US4963007A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color corrected projection lens
Assignee: UNITED STATES PRECISION LENS Inc
•
Filing: 1989-09-05
•
Granted: 1990-10-16
•
Expires: 2009-09-05
Abstract
Abstract A projection lens in which a lens unit which may comprise one or two elements is closely coupled at the object end of the lens to a cathode ray tube. At the image end is a lens unit of overall weak optical power which comprises from the image end a first positive element followed by a closely spaced negative element of substantially higher dispersion. Intermediate the object side lens unit and the image side lens unit is a lens unit of substantial optical power supplying substantially all of the positive optical power of the lens. Closely spaced to this power lens unit on the object side is a negative lens element of high dispersion. This negative lens element may be considered to be part of the power lens unit. The negative lens elements have weak optical power at the axis of the lens but are of generally increasing negative optical power from the optical axis to the clear apertures of the negative lens elements to contribute to proper color correction of the lens, particularly axial chromatic aberration adjacent the full aperture. The intermediate positive power lens unit may comprise one or two positive elements depending upon the application and the manner in which the power is to be distributed to minimize aberrations. A lens embodying the invention is capable of maintaining a high image quality over a large range of magnifications by moving the first and second lens units form the image end in predetermined differential relationship.
Inventors
- 👤 Jacob Moskovich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:16
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/12; G02B13/00; G02B13/18
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
127 words
A projection lens for a cathode ray tube comprising a rear lens unit adopted to be closely coupled to a cathode ray tube at the object end thereof, said lens unit having a strongly concave image side surface, a front lens unit on the image side of said lens comprising a positive image side element having a dispersion similar to the dispersion of crown glass followed by a closely spaced negative element of high dispersion similar to the dispersion of flint glass, and another lens unit providing substantially all of the positive optical power of said lens intermediate said front and rear lens units, said another lens unit including a negative element of high dispersion similar to the dispersion of flint glass on the object side thereof.
Claim 2
Dependent Claim
127 words
A projection lens for a cathode ray tube comprising a rear lens unit adopted to be closely coupled to a cathode ray tube at the object end thereof, said lens unit having a strongly concave image side surface, a front lens unit on the image side of said lens comprising a positive image side element having a dispersion similar to the dispersion of crown glass followed by a closely spaced negative element of high dispersion similar to the dispersion of flint glass, and another lens unit providing substantially all of the positive optical power of said lens intermediate said front and rear lens units, said another lens unit including a negative element of high dispersion similar to the dispersion of flint glass on the object side thereof.
Claim 3
Dependent Claim
18 words
The lens of claim 1 where said another lens unit comprises two positive elements both having spherical surfaces.
Claim 4
Dependent Claim
56 words
The lens of claim 1 further including a corrector lens unit of weak optical power having at least one aspherical surface positioned between said rear lens unit and said another lens unit so that the axial marginal rays from the long conjugate side of said lens intersect said corrector lens unit below the clear aperture thereof.
Claim 5
Dependent Claim
56 words
The lens of claim 3 where said front lens unit and said another lens unit move in fixed relation and said rear lens unit together with said corrector lens unit move in fixed relation but differentially with respect to said front lens unit and said another lens unit to vary the focal length of said lens.
Claim 6
Dependent Claim
41 words
The lens of claim 1 where the absolute value of the optical power of said negative lens element of said front lens unit increases from the optical axis to the clear aperture thereof due to at least one aspheric surface thereof.
Claim 7
Dependent Claim
26 words
The lens of claim 1 where said lens elements of said front lens unit contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 8
Dependent Claim
25 words
The lens of claim 1 where the elements of said another lens unit contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 9
Dependent Claim
51 words
The lens of claim 1 where said negative lens element of said front lens unit changes in optical power with height from the optical axis of the lens to contribute to correction of axial chromatic aberration in combination with the power of the preceding positive element of said front lens group.
Claim 10
Dependent Claim
32 words
The lens of claim 1 where said front lens unit and said another lens unit move in the same direction but at differential rates to vary the focal length of said lens.
Claim 11
Dependent Claim
84 words
A projection lens for a cathode ray tube comprising from the image end, a first positive lens element having at least one aspheric surface followed closely by a second negative lens element of high dispersion having at least one aspheric surface a third strongly positive lens element followed by a fourth negative lens element having at least one aspheric surface, and a fifth negative lens unit having a strongly concave image side surface and adapted to be closely coupled to a cathode ray tube.
Claim 12
Dependent Claim
84 words
A projection lens for a cathode ray tube comprising from the image end, a first positive lens element having at least one aspheric surface followed closely by a second negative lens element of high dispersion having at least one aspheric surface a third strongly positive lens element followed by a fourth negative lens element having at least one aspheric surface, and a fifth negative lens unit having a strongly concave image side surface and adapted to be closely coupled to a cathode ray tube.
Claim 13
Dependent Claim
26 words
The lens of claim 10 further including another positive lens element closely adjacent said third lens element on the image side of said third lens element.
Claim 14
Dependent Claim
57 words
The lens of claim 10 further including a corrector lens unit of weak optical power having at least one aspherical surface positioned between said fourth lens element and said fifth negative lens unit so that the axial marginal rays from the long conjugate side of said lens intersect said corrector lens element below the clear aperture thereof.
Claim 15
Dependent Claim
38 words
The lens of claim 10 where the absolute value of the optical power of said second negative lens element increases from the optical axis to the clear aperture thereof due to said at least one aspheric surface thereof.
Claim 16
Dependent Claim
24 words
The lens of claim 10 where said first and second lens elements contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 17
Dependent Claim
24 words
The lens of claim 10 where said third and fourth lens elements contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 18
Dependent Claim
36 words
The lens of claim 10 where said negative lens elements change in absolute optical power with height from the axis of the lens to the clear aperture thereof due to the aspheric surfaces on each element.
Claim 19
Dependent Claim
165 words
A projection lens for a cathode ray tube comprising a first positive element having at least one aspheric surface, a second negative lens element closely spaced to said first element having at least one aspheric surface and being of stronger absolute optical power adjacent the clear aperture thereof than at the optical axis, said second element having a high dispersion similar to the dispersion of flint glass, said first lens element having a dispersion similar to the dispersion of crown glass, a third strongly positive lens element having a dispersion similar to the dispersion of crown glass, a fourth negative lens element closely spaced to said third lens element having a dispersion similar to the dispersion of flint glass, said fourth lens element having at least one aspheric surface which increases in absolute optical power from the optical axis to the clear aperture thereof, and a lens unit having a strongly concave image side surface adapted to be closely coupled to a cathode ray tube.
Claim 20
Dependent Claim
165 words
A projection lens for a cathode ray tube comprising a first positive element having at least one aspheric surface, a second negative lens element closely spaced to said first element having at least one aspheric surface and being of stronger absolute optical power adjacent the clear aperture thereof than at the optical axis, said second element having a high dispersion similar to the dispersion of flint glass, said first lens element having a dispersion similar to the dispersion of crown glass, a third strongly positive lens element having a dispersion similar to the dispersion of crown glass, a fourth negative lens element closely spaced to said third lens element having a dispersion similar to the dispersion of flint glass, said fourth lens element having at least one aspheric surface which increases in absolute optical power from the optical axis to the clear aperture thereof, and a lens unit having a strongly concave image side surface adapted to be closely coupled to a cathode ray tube.
Claim 21
Dependent Claim
24 words
The lens of claim 17 further including another positive lens elements on the image side of said third lens element and closely spaced thereto.
Claim 22
Dependent Claim
55 words
The lens of claim 17 further including a corrector lens element of weak optical power having at least one aspheric surface positioned between said fourth lens element and said lens unit such that the axial marginal rays from the long conjugate side of said lens intersect said corrector lens element below the clear aperture thereof,
Claim 23
Dependent Claim
24 words
The lens of claim 17 where said lens first and second elements contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 24
Dependent Claim
23 words
The lens of claim 17 where said third and fourth elements contribute to correction of axial chromatic aberration adjacent the clear apertures thereof.
Claim 25
Dependent Claim
41 words
The lens of claim 17 where said second and fourth negative lens elements change in absolute optical power with height from the axis of the lens to the clear aperture thereof due to at least one aspheric surface on each element.
Claim 26
Dependent Claim
107 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first lens unit of weak power, including a positive element followed by a closely spaced negative element having at least one aspherical surface and made out of material with higher dispersion than said positive element; a second lens unit providing most of the positive power of the lens and including at least one positive element followed by a closely spaced negative element having higher dispersion than the preceding positive element; and a third lens unit of negative power and including a strong negative element in the vicinity of a cathode ray tube.
Claim 27
Dependent Claim
107 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first lens unit of weak power, including a positive element followed by a closely spaced negative element having at least one aspherical surface and made out of material with higher dispersion than said positive element; a second lens unit providing most of the positive power of the lens and including at least one positive element followed by a closely spaced negative element having higher dispersion than the preceding positive element; and a third lens unit of negative power and including a strong negative element in the vicinity of a cathode ray tube.
Claim 28
Dependent Claim
14 words
The lens of claim 23 where said second lens unit comprises two positive elements.
Claim 29
Dependent Claim
29 words
The lens of claim 23 further including a corrector lens element positioned between said second and said third lens units, said corrector element having at least one aspherical surface.
Claim 30
Dependent Claim
29 words
The lens of claim 23 where the optical power of the negative lens element in said first lens unit changes from the optical axis to the clear aperture thereof.
Claim 31
Dependent Claim
30 words
The lens of claim 23 where the optical power of the negative lens element in said second lens unit gradually changes from the optical axis to the clear aperture thereof.
Claim 32
Dependent Claim
30 words
The lens of claim 23 where said positive and negative lens elements of said first and second units contribute to correction of axial chromatic aberration adjacent the clear aperture thereof.
Claim 33
Dependent Claim
78 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first positive lens element having at least one aspherical surface followed closely by a second negative lens element of high dispersion having at least one aspherical surface, a third strongly positive lens element followed by a fourth negative lens element of high dispersion having at least one aspherical surface, and a fifth strongly negative lens component having a strongly concave image side surface.
