JPH0616257A - Printer - Google Patents

Abstract

PURPOSE:To provide a printer enabling the positive conveyance of a sheet to a printing mechanism part in the flawless state by moving auxiliary rollers while rotating by the rotary shafts thereof in such a way as to be parallel to a second feed roller, and holding the sheet by the auxiliary rollers and the second feed roller for conveyance. CONSTITUTION:A feed roller 3a is driven in a direction A, and a sheet 1a is deformed in the bent state between the feed roller 3a and a claw 9 provided at the end part in the sheet feed direction. When the largest deformed part of the sheet 1a reaches the place of a feed roller 3b provided on a paper feed case 2, auxiliary rollers 7 provided at two places are respectively driven in the directions of arrow marks B, B' around auxiliary roller driving shafts 8 so as to come in contact with the feed roller 3b. At this time, the sheet 1a is held between the feed roller 3b and the auxiliary rollers 7 and taken up, and at the same time, the sheet end part is released from the claw 9. The sheet 1a is then fed to a printing part while being held by the rotatory driving of the feed roller 3b and auxiliary rollers 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly, to a paper feed mechanism in a printer that supports printing of standard size paper.

[0002]

2. Description of the Related Art In a conventional paper feeding mechanism, a paper 1a set in a paper feeding case 2 as shown in FIG. 3 is rotationally driven by a paper feeding roller 3 rotatably mounted on a chassis (not shown) (arrow). And the frictional force of the contact surface between the paper feed roller 3 and the paper. At this time, since the end portion of the sheet 1a in the sheet feeding direction (arrow F direction) is pressed by the claw 9 provided in the sheet feeding direction (arrow F direction), the sheet 1a indicated by the dotted line is fed to the sheet feeding case 2 Deforms and deforms above. When the paper feed roller 3 is driven to rotate further,
A force acts in the direction (direction of arrow G) in which the flexure of the sheet 1 itself is eliminated. By this force, the paper 1a
The end of the sheet is released from the claw 9 and is ejected from the inside of the paper feed case 2. Then, the paper is fed to the printing unit by the paper feed roller 3.

[0003]

However, in the above configuration, in order to reliably feed the sheets one by one, factors such as the pressure and the positional relationship between the sheet feeding roller and the sheets, and the shape of the claw are required. However, complicated mechanical adjustment was necessary. In addition, if the type and size of the paper are different, there is a problem in that the paper feed roller and the claw must be arranged in completely different positional relationships. Further, when the paper comes out of the paper feed case, it may be scratched on the paper due to the engagement with the claws, and there is a problem that the print quality is damaged.

The present invention has been made in order to solve the above-mentioned conventional drawbacks, and provides a paper feeding mechanism which is not affected by the positional relationship of rollers and the shape of a claw, and has no paper scratches at the time of paper feeding. The purpose is to

[0005]

A paper feeding mechanism of the present invention for solving the above problems is provided with a paper feeding mechanism for picking up a bent paper by another roller by a paper feeding roller and removing it from the tab. And

[0006]

[Function] In the above structure, since the bent sheet is picked up by the auxiliary roller at the time of feeding, the sheet is not damaged. Further, since the paper feed roller performs only the operation of bending the paper, there are few problems in arrangement and the claw shape may be simple. Then, it is possible to stably supply the paper to the printing unit.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view of a sheet feeding mechanism according to an embodiment of the present invention, and FIGS. 2A to 2E are a front view and a side view showing the sheet feeding operation divided in time. In FIG. 1, a sheet 1a is set inside a box-shaped sheet feeding case 2 set in the apparatus. Claws 9 are provided on one entire side of the opening for setting the paper.
On the bottom surface of the paper feed case 2, a hopper spring 4 and a hopper spring 5 are attached.
Is pushing the paper upwards. For this push-up, one end of the hopper 4 (the side opposite to the claw 9) is rotatably attached to the bottom surface of the paper feed case 2, and the other end is pushed up by a hopper spring 5. By doing so, the other end of the sheet 1a is caught by the claw 9.

Similar to the prior art, a paper feed roller 3a having a shaft rotatably attached to a chassis (not shown) is provided above the paper feed case 2, and the roller 3a is used to feed the paper in the paper feed case 2. It is placed at a position where it abuts 1a,
By pushing up the hopper 4, the sheet 1 is pressed against the sheet feeding roller. Therefore, even if the amount of the sheet 1a is small, this pressure contact is performed.

In parallel with the sheet feeding roller 3 and diagonally above it,
A paper feed roller 3b having a shaft rotatably attached to a chassis (not shown) is provided. Pulleys 11 and 11 are respectively provided at positions where the shaft of the roller 3b and the shaft of the roller 3a face each other.
Is attached and is connected by a belt 10 to synchronize the paper feed roller 3a and the paper feed roller 3b.

Auxiliary roller drive shafts 8, 8 which are rotatable in a direction perpendicular to the axial direction of the roller 3b are arranged at both ends of the paper feed roller 3b. This drive shaft 8, 8
Auxiliary rollers 7, 7 having an axis in a direction perpendicular to the surface and rotatable with respect to the axis are arranged on the surface of the roller. The auxiliary rollers 7 and 7 come into contact with the sheet feeding roller 3b when the auxiliary roller drive shafts 8 and 8 rotate inward (in the directions B and B'in the figure) by a control unit (not shown). Rotate with 3b. In the initial state, the auxiliary roller 7 stands by at the position shown in FIG. When the sheet feeding operation is started, the sheet feeding roller 3a is driven in the direction of arrow A, and at the same time, the sheet 1a
As shown in (b), the sheet is bent and deformed between the sheet feeding roller 3a and the tab 9 provided at the end of the sheet feeding direction (direction of arrow F). If the paper feed roller 3a is still driven,
The sheet 1a is further flexurally deformed as shown in FIG. When the maximum deforming portion of the paper 1a reaches the position of the paper feed roller 3b provided on the paper feed case 2, the auxiliary rollers 7 provided at two places as shown in FIG. The auxiliary roller drive shaft 8 is driven in the direction of 'to contact the sheet feeding roller 3b. At this time, the sheet 1a is shown in FIG.
As shown in (e), it is configured to be sandwiched between the paper feed roller 3b and the auxiliary roller 7. When the auxiliary roller 7 is driven and comes into contact with the paper feed roller 3b, the paper 1a is scooped up, and at the same time, the edge of the paper is released from the tab 9. The paper feed roller 3a and the paper feed roller 3b are configured such that the driving force is transmitted by the pulley 11 provided at the end portions and the belt 10 (direction of arrow C).

Then, the sheet 1a is reliably fed to the printing portion (in the direction of arrow E) while being held by the rotational driving of the sheet feed roller 3b and the auxiliary roller 7 (arrows C and D).

[0012]

According to the present invention, the bending of the paper at the time of feeding the paper is used to hold the paper after picking it up by using the auxiliary roller, so that the paper is fed to the printing mechanism without being damaged. Can be transported.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a perspective view of a paper feed mechanism of a printer.

2A and 2B are a front view and a side view showing a paper feeding operation of the paper feeding mechanism unit divided into temporal operations.

FIG. 3 is a perspective view showing a sheet feeding mechanism section of a conventional example according to the present invention.

[Explanation of symbols]

 1a Paper set in the paper feed case 2 Paper feed case 3a Paper feed roller (first paper feed roller) 4 Hopper (pushing means) 5 Hopper spring (pushing means) 3b Paper feed roller (second paper feed roller) 7 Auxiliary roller 8 Auxiliary roller drive shaft 9 Claw 10 Belt 11 Pulley Arrow A Feed roller 3a rotation direction Arrows B, B'Auxiliary roller movement direction Arrow C Feed roller 3b rotation direction Arrow D Auxiliary roller rotation direction Arrow E Paper transport direction Arrow F Paper feed direction

Claims (1)

[Claims] 1. A storage case that stores a sheet of a predetermined shape, and has a push-up unit that pushes up the edge of the sheet from the lower surface, and a tab that holds the edge of the sheet pushed up by the push-up unit, and a storage case that stores the sheet. A first paper feed roller that is located above the case and that pushes out the paper in the claw direction, and a first paper feed roller that is parallel to the first paper feed roller so as to sandwich the paper that is pushed out by the first paper feed roller. It has a second paper feed roller located above the paper, and a rotary shaft located at an end of the second paper feed roller and rotatable to a position parallel to the second paper feed roller. An auxiliary roller, and when the paper is pushed out by the first paper feed roller and conveyed to the vicinity of the second supply roller,
The auxiliary roller is rotationally moved so that the rotation axis of the auxiliary roller is parallel to the second paper feed roller, and the paper is nipped and conveyed by the auxiliary roller and the second paper feed roller. Printer.