JPH05318757A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To detect the residual amount of ink so as to be capable of avoiding the stopping of a printer when the residual amount of ink is reduced as much as possible. CONSTITUTION:An ink jet recording apparatus is equipped with a head part 11 injecting ink 22 to a material to be recorded and the ink supply part 26 connected to the head part 11 to supply the ink 22. An ink residual amount detection means 30 detecting the presence of the ink 22 is positioned between the head part 11 and the ink supply part 26 not only to make it possible to detect an ink near end at least in such a state the ink 22 yet remains in the head part 11 but also to take correspondence such as the supply of ink before printing becomes perfectly impossible and the stopping of a printer can be avoided as much as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having an ink remaining amount detecting function.

[0002]

2. Description of the Related Art In recent years, among various recording methods, the non-impact recording method has attracted attention for quiet environments such as offices because noise generation during recording is so small that it can be ignored.
Among them, the so-called inkjet recording method, which is capable of high-speed recording and can be recorded on so-called plain paper without requiring a special fixing process, is an extremely effective method, and various methods have been proposed or put into practical use.

In such an ink jet recording method, small droplets of a recording liquid, so-called "ink", are ejected,
Recording is performed by adhering to a recording medium, and is classified into several methods according to the method of generating recording liquid droplets and the control method for controlling the flight direction of droplets. It is common to use ink that is a liquid.

Therefore, the ink must be stored in a liquid state like gasoline in automobiles, and if scattered, it will pollute the surroundings, so that the ink leaks even if there is vibration or shock. It must be stored in the ink container to prevent this. In addition, physical properties (that is, surface tension, viscosity, etc.) must be constant, and it is also necessary to prevent evaporation of constituent components of the ink as much as possible. Further, in the case of an ink jet printer of a type that ejects ink by applying a voltage only when necessary without pressurizing the ink, the ink surface should be kept constant and at the same pressure as the atmosphere. It is also necessary to do.

In any case, when the remaining amount of ink in the ink container is low, the amount necessary for printing must be supplemented, so that the remaining amount of ink is displayed, or at least the remaining amount is printed. A warning should be issued when the number is low, and good printing should always be possible.

From such a point of view, conventionally, the one shown in FIG. 16 is used to detect the remaining amount of ink in the ink container. In the mechanism shown in FIG. 16A, a float 3 with a built-in magnet is provided in a floating manner on a side path 2 of an ink container 1, and a reed switch 4 is provided facing the side path 2. As a result, when the amount of ink 5 in the ink container 1 becomes low, the float 3 in the side passage 2 descends according to the liquid level of the ink 5 and activates the reed switch 4 to display the remaining amount of ink.

Further, as shown in FIG. 1B, instead of the reed switch 4, the light emitting element 6 and the light receiving element 7 are arranged to face each other so as to sandwich the side path 2 so that the remaining ink amount can be detected. Some have been done. That is, when the amount of the opaque ink 5 decreases to a predetermined level or less, the light receiving element 7 can receive the light from the light emitting element 6, and it is possible to detect that the amount of remaining ink is low.

Further, Japanese Patent Publication No. 63-44548 proposes a method in which a strain gauge is attached to the ink containing bag and the strain gauge detects the strain of the ink containing bag which is deformed according to the remaining amount of ink. There is.

[0009]

However, whichever method is used, the time at which the presence or absence of the ink is detected cannot be said to be proper, and the ink is exhausted when it remains in the ink container even though it is a little. If it is allowed to be used thereafter in order to avoid waste, the actual ink end point is unknown, which may cause troubles such as blank printing. That is, it can be said that it is not very useful for detecting the ink end.

In addition, the float 3 as shown in FIG.
The method described in (1) has a problem in that the detection accuracy is insufficient because the movement of the float 3 in the ink 5 is not smooth.

Further, in the method using the optical detecting means as shown in FIG. 2B, the transparency of the side passage 2 is impaired and the detection accuracy is deteriorated when it is used for a long time due to the adhesion of the ink dye. There is a problem that ends up.

Further, in the case of the strain gauge method, the deformation of the ink containing bag is not necessarily proportional to the remaining amount of ink, and therefore there is no great difference in detection accuracy from that of the above method, which is a very practical method. I can't say.

[0013]

According to another aspect of the present invention, there is provided an ink jet recording provided with a head portion for ejecting ink toward a recording medium and an ink supply portion connected to the head portion for supplying ink. In the apparatus, an ink remaining amount detecting means for detecting the presence or absence of ink is provided between the head portion and the ink supply portion.

In this case, according to the second aspect of the invention, the remaining ink amount detecting means has an electro-mechanical converter.

Further, according to the third aspect of the present invention, the ink remaining amount detecting means is configured so that the ink in the upstream side of the head portion is based on the change in mechanical impedance as seen from the electro-mechanical converter located upstream of the head portion. A detector is provided to detect the presence or absence of.

Further, in the fourth aspect of the invention, the electro-mechanical converter has a vibrating structure for applying vibration to the ink or the hollow region where the ink is absent via the metal, glass or ceramic material.

Further, according to a fifth aspect of the invention, there is provided an ink jet recording apparatus comprising a head portion for ejecting ink toward a recording medium and an ink supply portion connected to the head portion for supplying ink. The ink supply unit is formed by an ink storage unit that is in communication with the atmosphere and a connection unit for the head unit, and is disposed in the middle of the connection unit and reaches a cavity region due to ink consumption, and the ink end on the upstream side of the head unit. Ink remaining amount detecting means for detecting is provided.

[0018]

According to the first and fifth aspects of the present invention, the remaining ink amount detecting means is provided between the head portion and the ink supply portion to detect the presence or absence of ink, so that there is still ink remaining in the head portion. The ink end can be detected as a near end when the printer is in a state of being in contact, and it is possible to take measures such as ink replenishment before printing cannot be completed completely, and it is possible to avoid the printer down as much as possible.

According to the second aspect of the present invention, since the ink remaining amount detecting means is configured to have the electro-mechanical converter, the detection method does not come into direct contact with the ink, and corrosion due to the ink is not considered. Good and reliable detection.

According to the third aspect of the present invention, the electro-mechanical converter is used, and the hollow state in which there is no ink at the detection location is detected as a change in mechanical impedance seen from the electro-mechanical converter. , A highly reliable detection method that does not cause corrosion due to ink. In addition, since the detecting means does not have any dynamic element without using the optical means, highly reliable detection is possible also from this point.

According to the fourth aspect of the invention, the portion for transmitting the vibration of the electro-mechanical transducer to the ink or the cavity region is made of metal, glass or ceramic material, so that the detection by the mechanical impedance change is highly accurate. Can be done. Further, these materials also have excellent corrosion resistance as an ink supply member.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The present embodiment is applied to a bubble jet head which is one of inkjet heads,
The structure and operation principle will be described with reference to FIGS. As shown in FIG. 3, the head chip (head portion) 11 is formed by stacking a lid substrate 13 on a heating element substrate 12. Here, the lid substrate 13 is provided with an ink inlet 14 for ink to be a recording liquid as shown in FIG. 4A, and a flow channel 16 for forming an orifice 15 as shown in FIG. Are formed. The inflow port 14 communicates with a liquid chamber 17 connected to the flow path 16. In addition, as shown in FIG. 4B, each orifice 1 is formed on the heating element substrate 12.
A plurality of heating elements (heaters) 18 corresponding to No. 5 are formed, and they are individually connected to the control electrode 19 and commonly connected to the common electrode 20. These electrodes 19
One end of is bonded to the end of the heating element substrate 12 and serves as a bonding pad section 21 serving as a drive signal introducing section.

In such a head chip 11 structure, ink ejection by a bubble jet is performed by a process as shown in FIG. First, in the steady state
In the state shown in (a), ink 2
The surface tension of 2 and the external pressure are in equilibrium. Next, when the heater 18 is heated and the surface temperature of the heater 18 rapidly rises until the boiling phenomenon occurs in the adjacent ink layer, minute bubbles 23 are scattered as shown in FIG. Further, the adjacent ink layer that is rapidly heated on the entire surface of the heater 18 is instantly vaporized to form a boiling film, and the bubble 23 grows as shown in FIG. At this time, the pressure in the nozzle is
3 rises, the balance with the external pressure on the orifice surface is lost, and the ink column 24 begins to grow from the orifice 15. FIG. 6D shows a state in which the bubble 23 has grown to the maximum, and the ink 22 corresponding to the volume of the bubble 23 is extruded from the orifice surface. At this time, no current is flowing through the heater 18, and the surface temperature of the heater 18 is decreasing. The maximum value of the volume of the bubble 23 is slightly behind the timing of applying the electric pulse. Eventually, the bubbles 23 are cooled by the ink 22 and the like,
It begins to contract as shown in (e). At the front end of the ink column 24, the ink 22 moves forward while maintaining the extruding speed, and at the rear end, the ink 22 flows back from the orifice surface into the nozzle due to the decrease of the nozzle internal pressure as the bubble 23 contracts, and the ink column 24 becomes narrowed at the base. Occurs. Thereafter, as shown in FIG. 6F, the bubble 23 further contracts, the ink 22 contacts the heater 18 surface, and the heater 18 surface is further cooled. At the orifice surface, the external pressure is higher than the internal pressure of the nozzle, so a large meniscus enters the nozzle. The tip portion of the ink column 24 becomes a droplet 25 and flies toward the recording paper (not shown) at a speed of 5 to 10 m / sec. After that, as shown in FIG. 7G, the ink 2 is discharged to the orifice 15 by the capillary phenomenon.
In the process in which 2 is supplied (refilled) again and returns to the steady state in FIG.

The ink supply section 26 for supplying the ink 22 to the head chip 11 is constructed as shown in FIG. That is, the ink supply unit 26 is located at a position higher than the head chip 11 and stores an ink 22 (ink storage unit) 27, a lower portion of the ink tank 27 and the inlet port 1 of the head chip 11.
4 and an ink supply pipe (connecting portion) 28 that connects the same. An atmosphere communication hole 29 is formed in the upper portion of the ink tank 27. Then, in the middle of the ink supply pipe 28 (that is, between the head chip 11 and the ink supply unit 26, which is upstream of the head chip 11).
Is provided with an electro-mechanical converter functioning as an ink remaining amount detecting means, more specifically, a pipe-shaped electrostrictive vibrator 30 in a state of covering the outer circumference of the ink supply pipe 28.

In such a structure, FIG. 1A shows a state in which the ink 22 is sufficiently filled upstream of the head chip 11, and FIG. 1B shows the ink tank 2 as the ink is consumed.
The area occupied by air increases at 7 and the resulting cavity area 3
1 reaches the detection position by the electrostrictive vibrator 30, and the ink 2
2 shows a state in which the remaining amount is very small. In the present embodiment, when the state shown in FIG. 7A is changed to the state shown in FIG. 7B, that is, when the ink 22 is slightly and completely disappeared, Is detected by the electrostrictive vibrator 30 to notify the user.

Now, comparing the figures (a) and (b) with each other, the difference in the states is whether or not the ink 22 is filled in the ink supply pipe 28 at the electrostrictive vibrator 30. Here, the same figure
When the ink 22 is full as shown in (a),
Since the mechanical impedance seen from the electrostrictive oscillator 30 changes when the ink 22 is not filled and the cavity region 31 is formed as shown in FIG.
By detecting the voltage change or the current change applied to 0, it is possible to detect whether or not the ink 22 is filled in the ink supply pipe 28.

