger or an indicator is placed on the screen, the light beam for angle scanning is reflected by the finger or the indicator at the placement position, and light returning to the light retroreflector is blocked, so that the returning light The amount of light changes. The angle at which the finger or the pointing object exists is calculated from the timing of this change, and the position coordinates can be detected from the calculated angle in the manner of triangulation.

JP 2000-148397 A JP 2000-242406 A

In the position detection methods described in Patent Documents 1 and 2, the difference in the amount of light between the laser beam shielded and scattered by the finger or the indicator and the reflected light reflected by the light retroreflector returns to the light receiving unit. Detection and position coordinates are calculated by the light receiving unit.
Triangulation using this method requires at least a pair of light emitting units, a pair of light receiving units, a pair of deflecting units, and a pair of scanning units provided at different positions. And sometimes complicated.

  Furthermore, in order to reliably triangulate a plurality of indicators by the position detection methods described in Patent Documents 1 and 2, a light emitting unit, a light receiving unit, a scanning unit, and a deflection unit that are more than the number of the indicators are integrated. Since each position detection unit can be a disturbance depending on their arrangement, it is necessary to sequentially perform scanning by each position detection unit in order to perform reliable detection. There was a risk of requiring.

  Therefore, the present invention solves the problems of the prior art as described above. That is, the object of the present invention is to improve the measurement accuracy and reduce the number of components even with a simpler configuration. A position detection apparatus and an optical position detection method are provided.

The invention according to claim 1 is an optical position detection device that detects the position of an indicator in a predetermined area, is arranged so as to face the predetermined area, has a polygon mirror, and is parallel to the predetermined area. An optical scanning unit that angularly scans light in the plane is provided.
In addition, the first light emitting unit and the second light emitting unit that irradiate light to each of the two reflecting surfaces having an angle with each other of the polygon mirror, and the first light emitting unit emit light and are reflected by one reflecting surface of the polygon mirror. A first light-receiving unit that receives the first beam; and a second light-receiving unit that receives the second beam emitted from the second light-emitting unit and reflected by the other reflecting surface of the polygon mirror.
The optical scanning unit solves the above-described problem by rotating the polygon mirror and scanning the indicator.

  In the invention according to claim 2, in addition to the optical position detection device according to claim 1, the first light receiving portion and the second light receiving portion are arranged so as to overlap the outer edge facing the predetermined region. The above-described problems are further solved by receiving the first beam and the second beam incident on the light guide.

  The invention according to claim 3 includes, in addition to the optical position detection device according to claim 1, a retroreflector disposed on the outer edge facing the predetermined region, and the retroreflector to the optical scanning unit. A deflection unit that deflects the reflected light, and the first light receiving unit and the second light receiving unit receive the first beam and the second beam deflected by the deflection unit, respectively, to further solve the above-described problem. Is.

  According to the fourth aspect of the present invention, in addition to the optical position detection device according to any one of the first to third aspects, the first light emitting unit receives the first beam on the first light receiving unit. Irradiate light to the first reflection position on one reflection surface so that the second light-emitting portion receives the second beam on the second reflection portion so that the second light-receiving portion receives the second beam. The above-described problems are further solved by irradiating with.

  In the invention according to claim 5, in addition to the optical position detection device according to claim 4, the first reflection position and the second reflection position are arranged at different positions in the direction perpendicular to the scanning plane. The first light receiving part and the second light receiving part are arranged according to the first reflection position and the second reflection position, thereby further solving the above-described problem.

  The invention according to claim 6 is described above by the optical position detection method in which the plurality of optical position detection devices according to any one of claims 1 to 5 are respectively arranged at different positions facing a predetermined region. It solves the problem.

  The invention according to claim 7 is an optical position detection method using the optical position detection device according to any one of claims 1 to 5, wherein the first light emitting part and the second light emitting part are: The first beam and the second beam are emitted simultaneously, the optical scanning unit rotates the polygon mirror to scan the indicator, and the first light receiving unit and the second light receiving unit calculate the light amounts of the first beam and the second beam. The above-described problem is solved by calculating the position of the indicator based on the temporal change of the light amounts of the received first beam and second beam.

  The optical position detection apparatus and the optical position detection method for detecting the position of an indicator within a predetermined area of the present invention not only improve the measurement accuracy and reduce the number of parts, but also have the following specific effects. Play.

  According to the optical position detection device of the invention of claim 1, the optical scanning unit is arranged so as to face the predetermined area, has a polygon mirror, and angularly scans light within a scanning plane parallel to the predetermined area. The first light emitting unit and the second light emitting unit that irradiate light to each of the two reflecting surfaces having an angle with each other of the polygon mirror, and the first light emitting unit emit light and are reflected by one reflecting surface of the polygon mirror A first light-receiving unit that receives the first beam; and a second light-receiving unit that receives the second beam emitted from the second light-emitting unit and reflected by the other reflecting surface of the polygon mirror. Rotating and scanning the indicator, angle scanning is performed by one polygon mirror and two laser beams synchronized by this one polygon mirror, so that a simple configuration with a small number of parts can be achieved. so That.

  In addition, according to this optical position detection device, the two laser beams are provided with their respective light receiving units, and the indicator is scanned, so that the indicator as in the technique disclosed in Patent Documents 1 and 2 is used. The coordinates can be calculated using the change in the amount of light, which is a measurement value of the directly irradiated laser beam, instead of the scattered light from Enables detection and improves measurement accuracy.

  Furthermore, according to this optical position detection apparatus, it is possible to irradiate two laser beams at the same time by measuring the change in the amount of light that is not easily affected by disturbance as described above, thereby shortening the measurement time. Can do.

  Further, by simultaneously irradiating two laser beams from a distant place, the trajectory of the two beams can also be widened. Therefore, the area of the blind spot behind the indicator caused by the light being blocked is determined as one of the prior arts. This can be reduced as compared with scanning by one light emitting unit, light receiving unit, and scanning unit.

  According to the optical position detection device of the invention of claim 2, in addition to the effect of the invention of claim 1, the first light receiving part and the second light receiving part are overlapped with the outer edge facing the predetermined region. An optical retroreflector as in the technique disclosed in Patent Documents 1 and 2 by receiving a first beam and a second beam incident on the light guide, each having a light guide disposed. Therefore, the number of parts can be reduced.

  According to the optical position detection device of the invention according to claim 3, in addition to the effect produced by the invention according to claim 1, the retroreflector disposed on the outer edge facing the predetermined region, and the retroreflector A deflecting unit that deflects reflected light to the optical scanning unit, and the first light receiving unit and the second light receiving unit receive the first beam and the second beam deflected by the deflecting unit, respectively. Since the prior art know-how and experience values shown in Documents 1 and 2 can be reflected as they are, highly reliable position detection can be performed.

  According to the optical position detection device of the invention of claim 4, in addition to the effect produced by the invention of any one of claims 1 to 3, the first light emitting unit transmits the first beam to the first beam. Light is irradiated to the first reflection position on one reflection surface so that the first light receiving portion receives light, and the second light emitting portion causes the second light receiving portion to receive the second beam on the other reflection surface. By irradiating light to two reflection positions, the reflection position of the mirror is specified so as to prevent two beams from being incident on one photoreceptor, so even when performing simultaneous measurement with two beams, It is possible to perform highly reliable position detection measurement without the two light beams affecting each other.

  According to the optical position detection apparatus of the invention of claim 5, in addition to the effect of the invention of claim 4, the first reflection position and the second reflection position are perpendicular to the scanning plane. The first light receiving part and the second light receiving part are arranged in accordance with the first reflection position and the second reflection position, so that the two beams do not overlap each other. Therefore, even when simultaneous measurement using two beams is performed, it is possible to perform highly reliable position detection measurement without the two light beams affecting each other.

  According to a sixth aspect of the present invention, a plurality of optical position detection devices according to any one of the first to fifth aspects are predetermined by an optical position detection method that is arranged at different positions facing a predetermined region. Even when there are a plurality of indicators in the region, the plurality of position detection devices can scan without blind spots, so that the positions of the plurality of indicators can be detected.

  The invention according to claim 7 is an optical position detection method using the optical position detection device according to any one of claims 1 to 5, wherein the first light emitting part and the second light emitting part are: The first beam and the second beam are emitted at the same time, the optical scanning unit rotates the polygon mirror to scan the indicator, and the first light receiving unit and the second light receiving unit detect the first beam and the second beam. By receiving the amount of light and calculating the position of the indicator based on the temporal change in the amount of light of the received first beam and second beam, the light is irradiated directly from the beam instead of the scattered light from the indicator. In order to measure light, more accurate position detection is possible, and time scanning can be shortened because angle scanning is simultaneously performed by two beams.

The top view which shows the whole position detection apparatus which is 1st Embodiment of this invention. The perspective view explaining the position detection apparatus shown in FIG. The side view explaining the position detection apparatus shown in FIG. The top view explaining the scanning process of the position detection apparatus shown in FIG. The graph explaining the scanning process of the position detection apparatus shown in FIG. The schematic diagram which shows the point of the triangulation for coordinate calculation. The top view which shows the whole position detection apparatus which is 2nd Embodiment of this invention. The top view which shows the arrangement | positioning method of the position detection apparatus which is 3rd Embodiment of this invention. The graph explaining the scanning process of the position detection apparatus shown in FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments according to an optical position detection device and an optical position detection method of the invention will be described with reference to the drawings. In the following description, the configurations denoted by the same reference numerals in different drawings are the same, and the description thereof may be omitted.

  The optical position detection device for detecting the position of an indicator within a predetermined area according to the present invention is arranged so as to face the predetermined area, has a polygon mirror, and angle the light within a scanning plane parallel to the predetermined area. An optical scanning unit that scans, a first light emitting unit and a second light emitting unit that irradiate light to each of two reflecting surfaces having an angle with respect to the polygon mirror, and the first light emitting unit emit light, and one reflection of the polygon mirror A first light-receiving unit that receives the first beam reflected by the surface, and a second light-receiving unit that emits light from the second light-emitting unit and receives the second beam reflected by the other reflecting surface of the polygon mirror. As long as the scanning unit scans the indicator by rotating the polygon mirror, any specific mode may be used.

[First Embodiment]
[Description of overall configuration]
Hereinafter, the position detection apparatus 100 which is 1st Embodiment of this invention is demonstrated based on FIGS. 1-6.
Here, FIG. 1 is a plan view showing the entire position detection apparatus according to the first embodiment of the present invention, and FIG. 2 is a perspective view of the position detection apparatus shown in FIG. 1 is a side view of the position detection device shown in FIG. 1 as viewed from the direction of arrow B in FIG. 1, FIG. 4 is a plan view illustrating a scanning process of the position detection device shown in FIG. 1, and FIG. 6 is a graph for explaining the scanning process of the position detecting device shown in FIG. 6, and FIG. 6 is a schematic diagram showing the point of triangulation for coordinate calculation.

  Referring to FIG. 1, the indicator M is arranged in the predetermined area S. The predetermined area S corresponds to a display screen of a CRT, a flat display panel (LCD, EL, etc.) or a plasma display (PDP), which is a display device of an electronic device such as a personal computer, as well as a simple board-shaped surface.

In FIG. 1, the predetermined region S is rectangular, but is not limited to this shape, and may be circular or polygonal. The direction in which the predetermined area S is installed is not particularly limited, and the predetermined area S may be horizontally placed, vertically placed vertically, or placed obliquely.
Further, the surface on which the indicator M in the predetermined area S is arranged does not have to be a complete horizontal plane, and is a first parallel to the predetermined area S shown in FIG. 3 which is a plan view of FIG. Irregularities in the range where the scanning surface F1 and the second scanning surface F2 can scan the indicator M are allowed.

  The pointing object M corresponds to a human finger or a pen-shaped pointing object, but is not limited thereto. For example, the pointing object M is also applicable to an object (such as a person or a car) placed on a flat wide predetermined area S. The indicator M can be applied as long as it can block the irradiated scanning light.

  An example of the position detection apparatus 100 according to the present embodiment is for detecting the position of an indicator M in a predetermined area S, and includes an optical scanning unit 110, a first light emitting unit 120, and a second light emitting unit. 130, a first light receiving unit 140, and a second light receiving unit 150.

  The optical scanning unit 110 includes a polygon mirror 111 disposed at a rectangular corner so as to face the predetermined region S. The polygon mirror 111 is a rotating polygon mirror mounted on a high-precision digital copying machine, a laser printer, or the like, and each surface of the polyhedron is a mirror and is rotated at high speed by a motor mounted in the optical scanning unit 110. Thus, the laser is angularly scanned. That is, assuming that the rotational speed is constant, the laser scanning speed and the laser scanning angle can be determined by the number of mirror surfaces. In this embodiment, an example in which each side surface of a hexagonal column is a mirror is shown, but a polygonal column such as a quadrangular column or an octagonal column may be used.

  The light emitted from the first light emitting unit 120 and the second light emitting unit 130 is reflected by different first reflecting surface 111a and second reflecting surface 111b, which are mirrors disposed on each side surface of the polygon mirror 111 and having an angle with each other. The first beam B1 and the second beam B2 are scanned along the scanning planes F1 and F2 parallel to the predetermined region S shown in FIG.

  Then, the polygon mirror 111 rotates R1 to scan the scanning surfaces F1 and F2 parallel to the predetermined area S at an angle. As described above, the first light emitting unit 120, the second light emitting unit 130, the first reflecting surface 111a, the second reflecting surface 111b, the first beam B1, and the second beam B2 face the predetermined region S, and scan surfaces F1 and F2. It is arranged so as to scan the light angle.

  In the present embodiment, the first reflecting surface 111a and the second reflecting surface 111b are adjacent surfaces so that the scanning incident angle does not become deep. This is because if the incident angle is deepened, the width of the beam on the polygon mirror 111 is widened, so that the scanning angle is reduced. However, the relationship between the first reflecting surface 111a and the second reflecting surface 111b is not limited to the present embodiment, and an arrangement location can be selected based on restrictions such as a space where the optical scanning unit 110 is arranged.

  The first light emitting unit 120 and the second light emitting unit 130 may be, for example, a laser diode that emits infrared laser light, but is not limited thereto.

The first beam B1 and the second beam B2 that angularly scan the light within the scanning planes F1 and F2 are incident on the first light receiving unit 140 and the second light receiving unit 150 that are disposed on the outer edge S1 facing the predetermined region, respectively.
In FIG. 1, the first light receiving unit 140 and the second light receiving unit 150 are disposed only on the outer edge S <b> 1 facing the optical scanning unit 110 across the scanning surface S, but are also disposed on the side surface of the scanning surface S. Then, the scanning surface S may be surrounded. Thus, the arrangement positions of the first light receiving section 140 and the second light receiving section 150 are not limited to the present embodiment, and the arrangement positions can be selected based on restrictions such as space and the position of the indicator M.

  Reference is also made to FIG. 2, which is a perspective view seen from the direction of arrow A in FIG. 1. Here, FIGS. 1 and 2 show two moments when the polygon mirror 111 is rotating. That is, when the polygon mirror 111 rotates R1, the laser light emitted from the first light emitting unit 120 is reflected by the first reflecting surface 111a to become the first beam B1, and the starting light on the side surface of the pointing object M. The moment when the first light guide 144 constituting the first light receiving unit 140 comes into contact with the contact a 143 and the laser light emitted by the second light emitting unit 130 is reflected by the second reflecting surface 111b, and the second The moment of reaching the first light guide 154 constituting the second light receiving unit 150 in contact with the start contact b153 on the side surface of the indicator M, and these moments will be described later. However, they may not occur at the same time, but are shown for convenience of explanation.

Referring to FIGS. 2 and 3, the first beam B <b> 1 is reflected by the first reflection point 146 in the first reflection surface 111 a assigned to the upper side of the polygon mirror 111, and the starting contact point a <b> 143 on the upper side of the indicator M. Then, the light is incident on the light guide 144 arranged so as to correspond to the first reflection point 146.
Similarly, the second beam B2 is reflected by the second reflecting point 156 in the second reflecting surface 111b assigned to the lower side of the polygon mirror 111, and passes through so as to contact the starting contact b153 on the lower side of the indicator M. Then, the light is incident on the light guide 154 arranged so as to correspond to the second reflection point 156.

  In the present embodiment, the first beam B1 and the second beam B2 are divided vertically so as to avoid the crossing as much as possible. However, the present invention is not limited to this configuration.

The first light receiving unit 140 uses the internal reflection of a transparent resin such as acrylic resin to efficiently guide light incident from one side to the other, and the first light receiving body that receives the guided light. 145.
The second light receiving unit 150 has the same configuration as the first light receiving unit 140, and includes a second light guide 154 and a second light receiver 155.
The first light receiving unit 140 and the second light receiving unit 150 are arranged in a vertical relationship in accordance with the ray trajectories of the first beam B1 and the second beam B2. With this configuration, it is possible to prevent the rays from intermingling.

  As the first light guide 144 and the second light guide 154, a bar light guide used in a scanner or the like can be applied. For example, the first light guide 144 or the second light guide 154 may include a micro prism inside, or a circumferential surface of a transparent acrylic bar. A simple configuration in which a tape or the like is attached to a part of the surface to form a reflective surface may be used. It can be arbitrarily selected from the required accuracy and the arrangement of the apparatus.

The first beam B1 and the second beam B2 incident on the first light guide body 144 and the second light guide body 154 pass through the light guide body, and the first light receiver 145 and the second light reception made of a photodiode or the like. Light is received by the body 155.
The light detected by the first light receiver 145 and the second light receiver 155 becomes a light detection signal, and angle scanning is executed by the angle signal acquired from the rotation R1 of the polygon mirror 111 of the light scanning unit 110.

These angular scans can be executed by a microprocessor (MPU) (not shown).
The MPUs drive and control the light emitting elements of the first light emitting unit 120 and the second light emitting unit 130, drive and control the rotation R1 of the polygon mirror 111, and light detection signals detected by the first light receiving unit 140 and the second light receiving unit 150. Then, the angle scanning result is calculated from the light detection signal and the angle signal.

[Explanation of light angle scanning method]
Next, mainly with reference to FIG. 4 and FIG. 5, a light angle scanning method according to an example of the present embodiment will be described. FIG. 4 shows that the light angle scanning proceeds in the order of (A) to (D) with the passage of time, and FIG. 5 shows the light detection signals detected by the first light receiving unit 140 and the second light receiving unit 150. It shows a temporal change of a certain amount of light.

The optical scanning unit 110 that has received a signal for starting optical angle scanning by the MPU drives the light emitting elements of the first light emitting unit 120 and the second light emitting unit 130, and rotationally drives the polygon mirror 111.
4 and 5, the optical scanning unit 110 irradiates the first beam B1 and the second beam B2 to the right ends of the first light receiving unit 140 and the second light receiving unit 150 at the scanning start time t0. Control. Then, the irradiation positions of the first beam B1 and the second beam B2 are sequentially moved to the left ends of the first light receiving unit 140 and the second light receiving unit 150 by the rotation R1 of the polygon mirror 111.

  In this embodiment, for example, scanning is started from the scanning start time t0 using a trigger sensor which is omitted in the drawing, but scanning may always be performed without using this sensor. It is possible and can be appropriately selected depending on the specifications of the apparatus.

  Note that the MPU measures the time from the start of optical scanning, and changes in the light amounts of the first beam B1 and the second beam B2 detected by the first light receiving unit 140 and the second light receiving unit 150 over time as shown in FIG. Is calculated.

  In FIG. 4A, the laser light emitted from the first light emitting unit 120 when the polygon mirror 111 rotates R1 is reflected by the first reflecting surface 111a to become the first beam B1, and the indicator M It is the instant t1 when it reaches the first light guide 144 constituting the first light receiving unit 140 in contact with the starting contact a143. Referring to FIG. 5, the light amount of the first beam B1 decreases at the instant t1, but the light amount of the second beam B2 does not change.

  In FIG. 4B, the laser light emitted from the second light emitting unit 130 as the polygon mirror 111 rotates R2 is reflected by the second reflecting surface 111b to become the second beam B2, and the indicator M It is the instant t2 when it reaches the first light guide 154 that constitutes the second light receiving unit 150 in contact with the start contact b153. Referring to FIG. 5, the light amount of the first beam B1 is further reduced as compared to the instant t1, and the light amount of the second beam B2 is also reduced at the instant t2.

  When the polygon mirror 111 further rotates (R2 to R3), the light amount of the first beam B1 becomes the lower limit first peak P1, as shown in FIG. The first peak P1 is a place where the light reaching the first light receiving unit 140 is blocked by the indicator M and the influence of the scattered light of the first beam B1 is minimized. Thus, the first peak P1 shows a clear sign that is easy to detect.

  FIG. 4C shows the instant t3 at which the first beam B1 reaches the final contact point a147 through the surface of the indicator M and reaches the first light guide 144 by the rotation R3 of the polygon mirror 111. . Referring to FIG. 5, the light amount of the first beam B1 returns to normal at the instant t3, but the light amount of the second beam B2 is further reduced due to the shielding of the indicator M and the influence of scattered light.

  When the polygon mirror 111 further rotates (R3 to R4), the light amount of the second beam B2 becomes the lower limit second peak P2 as shown in FIG. The second peak P2 is a portion where the light reaching the second light receiving unit 150 is blocked by the indicator M and the influence of the scattered light of the second beam B2 is minimized. As described above, the second peak P2 also shows a clear sign that is easy to detect, like the first peak P1.

  FIG. 4D shows the instant t4 when the polygon beam 111 rotates R4 so that the second beam B2 passes the surface of the indicator M, reaches the final contact point b156, and reaches the second light guide 154. . Referring to FIG. 5, the light amount of the first beam B1 is normal, and the light amount of the second beam B2 returns to normal after the moment t4.

  Thereafter, the rotation position of the polygon mirror 111 moves the irradiation positions of the first beam B1 and the second beam B2 to the left ends of the first light receiving unit 140 and the second light receiving unit 150, and the light angle scanning is completed.

  Referring to FIG. 5 again, the time difference Δt between the first peak P1 and the second peak P2 is calculated by the MPU from the result of detecting the transition of the light amount. This time difference Δt can be converted into an irradiation angle of the first beam B1 and the second beam B2 to the indicator M via the polygon mirror 111.

  The first beam B1 is a first reflection point 146 in the first reflection surface 111a assigned above the polygon mirror 111, and the second beam B2 is a second reflection surface assigned below the polygon mirror 111. The distance from the second reflection point 156 within 111b can be calculated geometrically.

  Thus, if the irradiation angle θ1 of the first beam B1 to the indicator M, the irradiation angle θ2 of the second beam B2 to the indicator M, and the distance w between the first reflection point 146 and the second reflection point 156 are known. The position of the indicator M can be detected by triangulation as shown in FIG.

That is, when the indicator M is arranged at the xy coordinates as shown in FIG. 6, Mx as the x coordinate and My as the y coordinate of the indicator M are expressed by the equations (1) and (2), respectively. The
Mx = tan θ1 / (tan θ2 + tan θ1) × w (1)
My = (tan θ1 × tan θ2) / (tan θ2 + tan θ1) × w (2)

  As described above, the coordinates of the indicator M can be detected by the light angle scanning method according to an example of the present embodiment.

  Note that the width Φx of the indicator M with respect to the irradiation positions of the first beam B1 and the second beam B2 shown in FIG. 6 is sufficiently smaller than the distance w between the first reflection point 146 and the second reflection point 156. That is, it is desirable that w> Φx. That is, by setting w so as to satisfy this condition for the width Φx of the indicator M, the angle error can be reduced and the detection accuracy can be improved.

  According to the present embodiment, angle scanning is performed by one polygon mirror 111 and two laser beams (first beam B1 and second beam B2) synchronized by the one polygon mirror 111, so the number of parts is small. A simple configuration can be achieved.

  Further, according to the present embodiment, the two laser beams (the first beam B1 and the second beam B2) are provided with the respective light receiving portions (the first light receiving portion 140 and the second light receiving portion 150), and the indicator M is By scanning, the coordinates are calculated using the change in the amount of light that is the measurement value of the directly irradiated laser beam instead of the scattered light from the indicator as in the techniques shown in Patent Documents 1 and 2. Therefore, it is possible to perform accurate position detection with less influence of disturbance without depending on weak scattered light, and improve measurement accuracy.

  Furthermore, according to the present embodiment, it is possible to irradiate two laser beams (first beam B1 and second beam B2) simultaneously by measuring the change in the amount of light that is not easily affected by disturbance as described above. Measurement time can be shortened.

[Second Embodiment]
Next, a position detection device 200 according to the second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in the method of receiving light.
Here, FIG. 7 is a plan view showing the entire position detection apparatus 200 according to the second embodiment of the present invention.

Referring to FIG. 7, an example of the position detection apparatus 200 according to the present embodiment detects the position of the indicator M in the predetermined area S, and includes an optical scanning unit 210 and a first light emitting unit 220. And a second light emitting unit 230, a first light receiving unit 240, and a second light receiving unit 250.
The first light receiver 240 includes a first light receiver 245 and a deflection unit 262, and the second light receiver 250 includes a second light receiver 255 and a deflection unit 263.

  In the present embodiment, a retroreflector 261 is disposed on the outer edge S2 facing the predetermined region S. The retroreflector 261 is made of a retroreflective material using glass beads or prisms, and always returns light in the incident direction with respect to light incident from any direction.

  The first beam B <b> 1 and the second beam B <b> 2 that are light emitted by the first light emitting unit 220 and the second light emitting unit 230 are incident on the deflecting units 262 and 263. The deflecting units 262 and 263 are so-called beam splitters, and divide the light beam into two. That is, the deflecting units 262 and 263 reflect a part of the light returned from the retroreflector 261 in another direction of the light receivers 245 and 255 and transmit the rest to the light emitting units 220 and 230 side.

  The deflecting units 262 and 263 may be a perforated mirror in which a hole is formed in a part of the reflecting surface. Since the light returned from the retroreflector 261 is spread, most of it is reflected to the light receiver side, so that the loss of light is greatly reduced and the same effect can be obtained.

  In the present embodiment, the first beam B1 and the second beam B2 pass through the deflecting units 262 and 263, reach the first reflecting surface 211a and the second reflecting surface 211b of the polygon mirror 211, and are reflected in directions. The predetermined area S is scanned.

  The first beam B1 and the second beam B2 that have reached the outer edge S2 are returned to the incident direction by the retroreflector 261, and reach the first reflecting surface 211a and the second reflecting surface 211b of the polygon mirror 211 again.

The first beam B1 and the second beam B2 reflected by the first reflecting surface 211a and the second reflecting surface 211b are incident on the deflecting units 262 and 263 again, but the deflecting units 262 and 263 are incident from this direction. The light is reflected and received by the first light receiving body 245 and the second light receiving body 255.
Here, the arrangement relationship between the first light emitting unit 220 and the second light emitting unit 230 and the arrangement relationship between the first light receiving unit 240 and the second light receiving unit 250 are the same as those in the first embodiment shown in FIGS. Similarly, by arranging them at different positions in the vertical direction with respect to the scanning plane, it is possible to prevent the crossing of the light beams.

  In the present embodiment, similarly to the first embodiment, a laser diode or the like can be applied to the first light emitting unit 220 and the second light emitting unit 230, and a photodiode is used as the first light receiving body 245 and the second light receiving body 255. Etc. can be applied.

  The angle scanning method is performed by the rotation R5 of the polygon mirror 211 as in the first embodiment. Here, FIG. 7 shows two moments of the rotating polygon mirror 211 as in FIG. 1 of the first embodiment. That is, the laser light emitted from the first light emitting unit 220 as the polygon mirror 211 rotates R5 is reflected by the first reflecting surface 211a, becomes the first beam B1, and starts on the side surface of the indicator M. The moment at which the first light receiving unit 240 is detected in contact with the contact point a243 and the laser light emitted from the second light emitting unit 230 are reflected by the second reflecting surface 211b to become the second beam B2 to indicate And the moment detected by the second light receiving unit 250 in contact with the starting contact b253 on the side surface of the object M, and these moments may not occur simultaneously as described in the first embodiment. However, it is shown for convenience of explanation.

  Since the position detection and coordinate calculation of the pointing object M in the present embodiment are the same as those in the first embodiment, description thereof will be omitted.

  According to the present embodiment, since the know-how and experience values of the prior art shown in Patent Documents 1 and 2 can be reflected as they are, the existing configuration can be diverted, and highly reliable position detection is possible. Can be measured.

[Third Embodiment]
Next, a position detection system 300 according to the third embodiment of the present invention will be described with reference to FIGS.
Here, FIG. 8 is a plan view showing an arrangement method of the position detection apparatus according to the third embodiment of the present invention, and FIG. 9 is a graph for explaining the scanning process of the position detection apparatus shown in FIG.

  Referring to FIG. 8, a position detection system 300 as an example in the present embodiment includes a plurality of position detection devices 100 or 200 described so far, the first position detection unit 310 and the second position detection unit. As 320, it arrange | positions so that the predetermined area | region S can face.

  Three indicators MA, MB, and MC are arranged in the predetermined area S, and the position detection system 300 detects the position of any of these indicators MA, MB, and MC. The position detection of the indicator MC that becomes the blind spot of the objects MA and MB will be described below.

  The first position detection unit 310 and the second position detection unit 320 include an optical scanning unit 110, a first light emitting unit 120, a second light emitting unit 130, a first light receiving unit 140, and a second light receiving unit 150. Even in the configured position detection device 100 of the first embodiment, the optical scanning unit 210, the first light emitting unit 220, the second light emitting unit 230, the first light receiving unit 240, and the second light receiving unit 250 are configured. The position detection device 200 according to the second embodiment may be any of the above.

  Also in the position detection system 300 in the present embodiment, the configuration of the first position detection unit 310 and the second position detection unit 320 is not limited to either the position detection device 100 or the position detection device 200 as described above.

  The position detection system 300 includes a first light receiving device 340 having both a first light receiving unit and a second light receiving unit corresponding to the first position detection unit 310, a first light receiving unit corresponding to the second position detection unit 320, and a first light receiving unit. A second light receiving device 350 having two light receiving portions is provided.

  In addition, by arranging the first position detection unit 310 and the second position detection unit 320 on either side, the first light receiving device 340 and the second light receiving device 350 are configured as shown in FIG. Unlike the case, it can be arranged so as to surround the predetermined region S. By arranging in this way, the first position detection unit 310 and the second position detection unit 320 can scan the three indicators MA, MB, and MC without being affected by the mutual beams. As described above, the first light receiving device 340 and the second light receiving device 350 can select the arrangement location as shown in FIG.

  Here, the first light receiving device 340 and the second light receiving device 350 may be configured by a light guide, or may be configured by a light retroreflector and a deflection unit incorporated in the unit.

  Referring to FIG. 8, the beam BA is irradiated from the position A of the first position detection unit 310 located on the left side of the drawing, and the beam BB is irradiated from the position B. Similarly, the beam BC is irradiated from the position C of the first position detection unit 320 located on the right side of the drawing, and the beam BD is irradiated from the position D.

  The distance w between the position A and the position B and the distance between the position C and the position D are arranged so that w> Φx with respect to the width Φx facing the scanning direction of the indicators MA, MB, MC. The positions A, B, C, and D correspond to the reflection points in the first and second embodiments.

  The beam BA rotates from BA1 to BA2 and scans the predetermined area S, the beam BB rotates from BB1 to BB3 and scans the predetermined area S, and the beam BC rotates from BC1 to BC3 and the predetermined area S The beam BD rotates from BD1 to BD2 and scans the predetermined area S.

  Referring to FIG. 8, the beam BA1 irradiated from the first position detection unit 310 scans the predetermined area S at an angle, but the pointer MC cannot be scanned over the entire surface because it is shielded by the pointer MA. . For such a state, in FIG. 8, the alternate long and short dash line represents the actual light beam emitted from the right side of each unit diagram, and the alternate long and two short dashes line represents the actual light beam emitted from the left side of each unit diagram. The broken line represents a virtual ray that does not actually exist but is not shielded by an indicator or the like.

  Referring to FIG. 9, the amount of light obtained by processing the signal detected by the angular scanning by the beam BA of the first position detection unit 310 decreases from the moment when the beam BA reaches the indicator MA. The beam BA that has become a virtual ray as shown by the broken line in FIG. 9 reaches the indicator MC, but since it is shielded by the indicator MA, the beam BA of the real ray cannot reach the indicator MC. Therefore, a decrease in the amount of light due to the indicator MC cannot be detected (see BA1 and virtual ray BA1). After that, when the beam BA returns to the normal light amount and reaches the indicator MB, the light amount of the actual beam BA decreases again (see BA2). As scanning progresses further, the amount of light returns to normal again.

  Similarly, the amount of light obtained by processing the signal detected by angle scanning with the beam BB of the first position detection unit 310 decreases from the moment when the beam BB reaches the indicator MA. The beam BA reaches the indicator MC before the scanning of the indicator MA is completed. However, since a part of the beam BB reaching the indicator MC is shielded by the indicator MA, the light amount is in a normal state. Decrease without returning (see BB1, BB2). Thereafter, the light amount is once returned to the normal light amount, and when the beam BB reaches the indicator MB, the light amount of the actual light beam BB decreases again (see BB3). As scanning progresses further, the amount of light returns to normal again.

  Next, the amount of light obtained by processing the signal detected by the angular scanning with the beam BC of the second position detection unit 320 decreases from the moment when the beam BC reaches the indicator MA (see BC1). After that, once the light amount returns to the normal light amount and the beam BC reaches the indicator MC, the light amount of the actual light beam BC decreases again (see BC2). The beam BC reaches the indicator MB before the scanning of the indicator MC is completed, but a part of the beam BC reaching the indicator MC is shielded by the indicator MB, so that the amount of light is in a normal state. Decrease without returning (see BC3). As scanning progresses further, the amount of light returns to normal again.

  Similarly, the amount of light obtained by processing the signal detected by the angular scanning with the beam BD of the second position detection unit 320 decreases from the moment when the beam BD reaches the indicator MA (see BD1). After that, when the light amount returns to the normal light amount and the beam BD reaches the indicator MB, the light amount of the actual light beam BD decreases again (see BD2). The beam BD that has become a virtual ray reaches the indicator MC, but since the beam BD of the real ray cannot reach the indicator MC because it is shielded by the indicator MB, the light quantity by the indicator MC The decrease in cannot be detected. As scanning progresses further, the amount of light returns to normal again.

  Referring to FIG. 9 with reference to FIG. 5, it is possible to detect the peak at which the light amount becomes the lower limit by the indicators MA, MB, and MC with time. Then, the position of the indicator MA can be detected based on triangulation as shown in FIG. 6 based on the time difference between any two peaks of BA1, BB1, BC1, and BD1, which are peaks corresponding to the indicator MA. it can.

