JPS61183678A - Fixing roller and fixing device having said roller - Google Patents

Abstract

PURPOSE:To prevent the generation of wrinkle of a recording material by providing a groove part which has been inclined in the direction of the end part of a roller from the center part of the roller, on a base body, and providing an elastic layer on the base body having its groove part. CONSTITUTION:A fixing roller 4 has a roller base body 1 having grooves 2, 2a being orthogonal to the axial direction of the roller toward both ends of a roller shaft from the center related to the longitudinal direction of the roller, and an elastic layer 3 which has been joined and covered to the peripheral surface of this roller base body 1. As for the peripheral surface of the fixing roller 4, the surface is smooth, and shows a roughly uniform diameter, and it is deformed elastically at least by a very small quantity by pressure. A recording material generates no wrinkle since the elastic layer 3 operates so as to make pressure escape in the direction of the end part of the roller along the grooves 2, 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field to which the invention pertains) The present invention relates to the field of a fixing roller that is often used in fixing devices and a fixing device equipped with the same.

(Prior Art) Conventionally, this type of fixing device uses a fixing roller for fixing a toner image on a recording material such as paper or Mylar sheet by applying heat and pressure or using only pressure. However, since pressure is applied to the recording material, deformation (for example, wrinkles or curls) of the recording material itself may occur. In order to solve this problem, it has been proposed in the past to make the outer shape of the roller convoluted. However, although these rollers are effective to a certain extent for a certain paper size, the recording materials used in recent years come in a wide variety of sizes, so they cannot be accommodated for each size and may suffer from wrinkles. This is not satisfactory as it may not be possible to prevent the occurrence of

Furthermore, there are many different materials for recording materials, and in particular, ordinary plain paper made of pulp material comes in various thicknesses and sizes, and its moisture absorption state tends to change depending on environmental conditions. It is difficult to obtain a chain-shaped roller that satisfies the above conditions, and a fixing roller and fixing device that satisfies these conditions is desperately needed.

In general, the manufacturing and processing methods for forming the chain-shaped rollers require highly advanced technology, and in reality, there are almost no methods that can stabilize accuracy and variation.

(Objective and Summary of the Invention) The present invention aims to solve the above-mentioned conventional problems, and provides a fixing roller that is practically satisfactory for the type of recording material (size, thickness, material) and capable of stable fixing conveyance. The present invention provides a fixing device.

The present invention provides, as a first aspect, a substrate (which may be a single substance or a composite), a groove portion perpendicular to the viscosity direction of the substrate L provided on the surface of the substrate, and an elastic layer provided on the surface of the substrate so as to cover the groove portion. A second aspect of the present invention provides a fixing roller having at least one of a pair of fixing rollers that nip and convey a recording material.
The present invention is characterized by a fixing device using the fixing roller of the invention.

The first invention has the effect of preventing the deformation of the recording material as much as possible regardless of the type of recording material, and the second invention has the effect of preventing the deformation of the recording material and jamming during constant recording. play.

(Explanation of Examples) Embodiments of the present invention will be described below with reference to the drawings.

The grooves provided on the basic surface of the fixing roller of the present invention, which are perpendicular to the direction of the substrate mother ship, are approximately determined by the width t in the roller axis direction and the depth to the crawler surface. The position is approximately determined by three variables, including the directional spacing T between the grooves.

This groove part makes the amount of deformation of the elastic body larger at the ends than at the center, thereby allowing the acting force concentrated at the center of the recording material to escape toward the ends of the recording material. In the case of a rubber surface or a resin surface, injection or wrapping can be easily and accurately formed by easy means such as molding.

FIG. 1 shows the fixing roller side, FIG. 2 shows an example of the fixing device, and FIGS. 3 to 6 show examples of only the base body.

The fixing roller 4 of the embodiment shown in FIG. 1 is a roller having grooves 2, 2a on the circumferential surface symmetrically with respect to the roller center O, extending from the center 0 in the longitudinal direction of the roller to both ends of the roller axis and perpendicular to the roller mother ship direction. The roller has a base 1 and an elastic layer 3 bonded and coated on the circumferential surface of the roller base 1.

The circumferential surface of the fixing roller 4 has a smooth surface, exhibits a nearly uniform diameter, and is elastically deformed at least slightly by pressure. In this sense, the elastic layer 3 is suitably made primarily of rubber, resin, or a mixture of rubber and resin. In addition, since it is better for the roller base l to have relatively rigidity, it is suitable to use a metal material or one whose fully bent surface is coated with a resin material or a thin rubber material. The grooves 2 and 2a are provided with a groove width t which is a constant groove interval T, which is made smaller on the end side, and the fixing roller 4 has a shape f'E' (the edge 1 is filled with a part of the layer 3). In Fig. 1, only the elastic layer 3 is shown in cross section, and the roller base body is shown as viewed from above.

By using the recording material in this way, the adhesive layer 3
This fixing roller acts to release pressure toward the roller ends along the grooves 2 and 2a, so wrinkles do not occur, and even when using various recording materials, this fixing roller dramatically reduces wrinkles compared to conventional methods. Or there were almost no wrinkles.

FIG. 2 shows an embodiment of the second invention of the present invention, in which the fixing roller 4 is a roller having the configuration shown in FIG. It rotates at the same time and is provided on the side that comes into contact with the unfixed image.

Reference numeral 5 denotes a pressure roller that presses against the fixing roller 4 and is located below the fixing roller 4. The groove of the base 1 of the fixing roller 4 rotates so as to move toward the end of the fixing roller 4 at a position facing the pressure roller. The fixing roller 4 and the pressure roller 5 apply a pressure sufficient to fix the unfixed image by a pressure means (not shown).

A release liquid applying member 7 and a separation claw 6 for separating the recording material are in contact with the circumferential surface of the fixing roller 4, and an inlet guide member 8 is provided on the recording material entrance side and an exit guide member 9 is provided on the recording material discharge side. It is being The pressure roller 5 is made of a copper pipe la whose surface is hardened by induction hardening and hard chrome processing.

As described above, in the pressure fixing device configured to apply the fixing roller 4 explained with reference to the example in FIG. Even without processing, it is possible to prevent wrinkles on the recording material during fixing, regardless of the type of recording material (including material, size, thickness, etc.). Of course, the coating thickness of the outer layer of the fixing roller 4 changes depending on the pressure of pressure fixing, but the surface may not be straight, but may be processed into a slightly inverted crown shape of about 5 to tog.

According to the second national standard, the operation of the blade device during fixing will be explained in more detail as follows.

The recording material is conveyed between the fixing roller 4 and the pressure roller 5, and is held between the rollers. Here, the elastic layer 3 on the surface of the fixing roller 4 is allowed to deform from the center area toward both ends because the spacing between the grooves 2.2a is narrower on the end side, so that the elastic layer 3 on the surface of the fixing roller 4 appears to be It has a vector component force that deforms toward the end. Therefore, roller 4
, 5, the recording material is slightly pulled toward both ends of the roller by this vector component, so that it does not become wrinkled toward the center.

Next, FIGS. 3 to 7 show more effective examples of the structure of the groove portion which constitutes the main part of the present invention. These are number 1.
Second 0 which is a configuration that can be used in common to each invention
The description will be simplified to refer to the drawings.

In the example shown in FIG. 3, the fixing roller base 1 has a groove depth h
is constant, the width t of the groove is set to increase toward the end (t□<t1<t2<t3<t4), and the interval T between adjacent grooves is set to (T i > T 2 > T 3 > T
a) It was done.

The main feature of this example is that the width of the groove is larger at the ends than at the center.This feature allows the amount of deformation of the elastic layer 3 at the ends of the roller to be large, which prevents the occurrence of wrinkles. can be more effectively prevented. Furthermore, since this example also has the features of the example in FIG. 1, the wrinkle prevention effect can be further enhanced and the types of recording materials can be further diversified.

In the example shown in FIG. 4, the fixing roller base l is designed so that the width of the grooves and the interval between the grooves are constant, and the depth of the grooves becomes deeper toward the end (h□<hl<h2<h3< h4) The feature of this example is that the depth of the groove is deeper at the end than at the center. This feature also increases the effect of preventing wrinkles because the grooves become deeper at the ends of the roller, making the upper elastic layer more susceptible to change.

5 and 6 combine the features of the examples in FIGS. 1 to 3 to further improve the effect.

In the fixing roller base 1 shown in FIG. 5, the depth h of the groove gradually increases from the center of the roller to the end of the roller (ho
<ht<h2<h3<h4), and the width E of the groove portion gradually increases (tQ<t1<t2<t3<t4).

Further, the fixing roller l in FIG. 6 has a groove width t constant,
The depth h of the groove is gradually increased toward the end (ho<hl
<h2<h3<h4<h5<ho), and the width T between the grooves is T1, which is smaller than To in the TO1 end region in the central region. Decoupling is not limited to the above example,
The effect will increase if various combinations are included.

FIG. 7 is an explanatory diagram of the configuration of an embodiment of an electrophotographic copying machine to which the fixing device of the present invention is applied. In FIG. 7, reference numeral 32 denotes a document mounting table made of a transparent member, which reciprocates in the direction of the arrow. 22
is a converging light transmitting body, which transmits an optical image of the original image on the original storage table 32 onto the photosensitive drum 23 through a slit a.

The photosensitive drum 23 rotates in the direction of the arrow. 24 is a corona charger that charges the photosensitive drum uniformly; 25 is a developer that charges the photosensitive drum uniformly with an electrostatic latent image formed by exposing the uniformly charged photosensitive drum to a light image using the converging light transmitter 22; Visualize the image.

On the other hand, the transfer paper P is fed onto the drum surface by a paper feed roller 26 and a register roller 27, and the image on the drum is transferred by a transfer body charger 28. Thereafter, the transfer paper is separated from the drum by the separating means 13 and sent to the fixing device IO through the guide 29. The toner image on the transfer paper is pressure-fixed by the pressure fixing device IO, and the transfer paper is transferred to the discharge roller 11.
is discharged onto the tray 12.

The toner remaining on the photosensitive drum 23 is removed by cleaning means 1.
Dropped and recovered by 4.

Reference numeral 15 is an illumination means for exposing the original, and reference numeral 16 is a filter such as a heat ray absorption filter. A drive motor 21 drives at least one of the pressure fixing rollers 101 and 102, and keeps the fixing rollers 101 and 102 in rotation.

Apparatus 10 as a pressure fixing device in which the present invention is particularly effective
1 is a relatively rigid pressure fixing roller 101 having an offset prevention layer 101b made of a resin coating on the surface of a metal roller having any of the grooves shown in FIGS. 1, 3 to 7. (Embodiment of the fixing roller of the present invention) and a relatively rigid pressure fixing roller 102 having an offset prevention layer 102b made of a resin material applied to the surface 102a of a normal smooth metal roller. This pressure fixing roller 101 is located on the side of the recording material P in the gravity direction so as to be in contact with the back surface of the recording material P, which is opposite to the toner image ill holding surface of the recording material P. The roller 101 is the lower frame 1
07, and the roller 102 is rotatably supported by an upper frame 106 which is movably connected to the lower frame 107 at a common fulcrum 109.

Reference numeral 108 denotes a pressure means that generates sufficient pressure to fix the toner image between the rollers 101 and 102 by interlocking the upper and lower frames 106 and 107. Apply a pressure of 8 kg/cm or more. Reference numeral 21 denotes a motor for driving the fixing roller 101 having a groove, which rotates a gear 103 attached to the shaft of the roller 101 via a driving force transmission path 30 to directly apply a drive to the fixing roller 101 . The pressure fixing roller ], 02 rotates following the pressure fixing roller 101 during this description.

The embodiment shown in FIG. 8 shows a fixing device that more effectively employs the roller of the present invention, the first feature of which is that the roller having the grooves is provided on the back side of the recording material opposite to the toner image. , the second feature thereof is that it is provided with means for driving the roller having the groove portion not by driven rotation but by direct transmission of driving force. These features may be provided separately, but in this example, they are provided together, so it goes without saying that the effect is further improved.This first feature is that whether the fixing roller having the y1 portion is driven or driven, In a state in which the lower recording material is pulled or squeezed toward the end of the roller, and in a state in which the toner image itt is supported on the upper side,
Since it is pressed against the upper roller 102, there is almost no risk of unnecessary effects on the toner image, and a stable fixed image can be reliably obtained without deforming the recording material. The second feature is that the elastic layer of the roller having the grooves deforms slightly in the direction of the roller end, making the effect more reliable when removing the cause of wrinkles, and preventing deformation when the recording material is easily deformed or deformed. It is possible to deal with both cases where it is difficult to wrinkle, and to prevent wrinkles more reliably. In other words, the acting force generated on the recording material can be more reliably released toward the end of the roller.

Therefore, since this embodiment has both of these features, it is possible to provide extremely stable recording material conveyance and excellent fixed images.

Another embodiment in which the other configuration shown in FIG. 8 is added to the above embodiment will be briefly described below. In this example, a fixing roller having the grooves as described above is used for both rollers of the pair of fixing rollers. In particular, in this example, the driving force from the motor 21 is also applied to the fixing roller 102 through the driving force transmission path 31. 104. Therefore, in this explanation, the smooth metal roller surface 102a described above is a metal roller serving as a base having the grooves. In this way, both of the pair of pressure-contact fixing rollers that sandwich and transport the recording material during fixing are provided with the above-mentioned grooves so that the recording material escapes from the center of the roller toward the ends of the roller, resulting in a more reliable wrinkle prevention effect. can be played.

In this case, it goes without saying that the direction of the groove at the pressure contact part of the pair of fixing rollers is the same for the fixing rollers 101 and 102, and as the rollers rotate, the groove at the pressure contact part tends to escape toward the end. appears to move.

(Effects of the Invention and Supplementary Explanation of the Invention) As explained above, the present invention has a groove section in the base of the fixing roller that is inclined from the center of the roller toward the end of the roller, and as an upper layer of the base having the groove. Since it has an elastic layer, wrinkles on the recording material can be largely prevented.

Incidentally, as the substrate in the present invention, a metal material is preferable, but
The roller may be one in which a metal material is coated with a resin material, or a roller with an elastic surface.The groove portion in the present invention may be a roller having a shape that allows the elastic layer to easily deform from the center of the roller to both ends of the roller. Any groove may be used, and it is preferable to have 2 (I or more) symmetrically, but the groove does not need to be symmetrical. Also, the elastic layer 3 may be a surface layer that can be elastically deformed even by a small amount during use. good.

The present invention also includes modifications of any combination of the above-described embodiments based on the technology of the Ikemizu invention (high-pressure contact pressure fixing roller, etc.).
It is all-inclusive.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment including a partial cross section of the fixing roller of the present invention, FIG. 2 is an explanatory diagram of an embodiment of the fixing device of the present invention, and FIG.
6 to 6 are explanatory views of embodiments of grooves of a base body, which are the main parts of the present invention. FIG. 7 is an explanatory diagram of a two-armor device to which the present invention is applied, and FIG. 8 is an explanatory diagram of another embodiment of the fixing device of the present invention. 1 is the roller base (or base body), 2.2a is the groove, 3 is the elastic layer, and t is the width of the groove. T is the distance between the grooves, h is the depth of the grooves, θ is the angle, B is the arrow indicating the rotation direction, and 21 is the motor.

Claims (9)

[Claims] (1) A fixing roller characterized by a base body, an elastic layer provided on the surface of the base body, and a groove portion provided between the base body and the elastic layer to increase the amount of deformation of the elastic layer from the center toward the ends. . (2) The fixing roller according to claim 1, wherein the groove portion has a depth increasing toward an end of the fixing roller. (3) The fixing roller according to claim 1, wherein the number of the grooves increases toward the end of the fixing roller. (4) In a fixing device having a pair of fixing rollers for nipping and conveying a recording material and fixing an unfixed image on the recording material, one of the pair of fixing rollers has a base and an elastic layer provided on the surface of the base; A fixing device comprising a fixing roller provided with a groove between a base and an elastic layer to increase the amount of deformation of the elastic layer from the center toward the ends. (5) A patent claim in which the fixing device is a pressure fixing device that fixes the unfixed image under pressure, and the fixing roller with the groove is provided on the side opposite to the one side of the recording material that supported the unfixed image. The fixing device according to item 4. (6) The fixing device according to claim 4 or 5, wherein the groove portion increases in depth toward the end of the fixing roller. (7) The fixing device according to any one of claims 4 to 6, wherein the number of the grooves increases toward the end of the fixing roller. (8) The fixing device according to any one of claims 4 to 7, wherein the fixing roller having the groove portion is a drive roller that rotates by receiving a driving force from a drive source. (9) The other roller of the pair of fixing rollers is a fixing roller that, like the one roller, has a base, a groove provided on the surface of the base and perpendicular to the direction of the roller mother ship, and an elastic layer provided on the surface of the base. Claims 4 to 8 are
The fixing device according to any one of paragraphs.