JP2015034826A - Optical position detection device and equipment with position detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical position detection device that can detect the position of a target object without being affected by detection light reflected by an object other than the target object, and equipment with a position detection function.SOLUTION: When a plurality of light sources 12 for detection are successively turned on in an optical position detection device 10, a first light-receiving part 31 receives detection light L3 reflected by a target object Ob. At the time, it is probable that there is a case where detection light L4 reflected by an object Sb other than the target object Ob is made incident to the first light-receiving part 31, however A position detection part 50 detects the position of the target object Ob based on a difference between light-receiving intensity in the first light-receiving part 31 and light-receiving intensity in the second light-receiving part 32 because the optical position detection device 10 includes: a light source part 81 for compensation that emits compensation light L5 which is not made incident to a detection target space 10R; and a second light-receiving part 32 that receives the compensation light L5 without receiving the detection light L2, L3 and L4.

Description

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

  As an optical position detection device that optically detects a target object, for example, detection light that is emitted from each of a plurality of light sources for detection toward the target object via a transparent member and reflected by the target object Has been proposed in which light is transmitted through a translucent member and detected by a light receiving unit. In the optical position detection device having such a configuration, the position of the target object is detected based on the detection result of the detection light in the light receiving unit (see Patent Document 1).

  In addition, a light guide plate is provided in the optical position detection device, the detection light emitted from each of the plurality of light sources for detection is emitted toward the target object through the light guide plate, and the detection light reflected by the target object is received by the light receiving unit. The method of detecting by this is also proposed (see Patent Documents 2 and 3).

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

  When the optical position detection device described in Patent Documents 1 to 3 is actually used, detection light reflected by an object other than the target object enters the light receiving unit in addition to detection light reflected by the target object. There is a problem that the position detection accuracy of the target object is low. For example, in the optical position detection device described in Patent Document 1, detection light reflected on the back surface side of the translucent member enters the light receiving unit. In addition, in the optical position detection devices described in Patent Documents 2 and 3, when there is an object other than the target object such as fixtures in the detection light emission space, the detection light reflected by the object enters the light receiving unit. End up.

  In addition to the detection light reflected by the target object and the detection light reflected by an object other than the target object, ambient light such as external light may enter the light receiving unit. Unlike the influence of detection light reflected by an object other than the target object, it can be removed relatively easily. For example, if pulse-modulated light is used as the detection light, the light reception signal of the detection light reflected from the target object is a high-frequency signal, whereas the light reception signal of the ambient light is a low-frequency signal. If used, the received light signal corresponding to the ambient light can be excluded relatively easily. Further, if the position of the target object is detected using the driving conditions for the detection light source when the detection light sources are differentiated so that the detection intensities at the light receiving parts are equal, the influence of the ambient light is excluded. be able to. However, in these methods, it is impossible to exclude the influence of detection light reflected by an object other than the target object.

  In view of the above problems, an object of the present invention is to provide an optical position detection device capable of detecting the position of a target object without being affected by detection light reflected by an object other than the target object, and the optical type. An object of the present invention is to provide a device with a position detection function provided with a position detection device.

  In order to solve the above problems, the present invention is an optical position detection device that optically detects the position of a target object, and includes a plurality of detection light sources that emit detection light, and the plurality of detection light sources. A light source driving unit for driving, a first light receiving unit for receiving the detection light reflected by the target object located in an emission space of the detection light, and a compensation light source unit for emitting compensation light not incident on the emission space The second light receiving unit that receives the compensation light without receiving the detection light, and the difference between the light reception intensity at the first light reception unit and the light reception intensity at the second light reception unit. And a position detection unit for detecting the position.

  In the present invention, a configuration is adopted in which the light receiving intensity of the compensation light at the second light receiving unit is set to the light receiving intensity at the first light receiving unit of the detection light reflected by an object other than the target object. be able to.

  In the present invention, a plurality of detection light sources that emit detection light are used, and when the plurality of detection light sources are sequentially turned on, the first light receiving unit receives the detection light reflected by the target object. Therefore, if the detection result in the first light receiving unit is directly used, or if the driving condition such as the driving current value when the light sources for detection are differentiated based on the received light intensity in the first light receiving unit is used, the target The position of the object can be detected. Here, in addition to the detection light reflected by the target object, detection light reflected by an object other than the target object may be incident on the first light receiving unit. A compensation light source unit that emits light and a second light receiving unit that receives the compensation light without receiving the detection light are provided. Therefore, if the light receiving intensity of the compensation light at the second light receiving unit is set to the light receiving intensity at the first light receiving unit of the detection light reflected by an object other than the target object, the first light receiving unit at the position detecting unit. When the position of the target object is detected based on the difference between the received light intensity at the light receiving unit and the received light intensity at the second light receiving unit, the detection result is automatically influenced by the detection light reflected by the object other than the target object. It will be removed. Therefore, the position of the target object can be detected without being affected by the detection light reflected by the object other than the target object.

  In the present invention, the light source drive unit emits the detection light from a part of the plurality of detection light sources and outputs the detection light from the other part of the detection light sources. A second operation for emitting light, and the position detection unit is configured to detect a difference between a light reception intensity at the first light receiving unit and a light reception intensity at the second light receiving unit during the first operation, and the second operation. A configuration in which the position of the target object is detected based on the difference between the received light intensity at the first light receiving unit and the received light intensity at the second light receiving unit during operation can be employed. A detection principle is employed in which a first operation for emitting detection light from some of the detection light sources and a second operation for emitting detection light from other detection light sources are employed. Even in this case, in the present invention, since the difference between the received light intensity at the first light receiving unit and the received light intensity at the second light receiving unit is used, the detection light reflected by the object other than the target object is not affected. The position of the target object can be detected.

  In the present invention, the position detection unit includes a difference between a light reception intensity at the first light receiving unit during the first operation and a light reception intensity at the second light reception unit, and the first light reception during the second operation. The light source driving unit is controlled so that the difference between the received light intensity at the light receiving portion and the received light intensity at the second light receiving portion becomes equal, and the driving condition for the detection light source during the first operation and the second operation The position of the target object is detected based on the driving condition for the detection light source at the time, and the emission intensity of the compensation light emitted from the compensation light source unit is the same as that during the first operation during the first operation. It changes in conjunction with the emission intensity of the detection light emitted from the detection light source, and changes in conjunction with the emission intensity of the detection light emitted from the detection light source in the second operation during the second operation. It is preferable to do. According to such a configuration, when the detection light sources are differentiated from each other, even when the driving conditions such as the driving current supplied to the detection light sources change, the emission intensity of the compensation light emitted from the compensation light source unit also changes. Therefore, the position of the target object can be detected without being affected by the detection light reflected by the object other than the target object.

  In the present embodiment, the light source drive unit supplies power to the detection light source and the compensation light source unit that emits the detection light during the first operation, and the second light source during the second operation. It is preferable that power is supplied to the detection light source and the compensation light source unit that emit the detection light during operation. According to this configuration, the detection light source and the compensation light source unit can be driven by the common light source driving unit, so that the circuit configuration can be simplified. In addition, the drive conditions such as the drive current supplied to the detection light source change when the detection light sources are differentiated. In response to the change, the emission intensity of the compensation light emitted from the compensation light source unit It is easy to change.

  In the present invention, the ratio of the drive current supplied to the light source for detection that emits the detection light during the first operation and the drive current supplied to the light source for compensation, and the detection light during the second operation It is preferable that a compensation drive current setting unit is provided that defines a ratio between a drive current supplied to the detection light source that emits light and a drive current supplied to the compensation light source unit. According to this configuration, the detection light emitted from the detection light source during the first operation is reflected by an object other than the target object and incident on the first light receiving unit, and the detection light emitted from the detection light source during the second operation. Even when the amount of light reflected by an object other than the target object and incident on the first light receiving unit is different, the influence of the detection light reflected by the object other than the target object and incident on the first light receiving unit is affected. It can be properly excluded.

  In the present invention, the compensation light source unit emits first compensation light as the compensation light during the first operation, and emits second compensation light as the compensation light during the second operation. And a second light source for compensation. According to such a configuration, it is easy to emit compensation light having an appropriate intensity during the first operation and the second operation.

  In the present invention, the first light receiving unit is a first photoelectric conversion element, and the second light receiving unit is a second photoelectric conversion electrically connected in parallel with a reverse polarity to the first photoelectric conversion element. An element is preferred. According to such a configuration, the difference between the light receiving intensity at the first light receiving part and the light receiving intensity at the second light receiving part is output from the connection point between the first light receiving part and the second light receiving part. The difference between the received light intensity at and the received light intensity at the second light receiving section can be easily output.

  The optical position detection device to which the present invention is applied is used in various devices with position detection functions together with a viewing surface constituent member having a viewing surface, for example. As the viewing surface constituent member, a direct-view image generating device that displays an image can be used. In this case, the viewing surface is an image display surface on which the image is displayed in the direct-view image generating device. According to this configuration, the device with a position detection function can be configured as a direct view display device with a position detection function. In addition, as the viewing surface constituent member, a screen on which information is visually recognized can be used. In this case, the viewing surface is a screen surface on which the information is visually recognized on the screen. According to such a configuration, the device with a position detection function can be configured as a screen device with a position detection function. Furthermore, as the viewing surface constituent member, a translucent member that covers an exhibit can be used. In this case, the viewing surface is on the opposite side of the viewing surface constituent member from the side on which the exhibit is disposed. This is the surface on which the exhibit is viewed. According to this configuration, the device with a position detection function can be configured as a show window with a position detection function. Furthermore, as the viewing surface constituent member, it is possible to adopt a configuration including a base that supports a moving game medium. In this case, the viewing surface is a side of the base on which the game medium is viewed. Surface. According to such a configuration, the device with a position detection function can be configured as an amusement device such as a pachinko machine or a coin game.

It is explanatory drawing which shows typically the whole structure of the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows layouts, such as a light source for a detection, in the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing when the light source for detection in the optical position detection apparatus which concerns on Embodiment 1 of this invention is seen from the side. It is a timing chart which shows operation | movement in the optical position detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows typically the whole structure of the optical position detection apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing which shows the structural example at the time of using the reference light source in the optical position detection apparatus which concerns on Embodiment 1, 2 of this invention. It is explanatory drawing which shows the principal part of the optical position detection apparatus which concerns on the other structural example 1 of this invention. It is explanatory drawing of the detection light used with the optical position detection apparatus which concerns on the other structural example 1 of this invention. It is explanatory drawing which shows a mode that the light source for a detection is lighted sequentially by a predetermined pattern in the optical position detection apparatus concerning the other structural example 1 of this invention, and light intensity distribution is formed. It is explanatory drawing which shows a mode that the light intensity distribution for coordinate detection is formed with the detection light radiate | emitted from the light source for a detection in the optical position detection apparatus which concerns on the other structural example 1 of this invention. It is explanatory drawing which shows typically the position detection principle in the optical position detection apparatus which concerns on the other structural example 1 of this invention. It is explanatory drawing which shows typically the principal part of the optical position detection apparatus which concerns on the other structural example 2 of this invention. It is explanatory drawing of two light source units which comprise a light source part in the optical position detection apparatus which concerns on the other structural example 2 of this invention. It is explanatory drawing which shows the position detection principle in the optical position detection apparatus which concerns on the other structural example 2 of this invention. It is explanatory drawing which shows the method of pinpointing the position of a target object in the optical position detection apparatus which concerns on the other structural example 2 of this invention. It is explanatory drawing of the screen apparatus with a position detection function (apparatus with a position detection function) to which this invention is applied. It is explanatory drawing of another screen apparatus with a position detection function (apparatus with a position detection function) to which this invention is applied. It is explanatory drawing of the projection type display apparatus (apparatus with a position detection function) with a position detection function to which this invention is applied.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, an axis that intersects with each other will be referred to as an X axis and a Y axis, an axis that intersects with the X axis and the Y axis will be referred to as a Z axis, and an emission direction of detection light will be described 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 shown as the Z1 side, and the other side is shown as the Z2 side.

[Embodiment 1]
(overall structure)
FIG. 1 is an explanatory diagram schematically showing the overall configuration of the optical position detection apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, an optical position detection device 10 of this embodiment is a device that optically detects the position of a target object Ob, and includes a plurality of detection light sources 12 that emit detection light L2, and a plurality of detection light sources. The first light receiving unit 51 that receives the detection light L3 reflected by the target object positioned in the emission space (detection target space 10R) of the detection light L2, and the first light receiving unit 31. And a position detection unit 50 that detects the position of the target object Ob based on the detection result. Three or more light sources are used as the plurality of light sources 12 for detection, and the number of light sources 12 for detection is four in this embodiment. More specifically, the optical position detection device 10 includes detection light sources 12A, 12B, 12C, and 12D as the four detection light sources 12, and emits the detection light L2 from these detection light sources 12. The space constitutes a detection target space 10R in which the position of the target object Ob is detected.

  Each of the detection light sources 12 (detection light sources 12A, 12B, 12C, 12D) is composed of a light emitting element such as an LED (light emitting diode), and the detection light sources 12 all have a peak wavelength of 840 to 1000 nm. Detection light L2 made of infrared light is emitted as diverging light. In this embodiment, since the target object Ob is often a fingertip or the like, as the detection light L2, infrared light in a wavelength region with a high reflectance at the target object Ob (human body) (near infrared of about 840 to 920 nm). Light) is used.

  The first light receiving unit 31 includes a photoelectric conversion element such as a photodiode or a phototransistor having a light receiving surface directed toward the detection target space 10R. In this embodiment, the first light receiving unit 31 has a sensitivity peak in the infrared region. It is a photodiode.

  Further, in this embodiment, as will be described in detail later, when an object Sb other than the target object Ob exists in the detection target space 10R, the detection light L4 reflected by the object Sb enters the first light receiving unit 31 as extra light, The position detection accuracy of the target object Ob is lowered. Therefore, the optical position detection device 10 is provided with a compensation light source unit 81 that emits the compensation light L5 that is not incident on the detection target space 10R. In this embodiment, the compensation light source unit 81 is used for the first compensation. It comprises a light source 12S and a second compensation light source 12T. The first compensation light source 12 </ b> S and the second compensation light source 12 </ b> T are LEDs that emit infrared light in the same wavelength region as the detection light source 12. In this embodiment, the optical position detection apparatus 10 does not receive the detection light L3 reflected by the target object Ob, the detection light L4 reflected by the object Sb other than the target object Ob, and ambient light such as external light. In addition, a second light receiving unit 32 that receives the compensation light L5 emitted from the compensation light source unit 81 (the first compensation light source 12S and the second compensation light source 12T) is provided. In the present embodiment, the second light receiving unit 32 is formed of a photodiode having a sensitivity peak in the infrared region, like the first light receiving unit 31.

  In the optical position detection device 10 having such a configuration, in this embodiment, the light source driving unit 51 and a part responsible for a part of the position detection unit 50 are configured in the control IC 70. The control IC 70 includes a reference clock generator 71s that generates a reference clock, an A-phase reference pulse generator 71a that generates an A-phase reference pulse based on the reference clock, and a B that generates a B-phase reference pulse based on the reference clock. A phase reference pulse generating unit 71b, a timing control pulse generating unit 71t that generates a timing control pulse, and a synchronous clock generating unit 71u that generates a synchronous clock are provided.

  The control IC 70 also includes a pulse generator 75a that generates a predetermined drive pulse based on the A-phase reference pulse, a pulse generator 75b that generates a predetermined drive pulse based on the B-phase reference pulse, and a pulse generator And a switch unit 76 that controls which of the four detection light sources 12 is applied with the drive pulses generated by 75a and 75b. The light source drive unit 51 includes the pulse generators 75a and 75b and the switch unit 76. Is configured.

  The control IC 70 amplifies the detection results of the first light receiving unit 31 and the second light receiving unit 32, and the received light amount for measuring the received light amount based on the signal output from the differential amplifier 72. A measurement unit 73; and an adjustment amount calculation unit 74 that controls the pulse generators 75a and 75b based on the measurement result of the received light amount measurement unit 73 to adjust the current level of the drive pulse supplied to the detection light source 12. The differential amplifier 72, the received light amount measuring unit 73, and the adjustment amount calculating unit 74 have a part of the function of the position detecting unit 50. More specifically, the control IC 70 is controlled by an upper control unit 60 such as a personal computer, and the control unit 60 detects the position together with the differential amplifier 72, the received light amount measurement unit 73, and the adjustment amount calculation unit 74. A coordinate acquisition unit 55 constituting the unit 50 is included. Therefore, in this embodiment, the position detection unit 50 includes the differential amplifier 72, the received light amount measurement unit 73 and the adjustment amount calculation unit 74 of the control IC 70, and the coordinate acquisition unit 55 of the host control unit 60 (personal computer). It is configured.

  The control IC 70 includes a terminal 781 that receives a command from the host controller 60 and an external IO 77, and also includes a plurality of terminals 782 to 784, 787, and 788. Therefore, the control IC 70 can drive the detection light source 12 via the terminal 788, and the control IC 70 receives the detection results from the first light receiving unit 31 and the second light receiving unit 32 via the terminal 787. Entered. In addition, a drive potential and a ground potential are input to the control IC 70 via terminals 782 and 784. Further, the control IC 70 can output the adjustment result in the adjustment amount calculation unit 74 to the upper control unit 60 via the terminal 783.

(Layout of light source for detection, etc.)
FIG. 2 is an explanatory diagram showing a layout of the detection light source 12 and the like in the optical position detection device 10 according to Embodiment 1 of the present invention. FIGS. 2 (a) and 2 (b) are diagrams of the detection light source and the like. It is explanatory drawing which shows a three-dimensional layout, and explanatory drawing which shows planar layouts, such as a light source for a detection. FIG. 3 is an explanatory diagram when the light source for detection and the like in the optical position detection device according to the first embodiment of the present invention is viewed from the side.

  As shown in FIG. 2 and FIG. 3, the optical position detection device 10 of the present embodiment includes position detection of a display device with a position detection device, which will be described later, together with a translucent viewing surface constituent member 40 provided with a viewing surface 41. It is used to configure the functional device 1. In the device 1 with the position detection function, the entire space on the viewing surface 41 side (the other side Z2 in the Z-axis direction) with respect to the viewing surface constituent member 40 is the detection target space 10R of the optical position detection device 10.

  The viewing surface constituting member 40 is made of a sheet-like or plate-like light-transmitting member in which the detection light source 12 and the first light receiving portion 31 are arranged on one side Z1 in the Z-axis direction. In addition, each of the light sources for detection 12 has the light emitting portion directed toward the viewing surface constituting member 40, and the first light receiving portion 31 faces the light receiving surface toward the viewing surface constituting member 40. For this reason, the detection light source 12 (detection light sources 12A, 12B, 12C, 12D) is detected light L2 (detection) from the back surface 42 side opposite to the viewing surface 41 side in the viewing surface constituent member 40 to the viewing surface 41 side. Light L2a, L2b, L2c, L2d), and the first light receiving unit 31 detects the detection light L3 that is reflected by the target object Ob and transmitted to the back surface 42 side of the viewing surface constituent member 40. Note that the viewing surface constituent member 40 may be omitted depending on the type of the device 1 with a position detection function.

  In this embodiment, when viewed from the detection target space 10R (Z-axis direction), the detection light source 12A and the detection light source 12B are displaced in the X-axis direction and are substantially in the same position in the Y-axis direction. The detection light source 12C and the detection light source 12D are displaced in the X-axis direction and are substantially at the same position in the Y-axis direction. The detection light source 12A and the detection light source 12D are displaced in the Y-axis direction and are substantially in the same position in the X-axis direction. The light source for detection 12B and the light source for detection 12C are shifted in the Y-axis direction and are substantially in the same position in the X-axis direction.

(Basic principle of coordinate detection)
FIG. 4 is a timing chart showing the operation in the optical position detection apparatus 10 according to the first embodiment of the present invention. 1 to 4, the basic principle of detecting the position of the target object Ob located in the detection target space 10R in the optical position detection device 10 of the present embodiment will be described, and then the compensation light source unit 81 and the second An operation of compensating using the light receiving unit 32 will be described.

  First, in the optical position detection device 10 according to the present embodiment, the position detection unit 50 detects the difference between the detection light source 12 and the target object Ob between one of the two detection light sources 12 and the target object Ob. A ratio between the distance and the distance between the other detection light source 12 and the target object Ob is obtained, and the target object Ob is determined based on a contour line set with reference to the two detection light sources 12 corresponding to the ratio. The position of is detected.

  More specifically, as illustrated in FIG. 4A, the light source driving unit 51 performs only the detection light source 12A among the four detection light sources 12 as the first operation in the first coordinate information detection period tx. In the second operation, a B-phase drive pulse opposite to the A-phase is intermittently supplied only to the detection light source 12B. Therefore, in the first coordinate information detection period tx, the first light source 12A is turned on and the detection light L2a is emitted to the detection target space 10R, and the detection light source 12C is turned on and the detection light L2c is The second operation emitted to the detection target space 10R is executed alternately. As a result, as shown in FIG. 4C, the received light intensity at the first light receiving unit 31 is such that the detection light L2a emitted from the detection light source 12A in the first operation is reflected by the target object Ob and the first light reception. The detection intensity corresponding to the amount of light incident on the unit 31 and the detection intensity corresponding to the amount of light incident on the first light receiving unit 31 when the detection light L2c emitted from the detection light source 12C in the second operation is reflected by the target object Ob. And alternately change. Here, the light reception intensity at the first light receiving unit 31 during the first operation is a value corresponding to the positional relationship between the light source for detection 12A and the target object Ob, and at the first light receiving unit 31 during the second operation. The received light intensity is a value corresponding to the positional relationship between the detection light source 12C and the target object Ob.

  In this embodiment, the adjustment amount calculation unit 74 of the position detection unit 50 receives the received light intensity of the first light receiving unit 31 during the first operation and the second operation obtained through the differential amplifier 72 and the received light amount measurement unit 73. The drive current (control amount) for the detection light source 12A and the drive current (control amount) for the detection light source 12C are adjusted so that the received light intensity of the first light receiving unit 31 at the time becomes equal. For example, at the start of detection, the light source drive unit 51 supplies a drive current equal to the detection light source 12A and the detection light source 12C, and the received light intensity of the first light receiving unit 31 during the first operation and the second operation at that time. When the received light intensity of the first light receiving unit 31 at the time is different, the received light intensity of the first light receiving unit 31 during the first operation is equal to the received light intensity of the first light receiving unit 31 during the second operation. In addition, the drive currents for the detection light sources 12A and 12C are adjusted. In this differential, the ratio of the drive current and the adjustment amount of the drive current after adjusting the drive currents for the detection light sources 12A and 12C correspond to the position of the target object Ob with respect to the detection light sources 12A and 12C. Value. Therefore, the coordinate acquisition unit 55 of the position detection unit 50 can set a contour line based on the detection light sources 12A and 12C in the XY plane, and the target object Ob is positioned on the contour line.

  In this embodiment, in the second coordinate information detection period ty shown in FIG. 4B, the light source driving unit 51 performs the first operation among the four detection light sources 12 in substantially the same manner as the first coordinate information detection period tx. A phase A driving pulse is intermittently supplied only to the detection light source 12B, and as a second operation, a phase B driving pulse opposite to the A phase is intermittently supplied only to the detection light source 12D. . Therefore, in the second coordinate information detection period ty, the first light source 12B is turned on and the detection light L2b is emitted to the detection target space 10R, and the detection light source 12D is turned on and the detection light L2d is The second operation emitted to the detection target space 10R is executed alternately. As a result, as shown in FIG. 4C, the received light intensity at the first light receiving unit 31 is such that the detection light L2b emitted from the detection light source 12B in the first operation is reflected by the target object Ob and the first light reception. The detection intensity corresponding to the amount of light incident on the unit 31 and the detection intensity corresponding to the amount of light incident on the first light receiving unit 31 when the detection light L2d emitted from the detection light source 12D in the second operation is reflected by the target object Ob. And alternately change. Here, the intensity of light received by the first light receiving unit 31 during the first operation is a value corresponding to the positional relationship between the light source for detection 12B and the target object Ob, and is the value obtained by the first light receiving unit 31 during the second operation. The received light intensity is a value corresponding to the positional relationship between the light source for detection 12D and the target object Ob.

  Further, in the present embodiment, the adjustment amount calculation unit 74 of the position detection unit 50 also includes the differential amplifier 72 and the received light amount measurement unit 73 in the second coordinate information detection period ty, as in the first coordinate information detection period tx. The drive current (control amount) for the detection light source 12B so that the received light intensity of the first light receiving unit 31 during the first operation and the received light intensity of the first light receiving unit 31 during the second operation are equal. The drive current (control amount) for the detection light source 12D is adjusted. For example, at the start of detection, the light source driving unit 51 supplies a driving current equal to the detection light source 12B and the detection light source 12D, and the received light intensity of the first light receiving unit 31 during the first operation and the second operation at that time. When the received light intensity of the first light receiving unit 31 at the time is different, the received light intensity of the first light receiving unit 31 during the first operation is equal to the received light intensity of the first light receiving unit 31 during the second operation. In addition, the drive currents for the detection light sources 12B and 12D are adjusted. In such a differential, the ratio of the drive current after adjusting the drive current for each of the detection light sources 12B and 12D, the ratio of the adjustment amount of the drive current, and the like correspond to the position of the target object Ob with respect to the detection light sources 12B and 12D. Value. Therefore, the coordinate acquisition unit 55 of the position detection unit 50 can set a contour line based on the detection light sources 12B and 12D in the XY plane, and the target object Ob is positioned on the contour line.

  Therefore, the position detection unit 50 is configured such that the contour line obtained by the differential between the detection light source 12A and the detection light source 12C in the first coordinate information detection period tx, and the detection light source 12B in the second coordinate information detection period ty. The position (XY coordinate) of the target object Ob can be obtained from the position corresponding to the intersection with the contour line obtained by differential with the detection light source 12D.

The isoline can be obtained as follows by focusing on the distance function that the detection light L2 emitted from the detection light source 12 is reflected by the target object Ob and reaches the first light receiving unit 31. First, the detection light L2a emitted each parameter from the reflectance A _t = detection light sources 12A below T = target object Ob by the target object Ob
A distance function that reflects and reaches the first light receiving unit 31 A = detection light source 12A in a state where the target object Ob exists in the detection target space 10R
Detected intensity C _t of the first light receiving unit 31 when is illuminated C _t = the detection light L2c emitted from the detection light source 12C is the target object Ob
Distance function that reflects and reaches the first light receiving unit 31 C = Detection light source 12C in a state where the target object Ob exists in the detection target space 10R
The detected intensity of the first light receiving unit 31 when is turned on. The light emission intensity of the detection light source 12A and the detection light source 12C is represented by the product of the drive current and the light emission coefficient. In the following description, the light emission coefficient is 1. In the above differential, the drive current for the detection light source 12A when the received light intensity at the first light receiving unit 31 becomes equal is I _A, and the drive current for the detection light source 12C is I _C.

When the above-described differential is performed in a state where the target object Ob exists in the detection target space 10R,
A = T × A _t × I _A + Ambient Light ・ ・ Formula (1)
C = T × C _t × I _C + Ambient Light ・ ・ Formula (2)
The relationship is obtained.

Here, since the detection intensity of the first light receiving unit 31 at the time of differential is equal, from the formulas (1) and (2), the following formula T × A _t × I _A + ambient light = T × C _t × I _C + ambient light _{T × A t × I A =} T × C t × I C ·· formula (3)
Is guided.

Further, the ratio P _AC between the distance functions A _t and C _t is expressed by the following equation: P _AC = A _t / C _t ··· (4)
From the formulas (3) and (4), the distance function ratio P _AC is P _AC = I _C / I _A.
It is expressed as In this equation (5), there is no term of ambient light. In addition, regardless of the location of the target object Ob, if the reflectance is constant, the reflectance term of the target object Ob does not exist. Therefore, the ambient light and the reflectance of the target object Ob do not affect the ratio P _AC between the distance functions A _t and C _t . In addition, about said mathematical model, you may correct | amend in order to cancel the influence etc. of the detection light L2 which entered without reflecting with the target object Ob.

Here, the detection light source 12 is a point light source, and the light intensity at a certain point is inversely proportional to the square of the distance from the light source. Therefore, the ratio of the separation distance P1 from the detection light source 12A through the target object Ob to the first light receiving unit 31 and the separation distance P2 from the detection light source 12C through the target object Ob to the first light receiving unit 31 is as follows: Formula P _AC = (P1) ² : (P2) ²
Is required. Therefore, an isoline corresponding to the ratio P1: P2 can be set on the basis of the detection light source 12A and the detection light source 12C in the XY plane, and the target object Ob is positioned on the isoline.

  Similarly, if the detection light source 12B and the detection light source 12D are differentiated to obtain the ratio of the distance between the detection light source 12B and the target object Ob and the distance between the detection light source 12D and the target object Ob, XY An isoline can be set on the basis of the detection light source 12B and the detection light source 12D in the plane, and the target object Ob is positioned on the isoline.

  Therefore, the position detection unit 50 has a ratio line obtained by differential between the detection light source 12A and the detection light source 12C and a ratio line obtained by differential between the detection light source 12B and the detection light source 12D. If the intersection is obtained, the position (XY coordinate) of the target object Ob can be obtained. According to such a configuration, since the differential between the detection light sources 12 is used, the influence of ambient light or the like can be automatically corrected.

(Configuration of compensation light source unit 81 and the like)
In the optical position detection device 10 of the present embodiment, as shown in FIGS. 1 and 2, if an object Sb other than the target object Ob exists in the detection target space 10R, the detection light L4 reflected by the object Sb is used as extra light. The light enters the first light receiving unit 31. Therefore, as shown in FIG. 4C, in the first coordinate information detection period tx, the light reception intensity at the first light receiving unit 31 includes the light reception intensity P3 of the detection light L3 reflected by the target object Ob and the object Sb. And the light reception intensity P4 (gray area) of the detection light L4 reflected by. Similarly, in the second coordinate information detection period ty, the received light intensity at the first light receiving unit 31 includes the received light intensity of the detection light L3 reflected by the target object Ob and the received light of the detection light L4 reflected by the object Sb. Intensity (gray area) is included.

  Therefore, as shown in FIG. 1, the optical position detection device 10 of the present embodiment includes a compensation light source unit 81 (first compensation light source 12S and second compensation light source 81) that emits compensation light L5 that does not enter the detection target space 10R. Light source 12T) and a second light receiving unit 32 that receives the compensation light L5 without receiving the detection light L3 reflected by the target object and the detection light L4 reflected by the object Sb other than the target object Ob. . Such a configuration includes, for example, a configuration in which the compensation light source unit 81 (the first compensation light source 12S and the second compensation light source 12T) and the second light receiving unit 32 are provided at positions separated from the detection target space 10R by the light shielding member. It is feasible.

  A compensation light source control unit 85 is provided for the compensation light source unit 81, and the level of the drive current supplied to the compensation light source unit 81 is controlled by the compensation light source unit 81. In this embodiment, the compensation light source controller 85 is provided outside the control IC 70. Here, the compensation light source control unit 85 corresponds to the compensation drive current setting unit 83 for setting the level of the drive current supplied to the compensation light source unit 81 and the lighting pattern in the detection light source 12. A lighting pattern control unit 88 for lighting the compensation light source 12S and the second compensation light source 12T is provided.

  The compensation drive current setting unit 83 sets a compensation drive current to be supplied to the first compensation light source 12S, and a compensation drive to be supplied to the second compensation light source 12T. A second compensation driving current setting unit 83T for setting a current, and the first compensation driving current setting unit 83S and the second compensation driving current setting unit 83T are provided in the upper control unit 60. It functions as a variable resistor whose resistance value is set by the compensation condition setting unit 57. Therefore, the compensation light source 81 (the first compensation light source 12S and the second compensation light source 12T) has a variable emission intensity of the compensation light L5.

  The lighting pattern control unit 88 includes switches 88S and 88T. In the first coordinate information detection period tx, the first compensation light source 12S and the second compensation light source 12T are synchronized with the detection light sources 12A and 12C. In the second coordinate information detection period ty, the first compensation light source 12S and the second compensation light source 12T are lit in synchronization with the detection light sources 12B and 12D. More specifically, in the first coordinate information detection period tx, the switches 88S and 88T conduct the power supply line for the detection light source 12A to the first compensation light source 12S via the first compensation drive current setting unit 83S. At the same time, the power supply line for the detection light source 12C is conducted to the second compensation light source 12T via the second compensation drive current setting unit 83T. Therefore, as shown in FIGS. 4A and 4B, when the detection light source 12A is turned on during the first operation in the first coordinate information detection period tx, the first compensation light source 12S includes the first compensation light source 12S. Since the current set by the drive current setting unit 83S is supplied, the detection light source 12A and the first compensation light source 12S are turned on simultaneously. Further, when the detection light source 12C is turned on during the second operation in the first coordinate information detection period tx, the current set by the second compensation drive current setting unit 83T is supplied to the second compensation light source 12T. Therefore, the detection light source 12C and the second compensation light source 12T are turned on simultaneously.

  In the lighting pattern control unit 88, the switches 88S and 88T are configured so that the first compensation light source 12S is connected to the detection light source 12B via the first compensation drive current setting unit 83S in the second coordinate information detection period ty. And the power supply line for the detection light source 12D is conducted to the second compensation light source 12T via the second compensation drive current setting unit 83T. Therefore, as shown in FIGS. 4A and 4B, when the detection light source 12B is turned on during the first operation in the second coordinate information detection period ty, the first compensation light source 12S includes the first compensation light source 12S. Since the current set by the drive current setting unit 83S is supplied, the detection light source 12B and the first compensation light source 12S are turned on simultaneously. When the detection light source 12D is turned on during the second operation in the second coordinate information detection period ty, the current set by the second compensation drive current setting unit 83T is supplied to the second compensation light source 12T. Therefore, the detection light source 12D and the second compensation light source 12T are turned on simultaneously.

  Therefore, as shown in FIG. 4D, the second light receiving unit 32 receives the first compensation light emitted from the first compensation light source 12S during the first operation in the first coordinate information detection period tx, During the second operation, the second compensation light emitted from the second compensation light source 12T is received. The second light receiving unit 32 receives the first compensation light emitted from the first compensation light source 12S during the first operation in the second coordinate information detection period ty, and receives the second compensation light source during the second operation. The second compensation light emitted from 12T is received.

(Configuration of second light receiving unit 32 and the like)
Referring again to FIG. 1, in the optical position detection device 10 of the present embodiment, the first light receiving unit 31 and the second light receiving unit 32 are both photodiodes (photoelectric conversion elements), and the first light receiving unit 31 and the second light receiving unit. 32 is electrically connected in parallel with a reverse polarity. Two connection points of the first light receiving unit 31 and the second light receiving unit 32 are electrically connected to the differential amplifier 72 of the position detecting unit 50. That is, the connection point between the anode of the first light receiving unit 31 and the cathode of the second light receiving unit 32 is electrically connected to one input terminal of the differential amplifier 72, and the cathode node of the first light receiving unit 31 and the second light receiving unit are connected. A connection point of 32 anodes is electrically connected to the differential amplifier 72. Therefore, the difference between the detection intensity at the first light receiving unit 31 and the detection intensity at the second light receiving unit 32 is input to the differential amplifier 72.

  For this reason, when detecting the position of the target object Ob based on the above principle, the received light amount measuring unit 73 of the position detecting unit 50 receives the received light intensity and the first light intensity at the first light receiving unit 31 as shown in FIG. The difference between the received light intensity of the two light receiving units 32 is detected as the amount of received light. Therefore, in the first coordinate information detection period tx, the adjustment amount calculation unit 74 of the position detection unit 50 determines that the difference between the light reception intensity at the first light reception unit 31 and the light reception intensity at the second light reception unit 32 is the first operation. The control amounts (drive currents) for the detection light sources 12A and 12C are adjusted so as to be equal to those in the second operation. Further, the adjustment amount calculation unit 74 determines that the difference between the light receiving intensity at the first light receiving unit 31 and the light receiving intensity at the second light receiving unit 32 is the first operation and the second operation in the second coordinate information detection period ty. The control amounts (drive currents) for the detection light sources 12B and 12D are adjusted to be equal to each other. Therefore, the coordinate acquisition unit 55 of the position detection unit 50 determines that the difference between the light reception intensity at the first light reception unit 31 and the light reception intensity at the second light reception unit 32 during the first operation in the first coordinate information detection period tx. Therefore, the contour line is obtained based on the result of adjusting the control amounts (drive currents) for the detection light sources 12A and 12C so as to be equal in the second operation. Further, the coordinate acquisition unit 55 determines that the difference between the light reception intensity at the first light receiving unit 31 and the light reception intensity at the second light receiving unit 32 during the second coordinate information detection period ty is the first operation and the second operation. The contour lines are obtained based on the results of adjusting the control amounts (drive currents) for the detection light sources 12B and 12D so as to be equal to each other. And the coordinate acquisition part 55 makes the position equivalent to the intersection of the isoline calculated in the 1st coordinate information detection period tx and the isoline calculated in the 2nd coordinate information detection period ty the position of the target object Ob. Will be identified.

  A high-pass filter 35 using a capacitor, a resistor, and the like is inserted between a connection point between the first light receiving unit 31 and the second light receiving unit 32 and the differential amplifier 72. For this reason, a high-frequency signal is input to the differential amplifier 72, and a low-frequency signal caused by ambient light such as external light is removed. Therefore, when detecting the position of the target object Ob, the influence of ambient light such as external light can be excluded.

(Compensation operation by the compensation light source unit 81 and the second light receiving unit 32)
In the optical position detection device 10 of the present embodiment, detection is performed under the control of the control unit 60 before the operation described with reference to FIG. 4 is started or during the operation described with reference to FIG. The following operations are executed in a state where the target object Ob does not exist in the target space 10R.

  First, the light source driving unit 51 sequentially supplies reference driving pulses to the detection light sources 12A, 12B, 12C, and 12D, and sequentially turns on the detection light sources 12A, 12B, 12C, and 12D. Meanwhile, the compensation light source control unit 85 stops power supply to the compensation light source unit 81 (the first compensation light source 12S and the second compensation light source 12T). Therefore, when the detection light source 12A is turned on, the light reception intensity at the first light receiving unit 31 is the light reception intensity of the detection light L2a reflected by the object Sb other than the target object Ob, and the result is a higher-level control unit. 60 is temporarily stored in the compensation condition setting unit 57 provided at 60. Next, when the detection light source 12B is turned on, the light reception intensity at the first light receiving unit 31 is the light reception intensity of the detection light L2b reflected by the object Sb other than the target object Ob, and this result is obtained by the upper control. Temporarily stored in the compensation condition setting unit 57 provided in the unit 60. Next, when the detection light source 12C is turned on, the light reception intensity at the first light receiving unit 31 is the light reception intensity of the detection light L2c reflected by the object Sb other than the target object Ob. Temporarily stored in the compensation condition setting unit 57 provided in the unit 60. Next, when the light source 12D for detection is turned on, the light reception intensity at the first light receiving unit 31 is the light reception intensity of the detection light L2d reflected by the object Sb other than the target object Ob, and the result is a higher-level control. Temporarily stored in the compensation condition setting unit 57 provided in the unit 60.

  Then, before performing the detection operation described with reference to FIG. 4, the compensation condition setting unit 57 performs the compensation light source unit 81 (first compensation light source) when the detection light sources 12A, 12B, 12C, and 12D are turned on. The drive current value to be supplied to the light source 12S and the second compensation light source 12T) is commanded to the compensation drive current setting unit 83. As a result, in the compensation drive current setting unit 83, the first compensation drive current setting unit 83S includes the drive current supplied to the detection light source 12 that emits the detection light L2 during the first operation, and the first compensation light source. The ratio of the drive current supplied to 12S is set, and the second compensation drive current setting unit 83T sets the drive current supplied to the detection light source 12 that emits the detection light L2 during the second operation and the second compensation. A ratio to the drive current supplied to the light source 12T is set.

  Here, the ratios set in the first compensation drive current setting unit 83S and the second compensation drive current setting unit 83T are other than the target object Ob when the detection light sources 12A, 12B, 12C, and 12D are sequentially turned on. The light source 81 for compensation (first compensation light source 81) so that the received light intensity of the detection light L4 reflected by the object Sb at the first light receiving part 31 is equal to the received light intensity of the compensation light L5 at the second light receiving part 32. It is a value that defines the emission intensity of the compensation light L5 emitted from the light source 12S and the second compensation light source 12T). Therefore, the received light amount measurement unit 73 measures a true value excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob (the received light intensity of the detection light L3 reflected by the target object Ob). become.

  More specifically, during the first operation in the first coordinate information detection period tx, the first compensation drive current setting unit 83S is reflected by an object Sb other than the target object Ob when the detection light source 12A is turned on. The compensation light L5 emitted from the first compensation light source 12S so that the received light intensity of the detected light L4 at the first light receiving unit 31 and the received light intensity of the compensation light L5 at the second light receiving unit 32 are equal. A value (ratio) that defines the strength is set. In addition, when the detection light source 12A is turned on during the first operation in the first coordinate information detection period tx, the first compensation light source 12S is also turned on. Therefore, the received light amount measurement unit 73 measures the true value (the received light intensity of the detection light L3 reflected by the target object Ob) excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob. Become.

  Further, during the second operation in the first coordinate information detection period tx, the second compensation drive current setting unit 83S has the detection light L4 reflected by the object Sb other than the target object Ob when the detection light source 12C is turned on. The emission intensity of the compensation light L5 emitted from the second compensation light source 12T is defined so that the received light intensity at the first light receiving part 31 is equal to the received light intensity of the compensation light L5 at the second light receiving part 32. A value (ratio) is set. In addition, when the detection light source 12C is turned on during the second operation in the first coordinate information detection period tx, the second compensation light source 12T is also turned on. Therefore, the received light amount measurement unit 73 measures the true value (the received light intensity of the detection light L3 reflected by the target object Ob) excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob. Become.

  Further, the second coordinate information detection period ty is the same as the first coordinate information detection period tx. That is, during the first operation in the second coordinate information detection period ty, the first compensation drive current setting unit 83S has the detection light L4 reflected by the object Sb other than the target object Ob when the detection light source 12B is turned on. The emission intensity of the compensation light L5 emitted from the first compensation light source 12S is defined so that the received light intensity at the first light receiving part 31 and the received light intensity of the compensation light L5 at the second light receiving part 32 are equal. A value (ratio) is set. In addition, when the detection light source 12B is turned on during the first operation in the second coordinate information detection period ty, the first compensation light source 12S is also turned on. Therefore, the received light amount measurement unit 73 measures the true value (the received light intensity of the detection light L3 reflected by the target object Ob) excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob. Become. Further, during the second operation in the second coordinate information detection period ty, the second compensation drive current setting unit 83S has the detection light L4 reflected by the object Sb other than the target object Ob when the detection light source 12D is turned on. The emission intensity of the compensation light L5 emitted from the second compensation light source 12T is defined so that the received light intensity at the first light receiving part 31 is equal to the received light intensity of the compensation light L5 at the second light receiving part 32. A value (ratio) is set. Moreover, when the detection light source 12D is turned on during the second operation in the second coordinate information detection period ty, the second compensation light source 12T is also turned on. Therefore, the received light amount measurement unit 73 measures the true value (the received light intensity of the detection light L3 reflected by the target object Ob) excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob. Become.

  In performing the above compensation operation, the light source driving unit 51 supplies power to the detection light source 12 and the drive current supplied to the detection light source 12 at a ratio set in the compensation drive current setting unit 83. The drive current having the converted current value is supplied to the compensation light source unit 81. Accordingly, when the drive current value supplied to the detection light sources 12A, 12B, 12C, and 12D changes during the above-described differential, the first compensation light source 12S and the second compensation light source 12T are interlocked with the change. The current value supplied to automatically changes. Therefore, the received light amount measurement unit 73 always measures a true value excluding the received light intensity of the detection light L4 reflected by the object Sb other than the target object Ob (the received light intensity of the detection light L3 reflected by the target object Ob). Will do.

(Main effects of this form)
As described above, in the optical position detection device 10 of the present embodiment, the plurality of detection light sources 12 that emit the detection light L2 are used, and when the plurality of detection light sources 12 are sequentially turned on, the first light receiving unit. 31 receives the detection light L3 reflected by the target object Ob. Therefore, if the detection result of the first light receiving unit 31 is directly used, or the driving condition such as the driving current value when the light sources for detection 12 are differentiated based on the received light intensity of the first light receiving unit 31 is used. For example, the position of the target object Ob can be detected.

  Here, in addition to the detection light L3 reflected by the target object Ob, the detection light L4 reflected by the object Sb other than the target object Ob may be incident on the first light receiving unit 31. A compensation light source unit 81 that emits the compensation light L5 that is not incident on the space 10R and a second light receiving unit 32 that receives the compensation light L5 without receiving the detection lights L2, L3, and L4 are provided. Therefore, if the received light intensity of the compensation light L5 at the second light receiving unit 32 is set to the received light intensity at the first light receiving unit 31 of the detection light L4 reflected by the object Sb other than the target object Ob, the position detecting unit. 50, when the position of the target object Ob is detected based on the difference between the received light intensity at the first light receiving unit 31 and the received light intensity at the second light receiving unit 32, the detection result includes an object other than the target object Ob. The influence of the detection light L4 reflected by Sb is automatically removed. Therefore, the position of the target object Ob can be detected without being affected by the detection light L4 reflected by the object Sb other than the target object Ob.

  Further, in the present embodiment, the light source driving unit 51 performs the first operation of emitting the detection light L2 from some of the detection light sources 12 among the plurality of detection light sources 12, and the other part of the detection light sources 12. Even when the second operation of emitting the detection light L2 is executed, the position detection unit 50 is configured such that the difference between the received light intensity at the first light receiving unit 31 and the received light intensity at the second light receiving unit 32 during the first operation, Further, the position of the target object Ob is detected based on the difference between the received light intensity at the first light receiving unit 31 and the received light intensity at the second light receiving unit 32 during the second operation. Therefore, even when the detection principle using the first operation and the second operation is adopted, the position of the target object Ob can be detected without being affected by the detection light reflected by the object Sb other than the target object Ob. it can.

  In the present embodiment, the position detection unit 50 changes the emission intensity of the compensation light L5 in the first operation in conjunction with the emission intensity of the detection light L2 emitted from the detection light source 12 during the first operation. During the second operation, it changes in conjunction with the emission intensity of the detection light L2 emitted from the detection light source 12 in the second operation. Therefore, the difference between the received light intensity at the first light receiving unit 31 and the received light intensity at the second light receiving unit 32 during the first operation, and the received light intensity at the first light receiving unit 31 during the second operation and the second light receiving unit. Even when the detection principle of differentiating the detection light source 12 so that the difference in received light intensity at 32 is equal, the target object is not affected by the detection light reflected by the object Sb other than the target object Ob. The position of Ob can be detected.

  In this embodiment, since the common light source driving unit 51 supplies power to the detection light source 12 and the compensation light source unit 81, the circuit configuration can be simplified. Further, since the detection light source 12 and the compensation light source unit 81 are driven by the common light source drive unit 51, it is possible to cope with a change in drive current supplied to the detection light source 12 when the detection light sources 12 are differentiated. Thus, it is easy to change the emission intensity of the compensation light L5 emitted from the compensation light source unit 81.

  In addition, in this embodiment, the compensation drive current setting unit 83 is a ratio of the drive current supplied to the detection light source 12 that emits the detection light L2 during the first operation and the drive current supplied to the compensation light source unit 81, The ratio of the drive current supplied to the detection light source 12 that emits the detection light L2 during the second operation and the drive current supplied to the compensation light source unit 81 is defined. For this reason, the detection light L2 emitted from the detection light source 12 during the first operation is reflected by the object Sb other than the target object Ob and incident on the first light receiving unit 31, and the detection light source 12 from the detection light source 12 during the second operation. Even when the emitted detection light L2 is reflected by the object Sb other than the target object Ob and the amount of light incident on the first light receiving unit 31 is different, the reflected light is reflected by the object Sb other than the target object Ob and the first light receiving unit. The influence of the detection light L4 incident on 31 can be appropriately excluded.

  The compensation light source unit 81 emits the first compensation light as the compensation light L5 during the first operation, and the second compensation light emits the second compensation light as the compensation light L5 during the second operation. Therefore, it is easy to emit the compensation light L5 having an appropriate intensity during the first operation and the second operation.

  Further, the first light receiving unit 31 is a photodiode (first photoelectric conversion element), and the second light receiving unit 32 is parallel to the first light receiving unit 31 (photodiode / first photoelectric conversion element) with a reverse polarity. This is an electrically connected photodiode (second photoelectric conversion element). For this reason, the difference between the received light intensity at the first light receiving part 31 and the received light intensity at the second light receiving part 32 is output from the connection point between the first light receiving part 31 and the second light receiving part 32. The difference between the received light intensity at 31 and the received light intensity at the second light receiving unit 32 can be easily output.

  Furthermore, in this embodiment, the compensation light source control unit 85 and the lighting pattern control unit 88 are provided outside the control IC 70. For this reason, the configuration of the control IC 70 is the same in both cases where the detection light L4 reflected by the object Sb other than the target object Ob and incident on the first light receiving unit 31 is compensated, and when it is not compensated. Therefore, even when the detection light L4 reflected by the object Sb and incident on the first light receiving unit 31 is compensated, the detection light L4 reflected by the object Sb and incident on the first light receiving unit 31 is not compensated. There is an advantage that the control IC 70 can be used as it is, and there is no need to change the design of the control IC 70.

[Embodiment 2]
FIG. 5 is an explanatory diagram schematically showing the overall configuration of the optical position detection device according to the second embodiment of the present invention. Note that the basic configuration of the present embodiment is substantially the same as that of the first embodiment, and therefore, common portions are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 5, the optical position detection device 10 of the present embodiment also has a plurality of detection light sources 12 that emit detection light L2 and a light source drive that drives the plurality of detection light sources 12, as in the first embodiment. Unit 51, first light receiving unit 31 that receives detection light L3 reflected by a target object located in the emission space (detection target space 10R) of detection light L2, and a target based on the detection result of first light receiving unit 31 And a position detection unit 50 that detects the position of the object Ob. Further, as in the first embodiment, the optical position detection device 10 emits the compensation light L5 that does not enter the detection target space 10R (the first compensation light source 12S and the second compensation light source 12T). And the second light receiving unit that receives the compensation light L5 emitted from the compensation light source unit 81 without receiving the detection light L3 reflected by the target object Ob or the detection light L4 reflected by the object Sb other than the target object Ob. 32.

  In the optical position detection device 10 having such a configuration, in the first embodiment, photodiodes that are electrically connected in parallel with opposite polarities are used as the first light receiving unit 31 and the second light receiving unit 32. In this embodiment, the first light receiving unit 31 and the second light receiving unit 32 are provided with amplifiers 33 and 34, and the amplifiers 33 and 34 are electrically connected to the differential amplifier 72. That is, the amplifier 33 provided for the first light receiving unit 31 is electrically connected to one input terminal of the differential amplifier 72, and the amplifier 34 provided for the second light receiving unit 32 is differentially connected. The other input terminal of the amplifier 72 is electrically connected. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Therefore, also in the optical position detection device 10 of the present embodiment, the position detection unit 50 detects the difference between the light reception intensity at the first light reception unit 31 and the light reception intensity at the second light reception unit 32 as in the first embodiment. Based on this, the position of the target object Ob is detected. Therefore, in this embodiment as well, the influence of the detection light L4 reflected by the object Sb other than the target object Ob can be removed, so that the target object is not affected by the detection light L4 reflected by the object Sb other than the target object Ob. The same effects as those of the first embodiment can be obtained, such as being able to detect the position of Ob.

[Modification Example of Embodiments 1 and 2: Configuration Example Using Reference Light Source]
FIG. 6 is an explanatory diagram illustrating a configuration example in the case where a reference light source is used in the optical position detection device 10 according to Embodiments 1 and 2 of the present invention, and FIGS. It is explanatory drawing which shows three-dimensional layouts, such as a light source for detection, and explanatory drawing which shows planar layouts, such as a light source for detection. In addition, since the basic structure of this form is the same as that of the form demonstrated with reference to FIGS. 1-5, the same code | symbol is attached | subjected to a common part and those description is abbreviate | omitted.

  As shown in FIG. 6, the optical position detection device 10 of the present embodiment also has a plurality of detection light sources 12 that emit detection light L2 and an emission space of the detection light L2 (detection target space 10R), as in the first embodiment. And a first light receiving unit 31 that receives the detection light L3 reflected by the target object located at the position.

  In the optical position detection device 10 of the present embodiment, a reference light source 12R having a light emitting portion directed to the first light receiving unit 31 is provided, and the reference light source 12R is similar to the detection light source 12 and see FIG. It is comprised by LED (light emitting diode) etc. which are driven by IC70 for control demonstrated above. However, the reference light Lr emitted from the reference light source 12R is on the side of the visual recognition surface 41 of the visual recognition surface component 40 due to the orientation of the reference light source 12R, a light shielding cover (not shown) provided on the reference light source 12R, and the like. The light does not enter the (detection target space 10R) and enters the first light receiving unit 31 without passing through the detection target space 10R.

In the optical position detection device 10 of the present embodiment, instead of direct differential between the detection lights L2, the differential between the detection light L2 and the reference light Lr is used, and finally the detection lights L2 are combined. A result similar to that obtained by direct differential is derived. This detection principle is mathematically explained using an optical path function as follows. First, the detection light L2a emitted each parameter from the reflectance A _t = detection light sources 12A below T = target object Ob by the target object Ob
A distance function that reflects and reaches the first light receiving unit 31 A = detection light source 12A in a state where the target object Ob exists in the detection target space 10R
Detected intensity C _t of the first light receiving unit 31 when is illuminated C _t = the detection light L2c emitted from the detection light source 12C is the target object Ob
Distance function that reflects and reaches the first light receiving unit 31 C = Detection light source 12C in a state where the target object Ob exists in the detection target space 10R
Detection intensity R _s of the first light receiving unit 31 when is lit R = distance function from the reference light source 12R to the first light receiving unit 31 R = detection of the first light receiving unit 31 when only the reference light source 12R is lit Strength. Note that the light emission intensities of the detection light source 12A, the detection light source 12C, and the reference light source 12R are represented by the product of the drive current and the light emission coefficient. In the following description, the light emission coefficient is 1. In the above-described differential, the driving current for the detection light source 12A when the received light intensity at the first light receiving unit 31 becomes equal is I _A , the driving current for the detection light source 12C is I _C , and the reference light source The drive current for 12R is I _R. In addition, in the differential operation, the detection intensity of the first light receiving unit 31 when only the reference light source 12R is lit is assumed to be the same in the differential with the detection light source 12A and the differential with the detection light source 12C. To do.

When the above-described differential is performed in a state where the target object Ob exists in the detection target space 10R,
A = T × A _t × I _A + Ambient Light ・ ・ Formula (6)
C = T × C _t × I _C + Ambient Light ・ ・ Formula (7)
R = R _s × I _R + Ambient Light ・ ・ Formula (8)
The relationship is obtained.

Here, since the detection intensity of the first light receiving unit 31 at the time of differential is equal, from the formulas (6) and (8), the following formula T × A _t × I _A + ambient light = R _s × I _R + environment Light T × A _t × I _A = R _s × I _R
T × A _t = R _s × I _R / I _A ... (9)
From the formulas (7) and (8), the following formula T × C _t × I _C + environment light = R _s × I _R + environment light T × C _t × I _C = R _s × I _R
T × C _t = R _s × I _R / I _C ... (10)
Is guided.

The distance function A _t, the ratio P _AC of C _t is the formula _{P AC = A t / C t} ·· formula (11)
Therefore, from the equations (9) and (10), the ratio P _{AC of the} distance function is P _AC = I _C / I _A ··· Equation (12)
It is expressed as In this equation (12), there is no term of ambient light. Note that the mathematical model described above may be corrected to cancel the influence of the detection light L2 that has entered without being reflected by the target object Ob. Even when the detection intensity of the first light receiving unit 31 when only the reference light source 12R is lit is set to a different value between the differential with the detection light source 12A and the differential with the detection light source 12C, Basically the same principle holds.

Here, the detection light source 12 is a point light source, and the light intensity at a certain point is inversely proportional to the square of the distance from the light source. Therefore, the ratio of the separation distance P1 from the detection light source 12A through the target object Ob to the first light receiving unit 31 and the separation distance P2 from the detection light source 12C through the target object Ob to the first light receiving unit 31 is as follows: Formula P _AC = (P1) ² : (P2) ²
Is required. Therefore, an isoline corresponding to the ratio P1: P2 can be set on the basis of the detection light source 12A and the detection light source 12C in the XY plane, and the target object Ob is positioned on the isoline.

  Similarly, if the detection light source 12B and the detection light source 12D are differentiated to obtain the ratio of the distance between the detection light source 12B and the target object Ob and the distance between the detection light source 12D and the target object Ob, XY An isoline can be set on the basis of the detection light source 12B and the detection light source 12D in the plane, and the target object Ob is positioned on the isoline.

  Therefore, if the intersection of the isoline obtained by the differential between the detection light source 12A and the detection light source 12C and the isoline obtained by the differential between the detection light source 12B and the detection light source 12D is obtained, The position (XY coordinate) of the object Ob can be obtained. According to such a configuration, since the differential between the detection light source 12 and the reference light source 12R is used, the influence of ambient light or the like can be automatically corrected.

  Even in the optical position detection apparatus 10 having such a configuration, as in the first and second embodiments, the compensation light source unit 81 that emits the compensation light L5 that is not incident on the detection target space 10R and the detection lights L2, L3, and L4 are received. If the second light receiving unit 32 that receives the compensation light L5 is used, the position of the target object Ob can be detected without being affected by the detection light L4 reflected by the object Sb other than the target object Ob.

[Other Embodiments]
In the first and second embodiments, the compensation light source control unit 85 and the lighting pattern control unit 88 are provided outside the control IC 70. However, the compensation light source control unit 85 and the lighting pattern control unit 88 are configured in the control IC 70. May be.

  In the first and second embodiments, the second light receiving unit 32 receives the detection light L3 reflected by the target object Ob, the detection light L4 reflected by the object Sb other than the target object Ob, and ambient light such as external light. However, the second light receiving unit 32 may be configured to receive ambient light such as external light under the same conditions as the first light receiving unit 31. . According to this configuration, when the difference between the received light intensity at the first light receiving unit 31 and the received light intensity at the second light receiving unit 32 is obtained, the difference is such that the detection light L4 reflected by the object Sb other than the target object Ob. And the value excluding the influence of ambient light such as external light. Therefore, the position of the target object Ob can be detected without being affected by the detection light L4 reflected by the object Sb other than the target object Ob and the ambient light such as outside light.

[Application example to other position detection methods]
The configuration using the compensation light source unit 81 that emits the compensation light L5 that does not enter the detection target space 10R and the second light receiving unit 32 that receives the compensation light L5 without receiving the detection lights L2, L3, and L4 are as described above. In addition to the optical position detection apparatus 10 that employs this position detection method, the present invention can also be applied to the optical position detection apparatus 10 that employs the method described with reference to FIGS.

[Another configuration example 1 of the optical position detection apparatus 10]
FIG. 7 is an explanatory diagram showing a main part of an optical position detection device 10 according to another configuration example 1 of the present invention. FIG. 8 is an explanatory diagram of detection light used in the optical position detection device 10 according to another configuration example 1 of the present invention. FIGS. 8A, 8B, and 8C are reflected by the target object. Is a plan view showing how the received light is received by the light receiving unit, a cross sectional view showing how the light reflected by the target object is received by the light receiving unit, and attenuation of the detection light in the light guide plate It is explanatory drawing which shows a state. Since the basic configuration of this embodiment is substantially the same as that of Embodiments 1 and 2, common portions are denoted by the same reference numerals and description thereof is omitted. In the following description, illustration and description of the compensation light source unit 81, the second light receiving unit 32, and the reference light source 12R are omitted.

(overall structure)
As shown in FIGS. 7 and 8, the optical position detection device 10 of the present embodiment is emitted from a plurality of detection light sources 12 (detection light sources 12 </ b> A to 12 </ b> D) that emit detection light L <b> 2 and the detection light source 12. And a first light receiving unit 31 that detects a part of the detection light L3 reflected by the target object Ob in the detection target space 10R (the detection light L2 emission space).

  Further, the optical position detection device 10 of this embodiment includes a light guide plate 13 made of a transparent resin plate such as polycarbonate or acrylic resin, and the detection light L2 emitted from the light source for detection 12 is the light guide plate 13. Is emitted to the detection target space 10R. The light guide plate 13 has a substantially rectangular planar shape, and a surface of the light guide plate 13 facing the detection target space 10R is a light emitting surface 13s. Further, the four corner portions 13 a to 13 d of the light guide plate 13 are used as light incident portions 13 e to 13 h for the detection light L <b> 2 emitted from the detection light source 12. More specifically, the four detection light sources 12 (detection light sources 12 </ b> A to 12 </ b> D) have light emitting surfaces facing the corner portions 13 a to 13 d at positions facing the corner portions 13 a to 13 d of the light guide plate 13. For this reason, the detection light L <b> 2 emitted from the detection light source 12 is incident from the corner portions 13 a to 13 d of the light guide plate 13, and then is emitted from the light emission surface 13 s while propagating through the light guide plate 13. For example, the detection light L <b> 2 a emitted from the detection light source 12 </ b> A is emitted from the light emission surface 13 s while propagating inside the light guide plate 13. Therefore, when the detection light L2 emitted from the light emission surface 13s of the light guide plate 13 to the detection target space 10R is reflected by the target object Ob located in the detection target space 10R, the detection light L3 reflected by the target object Ob is the first. It is detected by the light receiving unit 31.

  Here, a surface uneven structure, a prism structure, a scattering layer (not shown), and the like are provided on the back surface 13t or the light emitting surface 13s of the light guide plate 13, and the corner portions 13a to 13a are formed by such a light scattering structure. The light that enters from 13d and propagates inside is gradually deflected as it travels in the propagation direction, and is emitted from the light exit surface 13s. In addition, an optical sheet such as a prism sheet or a light scattering plate may be disposed on the light exit side of the light guide plate 13 in order to level the detection lights L2a to L2d as necessary. For this reason, the light quantity of the detection light L2a emitted to the detection target space 10R linearly attenuates with the distance from the detection light source 12A, as shown by a solid line in FIG. Further, the amount of the detection light L2b emitted to the detection target space 10R linearly attenuates with the distance from the detection light source 12B, as indicated by a dotted line in FIG. 8C. Similarly, the detection lights L2c and L2d emitted from the other detection light sources 12C and 12D are emitted from the light emission surface 13s while being attenuated. Therefore, the detection light L2 forms a light intensity distribution described later with reference to FIG. 10 in the detection target space 10R.

  The first light receiving unit 31 includes a photoelectric conversion element such as a photodiode or a phototransistor, and the light receiving unit is directed to the detection target space 10R at a substantially central position of the side portion of the light guide plate 13 outside the detection target space 10R. Yes.

(Position detection operation)
FIG. 9 shows a state in which a light intensity distribution is formed by sequentially lighting the detection light sources 12 (detection light sources 12A to 12D) in a predetermined pattern in the optical position detection device 10 according to another configuration example 1 of the present invention. It is explanatory drawing shown. FIG. 10 is an explanatory diagram showing a state in which a light intensity distribution for coordinate detection is formed by the detection light L2 emitted from the detection light source 12 in the optical position detection device 10 according to another configuration example 1 of the present invention. It is. In FIG. 10, the light source 12 for detection that is turned on is shown in gray. FIG. 11 is an explanatory diagram schematically showing the position detection principle in the optical position detection device 10 according to another configuration example 1 of the present invention. FIGS. 11A and 11B are reflected by the target object. It is explanatory drawing which shows the intensity | strength of the detected light, and explanatory drawing which shows a mode that the light intensity distribution of detection light is adjusted so that the intensity | strength of the detection light reflected by the target object may become equal.

  In the optical position detection device 10 of the present embodiment, when the detection light source 12A is turned on and the other detection light sources 12B to 12D are turned off, the detection target space 10R has one side X1 in the X-axis direction and A light intensity distribution centering on the corner portion on one side Y1 in the Y-axis direction is formed. When the detection light source 12B is turned on while the other detection light sources 12A, 12C, and 12D are turned off, the detection target space 10R has corners on the other side X2 in the X-axis direction and the other side Y2 in the Y-axis direction. A light intensity distribution centering on the portion is formed. When the detection light source 12C is turned on while the other detection light sources 12A, 12B, and 12D are turned off, the detection target space 10R has an angle on the other side X2 in the X-axis direction and one side Y1 in the Y-axis direction. A light intensity distribution centering on the portion is formed. When the detection light source 12D is turned on and the other detection light sources 12A to 12C are turned off, the detection target space 10R has corners on one side X1 in the X-axis direction and the other side Y2 in the Y-axis direction. A central light intensity distribution is formed.

  Therefore, as shown in FIG. 9A, when the detection light sources 12A and 12D are in the on state and the other detection light sources 12A and 12B are in the off state in the first operation of the first coordinate information detection period, As shown in FIG. 10A, the X-coordinate detection first light intensity distribution L2Xa (first coordinate detection first first) in which the intensity of the detection light monotonously decreases from one side X1 in the X-axis direction toward the other side X2. Light intensity distribution) is formed. In this embodiment, in the first light intensity distribution L2Xa for X coordinate detection, the intensity of the detection light L2 linearly decreases from one side X1 in the X-axis direction to the other side X2, and detection is performed in the Y-axis direction. The intensity of the light L2 is constant.

  On the other hand, as shown in FIG. 9B, in the second operation in the first coordinate information detection period, the detection light sources 12B and 12C are in the on state and the other detection light sources 12A and 12D are in the off state. If so, as shown in FIG. 10B, the X-coordinate detection second light intensity distribution L2Xb (first coordinate detection) in which the intensity of the detection light monotonously decreases from the other side X2 in the X-axis direction toward the one side X1. Second light intensity distribution) is formed. In this embodiment, in the X-coordinate detection second light intensity distribution L2Xb, the intensity of the detection light L2 linearly decreases from the other side X2 in the X-axis direction toward the one side X1, and in the Y-axis direction, the detection is performed. The intensity of the light L2 is constant.

  Further, as shown in FIG. 9C, when the detection light sources 12A and 12C are in the on state and the other detection light sources 12B and 12D are in the off state in the first operation of the second coordinate information detection period, As shown in FIG. 10 (c), the Y-coordinate detection first light intensity distribution L2Ya (second-coordinate detection first L1Ya) in which the intensity of the detection light monotonously decreases from one side Y1 in the Y-axis direction toward the other side Y2. Light intensity distribution) is formed. In the present embodiment, in the first light intensity distribution L2Ya for Y-coordinate detection, the intensity of the detection light L2 decreases linearly from one side Y1 in the Y-axis direction to the other side Y2, and in the X-axis direction, detection is performed. The intensity of the light L2 is constant.

  On the other hand, as shown in FIG. 9D, in the second operation in the second coordinate information detection period, the detection light sources 12B and 12D are in the on state and the other detection light sources 12A and 12C are in the off state. If there is, as shown in FIG. 10 (d), the Y-coordinate detection second light intensity distribution L2Yb (second coordinate detection) in which the intensity of the detection light monotonously decreases from the other side Y2 in the Y-axis direction toward the one side Y1. Second light intensity distribution) is formed. In this embodiment, in the second light intensity distribution L2Yb for Y-coordinate detection, the intensity of the detection light L2 linearly decreases from the other side Y2 in the Y-axis direction toward the one side Y1, and in the X-axis direction, the detection is performed. The intensity of the light L2 is constant.

  In the optical position detection device 10 of this embodiment, the detection light source 12 for forming the light intensity distribution is turned on to form the light intensity distribution of the detection light L2 in the detection target space 10R, and the detection reflected by the target object Ob. The light L2 is detected by the first light receiving unit 31, and the position detection unit 50 detects the position of the target object Ob in the detection target space 10R based on the detection result of the first light receiving unit 31. Therefore, the principle of coordinate detection will be described with reference to FIG.

  In the optical position detection apparatus 10 of the present embodiment, the X-coordinate detection first light intensity distribution L2Xa and the X-coordinate detection second light intensity distribution L2Xb described with reference to FIGS. 10A and 10B are used. Then, the position in the X axis direction (X coordinate) is detected. At that time, the detection light sources 12A and 12D and the detection light sources 12B and 12C are driven in opposite phases. More specifically, in the first operation in the first coordinate detection period, the detection light sources 12A and 12D are turned on, while the detection light sources 12B and 12C are turned off, and the X coordinate detection second shown in FIG. One light intensity distribution L2Xa is formed. Next, in the second operation in the first coordinate detection period, the detection light sources 12A and 12D are turned off, while the detection light sources 12B and 12C are turned on, and the second light intensity for X coordinate detection shown in FIG. A distribution L2Xb is formed. Therefore, when the target object Ob is arranged in the detection target space 10R, the detection light L2 is reflected by the target object Ob, and a part of the reflected light is detected by the first light receiving unit 31. Here, the first light intensity distribution L2Xa for X coordinate detection and the second light intensity distribution L2Xb for X coordinate detection have a constant distribution. Therefore, the position detection unit compares the detection intensity of the first light receiving unit 31 in the first X coordinate detection operation with the detection intensity of the first light reception unit 31 in the second X coordinate detection operation. The X coordinate of the target object Ob can be detected by the method described below with reference to FIG.

  First, as shown in FIG. 11A, in the first operation and the second operation in the first coordinate detection period, the X-coordinate detection first light intensity distribution L2Xa and the X-coordinate detection second light intensity distribution L2Xb are absolute values. Are equal to each other and are opposite to each other in the X-axis direction. In this state, if the detection value LXa in the first light receiving unit 31 during the first operation is equal to the detection value LXb in the first light receiving unit 31 during the second operation, the target object Ob is the center in the X-axis direction. You can see that it is located in

  On the other hand, when the detection value LXa in the first light receiving unit 31 during the first operation is different from the detection value LXb in the first light receiving unit 31 during the second operation, the detection values LXa and LXb The control amount (drive current) for the detection light source 12 is adjusted so as to be equal to each other, and as shown in FIG. 11 (b), the X-coordinate detection first light intensity distribution L2Xa is formed again, and the X-coordinate A second light intensity distribution for detection L2Xb is formed. Then, the detection value LXa in the first light receiving unit 31 during the first operation is made equal to the detection value LXb in the first light receiving unit 31 during the second operation. The X coordinate of the target object Ob is determined by the ratio or difference between the control amount (current value) for the detection light sources 12A and 12D and the control amount (current value) for the detection light sources 12A and 12D when the differential is performed. Can be detected. Further, the ratio or difference between the control amount adjustment amount ΔLXa for the detection light source 12 in the first operation for X coordinate detection and the control amount adjustment amount ΔLXb for the detection light source 12 in the second operation for X coordinate detection. Thus, the X coordinate of the target object Ob can be detected. According to such a method, even when ambient light other than the detection light L2, for example, an infrared component included in external light is incident on the first light receiving unit 31, the detection light sources 12 so that the detection values LXa and LXb are equal. When the control amount is adjusted, the intensity of the infrared component contained in the ambient light is canceled out, so that the infrared component contained in the ambient light does not affect the detection accuracy.

  In the optical position detection device 10 of the present embodiment, the first light intensity distribution L2Ya for Y coordinate detection and the second light intensity distribution L2Yb for Y coordinate detection described with reference to FIGS. 10 (c) and 10 (d). Is used to detect the position in the Y-axis direction (Y coordinate). More specifically, the detection light sources 12A and 12C and the detection light sources 12B and 12D are driven in opposite phases. That is, as shown in FIG. 9C, in the first operation in the second coordinate detection period, the detection light sources 12A and 12C are turned on, while the detection light sources 12B and 12D are turned off, and FIG. A first light intensity distribution L2Ya for Y coordinate detection shown in FIG. Next, in the second operation in the second coordinate detection period, as shown in FIG. 9D, the detection light sources 12A and 12C are turned off, while the detection light sources 12B and 12D are turned on, and FIG. The second light intensity distribution L2Yb for Y coordinate detection shown in FIG. Therefore, the position detection unit detects the X coordinate, such as comparing the detection value LYa of the first light receiving unit 31 during the first operation with the detection value LYb of the first light receiving unit 31 during the second operation. The Y coordinate of the target object Ob can be detected by a method similar to the method.

  Even in the optical position detection apparatus 10 having such a configuration, as in the first and second embodiments, the compensation light source unit 81 that emits the compensation light L5 that is not incident on the detection target space 10R and the detection lights L2, L3, and L4 are received. If the second light receiving unit 32 that receives the compensation light L5 is used, the position of the target object Ob can be detected without being affected by the detection light L4 reflected by the object Sb other than the target object Ob.

[Other Configuration Example 2 of Optical Position Detection Device]
FIG. 12 is an explanatory view schematically showing a main part of an optical position detection device 10 according to another configuration example 2 of the present invention. FIG. 13 is an explanatory diagram of two light source units constituting a light source unit in the optical position detection device 10 according to another configuration example 2 of the present invention. FIGS. 14A and 14B are explanatory views showing the position detection principle in the optical position detection device 10 according to another configuration example 2 of the present invention. FIGS. 14A and 14B are explanatory views of the light intensity distribution, and the target object. It is explanatory drawing of the method of acquiring the positional information (azimuth | direction information) in which there exists. FIG. 15 is an explanatory diagram illustrating a method of specifying the position of the target object Ob in the optical position detection device 10 according to another configuration example 2 of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1 and the like, common portions are denoted by the same reference numerals and description thereof is omitted. In the following description, illustration and description of the compensation light source unit 81, the second light receiving unit 32, and the reference light source 12R are omitted.

  12 and 13, the optical position detection device 10 of the present embodiment includes a plurality of light source modules 121 and 122 that emit detection light L2 in a semicircular direction, and detection light L2 emitted from the light source modules 121 and 122. Among these, the first light receiving unit 31 that detects a part of the detection light L3 reflected by the target object Ob is included. The light source modules 121 and 122 are disposed at the same position in the Z-axis direction, and each of the light source modules 121 and 122 emits detection light L2. In this embodiment, the detection target space 10R in which the position of the target object Ob is detected is configured by the emission space of the detection light L2. Here, the light source module 121 emits the detection light L2 radially in the first coordinate information detection period, and the light source module 122 sequentially emits the detection light L2 in the second coordinate information detection period. Therefore, the position detection unit 50 receives light intensity of the detection light L2 at the first light receiving unit 31 in the first coordinate information detection period and light reception intensity of the detection light L2 at the first light receiving unit 31 in the second coordinate information detection period. Based on this, the position of the target object Ob is detected.

  In adopting such a position detection method, in this embodiment, as shown in FIG. 12, the light source module 121 includes a detection light source unit 12E and a detection light source unit 12F that are arranged to overlap in the Y-axis direction. Similarly to the light source module 121, the module 122 includes a detection light source unit 12 </ b> E and a detection light source unit 12 </ b> F that are arranged in the Y-axis direction.

  Here, as shown in FIG. 13A, the detection light source unit 12E includes a detection light source 12A made of a light emitting element such as a light emitting diode that emits infrared light, and an arc-shaped light guide LG. The detection light source 12A is disposed at one end B3 of the light guide LG. The light source unit 12E for detection includes an arcuate irradiation direction setting unit LE including the optical sheet PS and the louver film LF along the arcuate outer peripheral surface of the light guide LG, and the arcuate shape of the light guide LG. An arc-shaped reflection sheet RS is provided along the inner peripheral surface.

  Further, as shown in FIG. 13B, the detection light source unit 12F is similar to the detection light source unit 12E, and includes a detection light source 12C made of a light emitting element such as a light emitting diode that emits infrared light, and an arcuate shape. The light source for detection 12C is disposed at the other end B4 of the light guide LG. Similarly to the detection light source unit 12E, the detection light source unit 12F 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 of the light guide LG. And an arcuate reflecting sheet RS is provided along the arcuate inner peripheral surface of the light guide LG.

  Note that at least one of the outer peripheral surface and the inner peripheral surface of the light guide LG is subjected to processing for adjusting the emission efficiency of the detection light from the light guide LG. A method for printing dots, a molding method for forming irregularities by a stamper or injection, or a groove processing method can be employed.

  In the optical position detection device 10 configured as described above, in the light source module 121, when the detection light source 12A is turned on in the detection light source unit 12E during the first operation in the first coordinate information detection period, the detection is performed in the detection target space 10R. The light L2 is emitted, and a 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 the other end B4 from an angular direction corresponding to the one end B3, as shown in FIG. It is an intensity distribution in which the intensity decreases monotonously toward the point.

  On the other hand, in the detection light source unit 12F, when the detection light source 12C is turned on during the second operation in the first coordinate information detection period, the detection light is emitted to the detection target space 10R and the second detection target space 10R is second. A light intensity distribution LID2 is formed. The second light intensity distribution LID2 is an angular direction corresponding to one end B3 from an angular direction corresponding to the other end B4, as shown in FIG. It is an intensity distribution in which the intensity decreases monotonously toward the point.

  In the light source module 122, the light source module 122 is in the first operation during the second coordinate information detection period, when the detection light source 12B is turned on in the detection light source unit 12E, and in the second operation in the second coordinate information detection period. When the detection light source 12D is turned on in the detection light source unit 12F, the first light intensity distribution LID1 and the second light intensity distribution LID2 are formed as in the light source module 121. Therefore, as described below, the position of the target object Ob can be detected by using the first light intensity distribution LID1 and the second light intensity distribution LID2.

  First, when the first light intensity distribution LID1 is formed in the detection light source unit 12E of the light source module 121, the irradiation direction of the detection light L2 and the intensity of the detection light L2 are indicated by a line E1 in FIG. There is a relationship. Further, when the second light intensity distribution LID2 is formed in the detection light source unit 12F of the light source module 121, the irradiation direction of the detection light L2 and the intensity of the detection light L2 are indicated by a line E2 in FIG. There is a relationship. Here, as shown in FIGS. 14B and 15, it is assumed that the target object Ob exists in the direction of the angle θ when viewed from the center PE of the light source module 121 (the center of the light source unit 12E for detection). In this case, when the first light intensity distribution LID1 is formed, the intensity of the detection light L2 at the position where the target object Ob is present is INTa. On the other hand, when the second light intensity distribution LID2 is formed, the intensity of the detection light L2 at the position where the target object Ob is present is INTb. Therefore, comparing the detection intensity at the first light receiving unit 31 when the first light intensity distribution LID1 is formed with the detection intensity at the first light receiving unit 31 when the second light intensity distribution LID2 is formed, If the relationship between the intensity INTa and INTb is obtained, the angle θ (angle θ1) in the direction in which the target object Ob is located can be obtained with reference to the center PE of the light source module 121.

  If such an operation is also performed in the light source module 122 to obtain the angle θ (angle θ2) in the direction in which the target object Ob is located, the distance DS of the center PE is constant. The position of the target object Ob can be specified.

  In adopting such a method, in this embodiment, in the light source module 121, the detection intensity at the first light receiving unit 31 when the first light intensity distribution LID1 is formed by the detection light source unit 12E and the detection light source unit 12F. Ratio of drive current when adjusting the drive current when driving the detection light sources 12A and 12C so that the detection intensity at the first light receiving unit 31 when the second light intensity distribution LID2 is formed is equal. To obtain the angle θ (angle θ1) in the direction in which the target object Ob is located. In the light source module 122, the detection intensity at the first light receiving unit 31 when the first light intensity distribution LID1 is formed by the detection light source unit 12E, and the second light intensity distribution LID2 is formed by the detection light source unit 12F. In the direction in which the target object Ob is positioned based on the ratio of the drive currents when the drive currents when the detection light sources 12B and 12D are driven are adjusted so that the detected intensities at the first light receiving unit 31 are equal. An angle θ (angle θ2) is obtained. Therefore, it can be seen that the target object Ob is located at the intersection of the directions defined by the angles θ1 and θ2.

  Even in the optical position detection apparatus 10 having such a configuration, as in the first and second embodiments, the compensation light source unit 81 that emits the compensation light L5 that is not incident on the detection target space 10R and the detection lights L2, L3, and L4 are received. If the second light receiving unit 32 that receives the compensation light L5 is used, the position of the target object Ob can be detected without being affected by the detection light L4 reflected by the object Sb other than the target object Ob.

[Specific example 1 of device 1 with position detection function]
With reference to FIG. 16, an example in which a screen is used as the viewing surface constituting member 40 of the device 1 with a position detection function and the device 1 with a position detection function is configured as a screen device with a position detection function will be described. FIG. 16 is an explanatory diagram of a screen device with a position detection function (apparatus 1 with a position detection function) to which the present invention is applied. FIGS. 16 (a) and 16 (b) show the screen device with a position detection function obliquely from above. It is explanatory drawing which shows a mode seen typically, and explanatory drawing which shows a mode seen from the horizontal direction typically. In the screen device with a position detection function of this embodiment, the configuration of the optical position detection device 10 is the same as the configuration described with reference to FIGS. A description thereof will be omitted.

  A screen device 8 with a position detection function shown in FIGS. 16A and 16B has a screen 80 (image generation device) on which an image is projected from a liquid crystal projector or a digital micromirror device. A viewing surface constituting member 40) and the optical position detection device 10 described with reference to FIGS. 1 to 6, and the image projection device 250 is a projection lens provided on the front surface 241 of the housing 240. The image display light Pi is enlarged and projected from the system 210 toward the screen device 8. Therefore, in the screen device 8 with a position detection function, the screen surface 8a onto which an image is projected on the screen 80 constitutes a viewing surface 41 on which information is visually recognized.

  In the screen device 8 with a position detection function, the optical position detection device 10 includes a plurality of detection light sources 12 that emit detection light L2 on the back surface 8b side of the screen 80. Therefore, the light source for detection 12 emits the detection light L2 to the detection target space 10R set on the viewing surface 41 side from the side opposite to the viewing surface 41 side on the screen 80 (viewing surface constituting member 40). . The first light receiving unit 31 is disposed on the back surface 8b side of the screen 80, and detects the detection light L3 that is reflected by the target object Ob and transmitted through the screen 80. Accordingly, the screen 80 having a light-transmitting property with respect to the detection light L2 is used. More specifically, the screen 80 is composed of a fabric with white paint applied to the screen surface 8a side or a white screen made of embossed white vinyl material, and is transparent to the detection light L2 made of infrared light. As the screen 80 having light, a silver screen made of high silver to increase the reflectance of light, a pearl whose resin surface is processed on the fabric surface constituting the screen surface 8a to increase the reflectance of light. A screen, a bead screen in which fine glass powder is applied to the screen surface 8a side to increase the reflectance of light, can be used. In such a case, the screen 80 can detect the detection light L2 made of infrared light. It has translucency. The screen 80 may be provided with a black light-shielding layer on the back surface 8b for the purpose of improving the quality of the displayed image. In such a case, the light-shielding layer has a light-transmitting portion made of a hole. A plurality of are formed.

  In the screen device 8 with the position detection function configured as described above, the detection target space 10R is a rectangular region when viewed from the normal direction with respect to the screen device 8, and an image is projected by the image projection device 250 on the screen device 8. It overlaps with the area (image display area 20R). For this reason, in the screen device 8 with a position detection function of the present embodiment, for example, if the target object Ob such as a fingertip is brought close to a part of the image projected on the screen 80, the position of the target object Ob is switched. It can be used as input information such as instructions.

  In the present embodiment, the screen device for a projection display device on which an image is projected from the image projection device 250 has been described as the screen device 8 with a position detection function. However, the optical position detection device 10 is applied to a screen for an electronic blackboard. May be provided to constitute a screen device with a position detection function for an electronic blackboard. In the configuration example shown in FIG. 16, the first light receiving unit 31 is arranged on the back surface 8 b side of the screen 80, but the first light receiving unit 31 is arranged on the front surface side (screen surface 8 a side) of the screen 80. It may be. Furthermore, the optical position detection device 10 described with reference to FIGS. 7 to 10 is arranged on the back surface 8b or the front surface side (screen surface 8a side) of the screen 80 to constitute the screen device 8 with a position detection function. Also good.

[Specific example 2 of device 1 with position detection function]
With reference to FIG. 17, an example will be described in which a screen is used as the viewing surface constituting member 40 of the device 1 with a position detection function, and the device 1 with a position detection function is configured as another screen device with a position detection function. FIG. 17 is an explanatory diagram of another screen device with a position detection function (apparatus 1 with a position detection function) to which the present invention is applied, and FIGS. 17A and 17B are oblique views of the screen device with a position detection function. It is explanatory drawing which shows a mode seen from the top, and explanatory drawing which shows a mode seen from the horizontal direction typically. In the screen device with a position detection function of this embodiment, the configuration of the optical position detection device 10 is the same as the configuration described with reference to FIGS. A description thereof will be omitted.

  A screen device 8 with a position detection function shown in FIGS. 17A and 17B is a screen 80 on which an image is projected from an image projection device 250 (image generation device) called a liquid crystal projector or a digital micromirror device. The visual surface constituting member 40) and the optical position detection device 10 described with reference to FIGS. 11 to 15, and the image projection device 250 is a projection lens provided on the front surface 241 of the housing 240. The image display light Pi is enlarged and projected from the system 210 toward the screen device 8. Therefore, in the screen device 8 with a position detection function, the screen surface 8a onto which an image is projected on the screen 80 constitutes a viewing surface 41 on which information is visually recognized.

  In the screen device 8 with a position detection function, the optical position detection device 10 includes a plurality of detection light sources 12 and a first light receiving unit 31 that emit detection light L2 on the front side of the screen 80 (the screen surface 8a side). It has. In the screen device 8 with the position detection function configured as described above, the detection target space 10R overlaps with a region (image display region 20R) on which an image is projected by the image projection device 250. For this reason, in the screen device 8 with a position detection function of the present embodiment, for example, if the target object Ob such as a fingertip is brought close to a part of the image projected on the screen 80, the position of the target object Ob is switched. It can be used as input information such as instructions.

  In the present embodiment, the screen device for a projection display device on which an image is projected from the image projection device 250 has been described as the screen device 8 with a position detection function. However, the optical position detection device 10 is applied to a screen for an electronic blackboard. May be provided to constitute a screen device with a position detection function for an electronic blackboard.

[Specific example 3 of device 1 with position detection function]
With reference to FIG. 18, an example will be described in which a screen is used as the viewing surface constituting member 40 of the device 1 with a position detection function, and a projection display device with a position detection function is configured by the screen and the image projection device. FIG. 18 is an explanatory diagram of a projection display device with a position detection function (apparatus 1 with a position detection function) to which the present invention is applied, and FIGS. 18A and 18B are projection display devices with a position detection function. It is explanatory drawing which shows a mode that was seen from diagonally upward, and explanatory drawing which shows a mode that was seen from the horizontal direction. In the projection display device with a position detection function of this embodiment, the configuration of the optical position detection device 10 is the same as the configuration described with reference to FIGS. 1 to 6 and FIGS. The same reference numerals are assigned to the parts to be described, and the description thereof is omitted.

  18A and 18B, the projection display device 200 with a position detection function includes an image projection device 250 (image generation device) called a liquid crystal projector or a digital micromirror device, and FIGS. And the optical position detection device 10 described with reference to FIGS. 11 to 15. The image projection device 250 enlarges and projects the image display light Pi from the projection lens system 210 provided on the front surface portion 241 of the housing 240 toward the screen device 8. In the projection display device 200, the screen surface 8a 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 device 200 with a position detection function, the optical position detection device 10 is mounted on the image projection device 250 arranged on the screen surface 8a (viewing surface 41) side of the screen 80. For this reason, the optical position detection device 10 emits the detection light L2 from the image projection device 250 along the viewing surface 41 of the screen 80 (viewing surface constituent member 40). Further, the optical position detection device 10 detects the detection light L <b> 3 reflected by the target object Ob in the image projection device 250.

  In the projection display device 200 with the position detection function configured as described above, the detection target space 10 </ b> R is a rectangular region when viewed from the normal direction with respect to the screen 80, and an image is projected on the screen 80 by the image projection device 250. It overlaps with the area (image display area 20R). For this reason, in the projection display device 200 with a position detection function of the present embodiment, for example, if the target object Ob such as a fingertip is brought close to a part of the image projected on the screen 80, the position of the target object Ob is imaged. It can be used as input information such as a switching instruction.

  1 ・ ・ Device with position detection function, 8 ・ ・ Screen device (device with position detection function), 10 ・ ・ Optical position detection device, 10R ・ ・ Detection target space (detection light emission space), 12, 12A-12D ..Light source for detection 12R..Light source for reference, 12S..First light source for compensation, 12T..Second light source for compensation, 31..First light receiving unit, 32..Second light receiving unit, 40..Visual recognition Surface constituent member, 50... Position detection unit, 51... Light source drive unit, 60... Control unit, 70... Control IC, 81. ..Compensation light source control unit, 88..Lighting pattern control unit, 200..Projection type display device with position detection function (equipment with position detection function).

An optical position detection device according to an aspect of the present invention is an optical position detection device that detects the position of a target object, and includes a detection light source that emits first detection light, and the first detection light is the target object. A first light receiving unit that receives the second detection light reflected by the light, a compensation light source that emits compensation light, a second light receiving unit that receives the compensation light, and a first detection in the first light receiving unit. A position detection unit that detects a position of the target object based on a difference between a result and a second detection result in the second light receiving unit, and a first drive current supplied to the detection light source, The ratio of the second drive current supplied to the compensation light source can be controlled.
The optical position detection device according to the present invention is an optical position detection device that optically detects the position of a target object, and includes a plurality of detection light sources that emit detection light, and the plurality of detection light sources. A light source driving unit that drives the detection light, a first light receiving unit that receives the detection light reflected by the target object located in the emission space of the detection light, and a compensation light source unit that emits compensation light that is not incident on the emission space And a second light receiving unit that receives the compensation light without receiving the detection light, and the target object based on a difference between a light reception intensity at the first light reception unit and a light reception intensity at the second light reception unit. And a position detecting unit for detecting the position of.

Claims (9)

An optical position detection device for optically detecting the position of a target object,
A plurality of light sources for detection that emit detection light;
A light source driving unit for driving the plurality of light sources for detection;
A first light receiving unit that receives the detection light reflected by the target object located in an emission space of the detection light;
A compensation light source unit that emits compensation light that does not enter the exit space;
A second light receiving unit that receives the compensation light without receiving the detection light;
A position detection unit that detects a position of the target object based on a difference between a light reception intensity at the first light reception unit and a light reception intensity at the second light reception unit;
An optical position detection device characterized by comprising:   2. The light receiving intensity of the compensation light at the second light receiving unit is set to the light receiving intensity at the first light receiving unit of the detection light reflected by an object other than the target object. An optical position detection apparatus according to 1. The light source driving unit causes a first operation to emit the detection light from some of the plurality of detection light sources, and a second operation to emit the detection light from some other detection light sources. Perform the action and
The position detection unit is configured to detect a difference between a light reception intensity at the first light receiving unit and the light reception intensity at the second light receiving unit during the first operation, and a light reception at the first light receiving unit during the second operation. The optical position detection device according to claim 1, wherein the position of the target object is detected based on a difference between an intensity and a light reception intensity at the second light receiving unit. The position detection unit is configured to detect a difference between a light reception intensity at the first light receiving unit and the light reception intensity at the second light receiving unit during the first operation, and a light reception at the first light receiving unit during the second operation. The light source driving unit is controlled so that the difference between the intensity and the received light intensity at the second light receiving unit becomes equal, the driving condition for the detection light source during the first operation, and the detection during the second operation Detecting the position of the target object based on the driving condition for the light source for
The emission intensity of the compensation light emitted from the compensation light source unit changes in conjunction with the emission intensity of the detection light emitted from the detection light source during the first operation during the first operation, and The optical position detection device according to claim 3, wherein during the second operation, the optical position detection device changes in conjunction with an emission intensity of the detection light emitted from the light source for detection in the second operation.   The light source drive unit supplies power to the detection light source and the compensation light source unit that emits the detection light during the first operation, and the detection during the second operation during the second operation. 5. The optical position detection device according to claim 3, wherein power is supplied to the detection light source that emits light and the compensation light source unit.   The ratio of the drive current supplied to the detection light source that emits the detection light during the first operation and the drive current supplied to the compensation light source unit, and the detection light that is emitted during the second operation 6. A compensation drive current setting unit that defines a ratio between a drive current supplied to a detection light source and a drive current supplied to the compensation light source unit, respectively. The optical position detection device according to any one of the above.   The compensation light source section emits first compensation light as the compensation light during the first operation, and second compensation light emits second compensation light as the compensation light during the second operation. An optical position detection device according to any one of claims 3 to 6, comprising a light source. The first light receiving unit is a first photoelectric conversion element,
The said 2nd light-receiving part is a 2nd photoelectric conversion element electrically connected in parallel with reverse polarity with respect to this 1st photoelectric conversion element, The Claim 1 thru | or 7 characterized by the above-mentioned. The optical position detection device described.   A device with a position detection function, comprising: the optical position detection device according to any one of claims 1 to 8; and a viewing surface constituent member having a viewing surface.