JPS584678Y2 - inkjet printer - Google Patents

Description

[Detailed description of the invention] This invention is based on the ink filling 9 of the ink head that ejects ink droplets.
The present invention relates to an inkjet printer that issues an alarm.

FIG. 1 is a cross-sectional view showing an ink head of a Hahals pressurized inkjet printer, in which 1 is a bimorph formed by overlapping a piezoelectric element 2 and a metal plate 3;
When an alternating electric field is applied to the material, it repeats the bending motion in the thickness direction.

4 is an annular spacer to which the bimorph 1 is fixed to one end; 5 is a front plate connected to the other end of the spacer 4; an orifice 6 is bored in the center of the front plate 5;

Reference numeral I denotes an ink chamber which is quadruple-layered by the front plate 5, the annular spacer 4, and the bimorph 1; .

The ink 9 is pressurized by the bending motion of the bimorph 1 due to the application of pulses, and is ejected as ink droplets from the orifice 6 of the front plate 5. A collection of these ink droplets is used to print characters and symbols on recording paper placed oppositely. etc. and drawing of figures etc. is performed.

On the other hand, the orifice 6 of the ink head often becomes clogged due to chemical reactions with dust contained in the ink and gases in the air, drying, etc., and there is a risk that normal printing may not be performed. was.

The present invention has been devised in view of this point, and will be described in detail below with reference to FIG. 2 and subsequent figures.

FIG. 2 shows an ink head of the present invention, similar to FIG. 1, 1 is a bimorph consisting of a piezoelectric element 2 and a metal plate 3, 4 is an annular spacer, 5 is a front plate, 6 is an orifice, I is an ink chamber, 8
9 is an ink inflow path, and 9 is ink.The difference is that a temperature sensor 10 consisting of a thermistor, thermocouple, etc. is provided to detect the temperature of the ink 9 in the ink chamber 7.

The relationship between the temperature sensor 10 and the clogging of the ink head will be described in detail with reference to the temperature characteristic diagram of the ink 9 in the ink chamber 1 shown in FIG. 3.

The temperature characteristics of the ink 9 of the normally operating ink head that performs clogging are linear at a constant temperature 1 due to the heat generation of the bimorph 1 which vibrates in a curved manner due to the pulsed alternating electric field as shown by the broken line. After that, the temperature rise stops and reaches the saturation state.

The reason for this is that the temperature of the ink 9, which rose with the heat generated by the bimorph 1, is due to l) the water cooling effect in which heat is removed by the ejected ink droplets, the air cooling effect in which the annular spacer 4 and the front plate 5 act as heat sinks, etc. This is because heat is radiated.

The present invention utilizes this temperature characteristic to detect ink clogging and issue an alarm.

That is, when the orifice 6 of the ink head becomes clogged,
Since ink droplets are not ejected from the orifice 6 and the water cooling effect cannot be expected among the heat dissipation effects mentioned above, the ink droplets exhibit a saturated state at a constant temperature.As shown by the solid line in FIG. continue.

This temperature rise is detected by a temperature sensor 10 provided on the front south plate 5, and FIG. 4 shows a block diagram of the inkjet printer of the present invention.

In the same figure, 11 is the ink head shown in detail in FIG. An ink tank 14 supplies ink 9 to the ink tank; 14 is a determination circuit that determines whether or not the ink is clogged based on the detection output of the temperature sensor 10; An alarm device is used to notify this fact, and the alarm operation of the alarm device 15 may be light, sound, or the like.

For example, the sound may be a buzzer sound, and if the sound pressure of the buzzer sound increases as the temperature rises, the sound pressure will increase if no repairs are performed by the user after a certain period of time has passed. It is also possible to raise the alarm level, resulting in even more alarming action.

Thus, the bimorph 1 responds to the signal from the pulse signal source 12.
Ink droplets are ejected from the curved vibration orifice 6 onto the recording paper 16 arranged opposite to each other.

As a result of this ejection, the temperature of the ink 9 in the ink chamber 1 increases until it reaches a certain temperature, and then the water cooling/air cooling effects come into play and the ink reaches a saturated state.

Therefore, since the detection output of the temperature sensor 10 also becomes a steady state after a certain period of time has elapsed, the determination circuit 14 determines that the ink head 11 is operating normally and does not issue an output to the alarm device 15.

On the other hand, if the orifice 6 is blocked by dust or the like contained in the ink 9, the temperature of the ink 9 in the ink chamber 7 will rise for the reason described above.

This temperature rise is detected by the temperature sensor 10 and input to the discrimination circuit 14, and the '141g1J circuit 14 outputs a signal to the alarm device 15 informing it of clogging.

In response to this signal, the alarm device 15 operates an alarm to notify the user that the ink head 11 is clogged, for example by making a buzzer sound.

As is clear from the above description, the inkjet printer of the present invention detects clogging of the ink head using a temperature sensor and issues an alarm using an alarm device, so it is possible to monitor whether the ink head is operating normally. There will be no need.

In addition, even if there is clogging, the user can immediately know about it, and the repair can be carried out quickly.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional ink head, Fig. 2 is a sectional view showing an ink head of the present invention, Fig. 3 is a characteristic diagram for explaining the principle of the present invention, and Fig. 4 is a sectional view of the ink head of the present invention. In this block diagram, 1 is a bimorph, 6 is an orifice, 1 is an ink chamber, 10 is a temperature sensor, 11 is an ink head,
Reference numeral 14 indicates a discrimination circuit, and reference numeral 15 indicates an alarm device.

Claims (1)

[Scope of utility model registration request] In an inkjet printer that prints characters, symbols, etc. by ejecting ink droplets from an ink head placed opposite recording paper, a temperature sensor is placed on the side wall of the ink head, and an alarm device is connected to the temperature sensor. An inkjet printer in which the temperature sensor detects a temperature rise due to ink clogging and activates an alarm device.