US4890201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light transmitting plate member
Assignee: GENERALDIREKTORATET FOR DANSKE STATSBANER DSB
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Filing: 1988-12-22
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Granted: 1989-12-26
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Expires: 2008-12-22
Abstract
Abstract A light transmitting plate member for illuminated signals, illuminated tables or similar illuminated flat items and intended for uniform diffusion of light from a light source positioned at a side edge of the light transmitter which has a flat side and an opposing side which has a gradual slope. The plate member has a reduced thickness in the direction away from said side edge, with the opposite sides being produced with optically smooth surfaces as the light transmitting plate member includes transparent and light transparent material with specific optical properties. The side with the gradual slope is provided with a number of angled divisions which are defined by transverse divisional lines which run parallel to the side edge and which are positioned with either uniform intervals or with graded intervals which are reduced in the direction receeding from the side edge. The thickness of the light transmitting plate member at the transverse divisional lines corresponds to the thickness of the light transmitting plate member at the side edge, whose angled divisions from the divisional lines and in the direction away from the side edge have reduced thicknesses.
Inventors
- 👤 Nils Toft
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:44
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0033; G02B6/0035; G02B6/0038; G09; G09F; G09F13/00; G09F13/18; G09F2013/1804; G09F2013/1809; G09F2013/1813; Y; Y10; Y10S; Y10S362/00; Y10S362/812
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
200 words
A light transmitting plate member for illuminated signs, illuminated tables or a similar illuminated flat item and adapted for uniform diffusion of light from a light source position at a first side edge of a light transmitter having a substantially flat surface and an opposing surface having a gradual slope, the plate member having a reduced thickness in a direction away from said first side edge, said opposing surface including optically smooth surfaces including at least one of transparent and light transparent material with specific optical properties, wherein said opposing surface is provided with a plurality of angled divisions defined by transverse divisional lines extending parallel to said first side edge and positioned at one of uniform intervals or graded intervals which are reduced in the direction away from said first side edge, a height or a thickness of the light transmitting plate member at the transverse divisional lines is substantially equal to a thickness of the light transmitting plate member at said first side edge, and wherein angles of inclination subtended between the respective divisional lines and a plane extending parallel to said flat surface and in the direction away from said first side edge have a reducing thickness.
Claim 2
Dependent Claim
200 words
A light transmitting plate member for illuminated signs, illuminated tables or a similar illuminated flat item and adapted for uniform diffusion of light from a light source position at a first side edge of a light transmitter having a substantially flat surface and an opposing surface having a gradual slope, the plate member having a reduced thickness in a direction away from said first side edge, said opposing surface including optically smooth surfaces including at least one of transparent and light transparent material with specific optical properties, wherein said opposing surface is provided with a plurality of angled divisions defined by transverse divisional lines extending parallel to said first side edge and positioned at one of uniform intervals or graded intervals which are reduced in the direction away from said first side edge, a height or a thickness of the light transmitting plate member at the transverse divisional lines is substantially equal to a thickness of the light transmitting plate member at said first side edge, and wherein angles of inclination subtended between the respective divisional lines and a plane extending parallel to said flat surface and in the direction away from said first side edge have a reducing thickness.
Claim 3
Dependent Claim
54 words
A light transmitting plate member according to claim 1, wherein the angles of inclination are varied in such a manner that portions of the transmitting plate member between adjacent divisional lines are illuminated aproximately uniform by light diffusion from the first side edge and an opposite side edge of the light transmitting plate member.
Claim 4
Dependent Claim
69 words
A light transmitting plate member according to one of claims 1 or 2, wherein the light transmitting plate member has a thickness of between 5-15 mm, a length of about 200-1400 mm, and said angles of inclination have a range of about 0.1°-5° nearest said first side edge to about 5°-20° farthest from said first side edge in dependence upon a total length of the light transmitting plate member.
Claim 5
Dependent Claim
50 words
A light transmitting plate member according to claim 3, wherein said flat surface is adapted to be disposed facing an item to be illuminated, and wherein a reflector means is positioned adjacent said opposing surface for reflecting light directly through the light transmitting plate member toward the flat surface thereof.
Claim 6
Dependent Claim
22 words
A light transmitting plate member according to claim 4, wherein the light transmitting plate member has a thickness of about 10 mm.
Claim 7
Dependent Claim
22 words
A light transmitting plate member according to claim 5, wherein the light transmitting plate member has a length of about 1200 mm.
Claim 8
Dependent Claim
18 words
A light transmitting member according to claim 6, wherein the item to be illuminated is a sign plate.
Claim 9
Dependent Claim
19 words
A light transmitting plate member according to claim 6, wherein the plate member is made of an acrylic material.
References Cited (Backward Citations)
US2247969A
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US4059916A
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US4257084A
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US4432039A
Cited
US4642736A
Cited
US4791540A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |