JP2002023538A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device in which the heat from heat ray irradiating means is transferred without time-lag in respective layers of a rotating member for light ray fixation and the uniform and stable heating of a heat ray absorbing layer is performed. SOLUTION: This fixing device features that calorific value per unit heat capacity of the layer which is closer to the surface layer is larger than that of another layer which is adjacent to the inside when the calorific value per unit heat capacity is compared with respect to the adjacent two layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used for an image forming apparatus such as a copying machine, a printer, a facsimile, etc., and more particularly to a fixing device capable of quick start.

[0002]

2. Description of the Related Art Conventionally, as a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., a halogen heater (heating means) is provided inside a metal pipe (substrate). ), And a heat roller fixing method using a heat roller having a structure for heating a rubber layer (elastic body) outside a metal pipe is widely used from a low-speed machine to a high-speed machine, from a monochrome machine to a full-color machine. .

However, in a conventional heat roller fixing type fixing device using a heat roller, when a transfer roller or toner is heated by a heat roller having a halogen heater inside, a heat roller for fixing having a large heat capacity is heated. However, there is a problem that the energy saving effect is poor due to the necessity, and the energy saving is disadvantageous. Further, there is a problem that it takes time to warm up the fixing device at the time of printing, and the printing time (warming up time) becomes long.

In order to solve this, a film (heat fixing film) is used, the heat roller is brought to the ultimate thickness of the heat fixing film to reduce the heat capacity, and a temperature-controlled heater (ceramic heater) is directly applied to the heat fixing film. A film fixing type fixing device and an image forming device using the same have been proposed, which greatly improve the heat conduction efficiency by being brought into contact with the pressure and achieve energy saving and a quick start requiring almost no warm-up time. Have been

Further, as a modification of the heat roller, a transparent substrate is used as a heat ray fixing roller (rotating member for heat ray fixing), and the toner is heated and fixed by irradiating the toner with heat rays from a halogen lamp (heat ray irradiation means) provided inside. A fixing method which does not require a warm-up time and achieves a quick start is disclosed in JP-A-52-106741, JP-A-57-82240, JP-A-57-102736, and JP-A-57-10274.
No. 1 and the like. Further, a light absorbing layer (heat ray absorbing layer) is provided on the outer peripheral surface of the light transmitting substrate to constitute a heat ray fixing roller (rotating member for heat ray fixing), and a halogen lamp (heat ray) provided inside the cylindrical light transmitting substrate. JP-A-59-65867 discloses a fixing method in which light from the irradiating means is absorbed by a light-absorbing layer provided on the outer peripheral surface of a light-transmitting substrate, and a toner image is fixed by heat of the light-absorbing layer. ing.

However, the above-mentioned Japanese Patent Application Laid-Open No. Sho 52-1067.
In the fixing device disclosed in Japanese Patent Application Laid-open No. 41-41, a method of irradiating heat rays from a halogen lamp (heat ray irradiating means) through a translucent substrate to heat and fix the toner is disclosed.
In the fixing device disclosed in Japanese Patent Application Laid-Open No. 9-65867, a light absorbing layer (heat ray absorbing layer) is provided on the outer peripheral surface of a light-transmitting substrate to constitute a heat ray fixing roller (rotating member for heat ray fixing), and a halogen lamp (heat ray irradiation). Means) is to irradiate the heat ray absorbing layer through the translucent substrate to the heat ray absorbing layer and fix the toner by the heat of the heat ray absorbing layer, thereby achieving energy saving and quick start in which the warm-up time is shortened, respectively. However, since the fixing property is poor, the inventors of the present application used a halogen lamp (heat ray irradiating means) and provided a translucent elastic material comprising a rubber material layer between the light transmissive substrate and the light absorbing layer (heat ray absorbing layer). The heat ray fixing roller (rotating member for heat ray fixing) of the soft roller is formed by providing the layer, and the heat ray absorbing layer is heated by the heat ray from the halogen lamp (heat ray irradiating means), and the quick start ( Fast heating) are possible, JP-fixing apparatus for and improve the fixing of the toner image 11-327341
No. and other publications.

[0007]

However, in the heat-fixing rotary member proposed above, the temperature of the heat-absorbing layer of the surface layer having a small heat capacity rises quickly, and the heat-absorbing layer of the surface layer is hot, but the internal light-transmitting substrate is formed. And the temperature of the translucent elastic layer is slow, and the heat of the surface layer is easily taken inside during warm-up or fixing, and the temperature of the heat ray absorbing layer on the surface layer becomes unstable or non-uniform. Occur.

The present invention solves the above-mentioned problems, and the heat from the heat ray irradiating means is transmitted without time delay in each layer of the heat ray fixing rotating member, so that the heat ray absorbing layer is uniformly and stably heated. A first object is to provide a fixing device.

In the above-mentioned proposed rotating member for fixing a heat ray, the heat ray absorbing layer on the surface layer has a small heat capacity, and the heat ray absorbing layer on the surface layer is hot but has no heat storage. The temperature of the layer is low, the temperature of the heat ray absorbing layer on the surface of the rotating member for heat ray fixing is greatly reduced when the transfer material is passed, and the fixability differs at the leading and trailing ends of the transfer material. The problem arises that is not done. Also, there is a problem that the fixability differs between when forming a color image and when forming a monochrome image.

The present invention also solves the above-mentioned problems. By controlling the temperature of the heat ray absorbing layer of the heat ray fixing rotating member at the time of passing the transfer material, the temperature of the heat ray absorbing layer can be reduced. It is a second object of the present invention to provide a fixing device in which the fixing properties at the end portions are made uniform and high-quality fixing is performed.

[0011] In the proposed rotating member for fixing a heat ray, the surface heat ray absorbing layer having a small heat capacity has good responsiveness and the surface heat ray absorbing layer is hot, but the internal light transmitting substrate and the light transmitting elastic layer. The temperature is low, and the temperature of the heat ray absorbing layer on the surface of the rotating member for heat ray fixing is stabilized and made uniform during continuous feeding of the transfer material, particularly, the temperature in the horizontal direction (the direction perpendicular to the direction in which the transfer material is fed) is made uniform. Therefore, there arises a problem that fixing cannot be achieved and stable high-quality image cannot be fixed.

The present invention also solves the above-mentioned problems, and stabilizes and uniformizes the temperature of the heat absorbing layer on the surface of the rotating member for fixing heat rays during continuous feeding of the transfer material, particularly, uniforms the temperature in the lateral direction. It is a third object of the present invention to provide a fixing device which has been developed.

[0013]

A first object of the present invention is to provide a cylindrical light-transmitting base having heat-ray radiating means for emitting heat rays therein and having a light-transmitting property with respect to the heat rays, A roll-shaped hot wire provided with a cylindrical light-transmitting elastic layer having a light-transmitting property with respect to the heat ray outside the conductive base, and a heat ray absorbing layer absorbing the heat ray outside the light-transmitting elastic layer; In a fixing device in which a rotating member for fixing is formed and a toner image on a transfer material is fixed to the transfer material by heating and pressurizing, when the heat generation per unit heat capacity of two adjacent layers is compared, The fixing device (first invention) is characterized in that the amount of heat generated per unit heat capacity of a layer close to the first layer is larger than the amount of heat generated per unit heat capacity of the other layer adjacent inside.

A second object of the present invention is to provide a cylindrical light-transmitting base having a heat ray radiating means for emitting heat rays therein and having a light-transmitting property with respect to the heat rays, and an outer side of the light-transmitting base. A cylindrical heat-transmissive elastic layer having a light-transmitting property with respect to the heat rays, and a heat-ray absorbing layer for absorbing the heat rays outside the light-transmissive elastic layer, and a roll-shaped heat ray fixing rotating member is provided. A fixing device for fixing the toner image on the transfer material to the transfer material by heating and pressurizing the heat ray fixing rotary member at a predetermined temperature during the passage of the transfer material. The temperature control is achieved by a fixing device (second invention) characterized in that the heat ray irradiating means is operated irrespective of the normal temperature control of the heat ray fixing rotating member.

A third object of the present invention is to provide a cylindrical light-transmitting base having heat-ray irradiating means for emitting heat rays therein and having a light-transmitting property with respect to the heat rays, and an outside of the light-transmitting base. A cylindrical heat-transmissive elastic layer having a light-transmitting property with respect to the heat rays, and a heat-ray absorbing layer for absorbing the heat rays outside the light-transmissive elastic layer, and a roll-shaped heat ray fixing rotating member is provided. A fixing device for fixing the toner image on the transfer material to the transfer material by heating and pressurizing, wherein an external heating roller member that contacts the rotating member for heat ray fixing is provided, and the rotating member for heat ray fixing is provided. The ratio (%) of the heat capacity of the external heating roller member to the fixing device is set to 10 to 30%, which is achieved by a fixing device (third invention).

[0016]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Further, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning or technical scope of the terms of the present invention.

An image forming process and each mechanism of an embodiment of an image forming apparatus using a fixing device according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional configuration view of a color image forming apparatus showing an embodiment of an image forming apparatus using a fixing device according to the present invention, FIG. 2 is an explanatory diagram showing the structure of the fixing device, and FIG. 5 is an enlarged cross-sectional configuration diagram of the roll-shaped heat ray fixing rotating member of FIG. 2, and FIG. 4 is a diagram illustrating a concentration distribution of a heat ray absorbing layer of the roll shaped heat ray fixing rotating member of FIG. FIG. 3 is a diagram showing an outer diameter and a thickness of a light-transmitting substrate of the roll-shaped heat ray fixing rotating member of FIG. 2.

Referring to FIG. 1, a photosensitive drum 10, which is an image forming member, has a light-transmitting member formed on the outer periphery of a cylindrical base formed of a light-transmitting member such as glass or light-transmitting acrylic resin. It has a conductive layer and a photoconductor layer of an organic photosensitive layer (OPC).

The photosensitive drum 10 is rotated clockwise as indicated by an arrow in FIG. 1 with the light-transmitting conductive layer grounded by power from a drive source (not shown).

In the present invention, the exposure beam for image exposure is
The photoconductor layer of the photoconductor drum 10, which is the image forming point, only needs to have an exposure light amount of a wavelength that can provide an appropriate contrast with respect to the light attenuation characteristic (photocarrier generation) of the photoconductor layer. . Therefore, the light transmittance of the light-transmitting substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic of absorbing a certain amount of light when transmitting the exposure beam. . The point is that any suitable contrast can be provided. As a material of the light-transmitting substrate, an acrylic resin, particularly one obtained by polymerizing a methyl methacrylate monomer, is preferably used because of its excellent light-transmitting properties, strength, accuracy, surface properties, etc. Various translucent resins such as acryl, fluorine, polyester, polycarbonate, polyethylene terephthalate and the like used for the above can be used. Further, as long as it has a light-transmitting property with respect to the exposure light, it may be colored. As the light-transmitting conductive layer, indium tin oxide (I
TO), tin oxide, lead oxide, indium oxide, copper iodide, or a metal thin film of Au, Ag, Ni, Al, or the like that maintains light transmissivity. Reactive deposition method, various sputtering methods, various CV
D method, dip coating method, spray coating method and the like can be used.
Various organic photosensitive layers (OPC) can be used as the photoconductor layer.

The organic photosensitive layer serving as the photosensitive layer of the photoconductor layer includes a charge generation layer (CGL) mainly composed of a charge generation substance (CGM) and a charge transport layer (CTM) mainly composed of a charge transport substance (CTM). And CTL). An organic photosensitive layer having a two-layer structure has high durability as an organic photosensitive layer due to its thick CTL and is suitable for the present invention.
The organic photosensitive layer may have a single layer structure containing a charge generation material (CGM) and a charge transport material (CTM) in one layer. ,
Usually, a binder resin is contained.

A scorotron charger 11 as a charging unit described below, and an exposure optical system 1 as an image writing unit will be described.
2. The developing device 13 as a developing unit is prepared for an image forming process for each color of yellow (Y), magenta (M), cyan (C) and black (K), respectively. Are arranged in the order of Y, M, C, and K with respect to the rotation direction of the photosensitive drum 10 indicated by the arrow in FIG.

Scorotron charger 11 as charging means
Is mounted so as to face and be close to the photosensitive drum 10 in a direction perpendicular to the moving direction of the photosensitive drum 10 as an image forming body (the direction perpendicular to the plane of FIG. 1). A control grid (no symbol) maintained at a predetermined potential with respect to the body layer;
As a, for example, a sawtooth electrode is used, and a charging action (in this embodiment, negative charging) is performed by corona discharge having the same polarity as that of the toner, thereby giving a uniform potential to the photosensitive drum 10. As the corona discharge electrode 11a, a wire electrode or a needle electrode may be used.

The exposure optical system 12 for each color is a linear exposure element (LED) in which a plurality of LEDs (light emitting diodes) as light emitting elements for image exposure light are arranged in an array parallel to the axis of the photosensitive drum 10. (Not shown) and a selfoc lens (not shown) as an equal-magnification imaging element are configured as an exposure unit attached to a holder. An exposure optical system 1 for each color is placed on a cylindrical holder 20 as an exposure optical system holding member.
2 is mounted and housed inside the substrate of the photosensitive drum 10. Other exposure elements include FL (phosphor emission),
A linear element in which a plurality of light emitting elements such as EL (electroluminescence) and PL (plasma discharge) are arranged in an array is used.

An exposure optical system 12 as an image writing means for each color moves an exposure position on a photosensitive drum 10 between a scorotron charger 11 and a developing device 13 and a photosensitive member with respect to the developing device 13. It is arranged inside the photoconductor drum 10 in a state provided on the upstream side in the rotation direction of the drum 10.

The exposure optical system 12 performs image processing based on image data of each color sent from a separate computer (not shown) and stored in a memory, and then performs image processing on the uniformly charged photosensitive drum 10. Exposure is performed to form a latent image on the photosensitive drum 10. The emission wavelength of the light-emitting element used in this embodiment is usually 6 for the toners of Y, M, and C, which have high translucency.
The wavelength in the range of 80 to 900 nm is good, but the wavelength may be shorter than this, since the color toner does not have sufficient translucency since image exposure is performed from the back surface.

The developing device 13 as a developing means for each color includes
Inside yellow (Y), magenta (M), cyan (C)
Alternatively, it contains a black (K) two-component (or one-component) developer and is formed of, for example, a cylindrical non-magnetic stainless steel or aluminum material having a thickness of 0.5 to 1 mm and an outer diameter of 15 to 25 mm, respectively. And a developing sleeve 13a as a developer carrier.

In the developing area, the developing sleeve 13a is kept out of contact with the photosensitive drum 10 by a contact roller (not shown) with a predetermined gap, for example, 100 to 1000 μm, between the developing sleeve 13a and the rotating direction of the photosensitive drum 10. At the closest position, it rotates in the forward direction, and at the time of development, an AC voltage AC is superimposed on a DC voltage of the same polarity as the toner (in the present embodiment, a negative polarity) or a DC voltage with respect to the developing sleeve 13a. By applying the developing bias voltage, non-contact reversal development is performed on the exposed portion of the photosensitive drum 10. At this time, the precision of the development interval needs to be about 20 μm or less in order to prevent image unevenness.

As described above, the developing device 13 transfers the electrostatic latent image formed on the photosensitive drum 10 by the charging by the scorotron charger 11 and the image exposure by the exposure optical system 12 in a non-contact state. Reversal development is performed with toner having the same polarity as the charge polarity of No. 10 (in the present embodiment, the photosensitive drum is negatively charged, and the toner has negative polarity).

When the image forming body drive motor (not shown) is started by the start of image formation, the photosensitive drum 10 is rotated clockwise as shown by the arrow in FIG. 1 and at the same time, the photosensitive body is charged by the charging action of the Y scorotron charger 11. The application of the potential to the drum 10 is started. After a potential is applied to the photosensitive drum 10, exposure (image writing) by a first color signal, that is, an electrical signal corresponding to Y image data is started in the Y exposure optical system 12, and the rotation of the photosensitive drum 10 is started. By scanning, an electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface. This latent image is reversely developed in a non-contact state by the Y developing device 13, and a yellow (Y) toner image is formed on the photosensitive drum 10.

Next, the photoreceptor drum 10 places an M scorotron charger 11 on the yellow (Y) toner image.
A potential is applied by the charging action of the M exposure optical system 12
Exposure (image writing) is performed using an electrical signal corresponding to the second color signal of m, i.e., magenta (M) image data.
The magenta (M) toner image is formed on the yellow (Y) toner image by non-contact reversal development by the developing device 13.

According to the same process, the cyan (C) toner image corresponding to the third color signal is further obtained by the C scorotron charger 11, the exposure optical system 12, and the developing unit 13, and the K scorotron charger 11 , Exposure optical system 1
A black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the second and developing units 13, and a color toner image is formed on the peripheral surface within one rotation of the photosensitive drum 10. You.

As described above, in this embodiment, Y, M,
The exposure of the organic photosensitive layer of the photoconductor drum 10 by the C and K exposure optical systems 12 is performed through a transparent substrate from the inside of the photoconductor drum 10. Therefore, the exposure of the image corresponding to the second, third, and fourth color signals can form an electrostatic latent image without being shielded by the previously formed toner image, which is preferable. Photoconductor drum 1
0 may be exposed from outside.

On the other hand, the recording paper P as a transfer material is sent out from a paper feed cassette 15 as a transfer material storage means by a feed roller (no code) and fed by a feed roller (no code) to a timing roller. It is conveyed to 16.

The recording paper P is synchronized with the color toner image carried on the photosensitive drum 10 by the driving of the timing roller 16, and the paper charger 1 as a paper charging means is synchronized.
Due to the electrification of 50, the toner is attracted to the conveyor belt 14a and fed to the transfer area. The recording paper P, which is closely transported by the transport belt 14a, is moved around the photosensitive drum 10 by a transfer unit 14c as a transfer unit to which a voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied in a transfer area. The color toner images on the surface are collectively transferred to the recording paper P.

The recording paper P on which the color toner image has been transferred is
The paper is discharged by a paper separation AC neutralizer 14h as a transfer material separating unit, separated from the transport belt 14a, and transported to the fixing device 17.

The fixing device 17 includes an upper heat-fixing roller 17a serving as a hot-roll fixing rotating member for fixing a color toner image, and a lower-roll fixing device paired with the upper heat-ray fixing roller 17a. Halogen lamp HLa, xenon lamp (not shown), or the like, which emits heat rays such as infrared rays or far infrared rays including visible light depending on the light source, is provided in the center of heat ray fixing roller 17a. It is provided as heat ray irradiation means.

Heat ray fixing roller 17a and fixing roller 47a
The recording paper P is sandwiched by a nip portion N formed between
By applying heat and pressure, the color toner image on the recording paper P is fixed, and the recording paper P is sent by the paper discharge roller 18 and discharged to a tray on the upper portion of the apparatus.

The toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is transferred to a cleaning blade 19 provided in a cleaning device 19 as an image forming body cleaning means.
Cleaning is performed by a. The photosensitive drum 10 from which the residual toner has been removed is uniformly charged by the scorotron charger 11, and enters the next image forming cycle.

As shown in FIG. 2, the fixing device 17 includes a heat ray fixing roller 17 as a roll-shaped heat ray fixing rotating member having an upper elasticity for fixing a toner image on a transfer material.
a, and a lower fixing roller 47a as a roll-shaped fixing member that is paired with the upper heat ray fixing roller 17a, and is formed between the elastic heat ray fixing roller 17a and the fixing roller 47a. The recording paper P is sandwiched between the nip portions N having a width of about 5 to 20 mm, and the toner image on the recording paper P is fixed by applying heat and pressure. The hot-wire fixing roller 17a as a roll-shaped hot-wire fixing rotating member provided on the upper side has a fixing separation claw TR3, a cleaning roller TR1, a heat equalizing roller TR4 in the rotation direction of the hot-wire fixing roller 17a from the position of the nip portion N. An oil application roller TR2 is provided, and oil is applied to the heat ray fixing roller 17a by an oil application roller TR2 in which a felt member impregnated with oil is wound around a cylindrical aluminum pipe or a paper tube. The cleaning roller TR1 cleans toner and oil on the peripheral surface of the heat ray fixing roller 17a. Therefore, the heat equalizing roller TR4 and, as described later,
The temperature sensor TS1, which is a temperature detecting means for measuring the temperature of the heat ray fixing roller 17a, is provided on the peripheral surface of the cleaned heat ray fixing roller 17a between the cleaning roller TR1 and the oil application roller TR2. Fixing separation claw T
The transfer material after fixing is separated by R3. Further, a heat roller fixing roller 17 heated by the heat ray absorbing layer 171b by a heat roller uniforming roller TR4 using a metal roller member having good thermal conductivity such as aluminum or stainless steel, or a heat pipe.
The heat generation temperature distribution on the a peripheral surface is made uniform. The heat uniformizing roller TR4 is used to fix the heat ray fixing roller 17a when the transfer material is passed.
The temperature unevenness in the vertical and horizontal directions is uniformized.

A heat ray fixing roller 17a provided on the upper side and serving as a heat ray fixing rotating member for fixing a toner image on a transfer material includes a cylindrical light transmitting base 171a and an outer side of the light transmitting base 171a. (Transparent elastic layer 171d)
A heat-absorbing layer 171b and a release layer 171c are provided in this order, or as described in detail in FIG. 3 below, a cylindrical light-transmitting substrate 171a and an outer surface (outer peripheral surface) of the light-transmitting substrate 171a. ), The light-transmitting elastic layer 171d and the heat ray absorbing layer 1 on the outside (outer peripheral surface) of the light-transmitting elastic layer 171d.
Heat ray absorbing layer 17 in which release layer 171c is integrated with release layer 171c
1B are provided in that order, and are configured as soft rollers having an outer diameter of about 25 to 50 mm. Depending on the light source, a halogen lamp HLa or a xenon lamp (not shown) is provided in the center of the translucent substrate 171a as a heat ray irradiating means for emitting heat rays such as infrared rays or far infrared rays including visible light. Heat ray fixing roller 17a as rotating member for heat ray fixing
Is configured as a highly elastic soft roller as described later. The heat rays emitted from the halogen lamp HLa or the xenon lamp (not shown) are absorbed by the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) to form a roll-shaped rotating member for fixing a heat ray capable of rapid heating.

A fixing roller 47 serving as a lower roll-shaped fixing member that is paired with the upper heat ray fixing roller 17a.
a is a cylindrical metal pipe 471a made of, for example, an aluminum material, and a silicon material is used on the outer peripheral surface of the metal pipe 471a, for example, and the rubber hardness is 10Hs to 40Hs.
A rubber roller 471b composed of a thick rubber layer having a thickness (wall thickness) of 2 to 7 mm (JIS, A rubber hardness) was formed.
It is configured as a soft roller having an outer diameter of about 25 to 50 mm. An elastic rubber roller having high heat insulating property is used for the lower roll-shaped fixing member to prevent heat from diffusing from the upper heat ray fixing rotating member to the lower fixing member, and to secure a wide nip width. Further, a heat equalizing roller TR4 using a metal roller member having good thermal conductivity, such as an aluminum material or a stainless steel material, which rotates by being in contact with the surface of the rubber roller 471b.
Is provided, and the fixing roller 4 is fixed by the heat equalizing roller TR4.
The heat generation temperature distribution on the peripheral surface 7a is made uniform. As the heat equalizing roller TR4, it is preferable to use a heat pipe that has both heat storage and heat radiation. Further, a halogen lamp H as a heat source is provided in the center of the inside of the metal pipe 471a.
Lb may be provided. Of course, the same configuration as the upper heat ray fixing roller 17a of the present invention may be used for the lower fixing member.

A flat nip portion N is formed between the upper soft roller and the lower soft roller to fix the toner image.

TS1 is a temperature sensor which is mounted on the upper heat ray fixing roller 17a and is a temperature detecting means using, for example, a contact type thermistor for performing temperature control. TS2 is mounted on the lower fixing roller 47a. For example, a temperature sensor using a contact-type thermistor for performing temperature control. As the temperature sensors TS1 and TS2, non-contact type sensors can be used in addition to the contact type.

According to FIG. 3, the structure of the heat ray fixing roller 17a is shown.
As shown in the cross section in FIG.
As the base 171a, a thickness (thickness) of 1 to 5 mm is preferable.
1 to 4 mm thick, halogen lamp HLa or xeno
Heat from infrared or far infrared rays from lamps (not shown)
Pyrex® glass, safa
Ear (Al _TwoO_Three), CaF_TwoAnd other ceramic materials (heat conduction
Rate is (5-20) × 10^-3J / cm · s · K)
Used. Transparency using polyimide, polyamide, etc.
Light resin (thermal conductivity is (2-4) x 10^-3J / cm · s
-It is also possible to use K) or the like. As above, translucent
The thermal conductivity of the conductive substrate 171a is not so good.

The light-transmitting elastic layer 171d has a thickness (thickness).
A heat-ray-transmitting silicon rubber layer or a fluorine-containing rubber that transmits heat rays (infrared ray or visible ray including visible light depending on the light source) using 0.5 to 5 mm, preferably 1 to 4 mm thick silicon rubber or fluoro rubber. Layer (base layer)
Is formed. For the light-transmitting elastic layer 171d, in order to cope with a high speed, a method of improving the thermal conductivity by mixing a powder of a metal oxide such as silica, alumina or magnesium oxide as a filler into the base layer is adopted. Rate is (1
3) A silicon rubber layer or a fluorine rubber layer of about 10 ⁻³ J / cm · s · K is used. The silicon rubber layer and the fluorine rubber layer are made of a light-transmitting substrate 171a having a thermal conductivity of a glass member.
(Thermal conductivity is (5-20) × 10 ⁻³ J / cm · s · K)
Since it is lower, it acts as a heat insulating layer. When the thermal conductivity is increased, the rubber hardness generally tends to increase. For example, a rubber having a normal hardness of 40 Hs tends to have a hardness close to 60 Hs (JIS, A rubber hardness). Preferred rubber hardness is 10-5
0Hs. Translucent elastic layer 17 of rotating member for fixing heat rays
Most of 1d is occupied by this base layer, and the amount of compression during pressurization is determined by the rubber hardness of the base layer. The intermediate layer of the translucent elastic layer 171d is coated with a fluorine-based rubber, preferably with a thickness of 20 to 300 μm, as an oil-resistant layer to prevent oil swelling. The wavelength of the heat ray passing through the translucent elastic layer 171d is 0.1 to 20 μm, and preferably 0.3 to 3 μm. Therefore, the filler used as the hardness or thermal conductivity modifier described above is The average particle size including primary and secondary particles having a particle size of 、, preferably １ ／ or less, of the wavelength of the heat ray is 1 μm or less, preferably 0.1 μm.
Fine particles of metal oxides such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide and calcium carbonate having the following heat ray transmission properties (infrared ray or visible infrared ray including visible light depending on the light source) are used as the resin binder. The light-transmitting elastic layer 171d may be formed of a dispersed material. It is preferable that the average particle diameter including the primary and secondary particles in the layer is 1 μm or less, preferably 0.1 μm or less in order to prevent light scattering and reach the heat ray absorbing layer 171b. By providing the translucent elastic layer 171d, the heat ray fixing roller 17a as a heat ray fixing rotating member is configured as a soft elastic roller.

The heat ray absorbing layer 171b is emitted from a halogen lamp HLa or a xenon lamp (not shown).
The remaining heat rays absorbed by the light-transmitting base 171a and the light-transmitting elastic layer 171d are substantially 100% of the heat rays transmitted through the light-transmitting base 171a and the light-transmitting elastic layer 171d.
The carbon black, graphite, iron black (Fe ₃ O) is used in the resin binder so that the heat ray absorbing layer 171b absorbs about 100%, preferably 95% to 100% of the heat rays to form a heat ray fixing rotating member capable of rapid heating. ₄ ) and various ferrites and their compounds, copper oxide, cobalt oxide, red iron oxide (Fe ₂
O ₃₎ powder with a heat absorbing member obtained by mixing such a thickness 1
A heat ray absorbing member having a thickness of 0 to 500 μm, preferably 20 to 100 μm is formed on the outside (outer peripheral surface) of the translucent elastic layer 171d by spraying or coating. Heat ray absorbing layer 171b
Of the light-transmitting elastic layer 171d compared with the base layer (having a thermal conductivity of (1-10) × 10 ⁻³ J / cm · s · K) by adding an absorbent such as carbon black. (3-100) × 10 ⁻³ J / cm · s · K. As the heat ray absorbing layer 171b, a metal roller member such as a nickel electroformed roller may be provided with a similar thickness. At this time, it is preferable that the inside (the inner peripheral surface) is subjected to black oxidation treatment in order to absorb heat rays. Heat ray absorbing layer 17
The heat ray absorption rate at 1b is lower than about 90%, for example, 2
If it is about 0 to 80%, the heat rays leak, and when the heat ray fixing roller 17a as a heat ray fixing rotating member is used for monochrome image formation due to the leaked heat rays, the specific position of the heat ray fixing roller 17a is determined by filming or the like. When black toner adheres to the surface, heat is generated from the adhering part due to the leaked heat rays,
Heat generation due to heat ray absorption occurs again at that portion, and the heat ray absorption layer 171b is damaged. When used for color image formation, the color toner absorption efficiency is generally low,
In addition, since there is a difference in absorption efficiency between the color toners, a fixing failure or a fixing unevenness occurs. Therefore, the remaining heat rays emitted from the halogen lamp HLa or the xenon lamp (not shown) and absorbed by the light-transmitting base 171a and the light-transmitting elastic layer 171d form the light-transmitting base 171a and the light-transmitting elastic layer 171d. The heat ray absorption rate of the heat ray absorption layer 171b is about 100%, which is 90 to 100%, preferably 95 to 100%, so that the heat ray transmitted through the heat ray absorption layer 171b is completely absorbed by the heat ray absorption layer 171b.
100%. Thereby, the melting of the color toner, which is difficult to be fixed by the heat rays due to the difference in the spectral characteristics, is favorably performed. In particular, in the color image formation in FIG.
The superimposed color toner image on the transfer material having a thick toner layer, which is difficult to fix by heat rays due to the difference in spectral characteristics, is favorably fused. Further, when the thickness of the heat ray absorbing layer 171b is less than 10 μm and thin, the heating rate due to the absorption of the heat ray in the heat ray absorbing layer 171b is high, but the heat ray absorbing layer 171b is damaged by local heating by the thin film and the cause of the insufficient strength. When the thickness of the heat ray absorbing layer 171b exceeds 500 μm and is too thick, poor heat conduction or large heat capacity makes rapid heating difficult. Heat ray absorbing layer 171b
Of the heat ray absorption layer of the heat ray absorption layer 171b.
10 to 500 μm, preferably 20 to 100 μm
By setting m, local heat generation in the heat ray absorbing layer 171b is prevented, and uniform heat generation is performed. The wavelength of the heat ray projected on the heat ray absorbing layer 171b is 0.1 to 20 μm.
m, preferably 0.3 to 3 μm, so that a filler for adjusting hardness or thermal conductivity is added as a filler. 2
The average particle size including the secondary particles is 1 μm or less, preferably 0.1 μm or less.
Fine particles of metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. having a heat ray transmission of 1 μm or less (infrared ray or visible ray including visible light depending on the light source) are used as resin binder. 5 to 50% by mass dispersed in the heat ray absorbing layer 17
1b may be formed. This allows the heat rays to enter the heat ray absorbing layer 171b and prevent heat generation at the interface. In this way, the heat capacity of the heat ray absorbing layer 171b is reduced so that the temperature rises immediately. Therefore, the temperature of the heat ray fixing roller 17a as a heat ray fixing rotating member is lowered, and the fixing unevenness occurs. To prevent. As the heat ray absorbing layer 171b, carbon black, graphite, iron black (Fe ₃
O ₄₎ or ferrites and its compounds, copper oxide, cobalt oxide, may be used as the mixed powder, such as iron oxide (Fe ₂ O _3). As the heat ray absorbing layer 171b, a metal film member such as a nickel electroformed belt can be used. At this time, it is desirable that the inside (inner peripheral surface) be subjected to black oxidation treatment in order to absorb heat rays.

Further, a PFA (fluororesin) tube having a thickness of 20 to 100 μm is coated on the outer side (outer peripheral surface) of the heat ray absorbing layer 171b separately from the heat ray absorbing layer 171b in order to improve the releasability from the toner. Or fluorinated resin (PF
(A or PTFE) paint coated with 20 to 100 μm, or formed by molding silicon rubber or fluoro rubber with a layer thickness of 20 to 500 μm, and having a thermal conductivity of (3 to 100) × 10
A release layer 171c of ⁻³ J / cm · s · K is provided (separation type).

Further, as shown in the cross section in FIG.
Carbon black, graphite, iron black (Fe _ThreeO_Four) And various blowjobs
And its compounds, copper oxide, cobalt oxide, red iron oxide
(Fe_TwoO_Three) Etc.
Resin (PFA or PT)
FE) mixed with paint or silicone rubber or fluorine rubber
The heat ray absorbing layer 171 described above with reference to FIG.
b and the release layer 171c, and the heat ray absorbing layer 171b
Heat ray absorption having releasability integrally with release layer 171c
The layer 171B is formed on the outside (outer peripheral surface) of the light-transmitting substrate 171a.
Form outside (outer peripheral surface) of the formed translucent elastic layer 171d
To form an elastic roll-shaped rotating member for fixing heat rays.
Each embodiment, which will be described in detail later.
In the embodiment, the heat ray absorbing layer 1 described above is used as the heat ray absorbing layer.
Heat ray absorbing layer 17 in which release layer 171c is integrated with release layer 171c
1B. The heat ray absorbing layer 171b and the release layer
As the heat ray absorbing layer 171B integrating the 171c and 171c,
PFA (carbon powder) with a thickness of about 20 to 100 μm
-Fluoroalkoxy) tube is preferred
It is used well. Heat ray absorbing layer 171b and release layer described above
171c and the heat conductivity of the heat ray absorbing layer 171B integrated therewith
Is substantially the same as the thermal conductivity of the heat ray absorbing layer 171b,
0) × 10^-3J / cm · s · K. Same as above
And a halogen lamp HLa and a xenon lamp (not shown)
The light-transmitting substrate 171a and the light-transmitting elastic layer 17
1d, the remaining heat rays absorbed by the light-transmitting substrate 171a
And the heat rays transmitted through the translucent elastic layer 171d are completely absorbed
The heat ray absorption rate of the heat ray absorption layer 171B is set to about 10
90% to 100%, preferably 95 to 100%
%. 90% of heat ray absorption rate in heat ray absorption layer 171B
Lower than the temperature, for example, 20-80%
Is leaking, and the rotating heat-fixing member is
When used for black image formation, filming etc.
Black toner adheres to the surface of the heat ray fixing rotating member at a specific position
Then, heat is generated from the adhering part by the leaked heat rays, and that part
Heat generation due to heat ray absorption occurs again in minutes
Damage layer 171B. Also used for color image formation
The color toner absorption efficiency is generally low and
There is a difference in absorption efficiency between Lartner
Or uneven fixation. Therefore, the halogen lamp H
A translucent group emitted from a La or xenon lamp (not shown)
Remaining in the body 171a and the translucent elastic layer 171d.
The heat-transmitting light is applied to the light-transmitting substrate 171a and the light-transmitting elastic layer 17
Heat rays that have passed through 1d are completely absorbed in the heat ray fixing rotating member.
The heat ray absorption rate of the heat ray absorption layer 171B is set to about 1
90% to 100%, preferably 95 to 10%
0%. In addition, local emission in the heat ray absorbing layer 171B is performed.
Heat is also prevented and uniform heat is generated. Also, heat ray absorption
The wavelength of the heat ray projected on the layer 171B is 0.1 to 20 μm.
m, preferably 0.3 to 3 μm,
To adjust the hardness and thermal conductivity.
次, preferably １ ／ or less, of the line wavelength
The average particle size including the secondary particles is 1 μm or less, preferably 0.1 μm or less.
Heat ray transmission of 1 μm or less (including visible light depending on the light source)
Infrared or far infrared transmission) titanium oxide, aluminum oxide
Luminium, zinc oxide, silicon oxide, magnesium oxide
Particles of metal oxides such as calcium carbonate and calcium carbonate
To form the heat ray absorbing layer 171B
Is also good.

In each of the embodiments described later in detail, the heat ray absorbing layer 171 described above is used as the heat ray absorbing layer.
heat-absorbing layer 171B integrating b and release layer 171c
As the translucent substrate 171a, Pyrex glass (manufactured by Corning Inc., USA) and the translucent elastic layer 17 are used.
1d is made of transparent silicon rubber, and the heat ray absorbing layer 171B is made of PFA (perfluoroalkoxy).
The one in which a is formed is used as an example.

Pyrex glass (made by Corning Incorporated, USA) as the light-transmitting substrate 171a, transparent silicon rubber as the light-transmitting elastic layer 171d, and PF as the heat ray absorbing layer 171B.
Table 1 shows the physical properties (density (kg / m ³ ), specific heat (J / kg · K), and unit heat capacity (kJ / m ³ · K)) of each member of the heat ray fixing roller 17a using A (perfluoroalkoxy). And the absorptance when a halogen lamp HLa having a color temperature of 2250 K is used is as shown in Table 2.

[0052]

[Table 1]

[0053]

[Table 2]

According to FIG. 4, the heat ray absorbing layer 171 of the heat ray fixing roller 17a as a heat ray fixing rotating member in the form of a roll.
b (or the heat ray absorbing layer 171B), if the above-mentioned concentration distribution of the heat ray absorbing member is uniformly provided as shown by the dotted line (a-1), the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) is formed.
The heat generation distribution of B) is such that the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) at the boundary as shown by the curve (b-1).
The heat is concentrated in the light-transmitting elastic layer 171d.
(Or the heat ray absorbing layer 171B) is likely to lose heat to the side, so it is preferable to provide a concentration distribution and generate heat inside the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) from the viewpoint of dispersing the heat distribution. Therefore, as shown by the dotted line (a-2) in the concentration distribution of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B), the light transmitting elastic layer 1
The interface on the 71d side is made to have a low concentration, and is gradually inclined and raised toward the outer peripheral surface side, so as to be closer to the outer peripheral surface side (the heat ray absorbing layer 171b).
Saturation is such that the concentration is such that it absorbs 100% in the thickness t1 of the heat ray absorbing layer 171B (or about 1/2 to 3/5 from the side of the translucent elastic layer 171d). Thus, the heat generation distribution due to the absorption of the heat rays in the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) has a maximum value of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) as shown by the curve (b-2). Heat ray absorption layer 1 from interface
With respect to the thickness t1 of the heat ray absorbing layer 71b (or the heat ray absorbing layer 171B), the transition is made so as to be located about 1/3 to 2/5 from the side of the translucent elastic layer 171d. Even when the absorbing layer 171B is used, there is no influence even if the outer peripheral surface layer is shaved. Further, as shown by a dotted line (a-3), it is preferable to form a saturated layer by providing an inclination, whereby the heat ray absorbing layer 171b (or the heat ray absorbing layer 171) is formed as shown by a curve (b-3).
The heat generation distribution B) has a maximum value near the center of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B), and has a minimum value near the interface or the outer peripheral surface of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B). It is formed in a parabolic shape, and the influence of the scraping of the outer peripheral surface layer is small, and the influence of the outflow of heat is particularly prevented. In short, if the absorption is sufficiently performed inside, the influence of the concentration on the outside disappears. There is no influence of shaving. Further, it is also possible to provide the above-mentioned inclination in the concentration distribution and adjust the heat generation distribution by changing the inclination angle.

