JPS6412237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer in which a print head moves back and forth in the width direction of recording paper.

In this type of printer, the print head mounted on the carriage rubs against the ink ribbon as it moves, and printing elements such as a print hammer strike the ink ribbon and recording paper at high frequencies, creating static electricity on the print head. Occur. Carriages are made of engineering plastic in recent years, so the static electricity generated in the print head when the head moves has nowhere to go and accumulates in the print head.
Eventually, it will discharge and cause the printer to malfunction, or even break down in severe cases.

The present invention aims to solve the above-mentioned disadvantages, and one embodiment thereof will be described below with reference to the accompanying drawings.

In FIG. 1, a carriage 5, which is moved to the right via an appropriate drive means (not shown), is slidably fitted into guide shafts 3 and 4 installed between side plates 1 and 2. There is. The carriage 5 is made of plastic, and a head support plate 8 is attached to its upper surface via screws 6 and 7. The front part of the head support plate 8 is integrally bent, and the metal part of the print head 9 is supported there through pins 10 and 11. A platen 12 located in front of the print head 9 is fixed to side plates 1 and 2, and a recording paper 13 and an ink ribbon 14 are inserted between them.
A locking piece 15, which is an example of a fixing member that is bent and formed integrally with the side plate 1, has one end 16a of a return spring 16.
is hung. The middle part of the return spring 16 is tensioned in a meandering manner via pulleys 19 and 20 that are rotatably supported by tongue-shaped parts 17 and 18 that are integrated with the side plates 1 and 2, and the other end part 16b is integrated with the carriage 5. It is hung on a hook 21 protruding from the.

This return spring 16 causes the carriage 5 to move to the first position.
A return force is applied to the left in the figure. In this embodiment, in order to electrically connect the head support plate 8 and the return spring 16, an extending portion 22 as a conductive member is integrally formed from the rear of the head support plate 8.
The end of the extending portion 22 is positioned so as to overlap the upper surface of the hook 21 of the carriage 5, and the end 16b of the return spring 16 is inserted into the second through hole formed at the end of the hook 21 and the extending portion 22. It is hung through as shown.
As a result, the end of the extending portion 22 and the end 16b of the return spring 16 come into contact with each other.

When the carriage 5 is moved to the right along the guide shafts 3 and 4, the print head 9 is driven and the desired print is made on the recording paper 13. When one line of printing is completed, the carriage 5 is moved by the restoring spring. It is returned to the home position by the spring force of 16. When the head moves, the front part of the print head 9 rubs against the ink ribbon 14, and during printing, the printing elements (not shown) of the print head 9 strike the ink ribbon 14 and the recording paper 13 at high speed. At this time, static electricity is generated in the print head 5, but this static electricity is dropped onto the side plate 1 via the head support plate 8, its extension 22, and the return spring 16. That is, the return spring 1
6 not only provides a restoring force to the carriage 5, but also serves as a ground wire for discharging static electricity generated in the print head 9 onto the side plate 1.

Note that the above embodiment can be modified as follows. For example, the hook 2 protruding from the carriage 5
1 may be omitted and the end portion 16b of the return spring 16 may be directly hooked to the extension portion 22 or a part of the head support plate 8. Further, in order to electrically connect the end portion 16b of the return spring 16 and the head support plate 8, a lead wire may be separately provided in place of the extension portion 22, for example.

According to the present invention described above, the return spring is used not only as a member that applies a return force to the carriage, but also as a ground wire for dropping static electricity generated in the print head to the ground, so that the print head is not exposed to static electricity. Therefore, countermeasures against static electricity to prevent malfunctions can be implemented very easily, and costs will not increase. Furthermore, if the conductive member for electrically connecting the head support plate and the return spring is integrally formed and extended from the head support plate, there is no need to additionally install any extra parts.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view thereof, and FIG. 2 is a plan view thereof.
FIG. 1, 2... Side plate, 3, 4... Guide shaft, 5...
Carriage, 8... Head support plate, 9... Printing head, 13... Recording paper, 14... Ink ribbon,
15...Latching piece (fixing member), 16...Return spring,
21...Hook, 22...Extending portion (conducting member).

Claims (1)

[Scope of Claims] 1. A head support plate connected to a metal part of a print head is fixed to a carriage made of an insulating material that is slidably supported by a guide shaft and is grounded. The other end of the return spring, one end of which is hooked to the metal component, is hooked to the carriage via the head support plate or a conductive member that is electrically connected to the head support plate. A serial printer that also serves as the ground wire for the head. 2. Claim 1, wherein the conductive member is an extending portion integrally formed to extend from the head support plate.
Serial printers listed in section.