JPH0613228B2 - Printer - Google Patents

Description

Description: (a) Technical Field of the Invention The present invention relates to a mechanism of a print medium conveying unit and a print unit of a shuttle printer device (Shuttle Printer) used in, for example, a portable bookkeeping machine.

(B) Background of Technology In recent years, a portable simple bookkeeping machine operated by a diplomat such as a financial institution at a customer has been developed and put into practical use.

It is desirable that such a bookkeeping machine be small and lightweight and have a simple structure.

(C) Conventional Technology and Problems The conventional technology will be described below with reference to FIG. It is a side view which shows the conventional Example of FIG.

The print medium 1 is inserted in the direction of arrow A from the left side of the medium transport path 2 in the figure. At this time, the pinch roller 3 is separated from the feed roller 4 and is in the state (open) of the pinch roller 3'shown by the two-dot chain line.

On the other hand, a stopper 5 which projects at a right angle to the medium conveying path 2 at the rear of the feed roller 4 and which is provided so as to be orthogonal to the conveying direction of the print medium 1 closes the medium conveying path 2 and is a stopper 5'shown by a two-dot chain line. Is in the closed state.

Therefore, the tip of the print medium 1 inserted into the medium transport path 2 contacts the stopper 5 '.

After that, the pinch roller 3 ′ in the open state is brought into contact with the feed roller 4 to bring the pinch roller 3 into the state (closed) by a manual stopper operation, and at the same time, the stopper 5 ′ in the closed state is conveyed. The path 5 is evacuated and the stopper 5 is opened.

In such a state, the print medium 1 is reliably and accurately sandwiched between the feed roller 4 and the pinch roller 3, and the rotation of the feed roller 4 in the direction of the arrow B causes the print head 6 and the platen 7 to be printed. Sent to the department for printing.

The print medium 1 after printing is discharged to the outside by the discharge roller 8.

However, the above-described print medium feeding mechanism has a complicated structure and may be expensive.

(D) Object of the Invention It is an object of the present invention to provide a printing apparatus which has a simple structure and which can satisfy the functions.

(E) Structure of the Invention In order to achieve this object, the present invention conveys a print medium to be set through a medium conveying path to a platen and a printing unit facing the platen and a gap between the printing unit and the platen. In the printing device configured to perform printing by reciprocating the printing medium surface by the printing unit, the platen is a medium that comprises at least a pair of feed rollers and a driving unit that moves the printing unit in parallel along the printing medium. It is provided so as to be movable between a first position that closes the transport path and a second position that is retracted from the medium transport path, and is transferred while the platen is located at the first position. A side surface with which the leading end of the print medium in the traveling direction contacts is provided on the platen.

Platen moving means for moving the platen to the first position and the second position, a means for detecting the position of the platen with respect to the medium transport path, and a side surface of the platen located at the first position with the feed roller separated from each other. After the tip of the print medium in the traveling direction comes into contact with
The feed roller is joined and the platen is moved to the second position. Based on the detection signal of the movement of the platen to the second position from the detection means, the feed roller is driven to move the print medium to the printing unit and the platen. And a control unit that controls the feed roller and the platen moving unit so that the sheet is transferred to the gap and set.

(F) Embodiment of the Invention One embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

2 (a) and 2 (b) are side views showing the operation of the printing apparatus according to the present invention, FIG. 2 (c) is an enlarged side view of the printing section of FIGS. 2 (a) and 2 (b), and FIG. Is a view as seen from the direction of arrow C in FIG.

In the figure, 6'is a print head, 9 is a platen, 10 is an arm, 11 is a platen shaft, 12 is a metal fitting, 13 is a cam follower, 14 is a coil spring, 15 is a platen cam, 16 is a contact wheel, 17 is a A sensor, 19 is a carrier, 20 is a cylinder cam, 21 is a cam groove, 22 is a guide pin, and 23 is a motor.

The same reference numerals denote the same objects throughout the drawings.

The print head 6'of the shuttle printer device to which the present invention is applied has a predetermined number of print heads 18 as shown in FIG.
Is mounted on the carrier 19 at a pitch L.

The structure of the print head 18 is such that it has only one pin as compared to a wire dot printer, for example.

As shown in FIG. 3, the carrier 19 has a guide pin 22,
The guide pin 22 is engaged with the cam groove 21 of the cylinder cam 20 provided in parallel with the platen 9.

Therefore, when the cylinder cam 20 is rotated by the motor 23, the guide pin 22 slides in the cam groove 21, and as a result, the carrier 19 reciprocates with a stroke of pitch L in the arrow EF direction in the drawing. .

As shown in FIG. 2, the print head 6'and the platen 9 are
When the print medium 1 is inserted between and, the feed roller 4 is rotated by a motor (not shown) to print only one pin during printing in the direction of arrow A in the figure, and a line feed after printing. The medium 1 is adapted to be sent.

In the printer according to the present invention, in order to simplify the structure, the stopper 5 of the prior art is eliminated, and the platen 9 is used instead.
To and from the medium transport path 2 to function as a stopper for the print medium 1 in addition to the original function of the platen.

The platen 9 according to the present invention is provided so as to be movable between a first position that closes the medium transport path 2 and a second position that is retracted from the medium transport path 2.

Further, the platen 9 is provided with a side surface with which the leading end in the traveling direction of the transferred print medium 1 abuts when the platen 9 is located at the first position.

More specifically, as shown in FIG. 2, the platen 9 has a rectangular plate shape with a narrow width in a side view. An arm 10 is erected almost at the center of the side surface of the platen 9, and the other end of the arm 10 has a platen shaft
It's locked up at 11.

Both ends of the platen shaft 11 are pivotally supported by bearings (not shown). Therefore, the platen shaft 11
The platen 9 swings with the rotation of the
The upper part of the sheet moves in and out of the medium transport path 2.

The platen 9 is mounted in a relational position such that the upper end surface of the platen 9 presses the print head 6'in a state of being orthogonal to the print head 6 '.

A metal fitting 12 is fixed to the platen shaft 11. This metal fitting
Reference numeral 12 is fixed to the platen shaft 11 so that the P-shaped head thereof holds the platen shaft 11 in a sideways P-shape in a side view.

On the other hand, the platen cam 15 rotated by the drive of the motor 23
And a cam follower that swings following the rotation of the platen cam 15.
13 is provided, and the other end of the cam follower 13 is rotatably engaged with the end of the metal fitting 12 by a hinge structure.

The cam follower 13 is provided with a contact wheel 16 at its tip, and when the contact wheel 16 is driven along the outer peripheral surface of the platen cam 15, the cam follower 13 swings.

The intermediate portion of the cam follower 13 presses the metal fitting 12 via the coil spring 14. This pressing force works as a force for pressing the platen 9 against the print head 6 '.

A sensor 17 is provided at the lower end of the platen 9 (the lower part shown in the figure) to detect whether the platen 9 is inserted in the medium transport path 2 (that is, the first position).

As shown in FIG. 2 (a), the platen cam 1 is driven by the motor 23.
When 5 rotates and the cam follower 13 is at the top dead center of the platen cam 15, the cam follower 13 rotates the platen shaft 11 and presses the platen 9 against the print head 6'to bring it to the first position. There is.

At this time, the lower end of the platen 9 is out of the position of the sensor 17 as shown in the figure, and the sensor 17 causes the platen 9 to project into the medium transport path 2 and press the print head 6 '. It is detected that it is located at position 1.

Further, as shown in FIG. 2 (b), when the platen cam 15 rotates and the cam follower 13 is at the bottom dead center of the platen cam 15, the cam follower 13 rotates the platen shaft 11,
The platen 9 is separated from the surface of the print head 6 ′, retracted from the medium transport path 2, and positioned at the second position.

At this time, the lower end of the platen 9 is at the position of the sensor 17 as shown in the figure, and the sensor 17 detects that the platen 9 is retracted from the medium transport path 2, that is, located at the second position. .

