JPS646029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a printing hammer that is supported by an elastic support plate and is attracted and held by a pole by the attraction force of a permanent magnet at a retracted position where the elastic support plate is elastically deformed. The present invention relates to a printing device that prints by moving the printing hammer and releasing the printing hammer during the reciprocating movement.

As such a printing device, for example,
As disclosed in Japanese Patent No. 40221, there is a dot matrix printer in which the printing hammer is a printing pin that prints dots.The dot matrix printer will be described below as an example.

As shown in FIG. 1, the printing hammer drive device of a dot matrix printer includes a printing pin 6 which constitutes the printing hammer of the present invention, and a leaf spring 5 which constitutes the elastic support plate of the present invention, on the front of which is attached a plunger 7 made of magnetic material. , a permanent magnet 1, a front yoke 2, a rear yoke 3, and a release electromagnetic coil 4 wound around the upper leg or pole portion 30 of the rear yoke 3. The lower end, that is, the fixed end of the leaf spring 5 is fixed to a spacer 8 provided on the front surface of the permanent magnet 1 via a screw 9 passing through the front yoke 2. Note that 10 is a screw for fixing the leaf spring 5 to the spacer 8. Further, a groove is provided at the upper end of the front yoke 2, through which a printing pin 6 and a plunger 7 pass.

The printing pin 6 is held on the pole portion 30 by the magnetic attraction force of the permanent magnet 1 at the retreated position where the leaf spring 5 is elastically deformed. When the electromagnetic coil 4 is excited, the magnetic attraction force is canceled out, and the leaf spring 5 flies due to its restoring force, and the printing pin 6
is caused to collide with a platen (not shown) via a printing paper (not shown) and an ink ribbon (not shown). Dots are printed on this printing paper.

Therefore, the permanent magnet 1, yokes 2, 3, etc. are extended along the printing position, and a plurality of plate springs 5 supporting the printing pin 6 are arranged in parallel along the printing position, and a hammer (not shown) housing these components is constructed. One line printing is possible by reciprocating the printing paper along the printing position via a bank and step-feeding the printing paper one dot line at a time, and energizing the electromagnetic coil and releasing the printing pin 6 during the reciprocating movement. Become. That is, the hammer bank is reciprocated by a distance corresponding to the number of digits printed by one printing pin 6.

The following problems occurred in the dot printer with the above configuration. That is, when more than a predetermined number of electromagnetic coils 4 are excited and the printing pins 6 are released, there is a problem that the release of the printing pins 6 is delayed and the character arrangement characteristics are deteriorated. This phenomenon was discovered in Japanese Unexamined Patent Application Publication No. 1983-
It is also disclosed in Publication No. 56885, and the electromagnetic coil 4
There is a method that prevents the release from being delayed by increasing the excitation time of the electromagnetic coil 4, but there is a new problem that the control becomes complicated and the heat generation of the electromagnetic coil 4 increases.

Further, if the central printing pin 6 is released after a predetermined time delay after the printing pins 6 on both sides have been released, the release is delayed and the character arrangement characteristics deteriorate as described above.

This phenomenon is thought to be because the magnetic flux flowing through the pole sections 30 on both sides flows into the center pole section 30, increasing the magnetic attraction force at the center and delaying offset by the excitation of the electromagnetic coil 4. In this case as well, it is possible to prevent the release from being delayed by increasing the excitation time of the electromagnetic coil 4 as described above, but the same problem as described above occurs.

An object of the present invention is to eliminate the above-described drawbacks of the prior art and to prevent deterioration in print quality.

By driving and printing the printing hammers of only odd number digits or only even number digits of the present invention, there is a delay in the release of the printing hammers when more than a predetermined number of printing hammers are driven, or a delay in the release of the central printing hammer. It is characterized by preventing.

FIG. 2 shows an embodiment of the present invention, in which the electromagnetic coil 4 is wound around pole parts 30 of even number digits, but not around pole parts 30 of odd number digits. Further, the printing pin 6 is not provided on the plate spring 5 which is attracted and held by the pole portion 30 of the odd numbered digit. That is,
Printing pins 6 are provided only on the leaf springs 5 of even number digits.

As a result, even if more than a predetermined number of electromagnetic coils 4 are excited, the magnetic flux flowing through the pole portion 30 can flow into the adjacent odd-numbered pole portion 30, so that the pole portion 30 of the digit that is to be released is The magnetic attraction force will no longer increase, and release will no longer be delayed. In other words, the character arrangement characteristics do not deteriorate. Furthermore, there is no delay in the release of the central digit, and the character arrangement characteristics do not deteriorate. In addition,
According to this embodiment, the pole portions of the odd-numbered digits act as cooling fins to dissipate the heat generated in the even-numbered digits by thermal conduction, so that the cooling capacity is increased and high-load printing is possible.

Although the printing pins 6 are driven only for even-numbered digits, they may be driven only for odd-numbered digits, and although the printing pins 6 are provided only for even-numbered digits, they may be provided for all digits. (Although half of them are never used).

In the above embodiment, the printing pins 6 of only odd numbered digits or even numbered digits are driven and printed depending on the mechanical structure, but the electromagnetic coil 4 and the printing pins 6 are provided for all digits, and the odd numbered digits are electrically connected. The printing pins 6 may be controlled so as to drive only or only the printing pins 6 for even-numbered digits. In this case, it is also possible to alternately drive the printing pins 6 for only odd-numbered digits or only for even-numbered digits, and the life of the printing pins 6 and the like can be extended. Further, although the embodiment has been described as a dot matrix printer, it is also possible to use the printing pin 6 as a normal printing hammer and apply it to a line printer that prints by colliding with type on a type carrier.

As described above, according to the present invention, it is possible to prevent delays in releasing the printing hammer without requiring complicated control or causing problems such as new heat generation, and improve printing quality such as character arrangement characteristics. can be improved.

[Brief explanation of the drawing]

The figures show a dot matrix printer which is an embodiment of the device of the present invention, in which FIG. 1 is a sectional side view showing an example of a printing hammer drive device, and FIG. 2 is an exploded perspective view showing one embodiment. be. In the figure, 1 is a permanent magnet, 2 is a front yoke, 3 is a rear yoke, 30 is a pole part, 4 is a release electromagnetic coil, 5 is a leaf spring (elastic support plate), 6 is a printing pin (printing hammer), and 7 is a Plunger, 8 is a spacer,
9 and 10 are fixing screws.

Claims (1)

[Claims] 1. A permanent magnet extending along the printing position, a yoke having a plurality of poles arranged in parallel along the printing position, supported by an elastic support plate, and the elastic support plate being elastically deformed. The hammer is equipped with a printing hammer that is attracted and held on the pole in a retracted position, a release electromagnetic coil attached to the pole, and a hammer bank that accommodates these permanent magnets, a yoke, an elastic support plate, a printing hammer, etc. A printing device that reciprocates a bank along a printing position, excites the releasing electromagnetic coil during this reciprocating movement, releases the elastic support plate, and prints with a printing hammer, the printing device being provided along the printing position. Among the plurality of printing hammers, the printing hammer is provided with a means for driving only one of the odd-numbered digits and even-numbered digits, and the printing hammer of only one of these digits is driven to perform printing. printing device. 2. The device according to claim 1, characterized in that the means for driving the printing hammer for only one digit is a release electromagnetic coil attached only to poles for odd-numbered digits or even-numbered digits. Printing device. 3. The means for driving the printing hammer for only one digit is a printing hammer supported only for odd-numbered digits or even-numbered digits of the elastic support plate. printing device. 4. Claim 1, characterized in that the means for driving the printing hammer for only one digit is constituted by electric means that excites only odd-numbered digits or even-numbered digits of the release electromagnetic coil. Printing device as described in section.