JPH0248974A - Automatic paper-feeding mechanism - Google Patents

Abstract

PURPOSE:To secure a high feeding accuracy by removing a force for pressing a separating roller and a friction pad against each other when a paper is clamped between feeding rollers on the immediate downstream side of the separating roller. CONSTITUTION:With a separating roller 3 rotated, a pick-up roller 2 is rotated to feed a paper 1 between the roller 3 and a friction pad 4. A feeding roller 7 feeds the paper 1 by clamping the paper 1 between it and a pressure roller 8. When the leading end of the paper is detected by a photo-sensor 11, solenoids 10a, 10b are turned ON, the pick-up roller 2 is tilted up, and the pad 4 is separated from the separating roller 3, resulting in that there is no load on trailing end parts of the papers 1 located in a hopper 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic paper feeding mechanism, and particularly to a small image OC.
The present invention relates to an automatic paper feeding mechanism suitable for devices that require high conveyance accuracy, such as R devices.

[Conventional technology]

Conventionally, a friction separation method has been used as a paper separation method for automatic paper feeding mechanisms for printers because the applicable paper thickness of separation paper is large. This method is published in Japanese Patent Application Laid-Open No. 62-216774.
As described in Japanese Patent Publication No. 58-28395, even if a friction pad is brought into pressure contact with a separation roller and a plurality of sheets are inserted between the separation roller and the friction pad (frictional force between separation roller sheets) Only the paper that comes into contact with the separation roller is fed due to the relationship of (paper-paper friction force), (friction pad-paper friction force)>(paper-paper friction force).

[Problem to be solved by the invention]

The above-mentioned separation method usually has a one-way clutch built into the 9-separation roller, and when the paper is sandwiched between the conveyance rollers of the main unit after separating the paper, the driving force of the separation roller is cut off, the paper is fed by the conveyance roller, and then the separation roller The paper is rotated idly while conveying the paper, thereby reducing the conveyance load.

However, when the above method is applied to a device such as image OCR that requires high conveyance accuracy, the load on the separation roller becomes a problem. Due to the load on the separation roller, the conveyance speed slows down only when the paper is on the separation roller, making it impossible to obtain sufficient reading accuracy.

As a solution to this problem, measures such as increasing the pressing force of the pressure roller, using rubber rollers with a high friction coefficient, and adding a conveyance roller between the separation roller and the conveyance roller are available in order to increase the conveyance force of the conveyance roller of the main unit. Conceivable. However, an increase in the pressing force of the pressure roller results in an increase in the driving force of the conveyor roller, which necessitates the use of a large, high-output motor, leading to an increase in the size of the device. Further, since the paper conveyed by OCR is written with a pencil, ballpoint pen, etc., the increase in the pressing force of the pressure roller causes the paper to become smeared due to roller transfer, which becomes a serious problem.

Rubber with a high coefficient of friction generally requires a lot of roller transfer, which poses a problem in its use. Adding conveyance rollers secures mounting space,
There is a problem in that the increased size of the motor due to the increased driving force leads to an increased size of the device.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic paper feeding mechanism that can solve these conventional problems, ensure high conveyance accuracy with a simple configuration, and reduce costs.

[Means to solve the problem]

In order to achieve the above object, the automatic paper feeding mechanism of the present invention uses a pickup roller and a separation roller to feed paper between the separation roller and a friction pad that presses against the separation roller, separates the paper one by one, and separates the paper one by one into the main body. In an automatic paper feeding mechanism that feeds paper to the apparatus, means is provided for releasing the pressure contact between the separation roller and the friction pad, and when the paper that has been fed for one minute is pinched by the conveyance roller immediately after the separation roller,
A feature of the present invention is that the pressing force between the separation roller and the friction pad is released.

The releasing means includes a sensor that detects that the paper is held between the first conveying rollers.

A solenoid or the like is provided to pull the friction pad away from the separation roller. In addition, as another means of release, the 5-separation roller is shaped with a part of its circumference cut out, and when the notch of the separation roller and the friction pad face each other, there is a mechanism that prevents the separation roller and the friction pad from coming into contact with each other. do.

[Effect]

In the present invention, when the paper separated and fed by the separation roller and the friction pad is nipped by the first conveyance roller, the pressure contact between the separation roller and the friction pad is released.

That is, in the above-mentioned releasing means, when it is detected that the paper has been separated and conveyed and is nipped by the first conveyance roller, the solenoid is turned on to pull the friction pad away from the separation roller. This eliminates the load caused by the one-separation roller, so even if only the first conveyance roller is used, the conveyance speed does not decrease and high-precision conveyance is possible.

In another release means, a part of the separation roller is cut out so that when the paper is separated and conveyed by the separation roller and is nipped by the first conveyance roller, the cutout part of the separation roller faces the friction pad. By doing this, a gap is created between the 1-separation roller and the friction pad, and the load caused by the separation roller is eliminated. As a result, the paper can be transported with high precision even by using only the first transport roller.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional structural view of an automatic paper feeding mechanism showing an embodiment of the present invention. This shows an example in which the present automatic paper feeding mechanism is applied to a small-sized image OCR device.

Paper sheets 1 are stacked and set in a hopper 12, and a pickup roller 2 is in contact with the paper sheets 1. A driving force is transmitted to the pickup roller 2 by the separation roller 3 and a gear train 13, and the pickup roller 2 is rotatable about the shaft of the separation roller 3 by a bracket 14. bracket]
4 is lifted upward by turning on the solenoid 10a. A friction pad 4 is pressed against the separation roller 3 by a spring 5, and when the solenoid 10b is turned on, the friction pad 4 is pulled around the rotating shaft 6, and the pressure of the friction pad 4 can be released. The separation roller 3 is rotationally driven by a motor (not shown).

When feeding the paper 1, a motor (not shown) rotates the separation roller 3, a gear train 13 rotates the pickup roller 2, and the topmost paper of the stacked papers 1 is transferred between the separation roller 3 and the friction pad. Transported between 4 and 4. At this time, even if a plurality of sheets of paper are conveyed, only the paper that is in contact with the separation roller 3 is separated and conveyed to the conveyance roller 7 due to the pressing force between the separation roller 3 and the friction pad 4 . The conveyance roller 7 is driven by a motor (not shown), and holds the conveyed paper 1 between it and the pressure roller 8.

transport. When the photo sensor IJ detects the leading edge of the paper 1, the solenoids 10a and 10b are turned on.

The hopper 12 is lifted by lifting the pickup roller 2 and pulling the friction pad 4 away from the separation roller 3.
No load is applied to the trailing edge of the fed paper 1 at the position. Paper 1 is transported by conveyance roller 7 and pressure roller 8.
is conveyed, and the information on the paper 1 is read by the image sensor 9.

In this way, in this embodiment, when the image sensor 9 performs reading, there is no load on the separating section, so there is no fluctuation in the conveyance speed, and high reading performance is obtained.

FIG. 2 is a side sectional structural view of an automatic paper feeding mechanism showing another embodiment of the present invention. This also shows an example in which the two-line automatic paper feeding mechanism is applied to a small image OCR device, as in FIG. 1.

The pickup roller 2 and the separation roller 3 have a shape with a part of the circumference cut out, and are rotated by rotationally driving the separation roller 3 by a motor (not shown) via a gear train 13. The friction pad 4 is pressed against the separation roller 3 by a spring 5, and there is a gap when the friction pad 4 faces the notch of the separation roller 3. The pickup roller 2 also has a gap when the paper 1 and the notch face each other. In other embodiments, the solenoid 10a of the embodiment of FIG.
, 10b, the bracket 14 and the photo sensor 8 are not provided, but the pickup roller 2 and the separation roller have different shapes.

FIGS. 3(a) to 3(C) are diagrams for explaining the separation operation in FIG. 2.

In the initial state, as shown in FIG. 3(a), the cutout of the pickup roller 2 faces the paper 1, and the cutout of the separation roller 3 faces the friction pad 4. Pick up roller 2 and separation roller 3 in the direction of arrow A
When the pickup roller 2 is rotated in the direction, the circumferential portion of the pickup roller 2 comes into contact with the paper 1 and conveys the paper 1 between the separation roller 3 and the friction pad 4 (FIG. 3(b)). By setting the length L of the circumferential portion of the separation roller 3 and the pickup roller 2 to be slightly longer than the distance Q between the leading edge of the paper in the hopper 12 and the transport roller 7, when the separation roller 3 rotates once, the paper 1 The leading edge of the sheet l is held between the conveyance roller 7 and the pressure roller 8, and the cutout portions of the separation roller 3 and pickup roller 2 are at the initial position and do not apply any load to the sheet l, as shown in FIG. 3(C). The drive of the separation roller 3 is turned off, and the paper 1 is transported only by the transport roller rough.

In this way, in this embodiment and other embodiments, when the separated and conveyed paper is read by the image sensor,
Since the load on the separating section can be eliminated, fluctuations in conveyance speed can be eliminated, and an automatic paper feeding mechanism for a compact image OCR device with high reading performance can be realized.

Further, in the above embodiment, the automatic paper feeding mechanism is applied to a small-sized image OCR device, but it can be similarly applied to image printers, image scanners, etc. that require high conveyance accuracy.

〔Effect of the invention〕

As described above, according to the present invention, high conveyance accuracy can be ensured with a simple configuration, so that the cost of the apparatus can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a side sectional structural view of an automatic paper feeding mechanism showing one embodiment of the present invention, FIG. 2 is a side sectional structural diagram of an automatic paper feeding mechanism showing another embodiment of the invention, and FIG. FIG. 2 is an explanatory diagram of the operation of FIG. 2; 1: paper, 2: pickup roller, 3: separation roller,
4: Friction pad, 5: Spring, 6: Rotating shaft, 7:
Conveyance roller, 8: Pressure roller. 9: Image sensor, 10a, 10b: Solenoid sensor 1
1: Photo sensor, 12: hopper, 13: gear train, 14 nib bracket.

Claims (1)

[Claims] 1. In an automatic paper feeding mechanism in which a pickup roller and a separation roller feed paper between the separation roller and a friction pad that is in pressure contact with the separation roller, the paper is separated one by one, and the paper is fed to the main unit. A means for releasing the pressing force between the roller and the friction pad is provided, and the pressing force between the separating roller and the friction pad is released when the separated and fed paper is pinched by a conveying roller immediately after the separating roller. automatic paper feeding mechanism.