JP2002139937A - Fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate trouble caused by the difference of the size of transfer material, especially, to eliminate trouble caused in the case of fixation performed to large size transfer material after consecutively performing the fixation to small size transfer material in a fixing device using a thermal fixing roller having translucent base substance and a heat ray absorbing layer. SOLUTION: In this fixing device, the transfer material on which an unfixed toner image is carried is heated while press-contacting with the thermal fixing roller having a heat ray irradiation means inside and provided with an elastic layer having translucency to a heat ray on the outside of cylindrical base substance having translucency to the heat ray and the heat ray absorbing layer on the outside of the elastic layer, so that the toner image is fixed on the transfer material. The device has a light shielding member shielding the transfer material non-passing area of the heat ray absorbing layer from light in accordance with the size of the transfer material.

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 for an image forming apparatus such as a copying machine, a printer, a facsimile, etc., a heat roller fixing system has been used as a fixing device having high technical perfection and stability. It is widely used from monochrome machines to full-color machines.

However, the conventional heat roller type fixing device is disadvantageous in terms of energy saving because it is necessary to heat a heat roller having a large heat capacity when heating a transfer material or toner. There is a problem that it takes time to warm up the apparatus and the print preparation time (warming-up time) becomes longer.

In order to solve this problem, the heat transfer efficiency is reduced by using a film (heat fixing film) to reduce the heat capacity and bringing a temperature-controlled heating element (ceramic heater) or an induction heating element into direct pressure contact with the heat fixing film. Has been proposed, and a film fixing type fixing device which hardly requires energy saving and warm-up time has been proposed and recently used.

Further, as a modification of the heat roller method, a light-transmissive substrate is used as a heat ray fixing roller (heat ray fixing rotating member), and the toner is irradiated with heat rays from a halogen lamp (heat ray irradiation means) provided therein. Japanese Patent Application Laid-Open No. 52-10 / 1982 discloses a fixing method in which heat fixing is performed to shorten the warm-up time.
Nos. 6741 and 57-82240 and 57-82
It is disclosed in, for example, JP-A-102736 and JP-A-57-102741. Further, a light absorbing layer (heat ray absorbing layer) is provided on the outer peripheral surface of the translucent substrate to form a heat ray fixing roller,
A fixing method of absorbing light from a halogen lamp provided inside a cylindrical light-transmitting substrate by a light-absorbing layer provided on the outer peripheral surface of the light-transmitting substrate and fixing the toner image by heat of the light-absorbing layer is particularly characteristic. This is disclosed in Japanese Unexamined Patent Publication No. 59-65867.

The fixing device disclosed in Japanese Patent Application Laid-Open No. 52-106741 and the like discloses a method of irradiating heat rays from a halogen lamp through a light-transmitting substrate to heat and fix the toner. In the fixing device disclosed in the official gazette, a heat ray absorbing layer is provided on the outer peripheral surface of a light transmitting substrate to constitute a heat ray fixing roller, and a heat ray from a halogen lamp is irradiated to the heat ray absorbing layer through the light transmitting substrate. The method of fixing the toner by the heat of the absorption layer is intended to save energy and shorten the warm-up time to achieve a quick start, but the fixing performance is insufficient in practical use.

The inventors of the present application have used a halogen lamp,
An elastic layer made of a rubber material layer is provided between the translucent substrate and the heat ray absorbing layer to form a heat ray fixing roller of a soft roller,
The heat ray absorbing layer is heated by the heat ray from the halogen lamp,
Japanese Patent Application Laid-Open No. 11-327341 has proposed a fixing device capable of performing a quick start and improving the fixing property of a toner image. In particular, since the translucent substrate used for the heat ray fixing roller uses a glass member, there are many cracks at the end when cutting the end, and the heat ray fixing roller is attached to the fixing device and the load is reduced. Is very likely to break from that point as a starting point, and a method of baking the end of the glass base to minimize the flaws generated when cutting to a predetermined length during manufacturing is disclosed in Japanese Patent Application No. Hei 11 (1999). It was proposed in Japanese Patent Publication No. 312291. Further, Japanese Patent Application No. 2000-144925 proposes a method for manufacturing the heat ray fixing roller by integrally molding an elastic layer with a light-transmitting substrate using a mold. Also,
Japanese Patent Application No. 2000-204866 proposes a configuration and a manufacturing method of a fixing device using a heat ray fixing roller.

[0008]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a fixing device using a heat-ray fixing roller having a light-transmitting substrate and a heat-ray absorbing layer. After fixing the size transfer material continuously,
An object of the present invention is to solve a problem when a large-size transfer material is fixed.

A second object of the present invention is to further improve the heat utilization efficiency of a fixing device using a heat ray fixing roller having a light transmitting substrate and a heat ray absorbing layer, thereby achieving energy saving and further shortening the warm-up time. That is.

[0010]

SUMMARY OF THE INVENTION A first object of the present invention is to:
This is achieved by adopting any one of the following constitutions [1] to [6] (this may be referred to as the first present invention).
It has been found that the second object of the present invention is achieved by adopting any one of the following constitutions [7] to [15] (this may be referred to as a second present invention).

[1] An elastic layer having a heat ray irradiating means therein and having a light transmissive property with respect to a heat ray outside a cylindrical base having a light transmissive property with respect to the heat ray; In a fixing device in which a transfer material carrying an unfixed toner image is pressed and heated on a heat ray fixing roller provided with a heat ray absorbing layer and the toner image is fixed to the transfer material, the heat rays are adjusted according to the size of the transfer material. A fixing device comprising: a light-shielding member that shields a transfer material non-passing area of an absorption layer.

[2] The fixing device according to [1], wherein the light shielding member can expand and contract in a longitudinal direction of the roller from near an end of the heat ray fixing roller.

[3] The fixing device according to [1] or [2], wherein the light shielding member is expanded and contracted by a magnet.

[4] The fixing device according to [1] or [2], wherein the light shielding member is expanded and contracted by a spring.

[5] The fixing device according to [4], wherein the spring is a spiral spring.

[6] The fixing device according to any one of [1] to [5], wherein the light-shielding member is capable of expanding and contracting steplessly.

[7] An elastic layer having a heat ray irradiating means inside, an elastic layer having a light transmissive property with respect to the heat ray outside the cylindrical base having a light transmissive property with respect to the heat ray, and an outside of the elastic layer. In a fixing device in which a transfer material carrying an unfixed toner image is pressed and heated on a heat-ray fixing roller provided with a heat-ray absorbing layer and the toner image is fixed to the transfer material, the elastic layer is translucent to heat rays. A fixing device having a function of absorbing heat rays.

[8] The fixing device according to [7], wherein the elastic layer is formed by adding at least an additive to silicone rubber.

[0019]

[9] The fixing device according to [7], wherein the elastic layer is formed by adding at least an additive to fluororubber.

[10] The additive is a metal oxide, [8] or

[9] The fixing device according to [9].

[11] The fixing device according to [10], wherein the metal oxide is iron oxide.

[12] The fixing device according to [10], wherein the metal oxide is titanium oxide.

[13] The additive has a mass ratio of 0.5 to 5% with respect to the total elastic layer [8].
The fixing device according to any one of items [12] to [12].

[14] The wavelength of the elastic layer is 1000n
m. The fixing device according to any one of [8] to [13], wherein a transmittance for light of m is 10 to 60%.

[15] The thickness of the elastic layer is 0.3 to 1
The fixing device according to any one of [8] to [14], wherein the fixing device has a length of 0 mm.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below, and the present invention will be described at the most relevant point to the configuration of the first or second present invention.

Note that the assertive description in the embodiment of the present invention indicates the best mode, and does not limit the technical scope 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 diagram 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.
FIG. 3 is a side cross-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 a roll-shaped heat ray fixing roller of FIG. FIG.
FIG. 6 is a diagram showing a concentration distribution of a heat ray absorbing layer of the roll-shaped heat ray fixing roller of FIG. 6, and FIG. 6 is a view showing an outer diameter and a thickness of a light-transmitting substrate of the roll-shaped heat ray fixing roller of FIG. FIG. 7 is a side sectional view showing driving of the fixing device of FIG.

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

The photosensitive drum 10 is rotated clockwise as shown by an arrow in FIG. 1 with the light-transmitting conductive layer grounded by power from a driving 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. .

As a material of the light-transmitting substrate, an acrylic resin, particularly a material obtained by polymerizing methyl methacrylate monomer, is preferably used because of its excellent light-transmitting properties, strength, precision, surface properties and the like. Various translucent resins such as acrylic, fluorine, polyester, polycarbonate, and polyethylene terephthalate used for optical members and the like can be used.

As the light-transmitting conductive layer, the light-transmitting layer made of indium tin oxide (ITO), tin oxide, lead oxide, indium oxide, copper iodide, Au, Ag, Ni, Al or the like is maintained. A metal thin film is used, and as a film forming method, a vacuum evaporation method, an active reaction evaporation method, various sputtering methods, various CVD methods, a dip coating method, a spray coating method, or the like can be used. As the photoconductor layer, various organic photosensitive layers (OP
C) can be used.

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 of 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 the photosensitive drum 10 between the scorotron charger 11 and the developing device 13 and the 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 in non-contact with the photosensitive drum 10 by abutting rollers (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 applies 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 to the photosensitive drum 10 in a non-contact state. Reversal development is performed with toner having the same polarity as the charge polarity of No. 10 (in this embodiment, the photosensitive drum is negatively charged, and the toner has negative polarity).

