JPH01120592A - Fusing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fixing device for fixing an unfixed image used in an electrostatic recording type device.

(Prior Art) Conventionally, in a fixing device that fixes an unfixed image,
It is widely practiced to bring felt, sponge, or the like into contact with the fixing roller for cleaning or applying anti-offset liquid.

For example, in Japanese Utility Model Publication No. 59-37797, a liquid guiding member is pressed against a roller using a plurality of leaf springs, and an anti-offset liquid is uniformly applied to the roller.

However, when a plurality of pressing members such as leaf springs are arranged in the longitudinal direction of the roller, the following problem may occur.

This problem will be explained using FIG.

Reference numeral 1 denotes a heating roller having a heater 9 inside, and a pressure roller 2 is in pressure contact with this roller 1. 4 is a felt that has been impregnated with silicone oil, and 3 is a holder that holds this felt.The roller 1 is cleaned with this felt and is coated with silicone oil to prevent the occurrence of offset.

10 is a stay to which a plurality of leaf springs 8 are fixed.

(Problems to be Solved by the Invention) In this way, when the felt 4 is pressed against the roller by the leaf spring provided in a straight line in the longitudinal direction of the roller, if toner adheres to the felt 4, the adhesion The felt 4 and holder 3 were sometimes tilted in the direction of arrow A due to the influence of the toner.

This inclination causes the pressing force to fluctuate, causing unevenness in the amount of anti-offset liquid applied, and if this inclination becomes severe,
The pressing force became so great that it sometimes caused negative effects such as scratches on the roller surface.

In addition, there are variations in the dimensions of the leaf springs and the stem members that hold them, and as shown in Figures 5 and 6, due to these variations, the pressing position differs depending on the rotational direction of the roller, so the felt and There was also a risk that the holder would tilt, resulting in uneven product distribution.

(Means for Solving the Problems) The present invention that solves the above problems includes a rotating body for fixing an unfixed image, an abutting member that comes into contact with the rotating body, and a rotating body that a fixing device having a plurality of pressing members for pressing against the fixing device, wherein at least one of the pressing positions by the pressing members is provided at a different position with respect to the rotational direction of the rotating body. It is.

(Example of the invention) Embodiments of the present invention will be described below based on the drawings.

Note that the same numbers are given to members that perform the same functions.

FIG. 1 is a side view showing a fixing device according to an embodiment of the present invention.

The roller pair configuration is the same as the configuration in FIGS. 5 to 7, and by passing the recording material carrying an unfixed image between rollers 1 and 2, the heat generated by the heater 9 and the heat applied between both rollers are passed. The applied pressure fixes the image as a semi-permanent image.

The stay 7 holds the leaf spring groups 5 and 6. The pressing positions of the metal thin leaf springs 5 and 6 on the holder are distributed on both sides of the center of the felt 4 in the width direction (ie, the width in the rotational direction of the roller).

FIG. 2 shows the pressed positions by the plurality of leaf springs. Second
The figure is a view of the pressed position viewed from the direction of arrow B in FIG.

As shown in FIG. 2, the leaf spring groups 5, 6 are provided at different positions in the direction of rotation of the roller. Furthermore, -
A dashed dotted line C indicates the center of the width of the felt 4.

In this way, the rollers are pressed at different positions in the rotational direction, especially on both sides against the center of the width of the felt, which is the member to be pressed, which prevents the felt and the holder from tilting and ensures stability at all times. A certain amount of pressure can be obtained.

Further, since the pressing positions 5a, 5b, 6a, and 6b are different in the longitudinal direction, the pressure in the longitudinal direction can be further made uniform.

Fig. 3 is a top view showing another embodiment in which pressing is performed alternately at three locations.If the longitudinal pressing positions are arranged symmetrically with respect to the longitudinal direction of the roller, the pressure can be more uniformly applied in the longitudinal direction. The holder can be pressed, which is more preferable. Making the pressing positions symmetrical in the longitudinal direction of the roller in this manner is particularly effective when the reference position for conveyance of the recording material is at the center.

FIG. 4 shows an embodiment in which the number of pressing positions is further increased, which is effective when the roller is long.

The present invention has been described in detail above, but the present invention is not limited to felt as the material that comes into contact with the roller, but can also be used for sponges, webs, rollers, etc. for the purpose of cleaning or applying anti-offset liquid. It can be applied to everything.

Further, the material to be pressed is not limited to a leaf spring, and an elastic body such as a coil spring or elastic rubber can be used.

Further, the pressing position and number may be appropriately designed depending on the length of the roller, the hardness of the holder, etc., and are not limited to the above-mentioned embodiments.

(Effects of the Invention) As explained above, according to the present invention, the contact member such as felt or sponge that contacts the roller does not tilt and is always stable even if the product varies or the product is used over time. Pressure can be obtained, and a cleaning effect or an offset prevention effect can be stably obtained.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a top view showing the pressing position in the embodiment of Fig. 1, and Figs. 3 and 4 are top views showing other embodiments of the invention. Figures, Figures 5 to 7
Each figure is a side view showing a conventional fixing device. In the figure, 1 is a fixing roller, 2 is a pressure roller, 3 is a holder, 4 is felt, and 5, 6.8 are leaf spring groups. Man 1 figure

Claims (3)

[Claims] (1) A fixing device that includes a rotating body for fixing an unfixed image, a contact member that comes into contact with the rotating body, and a plurality of pressing members that press this contact member against the rotating body In the fixing device, at least one of the pressing positions by the pressing member is provided at a different position with respect to the rotational direction of the rotating body. (2) The fixing device according to claim 1, wherein the contact member is a member for cleaning the rotating body. (3) The fixing device according to claim 1 or 2, wherein the contact member is a member for applying offset prevention liquid to the rotating body.