Patent US3868173A successfully refreshed from Google Patents.
US3868173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Objective lens assembly for projection television
Assignee: Individual
•
Filing: 1973-01-18
•
Granted: 1975-02-25
•
Expires: 1993-01-18
Abstract
Abstract A high-speed objective lens assembly for projecting the image appearing on a television display tube onto a remote screen or for like purposes. The lens assembly is constituted by a group of four lenses constituting the main part of the objective, the fifth lens taking the form of a field flattener adapted to cooperate with the curved screen of the display tube. The aperture ratio is substantially 1: 1.5 and the maximum angle of field is at least + OR - 20 degrees.
Inventors
- 👤 John R Miles
- 👤 Grant M Miles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:02
CPC Classifications
G; G02; G02B; G02B13/00; G02B13/18; G02B13/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
121 words
A high-speed objective lens assembly adapted to project the image appearing on the screen of a television display tube onto a remote screen, said assembly comprising at least five lens elements formed of transparent thermoplastic material having a high order of light permeability, wherein the first lens element is concave-convex, the second lens element is double convex, the third lens element is double concave, the fourth lens element is double convex, and the fifth lens element which is adjacent said screen is double concave, said assembly having a speed of at least f: 1.5, the air space between the fourth and fifth lens elements being more than twice as great as the air space between the third and fourth lens elements.
Claim 2
Dependent Claim
121 words
A high-speed objective lens assembly adapted to project the image appearing on the screen of a television display tube onto a remote screen, said assembly comprising at least five lens elements formed of transparent thermoplastic material having a high order of light permeability, wherein the first lens element is concave-convex, the second lens element is double convex, the third lens element is double concave, the fourth lens element is double convex, and the fifth lens element which is adjacent said screen is double concave, said assembly having a speed of at least f: 1.5, the air space between the fourth and fifth lens elements being more than twice as great as the air space between the third and fourth lens elements.
Claim 3
Dependent Claim
24 words
An objective lens assembly as set forth in claim 1 in which at least four of said lens elements are made of transparent acrylic.
Claim 4
Dependent Claim
24 words
An objective lens assembly as set forth in claim 1, in which at least one of said lens elements is made of transparent polystyrene.
Claim 5
Dependent Claim
32 words
An assembly as set forth in claim 2, wherein the second surface of the second lens element has a different radius of curvature from the first surface of the third lens element.
Claim 6
Dependent Claim
24 words
An objective lens assembly comprising six lens elements A, B, C, D, E and F, made and spaced substantially according to the following data:
Claim 7
Dependent Claim
24 words
An objective lens assembly comprising six lens elements A, B, C, D, E and F, made and spaced substantially according to the following data:
Claim 8
Dependent Claim
82 words
An assembly as set forth in claim 5, wherein R1, R6 and R9 are vertex radii of curvature, as these three surfaces are aspheric, and the shapes of these three surfaces are defined by the formula: Z C.Y2/1+ Square Root 1-(K + 1) . C2 . Y2 +dY4+eY6+fY8+gY10 the numerical values for insertion into the above formula for calculating values of Z for each value of Y are found in the following tables for each of the surfaces R1, R6 and R9:
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |