JP2010131776A - Liquid jetting apparatus, liquid jetting apparatus body, liquid container, and method of detecting malfunction of liquid detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique whereby malfunction of a liquid residual quantity detector can be accurately detected by a simple method. <P>SOLUTION: The liquid jetting apparatus includes a liquid storage part which stores a liquid jetted from the liquid jetting apparatus, and the liquid detector which detects a residual quantity of the liquid stored in the liquid storage part. The liquid detector includes a liquid detection chamber which communicates with the liquid storage part, and a detection signal generating part which generates a detection signal with a signal waveform according to a pressure in the liquid detection chamber. The liquid jetting apparatus further includes a malfunction detecting part which detects malfunction of the liquid detector by comparing the detection signal when a flow volume of the liquid flowing in the liquid detection chamber is 0 with the detection signal when the flow volume of the liquid flowing in the liquid detection chamber is not 0, at a time point when the residual quantity of the liquid for each case is the same. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to detection of malfunction of a liquid detection device.

  An ink jet printer, which is an example of a liquid ejecting apparatus, is mounted with an ink cartridge including an ink pack. In recent years, some ink cartridges are provided with a device for detecting the remaining amount of ink. As a method for detecting a malfunction of a device for detecting the remaining amount of ink (hereinafter also referred to as an ink remaining amount detecting device), a method disclosed in the following patent document is known ( For example, see Patent Document 1 or 2.)

Japanese Patent Laid-Open No. 2004-351871 JP 2007-244771 A

  However, in the conventional technique, it may be difficult to accurately detect the malfunction of the ink remaining amount detection device. Such a problem is not limited to an ink jet printing apparatus, but is a problem common to all liquid ejecting apparatuses.

  An object of this invention is to provide the technique which can detect the malfunction of a liquid residual amount detection apparatus accurately with a simple method.

  In order to solve at least a part of the problems described above, the present invention can take the following forms or application examples.

[Application Example 1]
A liquid ejecting apparatus,
A liquid container that contains the liquid ejected from the liquid ejecting apparatus;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid ejecting apparatus further includes:
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0;
A liquid ejecting apparatus comprising a malfunction detection unit that detects malfunction of the liquid detection apparatus by comparing the remaining amounts of liquid at the same time.
According to the liquid ejecting apparatus of Application Example 1, the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0 and the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 Since the amounts are compared at the same time, the malfunction of the liquid detection device can be accurately detected by a simple method.

[Application Example 2]
The liquid ejecting apparatus according to Application Example 1,
The malfunction detection unit is
Detecting the pressure value in the liquid detection chamber from the signal waveform of the detection signal;
The pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is 0,
When the flow rate of the liquid flowing through the liquid detection chamber is larger than the pressure value in the liquid detection chamber detected when the flow rate is not zero,
A liquid ejecting apparatus that determines that the operation of the liquid detecting apparatus is normal.
When the operation of the liquid detection device is not normal, the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is 0, the flow rate of the liquid flowing through the liquid detection chamber is not 0. In some cases, the pressure value may be smaller than the pressure value detected in the liquid detection chamber. Therefore, according to the liquid ejecting apparatus of Application Example 2, it is possible to accurately detect an operation failure of the liquid detection apparatus with a simple method.

[Application Example 3]
The liquid ejecting apparatus according to Application Example 1 or 2,
The malfunction detection unit is
Detecting the pressure value in the liquid detection chamber from the signal waveform of the detection signal;
When the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is not 0 becomes a predetermined threshold value or less,
When the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is 0 is larger than the predetermined threshold,
A liquid ejecting apparatus that determines that the operation of the liquid detecting apparatus is normal.
According to the liquid ejecting apparatus of the application example 3, when the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is not zero, the operation of the liquid detection device is performed. Whether it is normal can be determined.

[Application Example 4]
The liquid ejecting apparatus according to any one of Application Examples 1 to 3,
The liquid ejecting apparatus includes a case where the liquid ejecting apparatus ejects the liquid when the flow rate of the liquid flowing through the liquid detection chamber is not zero.

[Application Example 5]
The liquid ejecting apparatus according to any one of Application Examples 1 to 4, further comprising:
A suction pump for sucking the liquid in the liquid container;
The liquid ejecting apparatus including a case where the flow rate of the liquid flowing through the liquid detection chamber is not 0, the suction pump sucking the liquid in the liquid storage unit.

[Application Example 6]
The liquid ejecting apparatus according to any one of Application Examples 1 to 5, further comprising:
A liquid ejecting section for ejecting the liquid in the liquid containing section;
A liquid suction part for sucking the liquid in the fluid storage part through the liquid ejection part,
The liquid ejecting apparatus including a case where the liquid suction unit sucks the liquid in the liquid ejecting unit when the flow rate of the liquid flowing through the liquid detection chamber is not zero.

[Application Example 7]
The liquid ejecting apparatus according to any one of Application Examples 1 to 6,
The liquid detection chamber is
A flexible portion formed on one surface of the liquid detection chamber and deformable according to the pressure in the liquid detection chamber;
A moving member housed in the liquid detection chamber and movable in accordance with deformation of the flexible portion;
An urging member that urges the moving member in a direction opposite to a moving direction of the moving member due to a decrease in the pressure;
Including
The said detection signal production | generation part is a liquid ejecting apparatus which produces | generates the said detection signal which has a signal waveform according to the position of the said moving member.
According to the liquid ejecting apparatus of Application Example 7, a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber can be generated with a simple configuration.

[Application Example 8]
The liquid ejecting apparatus according to Application Example 7,
The detection signal generator is
A piezoelectric device that has a concave portion on a surface facing the moving member, applies vibration to the liquid filled in the concave portion, and generates the detection signal having a signal waveform corresponding to a state of free vibration generated along with the vibration. A liquid ejecting apparatus which is a detection unit.
According to the liquid ejecting apparatus of Application Example 8, it is possible to generate a detection signal having a signal waveform corresponding to the position of the moving member.

[Application Example 9]
A liquid ejecting apparatus main body for ejecting liquid supplied from a liquid storage container,
The liquid container is
A liquid container for containing the liquid;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid ejecting apparatus main body is
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
An operation failure detection unit that detects an operation failure of the liquid detection device by comparing the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of the liquid is provided. Liquid ejector body.

[Application Example 10]
A liquid container,
A liquid container that contains the liquid ejected from the liquid ejecting apparatus main body;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid container further includes:
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
An operation failure detection unit that detects an operation failure of the liquid detection device by comparing the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of the liquid is provided. Liquid container.

[Application Example 11]
A method for detecting a malfunction of a liquid detection device including a liquid detection chamber communicating with a liquid storage unit,
The pressure in the liquid detection chamber when the flow rate of the liquid flowing through the liquid detection chamber is 0;
The malfunction of the liquid detection device is detected by comparing the pressure in the liquid detection chamber when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of liquid in the liquid storage unit at the same time. how to.
According to Application Examples 9 to 11, the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0 and the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 are used as the remaining amount of the liquid. Are compared at the same time point, it is possible to accurately detect the malfunction of the liquid detection device by a simple method.

  Note that the present invention can be realized in various modes. For example, a malfunction detection method and detection apparatus for a liquid detection apparatus, a malfunction detection system for the liquid detection apparatus, an integrated circuit for realizing the function of the method or apparatus, a computer program, a recording medium on which the computer program is recorded, etc. Can be realized.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Example:
B. Variation:

A. Example:
FIG. 1 is an explanatory diagram showing a configuration of a liquid ejecting apparatus as an embodiment of the present invention. The liquid ejecting apparatus includes a liquid container 1 and a liquid ejecting apparatus body 2. The liquid storage container 1 is a so-called ink cartridge, and includes a case 5, a liquid storage portion 7, a liquid supply port 9, and a liquid detection device 11. The case 5 is a box-shaped housing and defines the internal space 3. An air release hole 13 is formed through the partition wall 5a on one end side among the six partition walls defining the internal space 3. When the internal space 3 is not a sealed space due to the configuration of the case 5, the air communication hole 13 can be omitted.

  The liquid storage unit 7 is a so-called ink pack, and stores the liquid supplied to the liquid ejecting apparatus main body 2 (FIG. 1). At least a part of the liquid storage portion 7 is formed of a flexible member. The liquid supply port 9 is connected to the liquid ejecting apparatus main body 2 and is a supply port for supplying the liquid accommodated in the liquid accommodating portion 7 to the liquid ejecting apparatus main body 2. The liquid detection device 11 is a device for outputting a signal corresponding to the remaining amount of liquid in the liquid storage unit 7. The liquid container 1 will be described in detail later.

  The liquid ejecting apparatus main body 2 is a so-called ink jet printer main body, and includes a liquid introducing unit 40, a liquid ejecting unit 46, a cap 47, a suction pump 48, a waste ink absorbing material 49, a diaphragm pump 42, and a remaining amount determination. Unit 60 and operation failure detection unit 70. The liquid introduction unit 40 is configured by a known liquid supply needle (for example, an ink supply needle) that is inserted into the liquid supply port 9. Hereinafter, the liquid introduction part 40 is also referred to as a “liquid supply needle 40”. The liquid supply needle 40 has a liquid inflow hole 40a and a liquid channel 40b communicating with the liquid inflow hole 40a. The liquid supply needle 40 is connected to the liquid supply port 9 provided in the liquid storage container 1.

  The liquid ejecting unit 46 is a device that consumes the liquid stored in the liquid storing unit 7, and is configured by, for example, a known ink jet head. Hereinafter, the liquid ejecting unit 46 is also referred to as a “recording head 46”. The cap 47 covers the nozzle surface of the recording head 46 when the recording head 46 is in the home position. When the nozzle of the recording head 46 is clogged, the suction pump 48 forcibly sucks ink from the nozzle through the cap 47 to eliminate the nozzle clogging. The waste ink absorbing material 49 absorbs waste ink from the suction pump 48. The remaining amount determination unit 60 is connected to the liquid detection device 11 and determines the amount of liquid in the liquid storage unit 7 based on the output signal of the liquid detection device 11. The malfunction detection unit 70 is connected to the liquid detection device 11 and detects malfunction of the liquid detection device 11 based on an output signal of the liquid detection device 11. The remaining amount determination unit 60, the malfunction detection unit 70, and the liquid detection device 11 will be described in detail later.

  The diaphragm pump 42 is provided between the liquid supply needle 40 and the recording head 46, and is a device for supplying the liquid from the liquid supply needle 40 to the recording head 46. The diaphragm pump 42 delivers liquid by releasing an external force after applying an external force in a direction in which the volume increases from a state where the diaphragm pump 42 is biased in a direction in which the volume decreases.

  The diaphragm pump 42 includes a decompression chamber 42a, a diaphragm 42b, a diaphragm chamber 42c, and a compression spring 42d. The diaphragm chamber 42c is formed by dividing the decompression chamber 42a by the diaphragm 42b. The compression spring 42d urges the diaphragm 42b in a direction that reduces the volume of the diaphragm chamber 42c. The pressure generated by the compression spring 42d that urges the diaphragm 42b is equal to or greater than the pressure required to prevent the liquid supplied to the recording head 46 from being insufficient.

  An air release valve 51, a pressure detector 52 for the air flow path, and a pressure reduction pump 53 are connected to the pressure reducing chamber 42 a through the air flow path 50. The liquid inlet 42 i of the diaphragm chamber 42 c is connected to the liquid supply needle 40 via the on-off valve 41. The liquid outlet 42 o of the diaphragm chamber 42 c is connected to the recording head 46 via a check valve 43, a liquid supply channel 44, and a pressure adjustment valve (self-sealing valve) 45. The on-off valve 41 may be a check valve that allows the flow of liquid from the liquid storage portion 7 to the diaphragm chamber 42c.

2 to 4 are explanatory views showing the operation of the diaphragm pump 42. FIG. The diaphragm pump 42 operates as follows.
(I) As shown in FIG. 2, the pressure reducing pump 53 is driven with the flow path opening / closing valve 41 opened, and air (A) is extracted from the pressure reducing chamber 42 a as indicated by an arrow A. As a result, the inside of the decompression chamber 42a is decompressed, and the diaphragm 42b expands against the compression spring 42d. Then, as indicated by the arrow F, the liquid (F) is sucked from the liquid storage portion 7 into the diaphragm chamber 42c.

  (Ii) Thereafter, as shown in FIG. 3, when the decompression pump 53 is stopped and the atmosphere release valve 51 is opened, as shown by an arrow A, air (A) flows into the decompression chamber 42a and the inside of the decompression chamber 42a It becomes atmospheric pressure. Then, the diaphragm 42b is contracted by the compression spring 42d, the inside of the liquid supply passage 44 and the passage to the check valve 14 in the liquid container 1 are pressurized, and the liquid is appropriately supplied to the recording head 46. Is done.

  (Iii) Thereafter, as shown in FIG. 4, when the liquid is consumed by the recording head 46 and the liquid in the diaphragm chamber 42c runs out, the operations (i) and (ii) are repeated.

  FIG. 5 is an explanatory diagram showing the configuration of the liquid container as an embodiment of the present invention. The liquid storage container 1 includes a case 5, a liquid storage unit 7, a liquid supply port 9, and a liquid detection device 11.

  The liquid storage portion 7 is a so-called ink pack, and is formed by joining a cylindrical discharge port 7a to one end side of the bag body 7b. The discharge port 7 a is connected to the liquid inlet 11 a of the liquid detection device 11. The bag body 7b is formed, for example, by bonding the peripheral portions of two aluminum laminated multilayer films to each other. The aluminum laminate multilayer film is formed by laminating an aluminum layer on a resin film layer. By adopting an aluminum laminate multilayer film as the bag body 7b, high gas barrier properties can be ensured.

  The liquid storage unit 7 and the liquid detection device 11 are connected to each other by fitting and connecting the liquid inlet 11a of the liquid detection device 11 to the discharge port 7a of the liquid storage unit 7. That is, by releasing the fitting between the discharge port 7a and the liquid inflow port 11a, they can be separated from each other. The liquid container 7 is filled with ink that has been adjusted to a high degree of deaeration in advance before connecting the liquid detection device 11.

  The liquid supply port 9 is formed through the partition wall 5 a on one end side of the case 5. When the liquid storage container (ink cartridge) 1 is attached to the liquid ejecting apparatus main body 2 (FIG. 1), the liquid supply needle 40 of the liquid ejecting apparatus main body 2 is inserted into the liquid supply port 9. Therefore, the liquid in the liquid storage unit 7 can be supplied to the liquid ejecting apparatus body 2.

  The liquid detection device 11 is a device that outputs a signal corresponding to the amount of liquid in the liquid storage unit 7. The liquid detection device 11 includes a detection device case 19, a flexible portion 23, a vibration detection portion 25, a moving member 27, and an urging member 29. The inside of the detection device case 19 is a concave space 19a. The vibration detector 25 is provided at the bottom of the concave space 19a. The detection device case 19 is provided with a liquid inflow port 11 a connected to the discharge port 7 a of the liquid container 7 and a liquid outflow port 11 b connected to the liquid supply port 9. The recessed space 19a, the liquid inlet 11a, and the liquid outlet 11b communicate with each other. Although illustration is omitted, a check valve is provided at the liquid inlet 11 a, and the flow of the liquid that attempts to flow backward from the liquid detection chamber 21 to the liquid storage unit 7 is blocked.

  The flexible portion 23 seals the opening on the upper surface of the concave space 19a, and the liquid detection chamber 21 is formed by the flexible portion 23 and the concave space 19a. The flexible portion 23 is formed of a film-like member and can be deformed according to the pressure in the liquid detection chamber 21. That is, the flexible portion 23 functions as a diaphragm that applies displacement to the moving member 27 in accordance with the pressure of the liquid supplied to the liquid detection chamber 21. Below, the flexible part 23 is also called "flexible film 23". In order to detect a minute pressure change of the liquid and improve the detection accuracy, the flexible film 23 is preferably provided with sufficient flexibility.

  The moving member 27 is provided at a position facing the vibration detection unit 25 on the inner surface of the flexible film 23. The moving member 27 is movable according to the deformation of the flexible film 23. That is, the moving member 27 moves according to the pressure in the liquid detection chamber 21. The moving member 27 is not fixed to the flexible film 23 and is simply in contact with the inner surface of the flexible film 23.

  The urging member 29 is provided in a compressed state between the moving member 27 and the bottom portion 19b of the concave space 19a. The urging member 29 urges the moving member 27 and the flexible film 23 in the direction in which the volume of the liquid detection chamber 21 increases. As the urging member 29, for example, a pressing spring (compression spring) can be employed. Hereinafter, the biasing member 29 is also referred to as a “compression spring 29”.

  The vibration detector 25 is provided at the bottom of the concave space 19a. The vibration detection unit 25 generates a signal corresponding to the distance L from the moving member 27 to the bottom of the concave space 19a. The distance L from the moving member 27 to the bottom of the concave space 19a has a correlation with the pressure in the liquid detection chamber 21, as will be described later. That is, the signal generated by the vibration detection unit 25 has a signal waveform corresponding to the pressure in the liquid detection chamber 21. The pressure in the liquid detection chamber 21 is also correlated with the amount of liquid in the liquid storage unit 7. Therefore, the signal generated by the vibration detection unit 25 has a signal waveform corresponding to the amount of liquid in the liquid storage unit 7.

  The vibration detection unit 25 includes a support base 31, a liquid guide path 33, and a piezoelectric vibration element 35. The liquid guide path 33 communicates with the liquid detection chamber 21, and the guide path 33 is filled with liquid. The piezoelectric vibration element 35 has a diaphragm, and this diaphragm is in contact with the liquid in the liquid guide path 33. When a drive signal is supplied to the piezoelectric vibration element 35, the piezoelectric vibration element 35 is excited as an actuator for a predetermined time, and the diaphragm starts free vibration. Back electromotive force is generated in the piezoelectric vibration element 35 by free vibration of the diaphragm (hereinafter, also referred to as “residual vibration”). The piezoelectric vibration element 35 outputs this counter electromotive force as an output signal.

  As described above, since the diaphragm of the piezoelectric vibration element 35 is in contact with the liquid in the liquid induction path 33, the amplitude and frequency of the counter electromotive force generated in the piezoelectric vibration element 35 are the liquid in the liquid induction path 33. It fluctuates according to the state. That is, the greater the distance L from the support base 31 to the moving member 27, the easier the liquid in the liquid guiding path 33 vibrates, and thus the amplitude of the output signal of the piezoelectric vibration element 35 increases. Further, the greater the distance L, the greater the frequency of the output signal of the piezoelectric vibration element 35.

  On the other hand, as the distance L from the support base 31 to the moving member 27 becomes smaller, the liquid in the liquid guiding path 33 is less likely to vibrate, so the amplitude of the output signal of the piezoelectric vibration element 35 becomes smaller. When the distance L from the support base 31 to the moving member 27 becomes 0, the liquid guiding path 33 is closed by the moving member 27, so that the vibration of the liquid in the liquid guiding path 33 is immediately attenuated, and the piezoelectric The amplitude of the output signal of the vibration element 35 is extremely small. Further, as the distance L becomes smaller, the frequency of the output signal of the piezoelectric vibration element 35 becomes smaller.

  From the above, it can be said that there is a correlation between the amplitude and frequency of the output signal of the piezoelectric vibration element 35 and the distance L from the support base 31 to the moving member 27. As will be described below, there is a correlation between the distance L and the pressure in the liquid detection chamber 21, and between the pressure in the liquid detection chamber 21 and the amount of liquid in the liquid storage unit 7. Are correlated. The remaining amount determination unit 60 (FIG. 1) calculates the pressure in the liquid detection chamber 21 from one or both of the amplitude and the frequency of the output signal of the piezoelectric vibration element 35, and the pressure in the liquid detection chamber 21 and the liquid Based on the liquid flow state (flow rate) in the detection chamber 21, the remaining amount of liquid in the liquid storage unit 7 is determined. Hereinafter, a process in which the liquid in the liquid storage unit 7 is consumed will be described with reference to FIGS.

  First, the pressure acting in the direction in which the moving member 27 is moved away from the support base 31, that is, the direction in which the distance L is increased is defined as positive. The biasing force that biases the compression spring 29 toward the moving member 27 is Ps. Further, the pressure generated by the elasticity of the flexible film forming the liquid storage portion 7 is defined as Pp. The amount of pressure drop due to the flow rate is Pr.

  Here, the urging force Ps changes depending on the position of the moving member 27. In the following description, it is assumed that Ps = + 3.0 kPa, for example. In addition, the reaction force of the flexible film 23 that is a diaphragm actually acts, but is ignored here.

  As shown in FIG. 5, a case where there is a sufficient liquid in the liquid storage portion 7 and there is no liquid flow will be considered. When there is sufficient liquid inside, the liquid storage unit 7 pushes out the liquid and increases the pressure in the liquid detection chamber 21. Therefore, the pressure Pp due to the elasticity of the flexible film forming the liquid storage portion 7 is, for example, Pp = + 0.5 kPa. Also, since there is no liquid flow, there is no pressure drop Pr due to the flow velocity. Therefore, Pr = 0 kPa. At this time, the total pressure Ptotal in the liquid detection chamber 21 is Ptotal = Ps + Pp + Pr = + 3.5 kPa. Therefore, the moving member 27 is pushed up by the compression spring 29.

  FIG. 6 is an explanatory diagram showing the liquid container 1 when there is sufficient liquid in the liquid container 7 and there is a liquid flow in the liquid detection chamber 21. Similarly to the case of FIG. 5, the pressure Pp due to the elasticity of the flexible film forming the liquid storage portion 7 is, for example, Pp = + 0.5 kPa. Further, when there is a liquid flow in the liquid detection chamber 21, the pressure drop amount Pr due to the flow velocity is, for example, Pr = −0.5 kPa. At this time, the total pressure Ptotal in the liquid detection chamber 21 is Ptotal = Ps + Pp + Pr = + 3.0 kPa. Therefore, the moving member 27 is pushed up by the compression spring 29. However, since the distance L is correlated with the total pressure Ptotal (= Ps + Pp + Pr) in the liquid detection chamber 21, the distance L in the case of FIG. 6 is smaller than the distance L in the case of FIG. Yes.

  FIG. 7 is an explanatory diagram showing the liquid storage container 1 when the liquid in the liquid storage unit 7 decreases and approaches the ink end state (hereinafter also referred to as “ink near end state”). Here, the ink end state refers to a state in which the liquid in the liquid storage portion 7 decreases and is almost exhausted, and the liquid storage container 1 needs to be replaced. Further, the ink near end state refers to a state in which liquid remains more than in the ink end state, but the liquid is almost exhausted.

  When the liquid in the liquid container 7 is reduced and the liquid container 1 is in an ink near end state, the flexible film forming the liquid container 7 tends to spread. As a result, the liquid storage unit 7 tries to draw back the liquid in the liquid detection chamber 21. Therefore, the pressure Pp due to the elasticity of the flexible film forming the liquid storage portion 7 is a negative pressure, for example, Pp = −2 kPa.

  When there is a liquid flow in the liquid detection chamber 21, since the flow path is narrower than in the case of FIG. 6, the pressure drop amount Pr due to the flow velocity further increases, for example, Pr = −1.0 kPa. At this time, the total pressure in the liquid detection chamber 21 is Ps + Pp + Pr = 0 kPa. In other words, the urging force Ps = + 3.0 kPa by the compression spring 29 and the other pressure (Pp + Pr = −3.0 kPa) are balanced. In this state, the moving member 27 is almost in contact with the support base 31.

  On the other hand, Pr = 0 kPa when there is no liquid flow in the ink near-end state shown in FIG. Accordingly, the total pressure Ptotal in the liquid detection chamber 21 is Ptotal = Ps + Pp + Pr = + 1.0 kPa. That is, when there is no liquid flow in the ink near-end state, the distance L between the moving member 27 and the support base 31 is slightly larger than when there is a flow.

  FIG. 8 is an explanatory diagram showing the liquid container 1 when the liquid in the liquid container 7 is further reduced and the ink end state is reached. When the liquid in the liquid storage portion 7 is further reduced and the liquid storage container 1 is in the ink end state, the flexible film forming the liquid storage portion 7 tends to further spread. Therefore, the pressure Pp due to the elasticity of the flexible film forming the liquid storage portion 7 is a negative pressure, for example, Pp = −3.0 kPa.

  When there is a liquid flow in the liquid detection chamber 21, since the flow path is further narrower than in the case of FIG. 7, the pressure drop amount Pr due to the flow velocity is further increased, for example, Pr = −2.0 kPa. . At this time, the total pressure Ptotal in the liquid detection chamber 21 is Ptotal = Ps + Pp + Pr = −2.0 kPa. That is, the moving member 27 is in contact with the support base 31.

  On the other hand, in the ink end state shown in FIG. 8, if there is no liquid flow, Pr = 0 kPa. Accordingly, the total pressure Ptotal in the liquid detection chamber 21 is Ptotal = Ps + Pp + Pr = 0.0 kPa. That is, even when there is no liquid flow in the ink end state, the moving member 27 is almost in contact with the support base 31.

  7 and 8, since the length of the compression spring 29 is almost the same, even if the urging force Ps of the compression spring 29 is assumed to be a constant value, an error in the remaining amount detection due to this can be ignored. Degree.

  FIG. 9 is a graph showing the relationship between the remaining amount of liquid in the liquid storage unit 7 and the negative pressure in the liquid detection chamber 21. The left vertical axis in FIG. 9 indicates the negative pressure (Pp + Pr) generated in the liquid detection chamber 21, and the right vertical axis indicates the total pressure Ptotal (= Ps + Pp + Pr). Graph G1 shows the case where there is no liquid (ink) flow (when the flow rate is 0), and graph G2 shows the case where there is a liquid flow (when the flow rate is not 0). According to FIG. 9, the absolute value of the negative pressure in the liquid detection chamber 21 is the same as that in the liquid container 7, both when there is no liquid flow (graph G1) and when there is a liquid flow (graph G2). It can be understood that the amount of liquid increases as the remaining amount of liquid decreases. That is, the distance L in FIGS. 5 to 8 becomes smaller as the remaining amount of the liquid in the liquid container 7 becomes smaller. According to FIG. 9, the absolute value of the negative pressure in the liquid detection chamber 21 when there is a liquid flow (graph G2) is the absolute value of the negative pressure in the liquid detection chamber 21 when there is no liquid flow (graph G1). It can be understood that it is larger than the absolute value. This is because when there is a liquid flow, a pressure drop Pr due to the flow velocity occurs.

  Here, since the urging force Ps is Ps = + 3.0 kPa, when the absolute value of the negative pressure (Pp + Pr) is larger than 3.0 kPa, the moving member 27 is substantially in contact with the support base 31 and the distance L Becomes almost zero. In the case where there is no liquid flow (graph G1), the absolute value of the negative pressure coincides with 3.0 kPa when the remaining amount of liquid in the liquid container 7 becomes 5 g (ink end state). On the other hand, when there is a liquid flow (graph G2), the absolute value of the negative pressure coincides with 3.0 kPa when the remaining amount of liquid in the liquid container 7 reaches 15 g (ink near end state). is there.

  The remaining amount determination unit 60 determines the remaining amount of liquid as follows by using the relationship between the remaining amount of liquid in the liquid storage unit 7 and the negative pressure described above. The vibration detection unit 25 outputs a signal having an amplitude or a frequency according to the distance L from the moving member 27 to the support base 31. The remaining amount determination unit 60 (FIG. 1) obtains the distance L from the moving member 27 to the support base 31 based on one or both of the amplitude and frequency of the output signal of the vibration detection unit 25. Further, since there is a correlation between the distance L and the negative pressure in the liquid detection chamber 21, the remaining amount determination unit 60 determines the negative in the liquid detection chamber 21 based on the output signal of the vibration detection unit 25. The pressure (Pp + Pr) is determined.

  Next, the remaining amount determination unit 60 sets the threshold value Pth of the absolute value of negative pressure to 3.0 kPa. The remaining amount determination unit 60 then flows the liquid into the liquid detection chamber 21 when the absolute value of the negative pressure obtained based on the output signal of the vibration detection unit 25 matches the threshold value Pth (3.0 kPa). If there is, it is determined that the remaining amount of the liquid in the liquid storage unit 7 is 15 g (that is, the ink near end state). When the remaining amount determination unit 60 determines that the liquid container 1 is in the ink near-end state, the remaining amount determination unit 60 turns on a lamp indicating the ink near-end state, or indicates that the monitor (not shown) is in the ink near-end state. This is displayed to inform the user of the liquid ejecting apparatus that the ink near-end state has been reached.

  On the other hand, when the absolute value of the negative pressure obtained based on the output signal of the vibration detection unit 25 matches the threshold value Pth (3.0 kPa), the remaining amount determination unit 60 flows the liquid into the liquid detection chamber 21. If there is no ink, it is determined that the remaining amount of the liquid in the liquid container 7 is 5 g (that is, the ink end state). When the remaining amount determination unit 60 determines that the liquid container 1 is in the ink end state, the remaining amount determination unit 60 turns on a lamp indicating the ink end state, or informs a monitor (not shown) that the ink end state is in effect. This is displayed to inform the user of the liquid ejecting apparatus that the ink is in an end state.

  Note that if the absolute value of the negative pressure in the liquid detection chamber 21 is larger than a threshold value Pth2 (for example, 5.0 kPa), it may be difficult to suck the liquid from the liquid storage unit 7. Hereinafter, this threshold value Pth2 is also referred to as a suction limit threshold value Pth2. Therefore, the remaining amount of liquid detected as the ink end state is set to the remaining amount of liquid at the time when the absolute value of the negative pressure in the case where there is a liquid flow (G2) matches the suction limit threshold value Pth2 (5.0 kPa). It is preferable to do. Then, the threshold value Pth is preferably set to a value (3.0 kPa) that is positive from the suction limit threshold value Pth2 by the pressure drop (2.0 kPa) due to the flow velocity. By setting the threshold value Pth in this way, the ink end state can be detected when there is no liquid flow in the liquid detection chamber 21 (G1).

  Next, the malfunction detection unit 70 will be described. When the liquid detection device 11 is operating normally, the pressure value detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0, as shown in FIG. It is on the positive side of the pressure value detected when the flow rate of the liquid flowing through is not zero. However, when a malfunction (for example, a malfunction of the vibration detection unit 25 or the compression spring 29) occurs in the liquid detection device 11, the detected pressure value curve may be different from the curve shown in FIG. For example, the pressure value detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0 is equal to the pressure value detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is not 0, or The pressure value detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is zero is on the negative side of the pressure value detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is not zero. There is a case.

  Here, the malfunction detection unit 70 detects the output signal of the vibration detection unit 25 when the flow rate of the liquid flowing through the liquid detection chamber 21 is zero, and the vibration detection when the flow rate of the liquid flowing through the liquid detection chamber 21 is not zero. The malfunction of the liquid detection device 11 is detected by comparing the output signal of the unit 25. For this comparison, it is preferable to use the pressure values detected at the time when the remaining amount of liquid in the liquid container 7 is substantially the same.

  Specifically, similarly to the remaining amount determination unit 60, the malfunction detection unit 70 determines the negative pressure (Pp + Pr) in the liquid detection chamber 21 based on one or both of the amplitude and frequency of the output signal of the vibration detection unit 25. ) Then, the malfunction detection unit 70 detects that the negative pressure (P1 in FIG. 9) detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0 causes the flow rate of the liquid flowing through the liquid detection chamber 21 to be 0. If the negative pressure detected in the case (P2 in FIG. 9) is greater than the negative pressure, it is determined that the liquid detection device 11 is operating normally.

  Further, the malfunction detection unit 70 detects the time point when the negative pressure (P3 in FIG. 9) detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is not 0 coincides with the threshold value Pth (that is, the ink near-end state is detected). When the negative pressure (P4 in FIG. 9) detected when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0 at the positive side of the threshold value Pth, the liquid detection device 11 is normal. Is determined to be operating.

  When the malfunction detection unit 70 detects the malfunction of the liquid detection device 11, the malfunction detection unit 70 turns on a lamp indicating the malfunction of the liquid detection device 11 or the monitor (not shown) causes the malfunction of the liquid detection device 11. May be displayed to notify the user of the liquid ejecting apparatus that the liquid detecting apparatus 11 is malfunctioning.

  FIG. 10 is an explanatory diagram in which a graph (G3) during maintenance of the recording head 46 is added to FIG. The maintenance of the recording head 46 means that the suction pump 48 (FIG. 1) forcibly sucks ink from the nozzles of the recording head 46 through the cap 47 to eliminate nozzle clogging. At the time of maintenance of the recording head 46, the flow rate of the liquid is further increased, so that the pressure decrease amount Pr due to the flow velocity is further increased, and the absolute value of the negative pressure is further increased. Therefore, during maintenance (graph G3) where the liquid flow rate is higher, the absolute value of the negative pressure coincides with 3.0 kPa when the remaining amount of liquid in the liquid container 7 becomes 35 g. Therefore, the remaining amount determination unit 60 determines the flow rate of the liquid in the liquid detection chamber 21 when the absolute value of the negative pressure obtained based on the output signal of the vibration detection unit 25 matches the threshold value Pth (3.0 kPa). When the maintenance time is more, it is determined that the remaining amount of the liquid in the liquid storage unit 7 is 35 g.

  When the absolute value of the negative pressure coincides with the threshold value Pth (3.0 kPa), the moving member 27 comes into contact with the support base 31 and the liquid guide path 33 is closed, the amplitude of the output signal of the vibration detection unit 25 Is significantly reduced. Therefore, the remaining amount determination unit 60 can easily detect that the absolute value of the negative pressure matches the threshold value Pth (3.0 kPa).

  Further, as a case where a constant flow of the liquid is generated in the liquid detection chamber 21, for example, the diaphragm pump 42 may suck the liquid in the liquid storage unit 7, but in addition to this, the liquid ejecting apparatus main body When the liquid 2 ejects liquid (that is, when the ink jet printer performs printing by the print head) or when the recording head 46 is maintained, a constant flow of the liquid is generated in the liquid detection chamber 21. In addition, a liquid ejecting apparatus may be configured.

  The remaining amount determination unit 60 and the malfunction detection unit 70 use information indicating whether or not there is a constant flow of liquid in the liquid detection chamber 21 (that is, information regarding the flow rate of the liquid in the liquid detection chamber 21). It can be detected by receiving a signal indicating the operation status of the apparatus main body 2 (for example, the amount of liquid ejected per unit time or whether maintenance is performed). Alternatively, a flow sensor may be provided in the liquid detection chamber 21.

  As described above, according to the liquid ejecting apparatus according to this embodiment, the malfunction detection unit 70 outputs the output signal of the vibration detection unit 25 when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0, and the liquid detection chamber. 21 is compared with the output signal of the vibration detection unit 25 when the flow rate of the liquid flowing through 21 is not 0 at the same time when the remaining amount of liquid in the liquid storage container is the same. It can be detected with high accuracy.

B. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

B1. Modification 1:
In the above embodiment, the remaining amount determination unit 60 sets the absolute value threshold Pth of the negative pressure to the same magnitude (3.0 kPa) as the pressure generated by the compression spring 29, but the threshold Pth is arbitrary. Can be set to a value of. However, if the threshold value Pth is set to the same magnitude as the pressure generated by the compression spring 29, the distance L becomes 0 at the timing when the absolute value of the negative pressure coincides with the threshold value Pth. It can be easily detected that the absolute value of the negative pressure matches the threshold value Pth.

B2. Modification 2:
In the above-described embodiment, the malfunction detection unit 70 and the remaining amount determination unit 60 are provided in the liquid ejecting apparatus main body 2, but one or both of the malfunction detection unit 70 and the remaining amount determination unit 60 are liquid containers. 1 may be provided.

B3. Modification 3:
In the above embodiment, the malfunction detection unit 70 calculates the negative pressure (Pp + Pr) in the liquid detection chamber 21 based on one or both of the amplitude and frequency of the output signal of the vibration detection unit 25. The detection unit 70 does not obtain the negative pressure in the liquid detection chamber 21, and the output signal when the flow rate of the liquid flowing through the liquid detection chamber 21 is 0 and the flow rate of the liquid flowing through the liquid detection chamber 21 are not 0 It is also possible to determine whether or not the liquid detection device 11 is operating normally by directly comparing the output signal at.

B4. Modification 4:
In the above embodiment, an ink jet printing apparatus is employed, but a liquid ejecting apparatus that ejects or discharges liquid other than ink may be employed. The liquid here includes a liquid body in which particles of a functional material are dispersed in a solvent, and a fluid body such as a gel. For example, liquid ejecting devices and biochips that eject liquid containing materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, surface-emitting displays, color filters, etc. It may be a liquid ejecting apparatus that ejects a bio-organic matter used for manufacturing, or a liquid ejecting apparatus that ejects a liquid that is used as a precision pipette and is a sample. In addition, transparent resin liquids such as UV curable resins to form liquid injection devices that inject lubricating oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate, or a liquid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate or the like may be employed. The present invention can be applied to any one of these injection devices.

B5. Modification 5:
In the above embodiment, a part of the functions realized by software may be realized by hardware, or a part of the functions realized by hardware may be realized by software.

It is explanatory drawing which shows the structure of the liquid ejecting apparatus as one Example of this invention. It is explanatory drawing which shows operation | movement of the diaphragm pump. It is explanatory drawing which shows operation | movement of the diaphragm pump. It is explanatory drawing which shows operation | movement of the diaphragm pump. It is explanatory drawing which shows the structure of the liquid container as one Example of this invention. FIG. 5 is an explanatory diagram showing the liquid container 1 when there is sufficient liquid in the liquid container 7 and there is a liquid flow in the liquid detection chamber 21. FIG. 6 is an explanatory diagram showing the liquid container 1 when the liquid in the liquid container 7 is reduced and approaches an ink end state. It is explanatory drawing which shows the liquid storage container 1 in case the liquid in the liquid storage part 7 further reduces and it will be in an ink end state. 6 is a graph showing the relationship between the remaining amount of liquid in the liquid storage unit and the negative pressure in the liquid detection chamber. FIG. 10 is an explanatory diagram in which a graph (G3) during maintenance of the recording head 46 is added to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid container 2 ... Liquid injection apparatus main body 3 ... Internal space 5 ... Case 5a ... Partition 7 ... Liquid storage part 7a ... Discharge port 7b ... Bag body 9 ... Liquid supply port 11 ... Liquid detection apparatus 11a ... Liquid inflow port 11b ... Liquid outlet 13 ... Open air hole 14 ... Check valve 19 ... Detection device case 19a ... Recessed space 19b ... Bottom 21 ... Liquid detection chamber 23 ... Flexible part (flexible film)
25 ... Vibration detection unit 27 ... Moving member 29 ... Biasing member (compression spring)
DESCRIPTION OF SYMBOLS 31 ... Support base 33 ... Liquid guide path 35 ... Piezoelectric vibration element 40 ... Liquid introduction part (liquid supply needle)
40a ... Liquid inflow hole 40b ... Liquid flow path 41 ... Flow path opening / closing valve 42 ... Diaphragm pump 42a ... Decompression chamber 42b ... Diaphragm 42c ... Diaphragm chamber 42d ... Compression spring 42i ... Liquid inlet 42o ... Liquid outlet 43 ... Check valve 44 ... Liquid supply flow path 46 ... Liquid ejecting section (recording head)
DESCRIPTION OF SYMBOLS 47 ... Cap 48 ... Suction pump 49 ... Waste ink absorber 50 ... Air flow path 51 ... Atmospheric release valve 52 ... Pressure detector 53 ... Decompression pump 60 ... Determination part 70 ... Operation failure detection part

Claims (11)

A liquid ejecting apparatus,
A liquid container that contains the liquid ejected from the liquid ejecting apparatus;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid ejecting apparatus further includes:
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0;
A liquid ejecting apparatus comprising a malfunction detection unit that detects malfunction of the liquid detection apparatus by comparing the remaining amounts of liquid at the same time. The liquid ejecting apparatus according to claim 1,
The malfunction detection unit is
Detecting the pressure value in the liquid detection chamber from the signal waveform of the detection signal;
The pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is 0,
When the flow rate of the liquid flowing through the liquid detection chamber is larger than the pressure value in the liquid detection chamber detected when the flow rate is not zero,
A liquid ejecting apparatus that determines that the operation of the liquid detecting apparatus is normal. The liquid ejecting apparatus according to claim 1 or 2,
The malfunction detection unit is
Detecting the pressure value in the liquid detection chamber from the signal waveform of the detection signal;
When the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is not 0 becomes a predetermined threshold value or less,
When the pressure value in the liquid detection chamber detected when the flow rate of the liquid flowing through the liquid detection chamber is 0 is larger than the predetermined threshold,
A liquid ejecting apparatus that determines that the operation of the liquid detecting apparatus is normal. The liquid ejecting apparatus according to any one of claims 1 to 3,
The liquid ejecting apparatus includes a case where the liquid ejecting apparatus ejects the liquid when the flow rate of the liquid flowing through the liquid detection chamber is not zero. The liquid ejecting apparatus according to claim 1, further comprising:
A suction pump for sucking the liquid in the liquid container;
The liquid ejecting apparatus including a case where the flow rate of the liquid flowing through the liquid detection chamber is not 0, the suction pump sucking the liquid in the liquid storage unit. The liquid ejecting apparatus according to claim 1, further comprising:
A liquid ejecting section for ejecting the liquid in the liquid containing section;
A liquid suction part for sucking the liquid in the fluid storage part through the liquid ejection part,
The liquid ejecting apparatus including a case where the liquid suction unit sucks the liquid in the liquid ejecting unit when the flow rate of the liquid flowing through the liquid detection chamber is not zero. The liquid ejecting apparatus according to any one of claims 1 to 6,
The liquid detection chamber is
A flexible portion formed on one surface of the liquid detection chamber and deformable according to the pressure in the liquid detection chamber;
A moving member housed in the liquid detection chamber and movable in accordance with deformation of the flexible portion;
An urging member that urges the moving member in a direction opposite to a moving direction of the moving member due to a decrease in the pressure;
Including
The said detection signal production | generation part is a liquid ejecting apparatus which produces | generates the said detection signal which has a signal waveform according to the position of the said moving member. The liquid ejecting apparatus according to claim 7,
The detection signal generator is
A piezoelectric device that has a concave portion on a surface facing the moving member, applies vibration to the liquid filled in the concave portion, and generates the detection signal having a signal waveform corresponding to a state of free vibration generated along with the vibration. A liquid ejecting apparatus which is a detection unit. A liquid ejecting apparatus main body for ejecting liquid supplied from a liquid storage container,
The liquid container is
A liquid container for containing the liquid;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid ejecting apparatus main body is
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
An operation failure detection unit that detects an operation failure of the liquid detection device by comparing the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of the liquid is provided. Liquid ejector body. A liquid container,
A liquid container that contains the liquid ejected from the liquid ejecting apparatus main body;
A liquid detection device for detecting a remaining amount of liquid stored in the liquid storage unit;
With
The liquid detection device includes:
A liquid detection chamber in communication with the liquid container;
A detection signal generator for generating a detection signal having a signal waveform corresponding to the pressure in the liquid detection chamber;
With
The liquid container further includes:
The detection signal when the flow rate of the liquid flowing through the liquid detection chamber is 0;
An operation failure detection unit that detects an operation failure of the liquid detection device by comparing the detection signal when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of the liquid is provided. Liquid container. A method for detecting a malfunction of a liquid detection device including a liquid detection chamber communicating with a liquid storage unit,
The pressure in the liquid detection chamber when the flow rate of the liquid flowing through the liquid detection chamber is 0;
The malfunction of the liquid detection device is detected by comparing the pressure in the liquid detection chamber when the flow rate of the liquid flowing through the liquid detection chamber is not 0 with the remaining amount of liquid in the liquid storage unit at the same time. how to.

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