3m Innovative Properties Company

Tektronix, Inc.

Frederic R Engstrom

Arlie R Conner

Bruce L Cannon

Peter Richard Oehler

Gary B Kingsley

Described is an optical lens having a light-receiving surface facing a light source and a first structured surface opposite a first portion of the light-receiving surface. The first structured surface includes a plurality of first reflecting surfaces and first refractive surfaces. Each of the first refractive surfaces receives light from a corresponding first reflective surface for refractive transmission therethrough. The optical system may further include a second structured surface opposite a second portion of the light-receiving surface. The second structured surface includes a plurality of second refractive surfaces. Each of the second refractive surfaces receives light directly from the light-receiving surface. Where the first and second structured surfaces are included, the first and second portions of the light-receiving surface can be positioned so that light projected from the light source at an angle above a threshold angle falls on the first portion and light at an angle below the threshold angle falls on the second portion.

Total internal reflection Fresnel lens and optical system using the same

Methods for illuminating the display area of a liquid crystal panel () are provided. Illumination light () is compressed into a stripe which is scanned across the display area in synchronization with the display's refresh cycle. In particular, the scanning is performed so that for each row of the display, the majority of the illumination light which impinges on the row as a result of the scan is in the last half of the cycle fresh period for the row. In this way, the ability to display moving objects is improved.

Swept illumination to reduce LCD lag in front and rear projection displays

The present invention is particularly useful for projection systems in which portions of an unwanted light beam overlap with the image beam. Such an overlap reduces the image contrast. Under the present invention, an aperture is used to restrict the extent of the unwanted beam while an integrator changes the shape of the light beam illuminating the image display device. The integrator changes the illumination beam so as concentrate the light in those areas of the illumination beam that are transmitted through the aperture. When the aperture and the integrator are used together in the projection system, both the image brightness and the image contrast are increased.

Contrast and brightness enhancing apertures for illumination displays

An improved method of screening a color cathode ray tube of the shadow mask type is disclosed. The shadow mask is used to form a corresponding virtual mask on the outer or viewing surface of the CRT faceplate. The virtual mask then is employed as a substitute for the shadow mask in the subsequent photoprinting of a color display screen on the faceplates's inner surface. Advantages include reduced handling of the fragile shadow mask, which reduces the costs associated with replacing such masks if they become damaged, and better defined and registered phosphor deposits.

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Hillsboro, OR, United States of America

Frederic R Engstrom