  Similarly, the position of the indicator MA can be detected by the time difference between any two peaks of BA2, BB3, BC3, and BD2, which are peaks corresponding to the indicator MB.

  Next, also for the indicator MC, the position of the indicator MC can be detected from the time difference between the two peaks corresponding to BB2 and BC2. As described above, even if the position of the pointing object is blocked by another pointing object that could not be detected by one position detection unit, it is possible to detect the position by providing a plurality of position detection units.

  In the position detection methods described in Patent Literatures 1 and 2, scattered light that is reflected by the laser beam irradiated on the finger or the indicator and the reflected light that is reflected by the light retroreflector are received by the light receiving unit. However, the position coordinates are detected by detecting the scattered light in the light receiving unit.

Therefore, in the arrangement state of the indicators MA, MB, and MC as shown in FIG. 8, even if the position detection device according to the prior art is installed at the positions of the first position detection unit 310 and the second position detection unit 320, most of the parts are included. An angle scan of the indicator MC that becomes a blind spot cannot be performed.
Therefore, in order to perform angular scanning of the indicator MC with the position detection device according to the related art, it is necessary to add a new position detection device at a position where the indicator MC can face as a field of view.

  However, according to the present embodiment, when viewed from the first position detection unit 310 and the second position detection unit 320 shown in FIG. 8, the indicator MC has many blind spots of the indicator MA and the indicator MB, Even when only a part of the object can be scanned, the position of the indicator MC can be detected.

  Further, according to the present embodiment, reliable position detection can be performed with a small number of components compared to the position detection device according to the related art.

  This is the end of the description of the present embodiment, but the aspect of the present invention is not limited to the above-described embodiment, and modifications can be made without departing from the scope of the present invention.

100, 200, 300 ... Position detection device 110, 210 ... Optical scanning unit 111, 211 ... Polygon mirror 111a, 211a ... First reflection surface 111b, 211b ... Second reflection surface 120, 220 ... 1st light emission part 130, 230 ... 2nd light emission part 140, 240 ... 1st light-receiving part 143, 243 ... start contact a
144: First light guide 145, 245: First light receiver 146: First reflection point 147: Final contact point a
150, 250 ... second light receiving portion 153, 253 ... start contact b
154... Second light guide 155, 255... Second light receiver 156... Second reflection point 157.
261: Retroreflector 262, 263: Deflection section 310 ... First position detection unit 320 ... Second position detection unit 340 ... First light receiving device 350 ... Second light receiving device F1, F2 ... scanning surface S ... predetermined region S1, S2, S3 ... outer edge M, MA, MB, MC ... indicator B1 ... first beam B2 ... second beam BA , BB, BC, BD ... beam P1 ... first peak P2 ... second peak R1, R2, R3, R4, R5 ... rotation

Claims (7)

In an optical position detection device for detecting the position of an indicator within a predetermined area,
An optical scanning unit that is arranged so as to face the predetermined region, has a polygon mirror, and performs angular scanning of light in a scanning plane that is parallel to the predetermined region;
A first light emitting part and a second light emitting part for irradiating light to each of two reflecting surfaces having an angle with each other of the polygon mirror;
A first light-receiving unit that emits light and receives a first beam reflected by one reflecting surface of the polygon mirror;
A second light receiving portion that emits light from the second light emitting portion and receives a second beam reflected by another reflecting surface of the polygon mirror;
The optical position detection device, wherein the optical scanning unit scans the indicator by rotating the polygon mirror.   The first light receiving unit and the second light receiving unit have a light guide disposed so as to overlap an outer edge facing the predetermined region, and the first beam and the second light incident on the light guide, respectively. The optical position detection device according to claim 1, wherein the optical position detection device receives a beam. A retroreflector disposed on an outer edge facing the predetermined region;
A deflecting unit that deflects reflected light from the retroreflector to the optical scanning unit,
2. The optical position detection according to claim 1, wherein the first light receiving unit and the second light receiving unit receive the first beam and the second beam deflected by the deflecting unit, respectively. apparatus. The first light emitting unit irradiates the first reflecting position on the one reflecting surface with the light so that the first light receiving unit receives the first beam;
The said 2nd light emission part irradiates the said light to the 2nd reflective position in said other reflective surface so that a said 2nd light-receiving part may receive the said 2nd beam, The light is characterized by the above-mentioned. Item 4. The optical position detection device according to Item 3. The first reflection position and the second reflection position are arranged at different positions in a direction perpendicular to the scanning plane,
The optical position detection device according to claim 4, wherein the first light receiving unit and the second light receiving unit are arranged according to the first reflection position and the second reflection position.   A plurality of optical position detection devices according to any one of claims 1 to 5 are arranged at different positions facing the predetermined area, respectively. An optical position detection method using the optical position detection device according to any one of claims 1 to 5,
The first light emitting unit and the second light emitting unit simultaneously emit the first beam and the second beam;
The light scanning unit rotates the polygon mirror to scan the indicator;
The first light receiving unit and the second light receiving unit receive light amounts of the first beam and the second beam,
An optical position detection method, comprising: calculating a position of the indicator based on a temporal change in light amounts of the received first beam and second beam.