JPS6038174A - Dot printer - Google Patents

Abstract

PURPOSE:To provide a dot printer capable of performing printing with uniform density by extremely reducing the density change of ink, by specifying the width of the slit between a pair of magnetic poles through which the leading ends of needles arranged in a line form are protruded and retracted, and providing a magnetic ink supply part above the interval of said slit. CONSTITUTION:A plurality of needles 10 driven by an electromagnet are provided so as to arrange the leading ends thereof in a line form. A pair of magnetic poles 14, 14 are opposedly provided so as to open a slit 13 through which the leading end parts of said needles 10 can be protruded and retracted and magnetically coupled with both poles of an electromagnetic coil 11. In this case, it is pref. to respectively mount guide lines 16, 16 to both magnetic poles 14, 14. An ink tank 17 is provided to the upper part of the slit 13 to supply magnetic ink. The width of the slit 13 is determined to such a dimension that the magnetic ink is fallen under its own wt. when a magnetic field between the magnetic poles 14, 14 disappears.

Description

Detailed Description of the Invention Technical Field of the Invention The present 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 needles or The needle impacts the paper through the ink ribbon, and the impact is loud.

For this reason, a pair of magnetic poles are placed facing each other at the tip of the print head, and the lower end of the slit between these magnetic poles is connected to the ink tank, and the magnetic ink in the ink tank is attracted to the slit by the magnetic field between the magnetic poles. There is a method in which a film is formed by passing a needle through the film, and -C magnetic ink is transferred from the tip of the needle to recording paper.

However, after using such a line, the magnetic ink in the slit, which has a large contact area with the outside air, is returned to the ink tank at the bottom, and the ink tank is communicated with the slit, so that when not in use, the magnetic ink covers the entire liquid surface. Since the magnetic ink is exposed to the outside air, the solvent of the magnetic ink tends to evaporate, thus increasing the concentration of the magnetic ink, and the disadvantage is that solidified magnetic ink particles tend to accumulate in the areas where the magnetic ink comes into contact. Further, in the case where an ink tank is provided below the slit, the level of magnetic ink inside gradually decreases, so the level of magnetic ink in the slit also decreases. To compensate for this, it is necessary to add another ink tank to replenish magnetic ink to the lower ink tank.

Purpose of the Invention The present invention has been made in view of the above points, and an object thereof is to provide a dot printer that can reduce changes in the concentration of magnetic ink and maintain the supply of magnetic ink to the slits at a certain level. It is.

Summary of the Invention This invention uses magnetic force to attract magnetic ink to a slit between opposing magnetic poles, passes a needle through the magnetic ink film of the slit, and transfers the magnetic ink onto recording paper. By doing so, the area in which the magnetic ink inside the ink supply unit comes in contact with the outside air is significantly reduced, and after use, the magnetic field between the magnetic poles is removed and the magnetic ink between the magnetic poles is moved downward, thus reducing the amount of magnetic ink supplied to the slit. Printing a with extremely small manufacturing changes
Furthermore, since magnetic ink is consumed over time, it is supplied from the top of the slit, so a constant amount of magnetic ink can be supplied to the slit regardless of the amount of ink consumed. Therefore, an ink tank for replenishment is omitted, a guide strip is provided along the inner edge of the magnetic pole to allow the magnetic ink between the slits to fall without scattering it around, and an ink receiver is provided. The magnetic ink is placed at the bottom of the magnetic pole to collect the magnetic ink, thereby completely preventing the surrounding area from becoming contaminated.

Examples of inventions An embodiment of Jin's invention will be described based on the drawings.

The housing (1) has a carrier (
3) is the carrier shaft (4) and guide shaft (5)
It is held in and slidably provided. Housing (
1) A cover (6) is provided on the top surface, although only a portion thereof is shown. The print head (2) is mounted on a guide frame (8) on which a mounting flange (7) for the carrier (3) is formed.
) and a magnet case (9) connected to this guide frame (8), a plurality of needles Ql are slidably held in the guide frame (8), and the needles Ql are held in the magnetic case (9). Individually driven electromagnets (not shown) are housed therein.

And on both sides of the guide frame (8) there is an electromagnetic coil α.
A magnetic plate Q4 magnetically coupled to both poles of υ is fixed.A magnetic pole α4 facing each other with a slit αa+ is formed on these magnetic plates a2 by bending. These magnetic poles I have a conical protrusion QS that tapers toward the lower end and a guide protrusion αQ along the inner edge.

Next, an ink tank aη, which is an ink supply unit, is detachably attached to the upper part of the guide frame (8), and the upper end of the magnetic pole a4 is inserted into the lower surface of this ink tank αη, which stores the magnetic ink Qi (sliding). (The ink supply hole (11) communicating with 13 is formed, and the other parts are sealed. The size of the ink supply hole al is
gI is set to a size that will not drip due to its own weight. The width of the slit is determined so that when no magnetic field is formed between the magnetic poles 04, the magnetic ink (I8) will fall under its own weight. An ink receiver is provided.

In such a configuration, the electromagnetic coil αυ is excited to form a magnetic field across the magnetic pole (14). In this case, the magnetic ink α in the ink tank (17) is attracted toward the slit (131). At this time, the magnetic ink a8 flows along the guide strip (119) and does not scatter to the outside. Also, the lower end of the magnetic pole α4 is far from the electromagnetic coil (111).
Since the magnetic field is also weak, the magnetic dumplings do not reach the fourth protrusion.

