JP3574291B2 - Printer paper holding mechanism - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a paper holding mechanism that guides a sheet to a print head while holding the sheet floating.
[0002]
[Prior art]
In recent years, printers have been required to have a function capable of recording and writing from the leading edge of a sheet without a margin.In order to respond to such a demand in an ink jet printer, particularly in a print head section. Means are needed to prevent the paper from floating.
[0003]
As the pressing means for the leading edge of the paper, a paper pressing roller or a paper pressing plate has been used so far.In the former, however, the paper can be guided while being pressed smoothly, but the diameter of the roller must be reduced. Because there is a limit to making the paper smaller, it is not possible to guide the leading edge of the paper to the position just before the upper side of the print head without floating the paper. Although it can be guided without being lifted, it is difficult to adjust the pressing force for each sheet.Therefore, there is a problem that a large load is applied to the sheet feeding especially when thick sheets are used. are doing.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a new paper guide capable of smoothly leading the leading edge of a sheet to a position immediately upstream of the print head regardless of the thickness of the sheet. An object of the present invention is to provide a paper holding mechanism for a printer.
[0005]
[Means for Solving the Problems]
That is, the present invention provides a paper holding mechanism for a printer as a paper holding mechanism for achieving the above object, on a paper holding plate provided in a row in parallel with the axis of the paper feed roller and immediately upstream of the print head in the paper conveyance direction . A plurality of small-diameter and short-sized paper pressing rollers provided in the window hole and a plurality of paper pressing rollers held at both ends by a biasing force of a spring member acting on a central portion in the longitudinal direction toward the paper feed roller. And the roller shaft.
[0006]
[Action]
With this configuration, the paper is smoothly conveyed while pressing the paper equally in the width direction by a large number of paper holding rollers, and at the same time, the paper is kept constant at the leading end of the paper holding plate by these rollers regardless of the paper thickness. And smoothly guide it to the position immediately upstream of the print head.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Therefore, embodiments of the present invention will be described below.
The drawings all show one embodiment of the present invention.
First, the overall structure of the paper holding mechanism will be described with reference to FIG.
[0008]
A large number of small-diameter and short-sized paper pressing rollers 15 # are supported in parallel with the axis of the paper feed roller 20 on the paper pressing plate indicated by reference numeral 1 in the drawing. The paper is fed while being pressed by a biasing force of a paper pressing spring 13 acting for each roller 15 # toward a paper feed roller 20 disposed in the immediate vicinity of the print head (not shown) on the upper side in the paper transport direction. It is configured to press the peripheral surface of the roller 20 and guide the sheet to the print head while controlling the pressing force of the leading edge of the sheet holding plate 1 with the sheet holding roller 15 # as a reference. Have been.
[0009]
Next, the details of the paper holding mechanism will be described with reference to FIGS. 1 and 2 which show enlarged main parts of the paper holding mechanism. The paper holding plate 1 has an extremely high rigidity and is made of an extremely thin metal plate material. It is formed as a member corresponding to the length of the paper feed roller 20. On this surface, a large number of window holes 2 # for arranging each paper holding roller 15 # are punched in parallel with the axis of the paper feed roller 20. Further, both sides of these window holes 2 are raised upward, and these rising pieces 3 # are provided with upward U-shaped bearing concave portions 4 #. Are formed so as to support each shaft 16 # supporting the paper pressing rollers 15, 15.
[0010]
On the other hand, as shown in FIG. 2, the front end of the paper presser plate 1 is folded on the rear upper surface, and the folded back portion has a smooth paper presser edge 5 in a direction parallel to the axis of the paper feed roller 20. Further, the folded portion is extended rearward from between the window holes 2 and 2 to correspond to the end of the paper pressing roller shaft 16 of the extended portions 6 and 8. Each tip portion 6 is raised upward, and this portion is used as a restricting piece 7 that presses the axial deviation of the paper pressing roller 15, while the other portion extends toward the center of the paper pressing roller shaft 16. The leading end of the portion 8 rises upward at a portion beyond the paper pressing roller shaft 16 to form a spring receiving recess 9 at the center in the width direction.
[0011]
On the other hand, the rear end of the paper presser plate 1 is folded forward at a portion corresponding to the above-described regulating piece 7, and the leading end of the folded piece 10 is fixed to the paper guide plate 22 with the screw 11, and the spring The portion corresponding to the receiving concave portion 9 is left as a flat surface, and the leading end of the paper pressing spring 13 whose one end is fixed to the frame 24 is guided to the above-mentioned spring receiving concave portion 9 through this flat surface to be positioned and locked. The front end of the paper holding plate 1 is positioned via the shaft 16 at a position immediately upstream of the print head in the paper transport direction.
[0012]
In the drawing, reference numeral 17 denotes a rubber material that covers the peripheral surface of the paper pressing roller 15, and reference numeral 26 denotes a lower paper guide disposed from the upper side in the paper transport direction toward the paper feed roller 20. Shows a plate.
[0013]
The paper press main body thus configured is supported by a small-diameter and short-sized paper press roller 15 し た supported by a paper press spring 13 作用 acting on each paper press roller shaft 16. The paper is uniformly contacted with the entire surface of the paper, and is brought into pressure contact with the peripheral surface of the paper feed roller 20. Further, the paper feed roller 15 # maintains a constant gap between the paper regardless of the paper thickness. Thus, the leading edge of the sheet is held down by the sheet pressing edge 5, and the sheet is guided to the immediate vicinity of the print head without causing the sheet to float.
[0014]
【The invention's effect】
As described above, according to the present invention, a large number of small-diameter and short-sized paper pressing rollers are supported on a paper pressing plate having a leading edge of the paper pressing edge positioned in the immediate vicinity of the print head, and these rollers feed the paper. Since the pressing force is applied to the rollers, the entire width direction of the paper fed to the recording / writing section can be smoothly transported while uniformly pressing the paper pressing rollers onto the paper feeding rollers by the paper pressing rollers. At the same time, regardless of the thickness of the paper, these paper holding rollers keep the space between the paper holding plate and the paper constant, and while holding the rising of the paper with the paper holding edge at the leading end, transfer this to the recording / writing section. Can be sent reliably.
[0015]
In addition, the front end of the paper presser plate is folded back and its folded part is used as a paper presser edge, which makes it possible to attach a radius to the paper presser edge, thereby eliminating the possibility of catching on paper and folding. Since the leading end of the overlapped portion is a shaft supporting portion of the paper pressing roller, these paper pressing rollers can be simultaneously supported by processing only the paper pressing plate.
[Brief description of the drawings]
FIG. 1 is an enlarged top view showing a main part of a paper press forming an embodiment of the present invention.
FIG. 2 is an enlarged side view showing a main part of the paper press.
FIG. 3 is a top view showing the entire paper press.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper press plate 4 Bearing recess 5 Paper press edge 13 Paper press spring 15 Paper press roller 20 Paper feed roller

Claims (3)

The small-diameter and short paper holding rollers held at both ends of the plurality of roller shafts are parallel to the axis direction of the paper feed roller through a window hole on the paper holding plate provided in the immediate vicinity of the print head on the upper side in the paper conveyance direction. And a spring member that is arranged to rotate in contact with the peripheral surface of the paper feed roller and that urges each of the roller shafts toward the paper feed roller at a central portion in the longitudinal direction. A paper holding mechanism for a printer. The paper tip end of the presser plate folded behind the upper surface of the paper pressing plate, according to claim 1, wherein the printer paper pressing mechanism, characterized in that the folded portion and the paper pressing edge. The distal end portion of the paper pressing plate folded behind the upper surface of the paper pressing plate, while the restriction piece to Tachinobo up form for pressing the shift of the roller shaft portions corresponding to the ends of the roller shaft, said roller shaft 2. A paper holding mechanism for a printer according to claim 1, wherein a concave portion for receiving said spring member is formed in a portion corresponding to a central portion in a longitudinal direction of said printer.

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