US4229783A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backlight for electrooptic display
Assignee: Timex Group USA Inc
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Filing: 1979-03-12
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Granted: 1980-10-21
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Expires: 1999-03-12
Abstract
Abstract A backlight for an electrooptic display, such as a liquid crystal display, serves to diffuse and distribute light from a point source, such as an incandescent bulb, over a broad, flat thin area providing backlighting for the display. The backlight employs a transparent light transmitting member with a slot or recess for the light source, wrapped in a thin transluscent sheet which covers both front and back surfaces and the edges to serve as a transflector.
Inventors
- 👤 Noel Eberhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:34
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02F1/1336; G02F1/133615
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
134 words
In an illuminated electrooptic display of the type having a backlight member disposed beneath a passive light transmissive electrooptic display, the improvement in said backlight comprising: a flat substantially transparent light transmitting member having opposed first and second parallel surfaces and having edge portions, said light transmitting member defining a recess opening in at least one of said surfaces, a thin sheet of transluscent material completely enveloping said light transmitting member covering said first and second surfaces and said edges and adhered to by an adhesive, said transluscent material comprising a foldable sheet of material selected from the group consisting of polypropylene or polystyrene, and defining a hole adapted to be aligned with said recess when the sheet is folded to envelop the light transmitting member; and a light source disposed in said recess.
Claim 2
Dependent Claim
134 words
In an illuminated electrooptic display of the type having a backlight member disposed beneath a passive light transmissive electrooptic display, the improvement in said backlight comprising: a flat substantially transparent light transmitting member having opposed first and second parallel surfaces and having edge portions, said light transmitting member defining a recess opening in at least one of said surfaces, a thin sheet of transluscent material completely enveloping said light transmitting member covering said first and second surfaces and said edges and adhered to by an adhesive, said transluscent material comprising a foldable sheet of material selected from the group consisting of polypropylene or polystyrene, and defining a hole adapted to be aligned with said recess when the sheet is folded to envelop the light transmitting member; and a light source disposed in said recess.
Claim 3
Dependent Claim
41 words
The combination according to claim 1, wherein said light transmitting member is selected from the group consisting of acrylic, polycarbonate or polystyrene plastics, and wherein said transluscent sheet is comprised of white polypropylene material on the order of 0.0015 inches thick.
Claim 4
Dependent Claim
128 words
An improved backlight for an illuminated display of the type having a backlight disposed beneath a passive light transmissive electrooptic display, said improvement comprising: a light transmitting member of clear plastic having upper and lower opposed flat surfaces with intersecting edges, and having an oblong recess formed in the lower surface along one of said edges; a transluscent transflector sheet member completely enveloping the upper and lower surfaces and edges of said light transmitting member, said sheet member being formed from a single foldable sheet of white polypropylene having portions adapted to cover the first and second surfaces and having tab portions adapted to cover said edges, said sheet having a transparent adhesive film on one side; and an incandescent lamp member adapted to fit within said recess.
Claim 5
Dependent Claim
128 words
An improved backlight for an illuminated display of the type having a backlight disposed beneath a passive light transmissive electrooptic display, said improvement comprising: a light transmitting member of clear plastic having upper and lower opposed flat surfaces with intersecting edges, and having an oblong recess formed in the lower surface along one of said edges; a transluscent transflector sheet member completely enveloping the upper and lower surfaces and edges of said light transmitting member, said sheet member being formed from a single foldable sheet of white polypropylene having portions adapted to cover the first and second surfaces and having tab portions adapted to cover said edges, said sheet having a transparent adhesive film on one side; and an incandescent lamp member adapted to fit within said recess.
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) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |