JPH07209435A - Sanitary device using distance sensor - Google Patents

Abstract

PURPOSE:To provide a sanitary device having a distance sensor in which the step width can be uniformly set even with a far or near detection setting distance when the distance with a human body is measured. CONSTITUTION:In a sanitary device having a distance sensor having a light emitting element 2 for projecting a light synchronously with intermittent light projecting timing, a semiconductor position detecting element 1 to which a photoelectric current is carried proportionally in conformation of the incident position of the light, current/voltage converting circuits 11, 12 for converting the respective photoelectric currents of the semiconductor position detecting element 1 to voltage, integrating circuit 13, 14 for averaging the voltages from the current/voltage converting circuits 11, 12, and a microcomputer 15 for arithmetically operating the distance between a subject to be measured and the semiconductor position detecting element 1 by the principle of triangulation on the basis of the averaged voltage, the resistance of one of the resistors connected in series to the input terminals of operating amplifiers constituting the integrating circuits 13, 14 is made variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sanitary device such as an automatic water faucet, a toilet bowl cleaning device, a hot water washing toilet seat, a hand dryer, and a dressing table with a hot air generator. The present invention relates to a sanitary device equipped with a distance sensor that measures the distance to an object to be measured by a triangulation method and uses the distance data as a human body detector or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a semiconductor position detecting element (Position Sensitive Ph) is used.
auto detector 1 as a light receiving element,
The distance from the object 3 to be measured is detected by detecting the spot position on the semiconductor position detecting element 1 where the light emitted from the light emitting element 2 is reflected by the object 3 to be measured and the principle of triangulation is used. An automatic faucet that detects the human body using the distance sensor 5 that measures d, and drives and controls an electromagnetic valve, a hot air fan, etc., a toilet bowl cleaning device, a hot water washing toilet seat, a hand dryer, and a dressing table with a hot air generator. There is a sanitary device such as. The principle of triangulation is to convert the photocurrent values obtained from the two terminals of the semiconductor position detecting element 1 into voltage values and calculate the distance d based on these voltage values.

FIG. 3 is a circuit diagram of the distance sensor 5 used in the conventional sanitary device. As shown in FIG. 3, the photocurrent values I1 and I2 obtained from the two terminals of the semiconductor position detecting element 1 are shown. Are converted into voltage values V1 and V2 using current / voltage conversion circuits 11 and 12. Current /
The voltage conversion circuit 11 includes an operational amplifier OP1 and a resistor R1, and the current / voltage conversion circuit 12 includes an operational amplifier OP2.
And resistor R2.

A capacitor C1 is connected to the output side of the operational amplifier OP1, and a capacitor C2 is connected to the output side of the operational amplifier OP2. Further, an integrating circuit 13 having a resistor R21 as an input resistance is connected to the capacitor C1,
An integrating circuit 14 having a resistor R22 as an input resistor is connected to the capacitor C2. The integrating circuits 13 and 14 are composed of operational amplifier circuits, and the current / voltage converting circuits 11 and 1 are
It is provided for averaging the voltage values V1 and V2 output from the circuit 2. The voltage values V1 and V2 averaged by the integrating circuits 13 and 14 are A / D converters 23 and 24.
When it is input to the micro computer 15 after being converted into a digital value by, the micro computer 15 detects the semiconductor position on the basis of the triangulation principle based on the averaged digital values of the voltage values V1 and V2. The distance between the element 1 and the DUT 3 is calculated, and a detection signal is output when the distance is less than or equal to a threshold value.

On the other hand, a transistor Q1 is connected to the microcomputer 15 via a resistor R3, and when a light emitting pulse is output from the microcomputer 15, the transistor Q1 is synchronized with the light emitting pulse. Then it is turned on. Then, when the transistor Q1 is turned on, the power supply voltage V
A current is passed from B to the light emitting element 2, and the light emitting element 2 emits light intermittently. Also, the microcomputer 15 has an A
A / D converter 25 is connected, and a variable resistor VR26 is connected to the A / D converter 25, and the threshold value of the detection distance is set by adjusting the variable resistor VR26.

As a result of intermittent light emission from the light emitting element 2, the reflected light reflected by the DUT 3 is intermittently received by the semiconductor position detecting element 1. Therefore, the current / voltage conversion circuit 11,
The voltage values V1 and V2 output from 12 change during light projection and during non-light projection. Therefore, the microcomputer 15
Calculates the fluctuations of the voltage values V1 and V2 at the light projection and non-lighting timings by digital values, and calculates the distance between the semiconductor position detecting element 1 and the DUT 3 for the fluctuations. If the distance is less than or equal to the threshold value, a detection signal is output. The current / voltage conversion circuit 11
The voltage value V1 output from the
1 = E1−I1 · R1), and the voltage value V2 output from the current / voltage conversion circuit 12 is a difference {V2 = (E1 + E2) + (I1) from the reference voltage (E1 + E2).
+ I2) .R2}.

[0007]

In the conventional distance sensor 5, the A / D converters 23 and 24 used when converting the voltage values V1 and V2 into digital values, and the A / D converter of the threshold value setting circuit. An inexpensive 8-bit type is used for the D converter 25. Therefore, the maximum combined output of this 8-bit type A / D converter is 256 steps, and 0 to 2
Only values up to 55 can be taken. That is, the maximum resolution of the light receiving point received by the semiconductor position detecting element 1 is 255, and if the digital output value of the A / D converter 25 of the threshold value setting circuit is V, V = 0 to 255 Can only be set within the range. The threshold is (J / I) s,
(However, J is the output value of the A / D converter 23, and I is A / D
(The output value of the D converter 24), the microcomputer 15 determines the value of J / I and the threshold value (J / I) s.
When the value of J / I is smaller than the threshold value (J / I) s, a detection signal of a human body or the like is output.

In FIG. 2, the distance to be set is d, the distance between the lenses 21 and 22 is B, the distance between the lenses 21 and 22 and the semiconductor position detecting element 1 is f, and the light receiving length of the semiconductor position detecting element 1 is Is L, and if I is 255, J is 1
It can be set in steps. At this time, I / J = (L ·
From d) / (B · f), d = (I · B · f / L) × (1
/ J), and under the above conditions, (I · B · f / L) is a fixed value, and d is inversely proportional to J. Therefore, the farther the d is set, the wider the step width. In FIG. 4, d = (I · B · f /
L) × (1 / J) is a graph schematically showing that the farther the distance, the rougher the setting becomes (the wider the step width is). Of course, the A / D converters 23, 2
4, and if the A / D converter 25 of the threshold value setting circuit has a large number of bits, this problem can be solved to some extent, but there is a problem that the cost becomes high.

In view of the above, the present invention provides a distance sensor which can make the step width uniform even if the set distance d is distant or near, without increasing the cost, and a sanitary device using this distance sensor can be used by a user or the like. The technical problem to be solved is to enable accurate detection.

[0010]

The technical means for solving the above-mentioned problems is to provide a light emitting element which emits light in synchronization with intermittent light emitting timing and a photocurrent which is proportional to the light incident position corresponding to the incident position of light. A semiconductor position detecting element as a light receiving element, a current / voltage converting circuit for converting each of the photocurrents of the semiconductor position detecting element into a voltage, and each voltage output from the current / voltage converting circuit as a capacitor. An integrating circuit using an operational amplifier for inputting via a resistor and averaging, an A / D converting circuit for converting the respective averaged voltages into digital values, and respective output from each A / D converting circuit. The distance between the object to be detected and the semiconductor position detecting element is calculated based on the digital value by the principle of triangulation method, and when the distance is less than the threshold value, the object is detected and the detection signal is output. In a sanitary device such as an automatic water faucet or a toilet bowl cleaning device using a distance sensor having a distance calculating means, one of the resistors connected in series to the input terminals of the operational amplifiers forming the integrating circuit has a resistance value. It is to be variable.

[0011]

According to a sanitary device such as an automatic faucet and a toilet bowl cleaning device using the distance sensor having the above-mentioned configuration, one of the resistors connected in series to the input terminals of the respective operational amplifiers constituting the integrating circuit is a variable resistor. Therefore, the variable resistor is adjusted so that the two photocurrent conversion voltages averaged by each integration circuit and converted into a digital value by each A / D conversion circuit become, for example, 1: 1 and the threshold value is set. If set, the distance between the object to be sensed and the distance sensor will be proportional to the ratio of the resistance values of the two resistors connected in series to the input terminals of each operational amplifier, and the detection distance will be short even at a long distance. But the step size is constant.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an electronic circuit of a distance sensor 10 provided in a sanitary device such as an automatic water faucet, a toilet bowl cleaning device, a hot water cleaning toilet seat, a hand dryer, and a dressing table with a hot air generator.

The distance sensor 10 will be described below.
The same components as those constituting the conventional distance sensor 5 will be described with the same reference numerals. As shown in FIG. 1, the current / voltage conversion circuit 11 for converting the respective photocurrent values I1 and I2 obtained from the two terminals of the semiconductor position detecting element 1 into voltage values V1 and V2 includes an operational amplifier OP1 and a resistor. The current / voltage conversion circuit 12 includes an operational amplifier OP2 and a resistor R2.

A capacitor C1 is connected to the output side of the operational amplifier OP1, and a capacitor C2 is connected to the output side of the operational amplifier OP2. Further, an integrating circuit 13 using an operational amplifier having a resistor R21 as an input resistance is connected to the capacitor C1, and an integrating circuit 14 using an operational amplifier having a series resistance of the resistor R22 and the variable resistor VR1 as an input resistance is connected to the capacitor C2. Has been done. This integration circuit 1
Reference numerals 3 and 14 are provided to average the voltage values V1 and V2 output from the current / voltage conversion circuits 11 and 12. When the voltage values V1 and V2 averaged by the integrating circuits 13 and 14 are converted into digital values by the A / D converters 23 and 24 and then input to the micro computer 15, the micro computer 15 receives them. 15 is an A / D converter 2
The distance between the semiconductor position detecting element 1 and the object to be measured 3 is calculated based on the digital value from 3, 24 by the principle of triangulation, and the detection signal is output when the distance is less than the threshold value. .

On the other hand, a transistor Q1 is connected to the micro computer 15 via a resistor R3, and when a light projecting pulse is output from the micro computer 15, the transistor Q1 is synchronized with the light projecting pulse. Then it is turned on. Then, when the transistor Q1 is turned on, the power supply voltage V
A current is passed from B to the light emitting element 2, and the light emitting element 2 emits light intermittently.

Further, in the light emission level reduction circuit 16, the output voltage value V2 of the current / voltage conversion circuit 12 is changed to the capacitor C.
2 is input to the non-inverting terminal (+) of the operational amplifier OP3. On the other hand, a reference voltage obtained by dividing the power supply voltage VB by the resistors R5 and R6 is applied to the inverting terminal (−) of the operational amplifier OP3. An integrating circuit 17 including a resistor R7, a capacitor C3, and a resistor R8 is connected to the output terminal of the operational amplifier OP3. An NPN-type transistor Q2 is connected to the output side of the integration circuit 17, and as the output voltage of the integration circuit 17 increases, that is, when the intensity of ambient light incident on the semiconductor position detection element 1 is higher. Since the base voltage of the transistor Q2 becomes high, the internal resistance of the transistor Q2 (resistance between collector and emitter)
Becomes low, the internal resistance (collector-emitter resistance) of the transistor Q1 connected to the collector of the transistor Q2 becomes high, and the light emission amount of the light emitting element 2 is automatically reduced. Is done normally.

In the distance sensor 10 configured as described above, since the resistor R22 and the variable resistor VR1 are connected to the input terminal of the operational amplifier of the integrating circuit 14, this input resistance can be changed variously. . Further, like the conventional distance sensor 5, the current / voltage conversion circuit 11
The voltage value V1 output from V1 = V1 = E1−I1 · R1
And the voltage value V2 output from the current / voltage conversion circuit 12 is V2 = (E1 + E2) + (I1 + I2) .R2
Is.

The voltage V1c output from the capacitor C1 is V1c = -I1R1 and the voltage of the capacitor C2 is
The voltage V2c output from V2c = (I1 + I2)
・ It is R2. Here, (R22 + VR1) = kR21
(However, if k is a value of 1 or more), k = (R22 + V
R1) / R21, and k is the ratio of the input resistance values of the operational amplifiers of the integrating circuits 14 and 13. Now (R2
2 + VR1) = 2R21 (k = 2), V1 / V
The threshold value is 2 = 1/2, and if V1 / V2 is larger than 1/2 in the comparison between V1 / V2 and 1/2, the microcomputer 15 outputs a detection signal.

As shown in FIG. 2, the distance to be set is d, the distance between the lenses 21 and 22 is B, the distance between the lenses 21 and 22 and the semiconductor position detecting element 1 is f, and the semiconductor position detecting element 1 is
If the length of light that can be received is L, then (I1 + I2) / I1 =
L · d / B · f, and d = (B · f / L) × {(I1
+ I2) / I1}. In addition, the A / D converters 23, 2
The digital values J and I from 4 are J = (R1 / R21)
From I1 and I = (R2 / k.R21). (I1 + I2), d = (B.f / L) .times. (I / J) .times.k. , As shown in FIG.
d is proportional to k. Therefore, the detected object 3 and the distance sensor 1
The distance d between 0 and 0 becomes a value proportional to the ratio of the resistance values of the two resistors connected in series to the input terminals of the operational amplifiers of the integrating circuits 13 and 14, and the step width is set regardless of whether the detection distance is distant or near. Is constant.

The above-described distance sensor 10 detects and non-detects the object to be measured 3 with the set threshold value as a boundary. Therefore, at this boundary, detection and non-detection are repeated for a short period of time, resulting in instability. May be in a different detection state. for that reason,
The microcomputer 15 sets the above I = J as a threshold value before the detection of the DUT 3, and after the detection, the I = J after the detection.
Is set as Ia, and Ia = 0.9I is controlled, and when the non-detection state is set, the threshold value of I = J is returned. By the above control, it is possible to create a hysteresis state of detection and non-detection and prevent repetition of short time intervals of detection and non-detection. The threshold distance after detection is d /
It will be increased to 0.9.

The distance sensor 10 described above is a urinal,
It can be used for detecting a user of a toilet bowl or the like, or for detecting a user of a washing device for a vanity, and for detecting a user of a hand dryer.

[0022]

As described above, according to the present invention, a light emitting element that emits light in synchronization with intermittent light emitting timing and a light receiving element to which a photocurrent is proportionally supplied corresponding to the incident position of light are provided. Semiconductor position detecting element, a current / voltage converting circuit for converting each of the photocurrents of the semiconductor position detecting element into a voltage, and respective voltages output from the current / voltage converting circuit via a capacitor and a resistor. Based on an integrating circuit using an operational amplifier for inputting and averaging, an A / D converting circuit for converting each of the averaged voltages into a digital value, and each digital value output from each A / D converting circuit A distance calculating means for calculating the distance between the object to be detected and the semiconductor position detecting element by the principle of triangulation, detecting the object to be detected when the distance is less than a threshold value, and outputting the detection signal. Automatic faucet using the distance sensor,
In a sanitary device such as a toilet bowl cleaning device, one of the resistors connected in series to the input terminals of the respective operational amplifiers forming the integrating circuit has a variable resistance value, so that the distance between the object to be detected and the distance sensor is increased. The distance becomes a value proportional to the ratio of the resistance values of the two resistors connected in series to the input terminals of the respective operational amplifiers, and the step width can be made constant regardless of whether the detection distance is distant or near. Further, when the detected object is detected, the predetermined threshold value is reduced at a predetermined ratio, and when the detected object moves to the non-detection position, the threshold value is returned to the original value. In this case, the detection of the detected object and the non-detection state are prevented from being repeated at short intervals, and stable detection can be performed.

[Brief description of drawings]

FIG. 1 is a circuit block diagram of a distance sensor for a sanitary device.

FIG. 2 is an explanatory diagram of a distance measurement principle of a distance sensor.

FIG. 3 is a circuit block diagram of a conventional distance sensor.

FIG. 4 is a characteristic diagram showing distance detection characteristics of a conventional distance sensor.

FIG. 5 is a characteristic diagram showing distance detection characteristics of the distance sensor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 semiconductor position detection element 2 light emitting element 11 current / voltage conversion circuit 12 current / voltage conversion circuit 13 integration circuit 14 integration circuit 15 micro computer 23 A / D converter 24 A / D converter R21 resistance R22 resistance VR1 variable resistance Container C1 capacitor C2 capacitor

Claims (2)

[Claims] 1. A light emitting element that emits light in synchronization with an intermittent light emitting timing, a semiconductor position detecting element as a light receiving element to which a photocurrent is proportionally supplied in correspondence with an incident position of light, and the semiconductor position. A current / voltage conversion circuit that converts each photocurrent of the detection element into a voltage, and an integrating circuit using an operational amplifier that inputs each voltage output from the current / voltage conversion circuit via a capacitor and a resistor and averages the voltage. And an A / D conversion circuit for converting the respective averaged voltages into digital values, and between the detected object and the semiconductor position detection element based on the respective digital values output from the respective A / D conversion circuits. Calculate the distance of by the principle of triangulation,
When the distance is less than the threshold value, the detected object is detected,
In a sanitary device such as an automatic water faucet or a toilet bowl cleaning device using a distance sensor having a distance calculating means for outputting the detection signal, resistors connected in series to the input terminals of the respective operational amplifiers forming the integrating circuit. A sanitary device using a distance sensor, one of which has a variable resistance value. 2. The distance calculation means reduces the predetermined threshold value at a predetermined ratio when the detected object is detected, and when the detected object moves to a non-detected position, the threshold value is set to the original value. A sanitary device using a distance sensor characterized by returning to a value.