As shown in FIG. 5, the outer diameter φ of the cylindrical translucent substrate 171a of the heat ray fixing roller 17a as a roll-shaped heat ray fixing rotating member is 15 to 45 mm.
The thickness t is preferably thicker in terms of strength and thinner in terms of heat capacity. However, due to the relationship between strength and heat capacity, the outer thickness of the cylindrical translucent base 171a is large. Diameter φ
And the thickness (wall thickness) t is 0.02 ≦ t / φ ≦ 0.20, preferably 0.04 ≦ t / φ ≦ 0.10. When the outer diameter φ of the transparent substrate 171a is 40 mm, the thickness t of the transparent substrate 171a is 0.8 mm ≦ t ≦ 8 m.
m, preferably 1.6 mm ≦ t ≦ 4.0 mm. When t / φ is less than 0.02 in the translucent substrate 171a, the strength becomes insufficient, and when t / φ exceeds 0.20, the heat capacity increases and the heating of the heat ray fixing roller 17a is prolonged. Further, even if the translucent substrate 171a is used, it may absorb about 5 to 25% of heat rays depending on the material. Similarly, the translucent elastic layer 171d may have a thickness of 5 to 25 depending on the material.
% Of the heat ray may be absorbed, and it is preferable that the heat ray is thin as long as the strength can be maintained.

The use of the fixing device 17 described with reference to FIG. 2 makes it possible to provide a fixing device which is resistant to deformation at the fixing portion (nip portion) and capable of quick start (rapid heating). Due to the pressure in the soft fixing portion (nip portion) due to the elasticity of the member and the heating by the heat absorbing layer of the rotating member for fixing heat rays, the color toner which is difficult to fix by the heat rays due to different spectral characteristics. The melting is performed favorably, and quick start (rapid heating) fixing of the color toner becomes possible. Also, an energy saving effect can be obtained.

Embodiment 1 However, in the heat ray fixing rotating member of the fixing device, the temperature of the heat ray absorbing layer of the surface layer having a small heat capacity rises quickly,
Although the surface heat ray absorbing layer is hot, the temperature of the internal light-transmitting substrate and the light transmitting elastic layer rises slowly, and the heat of the surface layer is easily taken inside during warm-up or fixing, and the temperature of the surface heat ray absorbing layer becomes low. It becomes unstable or uneven.

In order to solve this, set conditions are set for the heat capacity (J / K) per unit heat capacity (kJ / m ³ · K) of each layer of the rotating member for heat ray fixing.

More specifically, the heat ray fixing rotation shown in FIG.
Unit heat capacity of each layer of the member (kJ / m ^Three・ K) is shown in Table 1.
The absorptance of each layer is as described above in Table 2.
Is a heat ray fixing roller 17a as a heat ray fixing rotating member.
The thickness of the translucent substrate 171a is 1.50 mm.
Use Pyrex glass with outer diameter of 28.00mm
The thickness of the light-transmitting elastic layer 171d is 1.00 mm.
And transparent silicon rubber with an outer diameter of 30.00 mm, heat absorbing
As the collecting layer 171B, the thickness (thickness) is 0.05 mm,
PFA with an outer diameter of 30.10 mm (perfluoroalkoxy)
350mm length (A-3 size vertical feed width)
(297 mm) width with a light-emitting part capable of fixing)
Halogen lamp H with temperature of 2250K and electric power of 760W
When La is used, the heat capacity (J / K) and the calorific value (J /
sec) and the calorific value per unit heat capacity are shown in Table 3 below.
As shown.

[0060]

[Table 3]

When the calorific value per unit heat capacity of two adjacent layers is compared, the calorific value per unit heat capacity of a layer closer to the surface layer is calculated by comparing the calorific value per unit heat capacity of the other layer adjacent to the inner layer. It is preferable that the heat generation amount per unit heat capacity of the surface layer is set to be larger than the heat generation amount.
It has been confirmed that it is preferable to set the heat generation amount to be larger than the heat generation amount per unit heat capacity of 1B.

From Table 1, when the heat value per unit heat capacity of the light-transmitting substrate 171a is 1, the light-transmitting elastic layer 171 is formed.
The heat value per unit heat capacity of d is about 1 to 5 times, and the heat value per unit heat capacity of the translucent elastic layer 171d is 1
Then, it is confirmed that the heat generation amount per unit heat capacity of the heat ray absorbing layer 171B is preferably set to about 20 to 60 times.

In the above description, the color temperature was measured at 2250 K, and the temperature rise of the heat ray fixing roller 17a was 31
In sec, the fixing temperature reaches 180 ° C., which is set as an appropriate fixing temperature. However, if the color temperature is raised to about 2500 K, which is the upper limit of the practical range, the wavelength of the halogen lamp HLa becomes short,
The surface layer has a higher absorption rate, the surface layer has a higher calorific value per unit heat capacity, and the time to reach 180 ° C. set as the proper fixing temperature is faster. 270 color temperature
When the temperature is set to about 0K, the time required to reach the proper fixing temperature is shortened, but the life of the halogen lamp HLa due to disconnection is shortened, which is not practical. Although the amount of heat generated per unit heat capacity of each layer changes depending on the color temperature, it is preferable that the setting conditions be set in the above ranges.

As described above, the controllability of the heat transfer of each layer is improved by setting the condition of the amount of heat generated per unit heat capacity of each layer of the rotatable member for heat ray fixing, so that the heat supplied from the heat ray irradiating means is reduced by the heat ray fixing means. It is possible to provide a fixing device in which the heat is transmitted without delay in each layer of the rotating member for heating, and the surface of the heat ray absorbing layer at the time of warming-up or fixing is stably and uniformly heated.

Embodiment 2 In the rotating member for fixing heat rays of the fixing device, the heat ray absorbing layer of the surface layer has a small heat capacity, the heat ray absorbing layer of the surface layer is hot, but has no heat storage. The temperature of the translucent elastic layer is low, the temperature drop of the heat ray absorbing layer on the surface of the rotating member for heat ray fixing is large when the transfer material is passed, and the fixability differs at the leading end and the trailing end of the transfer material. High image quality is not fixed. Further, the fixability differs between when a color image is formed and when a monochrome image is formed.

In order to solve this problem, the temperature control of the heat ray absorbing layer on the heat ray fixing rotating member surface layer for equalizing the fixability at the leading end and the trailing end of the transfer material when the transfer material passes. Do.

More specifically, normal temperature control for maintaining the heat ray fixing roller 17a as a heat ray fixing rotating member at a predetermined temperature (fixing appropriate temperature) when the recording paper P as a transfer material in FIG. 2 passes. Therefore, regardless of the temperature of the heat ray fixing roller 17a by the normal temperature control, the halogen lamp HLa as the heat ray irradiation means is forcibly operated.

The normal temperature control is a control for maintaining the heat ray fixing roller 17a at a proper fixing temperature in a standby state. Generally, the on-off control of the halogen lamp HLa is performed through a fixing control unit (not shown). For example, if the predetermined set temperature (fixing proper temperature) is 170 ° C., 16
The halogen lamp HLa is turned on and off so as to maintain the temperature of the heat ray fixing roller 17a at about 5 to 170 ° C. This is a so-called energy saving mode, and a lower set temperature may be used. On the other hand, when the recording paper P passes, the control is different from the normal temperature control, that is, the halogen lamp HLa is forcibly turned on (operated). 17a
Regardless of the temperature, the halogen lamp HLa is turned on through a fixing control unit (not shown) at the same time as the recording paper P passes.

The detection of the passage of the transfer material is performed, for example, by a paper detection provided at the rear of the timing roller 15b (see FIG. 1) constituting the paper passing path in the transfer material transport direction, which is generally used in an image forming apparatus. A sensor (not shown in FIG. 1), a jam detection sensor (not shown in FIG. 1) provided on the transfer material outlet side of the photosensitive drum 10, and a sensor for detecting the leading end of the transfer material (FIG. 1)
(Not shown). The timing at which the halogen lamp HLa is turned on (operating state) is estimated by the fixing controller (not shown) from the position of the sensor and the transfer speed of the transfer material to the time required for the fixing device 17 (see FIG. 1). To forcibly turn on (operate) the halogen lamp HLa.

As a specific experimental result, when forming a monochrome image on the heat ray fixing roller 17a using the halogen lamp HLa of 800 W power, the heat ray fixing roller 17a when the transfer material is passed with the halogen lamp HLa turned off is set. Table 4 shows a change in temperature between the fixing roller 47a and the fixing roller 47a, and Table 5 shows a change in temperature between the heat ray fixing roller 17a and the fixing roller 47a when the transfer material is passed while the halogen lamp HLa is forcibly turned on at 100%.

[0071]

[Table 4]

[0072]

[Table 5]

The temperature change of the heat ray fixing roller 17a when passing the transfer material with the halogen lamp HLa off was about 50 ° C. as shown in Table 4, and the transfer material was passed with the halogen lamp HLa turned on. The temperature change of the heat ray fixing roller 17a at this time is kept as small as about 20 ° C. as shown in Table 5.

As described above, when the temperature of the entire heat ray fixing roller 17a increases during continuous printing or the like, the halogen lamp HLa does not need to be turned on (operating state) even when the recording paper P passes. O Halogen lamp HLa
The temperature that does not need to be n is a case where the temperature is equal to or higher than a set temperature at the time of fixing (fixing proper temperature) + 20 ° C. If the temperature is higher than the set temperature + 20 ° C., normal fixing cannot be performed due to hot offset (high temperature offset). The power is 120
100% on by halogen lamp HLa of 0W
In the state, since the temperature of the heat ray fixing roller 17a is too high, the ON state is set at 80%.

As described above, when the transfer material is passed, the heat ray irradiating means is forcibly operated to prevent the temperature of the heat ray absorbing layer from being lowered at the time of passing the paper. It is possible to provide a fixing device having a uniform fixing property and performing high-quality fixing.

Further, when a color image is formed (in the case of fixing a color toner image), the glossiness changes when the fixing temperature changes. As for the variation width of the glossiness, the glossiness changes by about 8% when the fixing temperature is 20 ° C. From the viewpoint of image quality, the change in glossiness must be suppressed to 8 to 10%. For this reason,
It is preferable that the control is performed through a fixing control unit (not shown) so as to change the on ratio of the halogen lamp HLa when the transfer material passes between the color image formation and the monochrome image formation. As a result, it is possible to provide a fixing device that can stably perform high-quality fixing during monochrome image formation and color image formation. It is possible to provide a fixing device in which the fixing properties at the end portions are made uniform and high-quality fixing is performed.

Embodiment 3 In the rotary member for fixing heat rays of the fixing device, the responsiveness of the heat ray absorbing layer of the surface layer having a small heat capacity is good, and the heat ray absorbing layer of the surface layer is hot, but the internal light transmitting substrate and the transparent member are not responsive. The temperature of the photoelastic layer is low, and the temperature of the heat absorbing layer on the surface of the rotating member for heat ray fixing is stabilized and uniformized during continuous feeding of the transfer material, particularly in the horizontal direction (in the direction perpendicular to the transfer material feeding direction). Cannot be achieved, and stable high-quality image cannot be fixed.

In order to solve this problem, the temperature of the heat absorbing layer on the surface of the rotating member for fixing the heat rays during continuous feeding of the transfer material is stabilized and made uniform, particularly in the horizontal direction (perpendicular to the direction in which the transfer material is fed). With reference to FIG. 6 to FIG. 6 is a diagram showing the application of the external heating roller member to the fixing device of FIG. 2, FIG. 7 is a diagram showing a light emitting portion of the heat ray irradiation means of FIG. 6, and FIG. FIG. 6 is a diagram showing a temperature rise rate with and without a temperature change and a temperature change of a rotating member for heat ray fixing during printing.

According to FIG. 6 to FIG. 8, FIG.
As described above, the fixing device 17 includes a heat ray fixing roller 17a as a roll-shaped heat ray fixing rotating member having an upper elasticity for fixing a toner image on a transfer material, and an upper heat ray fixing roller 17a. And a lower fixing roller 47a as a pair of lower fixing members,
The heat-ray fixing roller 17a further provided on the upper side includes a cylindrical light-transmitting base 171a, and a light-transmitting elastic layer 171d and a heat-ray absorbing layer 17 on the outer side (outer peripheral surface) of the light-transmitting base 171a.
1b and a release layer 171c in that order, or a cylindrical light-transmitting base 171a, a light-transmitting elastic layer 171d on the outer side (outer peripheral surface) of the light-transmitting base 171a, and the light-transmitting base 171a. The heat ray absorbing layer 171b is provided on the outer side (outer peripheral surface) of the elastic layer 171d.
And a heat ray absorbing layer 171B integrally formed with the release layer 171c. The soft roller having an outer diameter of about 25 to 50 mm is provided.
A fixing roller 47a as a lower roll-shaped fixing member, which forms a pair, has a cylindrical metal pipe 471a and a rubber roller 471b formed of a thick rubber layer on the outer peripheral surface of the metal pipe 471a. And a soft roller having an outer diameter of about 25 to 50 mm.

The recording paper P is sandwiched by a nip portion N having a width of about 5 to 20 mm formed between the heat ray fixing roller 17a having elasticity and the fixing roller 47a, and heat and pressure are applied to the recording paper P. The upper toner image is fixed.

An external heating roller TR5 as an external heating roller member is provided on the upper side of the heat ray fixing roller 17a as a roll-shaped rotating member for heat ray fixing provided in place of the heat equalizing roller TR4 described above with reference to FIG. A fixing separation claw TR3, a cleaning roller TR1, an external heating roller TR5, and an oil application roller TR2 are provided in the rotation direction of the heat ray fixing roller 17a from the position of the nip portion N. The temperature sensor TS1, which is a temperature detecting means for measuring the temperature of the heat ray fixing roller 17a, is provided on the peripheral surface of the cleaned heat ray fixing roller 17a between the cleaning roller TR1 and the external heating roller TR5. Further, a heat equalizing roller TR4 is provided on the surface of the rubber roller 471b of the lower fixing roller 47a and abuts and is driven to rotate, and the heat uniformizing roller TR4 equalizes the heat generation temperature distribution on the peripheral surface of the fixing roller 47a. .

Inside the heat ray fixing roller 17a, a halogen lamp HLc and a halogen lamp H
Ld is provided, and a halogen lamp HLb is provided inside the fixing roller 47a as necessary. As shown in FIG. 7, the halogen lamp HLc inside the heat ray fixing roller 17a is 4 size vertical feed width (210mm)
In the halogen lamp HLd, the light emitting units are provided outside both ends of the position corresponding to the light emitting unit of the halogen lamp HLc. When fixing the toner image on the recording paper P of the A-4 size vertical feed, only the halogen lamp HLc is turned on, and the recording is performed by the A-4 size horizontal feed (297 mm) or the A-3 size vertical feed (297 mm). At the time of fixing the toner image on the paper P, the halogen lamp HLd is also turned on and A-3
The fixing width of the size vertical feeding width (297 mm) is secured. Accordingly, when one heat ray irradiation unit having a light emitting portion having a normal A-3 size vertical feed width (297 mm) is used, A
Excessive temperature rise at both ends of the heat ray fixing roller 17a, which is caused when fixing the toner image on the recording paper P of -4 size vertical feed (210 mm width) is prevented, and deterioration of the heat ray fixing roller 17a is prevented.

The external heating roller TR5 rotated in contact with the heat ray fixing roller 17a has a thickness (thickness) of 1 to 3 mm.
The outer diameter of the external heating roller TR5 is about 1/3 to 2/3 of the outer diameter of the heat ray fixing roller 17a, and the diameter is smaller and thicker. For example, the external heating roller TR5 is constituted by a metal pipe having no good heat conductivity using an aluminum material or the like (no reference numeral). Inside the external heating roller TR5, there is provided a halogen lamp HLe as a heat ray irradiating means having a light emitting portion having an A-3 size vertical feeding width (297 mm). An external heating roller T having a halogen lamp HLe to be turned on inside, having a low thermal conductivity, and capable of responsiveness (immediate temperature rise) with low power.
By R5, the temperature drop of the heat ray fixing roller 17a and the non-uniformity of the temperature difference in the lateral direction (the direction orthogonal to the transfer material feeding direction) caused by the passage of the recording paper P are suppressed.

Therefore, specifically, the heat ray fixing roller 1
The ratio (%) of the heat capacity Q2 (J / K) of the external heating roller TR5 to the heat capacity Q1 (J / K) of FIG.
Preferably, it is set to 0% ((Q2 / Q1) × 10
0 = 10-30). If the ratio Q2 / Q1 is less than 10% and the heat capacity of the external heating roller TR5 is small, the heat supply capability of the external heating roller TR5 during paper passing is insufficient, and the heat capacity in the horizontal direction (the direction orthogonal to the transfer material feeding direction) is insufficient. Heat is not equalized. If the ratio Q2 / Q1 exceeds 30% and the heat capacity of the external heating roller TR5 is too large, the external heating roller T5
No responsive temperature rise of R5.

Further, when the halogen lamp HLb of the fixing roller 47a is not provided and the power used for the fixing device 17 is about 1000 to 1200 W in total, for example, the halogen lamp HLc and the halogen lamp HLd of the heat ray fixing roller 17a are used. And about 800 W is used as the total power of the halogen lamp H of the external heating roller TR5.
As the power of Le, about 300 W is used, and the ratio (%) of the power distribution of the external heating roller TR5 to the heat ray fixing roller 17a is set to 20 to 50% (the heat ray fixing roller 17a).
a for the full lighting of the halogen lamps HLc and HLd a). Power distribution ratio is 20%
If the electric power of the external heating roller TR5 is too small, the heat of the heat ray fixing roller 17a in the lateral direction (the direction orthogonal to the transfer material feeding direction) cannot be uniformed by the external heating roller TR5. On the other hand, if the power distribution ratio exceeds 50% and the power of the external heating roller TR5 is too large, proper power distribution of the heat ray fixing roller 17a cannot be performed.

As for the heating rate defined by the heat capacity and the power distribution, the ratio of the heating rate of the external heating roller TR5 to the hot-wire fixing roller 17a is about 2 to 5 times. As shown by curve (a) in FIG. 8, the speed and the temperature curve at the time of printing are immediately raised to the proper fixing temperature Tc and kept constant, and the heat ray fixing roller 17a heated by the external heating roller TR5 is , FIG.
As shown in the curve (b), printing is possible when the temperature reaches the approximate proper fixing temperature Tc, the temperature drop during printing is small, the overshoot after printing is small, and the horizontal direction (transfer of the transfer material). (In the direction perpendicular to the direction), heat is kept uniform, and good fixing is always possible.
If the external heating roller TR5 is not provided, the proper fixing temperature T
At the time of printing after the temperature rise to c, as shown by the curve (c) in FIG. 8, the temperature drop is large, the overshoot after printing is large, and the horizontal direction (the direction orthogonal to the transfer material feeding direction). Does not keep the heat uniform and tends to cause poor fixing.

As described above, by arranging the external heating roller member, the temperature of the heat ray absorbing layer on the surface layer of the rotating member for fixing the heat ray during continuous feeding of the transfer material can be stabilized and made uniform, particularly in the horizontal direction (transfer material). (Direction perpendicular to the feed direction) can be provided.

[0088]

According to the first to fourth aspects, the controllability of the heat transfer of each layer is improved by setting the condition of the heat generation amount per unit heat capacity of each layer of the rotating member for fixing the heat ray, and the heat is supplied from the heat ray irradiation means. The transferred heat is transmitted without delay in each layer of the rotating member for heat ray fixing, and it is possible to provide a fixing device that performs stable and uniform heating in the surface heat ray absorbing layer at the time of warming up and fixing. Becomes

According to the fifth aspect, when the transfer material is passed, the heat ray irradiating means is forcibly operated to prevent the temperature of the heat ray absorbing layer from dropping when the transfer material is passed. It is possible to provide a fixing device in which the fixing properties at the end portions are made uniform and high-quality fixing is performed.

According to the sixth aspect, it is possible to provide a fixing device that stably performs high-quality fixing when forming a monochrome image or a color image.

According to the seventh to ninth aspects, the provision of the external heating roller member stabilizes and equalizes the temperature of the heat ray absorbing layer on the surface layer of the heat ray fixing rotating member when the transfer material is continuously passed.
In particular, it is possible to provide a fixing device in which the temperature is made uniform in the lateral direction (the direction orthogonal to the transfer material feeding direction).

[Brief description of the drawings]

FIG. 1 is a sectional view of a color image forming apparatus showing an embodiment of an image forming apparatus using a fixing device according to the present invention.

FIG. 2 is an explanatory diagram illustrating a structure of a fixing device.

FIG. 3 is an enlarged cross-sectional configuration view of a roll-shaped rotatable member for fixing heat rays in FIG.

4 is a diagram showing a concentration distribution of a heat ray absorbing layer of the roll-shaped heat ray fixing rotating member of FIG. 2;

FIG. 5 is a view showing the outer diameter and thickness of a light-transmitting substrate of the roll-shaped rotating member for heat ray fixing of FIG. 2;

FIG. 6 is a diagram illustrating an application of an external heating roller member to the fixing device of FIG. 2;

FIG. 7 is a view showing a light emitting unit of the heat ray irradiation means of FIG. 6;

FIG. 8 is a diagram showing a temperature rise rate with and without an external heating roller member and a temperature change of a hot-wire fixing rotating member during printing.

[Explanation of symbols]

Reference Signs List 10 photoconductor drum 11 scorotron charger 12 exposure optical system 13 developing device 17 fixing device 17a heat ray fixing roller 47a fixing roller 171a light transmitting substrate 171b, 171B heat ray absorbing layer 171c release layer 171d light transmitting elastic layer HLa, HLb HLc, HLd, HLe Halogen lamp P Recording paper TR5 External heating roller

Claims (9)

[Claims] 1. A cylindrical light-transmitting base having a heat-ray irradiating means for emitting heat rays therein and having a light-transmitting property with respect to the heat rays, and a light-transmitting means for transmitting the heat rays outside the light-transmitting base. A cylindrical light-transmitting elastic layer having optical properties, and a heat-ray absorbing layer for absorbing the heat rays provided outside the light-transmitting elastic layer to form a roll-shaped heat ray fixing rotating member, and In a fixing device that fixes the toner image to the transfer material by heating and pressurizing, when the calorific value per unit heat capacity of two adjacent layers is compared, the calorific value per unit heat capacity of a layer closer to the surface layer is Is better
A fixing device, wherein the heat generation amount per unit heat capacity of the other layer adjacent to the inside is larger than that of the other layer. 2. The fixing device according to claim 1, wherein a calorific value per unit heat capacity of the surface layer is larger than a calorific value per unit heat capacity other than the surface layer. 3. The heat generation amount per unit heat capacity of the translucent elastic layer is 1 to 5, wherein the heat generation amount per unit heat capacity of the translucent substrate is 1.
Or the fixing device according to item 2. 4. The heat generation amount per unit heat capacity of the heat ray absorbing layer is 20 to 60, wherein the heat generation amount per unit heat capacity of the translucent elastic layer is 1. 3. The fixing device according to item 2. 5. A cylindrical light-transmitting base having a heat-ray irradiating means for emitting heat rays therein and having a light-transmitting property with respect to said heat rays, and a light-transmitting means for transmitting said heat rays outside said light-transmitting base. A cylindrical light-transmitting elastic layer having optical properties, and a heat-ray absorbing layer for absorbing the heat rays provided outside the light-transmitting elastic layer to form a roll-shaped heat ray fixing rotating member, and A fixing device for fixing the toner image to the transfer material by heating and pressurizing, wherein, when the transfer material passes, a normal temperature control for maintaining the heat ray fixing rotating member at a predetermined temperature; Wherein the heat ray irradiating means is operated irrespective of the normal temperature control of the rotating member. 6. A different temperature control is performed between when a monochrome image is formed and when a color image is formed.
3. The fixing device according to claim 1. 7. A cylindrical light-transmitting substrate having a heat-ray irradiating means for emitting heat rays therein and having a light-transmitting property with respect to said heat rays, and a light-transmitting means for transmitting said heat rays outside said light-transmitting base. A cylindrical light-transmitting elastic layer having optical properties, and a heat-ray absorbing layer for absorbing the heat rays provided outside the light-transmitting elastic layer to form a roll-shaped heat ray fixing rotating member, and A fixing device for fixing the toner image to the transfer material by heating and pressurizing, wherein an external heating roller member is provided to be in contact with the hot-wire fixing rotating member, and the external heating roller member with respect to the hot-wire fixing rotating member is provided. A fixing device having a heat capacity ratio (%) of 10 to 30%. 8. A ratio (%) of power distribution of the external heating roller member to the heat ray fixing rotating member is set to 20 to 50.
%. 9. The fixing device according to claim 7, wherein a ratio of a temperature rising speed of the external heating roller member to the heat ray fixing rotating member is 2 to 5 times.