US5374949A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming apparatus
Assignee: Kyocera Corp
•
Filing: 1993-07-26
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Granted: 1994-12-20
•
Expires: 2013-07-26
Abstract
Abstract An apparatus and method for printing directly on plain paper, utilizing an arrayed control grid having a plurality of toner slots. An alternating electrostatic field in a space between a toner carrier and a backing electrode gives toner a vibrational motion to prevent a toner clog at the slot. The field is also formed to repel the clogged toner back to the toner carrier, or to fall it down on a paper on the backing electrode during no print is performed to clean the control grid. A constitution of conductive and dielectric materials for the members assures to form the field.
Inventors
- 👤 Takasumi Wada
- 👤 Masayuki Tone
- 👤 Hidemasa Aiba
- 👤 Keiji Itsukushima
- 👤 Ove Larson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:56
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/41; B41J2/415; B41J2/4155; G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G15/346
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
177 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: an electric signal source connected across the toner carrier and the backing electrode to apply an electric signal between the toner carrier and the backing electrode for forming an electrostatic field in the space from the toner carrier to the backing electrode to transfer the toner to the recording sheet, said electrostatic field periodically alternating in polarity between positive and negative states.
Claim 2
Dependent Claim
177 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: an electric signal source connected across the toner carrier and the backing electrode to apply an electric signal between the toner carrier and the backing electrode for forming an electrostatic field in the space from the toner carrier to the backing electrode to transfer the toner to the recording sheet, said electrostatic field periodically alternating in polarity between positive and negative states.
Claim 3
Dependent Claim
145 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically in response to open and close control potentials, respectively, said apparatus operable to selectively open the toner slots in response to an open control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for fluctuating the amplitude of said close control potential, wherein the toner stuck on the toner passage electromagnetically vibrates.
Claim 4
Dependent Claim
145 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically in response to open and close control potentials, respectively, said apparatus operable to selectively open the toner slots in response to an open control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for fluctuating the amplitude of said close control potential, wherein the toner stuck on the toner passage electromagnetically vibrates.
Claim 5
Dependent Claim
23 words
Apparatus as claimed in claim 2, wherein the control potential is a series of voltage pulses composed of a plurality of clock pulses.
Claim 6
Dependent Claim
154 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: forming an electrostatic field merely in an interspace between the means for passing toner when no image is being formed, wherein toner stuck on the means for toner passage is transferred to the recording sheet adjacent the backing electrode.
Claim 7
Dependent Claim
154 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: forming an electrostatic field merely in an interspace between the means for passing toner when no image is being formed, wherein toner stuck on the means for toner passage is transferred to the recording sheet adjacent the backing electrode.
Claim 8
Dependent Claim
56 words
Apparatus as claimed in claim 4, wherein the means for forming the electrostatic field merely in the interspace between the means for passing toner and the backing electrode when no image comprises an insulating layer provided on the toner carrier and means for polarizing the toner carrier with the same polarity as that of the toner.
Claim 9
Dependent Claim
142 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slot, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: a layer for preventing electrification formed inside the toner slots; wherein the layer for preventing electrification is formed of insulating material mixed with a surface active agent.
Claim 10
Dependent Claim
142 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slot, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: a layer for preventing electrification formed inside the toner slots; wherein the layer for preventing electrification is formed of insulating material mixed with a surface active agent.
Claim 11
Dependent Claim
143 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement wherein: the toner carrier is made with an electric conductive material, and an insulating material is provided on the surface of toner carrier facing the means for passing toner.
Claim 12
Dependent Claim
143 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement wherein: the toner carrier is made with an electric conductive material, and an insulating material is provided on the surface of toner carrier facing the means for passing toner.
Claim 13
Dependent Claim
152 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: the toner including a magnetic material, a plurality of magnets being circumferentially disposed inside the toner carrier to bring the toner into ears thereon, said toner ear extending to the surface of the means for passing toner.
Claim 14
Dependent Claim
152 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: the toner including a magnetic material, a plurality of magnets being circumferentially disposed inside the toner carrier to bring the toner into ears thereon, said toner ear extending to the surface of the means for passing toner.
Claim 15
Dependent Claim
160 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: providing a pulsed voltage signal for the control potential applied to the means for passing toner, and controlling the duty ratio and pulse length of said pulsed voltage signal according to the variation of the distance between the means for toner passage and other members.
Claim 16
Dependent Claim
160 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: providing a pulsed voltage signal for the control potential applied to the means for passing toner, and controlling the duty ratio and pulse length of said pulsed voltage signal according to the variation of the distance between the means for toner passage and other members.
Claim 17
Dependent Claim
180 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for applying a charge having a polarity opposite to that of the charge of the backing electrode, said means for applying the charge located in the same plane of the means for passing toner, within the area where no print is developed, wherein the charge of reverse polarity is applied to the means for applying charge during the occasion when no print is developed.
Claim 18
Dependent Claim
180 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for applying a charge having a polarity opposite to that of the charge of the backing electrode, said means for applying the charge located in the same plane of the means for passing toner, within the area where no print is developed, wherein the charge of reverse polarity is applied to the means for applying charge during the occasion when no print is developed.
Claim 19
Dependent Claim
21 words
Apparatus as claimed in claim 10, wherein the potential level of the reverse polarity is effectable to close the toner slot.
Claim 20
Dependent Claim
186 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for applying a charge having a polarity which is the same as that of the charge of toner on the toner carrier, said means for applying the charge located in the same plane of the means for passing toner within the area where no print is developed, wherein the charge of the same polarity is applied to the means for applying charge during the occasion when no print is developed.
Claim 21
Dependent Claim
186 words
In an apparatus for forming an image, having a toner carrier with a toner layer thereon, a backing electrode adjacent which a recording sheet is arrangeable, said backing electrode spaced from and facing the toner carrier, and means for selectively passing toner disposed between the toner carrier and the backing electrode, said means defining a plurality of toner slots, said toner slots operable to selectively open and close electromagnetically, said apparatus operable to selectively open the toner slots in response to a control potential corresponding to image information applied to the means for passing toner and to transfer toner from the toner carrier to the recording sheet through the toner slots, wherein the improvement comprises: means for applying a charge having a polarity which is the same as that of the charge of toner on the toner carrier, said means for applying the charge located in the same plane of the means for passing toner within the area where no print is developed, wherein the charge of the same polarity is applied to the means for applying charge during the occasion when no print is developed.
Claim 22
Dependent Claim
108 words
In an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, and a control grid disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode, wherein the improvement comprises: an electric signal source connected across the toner carrier and the backing electrode to apply an alternating electric signal between the toner carrier and the backing electrode for forming an electrostatic field in the space from the toner carrier to the backing electrode, said electrostatic field periodically alternating in polarity between positive and negative states.
Claim 23
Dependent Claim
108 words
In an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, and a control grid disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode, wherein the improvement comprises: an electric signal source connected across the toner carrier and the backing electrode to apply an alternating electric signal between the toner carrier and the backing electrode for forming an electrostatic field in the space from the toner carrier to the backing electrode, said electrostatic field periodically alternating in polarity between positive and negative states.
Claim 24
Dependent Claim
138 words
In an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, an electric field for drawing toner from the toner layer toward the backing electrode, a control grid having a toner passage disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode and means for applying a close control signal to the control grid for controlling the grid to inhibit passing toner through the toner passage from the toner layer toward the backing electrode, wherein at least some of the toner inherently collects on the control grid around the toner passage, the improvement comprises: means for fluctuating the amplitude of said close control potential, wherein the toner collected on the control grid electromagnetically vibrates.
Claim 25
Dependent Claim
138 words
In an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, an electric field for drawing toner from the toner layer toward the backing electrode, a control grid having a toner passage disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode and means for applying a close control signal to the control grid for controlling the grid to inhibit passing toner through the toner passage from the toner layer toward the backing electrode, wherein at least some of the toner inherently collects on the control grid around the toner passage, the improvement comprises: means for fluctuating the amplitude of said close control potential, wherein the toner collected on the control grid electromagnetically vibrates.
Claim 26
Dependent Claim
16 words
Apparatus as claimed in claim 14, wherein the control signal comprises a series of voltage pulses.
Claim 27
Dependent Claim
74 words
An image forming apparatus comprising: a toner carrier with a toner layer thereon, the toner carrier being made of an electrically conductive material; a backing electrode spaced from and facing the toner carrier; a control grid disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode; and an insulating material provided on the surface of toner carrier facing the means for passing toner.
Claim 28
Dependent Claim
74 words
An image forming apparatus comprising: a toner carrier with a toner layer thereon, the toner carrier being made of an electrically conductive material; a backing electrode spaced from and facing the toner carrier; a control grid disposed between the toner carrier and the backing electrode for selectively passing toner from the toner layer toward the backing electrode; and an insulating material provided on the surface of toner carrier facing the means for passing toner.
Claim 29
Dependent Claim
84 words
An image forming apparatus comprising: a toner carrier having a layer of magnetic toner thereon; a backing electrode spaced from and facing the toner carrier; a control grid having toner passages disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passages from the toner layer toward the backing electrode; and a magnet in the toner carrier arranged to form the toner into at least one ear extending to at least one toner passage of the control grid.
Claim 30
Dependent Claim
84 words
An image forming apparatus comprising: a toner carrier having a layer of magnetic toner thereon; a backing electrode spaced from and facing the toner carrier; a control grid having toner passages disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passages from the toner layer toward the backing electrode; and a magnet in the toner carrier arranged to form the toner into at least one ear extending to at least one toner passage of the control grid.
Claim 31
Dependent Claim
144 words
In a method for forming an image with an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, a control grid having a toner passage disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passage from the toner layer toward the backing electrode and means for applying a control signal to the control grid for selectively controlling the passage of toner through the toner passage, the improvement comprising the steps of: providing a pulsed voltage signal as the control signal applied to the control grid, and adjusting at least on of the duty ratio and pulse length of said pulsed voltage signal dependant on variations of the distance between the control grid and at least one of the toner carrier and the backing electrode.
Claim 32
Dependent Claim
144 words
In a method for forming an image with an image forming apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, a control grid having a toner passage disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passage from the toner layer toward the backing electrode and means for applying a control signal to the control grid for selectively controlling the passage of toner through the toner passage, the improvement comprising the steps of: providing a pulsed voltage signal as the control signal applied to the control grid, and adjusting at least on of the duty ratio and pulse length of said pulsed voltage signal dependant on variations of the distance between the control grid and at least one of the toner carrier and the backing electrode.
Claim 33
Dependent Claim
183 words
In an image forming apparatus having a first mode of operation for forming a predefined image a second mode of operation wherein no predefined image is formed, the apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, and a control grid disposed in a plane and having toner passages disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passages from the toner layer toward the backing electrode, the apparatus defining a first area along the backing electrode wherein an image is formed by toner passing through the control grid and a second area along the backing electrode wherein no controlled image is formed, wherein the improvement comprises: chargeable means for carrying a charge having a polarity opposite to that of the charge of the backing electrode, said chargeable means located in the same plane as the control grid, adjacent the second area along the backing electrode; and means for applying the chargeable means with said charge of opposite polarity during the second mode of operation.
Claim 34
Dependent Claim
183 words
In an image forming apparatus having a first mode of operation for forming a predefined image a second mode of operation wherein no predefined image is formed, the apparatus having a toner carrier with a toner layer thereon, a backing electrode spaced from and facing the toner carrier, and a control grid disposed in a plane and having toner passages disposed between the toner carrier and the backing electrode for selectively passing toner through the toner passages from the toner layer toward the backing electrode, the apparatus defining a first area along the backing electrode wherein an image is formed by toner passing through the control grid and a second area along the backing electrode wherein no controlled image is formed, wherein the improvement comprises: chargeable means for carrying a charge having a polarity opposite to that of the charge of the backing electrode, said chargeable means located in the same plane as the control grid, adjacent the second area along the backing electrode; and means for applying the chargeable means with said charge of opposite polarity during the second mode of operation.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |