Electrophotography – Control of electrophotography process – Control of fixing
Reexamination Certificate
2001-04-04
2002-05-21
Grimley, Arthur T. (Department: 2852)
Electrophotography
Control of electrophotography process
Control of fixing
C219S216000, C399S328000, C399S333000
Reexamination Certificate
active
06393230
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device for use in an image forming apparatus such as a copier, printer, facsimile device, etc., and particularly to a fixing device for instantaneous heating practicable quick start fixing, and an image forming apparatus therewith.
Conventionally, as a fixing device for use in an image forming apparatus such as a facsimile device, or the like, a heat roller fixing type device is widely adopted from a low speed apparatus to a high speed apparatus, and from a monochromatic apparatus to a full-color apparatus, as the fixing device which has the high technical complication degree and stability.
However, in the conventional heat roller fixing type fixing device, when transfer material or toner is heated, it is necessary that a fixing roller having a large thermal capacity is heated, therefore, the effect of energy conservation is not good, and it is disadvantageous to the phase of the energy conservation, and when printing, it takes a long period of time to warm up the fixing device, therefore the print time (warming up time) takes a long period of time, which is a problem.
In order to solve these problems, a film fixing type fixing device in which a film (heat fixing film) is used, and the thickness of the heat roller is decreased to that of heat fixing film which is the ultimate thickness and the thermal capacity of the heat roller is decreased, and heat conduction efficiency is greatly improved by directly pressure-contacting the temperature controlled-heater (ceramic heater) onto the heat fixing film, and the energy conservation and the quick start which requires almost no warming-up time are intended, and an image forming apparatus therewith are proposed and used recently.
Further, a fixing method in which, as a variation of the heat roller, a ray-transmitting base member is used as a heat-applying roller (a rotary member for applying heat), and a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) provided therein is radiated onto toner and thereby heating and fixing is conducted, and the quick start which requires almost no warming-up time, is intended, is disclosed in Japanese Tokkaisho No. 52-106741, No. 57-82240, No. 57-102736, No. 57-102741, etc. Further, a fixing method, in which a ray absorbing layer is provided on outer peripheral surface of the ray-transmitting base member and thereby, the heat-applying roller (a rotary member for applying heat) is structured, and a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) provided inside the cylindrical ray-transmitting base member is absorbed in the ray absorbing layer provided on the outer peripheral surface of the ray-transmitting base member, and the toner image is fixed by the heat of the ray-absorbing layer, is disclosed in Japanese Tokkaisho No. 59-65867.
However, in the method in which a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) is radiated through the ray-transmitting base member onto toner and thereby heating and fixing is conducted, disclosed in Japanese Tokkaisho No. 52-106741, etc., and in the method in which a ray absorbing layer is provided on outer peripheral surface of the ray-transmitting base member and thereby, the heat-applying roller (a rotary member for applying heat) is structured, a ray from a heat ray filament (a ray generating source) of a halogen lamp (a ray radiation device for radiating ray) is radiated through the ray-transmitting base member onto the ray absorbing layer, and the toner is fixed by the heat of the ray-absorbing layer, the energy conservation and the quick start in which the warming-up time is reduced, are intended, however, the problem occurs that, by the diffusion of the heat to the ray-transmitting base member side in the axial direction (in the radial direction from the center axis of the rotary member for applying heat) of the rotary member for applying heat, instantaneous heating is not conducted. That is, by the flowing-away of the heat from the ray absorbing layer toward the inside, the problem occurs that quick temperature rise-up of the surface temperature of the ray absorbing layer is not carried out.
Further, a problem occurs that, when the transfer material is continuously passing through at the time of fixing, the heat in the lateral direction (in the direction perpendicular to the feeding direction of the transfer material) including the sheet passing section and the sheet non-passing section of the roll-like rotary member for applying heat becomes uneven, and the uniformity of the heat in the lateral direction of the rotary member for applying heat is not obtained. That is, the problem occurs that the uniformity of the heat can not be obtained by the temperature change.
Further, in the above fixing methods, only the ray absorbing layer does not have the heat accumulation action, therefore, the temperature lowering or unevenness of the heat occurs due to the flow-away of the heat from the rotary member for applying heat to the transfer material or to the rotary member for fixing (the fixing roller) provided on the lower side, opposed to the rotary member for applying heat. This occurs from the problem that the temperature of the ray-transmitting base member of the inside of the rotary member for applying heat is low, therefore, the heat is not supplied to the ray absorbing layer, and the temperature stabilization of the ray absorbing layer is not carried out.
Further, in the above fixing methods, a problem that the temperature rising-up speed of the ray absorbing layer of the surface is fast and only the surface is heated, however, the temperature inside the heat applying roller is low, therefore, when print start is conducted soon, the low temperature fixing offset is generated, occurs.
Further, in the above fixing methods, the temperature of the ray absorbing layer of the surface is raised fast, but the temperature inside the rotary member for applying heat hardly rises, and therefore, an appropriate temperature control is not conducted by only detection of the surface temperature of the rotary member for applying heat, and a problem occurs that the low temperature fixing offset is generated.
Further, in the conventional heat roller, the heat roller is heated from the inside of the metallic pipe having good thermal conductivity by a halogen heater, and structured by providing a rubber layer, which is easily deteriorated by heating and has poor thermal conductivity, on the outside (the outer peripheral surface) of the metallic pipe, and it has poor responsibility and the inside temperature is higher than the outside temperature, and has a limitation of the quick start (quick heating). In contrast to this, in the above fixing methods, although the temperature of the ray absorbing layer of the surface can be raised up faster, the inside of the rotary member for applying heat is cool and the temperature is low, therefore, the temperature rise-up technology for such type of a rotary member for applying heat is necessary.
Further, in the above fixing methods, not only the kind of the transfer materials but the inside temperature of the rotary member for applying heat or the temperature of the rotary member for fixing located on the lower side of the rotary member for applying heat influence on the fixing device, and the temperature of the ray absorbing layer of the surface of the rotary member for applying heat rises fast, but the inside temperature hardly rises, therefore, the temperature control for high responsibility is required for the rotary member for applying heat whose temperature lowering is fast.
Further, in an image forming apparatus using the above fixing methods, depending on the temperature of the inside of the rotary member for applying heat, or the temperature of the rotary member for applying heat and the rotary member for fixing provided opposed to the rotary member for applying
Haneda Satoshi
Shigeta Kunio
Tokimatsu Hiroyuki
Bierman, Muserlian and Lucas
Grimley Arthur T.
Konica Corporation
Ngo Hoang
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