Source: http://www.google.com/patents/US8190074?ie=ISO-8859-1
Timestamp: 2014-07-11 11:22:33
Document Index: 473856140

Matched Legal Cases: ['art.\n3', 'art.\n7', 'art.\n17', 'Application No. 2007', 'art 21', 'art 41', 'art 41', 'art 45', 'art 41', 'art 41', 'art 41']

Patent US8190074 - Fixing device and image forming apparatus having the same - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA fixing device to fix an image to a print medium, including: a pressing roller, which is driven to rotate; a heat transferring unit facing the pressing roller, and contacting the pressing roller at a fixing nip position, to heat to a print medium disposed at the fixing nip position; a heating member...http://www.google.com/patents/US8190074?utm_source=gb-gplus-sharePatent US8190074 - Fixing device and image forming apparatus having the sameAdvanced Patent SearchPublication numberUS8190074 B2Publication typeGrantApplication numberUS 12/047,534Publication dateMay 29, 2012Filing dateMar 13, 2008Priority dateMay 21, 2007Also published asCN101311845A, EP1995646A2, EP1995646A3, US20080292372Publication number047534, 12047534, US 8190074 B2, US 8190074B2, US-B2-8190074, US8190074 B2, US8190074B2InventorsJi-min HANOriginal AssigneeSamsung Electronics Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (14), Non-Patent Citations (1), Classifications (8), Legal Events (1) External Links: USPTO, USPTO Assignment, EspacenetFixing device and image forming apparatus having the sameUS 8190074 B2Abstract A fixing device to fix an image to a print medium, including: a pressing roller, which is driven to rotate; a heat transferring unit facing the pressing roller, and contacting the pressing roller at a fixing nip position, to heat to a print medium disposed at the fixing nip position; a heating member that presses an portion of the heat transferring unit against the pressing roller at the fixing nip position; and a heat source that heats a preheating position of the heat transferring unit, and heats the heating member.
a heat transferring unit that is rotatably supported to face the pressing roller at a fixing nip position, to transfer heat to a print medium disposed at the fixing nip position to fix an image thereto;
a heating member disposed inside the heat transferring unit, comprising:
a heat conducting part having a surface that faces a preheating position and a heat source; and
a pressing part connected to the heat conducting part, to support the heat transferring unit at the fixing nip position, and to conduct heat from heat conducting part to the heat transferring unit at fixing nip position, wherein
the heat source is disposed between the heat transferring unit and the heating member, to heat the preheating position of the heat transferring unit, which is adjacent to the fixing nip position, and to heat the heating member, and
wherein the heat conducting part is disposed between the heat source and the pressing part.
3. The fixing device as claimed in claim 1, wherein the surface of the heat conducting part reflects a portion of the heat from the heat source toward the heat transferring unit at the preheating position.
4. The fixing device as claimed in claim 1, wherein the pressing part has a thickness that decreases from the heat conducting part to the fixing nip position.
5. The fixing device as claimed in claim 1, wherein the heat source comprises a heating lamp which is disposed between and spaced apart from the heat conducting part and the heat transferring unit.
6. The fixing device as claimed in claim 1, wherein the heat source comprises a ceramic heater disposed directly upon the surface of the heat conducting part.
7. The fixing device as claimed in claim 1, wherein the heat transferring unit comprises a flexible material.
8. The fixing device as claimed in claim 7, wherein the heat transferring unit is rotated by a rotation of the pressing roller.
9. The fixing device as claimed in claim 1, wherein the pressing part has a curvature that corresponds to a curvature of the heat transferring unit.
10. The fixing device as claimed in claim 1, wherein the surface has a concave shape to reflect a portion of the heat from the heat source toward the preheating position.
a transferring unit to transfer the toner image to a print medium to form a print image; and
a heat transferring unit that is rotatably supported to face the pressing roller at a fixing nip position, and to heat a print medium disposed at the fixing nip position to fix an image thereto; and
12. The image forming apparatus according to claim 11, wherein the heat source radiates heat to the preheating position of the heat transferring unit.
13. The image forming apparatus as claimed in claim 12, wherein the pressing part has a thickness that decreases from the heat conducting part to the fixing nip position.
14. The image forming apparatus as claimed in claim 12, wherein the heat source comprises a heating lamp which is disposed between and spaced apart from the heat conducting part and the heat transferring unit.
15. The image forming apparatus as claimed in claim 11, wherein the first surface is to reflect a portion of the heat from the heat source toward the preheating position.
16. The image forming apparatus as claimed in claim 11, wherein the heat source comprises a ceramic heater disposed directly upon the first surface of the heat conducting part.
17. The image forming apparatus as claimed in claim 11, wherein the heat transferring unit comprises a flexible material.
19. The image forming apparatus as claimed in claim 11, wherein the surface at least partially defines the preheating position.
20. The image forming apparatus as claimed in claim 11, wherein the pressing part has a curvature that corresponds to a curvature of the heat transferring unit.
21. The image forming apparatus as claimed in claim 11, wherein the surface has a concave shape to reflect a portion of the heat from the heat source toward the preheating position. Description
CROSS-REFERENCE TO RELATED APPLICATIONS This application claims all benefits accruing under 35 U.S.C. �119 from Korean Patent Application No. 2007-49236, filed on May 21, 2007, in the Korean Intellectual Property Office the disclosure of which is incorporated herein by reference.
The heating roller 3 includes a core pipe 3 a formed of metal, and an elastic layer 3 b disposed on the core pipe 3 a. Radiant energy from the heating lamp 1 is converted into heat by a light-heat converting layer (not shown) disposed on an inner surface of the first core pipe 3 a, to heat the core pipe 3 a. Also, the elastic layer 3 b is heated by thermal conduction to a predetermined fixing temperature.
The temperature sensor 7 can contact, or be adjacent to, the heating roller 3 and measures a surface temperature of the elastic layer 3 a. Accordingly, power supplied to the heating lamp 1 can be adjusted, based on the surface temperature measured by the temperature sensor 7.
The pressing roller 5 includes a core pipe 5 a formed of metal, and an elastic layer 5 b disposed thereon. The elastic layer 5 b has less elasticity than the elastic layer 3 b, and the elastic layer 5 b is distorted when pressed against the pressing roller 5. When a print medium 9 having a toner image 9 a passes through the fixing nip position N1, the toner image is heated, pressed, and thereby fixed to the print medium 9.
To increase the speed of the image forming apparatus employing the fixing device, the external diameters of the heating roller and the pressing roller can be increased, or the thickness of the elastic layers 3 b and 5 b can be increased. Such modifications increase a fixing time of the print medium in the fixing nip position N1, by enlarging the width of the fixing nip position N1, in order to compensate for an increased speed of the image forming apparatus. Such modifications prevent a fixing quality deterioration caused by a decrease of the fixing time of the print medium.
SUMMARY OF THE INVENTION Aspects of the present invention provide a fixing device to concentrate heat on a fixing nip position in a preheating operation. The fixing device prevents a pressing member from being damaged, by a rapidly cooling the pressing member if a print medium is not transported. Aspects of the present invention relate to an image forming apparatus including the fixing device.
FIG. 1 is a schematic sectional view illustrating a conventional fixing device;
FIG. 2 is a schematic sectional view illustrating a fixing device, according to an exemplary embodiment of the present invention;
FIG. 3 is a schematic sectional view illustrating a fixing device, according to an exemplary embodiment of the present invention;
FIG. 4 is a graph comparing temperature distribution variations, over time, of the fixing device, according to an exemplary embodiment of the present invention, with a fixing device of a conventional example; and
FIG. 5 schematically illustrates an image forming apparatus, according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below in order to explain the present invention by referring to the figures.
The heat transferring unit 11 is rotatably supported and faces the pressing roller 13, such that a print medium P can be disposed therebetween. The heat transferring unit 11 guides a feeding of the print medium P. The heat transferring unit 11 transfers heat supplied from the heat source 15, via the heating member 20, to the print medium P. The heat transferring unit 11 includes a heat transferring layer 11 a, and a release layer 11 b formed on the heat transferring layer 11 a. The release layer 11 b can prevent the print medium P from sticking thereto during and/or after fixing.
The heat conducting part 21 may further include a reflecting face 21 a, to reflect part of the heat radiated from the heat source 15, toward the heat transmitting unit 11. The reflecting face 21 a may have a concave shape, so that the heat radiated from the heat source 15 can be concentrated on the preheating position HP.
The heat source 35 may include a ceramic heater disposed on a surface of the heat conducting part 41, facing the heat transferring unit 31. Heat from the heat source 35 is directly transferred to the heat conducting part 41, thereby rapidly heating the fixing nip position N2. The pressing part 45 may get relatively thinner from the heat conducting part 41 to the fixing nip position N2. Accordingly, the total area of the fixing nip position N2 can maintain a uniform temperature.
The fixing device 300 may have substantially the same configuration as the fixing device 200, except for the configuration of the heat source 35 and the heating member. For example, the heat conducting part 41 is depicted as having a flat portion to accommodate the heat source 35. The heat conducting part 41 can be any shape suitable to direct heat from the heat source toward the preheating position HP.
FIG. 4 is a graph comparing temperature distribution variations over time, of the fixing device 200 to a conventional fixing device. Referring to FIG. 4, it takes approximately 10 seconds to increase the temperature of the conventional fixing device to approximately 120� C. On the other hand, it takes approximately 6 second to increase the temperature of the fixing device 200 to approximately 120� C.
The fixing device 200 demonstrates a more rapid temperature increase as compared with the conventional fixing device. Also, the fixing device 200 can maintain a temperature of approximately 140� C. after approximately 8 seconds of heating. Accordingly, if a width of the fixing nip position N2 is small, or a fixing time is shortened due to increase of a feeding speed of the print medium, the fixing device 200 can increase a heat flux, thereby maintaining suitable fixing characteristics.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4071735 *Nov 1, 1976Jan 31, 1978Xerox CorporationExternally heated low-power roll fuserUS4435069 *Sep 3, 1982Mar 6, 1984Fuji Photo Film Co., Ltd.Fixing apparatus for electrophotographyUS5873020 *Nov 12, 1996Feb 16, 1999Minolta Co., Ltd.Fixing device with endless beltUS6519439 *Mar 21, 2001Feb 11, 2003Ricoh Company, Ltd.A method of fixing a toner image on a support, which includes the steps of heating a toner image formed on a support by use of a toner to the softening point or melting point of the toner or above, using an image fixing member, the tonerUS6611670 *Dec 4, 2001Aug 26, 2003Nexpress Solutions LlcLoading system includes pair of pneumatic cylinders; pressure equalization tank; electrographyUS20020051659 *Sep 5, 2001May 2, 2002Motofumi BabaImage forming apparatus and fixing deviceUS20030053830 *Nov 1, 2002Mar 20, 2003Toshiharu HachisukaMethod and apparatus for image forming capable of effectively performing an image fixing processUS20030206758 *Jun 19, 2003Nov 6, 2003Motokazu YasuiFixing device preventing rubbing of toner imageUS20050265758 *Feb 8, 2005Dec 1, 2005Shigehiko HasebaFixing device and image forming apparatusUS20060177251 *Aug 23, 2005Aug 10, 2006Fuji Xerox Co., Ltd.Fixing device and image forming apparatusJP2001324887A * Title not availableJP2006184623A * Title not availableJP2007233236A * Title not availableKR20060009551A Title not available* Cited by examinerNon-Patent CitationsReference1Korean Office Action issued Jun. 17, 2011 in corresponding Korean Patent Application 10-2007-0049236.Classifications U.S. Classification399/328International ClassificationG03G15/20Cooperative ClassificationG03G2215/2035, G03G15/2021, G03G15/2053, G03G15/2028, G03G15/2078European ClassificationG03G15/20H2P3Legal EventsDateCodeEventDescriptionMar 14, 2008ASAssignmentOwner name: SAMSUNG ELECTRONICS CO., LTD., KOREA, REPUBLIC OFFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HAN, JI-MIN;REEL/FRAME:020677/0727Effective date: 20080312RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google