Patent US4995219A successfully refreshed from Google Patents.
Patent US5719613A successfully refreshed from Google Patents.
US5719613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for forming an image with use of electrophotographic process
Assignee: Minolta Co Ltd
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Filing: 1995-06-01
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Granted: 1998-02-17
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Expires: 2015-06-01
Abstract
Abstract In a apparatus for forming a digital image with use of electrophotographic process wherein the gradation is expressed by changing the laser intensity according to image information, at least one of the surface electric potential V O of photoconductor and the development bias electric voltage V B is controlled, and the laser intensity is controlled for gradation correction to compensate a change in gradation due to the control of V O and V B . A ratio of variable differences of potential in the apparatus, (V B -V I )/(V O -V I ), is kept constant to control the gamma characteristic in the apparatus.
Inventors
- 👤 Kazuyuki Fukui
- 👤 Takanobu Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:14
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/407; G; G03; G03G; G03G15/00; G03G15/04; G03G15/04036; G03G15/04045; G03G15/04072; G03G15/22; G03G15/32; G03G15/326; H04N1/23; H04N1/29; H04N1/295; G03G15/043
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
141 words
An apparatus for forming an image according to digital data, comprising: a photoconductor; sensitizing means for sensitizing said photoconductor at a sensitizing electric potential; exposure means for exposing said sensitized photoconductor to form an electrostatic latent image; development means for developing the electrostatic latent image; bias means for supplying a bias electric voltage to said development means, which bias electric voltage being given to toners; and control means for controlling a ratio of a variable difference between the sensitizing electric potential and an electric potential of the electrostatic latent image exposed at a maximum quantity of light by said exposure means with respect to a variable difference between the development bias electric potential supplied by said bias means and the electric potential of the electrostatic latent image exposed at the maximum quantity of light so that the ratio is kept constant.
Claim 2
Independent Claim
141 words
An apparatus for forming an image according to digital data, comprising: a photoconductor; sensitizing means for sensitizing said photoconductor at a sensitizing electric potential; exposure means for exposing said sensitized photoconductor to form an electrostatic latent image; development means for developing the electrostatic latent image; bias means for supplying a bias electric voltage to said development means, which bias electric voltage being given to toners; and control means for controlling a ratio of a variable difference between the sensitizing electric potential and an electric potential of the electrostatic latent image exposed at a maximum quantity of light by said exposure means with respect to a variable difference between the development bias electric potential supplied by said bias means and the electric potential of the electrostatic latent image exposed at the maximum quantity of light so that the ratio is kept constant.
Claim 3
Dependent Claim
28 words
An apparatus according to claim 1, wherein said control means controls the sensitizing means so that the sensitizing electric potential has a value to keep the ratio constant.
Claim 4
Dependent Claim
25 words
An apparatus according to claim 2, further comprising detection means for detecting the electric potential of an electrostatic latent image formed by said exposure means.
Claim 5
Dependent Claim
20 words
An apparatus according to claim 2, further comprising input means for inputting the ratio which has to be kept constant.
Claim 6
Dependent Claim
24 words
An apparatus according to claim 1 wherein said exposure means exposes said photoconductor at a quantity of light based on the digital image data.
Claim 7
Dependent Claim
29 words
An apparatus according to claim 1, wherein said control means controls said bias means so that the development bias electric voltage has a value to keep the ratio constant.
Claim 8
Dependent Claim
25 words
An apparatus according to claim 6, further comprising detection means for detecting the electric potential of an electrostatic latent image formed by said exposure means.
Claim 9
Dependent Claim
20 words
An apparatus according to claim 6, further comprising input means for inputting the ratio which has to be kept constant.
Claim 10
Dependent Claim
24 words
An apparatus according to claim 6, wherein said exposure means exposes said photoconductor at a quantity of light determined by the digital image data.
Claim 11
Dependent Claim
37 words
An apparatus according to claim 1, wherein said control means controls said sensitizing means and said bias means so that the sensitizing electric potential and the development bias electric voltage have values to satisfy the ratio constant.
Claim 12
Dependent Claim
25 words
An apparatus according to claim 10, further comprising detection means for detecting the electric potential of an electrostatic latent image formed by said exposure means.
Claim 13
Dependent Claim
20 words
An apparatus according to claim 10, further comprising input means for inputting the ratio which has to be kept constant.
Claim 14
Dependent Claim
24 words
An apparatus according to claim 10, wherein said exposure means exposes said photoconductor at a quantity of light based on the digital image data.
Claim 15
Independent Claim
152 words
An apparatus for forming an image according to digital data, comprising: a photoconductor; sensitizing means for sensitizing said photoconductor at a sensitizing electric potential; exposure means for exposing said photoconductor to be sensitized beforehand by said sensitizing means to form an electrostatic latent image; development means for developing the electrostatic latent image; supply means for supplying a bias electric voltage to said development means, which bias electric voltage being given to toners; selection means for selecting a value; and control means for controlling a ratio of a difference voltage between the sensitizing electric potential and an electric potential of the electrostatic latent image exposed at the maximum quantity of light by said exposure means with respect to a difference voltage between the development bias electric potential supplied by said supply means and the electric potential of the electrostatic latent image so that the ratio has the value selected by said selection means.
Claim 16
Independent Claim
152 words
An apparatus for forming an image according to digital data, comprising: a photoconductor; sensitizing means for sensitizing said photoconductor at a sensitizing electric potential; exposure means for exposing said photoconductor to be sensitized beforehand by said sensitizing means to form an electrostatic latent image; development means for developing the electrostatic latent image; supply means for supplying a bias electric voltage to said development means, which bias electric voltage being given to toners; selection means for selecting a value; and control means for controlling a ratio of a difference voltage between the sensitizing electric potential and an electric potential of the electrostatic latent image exposed at the maximum quantity of light by said exposure means with respect to a difference voltage between the development bias electric potential supplied by said supply means and the electric potential of the electrostatic latent image so that the ratio has the value selected by said selection means.
Claim 17
Dependent Claim
18 words
An apparatus according to claim 14, wherein said selection means select a value among a plurality of values.
Claim 18
Dependent Claim
27 words
An apparatus according to claim 15, wherein the plurality of values selected by said selection means represent a density of an image developed by said development 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) | 2001-02-16 | 2001-08-18 | 2002-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-16 | 2005-08-18 | 2006-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-16 | 2009-08-18 | 2010-02-17 | $7700.00 | Window Closed / Lapsed |