US4810075A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection system with a cathode ray tube and a lens
Assignee: Hitachi Ltd
•
Filing: 1985-03-25
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Granted: 1989-03-07
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Expires: 2005-03-25
Abstract
Abstract A projection system comprising from the image end a screen, a lens in which a core portion including the lens axis accomplishes a convergence function and in which a peripheral portion including a lens edge thereof accomplishes the divergence function, a convex lens element, a concave lens element and a CRT having a face glass whose inner surface is coated with a phosphor and is so curved to form a fourth lens element with a curvature center within a core portion including the lens axis is disposed on the screen side of the projection system, the curvature radius of each part of the core portion of the fourth lens increasing thereof in accordance with increments of the semi-aperture distance of each part from the lens axis.
Inventors
- 👤 Kyohei Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:13
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/34; G02B13/00; G02B13/16; G02B13/18; G02B9/12
Claims Analysis
Total Claims: 53
Claim 1
Independent Claim
156 words
A system for projecting an optical image along an optical axis on a screen, comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a convex lens surface; (c) a third lens means containing the optical axis and having a concave lens surface; and (d) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fourth lens means having a curvature center within a core portion including the lens axis of the fourth lens means that is disposed on the screen side of the projection system, a radius of curvature of part of the core portion of the fourth lens means being non constant for reducing field curvature.
Claim 2
Independent Claim
156 words
A system for projecting an optical image along an optical axis on a screen, comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a convex lens surface; (c) a third lens means containing the optical axis and having a concave lens surface; and (d) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fourth lens means having a curvature center within a core portion including the lens axis of the fourth lens means that is disposed on the screen side of the projection system, a radius of curvature of part of the core portion of the fourth lens means being non constant for reducing field curvature.
Claim 3
Dependent Claim
22 words
A system in accordance with claim 1, further comprising a diaphragm disposed between the first lens means and the second lens means.
Claim 4
Dependent Claim
20 words
A system in accordance with claim 2, wherein the first, second and third lens means are made from plastic material.
Claim 5
Dependent Claim
34 words
A system in accordance with claim 1, wherein the curvature radius of part of the fourth lens means increases in accordance with increments of the semi-aperture distance of each part from the lens axis.
Claim 6
Independent Claim
184 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a positive meniscus lens element with a convex surface toward the screen surface; (c) a third lens means containing the optical axis and having a lens element with convex surfaces; (d) a fourth lens means containing the optical axis and having a lens element with a concave surface; and (e) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fifth lens means having a curvature center within a core portion including the lens axis of the fourth lens means that is disposed on the screen side of the projection system, the curvature radius of part of the core portion of the fifth lens means being non constant for reducing field curvature.
Claim 7
Independent Claim
184 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a positive meniscus lens element with a convex surface toward the screen surface; (c) a third lens means containing the optical axis and having a lens element with convex surfaces; (d) a fourth lens means containing the optical axis and having a lens element with a concave surface; and (e) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fifth lens means having a curvature center within a core portion including the lens axis of the fourth lens means that is disposed on the screen side of the projection system, the curvature radius of part of the core portion of the fifth lens means being non constant for reducing field curvature.
Claim 8
Dependent Claim
22 words
A system in accordance with claim 5, further comprising a diaphragm disposed between the first lens means and the second lens means.
Claim 9
Dependent Claim
30 words
A system in accordance with claim 6, wherein the first, second and third lens means are made from plastic material and the fourth lens means is made from glass material.
Claim 10
Dependent Claim
34 words
A system in accordance with claim 5, wherein the curvature radius of part of the fifth lens means increases in accordance with increments of the semi-aperture distance of each part from the lens axis.
Claim 11
Independent Claim
167 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a convex lens surface; (c) a third lens means containing the optical axis and having a concave lens surface; and (d) a CRT having a face glass with an inner surface coated with a phosphor and being curved to form a fourth lens means with a core portion having a curvature center facing the screen, the curved surface being defined from the optical axis by a series of circles of changing radius with the curvature radius of points along each circle being the same and the curvature radius of points on each different circle being a function of the radius of each circle for reducing field curvature.
Claim 12
Independent Claim
167 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a convex lens surface; (c) a third lens means containing the optical axis and having a concave lens surface; and (d) a CRT having a face glass with an inner surface coated with a phosphor and being curved to form a fourth lens means with a core portion having a curvature center facing the screen, the curved surface being defined from the optical axis by a series of circles of changing radius with the curvature radius of points along each circle being the same and the curvature radius of points on each different circle being a function of the radius of each circle for reducing field curvature.
Claim 13
Dependent Claim
13 words
A system in accordance with claim 9, wherein the function increases with radius.
Claim 14
Dependent Claim
22 words
A system in accordance with claim 10, further comprising diaphragm means disposed between the first lens means and the second lens means.
Claim 15
Dependent Claim
21 words
A system in accordance with claim 11, wherein the first, second and third lens means are made from a plastic material.
Claim 16
Dependent Claim
19 words
A system in accordance with claim 9, wherein the curved surface has a series of circles of increasing radius.
Claim 17
Independent Claim
198 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a positive meniscus lens element with a convex surface toward the screen surface; (c) a third lens means containing the optical axis and having a lens element with convex surfaces; (d) a fourth lens means containing the optical axis and having a lens element with a concave surface; and (e) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fifth lens means with a core portion having a curvature facing the screen, the curved surface being defined from the optical axis by a series of circles of changing radius with the curvature radius of points on each different circle being the same and the curvature radius of points on each different circle being a function of the radius of each circle for reducing field curvature.
Claim 18
Independent Claim
198 words
A system for projecting an optical image along an optical axis on a screen comprising: (a) a first lens means having a lens core portion containing the optical axis which causes convergence of the image and a peripheral portion with a lens edge which causes divergence of the image; (b) a second lens means containing the optical axis and having a positive meniscus lens element with a convex surface toward the screen surface; (c) a third lens means containing the optical axis and having a lens element with convex surfaces; (d) a fourth lens means containing the optical axis and having a lens element with a concave surface; and (e) a CRT having a face glass with an inner surface which is coated with a phosphor and being curved to form a fifth lens means with a core portion having a curvature facing the screen, the curved surface being defined from the optical axis by a series of circles of changing radius with the curvature radius of points on each different circle being the same and the curvature radius of points on each different circle being a function of the radius of each circle for reducing field curvature.
Claim 19
Dependent Claim
13 words
A system in accordance with claim 14, wherein the function increases with radius.
Claim 20
Dependent Claim
22 words
A system in accordance with claim 15, further comprising diaphragm means disposed between the first lens means and the second lens means.
Claim 21
Dependent Claim
30 words
A system in accordance with claim 16, wherein the first, second and third lens means are made from plastic material and the fourth lens means is made from glass material.
Claim 22
Dependent Claim
19 words
A system in accordance with claim 14, wherein the curved surface has a series of circles of increasing radius.
Claim 23
Dependent Claim
58 words
A projection television system comprising: a cathode ray tube having a neck portion and a face glass with an internal surface on which phosphor elements are mounted, said internal surface being aspheric and convex to said neck portion to reduce field curvature; and optical means for projecting an image produced on said face glass onto a projection screen.
Claim 24
Dependent Claim
58 words
A projection television system comprising: a cathode ray tube having a neck portion and a face glass with an internal surface on which phosphor elements are mounted, said internal surface being aspheric and convex to said neck portion to reduce field curvature; and optical means for projecting an image produced on said face glass onto a projection screen.
Claim 25
Dependent Claim
74 words
The system of claim 19 wherein said optical means for projecting an image comprises from said projection screen side: a first aspheric lens providing a first power of magnification; a second biconvex lens for providing a power of magnification which is a major portion of enlargement provided by said optical means for projecting an image; and a third aspheric lens with a concave face on its screen side providing a negative power of magnification.
Claim 26
Dependent Claim
37 words
The system of claim 20 wherein: 0.9 r1<r2<1.1 r1 with r1 and r2 being curvature radii of core portions of the screen side surface of said first and second lenses, respectively, with said core portions being spherical.
Claim 27
Dependent Claim
32 words
The system of claim 20 wherein: 0.2fS<T12<0.4fS with T12 being the distance between said first and second lenses, and fS being a focal length of said optical means for projecting an image.
Claim 28
Dependent Claim
34 words
The system of claim 20 wherein: 0.25fS<t2<0.35fS with t2 being the thickness of said second lens along the optical axis, and fS being a focal length of said optical means for projecting an image.
Claim 29
Dependent Claim
83 words
The system of claim 19 wherein said optical means for projecting an image comprises from said projection screen side: a first aspheric lens providing a power of magnification; a second positive meniscus lens providing a positive power of magnification; a third biconvex lens providing a power of magnification which is a major portion of enlargement provided by said optical means for projecting an image; and a fourth aspheric lens with a concave face on its screen side providing a negative power of magnification.
Claim 30
Dependent Claim
88 words
The system of claim 19 wherein said optical means for projecting an image comprises from said projection screen side: a first plastic lens providing a power of magnification and having a pair of aspheric surfaces; a second glass lens providing a power of positive magnification and having a pair of spheric surfaces; a third plastic lens providing power of positive magnification and having a pair of aspheric surfaces; and a fourth plastic lens providing a negative power of magnification and having an aspheric surface on a screen side.
Claim 31
Dependent Claim
54 words
The system of claim 25 wherein: ##EQU3## with rm being the radius from an axis of said first lens, zm being a deviation in the axis of said first lens of an outermost effective portion of a screen side surface of said first lens, and RD is a curvature radius of said first lens.
Claim 32
Dependent Claim
49 words
The lens system of claim 25 wherein: 0<T2<0.04fS with T2 being the distance along a lens axis between a CRT side surface of said second lens and a screen side surface of said third lens, and fS is a focal length of said optical means for projecting an image.
Claim 33
Dependent Claim
33 words
The system of claim 19 wherein said internal surface of said face glass has a surface sag of approximately 5 mm at a peripheral point of said internal surface of said face glass.
Claim 34
Dependent Claim
33 words
The system of claim 20 wherein said internal surface of said face glass has a surface sag of approximately 5 mm at a peripheral point of said internal surface of said face glass.
Claim 35
Dependent Claim
33 words
The system of claim 25 wherein said internal surface of said face glass has a surface sag of approximately 5 mm at a peripheral point of said internal surface of said face glass.
Claim 36
Dependent Claim
134 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first aspheric lens providing a power of magnification; a second biconvex lens providing a power of magnification which is a major portion of enlargement provided by said optical means for projecting an image; and a third aspheric lens with a concave face on a screen side providing a negative power of magnification; wherein a surface of said face glass on which phosphor elements are mounted is convex to a neck portion of said cathode ray tube to reduce field curvature; and wherein 0.2fS<T12<0.4fS with T12 being a distance between said first and second lenses, and fS being the focal length of said optical system.
Claim 37
Dependent Claim
134 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first aspheric lens providing a power of magnification; a second biconvex lens providing a power of magnification which is a major portion of enlargement provided by said optical means for projecting an image; and a third aspheric lens with a concave face on a screen side providing a negative power of magnification; wherein a surface of said face glass on which phosphor elements are mounted is convex to a neck portion of said cathode ray tube to reduce field curvature; and wherein 0.2fS<T12<0.4fS with T12 being a distance between said first and second lenses, and fS being the focal length of said optical system.
Claim 38
Dependent Claim
166 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first lens of providing a power of magnification and having a pair of aspheric surfaces; a second lens providing a positive power of magnification and having a pair of spheric surfaces; a third lens having a pair of aspheric surfaces; and a fourth lens providing a negative power of magnification and having an aspheric surface at a screen side; wherein a surface of said face glass on which phosphor elements are mounted is convex to a neck portion of said cathode ray tube to reduce field curvature; and ##EQU4## with rm being a radius from an axis of said first lens, zm being a deviation in the axis of said first lens of the outermost effective portion of a screen side surface of said first lens, and RD is a curvature radius of said first lens.
Claim 39
Dependent Claim
166 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first lens of providing a power of magnification and having a pair of aspheric surfaces; a second lens providing a positive power of magnification and having a pair of spheric surfaces; a third lens having a pair of aspheric surfaces; and a fourth lens providing a negative power of magnification and having an aspheric surface at a screen side; wherein a surface of said face glass on which phosphor elements are mounted is convex to a neck portion of said cathode ray tube to reduce field curvature; and ##EQU4## with rm being a radius from an axis of said first lens, zm being a deviation in the axis of said first lens of the outermost effective portion of a screen side surface of said first lens, and RD is a curvature radius of said first lens.
Claim 40
Dependent Claim
197 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a CRT having a face glass on which an image to be projected to said screen is reproduced and upwardly facing a corner defined by said top and rear sides and said CRT is mounted in said cabinet; an optical unit mounted on said CRT over said face glass of said CRT for optically enlarging said image, upper and lower rays of light passing through an upper edge of the optical unit nearest said screen and nearest said rear side of said optical unit being transmitted respectively to upper and lower edges of said screen; and a mirror inserted between said screen and said optical unit for reflecting light transmitted through said optical unit from said CRT to said screen; and wherein said screen, said mirror and said optical unit are arranged so that said upper edge nearest said screen of said optical unit is located at a position adjacent a light path through which light reflected by a lower edge of said mirror passes.
Claim 41
Dependent Claim
197 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a CRT having a face glass on which an image to be projected to said screen is reproduced and upwardly facing a corner defined by said top and rear sides and said CRT is mounted in said cabinet; an optical unit mounted on said CRT over said face glass of said CRT for optically enlarging said image, upper and lower rays of light passing through an upper edge of the optical unit nearest said screen and nearest said rear side of said optical unit being transmitted respectively to upper and lower edges of said screen; and a mirror inserted between said screen and said optical unit for reflecting light transmitted through said optical unit from said CRT to said screen; and wherein said screen, said mirror and said optical unit are arranged so that said upper edge nearest said screen of said optical unit is located at a position adjacent a light path through which light reflected by a lower edge of said mirror passes.
Claim 42
Dependent Claim
48 words
An apparatus in accordance with claim 33, wherein: said upper edge nearest said screen of said optical unit is beneath said light path through which light reflected by a lower edge of said mirror passes and is above a horizontal line intersecting said lower edge of said screen.
Claim 43
Dependent Claim
26 words
An apparatus in accordance with claim 33, wherein: said optical unit includes coupling means connecting mechanically said optical unit to said face glass of said CRT.
Claim 44
Dependent Claim
35 words
An apparatus in accordance with claim 35, wherein: said optical unit further includes from said face glass side, a concave aspheric lens, a biconvex lens and a plastic lens having a pair of aspheric surfaces.
Claim 45
Dependent Claim
57 words
An apparatus in accordance with claim 36, wherein: 0.5ps<pa<1.5ps ##EQU5## with rm being a radius from an axis of said plastic lens, zm is the deviation in the axis of said plastic lens of an outermost effective portion of a mirror side surface of said plastic lens, and RD being a curvature radius of said plastic lens.
Claim 46
Dependent Claim
49 words
An apparatus in accordance with claim 35, wherein: said optical unit further includes from said face glass side, a lens with a concave surface, a plastic lens having a pair of aspheric surfaces, a lens having a convex surface and another plastic lens having a pair of aspheric surfaces.
Claim 47
Dependent Claim
36 words
An apparatus in accordance with claim 38, wherein: 0.2fs<T12<0.4fs with T12 being the distance between said another plastic lens and said lens having a convex surface, and fs being a focal length of said optical unit
Claim 48
Dependent Claim
134 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a mirror spaced from and inclined with respect to said screen, a lowest edge of said mirror being positioned higher than a lowest edge of said screen; a CRT having a face glass on which an image to be projected is reproduced and upwardly facing said mirror, and said CRT is mounted in said cabinet; and an optical unit mounted on said CRT over said face glass of said CRT to project said image onto said screen through a reflection at said mirror, and an upper part of said optical unit being positioned between said lowest edges of said mirror and screen.
Claim 49
Dependent Claim
134 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a mirror spaced from and inclined with respect to said screen, a lowest edge of said mirror being positioned higher than a lowest edge of said screen; a CRT having a face glass on which an image to be projected is reproduced and upwardly facing said mirror, and said CRT is mounted in said cabinet; and an optical unit mounted on said CRT over said face glass of said CRT to project said image onto said screen through a reflection at said mirror, and an upper part of said optical unit being positioned between said lowest edges of said mirror and screen.
Claim 50
Dependent Claim
128 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a mirror spaced and inclined to said screen, the lowest edge of said mirror being positioned higher than the lowest edge of said screen; a CRT having a face glass on which an image to be projected is reproduced and upwardly facing said mirror, and said CRT is mounted in said cabinet; and an optical unit mounted on said CRT over said face glass of said CRT to project said image onto said screen through a reflection at said mirror, an upper part of said optical unit being positioned above said lowest edge of said screen.
Claim 51
Dependent Claim
128 words
A projection display apparatus comprising: a cabinet having a top side, a bottom side, a front side and a rear side; a screen fitted in an upper part of said front side; a mirror spaced and inclined to said screen, the lowest edge of said mirror being positioned higher than the lowest edge of said screen; a CRT having a face glass on which an image to be projected is reproduced and upwardly facing said mirror, and said CRT is mounted in said cabinet; and an optical unit mounted on said CRT over said face glass of said CRT to project said image onto said screen through a reflection at said mirror, an upper part of said optical unit being positioned above said lowest edge of said screen.
Claim 52
Dependent Claim
106 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first aspheric lens providing a power of magnification; a second biconvex lens providing a power of magnification which is a major portion of enlargement provided by said optical system for projecting an image; and a third aspheric lens with a concave face on a screen side providing a negative power of magnification; and wherein 0.2fS<T12<0.4fs with T12 being a distance between said first and second lenses, and fs being the focal length of said optical system.
Claim 53
Dependent Claim
106 words
An optical system for enlarging an image produced on a face glass of a cathode ray tube and projecting the image onto a screen, comprising from a screen side: a first aspheric lens providing a power of magnification; a second biconvex lens providing a power of magnification which is a major portion of enlargement provided by said optical system for projecting an image; and a third aspheric lens with a concave face on a screen side providing a negative power of magnification; and wherein 0.2fS<T12<0.4fs with T12 being a distance between said first and second lenses, and fs being the focal length of said optical system.
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USPTO Annuity & Maintenance Windows
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| 3.5 Years (Year 4) | 1992-03-06 | 1992-09-05 | 1993-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-06 | 1996-09-05 | 1997-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-06 | 2000-09-05 | 2001-03-07 | $7700.00 | Window Closed / Lapsed |