JPH07112831A - Paper feeder - Google Patents

Abstract

(57) [Summary] [Object] To prevent the paper 15b stacked on the paper feed tray 2 from bending and accidentally coming into contact with the paper feed roller 30 to cause the double feeding phenomenon of paper. [Structure] A sheet feeding tray 2 of a printer device 1 is configured to be attachable and detachable in an obliquely downward direction toward a sheet feeding section 3, and the sheet feeding section 3 has a substantially D-shaped sheet feeding roller in a side view. Three
0 is supported by the rotation drive shaft 32 that rotates intermittently, the paper feed rollers 30 are arranged near the lower part of the front surface side of the laminated paper 15b on the paper feed tray 2, and the paper feed rollers 30 are fed one by one by intermittent rotation. On the other hand, paper is fed to the rotary drive shaft 32 while the paper is being fed.
0 is a paper retainer in which a pressing surface 31a having a vertically elongated shape is formed so as to prevent contact between the flat peripheral surface of the sheet No. 0 and the surface of the stacked paper 15b and to allow pressure contact with the peripheral surface of the paper feed roller 30. The body 31 is rotatably loosely fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a sheet feeding device in an image forming apparatus such as an electrophotographic copying machine, a printer, a facsimile machine or the like.

[0002]

2. Description of the Related Art Generally, a sheet feeding device of this type of image forming apparatus is mounted on a bottom plate of a sheet feeding tray having an open top and a substantially rectangular shape in plan view. In this configuration, a large number of sheets of paper are stored in a stacked state, and this paper feed tray is inserted in a substantially horizontal direction toward the paper feed section at the bottom of the main body of the image forming apparatus. A D-shaped paper feed roller is provided, and at the time of paper feeding, the circumferential surface of the paper feed roller is pressed against the uppermost sheet of the upwardly biased stacked sheets to feed the sheets one by one. When the paper feed is stopped, the flat peripheral surface of the paper feed roller is intermittently rotated so as to face the paper surface in a state of being separated therefrom.

[0003]

However, when the papers stored in the paper feed trays are stacked obliquely downward, the lower end of the paper feed tray portion faces the front side of the stack. Since the paper easily bends so as to be convexly curved, even if the flat peripheral surface of the D-shaped paper feed roller in side view faces the surface of the laminated paper, the flat peripheral surface presses or presses the surface of the paper. Since the sheets come into contact with each other to feed the sheets, a so-called double sheet feeding phenomenon occurs, and there is a problem that the sheets cannot be reliably fed one by one from the lower end of the sheet feeding tray section.

It is an object of the present invention to provide a paper feeding device having a simple structure and eliminating the double paper feeding phenomenon.

[0005]

In order to achieve the above object, a sheet feeding device of the present invention drives a plurality of sheets stacked in a sheet feeding tray to intermittently rotate a sheet feeding roller having a substantially D-shape in a side view. The sheet feeding tray is configured to be detachably mountable obliquely downward toward the sheet feeding unit, and the sheet feeding roller in the sheet feeding unit is mounted on the sheet feeding tray. Of the laminated paper, the rotary drive shaft on which the paper feed roller is mounted prevents contact between the flat peripheral surface of the paper feed roller and the surface of the laminated paper. In addition, a paper pressing body in which upper and lower pressing surfaces are formed so as to allow pressure contact with the circumferential surface of the sheet feeding roller is rotatably loosely mounted.

[0006]

EXAMPLES Next, examples embodying the present invention will be described. FIG. 1 is a perspective view of an ink jet type printer device 1, FIG. 2 is an exploded perspective view of a paper feed tray 2 which also serves as a paper discharge, and FIG. FIG. 4 is a perspective view showing a state of mounting, and FIG. The main body of the printer device 1 includes a lower case 4 accommodating a mechanical section 6 of the printer, a board 7 for electronic control, a drive motor (not shown), and an upper case 5 covering the mechanical section 6 from above. 4 and the upper case 5 are fitted to each other and connected.

On one side surface of the mating portion of the lower case 4 and the upper case 5, as shown in FIG. 4, a manual insertion guide body 1 is formed in an oblong shape having an internal hollow shape by an upper plate 8 and a lower plate 9.
Locking claw 1 that holds 0 sheet insertion section 11 and integrally projects from the sheet pulling section 12 where the upper plate 8 and the lower plate 9 are close to each other
4 is detachably attached to and supported by a metal plate frame 13 of the mechanism section 6.

The sheet 15a inserted into the manual guide body 10 is guided to the upper peripheral surface of the platen 17 through a gap 16 formed in the frame 13 in the lateral direction, and passes between the sheet and the ink jet type printing section 18. Then, the sheet is discharged from the sheet discharge port 19a formed in the top cover 19 detachably mounted on the upper surface of the upper case 5 toward the sheet receiving plate 20 arranged on the front surface side of the sheet feeding tray 2. . The lower case 4, the upper case 5, the manual guide body 10 and the top cover 19 are each made of synthetic resin.

As can be understood from FIGS. 2 to 4, the paper feed tray 2 is urged upward via a coil spring 22 on a portion of the tray main body 21 having an open upper surface and having a rectangular shape in plan view, near the lower portion of the bottom plate 21a. Pins 24 on the upper end side of the supported support plate 23
It is mounted so that it can rotate up and down around. Further, an operating lever 25 extending along the surface of the bottom plate 21a to the outside of the one side plate 21b allows the support plate 23 to be biased by the coil spring 22 and the biasing prohibited state in which the support plate 23 is brought close to the bottom plate 21a. The position can be selectively retained in and. Further, the base portion of a metal support rod 26 having a U-shape in a plan view can be detachably attached to the upper end side of the bottom plate 21a.

Left and right side plates 21b, 21 of the tray body 21
In b, there are provided fitting portions 27 for supporting both left and right ends of the wide board portion of the paper receiving plate 20, and stopper portions 28, 28 for supporting the paper receiving plate 20 so as not to slide down. , Single-cut sheet 1 stacked on the support plate 23
The sheet 5b is fed toward a sheet feeding unit 3 described later through a space between the lower end of the bottom plate 21a and the lower edge of the sheet receiving plate 21.

The sheet feeding roller 30 of the sheet feeding section 3 which is substantially D-shaped when viewed from the side and whose circumferential surface has a large friction coefficient, and the paper pressing member 31 which is made of synthetic resin and has a substantially rectangular shape when viewed from the side are the top cover. The partition plate 1 is provided so as to be adjacent to the sheet discharge port 19a at 19
A plurality of paper feed rollers 3 are attached to a rotary drive shaft 32 provided on the lower surface side of 9b (see FIGS. 3 and 4) and intermittently rotated by a motor (not shown).
0 is fixed so as to rotate integrally, and similarly, the elastic locking claws 31b of the plurality of paper pressing members 31 are engaged with locking grooves 33 formed at appropriate portions of the rotary drive shaft 32 to drive the rotation. It is immovable in the longitudinal direction of the shaft 32, and the rotary drive shaft 3
It is rotatably loosely fitted regardless of the rotation of 2.

The details of the paper pressing body 31 will be further described with reference to FIGS. 5 to 7. The paper pressing body 31 is located above the lower end of the paper feed tray 2 with the axis 32a of the rotary drive shaft 32 interposed therebetween. It is formed so as to be long and the lower end side of the paper pressing body 31 becomes heavy due to the difference in the thickness of the ribs 34 and the like. The pressing surface 31a, which is one of the long sides of the paper pressing body 31, has the paper 15 stacked on the support plate 23.
b, the dimension H1 from the shaft center 32a to the pressing surface 31a is larger than the dimension R1 to the flat peripheral surface 30a of the sheet feeding roller 30, and the circumference of the sheet feeding roller 30 is large. It is set to be smaller than the dimension R2 up to the surface 30b. As a result, the pressing surface 31 a that is vertically long and the longitudinal is the flat peripheral surface 3 of the paper feed roller 30.
0a and the surface of the stacked sheets 15b are prevented from contacting with each other, and pressure contact with the circumferential surface 30b of the sheet feeding roller 30 is allowed.

The paper feed tray 2 is detachably supported by the support portion 35 of the upper case 5, and an operation panel portion 36 is provided on one side of the upper case 5. With this configuration, in the state in which the paper is not fed, the paper feeding roller 30 is stopped so that its flat peripheral surface 30a faces the front surface side of the paper feeding tray 2, and the paper pressing body 3 is stopped.
The first pressing surface 31a is located closer to the surface of the paper feed tray 2 than the flat peripheral surface 30a. Therefore, when the paper feed tray 2 is detached from the paper feed unit 3, the paper presser body 31 loosely fitted to the rotary drive shaft 32 is freely rotated and pressed down so that the lower end side is downward due to the bias of its own weight. The surface 31a is stable in a posture facing the surface of the paper feed tray 2. Next, when the paper feed tray 2 is mounted obliquely downward toward the paper feed unit 3 and the support plate 23 is biased upward by the turning operation of the operation lever 25, the paper sheets stacked on the support plate 23. The uppermost surface of 15b is restricted by the vertically long pressing surfaces 31a of the paper pressing body 31, and the stacked papers 15b are held flat without being deformed to be convexly curved, In addition, the flat peripheral surface 30a of the paper feed roller 30
Contact with is also prevented.

When a paper feed command is issued, the rotary drive shaft 32 rotates once in the clockwise direction in FIG. 4, the paper feed roller 30 rotates, and the circumferential surface 30b of the paper feed roller 31 is pressed by the pressing surface of the paper pressing body 31. When it comes to the side of 31a, the axis 32 of the rotary drive shaft 32
Since the dimension R2 from a to the circumferential surface 30b is larger than the dimension H1 from the pressing surface 31a, the circumferential surface 30b is rotated while being pressed against the surface of the stacked sheets of paper 15b, and thus stacked. Only the uppermost one of the sheets 15b is fed from the lower end side of the sheet feed tray 2 toward the platen 17. Next, when the flat peripheral surface 30a comes to the pressing surface 31a side of the paper pressing body 31, as described above, the rotary drive shaft 3
Since the dimension H1 from the second axis 32a to the pressing surface 31a is larger than the dimension R1 to the flat peripheral surface 30a of the sheet feeding roller 30, the flat peripheral surface 30a does not contact the surface of the stacked paper 15b, and , The paper pressing body 31 is a rotary drive shaft 32
Since it is loosely fitted regardless of the rotation of, the state in which the surface of the paper 15b is pressed by the pressing surface 31a can be maintained,
Do not feed double paper.

In the present invention, the printing unit 18 is not limited to the ink jet type, but may be a dot impact type,
It goes without saying that various types such as a thermal type such as a thermal head can be adopted.

[0016]

As described above, the paper feeding apparatus of the present invention is capable of carrying out the intermittent rotation drive of a plurality of sheets stacked in the paper feeding tray by the intermittent rotation drive of the paper feeding roller which is substantially D-shaped in side view. A sheet feeding device for feeding sheets one by one, wherein the sheet feeding tray is configured so as to be attachable and detachable obliquely downward toward the sheet feeding section,
The paper feed roller in the paper feed unit is arranged at a position closer to the lower surface side of the laminated paper on the paper feed tray, and the rotary drive shaft on which the paper feed roller is mounted has a flat peripheral surface of the paper feed roller. A paper pressing body having upper and lower pressing surfaces formed to prevent contact with the surface of the stacked sheets and to allow pressure contact with the circumferential surface of the sheet feeding roller is rotatably fitted. Since it is installed, when the paper feeding operation is not executed, the surface of the paper stacked in the paper feeding tray is pressed flat by the pressing surface of the paper pressing body and the flat peripheral surface of the paper feeding roller Paper does not come into contact with the surface, and only the circumferential surface of the paper feed roller can be pressed against the surface of the paper during the paper feeding operation, so the paper is double-fed when the paper feed roller rotates intermittently. Has the effect of reliably preventing

When attaching and detaching the paper feed tray,
Since the paper pressing body can freely rotate around the rotation axis, there is an effect that it does not interfere with the attachment / detachment work. As described above, according to the present invention, since the paper pressing body formed in the predetermined shape is only loosely fitted to the rotary drive shaft, the configuration is extremely simple, and the cost can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of a printer device.

FIG. 2 is an exploded perspective view of a paper feed tray.

FIG. 3 is a perspective view showing a state in which the paper feed tray is attached to the paper feed unit on the upper surface of the main body of the printer device with the top cover removed.

FIG. 4 is a side sectional view of a main part.

FIG. 5 is a sectional view of a paper pressing body.

FIG. 6 is a side view of a paper pressing body.

FIG. 7 is a sectional view taken along the line VII-VII of FIG.

[Explanation of symbols]

 1 Printer Device 2 Paper Feed Tray 3 Paper Feeding Part 17 Platen 18 Printing Part 20 Paper Receiving Plate 21 Tray Body 22 Coil Spring 23 Supporting Plate 30 Paper Feeding Roller 31 Paper Pressing Body 31a Holding Surface 31b Locking Claw 32 Rotation Drive Shaft 33 Engagement Gutter

Claims (1)

[Claims] 1. A sheet feeding device that feeds a plurality of sheets stacked in a sheet feeding tray one by one by intermittent rotation driving of a sheet feeding roller having a substantially D-shape in side view. The sheet feeding roller in the sheet feeding section is arranged at a position closer to the lower surface side of the stacked sheets on the sheet feeding tray, while the sheet feeding roller is The mounted rotary drive shaft is vertically moved to prevent contact between the flat peripheral surface of the sheet feeding roller and the surface of the stacked sheets and to allow pressure contact with the circumferential surface of the sheet feeding roller. A paper feeding device, in which a paper pressing body having a longitudinal pressing surface is loosely rotatably mounted.