Abstract: Partial memory control for a video display driver in which data storage is provided for storing and providing a plurality of video pixel data having selectable ones of a plurality of pixel color depths to be displayed by a plurality of video displays having a plurality of mutually distinct dimensions.

Abstract: A display system provides temporal stochastic dithering to image data for storage in a frame buffer for display. Stochastic dithering is used to reduce the size of the frame buffer and the complexity of the drive circuitry that is used to display an image in accordance with the image data. The bit depth of the frame buffer is reduced by spatially dithering image data for the image data before the image data is written into the frame buffer. Additionally, the displayed image is temporally dithered by using a different dither pattern for successive frames. Uncorrelated stochastic dither patterns are used to minimize detection of the dither patterns within the displayed image.

Abstract: A method is arranged to process a frame for an LCD with a modified polarity pattern. The pattern employs a polarity reversal scheme that results in line inversion and/or dot inversion patterns that are observable by pixel locations within the frame. The drive polarity for the column drivers in the LCD is toggled according to the modified polarity pattern. The scanning sequence for each row on the display is modified for cooperation with the pattern. A first subframe is scanned during a first interval while applying a first set of drive polarities. A second subframe is scanned during a second interval that is non-overlapping with the first time interval. The application of the method enables the column drivers in the LCD to operate with reduced power while retaining the benefits of line and dot inversion techniques.

Abstract: A method is arranged to process a frame for an LCD with a modified polarity pattern. The pattern employs a polarity reversal scheme that results in line inversion and/or dot inversion patterns that are observable by pixel locations within the frame. The drive polarity for the column drivers in the LCD is toggled according to the modified polarity pattern. The scanning sequence for each row on the display is modified for cooperation with the pattern. A first subframe is scanned during a first interval while applying a first set of drive polarities. A second subframe is scanned during a second interval that is non-overlapping with the first time interval. The application of the method enables the column drivers in the LCD to operate with reduced power while retaining the benefits of line and dot inversion techniques.

Abstract: A display system provides stochastic dithering to image data for storage in a frame buffer for display. Dithering is used to reduce the size of the frame buffer and to reduce the complexity of the drive circuitry that is used to display an image. The bit depth of the frame buffer is reduced by spatially dithering image data before it is written into the frame buffer. Stochastic dither patterns (which are uncorrelated) are used to minimize adverse effects of the dither patterns within the displayed image.

Abstract: A column driver for a graphics display has reduced power consumption by sharing power between upper and lower column amplifiers. The upper column amplifier operates over an upper supply range, while the lower column amplifier operates over a lower supply range. The upper and lower amplifiers have the substantially the same quiescent operating current such that the total operating current for the column drivers in the graphics display is reduced by a factor of two. Each column amplifier can be driven over half of the power-supply range such that lower voltage amplifiers may be employed for the column driver amplifiers.

Abstract: The present invention provides a point-to-point data bus architecture and a protocol for a graphics system. The TCON transmits the data to the column drivers using separate point-to-point data buses. Data may be transmitted to the column drivers during a horizontal blanking period resulting in more data being written to the column drivers as compared to a typical graphical display system. As each point-to-point data bus contains only the data for its corresponding column driver the instantaneous data rate to any column driver is lower than in conventional multi-drop architectures. The point-to-point system has fewer printed circuit board (PCB) lines and a lower loop area than a conventional multi-drop system. A protocol may also be implemented. The protocol may provide for system level control and coordination of column drivers and other display system components. This protocol allows the TCON to control the operation of the column drivers without the need for extra PCB lines.

Abstract: An improved memory for graphics displays includes an improved memory cell. Data may be written and read from the single bit cell simultaneously, eliminating the need for additional memory circuits to service an N column driver for a display. Additionally, the architecture of the memory allows for a signal input port for writing the data to the cell while allowing for multiple parallel output ports for reading the data. The unique architecture eliminates the need for addressing logic and refresh circuitry for display applications.

Abstract: A data/clock deskewing methodology uses a delay-locked loop (DLL) circuit. The DLL circuit generates a number of clock phases in response to an input clock, where each clock phase is delayed relative to the input clock signal. The clock phases are used to sample data from a data line. The sampled data is checked against a preamble pattern (a sequence of known data). A digital deskew control block selects one of the clock phases after analyzing the results of preamble pattern check such that subsequently received data is sampled with the appropriately selected clock phase.

Abstract: A method is arranged to process a frame for an LCD with a modified polarity pattern. The pattern employs a polarity reversal scheme that results in line inversion and/or dot inversion patterns that are observable by pixel locations within the frame. The drive polarity for the column drivers in the LCD is toggled according to the modified polarity pattern. The scanning sequence for each row on the display is modified for cooperation with the pattern. A first subframe is scanned during a first interval while applying a first set of drive polarities. A second subframe is scanned during a second interval that is non-overlapping with the first time interval. The application of the method enables the column drivers in the LCD to operate with reduced power while retaining the benefits of line and dot inversion techniques.

Abstract: The present invention relates to a signal driver circuit for driving a liquid crystal display panel. The signal driver circuit provides level shifting within the circuit to lower the power consumption of a liquid crystal display module while still providing a wide analog voltage range to the liquid crystal display elements. The decoding circuits utilize a strand of abutting decode input transistors which are connected in series. Further to reduce the physical size of the decoding circuits, multiple decode circuits may share circuitry that decodes the most significant bits of a data word. A cell layout is utilized such that the most significant bits data are bused into the cell through metal lines and the least significant bits are bused in polysilicon that also operates as the gate of the decode input transistors. Moreover, the decode cell input transistors may all be of the same conductivity type.

Abstract: The present invention relates to a signal driver circuit for driving a liquid crystal display panel. The signal driver circuit provides level shifting within the circuit to lower the power consumption of a liquid crystal display module while still providing a wide analog voltage range to the liquid crystal display elements. The decoding circuits utilize a strand of abutting decode input transistors which are connected in series. Further to reduce the physical size of the decoding circuits, multiple decode circuits may share circuitry that decodes the most significant bits of a data word. A cell layout is utilized such that the most significant bits data are bused into the cell through metal lines and the least significant bits are bused in polysilicon that also operates as the gate of the decode input transistors. Moreover, the decode cell input transistors may all be of the same conductivity type.

Abstract: The present invention relates to a signal driver circuit for driving a liquid crystal display panel. The signal driver circuit provides level shifting within the circuit to lower the power consumption of a liquid crystal display module while still providing a wide analog voltage range to the liquid crystal display elements. The decoding circuits utilize a strand of abutting decode input transistors which are connected in series. Further to reduce the physical size of the decoding circuits, multiple decode circuits may share circuitry that decodes the most significant bits of a data word. A cell layout is utilized such that the most significant bits data are bused into the cell through metal lines and the least significant bits are bused in polysilicon that also operates as the gate of the decode input transistors. Moreover, the decode cell input transistors may all be of the same conductivity type.

Abstract: The present invention relates to a signal driver circuit for driving a liquid crystal display panel. The signal driver circuit provides level shifting within the circuit to lower the power consumption of a liquid crystal display module while still providing a wide analog voltage range to the liquid crystal display elements. Furthermore, reference voltages are provided to decoding circuits by using distributed resistors. The decoding circuits utilize a cell layout that allows data to bused into the cell through polysilicon that also operates as the gate of the decode input transistors. The decode input transistors are arranged in strands of abutting transistors which may be connected in series or in parallel. Moreover, the decode cell input transistors may all be of the same conductivity type.

Abstract: A camera power supply system includes a controller that reduces power consumption by modifying the operation of the camera system clock circuit after the completion of each exposure taking sequence. The clock circuit operation is modified either by bypassing current drains, thereby reducing the accuracy of the clock circuit as well as its power consumption, or by reducing the frequency of the clock pulses produced by the system clock. Modifying the operation of the system clock in this way does not adversely affect operation of systems such as information displays, but does reduce power consumption. The clock circuit operation is restored at the beginning of an exposure sequence.

Abstract: A low cost, reflectivity insensitive rangefinder for performing time-multiplexed multi-zone auto-ranging comprises a light projecting means energizable for projecting a beam of light to illuminate a spot on an object in a scene. A linear array of N photosensitive elements views the scene and produces N photosignals representing the brightness of the scene, wherein each photosensitive element corresponds to one of N discrete subject distance zones, in sequence, from a far zone to a near zone. A control signal generating means generates process control signals for initiating intermediate zone ranging operations. A selection signal supply means supplies selection signals for effectuating a time-multiplexed multi-zone ranging operation. An analog multiplexer means, responsive to the selection signals, inputs the N photosignals, in parallel, and outputs selected time-multiplexed pairs of photosignals.

Abstract: A DC-to-DC converter is operated in accordance with a predetermined primary circuit ON time and a sensed predetermined secondary circuit current level to provide improved charging performance and extended battery life. Energy is stored in the primary of a coupled inductor when power in the primary, provided by a battery having an internal impedance which varies over the battery's lifetime, is switched ON for a predetermined time t.sub.ON. Upon expiration of time t.sub.ON, power is switched OFF, whereupon stored energy is transferred to the secondary via a flyback type process, thus charging a storage capacitor. A preventing means prevents a premature switching ON of power in the primary subsequent to the expiration of time t.sub.ON. The energy storage cycle repeats when current sensed in the secondary decreases below a predetermined minimum current threshold.

Abstract: A continuous-tone thermal printer includes a transport mechanism for advancing a print medium past a thermal print head while continuous-tone image information is being printed, line-by-line, on the medium. To increase the rate at which thermal prints are produced, the printer includes asynchronous motor-control apparatus for selectively accelerating the movement of the print medium relative to the print head to quickly locate the print head at the start of a new image line immediately following the printing of that pixel(s) having the highest image density in the preceding image line. Preferably, such motor-control apparatus includes a digital signal processor which determines the maximum pixel density on each line. Upon printing such maximum pixel density, the digital signal processor causes a motor controller to temporarily increase the print medium velocity past the thermal print head to the start of the next image line.

Abstract: A method of scanning intrusion detection which is capable of monitoring a large volume of either interior or exterior space from a single relatively inexpensive unit. This method of intrusion detection comprises the steps of scanning a beam of infrared radiation about a field of view and receiving the radiation of the beam reflected from the field of view, generating a signal indicative of the distance from the device at which the beam has been reflected for each of a plurality of azimuthal sectors of the field of view, storing a plurality of reference signals which are indicative of the distance of reflection of the beam from each azimuthal sector of the field of view during a reference time period, comparing the signals from a selected time period with the reference signals, and generating an output signal if one of the signals is different from the respective reference signal.

Abstract: A scanning intrusion detection device is capable of monitoring a large volume of either interior or exterior space from a single relatively inexpensive unit. This intrusion detection device comprises a radiation emitter arranged to scan a beam of infrared radiation about a field of view and means for receiving the radiation of the beam reflected from the field of view. The receiver is arranged to generate a signal indicative of the distance from the device at which the beam has been reflected for each of a plurality of azimuthal sectors of the field of view during a selected time period. A ram is also provided for storing a plurality of reference signals which are indicative of the distance of reflection of the beam from each azimuthal sector of the field of view during a reference time period. The signals from a selected time period are compared with the reference signals and an output signal is generated if one of the signals is different from the respective reference signal.