US4806980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamic feedforward process control for electrographic machines
Assignee: Eastman Kodak Co
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Filing: 1986-11-06
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Granted: 1989-02-21
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Expires: 2006-11-06
Abstract
Abstract The specification discloses apparatus by which multiple reproductions can be produced from an original, all reproductions from the same original being of substantially identical quality. An electrographic machine substantially uniformly charges an electrographic recording member to a predetermined initial voltage and imagewise exposes the charged recording member at a nominal exposure level to produce a latent charge image. The initial voltage level and the exposure level are process control parameters of the machine, which also includes a biased electrode for controlling deposition of toner to the latent charge image. Signals are produced and stored having values characteristic of (1) the level of at least one of the parameters and (2) the bias voltage level which are associated with a desired reproduction quality of an original. A comparison signal is produced by taking the signal values of the sensed parameters associated with latent charge images of successive reproductions of an original and comparing them with the stored signal values for the corresponding latent charge images of the same original. The bias voltage level associated with the latent charge image is varied in response to the comparison signal, thereby producing a developed image having substantially the same upright quality as that produced by the stored signal values.
Inventors
- 👤 Fereidoon S. Jamzadeh
- 👤 Michael D. Stoudt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:35
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065; G03G15/50; G03G15/5033; G03G15/5037; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00033; G03G2215/00054
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
203 words
In an electrographic machine for reproducing originals and having (1) means for substantially uniformly charging a recording member, (2) means for imagewise exposing the charged recording member at a nominal exposure level to produce a latent charge image (3) developing means, including an electrode, for depositing toner on the latent charge image, and (4) means for electrically biasing the electrode at a nominal bias voltage level; the improvement comprising: means for producing a signal having a value characteristic of the exposure level associated with a latent charge image; means, operatively coupled to said signal producing means for storing the produced signal value and the nominal bias voltage level which cooperate to produce a first reproduction of an original, said first reproduction having a desired quality; means for producing a comparison signal by comparing the signal value of the sensed exposure level associated with a subsequent latent charge image with the corresponding stored signal value for the corresponding latent charge image of the same original; and means responsive to said comparison signal for varying the bias voltage level associated with the latent charge image to thereby produce a developed image having substantially the same reproduction quality as that produced by the stored signal values.
Claim 2
Dependent Claim
203 words
In an electrographic machine for reproducing originals and having (1) means for substantially uniformly charging a recording member, (2) means for imagewise exposing the charged recording member at a nominal exposure level to produce a latent charge image (3) developing means, including an electrode, for depositing toner on the latent charge image, and (4) means for electrically biasing the electrode at a nominal bias voltage level; the improvement comprising: means for producing a signal having a value characteristic of the exposure level associated with a latent charge image; means, operatively coupled to said signal producing means for storing the produced signal value and the nominal bias voltage level which cooperate to produce a first reproduction of an original, said first reproduction having a desired quality; means for producing a comparison signal by comparing the signal value of the sensed exposure level associated with a subsequent latent charge image with the corresponding stored signal value for the corresponding latent charge image of the same original; and means responsive to said comparison signal for varying the bias voltage level associated with the latent charge image to thereby produce a developed image having substantially the same reproduction quality as that produced by the stored signal values.
Claim 3
Dependent Claim
233 words
In an electrographic machine for reproducing color separations of multi-color originals and having (1) means for substantially uniformly charging an image area of a recording member for each color separation, (2) means for imagewise exposing the charged image areas at a nominal exposure level to produce color separation latent charge images, (3) developing means, including an electrode, for depositing appropriately colored toner on the color separation latent charge image, and (4) means for electrically biasing the electrode at a nominal bias voltage level; the improvement comprising: means for producing a signal having a value characteristic of the exposure level associated with a color separation latent charge image; means, operatively coupled to said signal producing means for storing the produced signal value and the nominal bias voltage level which cooperate to produce a first reproduction of an original, said first reproduction having a desired quality; means for producing a comparison signal by comparing the signal value of the sensed exposure level associated with a subsequent color separation latent charge image of an original with the corresponding stored signal value for the corresponding color separation latent charge image of the same original; and means responsive to said comparison signal for varying the bias voltage level associated with the color separation latent charge image to thereby produce a developed color separation image having substantially the same reproduction quality as that produced by the stored signal values.
Claim 4
Dependent Claim
233 words
In an electrographic machine for reproducing color separations of multi-color originals and having (1) means for substantially uniformly charging an image area of a recording member for each color separation, (2) means for imagewise exposing the charged image areas at a nominal exposure level to produce color separation latent charge images, (3) developing means, including an electrode, for depositing appropriately colored toner on the color separation latent charge image, and (4) means for electrically biasing the electrode at a nominal bias voltage level; the improvement comprising: means for producing a signal having a value characteristic of the exposure level associated with a color separation latent charge image; means, operatively coupled to said signal producing means for storing the produced signal value and the nominal bias voltage level which cooperate to produce a first reproduction of an original, said first reproduction having a desired quality; means for producing a comparison signal by comparing the signal value of the sensed exposure level associated with a subsequent color separation latent charge image of an original with the corresponding stored signal value for the corresponding color separation latent charge image of the same original; and means responsive to said comparison signal for varying the bias voltage level associated with the color separation latent charge image to thereby produce a developed color separation image having substantially the same reproduction quality as that produced by the stored signal values.
References Cited (Backward Citations)
US2956487A
Cited
US3438705A
Cited
US3815988A
Cited
US3877413A
Cited
US3918395A
Cited
US4129375A
Cited
US4128329A
Cited
US4306804A
Cited
US4256401A
Cited
US4284344A
Cited
US4326796A
Cited
WO1981002936A1
Cited
US4310237A
Cited
US4432634A
Cited
US4319544A
Cited
JPS57138668A
Cited
US4408871A
Cited
US4502777A
Cited
US4451137A
Cited
US4502778A
Cited
US4627712A
Cited
US4587536A
Cited
US4477176A
Cited
JPS60173566A
Cited
JPS60178469A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |