JP5909171B2 - Human body detection sensor and automatic faucet - Google Patents

Description

  The present invention relates to a photoelectric human body detection sensor.

  Conventionally, automatic faucets that automatically detect the user's hand-holding operation and discharge water automatically, and automatic cleaning devices for urinals that automatically detect the approaching user and supply cleaning water are known. It has been. In these automatic faucets and automatic washing apparatuses, human body detection sensors for detecting a human body are used. As a human body detection sensor, a photoelectric sensor including a light emitting element and a light receiving element is generally used.

  As such a human body detection sensor, it includes a sensor that detects an object by detecting a movement by temporal change of reflected light according to light projection by a light emitting element, and a light receiving / light emitting element arranged in an offset manner, There are sensors that perform distance measurement using the principle of triangulation (for example, see Patent Document 1).

  A human body detection sensor that detects motion is suitable for detecting motion in a relatively wide range, and has an advantage of easily setting a wide detection range. On the other hand, in detection by this type of human body detection sensor, erroneous detection due to disturbance light that changes from time to time, such as light from a gap in a curtain swaying in the wind or a sunbeam, may occur.

  In a human body detection sensor that performs distance measurement, distance measurement is performed by specifying the incident position of reflected light in the offset direction of the light receiving / emitting element. If the distance to the object or the degree of distance is known, the object can be distinguished from the background object (for example, a bowl surface in the case of a washstand) by distance determination, and the detection accuracy can be improved. On the other hand, in order to accurately specify the incident position in the offset direction, it is necessary to project the slit-shaped or spot-shaped light in which the spread of the light in the offset direction is suppressed toward the object. In this type of human body detection sensor, if the detection accuracy is increased, the detection range tends to be narrowed.

  Combining the former human body detection sensor, which is easy to set with a wide detection range with a reasonable detection performance, and the latter human body detection sensor, whose detection accuracy is narrow but the detection range is narrow, complements both drawbacks. If the advantage can be utilized, there is a possibility that a human body detection sensor with high detection performance and high accuracy that can cover a wide range can be realized.

  However, a human body detection sensor that incorporates both an optical configuration suitable for motion detection and an optical configuration suitable for distance measurement may increase the cost and increase the size. For the built-in products, compact design may be difficult and the product cost may increase.

JP 2005-207012 A

  The present invention has been made in view of the above-described conventional problems, and is intended to provide a compact human body detection sensor that can easily ensure detection performance.

A first aspect of the present invention is a photoelectric human body detection sensor including a light emitting unit and a light receiving unit,
A first light emitting unit that is arranged offset from the light receiving unit and projects light whose spread is suppressed in the offset direction;
A second light emitting unit that is disposed in a gap between the first light emitting unit and the light receiving unit and that projects light that spreads at least in the offset direction, and
The light receiving unit is a human body detection sensor that is shared by the first light emitting unit and the second light emitting unit and has a resolution in the offset direction with respect to an incident position of light (Claim 1).

A second aspect of the present invention is a faucet for discharging water to a sink provided with a drain outlet at the bottom,
The human body detection sensor of the first aspect;
According to a sensor signal output from the human body detection sensor, an automatic faucet provided with water supply control means for switching water discharge / stop of water or adjusting the water discharge amount is provided. .

  The light receiving unit of the human body detection sensor according to the present invention has a resolution of a light incident position in the offset direction. An optical configuration including a combination of the first light emitting unit that projects light in which spread in the offset direction is suppressed and the light receiving unit that has resolution of the incident position of light in the offset direction is triangulation. Suitable for distance measurement based on the principle.

  Needless to say, when using light in which the spread in the offset direction is suppressed, it is difficult to detect an object positioned out of the projection direction. The second light emitting unit disposed in the gap between the first light emitting unit and the light receiving unit effectively works in detecting such surrounding objects. The second light emitting unit projects light that spreads at least in the offset direction, unlike the projection light of the first light emitting unit. The optical configuration including the second light emitting unit that projects light that spreads in the offset direction is suitable for detection of an object in an area that spreads in the offset direction.

  In the human body detection sensor according to the present invention, the first light emitting unit and the second light emitting unit share the light receiving unit, thereby suppressing an increase in component costs and the like. Further, the gap between the first light emitting unit and the light receiving unit that need to be arranged offset for distance measurement based on the principle of triangulation is effectively used, and the second light emitting unit is placed in the gap. By arranging, the increase in size is suppressed.

  As described above, the human body detection sensor according to the present invention is a sensor in which an optical configuration suitable for securing a wide detection area and an optical configuration suitable for distance measurement are incorporated at low cost and in a compact manner. . The automatic faucet incorporating this human body detection sensor enables product design that takes advantage of the freedom of installation of a compact human body detection sensor, and also has excellent operation reliability realized by a human body detection sensor with high detection performance. Can be a product.

As the light receiving unit provided in the human body detection sensor according to the present invention, an image sensor such as a CCD or a CMOS can be employed in addition to PSD.
The human body detection sensor according to the present invention can be applied to an automatic faucet for a washstand, an automatic faucet for a kitchen, an automatic water supply device for a toilet bowl with an automatic washing function, and the like. Furthermore, the human body detection sensor of this example may be applied to various automatic devices such as a hand-holding operation, lighting that automatically turns on in response to a human body, and an automatic door.

A human body detection sensor according to a preferred aspect of the present invention is a distance or distance to a detection target by specifying an incident position with respect to the light receiving unit with respect to reflected light generated by the light projected by the first light emitting unit. Is provided with distance measuring means for determining the degree of the above (claim 2).
For example, if the presence or absence of the detection target is determined using the distance to the detection target or the degree of the distance, the detection accuracy can be improved with high certainty.

A human body detection sensor according to a preferred aspect of the present invention is configured to detect the presence or absence of a moving object by detecting temporal changes in reflected light generated by light projected from the second light emitting unit and incident on the light receiving unit. The moving body determination means is provided (claim 3).
According to the second light emitting unit that projects light that spreads in the offset direction, a range in which a moving object can be determined can be formed wide in the offset direction. In addition, about the light of a said 2nd light emission part, it is also good to suppress the spreading of the light of the direction orthogonal to the said offset direction.

The moving body determination means provided in the human body detection sensor according to a preferred aspect of the present invention determines the moving body by threshold determination regarding a temporal displacement amount of the incident position of the reflected light incident on the light receiving unit (Claim 4). .
In particular, in the case of a human body detection sensor equipped with the distance measuring means, the structure for obtaining the incident position can be shared by the distance measuring means and the moving object detecting means, thereby efficiently using hardware or software resources. It can be utilized. Hardware costs or software development costs can be suppressed, and attractive product costs for consumers and the like can be realized.

The 2nd light emission part with which the human body detection sensor of the suitable one mode concerning the present invention is provided is arranged near this light reception part side in the gap between the 1st light emission part and the light reception part. 5).
In applications other than distance measurement, it is ideal that the positions of the light emitting unit and the light receiving unit match. This is because the light projection direction and the reflection direction coincide with each other, and no shielding or concealment occurs. If the second light emitting unit is arranged close to the light receiving unit in the gap between the first light emitting unit and the light receiving unit, the ideal arrangement can be obtained.

The perspective sectional view showing the kitchen counter 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 figure which shows the example of the light reception waveform of the reflected light at the time of projecting the light of the 1st light emission part in an Example. Explanatory drawing explaining the calculation method and detection method of the gravity center position of a light reception waveform in an Example. Explanatory drawing explaining the principle of triangulation in an Example. The flowchart which shows the flow of a detection process in an Example. Explanatory drawing which illustrates the mode of the reflected light which generate | occur | produces in the detection state in an Example, and the light reception waveform of the reflected light by a light-receiving part. Sectional drawing explaining the component arrangement structure of a sensor unit 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 kitchen counter 15. The contents will be described with reference to FIGS.
As shown in FIG. 1, the kitchen counter 15 of this example includes a counter 155 provided with a sink 151 that is recessed in a concave shape, and a faucet 16 having a water outlet 168. The faucet 16 is erected on a counter top 156 that forms the upper surface of the counter 155. The sink 151 has a drain port 152 at the deepest portion thereof.

  The faucet 16 has a water discharge pipe 160 that is erected on the countertop 156 and bent so that the tip thereof faces the sink 151, and a base portion 161 that forms a base for the countertop 156. While the linear portion connected to the base 161 has a substantially circular cross section, the tip surface toward the sink 151 has a substantially rectangular shape. The cross-sectional shape of the water discharge pipe 160 changes from a circular shape to a rectangular shape due to a smooth cross-sectional shape change within a range from the bent portion to the tip.

  A sensor surface of a non-contact type touchless sensor 167 is disposed on the upper surface of the water discharge pipe 160. The touchless sensor 167 is a photoelectric proximity sensor using a combination of a light receiving element such as a phototransistor and a light emitting element. The touchless sensor 167 determines that it is detected when the light receiving element can receive the reflected light from the hand or finger in the vicinity of the detection range of several centimeters from the sensor surface. If a finger or a hand is placed over the sensor surface, water discharge and water stop can be switched to each other according to detection by the touchless sensor 167.

  As shown in FIG. 1, a filter plate 165 that forms a detection surface of the human body detection sensor 1 is disposed on the upper side, and a water discharge port 168 having a substantially rectangular cross section is disposed on the lower side. Is provided. A sensor unit 2 (FIG. 2) that constitutes the human body detection sensor 1 is disposed inside the resin filter plate 165 that selectively transmits light in the infrared region.

  The faucet 16 of this example is characterized in that in addition to the touchless sensor 167, the sensor unit 2 incorporated at the tip of the water discharge pipe 160 is provided. When only the touchless sensor 167 is used, when washing a large pot or dish that needs to be supported by both hands, it is necessary to place the pot or dish on the countertop 156 and then hold it over the sensor surface of the touchless sensor 167. . On the other hand, in the faucet 16 of this example in which the sensor unit 2 is incorporated at the tip of the water discharge pipe 160, water discharge is started by the operation of inserting a pan, a dish or the like supported by both hands into the water discharge area on the front end side of the water discharge pipe 160. it can. When washing is completed, it is very convenient to stop the water just by pulling out the pot and dish from the water discharge area.

  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 kitchen counter 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 two LED elements 251 and one line sensor (imaging element) 261 are accommodated in a housing 21, and power is supplied from the control unit 3. Operates upon supply. In the sensor unit 2, a first light emitting unit 25A for distance measurement by an area determining unit 321 described later, a second light emitting unit 25B for moving object determination by a moving object determining unit 322 described later, and a shared imaging unit (light receiving unit). 26) are arranged in parallel facing the filter plate 165 of the faucet 16.

  Each of the light emitting units 25 </ b> A and 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 units 25A and B and the imaging unit 26 are arranged offset in the horizontal direction (offset direction corresponding to the left and right direction in FIG. 2) with the partition wall 211 having light shielding properties interposed therebetween.

  In the sensor unit 2, the first light emitting unit 25A is a light emitting unit for distance measurement, and the second light emitting unit 25B is a light emitting unit for moving object determination, while the imaging unit 26 is a first light emitting unit 25A. And the second light emitting unit 25B. In this example, the timing of receiving the reflected light from the light of the light emitting unit 25A and the timing of receiving the reflected light of the light of the light emitting unit 25B are temporally different from each other, so that the imaging unit 26 by the light emitting units 25A and B is used. Sharing is possible.

  Here, the light emitting unit 25A for distance measurement and the imaging unit 26 must have an offset arrangement for distance measurement based on the principle of triangulation. The light emitting unit 25B for moving object determination is arranged in this gap by effectively utilizing the gap in the offset direction between the light emitting unit 25A and the imaging unit 26. According to such an arrangement structure of the light emitting units 25A and 25B and the imaging unit 26, the sensor unit 2 can be compactly designed. In this example, in the gap between the light emitting unit 25A and the imaging unit 26, the light emitting unit 25B for moving object determination is arranged closer to the imaging unit 26 side than the position corresponding to the center in the offset direction.

  As shown in FIG. 2, the LED element 251 is a light emitting element in which an LED chip 250 mounted in a cavity of a package substrate is sealed with a transparent resin 254. In the light emitting units 25A and 25B, the LED element 251 is covered with a light-shielding element case 252 provided with a slit hole 253. There is a difference in the formation direction of the slit hole 253 between the light emitting unit 25A for distance measurement and the light emitting unit 25B for moving object determination. According to the light emitting unit 25 </ b> A including the vertical slit hole 253, it is possible to project sharp light with a suppressed horizontal spread angle toward a detection target. According to the light emitting unit 25B including the horizontal slit hole 253, the vertical divergence angle is suppressed, and light spreading in the horizontal direction can be projected toward the 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. The line sensor 261 includes an electronic shutter (not shown), and the light reception (exposure) time can be adjusted using the electronic shutter. The line sensor 261 outputs imaging data every time the light receiving operation is executed in synchronization with the light emitting operation of the light emitting unit 25A or the light emitting unit 25B. 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. In the sensor unit 2 of this example, the line sensor 261 is incorporated so that the longitudinal direction of the light receiving area 263 coincides with the offset direction of the light emitting units 25A and 25B and the imaging unit 26.

  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 two LED elements 251, a detection processing unit 32 that executes detection processing, and a water supply control unit 33 that controls the solenoid 11. ing.

The imaging control unit 31 has functions as an imaging control unit 311 that controls the two LED elements 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 in which an imaging operation is performed and a non-operation period are alternately performed 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 imaging control means 311 performs light reception (exposure) of the line sensor 261 synchronized with light emission (LED light) of the LED element 251 and light reception (exposure) of the line sensor 261 under no light emission in one imaging operation. Continuously executed, the received light amount of the difference in exposure at the time of receiving light twice is obtained for each pixel. In this difference light reception waveform, the influence of ambient light is suppressed, and the component of the reflected light caused by the LED light is extracted.

The detection processing unit 32 includes an area determination unit (ranging unit) 321 and a moving body determination unit 322, which are detection processing execution units, a detection determination unit 324 that determines whether the detection state is a non-detection state, and a detection signal ( It has a function as detection output means 325 for outputting a sensor signal.
The area determination unit 321 determines the presence or absence of a detection target using the principle of triangulation based on the incident position (distance index) of the reflected light according to the light emission of the light emitting unit 25A. The area determination means 321 receives the light reception waveform of FIG. 5 (the amount of light received by each pixel 260 is determined according to one imaging operation including the light emission operation of the light emitting unit 25A (referred to as an imaging operation for distance measurement as appropriate)). The incident position of the reflected light is specified using the (distributed imaging data), and the presence / absence of the detection target is determined based on whether or not the incident position belongs to a predetermined detection area. In the figure, the horizontal axis x indicates the pixel number (pixel position), and the vertical axis D (x) indicates the amount of received light (pixel value) of the pixel 260 having the pixel number x.

  The area determination unit 321 in this example handles the barycentric position of the received light waveform as the incident position. In specifying the position of the center of gravity, first, as shown in FIG. 6, the received light amount data D (x) for each pixel constituting the received light waveform 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 lower right direction in FIG. The position of the pixel with the pixel number N (shown by a black circle) when the integrated value obtained by integrating the pixel values of the pixels 260 in order from the pixel 260 with the pixel number zero at the left end of the light receiving area 263 reaches SD / 2. Calculated as the barycentric position of the received light waveform. Here, the integrated value SD / 2 corresponds to the area of the region indicated by the hatching with the upward slope. This region is included in the region of the total sum SD, and is grasped as a cross hatch region in FIG. The distribution of the amount of received light for each pixel in FIG. 6 schematically represents the received light waveform in FIG.

  The principle of triangulation used by the area determination means 321 will be described with reference to FIG. 7 schematically showing the positional relationship between the sensor unit 2, the inner peripheral surface 150 of the sink 151, and the user's hand in the kitchen counter 15 of this example. Is done. In the drawing, the light emitting unit 25A and the imaging unit 26 are illustrated, while the light emitting unit 25B for moving object determination is omitted. When the reflected light from the hand, which is the detection target, of the LED light enters the line sensor 261, the incident position (distance index) varies depending on the distance H to the detection target. As the distance H is shorter, the incident position of the reflected light incident on the line sensor 261 is on the upper side in the figure, and as the distance H is longer, the incident position is on the lower side. Thus, the incident position of the reflected light with respect to the line sensor 261 is proportional to the distance to the detection target, and can be a distance index indicating the degree of this distance. The detection area (FIG. 6) set in the light receiving area 263 is an area corresponding to the detection distance (FIG. 7) to be detected. The center of gravity calculated as described above is treated as an incident position, and whether or not the center of gravity is within the detection area is determined based on whether the distance to the detection target that causes the reflected light is within the detection distance shown in FIG. Is substantially synonymous with the determination of whether or not.

  The moving object determination unit 322 determines the presence or absence of a moving object using a temporal change in reflected light according to the light emission of the light emitting unit 25B. The moving body determination unit 322 compares the two received light waveforms respectively acquired by two temporally continuous imaging operations (referred to as an imaging operation for moving body determination as appropriate), and determines the presence or absence of a moving body.

  The moving body determination unit 322 of this example obtains the barycentric position for each of the two received light waveforms corresponding to the two imaging operations by the same calculation method as described above, and handles them as incident positions of the received light waveforms. Then, it is determined that there is a moving object when the obtained displacement amounts of the two center-of-gravity positions exceed a predetermined threshold value, and it is determined that there is no moving object when the displacement amount is less than the predetermined threshold value.

  Hereinafter, the operation of the human body detection sensor 1 of this example will be described using the flowchart of FIG. When the power is turned on, first, a received light waveform acquisition routine including the imaging operation for distance measurement is executed (P101), and a distance measurement determination routine (P102) using the acquired received light waveform (see FIG. 5). Is executed. In this distance measurement determination routine, the barycentric position (see FIG. 6) of the received light waveform is specified as the incident position of the reflected light, and whether or not the barycentric position belongs to a predetermined detection area (FIG. 6). A determination is made. If the position of the center of gravity belongs to a predetermined detection area and the distance to the detection target is within the predetermined detection distance (S103: YES), the detection signal is output in response to the determination that there is a detection target. The water discharge is started (S104).

  Under water discharge, that is, under a detection state, a received light waveform acquisition routine including the distance measurement imaging operation and the moving object determination imaging operation is executed every time a predetermined interval time elapses and the operation period starts. (P105). In this routine, a light receiving waveform for distance measurement corresponding to an imaging operation for distance measurement and a light reception waveform for moving object determination corresponding to the imaging operation for moving object determination are acquired. In particular, two light reception waveforms that are temporally continuous are acquired as the light reception waveforms for moving object determination.

  First, using the light receiving waveform for distance measurement, it is determined whether or not the peak received light amount exceeds a predetermined threshold (S106). As shown in FIG. 9A, when reflected light from a dish or the like during dishwashing is incident on the sensor unit 2 and the amount of light received by any pixel 260 is equal to or greater than the threshold value (S106: NO), the received light waveform as it is. Is used to execute a distance measurement determination routine having the same specifications as P102 (P117). If the position of the center of gravity (incident position) belongs to the predetermined detection area and the distance to the detection target is within the predetermined detection distance (S118: YES), detection is performed according to the determination that there is a detection target. The output of the signal is continued and water discharge is continued (S119).

  On the other hand, as shown in FIG. 9B, when the direction of reflected light from a dish or the like being dishwashed deviates and does not enter the sensor unit 2 and there is no pixel 260 whose received light amount is greater than or equal to the threshold (S106: YES), the moving object The moving object determination routine is executed using the two received light waveforms for determination (P107). In this moving object determination routine, as shown in FIG. 9C, the center-of-gravity positions are calculated for two light receiving waveforms that are temporally continuous for moving object determination. When the displacement of the centroid position value is equal to or greater than a predetermined value, it is determined that there is a moving body (S108: NO).

  In addition to the above, cases where the amount of light received by the pixel 260 in S106 is less than the threshold include cases where the target portion does not exist, cases where the projection light is transmitted through a plate such as glass, and water used to wash a cup, etc. A case where the projection light is irregularly reflected by a bubble or the like is considered. Further, in the case where the direction of the reflected light is deviated and does not enter the sensor unit 2 as described above, there is a higher possibility of generation of sharp specularly reflected light from a specular object such as a stainless steel knife or a silver plate dish.

  If it is determined in step S108 that there is a moving object (S108: NO), the output of the detection signal is continued and water discharge is continued (S119). In this case, the process proceeds to the received light waveform acquisition routine of P105, and thereafter, a series of processing from P105 to S119 is repeatedly executed until no detection target is detected.

  If it is determined in step S108 that there is no moving body (S108: YES), it is determined that the state is not detected, and the output of the detection signal is stopped and switched to water stop (S109). In this case, the process proceeds to the received light waveform acquisition routine of P101, and thereafter, a series of processing from P101 to S103 is repeatedly executed until a detection target is detected.

Here, the tendency of determination by the distance measurement determination routine in step S117 or the like and the moving object determination routine in step S107 will be described.
According to the distance measurement determination routine for determining the presence / absence of a detection target using the center of gravity position (incident position) of the reflected light, the detection target can be detected with high reliability regardless of the color or reflectance of the detection target. On the other hand, in the case of a transparent glass tableware, a dish covered with a layer of foaming water, etc., there is a possibility that the LED light is transmitted or diffusely reflected and sufficient reflected light cannot be obtained. If sufficient reflected light cannot be obtained, it becomes difficult to specify the position of the center of gravity with high accuracy, and the determination accuracy by the area determination means 321 tends to be impaired.

  In such a case, the moving object determination routine works effectively. Whether it is glass tableware or a dish whose surface is covered with a layer of water, fine movements are constantly occurring during dishwashing. In the middle of such a fine movement, even if it is a glass tableware, the LED light is reflected or the portion where it is reflected fluctuates from moment to moment depending on its posture, etc. Will occur. According to the moving object determination routine for determining the presence or absence of a moving object according to the temporal change of the reflected light, it is possible to determine the glass tableware or the like being washed relatively easily.

  As described above, the human body detection sensor 1 of the present example is a sensor that achieves improved detection performance by combining the advantages of the area determination unit 321 that executes the distance measurement determination routine and the moving body determination unit 322 that executes the moving body determination routine. It is. In the non-detection state where the water faucet 16 is in the water stoppage, erroneous detection is suppressed by executing detection determination using only the area determination means 321. On the other hand, in the detection state corresponding to the water discharged from the faucet 16, the determination by the moving object determination unit 322 is combined with the determination by the area determination unit 321. When the amount of received light exceeds the threshold value under the detection state, the determination result by the area determination unit 321 is prioritized. When the amount of received light is less than the threshold value under the detection state, the determination result by the moving object determination unit 322 is given. Priority is given to switching to the non-detection state.

  According to the human body detection sensor 1, for example, when a glass cup is washed with a kitchen faucet, projection light (LED light) passes through the cup and does not return sufficient reflected light, making a distance determination. Even if it becomes unstable, the detection state can be maintained by moving object determination. Thereby, it is possible to avoid the possibility that the water will be switched to the non-detection state and the water will be stopped even though the cup is being washed.

  As described above, the human body detection sensor 1 of this example is a sensor whose detection performance is improved by combining the distance measurement determination routine and the moving object determination routine. In the human body detection sensor 1, the number of parts is reduced by sharing the imaging unit 26 between the light emitting unit 25A for distance measurement and the light emitting unit 25B for moving object determination, and an increase in cost is suppressed. Further, by effectively utilizing the gap in the offset direction between the light emitting unit 25A and the imaging unit 26, which is essential for distance measurement, and arranging the light emitting unit 25B for moving object determination in this gap, the large size of the sensor unit 2 is achieved. Is suppressed.

  Although the human body detection sensor 1 is a sensor in which both an optical configuration suitable for motion detection and an optical configuration suitable for distance measurement are incorporated, an increase in cost and an increase in size are suppressed. Moreover, in this human body detection sensor 1, high detection performance is realized by combining two types of determination methods having different optical configurations. The faucet 16 employing the human body detection sensor 1 is a product in which high operational reliability is realized in a low cost and compact manner, and is suitable as an automatic faucet for a kitchen.

In this example, an electronic shutter is used to control the length of the exposure time of the line sensor 261. Although an electronic shutter is not essential and can be omitted, a mechanical shutter that physically blocks light from entering the line sensor 261 may be employed instead of the electronic shutter.
When there is a variation in sensitivity among the pixels 260 of the line sensor 261, the detection process may be executed after correcting the pixel value of each pixel 260.

  In this example, the position of the center of gravity of the received light waveform is used as the incident position of the reflected light. Instead of the position of the center of gravity, the peak position of the received light waveform may be specified as the incident position. Furthermore, in this example, the center of gravity position is calculated by simple calculation. However, if there is a margin in calculation processing capacity, the center of gravity position may be calculated mathematically strictly.

  In addition, although this example is an example which applied the human body detection sensor 1 to the kitchen counter 15, the faucet of a washbasin may be sufficient. 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.

  The sensor unit 2 of this example is a unit that is compactly configured by sharing the imaging unit (light receiving unit) 26 between the light emitting unit 25A and the light emitting unit 25B. Instead of this, a light receiving unit may be provided. As the light receiving unit 26 corresponding to the light emitting unit 25B for moving object determination, a light receiving unit including a PSD element that can output the position of the center of gravity of the received light waveform may be employed. Since it is not necessary to calculate and obtain the position of the center of gravity, the calculation load for moving object determination can be suppressed.

  Further, in the sensor unit 2 of this example, the light emitting units 25A and 25B and the imaging unit 26 are arranged on a straight line. The distance measuring light emitting unit 25A needs to be offset in the horizontal direction with respect to the image pickup unit 26, but the light emitting unit 25B for moving object determination is located at any position around the image pickup unit 26. There may be. The light emitting unit 25B is preferably arranged closer to the imaging unit 26 than the light emitting unit 25A.

The requirements for the arrangement structure of the light emitting units 25A and 25B and the imaging unit 26 in the sensor unit 2 will be described with reference to FIG. In addition, the cross section of the partition 211 is abbreviate | omitted in the same figure.
In this example, as shown in the figure, the light emitting unit 25A for distance measurement, the light emitting unit 25B for moving object determination, and the imaging unit 26 are arranged on a straight line. Of course, it is not an essential requirement to arrange the light emitting unit 25B for moving object determination on the straight line on which the light emitting unit 25A for distance measurement and the imaging unit 26 are arranged. The meaning of disposing the light emitting unit 25B in the gap between the light emitting unit 25A and the imaging unit 26 is the dot inside the housing 21 and the gap between the light emitting unit 25A and the imaging unit 26 in FIG. The light emitting section 25B is arranged at any location in the hatching area.

  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 ... Kitchen counter, 16 ... Water faucet (automatic water faucet), 11 ... Solenoid (water supply control means), 12 ... Water supply piping, 167 ... Touchless sensor, 2 ... Sensor unit, 25A and B ... Light emitting part, 251 ... LED element, 26 ... imaging part (light receiving part), 260 ... pixel, 261 ... line sensor (imaging element), 263 ... light receiving area, 3 ... control unit, 30 ... control board, 31 ... imaging control part 311 ... Imaging control means, 312 ... Reading means, 32 ... Detection processing unit, 321 ... Area determination means (ranging means), 322 ... Moving object determination means, 324 ... Detection determination means, 325 ... Detection output means, 33 ... Water supply Control unit

Claims (6)

A photoelectric human body sensor having a light emitting part and a light receiving part,
A first light emitting unit that is arranged offset from the light receiving unit and projects light whose spread is suppressed in the offset direction;
A second light emitting unit that is disposed in a gap between the first light emitting unit and the light receiving unit and that projects light that spreads at least in the offset direction, and
The said light-receiving part is a human body detection sensor which is shared by the said 1st light emission part and the said 2nd light emission part, and is provided with the resolution | decomposability of the said offset direction about the incident position of light.   The distance measuring unit according to claim 1, wherein the reflected light generated by the light projected by the first light emitting unit is specified with an incident position with respect to the light receiving unit to obtain a distance to the detection target or a degree of the distance. Human body detection sensor.   3. The human body according to claim 1, further comprising a moving body determination unit that detects a temporal change in reflected light generated by the light projected by the second light emitting unit and incident on the light receiving unit to determine the presence or absence of a moving body. Detection sensor.   The human body detection sensor according to claim 3, wherein the moving body determination unit determines a moving body by a threshold determination regarding a temporal displacement amount of an incident position of the reflected light incident on the light receiving unit.   5. The human body detection sensor according to claim 1, wherein the second light emitting unit is arranged close to the light receiving unit in a gap between the first light emitting unit and the light receiving unit. A faucet that discharges water into a sink with a drain at the bottom;
The human body detection sensor according to any one of claims 1 to 5,
An automatic water faucet comprising: a water supply control means for executing switching of water discharge / stop water of the water faucet or adjustment of the water discharge amount in accordance with a sensor signal output by the human body detection sensor.

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