Patent Publication Number: US-2013249802-A1

Title: Touch keyboard

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 61/614,753 entitled “Multi-Touch Sensor based Keyboard with Multi-Modal Touch Feedback Functions” filed Mar. 23, 2012, the contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a keyboard, and more particularly to a touch keyboard. 
     BACKGROUND OF THE INVENTION 
     Recently, the multi-touch input technology applied to a tablet computer has been introduced to a virtual keyboard or a touch keyboard in a personal computer market. However, due to the lack of the tactile feedback under the environment of the virtual keyboard, the key touch feel of the virtual keyboard is usually insufficient. In other words, the virtual keyboard fails to provide a user-friendly interface. For solving the above drawbacks, when a tablet computer is used to do paperwork or other typing work, the tablet computer is usually equipped with an additional standard keyboard (e.g. a keyboard with mechanical keys). 
     The additional standard keyboard for the tablet computer is similar to the conventional keyboard. For example, the additional standard keyboard is thick and has bulky hardware components. Because of hardware design properties of the conventional keyboard, many users pointed out that the current keyboard is not suitably placed within the carrying case of the tablet computer. Under this circumstance, it is troublesome to carry the keyboard for the tablet computer. 
     Therefore, there is a need of providing a thin and lightweight keyboard for a tablet computer. 
     SUMMARY OF THE INVENTION 
     The present invention provides a thin touch keyboard. 
     In accordance with an aspect of the present invention, there is provided a touch keyboard. The touch keyboard includes an overlay frame, a touch pad, and a feedback device. The overlay frame includes plural openings. The touch pad is disposed under the overlay frame. When the touch pad is touched through one of the plural openings, the touch pad generates a key signal. The feedback device is disposed under the overlay frame for generating a feedback signal in response to the key signal. 
     In an embodiment, the touch pad is disposed over the feedback device. 
     In an embodiment, the touch pad is disposed under the feedback device. 
     In an embodiment, the touch pad is a capacitive touch pad or a resistive touch pad. 
     In an embodiment, the feedback device is a piezo actuator. 
     In an embodiment, the feedback device further includes a speaker. 
     In an embodiment, the feedback device includes a feedback region. 
     In an embodiment, the feedback device includes plural feedback regions. 
     In an embodiment, the plural feedback regions are arranged along a horizontal direction. 
     In an embodiment, the plural feedback regions are arranged along a vertical direction. 
     In an embodiment, each of the plural feedback regions has a short side and a long hypotenuse, wherein an included angle is formed between the short side and the long hypotenuse. 
     In an embodiment, every two openings are separated from each other by a notch. 
     In an embodiment, the overlay frame further includes plural non-conductive slices. Each opening has an inner wall. Moreover, each of the non-conductive slices is disposed on the inner wall of the corresponding opening. 
     In an embodiment, the non-conductive slices are elastic rings. 
     In an embodiment, the touch keyboard includes a non-conductive plate, and the non-conductive plate is disposed under the overlay frame. The non-conductive plate includes plural perforations and plural bulges. Each of the plural perforation has an inner wall, and each of the plural bulges is disposed on the inner wall of the corresponding perforation. The plural perforations are aligned with the plural openings of the overlay frame, respectively. 
     In an embodiment, the overlay frame is made of a non-conductive material. 
     In an embodiment, the plural openings of the overlay frame are rectangular openings or circular openings. 
     In an embodiment, the touch keyboard further includes a base plate, and the base plate is disposed under the touch pad and the feedback device. The base plate includes a sliding groove, and the sliding groove is disposed on a lateral edge of the base plate for accommodating the overlay frame. 
     The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view illustrating a touch keyboard according to a first embodiment of the present invention; 
         FIG. 2A  is a schematic exploded view illustrating a touch keyboard according to a second embodiment of the present invention; 
         FIG. 2B  is a schematic cross-sectional view illustrating the touch keyboard according to the second embodiment of the present invention; 
         FIG. 3  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a third embodiment of the present invention; 
         FIG. 4A  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a fourth embodiment of the present invention; 
         FIG. 4B  is a schematic cross-sectional view illustrating the touch keyboard according to the fourth embodiment of the present invention; 
         FIG. 5A  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a fifth embodiment of the present invention; 
         FIG. 5B  is a schematic top view illustrating a ring-shaped non-conductive slice of the touch keyboard of  FIG. 5A ; 
         FIGS. 5C-5E  are schematic top views illustrating some variants of the ring-shaped non-conductive slice of the touch keyboard of  FIG. 5A ; 
         FIG. 5F  is a schematic exploded view illustrating a touch keyboard according to a sixth embodiment of the present invention; 
         FIGS. 6A and 6B  schematically illustrate the actions of a piezo actuator used in the touch keyboard of the present invention; 
         FIG. 7  schematically illustrates the layout of a US standard keyboard; 
         FIG. 8  is a schematic top view illustrating the feedback regions of a feedback device of a touch keyboard according to a seventh embodiment of the present invention; 
         FIGS. 9A-9D  are schematic top views illustrating some variants of the feedback regions of the feedback device used in the touch keyboard of the present invention; 
         FIG. 9E  is a schematic exploded view illustrating a touch keyboard according to an eighth embodiment of the present invention; 
         FIG. 10  is a schematic top view illustrating a touch keyboard according to a ninth embodiment of the present invention; and 
         FIG. 11  is a schematic functional block illustrating a touch keyboard according to a tenth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Multi-Modal Touch Feedback Generation by Overlay Frame and Piezo Actuator 
     The present invention provides a novel keyboard design. The keyboard of the present invention is a thin and lightweight touch keyboard with multi-modal touch feedback. The touch keyboard provides plural touch feedback mechanisms for correctly generating keystrokes. The hardware components of the touch keyboard comprises (i) a touch pad such as a multi-touch pad (e.g. a capacitive touch pad or a resistive touch pad); and (ii) a feedback device (e.g. a piezo actuator) disposed under or over the touch pad for generating mechanical vibration on the surface of the touch pad; and (iii) an overlay frame disposed over the touch pad for providing a tactile feedback to the user&#39;s fingertip. 
     Hardware Structure and its Usage 
       FIG. 1  is a schematic perspective view illustrating a touch keyboard according to a first embodiment of the present invention. As shown in  FIG. 1 , the touch keyboard  10  comprises an overlay frame  11 , a multi-touch pad  12 , and four independent piezo actuators  13   a ,  13   b ,  13   c  and  13   d . The piezo actuators  13   a ,  13   b ,  13   c  and  13   d  are used for generating mechanical vibration on the surfaces of pre-defined touch pad regions corresponding to the piezo actuators  13   a ,  13   b ,  13   c  and  13   d , respectively. The overlay frame  11  comprises plural openings  111 . The overlay frame  11  is disposed over the multi-touch pad  12  for providing a tactile feedback function. When the user&#39;s fingertip is placed in an opening  111 , which is equivalent to a keycap area, the position of the fingertip is detected by the multi-touch pad  12 . According to a two-dimensional position of the user&#39;s fingertip, the multi-touch pad  12  generates a key signal. Moreover, the piezo actuators  13   a ,  13   b ,  13   c  and  13   d  are arranged between the overlay frame  11  and the multi-touch pad  12 . In response to the key signal, a corresponding one of the piezo actuators  13   a ,  13   b ,  13   c  and  13   d  is driven to generate a feedback signal. In an embodiment, the multi-touch pad  12  of the touch keyboard  10  is a capacitive touch pad for converting the capacitance change into the two-dimensional coordinates of the fingertip position. In another embodiment, the multi-touch pad  12  of the touch keyboard  10  is a resistive touch pad for converting the electrical resistance into the two-dimensional coordinates of the fingertip position. The examples of the multi-touch pad  12  are presented herein for purpose of illustration and description only. According to the tactile sensation provided by the overlay frame  11  and the feedback signal (e.g. mechanical vibration) provided by the piezo actuators  13   a ,  13   b ,  13   c  and  13   d , the user can sense the keystrokes of the touch keyboard  10  in order to correctly execute the typing activities. 
     A touch keyboard according to a second embodiment of the present invention will be illustrated as follows.  FIG. 2A  is a schematic exploded view illustrating a touch keyboard according to a second embodiment of the present invention.  FIG. 2B  is a schematic cross-sectional view illustrating the touch keyboard according to the second embodiment of the present invention. As shown in  FIGS. 2A and 2B , the touch keyboard  20  comprises an overlay frame  21 , a touch pad  22 , a feedback device  23 , and a base plate  24 . The overlay frame  21  is disposed over the touch pad  22  and covers the touch pad  22 . The feedback device  23  is disposed under the touch pad  22 . When the touch pad  22  is touched, a key signal is generated by the touch pad  22 . In response to the key signal, the feedback device  23  generates a feedback signal. The feedback device  23  comprises a feedback region  231 . When the feedback signal is generated by the feedback device  23 , the user who touches the feedback region  231  can sense the keystrokes of the touch keyboard  20  according to the feedback signal. The base plate  24  is disposed under the touch pad  22  and the feedback device  23 . 
     The base plate  24  comprises a sliding groove  241  and a receiving space  242 . The sliding groove  241  is located at a lateral edge of the base plate  24  for accommodating the overlay frame  21 . Moreover, the overlay frame  21  is slidable relative to the base plate  24 . The receiving space  242  is used for accommodating the touch pad  22  and the feedback device  23 . Depending on the keyboard languages, the layouts of the overlay frame  21  are different. According to the requirement of the keyboard language, the overlay frame  21  may be replaced. After the overlay frame  21  is replaced with a new one, the sequence and the number of the openings of the overlay frame  21  are changed. 
     In this embodiment, the overlay frame  21  is a rigid plate that is made of a non-conductive material. Moreover, the overlay frame  21  has many rectangular openings  211 . Like the keycaps of the conventional keyboard, the rectangular openings  211  have the functions of guiding the user&#39;s fingers. Moreover, the sizes of the rectangular openings  211  of the overlay frame  21  may be different, but are not limited thereto. As shown in  FIG. 2A , the area of the rectangular opening  211   a  is smaller than the area of the rectangular opening  211   b . The larger rectangular opening  211   b  may be aligned with a numeric keypad region or a cursor controlling region of the touch keyboard  20 . 
     Other exemplary overlay frames of the touch keyboard of the present invention will be illustrated as follows.  FIG. 3  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a third embodiment of the present invention. As shown in  FIG. 3 , the overlay frame  31  is a rigid plate with plural circular openings  311 . Like the keycaps of the conventional keyboard, the circular openings  311  have the functions of guiding the user&#39;s fingers. Moreover, the overlay frame  31  has plural notches  312 . Every two adjacent openings  311  are separated from each other by a notch  312 . These notches  312  are collaboratively defined as plural rectangular boundaries for enclosing the openings  311 . Consequently, each opening  311  and the adjacent notches  312  are equivalent to a keycap area of the conventional keyboard. The opening  311  and the adjacent notches  312  are used for providing the tactile feedback of a virtual keycap on the touch keyboard. In this embodiment, the notches  312  are V-shaped notches, but are not limited thereto. 
     Please refer to  FIGS. 4A and 4B .  FIG. 4A  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a fourth embodiment of the present invention. The overlay frame  41  comprises plural openings  411  and plural non-conductive slices  412 . Each opening  411  comprises an inner wall  413 . The non-conductive slice  412  is disposed on the inner wall  413  (e.g. a portion of an inner circumference of the opening  411 ) for resting the user&#39;s finger. In this embodiment, the non-conductive slices  412  are rigid structures, but are not limited thereto. 
       FIG. 4B  is a schematic cross-sectional view illustrating the touch keyboard according to the fourth embodiment of the present invention. In this embodiment, the touch keyboard  40  comprises an overlay frame  41 , the plural non-conductive slices  412 , a touch pad  42 , and a feedback device  43 . The touch pad  42  is disposed under the overlay frame  41  for generating a key signal. The feedback device  43  is disposed under the touch pad  42  for generating a feedback signal. 
     The structures and functions of the touch pad  42  and the feedback device  43  of the touch keyboard of the fourth embodiment are similar to those of the above embodiments, and are not redundantly described herein. As shown in  FIG. 4B , the touch keyboard  40  has the non-conductive slices  412  for comfortably placing and resting the user&#39;s fingers thereon. Moreover, due to the non-conductive slices  412 , when the fingertip is ready to execute the typing activity, the possibility of accidentally touching the touch pad  42  to erroneously generate the key signal will be minimized. 
       FIG. 5A  is a schematic partial perspective view illustrating an overlay frame of a touch keyboard according to a fifth embodiment of the present invention. The overlay frame  51  comprises plural ring-shaped non-conductive slices  52  and plural openings  53 . Each opening  53  has an inner wall  531  (e.g. an inner circumference of the opening  53 ). In this embodiment, the ring-shaped non-conductive slices  52  are elastic rings. 
       FIG. 5B  is a schematic top view illustrating a ring-shaped non-conductive slice of the touch keyboard of  FIG. 5A .  FIGS. 5C-5E  are schematic top views illustrating some variants of the ring-shaped non-conductive slice of the touch keyboard of  FIG. 5A . Depending on the sizes of the user&#39;s fingers and the user&#39;s preferences, the ring-shaped non-conductive slices  52 ,  52   a ,  52   b  and  52   c  with different shapes may be selected. Moreover, these ring-shaped non-conductive slices  52 ,  52   a ,  52   b  and  52   c  may be easily replaced by any other non-conductive slices with desired shapes. 
       FIG. 5F  is a schematic exploded view illustrating a touch keyboard according to a sixth embodiment of the present invention. As shown in  FIG. 5F , the touch keyboard  60  comprises an overlay frame  61 , a touch pad  62 , a feedback device  63 , and a non-conductive plate  64 . The touch pad  62  is disposed under the overlay frame  61 . The feedback device  63  is disposed under the touch pad  62 . 
     The non-conductive plate  64  is disposed under the overlay frame  61 , and arranged between the overlay frame  61  and the touch pad  62 . The touch pad  62  and the feedback device  63  are covered by the non-conductive plate  64 . Instead of installing the ring-shaped non-conductive slices  52  of  FIG. 5A , the non-conductive plate  64  can be used to define the keycap areas of the touch keyboard. The non-conductive plate  64  comprises plural perforations  641  and plural bulges  642 . Each perforation  641  has an inner wall  643 . The bulge  642  is disposed on the inner wall  643  of a corresponding perforation  641  for resting the user&#39;s fingers and preventing from accidentally touching the touch pad  62 . Each perforation  641  is aligned with a corresponding opening  611  of the overlay frame  61 . In this embodiment, the perforations  641  and the bulges  642  of the non-conductive plate  64  are directly located under the corresponding openings  611  of the overlay frame  61 , respectively. 
       FIGS. 6A and 6B  schematically illustrate the actions of a piezo actuator used in the touch keyboard of the present invention. The piezo actuator  70  may be operated in a released status A and a deformed status B. In response to a change of an electric voltage, the piezo actuator  70  is subjected to deformation, and the status of the piezo actuator  70  is changed. Consequently, the piezo actuator  70  generates vibration. The operating principles of the piezo actuator  70  are well known to those skilled in the art and widely applied to the electronic component market, and are not redundantly described herein. 
       FIG. 7  schematically illustrates the layout of a US standard keyboard. According to the keycap arrangement, the US standard keyboard may be divided into nine regions Z 1 , Z 2 , Z 3 , Z 4 , Z 5 , Z 6 , Z 7 , Z 8  and Z 9  corresponding to the thumbs, the index fingers, the middle fingers, the ring fingers and the little fingers of the both hands of the user. For enhancing the identification of the keys, the positions of the touch pad or the feedback device corresponding to the key F and the key J may have distinctive surface textures in order to enhance the distinctive tactile feel. The distinctive surface textures are made of different materials or structures or covered by a special material. For example, the distinctive surface textures are salient points or friction-enhancing structures, but are not limited thereto. 
       FIG. 8  is a schematic top view illustrating the feedback regions of a feedback device of a touch keyboard according to a seventh embodiment of the present invention. As shown in  FIG. 8 , the feedback device  81  comprises nine piezo actuators (not shown) corresponding to the feedback regions  81   a ,  81   b ,  81   c ,  81   d ,  81   e ,  81   f ,  81   g ,  81   h  and  81   i  in order to provide feedback signals to the feedback regions  81   a ,  81   b ,  81   c ,  81   d ,  81   e ,  81   f ,  81   g ,  81   h  and  81   i , respectively. The feedback regions  81   a ,  81   b ,  81   c ,  81   d ,  81   e ,  81   f ,  81   g ,  81   h  and  81   i  are correlated with different fingers of the user. Each feedback region (e.g. the feedback region  81   a ) has a short side R 1  and a long hypotenuse R 2 . In this embodiment, an included angle θ is formed between the short side R 1  and the long hypotenuse R 2 . In this embodiment, the included angle θ is an obtuse angle. According to the vibration of the piezo actuator and the tap input sensitivity of the touch pad (not shown), each of the feedback regions  81   a ,  81   b ,  81   c ,  81   d ,  81   e ,  81   f ,  81   g ,  81   h  and  81   i  can provide vibration to the corresponding fingers (e.g. the thumbs, the index fingers, the middle fingers, the ring fingers or the little fingers). 
     Consequently, the touch keyboard using the feedback device  81  can provide a highly reliable user interface similar to a conventional keyboard. Since the nine piezo actuators provide different feedback signals, feedback device  81  can provide intuitive feedback for allowing the user to confirm whether the user&#39;s fingers correctly touch the keycap areas of the touch keyboard. If a resistive touch pad is selected as the touch pad of the touch keyboard, the pressure data about the user&#39;s fingers are detected by the resistive touch pad. The pressure data about the user&#39;s fingers may be used for precisely tuning the tap sensitivity of the touch keyboard and judging the user&#39;s intention of the typing activity. Alternatively, the pressure data about the user&#39;s fingers may be used to determine a threshold value of judging the user&#39;s intention of the typing activity. Moreover, the pressure data about the user&#39;s fingers may be used to discriminate whether the user tries to push the virtual key of the touch keyboard down or just keep on resting the fingers on the surface of touch pad. 
       FIGS. 9A-9D  are schematic top views illustrating some variants of the feedback regions of the feedback device used in the touch keyboard of the present invention. As shown in  FIG. 9A , the feedback device  82  comprises nine feedback regions  82   a ,  82   b ,  82   c ,  82   d ,  82   e ,  82   f ,  82   g ,  82   h  and  82   i . The layout of the nine feedback regions  82   a ,  82   b ,  82   c ,  82   d ,  82   e ,  82   f ,  82   g ,  82   h  and  82   i  is similar to the keycap arrangement of the US standard keyboard of  FIG. 7 . 
       FIGS. 9B and 9C  are simplified versions to provide four to five independent feedback regions for generating the feedback signals. As shown in  FIG. 9B , the feedback device  83  comprises five feedback regions  83   a ,  83   b ,  83   c ,  83   d  and  83   e . As shown in  FIG. 9C , the feedback device  84  comprises four feedback regions  84   a ,  84   b ,  84   c  and  84   d . Moreover, the four feedback regions  84   a ,  84   b ,  84   c  and  84   d  are arranged along a vertical direction. As shown in  FIG. 9D , the feedback device  85  comprises five rows of feedback regions  85   a ,  85   b ,  85   c ,  85   d  and  85   e . That is, these feedback regions  85   a ,  85   b ,  85   c ,  85   d  and  85   e  are arranged along a horizontal direction. The optimal configuration of the feedback regions may be determined according to the usability tests, the manufacturing complexity and the cost of touch keyboard. 
