JP2013064260A - Automatic faucet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic faucet that is free of unexpected malfunction while a body detection sensor detects hot water being discharged and steam being generated from facilities such as a bathtub using the hot water.SOLUTION: The automatic faucet includes: a discharge port which discharges hot water supplied from a water supply path; a solenoid valve connected to the water supply path; a sensor which transmits a propagation wave and detects the amount of reflection thereof; a control unit which determines the start of water discharge when the amount of reflection of the propagation wave is equal to or larger than a first threshold, and determines the end of the water supply when the amount of reflection becomes less than a second threshold smaller than the first threshold; and solenoid valve driving means of driving the solenoid valve on the basis of determination output of the control unit. During water discharge in which the amount of reflection of the propagation wave exceeds the first threshold, the control unit determines the end of water discharge when determining that the amount of reflection of the propagation wave is affected by steam even if the amount of reflection of the propagation wave is equal to or larger than the second threshold.

Description

  The aspect of the present invention generally relates to an automatic faucet provided with a detection sensor, and specifically relates to an automatic faucet that automatically discharges and stops water according to the detection status of the detection sensor.

2. Description of the Related Art Conventionally, an automatic faucet that automatically detects water by detecting a detected object such as a hand is known.
The detection direction of the sensor and the direction of water discharge are preferably the same from the viewpoint of user convenience, and as a result, the detection direction of the sensor is preferably directed to the washbasin.
Therefore, Patent Document 1 is known as an automatic faucet control device in which the detection direction of the sensor is directed to the basin.

In the automatic faucet control device described in Patent Document 1, the infrared light to be projected and the infrared light to be received are polarized, the specular reflection light from the washbasin is not detected, and only the diffuse reflection light from the human body is detected. It is characterized by detecting.
By doing so, even if the material of the basin is such that infrared light is specularly reflected, it is not erroneously detected.

Japanese Patent No. 3726953

However, the automatic faucet control device described in Patent Document 1 has the following problems when water is discharged.
When hot water is discharged from the water outlet, steam is generated around the basin. Moreover, when equipment using hot water such as a bathtub is adjacent, steam may be generated around the basin even if water is discharged from the water outlet. Since steam is a collection of water particles, the projected infrared light is irregularly reflected. Due to the irregular reflection, the light polarized at the time of projection loses the polarization component. And by receiving the light which lost the polarization | polarized-light component, the sensor misdetected and there was a possibility of carrying out an erroneous water discharge.
In addition, even when a polarizing plate is not used, light reception due to diffused reflection in steam occurs, so that the automatic faucet that does not use a polarizing plate also has a problem.
The present invention has been made in order to solve the above-described problems. The object of the present invention is to prevent automatic water from being detected by the detection sensor when steam is generated and causing an unexpected malfunction. To provide a stopper.

In order to achieve the above object, according to the first aspect of the present invention, a spout for discharging hot water supplied from a water supply path, an electromagnetic valve connected to the water supply path, and a propagation wave are transmitted and reflected. When the amount of reflection of the propagation wave and the sensor for detecting the amount is greater than or equal to the first threshold value, it is determined that the water discharge is started, and when it is less than the second threshold value which is smaller than the first threshold value, it is determined that the water discharge is ended. And an electromagnetic valve driving means for driving the electromagnetic valve based on the judgment output of the control unit, wherein the control unit has a reflection amount of the propagation wave as the first amount. If it is determined that the amount of reflection of the propagating wave is the amount of reflection due to the influence of steam even if the amount of reflection of the propagating wave is greater than or equal to the second threshold when exceeding the threshold value of It is characterized in that it is determined to end.
Thereby, even if it is in the state which the steam has generate | occur | produced, it can prevent continuing water discharge accidentally.

According to a second aspect of the present invention, the control unit provides a third threshold value that is larger than the second threshold value and smaller than the first threshold value, and the reflected wave reflection amount is the first threshold value. It is determined that the water discharge has ended when it is greater than or equal to a threshold value of 2 and less than the third threshold value for a certain period of time.
Thereby, even if steam is generated and the amount of propagation wave reflection is high, the determination threshold value for the end of water discharge is set high, so that water discharge does not continue due to steam.

According to a third aspect of the present invention, when the amount of change in the reflection amount of the propagating wave is equal to or greater than the first amount of change, the control unit determines that the water discharge has ended according to the third threshold value. It is characterized by stopping.
Thereby, even if the reflection amount of the propagating wave is less than the third threshold value, the water discharge can be continued by a movement such as hand washing, which may cause the user to feel uncomfortable at the end of the unintentional water discharge. Absent.

According to a fourth aspect of the present invention, the control unit determines the end of water discharge because the amount of reflection of the propagation wave is the amount of reflection due to the influence of steam, so that the determination criterion is greater than the first threshold. In this case, it is determined that water discharge starts.
Thereby, after determining the end of water discharge due to steam, it is possible to prevent erroneous start of water discharge with steam.

According to a fifth aspect of the present invention, when the control unit determines that the water discharge is finished based on the third threshold value, the control unit is smaller than the first threshold value and the third threshold value, and the second threshold value. A fifth threshold value greater than the first threshold value is provided, and a sixth threshold value greater than the first threshold value is provided until the propagation wave reflection amount is less than the fifth threshold value for a certain period of time. According to the sixth threshold value, it is determined that the water discharge is started. Thus, it is possible to prevent the water discharge from being erroneously started with the steam after it is determined that the water discharge has ended with the steam.

According to a sixth aspect of the present invention, when the control unit determines that the water discharge has ended based on the third threshold value, the water discharge is performed when the amount of change in the reflected wave reflection amount is equal to or greater than the second amount of change. It is characterized by determining that it is a start.
Thereby, after determining the end of water discharge due to steam, it is possible to prevent erroneous start of water discharge with steam.

  According to the present invention, when the steam is generated regardless of the steam generated by discharging the hot water by itself or the steam generated from other equipment, the object detection sensor detects the steam and causes an unexpected malfunction. It is possible to provide an automatic faucet that does not have to be performed.

It is a mimetic diagram which illustrates an automatic faucet concerning a 1st embodiment of the present invention. It is a block diagram which illustrates the automatic faucet concerning a 1st embodiment. This is a general waveform when an object detection sensor detects an object to be detected. This is a waveform when steam is generated when the object detection sensor detects an object to be detected. This is a waveform when the object detection sensor detects the object to be detected 13 and the object to be detected has moved far away from the detection area of the object detection sensor as time passes. This is a waveform when the object detection sensor detects an object to be detected, and the object to be detected moves farther to the detection area of the object detection sensor 8 over time. It is a water discharge completion determination flowchart using the 2nd threshold value, the 3rd threshold value, and the 1st change in a water discharge state. It is a waveform at the time of the water stop state after determining with the 3rd threshold value that water stop is complete | finished. It is a waveform at the time of the water stop state after determining with the 3rd threshold value that water stop is complete | finished. It is a water discharge start judgment flowchart using the 1st threshold value, the 5th threshold value, the 6th threshold value, and the 2nd amount of change in a water stop state.

Hereinafter, specific examples of the present embodiment will be described with reference to the drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and detailed description is abbreviate | omitted suitably.
(First embodiment)
From here, the first embodiment (determination of water stoppage) will be described.
FIG. 1 is a schematic view illustrating an automatic faucet according to the first embodiment of the present invention.
As shown in FIG. 1, an automatic faucet 2 according to an embodiment of the present invention is installed on a washstand 1. In the automatic faucet 2, an object detection sensor 8 is arranged next to the faucet body 4, and an object such as a hand in the detection area 12 of the object detection sensor 8 is detected by the object detection sensor 8. The hot water from the faucet body 4 is switched between water discharge and water stop.
In addition, the automatic faucet 2 of this embodiment can be installed in places where water discharge is required, such as a kitchen, in addition to the washstand 1.

FIG. 2 is a block diagram illustrating an automatic faucet according to the first embodiment.
As shown in FIG. 2, the automatic faucet 2 includes a water supply source 28, a hot water supply source 80, a faucet body 4, an object detection sensor 8, a water side solenoid valve 26, a hot water side solenoid valve 82, and a control. Part 10. The control unit 10 includes an electromagnetic valve driving unit 73 and a memory 11, and a first threshold value, a second threshold value, a third threshold value, a fifth threshold value, a sixth threshold value, and a first change described later. It is assumed that the amount and the second change amount are stored in the memory 11.

Water is supplied from a water supply source 28, and further through a water supply hose 52 serving as a water supply path and a water-side electromagnetic valve 26 connected to the water supply hose 53, a single lever type hot / cold water mixing faucet 60 and a water supply hose 85. Then, water is discharged from the water outlet 30 of the faucet body 4.
Further, hot water is supplied from a hot water supply source 80, and further via a hot water side electromagnetic valve 82 connected to a hot water supply hose 81 and a hot water supply hose 86 as a hot water supply path, and a single lever type hot and cold water mixing tap 60 and water supply Hot water is discharged from the water outlet 30 of the faucet body 4 via the hose 85.

Water and hot water can be mixed inside the single lever-type hot / cold water mixing faucet 60, and the water outlet 30 can discharge water only, hot water only, or water mixed with hot water.
Further, by operating the single lever, the amount of water discharged and the mixing ratio of hot water can be changed, and water can be forcibly stopped.

The object detection sensor 8 includes a transmission unit and a reception unit. In this embodiment, the reflection type integration sensor is configured such that the transmission unit includes an infrared light projecting element 20 and the reception unit includes an infrared light receiving element 22. Will be described. That is, the propagation wave emitted from the light projecting element 20 is an infrared emission wave, and the reflected wave received by the light receiving element 22 is infrared reflected light.
The light projecting element 20 is provided so as to face the bowl portion 43, and projects light having a predetermined light projection amount toward the bowl portion 43. The light projected from the light projecting element 20 is reflected by the object to be detected 13 such as the bowl 43 or the user's hand, and the reflected light is received by the light receiving element 22. It is transmitted to the control unit 10.

FIG. 3 shows a general waveform when the object detection sensor 8 detects the detected object 13. The horizontal axis represents time, and the vertical axis represents the light reception level received by the light receiving element 22.
When the detected object 13 does not exist, the light reception level is stable near a stable level lower than the second threshold (water stoppage state). When the detected object 13 enters the detection area 12 of the object detection sensor 8, the light reception level increases, and when the light reception level becomes equal to or higher than the first threshold (timing t <b> 3), the control unit 10 determines that water discharge is started. Then, the signal is passed to the electromagnetic valve driving means 73, and the electromagnetic valve driving means 73 opens the water side electromagnetic valve 26 and the hot water side electromagnetic valve 82 to start the water discharge operation. In addition, the control part 10 is provided in the lower part of the washstand 1, and the object detection sensor 8, the water side electromagnetic valve 26, and the hot water side electromagnetic valve 82 are each wiring 56 which transmits an electrical signal, wiring 55 and a wiring 83.
In the period of T1 during which the detected object 13 is present, the light reception level varies greatly due to a hand washing operation or the like (continuation of the water discharge state), but when the detected object 13 retreats from the detection area 12 of the object detection sensor 8, the light reception level is increased. Return to stability level. When the light receiving level becomes less than the second threshold value (timing t4), the control unit 10 determines that the water discharge is finished, and the signal is passed to the electromagnetic valve driving means 73, and the magnetic valve driving means 73 is on the water side. The solenoid valve 26 and the hot water side solenoid valve 82 are driven to close and the water discharge operation is completed. That is, the period of T0 and T2 is the water stop state, and the period of T1 is the water discharge state, and the presence state of the detected object 13 in the detection area 12 of the object detection sensor 8 matches the water discharge state. In consideration of when the light reception level fluctuates due to noise or the like, the first threshold value is generally set to a value higher than the second threshold value.

FIG. 4 shows a waveform when steam is generated when the object detection sensor 8 detects the detected object 13. The horizontal axis represents time, and the vertical axis represents the light reception level received by the light receiving element 22.
During the period of T10, the water discharge start timing (timing t14) is the same as the movement described in FIG. During the period of T11 in which the detected object 13 exists, the light reception level varies greatly due to a hand washing operation or the like (continuation of the water discharge state). Even when the detected object 13 moves away from the detection area 12 of the object detection sensor 8 (timing t15), when steam is generated, the projected infrared light is irregularly reflected and the light reception level does not return to the stable level. At this time, if only the second threshold value is set, the water discharge is continued until the light receiving level becomes less than the second threshold value (the water discharge state during the period T12 and T13). However, when the control unit 10 separately provides the third threshold value and the state where the light reception level is less than the third threshold value continues for a certain time (T12 period), the detected object 13 does not exist and the current light reception level state Since it is due to the influence of steam, it is possible to terminate the water discharge even when steam is generated by determining the end of water discharge. Alternatively, when the current light receiving level is lower than the third threshold value, the difference between the current light receiving level and the third threshold value is integrated, and when the value reaches a certain value, it may be determined that the water discharge has ended. With this process, the periods T10 and T13 are in the water-stopped state, the periods T11 and T12 are in the water-discharge state, and the presence state of the detected object 13 in the detection area 12 of the object detection sensor 8 can match the water-discharge state.

  The third threshold is preferably higher than the second threshold and lower than the first threshold. This is because if the third threshold is set to a value higher than the first threshold, even if the control unit 10 determines that the water stop has ended with the third threshold, immediately after that, it is determined that the water discharge starts with the first threshold. This is because the meaning of providing the third threshold value is lost.

  FIG. 5 shows a waveform when the object detection sensor 8 detects the object to be detected 13 and the object to be detected 13 moves farther to the detection area 12 of the object detection sensor 8 over time. The horizontal axis represents time, and the vertical axis represents the light reception level received by the light receiving element 22. At this time, the waveform is almost the same regardless of the presence or absence of steam.

  During the period T20, the water discharge start timing (timing t24) is the same as the movement described in FIG. During the period T21 in which the detected object 13 exists, the light receiving level varies greatly due to a hand washing operation or the like. When the detected object 13 is far away from the detection area 12 of the object detection sensor 8 (timing t25), the light receiving level is less than the third threshold value, and it is determined that the water discharge has ended when the detection period 13 continues for a certain period (T22 period). Will end up. In the case of steam as in the period T12 in FIG. 4, the change in the light reception level is small, but in the case where the detected object 13 is a hand as in the period T22 in FIG. 5, the change in the signal is large.

FIG. 6 shows a waveform when the object detection sensor 8 detects the detected object 13 and the detected object 13 moves farther to the detection area 12 of the object detection sensor 8 over time. The horizontal axis represents time, and the vertical axis represents the amount of change in the received light level received by the light receiving element 22. At this time, the waveform is almost the same regardless of the presence or absence of steam.
The amount of change in the received light level can be represented by a value such as a standard deviation or variance calculated from the received light level sampling data for a certain period. Symbols such as T20 and t24 are linked to FIG.

  Since the light reception level is stable during the period T20, the amount of change in the light reception level is also stable. When the detected object 13 enters the detection area 12 of the object detection sensor 8, the light reception level increases, and the amount of change in the light reception level also increases steeply (timing t24). In the period T21 in which the detected object 13 is present, the light reception level varies due to a hand washing operation or the like, and therefore, the amount of change in the light reception level continues to be higher than the period T20. When the detected object 13 is far away from the detection area 12 of the object detection sensor 8 (timing 25), the light reception level changes greatly, so the amount of change in the light reception level also increases. In the period of T22 and T23, since the detected object 13 still exists, the light reception level varies while securing a certain amount of value. Therefore, the amount of change in the light reception level continues to be higher than the period T20.

Therefore, the control unit 10 sets a first change amount that is larger than the change amount of the light reception level in the period T20 and smaller than the change amount of the light reception level in the periods T22 and T23, and the change amount of the light reception level is the first change amount. Is greater than the third threshold value, the water discharge is continued during the periods T22 and T23 in which the detected object 13 exists by stopping the determination that the water discharge ends when the state below the third threshold has elapsed for a certain period of time. be able to. Even if the amount of change in the light reception level is smaller than the first amount of change, a delay time may be provided so as to stop the water discharge end determination using the third threshold for a certain period of time. When the detected object 13 finally moves away from the detection area 12 of the object detection sensor 8, the control unit 10 determines that the water discharge has ended based on the second threshold value or the third threshold value.
With this process, the period T20 is in the water-stopped state, and the periods T21, T22, and T23 are in the water-discharged state, and the presence state of the detected object 13 in the detection area 12 of the object detection sensor 8 can be matched with the water-discharged state.

FIG. 7 is a flowchart of the water discharge end determination using the second threshold value, the third threshold value, and the first change amount in the water discharge state. The flow of the flowchart of FIG. 7 will be described.
It is determined whether the light reception level is smaller than the second threshold (S700). If the light reception level is smaller than the second threshold (Yes in S700), steam is not generated, and it is determined that the detected object 13 has retreated from the detection area 12 of the object detection sensor 8, and water discharge ends. (S704). If the light reception level is equal to or higher than the second threshold (No in S700), the amount of change in the light reception level is compared with the first amount of change (S701). When the amount of change in the received light level is equal to or greater than the first amount of change (Yes in S701), it is determined that the detected object 13 is present and water discharge is continued (S703). When the change amount of the light reception level is less than the first change amount (No in S701), it is compared whether or not a certain time has passed in a state where the light reception level is smaller than the third threshold value (S702). If a state in which the light reception level is smaller than the third threshold has elapsed for a certain time (Yes in S702), it is determined that the detected object 13 does not exist and the light reception level is increased due to steam, and the discharge ends. (S704). If the light reception level is smaller than the third threshold and a certain time has not elapsed (No in S702), it is determined that the detected object 13 still exists and water discharge is continued (S703).
By such processing, even if steam is generated, the presence state of the detected object 13 in the detection area 12 of the object detection sensor 8 and the water discharge state can be matched.

(Second Embodiment)
From here, the second embodiment (water discharge start determination) will be described. Also in the second embodiment, a schematic diagram illustrating an automatic faucet and a block diagram illustrating an automatic faucet are the same as those in FIGS.

FIG. 8 is a waveform in the water stop state after it is determined that the water stop has been completed with the third threshold value. The horizontal axis represents time, and the vertical axis represents the light reception level received by the light receiving element 22.
Since steam is generated during the period T30, the light receiving level is higher than the stable level when steam is not generated. At this time, the level of light reception exceeds the first threshold, which is the condition for starting water discharge, due to fluctuations in steam and the like, and there is a risk of erroneous water discharge. Therefore, the controller 10 separately provides a sixth threshold value that is higher than the first threshold value, which is the condition for starting water discharge, and temporarily determines the start of water discharge using the sixth threshold value. Water discharge can be prevented. However, if the determination of the start of water discharge is continued with the sixth threshold, the detection area 12 of the object detection sensor 8 becomes narrow, and the user's usability deteriorates. Therefore, the control unit 10 separately provides a first threshold value and a fifth threshold value that is lower than the third threshold value.

  Normally, in the water stop state, steam disappears with time, so the light receiving level decreases toward a stable level (period T30). At this time, it is determined that steam has disappeared by continuing the state where the light reception level is less than the fifth threshold for a certain period (T31 period), and the determination of the start of water discharge determined by the sixth threshold is the first threshold. (The discharge threshold value is returned to the first threshold value at timing t35). When the light receiving level exceeds the first threshold after timing t35 (timing t36), the water discharge state is entered.

  Such treatment can prevent erroneous water discharge due to steam without deteriorating usability. That is, the period of T30 and T31 is a water stop state, and the threshold value for determining the start of water discharge is the sixth threshold value. The period of T32 is a water stop state, and the threshold value for water discharge start determination is the first threshold value. During the period of T33, the water discharge state is set, and the threshold value for determining the start of water discharge is the first threshold value. If both prevention of erroneous water discharge and usability are compatible, the fifth threshold is preferably set to a value higher than the stability level and lower than the first threshold and the third threshold. However, emphasis is placed on prevention of erroneous water discharge. If it is set, the fifth threshold value is 0, the T31 period is infinite, and substantially until the light reception level exceeds the sixth threshold value (until it is determined that water discharge has started once), the threshold value for the water discharge start determination value is set to sixth. The threshold value may be fixed.

  Further, the determination of the disappearance of steam (determination of whether the threshold value for starting water discharge is set to the first threshold value or the sixth threshold value) is the same as the current received light level when the current received light level is less than the fifth threshold value. The difference from the threshold value of 5 may be integrated and the value may reach a certain value.

  FIG. 9 is a waveform in the water stop state after it is determined that the water stop has been completed with the third threshold value. The horizontal axis represents time, and the vertical axis represents the amount of change in the received light level received by the light receiving element 22. The amount of change in the received light level can be represented by a value such as a standard deviation or variance calculated from the received light level sampling data for a certain period. Symbols such as T30 and t34 are linked to FIG.

  The period of T30 and T31 is a state where steam is generated, but the level gradually decreases. Therefore, the amount of change in the received light level is a low value and a substantially constant value. Subsequently, when the detected object 13 enters the detection area 12 of the object detection sensor 8 during the period T32, the light reception level increases, and the amount of change in the light reception level increases sharply. Since the hand-washing operation is performed during the period T33, the amount of change in the received light level changes to a certain high value.

  Therefore, the control unit 10 provides the second change amount, and determines the start of water discharge when the change amount of the received light level exceeds the second change amount, thereby distinguishing steam from the presence of the detected object 13 and steam. It is possible to prevent erroneous water discharge. The second change amount is larger than the change amount of the light reception level due to the fluctuation of steam, and is smaller than the change amount of the light reception level caused when the detected object 13 enters the detection area 12 of the object detection sensor 8. It is desirable to do. Incidentally, since the amount of change in the light reception level shows a large value even when the detected object 13 goes out of the detection area 12 of the object detection sensor 8, the light reception level is changed before the determination based on the second amount of change. However, a condition may be added that indicates that the detected object 13 can be determined to be within the detection area 12 of the object detection sensor 8.

Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.
For example, as described with reference to FIG. 8, setting the threshold value for determining water discharge to the sixth threshold value until the state where the light reception level is less than the fifth threshold value continues for a certain period of time is a temporary object detection. This means that the detection area 12 of the sensor 8 is narrowed. On the other hand, in the method of checking the amount of change in the light reception level as described with reference to FIG. 9, when the detected object 13 slowly approaches the detection area 12 of the object detection sensor 8, the change in the light reception level. There is a possibility that the amount does not exceed the second change amount and is not determined to be the start of water discharge.

  However, when these two are combined, if the detected object 13 exists far from the detection area 12 of the object detection sensor 8, it can be determined that water discharge starts with the second change amount. When the water approaches slowly, it can be determined that the water discharge starts based on the first threshold value or the sixth threshold value, so that it is possible to prevent the water discharge start due to the steam without deteriorating the usability at all. it can.

  In the first embodiment, the third threshold value cannot be set higher than the first threshold value. However, by using the second embodiment, the third threshold value is set higher than the first threshold value. Even if it is set, it can be determined that water discharge is not mistaken.

  When the water discharge start determination using the first threshold value, the fifth threshold value, the sixth threshold value, and the second change amount in the water stop state after determining that the water discharge is finished at the third threshold value is summarized in FIG. It becomes a flowchart like this. The flow of the flowchart of FIG. 10 will be described.

  It is compared whether a certain time has passed in a state where the light reception level is lower than the fifth threshold (S1000). If a state in which the light reception level is smaller than the fifth threshold has elapsed for a certain time (Yes in S1000), it is determined that there is no influence of steam, and the threshold for determining water discharge is set as the first threshold (S1001). If a state where the light reception level is lower than the fifth threshold has not passed for a certain period of time (No in S1000), there is still concern about the influence of steam, so the threshold for determining water discharge is set as the sixth threshold (S1002).

  Subsequently, the received light level is compared with the threshold value for determining the start of water discharge (S1003). At this time, the first threshold value or the sixth threshold value is set as the threshold value for determining water discharge start. If the received light level is equal to or higher than the threshold value for determining the start of water discharge (Yes in S1003), it is determined that the detected object 13 is present in the detection area 12 of the object detection sensor 8 (is at a close distance) and water discharge is started (S1006). ). If the received light level is less than the threshold value for determining water discharge start (No in S1003), the process proceeds to the next process (S1004).

  Subsequently, the amount of change in the received light level is compared with the second amount of change (S1004). If the amount of change in the received light level is equal to or greater than the second amount of change (Yes in S1004), it is determined that the detected object 13 has moved into the detection area 12 of the object detection sensor 8, and water discharge is started (S1006). Judge. If the amount of change in the received light level is less than the second amount of change (No in S1004), it is determined that the water stop is continued (S1005).

  By this process, even if steam is generated, it is possible to prevent the steam from being erroneously determined to start discharging without deteriorating the usability.

DESCRIPTION OF SYMBOLS 1 ... Wash-stand 2 ... Automatic faucet 4 ... Water faucet body 8 ... Object detection sensor 10 ... Control part 11 ... Memory 12 ... Detection area of the object detection sensor 8 13 ... Object to be detected 20 ... Projection element (transmission part)
22. Light receiving element (receiver)
DESCRIPTION OF SYMBOLS 26 ... Water side solenoid valve 28 ... Water supply source 30 ... Water discharge port 43 ... Bowl part 52 ... Water supply hose 53 ... Water supply hose 55 ... Wiring 56 ... Wiring 60 ... Single lever type hot / cold water mixing tap 73 ... Solenoid valve drive means 80 ... Hot water supply Source 81 ... Water supply hose 82 ... Hot water side solenoid valve 83 ... Wiring 85 ... Water supply hose 86 ... Water supply hose

Claims (6)

A spout for discharging hot water supplied from a water supply path;
A solenoid valve connected to the water supply path;
A sensor that transmits a propagating wave and detects its reflection amount;
A controller that determines that the water discharge is started when the reflection amount of the propagating wave is greater than or equal to a first threshold, and determines that the water discharge is ended when the value is less than a second threshold smaller than the first threshold;
An electromagnetic valve driving means for driving the electromagnetic valve based on the judgment output of the control unit;
In automatic faucet equipped with
When the amount of reflection of the propagating wave exceeds the first threshold and the water is being discharged, the control unit is configured to reflect the amount of propagating wave even if the amount of reflection of the propagating wave is greater than or equal to the second threshold. If it is determined that the amount of reflection is due to the influence of steam, it is determined that the water discharge has ended. The control unit provides a third threshold value that is larger than the second threshold value and smaller than the first threshold value, and the amount of reflection of the propagating wave is greater than or equal to the second threshold value, and the third threshold value. The automatic water faucet according to claim 1, wherein the water faucet is judged to be the end of water discharge when the value is less than a predetermined time. The control unit, when the amount of change in the reflection amount of the propagating wave is equal to or greater than the first change amount, stops determining that the water discharge has ended by the third threshold value. Automatic faucet as described. The controller determines that the water discharge has started on the basis of a determination criterion greater than the first threshold after determining that the water discharge has ended because the amount of reflection of the propagation wave is a reflection amount due to the influence of steam. The automatic water tap according to claim 2 or claim 3. When the control unit determines that the water discharge is ended by the third threshold value, the control unit sets a first threshold value and a fifth threshold value that is smaller than the third threshold value and larger than the second threshold value, A sixth threshold value that is larger than the first threshold value is provided until the propagation wave reflection amount is less than the fifth threshold value for a certain period of time, and it is determined that water discharge starts at the sixth threshold value. The automatic faucet according to claim 4, wherein: When the control unit determines that the water discharge is ended based on the third threshold value, the control unit determines that the water discharge starts when the amount of change in the reflected wave reflection amount is equal to or greater than the second change amount. The automatic faucet according to claim 4.