Patent Publication Number: US-2003234779-A1

Title: Display apparatus with a storage unit mounted on a signal transmission component externally of a display device

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The invention relates to a display apparatus, more particularly to a display apparatus with a storage unit that is mounted on a signal transmission component externally of a display device.  
       [0003] 2. Description of the Related Art  
       [0004] Presently, the primary communications interface between a display apparatus and a computer video card is the display data channel (DDC), which supports the plug-and-play function. The DDC standard was set up by the Video Electronic Standards Association (VESA) to define a series of digital signals transmitted by a display apparatus to a computer video card. The digital signals include basic product identification, basic parameters, display specifications, etc. When the computer video card receives these data, it will automatically process the information and render the optimum screen resolution for the display apparatus.  
       [0005] Since the DDC information includes identification data of the display apparatus, such as the manufacturer&#39;s name, product serial number, manufacturing date, etc, its content may vary among individual display apparatus. The DDC information is usually stored in a memory chip mounted inside the display apparatus. However, in consideration of certain factors, such as whether the display apparatus involved will pass quality control, the ex-factory date, etc., the DDC information cannot be finalized until production of the display apparatus has been completed, i.e. the assembly and quality control operations have been concluded. In view of the foregoing, almost all manufacturers currently provide the DDC information in two stages. First, a memory chip for storing the DDC information is mounted in every display apparatus during assembly. Then, after the assembly and quality control operations have been successfully concluded, the display apparatus are connected in sequence via a cable to a programming module for storing the DDC information in the memory chip. The cable is removed upon completion of the programming operation. The tasks of attaching and detaching the cable to the display apparatus and the actual programming operation are laborious and time consuming, and are often the cause of bottleneck in the manufacturing process.  
       [0006] Therefore, if memory chips can be programmed with the DDC information externally of the display apparatus beforehand, then they can be programmed simultaneously in batches using a set of programming modules instead of being individually programmed inside each display apparatus, thereby saving a lot of time in the process of programming the DDC information. Yet this measure results in another undesirable flaw. Particularly, if programmed memory chips are already mounted inside the display apparatus before quality inspection, and it turned out that there are defective display apparatus that must be discarded, an unfavorable situation will arise in that the DDC information of the display apparatus may no longer be in order, i.e. the product serial numbers are non-consecutive as a result of the discarded display apparatus. To avoid the aforesaid situation, the only alternative is to mount the programmed memory chips after inspection. This, however, involves the task of dismantling the housing of each display apparatus before the corresponding memory chip can be mounted. The dismantling process is tedious and time consuming, and the time saved by batch programming may be offset or even exceeded by the dismantling task. This is the reason why few manufacturers opt to use pre-programmed memory chips in the manufacture of the display apparatus.  
       [0007] Although the memory chip carrying the DDC information is assembled onto a circuit board of the display apparatus, in practice, the DDC information is only provided for use by the computer video card when tuning the display apparatus and is actually irrelevant to the basic functionality of the display apparatus. In other words, without a memory chip carrying the DDC information, the display apparatus can still function normally.  
       [0008] Therefore, as long as a memory chip carrying the DDC information can be electrically connected to a computer video card, it is desirable to find a way for mounting the memory chip externally of a display device such that memory chips can be programmed beforehand in batches and such that the housings of assembled and inspected display apparatus need not be dismantled when installing the programmed memory chips, thereby simplifying the manufacturing flow and reducing the manufacturing time.  
       SUMMARY OF THE INVENTION  
       [0009] Therefore, the main object of the present invention is to provide a display apparatus that can overcome the aforesaid drawbacks associated with the prior art.  
       [0010] Accordingly, a display apparatus of this invention is adapted for use with a display circuit and comprises:  
       [0011] a display device for receiving and processing image signals from the display circuit and for rendering images thereon; and  
       [0012] a signal transmission component including a storage unit and a plurality of transmission routes, the signal transmission component having a first end adapted to be coupled detachably to the display circuit and a second end coupled to the display device, the storage unit storing display data channel information corresponding to the display device therein, a first portion of the transmission routes having one end connected electrically to the storage unit and the other end extending to the first end of the signal transmission component so that the display data channel information stored in the storage unit can be retrieved by the display circuit, a second portion of the transmission routes extending from the first end to the second end of the signal transmission component so as to permit signal transmission between the display circuit and the display device. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0013] Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:  
     [0014]FIG. 1 is a schematic circuit block diagram showing a preferred embodiment of a display apparatus according to the present invention;  
     [0015]FIG. 2 is a schematic view showing the preferred embodiment of a display apparatus according to the present invention; and  
     [0016]FIG. 3 is a fragmentary schematic diagram of a signal transmission component of the preferred embodiment of a display apparatus according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0017] Referring to FIG. 1, the preferred embodiment of a display apparatus  30  according to this invention is adapted to receive external image signals from a device with a display circuit  41  that is capable of image signal processing, such as a computer  40  (see FIG. 2) with a computer video card (not shown) mounted therein. The display apparatus  30  comprises a display device  31  for receiving and processing the image signals from the display circuit  41  and for rendering images thereon in a known manner, and a signal transmission component  32 , such as a signal cable that is electrically connected to the display device  31  and that is capable of transmitting the image signals from the display circuit  41  to the display device  31  and DDC information from the display apparatus  30  to the display circuit  41 .  
     [0018] In view of the drawbacks of programming the DDC information into the assembled display device, and of installing a programmed memory chip that contains the DDC information into the assembled display device, the present invention contemplates installation of a programmed storage unit  325 , such as a memory chip, that contains the DDC information externally of the display device  31 . To this end, it is noted that the signal transmission component  32  is usually coupled to the display device  31  in the final stage of the manufacturing process. Therefore, the present invention teaches the integration of the storage unit  325  into the signal transmission component  32  in lieu of the display device  31  to overcome the drawbacks of the prior art.  
     [0019] As best shown in FIG. 1, a first end  321  of the signal transmission component  32  of the preferred embodiment of a display apparatus  30  according to this invention is detachably coupled to the display circuit  41 , whereas a second end  322  of the signal transmission component  32  is coupled to the display device  31 . The signal transmission component  32  includes a transmission route group  327  and the storage unit  325  that contains the DDC information corresponding to the display device  31 . In order to enable the display circuit  41  to retrieve the DDC information stored in the storage unit  325 , the transmission route group  327  includes a set of first transmission routes  323 , each having one end connected electrically to the storage unit  325  and the other end extending to the first end  321  of the signal transmission component  32 . Furthermore, in order to permit signal transmission between the display device  31  and the display circuit  41 , the transmission route group  327  further includes a set of second transmission routes  324 , each extending from the first end  321  to the second end  322  of the signal transmission component  32 .  
     [0020] There are four DDC standards currently available: DDC1, DDC2B, DDC2B+ and DDC2AB. It is noted that the number and individual functions of the first transmission routes  323  may vary slightly according to the DDC standard that is in use. Furthermore, the first end  321  of the signal transmission component  32  is usually terminated by an electrical connector  3210  that can be plugged to the display circuit  41 . The electrical connector  3210  may be a Mini-D-Sub connector having fifteen pins arranged in three rows, a D-Sub connector having fifteen pins arranged in two rows, a BNC connector (used in PS/2, Power MAC, WS), a universal serial bus (USB) connector, etc.  
     [0021] Referring further to FIG. 3, the display apparatus  30  of this invention is exemplified as one that adopts the DDC1 standard, and that includes a Mini-D-Sub electrical connector  3210  that terminates the first end  321  of the signal transmission component  32  and that is provided with fifteen conductive terminals, each of which is connected to a respective one of the transmission routes  323 ,  324 . The storage unit  325  is in the form of 8-pin memory chip. The pin configuration of the electrical connector  3210  is shown in the following table:  
                                   Pin   Function                                        1   Red signal       2   Green signal       3   Blue signal       4   No connection       5   No connection       6   Red signal grounding       7   Green signal grounding       8   Blue signal grounding       9   VS =+ 5 power supply       10   No connection       11   Ground       12   SDA (for plug-and-play)       13   Horizontal sync       14   Vertical sync &amp; P&amp;P       15   SCL (for P&amp;P sync)                  
 
     [0022] According to the DDC1 standard, data signals are transmitted using two data and timing transmission routes, and vertical synchronization signals are also required. As shown in the above table, pins  12 ,  14  and  15  are relevant to the DDC1 standard, wherein pin  12  (SDA) is used to transmit the DDC information, such as manufacturer&#39;s name, product model name, serial number, screen resolution, etc., of the display apparatus  30 . Pin  14  (VSYNC) is used to transmit vertical synchronization signals. Pin  15  (SCL) is used to transmit DDC timing pulse signals. Therefore, the storage unit  325  of this embodiment has three terminals sda, vclk and scl corresponding and connected to pins  12 ,  14  and  15  of the electrical connector  3210 . Furthermore, when the electrical connector  3210  is plugged to the display circuit  41 , pin  9  (VS) will be fed with +5V from the display circuit  41 . Since the terminal vdd of the storage unit  325  is electrically connected to pin  9  (VS) of the electrical connector  3210 , the storage unit  325  can thus receive power from the display circuit  41 . Therefore, when the first end  321  of the signal transmission component  32  is electrically connected to the display circuit  41 , through the first transmission routes  323 , the display circuit  41  can provide power to the storage unit  325  via pin  9  (VS), and can retrieve the DDC information from the storage unit  325  via pins  12  (SDA) and  15  (SCL).  
     [0023] Moreover, as shown in the above table, pins  1 ,  2 ,  3 ,  6 ,  7 ,  8 ,  11 ,  13  and  14  of the electrical connector  321  correspond to the second transmission routes  324  for transmitting image signals from the display circuit  41  to the display device  31  via the signal transmission component  32 . Note that pin  14  (VSYNC) is shared by both the first and second transmission routes  323 ,  324  as it is electrically connected to both the storage unit  325  and the display device  31 . The pins of the electrical connector  3210  and the terminals of the storage unit  325  that are not in use may be connected to any one of pins  6 ,  7 ,  8  and  11  of the electrical connector  3210  so as to ground the same. In actual practice, power may be provided to the storage unit  325  by the display device  31  instead of the display circuit  41 . Moreover, when the DDC standard used by the display apparatus  30  is other than the DDC1 standard, such as the DDC2B standard, the DDC signals are still transmitted using two data and timing transmission routes, but vertical synchronization signals are not required. It is thus apparent from the foregoing that the present invention can be applied to different DDC standards and can use different types of electrical connectors  3210 .  
     [0024] When the present invention is applied to the manufacture of a specific batch of display apparatus  30 , display devices  31  and signal transmission components  32  integrated with programmed storage units  325  that contain the DDC information can be separately manufactured in batch. Then, for those display devices  31  that passed inspection, the corresponding signal transmission component  32  can be secured thereto. As compared to the aforementioned prior art, programming of the storage units  325  can be quickly and conveniently conducted in the present invention. Moreover, the signal transmission components  32  and the display devices  31  can be simultaneously manufactured in the present invention. It is therefore apparent that the present invention can reduce production time and can thus overcomes the aforesaid drawbacks of the prior art.  
     [0025] It should be also noted that, although the storage unit  325  containing the DDC information is directly mounted to the signal transmission component  32  in the foregoing embodiment, the main essence of this invention resides in the provision of the storage unit  325  externally of the display device  31 . It is not essential to integrate the storage unit  325  into the signal transmission component  32 . For instance, the storage unit  325  can be mounted in an adaptor connected between the second end  322  of the signal transmission component  32  and the display device  31 .  
     [0026] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.