As shown in FIG. 2, the photosensitive drum 10 and a holder 20 as an exposure optical system holding member rotatably support the photosensitive drum 10 at the rear and front ends of the apparatus. Drum flanges 10A and 10B as photoconductor drum support members, and optical system flanges 120A and 1 as exposure optical system support members that support holder 20
20B is integrally formed through press-fitting or means such as screws. The photoreceptor drum 10 includes a drum flange 10A and a drum flange 10B serving as a photoreceptor drum support member and an optical system flange 120A of the holder 20.
Shaft 121 and optical system flange 1 integrated with each other
20B is rotatably supported via bearings B1 and B2, respectively.

The shaft 121 has a shaft portion 121A for holding the photoreceptor drum 10, and a support shaft 130 as a shaft holding means having an engagement hole 130A is provided on the rear device board 70. The linear bearing B4 is fitted into the engagement hole 130A, and the receiving member 13
The support shaft 130 is fixed to the device substrate 70 on the rear side by screws or the like with the Oa interposed therebetween. The support shaft 130 is located at the center of the gear G2 that meshes with the drive gear G1, and rotatably supports a conductive member 131 that integrates the gear G2 via a bearing B3. On the other hand, the apparatus substrate 70 on the front side of the apparatus has an opening 70A through which the photosensitive drum 10 having the exposure optical system 12 fixed to the holder 20 can be inserted and removed.

The holder 20 inserts the shaft portion 121A of the shaft 121 into the linear bearing B4 provided on the support shaft 130 with respect to the device board 70 on the back side, and the shaft portion 121A
The engaging pin 121P inserted into the
The exposure optical system 12 is attached by regulating the angular relation position of the exposure optical system 12 by engaging with a V-shaped groove formed on the front side of the exposure optical system 12. With the optical system flange 120C as a support member sandwiching the cushioning material K and pressing the front lid 120D in the axial direction, the screw 5
2 to be mounted at a predetermined position.

A coupling 10C attached to the side of a drum flange 10A serving as a photosensitive drum supporting member for supporting the photosensitive drum 10, a drive pin 131A attached to a side of a conductive member 131 integrated with a gear G2;
With the set screw 51, the drum flange 10A and the gear G
When the photosensitive drum 10 with the holder 20 is integrated, the drum flange 1
Coupling 10C attached to the side of 0A is gear G2.
After the engagement, the conductive member 131 having the gear G2 and the photosensitive drum 10 having the drum flange 10A are aligned with the center and the outer peripheral surface. , From the side of the photosensitive drum 10 using the set screw 51
1A and the coupling 10C are fixed, and the drum flange 10A and the gear G2 are connected and fixed.

When the image forming body drive motor (not shown) is started by the start of image formation, the rotational power of the drive gear G1 is transmitted to the photosensitive drum 10 via the coupling portion by the gear G2, and the photosensitive drum 10 is moved to the position shown in FIG. , And at the same time, application of a 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 (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 device 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 is fed by a feed roller (no code) to a timing roller. It is conveyed to 16.

The transfer material is also called a transfer paper, an image support, or the like, and may be any material that can fix a toner image on a flat plate after transfer, and is usually a plain paper, but may be a transparent resin plate or the like. .

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 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 a hot-rolling roller 17a serving as an upper roll-shaped hot-rolling roller for fixing a color toner image, and an upper hot-rolling roller 17a.
And a pressure roller 47a as a lower roll-shaped pressure member, which forms a pair, and emits a heat ray such as an infrared ray or a far-infrared ray containing visible light depending on the light source at the center of the inside of the heat ray fixing roller 17a. Halogen lamp 171g
A xenon lamp (not shown) or the like is provided as heat ray irradiation means.

Heat ray fixing roller 17a and pressure roller 47
The recording paper P is nipped by a nip portion N formed between the recording paper P and the color toner image on the recording paper P is fixed by applying heat and pressure. Is discharged to the tray at the top of the device.

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 17a for fixing a toner image on a transfer material.
And a pressure roller 47 paired with the heat ray fixing roller 17a.
a. A width of 5 to 5 formed between the heat ray fixing roller 17a having elasticity and the pressure roller 47a.
The recording paper P is sandwiched between the nip portions N of about 20 mm, and the toner image on the recording paper P is fixed by applying heat and pressure. The roller 17a as a roll-shaped heat-ray fixing roller provided on the upper side has a fixing separation claw T from the position of the nip portion N in the rotation direction of the heat-ray fixing roller 17a.
R3, a fixing oil cleaning roller TR1, a heat equalizing roller TR4, and an oil application roller TR2 are provided.

A 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 fixing oil cleaning roller TR1 and the oil application roller TR2. Have been. Also, the heat generation temperature distribution on the peripheral surface of the heat ray fixing roller 17a heated by the heat ray absorbing layer 171b by the heat equalizing roller TR4 using a metal roller member having good thermal conductivity such as an aluminum material or a stainless steel material or a heat pipe is used. Be uniformed. Thereby, the temperature unevenness in the vertical and horizontal directions of the heat ray fixing roller 17a due to the passage of the transfer material is corrected.

Heat ray fixing roller 17a provided on the upper side
Is a cylindrical light-transmitting base 171a and the light-transmitting base 17
Elastic layer 171d and heat ray absorbing layer 1
71b and a release layer 171c are provided in this order. Alternatively, as will be described later in detail with reference to FIG.
Heat ray absorbing layer 171 integrating 1b and release layer 171c
B may be used. In any case, outer diameter 25-50mm
It is configured as a soft roller. Translucent substrate 17
A halogen lamp 171g and a xenon lamp (not shown) are provided in the center of 1a as heat ray irradiation means for emitting heat rays such as infrared rays or far infrared rays. Halogen lamp 1
Heat rays emitted from a 71 g or 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 heat ray fixing roller capable of rapid heating.

The pressure roller 47a as a roll-shaped pressure member, which is paired with the heat ray fixing roller 17a, is a cylindrical metal pipe 471a made of, for example, an aluminum material.
For example, a silicone material is used on the outer peripheral surface of the metal pipe 471a, and the rubber hardness is 10 to 40 Hs (JI
S, A rubber hardness) and a rubber roller 471b formed of a thick rubber layer having a thickness (wall thickness) of 2 to 7 mm and an outer diameter of 2
It is configured as a soft roller of about 5 to 50 mm. An elastic rubber roller having high heat insulating properties is used for the roll-shaped pressure-bonding member to prevent diffusion of heat from the hot-wire fixing roller to the pressure-bonding 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 is driven to rotate while being in contact with the surface of the rubber roller 471b, is provided. The temperature distribution on the peripheral surface of the roller 47a 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 as a heat source may be provided in the center of the inside of the metal pipe 471a. Of course, the same configuration as the upper heat ray fixing roller 17a of the present invention may be used for the lower pressure bonding member.

TS1 is a temperature detecting means using a thermistor for controlling the temperature attached to the heat ray fixing roller 17a. TS2 is a temperature detecting means using a thermistor for controlling the temperature attached to the pressure roller 47a. It is a sensor. As the temperature sensors TS1 and TS2, non-contact type sensors can be used in addition to the contact type.

According to FIG. 4, the configuration of the heat ray fixing roller 17a is such that the thickness (wall thickness) of the cylindrical light transmitting substrate 171a is 1 to 5 mm as shown in the cross section in FIG. Pyrex (registered trademark) glass, sapphire (Al ₂ O ₃ ), CaF _2, etc., preferably 1 to 3 mm thick and transmitting heat rays such as infrared rays or far infrared rays from a halogen lamp 171 g or a xenon lamp (not shown). Ceramic material (thermal conductivity is (5-20) × 10 ⁻³ J / cm · s · K, specific heat is (0.5-2.0) × J / g · K, specific gravity is 1.5-
3.0) is mainly used. Translucent resin using polyimide, polyamide, etc. (thermal conductivity is (2-4) × 1
0 ⁻³ J / cm · s · K, specific heat is (1-2) × J / g ·
K, specific gravity of 0.8 to 1.2) and the like can also be used. As described above, the translucent substrate 171a that is practical has poor thermal conductivity.

The elastic layer 171d has a thickness (thickness) of 0.5 to
For example, a silicone rubber layer or a fluorine rubber layer having a thickness of 5 mm, preferably 1 to 3 mm, which transmits a heat ray (infrared ray or visible ray including visible light depending on the light source), or a silicone rubber layer or a fluorine rubber layer (base layer) ). For the 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, magnesium oxide or the like as a filler into the base layer is adopted. 1-3) ×
10 ⁻³ J / cm · s · K, specific heat of (1-2) × J / g ·
K, a silicone rubber layer or a fluorine rubber layer having a specific gravity of 0.9 to 1.0 is used. Since the silicone rubber layer and the fluorine rubber layer have a lower thermal conductivity than the translucent substrate 171a using a glass member (the thermal conductivity is (5 to 20) × 10 ⁻³ J / cm · s · K), the heat insulating property Serves as a layer. Increasing the thermal conductivity generally tends to increase the rubber hardness.
Those of Hs become high to nearly 60 Hs (JIS, A rubber hardness). Elastic layer 171d of heat ray fixing roller
Is mostly occupied by the base layer, and the amount of compression at the time of pressurization is determined by the rubber hardness of the base layer. Therefore, the preferable rubber hardness is 10 to 50 Hs. The intermediate layer of the 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. 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, the filler used as the hardness and thermal conductivity modifier described above has a particle size of An average particle diameter of 1 μm including primary and secondary particles having a wavelength of 線, preferably １ ／ or less of the wavelength of the heat ray.
Metals such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. having a heat ray transmission of not more than m, preferably not more than 0.1 μm (depending on the light source, transmitting infrared or far infrared rays including visible light). The elastic layer 171d may be formed by dispersing oxide fine particles 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. By providing the elastic layer 171d, the heat ray fixing roller 17a is configured as an elastic soft roller.

The transparent substrate 171a and the elastic layer 171d are
90-100%, which is about 100% of transmitted heat rays, good
More preferably, 95 to 100% of heat rays are applied to the heat ray absorbing layer 171b.
Forming a heat ray fixing roller that absorbs more and can be heated quickly
Therefore, the heat ray absorbing layer 171 b
Black, graphite, iron black (Fe_ThreeO_Four) And various ferrites
And its compounds, copper oxide, cobalt oxide, red iron oxide (F
e_TwoO_Three) Is used. thickness
10-500 μm, preferably 20-100 μm thick heat
Spraying the line absorbing member on the outside (outer peripheral surface) of the elastic layer 171d
Alternatively, it is formed by coating or the like. Heat of heat ray absorbing layer 171b
The conductivity is controlled by adding an absorbent such as carbon black.
The base layer of the elastic layer 171d (having a thermal conductivity of (1-1
0) × 10 ^-3J / cm · s · K)
100) × 10^-3It can be set to J / cm · s · K
Wear. The specific heat of the heat ray absorbing layer 171b is (0.2 to 2.0)
× J / g · K, and the specific gravity is 0.4 to 1.9. heat
The wire absorbing layer 171b is made of a metal such as a nickel electroformed roller.
The roller member may be provided with a similar thickness. At this time, hot wire
The inside (inner peripheral surface) is black oxidized to absorb
Preferably. Heat ray absorption in the heat ray absorbing layer 171b
If the rate is lower than about 90%, for example, about 20-80%
If there is, the heat rays will leak and the leaked heat rays will cause
The heat ray fixing roller 17a forms a monochrome image.
When used for heat-sealing,
When black toner adheres to the surface of the
Heat is generated from the adhering part, which further absorbs heat rays
Heat generation occurs repeatedly and damages the heat ray absorbing layer 171b.
You. When used for color image formation, color toner
Is generally low in absorption efficiency and absorbed between color toners.
Due to the difference in efficiency, poor fixing or uneven fixing
Becomes Therefore, 171 g of halogen lamp or xenon lamp
A light-transmitting base 171a and a bullet
The remaining heat ray absorbed by the conductive layer 171d is the heat ray absorbing layer 1
The heat ray absorbing layer 171b is completely absorbed by the heat ray absorbing layer 171b.
The heat ray absorption rate is set to approximately 100%. With this, the spectral characteristics
However, the melting of color toners different from each other is favorably performed. Especially figure
As in the color image forming apparatus shown in FIG.
-Overlaid color toner images with thick layers
Will be The thickness of the heat ray absorbing layer 171b is less than 10 μm.
When it is full and thin, it is due to absorption of heat rays in the heat ray absorption layer 171b.
Heating rate is fast, but heat rays due to local heating by thin film
This may cause damage to the absorption layer 171b and insufficient strength, and
If the thickness of the collecting layer 171b exceeds 500 μm and is too thick,
Insufficient heat conduction, large heat capacity and rapid heating
It is difficult to achieve. The heat ray absorption rate of the heat ray absorption layer 171b is approximately
90 to 100%, which is 100%, preferably 95 to 1
00%, or the thickness of the heat ray absorbing layer 171b is 10 to 5%.
00 μm, preferably 20 to 100 μm.
Therefore, local heat generation in the heat ray absorbing layer 171b is prevented,
Uniform heat generation occurs. Also, the heat ray absorbing layer 171b is
The wavelength of the emitted heat ray is 0.1-20 μm, preferably
Since it is 0.3 to 3 μm, hardness and heat transfer
A conductivity adjuster is added, but the particle size is 1 / the wavelength of the hot wire.
2, preferably 1/5 or less, including primary and secondary particles
Heat having an average particle size of 1 μm or less, preferably 0.1 μm or less
Line transmittance (Depending on the light source, infrared or visible light
Titanium oxide, aluminum oxide, acid
Zinc oxide, silicon oxide, magnesium oxide, calcium carbonate
Fine particles of metal oxides such as
The heat ray absorbing layer 171b is formed with
Is also good. In this case, the heat rays are supplied to the inside of the heat ray absorption layer 171b.
And heat generation at the interface can be prevented. in this way
Then, the heat ray absorbing layer 171b is set so that the temperature rises immediately.
As the heat capacity is small, it can be used as a fixing roller for heat rays.
The temperature of the heat ray fixing roller 17a decreases, causing uneven fixing.
To prevent the problem that occurs.

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 applied 20 to 100 μm, or molded silicone rubber or fluoro rubber with a layer thickness of 20 to 500 μm, having a thermal conductivity of (3 to 100) × 1
A release layer 171c of 0 ⁻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) Mix with paint or silicone rubber or fluorine rubber.
The heat ray absorbing layer 17 described above with reference to FIG.
1b and the release layer 171c.
And the release layer 171c are integrated with each other to release heat.
The collecting layer 171B is formed on the outside (outer peripheral surface) of the translucent substrate 171a.
Formed outside (outer peripheral surface) of the elastic layer 171d formed
To form a roll-shaped heat ray fixing roller having elasticity.
It is preferable that each embodiment described in detail below
In this case, 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
It will be explained in. As will be described in detail later,
A heat absorbing device in which the absorbing layer 171b and the release layer 171c are integrated.
The storage layer 171B has a thickness of about 20 to 100 μm.
PFA (perfluoroalkoxy) tube containing carbon
One coated with a tub is preferably used. Heat wire mentioned above
A heat absorbing device in which the absorbing layer 171b and the release layer 171c are integrated.
The thermal conductivity of the storage layer 171B is the same as that of the heat absorbing layer 171b.
(3-10) × 10^-3J / cm · s · K
It is.

According to FIG. 5, the heat ray absorbing layer 171 of the heat ray fixing roller 17a as a roll-shaped heat ray fixing roller is provided.
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).
In this case, heat is concentrated, and heat easily flows to the elastic layer 171d (or the heat ray absorbing layer 171B) side. Therefore, the heat ray absorbing layer 171b (or the heat ray absorbing layer 1
It is preferable to generate heat inside 71B) from the viewpoint of dispersing the heat generation distribution. For this reason, the heat ray absorbing layer 171
b (or the heat ray absorbing layer 171B) is indicated by a dotted line (a
As shown in -2), the interface on the side of the insulated elastic layer 171d is made to have a low concentration, is gradually increased toward the outer peripheral surface side, and is gradually increased toward the outer peripheral surface side (the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B)). (At a position about 1/2 to 3/5 from the elastic layer 171d side with respect to the thickness t1), so that the concentration becomes 100% so as to be saturated. This allows
As shown by the curve (b-2), 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) is represented by the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B).
Is shifted from the interface with respect to the thickness t1 of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B) so as to be located about 1/3 to 2/5 from the elastic layer 171d side. And the heat ray 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 with an inclination, whereby the heat ray absorbing layer 171b is formed as shown by a curve (b-3).
The heat distribution of the heat ray absorbing layer 171B (or the heat ray absorbing layer 171B) has a maximum value near the center of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B), and the interface or the outer peripheral surface of the heat ray absorbing layer 171b (or the heat ray absorbing layer 171B). Is formed in a parabolic shape having a minimum value, and the influence of the scraping of the outer peripheral surface layer is small. 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. 6, the outer diameter φ of the cylindrical translucent substrate 171a of the heat ray fixing roller 17a as a roll-shaped heat ray fixing roller 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 becomes large and the heating time 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 elastic layer 171d is 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.

In particular, in the second aspect of the present invention, an additive such as a metal oxide is added to a rubber layer such as a silicone rubber or a fluorine rubber forming the elastic layer 171d in order to secure strength.

Conventionally, in order to increase the amount of heat generated by the heat ray absorbing layer on the surface, it has been attempted to increase the light transmittance of the elastic layer as much as possible so that light is transmitted to the heat ray absorbing layer to increase the heating rate. However, even if the light absorption in the elastic layer becomes large to some extent, if the thickness of the elastic layer can be reduced, the actual rate of temperature rise is hardly changed. It was found that the durability of the roller as a whole was significantly improved.

As a result, although the coloring degree of the elastic layer 171d is slightly increased, heat resistance is extremely increased. As an additive, metal oxide is preferable, and iron oxide and titanium oxide are particularly preferable.

An example of a specific embodiment of the second aspect of the present invention is as follows. A silicone rubber layer having a thickness of 1.0 mm outside a glass pipe having a diameter of 28 mm and a thickness of 1.5 mm,
A 0.05 mm thick perfluoroalkoxy resin (PFA) was coated as a heat ray absorbing layer and a release layer. The rubber layer uses a heat-resistant rubber to which an additive containing iron oxide as a main component is added. Heat rays from a halogen lamp disposed inside the pipe (roller) pass through the rubber layer while being gradually absorbed while passing through the rubber layer, reach the heat ray absorbing layer, generate heat, and heat the roller surface.

The ratio of the additive to the entire elastic layer 171d is preferably 0.5 to 5% by mass, and since the heat resistance can be sufficiently secured at this level, the elastic layer 171d can be made thinner. Overall durability can be increased without significantly impairing light properties. In this case, the transmittance of the elastic layer at a light wavelength of 1000 nm is 10 to 60% / m.
m, and the thickness of the elastic layer is in the range of 0.3 to 10 mm.

According to FIG. 7, the heat ray fixing roller 17a, which is a heat ray fixing roller of the fixing device 17, includes a light transmitting base 171a and an elastic layer 171d and a heat ray absorbing layer 171b on the outside (outer peripheral surface) thereof. And a release layer 171c in that order, or a translucent substrate 171a and the outside (outer peripheral surface) thereof.
An elastic layer 171d and a heat ray absorbing layer 171B on the outer side (outer peripheral surface) of the heat ray absorbing layer 171b and the release layer 171c are provided in this order. In parallel with the central axis of the light-transmitting substrate 171a, both ends of the outer peripheral surface of the light-transmitting substrate 171a are provided, for example, with heat-resistant polyimide resin or polyphenylene sulfide resin (P
A resin flange JF1 using a resin member such as PS resin is provided. The resin flange JF1 having a large coefficient of thermal expansion provided at the outer (outer peripheral surface) end of the translucent substrate 171a allows
Breakage of the light-transmitting substrate 171a due to thermal expansion during heating of the light-transmitting substrate 171a mainly using a glass member is prevented. Heat ray fixing roller bearing B5, which is a bearing member of the heat ray fixing roller pressed into bearing holder BH1
Is a resin flange JF1 as a holding member for the translucent substrate.
And the heat ray fixing roller 17a is rotatably held. At this time, the heat ray fixing roller bearing B5 as the bearing member of the heat ray fixing roller is directly fitted into the end of the light transmissive base 171a without providing the resin flange JF1 as the holding member for the light transmissive base. Thus, the configuration may be such that the translucent base 171a of the heat ray fixing roller 17a is held. At both ends of the heat ray fixing roller 17a, receiving plates PLa made of a resin material having good slipperiness, for example, using a fluorine resin or the like are provided, and the heat ray fixing roller 17a is positioned from both ends. A halogen lamp 171g or a xenon lamp (not shown) is provided as a heat ray irradiating means inside the heat ray fixing roller 17a.

Further, a cylindrical metal pipe 471a is provided in a pair with the upper heat ray fixing roller 17a.
A pressure roller 47a as a lower roll-shaped pressure member formed by a rubber roller 471b using, for example, a silicone material on the outer peripheral surface of the metal pipe 471a,
A metal pipe 471a is fitted into a bearing B6 that is pressed into the bearing holder BH2 while being pressed against the upper heat ray fixing roller 17a, and is held rotatably. The driving of the gear Ga provided at one end of the metal pipe 471a of the pressing roller 47a drives and rotates the pressing roller 47a, and the heat ray fixing roller 17a is driven to rotate. A halogen lamp or a xenon lamp (not shown) may be provided inside the press roller 47a as a heat ray irradiation unit.

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

The use of the fixing device 17 described with reference to FIG. 3 makes it possible to provide a fixing device that is resistant to deformation at the fixing portion (nip portion) and that can perform quick start (rapid heating). Due to the pressure in the soft fixing portion (nip portion) due to the elasticity of the toner and the heating by the heat ray absorbing layer of the heat ray fixing roller, the melting of the color toner which is difficult to fix by the heat ray due to the difference in spectral characteristics. It is performed well, and quick start (rapid heating) fixing of the color toner becomes possible. Also, an energy saving effect can be obtained.

However, in the heat ray fixing roller of the present invention, the cylindrical substrate is made of glass or a heat-resistant resin.
Since the elastic layer and the heat ray absorbing layer are provided thereon, the thermal conductivity is extremely lower than that of a roller having a metallic pipe as a base, as in a normal heat fixing device. Therefore, even if a large temperature difference is generated between the portion where the roller surface is in contact with the transfer material and the portion where the roller surface is not in contact with the heat ray fixing roller, it is difficult to level the difference. In particular, after passing small-size paper continuously, only a part of the heat ray fixing roller touched the transfer material. Because the surface temperature of the roller is much higher, high temperature offset is likely to occur. In addition, the durability of the heat ray fixing roller itself is reduced, so that it has been found that a countermeasure is necessary. The first present invention has found this countermeasure.

In the first aspect of the present invention, a light-shielding member is provided at an end of the heat-ray fixing roller to shield an area of the heat-ray absorbing layer where the transfer material does not pass. The specific method is not particularly limited, and various methods can be considered. The typical method is shown below.

FIG. 8 is a cross-sectional view showing the expansion and contraction mechanism of the light-shielding multistage cylinder 100 as a light-shielding member according to the present invention. The method of shielding the transfer material non-passing area of the heat ray absorbing layer 171B uses an electromagnet. A telescopic mechanism using the electromagnet N 101 and the electromagnet S 102 is provided inside the translucent substrate 171a. For example, A3 and vertical A4 correspond to the most contracted state, and A4 horizontal and two-stage when extended one step. In the extended state, the halogen lamp in the non-transferring portion of the transfer material is shielded from light so as to correspond to a postcard. When an electromagnet having a polarity is installed as shown in FIG. 8, only an arbitrary unit can be extended by energizing a necessary portion.

As a result, since the heat conductivity of each member is low, the heat of the paper passing portion is not significantly transmitted to the transfer material non-passing portion, and the temperature of the roller is suppressed to a low level in the light-shielded portion.

FIG. 9 shows a multi-stage light-blocking cylinder 10 as a light-blocking member.
It is a perspective view which shows the 0 expansion-contraction mechanism. The light shielding method for the transfer material non-passing area of the heat ray absorbing layer is a method using a spiral spring 103. For example, as a transfer material usually used, the light shielding members corresponding to the widest A3 or A4 length from the most contracted state to the position corresponding to the widest light shielding area, for example, to a postcard corresponding to a postcard are used. Can be continuously extruded.

FIG. 10 is a structural view showing a telescopic mechanism of the light-blocking multistage cylinder 100 as a light-blocking member. The method of shielding the transfer material non-passing area of the heat ray absorbing layer is a method using the wire 104. The wire wound around the pulley 105 is rotated in and out of the motor 106, and the light-shielding area is increased or decreased by extending or contracting the light-shielding multistage cylinder connected to the end of the wire.

[0085]

According to the present invention, first, a problem due to a difference in size of a transfer material in a fixing device using a heat ray fixing roller having a light transmitting substrate and a heat ray absorbing layer, particularly a small size transfer material. Can be solved in the case where a large-size transfer material is fixed after the image is continuously fixed.

Second, the heat utilization efficiency of a fixing device using a heat-ray fixing roller having a light-transmissive substrate and a heat-ray absorbing layer can be further increased, and energy saving and further shortening of the warm-up time can be achieved.

[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.

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 heat ray fixing roller of FIG. 3;

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

FIG. 6 is a view showing the outer diameter and thickness of a light-transmissive substrate of the roll-shaped heat ray fixing roller of FIG. 3;

FIG. 7 is a side sectional view showing driving of the fixing device of FIG. 3;

FIG. 8 is a cross-sectional view showing a telescopic mechanism of the light-shielding multistage cylinder.

FIG. 9 is a perspective view showing a telescopic mechanism of the light-shielding multistage cylinder.

FIG. 10 is a configuration diagram showing a telescopic mechanism of a light-shielding multistage cylinder.

[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 pressure roller 100 light shielding multi-stage cylinder 171a light transmitting substrate 171b, 171B heat ray absorbing layer 171c release layer 171d elastic layer 171g , 471c Halogen lamp B5 Heat roller fixing roller bearing N Nip P Recording paper

Claims (15)

[Claims] 1. An elastic layer having a heat ray irradiating means inside thereof, an elastic layer having a light transmissive property with respect to the heat rays outside a cylindrical base having a light transmissive property with respect to the heat rays, and In a fixing device in which a transfer material carrying an unfixed toner image is pressed and heated on a heat ray fixing roller provided with a heat ray absorbing layer and the toner image is fixed to the transfer material, the heat ray absorption is adjusted according to the size of the transfer material. A fixing device comprising: a light-shielding member that shields a transfer material non-passing region of a layer from light. 2. The fixing device according to claim 1, wherein the light shielding member can expand and contract in a longitudinal direction of the roller from near an end of the heat ray fixing roller. 3. The fixing device according to claim 1, wherein the light shielding member is expanded and contracted by a magnet. 4. The fixing device according to claim 1, wherein the light shielding member expands and contracts by a spring. 5. The fixing device according to claim 4, wherein the spring is a spiral spring. 6. The fixing device according to claim 1, wherein the light-shielding member is capable of expanding and contracting in a stepless manner. 7. An elastic layer having a heat ray irradiating means inside and having a light transmissive property with respect to a heat ray outside a cylindrical base having a light transmissive property with respect to the heat ray, and an elastic layer having a heat ray irradiating means outside the elastic layer. In a fixing device in which a transfer material carrying an unfixed toner image is pressed against a heat-ray fixing roller provided with a heat-ray absorbing layer and heated by pressing, the elastic layer is translucent to heat rays. A fixing device having a function of absorbing heat rays. 8. The fixing device according to claim 7, wherein the elastic layer is formed by adding at least an additive to silicone rubber. 9. The fixing device according to claim 7, wherein the elastic layer is formed by adding at least an additive to fluoro rubber. 10. The fixing device according to claim 8, wherein the additive is a metal oxide. 11. The fixing device according to claim 10, wherein the metal oxide is iron oxide. 12. The fixing device according to claim 10, wherein the metal oxide is titanium oxide. 13. The method according to claim 8, wherein said additive is 0.5 to 5% by mass relative to the total elastic layer.
3. The fixing device according to claim 2. 14. The fixing device according to claim 8, wherein the elastic layer has a transmittance of 10 to 60% for light having a wavelength of 1000 nm. 15. The thickness of the elastic layer is 0.3 to 10 mm.
The fixing device according to claim 8, wherein: