Au Optronics Corporation

Unipac Optoelectronics Corporation

Unipac Octoelectronics Corp.

Tsung-Pei Chiang

Chun-Ta Chen

A digital liquid crystal display (LCD) driving circuit is provided for driving an LCD to display video images. The LCD driving circuit comprises a digital gamma-correction and inversion circuit for performing a digital gamma-correction process on the digitized video signal and then performing a polarity inversion process on selected lines of the video signal. The digital gamma-correction and inversion circuit is coupled directly to a display memory unit so as to fetch the digitized video signal directly from the display memory unit. A digital-to-analog conversion means is coupled to the digital gamma-correction and inversion circuit for converting the digital output of the digital gamma-correction and inversion circuit into analog form. Further, the LCD driving circuit comprises an LCD timing control circuit, which is coupled to receive a plurality of video control signals associated with the digitized video signal, for converting the video control signals into a LCD timing control signal to control the LCD to display the video signal. Still further, the LCD driving circuit comprises a PWM and shutdown circuit for supplying power to the LCD and shutting down the LCD when the LCD has been idle for a preset period. Most of the constituent circuit components of the LCD driving circuit can be implemented in a single LSI integrated circuit. The LCD driving circuit is therefore compact in size, low in manufacturing cost, and low in power consumption.

Digital liquid crystal display driving circuit

A drive circuit of a thin-film transistor type liquid crystal display. A plurality of source drivers is connected in series. Each of the source drives has a charge pump therein to compensate the voltage drop caused by the metal wires for connecting the neighboring source drivers. The charge pump is preferably disposed at an input of the power line. A capacitor is further connected to each of the power lines for rectifying and filtering the power source transmitted by the power lines. The drive circuit also has a plurality of gate drivers. When the voltage drop caused by the power transmission line between the gate drivers is significant enough to affect a normal operation of the gate drivers, the charge pump is installed in each of the gate drivers.

Drive circuit of TFTLCD

A digital liquid crystal display (LCD) driving circuit is provided for driving an LCD to display video images. The LCD driving circuit comprises a digital gamma-correction and inversion circuit for performing a digital gamma-correction process on the digitized video signal and then performing a polarity inversion process on selected lines of the video signal. The digital gamma-correction and inversion circuit is coupled directly to a display memory unit so as to fetch the digitized video signal directly from the display memory unit. A digital-to-analog conversion means is coupled to the digital gamma-correction and inversion circuit for converting the digital output of the digital gamma-correction and inversion circuit into analog form. Further, the LCD driving circuit comprises an LCD timing control circuit, which is coupled to receive a plurality of video control signals associated with the digitized video signal, for converting the video control signals into an LCD timing control signal to control the LCD to display the video signal. Still further, the LCD driving circuit comprises a PWM and shutdown circuit for supplying power to the LCD and shutting down the LCD when the LCD has been idle for a preset period. Most of the constituent circuit components of the LCD driving circuit can be implemented in a single LSI integrated circuit. The LCD driving circuit is therefore compact in size, low in manufacturing cost, and low in power consumption.

A method is provided for displaying an original high-resolution digital color image on a low-resolution color dot-matrix display such as a liquid crystal display (LCD). Generally speaking, the method is used to display an original digital color image of a resolution of A&times;B on a color display of a resolution of C&times;D, where A, B, C, D are positive integer numbers and A>C and B>D. The first step is to group the pixels of the original digital color image in a unit of E into a plurality of groups equal in number to the pixels in the color display, where E is a ratio value obtained by rounding up the result of the division of A by C to the nearest integer number. Each of the groups is matched to one pixel in the color display. From each group, a set of RGB values is respectively extracted from selected pixels in the group, in a featured RGB extraction method. The final step is then to drive each pixel in the color display to display a specific color corresponding to the assigned RGB values. This process is repeated until all the groups in the same horizontal line and all the horizontal lines in the original digital color image are matched to the pixels in the LCD. This method allows the resulting image on the low-resolution LCD to have high fidelity to the original high-resolution image.

Growing community of inventors

Hsinchu Hsien, Taiwan

Tsung-Pei Chiang