JPH0761734B2 - Printer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer in which a ribbon mechanism is not mounted on a carriage but is installed outside the carriage and prints in both left and right directions.

[Prior art]

FIG. 1 shows the configuration of a ribbon mechanism of a conventional printer of this type.

That is, the print head 1 prints on the print sheet 4 set between the platen 3 and the ink ribbon 2 by driving a wire pin (not shown).

The printing head 1 is mounted on the carriage 6, and when the carriage 6 is driven by the operation of the carriage driving motor 5, the carriage 6 moves in the left-right direction and prints when the head 6 moves to the left or right.

At this time, if you try to print in the reverse direction immediately after printing in one direction, the ink surface used once immediately before that will be used again in the reverse direction printing, so that clear printing can be performed. It was difficult.

Therefore, for example, during printing in the right direction, the ribbon supply spool 7
When the ribbon take-up spool 8 is stopped and printing is completed up to the right end and the print head 1 is returning to the left and printing is performed, the ribbon take-up spool motor 9 is driven to operate the ribbon take-up spool 8. A structure has been proposed in which a new ink surface is exposed on the front surface of the printing head 1.

That is, after carrying out printing in one direction, the carriage is temporarily stopped, during which the ink ribbon is wound a predetermined length to reveal a new ink surface, and then printing is carried out in the opposite direction. Was there.

However, in the printer having such a structure, printing is not performed during the time when the ink ribbon is wound up, so that there is a drawback that the average printing speed becomes extremely slow.

When a one-time ribbon is used as the ink ribbon, or when a thermal transfer ribbon is used in thermal transfer printing, in order to perform printing in one direction and then in the opposite direction, the moving speed of the print head 1 is twice or more. The only method is to move the ribbon in the same direction as the print head 1 at a speed.

〔Purpose〕

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a printer capable of clearly printing in both left and right directions at a high speed.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

2 to 4 illustrate one embodiment of the present invention.
In this embodiment, a wire head is used as the print head. Further, in the figure, the same or corresponding parts as in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 2 illustrates the ribbon mechanism of the printer according to the present invention.

In other words, this ribbon mechanism uses two upper and lower ink ribbons.
10, 11, upper and lower ribbon take-up spools 12, 13 and upper and lower ribbon take-up spool motors 14, 15 for driving these upper and lower ribbon take-up spools 12, 13 and upper and lower ribbon supply spools 16, 17, respectively.

Incidentally, FIG. 3 shows the spool portion in an enlarged manner. Third
The drawing is a cross-sectional view of the spool portion located on the left side in FIG.

That is, the upper ribbon take-up spool 12 is engaged with the upper ribbon take-up spool motor 14,
The upper ribbon take-up spool 17 can be operated independently of the upper ribbon take-up spool 12.

Returning to FIG. 2, reference numeral 18 is a ribbon up / down motor, and the tip of the rotary shaft 18a of the motor 18 is fixed to an eccentric disc-shaped cam 19.

The reference numeral 20 designates an ink ribbon holding portion. This ink ribbon holding portion 20 is a thin plate formed in a substantially E shape, holds slidably the upper and lower ink ribbons, and moves upward by means not shown. The upper end surface of the cam 19 is in contact with the peripheral edge of the cam 19.

Next, the operation of this embodiment configured as described above will be described.

First, for example, in order to perform printing in the right direction, the upper ink ribbon 10 is moved while the printing head 1 mounted on the carriage 6 is moved in the right direction by driving the carriage driving motor 5.
To print via.

At this time, since the upper ribbon take-up spool motor 14 for moving the upper ink ribbon 10 is stopped, the upper ribbon take-up spool 12 does not operate and the upper ink ribbon 10 is stopped.

On the other hand, the lower ink ribbon 11 is for printing in the left direction, and when the lower ribbon take-up spool motor 15 is operated by driving the lower ribbon take-up spool motor 15, the lower ribbon take-up spool 13 is driven.
Rolled up to 13.

This winding operation is performed during the above-described rightward printing, that is, until the carriage reaches the right end.

The length of the lower ink ribbon 11 wound on the lower ribbon take-up spool 13 is equal to the length used for printing in the previous leftward printing. That is, the used portion of the lower ink ribbon 11 is wound up, and a new unused ink surface is paid out from the lower ribbon supply spool 17.

In this way, when the printing in the right direction is completed, the ink ribbon up / down motors 18, 18 are driven and the lower ink ribbon 11 is set on the front surface of the printing head 1.

FIG. 4 shows an ink ribbon up / down mechanism which is a means for switching the ink ribbon.

That is, when the ink ribbon up / down motor 18 is driven, the cam 19 rotates via the rotation shaft 18a. At this time, since the rotating shaft 18a is fixed at a position displaced from the center of the cam 19, the ink ribbon holding portion is
20 moves up and down, and the ink ribbons 10 and 11 held by the ink ribbon holding portion 20 also move up and down.

Therefore, depending on the position of the cam 19, the ink ribbon is either the upper ink ribbon 10 or the lower ink ribbon 11 and the printing head 11
Will be set in front of.

If the lower ink ribbon 11 is set on the front surface of the print head as described above, the lower ink ribbon 11 has an unused ink surface, so that the printing operation to the left can be started immediately. .

At this time, since the lower ribbon take-up spool motor 15 is not driven, the lower ink ribbon is stopped while the upper ribbon take-up spool motor is being driven, as in the case of printing in the right direction.
14 drives to drive the upper ink ribbon 10 to the upper ribbon take-up spool
Take it up to 12 and prepare for the next printing to the right.

When the printing in the left direction is completed, the ink ribbon up / down motor 18 is driven again to set the upper ink ribbon 10 on the front surface of the printing head 1.

By repeating the above operation, printing can be performed in both left and right directions.

The present invention can be applied not only to the above-described embodiment but also to a printer using a ribbon cassette instead of the ribbon spool, for example.

Further, an electromagnetic solenoid may be used instead of switching and setting two upper and lower ink ribbons by using a ribbon up / down motor and a cam.

[Effect]

As is clear from the above description, according to the present invention, a printing unit and a carriage that is equipped with the printing unit and that performs bidirectional printing in the forward and backward paths by the printing unit while reciprocating with respect to the print medium. And a ribbon mechanism provided outside the carriage, the ribbon mechanism being capable of transferring two upper and lower ink ribbons at both ends of the reciprocating movement region of the carriage along the movement direction of the carriage. While the ink ribbon holding section which holds the two ink ribbons in common in the state and the two ink ribbons are independently transferred along the moving direction of the carriage, while one of the ink ribbons is being used for printing by the printing means. And the other ribbon transfer means for transferring the other ink ribbon to the printable position of the printing means, and the ink ribbon holding portion in the vertical direction. By doing so, a configuration is provided that includes a switching unit that switches and sets the ink ribbon so that one of the two upper and lower ink ribbons uses the printing by the printing unit. Since the ink ribbon for reverse printing can be transferred at the time of printing, the ribbon switching means can be provided outside the carriage, and the ink ribbon can be switched while holding two ink ribbons. Therefore, it is possible to provide an excellent printer which does not need to change the relative position of, and has a high average printing speed and is capable of bidirectional printing with clear printing.

[Brief description of drawings]

FIG. 1 is a perspective view of a ribbon mechanism and a carriage in a conventional printer, FIGS. 2 to 4 are diagrams for explaining one embodiment of the present invention, and FIG. 2 is a perspective view of the ribbon mechanism adopted in the present invention. 3 is a partially enlarged vertical front view of FIG. 2, FIG.
The figure is a perspective view of the ink ribbon up / down mechanism. 1 ... Printing head, 2 ... Ink ribbon, 4 ... Printing paper, 6 ... Carrier, 7 ... Ribbon supply spool, 8 ... Ribbon take-up spool, 10 ... Upper ink ribbon, 11 ... Lower ink ribbon, 12 ... Upper ribbon take-up spool 13 …… Lower ribbon take-up spool 14 …… Upper ribbon take-up spool motor 15 …… Lower ribbon take-up spool motor 16 …… Upper ribbon supply spool 17 …… Lower ribbon supply spool 18,18 …… Ink ribbon up / down motor 19,19 …… Cam 20,20 …… Ink ribbon holding unit

Claims (1)

[Claims] 1. A printer having a printing means, comprising a carriage for performing bidirectional printing in forward and backward directions by the printing means while reciprocating with respect to a printing medium, and a ribbon mechanism provided outside the carriage. The ribbon mechanism includes an ink ribbon holding unit that holds two upper and lower ink ribbons commonly at both ends of a reciprocating movement region of the carriage in a movable state along a moving direction of the carriage; Each of the ink ribbons is independently moved along the moving direction of the carriage, and while one of the ink ribbons is used for printing by the printing means, the other ink ribbon is moved to a printable position of the printing means. By moving the ribbon transfer means and the ink ribbon holding portion in the vertical direction, the two upper and lower ink ribbons are moved. Printer either is characterized in that it comprises a switching means for setting switching the ink ribbon to be used for printing by said printing means.