JPS59229350A - Dot printer - Google Patents

Abstract

PURPOSE:To make it possible to reduce printing noise, by a method wherein the magnetic ink in a tank is attracted between mutually opposed magnetic poles and a needle contacted with this magnetic ink layer is operated to adhere the magnetic ink to recording paper. CONSTITUTION:When a current is supplied to a magnetic ink attracting coil 16, the magnetic ink in a tank 20 is attracted by magnetic flux generated between magnetic poles 19 and the magnetic ink layer is formed along a slit 18 to wet the leading end parts of needles 9. When a printing head 2 is driven and the needles 9 are protruded toward recording paper corresponding to a printing signal, the magnetic ink adhered to the leading ends of the needles 9 is contacted with the recording paper to perform dot printing. In this case, because dots can be formed by soft-touch, no impact sound is generated and noise is reduced. In addition, the magnetic ink in the tank 20 is replenished from a cartridge 21 corresponding to an ink consumption amount.

Description

[Detailed description of the invention] Technical field of invention This invention relates to a dot printer.

Technical background of the invention and its problems Conventional dot printers impact pressure-sensitive paper along a platen with a needle, or impact plain paper with an ink ribbon. In either case, printing is caused by collision between the needle and the platen, which causes a lot of noise.

For this reason, we developed a method in which all magnetic poles are placed facing each other in front of the platen, magnetic ink in the ink tank is attracted between these magnetic poles by magnetic force, and a needle that penetrates the attracted magnetic ink layer is brought into contact with the recording paper. is being considered. However, the level of magnetic ink in the ink tank fluctuates due to factors such as consumption and evaporation, and even if the magnetic force is constant, it is difficult to attract magnetic ink at a constant height to the needle position, and it is difficult to draw magnetic ink at a constant height from the needle far from the ink tank. A situation may also occur in which the ink does not touch the ink layer. Ink must also be replenished frequently.

Purpose of the Invention This invention was made in view of the above points, and it is possible to attract magnetic ink to a certain level between the magnetic poles where the needle exists, and furthermore, it is possible to reduce the frequency of manually replenishing magnetic ink. The purpose is to hang a dot printer.

SUMMARY OF THE INVENTION This invention attracts magnetic ink in an ink tank between opposing magnetic poles, operates a needle that touches the magnetic ink layer between the magnetic poles, and adheres the magnetic ink attached to the needle to recording paper. , it is possible to reduce the printing pressure on the recording paper and extremely reduce printing noise, and
The magnetic force attracts the magnetic ink in the ink tank, and the cartridge replenishes the ink tank with magnetic ink at a constant level, so that the needle attracts the magnetic ink to a constant level between the magnetic poles. In addition, by providing a magnet in the ink tank below the magnetic poles, when printing is completed after cutting off the magnetic circuit including the magnetic poles, the magnetic ink between the narrow magnetic poles can be quickly returned to the ink tank, and the magnetic ink The structure is such that it is possible to avoid the situation where the particles dry while remaining attached to the magnetic poles.

Examples of the invention An embodiment of the present invention will be described based on the drawings.

(1) is a housing, and this housing (1) has a print head (2).
The carrier (3) with 4 iV is connected to the carrier shaft (4
) and a guide shaft (5) so as to be slidable. A cover (6) is provided on the top surface of the housing (1), although only a portion thereof is shown. The print head (2) is equipped with a plurality of electromagnets (7)'k, a magnet case (8) arranged in a ring, and a plurality of needles (9).
It consists of a fully held guide frame αO. Each electromagnet (
The armature αη of 7) comes into contact with the needle (9), is urged in the backward direction by the needle spring α2, and is pressed against the stopper 0]. Guide frame α0 is a needle guide α4Q that aligns the needles (9)! 19 is fixed, and magnetic plates α force magnetically coupled to both poles of a magnetic ink suction coil fG are fixed on both sides of this guide frame Qo), and a slit 0 is provided at the tip of these magnetic plates αη.
Two magnetic poles facing each other are formed in succession, with the tip of the needle (9) protruding from the slit.

Further, a flat ink tank (E) and a cartridge Q are detachably attached to the print head (2). A slit-like small hole Q4 into which the lower end of the magnetic pole α9 is inserted and a through hole (C) located in the center are continuously formed on the top surface of the ink tank handle, and an opening (C) for replenishing magnetic ink (C) is formed in series. c) is formed. A permanent magnet (c), which is a magnet facing the lower end of the magnetic pole (l), is fixed to the bottom surface of the ink tank (c).
A cylinder (A) that fits into the opening (C) is formed on the lower surface of the cylinder (C), and an opening (C) is formed at the lower end of this cylinder (C) to discharge the magnetic ink (C) inside. Inside the hole (b), there is a plug (c) that closes the opening (c) when it is in close contact with the spring (g).
It is urged downward and fitted so that it can freely move up and down.

Further, a rod 0]) is formed protruding from the lower surface of this plug (c), and a plurality of notches 02 are formed on the outer periphery. The radius 1l-1' of the circle connecting the bottoms of these notches 02 is also larger than the radius of the opening (c).

In addition, paper feed roller 03 is installed in front of the print head (2).
A recording paper 0→ to be fed is supported by a permanent magnet 09.

In such a configuration, when the magnetic ink attraction coil αG is energized, the magnetic ink (c) in the ink tank (a) is attracted by the magnetic flux generated between the magnetic poles 00, and a magnetic ink layer is formed along the slit 0 barrel, and the needle The tip of (9) gets wet with magnetic ink (c). Therefore, the specified electromagnet (7) is fully excited and the needle (9)' is moved from the recording paper 0 to
By ejecting the magnetic ink (c) at the tip of the needle (9) to the recording paper 0→, a drab is formed.

In this case, if the tip of the needle (9) lightly touches the recording paper (B), a dot is formed, so there is no collision sound as in the conventional case, and the noise is extremely low. According to this embodiment, when the tip of the needle (9) approaches the recording paper 0, the needle (9)
) The magnetic ink (c) at the tip is attracted by the magnetic pole 0, so
It is also possible to further reduce printing noise by setting the stroke of the needle (9) to a small stroke that does not bring it into contact with the recording paper 0→.

In addition, the magnetic force of the magnetic ink attraction coil is constant,
The magnetic ink (c) in the ink tank is replenished from the cartridge Q1) according to the consumption amount, so it is maintained at a constant level. Therefore, the level of the magnetic ink layer at the slit α→ is also constant, and the upper needle (9) There is no situation in which the magnetic ink (c) does not reach. Furthermore, due to the presence of the cartridge (c), there is no need for manual replenishment of the ink tank, which saves time and effort. Cartridge D
When putting magnetic ink (c) into l), use cartridge @
Pull it out 1m upwards. At this time, since the rod 0◇ separates from the bottom of the ink tank (C), the stopper (C) slides under the force of the spring (G) to close the opening (C). This prevents the remaining magnetic ink (c) from flowing out.

Then, with the opening (c) of the cartridge Q) facing upward, press the stopper e, and pour the magnetic ink (c) through the opened opening (c).

At the end of printing, the power to the magnetic ink attraction coil 0Q is turned off. If the slit α→ is not narrowed, it will be difficult to form a magnetic ink layer, so even if the electricity is turned off, the magnetic ink (c) will not easily return to the ink tank holder, but the magnetic ink (c) in the slit α→ By determining the magnetic force of the permanent magnet (C) in the through hole (C) by taking into account the own weight and surface tension of When the magnetic ink (c) is completely returned to the slit 0, the groove where the magnetic ink (c) is attached will not harden. This makes it possible to make the through hole (c) as small as possible to suppress evaporation of the magnetic ink (c) when not in use. Permanent magnet (c) is from Ink Tank Co., Ltd.
The magnetic ink (C) inside is attracted from the surroundings to raise the level of the part facing the magnetic pole αIk from the surroundings, and thereby, when the magnetic ink attraction coil αe is excited during printing, the magnetic ink (C) is raised. make it easier However, since the magnetic ink (C) must be returned downwards when printing is finished, the level of the magnetic ink (C) below the magnetic pole 0 must be permanently maintained so that there is some distance between it and the through hole (C). The mounting height and magnetic force of the magnet (c) are determined. In addition, permanent magnets (
An electromagnet may be used instead of c).

Effects of the Invention Since the present invention is configured as described above, it is possible to reduce the printing pressure on the recording paper and to make the printing noise extremely small. The level of the magnetic ink layer can be kept constant throughout, reducing the frequency of manual replenishment of magnetic ink.Furthermore, when printing is completed, the magnetic ink between the magnetic poles can be quickly returned to the ink tank using a magnet. This has the effect of preventing the magnetic ink from hardening once it has adhered to the magnetic pole.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the whole with a part cut away and reduced in size, FIG. 2 is a plan view, and FIG.
The figure is a vertical side view, Figure 4 is an exploded perspective view, Figure 5 is a partially cutaway enlarged front view showing the connection between the ink tank and cartridge, and Figure 6 is an enlarged view of the cartridge stopper. FIG. 9... Needle, 16... Magnetic ink suction coil,
18...Slit, 19...Magnetic pole, 20...Ink tank, 21...Cartridge, 24...Magnetic ink, 26...Permanent magnet (magnet) Applicant: Tokyo Electric Co., Ltd. Nimo Z diagram

Claims (1)

[Claims] 1. Provide magnetic poles that are coupled to a magnetic ink attraction coil and face each other with a slit open, the lower ends of these magnetic poles are inserted into an ink tank and immersed in the magnetic ink in the ink tank, A plurality of needles that capture the magnetic ink attracted between the magnetic poles (by magnetic force) and transfer it to recording paper are slidably provided between the magnetic poles, and the ink tank is replenished with magnetic ink at a fixed level. A dot printer characterized by a removable cartridge. 2. Provide magnetic poles that are connected to a magnetic ink attraction coil and face each other with a slit spaced between them, and insert the lower ends of these magnetic poles into an ink tank and immerse them in the magnetic ink in the ink tank, so that the magnetic force creates a gap between the magnetic poles. A plurality of needles that capture the attracted magnetic ink and transfer it to recording paper are slidably provided between the magnetic poles, and a cartridge that replenishes the ink tank with magnetic ink at a fixed level is detachably provided, A dot printer characterized in that a magnet facing the lower part of the magnetic pole is attached to the ink tank.