Patent EP0385674A2 successfully refreshed from Google Patents.
EP0385674A2
Expired / Lapsed
EP
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Toner image transferring device used in electrophotographic field
Assignee: Fujitsu Ltd
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Filing: 1990-02-23
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Granted: —
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Expires: 2010-02-23
Abstract
Abstract A toner image transferring device is applied to, for example, an electrophotographic printer for electrostatically transferring a charged toner image from a photosensitive drum (10) to a sheet or paper (P), and comprises a transfer charger (16) disposed near the drum (10) to form a clearance therebetween for feeding an electric charge to the sheet or paper through which the sheet or paper is passed, an electric source (38) for supplying an electric energy to the transfer charger to give the sheet or paper an electric charge having a polarity opposite to that of the toner image, and a controller (40) for controlling the electric energy output from the electric source (38) to the transfer charger (11) so that a leading edge of the sheet or paper can be prevented from being excessively charged.
Inventors
- 👤 Masatoshi Kimura
- 👤 Hideaki Iwasaki
- 👤 Sachio Sasaki
- 👤 Kunihiko Sato
- 👤 Masao Konishi
- 👤 Akiyoshi Iwamasa
- 👤 Toshio Tooda
- 👤 Hiroshi Nou
- 👤 Shigenobu Utaka
- 👤 Ryo Kitao
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:05
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/14; G03G15/16; G03G15/163; G03G15/1635; G03G15/1645
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
192 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and means for controlling the electric energy output from said electric source means to said transfer charger means in such a manner that said transfer charger means gives the sheet or paper an amount of electric charge necessary for the transfer of the toner image only when the sheet or paper is completely intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through said clearance therebetween, whereby the leading edge of the sheet or paper is prevented from being excessively charged.
Claim 2
Dependent Claim
192 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and means for controlling the electric energy output from said electric source means to said transfer charger means in such a manner that said transfer charger means gives the sheet or paper an amount of electric charge necessary for the transfer of the toner image only when the sheet or paper is completely intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through said clearance therebetween, whereby the leading edge of the sheet or paper is prevented from being excessively charged.
Claim 3
Dependent Claim
70 words
A toner image transferring device as set forth in claim 1, wherein said toner image carrying body comprises an photosensitive drum which is rotated to bring the toner image to said transfer charger means, and there is provided means for synchronizing the movement of the sheet or paper with the rotation of said photosensitive drum to transfer the toner image to the sheet or paper at a proper position thereon.
Claim 4
Dependent Claim
24 words
A toner image transferring device as set forth in claim 1 or claim 2, wherein said electric source means comprises a direct current source.
Claim 5
Dependent Claim
25 words
A toner image transferring device as set forth in claim 1 or claim 2, wherein said electric source means comprises a direct current voltage source.
Claim 6
Dependent Claim
252 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in the vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while sheet or paper is passed therethrough; electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and means for controlling the electric energy output from said electric source means to said transfer chager means in such a manner that said transfer charger means gives the sheet or paper a first amount of electric charge necessary for the transfer of the toner image only when the sheet or paper is completely intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through the clearance therebetween, and that said transfer charger means gives the sheet or paper a second amount of electric charge less than said first amount of the electric charge when the leading edge of the sheet or paper is intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through said clearance therebetween, whereby the leading edge of the sheet or paper is prevented from being excessively charged.
Claim 7
Dependent Claim
252 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in the vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while sheet or paper is passed therethrough; electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and means for controlling the electric energy output from said electric source means to said transfer chager means in such a manner that said transfer charger means gives the sheet or paper a first amount of electric charge necessary for the transfer of the toner image only when the sheet or paper is completely intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through the clearance therebetween, and that said transfer charger means gives the sheet or paper a second amount of electric charge less than said first amount of the electric charge when the leading edge of the sheet or paper is intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through said clearance therebetween, whereby the leading edge of the sheet or paper is prevented from being excessively charged.
Claim 8
Dependent Claim
70 words
A toner image transferring device as set forth in claim 5, wherein said toner image carrying body comprises an photosensitive drum which is rotated to bring the toner image to said transfer charger means, and a means is provided for synchronizing the movement of the sheet or paper with the rotation of said photosensitive drum to transfer the toner image to the sheet or paper at a proper position thereon.
Claim 9
Dependent Claim
24 words
A toner image transferring device as set forth in claim 5 or claim 6, wherein said electric source means comprises a direct current source.
Claim 10
Dependent Claim
25 words
A toner image transferring device as set forth in claim 5 or claim 6, wherein said electric source means comprises a direct current voltage source.
Claim 11
Dependent Claim
251 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; alternate current charger eliminator means disposed adjacent to an outlet of said clearance from which the sheet or paper is discharged; first electric source means for supplying an electric energy to said transfer charger means to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; second electric source means for supplying an electric energy to said alternate current charger eliminator means to eliminate a first amount of electric charge from the sheet or paper, when leaving from said clearance, to prevent a return of the transferred toner image from the sheet or paper to said toner image carrying body; and means for controlling the electric energy output from said second electric source means to said alternate current charger eliminator means in such a manner that said alternate current charger eliminator means eliminates a second amount of electric charge more than said first amount of electric charge only from the leading edge of the sheet or paper, whereby a separation of the leading edge of the sheet or paper from said toner image carrying body is facilitated.
Claim 12
Dependent Claim
251 words
A toner image transferring device for electrostatically transferring a charged toner image electrostatically held by a toner image carrying body to a sheet or paper, which comprises: transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; alternate current charger eliminator means disposed adjacent to an outlet of said clearance from which the sheet or paper is discharged; first electric source means for supplying an electric energy to said transfer charger means to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; second electric source means for supplying an electric energy to said alternate current charger eliminator means to eliminate a first amount of electric charge from the sheet or paper, when leaving from said clearance, to prevent a return of the transferred toner image from the sheet or paper to said toner image carrying body; and means for controlling the electric energy output from said second electric source means to said alternate current charger eliminator means in such a manner that said alternate current charger eliminator means eliminates a second amount of electric charge more than said first amount of electric charge only from the leading edge of the sheet or paper, whereby a separation of the leading edge of the sheet or paper from said toner image carrying body is facilitated.
Claim 13
Dependent Claim
70 words
A toner image, transferring device as set forth in claim 9, wherein said toner image carrying body comprises an photosensitive drum which is rotated to bring the toner image to said transfer charger means, and a means is provided for synchronizing the movement of the sheet or paper with the rotation of said photosensitive drum to transfer the toner image to the sheet or paper at a proper position thereon.
Claim 14
Dependent Claim
52 words
A toner image transferring device as set forth in claim 9 or claim 10, wherein said means for controlling the electric energy output from said second electric source means to said alternate current charger eliminator means utilizes at least one of a peak-to-peak voltage and an offset voltage as a control parameter.
Claim 15
Dependent Claim
170 words
A toner image transferring device as set forth in any of claims 9 to 11, further comprising: means for controlling the electric energy output from said first electric source means to said transfer charger means in such a manner that said transfer charger means gives the sheet or paper a first amount of electric charge necessary for the transfer of the toner image only when the sheet or paper is completely intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through the clearance therebetween, and that said transfer charger means gives the sheet or paper a second amount of electric charge less than said first amount of the electric charge when the leading edge of the sheet or paper is intervened between said toner image carrying body and said transfer charger means during the passage of the sheet or paper through said clearance therebetween, whereby the leading edge of the sheet or paper is prevented from being excessively charged.
Claim 16
Dependent Claim
70 words
A toner image transferring device as set forth in claim 12, wherein said toner image carrying body comprises an photosensitive drum which is rotated to bring the toner image to said transfer charger means, and a means is provided for synchronizing the movement of the sheet or paper with the rotation of said photosensitive drum to transfer the toner image to the sheet or paper at a proper position thereon.
Claim 17
Dependent Claim
52 words
A toner image transferring device as set forth in claim 9 or claim 10, wherein said means for controlling the electric energy output from said second electric source means to said alternate current charger eliminator means utilizes at least one of a peak-to-peak voltage and an offset voltage as a control parameter.
Claim 18
Dependent Claim
169 words
A printer including: a toner image carrying body having an charged toner image electrostatically held thereby; transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; and electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image, whereby the toner image is transferred from said toner image carrying body to the sheet or paper, and means for controlling the electric energy output from said electric source means to said transfer chager means in such a manner that a leading edge portion of the sheet or paper corredponding to a length measured from an inlet of said clearance to an outlet thereof has a potential less than that of the remaining portion of the sheet or paper.
Claim 19
Dependent Claim
169 words
A printer including: a toner image carrying body having an charged toner image electrostatically held thereby; transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; and electric source means for supplying an electric energy to said transfer charger means so as to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image, whereby the toner image is transferred from said toner image carrying body to the sheet or paper, and means for controlling the electric energy output from said electric source means to said transfer chager means in such a manner that a leading edge portion of the sheet or paper corredponding to a length measured from an inlet of said clearance to an outlet thereof has a potential less than that of the remaining portion of the sheet or paper.
Claim 20
Dependent Claim
244 words
A printer including: a toner image carrying body having an charged toner image electrostatically held thereby; transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; alternate current charger eliminator means disposed adjacent to an outlet of said clearance from which the sheet or paper is discharged; first electric source means for supplying an electric energy to said transfer charger means to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and second electric source means for supplying an electric energy to said alternate current charger eliminator means to eliminate a first amount of electric charge from the sheet or paper, when leaving from said clearance, to prevent a return of the transferred toner image from the sheet or paper to said toner image carrying body, and means for controlling the electric energy output from said first electric source means to said transfer charger means and the electric energy output from said second electric source means to said alternate current charger eliminator in such a manner that a leading edge portion of the sheet or paper corredponding to a length measured from an inle of said clearance to an outlet thereof has a potential less than that of the remaining portion of the sheet or paper.
Claim 21
Dependent Claim
244 words
A printer including: a toner image carrying body having an charged toner image electrostatically held thereby; transfer charger means disposed in a vicinity of said toner image carrying body to form a clearance therebetween for feeding an electric charge to the sheet or paper while the sheet or paper is passed therethrough; alternate current charger eliminator means disposed adjacent to an outlet of said clearance from which the sheet or paper is discharged; first electric source means for supplying an electric energy to said transfer charger means to give the sheet or paper an electric charge having a polarity opposite to that of the charge of the toner image; and second electric source means for supplying an electric energy to said alternate current charger eliminator means to eliminate a first amount of electric charge from the sheet or paper, when leaving from said clearance, to prevent a return of the transferred toner image from the sheet or paper to said toner image carrying body, and means for controlling the electric energy output from said first electric source means to said transfer charger means and the electric energy output from said second electric source means to said alternate current charger eliminator in such a manner that a leading edge portion of the sheet or paper corredponding to a length measured from an inle of said clearance to an outlet thereof has a potential less than that of the remaining portion of the sheet or paper.
Claim 22
Dependent Claim
13 words
A toner image transferring device according to any of claims 1 to 14.
References Cited (Backward Citations)
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