JPH03166141A - Sheet feeder - Google Patents

Abstract

PURPOSE:To easily carry out accurate sheet feeding without skew generated even when sheets of different widths are used by furnishing a movable guide between a sheet feed roller and a separator pawl. CONSTITUTION:In the loop forming division ST a sheet of paper P1 moves upon obtaining a feeding force from a feed roller 1, wherein the two corners of the leading edge remain out of moving because they are in contact with separator pawls 3, 4, and a loop is formed between the feed roller 1 or a movable guide 7 and the separator pawls 3, 4. Meantime the movable guide 7 contacts the sheet P1, guides it, and restricts widening of the loop, wherein no greater load will be applied because the position is such as to allow maintaining a minor gap to the bundle of sheets P situated below this sheet P1, to ensure that the loop is formed in good performance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application II) The present invention is applicable to printers that use cut sheets of multiple paper widths (hereinafter referred to as paper), and in particular, to printers that use cut sheets with multiple paper widths (hereinafter referred to as paper), and in particular, to Specify printer paper feed! ! Regarding the location. [Prior Art] A device installed at both corners of the leading edge of river paper is used as a device to separate sheets of paper placed on a paper table one by one and feed them to the main paper feeding means provided in the printer body. A device for separating a pair of separation claws is known and has been commonly used. As shown in FIG. 9, this device has an hI
I! The stack of paper sheets P is pressed against the paper feed roller 22, and the second-most paper Pi that is in contact with the paper feed roller 22 is sent in the direction of the arrow. A loop Ll.
L2 is formed, and the paper Pi is divided into parts by utilizing the fact that both corners of the leading edge of the river paper P1 overcome the separating claws 3 and 4 due to the restoring force of the river paper P1. Reference numeral 5 designates a paper case for storing the paper east P, to which a paper table 2 and separation claws 3 and 4 are attached; 20 a spring member that urges the paper table 2 in the direction of the paper feed roller 22; and 21 a separation member. This is a spring member that presses the claw 3.4 against the paper stack P. In this way, since the conventional device utilizes the restoring force of the lubes Ll and L2 formed by the pair of separating claws 3.4,
In order for the river paper P1 to be fed accurately without skewing, both corners of the leading edge of the river paper P1 must pass over the left and right separating claws 3 and 4 at approximately the same timing, and the lube Ll, L2
It is necessary to make them almost the same shape. That is, the paper feed roller 22 had to be located at approximately the same distance from the minute Aα claw 3.4 or both ends of the paper east P. In addition, as shown in Japanese Utility Model Application Publication No. 53-142344, conventional paper feed rollers having a roughly D-shaped cutout with a part of the circumference cut out have been developed to improve the operability of paper cassettes and to facilitate manual insertion. It was used to secure a paper path between the paper stack and the paper feed roller. [Problems to be Solved by the Invention] However, such conventional paper feeding devices have the following problems when using paper of multiple paper widths. For example, B5 (paper 1+'+ 1 8 2 mm),
When feeding two sheets of A4 paper (paper width 210 mm), if you align the paper feed roller 22 with B5, which has a narrow paper width, as shown in Figure 10, the paper will not be fed when you try to feed A4 paper. Roller 22 and minute N [distance between claws 3 and 4 is 28 mm on the left and right]
Also, even if the paper feed roller 22 is aligned with the wide A4 paper as shown in Fig. 11, if you try to feed B5 paper, the separation timing of the left I-1 will be different. Similarly, the timing of separating the left and right sides was different, and no matter which paper was aligned, one side was skewed. Therefore, a special mechanism was installed to adjust the position of the paper feed roller according to the paper width. The paper cassette had to be moved, which not only made it difficult to easily realize a small paper cassette, but also became a hindrance to lowering prices. The left and right loops can be made to have almost the same shape by providing a guide 23 that regulates the paper stack, but since the guide 23 must be placed close to the paper stack P, it not only impedes the operability of the paper cassette. , there is a problem that manual feeding becomes impossible. Therefore, the present invention solves this problem, and allows accurate paper feeding without skew even when using several types of paper with different paper widths. It is an object of the present invention to provide a low-cost paper feeding device that is excellent in paper cassette operation, has good manual feeding performance, and has a low cost. Using a paper feed roller with a roughly D-shaped cross section with a cutout, the paper feed roller and the paper stacked on the paper tray face each other without contact when not in operation, and the paper feed roller and paper come into contact only when in operation. In a paper feeding device that feeds paper one sheet at a time while facing each other, the paper feeding device has separation claws that are installed at both corners of the leading edge of the paper in the feeding direction and separate the sheets one by one. A movable guide member is placed between the paper feed roller and the separation claw during the period from when it starts contact with the roller until it is separated by the separation claw, and moves to a position where it guides the paper. [Embodiment] An example of one cell according to the present invention will be explained below. Fig. 1 is a side cross-sectional view showing the main points of a printer using the paper feeding device according to the present invention. 1 is a perspective view showing the structure of a paper cassette that is fed into a paper feeder according to the present invention. 1 is a paper feed roller with a cutout shape with a part of the circumference cut out; 2 is a paper feed roller with a cutout shape; The paper table on which the East P is loaded, 3.4 are the top corners H of the paper East P.
5 is a paper case, and 6 is a paper cover. The paper tray 2 is pushed toward the paper feed roller 1 by a spring member 20. The separation claw 3.4 is pressed against the paper east P by a spring member 21 with an extremely small amount of 6 Um. The paper case 5 has a separating claw 3.4 stopper 5.
-a is provided, and when the notch of the paper feed roller 1 is facing the paper stack P, the separation claw 3.4 and the stopper 5-a come into contact, and the feed roller 1 (roller 1 and the top paper P1
This prevents them from coming into contact with each other. A movable guide 7 is guided by a shaft 8 and a paper feed roller shaft 9 and supported so as to be movable in the directions of arrows A and B. Reference numeral 10 denotes a manual feed guide, which together with the paper cover 6 constitutes a manual paper path 10a.

A platen 12 receives driving force from a drive motor (not shown) and serves as the main paper feeding means together with the presser roller l3. Reference numeral 14 denotes a pair of paper ejection rows, which eject the printed paper P2 to a paper receiver 15''2. 16 is a paper guide, 17 is a paper discharge guide, and 18 is a print head. In such a printer, the paper feed roller 1 has a recessed portion 1a facing the river paper east P and Jl' when the paper feed roller 1 is not ribbed. In the case of automatic paper feeding, the paper feed roller 1 starts rotating in the direction of the missing mark C, and while the paper feed roller rotates once continuously or intermittently, the topmost paper P1 of the paper stack P moves in the direction of the arrow D. The paper is sent out like this and is fed to the main paper feeding means. When feeding paper manually, the paper feed roller 1 does not operate and the cutout portion 1a faces the paper bundle P without contacting it. Therefore, the manual feed paper P3 is guided by the paper cover 6 and the manual feed guide 10 as shown by the arrow E, passes between the paper feed roller l and the paper stack P, and reaches the main paper feeding means. Also,
Paper? When feeding paper or replacing paper, the paper cassette, which is made up of a paper case 2, a paper cover 6, a paper table 2, and separation claws 3 and 4, is removed by pulling it out in the direction of arrow F. Figure 3 is a perspective view showing the deformation of the movable guide 7;
The figure is a partially enlarged side view showing the positional relationship between the paper feed roller 1 and the movable guide 7 when not in operation, and FIG. 7
FIG. 2 is a partially enlarged side view showing the positional relationship of the A cam 11 rotates integrally with the paper feed roller 1, and in this embodiment, it is fixed to the liner roller shaft 9.
If the cam operates in synchronization with the paper feed roller 1, there is no problem even if it is not on the paper feed roller shaft 9. The movable guide 7 is provided with a follower 7l that engages with the cam l1, and moves in the directions of arrows A and B in synchronization with the rotation of the paper feed roller 1.
72 is a spring member that biases the movable guide 7 in the direction of arrow B. When not in operation, the movable guide 7 is at a distance M from the paper east P that is approximately equal to or slightly m from the notch 1a of the paper feed roller 1, as shown in FIG. 5
Move to a position slightly away from the paper stack P as shown in the figure. Figure 6 shows B5 (paper width 182mm), A4 (paper width 2mm),
Positions of the paper feed roller 1, separation claws 3 and 4, and movable guide 7 when using three types of paper: 10mm) and B4 (paper width 257mm) with one edge of the paper IA standard (separation claw 3 standard) FIG. #@Paper roller l is located at the same distance a from the female claws 3 and 4 based on the narrowest B5 paper, at a distance b from the A4 separation claw 4, and at a distance b from the B4 separation claw 4. A movable guide 7 is provided at each position b. The distance ab is almost equal to the distance 811a, but considering that the movable guide 7 has a small gap with the paper bundle P,
It is set slightly shorter. In such printing, the lining roller l is rotated,
If you try to feed I in the direction of the missing mark in the diagram, minute #la
Since the claws 3.4 are located at both ends (paper width direction) of the river paper P1, the lube L1 is located between the separation claw 3 and the paper feed roller l, as shown in FIGS. 7(a) to (C). , the loop L2 is formed between the minute M claw 4 and the paper feed roller 1 or the movable guide 7 located closest to the minute M claw 4. Therefore, regardless of the paper width of the paper, the loops Ll and L2 are approximately the same. It becomes the shape,
The paper PI passes over the separation claws 3.4 almost simultaneously on the left and right sides and is separated well. The two-dot chain lines in Fig. 7 (a) to (c) are
The shape of the loop without the movable scarecrow 7 is shown. Dividing nails 3
, 4, the distance a is from 10 mm to 30 mm.
mm is appropriate, and it is good if the distance Mb is 0.5 mm to 2 mm shorter than the distance Ma. FIG. 8 is a timing diagram explaining the operation of the paper feed roller 1 and the movable guide 7. The horizontal axis is the four-turn angle of the paper feed roller or the time from the start of rotation, and the vertical axis is the paper feed roller 1, the movable guide This is the distance between the guide 7 and the paper bundle P, and the position of the leading edge of the paper P1 near the separating claws 3 and 4.
Timing R is the timing when the paper feed roller 1 starts rotating in response to the paper feed signal, and the paper feed roller L and the movable guide 7
is in the non-operating state as shown in Figure 4. In this state,
The cutout portion of the paper feed roller 1 faces the paper stack P, and the movable guide 7 is also retracted while maintaining a sufficient distance from the paper stack P. Further, the leading edge of the uppermost sheet P1 of the sheet east P hits the separating claws 3.4 at both corners, and is stopped at a predetermined position. The period from timing R to timing S is an idle period, during which the movable guide 7 moves in the direction of the paper bundle P, and the M paper roller l
At timing S when the sheet P1 starts contacting the sheet P1, the sheet P1 has reached a position where it faces the sheet P1 while maintaining a slight gap. The period from timing S to timing T is a loop forming section, and the paper P1 moves by receiving the feeding force from the &8 paper roller 1, but the two corners of the tip do not move because they are in contact with the separation claws 3.4, and the paper is fed. A loop is formed between the roller l or movable guide 7 and the separating claw 3.4. During this time, the movable guide 7 contacts and guides the paper P1 to restrict the spread of the loop, but since it is in a position that maintains a slight gap from the paper stack P located below the paper P1, there is no significant load. A good loop can be formed. The two-dot chain line in the figure shows the leading position near the center of the paper, that is, the position of the leading edge when there is no separating claw 3.4. Timing T is the timing at which both corners of the leading edge of the paper P1 pass over the separation claws 3.4 (the paper P1 is separated), and the movable guide 7 continues to maintain a small gap between itself and the paper P. There is. The period from timing T to timing U is a feeding section in which the paper P1 is fed to the main paper feeding means. At timing U, the contact between the paper feed roller 1 and the paper P1 ends, and the paper feed roller 1 starts from timing U. Until timing V, it idles for reset. During the feeding section, the movable guide 7 moves as shown by the solid line in the figure and retreats to the same position as in the non-operating state. By changing the shape of the cam 11, the movable guide 7 can be retracted during the idling section as shown by the broken line in the figure, or can be retracted over both sections. As described above, the movable guide 7 makes one reciprocation during one rotation of the paper feed roller l, guides the paper Pi only in the direction of the movement of the paper feed roller l, and the paper 5l! Accurately divide paper P by M from P. [Effects of the Invention] As described above, by providing a movable guide between the paper feed roller and the separation claw, accurate paper feeding without skew can be easily performed even when multiple types of paper with different paper widths are used. This is possible, and there is no need to change the position of the paper feed roller depending on the paper width.
A low-cost paper feeding device using a paper cassette can be easily realized. In addition, the movable guide moves to the position where it guides paper only when the paper feed roller is in operation, and is retracted to a position sufficiently far away from the paper stack when it is not in operation, causing problems when attaching/detaching the paper cassette or inserting paper manually. Therefore, it is possible to easily realize a paper feeding device with excellent operability of the paper cassette and easy manual insertion.

