US4460270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic exposure control for a photocopying machine
Assignee: Fujifilm Business Innovation Corp
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Filing: 1982-08-03
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Granted: 1984-07-17
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Expires: 2002-08-03
Abstract
Abstract An automatic exposure control method for a photocopying machine is disclosed herein. A sensor is periodically interposed in the light path of the photocopier, which samples the intensity of the light produced by the light producing system. This intensity is compared with a signal representative of the optimum light intensity for the photosensitive drum, and the light source is controlled by inputting the resulting intensity control signal to a voltage regulated light source control device.
Inventors
- 👤 Yuji Watai
- 👤 Toshiyuki Kitamura
- 👤 Yoshiyuki Hirayama
- 👤 Akira Matsuura
- 👤 Hirokazu Yasui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:11
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/043
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
In a photocopying machine in which a light source provides light within an optical path to a photosensitive drum to record an image, the improvement comprising: a light sensor which during a sampling period is inserted into said optical path and senses the intensity of said light in said optical path and produces an output, said light sensor being removed from said optical path after the sampling period, said sampling period recurring periodically; and control means for varying the intensity of said light source as a function of said output signal and maintaining said intensity until the next sampling period.
Claim 2
Dependent Claim
100 words
In a photocopying machine in which a light source provides light within an optical path to a photosensitive drum to record an image, the improvement comprising: a light sensor which during a sampling period is inserted into said optical path and senses the intensity of said light in said optical path and produces an output, said light sensor being removed from said optical path after the sampling period, said sampling period recurring periodically; and control means for varying the intensity of said light source as a function of said output signal and maintaining said intensity until the next sampling period.
Claim 3
Dependent Claim
39 words
The photocopying machine of claim 1, wherein said control means comprises means for comparing said output signal of said light sensor with a signal corresponding to an optimum level of said intensity of said light in said optical path.
Claim 4
Dependent Claim
30 words
The photocopying machine as in claim 2, wherein said optimum level signal is generated as a function of the optimum light intensity for the proper operation of said photosensitive drum.
Claim 5
Dependent Claim
24 words
The photocopying machine of claim 2, wherein said control means further comprises an analog-to-digital converter, a central processing unit, and a voltage-controlled lamp regulator.
Claim 6
Dependent Claim
70 words
An automatic exposure control method for a photocopying machine in which a light source provides exposure light through a light providing system, comprising the steps of: inserting a movable optical detector into the path of light outputted through said light receiving means; sampling said exposure light outputted through said light providing system with said optical detector; and altering said light source automatically to maintain an optimum level of said exposure.
Claim 7
Dependent Claim
70 words
An automatic exposure control method for a photocopying machine in which a light source provides exposure light through a light providing system, comprising the steps of: inserting a movable optical detector into the path of light outputted through said light receiving means; sampling said exposure light outputted through said light providing system with said optical detector; and altering said light source automatically to maintain an optimum level of said exposure.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-17 | 1988-01-16 | 1988-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-17 | 1992-01-16 | 1992-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-17 | 1996-01-16 | 1996-07-17 | $7700.00 | Window Closed / Lapsed |