With respect to such a printing apparatus, the procedure of the printing operation will be described. First, as shown in FIG. 2 (c), the feed roller 4 is opened like 4'by a manual operation or a magnet, and the printing medium 1 is set as a medium. Insert into the transport path 2.

At this time, the control unit (not shown) drives the platen cam 15 according to the open information of the feed roller 4 to drive the platen 9
Are projected into the medium transport path 2.

That is, the platen 9 closes the medium transport path 2.

When the sensor or the like (not shown) detects that the insertion of the print medium 1 is completed, the control unit issues a command to return the feed roller 4'to the closed state of 4, and the feed roller 4'is returned.
And the pinch roller 3 to narrow the print medium 1,
The platen cam 15 is rotated to retract the platen 9 from the medium transport path 2.

When the retraction of the platen 9 is detected by the sensor 17, the control unit issues a command to drive a line feed motor (not shown) to rotate the feed roller 4 to move the print medium 1 to a predetermined position on the print head 6 '. Send to position.

When a sensor (not shown) or the like detects that the print medium 1 has reached a predetermined position, the platen cam 15 rotates in response to a command from the control unit, and the platen 9 again projects into the medium transport path 2 and the print medium 1 Is clamped between the print head 6 ′ and the platen 9.

Then, as shown in FIG. 3, the motor 23 is driven to rotate the cylinder cam 20 and the print head 6'is moved by the pitch L to print one line.

When the printing for one line is completed, the platen 9 is once retracted from the medium transport path 2 and the feed roller 4 is rotated to transport the print medium 1 for one pin. Then, the platen 9 is again pressed against the print head 6'to print the next line.

Although the platen cam 15 also rotates when the motor 23 rotates, the shape of the cam is set to a predetermined value so that the platen 9 does not move during printing.

Printing is performed by repeating the above-mentioned operation. When all printing is completed, the control section inspects the printing completion information, retracts the platen 9 from the medium transport path 2, and feeds the motor for line feed.
23 reversely rotates and the feed roller 4 reversely rotates.
Are discharged to the outside.

(G) Effects of the Invention As described above, by applying the printing apparatus of the present invention, the mechanism becomes extremely simple, and it is possible to realize the miniaturization, weight reduction and cost reduction of the apparatus.

[Brief description of drawings]

FIG. 1 is a side view showing a conventional embodiment, FIGS. 2 (a) and 2 (b) are side views showing the operation of the printing apparatus according to the present invention, and FIG. 2 (c) is an enlarged side view of the printing section. 3 is a view taken in the direction of arrow C in FIG. In the figure, 1 is a print medium, 2 is a medium transport path, 3 is a pinch roller, 4 is a feed roller, 5 is a stopper, 6 and 6'are print heads, 7 and 9 are platens, 10 are arms, and 11 are platen shafts. , 12 is a metal fitting, 13 is a cam follower, 14 is a coil spring, 15 is a platen cam, 16 is a contact ring, 17 is a sensor, 18 is a print head, 19 is a carrier, 20 is a cylinder cam, 21 is a cam groove, 22 is a guide pin. , 23 are motors, respectively.

Claims (1)

[Claims] 1. A platen, a printing unit facing the platen, at least a pair of feed rollers for transferring a print medium to be set through a medium transport path to a gap between the printing unit and the platen, A printing apparatus configured to move a printing unit in parallel along the printing medium, the printing unit reciprocating on the printing medium surface to perform printing, wherein the platen conveys the medium. It is provided so as to be movable between a first position that closes the path and a second position that is retracted from the medium transport path, and when the platen is located at the first position, transfer is performed. A side surface of the platen, which comes into contact with the leading end of the print medium in the traveling direction, is provided on the platen, and a platen moving unit that moves the platen to the first position and the second position; Position relative to the road And the feed roller is joined to the platen after the tip of the print medium in the traveling direction comes into contact with the side surface of the platen located at the first position with the feed roller separated. To the second position, and based on a detection signal of the movement of the platen to the second position from the detection means, the feed roller is driven to move the print medium to the print unit and the platen. And a control unit that controls the feed roller and the platen moving unit so that the feeding roller and the platen are moved and set in a gap therebetween.