Claim 34
Dependent Claim
78 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first positive lens element having at least one aspherical surface followed closely by a second negative lens element of high dispersion having at least one aspherical surface, a third strongly positive lens element followed by a fourth negative lens element of high dispersion having at least one aspherical surface, and a fifth strongly negative lens component having a strongly concave image side surface.
Claim 35
Dependent Claim
17 words
The lens of claim 29 further including another positive lens element closely adjacent said third lens element.
Claim 36
Dependent Claim
59 words
The lens of claim 29 further including a corrector lens element having at least one aspherical surface positioned between said fourth lens element and said fifth strongly negative component adjacent to a cathode ray tube so that the axial marginal rays from the long conjugate side of said lens intersect said corrector lens element below the clear aperture thereof.
Claim 37
Dependent Claim
36 words
The lens of claim 29 where said negative lens elements change in power with height from the axis of the lens to the clear aperture thereof due to at least one aspherical surface on each element.
Claim 38
Dependent Claim
18 words
The lens of claim 29 where said first and second elements contribute to correction of longitudinal chromatic aberration.
Claim 39
Dependent Claim
18 words
The lens of claim 29 where said third and fourth elements contribute to correction of longitudinal chromatic aberration.
Claim 40
Dependent Claim
170 words
A projection lens for a cathode ray tube comprising a first positive element having at least one aspheric surface, a second negative lens element closely spaced to said first element and having at least one aspheric surface and being of stronger absolute power adjacent the clear aperture thereof than at the optical axis, said second element having a high dispersion similar to the dispersion of flint glass, said first lens element having a dispersion similar to the dispersion of crown glass, a third strongly positive element with a dispersion similar to the dispersion of crown glass, a fourth negative lens element closely spaced to said third lens element having a dispersion similar to the dispersion of flint glass, said fourth lens element having at least one aspherical surface and being of stronger absolute power adjacent the clear aperture thereof than at the optical axis, and a fifth negative lens having a strongly concave surface facing the long conjugate side and adapted to be closely coupled to a cathode ray tube.
Claim 41
Dependent Claim
170 words
A projection lens for a cathode ray tube comprising a first positive element having at least one aspheric surface, a second negative lens element closely spaced to said first element and having at least one aspheric surface and being of stronger absolute power adjacent the clear aperture thereof than at the optical axis, said second element having a high dispersion similar to the dispersion of flint glass, said first lens element having a dispersion similar to the dispersion of crown glass, a third strongly positive element with a dispersion similar to the dispersion of crown glass, a fourth negative lens element closely spaced to said third lens element having a dispersion similar to the dispersion of flint glass, said fourth lens element having at least one aspherical surface and being of stronger absolute power adjacent the clear aperture thereof than at the optical axis, and a fifth negative lens having a strongly concave surface facing the long conjugate side and adapted to be closely coupled to a cathode ray tube.
Claim 42
Dependent Claim
25 words
The lens of claim 35 further including another positive lens element on the long conjugate side of the third lens element and closely spaced thereto.
Claim 43
Dependent Claim
27 words
The lens of claim 35 further including a corrector lens element having at least one aspheric surface positioned between said fourth lens element and said fifth lens.
Claim 44
Dependent Claim
133 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first unit of a weak power and including at least one positive element of low dispersion and one negative element of high dispersion and having at least one aspherical surface; a second lens unit providing most of the positive power of the lens and including at least one positive element of low dispersion and one negative element of high dispersion, a third lens unit of strong negative power adapted to be closely coupled to a cathode ray tube, said lens being capable of changing magnifications by moving said first and said second lens units along the optical axis in a predetermined manner relative to each other while keeping said third unit stationary relative to a cathode ray tube.
Claim 45
Dependent Claim
133 words
A projection lens for a cathode ray tube comprising from the long conjugate side a first unit of a weak power and including at least one positive element of low dispersion and one negative element of high dispersion and having at least one aspherical surface; a second lens unit providing most of the positive power of the lens and including at least one positive element of low dispersion and one negative element of high dispersion, a third lens unit of strong negative power adapted to be closely coupled to a cathode ray tube, said lens being capable of changing magnifications by moving said first and said second lens units along the optical axis in a predetermined manner relative to each other while keeping said third unit stationary relative to a cathode ray tube.
Claim 46
Dependent Claim
52 words
The lens of claim 38 further including a corrector lens unit having at least one aspherical surface and positioned between said second and said third lens units, said corrector lens unit being kept stationary with respect to said third unit while said first and second lens units are moved to change magnification.
Claim 47
Dependent Claim
49 words
The lens of claim 38 where said negative elements in said first and second lens units change in power with height from the axis of the lens to the clear aperture thereof to contribute to correction of axial chromatic aberration in combination with the power of the preceding element.
References Cited (Backward Citations)
GB593514A
Cited
US3429997A
Cited
GB1269133A
Cited
US3800085A
Cited
US4530575A
Cited
JPS5917082A
Cited
US4733953A
Cited
US4767199A
Cited
US4758074A
Cited
US4815831A
Cited
US4778264A
Cited
US4776681A
Cited
US4792218A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |