Abstract:
An electronic input device with piezoelectric sensor is provided, the electronic input device includes a housing, a piezoelectric sensing layer provided on the surface of the housing, an electrode plate provided and served to cover on top of the piezoelectric sensing layer. When a user&#39;s skin is in contact with the electrode plate, galvanic skin signals that represent the user&#39;s physiology status are transferred to the input device, meanwhile the piezoelectric sensing layer sends piezoelectric signals corresponding to the pressing level pressed by the user. When the piezoelectric sending layer is pressed to a proper level, effective galvanic skin signals are determined to the input device.

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application Serial Number 96139060, filed Oct. 18, 2007. 
     BACKGROUND 
     1. Field of Invention 
     The present invention relates to an input device, more particularly to an electronic input device with piezoelectric sensor. 
     2. Description of Related Art 
     A conventional art of galvanic skin response (GSR) is often adopted in a physiology measuring device used to measure the electrical resistance of the skin generated due to vasoconstriction, vasodilatation or secretion of the sweat gland when a person has emotional arousal. When the measuring device is in contact with human&#39;s skin, physiological pressure and emotion can therefore be quantified by analyzing the changes of the electrical resistance of the human&#39;s skin. 
     Skilled people in the art have adopted the above mentioned measuring device on surfaces of an electronic input device, e.g. a mouse, a keyword or a telephone. So when a user touches electrodes provided on the surfaces of the input devices, the current physiology status of the user is measured and proper relative information is also obtained. Thus a purpose of monitoring the user&#39;s physiology status is achieved (e.g. sending a signal indicating that the user needs a rest), or a purpose of indicating the user to operate the electronic input device is achieved (e.g. after sensing a command is finished then another command is proceed). 
     However, since not every user uses an input device with same operating habit, when they are using the input device, the pressing levels on the galvanic skin electrodes are varied. That is, when the areas of the electrodes on which a user&#39;s skin touches and the applied pressure are changed, the measured galvanic skin resistance is therefore changed. Hence, both the contact areas of the electrodes and the pressure applied on the electrodes need to be put into considerations for obtaining a more effective and accurate data, otherwise the operations of monitoring or indicating according to the invalid data are worthless. 
     SUMMARY 
     The present invention provides an electronic input device with piezoelectric sensor, for obtaining more effective and accurate piezoelectric data so the electronic input device can monitor physiology statuses or indicate operation procedures with respect to the precision data. 
     The electronic input device with piezoelectric sensor provided by the present invention comprises a piezoelectric sensing layer provided on a surface of a housing of the electronic input device. The piezoelectric sensing layer is electrically connected to a piezoelectric controlling/measuring circuit provided in the housing. The electrode plate is provided on top of the piezoelectric sensing layer, and electrically connected to a galvanic skin controlling circuit provided in the housing. When a user&#39;s skin is in contact with the electrode plate, galvanic skin signals measured by the electrode plate are transferred to the galvanic skin controlling circuit. Meanwhile corresponding piezoelectric signals are transferred to the piezoelectric measuring/controlling circuit by the piezoelectric sensing layer depending on the level of pressing the piezoelectric sensing layer via the electrode plate pressed by the user. When the piezoelectric sensing layer is pressed to a preset level, effective galvanic skin signals are determined to provide the input device. 
     According to one preferred embodiment of the present invention, plural piezoelectric sensing layers can be provided on the surface of the housing, each of the piezoelectric sensing layers is individually and electrically connected to the piezoelectric measuring/controlling circuit. When the piezoelectric sensing layers are pressed by a user, the pressed piezoelectric sensing layers respectively send different pressing level of piezoelectric signals to the piezoelectric measuring/controlling circuit, and the piezoelectric signals are received by a central processing circuit then are saved in a memory. Thus, information of the area, the shape and the center of applied pressure of the user-pressed portion of each of the piezoelectric sensing layers are recorded for future use. 
