JPS58208062A - Ink jet type recording apparatus - Google Patents

Abstract

PURPOSE:To prevent staining caused by the flight of an ink, by a method wherein the part of the solid ink is heated and melted according to a recording signal and emitted a ink droplets to reduce the clogging of a nozzle or the change in characteristics of the ink. CONSTITUTION:A thermal head 30 having an insulating bass plate 31 mounted with a heat generating resistor 32 formed thereto is attached to one end of a cylindrical insulating transparent case 20 having a conductive solid ink 10 showing a solid phase state at a room temp. accommodated therein and heated and driven by the application of a recording signal to bring the part of the ink 10 to a molten phase state under heating due to the resistor 32 while a capacitor 110 is charged by a power source 90. In the next step, a change-over switch 100 is changed over to apply high voltage between electrodes 50, 60 through a spring 40 and the ink 10 in the liquid phase state is emitted toward recording paper 30 as ink droplets through the passing orifice of the electrode 60.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording device, and more specifically, it provides a novel device using solid ink that is in a solid state at room temperature.

Various types of inkjet recording devices have been proposed because they can perform non-contact recording, have extremely low noise, and can easily perform color recording.

However, conventional devices of this type use liquid ink that is in a liquid phase at room temperature, which tends to cause nozzle clogging, and changes in ink characteristics that affect the ink supply system and ink droplet generation. There are disadvantages such as being easy to clean, easily causing stains due to ink scattering, and requiring a considerable number of man-hours for maintenance such as replenishing ink.

The present invention is a book that solves these drawbacks, and includes solid ink that is in a solid state at room temperature, a heating means that heats and melts a part of the solid ink in accordance with a recording signal to make it into a liquid state, and and a droplet ejecting means for ejecting the ink as ink droplets in accordance with a recording signal.

Hereinafter, a detailed explanation will be given using the drawings.

FIG. 1 is a structural explanatory diagram showing an example of the present invention, in which 10 is solid ink that is in a solid state at room temperature, 20 is a case, 30 is a thermal head used as a heating means, 4
0 is a conductive spring, 50.60t/'i electrode, 7
0 is a spacer, 80.90 is a power supply, 100 is a changeover switch, 110 is a capacitor, 120 is a transformer, 130f
'i Recording paper.

The solid ink 10 is mainly composed of a pigment and a binder, and is electrically conductive. This solid ink 10 is in a solid state at room temperature, but when heated to 60 to 100° C., it melts into a liquid state and is formulated to have a viscosity comparable to that of water.

The case 20 houses the solid ink 10 and the splash 40, and is formed into a cylindrical shape from an insulating transparent member (for example, a synthetic resin material).

The thermal head 30 heats and melts a part of the solid ink 10 according to a recording signal to make it into a liquid phase, and TaN 2 is applied to the surface of an insulating substrate 31 such as a ceramic substrate.
The heating resistor 32 is attached to one end 21 of the case 20 so as to be in contact with the solid ink 10. Note that a through hole 33 is provided in the center of the thermal head 30.

The spring 40 is used to press the solid ink 10 against the thermal head 30 and to keep the potential of the solid ink 10 at the same potential as the potential of the electrode 50.

The electrode 50 applies a voltage to the solid ink 1° via the spring 40, and is detachably connected to the other end 22 of the case 20, for example, by screws.

The electrode 60 applies a voltage that creates a predetermined potential difference between the electrode 60 and the solid ink 10, and
It is attached to the front surface of the thermal head 30 in parallel with the thermal head 30 via a spacer 70 made of an insulator. This electrode 60
A through hole 61 is also provided in the center of the thermal head 30 so as to be coaxial with the through hole 33 of the thermal head 30 .

For safety reasons, it is desirable that these electrodes 50 and 60 have a voltage of Vcm so that the electrode surfaces are not exposed to the surface.

A power source 80 is used to drive the thermal head 30 according to a recording signal, and is applied to the thermal head 30 via a changeover switch 100.

,,7 The power source 90 is for charging the capacitor 110' and exciting the primary winding W of the transformer 1200, and is connected to one end of the capacitor 110 and the primary winding W of the transformer 120 at one end.

The other end is connected to the other end of the capacitor 110, and the transformer 1 is connected via the changeover switch 100.
Volume 111j of 20! W, is connected to the other end.

Selector switch 100H1 power supply 80 to thermal head 3
0 and the voltage applied from the power source 90 to the primary winding W of the transformer 120 are switched in a complementary manner according to the recording signal. That is, while the thermal head 30 is being heated and driven, no voltage is applied to the primary winding W of the transformer 120 and the capacitor 110 is charged, and while the thermal head 30 is not being driven, the transformer 120 is 1
The next winding W has the discharge current of the capacitor 110 and the power supply 9
An excitation current from 0 flows, and a high voltage (for example, 3 KV) corresponding to the turns ratio of the secondary winding W2Ktfi is induced.

The transformer 120 applies a high voltage according to the recording signal V between the electrodes 50 and 60, and the secondary winding W2 has one end connected to the electrode 50 and the other end connected to the electrode 60.

The recording paper 130 is arranged so as to face the electrode 60.

The operation of the device configured in this way will be explained.

When a recording signal is applied, first, the thermal head 30 is heated and driven. As a result, a portion of the solid ink '10 that is in contact with the thermal head 30 is heated and melted, and becomes a liquid state. During this time, the capacitor 1lOI/i power supply 90
It is fully charged. Thereafter, the changeover switch 100 is switched. As a result, a high voltage is applied between the electrodes 50 and 60, and the heated and melted ink in the liquid phase V is electrostatically attracted and ejected as ink droplets toward the recording paper 130. and adheres to the recording paper 130. By repeating such an operation in response to a recording signal, an inkjet type recording operation is performed.

FIG. 2 is a structural explanatory diagram showing the hair portion of another embodiment of the present invention, in which parts equivalent to those in FIG. 1 are given the same reference numerals. In FIG. 2, 1401't thermal head, 15
0 Uj%tE. In the thermal head 140, two heating resistor patterns 142 and 143 are formed concentrically on one surface of an insulating substrate 141 as shown in (a) K, and on the other surface as shown in H (b). As shown, an annular structure 144 corresponds to the heating resistor pattern 142.
A kerf 1 is provided and communicates with the outside as a nozzle.
45 are provided.

In such a configuration, when a recording signal is applied, first, the heating resistor 143 inside the thermal head 140 is heated and driven. As a result, a portion of the solid ink 10 that is in contact with the thermal head 140 is heated and melted, becomes a liquid phase, and flows into the annular groove 144 . Thereafter, the heating resistor 142 outside the thermal head 140 is heated and driven. As a result, bubbles are generated in the liquid phase ink that has flowed into the annular structure 144 due to thermal energy.
Ink droplets are ejected from the kerf 145 toward the recording paper 130 and adhere to the recording paper 130 . By repeating this operation according to the recording signal,
As in FIG. 1, it is emphasized that an inkjet type recording operation is performed. Although FIG. 2 describes an example in which a heating resistor is provided on one surface and a groove is provided on the other surface as a thermal head, it is also possible to provide a heating resistor and a groove on one surface. .

Further, as shown in FIG. 1, a thermal head having a through hole in the center may be used to perform the injection similar to that in FIG. 2 through the through hole in the center.

In this case, two sets of heating resistor patterns are provided concentrically around the through hole as in FIG. 2, and the outer pattern is heated to about 10oC to dissolve the solid ink.
Thereafter, the inner pattern may be heated to about 300'C to generate bubbles in the ink and then jetted. Note that these heating resistor patterns may be formed radially.

As described above, according to the first aspect of the invention, since solid ink that is in a solid state at room temperature is used, it is easier to see the nozzle than when using a conventional liquid ink that is in a liquid state at room temperature. The practical effects are extremely large: there is less risk of clogging, there is less chance of change in ink characteristics, stains due to ink scattering are less likely to occur, and ink can be easily replenished.

In the above embodiment, a known thermal head is used as a heating means for heating and melting solid ink and a droplet ejecting means for ejecting heated and melted ink as ink droplets, but the present invention is not limited to a thermal head. Alternatively, an insulating substrate provided with a heater wire may be used.

It goes without saying that color recording can also be performed by using a plurality of devices according to the present invention and associating each device with a different color.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram showing one embodiment of the present invention, and FIG. 2 is a structural explanatory diagram showing main parts of another embodiment of the present invention. 10...Solid ink, 20...Case, 30, 14
0...Thermal head, 4o...Spring, 50.60
...electrode, 70...spacer, 80.90...power supply, 100...changeover switch, 11o...capacitor, 12o...transformer, 130...recording paper, 15o
...Back cover. γ）−1゜Representative Patent Attorney Shinsuke Ozawa (−, □゛− and・′

Claims (1)

[Claims] A solid ink that is in a solid state at room temperature, a heating means that heats and melts a portion of the solid ink in accordance with a recording signal to make it into a liquid state, and droplets that eject the heated and melted ink as ink droplets in accordance with a recording signal. An inkjet recording device characterized by being composed of a discharge means and a discharge means.