← Back to Patent Explorer
US4621898A Expired / Lapsed US ⏱️ 0.0 years remaining

Directional optical filter

Assignee: Honeywell International Inc
•
Filing: 1983-03-17
•
Granted: 1986-11-11
•
Expires: 2003-03-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A directional filter is constructed with a plurality of grooves (15) extending into a plate (13) from one side (16) thereof. The grooves (15) have a light absorbing characteristic which causes them to absorb light impinging upon the grooves, particularly light impinging upon the grooves (15) from within the plate (13). Since all light passing beyond a certain angle φ must impinge upon the grooves (13), and only a small percentage of light passing parallel to the cut of the grooves (15) would impinge upon the grooves (15), the filter has a high ratio of attenuation of unwanted versus wanted light.

Inventors

  • 👤 Richard L. Cohen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 20:05
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 148 words
Filter for selectively admitting radiant energy to pass therethrough including at least one radiant energy transmitting media having first and second sides, and a surface of the media on the first side, wherein an image on one side of the media can be viewed from the other side, characterized by: said surface being interrupted by a plurality of light-absorbing grooves, the plurality of grooves extending from said surface, extending less than completely through the media and arranged in a pattern, the grooves having a characteristic of absorbing said radiant energy impinging thereon from within the media, such that radiant energy passing said surface from a pre-determined angle from normal to said surface is substantially absorbed and radiant energy passing said surface from less than said pre-determined angle and not impinging upon the grooves is transmitted in accordance with radiant energy transmitting characteristics of said media for that energy.
Claim 2
Dependent Claim 148 words
Filter for selectively admitting radiant energy to pass therethrough including at least one radiant energy transmitting media having first and second sides, and a surface of the media on the first side, wherein an image on one side of the media can be viewed from the other side, characterized by: said surface being interrupted by a plurality of light-absorbing grooves, the plurality of grooves extending from said surface, extending less than completely through the media and arranged in a pattern, the grooves having a characteristic of absorbing said radiant energy impinging thereon from within the media, such that radiant energy passing said surface from a pre-determined angle from normal to said surface is substantially absorbed and radiant energy passing said surface from less than said pre-determined angle and not impinging upon the grooves is transmitted in accordance with radiant energy transmitting characteristics of said media for that energy.
Claim 3
Dependent Claim 14 words
Apparatus as described in claim 1 further characterized by the radiant energy being light.
Claim 4
Dependent Claim 15 words
Apparatus as described in claim 1 further characterized by said media being a solid material.
Claim 5
Dependent Claim 15 words
Apparatus as described in claim 1 further characterized by the media being a flat plate.
Claim 6
Dependent Claim 25 words
Apparatus as described in claim 1 further characterized by the media having a characteristic of selectively absorbing light which does not impinge upon the grooves.
Claim 7
Dependent Claim 26 words
Apparatus as described in claim 1 further characterized by th media having a characteristic of partially absorbing that light which does not impinge upon the grooves.
Claim 8
Dependent Claim 21 words
Apparatus as defined in claim 1 further characterized by an anti-glare coating, which is applied to one side of the media.
Claim 9
Dependent Claim 33 words
Apparatus as defined in claim 1 further characterized by the grooves being arranged in a pattern such that the grooves extend along said surface in a parallel direction with respect to each other.
Claim 10
Dependent Claim 65 words
Apparatus as defined in claim 8 further characterized by: a second radiant energy transmitting media, having a second set of grooves cut therein in a parallel direction with respect to each other; the second media being disposed adjacent to one of the sides of said one media so that the grooves in the second media are substantially orthogonal to the grooves in said one media.
Claim 11
Dependent Claim 41 words
Apparatus as described in claim 8 further characterized by a second set of grooves extending in a parallel direction with respect to each other, the second set of grooves being disposed in an orthogonal direction to the first set of grooves.
Claim 12
Dependent Claim 26 words
Apparatus as claimed in claim 1 further characterized by the grooves being arranged in a pattern such that adjacent grooves form concentric circles on said surface.
Claim 13
Dependent Claim 23 words
Apparatus as described in claim 1 further characterized by the grooves extending from said surface at an angle from normal to the surface.
Claim 14
Dependent Claim 13 words
Apparatus as described in claim 1 further characterized by the media being glass.
Claim 15
Dependent Claim 13 words
Apparatus as described in claim 1 further characterized by the media being plastic.
Claim 16
Dependent Claim 14 words
Apparatus as described in claim 14 further characterized by the media being methyl methacrylate.
Claim 17
Dependent Claim 13 words
Apparatus as described in claim 14 further characterized by the media being epoxy.
Claim 18
Dependent Claim 168 words
A video display including a cathode ray tube and a filter for selectively admitting radiant energy to pass therethrough, the filter including at least one radiant energy transmitting media having first and second sides and a surface of the media on the first side wherein an image on one side of the media can be viewed from the other side, characterized by: said surface being interrupted by a plurality of light-absorbing grooves which are cut into said surface so as to extend less than completely through the media, the plurality of grooves extending from said surface and arranged in a pattern, the grooves having a characteristic of absorbing said radiant energy impinging thereon from within the media, such that radiant energy passing said surface from pre-determined angle from normal to said surface is substantially absorbed and radiant energy passing said surface form less than said pre-determined angle and not impinging upon the grooves is transmitted in accordance with radiant energy transmitting characteristics of said media for that energy.
Claim 19
Dependent Claim 168 words
A video display including a cathode ray tube and a filter for selectively admitting radiant energy to pass therethrough, the filter including at least one radiant energy transmitting media having first and second sides and a surface of the media on the first side wherein an image on one side of the media can be viewed from the other side, characterized by: said surface being interrupted by a plurality of light-absorbing grooves which are cut into said surface so as to extend less than completely through the media, the plurality of grooves extending from said surface and arranged in a pattern, the grooves having a characteristic of absorbing said radiant energy impinging thereon from within the media, such that radiant energy passing said surface from pre-determined angle from normal to said surface is substantially absorbed and radiant energy passing said surface form less than said pre-determined angle and not impinging upon the grooves is transmitted in accordance with radiant energy transmitting characteristics of said media for that energy.

References Cited (Backward Citations)

US2053173A Cited
US2909770A Cited
US3784282A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-11-10 1990-05-12 1990-11-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-11-10 1994-05-12 1994-11-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-11-10 1998-05-12 1998-11-11 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag