JPH04256807A - Distance sensor and cleaning apparatus utilizing distance sensor - Google Patents

Abstract

PURPOSE:To make it possible to prevent the erroneous operation of a cleaning apparatus by operating the ratio of the subtracted value to the added value of photocurrents obtained at both ends of a semiconductor-position detecting element, and detecting the position of the incident light into the semiconductor-position detecting element. CONSTITUTION:Photocurrents I1 and I2 obtained at both ends of a semiconductor position detecting element 2 are inputted into a signal processing circuit 7. In a current/ voltage converting circuit part 8 in this circuit 7, the currents I1 and I2 are converted into voltages V01 and V02. Then, in a subtracting circuit part 9, the subtraction of the voltages V01 and V02 is performed, and a subtraction output voltage VOA corresponding to the subtracted value of the currents I1 and I2 is operated. In an adding circuit part 10, the addition of the voltages V01 and V02 is performed, and an addition output voltage VOB corresponding to the added value of the currents I1 and I2 is operated. In an incident position detecting circuit part 11, the ratio of the voltage VOA to VOB is obtained, and the ratio of the subtracted value to added value of the currents I1 and I2 (I2-I1)/(I1+I2) is operated, and the incident position into the element 2 is obtained. In this way, the erroneous operation of a cleaning apparatus can be prevented.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance sensor and a cleaning device for a toilet bowl or washbasin using the distance sensor.

0002

2. Description of the Related Art Distance sensors used in conventional toilet bowl or washbasin cleaning devices are composed of a combination of an infrared light emitting diode and a photodiode.

[0003] The light emitted by the infrared light emitting diode is reflected by the user or the user's hand and enters the photodiode. Here, if the user is closer to the sensor, the amount of light incident on the photodiode will increase, and if the user is farther from the sensor, the amount of light incident on the photodiode will decrease.

[0004] From this, information on the distance to the user is obtained by detecting the magnitude of the output current of the photodiode, and if the output current is greater than a certain value, the urinal is automatically flushed.
Or make sure the tap water in the sink is running.

[0005]

[Problems to be Solved by the Invention] However, conventional distance sensors obtain distance information from the user by detecting the amount of light incident on a photodiode. The amount of light incident on the photodiode may change due to the color (reflectance) of the photodiode (background), the deterioration of the output due to aging of the infrared light emitting diode, and the cleaning device may malfunction.

For example, if the user's clothes are black, the amount of light incident on the photodiode will be reduced, making it impossible to flush the urinal automatically.

[0007] Furthermore, if the ceramic of the washstand gets wet with water, the amount of light reflected from the ceramic increases, causing the user to mistakenly judge that a hand is present, and water may remain running out.

Furthermore, as the infrared light emitting diode deteriorates over time and the amount of light emitted decreases, the amount of light incident on the photodiode will decrease even if the user or the user's hand is in a predetermined position. The toilet may not flush automatically or water may not come out from the sink.

[0009] In view of the above, the present invention provides the color of the user's clothes;
The purpose of the present invention is to provide a distance sensor that can reliably detect the distance to the user without being affected by background color, output deterioration due to changes in light emitting elements over time, etc., and prevent malfunctions of the cleaning device, and a cleaning device using the same. shall be.

0010

[Means for Solving the Problems] (1) The problem solving means according to claim 1 of the present invention includes a light emitting element 1 and a light receiving element as shown in FIGS.
A distance sensor that detects the distance to the detected object M from a position where reflected light from the detected object M enters a light receiving element, and the light receiving element has a photocurrent obtained from both ends thereof. A distance sensor consisting of a semiconductor position detection element 2 configured to be proportional to the incident position of light is provided with a signal processing circuit 7 that processes a photocurrent obtained from both ends of the semiconductor position detection element 2. calculates a subtracted output voltage corresponding to the subtracted value of the both-end photocurrent by subtracting the current-voltage conversion circuit section 8 that converts the photocurrent at both ends into voltage, and each converted voltage obtained by the current-voltage conversion circuit section 8. The subtraction circuit section 9 includes a subtraction circuit section 9 and an addition circuit section 10 that adds each converted voltage obtained by the current-voltage conversion circuit section 8 to calculate an added output voltage corresponding to the added value of the photocurrents at both ends. By taking the ratio of the subtracted output voltage obtained in , and the added output voltage obtained in the adder circuit section 10, the ratio between the subtracted value and the added value of the photocurrent at both ends is calculated, and the output voltage is applied to the semiconductor position detection element 2. It is configured to detect the position of incident light.

(2) The problem solving means according to claim 2 is provided with a light emitting element 1 and a light receiving element as shown in FIG. A distance sensor that detects the distance to an object to be detected from a position where reflected light is incident on a light receiving element, the light receiving element being configured such that a photocurrent obtained from both ends thereof is proportional to the incident position of the light. In a distance sensor consisting of a semiconductor position detection element 2, a signal processing circuit 7 is provided which processes photocurrents obtained from both ends of the semiconductor position detection element 2, and the signal processing circuit 7 calculates the logarithm of the photocurrents at both ends, and It is equipped with a logarithmic conversion circuit section 20 that converts into a voltage, and by calculating the ratio of each converted voltage obtained by the logarithmic conversion circuit section 20, the difference between the photocurrents at both ends is calculated, and the light incident on the semiconductor position detection element 2 is calculated. It detects the position.

(3) A means for solving the problem according to claim 3 is that the distance sensor according to claims 1 and 2 is attached to a urinal,
The distance between the user and the toilet bowl is detected by the distance sensor, and the toilet bowl is flushed when the user stands within a certain distance from the toilet bowl.

(4) In the problem solving means according to claim 4, the distance sensor according to claims 1 and 2 is attached to a toilet bowl having a toilet seat, and the distance between the user and the toilet seat is detected by the distance sensor, and the distance between the user and the toilet seat is detected by the distance sensor. The user's buttocks can be flushed only when the user is sitting on the toilet seat, and the toilet bowl is flushed when the user leaves the toilet seat after use.

(5) A means for solving the problem according to claim 5 is that the distance sensor according to claims 1 and 2 is attached to a washstand,
The distance sensor detects the distance between the user and the washbasin,
Cleaning water is dispensed when the user comes within a certain distance from the sink.

(6) The problem solving means according to claim 6 is the cleaning device according to claim 5, in which the cleaning water and the drying air are sequentially discharged.

(7) The problem solving means according to claim 7 is the cleaning device according to claim 5, in which soapy water, cleaning water, and drying air are sequentially discharged.

[0017]

[Operation] In the above problem solving means, the irradiated light from the light emitting element 1 is reflected by the object to be detected (user) M and enters the semiconductor position detecting element 2.

The position at which this reflected light enters the semiconductor position detecting element 2 changes depending on the distance between the detected object M and the semiconductor position detecting element 2. As the detected object M becomes farther away, the semiconductor position detecting element 2 The spot position of the incident light changes. When the position of the light incident on the semiconductor position detection element 2 changes, the balance of photocurrents obtained at both ends of the semiconductor position detection element 2 changes accordingly.

By detecting the balance between the photocurrents at both ends in the signal processing circuit 7, the incident position can be determined regardless of the incident light energy.

Therefore, malfunctions of the distance sensor due to the color of the object to be detected, the color of the background, deterioration of the output of the light emitting element, etc. are eliminated.

[0021]

[Embodiment] [First Embodiment] Fig. 1 is a principle diagram showing the distance detection operation by a distance sensor in a urinal cleaning device according to the first embodiment of the present invention, and Fig. 2 is a principle diagram showing the distance detection operation by a distance sensor used in the urinal cleaning device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view showing the configuration of a semiconductor position detection element of a distance sensor, and FIG. 3 is an electric circuit diagram of a signal processing circuit of the semiconductor position detection element.

As shown in FIG. 1, the urinal cleaning device of this embodiment has a urinal (not shown) equipped with a light emitting element 1 and a photocurrent obtained at both ends of the element so that the photocurrent is proportional to the incident position of light. semiconductor position detection device (hereinafter referred to as PSD)
n Sensitive Photo Dete
A distance sensor S equipped with a light-receiving element consisting of
The light is emitted from the user M to the user M, and the reflected light from the user M is the PSD
The distance from the user M to the user is detected from the position where water enters the urinal 2, and the urinal is flushed when the user M stands within a certain distance from the urinal.

In FIG. 1, numeral 3 is a light emitting condenser lens for condensing the irradiated light from the light emitting element 1 onto the user M, and 4 is a condenser lens for condensing the reflected light from the user M onto the PSD 2. This is a light-receiving condensing lens.

The PSD 2 is a sensor for detecting the position of a light spot using a silicon photodiode. Unlike Hijicon, CCD, etc., this is a non-divided element, so a continuous electric signal (X, Y coordinate signal) can be obtained, and it has excellent positional resolution and responsiveness.

The PSD 2 has a silicon photodiode PD and a resistor R, as shown in FIG. That is, as shown in Fig. 2, it consists of a P layer on the front surface of a flat silicon plate, an N layer on the back surface, and an I layer in the middle. In the split type, the output is divided from electrodes 5 and 6 attached to the P layer and the N layer.

When a light spot is incident on the PSD 2, an electric charge proportional to the light energy is generated at the incident position. The generated charge passes through the resistance layer (P layer in FIG. 2) as a photocurrent and is output from the electrodes 5 and 6 at both ends. Since the resistance layer (P layer) is made to have a uniform resistance value over the entire surface, the photocurrent is divided and extracted in inverse proportion to the distance to the electrodes 5 and 6.

Here, each electrode 5, 6 is connected from the center of the PSD 2.
2L is the distance from the center of PSD 2 to the incident position of the incident light, XA is the distance from the incident position to the electrode 5.
B. If the photocurrent is I0, the currents I1 and I2 taken out from the electrodes 5 and 6 are expressed by the following equations.

(When the origin is set at the center of PSD)

002
9]

[Math 1]

(When the PSD end is the origin)

0031
]

[Math 2]

Then, formulas (1) and (2) or (3) and (4)
), the ratio between the subtracted value and the added value of the currents I1 and I2 is expressed by the following formula.

(When the origin is set at the center of PSD)

003
4]

[Math 3]

(When the PSD end is the origin)

0036
]

[Math 4]

As mentioned above, since the ratio between the subtracted value and the added value of currents I1 and I2 is expressed by equations (5) and (6), PSD2
Now, the light incident position can be determined regardless of the incident light energy.

Therefore, the PSD 2 calculates the ratio of the subtracted value and the added value of the currents I1 and I2 to obtain the incident position of the reflected light from the user M, and obtains distance information from the user M.
A signal processing circuit 7 is provided that processes signal currents I1 and I2 of SD2.

As shown in FIG. 3, this signal processing circuit 7 includes a current-voltage conversion circuit section 8 that converts currents I1 and I2 into voltages Vo1 and Vo2, and a converted voltage V obtained by the current-voltage conversion circuit section 8.
o1 and Vo2 are subtracted, and the subtracted value of currents I1 and I2 (
The subtraction circuit unit 9 calculates the subtracted output voltage VoA corresponding to I2-I1), and the converted voltages Vo1 and Vo2 obtained by the current-voltage conversion circuit unit 8 are added to obtain the added value of the currents I1 and I2 (
The addition circuit section 10 calculates the addition output voltage VoB corresponding to I1+I2), the subtraction output voltage VoA obtained from the subtraction circuit section 9, and the addition output voltage VoB obtained from the addition circuit section 10 are calculated. Ratio of subtracted values of I1 and I2 (I2-I1
/I1+I2) to find the position of incidence of light incident on the PSD 2.

The current-voltage conversion circuit section 8 includes an amplifier A1 connected to one end of the resistor R of the PSD2, and an amplifier A1 connected to one end of the resistor R of the PSD2.
, an amplifier A2 connected to the other end of the resistor R, and a negative feedback resistor R1 connected to the amplifier A2. Thereby, the converted voltages Vo1 and Vo2 are expressed by the following equations.

[0041]

[Math 5]

The subtraction circuit section 9 converts the converted voltages Vo1, V
Amplifier A3 is connected to amplifiers A1 and A2 that output o2 via resistors R2, and negative feedback resistor R3 is connected to amplifier A3, resistor R2 is connected to amplifier A2, and ground. It is composed of a resistor R3. As a result, the subtracted value output voltage VoA is expressed by the following equation.

[0043]

[Math 6]

The adder circuit section 10 converts the converted voltages Vo1,
An amplifier A4 that is connected to the amplifiers A1 and A2 that output Vo2 through a resistor R4, a negative feedback resistor R5 that is connected to the amplifier A4, and an amplifier A4 that outputs the output voltage Vo3 through a resistor R6. It consists of a connected amplifier A5 and a negative feedback resistor R7 connected to the amplifier A5. As a result, the added value output voltage VoB is expressed by the following equation.

[0045]

[Math 7]

The incident position detection circuit section 11 is a microcomputer having an arithmetic function, and from the above equation, the ratio between the addition value voltage VoA and the subtraction value voltage VoB is expressed by the following equation.

[0047]

[Math. 8]

In the above cleaning device, the light emitted by the light emitting element (infrared light emitting diode) 1 is reflected by the user M and enters the PSD 2, as shown in FIG. The position where this reflected light enters the PSD 2 (light spot position) changes depending on the distance D between the user M and the distance sensor S,
When the user M gets farther from the distance sensor S (when D becomes longer), the reflected light becomes like the dashed line in Fig. 1, and the PSD2
The spot position of the incident light also changes.

When the position of the light incident on the PSD 2 changes, the balance between the signal currents I1 and I2 of the PSD 2 changes accordingly. By detecting the balance between the signal currents I1 and I2 in the signal processing circuit 7, the distance between the user M and the distance sensor S is detected, and the urinal is automatically flushed.

That is, when the signal currents I1 and I2 of the PSD 2 flow into the signal processing circuit 7, the current-voltage conversion circuit section 8
The currents I1 and I2 are converted into voltages Vo1 and Vo2. Next, the subtraction circuit unit 9 subtracts the converted voltages Vo2 and Vo1 to obtain a subtracted value output voltage VoA corresponding to the subtracted value I2-I1 of the currents I1 and I2. At the same time, the addition circuit unit 10 adds the converted voltages Vo1 and Vo2, and the current I
An added value output voltage VoB corresponding to the added value I1+I2 of 1 and I2 is obtained.

By calculating the ratio of the subtraction value output voltage VoA and the addition value output voltage VoB in the incident position detection circuit section 11, the ratio of the subtraction value and the addition value (V
Find oA/VoB=(I2-I1)/(I1+I2)).

Currents I1 and I calculated by the signal processing circuit 7
The ratio of the subtraction value and addition value of 2 (I2-I1)/(I1+I2
) is PSD2, as shown in Figure 2 and equations (5) and (6).
corresponds to the position of the light incident on (I2-I1)/
(I1+I2), regardless of the incident light energy,
The position of the light incident on the PSD 2 can be determined. P
When the position of the light incident on the SD is known, the distance between the distance sensor S and the user M can be found as described above.

In this way, the PSD2 is used as the light receiving element of the distance sensor S, and the signal currents I1 and I2 of the PSD2 are
is processed by the signal processing circuit 7 to obtain (I2-I1)/(I1
+I2), the distance sensor S and the user M determine the incident position of the light regardless of the incident light energy.
The color of the user's clothes can be detected from the distance of
Distance can be sensed without being affected by background color (reflectance) or output deterioration due to aging of infrared light emitting diodes.

[0054] Therefore, malfunctions of the cleaning device due to the above conditions can be prevented.

For example, in a urinal flushing device using a conventional distance sensor, the user is 600 meters away from the sensor.
In the case of a cleaning device designed to automatically clean when the user stands within 80 cm of the sensor, a user wearing white
When a person stands at m, white color has a high reflectance, so
I accidentally flushed it automatically. On the other hand, if a user wearing black clothes stands at a distance of 40 cm from the sensor, the black color has a low reflectance, so the device may malfunction, such as not being automatically flushed.

Using the method of this embodiment, if the sensor output is (I2-I1)/(I1+I2) when a user wearing white clothes stands 80 cm from the sensor, then the user's Even if the color of the clothes changes (for example, even if the reflectance becomes 50% of white clothes), I1→I1×0.5
, I2→I2×0.5, but the sensor output is (I
2×0.5-I1×0.5)/(I1×0.5+I2×
0.5)=(I2-I1)/(I1+I2), and the same value (same distance) as in the case of white clothes can be obtained.

In other words, if a distance sensor using PSD is used, regardless of the color of the user's clothes, etc.
To automatically flush a urinal accurately when a user stands within m.

[Second Embodiment] FIG. 4 is an electrical circuit diagram of a signal processing circuit of a semiconductor position detection element of a distance sensor used in a cleaning device according to a second embodiment of the present invention, and FIG. 5 shows an output value of the distance sensor. A diagram showing the relationship with the actual distance. FIG. 6 is a diagram showing data obtained by actually measuring the distance to the user using a semiconductor position detection element.

In this embodiment, as shown in FIG.
The light incident position is determined by calculating the ratio of the signal currents I1 and I2 of the PSD 2.

That is, the signal processing circuit 7
2, take the logarithm of the currents I1 and I2 and calculate the voltages Vo1 and Vo, respectively.
2, and the difference between the converted voltages Vo1 and Vo2 obtained by the logarithmic conversion circuit section 20 and the current I1.
, I2.

The logarithmic conversion circuit section 20 includes an amplifier A11 connected to one end of the resistor R of the PSD2, and an amplifier A1 connected to one end of the resistor R of the PSD2.
1, an amplifier A12 connected to the other end of the resistor R, and the amplifier A
12 and a logarithmic conversion diode D1 connected in negative feedback. As a result, the converted voltages Vo1, Vo2
is expressed by the following equation.

[0062]

[Math. 9]

The differential amplifier circuit section 21 converts the converted voltage Vo
1. Amplifiers A11 and A12 that output Vo2 and resistor R1
1 and the amplifier A13 connected through the amplifier A13.
and a resistor R12 connected between the resistor R11 connected to the amplifier A12 and the reference voltage Vref2. As a result, the output voltage Vo is expressed by the following equation.

[0064]

[Math. 10]

In the above configuration, when light is incident on the PSD 2, the signal currents I1 and I2 of the PSD 2 are logarithmically converted in the logarithmic conversion circuit section 20 of the signal processing circuit 7, and the voltage Vo1 is
, becomes Vo1. Next, the difference between the converted voltages Vo1 and Vo2 is processed in the differential amplifier circuit section 21, and ln(I1/I2
) is obtained.

Since I1/I2 corresponds to the position of the light incident on PSD2 regardless of the incident light energy, ln(
I1/I2), the position of the light incident on the PSD 2 can be determined.

[0067] Once the position of the light incident on the PSD 2 is known,
The distance can be determined (see Figure 5). Actually, using PSD,
Figure 6 shows the data obtained by measuring the distance to the person.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

In the above example, (I2-I1)/(I1
+I2) and I1/I2 have been described, but I1 (I1+I2), I2/(I1+I2), etc. may also be detected, or their reciprocals may be detected.

Further, in this embodiment, a distance sensor for a urinal cleaning device has been described as an example, but a distance sensor using a PSD may also be used at other locations for the purpose of detecting a user.

For example, (1) If the distance sensor of the above embodiment is attached to a toilet seat with a hot water washing function to detect whether or not a user is sitting on the toilet seat, it is possible to detect whether the user is sitting on the toilet seat or not. This prevents hot water from coming out even if you press the button by mistake, and prevents hot water from coming out and soaking the floor.

(2) The same-distance sensor is attached to a toilet bowl having a toilet seat, and the toilet bowl is configured to flush automatically when the user places his/her hand over the sensor after using the toilet.

(3) Attach the same distance sensor to the wash basin,
The sensor is configured so that when a hand is placed over the sensor, tap water, dry air, or soap water, tap water, and dry air are automatically dispensed in sequence.

[0074] Various locations can be considered for use.

[0075]

Effects of the Invention As is clear from the above description, according to the present invention, a distance sensor using a semiconductor position detection element configured so that the photocurrent obtained from both ends is proportional to the incident position of light is installed in a cleaning device. However, by measuring the distance between the distance sensor and the user, it can be used without being affected by the color of the user's clothes, the color of the background, or the deterioration of the output of the light emitting element.
This has an excellent effect of accurately detecting the presence or absence of a user and preventing malfunctions of the cleaning device.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram showing a distance detection operation by a distance sensor in a urinal cleaning device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the configuration of a semiconductor position detection element of a distance sensor used in the cleaning apparatus of this embodiment.

FIG. 3 is an electrical circuit diagram of a signal processing circuit of a semiconductor position detection element.

FIG. 4 is an electrical circuit diagram of a signal processing circuit of a semiconductor position detection element of a distance sensor used in a cleaning apparatus according to a second embodiment of the present invention.

FIG. 5 is a diagram showing the relationship between the output value of the distance sensor and the actual distance.

FIG. 6 is a diagram showing data obtained by actually measuring the distance to the user using a semiconductor position detection element.

[Explanation of symbols]

1 Light-emitting element 2 Semiconductor position detection device (PSD) 7 Signal processing circuit 8 Current-voltage conversion circuit section 9 Subtraction circuit section 10 Addition circuit section 20 Logarithmic conversion circuit section S Distance sensor M Detected object (user)

Claims (7)

[Claims] Claim 1: Comprising a light emitting element and a light receiving element, the light emitting element projects light onto a detected object, and the distance to the detected object is detected from a position where reflected light from the detected object enters the light receiving element. In the distance sensor, the light receiving element is composed of a semiconductor position detecting element configured such that a photocurrent obtained from both ends thereof is proportional to the incident position of light. A signal processing circuit that processes a current into a signal is provided, and the signal processing circuit includes a current-voltage conversion circuit unit that converts the photocurrent at both ends into a voltage, respectively;
A subtraction circuit section that subtracts each converted voltage obtained by the current-voltage conversion circuit section and calculates a subtracted output voltage corresponding to the subtracted value of the photocurrent at both ends, and a subtraction circuit section that adds each converted voltage obtained from the current-voltage conversion circuit section. an addition circuit section that calculates an addition output voltage corresponding to the addition value of the photocurrents at both ends, and calculates the ratio between the subtraction output voltage obtained by the subtraction circuit section and the addition output voltage obtained from the addition circuit section. A distance sensor characterized in that the distance sensor is configured to calculate a ratio between a subtracted value and an added value of photocurrents at both ends, and detect the position of light incident on a semiconductor position detection element. 2. A device comprising a light emitting element and a light receiving element, wherein light is emitted from the light emitting element to an object to be detected, and the distance to the object to be detected is detected from a position where reflected light from the object to be detected enters the light receiving element. In the distance sensor, the light receiving element is composed of a semiconductor position detecting element configured such that a photocurrent obtained from both ends thereof is proportional to the incident position of light. A signal processing circuit for signal processing the current is provided, and the signal processing circuit includes:
It is equipped with a logarithmic conversion circuit section that takes the logarithm of the photocurrent at both ends and converts it into a voltage, and calculates the difference between the photocurrents at both ends by taking the ratio of each converted voltage obtained by the logarithmic conversion circuit section. A distance sensor that detects the position of light incident on. 3. The distance sensor according to claims 1 and 2 is attached to a urinal, and the distance sensor detects the distance between the user and the toilet, and when the user stands within a certain distance from the toilet. A cleaning device characterized in that a urinal is flushed with water. 4. The distance sensor according to claims 1 and 2 is attached to a toilet bowl having a toilet seat, and the distance sensor detects the distance between the user and the toilet seat, and is used only when the user is sitting on the toilet seat. A cleaning device characterized in that a user's buttocks can be flushed with water, and the toilet bowl is flushed when the user leaves the toilet seat after use. 5. The distance sensor according to claim 1 or 2 is attached to a washstand, the distance sensor detects the distance between the user and the washstand, and the distance sensor detects the distance between the user and the washstand when the user comes within a certain distance range from the washstand. A cleaning device characterized in that cleaning water is sometimes dispensed. 6. The cleaning device according to claim 5, wherein the cleaning water and the drying air are sequentially discharged. 7. The cleaning device according to claim 5, wherein soapy water, cleaning water, and drying air are sequentially discharged.