JPH0567428B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an ink dot printer that prints characters and figures by depositing ink held by the tip of a needle in dots on recording paper.

Technical Background and Problems of the Invention There are two types of dot printers: impact type and ink dot type.

In the impact type, printing is generally performed by directly impacting pressure-sensitive paper with a needle or indirectly impacting plain paper via an ink ribbon. For this reason, although it has the advantage of being able to make copies using a method such as impacting multiple sheets of pressure-sensitive paper stacked one on top of the other, it has the disadvantage of producing a large amount of noise during printing.

On the other hand, in the ink dot type, printing is performed by depositing ink on recording paper in the form of dots. For example, multiple needles that hold ink at their tips are selectively driven by a drive unit to make them reciprocate, and the tips of the needles are brought into slight contact with the recording paper, or are brought close to each other to cause the ink to fly. There are some that make ink adhere to the recording paper in dots. This configuration has the advantage that printing noise is significantly lower than that of impact type dot printers. However, since the needle prints without impacting the recording paper, it has the disadvantage that it cannot be copied.

Purpose 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 also make copies if necessary.

SUMMARY OF THE INVENTION The present invention is characterized in that a plurality of needles are selectively driven by a drive unit to cause ink held by the tips of the needles to adhere to a recording paper to perform printing, wherein the drive unit Since a driving force switching mechanism is provided to change the driving force of the drive unit, by increasing the driving force of the drive unit, the function of an impact-type dot printer in which the needle impacts the recording paper is provided, and copying can be performed as necessary. It is configured so that it can be done.

Embodiment of the Invention A first embodiment of the invention will be described based on FIGS. 1 to 4. A platen 3 for holding recording paper 2 is provided inside the casing 1, and two guide shafts 4 are provided parallel to the platen 3. A carrier 5 is attached to those guide shafts 4.
is held slidably, and a printing head 6 is fixed to this carrier 5. Furthermore, a cover 7 is provided on the upper surface of the housing 1 to cover the internal mechanism.

Next, the print head 6 will be explained. A plurality of needles 8 are arranged in this print head 6 with their tips aligned in a vertical line, a drive section 9 is provided at the rear end of these needles 8, and an ink supply section 10 is provided at the tip. ing.

The ink supply section 10 supplies magnetic ink 11 to the tip of the needle 8. That is, two magnetic pole plates 13 magnetically connected to the excitation coil 12 are provided with magnetic poles 14 formed at their ends facing each other, and a magnetic field slit 15 is formed between these magnetic poles 14. The lower end of the magnetic pole plate 13 extends downward while forming the magnetic field slit 15, and is inserted into an insertion port 17 formed on the upper surface of an ink tank 16 in which magnetic ink 11 is stored. Furthermore, each part is positioned such that the tip of the needle 8 is located within the magnetic field slit 15.

The drive unit 9 drives the needle 8 to make it move back and forth. A plurality of electromagnets 18 are arranged in an annular manner in the drive section 9, and an armature 20 is attached to these electromagnets 18 with the movable end 19 facing the center. This armature 20
is the movable end 19 in the longitudinal direction of the needle 8.
is provided so as to be movable, and the rear end of the needle 8 is urged by a spring 21 and abuts against this movable end 19 . And those needles 8
A backstopper 22 is provided at a position where the movable end is brought into contact with, and the movable range of the armature 20 is limited between the backstopper 22 and the electromagnet 18.

Further, the driving section 9 is provided with a driving force switching mechanism 23 as shown in FIG. That is,
A drive power source (not shown) is connected to T ₁ and T ₂ , and the electromagnet 18 is connected to T ₃ and T ₄ . and,
A copy switch 24 is provided between T ₁ and T ₃ ,
The route through which the resistor 25 is passed and the route where it is not passed can be selected outside the ink dot printer main body.

In such a configuration, when the excitation coil 12 is energized, the magnetic ink 11 in the ink tank 16
is attracted and supplied into the magnetic field slit 15.
At this time, a magnetic ink layer 26 is formed within the magnetic field slit 15, and the magnetic ink 11 is supplied to the tip of the needle 8 whose tip portion is located within the magnetic field slit 15.

On the other hand, the electromagnet 18 attracts the armature 20 by being selectively energized by the drive power source, and the movable end 19 pushes the rear end of the needle 8, causing the needle 8 to move.
to fly. At this time, the driving force of the electromagnet 18 that causes the needle 8 to fly can be selected by the driving force switching mechanism 23. That is, when the copy switch 24 is set to C ₁ , T ₁ ,
The voltage from the drive power supply connected to T ₂ is applied to the electromagnet 18 without dropping. Further, when the copy switch 24 is set to _C2 , a voltage reduced by the resistor 25 is applied to the electromagnet 18. Therefore, when the copying switch 24 is set to _C1 , the driving force of the electromagnet 18 does not decrease and the needle 8 impacts the recording paper 2. Also, copy switch 2
4 is set to _C2 , the driving force of the electromagnet 18 is reduced, so that the needle 8 only contacts the recording paper 2. In this way, the functions of two types of dot printers, the impact type and the ink dot type, can be obtained simply by switching the copy switch 24. Therefore, when there is only one sheet of recording paper 2, the copy switch 24 is set to _C2 and the needle 8 is brought into contact with the recording paper 2 to print with low noise.When copying is required, the copy switch 24 is turned to C2.
C ₁ and the needle 8 is made to impact the recording paper 2 to make copies possible.

After flying and forming dots on the recording paper 2, the needle 8 is urged by the spring 21 and returns to its original position. These needles 8
By selectively continuing these operations, a collection of dots is formed, and characters and figures are printed.

A second embodiment of this invention will be described based on FIG. The same parts as in the first embodiment are denoted by the same reference numerals and explanations are omitted (the same applies hereinafter). This example is
This relates to the driving force switching mechanism 27, with a driving power source connected to T ₅ and T ₆ , and an electromagnet 18 connected to T ₇ and T ₈ .
is connected. A variable resistor 28 is provided between _T5 and _T7 .

With such a configuration, the variable resistor 28 can steplessly apply resistance to the voltage applied to the electromagnet 18, and the driving force of the driving section 9 can be freely set within a certain range. This provides a dot printer having two types of functions: impact type and ink dot type.

A third embodiment of this invention will be described based on FIG. This embodiment relates to a driving force switching mechanism 29, in which a driving power source is connected to T ₉ and T ₁₀ .
An electromagnet 18 is connected to T ₁₁ and T ₁₂ . A copy switch 24 is provided between T ₉ and T ₁₁ , and a Zener diode 30 is connected in parallel with the electromagnet 18. Note that the voltage applied from the drive power source is set higher than the Zener voltage of the Zener diode 30.

In such a configuration, the copy switch 24 is
When set to _C3 , the voltage from the drive power source is directly applied to the electromagnet 18. On the other hand, when the copying switch 24 is set to _C4 , the Zener voltage is applied to the electromagnet 18, and the driving force of the electromagnet 18 is weakened. Therefore, by simply operating the copy switch 24, it is possible to print on a single sheet of recording paper 2 with low noise or to copy on a plurality of sheets of recording paper 2.

Effects of the Invention Since the present invention is configured as described above, the driving force that changes the driving force of the driving unit in an ink dot printer in which a needle holding ink at its tip performs printing by bringing its tip into contact with a recording paper is provided. By increasing the driving force of the drive unit using the switching mechanism, the function of an impact-type dot printer in which the needle impacts the recording paper is provided, and it has effects such as being able to make copies as needed.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing a first embodiment of the invention, FIG. 2 is a side view with a part of the print head cut away, FIG. 3 is a plan view showing an enlarged ink supply section, and FIG. Fig. 4 is a circuit diagram of a driving force switching mechanism, Fig. 5 is a circuit diagram of a driving force switching mechanism showing a second embodiment of the present invention, and Fig. 6 is a circuit diagram of a driving force switching mechanism showing a third embodiment of the invention. FIG. 3 is a circuit diagram of the mechanism. 2...Recording paper, 8...Needle, 9...Drive unit, 11...Magnetic ink (ink), 23...Driving force switching mechanism, 27...Driving force switching mechanism, 29...
...Driving force switching mechanism.

Claims (1)

[Claims] 1. Provide a plurality of needles with their tip portions located within a magnetic field slit that holds magnetic ink, and provide a drive unit that selectively drives these needles,
In an ink dot printer of an ink dot type in which a selected needle is brought into contact with or close to a recording paper so that the magnetic ink attached to the tip thereof is attached to the recording paper, the driving force of the drive section is increased to cause the needle to move. An ink dot printer characterized by being provided with a driving force switching mechanism that causes the ink dot to collide with the recording paper.