JPH0524695A - Automatic paper feeding device - Google Patents

Abstract

PURPOSE:To open the part between a reverse revolution roller, separating roller and a feed roller without installing a complicate drive connecting/disconnecting mechanism. CONSTITUTION:An automatic paper feeding device is equipped with a separating roller 25, reverse revolution roller 1 which contacts the separating roller 25, feeding roller 26 which revolves in the same direction as the separating roller 25, and a pinch roller 2 which revolves in interlocking with the feed roller 26, and a drive transmission means T for transmitting the drive power to the reverse revolution roller 1 from the pinch roller 2 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverse roller type automatic paper feeder used for reading originals in facsimiles, copying machines and the like.

[0002]

2. Description of the Related Art Conventionally, as a structure of a reverse roller type automatic paper feeder (hereinafter referred to as a reverse ADF), Japanese Patent Publication No. 1-33412 (FIG. 12) and Japanese Patent Publication No. 61-27299.
As shown in FIG. 13, many proposals have been made in which the driving of the reverse rotation roller 101 is separated from the driving of the feed roller / separation roller 125.

Further, conventionally, a separation roller and a reverse rotation roller,
Furthermore, an automatic paper feeder that separates and feeds paper sheets one by one in cooperation with a torque limiter is widely known, and theoretical formulas about the torque limiter set value for cooperation and the frictional force of each roller are presented. ing.

[0004]

However, in the above-mentioned conventional example, since the drive of the reverse rotation roller 101 is separate from the drive of the feed roller / separation roller 125, there are the following drawbacks. (1) The reverse rotation roller 101 and the separation roller / feed roller 125 must be opened so as to clear the jam of the document and maintain the ADF. In order to take this structure in the conventional reversing type ADF, it is necessary to have an independent drive source (motor) on each of the reversing roller 101 side and the separating roller / feeding roller 125 side, which is an expensive apparatus. (2) In order to use one drive source, a complicated drive connection / disconnection mechanism must be provided, which is expensive and prone to failure.

Further, regarding the theoretical formula for the frictional force, even if the above-mentioned respective values are set according to the theoretical formula, the respective set values are actually changed due to variations in manufacturing of the torque limiter and the roller and changes with time. It may fluctuate and the desired separation / feeding performance may not be obtained. Above all, the friction coefficient of each roller has a large variation in manufacturing and the difference among various paper sheets, and a sorting step and an adjusting step such as pressing force of the roller are required, so that an increase in manufacturing cost cannot be avoided.

Particularly, in the case where the driving of the reverse rotation roller is transmitted from the pinch roller, the friction coefficient of the pinch roller and the feed roller is also related to the separating / feeding performance, and the theoretical formula itself becomes complicated. It was becoming more and more difficult to overcome the drawbacks (unstable separation / feeding performance and increased manufacturing cost).

The present invention has been made to solve the above problems, and its object is to open the space between the reverse roller and the separation roller / feed roller without providing a complicated drive connection / disconnection mechanism. The present invention is to provide an automatic paper feeder.

Another object of the present invention is to provide an automatic paper feeding device in which the frictional force between the rollers is maintained at a predetermined value even if variations occur in the manufacturing process of the rollers.

[0009]

In order to achieve the above object, in the present invention, a separating roller for feeding a sheet and a reverse rotation for contacting the separating roller and rotating in a direction opposite to the sheet feeding direction. An automatic paper feed having a roller, a feed roller located downstream of the separation roller in the sheet feeding direction and rotating in the same direction as the separation roller, and a pinch roller that contacts the feed roller and rotates with the feed roller. In the device,
Drive transmission means for transmitting power from the pinch roller to the reverse rotation roller is provided.

It is desirable that at least two of the separation roller, the reverse rotation roller, the feed roller and the pinch roller are made of the same material.

Further, it is preferable that the separating roller, the reversing roller, the feeding roller and the pinch roller made of the same material have the same shape.

It is desirable that at least two or more of the separation roller, the reverse roller, the feed roller, and the pinch roller are formed of rubbers of the same type but different in hardness.

A torque limiter may be included in the drive transmission means.

[0014]

In the present invention having the above construction, the reverse rotation roller is driven through the pinch roller which is arranged so as to face the feed roller. That is, the drive transmission means from the pinch roller to the reverse rotation roller is integrated into an independent unit, and the drive force is transmitted from the feed roller by the frictional force between the pinch roller and the feed roller. Further, since the frictional force is transmitted in order from the feed roller to the original and from the original to the pinch roller during the conveyance of the original, the drive of the reverse rotation roller is not interrupted.

When the reverse rotation roller side is opened, it is sufficient to lift the above independent unit and disconnect the contact between the pinch roller and the feed roller.

Further, by forming at least two of the separating roller, the reverse roller, the feed roller and the pinch roller from the same material, even if there is a manufacturing variation in the material, the frictional force of each roller is increased. Does not change and the separation / feeding performance does not deteriorate.

Further, if not only the material but also the shape is made the same, it is possible to use a common component for each roller, so that the influence of the fluctuation of the frictional force is further reduced.

If the material is rubber, not only the same material but also the same kind but different hardness has the same effect as above. In general, the same type of rubber has the property that the low hardness has a higher friction coefficient than the high hardness, and the fluctuation of the friction force can be suppressed to a low level as long as the hardness is managed. is there.

Further, when the torque limiter is provided, slippage between the reverse rotation roller and the separation roller and between the reverse rotation roller and the sheet is eliminated.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of an essential part of a portion for sending a paper sheet document to an image reading portion when an automatic paper feeding device according to the present invention is applied to a facsimile device.
1 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is a view taken in the direction of arrow B of FIG. 1, and FIG. 11 is a cross-sectional perspective view.

In these figures, 1 is a reverse roller, 2
Is a pinch roller, and both 1 and 2 are made of the same silicone rubber as the separating roller 25. 3, 4, 5, 6, and 7 are gears that transmit the drive from the pinch roller 2 to the reverse rotation roller 1,
8, 9, 10, 11 are reverse rotation rollers 1, pinch rollers 2,
The shafts of the gears 3 to 7, 12 and 13 are side plates made of polyacetal, 14 is a stay, 15a and 15b are rollers through which the shaft 9 is passed, 16a, 16b, 16c and 16d are shaft 8 and stay 1.
4 is a screw for fixing 4 to the side plates 12 and 13, and
16 constitutes an independent unit (hereinafter referred to as a reverse rotation roller unit).

Reference numeral 17 is an upper original guide, and 18a and 18b are leaf springs which press the pinch roller 2 against the feed roller 26 through rollers 15a and 15b, and 19 is a leaf spring rear 18a and 18b.
b is supported by the upper document guide 17 with the screw 20 and thereafter, 21a and 21b are front plate springs for pressing the reverse roller 1 against the separation roller 25 via the shaft 8, and 22 is front plate springs 21a and 21b. In front of a leaf spring stay supported by a screw 23 on the guide 17, 24a and 24b are guides made of a low-rigidity member arranged on the left and right of the reverse rotation roller 1, 27 is a spindle of the separation roller 25, 28 is a spindle of the feed roller 26, Two
Reference numeral 9 is a lower original guide. The feed roller 26 is made of the same silicone rubber as the separation roller 25. Separation roller 2
5 and the feed roller 26 are driven in the direction of the arrow in the figure by a drive source (not shown). Further, the gear 5 and the shaft 11 are directly connected by a pin, and a torque limiter 32 is built in between the gear 6 and the shaft 11 so that the reverse rotation roller 1 slides when a torque of a set value TR or more is applied. . 31 is a paper sheet.

Here, the feed roller 26, the pinch roller 2, the reverse rotation roller 1, the gears 3, 4, 5, 6, 7 and the shaft 8,
The drive transmission means T is constituted by 9, 10, and 11.

The frictional force between the rollers or between the rollers and the paper sheet is described as follows.

Between reverse rotation roller 1 and separation roller 25 ... Between F1 pinch roller 2 and feed roller 26 ... F2 Between reverse rotation roller 1 and sheet 31 ... F3 Between separation roller 25 and sheet 31 ... F4 Between two sheets 31 F5 Between pinch roller 2 and sheet 31 F6 Between feed roller 26 and sheet 31 F7 Then, the radii of the reverse roller 1 and the pinch roller 2 are r1 and r2, respectively, and from the pinch roller 2 to the reverse roller 1
If the speed reduction ratio up to is η, each value is set by the friction coefficient of each roller and the leaf springs 18a, 18b, 21a, 21b to be the number 1, so that the sheet is set on the lower original guide 29. In response, the automatic paper feeder operates as follows.

[0026]

[Formula 1] F1 · r1> TR (i) F3 · r1>TR> F5r1 (ii) F4> F5 (iii) ηF2 · r2> TR (iv) ηF6 · r2> TR (v) ηF7 R2> TR (vi) (1) In the case of no paper sheet (see FIG. 5) (i) and (iv), the reverse roller 1 and the pinch roller 2 rotate with the separation roller 25 and the feed roller 26, respectively. Then, the torque limiter 32 slips.

(2) When there is one sheet (see FIG. 6) (ii) (F3 · r1> TR), (v) and (vi), the reverse roller 1 and the pinch roller 2 are interleaved with the sheet 31. Then, the separation roller 25 and the feed roller 26 rotate together, and the torque limiter 32 slides (performs the same operation as (1)).

(3) When there are two or more sheets (see FIG. 7) (ii), (iii), (v), and (vi), the pinch roller 2 is moved to the feed roller 26 via the sheet. And the reverse rotation roller 1 reversely rotates and returns the paper sheets other than the lowest paper sheet upstream in the paper sheet conveyance direction.
The torque limiter 32 does not slip, but slips between the sheets.

In the present embodiment, the reverse roller 1, the pinch roller 2, the separation roller 25 and the feed roller 26 are made of the same silicone rubber, so that F1, F2, F
3, F4, F6, and F7 can be centrally managed, and it is easy to maintain the conditions (i) to (vi). If the rollers 1, 2, 25, and 26 are made of different materials, the frictional force of each roller may vary due to manufacturing variations, differences in the coefficient of friction with respect to various paper sheets, and changes over time. Conditions fluctuate and conditions (i) to (vi)
Will be difficult to maintain.

In this example, the lower original guide 29
The paper is set with an appropriate inclination so that the set paper sheet slides down to the separation roller by its own weight. Further, even curled paper sheets can be set by the guides 24a and 24b without the tip of the sheet being turned up.

As shown in FIG. 2, the upper document guide 17 has a fulcrum 3
3 is rotatably supported by a main body frame of a facsimile machine (not shown), and is held at a constant height with respect to the lower document guide by a locking means (not shown). When the locking means (not shown) is released, the upper original guide 1 as shown in FIG.
It is possible to lift 7. At this time, the reverse rotation roller unit composed of 1 to 16 is lifted together with the upper document guide 17. On the contrary, if the upper document guide 17 is lowered, the reverse rotation roller unit also descends, and the reverse rotation roller 1 and the pinch roller 2 are separated by the separation roller 2 again.
5. Contact with the feed roller 26 to form a reversible ADF. In this way, the release between the rollers is easily realized without using a complicated mechanism, so the failure rate and the manufacturing cost are low.

In this embodiment, the use of the torque limiter 32 eliminates the slippage between the reverse rotation roller 1 and the separation roller 25 or between the reverse rotation roller 1 and the sheet, so that the reverse rotation roller 1 and the separation roller 25 are worn. Very few, improving the durability of the device.

Further, since the side plates 12 and 13 are made of polyacetal and also serve as the bearings of the pinch roller 2, the cost is low and the assemblability is improved.

Further, since each roller is made of silicone rubber, the friction coefficient is less decreased even with respect to the silicone oil adhering to the copy paper, and the copy paper with the silicone oil adhered thereto can be stably fed. The effect is that you can do it.

Further, even sheets curled by the guides 24a and 24b are easy to set and the operability is improved. Although the torque limiter 32 is used in this embodiment, the torque limiter may be omitted. In this case, if the frictional force between the rollers or between the rollers and the paper sheet is set to the equation 2 by the friction coefficient of each roller and the leaf springs 18a, 18b, 21a, 21b, the automatic paper feeding device Works like.

[0036]

## EQU2 ## ηF2> F1 (vii) F4> F3 (viii) ηF7> F3 (ix) ηF6> F3 (x) F3> F5 (xi) (1) Without paper (FIG. 8) (Refer to (vii)) The reverse roller 1 and the separating roller 25 slip. If the feed roller 26 slips, the feed accuracy is deteriorated due to wear, which is not preferable.

(2) When there is one sheet (see FIG. 9) Due to (viii) to (x), the space between the reverse rotation roller 1 and the sheet slips.

(3) When there are two or more sheets (see FIG. 10) (viii) and (xi), the sheets other than the lowest sheet are returned upstream in the sheet conveying direction, and only the lowest sheet is conveyed. Are separated and sent by the feed roller 26.

In any of the above cases (1) to (3), the reverse rotation roller 1 always continues reverse rotation. Since the torque limiter does not need to be set and adjusted, it is a reversing type AD that is cheaper and has better assembly
It can be F.

Of the frictional force conditions of this embodiment, (v
To realize iii), F4 (separation roller 25 and sheet 31
The frictional force between them must be larger than F3 (the frictional force between the reverse rotation roller 1 and the sheet 31). Since the reverse roller 1 and the separation roller 25 are in pressure contact with each other with the paper sheet 31 sandwiched therebetween, the magnitude of the friction coefficient of both rollers directly becomes the magnitude of the frictional force. The friction coefficient must be larger than the friction coefficient between the reverse roller 1 and the paper sheet 31. In order to maintain this magnitude relationship stably, it is advisable to use the same type of rubber (for example, silicon) as the material of both rollers and change the hardness. Generally, rubber has a higher coefficient of friction when it has a lower hardness, and therefore the separating roller 25 should be made softer.

The side plates 12 and 13 may be integrated. Further, the material may be steel plate. As a result, it is possible to improve the accuracy of parts, prevent the reverse rotation roller 1 and the pinch roller 2 from deviating from the biased pressure, and improve the reliability of the reverse rotation ADF.

Further, the leaf springs 18a, 18b or 21
It is also possible to delete one set or both sets of a and 21b and press each roller by the weight of the reverse rotation roller unit.
If the reverse roller unit is fixed to the upper document guide and the upper document guide is in a rotatable state without locking, the upper document guide can be used with its own weight adjusted. Since the load by the use of its own weight is less likely to vary than the load by the spring member, stable separation performance can be obtained.

Further, the reverse roller unit may be set to the lower side, the separation roller 25 and the feed roller 26 may be set to the upper side, and an automatic sheet feeding device for feeding from the uppermost position may be used. Since the reverse rotation roller unit according to the present invention is a unit independent of the drive system of the feed roller 26, there is an effect that the layout of the apparatus can be freely set.

Further, in this embodiment, the gear train is used as the drive transmission means from the pinch roller 2 to the reverse rotation roller 1, but a toothed belt or a flat belt can also be used.

Further, the reverse roller 1, the pinch roller 2, the feed roller 26, and the separation roller 25 can be made to be a common component not only in material but also in shape. Parts management becomes easy and manufacturing cost can be kept low.

Also, all rollers are made of the same material,
The effect of the present invention can also be obtained by using three to three rollers of the same material.

[0047]

As described above, by combining the drive transmission means from the pinch roller to the reverse rotation roller in an independent unit, the drive force is transmitted from the feed roller by the frictional force between the pinch roller and the feed roller. Even if there is no drive source on both the reverse rotation roller side and the separation roller / feed roller side, or even if there is no complicated drive connection / disconnection mechanism to combine the drive sources into one, the reverse rotation roller is easily By releasing the space between the separation roller and the feed roller, it is possible to clear the jam of the document and maintain the ADF.

As described above, since only one drive source is required, the manufacturing cost of the device can be suppressed, or a complicated mechanism can be dispensed with, so that there is an effect that the device can be made inexpensive and less prone to failure. Further, since the reverse rotation rollers are independent, the degree of freedom in the device layout is improved, and the design is facilitated.

Further, by forming at least two of the separation roller, the reverse rotation roller, the feed roller and the pinch roller from the same material, even if there is a manufacturing variation or a change over time in the material, each roller is formed. Similarly, the frictional force fluctuates and the separation / unwinding performance does not deteriorate.
Therefore, there is no need for a roller selecting step and a roller pressing force adjusting step, which has an effect of reducing the manufacturing cost.

When the torque limiter is provided, the slippage between the reverse rotation roller and the separation roller or between the reverse rotation roller and the sheet is eliminated, so that the reverse rotation roller and the separation roller wear very little and the device The durability is improved.

[Brief description of drawings]

FIG. 1 is a plan view of an automatic paper feeder according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a view on arrow B of FIG.

FIG. 4 is a view showing a state where an upper original guide of the apparatus is lifted.

FIG. 5 is an operation explanatory diagram of the same apparatus.

FIG. 6 is an operation explanatory diagram of the same apparatus.

FIG. 7 is an operation explanatory diagram of the same apparatus.

FIG. 8 is an operation explanatory view in the case where the torque limiter is not used in the device.

FIG. 9 is an explanatory diagram of an operation when the torque limiter is not used in the device.

FIG. 10 is an operation explanatory view in the case where the torque limiter is not used in the device.

FIG. 11 is a cross-sectional perspective view of the automatic sheet feeder, showing only the upper document guide side.

FIG. 12 is a configuration diagram of a conventional automatic paper feeder.

[Explanation of symbols]

1 Reverse roller 2 pinch rollers 25 Separation roller 26 Feed roller 31 paper leaf 32 Torque limiter T drive transmission means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03G 15/00 109 7369-2H H04N 1/00 108 L 4226-5C

Claims (5)

[Claims] 1. A separation roller for feeding a paper sheet, a reverse roller that contacts the separation roller and rotates in a direction opposite to the paper feeding direction, and a separation roller downstream of the separation roller in the paper feeding direction. A feed roller that rotates in the same direction,
An automatic paper feeding device having a pinch roller that comes into contact with the feed roller and rotates together with the feed roller, characterized by comprising drive transmission means for transmitting power from the pinch roller to the reverse rotation roller. Paper equipment. 2. The automatic paper feeder according to claim 1, wherein at least two or more of the separation roller, the reverse roller, the feed roller, and the pinch roller are made of the same material. 3. The automatic paper feeder according to claim 2, wherein the separation roller, the reverse rotation roller, the feed roller and the pinch roller are made of the same material and have the same shape. 4. The automatic paper feeder according to claim 1, wherein at least two or more of the separation roller, the reverse roller, the feed roller, and the pinch roller are made of rubbers of the same type but different in hardness. 5. The automatic sheet feeder according to claim 1, 2, 3 or 4, wherein a torque limiter is provided in the drive transmission means.