JPH0750220Y2 - Ribbon feed mechanism of serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a ribbon feeding mechanism of a serial printer in which a pulse motor sequentially supplies a current to each phase during ribbon feeding and a lock current during stop. (2) Conventional Technology and Problems One example of a conventional ribbon feed mechanism using a pulse motor is shown in FIGS. 1 (a) and 1 (b). A ribbon feed mechanism 10 for moving the ribbon in the A direction between the print head 1 and the platen 2 shown by a broken line in FIG. That is, as shown in the cutaway portion of FIG. 7A and the side sectional view of FIG. 7B, the ribbon cassette 7 is set, and its feed roller is driven from the pulse motor 3 via the drive gear 4 to drive the ribbon 5 Is wound up. This feed roller shaft extends as a feed knob and is used for manual adjustment.
To drive the ribbon feed mechanism 10, the phase currents of the pulse motors are sequentially fed to transfer the ribbon, and the ribbon is locked when stopped. In order to prevent the ribbon from loosening when locked, a mechanism of a ratchet 8 which is locked by an elastic pawl 9 shown in FIG. 2 is provided on the axis of the feed knob 6, and fine winding adjustment is performed by permitting only the forward rotation direction. . But,
In an actual device, there was a drawback that the ratchet 8 was not engaged with the pawl 9 and the lock was unstable. (3) Purpose of the invention The purpose of the invention is to perform a stable manual adjustment without using the ratchet in a ribbon feeding mechanism of a serial printer in which each phase current is sequentially fed at the time of ribbon feeding by a pulse motor and a lock current is fed at a stop. It is to provide a ribbon feeding mechanism of a serial printer which is made possible. (4) Configuration of the Invention In order to achieve the above-mentioned object, the ribbon feeding mechanism of the serial printer of the present invention is arranged such that each phase of the multi-phase pulse motor at the time of ribbon feeding is inside the printer cover including at least the print head portion of the ribbon feeding mechanism. In the ribbon feeding mechanism of the serial printer having a pulse generating means for sequentially flowing a pulse current to the lock current at the time of stop, a switch means for detecting the opening and closing of the printer cover, and a detection output at the time of opening, And a means for reducing the lock current at the time of stop. (5) Embodiment of the Invention The outline of the invention is as follows. If the ratchet mechanism 8 is simply omitted, the ribbon may loosen when stopped. Therefore, in order to unlock or reduce the lock only when adjusting manually, a switch (not shown) that responds to the opening and closing of the printer cover (not shown) is provided, and the lock circuit is controlled by this disconnection. It is a thing. Third
The figure is a diagram for explaining the configuration of an embodiment of the present invention. In the figure, a switch 12 that responds to the opening and closing of the printer cover.
With the above operation, when the cover is closed, the pulse motor 3 is driven by the motor drive circuit 15 via the ribbon feed pulse generation circuit 13 to perform the above-described ribbon feed and stop lock operation. On the other hand, when the printer cover is opened, the ribbon feeding pulse generating circuit 13 is controlled via the cover opening control circuit 14 to unlock or weaken the lock, and the manual adjustment by the feed knob 6 is performed. It should be easy to do. (6) Effect of Consideration As described above, according to the present invention, in the ribbon feeding mechanism of the serial printer, when the slack of the ribbon is manually corrected, the lock is unlocked or locked by the switch responsive to the opening and closing of the printer cover. To weaken and adjust manually. This enables stable and easy ribbon setting without using an unstable ratchet mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration explanatory view of a conventional example and an embodiment of the present invention, FIG. 2 is an explanatory diagram of a main part of the conventional example, and FIG. 3 is a control circuit of an embodiment of the present invention. 1 is a print head, 2 is a platen, 3 is a pulse motor, 4 is a drive gear, 5 is a ribbon, 6 is a feed knob, 7 is a ribbon cassette, 8 is a ratchet, 9 is a pawl, and 10 is a ribbon feed. A mechanism, 12 is a switch, 13 is a ribbon feed pulse generation circuit, 14 is a cover open control circuit, and 15 is a motor drive circuit.

Claims (1)

[Claims for utility model registration] In the printer cover including at least the print head part of the ribbon feed mechanism, a pulse current is sequentially applied to each phase of the multi-phase pulse motor during ribbon feed, and a lock current is applied during stop. In a ribbon feeding mechanism of a serial printer including pulse generating means, switch means for detecting opening / closing of the printer cover,
A ribbon feeding mechanism for a serial printer, comprising: means for reducing the lock current at the time of stop by the detection output at the time of opening.