Patent Publication Number: US-2007115418-A1

Title: Liquid crystal display panel having layout of wires for different driving integrated circuits

Description:
TECHNICAL FIELD  
      The present invention relates to a liquid crystal display (LCD) panel having a layout of wires that allows either of two different driving ICs having two different sizes to be connected to the wires.  
     BACKGROUND  
      An LCD has the advantages of portability, low power consumption, and low radiation, and has been widely used in various portable information products such as notebooks, personal digital assistants (PDAs), video cameras and the like. Furthermore, the LCD is considered by many to have the potential to completely replace CRT (cathode ray tube) monitors and televisions. A main component of an LCD is an LCD panel, which includes a display screen.  
      During a typical process for fabricating an LCD panel, a driving integrated circuit (IC) used for driving the LCD panel is fixed on a glass substrate of the LCD panel by a chip on glass (COG) technique. The LCD panel also includes a layout of wires formed on the substrate, for connecting to the driving IC. Normally, two kinds of driving ICs can be used to drive an LCD panel. One kind has a memory unit with numerous functions for driving the LCD panel. The other kind has no memory unit and is small.  
       FIG. 2  is a schematic, abbreviated, top plan view of certain parts of a typical LCD panel that is configured to have a driving IC without memory. The LCD panel  10  includes a substrate  1 . The substrate  1  includes a driving IC area  2 , a plurality of input wires  5 , and a plurality of output wires  6 . The driving IC area  2  has a plurality of input metal pads  4  arranged in a first row, and a plurality of output metal pads  3  arranged in a second row parallel to the first row. The input metal pads  4  and the output metal pads  3  are used to connect with a driving IC (not shown) that does not have a memory unit. A width of the driving IC is approximately equal to a width WI of the driving IC area  2 . That is, a configuration of the driving IC corresponds to the driving IC area  2 , so that the driving IC can be properly attached on the driving IC area  2 . The output metal pads  3  are connected to a plurality of data lines (not shown) of the LCD panel  10  via the output wires  6  respectively. The input metal pads  4  are connected to a flexible printed circuit board (not shown) of the associated LCD via the input wires  5 .  
       FIG. 3  is a schematic, abbreviated, top plan view of certain parts of a typical LCD panel that is configured to have a driving IC with memory. The LCD panel  20  includes a substrate  11 . The substrate  11  includes a driving IC area  12 , a plurality of input wires  15 , and a plurality of output wires  16 . The driving IC area  12  has a plurality of input metal pads  14  arranged in a first row, and a plurality of output metal pads  13  arranged in a second row parallel to the first row. The input metal pads  14  and the output metal pads  13  are used to connect with a driving IC (not shown) that has a memory unit. The memory unit can, for example, be a random access memory (RAM). A width of the driving IC is approximately equal to a width W 2  of the driving IC area  12  (W 2 &gt;W 1 ). That is, a configuration of the driving IC corresponds to the driving IC area  12 , so that the driving IC can be properly attached on the driving IC area  12 . The output metal pads  13  are connected to a circuit (not shown) of the LCD panel  20  via the output wires  16 . The input metal pads  14  are connected to an associated external circuit (not shown) via the input wires  15 .  
      A driving IC with RAM and a driving IC without RAM can each be used to drive a same LCD panel of an LCD which has a predetermined resolution, such as an LCD with a video graphics array (VGA) or a super video graphics array (SVGA). As seen above, the two different driving ICs have different physical configurations and occupy different amounts of space. Thus mass production of a same LCD panel in two versions corresponding to the two kinds of driving ICs also requires two versions of the LCD panel itself to be made. That is, as seen above, one kind of LCD panel  10  with a certain layout of wires is needed for the driving IC without RAM, and another kind of LCD panel  20  with a certain layout of wires is needed for the driving IC with RAM. This increases the cost of mass production of the LCD.  
      It is desired to provide an LCD which overcomes the above-described deficiencies.  
     SUMMARY  
      In one preferred embodiment, an exemplary LCD panel includes a substrate. The substrate includes a driving IC area configured to be connected to either a first driving IC having a first size or a second driving IC having a second size. The driving IC area includes a plurality of connecting wires, a plurality of first input metal pads, a plurality of second input metal pads, and a plurality of output metal pads. The first input metal pads and the output metal pads are configured for electrical connection with the first driving IC. The second input metal pads and the output metal pads are configured for electrical connection with the second driving IC. The first input metal pads are connected to the second input metal pads via the connecting wires, respectively.  
      Advantages and novel features of the above-described LCD panel will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic, abbreviated, top plan view of certain parts of an LCD panel according to a preferred embodiment of the present invention;  
       FIG. 2  is a schematic, abbreviated, top plan view of certain parts of a conventional LCD panel that is configured to have a driving IC without memory; and  
       FIG. 3  is a schematic, abbreviated, top plan view of certain parts of a conventional LCD panel that is configured to have a driving IC with memory. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       FIG. 1  is a schematic, abbreviated, top plan view of certain parts of an LCD panel according to a preferred embodiment of the present invention. The LCD panel  100  includes a substrate  21 . The substrate  21  includes a driving IC area  22 , a plurality of input wires  25 , a plurality of output wires  26 , and a plurality of connecting wires  28 . The driving IC area  22  has a plurality of first input metal pads  24  arranged in a first row, a plurality of second input metal pads  27  arranged in a second row parallel to the first row, and a plurality of output metal pads  23  arranged in a third row parallel to the first and second rows. The row of first input metal pads  24  is located between the row of second input metal pads  27  and the row of output pads  23 .  
      The output metal pads  23  are connected to a plurality of data lines (not shown) of the LCD panel  100  via the output wires  26 . The first input metal pads  24  are respectively connected to the second input metal pads  27  via the connecting wires  28 . The second input metal pads  27  are connected to a flexible printed circuit board (not shown) of an associated LCD via the input wires  25 .  
      The first input metal pads  24  and the output metal pads  23  are used to connect with a first driving IC (not shown) that does not have a memory unit. The second input metal pads  27  and the output metal pads  23  are used to connect with a second driving IC that has a memory unit. The memory unit can, for example, be a RAM.  
      A first distance spanning the row of first input metal pads  24  and the row of output metal pads  23  is defined as W 1 . A width of the first driving IC is approximately equal to W 1 . A second distance spanning the row of second input metal pads  27  and the row of output metal pads  23  is defined as W 2  (W 2 &gt;W 1 ). A width of the second driving IC is approximately equal to W 2 . That is, a size of the second driving IC is larger than that of the first driving IC.  
      Because the LCD panel  100  includes the driving IC area  22  having the first and second input metal pads  24 ,  27  and the output metal pads  23 , a driving IC with RAM or a driving IC without RAM can be chosen to be fixed on the LCD panel  100 . That is, a selected one of the two kinds of driving ICs can be fixed at a corresponding position on the driving IC area  22 . Unlike with conventional LCD panels, there is no need to make two versions of an LCD panel in order to be able to apply the two kinds of driving ICs. Thus the cost of mass manufacture of the LCD panel  100  having either of the two kinds of driving ICs is reduced.  
      The LCD panel  100  can of course be used for other kinds of driving ICs besides those described above. For example, a first kind of driving IC may have a memory other than a RAM. A second kind of driving IC may also have a memory, albeit one that allows the second kind of driving IC to have a smaller size. Such kind of memory can, for example, be a so-called partial RAM. A first kind of driving IC may have a larger size by reason of another constituent thereof besides a memory. Correspondingly, a second kind of driving IC may lack this constituent.  
      It is to be further understood that even though numerous characteristics and advantages of preferred and exemplary embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.