JPH03243556A - Skew correction mechanism for cut paper - Google Patents

Abstract

PURPOSE:To correct skew so as to be lessened by providing a cut paper press member for the tip end of a paper guide located in the vicinity of the apex of slackening formed in such a way that the tip end of a cut paper to be carried is pushed against a registration roller. CONSTITUTION:When a cut paper 6 fed by a carrying roller 14 is skew, its one corner comes up to the nip 10 of a registration roller 15, at a stop, to form slackening 16. Slackening 16 is enlarged as the cut paper 6 is carried, the neighborhood of its apex comes in contact with a cut paper press member 20 installed on the tip end of a paper guide 21, and the cut paper is subjected to force by which the other corner of the cut paper 6 is pushed into the nip 10 so that skew is thereby corrected. Push-out force of the carrying roller 14 is so effectively applied to an end of the cut paper 6 as to enhance skew correc tion effect.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a skew correction mechanism for cut paper used in printing machines such as laser beam printers and copying machines.

[Conventional technology]

The prior art will be explained with reference to FIGS. 5 to 10, taking a laser beam printer as an example. FIG. 5 is a side view of the laser beam printer. In FIG. 5, a photosensitive drum 1 is charged by a charger 2, and a latent image is formed by a laser beam 3. In FIG. Toner 12 is applied to the latent image by a developing device 4 to form a visible image. The cut paper 6 fed by the paper feed roller 9 is sent to the transfer section of the photosensitive drum 1 via the registration roller 15 which is driven intermittently by the transport roller 91, and the toner on the photosensitive drum 1 is transferred by the transfer corotron 5. 12 is transferred onto the cut paper 6. After the transfer, the cut paper 6 is neutralized by a peeling corotron 11 and peeled off from the photosensitive drum 1. Thereafter, the cut paper 6 is conveyed by a conveyor belt 7, guided to a fixing device 8, and fixed thereon.

The toner 12 remaining on the photosensitive drum 1 is cleaned and collected by a cleaner 13. The cut paper 6 fed by the paper feed roller 9 is often skewed to some degree for various reasons. If the toner image is transferred at the transfer section while being skewed, the toner image will be transferred obliquely relative to the cut paper 6. Therefore, it is necessary to correct the skew of the cut sheet 6 before the transfer section. FIG. 6 is a plan view of a conventional skew correction mechanism for cut paper 6;
The figure is a side view of FIG. 6. As shown in FIG. 6, if the cut paper 6 is skewed upward to the right, the cut paper 6
The right tip corner 18 of reaches the registration roller 15 first. The registration roller 15 can be driven intermittently, and when the right end corner 18 of the cut paper 6 reaches the registration roller 15, the registration roller 15 is stopped. Therefore, as shown in FIG. 7, the right leading edge 18 of the cut sheet 6 waits at the registration roller 15 until the left leading edge 19 of the cut sheet 6, which has been delayed by the dimension A, reaches the registration roller 15. There is. In FIG. 7, 21 is an upper paper guide, and 22 is a lower paper guide. FIG. 8 is a plan view of the conventional skew correction mechanism for cut paper 6 in a state different from that shown in FIGS. 5 and 6, and FIG. 9 is a side view of FIG. After reaching the registration roller 15,
Furthermore, the cut paper 6 is fed by a predetermined amount by the conveyance roller 9, and a slack 16 is formed in the cut paper 6 in front of the registration roller 15. In this state, the leading edge 17 of the cut paper 6 is corrected to be almost parallel to the registration roller 15. Immediately after this, by driving the registration roller 15, the skew of the cut sheet 6 is substantially corrected and the cut sheet 6 is sent to the transfer section. Also, the first
As shown in FIG. 0 as a side view of another conventional example, there is also an example in which a cut paper-time stop member 23 equipped with a solenoid 24 and a spring is used in place of the registration roller 15.

[Problem to be solved by the invention]

The conventional example had the following problems. In other words, taking an example of an upward skew to the right, first, the right leading edge 18 of the cut paper 6 reaches the registration roller 15, and then the left leading edge of the cut paper 6 is adjusted only by the pushing force from the conveying roller 14. 19 is also pushed into the contact area between the pair of rollers of the registration roller 15 (hereinafter referred to as the nip 10), but because the right end corner 18 of the cut paper 6 hits the nip 10 of the registration roller 15 first. , a slack 16 occurs in the cut paper 6, and due to the slack 16, the extrusion force from the conveyance roller 14 is not transmitted to the left edge angle 19 of the cut paper 6, and the skew correction rate (the dimension before correction becomes A after correction) 'The rate of correction to the dimension; (A-
There was a problem that A') AX100%) was low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cut paper skew correction mechanism that reduces the skew of cut paper in a printing apparatus such as a laser beam printer or a copying machine that uses cut paper.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a cut paper skew correction mechanism.

A cut paper feeder comprising: a conveyance roller that conveys the cut paper; a registration roller that starts driving when the leading edge of the cut paper reaches the nip; and a paper guide that guides the cut paper to the registration roller. In the feeding mechanism, from when one leading edge of the cut paper reaches the nip due to the skew of the cut paper until the leading edge completely reaches the nip,
A cut paper pressing member is provided at the tip of the paper guide to contact a portion between the vicinity of the top of the slack of the cut paper caused by being pressed against the registration roller by the conveyance of the conveyance roller, and the conveyance roller. It is characterized by:

[Function] In the present invention, the extrusion force from the conveyance roller is not transmitted to the leading edge of the cut paper due to the slack that occurs after the leading edge of the skewed cut paper hits the registration roller, and the skew correction effect is small. , a cut paper pressing member between the registration roller and the conveyance roller is installed at a position where it contacts between the top of the slack of the cut paper and the conveyance roller, so that the push-out force of the cut paper from the conveyance roller can be applied as much as possible to the cut paper. The skew correction efficiency was increased by transmitting the information to the tip edge.

〔Example〕

Embodiments of the present invention are shown in FIGS. 1 to 4.

1 and 3 are plan views showing one embodiment of the cut paper skew correction mechanism of the present invention, and FIGS. 2 and 4 are
Figures 1 and 3 are side views of Figures 1 and 3, respectively; As shown in these figures, in the present invention, a cut paper pressing member 2 is provided between the conveyance roller 14 and the registration roller 15.
0 is set. When the cut paper 6 is transported by the transport roller 14, if there is a skew, for example, the right edge angle 1
8 reaches the nip 10 of the registration roller 15, but since the registration roller 15 is stopped, a slack 16 occurs in the cut sheet 6. Sagging 16
When it reaches a certain amount or more, it comes into contact with the cut paper pressing member 20,
Further, as the slack 16 increases, the cut paper 6 is subjected to a force in the direction of the arrow in FIG. 4 due to the reaction force from the cut paper pressing member 20. Therefore, a force acts on the leading edge 17 of the cut paper 6 so as to push it into the nip 10 of the registration roller 15. For example, as shown in Figure 1,
Taking the case of an upward skew to the right as an example, after the right edge corner 18 of the cut paper 6 reaches the nip 10 of the registration roller 15, the cut paper 6 becomes slack 16;
By pressing this slack 16 with the cut paper pressing member 20, a force is applied to the left tip corner 19 of the cut paper 6 to push it into the nip 10 of the registration roller 15, and the tip edge 17 of the cut paper 6 is pressed against the registration roller 15.
It is corrected parallel to the axis of , as shown in FIG. The position of the cut paper pressing member 20 is the slack 16 of the cut paper 6.
The position where the reaction force acts on the registration roller 15 side, that is, from the vicinity of the top of the slack 16 of the cut paper 6 to the conveyance roller 9 is effective. In this embodiment, the conveyance roller 14 is provided between the paper feed roller 9 and the registration roller 15 to cause slack 16 in the cut paper 6. The effect of this can be obtained. For example, the conventional skew correction effect was only able to correct the skew of 5 to 6I to about 2 to 3 m (correction effect of 50%), but the present invention corrects it to 0.5no or less (correction effect of 90% or more). It is possible.

The skew correction effect can be significantly enhanced.

〔Effect of the invention〕

According to the present invention, the following effects can be achieved.

(1) Since the leading edge of the cut paper is forcibly pushed into the nip of the registration roller, it is possible to correct the skew regardless of the amount of skew.

(2) Conventionally, when the skew amount exceeds the specified skew amount of the device, the device would be stopped, but now the skew amount can be corrected to within the specified skew amount.

[Brief explanation of drawings]

1 and 3 are plan views showing different states of an embodiment of the cut paper skew correction mechanism of the present invention, and FIGS. 2 and 4 are side views of FIGS. 1 and 3, respectively. Figure 5 is a side view of the laser beam printer, Figure 6 is a side view of the laser beam printer.
8 are plan views of the conventional cut paper skew correction mechanism in different states, FIGS. 7 and 9 are side views of FIGS. 6 and 8, respectively, and FIG. FIG. 2 is a side view of a conventional example. 1 is a photosensitive drum, 2 is a charger, 3 is a laser beam, 4 is a developer, 5 is a transfer corotron, 6 is a cut paper 7 is a conveyor belt, 8 is a fixing device, 9 is a paper feed roller 11 is a peeling corotron,
12 is a toner, 13 is a cleaning machine, 14 is a conveyance roller, 15
is the registration roller, and 16 is the slack.

Claims (1)

[Claims] 1. A transport roller that transports the cut paper, a registration roller that starts driving when the leading edge of the cut paper reaches the nip, and a registration roller that guides the cut paper to the registration roller. In a cut paper feeding mechanism including a paper guide, the skew of the cut paper causes one leading edge of the cut paper to reach the nip until the leading edge completely reaches the nip. , a cut paper pressing member is provided at the tip of the paper guide to contact a portion between the vicinity of the top of the slack of the cut paper and the conveyance roller, which is caused by being pressed against the registration roller by the conveyance of the conveyance roller; A cut paper skew correction mechanism featuring: