WO2015137050A1

WO2015137050A1 - Optical position detection system, control apparatus, position detection apparatus, control program, and distance measuring system

Info

Publication number: WO2015137050A1
Application number: PCT/JP2015/054116
Authority: WO
Inventors: 延寿島村; 敏英三宅
Original assignee: 株式会社メガチップス
Priority date: 2014-03-14
Filing date: 2015-02-16
Publication date: 2015-09-17
Also published as: JP6355014B2; JP2015175712A

Abstract

Disclosed is an optical position detection system, wherein a position detection unit detects the position of a subject to be detected, said position being detected on the basis of electrical signals obtained by receiving, by means of a light receiving surface, light which has been radiated from the irradiation unit, and is reflected by means of the subject. A determining unit determines whether there is the subject or not on the basis of detection results obtained from the position detection unit. An operation control unit controls operation mode of the optical position detection system. The optical position detection system has: first operation mode, in which a lighting unit radiates light with a first light quantity; and second operation mode, in which the lighting unit radiates light with a second light quantity that is smaller than the first light quantity. In the cases where the determining unit determines that there is the subject, the operation control unit sets the operation mode to the first operation mode, and in the cases where the determining unit determines that there is no subject, the operation control unit sets the operation mode to the second operation mode.

Description

Optical position detection system, control device, position detection device, control program, and ranging system

The present invention relates to an optical detection technique.

Conventionally, various optical detection techniques have been proposed. Patent Document 1 proposes a system for optically detecting the position of a detection object.

JP 2013-88122 A

Now, for systems using optical detection technology, low power consumption is desired.

Therefore, the present invention has been made in view of the above points, and an object of the present invention is to provide a technique capable of reducing the power consumption of a system using an optical detection technique.

One aspect of the optical position detection system includes: an illumination unit that emits light; and an electric signal obtained by receiving the light reflected by the detection object on a light receiving surface, and A position detection unit that detects a position; a determination unit that determines presence / absence of the detection target based on a detection result of the position detection unit; and an operation control unit that controls an operation mode of the optical position detection system. The optical position detection system includes: a first operation mode in which the illumination unit emits light with a first light amount; and a second operation in which the illumination unit emits light with a second light amount less than the first light amount. The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit sets the detection target Was determined not to exist The case sets the operation mode to the second operation mode.

Further, one aspect of the optical position detection system includes: an illumination unit that emits light; and the detection target based on an electrical signal obtained by receiving the light reflected by the detection target on a light receiving surface. A position detection unit for detecting the position of an object, a determination unit for determining the presence or absence of the detection target based on a detection result of the position detection unit, and an operation control unit for controlling an operation mode of the optical position detection system The optical position detection system includes a first operation mode and a second operation mode in which a ratio of the irradiation time of the light in the illumination unit in a certain time is smaller than that of the first operation mode. When the determination unit determines that the detection target exists, the operation control unit sets the operation mode to the first operation mode, and the determination unit determines that the detection target does not exist. Judged Sets the operation mode to the second operation mode when the.

Further, one aspect of the control program is the position of the detection object based on an illumination unit that emits light and an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface. A control program for controlling an optical position detection system having a position detection unit for detecting the position of the optical position detection system, wherein the optical position detection system includes: (a) the detection target based on a detection result of the position detection unit; A step of determining the presence / absence of an object; and (b) when it is determined in step (a) that the detection target exists, the operation mode of the optical position detection system is set so that the illuminating unit uses the first light amount. A step of setting to a first operation mode for irradiating light; and (c) when it is determined in step (a) that the detection target does not exist, the operation mode is changed from the first light amount to the illumination mode. Less second light In is intended for executing a step of setting the second operating mode for emitting light.

Further, one aspect of the control program is the position of the detection object based on an illumination unit that emits light and an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface. A control program for controlling an optical position detection system having a position detection unit for detecting the position of the optical position detection system, wherein the optical position detection system includes: (a) the detection target based on a detection result of the position detection unit; A step of determining the presence or absence of an object, and (b) when it is determined in step (a) that the detection target exists, the operation mode of the optical position detection system is set to the light of the illumination unit. A step of setting the first operation mode in which the ratio of the irradiation time in a fixed time is a first rate; and (c) the operation when it is determined in step (a) that the detection target does not exist Mode It is intended for executing a step of setting the second operation mode in which a second proportion of the ratio of the irradiation time occupied in the certain time of the light is smaller than the first rate in the illumination unit.

Further, one aspect of the distance measurement system includes an illumination unit that emits light, and the distance measurement system based on an electrical signal obtained by receiving the light reflected by the detection target by a light receiving surface. A distance detection unit for detecting a distance to the detection target, a determination unit for determining the presence or absence of the detection target based on a detection result of the distance detection unit, and an operation for controlling an operation mode of the ranging system The distance measuring system includes: a first operation mode in which the illumination unit emits light with a first light amount; and a second operation in which the illumination unit emits light with a second light amount less than the first light amount. The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit detects the detection mode. When it is determined that the object does not exist Sets the operation mode to the second operation mode.

Further, one aspect of the distance measurement system includes an illumination unit that emits light, and the distance measurement system based on an electrical signal obtained by receiving the light reflected by the detection target by a light receiving surface. A distance detection unit for detecting a distance to the detection target, a determination unit for determining the presence or absence of the detection target based on a detection result of the distance detection unit, and an operation for controlling an operation mode of the ranging system And the distance measuring system has a first operation mode and a second operation mode in which a ratio of the irradiation time of the light in the illumination unit in a certain time is smaller than that of the first operation mode. When the determination unit determines that the detection target exists, the operation control unit sets the operation mode to the first operation mode, and the determination unit determines that the detection target does not exist. If judged Setting the operation mode to the second operation mode.

Further, one aspect of the control program is that an illumination unit that irradiates light and an electric signal obtained by receiving the light reflected by the detection target on the light receiving surface, from the detection target A control program for controlling a ranging system having a distance detecting unit for detecting a distance, wherein (a) presence / absence of the detection object is detected in the ranging system based on a detection result of the distance detecting unit. And (b) when it is determined in step (a) that the detection target exists, the operation mode of the distance measuring system is set, and the illumination unit irradiates light with a first light amount. A step of setting to one operation mode; and (c) a second light amount in which the illumination is less than the first light amount when it is determined in step (a) that the detection object does not exist. 2nd operation mode to irradiate light with It is intended for executing a step of setting the mode.

Further, one aspect of the control program is that an illumination unit that irradiates light and an electric signal obtained by receiving the light reflected by the detection target on the light receiving surface, from the detection target A control program for controlling a ranging system having a distance detecting unit for detecting a distance, wherein (a) presence / absence of the detection object is detected in the ranging system based on a detection result of the distance detecting unit. And (b) when it is determined in step (a) that the detection target exists, the operation mode of the optical position detection system is set to the irradiation time of the light in the illumination unit. A step of setting to a first operation mode in which a proportion occupied in a certain time is a first proportion; and (c) when it is determined in step (a) that the detection target does not exist, the operation mode is In the lighting section Irradiation time of the serial light is intended for executing a step of setting the second mode of operation the proportion in the certain time is the first second rate smaller than a rate of.

・ The power consumption of the system can be reduced.

The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

It is a figure which shows schematic structure of an optical position detection system. It is a figure for demonstrating operation | movement of an optical position detection system. It is a block diagram which shows the electric constitution of an optical position detection system. It is a figure which shows an example of a light-receiving part. It is a figure which shows the functional structure of a control part. It is a figure for demonstrating the process of a determination part. It is a figure which shows the structure of a 1st control part. It is a figure which shows a computing unit and an output terminal. It is a figure which shows the structure of a 2nd control part. It is a figure which shows an example of the control signal which an operation control part sends out. It is a figure which shows the timing chart of the optical position detection system which concerns on 1st embodiment. It is a figure for demonstrating the outline | summary of 2nd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 2nd embodiment. It is a figure for demonstrating the outline | summary of 3rd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 3rd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 3rd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 3rd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 3rd embodiment. It is a figure which shows the timing chart of the optical position detection system which concerns on 3rd embodiment. It is a figure which shows the calculator and output terminal which concern on 3rd embodiment modification. It is a figure which shows the calculator and output terminal which concern on 3rd embodiment modification. It is a figure which shows the calculator and output terminal which concern on 3rd embodiment modification. It is a block diagram which shows the electrical structure which concerns on a ranging system. It is a figure which shows the structure of a 1st control part. It is a figure for demonstrating the process of a determination part. It is a figure which shows an example of the control signal which an operation control part sends out.

<< Overview of optical position detection system >>
First, the configuration of the optical position detection system 1 common to the first to third embodiments described later will be described. FIG. 1 is a diagram showing a schematic configuration of an optical position detection system 1 according to the present embodiment. The optical position detection system 1 according to the present embodiment optically detects the position of a detection target 60 such as a human hand or a human finger. Hereinafter, the optical position detection system 1 may be referred to as “position detection system 1”.

As shown in FIG. 1, the outer shape of the position detection system 1 is a substantially rectangular parallelepiped. The position detection system 1 is provided with a window through which light passes. An illumination unit 2 and a light receiving unit 3 are provided inside the window. The length of the longest side of the outer shape of the position detection system 1 is, for example, about 10 mm.

In FIG. 1, for convenience, the position detection system 1 is shown in a size larger than the actual size. Moreover, the shape of the position detection system 1, the illumination part 2, and the light-receiving part 3 shown by FIG. 1 is an example. The shape of the position detection system 1, the illumination part 2, and the light-receiving part 3 is not restricted to the shape shown by FIG.

Next, a schematic operation of the position detection system 1 will be described with reference to FIGS. FIG. 2 is a diagram for explaining the operation of the position detection system 1.

First, the light 50 is irradiated from the illumination unit 2 (step S1 in FIG. 2). The light 50 irradiated by the illumination unit 2 is reflected by the detection target 60 and becomes reflected light 51 (step S2 in FIG. 2). Then, the reflected light 51 in step S2 is received by the light receiving unit 3 (step S3 in FIG. 2). Thereafter, the light receiving unit 3 converts the received reflected light 51 into an electric signal such as a current (photoelectric conversion), and outputs the electric signal (step S4 in FIG. 2). And the position detection system 1 calculates | requires the position of the detection target object 60 based on the electrical signal output from the light-receiving part 3 (step S5 of FIG. 2).

As described above, the position detection system 1 according to this embodiment detects the position of the detection target 60 in a non-contact manner. Based on the position of the detection object 60 continuously obtained by the position detection system 1, for example, the movement (gesture) of a human hand is detected without contact.

<About the electrical configuration of the optical position detection system>
FIG. 3 is a block diagram showing an electrical configuration of the position detection system 1. As shown in FIG. 3, the position detection system 1 includes an illumination unit 2, a light receiving unit 3, and a control unit 10.

The illumination unit 2 has an LED (Light Emitting Diode) 4 that is a light emitting element. It can be said that the illumination part 2 is also an illuminating device. The LED 4 is, for example, an infrared light emitting diode that emits light in the infrared region. However, the wavelength of the light 50 emitted from the illumination unit 2 (LED 4) only needs to include a wavelength that can be photoelectrically converted by the light receiving unit 3 (that is, a wavelength that can be detected by the light receiving unit 3). The light 50 emitted from the light source may be, for example, light other than the infrared region such as visible light. When the LED 4 is an infrared light emitting diode, the light 50 emitted from the illuminating unit 2 is not visible to the human eye, so that the use range of the position detection system 1 can be widened. Moreover, in this Embodiment, although the illumination part 2 is integrated with other components, such as the light-receiving part 3, the illumination part 2 may be provided separately from another component.

The light receiving unit 3 is, for example, a quadrant photodiode that is a light receiving element, and includes PDs (Photodiode) 5, 6, 7, and 8. The light receiving unit 3 can also be said to be a light receiving device. The PDs 5 to 8 are formed by dividing a light receiving surface formed on one semiconductor substrate into four. The light receiving unit 3 may not be a divided photodiode. In this case, the PDs 5 to 8 are formed on separate semiconductor substrates, for example.

FIG. 4 is a view showing a light receiving surface of the light receiving unit 3. PD 5 has a first light receiving surface 15, PD 6 has a second light receiving surface 16, PD 7 has a third light receiving surface 17, and PD 8 has a fourth light receiving surface 18. Yes. The PD 5 receives the reflected light 51 on the first light receiving surface 15 and converts the received reflected light 51 into a first electric signal. Similarly, the PD 6 receives the reflected light 51 at the second light receiving surface 16 and converts it into a second electrical signal, and the PD 7 receives the reflected light 51 at the third light receiving surface 17 and converts it into a third electrical signal. The PD 8 receives the reflected light 51 on the fourth light receiving surface 18 and converts it into a fourth electric signal. The first, second, third, and fourth electric signals generated by the

PDs

5, 6, 7, and 8 are output to the control unit 10. Hereinafter, when it is not necessary to distinguish the first electric signal, the second electric signal, the third electric signal, and the fourth electric signal, each is simply referred to as an “electric signal”.

As FIG. 4 shows, the 1st light-receiving surface 15, the 2nd light-receiving surface 16, the 3rd light-receiving surface 17, and the 4th light-receiving surface 18 are arrange | positioned on the same plane. A light receiving surface 14 is formed. More specifically, the first light receiving surface 15, the second light receiving surface 16, the third light receiving surface 17, and the fourth light receiving surface 18 are on the same plane so as to be adjacent to the other two light receiving surfaces. By being arranged around the point 19, one light receiving surface 14 is formed. In the example of FIG. 4, the first light receiving surface 15, the second light receiving surface 16, the third light receiving surface 17, and the fourth light receiving surface 18 are arranged counterclockwise in this order.

In the present embodiment, as shown in FIG. 4, the plane including the light receiving surface 14 is the xy coordinate plane. The origin of the xy coordinate plane is the reference point 19. The x-axis of the xy coordinate plane passes through the boundary between the first light receiving surface 15 and the fourth light receiving surface 18 and the boundary between the second light receiving surface 16 and the third light receiving surface 17. The y axis of the xy coordinate plane passes through the boundary between the first light receiving surface 15 and the second light receiving surface 16 and the boundary between the third light receiving surface 17 and the fourth light receiving surface 18. Furthermore, in the present embodiment, the axis in the direction perpendicular to the xy coordinate plane is the z axis. In the position detection system 1, the position of the detection target in the xyz orthogonal coordinate system including the x axis, the y axis, and the z axis is detected. The z coordinate value in the present embodiment is a value corresponding to the distance between the detection target 60 and the light receiving surface 14. In the following description, the z coordinate value will be described as an example in which the z coordinate value takes a larger value as the detection object 60 is located closer to the light receiving surface 14. However, the z coordinate value may be set so as to take a larger value as the detection object 60 is located farther from the light receiving surface 14.

In the present embodiment, the case where the light receiving unit 3 has four PDs will be described, but the number of PDs is not limited to this. For example, the light receiving unit 3 may include three PDs or five or more PDs. Further, the shapes and arrangement positions of the first to fourth light receiving surfaces shown in FIG. 4 are also an example. For example, each of the first light receiving surface 15, the second light receiving surface 16, the third light receiving surface 17, and the fourth light receiving surface 18 may have a fan shape and the light receiving surface 14 may have a circular shape. Further, the first light receiving surface 15, the second light receiving surface 16, the third light receiving surface 17, and the fourth light receiving surface 18 are not arranged around the reference point 19 as shown in FIG. You may arrange in a line along a direction. However, in this case, it becomes difficult to detect the position of the detection target 60 in the y-axis direction.

The control unit 10 obtains the position of the detection target 60 in the xyz orthogonal coordinate system based on the first to fourth electric signals output from the light receiving unit 3, and outputs a position signal indicating the position. Further, the control unit 10 comprehensively controls the operation of the position detection system 1 according to the position of the detection target 60 obtained based on the first to fourth electric signals.

<Block configuration of control unit>
FIG. 5 is a block diagram illustrating a configuration of the control unit 10. As shown in FIG. 5, the control unit (control circuit) 10 includes a first control unit (first control circuit) 11, a second control unit (second control circuit) 12 that controls the first control unit 11, and have. The first control unit 11 includes an instruction unit 20 and a position detection unit 21. The second control unit 12 includes a determination unit 22 and an operation control unit 23. The first control unit 11 detects the position of the detection target 60 mainly based on a control signal from the second control unit 12. That is, the first control unit 11 functions as a position detection device that detects the position of the detection object 60. On the other hand, the second control unit 12 controls the operation of the position detection system 1 mainly based on the detection result of the position of the detection target 60 in the first control unit 11. That is, the second control unit 12 functions as a control device that controls the operation of the position detection system 1. In the present embodiment, for example, each of the first control unit 11 and the second control unit 12 is configured by an LSI (Large Scale Integration).

The position detection unit 21 detects the position (coordinate value) of the detection target 60 based on the first to fourth electrical signals output from the light receiving unit 3. More specifically, when the magnitudes of the first to fourth electric signals (currents) are A to D, respectively, and the maximum values of the first to fourth electric signals are Amax, Bmax, Cmax and Dmax, respectively. The position detection unit 21 obtains the x-coordinate value x, the y-coordinate value y, and the z-coordinate value z of the detection target 60 using the following formulas (1) to (3). Note that the possible range of the x coordinate value x, the y coordinate value y, and the z coordinate value z is 0 to V _REF . Here, 0 and V _REF are the minimum value and the maximum value of the output value of the position detection unit 21, respectively.

In the present embodiment, the case where the position detection unit 21 detects (determines) the position of the detection target 60 using the above-described equations (1) to (3) will be described. Expressions used for detecting (an arithmetic expression for obtaining an x-coordinate value, a y-coordinate value, and a z-coordinate value) are not limited to this. The position detection unit 21 only needs to be able to detect the position of the detection target 60 based on the electrical signal output from the light receiving unit 3, and the position detection unit 21 according to the number and arrangement position of the PDs constituting the light receiving unit 3. The arithmetic expression used in 21 may be changed as appropriate.

The coordinate value of the detection object 60 detected by the position detection unit 21 is output to the outside of the determination unit 22 and the position detection system 1 included in the second control unit 12. The coordinate value output to the outside of the position detection system 1 is used, for example, for detecting a human hand movement (gesture) or a human hand speed.

The determination unit 22 determines whether or not the detection target 60 is present based on the coordinate value detected by the position detection unit 21. More specifically, the determination unit 22 determines whether or not the detection target 60 exists based on the z coordinate value output from the position detection unit 21. FIG. 6 is a diagram for explaining the processing in the determination unit 22.

First, the determination unit 22 acquires the z coordinate value detected by the position detection unit 21 (step S10). Then, the determination unit 22 compares the z coordinate value acquired in step S10 with a predetermined threshold value (step S11). For example, when the z coordinate value is larger than a predetermined threshold (Yes in Step S11), the determination unit 22 determines that the detection target 60 is present (Step S12). On the other hand, when the z coordinate value is smaller than the predetermined threshold (No in Step S11), the determination unit 22 determines that the detection target 60 does not exist (Step S13). That is, the determination unit 22 in the present embodiment determines that “the detection target object 60 exists” when the distance between the light receiving surface 14 and the detection target object 60 is shorter than the predetermined distance. Then, the determination unit 22 determines that “the detection target 60 does not exist” when the distance between the light receiving surface 14 and the detection target 60 is longer than a predetermined distance or when the detection target 60 is not detected. . The determination result in the determination unit 22 is output to the operation control unit 23. The predetermined threshold value used for determining whether or not the detection target 60 exists is determined by the environment in which the position detection system 1 is installed, the type of the detection target 60, and the like.

The operation control unit 23 generally controls the operation of the position detection system 1 by sending a control signal to the instruction unit 20. When the operation of the position detection system 1 is not paused, or when the operation of the position detection system 1 is not immediately after activation, the operation control unit 23 uses the determination result output from the determination unit 22 to use the position detection system 1. Set the operation mode. Then, the operation control unit 23 sends a control signal to the instruction unit 20 based on the set operation mode.

More specifically, the operation control unit 23 outputs a control signal for setting the operation mode of the position detection system 1 to the first operation mode when the determination unit 22 determines that the detection target 60 exists. Send it out. On the other hand, when the determination unit 22 determines that the detection target 60 does not exist, the operation control unit 23 sends a control signal for setting the operation mode of the position detection system 1 to the second operation mode. . In the second operation mode in which the detection target 60 does not exist and it is not necessary to perform the process of detecting the position of the detection target 60, the second operation mode needs to perform the process of detecting the position of the detection target 60. The power consumption of the position detection system 1 is reduced. Details of the first operation mode and the second operation mode will be described in detail in first to third embodiments described later.

The instruction unit 20 transmits instruction signals to the light receiving unit 3, the illumination unit 2, and the position detection unit 21 based on the control signal transmitted from the operation control unit 23 to control them.

Thus, in the present embodiment, the first control unit 11 detects the position of the detection target 60 and outputs the detection result to the second control unit 12. The second control unit 12 sends a control signal to the first control unit 11 based on the detection result of the detection target 60 output from the first control unit 11. As will be described later, the control signal sent from the second control unit 12 to the first control unit 11 includes first to third control signals.

<Configuration of the first control unit>
Here, the structure of the 1st control part 11 (position detection apparatus) is demonstrated. FIG. 7 is a diagram mainly illustrating an example of the configuration of the first control unit 11. As shown in FIG. 7, the first control unit 11 includes an LED driver 41, amplifiers 42a to 42d, an arithmetic unit (arithmetic circuit) 43, and a logic circuit 44. Capacitors 46a to 46d are connected to the amplifiers 42a to 42d, respectively. Hereinafter, when it is not necessary to particularly distinguish the amplifiers 42a to 42d, each is referred to as an “amplifier 42”. Further, when it is not necessary to particularly distinguish the capacitors 46a to 46d, each is referred to as a “capacitor 46”. Output terminals 47 a to 47 c are connected to the arithmetic unit 43. Hereinafter, when it is not necessary to particularly distinguish the output terminals 47a to 47c, each is referred to as an “output terminal 47”.

The LED driver 41 causes the LED 4 to emit light by applying a current to the LED 4 constituting the illumination unit 2. Thereby, light 50 is irradiated from LED4. A resistor 45 is connected to the LED driver 41. A current corresponding to the value of the resistor 45 flows through the LED 4.

The first to fourth electric signals output from the PDs 5 to 8 of the light receiving unit 3 are input to the

amplifiers

42a, 42b, 42c, and 42d, respectively. The amplifiers 42a to 42d amplify and output the input first to fourth electric signals, respectively. Specifically, each amplifier 42 subtracts the electric signal obtained by subtracting the electric signal accumulated in the capacitor 46 connected to the amplifier 42 from the electric signal output from the PD connected to the amplifier 42. Amplify and output. The computing unit 43 obtains the position of the detection target 60 based on the electrical signal output from each amplifier 42.

Here, the light received by the PD when the LED 4 irradiates the light 50 and the reflected light 51 from the detection object 60 enters the PD includes disturbance light such as sunlight in addition to the reflected light 51. Light having the same wavelength as the LED 4 (referred to as “steady light”) is also included. Therefore, if the amplifier 42 amplifies the electric signal output from the PD as it is, an electric signal corresponding to the light in which the steady light and the reflected light 51 are combined is output from the amplifier 42. When the computing unit 43 obtains the position of the detection target 60 based on the electrical signal affected by such stationary light, the correct position may not be obtained.

Therefore, in the present embodiment, an electrical signal output from the PD when the LED 4 (illumination unit 2) is not irradiating the light 50, that is, an electrical signal indicating the intensity of steady light is connected to the PD. It is accumulated in a capacitor 46 connected to the amplifier 42. Then, the amplifier 42, based on the electric signal output from the PD when the LED 4 emits the light 50 and the reflected light 51 from the detection target 60 is present, is stored in the capacitor 46 connected to the amplifier 42. The electric signal obtained by subtracting (electric signal indicating the intensity of stationary light) is amplified and output to the computing unit 43. As a result, the amplifier 42 outputs an electrical signal in which the influence of stationary light is reduced. That is, the corrected electric signal from the PD is output from the amplifier 42. Therefore, the accuracy of the position of the detection target 60 obtained by the calculator 43 is improved.

Hereinafter, unless otherwise specified, simply saying “first electric signal” means the corrected first electric signal output from the amplifier 42a. Further, simply speaking “second electric signal” means a corrected second electric signal output from the amplifier 42b. Further, simply speaking “third electric signal” means a corrected third electric signal output from the amplifier 42c. And simply speaking, “fourth electric signal” means the corrected fourth electric signal output from the amplifier 42d.

The computing unit 43 uses the electrical signals output from the

amplifiers

42a, 42b, 42c, and 42d when the LED 4 is irradiating the light 50, and the above-described equations (1) to (3) to detect objects. 60 positions are detected (obtained).

FIG. 8 is a diagram showing the computing unit 43 and the output terminal 47. As shown in FIG. 8, the computing unit 43 includes an x coordinate value computing unit 31, a y coordinate value computing unit 32, and a z coordinate value computing unit 33. The calculator 43 and the output terminal 47 function as the position detector 21 shown in FIG.

The x-coordinate value calculator 31 obtains the x-coordinate value of the detection object 60 using the electrical signals output from the amplifiers 42a to 42d and the above-described equation (1). The x-coordinate value obtained by the x-coordinate value calculator 31 is output from the output terminal 47 a to the outside of the second control unit 12 and the position detection system 1.

The y-coordinate value calculator 32 obtains the y-coordinate value of the detection target 60 using the electrical signals output from the amplifiers 42a to 42d and the above-described equation (2). The y coordinate value obtained by the y coordinate value calculator 32 is output from the output terminal 47 b to the outside of the second control unit 12 and the position detection system 1.

The z-coordinate value calculator 33 obtains the z-coordinate value of the detection target 60 using the electrical signals output from the amplifiers 42a to 42d and the above-described equation (3). The z coordinate value obtained by the z coordinate value calculator 33 is output from the output terminal 47 c to the outside of the second control unit 12 and the position detection system 1.

The logic circuit 44 functions as the instruction unit 20 shown in FIG. The logic circuit 44 sends an instruction signal corresponding to the control signals (first control signal, second control signal, and third control signal) sent from the operation control unit 23 to the LED driver 41,

amplifiers

42a, 42b, 42c, and 42d. And to the calculator 43.

<About the configuration of the second control unit>
Here, the configuration of the second control unit 12 (control device) will be described. The second control unit 12 is configured by, for example, a microcontroller (microcomputer) that is a kind of LSI. FIG. 9 is a diagram illustrating a configuration of the second control unit 12.

As shown in FIG. 9, the second control unit 12 includes a CPU (Central Processing Unit) 12a, a storage unit 12b, and the like. Various functions (determination part 22 and operation control part 23) of the 2nd control part 12 are realized when CPU12a runs control program 12c memorized by storage part 12b. The storage unit 12b is configured by a non-transitory recording medium that can be read by the CPU 12a, such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The storage unit 12b may include a computer-readable non-transitory recording medium other than the ROM and the RAM.

The circuit configuring the first control unit 11 and the circuit configuring the second control unit 12 may be formed on the same substrate or may be formed on different substrates. Moreover, the 1st control part 11 and the 2nd control part 12 may be accommodated in the same package, and may be accommodated in a different package.

Further, some functions of the first control unit 11 may be provided in the second control unit 12. For example, the position controller 21 of the first controller 11 may be provided in the second controller 12. Further, some functions of the second control unit 12 may be provided in the first control unit 11. For example, the determination unit 22 of the second control unit 12 may be provided in the first control unit 11.

<< First Embodiment >>
Here, the position detection system 1 according to the first embodiment will be described.

<Regarding the control signal sent out by the operation control unit>
FIG. 10 is a diagram illustrating an example of a control signal transmitted by the operation control unit 23. FIG. 10 shows a control signal (first control signal, second control signal, and third control signal) sent out by the operation control unit 23, an amplifier 42, a calculator 43 (x coordinate value calculator 31, y coordinate value calculator). 6 types of relationships with the state of the device 32 and the z-coordinate value calculator 33) and the LED driver 41 are shown. Each of the first control signal, the second control signal, and the third control signal is a binary signal, and indicates a signal level of either a high level or a low level. Then, the logic circuit 44 (instruction unit 20) outputs an instruction signal corresponding to a combination of signal levels indicated by the first control signal, the second control signal, and the third control signal output from the operation control unit 23, to the amplifier 42, The data is sent to the calculator 43 and the LED driver 41.

No. in FIG. As illustrated in FIG. 1, when the first and second control signals indicate a low level, the logic circuit 44 (instruction unit 20) includes the amplifier 42 regardless of the signal level of the third control signal. 42 is sent to the x coordinate value calculator 31, and an instruction signal to pause the operation of the x coordinate value calculator 31 is sent to the y coordinate value calculator 32. An instruction signal for stopping the operation of the coordinate value calculator 32 is sent, an instruction signal for stopping the operation of the z coordinate value calculator 33 is sent to the z coordinate value calculator 33, and an LED driver 41 is sent to the LED driver 41. An instruction signal to stop (turn off) the LED 4 (illumination unit 2) is sent. As a result, the operation of the position detection system 1 stops.

No. in FIG. 2, when the first control signal indicates a high level and the second control signal indicates a low level, the logic circuit 44 (instruction unit 20) regardless of the signal level of the third control signal. Sends an instruction signal to the amplifier 42 to set the operation mode of the amplifier 42 to the rapid charge mode, and an instruction signal to stop the operation of the x coordinate value calculator 31 to the x coordinate value calculator 31. And an instruction signal for stopping the operation of the y-coordinate value calculator 32 is sent to the y-coordinate value calculator 32, and the operation of the z-coordinate value calculator 33 is paused to the z-coordinate value calculator 33. The instruction signal is sent to the LED driver 41 to stop (turn off) the LED 4 (illumination unit 2).

When each amplifier 42 is set to the quick charge mode, the electric signal input from the PD connected to the amplifier 42 is rapidly stored in the capacitor 46 connected to the amplifier 42. As a result, an electrical signal output from the PD when the LED 4 is turned off, that is, an electrical signal indicating the intensity of steady light, is rapidly accumulated in the capacitor 46. No. The combination of control signals shown in 2 is used immediately after the position detection system 1 is activated.

No. in FIG. 3 and no. The combination of the control signals shown in 4 is used when the operation control unit 23 sets the operation mode of the position detection system 1 to the second operation mode based on the determination result output from the determination unit 22. That is, when the second control unit 12 determines that the detection target 60 does not exist, the No. 3 and no. The first to third control signals having the signal levels indicated by 4 are output, and the operation mode of the position detection system 1 is set to the second operation mode.

No. in FIG. 3, when both the first control signal and the second control signal indicate a high level and the third control signal indicates a low level, the logic circuit 44 (instruction unit 20) is connected to the amplifier 42. Sends an instruction signal for setting the operation mode of the amplifier 42 to the normal charge mode, sends an instruction signal to the x coordinate value calculator 31 to suspend the operation of the x coordinate value calculator 31, and An instruction signal to stop the operation of the y coordinate value calculator 32 is sent to the value calculator 32, and an instruction signal to stop the operation of the z coordinate value calculator 32 is sent to the z coordinate value calculator 33. Then, the LED driver 41 is sent an instruction signal to stop (turn off) the LED 4 (illumination unit 2).

When each amplifier 42 is set to the normal charge mode, the electric signal input from the PD connected to the amplifier 42 is stored in the capacitor 46 connected to the amplifier 42 at a normal speed. As a result, the capacitor 46 stores an electrical signal output from the PD when the LED 4 is turned off, that is, an electrical signal indicating the intensity of steady light.

No. in FIG. 4, when both the first control signal and the third control signal indicate a low level and the second control signal indicates a high level, the logic circuit 44 (instruction unit 20) is connected to the amplifier 42. Sends an instruction signal to set the operation mode of the amplifier 42 to the amplification mode, sends an instruction signal to stop the operation of the x coordinate value calculator 31 to the x coordinate value calculator 31, and sets the y coordinate value An instruction signal to stop the operation of the y coordinate value calculator 32 is sent to the calculator 32, and the z coordinate value calculator 33 is operated to the z coordinate value calculator 33 (that is, the z coordinate value is detected). An instruction signal indicating that the LED 4 (illumination unit 2) is lit with the second light amount. Here, the second light amount is smaller than the first light amount described later. That is, in this case, the LED driver 41 causes the LED 4 to emit light with a weaker current than when the LED 4 is lit with the first light amount.

When each amplifier 42 is set to the amplification mode, the electric signal stored in the capacitor connected to the amplifier 42 is subtracted from the electric signal input from the PD connected to the amplifier 42, thereby obtaining Amplified electrical signal is output.

Operation control unit 23 is No. First to third control signals shown in FIG. The operation mode of the position detection system 1 is set to the second operation mode by switching and transmitting the first to third control signals shown in 4 at a predetermined cycle. From the operation control unit 23, the No. When the control signal shown in FIG. 4 is transmitted, each amplifier 42 is accumulated in the capacitor 46 from the electrical signal output from the PD when the LED 4 is irradiating light (light 50) with the second light quantity. The electric signal indicating the intensity of the steady light is subtracted, and the electric signal obtained thereby is amplified and output. That is, each amplifier 42 corrects the electrical signal output from the PD when the LED 4 is irradiating the light 50 with the electrical signal indicating the intensity of the steady light, and amplifies the corrected electrical signal. Output. Then, the z-coordinate value calculator 33 obtains the position of the detection target 60 based on the electric signal output from each amplifier 42 in this way. Thereby, the z coordinate value calculator 33 can obtain the z coordinate value of the detection target 60 based on the electric signal indicating the intensity of the reflected light 51 received by each PD.

No. in FIG. 5 and no. 6 is used when the operation control unit 23 sets the operation mode of the position detection system 1 to the first operation mode based on the determination result output from the determination unit 22. That is, when the second control unit 12 determines that the detection target 60 is present, the No. 5 and no. The first to third control signals having the signal levels shown in FIG. 6 are output, and the operation mode of the position detection system 1 is set to the first operation mode.

No. in FIG. As illustrated in FIG. 5, when the first to third control signals indicate a high level, the logic circuit 44 (instruction unit 20) includes the amplifier 42, the x coordinate value calculator 31, and the y coordinate value calculator 32. , Z-coordinate value calculator 33 and LED driver 41 are respectively connected to No. 1 in FIG. The instruction signal similar to the instruction signal illustrated in FIG. As a result, no. 3, an electric signal indicating the intensity of steady light is accumulated in the capacitor 46.

No. in FIG. 6, when the first control signal indicates a low level and both the second control signal and the third control signal indicate a high level, the logic circuit 44 (instruction unit 20) is connected to the amplifier 42. Sends an instruction signal for setting the operation mode of the amplifier 42 to the amplification mode, sends an instruction signal for performing the operation of the x coordinate value calculator 31 to the x coordinate value calculator 31, and calculates the y coordinate value An instruction signal for performing the operation of the y coordinate value calculator 32 is transmitted to the device 32, and an instruction signal for performing the operation of the z coordinate value calculator 33 is transmitted to the z coordinate value calculator 33, and the LED driver. An instruction signal for turning on the LED 4 (illumination unit 2) with the first light amount is sent to 41. Here, the first light amount is larger than the second light amount. That is, in this case, the LED driver 41 causes the LED 4 to emit light with a larger current than when the LED 4 is lit with the second light amount.

Operation control unit 23 is No. The first to third control signals shown in FIG. The operation mode of the position detection system 1 is set to the first operation mode by switching the first to third control signals shown in FIG. In the first operation mode, each amplifier 42 corrects the electric signal output from the PD when the LED 4 is irradiating light (light 50) with the first light amount with an electric signal indicating the intensity of steady light. Then, the corrected electric signal is amplified and output. Then, the x-coordinate value calculator 31, the y-coordinate value calculator 32, and the z-coordinate value calculator 33 obtain the position of the detection target 60 based on the electrical signal output from each amplifier 42 in this way.

<Example of control by the operation control unit>
Here, a control example of the position detection system 1 by the operation control unit 23 will be described. FIG. 11 is a diagram illustrating an example of a timing chart of the position detection system 1. FIG. 11 shows the control signal sent from the operation control unit 23 and the outputs (light quantity and coordinate values) of the LED 4 and the calculator 43.

In the “control content” column shown in FIG. 11, the operation control unit 23 displays the No. shown in FIG. 1-No. 6 shows which control signal is being transmitted. Here, for example, during the period in which two numbers (No. 3 and No. 4) are indicated, such as “No. 3 and the control signal shown in No. 3; 4 represents that the control signal shown in FIG. 4 is switched and transmitted at a predetermined cycle. The “first control signal”, “second control signal”, and “third control signal” columns are signals indicated by the first control signal, the second control signal, and the third control signal sent by the operation control unit 23. Represents each level.

In the column “LED light quantity”, the light quantity emitted from the LED 4 is shown. FIG. 11 shows that the larger the value of the LED light quantity, the more light is emitted from the LED 4. That is, as the value of the LED light quantity is larger, the LED driver 41 lights the LED 4 with a larger current. Further, when the value of the LED light amount is the smallest, the LED 4 is turned off. In FIG. 11, “lights off (when control signals shown in No. 1, 2, 3, 5 are sent)” and “lights up with the second light quantity (when control signals shown in No. 4 are sent). ) "And" Lighting with the first light quantity (when the control signal shown in No. 6 is sent) "are shown.

The “x coordinate value”, “y coordinate value”, and “z coordinate value” fields are respectively obtained by the calculator 43 (x coordinate value calculator 31, y coordinate value calculator 32, and z coordinate value calculator 33). The coordinate values obtained are shown.

Further, a dotted line 61 shown in the column of “z coordinate value” indicates a predetermined threshold value used for determining whether or not the detection target 60 exists. The determination unit 22 determines that the detection target 60 is present when the z coordinate value is larger than the dotted line 61 (predetermined threshold). Conversely, the determination unit 22 determines that the detection target 60 does not exist when the z coordinate value is smaller than the dotted line 61.

In the example of FIG. 11, the operation of the position detection system 1 is paused at first. In this case, the first to third control signals output from the operation control unit 23 indicate a low level (control signal indicated by No. 1 in FIG. 10), the LED 4 is turned off, and the computing unit 43 receives each coordinate. The value cannot be obtained.

When the operation of the position detection system 1 is in a dormant state, for example, when the position detection system 1 receives an instruction to start the operation of the position detection system 1 from the user, the operation control unit 23 2 is transmitted. No. When the control signal shown in FIG. 2 is sent, each amplifier 42 is set to the quick charge mode, and the capacitor 46 rapidly stores an electric signal indicating the intensity of steady light.

When the electric signal indicating the intensity of the steady light is accumulated in the capacitor 46, as shown in FIG. 3 and no. 4 is sent out. That is, the operation control unit 23 sets the operation mode of the position detection system 1 to the second operation mode. From the operation control unit 23, the No. When the control signal shown in FIG. 4 is transmitted, as described above, the LED 4 is lit with the second light amount smaller than the first light amount, and the x coordinate value calculator 31 and the y coordinate value calculator 32 pause the operation. The z-coordinate value calculator 33 calculates the z-coordinate value.

Here, when the z coordinate value calculated by the z coordinate value calculator 33 is smaller than the dotted line 61 (predetermined threshold value), the determination unit 22 determines that the detection target 60 does not exist. In this case, the second operation mode is continued. In the example shown in FIG. 11, the z coordinate value obtained for the first time and the second time in the section where the operation mode of the position detection system 1 is set to the second operation mode is based on the dotted line 61 (predetermined threshold value). Small value. Therefore, the second operation mode is continued.

On the other hand, when the z coordinate value calculated by the z coordinate value calculator 33 is larger than the dotted line 61 (predetermined threshold value), the determination unit 22 determines that the detection object 60 exists. In this case, the operation control unit 23 sets (changes) the operation mode of the position detection system 1 to the first operation mode. In the example shown in FIG. 11, the z coordinate value obtained for the third time in a section where the operation mode of the position detection system 1 is set to the second operation mode is larger than the dotted line 61 (predetermined threshold value). For this reason, the operation mode of the position detection system 1 is changed to the first operation mode.

When the operation mode of the position detection system 1 is set to the first operation mode, as shown in FIG. 5 and no. 6 is sent out. From the operation control unit 23, the No. When the control signal shown in FIG. 6 is sent, as described above, the LED 4 is lit with the first light amount (> second light amount), the x coordinate value calculator 31 calculates the x coordinate value, and y The coordinate value calculator 32 calculates the y coordinate value, and the z coordinate value calculator 33 calculates the z coordinate value.

The first operation mode is continued until the z coordinate value calculated by the z coordinate value calculator 33 becomes smaller than the dotted line 61 (predetermined threshold value). When the z coordinate value calculated by the z coordinate value calculator 33 is smaller than the dotted line 61 (predetermined threshold value), the determination unit 22 determines that the detection target 60 does not exist, and the operation control unit 23 according to the determination result. Sets (changes) the operation mode of the position detection system 1 to the second operation mode. Thereafter, similarly, in the position detection system 1, the operation control unit 23 switches between the first operation mode and the second operation mode based on the determination result by the determination unit 22.

As described above, in the position detection system 1 according to the present embodiment, when the detection target 60 is not present, the illumination unit 2 uses a smaller amount of light (weak light) than when the detection target 60 is present. Irradiate light 50. Therefore, power consumption of the illuminating unit 2 can be reduced as compared with the case where the illuminating unit 2 irradiates the light 50 with a constant light amount regardless of whether or not the detection target 60 exists. As a result, the position detection system 1 can be reduced in power consumption.

In the position detection system 1 according to the present embodiment, when the detection target 60 does not exist, only the z coordinate value calculator 33 operates in the calculator 43 (that is, only the z coordinate value is obtained). The power consumption of the computing unit 43 can be reduced. That is, the power consumption of the position detection unit 21 can be reduced. As a result, the position detection system 1 can further reduce power consumption.

In the second operation mode, the calculator 43 may obtain not only the z coordinate value but also one of the x coordinate value and the y coordinate value. Even in this case, in the second operation mode, one of the three coordinate values (x coordinate value, y coordinate value, and z coordinate value) cannot be obtained. The power consumption of the detection system 1 can be reduced.

In the second operation mode, the computing unit 43 may obtain all of the x coordinate value, the y coordinate value, and the z coordinate value. Even in this case, it is possible to reduce the power consumption of the position detection system 1 by reducing the amount of the light 50 emitted from the illumination unit 2 in the second operation mode.

In the second operation mode, only the z coordinate value may be obtained without reducing the amount of light of the illumination unit 2. Alternatively, in the second operation mode, the z-coordinate value and one of the x-coordinate value and the y-coordinate value may be obtained without reducing the light amount of the light 50 irradiated by the illumination unit 2. Even in this case, it is possible to reduce the power consumption of the position detection system 1.

In addition, when the detection target 60 does not exist (when the operation mode of the position detection system 1 is the second operation mode), the z coordinate value calculator 33 is an arithmetic expression represented by the above expression (3). A value obtained by multiplying the obtained value by a predetermined number may be output as the z coordinate value. Thereby, even if it is a case where the illumination part 2 is irradiating with weak light in a 2nd operation mode, a large z coordinate value can be obtained. Therefore, the determination unit 22 can easily determine the presence or absence of the detection target 60.

<< Second Embodiment >>
In the second embodiment, when the operation mode of the position detection system 1 is set to the second operation mode, the irradiation time of the LED 4 (illumination unit 2) is shortened to reduce the power consumption of the position detection system 1. To do. The remaining configuration of the position detection system 1 in the second embodiment is the same as that in the first embodiment.

FIG. 12 is a diagram for explaining the irradiation time of the illumination unit 2 in the present embodiment. In FIG. 12, when the operation mode of the position detection system 1 is set to the second operation mode (that is, when the detection target 60 is not present), the irradiation pattern of the illumination unit 2 and the first operation mode are set. Are shown side by side with the irradiation pattern of the illuminating unit 2 when the detection target 60 is present (that is, when the detection target 60 is present).

As shown in FIG. 12, when the detection target 60 does not exist, the illumination unit 2 irradiates the light 50 for a time of 2 times, that is, 2a (> a) in a certain time interval P. . On the other hand, when the detection target 60 is present, the illuminating unit 2 irradiates the light 50 in the time interval P for four times, that is, for 4a. That is, in the present embodiment, the proportion of the irradiation time of the illumination unit 2 in the fixed time (time interval P) is smaller when the detection target 60 is not present than when the detection target 60 is present. It has become. Thus, in this Embodiment, when the detection target object 60 does not exist, the power consumption of the illumination part 2 is reduced by shortening the irradiation time of LED4 (illumination part 2). As a result, the position detection system 1 can be reduced in power consumption.

In the example shown in FIG. 12, the ratio of the time during which the illumination unit 2 irradiates light in the period in which the illumination unit 2 irradiates the light 50 between the first operation mode and the second operation mode (hereinafter, Simply called “duty ratio”). More specifically, in the example shown in FIG. 12, the irradiation period T2 of the illumination unit 2 at the time of setting the second operation mode is set longer than the irradiation period T1 of the illumination unit 2 at the time of setting the first operation mode. The duty ratio at the time of setting the second operation mode is made smaller than the duty ratio at the time of setting the first operation mode. However, as in the example shown in FIG. 12, it is not always necessary to change both the irradiation cycle and the duty ratio. The ratio of the illumination time of the illumination unit 2 in the fixed time in the second operation mode only needs to be smaller than the ratio of the illumination time of the illumination unit 2 in the fixed time in the first operation mode. For example, the irradiation cycle is constant In this case, only the irradiation time may be changed, or the irradiation time may be constant and only the irradiation period may be changed.

FIG. 13 corresponds to FIG. 10 and shows an example of a timing chart of the position detection system 1 in the present embodiment. As shown in FIG. 13, the calculator 43 (the x coordinate value calculator 31, the y coordinate value calculator 32, and the z coordinate value calculator 33) displays the coordinate value when the LED 4 is irradiating the light 50. Ask.

In the example shown in FIG. 13, the duty ratio of the illumination unit 2 when the detection target object 60 does not exist (when the second operation mode is set) is the same as when the detection target object 60 exists (when the first operation mode is set). By making it smaller than the duty ratio of the illuminating unit 2, the time for the illuminating unit 2 to irradiate the light 50 is shortened (more specifically, the total irradiation time of the illuminating unit 2 within a certain time is shortened). is doing). By shortening the time during which the illumination unit 2 irradiates the light 50, the power consumption in the illumination unit 2 can be reduced, and the position detection system 1 can be reduced in power consumption.

In the example shown in FIG. 13, the amount of light 50 irradiated by the illumination unit 2 in the second operation mode is reduced as in the first embodiment, but it may not be reduced. Even in this case, the illumination unit 2 in the second operation mode is set to be shorter than the illumination time in the illumination unit 2 at the time of setting the first operation mode by setting the irradiation time at the illumination unit 2 at the time of setting the second operation mode. 2 can be reduced. In the second operation mode, all of the x coordinate value, the y coordinate value, and the z coordinate value may be obtained as in the first operation mode. Even in this case, the illumination unit 2 in the second operation mode is set to be shorter than the illumination time in the illumination unit 2 at the time of setting the first operation mode by setting the irradiation time at the illumination unit 2 at the time of setting the second operation mode. 2 can be reduced.

<< Third embodiment >>
In the third embodiment, when the operation mode of the position detection system 1 is set to the first operation mode, the calculator 43 (x coordinate value calculator 31, y coordinate value calculator 32, and z coordinate value calculator 33). ) Reduces the power consumption of the position detection system 1 by obtaining at least one of the x-coordinate value, the y-coordinate value, and the z-coordinate value in a cycle longer than the cycle in which the LED 4 (illumination unit 2) irradiates the light 50 ing.

FIG. 14 is a diagram illustrating an example of coordinate values calculated and output by the position detection unit 21 (the arithmetic unit 43 and the output terminal 47) in the first operation mode. The numbers shown on the horizontal axis in FIG. 14 are determined for convenience, and after the operation mode of the position detection system 1 is set to the first operation mode, the operation control unit 23 sets No. 1 for the first time. The time when the control signal shown in FIG. In the lower column of “First time”, the No. 6 shows the types of coordinate values calculated and output by the position detector 21 based on the control signal shown in FIG. Thereafter, the operation control unit 23 changes the No. Each time the control signal shown in FIG. 6 is sent out, the number increases as the second time, the third time,.

As shown in FIG. When the control signal shown in FIG. 6 is sent, the position detector 21 calculates and outputs the x coordinate value and the z coordinate value. Subsequently, No. When the control signal shown in FIG. 6 is sent, the position detector 21 calculates and outputs the y coordinate value and the z coordinate value. And No. 3 for the third time. When the control signal shown in FIG. 6 is sent out, the position detection unit 21 calculates and outputs the x-coordinate value and the z-coordinate value as in the first time. When the control signal shown in FIG. 6 is sent out, the position detection unit 21 calculates and outputs the y coordinate value and the z coordinate value as in the second time.

In this way, from the operation control unit 23, no. 6 is an odd number such as the first time, the third time,..., The position detection unit 21 calculates and outputs “x coordinate value and z coordinate value”. On the other hand, from the operation control unit 23, the No. When the number of times the control signal shown in FIG. 6 is sent is an even number such as the second time, the fourth time,..., The position detection unit 21 calculates and outputs “y coordinate value and z coordinate value”. In other words, in the example illustrated in FIG. 14, the position detection unit 21 alternately calculates and outputs the x coordinate value and the y coordinate value.

After the first operation mode is set, the operation control unit 23 sets No. When the control signal shown in FIG. 6 is transmitted, the instruction unit 20 transmits a first instruction signal for calculating the x-coordinate value and the z-coordinate value to the computing unit 43 (more specifically, the x-coordinate value). An instruction signal for performing the operation is sent to the value calculator 31 and the z coordinate value calculator 33, and an instruction signal for stopping the operation is sent to the y coordinate value calculator 32). Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly sent, a second instruction signal for calculating the y coordinate value and the z coordinate value is sent to the computing unit 43 (more specifically, the x coordinate value computing unit). 31), an instruction signal to stop the operation is sent to the y-coordinate value calculator 32 and the z-coordinate value calculator 33. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly transmitted, the first instruction signal is transmitted. Thereafter, the instructing unit 20 operates in the same manner, and the operation control unit 23 makes a No. The first instruction signal and the second instruction signal are alternately transmitted by transmitting one of the first and second instruction signals every time the control signal shown in FIG. 6 is transmitted.

FIG. 15 is a diagram showing a timing chart of the position detection system 1 in the third embodiment. Since the instruction unit 20 alternately sends the first instruction signal and the second instruction signal, as shown in FIG. 15, the computing unit 43 has the x coordinate value, the z coordinate value, the y coordinate value, and the z coordinate value. The coordinate value is obtained alternately. Thereby, in the position detection system 1, each of the x coordinate value and the y coordinate value is obtained at intervals longer than the cycle in which the illumination unit 2 irradiates the light 50.

Thus, in the position detection system 1 according to the present embodiment, the x-coordinate value and the y-coordinate value that are not used for determining whether or not the detection target 60 exists are longer than the cycle in which the illumination unit 2 irradiates light. The z coordinate value used for determining whether or not the detection object 60 exists is obtained at the same interval as the cycle in which the illumination unit 2 irradiates the light 50. Thereby, the power consumption in the calculator 43 (position detection part 21) can be reduced, without delaying the determination whether the detection target object 60 exists. As a result, the position detection system 1 can be reduced in power consumption.

In the above example, the x coordinate value and the y coordinate value are obtained alternately, but may be obtained at the same timing as shown in FIG. In the example of FIG. 16, after the instruction unit 20 is set to the first operation mode, the operation control unit 23 sets No. When the control signal shown in FIG. 6 is transmitted, a first instruction signal for calculating the x coordinate value, the y coordinate value, and the z coordinate value is transmitted to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly sent, a second instruction signal for calculating the z coordinate value is sent to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly transmitted, the first instruction signal is transmitted. Thereafter, the instruction unit 20 operates in the same manner, and alternately sends the first instruction signal and the second instruction signal.

In the above example, the x coordinate value and the y coordinate value are obtained at intervals longer than the cycle in which the illumination unit 2 emits the light 50. However, at least one of the x coordinate value, the y coordinate value, and the z coordinate is If the illumination unit 2 is obtained at intervals longer than the period in which the light 50 is irradiated, the position detection system 1 can be reduced in power consumption.

FIG. 17 is a diagram illustrating an example of a timing chart of the position detection system 1 when only the x-coordinate value is obtained at an interval longer than the cycle in which the illumination unit 2 irradiates the light 50. In the example of FIG. 17, after the instruction unit 20 is set to the first operation mode, the operation control unit 23 sets No. When the control signal shown in FIG. 6 is transmitted, a first instruction signal for calculating the x coordinate value, the y coordinate value, and the z coordinate value is transmitted to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When a control signal shown in FIG. 6 is newly sent, a second instruction signal for calculating the y coordinate value and the z coordinate value is sent to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly transmitted, the first instruction signal is transmitted. Thereafter, the instruction unit 20 operates in the same manner, and alternately sends the first instruction signal and the second instruction signal.

FIG. 18 is a diagram illustrating an example of a timing chart of the position detection system 1 in a case where only the z coordinate value is obtained at an interval longer than the cycle in which the illumination unit 2 irradiates the light 50. In the example of FIG. 18, after the instruction unit 20 is set to the first operation mode, the operation control unit 23 sets No. When the control signal shown in FIG. 6 is transmitted, a first instruction signal for calculating the x coordinate value, the y coordinate value, and the z coordinate value is transmitted to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When a control signal shown in FIG. 6 is newly transmitted, a second instruction signal for calculating the computing unit 43x coordinate value and y coordinate value is transmitted. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly transmitted, the first instruction signal is transmitted. Thereafter, the instruction unit 20 operates in the same manner, and alternately sends the first instruction signal and the second instruction signal.

FIG. 19 is a diagram illustrating an example of a timing chart of the position detection system 1 when all of the x-coordinate value, the y-coordinate value, and the z-coordinate value are obtained at intervals longer than the cycle in which the illumination unit 2 irradiates the light 50. is there. In the example of FIG. 19, after the instruction unit 20 is set to the first operation mode, the operation control unit 23 sets No. When the control signal shown in FIG. 6 is sent, a first instruction signal for calculating the x-coordinate value is sent to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly sent, a second instruction signal for calculating the y-coordinate value is sent to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly sent, a third instruction signal for calculating the z coordinate value is sent to the computing unit 43. Thereafter, the instruction unit 20 receives a No. from the operation control unit 23. When the control signal shown in FIG. 6 is newly transmitted, the first instruction signal is transmitted. Thereafter, the instruction unit 20 operates in the same manner, and alternately sends the first instruction signal, the second instruction signal, and the third instruction signal.

As described above, the x coordinate value, the y coordinate value, and the z coordinate value are all obtained at intervals longer than the period in which the illumination unit 2 irradiates the light 50, and thus consumed by the computing unit 43 (position detection unit 21). Electric power can be greatly reduced.

Further, as shown in FIGS. 15 and 19, when the x coordinate value and the y coordinate value are obtained at different timings, it is possible to use a common arithmetic unit for obtaining the x coordinate value and the y coordinate value. . FIG. 20 is a diagram illustrating a configuration of the position detection unit 21 when the arithmetic circuit for obtaining the x coordinate value and the y coordinate value is shared. The first calculator 35 shown in FIG. 20 can obtain both the x coordinate value and the y coordinate value.

Here, when the calculation formula (1) for calculating the x coordinate value is compared with the calculation formula (2) for calculating the y coordinate value, only one value in the addition formula existing in the numerator is different. It is. In other words, it is common to change whether the fourth electric signal or the second electric signal is input to one input terminal of the two-input adder circuit for obtaining the value of the numerator addition formula. The x-coordinate value and the y-coordinate value can be obtained using the above computing unit (arithmetic circuit).

The first calculator 35 shown in FIG. 20 is a calculator common to the x coordinate value and the y coordinate value. Then, the first selector 36 in the first stage of the first computing unit 35 is connected to one input terminal of the 2-input adding circuit for obtaining the value of the numerator addition formula in the first computing unit 35 with respect to the fourth input terminal. It is switched between inputting an electric signal and inputting a second electric signal. That is, the first selector 36 selects the fourth electric signal and inputs it to one input terminal of the adder circuit when the computing unit 43 obtains the x coordinate value. On the other hand, the first selector 36 selects the second electric signal and inputs it to one input terminal of the adder circuit when the calculator 43 obtains the y coordinate value. Note that the first electric signal is input to the other input terminal of the adder circuit.

When the x-coordinate value is output from the first calculator 35, the second selector 37 provided at the subsequent stage of the first calculator 35 outputs the x-coordinate value to the output terminal 47a. When the y coordinate value is output, the y coordinate value is output to the output terminal 47b.

Thus, the configuration of the position detection unit 21 can be simplified by using a common computing unit for obtaining the x coordinate value and the y coordinate value. As a result, it is possible to reduce the area of the circuit that realizes the position detection unit 21 and to reduce the cost of the position detection unit 21.

In FIG. 20, the example in which the x-coordinate value calculator 31 and the y-coordinate value calculator 32 are shared has been described, but the type of the calculation circuit to be shared is not limited to this. The type of the arithmetic circuit to be shared can be determined according to the arithmetic expression used to obtain each coordinate value. Since a plurality of arithmetic expressions for obtaining at least two coordinate values of the x coordinate value, the y coordinate value, and the z coordinate value are the same as the expressions (1) and (2) only by changing the value to be substituted. If there is, it is possible to use a common computing unit for computing the at least two coordinate values.

Further, in the case where an arithmetic unit for obtaining the x coordinate value and the y coordinate value is made common, as shown in FIG. 21, an output terminal for outputting the x coordinate value and the y coordinate value may be made common. Thus, the configuration of the position detection unit 21 can be further simplified.

As shown in FIG. 19, when the x coordinate value, the y coordinate value, and the z coordinate value are calculated at different timings, as shown in FIG. 22, the x coordinate value, the y coordinate value, and the z coordinate value are calculated. An output terminal for outputting coordinate values may be shared. The second selector 38 subsequent to the first calculator 35 and the z-coordinate value calculator 33 outputs the x-coordinate value to the output terminal 47a when the x-coordinate value is output from the first calculator 35. Further, when the y coordinate value is output from the first computing unit 35, the second selector 38 outputs the y coordinate value to the output terminal 47a. Then, when the z coordinate value is output from the z coordinate value calculator 33, the second selector 38 outputs the z coordinate value to the output terminal 47a.

Thus, the configuration of the position detection unit 21 can be further simplified by using a common output terminal for outputting the x coordinate value, the y coordinate value, and the z coordinate value.

<< Modification >>
<About ranging system>
The contents of the first embodiment and the second embodiment described above can be applied not only to the position detection system 1 but also to a distance measuring system. FIG. 23 is a diagram illustrating a configuration of the distance measuring system 70.

The ranging system 70 includes an illumination unit 2, a light receiving unit 3, and a control unit 10, and detects the distance between the ranging system and the detection target 60. The distance measuring system 70 irradiates the light 50 from the illuminating unit 2, and the light (reflected light 51) reflected by the detection target 60 is received by the light receiving unit 3. In the distance measuring system 70, the control unit 10 detects the distance between the distance measuring system 70 and the detection target 60 based on the electrical signal obtained by receiving the reflected light 51 by the light receiving unit 3. The distance measurement system 70 is different from the position detection system 1 that detects the position (coordinate value) of the detection object 60 in that the distance between the distance measurement system 70 and the detection object 60 is detected. The distance measuring system 70 is mounted on an imaging device, for example. In the imaging apparatus equipped with the ranging system 70, the detection target 60 is automatically focused based on the distance between the ranging system 70 and the detection target 60 detected by the ranging system 70. be able to.

In the distance measuring system 70, as shown in FIG. 23, not the position detecting unit 21 (see FIG. 5) but a distance detecting unit 26 for detecting the distance between the distance measuring system 70 and the detection target 60 is provided. In the distance measuring system 70, the determination unit 22 determines whether or not the detection target 60 exists based on the distance detected by the distance detection unit 26, not based on the coordinate value. The first control unit 11 having the distance detection unit 26 mainly detects the distance between the ranging system 70 and the detection object 60 based on the control signal from the second control unit 12. That is, the first control unit 11 having the distance detection unit 26 functions as a distance measuring device that detects the distance between the distance measuring system 70 and the detection target 60. The remaining configuration of the ranging system 70 is the same as that of the position detection system 1.

The distance detection unit 26 detects the distance between the ranging system 70 and the detection target 60 based on the electrical signal output from the light receiving unit 3. More specifically, the distance detection unit 26 is the time from when the illumination unit 2 irradiates the light 50 to when the light 50 is reflected by the detection target 60 and received by the light receiving unit 3, or the light reception The incident angle or the like of the reflected light 51 received by the unit 3 is obtained using the electrical signal output from the light receiving unit 3 and a predetermined arithmetic expression, and the distance detection unit 26 obtains the obtained time or the Based on the incident angle or the like, the distance between the distance measuring system 70 and the detection object 60 is detected. In the distance detection unit 26, a predetermined arithmetic expression used when calculating the distance between the distance measurement system 70 and the detection target 60 is selected according to the number of PDs constituting the light receiving unit 3, the arrangement position, and the like.

FIG. 24 is a diagram illustrating a configuration of the first control unit 11 of the ranging system 70 corresponding to the configuration diagram of the first control unit 11 according to the position detection system 1 illustrated in FIG. 7. In the first control unit 11 illustrated in FIG. 24, the computing unit 43 and the output terminal 47 a function as the distance detection unit 26. The computing unit 43 detects the distance between the distance measuring system 70 and the detection target 60 based on the electrical signals output from the

amplifiers

42a, 42b, 42c, and 42d when the LED 4 is irradiating the light 50 ( Ask). Further, since there is only one type of information detected by the calculator 43 (only the distance between the distance measuring system 70 and the detection object 60), the calculator 43 is connected to one output terminal 47a. The distance between the distance measuring system 70 and the detection object 60 detected by the computing unit 43 is output from the output terminal 47a to the outside of the second control unit 12 and the distance measuring system 70.

The determination unit 22 of the ranging system 70 determines whether or not the detection target 60 exists based on the distance between the ranging system 70 and the detection target 60 detected by the distance detection unit 26. FIG. 25 is a diagram illustrating processing of the determination unit 22 according to the distance measuring system 70 corresponding to the processing of the determination unit 22 according to the position detection system 1 illustrated in FIG. 6.

The determination unit 22 according to the present modification first acquires the distance detected by the distance detection unit 26 (step S20). And the determination part 22 compares the distance acquired by step S20, and a predetermined threshold value (step S21). For example, when the distance acquired in step S20 is larger than a predetermined threshold, that is, when the detection target 60 does not exist within the predetermined distance (Yes in step S11), the determination unit 22 has the detection target 60 present. It is determined not to be performed (step S22). On the other hand, when the distance acquired in step S20 is smaller than the predetermined threshold, that is, when the detection target 60 is within the predetermined distance (No in step S11), the determination unit 22 It determines with the target object 60 existing (step S23). The determination result in the determination unit 22 is output to the operation control unit 23.

The operation control unit 23 of the distance measurement system 70 sets the operation mode of the distance measurement system 70 using the determination result output from the determination unit 22, and sends a control signal to the instruction unit 20 based on the operation mode. . The ranging system 70 includes a first operation mode that is set when the determination unit 22 determines that the detection target 60 exists, and the determination unit 22, as in the first and second embodiments described above. A second operation mode that is set when it is determined that the detection object 60 does not exist.

<Example of control by the operation control unit>
FIG. 26 is a diagram illustrating an example of a control signal sent out by the operation control unit 23 according to the present modification corresponding to the control signal sent out by the operation control unit 23 of the position detection system 1 shown in FIG.

As described above, only the distance between the distance measuring system 70 and the detection object 60 is output from the computing unit 43 according to this modification. Therefore, unlike the first embodiment, even when the detection object 60 does not exist (when the operation mode of the distance measuring system 70 is set to the second operation mode), it is detected by the computing unit 43. The type of information does not change. That is, as shown in FIG. 26, the computing unit 43 according to this modification example, regardless of whether the operation mode of the distance measuring system 70 is set to the first operation mode or the second operation mode. When the LED 4 (illumination unit 2) irradiates the light 50, the distance between the distance measuring system 70 and the detection target 60 is detected.

On the other hand, when the operation mode of the ranging system 70 is the second operation mode, that is, when the detection target 60 does not exist within the predetermined distance, the LED driver 41 is similar to the above-described first embodiment. 2 is turned on with weak light (second light amount less than the first light amount). Therefore, the power consumption of the illumination unit 2 can be reduced as compared with the case where the light 50 is irradiated with a constant light amount regardless of the presence or absence of the detection target 60. As a result, the distance measurement system 70 can be reduced in power consumption.

Note that when the detection object 60 does not exist (when the operation mode of the distance measurement system 70 is the second operation mode), the calculator 43 calculates the distance measurement system 70 obtained based on the electrical signal from the amplifier 42. A value obtained by multiplying the distance to the detection target 60 by a predetermined number may be output as the distance between the distance measurement system 70 and the detection target 60. Thereby, even when the illumination part 2 is irradiating with the weak light in a 2nd operation mode, the detection result of a big value can be obtained and it becomes easy to determine the presence or absence of the detection target object 60 in the determination part 22. FIG.

Further, when the operation mode of the distance measuring system 70 is set to the second operation mode, the distance measuring system 70 is shortened by shortening the irradiation time of the LED 4 (illumination unit 2) as in the second embodiment. The power consumption may be reduced. As described in the second embodiment, the irradiation time of the illumination unit 2 can be changed by changing at least one of the irradiation period and the duty ratio. When the detection target 60 does not exist (when the second operation mode is set), the illumination unit 2 emits the light 50. When the detection target 60 exists (when the first operation mode is set), the illumination unit 2 By making it shorter than the time for irradiating the light 50, the power consumption of the illumination unit 2 can be reduced as in the second embodiment described above. As a result, the distance measurement system 70 can be reduced in power consumption. In this case, the light amount of the light 50 emitted from the illumination unit 2 in the second operation mode may or may not be reduced. Even when the amount of light 50 emitted by the illumination unit 2 is not reduced, the irradiation time in the illumination unit 2 when the second operation mode is set is longer than the irradiation time in the illumination unit 2 when the first operation mode is set. By shortening, it is possible to reduce the power consumption of the illumination unit 2 in the second operation mode.

As described above, the position detection system 1 and the distance measurement system 70 have been described in detail. However, the above description is illustrative in all aspects, and the present invention is not limited thereto. The various examples described above can be applied in combination as long as they do not contradict each other. And it is understood that the countless modification which is not illustrated can be assumed without deviating from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Optical position detection system 2 Illumination part 3 Light-receiving part 14 Light-receiving surface 21 Position detection part 22 Judgment part 23 Operation | movement control part 50 Light 60 Detection target object 70 Distance measuring system

Claims

An optical position detection system comprising:
An illumination unit that emits light;
A position detection unit that detects the position of the detection object based on an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface;
A determination unit for determining the presence or absence of the detection object based on a detection result in the position detection unit;
An operation control unit for controlling an operation mode of the optical position detection system,
The optical position detection system includes a first operation mode in which the illumination unit emits light with a first light amount, and a second operation mode in which the illumination unit emits light with a second light amount less than the first light amount. Have
The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit determines that the detection target does not exist. And an optical position detection system that sets the operation mode to the second operation mode.
The optical position detection system according to claim 1,
In the first operation mode, the position detection unit is configured to detect the x-coordinate value and the y-coordinate value indicating the position of the detection target on a coordinate plane including the light receiving surface, and the detection in a direction perpendicular to the coordinate plane. A z-coordinate value indicating the position of the object,
In the second operation mode, the position detection unit obtains only the z coordinate value of the x coordinate value, the y coordinate value, and the z coordinate value.
The optical position detection system according to claim 1,
The position detector is
In the first operation mode, as a z coordinate value indicating the position of the detection target in a direction perpendicular to the light receiving surface, a value obtained using a predetermined arithmetic expression is output as it is.
In the second operation mode, an optical position detection system that outputs a predetermined number times a value obtained using the predetermined arithmetic expression as the z coordinate value.
An optical position detection system according to any one of claims 1 to 3,
The optical position detection system in which the ratio of the irradiation time of the light in the illumination unit in the fixed time is set to be smaller in the second operation mode than in the first operation mode.
The optical position detection system according to claim 2,
In the first operation mode, the illumination unit irradiates the light at a predetermined cycle,
In the first operation mode, the position detection unit obtains at least one of the x coordinate value, the y coordinate value, and the z coordinate value at an interval longer than the predetermined period.
The optical position detection system according to claim 5,
In the first operation mode, the position detection unit obtains the x coordinate value and the y coordinate value at an interval longer than the predetermined period.
An optical position detection system according to any one of claims 5 and 6,
In the first operation mode, the position detection unit obtains the z coordinate value at an interval longer than the predetermined period.
The optical position detection system according to claim 6,
In the first operation mode, the position detection unit obtains the x coordinate value and the y coordinate value alternately, and is an optical position detection system.
The optical position detection system according to claim 8, comprising:
The optical position detection system in which the calculation circuit which calculates | requires the said x coordinate value and the said y coordinate value is common in the said position detection part.
An optical position detection system according to any one of claims 8 and 9,
The optical position detection system in which the output terminal which outputs the x coordinate value and the y coordinate value is common in the position detection unit.
An optical position detection system according to any one of claims 8 to 10,
In the first operation mode, the position detection unit obtains the x coordinate value, the y coordinate value, and the z coordinate value at intervals longer than the predetermined period,
In the first operation mode, the position detection unit alternately obtains the x coordinate value, the y coordinate value, and the z coordinate value,
The optical position detection system in which the output terminal for outputting the x coordinate value, the y coordinate value, and the z coordinate value is common in the position detection unit.
An optical position detection system comprising:
An illumination unit that emits light;
A position detection unit that detects the position of the detection object based on an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface;
A determination unit for determining the presence or absence of the detection object based on a detection result in the position detection unit;
An operation control unit for controlling an operation mode of the optical position detection system,
The optical position detection system has a first operation mode, and a second operation mode in which a ratio of the irradiation time of the light in the illumination unit in a certain time is smaller than the first operation mode,
The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit determines that the detection target does not exist. And an optical position detection system that sets the operation mode to the second operation mode.
An optical position detection system according to claim 12, comprising:
The illumination unit irradiates light at a predetermined cycle,
The optical position detection system in which the predetermined period in the illumination unit is different between the first and second operation modes.
An optical position detection system according to any one of claims 12 and 13,
The optical position detection system in which the ratio of the irradiation time of the light in the predetermined period is different between the first and second operation modes.
A control device comprising the determination unit and the operation control unit included in the optical position detection system according to any one of claims 1 to 14.
A position detection apparatus comprising the position detection unit included in the optical position detection system according to any one of claims 9 to 11.
An illumination unit that emits light; and a position detection unit that detects a position of the detection target based on an electric signal obtained by receiving the light reflected by the detection target on a light receiving surface. A control program for controlling an optical position detection system,
In the optical position detection system,
(A) a step of determining the presence or absence of the detection object based on a detection result in the position detection unit;
(B) When it is determined in step (a) that the detection target exists, the operation mode of the optical position detection system is changed to a first operation mode in which the illumination unit emits light with a first light amount. A setting process;
(C) When it is determined in step (a) that the detection target does not exist, the operation mode is the second operation mode in which the illumination is irradiated with light with a second light amount smaller than the first light amount. And a control program for executing the process set to.
An illumination unit that emits light; and a position detection unit that detects a position of the detection target based on an electric signal obtained by receiving the light reflected by the detection target on a light receiving surface. A control program for controlling an optical position detection system,
In the optical position detection system,
(A) a step of determining the presence or absence of the detection object based on a detection result in the position detection unit;
(B) When it is determined in the step (a) that the detection target is present, the operation mode of the optical position detection system is the ratio of the irradiation time of the light in the illumination unit in a certain time. Setting the first operation mode to be the first ratio;
(C) When it is determined in the step (a) that the detection target does not exist, the operation mode is set such that a ratio of the irradiation time of the light in the illumination unit in the predetermined time is the first time. A control program for executing the step of setting to the second operation mode having a second ratio smaller than the ratio.
A ranging system,
An illumination unit that emits light;
A distance detection unit that detects a distance between the ranging system and the detection object based on an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface;
A determination unit for determining the presence or absence of the detection object based on a detection result in the distance detection unit;
An operation control unit for controlling an operation mode of the ranging system;
The ranging system has a first operation mode in which the illumination unit emits light with a first light amount, and a second operation mode in which the illumination unit emits light with a second light amount less than the first light amount. And
The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit determines that the detection target does not exist. A distance measuring system that sets the operation mode to the second operation mode in the event of a failure.
The ranging system according to claim 19, wherein
The distance detector is
In the first operation mode, as a distance between the ranging system and the detection target, a value obtained using a predetermined arithmetic expression is output as it is,
In the second operation mode, the distance measuring system outputs a predetermined number of times a value obtained by using the predetermined arithmetic expression as a distance between the distance measuring system and the detection target.
A ranging system according to any one of claims 19 and 20, wherein
The distance measurement system in which the proportion of the light irradiation time in the illumination unit in the fixed time is set to be smaller in the second operation mode than in the first operation mode.
A ranging system,
An illumination unit that emits light;
A distance detection unit that detects a distance between the ranging system and the detection object based on an electrical signal obtained by receiving the light reflected by the detection object on a light receiving surface;
A determination unit for determining the presence or absence of the detection object based on a detection result in the distance detection unit;
An operation control unit for controlling an operation mode of the ranging system;
The ranging system has a first operation mode and a second operation mode in which a ratio of the irradiation time of the light in the illumination unit in a certain time is smaller than the first operation mode,
The operation control unit sets the operation mode to the first operation mode when the determination unit determines that the detection target exists, and the determination unit determines that the detection target does not exist. A distance measuring system that sets the operation mode to the second operation mode in the event of a failure.
A ranging system according to claim 22, wherein
The illumination unit irradiates light at a predetermined cycle,
The ranging system in which the predetermined period in the illumination unit is different between the first and second operation modes.
A ranging system according to any one of claims 22 and 23, wherein
Between the first and second operation modes, the distance measuring system in which the ratio of the irradiation time of the light in the predetermined period is different from each other.
A control device comprising the determination unit and the operation control unit included in the ranging system according to any one of claims 19 to 24.
An illumination unit that irradiates light, and a distance detection unit that detects a distance from the detection target based on an electrical signal obtained by receiving the light reflected by the detection target on a light receiving surface. A control program for controlling a ranging system having:
In the ranging system,
(A) a step of determining the presence or absence of the detection object based on a detection result in the distance detection unit;
(B) When it is determined in step (a) that the detection target exists, the operation mode of the ranging system is set to a first operation mode in which the illumination unit emits light with a first light amount. Process,
(C) When it is determined in step (a) that the detection target does not exist, the operation mode is the second operation mode in which the illumination is irradiated with light with a second light amount smaller than the first light amount. And a control program for executing the process set to.
An illumination unit that irradiates light, and a distance detection unit that detects a distance from the detection target based on an electrical signal obtained by receiving the light reflected by the detection target on a light receiving surface. A control program for controlling a ranging system having:
In the ranging system,
(A) a step of determining the presence or absence of the detection object based on a detection result in the distance detection unit;
(B) When it is determined in the step (a) that the detection target is present, the operation mode of the optical position detection system is the ratio of the irradiation time of the light in the illumination unit in a certain time. Setting the first operation mode to be the first ratio;
(C) When it is determined in the step (a) that the detection target does not exist, the operation mode is set such that a ratio of the irradiation time of the light in the illumination unit in the predetermined time is the first time. A control program for executing the step of setting to the second operation mode having a second ratio smaller than the ratio.