JPH04249160A - Printing head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a print head for a wire dot printer, and in particular, the print head is printed by a sub-electromagnet with a minute delay in the wire drive timing caused by the suction or release of the electromagnet. The present invention relates to a printhead capable of suction. [0002] Recently, wire dot printers have high utility value as serial impact printers due to their copying ability, and are often used to print multiple copies of slips, etc. However, there has been a demand to increase the number of copies. There is a need for a method to meet this need. 2. Description of the Related Art FIG. 5 is a perspective view showing an outline of a wire dot printer. As shown in the figure, a carrier 4 carrying a platen 1, a print head 2, and a ribbon cassette 3 is rotatably supported at both ends, and the front end of the carrier 4 is fixed and hung on left and right pulleys P1 and P2. Consists of a timing belt (hereinafter referred to as belt) B1, a guide shaft 5 to which a carrier 4 is slidably fitted, a tractor (not shown) and a paper guide 7 that transports printing paper 6a supplied from the outside to the front of the print head 2. has been done. The platen 1 and the tractor move the printing paper 6a in the direction of arrow A in conjunction with each other by driving a motor (not shown). Pulley P1 is connected to space motor M1, and belt B is rotated by forward and reverse rotation of space motor M1.
1 moves left and right, and a print head 2 mounted on a carrier 4 reciprocates on the front surface of the platen 1 in the directions of arrows B and C. [0005] An ink ribbon 30 is endlessly stored in the ribbon cassette 3 and is cyclically supplied to the front surface of the print head 2 . With this configuration, the printing paper 6a transported by the tractor is guided by the paper guide 7 and wrapped around the platen 1, and printing is performed by the print head 2 while the carrier 4 moves. [0006] When printing for one line is completed, the printing paper 6a
A predetermined line feed is performed, the moving direction of the carrier 4 is reversed, and printing is performed in the same manner. There are two types of print heads: a suction type and a release type, which will be explained below with reference to FIGS. 6 and 7. FIG. 6 shows a suction type print head 2a, and FIG. 7 shows a release type print head 2A. As shown in FIG. 6(a), the print head 2
In a, a plurality of wire magnets 20a, 20b, -- are arranged radially with wires 21a, 21b, -- at the tips of armatures 25a, 25b, -- arranged in the center. (Only the wire magnet 20a is shown in the figure.) Figure 6(b) shows the wire magnets 20a, 2.
A side view of the wire magnet 20a is shown as a representative of 0b, -. The wire magnet 20a is a wire 21a
, an electromagnet 22a consisting of an iron core 23a and a coil 24a, an armature 25a, a yoke 26, and a spring 27a. The armature 25a has a wire 2 at its tip.
One end of 1a is fixed and rotatably attached to the upper end of yoke 26. Under normal conditions, the end face of the iron core 23 and the armature 2 are pulled by the elasticity of the spring 27a.
A predetermined gap is formed between 5a. This gap corresponds to the drive stroke of the wire 21a. With such a configuration, the coil 24
The electromagnet 22a is excited by energizing a, the armature 25a is attracted to the end face of the electromagnet 22a, the tip of the wire 21a rushes in the direction of arrow D, and the wire 21a
Due to the impact, the ink of the ink ribbon 30 is transferred to the printing paper 6a, and printing is performed. As shown in FIG. 7(a), the print head 2A includes a plurality of wire magnets 20A.
, 20B, - have armatures 25A, 25B in the center,
The wires 21A, 21B, and -- at the tips of -- are arranged radially. FIG. 7(b) shows a wire magnet 20A.
, 20B, ─ is shown as a side view of the wire magnet 20A. The wire magnet 20A includes an electromagnet 22A consisting of a wire 21A, an iron core 23A, and a coil 24A, an armature 25A, and yokes 26A, 26.
B, a spring 27A, and a permanent magnet 28A. The armature 25A is swingably connected to the end of the yoke 26B by a spring 27A, and one end of a wire 21A is fixed to the tip of the armature 25A. Under normal conditions, the armature 25A is attracted to the end face of the iron core 23A by the attractive force of the permanent magnet 28A against the elasticity of the spring 27A. The return dimension of armature 25A by spring 27A corresponds to the drive stroke of wire 21A. With such a configuration, the permanent magnet 2
When the electromagnet 22a is excited by energizing the coil 24A in a direction that cancels the attraction force of 8A, and the attraction force of the permanent magnet 28A is canceled, the armature 25A
is released by the restoring force of spring 27A, and wire 2
1A rushes in the direction of arrow D, and the impact of the wire 21A transfers ink from the ink ribbon 30 onto the printing paper 6a.
The image is transferred and printed. When copying multiple sheets of printing paper 6a, pressure-sensitive paper is usually used, and the first sheet is printed as described above, but the second and subsequent sheets are colored and printed by the pressure caused by the impact of the wire. Ru. Therefore, it is possible to make copies up to the number of sheets that can be affected by the impact force. [0015] According to the above conventional method, wire dot printers have a high value in use because they print dots by impact and have a copying ability, but in recent years, the number of copies made has decreased. There have been many requests to increase the number of To increase the number of copies, it is necessary to strengthen the impact of the wire, and one way to achieve this is to increase the size of the electromagnet in a suction type printing head, and to increase the size of the electromagnet, permanent magnet, and spring in a release type printing head. There is. However, as the size of the members increases, the print head naturally becomes larger, which goes against the demand for miniaturization of printers, so there is a problem in that this method cannot be adopted. SUMMARY OF THE INVENTION An object of the present invention is to provide a print head that can increase the number of copies by accelerating the wire drive and increasing the impact. [Means for Solving the Problems] FIG. 1 is a diagram showing the principle of the present invention. In the figure, 6 is a print medium, 21 is a wire, 2
5 is at least one armature with one end of the wire 21 attached to its tip; 22 is the same number of first electromagnets corresponding to at least one armature 25; A second magnet that attracts the armature 25 by being excited after a predetermined time delay from the timing when the wire 21 is driven by attraction or release.
It is an electromagnetic magnet. Therefore, by selectively energizing the first electromagnet 22, the corresponding armature 25 is attracted, or the corresponding armature 25 attracted to the permanent magnet is released, and the wire 21 is driven after a predetermined time delay. The armature 25 is attracted by the excited second electromagnetic magnet 29, and dots are printed on the print medium 6 by the tip of the wire 21. [Operation] Selectively energizes the same number of first electromagnets 22 corresponding to at least one armature 25 to attract the armature 25, or release the armature 25 attracted to the permanent magnet, so that the wire When the second electromagnet 29 is excited after a predetermined time delay from the timing of driving the wire 21, the driving of the wire 21 which has started to be driven by the excitation of the first electromagnet 22 is accelerated, thereby increasing the impact force of printing. Therefore, the number of copies of the print medium 6 can be increased. Furthermore, since the second electromagnet 29 can be used in common with a plurality of first electromagnets 22, there is no need to increase the space, or the number of copies can be increased with only a slight increase in the space. Can be done. [Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. The same reference numerals indicate the same objects throughout the figures. FIG. 2 shows a configuration diagram of an embodiment in which the present invention is applied to the suction type print head described in the conventional example. Printing paper 6a and electromagnets 22a, 2 in FIG.
2b, ─, and the electromagnet 29a are the print medium 6, in FIG.
They correspond to the first electromagnet 22 and the second electromagnet 29, respectively. As shown in the perspective view of FIG. 2(a), a ring-shaped iron core 30a and a coil 3
An electromagnet 29a (consisting of 1) is provided in common to the wire magnets 20a', 20b', -, and wires 21a, 21b, - are arranged in the center hole. The wire magnet 20a' is shown as a representative in the side view of FIG. 2(b), and the electromagnet 29a is attached to the tip of the yoke 26a,
It is formed to have the same length as b, -. In the figure, the iron core 30a
Although the coil 31 is shown as being wound around the outer surface of the ring-shaped iron core 30a, the coil 31 is actually wound around the outer side of the ring-shaped iron core 30a. In the control block diagram of FIG. 3(a), 32 is a control section, 33 is a timer, 34 is a time setting section, and 35 and 36 are magnet drivers. When the control unit 32 drives the print head 2A based on print information, the control unit 32 first activates the electromagnets 22a, 2 of the wire magnets 20a', 20b', ─ corresponding to the dots of the character pattern.
2b, ─ to the magnet driver 35 to excite it (
At the same time, the timer 33 is started and the magnet driver 36 is activated when the predetermined time T2 is counted, as shown in the time chart of FIG. 3(b).
command to excite the electromagnet 29a (excitation time T1-T2
) let. The timer 33 is activated by a command from the control unit 32 and is activated for a predetermined period of time (for example, 50 seconds) set in the time setting unit 34.
μs) T2 is counted and notified to the control unit 32. Having such a configuration and function, the wire magnets 20a', 20b', ─ and electromagnets 22a, 22b, ─
For example, when the timer 33 that started the excitation starts counting a predetermined time T2, the electromagnet 29a is excited and the armature 25a that is being attracted is selectively energized depending on the character pattern to be printed. 25a is further attracted and accelerated, and wire 2
The impact force of 1a can be increased, and the number of copies can be increased. A different embodiment is shown in FIG. 4, and FIG. 4 is a block diagram of an embodiment in which the present invention is applied to the open type print head described in the conventional example. Printing paper 6 in Figure 4
a, electromagnets 22A, 22B, --, and electromagnet 29b
correspond to the print medium 6, the first electromagnet 22, and the second electromagnet 29 in FIG. 1, respectively. As shown in the perspective view of FIG. 4(a), a ring-shaped iron core 3 is located at the center of the print head 2B.
Electromagnet 29b consisting of 0A and coil 31A connects electromagnets 22A, 22 to armatures 25A, 25B, -.
Wire magnet 20A', 20 on the opposite side of B, ─
B', ─ is provided in common, and the wire 21A is installed in the center hole.
, 21B, -- are arranged. As shown in the side view of FIG. 4(b), a wire magnet 20A' is shown as a representative, and an electromagnet 29a is attached to the tip of a yoke 26c provided on the opposite side of the yoke 26b with respect to the spring 27a. attached. When the armature 25A is attracted to the electromagnet 22A, the gap between the end face of the electromagnet 29b and the armature 25A corresponds to the driving stroke of the wire 21A. The control block diagram and time chart are for the electromagnets 22a, 22b,
This is the same as replacing the electromagnet 29a with the electromagnets 22A, 22B, 22A, 22B, and the electromagnet 29b, so the explanation is omitted. With such a configuration, the wire magnets 20A', 20b', - electromagnets 22A,
For example, when armature 25A starts to be released and the timer 33 that started excitation counts a predetermined time T2, electromagnet 29A is energized and released. The armature 25A, which is being printed, is further accelerated by suction on the opposite side, thereby increasing the impact force of the wire 21A, thereby increasing the number of copies. In this way, in the case of a suction type print head, the common electromagnet 29a can be placed in the empty space surrounded by the radially arranged electromagnets 22a, 22b, -, and the space can be effectively used. By using
The number of copies of the print paper 6a can be increased without increasing the size of the print head 2A, and in the case of a release type print head, an electromagnet 29b is installed in the thickness direction of the print head 2B.
By simply increasing the space for arranging the yoke 26c,
An increase in the diameter of the print head 2B is avoided, and the print paper 6
The number of copies of a can be increased. [0032] As explained above, according to the present invention, by selectively excitation of the first electromagnet, the corresponding armature is attracted, or the corresponding armature attracted to the permanent magnet is released. , the armature is attracted by a second electromagnetic magnet that is excited after a predetermined time delay from the timing at which the wire is driven, and the tip of the wire prints dots on the printing medium 6, thereby accelerating the driving of the wire and printing. Since the impact force can be increased, the number of copies of the print medium can be increased without increasing the size of the print head.

[Brief explanation of the drawing]

[Figure 1] Principle diagram of the present invention

[Figure 2] Block diagram showing an embodiment of the present invention

[Figure 3]
Explanatory diagram of the example

[Figure 4] Configuration diagram showing different embodiments

[Fig. 5] A perspective view showing an outline of a printer to which the present invention is applied.

[Figure 6] Configuration diagram showing a conventional example of a suction type print head

[
Figure 7: Configuration diagram showing a conventional example of a release type print head

[Explanation of symbols]

6 is a printing medium, 6a is a printing paper,
21, 21a, 21b, 21A,
21B is a wire, 22 is a first electromagnet, 22a, 22b, 22A, 22B, 22A', 22B
', 29a, 29b are electromagnets, 25, 25a, 25b,
25A, 25B are armatures, 28A
is a permanent magnet, 29 is a second electromagnet,

Claims (2)

[Claims] 1. The same number of first electromagnets (22) corresponding to at least one armature (25) each having one end of a wire (21) attached to its tip end are paired,
By energizing the first electromagnet (22), the armature (25) is selectively attracted, or the armature (25) attracted to the permanent magnet is selectively released, thereby driving the wire (21). The print head prints dots on a printing medium (6) using the tip of the wire (21), and the wire (21) is attracted or released by the excitation of the first electromagnet (22).
A second electromagnet (21) is excited after a predetermined time delay to drive the armature (25) and attracts the armature (25).
9) A print head comprising: 2. The second electromagnet (29) is connected to the armature (25) and the first electromagnet (2
2. The print head according to claim 1, wherein the print head is provided in common for a plurality of sets of 2).