US4766515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic holder
Assignee: Agfa Gevaert NV
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Filing: 1987-09-24
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Granted: 1988-08-23
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Expires: 2007-09-24
Abstract
Abstract An electrostatic holder suitable for electrostatically adhering thereto paper and developed silver halide emulsion films, wherein said holder comprises in the following order: (1) an electrically insulating member carrying the hereinafter described elements (2) to (5), (2) an electrically conductive member acting as electrode, (3) a dielectric layer having a dielectric strength of at least 150 kV.cm and a thickness in the range of 10 to 1000 μm, (4) an electrically conductive member acting as electrode and having the form of a grid or electrically interconnected conductor strips, and (5) a covering layer having a surface resistivity of at least 10 9 ohm/square and a thickness of at most 100 μm, and wherein said interconnected conductor strips are grounded and put at a direct current potential difference with respect to said electrode (2).
Inventors
- 👤 Romain H. Bollen
- 👤 Jozef E. Marien
- 👤 Valentin G. Wissels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 03:56
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/60; G03G15/605; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/62; G03B27/6207; G03B27/6214
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
135 words
A supporting means capable of electrostatically holding or adhering thereto paper and developed silver halide emulsion films, wherein said means comprises in the following order: (1) an electrically insulating member carrying the hereinafter mentioned elements (2) to (5), (2) an electrically conductive member acting as electrode, (3) a dielectric layer having a dielectric strength of at least 150 kV.cm and a thickness in the range of 10 to 1000 μm, (4) an electrically conductive member acting as electrode and having the form of a grid or electrically interconnected conductor strips, and (5) a covering layer having a surface resistivity of at least 10 9 ohm/square and a thickness of at most 100 μm, and wherein said interconnected conductor strips are grounded and put at a direct current potential difference with respect to said electrode (2).
Claim 2
Dependent Claim
135 words
A supporting means capable of electrostatically holding or adhering thereto paper and developed silver halide emulsion films, wherein said means comprises in the following order: (1) an electrically insulating member carrying the hereinafter mentioned elements (2) to (5), (2) an electrically conductive member acting as electrode, (3) a dielectric layer having a dielectric strength of at least 150 kV.cm and a thickness in the range of 10 to 1000 μm, (4) an electrically conductive member acting as electrode and having the form of a grid or electrically interconnected conductor strips, and (5) a covering layer having a surface resistivity of at least 10 9 ohm/square and a thickness of at most 100 μm, and wherein said interconnected conductor strips are grounded and put at a direct current potential difference with respect to said electrode (2).
Claim 3
Dependent Claim
22 words
A supporting means according to claim 1, wherein the direct current potential difference is applied intermittently between said electrodes (2) and (4).
Claim 4
Dependent Claim
20 words
A supporting means according to claim 1, wherein the direct current voltage is in the range of 600 to 1500V.
Claim 5
Dependent Claim
25 words
A supporting means according to claim 1, wherein the direct current voltage is applied intermittently at intervals of 10 s "on" and 10 s "off".
Claim 6
Dependent Claim
35 words
A supporting means according to claim 1, wherein element (1) serving as supporting member for the electrode (2) is made of an electrically insulating material having a specific resistivity of at least 10 12 ohm.cm.
Claim 7
Dependent Claim
29 words
A supporting means according to claim 1, wherein the dielectric interlayer (3) is made of polyethylene terephtalate having a specific resistivity of 10 17 ohm.cm and dielectric constant 3.2.
Claim 8
Dependent Claim
24 words
A supporting means according to claim 1, wherein the thickness of the dielectric interlayer (3) is in the range of 50 to 200 μm.
Claim 9
Dependent Claim
33 words
A supporting means according to claim 1, wherein the covering layer (5) is firmly united to the electrode element (4) by a lamination procedure using an adhesive or glue of poor electrical conductivity.
Claim 10
Dependent Claim
28 words
A supporting means according to claim 1, wherein said means is transmissive to visible light in such a degree that its optical density is not larger than 0.2.
Claim 11
Dependent Claim
20 words
A supporting means according to claim 1, wherein the electrode members (2) and (4) are made of transparent conductive material.
Claim 12
Dependent Claim
21 words
A supporting means according to claim 1, wherein the electrode members are made of thinly vacuum deposited metal or metal oxide.
Claim 13
Dependent Claim
31 words
A supporting means according to claim 1, wherein the electrode member (4) is obtained by applying the conductor strips at a spatial frequency of at least 4 line pairs per mm.
Claim 14
Dependent Claim
24 words
A supporting means according to claim 1, wherein said means is arranged in a viewing illuminator for electrostatically holding developed silver halide emulsion films.
Claim 15
Dependent Claim
34 words
A supporting means according to claim 1, wherein said means is arranged in a copier, enlarger camera or process camera used in graphic art reproduction for electrostatically holding sheet originals and/or photographic sheet materials.
References Cited (Backward Citations)
US3571678A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |