Abstract:
A key assembly applicable in an electronic device for performing preset functions is provided. The key assembly includes a control member and at least one sensor, wherein the control member selectively enables any sensor to sense the external operation, and when an external operation is sensed, the sensor outputs a triggering signal for performing the corresponding function.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 095119711 filed in Taiwan, R.O.C. on Jun. 2, 2006, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a key assembly, and more particularly, a key assembly using sensors to sense the external state changes, so as to make the electronic device perform a preset function. 
     2. Related Art 
     The common electronic devices used in daily life or controlling equipments such as processing equipments used in industry all have key-in structure for controlling the above equipments. The conventional key structure substantially comprises spring-type structure and film-type structure. In the spring-type key structure, a pin is disposed on one side of the key body with respect to an electrical switch of the electronic device, and a spring is disposed between the key body and the electrical switch. When the user presses the spring-type key, the pin of the key body triggers the electrical switch by the elastic force of the spring, such that the electronic device performs the preset function corresponding to the electrical switch, and due to the elastic recovery characteristic of the spring, the key returns to its original position after being released. The film-type key structure is made of rubber, and the film-type key structure is disposed in the pre-designed key area of the electronic device. When the film-type key is pressed, the protrusion under the key structure is in electrically contact with the electrical switch corresponding to the key area, such that the electronic device performs the preset function corresponding to the electrical switch, and the film-type key returns to its original state due to the elastic characteristic of the rubber itself. 
     No matter the spring-type key structure using the spring for elastic recovery or the film-type key structure made of rubber, after being used for a long time, the elastic fatigue of the material occurs, thus influencing the sensitivity of the key structure, such that the key structure cannot certainty electrically contact with the electrical switch thoroughly. In order to accommodate the key body, spring, and electrical switch of the spring-type key structure in the conventional art, and due to the travel distance required when the spring-type structure is operated, the designed space of the electronic device is excessively large, thus the volume cannot be reduced, which cannot meet the requirements for the current electronic device of being light and thin. 
     In addition, in Utility Model NO. M246788 “Thermal Character and Symbol Inputting Apparatus and Key-in Unit thereof” issued in ROC Patent Gazette on Oct. 11, 2004, a plurality of thermal sensors is disposed on each key operating area on the surface of the keyboard substrate. When the user presses the key operating area, the corresponding thermal sensor senses a temperature variable signal, and after the signal has been processed, a key signal corresponding to the position of the thermal sensor is sent out. 
     The Utility Model NO. M246788 can significantly reduce the space and travel distance required by the spring-type key structure in the conventional art, however, the used thermal sensors requires an excessively long time for sensing the temperature, and the size of the contact area between the user and the operating area also influences the sensitivity of the thermal sensor. In addition, when the thermal sensor is used under different climates or in the environment having extremely large temperature difference such as tropical countries or frigid countries, the practical climate must be considered to adjust the thermal sensors. If the user carries along the electronic device having the thermal sensor to travel all over the world, different temperatures and climates possibly cause the accuracy reduction of the thermal sensor. 
     Also, in the thermal key-in unit disclosed in the Utility Model NO. M246788, the user touches the operating area such that the thermal sensor senses the temperature change of the operating area. However, there is no mechanism or means for limiting and protecting the thermal sensor being disposed in the operating area, the user may touch the operating area of the unnecessary key by mistake and an operation error occurs accordingly, thus causing trouble and inconvenience when the user uses the thermal key-in unit. 
     The spatial travel distance occupied by the spring-type key structure in the conventional art is excessively large, thus the volume of the electronic device cannot be reduced. The thermal sensor disclosed in the Utility Model NO. M246788 cannot solve the problem of the reduction of the sensing accuracy of the thermal sensor caused by a large temperature difference of the environment, and in addition, no means for protecting and limiting the thermal sensor is disposed in the operating area, thus an operation error easily occurs for the key-in unit. 
     SUMMARY OF THE INVENTION 
     In view of the above problems, the present invention provides a key assembly, for eliminating the limitations or defects that the occupied space and the travel distance of the spring-type key structure in the prior art are excessively large, and that the accuracy of the thermal sensor is reduced due to the temperature difference of the environment and thereby mis-operation easily occurs. 
     The key assembly disclosed in the present invention is applied in an electronic device comprising a plurality of electronic components. The key assembly comprises a plurality of sensors disposed on the electronic device, and a control member corresponding to the sensors. The sensor is used to sense the external changes of the electronic device, and the control member is movably disposed within the electronic device and has an opening. With the movement of the control member, the opening may selectively correspond to any sensor, and the corresponding sensor outputs a triggering signal to the electronic device according to the external state change, such that the electronic device performs the preset function corresponding to the key. 
     The sensor of the present invention is further disposed within the electronic device in a single form, and a metal blade spring of the control member selectively come into electrical contact with any conducting element of the electronic device, such that the sensor is electrically connected to the corresponding conducting element, and the conducting element outputs a preset signal to the electronic device, and then the sensor outputs a triggering signal to the electronic device together with the preset signal according to the external change. 
     The efficacy of the present invention lies in that, both the spatial travel distance and the number of components required by the key assembly are significantly reduced, thus the electronic device achieves the requirements of being light, thin, short, and small and thereby reducing the manufacturing cost. With the movement of the control member corresponding to the sensor, or as the metal blade spring of the control member is electrically contacted with the plurality of conducting elements, a preset signal is correspondingly output, the mis-operation of the electronic device caused by the key assembly being touched by mistake can be avoided. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only for, which, thus, is not limitative of the present invention, and wherein: 
         FIG. 1A  is an exploded schematic view of a first embodiment of the present invention; 
         FIG. 1B  is a schematic stereogram of the first embodiment of the present invention; 
         FIG. 2A  is an exploded schematic view of a second embodiment of the present invention; 
         FIG. 2B  is a schematic stereogram of the second embodiment of the present invention; 
         FIG. 3A  is an exploded schematic view of a third embodiment of the present invention; 
         FIG. 3B  is a schematic stereogram of the third embodiment of the present invention; 
         FIG. 4A  is an exploded schematic view of a fourth embodiment of the present invention; 
         FIG. 4B  is a schematic stereogram of the fourth embodiment of the present invention; 
         FIG. 5A  is an exploded schematic view of a fifth embodiment of the present invention; and 
         FIG. 5B  is a schematic stereogram of the fifth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The key assembly disclosed according to the present invention is applied in an electronic device. Electronic devices include, but not limited to, personal computers (PC), notebooks, digital cameras, mobile phones, PDAs, etc. In the following detailed description of the present invention, the digital camera is taken as the most preferred embodiment of the present invention. However, the accompanying drawings are only used for making reference and illustration, but not intend to limit the present invention. 
       FIG. 1A  and  FIG. 1B  are an exploded schematic view and a schematic stereogram of a first embodiment of the present invention respectively. The key assembly  100  disclosed in the present invention is applied in an electronic device  200  having a plurality of electronic components  210 , wherein the electronic components  210  comprise circuit boards, sensing units, lenses, etc. In the first embodiment of the present invention, a plurality of sensors  110  is disposed within the electronic device  200 . When the user presses the linear direction corresponding to one sensor  110 , the corresponding sensor  110  outputs a triggering signal to the electronic device  200  according to the external change, so as to perform the preset function of the corresponding sensor  110 . 
     Referring to  FIG. 1A  and  FIG. 1B , the sensor  110  is a pyroelectric IR sensor capable of sensing the infrared ray emitted from the human body. When the pyroelectric IR sensor has sensed the infrared ray from the human body, the sensor  110  generates a signal change, so as to control the electronic device  200  to perform the preset function indicated by the sensor  110 . In addition, a plurality of through holes  220  corresponding to the sensor  110  is opened on the housing of the electronic device  200 , such that it is convenient for the user to press the position of the sensor  110  corresponding to the preset function to be performed. In order to prevent the sensitivity of the sensor  110  from being influenced by the external dirty dust, and prevent circuit short of the electronic components  210  caused by liquids flowing into the electronic device  200  via the through holes  220 , a transparent cover  221  is engaged in the through holes  220 , and the material of the transparent cover  221  can be transparent material such as acrylic material or glass, which does not reduce the sensing efficiency of the sensor  110 . 
       FIG. 2A  and  FIG. 2B  are an exploded schematic view and a schematic stereogram of a second embodiment of the present invention respectively. The key assembly  100  disclosed in the present invention is applied in an electronic device  200  having a plurality of electronic components  210 . The key assembly  100  comprises a plurality of sensors  110  disposed within the electronic device  200 , and a turntable  120  corresponding to the sensors  110 . The sensors  110  are used to sense the external change of the electronic device  200 , and the turntable  120  is movably disposed within the electronic device  200 . The turntable  120  is provided with an opening  130  with respect to the electronic device  200 , and as the turntable  120  rotates freely, the opening  130  selectively corresponds to any of the sensors  110 , such that the corresponding sensor  110  senses the external change only through the opening  130 , thus preventing the user from pressing the sensing position of other sensors by mistake and thereby causing mis-operation. When the user presses the linear direction corresponding to the sensor  110 , the corresponding sensor  110  outputs a triggering signal to the electronic device  200  according to the external change, so as to perform the preset function of the corresponding sensor  110 . 
     Referring to  FIG. 2A  and  FIG. 2B , the sensor  110  is a pyroelectric IR sensor. A transparent cover  221  is engaged in the through hole  220 , and the material of the transparent cover  221  can be transparent material such as acrylic material or glass, which does not reduce the sensing efficiency of the sensor  110 . 
     Please refer to  FIG. 2A  and  FIG. 2B , the turntable  120  used for avoiding mis-operation comprises a main body  122  and an operation part  123 , wherein the operation part  123  is disposed on the outer edge of the main body  122 , and protrudes from one side of the electronic device  200 . A plurality of identification marks  140  is printed on the operation part  123 , thus, it is convenient for the user to rotate the turntable  120  and recognize the position of the sensor  110  corresponding to the current opening  130 . Also, a plurality of rabbets  160  is disposed on the outer edge of the turntable  120 , and a positioning element  170  is disposed on one side of the electronic device  200 . Different rabbets  160  correspond to different sensors  110  in position, when the turntable  120  is rotated such that one of the rabbets  160  presses against the positioning element  170 , the opening  130  is just aligned with the sensor  110  corresponding to the rabbet  160 , thus, it is convenient for the user to align the opening  130 , the sensor  110 , and the through hole  220  in the same straight line. 
       FIG. 3A  and  FIG. 3B  are an exploded schematic view and a schematic stereogram of a third embodiment of the present invention respectively. The control member of the present invention further can be a plate  121 , which is movably disposed within the electronic device  200 . The plate  121  is disposed with an opening  130  with respect to the electronic device  200 , and as the plate  121  moves linearly, the opening  130  selectively corresponds to any one of the sensors  110 , such that the corresponding sensor  110  senses the external change only through the opening  130 , thus preventing the mis-operation of the electronic device  100 . When the user presses to the linear direction corresponding to the sensor  110 , the corresponding sensor  110  outputs a triggering signal to the electronic device  200  according to the external change, so as to perform the preset function of the corresponding sensor  110 . The sensor  110  is a pyroelectric IR sensor. A transparent cover  221  is embedded in the through hole  220 , and the material of the transparent cover  221  can be transparent material such as acrylic material or glass, which does not reduce the sensing efficiency of the sensor  110 . 
     Referring to  FIG. 3A  and  FIG. 3B , the plate  121  used for preventing mis-operation comprises a main body  122  and an operation part  123  disposed on the outer edge of the main body  122 . A plurality of identification marks  140  is printed on the housing of the electronic device  200  corresponding to the operation part  123 , such that it is convenient for the user to identify the position of the sensor  110  corresponding to the opening  130  on the plate  121 . Also, a positioning element  170  is disposed on the operation part  123  of the plate  121 , and a plurality of rabbets  160  corresponding to the sensors  110  is disposed on one side of the electronic device  200 . When the positioning element  170  of the plate  121  is moved to one of the rabbets  160 , the opening  130  is just aligned with the sensor  110  corresponding to the rabbet  160 , thus, it is convenient for the user to align the opening  130 , the sensor  110 , and the through hole  220  in the same straight line. 
       FIG. 4A  and  FIG. 4B  are an exploded schematic view and a schematic stereogram of a fourth embodiment of the present invention respectively. The key assembly  100  disclosed in the present invention is applied in an electronic device  200  having a plurality of electronic components  210 , wherein the electronic components  210  comprise circuit boards, sensing units, lenses, etc. The key assembly  100  comprises a sensor  110  disposed within the electronic device  200 , a plurality of conducting elements  150  disposed within the electronic device  200 , and a turntable  120  corresponding to the sensor  110 . The sensor  110  is used to sense the external change of the electronic device  200 , and the turntable  120  is movably disposed within the electronic device  200 . The turntable  120  has a metal blade spring  124  on one side of the turntable  120  opposite to the conducting element  150  and an opening  130  corresponding to the sensor  110 . As the turntable  120  rotates freely, the metal blade spring  124  selectively corresponds to any one of the conducting elements  150 , such that the sensor  110  is electrically connected to the corresponding conducting element  150 , and the corresponding conducting element  150  outputs a preset signal. When the user presses to the linear direction corresponding to the sensor  110 , together with the preset signal of the conducting element  150 , the sensor  110  outputs a triggering signal to the electronic device  200  according to the external change, so as to perform the preset function of the sensor  110 . The sensor  110  is a pyroelectric IR sensor. A transparent cover  221  is embedded in the through hole  220 , and the material of the transparent cover  221  can be transparent material such as acrylic material or glass, which does not reduce the sensing efficiency of the sensor  110 . 
     Referring to  FIG. 4A  and  FIG. 4B , the turntable  120  comprises a main body  122  and an operation part  123  disposed on the outer edge of the main body  122 , and the operation part  123  protrudes from one side of the electronic device  200  to facilitate the user to rotate the turntable  120 . A plurality of identification marks  140  is printed on the operation part  123 , thus, it is convenient for the user to recognize the position of one conducting element  150  that is electrically connected to the metal blade spring, so as to determine the preset signal output by the current conducting element. Also, a plurality of rabbets  160  is disposed on the operation part  123  of the turntable  120 , and a positioning element  170  is disposed on one side of the electronic device  200 . When one of the rabbets  160  presses against the positioning element  170  due to the rotation of the turntable  120 , the metal blade spring  124  is just electrically contacted with the conducting element  150 , thus, it is convenient for the user to electrically connect the metal blade spring  124  to the corresponding conducting element  150 . 
       FIG. 5A  and  FIG. 5B  are an exploded schematic view and a schematic stereogram of a fifth embodiment of the present invention respectively. The key assembly  100  disclosed in the present invention is applied in an electronic device  200  having a plurality of electronic components  210 , and the electronic components  210  comprise circuit boards, sensing units, lenses, etc. The key assembly  100  comprises a sensor  110  disposed within the electronic device  200 , a plurality of conducting elements  150  disposed within the electronic device  200 , and a plate  121  corresponding to the sensor  110 . The sensor  110  is used to sense the external change of the electronic device  200 , and the plate  121  is movably disposed within the electronic device  200 . The plate  121  has a metal blade spring  124  disposed on one side of the plate  121  opposite to the conducting element  150 , and as the turntable  120  rotates freely, the metal blade spring  124  selectively corresponds to any one of the conducting elements  150 , such that the sensor  110  is electrically connected to the corresponding conducting element  150 , and the corresponding conducting element  150  outputs a preset signal. When the user presses to the linear direction corresponding to the sensor  110 , together with the preset signal of the conducting element  150 , the sensor  110  outputs a triggering signal to the electronic device  200  according to the external change, so as to perform the preset function of the sensor  110 . The sensor  110  is a pyroelectric IR sensor. A transparent cover  221  is embedded in the through hole  220 , and the material of the transparent cover  221  can be transparent material such as acrylic material or glass, which does not reduce the sensing efficiency of the sensor  110 . 
     Referring to  FIG. 5A  and  FIG. 5B , the plate  121  comprises a main body  122  and an operation part  123  disposed on the outer edge of the main body  122 . A plurality of identification marks  140  is printed on the housing of the electronic device  200  corresponding to the operation part  123 , thus, it is convenient for the user to recognize the position of the sensor  110  corresponding to the opening  130  of the plate  121 . Also, a positioning element  170  is disposed on the operation part  123  of the plate  121 , and a plurality of rabbets  160  corresponding to the position of the sensor  110  is disposed on one side of the electronic device  200 . When the positioning element  170  of the plate  121  is moved to one of the rabbets  160 , the metal blade spring  124  is just electrically contacted with the conducting element  150 , thus, it is convenient for the user to electrically connect the metal blade spring  124  to the corresponding conducting element  150 . 
     It should be noted that, the preset function indicated by the sensor  110  according to the present invention is the function of controlling the direction, and the corresponding identification marks  140  are direction indications. Those skilled in the art can also change the preset function indicated by the sensor  110  to selection function, shortcut function, and the like, which is not limited in the embodiments disclosed in the present invention. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.