US4480911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing apparatus and a developing method of an electrostatic image
Assignee: Konica Minolta Inc
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Filing: 1982-06-22
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Granted: 1984-11-06
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Expires: 2002-06-22
Abstract
Abstract In an electrostatic copying apparatus of the type in which a magnetic toner is applied to an image holder such as a drum from a developing roller which in turn receives the toner from a supply roller, a source of relative positive and negative voltages is alternately applied to the developing roller. This produces electric fields which move the toner from the supply roller to the developing roller and then to the image holder with the desired relative polarities.
Inventors
- 👤 Masahiko Itaya
- 👤 Satoshi Haneda
- 👤 Makoto Tomono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:35
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/065; G03G15/08; G03G15/0806; G03G2215/00; G03G2215/06; G03G2215/0602; G03G2215/0604; G03G2215/0614; G03G2215/0619; G03G2215/0634; G03G2215/0636
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
In an electrostatic copying apparatus of the type in which a magnetic developer is applied to a movable electrostatic image holder from a movable developing member, which in turn receives magnetic developer from a movable supply member, the improvement comprising a power source, and means alternately supplying said developing member from said power source with voltages of effectively opposite polarity, whereby said magnetic developer is attracted from said supply member to said developing member at one time, and from said developing member to said image holder at another time to produce a latent magnetic developer image upon the latter.
Claim 2
Dependent Claim
99 words
In an electrostatic copying apparatus of the type in which a magnetic developer is applied to a movable electrostatic image holder from a movable developing member, which in turn receives magnetic developer from a movable supply member, the improvement comprising a power source, and means alternately supplying said developing member from said power source with voltages of effectively opposite polarity, whereby said magnetic developer is attracted from said supply member to said developing member at one time, and from said developing member to said image holder at another time to produce a latent magnetic developer image upon the latter.
Claim 3
Dependent Claim
46 words
In an electrostatic copying apparatus, the improvement according to claim 1, in which the voltage supplied to said developing member from said supply means is such as to change the charge of said developer on said developing member opposite to the charge on said image holder.
Claim 4
Dependent Claim
38 words
In an electrostatic copying apparatus, the improvement according to claim 1, in which said voltage supply means is a pulse source producing a pulse wave forming an electric field intermittently transferring the magnetic developer to the image holder.
Claim 5
Dependent Claim
19 words
In an electrostatic copying apparatus, the improvement according to claim 1, in combination with means grounding said supply member.
Claim 6
Dependent Claim
19 words
In an electrostatic copying apparatus, the improvement according to claim 1, in which said developing member is a roller.
Claim 7
Dependent Claim
19 words
In an electrostatic copying apparatus, the improvement according to claim 2, in which said developing member is a roller.
Claim 8
Dependent Claim
21 words
In an electrostatic copying apparatus, the improvement according to claim 1, in which said magnetic developer is a single component toner.
Claim 9
Dependent Claim
35 words
In an electrostatic copying apparatus, the improvement according to claim 3, in which said pulse source produces relatively positive and negative pulses of which the positive pulses have a larger duration than the negative pulses.
Claim 10
Dependent Claim
31 words
In an electrostatic copying apparatus, the improvement according to claim 8, in which the duration of the negative pulses is not greater than 0.4 times the duration of the positive pulses.
Claim 11
Dependent Claim
22 words
In an electrostatic copying apparatus, the improvement according to claim 1, in which the developing member and the supply member are rollers.
Claim 12
Dependent Claim
75 words
In an electrostatic copying apparatus, the improvement according to claim 10, in which the speeds of the developing roller, the movable image holder and the supply roller satisfy the equation: Ls≧Ld≧Lm in which Ls is the linear speed of the peripheral surface of the supply roller, Ld is the linear speed of the peripheral surface of the developing roller, and Lm is the linear speed of movement of the latent image on the image holder.
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) | 1987-11-06 | 1988-05-07 | 1988-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-06 | 1992-05-07 | 1992-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-06 | 1996-05-07 | 1996-11-06 | $7700.00 | Window Closed / Lapsed |