3m Innovative Properties Company

U.S. Precision Lens Incorporated

Richard J Wessling

Jacob Moskovich

Michael B Larson

Projection lens systems for use with cathode ray tube (CRT) projection televisions are provided which have positive first lens units (U) and negative second lens units (U) where the negative second lens units are customized in terms of at least one optical property for at least two of the colors of light produced by the CRTs with which the units are used. The at least one optical property is not spectral transmission, although the second lens units can also be customized for spectral transmission. As illustrated in FIGS.B&#x2013;F and FIGS.B&#x2013;F, such customization of a non-transmissive property provides an effective and cost effective approach for improving the color performance of CRT projection lens systems. Constructions for the positive first lens unit which improve image contrast and reduce manufacturing costs are also provided.

Lens systems for projection televisions

Projection lens systems for use with cathode ray tube (CRT) projection televisions are provided which have positive first lens units (U ) and negative second lens units (U ) where the negative second lens units are customized in terms of at least one optical property for at least two of the colors of light produced by the CRTs with which the units are used. The at least one optical property is not spectral transmission, although the second lens units can also be customized for spectral transmission. As illustrated in FIGS. B- F and FIGS. B- F, such customization of a non-transmissive property provides an effective and cost effective approach for improving the color performance of CRT projection lens systems. Constructions for the positive first lens unit which improve image contrast and reduce manufacturing costs are also provided.

Disclosed is an improved color projection TV lens system which provides reduced chromatic aberration and improved chromaticity. These improvements are achieved by incorporating a light absorbing material into at least one lens in the system wherein the lens has a substantially uniform thickness.

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Milford, OH, United States of America

Richard J Wessling