JPH01294148A - Sheet conveyor for laser printer - 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 Application of the Invention] The present invention relates to a paper conveyance device for a laser printer.

In a laser printer that prints continuous paper at high speed, as shown in FIG.
It is common to use a process of heating and pressurizing at o.

At this time, the paper 10 is sent in the direction of the arrow in FIG. 1 by a motor (not shown) connected to the heating roll 40, but due to distortion of the paper, etc. ) may meander. In order to prevent this meandering, a suction blower 80 is provided, and the suction groove 30 of the heating plate 20 connected by a pipe 90 is made negative pressure, and the movement in the B direction is suppressed by sucking the paper 10 onto the heating plate 20. are doing. However, with the above configuration, if the paper is distorted in the width direction where there is no restraint between the heating plate and the back rotor, or if the paper is stopped on the heating plate for a long time, the paper may become distorted in the width direction. Since the amount of shrinkage changes, permanent damage such as wrinkles due to heat shrinkage occurs due to heating.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to eliminate paper wrinkles caused by paper distortion between the heating plate and the back roll during paper transport, and to remove the paper from the heating plate when paper transport is stopped. The purpose is to improve the stability of paper running by preventing wrinkles caused by heat shrinkage due to paper overheating.

[Summary of the invention]

When continuous paper is fed at high speed, meandering occurs near the heating roll, so suction grooves are usually provided on the heating plate to restrain the paper with a suction force above a certain level. The paper may become distorted in the unrestricted area in between, and the paper may wrinkle due to heat shrinkage when paper transport is stopped. Therefore, a buffer is provided between the heating plate and the back roll, and the buffer moves independently on the left and right sides in the width direction of the paper during paper transport, following the meandering of the paper and constantly applying tension to the paper.Furthermore, when paper transport is stopped, This device is designed to prevent paper wrinkles by removing the paper from the heating plate.

[Embodiments of the invention]

Embodiments of the present invention will be described using FIGS. 1 to 3. FIG. 1 is an enlarged perspective view of the vicinity of the heating plate of the paper conveyance device.
2 is a longitudinal sectional view of FIG. 1 when paper is being conveyed, and FIG. 3 is a longitudinal sectional view of FIG. 1 when paper conveyance is stopped. A buffer 60 is provided between the pair of heating rolls 40 and back rolls 50 and the heating plate 20. The buffer 6o is supported by elastic bodies 61 on the left and right sides in the middle direction of the paper, and is positioned above the tangential direction of the tip of the heating plate 20 when the paper is conveyed, so that tension can be applied to the paper at all times. . Furthermore, when paper conveyance is stopped, the heating roll 40 and the back roll 50 are separated, and the heating plate 70 connected to the back roll 50 is also lowered.

At this time, the suction blower 80 is stopped and the paper 10 is separated from the heating plate 20 and supported by the buffer. Next, just before the start of paper transport, the heating plate 20 adsorbs and preheats the lifted paper in preparation for paper transport. With the above configuration, tension is constantly applied to the paper between the back roll 50 and the heating plate 20 to prevent paper wrinkles from occurring.

In the above embodiment, the heating plate 2 is used instead of the buffer 6o.
Similar effects can be obtained by providing an elastic body 100 at the tip of the 0 as shown in FIG.

〔Effect of the invention〕

According to the present invention, since a buffer is provided between the back roll and the heating plate, when the paper has been stopped on the heating plate for a long time, the blower is turned off and the paper is lifted by the buffer to improve the heat distribution on the heating plate. It is possible to suppress paper wrinkles due to differences in the amount of paper shrinkage due to non-uniformity, and it is also possible to suppress fixing failures immediately before conveyance of the paper. Further, since tension is constantly applied to the paper between the back roll and the heating plate, wrinkles due to distortion of the paper can be suppressed, making it possible to provide a highly reliable paper conveying device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a paper conveyance device for a laser printer according to the present invention, FIGS. 2 and 3 are longitudinal sectional views of FIG. 1, and FIG. 4 is a paper conveyance device for a laser printer according to the prior art. FIG. 5 is a perspective view of the device and an enlarged sectional view of the tip of the heating plate showing a modification of the present invention. In the figure, 10 is paper, 2o is a heating plate, 30 is a suction groove, 40 is a heating roll, 5o is a back roll, 60 is a buffer, 61 is an elastic body, and 80 is a suction blower. Name of patent applicant Hitachi Koki Co., Ltd. '41■

Claims (1)

[Claims] 1. It has a heating roll and a back roll that heat and fix the toner on the paper, and has a heating plate equipped with a paper suction groove near the back roll, and the paper suction groove is connected to a suction blower. In the paper conveyance device of a laser printer, which is connected to each other, the heating plate attracts and preheats the paper, and the heating roll further heats and fixes the paper, a buffer is provided between the heating roll and the heating plate. Paper transport device for laser printers. 2. Paper conveyance in a laser printer according to claim 1, wherein the buffer has an elastic body so as to follow minute meandering of the paper that occurs when the paper is conveyed by the heating roll and the back roll. Device. 3. When paper conveyance is stopped, the suction blower is stopped, the paper is separated from the heating plate by the force of a buffer, and immediately before starting, the blower is started again to attract the paper to the heating plate. 2. A paper conveyance device for a laser printer according to item 2. 4. The paper conveyance device for a laser printer according to claim 3, wherein the buffer is located above the connection direction of the leading end of the heating plate when the paper is conveyed.