US4132478A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illumination system for a photographic copying apparatus
Assignee: Durst Group AG
•
Filing: 1977-07-06
•
Granted: 1979-01-02
•
Expires: 1997-07-06
Abstract
Abstract A light-diffuser for a photographic copier such as an enlarger incorporates a closely contacting parallel row of elongated glass rods held between a pair of tracks. The rods are preferably of heat-resistant glass of round cross section. An additional row of such rods may be disposed parallel to the first row and staggered therefrom to improve the diffusion of a beam of light passing through them.
Inventors
- 👤 John G. Long
- 👤 Nicholas P. Watts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:25
CPC Classifications
G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/545
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
70 words
A light diffuser for a light projecting apparatus having a light source comprising a plurality of elongated lens elements of substantially uniform cross section, a holder for the lens elements disposing them in close contact with each other in a parallel row of transverse disposition in the projected light to diffuse it, and the lens elements each comprise an individual rigid rod whereby the resistance to thermal stress is improved.
Claim 2
Dependent Claim
70 words
A light diffuser for a light projecting apparatus having a light source comprising a plurality of elongated lens elements of substantially uniform cross section, a holder for the lens elements disposing them in close contact with each other in a parallel row of transverse disposition in the projected light to diffuse it, and the lens elements each comprise an individual rigid rod whereby the resistance to thermal stress is improved.
Claim 3
Dependent Claim
20 words
A light diffuser as set forth in claim 1 wherein the rods have ends and the ends are substantially coextensive.
Claim 4
Dependent Claim
18 words
A light diffuser as set forth in claim 1 wherein the holder comprises a pair of parallel rails.
Claim 5
Dependent Claim
25 words
A light diffuser as set forth in claim 3 wherein the holder includes means for resiliently pressing the rods in close contact with each other.
Claim 6
Dependent Claim
20 words
A light diffuser as set forth in claim 1 wherein the row of lens elements comprise a substantially rectangular array.
Claim 7
Dependent Claim
46 words
A light diffuser as set forth in claim 1 wherein a second closely contacting row of elongated rods is provided, and the second row being disposed parallel to the first row with its rods in a staggered arrangement relative to the rods in the first row.
Claim 8
Dependent Claim
20 words
A light diffuser as set forth in claim 1 wherein the lens elements each have a substantially circular cross section.
Claim 9
Dependent Claim
15 words
A light diffuser as set forth in claim 1 wherein the lens elements comprise glass.
Claim 10
Dependent Claim
15 words
A light diffuser as set forth in claim 8 wherein the glass is heat resistant.
Claim 11
Dependent Claim
17 words
A light diffuser as set forth in claim 1 wherein at least ten lens elements are provided.
Claim 12
Dependent Claim
17 words
A light diffuser as set forth in claim 1 wherein at least twenty lens elements are provided.
Claim 13
Dependent Claim
37 words
A light diffuser as set forth in claim 1 wherein the light projector has a light mixing duct having a light entrance, and the light diffuser is disposed in the path of light entering the light entrance.
Claim 14
Dependent Claim
95 words
A light diffuser for a light projecting apparatus comprising a plurality of elongated lens elements of substantially uniform cross section, a holder for the lens elements disposing them in close contact with each other in a parallel row for transverse disposition in the projected light to diffuse it, a second row of elongated lens elements are provided, the second row being disposed parallel and closely adjacent to the first row, each of the lens elements having centers, and the centers of the second row being offset substantially midway between the centers of the first row.
Claim 15
Dependent Claim
95 words
A light diffuser for a light projecting apparatus comprising a plurality of elongated lens elements of substantially uniform cross section, a holder for the lens elements disposing them in close contact with each other in a parallel row for transverse disposition in the projected light to diffuse it, a second row of elongated lens elements are provided, the second row being disposed parallel and closely adjacent to the first row, each of the lens elements having centers, and the centers of the second row being offset substantially midway between the centers of the first row.
References Cited (Backward Citations)
FR840130A
Cited
US3227044A
Cited
US3217594A
Cited
US3630609A
Cited
US3756712A
Cited
US3923394A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |