JP2009126614A - Paper feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding device capable of performing a stable operation. <P>SOLUTION: A separation plate gear part 7b is fixed to a separation plate movable part 7a, and the separation plate movable part 7a can be turned around the shaft of the separation plate gear part 7b. A transmission gear 10 is connected to the separation plate gear part 7b, and a transmission gear 9 is connected to the transmission gear 10. Furthermore, the transmission gear 9 is connected to a pick lever rotary support shaft gear 8 fastened to the pick lever rotary support shaft 6. The separation plate movable part 7a can be turned so as to be inclined at a changing angle in association with the pick lever 5 with respect to the surface of a paper 1 stacked and held at the uppermost part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet feeding device that automatically conveys paper to a main body (image forming unit) in an image forming apparatus such as a thermal transfer printer or a copying machine, and more particularly to a technique for performing a stable operation.

  A conventional paper feeding device is disposed at the bottom of the paper cassette for stacking and storing paper for recording images, and is mounted on the paper cassette. A lift plate that can be held in an inclined state with respect to the bottom of the paper cassette, a paper feed roller that can be brought into contact with and separated from the surface of the uppermost stacked paper, and a lower portion of the lift plate A pick lever that is disposed on the lift plate so as to come into contact with and separate from the paper feed roller with the surface of the uppermost paper that is stacked and held by abutting and swinging against the lift plate; A separation plate that is pivotally supported under a lift plate, and a pick lever rotation support shaft on which the pick lever is fixed, and a leading edge of the paper come into contact with each other to separate the paper one by one. Are arranged.

  In the paper feeding apparatus configured as described above, in the process of feeding the paper to a thermal transfer system main body (image forming unit), the pick lever is moved around the pick lever rotation support shaft. The paper rotates in a direction inclined with respect to the bottom until the paper comes into contact with the paper feed roller. The paper in contact with the paper feed roller is conveyed to the separation plate by frictional force and separated one by one by the inclination of the separation plate. The separated paper is transported to the transport roller and pressure roller on the main body (image forming unit) side, and the paper feeding operation is completed.

  The angle at which the tilted paper enters the separation plate, that is, the entrance angle θ, changes until it contacts the paper feed roller, depending on the number of papers stacked.

  In the paper, if the entry angle θ to the separation plate becomes too large, the reaction force increases when the separation plate comes into contact, so that non-feeding to the main body (image forming unit) is likely to occur, and the entry angle θ to the separation plate is If it becomes too small, the reaction force becomes small when the separation plate comes into contact, and there is a problem that double feed that transports the second and subsequent sheets occurs.

  In order to stabilize the paper feeding performance, a paper feeding device (see, for example, Patent Document 1) that switches the inclination angle of the separation plate using a cam has been proposed.

Japanese Patent No. 3530719 (8th paragraph, FIG. 1)

  In the paper feeder disclosed in Patent Document 1, the inclination angle of the separation plate is set according to the type of paper (for example, the cut paper is thin and the postcard is thick). However, the paper entrance angle θ may vary depending on factors other than the type of paper, such as the amount of paper loaded. In such a case, a stable operation may not always be performed. There was a problem that it was not possible.

  SUMMARY An advantage of some aspects of the invention is to provide a sheet feeding device capable of performing stable operation.

  A paper feeding device according to the present invention is provided at a bottom portion of a paper cassette for laminating and storing papers for recording images, and is mounted on the paper cassette. A lift plate that can be held in an inclined state with respect to the bottom of the paper cassette, a sheet feeding roller that can be brought into contact with and separated from the surface of the uppermost stacked paper, and the lift plate A pick lever that is disposed in a lower portion of the paper and that allows the surface of the uppermost paper, which is stacked and held by abutting and swinging on the lift plate, to contact and separate from the paper feed roller; The pick lever is pivotally supported under the lift plate and fixed to the pick lever rotating support shaft on which the pick lever is fixed, and the uppermost surface of the laminated and held paper. Inclined at an interlockingly changing angle, and the leading edge of the paper comes into contact and is separated. Characterized in that it comprises a release plate.

  In the paper feeding device according to the present invention, the separating plate is inclined with respect to the surface of the uppermost paper that is stacked and held at an angle that changes in conjunction with the pick lever, so that stable operation is performed. Can do.

  Hereinafter, a thermal transfer type image forming apparatus will be described as an example, focusing on a paper running system, particularly a paper feeding apparatus that conveys the paper to the main body (image forming unit). A detailed description of the configuration of the entire image forming apparatus is omitted.

<Basic technology>
FIG. 1 is a diagram illustrating a configuration of a sheet feeding device 100 according to the basic technology.

  The paper feeding device 100 is disposed at the bottom of the paper cassette 2 for laminating and storing the paper 1 for recording images, and the paper 1 is mounted on the paper cassette 2. A lift plate 3 that can hold the paper 1 in an inclined state with respect to the bottom of the paper cassette 2, and a paper feed roller that can be brought into contact with and separated from the surface of the uppermost paper 1 that is stacked and held. 4 and the surface of the uppermost paper 1 disposed on the lower side of the lift plate 3 and held in contact with the lift plate 3 so as to swing. A pick lever 5 that can be brought into contact with and separated from, a pick lever rotating support shaft 6 that is rotatably supported under the lift plate 3 and is fixed to the pick lever 5, and a tip of the paper 1 A separation plate 7 for separating the paper 1 one by one is provided by contacting the edges.

