Abstract:
A touchpad keyboard includes a microprocessor; a touchpad module comprising a flexible, rectangular, optically transmissive touchpad and a touchpad controller electrically interconnecting the touchpad and the microprocessor; and an electronic paper (e-paper) display module comprising a flexible, rectangular e-paper display disposed under the touchpad, and an e-paper display controller electrically interconnecting the e-paper display and the microprocessor. The e-paper display includes a plurality of selection keys, each selection key being adapted to cause the microprocessor to access one of a plurality of keyboard layout pages to display on the e-paper display in response to pressing thereon.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The invention relates to keyboards and more particularly to a touchpad keyboard having an electronic paper (e-paper) display with improved characteristics. 
         [0003]    2. Description of Related Art 
         [0004]    Touchscreens and touchpads as input devices are becoming increasingly popular in the fields of computers, cellular phones, etc. because of their ease and versatility of operation. For example, touchpad allows a user to make selections and move a cursor on the screen by simply moving one finger thereon. It is similar to computer mouse operation. 
         [0005]    Typically, a character printing membrane of a touchpad of a touchpad keyboard is provided with a plurality of virtual keys each printed with a character, number, or function number. In short, the characters printing membrane is fixedly formed on the touchpad. There many different keyboard layouts arise because different people need easy access to different symbols. In one example, this is because they are inputting text in different languages, i.e., so-called national layouts. Following is a description of an example: A business person may travel between Taiwan and Spain. He or she may bring a laptop computer having a touchpad as a personal belonging when travelling. He or she may have the need of inputting text in Chinese when in Taiwan and inputting text in Spanish when in Spain. However, as discussed above the characters printing membrane is fixedly formed on the touchpad of the laptop computer. Hence, the person has to buy two laptop computers of different national layouts (i.e., Spanish keyboard layout and Chinese keyboard layout) in which the laptop computer with Spanish keyboard layout will be carried when traveling to Spain and the laptop computer with Chinese keyboard layout will be used when in Taiwan. Further, in some situations the person may have to carry both laptop computers when traveling to Spain. This is very inconvenient. 
         [0006]    Thus, it is desirable of providing a touchpad keyboard with an electronic paper display so that a user may switch between at least two different national layouts by simply pressing a switching device of the touchpad keyboard of, for example, a laptop computer. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore one object of the invention to provide a touchpad keyboard having an e-paper display so that a user may press one of a plurality of selection keys thereon to access a desired national layout to display on the e-paper display. 
         [0008]    To achieve the above and other objects, the invention provides a touchpad keyboard comprising a microprocessor; a touchpad module comprising a flexible, rectangular, optically transmissive touchpad and a touchpad controller electrically interconnecting the touchpad and the microprocessor; and an e-paper display module comprising a flexible, rectangular e-paper display disposed under the touchpad, and an e-paper display controller electrically interconnecting the e-paper display and the microprocessor, wherein the e-paper display comprises a plurality of selection keys, each selection key being adapted to cause the microprocessor to access one of a plurality of keyboard layout pages to display on the e-paper display in response to pressing thereon. 
         [0009]    The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is an exploded view of a touchpad keyboard according to a first preferred embodiment of the invention; 
           [0011]      FIG. 2  is a block diagram of an e-paper display incorporated in the touchpad keyboard; 
           [0012]      FIG. 3  is a block diagram of the e-paper display module of  FIG. 2 ; 
           [0013]      FIG. 4  is an enlarged view of a portion of the e-paper display of  FIG. 1 ; 
           [0014]      FIG. 5  is an exploded view of a touchpad keyboard according to a second preferred embodiment of the invention; 
           [0015]      FIG. 6  is a block diagram of an e-paper display incorporated in the touchpad keyboard of  FIG. 5 ; and 
           [0016]      FIG. 7  is a longitudinal sectional view of the opaque touchpad of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to  FIGS. 1 to 4 , a touchpad keyboard in accordance with a first preferred embodiment of the invention comprises the following components as discussed in detail below. 
         [0018]    A touchpad module  10  comprises a flexible, rectangular, optically transmissive touchpad  101  and a touchpad controller  102 . The touchpad  101  comprises a top ITO glass and a bottom ITO film separated by a plurality of spacers therebetween. Touchpad is a well known device so that a detailed description thereof is omitted herein for the sake of brevity. The touchpad controller  102  is electrically interconnected the touchpad  101  and a microprocessor  30  which is in turn electrically connected to a host computer. The touchpad controller  102  is capable of converting an analog signal generated by pressing the touchpad  101  by a user into a digital signal, calculating position of the finger touch in the form of coordinate position, converting the coordinate position into a touch signal, and sending the touch signal containing the coordinate position to the microprocessor  30  via a serial bus, thereby effecting a touchpad input. A loudspeaker or a vibrator (both not shown) can be activated when the touch signal is created so as to either audibly or physically alert the user about the successful touch. 
         [0019]    An electronic paper (e-paper) display module  20  comprises a flexible, rectangular e-paper display  201  and an e-paper display controller  202 . The e-paper display  201  is provided under the touchpad  101 . The e-paper display controller  202  comprises a display micro-controller  2021  electrically connected to the microprocessor  30  for controlling display signals of the e-paper display  201 , a driver chip  2022  for sending the display signals from the display micro-controller  2021  to the e-paper display  201 , an SRAM (static random access memory)  2023  for storing a plurality of pages of different layouts, and a power supply  2024  controlled by the display micro-controller  2021  for supplying power to the driver chip  2022 . 
         [0020]    The e-paper display  201  is implemented as an electrophoretic display and can form visible images by rearranging charged pigment particles using an applied electric field. In a simplest implementation of an electrophoretic display, titanium dioxide particles approximately one micrometer in diameter are dispersed in hydrocarbon oil. A dark-colored dye is also added to the oil, along with surfactants and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates separated by a gap of 10 to 100 micrometres. When a voltage is applied across the two plates, the particles will migrate electrophoretically to the plate bearing the opposite charge from that on the particles. When the particles are located at the front viewing side of the display, it appears white, because light is scattered back to the viewer by the high-index titanium particles. When the particles are located at the rear side of the display, it appears dark, because the incident light is absorbed by the colored dye. If the rear electrode is divided into a number of pixels, then an image can be formed by applying the appropriate voltage to each region of the display to create a pattern of reflecting and absorbing regions. E-paper displays have the potential to be more comfortable to read than conventional displays. This is due to the stable image, which does not need to be refreshed constantly, the wider viewing angle, and the fact that it reflects ambient light rather than emitting its own light. An e-paper display can be read in direct sunlight without the image appearing to fade. 
         [0021]    On the left top corner of the e-paper display  201 , there are provided two selection keys  201   a,    201   b.  A user may press one of the selection keys  201   a,    201   b  to activate the microprocessor  30  to access a desired layout (i.e., national layout) from the SRAM  2023  to display on the e-paper display  201 . 
         [0022]    The microprocessor  30  is electrically connected the touchpad controller  102  and the e-paper display controller  202 . Further, the microprocessor  30  is electrically connected to a host computer. 
         [0023]    The flexible touchpad  101  is provided on the flexible e-paper display  201  which is in turn provided on a flexible, insulative bottom base  40 . The bottom base  40  thus serves to support the touchpad keyboard. 
         [0024]    Referring to  FIGS. 5 to 7 , a touchpad keyboard in accordance with a second preferred embodiment of the invention is shown. The characteristics of the second preferred embodiment (i.e., the differences between the first and second preferred embodiments) are detailed below. 
         [0025]    The optically transmissive touchpad is replaced by an opaque touchpad  105  which is disposed between the e-paper display  201  and the bottom base  40 . In addition to the flexible, rectangular, opaque touchpad  105 , the touchpad module  10  further comprises a touchpad controller  102 . A user may press one of a plurality of keys on the e-paper display  201  for keying and inputting computer commands. The portion of the opaque touchpad  105  corresponding to the pressing is thus depressed and activated. The opaque touchpad  105  is a resistive touchpad and comprises, from top to bottom, a top substrate  1051  formed of PET (polyethylene terephthalate), a first conduction layer  1052  adhered to the top substrate  1051 , a first sensing layer  1053  formed of sensing material and adhered to the first conduction layer  1052 , the first sensing layer  1053  projecting downward, a second sensing layer  1054  formed of sensing materials and spaced apart from the first sensing layer  1053  by a distance, a second conduction layer  1055  adhered to the second sensing layer  1054 , and a bottom substrate  1058  formed of PET. 
         [0026]    Between the first conduction layer  1052  and the second conduction layer  1055 , there are provided a plurality of posts  1057  as spacers. The post  1057  has a bottom end adhered to the second conduction layer  1055  and a top end secured to the first conduction layer  1052  by means of an adhesive layer  1056 . The posts  1057  and the first sensing layers  1053  are arranged transversely in alternating fashion. 
         [0027]    The touchpad controller  102  is capable of converting an analog signal generated by pressing the opaque touchpad  105  by a user into a digital signal, calculating position of the finger touch in the form of coordinate position, converting the coordinate position into a touch signal, and sending the touch signal containing the coordinate position to the microprocessor  30  via a serial bus, thereby effecting a touchpad input. 
         [0028]    Preferably, the touchpad keyboard is either rigid as a typical keyboard or flexible for ease of transport. 
         [0029]    Preferably, the touchpad keyboard can be connected to a desktop computer, a laptop computer, or any of other electronic appliances as character and command input device. 
         [0030]    Advantages and characteristics of the invention are described below. The touchpad keyboard comprises a touchpad module  10 , an electronic paper (e-paper) display module  20 , and a microprocessor  30 . The touchpad module  10  comprises a flexible, rectangular, optically transmissive touchpad  101  and a touchpad controller  102 . The e-paper display module  20  comprises a flexible, rectangular e-paper display  201  and an e-paper display controller  202 . The e-paper display  201  is provided under the touchpad  101 . On the e-paper display  201 , there are provided two selection keys  201   a,    201   b.  A user may press one of the selection keys  201   a,    201   b  to access a desired layout (i.e., national layout) from the memory to display on the e-paper display  201 . Images shown on the e-paper display  201  are not required to be refreshed constantly, i.e., energy saving. The e-paper display  201  can be read clearly without the image appearing to fade. 
         [0031]    While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.