JPH03200632A - Method and device for feeding sheet for lamination - Google Patents

Abstract

PURPOSE:To always maintain a contact pressure between a feed roller and a sheet in a proper range by energizing sheets laminated in a placing plate from below through the force of a resilient member, and variably displacing a compression displacing amount of the resilient member according to a detecting signal by means of which the size of a sheet is detected. CONSTITUTION:A placing plate 12 for sheets fed one by one by means of a feed roller 16 is rockable around an axle 11 and energized to the feed roller 16 side through the force of a compression spring 15. A compression displacing amount of the compression spring 15 is displaced by a displacing means 20. Based on moving displacement of a regulating guide 14 for the length of a sheet, a sheet size is detected by a detecting means 30. The detecting signal is decided by a sheet size detecting circuit 33, and a deciding signal is inputted to a controller 34. The number of pluses responding to a sheet size is transmitted to a motor driver 26 to run a stepping motor 25 by a given amount, and the compression spring 15 is compressed and displaced according to a sheet size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a paper feeding unit incorporated in an automatic paper feeding device such as an auto feeder, and a paper feeding unit incorporated in various printing devices such as a page printer, a copying machine, and a facsimile machine. Regarding paper feeding methods and devices applied as a The present invention relates to a paper feeding method and apparatus in which the feeding pressure applied to the paper feeding roller can be appropriately adjusted.

“Prior Art” Conventionally, in automatic paper feeding devices such as auto feeders, and various printing devices such as page printers, copiers, and facsimiles, multiple sheets of originals or recording media (hereinafter referred to as A paper feeding device is incorporated to feed sheets of paper (referred to as paper) to the main body of the apparatus one by one.

This type of device generally includes a paper feed roller disposed above the front side of a loading plate, a loading plate configured such that at least the front side can swing freely in the direction of contacting and separating from the paper feeding roller, and an urging force from below the loading plate. By rotating the paper feed roller with the paper stack layer arranged on the placement plate pressed against the paper feed roller side by the elastic member, the paper is delivered one sheet at a time to the main body of the apparatus. It is something that can be supplied.

However, in such a paper feeding mechanism, if the contact pressure between the paper feed roller and the paper exceeds a predetermined pressure, double feeding will occur, and if the contact pressure falls below a predetermined pressure, the paper feed roller will slip, making it impossible to feed the paper smoothly. Therefore, the spring constant of the elastic member is selected so that the contact pressure is maintained within an appropriate range for the specified paper.

That is, since each of the elastic members has a spring constant set corresponding to the weight per unit thickness of the specified paper, when paper having different weight per unit thickness, for example, paper of different size, is used, The contact pressure exceeds the appropriate range,
Smooth feeding becomes difficult.

For this reason, in known paper feeding devices, a dedicated paper feeding section is prepared for each paper size, and a plurality of these paper feeding sections are attached, or/and the paper feeding section is made into a cassette, and the cassette is is configured to be detachable.

``Technical Problems to be Solved by the Invention'' However, providing a plurality of paper feed sections leads to an increase in the size of the device, and making the cassette detachable leads to a complicated configuration.

In order to eliminate this drawback, various feeding devices have been developed that can always maintain the contact pressure within an appropriate range even when sheets of different sizes are stacked on the paper feeding section, thereby enabling smooth feeding. Proposed.

For example, in Japanese Patent Publication No. 62-21690, multiple underlays with different weights are prepared, each set to an appropriate weight corresponding to the thickness-to-weight ratio of each paper size, and the underlayment corresponding to the paper to be fed is placed in advance. A paper feeding device has been proposed in which the spring pressure is corrected by placing the contact pressure on a plate so that the contact pressure can always be maintained within an appropriate range.

However, in this conventional technique, the underlay must be replaced every time sheets of different sizes are fed, which not only makes the replacement work complicated.

As the paper size increases, the number of underlays that must be prepared increases, which not only requires storage space but also increases the risk of replacing the wrong underlay.

For this reason, in conventionally known paper feeding devices, the paper feeding port is thinned to limit the amount of stacked paper that can be fed, and as a result, the contact pressure of different paper sizes is maintained within an appropriate range.

In view of the shortcomings of the prior art, the present invention automatically changes the spring pressure according to the paper size without preparing an underlay, etc., and always maintains the contact pressure between the paper feed roller and the paper within an appropriate range. The purpose of the present invention is to provide a paper feeding device configured to enable

"Technical Means for Solving the Problem" The present invention provides variable compression displacement of an elastic member biased from below the stacking plate on which paper is stacked based on a detection signal that detects the size of the stacked paper. The present invention is characterized in that a predetermined contact pressure between the uppermost sheet of paper and the feeding means is maintained within an appropriate range. Note that the paper size may also be displayed based on the detection signal.

Such a paper feeding device is provided with a detection means for detecting the size of the stacked sheets, and a displacement means for displacing the amount of compressive displacement of the elastic member, and the displacement means is controlled based on a signal from the detection means. It is sufficient if the configuration is operable.

The paper size detection may generally be configured to be detected based on the displacement of a paper width regulation guide provided on the paper feed tray. This makes it impossible to detect the paper size only in one width direction.

For this reason, it is preferable to detect the paper size based on the displacement of a paper length detection guide that is movable in the longitudinal direction of the paper.

In this case, the displacement of the paper itself may be directly detected, but the paper is not necessarily white; transparent or black may be used; This is not preferable because accurate detection may be difficult due to dirt or the like, especially when an optical sensor is used.

Note that the feeding means does not necessarily refer only to feeding rollers, but also includes feeding belts and the like.

"Embodiments" Hereinafter, embodiments of the present invention will be described in detail by way of example based on the drawings. However, unless otherwise specified, the dimensions, materials, shapes, and relative positions of the components described in the second embodiment are merely illustrative examples and are not intended to limit the scope of the present invention. It's nothing more than that.

The drawing is a basic configuration diagram of a paper feeding device according to an embodiment of the present invention.
As is well known, there is a mounting plate 12 which is configured to be swingable in the direction toward and away from the paper feed roller about an axis 1, a width regulating guide 13 movable in the paper width direction and the longitudinal direction, and It includes a paper feed section main body 10 that integrally accommodates a width regulation guide 14 and a compression spring 15 biased from below the placement plate 12, and a paper feed roller 16 is provided above the front side of the placement plate 12. It is arranged.

The present embodiment particularly includes a detection means 30 for detecting the paper size based on the displacement of the length regulation guide 14;
Displacement means 2 for displacing the amount of compression displacement of the compression spring 15
0 is set.

The displacement means 20 includes a piston 21 disposed at the bottom of the compression spring 15, a fixing base 22 for directing the piston 21 to move up and down, a worm shaft 23 hanging downward from the bottom surface of the piston 2, and a worm shaft 23 that hangs downward from the bottom of the piston 2. It consists of a worm 24 that meshes with a shaft 23, a stepping motor 25 that applies rotational force to the worm 24, and a motor driver 26 thereof.

On the other hand, the detection means 30 includes a reflective tape 31 attached to the bottom surface of the regulation guide 14, and a plurality of reflective photosensors 32a arranged at positions corresponding to the longitudinal end of each standard paper stacked on the placement plate 12. The paper size detection circuit 33 determines which size of paper the regulation guide 14 is regulating the length of based on the signal from the sensor, and the determination signal is sent via the controller 34. The output signal is output to the display driver 35, and the display driver 35 lights up a display section in the display 36 that indicates the paper size corresponding to the determination signal.

Further, the controller 34 receives the determination signal and determines a
In order to obtain a contact pressure with the paper feed roller 16 corresponding to the paper size stacked on the placement plate 12, a pulse signal is sent to the motor driver 26 to rotate the stepping motor 25 by a predetermined amount.

That is, when the controller 34 receives the determination signal, the controller 34 sends the number of pulses corresponding to the corresponding paper size to the motor driver 26 to rotate the stepping motor 25 by a predetermined amount.

The rotation of the motor 25 causes the piston 2I to move up and down by a predetermined amount via the worm/worm shaft 23, and the compression spring 15 is set to a compression displacement amount corresponding to the paper size.

Reference numeral 27 denotes a home position detection sensor attached to the fixed base 22, which moves the piston 21 to the home position when the power is turned on or when a paper size detection error occurs, and causes the controller to move the piston 21 to a predetermined reference position. This is to make people aware of the fact that

According to this embodiment, the paper size can be detected reliably, and the contact pressure with the paper feed roller 16 can be appropriately controlled in accordance with the paper size by simple control using a stepping motor, thereby ensuring reliable paper feeding. can be done.

"Effects" As described above, according to the present invention, the contact pressure between the paper feed roller and the paper feed roller can always be maintained within an appropriate range by simply detecting the paper size of the paper placed on the placement plate. Moreover, since the size detection can be easily carried out using the paper regulation guide in the longitudinal direction, it does not cause any burden on the user.

In addition, since the adjustment of the contact pressure simply changes the amount of compressive displacement of the elastic member, it can be achieved with a simple configuration and without malfunction even if the paper size increases, which is extremely advantageous in practical terms. .

It has various effects such as

[Brief explanation of drawings]

The drawing is a basic configuration diagram showing a paper feeding device according to an embodiment of the present invention.

Claims (1)

[Claims] 1) A paper feeding method in which paper is fed while maintaining a predetermined contact pressure between the uppermost paper and the feeding means by the spring pressure of an elastic member biased from below the stacked paper. , the compression displacement amount of the elastic member is variably displaced based on a detection signal for detecting the size of the stacked sheets, and the contact pressure with the feeding means is maintained within a predetermined range. Paper feeding method 2) In a paper feeding device that feeds paper while maintaining a predetermined contact pressure between the uppermost paper and the feeding means by the spring pressure of an elastic member biased from below the stacked paper, A feeder comprising: a detection means for detecting paper size; and a displacement means for displacing the compressive displacement amount of the elastic member, and the displacement means is configured to be operable based on a signal from the detection means. Paper device 3) The paper feeding method according to claim 1, wherein the paper size detection is performed by a paper guide movable in the longitudinal direction of the paper, which also serves as a paper length detection means, and by displacement of the paper guide.