JPH07301521A - Object detector - Google Patents

Abstract

PURPOSE:To surely detect a human body by using a PSD while the consumption of a battery is minimized. CONSTITUTION:A control circuit 8 makes an LED 11 emit light by turning on a transistor 14 and detects a human body in a detecting area by inputting detecting signals V1 and V2 from the light receiving signal of a PSD 18. A valve driving circuit 23 flushes a urinal. A battery 9 which is provided as a power source supplies electricity to each section through a constant-voltage circuit 10. When the light receiving level of the PSD 18 becomes lower due to light projecting operations, the control circuit 8 increases the current supplied to the LED 11 by turning on a transistor 15 so as to stabilize the light receiving level of the PSD 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detecting device for detecting an object by receiving light reflected by a semiconductor position detecting element when light is projected toward a detection area.

[0002]

2. Description of the Related Art Conventionally, as this type, for example,
There is an object detection device provided in a men's toilet or the like. This is after the human body is close to the men's urinal
When the human body moves away, this is detected and the washing operation is automatically performed.

Specifically, a projector is used to project light in front of a male urinal, and the reflected light is detected by a light receiver when a human body approaches the urinal, and the reflected light is detected after the human body has been detected for a certain period of time or longer. When it is detected that the human body is moving away due to no light, it is configured to automatically perform the cleaning operation by driving the flush valve to the open state for a predetermined time, assuming that it has been used. However, in the case of such a configuration, in the case where the detection of the reflected light by the light receiver is configured as a detection method based on the amount of received light, for example, when wearing clothes such as black having a low reflectance, the human body Since the amount of the reflected light when reflected by is reduced, there is a problem that the human body is erroneously detected as absent even though the human body exists in the detection area.

Therefore, conventionally, detection is performed by providing a distance-measuring light receiving unit such as a semiconductor position detecting element that receives light at different positions according to the position of the human body, rather than by the amount of reflected light. It is considered. With such a configuration, the presence or absence of the human body can be accurately detected regardless of the reflectance due to the difference in the color of clothes worn by the human body.

[0005]

By the way, in the case of the above-described distance-measuring type, when detecting a human body wearing black clothes, the amount of received light itself decreases, so it is necessary to determine whether or not there is a human body. For reliable detection, it is necessary to set a high light projection amount by the light projector. However, in the case where the detection device is configured to be driven by a battery, increasing the amount of light projected will lead to faster consumption of the battery, and
When there is no need to increase the light projection amount, there is a problem that wasteful power is consumed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to reliably detect a human body while minimizing the consumption of a battery with a structure in which a distance measuring type light receiving unit is provided. An object of the present invention is to provide an object detection device that can be used.

[0007]

SUMMARY OF THE INVENTION An object detecting apparatus of the present invention comprises a light projecting means for projecting light toward a detection area, and a light projecting control for powering the light projecting means from a battery power source to perform a light projecting operation. Means, a semiconductor position detecting element that receives reflected light from the detected object and receives light at a position corresponding to the distance to the detected object, and the distance of the detected object based on the detection signal of the semiconductor position detecting element. The light emitting control means includes a detecting means for calculating the presence or absence of an object in the detection area and a judging means for judging the light receiving level from the detection signal of the semiconductor position detecting element. It is characterized in that it is configured to control so that the light projecting amount of the light projecting means is increased when the light receiving level due to is less than a predetermined level.

Further, when the light receiving level by the judging means has not reached a certain level,
It is advisable to control so that the light projection amount of the light projecting means is increased so that the light receiving level becomes a constant level.

Further, the judging means is composed of an adding circuit for adding the detection signals from the semiconductor position detecting element to detect a signal corresponding to the amount of received light, and the light projecting control means is for outputting the output of the adding circuit. It can be configured by an adjusting circuit that adjusts the light projection amount of the light projecting means so that the light receiving level becomes a constant level based on a signal.

[0010]

According to the object detecting device of the present invention, when the light projecting control means supplies power from the battery power source to cause the light projecting means to carry out the light projecting operation toward the detection area, the object to be detected is detected in the detection area. When an object is present, the reflected light is incident on the position corresponding to the distance of the light receiving surface of the semiconductor position detecting element. Therefore, the detection means calculates the position of the detected object and the presence of the object in the detection area. The presence or absence of will be detected.
At this time, the determining means calculates the sum of the detection signals of the semiconductor position detecting elements to determine the light receiving level, and the light projecting control means determines the light receiving level of the light projecting means when the light receiving level is equal to or lower than a predetermined level. Control to increase the amount of light.

As a result, for example, when the surface of the object to be detected is black or when the reflectance is low due to a material that is difficult to reflect, the light receiving level of the semiconductor position detecting element may be low. Since the amount of light emitted is increased,
In the semiconductor position detecting element, the light is incident at a stable light receiving level, and therefore, a stable detection state can be maintained at all times, and since the amount of projected light does not increase unnecessarily, consumption of the battery power source is reduced. Power saving can be achieved.

According to the object detecting device of the second aspect, when the light receiving level of the semiconductor position detecting element with respect to the light reflected from the object to be detected has not reached a certain level, the light projecting control means has a certain light receiving level. Since the light projecting amount of the light projecting means is controlled so as to be at the level, the semiconductor position detecting element can always perform the detecting operation at a stable light receiving level.

According to the object detecting device of the third aspect, the adder circuit constituting the judging means adds the detection signals from the semiconductor position detecting elements to detect a signal corresponding to the light receiving level, and the light emitting control means is operated. Since the adjusting circuit to be constructed adjusts the light projecting amount of the light projecting means so that the light receiving level thereof becomes constant, the semiconductor position detecting element has a simple structure in addition to that of the conventional structure. Can always perform detection operation at a stable light reception level.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a human body sensor provided in an automatic flushing device for a male urinal will be described below with reference to FIGS. Figure 2
Shows the overall structure of the device. The wall surface 1 is provided with a men's urinal 2 and the wall surface 1 is attached to the upper part of the urinal 2.
A water supply pipe 4 is connected from the inner surface side of the above through a main valve 3. The main valve 3 is controlled by a pilot valve 5 for water supply, and the pilot valve 5 is electrically driven by an automatic water washing device 6.

The automatic flushing device 6 is installed so as to be embedded in the wall surface 1 at the upper part of the urinal 2, and detects a person approaching the urinal 2 and detects that the person has gone away. The pilot valve 5 is opened for a certain period of time to control the water supply by the main valve 3, and a detection window portion 7 for emitting and receiving light is provided on the front surface of the resin body case 6a.
Are integrally formed.

FIG. 1 shows the electrical configuration of the automatic water washing apparatus 6, in which the control circuit 8 is a microcomputer, RO.
It is composed of an M, a RAM, an A / D converter, and the like, and has a function as a projection control means and a determination means. The control circuit 8 includes a battery 9 to a constant voltage circuit 1
Power is supplied via 0.

The LED 11 as the light projecting means is supplied with power from a DC power supply terminal Vcc connected to the output terminal of the constant voltage circuit 10, and is grounded via resistors 12 and 13 and a driving npn transistor 14. There is. Also, L
The collector of the npn-type transistor 15 for increasing the light emission amount of the ED 11 is connected to the common connection point of the resistors 12 and 13. The bases of the transistors 14 and 15 are connected to the output terminals A and B of the control circuit 8 via the resistors 16 and 17, respectively.

A semiconductor position detecting element (hereinafter abbreviated as PSD) 18 outputs detection currents I1 and I2 from two output terminals a and b according to the light receiving position on the light receiving surface.
The light output from the LED 11 is received at a light receiving position corresponding to the distance to the position where the light is reflected. This P
The output terminals a and b of the SD 18 are connected to the input terminals C and D of the control circuit 8 via the current / voltage conversion circuits 19 and 20 and the amplifier circuits 21 and 22, respectively. The detection currents I1 and I2 of the PSD 18 are converted into voltage signals v1 and v2 by the current-voltage conversion circuits 19 and 20, and then the amplification circuit 2
The voltage signals V1 and V2 amplified by 1 and 22 are input to the control circuit 8.

Then, the above-mentioned LED 11 and PSD
Reference numerals 18 are laterally arranged at predetermined intervals in the detection window portion 7 of the main body case 6a. Further, the valve drive circuit 23 is connected between the output terminals E and F of the control circuit 8, and when a drive signal is applied, a constant voltage circuit 10 supplies drive power to the pilot valve 5 to open / close it. Is. The condition setting circuit 24 is for setting the cleaning time and the like, and is connected to the input terminal G of the control circuit 8.

Next, the operation of this embodiment will be described with reference to the flowchart of the control program shown in FIG. The flowchart of the control program shown in FIG. 3 shows a part relating to the control for setting the light projection amount in the detection operation. The routine of the part for performing the light projection operation to calculate the distance to the human body which is the detected object Is. That is, the control circuit 8 first outputs a light projecting signal from the output terminal A to turn on the transistor 14 (step S1), and the LED 11
Is energized to perform a light projecting operation toward the detection area. In addition,
The above-described light projecting operation is performed, for example, about once a second, and the consumption of the battery 9 is reduced as much as possible so that the detection operation is not hindered.

Next, the control circuit 8 receives the detection signals V1 and V2 input to the input terminals C and D during the light projecting operation and stores them as A / D converted digital data (step S2). In this case, the PSD 18 outputs the reflected light incident from the detection area side as the light receiving signals I1 and I2 corresponding to the distance. Then, the current-voltage conversion circuit 1
The voltage signals v1 and v2 are converted into voltage signals v1 and v2 at 9 and 20, and are input to the control circuit 8 as detection signals V1 and V2 amplified by the amplifier circuits 21 and 22. And
When the human body is present in the detection area, the reflected light that reaches the minimum detection level is incident on the PSD 18, and when the human body is not present, the reflected light is mostly incident on the PSD 18. Since there is no light, the received light level does not reach the minimum detection level.

Next, the control circuit 8 determines whether or not the sum Vo of the detection signals V1 and V2 corresponding to the total received light amount Io by the PSD 18 is equal to or higher than the minimum detection level (step S3). This is the detection signals V1 and V of the PSD 18.
2 determines whether or not the level is a level indicating the presence of a human body in the detection area.
When it is determined to be "O", this program is terminated and the process returns to the control program, and when it is determined to be "YES", the process proceeds to step S4.

Subsequently, the control circuit 8 judges whether or not the light receiving level Vo corresponding to the total light receiving amount Io exceeds a stable light receiving level VT which is a predetermined level capable of stably maintaining the detection operation, and "YES". In this case, the process proceeds to step S5, the signal SL corresponding to the distance is obtained from the detection signals V1 and V2 according to the following equation, and the distance is calculated from the signal SL (step S6). SL = (V1-V2) / (V1 + V2) Thus, when the distance to the human body existing in the detection area is obtained, the control program is returned to and the processing based on the human body detection is executed.

In this case, the control circuit 8 thereafter executes the detection program again to detect that the human body has moved away from the urinal 2, and outputs the drive signals from the output terminals E and F as the ones which have been used. Then, the valve drive circuit 23 drives the pilot valve 5 to open and close for the time set by the condition setting circuit 24 to wash the urinal 2.

Now, in the above-mentioned step S4, "NO"
If so, the control circuit 8 proceeds to step S7 to output a drive signal from the output terminal B to turn on the transistor 15 in order to increase the light projection amount. As a result, since the LED 11 is energized only through the resistor 12, the energization current is increased, so that the light emission intensity is increased and the light projection amount is increased. Then, thereafter, the control circuit 8 again detects the detection signal V corresponding to the received light signals I1 and I2 output from the PSD 18.
1, V2 is input to perform A / D conversion, and then steps S5 and S6 are executed to obtain the distance.

In the above description, when the transistor 14 is turned on, for example, when the human body in the detection area is wearing black clothes, or is wearing clothes made of a material having a low reflectance. The amount of light emitted by the LED 11 is PS
A condition in which the reflected light having a sufficient received light level is not incident on D18 is detected, and in this case, the detection operation of the human body cannot be performed in a stable state, and the human body exists in the detection area. This is a case in which an erroneous detection is made such that it is determined that the user has gone farther on the way, even if is continued. Even in such a case, it is possible to make the reflected light of a sufficient light receiving level incident on the PSD 18 by increasing the light projection amount, so that the stable detection operation can be continued. Become.

According to this embodiment, the control circuit 8
As a result, the light receiving level Vo is obtained from the sum of the detection signals V1 and V2 of the PSD 18, and when the value is lower than the stable light receiving level VT, the transistor 15 is turned on to increase the energizing current of the LED 11 to increase the light emitting amount. Since the number of light sources is increased, the light emission amount can be increased only when necessary such that the detection state of the detected object such as a human body becomes unstable, and the consumption of the battery 9 is reduced as much as possible. It becomes possible to perform a stable detection operation while reducing the power consumption.

FIGS. 4 to 6 show a second embodiment of the present invention, and the portions different from the first embodiment will be described below. That is, in the light projecting circuit portion, the LED 1
1 is grounded via the resistor 25 and the transistor 14, and is also grounded via the resistor 26 and the transistor 15. The arithmetic circuit 27 having the functions of an adder circuit and an adjusting circuit is configured such that the detection signals V1 and V2 are input to the one input terminal from the amplifier circuits 21 and 22 through the resistors 28 and 29, respectively. The reference voltage Vs set by the voltage dividing resistors 30 and 31 connected between the DC power supply terminal Vcc and the ground is input to the other input terminal. In addition, the arithmetic circuit 2
The power supply 7 is supplied from the DC power supply terminal Vcc through the switch circuit 32.

The switch circuit 32 is adapted to be supplied with a switch signal from the output terminal H of the control circuit 8 to perform the power feeding operation to the arithmetic circuit 27. The control circuit 8 has the input terminal C. , D when the received light level Vo obtained by adding the detection signals V1 and V2 is equal to or higher than the minimum received light level Vmin, a switch signal is output from the output terminal H.

The arithmetic circuit 27 is composed of the switch circuit 3
When the power is supplied by the resistor 2,
When the added value of the detection signals V1 and V2 input via 8 and 29 is lower than the stable light receiving level VT set by the reference voltage Vs, the transistor 15 is driven via the resistor 17 and the light receiving level Vo becomes The light emission amount of the LED 11 is controlled to increase so as to reach the stable light reception level VT.

The control circuit 8 executes the detection operation according to the flow chart of the detection program shown in FIG. The timing of the signals of the respective parts in this detection operation is shown in the time chart of FIG. Then, in the following description, first, a case where a human body exists in the detection area will be described, and subsequently, a case where a human body does not exist will be described.

That is, in step T1, the control circuit 8 outputs a light emission signal (see FIG. 6A) from the output terminal A to turn on the transistor 14 (time t0), and the LED
11 to perform a light projecting operation of projecting light toward a detection area with a predetermined light projecting amount (see (e) in the same figure).
2, the detection signals V1 and V2 corresponding to the light reception signals I1 and I2 of the PSD 18 are input during the judgment period Ta (time t0 to t1) shown in FIG. Become.

Next, when the control circuit 8 proceeds to step T3, it determines whether or not the added value Vo of the input detection signals V1 and V2 has reached the minimum light receiving level Vmin. This shows the minimum light receiving level required when a human body is present in the detection area. In this case, it is assumed that a human body is present in the detection area.
The light receiving level Vo (= V1 + V2) exceeds at least the minimum light receiving level Vmin, and the control circuit 8 returns “YES”.
Then, the process proceeds to step T4. When the control circuit 8 proceeds to step T4, it outputs a switch signal from the output terminal H to drive the switch circuit 32 at time t1 (see (c) of the same figure), and then at step T5. , And waits for a predetermined adjustment period Tb (see (d) in the figure).

During the adjustment period Tb, the detection signals V1 and V2 corresponding to the detection currents I1 and I2 of the PSD 18 are input to the calculation circuit 27, and the added value Vo (= V1 + V2) is calculated. At the same time, the light receiving level Vo is compared with the reference voltage Vs set by the voltage dividing resistors 30 and 31, that is, the stable light receiving level VT, and if it is lower than this, the transistor 15 is operated from the output terminal via the resistor 17. As a result, the energization current of the LED 11 is increased and controlled to be equal to the stable light reception level VT. As a result, for example, when the light reception level Vo is low, the light projection amount is increased as shown in FIG. 8E, and the LED is adjusted so that the light reception level Vo becomes the stable light reception level VT.
An energizing current to 11 is set, and in this case, the light projection amount is increased.

Thereafter, the control circuit 8 proceeds to step T6 and detects the detection signals V1 and V2 corresponding to the light receiving signal of the PSD 18.
Is again input during the detection period Tc (see (f) in the figure, between times t2 and t3), and at the time t3, the output of the light projection signal is stopped and the switch circuit 32 is turned off ( Step T7). Subsequently, when the control circuit 8 proceeds to step T8, the calculation period Tg (see (g) in the figure,
(Between times t3 and t4) in the same manner as described above, equation (1)
The signal SL corresponding to the distance is obtained by performing the calculation as shown in (3), and then the distance to the human body is calculated (step T).
9).

As a result, the PSD 18 is output during the period from the time t0 to the time t2 in the output period Tf of the light projection signal.
Is adjusted so that the light receiving level Vo reaches the stable light receiving level VT, and a stable light receiving signal can be obtained during the subsequent detection period Tc.
It will be possible to detect that distance accurately during g.

When there is no human body in the detection area, the control circuit 8 controls the minimum light receiving level Vmi for human body detection.
Since the received light level Vo equal to or higher than n cannot be obtained, it is determined to be “NO” in step T3 described above and step T10.
Then, the output of the light emission signal is stopped and the program ends. Therefore, in this case, FIG.
As shown in, the detection period is equal to Ta, which is shorter than the sum of the detection times Tf and Tg when the human body is present.

Therefore, according to the second embodiment as described above, the light receiving level Vo at the time of detecting a human body is always adjusted to the stable light receiving level VT while the consumption of the battery 9 is reduced as much as the first embodiment. As a result, the distance to the human body can be detected with certainty, and a stable detection operation can be achieved by simply adding a simple circuit configuration.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. In addition to the cleaning device, the present invention can be applied to general devices for detecting a human sensor of an automatic door and other objects. In the first embodiment, step S3 corresponds to the determining means, steps S5 and S6 correspond to the detecting means, and steps S7 and S8 correspond to the adjusting means.

[0040]

As is apparent from the above description, according to the object detecting device of the present invention, the following effects can be obtained.
That is, according to the object detecting device of the first aspect, the determining means determines the light receiving level from the detection signal of the semiconductor position detecting element, and the light projecting controlling means determines when the light receiving level by the determining means is equal to or lower than a predetermined level. Since the amount of light projected by the light projecting means is increased, if the surface of the object to be detected is black or the reflectance is low due to a material that is difficult to reflect, the light receiving level of the semiconductor position detection element is low. However, at this time, the amount of light emitted is increased, so that the semiconductor position detection element enters at a stable light reception level, and therefore a stable detection state can always be achieved, and the light is emitted unnecessarily. Since it does not increase the amount of light,
It has an excellent effect that power consumption can be reduced by reducing consumption of the battery power source.

According to the object detecting device of the second aspect, when the light receiving level of the semiconductor position detecting element for the reflected light from the object to be detected has not reached a certain level, the light projecting control means has a certain light receiving level. Since the light projecting amount of the light projecting means is controlled so that the level becomes the level, the semiconductor position detecting element has an excellent effect that the detecting operation can be always performed at a stable light receiving level.

According to the object detecting device of the third aspect, the adder circuit constituting the judging means adds the detection signals from the semiconductor position detecting element to detect a signal corresponding to the light receiving level, and the light emitting control means is operated. Since the adjusting circuit to be constructed adjusts the light projecting amount of the light projecting means so that the light receiving level thereof becomes constant, the semiconductor position detecting element has a simple structure in addition to that of the conventional structure. Has an excellent effect that the detection operation can always be performed at a stable light reception level.

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing an arrangement portion of a men's urinal.

FIG. 3 is a flowchart of a human body detection program.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG.

FIG. 6 is a time chart showing a signal output state of each part.

[Explanation of symbols]

3 is a main valve, 5 is a pilot valve, 6 is an automatic water washing device, 8 is a control circuit (detection means, light emission control means, determination means), 9 is a battery, 10 is a constant voltage circuit, and 11 is an LED.
(Light emitting means), 14 and 15 are transistors, 18 is a semiconductor position detecting element, 19 and 20 are current-voltage conversion circuits, 2
Reference numerals 1 and 22 are amplifier circuits, 23 is a valve drive circuit, 24 is a condition setting circuit, and 27 is an arithmetic circuit (adding circuit, adjusting circuit).

Claims (3)

[Claims] 1. A light projecting means for projecting light toward a detection area, a light projecting control means for performing a light projecting operation by supplying power to the light projecting means from a battery power source, and receiving light reflected by an object to be detected. Presence or absence of an object in the detection area by calculating the distance between the detected object and a semiconductor position detecting element that receives light at a position corresponding to the distance to the detected object and the detection signal of this semiconductor position detecting element. And a determining means for determining a light receiving level from a detection signal of the semiconductor position detecting element, wherein the light projecting controlling means is configured to project the light receiving level when the light receiving level by the determining means is equal to or lower than a predetermined level. An object detection device characterized by controlling so as to increase a light projection amount of a light means. 2. The light projection control means increases the light projection amount of the light projection means so that the light reception level becomes a constant level when the light reception level by the determination means has not reached a constant level. The object detection device according to claim 1, which is controlled. 3. The determining means is composed of an adder circuit for adding a detection signal from the semiconductor position detecting element to detect a signal corresponding to the amount of received light, and the light emission controlling means is an output signal of the adding circuit. 3. The object detecting device according to claim 1, further comprising an adjusting circuit that adjusts the light projection amount of the light projecting means so that the light receiving level becomes a constant level based on the above.