JPH03211123A - sheet feeding device - Google Patents

Abstract

PURPOSE:To enable makeup feeding of sheets even during paper feeding by moving an operating means into an operating position at the time of a sheet 'no' signal being emitted from a sheet existence detecting means and into a refuge position at the time of a sheet 'yes' signal being emitted. CONSTITUTION:In case a sheet 'no' signal is emitted from a sheet existence detecting means 36 on the sheet stacked state of a sheet stacking means 3, an operating means 10 is placed into an operating position A to separated sheets S to be inserted into the sheet stacking means 3 from a feeding means 5 so as to insert the sheets S smoothly into the sheet stacking means 3. When a sheet 'yes' signal is emitted, the operating means 10 recedes into a refuge position B to make sheet feeding possible, so that the sheets S to be makeup-fed can be transferred onto the uppermost position of the sheets S in the sheet stacking means 3 even during sheet feeding.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine or a laser beam printer, and more specifically, the present invention relates to a sheet feeding device used in an image forming apparatus such as a copying machine or a laser beam printer. This invention relates to a feeding device.

(B) Conventional technology Conventionally, in a sheet feeding device that sequentially feeds sheets stacked on a sheet stacking means (hereinafter referred to as a paper feeding tray) one by one from the bottom, printing productivity has been improved. In order to increase the number of sheets, the applicant has devised a system in which sheets can be added from above while the sheets are being fed. In this sheet feeding device, the weight of the weight is such that the gap between the sheet and the sheet narrows as it goes toward the sheet insertion direction in the paper feeding tray, which presses the sheet feeding roller. When replenishing sheets, by inserting new sheets between the already loaded sheets and weights,
The weight is pushed up by new sheets as needed, so that the paper feed tray can be constantly fed.

(c) Problems to be Solved by the Invention However, in the above-described sheet feeding device, when a new sheet is to be added on top of a remaining sheet, the new sheet is moved over the previous sheet. However, when replenishing a new sheet onto the paper feed tray when there are no sheets at all, the high frictional resistance between the feed roller and the lowest sheet prevents replenishment. Not only is the leading edge of the sheet damaged, causing problems such as curling, which impedes sheet feeding, separation, etc., and causes jams.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a sheet feeding device that can easily load sheets onto a sheet loading means even when no sheets are loaded on the sheet loading means. be.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, when shown with reference to FIGS.
a sheet loading means (3) for loading the sheets (S); a feeding rotary body (5) for feeding the sheets (S) loaded on the sheet loading means (3) from below; ), a sheet feeding device W (1) comprising a sheet presence/absence detection means (36) for detecting the presence or absence of sheets (S) stacked on (5)
an actuation value WA for separating the feed rotary body (5) from the lowermost surface of the sea +18;
Actuation means (10) movable between two positions A and B with
The actuating means (10) is placed in the actuating position A when the sheet presence/absence detecting means (36) issues a no-paper signal, and the actuating means (10) is placed in the actuating position (X) when the no-paper signal is issued.
O) are moved to the retracted position B, respectively.

(E) Effect Based on the above configuration, when a sheet absence signal is issued from the sheet presence/absence detection means (36) in the sheet loading state in the sheet loading means (3)l, the activation means (10
) is located at the operating position A, and the sheet (S) to be inserted into the sheet stacking means (3) is separated from the feeding means (5). S) is inserted smoothly. Further, when the sheet presence signal is issued, the actuating means (10) retreats to the retracted position B and becomes ready to feed, and even during feeding, the sheets (S) to be replenished are kept at the sheet stacking means (3). ) can be loaded on top of the sheet (S).

Note that the above-mentioned symbols in parentheses are used to refer to the drawings, and do not limit the structure of the present invention in any way.

(F) Example A first example of the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, a sheet feeding device W1 has a paper feeding tray (sheet stacking means) 3 on which a plurality of sheets S are stacked,
A pair of regulating plates 31a and 31b are respectively disposed on the paper feed tray 3 to regulate the width direction of the sheets S and align the widths of the sheets S. A pinion 32 is rotatably mounted on the back side of the paper feed tray 3, and a pair of racks 33, 35 are engaged with opposing positions on the circumferential surface of the pinion 32. The racks 33 and 35 are supported so as to be slidable in the width direction of the paper feed tray 3, and the regulation plate 3
1a and 31b, respectively. This results in
The regulating plates 31a and 31b are movable in conjunction with each other.

A sheet presence/absence sensor 36 (sheet presence/absence detection means) for detecting the upper sheet S is disposed on the back side of the paper feed tray 3, and this sheet presence/absence sensor 36 rotates depending on the presence or absence of the sheet S. It consists of a sensor lever 36a and a photointerference 36b which is turned ON10FF by the sensor lever 36a.

A plurality of feeding belts (feeding rotary bodies) 5 are disposed downstream of the sheet presence/absence sensor 36. They are each wound around a driven roller 42 provided on a shaft 41, and are rotatable counterclockwise in the figure. Both shafts 39 and 41 are rotatably supported by a pair of left and right support plates 43, and the support plates 43 are rotatable about the drive shaft 39. Furthermore, the support plate 43
For example, the paper feed tray 3 is supported by being biased upward by the elasticity of a leaf spring (not shown) whose base is fixed to the sheet feed tray 3, and is further urged downward by the flange 46 provided on the bottom plate of the sheet feeding device 1. Movement is regulated.

A belt 47 is constructed from the above-mentioned feeding belt 5, both rollers 40, 42, etc. to the belt unit 1, and the belt unit 47 is arranged in a direction perpendicular to the conveyance direction of the sheet S,
That is, they are arranged at a plurality of locations in the width direction of the sheet feeding device 1.

A weight (pressing member) 6 is disposed above the paper feed tray 3, and a pin 5o fixed to the front end (left end in the figure) of the weight 6 is connected to an arc-shaped pin 5o formed on a pair of left and right side plates 51, respectively. It passes through the hole 51a and extends outside the side plate 51. The bins 50 are each fixed to the free ends of a pair of arms (not shown) whose bases are pivotally attached to both side plates 51.
Thereby, the weight 6 is configured to move up and down along the hole 51a.

A leading edge regulating member 52 that regulates the leading edge of the sheet S on the paper feed tray 3 is disposed near the downstream side of the weight 6 . The lower end of this tip regulating member 52 and the feeding belt 5 are separated by a predetermined distance, and the sheet S
It is now possible to feed.

A separation roller 7 that rotates in the opposite direction to the feeding direction of the sheet S is disposed downstream of the side plate 51, and this separation roller 7 is operated by a spring (not shown) attached to a fixed shaft 9. Due to its elasticity, the separation roller 7 is attached to the feed belt 5.
is pressed against.

?On the downstream side of the separation roller 7? A transport roller pair 57 consisting of guide members 55, 56 for guiding the toe S and a pinch row 57b in pressure contact with a drive roller 57a is sequentially arranged.

The sheet feeding device 1 has a plurality of connecting rods 59 at the front, and by connecting or detaching the connecting rods 59 to an image forming device 2 such as a laser beam printer, the sheet feeding device 1 can perform image forming. It can be attached to and detached from the device 2 at will. When installed in either the sheet feeding device 1 or the image forming device 2, the pair of conveying rollers 57 is in a state opposite to the manual sheet feeding port 2a formed in the image forming device 2.

Further, on the back side of the paper feed tray 3, an intermediate portion of an actuating member (actuating means) 10 is pivotally attached to a shaft 60, and one end (lower end in the figure) of the actuating member (actuating means) is connected to a solenoid 11 via a link 61. ing.

This actuating member 10 has both ends connected to the actuating member 10 and the hook 62.
The actuating member 10 is biased clockwise in the figure by the elasticity of the tension springs 63 that are respectively engaged with the actuating member 10, and its rotation is restricted by engaging the lower end of the actuating member 10 with the stopper 65.

An operating end (upper end in the figure) 1 which is the other end of the operating member 10
0a means that the solenoid 11 is OFF and the operating member 10 is OFF.
When the lower end of the belt unit 47 is in contact with the stopper 65, the belt unit 47 in the free state is in a state of protruding above the feeding belt 5 (operating position A). In this state, the way 1 to 6 is lifted by the operating end 10a of the operating member 10 and is separated from the feed belt 5.

In the above configuration, first, the action of inserting (replenishing) the sheet S into the paper feed tray 3 from the sheet-less state is controlled by the first
This will be explained with reference to the drawings and FIG.

The leading edge Sa of the sheet S inserted into the paper feed tray 3 moves in one direction along the inclined portion 10b formed at the top of the actuating member 10, and moves inward while lifting the weight 6. When the sheet S is further pushed in as shown in Figure 2,
When the sensor lever 36a is lowered by the tip Sa, a signal indicating that a sheet is present is generated from the photo interrupter 36b.

Next, the CPU (not shown) that receives the seat presence signal outputs an activation signal to the solenoid 11, and the activation member 10 rotates counterclockwise in the figure as shown in FIG. 3 to the retracted position. The leading edge Sa of the sheet S is moved to the belt unit 4.
7 is brought into contact with the feeding belt 5, and its upper surface is pressed and urged by the weight 6.

When a paper feed signal is sent from the image forming device (printer main body) 2 to the sheet feeding device 1 in this state, a drive motor (not shown) is rotated, and the driving force of this drive motor is used to feed the sheet via the drive roller 40. The rotation is transmitted to the belt 5, separation roller 7, and drive roller 57a, and the rotation of the drive roller 57a causes the pinch roller 57b to rotate as well.

Since the leading end of the sheet S is pressed against the feeding belt 5 by the weight 6 and the friction between the sheet S and the feeding belt 5 is increased, the conveying force of the feeding belt 5 is increased. In this state, as the feeding belt 5 rotates counterclockwise in the figure, the stacked sheets S are fed out from below, and separated one by one by the separation roller 7, leaving only the lowest sheet S. It is fed to a pair of transport rollers 57.

The sheet S fed by the pair of transport rollers 57 is transported into the image forming apparatus 2 from the manual paper feed port 2a of the image forming apparatus 2, and is further transported to a paper feed disposed downstream of the manual paper feed port 2a. The paper is fed to the image forming section of the image forming apparatus 2 by rollers (path shown).

Eventually, when all the sheets S on the paper feed tray 3 have been fed, the sensor lever 36a rotates clockwise and returns, causing the photo ink printer 36b to issue a no-sheet signal and receiving this signal. The CPU issues a solenoid OFF command to the solenoid 11, and the operating member 10 returns to the state shown in FIG.

FIG. 5 shows a block diagram of control of the sheet feeding device 1. As shown in FIG. In the figure, a CPU control unit 102 includes a microprocessor, a ROM storing a control program, a RAM storing data, etc., and a gate element.

A motor 105 that drives the feed belt 5 and a pair of conveyor rollers 57 is connected to the output boat of the control unit 102 via a motor driver 103, and a solenoid 11 that drives the actuating member 10 is connected via a driver 106. There is. Further, a sheet presence/absence sensor 36 for detecting the presence or absence of a sheet in the sheet feeding apparatus 1 is connected to the input port of the control unit 1202 via an input circuit 107 . Further, the sheet feeding device 1 and the main body of the image forming apparatus (printer) 2 are electrically connected by a power line and a signal line, and receive and receive power from the printer main body to send and receive signals.

The operation of the sheet feeding device 1 of this embodiment is shown in FIGS. 6 and 7.
This will be explained along the flowchart in the figure.

First, the sheet S is inserted into the sheet feeding device 1 (St
epl), and the paper feed signal is output (5tep3
), after detecting the sheet S, after one standby at a predetermined timing (Step not shown), the solenoid 11 is turned on/off.
Feed the sheet S.

Next, when all the sheets S are fed, the sheet presence/absence sensor 36 outputs a no-sheet signal (Stepl), and after timing t3, the motor 105 is turned off.
Step 6) Solenoid 1 after timing t4
1 to 0FFL/ (Step 7), the actuating member 10 is moved to a position above the feeding belt 5, and the seat S becomes ready for receiving three people.

8 to 10 respectively show a second embodiment of the present invention.

In the figure, a sheet feeding device 201 includes a sheet feeding tray (sheet loading means) 202 on which sheets S are stacked;
02, and this paper feed tray 202 has sheets S
A sheet presence/absence sensor (sheet presence/absence detection means) 203 is provided to detect the presence or absence of the sheet. This sheet presence sensor 2
03 is a sensor lever 20 that rotates in contact with the seat S.
5 and the photointerface that is turned on and off by this.

206.

A plurality of feeding belts (feeding means) 207 are disposed on both sides of the sheet presence/absence sensor 203 to feed the sheets S loaded on the sheet presence/absence sensor 203 from below, and a drive pulley 209 It is stretched around a driven pulley 210 and is rotatable. A weight (pressing member) 211 is disposed above the feeding belt 207, and the pressing member 211 pushes a pin 214 fixed thereto into an arcuate shape formed on a pair of side plates 212. It can be raised and lowered (swung) by being guided by the hole 213.

In the vicinity of the pressing member 211, there is a leading edge regulating member 2 that regulates the leading edge of the sheets S stacked on the paper feed tray 202.
15 are arranged. The lower end of the leading end regulating member 215 and the feeding belt 207 are separated by a predetermined distance, and the sheet S can be fed from this separated portion. A separation pad 216 made of a high-friction material such as rubber is fixedly installed on the downstream side of the tip regulating member 215, and this separation pad 216 is spaced a predetermined distance from the feeding belt 207. It is inclined at a predetermined angle with respect to the feeding direction.

An actuating member (actuating means) 15 is rotatably disposed near the inside or outside of the plurality of feed belts 207 by a shaft 217, and its upper end, the actuating end 15a, extends upward from the feed belt 207. It is extending. The lower end 15b of the actuating member 15 faces near the photointerrupter 219. The actuating portion 5 member 15 is biased counterclockwise at both ends by the elasticity of a tension spring 22o that is locked to the actuating member 15 and the main body of the sheet feeding device 201, respectively, and its lower edge is attached to the eccentric cam 221. The eccentric cam 221 is in pressure contact with the circumferential surface, and is fixed to a rotatably provided shaft 222.

When the operating end 15a of the operating member 15 is in pressure contact with the large diameter portion of the eccentric cam 221, it extends upward from the feeding belt 207 as shown in FIG. When pressed against the small diameter part, the operating end 15
a is sunk below the feed belt 207.

In FIG. 10, a gear 226 is fixedly connected via a one-way clutch 225 to a drive shaft 223 to which a drive pulley 209 for driving a feed belt 207 is fixed.
The rotation of the gear 226 transmits the rotational force to the drive shaft 223 only when rotating in the direction of an arrow 227. Gear 226 meshes with drive gear 231 of motor 230 via idle gear 229.

6 In addition, the shaft 22 to which the eccentric cam 221 is attached
2, a gear 233 is connected via a one-way clutch 232.
is arranged, and the rotational force of this gear 23.3 is as shown by arrow 2.
Only the rotational force of 35 is transmitted to the shaft 222. This gear 233 meshes with a drive gear 231 of the motor 230 via an idle gear 236. The actuating member 15 is at the lowest position (the position where the actuating end 15a is lowered)
is the home position, and in this position, the lower end 15b of the actuating member 15 is in a state of blocking the optical path of the photointerrupter 219.

In the above-described configuration, when the sheet presence/absence sensor 203 detects that there is no sheet on the paper feed tray 202, the motor (pulse motor in this embodiment) is rotated by a certain angle clockwise (in the direction of the dashed arrow). As a result, the eccentric cam 221 rotates so that the large diameter portion is located at the upper position. Due to this rotation, the actuating member 15 is located in the actuating portion WA with the actuating end 15a extending beyond the feeding belt 207 as shown in FIG. keep it away from.

Next, the sheet S is placed between the pressing member 211 and the actuating member 15.
When the sheet is inserted and pushed to the position of the leading end regulating member 215, the sensor lever 205 is pushed down by the sheet S, and the sheet presence/absence sensor 203 detects the presence of the sheet.

Upon detection of the presence of a sheet, the motor 230 further rotates in the direction of the dashed arrow to rotate the eccentric cam 221 to the home position. Following this rotation, the operating end 15a of the operating member 15 moves to the retracted position B (see FIG. 9) where it is sunk below the feed belt 207.

For the first time, the bottom surface of the sheet S is detected by the sheet presence/absence sensor 2.
03 and is upwardly pressed and urged by the pressing member 211, thereby becoming ready for feeding. In addition, motor 2
When the belt 30 rotates in the direction of the broken line arrow, no drive is transmitted to the feed belt 207 due to the action of the one-way clutch 225.

Next, when a paper feed signal is applied to the side plate 212 and the motor 230 rotates in the direction of the solid line arrow, the feed belt 2
07 rotates counterclockwise in FIG. 9 to feed the lowest sheet S of the stacked sheets S. Note that while the motor 230 is rotating in the direction of the solid arrow, the drive is not transmitted to the eccentric cam 221 due to the action of the one-way clutch 232, and the eccentric cam 221 is held at the same position. Eventually, when the sheet S on the paper feed tray 202 runs out, the sheet presence/absence sensor 203 detects that there is no sheet, and the actuating member 15 is positioned at the actuating position A, so that the sheet can be inserted.

The sheets S fed by the feeding belt 207 are separated one by one by a separation pad 216 and fed, and the sheets S sent out from the sheet feeding device 201 are further transferred to the next conveying roller, for example, as shown in FIG. The image is transferred to a conveyance roller 237 in the image forming apparatus (printer main body) 2 shown in FIG.

In this embodiment, unlike the first embodiment, the solenoid 11 for operating the actuating member 1o is not provided, and the actuating member 15 is moved to the repositions A and B by controlling the rotation direction of the pulse motor 230. is possible.

FIG. 11 shows a block diagram of the control section in this embodiment.

In the figure, a control unit 302 is composed of a microprocessor, a ROM that stores a control program, a RAM that stores data, etc., and a gate element. A motor (pulse motor) 230 that drives the feed belt 207 is connected to the output boat of the control unit 302 via a driver 303 . In addition, the input port of the control unit 302 has the following information:
The seat presence/absence sensor 203 and the photo interrupter (home position sensor) 219 are connected to the input circuit 305.30.
They are connected to each other via 6. Also, image forming apparatus (
The printer main body) 2 supplies power and sends and receives signals.

The operation of this embodiment is explained in the flowchart of FIG.
This will be explained using the timing chart shown in FIG.

First, when the paper feed signal is output from the printer main body 2 (Step O), and the sheet S is inserted into the sheet feeding device 201 (Step 8), the sheet 1
~ After timing t5 after S detection, the motor 230
rotates and drives in the CW force direction until the home position sensor 219 turns ON (Step 9).

Next, the motor 230 rotates in the CCW direction for a certain period of time T (constant pulse), then rotates according to a predetermined timing chart, and is driven again for a certain period of time T1. Repeat the pause and move to sheet S.
Continuous feeding is performed (StepH). Eventually, when the sheet S on the paper feed tray 202 runs out and the sheet presence/absence sensor 203 turns off (Step 8), the motor 2
30 is rotated in the CW force direction for a fixed time T2 (fixed pulse) and then stopped (Steps 3 and 14).

(G) As described in detail, according to the present invention, the operating position A above the sheet contact surface of the sheet stacking means and the retraction value 1 below.
A movable actuating means is provided in two positions, iB, and the actuating means is moved to the evacuation value IB in response to the sheet presence signal from the sheet presence/absence sensor to enable sheet feeding, and also allows sheet replenishment even during sheet feeding. By making it possible to move the actuating means to the actuating position A based on the sheet absence signal from the sheet presence/absence sensor, the sheet 1 inserted into the sheet loading means can be easily loaded without coming into contact with the feeding means. This not only improves operability when replenishing sheets, but also prevents problems such as paper feeding failures and double feeding due to curling or folding of the bottom sheet when inserting sheets. .

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of a sheet 1 to a feeding device during sheet insertion, showing a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view of the sheet feeding device after sheet feeding, and FIG. Figure 3 is a longitudinal cross-sectional side view of the sheet feeding device that is also ready for feeding.
5 is a block diagram of the control section, FIG. 6 is a flowchart, FIG. 7 is a timing chart, and FIG. 8 is a sheet feeding device showing a second embodiment of the present invention. 9 is a longitudinal side view of the same, and FIG.
FIG. 10 is a side view showing the drive system, FIG. 211 is a block diagram, FIG. 12 is a flowchart, and FIG. 13 is a timing chart. S... Seat A... Operating position, B...
Retracted position, 1,201... Sheet feeding device 3.
202.2...Printer main body (image forming device)
3,202...Paper feed tray (sheet loading means)
5,207... Feeding belt (feeding rotating body)
6,211... Weight (pressing member)
36,203... Sheet presence/absence detection sensor (sheet presence/absence detection means) 10.15... Actuation member (actuation means) 11... Solenoid, 105,2
30...Motor (pulse motor) 219...
・Photo interrupter (home position sensor)

Claims (1)

[Claims] 1. A sheet stacking means for stacking a plurality of sheets, a feeding rotary body for feeding the sheets stacked on the sheet stacking means from below, and sheets stacked on the sheet stacking means A sheet feeding apparatus comprising: a sheet presence/absence detection means for detecting the presence or absence of a sheet, an operating position A for separating the lowermost surface of the sheet from the feeding rotary body; and an abutment between the feeding rotary body and the sheet lowermost surface. two positions A and a retracted position B below the plane;
B, the actuating means is moved to an actuating position A when a paper out signal is issued from the sheet presence/absence detecting means, and the actuating means is moved to an operating position A when a paper out signal is issued. A sheet feeding device characterized by moving each sheet to a position B.