Patent EP0344930A1 successfully refreshed from Google Patents.
EP0344930A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrophotographic printer with developing unit employing two-component toning system
Assignee: Oki Electric Industry Co Ltd
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Filing: 1989-05-09
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Granted: —
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Expires: 2009-05-09
Abstract
Abstract A printer has a photoconductor (103), a charger (111) an exposure unit (115) a container (125) containing toner particles (119) and carrier particles (121), a developing unit (117) that feeds the toner particles onto the photoconductor surface, a bias generator (140) and a bias generator controller (150). The charger (111) induces an electric charge on the charged area of the photoconductor surface so as to establish a first electric potential (Vs) on the photoconductor surface (103a) which retains the electric charge for significant period of time. The exposure unit (115) forms a latent image within the charged area. The bias generator (140) provides the developing unit with a second electrid potential (Vdb) so as to produce a potential difference (Vdb - Vs) between the developing unit (17) and photoconductor surface. Thereby the toner particles are significantly attracted to the latent image on the photoconductor surface. The developing unit (117) thereby applies the toner particles from the container to the photoconductor surface. If the charger stops inducing the potential (Vs) due to a malfunction of the printer, the bias generator controller (150) causes the bias generator (140) to provide the developing unit (117) with the same electric potential (Vdb) for a predetermined period of time, until either the carrier particles are not significantly attracted to the electric charge or the charged area of the photoconductor passes away from the position adjacent to the developing unit (117) after the charger stops inducing the potential (Vs). When the printer is actuated by a switch (109), the bias generator controller further causes the bias generator (140) to provide the developing unit (117) with the second electric potential (Vdb) prior to the charged area being transported into the position adjacent to said developing unit in response to operation of the switch to actuate the printer.
Inventors
- 👤 Koji C/O Oki Electric Industry Co. Ltd. Nitta
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:22
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0907; G03G15/065
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
178 words
An apparatus comprising: a photoconductor (103) having a photoconductor surface; means (111) for inducing electric charges on a charged area of said photoconductor surface so as to establish a first electric potential (Vs); means (115) for forming a latent image within the charged area; means (125 )for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means(127) for applying the toner particles from said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means (140) for providing said applying means with a second electric potential (Vdb) whereby the toner particles are significantly attracted to the latent image on the said photoconductor surface; and characterised by means (150) for controlling said second electric potential providing means (140) so that said second electric potential providing means continues to provide the second potential for sufficient time to prevent the carrier particles from adhering to the photoconductor surface until the carrier particles are not significantly attracted to the electric charges after said inducing means stops inducing the electric charge.
Claim 2
Independent Claim
178 words
An apparatus comprising: a photoconductor (103) having a photoconductor surface; means (111) for inducing electric charges on a charged area of said photoconductor surface so as to establish a first electric potential (Vs); means (115) for forming a latent image within the charged area; means (125 )for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means(127) for applying the toner particles from said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means (140) for providing said applying means with a second electric potential (Vdb) whereby the toner particles are significantly attracted to the latent image on the said photoconductor surface; and characterised by means (150) for controlling said second electric potential providing means (140) so that said second electric potential providing means continues to provide the second potential for sufficient time to prevent the carrier particles from adhering to the photoconductor surface until the carrier particles are not significantly attracted to the electric charges after said inducing means stops inducing the electric charge.
Claim 3
Dependent Claim
85 words
An apparatus according to claim 1, wherein said controlling means include means for providing said second electric potential providing means with a first signal, said second electric potential providing means stopping providing the second electric potential upon receiving the first signal; and wherein said controlling means further include means for generating a second signal at the time of a malfunction of the apparatus, said first signal providing means preventing from providing the first signal during a second period of time after receiving the second signal.
Claim 4
Dependent Claim
59 words
An apparatus according to claim 2, wherein said first signal providing means has a capacitor and a resistor so as to be set a predetermined RC time constant therein, the predetermined RC time constant setting the second period for preventing from providing the first signal, the second period being set so as to be terminated after the first period.
Claim 5
Independent Claim
217 words
An apparatus comprising: a photoconductor having photoconductor surface; means for inducing an electric charge on a charged area of said photoconductor surface so as to establish a first electric potential, said photoconductor surface retaining the electric charge on the charged area thereof for a first period of time; means for forming a latent image within the charged area; means for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means for applying the toner particles from said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means for transporting the charged area of said photoconductor surface from a position adjacent to said inducing means to a position adjacent to said applying means; means for providing said applying means with a second electric potential whereby the toner particles are significantly attracted to the latent image within the charged area of said photoconductor surface; means for controlling said second electric potential providing means so that said second electric potential providing means successively provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface until the charged area of said photoconductor surface passes away from the position adjacent to said applying means after said inducing means stop inducing the electric charge.
Claim 6
Independent Claim
217 words
An apparatus comprising: a photoconductor having photoconductor surface; means for inducing an electric charge on a charged area of said photoconductor surface so as to establish a first electric potential, said photoconductor surface retaining the electric charge on the charged area thereof for a first period of time; means for forming a latent image within the charged area; means for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means for applying the toner particles from said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means for transporting the charged area of said photoconductor surface from a position adjacent to said inducing means to a position adjacent to said applying means; means for providing said applying means with a second electric potential whereby the toner particles are significantly attracted to the latent image within the charged area of said photoconductor surface; means for controlling said second electric potential providing means so that said second electric potential providing means successively provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface until the charged area of said photoconductor surface passes away from the position adjacent to said applying means after said inducing means stop inducing the electric charge.
Claim 7
Dependent Claim
85 words
An apparatus according to claim 4, wherein said controlling means include means for providing said second electric potential providing means with a first signal, said second electric potential providing means stopping providing the second electric potential upon receiving the first signal, and wherein said controlling means further include means for generating a second signal at the time of a malfunction of the apparatus, said first signal providing means preventing from providing the first signal during a second period of time after receiving the second signal.
Claim 8
Dependent Claim
89 words
An apparatus according to claim 5, wherein said first signal providing means has a capacitor and a resistor so as to be set a predetermined RC time constant therein, the predetermined RC time constant setting the second period for preventing from providing the first signal, the second period being set so as to be terminated after the charged area of said photoconductor surface passes away from the position adjacent to said applying means after said inducing means stop inducing the electric charge due to a malfunction of the apparatus.
Claim 9
Independent Claim
237 words
An apparatus comprising: means for actuating the apparatus; a photoconductor having a photoconductor surface; means for inducing an electric charge on a charged area of said photoconductor surface so as to establish a first electric potential, said photoconductor surface retaining the electric charge on the charged area thereof for a first period of time; means for forming a latent image within the charged area; means for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means for applying the toner particles form said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means for transporting the charged area of said photoconductor surface from a position adjacent to said inducing means to a position adjacent to said applying means; means for providing said applying means with a second electric potential when the charged area of said photoconductor surface is transported into the position adjacent to said applying means, whereby the toner particles are significantly attracted to the latent image on said photoconductor surface; means for controlling said second electric potential providing means so that said second electric potential providing means preliminary provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface before the charged area of said photoconductor surface is transported into the position adjacent to said applying means after the apparatus is actuated by said actuating means.
Claim 10
Independent Claim
237 words
An apparatus comprising: means for actuating the apparatus; a photoconductor having a photoconductor surface; means for inducing an electric charge on a charged area of said photoconductor surface so as to establish a first electric potential, said photoconductor surface retaining the electric charge on the charged area thereof for a first period of time; means for forming a latent image within the charged area; means for storing toner particles and carrier particles, the toner particles being mixed with the carrier particles; means for applying the toner particles form said storing means to said photoconductor surface, and for returning the carrier particles to said storing means; means for transporting the charged area of said photoconductor surface from a position adjacent to said inducing means to a position adjacent to said applying means; means for providing said applying means with a second electric potential when the charged area of said photoconductor surface is transported into the position adjacent to said applying means, whereby the toner particles are significantly attracted to the latent image on said photoconductor surface; means for controlling said second electric potential providing means so that said second electric potential providing means preliminary provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface before the charged area of said photoconductor surface is transported into the position adjacent to said applying means after the apparatus is actuated by said actuating means.
Claim 11
Dependent Claim
83 words
An apparatus according to claim 7, wherein said controlling means include means for providing said second electric potential proaviding meas with a first signal, said second electric potential providing means stopping providing the second electric potential upon receiving the first signal, and wherein said controlling means further include means for generating a second sijnal when said actuating means actuate the apparatus, said first signal providing means preventing from providing the first signal during a second period of time after receiving the second signal.
Claim 12
Dependent Claim
80 words
An apparatus according to claim 8, wherein said first signal providing means has a capacitor and a resistor so as to be set a predetermined RC time constant therein, the predetermined RC time constant setting the second period for preventing from providing the first signal, the second period being set so as to be terminated before the charged area of said photoconductor surface is transported into the position adjacent to said applying means after said actuating means actuate the apparatus.
Claim 13
Dependent Claim
64 words
An apparatus according to claim 7, wherein said controlling means further have said second electric potential providing means successively provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface until the carrier particles are not signicantly attracted to the electric charged after said inducing means stop inducing the electric charge due to a malfunction of the apparatus.
Claim 14
Dependent Claim
48 words
An apparatus according to claim 10, wherein said second signal generating means further generates the second signal at the time of a malfunction of the apparatus, said first signal providing means preventing from providing the first signal during a third period of time after receiving the second signal.
Claim 15
Dependent Claim
58 words
An apparatus according to claim 11, wherein said first signal providing means has a capacitor and a resistor so as to be set a predetermined RC time constant therein, the predetermined RC time constant setting the third period for preventing providing the first signal, the third period being so as to be terminated set after the first period.
Claim 16
Dependent Claim
70 words
An apparatus according to claim 7, wherein said controlling means further have said second electric potential providing means successively provide the second potential so as to prevent the carrier particles from adhering to said photoconductor surface until the charged area of said photoconductor surface passes away from the position adjacent to said applying means after said inducing means stop inducing the electric charge due to a malfuntion of the apparatus.
Claim 17
Dependent Claim
48 words
An apparatus according to claim 13, wherein said second signal generating means further generates the second signal at the time of a malfunction of the apparatus, said first signal providing means preventing from providing the first signal during a fourth period of time after receiving the second singal.
Claim 18
Dependent Claim
88 words
An apparatus according to claim 14, wherein said first signal providing means has a capacitor and a resistor so as to be set a predetermined RC time constant therein, the predetermined RC time constant setting the fourth period for preventing previding the first signal, the fourth period being set so as to be terminated after the charged area of said photoconductor surface passes away from the position adjacent to said applying means after said inducing means stop inducing the electric charge due to a malfunction of the apparatus.
Claim 19
Independent Claim
135 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of; inducing an electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge for significant period of time; forming a latent image within the charged area; applying the toner particles to said photoconductor surface; providing said step of applying with a second electric potential whereby the toner particles are significantly attracted to the latent image on the photoconductor surface; and controlling said step of providing so as to successively provide the second potential until the carrier particles are not significantly attracted to the electric charged after said step of inducing has stopped inducing the electric charge.
Claim 20
Independent Claim
135 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of; inducing an electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge for significant period of time; forming a latent image within the charged area; applying the toner particles to said photoconductor surface; providing said step of applying with a second electric potential whereby the toner particles are significantly attracted to the latent image on the photoconductor surface; and controlling said step of providing so as to successively provide the second potential until the carrier particles are not significantly attracted to the electric charged after said step of inducing has stopped inducing the electric charge.
Claim 21
Independent Claim
156 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of: inducing an electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge on the charged area thereof for significant period of time; forming a latent image within the charged area; applying the toner particles to the photoconductor surface; transporting the charged area of said photoconductor surface form said step of inducing to said step of applying; providing said step of applying with a second electric potnetial whereby the toner particles are significantly attracted to the latent image on tha charged area; controlling said step of providing so as to successively provide the second potential until the charged area passes away from said step of applying after said step of inducing has stopped inducing the electric charge.
Claim 22
Independent Claim
156 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of: inducing an electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge on the charged area thereof for significant period of time; forming a latent image within the charged area; applying the toner particles to the photoconductor surface; transporting the charged area of said photoconductor surface form said step of inducing to said step of applying; providing said step of applying with a second electric potnetial whereby the toner particles are significantly attracted to the latent image on tha charged area; controlling said step of providing so as to successively provide the second potential until the charged area passes away from said step of applying after said step of inducing has stopped inducing the electric charge.
Claim 23
Independent Claim
177 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of; commencing the method; inducing a electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge on the charged are thereof for significant periods of time; forming a latent image within the charged area; applying the toner particles to said photoconductor surface; transporting the charged area of said photoconductor surface from said step of inducing to said step of applying; providing said step of applying with a second electric potential when the charged area of said photoconductor surface is transported into said step of applying whereby the toner particles are significantly attracted to the latent image; controlling said step of providing so as to preliminary provide said step of applying with the second potential before the charged area of said photoconductor surface is transported into the position adjacent to said step of applying after said step of commencing.
Claim 24
Independent Claim
177 words
A method for forming toner particles on a photoconductor surface of a photoconductor, the toner particles being mixed with carrier particles, comprising the steps of; commencing the method; inducing a electric charge on a charged area of the photoconductor surface so as to establish a first electric potential, the photoconductor surface retaining the electric charge on the charged are thereof for significant periods of time; forming a latent image within the charged area; applying the toner particles to said photoconductor surface; transporting the charged area of said photoconductor surface from said step of inducing to said step of applying; providing said step of applying with a second electric potential when the charged area of said photoconductor surface is transported into said step of applying whereby the toner particles are significantly attracted to the latent image; controlling said step of providing so as to preliminary provide said step of applying with the second potential before the charged area of said photoconductor surface is transported into the position adjacent to said step of applying after said step of commencing.
Claim 25
Dependent Claim
56 words
A method according to claim 18, wherein said step of controlling further includes a step of controlling said step of providing so as to successively provide the second potential until the carrier particles are not significantly attracted to the electric charged after said step of inducing has stopped inducing the electric charge dur to a malfunction.
Claim 26
Dependent Claim
55 words
A method according to claim 20, wherein said step of controlling further includes a step of controlling said step of providing so as to successively provide the second potential until the charged area passes away from said step of applying after said step of inducing has stopped inducing the electric charge due to a malfunction.
Claim 27
Dependent Claim
130 words
Electrophotographic apparatus comprising: a surface (103) to receive an electrostatic latent image; means (111) for electrostatically charging the surface; means (115) for forming an electrostatic latent image in the charged surface (103); developing means (117) for developing said image with toner; bias generator means (140) for applying a bias potential to said developing means to establish a potential difference between the charged surface (103) and the developing means for permitting transfer of the toner to said latent image; and characterised by control means (150) so arranged that in the event of the charging means (111) ceasing operation and leaving a residual charge on said surface (103) a bias potential is applied to said developing means to inhibit preferential attraction of the toner to said surface by the residual charge thereon.
Claim 28
Dependent Claim
130 words
Electrophotographic apparatus comprising: a surface (103) to receive an electrostatic latent image; means (111) for electrostatically charging the surface; means (115) for forming an electrostatic latent image in the charged surface (103); developing means (117) for developing said image with toner; bias generator means (140) for applying a bias potential to said developing means to establish a potential difference between the charged surface (103) and the developing means for permitting transfer of the toner to said latent image; and characterised by control means (150) so arranged that in the event of the charging means (111) ceasing operation and leaving a residual charge on said surface (103) a bias potential is applied to said developing means to inhibit preferential attraction of the toner to said surface by the residual charge thereon.
References Cited (Backward Citations)
US4286866A
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