       FIG. 9E  is a schematic exploded view illustrating a touch keyboard according to an eighth embodiment of the present invention. As shown in  FIG. 9E , the touch keyboard  90  comprises an overlay frame  91 , a touch pad  92 , and plural feedback devices  93 . The feedback devices  93  are arranged between the overlay frame  91  and the touch pad  92 . The feedback devices  93  have respective feedback regions  93   a ,  93   b ,  93   c  and  93   d . These feedback regions  93   a ,  93   b ,  93   c  and  93   d  are not interfered from each other. Consequently, the feedback regions  93   a ,  93   b ,  93   c  and  93   d  may be used to generate multiple keystrokes and result in simultaneous haptic response signals. Moreover, these haptic response signals do not have to be cooperative because the typing action by each finger is always an independent input action. As shown in  FIG. 9E , the touch keyboard  90  comprises four independent feedback devices  93 . Each of the feedback devices  93  comprises two piezo actuators  931 . These four feedback devices  93  provide vibration tactile feedback corresponding to the detection of finger touch on touch keyboard  90 . 
       FIG. 10  is a schematic top view illustrating a touch keyboard according to a ninth embodiment of the present invention. As shown in  FIG. 10 , the touch keyboard  94  further comprises a speaker  95 . The speaker  95  is installed on a surface of the touch keyboard  94  for generating a directive typing sound. Moreover, the speaker  95  may create different typing sounds corresponding to respective feedback regions. For example, the touch keyboard  94  has five independent feedback regions (not shown), the touch keyboard  94  can generate five different emulated key sounds. Moreover, the speaker  95  for generating the directive typing sounds is a special sound-generation device that can propagate the sound wave within a limited angle range. Consequently, only the user can hear the directive typing sound. 
     Firmware Structure and Host Support Software 
       FIG. 11  is a schematic functional block illustrating a touch keyboard according to a tenth embodiment of the present invention. As shown in  FIG. 11 , the touch keyboard  96  comprises two directive speakers  97 , a touch pad  98 , and a microchip and firmware C. The directive speakers  97  are used for generating directive typing sounds. The touch pad  98  is used for sensing the user&#39;s fingers. The microchip and firmware C is used for managing the keystrokes and the feedback signals, and outputting a USB keyboard data to a tablet computer, a host computer or any other electronic device. Moreover, the firmware defines a logical device of a conventional USB keyboard. The firmware executes the following computational tasks in a real-time manner: (1) recognition of the finger touch and identification of the absolute position of the finger touch in the local two-dimensional coordinates on the touch pad  98 , (2) activation of the feedback signal (e.g. the piezo vibration) corresponding to the pre-defined feedback regions of current touch, (3) activation of emulated keystroke sound corresponding to the pre-defined feedback regions of the current touch, (4) conversion of the data packets including absolute touch position into pre-defined keystroke data packets; and (5) generation of USB keyboard data packets and sending the USB keyboard data packets to the computer host. 
     From the above descriptions, the present invention provides a touch keyboard. The touch keyboard comprises an overlay frame, a touch pad, and a feedback device. The touch pad and the feedback device are disposed under the overlay frame. The overlay frame comprises plural openings for providing the keystrokes of the touch keyboard. When the user&#39;s finger is penetrated through a corresponding opening to touch the touch pad, the touch pad generates a key signal, and the feedback device generates a feedback signal to the user. Consequently, the touch keyboard provides a user-friendly interface. The touch keyboard of the present invention is thin and lightweight, and is easily carried. Moreover, due to the keystrokes provided by the overlay frame and the feedback device, the touch keyboard of the present invention is easily acceptable by the user. Consequently, the comfort of using the touch keyboard is enhanced. 
     While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.