JPS61220885A - Ribbon position shifting device - Google Patents

Abstract

PURPOSE:To enhance accuracy in positioning and enable clear printing, by a construction wherein a cam for displacing an engaging body provided on a carrier in the width direction of a ribbon is provided on the carrier so that it can be freely rotated and be fixed at an arbitrary position. CONSTITUTION:When a stepping motor 16 is rotated a predetermined number of steps, the rotation is transmitted to a gear 19, and a cassette support base 14 is turned together with a cassette casing 12 in the width direction of the ribbon 11, with a support shaft 15 as a fulcrum, by an amount corresponding to one pitch of an engaging part 22. When there are errors in the sizes or fitting dimensions of the casing 12 or engaging bodies 23, 25, the centers of zones 8, 9, 10 come off the center of the printing position. In such a case, a setscrew 30 is untightened, and the cam 27 is turned, whereby the engaging body 25 is displaced in the width direction of the ribbon 11 because it is supported by an eccentric part, and the center of the zone 8 is opposed to the center 32 of the printing position. Once the center of one of the zones is matched to the center of the printing position, the center of any one of the zones 8, 9, 10 can be matched to the center 32 of the printing position through engagement of the engaging bodies 23, 25.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to a ribbon position switching device used in a printing machine.

Conventional technology Conventionally, a cassette case containing multicolored ribbons was mounted on a cassette support stand on a carrier, the cassette support stand was moved to an arbitrary position in the width direction of the ribbon to select a desired printing color, and the cassette case was removed. There is a printing machine in which a pair of locking bodies that elastically engage with each other are provided on the cassette case and the carrier, thereby improving the positioning accuracy of the cassette case.

Interstitial Points to be Solved by the Invention However, since variations in the dimensions of the locking body, cassette case, and carrier, and variations in position when mounting the locking body accumulate, the positioning accuracy of the cassette case becomes low. For this reason, the center of the desired zone cannot be positioned at the regular printing position, leading to problems such as missing the upper or lower part of the characters or mixing colors.

The present invention was made in view of the above points, and an object thereof is to improve the positioning accuracy of the cassette case, perform clear printing, and adjust the position of the ribbon position switching device.

Means for Solving the Problems The present invention provides at least one zone 8 of the ribbon 11;
9. A pair of locking bodies 23.25 having a plurality of locking parts 22 or 24 corresponding to the number of 10 and engaging each other with the locking parts 22 and 24 are provided, and one locking body 23 is attached to the cassette case. The other locking body 25 is biased toward the locking body 23 on the cassette case 12 and movably attached to the carrier 5, and the locking body 25 on the carrier 5 is attached to the ribbon 11. A cam 27 for displacing in the width direction is provided on the carrier 5 so as to be rotatable and fixed at any desired position.

The switching of the working ribbon is carried out by the drive mechanism 20 on the cassette support stand 1.
4 is displaced along with the cassette case 12 in the width direction of the ribbon 11, and the locking bodies 23 and 25 are engaged to fix the position of the cassette case 12.

The position of the cassette case 12 is adjusted by turning the cam 27 and displacing the locking body 25 on the carrier 5 in the width direction of the ribbon 11.

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

A carrier 5 on which a print head 4 serving as a printing mechanism is mounted is slidably held on carrier shafts 2 and 3 parallel to the platen 1. A ribbon guide 6 is fixed to the tip of the print head 4, and a plate 7 that partitions between the ribbon 11 and the paper is fixed. The ribbon 11 is color-coded into a plurality of zones 8, 9, and 10 in its width direction, and a ribbon cassette 13 is formed by housing this ribbon 11 in a cassette case 12.

Further, a cassette support base 14 that removably holds the ribbon cassette 13 is rotatably held on the carrier 5 about a support shaft 15 as a fulcrum. Furthermore, a step motor 16, a gear 17 directly connected to this step motor 16, and a gear 18 that meshes with this gear 17 are attached to the carrier 5,
A gear 19 that meshes with this gear 18 is mounted on a cassette support stand 14.
A drive mechanism 2o is formed by fixing to □. The gear 19 has a large number of teeth on a radius around the support shaft 15.

