JPS61179777A - Ribbon-shifting device for printer - Google Patents

Abstract

PURPOSE:To enhance the velocity of a mount plate in an operating range according to a printing command, by controlling the rotating speed of a lifting motor when feeding a correction ribbon or other color ribbon through engagement of a ratchet wheel with a feed pawl at the time of a mount plate shifting operation. CONSTITUTION:A carrier 3 is slidably supported on a shaft 2 parallel with a platen 1. The lifting motor 5 and a printing mechanism 6 are mounted on the carrier 3, and the mount plate 12 for a cassette casing 11 is supported so that it can be turned with a shaft 13 as a fulcrum. While a CPU25 is outputting a printing command, the plate 12 is held in a position B. In the absence of the printing command, the motor 5 is operated to lower the plate 12 to a home position A. When correcting a misprint, the motor 5 is operated to move the mount plate 12 upward to an operative position C. The CPU25 enhance the moving-up velocity of the mount plate 12 from position A to position B based on the printing command, and from position B to position C based on the correcting command.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a ribbon switching device for a printing machine.

Conventional technology Conventionally, a carrier is provided with a rotatable mounting plate that holds the cassette case containing the printing ribbon and the collect ribbon, and a lift motor mounted on the carrier moves the mounting plate to the lower home position and intermediate printing. There is a printing machine that can be switched between the printing position and the upper erasing position.

Normally, the mounting plate is located at the home position, rotates to the print position in response to a print command, and rotates to the upper erasing position when erasing characters using the collection ribbon. The mounting plate is held at the printing position when printing commands are issued at regular intervals, but returns to the home position if no printing commands are received within a fixed period. This home position is the position where printed characters are viewed. During the descending process of the mounting plate from the erasing position to the printing position, a feed pawl provided on the carrier engages with a ratchet wheel directly connected to the spool of the collect ribbon, so that the collect ribbon is fed one pitch.

Problems to be Solved by the Invention It is desirable for such items to be printed immediately when the operator operates a key, and it is also possible to print with a red ribbon or the like in the erasing position, which is limited to erasing characters. Therefore, the faster the switching speed of the mounting plate from the home position to the printing position or the erasing position, the better.

On the other hand, when the collection ribbon or the red ribbon is sent during the lowering process of the placement plate, it is necessary to require a large torque from the lift motor, and the descending speed of the placement plate from the erasing position becomes slow. This has little effect on use since the collection ribbon or red ribbon is sent less frequently.

However, conventionally, the moving speed of the mounting plate is the same regardless of the range, and if priority is given to feeding the collection ribbon etc., there is a problem that the speed becomes slow in terms of operation.

The present invention has been made in view of the above points, and an object of the present invention is to provide a ribbon switching device for a printing machine that can increase the moving speed of a mounting plate and improve operability in a range where ribbons such as a collection ribbon are not fed. With the goal.

Means for Solving the Problems This invention provides a carrier 3 equipped with a printing mechanism 6 and a ribbon feeding mechanism, and a mounting plate that holds a cassette case 11 containing a printing ribbon 10 fed by the ribbon feeding mechanism. 12 is connected movably in a direction orthogonal to the moving direction of the carrier 3, and a lift motor 5 is attached to the carrier 3 to move the mounting plate 12 between home position A, printing position B, and another operating position C. A spool 16 that holds both ends of a collection ribbon 15 or a ribbon of another color that is less frequently used is rotatably attached to the placing plate 12, a ratchet wheel 17 is connected to one of the spools 16, and the ratchet wheel 17 is engaged with the spool 16. A control means 24 is provided which urges the feed pawl 18 in the meshing direction and attaches it to the carrier 3 so that it can move forward and backward, and which controls the rotational speed of the lift motor 5.

The operational lift motor 5 switches the mounting plate 12 to any one of home position A, printing position B, and operating position C. During this switching operation, the collection ribbon 15 or a ribbon of another color is fed by the engagement between the ratchet wheel 17 and the feed pawl 18. At this time, the rotation speed of the lift motor 5 is controlled by the control means.

In the process of feeding a ribbon such as a collection ribbon, the moving speed of the mounting plate 12 is slowed down and the lift motor 5 is rotated with the necessary torque.
Increases movement speed.

Example An embodiment of the present invention will be described based on the drawings.

A carrier 3 is slidably held on a shaft 2 parallel to the platen 1. A lift motor 5 for driving a gear 4 and a printing mechanism 6 are mounted on the carrier 3. The printing mechanism 6 includes a daisy wheel 7 driven by a wheel motor, which will be described later, and a printing hammer 9 driven by an electromagnet 8. Also, the carrier 3 has an endless printing ribbon 10.
A mounting plate 12 that removably holds a cassette case 11 containing a cassette case 11 is rotatably held about a shaft 13 as a fulcrum. Further, a spool 16 for winding and holding both ends of the collection ribbon 15 is rotatably attached to bearing pieces 14 provided on both sides of the mounting plate 12, and a ratchet wheel 17 is attached to one of the spools 16.
are connected to rotate together. career 3
A feed pawl 18 meshing with a ratchet wheel 17 is biased counterclockwise by a spring 19 and is rotatably mounted around a shaft 20 as a fulcrum. The edge of the bearing piece 14 is formed into a cam shape that presses the protrusion 21 of the feed pawl 18 in the process of the mounting plate 12 being lowered from the printing position B to the home position A. Furthermore, a fan-shaped gear 22 that meshes with the gear 4 and a locking piece 23 that elastically engages with the ratchet wheel 17 are attached to the mounting plate 12 with the shaft 13 as the center of the radius.

Next, FIG. 2 shows a control means 24 for the lift motor 5.
, that is, CPU25, ROM26, and RAM2
7, a programmable timer 28, and an I10 port 29 are connected. I10 boat 29 has lift motor 5
is connected.

The RAM 26 has an area of an A register 30 and a B register 31.

Note that a carrier motor 32 that moves the carrier 3, a ribbon feed motor 33 (one component of the ribbon feed mechanism) mounted on the carrier 3 and that feeds the printing ribbon 1o, a paper feed motor 34 that drives the platen 1, a wheel motor 35,
The electromagnet 8 and the like are connected to the I10 port 29 to be controlled by the CPU 25.

In such a configuration, FIG. 1 shows a state in which the mounting plate 12 is located at printing position B. The mounting plate 12 is held at this position when a print command is issued from the CPU 25 at regular intervals. If there is no print command, lift motor 5
rotates in the CCW direction and moves the mounting plate 12 to the home position A.
lower to.

In this process, the edge of the bearing piece 14 pushes the feed pawl 18 away from the ratchet wheel 17, thereby prohibiting the feed operation of the collection ribbon 15. When erasing characters, the lift motor 5 is rotated in the CW force direction to raise the mounting plate 12 to the operating position C.

That is, the collection ribbon 10 faces the type on the daisy wheel 7.

In the process of rotating the lift motor 5 in the CCW direction to lower the placement plate 12 to the printing position B after completing the erasing operation, the ratchet wheel 17 is rotated together with the spool 16 by the feed pawl 18, and the collect ribbon 15 is fed in one pitch. It will be done.

Next, the control operation of the lift motor 5 will be explained based on the flowchart shown in FIG. The amount of movement of the mounting plate 12 is determined by the number of steps that the lift motor 5 rotates.
The step number is set in the B register 31 of the RAM 27. Should the mounting plate 12 be raised next? judge,
If it is rising, data - is set in the A register 30, and if not, data - is set in the A register 30. Then A
The contents of the register 30 are set in the programmable timer 28, and the programmable timer 28 is started.

Then, do you want to raise the mounting plate 12 again? is determined, and if it is ascending, the lift motor 5 is rotated one step in the CW force direction, and if it is descending, the lift motor 5 is rotated one step in the CCW direction. If the programmable timer 28 times up, the lift motor 5 will stop when the number of steps in the B register 31 reaches 0.

Data I set in the A register 30 is a command to speed up the rotational speed of the lift motor 5, and data ■ is a command to slow it down. Therefore, the lifting speed of the mounting plate 12 from position A to B based on the printing command and from position B to C based on the erasing command is fast. On the other hand, position C
Although the descending speed of the mounting plate 12 from B to A is slow,
This lowering process involves a large load because the collection ribbon 15 is sent or the bearing piece 14 retracts the feed pawl 18 from the ratchet wheel 17, which is convenient for obtaining a large torque from the lift motor 5.

Further, a software program may be used that changes the moving speed of the mounting plate 12 between positions A and B and between positions B and C in accordance with changes in load.

Note that the present invention also includes a configuration in which a less frequently used ribbon, such as a red ribbon, is used in place of the collection ribbon 15.

Effects of the Invention Since the present invention is constructed as described above, when the position of the mounting plate is switched by the lift motor, the movement speed of the mounting plate is controlled by the operation of the control means within the range where the collection ribbon or the like is fed. This has the effect of increasing the torque of the lift motor by slowing it down, and increasing the moving speed of the mounting plate in other operating ranges associated with printing commands, thereby improving operability.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a side view, FIG. 2 is a block diagram, and FIG. 3 is a flow chart. 3... Carrier, 5... Lift motor, 6... Printing mechanism, 10... Printing ribbon, 11... Cassette case.

Claims (1)

[Claims] A mounting plate that holds a cassette case containing a printing ribbon sent by the ribbon feeding mechanism is connected to a carrier carrier equipped with a printing mechanism and a ribbon feeding mechanism so as to be movable in a direction perpendicular to the moving direction of the carrier. A lift motor is attached to the carrier to move the placement plate between a home position, a printing position, and another operating position, and both ends of a collection ribbon or a ribbon of another color that is less frequently used are held on the placement plate. A spool is rotatably attached to the carrier, a ratchet wheel is connected to one of the spools, and a feed pawl that meshes with the ratchet wheel is urged in the meshing direction to be attached to the carrier so as to be movable forward and backward, and the printing is performed from at least the home position. A ribbon switching device for a printing machine, comprising: a control means for controlling the rotational speed of the lift motor so as to increase the moving speed of the placement plate when moving from the home position to the operating position.