JP2751486B2 - Paper feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet supply apparatus which operates by receiving a driving force from a driving source of a printer and transfers cut sheets one by one to a platen of the printer.

2. Description of the Related Art Conventionally, as one of the cut sheet feeding devices, a sheet feed roller that separates cut sheets stored in a hopper one by one and sends the separated sheet to a platen direction, and a sheet feed roller and a platen. The one provided with an auxiliary roller disposed between the auxiliary rollers for transporting the cut sheet fed by the paper feed roller to the platen, and a gear mechanism for transmitting the rotation of the platen rotationally driven by the paper feed motor to the two rollers. Are known.

In this type of apparatus, as shown in, for example, JP-A-63-288833, when the platen rotates, the auxiliary roller rotates in the paper feed direction regardless of the rotation direction, but the paper feed roller rotates in the reverse direction of the platen. It rotates in the paper feed direction only during rotation, and does not transmit rotation of the platen during normal rotation. The cut sheet is transferred from the paper feed roller to the platen via the auxiliary roller by the reverse rotation of the platen. Then, when the cut sheet is pulled into the auxiliary roller, the platen rotates forward and is transported only by the auxiliary roller, and the cut sheet is drawn by a certain amount between the platen and the pinch roller. Next, the platen rotates in the reverse direction by an amount corresponding to the retracted amount, and the cut sheet is bent in combination with the urging of the auxiliary roller and the paper feed roller in the sheet feed direction. The front end in the direction is parallel to the axial direction of the platen axis on the platen surface. Then, the platen rotates forward, and the cut sheet is sandwiched between the platen and the pinch roller and sent to the printing unit of the printer along the periphery of the platen.

In this way, the front end of the cut sheet in the paper feed direction is corrected on the platen surface so as to be parallel to the axial direction of the platen shaft (hereinafter, referred to as the platen shaft)
(Referred to as skew correction), so that the sheet can be transported to a printing section and printed at an accurate position on a cut sheet.

[Problems to be Solved by the Invention] In the above apparatus, when the platen rotates forward, the rotation of the platen is not transmitted to the paper feed roller. And a bundle of cut sheets stacked on the hopper. Since the force of pressing the bundle of cut sheets by the paper feed roller is relatively strong, a load is applied to the feed of cut sheets by the auxiliary roller. For this reason, in the above-described apparatus, the auxiliary roller slips and the above-described appropriate bending cannot be performed, so that the cut sheet may skew or the front end of the cut sheet may not accurately reach the printing unit. .

Further, in the above device, the gear for the paper feed roller, outside the turning range of the planetary gear around the sun gear,
Since the gears for the auxiliary rollers must be arranged, there is a problem that the arrangement structure of the gear train becomes large, and the whole apparatus becomes large.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sheet feeding apparatus capable of reliably supplying cut sheets from a hopper to a platen and having a small size.

[Means for Solving the Problems] The gist of claim 1 of the present invention is that a cut sheet gist is attached to a printer, operates by receiving a driving force from a driving source of the printer, and outputs a cut summary to the platen of the printer one by one. A sheet supply device for transferring, and a hopper for stacking and storing cut sheet paper;
A paper feed roller that separates the stored cut sheets one by one and feeds the platen direction, and is arranged between the paper feed rollers and the platen, and transfers the cut sheet sent by the paper feed rollers to the platen. An auxiliary roller, a driving force transmitting mechanism for transmitting the driving force of the driving source to the auxiliary roller when the platen is rotating, so that the auxiliary roller is rotatable in the paper feeding direction, and a paper feeding roller for rotating the auxiliary roller. A rotation transmission mechanism for transmitting the paper feed roller rotatably in the paper feed direction;
By rotating the platen in a predetermined direction while the electromagnetic clutch is connected and interrupting the transmission of rotation by the rotation transmission mechanism, the paper feed roller and the auxiliary roller are rotated in the paper feed direction. Transporting the cut sheet in the hopper in the direction of the platen, and after the cut sheet is sandwiched between the pair of rollers downstream of the auxiliary roller by the transfer, the electromagnetic clutch is shut off, and the sheet feed roller And a control unit for stopping the rotation of the paper supply device.

According to a second aspect of the present invention, the roller pair includes the platen and a pinch roller disposed on a side of the platen. It is in the paper supply device.

[Operation] In the paper feeding apparatus according to the first aspect of the present invention configured as described above, when the platen rotates, the driving force transmission mechanism transmits the driving force of the driving source to the auxiliary roller, and the auxiliary roller is driven. The paper feed roller is always rotated in the paper feed direction, and the rotation transmission mechanism transmits the rotation of the auxiliary roller to the paper feed roller via the electromagnetic clutch, and always rotates the paper feed roller in the paper feed direction. Then, the control means rotates the auxiliary roller and the paper feed roller in the paper feed direction by rotating the platen in a predetermined direction while the electromagnetic clutch is connected, and transports the cut sheet in the hopper in the direction of the platen. At the same time, the cut sheet is caught by a pair of rollers (a pair of a platen and a pinch roller in the invention of claim 2) downstream of the auxiliary roller by the transfer, and then the electromagnetic clutch is disconnected to rotate the paper feed roller. Stop.

Example An example of the present invention will be described with reference to the drawings. Figure 1
FIG. 1 is a cross-sectional view of a cut sheet supply device and a printer to which the present invention has been applied.

As shown in the figure, inside the printer P, a platen 2 that is driven to rotate by a paper feed motor (not shown) that is a well-known stepping motor is rotatably supported by a printer frame 4. A first pinch roller 6a, a second pinch roller 6b, and a paper bale roller 6c are arranged on the outer periphery of the platen 2. Each of the rollers rotates following the rotation of the platen 2 and cooperates with the platen 2 to print the printing paper. The platen is transported along the outer peripheral surface. At the front front of the platen 2, a print head 8 for recording characters and figures on print paper is provided.
Above the platen 2, a cut sheet supply device 20 is mounted. The paper feed motor is controlled so as to move in synchronism with a pulse signal from a control device (not shown) for controlling the drive system and the electric signal system of the printer P. The configuration and operation of the control device Is well known as a control device of a printer, and the description is omitted.

In addition, a paper guide plate 10 for guiding the transported cut sheet PP along the outer peripheral surface of the platen 2 is disposed near the first pinch roller 6A. The photo sensor 12 for detecting that the predetermined position has been reached
It is fixed at. The photo sensor 12 is a reflection type photo sensor, which emits light through the respective transmission holes 10a and 14a provided in the paper guide plate 10 and the L bracket 14, and detects the arrival of the cut sheet PP by the presence or absence of reflected light. I do. The detection signal output from the photo sensor 12 is input to the control device. After receiving the detection signal, the control device counts the number of output pulses to the paper feed motor and counts a predetermined number PN, and then outputs a control signal to disconnect the electromagnetic clutch 72 described later.

The cut-sheet paper supply device 20 includes a hopper 22 for stacking and storing cut-sheet paper PP, a stacker 24 disposed opposite to the hopper 22 for storing cut-sheet paper PP discharged from the platen 2, and a hopper.
A frame 34 supporting the stacker 22 and the stacker 24 is provided in an extended shape on both left and right sides.
And a connecting arm 26 which can be attached to and detached from the main frame.

In the vicinity of the lower end of the hopper 22, there is provided a paper feed roller 28 for peeling off the cut sheet PP stored in the hopper 22 one by one and sending it out in the direction of the platen 2, downstream of the paper feed roller 28 in the paper feed direction. Cut paper PP sent from the paper feed roller 28
A pair of auxiliary rollers 30a and 30b for transferring the sheet to the platen 2 are provided. On the other hand, near the lower end of the stacker 24, a carry-out roller 32 for carrying out the cut sheet PP discharged from the platen 2 to the stacker 24 is provided. Each of these rollers 28,
30a, 30b, and 32 are a first gear mechanism 40 described later from the platen 2.
The power is transmitted via the second gear mechanism 60 and is rotated.

As shown in FIG. 2, a first gear mechanism 40 as a driving force transmission mechanism includes one of the frames 34 of the cut-sheet feeding device 20 disposed in a side frame 34a. When mounted on the shaft P, the gear meshes with a platen drive gear 42 fixed to the shaft 2a of the platen 2, and the driving force is applied to each of the rollers 28, 30.
a, tell 32.

The first gear mechanism 40 includes transmission gears 44a, 44b, and 44c that mesh with the platen drive gear 42 to transmit the rotation thereof, and a two-stage gear 46 that has a main gear 46a and a sub gear 46b that mesh with the transmission gear 44c. Idle gear 4 meshing with sub gear 46b
8 and two planetary gears connected to the sun gear 50a by the sun gear 50a meshing with the idle gear 48 and the swing arm 50b.
A planetary gear mechanism 50 composed of 50c and 50d, an auxiliary roller drive gear 52 fixed to one end of the shaft 30aa of the auxiliary roller 30a, an auxiliary idle gear 54 meshing with the auxiliary roller drive gear 52,
Two unloading idle gears 56a and 56b connected to the main gear 46a, and a shaft 32 of the unloading roller 32 meshing with the unloading idle 56b.
The discharge gear 58 fixed to a is constituted as a main part.

In the planetary gear mechanism 50, when the platen 2 rotates forward (rotation in the paper down direction and rotation in the direction of the solid line arrow in the figure), as shown by the solid line in the figure, the clockwise rotation of the sun gear 50a As the planetary gear 50d rotates, the auxiliary roller drive gear 5
2, when the platen 2 rotates in the reverse direction (rotation in the direction of the dashed arrow in the figure), the planetary gear 50c is rotated by the counterclockwise rotation of the sun gear 50a as shown by the broken line in the figure. By meshing with the gear 54, the auxiliary roller drive gear 52 is rotated only in the paper feeding direction (clockwise) regardless of whether the platen 2 rotates forward or backward.

As shown in FIG. 3, a second gear mechanism 60 as a rotation transmission mechanism is provided in the other side frame 34b of the frame 34.

The second gear mechanism 60 includes an auxiliary roller gear 62 fixed to the other end of the shaft 30aa of the auxiliary roller 30a, and a shaft 28 of the paper feed roller 28.
The paper feed roller drive gear 64 provided in a and the auxiliary roller 3
0b, an auxiliary roller driven gear 66 fixed to the shaft 30bb, a paper feed idle gear 68 meshing with the auxiliary roller gear 62 and the paper feed roller driving gear 64, and a transmission of the rotation of the auxiliary roller gear 62 to the auxiliary roller driven gear 66. And transmission gears 70a and 70b. Paper feed roller drive gear 64 and paper feed roller shaft 28a
, An electromagnetic clutch 72 is provided. Therefore, in synchronization with the rotation of one auxiliary roller 30a, the other auxiliary roller 30b rotates in the paper feed direction, and the coupling operation of the electromagnetic clutch 72 causes the paper feed roller drive gear 64 and the shaft to rotate.
The paper feed roller 28 rotates in the paper feed direction by rotating integrally with the sheet feed roller 28a. The electromagnetic clutch 72 is controlled to be connected and disconnected by a control signal from a control device as a control means. When the electromagnetic clutch 72 is disconnected, the paper feed roller drive gear 64 is freely rotatable with respect to the shaft 28a.

Also, as shown in FIG. 4, the shaft 30aa of the auxiliary roller 30a
The gap between the auxiliary roller 30b and the shaft 30bb is maintained at a predetermined equal interval by the rim member 80.

Next, an example of the operation of the cut sheet supply device will be described with reference to FIG. FIG. 5 is an explanatory diagram showing the timing of rotation of the paper feed motor in both forward and reverse directions.

As shown in the figure, first, when the paper feed motor is started by the forward rotation to rotate the platen 2 forward (t0), the paper feed motor is slowed down and reaches a predetermined speed (for example, 600 PPS) and then is operated at a constant speed. You. At this time, the auxiliary rollers 30a, 3
When 0b is rotated in the paper feed direction, the electromagnetic clutch 72 is connected and the paper feed roller 28 is rotated in the paper feed direction to transfer the cut sheet PP to the platen 2. When the front end of the cut sheet PP reaches the photo sensor 12 and the photo sensor 12 is turned on (t1), the paper feed motor starts a slowdown operation, moves down by a predetermined number of steps while being decelerated, and stops ( t2).
At this time, the front end of cut sheet PP is still platen 2 and first
It does not reach between the pinch roller 6a.

After an instantaneous stop, the paper feed motor is restarted in reverse rotation (t3), stops after a predetermined number of steps, and stops (t4). In this process, the platen 2 rotates in the reverse direction, the paper feed roller 28 and the auxiliary rollers 30a and 30b rotate in the normal direction, and the cut sheet PP moves between the platen 2 and the first pinch roller 6a in the reverse rotation. The skew correction is performed by abutting and bending the front end.

Then, after a short stop time, the paper feed motor is restarted by the forward rotation (t5), stops after moving up by a predetermined number of steps (t7). In this process, the platen 2 and the auxiliary rollers 30a and 30b rotate forward, and the cut sheet PP
From the first pinch roller 6a to the second pinch roller 6b. Immediately after this, that is, after the number of pulses output by the control device after the photo sensor 12 is turned on reaches the predetermined number PN, the electromagnetic clutch 72 is disconnected (t6). Therefore,
At this point, the paper feed roller 28 is turned off, and the cut sheet PP
While the platen 2 is firmly held between the platen 2 and the first and second pinch rollers 6a and 6b, the front end of the platen 2 is accurately fed to a position where printing is to be performed by the print head 8 and stopped.

As described above, in this embodiment, the rotation of the auxiliary roller 30a is transmitted to the paper feed roller 28 via the first and second gear mechanisms 40 and 60 and the electromagnetic clutch 72, and the cut sheet PP is transferred to the auxiliary roller 30a. , 30b, and after counting a predetermined number of pulses PN after the photo sensor 12 is turned on, the paper feed roller
In this embodiment, the cut sheet PP is composed of the platen 2 and the first and second pinch rollers 6a.
And 6b, the sheet is fed by the sheet feed roller 28. Therefore, the electromagnetic clutch 72
After the cutoff, even if the paper feed roller 28 becomes a load with respect to the paper feed, the cut sheet PP is reliably transferred to the print head 8 without the auxiliary rollers 30a and 30b slipping.

In addition, since the time during which the load is applied by the paper feed roller 28 is shortened, the paper supply to the printing device that is to be accurately printed by the print head 8 is more reliable.

In this embodiment, the rotation of the platen 2 is transmitted to one end of the auxiliary roller shaft 30aa, and the rotation is transmitted to the paper feed roller 28 from the other end of the coaxial 30aa. The configuration for adjusting the rotation direction becomes easy, and it is not necessary to arrange many gears around the sun gear as in the conventional case, and it is possible to disperse the gears on both side frames 34a, 34b of the frame 34. Can be made smaller.

Further, as described above, since the rotation of the paper feed roller 28 is transmitted from the auxiliary roller 30a, the platen 2
The rotation of the paper feed roller 28 is not stopped by the switching of the rotation direction, and after the cut sheet PP is securely fed toward the platen 2, the rotation of the paper feed roller 28 is stopped by the electromagnetic clutch 72. , It is possible to prohibit the subsequent paper from being sent.

When feeding short cut paper such as postcards, the number of pulses PN counted after the photo sensor 12 is turned on is adjusted so that the trailing end of the paper is
Immediately after passing, the electromagnetic clutch 72 is disconnected. By adjusting the cutoff timing of the electromagnetic clutch 72 in this way, the paper feed roller 28 does not continuously feed another succeeding sheet.

[Effects of the Invention] As described above, in the paper supply device of the first aspect of the present invention, when the platen rotates, the driving force transmission mechanism transmits the driving force of the driving source to the auxiliary roller, and Is always rotated in the paper feed direction, and the rotation transmitting mechanism transmits the rotation of the auxiliary roller to the paper feed roller via the electromagnetic clutch, and always rotates the paper feed roller in the paper feed direction. Then, the control means rotates the auxiliary roller and the paper feed roller in the paper feed direction by rotating the platen in a predetermined direction while the electromagnetic clutch is connected, and transports the cut sheet in the hopper in the direction of the platen. At the same time, the cut sheet is pinched by a pair of rollers (a pair of a platen and a pinch roller in the invention of claim 2) downstream of the auxiliary roller by the transfer, and then the electromagnetic clutch is disconnected to rotate the paper feed roller. To stop.

As described above, in the present invention (claims 1 and 2), when the platen rotates, the driving force is transmitted not only to the auxiliary roller but also to the paper feed roller, and the auxiliary roller and the paper feed roller feed the cut sheet. Therefore, the load on the auxiliary roller can be reduced.

Then, after the cut sheet is sandwiched between a pair of rollers downstream of the auxiliary roller (for example, a pair of a platen and a pinch roller), the electromagnetic clutch is shut off and the sheet feed roller is stopped. Can be reliably transferred.

Further, in the present invention, the driving force of the driving source is transmitted to the auxiliary roller by the driving force transmission mechanism, and further transmitted from the auxiliary roller to the paper feed roller by the rotation transmission mechanism. And the size of the whole can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a sheet feeding apparatus and a printer according to an embodiment, FIG. 2 is an explanatory view of a first gear mechanism, FIG. 3 is an explanatory view of a second gear mechanism, and FIG. FIG. 5 is an explanatory diagram showing the arrangement of the rollers, and FIG. 5 is an explanatory diagram showing the timing of rotation of the paper feed motor in both forward and reverse directions. 2 ... platen, 12 ... photo sensor 22 ... hopper, 28 ... paper feed rollers 30a, 30b ... auxiliary rollers 40 ... first gear mechanism (drive transmission mechanism) 60 ... second gear mechanism (rotation transmission) Mechanism) 72: Electromagnetic clutch, PP: Cut sheet

Claims (2)

(57) [Claims] 1. A sheet supply device mounted on a printer, receiving a driving force from a driving source of the printer, and operating to transfer cut sheets one by one to a platen of the printer. A paper feed roller that separates the stored cut sheets one by one and feeds the sheet in the direction of the platen; and a paper feed roller that is disposed between the paper feed roller and the platen and is sent by the paper feed roller. An auxiliary roller for transferring the cut cut sheet to the platen; and, when the platen is rotating, transmitting the driving force of the driving source to the auxiliary roller such that the auxiliary roller is rotatable in the paper feed direction. A driving force transmitting mechanism, a rotation transmitting mechanism for transmitting the rotation of the auxiliary roller to the paper feeding roller so that the paper feeding roller is rotatable in the paper feeding direction, and intermittently transmitting the rotation by the rotation transmitting mechanism. With the magnetic clutch and the electromagnetic clutch connected, by rotating the platen in a predetermined direction, the paper feed roller and the auxiliary roller are rotated in the paper feed direction, and the cut-sheet paper in the hopper is moved in the direction described above. Control means for transferring the cut sheet in the direction of the platen, and after the cut sheet is pinched by the pair of rollers downstream of the auxiliary roller, to shut off the electromagnetic clutch and stop the rotation of the paper feed roller. A paper supply device comprising: 2. The paper supply device according to claim 1, wherein the roller pair comprises: the platen; and a pinch roller disposed on a side of the platen.