JPS6364766A - Printing head - Google Patents

Abstract

PURPOSE:To obtain a good printing, by performing printing operation in such a state that a printing wire moves along with the other end of an armature in the case of a plurality of printing papers while performing printing operation in such a state that the printing wire is separated from the other end of the armature to move by the inertial force of the wire itself in the case of one printing paper. CONSTITUTION:When one printing paper is printed, the distance between printing paper and the printing end of a printing wire 27 is set and, since a wire holder 39 is supported so as to be made separable with respect to the leading end part 25a of an armature 25, only the printing wire 27 moves over a required stroke by the inertial force of the wire itself against the elastic force of a return spring 31. When a plurality of printing papers are printed, the exciting current corresponding to printing data is applied to a coil 9 and the printing wire 27 is subjected to printing operation by the revolution of the armature 25. At this time, the impact force of the printing wire 27 is set so as to be made larger than that when one printing paper is printed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a print head that prints print data in a dot impact format, and more specifically, to a print head that prints print data in a dot impact format. This invention relates to a mounting structure for a printing wire used in printing.

[Prior Art] A conventional print head includes a number of armatures that are rotatably supported at the circumferential end of a cylindrical yoke, an electromagnet that faces each armature, and an electromagnet that urges each armature toward the non-printing side. and a printing wire that is brazed and joined at the tip of the armature. When the electromagnet is magnetically driven, the printing head rotates the armature with an impact force corresponding to the magnetic attraction force of the electromagnet, so that the printing wire flies and the printing data is printed in a dot impact format. There is.

[Problems to be Solved by the Invention] However, the above-described conventional print head prints so that the impact force is maximized when printing on a single sheet of printing paper, as shown by the broken line in FIG. The wire stroke is set. Therefore, since the printing wire always comes into contact with the printing paper through the printing ribbon with a strong force, printing noise increases and the printing wire and printing ribbon are seriously damaged.

Furthermore, when printing on three or four stacked sheets of paper, such as those used for slip paper, for example, the stroke of the printing wire becomes shorter, resulting in a reduction in impact force. For this reason, the 3rd and 4th sheets of paper may have blurred or missing dots, etc.
There is a problem that print quality deteriorates. This problem can be solved by providing a mechanism that adjusts the distance between the printing end of the printing wire and the printing paper depending on the number of sheets to be printed, but the problem is that the equipment 2 becomes complicated, increases the cost, and becomes difficult to operate. have.

[Object of the Invention] In view of the above-mentioned conventional drawbacks, the object of the present invention is to provide a method with low printing noise, little damage to printing wires and printing ribbons, and good printing on single and multiple sheets of printing paper stacked together. The objective is to provide a print head that can be obtained.

[Means for Solving the Problems] Therefore, the present invention provides a yoke in which a large number of electromagnets are arranged, an armature arranged to face each electromagnet,
A frame rotatably supports one end of each armature between the end face of the yoke, and a frame that is supported separably from the other end of the armature and rotates by the action of an electromagnet. The printing head consists of a printing wire whose head is struck and performs the printing operation, and is supported at a predetermined distance from a platen that supports the printing paper.The printer overlaps multiple sheets of printing paper and prints on the printing paper. In this case, the printing operation is performed with the printing wire moving together with the other end of the armature, and when printing on a single sheet of printing paper, the printing wire separates from the other end of the armature and the inertia of the wire itself The print head is configured by setting the amount of rotation of the armature so that the printing operation is performed while being moved by force.

[Operation of the Invention] Since the present invention is configured as described above, when printing on a single sheet of printing paper, the printing operation is performed with the printing wire separated from the armature and moved by the inertia of the wire itself. Therefore, printing can be performed when the impact force of the printing wire becomes less than the maximum impact force. Furthermore, when printing on printing paper made of multiple sheets stacked one on top of the other, the printing operation is performed while the printing wire moves together with the armature, so printing can be performed before the impact force of the printing wire reaches its maximum. I can do it. This makes it possible to reduce printing noise and damage to the printing wire and printing ribbon, and furthermore, it is possible to obtain good printing on single sheets and multiple sheets of printing paper stacked one on top of the other.

[Example] Hereinafter, a practical example of the present invention will be explained with reference to the drawings.

FIG. 1 is a poly perspective view schematically showing a print head according to the present invention;
FIG. 2 is a longitudinal sectional view of the center of the road body in FIG. 1, and FIG. 3 is a perspective view showing how the printing wire is attached to the armature.
The yoke 3 of the print head 1 is made of a magnetic material having high saturation magnetic flux density characteristics, and is integrally formed into a cylindrical shape with a circumferential edge extending toward the armature 25. An opening 5 is formed in the center of the front surface of the yoke 3, and a nose portion 17, which will be described later, is inserted into the opening 5. Inside the yoke 3, a large number of cores 7 forming part of an electromagnet are integrally formed at required intervals in the circumferential direction, and a coil 9 forming a part of the electromagnet is wound around each core 7. The coil bobbin 11 is press-fitted and fixed. A board (not shown) is attached to the front surface of the yoke 3, and the lead end of each coil 9 is connected to one end of the electric wire printed and wired on the board, and the print head of the printing device is connected to the other end. Electric wires of a flexible cable (none of which is shown) connected to a drive circuit (none of which is shown) are soldered to each other. An excitation current corresponding to print data is applied to each coil 9 via the flexible cable.

A frame 15 made of synthetic resin is provided within the peripheral edge of the yoke 3.
is inserted. The frame 15 has a nose portion 17 and a support plate 19 integrally molded.

The support plate 19 is integrally formed with a large number of support walls 19a extending in the radial direction from the center at required intervals in the circumferential direction, and the support plate 19 has cutouts 19b corresponding to the distance between each support wall 19a. It is formed to correspond to the core 7. A recess 19c is formed at the radial end of the support plate 19, and a base end of an armature 25, which will be described later, is rotatably supported in the recess 19c. Further, a hole 19 is provided on the centripetal side of the support plate 19.
d is formed, and a printing wire 2 described later is formed in the through hole 19d.
7 is slidably inserted. An intermediate guide member 21 and a front end guide member 23 are installed in the nose portion 17, and the intermediate guide member 21 guides the printing wires 27, which are arranged in a substantially circular shape through the through hole 19d, gradually into a straight line toward the tip. The slide is guided so that Further, the front end guide member 23 slides and guides the printing end of the printing wire 27 vertically in a straight line through its guide hole.

Armatures 25 are supported on the support plate 19 so as to face each core 7 through the notches 19b. Each armature 25 is made of a magnetic material having high saturation magnetic flux density characteristics, and arm portions 25p are integrally formed on both sides of the rotating base end thereof in accordance with the recessed portion 19c.

A printing wire 27 is separably attached to the tip of each armature 25 via a wire holder 29. The wire holder 29 is made of synthetic resin, and as shown in FIG. 3, the printing wire 27 is inserted and fixed into a pair of supporting parts 29a that face each other at a distance so as to sandwich the tip 25a of the armature 25. It is composed of a fixed part 29b,
The wire holder 29 is supported between its support portions 29a such that the tip portion 25a of the armature 25 is slidable. Note that the navigation support portion 29a prevents the wire holder 29 from rotating in its axial direction.

The printing wire 27 is guided to the nose portion 17 via the hole 19d. And a support plate 19 corresponding to the eye hole 19d.
A return spring 31 as an elastic member is attached to the printing wire 27 between the wire holder 29 and the wire holder 29, and the armature 25 is urged toward the non-printing side by the elastic force of the return spring 31.

A rear frame 33 made of synthetic resin is attached to the rear of the frame 15 on which the armature 25 is supported.

The front center portion of the rear frame 33 is integrally molded.

Further, a leaf spring 35 is attached to the front surface of the rear frame 33. This plate spring 35 is integrally formed with a ring part 35a that is inserted into the radial end of each projection 33a, and a suppression piece 35b that extends from the ring part 35a toward the base end of each armature 25. The piece 35b presses the base end of each armature 25 toward the rear end surface of the yoke 3 by its elastic force. In addition, 37 in the figure is a mounting bracket.

Next, the operation of the print head 1 constructed as described above will be explained with reference to FIG. 4.

