JPH01214552A - Sheet carrying device - Google Patents

Abstract

PURPOSE:To put back protruding parts following to carrying a sheet to inside with a rib for making it possible to continue carrying without any trouble by providing a guide rib guiding the sheet to carrying direction on slightly outside of a guide or a neighboring single base line. CONSTITUTION:In a case of being a carried sheet S of a small size and rather thick, moreover deformed due to both face or multiple copying, when the sheet is abutted to a slant face 5a on an inlet guide 5 from on a carrying belt 3, if one end D on center side of sheet top end is contacted earlier as compared with other end point, the sheet S receives moment in a direction of an arrow mark E around one end D as a center according to difference in carrying resistance. And outside point F of rear end is turned so as to protrude to outside of a base line C. The outward movement of the sheet S is limited by a guide rib 5c, and the protruding part of the sheet is put back in the inside direction as the sheet S is carried on the carrying belt 3. Carrying is thereby continued without trouble and also sheet S is treated for fixing treatment on a fixing roller 1 and a pressure roller 2.

Description

DETAILED DESCRIPTION OF THE INVENTION C) Industrial Application Field The present invention relates to a sheet conveying device used in copying machines, printers, facsimile machines, etc., and particularly to a sheet conveying device suitable for use as an entrance guide of a fixing device. More specifically, the present invention relates to a sheet conveying device based on one side.

(B) Conventional technology Conventionally, as shown in FIG. 4, a sheet conveying device in the entrance guide portion of a fixing device has a fixing roller 1 and a pressure member that is pressed against the fixing roller 1 with a predetermined urging force. An entrance guide S that guides the roller 2, the conveyor belt 3, and between the nip portion A of the fixing port ~1 and the pressure roller 2 and the conveyor belts 1~3.
', and the entrance guide 5' is connected to the nip part A.
It has an upwardly inclined surface 5'a to project the sheet upwardly.

Therefore, the sheet conveyance device guides the sheet conveyed from the conveyance belt 3 to the inclined surface 5'B of the entrance guide 5', so that the conveyance belt 3 side of the guide 5 is located below the sheet conveyance surface. A recess 5'b is formed, and the conveyor belt 3
The sheet is guided by the inclined surface 5'a of the entrance guide 5', and the leading edge of the sheet touches the fixing roller 1 above the nip portion A.
Then, based on the rotation of the fixing roller 1 in the direction of the arrow, the leading edge of the sheet is sent to the nip portion A, and the fixing roller 1
and pressure roller 2, and the image on the sheet is fixed.

(c) Problems to be Solved by the Invention Recently, due to the diversification of use in copying machines and the like, thick and small-sized paper such as postcards is often transported, and for this reason, the above-mentioned sheet transport device In this case, it is necessary to raise the slope 5'a of the input logger and the door 5', thereby making the opening 5'b deep, in order to maintain the sheet conveyance force by the conveyor belt 3.

However, when transporting particularly small and thick sheets of paper, if the leading edge of the paper is deformed due to duplex or multiple copying, the leading edge of the paper may come into contact with the inclined surface 5'a of the entrance guide from the conveying belt 3. The resistance received is different on the left and right sides,
This may cause the paper to be shaken considerably. This is noticeable due to the steep angle ratio of the inclined surface 5'a of the input guide 5', and in the case of one-sided reference, the paper may protrude from the conveyance path and cause a jam.

Therefore, an object of the present invention is to prevent the sheet from being swayed by the guide, thereby solving the above-mentioned problems.

B) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances, and for example, as shown with reference to FIGS. 1 and 2, the conveyance path (11) is and in the sheet conveyance path,
An inclined surface (5a
) A sheet conveying device (
10) is characterized in that a guide rib (5C) is provided at or near the guide (5) slightly outside the one-sided reference line (C) for guiding the sheet in the transport direction.

(E) Effect Based on the above configuration, the sheet has its - side as the reference line (C)
along the sea 1-transport path (11). On this occasion,
When a small thick sheet with a deformed tip comes into contact with the inclined surface (5a) of the guide (5), a moment is generated due to the difference in resistance and the sheet is swung left and right. In this case, as shown in Fig. 2, a moment is applied in the direction shown by the arrow (E) centering on one end CD of the leading edge of the sheet, and the other end of the trailing edge of the sheet is swung so as to protrude from the reference line (C). Then, the sea 1 side end comes into contact with the guide rib (5C) and is prevented from swinging greatly, and
As sheet conveyance progresses, the protruding portion is guided by the guide rib (5C) and returned to the inside, and conveyance continues without any problem.

Note that the above-mentioned symbols in parentheses do not limit the configuration in any way.

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

Sheet transport device 1 at the inlet of the fixing device in a copying machine
0, as shown in FIGS. 1 and 2, a fixing roller 1, a pressure roller 2 that is in pressure contact with the fixing roller 1 with a predetermined urging force, a large number of conveyor belts 3...-1, and a fixing roller. 1
and an entrance guide 5 that guides between the nip portion A of the pressure roller 2 and the conveyance bell 1-3, and the conveyance path 11 has a paper feed reference line that is a one-sided reference. The sheet S is conveyed along C. Further, the entrance guide 5 directs the sheet upwardly with respect to the nip portion A.
~ It has an inclined surface 5a having an upward slope so as to protrude, and on one side of the entrance guide 5 there is a guide rib 5b for guiding the sea +-S in the transport direction slightly outside the reference line C. is formed.

Since this embodiment has the above configuration, the conveyor belt 1
By traveling in the direction of the arrow -'3, the sheet 1-S placed on the conveyor belt 3 is conveyed along the paper feed reference line C on one side thereof. Furthermore, the tip of the sheet S is connected to the guide 5.
The leading edge of the sheet contacts the fixing roller 1 above the nip portion A along the inclined surface 5a. Then, based on the rotation of the fixing roller 1 in the direction of the arrow, the seal l-
The leading edge of the sheet is sent to the nip portion A, and the sheet is pressed against the fixing roller 1 and the pressure roller 2 to fix the image on the sheet.

If the sheet 1-S to be transported is small and thick like a postcard, and as shown in Figure 3, it is deformed due to double-sided copying or multiple duplication, etc., as shown in Figure 2. From the conveyor belt 3 to the inclined surface 5a of the entrance guide 5
When one end of the center side of the leading edge of the sheet comes into contact with the other end earlier than the other end, due to the difference in conveyance resistance, the sheet S will move around one end I) and move in the direction of the arrow E by a moment 1-.
Swing it so that the outside F of the rear end does not protrude outside the reference line C. However, the outward movement of the sheet S is restricted by the guide ribs 5C, and as the sheet 1-S is conveyed by the conveyor belt 3, the protruding portion of the sheet S is guided by the guide ribs 5c and returned inward. The conveyance continues without any problem, and the sheet 1-S is also fixed by the fixing roller 1 and the pressure roller 2.

Further, when the sheet receives a moment in the opposite direction of arrow E, the sheet 1- is swung inward and continues to be conveyed without any trouble.

In the above embodiment, the guide rib 5c is provided on the entrance guide 5, but it may be provided on other parts of the conveyance path near the guide. However, it goes without saying that the present invention can also be applied to other sheet conveying devices such as the registration roller entrance portion.

(G) As described in detail, according to the present invention, the guide rib (5C) is provided slightly outside the one-sided reference line (C) in the vicinity of the guide 1: (5) or the guide. Even if - is deformed, conveyance can be continued without any problem and conveyance defects can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a sheet conveying device according to the present invention, and FIG. 2 is a plan view thereof. In addition, FIG. 3 is a perspective view showing an example of a deformed sheet. FIG. 4 is a diagram showing a conventional example. 1.Fixing roller, 2..-Pressure roller, 3..Conveyance Belt, 5.
- (Entrance) guide, 5a゛ inclined surface, 5C - guide rib, 10 - sheet transport device, 11 - sheet transport path, A nip section, C - one side reference line.

Claims (1)

[Scope of Claims] 1. A sheet conveyance device comprising a sheet conveyance path with one side as a reference, and a guide having an inclined surface in the sheet conveyance path that slopes upward in the sheet conveyance direction, comprising: A sheet conveyance device, characterized in that a guide rib for guiding the sheet in the conveyance direction is provided slightly outside the one-side reference line at or near the guide.