Abstract:
An exemplary burning system ( 20 ) for a liquid crystal display includes a VGA (video graphics array) interface ( 230 ), a DVI (digital visual interface) ( 240 ), an interface-inverting circuit ( 220 ) configured for selectively switching between connectivity with the VGA interface and connectivity with the DVI, and a host computer ( 250 ) including a print interface ( 210 ). The host computer is configured for burning extended display identification data for the VGA interface into the liquid crystal display via the print interface, the interface-inverting circuit and the VGA interface, and is configured for burning extended display identification data for the DVI into the liquid crystal display via the print interface, the interface-inverting circuit and the DVI.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a burning system including a print interface for a liquid crystal display. 
     GENERAL BACKGROUND 
     Liquid crystal displays (LCDs) are commonly used as displays for compact electronic apparatuses. This is because LCDs not only provide good quality images with little power, but they are also very thin. A liquid crystal display, generally, includes a video graphics array (VGA) interface or a digital visual interface (DVI). A high-grade liquid crystal display may include both the VGA interface and the DVI. 
     The VGA interface and the DVI can both communicate with a host computer via a display data channel (DDC), which is a communication channel between the host computer and the liquid crystal display. Each mass manufactured liquid crystal display is provided with a set of standard identification data called extended display identification data (EDID). EDID contains information such as manufacturer details, a timing sequence of the liquid crystal display, and maximum image sizes and color performances of the liquid crystal display. This data must be burned into the liquid crystal display before the DDC can be used. 
     Physical parameters of the VGA interface are generally different from those of the DVI. Likewise, the EDID for the VGA interface is, generally, different from that for the DVI. Due to these differences, typically, the EDID for the VGA interface and the EDID for the DVI are burned into each liquid crystal display at two different workstations of a mass production line. The liquid crystal display must be transported between the two workstations. This process requires suitable transportation equipment, and can be time-consuming. The efficiency of manufacturing the liquid crystal display is limited, and the cost of manufacturing the liquid crystal display is correspondingly high. 
     What is needed, therefore, is a burning system for a liquid crystal display that can overcome the above-described deficiencies. 
     SUMMARY 
     In one preferred embodiment, a burning system for a liquid crystal display includes a VGA (video graphics array) interface, a DVI (digital visual interface), an interface-inverting circuit configured for selectively switching between connectivity with the VGA interface and connectivity with the DVI, and a host computer including a print interface. The host computer is configured for burning extended display identification data for the VGA interface into the liquid crystal display via the print interface, the interface-inverting circuit and the VGA interface, and is configured for burning extended display identification data for the DVI into the liquid crystal display via the print interface, the interface-inverting circuit and the DVI. 
     Other novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of at least one embodiment of the present invention. In the drawings, like reference numerals designate corresponding parts throughout various views and all the views are schematic. 
         FIG. 1  is a block diagram of a burning system for a liquid crystal display according to a first embodiment of the present invention. 
         FIG. 2  is a block diagram of a burning system for a liquid crystal display according to a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made to the drawings to describe the present invention in detail. 
     Referring to  FIG. 1 , a burning system  10  for a liquid crystal display (not shown) according to a first embodiment of the present invention is shown. The burning system  10  includes a host computer  150  having a print interface  110 , a connection cable (not shown), a VGA interface  130  and a DVI  140 . In a typical arrangement incorporating the burning system  10 , the connection cable physically interconnects a first socket (not shown) of the host computer  150  and a second socket (not shown) and a third socket (not shown) of the liquid crystal display. The first socket represents the print interface  110  of the host computer  150 , the second socket represents the VGA interface  130  of the liquid crystal display, and the third socket represents the DVI  140  of the liquid crystal display. 
     A burning program of the host computer  150  can burn EDID for the VGA interface  130  into the liquid crystal display via the print interface  110 , the connection cable and the VGA interface  130  under an inter-integrated circuit (I 2 C) bus protocol. The burning program of the host computer  150  can, also, burn the EDID for the DVI  140  into the liquid crystal display via the print interface  110  and the DVI  140  under the I 2 C bus protocol. The I 2 C bus protocol, generally, transmits a serial clock pulse via a serial clock line (SCL) and transmits serial data via a serial data line (SDL). In an alternative embodiment, the burning program for burning the EDID for the VGA interface  130  and the burning program for burning the EDID for the DVI  140  can be different programs. 
     The print interface  110  includes: a pin P 14 , serving as a first serial data output terminal  111 ; a pin P 1 , serving as a second serial data output terminal  115 ; a pin P 3 , serving as a first serial clock pulse output terminal  113 ; and a pin P 2 , serving as a second serial clock pulse output terminal  117 . 
     The VGA interface  130  includes: a pin P 12 , serving as a first serial data input terminal  131 ; and a pin P 15 , serving as a first serial clock pulse input terminal  133 . The DVI  140  includes: a pin P 7 , serving as a second serial data input terminal  141 ; and a pin P 6 , serving as a second serial clock pulse input terminal  143 . 
     The first serial data output terminal  111  of the print interface  110  is connected to the first serial data input terminal  131  of the VGA interface  130 . The first serial clock pulse output terminal  113  of the print interface  110  is connected to the first serial clock pulse input terminal  133  of the VGA interface  130 . The second serial data output terminal  115  of the print interface  110  is connected to the second serial data input terminal  141  of the DVI  140 . The second serial clock pulse output terminal  117  of the print interface  110  is connected to the second serial clock pulse input terminal  143  of the DVI  140 . 
     With the above-described configuration, the host computer  150  burns the EDID for the VGA interface  130  and the EDID for the DVI  140  into the liquid crystal display via the print interface  110 , the connection cable, and the respective VGA interface  130  and DVI  140 . That is, the EDID for the VGA interface  130  and the EDID for the DVI  140  can be burned into the liquid crystal display at a single workstation of a mass production line. Unlike in a conventional burning process, there is no need for time-consuming transportation of the liquid crystal display between two different workstations. The efficiency of manufacturing the liquid crystal display is improved, and the cost of manufacturing the liquid crystal display is correspondingly reduced. 
     A method for burning the EDID for the VGA interface  130  and the EDID for the DVI  140  into the liquid crystal display can include: first, burning the EDID for the VGA interface  130  into the liquid crystal display via the print interface  110 , the connection cable and the VGA interface  130 ; and second, burning the EDID for the DVI  140  into the liquid crystal display via the print interface  110 , the connection cable and the DVI  140 . In an alternative embodiment, the method for burning the EDID for the VGA interface  130  and the EDID for the DVI  140  into the liquid crystal display can include: first, burning the EDID for the DVI  140  into the liquid crystal display via the print interface  110 , the connection cable and the DVI  140 ; and second, burning the EDID for the VGA interface  130  into the liquid crystal display via the print interface  110 , the connection cable and the VGA interface  130 . 
     Referring to  FIG. 2 , a burning system  20  for a liquid crystal display (not shown) according to a second embodiment of the present invention is shown. Except as may be indicated to the contrary below, a typical arrangement incorporating the burning system  20  is similar to the above-described typical arrangement incorporating the burning system  10 . The burning system  20  includes a host computer  250  having a print interface  210 , an interface-inverting circuit  220 , a VGA interface  230 , a DVI  240  and a control circuit  260 . 
     The print interface  210  includes: a pin P 9 , serving as a serial data output terminal  211 ; a pin P 17 , serving as a serial clock pulse output terminal  213 ; and a pin P 6  and a pin P 7 , which cooperatively serve as a control signal output terminal  215 . 
     The VGA interface  230  includes: a pin P 12 , serving as a first serial data input terminal  231 ; and a pin P 15 , serving as a first serial clock pulse input terminal  233 . The DVI  240  includes: a pin P 7 , serving as a second serial data input terminal  241 ; and a pin P 6 , serving as a second serial clock pulse input terminal  243 . 
     The interface-inverting circuit  220  includes a switching unit  221 , a first transistor  223  and a second transistor  225 . In one embodiment, the switching unit  221  can be a 74HC4053 chip. The switching unit  221  includes a first input terminal  2211 , a second input terminal  2212 , a channel switching input terminal  2213 , a first output terminal  2214  connected to the first serial data input terminal  231 , a second output terminal  2215  connected to the first serial clock pulse input terminal  233 , a third output terminal  2216  connected to the second serial data input terminal  241 , and a fourth output terminal  2217  connected to the second serial clock pulse input terminal  243 . 
     The first transistor  223  includes: a base connected to the serial data output terminal  211 ; an emitter that is grounded; and a collector connected to the first input terminal  2211  of the switching unit  221 . The second transistor  225  includes: a base connected to the serial clock pulse output terminal  213 ; an emitter that is grounded; and a collector connected to the second input terminal  2212  of the switching unit  221 . 
     The control circuit  260  includes a third transistor  261 , a resistor  263 , and a five-volt power supply. The third transistor  261  includes: a base connected to the control signal output terminal  215 ; an emitter that is grounded; and a collector connected to the five-volt power supply via the resistor  263 . The collector of the third transistor  261  is also connected to the channel switching input terminal  2213  of the switching unit  221 . 
     In operation, the control signal output terminal  215  of the print interface  210  provides a high voltage to the base of the third transistor  261  of the control circuit  260  to switch on the third transistor  261 . The channel switching input terminal  2213  of the switching unit  221  is grounded via the collector and the emitter of the third transistor  261 . The switching unit  221  is thus switched to the VGA interface  230 . 
     The serial data output terminal  211  of the print interface  210  burns serial data for the VGA interface  230  into the liquid crystal display via the first transistor  223  and the VGA interface  230 . The serial clock pulse output terminal  213  of the print interface  210  burns a serial clock pulse for the VGA interface  230  into the liquid crystal display via the second transistor  225  and the VGA interface  230 . 
     The control signal output terminal  215  of the print interface  210  provides a low voltage to the base of the third transistor  261  of the control circuit  260  to switch off the third transistor  261 . A five-volt voltage is applied to the channel switching input terminal  2213  of the switching unit  221 . Thus, the switching unit  221  is switched to the DVI  240 . 
     The serial data output terminal  211  of the print interface  210  burns serial data for the DVI  240  into the liquid crystal display via the first transistor  223  and the DVI  240 . The serial clock pulse output terminal  213  of the print interface  210  burns a serial clock pulse for the DVI  240  into the liquid crystal display via the second transistor  225  and the DVI  240 . The burning system  20  can achieve advantages similar to those described above in relation to the burning system  10 . 
     A method for burning the EDID for the VGA interface  230  and burning the EDID for the DVI  240  into the liquid crystal display can include the following steps. First, the interface-inverting circuit  220  is switched to the VGA interface  230 . Second, the EDID for the VGA interface  230  is burned into the liquid crystal display via the print interface  210 , the interface-inverting circuit  220  and the VGA interface  230 . Third, the interface-inverting circuit  220  is switched to the DVI  240 . Fourth, the EDID for the DVI  240  is burned into the liquid crystal display via the print interface  210 , the interface-inverting circuit  220  and the DVI  240 . In an alternative embodiment, the method for burning the EDID for the VGA interface  230  and the EDID for the DVI  240  into the liquid crystal display can include the following steps. First, the interface-inverting circuit  220  is switched to the DVI  240 . Second, the EDID for the DVI  240  is burned into the liquid crystal display via the print interface  210 , the interface-inverting circuit  220  and the DVI  240 . Third, the interface-inverting circuit  220  is switched to the VGA interface  230 . Fourth, the EDID for the VGA interface  230  is burned into the liquid crystal display via the print interface  210 , the interface-inverting circuit  220  and the VGA interface  230 . 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit or scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being exemplary embodiments of the invention.