U.S. Philips Corporation

North American Philips Corporation

Arne L Duwaer

Johannes H Spruit

Leendert Vriens

Willem M Van Alphen

Aart A Van Gorkum

Jill F Goldenberg

Bernardus J Brugman

Alexander R Van Schoonhoven

A light valve projection system includes an illumination system having a light collector in the form of a non-imaging reflector with a rectangular input aperture and a rectangular output aperture. A two dimensional light source at the input aperture illuminates the output aperture substantially uniformly.

Light valve projection system with improved illumination

A monochrome cathode ray tube including a magnetic focusing device provided with means for generating a static magnetic focusing field. These means surround the neck of the cathode ray tube without contacting this neck, and a system of correction coils for generating an additional focusing field and 2-, 4- and/or 6-pole fields is provided coaxially between these means and the neck of the tube.

Cathode ray tube including a magnetic focusing lens

In a matrix display device, such as an LCD-TV, supply of data signals to each one of an array of display elements is controlled by respective switching means in response to applied switching signals. Novel addressing circuitry is provided to achieve redundancy and avoid improper charge levels on non-selected switching means.

Thin film active matrix and addressing circuitry therefor

A projection television convergence method and apparatus allow rapid and simple correction of low-order misconvergence and misgeometry problems. A hybrid system employs digital programmable attenuators and a digital control system, making it possible to eliminate misconvergence and misgeometry using simple local adjustment on a limited number (e.g., 9) of locations in the picture. The values of the coefficients in the correction waveforms, which are represented by the settings on a number of programmable attenuators, are determined by simultaneously solving the convergence governing equations, and are stored in memory. Thus, the prior art tedious individual adjustment of typically more than 30 potentiometers, each with global effects, by a factory worker, service-engineer or the consumer is obviated. An alternate embodiment includes a simple black and white camera to eliminate the human adjuster. The system detects areas of misconvergence or misgeometry in the composite image by measuring the luminace reflected from the screen during the projection of complementary test patterns of equal luminance in the separate image sources. The system treats areas of luminace discrepancy as misconverged areas, and causes an appropriate level of correction signals to be fed to the misconverged CRTs.

Color projection television system with apparatus for correcting

A projection color television system having an improved resolution and luminance comprises red, green and blue color emitting tubes, the electron beams of which are focused onto their respective screens. In order to compensate for the strong saturation of the blue phosphor, and simultaneously to take advantage of the relatively fast decay of this phosphor, the blue color emitting tube is a single gun, multispot display tube. The increase in light output obtainable from the blue color emitting tube is matched by providing interference filters in the red and green color emitting display tubes and optionally in all three red, green and blue emitting tubes.

Three tube color projection television system having multispot blue tube

The invention relates to a display tube which is cooled by a flow of a translucent cooling liquid through a sealed space adjacent the display window, stimulated by a fluid-driven pump having two chambers, a drive chamber driven by a remotely located active electric motor driven pump, and a pump chamber responsive to the drive chamber and connected to the sealed space. Fields generated by the motor of the electric pump do not interfere with the operation of the display tube.

Growing community of inventors

Ossining, NY, United States of America

Arne L Duwaer