In this state, the carrier (3) is moved, the electromagnet in the magnet case (9) is excited, and the needle α1 is driven to perform printing. That is, the needle a8 transfers the magnetic ink barrel forming a film onto the recording paper at the slit a.

After printing is completed, return the carrier (3) to the home position and turn off the power to the xi micromi. As a result, the magnetic ink side of slit α4 is guided by the guide strip (1G) and flows downward without protruding from both sides, and is further guided by the conical projection a!9 and drips into the ink receiver (a). Because the ink tank Oη has no openings other than the ink supply hole Ql and the ink supply hole H itself is small, even if the slit 4 is empty, the magnetic ink u barrel of the ink tank aη is newly opened through the slit. It will not leak to OJ.

In this way, the magnetic ink (
L barrels have a large contact area with the outside air, making it easier for the solvent to evaporate.
．． Since the magnetic ink (L barrel) in the ink tank Uη is not returned to the ink tank and is discarded into the ink receiver, the concentration of the magnetic ink (L barrel) in the ink tank Uη will never become ρ1 (in addition, the ink tank aη
However, the magnetic ink layer, which is constantly exposed to the wide open air, is in an extremely small area corresponding to the ink supply hole a1, and the solvent for the magnetic ink in the ink tank aη. The amount that evaporates into the atmosphere is also extremely small.

Therefore, in this respect as well, the density of the magnetic ink α barrel does not become high, and the printing density can be made uniform.

Also, ink tank a during printing? ) The level of the magnetic ink droplets decreases according to the amount of water, but it is supplied to the system slit α as long as the magnetic ink Q8 is present inside.

Therefore, there is no need to provide an additional ink tank for replenishment in order to keep the level of the magnetic ink (ink tank book) constant per second.

As shown in FIG. 8, for example, by forming an inclined edge (2) on the magnetic pole I, the magnetic path for the electromagnetic coil aυ is lengthened as it goes downwards from the slit u.
Magnetic ink a is created by reducing the strength of the magnetic field as it goes downwards.
By keeping the weight and balance of the peaks constant, and by keeping the film thickness of the magnetic ink mallet constant over the entire slit Ql, it is possible to create a difference in printing density between the upper and lower sides of a single character.

Effects of the Invention Since the present invention is constructed as described above, the magnetic ink in the slit can be directed downward after printing, and the evaporation of the solvent of the magnetic ink in the ink supply section into the atmosphere can be reduced. It is possible to print with no difference in shading by reducing the deformation of the slit, and by supplying the &Ii ink from the top of the slit, the consumption of the magnetic paint progresses and the magnetic ink in the ink supply section is Even if the level of magnetic ink changes, it is possible to supply a small amount of magnetic ink to the slit at a level equal to one foot, thereby eliminating the need for an ink tank for replenishing p. This has the effect of preventing ink from scattering, and furthermore, the ink receiving portion receives the magnetic ink of the slit, thereby preventing staining of the surrounding area.

[Brief explanation of the drawing]

Figures 1 and 2 show examples of the present invention, Figure 1 is a perspective view of the overall configuration with a cutout at -S, Figure 2 is a perspective view of the print head, and Figure 3 is its plan view. , Fig. 4 is a side view thereof, Fig. 5 is a front view thereof, Fig. 6 is a front view of the cross section of the ink tank showing the state of connection between the ink tank and the slit, and Fig. 7 is a plan view of the magnetic pole. FIG. 8 is a front view showing a modification of the magnetic pole. 10... Needle, 11... Electromagnetic coil, 13...
・Slit, 14...Magnetic pole, 16...Guide strip,
17... Ink tank (ink supply section), 18...
Magnetic ink, 20...For ink receiving part Application person Tsukusui Electric Co., Ltd.] δ country part 7 countries

Claims (1)

[Claims] 1. A plurality of needles driven by electromagnets are provided with their tips aligned in a row, a slit is opened through which the tips of the needles are inserted, and a pair of opposing magnetic poles are connected to both poles of the electromagnetic coil. An ink supply unit that is magnetically coupled and supplies magnetic ink is connected to the top of the slit, and the width of the slit is set such that when the magnetic field between the magnetic poles is removed, the magnetic ink between the magnetic poles falls under its own weight. A dot printer characterized by specified dimensions. 2. The dot printer according to claim 1, characterized in that an ink supply section includes an ink tank that extends around the entire circumference, and the ink tank is connected to the upper part of the slit. 3. A plurality of needles driven by electromagnets are provided with their tips aligned in a row, and a pair of opposing magnetic poles are magnetically coupled to both poles of an electromagnetic coil with a slit through which the tips of the needles are inserted. An ink supply section for supplying ink is connected to the upper part of the slit, and the width of the slit is set to a size such that when there is no magnetic field between the magnetic poles, the magnetic ink between the magnetic poles falls under its own weight. A dot printer characterized in that a guide strip for guiding the magnetic ink downward is provided along the edge of the magnetic pole on the slit side.46 A plurality of needles driven by electromagnets are provided with their tips aligned in a row. A slit is formed through which the tip of the needle is inserted, and a pair of opposing magnetic poles are magnetically coupled to both poles of an electromagnetic coil, and an ink supply section that supplies magnetic ink is connected to the upper part of the slit. 5. A dot printer characterized in that the width is set so that the magnetic ink between the magnetic poles falls under its own weight when the magnetic field between the magnetic poles disappears, and an ink receiver is provided opposite the lower end of the magnetic pole. 5. The dot printer according to claim 4, wherein the lower end of the magnetic pole is formed into a conical shape with a tapering end.