JP2757330B2 - Valve drive control method for automatic faucet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve driving control method for an automatic faucet which detects an object such as a hand by a sensor and automatically discharges water by opening a valve.

[0002]

2. Description of the Related Art When a hand is put under a water outlet of a faucet, a sensor detects this, and
Automatic faucets that automatically discharge water are widely used. Thus, in the case of a conventional automatic faucet, the sensor only detects the presence or absence of an object, that is, it is not determined whether the object is a dynamic object or a static object. Such inconvenience has occurred.

For example, using a photoelectric sensor as a sensor,
The light emitting unit emits light and the light reflected by the object is received by the light receiving unit. When the amount of received light is equal to or more than a certain amount, it is determined that the object is present, the valve is driven to open, and water is automatically discharged from the water outlet. Such a faucet is considered, but in this case, the sensor determines only the presence or absence of the object, for example, if this kind of automatic faucet is installed in the sink of the kitchen sink,
If dishes or the like are stacked below the water outlet, the sensor will detect this and continue to supply water.

In order to prevent this, it has been considered to automatically stop water discharge by a timer when water is continuously discharged for a certain period of time, but in this case, water continues to flow from the water discharge port for a long time and is wasted. There's a problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and the gist of the present invention is to detect an object such as a hand by a sensor and open a valve based on the detection signal. What is claimed is: 1. A method of driving a valve of an automatic faucet of a type that automatically drives and discharges water, wherein said sensor is a photoelectric sensor having a light-emitting unit and a light-receiving unit for receiving light reflected by an object. After the light receiving signal from the differential wave is differentiated, the peak value of the differential wave is compared with the set value, and the measurement time interval T from the differential wave exceeding the set value to the next differential wave is set to the set time interval T _1. T <the valve when T ₁ is the open state, T> Te is the valve when the T ₁ to the closed drive.

[0006]

According to the present invention, it is possible to discriminate whether an object is a dynamic object or a static object and control the drive of the valve. For example, when the object is a dynamic object, the amount of light received by the light receiving unit changes greatly according to the movement of the object. Therefore, when the light receiving signal is differentiated, the peak value of the differential wave increases, and the peak value of the differential wave increases while the object continues to move. On the other hand, when the object is stationary, the change in the amount of received light is small and the peak value of the differential wave is small.

Therefore, a time interval T from the differential wave exceeding the set value (threshold value) to the differential wave is measured, and when T <T ₁ with respect to the set time T ₁ , the valve is opened and the water is opened. the continued out, also T> when T ₁ if ask spouting stop valve and closing drive, continued water discharge only if the object is a dynamic object, or static object when the motion has stopped When the object enters the detection range of the sensor, keep the water discharge stop state,
Useless water discharge can be prevented.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; In FIG. 3, reference numeral 10 denotes an automatic faucet installed on a kitchen sink, and reference numerals 12 and 14 denote a light emitting unit and a light receiving unit in the photoelectric sensor. The automatic faucet 10 emits infrared light from the light emitting unit 12, and receives light reflected by an object such as a hand by the light receiving unit 14. As a result, when it is determined that there is an object, the valve 28 (FIG. 1) is opened to automatically discharge water from the water discharge port 16.

FIG. 1 shows various elements of a control unit in the automatic faucet 10, including a light emitting unit 12 and a light receiving unit 1 in a photoelectric sensor.
4, a block diagram together with a valve drive circuit 26 and a valve 28. In this automatic faucet 10,
The light reflected by the object is received by the light receiving unit 14, converted into a voltage signal and amplified, and output to the differentiating circuit 18. A differentiating circuit 18 differentiates the output signal, and a comparing circuit 20
In step S3, the peak value of the differential wave 30 (see the time chart in FIG. 2) is compared with a set value (threshold) P.

The time measuring means 22 measures a time interval T from the differential wave 30 exceeding the set value P to the differential wave 30 exceeding the next set value P, and the comparing circuit 24 determines the measured time T as a predetermined setting. It is compared with the value T _1. The T <while satisfying the relationship of T ₁ is the valve drive circuit 26 continues to supply open drive signal to the valve 28, also T> supplies a close drive signal when a relation of T _1.

The differentiating circuit 18 captures a change in the amount of light received by the light receiving unit 14, and this change is, for example, performed by the light receiving unit
This can be realized by converting the received light into a voltage signal by a light receiving circuit including an integrating element in 4. In this case, when the object is a dynamic object, the change in the amount of received light for each light emission pulse is large, as shown in the time chart of FIG. 2, while the change in the amount of received light is small for a static object. Thus, the peak value of the differential wave is large in the former, and small or hardly appears in the latter.

Therefore, as shown in FIG.
Is provided and by comparing the magnitude of the differential wave, it can be determined whether the object is a dynamic object or a static object. Other means for outputting a change in the amount of received light as a signal are also possible.

Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention is applicable to an automatic faucet of a retrofit type attached to a spout of an existing faucet, In addition, the present invention can be applied to an automatic faucet installed in various places other than a kitchen, and can be implemented in a form in which various changes are made based on the knowledge of those skilled in the art without departing from the gist thereof. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing various elements of a control unit in an automatic faucet of the present invention, together with a light emitting unit, a light receiving unit, a valve drive circuit, a valve, and the like of a photoelectric sensor.

FIG. 2 is a time chart when opening / closing drive control of a valve is performed according to a change in a light receiving signal.

FIG. 3 is a diagram showing an example of an automatic faucet to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Automatic faucet 12 Light emitting part 14 Light receiving part 16 Outlet 28 Valve 30 Differential wave

Claims (1)

(57) [Claims] 1. A method of driving a valve of an automatic faucet of a type in which an object such as a hand is detected by a sensor and the valve is driven to open and discharge automatically based on the detection signal, wherein the sensor comprises a light emitting unit There is no photoelectric sensor having a light receiving unit that receives light reflected by the object, and after differentiating the light receiving signal from the light receiving unit, comparing the peak value of the differentiated wave with a set value, and comparing the set value. it from exceeding the derivative wave <to the valve when the T ₁ in an open state, T> T with respect to the measurement time interval T the set time interval T ₁ of the until the next differentiated wave the valve when the T ₁ to drive for closing A valve driving control method for an automatic faucet, comprising: