US3659918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color separating prism system
Assignee: US Philips Corp
•
Filing: 1970-03-24
•
Granted: 1972-05-02
•
Expires: 1990-03-24
Abstract
Abstract A color separating prism system for a television camera including several dichroic layers arranged at angles of less than 30* to a plane normal to the optical axis, which layers are successively struck by the light rays which traverse the prism system, light within a given wavelength range being reflected at each respective layer. Such a color separating prism system increases the efficiency of the incident light and renders the response times of the three channels more equal to one another and to the lowest response time by providing at least one partially reflecting layer in the prism system in an airgap adjoining a dichroic layer.
Inventors
- 👤 Sing Liong Tan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:58
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/1006; G02B27/1013; G02B27/14; G02B27/145
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
211 words
An optical system for a color television camera having a camera tube for each of a plurality of component colors of an object comprising an objective lens and between the objective lens and each tube, a color separating prism system having a nonreflecting optical axis and including a plurality of prisms successively traversed by light, successive prisms being separated from one another traversed air spaces bounded by surfaces of the prisms which intersect the non-reflecting optical axis and at least one of said prisms being separated from said objective lens by an air space, a first dichroic layer adjacent a bounding surface adjoining one of said air spaces and intersecting the non-reflecting optical axis, a second dichroic layer adjacent a bounding surface adjoining another of said air spaces and intersecting the non-reflecting optical axis, said bounding surfaces and said dichroic layers each forming angles of less than 30* with planes which are at right angles to the nonreflecting optical axis, said prisms being so positioned relative to one another that light reflected by a dichroic mirror is totally reflected by an adjacent bounding surface, and a partially reflecting layer adjoining a bounding surface opposite one of said dichroic layers for reflecting a portion of the light transmitted by said dichroic layer.
Claim 2
Dependent Claim
211 words
An optical system for a color television camera having a camera tube for each of a plurality of component colors of an object comprising an objective lens and between the objective lens and each tube, a color separating prism system having a nonreflecting optical axis and including a plurality of prisms successively traversed by light, successive prisms being separated from one another traversed air spaces bounded by surfaces of the prisms which intersect the non-reflecting optical axis and at least one of said prisms being separated from said objective lens by an air space, a first dichroic layer adjacent a bounding surface adjoining one of said air spaces and intersecting the non-reflecting optical axis, a second dichroic layer adjacent a bounding surface adjoining another of said air spaces and intersecting the non-reflecting optical axis, said bounding surfaces and said dichroic layers each forming angles of less than 30* with planes which are at right angles to the nonreflecting optical axis, said prisms being so positioned relative to one another that light reflected by a dichroic mirror is totally reflected by an adjacent bounding surface, and a partially reflecting layer adjoining a bounding surface opposite one of said dichroic layers for reflecting a portion of the light transmitted by said dichroic layer.
Claim 3
Dependent Claim
21 words
A color separating prism system as claimed in claim 1 wherein an air space is disposed behind the first dichroic layer.
Claim 4
Dependent Claim
24 words
A color separating prism system as claimed in claim 1 wherein the said partially reflecting layer comprises a transparent layer having light-reflecting domains therein.
Claim 5
Dependent Claim
20 words
A color separating prism system as claimed in claim 1 wherein the said partially reflecting layer is spectrally neutrally reflecting.
Claim 6
Dependent Claim
22 words
A color separating prism system as claimed in claim 1 wherein the reflection of the said partially reflecting layer is wavelength dependent.
Claim 7
Dependent Claim
21 words
A color separating prism system as claimed in claim 1 wherein an air space is disposed behind the second dichroic layer.
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |