JPS5859135A - Paper feeder - Google Patents

Abstract

PURPOSE:To improve separability of paper and prevent deterioration of picture quality, in a paper feeder of facsimile and the like having a brake member attached bracket, by forming a brake member opening to a larger width than of a separator roller, placing the point end of said opening in the upstream from the separator roller and providing this brake member opening to said bracket. CONSTITUTION:A point end 38a of an opening 38 is located slightly in the upstream position from a separating part B with respect to the conveying direction IV of document paper, while a rear end edge 38b of the opening 38 is placed in the upstream position from a protruding position A of a separator roller 4 with respect to the feed direction of the paper, further width of the opening 38 is larger than width of the roller 4, then the opening 38 is provided in a bracket 37. In this way, a document bundle 2 is placed on a loading table 3, if it is fed, a brake plate 6 is deformed into the opening 38 in accordance with movement of the point end of the document 2, and action of force separating the bracket 37 can be prevented, then a decrease of separating capability due to a pressure decrease of the brake plate 6 and the separator roller 4 can be prevented. Thus a stable separative feed can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sheet loading table for loading a bundle of sheets;
A separating roller is placed in front of the sheet placing table, and a part of the surface thereof protrudes above the sheet placing table, and a brake member that forms a separating part between the separating roller and the separating roller by being in pressure contact with the separating roller is attached. The present invention relates to a paper feeding device having a bracket.

The paper feeding device is for feeding sheets such as original documents to a device such as a facsimile machine.

FIG. 1 is a sectional side view of a main part of a transmitting section of a facsimile machine to show an example of a conventional paper feeding device.The conventional paper feeding device will be explained below based on this drawing. In the figure, the paper feeder 1 includes a sheet loading table 3 on which a bundle of originals (sheets) 2 is placed, a separating roller 4 arranged at the front of the sheet loading table 3, and a rotating shaft 50. A bracket 7 that is possible and has a brake plate (brake member) 6 affixed to its lower surface.
and a press plate 10 which is rotatable around a support shaft 80 and presses the bracket 7 and therefore the brake plate 6 against the separation roller 4 under the action of a spring 9. The roller 4 and the brake plate 6 are made of a high friction material such as rubber.

A reading device 11 is arranged in front of the paper feeding device 1. This reading device 11 includes a step motor 13 that intermittently drives reading rollers 12a and 12b for conveying a document, and reading rollers 1.2a and 1.
2b, and an upper sheet guide 15 for guiding the conveyed document.
It has a lower sheet guide 16, a reader 18 disposed below a glass plate 17 fitted into the lower sheet guide 16, and a sensor 19 disposed above the upper sheet guide 15. Reference numeral 20 indicates the step motor 13
A timing belt is passed between the pulley 21 of the reading roller 12a and the pulleys 22a, 22b of the reading roller 12a, 12b.

12b is driven by the step motor 15 via this timing belt 20.

A sheet guide plate 23 made of Mylar paper or the like is fixed in advance to the rear end of the bracket 7, and the document bundle 2 is guided by the sheet guide plate 25 as it slides onto the sheet loading table 3.
placed on top. The document bundle 2 placed on the sheet mounting table 3 is separated into a wedge shape formed by the brake plate 6 and the separating roller 4 due to counterclockwise rotation of the separating roller 4 with a part of its peripheral surface protruding onto the sheet placing table 6. sent into the gap. Note that the position A where the separation roller 4 protrudes above the sheet mounting table 3 will hereinafter be referred to as the protrusion position of the separation roller.

The wedge-shaped gap is formed by pressure contact between the brake plate 6 and the separation roller 4 under the action of the press plate 10, so that the document bundle that has passed through the wedge-shaped gap then reaches the pressure contact portion B. When the document bundle reaches the pressure contact portion B, only the lowest one of the documents is sent further forward due to the difference between the frictional force between the brake plate 6 and the document and the frictional force between the separation roller 4 and the document. It will be done. In this way, the brake plate 6
Since the pressure contact part B between the and separation roller 4 plays the role of separating only one document from the document bundle 2, this part will be referred to as the separation part B from now on. The separated one sheet of original is sent to the reading device 11
Upper and lower sheet guides 15,
16, and thereafter the reading rollers 12a and 1
2b. The original is read by the roller 12a
When the document is conveyed by the document, the separation roller 4 stops being driven, and thereafter the roller 4 rotates together with the document by the action of the overrunning clutch 250. sensor 1
When the leading edge of the document is detected by 9, a signal to that effect is sent to a facsimile receiving section (not shown), and thereafter, the content of the document read by the reader 24 is sent to the receiving section in synchronization with the reading timing. As described above, in the paper feeding device according to this conventional example, printing is performed.

Separation of the documents is achieved by the difference in the frictional force between the brake plate 6 and the separation roller 4 against the documents constituting the document bundle 2. However, in this conventional device, due to the adhesion force of the leading edge of the originals caused by the frictional force between the originals, the original bundle 2 directly enters the wedge-shaped gap as shown in FIG. 2, and the bracket 7 moves in the direction of the arrow Due to the large force, the pressure between the separation roller 4 and the brake plate 6 decreases, and as a result, the separation ability of this place cannot be achieved, and the separation roller 4 also becomes distorted due to the force in the direction of the arrow ■. Therefore, there are problems such as several sheets of originals falling between the separating roller 4 and the brake plate 6, resulting in multiple sheet feeding.

In order to solve the above-mentioned problems, a method has conventionally been adopted in which the pressing force of the bracket 7 and therefore the brake plate 6 by the press plate 10 is increased, but even in this case, the following problems occur. That is, firstly, the separation roller 4
secondly, the amount of wear on the brake plate 6 and separation roller 4 increases; and thirdly, the load on the separation section B of the document conveyed by the reading rollers 12a, 12bK increases. , a timing lag occurs between the conveyance of the document on the facsimile sending side and the conveyance of the recording paper on the receiving side, resulting in poor image quality of the printed image. -As mentioned above, in this type of conventional paper feeding device, sheets (original documents) are
If the pressure applied is too weak, multiple sheets will be fed, while if the pressure is too strong, it will increase the load, increase the amount of wear, and cause poor image quality.

In order to overcome the drawbacks of the conventional example described above, other types of paper feeding devices such as those shown below have been conventionally known. FIG. 6 is a side sectional view showing the conventional device. In this conventional paper feeding device 31, there is a sheet stopper 6 at a position in front of the separating section B.
2 is placed.

This sheet stopper 32 forms a small gap between it and the separation roller 4, but the reason why the sheet stopper 32 is provided is as follows: This is to prevent the brake plate 36 from being pushed up, in other words, to prevent the pressure between the brake plate 36 and the separation roller 4 from decreasing. The document stack 2 is moved stepwise by the sheet stopper 62, and only the lower few sheets of the document stack 2 are moved to the separating section B by using a small gap between the sheet stopper 32 and the separation row 24. It is planned to be sent.

However, in this type of conventional apparatus, as shown in FIG. 4, the upwardly curled original 2b may hit the sheet stopper 32, resulting in jamming or non-feeding. Furthermore, if more documents than the gap enters the gap between the sheet stopper 32 and the separation roller 4, more than necessary feeding force will be applied to those documents, and as a result,
Multiple sheets are fed. Furthermore, since the angle θ of the sheet stopper 62 is normally set to about 600 -, there is a drawback that the document stack 2 is not smoothly transitioned into a step-like shape at the start of paper feeding, and therefore non-feeding is likely to occur. be. Particularly when using a sheet with a large coefficient of friction between sheets as the original, such as carbonless paper, coated paper such as electrostatic recording paper, or laminated paper.

Non-feeding at the start of paper feeding is likely to occur.

It is an object of the present invention to improve the former type of paper feeder shown in FIG. 1 or 2 of the above two types of conventional apparatuses, thereby eliminating the above-mentioned drawbacks.

Hereinafter, the present invention will be explained based on drawings showing embodiments thereof.

FIG. 5 is a sectional view of a main part of a paper feeding device showing a first embodiment of the present invention. This paper feeding device differs from the conventional example shown in FIG. 1 or 2 in that a bracket 57 is provided with an opening 58. Other points are the same as those of the conventional example, and the same members are designated by the same reference numerals. Opening 3
8, its leading edge 38a is located at a position slightly upstream of the separating portion B in the document transporting direction (sheet transporting direction), while its rear end edge 38b is located at a position slightly upstream of the separation portion B in the document transporting direction (sheet transporting direction). Located upstream.

FIG. 6 is a perspective view showing the bracket 37 etc. in FIG. 5, and as shown in the figure, the width of the opening 68 is wider than the width of the separation roller 4.

Since the paper feeding device according to this example has the above configuration,
When the document stack 2 is placed on the sheet placement table 3, as shown in FIG. 5, the brake plate 6 corresponding to the opening 38 moves in the opposite direction to the separation roller 4, that is, upward in the figure. Slightly depressed. When the separation roller 4 rotates at the start of the paper feeding operation, the document bundle 2 rushes into the wedge-shaped gap formed by the brake plate 6 and the separation roller 24, but in this case, the seventh
As shown in the figure, the brake plate 6 further deforms upward in accordance with the movement of the leading end of the document bundle 2. Due to this deformation of the brake plate 6, the bracket 37 is not subjected to the conventional device (therefore, there is no reduction in separation ability due to a decrease in pressure between the separation roller 4 and the brake plate 6. During the above deformation, the edge portion C formed by the tip edge 38a of the opening 38 and the brake plate 6
The movement of the top few documents is prevented, and only the bottom few documents are efficiently sent to separation section B, resulting in stable separation.
Delivery can be done. Furthermore, in this case, the deformed brake plate 6 presses the document bundle 2 against the separation roller 4 with a slight force, so that the document feeding is further stabilized. As the manuscript is fed, the deformation of the brake plate B gradually returns to its original state, and finally it returns to its initial state. In other words, it serves as a relief part that can allow deformation in the direction opposite to the separation roller 4.

In this embodiment, the width of the opening 68 is determined by the width of the separation roller 4.
(Fig. m'6) is because of the stiffness of the document bundle 2, assuming that the width of the opening 38 is equal to or narrower than the width of the separation row 24. Unnecessary feeding force is generated in the brake plate 6 as in the conventional device (Fig. 2).
This is because a phenomenon occurs in which the bracket 57 is pushed upward and expanded.

Furthermore, the reason why the leading edge 38a of the opening 38 is located at a position slightly upstream of the separation section B in the document conveyance direction (7) is
Figure) Due to the following reasons. That is, if the leading edge 38m is located downstream of the separation part B, as shown in FIG. 8, the contact area between the brake plate 6 and the separation roller 4 becomes larger, so that the separation ability is improved. On the other hand, there is a possibility that the resistance force becomes large and it becomes impossible to feed the document.

On the other hand, if the leading edge 38a is located at an upstream position far away from the separation part B, in this case, the opening 38 would be undesirably affected as in the conventional apparatus, so there would be no point in providing the opening 38. .

Furthermore, the reason why the rear edge 38b of the opening 38 is located upstream of the protruding position A of the separation roller 4 with respect to the document transport direction (Fig. 7) is that there is no unnecessary space between the separation roller 4 and the brake plate 6. This is to prevent the generation of feeding force.

As described above, according to this embodiment, the thrusting force of the document bundle 2 is offset by the deformation of the brake plate 2, and the edge portion C generated by the thrusting force is used to separate only the lower few sheets of documents into the separation section B^. The stabilization of the separation is achieved through feeding. Furthermore, the restoring force of the deformed brake plate 6 can stabilize the document feeding force. Furthermore, the pressure required to separate the documents by the press plate 1o is extremely small compared to the conventional apparatus (FIG. 2), which is advantageous in terms of wear and load.

FIG. 9 shows a second embodiment of the present invention, in which a leaf spring 39 is disposed within the opening 38 of the bracket 37 and extends from the rear edge 38b of the opening 38. As shown in FIG. Furthermore, an adjustment screw 41 screwed into an arm 4o fixed on the bracket 37 is arranged above the leaf spring 39. With this configuration, the restoring force of the brake plate 6 can be set arbitrarily, so that the document feeding force can be further stabilized.

FIG. 10 shows a sixth embodiment of the invention.

In this example, it is attached to the bracket 37. The brake plate 46 has several pieces (three pieces in the figure) extending in the direction of document conveyance.
The grooves 42 are provided, and the tips of these grooves 42 are open ends 42a.

Thereby, the amount of deformation of the brake plate 46 can be arbitrarily set depending on the material of the brake plate 46, for example, the hardness of the rubber.

FIG. 11 shows a fourth embodiment of the invention.

In this case, the bracket 47 is provided with a step 48 instead of the opening as a relief part that can allow deformation of the brake plate B. As a result, not only the same effects as the openings in the above embodiments can be obtained, but also the strength of the bracket 470 can be improved. In addition, step 4
8, its leading edge 48a is located at a position slightly upstream from the separation part B in the document conveyance direction (2), and its rear end edge (joint position with the brake plate 6) 48b is located at a position upstream from the protruding position A of the separation roller 4. The opening 38 is the same as the opening 38 in each of the embodiments described above, and the width thereof is wider than the separation roller 4.

In each of the above embodiments, the angle θ formed by the brake plate 6 or 36 and the sheet mounting table 6 is relatively small, for example, 15
It is desirable that the angle is about 30° to 30°.

The reason is that, firstly, even if you try to feed the raw material 142a that has a slight upward curl as shown in FIG.
Second, as shown in FIG.
By the way, if there is a stack of originals 2 that is slightly curled upwards on the sheet tray 3,
6. Even when the sheet is set, the restoring force of the brake plate 6 acts as shown by the arrow (as shown by the arrow) to correct the curl, so stable feeding can be obtained.

As shown in FIG. 15, since the angle θ is small, the document bundle 2 tends to form a south-stage shape, and therefore the documents can be separated smoothly.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main parts of a facsimile transmission section showing an example of a conventional paper feeding device, Fig. 2 is a cross-sectional view showing an enlarged main part of Fig. 1, and Fig. 3 is a cross-sectional view of another conventional example. FIG. 4 is a diagram showing a state in which slightly curled paper is applied to the conventional device shown in FIG. 3, and FIG. 5 is a cross-sectional diagram showing the first embodiment of the present invention.
FIG. 6 is a perspective view thereof, FIG. 7 is a sectional view showing the operating mode of the first embodiment, and FIG. 8 is a sectional view showing an inappropriate example of the position of the opening on the third day in FIG. , FIG. 9 is a sectional view showing a second embodiment of the invention, FIG. 10 is a sectional view showing a sixth embodiment of the invention, FIG. 11 is a sectional view showing a fourth embodiment of the invention, and FIG. FIG. 12 is a sectional view for explaining the angle θ between the brake plate and the sheet mounting table in each of the above embodiments, and FIG. 13 is a sectional view for explaining the angle θ as well. 2... Sheet bundle (original stack) 3... Sheet mounting table 7
, 57.47... Brackets 38b, 48b... Rear edge Fig. 1 Fig. 6 Fig. 7 Fig. 8 °"' Fig. 9 7 Fig. 10 Fig. 11 Fig. 12 %I Fig. 13

Claims (3)

[Claims] (1) A sheet loading table for loading a sheet bundle;
A separating roller is placed in front of the sheet placing table and a part of the surface thereof protrudes above the sheet placing table, and a brake member is attached that forms a separating part between the separating roller and the separating roller by coming into pressure contact with the separating roller. In the paper feeding device, a relief portion is provided in the bracket to allow deformation of the brake member in a direction opposite to the separating roller, and the width of the relief portion in a direction perpendicular to the sheet conveyance direction is separated. The width of the relief part is wider than the width of the roller, the leading edge of the relief part is slightly upstream of the separation part in the sheet conveyance direction, and the rear edge of the relief part is on the sheet mounting table of the separation roller in the sheet conveyance direction. A paper feeding device characterized in that it is located at a -E flow position from a protruding position. (2) The paper feeding device according to claim 1, wherein the relief portion is an opening provided in a bracket. (3) The paper feeding device according to claim 1, wherein the relief portion is a step of a bracket.