US5457522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charging unit with variable AC voltage
Assignee: Konica Minolta Inc
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Filing: 1994-04-18
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Granted: 1995-10-10
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Expires: 2014-04-18
Abstract
Abstract An image forming apparatus uses a contact-type charger to charge a photoreceptor. The D.C. current supplied to the charger is measured while the output value of the A.C. voltage is changed within a predetermined range, and the output value of the A.C. voltage is set in accordance with the measurement result.
Inventors
- 👤 Satoshi Haneda
- 👤 Kunio Shigeta
- 👤 Sachie Hosogoezawa
- 👤 Hiroyuki Nomori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:04
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0208; G03G15/0241; G03G15/0266; G03G2215/00; G03G2215/02; G03G2215/021; G03G2215/022
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
158 words
An image forming apparatus, comprising: an image forming member on which an electrostatic latent image is formed; a charging member adapted to come in contact with the image forming member, whereby the image forming member is charged to a charged voltage; an electric source to apply an A.C. voltage and a D.C. voltage onto the charging member; first voltage changing means for changing an output value of the A.C. voltage of the electric source; measuring means for measuring a D.C. current supplied to the charging member; threshold value detection means for detecting a threshold value of the D.C. current from measuring results of the D.C. current which are measured by the measuring means while the output value of the A.C. voltage is changed within a predetermined range by the first voltage changing means; and setting means for setting the output value of the A.C. voltage in accordance with the threshold value detected by the threshold value detection means.
Claim 2
Dependent Claim
158 words
An image forming apparatus, comprising: an image forming member on which an electrostatic latent image is formed; a charging member adapted to come in contact with the image forming member, whereby the image forming member is charged to a charged voltage; an electric source to apply an A.C. voltage and a D.C. voltage onto the charging member; first voltage changing means for changing an output value of the A.C. voltage of the electric source; measuring means for measuring a D.C. current supplied to the charging member; threshold value detection means for detecting a threshold value of the D.C. current from measuring results of the D.C. current which are measured by the measuring means while the output value of the A.C. voltage is changed within a predetermined range by the first voltage changing means; and setting means for setting the output value of the A.C. voltage in accordance with the threshold value detected by the threshold value detection means.
Claim 3
Dependent Claim
25 words
The image forming apparatus of claim 1, wherein the charging member comprises a sleeve and a magnetic brush which includes magnetic particles on the sleeve.
Claim 4
Dependent Claim
15 words
The image forming apparatus of claim 1, wherein the charging member comprises a charging roller.
Claim 5
Dependent Claim
33 words
The image forming apparatus of claim 1, wherein the setting means sets the threshold value (V p-p ) th and the output value of the A.C. voltage so as to satisfy: 0.8×(V.sub.p-p).sub.th ≦(V.sub.p-p)≦1.5×(V.sub.p-p).sub.th
Claim 6
Dependent Claim
15 words
The image forming apparatus of claim 1, wherein the D.C. voltage is a constant voltage.
Claim 7
Dependent Claim
23 words
The image forming apparatus of claim 1, further comprising second voltage changing means for changing the charged voltage on the image forming member.
Claim 8
Dependent Claim
158 words
An image forming apparatus, comprising: an image forming member on which an electrostatic latent image is formed; a charging member adapted to come in contact with the image forming member, whereby the image forming member is charged to a charged voltage; an electric source to apply an A.C. voltage and a D.C. voltage onto the charging member; first voltage changing means for changing an output value of the A.C. voltage of the electric source; measuring means for measuring the charged voltage on the image forming member; threshold value detection means for detecting a threshold value of the charged voltage from measuring results of the charged voltage which are measured by the measuring means while the output value of the A.C. voltage is changed within a predetermined range by the first voltage changing means; and setting means for setting the output value of the A.C. voltage in accordance with the threshold value detected by the threshold value detection means.
Claim 9
Dependent Claim
158 words
An image forming apparatus, comprising: an image forming member on which an electrostatic latent image is formed; a charging member adapted to come in contact with the image forming member, whereby the image forming member is charged to a charged voltage; an electric source to apply an A.C. voltage and a D.C. voltage onto the charging member; first voltage changing means for changing an output value of the A.C. voltage of the electric source; measuring means for measuring the charged voltage on the image forming member; threshold value detection means for detecting a threshold value of the charged voltage from measuring results of the charged voltage which are measured by the measuring means while the output value of the A.C. voltage is changed within a predetermined range by the first voltage changing means; and setting means for setting the output value of the A.C. voltage in accordance with the threshold value detected by the threshold value detection means.
Claim 10
Dependent Claim
25 words
The image forming apparatus of claim 7, wherein the charging member comprises a sleeve and a magnetic brush which includes magnetic particles on the sleeve.
Claim 11
Dependent Claim
15 words
The image forming apparatus of claim 7, wherein the charging member comprises a charging roller.
Claim 12
Dependent Claim
33 words
The image forming apparatus of claim 7, wherein the setting means sets the threshold value (V p-p ) th and the output value of the A.C. voltage so as to satisfy: 0.8×(V.sub.p-p).sub.th ≦(V.sub.p-p)≦1.5×(V.sub.p-p).sub.th
Claim 13
Dependent Claim
15 words
The image forming apparatus of claim 7, wherein the D.C. voltage is a constant voltage.
Claim 14
Dependent Claim
23 words
The image forming apparatus of claim 7, further comprising second voltage changing means for changing the charged voltage on the image forming member.
References Cited (Backward Citations)
US4456825A
Cited
US4174903A
Cited
US5164779A
Cited
US4922299A
Cited
US5307122A
Cited
US5351109A
Cited
US5305177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-09 | 1999-04-10 | 1999-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-09 | 2003-04-10 | 2003-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-09 | 2007-04-10 | 2007-10-10 | $7700.00 | Window Closed / Lapsed |