Abstract:
A display device having a display matrix including a pixel border of width x and located around the edge locations of the matrix for improved viewability. In particular, the border can be several pixels wide, e.g., 1&lt;x&lt;5. In one embodiment, the border is two pixels wide and surrounds a liquid crystal display (LCD) matrix area in which images are generated from a frame buffer memory. In one embodiment, the pixels of the border are “dummy pixels” each containing a red, a green and a blue subpixel. Each subpixel has a color filter and is manufactured with a “dummy” transistor which operates to fix open the subpixels thereby allowing a predetermined amount of “white” color brightness through the dummy pixels. In one implementation, the brightness amount is approximately 80–95 percent of the saturation brightness for the display screen. The pixel border is useful for increasing viewability of characters that are displayed along the edge of the LCD matrix area in which images are generated from a frame buffer memory. The pixel border is particularly useful for these edge displayed characters when the background color is white and the characters are generated using a non-white color. The pixel border is also advantageous in that it can be used with conventional character generation processes of the operating system of the computer used to drive the display screen. In one embodiment, the novel display can be used within a portable computer system or other portable electronic device.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of display screen technology. More specifically, embodiments of the present invention relate to flat panel display screens that are useful in conjunction with portable electronic devices. 
     2. Related Art 
     As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. One of the new categories of computer systems is the “palmtop” computer system. A palmtop computer system is a computer that is small enough to be held in the hand of a user and can therefore be “palm-sized.” Most palmtop computer systems are used to implement various Personal Information Management (PIM) applications such as an address book, a daily organizer and electronic notepads, to name a few. Palmtop computers with PIM software have been know as Personal Digital Assistants (PDAs). Many PDAs have a small and flat display screen associated therewith. 
     In addition to PDAs, small flat display screens have also been implemented within other portable electronic devices, such as cell phones, electronic pagers, remote control devices and other wireless portable devices. 
     Liquid crystal display (LCD) technology, as well as other flat panel display technologies, have been used to implement many of the small flat display screens used in portable electronic devices. These display screens contain a matrix of pixels, with each pixel containing subpixels for color displays. Some of the displays, e.g., color displays, use a back lighting element for projecting light through an LCD matrix. Other displays, e.g., black and white, use light reflectivity to create images through the LCD matrix and these displays do not need back lighting elements when used in lit surroundings. Whether color or in black and white, because the displays used in portable electronic devices are relatively small in area, every pixel is typically needed and used by the operating system in order to create displays and present information to the user. Additionally, because the display device is typically integrated together with the other elements of the portable electronic device, the operating systems of the portable electronic devices typically expect the display unit to have a standard pixel dimension, e.g., an (m×n) array of pixels. 
       FIG. 1A  illustrates a typical black and white display screen having a standard size pixel matrix  20  with an exemplary edge-displayed character thereon. The edge-displayed character is the letter “A” and is displayed at the left hand side of the display screen at an arbitrary height. The technology could be either transmissive or reflective liquid crystal display (LCD). In the black and white display screen, the background pixels  26  are typically light, e.g., not very dark, and the pixels  24  that make up the edge-displayed character are typically dark. The edge location  28  of the display screen, e.g., between the edge of the matrix  20  and the bezel  22  of the portable electronic device, is typically the same color as the background pixels  26 . Therefore, the left edge of the edge-displayed character, “A,” has good contrast and is therefore easily viewed by the user. This is the case regardless of the particular edge used, e.g., left, right, up, down, because region  28  surrounds the matrix  20 . 
       FIG. 1B  illustrates a typical color display screen having a pixel matrix  20 ′ with the same edge-displayed character thereon. The display screen could be an LCD having thin film transistor (TFT) technology. The edge-displayed character is the letter “A” and is displayed at the left hand side of the display screen at an arbitrary height. In this format, the background pixels  26  are typically light, e.g., because of the back lighting element, and the pixels  24  that make up the edge-displayed character are typically dark. However, importantly, the edge location  28  of the display screen, e.g., between the edge of the color matrix  20 ′ and the bezel  22  of the portable electronic device, is typically dark. Being dark, the edge region  28  is the same or similar color as the pixels  24  that make up the character. Therefore, the left edge of the edge-displayed character, “A,” has very poor contrast and is therefore typically lost as illustrated in  FIG. 1B . This makes reading the edge displayed character very difficult for a user. This is the case regardless of the particular edge used, e.g., left, right, up, down, because region  28  surrounds the color matrix  20 ′. 
     In an attempt to address this problem, some computer systems do not display edge-located characters to avoid the contrast problems associated with the screen edge. Many desktop computer systems, for example, simply try to avoid the display of edge-located characters on the cathode ray tube (CRT) screen or on a large flat panel display. However, this solution is not acceptable in the case of a small display screen where every pixel is needed for image and information presentation. What is needed is a display that makes maximal use of the available screen pixels while eliminating the problems associated with edge displayed characters in any display format where the pixels of the character are of the same or similar color as the edge region  28 . What is also needed is a solution that is also compatible with standard display screen dimensions and formats. 
     SUMMARY OF THE INVENTION 
     Accordingly, embodiments of the present invention provide an electronic device, e.g., a cell phone, PDA, electronic pager, etc., having a screen that makes maximal use of the available screen pixels while eliminating the problems associated with edge displayed characters in any display format where the pixels of the character are of the same or similar color as the edge region. Embodiments provide the above benefits while being compatible with standard display screen sizes and formats. Embodiments of the present invention therefore provide a small display screen with improve viewability, especially at the edge locations. The present invention provides these advantages and others not specifically mentioned above but described in the sections to follow. 
     A display device is described herein having a display matrix including a pixel border of width x and located around the edge locations of the display matrix for improved viewability. In particular, the border can be several pixels wide, e.g., 1&lt;x&lt;5. In one embodiment, the border is two pixels wide and surrounds a liquid crystal display (LCD) matrix area in which images are generated from a frame buffer memory. In one embodiment, the pixels of the border are “dummy pixels” each containing a red, a green and a blue subpixel. Each subpixel has a respective color filter and is manufactured with a “dummy” transistor which operates to fix open the subpixels thereby allowing a predetermined amount of “white” color brightness through the dummy pixels. In one implementation, the brightness amount is approximately 80–95 percent of the saturation brightness for the display screen. 
     The pixel border is useful for increasing viewability of characters that are displayed along the edge of the LCD matrix area in which images are generated from a frame buffer memory. The pixel border is particularly useful for these edge displayed characters when the background color is of a particular color or shade and the characters are generated using pixels of that same particular color or shade. The pixel border is also advantageous in that it can be used without requiring any changes in the character generation processes of the operating system of the computer used to drive the display screen. In this way, the display advantages of the present invention are compatible with standard circuitry for driving standard displays. In one embodiment, the novel display can be used within a portable computer system or other portable electronic device. 
     More specifically, an embodiment of the present invention includes a portable electronic device comprising: a processor coupled to a bus; a memory unit coupled to the bus; a user input device coupled to the bus; and a display unit coupled to the bus and comprising: a matrix of independently controllable pixels comprising m rows and n columns of discrete pixels, the matrix for generating an image therein by light modulation and wherein the image is representative of information stored in a frame buffer memory; and a pixel border having a predetermined width, the pixel border surrounding the matrix of independently controllable discrete pixels and comprising dummy pixels, wherein each dummy pixel is analogous to a pixel of the matrix but without containing an active transistor. Embodiments include the above and further comprising a back lighting element for illuminating the matrix and the pixel border. 
     Embodiments include the portable electronic device as described above and wherein each pixel of the matrix comprises: a red subpixel having a first active transistor; a green subpixel having a second active transistor; and a blue subpixel having a third active transistor and wherein each dummy pixel of the matrix comprises: a red sub-dummy-pixel; a green sub-dummy-pixel; and a blue sub-dummy-pixel. 
     Embodiments include the portable electronic device as described above wherein the matrix is fabricated using thin film transistor liquid crystal display technology. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  illustrates a display screen of the prior art having an edge displayed character where the background pixels are light and the character is composed of darker pixels. 
         FIG. 1B  illustrates a display screen of the prior art having an edge displayed character in a video format where the pixels of the character are of the same or similar color and shade as the edge region of the display panel. 
         FIG. 2A  is a top side perspective view of an exemplary palmtop computer system that can be used in one embodiment of the present invention. 
         FIG. 2B  is a bottom side perspective view of the exemplary palmtop computer system of  FIG. 2A . 
         FIG. 2C  is another exemplary computer system embodiment 
         FIG. 3  is an exploded view of the components of the exemplary palmtop computer system of  FIG. 2A  and  FIG. 2C . 
         FIG. 4  is a logical block diagram of the exemplary palmtop computer system in accordance with an embodiment of the present invention. 
         FIG. 5  is a front view of the exemplary computer system that can be used within the display screen of the present invention. 
         FIG. 6A  is an exemplary communication network in which the exemplary palmtop computer can be used. 
         FIG. 6B  is a perspective view of a cradle device for connecting the exemplary palmtop computer system to other systems via a communication interface. 
         FIG. 7  illustrates a display screen in accordance with one embodiment of the present invention including a border pixel region and a frame buffer pixel region. 
         FIG. 8  is a block diagram of the display unit in accordance with one embodiment of the present invention. 
         FIG. 9A  is a diagram of a dummy pixel of the border pixel region in accordance with an embodiment of the present invention. 
         FIG. 9B  is a diagram of an active pixel of the frame buffer pixel region in accordance with an embodiment of the present invention. 
         FIG. 10  illustrates the pixel architecture of the display matrix of one embodiment of the present invention including the border pixel region and the frame buffer pixel region. 
         FIG. 11A  is a cross sectional view of the display matrix including a cross sectional view of the pixel border in accordance with an embodiment of the present invention. 
         FIG. 11B  is a cross sectional view of a reflective display matrix including a cross sectional view of the pixel border in accordance with an embodiment of the present invention. 
         FIG. 12  is an exemplary display using the display unit with pixel border in accordance with one embodiment of the present invention and having an edge displayed character in a video format in which the character pixels are of the same or similar color as the edge of the display panel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the present invention, a display matrix having a pixel border of dummy pixels for providing contrast improvement for increased viewability of edge-displayed characters, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details or with equivalents thereof. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. 
     Exemplary Portable Electronic Device Platform 
     Although the display screen of the present invention can be implemented in a variety of different electronic systems such as a pager, a cell phone, a remote control device, etc., one exemplary embodiment includes the integration of the display screen with a portable electronic device.  FIG. 2A  is a perspective illustration of the top face  100   a  of one embodiment of a palmtop computer system that can be used in implementation of the present invention. The top face  100   a  contains the novel display screen  105  surrounded by a bezel or cover. A removable stylus  80  is also shown. The novel display screen  105  contains a transparent touch screen (digitizer) able to register contact between the screen and the tip of the stylus  80 . The novel display screen  105  is described in more detail further below. The stylus  80  can be of any material to make contact with the screen  105 . As shown in  FIG. 2A , the stylus  80  is inserted into a receiving slot or rail  350 . Slot or rail  350  acts to hold the stylus when the computer system  100   a  is not in use. Slot or rail  350  may contain switching devices for automatically powering down and automatically power up computer system  100   a  based on the position of the stylus  80 . The top face  100   a  also contains one or more dedicated and/or programmable buttons  75  for selecting information and causing the computer system to implement functions. The on/off button  95  is also shown. 
       FIG. 2A  also illustrates a handwriting recognition pad or “digitizer” containing two regions  106   a  and  106   b . Region  106   a  is for the drawing of alpha characters therein for automatic recognition (and generally not used for recognizing numeric characters) and region  106   b  is for the drawing of numeric characters therein for automatic recognition (and generally not used for recognizing numeric characters). The stylus  80  is used for stroking a character within one of the regions  106   a  and  106   b . The stroke information is then fed to an internal processor for automatic character recognition. Once characters are recognized, they are typically displayed on the screen  105  for verification and/or modification. 
     The digitizer  160  records both the (x, y) coordinate value of the current location of the stylus and also simultaneously records the pressure that the stylus exerts on the face of the digitizer pad. The coordinate values (spatial information) and pressure data are then output on separate channels for sampling by the processor  101  ( FIG. 5 ). In one implementation, there are roughly 256 different discrete levels of pressure that can be detected by the digitizer  106 . Since the digitizer&#39;s channels are sampled serially by the processor, the stroke spatial data are sampled “pseudo” simultaneously with the associated pressure data. The sampled data is then stored in a memory by the processor  101  ( FIG. 5 ) for later analysis. 
       FIG. 2B  illustrates the bottom side  100   b  of one embodiment of the palmtop computer system. An optional extendible antenna  85  is shown and also a battery storage compartment door  90  is shown. A communication interface  108  is also shown. In one embodiment of the present invention, the serial communication interface  108  is a serial communication port, but could also alternatively be of any of a number of well known communication standards and protocols, e.g., parallel, SCSI, Firewire (IEEE 1394), Ethernet, etc. In  FIG. 2B  is also shown the stylus receiving slot or rail  350 . 
       FIG. 2C  illustrates a front perspective view of another implementation of the palmtop computer system  100   c . As shown, the flat central area is composed of the novel display screen area  105  and a thin silk screen layer material portion  84 . Typically, the silk screen layer material portion  84  is opaque and may contain icons, buttons, images, etc., graphically printed thereon in addition to regions  106   a  and  106   b . The novel display screen area  105  and portion  84  are disposed over a digitizer. 
       FIG. 3  is an exploded view of the exemplary palmtop computer system  100  in accordance with one implementation of the present invention. System  100  contains a front cover  210  having an outline of region  106  and holes  75   a  for receiving buttons  75   b . The novel flat panel display  105  (both liquid crystal display and touch screen in one embodiment) fits into front cover  210 . Any of a number of display technologies can be used, e.g., LCD, FED, plasma, etc., for the flat panel display  105  and having the further details as described below. In one embodiment, the display  105  is a flat panel multi-mode display capable of both monochrome and color display modes. 
     The touch screen can be a digitizer. A battery  215  provides electrical power. Replaceable cells or rechargeable batteries can be used. Well known electronics coupled to the battery  215  can detect the energy level of the battery  215 . This information can be sampled by the computer system  110  ( FIG. 5 ) using well known techniques. The digitizer of  FIG. 3  can be implemented using well known devices, for instance, using the ADS-7846 device by Burr-Brown that provides separate channels for spatial stroke information and pressure information. An optional contrast adjustment (potentiometer)  220  is also shown. On/off button  95  is shown along with an infrared emitter and detector device  64 . A flex circuit  230  is shown along with a PC board  225  containing electronics and logic (e.g., memory, communication bus, processor, etc.) for implementing computer system functionality. The digitizer pad is also included in PC board  225 . A midframe  235  is shown along with stylus  80 . Position adjustable antenna  85  is shown. The midframe  235  contains the stylus receiving slot or rail  350 . 
     A radio receiver/transmitter device  240  is also shown between the midframe and the rear cover  245  of  FIG. 3 . The receiver/transmitter device  240  is coupled to the antenna  85  and also coupled to communicate with the PC board  225 . In one implementation, the Mobitex wireless communication system is used to provide two way communication between system  100  and other networked computers and/or the Internet via a proxy server. In other embodiments, TCP protocol can be used. 
       FIG. 4  illustrates circuitry of computer system  100 , some of which can be implemented on PC board  225 . Computer system  100  includes an address/data bus  99  for communicating information, a central processor  101  coupled with the bus  99  for processing information and instructions, a volatile memory  102  (e.g., random access memory RAM) coupled with the bus  99  for storing information and instructions for the central processor  101  and a non-volatile memory  103  (e.g., read only memory ROM) coupled with the bus  99  for storing static information and instructions for the processor  101 . Computer system  100  also includes an optional data storage device  104  (e.g., memory stick) coupled with the bus  99  for storing information and instructions. Device  104  can be removable. As described above, system  100  also contains the novel display device  105  in accordance with the present invention which is coupled to the bus  99  for displaying information to the computer user. PC board  225  can contain the processor  101 , the bus  99 , the ROM  103  and the RAM  102 . 
     Also included in computer system  100  of  FIG. 4  is an alphanumeric input device  106  which in one implementation is a handwriting recognition pad (“digitizer”) having regions  106   a  and  106   b  ( FIG. 2A ), for instance. Device  106  can communicate information (spatial data and pressure data) and command selections to the central processor  101 . System  100  also includes an optional cursor control or directing device  107  coupled to the bus for communicating user input information and command selections to the central processor  101 . In one implementation, device  107  is a touch screen device incorporated with screen  105 . Device  107  is capable of registering a position on the screen  105  where the stylus makes contact and the pressure of the contact. The display device  105  utilized with the computer system  100  is described in more detail below and may be a liquid crystal device, cathode ray tube (CRT), field emission device (FED, also called flat panel CRT) or other display device suitable for creating graphic images and alphanumeric characters recognizable to the user. 
     Signal communication device  108 , also coupled to bus  99 , can be a serial port for communicating with the cradle  60 . Device  108  can also include an infrared communication port. 
       FIG. 5  is a front view of the exemplary palmtop computer system  100  having an exemplary display within screen  105 . The exemplary display contains one or more graphical user interface elements including a menu bar and selectable on-screen buttons  410 . Buttons on screen  105  can be selected by the user directly tapping on the screen location of the button with stylus  80  as is well known. Also shown are two regions of digitizer  106   a  and  106   b . Region  106   a  is for receiving user stroke data (and pressure data) for alphabet characters, and typically not numeric characters, and region  106   b  is for receiving user stroke data (and pressure data) for numeric data, and typically not for alphabetic characters. Physical buttons  75  are also shown. Although different regions are shown for alphabetic and numeric characters, the device is also operable within a single region that recognizes both alphabetic and numeric characters. 
     It is appreciated that, in one embodiment, the digitizer region  106   a  and  106   b  are separate from the display screen  105  and therefore does not consume any display area. 
       FIG. 6A  illustrates a communication system  50  that can be used in conjunction with the palmtop computer system  100 . System  50  is exemplary and comprises a host computer system  56  which can either be a desktop unit as shown, or, alternatively, can be a laptop system  58 . Optionally, one or more host computer systems can be used within system  50 . Host computer systems  58  and  56  are shown connected to a communication bus  54 , which in one embodiment can be a serial communication bus, but could be of any of a number of well known designs, e.g., a parallel bus, Ethernet Local Area Network (LAN), etc. Optionally, bus  54  can provide communication with the Internet  52  using a number of well known protocols. 
     Importantly, bus  54  is also coupled to a cradle  60  for receiving and initiating communication with a palm top (“palm-sized”) portable computer system  100  of the present invention. Cradle  60  provides an electrical and mechanical communication interface between bus  54  (and anything coupled to bus  54 ) and the computer system  100  for two way communications. Computer system  100  also contains a wireless infrared communication mechanism  64  for sending and receiving information from other devices. 
       FIG. 6B  is a perspective illustration of one embodiment of the cradle  60  for receiving the palmtop computer system  100 . Cradle  60  contains a mechanical and electrical interface  260  for interfacing with serial connection  108  ( FIG. 2B ) of computer system  100  when system  100  is slid into the cradle  60  in an upright position. Once inserted, button  270  can be pressed to initiate two way communication between system  100  and other computer systems coupled to serial communication  265 . 
     Pixel Border of the Present Invention 
       FIG. 7  illustrates a front view of the display screen in accordance with an embodiment of the present invention. The display screen contains two different display regions. Region  314  is the frame buffer pixel region and contains a matrix of pixels oriented in m rows and n columns according to a variety of display dimensions and formats. Region  314  generates an image that is a representation of data stored in a frame buffer memory (also called video memory) of computer system  100 . Although region  314  can have any dimensions, in one embodiment it includes the dimensions of 160 pixels by 160 pixels. The computer system, e.g., the operating system, controls the information that is stored into the frame buffer memory and thereby controls the pixels of region  314 . 
     Surrounding region  314  of  FIG. 7  is a novel pixel border region  312  in accordance with the present invention and having a predetermined pixel width, x. The pixels of the pixel border region  312  are called “dummy” pixels because they do not have a controllable element therein. Although the width is arbitrary, in one embodiment the width is two pixels. The pixel border region  312  of the present invention is not controlled by the frame buffer memory and is useful for giving contrast improvement for the viewability of edge located characters. In this respect, the pixels of the pixel border  312  are generally displayed white to match the background pixel color. Specifically, the pixel border  312  is useful for giving contrast improvement for characters displayed along the edges, e.g., upper, lower, right and left, of region  314 . The total viewing area (in pixels) of the display screen when x=2 is therefore m+4 rows and n+4 columns. 
       FIG. 8  illustrates a logical diagram of the components of the novel display unit  105  in accordance with an embodiment of the present invention. Frame buffer memory  320  contains a bitmapped image for display. This frame buffer is read, periodically, by a display controller  322 . The display controller  322  is well known. Display controller  322  is either coupled directly to a display driver  326  or to a timing generator  324 . Controller  322  generates well known timing signals, such as vertical and horizontal synchronization signals, as well as clocking signals; all required to properly propagate image data into the display drivers  326 . The timing generator  324  is sometimes needed to convert the signals from the controller according to the requirements of the drivers. The display drivers  326  are coupled to active transistors within the display matrix  310 . The display matrix  310  generates images by the modulation of light by discrete pixel elements. The display matrix  310  can be of liquid crystal display (LCD) technology but could also be of any active display technology, such as field emission display (FED) technology or other flat panel display technologies. Although display matrix  310  is coupled to display drivers  326 , it is appreciated that region  312  is not coupled to display drivers because it contains no active elements. 
       FIG. 9A  illustrates an example dummy pixel  312   i  of the pixel border region  312  of the present invention. In one embodiment, the display matrix  310  is an LCD device constructed using thin film transistor (TFT) technology. The dummy pixel is like a conventional pixel of the frame buffer pixel region  314  except the dummy pixel  312   i  does not contain an active element, as indicated by the darkened diamond  340 . The active element can be any number of display elements, including a transistor, a series of diodes or a single diode. Therefore, the dummy pixels are not controlled by the frame buffer memory and are not coupled electrically to the display driver circuits  326  ( FIG. 8 ). In one embodiment, the display is a color display and therefore the dummy pixel  312   i  is comprised of three sub-dummy-pixels including a red sub-dummy-pixel  342   a , a green sub-dummy-pixel  342   b  and a blue sub-dummy-pixel  342   c . Each sub-dummy-pixel  342   a – 342   c  contains a respective color filter. It is appreciated that by not containing an active transistor therein, each of the sub-dummy-pixels  342   a – 342   c  of the dummy pixel  312   i  remain fixed and open thereby allowing light to pass there through creating a white image for the dummy pixel  3121 . Each sub-dummy-pixel contains a respective color filter. 
       FIG. 9B  illustrates a pixel  314   i  of the frame buffer pixel region  314 . In one embodiment, the display is color and therefore pixel  314   i  contains a red subpixel  352   a , a green subpixel  352   b  and a blue subpixel  352   c . Each subpixel contains a respective active element  350 , e.g., transistor, that is controlled by the frame buffer memory, e.g., each transistor  350  is coupled to the display driver circuits  326  ( FIG. 8 ). Like the sub-dummy-pixels  342 , each subpixel  352  also contains a respective color filter. 
       FIG. 10  illustrates an exemplary pixel architecture of the display matrix  310  in accordance with an embodiment of the present invention where x=2 and the display is color. In this embodiment, the left hand side of the pixel border  312  is shown partially with the upper and lower corners displayed. As shown in  FIG. 9A , dummy transistors are darkened. Two columns of dummy pixels are shown  360  along the left side edge. On the top edge, two rows of dummy pixels  362  are also shown and also on the bottom. The dummy pixels  312   i  of the border region  312  surround the frame buffer display region  314 , which contains an array of m rows and n columns of pixels, some of which are shown as  314   i . In one embodiment, there are 160×160 pixels in region  314  and the width of region  312  is two. In this case, the LCD glass has a color filter pattern of 164×1 64 pixels which allow light through from a back light element ( FIG. 11 ). The LCD glass has transistors placed on only the interior 160×160 pixels (region  314 ) which are addressed by the frame buffer memory. In this case, the pixel border  312  remains lit all the time thereby providing a white border. 
       FIG. 11A  illustrates a cross section of the display matrix  310  in accordance with one embodiment of the present invention. The embodiments of the present invention can be applied to transmissive, transreflective and reflective display technologies. In this embodiment, a backlighting element  570 , e.g., a cold cathode fluorescent (CCF) tube or other lighting device, is illustrated adjacent to a rear polarizer layer  560 . An active transistor LCD layer  530  is also shown. The active transistor layer  530  maps to region  314  and may control m rows and n columns of pixels. Region  540  and region  550  correspond to the dummy pixel border  312  and therefore do not contain any transistors thereby always allowing light to pass there through. A color filter pattern  520  is also shown. The color filter pattern  520  is a matrix of (m+2×) by (n+2×) pixels. After the color filter pattern  520 , a front polarizer layer  510  is provided. 
       FIG. 11B  illustrates a cross section of a reflective display matrix  610  in accordance with one embodiment of the present invention. In this embodiment, a reflective thin film transistor layer  620  is used. Layer  620  maps to region  314  and may control m rows and n columns of pixels. Region  640  and region  630  correspond to the dummy pixel border  312  and therefore do not contain any transistors thereby always allowing light to pass there through. An optional frontlight layer  650  can be used and a front polarizer  510  is shown along with a rear polarizer  560 . The color filter pattern  520  is a matrix of (m+2×) by (n+2×) pixels. 
       FIG. 12  illustrates a resultant display in accordance with the present invention using a pixel border of width=2. The pixels  380  of the edge displayed character, “A,” are dark and the background pixels are white in this case, e.g., one exemplary form of a reverse video display format. The edge region  28  of the display panel is dark, e.g., the same or similar color as the pixels  380  of the character. In this exemplary case, the border pixels  312  of the present invention are also white. The total number of pixels in the display  310  are (m+2×) by (n+2×). By providing a white border region  312 , the contrast along the left edge of the character, “A,” is much improved thereby improving viewability of the character. This advantageous result is achieved without any requirement of changing the operating system of the computer because the standard (m×n) pixel region  314  of the display remains unchanged. Furthermore, because the border pixels (dummy pixels) of region  312  are not driven by driver circuitry, standard (m×n) driver circuits and software can be used with the present invention. 
     The preferred embodiment of the present invention, a display matrix having a pixel border of dummy pixels for providing contrast improvement for increased viewability of edge-displayed characters, is thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the below claims.