JPH11184284A - Fixing device and passbook printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure excellent fixing performance, to make a fixing roller strong with respect to a heating and cooling cycle and mechanical strength and to obtain a fixing state with high image quality extending over a long term by providing a device with the fixing roller having a heat source and a pressure roller and constituting the mold- released layer of the fixing roller of amorphous silicon. SOLUTION: The fixing roller 30 is provided with a surface protection layer consisting of the amorphous silicon as the mold-released layer at the outside circumferential surface of a core bar consisting of aluminum and the like and constituted so that a heater 22 is arranged inside as the heat source. The pressure roller 24 is provided with an elastic layer 24a consisting of silicone rubber at the outside circumferetial surface of a core bar 24a, made to press-contact with the roller 22 by a spring 21 and arranged so as to form a nip part for interposing and carrying a passbook. By constituting the mold-released layer of the roller 30 of the amorphous silicon, the roller 30 becomes excellent in releasing property with respect to toner and the mechanical strength thereof becomes high. Thus, even when a thick transfer material and a booklet-like transfer material are used for fixing as the transfer material, the surface of the fixing roller is not damaged.

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 in an electrophotographic printing device and the like, and more particularly to a printing durability and reliability.

[0002]

2. Description of the Related Art Conventionally, a heat roller fixing system using a fixing roller and a pressure roller has been known as one of fixing devices used in an electrophotographic apparatus. Here, the fixing roller is
In general, a core bar is provided with a layer formed of an elastic body and having a releasability on an outer peripheral surface of the core bar, and a heater is disposed inside as a heat source. The pressure roller is provided with a layer formed of an elastic body and having a releasability on the outer peripheral surface of the cored bar, and is arranged so as to be in pressure contact with the fixing roller to form a nip portion for nipping and conveying the transfer material. ing.

Around the fixing roller, there are provided a separating claw for preventing the transfer material from being wound as required, a temperature detecting sensor for detecting the surface temperature, a cleaner for cleaning the offset toner, and the like. Be placed.

Examples of the surface layer of the fixing roller include PFA (polyfluoroalkoxy) and PTFE having a thickness of about 100 μm.
A fluororesin such as (polytetrafluoroethylene) is used. Further, in order to further improve the releasability, a thickness of 1 to 1
A silicone rubber of about 3 mm is used, and means for applying a release agent such as silicone oil may be added.

[0005] Such a fixing device is disclosed in JP-A-63-1.
It is described in JP-A-48285 and JP-A-1-82080.

[0006]

However, in the above-described fixing device, the use of a heating / cooling cycle or a sliding member such as a separation claw and a temperature detection sensor causes damage to the surface layer of the fixing roller when used for a long period of time. Is not long. Further, when silicone rubber is used for the surface layer, the silicone rubber absorbs silicone oil and the dimensions may change, leading to image deterioration.

Further, when a thick booklet-like transfer medium such as a passbook or a passport is used, the surface of the fixing roller is easily damaged by the medium edge or over a step, including the one using a fluororesin, and the life of the apparatus is shortened. Be shorter. In the case where the brush for static elimination is used, there is also a problem that the offset toner adheres to the tip of the brush to reduce the static elimination effect and increase the offset toner.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a long-life fixing device which has good fixing performance, is strong in a heating / cooling cycle and mechanical strength, has dimensional stability, and can perform high-quality fixing over a long period of time. Is to provide.

[0009]

Means for Solving the Problems In order to achieve the above-mentioned object, the following arrangement is provided.

A fixing device comprising: a fixing roller having a heat source; and a pressure roller in contact with the fixing roller. The fixing device fixes the toner image on the transfer material by sandwiching the transfer material between the two rollers. Is made of amorphous silicon.

A fixing device comprising a fixing roller provided with a heat source and a pressure roller in contact with the fixing roller, wherein the fixing roller fixes the toner image to the transfer material by sandwiching the transfer material between the two rollers. A light source for static elimination is provided in the vicinity of the surface, and the release layer of the fixing roller is made of amorphous silicon having a photoconductive layer.

A passbook insertion / receipt port, an information reading / writing mechanism for reading / writing information of the passbook inserted from the insertion / receipt port, an image reading mechanism for judging a printing state of the passbook from which the information has been read, An electrophotographic printing mechanism comprising a rotatable image carrier on which an electrostatic latent image is formed and a charger, an exposing device, a developing device, a transfer device, a cleaner and a fixing roller disposed around the image carrier. A passbook printing apparatus including a passbook page turning mechanism and a transport roller for transporting the passbook between these mechanisms, wherein a release layer of the fixing roller is made of amorphous silicon.

Since the release layer is made of amorphous silicon, it has excellent releasability from toner and high mechanical strength, so that it can be fixed to a thick transfer material or a booklet as a transfer material. The surface of the fixing roller is not damaged. Further, sliding scratches due to a temperature sensor and a cleaning member provided in contact with the outer periphery of the fixing roller do not occur.

Further, even if charges are accumulated on the surface of the fixing roller due to frictional charging generated between the fixing roller and the pressure roller, the photosensitive layer can be reliably discharged without contact by irradiating the photosensitive layer with light having an absorption wavelength. Therefore, the electrostatic offset can be prevented with a simple configuration.

[0015]

1 and 2 show a first embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 shows a configuration of the fixing device 9 of the first embodiment, and FIG. 2 shows a cross-sectional configuration of a surface layer of the fixing roller 30.

The fixing roller 30 has a surface protection layer 30b made of amorphous silicon as a release layer on the outer peripheral surface of a core metal 30a made of aluminum or the like, and a heater 22 as a heat source inside. Further, the pressure roller 24 is provided on the outer peripheral surface of the metal core 24a.
An elastic layer 24b made of silicon rubber is provided, and the fixing roller 3
0 is pressed against each other by a spring 21 so as to form a nip portion for pinching and conveying the passbook.

Around the fixing roller 30, a separating claw 23 for preventing the passbook from being wound, a temperature detecting sensor 20 for detecting the surface temperature, and a fixing cleaning member 26 for cleaning the offset toner are arranged. . The surface temperature of the fixing roller 30 is maintained at a predetermined value by adjusting the heater 22 with the temperature detection sensor 20 and a temperature controller (not shown).

The surface protective layer 30b is formed by glow discharge decomposition (plasma CVD). The structure of the film may be a single layer because it does not require photosensitivity. In order to increase the mechanical strength, amorphous silicon carbide (a
-SiC: H) layer is effective. Its surface hardness is Vickers hardness of 1500 to 2000, which is several tens times or more that of fluororesin. Further, the film thickness may generally be around 0.5 μm.

As described above, the surface protection layer 30b made of amorphous silicon is provided on the surface layer of the fixing roller 30 of the fixing device 9, so that it has excellent heat resistance and mechanical strength as compared with the conventional fluorine resin layer and elastic rubber layer. As a result, material deterioration due to the heating / cooling cycle and sliding scratches caused by sliding members such as the separation claw and the temperature detection sensor do not occur. Further, even when a medium having a booklet shape like a passbook, that is, having a step and having a large thickness is fixed, the surface of the fixing roller 30 is not damaged.
As a result, it can be used for a long time, and the life can be extended. Further, by forming the amorphous silicon layer into a single-layer structure, the film formation time is shorter than in the conventional case, and the cost can be suppressed.

Next, the second embodiment of the present invention will be described with reference to FIGS.
An example will be described. FIG. 3 shows a fixing device 9 according to the second embodiment.
FIG. 4 shows a cross-sectional configuration of the surface layer of the fixing roller 30.
The difference from the first embodiment lies in that a light source 27 for static elimination is provided at a predetermined interval on the outer periphery of the fixing roller 30,
30 is that an amorphous silicon layer including a layer having photoconductivity is provided. As the charge removing light source 27, an LED having an emission wavelength of 660 to 710 nm including a wavelength region in which amorphous silicon has a high light absorption coefficient can be used. Since the temperature near the surface of the fixing roller 10 becomes 100 ° C. or higher, a heat-resistant protective cover 28 made of a light-transmitting material such as heat-resistant glass may be provided in order to protect the light source for static elimination.

As shown in FIG. 4, the amorphous silicon layer has a carrier injection blocking layer 30c for preventing charge injection from the core 30a, and a charge elimination light source 2 above the aluminum core 30a.
Photosensitive layer 3 that generates and transports photocarriers by light irradiation of 7
0d and the surface protection layer 30b. Carrier injection blocking layer 30c
As amorphous silicon carbide (a-Si
C: H), hydrogenated amorphous silicon (a-Si: H) is used as the photosensitive layer 30d, and amorphous silicon carbide (a-SiC: H) is used as the surface protective layer 30b. Although it is preferable to provide the surface protective layer 30b from the viewpoint of mechanical strength, the photosensitive layer 30d may be used as the surface layer.

With such a configuration, when the pressure roller 24 and the fixing roller 30 are rotated, frictional charge is generated, and the electric charge e accumulated on the surface of the fixing roller 30 is eliminated as follows.

When the light from the light source 27 for discharging is irradiated, the photosensitive layer 30 is exposed.
Light is absorbed in d and electron-hole pairs are generated. Charge e
Is a positive charge, holes are carried in the photosensitive layer 30d by the electric field and move toward the carrier injection blocking layer 30c, and the core metal 30a
Flow into On the other hand, the electrons remaining on the photosensitive layer 30d are combined with the charges e, which are positive charges on the surface, so that the charges e charged on the surface of the fixing roller can be removed. The holes flowing into the cored bar 30a are escaped by the ground (not shown). When the charge e is a negative charge, electrons are carried by the electric field in the photosensitive layer 30d, move toward the carrier injection blocking layer 30c, and
Since it flows into 0a, the charge e charged on the surface of the fixing roller can be similarly removed.

The static elimination and fixing operations of the second embodiment will be described with reference to FIG.

The static elimination light source 27 is controlled so as to be turned on when the printing mechanism starts operating. And fixing roller
The electric charge e accumulated on the surface of the substrate 30 is subjected to photo-elimination as described above.

In the state where the surface of the fixing roller 30 is discharged, the first
The charged toner image t1 transferred onto the passbook p by the same operation as that of the embodiment is not electrostatically offset even if sent to the fixing device 9, and is fixed by heat and pressure to become the final image t2. . In addition, even if the electric charge is received from the toner on the passbook, the electric charge is similarly eliminated by the light-emission light source 27. Then, at the end of printing, the light source 27 for static elimination is turned off.

As described above, on the surface layer of the fixing roller 30 of the fixing device 9, the light source 27 for static elimination is disposed near the surface of the fixing roller 30,
By providing the photosensitive layer 30d, the charge e on the surface of the fixing roller can be removed in a non-contact manner, so that the charge removing effect does not change with time. As a result, the amount of offset toner on the roller surface decreases, and a high-quality fixed image can be obtained over a long period of time. If the fixing device is such that the offset during fixing is not so noticeable, the photosensitive layer 30d is directly applied to the core metal 30a.
And the carrier injection blocking layer 30c need not be particularly provided.

In any of the embodiments, means for applying silicone oil to the surface of the fixing roller may be provided in order to further enhance the releasability of the toner.

FIG. 5 shows a passbook printing apparatus equipped with a fixing device according to an embodiment of the present invention. In the present embodiment, the passbook is installed in the passbook printing device, but the automatic teller machine, the passbook issuing machine,
Any device using an electrophotographic printing device, such as a printer or a copier, may be mounted on any device.

The passbook printer 1 reads information written on a magnetic stripe attached to the front or back cover of the passbook insertion / reception slot Z, passbook p, and / or writes information on the magnetic stripe. An information reading / writing mechanism 3, an image reading mechanism 5, a printing mechanism 18, a page turning mechanism 17, and a predetermined section between each mechanism for determining how many pages and lines are printed when printing on the passbook p. Conveying roller pairs 2, 4, 6, 7, and 10 are arranged at a pitch.

In the printing mechanism 18, a photosensitive member as an image carrier
Around 16, a charger 13, an exposure unit 14, a developing unit 15, a static eliminator 12,
There are 11 cleaners. A transfer device 8 is provided facing the photoconductor 16, and a fixing device 9 is arranged at a predetermined interval from the photoconductor 16.

Each mechanism may be arranged in the order of, for example, the magnetic information reading / writing mechanism 3, the image reading mechanism 5, the page turning mechanism 17, and the printing mechanism 18 from the passbook insertion / receiving port Z side.

Hereinafter, the operation of the passbook transaction will be described. The passbook p inserted into the insertion slot Z is transported by the transport roller 2 and reads or writes information written on a magnetic stripe of the passbook by the magnetic information read / write mechanism 3. Next, the print page and the number of prints already printed on the print page are read by the image reading mechanism 5, recognized by an image information recognition unit (not shown), and the data is sent to the control device.

Based on the above two pieces of information, the control device determines whether or not to print. If it is determined that printing is to be performed, the control device sends a print command and print data. The passbook p that has passed through the image reading mechanism 5 is sent to the position of the conveying roller pair 7, where the paper is arranged and waits at that position. The transfer timing is such that the toner (image) t1 on the photoconductor 16 and the position where the passbook p is to be recorded are moved at the same timing so that the transfer unit 8 and the photoconductor 16 are moved to the area where the transfer unit 8 and the photoconductor 16 are pressed or approached. Be started.

In the printing mechanism 18, an electrostatic latent image is formed on the photoreceptor 16 by the charger 13 and the exposure device 14 in response to an image recording start signal from a control device (not shown).

In the developing device 15, the charged toner is transferred to the photosensitive member 16.
Is electrostatically attached to the electrostatic latent image on the surface of the toner image to form a visible image toner (image) t1. Then, the toner (image) t1 on the photoconductor 16 moves to the position of the transfer unit 8 as the photoconductor 16 rotates.

In parallel with these operations, the transfer unit 8 applies a mechanical pressure and a transfer electric field suitable for the thickness of the passbook from behind the passbook p to the photoconductor 16 by the transfer unit 8. The upper toner (image) t1 is transferred. Untransferred toner (not shown) remaining on the photoconductor without being transferred onto the passbook in the transfer process is collected by the cleaner 11.

The toner image t1 transferred to the passbook p is sent to the fixing device 9 and fixed by heat and pressure to become a final image t2. Here, the minute amount of toner t3 offset on the fixing roller 30 is wiped off by the fixing cleaning member 26.

When printing is performed over a plurality of pages, after passing through the fixing device 9, the pages are turned by the page turning mechanism 17 and the same printing operation as described above is repeated. Then, the passbook p is sent back to the passbook insertion and receiving port Z at the end of printing.

[0040]

According to the present invention, the surface of the fixing roller has:
Since the amorphous silicon layer is provided, it has good releasability from toner, good heat resistance, and high mechanical strength, so material deterioration due to heating and cooling cycles and sliding scratches caused by sliding members such as separation claws and temperature detection sensors Will not stick. Further, even if a thick medium such as a passbook having a booklet, that is, a step is fixed, the fixing roller surface is not damaged. As a result, it can be used for a long period of time, and the life can be extended.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fixing device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a fixing roller according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a fixing device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a fixing roller according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a passbook printing apparatus equipped with the fixing device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Passbook printing device, 2, 4, 6, 7, 10 ... Conveyor roller pair, 3 ... Magnetic information reading / writing mechanism, 5 ... Image reading mechanism, 9 ... Fixing device, 17 ... Page turning mechanism, 18 ... Printing mechanism, 22 ... heat source, 23 ... separation claw, 24 ... pressure roller, 26 ... fixing cleaning member, 27 ... static elimination light source, 28 ... heat-resistant protective cover, 30 ... fixing roller, 30a ... cored bar, 30b ... surface protective layer, 30c: carrier injection blocking layer, 30d: photosensitive layer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Shibuya 1st Ikegami, Haruoka-cho, Owariasahi-shi, Aichi Prefecture Inside the Information Equipment Division of Hitachi, Ltd. Information Technology Division of Hitachi, Ltd.

Claims (3)

[Claims] 1. A fixing device, comprising: a fixing roller having a heat source; and a pressure roller in contact with the fixing roller, wherein the fixing device fixes the toner image on the transfer material by sandwiching the transfer material between the two rollers. A fixing device in which the release layer of the fixing roller is made of amorphous silicon. 2. A fixing device, comprising: a fixing roller having a heat source; and a pressure roller in contact with the fixing roller, wherein the fixing device fixes the toner image to the transfer material by sandwiching the transfer material between the two rollers. A fixing device comprising a light source for static elimination near the surface of the fixing roller, and a release layer of the fixing roller made of amorphous silicon having a photoconductive layer. 3. A passbook insertion / reception port, an information reading / writing mechanism for reading / writing information of the passbook inserted from the insertion / reception port, and judging a printing state of the passbook which has read the information. An image reading mechanism, a rotatable image carrier on which an electrostatic latent image is formed, and an electronic device including a charger, an exposure device, a developing device, a transfer device, a cleaner and a fixing roller disposed around the image carrier. A passbook printing apparatus comprising a photographic printing mechanism, a page turning mechanism for the passbook, and a transport roller for transporting the passbook between the respective mechanisms, wherein the release layer of the fixing roller is made of amorphous silicon. .