JPH0829593B2 - Print head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head, and more particularly to a print head for a wire dot printer.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing an example of one printing element of a conventional print head. Referring to FIG. 5, a print wire 2 is attached to the tip of an armor chair 1, and the tip of the print wire 2 is guided by a wire guide 3 at the front of the head so as to project outward. The armature chair 1 is supported by a leaf spring 4, and the leaf spring 4 is fixed to a core 6 via a yoke 5. A coil 7 for excitation is attached to the outer periphery of the core 6. In this configuration, the magnetic circuit formed by the yoke 5, the armature 1 and the core 6 is attracted toward the core 6 by the magnetic flux generated by the energization of the coil 7, whereby the tip of the printing wire 2 is not shown. Printing is performed by colliding with the ink ribbon and the print medium.

FIG. 6 is a block diagram of a conventional print head.
6A is a view seen from the tip side of the printing wire 2, FIG.
FIG. 6B is a sectional view taken along line AA of FIG. In FIG. 6, a leaf spring 4 having an armature 1 and a print wire 2 attached to the ends thereof is arranged in a circle to form a print head having 12 or 24 print wires.

[0004]

In the conventional print head, there is a portion where the armature 1 and the core 6, the tip of the print wire 2 and the print medium collide with each other at two mechanical elements during the printing operation. , The noise during printing is large.

Further, since a slender wire is used for printing, it is difficult to express the print density gradation by controlling the magnetic force due to bending of the wire and friction between the print wire 2 and the wire guide 3. .

[0006]

The print head of the present invention comprises:
The first magnetic member having a print pin attached to one end and the other end supported by a leaf spring, and the first magnetic member facing the one end and arranged at a position sandwiching the ink ribbon and the print medium. The second magnetic member is equipped with a coil that attracts the magnetic member when energized and returns it to the original position by the reaction force of the leaf spring when de-energized.

[0007]

Next, the present invention will be described with reference to the drawings.

Referring to FIG. 1 showing the configuration of the first embodiment of the present invention, in the print head of this embodiment, an armature chair 11 made of a magnetic material has a printing pin 1 at one end.
2 is attached and the other end is supported by the leaf spring 13.
The leaf spring 13 is fixed to an upper unit (not shown). Similarly, the core 14 made of a magnetic member is arranged at a position sandwiching the ink ribbon 16 and the print medium 17 so as to face the printing pin 12 at one end of the armature 11. A coil 15 that returns to the original position by the reaction force of the spring 13 is attached. The core 14 is fixed to a lower unit (not shown) together with the coil 15. The upper unit and the lower unit are always arranged with a constant space.

The print head driving means (not shown) is the coil 1.
When an electric current is applied to 5, magnetic flux is generated in the core 14 and the armature 11, and an attractive force is generated between them. Since the armature chair 11 can move within the range of elastic deformation of the leaf spring 13,
It is sucked in the direction of the core 14, that is, in the direction of the arrow 18.
At this time, the printing pin 12 collides with the print medium 17 via the ink ribbon 16 and transfers the ink on the ink ribbon 16 onto the print medium 17. When the printing pin 12 collides with the ink ribbon 16 and the printing medium 17, the coil 1
By cutting off the current flowing through the armature 5, the armature chair 11 is moved in the direction of the arrow 19 by the reaction force of the leaf spring 13 and pulled back to the original position.

As described above, the armor chair 11 is attached to the core 14.
When the printing operation is performed by sucking the ink, since there is no mechanical friction between the printing wire and the wire guide as in the conventional case, the suction force of the armature chair 11 is changed by changing the magnitude or the time of the current applied to the coil 15. Can be changed linearly to easily control the printing force. That is, the speed at which the print pin 12 collides with the ink ribbon 16 and the print medium 17 changes, the print pressure of the print pin 12 changes, and as a result, print density with gradation can be obtained.

In this print head, the head components do not collide with each other, and only the printing pins 12, the ink ribbon 16 and the print medium 17 collide during the printing operation. That is, noise during printing operation can be suppressed as much as possible, and energy loss can be minimized.

FIG. 2 is a diagram showing the configuration of the second embodiment of the present invention. FIG. 2 (a) is a side view of this embodiment, and FIG.
(B) is a front view of this embodiment. Referring to FIG. 2, the print head of this embodiment is of a line type by arranging a predetermined number of units each including an armature 11 having a printing pin 12 and a core 14 having a coil 15 shown in FIG. It can be a print head. Since there is no long print wire as in the past, a small print head can be obtained.

FIG. 3 is a diagram showing the configuration of a third embodiment of the present invention, and FIG. 3 (a) is a side view of this embodiment, and FIG.
FIG. 3B is a front view of this embodiment, and FIG. 3C is FIG.
It is a BB arrow line view of. Referring to FIG. 3, in the print head of this embodiment, units each including an armature 11 having a printing pin 12 and a core 14 having a coil 15 shown in FIG. 1 are arranged in a line at a predetermined angle with respect to a printing direction. By doing so, a serial type print head can be obtained. By arranging the printing pins by shifting them by the dot pitch, the print head is moved in the lateral direction to form an arbitrary dot row.

FIG. 4 is a diagram showing the construction of a fourth embodiment of the present invention, and FIG. 4 (a) is a side view of this embodiment, and FIG.
4B is a front view of this embodiment, and FIG. 4C is FIG. 4B.
It is a CC arrow line view of FIG. Referring to FIG. 4, the print head of this embodiment has a unit composed of an armature 11 having a printing pin 12 and a core 14 having a coil 15 shown in FIG. By arranging them, the total length of the print head can be kept short.

Since the print head of the present invention is capable of expressing gradation, by using an ink ribbon of three or four colors, it is possible to form a full-color image even though it is a dot matrix print head. ing.

[0016]

As described above, according to the present invention, the first magnetic member having the printing pin attached to one end and the other end supported by the leaf spring and the one end facing each other. And a second magnetic member mounted at a position sandwiching the ink ribbon and the print medium, and having a coil attached to which the first magnetic member is attracted when energized and returned to its original position by the reaction force of the leaf spring when deenergized. With the provision, the print density can be controlled, that is, the gradation can be expressed, and the print noise and energy can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 5 is a configuration diagram showing an example of one printing element of a conventional print head.

FIG. 6 is a configuration diagram of a conventional print head.

[Explanation of symbols]

 11 Armor Chair 12 Printing Pin 13 Leaf Spring 14 Core 15 Coil 16 Ink Ribbon 17 Printing Medium 18 Arrow 19 Arrow

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Claims (4)

[Claims] 1. A first magnetic member having a printing pin attached to one end and a second end supported by a leaf spring, and a first magnetic member disposed at a position facing the one end to sandwich an ink ribbon and a printing medium. And a second magnetic member equipped with a coil that attracts the first magnetic member when energized and returns to the original position by the reaction force of the leaf spring when not energized. 2. A of claim 1, wherein said first and second magnetic members having a predetermined number are arranged in a row
Print heads. 3. The print head according to claim 1, wherein a predetermined number of the first and second magnetic members are arranged in a line at a predetermined angle with respect to the main scanning direction . 4. The print head according to claim 1, wherein a predetermined number of the first and second magnetic members are arranged in a plurality of rows at a predetermined angle with respect to the main scanning direction .