JP2012194914A - Position detection device, display system with input function, and position detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detection device capable of preventing a detection error from occurring owing to incidence of detection light onto a light reception part after reflection by a body other than an object, a display system with an input function, and a position detection method.SOLUTION: In a position detection device 10, a light reception part 13 receives detection light L2 reflected by an object Ob, and also receives detection light (stray light L5) generated as the detection light L2 is reflected by a body Sb other than the object. Here, the intensity of the stray light L5 is in proportion to the intensity of the detection light L2. For the purpose, a compensation light source part 14 which emits compensation light L4 to enter the light reception part 13 not through a detection object space 10R is provided to decrease the intensity of the compensation light L4 when the intensity of the detection light L2 is increased and to increase the intensity of the compensation light L4 when the intensity of the detection light L2 is decreased.

Description

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

  As a position detection device that optically detects a target object, for example, 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 transparent member. In this case, there has been proposed one in which detection light reflected by a target object is transmitted through a translucent member and detected by a light receiving unit (see Patent Document 1). There has also been proposed a position detection device of a type 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 (Patent Document). 2 and 3).

  In such a position detection device, the received light intensity at the light receiving unit when some of the point light sources are turned on, and the received light intensity at the light receiving unit when some other point light sources are turned on, Based on the comparison result, the position of the target object is detected.

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

  In the position detection devices described in Patent Documents 1 to 3, the light reception intensity at the light receiving unit when some of the point light sources are turned on in the first period and the other part in the second period. The first drive current value supplied to some of the point light sources and the second drive current supplied to some of the other point light sources so that the received light intensity at the light receiving unit when the point light sources are turned on are equal. By adjusting the value and detecting the position of the target object based on the comparison result between the first drive current value and the second drive current value after adjustment, the influence of external light or the like can be eliminated.

  However, in the configurations described in Patent Documents 1 to 3, detection is performed when the detection light emitted from the point light source is reflected by an object other than the target object such as fixtures placed around and incident on the light receiving unit. There is a problem that the error is large.

  Such a problem will be described with reference to FIG. First, in a period T11 shown in FIG. 16, the first drive current value supplied in the first period is made equal to the second drive current value supplied in the second period in a state where the target object does not exist in the detection target space. If some point light sources and some other point light sources are turned on sequentially in the first period and the second period, the intensity of the detection light (reflected light) reflected by the target object is zero. Detection light reflected by an object other than the target object enters the light receiving unit as stray light. Next, when the target object appears in the detection target space in the period T12, the light receiving unit receives reflected light and stray light reflected by the target object. Here, when the received light intensity at the light receiving unit is the same in the first period and the second period, it can be understood that the target object is at the center position. On the other hand, when the received light intensity at the light receiving unit is different between the first period and the second period as in the period T13, the received light intensity at the light receiving unit is the first period and the second period as in the period T14. The first drive current value supplied in the first period and the second drive current value supplied in the second period are adjusted so as to be equal to each other. When the received light intensity at the light receiving unit becomes equal between the first period and the second period, the difference or ratio between the adjustment amount ΔI11 for the first drive current value and the adjustment amount ΔI12 for the second drive current value is used. For example, the position of the target object should be detectable.

  However, the light receiving unit receives the detection light reflected by the target object and also receives the stray light reflected by the object other than the target object. Here, since the intensity of the stray light is proportional to the emission intensity of the detection light, adjusting the first drive current value and the second drive current value also changes the stray light intensity. As a result, as shown in the period T14, the first period and the second period are actually different in the light reception intensity with respect to the detection light reflected by the target object in the first period and the second period. , The received light intensity at the light receiving section becomes equal, and a detection error occurs.

  In view of the above problems, an object of the present invention is to provide a position detection device that can prevent detection errors caused by detection light reflected off an object other than a target object and incident on a light receiving unit, An object is to provide a display system with an input function including a position detection device, and a position detection method.

  In order to solve the above problems, the present invention provides a position detection device that optically detects the position of a target object, the first detection light forming a first light intensity distribution, and the first light intensity distribution; Reflected by the detection light source unit that emits the second detection light that forms a different second light intensity distribution, and the target object that is located in the space in which the first light intensity distribution and the second light intensity distribution are formed A light receiving unit that receives reflected light of the first detection light and the second detection light, and compensation light that is incident on the light receiving unit without passing through the space in which the first light intensity distribution and the second light intensity distribution are formed. And a first driving current value, second detection light, and compensation light that are supplied to the detection light source in a first period of emitting the first detection light and the compensation light. In the second period, the detection light source unit A light source driving unit that increases or decreases a second driving current value to be supplied and a third driving current value to be supplied to the compensation light source unit, and a light receiving intensity of the light receiving unit in the first period and the light receiving in the second period. A position detection unit that detects the position of the target object based on the first drive current value and the second drive current value when the received light intensity at the unit becomes equal, the light source drive unit When the first drive current value is increased, the third drive current value is decreased. When the first drive current value is decreased, the third drive current value is increased, and the second drive current value is increased. The third drive current value is sometimes reduced, and when the second drive current value is reduced, the third drive current value is increased.

  In the present invention, in the first period, the detection light source unit is driven with the first drive current value to form the first light intensity distribution, and the light reception intensity of the light reception unit in the first period and the detection light source unit are driven second. The position of the target object is determined based on the first drive current value and the second drive current value at the time when the received light intensity of the light receiving unit in the second period in which the second light intensity distribution is formed by driving with the current value becomes equal. To detect. At the time of such position detection, the light receiving unit receives the detection light reflected by the target object and also receives the detection light (stray light) reflected by the fixture or the like. Here, since the intensity of stray light is proportional to the intensity of light emitted from the light source, adjusting the first drive current value and the second drive current value also changes the intensity of the stray light. A compensation light source unit that emits compensation light incident on the light receiving unit without passing through the space in which the intensity distribution and the second light intensity distribution are formed is provided, and supplied to the compensation light source unit when the first drive current value is increased. The third drive current value is decreased, and when the first drive current value is reduced, the third drive current value is increased. Further, when the second drive current value is increased, the third drive current value is decreased, and when the second drive current value is decreased, the third drive current value is increased. Accordingly, the intensity change of the received light intensity of the stray light when the first drive current value and the second drive current value are adjusted can be corrected by the intensity change of the received light intensity of the compensation light. Accordingly, it is possible to prevent occurrence of a detection error due to the detection light being reflected by an object other than the target object and entering the light receiving unit.

  In the present invention, the light source driving unit sets the first driving current value and the second driving current value to an initial current value and emits the first detection light and the second detection light, and then The first drive current value and the second drive current value are increased / decreased based on a light reception result at the light receiving unit, and the position detection unit is configured to detect the light reception intensity of the light receiving unit in the first period and the second period. The target object based on the difference between the first drive current value and the initial current value when the received light intensity at the light receiving unit becomes equal, and the difference between the second drive current value and the initial current value It is possible to adopt a configuration for detecting the position of. According to this configuration, it is possible to prevent the influence of ambient light such as outside light.

  In the present invention, it is preferable that the detection light source unit includes a first detection light source that emits the first detection light and a second detection light source that emits the second detection light.

  In this case, the light source driving unit drives the first detection light source and the second detection light source by voltage amplitude modulation, and is supplied to the constant voltage and the first detection light source in the first period. A voltage corresponding to a difference from a voltage is applied to the compensation light source unit, and a voltage corresponding to a difference between a constant voltage and a driving voltage supplied to the second detection light source is applied to the compensation light source in the second period. A configuration applied to the light source unit can be employed.

  In the present invention, the light source driving unit drives the first detection light source and the second detection light source by pulse width modulation, and supplies the first detection light source to the first detection light source in the first period. A drive pulse complementary to the pulse is supplied to the compensation light source unit, and a drive pulse complementary to the drive pulse supplied to the second detection light source is supplied to the compensation in the second period. You may employ | adopt the structure supplied to a light source part.

  In the present invention, in the state where the target object does not exist in the space where the first light intensity distribution and the second light intensity distribution are formed, the first drive current value is set to an initial current value, and the detection light source The received light intensity at the light receiving unit when the light source unit is driven, and the received light intensity at the light receiving unit when the light source unit for detection is driven by increasing or decreasing the first drive current value from the initial current value. Equally, by setting the second driving current value to the initial current value and driving the detection light source unit, the light receiving intensity at the light receiving unit and the second driving current value are increased or decreased from the initial current value. It is preferable that the received light intensity in the light receiving unit when the detection light source unit is driven is equal.

  With this configuration, in the state where the target object does not exist in the space where the first light intensity distribution and the second light intensity distribution are formed, the light receiving intensity of the first detection light in the light receiving unit and the light receiving unit Is obtained by adopting a configuration equal to the sum of the received light intensity of the second detection light at the light receiving unit and the received light intensity of the compensation light at the light receiving unit. be able to.

  The position detection apparatus according to the present invention can be used in various systems such as a display system with an input function. For example, as a display system with an input function including a position detection device to which the present invention is applied, a display device including a display surface on which an image is displayed is provided, and the position detection result of the target object is detected by the position detection device. Based on this, it is possible to exemplify a display system with an input function in which an image displayed on the display surface in the display device is switched. In addition, the display system with an input function including the position detection device to which the present invention is applied includes an image projection device that projects an image, and the image projection is performed based on the position detection result of the target object in the position detection device. A display system with an input function in which an image projected from the apparatus can be switched can be exemplified.

  Further, the present invention is a position detection method for optically detecting the position of a target object, wherein the first light intensity distribution is formed by emitting the first detection light from the light source unit for detection in the first period and is compensated. A first light emitting step of emitting compensation light incident on the light receiving unit without passing through the space in which the first light intensity distribution is formed from the light source unit for use, and second detection light from the light source unit for detection in the second period Is emitted to form a second light intensity distribution and the compensation light is emitted from the compensation light source unit, and a first drive current value supplied to the detection light source unit in the first period A current increase / decrease step for increasing / decreasing a second drive current value supplied to the detection light source unit in the second period and a third drive current value supplied to the compensation light source unit; and the light reception in the first period Received light intensity at the light receiving portion and light receiving at the light receiving portion during the second period. The position of the target object located in the space where the first light intensity distribution and the second light intensity distribution are formed based on the first drive current value and the second drive current value when the intensity becomes equal In the current increase / decrease step, the third drive current value is reduced when the first drive current value is increased, and the first drive current value is reduced when the first drive current value is reduced. The third drive current value is increased, the third drive current value is decreased when the second drive current value is increased, and the third drive current value is increased when the second drive current value is decreased. And

  In the present invention, in the first period, the detection light source unit is driven with the first drive current value to form the first light intensity distribution, and the light reception intensity of the light reception unit in the first period and the detection light source unit are driven second. The position of the target object is determined based on the first drive current value and the second drive current value at the time when the received light intensity of the light receiving unit in the second period in which the second light intensity distribution is formed by driving with the current value becomes equal. To detect. At the time of such position detection, the light receiving unit receives the detection light reflected by the target object and also receives the detection light (stray light) reflected by the fixture or the like. Here, since the intensity of stray light is proportional to the intensity of light emitted from the light source, adjusting the first drive current value and the second drive current value also changes the intensity of the stray light. A compensation light source unit that emits compensation light incident on the light receiving unit without passing through the space in which the intensity distribution and the second light intensity distribution are formed is provided, and supplied to the compensation light source unit when the first drive current value is increased. The third drive current value is decreased, and when the first drive current value is reduced, the third drive current value is increased. Further, when the second drive current value is increased, the third drive current value is decreased, and when the second drive current value is decreased, the third drive current value is increased. Accordingly, the intensity change of the received light intensity of the stray light when the first drive current value and the second drive current value are adjusted can be corrected by the intensity change of the received light intensity of the compensation light. Accordingly, it is possible to prevent occurrence of a detection error due to the detection light being reflected by an object other than the target object and entering the light receiving unit.

It is explanatory drawing which shows typically the principal part of the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the light emitting / receiving unit of the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the principal part of the light emitting / receiving unit shown in FIG. It is explanatory drawing which shows typically the structure of the light source part comprised in the light emitting / receiving unit shown in FIG. It is explanatory drawing which shows the electrical structure etc. of the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the position detection principle in the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the principle which acquires the XY coordinate data of a target object in the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the light source circuit provided in the light source drive part of the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the principle of the stray light compensation in the position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the light source circuit provided in the light source drive part of the position detection apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the light emitting / receiving unit of the position detection apparatus which concerns on Embodiment 3 of this invention. It is explanatory drawing of the light source part in the light emitting / receiving unit shown in FIG. It is explanatory drawing which shows the electrical structure etc. of the position detection apparatus which concerns on Embodiment 3 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 which shows the problem of the conventional position detection apparatus.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying 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 schematically showing the main part of a position detection device according to Embodiment 1 of the present invention. FIGS. 1 (a) and 1 (b) show the position detection device on the detection light emission space side. It is explanatory drawing when it sees from the diagonal direction, and explanatory drawing when a position detection apparatus is seen from the front.

  In FIG. 1, the position detection system 1 of the present embodiment includes a position detection device 10 that detects the position of the target object Ob. The position detection device 10 is a virtual that is defined by the X-axis direction and the Y-axis direction. The position of the target object Ob is detected using the detection light L2 emitted radially along the XY plane (virtual plane). In the present embodiment, the position detection system 1 includes a viewing surface constituent member 40 provided with a viewing surface 41 that extends along the XY plane on one side Z1 in the Z-axis direction, and the position detection device 10 includes the viewing surface 41. The detection light L <b> 2 is emitted along and the position of the target object Ob located on the viewing surface 41 side (one side Z <b> 1 in the Z-axis direction) with respect to the viewing surface constituent member 40 is detected. Accordingly, the detection target space 10R of the position detection system 1 is a detection light emission space from which the detection light L2 is emitted in the position detection device 10, and a light intensity distribution of the detection light L2 described later is formed in the detection target 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 position detection device 10.

  In the position detection system 1 of the present embodiment, the position detection device 10 includes a detection light source unit 12 (linear light source unit) that radiates detection light L2 radially along the viewing surface 41 (XY plane), and 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 in the emission space (detection target space 10R).

  In this embodiment, as the detection light source unit 12, two detection light source units 12 (first detection use) that face the detection target space 10R at positions separated from the viewing surface constituent member 40 on one side Y1 in the Y-axis direction. The first light source unit 12A and the second light source unit 12B are spaced apart in the X-axis direction and the same position in the Y-axis direction. It is in. Further, in the present embodiment, as the light receiving unit 13, the first light receiving unit 13A and the second light receiving unit 13B facing the detection target space 10R at positions separated from the viewing surface constituent member 40 on the one side Y1 in the Y axis direction. 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, the first light receiving unit 13A is disposed at the radiation center position of the detection light L2 (detection light L2a) emitted radially from the first light source unit 12A for detection, and the first light receiving unit 13A and the first detection unit 13A. The light source unit 12A is integrated as a first light emitting / receiving unit 15A. In addition, 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 for detection, and is connected to the second light receiving unit 13B and the second detection light. The light source unit 12B is integrated as a second light emitting / receiving unit 15B.

  As will be described later, each of the two detection light source units 12 (the first detection light source unit 12A and the second detection light source unit 12B) is a detection light source (point light source) composed of a light emitting element such as an LED (light emitting diode). The detection light source emits detection light L2 (detection light L2a, L2b) made of infrared light having a peak wavelength of 840 to 1000 nm as diverging light. Each of the light receiving sections 13 (first light receiving section 13A and second light receiving section 13B) includes a light receiving element 130 such as a photodiode or a phototransistor. In this embodiment, the light receiving element 130 has a sensitivity peak in the infrared region. It is a photodiode.

  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. Therefore, 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 by the target object Ob located in the detection target space 10R. (Reflected light L3) is received. When the detection light L2b is emitted from the second detection light source unit 12B in the second light emitting / receiving unit 15B in a period different from the operation, the second light receiving unit 13B is configured to detect the target object Ob located in the detection target space 10R. The detection light L2b (reflected light L3) reflected by is received.

  In the position detection device 10 of the present embodiment, when the detection light L2 is emitted from the detection light source unit 12 (the first detection light source unit 12A and the second detection light source unit 12B), the object Sb other than the target object such as fixtures The detection light reflected by the light enters the light receiving unit 13 (the first light receiving unit 13A and the second light receiving unit 13B) as stray light L5. Therefore, as will be described in detail later, the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B are provided with a compensation light source unit 14 (first compensation light source unit 14A and second compensation light source unit 14B). ing.

(Specific Configuration of Detection Light Source 12)
FIG. 2 is an explanatory diagram of the light emitting / receiving unit of the position detection device 10 according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram showing a configuration of a main part of the light emitting / receiving unit shown in FIG. FIG. 4 is an explanatory diagram schematically showing the configuration of the light source unit for detection 12 configured in the light receiving and emitting unit shown in FIG. 3, and the detection light L2 (first detection light L2s) during the first lighting operation in the first period. It is explanatory drawing which shows a mode that light is emitted, and explanatory drawing which shows a mode that detection light L2 (2nd detection light L2t) is radiate | emitted at the time of the 2nd lighting operation of a 2nd period.

  As shown in FIG. 2, in the position detection device 10 of the present embodiment, the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B have the same configuration, and therefore the first detection light source unit 12A and The second light source unit 12B for detection also has the same configuration. More specifically, the first light emitting / receiving unit 15A includes a light source support member 150 having a fan shape or a semicircular shape when viewed from the Z-axis direction. The light source support member 150 has a structure in which a first light source support member 151 and a second light source support member 152 are stacked in the Z-axis direction, and each of the first light source support member 151 and the second light source support member 152 has a structure. The fan-shaped or semi-circular flanges 156a and 156b are provided. The portion sandwiched between the flange portions 156a and 156b is an emission portion from which the detection light L2 is emitted from the first detection light source portion 12A, and the flange portions 156a and 156b emit the detection light L2 in the Z-axis direction. The range is limited.

  In the first light receiving and emitting unit 15A, the first light source unit 12A for detection includes a first light source module 126 and a second light source module 127 that are arranged to overlap in the Z-axis direction as the output part of the detection light L2. . In the first detection 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 a light-transmitting light guide unit 128. The light receiving element 130 of the first light receiving unit 13A is disposed in the back. Since the second light emitting / receiving unit 15B also has the same configuration as the first light emitting / receiving unit 15A, description thereof is omitted.

  As shown in FIG. 3, 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 for detection 120 including a light emitting element such as a light emitting diode, and an arc-shaped light guide LG. It has. 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 detection light source 120 including a light emitting element such as a light emitting diode, and an arc-shaped light source. A light guide LG is provided.

  As shown in FIG. 4, the first light source module 126 includes a first light source for detection 121 made of a light emitting element such as a light emitting diode that emits infrared light as the light source for detection 120, and an arc-shaped light. A guide LG is provided, and the first detection light source 121 is disposed at one end LG1 of the light guide LG. The first light source module 126 includes an arc-shaped irradiation direction setting unit LE including the optical sheet PS, the louver film LF, and the like 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. Similarly to the first light source module 126, the second light source module 127 includes a second light source for detection 122 made of a light emitting element such as a light emitting diode that emits infrared light as the light source for detection 120. The light guide LG is provided, and the second light source for detection 122 is disposed at the other end LG2 of the light guide LG. Similarly to the first light source module 126, the second light source module 127 also has an arcuate irradiation direction setting unit 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. Note that at least one of the outer peripheral surface LG3 and the inner peripheral surface LG4 of the light guide LG is subjected to processing for adjusting the emission efficiency of the detection light L2 from the light guide LG. For example, it is possible to employ a method of printing reflective dots, a molding method of attaching irregularities by a stamper or injection, or a groove processing method. Since the second light emitting / receiving unit 15B also has the same configuration as the first light emitting / receiving unit 15A, description thereof is omitted.

(Configuration of compensation light source unit 14)
In the position detecting device 10 configured as described above, the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B each include the first compensating light source unit 14A and the second compensating light source unit 14B as the compensating light source unit 14, respectively. I have. The compensation light source unit 14 includes, for example, a point light source such as a light-emitting diode having an emission optical axis directed to the other side Y2 in the Y-axis direction and the one side Y1 with respect to the light receiving unit 13, and is emitted from the compensation light source unit 14. The compensation light L4 enters the light receiving unit 13 without passing through the detection target space 10R.

(Configuration of position detector, etc.)
FIG. 5 is an explanatory diagram illustrating an electrical configuration and the like of the position detection device 10 according to the first embodiment of the present invention, and FIGS. 5A and 5B are explanatory diagrams illustrating a configuration of a control IC. It is explanatory drawing of the drive signal supplied to a light source.

  In the position detection apparatus 10 used in the position detection system 1 of the present embodiment, the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B described with reference to FIGS. It is electrically connected to the control IC 70. Here, the control IC 70 includes a first control IC 70A electrically connected to the first light emitting / receiving unit 15A and a second control IC 70B electrically connected to the second light receiving / emitting unit 15B. The first detection light source unit 12A and the first light receiving unit 13A of the first light receiving and emitting unit 15A are electrically connected to the first control IC 70A. The second light source unit 12B for detection and the second light receiver unit 13B of the second light emitting / receiving unit 15B are electrically connected to the second control IC 70B.

  The first control IC 70A and the second control IC 70B have the same configuration, and both are electrically connected to the common control device 60. First, the first control IC 70A 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 first control IC 70A 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, a pulse And a switch unit 76 that controls which of the first detection light source 121 and the second detection light source 122 of the first detection light source unit 12A is applied with the drive pulse generated by the generator 75a and the pulse generator 75b. is doing. The pulse generators 75a and 75b and the switch unit 76 constitute a light source driving unit 51 together with a light source circuit 780 to be described later with reference to FIG. 8, and the first control IC 70A is connected via the light source circuit 780. A driving current is supplied to the first detection light source 121 and the second detection light source 122 of the detection light source unit 12 (first detection light source unit 12A), and the compensation light source unit 14 (first compensation light source unit 14A). Also supplies drive current.

  Further, the first control IC 70A includes a received light amount measuring unit 73 including an amplifying unit that amplifies the detection result of the first light receiving unit 13A, and a pulse generator 75a based on the measurement result of the received light amount measuring unit 73. , 75b to control the drive current value (first drive current value) of the drive pulse supplied to the detection light source 120 (the first detection light source 121 and the second detection light source 122) of the first detection light source unit 12A. And an adjustment amount calculation unit 74 for adjustment. 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.

  Similarly to the first control IC 70A, the second control IC 70B also has pulse generators 75a and 75b and a switch unit 76 that constitute the light source drive unit 51 together with the light source circuit 780. Similarly to the first control IC 70A, the second control IC 70B has a light reception amount measurement unit 73 including an amplification unit that amplifies the detection result of the second light reception unit 13B, and a measurement by the light reception amount measurement unit 73. Based on the results, the pulse generators 75a and 75b are controlled to supply the second drive current value to be supplied to the detection light source 120 (the first detection light source 121 and the second detection light source 122) of the second detection light source unit 12B. An adjustment amount calculation unit 74 for adjustment 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 first control IC 70 </ b> A and the second control IC 70 </ b> B are controlled by a control unit 61 of a higher-level control device 60 such as a personal computer. The control device 60 includes a received light amount measurement unit 73 and an adjustment amount calculation unit 74. A coordinate data acquisition unit 55 constituting the position detection unit 50 is included. Therefore, in this embodiment, the position detection unit 50 includes the received light amount measurement unit 73 and the adjustment amount calculation unit 74 of the control IC 70 (first control IC 70A and second control IC 70B), and the upper control device 60 (personal computer). ) Coordinate data acquisition unit 55.

  In this embodiment, the detection light source unit 12 includes a first detection light source unit 12A and a second detection light source unit 12B which are arranged at positions separated from each other. Therefore, the coordinate data acquisition unit 55 detects the angular position of the target object Ob with respect to the radiation center of the first detection light source unit 12A based on the driving result for the first detection light source unit 12A. And 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 detection light source unit 12B based on the driving result for the second detection light source unit 12B. In addition, the coordinate data acquisition unit 55 performs object detection 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 object Ob.

  In this embodiment, the two control ICs 70 (first control IC 70A and second control IC 70B) are used in a one-to-one relationship with the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B. The control IC 70 may be multi-channeled, and the first light receiving / emitting unit 15A and the second light receiving / emitting unit 15B may be driven by one control IC 70.

  In the position detection device 10 configured as described above, the light source driving unit 51 provided for the first light source unit for detection 12A is in the first period (during the first lighting operation) as shown in FIG. A drive pulse is applied to the first detection light source 121 of the first detection light source unit 12A, and the second detection light source 122 of the first detection light source unit 12A has a second pulse during the second period (during the second lighting operation). 1 A drive pulse having a phase opposite to that of the drive pulse applied to the detection light source 121 is applied. In the meantime, the first light receiving unit 13A receives the detection light L2a and the like reflected by the target object Ob. Thereafter, the light source drive unit 51 provided for the second detection light source unit 12B sends a drive pulse to the first detection light source 121 of the second detection light source unit 12B in the first period (during the first lighting operation). During the second period (during the second lighting operation), a drive pulse having a phase opposite to that of the drive pulse applied to the first detection light source 121 is applied to the second detection light source 122 of the second detection light source unit 12B. To do. Meanwhile, the second light receiving unit 13B receives the detection light L2b and the like reflected by the target object Ob.

  In the position detection device 10 of this embodiment, voltage amplitude modulation is performed when controlling the drive current value for the light source unit 12 for detection. Note that, as described in the second embodiment, pulse width modulation may be performed in controlling the drive current value for the detection light source unit 12.

(Coordinate detection principle)
As shown in FIG. 4, in the position detection device 10 of the present embodiment, the light source driving unit 51 described with reference to FIG. 5A is the detection light source unit 12 (the first detection light source unit 12 </ b> A and the second detection light source unit 12 </ b> A). In any of the light source units 12B), the first lighting operation (first period) in which the emission intensity of the detection light L2 decreases from one side to the other side of the radiation angle range of the detection light L2, and the detection light L2 A second lighting operation (second period) in which the emission intensity decreases from the other side of the radiation angle range of the detection light L2 toward the one side is performed.

  More specifically, the light source driving unit 51 turns on the first detection light source 121 of the first light source module 126 during the first lighting operation (first period) with respect to the first detection light source unit 12A. The detection light L2 (detection light L2a / first detection light L2s) is emitted to the detection target space 10R. At that time, the second light source 122 for detection is in an extinguished state. As a result, the first light intensity distribution LID1 is formed in the detection target space 10R. The first light intensity distribution LID1 has an angular direction corresponding to one end LG2 from an angular direction corresponding to one end LG1, as shown by the length of the arrow in FIG. 4A. It is an intensity distribution in which the intensity decreases monotonously toward the point.

  In addition, the light source driving unit 51 turns on the second light source 122 for detection of the second light source module 127 in the second lighting operation (second period) with respect to the first light source unit 12A for detection. The detection light L2 (detection light L2a / second detection light L2t) is emitted to the space 10R. At that time, the first light source for detection 121 is in a light-off state. As a result, the second light intensity distribution LID2 is formed in the detection target space 10R. The second light intensity distribution LID2 has an angular direction corresponding to the one end LG1 from an angular direction corresponding to the other end LG2, as shown in FIG. 4B by the length of the arrow. It is an intensity distribution in which the intensity decreases monotonously toward the point.

  In the second detection light source unit 12B, the second detection light source 122 of the second light source module 127 is turned on during the first lighting operation when the first detection light source 121 of the first light source module 126 is turned on. Similarly to the first detection light source unit 12A, the detection light L2 (detection light L2b / first detection light L2s, second detection light L2t) is emitted during the lighting operation, and the first light intensity distribution LID1 and the second light intensity are emitted. A distribution LID2 is formed. Therefore, as will be described later, if the first light intensity distribution LID1 and the second light intensity distribution LID2 are used, the distance DS between the center PEs of the first detection light source unit 12A and the second detection light source unit 12B (see FIG. 7). ) Is fixed, the position of the target object Ob can be detected.

(Detection of angular position of target object Ob)
FIGS. 6A and 6B are explanatory diagrams showing the position detection principle in the position detection apparatus 10 according to the first embodiment of the present invention. FIGS. 6A and 6B are explanatory diagrams of the light intensity distribution and the presence of the target object. It is explanatory drawing of the method of acquiring the positional information (azimuth | direction information) to perform. FIG. 7 is an explanatory diagram illustrating the principle of acquiring the XY coordinate data of the target object Ob in the position detection device 10 according to the first embodiment of the present invention.

  First, when the first light intensity distribution LID1 is formed by the first detection light L2s in the first light source module 126 of the first detection light source unit 12A, the irradiation direction of the detection light L2 and the intensity of the detection light L2 are: The linear relationship indicated by the line E1 in FIG. Further, when the second light intensity distribution LID2 is formed by the second detection light L2t in the second light source module 127 of the first light source unit for detection 12A, the irradiation direction of the detection light L2 and the intensity of the detection light L2 are: The linear relationship indicated by the line E2 in FIG. Here, as shown in FIGS. 6B and 7, in the direction of the angle θ when viewed from the center PE of the first detection light source unit 12A (center of the first light source module 126 / radiation center position of the detection light L2). It is assumed that the target object Ob exists. In this case, when the first light intensity distribution LID1 is formed, the intensity of the detection light L2 (first detection light L2s) at the position where the target object Ob is present is INTs. On the other hand, when the second light intensity distribution LID2 is formed, the intensity of the detection light L2 (second detection light L2t) at the position where the target object Ob is present is INTt. Accordingly, the detection intensity at the first light receiving unit 13A when the first light intensity distribution LID1 is formed is compared with the detection intensity at the first light receiving unit 13A when the second light intensity distribution LID2 is formed. If the relationship between the intensities INTs and INTt is obtained, as shown in FIG. 6B and FIG. 7, the angle θ (angle θ1 / angle) in the direction in which the target object Ob is located with reference to the center PE of the first detection light source unit 12A. Angular position).

  In detecting the angular position (angle θ1) of the target object Ob using this principle, in the present embodiment, the first light intensity distribution LID1 is formed by the first light source module 126 in the first light source unit 12A. The detection intensity at the first light receiving unit 13A at the time and the detection intensity at the first light receiving unit 13A when the second light intensity distribution LID2 is formed by the second light source module 127 are equal to each other. The first drive current value for the light source 121 and the second drive current value for the second detection light source 122 are adjusted. Here, the emission intensity of the detection light L2 from the first detection light source unit 12A is proportional to the first drive current value for the first detection light source 121 and the second drive current value for the second detection light source 122. Therefore, the ratio or difference between the first drive current value after adjusting the first drive current value for the first detection light source 121 and the second drive current value for the second detection light source 122 and the second detection light source 122. Alternatively, 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 when the drive current value is adjusted.

  More specifically, first, the light source driver 51 of the first control IC 70A shown in FIG. 5 turns on the first detection light source 121 as the first lighting operation to form the first light intensity distribution LID1, As the second lighting operation, the second light source for detection 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. The adjustment amount calculation unit 74 of the position detection unit 50 shown in FIG. 5 receives the light reception intensity INTs of the first light receiving unit 13A during the first lighting operation and the light reception intensity INTt of the first light receiving unit 13A during the second lighting operation. And compare. As a result, if the received light intensity INTs of the first light receiving unit 13A during the first lighting operation is equal to the received light intensity INTt of the first light receiving unit 13A during the second lighting operation, the angular position of the target object Ob is 0 °. is there.

  On the other hand, when the received light intensities INTs and INTt are different, the received light intensity INTs of the first light receiving unit 13A during the first lighting operation and the received light intensity INTt of the first light receiving unit 13A during the second lighting operation. Are adjusted so that the first drive current value for the first detection light source 121 and the second drive current value for the second detection light source 122 are equal to each other. Then, when the first lighting operation and the second lighting operation are performed again, the light reception intensity INTs of the first light receiving unit 13A during the first lighting operation and the light reception of the first light receiving unit 13A during the second lighting operation. If the intensity INTt is equal, the first angular position detection unit 551 shown in FIG. 5 performs the first driving current value for the first detection light source 121 after the adjustment and the second angle for the second detection light source 122. The angle θ (angle θ1) in the direction in which the target object Ob is located can be obtained from the ratio or difference between the drive current values or the ratio or difference between the first drive current value and the second detection light source 122. In this embodiment, the received light intensity INTs of the first light receiving unit 13A during the first lighting operation is equal to the received light intensity INTt of the first light receiving unit 13A during the second lighting operation. The angle θ (angle θ1) in the direction in which the target object Ob is located is obtained from the difference between the first drive current value and the adjustment amount when the second drive current value for the second light source for detection 122 is adjusted.

  If such a detection operation is performed also in the second light source unit for detection 12B, the second angular position detection unit 552 shown in FIG. 5 moves in the direction in which the target object Ob is positioned with reference to the center PE of the second light source unit for detection 12B. The angle θ (angle θ2 / angle position) can be obtained. Therefore, the coordinate data determination unit 553 shown in FIG. 5 has the angular position (direction of angle θ1) detected by the first angular position detection unit 551 and the angular position (direction of angle θ2) detected by the second angular position detection unit 552. ) Is obtained as XY coordinate data where the target object Ob is located.

(Configuration of Light Source Circuit 780 for Stray Light Compensation)
FIG. 8 is an explanatory diagram of the light source circuit 780 provided in the light source driving unit 51 of the position detection device 10 according to the first embodiment of the present invention. FIGS. 8A and 8B are circuits of the light source circuit 780. FIG. 4 is an explanatory diagram showing the relationship between the anode voltage applied to the light source unit for detection 12 and the anode voltage applied to the light source unit for compensation 14.

  In the position detection apparatus 10 of the present embodiment, the light source drive unit 51 shown in FIG. 5A performs voltage amplitude modulation when controlling the drive current value for the detection light source unit 12, and The first drive current value supplied to the detection light source 121 and the second drive current value supplied to the second detection light source 122 of the detection light source unit 12 are increased or decreased. In addition, when the light source driving unit 51 supplies a driving current to the first light source for detection 121 in the first period, the light source driving unit 51 also supplies a driving current to the light source for compensation 14 and supplies the second light source for detection 122 in the second period. When supplying the drive current, the drive current is also supplied to the compensation light source unit 14.

  Further, the light source driving unit 51 includes a light source circuit 780, and also increases or decreases the third driving current value supplied to the compensation light source unit. Here, when the light source circuit 780 increases the first drive current value supplied to the first detection light source 121, the light source circuit 780 reduces the third drive current value supplied to the compensation light source unit 14 and sets the first drive current value. When decreasing, the third drive current value is increased. Further, when the light source circuit 780 increases the second drive current value supplied to the second light source 122 for detection, the light source circuit 780 reduces the third drive current value supplied to the compensation light source unit 14 and reduces the second drive current value. When this is done, the third drive current value is increased.

  More specifically, as shown in FIG. 8A, in the light source circuit 780, the terminals 701 and 702 for outputting the drive current in the control IC 70 are the anode terminal of the first detection light source 121 and the second one, respectively. It is connected to the anode terminal of the light source 122 for detection. The anode terminal of the compensation light source unit 14 is connected to a constant potential line 781 that supplies a drive voltage VCC, while the cathode terminal is connected to a switching circuit 782. Based on the signal output from the terminal 703 of the control IC 70, the switching circuit 782 conducts the cathode terminal of the compensation light source unit 14 and the anode terminal of the first detection light source 121 in the first period. In the period, the cathode terminal of the compensation light source unit 14 and the anode terminal of the second detection light source 122 are made conductive. A resistor 783 for adjusting the level of the third drive current value supplied to the compensation light source unit 14 is inserted between the anode terminal of the compensation light source unit 14 and the constant potential line 781.

  According to the light source circuit 780, when the light source driving unit 51 supplies the driving current to the first light source 121 for the first period, the driving current is also supplied to the compensation light source unit 14. Further, as shown in FIG. 8B, when the light source driving unit 51 increases the voltage applied to the first detection light source 121 to increase the first driving current value, the application to the compensation light source unit 14 is performed. The voltage decreases and the third drive current value decreases. In addition, when the light source driving unit 51 decreases the first driving current value by decreasing the voltage applied to the first detection light source 121, the voltage applied to the compensation light source unit 14 increases, resulting in a third driving current value. Will increase.

  Similarly, when the light source driving unit 51 supplies a driving current to the second light source for detection 122 in the second period, the driving current is also supplied to the compensation light source unit 14. Further, as shown in FIG. 8B, when the light source driving unit 51 increases the applied voltage to the second detection light source 122 to increase the second drive current value, the application to the compensation light source unit 14 is performed. The voltage decreases and the third drive current value decreases. Further, when the light source driving unit 51 decreases the voltage applied to the second detection light source 122 to reduce the first driving current value, the voltage applied to the compensation light source unit 14 increases, resulting in a third driving current value. Will increase.

  Here, the level of the third drive current value supplied to the compensation light source unit 14 is set by a resistor 783 inserted between the anode terminal of the compensation light source unit 14 and the constant potential line 781. Accordingly, the first drive current value and the third drive current value are in an inversely proportional or substantially inversely proportional relationship, and the second drive current value and the third drive current value are in an inversely proportional or approximately inversely proportional relationship.

(Compensation principle for stray light)
FIG. 9 is an explanatory diagram illustrating the principle of stray light compensation in the position detection device 10 according to the first embodiment of the present invention. From the upper stage to the lower stage, the first drive current value to the first detection light source 121, The first drive current value to the second detection light source 122, the third drive current value to the compensation light source unit 14 (region with a right-down diagonal line), and the intensity of stray light L5 (region with a right-up diagonal line) ), The received light intensity at the light receiving unit 13 is shown. Here, the intensity of the first detection light L2s emitted from the first detection light source 121 in the first period is proportional to the first drive current value to the first detection light source 121 and in the second period. The intensity of the second detection light L2t emitted from the light source 122 is proportional to the second drive current value to the second detection light source 122, and the intensity of the compensation light L4 emitted from the compensation light source unit 14 is the third drive current. Proportional to value. The stray light L5 is light reflected by the object Sb other than the target object in the detection light L2, and therefore the intensity of the first detection light L2s (first drive current value) and the intensity of the second detection light L2t ( Is proportional to the second drive current value).

  In this embodiment, when the position of the target object Ob is detected based on the principle described with reference to FIGS. 4, 6, 7, etc., the light source drive unit 51 includes the light source circuit 780 described with reference to FIG. 8. As described below with reference to FIG. 9, the stray light L5 reflected by the object Sb other than the target object Ob is received by the detection light L2 (first detection light L2s, second detection light L2t) as described below with reference to FIG. Generation of a detection error due to incidence on the unit 13 is prevented. Such stray light compensation is the same even when either the first detection light source unit 12A or the second detection light source unit 12B is operated.

  First, in the period T1 shown in FIG. 9, in a default state where the target object Ob does not exist in the detection target space 10R, the first drive current value and the third drive current value are set to initial setting values, respectively, and the first detection light source 121 is set. And the light source part 14 for compensation is lighted simultaneously in a 1st period (1st light emission process). Next, in the default state where the target object Ob does not exist in the detection target space 10R, the second drive current value and the third drive current value are set to the initial setting values, respectively, and the second detection light source 122 and the compensation light source 14 are set to the first. Simultaneous lighting in two periods (second light emitting step). As a result, the intensity of the detection light L2 (reflected light L3) reflected by the target object Ob is zero, but the detection light L2 reflected by the object Sb other than the target object such as fixtures enters the light receiving unit 13 as stray light L5. . The compensation light L4 is emitted from the compensation light source unit 14. Accordingly, the light reception intensity at the light receiving unit 13 in the default state is the sum of the light reception intensity of the stray light L5 and the light reception intensity of the compensation light L4.

  Next, when the target object Ob appears in the detection target space 10R in the period T2, the light receiving unit 13 receives the reflected light L3, stray light L5, and compensation light L4 reflected by the target object Ob. Here, when the received light intensity at the light receiving unit 13 is equal between the first period and the second period, it can be understood that the target object Ob is at the center position.

  On the other hand, when the light reception intensity of the light receiving unit 13 is different between the first period and the second period as in the period T3, the light reception intensity at the light receiving unit 13 is the first period and the second period as in the period T4. The first drive current value supplied in the first period and the second drive current value supplied in the second period are adjusted so as to be equal to the period (current increase / decrease step). When the received light intensity at the light receiving unit 13 is equal between the first period and the second period, the difference between the adjustment amount ΔI1 for the first drive current value and the adjustment amount ΔI2 for the second drive current value is used. The position of the target object Ob can be detected. FIG. 9 illustrates a case where the first drive current value is increased and the second drive current value is decreased in the period T4 compared to the period T3.

  During the current increase / decrease process, the intensity of the stray light L5 in the first period and the second period is proportional to the first drive current value and the second drive current value. For this reason, in this embodiment, in the period T4, the intensity of the stray light L5 in the first period is increased, and the intensity of the stray light L5 in the second period is decreased, compared to the period T3. On the other hand, when the drive current value is adjusted, the intensity of the compensation light L4 in the first period and the second period is determined by the light source circuit 780 described with reference to FIG. Increase or decrease in the opposite direction to the value. For example, when the first drive current value increases by 10%, the third drive current value decreases by 10%, and the intensity of the compensation light L4 decreases by 10%. When the second drive current value is reduced by 10%, the third drive current value is increased by 10%, and the intensity of the compensation light L4 is increased by 10%. For this reason, in this embodiment, in the period T4, the intensity of the compensation light L4 in the first period is reduced and the intensity of the compensation light L4 in the second period is increased compared to the period T3.

Accordingly, the intensity of the compensation light L4 changes by the same amount or substantially the same amount as the change amount of the stray light L5. The initial setting value of the third drive current value is an optimal value by a method such as optimizing the resistance value of the resistor 783 based on the detection result in the default state where the target object Ob does not exist in the detection target space 10R. Is set to Therefore, in any period, the light receiving intensity of the compensation light L4 and the light receiving intensity of the stray light L5 in the light receiving unit 13 are expressed as follows: The sum of is constant or substantially constant.

  Therefore, in a state where the target object Ob does not exist in the detection target space 10R, the light reception intensity at the light receiving unit 13 is constant or substantially constant before and after the first drive current value is increased or decreased, and the target object Ob is detected in the detection target space 10R. In the state that does not exist, the light receiving intensity at the light receiving unit 13 is constant or substantially constant before and after the second drive current value is increased or decreased. In other words, in a state where the target object Ob does not exist in the detection target space 10R, the light reception intensity of the first detection light L2s and the light reception intensity of the compensation light L4 before and after the first drive current value is increased or decreased. Is constant or substantially constant, and in the state where the target object Ob does not exist in the detection target space 10R, the received light intensity and compensation of the second detection light L2t at the light receiving unit 13 before and after the second drive current value is increased or decreased. The sum of the received light intensity of the light L4 is constant or substantially constant.

  Therefore, as in the period T4, the first drive current value supplied in the first period and the second period supplied in the second period so that the light reception intensity at the light receiving unit 13 is equal in the first period and the second period. When the two drive current values are adjusted, the intensity of the first detection light L2s reflected by the target object Ob in the first period and incident on the light receiving unit 13 and the intensity reflected by the target object Ob in the second period are reflected on the light receiving unit 13. The intensity of the incident second detection light L2t is constant. Therefore, even if the intensity of the stray light L5 varies as the first drive current value and the second drive current value increase or decrease, the intensity change of the stray light L5 can be absorbed by the increase or decrease of the compensation light L4. Therefore, if the difference between the adjustment amount ΔI1 for the first drive current value and the adjustment amount ΔI2 for the second drive current value is used, the position of the target object Ob can be accurately detected (position detection step).

(Main effects of this form)
As described above, in the position detection device 10 of the present embodiment, the detection light source unit 12 emits the detection light L2 radially, and the intensity increases from one side to the other side in the emission angle range of the detection light L2. A light intensity distribution that varies (first light intensity distribution LID1 and second light intensity distribution LID2) is formed, and the light receiving unit 13 detects the light reflected by the target object Ob located in the detection target space 10R in which the light intensity distribution is formed. The light L2 is received. Here, since the intensity of the detection light L2 reflected by the target object Ob is proportional to the intensity at the position where the target object Ob is located in the light intensity distribution, the light reception intensity at the light receiving unit 13 is at the position of the target object Ob. Correspond. Therefore, the position detection unit 50 can detect the position of the target object Ob based on the received light intensity at the light receiving unit 13. According to this method, since the light intensity distribution of the detection light L2 emitted radially from the light source unit for detection 12 is used, the light intensity distribution can be formed over a wide space, and the detection target space 10R is wide.

  Further, the position detection unit 50 is configured so that the received light intensity at the light receiving unit 13 is equal during the first lighting operation (first period) and the second lighting operation (second period) in the detection light source unit 12. The angular position is detected based on a comparison result between the first drive current value supplied to the detection light source unit 12 during the first lighting operation and the second drive current value supplied to the detection light source unit 12 during the second lighting operation. Therefore, the influence of ambient light such as outside light can be absorbed.

  During the position detection, the light receiving unit 13 receives the detection light L2 reflected by the target object Ob, and also receives the detection light (stray light L5) reflected by the object Sb other than the target object. Here, since the intensity of the stray light L5 is proportional to the intensity of the detection light L2, when the first drive current value and the second drive current value are adjusted, the intensity of the stray light L5 also fluctuates. The compensation light source unit 14 emits the compensation light L4 incident on the light receiving unit 13 without passing through the detection target space 10R in which the one light intensity distribution LID1 and the second light intensity distribution LID2 are formed. In addition, when the light source driving unit 51 supplies a driving current to the first light source for detection 121 in the first period, the light source driving unit 51 also supplies a driving current to the light source for compensation 14 and supplies the second light source for detection 122 in the second period. When supplying the drive current, the drive current is also supplied to the compensation light source unit 14. The light source driving unit 51 includes a light source circuit 780. When the first driving current value and the second driving current value supplied to the first detection light source 121 and the second detection light source 122 are increased, compensation is performed. When the third drive current value supplied to the light source unit 14 is reduced and the first drive current value and the second drive current value are reduced, the third drive current value supplied to the compensation light source unit 14 is increased. Therefore, the intensity change of the received light intensity of the stray light L5 when the first drive current value and the second drive current value are adjusted can be corrected by the intensity change of the received light intensity of the compensation light L4. Therefore, it is possible to prevent occurrence of a detection error caused by the detection light L2 being reflected by the object Sb other than the target object and entering the light receiving unit 13.

  Further, the light source driving unit 51 includes a light source circuit 780, and the light source circuit 780 has a constant frequency during the first period when driving the first detection light source 121 and the second detection light source 122 by voltage amplitude modulation. A voltage corresponding to the difference between the voltage and the driving voltage supplied to the first detection light source 121 is applied to the compensation light source unit 14, and is supplied to the constant voltage and the second detection light source 122 in the second period. A voltage corresponding to the difference from the drive voltage is applied to the compensation light source unit 14. According to such a configuration, the third drive current value can be made inversely proportional to the increase or decrease of the first drive current value and the second drive current value with a relatively simple circuit configuration.

  Moreover, since the detection light L2 is infrared light, it is not visually recognized. Therefore, even when information is displayed on the viewing surface 41, there is an advantage that the detection light L2 does not hinder the viewing of information.

[Embodiment 2]
FIG. 10 is an explanatory diagram of the light source circuit 780 provided in the light source driving unit 51 of the position detection device 10 according to the second embodiment of the present invention, and FIGS. 10A and 10B are circuits of the light source circuit 780. FIG. 4 is an explanatory diagram showing the relationship between the anode voltage applied to the light source unit for detection 12 and the anode voltage applied to the light source unit for compensation 14. The basic configuration of the present embodiment is the same as that of the first embodiment, and therefore, common portions will be described with the same reference numerals.

  In the first embodiment, the voltage amplitude modulation method is used to control the drive current value for the detection light source unit 12. However, as in the present embodiment, the drive current value for the detection light source unit 12 is set by the pulse width modulation method. The present invention may be applied to control.

  In this case, the light source driving unit 51 shown in FIG. 5A includes the light source circuit 780 shown in FIG. 10A, and the light source circuit 780 is connected to the first light source 121 for detection in the first period. A drive pulse complementary to the supplied drive pulse is supplied to the compensation light source unit 14, and the drive pulse complementary to the drive pulse supplied to the second detection light source 122 is compensated in the second period. The light source unit 14 is supplied. More specifically, in the light source circuit 780, the terminals 701 and 702 for outputting the drive current in the control IC 70 are connected to the anode terminal of the first detection light source 121 and the anode terminal of the second detection light source 122, respectively. ing. The terminal 701 of the control IC 70 is electrically connected to the anode terminal of the compensation light source unit 14 via the inverter 786 and the switching circuit 782, and the terminal 702 of the control IC 70 is connected via the inverter 787 and the switching circuit 782. And electrically connected to the anode terminal of the compensation light source section 14. Based on the signal output from the terminal 703 of the control IC 70, the switching circuit 782 inverts the drive pulse supplied to the first detection light source 121 by the inverter 786 to the compensation light source unit 14 in the first period. In the second period, the drive pulse supplied to the second detection light source 122 is supplied to the compensation light source unit 14 via the inverter 787. A resistor 783 that adjusts the level of the third drive current value supplied to the compensation light source unit 14 is inserted between the cathode terminal of the compensation light source unit 14 and the ground potential.

  According to the light source circuit 780, as shown in FIG. 10B, when the light source driving unit 51 supplies a driving current to the first detection light source 121 in the first period, the driving light current is also supplied to the compensation light source unit 14. Supplied. Further, when the light source driving unit 51 increases the duty ratio of the driving pulse supplied to the first detection light source 121 to increase the first driving current value, the duty ratio of the driving pulse supplied to the compensation light source unit 14 To reduce the third drive current value. Further, when the duty ratio of the drive pulse supplied to the first detection light source 121 is reduced to reduce the first drive current value, the duty ratio of the drive pulse supplied to the compensation light source unit 14 is increased to increase the duty ratio. 3. Increase the drive current value. The same applies when the light source driving unit 51 drives the second light source 122 for detection. Here, the level of the third drive current value supplied to the compensation light source unit 14 is set by a resistor 783 inserted between the anode terminal of the compensation light source unit 14 and the constant potential line 781. Accordingly, the first drive current value and the third drive current value are in an inversely proportional or substantially inversely proportional relationship, and the second drive current value and the third drive current value are in an inversely proportional or approximately inversely proportional relationship.

Therefore, also in this embodiment, as in the first embodiment, in any period, the compensation light L4 in the light receiving unit 13 is expressed as follows: the light reception intensity of the following equation compensation light L4 + the light reception intensity of stray light L5 = constant or substantially constant. The sum of the received light intensity and the received light intensity of the stray light L5 is constant or substantially constant. Therefore, the intensity change of the received light intensity of the stray light L5 when the first drive current value and the second drive current value are adjusted can be corrected by the intensity change of the received light intensity of the compensation light L4. Therefore, it is possible to prevent the detection error caused by the detection light L2 being reflected by the object Sb other than the target object and being incident on the light receiving unit 13, and the like and substantially the same effect as the first embodiment can be obtained.

[Embodiment 3]
FIG. 11 is an explanatory diagram of a light emitting / receiving unit of the position detection apparatus 10 according to Embodiment 3 of the present invention. FIG. 12 is an explanatory diagram of the light source unit in the light emitting / receiving unit shown in FIG. 11, and FIGS. 12A and 12B show how the first detection light L2s is emitted during the first lighting operation in the first period. FIG. 6 is an explanatory diagram showing the state in which the second detection light L2t is emitted during the second lighting operation in the second period. FIG. 13 is an explanatory diagram illustrating an electrical configuration and the like of the position detection device 10 according to the third embodiment of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment and the like, the light guide LG is used as the detection light source unit 12, but in this embodiment, the XY coordinates of the target object Ob are detected based on the same principle as in the first embodiment without using the light guide. . More specifically, as shown in FIG. 11, each of the detection light source units 12 (the first detection light source unit 12 </ b> A and the second detection light source unit 12 </ b> B) of the position detection device 10 of this embodiment has a plurality of detections. Light source 120 (first detection light source 121 and second detection light source 122), a strip-shaped flexible substrate 180 on which a plurality of detection light sources 120 are mounted, and a shape curved in the length direction (circumferential direction). A light source support member 150 having a fan-shaped or semicircular shape having a convex curved surface 155 is provided. In this embodiment, the convex curved surface 155 has a shape curved in an arc shape in the length direction (circumferential direction).

  In this embodiment, as the flexible substrate 180, a strip-shaped first flexible substrate 181 (first light source module) and a strip-shaped second flexible substrate 182 that is parallel to the first flexible substrate 181 in the width direction (Z-axis direction). (Second light source module) is used. A plurality of first detection light sources 121 are mounted on the first flexible substrate 181 in the length direction as a plurality of detection light sources 120, and the second flexible substrate 182 is mounted in the length direction thereof. A plurality of second light sources for detection 122 are mounted as the plurality of light sources for detection 120. Each of the detection light sources 120 uses an LED.

  In both of the two detection light source units 12 (the first detection light source unit 12A and the second detection light source unit 12B), the light source support member 150 includes the first light source support member 151 and the second light source support member 152. And the first light source support member 151 and the second light source support member 152 are symmetrical with each other in the Z axis direction. The first light source support member 151 has an arcuate convex curved surface 155a constituting the lower half of the convex curved surface 155, and a convex curved surface at the end of the convex curved surface 155a opposite to the side where the second light source support member 152 is located. And a fan-shaped or semi-circular flange 156a projecting from 155a, and the first flexible substrate 181 is disposed on the convex curved surface 155a. The second light source support member 152 has an arcuate convex curved surface 155b constituting the upper half of the convex curved surface 155, and a convex curved surface at the end of the convex curved surface 155b opposite to the side where the first light source support member 151 is located. And a fan-shaped or semi-circular flange 156b protruding from 155b, and a second flexible substrate 182 is disposed on the convex curved surface 155b. Here, a portion sandwiched between the first flexible substrate 181 and the second flexible substrate 182 in the Z-axis direction is a light-transmitting light guide unit 128, and the light receiving unit 13 is located behind the light guide unit 128. A light receiving element 130 is arranged.

  In the position detection device 10 configured as described above, in order to detect the position of the target object Ob in the detection target space 10R, the plurality of first detection light sources 121 mounted on the first flexible substrate 181 and the second flexible light source 121 The plurality of second detection light sources 122 mounted on the substrate 182 are turned on in different periods. At that time, in the first lighting operation (first period) in which all of the plurality of first detection light sources 121 are turned on and all of the plurality of second detection light sources 122 are turned off, the level of emission intensity is shown in FIG. As indicated by the arrow Pa, the emission intensity of the first light source 121 for detection from the side where the one end 181f in the length direction of the first flexible substrate 181 is located toward the side where the other end 181e is located. Decrease. Therefore, in the first light intensity distribution LID1 of the detection light L2 emitted to the detection target space 10R, the light intensity is high in the angular direction in which the one end 181f in the length direction of the first flexible substrate 181 is located. Thus, the light intensity continuously decreases in the angular direction in which the other end 181e is located.

  On the other hand, in the second lighting operation (second period) in which all of the plurality of second detection light sources 122 are turned on and all of the plurality of first detection light sources 121 are turned off, the emission intensity is shown in FIG. As indicated by the arrow Pb, the height of the second flexible substrate 182 is changed from the side where the end 182f on one side is located toward the side where the other end 182e is located. Increase the emission intensity. Therefore, in the second light intensity distribution LID2 of the detection light L2 emitted to the detection target space 10R, the light intensity is high in the angular direction in which the other end 182e of the second flexible substrate 182 in the length direction is located. Accordingly, the light intensity continuously decreases in the angular direction in which the one end 182f is located.

  Therefore, if the first lighting operation and the second lighting operation are performed in each of the first detection light source unit 12A and the second detection light source unit 12B, the position of the target object Ob ( XY coordinates) can be detected. At that time, the sum of the drive currents supplied to the plurality of first detection light sources 121 (first drive current value) and the sum of the drive currents supplied to the plurality of second detection light sources 122 (second drive current values). Based on this, the angular position of the target object Ob may be detected.

  Further, when changing the emission intensity for each of the plurality of detection light sources 120, the drive current may be changed for each detection light source 120 using a resistance element or the like. More specifically, as illustrated in FIG. 13, the light source driving unit 51 includes a first drive current balance adjustment circuit 791 and a second drive current balance adjustment circuit 792, and the first drive current balance adjustment circuit 791. The second drive current balance adjustment circuit 792 includes, for example, a resistor circuit provided with a resistor corresponding to each of the plurality of detection light sources 120 on a one-to-one basis. The first drive current balance adjustment circuit 791 is a circuit for performing the first lighting operation described with reference to FIG. 12A in the first period, and the drive current for the detection light source 120 is supplied to one end. It decreases from the side of the part 181f toward the end part 181e on the other side. The second drive current balance adjustment circuit 792 is a circuit for performing the second lighting operation described with reference to FIG. 12B in the second period, and supplies the drive current to the detection light source 120 to the other end. It decreases from the side of the part 181e toward the end part 181f on one side.

  Also in the position detection device 10 having such a configuration, if the light source driving unit 51 is provided with the light source circuit 780 described with reference to FIG. 8 or FIG. 10, the detection light L2 is reflected by the object Sb other than the target object and the light receiving unit. The present embodiment has substantially the same effects as those of the first and second embodiments, such as preventing the occurrence of detection errors caused by being incident on the light.

[Forms of other embodiments]
In the first embodiment, the detection light source 120 is provided in each of the two ride guides LG. However, the detection light sources 120 are provided at both ends of the single ride guide LG, and the detection light sources 120 are alternately turned on. Light intensity distributions in opposite directions may be formed in the first period and the second period. In the third embodiment, two detection light sources 120 are provided. However, one detection light source 120 is provided and supplied to the plurality of detection light sources 120 in the first period and the second period. The magnitude relationship of the drive currents may be reversed to form light intensity distributions in opposite directions in the first period and the second period. Also in the position detection device 10 having such a configuration, when the compensation light source unit 14 that emits the compensation light L4 incident on the light receiving unit 13 without passing through the detection target space 10R is provided and the intensity of the detection light L2 is increased. When the intensity of the compensation light L4 is reduced and the intensity of the detection light L2 is reduced, if the intensity of the compensation light L4 is increased, the detection light L2 is reflected by the object Sb other than the target object and is reflected on the light receiving unit 13. Generation of detection errors due to incidence can be prevented.

  In the above embodiment, the two detection light source units 12 are used. However, the position of the target object Ob may be detected using one detection light source unit 12.

  In addition, the present invention is not limited to the position detection device of the system described in the above embodiment, but is described in JP-T-2003-534554, JP-A-2010-127671, JP-A-2009-295318, and the like. You may apply to the position detection apparatus which employ | adopted the system.

[Configuration example of position detection system]
(Specific example 1 of the position detection system 1)
FIG. 14 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 position detection device 10 are the same as the configurations described with reference to FIGS. A reference numeral is attached and the description is omitted.

  In the position detection system 1 according to the above embodiment, as shown in FIG. 14, the display device 110 is used as the viewing surface constituent member 40, and the position described with reference to FIGS. If the detection apparatus 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 display device 110 is a direct-view display device or a rear projection display device using the viewing surface constituent member 40 as a screen.

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

(Specific example 2 of the position detection system 1)
With reference to FIG. 15, 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. 15 is an explanatory diagram of a specific example 2 (a display system with an input function / a projection display system with an input function) of the position detection system 1 to which the present invention is applied. In addition, in the projection type display system with a position function of this embodiment, the configurations of the position detection system 1 and the 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 projection display system 200 with an input function shown in FIG. 15 (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 changed to 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 position detection device 10 is added to the image projection device 250 and configured integrally. For this reason, the position detection device 10 emits the detection light L2 along a 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 position detection device 10 and the screen 80 are integrated, a screen device with an input function can be configured.

(Other specific examples of the position detection system 1)
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.

1 ··· Position detection system, 10 ··· Position detection device, 10R ··· Detection target space, 12 ··· Light source for detection, 12A · · · First light source for detection, 12B ... 2nd light source for detection, 13... Light receiving unit, 13 A... First light receiving unit, 13 B... Second light receiving unit, 14... Compensation light source unit, 14 A... First compensation light source unit, 14 B. 40..Viewing surface component, 41..Viewing surface, 50..Position detection unit, 100..Display system with input function, 120..Light source for detection, 121..Light source for first detection, 122..No. 2 detection light source, 130... Light receiving element, 200... Projection type display system with input function, 250... Image projection device, Ob .. target object, Sb.

Claims (10)

A position detection device for optically detecting the position of a target object,
A light source unit for detection that emits a first detection light that forms a first light intensity distribution and a second detection light that forms a second light intensity distribution different from the first light intensity distribution;
A light receiving unit that receives reflected light of the first detection light and the second detection light reflected by the target object located in a space in which the first light intensity distribution and the second light intensity distribution are formed;
A compensation light source unit that emits compensation light incident on the light receiving unit without passing through the space in which the first light intensity distribution and the second light intensity distribution are formed;
The first drive current value supplied to the detection light source unit in the first period for emitting the first detection light and the compensation light, and the detection light source in the second period for emitting the second detection light and the compensation light. A light source driving unit that increases or decreases a second driving current value supplied to the compensation unit and a third driving current value supplied to the compensation light source unit;
The target object based on the first driving current value and the second driving current value when the light receiving intensity of the light receiving unit in the first period is equal to the light receiving intensity of the light receiving unit in the second period A position detector for detecting the position of
Have
The light source driving unit decreases the third driving current value when increasing the first driving current value, increases the third driving current value when decreasing the first driving current value, and performs the second driving. The position detecting device, wherein when the current value is increased, the third drive current value is decreased, and when the second drive current value is decreased, the third drive current value is increased. The light source driving unit sets the first driving current value and the second driving current value as initial current values and emits the first detection light and the second detection light, and Increase or decrease the first drive current value and the second drive current value based on the light reception result,
The position detection unit is configured to obtain a first drive current value and an initial current value when a light reception intensity of the light receiving unit in the first period is equal to a light reception intensity of the light receiving unit in the second period. The position detection device according to claim 1, wherein the position of the target object is detected based on a difference and a difference between the second drive current value and the initial current value.   2. The detection light source unit includes a first detection light source that emits the first detection light and a second detection light source that emits the second detection light. 2. The position detection device according to 2.   The light source driving unit drives the first detection light source and the second detection light source by voltage amplitude modulation, and in the first period, a constant voltage and a drive voltage supplied to the first detection light source A voltage corresponding to the difference is applied to the compensation light source unit, and a voltage corresponding to the difference between the constant voltage and the drive voltage supplied to the second detection light source is applied to the compensation light source unit in the second period. The position detection device according to claim 3, wherein the position detection device is applied.   The light source driving unit drives the first detection light source and the second detection light source by pulse width modulation, and is complementary to a drive pulse supplied to the first detection light source in the first period. A driving pulse is supplied to the compensation light source unit, and a driving pulse complementary to the driving pulse supplied to the second detection light source is supplied to the compensation light source unit in the second period. The position detection device according to claim 3, wherein In a state where the target object does not exist in the space where the first light intensity distribution and the second light intensity distribution are formed,
When the detection light source unit is driven with the first drive current value set to an initial current value, the detection intensity is increased and the first drive current value is increased or decreased from the initial current value. The light receiving intensity at the light receiving unit when the light source unit for driving is equal,
When the detection light source unit is driven with the second drive current value set to an initial current value, the detection intensity is increased and the second drive current value is increased or decreased from the initial current value. 6. The position detection device according to claim 1, wherein the received light intensity at the light receiving unit when the light source unit is driven is equal. In a state where the target object does not exist in the space where the first light intensity distribution and the second light intensity distribution are formed,
The sum of the received light intensity of the first detection light at the light receiving unit and the received light intensity of the compensation light at the light receiving unit is equal to the received light intensity of the second detection light at the light receiving unit and the received light intensity at the light receiving unit. The position detection device according to claim 6, wherein the position detection device is equal to a sum of the received light intensity of the compensation light. A display system with an input function comprising the position detection device defined in any one of claims 1 to 7,
A display device having a display surface on which an image is displayed;
A display system with an input function, wherein an image displayed on the display surface in the display device is switched based on a position detection result of the target object in the position detection device. A display system with an input function comprising the position detection device defined in any one of claims 1 to 7,
An image projection device for projecting an image;
A display system with an input function, wherein an image projected from the image projection device is switched based on a position detection result of the target object in the position detection device. A position detection method for optically detecting the position of a target object,
First detection light is emitted from the light source unit for detection in the first period to form a first light intensity distribution, and is incident on the light receiving unit without passing through the space in which the first light intensity distribution is formed from the compensation light source unit. A first light emitting step of emitting compensation light to be
A second light emitting step of emitting a second detection light from the detection light source unit in a second period to form a second light intensity distribution and emitting the compensation light from the compensation light source unit;
A first drive current value supplied to the detection light source unit in the first period, a second drive current value supplied to the detection light source unit in the second period, and a third drive supplied to the compensation light source unit A current increase / decrease process for increasing / decreasing the current value;
The first driving current value and the second driving current value when the light receiving intensity of the light receiving unit in the first period and the light receiving intensity of the light receiving unit in the second period are equal to each other. A position detecting step of detecting a position of the target object located in a space in which a light intensity distribution and the second light intensity distribution are formed;
Have
In the current increasing / decreasing step, when the first drive current value is increased, the third drive current value is decreased, and when the first drive current value is decreased, the third drive current value is increased, and the second drive current value is increased. A position detection method comprising: decreasing the third drive current value when increasing a current value; and increasing the third drive current value when decreasing the second drive current value.

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