JPH0546847U - Paper skew correction device for paper transport system - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to reduce paper skew and variations in print start position. A sheet skew correction device for a sheet transport system, which includes a rotatable stopper 5A that abuts a sheet 2 that has been conveyed and that corrects the sheet skew. It is characterized in that it is formed by denting with a V-shaped inclined surface. [Effect] The paper that comes into contact with the stopper is always positioned at the V-shaped dented fixed position of the stopper.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a paper skew correction device for a paper transport system.

[0002]

[Prior Art]

 FIG. 3 shows a paper feeding system of the laser printer. As shown in the figure, the sheets 2 deposited on the sheet hopper 1 are picked by the pick belt 3 and sent to the continuously rotating transport belt 4. The leading edge of the sheet 2 conveyed by the conveyor belt 4 comes into contact with the stopper 5 and temporarily stops to correct the skew. After that, in synchronization with the toner image on the photosensitive drum 6, the stopper 5 is rotated around the shaft 7 and released, and the paper 2 starts running again and is conveyed to the photosensitive drum 6 by the pinch roller 8. The toner image is transferred onto the sheet 2 at the transfer station 9, fixed at the fixing station, and discharged to a stacker (both not shown).

[0003] The configured paper feed system paper skew correction process of such in so that shown in Figure 4, the paper tip is conveyed theta ₁ ⁰ tilted by the conveyor belt 4 is in contact with the stopper 5a, D point Is rotated in the direction of the arrow in the figure (see a in the figure). Then, the other end of the sheet comes into contact with the stopper 5b, and the skew is corrected (see FIG. 9B). After that, in synchronization with the toner image on the photosensitive drum drum 6, the stopper 5 (both see FIG. 3) starts rotating, and the sheet 2 starts running.

[0004]

[Problems to be solved by the device]

 In the above conventional technique, the variation in the paper arrival time from the start of rotation of the stopper to the transfer is the variation in the print start position.

That is, as shown in FIGS. 5 and 6, when the position where the leading edge of the sheet abuts the stopper 5 changes in the vertical direction, the print start position changes. That contact with the sheet 2 in the point E of the stopper 5 starts rotation stopper 5, the angle passes through a scan stopper 5 when it becomes theta ₂ ⁰ (see FIG. 5). In contrast contact with the sheet 2 in the point F of the stopper 5 passes through the stopper 5 when the angle of the stopper 5 becomes theta ₂ ⁰ greater than theta ₃ ⁰ (see FIG. 6).

As described above, due to the difference in the vertical position at which the sheet 2 comes into contact with the stopper 5, the sheet arrival time from the start of the rotation of the stopper 5 until the sheet reaches the transfer point changes, and the printing start position Also changes. Further, if the stopper 5a, 5b (see FIG. 4) changes the contact position in the vertical direction, there is a problem that paper skew occurs.

The present invention has been made in view of the above points, and an object of the present invention is to provide a paper skew correction apparatus for a paper transport system capable of reducing variations in paper skew and printing start position. Is.

[0008]

[Means for Solving the Problems]

 The above-mentioned object is achieved by forming the stopper by denting the contact surface of the paper with a V-shaped inclined surface with respect to the paper feeding direction.

[0009]

[Action]

 Since the above-mentioned means is provided, the sheet that comes into contact with the stopper is always positioned at a fixed V-shaped concave position of the stopper.

[0010]

【Example】

 Next, the present invention will be specifically described with reference to examples.

[Embodiment 1] FIGS. 1 and 2 show an embodiment of the present invention. Note that the same parts as those of the prior art are denoted by the same reference numerals, and the description thereof will be omitted. In this embodiment, the stopper 5A is formed by denting the contact surface of the sheet 2 with a V-shaped inclined surface with respect to the direction in which the sheet 2 is fed. By doing so, the sheet 2 contacting the stopper 5A is inevitably positioned at a fixed V-shaped recessed position of the stopper 5A, which depends on the difference in the vertical contact position of the leading edge of the sheet with the stopper 5A. It is possible to obtain a paper skew correction device for a paper transport system that eliminates variations and can reduce variations in paper skew and print start position.

That is, as shown in FIG. 1, the paper 2 contacting the point A on the lower side of the stopper 5A advances to the point B of the recessed portion of the stopper 5A along the inclined surface of the stopper 5A. Then stop. Further, as shown in FIG. 2, the sheet 2 abutting the point C on the upper side of the stopper 5A enters the point B of the recessed portion of the stopper 5A along the inclined surface of the stopper 5A and stops. In this way, the sheet 2 that comes into contact with the upper and lower positions of the stopper 5A always comes to be located at the concave point B of the stopper 5A, so that the sheet is transferred to the transfer point after the stopper 5A starts rotating. Variations in arrival time are eliminated, and variations in paper skew amount and printing start position are reduced.

As described above, according to this embodiment, since the contact position of the leading end of the sheet with the stopper is constant, it is possible to reduce the variation in the print start position and the skew amount.

[0014]

[Effect of the device]

 As described above, according to the present invention, the stopper is formed by denting the contact surface of the paper with the V-shaped inclined surface with respect to the paper feeding direction. It is possible to obtain a paper skew correction device for a paper transport system which can be positioned at a fixed V-shaped concave position of a stopper and which can reduce variations in paper skew and printing start position.

[Brief description of drawings]

FIG. 1 is a side view showing a process in which a sheet is positioned at a certain position indented by a stopper according to an embodiment of a sheet skew correcting device for a sheet conveying system of the present invention.

FIG. 2 is a side view showing a process in which a sheet is positioned at a fixed position where the stopper is depressed according to the embodiment.

FIG. 3 is a side view showing a paper transport system of a conventional laser beam printer.

4A and 4B are views showing sheet skew correction by a conventional sheet skew correction device of a sheet conveying system, FIG. 4A is a top view showing a state before sheet skew correction, and FIG. 4B is a top view showing a state after sheet skew correction. It is a figure.

FIG. 5 is a side view showing a process until a sheet passes a stopper by a conventional sheet skew correcting device of a sheet conveying system.

FIG. 6 is a side view showing another example of the progress of the sheet by the sheet skew correction device of the conventional sheet transport system until the sheet passes through the stopper.

[Explanation of symbols]

 2 ... paper, 5A ... stopper.

Claims (1)

[Scope of utility model registration request] 1. A paper skew correction device for a paper transportation system, comprising a rotatable stopper for correcting the paper skew of a transported paper by abutting the stopper.
A sheet skew correction device for a sheet conveying system, wherein a surface of the sheet abutting is formed to be dented with a V-shaped inclined surface with respect to a sheet feeding direction.