JP2956214B2 - Driving method of piezoelectric element type print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a piezoelectric element type print head.

[0002]

2. Description of the Related Art As shown in a side view of FIG. 7, a piezoelectric element type print head 1 comprises an actuator 2 comprising a piezoelectric element, an armature 3 having a contact portion 3a which comes into contact with a stretchable surface of the actuator 2, and an armature 3. It comprises a support column 5 supported via a spring portion 4 and a printing wire 7 supported via a beam 6 provided at the tip of the armature 3.

The actuator 2 is formed by stacking a plurality of small pieces of a piezoelectric element 2a and forming a columnar shape. An internal electrode is provided at the boundary between the piezoelectric elements 2a and provided outside along the actuator 2. Every other one is alternately connected to two external electrodes.

[0004] By applying a charge based on a print signal to the external electrode of the actuator 2 having such a configuration, electrostriction is generated in each of the piezoelectric elements 2a, and the columnar actuator 2 itself expands and contracts.

[0005] The amount of expansion and contraction is very small, and the print head enlarges this minute movement by an enlargement mechanism comprising an armature 3, a spring 4, a support 5, a beam 6, etc. using the principle of leverage. Then, the printing wire 7 is driven to perform printing.

[0006] Figure 8 so that a waveform diagram of a print signal to be applied to the actuator 2 to time T ₁ applies a predetermined voltage V ₃ to the rectangular wave.

[0007]

As described above, as described above,
Printing is performed by applying a charge based on the print signal to the actuator, but the amount of expansion and contraction of the actuator is very small.
In particular, since there is no resonance at the beginning of printing, the printing density is reduced. Further, even in continuous printing, the same problem occurs if the resonance state is interrupted due to discontinuous signals. This means that since there is no resonance state, the printing energy is small, the pressing force of the printing wire is low, and the density is lower than that in continuous printing.

[0008]

According to the present invention, FIG.
As shown in the signal waveform diagram, when printing is to focus on those now being divided print signal by the timing signal M and the next two, when the now following there without is the printing of now obtained by such addition of pre <br/> Bei vibration f is not printed with amplitude smaller than the print oscillation F of amplitude required, also as shown in the signal waveform diagram of FIG. 2, during printing, the timing signal M
Synchronously, printing is performed with an amplitude smaller than that required for printing.
Not always apply a preliminary vibration f
A printing vibration F having an amplitude required for printing is applied .

[0009]

[Function] Preliminary vibration is always applied before vibration for printing.
Since the actuator of the piezoelectric element is in a resonance state, the energy of the printing wire is increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, as shown in the signal waveform diagram of FIG. 1, when printing, the current and next two print signals are focused on by dividing them by a timing signal M , and the next one is not present. If there is , a preliminary vibration f that does not print with an amplitude smaller than the printing vibration F of the amplitude required for printing at this time is added, and as shown in the signal waveform diagram of FIG. , In synchronization with the timing signal M, always apply a preliminary vibration f that does not print with an amplitude smaller than the amplitude required for printing.
While, in which so as to apply a print oscillation F of the amplitude required for based-out printing on the printing signal.

[0011] At this time, the driving voltage V ₂ of the print oscillation F is greater than the drive voltage V ₁ of the preliminary vibration f. That is, a printer for driving the piezoelectric element type print head 1 as in the present invention is shown in FIG.
As shown in the block diagram of FIG. 1, a control unit 8 and a drive unit 9 are provided. The control unit 8 receives a print signal S and a timing signal M generated by the movement of the print head 1 from an encoder 10.

As shown in FIG. 4, the control unit 8 includes a microprocessor unit (MPU) 11, a work RAM 12, a program ROM 13, and an I / O port 14, each of which has a DATA-BUS 15 and an ADDRESS-BUS 16 respectively. Is connected by

The print signal S and the timing signal M are I / O
When input to Port 14, one line of print data is recorded in Work RAM 12. The timing and magnitude of the voltage applied to the print head 1 are recorded in the program ROM 13, and the MPU 11 converts the print data recorded in the Work RAM 12 based on the data recorded in the program ROM 13 and the timing signal M. The print vibration signal F and the preliminary vibration signal f are output to the drive unit 9 in FIG.

The drive unit 9 arranges the print vibration signal F and the preliminary vibration signal f in line with the instructions of the control unit 8 and applies them to the piezoelectric element type print head 1 to drive them. In the control method by the control unit 8, in the case of FIG. 1, first, the timing signal is input from the encoder 10 by moving the piezoelectric element type print head 1 as shown in the flowchart of FIG. 5.

Next, the presence or absence of the timing signal is identified, and if the identification is not possible, the printing operation is terminated. That is, when the timing signal is a reference for the printing operation and is identified, the printing data is input to the work RAM 12, and attention is paid to the current and next printing data.

For example, when a print signal such as F in FIG. 1 is input, it is understood that there is no print signal at the present time and there is a print signal at the next time. In such a case, a preliminary vibration as shown in FIG.

After the next print vibration, if there is no print signal at the next time and a print signal at the next time, a preliminary vibration is added at the missing time. If there is no print signal at the next time point or the next time point, that is, if there is no continuous print signal of two or more, no processing is performed, and no additional preliminary vibration is performed.

When the printing signal is continuous in continuous printing or the like, printing vibration is continuously performed. By doing so, preliminary vibration is always applied before printing vibration, and the piezoelectric element type print head 1 performs printing operation in a resonance state.

On the other hand, in the control method shown in FIG. 2, as shown in the flowchart of FIG.
Enter

Next, the presence or absence of the timing signal M is identified, and if the identification is not possible, the printing operation is terminated. When the timing signal is identified, the print data is input to the work RAM 12.

The control section 8 always generates a preliminary vibration f in accordance with the timing signal M regardless of the presence or absence of print data. And if the print data is present, further printing vibrations F
Is output .

In this method, since the preliminary vibration f occurs at the start of printing and the piezoelectric element type print head 1 is in a resonance state, a stronger printing operation is performed. In FIGS. 1 and 2, the direction in which the preliminary vibration f starts to be applied is the same as the printing vibration F, but may be the opposite direction.

[0023]

According to the present invention, the printing of the piezoelectric element type print head is always performed in the resonance state, the printing vibration is performed with high energy, and the printing of high density is performed. It has great economic and industrial effects.

[Brief description of the drawings]

FIG. 1 is a waveform chart showing a driving method of a piezoelectric element type print head of the present invention.

FIG. 2 is a waveform chart showing another driving method of the piezoelectric element type print head of the present invention.

FIG. 3 is a configuration block diagram of a printer;

FIG. 4 is a configuration block diagram of a control unit;

FIG. 5 is a flowchart of the control method of FIG. 1,

FIG. 6 is a flowchart of the control method of FIG. 2;

FIG. 7 is a side view of a piezoelectric element type print head,

FIG. 8 is a waveform diagram of a conventional print signal,

[Explanation of symbols]

 1 is a piezoelectric element type print head, 8 is a control unit, 9 is a drive unit, 10 is an encoder, 11 is an MPU, 12 is a RAM for Work, 13 is a ROM for program, 14 is an I / O Port, and 15 is a DATA-BUS. , 16 is ADDRESS-BUS,

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/30 B41J 2/295

Claims (3)

(57) [Claims] At the time of printing, attention is paid to the next two print signals, which are divided by a timing signal M, and if there is no present and there is a next, a print vibration having an amplitude required for printing at the present time is provided . A method for driving a piezoelectric element type print head, wherein a preliminary vibration f which does not print with an amplitude smaller than F is added. 2. A printing method which synchronizes with a timing signal M.
Te, with always imparting pre <br/> Bei vibration f is not printed with amplitude smaller than the amplitude required for printing,-out based on the print signal print
The piezoelectric device driving method type print head is characterized in that so as to apply a print vibrations F having an amplitude required for. 3. A direction begins being preliminary vibration f is claims, characterized in that a printing vibrating F in the same or opposite directions
3. The method for driving a piezoelectric element type print head according to claim 1 or 2 .