JP2000305391A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device preventing a fixing irregularity by forming a heat ray fixing rotating member excellent in cylindrical accuracy. SOLUTION: In this device, a roll type heat ray fixing rotating member is formed by providing it with a heat ray irradiation means emitting a heat ray, a cylindrical heat ray tranmissive base substance 171a disposed centering around the heat ray irradiation means and having heat ray transmissivity to the heat ray, a heat ray transmissive elastic layer 171d on the outside of the base substance 171a and a heat ray absorbing layer 171b absorbing the heat ray on the outside of the layer 171d. In such a case, the thickness of the layer 171d is set to be three times or more as thick as that with respect to the circularity of the outer peripheral cylinder of the base substance 171a.

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, and a facsimile, 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 heat roller fixing method has been used as a fixing device having high technical perfection and stability. Machine to full-color machine,
Has been widely adopted.

However, in a conventional heat roller fixing type fixing device, it is necessary to heat a fixing heat roller having a large heat capacity when heating a transfer material or toner. And also
There is a problem that it takes time to warm up the fixing device during printing, and the printing time (warming-up time) becomes longer.

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 a quick start that saves energy and requires 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. In addition, a light 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 light from a halogen lamp (heat ray irradiation means) provided inside the cylindrical light transmitting substrate is provided. JP-A-59-6 discloses a fixing method in which light is absorbed by a light absorbing layer provided on the outer peripheral surface of a translucent substrate, and the toner image is fixed by heat of the light absorbing layer.
No. 5867 discloses this.

[0006]

However, a method of irradiating a heat ray from a halogen lamp (heat ray irradiating means) through a light-transmitting substrate and heating and fixing the toner disclosed in Japanese Patent Application Laid-Open No. 52-106741. And JP-A-59-
No. 65867, a light absorbing layer (heat ray absorbing layer) is provided on the outer peripheral surface of a translucent substrate to constitute a heat ray fixing roller (rotating member for heat ray fixing), and a heat ray from a halogen lamp (heat ray irradiating means). Is applied to the light absorbing layer through the light transmitting substrate, and the toner is fixed by the heat of the light absorbing layer, etc., although energy saving and a quick start in which the warm-up time is shortened are achieved. Since a cylindrical glass member is mainly used as the material, the cylindrical precision (roundness and cylindricity of the outer peripheral cylinder) of the light-transmitting substrate is poor, and the pressing force and rotation of the heat ray fixing rotating member become uneven. This causes a problem that fixing unevenness is likely to occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing device which solves the above-mentioned problems, forms a rotating member for fixing a heat ray with good cylindrical accuracy, and prevents uneven fixing.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing, wherein the heat ray radiating means emits heat rays; A cylindrical light-transmitting base that is disposed as a center and has a light-transmitting property with respect to the heat ray, a light-transmitting elastic layer outside the light-transmitting base, and the heat ray outside the elastic layer. A heat ray absorbing rotating layer for absorbing light is provided to form a rotating member for fixing a heat ray in a roll, and the thickness of the elastic layer is three times or more the roundness of the outer peripheral cylinder of the light-transmitting substrate. This is achieved by a fixing device.

[0009]

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. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope.

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, and FIG. 2 is a side cross-sectional view of the image forming body of FIG. FIG. 3 is an explanatory view showing the structure of the fixing device. FIG. 4 is an enlarged cross-sectional configuration diagram of the roll-shaped hot-wire fixing rotating member of FIG.
FIG. 6 is a diagram showing a concentration distribution of a heat ray absorbing layer of the roll-shaped heat ray fixing rotating member of FIG. 3, and FIG. 6 is a diagram showing an average outer diameter of a light transmitting substrate of the roll shaped heat ray fixing rotating member of FIG. FIG. 5 is a diagram showing the average thickness and the average thickness.

According to FIG. 1 or FIG. 2, a photosensitive drum 10, which is an image forming member, is provided on the outer periphery of a cylindrical base formed of a light-transmitting member such as glass or light-transmitting acrylic resin. A photoconductive layer and a photoconductor layer of an organic photosensitive layer (OPC) are formed. 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).
0 is rotated.

The photosensitive drum 10 is sandwiched between a front flange 10a and a rear flange 10b, and the front flange 10a is supported by a guide pin 10P1 provided on a cover 503 attached to a front side plate 501 of the apparatus main body.
The rear flange 10b is externally fitted to a plurality of guide rollers 10R attached to the rear plate 502 of the apparatus main body, and the photosensitive drum 10 is held. A gear 10G provided on the outer periphery of the rear flange 10b is meshed with a driving gear G1, and the photosensitive drum 10 is rotated clockwise as shown by an arrow in FIG. 1 with the transparent conductive layer grounded by its power. You.

According to the present invention, in the photoconductor layer of the photosensitive drum, which is the image forming point of the exposure beam for image exposure, an appropriate contrast is provided to the light attenuation characteristic (photocarrier generation) of the photoconductor layer. It is sufficient that the exposure light amount has a wavelength that can be obtained. Therefore, the light transmittance of the light-transmitting substrate of the photosensitive drum in the present embodiment does not need to be 100%, but may be such that a certain amount of light is absorbed when the exposure beam is transmitted. Should just provide an appropriate contrast. Acrylic resin,
In particular, those polymerized using methacrylic acid methyl ester monomer are preferably used because they are excellent in light transmission, strength, accuracy, surface properties, etc., but are used for other general optical members such as acrylic, fluorine, polyester, polycarbonate, Various translucent resins such as polyethylene terephthalate 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 (ITO), tin oxide, lead oxide, indium oxide, copper iodide, Au, Ag, N
A light-transmissive metal thin film made of i, Al, or the like is used. As a film forming method, a vacuum deposition method, an active reactive deposition method,
Various sputtering methods, various CVD methods, dip coating methods, spray coating methods, and the like are used. Various organic photosensitive layers (OPC) are used as the photoconductor layer.

The organic photosensitive layer as a photoconductive photoreceptor 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 contains a binder resin.

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 used for an image forming process of each color of yellow (Y), magenta (M), cyan (C) and black (K). 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.

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 has 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. Rear plate 5 of the device body
02 and the front side plate 501.
Guide pin 1 provided on cover 503 attached to
0P1 and a cylindrical holding member 2 fixed with the guide as a guide
At 0, the exposure optical system 12 for each color is attached and housed inside the base of the photosensitive drum 10. In addition, as the exposure element, a linear element in which a plurality of light emitting elements such as FL (phosphor emission), EL (electroluminescence), and PL (plasma discharge) are arranged in an array is used.

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

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 forms an image on a 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, a black (K) two-component (or one-component) developer is accommodated, and each has a thickness of, for example, 0.5 mm to 1 m.
The developing sleeve 131 is a cylindrical, non-magnetic stainless steel or aluminum material having an outer diameter of 15 to 25 mm.

In the developing area, the developing sleeve 131 is kept out of contact with the photosensitive drum 10 by a contact roller (not shown) with a predetermined gap, for example, 100 μm to 1000 μm, and the rotation of the photosensitive drum 10 is maintained. And a DC voltage of the same polarity as the toner (in this embodiment, a negative polarity) or a voltage that superimposes the AC voltage AC on the DC voltage is applied to the developing sleeve 131 as a developing bias. As a result, 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 unit 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 a negative polarity).

A gear 10 provided on the rear flange 10b of the photosensitive drum 10 through a driving gear G1 by starting a photosensitive member driving motor (not shown) at the start of image formation.
G is rotated to rotate the photosensitive drum 10 clockwise as indicated by the arrow in FIG. 1, and at the same time, the application of the potential to the photosensitive drum 10 is started by the charging action of the Y scorotron charger 11. After a potential is applied to the photosensitive drum 10, exposure by an electrical signal corresponding to the first color signal, that is, the Y image data is started in the Y exposure optical system 12, and the photosensitive layer on the surface thereof is rotated by rotating the drum. An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed. 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 is performed using an electrical signal corresponding to the second color signal of m, i.e., magenta (M) image data.
Yellow (Y) by non-contact reversal development
A toner image of magenta (M) is formed on the toner image of FIG.

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 device 13, and the K scorotron charger 11 is also provided. , 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 photosensitive drum 10 by the C and K exposure optical systems 12 is performed from the inside of the photosensitive drum 10 through a translucent substrate. 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 10
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 roll-shaped fixing roller 17a serving as a hot-roll fixing rotary member for fixing a color toner image, and a lower fixing roller 47a serving as a lower roll-shaped fixing rotary member. A halogen lamp 171g or a xenon lamp (not shown) that emits heat rays such as infrared rays or far-infrared rays including visible light depending on the light source is disposed as heat ray irradiating means inside the heat ray fixing roller 17a. .

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 fed by the paper discharge rollers 18 and discharged to a tray on the upper part 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. 3, a 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.
and a nip portion having a width of about 5 to 20 mm, formed between the hot-wire fixing roller 17a having elasticity and the fixing roller 47a. N fixes the recording paper P and applies heat and pressure to fix the toner image on the recording paper P. The heat-fixing roller 17a, which is a roll-shaped heat-fixing rotary member provided on the upper side, has a fixing separation claw TR6, a fixing oil cleaning roller TR1, and a heat equalizer in the rotation direction of the hot-wire fixing roller 17a from the position of the nip portion N. A roller TR7, an oil-applied felt TR2, and an oil amount regulating blade TR3 are provided, and an oil-applied felt TR is passed through a capillary pipe TR5 from an oil tank TR4.
2 is applied to the heat ray fixing roller 17a by the oil application felt TR2. The oil on the peripheral surface of the heat ray fixing roller 17a is cleaned by the fixing oil cleaning blade TR1. Accordingly, a temperature sensor TS1 which is a temperature detecting means for measuring the temperature of the heat equalizing roller TR7 and a heat ray fixing roller 17a, which will be described later.
Is provided on the peripheral surface of the heat ray fixing roller 17a which is cleaned between the fixing oil cleaning roller TR1 and the oil application felt TR2. The transfer material after fixing is separated by the fixing separation claw TR6. Further, the heat generation temperature distribution on the peripheral surface of the heat ray fixing roller 17a, which is heated by the heat ray absorption layer 171b by the heat equalizing roller TR7 using a metal roller member having good thermal conductivity such as aluminum or stainless steel, or a heat pipe using a heat pipe, is uniform. Be transformed into The heat uniformizing roller TR7 equalizes the temperature unevenness of the heat ray fixing roller 17a in the vertical and horizontal directions due to the passage of the transfer material.

A heat ray fixing roller 17a as a heat ray fixing rotating member for fixing a toner image on a transfer material has a cylindrical light transmitting substrate 171a and an outer (outer peripheral surface) of the light transmitting substrate 171a. Translucent elastic layer 171d and heat ray absorbing layer 1
It is configured as a soft roller provided with a release layer 71b and a release layer 171c in that order. Depending on the light source, a halogen lamp 171g or a xenon lamp (not shown) that emits heat rays such as infrared rays or far-infrared rays including visible light depending on the light source is disposed inside the translucent substrate 171a as heat ray irradiation means. The heat ray fixing roller 17a as a heat ray fixing rotating member is configured as a highly elastic soft roller as described later. A heat ray emitted from a halogen lamp 171g or a xenon lamp (not shown) is absorbed by the heat ray absorbing layer 171b to form a roll-shaped heat ray fixing rotating member capable of quick heating (quick start).

Further, the lower fixing roller 47a as a roll-shaped fixing rotating member has a cylindrical metal pipe 471a made of, for example, an aluminum material and a silicon material made of, for example, a silicon material on the outer peripheral surface of the metal pipe 471a. , A soft roller having a rubber roller 471b formed of a thin rubber layer having a thickness of 1 to 3 mm. An elastic rubber roller with high heat insulation is used for the lower roll-shaped fixing rotating member to prevent diffusion of heat from the upper heat ray fixing rotating member to the lower fixing rotating member, and to secure a wide nip width. I do. Further, a heat uniform roller TR7 using a heat roller or a metal roller member having good thermal conductivity, such as an aluminum material or a stainless steel material, which is in contact with the surface of the rubber roller 471b and is driven to rotate, is provided. Fixing roller 47a by TR7
The heat generation temperature distribution on the peripheral surface is made uniform. Heat uniformizing roller T
As R7, it is preferable to use a heat pipe having both heat storage and heat dissipation. Furthermore, a metal pipe 471a
May be provided with a halogen lamp 471c as a heat source. Of course, the same configuration as the upper (front side) heat ray fixing roller 17a of the present invention may be used for the lower (rear side) fixing rotating member.

A flat nip N is formed between the upper soft roller and the lower soft roller, and the toner image is fixed.

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 controlling the temperature. 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, a non-contact type sensor can be used in addition to a contact type sensor.

According to FIG. 4, the configuration of the heat ray fixing roller 17a is, as shown in the cross section in FIG. 4 (a), a thickness of the cylindrical light transmitting substrate 171a of 1 to 40 mm, preferably 2 to 40 mm. A halogen lamp 17 having a thickness of 5 mm and emitting heat rays such as infrared rays or far infrared rays including visible light depending on the light source.
Pyrex glass, sapphire (Al ₂ O ₃ ), CaF that transmits heat rays from 1 g or a xenon lamp (not shown)
₂ etc. ceramic material (thermal conductivity is (5-20) × 10 ^-3
J / cm · s · K, specific heat (0.5-2.0) × J / g
K, a specific gravity of 1.5 to 3.0) is mainly used, and a translucent resin using polyimide, polyamide, or the like (having a thermal conductivity of (2 to 4) × 10 ⁻³ J / cm · s · K , The specific heat is (1
2) × J / g · K, specific gravity of 0.8 to 1.2) are also used. For example, the translucent substrate 171 of the heat ray fixing roller 17a
As a, Pyrex glass having an inner diameter of 32 mm, an outer diameter of 40 mm, and a layer thickness (thickness) of 4 mm (specific heat is 0.78 J /
g · K, specific gravity 2.32)
The heat capacity Q1 per A-3 size width (297 mm) of 71a is about 60 cal / deg. The wavelength of the heat ray passing through the translucent substrate 171a is 0.1 to 20 μm.
m, preferably 0.3 to 3 μm, so that a filler for adjusting the hardness and thermal conductivity is added as a filler, but the particle size is １ ／, preferably １ ／ or less, of the wavelength of the hot wire. 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 ITO, titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. having a heat ray transmission of 1 μm or less (infrared or far infrared transmission including visible light depending on the light source). A light-transmitting substrate 171a dispersed in a resin binder
May be formed. 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. As described above, the translucent substrate 171a does not have good thermal conductivity. Further, since a cylindrical glass member (ceramic material) is mainly used as a material of the light-transmitting substrate 171a, the cylindrical accuracy (roundness and cylindricity of the outer peripheral cylinder) of the light-transmitting substrate 171a is poor (see FIG. 3), the variation in roundness and cylindricity of the outer peripheral cylinder is usually 0.1 mm or more,
The pressing force and rotation of the light-transmitting substrate 171a are not uniform, and fixing unevenness is apt to occur. This is not a usable state, and it is necessary to absorb the unevenness.
The thickness is three times or more the roundness of the outer peripheral cylinder of the light-transmitting substrate 171a. Thereby, the above problem can be solved. Further, it is preferable that the roundness of the outer peripheral cylinder of the light-transmitting substrate 171a be suppressed to 0.8 mm or less. The cylindricity is also preferably suppressed to 0.8 mm or less.
If the roundness or cylindricity of the outer peripheral cylinder exceeds 0.8 mm, unevenness in fixing cannot be absorbed even with the elastic layer 171d.

As described above, since a cylindrical glass member (ceramic material) is mainly used as a material of the light-transmitting substrate 171a, the cylindrical accuracy (circularity of the outer peripheral cylinder and the cylindrical shape) of the light-transmitting substrate 171a are determined. (See FIG. 3), the pressing force and the rotation are non-uniform, and uneven fixing is likely to occur. Therefore, a light-transmitting elastic layer 171d is provided on the outer peripheral surface of the light-transmitting substrate 171a.
The translucent elastic layer 171d provided on the outer peripheral surface of the translucent substrate 171a covers the elastic layer 171 so as to cover the roundness and the cylindricity of the outer peripheral cylinder of the translucent substrate 171a.
It is desirable that the layer thickness d is at least three times the roundness or cylindricity of the outer peripheral cylinder of the light-transmitting substrate 171a, and the thickness (layer thickness)
Is preferably 1 mm or more and 10 mm or less, more preferably 2 to 5 mm in thickness. For example, heat ray transmission (infrared ray including visible light or far infrared ray depending on the light source) using silicon rubber or fluorine rubber is transmitted. It is formed of a (light) rubber layer (base layer). If the thickness of the elastic layer 171d is less than 1 mm, uneven fixing cannot be absorbed. If it exceeds 10 mm, the fixing unevenness can be absorbed, but the heat capacity becomes large and the warm-up time becomes too long. In addition, although the elastic layer 171d is translucent, heat rays do not reach the heat ray absorbing layer 171b due to light absorption (heat ray absorption) by the elastic layer 171d. Elastic layer 17
In forming 1d, a light-transmitting substrate 171a is placed in a centered state, a rubber liquid is injected into the outside (outer peripheral surface), and then the light-transmitting substrate 171a is crosslinked to form a light-transmitting elastic layer 171d. However, it is preferable because particularly high outer diameter accuracy (roundness or cylindricity of the outer peripheral cylinder) can be obtained. In this manner, the light-transmitting elastic layer 171d having high cylindrical accuracy such as roundness or cylindricity of the outer peripheral cylinder is formed on the outer side (outer peripheral surface) of the translucent base 171a. At this time, as described later, the light-transmitting elastic layer 171d is made to absorb heat rays, and
71d may have both a light-transmitting property and a heat-absorbing property with respect to a heat ray. In this case, a heat-ray absorbing layer 171b is further provided from the outside (outer peripheral surface) of the light-transmitting elastic layer 171d by coating or a tube. It has a three-layer structure. In order to cope with high speed, a method for improving the thermal conductivity by blending a powder of a metal oxide such as silica, alumina, or magnesium oxide as a filler with the base layer (silicon rubber) for the light-transmitting elastic layer 171d is to cope with high speed. And the thermal conductivity is (1
~ 3) × 10 ^-3 J / cm · s · K, specific heat is (1-2) ×
A rubber layer having J / g · K and a specific gravity of 0.9 to 1.0 is used.
For example, the translucent elastic layer 171d of the heat ray fixing roller 17a
The A-3 size width of the elastic layer 171d when using a silicone rubber having an outer diameter of 50 mm and a layer thickness (thickness) of 5 mm (specific heat is 1.1 J / g · K, specific gravity is 0.91) (297)
The heat capacity Q2 per mm) is about 50 cal / deg. The rubber layer is made of a light-transmitting substrate using a glass member having a thermal conductivity of (5-20) × 10 ⁻³ J / cm · s ·
Since it is an order of magnitude lower than K), it functions as a layer having heat insulating properties.
When the thermal conductivity is increased, the rubber hardness generally tends to increase. For example, a rubber having a hardness of 40 Hs usually has a hardness of 60 Hs (JIS,
A rubber hardness). Preferred rubber hardness is 5 to 60 Hs. Most of the elastic layer 171d of the heat ray fixing rotating member is occupied by this base layer.
The amount of compression during pressurization is determined by the rubber hardness of the base layer. The intermediate layer of the elastic layer 171d is coated with a fluorine-based rubber having a thickness of 20 to 300 μm as an oil-resistant layer to prevent oil swelling. As the silicon rubber of the top layer of the elastic layer 171d, HTV (High Temperature V) is used.
RTV (R
oom Temperature Volcanizi
ng) or LTV (Low Temperature V)
olcanizing is coated with a thickness similar to that of the intermediate layer. Further, since the wavelength of the heat ray passing through the elastic layer 171d is 0.1 to 20 μm, preferably 0.3 to 3 μm, as a modifier for hardness and thermal conductivity, the particle diameter is 粒径 of the wavelength of the heat ray, Heat ray transmittance of preferably 1/5 or less, including primary and secondary particles and having an average particle size of 1 μm or less, preferably 0.1 μm or less (infrared or far-infrared transmittance including visible light depending on the light source). The elastic layer 171d may be formed by dispersing metal oxide fine particles such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, and calcium carbonate in a resin binder. 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. Elastic layer 17
By providing 1d, the heat ray fixing roller 17a as a heat ray fixing rotating member is configured as a soft roller having high elasticity. As the elastic layer 171d, carbon black, graphite, iron black (Fe ₃ O ₄ ) and various ferrites are added to a base layer (silicon rubber) in which a powder of a metal oxide such as silica, alumina or magnesium oxide is compounded as a filler. Further, a powder of such a compound, copper oxide, cobalt oxide, red iron oxide (Fe ₂ O ₃ ), or the like may be mixed to have an absorptivity in addition to a light-transmitting property.

The heat ray absorbing layer 171b emits light from a halogen lamp 171g or a xenon lamp (not shown), and is about 90% to 100%, preferably 95%, which is about 100% of the heat ray transmitted through the translucent substrate 171a and the elastic layer 171d. Carbon black, graphite, iron black (F) is used for the resin binder so that the heat ray absorbing layer 171b absorbs about 100% of the heat rays to form a heat ray fixing rotating member capable of instantaneous heating.
e ₃ O ₄ ), various ferrites and compounds thereof, copper oxide, cobalt oxide, heat ray absorbing member mixed with powder such as red iron oxide (Fe ₂ O ₃ ), and has a thickness of 10 to 500 μm, preferably 20 to 100 μm. The heat ray absorbing member is made of an elastic layer 171d.
Is formed by spraying, coating, or the like on the outside (outer peripheral surface). The heat conductivity of the heat ray absorbing layer 171 b is the same as that of the elastic layer 171.
d layer (thermal conductivity is (1-3) × 10 ⁻³ J / cm ·
s · K, specific heat (1-2) × J / g · K, specific gravity 0.9
~ 1.0), a slightly higher (3 to 10) × 10 ^-3 J / cm ·
sK (specific heat is (~ 2.0) x J / gK, specific gravity is (~
0.9)). Heat ray absorbing layer 171
As b, 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. If the heat ray absorption rate in the heat ray absorption layer 171b is lower than about 90%, for example, about 20 to 80%, the heat ray leaks, and the heat ray fixing roller 17a as a heat ray fixing rotating member forms a monochrome image due to the leaked heat ray. When the black toner adheres to the surface of the heat ray fixing roller 17a at a specific position due to filming or the like, heat is generated from the adhering portion due to the leaked heat rays, and heat generated by heat ray absorption is further superimposed on the portion, thereby causing heat ray absorption. The layer 171b is damaged. Further, when used for forming a color image, the absorption efficiency of the color toner is generally low, and there is a difference in the absorption efficiency between the color toners, resulting in poor fixing or uneven fixing. Therefore, the heat ray absorption rate of the heat ray absorbing layer 171b is approximately 100% so that the heat ray emitted from the halogen lamp 171g and transmitted through the light transmitting base 171a and the elastic layer 171d is completely absorbed in the heat ray fixing roller 17a.
To 100%, preferably 95 to 100%. As a result, the color toner, which is difficult to fix by heat rays due to different spectral characteristics, is favorably melted.
In the color image formation, the superimposed color toner image on the transfer material having a thick toner layer, which is difficult to be fixed by heat rays due to different spectral characteristics, is favorably fused. 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 heat rays 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 strength of the heat ray absorbing layer 171b may be insufficient. If 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. The heat ray absorption rate of the heat ray absorption layer 171b is about 10
90% to 100%, preferably 95 to 100%
% Or the thickness of the heat ray absorbing layer 171b is 10 to 500%.
μm, preferably 20 to 100 μm,
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, preferably 0.3 to 20 μm.
３3 μm, a hardness or thermal conductivity modifier is added as a filler, but the average particle size is included, including primary and secondary particles having a particle size of 、, preferably １ ／ or less, of the wavelength of the heat ray. Titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate having a particle diameter of 1 μm or less, preferably 0.1 μm or less, which is transparent to heat (transmits infrared or far infrared rays including visible light depending on the light source). The heat ray absorbing layer 171b may be formed by dispersing 5 to 50% by weight of fine particles of a metal oxide such as a metal oxide in a resin binder. Since the heat capacity of the heat ray absorbing layer 171b is reduced so that the temperature rises immediately, the heat ray fixing roller 17a serving as the heat ray fixing rotating member has a temperature drop, 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). For example, the surface (outer peripheral surface) of an elastic layer 171d having an outer diameter of 50 mm as a heat ray absorbing layer 171b (or a combined layer 171B described later) of the heat ray fixing roller 17a.
A fluororesin having a layer thickness (thickness) of 50 μm (specific heat 2.0
The heat capacity Q3 per A-3 size width (297 mm) of the heat ray absorbing layer 171b (or combined layer 171B) when J / g · K and specific gravity is 0.9) is about 1.0 cal.
/ Deg. 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 30 to 100 μm is coated on the outer side (outer peripheral surface) of the heat ray absorbing layer 171 b separately from the heat ray absorbing layer 171 b in order to improve the releasability from the toner. Or fluorinated resin (PF
A or PTFE) Release layer 171c coated with a paint of 20 to 30 μm (having a thermal conductivity of (1 to 10) × 10 ⁻³ J / cm.
S · K, specific heat (（2.0) × J / g · K, specific gravity (〜0.9)) (separated type).

