US3914045A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for removing residual image from photoconductive element of electrophotographic copying machine
Assignee: Ricoh Co Ltd
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Filing: 1974-04-24
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Granted: 1975-10-21
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Expires: 1994-04-24
Abstract
Abstract A grounded roller is used to preclean the photoconductive element of a residual image prior to final cleaning by the same magnetic brush which was used in the development step. The density of residual image toner particles resulting from lack of transfer in areas of the electrostatic image on the photoconductive element due to undersized paper or the like is reduced to the density of the toner particles of the normal residual image areas by the grounded roller.
Inventors
- 👤 Ryoichi Namiki
- 👤 Kazunori Matsuo
- 👤 Mutsuo Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:07
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/28; G03G15/30; G03G15/307; G03G21/00; G03G21/0005; G03G21/0047; G03G21/06; G03G2221/00; G03G2221/0005
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
118 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith; a charged member to remove the remainder of the residual image from the photoconductive member through physical contact therewith, and a source of electromotive force to discharge the photoconductive member after performing the transferring step, said photoconductive member being a roller, and in which the grounded member is disposed between the source and the charged member in the direction of rotation of the photoconductive member.
Claim 2
Independent Claim
118 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith; a charged member to remove the remainder of the residual image from the photoconductive member through physical contact therewith, and a source of electromotive force to discharge the photoconductive member after performing the transferring step, said photoconductive member being a roller, and in which the grounded member is disposed between the source and the charged member in the direction of rotation of the photoconductive member.
Claim 3
Dependent Claim
57 words
An appaRatus according to claim 1, in which the charged member is a roller in rolling contact with the photoconductive member, the charged member is a magnetic brush, and the magnetic brush in contact with both the photoconductive member and the grounded member to remove the residual image from both the photoconductive member and the grounded member.
Claim 4
Dependent Claim
37 words
An apparatus according to claim 2, in which the grounded member is formed with a dielectric layer on its surface, and which further comprises a source of electromotive force to charge the surface of the dielectric layer.
Claim 5
Dependent Claim
19 words
An apparatus according to claim 2, in which a wiper is held in sliding contact with the magnetic brush.
Claim 6
Dependent Claim
33 words
An apparatus according to claim 2, in which the grounded member and the magnetic brush are housed in a developing tank into which removed toner particles forming the residual image drop for recycling.
Claim 7
Dependent Claim
32 words
An apparatus according to claim 1, in which the grounded member is a roller in rolling contact with the photoconductive member, and further comprising a wiper in sliding contact with the roller.
Claim 8
Dependent Claim
167 words
An electrophotographic process comprising the steps of: a. charging a rotating photoconductive drum to a first polarity; b. applying a light image to the drum; c. applying toner particles of a second polarity opposite to the first polarity to the drum with a magnetic brush to produce a toner image; d. transferring the toner image utilizing an electric field of the first polarity; e. pressing a grounded member against the drum; f. charging the magnetic brush to the first polarity; and g. pressing the magnetic brush against the drum; whereby toner particles adhere to the drum after step d as a residual toner image, some being charged to the first polarity during step d, a portion of the toner particles being removed by the grounded member during step e so that the densities of the residual toner particles of the first and second polarities are substantially equalized, the remainder of the residual toner particles being removed from the drum by the charged magnetic brush during step g.
Claim 9
Dependent Claim
167 words
An electrophotographic process comprising the steps of: a. charging a rotating photoconductive drum to a first polarity; b. applying a light image to the drum; c. applying toner particles of a second polarity opposite to the first polarity to the drum with a magnetic brush to produce a toner image; d. transferring the toner image utilizing an electric field of the first polarity; e. pressing a grounded member against the drum; f. charging the magnetic brush to the first polarity; and g. pressing the magnetic brush against the drum; whereby toner particles adhere to the drum after step d as a residual toner image, some being charged to the first polarity during step d, a portion of the toner particles being removed by the grounded member during step e so that the densities of the residual toner particles of the first and second polarities are substantially equalized, the remainder of the residual toner particles being removed from the drum by the charged magnetic brush during step g.
Claim 10
Dependent Claim
52 words
A process according to claim 7, in which the magnetic brush is in a fixed location relative to the drum and is in constant frictional contact therewith, and in which step a is performed during one revolution of the drum and step g is performed during a second revolution of the drum.
Claim 11
Dependent Claim
44 words
A process according to claim 7, further comprising the step of: h. applying an electric field of the second polarity to the drum after step e and before step g to convert the residual toner particles of the first polarity to the second polarity.
Claim 12
Independent Claim
131 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith, the grounded member and the photoconductive member being rollers in rolling contact with each other; and a charged member to subsequentially remove the remainder of the residual image from the photoconductive member through physical contact therewith, the charged member being a magnetic brush which is used in the developing step during one revolution of the photoconductive member and to remove the remainder of the residual image from the photoconductive member during a second revolution of the photoconductive member.
Claim 13
Independent Claim
131 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith, the grounded member and the photoconductive member being rollers in rolling contact with each other; and a charged member to subsequentially remove the remainder of the residual image from the photoconductive member through physical contact therewith, the charged member being a magnetic brush which is used in the developing step during one revolution of the photoconductive member and to remove the remainder of the residual image from the photoconductive member during a second revolution of the photoconductive member.
Claim 14
Dependent Claim
23 words
An apparatus according to claim 10, further comprising a source of electromotive force to discharge the photoconductive member after performing the transferring step.
Claim 15
Independent Claim
118 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the appAratus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith; a charged member to remove the remainder of the residual image from the photoconductive memver through physical contact therewith, and a source of electromotive force to discharge the photoconductive member after performing the transferring step, said photoconductive member being a roller, and in which the grounded member is disposed between the charged member and the source in the direction of rotation of the photoconductive member.
Claim 16
Independent Claim
118 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the appAratus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith; a charged member to remove the remainder of the residual image from the photoconductive memver through physical contact therewith, and a source of electromotive force to discharge the photoconductive member after performing the transferring step, said photoconductive member being a roller, and in which the grounded member is disposed between the charged member and the source in the direction of rotation of the photoconductive member.
Claim 17
Dependent Claim
35 words
An apparatus according to claim 12, in which the grounded member is arranged to protrude from a tank in which means are supported in sliding contact with the grounded member to remove toner particles therefrom.
Claim 18
Independent Claim
90 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith and in which the capacitance of the grounded member is greater than that of the photoconductive member; and a charged member to remove the remainder of the residual image from the photoconductive member through physical contact therewith.
Claim 19
Independent Claim
90 words
An apparatus for removing a residual image from a photoconductive member of an electrophotographic copying machine after the photoconductive member has been utilized in the steps of sequentially charging, imaging, developing and transferring, the apparatus comprising: a grounded member to partially remove the residual image from the photoconductive member through physical contact therewith and in which the capacitance of the grounded member is greater than that of the photoconductive member; and a charged member to remove the remainder of the residual image from the photoconductive member through physical contact therewith.
Claim 20
Independent Claim
105 words
A method of removing charged particles from photoconductive member, comprising the steps of: removing a portion of the charged particles having a charge of a first polarity from the photoconductive member through physical contact with a grounded member; converting the first polarity of the charge of the remainder of the portion of the charged particles to a second polarity which is opposite to the first polarity so that the charge of all the particles is of the second polarity; and removing the charge of all the particles of the second polarity through physical contact with a charged member having a charge of the first polarity.
Claim 21
Independent Claim
105 words
A method of removing charged particles from photoconductive member, comprising the steps of: removing a portion of the charged particles having a charge of a first polarity from the photoconductive member through physical contact with a grounded member; converting the first polarity of the charge of the remainder of the portion of the charged particles to a second polarity which is opposite to the first polarity so that the charge of all the particles is of the second polarity; and removing the charge of all the particles of the second polarity through physical contact with a charged member having a charge of the first polarity.
References Cited (Backward Citations)
US3780391A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |