JP4340862B2 - Liquid pressure control device, liquid ejection device provided with the liquid pressure control device, and liquid pressure control program - Google Patents

Description

The present invention includes a liquid ejecting head that ejects liquid onto a material to be ejected, a liquid container that is hermetically filled with liquid, a pressure chamber, a valve body that compresses and pressurizes air in the pressure chamber, and an opening / closing valve for the pressure chamber. When the valve body is moved in the compression direction, the air in the pressure chamber is compressed and pressurized with the on-off valve closed, and by moving the valve body in the direction opposite to the compression direction, the on-off valve is opened and the air pressure is opened. An air compressor for reducing the air in the chamber to atmospheric pressure and a pressure detection means for detecting the pressure in the air pressure chamber are provided in the liquid container with a supply pressure corresponding to the pressure of the air pressure compressed and pressurized by the air compressor. In the liquid ejecting apparatus having a configuration in which the filled liquid is pumped to the liquid ejecting head, the driving force source of the valve body is controlled based on the pressure detected by the pressure detecting means, and the liquid ejecting head is moved from the liquid container. Liquid to control liquid supply pressure to Pressure control device, and a liquid ejecting apparatus having the liquid pressure control device.
Here, the liquid ejecting apparatus is not limited to an ink jet recording apparatus that performs recording on a recording material by ejecting ink from the recording head onto a recording material such as recording paper, a copying machine, and a facsimile. And a device for ejecting a liquid corresponding to a specific application instead of the ink from a liquid ejecting head corresponding to the above-described recording head to an ejecting material corresponding to the recording material and attaching the liquid to the ejecting material. Used in meaning. In addition to the recording head described above, the liquid ejecting head includes a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material used for forming an electrode such as an organic EL display and a surface emitting display (FED) ( Examples thereof include a conductive paste) ejection head, a bio-organic matter ejection head used for biochip manufacturing, and a sample ejection head that ejects a sample as a precision pipette.

  A liquid ejecting apparatus typified by an ink jet recording apparatus is equipped with a liquid ejecting head that ejects liquid onto an ejected material, and the liquid ejecting head has a trace amount on the head surface facing the ejected material. A large number of liquid ejection nozzles that eject liquid droplets are arranged. In a liquid ejecting head, for example, a piezoelectric element is disposed in a pressure chamber provided in a nozzle opening of a liquid ejecting nozzle. When an electric signal is applied to the piezoelectric element, the piezoelectric element expands and contracts, and the liquid pressure in the pressure chamber is increased. It changes so that a small amount of liquid is ejected from the nozzle opening. Further, in general, liquid is supplied from the liquid storage unit in which each liquid ejecting nozzle is in fluid communication to each liquid ejecting nozzle by a negative pressure generated by expansion and contraction of a fluid pressure chamber provided in the nozzle opening of each liquid ejecting nozzle. Aspirated and supplied. However, for example, the recording head (liquid ejecting head) and the ink cartridge (liquid storage unit) are arranged apart from each other as in a large ink jet recording apparatus, and the recording head and the ink cartridge are hollow. In a liquid ejecting apparatus that is in fluid communication via a tube or the like, a necessary and sufficient amount of ink (liquid) is sucked and supplied from an ink cartridge only by the negative pressure generated at each liquid ejecting nozzle during liquid ejecting. It may not be possible. Therefore, in such an ink jet recording apparatus, for example, a mechanical pressure unit such as a leaf spring is provided in the ink cartridge, and the ink in the ink cartridge is pressurized and sent toward the recording head by the spring force of the leaf spring. There are known ones that perform the pressure-feeding of ink using the siphon phenomenon caused by atmospheric pressure (for example, see Patent Document 1).

JP-A-4-366433

  However, in a liquid ejecting apparatus that pressurizes and delivers liquid from a liquid storage unit to a liquid ejecting head using a mechanical pressurizing means such as a leaf spring or a siphon phenomenon caused by atmospheric pressure, the supply pressure of the liquid is controlled. I can't. Accordingly, the liquid supply path to the liquid jet head such as the liquid jet head and the hollow tube is always constant regardless of the liquid jet execution state from the liquid jet head and the power ON / OFF state of the liquid jet device. The load due to the above ink supply pressure remains on for a long time. For this reason, when a liquid leak occurs in the liquid supply path from the liquid storage unit to the liquid ejecting head, the liquid may continue to leak until substantially all of the liquid in the liquid storage unit is exhausted. Therefore, for example, in an ink jet recording apparatus, the ink leaks until the ink in the ink cartridge becomes empty, and there is a possibility that the inside of the ink jet recording apparatus or the periphery of the ink jet recording apparatus is stained with ink. is there.

  SUMMARY An advantage of some aspects of the invention is that liquid leakage occurs in a liquid supply path from a liquid storage unit to a liquid ejecting head in a liquid ejecting apparatus such as an ink jet recording apparatus. The purpose is to reduce the amount of liquid leakage in the case of jamming.

  To achieve the above object, according to a first aspect of the present invention, a liquid ejecting head that ejects liquid onto a material to be ejected, a liquid container in which the liquid is hermetically filled, a pressure chamber, and air in the pressure chamber are compressed. The liquid container has a valve body to be pressurized and an opening / closing valve for the atmospheric pressure chamber, and the air in the atmospheric pressure chamber is compressed and pressurized with the opening / closing valve closed by moving the valve body in the compression direction. The air valve is opened by moving the valve body in the direction opposite to the compression direction, and the air pressure in the air pressure chamber is reduced to the atmospheric pressure by detecting the pressure in the air pressure chamber. A liquid having a configuration in which the liquid filled in the liquid container is pumped to the liquid ejecting head with a supply pressure corresponding to the pressure of the air pressure compressed and pressurized by the air compressor. In the injection device, the air The compressor includes a pressure limit position detecting means for detecting that the valve body has moved to a pressure limit position set in advance as a movement limit position in the compression direction of the valve body, and is opposite to the compression direction of the valve body. Initial pressure position detecting means for detecting that the valve body has moved to an initial pressure position preset as a movement limit position in the direction, and the valve based on the pressure detected by the pressure detection means A liquid pressure control device that controls a body driving force source to increase or decrease a supply pressure of the liquid from the liquid container to the liquid ejecting head, and detects an abnormality at the start of driving of the valve body driving force source When a timer is started and the moving direction of the valve body is the compression direction, the pressure value detected by the pressure detecting means is a predetermined value when the count value of the abnormality detection timer exceeds a predetermined count value. Under pressure If the movement position of the valve body is not detected by the pressurization limit position detection means, it is determined that either the pressure detection means or the pressurization limit position detection means is abnormal, and When the increase / decrease control of the supply pressure of the liquid is stopped and the moving direction of the valve body is the opposite direction to the compression direction, the valve body when the count value of the abnormality detection timer exceeds the predetermined count value If the initial pressurizing position detecting means is not detected, the initial pressurizing position detecting means is determined to be abnormal, and the increase / decrease control of the liquid supply pressure is stopped. Liquid pressure control device.

  Thus, the air compressor is provided with the air compressor, the driving force source for moving the valve body of the air compressor, and the pressure detecting means for detecting the pressure of the air pressure chamber of the air compressor. Thus, the liquid filled in the liquid container is pumped to the liquid ejecting head with a supply pressure corresponding to the pressure of the compressed and pressurized air pressure. In the air compressor, the air in the air pressure chamber is compressed and pressurized while the on-off valve is closed by moving the valve body in the compression direction, and the on-off valve is opened by moving the valve body in the direction opposite to the compression direction. Since the air in the air pressure chamber is reduced to atmospheric pressure by controlling the valve, the driving force source of the valve body is controlled based on the pressure detector of the pressure detecting means to control the moving position of the valve body. As a result, the liquid supply pressure from the liquid container to the liquid ejecting head can be controlled to increase or decrease. Further, the air compressor includes a pressurization limit position detecting means for detecting that the valve body has moved to a pressurization limit position set in advance as a movement limit position in the compression direction of the valve body, and is opposite to the compression direction of the valve body. An initial pressurizing position detecting means for detecting that the valve body has moved to an initial pressurizing position set in advance as a movement limit position in the direction.

  In the liquid ejecting apparatus having such a configuration, even if the valve body is continuously moved in the compression direction beyond the operation time of the driving force source sufficient to move from the initial pressurization position to the pressurization limit position, pressurization is performed. If it cannot be detected that the valve has reached the limit position, the pressure in the pressure chamber cannot be detected due to an abnormality in the pressure detection means even though the pressure in the pressure chamber exceeds the predetermined pressure. There is a risk of becoming. Or there exists a possibility that it may be in the state which cannot detect that the valve body position reached | attained the pressurization limit position by abnormality of the pressurization limit position detection means. For this reason, if the valve body driving means continues to be driven further, excessive force acts on the valve body and the air compressor may be damaged, the air pressure supply path, the liquid storage section, the liquid supply path, or the liquid There is a possibility that excessive pressure is applied to the ejection head, causing air pressure leakage or liquid leakage. Therefore, an abnormality detection timer is started when the driving force source of the valve element is started, and the time during which the driving force source of the valve element operates continuously is counted. If the moving direction of the valve body at this time is the compression direction, whether or not the pressure value detected by the pressure detection means is less than a predetermined pressure when the count value of the abnormality detection timer exceeds the predetermined count value And whether or not the movement position of the valve body is detected and detected by the pressurization limit position detecting means. Here, the predetermined count value is set to, for example, a count value corresponding to the operation time of the driving force source sufficient for the valve body to move from the initial pressurization position to the pressurization limit position. When the count value of the abnormality detection timer exceeds the preset count value, the pressure value detected by the pressure detection means is less than the predetermined pressure, and the moving position of the valve body is detected by the pressurization limit position detection means. If not, it is determined that either the pressure detection means or the pressurization limit position detection means is abnormal, and the increase / decrease control of the liquid supply pressure is stopped. As a result, an excessive force is applied to the valve body and the air compressor is damaged, or an excessive pressure is applied to the air pressure supply path, the liquid storage unit, the liquid supply path, or the liquid ejecting head, and the air leaks. It is possible to reduce the risk of liquid leakage.

