JPH07225282A - Object detection apparatus - Google Patents

Abstract

PURPOSE:To provide an object detection apparatus in which an object can be detected precisely even when disturbance light is generated by any cause and whose power consumption is low. CONSTITUTION:A band-pass filter 26 uses the modulation frequency of a light- emitting instruction signal F as a central frequency, and its output signal is integrated and waveform-shaped by a waveform shaping circuit 27. As a result, even when a photodetector 6b receives disturbance light and outputs a detection signal, the detection signal is blocked by the band-pass filter 26, and no signal is input to an input port P1 for a microcomputer 22. When no signal is input to an input port P2 (in a normal state), a light-emitting element 6 emits light only once according to the light-emitting-instruction signal F at one pulse. Then, when a signal is input to the input port P2 (when a user appears or when disturbance light is generated), the light-emitting element 6 emits light continuously eight times according to the light-emitting-instruction signal F, at eight pulses, which has been modulated at a next detection timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detection device, and more specifically, it detects the presence or absence of an object by projecting light onto an object such as a human body and detecting reflected light reflected by the projected light. The present invention relates to a detecting device.

[0002]

2. Description of the Related Art Conventionally, an object detecting device for detecting an object by utilizing reflection of infrared light has been widely used in various fields of consumer and industry.

In such an object detecting device, first, infrared light is projected from a light emitting element such as a light emitting diode. When an object such as a human body exists in the space where the infrared light is projected, the projection light from the light emitting element hits the object and is reflected. The presence or absence of an object is detected by detecting the reflected light with a light receiving element such as a photodiode. That is, when the light receiving element detects the reflected light, it is determined that the object exists, and when the reflected light is not detected, it is determined that the object does not exist.

As a power source for such an object detecting device,
Commercial power or batteries are used. When a battery is used as a power source, it is general to use a battery having a long battery life, such as a lithium battery, and intermittently cause a light emitting element to emit light at a constant cycle to suppress battery consumption. As a result, the battery life is made as long as possible to reduce the labor for battery replacement.

[0005]

In the above object detecting device, infrared light generated by some external cause may act as a disturbance (hereinafter, referred to as disturbance light), and accurate object detection may not be possible. . This is because the light receiving element only outputs a detection signal when it receives infrared light of a predetermined wavelength, and the received infrared light is reflected by the projection light from the light emitting element when it hits the object. This is because it does not have a function of discriminating between the reflected light and the ambient light. Therefore, when the wavelength of the ambient light matches the wavelength of the projected light of the light emitting element, it is not possible to determine whether the object actually exists or the ambient light is generated, and the It becomes impossible to detect various objects.

For example, when an inverter fluorescent lamp is used to illuminate the installation place of the above-mentioned object detecting device, the light from the inverter fluorescent lamp may act as ambient light. That is, in the inverter fluorescent lamp, since the lighting frequency is set to a certain specified range by the inverter control, ambient light is generated in the same cycle as the lighting frequency.

The present invention has been made to solve the above problems, and an object thereof is to be able to accurately detect an object even if ambient light is generated for some reason and to have low power consumption. An object is to provide an object detection device.

[0008]

According to a first aspect of the present invention, light is periodically projected from a light emitting element at a predetermined detection timing, and reflected light reflected by an object is detected by a light receiving element. In an object detection device that detects an object, the light emitting element normally emits light for a short time, and if the light receiving element receives light at that time, the light emitting element is turned on in accordance with a pulse wave having a predetermined emission modulation frequency at the next detection timing. The main idea is to continuously emit light a plurality of times.

According to a second aspect of the present invention, the object is detected by periodically projecting light from the light emitting element at a predetermined detection timing and detecting reflected light reflected by the projected light upon the object by the light receiving element. In the object detection device, a pulse wave generation means for generating a pulse wave of a predetermined light emission modulation frequency, a light receiving detection means for detecting whether or not the light receiving element receives light, and a light emitting element for a short time to emit light during normal operation When the light reception of the light receiving element is detected, the gist is that at the next detection timing, a control means for causing the light emitting element to continuously emit light a plurality of times in accordance with the pulse wave from the pulse wave generating means.

According to a third aspect of the present invention, in the object detecting apparatus according to the first or second aspect, only the frequency component corresponding to the predetermined emission modulation frequency is filtered out of the detection signal of the light receiving element. The point is that a bandpass filter is provided.

[0011]

According to the invention described in claim 1 or claim 2, since the light emitting element normally emits light for a short time,
It is possible to reduce the power consumption required for causing the light emitting element to emit light. Further, by causing the light emitting element to emit light a plurality of times in succession according to a pulse wave of a predetermined light emission modulation frequency, disturbance light (light generated by some external cause and acting as disturbance to the reflected light of the projection light of the light emitting element) is generated. It is possible to distinguish between the case where the light receiving element receives the light and the case where the light receiving element receives the reflected light of the projection light of the light emitting element. Therefore, it is possible to accurately detect the object even if the ambient light is generated.

According to the third aspect of the invention, since only the frequency component corresponding to the emission modulation frequency of the light emitting element is filtered from the detection signal of the light receiving element, the disturbance light and the reflected light of the projection light of the light emitting element. Can be clearly distinguished.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the object detecting device of the present invention is embodied in an automatic cleaning device for a men's flush urinal (hereinafter referred to as a morning glory) will be described with reference to the drawings.

2 and 3 show the mounting state of the morning glory 1 of this embodiment. The morning glory 1 is attached to the front side of the wall surface 2 of the washroom, and the water supply pipe 3 connected to the morning glory 1 is connected with an electromagnetic opening / closing valve 4. When the electromagnetic opening / closing valve 4 is opened, washing water is supplied from the water supply pipe 3 to the morning glory 1. On the contrary, when the electromagnetic opening / closing valve 4 is closed, the morning glory 1 is discharged from the water supply pipe 3.
The supply of washing water to the machine is cut off.

The control box 5 is a wall surface 2 slightly above the morning glory 1.
Is attached to the back side of the control box 5, and the surface plate 5a of the control box 5 is attached to the wall surface 2
Is exposed to. A user detection sensor 6 including a light emitting element 6a and a light receiving element 6b is provided on the surface plate 5a, and a controller 7 and a lithium battery 8 are provided in the control box 5.

The light emitting element 6a is composed of a light emitting diode and projects infrared light having a preset wavelength. The light receiving element 6b is composed of a photodiode or a phototransistor, and outputs a detection signal only when it receives infrared light having the same wavelength as the projected light of the light emitting element 6a.

FIG. 1 shows an electric block circuit of the automatic cleaning apparatus of this embodiment. The lithium battery 8 is the controller 7
Power is supplied to the constant voltage circuit 20 and the valve drive circuit 21 therein.

The constant voltage circuit 20 is composed of a three-terminal regulator and is stable to the user detection sensor 6 and the microcomputer (hereinafter abbreviated as "microcomputer") 22, the light emission drive circuit 23, and the light reception circuit 24 in the controller 7. DC voltage is supplied.

The valve drive circuit 21 opens and closes the electromagnetic on-off valve 4 which is a self-holding solenoid valve based on a command signal from the microcomputer 22. That is, each time the valve drive circuit 21 outputs a pulsed timing signal, the electromagnetic on-off valve 4
The open / closed state is switched, and when the timing signal is not output, the previous open / closed state is maintained as it is.

The microcomputer 22 is a central processing unit (CP
U), a read-only memory (ROM) that stores a control program, a readable and writable memory (RAM) that temporarily stores a result of a user detection operation described later,
It consists of an input / output interface, etc.

Then, the microcomputer 22 generates a light emission command signal F with a predetermined duty (for example, 50%) at a predetermined modulation frequency at every predetermined detection timing (for example, 0.7 second intervals), and sends it to the light emission drive circuit 23. Output. Here, the pulse number of the light emission command signal F is normally one pulse, and as will be described later, when the user appears before the morning glory 1 or when disturbance light is generated, an appropriate pulse number (one or more pulses) (8 pulses in the embodiment). The modulation frequency of the light emission command signal F is set so as not to match the lighting frequency of the ambient light generated in the washroom. For example, when an inverter fluorescent lamp is used for illumination of a washroom, the light from the inverter fluorescent lamp becomes ambient light, and its lighting frequency is set to a certain specified range. Therefore, if the modulation frequency of the light emission command signal F is set so as to deviate from the specified range of the lighting frequency of the inverter fluorescent lamp, it will not match the lighting frequency of the ambient light.

The light emission drive circuit 23 causes the light emitting element 6a to emit light based on the light emission command signal F from the microcomputer 22.
That is, the light emission drive circuit 23 makes the light emitting element 6a emit light only once when the light emission command signal F is inputted for one pulse, and makes the light emitting element 6a emit light eight times continuously when inputted for eight pulses.

The light receiving circuit 24 comprises an amplifier 25, a bandpass filter 26 and a waveform shaping circuit 27. The amplifier 25 amplifies the detection signal of the light receiving element 6b.
The bandpass filter 26 is a bandpass filter whose center frequency is the modulation frequency of the light emission command signal F. The waveform shaping circuit 27 integrates the output signal of the bandpass filter 26 and then shapes the waveform. Therefore, even if the light receiving element 6b receives the ambient light and outputs the detection signal, if the lighting frequency of the ambient light matches the modulation frequency of the light emission command signal F, the detection signal of the light receiving element 6b is in the band. It will be blocked by the pass filter 26.

The microcomputer 22 has two input ports P1,
P2 is provided. The output signal of the amplifier 25 is directly output to the input port P2, and is also transmitted through the bandpass filter 26 and the waveform shaping circuit 27 to the input port P1.
Is output to.

Next, the operation for detecting whether or not the user is standing in front of the morning glory 1 (hereinafter, referred to as a user detecting operation) in this embodiment having the above-mentioned configuration will be described with reference to FIG.
And it demonstrates according to the time chart shown in FIG.

FIG. 4 shows a time chart when no ambient light is generated. When the user is not standing in front of the morning glory 1, the microcomputer 22 outputs the light emission command signal F one pulse at a predetermined detection timing. Along with that,
The light emission drive circuit 23 makes the light emitting element 6a emit light once. At this time, since the user is not standing in front of the morning glory 1, the projection light from the light emitting element 6a is not reflected, and the light receiving element 6b cannot detect the reflected light, and thus does not output the detection signal. Therefore, no signal is input to the input ports P1 and P2 of the microcomputer 22.

When the user appears in front of the morning glory 1 (A in the figure), when one pulse of the light emission command signal F is output, the light emitting element 6a emits light only once, and the projected light is reflected by the user. . Then, the light receiving element 6b detects the reflected light and outputs a detection signal. The detection signal is amplified by the amplifier 25 and input to the input port P2. On the other hand, no signal is input to the input port P1. Because the light emitting element 6a emits light only once, the detection signal of the light receiving element 6b also becomes one pulse, and the signal of the one pulse disappears in the process of passing through the band pass filter 26 and the waveform shaping circuit 27. is there.

When a signal is input to the input port P2, the microcomputer 22 sends a light emission command signal F at the next detection timing.
8 pulses are output (B in the figure). Then, the light emission drive circuit 23 causes the light emitting element 6a to emit light continuously eight times. The projected light of the light emitting element 6a is reflected by the user, and the light receiving element 6b detects the reflected light and outputs a detection signal. The detection signal is amplified by the amplifier 25 and directly output to the input port P2, and also output to the input port P1 via the bandpass filter 26 and the waveform shaping circuit 27. At this time, since the light emitting element 6a continuously emits light eight times, the detection signal of the light receiving element 6b also has 8 pulses. The 8-pulse signal becomes a continuous signal in the process of passing through the bandpass filter 26 and the waveform shaping circuit 27, and is output to the input port P1.

The microcomputer 22 determines that the user is not standing in front of the morning glory 1 when no signal is input to the input port P1 and determines "no user detected", and when a signal is input to the input port P1 the morning glory 1 It is determined that the user is standing in front of the “user detected”. Then, the microcomputer 22
The judgment result is stored in the RAM.

When a signal is input to the input port P1, the microcomputer 22 sends a light emission command signal F at the next detection timing.
8 pulses are output. Therefore, if the user is standing in front of the morning glory 1, the above operation is repeated. Then, the microcomputer 22 outputs eight pulses of the light emission command signal F even at the detection timing immediately before the morning glory 1 immediately after the user leaves (C in the figure). However, at this time, since the user is not standing in front of the morning glory 1, the projection light from the light emitting element 6a is not reflected, and the light receiving element 6b cannot detect the reflected light, and thus does not output the detection signal. Therefore, no signal is input to the input ports P1 and P2 of the microcomputer 22. Therefore, the microcomputer 22 determines that the user is not standing in front of the morning glory 1 and determines that "the user is not detected", and stores the determination result in the RAM.

FIG. 5 shows a time chart when ambient light is generated. When ambient light is generated at a certain detection timing (D in the figure), the light receiving element 6b detects the ambient light and outputs a detection signal as in the case of the reflected light of the projection light of the light emitting element 6a. The detection signal is amplified by the amplifier 25 and input to the input port P2. On the other hand, input port P
No signal is input to 1. Because the light emission command signal F
Since the modulation frequency of is not set to match the lighting frequency of the ambient light, the detection signal of the light receiving element 6b due to the ambient light is blocked by the bandpass filter 26 and no signal is output from the waveform shaping circuit 27. is there.

When a signal is input to the input port P2, the microcomputer 22 sends a light emission command signal F at the next detection timing.
8 pulses are output (E in the figure). Then, the light emission drive circuit 23 causes the light emitting element 6a to emit light continuously eight times. At this time, if the user is not standing in front of the morning glory 1, the projected light of the light emitting element 6a is not reflected. Therefore, even if the ambient light is generated at this time, the light receiving element 6b only detects the ambient light and does not detect the reflected light of the projection light of the light emitting element 6a, and the input port P1 is the same as in the case of D in the figure. No signal is input to.

When no signal is input to the input port P1, the microcomputer 22 determines that "user not detected". Therefore, even when such ambient light is generated, the microcomputer 22 does not erroneously determine "user detection".

As described above, according to this embodiment, even if the ambient light is generated, the user of the morning glory 1 can be accurately detected without being affected by the ambient light. Further, in this embodiment, when no signal is input to the input port P2 of the microcomputer 22 (normal time), the light emitting element 6a is caused to emit light only once in accordance with the emission command signal F of one pulse at each detection timing. When a signal is input to the input port P2 of the microcomputer 22 (when the user appears before the morning glory 1 or when ambient light is generated), 8 pulses of modulated pulse are applied at the next detection timing. The light emitting element 6a is caused to emit light eight times in succession in accordance with the light emission command signal F.

Therefore, the power consumption of the controller 7 can be reduced during normal operation. By the way, even in frequently used washrooms such as public toilets at stations, 24 hours a day
Of the time, the morning glory 1 is usually used for 2 hours or less. Therefore, if the power consumption during normal operation is reduced, the consumption of the lithium battery 8 can be greatly suppressed. As a result, the battery life of the lithium battery 8 is lengthened, and the labor for battery replacement is reduced.

By the way, the microcomputer 22 performs the above-mentioned user detection operation at a predetermined detection timing. And
Next to the judgment result of "user not detected", "user detected"
If the determination result is that the microcomputer 22 performs the pre-washing process for the morning glory 1. That is, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic opening / closing valve 4 for a certain period of time to supply a certain amount of washing water from the water supply pipe 3 to the morning glory 1 to wash the morning glory 1. As a result, the user can comfortably add small amounts and the morning glory 1 is less likely to get dirty.

Subsequently, when the judgment result of "user detection" is followed by the judgment result of "user non-detection", the microcomputer 22 indicates that the user, who has finished adding small amounts, leaves from the front of the morning glory 1. After the judgment, the morning glory 1 is subjected to the post-cleaning process. That is, the microcomputer 22 controls the valve drive circuit 21 to open the electromagnetic on-off valve 4 for a certain period of time to supply a certain amount of cleaning water from the water supply pipe 3 to the morning glory 1 and to clean it by the user's small use. Washed morning glory 1

As described above, in the automatic washing device for morning glory 1 according to the present embodiment, when the user who wants to take a small dose stands in front of the morning glory 1, the morning glory 1 is washed (pre-cleaning process), and the small amount is washed. When the user who has finished adding leaves the front of the morning glory 1 again, the morning glory 1 is washed again (post-cleaning processing). Therefore, the morning glory 1 can be kept clean at any time.

The above embodiment may be modified as follows. 1) In the above-mentioned embodiment, it is judged that the user is detected only by inputting the signal to the input port P1 once.
When the signal 1 is continuously input a predetermined number of times (for example, 2 to 3 times), it is determined as "user detection".

2) Even in the normal state, the light emitting element 6a is continuously operated a plurality of times (8 times or less in the above embodiment, for example, 2 to 3 times) in accordance with the modulated light emission command signal F of a plurality of pulses at each detection timing. Light up.

3) A waveform shaping circuit is also provided between the amplifier 25 and the input port P2 of the microcomputer 22. 4) The pre-cleaning process is performed when the determination result of “user detection” is repeated a plurality of times (for example, twice) after the determination result of “user non-detection”. In addition, the post-cleaning process is performed when the determination result of "user non-detection" follows the determination result of "user detection" a plurality of times (for example, twice). In this case, even if a person simply crosses the front of the morning glory 1 or if the user's body shakes during small use, the user detection operation can be performed more reliably, and the pre-cleaning process and the post-cleaning process can be performed. It will not be done by mistake.

5) Replace the lithium battery 8 with a DC power supply and supply power from a commercial power supply. 6) The constant voltage circuit 20 is omitted.

7) The constant voltage circuit 20 is also connected to the valve drive circuit 21.
A stabilized DC voltage is supplied. 8) Use visible light or ultraviolet light instead of infrared light. That is, visible light or ultraviolet light is projected from the light emitting element 6a instead of infrared light, and the light receiving element 6b receives the projected light to output a detection signal.

9) It is embodied not only in the morning glory 1 but also in an automatic cleaning device for various sanitary appliances such as a wash basin. 10) Not only the automatic cleaning device for sanitary equipment but also other object detection devices such as automatic doors and FA devices.

[0045]

As described above in detail, according to the present invention, it is possible to provide an object detecting device which can detect an object accurately even if ambient light is generated for some reason and which consumes less power. It has an excellent effect that it can be done.

[Brief description of drawings]

FIG. 1 is an electric block circuit diagram of an embodiment in which the present invention is embodied in an automatic washing device for a flush urinal for men (morning glory).

FIG. 2 is a partially cutaway side view showing an attached state of the flush urinal for men (morning glory) of the embodiment.

3 is a front view of the flush urinal for men (morning glory) shown in FIG. 2. FIG.

FIG. 4 is a time chart for explaining the operation of the embodiment.

FIG. 5 is a time chart for explaining the operation of the embodiment.

[Explanation of symbols]

6a ... Light emitting element, 6b ... Light receiving element, 22 ... Microcomputer as pulse wave generating means and light receiving detecting means, 23 ... Light emission drive circuit as pulse wave generating means, 2
4 ... Light receiving circuit as light receiving detecting means, 27 ... Band pass filter

Claims (3)

[Claims] 1. An object for detecting an object by periodically projecting light from a light emitting element (6a) at a predetermined detection timing, and detecting reflected light reflected by the projected light upon the object by a light receiving element (6b). In the detection device, the light emitting element normally emits light for a short time, and if the light receiving element receives light at that time, at the next detection timing, the light emitting element continuously emits light a plurality of times in accordance with a pulse wave of a predetermined emission modulation frequency. An object detection device characterized by the above. 2. An object which detects an object by periodically projecting light from a light emitting element (6a) at a predetermined detection timing and detecting reflected light reflected by the projected light upon the object by a light receiving element (6b). In the detection device, pulse wave generation means (22, 23) for generating a pulse wave of a predetermined emission modulation frequency, and light reception detection means (24, 23) for detecting the presence or absence of light reception by the light receiving element
22), the light emitting element normally emits light for a short time, and if the light receiving element detects that the light receiving element has received light, the light emitting element is continuously operated a plurality of times in accordance with the pulse wave from the pulse wave generating means at the next detection timing. And a control means (22) for emitting light to provide an object detection device. 3. The object detection device according to claim 1, further comprising a bandpass filter (26) for filtering only a frequency component corresponding to the predetermined emission modulation frequency in the detection signal of the light receiving element. An object detection device characterized by being provided.