JPH0146411B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device used in an electrophotographic copying machine, a facsimile communication device, etc., in which a sheet on a mounting plate is pressed against a feeding member such as a paper feeding roller each time the sheet is fed. The present invention relates to a paper feeding device that feeds paper in a continuous manner.

Conventionally, in the paper feeding section of an electrophotographic copying machine, the automatic document feeding device of the same copying machine, the document feeding device of a facsimile transmitter, etc., recording paper or originals are placed on a placement plate, and this placement plate is used for feeding. Many paper feeding devices are used in which recording paper or the like is fed one sheet at a time by being moved to a feeding member such as a paper roller, and the uppermost sheet is brought into pressure contact with the feeding member.

By the way, in such a conventional paper feeding device, a feeding member such as a paper feeding roller is always kept in a drive ready state, and paper feeding is started by pressing a sheet on a placement plate against this feeding member. It is normal to have However, according to this method of starting paper feeding, the recording paper, etc. and the feeding member often do not come into complete pressure contact, causing so-called one-sided contact, and the recording paper, etc. is fed in one direction, resulting in this one-sided paper feeding. This can cause jamming and contribute to the formation of one-sided images.
For this reason, conventional measures have been taken in which a detector is provided to detect the lifting of the placement plate, a delay timer is set based on the detection signal of this detector, and the paper feed roller is rotated by the operation of this delay timer. ing. However, this measure requires an expensive detector and a delay timer, and in order to allow time for the mounting plate to stabilize, a considerable amount of wasted time is generated before the recording paper or the like is actually fed.

In order to solve the conventional problems as described above, the present invention is capable of starting paper feeding immediately after a paper feeding start command is given without wasting time without using an expensive detector or delay timer. This paper proposes a paper feeding device that can

Embodiments of the invention will now be described in detail with reference to the drawings.

The illustrated example is an embodiment in which the present invention is applied to a paper feed section of an electrophotographic copying machine. can be inserted. As shown in FIG. 4, the paper feed cassette 4 has a built-in bottom plate 5, that is, a mounting plate, on which a plurality of sheets, that is, recording papers X are placed in a stacked state. Can be done.

In FIG. 1, a fulcrum shaft 8 mounted on a side frame 7 is located at the bottom of the paper feed table 2, and the base of a flip-up member 9 is fixed to the center of the fulcrum shaft 8. This flip-up member 9 is the opening part 1 of the paper feed tray 2.
0 and the escape hole 11 of the paper feed cassette 4 (as shown in the fourth figure)
It leaks into the paper feed cassette 4 through the paper feed cassette 4 and flips up the bottom plate 5. A detector for sensing the recording paper X on the bottom plate 5 is provided near the tip of the flip-up member 9. For this purpose, a through hole 12 is made in a part of the bottom plate.
A light emitting element 13 and a phototransistor 14 whose irradiation field and light receiving field are directed toward the through hole 12 are fixed to the tip of the flip-up member 9 corresponding to the above.
Therefore, when the bottom plate 5 is lifted up as shown in the fourth figure, the recording paper The existence of X can be confirmed. As shown in FIGS. 2 and 5, a driven lever 16 biased by a tension spring 15 is fixed to the shaft end of the fulcrum shaft 8, and the attitude of this driven lever 16 is controlled by a control unit to be described later. .

Returning to FIG. 1, a paper feed unit 18 is located inside and above the paper feed table 2 for feeding the recording sheets X in the paper feed cassette 4 into the paper feed path 17 one by one.

This paper feeding unit 18 is assembled to a parallel belt drive shaft 19 and a roller drive shaft 20 which are installed between the side frames 7, and includes a drive pulley 21 fixed to the belt drive shaft 19 and a roller drive shaft 20. A conveyor belt 23 is provided, which is stretched between a driven pulley 22 loosely fitted to a drive shaft 20. A paper feed roller 24 is fixed to the roller drive shaft 20, to which the recording paper X in the paper feed cassette 4 is pressed. Further, a peeling member 26 fixedly supported by the mounting plate 25 is slidably contacted on the surface of the conveyor belt 23 . Therefore, when the bottom plate 5 of the paper feed cassette 4 is lifted up, the recording paper X in the paper feed cassette 4 is fed out by the rotational movement of the paper feed roller 24.
These recording sheets X are moved toward the paper feed path 17 by the movement of the conveyor belt 23 . Then, due to the presence of the peeling member 26, the uppermost recording paper is peeled off from the other recording papers, and only the uppermost recording paper is left in the paper feed path.
It will be sent out on the 7th.

2 and 3 show the driven lever 1 described above.
6 shows a control unit 27 that controls the belt drive shaft 19 and the roller drive shaft 20, and this control unit 27 receives driving force from a drive gear 28. That is, the drive gear 28 has an input gear 30, a relay gear 31, and a first output gear 32 that are loosely fitted to the belt drive shaft 19, the support shaft 29 provided upright on the side frame 7, and the roller drive shaft 20, respectively. It is constantly rotating. An electromagnetic clutch 33 is attached to the belt drive shaft 19 and is energized by a paper feed start command signal given from the main body of the electrophotographic copying machine. When the electromagnetic clutch 33 is energized, the belt is driven from the input gear 30. Driving force is transmitted to the shaft 19. Further, a second shaft is provided at the shaft end of the belt drive shaft 19.
An output gear 34 is fixed, and this second output gear 34
rotates the driven gear 35 loosely fitted onto the support shaft 29.

On the other hand, the support shaft 29 has the driven lever 16
The base of a restraining member 36 that operates the is loosely fitted, and rotational force is transmitted from the second output gear 34 to this restraining member 36 via a spring clutch 37.

As shown in FIG. 2, the restraining member 36 has two arms 36a and 36b, and a strong tension spring 39, one end of which is hooked to a pin 38 of the side frame 7, is hooked to the arm 36a.

Further, the other arm 36b is applied to the roller 40 of the driven lever 16 described above. Therefore, in the demagnetized state of the electromagnetic clutch 33, the driven lever 16 is pushed down by the restraining member 36 as shown in the second figure against the force of the tension spring 15, and the flip-up member 9 is pushed down as shown in the first figure. It is lowered to the bottom of the paper table 2.

The spring clutch 37 has a sleeve 41 with a projection 41a, and a stopper 4 fixed to the side frame 7 is located in the movement range of the projection 41a.
2 is coming. Therefore, when the driven gear 35 is rotated by the second output gear 34 due to the excitation of the electromagnetic clutch 33, the arm 36b of the restraining member 36 is retreated out of the movement range of the driven lever 16, as shown in FIG. However, in this retreated state, the protrusion 41a
Since this hits the stopper 42, the rotational movement of the driven gear 35 is no longer applied to the restraining member 36, and the restraining member 36 is held in this retracted position.

A latch member 43 is loosely fitted to the support shaft 29.
The base of the latch member 43 is supported, and a spring 44 shown in FIG. 3 is provided between the latch member 43 and the restraining member 36. This latch member 43 has an engaging piece 4 that can be engaged with the side surface of the arm 36b of the restraining member 36.
5, and this engagement piece 45 is always seated on the arm 36b by the force of the spring 44. This latch member 43 is therefore driven by the movement of the restraining member 36.

Meanwhile, a spring clutch 46 is interposed between the first output gear 32 and the roller drive shaft 20, and a plurality of teeth 48 are formed on the circumferential surface of a sleeve 47 of the spring clutch 46. Within the range of motion of these teeth 48 are latches 43 which engage the teeth 48 to prevent rotation of the roller drive shaft 20 when the restraining member 36 is in the second illustrated rotational position.
A is facing me. Therefore, when the restraining member 36 is in the rotational position in which the driven lever 16 is released as shown in FIG. will be done.

Since the apparatus of the embodiment has the above-described configuration, when there is no sheet feeding start command signal, the driven lever 16 is pushed down to the position shown in the second figure by the restraining member 36, and the spring lifting member 9 is moved to the second position. 1. Place it in the lowered position as shown. Therefore, in this state, the paper feed cassette 4 can be freely inserted into and removed from the paper feed tray 2, and this operation can be easily performed by simply holding the paper feed cassette 4.

Next, when a paper feed start command signal is applied from the main body of the electrophotographic copying machine, the electromagnetic clutch 33 is energized. Therefore, rotational motion is transmitted from the input gear 30 that is constantly rotating in the drive gear 28 to the belt drive shaft 19, and the drive pulley 21 transfers rotational motion to the conveyor belt 2.
3 is driven. At the same time, belt drive shaft 1
The second output gear 34 of No. 9 is rotated, and the restraining member 36 is rotated in the direction of the arrow in FIG. is rotated. Therefore, the driven lever 16 is lifted up by the force of the tension spring 15 toward the position shown in FIG.
The flip-up member 9 flips up the bottom plate 5 of the paper feed cassette 4 as shown in the fourth figure.

As described above, when the recording paper X in the paper feed cassette 4 is pressed against the paper feed roller 24, the sleeve 4
Since the protrusion 41a of 1 collides with the stopper 42,
The spring clutch 37 opens and the restraining member 36
are held in the same position. Then, the latch 43a of the clutch member 43 driven by the restraining member 36 is disengaged from the teeth 48 of the spring clutch 46. Therefore, the rotational motion of the first output gear 32, which is constantly rotating, is transmitted to the roller drive shaft 20 via the spring clutch 46, and the paper feed roller 24 starts rotating. As a result, the recording paper X in the paper feed cassette 4 is fed out by the paper feed roller 24, and the uppermost recording paper X is sent out to the paper feed path 17 one by one.

When the required number of sheets of recording paper has been fed, the paper feed start signal is no longer transmitted and the electromagnetic clutch 33
is demagnetized. Therefore, since the rotational force of the driven gear 35 is eliminated, the force of the tension spring 39 returns the restraining member 36 and the driven lever 16 to the position shown in the second figure. Therefore, the flip-up member 9 returns to the position shown in the first figure, and the paper feed cassette 4 can be freely pulled out from the paper feed tray 2. The latch 43a engages with the teeth 48 of the spring clutch 46, so that the paper feed roller 24 stops. As a result, the paper feed cassette 4
You can now freely replace the

In the above embodiments, the present invention was applied to the paper feeding section of an electrophotographic copying machine, but the present invention is applicable to, for example, an automatic document feeding device of an electrophotographic copying machine, a document feeder of a facsimile transmitter, etc. It is obvious that the present invention can also be applied to devices, etc.

As is clear from the above description, according to the present invention, the sheet loading plate is first lifted up by the sheet feeding start command signal, and immediately after the pressure contact between the feeding member and the sheet is stabilized, sheet feeding starts immediately. be done. Therefore, the wasted time at the start of paper feeding is shortened, and the troublesome adjustment and operation required to press the sheet on the loading plate and the feeding member are no longer required, making it easy to handle and easy to use. This has the effect that it is possible to obtain a paper feeding device in which orientational paper feeding is less likely to occur, and that the paper feeding speed can also be improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the paper feed section of an electrophotographic copying machine to which the present invention is applied, FIG. 2 is a side view of the paper feed section, and FIG. 3 is a cross-sectional view taken along the line - in FIG. FIG. 4 is a diagram corresponding to FIG. 1 at the time of paper feeding, and FIG. 5 is a diagram corresponding to FIG. 2 at the time of paper feeding. X...Recording paper (sheet), 2...Paper feed stand, 5...
...Bottom plate (placing plate), 9...Flip-up member, 24...
...paper feed roller (feeding member), 33... electromagnetic clutch, 36... restraining member, 43... latch member.

Claims (1)

[Scope of Claims] 1. A rotatable sheet placement plate is provided in a paper feed cassette containing sheets in a stacked state, and a rotatable sheet placement plate is provided on the opposite side of the sheet across the placement plate, and a flip-up member rotatable between a flip-up position for flipping up the plate and an initial position for not flipping up the mounting plate; A flip-up member biasing member having one end fixed to the flip-up member and the other end fixed to the paper feeder main body side, and a locking member for locking the flip-up operation of the flip-up member, the locking member being a restraining member for the flip-up member that rotates from a locking position where the flip-up member is locked to an open position where the lock is released; and a restraining member biasing means having one end fixed to the restraining member and the other end fixed to the sheet feeding device main body side so as to lock the flip-up member, and in an initial state where sheet feeding is not started, the restraining member biasing means The locking member is configured to lock the flip-up member against the bias force of the flip-up member bias means by the bias force of the member bias unit, and the locking member is configured to lock the flip-up member by a sheet feeding start signal. a driving means for rotating the restraining member from a locking position to a release position; a holding means for the restraining member that holds the restraining member in the open position and releases the holding when the paper feed signal is no longer received; Therefore, it has a sheet feeding member that starts feeding the sheet on the placement plate to the next process and stops feeding when the paper feeding signal is lost, and when the feeding start signal is input, the driving means The restraining member rotates against the biasing force of the restraining member biasing means, and the mounting plate is flipped up as the flip-up member is rotated by the biasing force of the flip-up member biasing means. When the paper feed start signal is no longer input, the locking member rotates together with the flip-up member due to the biasing force of the suppressing member biasing means, so that the initial stage in which paper feeding is not started is caused. A paper feeding device characterized in that it returns to its original state.