JP2001233473A - Paper feeding device, recording device, and paper feeding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control paper feeding action by a simple mechansim. SOLUTION: On a control shaft 5, a hopper cam 21, driven roller units 40, 41, a separation pad unit 30, and sheet returning units 50, 50 are provided. As the control shaft 5 makes one round of rotation, an abutment position and a separated position of a hopper 2 are displaced by the hopper cam 21, an abutment position and a separated position of a paper feeding follower roller 4 are displaced by the follower roller units 40, 41, an abutment position and a separated position of a separation pad 11a are displaced by the separation pad unit 30, and paper returning operation is conducted by the paper returning units 50, 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet feeding device for feeding a recording material in a recording device and a recording device provided with the sheet feeding device. Further, the present invention relates to a paper feeding method.

[0002]

2. Description of the Related Art One of recording devices is a printer.
Some printers take out the uppermost printing paper from a paper feeding (paper) tray on which a plurality of stacked printing papers (cut sheets) are placed and feed it to a recording unit (printing unit).

[0003] In such a printer, a hopper arranged at a lower portion of a paper feed tray lifts the printing paper upward, abuts (presses) the paper on a paper feed roller, and then rotates the paper feed roller. The upper printing paper is taken out,
A paper feeding operation of feeding paper to the printing unit is performed.

In this paper feeding operation, a separation pad is provided to prevent the next or subsequent printing paper from being fed together with the uppermost printing paper (ie, double feeding) by the paper feeding roller. The separation pad is disposed near the downstream side of the location where the printing paper is pressed against the paper feed roller by the hopper, facing the paper feed roller surface. During the paper feeding operation, the separation pad is arranged at a contact position where it comes into contact with (presses against) the paper feed roller, thereby pressing the printing paper between the paper feed roller and the difference in friction coefficient. Then, the top printing paper is separated from the next printing paper. On the other hand, when printing is started in the printing section, the separation pad is moved to a separated position away from the sheet feeding roller in order to reduce the transport load (also referred to as “transport resistance” or “back tension”) in the printing section. Be placed.

Prior to the start of the paper feeding operation, a paper return lever is disposed to return the printing paper present on the separation pad to the paper feeding tray. Before the sheet feeding is started, the sheet is temporarily returned to the sheet feeding tray side.

Conventionally, the operations of the hopper, the separation pad, and the sheet return lever have been controlled by a plurality of devices or mechanisms. For example, a plurality of drive motors are provided, and each drive motor is individually controlled.
At least one control mechanism is individually controlled by a plurality of control mechanisms controlled by the drive motor.

[0007]

Therefore, in the conventional printer, the printer mechanism becomes complicated, the number of parts increases,
This has led to problems such as an increase in the size and cost of the printer. On the other hand, in recent years, there has been an increasing need for a printer that is smaller and lighter and lower in price, and it is desired that the printer can be controlled with as few components as possible and with a simple mechanism.

The present invention has been made in view of such a situation, and an object of the present invention is to enable control of a sheet feeding operation by a simple mechanism.

[0009]

According to a first aspect of the present invention, there is provided a sheet feeding apparatus capable of normal rotation and reverse rotation, and having a recording unit for performing recording on a recording material by performing normal rotation. A paper feed roller for feeding a recording material, a recording material storage section on which the recording material is placed, and a contact position for bringing the recording material placed in the recording material storage section into contact with the paper feed roller; A recording material contacting means capable of disposing the recording material storage portion at a separation position separated from the paper feed roller; and a contact position contacting the paper supply roller and separating from the paper supply roller. Separating means for separating the uppermost one of the recording materials placed in the recording material storage part from the latter one, by the paper feed roller; And a contact position where it comes into contact with the paper feed roller and a distance from the paper feed roller. The paper feed driven roller, which is driven and rotated by the rotation of the paper feed roller by contacting the paper feed roller, and the recording material on the separation means are brought into contact with the paper feed roller. A return position for returning to the recording material storage portion and another standby position can be set, and the recording material on the separation means is displaced from the standby position to the return position so that the recording material on the recording material storage portion can be set. And a recording material returning means for feeding the recording material in the recording apparatus, wherein the recording material contact means is switched between a contact position and a separation position. (1) switching means, second switching means for switching between the contact position and separation position of the separation means, third switching means for switching between the contact position and separation position of the paper feed driven roller, and Return position of recording material return means A fourth switching means for switching between a standby position, further wherein the first switching means, said second switching means, said third switching means and said fourth switching means,
It is attached to one control shaft, and the position is switched by each of these switching means by one rotation of the control shaft.

According to the invention described in claim 1 of the present application, the first
Switching means, the second switching means, the third switching means, and the fourth switching means are mounted on one control shaft, and when the control shaft makes one rotation, the position is switched by these switching means. Are performed respectively. Therefore, the control mechanism of these switching means can be simplified, and can be performed by one control axis, so that the number of parts can be reduced. The price can be reduced.

According to a second aspect of the present invention, in the first aspect, the control shaft is configured to determine a rotation reference before feeding the recording material from the recording material storage unit. After the rotation starts from the rotation reference position, the fourth switching means switches the recording material return means from the standby position to the return position, and then switches from the return position to the standby position again. Second switching means switches the separating means from the separated position to the contact position, and subsequently, the third switching means switches the paper feed driven roller from the separated position to the contact position, and subsequently or simultaneously, The first switching means is configured to switch the recording material contact means from the separated position to the contact position.

According to the second aspect of the present invention, before the recording material is fed from the recording material storage section, the rotation is started from a rotation reference position serving as a rotation reference, and the fourth rotation is started. The switching means switches the recording material return means from the standby position to the return position and then switches from the return position to the standby position again.
The recording material is returned to the recording material storage section before feeding. Thus, the sheet feeding operation to be performed can be appropriately performed. In particular, if the next recording material separated by the separation means is left in the separation means and the next feeding is performed, the recording material may not be properly fed. By returning the remaining recording material after the next rank,
Such a situation can be avoided. Further, since the returning operation is performed before the separating means is switched to the contact position, the returning operation is not hindered by the separating means.

Further, before the recording material is fed from the recording material storage section, the recording material returning means performs a returning operation, and the separating means is displaced to the contact position. Is prevented. In addition, by displacing the paper feed driven roller to the contact position, it is possible to obtain a conveyance force (feeding force) for the next feeding.

According to a third aspect of the present invention, in the paper feeding apparatus according to the second aspect, after the first switching unit switches the recording material contact unit from the separated position to the contact position, the first switching unit switches the recording material contact unit from the separated position to the contact position. The paper feed roller is configured to rotate forward. According to the third aspect of the present invention, the recording material is taken out of the recording material storage portion by the normal rotation of the paper feeding roller, and the taken out recording material is supplied to the recording portion by the feeding roller. Sent. In addition, this paper feeding operation is appropriately performed. That is, it is possible to reliably and quickly perform the recording material by feeding in which double feeding is prevented and a conveying force is obtained.

According to a fourth aspect of the present invention, in the paper feeder according to the second or third aspect, the second switching unit switches the third unit from the separated position to the contact position after switching the third unit to the third position. Before the switching means switches the paper feed driven roller from the separation position to the contact position, the paper feed roller is configured to reversely rotate.

According to the fourth aspect of the present invention, the sheet feeding roller reversely rotates after the separating means is switched to the contact position. As a result, the recording material that cannot be returned by the recording material return means can be reliably returned to the position where the recording material can be returned by the recording material storage section or the recording material return means, and double feeding can be prevented. it can.

According to a fifth aspect of the present invention, in the paper feeding apparatus according to the fourth aspect, the control shaft is configured to reversely return to the rotation reference position after the reverse rotation of the paper supply roller. Is characterized. According to the invention as set forth in claim 5 of the present application, after the paper feed roller is rotated in the reverse direction, the control shaft is rotated in the reverse direction to return to the rotation reference position, so that the returning operation by the recording material returning means is performed again. Thereby, the recording material returned to the position where the recording material return means can be returned by the reverse rotation of the sheet feeding roller can be returned to the recording material storage section, and double feeding is prevented.

According to a sixth aspect of the present invention, in the paper feeder according to any one of the third to fifth aspects, the paper feed roller rotates forward and the uppermost recording material is fed. Thereafter, the control shaft rotates, and the first switching means switches the recording material contact means from the contact position to the separated position,
Subsequently, the third switching means switches the paper feed driven roller from the contact position to the separated position.
Is configured to switch the separating means from the contact position to the separated position.

According to the sixth aspect of the present invention, after the uppermost recording material is fed, the first switching means switches the recording material contact means from the contact position to the separated position. Thereafter, even if the paper feed roller rotates forward, the recording material stored in the recording material storage unit is prevented from being fed by the paper feed roller. Further, since the third switching means switches the paper feed driven roller from the contact position to the separated position, the conveyance resistance (back tension) in the recording unit can be reduced in the subsequent recording in the recording unit. . This improves the transport accuracy in the recording section,
This leads to improved recording quality. Further, since the second switching means switches the separating means from the contact position to the separated position, back tension caused by the separating means being at the contact position can be eliminated.

According to a seventh aspect of the present invention, in the sheet feeding apparatus according to the sixth aspect, after the second switching unit switches the separation unit from the contact position to the separated position, the sheet supply roller is switched to the separated position. It is configured to rotate forward. According to the invention described in claim 7 of the present application, the second
When the recording unit performs recording after the switching unit switches the separation unit from the contact position to the separation position, the paper feed roller also rotates forward, so that the back tension generated by the paper feed roller is rotated by the forward rotation. Can be reduced.

According to an eighth aspect of the present invention, there is provided a recording apparatus including the sheet feeding device according to any one of the first to seventh aspects. According to the invention as set forth in claim 8 of the present application, it is possible to obtain the same effect as the above-described invention as set forth in any one of claims 1 to 7 in the recording apparatus.

In the paper feeding method according to the ninth aspect of the present invention, the recording material is fed to a recording unit which records on the recording material by rotating forward and reverse. A paper feed roller, a recording material storage unit on which the recording material is placed,
The recording material storage unit can be arranged at a contact position where the recording material placed in the recording material storage unit contacts the paper feed roller and a separation position where the recording material is separated from the paper supply roller. The recording material contact means can have a contact position where the recording material is in contact with the paper feed roller and a separation position where the recording material is separated from the paper supply roller. Separation means for separating the uppermost one of the recording materials from the next and subsequent ones, and a contact position for contacting the paper feed roller and a separation position for separating from the paper supply roller. The recording material on the separating means is stored in the recording material storage section by rotating the paper feeding driven roller which is driven and rotated by the rotation of the paper feeding roller by contacting the paper feeding roller. Return position to return, and other standby position A recording material return means for returning the recording material on the separating means to the recording material storage unit by displacing the recording material from the standby position to the return position. A method for feeding a recording material, wherein the recording material return means is switched from a standby position to a return position by a fourth switching means attached to the control shaft when the control shaft rotates, and then again. The separation means is switched from the return position to the abutment position by the second switching means attached to the control shaft, and then to the third position attached to the control shaft. The feeding driven roller is switched from the separated position to the contact position by switching means, and subsequently or simultaneously, the recording material contact roller is contacted by the first switching means attached to the control shaft. Switching the stage from the separation position to the contact position, is then rotating the paper feed roller, it is characterized. According to the ninth aspect of the invention, it is possible to obtain the same operation and effect as those of the first to third aspects of the invention.

According to a tenth aspect of the present invention, in the ninth aspect, the control shaft is rotated after the paper feed roller rotates forward and the uppermost recording material is fed. The recording medium contact means is switched from the contact position to the separation position by the first switching means, and then the paper feed driven roller is separated from the contact position by the third switching means. And switching the separation means from the contact position to the separation position by the second switching means, and then rotating the paper feed roller. According to the tenth aspect of the present invention, it is possible to obtain the same operation and effect as those of the above-described sixth and seventh aspects of the present invention.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Overview of Ink Jet Printer] In the following, referring mainly to FIG. 1 and appropriately referring to FIG. 2 and FIG. 3, a "recording apparatus" according to the present invention will be described. An outline of the ink jet printer will be described. FIG. 1 is a schematic side view of an ink jet printer 100. FIG. 2 is a plan view (top view) of the ink jet printer 100, and mainly shows a hopper, a hopper holder, a control shaft 5, and a paper feed roller 3. FIG. 3 is a plan view (top view) showing the control shaft 5.
It is.

An ink jet printer (hereinafter, simply referred to as “printer”) 100 is a printing paper (cut sheet, hereinafter, simply referred to as “paper”) P as a “recording material”.
Has a substantially U-shaped feed path in side view.
At the start end of the feeding path, a sheet feeding tray 1 as a “recording material storage section” is provided, and on the feeding path, a sheet feeding roller 3 and a conveying roller (paper feeding roller) 6 are provided. ing. A carriage 8 is provided downstream of the transport roller 6.
And a paper discharge roller 7.

The paper feed tray 1 holds a plurality of stacked sheets P
And is detachably attached to the printer 100 with the paper P stored. Installation is
This is performed by being inserted almost horizontally from the near side of the printer 100 (left side in FIG. 1) to the back of the printer 100 (right side in FIG. 1).

As shown in FIG. 2, a plurality of (five in this embodiment) paper feed rollers 3 are attached to the paper feed roller shaft 3a. Some of them (in this embodiment, 3
) Has a rubber material 3b attached to its roller surface,
The paper P is wound around the surface so as to be easily fed. Another sheet feed roller 3 (2 in this embodiment)
No rubber material 3b is attached to the surface of
These paper feed rollers 3 assist the feeding of the paper P by the paper feed roller 3 having the rubber material 3b. These paper feed rollers 3 are rotated (forward rotation and reverse rotation) around a paper feed roller shaft 3a by a drive motor (not shown).

The transport roller 6 includes a drive roller 6a rotated by a drive motor (not shown) and a drive roller 6a.
a driven roller 6b that is driven and rotated by being pressed against
And The transport roller 6 is configured to sandwich the paper P between the drive roller 6a and the driven roller 6b, and transport the paper P at a constant pitch in the sub-scanning direction (left direction in FIG. 1).

The carriage 8 includes a carriage (not shown).
The motor is configured to reciprocate along the guide shaft 12 in the main scanning direction (the direction of the front and back of the paper in FIG. 1). An ink cartridge 8a is detachably mounted on the carriage 8, and the ink in the ink cartridge 8a is sent to a recording head 8b provided on the surface of the carriage 8 facing the paper P. The recording head 8b discharges ink from a nozzle row (not shown) formed on the surface facing the sheet P onto the sheet P conveyed onto the platen 9, thereby performing printing.

A control shaft 5 is provided obliquely below and behind the paper feed roller 3.
Are arranged in parallel with the feed roller shaft 3a. The control shaft 5 is rotatable (forward and reverse) independently of the paper feed roller 3, the transport roller 6, and the paper discharge roller 7 by a drive motor (not shown). 2 and 3
As shown in (1), a slit wheel 90 for detecting the rotation reference position of the control shaft 5 is attached to the left end of the control shaft 5. A slit (not shown) is formed in the slit wheel 90 in the radial direction, and an optical sensor (not shown) that allows light to pass through the slit is provided in the vicinity. The position at which the light of the optical sensor passes through the center of the slit is defined as the rotation reference position of the control shaft 5 (hereinafter, also referred to as the “position at a rotation angle of 0 °”). Also, FIG.
As shown in FIG.
Followed roller units 40 and 41, separation pad unit 30, and sheet return units 50 and 50 are provided.

Below the sheet feed tray 1, a hopper 2 and a hopper holder 18 as "recording material contact means" are arranged. The hopper 2 is attached to the bottom of the paper feed tray 1 so as to be rotatable about a hopper shaft 2a, and forms a part of the bottom. The hopper holder 18 is provided below the hopper 2. As shown in FIG. 2, the hopper holder 18 has a fulcrum shaft 18a, and is attached to a main body frame (not shown) of the printer 100 so as to be rotatable about the fulcrum shaft 18a. A spring 1 for urging the hopper holder 18 upward is provided at the right end of the hopper holder 18.
8b, and a protrusion 18c for pushing up the lower portion of the hopper 2 is formed at the left end.

As shown in FIG. 2, a key-shaped arm 18d extends from the right end of the hopper holder 18, and a hopper cam follower 18e is provided at the tip thereof.
Are formed. Hopper cam follower 18e
Are engaged with a hopper cam 21 (see also FIG. 3) as "first switching means" fixed to the control shaft 5.
With the rotation of the hopper cam 21 accompanying the rotation of the control shaft 5,
The hopper cam follower portion 18e comes into contact with the hopper cam 21 and is released from the contact, whereby the hopper holder 18 is configured to rotate and displace around the fulcrum shaft 18a. In addition, with the rotation displacement of the hopper holder 18, the hopper 2 also moves through the projection 18c to the hopper shaft 2a.
Is rotated around the center. Thus, the paper P placed on the hopper 2 is configured to be pressed against the roller surface of the paper feed roller 3 and released.

As described above, the hopper 2 serves as a point of action for rotating the hopper 2 between the fulcrum shaft 18a serving as a rotation fulcrum of the hopper holder 18 and the hopper cam follower portion 18e serving as a rotation power point. The projection 18c is provided. By arranging the operation points in this manner, errors in the amount of rotational displacement due to manufacturing tolerances of the hopper cam 21 and the hopper cam follower portion 18e can be reduced at the operation points. The amount of dynamic displacement can be further improved. Also, the force applied to the power point can be made smaller than when the power point is inside the action point,
As a result, the size of the motor for rotating the control shaft 5 and the power consumption can be reduced.

The hopper cam 21 and the hopper cam follower portion 18e, and the hopper holder 18 and the hopper 2 connected thereto will be described in detail later.

Returning to FIG. 1, near the side of the paper feed roller 3, an auxiliary roller 10 for assisting the feeding operation by the paper feed roller 3 is provided. The auxiliary roller 10 is supported by an auxiliary roller holder 10a. Auxiliary roller 1
At 0, the drive motor is not connected, and is configured to freely rotate in contact with the paper P as the paper P is fed.

A "separating means" provided with a pad holder 11 and a separating pad 11a at a lower rear portion of the sheet feeding roller 3.
Is provided as a separation pad unit 30 (see FIG. 2). As shown in FIG. 3, a "second switching means" fixed to the control shaft 5 is provided in the separation pad unit 30.
A pad cam 31 (not shown in FIGS. 1 and 2) is disposed as a pad holder.
It is engaged with the cam 31. The pad holder 11 is configured to be able to advance and retreat with respect to the paper feed roller 3 by the rotation of the pad cam 31 accompanying the rotation of the control shaft 5, and the separation pad 11a of the pad holder 11 Is pressed against the roller surface and is released. Rubber material 3b and paper P
, The friction coefficient between the separation pad 11a and the paper P is μ2, and the friction coefficient between the papers P is μ3.
Then, μ1>μ2> μ3. Further, the friction coefficient μ2 is set to be larger than a friction coefficient between a guide surface of a sheet guide member 16 described later and the sheet P.
The detailed contents of the separation pad unit 30 including the pad holder 11 and the separation pad 11a are described below.
Details will be described later.

A plurality of (three in this embodiment) paper feed driven rollers 4 are provided on the back surface of the paper feed roller 3. The paper feed driven roller 4 is provided in the driven roller units 40 and 41 (see FIG. 2), and is arranged to face the paper feed rollers 3 (three in this embodiment) having the rubber material 3b. The driven roller unit 40 has two feed driven rollers 4, and the driven roller unit 41 has one feed driven roller 4. As shown in FIG. 3, these driven roller units 40 and 41 have a "third"
Roller cams 42, 42 as "means for switching over"
(Not shown in FIGS. 1 and 2) are fixedly disposed on the control shaft 5 and are respectively engaged with the paper feed driven rollers 4. The paper feed driven roller 4 is configured to be able to advance and retreat with respect to the paper feed roller 3 by the rotation of the driven roller cam 42 accompanying the rotation of the control shaft 5, and is pressed against the roller surface of the paper feed roller 3; , Is released. The detailed contents of the driven roller unit 40 and the driven roller cam 42 having the paper feed driven roller 4 will be described later in detail.

A paper guide member 16 for guiding the paper P is provided around the paper feed roller 3 along the outer peripheral surface of the paper feed roller 3.
And 17 are provided at a fixed distance (for example, 2 mm) from the outer peripheral surface of the paper feed roller 3 (the outer peripheral surface of the rubber material 3). The arcuate guide surfaces (inner peripheral surfaces) of the guide members 16 and 17 are provided with a plurality of free rotations for smoothing the feeding of the paper P and preventing the paper P from being damaged. A movable guide roller 15 is mounted.

Between the paper feed roller 3 and the transport roller 6,
A paper detector 13 is attached. The paper detector 13 is
The leading end and the trailing end of the sheet P are detected. This detection signal is
It is provided to a control device (not shown) and is used for detecting the current position of the sheet P, identifying the size of the sheet P, and the like.

As shown in FIGS. 2 and 3, sheet return units 50 and 50 (not shown in FIG. 1) are provided near the sides of the separation pad unit 30 and the driven roller unit 41, respectively. ing. The paper return unit 50 on the right side is arranged so as to be located at substantially the center in the width direction of normal paper (for example, vertically long A4 size paper) P printed by the printer 100.

Each of the paper return units 50, 50 is provided with a paper return lever (not shown in FIGS. 1 to 3) as "recording material return means".
A paper return cam (not shown in FIGS. 1 to 3) as a "fourth switching means" is provided.
The paper return lever is configured to engage with the paper return cam, rotate and displace by rotation of the paper return cam accompanying rotation of the control shaft 5, and return the paper P to the paper feed tray 1 side. . The details of the sheet return unit 50 having the sheet return lever and the sheet return cam will be described later in detail.

Subsequently, the hopper 2, the hopper holder 18 and the hopper cam 21, the separation pad unit 30 and the pad cam 31, the sheet return unit 50 and the sheet return cam, and the driven roller unit 40 will be described below. And the driven roller cam 42 will be individually described in detail, and then, the sheet feeding operation by the cooperation of the whole will be described.

[Hopper, hopper holder and hopper
Configuration and Operation of Cam] First, the specific configuration and operation of the hopper 2, the hopper holder 18, and the hopper cam 21 will be described. 4A and 4B show the hopper cam 21. FIG. 4A is a side view, and FIG.
It is sectional drawing. The hopper cam 21 has a disc-shaped main body 21a having an insertion hole 21d through which the control shaft 5 is inserted and fixed.
And a bearing 21b of the control shaft 5 and a cam 21c. The cam portion 21c is formed integrally with the main body portion 21a and in an arc shape along the outer peripheral portion of the disk surface of the main body portion 21a so as to protrude in the rotation axis direction. Cam part 21c
Is a range of angles at which the hopper holder 18 maintains the lowered state (see FIG. 26 described later).

As shown in FIG. 2, the hopper cam 21 is disposed at a position where the cam portion 21c engages (contacts) the hopper cam follower portion 18e of the hopper holder 18 on the control shaft 5. And rotate integrally with the control shaft 5.

FIGS. 5 and 6 are flowcharts showing the flow of the operation of the hopper holder 18 and the hopper 2 accompanying the rotation of the hopper cam 21. FIG. 5A shows a state at the rotation reference position of the control shaft 5. The hopper cam follower portion 18e has a front slope in front (left side in FIG. 5).
A rear slope is provided rearward (right side in FIG. 5), and the top has a concave curved surface that substantially matches the curved surface of the cam portion 21c.

In the state shown in FIG. 5A, the outer peripheral surface of the cam portion 21c of the hopper cam 21 is in contact with the top (concave surface) of the hopper cam follower portion 18e. Thereby, the hopper holder 18 is moved to the hopper spring 18b (FIG. 1).
(See FIG. 2 and FIG. 5 and FIG. 6). The hopper 2 also maintains a lowered state (almost horizontal state) due to its own weight and the weight of the sheet P placed thereon. In this state, a slight gap 1 is provided between the hopper 2 and the projection 18c of the hopper holder 21.
The hopper 2 and the hopper holder 18 are arranged so that 8f is formed. This gap is provided so that the rotational displacement of the hopper holder 18 is not immediately transmitted to the hopper 2.
In addition, vibrations of the printer 100 are directly affected by the hopper 2.
It is provided so as not to be transmitted to.

FIG. 5B shows a state immediately before the control shaft 5 rotates clockwise from this state and the contact between the cam portion 21c and the hopper cam follower portion 18e is released. . FIG. 6A shows a state in which the control shaft 5 is further rotated clockwise. As the hopper cam 21 rotates, the contact position of the rear end of the cam portion 21c moves from the top of the hopper cam follower portion 18e to the front slope. Due to the contact with the front slope, the hopper holder 18
Due to the urging force of the hopper spring 18b, the hopper spring 18b slightly rotates counterclockwise about the fulcrum shaft 18a, and the protrusion 18c
Start contact with.

When the hopper cam 21 further rotates, the contact between the cam portion 21c and the hopper cam follower portion 18e is released. By releasing the contact, the hopper / holder 1
The fulcrum shaft 8 is driven by the biasing force of a hopper spring 18b.
It further rotates counterclockwise around a. This gives
The convex portion 18c pushes up the hopper 2, and the hopper 2 rotates counterclockwise about the hopper shaft 2a, and its front end (the right end in FIG. 6) rises. As a result, the sheet P (not shown in FIG. 6) placed on the hopper 2
(The outer peripheral surface of the rubber material 3b). In this state, as will be described in detail later, the paper feed roller 3 starts rotating counterclockwise, and the uppermost sheet of the paper P is wound around the paper feed roller 3 so that the paper P is fed. Then, the front end of the sheet P is fed to the position of the transport roller 6.

When the feeding of the paper P is completed, the control shaft 5 rotates clockwise again, and the front end of the cam portion 21c starts contacting the front slope of the hopper cam follower portion 18e.
Thereafter, as shown in FIG. 6B, the hopper comes into contact with the top of the hopper cam follower portion 18e. As a result, the hopper
The holder 18 rotates clockwise about the fulcrum shaft 18a, and the hopper 2 pushed up by the projection 18c also rotates clockwise about the hopper shaft 2a. As a result, the hopper holder 18 and the hopper 2
The state returns to the state similar to the state shown in FIG. And the rotating shaft 5
Further, it rotates clockwise and returns to the rotation reference position shown in FIG.

[Structure and Operation of Separation Pad Unit and Pad Cam] Next, separation pad unit 3
The specific configuration and operation of the 0 and the pad cam 31 will be described.

FIG. 7 shows the pad cam 31 and FIG.
Is a side view, and (b) is a BB cross-sectional view of (a). The pad cam 31 includes a cylindrical main body 31a having an insertion hole 31c through which the control shaft 5 is inserted and fixed, and a cam 31b. The cam portion 31b is a main body portion 31a.
And is formed so as to protrude radially on a part of the outer peripheral surface of the main body 31a. The range in which the cam portion 31b is formed is a range of angles at which the pad holder 11 maintains the state of being separated from the paper feed roller 3 (see FIG. 26 described later).

FIG. 8 is a side view showing the detailed structure of the separation pad unit 30, and FIG. 9 is a view (partial sectional view) as viewed from C in FIG. FIG. 10 is a sectional view taken along line DD of FIG. The separation pad unit 30 includes a pad holder 11, a separation pad 11a, and a first pad spring (compression coil spring).
(Spring) 11c, a pad spring holder 11d, and a pad release lever 11f. In addition, the separation pad unit 30 is provided with a pad base member (not shown) attached to a base frame (not shown) of the printer 100. The pad base member includes, as a part thereof, a pad guide member 16a for supporting the pad holder 11, and a pad release member.
A rotation shaft 116 of the lever 11f is formed. Further, the paper guide member 16 is provided with a stopper 16b for defining a separation distance of the pad holder 11 from the paper feed roller 3.

The pad holder 11 has a T-shape having a head portion 110 and a shaft portion 112. On the top surface of the head 110, a separation pad 11a is attached. The separation pad 11a has the friction coefficient μ2 described above.
(Coefficient of friction with paper P). The shaft portion 112 penetrates the pad guide member 16a, and the pad guide member 16a causes the shaft portion 112 to move forward and backward with respect to the paper feed roller 3 (that is, to move between the contact position with the paper feed roller 3 and the separated position). Will be guided.
The first pad spring 11c is provided around the shaft portion 112 and between the head portion 110 and the pad guide member 16a, and urges the pad holder 11 toward the paper feed roller 3. I have.

The pad spring holder 11d is
2 is attached to a lower end of the shaft 2 by a fixing member (for example, an E-ring) 11h so as to be integrally movable with the shaft 112. Inside the pad spring holder 11d, a second pad spring (compression coil spring) 11e and a spacer arranged at the upper end (end on the paper feed roller 3 side) of the second pad spring 11e. 11g is stored. The second pad spring 11e urges the spacer 11g toward the paper feed roller 3, and the urging force is set to be stronger than the urging force of the first pad spring 11c. Two rectangular openings 11 are provided on the upper surface of the pad spring holder 11d.
3 and 113 are formed so that the two hook-shaped tips 115 and 115 of the pad release lever 11f can directly press the spacer 11g through these openings 113 and 113. .

The pad release lever 11f is rotatably mounted on a rotation shaft 116 formed on a pad base member (not shown). At the center of the pad release lever 11f, a pad cam follower 117 extending to the position of the pad cam 31 in parallel with the control shaft 5 is integrally formed.

When the pad holder 11 stops when the lower surface (back surface of the top surface) of the head portion 110 of the pad holder 11 comes into contact with the stopper 16 b, the separation pad 11 a is brought into contact with the guide surface 160 of the paper guide member 16. It is disposed at a position slightly protruding toward the paper feed roller 3 (for example, a position protruding 0.5 mm). As a result, as will be described later, the paper P and subsequent papers are more likely to be separated from the uppermost paper, thereby preventing double feeding (that is, feeding two or more papers P one upon another). .

The stopper 16b is not provided on the pad base member attached to the paper guide member 16,
By providing the separation pad 11a directly on the paper guide member 16, the protrusion dimension of the separation pad 11a from the guide surface 160 can be set more accurately. Pad the stopper 16b
In the case where the pad / base member is provided on the paper guide member 16, a mounting tolerance is added when the pad / base member is provided on the paper guide member 16. However, when the stopper 16b is provided directly on the paper guide member 16, this mounting tolerance may be eliminated. Because you can.

Next, the operation of the separation pad unit 30 will be described with reference to FIG. 8, and FIGS. 11, 12 and 13. FIG. 11, FIG. 12 and FIG.
FIG. 9 is a flowchart showing the flow of the operation of the pad holder 11 accompanying the rotation of the pad cam 31, and is a continuation of FIG.
In these figures, FIG. 13 shows the state at the rotation reference position of the control shaft 5, but for convenience of description, the description will be made in order from FIG.

In the state shown in FIG. 8, the cam portion 31b of the pad cam 31 is not in contact with the pad cam follower portion 117, and the pad holder 11 is separated from the paper feed roller 3. No force is acting. For this reason,
The pad holder 11 is moved toward the paper feed roller 3 by the urging force of the first pad spring 11c, and
1a contacts (presses) the outer peripheral surface of the rubber material 3 of the paper feed roller 3
Let's stop.

FIG. 11 shows a state in which the control shaft 5 rotates clockwise from this state, and the contact between the cam portion 31b and the pad / cam follower portion 117 is started. The state where the control shaft 5 is further rotated clockwise is shown in FIG.
Is shown in With the rotation of the pad cam 31, the cam portion 31b presses the pad cam follower portion 117. As a result, the pad cam follower unit 117
It rotates counterclockwise about the rotation shaft 116, and its distal ends 115, 115 press the spacer 11 g in the pad spring holder 11 d in a direction away from the paper feed roller 3.

At this time, since the urging force of the second pad spring 11e is stronger than the urging force of the first pad spring 11c, the second pad spring 11e is not compressed, and
Is compressed, and the pad holder 1 is compressed.
1 and the pad spring holder 11d
Move in a direction away from Then, the head portion 110 of the pad holder 11 comes into contact with the stopper 16b, and the movement of the pad holder 11 and the pad spring holder 11d stops. By this movement, the separation pad 11a
Are arranged to be separated from the roller surface of the paper feed roller 3 and slightly protrude from the guide surface 160 of the paper guide member 16 by the stopper 16.

FIG. 13 shows a state in which the control shaft 5 is further rotated from this state. With the rotation of the pad cam 31 accompanying the rotation of the control shaft 5, the pad release lever 11f further presses the spacer 11g. On the other hand, the pad holder 11 and the pad spring holder 11d
Is restricted by the stopper 16b so as not to move. Therefore, the rotational displacement of the pad release lever 11f at this time is absorbed by the compression of the second pad spring 11e. As described above, by providing the stopper 16b and the second pad spring 11e, the accurate separation position of the separation pad 11a can be easily specified. That is, the dimensions of the pad cam 31, the pad spring holder 11d, and the pad release lever 11f do not need to be precise in order to accurately define the separation position of the separation pad 11a.

[Structure and Operation of Sheet Return Unit] FIGS. 14A and 14B show the sheet return cam 51, wherein FIG. 14A is a side view, and FIG. 14B is a sectional view taken along line EE of FIG. The paper return cam 51 includes a cylindrical main body 51a having an insertion hole 51c through which the control shaft 5 is inserted and fixed, and a cam portion 51b. The cam portion 51b is formed in a hook shape integrally with the main body portion 51a and on a part of the outer peripheral surface of the main body portion 31a.

FIG. 15 is a front view of the paper return unit 50, and FIG. 16 is a sectional view taken along line GG of FIG. FIG.
7 shows a main lever 52 and a sub lever 53 constituting the paper return unit 50, and (a) shows a main lever.
Left side view of lever 52, (b) is a front view of main lever 52, (d) is a left side view of sub lever 53, (e)
Is a front view of the sub-lever 53, and (c) shows a sub-lever indicated by the mounting angle when the sub-lever 53 is mounted on the main lever 52 in the state of the left side view shown in (a).
It is a left view of the lever 53.

As shown in FIGS. 15 and 16, the paper return unit 50 includes a main lever 52, a sub lever 53, a paper return holder 54, and a first lever spring (tensile coil spring) 55. And a second lever spring (torsion coil spring) 56. The urging force of the first lever spring 55 is set weaker than the urging force of the second lever spring 56. In the following, both the main lever 52 and the sub lever 53 may be collectively referred to as a “sheet return lever”.

As shown in FIGS. 17A and 17B,
The main lever 52 includes a hook-shaped lever portion 52a for hooking the leading end of the sheet and returning the sheet to the sheet feeding tray 1, and a main body portion 52b for accommodating the sub-lever 53 at a base end side of the lever portion 52a. And both are integrally formed. As shown in FIG. 16, when the leading end of the sheet P is located on the separation pad 11a of the pad holder 11, the lever portion 52a is set to a length that engages with the leading end.
At the base end of the main body 52b, an insertion hole through which the rotating shafts 53c, 53c of the sub lever 53 are inserted is formed, and the bearings 52c, which are the bearings of the rotating shaft 53c, are formed.
52c are integrally formed. Behind the left bearing 52c, it projects toward the inside of the main body 52b,
An arc-shaped main engaging projection 52d formed coaxially with the center axis of the bearing 52c is integrally formed.

As shown in FIGS. 17D and 17E,
The sub lever 53 is a cam portion 51b of the paper return cam 51.
And a paper return cam / follower portion 53a that engages with the main body portion 52b.
Both are integrally formed. A spring hook 53e to which one end of the first lever spring 55 is attached is formed integrally with the right end of the sheet return cam follower 53a. The other end of the first lever spring 55
As shown in FIG. 16, it is attached to the rear end of the paper return holder 54. Rotating shafts 53c, 53c rotatably inserted into and mounted on the bearings 52c, 52c are integrally formed on both side ends of the sub main body 53b. The sheet return cam / follower section 53 at the left end of the sub body 53b.
An arc-shaped sub-engaging projection 53d, which protrudes toward the outside of the sub-main body 53b and is formed coaxially with the center axis of the rotating shaft 53c, is integrally formed on the base end side of a. The sub-engaging protrusion 53d is arranged so as to be located outside the main engaging protrusion 52d when the sub-lever 53 is attached to the main lever 52.

The main lever 52 and the sub lever 53 are integrated as follows. That is, after the coil portion of the second lever spring 56 (see FIGS. 15 and 16) is attached to the left rotating shaft 53c,
c, 53c are fitted into bearings 52c, 52c.
By rotating the sub-lever 53 to the mounting angle of the sub-lever 53 shown in FIG. 17C with respect to the main lever 52 shown in FIG. The sub-engagement projections 53d are arranged so as to overlap each other. In this state, the two terminals of the second lever / spring 56 attached to the left rotating shaft 53c are connected to the main engaging projection 52d and the sub-engaging projection 5 overlapping each other.
It is attached so as to sandwich 3d.

FIG. 18 shows a state in which the main engaging projection 52d and the sub-engaging projection 53d are sandwiched by the second lever spring 56. Second lever spring 56
Urges the main engaging projection 52d and the sub-engaging projection 53d in the direction of the arrow shown in FIG. 18 so as not to separate the two from the overlapping state. The degree of the urging force of the second lever spring 56 will be described later in detail.

After the sub-lever 53 is attached to the main lever 52, both ends of the pivot shafts 53c, 53c are attached to the sheet return holder 54 so as to be pivotable, and the first lever spring 55 But the spring hook 5
3e and the rear end of the paper return holder 54,
The sub lever 53 is pulled backward (to the right in FIG. 16).

Next, the paper return operation by the paper return unit 50 will be described. FIGS. 16 and 19 show the operation when the paper P is returned to the paper feed tray 1 normally. Here, the case where the paper P is returned to the paper feed tray 1 normally means that the leading end of the paper P is on the separation pad 11a (for example, the contact center point (nip point between the roller surface of the paper feed roller 3 and the separation pad 11a). ) Near and upstream)
This refers to the case where the lever 52a engages with the leading edge of the paper P.
FIG. 16 shows a state where the control shaft 5 is at the rotation reference position. Further, the paper return unit 50 shown in FIG.
16 corresponds to the sectional view taken along the line GG in FIG. 15, as in FIG.

At the rotation reference position of the control shaft 5, the lever portion 52a of the main lever 52 is disposed at the "standby position" retracted inside the paper guide member 16 in a substantially upright state. When the sub lever 53 is pulled rearward by the first lever spring 55, the main lever 52 is also moved to the standby position by the main engaging projection 52d and the sub lever 52d sandwiched by the second lever spring 56. It is formed by being pulled rearward integrally with the sub lever 53 by the engaging projection 53d.
The main lever 52 is regulated by the paper return holder 54 so as not to rotate backward from the standby position, whereas the sub lever 53 is not regulated in this way. However, since the urging force of the second lever spring 56 is set to be stronger than the urging force of the first lever spring 55, the sub-lever 53 is not moved by the urging force of the second lever spring 56. -It stops at the standby position integrally with the lever 52.

At the rotation reference position, the cam portion 51b of the paper return cam 51 is connected to the paper return cam / follower portion 5.
3a and the pad holder 11
Is in a state of being separated from the paper feed roller 3.

From this state, the rotation of the paper return cam 51 accompanying the clockwise rotation of the control shaft 5 causes the cam portion 51b to rotate.
Abuts on the sheet return cam / follower section 53a and pushes the sheet return cam / follower section 53a forward from behind.
Thereby, the sub lever 53 and the main lever 5
2 rotates integrally in the counterclockwise direction, and the lever 52a rotates in a dashed line arc shown in FIG. 16 to be displaced to the "return position" shown in FIG. As a result, the lever 52
“a” engages with the leading edge of the sheet P located on the separation pad 11a, and returns the sheet P to the sheet feeding tray 1. The lever 52a is disposed at a position that does not come into contact with the paper feed roller 3 in the width direction of the paper P (that is, also in the main scanning direction, that is, the front and back sides of the paper in FIGS. 16 and 19). Is not obstructed by the paper feed roller 3.
On the other hand, as described above, since the right paper return unit 50 shown in FIG. 2 is located substantially at the center in the width direction of the paper P, the lever portion 52a acts on the central portion in the width direction of the paper P, The paper return operation is performed. As a result, the sheet can be returned more effectively than when it is applied to the side edge of the sheet P.

In the state shown in FIG. 19, the cam portion 51b
The contact between the main lever 52 and the sub lever 53 is released clockwise by the urging force of the first lever spring 55, and the standby position is released. Return to

FIGS. 20 and 21 show the operation when the paper P is not returned to the paper feed tray 1 normally. Here, the case where the paper P is not returned to the paper feed tray 1 normally means that the leading end of the paper P is located further downstream than the separation pad 11a (for example, near the nip point) and the lever 52
This means that a contacts the middle of the sheet P instead of the leading end. Normally, the next and subsequent sheets P are separated by the separation pad 11a, and the leading end is located near the nip point of the separation pad 11a. When pulled, the leading edge of the next or subsequent sheet P may be located downstream beyond the separation pad 11a. A similar situation may occur if the user turns off the power of the printer 100 during the feeding of the paper P and turns on the power again in that state. In addition,
FIG. 20 shows a state where the control shaft 5 is at the rotation reference position. The sheet return unit 50 shown in FIGS. 20 and 21 corresponds to a sectional view taken along line GG of FIG.

At the rotation reference position of the control shaft 5, the main lever 52, the sub lever 53, and the paper return cam 5
1, and separation pad 11a of pad holder 11
Is at the same position as shown in FIG.

From this state, the rotation of the paper return cam 51 accompanying the clockwise rotation of the control shaft 5 causes the cam portion 51b to rotate.
Abuts on the sheet return cam / follower section 53a and pushes the sheet return cam / follower section 53a forward from behind.
Thereby, the sub lever 53 and the main lever 5
Reference numeral 2 integrally rotates counterclockwise, and the lever portion 52a rotates in a dashed-line arc shown in FIG. However,
As shown in FIG. 21, during this rotation, the lever 52
a contacts the middle part of the sheet P. As a result, the lever 52a receives resistance due to the weight of the paper P,
The rotation of the lever 52a stops at a position where the lever 52a comes into contact with the paper P. On the other hand, the cam portion 51b pushes out the paper return cam follower portion 53a to try to further rotate the sub lever 53. At this time, only the sub lever 53
Rotate against the urging force of the lever spring 56. As a result, as shown in FIG. 21, both terminals of the second lever spring 56 are opened, and the main engagement projection 52d and the sub engagement projection 53
“d” is displaced to a state where only a part of them overlaps or a state where all do not overlap.

That is, when the resistance of the sheet P due to its own weight is applied to the lever portion 52a, the urging force of the second lever spring 56 stops the main lever 52 and turns only the sub lever 53. It is set to move.
As described above, when the lever 52a comes into contact with an intermediate portion of the sheet P, the lever 52a is configured to stop, so that the sheet P is not damaged by the lever 52a. . That is, when the lever 52a further rotates in the state shown in FIG. 21, the lower part of the paper P is pushed up, while the other part of the paper P is pressed by the paper feed roller 3, so that the lever 52a is Although the paper P is sandwiched by the paper rollers 3 and wrinkles or scratches may be generated on the paper P, these wrinkles and scratches are prevented by stopping the lever portion 52a.

In this case, the paper P is not returned to the paper feed tray 1.
Can be returned to the paper feed tray 1 by the clockwise rotation of the paper feed roller 3 as described later.

In the state shown in FIG. 21, the contact between the cam portion 51b and the paper return cam follower portion 53a is released, and the sub-lever 53 is first turned clockwise by the urging force of the first lever spring 55. After the main engagement projection 53d overlaps the main engagement projection 52d, the main lever 52 and the sub lever 53 integrally rotate clockwise and return to the standby position.

As will be described later, after the paper return operation,
After the main lever 52 and the sub lever 53 return to the standby position, the control shaft 5 is configured to be able to return to the rotation reference position by reversing. At this time, the sheet return cam 51 also rotates in the reverse direction. As a result, the cam portion 51b comes into contact with the sheet return cam / follower portion 53a in a direction opposite to the direction in which the sheet return operation is performed. In this case, since the main lever 52 is attached so as not to retreat from the standby position as described above, it is not rotated and displaced, but the sub lever 53 is provided with the second lever spring 56. It rotates clockwise in FIG. 16 against the force, and escapes from the contact of the cam portion 51b. Thus, the paper return cam 51 can return to the rotation reference position even by reverse rotation. Further, after the sub lever 53 escapes from the contact, the second lever spring 53
The state shown in FIG. 16 is returned by the urging force.

[Structure and Operation of Driven Roller Unit and Driven Roller Cam] Next, the specific structure and operation of the driven roller unit 40 and the driven roller cam 42 will be described. The driven roller unit 41 has substantially the same configuration as that of the driven roller unit 40 except that only one sheet feeding driven roller 4 is provided. I do.

FIG. 22 shows the driven roller cam 42.
(A) is a side view, (b) is FF sectional drawing of (a). The driven roller cam 42 has a cylindrical main body 42a having an insertion hole 42c through which the control shaft 5 is inserted and fixed.
And a cam portion 42b. The cam portion 42b is formed integrally with the main body portion 42a and protrudes in a radial direction on a part of the outer peripheral surface of the main body portion 42a. Cam part 42b
Is a range of angles (see FIG. 26 to be described later) in which the driven paper feed roller 4 is kept separated from the paper feed roller 3.

FIGS. 23 and 24 are side views showing the detailed structure of the driven roller unit 40, and FIG. 25 is a front view thereof. FIG. 23 shows a state where the control shaft 5 is at the rotation reference position.

The driven roller unit 40 includes a paper feed driven roller 4 and a slider 4 a for holding the paper feed driven roller 4.
And a driven roller spring (torsion coil spring) 43,
And a spring holder 44 for holding the driven roller spring 43.

The slider 4a is attached to the paper guide member 16. Two feed driven rollers 4 are rotatably attached to the slider 4a (while,
One feed driven roller 4 is rotatably attached to the slider 4a of the driven roller unit 41).

The right and left ends of the slider 4a are provided with first slider shafts 4b, 4b and second slider shafts 4c, 4c.
Are provided before and after. The first slider shafts 4b, 4b and the second slider shafts 4c, 4c are connected to two paper guide members 16 provided on the left and right sides of the slider 4a (that is, before and after in the main scanning direction) (see FIG. 25). (Not shown) are fitted into slide grooves 165 formed respectively, and are guided by the slide grooves 165 to move. Thereby, the slider 4a and the slider 4a
The feed driven roller 4 attached to the
5 and can be moved. Slider groove 16
The reference numeral 5 is lowered as the distance from the paper feed roller 3 increases (that is, as it moves backward). The descending inclination angle is set to, for example, 15 degrees with respect to the horizontal. A driven roller spring 43 is provided at the center of the slider 4a.
The contact part 4d with which the contact is made is integrally formed.

The spring holder 44 holds the paper guide member 16.
It is attached to the lower rear of the. A driven roller spring 43 is attached to the spring holder 44 with both terminals 43a and 43b rising upward. The coil portion 43c of the driven roller spring 43 has a coil shaft 44a provided on the spring holder 44 in the main scanning direction.
Are inserted and support the driven roller spring 43. Further, a terminal 43a located on the rear side (the right side in FIG. 23) of the driven roller spring 43 is supported forward by a rear wall rising on the back of the spring holder 43. The terminal 43b located on the front side (the left side in FIG. 23)
The support portion 4d of the slider 4a is urged forward (ie, toward the paper feed roller 3).

Driven roller cam 4 fixed to control shaft 5
Numeral 2 is arranged at a position where it contacts the terminal 43b of the driven roller spring 43. At the rotation reference position shown in FIG. 23, the cam portion 42b of the driven roller cam 42
b, and presses the terminal 43b backward. As a result, the terminal 43b is displaced clockwise about the coil part 43c. Since the slider groove 165 is formed so as to descend backward, the rotation of the terminal 43b causes the terminal 4b to move.
The slider 4a supported by 3b moves rearward (that is, in a direction away from the paper feed roller 3) along the slider groove 165 by its own weight. As a result, the paper feed driven roller 4 is arranged at a position separated from the paper feed roller 3.

At this separated position, the dimensions of the slider 4a, the driven roller cam 42 and the driven roller spring 43 are such that the roller surface of the paper feed driven roller 4 is
6 (slightly 1.0 mm, for example).
It is configured to protrude.

When the control shaft 5 is rotated clockwise from the rotation reference position to reach the state shown in FIG. 24, the contact pressing of the terminal 43b by the cam portion 42a is released. Thus, the terminal 43b urges the slider 4a toward the paper feed roller 3. As a result, the slider 4a moves toward the paper feed roller 3 along the slider groove 165, and the paper feed driven roller 4 comes into contact with the paper feed roller 3 and is pressed.

[Paper Feeding Operation in Printer] Next, the paper feeding operation of the printer 100 will be described in relation to the rotation angle of the control shaft 5. The rotation of the control shaft 5 and the rotation of the feed roller 3 (and the transport roller 6 and the discharge roller 7)
It is performed in synchronization with the control device (not shown) as follows.

FIG. 26A shows the rotation angle of the control shaft 5 and
The above-mentioned slit wheel 90, hopper 2 (and hopper holder 18), separation pad 11a (and pad holder 11), paper feed driven roller 4, and paper return lever (main lever 52 and sub lever 53) 6 is a time chart showing a relationship with each operation. FIG. 4B is a time chart showing the relationship between the rotation angle of the control shaft 5 and the rotation (forward rotation and reverse rotation) of the paper feed roller 3. FIG. 3C is a time chart showing the relationship between the rotation angle of the control shaft 5 and the reversible area of the paper feed roller 3.

In the time chart of FIG. 26A, a rectangular graph of "slit wheel" indicates that the slit of the slit wheel 90 has been detected by the optical sensor. "L" of "hopper" is hopper 2
Is located at a position separated from the paper feed roller 3, and "H"
Indicates that the hopper 2 is in a contact position with the paper feed roller 3. “L” of “separation pad” indicates separation pad 11.
a is located at a position separated from the paper feed roller 3,
"H" indicates that the separation pad 11a is in a contact position with the paper feed roller 3. "L" for "Paper driven roller"
Indicates that the paper feed driven roller 4 is at a position separated from the paper feed roller 3, and “H” indicates that the paper feed driven roller 4 is at a contact position with the paper feed roller 3. “L” of “paper return lever” indicates that the paper return lever is at the standby position, and “H” indicates that the paper return lever is at the paper return position.

Before the paper feeding operation is started, the optical sensor
By detecting the slit formed in the slit wheel 90, the control shaft 5 moves the rotation reference position (rotation angle 0).
Degree position). Here, slit wheel 9
The zero slit has a certain width, but since the width is known in advance, the position where the detection light of the optical sensor passes through the center of the slit in the width direction is set as the rotation reference position. The fixed width of the slit is θ ₀ (for example, 10.57 degrees) when the rotation angle of the control shaft 5 is set, and this section is hereinafter referred to as “first section”.

In the first section, the hopper cam 21
5A, as shown in FIG. 5A, is in contact with the hopper cam follower portion 18e of the hopper holder 18, and the hopper holder 18 and the hopper 2 maintain the lowered state. As a result, the paper P placed on the hopper 2 is located at a separated position separated from the paper feed roller 3. Pad cam 3
1 is in contact with the pad holder 11 as shown in FIG. 13, and the separation pad 11 a is at a separated position separated from the paper feed roller 3. The feed driven roller cam 42 is shown in FIG.
As shown in FIG. 3, the driven roller 4 is in contact with the driven roller spring 43, and the driven roller 4 is in a separated position separated from the feeding roller 3. As shown in FIG. 16, the paper return cam 51 does not push up the paper return lever, and the paper return lever is at the standby position. Further, the paper feed roller 3 is stopped.

From this rotation reference position, the control shaft 5 is moved to the angle θ _0.
2 (ie, clockwise rotation in FIG. 2), the contact between the paper return cam 51 and the paper return lever shown in FIG. 16 is started, and the control shaft 5 further rotates the angle θ ₁ (for example, 60 degrees). The contact is released by the forward rotation. As a result, as shown in FIGS. 16 and 19, the sheet return lever is displaced from the standby position to the return position, and returns to the standby position again. As a result, the sheet P on the separation pad 11a is returned.
Is returned to the paper feed tray 1. 20 and 21.
As shown in FIG. 7, there is a case where the sheet P is not returned, but the handling of the sheet P will be described later.

The control shaft 5 is further moved by the angle θ ₂ (for example, 10 °
This section is also referred to as a “second section” hereinafter. When the forward rotation is performed, the release of contact between the pad cam 31 and the pad release lever 11f starts, and the pad holder 11 moves toward the contact position where it comes into contact with the paper feed roller 3. When the control shaft 5 further rotates forward by an angle θ ₃ (for example, 30 degrees), the separation pad 11 a comes into contact with (presses against) the paper feed roller 3. The state of this contact position is determined by the angle (θ ₄ + θ ₅ +
θ ₆ + θ ₇ + θ ₈ ) and a part of the angle θ ₉ .

[0100] The second section, the section and the angle of the angle theta ₃ theta
_In section ₄ (hereinafter also referred to as “third section”),
The paper feed roller is configured to be able to reverse (that is, rotate clockwise in FIG. 1) (shown by a broken line in FIG. 26B). By rotating the sheet feed roller 3 in the third section where the separation pad 11a is in the contact position, the sheet P not returned by the sheet return lever is set.
20 (see FIGS. 20 and 21) is pressed against the paper feed roller 3 by the separation pad 11a, and thus is reliably returned to the vicinity of the nip point of the paper feed tray 1 or the separation pad 11a.

The reverse rotation of the paper feed roller 3 can be performed for each paper feeding operation, or can be performed once every several feeding operations. In addition, the paper feed roller 3
Is set to an angle sufficient to return the sheet P not returned by the sheet return lever to the vicinity of the nip point of the sheet feed tray 1 or the separation pad 11a.

When the paper feed roller 3 is rotated in the reverse direction, the control shaft 5 is also rotated in the reverse direction to return to the rotation reference position. Then, it turns again, and the sheet return operation by the sheet return lever is started. In this way, the paper P on the separation pad 11a is reliably returned to the paper feed tray 1 before feeding.

After the third section, the paper feed driven roller
The contact release between the cam 42 and the driven roller spring 43 is started.
And the angle θ₅(For example, 71.3 degrees)
The contact is completely released. This enables the feed driven roller
4 is displaced to the contact position, and comes into contact with the paper feed roller 3 (pressure contact).
I do. This contact position is the angle θ₅Angle θ following the section of ₆
Section (for example, 10 degrees, hereinafter also referred to as “fourth section”)
U. ), Angle θ₇Section, angle θ₈Section (for example, 1
0 degrees, hereinafter also referred to as “fifth section”. ), And angle θ
₉Is continued for a part of the section.

[0104] In the angle theta ₅ sections, the abutment release the hopper cam 21 and hopper holder 18, hopper holder 18 pushes up the hopper 2, as a result, the hopper 2 is displaced to the contact position Then, the paper P placed on the hopper 2 comes into contact with the paper feed roller 3. The abutting position is continued during part of the fourth section and angle theta ₇ sections.

In the fourth section in which all of the hopper 2, the separation pad 11a, and the paper feed driven roller 4 are in the contact position, the paper feed roller 3 and the transport roller 6 rotate forward to perform the paper feed operation ( FIG. 26 (b) shows a solid line). That is, since the hopper 2 is at the contact position, the paper P on the hopper 2 is pressed against the paper feed roller 3, wound around the paper feed roller 3 and fed. At this time, since the separation pad 11a presses the paper P between the paper feed roller 3 and the friction coefficient (μ1>μ2> μ3) described above, double feeding of the paper P is prevented. Only the top sheet P is fed toward the transport roller 6 through the U-shaped feeding path. Further, when the paper feed driven roller 4 abuts (presses) on the paper feed roller 3 during feeding, the conveyance force by the paper feed roller 3 is obtained, and the paper P is quickly and surely transferred to the conveyance roller 6. Can be fed.

In this paper feeding operation, a skew removing operation is performed to correct the skew of the paper P. That is, after the leading edge of the paper P is nipped by the transport roller 6, the transport roller 6 is once rotated in the reverse direction and then forward again to make the leading edge of the paper P parallel to the roller axis of the transport roller 6. After being made parallel, the leading edge of the paper P is recorded (printed).
It is sent to the start position.

The control shaft 5 is controlled to stop rotating in the fourth section until the sheet feeding operation is completed.

After the paper feeding operation is completed, the control shaft 5 is moved to the angle θ.
₇(For example, 87.8 degrees) while the hopper
The cam 2 contacts the hopper holder 18 again, and the hopper 2
Is displaced to the separated position. Subsequently, the control axis 5 is further angled
θ₈(Fifth section) and angle θ ₉(For example, 60 degrees)
Is rotated. Angle θ₉During rotation of the pad cam 31
The contact with the pad release lever 11f starts, and
The separation pad 11a is displaced to the separation position. In addition, the driven low
The contact between the la cam 42 and the driven roller spring 43 starts.
Then, the paper feed driven roller 4 is displaced to the separated position.

[0109] Then, the control shaft 5, further the angle theta _0/2
To return to the rotation reference position again. Thus, one rotation of the control shaft 5 completes one paper feeding operation. Incidentally, the sum of the angle from the angle theta ₀ described above to theta ₉ 36
Although the angle is 0 degrees, the angle described in parentheses as a specific value of each of these angles is partially rounded off, so the total of the specific angles described in parentheses is 360
Not a degree.

In this rotation reference position, that is, in the first section, the fed uppermost sheet P is printed while being transported by the transport roller 6. The control shaft 5 stops rotating until printing of the fed uppermost sheet P is completed. On the other hand, during printing, the paper feed roller 3 rotates (forwardly rotates) together with the transport roller 6 (illustrated by a solid line in FIG. 26B).
By rotating the paper feed roller 3 forward, the transport resistance (transport load or back tension) is reduced, and the transport accuracy by the transport roller 6 is improved.

In the first section, since the paper feed driven roller 4 is at the separated position, the back tension caused by the paper feed driven roller 4 can be eliminated. That is, when the paper feed driven roller 4 is at the contact position, the rear end of the paper P being printed is pressed between the paper feed roller 3 and the back tension is generated. Back tension due to pressing can be eliminated. Further, as described above, the paper feed driven roller 4 slightly protrudes from the guide surface 160 of the paper guide member 16 even at the separated position (see FIG. 23).
The contact friction resistance between the sheet P and the sheet P is eliminated, thereby also reducing the back tension.

In the first section, the separation pad 11a is also at the separated position, so that the paper P being printed is not subjected to back tension by the separation pad 11a. On the other hand, the paper P after the next rank is
In the case where the separation pad 11a is located on the separation pad 11a, the separation pad 11a is located at the separated position, and thus there is a possibility that the separation pad 11a is double-fed. However, as described above, since the separation pad 11a slightly protrudes from the guide surface 160 of the paper guide 16 at the separated position, double feeding is prevented.

FIG. 27 shows the separation pad 11 in the separated position.
The figure shows how double feed is prevented by a. Separation pad 11
a is a position near the downstream side of the sheet feeding tray 1 at the separated position.
It is located near the roller surface of the paper feed roller 3
You. In the vicinity of this downstream side, the uppermost application by the paper feed roller 3
Paper P₁Is the part where the winding of the top sheet P is started.
₁Draws a curved surface along the roller surface. On the other hand,
Paper P₂Of the paper feed roller 3 depends on its rigidity.
Roller surface (that is, the topmost sheet P₁Direction),
That is, toward the separation pad 11a at the separated position.
It has become. The separation pad 11a is used for the paper guide member 1.
6 slightly protrudes from the guide surface 160 of FIG.
Paper P after₂Is not the guide surface 160 but separates
It comes into contact with the pad 11a. The separation pad 11a is
₂Has the friction coefficient μ2 described above between
From paper P₂Is paper P₁It is pulled and fed by
And not. In addition, the friction coefficient μ2 is
Since it is larger than the coefficient of friction with paper, the guide surface 160
Double feed is more reliably prevented than when paper comes into contact with the sheet.
In addition, the separation pad 11a is
Being maintained in the contact position also contributes to the prevention of double feed.
You.

In FIG. 26, a sheet feeding operation different from the above-described sheet feeding operation can be performed. For example, when the control shaft 5 is located in the fourth section,
(And the transport roller 6) is rotated forward, and the paper P is sent out to the vicinity where the leading end of the paper P has passed the position of the paper feed driven roller 4, and
The feed roller 3 and the transport roller 6 are stopped once.
Subsequently, in this state, the control shaft 5 is rotated and positioned in the fifth section. In this fifth section, the paper feed roller 3
Then, the transport roller 6 is rotated forward again, and the paper P that has been fed to a position near the feed roller 4 is sent out to the position of the transport roller 6, and after the skew removing operation, it is sent out to the print start position. Thereafter, the control shaft 5 is positioned in the first section, and the sheet feeding operation ends.

By performing such a sheet feeding operation, before the sheet feeding operation is completed, the hopper 2 is lowered, and the pressing of the sheet P placed on the sheet feeding tray 1 to the sheet feeding roller 3 is released. . Thereby, the uppermost sheet P ₁ during the sheet feeding operation
Because pressing state is shortened by the hopper 2 between the paper P ₂ of the next or subsequent and, it is possible to prevent the occurrence of double feed.

The time when the hopper 2 is displaced from the separated position to the contact position and the time when the paper feed driven roller 4 is displaced from the separated position to the contact position may be the same. Further, in the present embodiment, an embodiment in which the present invention is applied to a printer has been described, but it goes without saying that the present invention is also applicable to a recording device such as a copying machine and a facsimile.

[0117]

According to the present invention, the first switching means,
The second switching means, the third switching means, and the fourth switching means are mounted on one control shaft, and the position is switched by the switching means by one rotation of the control shaft. . Therefore, the control mechanism of these switching means can be simplified and can be performed by one control axis, so that the number of parts can be reduced, and as a result, the recording device can be reduced in weight and size, and The price can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an ink jet printer.

FIG. 2 is a plan view (top view) of the ink jet printer, mainly showing a hopper, a hopper holder, a control shaft, and a paper feed roller.

FIG. 3 is a plan view (top view) showing a control axis.

FIG. 4 (a) is a side view of a hopper cam,
(B) is AA sectional drawing of (a).

FIG. 5 is a flowchart showing a flow of operations of a hopper holder and a hopper accompanying rotation of the hopper cam.

FIG. 6 is a flowchart showing a flow of operation of the hopper holder and the hopper accompanying rotation of the hopper cam.

FIG. 7A is a side view of a pad cam, and FIG.
FIG. 3A is a sectional view taken along line BB of FIG.

FIG. 8 is a side view showing a detailed configuration of a separation pad unit.

9 is a view (partial sectional view) as viewed from C in FIG. 8;

FIG. 10 is a sectional view taken along line DD of FIG. 9;

FIG. 11 is a flowchart showing a flow of an operation of the pad holder accompanying rotation of the pad cam.

FIG. 12 is a flowchart showing a flow of an operation of a pad holder accompanying rotation of a pad cam.

FIG. 13 is a flowchart showing a flow of an operation of the pad holder accompanying rotation of the pad cam.

FIG. 14A is a side view of a paper return cam,
(B) is EE sectional drawing of (a).

FIG. 15 is a front view of the paper return unit.

FIG. 16 is a sectional view taken along line GG of FIG. 15;

FIG. 17A is a left side view of the main lever, and FIG.
Is a front view of the main lever, (d) is a left side view of the sub lever, (b) is a front view of the sub lever, and (c)
5A is a left side view of the sub lever 53 shown at an attachment angle when the sub lever is attached to the main lever in the state of the left side view shown in FIG.

FIG. 18 illustrates a state where the main engagement protrusion and the sub-engagement protrusion are sandwiched by a second lever spring.

FIG. 19 is a side view showing the operation when the paper is returned to the paper feed tray normally.

FIG. 20 is a side view illustrating an operation when a sheet is not normally returned to the sheet feeding tray.

FIG. 21 is a side view illustrating an operation when a sheet is not normally returned to a sheet feeding tray.

FIG. 22 (a) is a side view of a driven roller cam,
(B) is FF sectional drawing of (a).

FIG. 23 is a side view showing a detailed configuration of a driven roller unit.

FIG. 24 is a side view showing a detailed configuration of a driven roller unit.

FIG. 25 is a front view showing a detailed configuration of a driven roller unit.

FIG. 26 (a) shows the rotation angle of the control shaft and the slit angle.
6 is a time chart showing the relationship between the operations of a wheel, a hopper (and a hopper holder), a separation pad (a pad holder), a paper feed driven roller, and a paper return lever (a main lever and a sub lever). (B)
6 is a time chart illustrating a relationship between a rotation angle of a control shaft and rotation (forward rotation and reverse rotation) of a sheet feeding roller. (C)
5 is a time chart showing a relationship between a rotation angle of a control shaft and a reversible area of a sheet feeding roller.

FIG. 27 is a diagram showing a state of preventing double feed by a separation pad at a separated position.

[Description of Signs] 100 Ink jet printer 1 Paper feed tray 2 Hopper 3 Paper feed roller 4 Paper feed auxiliary roller 5 Control shaft 6 Conveyance roller 8 Carriage 11 Pad holder 11a Separation pad 18 Hopper holder 18e Hopper cam Follower unit 21 Hopper cam 30 Separation pad unit 31 Pad cam 40, 41 Follower roller unit 42 Follower roller cam 43 Follower roller spring 50 Paper return unit 51 Paper return cam 52 Main lever 53 Sub lever 53a Paper back cam follower section _P, P _1, P ₂ printing paper

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kiyoto Komuro 3-5-5 Yamato, Suwa-shi, Nagano F-term (reference) in Seiko Epson Corporation 3F343 FA02 FB04 GA01 GB01 GC01 GD01 HD17 JA18 JD08 KA04 KB05 KB06 KB17 LA04 LA15 LC11 LC14 LC22 MB03 MC19 MC23

Claims (10)

[Claims] A feed roller that feeds a recording material to a recording unit that records on the recording material by rotating the recording medium forward and backward, and a recording medium on which the recording material is placed; The recording material storage section, a contact position where the recording material placed in the recording material storage section contacts the paper feed roller, and a separation position where the recording material is separated from the paper supply roller. A recording material contacting means which can be disposed, a contact position contacting the paper feeding roller, and a separation position separating the recording material from the paper feeding roller; Separating means for separating the uppermost one of the recording materials placed in the storage part from the latter one, and a contact position for contacting the paper feed roller and a separation from the paper feed roller To be in contact with the paper feed roller. Thus, a paper feed driven roller that is driven and rotated in accordance with the rotation of the paper feed roller, a return position for returning the recording material on the separating means to the recording material storage portion, and a standby position other than the above. A recording material return means for returning the recording material on the separating means to the recording material storage unit by displacing the recording material from the standby position to the return position. What is claimed is: 1. A sheet feeding device for feeding a recording material, comprising: first switching means for switching between a contact position and a separation position of the recording material contact means; and a contact position and a separation position of the separation means. , Second switching means for switching between a contact position and a separation position of the paper feed driven roller, and fourth switching means for switching between a return position and a standby position of the recording material return means. And means are further provided. Said first switching means, said second switching means by said third switching means and said fourth switching means is attached to one of the control shaft, the control shaft is rotated 1,
The sheet feeder, wherein the switching of the positions by the switching means is performed. 2. The method according to claim 1, wherein the control shaft starts rotating from a rotation reference position serving as a rotation reference before feeding the recording material from the recording material storage unit. The fourth switching means switches the recording material return means from the standby position to the return position, and then switches from the return position to the standby position again. Subsequently, the second switching means switches the separation means from the separated position. Switch to the contact position,
Switching means switches the paper feed driven roller from the separated position to the contact position, and subsequently or simultaneously, the first switching means switches the recording material contact means from the separated position to the contact position. Paper feeder, characterized in that: 3. The paper feed roller according to claim 2, wherein the first switching unit switches the recording material contact unit from the separated position to the contact position, and then the paper feed roller rotates forward. And a sheet feeding device. 4. The sheet feeding driven roller according to claim 2, wherein after the second switching means switches the separation means from the separation position to the contact position, the third switching means moves the paper feed driven roller to the separation position. Before switching to the abutment position, the paper feed roller is configured to reverse.
A sheet feeding device, characterized in that: 5. The paper feeder according to claim 4, wherein the control shaft is configured to reversely return to the rotation reference position and return after the paper feed roller reversely rotates. 6. The control shaft according to claim 3, wherein the control shaft rotates after the sheet feed roller rotates forward and the uppermost recording material is fed. The first switching means switches the recording material contact means from the contact position to the separated position, and the third switching means switches the paper feed driven roller from the contact position to the separated position. And the second switching means is configured to switch the separating means from the contact position to the separated position. 7. The sheet feeding roller according to claim 6, wherein the sheet feed roller rotates forward after the second switching unit switches the separation unit from the contact position to the separation position. Paper feeder. 8. A recording apparatus comprising the sheet feeding device according to claim 1. Description: 9. A paper feed roller which is capable of normal rotation and reverse rotation and feeds a recording material to a recording unit which performs recording on the recording material by rotating forward, and a recording medium on which the recording material is placed. The recording material storage section, a contact position where the recording material placed in the recording material storage section contacts the paper feed roller, and a separation position where the recording material is separated from the paper supply roller. A recording material contacting means which can be disposed, a contact position contacting the paper feeding roller, and a separation position separating the recording material from the paper feeding roller; Separating means for separating the uppermost one of the recording materials placed in the storage part from the latter one, and a contact position for contacting the paper feed roller and a separation from the paper feed roller To be in contact with the paper feed roller. Thus, a paper feed driven roller that is driven and rotated in accordance with the rotation of the paper feed roller, a return position for returning the recording material on the separating means to the recording material storage portion, and a standby position other than the above. A recording material return means for returning the recording material on the separating means to the recording material storage unit by displacing the recording material from the standby position to the return position. A method for feeding a recording material, wherein the recording material return means is switched from a standby position to a return position by a fourth switching means attached to the control shaft when the control shaft rotates, and then again. The separation means is switched from the return position to the abutment position by the second switching means attached to the control shaft, and then to the third position attached to the control shaft. Off The paper feed driven roller is switched from the separated position to the contact position by the changing means, and subsequently or simultaneously, the recording material contact means is moved from the separated position to the contact position by the first switching means attached to the control shaft. And then rotating the paper feed roller. 10. The control device according to claim 9, wherein the control shaft is rotated after the sheet feeding roller rotates forward and the uppermost recording material is fed, so that the first switching unit causes the control unit to rotate. The recording material contacting means is switched from the contacting position to the separated position, and then the paper feed driven roller is switched from the contacting position to the separated position by the third switching means, followed by the second switching means. The method according to claim 1, further comprising: switching the separation unit from a contact position to a separation position by rotating the paper feed roller.