Abstract:
Embodiments provide the energy recovery system capable of converting mechanical energy of a touch input to a touch screen panel into electrical energy and storing the converted electrical energy. The energy recovery system may include a touch screen panel including a piezoelectric material, an energy recovery device recovering electrical energy generated by the piezoelectric material, and an electrical energy storage device storing the recovered electrical energy.

Description:
CLAIM OF PRIORITY 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0035924, filed on Apr. 2, 2013, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference in their entirety. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     Embodiments of the present invention generally relate to an energy recovery system for recovering mechanical energy of touch input to a touch screen panel, and more specifically, to an energy recovery system for recovering mechanical energy of touch input to a touch screen panel including a piezoelectric layer. 
     Description of the Related Art 
     A touch screen panel is an input device that allows a user&#39;s instruction to be input by selecting an instruction content displayed on a screen of a display device or the like with a user&#39;s hand or object. 
     To this end, the touch screen panel is formed on a front face of the display device to convert a contact position into an electrical signal. Here, the user&#39;s hand or object is directly in contact with the touch screen panel at the contact position. Accordingly, the instruction content selected at the contact position is input as an input signal to the image display device. Since such a touch screen panel can be substituted for a separate input device connected to a display device, such as a keyboard or mouse, its application fields have been gradually extended. 
     Meanwhile, with the development of technologies in electronic and communication fields, the use of a mobile device, e.g., a smart phone or tablet PC has recently been increased. The mobile device receives electrical energy supplied from a battery built therein. Studies on a technique for increasing electrical capacity of a battery or decreasing power consumption of a mobile device so as to increase the use time of the mobile terminal have been actively conducted, but studies on a technique for producing electrical energy from the use of a mobile device have hardly been conducted. 
     SUMMARY OF THE INVENTION 
     Embodiments provide an energy recovery system capable of converting mechanical energy of a touch input to a touch screen panel into electrical energy and storing the converted electrical energy. 
     According to an aspect of the present invention, an energy recovery system may include a touch screen panel including a piezoelectric material, an energy recovery device recovering electrical energy generated by the piezoelectric material, and an electrical energy storage device storing the recovered electrical energy. 
     According to an embodiment, the touch screen panel may include a first substrate, a first electrode formed on the first substrate, a piezoelectric layer formed on the first electrode and including the piezoelectric material, a second electrode formed on the piezoelectric layer, and a second substrate formed on the second electrode. 
     The touch screen panel may further include a first insulation layer formed between the first electrode and the piezoelectric layer; and a second insulation layer formed between the second electrode and the piezoelectric layer. 
     The piezoelectric material may be disposed in a pillar shape between the first and second insulation layers. 
     The piezoelectric layer may further include a plurality of spacers arranged between the first and second insulation layers. 
     According to another embodiment, the touch screen panel may include a first substrate, a piezoelectric layer formed on the first substrate and including the piezoelectric material, a first electrode formed on the piezoelectric material, an elastic deformation layer formed on the first electrode, a second electrode formed on the elastic deformation layer, and a second substrate formed on the second electrode. 
     The touch screen panel may further include an insulation layer formed between the piezoelectric layer and the first electrode. 
     According to still another embodiment, the touch screen panel may include a first substrate, a first electrode formed on the first substrate, a piezoelectric layer formed on the first electrode and including the piezoelectric material, a second electrode formed on the piezoelectric layer, and a second substrate formed on the second electrode. 
     The touch screen panel may further include a first insulation layer formed between the first electrode and the piezoelectric layer; and a second insulation layer formed between the second electrode and the piezoelectric layer. 
     The piezoelectric layer may be made of a mixture of the piezoelectric material and the elastic deformation material. 
     The piezoelectric material may have elastic deformation characteristics. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. 
       In the drawing figures, dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being “between” two elements, it can be the only element between the two elements, or one or more intervening elements may also be present. Like reference numerals refer to like elements throughout. 
         FIG. 1  is a block diagram showing an energy recovery system constructed as an embodiment according to the principles of the present invention. 
         FIG. 2  is a sectional view showing an embodiment of a touch screen panel shown in  FIG. 1 . 
         FIG. 3  is a sectional view showing another embodiment of the touch screen panel shown in  FIG. 1 . 
         FIG. 4  is a sectional view showing still another embodiment of the touch screen panel shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. In addition, when an element is referred to as being “on” another element, it can be directly on the another element or be indirectly on the another element with one or more intervening elements interposed therebetween. Also, when an element is referred to as being “connected to” another element, it can be directly connected to the another element or be indirectly connected to the another element with one or more intervening elements interposed therebetween. Hereinafter, like reference numerals refer to like elements. 
       FIG. 1  is a block diagram showing an energy recovery system constructed as an embodiment according to the principles of the present invention. 
     Referring to  FIG. 1 , an energy recovery system  1  includes a touch screen panel  10 , an energy recovery device  20  and an energy storage device  30 . 
     The touch screen panel  10  is disposed on a front face of a display device in a mobile device. The touch screen panel  10  recognizes a user&#39;s touch input to the display device and transmits a coordinate value of the recognized touch input to a processor (not shown). In this case, the processor performs a process corresponding to the coordinate value received from the touch screen panel  10 . 
     The touch screen panel  10  may include a piezoelectric material. The piezoelectric material converts mechanical energy into electrical energy. That is, the piezoelectric material outputs current having a voltage value corresponding to a mechanical strain applied to the piezoelectric material. The piezoelectric material may be a mixture configured with one or a combination of two or more among materials having piezoelectric characteristics, such as crystal, ceramic and biological matter. 
     The energy recovery device  20  recovers electrical energy generated by the piezoelectric material included in the touch screen panel  10 . Specifically, the energy recovery device  20  receives current output from the piezoelectric material, and rectifies the received current to be output to the energy storage device  30 . 
     The energy storage device  30  receives the current rectified from the energy recovery device  20 , and stores the electrical energy converted by the piezoelectric material. The energy storage device  30  supplies the stored energy to the mobile device including the energy recovery system  1 . 
     In  FIG. 1 , the energy recovery device  20  and the energy storage device  30  are distinguished as circuits separated from each other, but the technical spirit of the present invention is not limited thereto. For example, the energy recovery device  20  and the energy storage device  30  may be implemented as one circuit. 
       FIG. 2  is a sectional view schematically showing an embodiment of a touch screen panel shown in  FIG. 1 . 
     Referring to  FIG. 2 , the touch screen panel  10  includes a first substrate  100 , a first electrode  110 , a piezoelectric element  130 , a second electrode  150 , and a second substrate  160 . 
     The first and second substrates  100  and  160  support other components  110 ,  120 ,  130 ,  140  and  150  of the touch screen panel  10 . Each of the first and second substrates  100  and  160  may be implemented with a transparent glass substrate or plastic substrate. 
     As shown in  FIG. 2 , the first electrode  110  is formed on the first substrate  100 , and the second electrode  150  is formed beneath the second substrate  160 . The touch screen panel  10  recognizes a user&#39;s touch input according to a change in dielectric constant between the first and second electrodes  110  and  150 , and outputs a coordinate value of the recognized touch input to the processor. The first and second electrodes  110  and  150  may be made of a transparent metal. 
     The piezoelectric element  130  converts mechanical energy of the user&#39;s touch input into electrical energy, and supplies the converted electrical energy to the energy recovery device  20 . 
     The first electrode  110  and the piezoelectric element  130  are electrically connected to each other, and the second electrode  150  and the piezoelectric element  130  are electrically connected to each other. To this end, the touch screen panel  10  may include a first insulation layer  120  formed between the first electrode  110  and the piezoelectric element  130 , and a second insulation layer  140  formed between the second electrode  150  and the piezoelectric element  130 . 
     The piezoelectric element  130  includes a first piezoelectric plate  131 , a second piezoelectric plate  133  spaced-apart from the first piezoelectric plate  131 , a plurality of piezoelectric pillars  135 , and a plurality of spacers  132  made of an elastic deformation material. The first and second piezoelectric plates  131  and  133  may be disposed parallel to each other. The plurality of piezoelectric pillars  135  and the plurality of spacers  132  are interposed between the first piezoelectric plate  131  and the second piezoelectric plate  133 . More specifically, the plurality of spacers may be dispersed among the plurality of piezoelectric pillars  135 . Each spacer  132  may be disposed spaced-apart from immediately adjacent piezoelectric pillars  135 . The piezoelectric element  130  continuously extends across the entire area of the touch screen panel  10 , or at least continuously extends across the display area of the touch screen panel  10 . 
     The first piezoelectric plate  131  is formed between the first insulation layer  120 , and the plurality of piezoelectric pillars  135  and spacers  132 , and is electrically connected to one input terminal (not shown) of the energy recovery device  20 . The piezoelectric plate  133  is formed between the second insulation layer  140 , and the plurality of piezoelectric pillars  135  and spacers  132 , and is electrically connected to another input terminal (not shown) of the energy recovery device  20 . If a user&#39;s touch input is applied, the first and second piezoelectric plates  131  and  133  and the plurality of piezoelectric pillars  135  convert mechanical energy of the touch input into electrical energy according characteristics of the piezoelectric material, and supplies the converted electrical energy to the energy recovery device  20 . Alternatively, the first and second piezoelectric plates  131  and  133  may not be included in the piezoelectric element  130 . Thus, the plurality of piezoelectric pillars  135  and spacers  132  are formed directly between the first and second insulation layer  120  and  140 . 
     The plurality of spacers  132  are formed in a pillar shape between the first and second insulation layers  120  and  140 . The plurality of spacers  132  restores deformation of the touch screen panel according to the user&#39;s touch input. 
       FIG. 3  is a sectional view schematically showing another embodiment of the touch screen panel shown in  FIG. 1 . 
     Referring to  FIG. 3 , the touch screen panel  10  includes a first substrate  200 , a piezoelectric layer  210 , a first electrode  230 , an elastic deformation layer  240 , a second electrode  250  and a second substrate  260 . 
     The first and second substrates  200  and  260  support other components  210 ,  220 ,  230 ,  240 ,  250  and  260  of the touch screen panel  10 . Each of the first and second substrates  200  and  260  may be implemented as a transparent glass substrate or plastic substrate. 
     The piezoelectric layer  210  is formed on the first substrate  200 , and is made of a piezoelectric material. The piezoelectric layer  210  is electrically connected to the energy recovery device  20 . If a user&#39;s touch input is applied, the piezoelectric layer  210  converts mechanical energy of the touch input into electrical energy according to characteristics of the piezoelectric material, and supplies the converted electrical energy to the energy recovery device  20 . The piezoelectric layer  210  continuously extends across the entire area of the touch screen panel  10 , or at least continuously extends across the display area of the touch screen panel  10 . 
     The first electrode  230  is formed on the piezoelectric layer  210 , and the second electrode  250  is formed beneath the second substrate  260 . The touch screen panel  10  recognizes a user&#39;s touch input according to a change in dielectric constant between the first and second electrodes  230  and  250 , and outputs a coordinate value of the recognized touch input to the processor. The first and second electrodes  230  and  250  may be made of a transparent metal. 
     The piezoelectric layer  210  and the first electrode  230  are electrically connected to each other. To this end, the touch screen panel  10  may include an insulation layer  220  formed between the piezoelectric layer  210  and the first electrode  230 . 
     The elastic deformation layer  240  is formed between the first and second electrodes  230  and  250 . The elastic deformation layer  240  is made of an elastic deformation material, for example, silicone or polymer material such as polyurethane, so as to restore deformation of the touch screen panel according to the user&#39;s touch input. Young&#39;s modulus of the elastic deformation layer may be about 2000 kg/cm 2 . 
       FIG. 4  is a sectional view showing still another embodiment of the touch screen panel shown in  FIG. 1 . 
     Referring to  FIG. 4 , the touch screen panel  10  includes a first substrate  300 , a first electrode  310 , a piezoelectric layer  330 , a second electrode  350  and a second substrate  360 . 
     The first and second substrates  300  and  360  support other components  310 ,  320 ,  330 ,  340  and  350  of the touch screen panel  10 . Each of the first and second substrates  300  and  360  may be implemented as a transparent glass substrate or plastic substrate. 
     The first electrode  310  is formed on the first substrate  300 , and the second electrode  350  is formed beneath the second substrate  360 . The touch screen panel  10  recognizes a user&#39;s touch input according to a change in dielectric constant between the first and second electrodes  310  and  350 , and outputs a coordinate value of the recognized touch input to the process. The first and second electrodes  230  and  250  may be made of a transparent metal. 
     The piezoelectric layer  330  is formed between the first and second electrodes  310  and  350 . The piezoelectric layer  330  is made of a mixture of a piezoelectric material and an elastic deformation material. The piezoelectric layer  330  is electrically connected to the energy recovery device  20 . If a user&#39;s touch input is applied, the piezoelectric layer  330  converts mechanical energy of the touch input into electrical energy according to characteristics of the piezoelectric material, and supplies the converted electrical energy to the energy recovery device  20 . The piezoelectric layer  330  restores deformation of the touch screen panel, caused by the user&#39;s touch input, according to elastic deformation characteristics. 
     The piezoelectric layer  330  and the first electrode  310  are electrically insulated from each other, and the piezoelectric layer  330  and the second electrode  350  are electrically insulated from each other. To this end, the touch screen panel  10  may include a first insulation layer  320  formed between the piezoelectric layer  330  and the first electrode  310 , and a second insulation layer  340  formed between the piezoelectric layer  330  and the second electrode  350 . The piezoelectric layer  330  continuously extends across the entire area of the touch screen panel  10 , or at least continuously extends across the display area of the touch screen panel  10 . 
     The substrates  100 ,  160 ,  200 ,  260 ,  300  and  360 , the electrodes  110 ,  150 ,  230 ,  250 ,  310  and  350 , the insulation layers  120 ,  140 ,  220 ,  320  and  340 , the piezoelectric layers  130 ,  210  and  330 , and the elastic deformation layer  240  may be made of a flexible material. That is, the touch screen panel  10  according to this embodiment may have flexibility. 
     The energy recovery system according to an embodiment converts mechanical energy of a touch input to a touch screen panel into electrical energy and stores the converted electrical energy, thereby increasing the operating time of a mobile device. 
     Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.