Partial color-corrected projection lens system
First Claim
Patent Images
1. A projection lens system for use with a cathode ray tube, said system having an image side and comprising in order from said image side:
- a) a corrector lens unit of weak optical power, said unit comprising in order from said image side;
i) a first lens element which has a negative power on axis and comprises at least one aspherical surface, said first lens element being composed of a high dispersion material; and
ii) a second lens element which has a positive power and is composed of a low dispersion material;
b) a power lens unit providing most of the positive optical power of the lens system;
c) a lens unit of weak optical power comprising at least one aspherical surface; and
d) a lens unit which has a strong negative power, is associated with the cathode ray tube during use of the lens system, and provides most of the correction to the field curvature of the lens system.
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Abstract
Projection lens systems (13) for use in projection televisions are provided. The systems are characterized by a screen side lens unit (U1) which: (1) has a weak optical power; (2) has a negative, aspherical lens element composed of a high dispersion material; and (3) has a positive lens element which is composed of a low dispersion material.
82 Citations
9 Claims
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1. A projection lens system for use with a cathode ray tube, said system having an image side and comprising in order from said image side:
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a) a corrector lens unit of weak optical power, said unit comprising in order from said image side;
i) a first lens element which has a negative power on axis and comprises at least one aspherical surface, said first lens element being composed of a high dispersion material; and
ii) a second lens element which has a positive power and is composed of a low dispersion material;
b) a power lens unit providing most of the positive optical power of the lens system;
c) a lens unit of weak optical power comprising at least one aspherical surface; and
d) a lens unit which has a strong negative power, is associated with the cathode ray tube during use of the lens system, and provides most of the correction to the field curvature of the lens system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification