JPH03182442A - Automatic sheet feeder - Google Patents

Abstract

PURPOSE:To reduce the occurrence probability of the duplicated feed by providing a flexible friction member put into contact with a transfer member at multiple positions. CONSTITUTION:A friction member 1 is pressed with a force F only at portions finally put into contact with a transfer roller 2, and the friction member 1 is pulled by a friction force F'. The friction member 1 is pressed by the transfer roller 2 with a force F'sin theta near a portion C, where theta is the angle between the face of the portion B and the face of the portion C of the friction member 1. Only the sheet in contact with the transfer roller 2 is separated from multiple stacked sheets 4 at the portion C, if the separation fails, multiple sheets 4 are duplicatively fed, a separating action is performed at the portion B by the same action as at the portion C, and only one sheet is transferred.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic paper feeder used in facsimile machines, copying machines, printers, and the like.

2. Description of the Related Art Conventionally, this type of automatic paper feeder has a structure as shown in FIG.

In FIG. 3, 1a is a friction member, 2 is a conveyance roller for conveying paper, and the friction member 1a is rotatably fixed at point A. It is pressed with force F. 3 is a guide for holding paper, and 4 is a plurality of stacked sheets of paper. Also, the paper 4 is 4-1.4-
2.4-3. 6a is a support member that supports the friction member.

Regarding the automatic paper feeder configured as described above.

The operation will be explained below.

The paper that has reached the conveyance roller 2 attempts to advance in the rotational direction of the conveyance roller due to the frictional force between the paper 4 and the conveyance roller 2. At the same time, the leading edge of the paper 4 comes into contact with the friction member 1a and attempts to stop. At this time, the friction coefficient between the conveyance roller 2 and the paper 4 is μA, and the friction coefficient between the friction member 1a and the paper 4 is μB1 paper 4
If the coefficient of friction between them is μC, then μA〉μB〉μ
It is in the relationship of C. Therefore, although the paper 4-1 in contact with the conveyance roller 2 is in contact with the conveyance roller 2 and the friction member 1a at the same time, the friction between the paper and the conveyance roller 2 is greater than the friction between the paper 4-1 and the friction member 1a. Because it is smaller than the force, it is transported.

Next, the paper 4-2 tries to be conveyed by the frictional force between the paper 4-1 and the paper 4-2, but it is not conveyed because the frictional force between the paper 4-2 and the friction member is large. Stop.

In order to operate as above, the paper 4- closest to the transport roller
Only 1 is transported.

Problems to be Solved by the Invention In such a conventional configuration, since there is only one separation point, paper separation may fail due to the paper installation conditions or the inclination of the friction member, resulting in double feeding. I had an issue. The present invention is intended to solve these problems, and aims to ensure paper separation and prevent double feeding.

Means for Solving the Problem In order to solve this problem, the present invention is configured such that the friction member contacts the conveying member at a plurality of locations.

Effect: With this configuration, even if a plurality of sheets of paper are separated at the first separation point and double-feed is caused, the paper that has been multi-fed can be further separated at the next separation point.

Embodiment FIG. 1 shows the configuration of an automatic paper feeder according to an embodiment of the present invention. Reference numeral 1 denotes a friction member which can be freely bent at one point, 2 a conveyance roller, 3 a guide for holding paper, and 4 a paper. Since these are the same as those in the conventional example, their explanations will be omitted.

Reference numeral 6 denotes a support member for the friction member 1, which is divided into two parts so as not to hinder the bending of the friction member.

The operation of the automatic paper feeder configured as above will be described below.

As shown in Fig. 2, only the portion of the friction member 1 that finally contacts the conveyance roller 2 is pressed by a force F, but due to the frictional force,
The friction member is pulled by a force F'.

As a result, when the angle formed by the surface of the B section and the surface of the 0 section of the friction member is θ, the area around the 0 section is pressed against the conveying roller 2 with a force of F'sin θ. Therefore, in the 0th copy, only the paper in contact with the conveyance roller is separated from the stacked sheets of paper in the same manner as in the conventional example, but if separation fails, multiple sheets of paper overlap as shown in Figure 2. The sheets are then fed, and a separation operation similar to that for the 0th sheet is further carried out at section B, and only one sheet is conveyed.

□D In the present invention, separation is performed at two locations, but it is also possible to further increase the number of separation locations.

Effects of the Invention In the present invention, the friction member is flexible and can contact the conveying member at multiple locations, so that the probability of double feeding can be reduced compared to conventional automatic paper feeding devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an automatic paper feeder according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the automatic paper feeder, and FIG. 3 is a block diagram of a conventional automatic paper feeder. 1... Friction member, 2... Conveyance roller,
3...Guide, 4...Plural stacked sheets of paper, 5...Supporting member.

Claims (1)

[Claims] An automatic sheet feeding device that separates a plurality of stacked sheets of paper one by one using the frictional force of two frictional members, which is equipped with a freely bendable frictional member that contacts a conveying member at a plurality of locations.