[Brief explanation of the drawing]

FIG. 1 is a schematic side sectional view of a printer using a paper feeding device according to one embodiment of the present invention, FIG. 2 is a perspective view of one embodiment of a paper cassette used in the paper feeding device according to the present invention, and FIG. The figure is a perspective view of one embodiment of the paper feed roller and movable guide of the paper feed device according to the present invention, and FIGS. 4 and 5 are sectional views explaining the operation of the paper feed roller and movable guide of the paper feed device according to the present invention. FIG. 6 is a model diagram showing one embodiment of the positional relationship of the paper feed roller, movable guide, and separation claw of the paper feed device according to the present invention, and FIGS. 7(a) to 7(a)-
(C) is a model diagram showing how the paper feeder according to the present invention separates sheets; FIG. 8 is a timing chart showing how the paper feeder according to the present invention operates; FIG. 9 is a perspective view of the conventional example; 10
．． Figure 11.12 is a model diagram of the conventional example. l...Paper feed roller 2...Paper table 3, 4...Distribution claw 5...Paper case 6...Paper cover 7...Movable guide 8...Shaft 9...Paper feed Roller shaft 10...Manual feed guide 11...Cam 12...Platen 13...Press roller 14...Pair of paper ejection rollers 15...Paper receiver 16...Paper guide 17... Paper ejection guide 18...Print head 20, 21.72...Spring member 71...Follower 22...Paper feed roller 23...Guide P...Sheet of paper

Claims (1)

[Claims] Using a paper feed roller with a roughly D-shaped cross section with a part of its circumference cut out, the paper feed roller and the paper stacked on the paper tray face each other without contact when not in operation, and only when in operation. A paper feeding device that feeds the paper one sheet at a time by bringing the paper feeding roller and the paper into contact with each other, and is installed at both corners of the leading edge of the paper in the feeding direction and separates the paper one by one. In a paper feeding device having a separating claw, the paper is located between the paper feeding roller and the separating claw for at least a period from when the paper starts contacting with the paper feeding roller until it is separated by the separating claw. A paper feeding device comprising a movable guide member that moves to a position where the paper is guided.