In this embodiment, since the presence or absence of the ink 22 is detected by the voltage change applied to the electrostrictive oscillator 30, the electrostrictive oscillator drive circuit 32 and the detection circuit 33 as shown in FIG. 6 are constructed. ing. First, an NPN type transistor 35 is provided in which the output of the NAND gate 34 to which a drive signal is input is input to the base and the emitter is grounded. The collector of the transistor 35 is connected to the base of an NPN type transistor 36, and is also connected to a positive DC power source + via a resistor 37. The collector of the transistor 36 is connected to the positive DC power source +, and the resistor 38 and the electrostrictive oscillator 30 are connected in series between the emitter and the ground. A resistor 39 is connected in parallel to the electrostrictive oscillator 30. The electrostrictive vibrator drive circuit 32 is configured by these. Further, a series circuit of a Zener diode 40 and a variable resistor 41 is connected in parallel to the electrostrictive oscillator 30, and a filter of a capacitor 42 and a resistor 43 is formed between the slider of the variable resistor 41 and the ground. Are connected in series, and the anode of the diode 44 is connected to the midpoint of the connection. The cathode of the diode 44 is grounded via the parallel circuit of the capacitor 45 and the resistor 46, and is connected to one input terminal of the voltage comparator 47. Here, the diode 44,
The capacitor 45 and the resistor 46 form a rectifying circuit. Further, a variable resistor 48 connected between the positive DC power source + and the ground is provided, and its slider is the voltage comparator 4
7 is connected to the other input terminal. The detection circuit 33 is configured by the elements connected to the subsequent stage of the electrostrictive oscillator 30.

In such a structure, when a pulse voltage having a predetermined pulse width is applied to the NAND gate 34, the transistor 35 is turned off and the DC power source supplies the resistor 37.
A high voltage is applied to the base of transistor 36 through. As a result, the transistor 36 is turned on, a high voltage is applied as a pulse voltage to the electrostrictive oscillator 30 through the transistor 36 and the resistor 38, and the electrostrictive oscillator 30 is driven.

At this time, the rise time and fall time of the pulse voltage applied to the electrostrictive oscillator 30 are substantially determined by the resistors 38 and 39 and the electrostatic capacitance of the electrostrictive oscillator 30, and the pulse waveform thereof is shown in FIG. As shown in (a).

The pulse-driven electrostrictive oscillator 30 causes a strain, and the strain causes the ink supply pipe 28 to have a curved wall. Then, when the strain of the electrostrictive oscillator 30 disappears, the tube wall of the ink supply tube 28 also returns to its original state.

Here, when air bubbles are present in the ink supply pipe 28 or the ink 22 is not filled, that is, when the cavity region 31 is generated, the electrostrictive vibrator 30, its vibrating plate and ink supply. Electrostrictive oscillator 3 of system consisting of tube 28
The motional impedance viewed from 0 changes abruptly at a certain frequency, and a peak appears on the frequency characteristic. Therefore, when the electrostrictive oscillator 30 is pulse-driven, it causes a certain frequency oscillation, and the voltage across the frequency becomes a pulse voltage in which the oscillation voltage is superimposed on the drive pulse as shown in FIG. 7B. Therefore, if this vibration voltage is detected, whether the ink 22 is filled inside the ink supply pipe 28,
Alternatively, it can be detected whether the ink 22 is exhausted and the cavity region 31 is generated.

As shown in FIG. 8A, when an oscillating voltage exists in the voltage across the electrostrictive oscillator 30, the voltage across the electrostrictive oscillator 30 is cut by the Zener diode 40 and added to the variable resistor 41. The output voltage from the slider of the variable resistor 41 has a waveform as shown in FIG. This output voltage becomes an AC waveform as shown in FIG. 7C by passing through a filter composed of the capacitor 42 and the resistor 43. Further, it is rectified by passing through a rectification circuit including a diode 44, a capacitor 45 and a resistor 46, and is rectified as shown in FIG. In the voltage comparator 47, if the comparison voltage value is preset by the variable resistor 48, the output becomes high potential when the input voltage becomes larger than this comparison voltage. Therefore, if the comparison voltage value is set so that the output of the voltage comparator 47 rises to a high potential when the ink 22 is consumed and the cavity region 31 is formed in the ink supply pipe 28, the high voltage is set. The presence or absence of the ink 22 can be detected by detecting the rise to the potential. According to such a detection method, detection accuracy is high and deterioration with time does not occur.

As a result, for example, the output of the voltage comparator 47 may drive the indicator or the alarm. That is,
It is possible to notify that the remaining amount of the ink 22 is low by notifying the fact that the ink 22 is almost exhausted by LED light emission, a warning sound, or the like. Therefore, the printer user can properly know the ink replenishment time by such a display or warning, and can prevent the driving in the ink-free state. In particular, according to the present embodiment, since the presence / absence of ink is detected not between the head chip 11 and the ink supply unit 26, that is, at a position upstream of the head chip 11, the ink 22 is detected before the ink 22 is completely consumed. It is possible to detect the ink near end that the ink 22 runs out in a little while, and it is possible to take measures such as ink replenishment before printing cannot be performed. That is, according to the method in which some kind of ink remaining amount detecting means is provided in the head portion, the ink end is detected, that is, the ink is completely exhausted and printing cannot be performed any more, and the printer must be down. On the other hand, according to the present embodiment, since the near end detection is possible, the ink 22 still exists in the liquid chamber 17 of the head chip 11 even at the stage when the ink supply pipe 28 is detected as having no ink. Printing can be continued for a while, and it is not always necessary to bring down the printer.

Further, considering the detection method itself, since the electrostrictive vibrator 30 is used and it does not come into direct contact with the ink 22, there is no fear of corrosion by the ink 22 and the reliability is maintained for a long time. High detection is possible. By the way, a thermocouple or thermistor is arranged near or on the heating element, or the heating element is energized when the ink 22 is exhausted by supplying electricity to the heating element. Since the temperature rises due to this, a method of detecting this temperature rise by a thermocouple or the like can be adopted, but in comparison with such a method, according to the present embodiment, since heating is not involved, There is no concern that the detection unit will be thermally deteriorated, and a highly reliable detection value can be obtained from this aspect as well. Further, according to the method using the electrostrictive oscillator 30, there is no moving part unlike the floating method (though microscopically, there is a movement of vibration), and it does not depend on the optical method. It is possible to perform highly reliable detection without the problem of deterioration of detection accuracy due to ink dye adhesion.

The output of the voltage comparator 47 is not limited to such display / warning, but is applied to, for example, a printer unit of a facsimile, and the output of the voltage comparator 47 stops the printer operation. May be. That is, in the case of unmanned operation at night, if there is no ink when a facsimile is sent in an unmanned state, there is a possibility that the facsimile information will be a blank copy and will not be reproduced. When the output from 47 is output, the operation of the printer unit is stopped, while the operation is switched so that all the facsimile information sent is stored in the memory, blank printing can be avoided and the facsimile information stored in the memory is If the user prints out after replenishing ink the next morning, there will be no missing information.

Now, the detection section provided with the electrostrictive vibrator 30 will be described in detail. What is important in the detector is
The purpose is to efficiently transmit the vibration of the electrostrictive vibrator 30 to the ink 22 in the ink supply pipe 28 or the air in which the cavity region 31 is formed. Further, the tube wall of the ink supply tube 28 is also curved according to the strain of the electrostrictive oscillator 30, and then it is necessary to return to the original state when the strain disappears. Therefore, the tube wall is elastically deformable. Is required. Therefore, polyethylene or the like, which is soft and can be freely deformed, is not suitable as the material of the ink supply pipe 28, and metal such as stainless steel,
It is preferable that the material has rigidity such as glass or ceramics and can be elastically deformed up to a region where a certain load is applied. Further, a material capable of efficiently transmitting the vibration generated from the electrostrictive vibrator 30, that is, a material such as metal, glass or ceramics having an acoustic impedance of at least 1.0 × 10 ⁷ N · s / m ³ is used. There is a need. By the way, when a material having an acoustic impedance of 0.3 × 10 ⁷ N · s / m ³ or less, such as rubber or a plastics material, is used, the vibration is absorbed to the contrary. Is not suitable. The most preferable material is a material having high acoustic impedance (4.57 × 10 ⁷ N · s / m ³ ), elastic properties, and excellent ink corrosion resistance, like stainless steel.

Further, in order to efficiently transmit the vibration of the electrostrictive oscillator 30 to the ink 22 or the air in the ink supply pipe 28, the electrostrictive oscillator 30 needs to be firmly fixed to the ink supply pipe 28. In the present embodiment, the electrostrictive vibrator 30 is adhered and fixed to the outer circumference of the ink supply tube 28 with an epoxy adhesive.

A specific example will be described. Ink supply pipe 2
8 was prepared by using SUS304, Pyrex glass, alumina, and silicon carbide, and the detection operation was performed. As a result, as shown in FIGS.
There is a change in the output of the voltage comparator 47 with and without the presence, and the ink end can be detected by distinguishing the two. On the other hand, when a soft polyethylene tube, a polystyrene tube, or a silicone rubber tube was prepared as the ink supply pipe 28 and the detection operation was performed, the difference depending on the presence or absence of the ink 22 as shown in FIGS. Could not be identified. In each of these specific examples, the tube or pipe has an outer diameter of 2.4 mm and an inner diameter of 1.8 mm, and the electrostrictive vibrator 30 is also tubular and has an outer diameter of 4.2 mm. The inner diameter was 2.45 mm and the length was 10 mm, and an epoxy adhesive was filled between them to cure them, and both were firmly fixed.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same parts as those shown in the above-mentioned embodiment are designated by the same reference numerals. In the above-described embodiment, the detection operation is performed by detecting the oscillating voltage of the electrostrictive vibrator 30 when the hollow region 31 is generated in the ink supply pipe 28, but in the present embodiment, the detection operation of the electrostrictive vibrator 30 is performed. The detection operation is performed by detecting the oscillating current. That is, the current
A voltage conversion circuit 49 is provided. First, the electrostrictive oscillator 30 connected between the emitter of the transistor 36 and the ground
The midpoint of connection between the resistor 38 and the resistor 38 is connected to one input terminal of the voltage comparator 50. A series circuit of a capacitor 51 and a resistor 52 is connected between the emitter of the transistor 36 and the ground, and the midpoint of the connection is connected to the other input terminal of the voltage comparator 50. The output of the voltage comparator 50 is connected to the circuit after the capacitor 42 in a state of replacing the slider of the variable resistor 41 of FIG. The capacity of the capacitor 51 is set to the same value as the electrostatic capacity of the electrostrictive vibrator 30.

In such a configuration, the electrostrictive oscillator 30 is now driven by the pulse voltage as shown in FIG.
The electrostrictive vibrator 30 is used depending on the state of the cavity inside the ink supply pipe 28.
When the current of (3) oscillates, the voltage across the resistor 38 oscillates as shown in FIG. On the other hand, the capacitor 51 and the resistor 5
The serial circuit of No. 2 receives the same pulse voltage as the series circuit of the electrostrictive oscillator 30 and the resistor 38, and the voltage across the resistor 52 has a waveform as shown in FIG. The voltage generated across each of the resistors 38 and 52 is applied to the voltage comparator 5
0, and only the vibration component as shown in FIG. 6 (d) caused by the hollow condition in the ink supply tube 28 is output from the voltage comparator 50. After that, the voltage comparison is performed as in the case of the above embodiment. The detection operation is performed by being subjected to processing by the container 47 and the like.

Here, when the waveform of the voltage across the resistor 38 and the drive pulse applied to the electrostrictive vibrator 30 are observed in detail, the ink 22 is still sufficient as shown in FIG. When the ink 22 is also clogged in 28, the state as shown in FIG. 11 is obtained, whereas the consumption of the ink 22 progresses, and as shown in FIG. In the situation where the detection portion is the cavity region 31, the waveform is as shown in FIG. As a result, it can be seen that a large oscillating voltage is generated when the inside of the ink supply tube 28 becomes hollow. 11 and 12, (a) shows the waveform of the voltage across the resistor 38, and (b) shows the drive pulse voltage applied to the electrostrictive oscillator 30.

In the above description, the ink supply pipe 28 and the electrostrictive vibrator 30 are both tube-shaped for detecting the presence or absence of ink, but the shape is not limited to this. It may have an appropriate shape.
In short, the remaining ink amount detecting means is arranged between the head chip 11 and the ink tank 27 of the ink supply unit 26, and at the detection position, the hollow area 31 is formed as the ink 22 is consumed. Anything will do. Further, the electrostrictive oscillator 30 side may be fixed to the outer periphery thereof in accordance with the shape of the ink supply pipe 28 side, and may be, for example, a flat plate type.

As a modified example, an application example to an ink jet recording head integrated with an ink tank as shown in FIGS. 13 to 15 will be described. First, an ink tank (ink storage unit) 6 is provided as a main element constituting the ink supply unit 60.
No. 1 is provided, the ink tank 61 is configured by adhering a top plate 63 to a tank body 62, and a head portion 64 is connected to the ink tank 61.

The head portion 64 includes an orifice plate 66 having a plurality of ink ejection openings 65 for ejecting the ink 22 as liquid droplets, and the orifice plate 6
6 is attached to the recording head substrate 67, and the orifice plate 66 is formed by applying Au plating on a Ni plate formed by photoelectroforming. Further, the recording head substrate 67 has an electrode portion 68 for receiving an image information signal from the outside.
And an energy acting portion 69 to which these electrode portions 68 are connected, and an ink supply port 70 for ejecting ink, which has been subjected to the action of heat energy from the energy acting portion 69, as droplets. The supply port 70 communicates with an ink supply port (connection part) 71 formed in the ink tank 61 and having a rectangular cross section. The recording head substrate 67 is one in which the thermal energy acting portion 69 and the like are formed on a silicon wafer by using a so-called semiconductor process technique such as a thin film forming technique, a photolithography technique, and an etching technique. Further, an absorber 72 for impregnating the ink 22 is housed in the ink tank 61, and a rectangular flat plate-shaped filter 73 is provided at the inlet of the ink supply port 71 in the ink tank 61. Installed. Here, the absorber 72 is
For example, it is formed of a porous and elastic material such as polyurethane foam. An atmosphere communication hole 74 is formed in a part of the ink tank 61.

Then, the head portion 64 and the ink tank 6
The electrostrictive vibrator 30 is fixed to a part of the outer circumference of the ink supply port 71 connecting with No. 1, and a hollow state is generated in the detection region of the ink supply port 71 due to ink consumption according to the above-described embodiment. The detection is performed so that it can be detected that the remaining amount of ink is low.

Although the bubble jet type ink jet is used in the above-mentioned embodiment, the ink jet recording method using the piezo element is not limited to this type and may be the ink jet recording type.

[0047]

According to the first and fifth aspects of the invention, the remaining ink amount detecting means is provided between the head portion and the ink supply portion, for example, in the middle of the connecting portion to detect the presence or absence of ink. , At least the ink can be detected as the ink near end in the state that the ink is still left in the head part, and it is possible to take measures such as ink replenishment before it can not be completely printed, and avoid downing as a printer as much as possible. can do.

According to the second aspect of the present invention, since the ink remaining amount detecting means is configured to have the electro-mechanical converter, the detection method does not come into direct contact with the ink, which causes corrosion by the ink and further thermal The influence does not have to be taken into consideration and the detection becomes highly reliable.

According to the third aspect of the present invention, the electro-mechanical converter is used, and the hollow state in which there is no ink at the detection location is detected as a change in the mechanical impedance seen from the electro-mechanical converter. , A highly reliable detection method that does not cause corrosion due to ink, and because it does not rely on optical means and does not have a dynamic element such as floating in the detection means, it is more reliable from this point as well. High detection can be made possible.

According to the fourth aspect of the present invention, the portion for transmitting the vibration of the electro-mechanical transducer to the ink or the cavity region is made of metal, glass or ceramic material, so that detection by mechanical impedance change is highly accurate. In addition, these materials also have excellent corrosion resistance as an ink supply member.

[Brief description of drawings]

1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a vertical sectional side view showing a sufficient state of ink, and FIG. 1B is a vertical sectional side view showing an ink near end state.

FIG. 2 is a vertical sectional side view showing the principle of ink flight in sequence.

FIG. 3 is a perspective view showing a chip head structure.

FIG. 4 is an exploded perspective view thereof.

FIG. 5 is a perspective view showing the lid substrate by turning it over.

FIG. 6 is a circuit diagram showing a configuration of a detection system.

FIG. 7 is a voltage waveform diagram showing the operation.

FIG. 8 is a voltage waveform diagram for sequentially explaining a detection operation.

FIG. 9 is a circuit diagram of a detection system showing a second embodiment of the present invention.

FIG. 10 is a voltage waveform diagram for sequentially explaining a detection operation.

FIG. 11 is a voltage waveform diagram when the ink is in a sufficient state.

FIG. 12 is a voltage waveform diagram at the time of ink end.

FIG. 13 is a vertical cross-sectional side view of an ink tank integrated head showing a modified example.

FIG. 14 is a perspective view thereof.

FIG. 15 is an exploded perspective view thereof.

FIG. 16 is a schematic vertical sectional side view showing a conventional example.

[Explanation of symbols]

 11 Head Part 22 Ink 26 Ink Supply Part 27 Ink Storage Part 28 Connection Part 30 Electro-Mechanical Converter = Ink Remaining Amount Detection Means 31 Cavity Area 33 Detection Part 60 Ink Supply Part 61 Ink Storage Part 64 Head Part 71 Connection Part

Claims (5)

[Claims] 1. An ink jet recording apparatus comprising a head section for ejecting ink toward a recording medium and an ink supply section connected to this head section for supplying ink.
An ink jet recording apparatus, characterized in that an ink remaining amount detecting means for detecting the presence or absence of ink is provided between the head portion and the ink supply portion. 2. The ink jet recording apparatus according to claim 1, wherein the ink remaining amount detecting means has an electro-mechanical converter. 3. The ink remaining amount detecting means is provided with a detecting section for detecting the presence or absence of ink on the upstream side of the head section based on a change in mechanical impedance viewed from an electro-mechanical converter located upstream of the head section. The inkjet recording apparatus according to claim 2, wherein the inkjet recording apparatus is provided. 4. The electro-mechanical transducer has a vibrating structure for applying a vibration to an ink or a hollow region where ink has run out through a metal, glass or ceramic material. Inkjet recording device. 5. An ink jet recording apparatus comprising a head section for ejecting ink toward a recording medium and an ink supply section connected to this head section for supplying ink.
The ink supply unit is formed by an ink storage unit that is in communication with the atmosphere and a connection unit for the head unit, and is disposed in the middle of the connection unit and reaches a cavity region associated with ink consumption, and ink on the upstream side of the head unit is reached. An ink jet recording apparatus comprising an ink remaining amount detecting means for detecting an end.