Further, as shown in the cross section in FIG. 4 (b), carbon black, graphite, iron black (Fe ₃ O ₄ ), various ferrites and their compounds, copper oxide, cobalt oxide, red iron (Fe ₂ O ₃ ), etc. Heat-absorbing member mixed with powder of PTFE, and a fluororesin (PFA or PT) that also serves as a binder and a release agent
FE) is mixed with a paint, and the heat ray absorbing layer 171b and the release layer 171c described above with reference to FIG.
A roll-shaped heat ray fixing rotating member having elasticity may be formed outside (outer peripheral surface) of the elastic layer 171d formed outside (outer peripheral surface). The thermal conductivity of the dual-purpose layer 171B is substantially the same as the thermal conductivity of the heat ray absorbing layer 171b.
10) × 10 ⁻³ J / cm · s · K (specific heat is (∼2.0)
× J / g · K, specific gravity (（0.9)). As described above, the heat ray absorptance of the dual-purpose layer 171B is substantially reduced so that the heat ray emitted from the halogen lamp 171g or the xenon lamp (not shown) and transmitted through the light-transmitting substrate 171a and the elastic layer 171d is completely absorbed. 90 ~ which is 100%
100%, preferably 95 to 100%. Combined layer 1
When the heat ray absorptivity at 71B is lower than about 90%, for example, about 20 to 80%, the heat ray leaks, and when the heat ray fixing rotating member is used for monochrome image formation due to the leaked heat ray, filming or the like occurs. When the black toner adheres to the surface of the heat ray fixing rotating member at a specific position, heat is generated from the adhering portion due to the leaked heat rays, and the heat generated by the absorption of the heat rays is further superimposed on the portion to damage the dual-purpose layer 171B. Further, when used for forming a color image, the absorption efficiency of the color toner is generally low, and there is a difference in the absorption efficiency between the color toners, resulting in poor fixing or uneven fixing.
Accordingly, the dual-purpose layer 17 is so arranged that the heat rays emitted from the halogen lamp 171g and transmitted through the translucent substrate 171a and the elastic layer 171d are completely absorbed in the heat ray fixing rotating member.
90-100 which is equivalent to about 100% of the heat ray absorption rate of 1B
%, Preferably 95 to 100%. In addition, the dual-purpose layer 1
Local heat generation at 71B is also prevented, and uniform heat generation is performed. Further, since the wavelength of the heat ray projected on the dual-purpose layer 171B is 0.1 to 20 μm, preferably 0.3 to 3 μm, an adjuster of hardness and thermal conductivity is added as a filler,波長, preferably 1/5 or less of the wavelength of the average particle diameter of 1 μm or less including primary and secondary particles,
Titanium oxide, aluminum oxide, zinc oxide, silicon oxide having a heat ray transmission of preferably 0.1 μm or less (in some cases, transmitting infrared or far infrared rays including visible light depending on the light source),
Fine layer of metal oxides such as magnesium oxide and calcium carbonate dispersed in a resin binder.
May be formed.

According to FIG. 5, the heat ray absorbing layer 171 of the heat ray fixing roller 17a as a rotary heat ray fixing rotating member is used.
If the above-mentioned concentration distribution of the heat ray absorbing member is provided uniformly in b, heat is concentrated in the heat ray absorption layer 171b at the boundary, and heat easily flows to the elastic layer 171d side. It is preferable to generate heat inside the layer 171b from the viewpoint of dispersing the heat generation distribution. The concentration distribution of the heat ray absorbing layer 171b is as shown in the graph (a).
The interface on the side of the insulated elastic layer 171d is made to have a low concentration and is gradually increased toward the outer peripheral surface side so as to be gradually higher. (At about 4/5) so as to obtain a concentration that absorbs 100% so as to be saturated. As a result, the heat generation distribution due to the absorption of heat rays in the heat ray absorbing layer 171b has a maximum value near the center of the heat ray absorbing layer 171b as shown in the graph (b), and the interface and the outer peripheral surface of the heat ray absorbing layer 171b. It is formed in a parabolic shape having a minimum value in the vicinity. Thereby, heat generation due to absorption of heat rays at the interface is reduced, and damage to the adhesive layer and damage to the heat ray absorbing layer 171b at the interface are prevented. Further, before the outer peripheral surface side (2/3 to 4/5 of the thickness t of the heat ray absorbing layer 171b from the transparent substrate 171a side).
(Position of degree) to the outer peripheral surface so as to saturate the concentration distribution. In particular, even when the dual-purpose layer 171B is used, there is no influence even if the outer peripheral surface layer is shaved. Note that a saturated layer may be formed as shown by a dotted line. 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, the concentration distribution is provided with the inclination, and the heat generation distribution can be adjusted by changing the inclination angle.

As shown in FIG. 6, the outer diameter 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 60 mm, and the thickness is 15 mm. As for the thickness, the thicker one is better in terms of strength, and the thinner one is better in terms of heat capacity. However, from the relationship between strength and heat capacity, the average outer diameter φ and the average thickness t of the cylindrical light-transmitting base 171a are larger. Is 0.05 ≦ t / φ ≦ 0.20, and preferably 0.07 ≦ t / φ ≦ 0.14. When the average outer diameter φ of the translucent substrate 171a is 40 mm, the average thickness t of the translucent substrate 171a is 2 mm ≦ t ≦ 8.
mm, preferably 2.8 mm ≦ t ≦ 5.6 mm. T / φ on the translucent substrate 171a is 0.05
If the ratio is less than 0.20, the strength becomes insufficient. If the ratio t / φ exceeds 0.20, the heat capacity increases, and the heating of the heat ray fixing roller 17a is prolonged. Further, depending on the material, a light-transmitting substrate may absorb about 1 to 20% of heat rays, and it is preferable that the substrate be thin as long as the strength can be maintained.

As described above, the rotating member for hot-wire fixing with good cylindrical accuracy such as roundness and cylindricity of the outer peripheral cylinder is formed, the pressing force and rotation of the rotating member for hot-wire fixing become uniform, and uneven fixing is prevented. In addition, there is provided a fixing device having a heat ray fixing rotating member capable of saving energy and having a short warm-up time and quick start (rapid heating).

[0046]

According to the present invention, a rotating member for fixing a heat ray having good cylindrical accuracy such as roundness and cylindricity of an outer peripheral cylinder is formed, and the pressing force and rotation of the rotating member for fixing a heat ray become uniform.
Fixing unevenness is prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram 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 a side sectional view of the image forming body of FIG. 1;

FIG. 3 is an explanatory diagram illustrating a structure of a fixing device.

FIG. 4 is an enlarged cross-sectional configuration diagram of the roll-shaped rotating member for heat ray fixing in FIG. 3;

FIG. 5 is a diagram showing a concentration distribution of a heat ray absorbing layer of the roll-shaped heat ray fixing rotating member of FIG. 3;

FIG. 6 is a view showing an average outer diameter and an average thickness of a light-transmitting substrate of the roll-shaped rotating member for heat ray fixing of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Photoreceptor drum 11 Scorotron charger 12 Exposure optical system 13 Developing device 17 Fixing device 17a Heat ray fixing roller 171a Translucent substrate 171B Shared layer 171b Heat ray absorbing layer 171c Release layer 171d Elastic layer 171g, 471e Halogen lamp

Claims (4)

[Claims] 1. A fixing device for fixing a toner image on a transfer material to said transfer material by heating and pressurizing, wherein a heat ray irradiating means for emitting a heat ray; A light-transmitting cylindrical substrate having a light-transmitting property, a light-transmitting elastic layer outside the light-transmitting substrate, and a heat ray absorbing layer absorbing the heat rays outside the elastic layer. Forming a roll-shaped rotating member for hot-wire fixing, wherein the thickness of the elastic layer is at least three times the circularity of the outer peripheral cylinder of the translucent substrate. apparatus. 2. The fixing device according to claim 1, wherein a roundness of an outer peripheral cylinder of the translucent substrate is 0.8 mm or less. 3. The layer thickness of the elastic layer is 1 mm or more and 10 m.
The fixing device according to claim 1, wherein m is equal to or less than m. 4. The apparatus according to claim 1, wherein the elastic layer has both a light transmitting property and an absorbing property with respect to the heat ray.
The fixing device according to claim 1.