  On the other hand, even if the valve body is continuously moved in the direction opposite to the compression direction beyond the operating time of the driving force source sufficient to move from the pressurization limit position to the initial pressurization position, the valve body does not move to the initial pressurization position. When it is not possible to detect the arrival, there is a possibility that the valve body position cannot be detected due to the abnormality of the initial pressurization position detection means. For this reason, if the valve body drive means continues to be driven, an excessive force may act on the valve body and the air compressor may be damaged. Therefore, an abnormality detection timer is started when the driving force source of the valve element is started, and the time during which the driving force source of the valve element operates continuously is counted. When the moving direction of the valve body at this time is opposite to the compression direction, the moving position of the valve body is the initial pressurizing position detecting means when the count value of the abnormality detection timer exceeds the predetermined count value described above. It is determined whether or not it has been detected. If the movement position of the valve body is not detected by the initial pressurization position detection means when the count value of the abnormality detection timer exceeds the predetermined count value, it is determined that the initial pressurization position detection means is abnormal. Stop the increase / decrease control of the liquid supply pressure. Thereby, the possibility that an excessive force acts on the valve body and the air compressor is damaged can be reduced.

  Thereby, according to the liquid pressure control device shown in the first aspect of the present invention, an excessive force acts on the valve body and the air compressor is damaged, or the air pressure supply path, the liquid storage section, It is possible to reduce the risk of air pressure leakage or liquid leakage due to excessive pressure applied to the liquid supply path or the liquid ejecting head, and even if liquid leakage should occur, Since the expansion of liquid leakage can be reduced, in a liquid ejecting apparatus such as an ink jet recording apparatus, the amount of liquid leakage is minimized when a liquid leak occurs in the liquid supply path from the liquid storage unit to the liquid ejecting head. The effect of being able to reduce to the limit is obtained.

A second aspect of the present invention, in the first embodiment described above, the predetermined count value, the count value when the valve body from the initial pressing position to said pressurization limit position is moved at the maximum load The liquid pressure control device is characterized by being set.

The time required for the valve body to move at the maximum load from the initial pressurization position to the pressurization limit position is that the valve body is operated continuously at a constant driving speed while the air compressor is operating normally. Is the maximum time when moving from the initial pressure position to the pressure limit position without stopping. Therefore, by setting the count value corresponding to this time as the default count value, when the count value of the abnormality detection timer exceeds the default count value, the pressurization limit position detection means and the initial pressurization position detection means It can be determined in the shortest time that an abnormality has occurred in any of them. As a result, the time that the driving force source of the valve element operates in the state where any one of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means is abnormal is reduced to the minimum. It becomes possible to do.

  According to a third aspect of the present invention, in the first aspect or the second aspect described above, any one of the pressure detection unit, the pressurization limit position detection unit, and the initial pressurization position detection unit is abnormal. Is determined, the abnormal code is written in the nonvolatile storage medium, and the abnormal code is written by referring to whether the abnormal code is written in the nonvolatile storage medium when the liquid ejecting apparatus is turned on. If it is, the liquid pressure control device stops the increase / decrease control of the liquid supply pressure.

  An abnormality has occurred in any of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means. This means that a pressure leak has occurred in either the air pressure of the air compressor or the liquid supply pressure. At least one of the air compressor, the air pressure path from the air compressor to the liquid reservoir, the liquid supply path from the liquid reservoir to the liquid ejecting head, and the liquid ejecting head requires repair. It is considered that there is a high possibility that an abnormality has occurred. Therefore, after determining that an abnormality has occurred in any of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means, in order to reliably prevent further expansion of liquid leakage, It is necessary to maintain the liquid ejecting apparatus in an unusable state in a state that cannot be restored by the user's own operation. Therefore, it is necessary to maintain an abnormality history that an abnormality has occurred in any of the pressure detection unit, the pressurization limit position detection unit, and the initial pressurization position detection unit even when the power of the liquid ejecting apparatus is turned off.

  Therefore, when it is determined that an abnormality has occurred in any of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means, an abnormality code is written in the nonvolatile storage medium. Thereby, even when the power of the liquid ejecting apparatus is turned off, it is possible to maintain an abnormality history that an abnormality has occurred in any of the pressure detection means, the pressure limit position detection means, and the initial pressure position detection means. When the power of the liquid ejecting apparatus is turned on, it is referred to whether or not an abnormal code is written in the nonvolatile storage medium. If the abnormal code is written, the increase / decrease control of the liquid supply pressure is stopped. Accordingly, it is possible to more reliably prevent the liquid leakage from further expanding after the liquid leakage has occurred in the liquid supply path from the liquid storage unit to the liquid ejecting head. If a liquid leak occurs in the liquid supply path from the liquid storage unit to the liquid ejecting head, the service man of the liquid ejecting apparatus manufacturer repairs the abnormal part and erases the abnormal code in the nonvolatile storage medium. It is only necessary to return the liquid ejecting apparatus to a usable state at the time of performing the above.

A fourth aspect of the present invention is a liquid ejecting apparatus including the liquid pressure control device according to any one of the first to third aspects described above.
According to the liquid ejecting apparatus shown in the fourth aspect of the present invention, in the liquid ejecting apparatus, the operational effects of the invention according to any one of the first to third aspects described above can be obtained.

  According to a fifth aspect of the present invention, there is provided a liquid ejecting head that ejects liquid onto a material to be ejected, a liquid container that is hermetically filled with the liquid, a pressure chamber, a valve body that compresses and pressurizes air in the pressure chamber, and the An air pressure chamber opening / closing valve, and by moving the valve body in the compression direction, the air in the air pressure chamber is compressed and pressurized and sent to the liquid container with the opening / closing valve closed; An air compressor in which the on-off valve is opened by moving the valve in a direction opposite to the compression direction so that the air in the atmospheric pressure chamber is decompressed to atmospheric pressure, and pressure detecting means for detecting the pressure in the atmospheric pressure chamber. In the liquid ejecting apparatus having the configuration in which the liquid filled in the liquid container is pumped to the liquid ejecting head with a supply pressure corresponding to the pressure of the air pressure compressed and pressurized by the air compressor. The container is a compression of the valve body A pressure limit position detecting means for detecting that the valve element has moved to a pressure limit position set in advance as a movement limit position in the direction, and a movement limit position in a direction opposite to the compression direction of the valve element. An initial pressurizing position detecting means for detecting that the valve body has moved to the initial pressurizing position, and controlling the driving force source of the valve body based on the pressure detected by the pressure detecting means. A liquid pressure control program for causing a computer to execute control to increase or decrease the supply pressure of the liquid from the liquid container to the liquid ejecting head, wherein an abnormality detection timer is set at the start of driving of the driving force source of the valve body When the starting procedure and the moving direction of the valve body are in the compression direction, the pressure detection means detects when the count value of the abnormality detection timer exceeds a predetermined count value. If the force value is less than a predetermined pressure and the movement position of the valve element is not detected by the pressurization limit position detection means, one of the pressure detection means and the pressurization limit position detection means In the case where it is determined that there is an abnormality and the increase / decrease control of the supply pressure of the liquid is stopped, and when the moving direction of the valve body is opposite to the compression direction, the count value of the abnormality detection timer is the predetermined count If the movement position of the valve body is not detected by the initial pressurization position detection means when the value is exceeded, it is determined that the initial pressurization position detection means is abnormal and the supply pressure of the liquid is A liquid pressure control program characterized by having a procedure for stopping the increase / decrease control.

  According to the liquid pressure control program described in the fifth aspect of the present invention, it is possible to obtain the same operation effect as the invention described in the first aspect described above, and to execute this liquid pressure control program. Any liquid ejecting apparatus that can perform the same effects as the invention described in the first aspect described above can be provided.

A sixth aspect of the present invention, in the fifth aspect of the aforementioned, the default count value, the count value when the valve body from the initial pressing position to said pressurization limit position is moved at the maximum load A liquid pressure control program characterized by being set.

  According to the liquid pressure control program described in the sixth aspect of the present invention, it is possible to obtain the same operation and effect as the invention described in the second aspect described above, and to execute the liquid pressure control program. Any liquid ejecting apparatus that can perform the same effects as the invention described in the second aspect described above can be provided.

  According to a seventh aspect of the present invention, in the fifth aspect or the sixth aspect described above, any of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means is abnormal. If it is determined that the abnormal code is written to the nonvolatile storage medium, and whether the abnormal code is written to the nonvolatile storage medium when the liquid ejecting apparatus is turned on, the abnormal code is referred to. Is written, the liquid pressure control program has a procedure of stopping the increase / decrease control of the supply pressure of the liquid.

  According to the liquid pressure control program described in the seventh aspect of the present invention, it is possible to obtain the same operation effect as the invention described in the third aspect described above, and to execute this liquid pressure control program. Any liquid ejecting apparatus that can perform the same effects as the invention described in the third aspect described above can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of the ink jet recording apparatus, and FIG. 2 is a perspective view of the ink jet recording apparatus with the main body cover removed. FIG. 3 is a schematic side sectional view of the ink jet recording apparatus. FIG. 4 is a block diagram of a control unit that performs various controls of the ink jet recording apparatus.

