JPS63282030A - Sheet feeder - Google Patents

Abstract

PURPOSE:To prevent a paper sheet from slipping on a platen, by providing a paper feed roller having a frictional semi-cylindrical paper feed section and a non-frictional disc-like paper slipping section. CONSTITUTION:When a sheet feeder receives a paper feed-in instruction, a paper sheet roller 6 is rotated in the direction (a), and the uppermost one of paper sheets 1 is fed into between a platen 3 and the contact section of a pressure roller 4 due to the rotary friction of a paper feed section 10. After the paper feed section 10 is rotated by one-half of revolution, the leading end of the paper sheet 1 enters into between the platen 3 and the pressure roller 4, and the sheet 3 is clamped between the platen 3 and the pressure roller 4 so as to be drawn toward the platen 3. At this time, the end part of the paper sheet 1 on the paper feed roller 5 side makes into contact with a frictionless paper slipping section 11 so that the paper sheet 1 is smoothly drawn toward the platen 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sheet feeder that is installed in a printer and feeds paper from a paper cassette to a platen.

[Prior Art] Conventionally, this type of sheet feeder has the following structure, as shown in FIG.
A paper cassette 12 that supports the leading edge of the paper 1 with a claw part 7 and stores the paper 1 placed on an inclined plate 6, and a paper feed roller 13 that feeds the paper 1 in the paper cassette 12 to the platen side. It was configured. The paper feed roller 13 is formed of a cylindrical frictional member, and has its circumferential surface in contact with the surface of the uppermost sheet of paper 1, and uses its rotational friction to feed the uppermost sheet of paper 1 toward the platen. That is, when the paper feed roller 13 is rotated in the direction of the arrow in the figure, the paper feed roller 13
The paper 1 in the top row that comes into contact with the paper 1 bends, climbs over the claw portion 7 of the paper cassette 12, is separated from the other papers 1, and is sent to the platen side.

[Problems to be Solved] In the conventional sheet feeder described above, the paper feed roller 13 formed of a cylindrical friction member is connected to the paper cassette 1.
2 in contact with the paper 1, and the rotational friction causes the paper 1 to
Since the structure is such that paper 1 is fed to the platen side, each sheet of paper 1 is reliably fed to the platen, but when the leading edge of paper 1 enters the contact area between the platen and the pressure roller, the paper 1 is fed to the platen side. Since the paper 1 of the sheet feeder is pulled by the paper feeder, a considerable load is applied, and when used continuously, the friction of the platen decreases due to the influence of paper powder, causing problems such as slipping of the paper 1.

[Means for Solving Problems] The present invention has been made in order to solve the above-mentioned conventional problems, and as a means for solving the problem, paper in a paper cassette is sent to the contact area between the platen and the pressure roller by rotational friction. In the sheet feeder, the paper feed roller is made of a frictional member and has a semi-cylindrical shape having an arc length equal to the distance between the leading edge of the paper in the paper cassette and the contact portion. A paper feeding section and a non-1! which is coaxially arranged with the paper feeding section. The present invention provides a sheet feeder characterized by having an IJ5 disc-shaped paper cassette.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of a sheet feeder according to an embodiment of the present invention, and FIG. 2 is a perspective view of a paper feed roller used in the sheet feeder of FIG.

The sheet feeder includes a paper cassette 2 that stores paper 1, and a paper feed roller 5 that feeds the paper 1 from the paper cassette 2 to a contact portion between a platen 3 and a pressure roller 4.

The paper cassette 2 includes a plate 6 for placing the paper 1, a claw portion 7 that supports the leading edge of the paper 1, and a spring 8 that urges the plate 6 toward the paper feed roller 5 side.

The paper feed roller 5 is arranged at a position where its circumferential surface contacts the uppermost paper 1 in the paper cassette 2, and rotates in the direction of arrow a around a shaft 9 to move the paper between the platen 3 and the pressure roller 4. Feed paper 1 to. As shown in FIG. 2, the paper feed roller 5 is composed of a paper feed section 10 and a paper slide section 11. The paper feeding section 10 is made of a frictional member such as rubber and formed into a semi-cylindrical shape, and is supported by a shaft 9. Paper feed section l
The length of the arc formed by the circumferential surface of O is set equal to the distance between the claw portion 7 of the paper cassette 2 and the contact portion of the platen 3 and pressure roller 4. The paper sliding part 11 is in the shape of a disk having the same diameter as the paper feeding part 10, and is attached to the shaft 9 coaxially with the paper feeding part 10. Further, the paper sliding portion 11 is made of a non-frictional material such as plastic.

Next, the operation of the sheet feeder according to this embodiment will be explained.

When the sheet feeder receives a paper feeding command, the paper feeding roller 5 rotates in the direction of arrow a, and the rotational friction of the paper feeding section 10 feeds the topmost paper 1 to the contact area between the platen 3 and the pressure roller 4.

When the paper feeding section 10 rotates half a rotation, the leading edge of the paper 1 reaches the platen 3.
The paper 1 is sandwiched between the platen 3 and the pressure roller 4 and pulled toward the platen 3. At this time, the end of the paper 1 on the paper feed roller 5 side is in contact only with the frictionless paper slide 11, so the paper 1
is smoothly pulled toward the platen 3 side.

[Effects of the Invention] As described above, the present invention provides a semi-cylindrical paper feeding section in which the paper feeding roller has an arc length equal to the distance between the leading edge of the paper in the paper cassette and the contact portion between the platen and the pressure roller. and a non-frictional disc-shaped paper cassette arranged coaxially with the paper feeding section, the load of pulling out the paper from the paper cassette at times other than paper feeding is reduced, and as a result, the paper on the platen is This has the effect of preventing slips.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a sheet feeder according to an embodiment of the present invention, and FIG. 2 is a perspective view of a paper feed roller used in the sheet feeder of FIG. Moreover, FIG. 3 is a schematic diagram of a conventional sheet feeder. 1: Paper 2: Paper cassette 3 Nibraten 4: Pressure roller 5: Paper feed roller 10: Paper feed section 11: Paper sliding section

Claims (1)

[Claims] A sheet feeder equipped with a paper feed roller that feeds paper in a paper cassette to a contact portion between a platen and a pressure roller by rotational friction, wherein the paper feed roller is a frictional member and a semi-cylindrical paper feeding section having an arc length equal to the distance between the leading edge of the paper inside and the contacting section, and a non-frictional disc-shaped paper sliding section disposed coaxially with the paper feeding section. A sheet feeder comprising: