JP2012226909A - Human body detection sensor and automatic faucet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a human body detection sensor which has both detection performance and energy-saving performance.SOLUTION: A human body detection sensor 1 which detects a detection object by receiving reflected light generated according to light emitted by a light emission part 25, by an imaging part 26 includes: imaging control means 311 for controlling light emission operation by the light emission part 25 and light reception operation by the imaging part 26; first determination means 321 for determining whether a temporal variation amount of the light reception amount of a specific pixel of a line sensor 261 having received the reflected light is equal to or larger than a predetermined threshold; and second determination means 322 for determining whether there is the detection object according to the position of incidence of the reflected light on the line sensor 261 when the first determination means makes an affirmative determination.

Description

  The present invention relates to a human body detection sensor applied to an automatic faucet, an automatic cleaning device for a urinal, and the like.

  Conventionally, automatic faucets that automatically discharge water when a user's hand-holding operation is detected, and automatic cleaning devices for urinals that automatically supply cleaning water when a user is approaching An applied human body detection sensor is known. As such a human body detection sensor, a sensor in which a light emitting element such as an LED and a light receiving element such as a PSD (Position Sensitive Detector) are offset and arranged is known.

  This human body detection sensor specifies the position where reflected light from the detection target is incident on the PSD, and measures the distance to the detection target based on the principle of triangulation. The PSD is a very simple light receiving element that outputs a signal corresponding to the position of the center of gravity of incident light, and has an advantage of low power consumption. On the other hand, information that can be acquired by PSD is only position information, and there is a fact that there are few countermeasures that can be taken when ambient light is incident. Therefore, for example, when a human body detection sensor including a PSD is applied to an automatic faucet of a washstand, erroneous detection may occur due to the influence of ambient light such as specular reflected light from a wash bowl.

  In order to suppress the influence of ambient light and improve detection performance, a human body detection sensor using an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) has been proposed (for example, Patent Document 1). reference.). If it is a human body detection sensor using an image sensor, for example, it is possible to eliminate the influence of disturbance light by utilizing distribution information of the received light amount for each pixel and improve the detection performance.

  However, the human body detection sensor using the conventional image sensor has the following problems. That is, if an image sensor is used, there is a possibility that false detection can be suppressed. On the other hand, a human body detection sensor that uses an image sensor that consumes more power than a simple light receiving element such as a PSD increases power consumption and saves energy. May be damaged.

JP 2005-207012 A

  The present invention has been made in view of the above-described conventional problems, and realizes improved detection performance by adopting an image sensor such as a CCD or a CMOS, and has excellent energy saving performance while suppressing an increase in power consumption. It is an object of the present invention to provide a human body detection sensor and an automatic water faucet that realize the above.

A first aspect of the present invention includes an imaging unit including an imaging element in which pixels are arranged one-dimensionally or two-dimensionally, and a light-emitting unit that is disposed offset in a predetermined direction with respect to the imaging unit, A human body detection sensor for detecting a detection target by receiving reflected light generated by the light emitting unit according to light projected by the imaging unit,
Imaging control means for controlling the light emitting operation by the light emitting unit and the light receiving operation by the imaging unit;
Reading means for reading the amount of light received by each pixel of the image sensor in accordance with the light receiving operation;
First determination means for determining whether or not a temporal change amount of a light reception amount of a specific pixel of the image sensor that has received the reflected light is equal to or greater than a predetermined threshold;
When the first determination means makes a positive determination, the incident position of the reflected light in a light receiving area that is an array area of each pixel in the image sensor is specified, and the detection target is detected according to the incident position. Second determination means for determining presence or absence;
And a detection output means for outputting a detection signal when the second determination means determines that there is an object to be detected.

The second aspect of the present invention is a faucet that discharges water into a bowl provided with a drain outlet at the bottom;
The human body detection sensor of the first aspect;
In response to a detection signal of the human body detection sensor, the water supply control means for switching the water stoppage of the faucet or adjusting the water discharge amount,
The imaging range of the imaging unit included in the human body detection sensor is in an automatic faucet including the inner peripheral surface of the bowl.

  The human body detection sensor according to the first aspect of the present invention includes two types of determination means. The first determination means is means for determining a temporal change in the amount of light received by the specific pixel. The second determination unit is a unit that determines the presence or absence of the detection target based on the incident position of the reflected light with respect to the imaging element. In this human body detection sensor, the determination by the second determination means is not always executed. The determination by the second determination unit is executed only when the first determination unit determines that the temporal change amount is equal to or greater than a predetermined threshold.

  If the number of executions of the second determination means including the process of specifying the incident position of the reflected light can be reduced, the calculation load of the human body detection sensor can be reduced and the light receiving operation necessary for the determination can be omitted. Thus, if the calculation load and the number of executions of the light receiving operation can be reduced, the power consumption of the human body detection sensor can be efficiently suppressed. In particular, when the human body detection sensor is applied to an automatic faucet such as a wash basin or a kitchen, only the determination by the first determination means is performed in most of the non-operation period in which the hand-holding operation is not performed. Doing so will improve your power consumption.

  On the other hand, when applied to a washstand, specular reflected light from the bowl surface may be incident on the image sensor. In particular, in the automatic faucet according to the second aspect of the present invention, the bowl surface is included in at least a part of the imaging range imaged by the imaging element. For this reason, when there is no target to be detected such as a palm or back of the hand in the imaging range, there is a high possibility that the specular reflected light from the bowl surface is incident on the imaging element without being blocked.

While such specularly reflected light is incident, there is a possibility that an erroneous determination of the second determination unit may be induced. On the other hand, since the temporal change in the amount of light received by each pixel is small, the negative determination is made by the first determination unit. There is a high possibility that a general determination will be made. If a negative determination is made by the first determination means, the execution of the second determination means can be avoided in advance, and erroneous detection induced due to an erroneous determination of the second determination means can be avoided. .
On the other hand, if there is a detection target such as a palm or the back of the hand in the imaging range, the possibility of disturbance light such as specular reflection light entering the imaging element is reduced. In such a situation, the determination accuracy by the second determination means is ensured to be high, and highly accurate detection by the human body detection sensor can be realized.

  As described above, the human body detection sensor of the present invention and the automatic faucet provided with the human body detection sensor have excellent characteristics in which detection performance and energy saving performance are compatible.

  The specific pixel to be determined by the first determination unit in the present invention may be any one pixel, or may be a plurality of pixels belonging to any one range, separated from each other. It may be a plurality of pixels, may be a pixel belonging to a plurality of locations separated from each other, or may be all the pixels of the image sensor. Further, if there are a plurality of the specific pixels, threshold processing may be performed for the change in the total amount of light received by each pixel, and threshold processing may be performed individually for the change in the amount of light received by each pixel, exceeding the threshold. It is also possible to determine whether there is a temporal change in the amount of received light based on the number of pixels.

  The incident position of the reflected light may be the center of gravity position of the reflected light incident on the light receiving area, and the position of the pixel where the amount of received light is maximized or the position where the sum of the amounts of received light of surrounding pixels is maximized. Etc. Further, as long as it is a center of gravity position, it may be a center of gravity position that is mathematically calculated strictly, or may be a center of gravity position that can be easily calculated while ensuring the required accuracy.

In addition, as a method of determining the presence / absence of the detection target according to the incident position, the second determination unit calculates the distance corresponding to the incident position using the principle of triangulation, for example, A method for determining whether the calculated distance is suitable for the target detection distance or a detection area corresponding to the detection distance is set in the light receiving area, and the incident position is set in the detection area. There is a method of determining according to whether or not the user belongs.
The adjustment of the water discharge amount in the automatic faucet includes adjustment of water discharge start, water discharge stop, and increase / decrease of the water discharge amount.

In addition, the second determination unit obtains, for each pixel, a difference in received light amount between the received light amount when the light emitting unit projects light and the received light amount when there is no light projection by the light emitting unit, It is preferable to specify the incident position with respect to the difference in received light amount of each pixel.
By subtracting the received light amount of only the ambient light from the received light amount with the projection light by the light emitting unit in addition to the ambient light, the influence of the ambient light can be suppressed and the reflected light component corresponding to the projected light can be extracted with high accuracy. As described above, based on the received light amount of the difference obtained by accurately extracting the component of the reflected light corresponding to the projection light, the incident position can be specified with high accuracy, and the detection accuracy can be improved.

In addition, the second determination unit corresponds to the light reception operation executed for the determination by the first determination unit as the amount of light received by each pixel of the image sensor when the light emitting unit projects light. It is preferable to use the received light amount of each pixel read out.
In this case, the number of executions of the light receiving operation by the imaging unit can be reduced, and power consumption can be effectively reduced.

The second determination unit calculates a total received light amount that is a sum of received light amounts of the pixels arranged in the predetermined direction in the imaging element, and
The pixel when the accumulated light reception amount obtained by sequentially integrating the light reception amounts of the respective pixels toward the other end from the pixel located at one end of the predetermined direction reaches half of the total light reception amount Is preferably specified as the incident position.

  Such an incident position is a position that can be approximated as the position of the center of gravity of the reflected light. In general, if the position of the center of gravity of the reflected light is to be calculated strictly, multiplication of the received light amount of each pixel and the distance (from the position of the center of gravity) or the like is required, and the calculation processing load may become excessive. On the other hand, according to the simple calculation method as described above, the calculation load can be remarkably reduced while ensuring the position accuracy of the incident position calculated as the position of the center of gravity.

The perspective sectional view showing the washstand provided with the automatic faucet in the example. Sectional drawing which shows the cross-section of a sensor unit in an Example (AA sectional view taken on the line AA in FIG. 1). The perspective view which shows the line sensor in an Example. The block diagram which shows the system configuration | structure of the human body detection sensor in an Example. The flowchart which shows the flow of a detection process in an Example. The flowchart which shows the flow of the simple determination process in an Example. The flowchart which shows the flow of the detailed determination process in an Example. Explanatory drawing which shows the production | generation procedure of difference data in an Example. Explanatory drawing explaining the calculation method of the gravity center position in an Example. Explanatory drawing explaining the detection principle in an Example.

The embodiment of the present invention will be specifically described with reference to the following examples.
(Example)
In this example, the human body detection sensor 1 is applied to the faucet (automatic faucet) 16 of the washstand 15. The contents will be described with reference to FIGS.
As shown in FIG. 1, the washstand 15 of this example includes a counter 155 provided with a bowl portion 151 that is recessed in a concave shape, and a faucet 16 having a water discharge port 168. The faucet 16 is erected on a counter top 156 that forms the upper surface of the counter 155. The bowl portion 151 has a drain port 152 at its deepest portion.

  The faucet 16 has a base portion 161 that forms a pedestal with respect to the countertop 156, and a substantially cylindrical body portion 160 that extends from the base portion 161. The body part 160 is supported by the base part 161 in a state where it is inclined toward the bowl part 151 side. A substantially cylindrical water discharge portion 162 having a water discharge port 168 opened at the tip is attached to the side surface of the body portion 160 that contacts the bowl portion 151 side. A filter plate 165 that forms a detection surface of the human body detection sensor 1 is disposed on a side surface of the body portion 160 that is an upper side of the water discharge portion 162. The filter plate 165 is a resin filter that selectively transmits light in the infrared region.

  As shown in FIGS. 1 and 2, the human body detection sensor 1 of this example includes a sensor unit 2 incorporated in a faucet 16 and a control unit 3 that controls the sensor unit 2. In the wash basin 15, an automatic water supply device is formed by a combination of the human body detection sensor 1 and a solenoid (water supply control means) 11 that is a water discharge valve (electromagnetic valve) provided in the water supply pipe 12.

  As shown in FIGS. 1 and 2, the sensor unit 2 is a unit in which the LED element 251 and the line sensor (imaging element) 261 are housed in the housing 21, and operates by receiving power supply from the control unit 3. In the sensor unit 2, the light emitting unit 25 and the imaging unit 26 are disposed so as to look at the filter plate 165 of the faucet 16. The light emitting unit 25 that emits infrared light includes an LED element 251 and a light projecting lens 255. The imaging unit 26 includes a line sensor 261 and a condenser lens 265. The light emitting unit 25 and the imaging unit 26 are arranged with a predetermined offset amount in the horizontal direction across the partition wall 211 having a light shielding property.

  As shown in FIG. 2, the LED element 251 is a light emitting element in which the LED chip 250 mounted in the cavity of the package substrate is sealed with a transparent resin 254. In the light emitting unit 25, the LED element 251 is covered with a light-shielding element case 252 provided with a longitudinal slit hole 253. According to the light emitting unit 25, it is possible to project sharp light with a suppressed divergence angle toward a detection target.

  As shown in FIGS. 1 to 3, the line sensor 261 is a one-dimensional imaging sensor in which pixels 260 that convert a received light amount into an electrical physical amount are linearly arranged. The line sensor 261 includes 64 pixels 260 as effective pixels. In the line sensor 261, a light receiving area 263 is formed by these 64 pixels 260. In this example, the line sensor 261 is disposed so as to look at the bowl surface 150 of the bowl portion 151. If there is no obstacle such as a hand in the expected direction of the line sensor 261, the bowl surface 150 is included in the imaging range.

  The line sensor 261 outputs imaging data every time a light receiving operation is executed. The imaging data in this example is one-dimensional digital data in which pixel values of 256 gradations corresponding to the amount of received light are arranged in the order in which the pixels 260 are arranged. The line sensor 261 of this example includes an electronic shutter (not shown). If the exposure time is adjusted using an electronic shutter, saturation of the amount of light received by each pixel 260 can be avoided in advance.

  As shown in FIGS. 1 and 4, the control unit 3 is a unit that controls the sensor unit 2 and the solenoid 11, and operates by receiving power from a commercial power source. The control unit 3 includes a control board 30 that controls the sensor unit 2 and the solenoid 11. The control board 30 is provided with an imaging control unit 31 that controls the line sensor 261 and the LED element 251, a detection processing unit 32 that executes detection processing, and a water supply control unit 33 that controls the solenoid 11.

The imaging control unit 31 has functions as an imaging control unit 311 that controls the LED element 251 and the line sensor 261 and a reading unit 312 that reads imaging data from the line sensor 261.
The imaging control unit 311 controls the line sensor 261 so that an intermittent operation in which an operation period and a non-operation period appear alternately is performed. The imaging control means 311 stops supplying power to the line sensor 261 until a predetermined interval time (in this example, about 0.3 to 0.5 seconds) has elapsed since the end of the previous operation period. A non-operation period is set, and when the interval time elapses, the power supply is resumed to set the operation period.

  The detection processing unit 32 has functions as first and second determination units 321 and 322 that are detection processing execution units, and a detection output unit 325 that outputs a detection signal in response to detection. In the following description, a rough flow of detection processing by the detection processing unit 32 will be described with reference to FIG. 5, and then simple determination processing (FIG. 6) and detailed determination processing by the first and second determination means 321 and 322. The contents of (FIG. 7) will be described.

  In the detection process of FIG. 5, first, simple determination by the first determination unit 321 is executed (S101). When an affirmative determination is made by the simple determination (S102: YES), a detailed determination by the second determination means is executed (S103). When a positive determination is also made in the detailed determination (S104: YES), detection is determined (S105), and a detection signal is output.

  On the other hand, when a negative determination is made in the simple determination in step S101 or the detailed determination in step S103 (S102: NO, S104: NO), the operation period is ended and the operation proceeds to the non-operation period. An operating period is awaited. In particular, when a negative determination is made in the simple determination in step S101 (S102: NO), the detailed determination in step S103 is not executed, and the operation period is ended as it is.

  The first determination unit 321 is a simple determination execution unit in step S101 in FIG. The flow of the simple determination process by the first determination means 321 is as shown in the flowchart of FIG. In the simple determination process, first, light emission data L (x) that is imaging data under LED light (projection light of the LED element 251) is captured (S201). Here, x represents a pixel number of 0 to 63, and L (x) represents a pixel value (light reception amount) of the pixel 260 of the image number x.

  For this light emission data L (x), the sum S0 of the pixel values of all the pixels (specific pixels) 260 is obtained (S202). Further, the sum S1 (previous value) of the pixel values calculated in step S202 of the simple determination process for the previous operation period is read (S203). Then, | S0−S1 | (the absolute value of the difference between S0 and S1) is compared with the threshold value X (S204). If | S0−S1 |> X (S204: YES), simple determination is performed. In step S205, a positive determination is made.

  On the other hand, if | S0−S1 | ≦ X (S204: NO), the total sum S0 calculated in step S202 is stored as the previous value S1 (S215), and a negative determination is made by simple determination (S215). S216). As described above, when a negative determination is made in the simple determination, the operation period ends and the operation period shifts to the non-operation period, and the capture of the light emission data L (x) in the next operation period is awaited. The

  The second determination unit 322 is a detailed determination execution unit in step S103 in FIG. The detailed determination processing flow by the second determination means 322 will be described with reference to the flowchart of FIG. 7 with reference to FIGS. 8 to 10 as appropriate. As described above with reference to FIG. 5, the detailed determination process is started when a positive determination is made by the simple determination.

  In the detailed determination process, first, data C (x) when no light is emitted, which is imaging data under no light emission of the light emitting unit 25, is captured (S301). Then, the difference data D (x) is calculated by subtracting the non-light emission data C (x) from the light emission data L (x) captured in step S201 (FIG. 6) of the simple determination process (S302). . In the difference data D (x) obtained by subtracting the non-light emitting data C (x) of only the ambient light from the light emitting data L (x) with the LED light in addition to the ambient light, as shown in FIG. The influence is suppressed, and the component of reflected light corresponding to the LED light is extracted.

  In the subsequent step S303, the gravity center position (incident position) is calculated for the difference data D (x). Here, in this example, the center of gravity position is calculated by a simple calculation method in order to reduce the calculation load. This calculation method will be described with reference to FIG. 9 in which the horizontal axis represents the pixel number x and the vertical axis represents the pixel value (light reception amount) D (x).

  In the calculation method of this example, first, the difference data D (x) is integrated to obtain the sum SD of the pixel values of 64 pixels. This total SD corresponds to the area of the region indicated by hatching in the upward direction in FIG. The barycentric position is obtained by integrating the pixel values of the respective pixels 260 in order from the pixel of the pixel number zero at the left end of the light receiving area 263, and the pixel number N when the integrated value reaches SD / 2 (with a black circle) Calculated). Here, the integrated value SD / 2 corresponds to the area of a region indicated by hatching with a downward slope to the right. This region is included in the region of the total sum SD, and is grasped as a cross hatch region in FIG.

  In subsequent step S304, it is determined whether or not the position of the center of gravity calculated as described above is located in the detection area (see FIG. 9) in the light receiving area 263. In this example, based on the principle of triangulation by the sensor unit 2, the detection area is set as described below.

  The positional relationship between the sensor unit 2, the bowl surface 150 of the bowl 151, and the user's hand in the wash basin 15 of this example can be schematically expressed as shown in FIG. When the component of the reflected light of the LED light by the hand that is the detection target is incident on the line sensor 261, the incident position differs depending on the distance H to the detection target. As the distance H is shorter, the incident position with respect to the line sensor 261 is on the left side in the figure, and as the distance H is longer, it is located on the right side. Based on the incident position of the reflected light with respect to the line sensor 261, it is also possible to measure the distance of the detection target. The detection area in step S304 is an area set in the light receiving area 263 so as to correspond to the detection distance to be detected. By determining whether or not the position of the center of gravity is within the detection area as in step S304, it is possible to determine the presence or absence of a detection target such as a hand inserted within the detection distance of FIG.

  If it is determined in step S304 that the position of the center of gravity is located in the detection area and there is a detection target at the detection distance in FIG. 10 (S304: YES), a positive determination is made (S305), and step S105 in FIG. A detection signal is output as shown in FIG. On the other hand, when it is determined that the position of the center of gravity is outside the detection area (S304: NO), it is not detected and the operation period is shifted to the next operation period (S315).

  As described above, in the human body detection sensor 1 of this example, the detection is realized through the two-stage determination of the simple determination and the detailed determination. In the detection process by the human body detection sensor 1, it is not necessary to execute the detailed determination process (FIG. 7) with a relatively high calculation load every time, and it may be executed only when an affirmative determination is made by a simple determination. In most operation periods of the human body detection sensor 1, only simple determination is performed, and detailed determination is executed only when a hand-holding operation is actually performed. Thereby, the calculation load and the number of execution times of the light receiving operation are remarkably reduced, and the power consumption is drastically reduced.

  When specular reflection light from the bowl surface 150 acts on the human body detection sensor 1, in the detailed determination based on the center of gravity position of the specular reflection light, an erroneous determination may occur as in the conventional sensor. On the other hand, since the temporal change in the amount of light received by each pixel 260 is small during the incidence of specular reflection light, there is a high possibility that a negative determination can be derived if it is a simple determination. If a negative determination result can be obtained by simple determination, execution of detailed determination for specular reflected light can be avoided in advance. Thereby, in the human body detection sensor 1 of this example, the vicious circle of generation | occurrence | production of specular reflection light-> incorrect determination by detailed determination-> erroneous detection-> malfunction of a faucet is avoided beforehand, and detection performance is improved.

Thus, the human body detection sensor 1 of this example is a sensor having excellent characteristics in which detection performance and energy saving performance are compatible. The automatic faucet 16 provided with the human body detection sensor 1 is an excellent product with few malfunctions and high energy saving performance.
Further, in the human body detection sensor 1 of this example, the light emission data L (x) is shared between the simple determination process and the detailed determination process. Thereby, the number of executions of the light receiving operation of the line sensor 261 is further reduced.

In this example, the detailed determination process is executed only once when an affirmative determination is made in the simple determination. Instead of this, the detailed determination process may be executed continuously a plurality of times. In this case, it is preferable to suppress the detection omission by executing the detailed determination based on the strict determination criterion a plurality of times while suppressing the erroneous detection by setting the determination criterion of the detailed determination each time.
In addition, when each pixel 260 of the line sensor 261 has a variation in sensitivity, the detection process may be executed after correcting the pixel value of each pixel 260.

In this example, an electronic shutter is employed to control the length of exposure time during the light receiving operation. Although an electronic shutter is not essential and can be omitted, a mechanical shutter that physically blocks light incident on the line sensor 261 may be employed instead of the electronic shutter.
In this example, the center of gravity position is calculated by simple calculation, but the center of gravity position may be calculated mathematically strictly if there is a margin in calculation processing capability.

  In addition, although this example is an example in which the human body detection sensor 1 is applied to the washstand 15, it may be a kitchen faucet. Furthermore, it is also possible to apply the human body detection sensor 1 of this example as a sensor of an automatic water supply device for a toilet bowl with an automatic cleaning function. Furthermore, the human body detection sensor 1 of this example can also be applied to various automatic devices such as a hand-holding operation and lighting or automatic doors that automatically turn on in response to a human body.

