JP2003270884A - Paper sheet cooling system for paper sheet folding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a jamming due to blowing of cooling air and the deposition of toner on piled-up printing surfaces due to cooling insufficiency. <P>SOLUTION: In a paper sheet folding device, a continuous printing paper sheet with folding perforations, on which the toner is thermally fixed, is folded so that the front and the back of the paper sheet are alternately folded and stacked on a table, a paper sheet upper surface stacked on the table is detected by a sensor and the table is lowered for a fixed amount. In the device, a plurality of blowers and ducts for blowing the cooling air to the paper sheet are disposed, the ducts are arranged side by side respectively in a paper sheet length direction and the strength of blown air from the respective ducts is made different. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet cooling method for a sheet folding device in an electrophotographic printing apparatus including a fixing device that uses heat to fix toner on the sheet to the sheet.

[0002]

2. Description of the Related Art An electrophotographic printing apparatus exposes print data on the surface of a photoconductor having photoconductivity, generates a potential difference on the surface of the photoconductor, and develops a toner which is powder ink. Transfer the toner from the surface to the printing paper and heat it with a fixing device to melt the toner and fix it on the printing paper.
The printing paper is folded by a paper folding device.

The sheet folding device generally has a plurality of sets of sheet cooling blowers and ducts for cooling the heat remaining on the sheet heated by the fixing device.

The plurality of sets of sheet cooling blowers and ducts are arranged in the sheet length direction, and the amount of air blown from each duct is the same as the air velocity.

[0005]

In the conventional paper cooling method of the paper folding device, the air flow rate and air speed from the respective ducts arranged in a plurality of sets are equal, and when the air is blown at a strong wind speed and air volume, the sewing machine is operated. There is a problem that the paper is largely lifted at the edge in the paper length direction near the eye, and the folding of the perforation by the T-belt is obstructed to cause a jam.
In addition, there is a problem that when the air is blown at a low wind speed and flow rate, the toners on the overlapping print surfaces are fused due to insufficient cooling.

It is an object of the present invention to prevent jamming due to blowing of cooling air and toner adhesion on overlapping printing surfaces due to insufficient cooling.

[0007]

SUMMARY OF THE INVENTION The above-mentioned object is to fold a stack of continuous printing paper with a fold perforation on which toner is heat-fixed by alternately folding it on the table and stacking it, and detecting the upper surface of the paper stacked on the table. In the electrophotographic printer that detects the table by a certain amount and lowers the table by a certain amount, a plurality of blowers and ducts for sending cooling air to the sheet are arranged, and the ducts are arranged side by side in the sheet length direction. It is characterized by giving different strength to the air blown from,
Achieved by the paper cooling method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. In the embodiment shown in FIG. 1, the printed paper 1 is folded along the perforations of the paper by the swinging swing fins 2, and the perforations folded by the T-belt 3 are pressed against the table 4 side. When a certain amount of the sheet 1 is deposited on the table 4, the upper surface of the sheet is detected by the optical sensor 5 and the table 4 is lowered by a certain amount.

The sheet 1 is heated by a fixing device (not shown) and is conveyed onto the table 4 while maintaining a high temperature of about 80 ° C. If the temperature of the sheet 1 is not cooled to 65 ° C. or less, the overlapping print surfaces Due to the problem that the toner is fused, the blowers 6, 7, 8 for sheet cooling and the ducts 9, 10, 11 are arranged.

The paper cooling blowers 6, 7, 8 and the ducts 9, 10, 11 are arranged in the paper length direction, and the air blown from the central duct 10 is strong and the ducts 9, 11 at both ends are strong. The blast from is weakened.

With this structure, strong air is blown at the central portion of the sheet length direction that does not hinder folding at the perforations, and weak air is blown at the edge portion near the perforations that inhibits folding. As a result, it is possible to prevent jamming and also to prevent toner from adhering to the overlapping print surfaces due to insufficient cooling.

[0012]

As described above, according to the present invention, it is possible to prevent a jam due to the blowing of air in the cooling section and a welding of toner on overlapping printing surfaces due to insufficient cooling.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a side view showing an embodiment of the present invention.

[Explanation of symbols]

1 is a sheet, 2 is a swing fin, 3 is a T-belt, 4 is a table, 5 is an optical sensor, 6 is a blower, 7 is a blower,
8 is a blower, 9 is a duct, 10 is a duct, and 11 is a duct.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Motohiro Kuroda             Hitachiko, 1060 Takeda, Hitachinaka City, Ibaraki Prefecture             Machine Co., Ltd. F term (reference) 2H072 FB01 FB06 HA04                 3F054 AA01 AB02 AC02 BA02 BD02

Claims (2)

[Claims] 1. A continuous printing sheet having folding perforations, to which toner is heat-fixed, is alternately folded and accumulated on a table, and the upper surface of the sheet accumulated on the table is detected by a sensor to keep the table constant. In a paper folding device for lowering the amount, a plurality of sets of blowers and ducts for sending cooling air to the paper are provided, and the ducts are arranged side by side in the paper length direction, and the air blown from each duct has a different strength. A paper cooling method characterized by. 2. The paper cooling system according to claim 1, wherein the air blown from each of the ducts is strongest in the central portion in the paper length direction and weakened toward the folding perforations.