JP4332481B2 - Paper feeder - Google Patents

Description

  The present invention relates to a sheet feeding device that separates and feeds recording sheets stacked and accommodated in a sheet feeding unit one by one.

  Conventionally, in image forming apparatuses such as printers, copiers, and facsimile machines, and output devices such as computers and word processors, sheet feeding apparatuses have been used to automatically and continuously feed recording sheets one by one.

  Recording paper used in image forming devices and output devices (hereinafter collectively referred to as “main device”) includes plain paper, high-quality paper, thermal paper, cardboard, overhead projector (OHP) paper, tracing paper, art Paper, coated paper, etc. are used.

  FIG. 4 is a schematic cross-sectional view of the main body apparatus 101 in the vicinity of the paper feed unit 102. The main body apparatus 101 includes a paper feeding unit 102 and a recording unit (not shown). The paper feeding unit 102 stacks and stores recording paper 103, and one sheet of recording paper 103 is fed from the paper feeding unit 102 to the recording unit. Each sheet is fed one by one.

  The paper feeding unit 102 includes a stacking unit 104 that stacks the recording paper 103 and a paper feeding unit 105 that feeds the recording paper 103. As the stacking means 104, a paper feed tray or a paper feed cassette is used, and a paper guide 106 for positioning the recording paper is provided. As shown in FIG. 4, the sheet feeding means 105 presses the sheet feeding roller against the recording sheet 103 and rotates the sheet feeding roller in the direction of the arrow to feed the recording sheet 103 in contact with the sheet feeding roller. It is conveyed toward the inside of the main unit through the mouth 110.

  The recording sheet 103 is transported from the paper feed port 110 to the recording unit by a transport mechanism (not shown), and recording is performed by various methods such as impact type, thermal type, thermal transfer type, ink jet type, electrophotographic type, and sublimation type. Information is recorded on the sheet 103.

  In the conventional paper feeding device, in order to feed the recording paper one by one to the recording unit, a plane 111 (indicated by a dotted line in FIG. 4) perpendicular to the paper feeding direction of the recording paper is provided in the paper feeding port 110 of the paper feeding unit 102. A slope 112 inclined by an angle φ is provided. As a result, the recording paper 103 conveyed by the paper feeding means 105 hits the slope 112, but since the slope 112 is inclined by an angle φ from the vertical, only one sheet is separated along the slope 112 and fed. It is conveyed from the mouth 110 toward the recording unit. Conventionally, the angle φ of the slope 112 was 20 ° to 30 °.

JP-A-9-2671 JP-A-9-240868 JP-A-9-315606 No. 7-45482 Japanese Utility Model Publication No. 6-25242

  However, in the conventional paper feeding device, the angle φ is as small as 20 ° to 30 °. Therefore, when the leading end of the recording paper 103 in the paper feeding direction is warped downward, the recording paper conveyed by the paper feeding means 105. Since 103 hits at an angle close to perpendicular to the inclined surface 112 of the paper feed port 110, an error of non-feed in which the recording paper 103 was not supplied occurred.

  Further, when the angle φ is simply increased, double feed (double feed) occurs although no feed occurs.

  SUMMARY An advantage of some aspects of the invention is that it provides a highly reliable paper feeding apparatus capable of feeding recording sheets one by one.

In order to achieve the above object, a paper feeding device according to the present invention records from the paper feeding unit of the device having a paper feeding unit in which recording papers are stacked and stored and a recording unit for recording information on the recording paper to the recording unit. A sheet feeding device that feeds sheets one by one to a sheet feeding port of the sheet feeding unit that feeds the recording sheet from the sheet feeding unit to the recording unit. An inclined surface and a second inclined surface are provided, the surface of the first inclined surface is mirror-finished, the surface of the second inclined surface is textured, and the first inclined surface and the recording paper feeding direction are orthogonal to each other. An angle formed with a flat surface is larger than an angle formed between the second inclined surface and the flat surface, and the second inclined surface has a larger coefficient of friction with respect to the recording paper than the first inclined surface. .