In this example, the sensor unit 2 and the control unit 3 are configured separately. Instead of this, the sensor unit 2 and the control unit 3 may be configured integrally and accommodated in the faucet 16.
Moreover, although the human body detection sensor 1 of this example contains the water supply control part 33, the water supply control part 33 can also be comprised separately.

  As described above, specific examples of the present invention have been described in detail as in the embodiments. However, these specific examples merely disclose an example of the technology included in the scope of claims. Needless to say, the scope of the claims should not be construed as limited by the configuration, numerical values, or the like of the specific examples. The scope of the claims includes techniques obtained by variously modifying or changing the specific examples using known techniques, knowledge of those skilled in the art, and the like.

DESCRIPTION OF SYMBOLS 1 ... Human body detection sensor, 15 ... Wash-stand, 16 ... Water faucet (automatic water faucet), 11 ... Solenoid, 12 ... Water supply piping, 2 ... Sensor unit, 25 ... Light emission part, 251 ... LED element, 26 ... Imaging part, 260 ... Pixels, 261 ... Line sensor (imaging device), 263 ... Light receiving area, 3 ... Control unit, 30 ... Control board, 31 ... Imaging control unit, 311 ... Imaging control unit, 312 ... Reading unit, 32 ... Detection processing unit 321 ... First determination means, 322 ... Second determination means, 325 ... Detection output means, 33 ... Water supply control unit

Claims (5)

An imaging unit including an imaging device in which pixels are arranged one-dimensionally or two-dimensionally, and a light-emitting unit arranged offset in a predetermined direction with respect to the imaging unit, and according to light projected by the light-emitting unit A human body detection sensor that detects the detected object by receiving the reflected light generated by the imaging unit,
Imaging control means for controlling the light emitting operation by the light emitting unit and the light receiving operation by the imaging unit;
Reading means for reading the amount of light received by each pixel of the image sensor in accordance with the light receiving operation;
First determination means for determining whether or not a temporal change amount of a light reception amount of a specific pixel of the image sensor that has received the reflected light is equal to or greater than a predetermined threshold;
When the first determination means makes a positive determination, the incident position of the reflected light in a light receiving area that is an array area of each pixel in the image sensor is specified, and the detection target is detected according to the incident position. Second determination means for determining presence or absence;
A human body detection sensor comprising: a detection output unit configured to output a detection signal when the second determination unit determines that there is a detection target.   2. The second determination unit according to claim 1, wherein the second determination unit calculates a received light amount of a difference between a received light amount when the light emitting unit projects light and a received light amount when no light is projected by the light emitting unit for each pixel. A human body detection sensor that determines the incident position with respect to the received light amount of the difference of each pixel.   3. The light reception unit according to claim 2, wherein the second determination unit performs the light reception performed for the determination by the first determination unit as a light reception amount of each pixel of the image sensor when the light emitting unit projects light. A human body detection sensor that uses the amount of light received by each pixel read according to the operation. In any one of Claims 1-3, While the said 2nd determination means calculates the total light reception amount which is the sum total of the light reception amount of each pixel arranged in the said predetermined direction in the said image pick-up element,
The pixel when the accumulated light reception amount obtained by sequentially integrating the light reception amounts of the respective pixels toward the other end from the pixel located at one end of the predetermined direction reaches half of the total light reception amount The human body detection sensor which specifies the position of as the said incident position. A faucet that discharges water into a bowl with a drain at the bottom;
The human body detection sensor according to any one of claims 1 to 4,
In response to a detection signal of the human body detection sensor, the water supply control means for switching the water stoppage of the faucet or adjusting the water discharge amount,
An automatic faucet in which an inner peripheral surface of the bowl is included in an imaging range of an imaging unit included in the human body detection sensor.

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