     For a conventional mechanical press-sensing fashion used for detection, when being operated, the current is varied due to the differences of the area of electrode touched by a user and the applied pressure, accordingly obtaining effective data is not likely to be achieved. The present invention utilizes the high sensitivity property of piezoelectric sensing material, so highly reliable galvanic skin data is obtained via an electronic input device. According to a preferred embodiment of the present invention, the electronic input device with piezoelectric sensor is not only simple in structure and assembly but also capable of effectively obtaining precise galvanic skin signals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objectives can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, where: 
         FIG. 1  is a partial exploded view of an electronic input device as a mouse device of a preferred embodiment of the present invention; 
         FIG. 2  is an electrical block diagram of the electronic input device provided by the present invention; 
         FIG. 3  is a partial exploded view of an electronic input device as a mouse device of another preferred embodiment of the present invention; 
         FIG. 4  is a front view of an electronic input device as a keyboard of the other embodiment of the present invention; 
         FIG. 5  is a side view of an electronic input device as a joystick device of the other embodiment of the present invention; 
         FIG. 6  is a front view of an electronic input device as a track ball device of the other embodiment of the present invention; 
         FIG. 7  is a front view of an electronic input device as a hand writing device of the other embodiment of the present invention; and 
         FIG. 8  is a side view of an electronic input device as an internet telephone device of the other embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It is to be understood that the following disclosure provides one or more preferred embodiments or examples for implementing different features of the disclosure. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     Referring to  FIG. 1  and  FIG. 2 , wherein  FIG. 1  is a partial exploded view of a mouse device,  FIG. 2  is an electrical block diagram of the input device provided by the present invention. As shown in  FIG. 1 , a surface of a housing  10  of a mouse device  1  is provided in sequence with a piezoelectric sensing layer  20 , an insulation layer  50  and an electrode plate  40 , and a control circuit  30  (not shown in  FIG. 1 ) is further provided inside the housing  10 . 
     Referring to  FIG. 4  to  FIG. 8 , the electronic input device provided by the present invention can be implemented on a mouse device  1 , a keyboard device  2  ( FIG. 4 ), a joystick device  3  ( FIG. 5 ), a track ball device  4  ( FIG. 6 ), a hand writing device  5  ( FIG. 7 ) or an interne telephone device  6  ( FIG. 8 ) etc. 
     In this embodiment, the piezoelectric sensing layer  20  includes a piezoelectric sensing material which is preferable to be quartz, LiNbO 3 , LiTaO 3 , AlN, ZnO, BaTiO 3 , PbZrTiO 3  or a polymer such as polyvinylidene difluoride (PVDF). 
     Wherein the piezoelectric sensing layer  20  in  FIG. 2  is electrically connected to a piezoelectric controlling/measuring circuit  301  provided on the control circuit  30  inside the housing  10 . The other surface of the piezoelectric sensing layer  20  is connected to a ground terminal  31 , so that the piezoelectric sensing layer  20  and the piezoelectric controlling/measuring circuit  301  can be defined as one piezoelectric sensor (in this embodiment the piezoelectric controlling/measuring circuit  301  further includes a measure circuit). When the surface of the piezoelectric sensing layer  20  is pressed by an external pressure, a phenomenon of inter-exchange between mechanical energy and electrical energy is generated so as to obtain continually piezoelectric signals, and the piezoelectric signals are transferred to the piezoelectric controlling/measuring circuit  301 . The relationship between the generated piezoelectric signals and the pressure applied are an invertible function, or a linear function under other conditions. Therefore a measured voltage value can be served to calculate the original pressure applied on the piezoelectric sensing layer  20 . 
     The electrode plate  40  is electrically connected to a galvanic skin controlling circuit  302  of the control circuit  30  provided inside the housing  10 , so when a user&#39;s skin is in contact with the electrode plate  40 , galvanic skin response values (GSR values) received by the electrode plate  40  are transferred to the galvanic skin controlling circuit  302  via the user&#39;s skin. The electrode plate  40  is preferably made of a conductive material such as stainless steel or chloride silver. The quantity of the electrode plate  40  provided can be more than one, in other words the plural electrode plates  40  can be provided on the surface of the housing  10 . In this embodiment, the area of the piezoelectric sensing layer  20  is substantially the same as the area of the electrode plate  40 , and at least one insulation layer  50  is provided as an electrical insulation between the electrode plate  40  and the piezoelectric sensing layer  20 . Therefore, the piezoelectric sensing layer  20  would not be interfered by the electrode plate  40 . 
     In the embodiment, beside the provided electrode plate  40  served as a piezoelectric measuring electrode, a ground electrode plate (not shown) can be further provided. Regardless of the insulation layer  50 , the ground electrode plate can be directly in contact with the piezoelectric sensing layer  20 . 
     Refer to  FIG. 1  and  FIG. 2 , a central processing circuit  303  is further provided on the control circuit  30  inside the housing  10 . The central processing circuit  303  is respectively and electrically connected to the piezoelectric controlling/measuring circuit  301  and the galvanic skin controlling circuit  302 , and a valid range of piezoelectric signal, e.g. 50 mV, is preset in the central processing circuit  303 . Thus, when the central processing circuit  303  simultaneously receives at least one piezoelectric signal and galvanic skin signal, the central processing circuit  303  determines if the received piezoelectric signal is within the valid range of piezoelectric signal; if so, the galvanic skin signals are calibrated then outputted, if not, the galvanic skin signals are ignored. 
     The central processing circuit  303  can be served to quantify the piezoelectric signal to patterns or numbers shown on a display unit  60 , e.g. an external display device or a screen provided on the housing  10 , for providing references to users. When the electrode plate  40  is in contact with and is pressed by a user via his/her skin, the piezoelectric sensing layer  20  provided below the electrode plate  40  is also pressed via the electrode plate  40  so as to generate a piezoelectric signal. When the central processing circuit  303  determines that the generated piezoelectric signal is not within the preset valid range of piezoelectric signal, a warning signal is therefore generated via the display unit  60 , so a user is informed whether the applied pressure is too small or too high. 
     On the other hand, when the central processing circuit  303  determines that the generated piezoelectric signal is within the preset valid range of piezoelectric signal, the galvanic skin signals corresponding to the piezoelectric signal are saved in a memory  304  by the central processing circuit  303  so subsequent analyze can be operated. Therefore when the piezoelectric sensing layer  20  is properly pressed, the input device  1  is provided with effective galvanic skin signals, so physiology of the user is monitored (for example sending a signal indicating that the user needs a rest), or indicating an operating procedure (for example after sensing a command is finished then another command is proceed). 
     In another embodiment of the present invention, referring to  FIG. 2  and  FIG. 3 , wherein  FIG. 3  is a partial exploded view of a mouse device; the quantity of piezoelectric sensing layer  20  can be more than one therefore plural piezoelectric sensing layers  20  are provided on the surface of the housing  10  in a matrix arrangement. Each of the piezoelectric sensing layers  20  is individually and electrically connected to the piezoelectric controlling/measuring circuit  301 . When the piezoelectric sensing layers  20  are pressed by a user, the pressed piezoelectric sensing layers  20  individually send a piezoelectric signal to the piezoelectric controlling/measuring circuit  301 , and the piezoelectric signals are received by the central processing circuit  303 . Then the piezoelectric signals are saved in the memory  304 , so information of which body portion of the user (finger(s), palm(s)) is used to press each of the piezoelectric sensing layers  20  and information of the area. The shape and the center of applied pressure of the user-pressed portion of each of the piezoelectric sensing layers  20  are recorded for future use. Regardless of that if each of the piezoelectric signals generated by the pressed piezoelectric sensing layers  20  is within the preset valid range of piezoelectric signal, the piezoelectric signals are all saved in the memory  304 . 
     After obtaining the information of the area, the shape and the center of applied pressure of the user-pressed portion of each of the piezoelectric sensing layers, the appearance of the housing  10  of the input device  1  can be designed to be more ergonomic for matching the using habits of the users so more accurate physiology information can be obtained. 
     The described application of the piezoelectric sensor is illustrated via the palm of the user being in contact with the surface of the housing of the mouse device, but surfaces of a left key  11  and a right key  12  of the mouse device also can be respectively provided with a piezoelectric sensing layer  20 , an insulation layer  50  and an electrode plate  40  in turn, to serve as another approach to obtain the user&#39;s physiology information. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.