JP2012221079A - Optical type detection device, display system and information processing system - Google Patents

Abstract

An optical detection device, a display system, an information processing system, and the like that can accurately detect an object by correcting a light reception signal.
An optical detection device includes an irradiation unit that emits irradiation light, and a light receiving unit that receives reflected light from the object OB that is present in the detection area RDET. RU, the correction part 130 which corrects the received light signal from the light receiving part RU, and the detection part 110 which detects the position information of the object OB based on the corrected received light signal from the correction part 130. The correction unit 130 performs correction processing for reducing the dark current component and the default light component included in the light reception signal before correction based on the light reception signal in a state where the object OB does not exist in the detection area RDET.
[Selection] Figure 1

Description

  The present invention relates to an optical detection device, a display system, an information processing system, and the like.

  In recent years, electronic devices such as mobile phones, personal computers, car navigation devices, ticket vending machines, and bank terminals have used display devices with a position detection function in which a touch panel is arranged on the front surface of a display unit. According to this display device, the user can input information by pointing an icon or the like of the display image while referring to the image displayed on the display unit. As a position detection method in such a display device, for example, in Patent Document 1, a light guide is provided along a display area, and irradiation light is irradiated from a plurality of light sources through the light guide. A system is disclosed in which reflected light caused by being reflected by an object is received by a light receiving unit, and the position of the object is detected based on the light reception result.

  However, in such an optical detection device, the light received by the light receiving unit includes default light generated by the irradiation light being reflected from an object other than the object. Since the default light component is included in the light reception result, there is a problem that it is difficult to accurately detect the position information of the object.

JP 2009-295318 A

  According to some aspects of the present invention, it is possible to provide an optical detection device, a display system, an information processing system, and the like that can accurately detect an object by correcting a light reception signal.

  One embodiment of the present invention includes an irradiation unit that emits irradiation light, a light receiving unit that receives reflected light caused by at least the irradiation light being reflected by an object present in a detection area, and a light reception signal from the light receiving unit. And a detection unit that detects position information of the object based on a light reception signal after correction from the correction unit, and the correction unit includes the object in the detection area. The present invention relates to an optical detection apparatus that performs a correction process for reducing dark current components and default light components included in a light reception signal before correction based on a light reception signal in a state in which no light is present.

  According to one aspect of the present invention, the optical detection device can detect position information of an object based on a corrected light reception signal in which a dark current component and a default light component are reduced. As a result, it is possible to detect the position information of the object with high accuracy.

  In the aspect of the invention, the light receiving unit includes a first light receiving element that detects the object and a second light receiving element that detects a dark current, and the correction unit is configured as the light reception signal. , Receiving a first light receiving signal from the first light receiving element and a second light receiving signal from the second light receiving element, and based on the first light receiving signal and the second light receiving signal. The correction process may be performed.

  In this way, the correction unit can detect the dark current component signal from the second light reception signal, and thus can reduce the dark current component included in the first light reception signal.

  In the aspect of the invention, the correction unit may determine the default light component obtained from the difference between the first light reception signal and the second light reception signal and the second light reception signal. The correction process may be performed based on the dark current component.

  According to this configuration, the correction unit obtains the default light component and the dark current component from the first light reception signal and the second light reception signal in a state where there is no object in the detection area, Correction processing can be performed on the first light reception signal in the state where the object is present.

  In the aspect of the invention, the correction unit generates a first difference signal between a first signal corresponding to the first light reception signal and a second signal corresponding to the second light reception signal. A differential signal generating circuit; a holding circuit for holding the differential signal; the first signal corresponding to the first light receiving signal; the holding signal held by the holding circuit; and the second light receiving signal. You may have the 2nd difference signal generation circuit which generates a difference signal with the 2nd signal.

  In this way, the correction unit can subtract the hold signal and the second signal from the first signal, so that the default light component and the dark current component can be reduced.

  In the aspect of the invention, the correction unit amplifies the first light reception signal, outputs the amplified signal as the first signal, and the second light reception signal. A second amplifier circuit that amplifies and outputs the amplified signal as the second signal.

  According to this configuration, the correction unit can perform correction processing based on the first and second signals obtained by amplifying the first and second light reception signals, and thus can perform accurate correction processing. .

  In the aspect of the invention, the second difference signal generation circuit may output the corrected light reception signal to the detection unit during an object detection period in which the object existing in the detection area is detected. It may be output.

  In this way, the detection unit can detect the position information of the object based on the corrected light reception signal, so that highly accurate position information detection and the like can be performed.

  In the aspect of the invention, the irradiation unit emits the first irradiation light having the first irradiation light intensity distribution in the first period, and the first irradiation light intensity in the second period. A first holding circuit that emits second irradiation light having a second irradiation light intensity distribution different from the distribution, and the correction unit holds the holding signal in the first period as the holding circuit; And a second holding circuit for holding the holding signal in the second period.

  In this way, the irradiation unit can alternately form two different irradiation light intensity distributions, so that it is possible to detect an object with higher accuracy while suppressing the influence of ambient light such as ambient light. become. In addition, the correction unit can distinguish and detect the default light component in the first period and the default light component in the second period and hold them separately, so that the received light signal can be corrected more accurately. it can.

  In the aspect of the invention, the irradiation unit emits the first irradiation light having the first irradiation light intensity distribution in the first period, and the first irradiation light intensity in the second period. A second irradiation light having a second irradiation light intensity distribution different from the distribution may be emitted.

  In this way, the irradiation unit can alternately form two different irradiation light intensity distributions, so that it is possible to detect an object with higher accuracy while suppressing the influence of ambient light such as ambient light. become.

  In one aspect of the present invention, the irradiation unit includes a light source unit that emits light source light, a curved light guide that guides the light source light from the light source unit along a curved light guide path, and An irradiation direction setting unit that receives the light source light emitted from the outer peripheral side of the light guide and sets the irradiation direction of the irradiation light in a direction from the inner peripheral side to the outer peripheral side of the curved light guide. But you can.

  If it does in this way, irradiation light can be radiate | emitted in the direction which goes to the outer peripheral side of a curved light guide based on the light source light from a light source part.

  Another aspect of the present invention relates to a display system including any one of the optical detection devices described above and a display device that displays an image.

  Another aspect of the present invention is based on any one of the optical detection devices described above, an information processing device that performs processing based on detection information from the optical detection device, and image data from the information processing device. The present invention relates to an information processing system including a display device that displays an image.

1A and 1B are basic configuration examples of an optical detection device. The 1st structural example of a correction | amendment part. The 2nd structural example of a correction | amendment part. 4A and 4B show examples of signal waveforms of the first configuration example of the correction unit. FIGS. 5A and 5B are examples of signal waveforms of the second configuration example of the correction unit. The 1st structural example of an irradiation part. 7A and 7B show a second configuration example of the irradiation unit. FIG. 8A to FIG. 8C are diagrams illustrating irradiation light emitted by the second configuration example of the irradiation unit. 9A and 9B are diagrams illustrating a method for detecting position information by an optical detection device. 10A and 10B are configuration examples of a display system and an information processing system.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

1. Optical Detection Device FIGS. 1A and 1B show a basic configuration example of the optical detection device of this embodiment. The optical detection device 100 of the present embodiment includes an irradiation unit EU, a light receiving unit RU, a detection unit 110, a control unit 120, and a correction unit 130. The optical detection device 100 according to the present embodiment is not limited to the configuration shown in FIGS. 1A and 1B, and some of the components may be omitted or replaced with other components. Various modifications such as adding the above-described components are possible.

  As shown in FIG. 1A, the optical detection device 100 according to the present embodiment has a detection area RDET set on the front side (Z-axis direction side) of the screen 20 (display unit), such as a user's finger or a touch pen. The object OB is optically detected.

  Here, the XY plane is a plane along a target surface (display surface) defined by the display unit 20, for example. The target surface is a surface to be set for the detection area RDET, and is, for example, a display surface of a display of an information processing device, a projection surface of a projection display device (projector), or a display surface of a digital signage.

  The detection area RDET is an area (region) in which the object OB is detected. Specifically, for example, the light receiving unit RU receives reflected light due to reflection of irradiation light on the object OB. This is an area where the object OB can be detected. More specifically, it is an area where the light receiving unit RU can receive the reflected light to detect the object OB, and the detection accuracy can be ensured within an acceptable range.

  The irradiation unit EU emits irradiation light LT for detecting the object OB. Specifically, the irradiation unit EU emits the first irradiation light LT1 in the first period, and emits the second irradiation light LT2 in the second period. The first irradiation light LT1 and the second irradiation light LT2 have different intensity distributions of the irradiation light. The first period and the second period are provided alternately.

  The irradiation unit EU includes, for example, a light guide and first and second light source units. The first and second light source units have light emitting elements such as LEDs (light emitting diodes) and emit light source light such as infrared light (near infrared light close to the visible light region). And irradiation light LT is radiate | emitted based on this light source light. The detailed configuration of the irradiation unit EU and the irradiation light intensity distribution will be described later.

  The shape of the irradiation unit EU is not limited to a semicircular shape having a central angle of 180 degrees, and may be a sector shape having a central angle smaller than 180 degrees. Further, the semicircular or fan-shaped curved portion (arc portion) may not be an arc (a part of a perfect circle). For example, it may be a part of an ellipse or the like.

  The light receiving unit RU receives the reflected light LR caused by the irradiation light LT emitted from the irradiation unit EU being reflected by the object OB present in the detection area RDET. In addition to the reflected light LR, the light receiving unit RU receives light reflected by an object other than the object OB, that is, default light. In this default light, the irradiation light LT emitted from the irradiation unit EU is reflected by an object other than the object OB (for example, a support member that supports the screen 20 or the optical detection device 100) and enters the light receiving unit RU. Light. Therefore, even if the object OB exists in the detection area RDET or does not exist, the default light does not change. The light receiving unit RU can be realized by a light receiving element such as a photodiode or a phototransistor.

  The light receiving unit RU includes a first light receiving element that detects the object OB and a second light receiving element that detects dark current. As described above, the first light receiving element is for receiving the reflected light LR and the default light from the object OB, and is stored in a housing having a slit or the like through which light can enter, for example. The second light receiving element is for detecting a dark current, and is stored, for example, in a sealed housing so that light does not enter. This dark current is a current generated from the light receiving element even in an environment where light is not incident, and is generated regardless of whether light is incident.

  The light receiving unit RU may be arranged at the center of the semicircular shape of the irradiation unit EU.

  The correction unit 130 receives the light reception signal from the light reception unit RU and performs correction processing of the light reception signal. Specifically, the correction unit 130 receives, as light reception signals, a first light reception signal from the first light reception element and a second light reception signal from the second light reception element, and the first light reception signal Correction processing is performed based on the second received light signal.

  That is, the correction unit 130 performs correction processing for reducing the dark current component and the default light component included in the light reception signal before correction based on the light reception signal in a state where the object OB does not exist in the detection area RDET. Then, the corrected received light signal is output to the detection unit 110. The detailed configuration and operation of the correction unit 130 will be described later.

  The detection unit 110 detects the position information of the object OB based on the corrected light reception signal from the correction unit 130. The function of the detection unit 110 can be realized by an integrated circuit device having an analog circuit or the like, or software (program) operating on a microcomputer. A method for detecting position information will be described later.

  Here, the position information (position specifying information) of the object may be information that specifies the position of the object, and is not limited to the position coordinates of the object. For example, an angle for specifying the position of the object Etc.

  The control unit 120 performs various control processes of the optical detection device 100. Specifically, light emission control of a light emitting element included in the irradiation unit EU is performed. The control unit 120 is electrically connected to the irradiation unit EU, the detection unit 110, and the correction unit 130. The function of the control unit 120 can be realized by software operating on an integrated circuit device or a microcomputer. For example, when the irradiation unit EU includes first and second light source units, the control unit 120 performs control to cause the first and second light source units to emit light alternately.

  FIG. 2 shows a first configuration example of the correction unit 130 of the present embodiment. The first configuration example of the correction unit 130 includes first and second amplifier circuits AMP1 and AMP2, first and second differential signal generation circuits DF1 and DF2, and a holding circuit HL. The correction unit 130 of the present embodiment is not limited to the configuration in FIG. 2, and various modifications such as omitting some of the components, replacing them with other components, and adding other components. Implementation is possible.

  The correction unit 130 receives, as light reception signals, the first light reception signal VR1 from the first light reception element PD1 and the second light reception signal VR2 from the second light reception element PD2, and receives the first light reception signal VR1. Correction processing is performed based on the second light reception signal VR2. Specifically, the correction unit 130 converts the default light component obtained from the difference between the first light reception signal VR1 and the second light reception signal VR2 and the dark current component obtained from the second light reception signal VR2. Based on this, correction processing is performed.

  The first amplifier circuit AMP1 amplifies the first light reception signal VR1, and outputs the amplified signal as a first signal VQ5 corresponding to the first light reception signal. The second amplifier circuit AMP2 amplifies the second light reception signal VR2, and outputs the amplified signal as a second signal VQ6 corresponding to the second light reception signal.

  The first amplifier circuit AMP1 includes an operational amplifier OP5, capacitors C1a and C1b, and resistance elements R5a and R5b. Capacitors C1a and C1b block the DC component of the light reception signal from light receiving element PD1 and allow the AC component to pass through. The resistance elements R5a and R5b are for setting the amplification factor of the first amplifier circuit AMP1. The second amplifier circuit AMP2 can also have the same configuration as the AMP1.

  The first difference signal generation circuit DF1 is a difference signal VQ1 (= VQ5-VQ6) between the first signal VQ5 corresponding to the first light reception signal VR1 and the second signal VQ6 corresponding to the second light reception signal VR2. Is generated. The first differential signal generation circuit DF1 includes an operational amplifier OP1 and resistance elements R1a to R1d. The resistance values of the resistance elements R1a to R1d are set so that desired operating characteristics can be obtained in the voltage range of the two input signals VQ5 and VQ6.

  The holding circuit HL holds (holds) the voltage level of the differential signal VQ1 from DF1 by the capacitor C4. Then, the operational amplifier OP4 outputs a signal having the same voltage level as the held voltage as the held signal VHL. The operational amplifier OP4 operates as an amplifier (voltage follower) having a gain of 1. The switch circuit SW is set to an on state during the default light detection period, and is set to an off state during the object detection period. That is, the holding circuit HL receives the differential signal VQ1 from DF1 in the default light detection period, and holds the voltage level of VQ1 in the capacitor C4. In the object detection period, the signal VHL having the same voltage level as that of the held VQ1 is output. The on / off control of the switch circuit SW is performed by a control signal SCN from the control unit 120.

  The default light detection period is a period for detecting default light, and no object OB exists in the detection area RDET during this period. The object detection period is a period for detecting the object OB present in the detection area RDET. The default light detection period is provided before the object detection period. It can also be provided between one object detection period and the next object period. For example, when the state in which the object is not detected continues for a certain period of time during the object detection period, the control unit 120 controls to shift to the default light detection period, and returns to the object detection period again after the end of the default light detection period. can do.

  The second difference signal generation circuit DF2 generates a difference signal VQ2 (= VQ5-VHL) between the first signal VQ5 corresponding to the first light reception signal VR1 and the holding signal VHL held by the holding circuit HL. Then, a difference signal VQ3 (= VQ2−VQ6) between the signal VQ2 and the second signal VQ6 corresponding to the second light reception signal VR2 is generated and output to the detection unit 110. The second differential signal generation circuit DF2 includes an operational amplifier OP2, resistance elements R2a to R2d, an operational amplifier OP3, and resistance elements R3a to R3d. The resistance values of the resistance elements R2a to R2d are set so that desired operating characteristics of OP2 are obtained in the voltage range of the two input signals VQ5 and VHL. The resistance values of the resistance elements R3a to R3d are set so that desired operational characteristics of OP3 can be obtained in the voltage range of the two input signals VQ2 and VQ6.

  According to the correction unit 130 of the present embodiment illustrated in FIG. 2, the received light signal correction process can be performed as follows.

  In the default light detection period, the light reception signal VR1 by the default light received by the first light receiving element PD1 is amplified by the first amplifier circuit AMP1 to obtain the first signal VQ5. Further, the signal VR2 due to the dark current from the second light receiving element PD2 is amplified to obtain a second signal VQ6. Then, the first difference signal generation circuit DF1 generates the difference signal VQ1 = VQ5-VQ6, and the holding circuit HL holds the same voltage level as VQ1 as the holding signal VHL. In this way, since the dark current component VR2 (signal VQ6 obtained by amplifying VR2) can be subtracted from the light reception signal VR1 (signal VQ5 obtained by amplifying VR1), a signal corresponding to the signal by default light (default light component) is obtained. It can be detected with high accuracy.

  In the target detection period, the first amplification circuit AMP1 amplifies the received light signal VR1 including the reflected light LR from the target OB received by the first light receiving element PD1 to obtain the first signal VQ5. Further, the signal VR2 due to the dark current from the second light receiving element PD2 is amplified to obtain a second signal VQ6. Then, the second difference signal generation circuit DF2 obtains the difference signal VQ2 = VQ5-VHL, and further obtains the difference signal VQ3 = VQ2-VQ6. By doing so, the signal VHL corresponding to the default light component and the dark current component VR2 (second signal VQ6 obtained by amplifying VR2) can be subtracted from the light reception signal VR1 (first signal VQ5 obtained by amplifying VR1). The light reception signal VR1 can be corrected with high accuracy.

  In the second difference signal generation circuit DF2 shown in FIG. 2, the difference signal VQ2 between the first signal VQ5 and the hold signal VHL is first generated, and then the difference signal between VQ2 and the second signal VQ6 is generated. Although generated, this order may be reversed. That is, the difference signal VQ2 'between the first signal VQ5 and the second signal VQ6 may be generated first, and then the difference signal between VQ2' and the holding signal VHL may be generated.

  FIG. 3 shows a second configuration example of the correction unit 130 of the present embodiment. The second configuration example includes first and second holding circuits HL1 and HL2 as the holding circuit HL. Other components are the same as those in the first configuration example shown in FIG.

  The first holding circuit HL1 includes an operational amplifier OP41, a capacitor C41, and switch circuits SW1a and SW1b. The operations of the operational amplifier OP41 and the capacitor C41 are the same as those of the holding circuit HL in FIG. The switch circuit SW1a is set to an on state during the first period of the default light detection period, and is set to an off state during other periods. The switch circuit SW1b is set to an on state during the first period of the object detection period, and is set to an off state during other periods. Therefore, the first holding circuit HL1 holds the holding signal VHL1 in the first period.

  The second holding circuit HL2 includes an operational amplifier OP42, a capacitor C42, and switch circuits SW2a and SW2b. The operations of the operational amplifier OP42 and the capacitor C42 are the same as those of the holding circuit HL in FIG. The switch circuit SW2a is set to an on state during the second period of the default light detection period, and is set to an off state during other periods. In addition, the switch circuit SW2b is set to an on state during the second period of the object detection period, and is set to an off state during other periods. Accordingly, the second holding circuit HL2 holds the holding signal VHL2 in the second period.

  In this way, the first holding circuit HL1 can hold the voltage level of the signal corresponding to the default light component by the first irradiation light LT1 emitted in the first period of the default light detection period. In addition, the second holding circuit HL2 can hold the voltage level of a signal corresponding to the default light component by the second irradiation light LT1 emitted in the second period of the default light detection period. By doing so, the correction unit 130 performs correction processing using the signal VHL1 held in the first holding circuit HL1 in the first period of the object detection period, and performs the second period of the object detection period. Then, correction processing can be performed using the signal VHL2 held in the second holding circuit HL2.

  As will be described later, the first irradiation light LT1 emitted in the first period and the second irradiation light LT2 emitted in the second period have different irradiation light intensity distributions. For this reason, the signal based on the default light received by the light receiving unit RU during the first period may be different from the signal based on the default light received during the second period. Even in such a case, according to the second configuration example of the correction unit 130 illustrated in FIG. 3, the default light component in the first period and the default light component in the second period are detected and retained separately. Therefore, the received light signal can be corrected with higher accuracy.

  4A and 4B are examples of signal waveforms of the first configuration example (FIG. 2) of the correction unit 130. FIG. 4A and 4B show light emission currents ILS1 and ILS2 that emit light from the first and second light source units LSU1 and LSU2 and signals VQ1, VQ2, VQ3, VQ5, VQ6, and VHL. FIG. 4A shows a signal waveform in the default light detection period, and FIG. 4B shows a signal waveform in the object detection period.

  As shown in FIGS. 4A and 4B, the first light source LSU1 emits light during the first period T1, and thus the first irradiation light LT1 is emitted, and the second light emission period LT2 during the second period T2. The second irradiation light LT2 is emitted when the second light source unit LSU2 emits light. The first and second periods T1 and T2 are alternately provided.

  In the default light detection period, since the object OB does not exist in the detection area RDET, the first light receiving signal VR1 from the first light receiving element PD1 includes a default light component and a dark current component. As shown in FIG. 4A, the first signal VQ5 obtained by amplifying the first light reception signal VR1 is the sum (VD + V0) of the signal VD corresponding to the default light component and the signal V0 corresponding to the dark current component. Become. Here, the signal VD corresponding to the default light component is equal in the first period T1 and the second period T2, or the difference between the two is small enough to be ignored.

  Further, the second light receiving signal VR2 from the second light receiving element PD2 includes only the dark current component. Therefore, the second signal VQ6 obtained by amplifying the second light receiving signal VR2 is a signal V0 corresponding to the dark current component. become. The difference signal VQ1 between VQ5 and VQ6 is VQ1 = VQ5-VQ6 = VD, and the signal VD corresponding to the default light component can be extracted. Since the switch circuit SW of the holding circuit HL is set to the ON state in the default light detection period, the voltage level of the signal VD is held by the holding circuit HL. After the end of the default light detection period, the switch circuit SW is set to the OFF state, and the holding signal VHL continues to hold the voltage level of the signal VD corresponding to the default light component.

  In the default light detection period shown in FIG. 4A, the first and second periods T1 and T2 are both provided five times, but the number of times is not limited to this. Any number of times may be used as long as the capacitor C4 of the holding circuit HL is fully charged and the voltage level of the signal VD can be reliably held.

  Note that the switch circuit SW of the holding circuit HL may be set to the on state in the first period T1 of the default light detection period, or may be set to the on state in the second period T2 of the default light detection period. Good. Alternatively, the ON state may be set in the first period T1 and the second period T2 of the default light detection period.

  On the other hand, since the object OB exists in the detection area RDET during the object detection period, the first received light signal VR1 from the first light receiving element PD1 is reflected light LR, default light component, and dark current from the object OB. And ingredients. As shown in FIG. 4B, the first signal VQ5 obtained by amplifying the first light reception signal VR1 is a signal VX1 (or VX2) corresponding to the reflected light LR, a signal VD corresponding to the default light component, and a dark current. It becomes the sum (VX1 + VD + V0 or VX2 + VD + V0) with the signal V0 corresponding to the component. Here, VX1 is a signal corresponding to the reflected light LR in the first period T1, and VX2 is a signal corresponding to the reflected light LR in the second period T2.

  Further, the second light receiving signal VR2 from the second light receiving element PD2 includes only the dark current component. Therefore, the second signal VQ6 obtained by amplifying the second light receiving signal VR2 is a signal V0 corresponding to the dark current component. become. Since the hold signal VHL holds the voltage level of the signal VD corresponding to the default light component even in the object detection period, the difference signal VQ2 between VQ5 and VHL is VQ2 = VQ5− in the first period T1. VHL = VX1 + V0, and VQ2 = VX2 + V0 in the second period. The difference signal VQ3 between VQ2 and VQ6 is VQ3 = VQ2-VQ6 = VX1 in the first period T1, and VQ3 = VX2 in the second period. In this manner, the default light component and dark current component included in the first light reception signal VR1 can be removed or reduced.

  In FIG. 4B, the difference signal VQ2 between VQ5 and VQ6 is generated first, and then the difference signal VQ3 between VQ2 and VHL is generated. A difference signal VQ2 ′ between VQ2 and VHL may be generated, and then a difference signal VQ3 between VQ2 ′ and VQ6 may be generated.

  When correction processing by the correction unit 130 of the present embodiment is not performed, for example, when the first signal VQ5 obtained by amplifying the first light reception signal VR1 is output to the detection unit 110 as it is, a signal that can be input to the detection unit 110 It is necessary to set a large level range (dynamic range). Therefore, the ratio of the signal level of the difference signal between VX1 and VX2, which is a signal component effective for object detection, to the dynamic range is small, and as a result, the accuracy of position information detection in the detection unit 110 may be reduced. .

  On the other hand, when the correction process by the correction unit 130 of the present embodiment is performed, the signal VQ3 from which the default light component and the dark current component are removed can be output to the detection unit 110, so that the dynamic range is set to be small. Can do. By doing so, the ratio of the signal level of the difference signal between VX1 and VX2 to the dynamic range can be increased, and as a result, the accuracy of position information detection in the detection unit 110 can be further increased. .

  5A and 5B are examples of signal waveforms of the second configuration example (FIG. 3) of the correction unit 130. FIG. FIGS. 5A and 5B show light emission currents ILS1 and ILS2 that emit light from the first and second light source units LSU1 and LSU2 and signals VQ1, VQ2, VQ3, VQ5, VQ6, VHL1, and VHL2. . FIG. 5A shows a signal waveform during the default light detection period, and FIG. 5B shows a signal waveform during the object detection period.

  As described above, in the second configuration example (FIG. 3), the first holding circuit HL1 can hold the signal VD1 corresponding to the default light component in the first period T1. Further, the second holding circuit HL2 can hold the signal VD2 corresponding to the default light component in the second period T2.

  In the default light detection period, the first signal VQ5 obtained by amplifying the first light reception signal VR1 is the sum of VD1 and V0 (VD1 + V0) in the first period, as shown in FIG. In the period 2, the sum of VD2 and V0 (VD2 + V0) is obtained. Further, the second light receiving signal VR2 from the second light receiving element PD2 includes only the dark current component. Therefore, the second signal VQ6 obtained by amplifying the second light receiving signal VR2 is a signal V0 corresponding to the dark current component. become. The difference signal VQ1 between VQ5 and VQ6 is VQ1 = VQ5−VQ6 = VD1 in the first period T1, and VQ1 = VD2 in the second period T2.

  Since the switch circuit SW1a of the first holding circuit HL1 is set to the ON state in the first period T1 of the default light detection period, the voltage level of the signal VD1 is held by the first holding circuit HL1. Further, since the switch circuit SW2a of the second holding circuit HL2 is set to the ON state in the second period T2 of the default light detection period, the voltage level of the signal VD2 is held by the second holding circuit HL2.

  In the object detection period, the signal VQ5 obtained by amplifying the first light reception signal VR1 is a signal VX1 (or VX2) corresponding to the reflected light LR and a signal VD1 corresponding to the default light component, as shown in FIG. (Or VD2) and a signal V0 corresponding to the dark current component (VX1 + VD1 + V0 or VX2 + VD2 + V0).

  Since the switch circuit SW1b of the first holding circuit HL1 is set to the ON state in the first period T1 of the object detection period, the holding signal VHL1 is output to the difference signal generation circuit DF2 in the first period T1. . In addition, since the switch circuit SW2b of the second holding circuit HL2 is set to the ON state in the second period T2 of the object detection period, the holding signal VHL2 is output to the difference signal generation circuit DF2 in the second period T2. The

  Thus, the difference signal VQ2 output from the difference signal generation circuit DF2 is VQ2 = VQ5−VHL1 = VX1 + V0 in the first period T1, and VQ2 = VX2 + V0 in the second period. The difference signal VQ3 between VQ2 and VQ6 is VQ3 = VQ2-VQ6 = VX1 in the first period T1, and VQ3 = VX2 in the second period. In this manner, the default light component and dark current component included in the first light reception signal VR1 can be removed or reduced.

  As described above, according to the second configuration example of the correction unit 130 of the present embodiment, the default light component in the first period T1 and the default light component in the second period T2 are detected separately and held separately. Therefore, the received light signal can be corrected with higher accuracy.

  As described above, according to the optical detection device 100 of the present embodiment, the correction process by the correction unit 130 can reduce the dark current component and the default light component included in the light reception signal before correction. it can. Further, by performing the correction process by the correction unit 130, it is possible to increase the ratio of the signal level of the signal component effective for object detection to the dynamic range of the detection unit 110. As a result, it is possible to further increase the accuracy of detecting the position information of the object.

2. Irradiation unit FIG. 6 shows a first configuration example of the irradiation unit EU of the present embodiment. The first configuration example of the irradiation unit EU includes first and second light source units LSU1 and LSU2, a light guide LG, and an irradiation direction setting unit LE. Moreover, the reflective sheet RS is included. The irradiation direction setting unit LE includes a prism sheet PS and a louver film LF. Note that the irradiation unit EU of the present embodiment is not limited to the configuration of FIG. 6, and various components such as omitting some of the components, replacing them with other components, and adding other components. Variations are possible.

  The light source units LSU1 and LSU2 emit light source light and have light emitting elements such as LEDs (light emitting diodes). The light source units LSU1 and LSU2 emit, for example, infrared light (near infrared light close to the visible light region). That is, the light source light emitted by the light source units LSU1 and LSU2 has a wavelength band that is not included in the wavelength band light that is efficiently reflected by an object such as a user's finger or a touch pen, or ambient light that becomes disturbance light. It is desirable to be light. Specifically, infrared light with a wavelength near 850 nm, which is light in a wavelength band with high reflectance on the surface of the human body, infrared light near 950 nm, which is light in a wavelength band that is not so much included in environmental light, etc. It is.

  The first light source unit LSU1 is provided on one end side of the light guide LG as indicated by F1 in FIG. The second light source unit LSU2 is provided on the other end side of the light guide LG as indicated by F2. The first light source unit LSU1 emits the light source light to the light incident surface on one end side (F1) of the light guide LG, thereby emitting the first irradiation light LT1, and the first irradiation light intensity distribution. LID1 is formed (set). On the other hand, the second light source unit LSU2 emits the second light source light to the light incident surface on the other end side (F2) of the light guide LG, thereby emitting the second irradiation light LT2, The second irradiation light intensity distribution LID2 having an intensity distribution different from the irradiation light intensity distribution LID1 is formed. Thus, the irradiation unit EU can emit irradiation light having different intensity distributions.

  The light guide LG (light guide member) guides the light source light emitted from the light source units LSU1 and LSU2. For example, the light guide LG guides the light source light from the light source units LSU1 and LSU2 along a curved light guide path, and the shape thereof is a curved shape. Specifically, in FIG. 6, the light guide LG has an arc shape. In FIG. 6, the light guide LG has an arc shape with a center angle of 180 degrees, but may have an arc shape with a center angle smaller than 180 degrees. The light guide LG is formed of, for example, a transparent resin member such as acrylic resin or polycarbonate.

  At least one of the outer peripheral side and the inner peripheral side of the light guide LG is processed to adjust the light output efficiency of the light source light from the light guide LG. As a processing method, for example, various methods such as a silk printing method for printing reflective dots, a molding method for forming irregularities with a stamper or injection, and a groove processing method can be adopted.

  The irradiation direction setting unit LE realized by the prism sheet PS and the louver film LF is provided on the outer peripheral side of the light guide LG and receives light source light emitted from the outer peripheral side (outer peripheral surface) of the light guide LG. And the irradiation light LT1 and LT2 in which the irradiation direction was set to the direction which goes to the outer peripheral side from the inner peripheral side of the light guide LG of curved shape (arc shape) are radiate | emitted. That is, the direction of the light source light emitted from the outer peripheral side of the light guide LG is set (restricted) to an irradiation direction along, for example, the normal direction (radial direction) of the light guide LG. Thereby, irradiation light LT1 and LT2 come to radiate | emit radially in the direction which goes to the outer peripheral side from the inner peripheral side of the light guide LG.

  Such setting of the irradiation direction of the irradiation light LT1, LT2 is realized by the prism sheet PS, the louver film LF, or the like of the irradiation direction setting unit LE. For example, the prism sheet PS sets the direction of the light source light emitted at a low viewing angle from the outer peripheral side of the light guide LG to the normal direction side so that the peak of the light emission characteristic is in the normal direction. The louver film LF blocks (cuts) light in a direction other than the normal direction (low viewing angle light).

  As described above, according to the irradiation unit EU of the present embodiment, the light source LSU1 and LSU2 are provided at both ends of the light guide LG, and these light source units LSU1 and LSU2 are turned on alternately to obtain two irradiation light intensity distributions. Can be formed. That is, the irradiation light intensity distribution LID1 in which the intensity on one end side of the light guide LG is increased and the irradiation light intensity distribution LID2 in which the intensity on the other end side of the light guide LG is increased can be alternately formed.

  7A and 7B show a second configuration example of the irradiation unit EU of the present embodiment. The second configuration example of the irradiation unit EU includes first to nth (n is an integer of 2 or more) light emitting elements LD1 to LDn arranged along the curves CUR1 and CUR2. Note that the irradiation unit EU of the present embodiment is not limited to the configuration shown in FIGS. 7A and 7B, and some of the components are omitted or replaced with other components. Various modifications such as adding elements are possible.

  As shown in FIG. 7A, the first to m-th light emitting elements LD1 to LDm (m is an integer satisfying 1 <m <n) among the n light emitting elements follow the first curve CUR1. Arranged. In addition, m + 1 to nth light emitting elements LDm + 1 to LDn among the n light emitting elements are arranged along a second curve CUR2 that is located away from the first curve CUR1.

  The first light emitting element LD1 is disposed at one end of the first curve CUR1, and the mth light emitting element LDm is disposed at the other end. The m + 1th light emitting element LDm + 1 is disposed at one end of the second curve CUR2, and the nth light emitting element LDn is disposed at the other end.

  The first to nth light emitting elements LD1 to LDn are, for example, LEDs (light emitting diodes) that emit infrared light (near infrared light close to the visible light region), and are arranged along the curves CUR1 and CUR2. Each light is emitted. The curves CUR1 and CUR2 may be circular arcs or curves with varying radii of curvature. Further, the arrangement intervals of the light emitting elements may be equal intervals, or may be intervals that change.

  For the following description, as shown in FIG. 7A, first, second, and third directions D1, D2, and D3 are defined. That is, the direction from the other end to the one end of the curves CUR1 and CUR2 is defined as a second direction D2, and the direction perpendicular to the second direction D2 and directed from the inside to the outside of the curves CUR1 and CUR2 is defined as a first direction D1. A direction perpendicular to the first and second directions D1 and D2 is defined as a third direction D3.

  The first curve CUR1 and the second curve CUR2 do not cross each other and are arranged at positions separated from each other. Specifically, for example, the first curve CUR1 and the second curve CUR2 are arranged separately in the third direction D3. The distance (interval) in the third direction D3 between the first curve CUR1 and the second curve CUR2 may be constant or may vary.

  FIG. 7B is a diagram of a second configuration example of the irradiation unit EU as viewed from the second direction D2. The first to mth light emitting elements LD1 to LDm respectively emit light source light along the first irradiation reference plane SL1. The m + 1 to nth light emitting elements LDm + 1 to LDn emit light source light along the second irradiation reference plane SL2. The first and second irradiation reference surfaces SL1 and SL2 are virtual surfaces for defining the direction in which the irradiation unit EU emits the irradiation light, and the irradiation light is emitted along these irradiation reference surfaces SL1 and SL2. Emitted.

  However, since the light source light from each light emitting element spreads at a certain angle, the irradiation light emitted based on the light source light is not limited to the irradiation reference planes SL1 and SL2, and the irradiation reference plane SL1. , SL3 has a certain spread in the third direction D3 and the opposite direction with reference to SL2.

  In the following description, the first to mth light emitting elements LD1 to LDm are collectively referred to as a first light emitting element group, and the m + 1st to nth light emitting elements LDm + 1 to LDn are collectively referred to as a second light emitting element. It is described as a group.

  FIG. 8A to FIG. 8C are diagrams illustrating irradiation light emitted by the second configuration example of the irradiation unit EU. 8A to 8C include, for example, first to thirteenth light emitting elements LD1 to LD13 as the first light emitting element group, and fourteenth to twenty sixth light emitting elements as the second light emitting element group. A configuration example including LD14 to LD26 will be described.

  FIG. 8A shows the first irradiation light LT1 emitted in the first period. In the first period, the first light-emitting element groups (LD1 to LD13) are arranged such that the first light source light LS1-1 to LS1-1, in which the light amount of each light-emitting element decreases from one end of the first curve CUR1 to the other end. LS1-13 is emitted. For example, LD 1 emits light source light LS 1-1, the next LD 2 emits light source light LS 1-2 with a lower light amount than LD 1, and the next LD 3 emits light source light LS 1-3 with a light amount lower than LD 2. . The last LD 13 emits light source light LS1-13 having a light quantity lower than that of the LD 12. That is, the light source light with the highest light quantity is emitted from one end of the first curve CUR1, the light quantity gradually decreases from one end to the other end, and the light source light with the lowest light quantity is emitted from the other end.

  Thus, in the first period, the first light source lights LS1-1 to LS1-13 are emitted, and based on this, the intensity of the irradiation light decreases from one end to the other end of the first curve CUR1. The first irradiation light LT1 is emitted. As a result, the first irradiation light intensity distribution LID1 is formed in the first period. The first irradiation light LT1 is light obtained by combining the first light source lights LS1-1 to LS1-13 emitted from the light emitting elements.

  FIG. 8B shows the second irradiation light LT2 emitted in the second period. In the second period, in the second light emitting element group (LD14 to LD26), the light amount of each light emitting element increases from one end of the second curve CUR2 toward the other end. LS2-26 is emitted. For example, the LD 14 emits the light source light LS2-14, the next LD15 emits the light source light LS2-15 having a higher light quantity than the LD14, and the next LD16 emits the light source light LS2-16 having a higher light quantity than the LD15. . The last LD 26 emits light source light LS2-26 having a light quantity higher than that of the LD 25. That is, the light source light with the lowest light quantity is emitted from one end of the second curve CUR2, the light quantity gradually increases from one end to the other end, and the light source light with the highest light quantity is emitted from the other end.

  Thus, in the second period, the second light source lights LS2-14 to LS2-26 are emitted, and based on this, the intensity of irradiation light increases from one end to the other end of the second curve CUR2. The second irradiation light LT2 is emitted. As a result, in the second period, a second irradiation light intensity distribution different from the first irradiation light intensity distribution LID1 is formed. The second irradiation light LT2 is light obtained by combining the second light source lights LS2-14 to LS2-26 emitted from the light emitting elements.

  As shown in FIG. 8C, the first and second irradiation lights LT1 and LT2 are irradiated along the first and second irradiation reference planes SL1 and SL2, but as described above, the irradiation light The range irradiated with LT1 and LT2 is not limited to the plane of the first and second irradiation reference planes SL1 and SL2, but is constant in the third direction D3 and the opposite direction with respect to the irradiation reference planes SL1 and SL2. With expanse.

  As described above, according to the irradiation unit EU of the present embodiment, the first irradiation light intensity distribution is formed in the first period, and the second irradiation period is different from the first irradiation light intensity distribution in the second period. Can be formed. As will be described later, in the optical detection device of the present embodiment, the influence of disturbance light such as ambient light is minimized by receiving the reflected light of the object by irradiation light having different intensity distributions. It is possible to detect an object with higher accuracy. That is, it is possible to cancel out the infrared component included in the disturbance light, and it is possible to minimize the adverse effect of the infrared component on the detection of the object.

3. Position Information Detection Method FIGS. 9A and 9B are diagrams illustrating a method for detecting position information by the optical detection device of the present embodiment.

  E1 in FIG. 9A is the relationship between the irradiation direction angle of the first irradiation light LT1 and the intensity (luminous intensity, radiation intensity) of the irradiation light LT1 at that angle in the first irradiation light intensity distribution LID1. FIG. At E1 in FIG. 9A, the intensity is highest when the irradiation direction is the direction DD1 in FIG. 9B (left direction). On the other hand, the intensity is lowest when the direction is DD3 (right direction), and the intensity is intermediate in the direction DD2. Specifically, the intensity of the irradiation light monotonously decreases with respect to the angle change from the direction DD1 to the direction DD3, for example, changes linearly (linearly).

  Further, E2 in FIG. 9A is a diagram showing the relationship between the angle of the irradiation direction of the second irradiation light LT2 and the intensity of the irradiation light LT2 at that angle in the second irradiation light intensity distribution LID2. . At E2 in FIG. 9A, the intensity is highest when the irradiation direction is the direction of DD3 in FIG. 9B. On the other hand, the intensity is the lowest in the direction of DD1, and the intermediate intensity in the direction of DD2. Specifically, the intensity of irradiation light monotonously decreases with respect to the angle change from the direction DD3 to the direction DD1, and changes linearly, for example. In FIG. 9A, the relationship between the angle in the irradiation direction and the intensity is linear, but the present embodiment is not limited to this, and may be a hyperbolic relationship, for example.

  Then, as shown in FIG. 9B, it is assumed that the object OB exists in the direction DDB of the angle θ. Then, when the first irradiation light intensity distribution LID1 is formed in the first period (in the case of E1), as shown in FIG. 9A, the object OB existing in the direction of DDB (angle θ). The intensity at the position is INTa. On the other hand, when the second irradiation light intensity distribution LID2 is formed in the second period (in the case of E2), the intensity at the position of the object OB existing in the direction of DDB is INTb. Therefore, the direction DDB (angle θ) in which the object OB is located can be specified by obtaining the relationship between the intensities INTa and INTb.

  In order to obtain such a relationship between the intensity INTa and INTb, in the present embodiment, the light receiving unit RU receives the reflected light (first reflected light) of the object OB when the irradiation light intensity distribution LID1 is formed. . If the detected light reception amount of the reflected light at this time is Ga, this Ga corresponds to the intensity INTa. The light receiving unit RU receives the reflected light (second reflected light) of the object OB when the irradiation light intensity distribution LID2 is formed. When the detected light reception amount of the reflected light at this time is Gb, this Gb corresponds to the intensity INTb. Therefore, if the relationship between the detected light reception amounts Ga and Gb is obtained, the relationship between the intensity INTa and INTb can be obtained, and the direction DDB in which the object OB is located can be obtained.

  For example, the control amount (for example, current amount), the conversion coefficient, and the amount of emitted light of the light source unit LSU1 are Ia, k, and Ea, respectively. The control amount (current amount), the conversion coefficient, and the amount of emitted light of the light source unit LSU2 are Ib, k and Eb, respectively. Then, the following expressions (1) and (2) are established.

Ea = k · Ia (1)
Eb = k · Ib (2)
Further, let fa be the attenuation coefficient of the light source light (first light source light) from the light source unit LSU1, and let Ga be the detected received light amount of the reflected light (first reflected light) corresponding to this light source light. Further, the attenuation coefficient of the light source light (second light source light) from the light source unit LSU2 is set to fb, and the detected light reception amount of the reflected light (second reflected light) corresponding to the light source light is set to Gb. Then, the following expressions (3) and (4) are established.

Ga = fa · Ea = fa · k · Ia (3)
Gb = fb · Eb = fb · k · Ib (4)
Therefore, the ratio of the detected light reception amounts Ga and Gb can be expressed as the following equation (5).

Ga / Gb = (fa / fb). (Ia / Ib) (5)
Here, Ga / Gb can be specified from the light reception result in the light receiving unit RU, and Ia / Ib can be specified from the control amount of the irradiation unit EU. The intensities INTa and INTb and the attenuation coefficients fa and fb in FIG. 9A have a unique relationship. For example, when the attenuation coefficients fa and fb are small values and the attenuation is large, it means that the strengths INTa and INTb are small. On the other hand, when the attenuation coefficients fa and fb are large and the attenuation is small, it means that the strengths INTa and INTb are large. Therefore, the direction, position, etc. of the object can be obtained by obtaining the attenuation factor ratio fa / fb from the above equation (5).

  More specifically, one control amount Ia is fixed to Im, and the other control amount Ib is controlled so that the detected light reception amount ratio Ga / Gb becomes 1. For example, the light source units LSU1 and LSU2 are controlled to turn on alternately in reverse phase, the detected light reception amount waveform is analyzed, and the other control is performed so that the detected waveform is not observed (Ga / Gb = 1). The amount Ib is controlled. Then, from the other control amount Ib = Im · (fa / fb) at this time, the ratio fa / fb of the attenuation coefficient is obtained, and the direction, position, etc. of the object are obtained.

  Further, as in the following formulas (6) and (7), control may be performed so that Ga / Gb = 1 and the sum of the control amounts Ia and Ib is constant.

Ga / Gb = 1 (6)
Im = Ia + Ib (7)
Substituting the above equations (6) and (7) into the above equation (5), the following equation (8) is established.

Ga / Gb = 1 = (fa / fb) · (Ia / Ib)
= (Fa / fb) · {(Im−Ib) / Ib} (8)
From the above equation (8), Ib is expressed as the following equation (9).

Ib = {fa / (fa + fb)} · Im (9)
Here, if α = fa / (fa + fb), the above equation (9) is expressed as the following equation (10), and the attenuation coefficient ratio fa / fb is expressed by the following equation (11) using α. It is expressed in

Ib = α · Im (10)
fa / fb = α / (1-α) (11)
Therefore, if Ga / Gb = 1 and control is performed so that the sum of Ia and Ib becomes a constant value Im, α is obtained from Ib and Im at that time by the following equation (10), and the obtained α is increased. By substituting into Equation (11), the ratio fa / fb of the attenuation coefficient can be obtained. This makes it possible to obtain the direction, position, etc. of the object. Further, by controlling so that Ga / Gb = 1 and the sum of Ia and Ib becomes constant, it becomes possible to cancel the influence of disturbance light and the like, and the detection accuracy can be improved.

  In the above description, the first configuration example (FIG. 6) of the irradiation unit EU has been described as an example, but the second configuration example (FIGS. 7A and 7B) is also subject to the same method. The direction (angle θ) in which the object OB is located can be specified. In the second configuration example, the first light emitting element group (LD1 to LDm) corresponds to the first light source unit LSU1, and the second light emitting element group (LDm + 1 to LDn) corresponds to the second light source unit. Corresponds to LSU2.

4). Display System and Information Processing System FIGS. 10A and 10B show a configuration example of the display system and the information processing system of the present embodiment. The configuration example of the display system illustrated in FIG. 10A includes an optical detection device 100 and a display device 10. The configuration example of the information processing system illustrated in FIG. 10A includes an optical detection device 100, a display device 10, and an information processing device 200.

  The information processing apparatus 200 is a personal computer (PC), for example, and performs processing based on detection information from the optical detection apparatus 100. The optical detection device 100 and the information processing device 200 are electrically connected via a USB cable USBC. The display device 10 is, for example, a projection display device (projector) or the like, and displays an image on the display unit (screen) 20 based on image data from the information processing device 200. The user can input necessary information to the information processing apparatus 200 by pointing an icon or the like of the display image while referring to the image displayed on the display unit 20.

  In FIG. 10A, the optical detection device 100 is attached to the display unit 20; however, it can be attached to another location. For example, the optical detection device 100 may be attached to the display device 10, or may be attached to a ceiling or a wall. Further, the display device 10 is not limited to a projection display device (projector), and may be a display device for digital signage, for example.

  In the configuration example of the information processing system illustrated in FIG. 10B, a display 220 incorporated in the information processing apparatus 200 (PC) is used as the display apparatus 10. The optical detection device 100 can be attached to and detached from the display 220, and is electrically connected to the information processing device 200 via the USB cable USBC.

  As described above, according to the optical detection device 100 of the present embodiment, the dark current component and the default light component included in the light reception signal before correction can be reduced by performing the correction process by the correction unit 130. . Further, by performing the correction process by the correction unit 130, it is possible to increase the ratio of the signal level of the signal component effective for object detection to the dynamic range of the detection unit 110. As a result, it is possible to further increase the accuracy of detecting the position information of the object. Furthermore, when applied to a display system and an information processing system, for example, it becomes possible to accurately detect a character drawn by a user with a finger, so that information can be input to the information processing apparatus 200 using handwritten characters. It becomes possible.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configurations and operations of the optical detection device, the display system, and the information processing system are not limited to those described in this embodiment, and various modifications can be made.

EU irradiation unit, RU light receiving unit, LSU1, LSU2 first and second light source units,
LT, LT1, LT2 irradiation light, LR reflected light,
LG light guide, RS reflection sheet, PS prism sheet,
LF louver film, LE irradiation direction setting section,
LID1, LID2 First and second irradiation light intensity distributions, RDET detection area,
OB object, AMP1, AMP2 first and second amplifier circuits,
DF1, DF2 first and second differential signal generation circuits, HL holding circuit,
PD1, PD2 first and second light receiving elements,
10 display device, 20 display unit, 100 optical detection device, 110 detection unit,
120 control unit, 130 correction unit, 200 information processing device, 220 display

Claims (11)

An irradiation unit that emits irradiation light; and
A light receiving unit that receives reflected light by at least the reflected light being reflected by an object present in the detection area;
A correction unit that performs correction processing of a light reception signal from the light receiving unit;
A detection unit that detects position information of the object based on a light reception signal after correction from the correction unit;
The correction unit performs a correction process for reducing a dark current component and a default light component included in a light reception signal before correction based on a light reception signal in a state where the object does not exist in the detection area. Optical detection device. In claim 1,
The light receiving unit is
A first light receiving element for detecting the object and a second light receiving element for detecting dark current;
The correction unit is
As the light receiving signal, a first light receiving signal from the first light receiving element and a second light receiving signal from the second light receiving element are received.
An optical detection apparatus that performs the correction processing based on the first light reception signal and the second light reception signal. In claim 2,
The correction unit is
The correction processing is performed based on the default light component obtained from the difference between the first light receiving signal and the second light receiving signal and the dark current component obtained from the second light receiving signal. An optical detection device. In claim 3,
The correction unit is
A first difference signal generation circuit that generates a difference signal between a first signal corresponding to the first light reception signal and a second signal corresponding to the second light reception signal;
A holding circuit for holding the differential signal;
A second difference that generates a difference signal between the first signal corresponding to the first light reception signal and the holding signal held by the holding circuit and the second signal corresponding to the second light reception signal. An optical detection device comprising a signal generation circuit. In claim 4,
The correction unit is
A first amplifier circuit that amplifies the first light receiving signal and outputs the amplified signal as the first signal;
An optical detection apparatus comprising: a second amplification circuit that amplifies the second light receiving signal and outputs the amplified signal as the second signal. In claim 4 or 5,
The second differential signal generation circuit includes:
An optical detection apparatus that outputs the corrected light reception signal to the detection unit during an object detection period in which the object existing in the detection area is detected. In any one of Claims 4 thru | or 6.
The irradiation unit is
In the first period, the first irradiation light having the first irradiation light intensity distribution is emitted,
In the second period, the second irradiation light having a second irradiation light intensity distribution different from the first irradiation light intensity distribution is emitted,
The correction unit is
As the holding circuit,
A first holding circuit for holding the holding signal in the first period;
An optical detection device comprising: a second holding circuit that holds the holding signal in the second period. In any one of Claims 1 thru | or 6.
The irradiation unit is
In the first period, the first irradiation light having the first irradiation light intensity distribution is emitted,
In the second period, the optical detection device emits second irradiation light having a second irradiation light intensity distribution different from the first irradiation light intensity distribution. In any one of Claims 1 thru | or 8.
The irradiation unit is
A light source unit for emitting light source light;
A curved light guide for guiding the light source light from the light source section along a curved light guide path;
An irradiation direction setting unit that receives the light source light emitted from the outer peripheral side of the light guide and sets the irradiation direction of the irradiation light in a direction from the inner peripheral side to the outer peripheral side of the curved light guide An optical detection device. An optical detection device according to any one of claims 1 to 9,
A display system comprising: a display device that displays an image. An optical detection device according to any one of claims 1 to 9,
An information processing device that performs processing based on detection information from the optical detection device;
An information processing system comprising: a display device that displays an image based on image data from the information processing device.

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