JPH0764068B2 - Liquid jet recording method and liquid jet recording apparatus - Google Patents

Description

The present invention relates to a liquid jet recording method, and more particularly to a liquid jet recording method suitable for performing gradation recording.

[Conventional technology]

Since the liquid jet recording method is a non-impact recording method, it is excellent in quietness during recording, high-speed recording is possible, and a color image with high saturation can be obtained, and thus it has attracted much attention.

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

Further, among the liquid jet recording methods, the recording head using the recording method using thermal energy can achieve compactness, multi-orifice, high-density orifice, and the like. However, in the recording method using the heat energy, it may not be said that the gradation recording having a sufficiently wide width has been sufficiently achieved.

〔Constitution〕

In the liquid jet recording method of the present invention, a thermal energy is applied to at least a part of the liquid to cause a state change accompanied by foaming in the liquid, and the liquid is discharged from an orifice according to a pressure change based on the state change. In a liquid jet recording method for performing recording by performing a recording, a first heating step of applying thermal energy that does not cause the bubbling to the liquid, and a thermal energy for causing the bubbling subsequent to the first heating step to the liquid. And a second heating step of applying, and recording is performed by changing the amount of the liquid discharged by controlling the first heating step.

[Action]

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, not only can the diameter of the ejected droplet be easily changed to perform recording, but also
Since the head can be configured with the same structure, gradation expression can be easily realized.

〔Example〕

In the liquid jet recording method of the present invention, recording is performed by ejecting small droplets due to generation of bubbles, that is, the ejection principle of the bubble jet recording method is as shown in FIG. 2, a, heating → b, foaming → c, growth → d. Then, the small droplets are ejected through the five stages of contraction → e, and disappearance, and the state returns to f, which is the initial state. According to the present invention, the diameter of the ejected droplet is changed by controlling the size of the bubble in this foaming → growth stage.

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.

T1 in Fig. 3 is t1 in Fig. 2 foaming → growth stage,
Promotes foaming in the heating limit area.

The amount of foaming is controlled by changing the time of t1.
That is, the longer t1 is, the more the heating element is heated, the more the foaming region is increased, the larger the bubble volume is, and the more the discharged droplet amount is increased. Further, the shorter t1 is, the smaller the foaming region is, the smaller the bubble volume is, and the smaller the ejected droplet amount is. t2 exceeds the ejection threshold voltage and substantially creates the ejection timing of small droplets.

The ejected small droplets are absorbed on the paper surface, and as shown in FIG. 5, dots having different diameters are formed, and gradation expression can be realized.

T1 that controls foaming and growth time and t2 that creates discharge timing
The waveform (FIG. 3) having the above configuration can be implemented by the following driving method.

FIG. 1 is a preferred-embodiment for carrying out the present invention. 1 is a down counter, 2 is a one-shot pulse generator, 3 is a comparator, 4,5 are amplifiers, 6 and 7 are transistors,
8 and 9 are zener diodes, and 10 and 11 are backflow prevention diodes.

The gradation data is set from I1, and the down counter of 1 is set. After that, it is down-counted, and High is output from the comparator 3 until it becomes 0. When the down counter reaches 0, the one-shot pulse generator 2 generates one pulse.

Since each is continuous, the voltage value is determined through the amplifiers 4 and 5, and the waveform desired to be obtained from the O1 terminal is synthesized and formed.

The pulse width of t1 is determined by the set value of the gradation data given by I1, 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 shows another embodiment for carrying out the present invention.

12 is a latch circuit, 13 is a counter, 14 is a table memory (R
OM), 15 is a D / A converter, and 16 is an amplifier.

Grayscale data is input from I2, and at the same time, a trigger is applied from I3. The counter of 13 counts up until a trigger is given from the next I3, and when the trigger is given, it is reset and starts counting up. Then create the lower address of 14 table memories. However, the time for the next trigger to be applied must be entered before the counter fully counts.

Also, the gradation data given by I2 creates the upper address of 14 table memories.

Waveform data converted into digital data is written in the table memory 14 based on the upper address by the gradation data given by I2, and the length of t1 is made variable by the change of I2.

The digital data output from the 14 memories is 15 D /
Converted to analog waveform from A converter, and output from 16 amplifiers to 2
Will be output.

The address created by the counter of 13 determines the resolution of the waveform shown in FIG. 3, and I2 input to the latch circuit of 12 becomes the address for selecting the waveform pattern and determines the gradation.

In addition, since this embodiment uses a memory table,
Any waveform other than the waveform shown in FIG. 3 can be created, and gradation characteristics due to subtle differences can be realized.

〔effect〕

As described above, by supplying thermal energy that does not cause foaming to the ink, the foaming area of the ink can be increased to increase the ejection amount, and further, the heating time to the heating element can be changed according to the input signal. As a result, it is possible to perform recording with the diameter of the ejected droplets changed, and it is possible to perform gradation expression.

Further, as shown in the second embodiment, by forming the waveform in the memory table, it is possible to create any waveform, and it is possible to represent a change due to a slight difference, for example, a gamma characteristic in gradation expression. .

[Brief description of drawings]

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 gradation expression. FIG. 4 is a diagram for explaining the waveform, FIG. 4 is a diagram for explaining the change of the ejected droplets due to the input of the waveform, FIG. 5 is a diagram for explaining the change of printing, and FIG. FIG. 7 is a diagram for explaining the relationship of waveform printing, and FIG. 7 is a diagram for explaining another embodiment of the present invention.

Claims (4)

[Claims] 1. A liquid jet recording in which recording is performed by applying thermal energy to a liquid to cause a state change accompanied by bubbling in the liquid and ejecting the liquid from an orifice according to a pressure change based on the state change. In the method, the liquid is heated with heat energy capable of changing the application time within a range where foaming does not occur in the liquid, and the foaming zone of the liquid is defined.
Heating step and a second heating step of heating the liquid with thermal energy for causing foaming in the liquid and discharging the liquid by foaming in a foaming amount according to the foaming region defined by the first heating step. A liquid jet recording method characterized in that recording is performed by means of. 2. The recording is performed by changing the amount of the liquid discharged in the second heating step by changing the application time of the first heating step. 2. The liquid jet recording method according to item 1. 3. A heating means for heating a liquid with heat energy according to an electric signal is provided, the heating means causes a state change accompanied by foaming in the liquid, and the liquid according to a pressure change based on the state change. In a liquid ejecting recording apparatus that ejects and prints, a counter that counts a period according to predetermined data, and a counter that counts a period according to the predetermined data while the counter does not generate bubbles First driving means for heating the liquid with heat energy to drive the heating means so as to define a foaming zone of the liquid; and heating the liquid with heat energy for causing foaming of the liquid after the count of the counter is completed. And second driving means for driving the heating means so as to cause the liquid to be discharged by foaming the foaming amount according to the foaming area defined by the first driving means. Liquid jet recording apparatus characterized by. 4. A control unit for performing recording by changing the predetermined data so as to change the bubbling area of the liquid by the first driving unit and by changing the amount of the liquid discharged by the second driving unit. The liquid jet recording apparatus according to claim 3, further comprising: