JPS6397535A - Sheet supply and feed device for printer - Google Patents

Abstract

PURPOSE:To eliminate frictional load in a sheet as well as to aim at improvement in sheet feeding accuracy, by making a separate roller so as to be separated from the sheet with a moving device at the time when a sheet front part has reached a position capable of feeding it with a sheet feed roller after starting the separate roller for rotation. CONSTITUTION:A separate roller 4 is rotated in a sheet feed C direction, and only one sheet of the cut sheet 29 on a topmost position is delivered to the side of a feed, getting over a separate claw 2, and it collides with a clearance between the roller 10 and a pinch roller 26, making a motor 24 constantly rotate up to the specified time t2 making a curve of the preset quantity. Next, when reaching the time t2, it makes the motor 24 turn off and simultaneously makes a motor 11 turn on, rotating the roller 10. Next, when turning a motor 11 to ON, a rod 30A is contracted, and thereby a shaft 6 is moved in an E direction. At this time a separate roller gear 22 makes the roller 4 move upward, whereby the roller 4 is moved in an H direction and comes off the cut sheet 29, thus the sheet 29 is accurately delivered without entailing any frictional load with the roller 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application under Plan A 1] The present invention relates to a sheet feeding device for a printer that is capable of automatically feeding cut sheets such as recording paper.

[Prior Art] FIG. 7 shows a general configuration example of a conventional printer equipped with this type of sheet feeding device. In this figure, 1 is a slider unit that accommodates cut sheets, 2 is a separation claw that separates and sends out the cut sheets stacked on the pressure plate 3 one by one, and 4 separates and feeds the cut sheets on the pressure plate 3. This is a separation roller with a circular cross section.

The separation roller 4 is made of an elastic member such as rubber, and is fixed to a separation roller base 5. The separation roller 4 is formed of an elastic member such as rubber, and is fixed to a separation roller base 5.
A and 5B are formed. The separation roller 4 is also called a feeding roller or a paper feeding roller, and the separation roller 4 and its base 5 are slidably fitted to the separation roller glaze 6 on both the left and right sides, and the separation roller @I+6 has a rectangular or D-shape shape. By having a non-circular cross section such as a mold, the splitting roller 4
And the base body 5 can be rotated together with the separation roller flf16.

The left and right slider units 1 are slidably held by a unit guide @7, and this guide shaft 7 is supported by a fixed side plate (not shown), and a long guide groove is formed along the axis. Reference numeral 8 denotes a feeding lever attached to the end of this guide shaft 7, and when feeding a sheet, the cut sheet is fed onto the pressure plate 3 by tilting the lever 8 in the direction of arrow A in this figure. be able to. Reference numeral 9 denotes a pressure plate pressing arm that holds the pressure plate 3 and is capable of swinging the pressure plate 3 up and down in response to rotation of the guide shaft 7 by the feeding lever 8.

10 is a sheet feed roller made of a material with a high coefficient of friction such as rubber; 11 is a sheet feed motor that rotationally drives the sheet feed roller 10; 12 is a platen roller made of a material with a high coefficient of friction such as rubber; 13 are discharge rollers for discharging sheets, and these rollers 12 and 13 are interlocked with the sheet feed roller 10 by a sheet feed motor 11 via gears. Both the left and right discharge rollers 13 are made of a material with a high friction coefficient such as rubber, and are attached to a predetermined position on the discharge roller shaft 13A. Parallel engaging grooves are provided around the periphery for the purpose of the locking. 14 is a spur holder that holds a gear-shaped sheet pressing spur in contact with these discharge rollers 13; 15 is a discharge roller 1;
This is a stocker that stores the cut sheets discharged by the rotation of No. 3.

Further, 16 is a carrier that is driven along guide shafts 19A and 19B by a carrier motor 17 and a transmission means 18 such as a timing belt, and this carrier 16 is equipped with a print head, for example, an inkjet bed 20, and prints. By supplying a recording signal to each nozzle provided in the head 20, ink can be ejected from the nozzle to perform recording. 21 is an ink tank.

22 is a separation roller gear 22 fixed to one end of the shaft 6 of the separation roller 4; 23 is a gear that meshes with this gear 22; and 24 is a separation roller drive motor that rotationally drives the separation roller 4 via the gears 22 and 23.

FIG. 8 shows a cross-sectional structure of the sheet feeding mechanism of the conventional apparatus taken along the line XX in FIG. 7. In FIG. 8, IA is a guide tube that stands up from the bottom of the slider unit 1 and into which the guide column 3A of the pressure plate 3 is slidably fitted. 9A is a protrusion for preventing rotation that engages with the long groove of the unit guide shaft 7, and the hook-shaped arm portion 9B of the pressure plate pressing arm 9
is engaged with the engagement hole 3B on the back side. 25 is a pressure plate spring that holds the pressure plate 3 in a lifted state, and is connected to the above-mentioned guide column 3A.
and is interposed on the outer peripheral surface of the guide tube IA. As shown in FIG. 7, the separation claw 2 is rotatably attached to the slider body 1 via a shaft pin 2A, and its clockwise rotation is controlled by the stopper portion 2B at the upper end of the separation claw member. It is regulated by contacting the flange portion 5B of the separation roller base 5 from below.

26 is a pinch roller that comes into contact with the sheet feed roller lO;
27 is a sheet absence detection switch that detects that there is no cut sheet between the pair of pinch rollers 26;
[This is a gutter-shaped seat pan that guides you to +.

FIG. 9 shows a state in which the cut sheet 29 is set in the sheet feeding mechanism shown in FIG. First, when setting the cut sheet 29 between the pair of left and right slider units 1.1,
When the slider unit 1.1 is moved to set its width to the width of the cut sheet 29 and the feeding lever 8 shown in FIG. The pressure plate 3 is lowered via the lowering arm 9 against the biasing force of the spring 25, and a locking claw (not shown) and an engagement square hole engage, thereby locking the pressure plate 3 to the bottom of the slider unit 1. be able to.

Next, a plurality of cut sheets 29 are accumulated on the pressure plate 3,
Align the tip of the cut sheet 29 so that it abuts against the separation claw 2, and then rotate the feeding lever 8 in the direction opposite to the direction of arrow A to release the locking state of the locking claw and release the spring. When the pressure plate 3 is pushed up and biased upward by the elastic force of the sheet 25, the cut sheet 29 is sandwiched between the feeding roller 4 and the pressure plate 3, and the feeding roller 4 is placed on the upper surface of the sheet 29.
comes into contact and sheet setting is completed.

Next, the separation roller drive motor 24 is driven, and the gear 2
A pair of left and right separation rollers 4.4 rotate through the rollers 3 and 22, and as the rotation of the separation rollers 4 in the direction of arrow C progresses, the frictional force of the rollers 4 causes the separation of the topmost sheet. Only the cut sheet 29 passes over the separation claw 2 and is sent out to the sheet pan 28 side, and the cut sheet 2
The tip of the sheet 9 is guided and sandwiched between the pinch roller 26 and the sheet feed roller 10. Since the pinch roller 26 is pressed against the sheet feed roller 10 by a spring (not shown),
The sheet feed roller 1 is driven by the sheet feed motor 11.
0 is rotated in the direction of the arrow, the cut sheet 29
is sent to a height opposite the print head 20. The sheet feeding state at this time is shown in FIG.

[Problems to be Solved by the Invention] However, at this time, the separation roller 4 has already stopped rotating at the timing when the leading end of the cut sheet 29 is sandwiched between the pinch roller 26 and the sheet feed roller 10. The rear part of the cut sheet 29 is pressed against the separation roller 4 by the spring 25. The separation roller 4 is originally made of a material such as rubber to increase the coefficient of friction so that the cut sheets 29 can be easily separated and conveyed one by one.
When the sheet is being fed after it has stopped, a large frictional force F acts between the separation roller 4 and the cut sheet 29 in the direction of the arrow in the figure, which is the opposite direction to the sheet feeding direction. Therefore, this frictional force F becomes a non-negligible load on the sheet feeding of the cut sheet 29 by the sheet feed roller 10 and the pinch roller 26, which reduces the cueing accuracy and causes the cut sheet 29 to skew. There were drawbacks such as.

The present invention provides a sheet feeding device for a printer that can eliminate the above-mentioned drawbacks, eliminate the frictional load between the separation roller and the cut sheet when the sheet feeding roller is feeding the sheet, and improve the sheet feeding accuracy. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses a separation claw to press a plurality of sheets stacked in a sheet storage section and separate the sheets into one sheet.
A separation roller that separates the sheets one by one and feeds them to the sheet feed roller, a moving means that moves the separation roller to a position away from the sheets, and after the separation roller starts rotating, the front part of the sheet is fed by the sheet feed roller. The present invention is characterized in that it includes a moving control means for driving the moving means to move the separation roller away from the sheet at the timing when the separation roller reaches a position where the separation roller can be moved away from the sheet.

[Function] In the sheet feeding device of the printer of the present invention configured as described above, after the separation roller starts rotating, C is activated at the timing when all of the sheets reach a position where the sheet feeding roller can feed
A moving means such as a solenoid actuator is driven by a B-motion control means such as a PU, and the separation roller is moved eight times to a position where it leaves the sheet, so when the cut sheet is fed by the sheet feed roller that feeds the sheet to the printing position, the separation roller is Since it is separated from the sheet, the frictional load caused by the separation roller's contact with the sheet is eliminated, resulting in accurate feeding, improved cueing accuracy, and elimination of skew.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of essential parts of an embodiment of the present invention. 1st
In the figure, reference numeral 30 denotes a separation roller lift solenoid that moves the separation roller shaft 6 that rotates the separation roller 4 in the upward arrow E direction. 31 is a link that connects the separation roller gear 22 and a gear 23 that meshes with this gear 22, and allows the gear 22 to rotate freely around the gear 23 while being meshed with it.

When the solenoid 30 is energized and its rod 30A is retracted upward, the gear 22 rotates upward around the gear 23 via the link 31, causing the separation roller 4 to move upward eight times via the shaft 6. As a result, the separation roller 4 separates from the cut sheet 29 as described later.

6A is a bearing portion of the separation roller IP [h6 that slides on the rod 3OA of the solenoid 30. In addition, solenoid 30
may be provided on both the left and right sides. The rest of the mechanical configuration is almost the same as the conventional device described in FIGS. 7 and 8, so the details will be omitted.

FIG. 2 shows a schematic configuration of an electrical system for controlling the drive of the separation roller lift solenoid 30 shown in FIG. 1 and other control operations according to the present invention. In FIG. 2, reference numeral 32 denotes a calculation control unit (CPU) that controls control operations according to the present invention according to the control procedure shown in FIG.
A general microcomputer having a memory such as M or RAM, a timer, etc. can be applied. 33 is a separation roller drive motor controller (control unit) that drives and controls the separation roller drive motor 24 in accordance with control instructions from the CPII 32; 34 is a sheet that drives and controls the sheet feed motor 11 in accordance with control instructions from the CPU 32; It is a feed motor controller. Further, a sheet absence detection switch 27 is connected to an input terminal of the CPU 32, and a separation roller lift solenoid 30 is connected to an output terminal of the CPU 32.

3 is a flowchart showing the control operation procedure of the CPU 32 in FIG. 2, FIG. 4 is a timing chart showing the timing of the control operation, and FIGS. 5 and 6 are the steps shown in FIGS.
The sheet feeding state in the embodiment of the present invention shown in FIG. 4 is shown. Note that (tl
), (tl), (t3), (t5).

(t6) and (t7) are each step tl, t2. t3. t5. t6. It is assumed that the timings correspond to t7.

Next, an example of the operation of the embodiment of the present invention will be described with reference to the flowchart of FIG. 3 and FIGS. 4 to 6. FIG. 5 shows the initial state in which the cut sheet 29 is set between the pressure plate 3 and the separation roller 4. In this state, when the CPU 33 receives a sheet feeding instruction from an operation button (not shown) or the host computer, it outputs a sheet feeding start command to the separation roller drive motor controller 33 to rotate the separation roller drive motor 24. . When the motor is started, the solenoid 30 is in the OFF state, and as the drive motor 24 rotates, the separation roller 4 rotates in the sheet feeding direction of arrow C in FIG. Only one of the cut sheets 29 at the upper position is sent out to the sheet feeding roller IO side.

The fed-out cut sheet 29 climbs over the separation claw 2, is guided by the sheet pan 28, and is moved to the sheet feed roller 10.
and the front pinch roller 26 until a predetermined time (tl) that creates a slight curvature of a predetermined amount.
The CPt 132 continues to rotate the separation roller drive motor 24 at a constant rate (step tB).

Next, when the time (tl) is reached, the CPt 132 moves to step t2 and turns off the separation roller drive motor 24.
At the same time, the sheet feed motor 11 is turned on and started via the sheet feed motor controller 34, and the sheet feed roller 10 is rotated.

Next, the CPU 32 proceeds to step t3, and turns on the solenoid 30 to make it energized at a time (t3) immediately after the sheet feed motor 11 starts rotating. Due to this energization, the rod 30A of the solenoid 30 is shortened, and the shaft 6 is
Move in the direction of arrow E in the figure. At this time, since the separation roller gear 22 and the gear 23 are connected through the link 31, the separation roller gear 22 rotates around the rotation axis of the gear 23 like a planetary gear, as shown in FIG. , moves the separation roller 4 upward.

Due to the rotation of the sheet feed roller 10, the cut sheet 29
is sandwiched between the pair of pinch rollers 26 and the sheet feed roller 10 and fed to the printing position, but at this time the separation roller 4 has already moved in the direction of arrow H in FIG. 6 and is separated from the cut sheet 29. Since the cut sheet 29 is not in contact with the cut sheet 29, the cut sheet 29 fed between the sheet feed roller 1o and the pinch roller 26 is accurately fed to the printing position without causing any frictional load with the separation roller 4. .

Next, the CPU 32 moves to step t4 and waits for input of a sheet absence detection signal from the sheet absence detection switch 27.

The cut sheet 29 being fed is fed to the printing end position,
When the rear end passes the contact point of the sheet absence detection switch 27, a sheet absence detection signal is sent from the sheet absence detection switch 27 to the CPU 32. When the CP port 32 receives this no-sheet detection signal, it proceeds to step t5.
As in the state shown in FIG. 5, at the timing (t5) when there is no cut sheet 29 on the sheet feed roller 10, the sheet feed motor 11 is turned off to end the sheet feeding operation.
Next, in step t6, the energization to the separation roller lift solenoid 30 is stopped to turn it off. When the solenoid 30 is turned off, the rod 30A extends downward, so the separation roller shaft 6 moves downward, and the separation roller 4 comes into pressure contact with the cut sheet 29, leading to the next feeding operation as shown in FIG. enters standby state.

[Effects of the Invention] As explained above, according to the present invention, the separation roller is moved in the direction away from the cut sheet at the timing when the front part of the cut sheet reaches a position where it can be fed by the sheet feed roller. Therefore, the frictional load caused by the contact between the separation roller and the cut sheet when the cut sheet is fed by the sheet feed roller is eliminated, resulting in accurate feeding, which in turn improves cueing accuracy and eliminates skew. Effects such as this can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of the separation roller moving mechanism according to the embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the control system according to the embodiment of the present invention, and FIG. 3 is the control procedure of the CPU shown in FIG. 2. FIG. 4 is a timing chart showing the operation of the embodiment of the present invention; FIG. 5 is a sectional view showing the state before sheet feeding in the embodiment of the present invention; FIG. 6 is a flowchart showing the operation of the embodiment of the invention. 7 is a perspective view showing the overall structure of a sheet feeding device of a conventional printer; FIG. 8 is a sectional view showing a sectional structure of a sheet feeding mechanism of a conventional printer; FIG. FIG. 9 is a sectional view showing the conventional device in a state before sheet feeding, and FIG. 10 is a sectional view showing the conventional device in a state during sheet feeding. DESCRIPTION OF SYMBOLS 1...Slider unit, 2...Separation claw, 3...Press plate, 4...Separation roller, 5...Separation roller base, 6...Separation roller shaft, 7...Unit guide shaft , 8... Feeding lever, 9... Pressure plate pressing arm, lO... Sheet feeding roller, 11... Sheet feeding motor, 12... Platen roller, 22... Separation roller gear, 23. ... Gear, 24 ... Separation roller drive motor, 25 ... Spring, 26 ... Pinch roller, 27 ... No sheet detection switch, 29 ... Cut sheet, 30 ... Solenoid, 31. ...Link, 32...CPU. 33... Separation roller drive motor controller, 34.
...Sheet feed motor controller. Block diagram 2r showing the structure of the seven rows of 0 stripes of P series/)
j1

Claims (1)

[Scope of Claims] 1) a) a separation roller that separates the sheets one by one using a separation claw while pressing against a plurality of sheets stacked in a sheet storage section and feeds the sheets to a sheet feeding roller; b) ) a moving means for moving the separation roller to a position away from the sheet; c) a moving means for moving the separation roller to a position away from the sheet; A sheet feeding apparatus for a printer, comprising: a movement control means for driving the separation roller to separate the separation roller from the sheet.