Patent Publication Number: US-2009231232-A1

Title: External graphic display adapter for express card computer system

Description:
BACKGROUND  
     This disclosure relates generally to portable computers. More particularly, the present disclosure relates to utilizing multiple monitors with a single portable computer. 
     Portable computers, such as notebook and tablet computers, have become increasingly popular. In many cases, users have replaced their conventional desktop computer with a portable computer. This has give rise to a demand for features that have traditionally only been available in a desktop computer. These “short comings” that are intrinsic to portable computers include: 
     1) To be truly portable, the portable computer and its integral display screen are usually relatively small in size. While most portable computers include a port for connecting a larger external monitor, this port is generally a VGA port that may not provide a very high resolution is certainly not digital. 
     2) Conventional portable computers only provide outputs to two display devices, the integral portable computer display screen and an external monitor connected to the VGA port. Many environments exist in which it is desirable to be able to display data to a number of screens or to display different data to a number of screens from a single location. This data might include video, graphics, text etc. or a mixture of these formats. 
     3) The graphics controller in a conventional portable computer may be relatively slow to desktop computers, especially for an older portable computer. Portable computer design does not allow for upgrading the graphics controller in the manner of a desktop computer. 
     SUMMARY  
     There is provided a display adapter for a portable computer comprising an interface module for insertion into an ExpressCard slot of the portable computer. A video output connection may be connected to a display device. A graphic controller is in communication with the interface module, without any bridge integrated circuit between the graphic controller and the interface module, and the video output connection. The graphic controller receives display input signals from the portable computer, generates display command signals corresponding to the display input signals, and transmits the display command signals to any display device connected to the video output connection. 
     The display output port is default as a DVI-I connector, with the graphic controller being a dual graphic controller generating digital and analog display command signals and transmitting the display command signals to the DVI-I connector. However, it may also include any combination of DVI, VGA, TV and any latest display interface such as DisplayPort 
     The display adapter may further comprise a dual display cable having an input cable that receives the display command signals from the DVI-I connector, a first output cable that transmits the digital display command signals, and a second output cable having a filter separating the digital display command signals from the analog display command signals and transmitting the analog display command signals. 
     The display adapter may further comprise a connection for an external power source. 
     The display adapter may further comprise an active cooler assembly having a heatsink and a fan, with the heatsink being thermally connected to the graphic controller ASIC. 
     The graphic controller is a native graphic controller and the display adapter does not include a bridge IC and circuit for connecting the graphic controller to interface of the portable computer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       The present disclosure may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which: 
         FIG. 1  is perspective view of a display adapter in accordance with the disclosure; 
         FIG. 2  is a top view of the display adapter of  FIG. 1 ; 
         FIG. 3  is a schematic diagram of the adapter of  FIG. 1 ; 
         FIG. 4  is a schematic diagram of the display output configuration; 
         FIG. 5  is a schematic diagram of the adapter connecting two video displays to a portable computer. 
     
    
    
     DETAILED DESCRIPTION  
     With reference to the drawings wherein like numerals represent like parts throughout the several figures, a display adapter in accordance with the present disclosure is generally designated by the numeral  10 . The display adapter  10  provides many of the advantages of a desktop computer environment, while maintaining the portability of a portable computer. 
     With reference to  FIGS. 1 and 2 , the display adapter  10  complies with the ExpressCard™ specifications. In the embodiment shown in  FIGS. 1 and 2 , the display adapter  10  has a length  12  of 150 mm. A first end portion  14  has a computer interface module  16  complying with the ExpressCard™  54  form factor, for insertion into a corresponding slot in the portable computer. To ensure compatibility with the slots included with conventional portable computers, the first end portion  14  has a width  18  of 54 mm and a thickness  20  of 5 mm. To ensure that the 26 pin connector  22  at the proximal end of the first end portion  14  engages the mating connector of the portable computer, the first end portion  14  has a length  24  of 76 mm. The second end portion  26  includes a conventional DVI-I connector  28  at the distal end  30 . The distal end  30  of the second end portion  26  may also include a television output or display port connection  32 . In the embodiment of  FIG. 1 , the second end portion  26  has a width  34  of 75 mm. 
     With reference to  FIG. 3 , the display adaptor  10  includes an application specific integrated circuit (ASIC) graphic controller  36  with two display engines  38 ,  40  and at least one memory  42 . The graphic controller  36  may be a native graphic controller that connects to the ExpressCard™ interface  44  of the portable computer  46  via connector  22  and the mating connector of the portable computer  46  without any bridge IC in between. The graphic controller  36  receives display input signals from the portable computer  46  via the interface module  16 , generates digital and analog display command signals corresponding to the display input signals with the display engines  38  and  40 , and transmits the display command signals to display devices  48  connected to the video output connections  28 ,  32 . Due to the power supply limits imposed by the ExpressCard™ specifications, the display adapter  10  requires an external power source  50 . Accordingly, the display adapter  10  includes a connector  52  for receiving power from an external power supply or a USB cable. An active cooler assembly  54  having a heatsink  56  and a fan  58  is mounted to the top of the graphic controller  36  inside the display adaptor housing  60  with the heatsink  56  thermally connected to the graphic controller  36 . The heat removed by the cooler assembly  54  is exhaust through ventilation openings  62  in the adapter housing  60 . 
     With reference to  FIG. 4 , the DVI-I output connector  28  and the television output or display port connector  32  support several different methods for connecting displays  48  to the display adapter  10 . The DVI-I output connector  28  may be connected  63  to the DVI-d input  64  of a digital display device  48 , providing one additional display. The DVI-I output connector  28  may be connected  67  to an analogue display  48  device using a DVI dongle  66  that separates the digital display command signals from the analog display command signals and transmits the analog display command signals, providing one additional display. With additional reference to  FIG. 5 , two additional displays  48  may be simultaneously connected by a dual display cable  68  to the DVI-I output connector  28 . A digital display device  48  is connected to the cable  68  by a digital DVI-d input and an analogue display device  48  is connected to the cable  68  by a VGA input. Another display device  48  may be connected to the television output or display port connection  32  while a second display  48  device is simultaneously connected to the DVI-I output connector  28 . This second display device  48  may be a digital device connected by a DVI-d input connector  68  or an analogue device connected by a DVI dongle  66 . 
     Using the dual display cable  68  or the DVI-I output connector  28  and the television output connector  32 , along with the portable computer external video output  70  allows three external video displays  48  to be connected to the portable computer  46 . This gives a grand total of four displays including the portable computer&#39;s integral display  72 . As shown in  FIG. 5 , with the suitable display drivers, it&#39;s possible to choose between a unified screen space or a true multiple head solution compatible with any kind of multi display application. 
     It should be appreciated that the display adapter  10  provides a high performance graphic solution for portable computers through the ExpressCard™ slot that is available in such computers. The display adapter  10  supports enhanced multi-display function, transforming the portable computer  46  into a multi display workstation. The display adapter  10  has a dual link DVI connector  28  supporting the highest resolution found in the newest display devices  48 . The display adapter  10  has a very small form factor and a light weight design providing high mobility. The display adapter  10  supports both Window XP and Vista. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.