JP2013213680A - Object detecting device, object detecting method, object detecting program, and information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an object detecting device capable of accurately detecting presence/absence of a detection object even under a situation where intensity of external light other than reflected light as infrared light is changing.SOLUTION: A proximity sensor S includes: a light-emitting unit 1 for emitting infrared light IR; a light-receiving unit 2 for receiving reflected light R obtained by reflecting the infrared light IR on a hand H; and an illuminance sensor 3 for detecting an illuminance of light with a wavelength other than the infrared light IR. The proximity sensor further includes: a sensor driver 10 that changes a threshold level for detecting presence/absence of light reception of the reflected light R, on the basis of the illuminance detected by the illuminance sensor 3; and a CPU 11 that, when receiving the reflected light R with a level higher than the changed threshold, determines that the hand H is present.

Description

  The present application belongs to the technical field of an object detection device, an object detection method, an object detection program, and an information recording medium. More specifically, an object detection device and an object detection method that include a light emitting unit and a light receiving unit to detect an object as a detection target, a program for the object detection device, and an information recording medium technology on which the program is recorded Belonging to the field.

  For example, when operating an in-vehicle device mounted on a vehicle, the movement of a human hand is detected by a so-called proximity sensor such as an infrared sensor in consideration of the fact that the interior of the vehicle is not wide and driving safety, etc. In-vehicle devices are controlled according to the contents. In this case, examples of the in-vehicle device include a navigation device and an audio device.

  On the other hand, as an example of the configuration of the conventional proximity sensor, infrared light is emitted from the light emitting unit, and the reflected light reflected by the human hand is received by the light receiving unit. Some devices are configured to detect the presence or absence.

  On the other hand, in the case of a vehicle equipped with an in-vehicle device, the light receiving unit provided in the in-vehicle device is not limited to reflected light from a human hand, or other light such as sunlight or light from a bright streetlight. Light may enter. In this case, depending on the level of incident external light, it may be determined that there is a human hand despite the absence of the human hand due to the incident of the external light on the light receiving unit. In this case, there is a problem that the in-vehicle device malfunctions.

  Therefore, as a technique for solving this problem, a technique described in Patent Document 1 below has been developed. In the technique described in Patent Document 1, the level of the external light is detected by an illuminance sensor provided separately from the light receiving unit, and the detected external light level is equal to or higher than a predetermined illuminance threshold. Is configured to turn off the function of the proximity sensor itself. Further, as a conventional technique for a proximity sensor using infrared light, there is one disclosed in Patent Document 2 below. This Patent Document 2 describes a proximity sensor that eliminates the influence of ambient illuminance by setting the difference between the ambient illuminance signal and the received light signal as a detection target.

JP 2010-199706 A (FIG. 2, FIG. 13A, FIG. 13B, etc.) JP 2010-127635 A (FIG. 3 etc.)

  However, in the technique described in Patent Document 1, the proximity sensor itself does not function when the level of external light is equal to or greater than the illuminance threshold. For example, when strong sunlight is inserted into the vehicle. However, the proximity sensor does not function, and as a result, the in-vehicle device cannot be operated. On the other hand, the situation in which sunlight is inserted as described above is a situation that can frequently occur during operation of a vehicle on a sunny day, for example, and it is inconvenient that the in-vehicle device cannot be operated in such a case. There is also a possibility of problems in safe operation.

  Further, in the technique described in Patent Document 2, when the ambient illuminance increases, the ambient illuminance signal and the light reception signal become the same level and cannot be distinguished from each other, and as a result, the light reception signal is not detected. This invites the same problem as in the above-mentioned Patent Document 1.

  Therefore, the present application has been made in view of the above problems, and an example of the problem is that the presence or absence of a detection target is accurately determined even in a situation where the intensity of external light other than reflected light that is infrared light changes. It is an object of the present invention to provide an object detection apparatus and an object detection method that can be determined in a short time, a program for the object detection apparatus, and an information recording medium on which the program is recorded.

  In order to solve the above problems, the invention described in claim 1 includes a light emitting unit that emits infrared light, and a light receiving unit that receives reflected light reflected by the detected infrared light on a detection target. Illuminance detection means for detecting the illuminance of light of a wavelength other than the infrared light, and a threshold level for detecting whether or not the reflected light is received in the light receiving unit, the illuminance detection Change means for changing based on the illuminance detected by the means, and determination means for determining that there is the detection object when the reflected light having a level higher than the changed threshold level is received. .

  In order to solve the above-mentioned problem, the invention according to claim 5 includes: a light emitting unit that emits infrared light; and a light receiving unit that receives reflected light reflected by the detected infrared light on the detection target. Illuminance detecting means for detecting illuminance of light of a wavelength other than the infrared light, and an object detection method executed in an object detection device for detecting whether the reflected light is received by the light receiving unit. A change step of changing a threshold level based on the illuminance detected by the illuminance detection means, and when the reflected light of a level higher than the changed threshold level is received, it is determined that there is the detection target Determining step.

  In order to solve the above-described problems, the invention described in claim 6 includes: a light emitting unit that emits infrared light; and a light receiving unit that receives reflected light reflected by the detected infrared light on the detection target. An illuminance detecting means for detecting the illuminance of light of a wavelength other than the infrared light, and a threshold level for detecting in the light receiving unit whether or not the reflected light is received. A change unit that changes based on the illuminance detected by the illuminance detection unit, and a determination that the detected object is present when the reflected light having a level higher than the changed threshold level is received. Function as a means.

  In order to solve the above-mentioned problem, in the invention described in claim 7, the object detection program described in claim 6 is recorded so as to be readable by the computer described in claim 6.

It is a block diagram which shows the schematic structure of the object detection apparatus which concerns on embodiment. It is a block diagram etc. which show schematic structure of the proximity sensor which concerns on an Example, (a) is the said block diagram, (b) is a figure which illustrates a detection range. It is a figure explaining the detection process which concerns on an Example. It is a flowchart which shows the detection process which concerns on an Example. It is a figure which illustrates the change of the drive current of the light emission part in the detection process which concerns on an Example.

  Next, the form for implementing this application is demonstrated using FIG. FIG. 1 is a block diagram showing a schematic configuration of the object detection apparatus according to the embodiment.

  As shown in FIG. 1, the object detection device S according to the embodiment receives a light emitting unit 1 that emits infrared light IR, and reflected light R that is reflected from the detection target H by the emitted infrared light IR. An object detection device S including a light receiving unit 2 and an illuminance detection unit 3 that detects the illuminance of light having a wavelength other than infrared light IR. In addition to the light emitting unit 1, the light receiving unit 2, and the illuminance detection unit 3 The change means 10 and the determination means 11 are configured. The light having a wavelength other than the infrared light IR at this time is, for example, visible light or ultraviolet light in sunlight.

  In this configuration, the changing unit 10 changes the threshold level for detecting whether the reflected light R is received by the light receiving unit 2 based on the illuminance detected by the illuminance detecting unit 3.

  Accordingly, the determination unit 11 determines that there is the detection target H when the reflected light R having a level higher than the changed threshold level is received.

  As described above, according to the processing of the object detection device S according to the embodiment, the threshold level for detecting whether or not the reflected light R is received is determined based on the illuminance of light having a wavelength other than the infrared light IR. When the reflected light R having a level higher than the changed threshold level is received, it is determined that there is the detection target H. Therefore, the presence / absence of the detection target H can be accurately determined even under a situation where the intensity of light other than the reflected light R changes.

  Next, specific examples corresponding to the above-described embodiment will be described with reference to FIGS. In addition, the Example demonstrated below is an Example at the time of applying embodiment with respect to the proximity sensor which detects presence of the human hand as the detection target H using infrared light.

  FIG. 2 is a block diagram illustrating a schematic configuration of the proximity sensor according to the embodiment, and FIG. 3 is a diagram illustrating a detection process according to the embodiment. FIG. 4 is a flowchart illustrating the detection process according to the embodiment, and FIG. 5 is a diagram illustrating a change in the drive current of the light emitting unit in the detection process according to the embodiment. At this time, in FIG. 2, the same member numbers as the respective constituent members in the object detection apparatus S are used for the respective constituent members in the examples corresponding to the respective constituent members in the object detection apparatus S according to the embodiment shown in FIG. 1. ing.

  As illustrated in FIG. 2A, the proximity sensor S according to the embodiment is a proximity sensor that detects a human hand H as the detection target H by infrared light IR. Specifically, the proximity sensor S according to the embodiment includes a light emitting unit 1 that emits infrared light IR for detection, and reflected light R (which goes without saying) that the infrared light IR emitted from the light emitting unit 1 is reflected by the hand H. The light receiving unit 2 that receives the infrared light), the illuminance sensor 3 that detects the illuminance of visible light around the proximity sensor S, and the light emitting unit 1 and the light receiving unit 2 are driven and detected by the illuminance sensor 3. Corresponding to the detection result of the presence / absence of the hand H as the proximity sensor S according to the sensor driver 10 that performs the process of setting the infrared threshold level according to the later-described example based on the illuminance of the visible light that has been performed For example, it is composed of a CPU 11 that outputs a predetermined command. At this time, the sensor driver 10 corresponds to an example of the changing unit 10 according to the embodiment and an example of the “light emitting unit driving unit” according to the present application, and the CPU 11 corresponds to an example of the determination unit 11 according to the embodiment.

  In this configuration, the light emitting unit 1, the light receiving unit 2, and the illuminance sensor 3 are specifically disposed on a planar base B as shown in FIG. With this arrangement, the light emitting unit 1 and the light receiving unit 2 form a detection area A as the proximity sensor S. Further, it is desirable that the illuminance sensor 3 is arranged as close as possible to the light emitting unit 1 or the light receiving unit 2 in order to improve the accuracy of detecting the illuminance of visible light according to the embodiment. Then, the sensor driver 10 emits infrared IR from the light emitting unit 1 through processing to be described later, and causes the light receiving unit 2 to receive the reflected light R reflected by the hand H. Thereby, it is detected whether or not the hand H to be detected exists in the detection area A as infrared light. Specifically, the sensor driver 10 detects the presence of the hand H in the detection region A when it is detected that the reflected light R having a level equal to or higher than an infrared threshold level described later is received in the light receiving unit 2. Is output to the CPU 11. Thereby, the CPU 11 outputs, for example, a command corresponding to the detected hand H based on the detection signal.

  Next, the detection process in the proximity sensor S according to the embodiment will be specifically described with reference to FIGS.

  First, the outline of the infrared threshold level according to the embodiment will be described with reference to FIG.

  As described above, the sensor driver 10 detects when the light receiving unit 2 detects that the reflected light R having a level equal to or higher than the infrared threshold level set in the sensor driver 10 at that time is received. A detection signal indicating that the presence of the hand H is detected in the area A is output to the CPU 11. At this time, as illustrated in FIG. 3, the infrared threshold level IRTH according to the embodiment is a visible value detected by the illuminance sensor 3 at that time from among a plurality of preset infrared threshold levels IRTH1 to IRTH3. One infrared threshold level IRTH is set based on the illuminance of light, and is used for detecting the hand H.

  At this time, as illustrated in FIG. 3, the first infrared threshold level IRTH1 is an infrared threshold level that is set when the illuminance sensor 3 does not detect the illuminance of visible light, and is determined similarly to the conventional proximity sensor. Is the infrared threshold level determined by. On the other hand, the second infrared threshold level IRTH2 is replaced with the first infrared threshold level IRTH1 when the illuminance of visible light detected by the illuminance sensor 3 becomes, for example, the first illuminance threshold level VTH1 illustrated in FIG. Infrared threshold level to be set. Further, the third infrared threshold level IRTH3 is the first infrared threshold level IRTH1 when the illuminance of visible light detected by the illuminance sensor 3 is increased to, for example, the second illuminance threshold level VTH2 illustrated in FIG. This is an infrared threshold level set in place of the second infrared threshold level IRTH2. Note that data indicating each infrared threshold level IRTH is stored in advance in a non-volatile manner such as a ROM (not shown) of the CPU 11, for example, and is read and used by the sensor driver 10 as necessary.

  As described above, the sensor driver 10 according to the embodiment detects the reflected light R while sequentially switching and setting the infrared threshold level IRTH based on the illuminance of visible light detected by the illuminance sensor 3, and the detection signal is detected. It outputs to CPU11. The relationship between the first illuminance threshold level VTH1 and the second infrared threshold level IRTH2 (that is, what value is the second infrared threshold level IRTH2 relative to the first illuminance threshold level VTH1), and the first Regarding the relationship between the 2 illuminance threshold level VTH2 and the third infrared threshold level IRTH3 (ie, what value the third infrared threshold level IRTH3 is relative to the second illuminance threshold level VTH2), for example, Preliminarily set experimentally or empirically based on the normal light emission intensity in the light emitting unit 1, the sensitivity as the light receiving unit 2, or the environment around the position of the vehicle interior where the proximity sensor S is installed. However, it may be configured such that a user such as a driver can freely change based on an operation by an operation unit (not shown), for example.

  Next, the detection process in the proximity sensor S according to the embodiment including the sensor driver 10 will be specifically described with reference to FIG.

  As shown in FIG. 4, first, the sensor driver 10 monitors whether or not the power of the proximity sensor S is turned on (step S1). If the power is not turned on in the monitoring in step S1 (step S1; NO), the sensor driver 10 continues the monitoring as it is. On the other hand, when the power is turned on in the monitoring of step S1 (step S1; YES), the sensor driver 10 drives the light emitting unit 1 and the light receiving unit 2, and further starts detecting the illuminance of surrounding visible light by the illuminance sensor 3. (Step S2).

  Next, the sensor driver 10 sets the first infrared threshold level IRTH1 as the infrared threshold level IRTH when detecting whether or not the reflected light R is received by the light receiving unit 2, and then emits light from the light emitting unit 1. Wait (step S3).

  Next, the sensor driver 10 determines whether or not the illuminance of visible light detected by the illuminance sensor 3 is equal to or lower than the first illuminance threshold level VTH1 (step S4). When the illuminance of visible light at that time is not less than or equal to the first illuminance threshold level VTH1 in the determination of step S4 (step S4; NO), the sensor driver 10 proceeds to the process of step S10 described later. On the other hand, when the illuminance of visible light at that time is equal to or lower than the first illuminance threshold level VTH1 in the determination in step S4 (step S4; YES), the sensor driver 10 next drives the light emission unit 1 for driving current. (I.e., light emission power; the same applies hereinafter) to a value similar to the conventional value, i.e., the value of the drive current used when detecting the presence of the hand H when no external light is received by the light receiving unit 2. In step S5, the light emitting unit 1 is caused to emit light using the drive current having the set value (step S6). Note that the value of the drive current set at this time is also the initial value of the drive current according to the embodiment. Accordingly, the sensor driver 10 receives the reflected light R corresponding to the light emission of the light emitting unit 1 and detects the received light level. Then, the sensor driver 10 determines whether or not the received light level is equal to or higher than the first infrared threshold level IRTH1 (step S7). If the light reception level does not exceed the first infrared threshold level IRTH1 in the determination in step S7 (step S7; NO), the sensor driver 10 returns to step S3 and repeats the processing described above. On the other hand, if the light reception level exceeds the first infrared threshold level IRTH1 in the determination in step S7 (step S7; YES), the sensor driver 10 outputs that fact to the CPU 11. As a result, the CPU 11 determines that the hand H exists in the detection range A (step S8), and performs processing such as outputting a predetermined command associated with the presence of the hand H in advance. Do. Thereafter, the sensor driver 10 determines whether or not the power of the proximity sensor S1 is turned off (step S9). If the power is not turned off in the determination in step S9 (step S9; NO), the sensor driver 10 proceeds to the process in step S3. On the other hand, when the power is turned off in the determination in step S9 (step S9; YES), the sensor driver 10 and the CPU 11 end the detection process according to the embodiment.

  On the other hand, if the illuminance of visible light at that time is not less than or equal to the first illuminance threshold level VTH1 in the determination of step S4 (step S4; NO), the sensor driver 10 next detects visible light detected by the illuminance sensor 3. It is determined whether or not the illuminance is equal to or lower than the second illuminance threshold level VTH2 (step S10). When the illuminance of visible light at that time is not less than or equal to the second illuminance threshold level VTH2 in the determination of step S10 (step S10; NO), the sensor driver 10 proceeds to the process of step S14 described later. On the other hand, when the illuminance of visible light at that time is equal to or lower than the second illuminance threshold level VTH2 in the determination in step S10 (step S10; YES), the sensor driver 10 next performs the above-described first as the infrared threshold level IRTH. After setting the 2 infrared threshold level IRTH2, the light emission power in the light emitting unit 1 is set to a value corresponding to the second infrared threshold level IRTH2 (step S11), and the light emitting unit 1 is further set by the light emission power of the set value. Is caused to emit light (step S12).

Here, when the second infrared threshold level IRTH2 or the third infrared threshold level IRTH3 is set in the sensor driver 10, the sensor driver 10 according to the embodiment sets the second infrared threshold level set. Corresponding to the level IRTH2 or the third infrared threshold level IRTH3, the intensity of the infrared light IR in the light emitting unit 1 is increased as compared with the case where the first infrared threshold level IRTH1 is set in the sensor driver 10. This is because the infrared threshold level IRTH used for detecting the presence or absence of the hand H increases from the first infrared threshold level IRTH1 to the second infrared threshold level IRTH2 or the third infrared threshold level IRTH3. If the stronger reflected light R is not received, it is not detected that the hand H is present. Therefore, if the light emission level of the light emitting unit 1 is equal to that at the first infrared threshold level IRTH1, the position to be originally detected This is because if the hand H is not present at a closer position, it will not be detected. Specifically, the sensor driver 10 sets the distance from the proximity sensor S where the presence of the hand H is detected to be constant before and after the change of the infrared threshold level IRTH, for example, from the first infrared threshold level IRTH1 to the second. The intensity of the infrared light IR corresponding to the mode of change to the infrared threshold level IRTH2, or the mode of change from the first infrared threshold level IRTH1 or the second infrared threshold level IRTH2 to the third infrared threshold level IRTH3 The drive current value of the light emitting unit 1 is set so that the Note in Figure 5, an example of a change in the drive current I _L in the actual light emitting portion 1, the wavelength of the infrared light IR 890 nm, temperature 25 ° C., are shown for the case of the driving voltage 5V. 5, for example at the level of the drive current I _L corresponding to the first infrared threshold level IRTH1 is level illustrated by a dotted line, when the second infrared threshold level IRTH2 is set in the sensor driver 10 increases the drive current I _L to a level illustrated by a dashed line (see the upward arrows in Fig. 5) is illustrated. In FIG. 5, the received light level of the infrared light in the external light including the visible light whose illuminance is detected by the illuminance sensor 3 is illustrated by a broken line with an error width (flicker width) of about 20 μA.

  Next, the sensor driver 10 receives the reflected light R corresponding to the light emission of the light emitting unit 1 by the light emission of the light emitting unit 1 in step S12 and detects the light reception level. Thereby, the sensor driver 10 determines whether or not the light reception level is equal to or higher than the second infrared threshold level IRTH2 (step S13). When the light reception level does not exceed the second infrared threshold level IRTH2 in the determination in step S13 (step S13; NO), the sensor driver 10 returns the value of the drive current of the light emitting unit 1 to the initial value (step S17). Thereafter, the process returns to step S3 and the above-described processing is repeated. On the other hand, when the light receiving level exceeds the second infrared threshold level IRTH2 in the determination in step S13 (step S13; YES), the sensor driver 10 outputs the fact to the CPU 11 and sets the value of the driving current of the light emitting unit 1 to the initial value. The value is returned (step S18). As a result, the CPU 11 and the sensor driver 10 shift to the operations in steps S8 and S9.

  Further, when the illuminance of visible light at that time is not less than or equal to the second illuminance threshold level VTH2 in the determination in step S10 (step S10; NO), the intensity of external light including visible light is higher. Therefore, the sensor driver 10 next sets the third infrared threshold level IRTH3 as the infrared threshold level IRTH, and then sets the light emission power in the light emitting unit 1 to a value corresponding to the third infrared threshold level IRTH3. (Step S14) Further, the light emitting unit 1 is caused to emit light with the light emission power of the set value (Step S15). Accordingly, the sensor driver 10 receives the reflected light R corresponding to the light emission of the light emitting unit 1 and detects the received light level. Then, the sensor driver 10 determines whether or not the received light level is equal to or higher than the third infrared threshold level IRTH3 (step S16). When the light reception level does not exceed the third infrared threshold level IRTH3 in the determination of step S16 (step S16; NO), the sensor driver 10 returns to step S3 through the initial value setting process according to step 17 and is described above. Repeat the process. On the other hand, if the light reception level exceeds the third infrared threshold level IRTH3 in the determination in step S16 (step S16; YES), the sensor driver 10 outputs the fact to the CPU 11 and sets the value of the drive current of the light emitting unit 1 to the initial value. The value is returned (step S18). As a result, the CPU 11 and the sensor driver 10 shift to the operations in steps S8 and S9.

  Through the series of detection processes according to the embodiment described above, the infrared threshold level IRTH used for detecting the reflected light R is changed to the illuminance of visible light around the proximity sensor S as illustrated by the solid line in the lower part of FIG. Based on this, it is set by sequentially switching. Then, when the light reception level of the reflected light R is equal to or higher than the infrared threshold level IRTH set at that time as illustrated in FIG. 3, it is determined that the hand H exists in the detection range A. Even when the illuminance of visible light exceeds the second illuminance threshold level VTH2 and fluctuates as illustrated in FIG. 3, the infrared threshold level IRTH at that time is high as the third infrared threshold level IRTH3. Therefore, the presence of the hand H can be detected stably without being affected by this fluctuation.

  As described above, according to the detection processing according to the embodiment, the infrared threshold level IRTH for detecting whether or not the reflected light R is received is changed based on the illuminance of visible light, and the changed infrared light Since it is determined that the hand H is present when the reflected light R having a level higher than the threshold level IRTH is received, the presence / absence of the hand H can be accurately determined even under a situation where the intensity of external light other than the reflected light R changes. Can do.

  In addition, since the infrared threshold level IRTH for determining whether or not the reflected light R, which is infrared light, is received is changed based on the illuminance of visible light, the infrared threshold level IRTH is determined based on the illuminance of light of a nearby wavelength. Is changed, the presence / absence of the hand H can be more accurately determined.

  Furthermore, since the infrared threshold level IRTH is changed to be higher as the illuminance of visible light is higher, the presence / absence of the hand H can be accurately determined even under a situation where the intensity of external light other than the reflected light R is high.

  Furthermore, since the light emitting unit 1 emits light by changing the light emission level of the infrared light IR in a mode corresponding to the mode of changing the infrared threshold level IRTH, detection is performed regardless of the intensity of external light other than the infrared light IR. The possible distance can be constant.

  In the above-described embodiment and example, the case where the detection process shown in the flowchart of FIG. 4 is executed by the sensor driver 10 has been described. However, the CPU 11 may be configured to execute the detection process. it can. In this case, the illuminance sensor 3 may be connected to the CPU 11 instead of the sensor driver 10.

In the embodiments and examples described above, a configuration also changes the value of the infrared threshold level IRTH of the drive signal I _L corresponding to the change value, it is changed value of the infrared threshold level IRTH drive It may be a constant value of the signal I _L.

  Furthermore, in the above-described embodiments and examples, the illuminance sensor 3 detects the illuminance of visible light around the proximity sensor S. However, in addition to this, light having a wavelength other than infrared light, for example, ultraviolet light is used. The illuminance can be detected by an illuminance sensor, and the infrared threshold level can be changed based on the detected illuminance.

  Furthermore, although the case where the detection target H is a human hand H has been described, the detection target H is not limited to the hand H, and any object that can reflect infrared light IR can be detected. Its presence in range A can be determined.

  Furthermore, the detection processing according to the above-described embodiments and examples can be similarly executed in a proximity sensor including a light emitting unit driven by a pulsed drive current.

  In the above-described embodiments and examples, the case where the present application is applied to the proximity sensor S for controlling the vehicle-mounted device has been described. However, in addition to this, on / off of general household lighting and brightness are controlled. The present application can also be applied to detection of the presence of the hand H by a non-contact type switch such as an infrared type for control. In this case, the presence or absence of the hand H can be detected with the infrared threshold level changed based on the illuminance of visible light included in the external light entering the room with the illumination.

  Furthermore, a program corresponding to the flowchart shown in FIG. 4 is recorded on a recording medium such as a flexible disk or a hard disk, or obtained via a network such as the Internet, and read out to a general-purpose microcomputer or the like. It is possible to cause the microcomputer or the like to function as the sensor driver 10 and the CPU 11 according to the embodiment.

DESCRIPTION OF SYMBOLS 1 Light emission part 2 Light reception part 3 Illuminance detection means (illuminance sensor)
10 Changing means (sensor driver)
11. Determination means (CPU)
H Detection object (hand)
S Object detection device (proximity sensor)
A Detection area

Claims (7)

A light emitting unit that emits infrared light, a light receiving unit that receives reflected light of the emitted infrared light reflected by a detection target, and an illuminance detection unit that detects the illuminance of light having a wavelength other than the infrared light In an object detection device comprising:
Changing means for changing a threshold level for detecting whether or not the reflected light is received in the light receiving unit based on the illuminance detected by the illuminance detecting means;
Determination means for determining that the detection object is present when the reflected light of a level higher than the changed threshold level is received;
An object detection apparatus comprising: The object detection apparatus according to claim 1,
The object detection apparatus according to claim 1, wherein the light having a wavelength other than the infrared light is visible light. In the object detection device according to claim 1 or 2,
The object detecting device, wherein the changing means changes the threshold level so that the threshold level becomes higher as the illuminance detected by the illuminance detecting means is higher. In the object detection device according to any one of claims 1 to 3,
An object detection apparatus comprising: a light emitting unit driving unit configured to change the emission power of the infrared light in the light emitting unit in a mode corresponding to the mode of changing the threshold level to cause the light emitting unit to emit light. A light emitting unit that emits infrared light, a light receiving unit that receives reflected light of the emitted infrared light reflected by a detection target, and an illuminance detection unit that detects the illuminance of light having a wavelength other than the infrared light In an object detection method executed in an object detection device comprising:
A change step of changing a threshold level for detecting whether or not the reflected light is received in the light receiving unit based on the illuminance detected by the illuminance detecting means;
A determination step of determining that the detection target is present when the reflected light of a level higher than the changed threshold level is received;
An object detection method comprising: A light emitting unit that emits infrared light, a light receiving unit that receives reflected light of the emitted infrared light reflected by a detection target, and an illuminance detection unit that detects the illuminance of light having a wavelength other than the infrared light A computer included in the object detection device comprising:
Changing means for changing a threshold level for detecting whether or not the reflected light is received in the light receiving unit based on the illuminance detected by the illuminance detecting means, and
Determining means for determining that the detection object is present when the reflected light of a level higher than the changed threshold level is received;
An object detection program that functions as a computer program.   An information recording medium in which the object detection program according to claim 6 is recorded so as to be readable by the computer according to claim 6.