According to another aspect of the present invention, there is provided a sheet feeding device that includes a sheet feeding unit in which recording sheets are stacked and a recording unit that records information on the recording sheet. a sheet feeding apparatus for feeding one by one, the sheet feeding port of the paper feed unit for feeding the recording sheet to the recording unit from the paper feeding portion, a concave curved surface is provided, the sheet of the curved surface The surface near the paper portion side is mirror-finished, the surface near the recording portion side of the curved surface is textured, and an angle formed by a tangent of the curved surface and a plane orthogonal to the paper feeding direction of the recording paper is The friction coefficient with respect to the recording paper is larger in the vicinity of the recording portion side than in the vicinity of the paper feeding portion side of the curved surface.

  In the paper feeding device of the present invention, the first inclined surface of the paper feeding port where the recording paper first strikes is inclined at a large angle, so even if the recording paper has a tip warped downward, Therefore, the recording paper can be conveyed toward the paper feed port, and non-feeding can be prevented.

  Furthermore, since the recording sheet conveyed toward the paper feed port has the second inclined surface inclined at a small angle and the friction coefficient with respect to the recording sheet is large, it is surely separated into one sheet by friction with the second inclined surface. Thus, the occurrence of double feeding can be suppressed and the sheets can be fed one by one.

  In particular, since the surface of the first slope is mirror-finished, slipping is improved, so that the recording paper whose tip is warped downward can be more reliably conveyed toward the paper feed port. By subjecting the surface to a rough surface, it is possible to easily roughen the surface roughness of the second slope and increase the friction coefficient.

  In another sheet feeding device of the present invention, a curved surface is provided at the sheet feeding opening, in which an angle formed between a tangent line and a plane perpendicular to the sheet feeding direction of the recording sheet becomes smaller in order from the sheet feeding unit side. Since the curved surface of the paper feed slot where the recording paper first strikes is inclined at a large angle, even if the recording paper has a tip that warps downward, it strikes diagonally against the curved surface. It can be conveyed toward the paper feed port, and the occurrence of non-feed can be prevented.

  Further, the recording paper conveyed toward the paper feed opening is inclined at a small angle near the recording portion side of the curved surface and has a large friction coefficient with respect to the recording paper, so that it is surely separated into one sheet by friction with that portion. Thus, the occurrence of double feeding can be suppressed and the sheets can be fed one by one.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of the main body device 1 in the vicinity of the paper feed unit 2, and FIG. 2 is an enlarged view of a main part of FIG. 1.

  The main body device 1 has a paper feed unit 2 and a recording unit (not shown). A recording paper 3 is stacked and accommodated in the paper feed unit 2 and passes from the paper feed unit 2 to the recording unit through a paper feed port 10. The recording paper 3 is fed one by one.

  The paper feeding unit 2 is provided with a stacking unit 4 for stacking a plurality of recording papers 3 and a paper feeding unit 5 for feeding the recording papers 3.

  The recording paper 3 is not particularly limited, and plain paper, high-quality paper, thermal paper, cardboard, OHP (overhead projector) paper, tracing paper, art paper, coated paper, and the like can be used.

  As the stacking means 4, a paper feed tray, a paper feed cassette, or the like can be used, and a paper guide for positioning the recording paper to the side and rear of the recording paper (in FIG. 1, only the rear paper guide 6 is shown. ) May be provided. Further, although not shown in FIG. 1, the stacking unit 4 may include a unit that urges the recording sheet 3 toward the sheet feeding unit 5.

  Further, the stacking means 4 may be arranged horizontally as shown in FIG. 1, but is inclined downward toward the paper feed port 10 to facilitate the positioning of the recording paper 3 and to reduce the size of the main body apparatus 1. You can also.

  As the paper feeding means 5, a paper feeding roller can be used. By rotating the paper feeding roller in pressure contact with the recording paper 3, the recording paper 3 in contact with the paper feeding roller is brought into the paper feeding opening 10. It can be transported towards. In order to press-contact the sheet feeding roller and the recording sheet 3, the above-described means for biasing the recording sheet 3 may be used, or the sheet feeding roller may be biased to the recording sheet 3.

  In the paper feeding device of the present invention, as shown in FIG. 2, the paper feeding port 10 is provided with a first slope 12a and a second slope 12b from the paper feeding unit 2 side, and the first slope 12a. Is inclined at an angle θ1 with respect to a plane 11 (indicated by a dotted line in FIG. 2) orthogonal to the recording paper feeding direction, and the second inclined surface 12b is inclined at an angle θ2 with respect to the plane 11; The angle θ1 is designed to be larger than the angle θ2.

  The first inclined surface 12a is set to have a larger angle θ1 with the flat surface 11 than the conventional inclined surface. The angle θ1 of the first slope 12a is preferably 30 ° to 40 °.

  As described above, in the paper feeding device 1 according to the present invention, since the first inclined surface 12a of the paper feeding port 10 on which the recording paper 3 first strikes is inclined at an angle θ1 larger than the conventional one, the leading end warps downward. Even the recording paper 3 strikes obliquely against the first inclined surface 12a, so that the recording paper 3 can be separated and the occurrence of non-feed can be prevented. In particular, it is preferable that the surface of the first inclined surface is mirror-finished because slipping is improved, so that the recording paper 3 whose tip is warped downward can be more reliably conveyed toward the paper feed port 10.

  The second inclined surface 12b is provided continuously with the first inclined surface 12a, and is set to an angle θ2 of the same level as the conventional inclined surface. The angle θ2 of the second slope 12b is preferably 20 ° to 30 °. Further, the second inclined surface is conveyed toward the paper feeding port 10 by increasing the friction coefficient with respect to the recording paper and increasing the friction of the recording paper 3 on the second inclined surface than the first inclined surface. Since the recording paper 3 is reliably separated into one sheet by friction with the second inclined surface 12b having a small angle, it is possible to suppress the occurrence of double feeding and feed the recording paper one by one.

  In order to increase the friction coefficient of the second inclined surface 12b, the surface of the second inclined surface 12b may be subjected to wrinkle processing to give fine irregularities or wrinkles, or the surface of the second inclined surface 12b has a large friction coefficient. It is also possible to increase the friction coefficient by disposing a material such as rubber. Generally, since the first and second slopes are formed by resin molding, the surface of the second slope can be easily textured by using a molding die having a desired shape. Therefore, it is preferable.

  The first inclined surface 12 a and the second inclined surface 12 b may be formed integrally with the stacking unit 4 or may be formed by forming a sheet feeding port of the main body device 1 that holds the stacking unit 4. A plurality of slopes may be further provided between the first slope 12a and the second slope 12b. The plurality of inclined surfaces are inclined with respect to the plane 11 at an angle smaller than the angle θ1 and larger than the angle θ2, and are arranged so that the angles are gradually decreased from the first inclined surface 12a side toward the second inclined surface 12b side.

  FIG. 3 shows a modification of the present invention. In FIG. 3, the paper feed port 10 is provided with a concave curved surface 12c, and tangents 13a and 13b of the curved surface 12c (in FIG. 3, the tangent line 13a at the end on the paper feed unit side and the tangent line 13b at the end on the recording unit side) Are shown in FIG. 3 and the planes 11 (indicated by dotted lines in FIG. 3) perpendicular to the sheet feeding direction of recording paper, the angles θ3 and θ4 are gradually reduced from the sheet feeding unit side. Here, the angle θ3 formed by the tangent line 13a at the end of the curved surface 12c on the paper feed unit 2 side and the plane 11 is preferably 30 ° to 40 °, and the tangent line 13b and the plane 11 at the end on the recording unit side are preferably set. Is preferably 20 ° to 30 °.

  Even in the case of the recording paper 3 whose front end in the paper feeding direction is warped downward, the angle θ3 at the end on the paper feeding unit 2 side is larger than the conventional inclination angle, so that it strikes obliquely against the curved surface 12c. Therefore, the recording paper 3 can be separated, and the occurrence of non-feed can be prevented. In particular, if the surface of the curved surface 12c in the vicinity of the paper feeding unit is mirror-finished, slipping is improved, so that the recording paper 3 whose tip is warped downward can be more reliably conveyed toward the paper feeding port 10. preferable.

  Furthermore, since the vicinity of the curved surface 12c near the recording portion is inclined at a small angle and the coefficient of friction with respect to the recording paper 3 is large, the recording paper 3 conveyed toward the paper feed port 10 is in contact with the curved surface 12c near the recording portion. By reliably separating the sheets into one by friction, the occurrence of double feeding can be suppressed and the sheets can be fed one by one. The recording paper 3 can be conveyed toward the paper feed opening at an optimum angle for insertion into the paper feed opening 10 by changing the angle continuously along the curved surface 12c.

  In order to increase the friction coefficient in the vicinity of the recording portion side of the curved surface 12c, the surface of the curved surface 12c in the vicinity of the recording portion side may be subjected to wrinkle processing to give fine irregularities or wrinkles, or a material having a large friction coefficient on the surface. For example, it is possible to increase the friction coefficient by arranging rubber or the like. In general, since the curved surface 12c is formed by resin molding, it is preferable to use a molding die having a desired shape because it can be easily textured.

  Further, the shape of the sheet feeding port 10 may be configured by combining a slope and a curved surface.

  As described above, the recording sheet 3 separated by the sheet feeding device and conveyed to the sheet feeding port 10 is composed of a conveying roller at the end of the sheet feeding port 10 from the sheet feeding port 10 to the recording unit. It is transported by a transport mechanism (not shown). Information is recorded on the recording sheet 3 in the recording unit by various methods such as impact type, thermal type, thermal transfer type, ink jet type, electrophotographic type, and sublimation type.

  In addition, this invention is not limited to the said embodiment, A various change can be made as needed.

Schematic sectional view of the vicinity of a sheet feeding unit in an embodiment of a main body apparatus to which the sheet feeding apparatus of the present invention is applied. The figure which expanded the principal part of FIG. Schematic sectional view showing a modification of the present invention Schematic cross-sectional view of the vicinity of the paper feed unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body apparatus 2 Paper feed part 3 Recording paper 10 Paper feed port
11 Plane 12a First slope 12b Second slope

Claims (2)

A sheet feeding device that feeds recording sheets one by one from the sheet feeding unit of the main body apparatus having a sheet feeding unit in which recording sheets are stacked and stored and a recording unit that records information on the recording sheet. And
Feeding port of the paper feed unit for feeding the recording sheet to the recording unit from the paper feed portion, the first slope and the second slope is provided from the paper feeding portion, the first slope The surface of the second inclined surface is mirror-finished, the surface of the second inclined surface is textured, and an angle formed by the first inclined surface and a plane orthogonal to the recording paper feeding direction is the second inclined surface and the flat surface. A paper feeding device characterized in that the second slope has a larger coefficient of friction against the recording paper than the first slope. A sheet feeding device that feeds recording sheets one by one from the sheet feeding unit of the main body apparatus having a sheet feeding unit in which recording sheets are stacked and stored and a recording unit that records information on the recording sheet. And
A concave curved surface is provided in a paper feeding port of the paper feeding unit that feeds the recording paper from the paper feeding unit to the recording unit, and a surface near the paper feeding unit side of the curved surface is mirror-finished. The surface in the vicinity of the recording unit side is textured, and the angle formed between the tangent of the curved surface and a plane orthogonal to the recording paper feeding direction decreases in order from the paper feeding unit side. A paper feeding device characterized in that a coefficient of friction with respect to the recording paper is larger in the vicinity of the recording section than in the vicinity of the recording section.