US5911094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fixing device and image forming apparatuse using the same
Assignee: Minolta Co Ltd
•
Filing: 1997-09-16
•
Granted: 1999-06-08
•
Expires: 2017-09-16
Abstract
Abstract An induction heating type fixing device for causing a toner image formed on a sheet to be fixed on the sheet. This fixing device contains a fixing roller formed of a conductive member in a cylindrical shape, a core passed through the interior of the fixing roller and intended to form a closed magnetic circuit, an induction coil wound around the core, a power source for forwarding an alternating circuit to the induction coil, a switch for passing or breaking the alternating current supplied from the power source to the induction coil, an electric current amount detecting coil for detecting the amount of an electric current flowing from the power source to the induction coil, a thermistor for detecting the temperature of the fixing roller, and a CPU for controlling the switch so as to forward an alternating current to the induction coil until the amount of the electric current detected by the electric current amount detecting coil reaches a prescribed amount and, after the amount of the electric current detected by the electric current amount detecting coil has reached the prescribed amount, controlling the switch so as to repeat the passage and the breakage of the alternating current to the induction coil and enable the temperature of the fixing roller to be retained at a predetermined temperature fit for the fixation of the toner image.
Inventors
- 👤 Takahiko Tsujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:08
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2039; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1913; G05D23/1917; G05D23/20; G05D23/24
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
184 words
An image forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a switching circuit which passes or breaks the low frequency alternating current supplied from said power source part to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; a temperature sensor which detects the temperature of said fixing roller; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the temperature detected by said temperature sensor.
Claim 2
Dependent Claim
184 words
An image forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a switching circuit which passes or breaks the low frequency alternating current supplied from said power source part to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; a temperature sensor which detects the temperature of said fixing roller; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the temperature detected by said temperature sensor.
Claim 3
Dependent Claim
36 words
An image-forming apparatus according to claim 1, wherein said detector detects an induced electromotive force generated by the low frequency alternating current flowing through a wire laid between said power source part and said induction coil.
Claim 4
Dependent Claim
32 words
An image-forming apparatus according to claim 1, wherein said power source part guides an electric current supplied from a commercial power source to said induction coil as the low frequency alternating current.
Claim 5
Dependent Claim
41 words
An image-forming apparatus according to claim 1, wherein said controller interrupts the supply of the low frequency alternating current to said induction coil when the amount of the low frequency alternating current detected by said detector lowers to said prescribed amount.
Claim 6
Dependent Claim
23 words
An image-forming apparatus according to claim 1, wherein the low frequency alternating current is in the range of 50 Hz to 60 Hz.
Claim 7
Dependent Claim
23 words
An image-forming apparatus according to claim 1, wherein the low frequency alternating current coil decreases as the temperature of said induction coil increases.
Claim 8
Dependent Claim
35 words
An image-forming apparatus according to claim 1, wherein said detector includes a rectifier for converting a detected alternating current signal into a direct current signal, and said direct current signal is provided to said controller.
Claim 9
Dependent Claim
28 words
An image-forming apparatus according to claim 1, wherein said switching circuit is a solid state relay switch which prevents noise from said power source from entering said controller.
Claim 10
Dependent Claim
107 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; and a controller which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 11
Dependent Claim
107 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; and a controller which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 12
Dependent Claim
36 words
An image-forming apparatus according to claim 9, wherein said detector detects an induced electromotive force generated by the low frequency alternating current flowing through a wire laid between said power source part and said induction coil.
Claim 13
Dependent Claim
32 words
An image-forming apparatus according to claim 9, wherein said power source part guides an electric current supplied from a commercial power source to said induction coil as the low frequency alternating current.
Claim 14
Dependent Claim
21 words
An image-forming apparatus according to claim 9, which further comprises a display part which displays the time predicted by said controller.
Claim 15
Dependent Claim
23 words
An image-forming apparatus according to claim 9, wherein the low frequency alternating current is in the range of 50 Hz to 60 Hz.
Claim 16
Dependent Claim
22 words
An image-forming apparatus according to claim 9, wherein the low frequency alternating current decreases as the temperature of said induction coil increases.
Claim 17
Dependent Claim
35 words
An image-forming apparatus according to claim 9, wherein said detector includes a rectifier for converting a detected alternating current signal into a direct current signal, and said direct current signal is provided to said controller.
Claim 18
Dependent Claim
177 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior or said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a switching circuit which passes or breaks the low frequency alternating current supplied from said power source part to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the amount of the low frequency alternating current detected by said detector.
Claim 19
Dependent Claim
177 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior or said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a switching circuit which passes or breaks the low frequency alternating current supplied from said power source part to said induction coil; a detector which detects the amount of the low frequency alternating current supplied from said power source part to said induction coil; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the amount of the low frequency alternating current detected by said detector.
Claim 20
Dependent Claim
36 words
An image-forming apparatus according to claim 11, wherein said detector detects an induced electromotive force generated by the low frequency alternating current flowing through a wire laid between said power source part and said induction coil.
Claim 21
Dependent Claim
32 words
An image-forming apparatus according to claim 16, wherein said power source part guides an electric current supplied from a commercial power source to said induction coil as the low frequency alternating current.
Claim 22
Dependent Claim
39 words
An image-forming apparatus according to claim 16, wherein said controller interrupts the supply of the low frequency alternating current to said induction coil when the amount of the electric current detected by said detector lowers to said prescribed level.
Claim 23
Dependent Claim
23 words
An image-forming apparatus according to claim 16, wherein the low frequency alternating current is in the range of 50 Hz to 60 Hz.
Claim 24
Dependent Claim
26 words
An image-forming apparatus according to claim 16, wherein the low frequency alternating current in said induction coil decreases as the temperature of said induction coil increases.
Claim 25
Dependent Claim
35 words
An image-forming apparatus according to claim 16, wherein said detector includes a rectifier for converting a detected alternating current signal into a direct current signal, and said direct current signal is provided to said controller.
Claim 26
Dependent Claim
28 words
An image-forming apparatus according to claim 16, wherein said switching circuit is a solid state relay switch which prevents noise from said power source from entering said controller.
Claim 27
Dependent Claim
125 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a controller which effects such a control as to elevate the temperature of said fixing roller to a prescribed temperature and, at the same time, retain said prescribed temperature by supplying the low frequency alternating current from said power source part to said induction coil; and a detector disposed on a wire for supplying the low frequency alternating current from said power source part to said induction coil and adapted to detect the fact that a current is flowing through said wire.
Claim 28
Dependent Claim
125 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a controller which effects such a control as to elevate the temperature of said fixing roller to a prescribed temperature and, at the same time, retain said prescribed temperature by supplying the low frequency alternating current from said power source part to said induction coil; and a detector disposed on a wire for supplying the low frequency alternating current from said power source part to said induction coil and adapted to detect the fact that a current is flowing through said wire.
Claim 29
Dependent Claim
36 words
An image-forming apparatus according to claim 24, wherein said detector detects an induced electromotive force generated by the low frequency alternating current flowing through the wire laid between said power source part and said induction coil.
Claim 30
Dependent Claim
28 words
An image-forming apparatus according to claim 24, wherein said power source part guides the low frequency alternating current supplied from a commercial power source to said induction coil.
Claim 31
Dependent Claim
41 words
An image-forming apparatus according to claim 24, wherein said controller interrupts the supply of the low frequency alternating current to said induction coil when the amount of the low frequency alternating current detected by said detector lowers to said prescribed level.
Claim 32
Dependent Claim
73 words
An image-forming apparatus according to claim 24, wherein a switching circuit for passing or breaking the low frequency alternating current supplied from said power source part to said induction coil is additionally provided and said controller decides whether said induction coil and said switching circuit are functioning normally or not based on the outcome of the detection made by said detector and a signal from the controller used for controlling said switching circuit.
Claim 33
Dependent Claim
23 words
An image-forming apparatus according to claim 24, wherein the low frequency alternating current is in the range of 50 Hz to 60 Hz.
Claim 34
Dependent Claim
26 words
An image-forming apparatus according to claim 24, wherein the low frequency alternating current in said induction coil decreases as the temperature of said induction coil increases.
Claim 35
Dependent Claim
35 words
An image-forming apparatus according to claim 24, wherein said detector includes a rectifier for converting a detected alternating current signal into a direct current signal, and said direct current signal is provided to said controller.
Claim 36
Dependent Claim
197 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a first detector disposed on a wire which supplies the low frequency alternating current from said power source part to said induction coil and is adapted to detect the fact that an electric current is flowing through said wire; a second detector which detects the open-close state of a door of said image-forming apparatus; and a controller which effects such a control as to interrupt the supply of the low frequency alternating current to said induction coil when said door is opened while the flow of the the low frequency alternating current through said wire is present in accordance with the outcome of the detection of said first detector and said second detector, and which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said first detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 37
Dependent Claim
197 words
An image-forming apparatus, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core; a power source part which supplies a low frequency alternating current to said induction coil; a first detector disposed on a wire which supplies the low frequency alternating current from said power source part to said induction coil and is adapted to detect the fact that an electric current is flowing through said wire; a second detector which detects the open-close state of a door of said image-forming apparatus; and a controller which effects such a control as to interrupt the supply of the low frequency alternating current to said induction coil when said door is opened while the flow of the the low frequency alternating current through said wire is present in accordance with the outcome of the detection of said first detector and said second detector, and which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said first detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 38
Dependent Claim
170 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction coil; a detector which detects the amount of the low frequency alternating current supplied to said induction coil, a temperature sensor which detects the temperature of said fixing roller; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the temperature detected by said temperature sensor.
Claim 39
Dependent Claim
170 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction coil; a detector which detects the amount of the low frequency alternating current supplied to said induction coil, a temperature sensor which detects the temperature of said fixing roller; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the temperature detected by said temperature sensor.
Claim 40
Dependent Claim
99 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a detector which detects the amount of the low frequency alternating current supplied to said induction coil; and a controller which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said detector and, based on the estimated temperature, predicting the time which elapses until the prescribed temperature is reached.
Claim 41
Dependent Claim
99 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a detector which detects the amount of the low frequency alternating current supplied to said induction coil; and a controller which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said detector and, based on the estimated temperature, predicting the time which elapses until the prescribed temperature is reached.
Claim 42
Dependent Claim
164 words
A fixing device, comprising a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction coil; a detector which detects the amount of the low frequency alternating current supplied to said induction coil; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the amount of the low frequency alternating current detected by said detector.
Claim 43
Dependent Claim
164 words
A fixing device, comprising a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction coil; a detector which detects the amount of the low frequency alternating current supplied to said induction coil; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction coil until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction coil based on the amount of the low frequency alternating current detected by said detector.
Claim 44
Dependent Claim
113 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a controller which effects such a control as to elevate the temperature of said fixing roller to a prescribed temperature and retain said prescribed temperature by supplying the low frequency alternating current to said induction coil; and a detector disposed on a wire for supplying the low frequency alternating current from said power source part to said induction coil and adapted to detect the fact that a current is flowing through said wire.
Claim 45
Dependent Claim
113 words
A fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a controller which effects such a control as to elevate the temperature of said fixing roller to a prescribed temperature and retain said prescribed temperature by supplying the low frequency alternating current to said induction coil; and a detector disposed on a wire for supplying the low frequency alternating current from said power source part to said induction coil and adapted to detect the fact that a current is flowing through said wire.
Claim 46
Dependent Claim
189 words
An fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a first detector disposed on a wire supplying the low frequency alternating current to said induction coil and adapted to detect the fact that an electric current is flowing through said wire; a second detector which detects the open-close state of a door of a housing accommodating said fixing device; and a controller which effects such a control as to interrupt the supply of the low frequency alternating current to said induction coil when said door is opened while the flow of the low frequency alternating current through said wire is present in accordance with the outcome of the detection of said first detector and said second detector, and which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said first detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 47
Dependent Claim
189 words
An fixing device, comprising: a fixing roller formed of a conductive member; a core passing the interior of said fixing roller; an induction coil wound around said core and supplied with a low frequency alternating current from a power source; a first detector disposed on a wire supplying the low frequency alternating current to said induction coil and adapted to detect the fact that an electric current is flowing through said wire; a second detector which detects the open-close state of a door of a housing accommodating said fixing device; and a controller which effects such a control as to interrupt the supply of the low frequency alternating current to said induction coil when said door is opened while the flow of the low frequency alternating current through said wire is present in accordance with the outcome of the detection of said first detector and said second detector, and which estimates the temperature of said fixing roller based on the amount of the low frequency alternating current detected by said first detector and, based on the estimated temperature, predicts the time which elapses until a prescribed temperature is reached.
Claim 48
Dependent Claim
146 words
A fixing apparatus comprising: an induction heating device using a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction heating device; a detector which detects the amount of the low frequency alternating current supplied to said induction heating device; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction heating device until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction heating device based on the amount of the low frequency alternating current detected by said detector.
Claim 49
Dependent Claim
146 words
A fixing apparatus comprising: an induction heating device using a low frequency alternating current from a power source; a switching circuit which passes or breaks the low frequency alternating current supplied to said induction heating device; a detector which detects the amount of the low frequency alternating current supplied to said induction heating device; and a controller which controls said switching circuit so as to supply the low frequency alternating current to said induction heating device until the amount of the low frequency alternating current detected by said detector reaches a prescribed amount and, after the amount of the low frequency alternating current detected by said detector has reached said prescribed amount, controls said switching circuit so as to pass or break the low frequency alternating current to said induction heating device based on the amount of the low frequency alternating current detected by said detector.
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) | 2002-06-07 | 2002-12-07 | 2003-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-07 | 2006-12-07 | 2007-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-07 | 2010-12-07 | 2011-06-08 | $7700.00 | Window Closed / Lapsed |