JPS6213813Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an impact type printer having a rotatably selected type wheel.

Conventionally, in this type of printer, a ribbon cassette is provided for the type wheel, and printing is performed via an ink ribbon that is fed by the ribbon cassette to the front surface of the type surface of the type wheel. However, in such a device using a ribbon cassette, functions such as a ribbon shift mechanism are required to increase the number of prints that can be made, and the number of components increases, making it impossible to simplify the device. In addition, the weight becomes large, which may adversely affect other mechanisms. Furthermore, ribbon cassettes are prone to poor ribbon winding and to the ribbon being caught by the ribbon shift mechanism.

As a method that does not use such a ribbon, it has been considered to use an ink application roller as described in, for example, Japanese Unexamined Patent Publication No. 146309/1983. However, no consideration is given to the mounting structure of the ink application roller. In addition, there is only one ink application roller,
Since the ink contacts the type surface of the type wheel less frequently, there is a risk that the ink supply will be insufficient and print quality will be impaired.

Furthermore, as seen in Japanese Unexamined Patent Application Publication No. 141014/1984, there are also ink rollers in which the ink roller is made into a cassette. This type of cassette is large and requires considerable space, and cannot be used in type wheel type printers.

This invention has been made in view of these points, and aims to provide a printer that can reliably supply ink to the typeface and that requires less space for the ink-impregnated roller.

An embodiment of this invention will be described based on the drawings. First, a carriage body 2 is provided which can freely reciprocate along the axial direction of the platen 1, and a selection motor 3 is fixed onto this carriage body 2. A petal-shaped type wheel 5 is attached to the shaft 4 of the selection motor 3 and is rotated and selected by the selection motor 3. That is, a plurality of movable pieces 6 extending radially from the center have typefaces 7 at their tips, with the typeface 8 facing the platen 1. Here, it is set so that the printed characters 7 located directly above are located at the printing position relative to the platen 1 side. Further, a hammer 9 is provided which performs a printing operation from the back side of the type 7 located at this printing position. This hammer 9 is also supported and fixed to the carriage body 2, although not particularly shown.

A roller cassette 10 is provided which is located on the front side of the type wheel 5 and is detachably attached to the carriage body 2. This roller cassette 10 is formed into a frame shape so as to avoid the upper side of the type wheel 5 so as not to interfere with the printing operation by the hammer 9, but not to hinder the rotation of the type wheel 5, and is opened on the side of the type wheel 5. A space 10a is formed. A plurality of ink-impregnated rollers 11 impregnated with ink are rotatably attached to the roller cassette 10. These ink-impregnated rollers 11 are arranged so as to correspond to the rotation locus of the type 7, exposed to the type face 8, and positioned so that the type face 8 comes into rotational contact.

In such a configuration, the selection motor 3 is rotated by the print signal, and the type wheel 5 is rotated so that the type 7 to be printed is positioned directly above.
Then, hammer 9 for this selected type 7
The printing operation is performed by. Here, when the type wheel 5 rotates, the type surface 8 of the type 7 comes into rotational contact with the ink-impregnated roller 11 and moves toward the printing position while being supplied with ink, so that printing is performed reliably. Such operations are performed in the same way no matter which type of character 7 is selected.

Therefore, according to this embodiment, it is sufficient to install the roller cassette 10 having the ink-impregnated roller 11 at a predetermined position, and the conventional ribbon cassette which requires many components for the ribbon shift mechanism etc. is not required. Since the number of component parts is small, the device can be simplified. Furthermore, this roller cassette 10 is lightweight and does not have any adverse effect on other mechanisms. Further, since the roller cassette 10 is removably attached to the carriage body 2, it can be easily replaced when the print density decreases.

By the way, when printing continuously, there is a possibility that the print density becomes thin, so to control this, for example, when printing the same type 7 more than once, the type wheel 5 should be rotated a predetermined amount before printing. Just do it. Further, the mounting position of the ink-impregnated roller 11 with respect to the roller cassette 10 is arbitrary as long as it corresponds to the rotation locus of the printed characters 7, but in consideration of ink application, it is advantageous to mount the ink impregnated roller 11 as close to the periphery of the printing area as possible. On the contrary, it can be said that it is more advantageous in terms of space to concentrate these ink-impregnated rollers 11 on the lower side.

This invention has a plurality of ink-impregnated rollers that rotate in contact with the type surface of the type wheel as described above, so ink can be smoothly supplied to the type surface, and in particular, since there are multiple ink-impregnated rollers The type wheel can be placed close to the type wheel to provide sufficient ink supply as the type wheel rotates in either direction for type selection, thereby eliminating redundant printing. Printing quality can be improved without causing an ink shortage even when printing is performed, and since the ink-impregnated rollers are installed in the space of the roller cassette, multiple rollers can be installed in accordance with the rotation locus of the type. Moreover, since the roller cassette is flat, it does not take up much space.
This makes it possible to simplify the device.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a schematic side view, and FIG. 2 is a front view of a part thereof. 3... Selection motor, 5... Type wheel, 7... Type, 8... Type surface, 9... Hammer, 10... Roller cassette, 10a... Space, 11... Ink impregnated roller.

Claims (1)

[Scope of utility model registration request] A type wheel in which type is formed at the tips of a plurality of movable pieces extending radially from the center, and the type is rotated and selected by a selection motor, and a hammer located on the back side of the type on the type wheel to determine the printing position. In an impact type printer, a flat roller cassette is detachably disposed opposite to the type wheel and has a shape that misses the printing position where the hammer is located, and the roller cassette has a roller cassette attached to the type wheel side. The present invention is characterized in that an open space is formed, and a plurality of ink-impregnated rollers are rotatably mounted in the space at positions corresponding to the rotation locus of the type, each contacting the type surface of the type. printer.