  First, a schematic configuration of an ink jet recording apparatus 50 as a “liquid ejecting apparatus” according to the invention will be described with reference to FIGS. The ink jet recording apparatus 50 has a box-like appearance, is formed as large as a video tape recorder, and is configured to be used in a state of being stored in a TV rack or the like. ing. A front cover 2 that can be opened and closed in front is provided at the front center of the box-shaped body cover 1. From the opening of the front cover 2 that opens to the front, When the recording paper P as the “jetting material” is discharged and recording is performed on the label surface of the optical recording disc D such as a DVD, the optical recording disc as the “jetting material” mounted on the disc tray 7 The disc tray 7 temporarily protrudes from the inside of the ink jet recording apparatus 50 during execution of recording on D. Further, the front cover 2 serves as a stacker for stacking recording sheets P discharged after recording is performed with the front cover 2 opened to the front side. A paper feed cassette 8 as a “recording paper storage unit” for stacking the recording papers P is provided below the front cover 2, and recording is performed in the paper feeding cassette 8 while being pulled out to the front side. Paper P can be stacked. An openable / closable cover 3 is provided above the front cover 2, and an ink cartridge unit 15 is provided in the openable / closable cover 3. In the ink cartridge unit 15, a plurality of ink cartridges 16 (see FIG. 3) as “liquid containers” filled with ink as “liquid” are detachably arranged side by side in the width direction of the ink jet recording apparatus 50. The ink cartridge 16 can be replaced with the opening / closing cover 3 opened. On the left side of the front cover 2, a memory slot cover 4 having a memory slot to which a flash memory card and the like can be attached and detached is disposed.

  Next, an outline of the internal configuration of the ink jet recording apparatus 50 will be described with reference to FIG. The base of the ink jet recording apparatus 50 includes a lower chassis 13, a main frame 11 extending in the width direction of the main body of the ink jet recording apparatus 50, and a depth direction of the main body of the ink jet recording apparatus 50 disposed on both sides of the main frame 11. The side frame right 12 and the side frame left 14 are parallel to each other. Between the right side frame 12 and the left side frame 14, a carriage guide shaft 51 and a sub carriage guide shaft 511 are pivotally supported at a predetermined interval in the sub scanning direction Y in parallel with the main scanning direction X. . The carriage guide shaft 51 and the sub-carriage guide shaft 511 are guides for supporting the carriage 61 on which the recording head 62 as a “liquid ejecting head” that ejects ink onto the recording paper P is reciprocally movable in the main scanning direction X. The carriage guide shaft 51 is inserted through the rear portion of the carriage 61, and the sub-carriage guide shaft 511 supports the front portion of the carriage 61 from below, whereby the recording head 62 mounted on the carriage 61 (FIG. 3). ) And the recording paper P facing the head surface of the recording head 62 (platen gap: hereinafter referred to as “PG”) is defined so that the carriage 61 can reciprocate in the main scanning direction X. Is done.

Next, the conveyance path of the recording paper P as the “material to be ejected” and the disc tray 7 will be described with reference to FIGS. 2 and 3.
An “automatic paper feeder” that automatically feeds recording paper P one by one as a recording material toward a “sub-scanning drive unit” described later includes a paper feed cassette 8 and a paper feed roller 83. A hopper 81 is provided at the bottom of the paper feed cassette 8 on which a plurality of recording papers P are stacked. The hopper 81 is disposed so as to be swingable with a shaft 82 as a swing shaft. By pushing up the recording paper P stacked on the hopper 81 from below, recording is performed on a paper feed roller 83 provided on the top. Press the paper P. The paper feed roller 83 has a substantially D shape when viewed from the side, and the outer periphery is formed of a high friction member (for example, a rubber material). When the recording paper P is fed, the uppermost recording paper P in contact with the arc portion of the paper feeding roller 83 is fed in the sub-scanning direction Y by the rotation of the paper feeding roller 83. The “automatic paper feeder” is disposed below the paper feed roller 83, and the recording paper P whose surface is pressed against the outer peripheral surface of the paper feed roller 83 by the hopper 81 is fed by the drive rotation of the paper feed roller 83. A separation pad (not shown) is provided as a “separation unit” that prevents another recording paper P from being overlapped when fed in the paper direction (sub-scanning direction Y). . By feeding the recording paper P while rotating the paper feeding roller 83 with the recording paper P sandwiched between the separation pad and the paper feeding roller 83, the recording paper P to be fed and the other are about to be fed. The recording paper P is separated. Further, the “automatic paper feeder” pushes back the recording paper P, which is separated by the separation pad and partially protrudes outside the paper feeding cassette 8 on which the recording paper P is stacked, into the paper feeding cassette 8. In addition, the recording paper P partially protruding outside the paper feed cassette 8 is disposed under the paper feed roller 83 so as to be able to advance into the paper feed path so as to be pushed toward the paper feed cassette 8. A paper return lever (not shown) as a “paper return rocking body” is provided.

  On the downstream side of the paper feed roller 83 in the sub-scanning direction Y, a conveyance drive roller 53 having a high frictional resistance film uniformly applied to the outer peripheral surface, and can be driven to rotate while being pressed and urged by the conveyance drive roller 53. A conveyance driven roller 54 that is pivotally supported by the PF motor 57 as a “conveyance drive motor” that drives the conveyance drive roller 53 and a “rotation” that detects the rotation amount of the conveyance drive roller 53. The rotary encoder 31 as “amount detection means” constitutes “sub-scanning drive means” for transporting the recording paper P or the disc tray 7 in the sub-scanning direction Y by a predetermined transport amount. The “sub-scanning driving means” sandwiches the recording paper P or the disk tray 7 between the transport driving roller 53 and the transport driven roller 54, and the rotational driving force of the PF motor 57 is transmitted to the pulley 59 via the endless belt 58. The recording paper P or the disk tray 7 is transported in the sub-scanning direction Y by the rotation of the transport driving roller 53 that is driven and rotated by the rotation of the pulley 59 transmitted through an intermediate gear (not shown). The rotation amount of the PF motor 57 is described later according to the rotation amount of the conveyance drive roller 53 detected by the rotary encoder 31 so that the recording paper P or the disc tray 7 is conveyed by a predetermined conveyance amount. Controlled by.

  A platen 52 is disposed on the downstream side of the transport driving roller 53 in the sub-scanning direction Y so as to face the head surface of the recording head 62 in the vertical direction. The recording paper P or the disc tray 7 conveyed by the above-mentioned “sub-scanning driving means” is supported by the platen 52 from below, and the recording head 62 reciprocates in the main scanning direction X by the “main scanning driving means”. Recording is performed by ejecting ink from the ink. The “main scanning driving means” includes a carriage 61 and a CR motor 63 as a “carriage driving motor” serving as a driving force source for reciprocating the carriage 61. The rotational driving force of the CR motor 63 is shown in FIG. A rotational motion is converted into a linear reciprocating motion and transmitted to the carriage 61 via a driving force transmission mechanism such as an endless belt (not shown). In this embodiment, the recording head 62 is provided at the bottom of the carriage 61, but no ink cartridge is mounted on the carriage 61 that reciprocates in the main scanning direction X, and the ink cartridge unit 15 described above. Ink is supplied to the carriage 61 through the flexible collecting tube 17 from the plurality of ink cartridges 16 stored in the printer. In the flexible collecting tube 17, ink tubes 171 as independent “liquid supply paths” are formed in the number corresponding to the number of ink cartridges 16. The ink in each ink cartridge 16 is pressurized by a bellows pump unit as an “air compressor” to be described later, and supplied individually to the recording head 62 via each ink tube 171 of the flexible collecting tube 17. It has become.

  On the downstream side of the recording head 62 in the sub-scanning direction Y, the rotational driving force of the PF motor 57 is transmitted and rotated to be driven, and the paper driving roller 55 can be driven and rotated while being urged by the paper discharging drive roller 55. A paper discharge driven roller 56 supported on the shaft is disposed. The recording paper P during and after recording is sandwiched between the paper discharge driving roller 55 and the paper discharge driven roller 56, and the rotational driving force of the PF motor 57 is transmitted to the pulley 59 via the endless belt 58. The rotation of 59 is transmitted through an intermediate gear (not shown) and the like, and is discharged from the opening that opens the front panel 2 in the sub-scanning direction Y by the rotation of the discharge driving roller 55 that rotates. A disc tray 7 on which the optical recording disc D can be mounted is disposed above the paper feed cassette 8. The disc tray 7 has a rack 71 (see FIG. 2) formed on the side end thereof, and is arranged so as to be able to move straightly in a substantially horizontal posture by rotation of a pinion gear (not shown) that meshes with the rack 71. ing. Then, after the disk tray 7 is conveyed until the leading end is nipped by the conveyance drive roller 53 and the conveyance driven roller 54 by the rotation of the pinion gear, the conveyance drive roller 53 is rotated in both directions thereafter. It is sent in the sub-scanning direction Y or the reverse feed direction YR. Further, when the optical recording disk D is attached to or detached from the disk tray 7, the optical recording disk D is transported in the sub-scanning direction Y to a position protruding from the opening where the front panel 2 is opened (a position indicated by a virtual line in FIG. 2).

Next, the configuration of the control unit 100 will be described with reference to FIG.
The control unit 100 is connected to a host computer 200 that transmits recording control data to the ink jet recording apparatus 50 so that data can be transmitted and received. The control unit 100 includes a ROM 101, a RAM 102, an interface unit 103, an MPU 104, a DC unit 105, a PF motor driver 106, a CR motor driver 107, a head driver 108, and a nonvolatile memory 109 as a “nonvolatile storage medium”. . The MPU 104 and the DC unit 105 include a rotary encoder 31 as a “rotation amount detection unit” that detects the rotation amount of the transport driving roller 53, and a linear encoder 32 as a “carriage movement amount detection unit” that detects the movement amount of the carriage 61. The paper detector 33 for detecting the start and end of the recording paper P being conveyed, the PW sensor 34 for detecting the width in the main scanning direction X of the recording paper P mounted on the carriage 61, and the power source of the ink jet recording apparatus 50 are turned on. Output signals of a power supply SW 35 for turning on / off and a tray SW 36 for performing a loading / unloading operation of the disk tray 7 are input. In this embodiment, the PW sensor 34 is an optical sensor provided at the bottom of the carriage 61. The PW sensor 34 detects the width of the recording paper P in the sub-scanning direction Y by the main scanning of the carriage 61, and the disc tray 7 This is used to detect the feed position of the disc tray 7 by recognizing an identification mark (not shown) attached to. Further, it is also used for detecting the presence or absence of the disk D on the disk tray 7 and the center position of the disk D.

  The MPU 104 performs arithmetic processing for executing the control program of the ink jet recording apparatus 50 and other necessary arithmetic processing. The ROM 101 stores a control program (firmware) necessary for controlling the ink jet recording apparatus 50, data necessary for processing, and the like. The interface unit 103 has a communication interface function with the host computer 200, receives recording control data from the host computer 200, and also has a driver for the memory slot 37 and an interface function. The RAM 102 is used as a primary storage area for various data including recording control data transferred through the work area of the MPU 104 and the interface unit 103. The nonvolatile memory 109 stores various types of information that need to be retained even after the inkjet recording apparatus 50 is turned off. The DC unit 105 is a control circuit for performing speed control of the PF motor 57 and the CR motor 63 that are DC motors. The DC unit 105 determines the speeds of the PF motor 57 and the CR motor 63 based on the control command sent from the MPU 104, the output signal of the rotary encoder 31, the output signal of the linear encoder 32, and the output signal of the paper detector 33. Various calculations for control are performed, and motor control signals based on the calculation results are sent to the PF motor driver 106 and the CR motor driver 107. The PF motor driver 106 drives and controls the PF motor 57 based on the motor control signal from the DC unit 105. In this embodiment, the PF motor 57 meshes with a paper feed roller 83, a conveyance drive roller 53, a paper discharge drive roller 55, and a rack 71 (see FIG. 2) formed on the side end of the disc tray 7. It becomes a rotational driving force source of a pinion gear (not shown) that conveys the tray 7. The CR motor driver 107 drives or controls the CR motor 63 based on a motor control signal from the DC unit 105 to reciprocate the carriage 61 in the main scanning direction, or stop and hold it. The head driver 59 drives and controls the recording head 62 based on a head control signal from the MPU 104.

Next, a bellows pump unit as an “air compressor” that sends air pressure to the ink cartridge 16 and pressurizes and supplies the ink in the ink cartridge 16 to the recording head 62 will be described with reference to FIGS. .
FIG. 5 is a cross-sectional view schematically showing an bellows pump unit and an ink pressurization system using the bellows pump unit.

  The bellows pump unit 20 is configured to be able to pressurize and depressurize the pneumatic tube 19 as a “pneumatic path” by expanding and contracting an expandable bellows pump 21 as a “barometric chamber”. The bellows pump unit 20 is an on-off valve composed of a valve body 22 that moves up and down by the rotation of the pressure-increasing and depressing motor 18 as a “valve element driving force source” and a valve seat 23 disposed in the bellows pump 21. The bellows pump 21 is extended or compressed by the valve body 22 so that the internal air is compressed and pressurized or opened and depressurized. The valve body 22 is supported in a state where the rotating shaft 24 and the rotating shaft 25 are screwed into the screw hole 223 and the screw hole 224 formed in the valve body 22, respectively. The rotating shaft 24 and the rotating shaft 25 are rotatably supported, and the gear 241 attached to the rotating shaft 24 and the gear 251 attached to the rotating shaft 25 are attached to the rotating shaft of the pressure increasing / decreasing motor 18. The gear 18 is in gear engagement. The rotation of the pressure increasing / decreasing motor 18 causes the rotation shaft 24 and the rotation shaft 225 to rotate in the same rotation direction by the same rotation amount, thereby moving the valve body 22 in the compression direction or the expansion direction of the bellows pump 21. It is supposed to be. The air pressure of the bellows pump 21 is sent to each ink cartridge 16 through the pneumatic tube 19. Each ink cartridge 16 is configured such that the ink filled therein is pressurized and delivered to the ink tube 171 by the air pressure delivered from the bellows pump 21.

  The bellows pump unit 20 includes an initial pressurization position sensor 26 as “initial pressurization position detection means” for detecting that the valve body 22 has moved to the “initial pressurization position”, and a valve body 22 having a “pressurization limit”. A pressurization limit position sensor 27 is disposed as “pressurization limit position detection means” for detecting the movement to “position”. The initial pressure position sensor 26 and the pressure limit position sensor 27 are sensors having mechanical contacts, and a part of the valve body 22 pushes the mechanical pressure contacts of the initial pressure position sensor 26 or the pressure limit position sensor 27. By moving, a mechanical contact is constructed. Detection signals from the initial pressure position sensor 26 and the pressure limit position sensor 27 are input to the recording control unit 100. Here, the “initial pressurizing position” is set in advance as a movement limit position of the valve element 22 in the extension direction of the bellows pump 21 (the direction opposite to the compression direction), and starts an operation of compressing and pressurizing the bellows pump 21. It is positioned as the starting position. On the other hand, the “pressurization limit position” is set in advance as the movement limit position of the valve body 22 in the compression direction of the bellows pump 21. When the valve body 22 moves to the “pressurization limit position”, the valve body 22 is once moved in the extending direction of the bellows pump 21 to open and depressurize the bellows pump 21, and the valve body 22 is moved to the “initial pressurization position”. After the movement, the valve body 22 is moved again in the compression direction of the bellows pump 21 to repressurize the air of the bellows pump 21. In the bellows pump unit 20, an air pressure sensor 28 as a “pressure detecting means” for detecting the pressure of the bellows pump 21 is disposed in the air pressure tube 19. The air pressure sensor 28 is a pressure sensor such as a photo reflector. A detection signal from the air pressure sensor 28 is input to the recording control unit 100. The recording control unit 100 having a control function as the “liquid pressure control device” according to the present invention includes the position of the valve body 22 detected by the initial pressurization position sensor 26 and the pressurization limit position sensor 27, and the air pressure. Based on the bellows pump 21 (pressure in the pneumatic tube 19) detected by the sensor 28, the pressure adjusting motor 18 is controlled to increase or decrease the ink supply pressure from each ink cartridge 16 to the recording head 62.

FIG. 6 is a cross-sectional view schematically showing the bellows pump unit 20 and the ink pressurization system using the bellows pump unit 20, and the valve body 22 has started to move from the initial pressurizing position in the compression direction of the bellows pump 21. It shows the state.
When the pressure increasing / decreasing motor 18 is rotated in the rotation direction indicated by reference sign AF, the gear 18 rotates in the rotation direction indicated by reference sign AF, and the rotation shaft 24 is rotated via the gear 241 engaged with the gear 18. The rotary shaft 25 rotates in the rotational direction indicated by the reference symbol CF, and the rotary shaft 25 rotates in the rotational direction indicated by the reference symbol BF via the gear 251 that is also engaged with the gear 18. As a result, the valve body 22 moves in the direction in which the bellows pump 21 is compressed (the direction indicated by the symbol F), and the contacted portion 221 of the valve body 22 and the valve seat 23 come into contact with each other. A ring-shaped rubber member 231 is disposed on the surface of the valve seat 23 on which the abutted portion 221 abuts. The rubber member 231 is in close contact with the abutted portion 221 so that the valve body 22 is initially pressurized. The inside of the bellows pump 21 that has been opened in the position is in a sealed state.

FIG. 7 is a cross-sectional view schematically showing the bellows pump unit 20 and an ink pressurization system using the bellows pump unit 20, and the valve body 22 is further connected to the bellows pump 21 in a state where the inside of the bellows pump 21 is sealed. It shows the state moved in the compression direction.
In a state where the inside of the bellows pump 21 is hermetically sealed, the pressure increasing / decreasing motor 18 is further rotated in the rotation direction indicated by reference sign AF, so that the valve body 22 is compressed in the compression direction of the bellows pump 21 (direction indicated by reference sign F). The air in the sealed bellows pump 21 is compressed and pressurized, and the air pressure (symbol AP) delivered to the pneumatic tube 19 is pressurized. As a result, the inside of each ink cartridge 16 is pressurized, and the ink supply pressure (symbol LP) from each ink cartridge 16 is pressurized. When the ink supply pressure from each ink cartridge 16 reaches the desired ink supply pressure, the rotation of the pressure increasing / decreasing motor 18 is stopped and the air pressure of the bellows pump 21 is maintained. Further, when the air pressure of the bellows pump 21 is lowered to a predetermined air pressure or less due to the ink ejection from the recording head 62, the pressure increasing / decreasing motor 18 is rotated again in the rotation direction indicated by the symbol AF, and the bellows pump 21 Pressurize air pressure. In this way, based on the air pressure of the bellows pump 21 detected by the air pressure sensor 28, pressure control and holding control of the air pressure of the bellows pump 21 is performed, and the ink supply pressure from each ink cartridge 16 to the recording head 62 is predetermined. The ink supply pressure is maintained.
The predetermined air pressure is set to an air pressure at which the ink supply pressure from the ink cartridge 16 to the recording head 62 is the upper limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained.

FIG. 8 is a cross-sectional view schematically showing the bellows pump unit and the ink pressurization system using the bellows pump unit. In the state where the inside of the bellows pump 21 is sealed, the valve body 22 is further compressed by the bellows pump 21. It shows a state in which the valve body 22 is moved to the pressurization limit position.
When the valve body 22 moves to the pressurization limit position, the bellows pump 21 cannot be compressed any more. Therefore, when the air pressure of the bellows pump 21 drops below a predetermined pressure in this state, the valve body 22 is temporarily stopped. After moving to the initial pressurizing position, the bellows pump 21 is compressed again by the valve body 22. In this embodiment, the pressurization limit position is that of the bellows pump 21 after the continuous ink ejection has been performed on the maximum size recording paper P in the ink jet recording apparatus 50 with the movement position of the valve body 22 fixed. The pressure drop width is set in advance as a movement limit position in the compression direction of the valve body 22 such that the pressure drop width is less than the pressure difference between the upper limit value and the lower limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained. The pressure decrease width of the bellows pump 21 at the pressurization limit position of the valve body 22 becomes smaller as the volume of air of the bellows pump 21 at the pressurization limit position of the valve body 22 becomes larger. The bellows so that the pressure drop width of the bellows pump 21 after the continuous ink ejection to the recording paper P is sufficiently smaller than the pressure difference between the upper limit value and the lower limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained. What is necessary is just to set the magnitude | size of the pump 21, and the pressurization limit position of the valve body 22. FIG. As a result, continuous ink ejection onto the recording paper P can be performed without interruption, and a stable ink supply pressure can always be maintained with high accuracy during continuous ink ejection onto the recording paper P. Therefore, it is possible to reduce a decrease in ink ejection accuracy due to variations or fluctuations in the ink supply pressure to the recording head 62. In addition, since continuous ink ejection onto the maximum size recording paper P in the ink jet recording apparatus 50 can be performed without being interrupted, a decrease in ink ejection throughput can be prevented.

FIG. 9 is a cross-sectional view schematically showing the bellows pump unit 20 and an ink pressurization system using the bellows pump unit 20, and the valve body 22 is further connected to the bellows pump 21 in a state where the inside of the bellows pump 21 is sealed. This shows a state in which the valve body 22 is moved to the pressurization limit position.
From the time when the valve body 22 reaches the pressurization limit position, the motor 18 for pressure increase / decrease is rotated in the reverse rotation direction (rotation direction indicated by the symbol AR), so that the gear 18 is engaged with the gear 241 via the gear 241. Thus, the rotation shaft 241 rotates in the rotation direction indicated by the reference symbol CR, and the rotation shaft 25 rotates in the rotation direction indicated by the reference symbol BR via the gear 251 that is also gear-engaged with the gear 18. As a result, the valve body 22 moves in the direction in which the bellows pump 21 extends (the direction indicated by the symbol R), and the contacted portion 221 of the valve body 22 and the valve seat 23 are separated from each other. The rubber member 231 that has been in close contact with the contacted portion 221 of the valve seat 23 is separated from the contacted portion 221, and the sealed bellows pump 21 is opened. Air flows into the bellows pump 21 from the gap between the valve body 22 and the valve seat 23, and the air of the bellows pump 21 that has been sealed is reduced to atmospheric pressure at a stretch and is sent to the pneumatic tube 19. AP) is depressurized to atmospheric pressure. Thereby, the inside of each ink cartridge 16 is depressurized, and the ink supply pressure (symbol LP) from each ink cartridge 16 is depressurized to substantially atmospheric pressure. Then, when the valve body 22 is further moved in the extending direction of the bellows pump 21 (direction indicated by the reference symbol R), the locking portion 222 of the valve body 22 and the valve seat 23 are engaged with each other. Due to the movement in the extending direction (direction indicated by R), the valve seat 23 is pulled while the air flows into the bellows pump 21 from the gap between the valve body 22 and the valve seat 23, and the bellows pump 21 is extended. Go.

The above is the schematic configuration of the ink jet recording apparatus 50. Hereinafter, the ink supply pressure from each ink cartridge 16 to the recording head 62 by the recording control unit 100 having the control function as the “liquid pressure control apparatus” according to the invention is described. Control will be described.
FIG. 10 is a flowchart showing an “initial pressurization control procedure” of air pressure in the bellows pump unit 20.
The initial pressurization control procedure is such that, for example, immediately after the power of the ink jet recording apparatus 50 is turned from OFF to ON, the ink supply pressure in a state where the ink supply pressure is reduced below a predetermined pressure before executing the recording is increased to the predetermined pressure. This is the procedure executed when
First, it is determined whether or not the detection state of the valve element 22 by the initial pressure position sensor 26 is ON (step S1). When the initial pressurizing position sensor 26 is in an OFF state, that is, when the valve body 22 is not in the initial pressurizing position (No in Step S1), the valve is operated while the bellows pump 21 is depressurized by the “depressurization processing control procedure” described later. The body 22 is moved to the initial pressure position (step S2). In the decompression process control procedure (step S2), it is determined whether or not an error has occurred (step S3). If an error has occurred (Yes in step S3), the procedure is directly performed as a fatal error. End (FATAL ERROR). On the other hand, if no error has occurred in the decompression process control procedure (step S2) (No in step S3), or if the initial pressure sensor 26 is in the ON state in step S1 ( If the valve body 22 is in the initial pressurizing position, the air pressure of the bellows pump 21 is increased to a predetermined pressure by the “pressurizing process control procedure” described later (step S4). In the pressurization processing control procedure (step S4), it is determined whether or not an error has occurred (step S5). If an error has occurred (Yes in step S5), the procedure is terminated as a fatal error. (FATAL ERROR). If no error has occurred in the pressurizing process control procedure (step S4) (No in step S5), a “pressure maintenance process control procedure” described later is started and the procedure is terminated (step S4). S6).

  Note that the fatal error (FATAL ERROR) in this embodiment means an error that cannot be restored by power ON / OFF in the ink jet recording apparatus 50. When a fatal error occurs, the control unit 100 stores an abnormal code in the nonvolatile memory 109. In addition, when the ink jet recording apparatus 50 is powered on, the recording control unit 100 refers to whether or not an abnormal code is written in the nonvolatile memory 109. When an abnormal code is written in the non-volatile memory 109, the ink supply pressure increase / decrease control is stopped, and the recording on the label surface of the recording paper P or the optical recording disk D cannot be performed at all. The apparatus 50 is controlled.

FIG. 11 is a flowchart showing the “decompression process control procedure” of air pressure in the bellows pump unit 20.
First, reverse rotation drive (rotation drive in the rotation direction indicated by symbol AR in FIG. 9) of the pressure increasing / decreasing motor 18 of the bellows pump unit 20 is started (step S11), and the initial pressure position sensor 26 detects the ON state. It is determined whether or not (step S12). If the initial pressurization position sensor 26 has not detected the ON state (No in step S12), that is, if it is not detected that the valve element 22 has moved to the initial pressurization position, “abnormality detection” described later. In the “processing control procedure”, it is determined whether or not a sensor error has occurred (step S14). If a sensor error has occurred (Yes in step S14), the pressure-reducing motor 18 is reversely driven at that time. Is stopped (step S15), an error is generated, and the procedure is terminated (ERROR). On the other hand, if no sensor error has occurred (No in step S14), the process returns to step 12, and the reverse rotation driving of the pressure increasing / decreasing motor 18 is continued. When the initial pressure position sensor 26 detects the ON state (Yes in step S12), that is, when it is detected that the valve body 22 has moved to the initial pressure position, The drive rotation is stopped (step S13), and the procedure ends.

FIG. 12 is a flowchart showing the “pressurization process control procedure” of air pressure in the bellows pump unit 20.
First, the normal rotation drive (rotation drive in the rotation direction indicated by the reference symbol AF in FIG. 6) of the pressure increasing / decreasing motor 18 of the bellows pump unit 20 is started (step S21), and the pressure limit position sensor 27 is turned on. It is determined whether or not it has been detected (step S22). If the pressurization limit position sensor 27 has not detected the ON state (No in step S22), that is, if it is not detected that the valve element 22 has moved to the pressurization limit position, “abnormality detection” described later. In the “processing control procedure”, it is determined whether or not a sensor error has occurred (step S24). If a sensor error has occurred (Yes in step S24), the normal rotation of the pressure increasing / decreasing motor 18 at that time is determined. The driving is stopped (step S25), an error is generated, and the procedure is terminated (ERROR). On the other hand, if no sensor error has occurred (No in step S24), it is determined whether the air pressure of the bellows pump 21 is insufficient (step S26). If the air pressure of the bellows pump 21 is insufficient (Yes in Step S26), the process returns to Step 22, and the forward / reverse driving of the pressure increasing / decreasing motor 18 is continued. If the air pressure of the bellows pump 21 is not insufficient (No in step S26), the drive rotation of the pressure increasing / decreasing motor 18 is stopped (step S27), and the procedure ends. In step S22, if the pressurization limit position sensor 27 detects the ON state (Yes in step S22), that is, the valve body 22 is in the pressurization limit while the air pressure of the bellows pump 21 is insufficient. If it is detected that the position has been moved to the position, the driving rotation of the pressure increasing / decreasing motor 18 is stopped as it is (step S23), and the procedure ends.

FIG. 13 is a flowchart showing an “abnormality detection process control procedure” for air pressure in the bellows pump unit 20.
This procedure is performed when the pressurizing / depressurizing motor 18 is rotated in either the forward rotation direction or the reverse rotation direction in the above-described decompression process control procedure (FIG. 11) or pressurization process control procedure (FIG. 12). This is the procedure to be executed.
First, when rotating the pressure increasing / decreasing motor 18 in either the forward rotation direction or the reverse rotation direction, a sensor abnormality detection timer is started (step S31), and the rotation direction of the pressure increasing / decreasing motor 18 is the normal direction. It is determined whether or not the direction is a rolling direction (step S32). If the rotation direction of the pressure increasing / decreasing motor 18 is the forward rotation direction (Yes in step S32), then, the count value of the sensor abnormality detection timer activated in step S31 and the abnormality detection as the “predetermined count value” are detected. The time is compared, and it is determined whether or not the count value of the sensor abnormality detection timer has exceeded the abnormality detection time (step S33). If the count value of the sensor abnormality detection timer does not exceed the abnormality detection time (No in step S33), it is determined whether or not the pressurization limit position sensor 27 has detected an ON state (step S34). If the pressurization limit position sensor 27 detects the ON state (Yes in step S34), that is, if the valve body 22 has moved to the pressurization limit position, the procedure is terminated as it is. If the pressurization limit position sensor 27 has not detected the ON state (No in step S34), it is determined whether or not the air pressure of the bellows pump 21 is insufficient (step S35). If the air pressure of the bellows pump 21 is insufficient (Yes in step S35), the process returns to step S33 to continue driving the pressure-inducing / depressurizing motor 18 in the normal rotation direction to further compress and add the bellows pump 21. If the air pressure of the bellows pump 21 is not insufficient (No in step S35), that is, the procedure ends when the air pressure of the bellows pump 21 is increased to a predetermined pressure. In step S33, when the count value of the sensor abnormality detection timer exceeds the abnormality detection time (Yes in step S33), that is, the continuous drive time in the forward rotation direction of the pressure increasing / decreasing motor 18 is the abnormality detection time. If the valve body 22 does not reach the pressurization limit position while the air pressure of the bellows pump 21 is insufficient even if the pressure exceeds the limit, it is determined that either the air pressure sensor 28 or the pressurization limit position sensor 27 is abnormal. Then, a sensor error is generated and the procedure is terminated (sensor ERROR). When a sensor error occurs in the abnormality detection process control procedure, the pressurizing / depressurizing motor 18 is stopped in the rotation in the pressurization process control procedure (FIG. 12) described above. As a result, an excessive force acts on the valve body 22 and the bellows pump unit 20 is damaged, or an excessive pressure is applied to the pneumatic tube 19, the ink cartridge 16, the ink tube 171, or the recording head 62, causing a pneumatic leak. And the risk of ink leakage.

  On the other hand, when the rotation direction of the pressure increasing / decreasing motor 18 is the reverse direction (No in step S32), the count value of the sensor abnormality detection timer is compared with the abnormality detection time as a default value, and the sensor It is determined whether or not the count value of the abnormality detection timer has exceeded the abnormality detection time (step S36). If the count value of the sensor abnormality detection timer does not exceed the abnormality detection time (No in step S36), it is determined whether or not the initial pressure position sensor 26 has detected an ON state (step S36). If the initial pressurization position sensor 26 detects the ON state (Yes in step S36), that is, if the valve body 22 has moved to the initial pressurization position, the procedure is terminated as it is. If the initial pressurization position sensor 26 has not detected the ON state (No in step S36), the process returns to step S36 to continue the drive of the pressurizing / depressurizing motor 18 in the reverse rotation direction, and the valve body 22 is further moved. Move toward the initial pressure position. In step S36, if the count value of the sensor abnormality detection timer exceeds the abnormality detection time (Yes in step S36), that is, the continuous driving time in the reverse direction of the pressure increasing / decreasing motor 18 is set to the abnormality detection time. If it is not detected that the valve body 22 has reached the initial pressurization position even if the value exceeds the initial pressurization position, it is determined that the initial pressurization position sensor 26 is abnormal, a sensor error is generated, and the procedure ends. ERROR). When a sensor error occurs in the abnormality detection process control procedure, the rotation of the pressure increasing / decreasing motor 18 is stopped in the pressure reducing process control procedure (FIG. 11) described above. Thereby, the possibility that an excessive force acts on the valve body 22 and the bellows pump unit 20 is damaged can be reduced.

The above-described abnormality detection time as the “predetermined count value” is, for example, a count value corresponding to an operation time of the pressure increasing / decreasing motor 18 sufficient for the valve body 22 to move from the initial pressure position to the pressure limit position. Set to The required time when the valve body 22 moves from the initial pressurization position to the pressurization limit position with the maximum load is such that the pressurizing / depressurizing motor 18 is continuously operated at a constant driving speed while the bellows pump unit 20 is in a normal state. Thus, the maximum time when the valve body 22 is moved from the initial pressurizing position to the pressurizing limit position without stopping is reached . Therefore, by setting the count value corresponding to this time as the abnormality detection time, when the count value of the abnormality detection timer exceeds the abnormality detection time, the air pressure sensor 28, the pressurization position detection sensor 27, and the initial pressurization. It can be determined in the shortest time that an abnormality has occurred in any of the position sensors 26. As a result, the time during which the pressure increasing / decreasing motor 18 operates in a state in which any one of the air pressure sensor 28, the pressurizing position detection sensor 27, and the initial pressurizing position sensor 26 has occurred is reduced to a minimum. It becomes possible.

FIG. 14 is a flowchart showing a first embodiment of the “pressure maintenance control procedure” of air pressure in the bellows pump unit 20.
The said procedure is a procedure started in the initial pressurization control procedure (FIG. 10) mentioned above.
First, it is determined whether there is a decompression control condition (step S41). Here, the decompression control condition is that when the power switch 35 is operated while the power supply of the ink jet recording apparatus 50 is ON, the operation of the ink jet recording apparatus 50 by the user is not performed for 3 minutes or more. When the control state of 50 shifts to the power saving mode and when the open / close cover 3 of the ink cartridge unit 15 in which the plurality of ink cartridges 16 are accommodated is open, any of these conditions is satisfied. If there is a pressure reduction control condition. When the recording control unit 100 shifts to the power saving mode, the recording control unit 100 cuts off the output of the 42V system such as the PF motor driver 106, the CR motor driver 107, and the head driver 108, chops the 42V power supply, and the microcomputer system such as the MPU 104. A DC-DC converter (not shown) that supplies 5 V power is reduced to a voltage (about 20 V) at which it can operate to save power.

  If there is a decompression control condition (Yes in step S41), the decompression process control procedure (FIG. 11) is executed (step S50), and it is determined whether or not an error has occurred in the decompression process control procedure (step S50). (Step S51). If an error has occurred (Yes in step S51), the procedure is terminated as it is as a fatal error (FATAL ERROR). On the other hand, if an error has not occurred (No in step S51), the standby state (Wait) is kept as it is until the pressure reduction control condition is not satisfied (step S52), and the pressure reduction control condition is not satisfied. When the state is reached, the initial pressurization control procedure is activated (step S49), and the procedure is terminated. Here, the state where the decompression control condition is not satisfied is a state where the opening / closing cover 3 is closed and an operation of the ink jet recording apparatus 50 by the user is performed. In step S41, when the decompression control condition is satisfied due to the operation of the power switch 35 while the power of the ink jet recording apparatus 50 is ON, after executing the decompression process control procedure (step S50), If no error has occurred at the time of step S51, the power-off control of the ink jet recording apparatus 50 is executed as it is.

  Thus, when the ink cartridge 16 can be attached / detached with the opening / closing cover 3 opened, the ink supply pressure from the ink cartridge 16 can be reduced to atmospheric pressure when the opening / closing cover 3 is opened. The risk of ink leakage when the cartridge 16 is attached or detached can be reduced. In addition, when the control state of the ink jet recording apparatus 50 shifts to the power saving mode or when the power of the ink jet recording apparatus 50 is turned off, the ink supply pressure applied to the recording head 62 can be reduced to atmospheric pressure. While the control state of the ink jet recording apparatus 50 is shifted to the power saving mode and when the power of the ink jet recording apparatus 50 is turned off, the life of the recording head 62 and the ink tube 171 due to the ink supply pressure from the ink cartridge 16 is reduced. It is possible to reduce the decrease and the risk of ink leakage when the ink cartridge 16 is attached or detached.

  If there is no decompression control condition in step S41 (No in step S41), it is then determined whether the air pressure of the bellows pump 21 is insufficient (step S42). If the air pressure of the bellows pump 21 is not insufficient (No in step S42), the process returns to step S41. If the air pressure of the bellows pump 21 is insufficient (Yes in step S42), the pressurizing process described above. By the control procedure (FIG. 12), the air pressure of the bellows pump 21 is increased to a predetermined pressure (step S43). After pressurizing the air pressure of the bellows pump 21 to a predetermined pressure, it is determined whether or not the pressurization limit position sensor is in an ON state (step S44). If the pressurization limit position sensor 27 has not detected the ON state (No in step S44), that is, if it has not been detected that the valve element 22 has moved to the pressurization limit position, the above-described abnormality In the detection process control procedure (FIG. 13), it is determined whether or not a sensor error has occurred (step S45). If a sensor error has not occurred (No in step S45), the process returns to step S41. If a sensor error has occurred (Yes in step S45), the procedure ends as a fatal error (FATAL • ERROR).

  On the other hand, when the pressurization limit position sensor 27 detects the ON state (Yes in step S44), that is, when it is detected that the valve element 22 has moved to the pressurization limit position, In the pressure processing control procedure (step S43), it is determined whether an error has occurred (step S46). If an error has occurred (Yes in step S46), the procedure is terminated as a fatal error (FATAL ERROR), and if no error has occurred (No in step S46), the recording paper It is determined whether or not recording on the label surface of P or optical recording disk D is being executed (step S47). If recording on the label surface of the recording paper P or the optical recording disk D is not being executed (No in step S47), the above-described initial pressurization control procedure (FIG. 10) is activated to re-activate the air pressure of the bellows pump 21. Pressure is applied (step S49). If recording on the label surface of the recording paper P or the optical recording disk D is being executed (Yes in step S47), the process waits until the recording being executed is completed (step S48) and executed. When the recording is completed, the above-described initial pressurization control procedure (FIG. 10) is activated to repressurize the air pressure of the bellows pump 21 (step S49).

  As described above, the pressurization limit position of the valve body 22 is the bellows after continuous ink ejection is performed on the maximum size recording paper P in the ink jet recording apparatus 50 with the movement position of the valve body 22 fixed. The pressure drop width of the pump 21 is set in advance as a movement limit position in the compression direction of the valve body 22 such that the pressure drop width of the pump 21 is less than the pressure difference between the upper limit value and the lower limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained. . For this reason, even when the valve body 22 has moved to the pressurization limit position, the air pressure of the bellows pump 21 is maintained at an air pressure close to the upper limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained. If so, the ink supply pressure at which desired ink ejection characteristics can be obtained without maintaining the air pressure of the bellows pump 21 during the recording on the recording paper P of the maximum size in the ink jet recording apparatus 50 is maintained. It can be executed as it is. Therefore, recording is being performed when the valve body 22 moves to the pressurization limit position while maintaining the air pressure of the bellows pump 21 at a predetermined air pressure (the upper limit value of the ink supply pressure at which desired ink ejection characteristics can be obtained). In this case (Yes in step S47), the recording on the recording paper P is continued without interrupting the recording, and the initial pressurization control procedure (FIG. 10) is started after the ongoing recording is completed. Repressurization of the bellows pump 21 can be executed. As a result, recording on the label surface of the recording paper P or the optical recording disk D can be performed without being interrupted, and a stable ink supply pressure can always be maintained with high accuracy during recording. Therefore, it is possible to reduce a decrease in ink ejection accuracy due to variations or fluctuations in the ink supply pressure to the recording head 62. Further, since the recording on the label surface of the recording paper P or the optical recording disk D can be performed without being interrupted, a decrease in the recording execution throughput due to repressurization of the air pressure of the bellows pump 21 is prevented. can do.

FIG. 15 is a flowchart showing a second embodiment of the “pressure maintenance control procedure” for air pressure in the bellows pump unit 20.
This procedure is a procedure that is activated in the above-described initial pressurization control procedure (FIG. 10), and is a procedure that is repeatedly executed at a predetermined cycle after activation.
First, it is determined whether or not the air pressure of the bellows pump 21 is insufficient (step S61). If the air pressure of the bellows pump 21 is not insufficient (No in step S61), the procedure is terminated as it is. On the other hand, if the air pressure of the bellows pump 21 is insufficient (Yes in step S61), it is then determined whether or not the initial pressure position sensor 26 has detected an ON state (step S62). If the initial pressure position sensor 26 has not detected the ON state (No in step S62), that is, if it has not been detected that the valve element 22 has moved to the initial pressure position, the pressure reduction described above is performed. The process control procedure (FIG. 11) is executed (step S63), and it is determined whether or not an error has occurred in the decompression process control procedure (step S63) (step S64). If an error has occurred (Yes in step S64), the procedure is terminated as it is as a fatal error (FATAL ERROR). On the other hand, when the initial pressurization position sensor 26 detects the ON state (Yes in step S62), that is, when it is detected that the valve body 22 has moved to the initial pressurization position, or the decompression process control procedure If no error has occurred in (step S63) (No in step S63), the normal-rotation drive of the booster / depressurization motor 18 of the bellows pump unit 20 (in the rotational direction indicated by symbol AF in FIG. 6). Rotation drive) is started (step S65). Subsequently, it is determined whether or not the pressurization limit position sensor 27 has detected an ON state (step S66). If the pressurization limit position sensor 27 has not detected the ON state (No in step S66), that is, if it is not detected that the valve element 22 has moved to the pressurization limit position, the above-described abnormality detection processing is performed. In the control procedure (FIG. 13), it is determined whether or not a sensor error has occurred (step S67). If a sensor error has occurred (Yes in step S67), the forward rotation driving of the pressure-increasing / depressurizing motor 18 is stopped at that time (step S70), and the procedure ends as a fatal error (FATAL ERROR). .

  On the other hand, if no sensor error has occurred (No in step S67), it is determined whether the air pressure of the bellows pump 21 is insufficient (step S68). When the air pressure of the bellows pump 21 is insufficient (Yes in Step S68), the process returns to Step 66, and the forward drive of the pressure-increasing / depressurizing motor 18 is continued. Then, if the air pressure of the bellows pump 21 is not insufficient (No in step S68), the driving rotation of the pressure increasing / decreasing motor 18 is stopped (step S27), and the procedure ends. If the pressurization limit position sensor 27 detects an ON state in step S66 (Yes in step S66), that is, the valve body 22 is initially applied while the air pressure of the bellows pump 21 is insufficient. If it is detected that the air pressure of the bellows pump 21 has moved from the pressure position to the pressurization limit position without increasing above the predetermined air pressure, either the air pressure of the bellows pump unit 20 or the ink tube 171 is detected. It is determined that a pressure leak has occurred, and at that time, the normal rotation driving of the pressure increasing / decreasing motor 18 is stopped (step S70), and the procedure ends as a fatal error (FATAL ERROR).

  That is, the fact that the pressure of the bellows pump 21 does not increase despite the valve body 22 being moved from the initial pressurization position to the pressurization limit position in the compression direction of the bellows pump 21 means that the air pressure of the bellows pump unit 20 is increased. In addition, there is a high possibility that a pressure leak has occurred in either of the ink tubes 171 and there is a possibility that the ink in the ink cartridge 16 has leaked out. If ink leakage actually occurs, it is necessary to prevent the ink leakage from expanding. Therefore, at that time, the forward rotation driving of the pressure increasing / decreasing motor 18 is stopped, and the procedure is ended as a fatal error. Thereby, further ink leakage can be prevented, so that the amount of ink leakage when ink leakage occurs in the ink tube 171 can be reduced to the minimum. Further, when it is determined that a pressure leak has occurred in either the air pressure of the bellows pump unit 20 or the ink tube 171, if the driving rotation of the pressure increasing / decreasing motor 18 is stopped in that state, the bellows at that time point is stopped. Further slight ink leakage may occur while the pressure of the pump 21 is reduced to atmospheric pressure. Therefore, when it is determined that a pressure leak has occurred in either the air pressure of the bellows pump unit 20 or the ink tube 171, the decompression control of the bellows pump unit 20 is executed, and then the driving rotation of the pressure increasing / decreasing motor 18 is performed. May be stopped. As a result, slight ink leakage after stopping the driving rotation of the pressure increasing / decreasing motor 18 can be prevented, so that the ink leakage amount when the ink leakage occurs in the ink tube 171 is reduced to a smaller amount. It can be said that this is a more preferable embodiment.

FIG. 16 is a flowchart showing a third embodiment of the “pressure maintenance control procedure” of air pressure in the bellows pump unit 20.
This procedure is a procedure that is activated in the above-described initial pressurization control procedure (FIG. 10), and is a procedure that is repeatedly executed at a predetermined cycle after activation.
First, it is determined whether or not the air pressure of the bellows pump 21 is insufficient (step S71). If the air pressure of the bellows pump 21 is not insufficient (No in step S71), the procedure is terminated as it is. On the other hand, if the air pressure of the bellows pump 21 is insufficient (Yes in step S71), it is then determined whether or not the pressurization limit position sensor 27 has detected an ON state (step S72). When the pressurization limit position sensor 27 detects the ON state (Yes in step S72), that is, when it is detected that the valve element 22 has moved to the pressurization limit position, the pressure reduction described above. The process control procedure (FIG. 11) is executed (step S73), and it is determined whether or not an error has occurred in the decompression process control procedure (step S73) (step S74). If an error has occurred (Yes in step S74), the procedure is terminated as it is as a fatal error (FATAL ERROR). On the other hand, if the pressurization limit position sensor 27 has not detected the ON state (No in step S72), that is, if it has not been detected that the valve element 22 has moved to the pressurization limit position, or the decompression process control procedure If no error has occurred in (Step S73) (No in Step S74), it is determined whether or not the initial pressure position sensor 26 is in an ON state (Step S75). If the initial pressurization position sensor 26 has not detected the ON state (No in step S75), that is, if it has not been detected that the valve body 22 has moved to the initial pressurization position, it is used for pressurization / decompression. The forward rotation drive of the motor 18 is started (step S77). On the other hand, when the initial pressure position sensor 26 detects the ON state (Yes in step S75), that is, when it is detected that the valve body 22 has moved to the initial pressure position, the ink is detected. The leak detection timer is started (step S76), and the normal rotation drive of the pressure increasing / decreasing motor 18 is started (step S77).

  Subsequently, it is determined whether or not the pressurization limit position sensor 27 has detected an ON state (step S78). If the pressurization limit position sensor 27 has not detected the ON state (No in Step S78), it is determined whether or not a sensor error has occurred in the above-described abnormality detection process control procedure (FIG. 13) (Step S78). S79). If a sensor error has occurred (Yes in step S79), the forward rotation drive of the pressure increasing / decreasing motor 18 is stopped at that time (step S82), and the procedure is terminated as a fatal error (FATAL ERROR). . On the other hand, if no sensor error has occurred (No in step S79), it is determined whether the air pressure of the bellows pump 21 is insufficient (step S80). When the air pressure of the bellows pump 21 is insufficient (Yes in step S80), the process returns to step 78, and the forward rotation driving of the pressure increasing / decreasing motor 18 is continued. If the air pressure of the bellows pump 21 is not insufficient (No in step S80), the drive rotation of the pressure increasing / decreasing motor 18 is stopped (step S81), and the procedure ends. In step S78, if the pressurization limit position sensor 27 detects the ON state (Yes in step S78), that is, the valve body 22 is initially applied while the air pressure of the bellows pump 21 is insufficient. If it is detected that the pressure has moved from the pressure position to the pressurization limit position, the drive rotation of the pressure increasing / decreasing motor 18 is stopped at that time (step S83).

  Then, while the count value of the ink leakage detection timer started in step S76 moves from the initial pressurization position to the pressurization limit position, the ink ejection is continuously performed with the maximum ejection amount of the recording head 62. It is determined whether or not the count value is smaller than the count value (step S84). The count value of the ink leakage detection timer is equal to or greater than the count value when the ink ejection is continuously executed with the maximum ejection amount of the recording head 62 while the valve body 22 moves from the initial pressure position to the pressure limit position. In that case (No in step S84), the procedure is terminated as it is. On the other hand, the count value of the ink leakage detection timer when the ink jet is continuously executed with the maximum ejection amount of the recording head 62 while the valve body 22 moves from the initial pressurization position to the pressurization limit position. If it is smaller (Yes in step S84), it is determined that a pressure leak has occurred in either the air pressure of the bellows pump unit 20 or the ink tube 171, and at that time, the pressure increasing / decreasing motor 18 is driven forward. Stop (step S70), and end the procedure as a fatal error (FATAL ERROR).

  When the ink ejection is continuously performed with the maximum ejection amount of the recording head 62, the time for the valve body 22 to move from the initial pressure position to the pressure limit position is the air pressure of the bellows pump unit 20 and the supply of ink. This is the shortest theoretical time when the air pressure of the bellows pump unit 20 is supplied to the ink cartridge 16 in a normal state with no leakage of pressure. That is, the pressure of the bellows pump 21 is increased at a faster pace than when the ink ejection is continuously performed with the maximum ejection amount of the recording head 62. Accordingly, the fact that the valve element 22 has moved from the initial pressurization position to the pressurization limit position in a time shorter than the theoretical minimum time described above means that either the air pressure of the bellows pump unit 20 or the ink tube 171 leaks pressure. Is likely to occur, and the ink in the ink cartridge 16 may be leaking. If ink leakage actually occurs, it is necessary to prevent the ink leakage from expanding. Therefore, at that time, the forward rotation driving of the pressure increasing / decreasing motor 18 is stopped, and the procedure is ended as a fatal error. Thereby, further ink leakage can be prevented, so that the amount of ink leakage when ink leakage occurs in the ink tube 171 can be reduced to the minimum. Further, when it is determined that a pressure leak has occurred in either the air pressure of the bellows pump unit 20 or the ink tube 171, if the driving rotation of the pressure increasing / decreasing motor 18 is stopped in that state, the bellows at that time point is stopped. Further slight ink leakage may occur while the pressure of the pump 21 is reduced to atmospheric pressure. Therefore, when it is determined that a pressure leak has occurred in either the air pressure of the bellows pump unit 20 or the ink tube 171, the decompression control of the bellows pump unit 20 is executed, and then the driving rotation of the pressure increasing / decreasing motor 18 is performed. May be stopped. As a result, slight ink leakage after stopping the driving rotation of the pressure increasing / decreasing motor 18 can be prevented, so that the ink leakage amount when the ink leakage occurs in the ink tube 171 is reduced to a smaller amount. It can be said that this is a more preferable embodiment.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

  The present invention can be implemented by a liquid pressure control device that controls the driving force source of the valve body based on the pressure detected by the pressure detection means to control the supply pressure of the liquid from the liquid container to the liquid ejecting head. Yes, it can be used in a liquid ejecting apparatus including the liquid pressure control device.

1 is a perspective view of an ink jet recording apparatus. FIG. 3 is a perspective view of the ink jet recording apparatus with a main body cover removed. 1 is a schematic side sectional view of an ink jet recording apparatus. It is a block diagram of the control part which performs various controls of an ink jet recording device. It is sectional drawing which showed the ink pressurization system by a bellows pump unit. It is sectional drawing which showed the ink pressurization system by a bellows pump unit. It is sectional drawing which showed the ink pressurization system by a bellows pump unit. It is sectional drawing which showed the ink pressurization system by a bellows pump unit. It is sectional drawing which showed the ink pressurization system by a bellows pump unit. It is the flowchart which showed the initial pressurization control procedure of ink supply pressure. 6 is a flowchart illustrating a control process for reducing ink supply pressure. 6 is a flowchart illustrating a pressurization process control procedure for ink supply pressure. It is the flowchart which showed the abnormality detection process control procedure. It is the flowchart which showed 1st Example of the pressure maintenance control procedure. It is the flowchart which showed 2nd Example of the pressure maintenance control procedure. It is the flowchart which showed 3rd Example of the pressure maintenance control procedure.

Explanation of symbols

4 Memory slot cover, 7 Disc tray, 8 Paper cassette, 16 Ink cartridge, 17 Ink tube, 18 Motor for pressure increase / decrease, 19 Pneumatic tube, 20 Bellows pump unit, 21 Bellows pump, 22 Valve body, 26 Initial pressure position Sensor, 27 Pressure limit position sensor, 28 Air pressure sensor, 50 Inkjet recording device, 51 Carriage guide shaft, 52 Platen, 53 Carrying drive roller, 54 Carrying driven roller, 55 Paper ejection driving roller, 56 Paper ejection driven roller, 57 PF motor, 61 carriage, 62 recording head, 63 CR motor, 83 paper feed roller, 101 ROM, 102 RAM, 103 interface unit, 104 MPU, 105 DC unit, 106 PF motor driver, 107 CR motor driver, 108 Head driver, 109 Non-volatile memory, P recording paper, X main scanning direction, Y sub-scanning direction

Claims (3)

A liquid ejecting head for ejecting liquid onto a material to be ejected, a pressure chamber, a valve body for compressing and pressurizing air in the pressure chamber, and an opening / closing valve for the pressure chamber, and moving the valve body in the compression direction the on-off valve is air in the pressure chamber in a state of being closed is issued feed pressurized compressed, the pressure chamber by opening said closing valve by moving the valve body to the compression direction in the opposite direction detecting an air compressor which air is reduced to atmospheric pressure, with the being liquid GaTakashi Hama, a liquid container air pressure whose pressure compressed pressurized by the air compressor is sent, the pressure in the pressure chamber A liquid ejecting apparatus comprising: a pressure detecting unit, wherein the liquid filled in the liquid container is pumped to the liquid ejecting head with a supply pressure corresponding to a pressure of air pressure compressed and pressurized by the air compressor. In the device
The air compressor includes a pressure limit position detecting means for detecting that the valve body has moved to a pressure limit position preset as a movement limit position in the compression direction of the valve body, and a compression direction of the valve body. And an initial pressurizing position detecting means for detecting that the valve body has moved to an initial pressurizing position that is set in advance as a movement limit position in the opposite direction, and based on the pressure detected by the pressure detecting means A liquid pressure control device that controls a driving force source of the valve body to increase or decrease a supply pressure of the liquid from the liquid container to the liquid ejecting head;
A driving force source of said valve body Start at abnormality detection timer starts driving the drive power source is continuously to the movement in the compressing direction and the opposite direction of movement or the valve body in the compression direction of the valve body And count the time during operation
When the movement direction of the valve body is the compression direction, the operation time of the driving force source sufficient for the count value of the abnormality detection timer to move the valve body from the initial pressurization position to the pressurization limit position When the predetermined count value corresponding to is exceeded, the pressure value detected by the pressure detecting means is less than a predetermined pressure, and the moving position of the valve element is detected by the pressurization limit position detecting means. Otherwise, it is determined that one of the pressure detection unit and the pressurization limit position detection unit is abnormal, and the increase / decrease control of the liquid supply pressure is stopped,
When the moving direction of the valve body is opposite to the compression direction, the count value of the abnormality detection timer is a driving force source sufficient to move the valve body from the pressurization limit position to the initial pressurization position. If the movement position of the valve element is not detected by the initial pressurization position detection means when the predetermined count value corresponding to the operation time is exceeded, it is determined that the initial pressurization position detection means is abnormal And stop the increase / decrease control of the supply pressure of the liquid ,
When it is determined that any one of the pressure detection means, the pressurization limit position detection means, and the initial pressurization position detection means is abnormal, an abnormal code is written in a nonvolatile storage medium,
Reference is made to whether or not the abnormal code is written in the nonvolatile storage medium when the liquid ejecting apparatus is turned on. If the abnormal code is written, the increase / decrease control of the liquid supply pressure is stopped. to the liquid pressure control apparatus wherein a. A liquid ejecting apparatus comprising the liquid pressure control apparatus according to claim 1 . A liquid ejecting head for ejecting liquid onto a material to be ejected, a pressure chamber, a valve body for compressing and pressurizing air in the pressure chamber, and an opening / closing valve for the pressure chamber, and moving the valve body in the compression direction the on-off valve is air in the pressure chamber in a state of being closed is issued feed pressurized compressed, the pressure chamber by opening said closing valve by moving the valve body to the compression direction in the opposite direction detecting an air compressor which air is reduced to atmospheric pressure, with the being liquid GaTakashi Hama, a liquid container air pressure whose pressure compressed pressurized by the air compressor is sent, the pressure in the pressure chamber A liquid ejecting apparatus comprising: a pressure detecting unit, wherein the liquid filled in the liquid container is pumped to the liquid ejecting head with a supply pressure corresponding to a pressure of air pressure compressed and pressurized by the air compressor. In the device
The air compressor includes a pressure limit position detecting means for detecting that the valve body has moved to a pressure limit position preset as a movement limit position in the compression direction of the valve body, and a compression direction of the valve body. And an initial pressurizing position detecting means for detecting that the valve body has moved to an initial pressurizing position that is set in advance as a movement limit position in the opposite direction, and based on the pressure detected by the pressure detecting means A liquid pressure control program for controlling a driving force source of the valve body to cause a computer to execute control to increase or decrease the supply pressure of the liquid from the liquid container to the liquid ejecting head,
A driving force source of said valve body Start at abnormality detection timer starts driving the drive power source is continuously to the movement in the compressing direction and the opposite direction of movement or the valve body in the compression direction of the valve body The procedure to count the time during the operation ,
When the movement direction of the valve body is the compression direction, the operation time of the driving force source sufficient for the count value of the abnormality detection timer to move the valve body from the initial pressurization position to the pressurization limit position When the predetermined count value corresponding to is exceeded, the pressure value detected by the pressure detecting means is less than a predetermined pressure, and the moving position of the valve element is detected by the pressurization limit position detecting means. If not, a procedure for determining that any one of the pressure detection unit and the pressurization limit position detection unit is abnormal and stopping the increase / decrease control of the supply pressure of the liquid,
When the moving direction of the valve body is opposite to the compression direction, the count value of the abnormality detection timer is a driving force source sufficient to move the valve body from the pressurization limit position to the initial pressurization position. If the movement position of the valve element is not detected by the initial pressurization position detection means when the predetermined count value corresponding to the operation time is exceeded, it is determined that the initial pressurization position detection means is abnormal And stopping the increase / decrease control of the supply pressure of the liquid ,
When it is determined that any one of the pressure detection unit, the pressurization limit position detection unit, and the initial pressurization position detection unit is abnormal, a procedure for writing an abnormal code to a nonvolatile storage medium;
Reference is made to whether or not the abnormal code is written in the nonvolatile storage medium when the liquid ejecting apparatus is turned on. If the abnormal code is written, the increase / decrease control of the liquid supply pressure is stopped. and a procedure of, fluid pressure control program, characterized in that.

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