Abstract:
A distance detection determination device includes positioning brackets that couple to a housing for the device. The positioning brackets include an emitting positioning bracket and a receiving positioning bracket that respectively hold and accurately position an infrared light emitter and an infrared light receiver.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Phase Application claiming the benefit of and priority to International Application No. PCT/CN2009/073578, filed Aug. 27, 2009, which claims the benefit of and priority to Chinese Patent Application No. 200810042136.3, filed Aug. 28, 2008. The entire disclosures of International Application No. PCT/CN2009/073578 and Chinese Patent Application No. 200810042136.3 are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an infrared induction device, particularly to a distance detection induction device applied in the automatic operation for sanitation and bathroom, such as automatic sensing faucet, automatic flush urinal etc. 
     BACKGROUND OF THE INVENTION 
     The infrared sensor has been widely used in the sanitary equipment, such as automatic sensing faucet, automatic flush urinal, flush facilities of the toilet, toilet seat having the hot water sprayer, hand dryer, toilet having the fan providing hot blast, etc. 
     Most of traditional infrared sensors adopt the active sensing method, i.e. the infrared emitter emits the infrared light with certain wavelength, and then the infrared receiver receives the infrared light after the reflection of the human body, further the infrared sensor judges the intensity of the reflected signals to realize the automatic sensing and judging. However, the infrared sensor could not complete the automatic sensing and judging if the target has low reflectivity to infrared light (for example, the black clothing, hair, etc.). There is only few infrared light could be received by the infrared receiver after the infrared light from the infrared emitter was reflected by such matter. The intensity of the reflected signals is not strong enough, so that the above infrared sensor fails to judge whether there is a target existing in the sensing area. 
     To solve the above-mentioned problem of induction malfunction in the traditional infrared sensing sanitary ware, the Position Sensitive Detector (PSD) is introduced to the automatic operation for sanitation and bathroom. Shown as  FIG. 9 , the PSD sensor is a kind of photoelectric apparatus which is sensitive to the position of the incident light. When the incident light irradiates on the different position of the photosensitive surface of the PSD, the PSD will send out the different electrical signal. Using the triangulation principle, the PSD can accurately survey the distance to realize the auto-induction judgment. Shown as  FIG. 9 , the light from the light source irradiates on the surface of the detected target after focused by the lens LI. The reflected light is focused onto the one-dimensional PSD by the lens L 2  and forms a luminous spot. If the distance between the center of the lens L 1  and the center of the lens L 2  is “b”, the distance from the lens L 2  to the surface of the PSD is “f’, the distance between the luminous spot focused on the surface of the PSD and the center of the lens L 2  is “x”, the detected distance DIS can be expressed as: DIS=bf/x according to the principle of the similar triangles PAB and BCD. Therefore, so long as the value of the distance between the luminous spot focused on the surface of the PSD and the center of the lens L 2  “x” is surveyed, the detected distance DIS can be determined. 
     When the distances of the detected target body fall into the pre-determined range, the distance detection induction device will control the sanitary fittings to work. Because the distance detection induction device achieves the purpose of the auto-induction by the way of judging the distance between the target and the distance detection induction device, not by the way of judging the intensity of the emitting signal, the problem of the induction malfunction caused by weak reflected signal in the traditional infrared sensing devices is solved. 
     However, it is necessary that the components of the distance detection induction device have higher positioning precision, therefore, so how to ensure the positioning precision of the device need to be solved. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a distance detection induction device having higher positioning precision. 
     The purpose of the present invention is realized by the following technical solutions: a distance detection induction device comprises a housing, a condensing lens, a circuit board, an infrared light emitting means, a light receiving means for receiving and sensing the infrared light which is emitted by the infrared light emitting means and reflected by target, and a shielding cover for shielding. The housing comprises a main body and two round openings on the top of the main body. The condensing lens comprises an emitting lens and a receiving lens respectively located at the openings of the housing. The circuit board bearing multiple electronic components is used for processing signal, and is mounted inside the main body of the housing. The infrared light emitting means is an infrared light-emitting diode mounted on the circuit board, and emits the infrared light to the emitting lens. The light receiving means is a distance detecting sensing module mounted on the circuit board to sense the reflected light focused by the receiving lens. The shielding cover is mounted around the infrared light emitting means and light receiving means to prevent them from electromagnetic interference. The distance detection induction device further comprises the positioning brackets that match with the housing and are fixed to the housing. The positioning brackets includes the emitting positioning bracket and the receiving positioning bracket that respectively hold and accurately position the infrared light emitting means and light receiving means. 
     Further, the emitting positioning bracket includes two protruding parts respectively at the two sides of the emitting positioning bracket, and positioning grooves inside the housing match with the two protruding parts. 
     Further, the emitting positioning bracket also comprises a round opening at the position of the emitting lens on the top of the emitting positioning bracket and a holder that is mounted on the bottom of the emitting positioning bracket and is used for containing the infrared light emitting means. 
     Further, the circuit board has a hole, and the holder of the emitting positioning bracket passes through the hole, receives and positions the infrared light emitting means to the under side of the circuit board. 
     Further, the slots are set at the two sides of the holder to permit the weld legs of the infrared light emitting means to stretch out and to be welded to the circuit board. 
     Further, the support sticks are extended from the two sides of the emitting positioning bracket to support the emitting positioning bracket to touch against the circuit board. 
     Further, said receiving positioning bracket comprises a positioning transom, and the positioning grooves are set inside the housing to match with the free ends of the positioning transom. 
     Further, said receiving positioning bracket also includes a holder extended from the positioning transom in the horizontal direction to contain and position the light receiving means. 
     Further, said light receiving means is mounted to the under side of the circuit board; a hole is set in the circuit board; an opening is set in the holder; the light revived by the receiving lens arrives at the light receiving means through the hole and the opening. 
     Further, the slots are set at the two sides of the holder of the receiving positioning bracket to permit the weld legs of the light receiving means to stretch out and to be welded to the circuit board. 
     Further, said distance detection induction device also comprises a sealing component mounted between the receiving lens and the light receiving means. 
     Further, said distance detection induction device also comprises a circuit wire disposing means fixed on the housing by the screw. 
     Further, said distance detection induction device also includes an indicator demonstrating the normal or non-normal status of the device, and an indicating hole is set on the emitting positioning bracket. 
     Further, said shielding cover comprises a first shielding cover and a second shielding cover welded with said first shielding cover, and the first shielding cover is fixed to the housing by screws and touches said circuit board for grounding while the second shielding cover is fixed to the housing by clip structure; said infrared light emitting means and light receiving means are mounted between said shielding cover and said circuit board. 
     Further, said housing is made of the conductive material. 
     Compared with prior art, the components of the distance detection induction device of the present invention has higher positioning precision and can enhance induction performance of the overall device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1   a  is the three-dimensional view of the distance detection induction device of the present invention. 
         FIG. 1   b  is the three-dimensional view of the distance detection induction device of the present invention from other angle. 
         FIG. 2  is the exploded schematic drawing of the distance detection induction device of the present invention. 
         FIG. 3  is the exploded schematic drawing of the distance detection induction device of the present invention from other angle. 
         FIG. 4   a  is a part of the three-dimensional assembly chart of the distance detection induction device of the present invention. 
         FIG. 4   b  is the schematic drawing of  FIG. 4   a  from other angle. 
         FIG. 4   c  is the exploded schematic drawing of the structure shown on  FIG. 4   b.    
         FIG. 5  is the view of the housing of the distance detection induction device of the present invention. 
         FIG. 6  is the view of the emitting positioning bracket of the distance detection induction device of the present invention. 
         FIG. 7   a  is the exploded schematic drawing of the light receiving means and its positioning bracket of the distance detection induction device of the present invention. 
         FIG. 7   b  is the view of  FIG. 7   a  from other angle. 
         FIG. 8  is the sectional drawing along A-A in  FIG. 1   a.    
         FIG. 9  is the principle figure of the distance detection induction device of the prior art. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the present invention will be clearly described referring the attached drawings, wherein the same figures are marked for the same structure parts or same function. It is understood that the attached drawings is just for the description of the embodiments of the present invention, not a limitation to the present invention. Besides, the attached drawings are not drawn as the pro rata. 
     Shown as  FIG. 1  to  FIG. 7 , the distance detection induction device  100  of the present invention are mainly mounted on all kinds of the automatic sanitary equipments such as an urinal or toilet having automatic sensing device, a tap having automatic sensing device and so on. 
     The distance detection induction device  100  of the present invention mainly comprises a housing  1 , a condensing lens  2  for focusing, a circuit board  3  bearing multiple electronic components, an infrared light emitting means  4  for emitting the infrared light, a light receiving means  5  for receiving and sensing the reflected infrared light and a shielding cover  6  having the function of electromagnetic shielding. 
     In the above device, the infrared light emitting means  4  and the light receiving means  5  are mounted on the same side of the circuit board  3 . Shown as the embodiments of the present invention, the infrared light emitting means  4  and the light receiving means  5  are mounted onto the circuit board  3  by leg welding. The condensing lens  2  is fixed in the housing  1  and lens  2  comprises the emitting lens  21  which focuses and emits the infrared light and the receiving lens  22  which focuses the reflected infrared light onto the light receiving means  5 . 
     For the distance detection induction device  100 , the precise position between the infrared light emitting means  4  and the light receiving means  5  should be precisely set. The precise position among the infrared light emitting means  4 , the light receiving means  5  and the condensing lens  2  should be precisely set too. Therefore, the distance detection induction device  100  of the present invention comprises an emitting positioning bracket  7  which fixes the infrared light emitting means  4 , a receiving positioning bracket  8  which fixes the light receiving means  5 . The emitting positioning bracket  7  and the receiving positioning bracket  8  hold the infrared light emitting means  4  and the light receiving means  5 , and are coordinately positioned to the housing  1  to ensure the positioning precision of the infrared light emitting means  4  and the light receiving means  5 . 
     Moreover, the shielding cover  6  is mounted on the periphery of the circuit board  3 , and on the side that the infrared light emitting means  4  and the light receiving means  5  are mounted to prevent the infrared light emitting means  4  and the light receiving means  5  from the electromagnetic interference (EMI) of surroundings. 
     The housing  1  comprises a longitudinal long main body  10 , the first round opening  11  and the second round opening  12  on the top of the main body  10 . The condensing lens  2 , the circuit board  3  bearing multiple electronic components, the infrared light emitting means  4 , the light receiving means  5  and the shielding cover  6  are all set within the main body  10  of the housing  1 . Correspondingly, the emitting lens  21  and the receiving lens  22  of the condensing lens  2  are respectively mounted in the first round opening  11  and the second round opening  12 . The housing  1  is made of the insulating material such as ordinary plastic. 
     Indeed, in another embodiment of the present invention, the housing  1  is made of the conducting material such as metal, conducting plastics to prevent from the electromagnetic interference effectively. 
     In the superior embodiments of the present invention, the emitting lens  21  and the receiving lens  22  of the condensing lens  2  are installed into the first round opening  11  and the second round opening  12  of the housing  1  by injection molding. Particularly, the installation of the condensing lens  2  and the housing  1  is made by injection molding twice. First, the condensing lens  2  is molded. Then, the molded condensing lens  2  is put into the mold of the housing  1  and is molded together with the housing  1 . By injection molding, the problem of seal between the condensing lens  2  and the housing  1  is solved, and it also can ensure the relative positioning precision of the center of the condensing lens  2  and the housing  1 . The lower parts of the emitting lens  21  and the receiving lens  22  are all made into the cylindrical structure to ensure the positioning precision during injection molding with the housing  1 . 
     Specially, the emitting lens  21  is connected with the receiving lens  22  by the connection part  23 . In past design process, the emitting lens  21  and the receiving lens  22  are arranged alone. However, the relative position precision between the emitting lens  21  and the receiving lens  22 , and the relative position precision between the condensing lens  2  and both of the infrared light emitting means  4  and the light receiving means  5  should be precisely set. It is not easy to control the position precision if the emitting lens  21  and the receiving lens  22  are established alone, and it is too hard to reach the requirements of precision. Thus, the emitting lens  21  and the receiving lens  22  are connected as a whole by a connection part  23  to ensure the position precision. Further, the connection part  23  has at least a bending part to prevent the emitted infrared light emitted by lens  21  from conducting into the receiving lens  22  along the connection part  23  directly. It avoids unnecessary reflection and refraction effect of internal light, and ensures the detecting precision of the distance detection induction device. As shown on  FIG. 2  and  FIG. 3 , the connection part  23  is bended by several times as the “z” shape. Considered from the overall evaluation of cost and effect, in this structure it needs reflecting for two times for the emitted infrared light to conduct into the receiving lens  22  from the emitting lens  21 . The optical path turns more complex, which can more effectively prevent the emitted infrared light emitted by lens  21  from conducting into the receiving lens  22  directly. Surely, the bending part can be increased or reduced according to the practical application situation. In another embodiment of the present invention, the condensing lens  2  and the housing  1  also can be mounted by assembly. 
     Multiple electronic components are integrated into the circuit board  3 . The first hole  31  and the second hole  32  are placed just opposite to the emitting lens  21  and the receiving lens  22 . The first hole  31  allows the emitting positioning bracket  7  passing through. The circuit board  3  processes the signal and transmits the processed data to the master-control unit. Thus, the sanitary fitting is controlled further (not shown in the figure). 
     The infrared light emitting means  4  is infrared light-emitting diodes (IR LED) fixed on the circuit board  3 , and located on the under side of the circuit board  3  (As shown as  FIG. 2  and  FIG. 3 , the side of the circuit board  3  that faces the condensing lens  2  is the upside, and the opposite side is the under side of the circuit board  3 ). An indicator  41  is mounted on the under side of the circuit board  3  near the infrared light emitting means  4 , and is used for demonstrating the normal or the non-normal working status of the distance detection induction device  100  such as the insufficiency of the battery capacity. 
     The light receiving means  5  is a distance detecting sensing module (PSD Sensing Module) fixed on the circuit board  3 , and located on the under side of the circuit board  3 . 
     The shielding cover  6  is fixed on the base of the housing  1  by the screws  101  and  102  to shield the infrared light emitting means  4  and the light receiving means  5 . It includes the first shielding cover  61  and the second shielding cover  62 . The first shielding cover  61  is fixed with the housing  1  and is touched with the ground line of the circuit board  3  by the screws  101  and  102  for grounding. The second shielding cover  62  is fixed with the housing  1  by the clip structure and is touched with the first shielding cover  61  by welding for grounding. It is better to set like the above-mentioned means, than to install a whole shielding cover, which will be not easy to be installed. 
     The emitting positioning bracket  7  is fixed with the housing  1 . It includes a big round hole  71  at the top of the emitting positioning bracket  7  and coordinated with the emitting lens  21 , and includes the holder  72  in the bottom of the emitting positioning bracket  7  to hold the infrared light emitting means  4 . The diameter of the big round hole  71  is an approximate match to the emitting area of the emitting lens  21 . The support stick  73  are set on two sides of the emitting positioning bracket  7  to press against the circuit board  3  closely, so that the circuit board  3  could provide enough bracket force to the emitting positioning bracket  7  correspondingly to avoid many problems, such as the emitting positioning bracket  7  dropping out from the housing I during the installation process. Specially, the emitting positioning bracket  7  also includes square protruding parts  74  at the two sides of the emitting positioning bracket  7 . The square protruding parts  7   4  match with the positioning grooves  13  which are on the internal top of the housing  1 , so that the emitting positioning bracket  7  and the housing  1  can be positioned. Surely, the square protruding parts  74  also can be set at other positions of the emitting positioning bracket  7  and can be other shapes such as a cylinder protruding stand. The holder  72  of the emitting positioning bracket  7  goes through the first hole  31  in the circuit board  3  from the upside of the circuit board  3 , and takes in and positions the infrared light emitting means  4  to the under side of the circuit board  3 . The weld legs of the infrared light emitting means  4  are bent after outstretching through the slots (not marked) on the two sides of the holder  72 , and are welded on the circuit board  3 . The emitting positioning bracket  7  is made of the insulating material. Of course, it also can be made of the conducting material. When the emitting positioning bracket  7  is made of the conducting material, it works as a shield to prevent from the electromagnetic interference. 
     Shown as  FIG. 6 , the emitting positioning bracket  7  also includes a small round hole  75  and an indicating hole  76 . The small round hole  75  is near the holder  72  holding the infrared light emitting means  4 , and the indicating hole  76  is to show the light emitted by indicator  41 . Shown as  FIG. 8 , the small round hole  75  and the big round hole  71  form the cone-shaped channel of the infrared emission light, so the light is projected from the chip of the infrared light emitting means  4 , passing through the small round hole  75  and the big round hole  71 , and is projected out after focused by the emitting lens  21 . Thus, the light is not projected to other regions of the housing  1  to avoid affecting the efficiency and introducing the light interference. No reflection and refraction of the interior light is projected to the light receiving means  5 , and affects the detection effect. The chip of the infrared light emitting means  4  is so big that the emitting light has a big halo, which is a very disadvantageous factor to the light receiving means that needs precise signals and influences the detection result. In this embodiment of the present invention, the infrared light emitted out from the chip of the infrared light emitting means held in the holder  72  only passes through the small round hole  75  to project out. The light passes through the big round hole  71  and is focused by the emitting lens projecting out. The cross-section of the small round hole  75  is smaller than the light emitting area of the infrared light emitting means  4 , and the unnecessary light is blocked. It effectively reduces the affection of the halo to the detection signal, and enhances the detection precision. In this case, the emitting positioning bracket  7  is working as the guide means of the emitted light. 
     Shown as  FIG. 7   a  and  FIG. 7   b , the receiving positioning bracket  8  comprises the transom  81  fixed onto the housing  1  and the holder  82  connected together with the transom  81 . The holder  82  holds the light receiving means  5 . The holder  82  has the holding space  821  holding the light receiving means  5 . A rectangular aperture  820  is set on the top of the holder  82  aligning with the second hole  32  on the circuit board  3  to let the received light arrive at the receiving surface of the light receiving means  5 . The holder  82  is formed by extending the middle part of the transom  81  horizontally, so the weld legs of the light receiving means  5  can extend out from the slots on the two sides of the holder  82  to conveniently make the welding. For effective positioning, the two free ends of the transom  81  are fitted with the positioning groove  14  on the two sidewalls of the main body  10  of the housing  1 . 
     The distance detection induction device  100  of the present invention also includes a circuit wire disposing means  9 . The circuit wire disposing means  9  can tidy up the wires (not shown in the figure) on the circuit board  3  effectively, and is fixed in the housing  1  by screw  103 . 
     The distance detection induction device  100  of the present invention also includes a sealing component  104  which mounted between the condensing lens  2  and the circuit board  3  for sealing. On one hand, the sealing component  104  can prevent the epoxy used for sealing from entering the light receiving means  5 ; for example, prevent the epoxy from entering the light receiving means  5  through the second hole  32 . On the other hand, the sealing component  104  can prevent the interference light from entering the housing  1  or the light receiving means  5 . In the present embodiment, the sealing component  104  is made of silicone rubber; of course, it also can be made of other sealing material. If permissible, similar seal structure can be used between the emitting lens  21  and the infrared light emitting means  4 . 
     Shown as  FIG. 8 , the first hole  31  and the second hole  32  are set on the circuit board  3 . The infrared light emitting means  4  projects the infrared emitting light to the emitting lens  21  through the first hole  31 . The emitting lens  21  focuses the infrared emitting light to the target area. When human body or moving target goes into the target area, the infrared light is reflected. The receiving lens  22  receives and focuses the reflected infrared light onto the light receiving means  5  through the second hole  32 . According to PSD triangulation principle, the light receiving means  5  surveys the distance of the target, then controls the sanitary fittings finally. Set like this, the infrared light emitting means  4  and the light receiving means  5  can be fixed on the under side of the circuit board  3  (The side of the circuit board  3  that faces the condensing lens  2  is the upside, and the opposite side is the under side of the circuit board  3 ). Because the focal distance of the condensing lens  2  is set with a determinate value, the thickness of the circuit board  3  can be part of the focal distance. Meanwhile, because other electronic components are set on the circuit board  3 , it can make highly efficient use of the inner space of the housing  1  and the space on either of upside or underside of the circuit board  3  to install the infrared light emitting means  4  and  5  among these electronic components. Such arrangement reduces the height and the volume of the whole distance detection induction device  100 . 
     Moreover, as the infrared light emitting means  4  and the light receiving means  5  are installed between the circuit board  3  and the shielding cover  6 , which can block the exterior disturbance, and the external interference could be shielded effectively. 
     The infrared light emitting means  4  and the light receiving means  5  of the distance detection induction device  100  of the present invention are fixed by the positioning brackets  7  and  8  to ensure the positioning precision of the infrared light emitting means  4  and the light receiving means  5 . The relative position of the infrared light emitting means  4  and the light receiving means  5  to the housing I can be ensured by fixing the positioning bracket  7  and  8  to the housing I coordinately. Since welding process starts after the infrared light emitting means  4  and the light receiving means  5  are fixed into the corresponding holders of the positioning bracket  7  and  8 , so that the position precisions of the infrared light emitting means  4  and the light receiving means  5  are not influenced by the installment. Therefore, it solves the problem that the position precisions is influenced by installation, which exist in prior art. Thus, it effectively solves the problems that the distance detection induction device  100  does not work well or even doses not work caused by the bad installation precision when the infrared light emitting means  4  and the light receiving means  5  are installed to the circuit board  3 . 
     Moreover, the production cost of the distance detection induction device  100  of the present invention is low, in favor of the popularization and application. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention.