JP2003029481A - Paper transport device - Google Patents

Abstract

(57) [Summary] [Problem] To suppress the lifting of the leading edge of a sheet after transfer even for an upward curl caused by the environment in which the sheet is stored, a fiber direction, a continuous amount (a sheet thickness), and the like. A stable paper running is maintained even when the rear end of the paper jumps. SOLUTION: By providing a pressing member that regulates the paper edges at both ends in the paper width direction from the upper part of a paper transport path from a transfer section to a fixing device, the leading edge of the paper is lifted,
The jumping of the trailing edge of the sheet is suppressed and the toner image before fixing on the printing surface is regulated without being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device that stabilizes sheet traveling.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show a configuration according to the prior art.
A transfer unit 2 is provided below the photoconductor drum 1, and the paper 3 that has passed through the transfer unit 2 travels along a paper travel surface 5 of a paper transport path 4, and a heat roll 6 a and a backup roll of a fixing device 6 are provided. The toner is fixed on the sheet by heat and pressure by nipping to 6b.

However, the quality of the paper used for printing is
It behaves in various ways depending on the fiber direction, continuous amount (paper thickness), etc., and depending on the environment in which it is stored. In particular, a thin sheet that has absorbed moisture may be curled before use, and a particularly large curl is involved when printing on the back surface after passing through fixing once. In such a sheet, the leading edge 3a of the sheet may float and run without passing through the transfer section 2 and being attracted to the air suction hole 8a formed in the conveyor belt 8 of the sheet conveying path 4. If the leading edge 3a of the sheet rises in this way, it cannot be nipped between the heat roll 6a and the backup roll 6b of the fixing device 6, and the leading edge 3a of the sheet rolls up as shown in FIG.

[0004]

SUMMARY OF THE INVENTION According to the present invention, the quality of the paper, the fiber direction, the continuous amount (paper thickness) and the like, and the upward curl caused by the environment in which the paper is stored causes the rising of the leading edge of the paper after transfer. Further, the purpose of the present invention is to hold the paper even when the trailing edge of the paper jumps up and to ensure stable paper running.

[0005]

In order to achieve the above object, the present invention provides a paper edge pressing member for restricting the paper edges at both ends of the paper from above the paper transport path after passing through the transfer portion.

When viewed from the upstream side of the sheet conveyance, the shape of the ridge line contacting the edge of the sheet is a figure-eight member, and the sheet is arranged so as to pass under the figure-eight ridge line. The width of the lowermost portion of the figure eight of the paper edge pressing member is wider than the width of the paper and does not come into contact with the paper edge pressing member as long as the paper is normally conveyed. If the leading edge of the sheet floats, the edge of the sheet comes into contact with the eight-sided ridge of the sheet edge pressing member to prevent the sheet from rising more than a predetermined amount. Since the paper edge contacts the figure-eight ridge of the paper edge pressing member, the toner image on the printing surface of the paper before fixing is not damaged. Further, the sheet is provided with an inclination so as to guide the leading edge of the sheet to the traveling surface of the sheet conveyance below so as not to be caught when the leading edge of the sheet contacts the sheet edge pressing member. Also in this case, the ridge line at the leading edge of the paper contacts the paper edge pressing member, but the portion of the paper that passes through the bottom of the ridge line after being guided downward and contacts the paper edge is the paper edge, and does not damage the toner image. Absent.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a front view of this embodiment. FIG. 2 shows the present embodiment as seen from the upstream side of the sheet (photoconductor 1 side).

In FIG. 1, a paper edge pressing member 7 is installed in the area of the paper transport path 4 from above the paper 3 to the paper running surface 5. Paper edge pressing member 7
Is provided with an inclination so as to guide and guide the paper to the paper traveling surface 5 even if the paper leading edge 3a comes into contact with the paper. Further, in the embodiment, the material of the paper edge pressing member 7 is P having a thickness of 0.188 mm.
By using the ET film, the impact can be mitigated even when the leading edge 3a of the sheet collides and the trailing edge 3c of the sheet contacts.

In FIG. 2, the paper edge pressing member 7 covers the upper part of the paper in a region wider than the width of the paper 3. Further, an eight-shaped ridge line 7a that is inclined from the outer side to the inner side of the paper edge pressing member 7 is provided. Therefore, even if the paper 3 floats upward, the paper edge 3b does not come into contact with the eight-sided ridge line 7a and damage the toner image on the printing surface of the paper 3 before fixing, and the floating above a predetermined level is restricted. Can be done.

[0010]

INDUSTRIAL APPLICABILITY The present invention suppresses the rising of the leading edge of the paper after transfer even with respect to the quality of the paper, the fiber direction, the continuous amount (paper thickness), and the upward curl caused by the environment in which the paper is stored. It is possible to secure stable paper running by suppressing the jumping up of the rear edge.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sheet conveying device that is an embodiment of the present invention.

FIG. 2 is a schematic diagram as viewed from the upstream side of the sheet (photoconductor 1 side) in FIG.

FIG. 3 is a schematic view of a conventional sheet conveying device.

FIG. 4 is a schematic diagram showing a state in which a paper jam occurs without being able to enter a fixing device due to lifting of the leading edge of the paper in the related art.

FIG. 5 is a side view of the upstream side of the sheet (photoreceptor 1) in the related art.
It is the figure seen from the side).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 2 ... Transfer part, 3 ... Paper, 3a ... Paper front end, 3b ... Paper edge, 3c ... Paper rear end, 4 ... Paper transport path, 5 ... Paper running surface, 6 ... Fixing machine, 6a ... Heat roll, 6b ... Backup roll, 7 ... Paper edge pressing member, 7a ... Eight ridge line, 8 ... Conveyor belt.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junji Shirakawa             Hitachiko, 1060 Takeda, Hitachinaka City, Ibaraki Prefecture             Machine Co., Ltd. F term (reference) 2H072 AB07 CA06 CB08                 3F101 FA01 FB05 FB07 FC11 LA01                       LB03

Claims (5)

[Claims] 1. A fixing device for transferring a toner image developed as an electrostatic latent image on a photoconductor onto a cut sheet, and then fixing the toner transferred by heat and pressure through a conveyance path of the cut sheet onto the sheet. In the paper transport device of the electrophotographic device, which has a paper feed path between the photoconductor and the fixing device, regulates the paper edges at both edges of the paper that are parallel to the paper traveling direction from the paper surface on which the transfer toner is placed. A sheet conveying device characterized by being provided with a member for controlling. 2. The member for regulating the edges of the paper in the width direction of the paper has a shape of a figure 8 in contact with the paper edge when viewed from the upstream side of the paper conveyance, and the shape of the paper is eight. 2. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus passes under a character-shaped member. 3. The width of the lowermost part of the figure eight of the member for regulating the edges of the paper in the width direction of the paper is wider than the width of the paper, and the paper is against the paper running surface of the paper transport path between the photoconductor and the fixing device. In a state where the sheet is lifted within a predetermined amount and travels almost along, the eight-sided ridge line of the member that regulates the edges of the paper at both ends does not come into contact, and when the sheet is lifted and runs a predetermined amount or more from the paper running surface, the eight-sided ridge line is formed. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is provided on the conveying path so as to be in contact with each other. 4. A member for regulating the edges of the paper in the width direction of the paper is provided with a slope for guiding the paper back to the paper running surface even when the paper floats above the running surface and comes into contact with the leading edge of the paper. The sheet conveying device according to claim 1. 5. The sheet conveying apparatus according to claim 1, wherein the member for pressing the edges of the sheet in the sheet width direction is made of an elastic member.