Abstract:
A washroom device sensor uses at least one infrared beam that forms a longitudinal, rather than spot-shaped, sensing zone for detecting the presence of a user. The increased detection area of the longitudinal sensing zone ensures that at least a portion of the beam will contact a user using the washroom device. The beam may be adjustable in two or more directions to generate two or more sensing zones in different positions, allowing optimization of the sensing zone location with respect to a particular washroom device and the anticipated position of the device user.

Description:
TECHNICAL FIELD 
   The present invention relates to sensors for electronic control of washroom devices, and more particularly to a sensor that detects the presence of a user of a washroom device. 
   BACKGROUND OF THE INVENTION 
   Many public washrooms have incorporated sensors that automatically operate various washroom devices, such as urinals, water closets, hand dryers, faucets, and soap dispensers. Sensors are particularly useful when coupled to a flush valve, allowing urinals and water closets to be flushed without manual operation by the user. Generally, sensors transmit an infrared beam in a desired direction; if the beam is reflected from a user of the device back toward a receiver in the sensor, power is applied to operate the washroom device (e.g. actuating a flush valve for a toilet, opening a faucet valve, etc.). 
   Currently used sensors transmit a beam having a spot-shaped sensing zone, which covers a small sensing area and/or has a low, diffused power density. The beam itself is pointed forward, creating a sensing zone that is directly in front of the flush valve on which the sensor is mounted. If the sensor is mounted on a water closet with a toilet, the height of the beam may cause the beam to miss a user if, for example, the user is seated rather than standing in the water closet and cause the sensor to fail to activate the flush valve. This may lead the user to believe that the sensor and flush valve are not working even when they are functioning normally. 
   Attempts to remedy this problem may entail adding a refractive layer that changes the infrared beam&#39;s direction. Although this change allows the beam to detect a user in a different position, there is still the possibility that the beam will miss the user (e.g., the beam may travel between a user&#39;s legs if the water closet is being used as a urinal). The refracted beam also does not allow the beam direction to be adjusted based on the type of washroom device on which the sensor would be mounted. Because different washroom devices have different predicted user positions, a sensor having a beam optimized in one direction for a given washroom device may not be optimized for another washroom device. 
   There is a desire for a sensor that can detect a washroom device user more accurately. 
   There is also a desire for a washroom device sensor that allows adjustment of a beam direction. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a washroom device sensor that uses at least one infrared beam to detect the presence of a user. The beam is spread to form a sensing zone having a longitudinal sensing zone, such as a linear, elliptical, or rectangular zone. The increased detection area of the longitudinal sensing zone ensures that at least a portion of the beam will contact a user using the washroom device. 
   In one embodiment, the sensor allows the beam direction to be adjusted between two or more positions to generate at least two sensing zones, such as a first sensing zone and a second sensing zone spaced vertically apart from the first sensing zone. A particular zone can be selected by either adjusting a position of a beam emitter itself, by changing a beam direction, or switching between two or more emitters that emit beams in different directions. By providing a beam adjustment mechanism, the inventive sensor can be adapted easily for different washroom devices requiring different user positions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a representative diagram of a washroom device incorporating a sensor according to one embodiment of the invention; 
       FIG. 2  is a cutaway view of the sensing device according to one embodiment of the invention; 
       FIG. 3  is a cutaway view of the sensing device according to one embodiment of the invention; 
       FIG. 3  is a diagram illustrating sensing zones used by the sensor according to one embodiment of the invention; and 
       FIG. 4  is a representative diagram of a circuit board according to one embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
     FIGS. 1 and 2  illustrate a sensor  100  and its operating environment according to one embodiment of the invention.  FIG. 1  illustrates the sensor  100  mounted onto a urinal  102 , but the sensor  100  can also be mounted in a water closet that can be used as both a urinal and a toilet, a sink faucet, hand dryer, soap dispenser, bathing apparatus (e.g., shower, tub) or any other washroom device. For simplicity, the term “washroom device  102 ” will cover all possible devices that can be used in conjunction with the sensor  100  and is not limited to the urinal shown in FIG.  1 . 
   As shown in  FIGS. 1 and 3 , the sensor  100  is able to transmit a beam  104  that can be directed to cover at least two sensing zones  106 . In one embodiment, the beam  104  is an infrared beam that forms a longitudinal sensing zone  106 . Possible sensing zone shapes include a line, ellipse, rectangle, or any other shape having a width longer than its height. 
   By using a longitudinal sensing zone  106  rather than a spot-shaped zone, the inventive sensor  100  detects the presence of a user more accurately because the beam provides a larger detection range with a higher power density and makes it more likely for at least a portion of the beam&#39;s path to contact a user of the washroom device. The longitudinal sensing zone  106  allows detection of users even with variations in the user&#39;s height, proportions, and orientation relative to the washroom device  102  because the zone&#39;s shape ensures that at least a portion of the beam  104  will be reflected from a user using the device  102  back into the sensor  100 . As is clear from the figures. The longitudinal sensing zone having a cross-sectional shape that is non-circular with an elongated dimension in one direction, and a smaller dimension in another direction. By describing the sensing zone as “longitudinal.” applicant means that the sensing zone could be otherwise described as being non-circular with a cross-sectional shape having a first larger dimension in one direction and a shorter dimension in another direction. 
   The beam direction can be adjusted so that sensing zone  106  position is optimized for a given washroom device.  FIGS. 1 through 4  illustrate one embodiment where the beam  104  direction can be switched to create either a high sensing zone  106   a  or a low sensing zone  106   b . As shown in  FIG. 3 , the high and low zones  106   a ,  106   b  respectively lie above and below a center point  108  of an optical range  110  rather than directly at the center point  110 . In one embodiment, the sensing zones  106  are about 6 inches long when viewed approximately 42 inches away from the sensor  100 . 
     FIG. 2  is a cutaway view of a flush valve  200  incorporating the sensor  100  according to one embodiment of the invention. As is known in the art, flush valves are often used in conjunction with toilets and urinals. The sensor  100  is implemented via a circuit board  202 , at least one emitter  204  that emits the beam  104 , at least one receiver  206  that detects a beam reflected from an object (e.g., a user using the washroom device), and an optic structure  208  that correspond with the emitter  204  and the receiver  206 . The embodiment shown in  FIGS. 2 and 4  illustrate a sensor  100  that has two emitters  204 , one that emits a beam associated with the high sensing zone  106 a and one that emits a beam associated with the low sensing zone  106   b . Alternatively, the sensor  100  may incorporate a single emitter  204  whose beam direction can be adjusted (e.g., through an adjustable mounting structure) to form the high and low zones  106   a ,  106   b . Providing vertical adjustability of the beam direction further improves the detection capabilities of the beam and allows the sensor to be adapted to different types of washroom devices that may have different optimal sensing zones, depending on the anticipated position of the device user (e.g., standing or sitting). 
   During installation of the sensor  100  to the washroom device  102 , the installer can select the beam orientation (e.g., high or low) that will provide a desired sensing zone location. The actual beam selection can be conducted via a switch, such as a DIP switch  250  (see FIG.  4 ), or other beam adjustment means. Possible alternative beam adjusters may include other types of switches, electrical controllers, software, actuators, or any other mechanism that can change the beam direction from the emitter by controlling the emitter  204  itself and/or by controlling the optic device(s) (lens)  210  associated with the emitter  204 . 
   The optic structure  208  may include an optic device  210  associated with each emitter  204 . For example, if there are two emitters  204 , the sensor  100  may include two optic devices  210 , one associated with each emitter  204 . In one embodiment, each optic device  210  is a known collimating optic set having an optics lens that forms the emitter output into a fine, round beam, and a cylindrical lens that spreads the round beam horizontally to form a beam having a longitudinal sensing zone. Other optic devices  210  known in the art may be used to shape the emitter  204  output to form the desired sensing zone shape. Alternative embodiments may include multiple optic devices  210  associated with each emitter  204  or different ratios between the optic devices  210  and the emitters  204 . 
   In one embodiment, the emitters  204  and receivers  206  are grouped into emitter/receiver pairs  212   a . In the embodiment shown in  FIGS. 2 and 4 , the top emitter  204  and receiver  206  are arranged so that the receiver  206  lies above the emitter  204 , while the bottom emitter/receiver pair are arranged in a mirror image with respect to the top pair (i.e., where the receiver  206  lies below the emitter  204 ). To prevent false triggering, the emitter/receiver pairs  212   a ,  212   b  are arranged inside a tunnel  214  having a compartment  215  for each pair  212   a ,  212   b . The tunnel  214  ensures that the receivers  206  beams only from the front of the sensor  100 . 
   During installation of the/sensor  100  to the washroom device  102 , the installer can select the beam orientation (e.g., high or low) that will provide a desired sensing zone location. The actual beam selection can be conducted via a switch, such as a DIP switch, or other beam adjustment means. Possible alternative beam adjusters may include other types of switches, electrical controllers, software, actuators, or any other mechanism that can change the beam direction from the emitter by controlling the emitter  204  itself and/or by controlling the optic device(s)  210  associated with the emitter  204 . 
   In one embodiment, if the installer selects a low sensing zone  106   b  as the desired zone, the emitter  204  in the pair  212   a  will transmit the infrared beam through the top optic device. If a user is within the detection range of the beam, the beam will bounce off the washroom device user, travel through the bottom optic device and be detected by the receiver  206  in the bottom pair  212   b . Conversely, if the installer selects a high sensing zone  106   a , the beam will bounce off the user, travel through the top optic device and be detected by the receiver  206  in the top pair  212   a . If the sensor  100  incorporates a different number of emitter and receivers and/or if the emitters and receivers are arranged in a configuration different than that shown in the Figures, then the beam emission and detection patterns may be modified as well according to principles within those of ordinary skill in the art. 
   In addition to the sensor  100  circuitry itself, the flush valve  200  shown in  FIG. 3  includes a solenoid valve  216  coupled to the sensor  100 , a manual washroom device actuator  215 , and a housing  230 . The solenoid valve  216  can be actuated by the sensor  100  via any known manner. If the sensor  100  will be used with a washroom device other than a toilet, urinal, etc., then the sensor  100  would be coupled with other components specific to that washroom device. 
   To provide visual feedback to the user, the sensor  100  may also include a visible light source  232 , such as an LED. In one embodiment, the visible light source  232  is mounted above the optic structure  208  rather than within the tunnel  214 . The beam emitted by the visible light source  232  can simply be output through the housing  230 , without being transmitted through any optics. The visible light source  232  allows the user to determine whether he or she is correctly aligned with the sensor  100  by checking whether the light beam is visible on his or her body. 
     FIG. 4  is a representative diagram of one circuit board  202  that can be used in the inventive sensor  100 . As explained above, the emitters  204  and receivers  206  can be arranged in pairs  212   a ,  212   b , with each pair  212   a ,  212   b  placed inside a compartment  215  of the tunnel  214 . In the embodiment shown in  FIG. 4 , the installer can select the beam direction, and therefore the sensing zone height, via a function selection switch  250 , such as a DIP switch, which connects the emitter/receiver pair  212   a ,  212   b  corresponding to a selected sensing zone height with a power supply. The function selection switch  250  therefore allows selection of the beam direction without having to modify any optics within the sensor  100 . Any other control device may also be used to select an emitter/detector pair. If a single emitter  204  is used, to adjust the beam direction of the emitter  204  by, for example, changing the position of the emitter  204  itself or placing a refractive lens in front of the emitter  204 . A range adjuster  302  may also be incorporated to adjust the sensitivity of the sensor  100  by setting a threshold level at which the receiver  206  would recognize the presence of the reflected beam. 
   Although the above description focuses on incorporating the inventive sensor in a flush valve for a urinal or water closet, the sensor can be incorporated in any washroom device where automatic operation is desired (e.g., sink faucet, soap dispenser, shower, hand dryer, etc.) without departing from the scope of the invention. 
   It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that the method and apparatus within the scope of these claims and their equivalents be covered thereby.