JPH10279118A - Paper sending mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly detach or press two rollers from/against the surface of recording paper. SOLUTION: A projected part 13 is prepared in the middle part of a supporting frame 10, which supports two pinch rollers 11, 11. By applying the energizing force of a spring 14 to the projected part 13, the recording paper can be pressed uniformly against the surface of a sub-paper-sending roller 1 via two rollers 11, 11. In addition, by bringing a flat surface 18a of a pushing/ pressing lever 18, which is provided on a lever 16, to a flat edge 15a of a window hole 15, which is provided in the supporting frame 10, the two rollers 11, 11 can be detached uniformly from the sub-paper-sending roller 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed mechanism used for a printer or the like.

[0002]

2. Description of the Related Art In order to cope with short paper, it is necessary to arrange more rollers at intervals in a paper transport path. The mechanism for separating these rollers from the pair of paper transport paths becomes complicated, which not only unnecessarily increases the manufacturing cost but also degrades the reliability of the apparatus.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new paper feed mechanism that can easily separate and contact a plurality of rollers arranged at a reduced distance from a paper transport path.

[0004]

That is, according to the present invention, as a paper feeding mechanism for achieving the above object, two rollers are supported by a common supporting member, and a space between both roller supporting portions of the supporting member is provided. The urging member acts on the pressed portion, and a pressed portion is provided in a direction substantially parallel to the sheet conveying direction. The pressed portion operates in conjunction with the sheet feeding and partially presses the flat portion. These rollers are separated and approached in parallel to the conveyance path by moving the pressing members that are formed into contact with each other.

[0005]

Embodiments of the present invention will be described below. The drawings show an embodiment of the present invention applied to an ink jet printer.

In FIG. 1, reference numeral 1 denotes a sub-paper which is inverted by a recording paper pulled out from a hopper 3 by a pickup roller 4 and fed to a main paper feed roller 6 and a paper pressing roller 30 provided in a recording / writing unit 5. On the peripheral surface of the roller 1, a support frame 10 that supports two pinch rollers 11, 11 is disposed on the lower side of the separation pad 7 in the paper transport direction.

The support frame 10 includes two pinch rollers 1
1 and 11 are equally spaced and approached to the peripheral surface of the sub-paper feed roller 1. As shown in an enlarged manner in FIG. By engaging the provided vertical guide groove 12 with the dowel 21 protruding from the inner surface of the side wall of the unit body 20, the vertical guide groove 12 can be separated and approached toward the sub-paper feed roller 1 and can swing about the dowel 21 as a fulcrum. The recording medium on the sub-paper feed roller 1 is applied by applying an urging force of a spring 14 to the sub-paper feed roller 1 on a convex portion 13 provided at the opposite center of the sub-paper feed roller 1. The two pinch rollers 11, 11 supported on the paper can be pressed equally.

On the other hand, reference numeral 16 in the drawing denotes a state in which the pinch rollers 11 are moved around the sub paper feed roller 1 when the leading end of the recording paper is fed into the nip portion B of the main paper feed roller 6 and the paper pressing roller 30. The tip 17 of the lever 16 is in sliding contact with the peripheral surface of the cam 8 which is driven by a paper feed motor (not shown) and rotates, and has a D-shaped cross section. A common operating rod 18 formed in a shape is fixed with its flat surface 18a facing downward, and the operating rod 18 is passed through a window hole 15 provided in the center of the side surface of the support frame 10. Top, its flat surface 1
By pressing the lower side 15a of the window hole 15 with 8a, the two pinch rollers 11, 11 are supported via the support frame 10.
Are separated from the peripheral surface of the sub-paper feed roller 1 by a distance of about 1 mm, that is, a distance corresponding to the thickness of the paper guide rib 22 provided on the unit body 20.

Reference numeral 23 in the drawing denotes an arc-shaped hole provided on the side wall of the unit main body 20 for swinging the operating rod 18, and reference numeral 25 denotes a sensor for detecting recording paper. Is shown.

In the apparatus configured as described above, in a standby state in which the recording paper is not fed, the supporting frame 10 receiving the urging force of the spring 14 at the convex portion 13 at the center of the side surface is shown in FIG. As described above, the two pinch rollers 11, 11 supported
Are equally brought into contact with the peripheral surface of the sub-paper feed roller 1.

In this state, when the recording paper in the hopper 3 is pulled out by the pickup roller 4 and its leading end contacts the nip portion A of the pinch roller 11 and is skewed, as shown in FIG. Then, the cam 8 which is driven by the paper feed motor and rotates, operates the lever 16 in the counterclockwise direction in the drawing against the urging force of the spring 14 by the protrusion 8a,
Flat surface 18a of common shaft 18 fixed to the tip of lever 16
Is pressed against the lower side of the window hole 15 to displace the support frame 10 in parallel, and the two pinch rollers 11, 1
1 is equally spaced from the peripheral surface of the sub-paper feed roller 1 by a distance corresponding to the thickness of the guide rib 22, so that the recording paper can pass through.

When the lever 16 is released by the concave portion 8b of the cam 8 which has been rotated with the passage of the leading edge of the recording paper, the support frame 10 is again provided with the convex portion 1 at the center of the side surface.
3, the support frame 10 swings around the dowel 21 of the unit 20 and pivots the two pinch rollers 11, 11 so as to follow fine irregularities. To make accurate paper feed.

Although the present invention has been described with reference to an apparatus applied to a printer, the present invention can also be applied to other apparatuses which handle sheets such as a copying machine.

[0014]

As described above, according to the present invention, the two rollers are supported by the common support member, and the sheet is fed to the flat pressed surface provided between the support portions of the two rollers. Because a pressing member provided with a flat pressing surface that works in conjunction with is made to come and go, even if a plurality of rollers are arranged close to each other so as to correspond to a short sheet, simply using a complicated mechanism etc., By interposing a common support member, these rollers can be equally spaced and approached from the sheet conveyance path.

In addition, since the urging force of the urging member is applied between the two roller supporting portions of the supporting member, the sheet can be conveyed correctly while the two rollers faithfully follow fine irregularities. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus according to an embodiment of the present invention, showing a state in which a roller is pressed.

FIG. 2 is a configuration diagram of the same device as shown in a state where rollers are separated.

FIG. 3 is an enlarged view of a main part.

[Explanation of symbols]

 Reference Signs List 1 Sub paper feed roller 8 Cam 10 Support frame 11 Pinch roller 13 Convex part 14 Spring 15a Flat surface 16 Operation lever 18 Pressing rod

Claims (2)

[Claims] The two rollers are supported by a common support member, and between the two roller support portions of the support member.
A pressed member that is provided in a direction substantially parallel to the sheet conveying direction is provided, and a pressed member that operates in conjunction with the feeding of the sheet and has a partly flat pressing surface is provided on the pressed portion. A paper feeding mechanism, wherein the two rollers are separated and approached in parallel to the transport path by being brought into contact with and separated from the paper path. 2. An operation portion of an urging member is provided between both roller support portions of the support member, and the both rollers are pressed against a sheet conveyance path by the urging member acting on the operation portion. 2. The paper feed mechanism according to claim 1, wherein: