JP2563146Y2 - Paper feeder - Google Patents

Description

[Detailed description of the invention] Object of the invention (industrial application field) The present invention relates to a paper feeding device in a printer or the like of the invention. 2. Description of the Related Art Conventionally, in a paper feeding device such as a printer, a driving roller that is driven to rotate and a plurality of driving rollers that are provided apart from each other in the longitudinal direction of the driving roller and rotate in a state of being pressed against the driving roller are used. There is a driven roller that is driven to rotate, and the paper is fed from one side to the other while being held between the two rollers with the rotation of both rollers. (Problems to be Solved by the Invention) However, in the conventional apparatus, the paper is guided from the paper pan to the outer periphery of the driven roller, and the leading end of the paper is supplied between the driving roller and the driven roller by the rotation of the driven roller. When the paper is inserted between both rollers, the leading edge of the paper comes into contact with the junction between the outer peripheral surface of the driven roller and the paper pan and does not reach the contact point of both rollers, and the paper feed is performed. There was a problem that was not. Reducing the distance between the platen and the paper pan increases the possibility that the leading edge of the printing paper will reach the contact point between the platen and the feed roller, but not only increases the frictional resistance between the printing paper and the paper pan. High precision is required for assembling the platen and the paper pan. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a paper feeder capable of smoothly and reliably guiding the leading end of a paper to a contact point between both rollers with a simple configuration. It is in. Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, in the invention, a driving roller that is driven to rotate and a plurality of driving rollers that are provided apart from each other in the longitudinal direction of the driving roller and that are pressed against the driving roller are provided. A driven roller that rotates in accordance with the rotation of the drive roller in a state where
In a paper feeder which is provided downstream of the paper pan and feeds the paper on the paper pan by a driving roller and a driven roller, a small diameter is formed at a part of the driven roller so as to be separated from the driving roller. A small-diameter portion is provided, and the small-diameter portion is formed such that the distance between the outer periphery thereof and the drive roller is smaller than the distance between the paper pan and the drive roller. A flexible paper guide piece that extends from the upstream side in the direction and guides the paper on the surface on the drive roller side was inserted. (Operation) When the paper is inserted between the driving roller and the driven roller from the upstream side in the paper feeding direction, the leading end of the paper is guided along the paper guide piece by the above means. Since the paper guide pieces are inserted into a small diameter portion formed in a part of a driven roller provided apart from each other in the longitudinal direction of the drive roller, the paper guided by the paper guide pieces is reliably driven. It is supplied to the point of contact between the roller and the drive roller. Therefore, it is possible to smoothly and reliably guide the leading edge of the sheet to the contact point between the rollers with a simple configuration. (Embodiment) An embodiment in which the present invention is embodied in a paper feeder of a printer will be described below with reference to FIGS. 1 and 2. FIG. As shown in FIG. 1, the printer main body 1 includes a paper pan 2 having a concave curved surface, and a cylindrical platen 3 as a driving roller is rotatably supported in the main body 1 so as to face the paper pan 2. Have been. The guide shaft 4 is the main body 1
And extends parallel to the platen 3. The carriage 5 is movably supported by the guide shaft 4, and a print head 6 is mounted on the carriage 5 so as to face the platen 3. As shown in FIGS. 1 and 2, the plurality of through holes 7
Opposite to the outer periphery of the platen 3, they are formed at predetermined intervals on the bottom of the paper pan 2. A pair of support walls 8 project from the lower surface of the paper pan 2 on both sides of each through hole 7, and guide grooves 9 extending in the vertical direction are formed on the inner surfaces thereof. A plurality of rubber feed rollers 10 as driven rollers are inserted and supported in the guide grooves 9 of the support wall 8 at both ends of a shaft 11 passing through the center thereof so as to be vertically movable and rotatable.
A pair of large-diameter portions 10a, which are in contact with the platen 3 through the through holes 7, and a smaller-diameter portion 10b located between the large-diameter portions 10a and smaller than the large-diameter portions 10a are formed on the outer periphery thereof. A holding member 12 made of a leaf spring is provided below the paper pan 2 between the two supporting walls 8, and a forked end thereof is connected to a shaft 11 of the feed roller 10.
The feed roller 10 is pressed against and held by the platen 3 by being engaged with the outer periphery of both ends of the platen from below. The diameter of the small diameter portion 10b is determined such that the distance between the outer periphery and the platen 3 is smaller than the distance between the paper pan 2 and the platen 3. Then, as shown by a chain line in FIG.
The printing paper P inserted into the contact point T1 between the platen 3 and the feed roller 10 along the axis of the print head 6 while being pinched between the platen 3 and the feed roller 10 as the platen 3 rotates counterclockwise. Is sent upward from below through a print position opposite to. Flexible thin piece 13 made of synthetic resin as paper guide piece
As can be seen from FIG. 1, at the base end, at least the thickness of the thin piece 13 is embedded and fixed on the upper surface of the paper pan 2 and extends from the upstream side in the paper feed direction to the contact point T1 between the platen 3 and the feed roller 10 side. The feed roller 10 is inserted between the small diameter portion 10 b of the feed roller 10 and the platen 3. Therefore, the thin piece 13 is much closer to the platen 3 than the paper pan 2 at the place where the thin piece 13 rests on the small diameter portion 10b. Therefore, when the printing paper P is inserted between the platen 3 and the feed roller 10 along the paper pan 2, a gap is formed between the paper pan 2 and the platen 3, as shown in FIG. However, there is no danger that the leading end of the printing paper P will contact the contact point T2 between the paper pan 2 and the outer peripheral surface of the feed roller 10, and the platen 3 and the feed roller 10
The platen 3 and the feed roller 10 do not run idle without fail. Therefore, when the leading end of the printing paper P is sent to the printing position facing the print head 6 through the space between the platen 3 and the feed roller 10 with the rotation of the platen 3 thereafter, the leading end of the printing paper P is always The print line is positioned exactly opposite the print head 6. In particular, since the thin section 13 is provided near the large diameter portion 10a of the feed roller 10, the leading end of the printing paper P is smoothly and reliably guided to the contact point T1 between the platen 3 and the feed roller 10. In addition, since the thin piece 13 has flexibility, unlike the case where a rigid body is used as the thin piece 13, even when the thin piece 13 contacts the feed roller 10, the thin piece 13 is easily bent and fed.
It is possible to always obtain a stable feed operation without cutting the 10 or reducing the rotation speed of the feed roller 10. Furthermore, even if the assembling accuracy is somewhat poor, the thin piece 13 bends and absorbs it, so that high assembling accuracy is not required and the assembling becomes easier. (Another Embodiment) Next, another embodiment of the present invention will be described with reference to FIG. 3. In this embodiment, a small-diameter portion of the feed roller 10 is used.
Tapered portions 10c connected to the large diameter portion 10a are formed on both sides of 10b, and both side edges of the thin piece 13 are in contact with the tapered portions 10c. Therefore, in this embodiment, the thin piece 13 is held close to the outer peripheral surface of the platen 3 by contact with the tapered portion 10c of the feed roller 10, and the leading end of the printing paper P is brought into contact with the platen 3 and the feed roller 10. The guidance is more accurately guided to the point T1. The present invention is not limited to the embodiments described above. For example, the present invention may be applied to a paper feeder other than a printer, and the configuration of each unit may be arbitrarily changed without departing from the spirit of the present invention. It is also possible to convert. Effects of the Invention As described in detail above, according to the invention, an excellent effect is obtained in that the leading end of the sheet can be smoothly and reliably guided to the contact point between the rollers with a simple configuration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view showing an embodiment in which the present invention is embodied in a paper feeder of a printer, and FIG. 2 is AA in FIG.
FIG. 3 is a partial sectional view showing another embodiment of the present invention. 2 ... paper pan, 3 ... platen as drive roller,
6 ... print head, 10 ... feed roller as driven roller,
10a: Large-diameter part, 10b: Small-diameter part, 13: Thin section as paper guide piece.

Claims (1)

(57) [Rules for requesting registration of utility model] A driving roller (3) that is driven to rotate, and a plurality of driving rollers (3) that are provided apart from each other in the longitudinal direction of the driving roller (3) and that are driven by the rotation of the driving roller (3) while being pressed against the driving roller (3). A rotating driven roller (10) is provided downstream of the paper pan (2), and the paper (P) on the paper pan (2) is driven by the driving roller (3) and the driven roller (10).
And a small-diameter portion (10b) formed with a small diameter so as to be separated from the driving roller (3) at a part of the driven roller (10). Part (10b), its outer circumference and drive roller (3)
Is formed to be smaller than the distance between the paper pan (2) and the driving roller (3), and between the small-diameter portion (10b) and the driving roller (3), the upstream side in the paper feeding direction. A sheet guide piece (13) having flexibility and for guiding the sheet (P) at a surface extending from the drive roller (3) and guiding the sheet (P) is inserted.