JP4655283B2 - Liquid consumption state detector - Google Patents

Description

  The present invention relates to a liquid consumption state detector capable of detecting a consumption state of a liquid such as ink by detecting a change in acoustic impedance, and in particular, detecting a change in resonance frequency.

  In an ink jet recording apparatus, an ink jet recording head having a pressure generating means for pressurizing a pressure generating chamber and a nozzle opening for ejecting the pressurized ink as ink droplets is mounted on a carriage.

  The ink jet recording apparatus is configured to be able to continue printing by continuously supplying ink in the ink tank to the recording head via the flow path. The ink tank is configured as a detachable cartridge that can be easily replaced by the user when ink is consumed, for example.

  Conventionally, the ink consumption management method of the ink cartridge includes a method of managing the ink consumption by calculating the number of ink droplets discharged from the recording head and the amount of ink sucked by the maintenance by software, or an ink cartridge. There is a method of managing a point in time when a predetermined amount of ink is actually consumed by attaching an electrode for detecting a liquid level.

  However, the method of managing the ink consumption by calculating the number of ink droplet ejections and the amount of ink by software has the following problems. Some heads have variations in weight of ejected ink droplets. Although the image quality is not affected, the ink cartridge is filled with a margin in consideration of accumulation. Therefore, depending on the individual, there is a problem that ink is left by the margin.

  On the other hand, the method of managing the time when ink is consumed by the electrode can detect the actual amount of ink. For this reason, the remaining amount of ink can be managed with high reliability. However, since the detection of the ink level depends on the conductivity of the ink, the types of ink that can be detected may be limited, and the electrode seal structure may be complicated. In addition, as a material for the electrode, a noble metal having high conductivity and high corrosion resistance is usually used, which increases the manufacturing cost of the ink cartridge. Furthermore, since it is necessary to mount two electrodes, the number of manufacturing steps increases, resulting in an increase in manufacturing cost.

  Japanese Patent Application No. 2000-147052 discloses a piezoelectric device and a module body mounted on a liquid container that can accurately detect the remaining amount of liquid and eliminate the need for a complicated seal structure in order to solve the above-mentioned problems. ing. Japanese Patent Application No. 2000-146966 discloses a detection control circuit that can be used for such a piezoelectric device and a module body.

  The inventor of the present invention has found that when the influence of noise exists, the detection control circuit according to Japanese Patent Application No. 2000-146966 makes an erroneous detection of the remaining amount of liquid.

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a liquid consumption state detector that can suppress the influence of noise and avoid erroneous detection of the remaining amount of liquid. To do.

  According to the present invention, at least a part is exposed in the storage space for storing the liquid, the vibration unit that can vibrate with respect to the storage space, and the vibration unit can be vibrated based on the drive signal. A piezoelectric element that generates a back electromotive force signal by vibration of the part, and a liquid consumption state detection unit that detects a liquid consumption state based on the back electromotive force signal from the piezoelectric element. A liquid consumption state detector comprising: a digital signal generation circuit unit that generates a digital signal based on an electromotive force signal; and a detection circuit unit that includes a clock signal that detects a liquid consumption state based on the digital signal. is there.

  According to the present invention, since the digital signal generation circuit unit generates a digital signal based on the back electromotive force signal, and the detection circuit unit detects the liquid consumption state based on the digital signal, the signal processing in the detection circuit unit is digital. It becomes processing and is not easily affected by noise.

  In particular, when the digital signal generation circuit unit is provided in the vicinity of the piezoelectric element and the clock signal is not used, the back electromotive force signal, which is an analog signal, can be immediately converted into a digital signal, and thus is further affected by noise. Hateful.

For example, the digital signal generation circuit unit is configured to generate a pulse signal having substantially the same frequency as the counter electromotive force signal as a digital signal based on the counter electromotive force signal.
More specifically, the digital signal generation circuit unit includes a voltage generation unit that generates a reference voltage, an amplification unit that amplifies the back electromotive force signal around the reference voltage, and a signal amplified by the amplification unit is a reference voltage. And a comparison unit that compares High and Low and outputs a comparison result as a pulse signal.

Alternatively, the digital signal generation circuit unit includes a voltage generation unit that generates the first reference voltage and a second reference voltage that is higher than the first reference voltage, and an amplification unit that amplifies the back electromotive force signal around the first reference voltage. A comparison unit that compares whether the signal amplified by the amplification unit is High or Low with respect to the second reference voltage, and outputs a comparison result as a pulse signal;
Can have. In this case, if the output of the comparison unit is low and constant before the vibration unit is vibrated based on the drive signal, it is determined that the influence of the noise is small. If the output of the comparison unit is not constant, the influence of the noise is determined. Can be determined to be large.

Alternatively, the digital signal generation circuit unit includes a voltage generation unit that generates a first reference voltage and a second reference voltage lower than the first reference voltage, and an amplification unit that amplifies the back electromotive force signal around the first reference voltage. A comparison unit that compares whether the signal amplified by the amplification unit is High or Low with respect to the second reference voltage, and outputs a comparison result as a pulse signal;
Can have. In this case, in the state before the vibration unit is vibrated based on the drive signal, if the output of the comparison unit is high and constant, it is determined that the influence of noise is small, and if the output of the comparison unit is not constant, the influence of noise. Can be determined to be large.

  For example, the detection circuit unit measures the frequency of the back electromotive force signal based on the pulse signal generated by the digital signal generation circuit unit. Since the frequency of the counter electromotive force signal corresponds to the resonance frequency of the substance in the accommodation space, the liquid consumption state can be detected easily and accurately.

  Specifically, the detection circuit unit has a counter that measures the number of vibrations of the pulse signal for a predetermined time, and measures the frequency of the back electromotive force signal based on the value measured by the counter. It has become.

  Alternatively, the detection circuit unit has a clock counter for measuring the time during which the pulse signal vibrates a predetermined number of times, and based on the time measured by the clock counter, the frequency of the back electromotive force signal is determined. It comes to measure.

  In addition, preferably, the portion of the vibrating portion exposed to the liquid storage space has a symmetrical shape when viewed from the liquid storage space side. The piezoelectric element is preferably fixed on the opposite side of the vibrating part from the liquid containing space at a position substantially at the center of the part exposed to the liquid containing space of the vibrating part.

  Particularly preferably, the portion of the vibrating portion exposed to the liquid storage space has a circular shape when viewed from the inner surface side of the liquid container.

  Preferably, the vibration direction of the piezoelectric element is substantially perpendicular to the portion of the vibration portion exposed to the liquid storage space.

  Note that a liquid container (for example, an ink cartridge) including a liquid consumption state detector having any of the above-described features and a wall portion that divides a storage space for storing the liquid is also subject to protection in this case. It is.

  In this case, it is preferable that the liquid container further includes a storage unit that stores the liquid consumption state detected by the liquid consumption state detector.

  Furthermore, a liquid consuming apparatus (for example, an ink jet recording apparatus) including a liquid container having the above-described features and a liquid consuming main body unit that is connected to the liquid container and consumes the liquid contained in the liquid container, This is a subject of protection.

  Alternatively, at least a portion is exposed in the storage space for storing the liquid, and the vibration unit that can vibrate with respect to the storage space and the vibration unit can be vibrated based on the drive signal. A liquid container having a piezoelectric element that generates a back electromotive force signal by vibration, a wall section that divides a storage space for storing liquid, and a liquid consumption state is detected based on the back electromotive force signal from the piezoelectric element A liquid consumption state detection unit, and a liquid consumption main body unit that is connected to the liquid container and consumes the liquid contained in the liquid container. The liquid consumption state detection unit is a digital signal based on a back electromotive force signal. A liquid consumption apparatus comprising: a digital signal generation circuit unit for generating a liquid crystal; and a detection circuit unit having a clock signal for detecting a liquid consumption state based on the digital signal. To be protected.

  In this case, the digital signal generation circuit unit is preferably installed in the liquid container at a position near the piezoelectric element.

  The liquid consuming device preferably further includes a control circuit unit that controls the liquid consuming operation in the liquid consuming main body unit based on the liquid consuming state of the liquid container detected by the liquid consuming state detecting unit.

  Alternatively, the liquid consuming device may use a storage unit that stores the liquid consumption state detected by the liquid consumption state detector, and the liquid consumption in the liquid consumption main body unit based on the liquid consumption state of the liquid container stored by the storage unit. It is preferable to further include a control circuit unit that controls the operation.

  Further, a control device for controlling a liquid consumption state detector having any of the above features, characterized in that a drive signal is given to a piezoelectric element and a liquid consumption state detection unit is detected. The control device is also subject to protection in this case.

  The control device or each element means of the control device can be realized by a computer system.

  Further, a program for causing a computer system to implement each device or each means and a computer-readable recording medium recording the program are also subject to protection in this case.

  Here, the recording medium includes not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  According to the present invention, since the digital signal generation circuit unit generates a digital signal based on the back electromotive force signal, and the detection circuit unit detects the liquid consumption state based on the digital signal, the signal processing in the detection circuit unit is digital. It becomes processing and is not easily affected by noise.

  Hereinafter, the present invention will be described in detail through embodiments of the invention. The following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are not necessarily essential to the solving means of the invention.

  The basic concept of the present invention is to use the vibration phenomenon to determine the state of the liquid in the liquid container (including the presence or absence of the liquid in the liquid container, the amount of the liquid, the level of the liquid, the type of the liquid, and the composition of the liquid). Is to detect.

  As a specific method for detecting the state of the liquid in the liquid container using the vibration phenomenon, several methods are conceivable. For example, an elastic wave is generated inside the liquid container by the elastic wave generating means, and a reflected wave reflected by the liquid surface or the opposite wall is received to detect a medium in the liquid container and a change in its state. There is a way to do it. There is also a method for detecting a change in acoustic impedance from the vibration characteristics of a vibrating object.

As a method of using a change in acoustic impedance, a vibration part of a piezoelectric device or an actuator having a piezoelectric element is vibrated, and then a counter electromotive force generated by residual vibration remaining in the vibration part is measured, whereby a resonance frequency or an inverse is obtained. There is a method for detecting a change in acoustic impedance by detecting the amplitude of an electromotive force waveform.
Alternatively, measure the impedance characteristics or admittance characteristics of the liquid with an impedance analyzer such as a transmission circuit, and change the current value or voltage value, or the frequency of the current value or voltage value when vibration is applied to the liquid. There is a method to measure changes due to.

  The details of the operation principle of the piezoelectric device or actuator will be described below. 1 and 2 show details and an equivalent circuit of an actuator 106 that is an embodiment of the piezoelectric device.

  The actuator 106 is used in a method for detecting a consumption state of a liquid in a liquid container by detecting at least a change in acoustic impedance. In particular, it is used in a method of detecting a change in acoustic impedance by detecting a resonance frequency by residual vibration and detecting a consumption state of liquid in a liquid container.

  FIG. 1A is an enlarged plan view of the actuator 106. FIG. 1B shows a BB cross section of the actuator 106. FIG. 1C shows a CC cross section of the actuator 106. 2A and 2B show an equivalent circuit of the actuator 106. FIG. 2C and 2D show the periphery including the actuator 106 and its equivalent circuit when the ink is filled in the ink cartridge, respectively, and FIGS. 2E and 2F. ) Shows the periphery including the actuator 106 and its equivalent circuit when there is no ink in the ink cartridge.

  The actuator 106 includes a substrate 178 having a circular opening 161 at substantially the center, a diaphragm 176 disposed on one surface (hereinafter referred to as a surface) of the substrate 178 so as to cover the opening 161, and the diaphragm 176. The piezoelectric layer 160 disposed on the surface side, the upper electrode 164 and the lower electrode 166 sandwiching the piezoelectric layer 160 from both sides, the upper electrode terminal 168 electrically coupled to the upper electrode 164, and the lower electrode 166 electrically A lower electrode terminal 170 to be coupled, and an auxiliary electrode 172 disposed between the upper electrode 164 and the upper electrode terminal 168 to electrically couple both are provided.

  The piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 have circular portions as their main parts. The circular portions of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element.

  The diaphragm 176 is formed on the surface of the substrate 178 so as to cover the opening 161.

The cavity 162 is formed by the portion of the diaphragm 176 that faces the opening 161 and the opening 161 of the substrate 178. The surface of the substrate 178 opposite to the piezoelectric element (hereinafter referred to as the back surface) faces the inside of the liquid container. Thereby, the cavity 162 is configured to come into contact with the liquid. Note that the diaphragm 176 is liquid-tightly attached to the substrate 178 so that the liquid does not leak to the surface side of the substrate 178 even if the liquid enters the cavity 162.

  The lower electrode 166 is located on the surface of the diaphragm 176 (the surface on the side opposite to the liquid container). The center of the circular portion which is the main part of the lower electrode 166 and the center of the opening 161 are attached so as to substantially coincide. The area of the circular portion of the lower electrode 166 is set to be smaller than the area of the opening 161.

  On the other hand, on the surface side of the lower electrode 166, the piezoelectric layer 160 is arranged (formed) so that the center of the circular portion and the center of the opening 161 substantially coincide. In this case, the area of the circular portion of the piezoelectric layer 160 is set to be smaller than the area of the opening 161 and larger than the area of the circular portion of the lower electrode 166.

  On the other hand, on the surface side of the piezoelectric layer 160, the upper electrode 164 is arranged (formed) so that the center of the circular portion, which is the main portion thereof, and the center of the opening 161 substantially coincide. The area of the circular portion of the upper electrode 164 is set to be smaller than the area of the circular portion of the opening 161 and the piezoelectric layer 160 and larger than the area of the circular portion of the lower electrode 166.

  Therefore, the main part of the piezoelectric layer 160 has a structure sandwiched between the main part of the upper electrode 164 and the main part of the lower electrode 166 from the front surface side and the back surface side, respectively. Thereby, the piezoelectric layer 160 can be effectively deformed and driven. The circular portions that are the main parts of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element in the actuator 106.

  As described above, such a piezoelectric element is in contact with the diaphragm 176. Of the circular portion of the upper electrode 164, the circular portion of the piezoelectric layer 160, the circular portion of the lower electrode 166, and the opening 161, the opening 161 has the largest area. Due to such a structure, the vibration region of the diaphragm 176 that actually vibrates is determined by the opening 161.

  Further, since the areas of the circular portion of the upper electrode 164, the circular portion of the piezoelectric layer 160, and the circular portion of the lower electrode 166 are smaller than the area of the opening 161, the vibration plate 176 is more likely to vibrate.

  Furthermore, of the circular portion of the lower electrode 166 and the circular portion of the upper electrode 164 that are electrically connected to the piezoelectric layer 160, the circular portion of the lower electrode 166 is smaller. Accordingly, the circular portion of the lower terminal 166 determines a portion of the piezoelectric layer 160 that generates a piezoelectric effect.

  The centers of the circular portions of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 that form the piezoelectric element substantially coincide with the center of the opening 161. In addition, the center of the circular opening 161 that determines the vibration portion of the diaphragm 176 is located substantially at the center of the entire actuator 106. Therefore, the center of the vibration part of the actuator 106 substantially matches the center of the actuator.

  Furthermore, since the main part of the piezoelectric element and the vibration part of the diaphragm 176 have a circular shape, the vibration part of the actuator 106 has a symmetrical shape with respect to the center of the actuator 106.

  Since the vibration part has a symmetrical shape with respect to the center of the actuator 106, unnecessary vibration that may be caused by the asymmetry of the structure is not excited. For this reason, the detection accuracy of the resonance frequency is improved.

  Furthermore, since the vibrating portion has a symmetrical shape with respect to the center of the actuator 106, the manufacturing is easy, and the variation in shape of each piezoelectric element can be reduced. Therefore, the variation in the resonance frequency for each piezoelectric element is reduced.

  In addition, since the vibrating part has an isotropic shape, it is less susceptible to variations in fixation during bonding and can be evenly bonded to the liquid container. That is, the mountability of the actuator 106 on the liquid container is good.

Further, since the vibration portion of the diaphragm 176 has a circular shape, a low-order, for example, primary resonance mode is dominant in the resonance mode of the residual vibration of the piezoelectric layer 160.
That is, a single peak appears in the resonance mode of residual vibration. Therefore, since the peak and the noise can be clearly distinguished, the resonance frequency can be clearly detected.

  In addition, by increasing the area of the vibration part of the circular diaphragm 176, the difference between the amplitude of the back electromotive force waveform and the resonance frequency due to the presence or absence of liquid increases, and the accuracy of detection of the resonance frequency can be further improved. .

  The displacement due to the vibration of the diaphragm 176 is much larger than the displacement due to the vibration of the substrate 178. That is, the actuator 106 has a two-layer structure of a substrate 178 with small compliance (not easily displaced by vibration) and a diaphragm 176 with large compliance (easy to be displaced by vibration). With this two-layer structure, the displacement of the diaphragm 176 can be increased while being securely fixed to the liquid container by the substrate 178. For this reason, the difference between the amplitude of the back electromotive force waveform and the amplitude of the resonance frequency due to the presence or absence of liquid increases, and the accuracy of detection of the resonance frequency can be improved.

  Furthermore, since the compliance of the diaphragm 176 is large, the attenuation of vibration is reduced, and the accuracy of detecting the resonance frequency can be improved.

  The vibration node of the actuator 106 is located in the outer peripheral portion of the cavity 162, that is, in the vicinity of the edge of the opening 161.

  The upper electrode terminal 168 is formed on the surface side of the diaphragm 176 so as to be electrically connected to the upper electrode 164 through the auxiliary electrode 172. On the other hand, the lower electrode terminal 170 is formed on the surface side of the diaphragm 176 so as to be electrically connected to the lower electrode 166. Since the upper electrode 164 is formed on the surface side of the piezoelectric layer 160, it is necessary to have a step equal to the sum of the thickness of the piezoelectric layer 160 and the thickness of the lower electrode 166 in the middle of connection with the upper electrode terminal 168. It is difficult to form this step with the upper electrode 164 alone. Even if it is possible to form a step with only the upper electrode 164, the connection state between the upper electrode 164 and the upper electrode terminal 168 is weakened and there is a risk of disconnection. Therefore, the upper electrode 164 and the upper electrode terminal 168 are connected using the auxiliary electrode 172 as an auxiliary member. By doing so, the piezoelectric layer 160 and the upper electrode 164 are both supported by the auxiliary electrode 172, so that a desired mechanical strength can be obtained, and the connection between the upper electrode 164 and the upper electrode terminal 168 can be achieved. It is possible to ensure.

  The vibration region facing the piezoelectric element in the piezoelectric element and the diaphragm 176 is a vibration part that actually vibrates in the actuator 106. Moreover, it is preferable that the members included in the actuator 106 are integrally formed by firing each other. By integrally forming the actuator 106, the handling of the actuator 106 becomes easy.

  Further, the vibration characteristics can be improved by increasing the strength of the substrate 178. That is, by increasing the strength of the substrate 178, only the vibration portion of the actuator 106 vibrates, and portions other than the vibration portion of the actuator 106 do not vibrate. In order not to vibrate parts other than the vibration part of the actuator 106, in addition to increasing the strength of the substrate 178, it is also effective to make the piezoelectric element of the actuator 106 thinner and smaller and to make the diaphragm 176 thinner. is there.

  As a material of the piezoelectric layer 160, it is preferable to use lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), or a lead-less piezoelectric film that does not use lead. As a material for the substrate 178, zirconia or alumina is preferably used. Further, it is preferable to use the same material as the substrate 178 for the diaphragm 176. For the upper electrode 164, the lower electrode 166, the upper electrode terminal 168, and the lower electrode terminal 170, a conductive material, for example, a metal such as gold, silver, copper, platinum, aluminum, or nickel can be used.

  The actuator 106 configured as described above can be applied to a container that contains a liquid. For example, it can be mounted on an ink cartridge or an ink tank used in an ink jet recording apparatus, or a container containing a cleaning liquid for cleaning the recording head.

  The actuator 106 shown in FIGS. 1 and 2 is mounted at a predetermined position of the liquid container so that the cavity 162 contacts the liquid contained in the liquid container. When the liquid is sufficiently contained in the liquid container, the inside of the cavity 162 and the outside thereof are filled with the liquid.

  On the other hand, when the liquid in the liquid container is consumed and the liquid level drops below the mounting position of the actuator, there is no liquid in the cavity 162, or the liquid remains only in the cavity 162 and gas is present outside the cavity 162. Exists.

  The actuator 106 detects at least a difference in acoustic impedance caused by the change in the state. Thereby, the actuator 106 can detect whether the liquid is sufficiently contained in the liquid container or whether a certain amount of liquid is consumed. Furthermore, the actuator 106 can also detect the type of liquid in the liquid container.

Here, the principle of the liquid level detection by the actuator will be described.
In order to detect a change in the acoustic impedance of the medium, the impedance characteristic or admittance characteristic of the medium is measured. When measuring impedance characteristics or admittance characteristics, for example, a transmission circuit can be used. The transmission circuit applies a periodic voltage having a constant amplitude to the medium, changes the frequency, and measures the current flowing through the medium. Alternatively, the transmission circuit supplies a periodic current having a constant amplitude to the medium, and changes the frequency to measure the voltage of the medium. A change in current value or voltage value measured in the transmission circuit indicates a change in acoustic impedance. In addition, a change in the frequency fm at which the current value or voltage value is maximized or minimized also indicates a change in acoustic impedance.

  Apart from the above method, the actuator 106 can detect the change in the acoustic impedance of the liquid using the change in the resonance frequency. The resonance frequency can be detected, for example, by measuring a counter electromotive force generated by residual vibration remaining in the vibration part after the vibration part of the actuator vibrates. In this case, for example, the piezoelectric element as described above can be used.

  The piezoelectric element generates a counter electromotive force due to residual vibration remaining in the vibration portion of the actuator. The magnitude of the back electromotive force varies depending on the amplitude of the vibration part of the actuator. Therefore, the larger the amplitude of the vibration part of the actuator, the easier the detection. Further, the period in which the magnitude of the back electromotive force changes depends on the frequency of residual vibration in the vibration part of the actuator. That is, the frequency of the vibration part of the actuator corresponds to the frequency of the counter electromotive force. Here, the resonance frequency is a frequency in a resonance state between the vibration part of the actuator and the medium in contact with the vibration part.

  In order to obtain the resonance frequency fs, the waveform obtained by measuring the counter electromotive force when the vibration part and the medium are in the resonance state is subjected to Fourier transform. The vibration of the actuator is not only deformed in one direction but is accompanied by various deformations such as deflection and extension, and therefore has various frequencies including the resonance frequency fs. Therefore, the resonance frequency fs is determined by Fourier-transforming the back electromotive force waveform when the piezoelectric element (vibrating unit) and the medium are in a resonance state and specifying the most dominant frequency component.

  The frequency fm when the admittance of the medium is maximum or the impedance is minimum is slightly different from the resonance frequency fs due to dielectric loss or mechanical loss of the medium. However, since it takes time to derive the resonance frequency fs from the actually measured frequency fm, the frequency fm is generally used instead of the resonance frequency fs. Here, by inputting the output of the actuator 106 to the transmission circuit, the actuator 106 can detect at least the acoustic impedance.

  It is specified by the method of measuring the frequency fm by measuring the impedance characteristic or admittance characteristic of the medium, and the method of measuring the resonance frequency fs by measuring the counter electromotive force generated by the residual vibration vibration in the vibration part of the actuator. Experiments have proved that there is almost no difference in the resonance frequency.

  The vibration region of the actuator 106 is a portion constituting the cavity 162 determined by the opening 161 of the vibration plate 176. When the liquid is sufficiently stored in the liquid container, the cavity 162 is filled with the liquid, and the vibration region is in contact with the liquid in the liquid container. On the other hand, when there is not enough liquid in the liquid container, the vibration region is in contact with the liquid remaining in the cavity in the liquid container, or is not in contact with the liquid but is in contact with gas or vacuum.

  The actuator 106 of the present invention is provided with a cavity 162. Thereby, it can design so that the liquid in a liquid container may remain in the vibration area | region of the actuator 106. FIG. The reason is as follows.

  Depending on the mounting position and mounting angle of the actuator 106 to the liquid container, the liquid may adhere to the vibration region of the actuator even though the liquid level of the liquid in the liquid container is below the mounting position of the actuator There is. When detecting the presence / absence of liquid only from the presence / absence of liquid in the vibration region, the liquid adhering to the vibration region of the actuator in this way prevents accurate detection of the presence / absence of the liquid.

  For example, when the liquid level is below the mounting position of the actuator, if the liquid container is swung due to the reciprocating movement of the carriage, etc. An erroneous determination is made that there is sufficient liquid in the liquid container.

  Therefore, in the actuator 106, even if the liquid remains in the vibration region, the cavity is positively provided so as to accurately detect the presence or absence of the liquid, so that the liquid container is swung and the liquid surface is waved. Even if it stands, the malfunction of the actuator can be prevented. In this manner, malfunctions can be prevented by using an actuator having a cavity.

Further, as shown in FIG. 2E, the case where there is no liquid in the liquid container and the liquid remains in the cavity 162 of the actuator 106 is set as a threshold value for the presence or absence of the liquid.
That is, if there is no liquid around the cavity 162 and there is less liquid in the cavity than this threshold, it is determined that there is no ink. If there is liquid around the cavity 162 and there is more liquid than this threshold, ink is present. to decide.

  For example, when the actuator 106 is mounted on the side wall of the liquid container, it is determined that there is no ink when the liquid in the liquid container is below the mounting position of the actuator, and the liquid in the liquid container is above the mounting position of the actuator. In some cases, it is determined that ink is present.

  By setting the threshold in this way, it can be determined that there is no ink even when the ink in the cavity has dried and the ink has run out. Even if ink adheres to the cavity again (because the threshold value is not exceeded), it can be determined that there is no ink.

  Here, with reference to FIG. 1 and FIG. 2, the operation and principle of detecting the state of the liquid in the liquid container from the resonance frequency of the medium obtained by measuring the back electromotive force and the vibration part of the actuator 106 will be described. .

In the actuator 106, a voltage is applied to the upper electrode 164 and the lower electrode 166 via the upper electrode terminal 168 and the lower electrode terminal 170, respectively.
For this reason, an electric field is generated in a portion of the piezoelectric layer 160 sandwiched between the upper electrode 164 and the lower electrode 166. The piezoelectric layer 160 is deformed by this electric field. When the piezoelectric layer 160 is deformed, the vibration region of the vibration plate 176 is flexibly vibrated. For a while after the piezoelectric layer 160 is deformed, the flexural vibration remains in the vibration portion of the actuator 106.

  The residual vibration is free vibration between the vibration part of the actuator 106 and the medium. Therefore, by setting the voltage applied to the piezoelectric layer 160 to a pulse waveform or a rectangular wave, it is possible to easily obtain a resonance state between the vibrating portion and the medium after the voltage is applied. Residual vibration is vibration of the vibration part of the actuator 106 and is accompanied by deformation of the piezoelectric layer 160. For this reason, the piezoelectric layer 160 generates a counter electromotive force. This counter electromotive force is detected through the upper electrode 164, the lower electrode 166, the upper electrode terminal 168 and the lower electrode terminal 170. The resonance frequency can be specified by the detected back electromotive force. Based on this resonance frequency, the state of the liquid in the liquid container can be detected.

In general, the resonant frequency fs is
fs = 1 / (2 × π × (M × Cact) ^1/2 ) (Formula 1)
It is represented by Here, M is the sum of the inertance Mact and the additional inertance M ′ of the vibration part. Cact is the compliance of the vibration part.

  FIG. 1C is a cross-sectional view of the actuator 106 when no ink remains in the cavity 162 in this embodiment. FIGS. 2A and 2B are equivalent circuits of the vibrating portion of the actuator 106 and the cavity 162 when no ink remains in the cavity.

Mact is obtained by dividing the product of the thickness of the vibration part and the density of the vibration part by the area of the vibration part. Specifically, as shown in FIG.
Mact = Mpzt + Melectrode1 + Melectrode2 + Mvib (Formula 2)
It is expressed.

  Here, Mpzt is obtained by dividing the product of the thickness of the piezoelectric layer 160 and the density of the piezoelectric layer 160 in the vibrating portion by the area of the piezoelectric layer 160. Melectrode1 is obtained by dividing the product of the thickness of the upper electrode 164 and the density of the upper electrode 164 in the vibrating portion by the area of the upper electrode 164. Melectrode2 is obtained by dividing the product of the thickness of the lower electrode 166 and the density of the lower electrode 166 in the vibrating portion by the area of the lower electrode 166. Mvib is obtained by dividing the product of the thickness of the diaphragm 176 and the density of the diaphragm 176 in the vibration section by the area of the vibration region of the diaphragm 176.

  However, the area of each of the vibration regions of the piezoelectric layer 160, the upper electrode 164, the lower electrode 166, and the diaphragm 176 can be calculated so that Mact can be calculated from the thickness, density, and area of the entire vibration part. Although having such a magnitude relationship, the difference in mutual area is preferably small.

  In the present embodiment, in the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166, it is preferable that portions other than the circular portion, which is the main portion thereof, are so small as to be negligible with respect to the main portion. Accordingly, in the actuator 106, Mact is the sum of the inertances of the vibration regions of the upper electrode 164, the lower electrode 166, the piezoelectric layer 160 and the vibration plate 176. The compliance Cact is a compliance of a portion formed by the vibration region of the upper electrode 164, the lower electrode 166, the piezoelectric layer 160, and the vibration plate 176.

2A, FIG. 2B, FIG. 2D, and FIG. 2F show equivalent circuits of the vibrating portion of the actuator 106 and the cavity 162. In these equivalent circuits, Cact is The compliance of the vibration part of the actuator 106 is shown. Cpzt, Celectrode1, Celectrode2, and Cvib indicate the compliance of the piezoelectric layer 160, the upper electrode 164, the lower electrode 166, and the diaphragm 176 in the vibrating part, respectively. Cact is expressed by Equation 3 below.
1 / Cact = (1 / Cpzt) + (1 / Celectrode1) + (1 / Celectrode2)
+ (1 / Cvib) (Formula 3)
From Equation 2 and Equation 3, FIG. 2A can also be expressed as FIG.

  The compliance Cact represents the volume of the medium that can be received by deformation when pressure is applied to the unit area. That is, the compliance Cact represents the ease of deformation.

FIG. 2C shows a cross-sectional view of the actuator 106 when the liquid is sufficiently contained in the liquid container and the liquid is filled around the vibration region of the actuator 106. M′max in FIG. 2C is an additional inertance (additional mass (which affects the vibration in the vibration region) when the liquid is sufficiently contained in the liquid container and the periphery of the vibration region of the actuator 106 is filled with the liquid. Mass)) divided by the square of the area). M'max is
M′max = (π × ρ / (2 × k ³ )) × (2 × (2 × k × a) ³ / (3 × π)) / (π × a ² ) ² (Formula 4) (a is (The radius of the vibration part, ρ is the density of the medium, and k is the wave number.)
It is represented by

  Equation 4 is established when the vibration region of the actuator 106 is a circle having a radius a. The additional inertance M ′ is an amount indicating that the mass of the vibration part is apparently increased by the medium in the vicinity of the vibration part. As can be seen from Equation 4, M′max varies greatly depending on the radius a of the vibrating part and the density ρ of the medium.

Wave number k is
k = 2 × π × fact / c (Formula 5)
(Fact is the resonance frequency of the vibration part. C is the speed of sound propagating in the medium.)
It is represented by

  FIG. 2D shows an equivalent circuit of the vibration part of the actuator 106 and the cavity 162 in the case of FIG. 2C where the liquid is sufficiently contained in the liquid container and the liquid is filled around the vibration region of the actuator 106. Indicates.

  FIG. 2E is a cross-sectional view of the actuator 106 when the liquid in the liquid container is consumed and there is no liquid around the vibration region of the actuator 106, but the liquid remains in the cavity 162 of the actuator 106. Show.

Equation 4 represents the maximum inertance M′max determined from the ink density ρ and the like when the liquid container is filled with liquid. On the other hand, when the liquid in the liquid container is consumed and the liquid remaining in the cavity 162 and the liquid around the vibration region of the actuator 106 is replaced with gas or vacuum, the additional inertance M ′ is generally ,
M ′ = ρ × t / S (Formula 6)
(For more details, see Equation 8 below.) Here, t is the thickness of the medium involved in vibration. S is the area of the vibration region of the actuator 106. When the vibration region is a circle having a radius a, S = π × a ² .

  Therefore, the additional inertance M ′ is based on Equation 4 when the liquid is sufficiently contained in the liquid container and the liquid is filled around the vibration region of the actuator 106. On the other hand, when the liquid is consumed and the liquid around the vibration region of the actuator 106 is replaced with gas or vacuum while the liquid remains in the cavity 162, Equation 6 is satisfied.

  Here, as shown in FIG. 2E, the liquid in the liquid container is consumed and there is no liquid around the vibration region of the actuator 106, but the liquid remains in the cavity 162 of the actuator 106. The inertance M ′ is referred to as M′cav for the sake of convenience, and is distinguished from the additional inertance M′max when the periphery of the vibration region of the actuator 106 is filled with liquid.

  FIG. 2F shows the case of FIG. 2E in which the liquid in the liquid container is consumed and there is no liquid around the vibration region of the actuator 106, but the liquid remains in the cavity 162 of the actuator 106. 3 shows an equivalent circuit of the vibrating portion of the actuator 106 and the cavity 162.

  Here, the parameters related to the state of the medium are the density ρ of the medium and the thickness t of the medium in Equation 6. When the liquid is sufficiently stored in the liquid container, the liquid comes into contact with the vibrating portion of the actuator 106. On the other hand, when the liquid is not sufficiently stored in the liquid container, the liquid remains in the cavity, or gas or vacuum contacts the vibrating portion of the actuator 106. The additional inertance M′var in the process of shifting from M′max in FIG. 2C to M′cav in FIG. 2E is consumed depending on the liquid accommodation state in the liquid container. It changes as the density ρ of the medium and the thickness t of the medium change. Thereby, the resonance frequency fs also changes. Therefore, by specifying the resonance frequency fs, it is possible to detect the storage state (presence / absence) of the liquid in the liquid container.

Here, when t = d as shown in FIG. 2 (E), when M′cav is expressed using Equation 6, the cavity depth d is substituted for t in Equation 6,
M′cav = ρ × d / S (Formula 7)
It becomes.

  Further, if the medium is a different type of liquid, the density ρ varies depending on the composition, and therefore the additional inertance M ′ and the resonance frequency fs are different. Therefore, the type of liquid can be detected by specifying the resonance frequency fs.

  FIG. 3A is a graph showing the relationship between the amount of ink in the ink tank and the resonance frequency fs of the ink and the vibration part. Here, ink will be described as an example of liquid. The vertical axis represents the resonance frequency fs, and the horizontal axis represents the ink amount. When the ink composition is constant, the resonance frequency fs increases as the remaining ink amount decreases.

  When ink is sufficiently contained in the ink container and the ink is filled around the vibration region of the actuator 106, the maximum additional inertance M'max is a value expressed by Equation 4. On the other hand, when the ink is consumed and the liquid remains in the cavity 162, but the ink is not filled around the vibration region of the actuator 106, the additional inertance M′var is expressed by Equation 6 based on the thickness t of the medium. Is calculated by Since t in Equation 6 is the thickness of the medium involved in the vibration, d (see FIG. 1B) of the cavity 162 of the actuator 106 where the liquid remains is made small, that is, the substrate 178 is made sufficiently thin. Thus, it is possible to detect a process in which the ink is gradually consumed (see FIG. 2C). Here, tink is the thickness of ink involved in vibration, and tink-max is the tink at M'max.

  For example, the actuator 106 is disposed substantially horizontally with respect to the ink level on the bottom surface of the ink cartridge. In this case, when the ink is consumed and the liquid level of the ink falls below the height of tink-max from the actuator 106, M'var gradually changes according to Equation 6, and the resonance frequency fs gradually changes according to Equation 1. Therefore, as long as the ink level is within the range t, the actuator 106 can gradually detect the ink consumption state.

  Alternatively, the actuator 106 may be disposed on the side wall of the ink cartridge substantially perpendicular to the ink level. In this case, when the ink is consumed and the ink level reaches the vibration region of the actuator 106, the additional inertance M 'decreases as the water level decreases. As a result, the resonance frequency fs gradually increases according to Equation 1. Therefore, as long as the ink level is within the range of the diameter 2a of the cavity 162 (see FIG. 2C), the actuator 106 can gradually detect the ink consumption state.

  A curve X in FIG. 3A shows an ink tank when the cavity 162 of the actuator 106 disposed on the bottom surface is sufficiently shallow, or when the vibration region of the actuator 106 disposed on the side wall is sufficiently large or long. The relationship between the amount of ink accommodated in the ink and the resonance frequency fs of the ink and the vibration part is shown. It can be understood that the amount of ink in the ink tank decreases and the resonance frequency fs of the ink and the vibration part gradually changes.

  More specifically, the case where the process in which ink is gradually consumed can be detected refers to the case where both liquid and gas having different densities exist around the vibration region of the actuator 106 and are involved in vibration. It is. As the ink is gradually consumed, the medium involved in the vibration around the vibration region of the actuator 106 increases the gas while decreasing the liquid.

For example, when the actuator 106 is disposed horizontally with respect to the ink surface and when tink is smaller than tink-max, the medium involved in the vibration of the actuator 106 includes both ink and gas. Therefore, using the area S of the vibration region of the actuator 106, the state of M′max or less in Equation 4 is expressed by the added mass of ink and gas.
M ′ = M′air + M′ink = ρair × tair / S + ρink × tink / S (Equation 8) Here, M′air is an inertance of air, and M′ink is an inertance of ink. ρair is the density of air, and ρink is the density of ink. tair is the thickness of air involved in vibration, and tink is the thickness of ink involved in vibration.

  Among the media involved in vibration around the vibration region of the actuator 106, as the liquid decreases and the gas increases, the tair increases when the actuator 106 is arranged substantially horizontally with respect to the ink surface. Tink decreases. Thereby, M′var gradually decreases and the resonance frequency gradually increases. Therefore, it is possible to detect the amount of ink remaining in the ink tank or the amount of ink consumed. The reason why only the liquid density is calculated in Expression 7 is that it is assumed that the air density is negligibly small relative to the liquid density.

In the case where the actuator 106 is disposed substantially perpendicular to the ink liquid level, the medium that is involved in the vibration of the actuator 106 is the ink only area and the medium that is involved in the vibration of the actuator 106 in the vibration area of the actuator 106. It is considered as an equivalent circuit (not shown) in parallel with the gas-only region. If the medium related to the vibration of the actuator 106 is Sink and the area of the medium only related to the vibration of the actuator 106 is Sair, then Sair.
1 / M ′ = 1 / M′air + 1 / M′ink = Sair / (ρair × tair) + Sink / (ρink × tink)
(Formula 9)
It becomes.

  Equation 9 is applied when ink is not held in the cavity of the actuator 106. The additional inertance when ink is held in the cavity of the actuator 106 can be calculated by the sum of M ′ according to Equation 9 and M′cav according to Equation 7.

  Since the vibration of the actuator 106 changes from the depth of tink-max to the depth (d) where ink remains, the actuator 106 is arranged on the bottom surface so that the ink remaining depth is slightly smaller than tink-max. If this is the case, it is not possible to detect a process in which the ink gradually decreases. In this case, it is detected that the ink amount has changed from the vibration change of the actuator due to a slight change in the ink amount from tink-max to the remaining depth d. Also, when the diameter of the opening (cavity) is small, the vibration change of the actuator while passing through the opening is small, so it is difficult to detect the ink amount in the passing process, and the ink liquid level is Detect whether it is above or below the opening.

  For example, the curve Y in FIG. 3A shows the relationship between the amount of ink in the ink tank and the resonance frequency fs of the ink and the vibration part in the case of a small circular vibration region. A state is shown in which the resonance frequency fs of the ink and the vibration part changes drastically between the difference Q of the ink amount before and after the ink level in the ink tank passes through the mounting position of the actuator. From this, it is possible to binaryly detect whether or not a predetermined amount of ink remains in the ink tank.

  The method of detecting the presence / absence of liquid using the actuator 106 detects the presence / absence of ink by the diaphragm 176 coming into direct contact with the liquid, and therefore has higher detection accuracy than the method of calculating the ink consumption by software. . Furthermore, the method of detecting the presence or absence of ink by conductivity using an electrode can be affected by the position of the electrode attached to the liquid container and the type of ink, but the method of detecting the presence or absence of liquid using the actuator 106 is It is hard to be influenced by the attachment position of the actuator 106 to the liquid container and the type of ink.

  Furthermore, since both oscillation and detection of the presence / absence of liquid can be performed using a single actuator 106, compared with a method in which oscillation and detection of the presence / absence of liquid are performed using different sensors. The number of sensors attached to the liquid container can be reduced. Therefore, the liquid container can be manufactured at a low cost. In addition, it is preferable that the sound generated during the operation of the actuator 106 is made quiet by setting the vibration frequency of the piezoelectric layer 160 in a non-audible region.

  FIG. 3B shows an example of the relationship between the ink density and the resonance frequency fs of the ink and the vibration part. Here, ink is described as an example of the liquid, and “ink full” and “ink empty” mean two relative states, and do not mean a so-called ink full state and an ink end state. As shown in FIG. 3B, when the ink density is high, the added inertance increases, and therefore the resonance frequency fs decreases. That is, the resonance frequency fs varies depending on the type of ink. Therefore, by measuring the resonance frequency fs, it is possible to confirm whether or not inks having different densities are mixed when refilling the ink. That is, it is possible to identify ink tanks containing different types of ink.

  Subsequently, when the size and shape of the cavity are set so that the liquid remains in the cavity 162 of the actuator 106 even when the liquid in the liquid container is empty, the condition for accurately detecting the liquid state is set. Detailed description. If the actuator 106 can detect the liquid state when the cavity 162 is filled with the liquid, the actuator 106 can detect the liquid state even when the cavity 162 is not filled with the liquid.

The resonance frequency fs is a function of the inertance M. The inertance M is the sum of the inertance Mact and the additional inertance M ′ of the vibration part. Here, the additional inertance M ′ is related to the liquid state. The additional inertance M ′ is an amount indicating that the mass of the vibration part is apparently increased by the medium in the vicinity of the vibration part.
That is, it means an increase in the mass of the vibration part due to apparent absorption of the medium by the vibration of the vibration part (inertance related to vibration increases).

  Accordingly, when M ′ cav is larger than M ′ max in Equation 4, all of the apparently absorbing medium is the liquid remaining in the cavity 162. Therefore, it is the same as the state where the liquid container is filled with the liquid. In this case, since the medium related to vibration does not become smaller than M'max, a change cannot be detected even if ink is consumed.

  On the other hand, when M ′ cav is smaller than M ′ max in Equation 4, the apparently absorbing medium is the liquid remaining in the cavity 162 and the gas or vacuum in the liquid container. At this time, unlike the state where the liquid container is filled with the liquid, M ′ changes, so the resonance frequency fs changes. Therefore, the actuator 106 can detect the state of the liquid in the liquid container.

  That is, when the liquid in the liquid container is empty and the liquid remains in the cavity 162 of the actuator 106, the condition under which the actuator 106 can accurately detect the liquid state is that M′cav is higher than M′max. It is small. The condition M′max> M′cav that allows the actuator 106 to accurately detect the liquid state is not related to the shape of the cavity 162.

Here, M′cav is the mass inertance of the liquid having a volume approximately equal to the volume of the cavity 162. Therefore, from the inequality of M′max> M′cav, the condition under which the actuator 106 can accurately detect the liquid state can be expressed as the condition of the capacity of the cavity 162. For example, when the radius of the opening 161 of the circular cavity 162 is a and the depth of the cavity 162 is d,
M′max> ρ × d / πa ² (Formula 10)
It is. When Expression 10 is expanded, a / d> 3 × π / 8 (Expression 11)
This condition is required. Therefore, if the actuator 106 has the cavity 162 having the radius a of the opening 161 and the depth d of the cavity 162 satisfying Expression 11, the liquid in the liquid container is in an empty state, and the liquid is contained in the cavity 162. Even if it remains, the liquid state can be detected without malfunction.

Expressions 10 and 11 are valid only when the shape of the cavity 162 is circular. If the shape of the cavity 162 is not circular, the corresponding relationship between the dimensions such as the width and length of the cavity and the depth can be obtained by calculating the corresponding M′max equation and replacing πa ^{2 in} Equation 10 with the area. Can be derived.

  Since the additional inertance M ′ also affects the acoustic impedance characteristics, it can be said that the method of measuring the counter electromotive force generated in the actuator 106 due to residual vibration detects at least a change in acoustic impedance.

  Further, according to this embodiment, the actuator 106 generates vibration, and the back electromotive force generated in the actuator 106 due to the subsequent residual vibration is measured. However, it is not always necessary for the vibrating portion of the actuator 106 to vibrate the liquid by its own vibration caused by the drive voltage. That is, even if the vibration part does not oscillate by itself, the piezoelectric layer 160 bends and deforms if it vibrates with a certain range of liquid in contact therewith. This deflection deformation generates a counter electromotive force voltage and transmits the counter electromotive force voltage to the upper electrode 164 and the lower electrode 166. The state of the medium may be detected by using this phenomenon. For example, in an ink jet recording apparatus, the state of the ink tank or the ink in the ink tank is detected by using the vibration around the vibration part of the actuator that occurs as the carriage reciprocates by scanning the print head during printing. Also good.

  4 (A), 4 (B), and 4 (C) show the residual vibration waveform of the actuator 106 and the method for measuring the residual vibration after the actuator 106 is vibrated. The upper and lower levels of the ink water level at the mounting position level of the actuator 106 in the ink cartridge can be detected by a change in the frequency or amplitude of the residual vibration after the actuator 106 oscillates. 4A to 4C, the vertical axis represents the voltage of the counter electromotive force generated by the residual vibration of the actuator 106, and the horizontal axis represents time. The residual vibration of the actuator 106 generates a voltage analog signal waveform as shown in FIGS. Next, the analog signal is converted into a digital numerical value corresponding to the frequency of the signal. In the example shown in FIGS. 4A to 4C, the time for generating four pulses from the fourth pulse to the eighth pulse of the analog signal is measured.

  More specifically, after the actuator 106 oscillates, the number of times that a predetermined reference voltage set in advance is crossed from the low voltage side to the high voltage side is counted. Then, a digital signal is generated with High between 4 counts and 8 counts, and the time from 4 counts to 8 counts is measured by a predetermined clock pulse.

  FIG. 4A shows a waveform when the ink liquid level is higher than the mounting position level of the actuator 106. On the other hand, FIG. 4B shows a waveform when there is no ink at the mounting position level of the actuator 106. Comparing FIG. 4 (A) and FIG. 4 (B), it can be seen that FIG. 4 (A) has a longer time from 4 to 8 counts than FIG. 4 (B). In other words, the time from 4 counts to 8 counts varies depending on the presence or absence of ink. By using this time difference, it is possible to detect the ink consumption state.

  The reason for counting from the fourth count of the analog waveform is to start measurement after the vibration of the actuator 106 is stabilized. The count from the fourth count is merely an example, and the count may be counted from an arbitrary count. Here, signals from the 4th count to the 8th count are detected, and the time from the 4th count to the 8th count is measured by a predetermined clock pulse. Based on this time, the resonance frequency can be determined. For example, the clock pulse is a pulse of a clock equal to a clock for controlling a semiconductor memory device or the like attached to the ink cartridge. Further, it is not necessary to measure the time up to the eighth count, and it may be counted up to an arbitrary count. In FIG. 4, the time from the 4th count to the 8th count is measured, but the time within different count intervals may be detected according to the circuit configuration for detecting the frequency.

  For example, when the ink quality is stable and the fluctuation of the peak amplitude is small, the resonance frequency may be obtained by detecting the time from the 4th count to the 6th count in order to increase the detection speed. . When the ink quality is unstable and the fluctuation of the pulse amplitude is large, the time from the 4th count to the 12th count may be detected in order to accurately detect the residual vibration.

  As another example, the wave number of the voltage waveform of the counter electromotive force within a predetermined period may be counted (not shown). The resonance frequency can also be obtained by this method. More specifically, after the actuator 106 oscillates, a digital signal that is High for a predetermined period is generated, and the number of times the predetermined reference voltage is crossed from the low voltage side to the high voltage side in the predetermined period is counted. The presence or absence of ink can be detected by measuring the count number.

  Further, as can be seen by comparing FIG. 4A and FIG. 4B, the amplitude of the back electromotive force waveform between when the ink is filled in the ink cartridge and when the ink is not inside the ink cartridge. Is different. Therefore, the ink consumption state in the ink cartridge may be detected by measuring the amplitude of the back electromotive force waveform without obtaining the resonance frequency.

  More specifically, for example, a reference voltage is set between the peak of the counter electromotive force waveform in FIG. 4A and the peak of the counter electromotive force waveform in FIG. After the actuator 106 oscillates, a digital signal that is High for a predetermined period is generated, and when the back electromotive force waveform crosses the reference voltage, it is determined that there is no ink. If the back electromotive force waveform does not cross the reference voltage, it is determined that ink is present.

  FIG. 4C shows an example in which the time from the 4th count to the 8th count of the pulse waveform shown in FIG. 4A is measured using a predetermined clock pulse. In this figure, clock pulses appear for 5 counts from the 4th count to the 8th count (actually, clock pulses for 100 count to 200 counts appear. In order to do this, we will explain with less clock pulses) Since the clock pulse is a pulse having a certain period, the time can be measured by counting the number of clock pulses. The resonance frequency can be obtained by measuring the time from the 4th count to the 8th count. The clock pulse preferably has a period shorter than the period of the back electromotive force waveform. For example, if the resonance frequency is about 400 kHz, the clock pulse is preferably a clock pulse having a high frequency such as 16 MHz.

  FIG. 5 shows a configuration of a recording apparatus control unit 2000 for detecting the consumption state of the liquid in the liquid container 1 by the actuator 106 detecting a change in acoustic impedance and controlling the ink jet recording apparatus based on the detected result. Indicates.

  The recording apparatus control unit 2000 applies a voltage for driving the actuator 106 to the actuator 106 mounted on the liquid container 1, and as a result, detects a liquid consumption state from a change in acoustic impedance detected by the actuator 106. A detection unit 1200; and a control circuit unit 1500 that controls the recording apparatus based on the liquid presence / absence detection result output by the liquid consumption state detection unit 1200.

  The control circuit unit 1500 controls the recording apparatus operation control unit 1402 based on the liquid presence / absence detection result output from the liquid consumption state detection unit 1200, and controls the operation of the recording apparatus based on an instruction from the control unit 1400. And a recording apparatus operation control unit 1402 for controlling. The control circuit unit 1500 includes a presentation processing unit 1404 whose operation is controlled by the recording device operation control unit 1402, a printing operation control unit 1406, an ink supplement processing unit 1408, a cartridge replacement processing unit 1410, a print data storage processing unit 1412, and A print data storage unit 1414 is further provided.

  The recording apparatus control unit 2000 may be provided inside the ink jet recording apparatus, but some functions of the recording apparatus control unit 2000 may be provided outside. For example, the function of the control circuit unit 1500 may be given to an external device such as a computer connected to the recording device. Furthermore, some functions of the recording apparatus control unit 2000 may be stored and supplied as a program in a recording medium. When a part of the functions of the recording device control unit 2000 is improved at a later date by supplying a part of the functions of the recording device control unit 2000 to a computer connected to the recording device as a program stored in a recording medium, it is easy. A program for executing the latest function can be stored in a storage medium of a computer, and the operation of the recording apparatus can be controlled using the latest function at all times.

  Also, some functions of the recording apparatus control unit 2000 may be transmitted as a program from an information processing apparatus such as a server to a terminal such as a computer connected to the recording apparatus via an electric communication line. In this case, the latest function can be easily obtained from the server via the telecommunication line and stored in the storage device of the computer, whereby the recording device can always execute the latest function.

  The liquid consumption state detection unit 1200 drives the actuator 106 to detect the presence or absence of liquid in the liquid container 1 from the change in acoustic impedance. For example, the liquid consumption state detection unit 1200 includes a measurement circuit unit 800 that measures a counter electromotive force generated by the residual vibration of the actuator 106, for example, a voltage value, and a back electromotive force measured by the measurement circuit unit 800. And a detection circuit unit 1100 that outputs a signal indicating the presence or absence of the liquid.

  The measurement circuit unit 800 includes a drive voltage generation unit 850 that is disposed in the vicinity of the actuator 106 in the liquid container 1 and generates a drive voltage for driving the actuator 106. The actuator 106 attached to the liquid container 1 is driven and oscillated by the drive voltage generated by the drive voltage generator 850. The actuator 106 continues to vibrate after the drive oscillation. Due to this residual vibration, the actuator 106 itself generates a counter electromotive force. The measurement circuit unit 800 converts the analog signal of the back electromotive force waveform generated by the actuator 106 into a digital signal having the same frequency and outputs the digital signal to the digital circuit unit 900.

  Since the measurement circuit unit 800 is disposed in the vicinity of the actuator 106, the distance and time for transmitting the back electromotive force signal (analog signal) generated by the actuator 106 to the measurement circuit unit 800 is short. That is, the distance and time at which the back electromotive force signal, which is an analog signal, receives noise is short. Further, the digital signal after being converted by the measurement circuit unit 800 is significantly more resistant to noise than the analog signal. As described above, the influence of noise on the back electromotive force signal can be significantly reduced. Furthermore, the degree of freedom of wiring after the measurement circuit unit 800 can be increased.

  The detection circuit unit 1100 determines the presence / absence of liquid based on the digital circuit unit 900 that measures the time spent oscillating a predetermined number of pulses of the digital signal output from the measurement circuit unit 800 and the time counted by the digital circuit unit 900. And a liquid presence / absence determination unit 1000.

  In this embodiment, as shown in FIGS. 4 (A) and 4 (B), the digital circuit unit 900 is high in the 4th to 8th counts in the pulse waveform output by the measurement circuit unit 800. Output a signal. Further, as shown in FIG. 4 (C), the digital circuit section 900 has a predetermined clock pulse (from the cycle of the back electromotive force waveform) in the period from the fourth count to the eighth count in the digital signal. Count the number of pulses (with a short period). By counting the number of clock pulses having a certain period, the time from the 4th count to the 8th count can be measured. For example, in FIG. 4C, there are 5 counts of clock pulses, and the time can be calculated by multiplying 5 counts with the cycle of the clock pulses.

  Here, in order to simplify the description, a low-frequency clock pulse is described as an example, but a clock pulse having a high frequency such as 16 MHz is actually used. The liquid presence / absence determination unit 1000 determines the presence / absence of liquid in the liquid container 1 based on the count value output by the digital circuit unit 900 and outputs the determination result to the control circuit unit 1500.

  Note that high frequency clock pulses can affect the back electromotive force signal, which is an analog signal (the signal may be “ridden” as noise). Therefore, it is preferable that the high frequency line portion including the digital circuit unit 900 from the high frequency clock pulse source is as far as possible from the analog line portion from the actuator 106 to the measurement circuit unit 800. For example, when the latter analog line portion is provided in the liquid container 1, the former high-frequency line portion can be provided in a recording apparatus main body portion or a carriage portion outside the liquid container 1.

  When the liquid consumption state detection unit 1200 outputs a determination result indicating no liquid, the control unit 1400 controls the printing apparatus operation control unit 1402 to perform a predetermined low ink amount handling process. The low ink amount handling process is a process for prohibiting or suppressing the operation of the recording apparatus such as improper printing in consideration of the fact that the ink is low. The recording apparatus operation control unit 1402 performs operations of the presentation processing unit 1404, the printing operation control unit 1406, the ink replenishment processing unit 1408, the cartridge replacement processing unit 1410, or the print data storage processing unit 1412 based on an instruction from the control unit 1400. To control the low ink amount.

  The presentation processing unit 1404 presents information corresponding to the presence or absence of liquid in the liquid container 1 detected by the actuator 106. Information presentation includes display on the display 1416 and notification by the speaker 1418. The display 1416 is, for example, a display panel of a recording apparatus or a computer screen connected to the recording apparatus. Alternatively, when the presentation processing unit 1404 is connected to the speaker 1418 and the actuator 106 detects that there is no liquid, a notification sound is output from the speaker 1418. The speaker 1418 may be a speaker of a recording device or a speaker of an external device such as a computer connected to the recording device. It is also preferable to use an audio signal as the notification sound, and a synthesized voice indicating the ink consumption state may be generated by voice synthesis processing.

The printing operation control unit 1406 controls the printing operation unit 1420 to stop the printing operation of the recording apparatus. By stopping the printing operation, the printing operation after the ink runs out is avoided. Further, as another example of the low ink amount handling process, the printing operation control unit 1406 may prohibit a certain printing process from moving to the next printing process.
By prohibiting such printing processing, it is possible to avoid stopping printing during one printing processing, for example, printing a series of sentences. In addition, as an example of prohibition of the printing process, it is also preferable to prohibit the printing process after the end of the page break in order to prevent the printing process from stopping during the printing of one page.

  The ink replenishment processing unit 1408 controls the ink replenishing device 1422 to automatically replenish ink into the ink cartridge. Printing can be continued by replenishing the ink.

  The cartridge replacement processing unit 1410 controls the cartridge replacement device 1424 to automatically replace the ink cartridge. With such handling processing, the printing operation can be continued without disturbing the user's hand.

  The print data storage processing unit 1412 stores the print data before completion of printing in the print data storage unit 1414 as the low ink amount handling process. This print data is print data sent to the recording apparatus after the ink end is detected. By storing the print data, it is possible to avoid the loss of print data before printing.

  All of the components 1404 to 1412 need not be provided in the printing apparatus control unit 2000. Further, it is not necessary for all the components 1404 to 1412 to perform the low ink amount handling process, and it is sufficient that at least one low ink quantity handling process is performed. For example, if the ink replenishment processing unit 1408 or the cartridge replacement processing unit 1410 performs processing, the printing operation control unit 1406 may not perform the printing operation stop processing.

  In addition, the structure which performs the low ink amount corresponding | compatible process except the example illustrated above, ie, the structure which avoids the inappropriate operation | movement by ink shortage, may be provided. Further, it is preferable that the low ink amount handling process is executed after the actuator 106 detects “no liquid” at the mounting position and then performs printing for a “predetermined margin”. The “predetermined margin” is set to an appropriate value smaller than the printing amount until all the ink is consumed after the actuator 106 detects “no liquid”.

  FIG. 6 is a block diagram illustrating a recording apparatus control unit 2002 according to another embodiment. In the present embodiment, three actuators 106A, 106B, and 106C are attached to the liquid container 1. The three actuators 106A, 106B, and 106C are installed at different positions along the liquid level lowering direction due to liquid consumption.

  In the example shown in FIG. 6, a measurement circuit unit 800A having drive voltage generation units 850A, 850B, and 850C that respectively supply voltages for driving the actuators to the three actuators 106A, 106B, and 106C attached to the liquid container 1. , 800B and 800C are disposed in the vicinity of each. The digital circuit unit 902 in the detection circuit unit 1102 receives the digital signals generated by the measurement circuit units 800A, 800B, and 800C from the back electromotive force signals generated by the actuators 106A, 106B, and 106C, and receives the respective digital signals ( The number of pulses within a predetermined time (corresponding to the back electromotive force signal) is counted. Further, the liquid presence / absence determination unit 1002 determines the presence / absence of liquid in the liquid container 1 based on the count value of each back electromotive force signal output from the digital circuit unit 902.

  In this embodiment, since the plurality of actuators 106A to 106C are mounted at different positions in the liquid level lowering direction, it is possible to detect in stages the liquid consumption state at each actuator mounting position. Since the configuration other than the liquid consumption state detection unit 1202 of the recording device control unit 2002 is the same as the configuration of the recording device control unit 2000 of FIG.

  The output signal of each actuator varies depending on whether the liquid level is higher than the mounting position level of each actuator. For example, if the frequency or amplitude of the detected back electromotive force changes greatly, the detection signal changes accordingly. The liquid consumption state detection unit 1202 can determine whether or not the liquid level of the liquid has passed the mounting position level of each actuator 106A, 106B, and 106C based on each detection signal. The detection process is periodically performed, for example, at a predetermined timing.

  Here, the state in which the liquid level is lower than the mounting position of the actuator is referred to as “no liquid state”, and the state in which the liquid level is higher than the actuator is referred to as “liquid present state”. When the liquid level passes through the actuator, the detection result changes from the “liquid present state” to the “no liquid state”. In the present embodiment, detection of passing through the liquid level indicates such a change in detection result.

  As a feature of the present embodiment, the control unit 1400 switches the actuator used for impedance detection along the liquid level lowering direction according to the progress of liquid consumption. More specifically, just after the mounting of the liquid container 1, that is, in the liquid full state, only the actuator 106A is used. When the liquid is consumed and the liquid level passes through the actuator 106A, the actuator 106A detects the absence of liquid. In response to this, the control unit 1400 switches the liquid detection position to the middle stage, that is, the consumption of the liquid is detected using only the actuator 106B. Similarly, when the actuator 106B detects the absence of liquid, the detection position is switched to the lowermost actuator 106C.

  According to the present embodiment, the detection positions are sequentially switched downward, so that all the actuators do not always have to operate. That is, the frequency of operation of the actuator is low. Therefore, the data processing amount in the control unit 1400 can be suppressed. As a result, the detection operation does not reduce the throughput of the printing operation.

  In the present embodiment, the number of actuators is three. However, the number of actuators is not limited as long as it is three or more. Further, the distance between the actuators may not be constant. For example, it is preferable to narrow the actuator interval as the liquid level becomes lower. Such a modification can be similarly applied to other embodiments described below.

FIG. 7 shows an embodiment in which the recording apparatus control unit 2000 shown in FIG. 5 is modified. The liquid container 1 in FIG. 7 is mounted on a carriage so as to communicate with a head unit 1300 for discharging and printing the liquid in the liquid container 1 onto a recording medium such as recording paper.
The head unit 1300 is driven by a head driving unit 1440. 7 includes a cleaning unit 1436 that sucks liquid from the head unit 1300 to clean the nozzles of the head unit 1300. When the cleaning drive unit 1432 drives the pump 1434, the cleaning unit 1436 sucks liquid from the head unit 1300.

  7 includes a liquid discharge counter (dot) that counts the number of ink droplets ejected by the head unit 1300 in addition to the elements of the recording device control unit 2000 shown in FIG. Counter) 1450, a liquid consumption calculation unit 1452 that calculates the ink consumption based on the number of ink droplets counted by the liquid ejection counter 1450, and a cleaning drive based on the ink consumption state detected by the liquid consumption state detection unit 1210. And a cleaning control unit 1442 for controlling the unit 1432. The detection circuit unit 1104 also includes a liquid consumption state correction unit 1010 that corrects the number of ink droplets discharged from the head unit 1300 counted by the liquid discharge counter 1450 based on the ink consumption state detected using the actuator 106. .

  Next, the operation for the newly added elements in FIG. 7 will be described. The liquid ejection counter 1450 counts the number of ink droplets ejected from the head unit 1300 during printing, and outputs the counted number to the liquid consumption calculation unit 1452. The liquid consumption amount calculation unit 1452 calculates the amount of ink ejected from the head unit based on the count value of the liquid ejection counter 1450.

  In addition, by applying a drive signal unrelated to printing to the print head to cause ink droplets to be ejected idle, uneven meniscus in the vicinity of the nozzle opening of the head portion 1300 can be recovered, or ink clogging at the nozzle opening can be prevented. Inhibiting (flushing operation) also consumes ink. Therefore, the liquid discharge counter 1450 also counts the number of ink droplets discharged by the flushing operation, and outputs it to the liquid consumption calculation unit 1452.

  The liquid consumption calculation unit 1452 calculates the ink consumption from the number of ink ejections from the head unit 1300 in the printing operation and the flushing operation, and outputs the calculated ink consumption to the liquid consumption state correction unit 1010. The ink amount calculated by the liquid consumption amount calculation unit 1452 is displayed on the display 1416 of the presentation processing unit 1404.

  Further, when the head unit 1300 is cleaned by the cleaning unit 1436 (cleaning operation), the ink in the liquid container 1 is consumed by sucking the ink in the head unit 1300. Accordingly, the liquid consumption calculation unit 1452 multiplies the time (for example, the time when the pump 1434 is energized) by the cleaning drive unit 1432 via the cleaning control unit 1442 and the ink absorption amount per hour of the pump 1434. Thus, the amount of ink consumed for cleaning is calculated.

  Accordingly, the liquid consumption amount calculation unit 1452 calculates the amount of ink consumed by the liquid ejection counter 1450 and the cleaning control unit 1442. The liquid consumption state correction unit 1010 corrects the calculated value of the liquid consumption amount calculation unit 1452 based on the determination result of the liquid presence / absence determination unit 1000.

  The reason why the two outputs of the liquid presence / absence determining unit 1000 and the liquid consumption calculating unit 1452 are used for detecting the ink consumption state will be described below.

  The output of the liquid presence / absence determination unit 1000 is information obtained by actually measuring the liquid level by the actuator 106. On the other hand, the output of the liquid consumption calculation unit 1452 is an estimated ink consumption calculated from the number of ink droplets counted by the liquid ejection counter 1450 and the driving time of the pump.

  This calculated value depends on the printing mode and usage environment set by the user, for example, when the room temperature is extremely high or low, or when the elapsed time after opening the ink cartridge is long, the pressure in the ink cartridge or the ink Errors may occur due to changes in viscosity.

  Therefore, the liquid consumption state correction unit 1010 corrects the ink consumption calculated by the liquid consumption calculation unit 1452 based on the ink presence / absence determination result output from the liquid presence / absence determination unit 1000. Further, the liquid consumption state correction unit 1010 corrects the parameters of the calculation formula used by the liquid consumption amount calculation unit 1452 to calculate the ink consumption amount based on the ink presence / absence determination result output from the liquid presence / absence determination unit 1000. To do. By correcting the parameters of the calculation formula in this way, the calculation formula can be adapted to the environment in which the ink cartridge is used. As a result, the value obtained by the calculation formula is approximated by the actually used value.

  When the actuator 106 detects “no ink” at the mounting position, the printing operation control unit 1406, the ink supplement processing unit 1408, the cartridge replacement processing unit 1410, the print data storage processing unit 1412, and the like controlled by the recording device operation control unit 1402 The cleaning control unit 1442 performs a predetermined low ink amount handling process.

  The printing operation control unit 1406 controls the head driving unit 1440 to stop ink ejection from the head unit 1300 or reduce the ink ejection amount. Thereby, the printing operation after the ink runs out is avoided.

  As the low ink handling process, the cleaning control unit 1442 prohibits the cleaning operation of the head unit 1300 by the cleaning unit 1436, reduces the number of times of cleaning, weakens the suction force of the pump 1434, and reduces the ink suction amount. Decrease. When cleaning the head unit 1300, a relatively large amount of ink is sucked from the head unit 1300. Therefore, by prohibiting the cleaning operation when the ink becomes low, it is possible to prevent the remaining ink from being sucked from the head unit 1300 for cleaning, and it is possible to avoid a situation where the ink is insufficient for cleaning. Alternatively, as described above, the number of cleanings may be reduced, or the suction force of the pump 1434 may be weakened. The control unit 1400 selects what kind of low ink processing the printing operation control unit 1406 and the cleaning control unit 1442 execute based on the remaining amount of ink in the liquid container 1.

  FIG. 8 shows an embodiment in which the recording device control unit 2004 shown in FIG. 7 is modified. In this embodiment, the semiconductor storage means 7 is mounted on the liquid container 1, and the recording device control unit 2006 has an information storage control circuit unit 1444. The rest of the configuration is the same as that of the recording apparatus control unit 2004 shown in FIG. Therefore, description of elements not related to the semiconductor storage unit 7 and the information storage control unit 1444 is omitted.

  The liquid container 1 according to the present embodiment includes an actuator 106 and semiconductor storage means 7. The semiconductor memory means 7 is a rewritable memory such as an EEPROM, for example. The control circuit unit 1506 includes an information storage control circuit unit 1444.

  The liquid consumption state detection unit 1210 controls the actuator 106 to detect the consumption state of the liquid in the liquid container 1, and outputs consumption related information related to the detection of the liquid consumption state using the actuator 106 to the control circuit unit 1506. To do.

  The control unit 1400 writes consumption related information in the semiconductor storage means 7 via the information storage control circuit unit 1444. Further, the information storage control circuit unit 1444 reads consumption-related information from the semiconductor storage unit 7 and outputs it to the control unit 1400.

  Next, the semiconductor memory means 7 will be described in detail. The semiconductor storage means 7 stores consumption related information related to detection of the liquid consumption state using the actuator 106. The consumption related information includes information on the consumption state of the detected liquid. The information storage control circuit unit 1444 writes consumption state information obtained by using the actuator 106 in the semiconductor storage means 7. The consumption state information is read out and used in the recording device control unit 2006.

  Storing the consumption state information in the semiconductor storage means 7 is advantageous particularly when the liquid container 1 is detached. For example, it is assumed that the liquid container 1 is removed from the ink jet recording apparatus while the liquid is consumed halfway. At this time, the semiconductor storage means 7 storing the liquid consumption state is always present together with the liquid container 1. The liquid container 1 is mounted again on the same ink jet recording apparatus, or is mounted on another ink jet recording apparatus. At this time, the liquid consumption state is read from the semiconductor storage means 7, and the recording apparatus control unit 2006 operates based on the liquid consumption state. For example, even when the liquid is empty or the liquid container 1 with a small amount of liquid is attached, the fact is notified to the user. Thus, even when the liquid container 1 is detached, the previous consumption state information of the liquid container 1 can be reliably used.

  The semiconductor storage unit 7 may further store the liquid consumption state calculated by the liquid consumption amount calculation unit 1452 based on the number of ink droplets counted by the liquid ejection counter 1450. The actuator 106 can reliably detect the passage of the ink liquid level at the mounting position of the actuator 106, but it is difficult to detect the ink consumption state before and after the liquid surface passage. Therefore, it is preferable to estimate the ink consumption state before and after passing through the liquid level from the liquid consumption state calculated by the liquid consumption amount calculation unit 1452 and store the estimated value in the semiconductor storage unit 7.

  The consumption related information includes detection characteristic information to be detected in accordance with the liquid consumption state. In the present embodiment, pre-consumption detection characteristic information and post-consumption detection characteristic information are stored as detection characteristic information. The pre-consumption detection characteristic information indicates a detection characteristic before ink consumption is started, that is, a detection characteristic in an ink full state. The post-consumption detection characteristic information is a detection characteristic that is to be detected when the ink is consumed up to a predetermined detection target, specifically, a detection characteristic when the ink level is below the mounting position level of the actuator 106. Show.

  The information storage control circuit unit 1444 reads the detection characteristic information from the semiconductor storage unit 7, and the liquid consumption state detection unit 1210 detects the liquid consumption state using the actuator 106 based on the detection characteristic information. When a detection signal corresponding to the pre-consumption detection characteristic is obtained, it is considered that ink consumption has not progressed yet and the remaining amount of ink is large. At least, it can be clearly seen that the ink level is above the actuator 106. On the other hand, when a detection signal corresponding to the detection characteristic after consumption is obtained, it is understood that the ink level is lower than the actuator 106 because the ink consumption progresses and the remaining amount is low.

  One advantage of storing the detection characteristic information in the semiconductor storage means 7 will be described.

The detection characteristic information is determined by various factors such as the shape of the liquid container 1, the specifications of the actuator 106, the ink specifications, and the like. Accordingly, when a design change such as improvement is made, the detection characteristics may also change. If the liquid consumption state detection unit 1210 always uses the same detection characteristic information, it is difficult to cope with such a change in detection characteristic.
On the other hand, in the present embodiment, the detection characteristic information is stored and used in the semiconductor storage means 7. Therefore, it is possible to easily cope with changes in detection characteristics. For example, even when a liquid container 1 having a new specification is provided, the recording device control unit 2006 can easily use the detection characteristic information of the liquid container 1.

  Even if the specifications of the liquid container 1 are the same, the detection characteristics may differ due to manufacturing variations. For example, the detection characteristics may vary depending on the shape and thickness of the liquid container 1. Therefore, more preferably, the detection characteristic information for each individual liquid container 1 is measured and stored in the semiconductor storage means 7. In the present embodiment, since each liquid container 1 has the semiconductor storage means 7, the detection characteristic information unique to the semiconductor storage means 7 can be stored. Thereby, the influence on the detection of manufacturing variation can be reduced, and the detection accuracy can be improved. As described above, this embodiment is advantageous because it can cope with the difference in detection characteristics of the individual liquid containers 1.

  FIG. 9 is a flowchart showing an operation procedure of the recording apparatus control unit 2006 shown in FIG.

  First, it is determined whether or not an ink cartridge is mounted (S10). That is, it is detected that a new ink cartridge or an ink cartridge that has been used halfway is installed. For this process, a switch or the like (not shown) provided in the ink jet recording apparatus is used.

  When the ink cartridge is mounted, consumption-related information including detection characteristic information and the like is read from the semiconductor storage unit 7 (S12). The presentation processing unit 1404, the printing operation control unit 1406, the ink replenishment processing unit 1408, the cartridge replacement processing unit 1410, the print data storage processing unit 1412, and the cleaning control unit 1442 of the recording device control unit 2008 display the read consumption related information. Use. For example, when it is found from the consumption-related information that has been read that the remaining amount of liquid in the liquid container 1 is small, the display 1416 displays that the remaining amount of liquid is low, or stops the operation of the head unit 1300.

The liquid consumption state detection unit 1210 detects the liquid consumption state using the actuator 106 based on the read detection characteristic information (S14). Based on the detected liquid consumption state, the presence or absence of the liquid in the liquid container 1 is determined (S16). If “no liquid” is detected, the liquid no-response process (S18) is executed.
In the liquid absence handling step (S18), the print data storage processing unit 1412 stores the print data (S24), the printing operation control unit 1406 stops the printing operation (S26), and the presentation processing unit 1404 supplies no liquid. Is included (S28).

  In this case, the ink is replenished to the ink jet recording apparatus by the user replacing the ink cartridge as will be described later according to the instruction of the no liquid display step (S28).

Alternatively, as the no-liquid handling step (S18), the ink cartridge may be automatically replaced (S20) by the cartridge replacement processing unit 1410, or ink may be automatically replenished (S22) by the ink replenishment processing unit 1408. Also good. In this case, the ink is automatically supplied to the ink jet recording apparatus, and the user does not need to replace the ink cartridge. In this case, the process returns to the liquid consumption information reading step (S12) without passing through a cartridge replacement determination step (S32) described later.
In the case where the ink replenishing step (S22) is performed, after the ink has been replenished, information on how much ink has been replenished to the recording apparatus is stored in the semiconductor storage means 7 (S34).

  After the print data storage step (S24), the printing operation stop step (S26) and the no-liquid display step (S28) are executed as the no-liquid handling means (S18), the detected liquid consumption state is stored in the semiconductor storage means 7. Stored (S30). The fact that there is no ink in the ink cartridge is transmitted to the user by the no-liquid display step (S28), so the user replaces the ink cartridge according to the instruction of the no-liquid display step (S28). In this case (S32, Y), the process returns to the liquid consumption state detection step (S14). On the other hand, when the user does not replace the ink cartridge, a display for prompting the user to replace the ink cartridge is presented on the display or the speaker, and the process is terminated.

  FIG. 10 is a diagram illustrating a circuit configuration of the measurement circuit unit 800. The measurement circuit unit 800 includes a drive voltage generation unit 850, a reference potential generation unit 816, a high-pass filter 824, an amplification unit 860, and a comparator 836. The driving voltage generation unit 850 includes two bipolar transistors, an NPN transistor 810 and a PNP transistor 812, whose bases B and emitters E are complementarily connected in parallel. The NPN transistor 810 and the PNP transistor 812 are transistors for driving the actuator 106. The actuator 106 has one terminal connected to the emitters E of the NPN transistor 810 and the PNP transistor 812 connected to each other, and the other terminal connected to the ground GND. The other terminal of the actuator 106 may be connected to a power supply Vcc (5 V).

  When the trigger signal input from the terminal 840 to the drive voltage generation unit 850 changes from Low to High, the bases B of the NPN transistor 810 and the PNP transistor 812 connected to each other rise, and the NPN transistor 810 and the PNP transistor 812 are connected. Amplifies the current of the input trigger signal and supplies it to the actuator 106. In the case of FIG. 10, the voltage between the emitter E and the collector C of the PNP transistor 812 is applied to the actuator 106. For this reason, the actuator 106 is rapidly charged and oscillates. Further, the actuator 106 generates a counter electromotive force due to vibration remaining after oscillation. The back electromotive force generated by the residual vibration of the actuator 106 is output to the amplifying unit 860 via the high pass filter 824.

  A PN junction is formed between the base B and the emitter E of the NPN transistor 810 (the same applies to the PNP transistor 812). When the potential difference between the base B and the emitter E is 0.6 V or less, almost no current flows to the emitter E side. When 0.6V is exceeded, a greatly amplified current flows through the emitter E. That is, the NPN transistor 810 and the PNP transistor 812 each have a dead band or a bias voltage of 0.6V, and the NPN transistor 810 and the PNP transistor 812 have a bias voltage of about 1.2V in total. If the terminal potential including the back electromotive force of the actuator 106 is within the dead band range, the transistor operates and no current flows into the emitter E, and the residual vibration of the actuator 106 is suppressed for the operation of the transistor. There is nothing. Without the dead band, the voltage of the actuator 106 is controlled by the transistor to be a constant value, and the back electromotive force cannot be examined.

In FIG. 10, an NPN transistor 810 and a PNP transistor 812 are used as bipolar transistors, but a field effect transistor may be used instead of the bipolar transistor. When a field effect transistor is used, the N type field effect transistor is arranged at a position where the NPN type transistor in FIG. 10 is arranged. The gate of the N-type field effect transistor is arranged at the position of the base B of the NPN-type transistor 810 and the source is arranged at the position of the emitter E.
Further, a P-type field effect transistor is disposed at a position where the PNP transistor 812 is disposed. The gate of the P-type field effect transistor is disposed at the position of the base B of the PNP transistor 812 and the source is disposed at the position of the emitter E. Furthermore, the gates and sources of the P-type field effect transistor and the N-type field effect transistor are connected. The actuator 106 is preferably connected to the sources of a P-type field effect transistor and an N-type field effect transistor whose one terminals are connected to each other, and the other terminal is connected to the power supply Vcc or the ground GND.

  The high pass filter 824 includes a capacitor 826 and a resistor 828. The output of the drive voltage generation unit 850 is output to the amplification unit 860 through such a high pass filter 824. The high pass filter 824 outputs a high frequency component of the output of the actuator 106 to the amplification unit 860, while removing a low frequency component. Further, the high-pass filter 824 has a role of adjusting the output of the amplifying unit 860 so that it falls within the range of 0 to 5 V with the reference potential as the center.

  The reference potential generation unit 816 includes resistors 818 and 820 connected in series, and a capacitor 822 connected in parallel to the resistor 820. As a result, the reference potential generation unit 816 generates a stable DC potential of about 2 to 3 V as the reference potential and supplies it to the high-pass filter 824, the amplification unit 860, and the comparator 836. For this reason, the voltage of the signal waveform output from the high-pass filter 824 and the amplification unit 860 oscillates around the reference potential.

  The amplifier 860 includes an operational amplifier 834 and resistors 830 and 832. The operational amplifier 834 and the resistors 830 and 832 are configured as a non-inverting amplifier circuit that amplifies and outputs an input signal without inverting it. The back electromotive force signal output from the drive voltage generation unit 850 is input to the + terminal of the operational amplifier 834 via the high pass filter 824. The negative terminal of the operational amplifier 834 is connected to the output terminal through the negative feedback resistor 830, and is connected to the reference potential through the resistor 832. As a result, the weak counter electromotive force signal output from the actuator 106 is amplified around the reference potential and output to the comparator 836. The waveform of the back electromotive force signal thus amplified can be represented as the analog waveform shown in FIG.

  The comparator 836 receives the voltage of the back electromotive force signal output from the amplifying unit 860 and the reference potential generated by the reference potential generating unit 816, and when the voltage of the back electromotive force signal is equal to or higher than the reference potential, A low signal is output when the voltage of the back electromotive force signal is equal to or lower than the reference potential. Thereby, a counter electromotive force signal having a digital waveform is generated. That is, while the output of the operational amplifier 834 oscillates around the reference potential, the voltage at the negative terminal of the comparator 836 is equal to the reference potential, so the comparator 836 compares the voltage of the back electromotive force signal with reference to the reference potential. To output a counter electromotive force signal having a digital waveform. The comparator 836 outputs the generated digital waveform back electromotive force signal to the terminal 844.

  As described above, the drive voltage signal is supplied to the piezoelectric element by the input of the trigger signal from the terminal 840. This trigger signal can be input by the controller 840c. The control device 840c can be provided in various liquid consuming devices such as an ink jet recording device on which a liquid container is mounted.

  Here, another example of the circuit configuration of the measurement circuit unit 800 will be described with reference to FIG.

  In this case, the reference potential generation unit 816 includes resistors 817, 818, and 820 connected in series, and a capacitor 822 connected in parallel to the resistor 820. In this case, both the resistor 817 and the resistor 820 are about 5 kΩ, and the resistor 818 is about 500Ω. Accordingly, the reference potential generation unit 816 generates two stable DC potentials of about 2 to 3 V as the reference potentials A and B, and supplies them to the high-pass filter 824, the amplification unit 860, and the comparator 836, respectively. For this reason, the voltage of the signal waveform output from the high pass filter 824 and the amplifying unit 860 oscillates around the reference potential B.

  The high-pass filter 824 plays a role of adjusting the output of the amplifying unit 860 so as to be within a range of 0 to 5 V (Vcc) with a reference potential B (described later) as a center.

  The amplifier 860 includes an operational amplifier 834 and resistors 830 and 832. The operational amplifier 834 and the resistors 830 and 832 are configured as a non-inverting amplifier circuit that amplifies and outputs an input signal without inverting it. The back electromotive force signal output from the drive voltage generation unit 850 is input to the + terminal of the operational amplifier 834 via the high pass filter 824. The negative terminal of the operational amplifier 834 is connected to the output terminal through the negative feedback resistor 830, and is connected to the reference potential B through the resistor 832. As a result, the weak counter electromotive force signal output from the actuator 106 is amplified around the reference potential B and output to the comparator 836. The waveform of the back electromotive force signal thus amplified can be represented as the analog waveform shown in FIG.

  The comparator 836 receives the voltage of the back electromotive force signal output from the amplifying unit 860 and the reference potential A generated by the reference potential generating unit 816, and when the voltage of the back electromotive force signal is equal to or higher than the reference potential A. A high signal is output when the voltage of the back electromotive force signal is equal to or lower than the reference potential A. Thereby, a counter electromotive force signal having a digital waveform is generated. That is, while the output of the operational amplifier 834 oscillates around the reference potential B, the voltage at the negative terminal of the comparator 836 is equal to the reference potential A. Therefore, the comparator 836 uses the voltage of the back electromotive force signal with reference to the reference potential A. Are compared, and a counter electromotive force signal having a digital waveform is output. The comparator 836 outputs the generated digital waveform back electromotive force signal to the terminal 844.

  The level relationship between the reference voltage A and the reference voltage B may be reversed.

  In FIG. 11, other circuit configurations are substantially the same as those of the measurement circuit unit 800 shown in FIG.

  In the measurement circuit unit 800 shown in FIG. 11, when there is no back electromotive force, the output of the operational amplifier 834 becomes the reference potential B. Therefore, the output signal of the comparator 836 is always low and should not change. By utilizing this fact, it is possible to determine the presence or absence of the influence of noise in the measurement circuit unit 800.

  For example, the measurement circuit unit 800 may include a noise influence determination unit 880 as illustrated in FIG. The noise influence determination unit 880 determines the influence of noise on the back electromotive force signal, for example, according to the flow shown in FIG.

  In this case, the noise influence determination unit 880 is equal to or longer than the time required for normal resonance frequency (frequency of the back electromotive force signal) measurement (details will be described later) before the drive voltage signal is applied to the piezoelectric element. , The output from the comparator 836 is observed (STEP 1).

  Then, it is determined whether or not the output of the comparator 836 has changed during the specified time (STEP 2).

  When there is no change in output, it is determined that the influence of noise is small, a drive voltage signal is given to the piezoelectric element, and the resonance frequency is measured by the detection circuit unit 1100 (detailed later with reference to FIGS. 13 and 14). Etc. are implemented (STEP 3).

  On the other hand, if there is a change in the output, it is determined that the influence of noise is large, and information indicating that the measurement of the resonance frequency by the detection circuit unit 1100 cannot be accurately performed in the current state is output on a display screen (not shown). (STEP 4).

  As described above, according to the flowchart shown in FIG. 12, it is possible to avoid measuring an erroneous resonance frequency due to the influence of noise.

  Further, instead of configuring the noise effect determination unit 880 as a separate circuit, the noise effect determination unit may be configured using the digital circuit unit 900.

  FIG. 13 shows a circuit configuration of the detection circuit unit 1100 of FIG. The detection circuit unit 1100 includes a digital circuit unit 900 and a liquid presence / absence determination unit 1000. The digital circuit unit 900 includes flip-flops 910 and 918, counters 912 and 920, and NAND gates 914 and 916. When the counter 920 counts up to the maximum value (1111, 1111), it does not become (0000, 0000) even if the next clock pulse is input, and maintains the maximum value.

  When the trigger signal is input from the terminal 842 to the clock input pin CLK of the flip-flop 910, the flip-flop 910 measures the number of pulses of the counter electromotive force signal output from the measurement circuit unit 800 to the counter 912. A signal for controlling the counter 912 to start is output. Further, when the counter 912 counts eight counter electromotive force signal pulses, the flip-flop 910 is cleared via the NAND gate 916. Therefore, the flip-flop 910 supplies a signal that is High during the period from the input of the trigger signal to the eighth pulse of the counter electromotive force signal to the count enable terminal ENP of the counter 912.

  The counter 912 counts the clock only when the signal input to the counter enable terminal ENP is High. The counter 912 starts counting the number of pulses of the back electromotive force signal after the trigger signal is input to the flip-flop 910, and the signal input to the count enable terminal ENP becomes Low when the number of pulses reaches eight. Finish counting the number of pulses. The counter 912 outputs a signal in which the fourth to eighth pulses are High from the output pin QC to the input pin D of the flip-flop 918.

  The flip-flop 918 receives from the input pin D the signal from the fourth pulse to the eighth pulse output from the counter 912 from the input pin D, and receives the clock of 16 MHz frequency input from the terminal 846 from the clock input pin CLK. Then, the signal input from the input pin D is output in synchronization with the clock.

  In the circuit of FIG. 13, the number of 16 MHz clock pulses existing between the 4th pulse and the 8th pulse of the back electromotive force waveform is counted, but a counting circuit using the output of the counter 912 is added and combined. Thus, not only the time up to the eighth count but also the arbitrary count can be counted. That is, the time within different count intervals can be detected.

  In FIG. 13, the signal at the terminal 846 which is a clock signal is a high-frequency signal, which may give noise to the digital circuit portion 800 and cause malfunction. Therefore, when the clock signal is arranged away from the required digital part or the circuit is made into an IC, it is desirable to make the analog part and the digital part different ICs. At that time, the measurement circuit unit 800 is placed near the ink cartridge, and the detection circuit unit 1100 is disposed on the main board or the like. In this case, since the signal at the terminal 844 is a digital signal and is resistant to noise, there is no problem even if a long distance is routed. Alternatively, the flip-flop 910 and the counter 912 may also be disposed near the cartridge, and the outputs QB and QC of the counter 912 may be routed. Further, if one of the inputs of the NAND gate 914 is not the output of the flip-flop 918 but a signal obtained by inverting the QC of the counter 912, only the output QC of the counter 912 needs to be routed.

FIG. 14 shows a detailed circuit configuration of the liquid presence / absence determining unit 1000 shown in FIG.
The liquid presence / absence determination unit 1000 determines the presence / absence of liquid in the liquid container 1 based on the count value of the number of clock pulses of 16 MHz appearing between the fourth pulse and the eighth pulse of the counter electromotive force signal output from the counter 920. to decide. As shown in FIG. 14, the liquid presence / absence determination unit 1000 includes an upper limit register 1011, a lower limit register 1012, comparison units 1014 and 1016, and an AND gate 1018. The upper limit value register 1011 stores the upper limit value of the count value, and the lower limit value register 1012 stores the lower limit value of the count value.

  The comparison unit 1014 receives the count value output from the digital circuit unit 900 from the B terminal, and receives the upper limit value of the count value from the upper limit value register 1011 via the A terminal. When the count value is smaller than the upper limit value, the comparison unit 1014 outputs a High signal to the AND gate 1018. On the other hand, when the count value is equal to or greater than the upper limit value, the comparison unit 1014 outputs a Low signal to the AND gate 1018. If the count value is greater than or equal to the upper limit value, the frequency of the back electromotive force waveform is lower than the lower limit value and the back electromotive force waveform is not measured normally, so the liquid container is not attached to the recording device or is attached securely. It may not have been.

  On the other hand, the comparison unit 1016 receives the count value output from the digital circuit unit 900 from the A terminal, and receives the lower limit value of the count value from the lower limit value register 1012 via the B terminal. When the count value is larger than the lower limit value, the comparison unit 1016 outputs a High signal to the AND gate 1018 and the terminal 1022. On the other hand, when the count value is equal to or lower than the lower limit value, the comparison unit 1016 outputs a Low signal to the AND gate 1018 and the terminal 1022. When the count value is equal to or lower than the lower limit value, it means that the liquid in the liquid container 1 does not exist at the mounting position of the actuator 106.

  When both the comparison units 1014 and 1016 output a High signal, that is, when the count value is smaller than the upper limit value and larger than the lower limit value, the AND gate 1018 outputs a High signal. In this case, since the frequency of the counter electromotive force waveform is lower than the upper limit value, the liquid in the liquid container 1 exists at the mounting position level of the actuator 106. Moreover, since the frequency of the back electromotive force waveform is higher than the lower limit value, it can be seen that the liquid container 1 is securely attached to the recording apparatus and the liquid exists at the attachment position level of the actuator 106. That is, when the terminal 1020 is High, the liquid container 1 is securely attached to the recording apparatus and the liquid is in a normal state where the liquid exists at the attachment position level of the actuator 106.

  When the comparison unit 1014 outputs a Low signal and the comparison unit 1016 outputs a High signal, that is, when the count value is greater than or equal to the upper limit value and greater than the lower limit value, the AND gate 1018 outputs a Low signal. A high signal is input to the terminal 1022. In this case, it is abnormal because the terminal 1020 is Low, and since the terminal 1022 is High, it can be determined that the liquid container 1 is not attached to the recording apparatus or is not attached securely.

  When the comparison unit 1014 outputs a High signal and the comparison unit 1016 outputs a Low signal, that is, when the count value is smaller than the upper limit value and less than or equal to the lower limit value, the AND gate 1018 outputs a Low signal. In this case, it is abnormal because the terminal 1020 is Low, and it can be seen that there is no liquid at the mounting position level of the actuator 106 because the terminal 1022 is Low.

FIG. 15 shows a method for manufacturing the actuator 106.
In FIG. 15, a plurality of actuators 106 (four in the example of FIG. 15) are integrally formed. The actuator 106 shown in FIG. 16 is manufactured by cutting the integrally molded product of the plurality of actuators shown in FIG. 15 at each actuator 106. When each piezoelectric element of the plurality of integrally formed actuators 106 shown in FIG. 15 is circular, the actuator 106 shown in FIG. 1 can be manufactured by cutting the integrally formed product in each actuator 106. By integrally forming the plurality of actuators 106, the plurality of actuators 106 can be efficiently manufactured at the same time, and handling during transportation becomes easy.

  The actuator 106 includes a thin plate or vibration plate 176, a substrate 178, an elastic wave generating means or piezoelectric element 174, a terminal forming member or upper electrode terminal 168, and a terminal forming member or lower electrode terminal 170.

  The piezoelectric element 174 includes a piezoelectric diaphragm or piezoelectric layer 160, an upper electrode 164, and a lower electrode 166. A vibration plate 176 is formed on the upper surface of the substrate 178, and a lower electrode 166 is formed on the upper surface of the vibration plate 176. A piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Therefore, the main part of the piezoelectric layer 160 is formed so as to be sandwiched from above and below by the main part of the upper electrode 164 and the main part of the lower electrode 166.

  In the case shown in FIG. 15, a plurality of (four in the example of FIG. 15) piezoelectric elements 174 are formed on the diaphragm 176. A lower electrode 166 is formed on the surface of the diaphragm 176, a piezoelectric layer 160 is formed on the surface of the lower electrode 166, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Upper electrode terminals 168 and lower electrode terminals 170 are formed at the ends of the upper electrode 164 and the lower electrode 166. The four actuators 106 are cut separately and used individually.

  FIG. 16 shows a cross section of a part of the actuator 106 having a rectangular piezoelectric element. FIG. 17 shows an entire cross section of the actuator 106 shown in FIG.

  As shown in FIG. 17, a through hole 178 a is formed on the surface of the substrate 178 facing the piezoelectric element 174. The through hole 178a is sealed by the vibration plate 176. The diaphragm 176 is made of an electrically insulating material that can be elastically deformed, such as alumina or zirconia oxide.

  A piezoelectric element 174 is formed on the vibration plate 176 at a position corresponding to the through hole 178a. The lower electrode 166 is formed on the surface of the diaphragm 176 so as to extend in one direction from the region of the through hole 178a, to the left in FIG. The upper electrode 164 is formed on the surface of the piezoelectric layer 160 so as to extend from the region of the through hole 178a in the direction opposite to the lower electrode, that is, rightward in FIG.

  The upper electrode terminal 168 and the lower electrode terminal 170 are formed on the upper surfaces of the auxiliary electrode 172 and the lower electrode 166, respectively. The lower electrode terminal 170 is in electrical contact with the lower electrode 166, and the upper electrode terminal 168 is in electrical contact with the upper electrode 164 through the auxiliary electrode 172, and between the piezoelectric element and the outside of the actuator 106. Deliver signals. The upper electrode terminal 168 and the lower electrode terminal 170 have a height equal to or higher than the height of the piezoelectric element 174 in which the electrodes 164 and 166 and the piezoelectric layer 160 are combined.

FIG. 18 shows a manufacturing method of the actuator 106 shown in FIG.
First, the through hole 40a is drilled in the green sheet 40 using a press or laser processing. The green sheet 40 becomes the substrate 178 after firing. The green sheet 40 is formed of a material such as ceramic.

  Next, another green sheet 41 is laminated on the surface of the green sheet 40. The green sheet 41 becomes the diaphragm 176 after firing. The green sheet 41 is formed of a material such as zirconia oxide.

  Next, the conductive layer 42, the piezoelectric layer 160, and the conductive layer 44 are sequentially formed on the surface of the green sheet 41 by a method such as pressure film printing. The conductive layer 42 later becomes the lower electrode 166, and the conductive layer 44 later becomes the upper electrode 164.

  Next, the formed green sheet 40, green sheet 41, conductive layer 42, piezoelectric layer 160, and conductive layer 44 are dried and fired.

  The spacer members 47 and 48 are members for raising the height of the upper electrode terminal 168 and the lower electrode terminal 170 to be higher than the piezoelectric element. The spacer members 47 and 48 are formed by printing or laminating the same material as the green sheets 40 and 41. By using the spacer members 47 and 48, the material of the upper electrode terminal 168 and the lower electrode terminal 170, which are noble metals, can be reduced. In addition, since the thickness of the upper electrode terminal 168 and the lower electrode terminal 170 can be reduced, the upper electrode terminal 168 and the lower electrode terminal 170 can be printed with high accuracy, and the height can be increased with high accuracy.

  When the conductive layer 42 is formed, the upper electrode terminal 168 and the lower electrode terminal 170 can be easily formed or firmly fixed by simultaneously forming the connection portion 44 ′ with the conductive layer 44 and the spacer members 47 and 48. . Finally, the upper electrode terminal 168 and the lower electrode terminal 170 are formed in the end regions of the conductive layer 42 and the conductive layer 44. When the upper electrode terminal 168 and the lower electrode terminal 170 are formed, the upper electrode terminal 168 and the lower electrode terminal 170 are formed so as to be electrically connected to the piezoelectric layer 160.

  FIG. 19 shows still another embodiment of an ink cartridge to which the present invention is applied. FIG. 19A is a cross-sectional view of the bottom of the ink cartridge according to the present embodiment. The ink cartridge of the present embodiment has a through hole 1c on the bottom surface 1a of the container 1 that stores ink. The bottom of the through-hole 1c is closed by the actuator 650 to form an ink reservoir.

  FIG. 19 (B) shows a detailed cross section of the actuator 650 and the through hole 1c shown in FIG. 19 (A). FIG. 19C shows a plane of the actuator 650 and the through hole 1c shown in FIG. The actuator 650 has a diaphragm 72 and a piezoelectric element 73 fixed to the diaphragm 72. The actuator 650 is fixed to the bottom surface of the container 1 so that the piezoelectric element 73 faces the through hole 1 c via the vibration plate 72 and the substrate 71. The diaphragm 72 is elastically deformable and has ink resistance.

  Depending on the amount of ink in the container 1, the amplitude and frequency of the counter electromotive force generated by the residual vibration of the piezoelectric element 73 and the diaphragm 72 change. Since the through hole 1c is formed at a position facing the actuator 650, a minimum amount of ink is secured in the through hole 1c. Therefore, the ink end of the container 1 can be reliably detected by measuring in advance the vibration characteristics of the actuator 650 determined by the amount of ink secured in the through hole 1c.

  FIG. 20 shows another embodiment of the through hole 1c. 20A, 20 </ b> B, and 20 </ b> C, the left diagram shows a state in which there is no ink K in the through hole 1 c, and the right diagram shows a state in which the ink K remains in the through hole 1 c. Indicates. In the embodiment of FIG. 19, the side surface of the through hole 1c is formed as a vertical wall. In FIG. 20A, the through-hole 1c has a side surface 1d that is slanted in the vertical direction and is open to the outside. In FIG. 20B, step portions 1e and 1f are formed on the side surface of the through hole 1c, and the upper step portion 1f is wider than the lower step portion 1e. In FIG. 20C, the through-hole 1c has a groove 1g extending in a direction in which the ink K is easily discharged, that is, in the direction of the ink supply port 2.

  According to the shape of the through hole 1c shown in FIGS. 20A to 20C, the amount of ink K in the ink reservoir can be reduced. Therefore, M ′ cav described with reference to FIGS. 1 and 2 can be made smaller than M ′ max. For this reason, the vibration characteristic of the actuator 650 at the time of ink end can be greatly different from that at the time of ink remaining in an amount of ink K that can be printed on the container 1, and the ink end can be detected more reliably. it can.

  FIG. 21 is a perspective view showing another embodiment of the actuator. The actuator 660 has a packing 76 outside the through-hole 1c of the diaphragm 72 constituting the actuator 660. A caulking hole 77 is formed on the outer periphery of the actuator 660. The actuator 660 is fixed to the container 1 by caulking through the caulking hole 77.

FIGS. 22A and 22B are perspective views showing still another embodiment of the actuator. In the present embodiment, the actuator 670 includes a recess forming substrate 80 and a piezoelectric element 82. A recess 81 is formed on one surface of the recess forming substrate 80 by a technique such as etching, and a piezoelectric element 82 is attached to the other surface.
Of the recess forming substrate 80, the bottom of the recess 81 acts as a vibration region. Therefore, the vibration region of the actuator 670 is defined by the peripheral edge of the recess 81.

  Actuator 670 is similar to the structure in which substrate 178 and diaphragm 176 are integrally formed in actuator 106 according to the embodiment of FIG. In this case, the manufacturing process when manufacturing the ink cartridge can be shortened, and the cost is reduced. The actuator 670 is preferably of a size that can be embedded in the through hole 1 c provided in the container 1. Thereby, the recess 81 can also act as a cavity. The actuator 106 according to the embodiment shown in FIG. 1 may be formed so as to be embedded in the through hole 1c, similarly to the actuator 670 according to the embodiment shown in FIG.

  FIG. 23 is a perspective view showing a configuration in which the actuator 106 is integrally formed as the mounting module body 100. The module body 100 is attached to a predetermined portion of the container 1 of the ink cartridge. The module body 100 is configured to detect the consumption state of the liquid in the container 1 by detecting a change in at least the acoustic impedance in the ink liquid.

  The module body 100 of the present embodiment includes a liquid container mounting portion 101 for mounting the actuator 106 to the container 1. The liquid container mounting portion 101 includes a base 102 having a substantially rectangular plane, and a cylindrical portion 116 on the base 102 that houses an actuator 106 that oscillates in response to a drive signal. The module body 100 is configured such that the actuator 106 of the module body 100 cannot be contacted from the outside when the module body 100 is attached to the ink cartridge. Thereby, the actuator 106 can be protected from external contact. The leading edge of the cylindrical portion 116 is rounded so that it can be easily fitted into a hole formed in the ink cartridge.

  24 is an exploded view of the module body 100 shown in FIG. The module body 100 includes a liquid container mounting portion 101 made of resin, and a piezoelectric device mounting portion 105 (see FIG. 23) having a plate 110 and a recess 113. Further, the module body 100 includes lead wires 104a and 104b, an actuator 106, and a film 108. Preferably, the plate 110 is made of a material that hardly rusts, such as stainless steel or a stainless alloy.

  The cylindrical portion 116 and the base 102 included in the liquid container mounting portion 101 are formed with an opening 114 at the center so that the lead wires 104a and 104b can be accommodated, and accommodate the actuator 106, the film 108, and the plate 110. A recess 113 is formed around the opening 114 so that it can be formed.

  The actuator 106 is joined to the plate 110 via the film 108, and the plate 110 and the actuator 106 are fixed to the recess 113 (the liquid container mounting portion 101). Therefore, the lead wires 104 a and 104 b, the actuator 106, the film 108, and the plate 110 are attached to the liquid container attaching portion 101 as a unit.

  The lead wires 104a and 104b are coupled to the upper electrode and the lower electrode of the actuator 106, respectively, and transmit a drive signal to the piezoelectric layer, while transmitting a resonance frequency signal detected by the actuator 106 to a recording device or the like.

  The actuator 106 oscillates temporarily based on the drive signal transmitted from the lead wires 104a and 104b. Further, the actuator 106 vibrates residually after oscillation, and generates back electromotive force by the vibration. At this time, the resonance frequency corresponding to the liquid consumption state in the liquid container can be detected by detecting the vibration period of the counter electromotive force waveform.

  The film 108 adheres the actuator 106 and the plate 110 to make the actuator liquid-tight. The film 108 is preferably formed of polyolefin or the like and bonded by heat fusion. When the actuator 106 and the plate 110 are bonded and fixed in a planar shape by the film 108, there is no variation depending on the bonding location, and portions other than the vibrating portion do not vibrate. Therefore, even if the actuator 106 is bonded to the plate 110, the vibration characteristics of the actuator 106 do not change.

  The plate 110 has a circular shape, and the opening 114 of the base 102 is formed in a cylindrical shape. The actuator 106 and the film 108 are formed in a rectangular shape. The lead wires 104 a and 104 b, the actuator 106, the film 108, and the plate 110 may be detachable from the base 102. The base 102, the lead wires 104 a and 104 b, the actuator 106, the film 108, and the plate 110 are disposed symmetrically with respect to the central axis of the module body 100. The centers of the base 102, the actuator 106, the film 108, and the plate 110 are disposed on the substantially central axis of the module body 100.

Further, the area of the opening 114 of the base 102 is formed larger than the area of the vibration region of the actuator 106. A through hole 112 is formed at a position facing the vibration portion of the actuator 106 at the center of the plate 110. As shown in FIGS. 1 and 2, the actuator 106 has a cavity 162, and the through hole 112 and the cavity 162 together form an ink reservoir. The thickness of the plate 110 is preferably smaller than the diameter of the through hole 112 in order to reduce the influence of residual ink. For example, it is preferable that the depth of the through hole 112 is not more than one third of the diameter. The through-hole 112 has a substantially perfect circular shape that is symmetric with respect to the central axis of the module body 100. Further, the area of the through hole 112 is larger than the opening area of the cavity 162 of the actuator 106. The peripheral edge of the cross section of the through hole 112 may have a taper shape or a step shape.
The module body 100 is mounted on the side, top, or bottom of the container 1 so that the through hole 112 faces the inside of the container 1. When the ink is consumed and the ink around the actuator 106 is exhausted, a change in the ink level can be detected based on a large change in the resonance frequency of the actuator 106.

  FIG. 25 is a perspective view showing another embodiment of the module body. In the module body 400 of this embodiment, a piezoelectric device mounting portion 405 is formed in the liquid container mounting portion 401. The liquid container mounting portion 401 includes a base 402 on a square whose plane is substantially rounded, and a columnar cylindrical portion 403 on the base 402. Further, the piezoelectric device mounting portion 405 includes a plate-like element 406 and a concave portion 413 that stand on the cylindrical portion 403. In the recess 413 provided on the side surface of the plate-like element 406, the actuator 106 is arranged vertically. Note that the tip of the plate-like element 406 is chamfered at a predetermined angle so that it can be easily fitted into a hole formed in the ink cartridge.

  26 is an exploded perspective view of the module body 400 shown in FIG. Similar to the module body 100 shown in FIG. 23, the module body 400 includes a liquid container mounting portion 401 and a piezoelectric device mounting portion 405. The liquid container mounting portion 401 has a base 402 and a cylindrical portion 403, and the piezoelectric device mounting portion 405 has a plate-like element 406 and a recess 413. The actuator 106 is joined to the plate 410 and fixed to the recess 413. The module body 400 further includes lead wires 404a and 404b, an actuator 106, and a film 408.

  In the present embodiment, the plate 410 has a rectangular shape, and the opening 414 provided in the plate-like element 406 is also formed in a rectangular shape. The lead wires 404 a and 404 b, the actuator 106, the film 408, and the plate 410 may be configured to be detachable from the base 402. The actuator 106, the film 408, and the plate 410 are disposed symmetrically with respect to a central axis that passes through the center of the opening 414 and extends in the vertical direction with respect to the plane of the opening 414. Further, the centers of the actuator 406, the film 408, and the plate 410 are disposed on the substantially central axis of the opening 414.

  The area of the through hole 412 provided at the center of the plate 410 is formed larger than the area of the opening of the cavity 162 of the actuator 106. The cavity 162 and the through hole 412 of the actuator 106 together form an ink reservoir. The thickness of the plate 410 is smaller than the diameter of the through hole 412, and is preferably set to a size equal to or less than one third of the diameter of the through hole 412, for example. The through hole 412 has a substantially perfect circular shape that is symmetric with respect to the central axis of the module body 400. The peripheral edge of the cross section of the through hole 412 may be a taper shape or a step shape. The module body 400 can be attached to the bottom of the container 1 such that the through hole 412 is disposed inside the container 1. Since the actuator 106 is disposed in the container 1 so as to extend in the vertical direction, the ink end point is set by changing the height at which the actuator 106 is disposed in the container 1 by changing the height of the base 402. Can be easily changed.

  FIG. 27 shows still another embodiment of the module body. Similar to the module body 100 shown in FIG. 23, the module body 500 of FIG. 27 includes a liquid container mounting portion 501 having a base 502 and a cylindrical portion 503. The module body 500 further includes lead wires 504a and 504b, an actuator 106, a film 508, and a plate 510. The base 502 included in the liquid container mounting portion 501 has an opening 514 at the center so that the lead wires 504a and 504b can be accommodated, and the opening 514 so that the actuator 106, the film 508, and the plate 510 can be accommodated. A recess 513 is formed around The actuator 106 is fixed to the piezoelectric device mounting portion 505 via the plate 510. Therefore, the lead wires 504a and 504b, the actuator 106, the film 508, and the plate 510 are integrally attached to the liquid container attachment portion 501.

  In the module body 500 of the present embodiment, a cylindrical portion 503 whose upper surface is slanted in the vertical direction is formed on a square base 502 having a substantially rounded plane. The actuator 106 is disposed on a concave portion 513 provided obliquely in the vertical direction on the upper surface of the cylindrical portion 503.

  That is, the tip of the module body 500 is inclined, and the actuator 106 is mounted on the inclined surface. For this reason, when the module body 500 is mounted on the bottom or side of the container 1, the actuator 106 is disposed so as to be inclined with respect to the vertical direction of the container 1. The inclination angle of the tip of the module body 500 is preferably between approximately 30 ° and 60 ° in view of detection performance.

  The module body 500 is mounted on the bottom or side of the container 1 so that the actuator 106 is disposed in the container 1. When the module body 500 is attached to the side portion of the container 1, the actuator 106 is attached to the container 1 so as to face the upper side, the lower side, or the lateral side of the container 1 while being inclined. On the other hand, when the module body 500 is mounted on the bottom of the container 1, it is preferable that the actuator 106 is attached to the container 1 so as to face the ink supply port side of the container 1 while being inclined.

  FIG. 28 is a cross-sectional view of the vicinity of the bottom of the ink container when the module body 100 shown in FIG. The module body 100 is mounted so as to penetrate the side wall of the container 1. An O-ring 365 is provided on the joint surface between the side wall of the container 1 and the module body 100 to keep the module body 100 and the container 1 liquid-tight. Thus, in order to be able to seal with an O-ring, the module body 100 preferably includes a cylindrical portion as described with reference to FIG.

  When the tip of the module body 100 is inserted into the container 1, the ink in the container 1 comes into contact with the actuator 106 through the through hole 112 of the plate 110. Since the resonance frequency of the residual vibration of the actuator 106 differs depending on whether the periphery of the vibration part of the actuator 106 is liquid or gas, the ink consumption state can be detected using the module body 100.

  In addition to the module body 100, the module body 400 shown in FIG. 25, the module body 500 shown in FIG. 27, or the module bodies 700A, 700B, 750A, and 750B shown in FIG. 29 and FIG. The body 600 may be attached to the container 1 to detect the presence or absence of ink.

  FIG. 29 shows still another embodiment of the module body 100. A module body 750A in FIG. 29A includes an actuator 106b and a base portion 360. The module body 750 </ b> A is attached to the container 1 so that the front surface thereof is substantially integrated with the inner surface of the side wall of the container 1. The actuator 106b includes a piezoelectric layer 160, an upper electrode 164, a lower electrode 166, and a diaphragm 176. A lower electrode 166 is formed on the upper surface of the diaphragm 176. A piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Accordingly, the piezoelectric layer 160 is formed so as to be sandwiched from above and below by the upper electrode 164 and the lower electrode 166. The piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element. The piezoelectric element is formed on the vibration plate 176. The vibration region of the piezoelectric element and the diaphragm 176 is a vibration part where the actuator actually vibrates. A through hole 385 is provided in the side wall of the container 1. Therefore, the ink comes into contact with the vibration plate 176 through the through hole 385 of the container 1.

  Next, the operation of the module body 750A illustrated in FIG. 29A will be described. The upper electrode 164 and the lower electrode 166 transmit a drive signal to the piezoelectric layer 160 and a signal having a resonance frequency detected by the piezoelectric layer 160 to the recording device. The piezoelectric layer 160 oscillates by a drive signal transmitted by the upper electrode 164 and the lower electrode 166, and then oscillates residually. Due to this residual vibration, the piezoelectric layer 160 generates a counter electromotive force. The presence or absence of ink can be detected by counting the vibration period of the counter electromotive force waveform and detecting the resonance frequency at that time.

  In the module body 750A, the surface opposite to the piezoelectric element side of the vibrating portion of the actuator 106b, that is, as shown in FIG. 29A, only the vibrating plate 176 comes into contact with the ink in the ink container 1. ing. In the module body 750A of FIG. 29A, it is not necessary to embed the electrodes of the lead wires (104a, 104b, 404a, 404b, 504a, and 504b) shown in FIGS. 23 to 27 in the module body. For this reason, a shaping | molding process is simplified. Furthermore, the module body 750A can be replaced or recycled. Furthermore, since the actuator 106b is protected by the base 360, the actuator 106b can be protected from contact with the outside.

  FIG. 29B shows still another embodiment of the module body. A module body 750B in FIG. 29B includes an actuator 106b and a base portion 360. The module body 750B is mounted on the container 1 so that the front surface thereof is substantially integrated with the inner surface of the side wall of the container 1. The actuator 106b includes a piezoelectric layer 160, an upper electrode 164, a lower electrode 166, and a diaphragm 176. A lower electrode 166 is formed on the upper surface of the diaphragm 176. A piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Accordingly, the piezoelectric layer 160 is formed so as to be sandwiched from above and below by the upper electrode 164 and the lower electrode 166. The piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element. The piezoelectric element is formed on the vibration plate 176. The vibration region of the piezoelectric element and the diaphragm 176 is a vibration part where the actuator actually vibrates. A thin wall portion 380 is provided on the side wall of the container 1. In the module body 750B, the surface opposite to the piezoelectric element side of the vibration portion of the actuator 106b, that is, as shown in FIG. 29B, only the vibration plate 176 is in contact with the thin wall portion 380 of the ink container 1. Is attached to the container 1. Therefore, the vibration part of the actuator 106b vibrates with the thin wall part 380.

  Next, the operation of the module body 750B illustrated in FIG. 29B will be described. The upper electrode 164 and the lower electrode 166 transmit a drive signal to the piezoelectric layer 160 and a signal having a resonance frequency detected by the piezoelectric layer 160 to the recording device. The piezoelectric layer 160 oscillates by a drive signal transmitted by the upper electrode 164 and the lower electrode 166, and then oscillates at a resonance period. Since the vibration plate 176 is in contact with the thin wall portion 380 of the container 1, the vibration portion of the actuator 106 b vibrates with the thin wall portion 380. Since the inner surface side of the container 1 of the thin wall portion 380 is in contact with ink, when the actuator 106b vibrates with the thin wall portion 380, the resonance frequency and amplitude of the residual vibration change depending on the remaining amount of ink. Due to this residual vibration, the piezoelectric layer 160 generates a counter electromotive force. The remaining amount of ink can be detected by counting the vibration period of the counter electromotive force waveform and detecting the resonance frequency at that time.

  In the module body 750B of FIG. 29B, it is not necessary to embed electrodes of the lead wires (104a, 104b, 404a, 404b, 504a, and 504b) shown in FIGS. 23 to 27 in the module body. For this reason, a shaping | molding process is simplified. Further, the module body 750B can be replaced or recycled. Furthermore, since the actuator 106b is protected by the base 360, the actuator 106b can be protected from contact with the outside.

  FIG. 30A shows a cross-sectional view of the ink container when the module body 700B is mounted on the container 1. FIG. In the case of FIG. 30A, the module body 700B is used as one of the mounting structures. The module body 700B is mounted on the container 1 such that the liquid container mounting portion 360 protrudes into the container 1. A through hole 370 is formed in the mounting plate 350, and the through hole 370 faces the vibration portion of the actuator 106b. Further, a hole 382 is formed in the bottom wall of the module body 700B, and a piezoelectric device mounting portion 363 is formed. The actuator 106b is provided so as to close the hole 382.

  Therefore, the ink comes into contact with the vibration plate 176 through the hole 382 of the piezoelectric device mounting portion 363 and the through hole 370 of the mounting plate 350. The hole 382 of the piezoelectric device mounting portion 363 and the through hole 370 of the mounting plate 350 together form an ink reservoir. The piezoelectric device mounting portion 363 and the actuator 106b are fixed by a mounting plate 350 and a film member. Further, a sealing structure 372 is provided at a connection portion between the liquid container mounting portion 360 and the container 1. The sealing structure 372 may be formed of a plastic material such as a synthetic resin, or may be formed of an O-ring. Although the module body 700B and the container 1 in FIG. 30A are separate bodies, as shown in FIG. 30B, the piezoelectric device mounting portion of the module body 700B may be constituted by a part of the container 1. .

  In the module body 700B of FIG. 30A, the lead wires shown in FIGS. 23 to 27 need not be embedded in the module body. For this reason, a shaping | molding process is simplified. Furthermore, the module body 700B can be replaced and recycled.

  When the ink cartridge is shaken, the ink may adhere to the upper surface or the side surface of the container 1. Such ink may hang down from the upper surface or side surface of the container 1 and come into contact with the actuator 106b, causing the actuator 106b to malfunction. However, when the liquid container mounting portion 360 of the module 700B protrudes into the container 1, the actuator 106b does not malfunction due to ink dripping from the upper surface or side surface of the container 1.

  In the example of FIG. 30A, only a part of the vibration plate 176 and the mounting plate 350 is attached to the container 1 so as to come into contact with the ink in the container 1.

  FIG. 30B is a cross-sectional view of the ink container for another example when the actuator 106 b is mounted on the container 1. In the ink cartridge according to the example of FIG. 30B, the protection member 361 is attached to the container 1 as a separate body from the actuator 106b. Therefore, the protection member 361 and the actuator 106b are not integrated as a module. However, the protection member 361 can protect the actuator 106b from being touched by the user's hand. A hole 380 is provided in the side wall of the container 1 corresponding to the front surface of the actuator 106b.

  The actuator 106 b includes a piezoelectric layer 160, an upper electrode 164, a lower electrode 166, a vibration plate 176 and a mounting plate 350. A vibration plate 176 is formed on the upper surface of the mounting plate 350, and a lower electrode 166 is formed on the upper surface of the vibration plate 176. A piezoelectric layer 160 is formed on the upper surface of the lower electrode 166, and an upper electrode 164 is formed on the upper surface of the piezoelectric layer 160. Accordingly, the main part of the piezoelectric layer 160 is formed so as to be sandwiched from above and below by the main part of the upper electrode 164 and the main part of the lower electrode 166. The circular portions that are the main parts of the piezoelectric layer 160, the upper electrode 164, and the lower electrode 166 form a piezoelectric element. The piezoelectric element is formed on the vibration plate 176. The vibration region of the piezoelectric element and the diaphragm 176 is a vibration part where the actuator actually vibrates. A through hole 370 is provided in the mounting plate 350. Therefore, the ink contacts the vibration plate 176 through the hole 380 of the container 1 and the through hole 370 of the mounting plate 350. The hole 380 of the container 1 and the through hole 370 of the mounting plate 350 together form an ink reservoir. In the example of FIG. 30B, the actuator 106b is protected from contact with the outside by the protective member 361.

  Note that the actuator 106b and the mounting plate 350 in the examples of FIGS. 30A and 30B can be replaced with the actuator 106 having the substrate 178 of FIG.

  FIG. 30C shows an embodiment including a mold structure 600 including an actuator 106b. In the example of FIG. 30C, a mold structure 600 is used as one of the attachment structures. The mold structure 600 includes an actuator 106b and a mold part 364. The actuator 106b and the mold part 364 are integrally formed. The mold part 364 is formed of a plastic material such as silicon resin. The mold part 364 is formed to have two legs extending from the actuator 106b side. The foot portion of the mold portion 364 has a lead wire 362 inside. The mold part 364 has two leg ends of the mold part 364 formed in a hemispherical shape outside the container 1 in order to fix the mold part 364 and the container 1 in a liquid-tight manner. The mold part 364 is attached to the container 1 so that the actuator 106 b protrudes into the container 1. As a result, the vibration part of the actuator 106 b comes into contact with the ink in the container 1. The mold part 364 protects the upper electrode 164, the piezoelectric layer 160, and the lower electrode 166 of the actuator 106b from contact with ink.

  The mold structure 600 in FIG. 30C does not require the sealing structure 372 between the mold part 364 and the container 1, and thus ink is difficult to leak from the container 1. Further, since the mold structure 600 does not protrude from the outside of the container 1, the actuator 106b can be protected from contact with the outside. In the mold structure 600, since the mold part 364 protrudes into the container 1, the actuator 106b does not malfunction due to ink dripping from the upper surface or side surface of the container 1.

  FIG. 31 shows an embodiment of an ink cartridge and an ink jet recording apparatus using the actuator 106 shown in FIG. The plurality of ink cartridges 180 are mounted on an ink jet recording apparatus having a plurality of ink introduction portions 182 and holders 184 corresponding to the respective ink cartridges 180. The plurality of ink cartridges 180 contain different types of ink, for example, different colors. On the bottom surface of each of the plurality of ink cartridges 180, an actuator 106 that is a means for detecting at least acoustic impedance is mounted. By mounting the actuator 106 on the ink cartridge 180, the remaining amount of ink in the ink cartridge 180 can be detected.

  FIG. 32 shows details of the vicinity of the head portion of the ink jet recording apparatus. The ink jet recording apparatus includes an ink introduction unit 182, a holder 184, a head plate 186, and a nozzle plate 188. A plurality of nozzles 190 that eject ink are formed on the nozzle plate 188.

The ink introduction part 182 has an air supply port 181 and an ink introduction port 183.
The air supply port 181 supplies air to the ink cartridge 180. Ink is introduced from the ink cartridge 180 into the ink inlet 183.

  The ink cartridge 180 has an air introduction port 185 and an ink supply port 187. Air is introduced into the air introduction port 185 from the air supply port 181 of the ink introduction unit 182. The ink supply port 187 supplies ink to the ink introduction port 183 of the ink introduction unit 182. By introducing air into the ink cartridge 180 from the air introduction port 185, supply of ink from the ink cartridge 180 to the ink introduction unit 182 is promoted. The holder 184 communicates the ink supplied from the ink cartridge 180 via the ink introduction part 182 to the head plate 186.

FIG. 33 shows another embodiment of the ink cartridge 180 shown in FIG.
In the ink cartridge 180A in FIG. 33A, the actuator 106 is mounted on a bottom surface 194a formed obliquely in the vertical direction. Since the actuator 106 is mounted obliquely with respect to the vertical direction of the ink container 194, the ink can be swept well.

  Inside the ink container 194 of the ink cartridge 180, a wave preventing wall 192 is provided at a position facing the actuator 106 at a predetermined height from the inner bottom surface of the ink container 194. A gap filled with ink is formed between the actuator 106 and the wave barrier 192. The interval between the wave preventing wall 192 and the actuator 106 is set to such an extent that the ink is not retained by the capillary force.

  When the ink container 194 rolls, an ink wave is generated inside the ink container 194. Due to the impact, gas or bubbles may be detected by the actuator 106 and the actuator 106 may malfunction. However, by providing the wave preventing wall 192, it is possible to prevent ink waves near the actuator 106 and prevent malfunction of the actuator 106.

  The actuator 106 of the ink cartridge 180B shown in FIG. 33B is mounted on the side wall of the supply port of the ink container 194. The actuator 106 may be mounted on the side wall or bottom surface of the ink container 194 as long as it is in the vicinity of the ink supply port 187. The actuator 106 is preferably attached to the center of the ink container 194 in the width direction.

  Since the ink passes through the ink supply port 187 and is supplied to the outside, providing the actuator 106 in the vicinity of the ink supply port 187 ensures that the ink and the actuator 106 come into contact until the ink near end point. Therefore, the actuator 106 can reliably detect the time point of the ink near end.

  Further, by providing the actuator 106 in the vicinity of the ink supply port 187, the positioning of the actuator 106 on the ink container and the contact on the carriage is ensured when the ink container is mounted on the cartridge holder on the carriage. The reason for this is that the most important factor in the connection between the ink container and the carriage is a reliable connection between the ink supply port and the supply needle. If there is any deviation between them, the tip of the supply needle is damaged, or a sealing structure such as an O-ring is damaged, and ink leaks out. In order to prevent such a problem, the ink jet printer usually has a special structure that allows accurate alignment when the ink container is mounted on the carriage. Therefore, by arranging the actuator in the vicinity of the supply port, the alignment of the actuator can be ensured at the same time. Further, by mounting the actuator 106 at the center in the width direction of the ink container 194, more reliable alignment can be realized. This is because, when the ink container is mounted on the holder, when the shaft swings around the center line in the width direction, the vibration is the least.

  FIG. 34 shows still another embodiment of the ink cartridge 180. 34A is a cross-sectional view of the ink cartridge 180C, FIG. 34B is an enlarged cross-sectional view of the side wall 194b of the ink cartridge 180C shown in FIG. 34A, and FIG. It is a perspective view from the front.

  In the ink cartridge 180C, the semiconductor storage means 7 and the actuator 106 are formed on the same circuit board 610. As shown in FIGS. 34B and 34C, the semiconductor memory means 7 is formed above the circuit board 610, and the actuator 106 is formed below the semiconductor memory means 7 on the same circuit board 610. .

  An odd-shaped O-ring 614 is attached to the side wall 194b so as to surround the periphery of the actuator 106. A plurality of crimping portions 616 for joining the circuit board 610 to the ink container 194 are formed on the side wall 194b. The circuit board 610 is joined to the ink container 194 via the crimping portion 616, and the atypical O-ring 614 is pressed against the circuit board 610, so that the vibration region of the actuator 106 can come into contact with the ink, and the ink cartridge Keep the exterior and interior fluid-tight.

  Terminals 612 are formed in the semiconductor memory means 7 and in the vicinity of the semiconductor memory means 7. The terminal 612 exchanges signals between the semiconductor storage means 7 and the outside of the inkjet storage device or the like. The semiconductor memory means 7 can be constituted by a rewritable semiconductor memory such as an EEPROM. Since the semiconductor storage means 7 and the actuator 106 are formed on the same circuit board 610, a single attachment process is sufficient when the actuator 106 and the semiconductor storage means 7 are attached to the ink cartridge 180C. Further, the work process at the time of manufacturing and recycling the ink cartridge 180C is simplified. Furthermore, since the number of parts is reduced, the manufacturing cost of the ink cartridge 180C can be reduced.

  The actuator 106 detects the ink consumption state in the ink container 194. The semiconductor storage unit 7 stores ink information such as the remaining amount of ink detected by the actuator 106. In addition, the semiconductor storage unit 7 stores information on characteristic parameters such as the characteristics of ink and ink cartridges used when detecting the remaining amount of ink.

  The semiconductor storage means 7 is used when the ink in the ink container 194 is full, that is, when the ink is filled in the ink container 194, or when the ink is at the end, that is, when the ink in the ink container 194 is consumed. The resonance frequency is stored as one of the characteristic parameters. The resonance frequency when the ink in the ink container 194 is full or in an end state may be stored when the ink container is first attached to the ink jet recording apparatus. Further, the resonance frequency when the ink in the ink container 194 is full or in an end state may be stored during the manufacture of the ink container 194.

  The resonance frequency when the ink in the ink container 194 is full or end is stored in the semiconductor storage unit 7 in advance, and the resonance frequency data is read on the ink jet recording apparatus side, thereby detecting variations in the remaining ink amount. Can be corrected. As a result, it is possible to accurately detect that the remaining amount of ink has decreased to the reference value.

  FIG. 35 shows still another embodiment of the ink cartridge 180. In the ink cartridge 180D shown in FIG. 35A, a plurality of actuators 106 are mounted on the side wall 194b of the ink container 194. The plurality of integrally formed actuators 106 shown in FIG. 15 are preferably used as each of the plurality of actuators 106. The plurality of actuators 106 are arranged on the side wall 194b at intervals in the vertical direction. By disposing a plurality of actuators 106 on the side wall 194b at intervals in the vertical direction, the remaining amount of ink can be detected stepwise.

  In an ink cartridge 180E shown in FIG. 35B, an actuator 606 that is long in the vertical direction is mounted on the side wall 194b of the ink container 194. A change in the remaining amount of ink in the ink container 194 can be continuously detected by the actuator 606 that is long in the vertical direction. The length of the actuator 606 is desirably more than half the height of the side wall 194b. The actuator 606 in FIG. 35B has a length from the upper end to the lower end of the side wall 194b.

  In the ink cartridge 180F shown in FIG. 35C, a plurality of actuators 106 are mounted on the side wall 194b of the ink container 194 in the same manner as the ink cartridge 180D shown in FIG. In addition, a wave barrier 192 that is long in the vertical direction is provided with a predetermined interval facing the plurality of actuators 106. The plurality of integrally formed actuators 106 shown in FIG. 15 are preferably used as each of the plurality of actuators 106.

  A gap filled with ink is formed between the actuator 106 and the wave barrier 192. Further, the interval between the wave preventing wall 192 and the actuator 106 is set to such an extent that the ink is not retained by the capillary force.

  When the ink container 194 rolls, an ink wave is generated inside the ink container 194. Due to the impact, gas or bubbles are detected by the actuator 106, and the actuator 106 may malfunction. However, by providing the wave preventing wall 192 as shown in FIG. 35C, it is possible to prevent the ink from flowing near the actuator 106 and to prevent the actuator 106 from malfunctioning. Further, the wave preventing wall 192 prevents bubbles generated by the ink swinging from entering the actuator 106.

  FIG. 36 shows still another embodiment of the ink cartridge 180. The ink cartridge 180G in FIG. 36A includes a plurality of partition walls 212 extending downward from the upper surface 194c of the ink container 194. The lower end of each partition wall 212 and the bottom surface of the ink container 194 are spaced apart from each other by a predetermined distance, and the bottom part of the ink container 194 communicates. The ink cartridge 180G has a plurality of storage chambers 213 defined by a plurality of partition walls 212, respectively. The bottoms of the plurality of storage chambers 213 communicate with each other.

  In each of the plurality of storage chambers 213, the actuator 106 is mounted on the upper surface 194c of the ink container 194. The integrally molded actuator 106 shown in FIG. 15 is preferably used as each of the plurality of actuators 106. The actuator 106 is disposed approximately at the center of the upper surface 194 c of the storage chamber 213 of the ink container 194.

  The capacity of the storage chamber 213 is the largest on the ink supply port 187 side, and gradually decreases as the ink supply port 187 moves away from the ink container 194. Therefore, the interval at which the actuator 106 is disposed is wider on the ink supply port 187 side and becomes narrower as the ink supply port 187 moves away from the ink container 194.

  Ink is discharged from the ink supply port 187 and air enters from the air introduction port 185. For this reason, the ink in the storage chamber 213 at the back of the ink cartridge 180G is consumed in order from the ink in the storage chamber 213 on the ink supply port 187 side. For example, while the ink in the storage chamber 213 closest to the ink supply port 187 is consumed and the ink level in the storage chamber 213 closest to the ink supply port 187 is lowered, the other storage chamber 213 is filled with ink. ing. When the ink in the storage chamber 213 closest to the ink supply port 187 is consumed, air enters the second storage chamber 213 counted from the ink supply port 187 and the ink in the second storage chamber 213 is consumed. For the first time, the ink level in the second storage chamber 213 begins to drop. At this time, the third and subsequent storage chambers 213 counted from the ink supply chamber 187 are filled with ink. In this way, ink is consumed in order from the storage chamber 213 close to the ink supply port 187 to the storage chamber 213 far away.

  As described above, the actuator 106 is disposed on the upper surface 194c of the ink container 194 for each of the storage chambers 213, so that the actuator 106 can detect a decrease in the ink amount in stages. Further, since the capacity of the storage chamber 213 gradually decreases from the ink supply port 187 toward the back, the time interval for the actuator 106 to detect the decrease in the ink amount gradually decreases, and the frequency approaches the ink end. Can be detected high.

  The ink cartridge 180H of FIG. 36B has one partition wall 212 extending downward from the upper surface 194c of the ink container 194. The lower end of the partition wall 212 and the bottom surface of the ink container 194 are spaced apart from each other by a predetermined distance, and the bottom part of the ink container 194 communicates. The ink cartridge 180H has two storage chambers 213a and 213b that are partitioned by a partition wall 212. The bottoms of the storage chambers 213a and 213b communicate with each other.

  The capacity of the storage chamber 213a on the ink supply port 187 side is larger than the capacity of the storage chamber 213b at the back as viewed from the ink supply port 187. In particular, the capacity of the storage chamber 213b is preferably smaller than half of the capacity of the storage chamber 213a.

  The actuator 106 is mounted on the upper surface 194c of the storage chamber 213b. Further, the storage chamber 213b is formed with a buffer 214, which is a groove for catching air bubbles entering when the ink cartridge 180H is manufactured. In FIG. 36B, the buffer 214 is formed as a groove extending upward from the side wall 194 b of the ink container 194. The buffer 214 captures bubbles that have entered the ink storage chamber 213b. For this reason, it is possible to prevent the actuator 106 from erroneously recognizing the ink end due to bubbles.

  Since the actuator 106 is provided on the upper surface 194c of the storage chamber 213b, the ink amount from the detection of the ink near end to the complete ink end state in the storage chamber 213a ascertained by the dot counter. By applying correction corresponding to the ink consumption state, ink can be consumed to the end. Furthermore, by adjusting the capacity of the storage chamber 213b by changing the length or interval of the partition wall 212, the amount of ink that can be consumed after ink near-end detection can be changed.

  An ink cartridge 180I in FIG. 36C is obtained by filling a porous member 216 in the accommodation chamber 213b of the ink cartridge 180H in FIG. The porous member 216 is installed so as to fill the entire space from the upper surface to the lower surface in the accommodation chamber 213b, and is in contact with the actuator.

  When the ink container falls down or during reciprocation on the carriage, air may enter the ink storage chamber 213b, which may cause the actuator 106 to malfunction. However, if the porous member 216 is provided, the porous member 21 captures air, so that the actuator 106 and the air can be prevented from contacting each other. Further, since the porous member 216 also holds ink, it is possible to prevent the ink from being applied to the actuator 106 and causing the actuator 106 to erroneously detect that there is no ink even when the ink container is shaken. The porous member 216 is preferably installed in the accommodation chamber 213 having the smallest capacity.

  Since the actuator 106 is provided on the upper surface 194c of the storage chamber 213b, the ink amount from the detection of the ink near end to the complete ink end state in the storage chamber 213a ascertained by the dot counter. By applying correction corresponding to the ink consumption state, ink can be consumed to the end. Furthermore, by adjusting the capacity of the storage chamber 213b by changing the length or interval of the partition wall 212, the amount of ink that can be consumed after ink near-end detection can be changed.

  An ink cartridge 180J shown in FIG. 36D is obtained by forming the porous member 216 of the ink cartridge 180I shown in FIG. 36C with two types of porous members 216A and 216B having different hole diameters. The porous member 216A is disposed above the porous member 216B. The hole diameter of the upper porous member 216A is larger than the hole diameter of the lower porous member 216B. Alternatively, the porous member 216A may be formed of a member having a lower liquid affinity than the porous member 216B.

  Since the porous member 216B having a smaller pore diameter has a larger capillary force than the porous member 216A having a larger pore diameter, the ink in the storage chamber 213b is collected and held in the lower porous chamber member 216B. Therefore, once the air reaches the actuator 106 and the actuator 106 detects the absence of ink, the ink reaches the actuator again and the actuator 106 does not detect the presence of ink. Furthermore, since the ink is absorbed by the porous member 216 </ b> B far from the actuator 106, ink in the vicinity of the actuator 106 is good. For this reason, the amount of change in the acoustic impedance change when detecting the presence or absence of ink increases.

  Since the actuator 106 is provided on the upper surface 194c of the storage chamber 213b, the ink amount from the detection of the ink near end to the complete ink end state in the storage chamber 213a ascertained by the dot counter. By applying correction corresponding to the ink consumption state, ink can be consumed to the end. Furthermore, by adjusting the capacity of the storage chamber 213b by changing the length or interval of the partition wall 212, the amount of ink that can be consumed after ink near-end detection can be changed.

  FIG. 37A is a cross-sectional view showing an ink cartridge 180K that is an embodiment in which the ink cartridge 180I shown in FIG. 36C is modified. The lower part of the porous member 216 of the ink cartridge 180K shown in FIG. 37A is compressed so as to gradually decrease toward the bottom surface of the ink container 194 so that the horizontal sectional area and the hole diameter become small. Designed. As shown in FIG. 37A, the ink cartridge 180K is provided with ribs on the side walls in order to compress the lower part of the porous member 216 so that the hole diameter thereof becomes smaller. Since the pore diameter at the bottom of the porous member 216 is reduced by being compressed, the ink is collected and held at the bottom of the porous member 216. Since the ink is absorbed by the lower portion of the porous member 216 far from the actuator 106, the ink in the vicinity of the actuator 106 is good. For this reason, the amount of change in the acoustic impedance change when detecting the presence or absence of ink increases. Therefore, it is possible to prevent the ink from being applied to the actuator 106 mounted on the upper surface of the ink cartridge 180K due to the shaking of the ink, and the actuator 106 from erroneously detecting that there is no ink.

  On the other hand, the ink cartridge 180L in FIGS. 37B and 37C is compressed so that the lower portion of the porous member 216 gradually decreases toward the bottom surface of the ink container 194 in the width direction of the ink container 194. The horizontal sectional area and the hole diameter gradually decrease toward the bottom surface of the ink container 194. Since the pore diameter at the bottom of the porous member 216 is reduced by being compressed, the ink is collected and held at the bottom of the porous member 216. Since the ink is absorbed by the lower portion of the porous member 216B far from the actuator 106, the ink in the vicinity of the actuator 106 is good. For this reason, the amount of change in the acoustic impedance change when detecting the presence or absence of ink increases. Accordingly, it is possible to prevent ink from being applied to the actuator 106 mounted on the upper surface of the ink cartridge 180L due to the shaking of the ink, and the actuator 106 from erroneously detecting that there is no ink.

  FIG. 38A shows still another embodiment of the ink cartridge using the actuator 106. The ink cartridge 220A shown in FIG. 38A includes a first partition 222 provided so as to extend downward from the upper surface of the ink cartridge 220A. A predetermined gap is provided between the lower end of the first partition 222 and the bottom surface of the ink cartridge 220A so that ink can flow into the ink supply port 230 through the bottom surface of the ink cartridge 220A. A second partition 224 is formed on the ink supply port 230 side with respect to the first partition 222 so as to extend upward from the bottom surface of the ink cartridge 220A. A predetermined gap is provided between the upper end of the second partition 224 and the upper surface of the ink cartridge 220A, so that ink can flow into the ink supply port 230 through the upper surface of the ink cartridge 220A.

  A first storage chamber 225 a is formed in the back of the first partition 222 when viewed from the ink supply port 230 by the first partition 222. On the other hand, the second partition 224 forms a second storage chamber 225 b on the front side of the second partition 224 when viewed from the ink supply port 230. The capacity of the first storage chamber 225a is larger than the capacity of the second storage chamber 225b. Between the first partition wall 222 and the second partition wall 224, a space enough to cause capillary action is formed, that is, a capillary channel 227 is formed. Therefore, the ink in the first storage chamber 225 a is collected in the capillary passage 227 by the capillary force of the capillary passage 227. For this reason, it can prevent that gas and a bubble mix in the 2nd storage chamber 225b. Further, the water level of the ink in the second storage chamber 225b can be gradually and stably lowered. Since the first storage chamber 225a is formed behind the second storage chamber 225b when viewed from the ink supply port 230, after the ink in the first storage chamber 225a is consumed, the second storage chamber 225b of ink is consumed.

  The actuator 106 is attached to the side wall on the ink supply port 230 side of the ink cartridge 220A, that is, the side wall on the ink supply port 230 side of the second storage chamber 225b. The actuator 106 detects the ink consumption state in the second storage chamber 225b. By mounting the actuator 106 on the side wall of the second storage chamber 225b, it is possible to stably detect the remaining amount of ink at a point closer to the ink end. Furthermore, by changing the height at which the actuator 106 is mounted on the side wall of the second storage chamber 225b, it is possible to freely set at which point the remaining amount of ink is used as the ink end.

  Since ink is supplied from the first storage chamber 225a to the second storage chamber 225b via the capillary passage 227, the actuator 106 is hardly affected by the roll of the ink due to the roll of the ink cartridge 220A. Therefore, the actuator 106 can more reliably measure the remaining ink amount. Furthermore, since the capillary passage 227 holds the ink, the ink is prevented from flowing back from the second storage chamber 225b to the first storage chamber 225a.

  A check valve 228 is provided on the upper surface of the ink cartridge 220A. The check valve 228 prevents ink from leaking outside the ink cartridge 220A when the ink cartridge 220A rolls. Further, by installing the check valve 228 on the upper surface of the ink cartridge 220A, it is possible to prevent evaporation of the ink from the ink cartridge 220A. When the ink in the ink cartridge 220A is consumed and the negative pressure in the ink cartridge 220A exceeds the pressure of the check valve 228, the check valve 228 is opened and air is sucked into the ink cartridge 220A. Thereby, the pressure in the ink cartridge 220A is kept substantially constant.

FIGS. 38C and 38D are cross-sectional views showing details of the check valve 228.
The check valve 228 shown in FIG. 38C includes a valve 232 having a blade 232a formed of rubber. The blade 232 a faces the air hole 233 facing the outside of the ink cartridge 220. The ventilation hole 233 is opened and closed by the deformation of the blade 232a. That is, when the ink in the ink cartridge 220 decreases and the negative pressure in the ink cartridge 220 exceeds the pressure of the check valve 228, the blade 232a is deformed (opened) inside the ink cartridge 220, and the external air Is taken into the ink cartridge 220.

  A check valve 228 in FIG. 38D includes a valve 232 and a spring 235 formed of rubber. When the negative pressure in the ink cartridge 220 exceeds the pressure of the check valve 228, the valve 232 descends (opens) against (presses) the spring 235 and external air is sucked into the ink cartridge 220. The

  On the other hand, an ink cartridge 220B shown in FIG. 38 (B) is obtained by disposing a porous member 242 in the first storage chamber 225a instead of providing the check valve 228 in the ink cartridge 220A of FIG. 38 (A). is there. The porous member 242 holds the ink in the ink cartridge 220B and prevents the ink from leaking out of the ink cartridge 220B when the ink cartridge 220B rolls.

  The case where the actuator 106 is mounted on the carriage or the carriage mounted on the carriage has been described above. However, the actuator 106 may be attached to an ink tank that is integrated with the carriage and attached to the ink jet recording apparatus together with the carriage. Furthermore, the actuator 106 may be mounted on an off-carriage type ink tank that supplies ink to the carriage via a tube or the like that is separate from the carriage. In addition, the actuator of the present invention may be attached to a portion corresponding to an ink cartridge of a member that is configured so that the recording head and the ink container are integrated and replaceable.

  The recording device control units 2000, 2002, 2004, 2006, their respective elements, and the control device 840c (see FIG. 10) can be configured by a computer system. Here, a program for realizing each of these elements in the computer system and a computer-readable recording medium 201 (see FIG. 5) in which the program is recorded are also subject to protection in this case.

  Further, when each of the above elements is realized by a program such as an OS that operates on a computer system, a program including various instructions for controlling the program such as the OS and a recording medium 202 that records the program are also included in the present invention. It is a protection target.

  Here, the recording media 201 and 202 include not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  As an example of liquid, glue, nail polish or the like can be used in addition to ink.

  As mentioned above, although this invention was demonstrated using several embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

FIG. 4 is a diagram showing details of an actuator 106. It is a figure which shows the periphery of the actuator 106 and its equivalent circuit. FIG. 5 is a diagram illustrating a relationship between ink density and ink resonance frequency detected by an actuator. It is a figure which shows the back electromotive force waveform of the actuator. FIG. 3 is a diagram illustrating a configuration of a recording apparatus control unit 2000 that detects a consumption state of a liquid in a liquid container 1 by an actuator 106 detecting a change in acoustic impedance and controls an ink jet recording apparatus based on the detection result. FIG. 10 is a block diagram illustrating a recording apparatus control unit 2002 according to another embodiment. FIG. 6 is a diagram illustrating still another embodiment of the recording apparatus control unit 2000 illustrated in FIG. 5. FIG. 8 is a diagram illustrating still another embodiment of the recording apparatus control unit 2004 illustrated in FIG. 7. 9 is a flowchart showing an operation procedure of the recording apparatus control unit 2006 shown in FIG. 2 is a diagram showing a circuit configuration of a measurement circuit unit 800. FIG. 6 is a diagram illustrating another example of the circuit configuration of the measurement circuit unit 800. FIG. It is a flowchart which shows the operation | movement procedure of the noise influence determination part 880. 2 is a diagram illustrating a circuit configuration of a detection circuit unit 1100. FIG. It is a figure which shows the detailed circuit structure of the liquid presence determination part 1000 shown in FIG. It is a figure which shows other embodiment of the actuator. FIG. 16 is a view showing a cross section of a part of the actuator shown in FIG. It is a figure which shows the cross section of the whole actuator 106 shown in FIG. FIG. 16 is a diagram showing a manufacturing method of the actuator 106 shown in FIG. 15. It is a figure which shows other embodiment of the ink cartridge of this invention. It is a figure which shows other embodiment of the through-hole 1c. It is a figure which shows other embodiment of the actuator 660. FIG. FIG. 38 is a diagram showing still another embodiment of the actuator 670. 2 is a perspective view showing a module body 100. FIG. FIG. 24 is an exploded view showing a configuration of the module body 100 shown in FIG. 23. It is a figure which shows other embodiment of the module body. FIG. 26 is an exploded view showing a configuration of the module body 400 shown in FIG. 25. It is a figure which shows other embodiment of the module body. FIG. 24 is a diagram illustrating an example of a cross section in which the module body 100 illustrated in FIG. 23 is attached to the ink container 1. It is a figure which shows other embodiment of the module body. It is a figure which shows other embodiment of the module body. FIG. 3 is a diagram showing an embodiment of an ink cartridge and an ink jet recording apparatus using the actuator shown in FIGS. 1 and 2. It is a figure which shows the detail of an inkjet recording device. FIG. 33 is a diagram showing another embodiment of the ink cartridge 180 shown in FIG. 32. FIG. 10 is a view showing still another embodiment of the ink cartridge 180. FIG. 10 is a view showing still another embodiment of the ink cartridge 180. FIG. 10 is a view showing still another embodiment of the ink cartridge 180. FIG. 37 is a view showing another embodiment of the ink cartridge 180 shown in FIG. FIG. 10 is a view showing still another embodiment of an ink cartridge using the module body 100.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Container 1a Bottom surface 1b Side wall 1c, 40a Through-hole 1d Side surface 1e, 1f Step part 1g, 1h Groove 2 Ink supply port 40, 41 Green sheet 42, 44 Conductive layer 44 'Connection part 47, 48 Spacer member 67 Plate material 68 Float 71 Adhesive layer 78, 80, 178 Substrate 73, 82, Piezoelectric vibration plate 74, 75 Ink absorber 76 Packing 77 Caulking hole 81 Recess 100, 400, 500, 700 Module body 101, 401, 501 Liquid container mounting portion 102 Base 104, 362 Lead wire 105, 405, 505 Piezoelectric device mounting part 106, 106b, 650, 660, 670 Actuator 108 Film 110 Plate 112, 412, 370 Through hole 113 Recessed part 114 Opening part 116 Column part 160 Piezoelectric layer 162 Cavity 164 Upper part Electrode 166 Lower electrode 168 Upper electrode terminal 170 Lower electrode terminal 172 Auxiliary electrode 174 Piezoelectric element 176 Vibration plate 180 Ink cartridge 181 Air supply port 182 Ink introduction port 183 Ink introduction port 184 Holder 185 Air introduction port 186 Head plate 187 Ink supply port 188 Nozzle plate 190 Nozzle 192 Wave barrier 194 Ink container 194a Bottom surface 194b Side wall 194c Top surface 212 Partition 213, 213a, 213b Storage chamber 214 Buffer 216, 216a, 216b Porous member 220 Ink cartridge 222 First partition 224 Second partition 225a First storage Chamber 225b Second storage chamber 227 Capillary passage 228 Check valve 230 Ink supply port 232 Valve 232a Blade 233 Vent hole 235 Spring 242 Porous member 250 Carriage 252 Recording head 25 Ink supply needle 256 Sub tank unit 258, 258 ′ Convex portion 260, 260 ′ Elastic wave generating means 262 Ink chamber 266 Membrane valve 270 Valve body 272 Ink cartridge 274 Container 274a Bottom surface 274b Side surface 276 Ink supply port 278 Concave portion 280, 280 ′ Gelation Material 282 Packing 284 Spring 286 Valve body 288 Semiconductor storage means 290 Container 290a Bottom surface 292, 294, 296 Ink chamber 298, 300, 302 Ink supply port 304, 306, 308 Gelling material 310, 312, 314 Recess 316 Plate material 318 Float 350 Mounting plate 360 Liquid container mounting portion 364 Mold portion 372 Sealing structure 402, 502 Base 403, 503 Cylindrical portion 404, 504 Lead wire 408, 508 Film 410, 510 Plate 413, 513 Recess 414, 514 Opening 600 Mold structure 606 Actuator 610 Circuit board 612 Terminal 800, 800A, 800B, 800C Measurement circuit part 810 NPN type transistor 812 PNP type transistor 816 Reference potential generation part 817, 818, 820, 828, 830, 832 Resistor 822, 826 Capacitor 824 High-pass filter 834, 840, 842, 844, 846 Terminal 836 Comparator 840c Control device 850, 850A, 850B, 850C Drive voltage generator 860 Amplifier 880 Noise influence determination unit 900, 902 Digital circuit unit 910, 918 Flip-flops 912, 920 Counters 914, 916 NAND gates 1000, 1002 Liquid presence / absence determination unit 1010 Liquid consumption state correction unit 1011 Upper limit value register 10 2 Lower limit register 1014, 1016 Comparison unit 1018 AND gate 1020, 1022 Terminal 1100, 1102, 1104 Detection circuit unit 1200, 1202, 1210 Liquid consumption state detection unit 1300 Head unit 1400 Control unit 1402 Recording device operation control unit 1404 Presentation processing unit 1406 Print Operation Control Unit 1408 Ink Replenishment Processing Unit 1410 Cartridge Replacement Processing Unit 1412 Print Data Storage Processing Unit 1414 Print Data Storage Unit 1416 Display 1418 Speaker 1420 Print Operation Unit 1422 Ink Replenishment Device 1424 Cartridge Replacement Device 1432 Cleaning Drive Unit 1434 Pump 1436 Cleaning Unit 1440 head drive unit 1442 cleaning control unit 1444 information storage control circuit unit 1450 liquid discharge counter 1452 liquid consumption Correction unit 1500,1502,1506 control circuit unit 2000,2002,2004,2006 recording apparatus control unit

Claims (1)

A liquid container, and a liquid consumption main body part that consumes the liquid connected to the liquid container and contained in the liquid container,
The liquid container is a liquid consuming device that is mounted on a carriage of the liquid consuming main body and is configured to allow liquid to communicate with a recording head portion of the liquid consuming main body.
The liquid container includes a wall portion that defines a storage space for storing a liquid, a vibration portion that is at least partially exposed to the storage space for storing the liquid and can vibrate with respect to the storage space, and the vibration A piezoelectric element disposed on the surface of the portion opposite to the liquid storage space, and a digital signal generation circuit portion,
The piezoelectric element can vibrate the vibration part based on the application of the drive signal and generates a back electromotive force signal by the residual vibration of the vibration part after the vibration by the application of the drive signal.
The digital signal generation circuit unit is configured to generate a digital signal that can specify the frequency of the counter electromotive force signal based on the counter electromotive force signal and output the digital signal to the outside of the liquid container,
The liquid consumption main body part is provided with a detection circuit part for detecting a liquid consumption state,
The detection circuit unit is connected to the digital signal generation circuit unit in the liquid container, receives the digital signal output from the digital signal generation circuit unit, and generates a back electromotive force signal based on the digital signal. The frequency is measured, and the liquid consumption state of the liquid storage space is detected based on the frequency,
Further, the digital signal generation circuit unit compares whether the back electromotive force signal is high or low with respect to a predetermined reference voltage, and the comparison result is substantially the same as the frequency of the back electromotive force signal. It is designed to output as the digital signal as a rectangular pulse signal that repeats at a frequency,
The detection circuit unit has a clock counter for measuring a time during which the rectangular pulse signal vibrates a predetermined number of times, and based on the time measured by the clock counter, the frequency of the counter electromotive force signal To measure
The detection circuit unit further includes a noise influence determination unit that determines the influence of noise on the back electromotive force signal,
The liquid consumption device according to claim 1, wherein the noise influence determination unit observes an output of the digital signal generation circuit unit before a drive voltage signal is applied to the piezoelectric element.

Images