JPS597610B2 - printer paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device for a printer that feeds continuous paper to a printing section and, after printing, cuts the continuous paper into an appropriate length using a cutter provided downstream of the printing section in the continuous paper feeding direction.

In dot printers and the like, in order to improve printing quality and reduce noise generated during printing, it is desirable that the continuous paper be brought into close contact with the platen of the printing section with appropriate tension.

For this reason, in conventional paper feeding devices, the circumferential speed of the pusher roller that pulls out the printed continuous paper from the printing section is slightly faster than the circumferential speed of the sprocket that feeds the continuous paper into the printing section. It is designed to provide a predetermined tension. Incidentally, in order to minimize the margins generated when continuous paper is set, a cutter for cutting the continuous paper is disposed near the printing section.

However, when the amount of margin setting is small like this,
Since setting continuous paper is troublesome, the leading edge of the continuous paper is usually passed through a cutter portion, and a considerable margin is set before setting the continuous paper, which results in a lot of waste and is uneconomical. It is also possible to minimize the margin by reversing the push roller in such a set state, but in the case of the conventional structure, it is not possible to apply appropriate tension to the continuous paper due to the difference in peripheral speed. On the contrary, the result is that the continuous paper is set in a loose state, which is undesirable. The present invention was developed under the above circumstances, and its purpose is to make it possible to easily set continuous paper by applying appropriate tension, and to reduce the margin when setting paper. An object of the present invention is to provide a paper feeding device for a printer. An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Symbol 1 is a platen, 2 is a printing head driven by a dot printing method, and a printing section is formed by these.

The platen 1 supports a paper guide 3 having a substantially semicircular shape, and another paper guide 4 having a substantially semicircular arc shape is disposed facing the paper guide 3 and slightly spaced therefrom. Note that the continuous paper A that is guided by the paper guides 3 and 4 and reaches the printing section is provided with engagement holes (Perf Orati) at intervals along the longitudinal direction of both side edges.
Onl (not shown). Then, on the paper feed side of the printing section, on the entrance side of the paper guides 3 and 4,
A feed sprocket 5 that can be rotated in forward and reverse directions is arranged.

The feeding sprocket 5 is a pin tractor, pin foil, or the like, and has an engaging protrusion 5a protruding from its circumferential surface that engages with an engaging hole in the continuous paper A to apply a conveyance force to the continuous paper A. . The feed sprocket 5 is attached to a support shaft 6 having a rectangular cross section. Further, a rotating body r that can rotate forward and backward is arranged on the paper feeding side of the printing section.

This rotating body 7 is a roller and is attached to a support shaft 8. The feed sprocket 5 and the rotating body 7 are driven to rotate in the same direction and in synchronization by a drive mechanism 9. To describe an example of the drive mechanism 9 in detail, 10 is a drive motor, and an output gear 11 attached to its output shaft is meshed with an input gear 12 attached to the support shaft 6, and the output gear 12 is connected to the drive motor via this gear transmission system. The feed sprocket 5 is adapted to be rotationally driven. Furthermore, the drive motor 10
A grooved pulley 13 is attached to the output shaft of , and a grooved pulley 15 is rotatably attached to the support shaft 8 via a bearing 14 . Each of these pulleys 13, 15
A timing belt 16 is wound around the belt. A fixed friction plate 17 is attached to the support shaft 8, and a movable friction plate 18 is also provided, and a coil spring 19 constantly presses the movable friction plate 18 so that it is in surface contact with the fixed friction plate 17. is interposed between the pulley 15 and the movable friction plate 18. Therefore, the rotating body 7 is rotationally driven by rotation with a constant torque or more through the above-mentioned winding transmission device and frictional force transmission device. Further, in the figure, reference numeral 20 denotes a reverse rotation input section, which is provided on the feed sprocket 5 or the support shaft 6 or 8 of the rotating body 7, and this embodiment shows the case where it is attached to the support shaft 6.

