JPS6342871A - Liquid jet recording method and liquid jet recording device - Google Patents

Abstract

PURPOSE:To easily achieve representation of gradations, by providing a first heating step of simply applying thermal energy to a liquid and a second heating step of applying to the liquid thermal energy for forming a bubble. CONSTITUTION:Gradation data are set by a reverse current preventive diode 11, and a decremental counter 1 is set. Thereafter, a High signal is outputted from a comparator 3, and one pulse is generated by a one-shot phase generator 2 at the moment the counter 1 reaches zero. Then, a voltage value is determined through amplifiers 4, 5 connected in series with the counter and the pulse generator 2, and a desired waveform is synthetically formed at a terminal 01. A pulse width t1 is determined according to a set value of the gradation data, and the amount of a liquid droplet ejected is increased or decreased through the heat generation by a heat generating element according as the pulse width t1 is larger or smaller. The voltage of a signal corresponding to t2 exceeds an ejection threshold voltage, thereby forming an ejection timing for the liquid droplet. The liquid droplets thus formed are absorbed by a paper, thereby forming dots having different diameters. These operations are continuously performed, whereby printing with different dot diameters can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a liquid jet recording method, and more particularly to a liquid jet recording method suitable for performing gradation recording.

(Prior art) The liquid jet recording method is a non-impact recording method, so it is excellent in quietness during recording, and has attracted much attention because it is capable of high-speed recording and can produce color images with high saturation. are collecting.

In recent years, there has been an increasing demand for recording not only line drawings but also images with gradation, and liquid jet recording methods that can meet this demand are attracting even more attention.

Further, among liquid jet recording methods, a recording head using a recording method using thermal energy can achieve compactness, multi-orifice design, high-density orifice design, and the like. However, in the recording method using thermal energy, there have been cases in which it has not been possible to perform gradation recording with a sufficiently wide range.

(Structure) The liquid jet recording method of the present invention applies thermal energy to at least a portion of the liquid to cause a state change in the liquid that accompanies foaming, and directs the liquid into an orifice in response to a pressure change based on the state change. In a liquid jet recording method in which recording is performed by discharging the liquid, a first heating step of applying thermal energy that does not cause bubbling to the liquid, and a thermal energy to cause the bubbling subsequent to the first heating step are provided. A second heating step of applying the liquid to the liquid is provided, and recording is performed by changing the amount of the liquid ejected by controlling the first heating step.

[Effect]

According to the recording method of the present invention, based on the principle of heating the minute heating element to generate bubbles and ejecting a small liquid, it is possible not only to easily change the diameter of the ejected droplet and record,
Since the head can be constructed using the same structure, it has become possible to easily realize gradation expression.

(Example) Recording by ejecting small droplets due to bubble generation in the liquid jet recording method of the present invention, that is, the ejection principle of the bubble jet recording method is as shown in Section 2: a, heating - b9 foaming - C9 A small droplet is ejected through the five stages of growth -d, contraction -e, and extinction, and then returns to the bright state f.The present invention is capable of controlling the size of bubbles in this foaming-growth stage. , change the diameter below the discharge.

The applied pulse shown in FIG. 3 is applied to each dot, and the diameter of the ejected droplet is changed as shown in FIG.

tl in FIG. 3 promotes foaming in the overheating limit region in the foaming-growth stage of FIG. 2.

The amount of foaming is controlled by changing the tl time. That is, the longer tl is, the more the heating element is heated, the more bubbles are formed, the bubble volume increases, and the amount of ejected droplets increases.

Also, the shorter the tl, the less foaming and the smaller the bubble volume.
The amount of ejected droplets decreases. t2 exceeds the ejection fresh-hold voltage and essentially creates the ejection timing of small droplets.

The ejected small droplets are absorbed onto the paper surface, forming dots with different diameters as shown in FIG. 5, and it is possible to realize gradation expression.

The waveform (FIG. 3) composed of tl, which controls the foaming and growth time, and t2, which creates the discharge timing, can be implemented by the following drive method.

FIG. 1 shows a preferred embodiment for carrying out the invention. 1 is a down counter, 12 is a one-shot pulse generator, 3 is a comparator, 4.5 is an amplifier, 6.7 is a transistor, 8.9 is a Zener diode, and 10.11 is a backflow prevention diode.

Gradation data is set from II, and a down counter of 1 is set. Thereafter, the count is down-counted, and the comparator No. 3 outputs a high signal until it reaches 0. At the timing when the down counter reaches 0, the one-shot pulse generator No. 2 generates one pulse.

Since they are continuous, the voltage value is determined through a 4.5 amplifier, and the desired waveform is synthesized from the 01 terminal.

The pulse width of tl is determined by the set value of the gradation data given from step 1, and the ejection timing is also created.

By performing this operation continuously, printing with different dot diameters can be obtained as shown in FIG.

FIG. 7 is another embodiment for carrying out the present invention.

12 is a latch circuit, and 13 is a counter.

14 is a table memory (ROM), 15 is a D/A converter, and 16 is an amplifier.

Gradation data is input from I2, and at the same time, a trigger is given from I3. The counter 13 will count up until a trigger is given from the next step 3, and when the trigger is given, it will be reset again and the count will go up.
start. Create lower addresses for 14 table memories. However, the time at which the next trigger is applied must be manually applied before the counter completes its count.

Also, the ``situation data'' given by Engineering 2 creates the upper addresses of 14 table memories.

Digitalized waveform data is written into the table memory No. 14 based on the upper address of the gradation data given from I2, and t changes according to the change in I2.
The length of l is variable.

The digital data output from 14 memories is 15
The signal is converted into an analog waveform by the D/A converter, passes through 16 amplifiers, and is output from 2.

The address produced by the 13 counters is the 3rd
I2, which determines the resolution of the waveform shown in the figure and is input to the 12 latch circuits, becomes an address for selecting the waveform pattern and determines the gradation.

Also, since this embodiment uses a memory table,
It is possible to create all kinds of waveforms other than the waveform shown in FIG. 3, and it is possible to create gradations based on subtle differences.

〔effect〕

As explained above, by changing the heating time of the heating element in the input signal, it becomes possible to perform recording while changing the diameter of the ejected droplets, and it becomes possible to perform gradation expression.

Furthermore, as shown in Example 2, by converting the waveform into a memory table, it is possible to create any waveform, making it possible to express changes due to subtle differences, such as gamma characteristics in gradation expression. .

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining a preferred embodiment of the present invention, Fig. 2 is a diagram for explaining the principle of a bubble jet used in the liquid jet recording method of the present invention, and Fig. 3 is a diagram for explaining gradation expression. Figure 4 is a diagram to explain the change in ejected droplets due to the input of the waveform, Figure 5 is a diagram to explain the change in printing, and Figure 6 is a diagram to explain the change in printing. A diagram for explaining the relationship between the printing of the waveform. FIG. 7 is a diagram for explaining another embodiment of the present invention.

Claims (1)

[Claims] A liquid jet recording method in which thermal energy is applied to at least a portion of the liquid to cause a state change in the liquid accompanied by foaming, and the liquid is ejected from an orifice in response to a pressure change based on the state change to perform recording. A first step that applies thermal energy that does not cause foaming to the liquid.
and a second heating step of applying thermal energy to the liquid to cause the foaming after the first heating step, and the liquid is discharged by controlling the first heating step. A liquid jet recording method characterized in that recording is performed by changing the amount of the liquid.