JPS5872460A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To conduct recording having high resolution without lowering the grade of printing by forming one part of a platen by a heat-generating resistor. CONSTITUTION:A recording medium 11 is heated through the platen 13, the surface thereof has the heat-generating resistor 12, the temperature is detected by means of a detector 14, and controlled by means of a temperature control circuit 15 through a feedback system, and the temperature of the medium 11 is kept at a fixed temperature. The drying of the ink of a printing surface printed onto the surface of the medium 11 is promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus in which a part of a platen is provided with a heating resistor in order to improve the fixing properties of ink particles adhering to a recording medium.

In an inkjet recording device, a platen and a print head are opposed to each other with a recording medium in between, and ink is supplied to the print head, and ink particles are ejected from the nozzle tip toward the recording medium, and the print head is moved parallel to the platen. to print. FIG. 1 is a perspective view schematically showing a conventional DOD type fin jet recording apparatus. Tin rockets 2 are fixed to both sides of the platen 1, and are rotated in the direction of arrow C by rotation of the drive shaft 3. career 4
is guided by a guide shaft 5 and a feed screw 6, and the feed screw 6 is rotated by a drive motor (not shown).

Due to this rotation, the carrier 4 is attached to the platen 1 by the arrow A.
and is moved in the A' direction. The inkjet print head 7 is mounted on the carrier 4. This print head 7 is provided with a plurality of nozzles and a piezoelectric element for ejecting the ink supplied by each nozzle tube 8 in the form of particles, and the piezoelectric element is selectively driven in synchronization with the movement of the carrier 4. be done. In this way, one line of printing can be performed with one movement of the carrier 4.

Note that 9 is a paper feed shaft, 10 is a paper feed roller, and 11 is a recording medium.

As shown in FIG. 2, in the inkjet recording apparatus, most of the ink particles attached to the recording medium 11
A recording medium 11 with good ink absorbency was used so that the ink was absorbed and fixed therein. In general, in a recording medium with good ink absorbency, the ink tends to bleed on the surface, and the spread of dots tends to become large. Therefore, it has been difficult to obtain high-resolution records of kanji, figures, etc.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording device that is capable of recording with high resolution and has high reliability by providing a heating resistor in a part of the platen of the inkjet recording device.

The present invention will be described below in which the above object is achieved by forming a part of the platen with a heating resistor.

Generally, in an inkjet recording apparatus, ink attached to a recording medium is fixed by ink permeation into the recording medium and evaporation of an ink solvent into the air. In other words,
The fixing time of the ink depends on the rate of ink penetration into the recording medium and the rate of evaporation of the ink. Therefore, in a recording medium in which the ink permeates quickly, the resolution of recording decreases. On the other hand, in a recording medium capable of high-resolution recording, the ink penetration rate is slow, and ink fixation proceeds mainly by evaporation of the ink solvent. Therefore, when a recording medium capable of high-resolution recording is used in a conventional inkjet recording apparatus, it takes a reasonably long time for the ink to fix.

Therefore, in the present invention, as shown in FIG. 3, a part of the platen of the conventional ink jet recording apparatus is constructed with a heating resistor, thereby enabling high resolution recording.

FIG. 3 is a perspective view showing an example of a platen 13 having a heating resistor 12 according to the present invention on its surface.

In the figure, the platen 13 has a heating resistor 12 provided on the surface of the hollow body. Since inkjet recording is non-impact, the platen does not have to be made of rubber as in the past, but may be of any material that can transport the recording medium.

Note that the heating resistor 12 may be a nichrome wire heater, a ceramic heater, a POSISTOR, or the like.

In this embodiment, the platen 13 has a size of 16011iI x 200IjI, 12W (resistance 3000.60V, 0.2A) (7) heating resistor heater L sheet is wound around it, and the recording medium 11 is directly heated.

The platen 13 can constantly heat the recording medium 11, which moves in close contact with the platen 13 during printing. By heating the recording medium 11, drying of the ink on the print surface printed by the print head 7 is promoted, and the ink fixing time can be shortened. Further, for safety reasons, it is preferable that the heating resistor 12 has a function such that it starts operating after the recording medium 11 is set in the recording apparatus.

Furthermore, as shown in FIG. 4, a temperature control system for the heating resistor of the present invention is provided, the temperature of the recording medium 11 is detected by a detector 14, and the heating resistor 12 is controlled by a temperature control circuit 15 through a feedback system. Control 1: The temperature is maintained at a predetermined temperature.

If a self-controlling element such as a POSISTOR is used as the heating resistor 12 described above, the temperature control system shown in FIG. 4 becomes unnecessary.

The relationship between the ink fixation time was investigated by changing the temperature of the recording medium using a platen equipped with the heating resistor of the present invention on its surface. Figure 5 shows the vertical relationship between the fixation time of one dot of ink attached to the recording medium. The temperature of the recording medium was plotted on the axis and the temperature of the recording medium was plotted on the horizontal axis, and experiments were conducted on three types of recording media.

The ink fixing time could be shortened by increasing the recording medium temperature. The ink fixation time for the recording medium (1) at room temperature was approximately 20 minutes on average for alphanumeric characters and approximately 50 minutes on average for peta black. The ink fixing time for recording medium (1) was approximately 40 seconds on average for alphanumeric characters and approximately 60 seconds on average for solid black.

Compared to the recording medium I, the recording medium (2) absorbs ink more easily into the recording medium, and the spread of dots on the surface is larger and the bleeding is larger.

When printing on medium I, the ink is completely circular in the shade, and the dot spread is about 1/2 that of recording medium ■. ℃, the ink fixation time became less than 10 seconds per dot.However, the dots on recording medium ■ spread out more than those on recording medium I, but the ink fixation time was shorter than that on recording medium I. For recording medium (2), a temperature of 60° C. was sufficient to keep the ink splatter time to 10 seconds or less.

As described above, the ink fixing time on the recording medium depends on the type of recording medium used, and also on the temperature of the recording medium heated by the heating resistor 12 on the next surface of the platen.
Furthermore, as shown in Figure -111,6, the dot diameter on recording medium I remained constant with # even though the silver layer of the recording medium increased. With this device, recording was performed with the recording medium temperature set at 70°C. As a result, in both cases of recording media tSi and m, the same level of printing quality was obtained as when the recording medium was placed at room temperature. The fixing time varies depending on the structure of the recording device.
Furthermore, in the case of color recording compared to monochrome recording, a shorter fixing time is required. Select recording media according to these requirements,
It is desirable to change the temperature set point of the recording medium. It would be efficient if the operator could adjust the temperature set value according to the characteristics of the recording medium.

The present invention has been explained above with reference to the embodiments. According to the present invention, a part of the platen is composed of a heating resistor, so that high-resolution recording results can be quickly fixed without deteriorating print quality. This has a significant effect in that it can perform printing with higher resolution than conventional inkjet printing apparatuses.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a conventional inkjet recording device, FIG. 2 is a perspective view illustrating the printing part of the device shown in FIG. 1, and FIG. 3 is a perspective view illustrating an embodiment of the present invention. 4 is a block diagram of the temperature control system of the platen heating resistor of the present invention, FIG. 5 is a diagram showing the relationship between the temperature of the recording medium and the ink fixing time, and FIG. 6 is a diagram showing the relationship between the temperature of the recording medium and the dot diameter. A relationship diagram is shown. In the figure, 11 is a recording medium, 12 is a heating resistor, and 13 is a recording medium.
1 is a platen, 14 is a detector, and 15 is a temperature control circuit. 7 figure T) Z figure P'353 21 40 60 20 Road record spiral

Claims (3)

[Claims] (1) In an inkjet recording device that forms characters and images on a recording medium that moves on a platen by ejecting ink particles from the nozzles of a print head having at least one or more nozzles, a portion of the platen is An inkjet recording device comprising a heating resistor. (2) A patent recording device characterized in that the heating resistor is maintained at a predetermined temperature by a temperature detector and a temperature controller. (3) The inkjet recording apparatus according to claim 1, wherein the heating resistor has a self-temperature function.