JPH09300671A - Shuttle mechanism of dot line printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the accuracy in detecting the speed of a hammer bank, that is incorporated in a shuttle mechanism and put in reciprocating motion by a stepping motor, and improve the quality of print, by providing a guide to restrain vibrations of a magnetic memory wire that detects the speed of the hammer bank. SOLUTION: A stepping motor 6 mounted on one of two pulleys 4 of a dot line printer is operated to bring a hammer bank 1 fixed by a slide bearing 3 in reciprocating motion. An end of a magnetic memory wire 7 is fastened to the slide bearing 3, and the transfer amount of the magnetic memory wire 7 is detected by a magnetic type sensor 8 to detect the speed of the hammer bank 1. Guides 9 are respectively provided at the fixed end and the free end of the magnetic memory wire 7 to restrain vibrations of the magnetic memory wire 7. Thereby, the magnetic memory wire 7 is restrained from vibrating when a shuttle mechanism is brought in operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shuttle mechanism for reciprocating a hammer bank in a printing apparatus generally called a dot line printer. More specifically, it relates to a magnetic memory wire and a magnetic type. The present invention relates to a device that more accurately corrects the speed fluctuation of the hammer bank in a shuttle mechanism section that detects the speed of the hammer bank using a sensor.

[0002]

2. Description of the Related Art In a dot line printer, a printing method is to reciprocate a single or a plurality of printing hammers in a direction perpendicular to a paper feeding direction by a shuttle mechanism, and in this process, the printing hammers are appropriately driven through an ink ribbon. As a result, characters, figures, etc. are printed on the printing paper in the dot matrix format.

In order to obtain good print quality in such a dot line printer, the speed of the hammer bank on which the print hammer is mounted is detected with high accuracy, and the speed fluctuation amount with respect to the target speed is absorbed by the correction of the print timing. There must be.

There are various methods for detecting the speed of the hammer bank, and FIG. 5 shows an example of the prior art, which will be described below.

The hammer bank 1 is fixed by a slide bearing 3 so as to be slidable in the axial direction on a shaft 2 extending in the girder direction. Further, the slide bearing 3 is attached to the timing belt 5 that connects the two pulleys 4. A stepping motor 6 is attached to one of the pulleys 4, and the hammer bank 1 is reciprocated by driving the pulley 4 by the stepping motor 6.

The slide bearing 3 has S at certain intervals.
One end of the magnetic memory wire 7 on which the pole and the N pole are recorded is fixed, the moving amount of the magnetic memory wire 7 is detected by the magnetic sensor 8, and the hammer bank 1 of the hammer bank 1 is detected based on the detected signal. The speed is read, the print fluctuation is corrected for the speed fluctuation amount with respect to the target speed, and after the corrected time, the printing hammer is driven to print.

[0007]

Conventionally, one end (hereinafter, referred to as a fixed end) of a magnetic memory wire is fixed to a slide bearing to which a hammer bank is attached, and the other end (hereinafter, referred to as a free end) vibrates in a shuttle or the like. It was not fixed in order to prevent the magnetic memory wire from being damaged by. Therefore, during the shuttle operation, vibration was generated in the magnetic memory wire between the portion supported by the magnetic sensor and the fixed end, and at the free end.

In the sensor, the actual speed of the hammer bank is detected by adding the speed fluctuation due to the vibration of the magnetic memory wire. For this reason, there has been a problem that the speed fluctuation affects the correction of the print timing, and the print timing position created from the detected speed deviates from the legally printed position, and the print quality deteriorates.

A first object of the present invention is to alleviate the above-mentioned drawbacks of the prior art, to reduce the difference between the speed of reading from the detection signal of the magnetic sensor and the speed of the actual hammer bank, and to prevent the printing timing from deviating. It is to provide a shuttle mechanism that can be suppressed.

A second object of the present invention is to provide a shuttle mechanism section which simplifies the above means.

[0011]

The first object is achieved by attaching a guide to the magnetic memory wire for suppressing movement other than the movement direction.

The second object is achieved by integrating the guide with the cover of the magnetic sensor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a shuttle mechanism section of a dot line printer, and its basic construction is the same as that of FIG. However,
Guides 9 for suppressing vibration are provided on the fixed end side and the free end side of the magnetic memory wire 7.

FIG. 2 is simplified by integrating the guide 9'of FIG. 2 with a component for covering the magnetic sensor 8.

When the shuttle mechanism section is operated, vibration is generated in the magnetic memory wire, but if the guide 9 is attached as described above, the vibration can be suppressed. This effect will be described below.

The state of vibration of the magnetic memory wire 7 when the guide 9 is attached is shown in FIG. 3a, and the state of vibration of the magnetic memory wire 7 without the conventional guide is shown in FIG. 3b. The detection signal of the magnetic sensor 8 in each case is shown in FIGS.

Comparing FIGS. 3a and 3b, it can be seen that the amplitude is smaller when the guide is provided. As a result, the detection signal according to the present invention shown in FIG. 4a has a more stable waveform than the detection signal according to the prior art shown in FIG. 4b.

According to the present invention, since the vibration of the magnetic memory wire can be suppressed as described above, the hammer bank speed read from the detection of the moving amount of the magnetic memory wire by the magnetic sensor and the actual hammer bank. The difference from the speed is reduced. As a result, the deviation of the print timing is suppressed, and the print quality is improved.

[0020]

According to the present invention, the vibration of the magnetic memory wire can be suppressed, and the accuracy of speed detection of the reciprocating motion of the hammer bank can be improved. As a result, print quality is improved.

If the guide and the magnetic sensor are integrated, the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a vibration state of a magnetic memory wire.

FIG. 4 is a diagram showing a detection signal of a magnetic sensor.

FIG. 5 is a perspective view showing a conventional technique.

[Explanation of symbols]

1 is a hammer bank, 2 is a shaft, 3 is a slide bearing, 4 is a pulley, 5 is a timing belt, 6 is a stepping motor, 7 is a magnetic memory wire, 8 is a magnetic sensor, and 9 is a guide.

Claims (2)

[Claims] 1. A hammer bank having a plurality of printing hammers, a shaft extending in the girder direction of the hammer bank, a slide bearing for fixing the hammer bank slidably in the axial direction, and the slide bearing attached thereto. And a timing belt connecting two pulleys, a stepping motor for driving one of the pulleys, a magnetic memory wire having one end fixed to the slide bearing, and a magnetic memory wire attached to the magnetic memory wire. With a magnetic sensor,
A shuttle mechanism section of a dot line printer that reciprocates the hammer bank by driving the stepping motor, wherein a guide for suppressing vibration of the magnetic memory wire is provided. 2. A shuttle mechanism section for a dot line printer according to claim 1, wherein a part for covering the magnetic sensor and a guide for suppressing vibration of the magnetic memory wire are integrated.