JPS6086579A - Fixing device - Google Patents

Abstract

PURPOSE:To remove a contamination which is accumulated between an offset preventing device and a heating roller, and also to execute exactly a fixing operation by providing a contamination removing member on the offset preventing device, and also making a power supply switch conduct by the offset preventing device when it contacts to the heating roller. CONSTITUTION:When an offset preventing device 37 is separated from a heating roller 20, moved in the axial direction and drawn out, a contamination removing member 32 provided on the device 37 slides on the surface of the roller 20, and a contamination which is accumulated between the offset preventing device and the heating roller is removed. On the other hand, when the offset preventing device 37 is made to contact to the roller 20, a power supply microswitch is made to conduct by a lever of the device 37, and the fixing operation is executed exactly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention provides an apparatus having a detachable offset prevention device for applying offset prevention liquid to a fixing rotation roller, in which the offset prevention device and the fixing rotation roller are connected together. The present invention relates to a fixing device that removes dirt accumulated during the process and performs an appropriate fixing operation.

(b) Prior Art In electrostatic recording devices such as electrophotographic copying machines and facsimile machines, an electrostatic latent image of fcFi electrical information is formed on the original based on reflected light or electrical information signals obtained by exposing and scanning the original. is formed on a photoreceptor or dielectric material, the static latent image is developed into a visible image, and this visible image is transferred to recording paper and then fixed to form a recorded image. Figure 1 is an electronic photograph 1
This shows the schematic configuration of a 1v copying machine, in which an illumination lamp 2 illuminates the *tlt original MG on a document table 1 that reciprocates in the direction of the arrow, and a rotating drum 3 rotates in the direction of the arrow to reflect light from the document G. The original G is projected onto the photoreceptor 3a of the photoreceptor 3a.
forms an electrostatic latent image. To operate the rotating drum 3, a band WL pole 4 for uniformly charging the photoconductor 3a, a developing device 5, a transfer VIIL pole 6, a separation electrode 7, a static elimination electrode 8, and a cleaning device 9 are sequentially installed. Placed 〇 Shizuka l! The Ura image is developed into a visible image by a developing device 5, and the visible image is transferred by a transfer electrode 6 onto recording paper P fed by a conveying device i11 from a paper feeding device 10 such as a cassette.

After the transfer, the recording paper P is separated from the photoreceptor 3a by the separation electrode 7, conveyed to the fixing device 13 by the feeding device 12, fixed there, and discharged onto the paper discharge tray 14.

The fixing devices used in electrophotographic copying machines include a non-contact fixing method that heats and fixes the toner using waste energy such as infrared rays, and a non-contact fixing method that heats and fixes the toner using energy such as infrared rays. There is a contact fixing method that heats and fixes the toner using heat.The fixing device using the latter method includes a heating roller that has a built-in heater and is driven by a drive source, and a pressure roller that rotates in pressure contact with the heating roller. A heat roller type fixing device is generally known, which is composed of a heating roller and heat-fuses the toner image onto the recording paper using heat from a heated part.This method has good thermal efficiency and therefore consumes little power. It is widely used because it has advantages such as being able to fix 6 consecutive times.

In this hot roller type fixing device, the toner on the recording paper adheres to the heating roller, causing a so-called offset phenomenon, which stains the recording paper, and the recording paper tends to wrap around the heating roller due to the adhesion of the offset toner. There was a problem.

Therefore, in order to solve this problem, a method has long been proposed in which a heating roller that comes into direct contact with the toner/image-bearing surface of the recording paper is coated with an off-cera prevention liquid such as silicone oil (Japanese Patent Publication No. 41-21430). issue). As a method of applying the anti-offset liquid to the heating roller, for example, a heating roller 2 with a built-in heater 20a as shown in FIG.
0, the silicone oil 23 in the oil tank 22 is supplied via an oil-impregnated member 21 such as felt, or the silicone oil is supplied from the oil tank through the oil-impregnated member by bringing an oil application roller into contact with a heating roller. There is a type that supplies (Japanese Patent Application Laid-Open No. 54-37752).

However, providing an oil tank, an oil-containing member for applying oil, a roller, and the like to the fixing device increases the size of the entire device, which goes against the recent trend toward miniaturization of devices. Also, these oil tanks and oil application parts r! Usually, it is fixed to the fixing device with screws or the like, so it takes time and effort to remove it when replacing it, which is undesirable in terms of handling.

Therefore, as shown in Figure 3, rounding is used to solve this problem.
An offset prevention liquid-impregnated member 24 made of felt impregnated with a certain amount of offset prevention liquid such as silicone oil is used. A cleaning member 25 made of felt for cleaning the surface of the heating roller 20 is integrally held by a holding member 26 to constitute an offset prevention device 27, and a guide plate 26a on the holding member 26 is connected to the rail 28 above the heating roller 20. It has been proposed that the entire offset prevention device 27 is detachable from the fixing device by being able to slide in the axial direction (in the direction of the arrow) of the heating roller 20 within the fixing device. In this case, in order to replace the offset prevention liquid supply member 24 and the cleaning member 25, after taking out the entire fixing device 30 from the copying machine main body 29 as shown in No. 4gJ (a), There is a method of replacing the offset prevention device 27 by pulling it out in the axial direction while the offset prevention device 27 is opened.

In addition, as shown in FIG. 4(b), the copying machine main body 29 is made of a 2-part A9 structure that can be divided into upper and lower parts, and when the top cover 30g of the fixing device 3o is opened in the divided state (shown by the solid line), the offset prevention device is installed. There is a way to pull out the w27 and replace it. In addition, in a fixing device in which a cleaning device is attached to the heating roller to clean dirt caused by toner and paper powder scattered above the heating roller, Fi-
There is a method of moving the cleaning device upward to release the pressure between the cleaning device and the heating roller, and then pulling the cleaning device forward and replacing it.
No. 661).

By the way, it is quite time-consuming to take out the entire fixing device 1130 from the military aircraft main body 29 or to divide the copying machine main body 29 into two. Also, during fixing, the heating roller 2° is heated to a high temperature of about 160 to 200 C by an internal heater, so when the temperature of the heating p-roller 20 is not yet sufficiently low, the top cover 30a of the fixing device 30 is closed. There is a risk of getting burned when opening the offset prevention device 27 and replacing it. Against this, an anti-offset device! Even if a side wall is not provided on the front side in the axial direction so that the fixing device 27 can be pulled out to the front side in the axial direction, if the offset prevention device 27 is removed or installed without opening the top cover 30a of the fixing device 30, the offset prevention liquid may be impregnated. Since the surfaces of the member 24 and the cleaning member 25 rub against the surface of the heating roller 20, there is a risk of damaging the surface of the heating roller 2o. In addition, if the surfaces of the anti-offset liquid impregnated member 24 and the cleaning member 25 become dirty due to the toner, paper dust from recording paper, or carrier particles in the developer mixed with the anti-offset liquid, the anti-offset liquid impregnated member 24 and the cleaning member 25 may be impregnated with the anti-offset liquid for a long time. Dirt accumulates on J between the member 24, the cleaning member 25, and the heating roller 20, and the dirt accumulates on the heating roller 2.
0 and the recording paper is heated by the 0-ra 20 and the pressure roller 31.
There is a problem that it gets dirty when passing between.

(c) Object and Structure of the Invention The present invention has been made in view of the above-mentioned points, and includes a pair of rotating fixing rollers that rotate in pressure contact with each other, and a detachable device that applies an anti-offset liquid to at least one of the rotating rollers. In a fixing device having an offset prevention device capable of preventing offset, the purpose is to remove dirt accumulated between the offset prevention device and the rotating p-ra and to ensure proper fixing operation. A dirt removal member is provided at one end in the longitudinal direction, and when the offset prevention device fc is installed and removed, only the dirt removal member takes a first position in contact with the surface of the rotating roller, and during installation, it is in pressure contact with the surface of the rotating roller. A switch means is provided which is turned on by the offset prevention device when the offset prevention device assumes the second position tt, and the offset prevention device can be pulled out toward the other end in the longitudinal direction at the first position. When the offset prevention device is pulled out, the dirt removing member slides on the rotating roller to remove dirt on the surface of the rotating p-roller, and the switch means is connected to conduction a'.
The fixing device is configured to be able to operate when the fixing device is in the fixing state.

) Example The present invention will be explained below based on the drawings.

5(a) and 5(b) respectively show a front view and a side view of the fixing device according to the present invention. Rather, the offset prevention device M27 can be pulled out in front of the heating roller 20 in the axial direction. In addition, an offset prevention device n and a heating p
- A scraping blade 32 made of silicone rubber with a thickness of about 1 m is provided for removing dirt accumulated between the roller 20 and the roller 20. Fixing device @3 with offset prevention device 1/27
0, as shown in FIG. When the offset prevention device 27 is pushed into the predetermined position of the fixing device 30 in this way, the offset prevention device 1j27ij (Fig. 5 middle)
As shown in FIG. 2, it is pressed against the surface of the heating roller 20. Next, when removing the offset prevention device 27 from the fixing device, scrape off the offset prevention device @ 27 as shown in FIG. After raising it to the point where it makes contact, pull it out in the direction of the dashed arrow.

Next, the attachment/detachment mechanism and the attachment/detachment method of the offset prevention device will be specifically explained.

6(a) and 6(b) respectively show the attachment/detachment mechanism of the fixing device according to the present invention in two different positions, and FIG.
A) and (B) show these attachment/detachment mechanisms in Figure 6 (A).

(b) This is the bacteria seen from the direction of arrow A. In each figure, the offset prevention device 27 shown in FIG.
are integrally held by a holding member 33,
The offset prevention device 27 has a guide bin 35 provided on its upper surface through a long hole 34 extending in the longitudinal direction of the guide member 34.
By engaging with a, it is possible to slide in the longitudinal direction. Furthermore, two links 36, 36 are attached to the left and right side walls of the guide member 34 so as to be rotatable at point B, and these links 36 are attached to the L-shaped fixed member 37 at point C. It is mounted so that it can rotate. A pin 36a is installed at point B of the two links 360 that are attached to the side wall of one of the four links 36 (the right side in FIG. 7 (a), center), and the pin 36a and the fixing member 37 A spring 38 is stretched between the two. A lever 39 for removing the Vi is provided on the front side in the longitudinal direction of the guide member 34 (on the right side in FIG. 6).

Considering the case where a used offset prevention device is replaced with a new offset prevention device using such an attachment/detachment mechanism, in order to remove the used offset prevention device 27 from the fixing device, the lever 39 is moved in the direction of the solid line arrow with a finger. When the link 36 is pulled, the link 36 rotates clockwise, but when it rotates beyond a certain angle, it assumes the position shown in FIG. 6(a) (the position corresponding to FIG. 5(a)) due to the action of the spring 38. In this state, the offset prevention liquid impregnated member 24 of the offset prevention device 27, the cleaning member 25Fi, and the heating roller 2
0, but the tip of the scraping blade 32 provided at the back end of the offset prevention device 27 in the longitudinal direction (left side in the sixth cabinet) comes into contact with the surface of the heating roller 20. Therefore, when the entire offset prevention device 27 is pulled out to the front side in the longitudinal direction, the dirt accumulated between the offset prevention device 27 and the heating roller 20 is removed by the scraping blade 32.

Next, in order to install a new offset prevention device, leave the attachment/detachment mechanism in the state shown in FIG.
a to fully engage the offset prevention device 27. At this time as well, the tip of the scraping blade 32 comes into contact with the surface of the heating roller 20. When the back end of the offset prevention device 27 is pushed to a predetermined position, if the lever 39 is further pushed in the direction of the dashed arrow, the link 36 rotates counterclockwise, and the guide member 34 and the offset prevention device 2
7 approaches the heating roller 20, but when the link 36 rotates beyond a certain angle, it automatically rotates under the action of the spring 38 and moves to the position shown in FIG. 6 (opening) (corresponding to FIG. 5 (opening) That is, the anti-offset liquid impregnated member 24 and the cleaning member 25 are placed in pressure contact with the surface of the heating roller 20.

In this way, when removing a used offset prevention device, the scraping blade 32 removes the dirt that has accumulated between the offset prevention device R27 and the heating roller 20, so that even after long-term use, the recording paper remains No contamination. Next, the operation of the fixing device when the offset prevention device is attached and detached will be described.

FIG. 8 shows a state in which the offset prevention device 270 shown in FIG. 3 is attached to the fixing device according to the present invention, as seen from the back side in the axial direction, and FIG. 9 (A).

(Opening) shows only the back end of the cross-sectional view taken along line DD in FIG. As shown in FIG. 9(a), a protrusion 41 to which a scraping replenisher 32 is attached is provided at the back end of the offset prevention device ff127o in the axial direction. When it is pushed in to a predetermined position, it presses the contact 42m of the microswitch 42 provided on the main body of the device, as shown in FIG. 9(b). The fixing device can now operate. On the other hand, when the back end of the offset prevention device 27 has not reached the predetermined position, it does not come into contact with the contact 42a of the microswitch 42, as shown in FIG. It becomes inactive.

10(a) and 10(b) show a light sensor 43 which is composed of a light emitting element and a light receiving element instead of the microswitch 42, and a protruding piece provided at the back end in the axial direction of the offset prevention bag wi27. 44 (to which the scraping blade 32 is attached) is used to turn on and off the optical sensor 43. When the offset prevention device 27 has not reached the predetermined position of the fixing device, the protruding piece 44 is located away from the optical sensor 43 as shown in FIG. Since there is no fixing device, the fixing device becomes inactive.

On the other hand, when the offset prevention device 27 is pushed to a predetermined position, the protrusion 44
Since it is inserted into the Fi optical sensor 43, light is blocked and the fixing device can be operated by the output from the optical sensor 43.

In this way, the fixing device is operated only when the offset prevention device 27 is at the predetermined position of the fixing device, so the fixing operation is performed without the offset prevention device 27 installed and without the offset prevention liquid being applied to the heating roller 20. Therefore, it is possible to prevent the offset phenomenon and the wrapping of the recording paper around the heating a-roller 20.

In this embodiment, a microswitch or an optical sensor is used to detect that the offset prevention device is attached to the fixing device, but a magnetic method may also be used for detection. Further, in this embodiment, silicone rubber is used for the scraping blade, but the scraping blade is not limited to this, and any material such as a sponge that does not damage a part of the glue surface may be used. Further, in this embodiment, a fixing device provided with an offset prevention device having a cleaning member has been described, but the present invention can also be applied to a fixing device provided with only a cleaning member.

(E) Detailed Description of the Invention As described above, the present invention includes a pair of rotating fixing rollers that rotate in pressure contact with each other, and a detachable offset prevention device that applies offset prevention liquid to at least one of the rotating rollers. In the fixing device, a dirt removal member is provided at one end in the longitudinal direction of the offset prevention device, and the offset prevention device assumes a first position where only the dirt removal member contacts the surface of the rotating roller during installation and removal. is in a second position in pressure contact with the surface of the rotating roller, and is provided with a switch means which is turned on by the offset prevention device when the offset prevention device assumes the second position;
The offset prevention device can be pulled out toward the other end in the longitudinal direction at the first position, and when the offset prevention device is pulled out, the dirt removing member slides on the rotating roller to remove dirt on the surface of the rotating roller. Since the fixing device is enabled to operate when the switch means becomes conductive, the recording paper will not become dirty even after long-term use, and the offset phenomenon and recording paper wrapping around the rotating roller will not occur. can be prevented. Furthermore, since the offset prevention device can be attached and removed simply by operating a lever that can be operated from the outside, the offset prevention device can be easily replaced. Furthermore, since the rotating roller is hardly exposed when the offset prevention device is replaced, the offset prevention device can be replaced safely. Furthermore, since the offset prevention device does not rub against the surface of the rotating roller when the offset prevention device is replaced, the surface of the rotating roller is not damaged.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an electrophotographic copying machine, FIGS. 2 and 3 are schematic diagrams of different conventional fixing devices, and FIG. 4 (A) is a 3V! Fixing device fWM shown in J A diagram showing the main body of the fWM copying machine taken out, Figure 4 A diagram showing a state in which the main body of the copying machine with Fi 2 division structure is divided into two parts, Figure 5
Figure (A) is a front view and side view of the fixing device according to the present invention showing the offset prevention device installed and removed. 6(A) and 6(B) are side views showing the attachment/detachment mechanism of the fixing device according to the present invention at two different positions, and FIG. 7(A) is shown in @6(A). 71 is an end view of the attachment/detachment mechanism as seen from the direction of arrow A; FIG. 71 is an end view of the attachment/detachment mechanism shown in FIG. 91 and 10 are views showing different embodiments of the detection mechanism for detecting the installed state of the offset prevention device. 13.30... Fixing a-ra, 20... Heating roller,
21...Oil-containing member, 22...Oil tank, 23.
... Silicone coil, 24 ... Offset prevention liquid impregnated member 725 ... Cleaning member, 27 ... Offset prevention device, 28 ... Rail, 31 ... n■ pressure roller, 32 ... Scraping Take blade, 33... Holding member, 34... Guide member, 35... Guide pin, 3
6...Link, 37...Fixing member, 38...Spring, 39...Lever, 41...Protrusion, 42...Micro switch, 43...Light sensor, 44...Protrusion Patent applicant for one-piece patent Roku Konishi Photo Industry Co., Ltd. Agent Patent attorney Hiroshi Suzuki Figure 1 Figure 2 F 1 Figure 3 [I4 times (A) (0) Figure M8 Figure 9 Figure 10

Claims (2)

[Claims] (1) In a fixing device including a pair of rotating fixing rollers that rotate in pressure contact with each other and a removable offset prevention device that applies offset prevention liquid to at least one of the rotation rollers, the longitudinal direction of the offset prevention device A dirt removal member is provided at one end, and the offset prevention device assumes a first position in which only the dirt removal member contacts the surface of the rotating roller during mounting and removal, and is in pressure contact with the surface of the rotating roller during mounting. a second position, and a switch means is provided which is turned on by the offset prevention device when the offset prevention device takes the second position; When the offset prevention device is pulled out, the dirt removing member rubs on the rotating p-roller to remove dirt on the surface of the rotating roller, and the switch means is in a conductive state. A fixing device characterized in that the fixing device is enabled to operate when the fixing device is activated. (2) The fixing device according to claim 1, wherein the offset prevention device includes a cleaning member on the upstream side when viewed in the rotational direction of the rotating roller.