  In the paper feeding device 100 configured as described above, in the process of feeding the paper 1 to the thermal transfer system main body (image forming unit), the pick lever 5 is centered on the pick lever rotation support shaft 6. The paper 1 rotates in a direction inclined with respect to the bottom of the paper cassette 2 until the paper 1 comes into contact with the paper feed roller 4. The paper 1 in contact with the paper feed roller 4 is conveyed to the separation plate 7 by frictional force and separated one by one by the inclination of the separation plate 7. The separated paper 1 is conveyed to the conveying roller 11 and the pressure roller 12 on the main body (image forming unit) side, and the paper feeding operation is completed.

  Although illustration and detailed description are omitted, a thermal transfer system main body (image forming unit) disposed on the right side of the conveying roller 11 and the pressure roller 12 may be, for example, a platen on a frame constituting the image forming unit. A roller is rotatably supported, and a thermal head is disposed at a position facing the platen roller so as to be able to come into contact with and separate from the platen roller, and an ink cassette around which an ink sheet is wound can be attached to and detached from the frame. The ink sheet is mounted so that the ink sheet is fed out between the platen roller and the thermal head. The paper to be printed travels between the ink sheet and the platen roller. That is, the ink sheet and the paper are sandwiched between the thermal head and the platen roller, and the ink is transferred from the ink sheet to the paper by appropriately giving a signal to the thermal head. ing.

  The angle at which the inclined paper 1 enters the separating plate 7 until it abuts against the paper feed roller 4, that is, the entry angle θ varies depending on the number of sheets of paper 1 stacked. FIG. 2 is a conceptual diagram when the load is relatively large and the approach angle θ is small, and FIG. 3 is a conceptual diagram when the load is relatively small and the approach angle θ is large.

  In the paper 1, if the approach angle θ to the separation plate 7 becomes too large, the reaction force increases when the separation plate 7 comes into contact, so that non-feeding to the main body (image forming unit) is likely to occur. If the approach angle θ is too small, the reaction force is small when the separation plate 7 is in contact, and there is a problem in that double feeding that transports the second and subsequent sheets occurs.

<Embodiment 1>
FIG. 4 is a diagram illustrating a configuration of the sheet feeding device 100a according to the first embodiment. FIG. 4 shows a configuration in which the paper 1 is separated using a separation plate movable portion 7a instead of the fixed separation plate 7 in FIG. The separation plate movable portion 7a is rotatable so as to be inclined at an angle that changes in conjunction with the pick lever 5 with respect to the surface of the uppermost paper 1 that is laminated and held.

  A separation plate gear portion 7b is fixed to the separation plate movable portion 7a, and the separation plate movable portion 7a is rotatable about the axis of the separation plate gear portion 7b. A transmission gear 10 is coupled to the separation plate gear portion 7b, and a transmission gear 9 is coupled to the transmission gear 10. Further, the transmission gear 9 is connected to a pick lever rotation support shaft gear 8 fastened to the pick lever rotation support shaft 6.

  With such a configuration, when the pick lever 5 rotates about the pick lever rotation support shaft 6, power is transmitted from the pick lever rotation support shaft gear 8 to the transmission gear 9, the transmission gear 10, and the separation plate gear portion 7b. Then, the separating plate movable portion 7a is inclined in synchronization with the pick lever 5 according to a predetermined reduction ratio set in advance.

  As described above, according to the paper feeding device according to the present embodiment, a gear is provided on the pick lever rotating support shaft and the separation plate is moved by the transmission gear according to the paper stacking amount. It is possible to provide a paper feeding device that obtains stable paper feeding performance. Further, since it is interlocked with the rotation of the pick lever, it can be manufactured at a lower cost.

It is a figure which shows the structure of the paper feeder which concerns on basic technology. FIG. 5 is a conceptual diagram illustrating a case where the sheet feeding apparatus according to the basic technology has a relatively large load and a small approach angle θ. FIG. 6 is a conceptual diagram showing a case where the paper feeding device according to the basic technology has a relatively small load and a large approach angle θ. 1 is a diagram illustrating a configuration of a sheet feeding device according to a first embodiment.

Explanation of symbols

  1 paper, 2 paper cassette, 3 lift plate, 4 paper feed roller, 5 pick lever, 6 pick lever rotation support shaft, 7a separation plate movable section, 7b separation plate gear section, 8 pick lever rotation support shaft Gear, 9, 10 Transmission gear, 11 Conveying roller, 12 Pressure roller, 100, 100a Paper feeding device.

Claims (2)

A paper cassette for stacking and storing paper for recording images;
A lift plate disposed at the bottom of the paper cassette, mounted with the paper, and capable of holding the paper in an inclined state with respect to the bottom of the paper cassette;
A paper feed roller that can be brought into contact with and separated from the surface of the uppermost paper that is stacked and held;
The surface of the uppermost paper, which is disposed below the lift plate and is rocked in contact with the lift plate, can be brought into contact with and separated from the paper feed roller. A pick lever;
A pick lever rotating support shaft supported rotatably under the lift plate and having the pick lever pivoted;
A separation plate that is inclined at an angle that changes in conjunction with the pick lever and is separated by contact with the leading edge of the paper, with respect to the surface of the uppermost paper that is laminated and held. A paper feeder characterized by that. The sheet feeding device according to claim 1,
The paper feeding device further comprising a transmission gear disposed between the separation plate and the pick lever rotation support shaft.

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