US4101807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for controlling the temperature of low pressure metal or metal halide lamps
Assignee: Xerox Corp
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Filing: 1976-03-22
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Granted: 1978-07-18
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Expires: 1996-03-22
Abstract
Abstract A low pressure metal or metal halide vapor lamp for photocopying applications. The low pressure sodium vapor lamp is operated in a continuous mode and provides illumination of increased brightness and of a color (yellow) which is optimum for providing a copy which is an accurate representation of the original. An auxiliary heater is formed on the lamp to both decrease the warm-up time of the lamp and to control lamp temperature for optimum light output, an electrical control circuit being coupled to the heater to control the current therethrough.
Inventors
- 👤 Howard M. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:21
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
150 words
Apparatus for forming a latent electrostatic charge pattern on a photoconductive insulating medium, said latent electrostatic charge pattern corresponding to the radiation pattern projected from an information bearing member comprising: a charged photoconductive insulating member, a low pressure metal vapor source for generating radiation of a predetermined spectral line, said information bearing member being interposed in the optical path between said metal vapor source and said charged photoconductive insulating member, means for energizing said low pressure vapor source whereby radiation is emitted therefrom, said radiation exposing said information bearing member to selectively dissipate the charge on the surface of said photoconductive insulating member in accordance with the intensity of the radiation projected from said information bearing medium to form said latent electrostatic charge pattern, means for heating said metal vapor source to a predetermined temperature, and means coupled to said heating means for maintaining said temperature at said predetermined value.
Claim 2
Dependent Claim
150 words
Apparatus for forming a latent electrostatic charge pattern on a photoconductive insulating medium, said latent electrostatic charge pattern corresponding to the radiation pattern projected from an information bearing member comprising: a charged photoconductive insulating member, a low pressure metal vapor source for generating radiation of a predetermined spectral line, said information bearing member being interposed in the optical path between said metal vapor source and said charged photoconductive insulating member, means for energizing said low pressure vapor source whereby radiation is emitted therefrom, said radiation exposing said information bearing member to selectively dissipate the charge on the surface of said photoconductive insulating member in accordance with the intensity of the radiation projected from said information bearing medium to form said latent electrostatic charge pattern, means for heating said metal vapor source to a predetermined temperature, and means coupled to said heating means for maintaining said temperature at said predetermined value.
Claim 3
Dependent Claim
18 words
The apparatus as defined in claim 1 wherein said low pressure vapor source comprises a sodium vapor lamp.
Claim 4
Dependent Claim
78 words
The apparatus as defined in claim 2 wherein said low pressure sodium vapor lamp comprises: a discharge tube having spaced-apart electrodes and low pressure sodium vapor therein, means for coupling a signal to said electrodes of an amplitude sufficient to breakdown said sodium vapor and initiate a discharge between said electrodes, and means operably associated with said discharge tube for rapidly heating the sodium vapor therewithin to a predetermined value whereby the metal vaporization period is substantially reduced.
Claim 5
Dependent Claim
61 words
The apparatus as defined in claim 3 wherein said maintaining means comprises a variable power supply which is coupled to said lamp electrodes to initiate the discharge therebetween, said variable power supply being coupled to said heating means prior to the initiation of said discharge to rapidly heat the vapor to said predetermined value whereby the breakdown period is substantially reduced.
Claim 6
Dependent Claim
61 words
The apparatus as defined in claim 4 further including control means coupled to said variable power supply to adjust the output thereof to a value whereby said vapor is heated to said predetermined value prior to the initiation of said discharge, said control means being responsive to signals representing the current flowing through said heating means and the voltage applied thereto.
Claim 7
Dependent Claim
39 words
The apparatus as defined in claim 5 wherein said voltage and current signals provide a further signal which represents the resistance value of said heating means, said resistance value being directly related to the temperature of said vapor source.
Claim 8
Dependent Claim
109 words
Apparatus for controlling the operating temperature of a low pressure metal or metal halide vapor lamp in photocopying apparatus comprising: a low pressure metal vapor source including a discharge tube having spaced-apart electrodes and a low pressure metal vapor therein, means for applying an electrical signal to said electrodes of an amplitude sufficient to cause a breakdown of said vapor and to initiate a discharge between said electrodes, heating means operatively associated with said discharge tube for heating said vapor therewithin to a predetermined temperature; and means for applying an electrical signal to said heating means to energize said heating means and maintain said vapor at said predetermined temperature.
Claim 9
Dependent Claim
109 words
Apparatus for controlling the operating temperature of a low pressure metal or metal halide vapor lamp in photocopying apparatus comprising: a low pressure metal vapor source including a discharge tube having spaced-apart electrodes and a low pressure metal vapor therein, means for applying an electrical signal to said electrodes of an amplitude sufficient to cause a breakdown of said vapor and to initiate a discharge between said electrodes, heating means operatively associated with said discharge tube for heating said vapor therewithin to a predetermined temperature; and means for applying an electrical signal to said heating means to energize said heating means and maintain said vapor at said predetermined temperature.
Claim 10
Dependent Claim
63 words
The apparatus as defined in claim 7 wherein said electrical signal applying means includes a variable power supply operatively coupled to said source electrodes to initiate the discharge therebetween, said variable power supply being operatively coupled to said heating means prior to the initiation of said discharge to rapidly heat the vapor to said predetermined temperature to substantially reduce the metal vaporization period.
Claim 11
Dependent Claim
62 words
The apparatus as defined in claim 8 further including control means operatively coupled to said variable power supply to adjust the output thereof to a value whereby said vapor is heated to said predetermined temperature prior to the initiation of said discharge, said control means being responsive to signals representing the current flowing through said heating means and the voltage applied thereto.
Claim 12
Dependent Claim
39 words
The apparatus as defined in claim 9 wherein said voltage and current signals provide a further signal which represents the resistance value of said heating means, said resistance value being directly related to the temperature of said vapor source.
Claim 13
Dependent Claim
18 words
The apparatus as defined in claim 10 wherein said low pressure vapor source comprises a sodium vapor source.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |