Brillian Corporation

Three-Five Systems, Inc.

John Karl Waterman

Russell J Flack

Matthias Pfeiffer

Terence R Klein

John D Titus

Andreas Grubert

Terry Klein

Terrence R Klein

Jason Wellman

Methods and apparatus are provided for driving a liquid crystal microdisplay. The apparatus comprises more than one display driver integrated circuit where a liquid crystal microdisplay receives video information from at least two separate and distinct display driver integrated circuits. One of the display driver integrated circuits is designated as producing a master clock. The internal clocks of the other display driver integrated circuits are compared to the master clock and adjusted to reduce the phase difference to a delay that does not produce visible artifacts on the microdisplay. The frame polarity is compared to be the same from each integrated circuit driving the microdisplay before outputting video information. A frame synchronization signal is also generated from each display driver integrated circuit to ensure that they are all ready to provide information to the microdisplay.

Display driver architecture for a liquid crystal display and method therefore

A liquid crystal display (LCD) system, comprising a matrix of pixels, analyzes a video data stream for grayscale level jumps from extreme black to moderate gray levels. Transitions in grayscale levels are restricted between adjacent pixels so as to reduce image degradation due to fringe field effects. A memory, such as a plurality of shift registers, may be used to store grayscale levels of adjacent pixels which are compared and if a ratio between these grayscale levels exceeds a desire value then at least one of the grayscale levels is modified.

Image quality improvement for liquid crystal displays

A liquid crystal display (LCD) system, comprising a matrix of pixels, analyzes a video data stream for grayscale level jumps from extreme black to moderate gray levels. Transitions in grayscale levels are restricted between adjacent pixels so as to reduce image degradation due to fringe field effects. A memory, such as a shift register, may be used to store and then grayscale levels to be written to adjacent pixels are compared and if a difference between these grayscale levels exceed a certain value then at least one of the grayscale levels is modified.

A liquid crystal display (LCD) having a matrix of liquid crystal pixels is provided. A plurality of digital-to-analog converters (DACs) are coupled to the LCD matrix through analog voltage switches and are adapted to produce output voltages that are applied to the pixels in the LCD matrix. Through the combination of DACs and analog voltage switches, groups of pixels are pre-written to an average value of the pixels in that group which is fairly close to their final voltage values of each pixel so that the liquid crystal material can begin slewing and settling as early as possible. Then one or more writes to each of the pixels is made of the precise voltage value desired at each of the pixels. Alternate, adjacent odd and even rows of pixels may be written together and then only the even or odd rows are finally written to obtain the desired final voltage values at each of the pixels in the LCD.

Frame prewriting in a liquid crystal display

A matrix of liquid crystal pixels ( ) is provided. A digital-to-analog converter (DAC) ( ) is coupled to the matrix and produces an output voltage that can be applied to one or more pixels in the matrix. The DAC ( ) receives a multi-bit digital input and generates its output voltage to correspond to the digital input. The conversion function of the DAC is adapted to have a higher resolution within a voltage range in which most grayshade changes of the LCD occur.

System and method for providing voltages for a liquid crystal display

A system for handling an input video stream comprises an internal clock generator generating a first clock and a synchronization unit receiving the input video stream having an associated second clock being slower than the first clock. The synchronization unit samples the second clock with the first clock thereby generating a third clock synchronized with the first clock having no signal in case of a data gap. This signal can be used to determine the dwelling time for a charge being applied to a pixel which will be constant even without a buffer memory.

System and method for handling the input video stream for a display

Image quality improvement for liquid crystal display

A matrix of liquid crystal pixels ( ) is provided. A digital-to-analog converter (DAC) ( , and ) is coupled to the matrix and produces an output voltage that can be applied to one or more pixels in the matrix. The DAC ( , and ) receives a calibrated multi-bit digital input and generates its output voltage to correspond to the digital input. A reference voltage generator ( ) generates at least two reference voltages at an output that is coupled to one input of a comparator ( ). Another input of the comparator ( ) is coupled to the DAC ( , and ) output. When the comparator ( ) is activated, it outputs one of two signals: a first signal when one input receives a higher voltage; and a second signal when the other input receives a higher voltage. A digital calibrator ( ) has at least one output and at least one input. The digital calibrator ( ) is adapted to receive an uncalibrated multi-bit digital signal at the input. The digital calibrator ( ) is also adapted to modify the uncalibrated multi-bit digital signal based at least in part on the output of the comparator ( ) to produce the calibrated digital signal. The digital calibrator ( ) applies the calibrated multi-bit digital signal at the output. The output of the digital calibrator ( ) is coupled to the input of the DAC ( , and ).

System and method for actuating a liquid crystal display

A liquid crystal display (LCD) system, comprising a matrix of pixels, actuates each pixel by applying positive and negative voltage differences across a liquid crystal layer. The liquid crystal layer is parallel to a transparent cover. The transparent cover is adjacent to a cover electrode. Each pixel includes a pixel electrode positioned on the opposite side of the liquid crystal layer from the cover electrode. The positive and negative voltage differences are asymmetric to compensate for polarity-dependent characteristics of the LCD materials. The positive and negative voltage differences are applied for durations that counterbalance the asymmetric rates of charge accumulation.

Asymmetric liquid crystal actuation system and method

The present invention comprises a flat panel display, such as a liquid crystal microdisplay having a plurality of square and rectangular pixel electrodes that are addressable separately to produce a fine resolution display or addressable in combination to create a lower resolution display. By providing an array of square pixel electrodes with adjacent rectangular electrodes, the display is capable of displaying, for example, XGA or SXGA video data, full-size undistorted and in its native display format, thus obviating the need for expensive image processing chips to convert the image data from one format to another.

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Mesa, AZ, United States of America

John Karl Waterman