First, to explain the case of printing on a single sheet of printing paper, in FIG. 4, which shows the relationship between the printing stroke of the printing wire 27 and the impact force, when an excitation current is applied to the coil 9 according to printing data, , yoke 3 and core 7
A magnetic path of lines of magnetic force generated by excitation of the coil 9 is formed between the armature 25 and the armature 25 . As a result, the armature 25 is magnetically attracted toward the coil 9 side, rotates around the recess 19c against the elastic force of the return spring 31, and the distal end 25
a moves to the left in FIG. 2 while in contact with the wire holder 29. The armature 25 comes into contact with the core 7 at a position where its tip 25a has moved the required stroke 10, and stops its rotation. Tip portion 25a of the armature 25
When printing is performed on the printing paper by the printing end of the printing wire 27 at a position where is moved by 10 strokes, the impact force becomes the maximum impact force lff1ax. When printing on one sheet of printing paper, the printing paper and printing wire 2
The distance from the printed end of No. 7 is 11 (No < 11 ), and the wire holder 29 is connected to the tip 25H of the armature 25.
Since the printing wire 2 is separably supported by
Only 7 moves by the required stroke f1 by its own inertia while resisting the elastic force of the return spring 31, and hits the printing paper with its printing end. Therefore, the impact force of the printing wire 27 on the printing paper is the maximum impact force l
The impact force Ia is lower than wax.

Next, we will explain the case of printing on printing paper made by stacking four sheets of paper, which are usually used for slip paper, etc. When an excitation current is applied to the coil 9 according to the printing data, the rotation of the armature 25 causes the printing to occur. The wire 27 is operated for printing. At this time, since the distance between the printing paper and the printing end of the printing wire 27 is 12 (fio>12), as shown in FIG. The impact force is lb which is larger than the impact force. Therefore, clear printing can be obtained on the third and fourth sheets of paper without dot handling or blurring.

In this way, in this embodiment, when printing on one sheet of printing paper, the printing wire 27 is connected to the tip end 25a of the armature 25.
The impact force of the printing wire 27 becomes an impact force Ia lower than the maximum impact force IWaX because the printing paper is struck while being separated from the wire and moving by the inertia of the wire itself. Therefore print ji! Damage to the print wire 27 and print ribbon can be reduced as well as noise.

In addition, when printing on printing paper made by stacking multiple sheets of paper such as slip paper, the printing paper is struck while the printing wire 27 moves together with the tip 25a of the armature 25, so the printing wire The impact force of No. 27 is an impact force lb higher than the impact force la when printing on one sheet of printing paper.

Therefore, it is possible to print clearly on all sheets of paper without causing missing dots or blurring.

[Effects of the Invention] Therefore, the present invention can reduce printing noise when printing on a single sheet of printing paper or thin printing paper, and can also reduce damage to the printing wire and printing ribbon. Furthermore, when printing on a plurality of sheets of printing paper stacked one on top of the other, it is possible to provide a print head that can print clearly on all sheets of paper.

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing a print head according to the present invention;
FIG. 2 is a longitudinal cross-sectional view of the center of the road body shown in FIG. 1, FIG. 3 is a perspective view showing the attachment state of the printing wire to the armature, and FIG. 4 is an explanatory view showing the operation. In the figure, 1 is a print head, 3 is a yoke, 7 is a core that forms part of the electromagnet, 9 is a coil that forms part of the electromagnet, 1
5 is a frame, 25 is an armature, 25a is a tip, 2
7 is a printing wire, and 29 is a wire holder as a movable member. Patent Applicant Brother Industries, Ltd. Agent Patent Attorney Ken Ito - Figure 3. Procedural Amendment (Method) for 4 Impact Forces December 1, 1986

Claims (1)

[Claims] (1) A yoke in which a large number of electromagnets are arranged, an armature arranged to face each electromagnet, and a frame that rotatably supports one end of each armature between the end face of the yoke. a printing wire that is separably supported from the other end of the armature and whose head is struck by the other end of the armature that rotates by the action of an electromagnet to perform a printing operation; a platen that supports printing paper; In a printing head supported at a predetermined interval, when printing on a plurality of sheets of printing paper by overlapping them, the printing operation is performed with the printing wire moving together with the other end of the armature, The rotation amount of the armature is set so that when printing on a single sheet of printing paper, the printing operation is performed while the printing wire is separated from the other end of the armature and moved by the inertia of the wire itself. print head.