JPH0324347B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention This invention forms dots by bringing the tips of selectively driven needles into contact with recording paper, and prints characters, etc. with a collection of these dots. This invention relates to ink dot printers.

Technical background of the invention and its problems In general, there are wire dot printers, thermal printers, etc. as dot printers, but among these, wire dot printers that print by selectively driving needles do not allow the needles to collide directly with pressure-sensitive paper. , the needle collides with the recording paper with a printing ribbon interposed. Therefore, the noise is extremely loud.

Therefore, a method has been proposed in which polar ink is attached to the tip of a needle and the needle is selectively driven to bring the tip into contact with the recording paper. However, in such devices, a large amount of polar ink exists between the needles, so when adjacent needles are driven simultaneously, this large amount of magnetic ink is transferred to the recording paper and spreads, forming large dots in some areas. The disadvantage is that it cannot print clearly.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an ink dot printer that can print clearly even when adjacent needles are driven simultaneously.

Summary of the Invention This invention provides a step or taper with a gap that prevents polar ink from being buried between the tips of the needle when the tips of the needle are brought into contact with recording paper. There is no polar ink between the needles, and only the magnetic ink attached to the tip of the needle is transferred to the recording paper, preventing the formation of large dots in some areas even when adjacent needles are driven at the same time. It is designed to enable clear printing.

Embodiment of the Invention An embodiment of the invention will be described based on FIGS. 1 to 6. First, record paper 2 is placed on platen 1.
A carriage 4 is provided in front of the platen 1 and reciprocated along a guide shaft 3 installed parallel to the platen 1. A drive wire 5 is connected to the carriage 4, and the drive wire 5 is wound around a drive pulley 7 of a carriage motor 6 and a driven pulley 8 spaced apart from the drive pulley 7.

A needle head 9 and an ink film forming body 10 are attached to the carriage 4. The needle head 9 has a head portion 11 in which a plurality of needle magnets (not shown) serving as a driving portion are arranged.
A plurality of needles 12 driven by the needle magnet are biased in the return direction. Tips 1 of these needles 12
3 are arranged vertically, and the needles 12
It is formed into a thin shape by cutting or the like along the axial direction. Furthermore, there is a gap 1 between the tips 13 of these needles 12 that is spaced so that magnetic ink, which will be described later, will not be filled due to capillary action.
4 is formed.

Here, the interval in which the magnetic ink is not filled refers to a state in which the magnetic ink adheres to only one needle 12 due to its viscosity. In other words, the thick part of the needle 12 has a continuous interval due to the viscosity of the magnetic ink, so that the magnetic ink can be smoothly supplied, and the thin part at the tip of the needle 12 has only one needle 12. The polar ink is applied to the paper.

Next, the ink film forming body 10 has an electromagnetic coil 15 above it, and side walls 18 integral with magnetic poles 17 facing each other and forming a magnetic field slit 16 are coupled to both ends of the electromagnetic coil 15. There is. The tip 13 of the needle 12 extends into the magnetic field slit 16, and the magnetic pole 17
The tip extends into an ink replenishment chamber 20 in which magnetic ink 19 is stored.

In such a configuration, when the electromagnetic coil 15 is energized, the magnetic ink 19 stored in the ink replenishment chamber 20 is attracted into the magnetic field slit 16, and a magnetic ink film 21 is formed. Further, magnetic ink 19 adheres to the tip 13 of the needle 12 located within the magnetic field slit 16.

Then, one of the needles 12 is driven based on the print command, thereby transferring the magnetic ink 19 attached to the tip 13 of the needle 12 onto the recording paper.
This is repeated to form dots, and characters, etc. are printed by repeating this process. At this time, adjacent needles 12 may be driven at the same time, but since a gap 14 is provided between the needles 12 at a distance that prevents the magnetic ink 19 from being filled due to capillary action, the gap between the adjacent needles 12 is There is no magnetic ink 19 present on the recording paper, and only the magnetic ink 19 attached to the tip 13 of the needle 12 is transferred to the recording paper. Therefore, even if adjacent needles 12 are driven at the same time, clear printing can be performed without forming large dots locally.

Note that, as shown in FIGS. 7 to 9 as an example, the gap 14 may be formed by forming the tip 13 of the needle 12 into various shapes, and the gap 14 may be formed as shown in FIGS. 10 and 11. Similarly, even when a prismatic needle 12 is used, the tip portion 13 is formed thin and a gap 14 is formed. Furthermore, the gap 14 between the tips 13 of the needles 12 that is not filled with the magnetic ink 19 can be formed by widening the gap between the tips of the needles 12 without making them narrow. The tip of the needle 12 does not have to be made thin, but can also be formed by coating the peripheral surface of the tip with a liquid repellent. Note that when the circumferential surface of the tip of the needle 12 is coated with a liquid repellent, the magnetic ink 19 adheres only to the end surface of the tip of the needle 12 that contacts the recording paper 2, so the dot does not spread and clear printing is possible. can be done.

Effects of the Invention As described above, the present invention forms a magnetic ink film using magnetic ink, and is driven by a drive unit to bring the tip of the magnetic ink film to which the magnetic ink is attached into contact with a recording paper. The needles are arranged close to each other, and a step or taper is used to create a gap between the tips of these needles that will not be filled with the magnetic ink when the tips come into contact with the recording paper. When the tips of the needles are brought into contact with the recording paper, the magnetic ink does not get buried between these tips, so even if adjacent needles are driven at the same time, only the magnetic ink attached to the tips of the needles can be transferred to the recording section. transcribed into
This has the effect of preventing large dots from being formed locally and making it possible to print clearly.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view thereof, and FIG. 3 is a plan view thereof.
FIG. 4 is a side view thereof, FIG. 5 is a perspective view of the needle, FIG. 6 is a side view of the needle, and FIGS. 7 to 11 are perspective views showing modified examples of the needle. 2...Recording paper, 12...Needle, 13...Tip, 14...Gap, 19...Magnetic ink, 21
...Magnetic ink film.

Claims (1)

[Claims] 1. A polar ink film is formed using magnetic ink, and a plurality of needles are driven by a drive unit to bring the tips of the polar ink films to which the magnetic ink is adhered into contact with the recording paper, and the magnetic ink is spread between the needles. Due to their viscosity, the needles are arranged in close proximity so that they are continuous, and when the tips of these needles are brought into contact with the recording paper, the polar ink adheres to only one needle due to its viscosity. An ink dot printer characterized by having a stepped portion or a taper that forms a gap that provides an interval of .