Ncr Corporation

Kazem Memarzadeh

John Fredrick Crooks

Robert L Protheroe

Driving apparatus for a liquid crystal display. The apparatus includes a square wave generator which drives an operational amplifier. The operational amplifier has a pair of parallel feedback paths, one of which is a capacitive feedback path and the other of which is a resistive feedback path. Automatic temperature compensation is provided by incorporating a thermistor in the resistive feedback path. The output signal from the operational amplifier varies in a linear manner with temperature so as to produce an optimal drive for the liquid crystal display.

Temperature compensation apparatus for liquid crystal display

A method for mapping sampled patterns into a lower resolution display device whereby a continuous image of the sampled pattern is reproduced. The method comprises determining the pixel location of each element of high resolution sampled data and the relative location within the pixel, deciding whether the pixels corresponding to the mapped data points should be included in the image, and graphically connecting selected pixels which are separated by one or more pixels. The process of pixel selection is aided by dividing each pixel into two separate areas, the boundary of which is determined by a predetermined geometric shape such as a diamond or circle which is entirely contained within a pixel. If a high resolution sampled data point or a connecting line falls within that predetermined geometric shape inside the pixel, then that pixel is selected, whereas data points falling outside the predetermined area within the pixel do not select that pixel for activation.

Method for converting high resolution data into lower resolution data

A technique for mapping high resolution data into a lower resolution frame, in applications in which the original high resolution data contains a small amount of noise. The improvement is achieved by the introduction of a hysteresis loop into the mapping process.

Process for mapping high resolution data into a lower resolution

A self-tuning digitizer control circuit and method which employs a tunable excitation source instead of a tunable front end. In addition, the digitizer control circuit includes a stylus for sensing the excitation signal, and a circuit for processing the information signal from the stylus, including a narrow bandpass filter for passing the frequency of the excitation signal and minimizing the passage of extraneous noise. A controller determines the location of the stylus on the active surface of the digitizer and control operation of the circuit. The excitation source includes, in the preferred embodiment, a tunable divide-by-n circuit employing an 8-bit latch, an 8-bit counter, and a state machine. A nonvolatile memory stores the most recent value for the divisor value n. Provision is also made for a tuning method for the divide-by-n circuit.

Self-tuning digitizer control circuit and method

A digitizer screen and method of making. A coated conductive plastic film is perforated and is used in conjunction with a glass or other panel to provide a screen which may be used in an electronic digitizer for converting the position and movement of a stylus or other device on the screen to electrical signals representative of such positioning and movement. The perforated coated conductive plastic film may be laminated to the glass panel to form an integrated structure which does not require the use of masking and etching or similar processes to produce a desired apertured matrix pattern in the plastic film. Various arrangements of the plastic film are disclosed which facilitate the connection of the apertured portion of the plastic film to associated electronic components.

Growing community of inventors

Cambridge, OH, United States of America

Kazem Memarzadeh