JP2008162202A - Inkjet recording apparatus, its driving method, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus which can keep the life of a diaphragm longer, while suppressing the occurrence of clogging of a nozzle. <P>SOLUTION: This inkjet recording apparatus comprises: an inkjet head 14 which is provided with a plurality of nozzles 40 for ejecting ink, a plurality of pressurization chambers 45 communicating with the nozzles 40, respectively, and the plurality of diaphragms 42 for applying vibrations to the ink infilled into the pressurization chambers 45; an HDD 5 for accumulating the use history of the plurality of nozzles on the basis of image data; and a control unit 50 which applies vibrations to the diaphragm 42 corresponding to the nozzle 40 having a nonuse time set as long as/longer than a predetermined time, on the basis of a first driving waveform for nonejection, before a printing operation. The first driving waveform for nonejection is a waveform which makes the diaphragm 42 subjected to the vibrations with a magnitude preventing the ejection of the ink from the nozzle 40. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording using an ink jet head in a recording apparatus such as a facsimile, a copying machine, and a printer.

  2. Description of the Related Art A recording apparatus such as a facsimile, a copying machine, and a printer is configured to form an image on a recording medium such as paper, cloth, and OHP sheet and perform recording. The recording method is classified into an ink jet method, a wire dot method, a thermal method, and the like.

  The ink jet system is further classified into a serial type in which recording is performed while the recording head scans the recording medium, and a line head type in which recording is performed by a recording head having a recording area equal to or larger than the width of the recording medium fixed to the apparatus main body. .

  In such an ink jet recording apparatus, the ink viscosity changes depending on the environment, the nozzles are clogged, and the ink droplets do not fly straight due to the clogging, resulting in the positional deviation of the dots. In some cases, image defects such as white streaks appear. This change in ink viscosity is more likely to occur as the unused time is longer.

For such a problem, there is provided means for generating and outputting in time series a first drive waveform for ejecting ink droplets and a second drive waveform for vibrating the meniscus (ink liquid level) without ejecting ink droplets. Inkjet recording apparatuses are disclosed (for example, see Patent Document 1). In this ink jet recording apparatus, the first drive waveform is selected according to the print signal, and ink is ejected to perform printing. In addition, the second drive waveform is selected according to the meniscus vibration selection signal independent of the print signal, and the diaphragm is vibrated by simultaneously applying a voltage to a plurality of electrodes, the meniscus vibrates, and clogging is eliminated. Is done. In this way, vibrating the meniscus is called swinging or flushing.
JP 2002-144544 A

  As described above, in addition to the application time of the first vibration waveform, the time for which the vibration plate is deformed becomes longer by adding the application time of the second vibration waveform. In some cases, the ink ejection speed decreases.

  In this way, the ink jet recording apparatus described in Patent Document 1 cannot discriminate clogged nozzles even though the diaphragm has a lifetime, so that all nozzles including nozzles that are not clogged are included. On the other hand, the second drive waveform is uniformly applied.

  In this way, when trying to prevent clogging, vibration due to the second drive waveform is also applied to the vibration plate of the nozzle having a high printing frequency, thereby shortening the life of the vibration plate.

  In view of the problems of the conventional ink jet recording apparatus, the present invention provides an ink jet recording apparatus and an ink jet recording apparatus driving method capable of keeping the life of a diaphragm longer while suppressing the occurrence of nozzle clogging. The purpose is to provide.

In order to achieve the above object, the first present invention provides:
An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber;
A history accumulating unit for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A control unit that vibrates,
The first non-ejection drive waveform is an inkjet recording apparatus that is a waveform that imparts vibration to the diaphragm so as not to eject the ink from the nozzles.

The fifth aspect of the present invention is
The control unit has an amplitude smaller than the first non-ejection drive waveform for the diaphragm corresponding to the nozzle whose unused time is less than the first predetermined time before the printing operation. It is the ink jet recording apparatus according to the first aspect of the present invention, which performs control to vibrate based on a second non-ejection driving waveform.

The sixth aspect of the present invention
The inkjet head is divided into a plurality of blocks for each of a plurality of nozzles,
The control unit is
Before the printing operation, control is performed to vibrate all the diaphragms of the block having the nozzles whose unused time is equal to or longer than the first predetermined time based on the first non-ejection drive waveform. The inkjet recording apparatus according to the first aspect of the invention is performed.

The tenth aspect of the present invention is
An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber; Ink jet recording apparatus driving method,
A history accumulating step for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. Equipped with a control process to vibrate,
The first non-ejection drive waveform in the control step is a method for driving an ink jet recording apparatus, wherein the first non-ejection drive waveform is a waveform that imparts vibration to the diaphragm so as not to eject the ink from the nozzles.

The eleventh aspect of the present invention is
In the driving method of the ink jet recording apparatus of the tenth aspect of the present invention,
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A program for causing a computer to execute a control process for causing vibration.

The twelfth aspect of the present invention is
A recording medium on which the program of the eleventh aspect of the present invention is recorded, which is a recording medium that can be processed by a computer.

  According to the present invention, it is possible to provide an ink jet recording apparatus and a method for driving the ink jet recording apparatus that can suppress the occurrence of nozzle clogging and can keep the life of the diaphragm longer.

  Hereinafter, an ink jet printer as an example of an ink jet recording apparatus according to the present invention will be described with reference to the drawings.

(Embodiment 1)
The ink jet printer according to the first embodiment of the present invention will be described below.

  First, the overall configuration of the ink jet printer according to the present embodiment will be described.

  FIG. 1 is a front structural view of an ink jet printer 1 according to the present embodiment. The ink jet printer 1 includes a paper feeding cassette 11 disposed at a lower portion, an ink tank 12 disposed above the paper feeding cassette 11, a transport belt 13 disposed above the ink tank 12, and a transport belt 13. The inkjet head 14 is provided.

  A sheet conveyance path 16 for conveying sheets from the sheet feeding cassette 11 to the conveyance belt 13 is formed in the vertical direction at the right end of the inkjet printer 1. The paper transport path 16 is constituted by a guide plate.

  The paper feed cassette 11 stores paper P, which is a recording medium on which printing is performed. The paper feed cassette 11 is provided with a paper feed roller 21 for feeding paper on the paper transport path 16 side. Yes. A pair of transport rollers 22 for transporting the fed paper P is disposed at the end of the paper transport path 16 on the paper feed cassette 11 side, and the end of the paper transport path 16 on the transport belt 13 side is A registration roller pair 23 for performing secondary paper feeding is disposed. The paper P is transported on the transport belt 13 from the right to the left in the drawing (see arrow A in FIG. 1).

  The ink tank 12 is composed of ink tanks 12K, 12C, 12M, and 12Y arranged side by side in the left-right direction (paper transport direction) in the figure, and black (K), cyan (C), magenta (M), and yellow, respectively. (Y) ink is stored.

  The conveying belt 13 conveys the paper P, which is secondarily fed by the registration roller pair 23, to the left, and to the left and right outer sides (downstream and upstream in the sheet conveying direction A) of the inkjet head 14. A pair of transport rollers 24 and a transport roller 25 are disposed over the pair.

  A recovery port 26 having an opening on the upper surface for recovering excess ink during printing is disposed below the transport roller 24, and a connection pipe 28 is connected to the lower side of the recovery port 26. A waste ink tank 27 is disposed.

  Further, a discharge roller pair 29 is provided on the downstream side (left direction in the figure) of the conveying belt 13, and a discharge port 30 is opened on the left side wall of the apparatus on the downstream side (left side) of the discharge roller pair 29. A discharge tray 31 on which the paper P discharged through the discharge port 30 is placed is provided.

  The inkjet head 14 has a nozzle surface 41 on its lower surface, and is supported at a printing position at a predetermined interval from the paper conveyance surface of the conveyance belt 13. The inkjet head 14 is composed of line heads 14K, 14C, 14M, and 14Y arranged in parallel in the left-right direction. Each of the line heads 14K, 14C, 14M, and 14Y ejects black (K), cyan (C), magenta (M), and yellow (Y) inks with the following structure.

  On the nozzle surface 41 of the inkjet head 14, a large number of nozzles are arranged in the width direction of the sheet for each line head 14 </ b> K, 14 </ b> C, 14 </ b> M, 14 </ b> Y.

  FIG. 2 is a structural diagram of the line head 14K of the inkjet printer 1 in the present embodiment. The line heads 14C, 14M, and 14Y have the same configuration. On the nozzle surface 41 of the line head 14K, N rows (four rows in the figure) nozzles 40 are arranged in the paper transport direction. The line head 14K is divided into M blocks in the paper width direction. That is, in the line head 14K, only one nozzle 40 is provided in the same direction as the paper transport direction.

  FIG. 3 is a cross-sectional view for explaining the configuration in the vicinity of the nozzle 40. As shown in the figure, a pressurizing chamber 45 communicating with a nozzle 40 which is a through hole formed in the nozzle surface 41 is provided. A vibration plate 42 is provided on the upper surface of the wall 45 a above the pressurizing chamber 45. With the diaphragm 42 as a common electrode, individual electrodes 44 are provided on the upper surface of the diaphragm 42. Each pressurizing chamber 45 communicates with an ink liquid chamber (not shown) formed in the line head 14K. The ink liquid chamber of the line head 14K communicates with the ink tank 12K through an ink supply tube (not shown).

  FIG. 4 is a configuration diagram of the control unit 50 of the inkjet printer 1 according to the first embodiment. The control unit 50 of the ink jet printer 1 includes a CPU (Central Processing Unit) 51, a RAM (Random Access Memory) 52, a ROM (Read Only Memory) 53, a HDD (Hard Disk Drive) 54, a transport belt 13, a paper feed roller 21, and the like. A driver 55 corresponding to each of the drive units is provided and connected via an internal bus 56. The CPU 51 is provided with a timer 57, and the time measured by the timer 57 is stored in the HDD 54. The CPU 51 uses, for example, the RAM 52 as a work area, executes a program stored in the ROM 53, the HDD 54, and the like, and controls the operation of each drive unit by exchanging data and commands with the driver 55 based on the execution result. To do. In addition, each operation to be described later other than the drive unit is also controlled by the CPU 51 executing a program.

  An example of the history storage unit of the present invention corresponds to the HDD 54 of the present embodiment.

  Next, a method for driving the ink jet printer according to the first embodiment of the present invention will be described.

  FIG. 5 is a diagram showing an operation flow of the ink jet printer according to the first embodiment.

  In the inkjet printer 1 according to the first embodiment, the use end time when the previous ink ejection operation was performed is stored in the HDD 54 for each nozzle 40.

  First, the inkjet printer 1 according to the first embodiment receives image data transmitted from a personal computer or the like. This corresponds to step 1 in FIG. 5 (hereinafter, step is abbreviated as ST).

  Next, the CPU 51 reads the use end time when the previous ink ejection operation was performed from the HDD 54, compares it with the current time, and calculates the unused time for each nozzle 40 (ST2).

  Then, the CPU 51 calculates whether or not the unused time is longer than a predetermined time in each nozzle 40, and determines whether or not there is a nozzle whose unused time is longer than the predetermined time (ST3). For example, the predetermined time can be set to 30 minutes, 15 minutes, or the like.

  Next, with respect to a block including the nozzles 40 that have not been used for a predetermined time or longer, vibrations by the vibration plate 42 based on the non-ejection drive waveform are generated so that the ink liquid level of all the nozzles 40 of the block oscillates. It is given for a certain time (ST4). Here, the non-ejection drive waveform, which is an example of the first non-ejection drive waveform of the present invention, is a waveform that imparts vibration to the meniscus (ink liquid surface) to the extent that ink is not ejected from the nozzle 40. As an example of this waveform, there is a rectangular wave having a height of 20V and an interval of 1 μsec as shown in FIG. The fixed time can be set to 15 seconds, 30 seconds, or the like, for example. The above ST1 to ST4 correspond to an example of the control process of the present invention.

  Next, the use end time stored in the HDD 54 is updated for the nozzle 40 corresponding to the vibrating diaphragm 42 (ST5). This ST5 corresponds to an example of a history accumulation process of the present invention.

  Thereafter, an ejection drive waveform for ejecting ink from the nozzles 40 is applied to the vibration plate 42 based on the received image data. Then, the electrode 44, the diaphragm 42, and the upper wall 45a of the pressurizing chamber 45 are integrally deformed, and the ink in the pressurizing chamber 45 is pressurized. Ink is ejected from the nozzle 40 onto the paper that has been printed, and printing is performed (ST6). At this time, the number of prints corresponding to the image data received at one time is performed. In other words, when the image data covers a plurality of sheets, the process proceeds to the next ST7 after printing all the plurality of sheets. As an example of the ejection drive waveform for ejecting ink, a rectangular wave having a voltage of 24 V and a width of 7 μs as shown in FIG. 13 can be exemplified.

  Next, for each nozzle 40 from which ink was ejected, the time (use end time) at which the ink ejection operation was performed in ST6 is updated and stored in the HDD 54 (ST7). This ST7 corresponds to an example of a history accumulation process of the present invention. The ink jet printer 1 is in a standby state until the next process is performed (ST8).

  As described above, in the first embodiment, the diaphragm 42 corresponding to the nozzles 40 that are not used for a certain period of time is vibrated, and the diaphragm 42 corresponding to the nozzles 40 that are being used is not vibrated. There is no vibration.

  Therefore, the ink jet printer of the first embodiment can keep the life of the diaphragm longer while preventing nozzle clogging.

  Note that a second non-ejection drive waveform that causes a vibration that is weaker than the above-described non-ejection drive waveform may be applied to the diaphragm 42 corresponding to the nozzle 40 whose unused time is not longer than the predetermined time. As this second non-ejection drive waveform, there is a rectangular wave having a height of 15 V and an interval of 1 μsec as shown in FIG.

  In the first embodiment, the vibration based on the non-ejection drive waveform is performed in units of blocks. However, only the vibration plate 42 corresponding to the nozzle 40 whose unused time is longer than a predetermined time is vibrated. May be.

  In the first embodiment, the use end time is stored in the HDD 54 in units of nozzles, but the use end time may be stored in units of blocks.

  In the first embodiment, the use end time of the nozzle is accumulated in the HDD 54, but the use start time may be accumulated.

  In the first embodiment, the vibration plate 42 corresponding to all the nozzles 40 whose unused time is equal to or longer than the predetermined time is vibrated. However, the nozzles 40 used for printing the transmitted image data. Vibration may be applied only to the diaphragm 42 corresponding to the above.

  Further, for example, a plurality of predetermined times may be provided in stages, such as 1 hour, 30 minutes, and 15 minutes, and control may be performed such that the longer the unused time is, the longer the time for vibrating the diaphragm 42 is.

(Embodiment 2)
The ink jet printer according to the second embodiment of the present invention will be described below. FIG. 8 is a configuration diagram of the inkjet printer 2 according to the second embodiment.

  The basic configuration of the inkjet printer 2 of the second embodiment is the same as that of the first embodiment, except that a CCD sensor 15 is provided downstream of the inkjet head 14 as shown in FIG. . Therefore, this difference will be mainly described.

  FIG. 9 is a flowchart showing the control of the ink jet printer according to the second embodiment.

  When the power of the ink jet printer 1 according to the second embodiment is turned on (ST10), the paper is first transported from the paper feed cassette 11 to the transport belt 13 via the paper transport path 16. Then, a test image is printed on a sheet (ST11).

  This test image is read by the CCD sensor 15 which is an example of the image reading unit of the present invention (ST12). Then, it is compared with the test image data stored in the HDD 54 (ST13).

  FIG. 10A is a diagram illustrating an example of a test image printed on a sheet in a normal state. In FIG. 10A, a droplet 60 ejected from one nozzle 40 onto a sheet is shown as one circle. Since one nozzle 40 is disposed in the same direction as the transport direction as described with reference to FIG. 2, the droplet 60 formed in the transport direction of the paper is ejected from one nozzle 40. The droplets 60 ejected from one nozzle 40 are shown in FIG. 10A as 60a to 60e. These droplets are dropped in the order of the droplets 60a to 60e. Note that the droplet 60a and the droplet 60a ′ arranged in a direction perpendicular to the sheet conveyance direction are ejected from adjacent nozzles.

  FIG. 10B is a diagram illustrating a state in which clogging occurs in the nozzle 40 and white streaks occur because ink does not fly straight. In FIG. 10B, white streaks are generated because the ink in the second row from the right flies to the left.

  FIG. 10C is a diagram illustrating a state in which a test image printed on a sheet is read by the CCD sensor 15. The reading resolution of the CCD sensor 15 of the first embodiment is 2400 dpi, and the resolution of the ink jet printer is 600 dpi. A droplet 60 shown in FIG. 10C corresponds to one dot of 600 dpi.

  Here, the CPU 51 compares the image data shown in FIG. 10A stored in advance in the HDD 54 when normally formed and the image data shown in FIG. 10C read by the CCD sensor 15. . By comparison, the droplet 60 corresponds to one dot of 600 dpi as shown in FIG. 10C, and the CCD sensor 15 can detect the white stripe 61. A test image is formed for each of the line heads 14K, 14C, 14M, and 14Y.

  By this comparison, it is determined whether there is a nozzle 40 that is clogged (ST14). If there is a nozzle 40 in which this clogging has occurred, all the diaphragms 42 of the block including that nozzle 40 are vibrated based on the first drive waveform (ST15).

  Next, the use time for the nozzle 40 corresponding to the vibrating diaphragm 42 is stored in the HDD 54, and the use time is updated (ST16).

  Thereafter, the ink jet printer 2 stands by until image data for printing is received (ST17).

  As described above, in the second embodiment, it is possible to prevent disturbance of an image during printing by specifying a nozzle that is actually clogged and applying vibration.

  In an apparatus that uses a CCD sensor for calibration (density correction), color registration (color misregistration correction), etc., the existing CCD sensor can be used as the CCD sensor 15 of the present embodiment. It is possible to identify a nozzle that is clogged without having to increase the number of points.

  In addition, after applying the vibration by the first non-ejection drive waveform, the test image is printed again, the nozzle clogging is inspected, and if necessary, the vibration by the first non-ejection drive waveform is given. good. A control flow diagram in this case is shown in FIG. In FIG. 11, after ST16, ST11 is performed again, and ST11 to ST16 are repeated until no clogging occurs. In addition, when a predetermined number of loops are made, an error may be displayed to inform the user that repair or cleaning is necessary.

  In the present embodiment, only when the ink jet printer is started up, a test image is printed to determine the occurrence of nozzle clogging. For example, as in the first embodiment, a predetermined time is required before the printing operation. When there is a nozzle that has not been used, a test image may be printed to determine the occurrence of nozzle clogging. In this case, it is possible to detect clogging occurring in the nozzles whose unused time is within a predetermined time.

  Furthermore, when it is determined that nozzle clogging has occurred by printing a test image before the printing operation, vibration may be applied only to the vibration plate 42 corresponding to the nozzle 40 used for printing.

(Embodiment 3)
The ink jet printer according to the third embodiment of the present invention will be described below.

  The configuration of the ink jet printer of the third embodiment is the same as that of the second embodiment described with reference to FIG. 8, but the control flow is different. Therefore, only the control flow will be described.

  FIG. 12 is a flowchart for explaining the control of the ink jet printer according to the third embodiment. FIG. 12 shows ST11 to ST16 (a flow chart returning from ST16 to ST11) in FIG. 10 as a clogging prevention process using a test image. In the inkjet printer 2 according to the third embodiment, the use time when the previous ink ejection operation was performed is stored in the HDD 54 for each nozzle 40.

  Image data is transmitted from the personal computer or the like to the ink jet printer according to the first embodiment (ST20).

  Next, the CPU 51 reads the previous ink ejection time from the HDD 54, compares it with the current time, and calculates the unused time for each nozzle 40 (ST21).

  Then, the CPU 51 calculates whether or not the unused time is equal to or longer than the first predetermined time in each nozzle 40, and determines whether or not there is a nozzle whose unused time is equal to or longer than the second predetermined time ( ST22). The second predetermined time can be set to 1 hour, for example.

  When it is determined in ST22 that the time is equal to or longer than the second predetermined time, the clogging prevention process using the test image is performed again (ST23). Thereafter, printing is performed based on the received image data (ST24).

  Finally, the use time is updated for the nozzles used for printing (ST25), and the ink jet printer enters a standby state (ST26).

  On the other hand, when it is determined in ST22 that there is no nozzle whose unused time is equal to or longer than the second predetermined time, it is determined whether or not the unused time is equal to or longer than the first predetermined time (ST27). Here, the first predetermined time is shorter than the second predetermined time, and can be set to 30 minutes or 15 minutes, for example.

  If the unused time is equal to or longer than the first predetermined time, in ST28, all the diaphragms 42 of the block including the corresponding nozzle 40 are vibrated for a certain time based on the first non-ejection drive waveform ( ST28).

  Then, the use time of the nozzle 40 communicating with the vibrating diaphragm 42 is updated and stored in the HDD 54 (ST29).

  Thereafter, based on the received image data, an ejection drive waveform for ejecting ink from the nozzles 40 is applied to the vibration plate 42, and ink is ejected onto the paper conveyed from the paper feed cassette 11 to perform printing. Performed (ST24).

  Finally, the use time is updated for the nozzles used for printing (ST25), and the ink jet printer enters a standby state (ST26).

  On the other hand, if the unused time is less than the second predetermined time, the control in ST28 and ST29 is not performed, and printing is performed in ST25.

  As described above, in the ink jet printer according to the third embodiment, if the unused time is long, the possibility of clogging is increased. When the clogging prevention process is performed and the unused time is short, the first clogging prevention process is performed.

  On the other hand, since the test image is printed in the clogging prevention process by the test image, if it is performed every time image data is received, paper is used and it takes time.

  However, as in this embodiment, by combining with vibration based on the determination based on the unused time, paper can be saved and the time can be shortened.

  In the control flow of the third embodiment, as described in the second embodiment, a clogging prevention process using a test image may be inserted at startup.

  Further, in the third embodiment, the vibration based on the non-ejection drive waveform is performed in units of blocks. However, the vibration is caused only to the vibration plate 42 corresponding to the nozzle 40 whose unused time is a predetermined time or more. May be.

  In the third embodiment, in ST23 and ST28, vibration is applied to the diaphragms 42 corresponding to all the nozzles 40 whose unused time is a predetermined time or longer, but the transmitted image data is printed. Therefore, vibration may be applied only to the diaphragm 42 corresponding to the nozzle 40 used for the purpose.

  In this embodiment, in ST23 and ST28, the non-ejection drive waveform that vibrates the diaphragm 42 uses the first non-ejection drive waveform, but different drive waveforms may be used. .

  The program of the present invention is a program for causing a computer to execute one or both of the history accumulating step and the control step of the above-described ink jet recording apparatus driving method of the present invention. It is a program that runs.

  The recording medium of the present invention is a recording medium that records a program for causing a computer to execute all or part of the operations of all or part of the above-described driving method of the inkjet recording apparatus of the present invention. A recording medium that is readable by a computer and in which the read program executes the operation in cooperation with the computer.

  The “part of the process” of the present invention means one or several of the plurality of processes.

  Further, the “operation of the process” of the present invention means the operation of all or a part of the process.

  Further, one use form of the program of the present invention may be an aspect in which the program is recorded on a recording medium such as a ROM readable by a computer and operates in cooperation with the computer.

  Also, one use form of the program of the present invention is an aspect in which the program is transmitted through a transmission medium such as the Internet, a transmission medium such as light, radio wave, and sound wave, read by a computer, and operates in cooperation with the computer. Also good.

  The computer of the present invention described above is not limited to pure hardware such as a CPU, but may include firmware, an OS, and peripheral devices.

  As described above, the configuration of the present invention may be realized by software or hardware.

The first invention specifically described in the first to third embodiments is as described above.
An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber;
A history accumulating unit for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A control unit that vibrates,
The first non-ejection drive waveform is an inkjet recording apparatus that is a waveform that imparts vibration to the diaphragm so as not to eject the ink from the nozzles.

Also, the second invention is
The part of the nozzles is the ink jet recording apparatus according to the first aspect of the invention, which is a nozzle to be used in the printing operation.

Also, the third invention is
The control unit is
In the ink jet recording apparatus according to the second aspect of the present invention, the unused time for each nozzle is obtained from a use start or end time in a previous printing operation accumulated as the use history.

Also, the fourth invention is
The use start or end time is an ink jet recording apparatus according to a third aspect of the invention, which is updated when vibration is applied to the diaphragm based on the first non-ejection drive waveform.

Also, the fifth invention is
The control unit has an amplitude smaller than the first non-ejection drive waveform for the diaphragm corresponding to the nozzle whose unused time is less than the first predetermined time before the printing operation. It is the ink jet recording apparatus according to the first aspect of the present invention, which performs control to vibrate based on a second non-ejection driving waveform.

In addition, the sixth invention,
The inkjet head is divided into a plurality of blocks for each of a plurality of nozzles,
The control unit is
Before the printing operation, control is performed to vibrate all the diaphragms of the block having the nozzles whose unused time is equal to or longer than the first predetermined time based on the first non-ejection drive waveform. The inkjet recording apparatus according to the first aspect of the invention is performed.

In addition, the seventh invention,
An image reading unit for reading at least a test image formed by the inkjet head;
If the unused time is equal to or longer than the first predetermined time and less than the second predetermined time before the printing operation, the control unit sets the unused time based on the usage history to the first time. Based on the first non-ejection drive waveform, the diaphragm corresponding to all or a part of the nozzles that are not less than a predetermined time is vibrated,
When the unused time is equal to or longer than the second predetermined time, a test image is formed by the inkjet head, the test image is read by the image reading unit, and clogging is performed based on the result of the reading. The inkjet recording apparatus according to the first aspect of the invention controls the vibration plate corresponding to all or a part of the nozzles determined to have the occurrence of the occurrence of vibration so as not to eject the ink from the nozzles. It is.

In addition, the eighth invention is
The control unit is
A test image is formed by the inkjet head until it is not determined that the clogging has occurred, and the test image is read by the image reading unit. In the ink jet recording apparatus according to the seventh aspect of the present invention, the control is performed such that the corresponding vibration plate is subjected to a vibration that does not eject the ink from the nozzle.

In addition, the ninth invention,
The vibration waveform that gives the vibration corresponding to the nozzle determined to be clogged to the extent that the ink is not discharged from the nozzle is the same waveform as the first non-ejection drive waveform. This is the ink jet recording apparatus of the seventh invention.

Also, the tenth invention is
An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber; Ink jet recording apparatus driving method,
A history accumulating step for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. Equipped with a control process to vibrate,
The first non-ejection drive waveform in the control step is a method for driving an ink jet recording apparatus, wherein the first non-ejection drive waveform is a waveform that imparts vibration to the diaphragm so as not to eject the ink from the nozzles.

The eleventh invention is
In the driving method of the ink jet recording apparatus of the tenth aspect of the present invention,
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A program for causing a computer to execute a control process for causing vibration.

In addition, the twelfth invention
A recording medium on which the program of the eleventh aspect of the present invention is recorded, which is a recording medium that can be processed by a computer.

The thirteenth invention is
An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber;
An image reading unit for reading at least a test image formed by the inkjet head;
A test image is formed by the inkjet head, the test image is read by the image reading unit, and a diaphragm corresponding to a nozzle that is determined to be clogged based on the result of the reading is a first plate. A control unit that vibrates based on the non-ejection drive waveform,
The first non-ejection drive waveform is an inkjet recording apparatus that is a waveform that causes the diaphragm to vibrate with a magnitude that does not cause the ink to be ejected from the nozzles.

In addition, the fourteenth invention
The control unit vibrates the vibration plate of the nozzle that is determined not to be clogged during the start-up operation based on the second non-ejection drive waveform,
The second non-ejection drive waveform is an ink jet recording apparatus according to a thirteenth aspect of the invention, which is a waveform that causes the diaphragm to vibrate with an amplitude smaller than that of the first non-ejection drive waveform.

The fifteenth invention
The inkjet head is divided into a plurality of blocks in which a plurality of nozzles are arranged,
The control unit is
According to a thirteenth aspect of the present invention, during the start-up operation, all the diaphragms of the block having the nozzles that are determined to be clogged are vibrated based on the first non-ejection drive waveform. Inkjet recording apparatus.

Also, the sixteenth invention is
The control unit determines the occurrence of clogging before a printing operation,
The partial nozzle is an ink jet recording apparatus according to a thirteenth aspect, which is a nozzle that is to be used in the printing operation.

  INDUSTRIAL APPLICABILITY According to the ink jet recording apparatus and the ink jet recording apparatus driving method of the present invention, it is possible to keep the life of the diaphragm longer while suppressing the occurrence of nozzle clogging, which is useful as an ink jet printer or the like. It is.

1 is a front configuration diagram of an ink jet printer according to a first embodiment of the present invention. The reverse view for demonstrating the inkjet head of the inkjet printer in Embodiment 1 concerning this invention. Sectional drawing for demonstrating the nozzle vicinity of the inkjet printer in Embodiment 1 concerning this invention. 1 is a configuration diagram for explaining a control system of an ink jet printer according to a first embodiment of the present invention. FIG. 1 is a control flowchart of the ink jet printer according to the first embodiment of the present invention. The figure which shows an example of the drive waveform for non-ejection in Embodiment 1 concerning this invention. The figure which shows an example of the drive waveform for non-ejection in the modification of Embodiment 1 concerning this invention. Front view of ink jet printer according to Embodiment 2 of the present invention Control flow diagram of ink jet printer according to second embodiment of the present invention (A) The figure for demonstrating the test image printed on the paper in the inkjet printer in Embodiment 2 concerning this invention, (b) The test printed on the paper in the inkjet printer in Embodiment 2 concerning this invention (C) A diagram for explaining an image. A diagram for explaining a state in which a test image is read by a CCD sensor in the ink jet printer according to the second embodiment of the invention. Control flow chart of inkjet printer in modification of embodiment 2 according to the present invention Control flow chart of inkjet printer in embodiment 3 according to the present invention The figure which shows an example of the drive waveform for non-ejection in Embodiment 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Inkjet printer 11 Paper feed cassette 12 Ink tank 13 Conveyance belt 14 Inkjet head 15 CCD sensor 16 Paper conveyance path 21 Paper feed roller 22 Conveyance roller pair 23 Registration roller pair 24 Conveyance roller 25 Conveyance roller

Claims (12)

An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber;
A history accumulating unit for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A control unit that vibrates,
The first non-ejection drive waveform is a waveform that gives a vibration to the diaphragm so as not to eject the ink from the nozzle.   The inkjet recording apparatus according to claim 1, wherein the some nozzles are nozzles scheduled to be used in the printing operation. The control unit is
The inkjet recording apparatus according to claim 1, wherein the unused time for each nozzle is obtained from a use start or end time in a previous printing operation accumulated as the use history.   The inkjet recording apparatus according to claim 3, wherein the use start or end time is updated when vibration is applied to the diaphragm based on the first non-ejection drive waveform. The control unit is
Before the printing operation, a second non-ejection having an amplitude smaller than the first non-ejection driving waveform is applied to the diaphragm corresponding to the nozzle whose unused time is less than the first predetermined time. The ink jet recording apparatus according to claim 1, wherein control is performed to vibrate based on a driving waveform. The inkjet head is divided into a plurality of blocks for each of a plurality of nozzles,
The control unit is
Before the printing operation, control is performed to vibrate all the diaphragms of the block having the nozzles whose unused time is equal to or longer than the first predetermined time based on the first non-ejection drive waveform. The inkjet recording apparatus according to claim 1, which is performed. An image reading unit for reading at least a test image formed by the inkjet head;
The control unit is
If the unused time is equal to or longer than the first predetermined time and less than the second predetermined time before the printing operation, the unused time is equal to or longer than the first predetermined time based on the usage history. Causing the diaphragm corresponding to all or some of the nozzles to vibrate based on the first non-ejection drive waveform;
When the unused time is equal to or longer than the second predetermined time, a test image is formed by the inkjet head, the test image is read by the image reading unit, and clogging is performed based on the result of the reading. 2. The inkjet recording apparatus according to claim 1, wherein control is performed to apply vibration to the vibration plate corresponding to all or a part of the nozzles determined to have generated no ink from the nozzles. . The control unit is
A test image is formed by the inkjet head until it is not determined that the clogging has occurred, and the test image is read by the image reading unit. The ink jet recording apparatus according to claim 7, wherein the control for applying vibration to the corresponding vibration plate so as not to eject the ink from the nozzles is repeated.   The vibration waveform that gives the vibration corresponding to the nozzle determined to be clogged to the extent that the ink is not discharged from the nozzle is the same waveform as the first non-ejection drive waveform. The inkjet recording apparatus according to claim 7, wherein An inkjet head having a plurality of nozzles for discharging ink, a pressure chamber provided in each of the nozzles, and a vibration plate for applying vibration to the ink filled in the pressure chamber; Ink jet recording apparatus driving method,
A history accumulating step for accumulating usage histories of the plurality of nozzles based on image data;
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. Equipped with a control process to vibrate,
The method of driving an ink jet recording apparatus, wherein the first non-ejection drive waveform in the control step is a waveform that imparts vibration to the diaphragm so as not to eject the ink from the nozzles. The method of driving an ink jet recording apparatus according to claim 10.
Before the printing operation, based on the first non-ejection drive waveform on the diaphragm corresponding to all or some of the nozzles whose unused time is equal to or longer than the first predetermined time based on the usage history. A program for causing a computer to execute a control process for causing vibration.   A recording medium on which the program according to claim 11 is recorded, wherein the recording medium can be processed by a computer.

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