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US4657348A
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Arrangement to remove reflection from liquid crystal displays (LCD's)
Assignee: Robert Bosch GmbH
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Filing: 1983-12-24
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Granted: 1987-04-14
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Expires: 2003-12-24
Abstract
Abstract An arrangement to remove reflection from liquid crystal displays is proposed. The arrangement includes a liquid crystal cell (11) and a cover disk (18) disposed obliquely thereto, spaced apart from and in front of the liquid crystal cell (11), the cover disk bearing a circular polarizer (19). In the front, a λ/4 retarding foil (16) is disposed on the liquid crystal cell (11), cooperating with the circular polarizer (19) in such a manner that a practically complete removal of reflection for the light passing through the cover disk (18) from outside takes place (FIG. 1).
Inventors
- 👤 Wolfgang Ziegler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:39
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1335; G02B; G02B27/00; G02B27/28; G02B27/281; G09; G09F; G09F9/00; G09F9/30; G09F9/35; G02F2203/00; G02F2203/09
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
115 words
Arrangement to remove reflection from liquid crystal displays (10) comprising a substantially planar liquid crystal cell (11, 11a); a cover disk (18) disposed spaced apart from, in front of, and at an oblique angle with respect to the plane of the liquid crystal cell (11, 11a); a circular polarizer (19) applied to a face of said cover disk closest to said liquid crystal cell (11,11a); and a λ/4 retarding foil (16) disposed on a front face of the liquid crystal cell (11, 11a) closest to said cover disk (18), said λ/4 retarding foil and said circular polarizer, cooperating to linearly polarize light which has passed through both the λ/4 retarding foil and the circular polarizer.
Claim 2
Dependent Claim
115 words
Arrangement to remove reflection from liquid crystal displays (10) comprising a substantially planar liquid crystal cell (11, 11a); a cover disk (18) disposed spaced apart from, in front of, and at an oblique angle with respect to the plane of the liquid crystal cell (11, 11a); a circular polarizer (19) applied to a face of said cover disk closest to said liquid crystal cell (11,11a); and a λ/4 retarding foil (16) disposed on a front face of the liquid crystal cell (11, 11a) closest to said cover disk (18), said λ/4 retarding foil and said circular polarizer, cooperating to linearly polarize light which has passed through both the λ/4 retarding foil and the circular polarizer.
Claim 3
Dependent Claim
57 words
Arrangement according to claim 1, wherein said liquid crystal cell (11,11a) has a back side, remote from said cover disk (18); a linear polarizer (14) is disposed on said back side; a transflector (15) is disposed behind said linear polarizer (14); and a backlight (21) is provided, disposed behind said transflector (15), and illuminates triggered display elements.
Claim 4
Dependent Claim
36 words
Arrangement according to claim 1 or 2, characterized in that the λ/4 retarding foil (16) is applied together with a linear-polarizing layer (25), as a circular polarizer, to the front of the liquid crystal cell (11a).
Claim 5
Dependent Claim
35 words
Arrangement according to claim 3, characterized in that the linear-polarizing layer (25) is applied to the front surface of the liquid crystal cell (11a) and the λ/4 retarding foil (16) faces the cover disk (18).
Claim 6
Dependent Claim
51 words
Arrangement according to claim 1, wherein said circular polarizer (19) on said cover disk (18) comprises a linear polarizer (19a); and a λ/4 retarding foil (19b), said retarding foil (19b) being disposed between said linear polarizer (19a) and the retarding foil (16) on the front of said liquid crystal cell (11,11a).
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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |