JP2013003997A - Optical position detector and display system with input function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical position detector and a display system with an input function which are capable of detecting a position of an object accurately when a plurality of light receiving elements receive reflected light from the object regardless of a high/low output level from each light receiving element.SOLUTION: In an optical position detector 10, when detection light is emitted from a light source section 12, a light receiving section 13 receives reflected light from an object Ob by a first light receiving element 131 and a second light receiving element 132. A signal processing section 71, in adding signals outputted from the first light receiving element 131 and the second light receiving element 132, and outputting the added signal to a position detecting section 50 as a signal for detection, multiplies the added output by the first magnification, and outputs the signal as a signal for detection, when the added output is a threshold value or less, and multiplies the added output by the second magnification smaller than the first magnification, and outputs the signal as a signal for detection, when the added output exceeds the threshold value.

Description

  The present invention relates to an optical position detection device that optically detects the position of a target object, and a display system with an input function including the optical position detection device.

  As an optical position detection device for optically detecting a target object, a plurality of point light sources are provided at positions separated from each other, and detection light is emitted from each of the plurality of point light sources toward the target object via a translucent member. In this case, there has been proposed one in which detection light reflected by a target object passes through a translucent member and is detected by a light receiving unit (see, for example, Patent Document 1). In addition, an optical position detection device has been proposed in which detection light emitted from each of a plurality of point light sources is emitted through a light guide plate, and detection light reflected by a target object is detected by a light receiving unit ( For example, see Patent Documents 2 and 3).

  In such an optical position detection device, one light receiving element is used as the light receiving unit, and an output from the light receiving element when some of the point light sources are turned on and another part of the point light source are provided. The position of the target object is detected based on the comparison result with the output from the light receiving element when it is turned on.

Special Table 2003-534554 JP 2010-127671 A JP 2009-295318 A

  However, in the configurations described in Patent Documents 1 to 3, it is difficult to extend the detection range because the light receiving element has sensitivity directivity. More specifically, for example, as shown in FIG. 15A, the light receiving element includes an element body 130b having a rectangular parallelepiped shape as a whole and terminals 130c protruding from both ends of the element body 130b. 130b includes a light receiving surface 130a on one side. The light receiving sensitivity of the light receiving element 130 has an incident angle dependency (sensitivity directivity) shown in FIG. 15B, and has a sensitivity peak direction in the normal direction to the light receiving surface 130a. As can be seen from FIG. 15B, when the incident angle of the detection light is tilted by 60 ° or more from the normal direction with respect to the light receiving surface 130a, the light receiving element 130 has a sensitivity of less than 1/2 of the sensitivity peak value. When the incident angle of the detection light is inclined by 90 ° or more from the normal direction to the light receiving surface 130a, the sensitivity becomes zero. For this reason, the detection range is limited to an angle range in which the incident angle of the detection light is incident with an inclination of, for example, 60 ° or less with respect to the normal direction to the light receiving surface 130a.

  Further, when the detection light is emitted, a part of the detection light reflected by an object other than the target object is incident on the light receiving element 130, so that the target object is located in a direction greatly inclined from the normal direction to the light receiving surface 130a. The output from the light receiving element 130 also has a problem that the ratio of components caused by detection light reflected by an object other than the target object and incident on the light receiving element 130 increases, and the detection accuracy decreases.

  Here, the inventor proposes to provide a plurality of light receiving elements in the light receiving portion. The inventor of the present application proposes to detect the position of the target object based on the addition output of the signals output from the plurality of light receiving elements. According to this configuration, even when detection light (reflected light) is incident on one light receiving element from an angle direction in which the light receiving sensitivity is reduced, the other light receiving element is detected light (reflected) from an angle direction with high light receiving sensitivity. Since the light enters, the detection range can be expanded.

  Here, in the case of the above configuration, if the input range in the position detection unit does not correspond to the maximum value of the addition output, the addition output overflows and the position of the target object cannot be detected. For example, when two light receiving elements are provided and the maximum value of a signal output from one light receiving element is 1V, the input range in the position detection unit needs to be set to 2V. However, when the input range in the position detection unit is expanded to 2V, the resolution is reduced correspondingly, and the position detection accuracy is reduced. Therefore, when a plurality of light receiving elements are provided, the resolution and the prevention of overflow are in a trade-off relationship in which if one is satisfied, the other is impaired.

  In view of the above problems, the problem of the present invention is that the detection range is expanded by receiving reflected light from a target object by a plurality of light receiving elements, and the output level from each light receiving element is affected. It is an object of the present invention to provide an optical position detection device that can accurately detect the position of a target object, and a display system with an input function that includes the optical position detection device.

  In order to solve the above problems, an optical position detection device of the present invention includes a light source unit that emits detection light, and a plurality of light receiving elements that receive the detection light reflected in the space from which the detection light is emitted. The added light obtained by adding a plurality of signals output from each of the plurality of light receiving elements and a threshold value are compared, and when the added output is less than or equal to the threshold value, the added output is multiplied by a first magnification. A level signal is output as a detection signal, and when the addition output exceeds the threshold value, a detection signal generation is performed in which a level signal obtained by multiplying the addition output by a second magnification smaller than the first magnification is output as a detection signal. And a position detection unit that detects the position of the target object in the space based on the detection signal.

  According to the present invention, the light receiving unit detects the detection light (reflected light) reflected in the space from which the detection light is emitted by the plurality of light receiving elements, and therefore, the light receiving sensitivity in one light receiving element among the plurality of light receiving elements. Even when the detection light is incident from the direction in which the light falls, the other light receiving elements can receive the detection light with high sensitivity. For this reason, the range in which the position of the target object can be detected can be expanded. In the present invention, an addition output obtained by adding a plurality of signals output from each of the plurality of light receiving elements is obtained, and the position of the target object is detected based on the addition output. For this reason, since the signal level used for position detection by the position detection unit is high, the position of the target object can be detected with high accuracy. Further, when the added output is less than or equal to the threshold value, a signal having a level obtained by multiplying the added output by the first magnification is output as a detection signal. On the other hand, when the added output exceeds the threshold value, the added output is multiplied by a second magnification smaller than the first magnification. A signal of the specified level is output as a detection signal. For this reason, signal overflow can be avoided without increasing the maximum value of the input range of the position detector. In addition, since the maximum value of the input range of the position detector can be set low, the position of the target object can be detected with high accuracy even if the addition output is at a low level. In addition, when the added output exceeds the threshold value, the level of the detection signal is set to be low, but such an event occurs because the detection accuracy is originally extremely high, for example, the target object is located near the light receiving unit. This corresponds to the case of being at a high position. Therefore, when the added output exceeds the threshold value, the position of the target object can be detected with relatively high accuracy even when the level of the detection signal is set to be low. Therefore, the position of the target object can be accurately detected regardless of the output level from the light receiving element.

  In the present invention, the detection signal generation unit includes, for example, a comparison unit that compares the addition output and the threshold value, an addition output amplification unit that amplifies the addition output and outputs the detection signal, and the comparison When the added output is equal to or lower than the threshold, the gain of the added output amplifying unit is set as a first gain, and when the added output exceeds the threshold, the gain of the added output amplifying unit is set to It is possible to adopt a configuration including an amplification factor switching unit that sets a second amplification factor smaller than the first amplification factor. According to such a configuration, the position of the target object can be detected with high accuracy regardless of the output level from the light receiving element with a relatively simple configuration in which the amplification factor is switched.

  In the present invention, the detection signal generation unit has a first resistance value when the addition output is equal to or less than the threshold value in the comparison unit comparing the addition output and the threshold value. The detection signal is output to the current limiting resistor through the addition output. When the addition output exceeds the threshold value, the detection signal is supplied to the current limiting resistor having a second resistance value larger than the first resistance value through the addition output. You may employ | adopt the structure provided with the current limiting resistance switching part which outputs a signal. According to such a configuration, the position of the target object can be detected with high accuracy regardless of the level of the output level from the light receiving element with a relatively simple configuration of switching the current limiting resistor.

  An optical position detection device according to another aspect of the present invention includes a light source unit that emits detection light and a light receiving unit that includes a plurality of light receiving elements that receive the detection light reflected in a space from which the detection light is emitted. And a detection signal generation unit that compares the intensities of a plurality of signals output from each of the plurality of light receiving elements, and outputs a signal having the maximum intensity among the plurality of signals as a detection signal, and the detection And a position detecting unit that detects the position of the target object in the space based on the signal for use.

  According to the present invention, the light receiving unit detects the detection light (reflected light) reflected in the space from which the detection light is emitted by the plurality of light receiving elements, and therefore, the light receiving sensitivity in one light receiving element among the plurality of light receiving elements. Even when the detection light is incident from the direction in which the light falls, the other light receiving elements can receive the detection light with high sensitivity. For this reason, the range in which the position of the target object can be detected can be expanded. In the present invention, since the signal having the maximum intensity among the plurality of signals output from each of the plurality of light receiving elements is used as the detection signal, the signal level used by the position detection unit for position detection is high. The position of the object can be detected with high accuracy. In addition, if the range that is allowed to be input by the position detector is set to a value corresponding to the maximum output for one light receiving element, the occurrence of overflow can be avoided and the input range of the position detector can be reduced. Can be set low. Therefore, the position of the target object can be accurately detected regardless of the output level from the light receiving element.

  In the present invention, it is preferable that the range allowed to be input by the position detection unit is set to a value corresponding to the maximum output of one light receiving element used in the light receiving unit.

  In the present invention, the light source unit emits the detection light so as to form a light intensity distribution whose intensity decreases from one side to the other side in the space during the first period. During the second period that does not overlap, the detection light is emitted so as to form a light intensity distribution that decreases in intensity from the other side toward the one side in the space, and the position detection unit Preferably, the position of the target object is detected based on the drive current value in the light source unit when the level of the detection signal in the second signal period is equal to the level of the detection signal in the second period. . According to such a configuration, there is an advantage that it is less affected by external light or the like as compared with the case where the position of the target object is detected based on the absolute value of the detection signal. In addition, unlike the case where the position of the target object is detected based on the absolute value of the detection signal, the higher the level of the detection signal, the higher the detection accuracy, so the effect of applying the present invention is significant. .

  In the present invention, the plurality of light receiving elements include a first light receiving element and a second light receiving element disposed at a position adjacent to the first light receiving element, and the first light receiving element and the second light receiving element. The light receiving element preferably extends in a direction in which normal directions to the light receiving surface intersect each other. According to this configuration, the first light receiving element and the second light receiving element complement each other, so that the detection range can be expanded with a small number of light receiving elements.

  In this case, it is preferable that the normal direction of the first light receiving element and the normal direction of the second light receiving element extend in directions that form an angle of 45 ° to 90 ° with each other. According to such a configuration, since the detection light is always incident on at least one of the first light receiving element and the second light receiving element from the higher sensitivity, the position of the target object can be detected with high accuracy.

  The optical position detection device according to the present invention can be used to configure a display system with an input function having a display device having a display surface on which an image is displayed. In this case, the display device includes the optical device. The image is switched based on the position of the target object in the direction along the display surface detected by the expression position detection device. According to the display system with an input function having such a configuration, it is possible to secure a wide detection space of the optical position detection device. Therefore, an operation such as switching an image by pointing an image displayed over a wide range with a target object is performed. It can be carried out.

  Moreover, the optical position detection device according to the present invention can be used to configure a display system with an input function having an image projection device for projecting an image. In this case, the image projection device is configured to have the optical position. The image is switched based on a position of the target object in a direction intersecting with a projection direction of the image detected by a detection device. According to the display system with an input function having such a configuration, it is possible to secure a wide detection space of the optical position detection device. Therefore, an operation such as switching an image by pointing a projection image displayed over a wide range with a target object. It can be performed.

It is explanatory drawing of the principal part of the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is a perspective view of the light emitting / receiving unit of the optical position detection device according to the first embodiment of the present invention. It is explanatory drawing which shows the structure of the principal part of the light emitting / receiving unit of the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the detection light radiate | emitted from the light emitting / receiving unit of the optical position detection apparatus which concerns on Embodiment 1 of this invention. In the optical position detection apparatus according to Embodiment 1 of the present invention, it is an explanatory diagram showing a positional relationship between two light receiving elements used in a light receiving unit. It is explanatory drawing of the control system of the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the position detection principle in the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the principle which acquires the XY coordinate data of a target object in the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the signal processing part of the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the signal processing part of the optical position detection apparatus which concerns on the modification of Embodiment 1 of this invention. It is explanatory drawing of the control system of the optical position detection apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the signal processing part of the optical position detection apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the specific example 1 (display system with an input function) of the position detection system to which this invention is applied. It is explanatory drawing of the specific example 2 (display system with an input function / projection type display system with an input function) of the position detection system to which this invention is applied. It is explanatory drawing of the light receiving element used with an optical position detection apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, directions intersecting each other are defined as an X-axis direction and a Y-axis direction, and directions intersecting the X-axis direction and the Y-axis direction are defined as a Z-axis direction. In the drawings referred to below, one side in the X-axis direction is the X1 side, the other side is the X2 side, one side in the Y-axis direction is the Y1 side, the other side is the Y2 side, and one side in the Z-axis direction The side is represented as the Z1 side, and the other side is represented as the Z2 side.

[Embodiment 1]
(overall structure)
FIG. 1 is an explanatory diagram of a main part of the optical position detection device according to Embodiment 1 of the present invention. FIG. 1A is an explanatory diagram when the optical position detection device is viewed from an oblique direction on the detection light emission space side, and FIG. 1B is an explanatory diagram when the optical position detection device is viewed from the front. .

  The position detection system 1 of this embodiment includes an optical position detection device 10 that detects the position of the target object Ob. The optical position detection device 10 detects the position of the target object Ob by using the detection light L2 emitted radially along a virtual XY plane (virtual plane) defined by the X-axis direction and the Y-axis direction. To do. In this embodiment, the position detection system 1 includes a viewing surface constituent member 40 that includes a viewing surface 41 that extends along the XY plane on one side Z1 in the Z-axis direction. The detection light L2 is emitted along the surface 41, and the position of the target object Ob located on the viewing surface 41 side (one side Z1 in the Z-axis direction) with respect to the viewing surface constituent member 40 is detected. Accordingly, the detection space 10R of the position detection system 1 is a detection light emission space from which the detection light L2 is emitted in the optical position detection device 10, and a light intensity distribution of the detection light L2 described later is formed in the detection space 10R. Is done. The position detection system 1 can be used as a display system with an input function such as an electronic blackboard, which will be described later, or a projection display system with an input function, by the optical position detection device 10.

  In the position detection system 1 of the present embodiment, the optical position detection device 10 includes a light source unit 12 that can emit the detection light L2 radially along the viewing surface 41 (XY plane), and an emission range (detection space) of the detection light L2. And a light receiving unit 13 that receives the detection light L2 (reflected light L3) reflected by the target object Ob located at 10R).

  The optical position detection apparatus 10 includes two light source units 12 (first light source unit 12A and the first light source unit 12A) facing the detection space 10R at positions separated from the viewing surface constituent member 40 on one side Y1 in the Y-axis direction as the light source unit 12. The first light source unit 12A and the second light source unit 12B are separated in the X-axis direction and are in the same position in the Y-axis direction. In addition, the optical position detection device 10 includes, as the light receiving unit 13, the first light receiving unit 13 </ b> A and the second light receiving unit that face the detection space 10 </ b> R at positions separated from the viewing surface constituent member 40 on one side Y <b> 1 in the Y axis direction. 13B, the first light receiving unit 13A and the second light receiving unit 13B are separated in the X-axis direction and are in the same position in the Y-axis direction.

  Here, 13 A of 1st light-receiving parts are arrange | positioned in the radiation | emission center position of the detection light L2 (detection light L2a) radiate | emitted radially from the 1st light source part 12A, 13A of 1st light-receiving parts and 12 A of 1st light source parts Is integrated as a light emitting / receiving unit 15 (first light emitting / receiving unit 15A). The second light receiving unit 13B is disposed at the radiation center position of the detection light L2 (detection light L2b) emitted radially from the second light source unit 12B, and the second light receiving unit 13B, the second light source unit 12B, Are integrated as a light emitting / receiving unit 15 (second light emitting / receiving unit 15B).

  The first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B are located at positions projecting from the viewing surface constituting member 40 to one side Z1 in the Z-axis direction. The first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B operate in different periods. Accordingly, in the first light receiving / emitting unit 15A, when the detection light L2a is emitted from the first light source unit 12A, the first light receiving unit 13A detects the detection light L2a (reflected) reflected by the target object Ob located in the detection space 10R. Light L3) is received. In a period different from this operation, when the detection light L2b is emitted from the second light source unit 12B in the second light receiving and emitting unit 15B, the second light receiving unit 13B is reflected by the target object Ob located in the detection space 10R. Detection light L2b (reflected light L3) is received.

(Light emitting / receiving unit)
FIG. 2 is a perspective view of the light emitting / receiving unit 15 of the optical position detection device 10 according to Embodiment 1 of the present invention. FIG. 3 is an explanatory diagram showing the configuration of the main part of the light emitting / receiving unit 15 of the optical position detection device 10 according to Embodiment 1 of the present invention. FIG. 4 is an explanatory diagram of the detection light L2 emitted from the light emitting / receiving unit 15 of the optical position detection device 10 according to the first embodiment of the present invention, and FIG. 4A is the first lighting in the first period. FIG. 4B shows a state in which the detection light L2 is emitted during the second lighting operation in the second period. As shown in FIGS. 2 and 3, in the optical position detection device 10 of the present embodiment, the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B have the same configuration. The configuration of the light emitting / receiving unit 15A will be mainly described, and the detailed description of the second light emitting / receiving unit 15B will be omitted.

  As shown in FIG. 2, the first light source unit 12 </ b> A includes a fan-shaped holder 150 having a peripheral surface extending in a shape curved in the length direction (circumferential direction). The holder 150 has a structure in which a first holder 151 and a second holder 152 are overlapped in the Z-axis direction. The first holder 151 includes a fan-shaped flange 156a on the lower end side, and the second holder 152 is provided with a fan-shaped flange 156b on the upper end side. The portion sandwiched between the flange portions 156a and 156b is an emission portion from which the detection light L2 is emitted, and the flange portions 156a and 156b limit the emission range of the detection light L2 in the Z-axis direction.

  12 A of 1st light source parts are provided with the 1st light source module 126 and the 2nd light source module 127 which were arrange | positioned and overlapped with the Z-axis direction as an emission part of the detection light L2. In the first light source unit 12A, a portion sandwiched between the first light source module 126 and the second light source module 127 in the Z-axis direction is an incident unit 148 of the reflected light L3 from the target object Ob, and the incident unit A first light receiving portion 13 </ b> A is disposed behind 148.

  As shown in FIGS. 3 and 4, in the first light emitting / receiving unit 15A, each of the first light source module 126 and the second light source module 127 includes a light source 120 made of a light emitting element such as a light emitting diode, and an arc-shaped light guide. LG is provided. In the second light receiving / emitting unit 15B, as in the first light receiving / emitting unit 15A, each of the first light source module 126 and the second light source module 127 includes a light source 120 made of a light emitting element such as a light emitting diode, and an arc-shaped light guide. LG is provided.

  The first light source module 126 includes a first light source 121 as the light source 120. The first light source 121 is arranged with the emission direction facing the end surface of one end LG1 of the light guide LG. Further, the first light source module 126 includes an arc-shaped emission direction setting unit LE including the optical sheet PS and the louver film LF along the arc-shaped outer peripheral surface LG3 of the light guide LG. An arcuate reflecting sheet RS is provided along the arcuate inner circumferential surface LG4. Similar to the first light source module 126, the second light source module 127 also includes a second light source 122 as the light source 120. The second light source 122 is arranged with the emission direction facing the end surface of the other end LG2 of the light guide LG. Similarly to the first light source module 126, the second light source module 127 has an arcuate emission direction setting portion LE provided with an optical sheet PS, a louver film LF, and the like along the arcuate outer circumferential surface LG3 of the light guide LG. And an arcuate reflection sheet RS is provided along the arcuate inner circumferential surface LG4 of the light guide LG. As the first light source 121 and the second light source 122, light emitting elements such as LEDs (light emitting diodes) are used. The LED emits detection light L2 composed of infrared light having a peak wavelength of 840 to 1000 nm as diverging light. Note that at least one of the outer peripheral surface LG3 and the inner peripheral surface LG4 of the light guide LG is processed to adjust the emission efficiency of the detection light L2 from the light guide LG. As such a processing method, for example, a method of printing a reflective dot, a molding method of giving unevenness by a stamper or injection, or a groove processing method can be adopted. In the first light source module 126 and the second light source module 127, when the first light source 121 is turned on, the detection light L2 is emitted radially from the first light source module 126, and the second light source 122 is turned on. Detection light L2 is emitted radially from the second light source module 127.

(Configuration of the light receiving unit 13)
FIG. 5 is an explanatory diagram showing the positional relationship between two light receiving elements used in the light receiving unit 13 in the optical position detection device 10 according to Embodiment 1 of the present invention. Since the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B have the same configuration, the configuration of the first light receiving / emitting unit 15A will be mainly described, and the details of the second light emitting / receiving unit 15B will be described. Description is omitted.

  As shown in FIGS. 2 to 5, in the optical position detection device 10 of the present embodiment, the first light receiving / emitting unit 15 </ b> A includes a plurality of light receiving elements 130 in the first light receiving unit 13 </ b> A. More specifically, the first light receiving unit 13 </ b> A includes a first light receiving element 131 and a second light receiving element disposed at a position adjacent to the first light receiving element 131 in the X-axis direction as the plurality of light receiving elements 130. 132. Each of the plurality of light receiving elements 130 (the first light receiving element 131 and the second light receiving element 132) is, for example, a photodiode or a phototransistor, and in this embodiment, is a photodiode having a sensitivity peak in the infrared region. The configuration described with reference to FIG. 15 is provided.

  As shown in FIG. 5, the first light receiving element 131 and the second light receiving element 132 are disposed adjacent to each other with the light receiving surface 131a of the first light receiving element 131 and the light receiving surface 132a of the second light receiving element 132 inclined in opposite directions. The first light receiving element 131 and the second light receiving element 132 extend in a direction in which normal directions with respect to the light receiving surfaces 131a and 132a intersect each other. In the present embodiment, the first light receiving element 131 and the second light receiving element 132 correspond to the sensitivity directivity described with reference to FIG. 15, and the normal direction with respect to the light receiving surface 131a of the first light receiving element 131 and the second direction. The normal direction to the light receiving surface 132a of the light receiving element 132 extends in a direction that forms an angle θc of 45 ° to 90 ° with each other. Here, the angle θc formed by the normal direction to the light receiving surface 131a of the first light receiving element 131 and the normal direction to the light receiving surface 132a of the second light receiving element 132 is preferably in the range of 50 ° to 90 °. .

  Here, assuming that the angle direction corresponding to the center of the emission range of the detection light L2 emitted from the first light source unit 12A is the 0 ° direction, and the surface extending in the 0 ° direction is the virtual surface S, the first light receiving element. The light receiving surface 131a of 131 and the light receiving surface 132a of the second light receiving element 132 are arranged symmetrically with respect to the virtual surface S. Accordingly, the first light receiving range 131R of the first light receiving element 131 and the second light receiving range 132R of the second light receiving element 132 overlap in a predetermined angle range centered on the 0 ° direction.

  The second light receiving unit 13B of the second light receiving / emitting unit 15B also includes a first light receiving element 131 and a second light receiving element 132 as a plurality of light receiving elements 130, similarly to the first light receiving unit 13A.

(Control system)
6 is an explanatory diagram of a control system of the optical position detection device 10 according to the first embodiment of the present invention. FIGS. 6A and 6B are a block diagram of the control system and a light source driving unit. It is explanatory drawing which shows lighting operation etc. As shown in FIG. 6A, in the optical position detection device 10, the first light source unit 12A of the first light emitting / receiving unit 15A and the second light source unit 12B of the second light emitting / receiving unit 15B are connected to the control IC 70. Electrically connected. Further, the first light receiving unit 13A of the first light receiving / emitting unit 15A and the second light receiving unit 13B of the second light receiving / emitting unit 15B are electrically connected to the control IC 70 via the signal processing unit 71. The control IC 70 is electrically connected to a host control device 60 such as a personal computer.

  The control IC 70 has a plurality of circuits (not shown) that generate a reference clock, an A-phase reference pulse, a B-phase reference pulse, a timing control pulse, a synchronous clock, and the like. The control IC 70 also includes a pulse generator 75a that generates a predetermined drive pulse based on the A-phase reference pulse, a pulse generator 75b that generates a predetermined drive pulse based on the B-phase reference pulse, and a pulse generator The switch unit 76 controls which of the first light source 121 and the second light source 122 the drive pulse generated by the pulse generator 75 b and the pulse generator 75 b is applied to. The pulse generators 75 a and 75 b and the switch unit 76 constitute the light source driving unit 51.

  As illustrated in FIG. 6B, the light source driving unit 51 applies a driving pulse having a reverse phase to the first light source 121 and the second light source 122 to turn on the first light source 121 and turn off the second light source 122. The first lighting operation in the first period is performed, and the second lighting operation in the second period in which the second light source 122 is turned on and the first light source 121 is turned off.

  As a result, the first light intensity distribution LID1 is formed along the XY plane in the detection space 10R during the first lighting operation in the first period. The first light intensity distribution LID1 is shown in FIG. 4A from the angle direction corresponding to one end LG1 in the detection space 10R (outgoing range), as indicated by the length of the arrow. It has a light intensity distribution in which the intensity monotonously decreases in the angular direction corresponding to the other end LG2. On the other hand, the second light intensity distribution LID2 is formed along the XY plane in the detection space 10R during the second lighting operation in the second period. The second light intensity distribution LID2 has one end LG1 from the angular direction corresponding to the other end LG2 within the emission range, as shown in FIG. 4B by the length of the arrow in FIG. 4B. It is provided with a light intensity distribution in which the intensity monotonously decreases in the angle direction corresponding to. Here, in the optical position detection device 10, voltage amplitude modulation and pulse width modulation are performed when controlling the drive current value for the light source unit 12.

  The second light emitting / receiving unit 15B is electrically connected to the control IC 70 with the same configuration as the first light emitting / receiving unit 15A, and the light source driving unit 51 is the second light source unit 12B of the second light emitting / receiving unit 15B. In the same manner as in the first light source unit 12A, the first lighting operation is performed in the first period to form the first light intensity distribution LID1. Further, the second lighting operation is performed in the second period that does not overlap with the first period to form the second light intensity distribution LID2. Here, as shown in FIG. 6B, the light source driving unit 51 performs the first lighting operation (first period) and the second lighting operation (second period) of the first light source unit 12A of the second light emitting / receiving unit 15A. ), The first lighting operation (first period) and the second lighting operation (second period) of the second light source unit 12B of the second light emitting / receiving unit 15B are performed.

  In FIG. 6A again, the control IC 70 controls the light receiving amount measuring unit 73 and the pulse generators 75a and 75b based on the measurement result of the received light amount measuring unit 73 to control the light source 120 (first step) of the light source unit 12. An adjustment amount calculation unit 74 that adjusts the drive current value (first drive current value) of the drive pulse supplied to the first light source 121 and the second light source 122) is provided. The received light amount measurement unit 73 and the adjustment amount calculation unit 74 have a partial function of the position detection unit 50. The adjustment amount calculation unit 74 includes an analog-digital conversion unit that outputs control signals for the pulse generators 75a and 75b.

  Here, the signal output from the first light receiving element 131 of the light receiving unit 13 and the signal output from the second light receiving element 132 are input to the position detecting unit 50 of the control IC 70 via the signal processing unit 71. . Details of the signal processing unit 71 will be described later with reference to FIG.

  The control IC 70 is controlled by a control unit 61 of a host control device 60 such as a personal computer. The control device 60 constitutes a position detection unit 50 together with a received light amount measurement unit 73 and an adjustment amount calculation unit 74. A coordinate data acquisition unit 55 is included. Therefore, in this embodiment, the position detection unit 50 is configured by the received light amount measurement unit 73 and the adjustment amount calculation unit 74 of the control IC 70 and the coordinate data acquisition unit 55 of the host control device 60 (personal computer). .

  Here, the optical position detection device 10 of the present embodiment includes, as the light emitting / receiving unit 15, a first light emitting / receiving unit 15 </ b> A and a second light emitting / receiving unit 15 </ b> B arranged at positions separated from each other. For this reason, the coordinate data acquisition unit 55 detects the angular position of the target object Ob with respect to the radiation center of the first light source unit 12A based on the driving result for the first light emitting / receiving unit 15A, A second angular position detection unit 552 that detects the angular position of the target object Ob with respect to the radiation center of the second light source unit 12B based on the driving result for the second light emitting / receiving unit 15B. Also, the coordinate data acquisition unit 55 is based on the angular position of the target object Ob obtained by the first angular position detection unit 551 and the angular position of the target object Ob obtained by the second angular position detection unit 552. A coordinate data determination unit 553 is provided for determining the XY coordinate data of the target object Ob.

  In this embodiment, the control IC 70 is multi-channeled, and the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B are driven by one control IC 70. However, the first light emitting / receiving unit 15A and second Two control ICs 70 having a one-to-one relationship with the light emitting / receiving unit 15B may be used.

(Target object position detection)
FIG. 7 is an explanatory view of the position detection principle in the optical position detection device 10 according to the first embodiment of the present invention, FIG. 7 (a) is an explanatory view of the light intensity distribution, and FIG. It is explanatory drawing of the method of acquiring the positional information (angular position / azimuth information) in which the target object Ob exists. FIG. 8 is an explanatory diagram of the principle of acquiring the XY coordinate data of the target object Ob in the optical position detection device 10 according to the first embodiment of the present invention. In FIG. 7, the angle direction corresponding to the center of the emission range of the detection light L2 emitted from the light source unit 12 (front surface of the light receiving unit 13) is set to 0 °.

  In this embodiment, first, when the first light intensity distribution LID1 is formed by the first light source module 126 of the first light source unit 12A, the emission angle direction of the detection light L2 and the intensity of the detection light L2 are shown in FIG. a) is in a linear relationship indicated by a line E1. In addition, when the second light intensity distribution LID2 is formed by the second light source module 127 of the first light source unit 12A, the emission angle direction of the detection light L2 and the intensity of the detection light L2 are shown in FIG. There is a linear relationship indicated by E2. Here, as illustrated in FIGS. 7B and 8, it is assumed that the target object Ob exists in the direction of the angle θ when viewed from the center PE (radiation center position of the detection light L2) of the first light source unit 12A. In this case, when the first light intensity distribution LID1 is formed, the intensity of the detection light L2 at the position where the target object Ob is present is INTa. On the other hand, when the second light intensity distribution LID2 is formed, the intensity of the detection light L2 at the position where the target object Ob is present is INTb. Therefore, the detected light reception intensity at the first light receiving unit 13A when the first light intensity distribution LID1 is formed is compared with the detected light reception intensity at the first light receiving unit 13A when the second light intensity distribution LID2 is formed. If the relationship between the intensity INTa and INTb is obtained, as shown in FIG. 7B and FIG. 8, the angle θ (angle θ1 / angle) in the direction in which the target object Ob is located with respect to the center PE of the first light source unit 12A. Position).

  In detecting the angular position (angle θ1) of the target object Ob using this principle, in this embodiment, the first light receiving unit in the first period in which the first light intensity distribution LID1 is formed by the first light source unit 12A. The first light source unit 12A has a first intensity with respect to the first light source unit 12A so that the intensity of the signal output from the unit 13A is equal to the intensity of the signal output from the first light receiving unit 13A in the second period in which the second light intensity distribution LID2 is formed. The drive current value and the second drive current value for the first light source unit 12A are adjusted.

  Here, the intensity of the signal output from the first light source unit 12 </ b> A is proportional to the first drive current value for the light source 120 and the second drive current value for the light source 120. Therefore, when the ratio or difference between the first drive current value and the second drive current value after adjusting the first drive current value for the light source 120 and the second drive current value for the light source 120, or when the drive current value is adjusted. The angle θ (angle θ1) in the direction in which the target object Ob is located can be obtained from the ratio or difference of the adjustment amounts of the drive current values.

  More specifically, the light source driver 51 of the control IC 70 shown in FIG. 6A first turns on the first light source 121 as the first lighting operation to form the first light intensity distribution LID1, and then As the second lighting operation, the second light source 122 is turned on to form the second light intensity distribution LID2. At this time, the first light intensity distribution LID1 and the second light intensity distribution LID2 have opposite intensity changes, but the intensity levels are the same. Further, the first light receiving element 131 and the second light receiving element 132 of the first light receiving unit 13A detect the reflected light L3, and the signals output from the first light receiving element 131 and the second light receiving element 132 are transmitted to the signal processing unit 71. And output to the control IC 70 as a detection signal Vt.

  Then, the adjustment amount calculation unit 74 of the position detection unit 50 compares the detected light reception intensity INTa of the first light receiving unit 13A during the first lighting operation with the detected light reception intensity INTb of the first light receiving unit 13A during the second lighting operation. To do. As a result, if the detected light reception intensity INTa of the first light receiving unit 13A during the first lighting operation is equal to the detected light reception intensity INTb of the first light receiving unit 13A during the second lighting operation, the angular position of the target object Ob is 0. °.

  On the other hand, when the detected light reception intensities INTa and INTb are different, the detected light reception intensity INTa of the first light receiving unit 13A during the first lighting operation and the detected light reception of the first light receiving unit 13A during the second lighting operation. The first drive current value for the first light source 121 and the second drive current value for the second light source 122 are adjusted so that the intensity INTb is equal. Then, when the first lighting operation and the second lighting operation are performed again, the detected light reception intensity INTa of the first light receiving unit 13A during the first lighting operation and the detection of the first light receiving unit 13A during the second lighting operation. If the received light intensity INTb is equal, the first angular position detector 551 shown in FIG. 6 performs the ratio or difference of the drive current values with respect to the first light source 121 and the second light source 122 after such adjustment, or the drive current value. The angle θ (angle θ1) in the direction in which the target object Ob is located can be obtained from the adjustment amount ratio or difference.

  If such an operation is performed also in the second light source unit 12B, the second angular position detection unit 552 has an angle θ (angle θ2 / angular position) in a direction in which the target object Ob is positioned with respect to the center PE of the second light source unit 12B. Can be requested. Therefore, as shown in FIG. 8, the coordinate data determination unit 553 is configured to detect the angular position (angle θ1) detected by the first angular position detection unit 551 based on the distance DS between the first light receiving unit 13A and the second light receiving unit 13B. And the position corresponding to the intersection of the angular position detected by the second angular position detector 552 (the direction of the angle θ2) can be acquired as XY coordinate data where the target object Ob is positioned.

(Signal processing part)
FIG. 9 is an explanatory diagram of the signal processing unit 71 of the optical position detection device 10 according to the first embodiment of the present invention. FIGS. 9A and 9B are a block diagram of the signal processing unit 71, and FIG. 7 is an explanatory diagram illustrating a specific configuration example of a signal processing unit 71. FIG. Since the signal processing unit 71 is provided with the same configuration in both the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B, only the signal processing unit 71 for the first light emitting / receiving unit 15A will be described. The description of the signal processing unit 71 for the second light emitting / receiving unit 15B is omitted.

  As shown in FIG. 9A, in the optical position detection device 10, the signal processing unit 71 first includes a first IV conversion unit 91A, a first amplification unit 92A, a second IV conversion unit 91B, and Two amplifying units 92B are provided. The first IV conversion unit 91A removes a direct current component from the first signal (current waveform) output from the first light receiving element 131 and converts it to a first voltage signal. The first amplification unit 92A The signal is amplified and a first amplified signal is output. The second IV conversion unit 91B removes a direct current component from the second signal (current waveform) output from the second light receiving element 132 and converts it to a second voltage signal. The second amplification unit 92B The signal is amplified and a second amplified signal is output.

  The signal processing unit 71 includes an adding unit 93 and a detection signal generating unit 90. The adding unit 93 includes a first amplified signal from the first amplifying unit 92A and a second amplified signal from the second amplifying unit 92B. The signal is added to generate an added output Vs. The detection signal generator 90 amplifies the added output Vs, compares the amplified added output Vs with a preset threshold value, and sets the first magnification to the added output Vs when the added output Vs is equal to or less than the threshold value. A signal of the multiplied level is output to the position detection unit 50 as a detection signal Vt. When the addition output Vs exceeds a threshold value, a signal of a level obtained by multiplying the addition output Vs by a second magnification smaller than the first magnification is detected signal Vt. To the position detection unit 50. For this reason, the position detection unit 50 detects the position of the target object Ob based on the detection signal Vt output from the detection signal generation unit 90.

  In this embodiment, the detection signal generation unit 90 includes a comparison unit 95, an addition output amplification unit 94, and an amplification factor switching unit 96 (output adjustment unit). Here, the comparison unit 95 compares the addition output Vs with a threshold value, and the addition output amplification unit 94 amplifies the addition output Vs with a predetermined amplification factor. In the comparison result in the comparison unit 95, the amplification factor switching unit 96 sets the amplification factor of the addition output amplification unit 94 as the first amplification factor when the addition output Vs is less than or equal to the threshold value, and adds the output amplification when the addition output Vs exceeds the threshold value. The amplification factor of the unit 94 is set to a second amplification factor smaller than the first amplification factor. Therefore, in this embodiment, the first magnification corresponds to the first amplification factor, and the second magnification corresponds to the second amplification factor.

  The signal processing unit 71 can be configured as shown in FIG. 9B, for example. In FIG. 9B, a feedback resistor, an input resistor, and the like are used. However, the resistor is represented by a rectangle and the description thereof is omitted. As shown in FIGS. 9A and 9B, each of the first IV conversion unit 91A and the second IV conversion unit 91B includes a coupling capacitor 911 and an operational amplifier 912 including a feedback resistor and a feedback capacitor. The first amplifying unit 92A and the second amplifying unit 92B are configured by an operational amplifier 921 having a feedback resistor and a feedback capacitor. The adder 93 is composed of an operational amplifier 931.

  In the detection signal generation unit 90, the addition output amplification unit 94 includes an operational amplifier 941, a first feedback resistor 942, and a second feedback resistor 943. The comparison unit 95 includes a comparator 951 that compares a threshold value (reference voltage Vref) with the addition output Vs. The amplification factor switching unit 96 includes a switch 961 that selectively switches between the first feedback resistor 942 and the second feedback resistor 943 based on the comparison result by the comparator 951. Here, the first feedback resistor 942 has a larger resistance value than the second feedback resistor 943, and the switch 961 (amplification rate switching unit 96) normally has a large resistance value as a feedback resistor of the operational amplifier 941. One feedback resistor 942 is selected. The switch 961 (amplification rate switching unit 96) maintains the state where the first feedback resistor 942 is selected when the addition output Vs is equal to or less than the threshold in the comparison result of the comparator 951 (comparison unit 95). The amplification factor of the addition output amplification unit 94 is set to the first amplification factor. Therefore, when the addition output Vs is equal to or smaller than the threshold value, the detection signal generation unit 90 outputs a signal having a level obtained by multiplying the addition output Vs by the first magnification to the position detection unit 50 as the detection signal Vt.

  On the other hand, the switch 961 (amplification factor switching unit 96) switches to a state in which the second feedback resistor 943 is selected when the addition output Vs exceeds the threshold in the comparison result of the comparator 951 (comparison unit 95). . As a result, since the amplification factor of the addition output amplification unit 94 is switched to a second amplification factor smaller than the first amplification factor, the detection signal generation unit 90 multiplies the addition output Vs by a second magnification smaller than the first magnification. The level signal is output to the position detector 50 as the detection signal Vt.

  The position detection unit 50 detects the position of the target object Ob based on the detection signal Vt output from the detection signal generation unit 90. More specifically, the light source unit 12 is the light source unit 12 when the level of the detection signal Vt during the first period is equal to the level of the detection signal Vt during the second period. The position of the target object Ob is detected based on the drive current value. As shown in FIG. 6B, this operation is sequentially performed in the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B. As a result, the XY coordinates of the target object Ob are detected.

(Function and effect)
As described above, according to the present embodiment, the reflected light L3 from the target object Ob is detected using the plurality of light receiving elements 130 (the first light receiving element 131 and the second light receiving element 132) as the light receiving element 130. Therefore, when the reflected light L3 is incident on the first light receiving element 131 from the direction where the light receiving sensitivity is low, the reflected light L3 is incident on the second light receiving element 132 from the direction where the light receiving sensitivity is high. Similarly, when the reflected light L3 enters from the direction where the light receiving sensitivity is low in the second light receiving element 132, the reflected light L3 enters the first light receiving element 131 from the direction where the light receiving sensitivity is high. For this reason, the detection space 10R can be expanded.

  Further, in this embodiment, an added output Vs obtained by adding a plurality of signals output from each of the plurality of light receiving elements 130 (the first light receiving element 131 and the second light receiving element 132) is obtained, and based on the added output Vs, The position of the target object Ob is detected. For this reason, since the signal level used by the position detection unit 50 for position detection is high, the position of the target object Ob can be detected with high accuracy. More specifically, when the detection light L2 is emitted, a part of the detection light L2 reflected by an object other than the target object Ob is incident on the light receiving element 130. Therefore, the detection light L2 is in a direction greatly inclined from the normal direction to the light receiving surface. When the target object Ob is located, the output from the light receiving element 130 increases the ratio of components caused by the detection light reflected by the object other than the target object Ob and incident on the light receiving element 130. However, according to the present embodiment, the ratio of the component caused by the detection light L2 reflected by an object other than the target object Ob and incident on the light receiving element 130 is low in the addition output Vs and the detection signal Vt. Further, since the levels of the addition output Vs and the detection signal Vt obtained during the first period and the second period are high, the detection accuracy is high.

  Further, in this embodiment, when the added output Vs is equal to or smaller than the threshold value, a signal having a level obtained by multiplying the added output Vs by the first magnification is output as the detection signal Vt, while when the added output Vs exceeds the threshold value, A signal having a level multiplied by a second magnification smaller than 1 magnification is output as a detection signal Vt. For this reason, signal overflow can be avoided without increasing the maximum value of the input range of the position detector 50. In addition, since the maximum value of the input range of the position detection unit 50 can be set low, the position of the target object Ob can be detected with high accuracy even when the addition output Vs and the detection signal Vt are at a low level. it can. Note that when the added output Vs exceeds the threshold value, the level of the detection signal Vt is set to a low level. However, this phenomenon occurs because the target object Ob is located near the light receiving unit 13 or the like. Originally corresponds to a very high position. Therefore, even when the level of the detection signal Vt is set low when the added output Vs exceeds the threshold, the position of the target object Ob can be detected with relatively high accuracy. Therefore, the position of the target object Ob can be accurately detected regardless of the output level from the light receiving element 130.

  Furthermore, in this embodiment, since the reflected light L3 is detected in the light receiving unit 13 while the first light receiving element 131 and the second light receiving element 132 are simultaneously driven, the first light receiving element 131 and the second light receiving element 132 are The time for detecting the position of the target object Ob can be halved as compared with the case where the reflected light L3 is detected by driving separately at different time zones. Therefore, the response speed of the optical position detection device 10 is improved. Further, when the detection time is halved, the position detection operation of the symmetric object Ob can be performed intermittently, so that power consumption can be reduced. Furthermore, if the detection time is halved, a decrease in response speed can be suppressed even when the position detection operation is repeated. Therefore, the position detection accuracy can be improved without reducing the response speed.

[Modification of Embodiment 1]
10 is an explanatory diagram of the signal processing unit 71 of the optical position detection device 10 according to the modification of the first embodiment of the present invention. FIGS. 10A and 10B are block diagrams of the signal processing unit 71. FIG. It is explanatory drawing which shows the example of a specific structure of a figure and the signal processing part 71. FIG. Since the present embodiment is the same as the first embodiment except for the configuration of the signal processing unit 71, common portions are denoted by the same reference numerals and description thereof is omitted. Further, since the signal processing unit 71 is provided with the same configuration in both the first light emitting / receiving unit 15A and the second light receiving / emitting unit 15B, only the signal processing unit 71 for the first light receiving / emitting unit 15A will be described. The description of the signal processing unit 71 for the second light emitting / receiving unit 15B is omitted.

  As shown in FIG. 10A, also in the optical position detection device 10 of the present embodiment, as in the first embodiment, the signal processing unit 71 first includes a first IV conversion unit 91A and a first amplification unit 92A. , A second IV conversion unit 91B, and a second amplification unit 92B. In addition, the signal processing unit 71 includes an adding unit 93, which adds the first amplified signal from the first amplifying unit 92A and the second amplified signal from the second amplifying unit 92B. , Generate the addition output. The signal processing unit 71 has an addition output amplification unit 94 ′ that amplifies the addition output Vs.

  Further, the signal processing unit 71 compares the amplified addition output Vs output from the addition output amplification unit 94 ′ with a preset threshold value. When the addition output Vs is equal to or less than the threshold value, the signal processing unit 71 sets the first output to the addition output Vs. A signal having a level multiplied by the magnification is output to the position detection unit 50 as a detection signal Vt. When the added output Vs exceeds a threshold, a signal having a level obtained by multiplying the added output Vs by a second magnification smaller than the first magnification is used for detection. A detection signal generation unit 90 that outputs the signal Vt to the position detection unit 50 is provided. For this reason, the position detection unit 50 detects the position of the target object Ob based on the detection signal Vt output from the detection signal generation unit 90.

  In this embodiment, as the detection signal generation unit 90, the comparison unit 95 that compares the addition output Vs with the threshold value, and the detection signal Vt is output through the addition output Vs based on the comparison result of the comparison unit 95. A current limiting resistor switching unit 96 ′ (output adjusting unit) for switching the current limiting resistor. The current limiting resistor switching unit 96 ′ outputs a detection signal Vt through the addition output Vs to the current limiting resistor having the first resistance value when the addition output Vs is equal to or less than the threshold in the comparison result of the comparison unit 95, and adds When the output Vs exceeds the threshold value, the detection signal Vt is output through the addition output Vs to a current limiting resistor having a second resistance value larger than the first resistance value.

  In this embodiment, as shown in FIG. 10B, the addition output amplifying unit 94 ′ includes an operational amplifier 941 and a feedback resistor 945. The comparison unit 95 includes a comparator 951 that compares the addition output Vs amplified by the addition output amplification unit 94 ′ with the threshold value Vref. The current limiting resistor switching unit 96 ′ includes a first current limiting resistor 962 having a first resistance value, a second current limiting resistor 963 having a second resistance value larger than the first resistance value of the first current limiting resistor 962, The switch 964 is configured to selectively switch between the first current limiting resistor 962 and the second current limiting resistor 963 based on the comparison result by the comparator 951. In the initial state, the switch 964 (current limiting resistor switching unit 96 ′) selects the first current limiting resistor 962 having a small resistance value as the current limiting resistor. The switch 964 maintains the state where the first current limiting resistor 962 is selected when the addition output Vs is equal to or less than the threshold value in the comparison result of the comparator 951 (comparator 95).

  On the other hand, the switch 964 (current limiting resistor switching unit 96 ′) selects the second current limiting resistor 963 when the addition output Vs exceeds the threshold in the comparison result of the comparator 951 (comparing unit 95). Switch to the state. As a result, the detection signal generation unit 90 outputs a signal having a level obtained by multiplying the addition output Vs by the second magnification smaller than the first magnification to the position detection unit 50 as the detection signal Vt. Therefore, in this embodiment, the first magnification corresponds to the reciprocal of the first resistance value, and the second magnification corresponds to the reciprocal of the second resistance value.

  The position detection unit 50 detects the position of the target object Ob based on the detection signal Vt output from the detection signal generation unit 90. More specifically, the light source unit 12 is the light source unit 12 when the level of the detection signal Vt during the first period is equal to the level of the detection signal Vt during the second period. The position of the target object Ob is detected based on the drive current value. As shown in FIG. 6B, this operation is sequentially performed in the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B. As a result, the XY coordinates of the target object Ob are detected.

  As described above, also in this embodiment, as in the first embodiment, reflected light from the target object Ob using the plurality of light receiving elements 130 (the first light receiving element 131 and the second light receiving element 132) as the light receiving element 130. Since L3 is detected, the detection space 10R can be expanded. In this embodiment, the position of the target object Ob is determined based on the detection signal Vt corresponding to the addition output Vs of the signal output from the first light receiving element 131 and the signal output from the second light receiving element 132. To detect. For this reason, since the high-level detection signal Vt is input to the position detection unit 50, the position of the target object Ob can be accurately detected even when the detection space 10R is expanded.

  In this embodiment, the detection signal generation unit 90 of the signal processing unit 71 outputs a signal having a level obtained by multiplying the addition output Vs by the first magnification as the detection signal Vt when the addition output Vs is equal to or less than the threshold. When the addition output Vs exceeds the threshold value, a signal having a level obtained by multiplying the addition output Vs by a second magnification smaller than the first magnification is output as the detection signal Vt. Therefore, even when the input range of the position detection unit 50 is set low, Overflow can be avoided. In addition, since the input range of the position detector 50 can be set low, the position of the target object Ob can be detected with high accuracy even when the addition output Vs (detection signal Vt) is at a low level. The same effects as those of the first embodiment are obtained.

[Embodiment 2]
The optical position detection apparatus 10 according to the second embodiment of the present invention is different from the first embodiment in the method of controlling the driving of the light source unit by the light source driving unit 51 and the configuration of the signal processing unit 71. Since the configuration described with reference to FIGS. 1 to 5, 7, and 8 is the same as that of the first embodiment, the corresponding parts are denoted by the same reference numerals, and description thereof is omitted. Further, since the signal processing unit 71 is provided with the same configuration in both the first light emitting / receiving unit 15A and the second light receiving / emitting unit 15B, only the signal processing unit 71 for the first light receiving / emitting unit 15A will be described. The description of the signal processing unit 71 for the second light emitting / receiving unit 15B is omitted.

  FIG. 11 is an explanatory diagram of a control system of the optical position detection device 10 according to the second embodiment of the present invention. FIGS. 11A and 11B are a block diagram of the control system and a light source driving unit. It is explanatory drawing which shows lighting operation etc. 12 is an explanatory diagram of the signal processing unit 71 of the optical position detection device 10 according to the second embodiment of the present invention. FIGS. 12A and 12B are a block diagram of the signal processing unit 71, and FIG. 7 is an explanatory diagram illustrating a specific configuration example of a signal processing unit 71. FIG.

  As shown in FIG. 11A, also in the optical position detection device 10 of the present embodiment, the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B are electrically connected to the control IC 70 as in the first embodiment. The control IC 70 is electrically connected to the control device 60.

  In the control IC 70, as shown in FIG. 11B, the light source driving unit 51 first drives in phase with the first light source 121 and the second light source 122 of the first light source unit 12A of the first light emitting / receiving unit 15A. By applying a pulse, an initial lighting operation for simultaneously lighting the first light source 121 and the second light source 122 is performed. In the initial lighting operation, a light intensity distribution obtained by combining the first light intensity distribution LID1 and the second light intensity distribution LID2 described with reference to FIG. 4 is formed in the detection space 10R. A light intensity distribution having a constant intensity is formed from an angular direction corresponding to one end LG1 to an angular direction corresponding to the other end LG2.

  Next, the light source driving unit 51 applies first-phase driving pulses to the first light source 121 and the second light source 122 to turn on the first light source 121 and turn off the second light source 122 in the first period. The first light source unit 12A is caused to perform the lighting operation and the second lighting operation in the second period in which the second light source 122 is turned on and the first light source 121 is turned off.

  Note that the light source driving unit 51 first performs an initial lighting operation on the second light source unit 12B of the second light receiving and emitting unit 15B, similarly to the first light source unit 12A, to obtain the first light intensity distribution LID1. A light intensity distribution obtained by combining the second light intensity distribution LID2 is formed, and then the first lighting operation is performed in the first period to form the first light intensity distribution LID1, which does not overlap with the first period. In the second period, the second lighting operation is performed to form the second light intensity distribution LID2. The light source driving unit 51 performs the second light receiving operation after the initial lighting operation, the first lighting operation (first period), and the second lighting operation (second period) of the first light source unit 12A of the first light emitting / receiving unit 15A. The initial lighting operation, the first lighting operation (first period), and the second lighting operation (second period) of the second light source unit 12B of the light emitting unit 15B are performed.

  In the optical position detection device 10 configured as described above, the signal output from the light receiving unit 13 is input to the received light amount measurement unit 73 of the position detection unit 50 via the signal processing unit 71. In the present embodiment, as will be described below with reference to FIG. 12, the signal processing unit 71 adjusts the signal level output to the position detection unit 50 based on the light reception result in the initial lighting operation. One of the first light receiving element 131 and the second light receiving element 132 is selected, and the output result of the one light receiving element is output to the position detection unit 50. FIG. 11B illustrates a case where the second light receiving element 132 is selected in the first light emitting / receiving unit 15A, and the first light receiving element 131 is selected in the second light receiving / emitting unit 15A. For this reason, in the first light emitting / receiving unit 15A, during the initial lighting operation, both the first light receiving element 131 and the second light receiving element 132 are in the on state, but during the first lighting operation (first period) and During the second lighting operation (second period), only the second light receiving element 132 is in the on state, and the first light receiving element 131 is in the off state. In the second light emitting / receiving unit 15B, both the first light receiving element 131 and the second light receiving element 132 are in the on state during the initial lighting operation, but the first lighting operation (first period) and the second light receiving element 15B are in the on state. During the two lighting operation (second period), only the first light receiving element 131 is in the on state and the second light receiving element 132 is in the off state.

  In realizing this operation, as shown in FIG. 12A, the signal processing unit 71 of the present embodiment, first, as in the first embodiment, first, the first IV conversion unit 91A, the first amplification unit 92A, the first A 2I-V conversion unit 91B and a second amplification unit 92B are included.

  Further, the signal processing unit 71 compares the intensity of the signal output from each of the first light receiving element 131 and the second light receiving element 132, and outputs the signal having the maximum intensity as a detection signal Vt among these signals. The detection signal generation unit 99 is provided. In the present embodiment, the detection signal generation unit 99 is based on the comparison unit 97 that compares the intensity of the signal output from each of the first light receiving element 131 and the second light receiving element 132 and the detection result of the comparison unit 97. And an output switching unit 98 that switches a signal output as the detection signal Vt among the signals output from the first light receiving element 131 and the second light receiving element 132. Therefore, in this embodiment, the range that is allowed to be input by the position detection unit 50 is set to a value corresponding to the maximum output for one light receiving element 130 used in the light receiving unit 13.

  As shown in FIG. 12B, the comparison unit 95 includes a comparator 971 that compares the intensities of the signals output from the first light receiving element 131 and the second light receiving element 132. The output switching unit 98 is configured by a switch 981 that selects a signal having the maximum intensity among the signals output from each of the first light receiving element 131 and the second light receiving element 132 based on the comparison result by the comparator 971. ing.

  In the optical position detection device 10 configured as described above, when the second light receiving element 132 is selected in the first light emitting / receiving unit 15A based on the light reception result in the initial lighting operation, the first lighting operation (first Period) and the second lighting operation (second period), the signal output from the second light receiving element 132 is amplified and then output to the position detection unit 50 as the detection signal Vt. . When the first light receiving element 131 is selected in the second light emitting / receiving unit 15B based on the light reception result in the initial lighting operation, the first lighting operation (first period) and the second lighting operation (second period) are selected. ), The signal output from the first light receiving element 131 is amplified and then output to the position detection unit 50 as a detection signal Vt.

  The position detection unit 50 detects the position of the target object Ob based on the detection signal Vt output from the detection signal generation unit 99. More specifically, the light source unit 12 is the light source unit 12 when the level of the detection signal Vt during the first period is equal to the level of the detection signal Vt during the second period. The position of the target object Ob is detected based on the drive current value. As shown in FIG. 11B, this operation is sequentially performed in the first light emitting / receiving unit 15A and the second light emitting / receiving unit 15B. As a result, the XY coordinates of the target object Ob are detected.

  As described above, also in this embodiment, as in the first embodiment, reflected light from the target object Ob using the plurality of light receiving elements 130 (the first light receiving element 131 and the second light receiving element 132) as the light receiving element 130. Since L3 is detected, when the reflected light L3 is incident on the first light receiving element 131 from the direction where the light receiving sensitivity is low, the reflected light L3 is incident on the second light receiving element 132 from the direction where the light receiving sensitivity is high. Similarly, when the reflected light L3 enters from the direction where the light receiving sensitivity is low in the second light receiving element 132, the reflected light L3 enters the first light receiving element 131 from the direction where the light receiving sensitivity is high. For this reason, the detection space 10R can be expanded.

  In this embodiment, a signal having a high level is output as the detection signal Vt among the signal output from the first light receiving element 131 and the signal output from the second light receiving element 132, and the position of the target object Ob is determined. To detect. For this reason, since the high-level detection signal Vt is input to the position detection unit 50, the position of the target object Ob can be detected with high accuracy. More specifically, when the detection light L2 is emitted, a part of the detection light L2 reflected by an object other than the target object Ob is incident on the light receiving element 130. Therefore, the detection light L2 is in a direction greatly inclined from the normal direction to the light receiving surface. When the target object Ob is located, the output from the light receiving element 130 increases the ratio of components caused by the detection light reflected by the object other than the target object Ob and incident on the light receiving element 130. However, according to the present embodiment, the ratio of the component due to the detection light L2 reflected by an object other than the target object Ob and incident on the light receiving element 130 is low in the detection signal Vt. Further, since the level of the detection signal Vt obtained during the first period and the second period is high, the detection accuracy is high.

  In addition, the range in which input is allowed in the position detection unit 50 may be set to a value corresponding to the maximum output for one light receiving element 130 used in the light receiving unit 13, so that signal overflow can be avoided. Further, since the input range of the position detection unit 50 can be set low, the position of the target object Ob can be detected with high accuracy even if the detection signal Vt is at a relatively low level.

  Further, after selecting one light receiving element from the first light receiving element 131 and the second light receiving element 132, processing of the signal output from the other light receiving element can be stopped, so that power saving and processing time can be reduced. Shortening can be achieved.

[Modification of Embodiment 2]
In the above embodiment, one light receiving element of the first light receiving element 131 and the second light receiving element 132 is selected based on the light reception result in the initial lighting operation, but the first lighting operation (first period) and the second light receiving element are selected. One light receiving element of the first light receiving element 131 and the second light receiving element 132 may be selected based on the light receiving result in the lighting operation (second period).

[Forms of other embodiments]
In the above embodiment, two light source units (the first light source unit 12A and the second light source unit 12B) are used. However, the position of the target object Ob may be detected using one light source unit 12. Moreover, in the said embodiment, although the light-receiving part 13 was provided in the radiation | emission center position of the detection light L2, you may provide the light-receiving part 13 in another location, Two light source parts (1st light source part 12A and 2nd light source part). A common light receiving unit 13 may be provided for the light source unit 12B). Furthermore, in the above example, the light receiving unit 13 includes two light receiving elements (the first light receiving element 131 and the second light receiving element 132), but may include three or more light receiving elements.

  In the above embodiment, the light source 120 is provided in each of the two light guides LG. However, the light sources 120 are provided at both ends of the one light guide LG, and the light sources 120 are alternately turned on, so that In the two periods, light intensity distributions in opposite directions may be formed. In this case, if the light receiving unit 13 is provided at the radiation center of the light source unit 12, the light source unit 12 prevents the detection light L <b> 2 from entering the light receiving unit 13. It can be arranged at a position shifted from the center in the Z-axis direction.

