US4573787A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exposure lamp control for image forming apparatus
Assignee: Toshiba Corp
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Filing: 1984-07-09
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Granted: 1986-03-04
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Expires: 2004-07-09
Abstract
Abstract In a copy machine with a variable copy magnification, light reflected from a document, which is exposed by an exposure lamp, is led to a photosensitive drum to form thereon a copy image of a predetermined size and also led to a photo detecting circuit to detect a density of the document and to control an amount of exposure. An exposure control circuit of the copy machine comprises a magnification setter for generating a magnification signal dependent on a magnification as selected, a control signal generating circuit for generating a control signal according to the magnification signal and the output signal from the photo detecting circuit and a power source circuit for applying a power voltage to the exposure lamp according to the control signal.
Inventors
- 👤 Takeshi Sanbayashi
- 👤 Hideshi Oushiden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:18
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/041; G03G15/0415
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
An image forming apparatus comprising: lamp means for exposing a document; magnification setting means for generating a magnification signal; means, connected to said magnification setting means, for forming an image of the document on a recording medium based on a light from the exposed document, a size of the image being determined by the magnification signal; memory means, connected to said magnification setting means, which stores digital data corresponding to various magnifications and produces the digital data in response to the magnification signal; and lamp control means, connected to said lamp means and memory means, for applying a power voltage to said lamp means in accordance with the digital data generated from said memory means.
Claim 2
Dependent Claim
115 words
An image forming apparatus comprising: lamp means for exposing a document; magnification setting means for generating a magnification signal; means, connected to said magnification setting means, for forming an image of the document on a recording medium based on a light from the exposed document, a size of the image being determined by the magnification signal; memory means, connected to said magnification setting means, which stores digital data corresponding to various magnifications and produces the digital data in response to the magnification signal; and lamp control means, connected to said lamp means and memory means, for applying a power voltage to said lamp means in accordance with the digital data generated from said memory means.
Claim 3
Dependent Claim
32 words
An apparatus according to claim 1, wherein said magnification setting means selects any one of the continuously differring magnifications, and the magnification signal corresponds to a set magnification in a one-to-one correspondence.
Claim 4
Dependent Claim
26 words
An apparatus according to claim 1, wherein said lamp control means comprises a D/A converter for generating an analog voltage signal corresponding to the digital data.
Claim 5
Dependent Claim
34 words
An apparatus according to claim 1, wherein said lamp control means comprises a limiter connected at the output terminal thereof to prevent that the power voltage is over the rating of said lamp means.
Claim 6
Dependent Claim
149 words
An image forming apparatus comprising: lamp means for exposing a document; magnification setting means for generating a magnification signal; detecting means for detecting a density of the document based on a light from the exposed document and for producing a density voltage corresponding to the detected density; means, connected to said magnification setting means, for forming an image of the document on a recording medium based on a light from the exposed document, a size of the image being determined by the magnification signal; memory means, connected to said magnification setting means, which stores digital data corresponding to various magnifications and produces the digital data in response to the magnification signal; and lamp control means, connected to said detecting means, lamp means and memory means, for applying a power voltage to said lamp means in accordance with the density voltage and the digital data generated from said memory means.
Claim 7
Dependent Claim
149 words
An image forming apparatus comprising: lamp means for exposing a document; magnification setting means for generating a magnification signal; detecting means for detecting a density of the document based on a light from the exposed document and for producing a density voltage corresponding to the detected density; means, connected to said magnification setting means, for forming an image of the document on a recording medium based on a light from the exposed document, a size of the image being determined by the magnification signal; memory means, connected to said magnification setting means, which stores digital data corresponding to various magnifications and produces the digital data in response to the magnification signal; and lamp control means, connected to said detecting means, lamp means and memory means, for applying a power voltage to said lamp means in accordance with the density voltage and the digital data generated from said memory means.
Claim 8
Dependent Claim
32 words
An apparatus according to claim 5, wherein said magnification setting means selects any one of the continuously differring magnifications, and the magnification signal corresponds to a set magnification in a one-to-one correspondence.
Claim 9
Dependent Claim
26 words
An apparatus according to claim 5, wherein said lamp control means comprises a D/A converter for generating an analog voltage signal corresponding to the digital data.
Claim 10
Dependent Claim
34 words
An apparatus according to claim 5, wherein said lamp control means comprises a limiter connected at the output terminal thereof to prevent that the power voltage is over the rating of said lamp means.
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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) | 1989-03-03 | 1989-09-02 | 1990-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-03 | 1993-09-02 | 1994-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-03 | 1997-09-02 | 1998-03-04 | $7700.00 | Window Closed / Lapsed |