This reversal input section 20 is used to receive a driving force to reverse the feed sprocket 5 and rotating body 7 when continuous paper is set manually or automatically. This shows the case with a dial-shaped knob. Further, on the paper feeding side of the printing section, a pusher roller 21 is provided which is in pressure contact with the rotating body 7 and rotates in a direction opposite to the rotation of the rotating body 7.

The support shaft 22 supporting the pusher roller 21 is supported by the tip of a rotating arm 24 that is rotatable about a pivot 23. The rotating arm 24 is biased by a spring 25, and this spring force causes the pusher roller 21 is always brought into pressure contact with the rotating body r. Moreover, the tip of the rotating arm 24 is configured to be used as a cutter 26 located near the opposite side of the pusher roller 21 from the above-mentioned printing section, and the continuous paper A can be pressed by this cutter 26 as necessary. It's like cutting. 27 in the figure is a speed difference forming mechanism, which rotates the pusher roller 21 at a peripheral speed slightly higher than that of the feed sprocket 5 during forward rotation, and
It is used to rotate the sprocket at a peripheral speed slightly slower than that of the feed sprocket 5 during reverse rotation, and its structure in this embodiment is as follows.

That is, a forward rotation driving rotary wheel 29 is attached to the support shaft 8 of the rotary body 7, which rotates integrally with the support shaft 8 via a one-way clutch 28 when the rotary body 7 rotates in the forward direction. A reversing driving rotary wheel 31 is attached which rotates integrally with the support shaft 8 via a one-way clutch 30 when the rotation of the reversing gear 7 is reversed. A driven rotary wheel 33 for forward rotation is attached to the support shaft 22 of the pusher roller 21, which is interlocked with the driving rotary wheel 29 for forward rotation, and rotates the support shaft 22 integrally via a one-way latch 32 during this interlocking movement. At the same time, a driven rotary wheel 35 for reversing is attached which is interlocked with the driving rotary wheel 31 for reversing and rotates the support shaft 22 integrally via a one-way clutch 34 when the reversing driving rotary wheel 31 is interlocked. Note that this embodiment shows a case where gears are used as each of the rotary wheels 29, 31, 33, and 35. And each rotating wheel 29, 33 for forward rotation
The gear ratio is selected so that the circumferential speed of the rotating wheels 31 and 35 is slightly faster than the circumferential speed of each of the rotating wheels 31 and 35 for reverse rotation. In addition,
In the figure, numerals 36 to 39 all indicate stop rings attached to the support shaft 8.

Next, the operation of the paper feeding device of the above embodiment will be explained.

First, continuous paper A is set as follows.
That is, after rotating the rotating arm 24 toward the ground and separating the pusher roller 21 from the rotating body 7 (see the state indicated by the two-dot chain line in FIG. At the same time, the paper guides 3 and 4 are brought into engagement, guided to the printing section, and pulled upwards as shown by the solid line in FIG. Next, in this state, the rotating arm 24 is rotated downward and returned to its original position, thereby bringing the pusher roller 21 into pressure contact with the rotating body 7 with the leading end of the continuous paper A being sandwiched therebetween.
This state is shown in FIG. 1, and the length of the continuous paper A to be pulled out is quite large. Work is easy. After that, the reverse rotation input section 20 is rotated in order to make the margin smaller. Then, the feed sprocket 5 is reversed in the direction of arrow B via the support shaft 6, and the rotating body 7 is reversed in the direction of arrow C and the pusher roller 21 is reversed in the direction of arrow D through the reverse rotation of the drive mechanism 9 and the speed difference forming mechanism 27. is reversed. In this case, the drive motor 10 is not operated, but the rotational force from the reverse rotation input section 20 is transmitted from the support shaft 6 → input gear 12 → output gear 11 → output shaft of the drive motor 10 → pulley 13 → timing belt 16 → pulley 15 → Coil spring 19 → friction plates 17, 18
are transmitted to the rotating body 7 through the supporting shaft 8 in order, and further from the supporting shaft 8 to each rotating wheel 31, 3 for reverse rotation.
5 and the support shaft 22 via one-way clutches 30, 34.
This is transmitted to the pusher roller 21.

In this case, the rotating shafts 29, 33 for normal rotation do not transmit any rotational force due to the action of the one-way clutches 28, 32. Therefore, the above transmission system allows the pusher roller 2 to
1 is reversed at a slightly slower circumferential speed than the reversal circumferential speed of the feed sprocket 5, so that an appropriate tension can be applied to the continuous paper A being returned in the direction of arrow E by the feed sprocket 5. In this way, the continuous paper A is returned so that its leading edge faces the cutter 26, the margin is reduced, and the continuous paper A is tightly pressed against the circumferential surface of the platen 1. In this way, after the continuous paper A is set, printing by the print head 2 is started, and each time the drive mechanism 9 receives a paper feed command, the drive motor 10 is operated to transport the continuous paper A by a predetermined pitch. Ru. In this case, by driving the drive motor 10, the feed sprocket 5 is driven to rotate normally in the direction of arrow F together with the support shaft 6 through the meshing of the output gear 11 and the input gear 12. At the same time, pulley 13 → timing belt 16 → pulley 1
5→coil spring 19→friction plates 17 and 18 in this order,
The rotary body 7 is rotated and driven in the direction of arrow G together with the support shaft 8, and from the support shaft 8, each rotary body 29, 33 and one-way clutch 28, 32 for normal rotation of the speed difference forming mechanism 27 are driven.
The pusher roller 21 together with the support shaft 22 is driven to rotate normally in the direction of arrow H. In addition, each rotating body 3 for reversal
1 and 35 do not transmit rotational force in this case due to the action of the one-way clutches 30 and 34. Therefore, in this case, the pusher roller 21 is rotated in the normal direction at a circumferential speed slightly faster than the normal rotational speed of the feed sprocket 5, so that it is possible to apply tension to the continuous paper A being fed in the direction of the arrow and send it. can. Therefore, the continuous paper A can be brought into close contact with the platen 1 with appropriate tension. Note that the present invention is not limited to the above embodiment. For example, as in another embodiment shown in FIG. 4, the platen V of the printing section may be used as a rotating body, and in this way, in addition to obtaining the same effect as the above-mentioned embodiment, The number of parts is reduced, configuration and assembly are easy, and costs can be reduced. In this embodiment, the same components as those in the above-mentioned embodiment are designated by the same reference numerals, and the explanation thereof will be omitted. In addition, in the above embodiment, the power transmission system of the drive mechanism uses a gear transmission system and a wrap transmission system, but the transmission system of the output end of the drive motor and the support shaft of the feed sprocket is formed with a wrap transmission system. Alternatively, the transmission system between the output shaft of the drive motor and the support shaft of the rotating body may be formed by a gear transmission system.

Further, in the above embodiment, gears are used for each rotary wheel of the speed difference forming mechanism, but a rubber rotary wheel may be used as long as rotation can be transmitted without slippage.

When the reverse rotation input section is connected to the feed sprocket or the shaft end of the support shaft of the rotating body, it may be fixedly or variablely mounted.

In carrying out the present invention, unless it is contrary to the gist of the invention, the feed sprocket, the rotating body, the pusher roller, their support shafts, the cutter, the drive mechanism, the reverse input section, the speed difference forming mechanism, the one-way clutch, etc. It goes without saying that the specific structure, shape, position, etc. of each rotary wheel, etc., are not limited to those of the above-mentioned embodiments, and can be implemented with various configurations.

As explained above, the present invention provides a reversal input section on the support shaft of the feed sprocket or the rotary body, and rotates the feed sprocket and the rotary body synchronously in the same direction by a drive mechanism, The present invention is also characterized in that the pusher roller is driven to rotate at a circumferential speed slightly higher than that of the feed sprocket during forward rotation and at a circumferential speed slightly slower than the feed sprocket during reverse rotation by the speed difference forming mechanism.

Therefore, according to the present invention, when setting continuous paper, the leading edge of the continuous paper is pulled out and placed beyond the intended placement area of cutter 1, and then the continuous paper is moved in the opposite direction to the feed direction to align with cutter 1. Since it can be returned, the setting operation can be easily performed, and continuous paper can be used effectively by reducing the blank space. Even when the continuous paper is fed backwards, tension can be applied to the continuous paper by the speed difference forming mechanism at this time, so the continuous paper does not loosen and can be kept in close contact with the platen. The speed difference forming mechanism also ensures that the continuous paper comes in close contact with the platen when the continuous paper is fed during rotation. Therefore, it is useful for improving printing quality and reducing noise during printing.

[Brief explanation of drawings]

1 to 3 show one embodiment of the present invention, FIG. 1 is a sectional view, FIG. 2 is an enlarged sectional view of a part of FIG. It is a partial block diagram shown along the line direction in the figure. FIG. 4 is a sectional view showing another embodiment of the present invention. 1・
...Platen, 2...Print head, 5.
...Feed sprocket, 6...Support shaft,
7...Rotating body, 8...Support shaft, 9...
... Drive mechanism, 20 ... Reverse rotation input section, 21
...... Pusher roller, 22 ... Support shaft, 26 ... Cutter 27 ... Speed difference forming mechanism, 28 ... One-way clutch, 29...
...Motive power rotating wheel for forward rotation, 30...One-way clutch, 31...Motive power rotating wheel for reverse rotation, 32...
...One-way clutch, 33... Driven rotating wheel for normal rotation, 34... One-way clutch, 35...
... Driven rotating wheel for reverse rotation, V ... Rotating body (platen).

Claims (1)

[Scope of Claims] 1. Disposed on the paper feed side of the printing section, engaged with engagement holes provided at intervals along the longitudinal direction of both edges of the continuous paper,
and a feeding sprocket that can rotate in forward and reverse directions, a rotating body that can rotate in forward and reverse directions arranged on the paper feeding side of the printing section, and a pusher roller that is in pressure contact with this rotating body and rotates in the opposite direction to the rotation of the rotating body. a cutter provided near the opposite side of the pusher roller from the printing section; a drive mechanism for rotationally driving the feeding sprocket and the rotating body in synchronization in the same direction; and support for the feeding sprocket or the rotating body. a reversing input section provided on the shaft and receiving a driving force for reversing the feeding sprocket and the rotary body when the continuous paper is set; and rotating the pusher roller at a circumferential speed slightly faster than the feeding sprocket during forward rotation; A paper feeding device for a printer equipped with a speed difference forming mechanism that rotates at a peripheral speed slightly slower than that of a feeding sprocket during reverse rotation. 2. The above-mentioned speed difference forming mechanism is equipped with a driving rotary wheel for forward rotation that rotates integrally with the support shaft during forward rotation of the rotor through a one-way clutch, and a drive rotary wheel for forward rotation that rotates integrally with the support shaft during forward rotation of the rotor, and a one-way rotation drive wheel that rotates integrally with the support shaft during reverse rotation of the rotor. A reversing driving rotary wheel is attached to the support shaft of the pusher roller, which rotates together through a clutch. In addition to attaching a diversion driven rotary wheel, a reversing driven rotary wheel is attached and formed which is interlocked with the reversing motive rotary wheel and rotates the pusher roller support shaft together via a one-way clutch when this interlocking is performed, and each of these rotary wheels 2. A paper feeding device for a printer according to claim 1, wherein the pusher roller is rotated at a predetermined speed difference with respect to the feeding sprocket. 3. A paper feeding device for a printer according to claim 1 or 2, wherein the rotating body is a platen roller of a printing section.