Then, the same number of locking parts 22 as the number of zones 8, 9, and 10 of the ribbon 11 are attached to the mounting base 21 provided on the cassette case 12.
A sawtooth-shaped locking body 23 is fixed. A locking body 25 paired with this locking body 23 has a locking part 24 that engages with either of the locking parts 22, and a cam 27 that rotatably holds this locking body 25 is attached to a carrier 5. It is rotatably held by a mounting plate 26 which is helically fixed to the mounting plate 26. A spring 31 is wound around this cam 27 and urges the locking body 25 toward the locking body 23 side. A groove 29 that engages with a driver is formed in the head 28 of the cam 27, and a fixing spiral 30 that presses the head 28 and restricts the movement of the cam 27 is screwed into the mounting plate 26.

In such a configuration, when the step motor 16 is rotated in either direction with a fixed number of steps, the rotation is transmitted to the gear 19, and the cassette support base 14, together with the cassette case 12, adjusts the width of the ribbon 11 about the support shaft 15. The locking portion 22 is rotated by one pitch in the direction. If the cassette support base 14 is rotated upward by one pitch from the state shown in FIG. 4, zone 9 will be opposed to the printing position, and if it is further rotated by one pitch, zone 10 will be opposed to the printing position.

If there is a dimensional error in the cassette case 12, the locking body 23.25 or the installation of the locking body 23.25, the center of zones 8, 9.10 will be at the printing position as shown in Figures 7 and 8. off center. At this time.

The fixing spiral 30 is loosened and the cam 27 is rotated. Therefore, since the two locking bodies are held on the eccentric part of the cam 27, they are displaced in the width direction of the ribbon 11, and the center of the zone 8 is moved as shown in FIG. is opposite to the center 32 of the printing position. If the center of one zone is aligned with the center of the printing position, the error in the pitch of the locking part 22 is extremely small. It can be aligned with the center 32.

Note that the locking body 25 may be fixedly provided on the cassette case 12 and attached to the carrier 5 so that the locking body 23 is biased toward the print head 4 side and displaced in the width direction of the ribbon 11 by the cam 27. .

Effects of the Invention Since the present invention is configured as described above, errors occur in the dimensions of parts such as the cassette case and the locking body.

Alternatively, even if there is an error in the dimensions when installing the locking body, the position of the locking body on the carrier in the width direction of the ribbon can be adjusted using a cam to align the center of the ribbon zone with the center of the printing position. This has the effect of making it possible to obtain clear printing.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially sectional and enlarged side view showing a stopper of the locking body, and FIG.
The figure is an enlarged vertical sectional side view showing the support structure of the locking body on the carrier side, FIG. 3 is a longitudinal front view enlarged and showing the support structure of the locking body on the carrier side, and FIG. 4 is a partially cutaway view FIG. 3 is a side view showing the overall structure. FIG. 5 is a perspective view of the ribbon cassette, and FIGS. 6 to 8 are partially cutaway side views showing changes in the position of the ribbon.

Claims (1)

[Claims] A ribbon cassette in which ribbons color-coded into a plurality of zones in the width direction are housed in a cassette case is provided, and a cassette support stand on which the ribbon cassette is detachably held and a cassette support stand on a carrier equipped with a printing mechanism are provided. a driving mechanism for moving the ribbon in the width direction, and a pair of locking bodies, at least one of which has a plurality of locking portions corresponding to the number of zones, and which engage with each other using the locking portions. , the one locking body is fixedly provided on the cassette case, and the other locking body is biased toward the locking body on the cassette case and displaceably attached to the carrier,
A ribbon position switching device characterized in that a cam for displacing the locking body on the carrier in the width direction of the ribbon is provided on the carrier so as to be rotatable and fixed at any position.