  In the above embodiment, the first light source module 126 and the second light source module 127 use the light guide LG to detect light having a light intensity distribution whose intensity changes from one side to the other side within the emission range. Although L2 is emitted, the first light source module 126 and the second light source module 127 are provided with a plurality of light emitting elements, and the light source driving unit 51 supplies a driving current to each light emitting element in one of the arrangement directions of the plurality of light emitting elements. Employing one that emits detection light L2 having a light intensity distribution whose intensity changes from one side to the other side within the emission range by decreasing from the light emitting element at the end toward the light emitting element at the other end. You can also.

[Configuration example of position detection system]
(Specific example 1 of a position detection system)
FIG. 13 is an explanatory diagram of a specific example 1 (display system with an input function) of the position detection system 1 to which the present invention is applied. In the display system with an input function of the present embodiment, the configurations of the position detection system 1 and the optical position detection device 10 are the same as the configurations described with reference to FIGS. The same reference numerals are used for illustration, and descriptions thereof are omitted.

  In the position detection system 1 according to the above embodiment, as shown in FIG. 13, an image display device 110 is used as the viewing surface constituting member 40, and the image display device 110 will be described with reference to FIGS. 1 to 12. If the optical position detection device 10 is provided, it can be used as a display system 100 with an input function such as an electronic blackboard or digital signage. Here, the image display device 110 is a direct-view image display device or a rear projection-type image display device using the viewing surface constituent member 40 as a screen.

  In the display system 100 with an input function, the optical position detection device 10 emits the detection light L2 along the display surface 110a (viewing surface 41) of the image display device 110, and also detects the detection light L2 reflected by the target object Ob. (Reflected light L3) is detected. For this reason, if the target object Ob is brought close to a part of the image displayed on the image display device 110, the position of the target object Ob can be detected. Can be used as input information.

(Specific example 2 of the position detection system)
With reference to FIG. 14, the example which comprised the projection type display system with a position function using a screen as the visual recognition surface structural member 40 is demonstrated. FIG. 14 is an explanatory diagram of a specific example 2 (display system with an input function / projection type display system with an input function) of the position detection system 1 to which the present invention is applied. In the projection display system with a position function of this embodiment, the configurations of the position detection system 1 and the optical position detection device 10 are the same as the configurations described with reference to FIGS. Are denoted by the same reference numerals, and description thereof is omitted.

  In the projection display system 200 with an input function shown in FIG. 14 (display system with an input function), an image projection apparatus 250 (image generation apparatus) called a liquid crystal projector or a digital micromirror device is used as a screen 80 (viewing surface constituent member). 40) An image is projected. In the projection display system 200 with an input function, the image projection device 250 enlarges and projects the image display light Pi from the projection lens system 210 provided in the housing 240 toward the screen 80. Here, the image projection device 250 projects the image display light Pi toward the screen 80 from a direction slightly inclined with respect to the Y-axis direction. Therefore, the screen surface 80a on which an image is projected on the screen 80 constitutes a viewing surface 41 on which information is visually recognized.

  In the projection display system 200 with an input function, the optical position detection device 10 is added to the image projection device 250 and configured integrally. For this reason, the optical position detection device 10 emits the detection light L2 along the screen surface 80a from a location different from the projection lens system 210, and detects the reflected light L3 reflected by the target object Ob. For this reason, if the target object Ob is brought close to a part of the image projected on the screen 80, the position of the target object Ob can be detected. Therefore, the position of the target object Ob is input as an image switching instruction or the like. It can be used as information.

  If the optical position detection device 10 and the screen 80 are integrated, a screen device with an input function can be configured.

(Other specific examples of position detection systems)
In the present invention, the viewing surface constituent member 40 can employ a configuration that is a translucent member that covers the exhibit. In this case, the viewing surface 41 is opposite to the side on which the exhibit is arranged in the translucent member. This is the surface on which the exhibits can be seen. According to such a configuration, a window system with an input function can be configured.

  Further, the viewing surface constituting member 40 can adopt a configuration that is a base that supports a moving game medium. In this case, the visual recognition surface 41 is such that the relative position between the base and the game medium is visually recognized on the base. This is the surface on the other side. According to this configuration, an amusement device such as a pachinko machine or a coin game can be configured as an amusement system with an input function.

DESCRIPTION OF SYMBOLS 1 ... Position detection system 10 ... Optical position detection device 12 ... Light source part, 12A ... First light source part, 12B ... Second light source part, 13 ... Light receiving part, 13A ... First light reception , 13B... Second light receiving unit, 15... Light receiving and emitting unit, 15A... First light emitting and receiving unit, 15B .. second light emitting and receiving unit, 40. ..Light source drive unit, 71..Signal processing unit, 80..Screen, 93..Addition unit, 94..Addition output amplification unit, 95, 97..Comparison unit, 96..Amplification factor switching unit, 96 ' ..Current limiting resistance switching unit, 98 ..Output switching unit, 100 ..Display system with input function, 131 ..First light receiving element, 132 ..Second light receiving element, 200 ..Projection type display system with input function

Claims (10)

A light source that emits detection light;
A light receiving unit comprising a plurality of light receiving elements for receiving the detection light reflected in the space from which the detection light is emitted;
The addition output obtained by adding a plurality of signals output from each of the plurality of light receiving elements is compared with a threshold value. When the addition output is equal to or less than the threshold value, a signal having a level obtained by multiplying the addition output by the first magnification is detected. A detection signal generation unit that outputs a signal having a level obtained by multiplying the addition output by a second magnification smaller than the first magnification when the addition output exceeds the threshold;
A position detector that detects the position of the target object in the space based on the detection signal;
An optical position detection device characterized by comprising: The detection signal generation unit includes a comparison unit that compares the addition output and the threshold value, an addition output amplification unit that amplifies the addition output and outputs the detection signal, and a comparison result of the comparison unit. When the added output is less than or equal to the threshold, the gain of the added output amplifying unit is set as a first gain, and when the added output exceeds the threshold, the gain of the added output amplifying unit is smaller than the first gain. An amplification factor switching unit as a second amplification factor;
The optical position detection device according to claim 1, comprising:   The detection signal generation unit includes a comparison unit that compares the addition output and the threshold value, and a comparison result of the comparison unit indicates that a current limiting resistor having a first resistance value is obtained when the addition output is equal to or less than the threshold value. The detection signal is output through the addition output, and when the addition output exceeds the threshold value, the detection signal is output through the addition output to a current limiting resistor having a second resistance value larger than the first resistance value. The optical position detection device according to claim 1, further comprising: a current limiting resistance switching unit. A light source that emits detection light;
A light receiving unit comprising a plurality of light receiving elements for receiving the detection light reflected in the space from which the detection light is emitted;
A signal generator for detection that compares the intensities of a plurality of signals output from each of the plurality of light receiving elements, and outputs a signal having the maximum intensity among the plurality of signals as a signal for detection;
A position detector that detects the position of the target object in the space based on the detection signal;
An optical position detection device characterized by comprising:   The optical type according to claim 4, wherein a range that is allowed to be input by the position detection unit is set to a value corresponding to a maximum output of one light receiving element used in the light receiving unit. Position detection device. The light source unit emits detection light so as to form a light intensity distribution in which the intensity decreases from one side to the other side in the space during the first period, and the second period does not overlap with the first period. Medium, emitting detection light in the space so as to form a light intensity distribution in which the intensity decreases from the other side toward the one side,
The position detection unit is based on a drive current value in the light source unit when the level of the detection signal during the first period is equal to the level of the detection signal during the second period. The optical position detection apparatus according to claim 1, wherein the position of the target object is detected. The plurality of light receiving elements include a first light receiving element and a second light receiving element disposed at a position adjacent to the first light receiving element,
The optical position according to claim 1, wherein the first light receiving element and the second light receiving element extend in directions in which normal directions with respect to the light receiving surface intersect each other. Detection device.   The normal direction of the first light receiving element and the normal direction of the second light receiving element extend in directions that form an angle of 45 ° to 90 ° with each other. Optical position detection device. A display system with an input function, comprising: the optical position detection device according to any one of claims 1 to 8; and a display device including a display surface on which an image is displayed.
The display system with an input function, wherein the display device switches the image based on a position of the target object in a direction along the display surface detected by the optical position detection device. A display system with an input function, comprising: the optical position detection device according to any one of claims 1 to 8; and an image projection device that projects an image.
The display system with an input function, wherein the image projection device switches the image based on a position of the target object in a direction intersecting a projection direction of the image detected by the optical position detection device.