JPS5856865A - Ink jet head with temperature-controlling function - Google Patents

Abstract

PURPOSE:To enable the supply of stable ink particles onto a recording paper sheet by a simple constitution wherein an ink jet head jetting ink particles is provided with a normal temperature characteristic thermistor having a function of self-control of temperature. CONSTITUTION:At the time when a power source is made, a normal temperature characteristic thermistor 4 is at the same temperature with the room temperature, i.e. below the Curie temperature, and its resistance value is small. Accordingly, the thermistor 4 starts to generate a heat, and when the temperature rises above the Curie temperature, the resistance value increases sharply. Thereby a current value is decreased and thus the temperature of the thermistor is constantly maintained at a prescribed level. When this Curie temperature is set at a desired temperature of ink, the ink can be kept constantly at a prescribed temperature by the normal temperature characteristic thermistor 4 arranged so that it holds ink jet nozzles 3 between. The viscosity of ink is thereby kept unvaried, and thus stable ink particles can be formed constantly.

Description

[Detailed description of the invention]

The present invention relates to an inkjet head of an inkjet recording device, and relates to an inkjet head with a temperature control function that keeps the ink temperature constant. Conventionally, in an inkjet recording device, printing on recording paper is performed in the following manner. . First, ink is sent from an ink supply source to an inkjet head via a supply tube. An inkjet head has a number of individual ink passages surrounded by intensifiers. During a printing operation, these piezoelectric elements contract in response to print information from a control device, and at this time, ink ri in each ink path is atomized and jetted from an inkjet nozzle toward a recording paper. The print quality obtained with this type of inkjet recording device depends, among other things, on the viscosity of the ink. In other words, in the case of ink having a low viscosity, the formation of ink droplets is hindered, and double ink droplets are ejected from the inkjet nozzle, which can seriously damage the print surface. On the other hand, increasing the viscosity of the ink can improve ink particle formation and print quality. However, on the other hand, such an increase in viscosity causes the ink viscosity to easily fluctuate due to slight temperature fluctuations within the room temperature range. About this. Immediately, the particle size of the ink particles changes and print quality deteriorates.

[Connects 1 connection. It has the following drawbacks. Therefore, in order to always obtain good print quality on recording paper, it is necessary to keep the viscosity of the ink as constant as possible. In order to keep the viscosity of the ink constant, conventional devices employ a method of keeping the ink at a constant temperature. A method of keeping the inkjet temperature constant is to arrange a heating device around the inkjet nozzle of an inkjet head and electrically control the heating temperature using a single circuit device. Additionally, 11 applications have been filed regarding this technology. For detailed operation, please refer to, for example, the specification of Japanese Patent Laid-Open No. 53-84729. However, the circuit device disposed around the inkjet nozzle has a two-circuit configuration of a temperature detection path and a heating circuit, so the configuration is complex. I
It has drawbacks such as complicated I#. In view of the above drawbacks, an object of the present invention is to provide an inkjet having a temperature control device f having an extremely simple configuration. It's about becoming an apprentice. An object of the present invention is to provide an inkjet recording device that performs printing by jetting ink particles onto recording paper.
#The inkjet recording device is an inkjet recording device with a temperature control function, characterized in that the inkjet head for ejecting ink particles has a positive temperature characteristic thermistor f having a self-temperature control function. This is achieved by using a double nozzle. Next, one embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 1 to 3 are diagrams showing an embodiment of an inkjet head with a temperature control function according to the present invention, and explanatory details thereof. #I1 In the figure, 1 is a piezoelectric element 3Ifi that contracts in response to printing information from a control device (not shown) and sends ink to an inkjet nozzle 3 via an ink passage 2;
An inkjet nozzle ejects ink particles from a nozzle plate 5, and a positive temperature characteristic thermostat having both temperature detection and heating functions. #! 2 is a diagram illustrating a circuit configuration using a positive temperature sensor. The third factor is a diagram showing the resistance temperature characteristic of the positive temperature characteristic circuit. This figure shows the resistance temperature characteristics of the positive temperature characteristic sensor 4 when the primary temperature, that is, the temperature at which the resistance value rapidly increases is 50°C. The temperature of this key can be set in various ways from normal temperature to 320"C depending on the material of the device [41]. The positive temperature characteristic Säns #4 is made by adding a small amount of rare earth to barium chloride. As a result, the specific resistance at room temperature is 10 to 1.
It is a nil valence control type 4S sounding body that exhibits 0-Ω scratches, and is a round wire thermal resistance element with positive resistance-temperature characteristics. Next, the operation will be explained. When the power is turned on, Nurse #4 has a positive temperature characteristic. At the same temperature as room temperature, the resistance value is small because it is less than -lI. Therefore, the amount of current flowing through the positive temperature characteristic nurse star 4 is large, and therefore the positive temperature characteristic nurse star 4 starts to generate heat. When the amount of heat generated increases and the positive electric characteristic f-characteristic S-4 becomes more than ki, ream degree, the resistance value of the positive temperature characteristic nurse #4 becomes as shown in the figure 7 shown in Fig. 3. It increases rapidly. Accordingly, the amount of current flowing through the positive temperature characteristic sensor I is reduced, so that heat generation of the positive temperature characteristic sensor I is suppressed. By repeating the above-mentioned operations, the positive temperature characteristic sensor 4Fi always keeps its own temperature constant. Therefore, the temperature of the positive temperature characteristic sensor 4 is set to the desired ink temperature. If this is done, as shown in FIG. 1, it is possible to always obtain a constant ink mW by arranging the stand 4 with a positive IIT characteristic so as to sandwich the inkjet nozzle 3. Therefore, since the ink level is kept constant, the viscosity of the ink does not change and stable ink droplets can be formed at all times, and stable ink droplets are always supplied to the printing surface. Further, unlike conventional devices, a temperature control circuit is not required, and the configuration can be simplified. Next, another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a diagram showing another embodiment of the inkjet head with temperature control function according to the present invention. In the same figure, the difference from the embodiment of tRl shown in FIG. The nozzle plate of the head itself has a positive temperature characteristic function. That is, since the nozzle plate itself through which the inter-particles fly has the function of the positive temperature characteristic thermistor, in the present embodiment rcsP, the amount of heat generated from the positive temperature characteristic thermistor 4 can be applied directly to the ink. Therefore, as shown in the embodiment of the present invention, the nozzle plate 5
Compared to the case where the temperature of the ink is controlled by heat conduction of the nozzle plate 5 through the nozzle plate 5, the heat transfer efficiency is much better. Therefore, the ink temperature can be easily and reliably controlled, and more stable ink particles can be supplied to the printing surface than in the above-described embodiments. Furthermore, according to the configuration of this embodiment, the number of parts can be reduced because the nozzle plate itself has the function of a positive temperature characteristic thermistor. The manufacturing price can be reduced. It is further advantageous that the nozzle plate of this embodiment can be applied to an interjet head having a structure in which the nozzle plate is replaceable. As explained above, according to the present invention, by disposing a positive temperature characteristic thermistor in the inkjet head,
It is possible to obtain an inkjet head that does not require a temperature control circuit and can stably supply ink particles to recording paper with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of an ink jet with a temperature llllll1 function according to the present invention, and FIG. 2 is a diagram showing a circuit configuration using a positive temperature characteristic thermistor. FIG. 3 is a diagram showing the resistance temperature characteristics of a positive temperature characteristic thermistor, and FIG. 4 is a diagram showing another embodiment of the inkjet head with a temperature control function according to the present invention. In the figure, 1 is a piezoelectric element, 2 is an ink passage, 3 is an inkjet nozzle, and 4F! It is a positive temperature characteristic thermostat. Figure 2 Tayu degree (6C) Figure 3 Figure 4

Claims (1)

[Claims] Among inkjet recording apparatuses that perform printing by jetting ink particles onto recording paper, wrinkle inkjet recording apparatus r! , an inkjet head with a temperature control function, which is defined as 4H1k, in which the inkjet head that ejects the ink particles has a positive temperature characteristic thermistor having a self-temperature control function.