JP2003291371A - Liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet apparatus which can carry out a cleaning operation having superior effects for recovering the liquid drop discharge capability without affecting the discharge of bubbles in a channel. <P>SOLUTION: The liquid jet apparatus has a head member which includes a plurality of nozzle openings, a plurality of pressure generation chambers which communicate with nozzle openings respectively and can store the liquid, a plurality of liquid supply paths for supplying the liquid to each pressure generation chamber, and a plurality of pressure generation means for discharging liquid drops from nozzle openings by changing a pressure of the liquid in pressure generation chambers respectively. A cleaning means carries out the cleaning operation by sucking the liquid from the plurality of nozzle openings in common. While the cleaning means drives, a cleaning auxiliary means drives pressure generation means corresponding to nozzle openings grouped at least in one group on the basis of a cleaning control condition set for each group of grouped nozzle openings. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid ejecting apparatus having a head member for ejecting a liquid from a nozzle opening, for example, an ink jet recording apparatus having a recording head for ejecting ink droplets from the nozzle opening for recording. In particular, the present invention relates to a liquid ejecting apparatus that prevents an increase in viscosity of a liquid at a nozzle opening.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 8, an ink jet recording head (an example of a head member) has a plurality of nozzle openings 40 (only one is shown in the figure) and a pressure generation communicating with each nozzle opening 40. Piezoelectric vibrator 4 abutting on chamber 41 and elastic wall 43 forming a part of this pressure generating chamber
2 and. Then, the pressure inside the pressure generating chamber 41 is changed by contracting and expanding the piezoelectric vibrator 42 according to the print signal, and the ink 44 inside the pressure generating chamber 41 is ejected from the nozzle opening 40 by the pressure change. It is configured to discharge as 45.

In a recent color printing apparatus, not only black ink but also a plurality of types of color inks such as yellow (magenta), magenta (magenta), cyan (blue-green) are used as the ink 44. Nozzle openings 40 are provided for each color.

In the recording head as described above, when the recording data is lost and the recording head itself is in a rest state, the ink 44 near the nozzle openings 40 is dried and clogging occurs. Therefore, the recording head is sealed with the cap while the printing operation is not performed. However, if the recording head is left for a long time while being sealed, the solvent of the ink 44 in the vicinity of the nozzle opening 40 is slightly volatilized. As a result, the viscosity rises, and problems such as immediate improper printing and reduced print quality are likely to occur.

Further, the nozzle opening 40, which continuously ejects the ink droplets 45 by the printing operation, uses the new ink 4
4 is sequentially supplied to cause almost no clogging, but at the nozzle opening 40 located at the upper end, the lower end, etc., where the chance of ejecting the ink droplet 45 is extremely low, the ink 44 near the nozzle opening 40 dries during printing. Thickens and tends to cause clogging.

In order to deal with such a problem, as one of the preliminary operations before the start of printing, at the time when the power of the recording apparatus is turned on or when the first print signal is input, regardless of printing. Ink droplets 45 are forced from each nozzle opening 40.
The “flushing operation” and the “cleaning operation” that eliminate the clogging of the nozzle openings 40 and recover the ink droplet ejection capability are performed by ejecting the ink.

The "flushing operation" is to eject the thickened ink 44 around the nozzle opening 40 in advance by applying a drive signal unrelated to print data to the piezoelectric vibrator 42. Further, the "cleaning operation" is performed when the clogging of the nozzle openings 40 is not completely recovered only by the "flushing operation", and a negative pressure is applied to each nozzle opening 40 by a suction pump to generate a pressure. Ink 4 with increased viscosity, such as in chamber 41
4 is forcibly sucked in advance.

[0008]

DISCLOSURE OF THE INVENTION The inventor has found that a cleaning operation of giving negative pressure to a nozzle opening and discharging ink while giving pressure fluctuation to ink in a pressure generating chamber is
We have found that it can be extremely effective in clearing the clogging of the nozzle openings and recovering the ink droplet ejection capability.

However, in the cleaning operation, since the pressure in the ink in the pressure generating chamber is changed at the same time as the negative pressure is applied to the nozzle opening, the pressure is changed while the ink is flowing. Therefore, the flow of ink and the propagation of pressure waves may interfere with each other, adversely affecting the effect of discharging bubbles in the ink flow path. On the other hand, in the case of an apparatus that performs color printing using multiple types of inks such as black, yellow, cyan, and magenta, there is a difference in the rate at which the solvent evaporates depending on the type of ink,
There is variation in the degree to which the ink thickens. That is,
Even when used under the same conditions, there is a difference in ink ejection capacity depending on the nozzle opening.

Further, the degree of thickening of the ink is increased as the head member is left outside the cap (capping means) or the head member is closed by the cap (capping means). ,
Increase.

The inventor of the present invention has made various studies based on the above findings, and the ink in the pressure generating chamber is applied to the ink only when the effectiveness is recognized during the cleaning operation (during the action of the negative pressure on the nozzle opening). It has been found that it is preferable to generate the pressure fluctuation in terms of recovery of the ink droplet ejection capability and maintenance of the bubble discharge effect in the ink flow path.

The present invention has been made in view of the above circumstances, and provides a liquid ejecting apparatus which is excellent in the recovery effect of the liquid droplet ejecting ability and can carry out a cleaning operation which does not adversely affect the bubble discharging effect in the liquid flow path. The purpose is to provide.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a plurality of nozzle openings, a plurality of pressure generating chambers that communicate with each nozzle opening and can contain a liquid, and a plurality of pressure supplying chambers that supply a liquid. A head member having a liquid supply path and a plurality of pressure generating means for ejecting liquid droplets from each nozzle opening by changing the pressure of the liquid in each pressure generating chamber, and the liquid is commonly supplied from the plurality of nozzle openings. Aspirate
A cleaning unit that performs a cleaning operation, a cleaning control unit that drives the cleaning unit, and a cleaning set for each group of nozzle openings that are grouped while the cleaning control unit is driving the cleaning unit. A liquid ejecting apparatus comprising: a cleaning assisting unit that drives a pressure generating unit corresponding to a nozzle opening grouped into at least one group based on a control condition.

According to the present invention, since the pressure generating means corresponding to the nozzle openings grouped into at least one group is driven during the driving of the cleaning means, the nozzle openings grouped into the group are driven. The recovery of the liquid droplet ejection capability can be sufficiently achieved.

Preferably, the cleaning assisting means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group while the cleaning control means drives the cleaning means. In addition, the pressure generating means corresponding to the nozzle openings divided into other groups are not driven.

In this case, since the pressure generating means corresponding to the nozzle openings grouped into the other group is not driven during the driving of the cleaning means, the nozzle openings grouped into the other group are not flown. The bubble discharging effect inside can be sufficiently maintained. Further, since the driving of the pressure generating means when it is not effective is avoided, the driving cost of the pressure generating means can be reduced and the life of the pressure generating means can be extended.

Preferably, the nozzle openings divided into groups are nozzle openings that use the same type of liquid. For example, the nozzle openings classified into each group are nozzle openings that use the same color ink. The rate at which the solvent of the liquid volatilizes differs depending on the type of liquid, but by grouping each nozzle opening using the same type of liquid,
It is possible to control the cleaning operation for each type of liquid.

Usually, the nozzle openings using the same liquid (for example, ink of the same color) are arranged in rows.
In that case, the cleaning operation control for each type of liquid is the cleaning operation control for each nozzle row.

Further, for example, when a dot dropout inspection is performed on the liquid ejecting apparatus and dot dropout is found in a nozzle opening for ejecting a certain liquid type (for example, ink of a certain color), the liquid type is checked. When the user of the liquid ejecting apparatus can specify (designate) the nozzle openings to be used, it is preferable to drive the corresponding pressure generating means only for such nozzle openings during the driving of the cleaning means. That is, preferably, the nozzle openings classified into the at least one group are nozzle openings specified by the user of the liquid ejecting apparatus.

Alternatively, it is preferable to drive the corresponding pressure generating means during the driving of the cleaning means only for the nozzle opening that uses a liquid type having a high viscosity. That is, preferably, the nozzle openings grouped into the at least one group are nozzle openings using a highly viscous liquid.

Further, preferably, a leaving time measuring means for measuring the leaving time of the head member is provided, and the cleaning assisting means measures the leaving time measured by the leaving time measuring means for a predetermined time. Only when it exceeds the limit, the pressure generating means corresponding to the nozzle openings grouped into the at least one group is driven.

Alternatively, preferably, there are provided capping means for sealing the nozzle opening of the head member, and capping time measuring means for measuring the capping time during which the head member is sealed by the capping means. The cleaning assisting means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group, only when the capping time measured by the capping time measuring means exceeds a predetermined time. It has become.

Further, preferably, the driving frequency of the pressure generating means by the cleaning assisting means is variable depending on the viscosity of the liquid used in the nozzle openings grouped into the at least one group.

Further, preferably, the cleaning auxiliary means is based on a cleaning control condition set for each group of nozzle openings divided into groups while the cleaning control means is driving the cleaning means. , Driving pressure generating means corresponding to the nozzle openings grouped into at least two groups, and the nozzle openings grouped into each of the at least two groups are substantially the same for each group. A liquid having a viscosity is used, and the driving frequency of the pressure generating means corresponding to each group of the at least two groups by the cleaning auxiliary means is the liquid used at the nozzle openings grouped into each group. It is determined depending on the viscosity of each.

In this case, the nozzle openings of each of the at least two groups using the liquids having substantially the same viscosity are dealt with during the driving of the cleaning means in accordance with the driving frequency determined depending on the viscosity. Since the pressure generating means for driving is driven, stepwise cleaning operation control can be performed according to the viscosity state of the liquid.

Further, according to the present invention, the nozzle opening, the pressure generating chamber communicating with the nozzle opening and capable of containing the liquid, the liquid supply path for supplying the liquid to the pressure generating chamber, and the pressure of the liquid in the pressure generating chamber are set. A head member having a pressure generating means for changing and ejecting a liquid droplet from the nozzle opening; a cleaning means for sucking the liquid from the nozzle opening to perform a cleaning operation; and a cleaning control means for driving the cleaning means. In the case where the head member is left unattended for a standing time measuring means and the standing time measured by the standing time measuring means exceeds a predetermined time, the cleaning control means operates the cleaning means. And a cleaning assisting means for driving the pressure generating means during driving. It is a device.

According to the present invention, since the pressure generating means is driven only when the leaving time exceeds the predetermined time during the driving of the cleaning means, it is possible to sufficiently perform the recovery of the liquid droplet discharging ability when the liquid droplet discharging capability is required. Can be achieved.

Further, according to the present invention, the nozzle opening, the pressure generating chamber communicating with the nozzle opening and capable of containing the liquid, the liquid supply path for supplying the liquid to the pressure generating chamber, and the pressure of the liquid in the pressure generating chamber are set. A head member having a pressure generating means for changing and ejecting a liquid droplet from the nozzle opening; a cleaning means for sucking the liquid from the nozzle opening to perform a cleaning operation; and a cleaning control means for driving the cleaning means. Capping means for sealing the nozzle opening of the head member, capping time measuring means for measuring the capping time of the head member sealed by the capping means, and capping measured by the capping time measuring means If the time exceeds the predetermined time, the cleaning control There is a liquid-jet apparatus characterized by comprising: a cleaning auxiliary means for driving the pressure generating means while driving the cleaning means.

According to the present invention, the pressure generating means is driven only when the cleaning means is driven and the capping time exceeds a predetermined time. Therefore, it is sufficient when recovery of the liquid droplet ejection capability is required. Can be aimed at.

Further, according to the present invention, a plurality of nozzle openings, a plurality of pressure generating chambers communicating with each nozzle opening and capable of accommodating a liquid, and a plurality of liquid supply paths for supplying a liquid to each pressure generating chamber. A head member having a plurality of pressure generating means for changing the pressure of the liquid in each pressure generating chamber to eject a liquid droplet from each nozzle opening, and sucking the liquid in common from the plurality of nozzle openings, A control device for controlling a liquid ejecting apparatus comprising a cleaning means for performing a cleaning operation, wherein the cleaning control means drives the cleaning means, and while the cleaning control means drives the cleaning means, Nozzle grouped into at least one group based on cleaning control conditions set for each group of nozzle openings A cleaning auxiliary means for driving the pressure generating means corresponding to the mouth, which is a control apparatus characterized by comprising a.

Alternatively, according to the present invention, the nozzle opening, the pressure generating chamber communicating with the nozzle opening and capable of containing the liquid, the liquid supply path for supplying the liquid to the pressure generating chamber, and the pressure of the liquid in the pressure generating chamber are set. A head member including: a pressure generating unit that changes and discharges a liquid droplet from a nozzle opening;
A control device for controlling a liquid ejecting apparatus comprising: a cleaning unit that sucks liquid from the nozzle opening to perform a cleaning operation; and a leaving time measuring unit that measures a leaving time of the head member. In the case where the cleaning control means for driving the cleaning means and the leaving time measured by the leaving time measuring means exceed a predetermined time, pressure is applied while the cleaning control means is driving the cleaning means. And a cleaning assisting means for driving the generating means.

Alternatively, according to the present invention, the nozzle opening, the pressure generating chamber communicating with the nozzle opening and capable of containing the liquid, the liquid supply path for supplying the liquid to the pressure generating chamber, and the pressure of the liquid in the pressure generating chamber A head member including: a pressure generating unit that changes and discharges a liquid droplet from a nozzle opening;
Cleaning means for sucking liquid from the nozzle opening to perform a cleaning operation; capping means for sealing the nozzle opening of the head member; and the head member,
A controller for controlling a liquid ejecting apparatus, comprising: a capping time measuring unit for measuring a capping time sealed by the capping unit, a cleaning control unit for driving the cleaning unit, and the capping time measuring unit. Cleaning assisting means for driving the pressure generating means while the cleaning control means drives the cleaning means when the capping time measured by the means exceeds a predetermined time. It is a control device that operates.

The cleaning control means and the cleaning auxiliary means can be realized by a computer system.

Further, a program for realizing each means in a computer system and a computer-readable recording medium having the program recorded therein are also covered by the present invention.

Specifically, a program executed by a computer system including at least one computer to cause the computer system to realize the control device is a subject of protection in the present case. A computer-readable recording medium recording the program is also a subject of protection in this case.

Further, an instruction for controlling a second program operating on a computer system including at least one computer is included, and the instruction is executed by the computer system to control the second program. A program that causes the computer system to realize the control device is also a protection target of the present case. A computer-readable recording medium recording the program is also a subject of protection in this case.

Here, the recording medium includes not only a floppy (registered trademark) disk that can be recognized as a single body but also a network for propagating various signals.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

FIG. 1 is a diagram showing an example of a peripheral structure of an ink jet recording apparatus to which the present invention is applied. This device has six ink cartridges 7 mounted on the top,
A carriage 1 having a recording head 6 attached to its lower surface,
A capping device 8 for sealing the recording head 6 is provided. The inside of the ink cartridge 7 is divided into six ink chambers, and in each ink chamber, cyan (C), light cyan (LC), magenta (M), light magenta (LM), yellow (Y), black ( B
Six types of ink of K) are stored.

The carriage 1 is provided with a timing belt 2
It is connected to a pulse motor 3 (stepping motor) via a guide bar 4, and is guided by a guide bar 4 to reciprocate in the paper width direction of the recording paper 5. The surface of the carriage 1 that faces the recording paper 5 (the lower surface in this example)
The recording head 6 is attached to. Then, ink is supplied from the ink cartridges 7 to the recording head 6, and ink droplets are ejected onto the upper surface of the recording paper 5 while moving the carriage 1 to print an image or characters on the recording paper 5 by a dot matrix. ing.

The capping device 8 comprises the carriage 1
It is provided in a non-printing area within the moving range of No. 2 and is designed to prevent the nozzle opening from drying as much as possible by sealing the nozzle opening of the recording head 6 during printing suspension. The capping device 8 also acts as a container for receiving ink droplets ejected from the recording head 6 by the flushing operation. Further, the capping device 8 is connected to a suction pump 9 and applies a negative pressure to the nozzle opening of the recording head 6 to suck ink from the nozzle opening during the cleaning operation.

FIG. 2 is a diagram showing an example of the recording head 6. The recording head 6 includes a base 11 and the base 1.
Piezoelectric vibrator 13 vibratably accommodated in the first accommodation chamber 12
And the flow path unit 14 fixed to the lower surface of the base 11.
It has and.

The flow path unit 14 has a nozzle plate 16 having a plurality of nozzle openings 15 formed in a row, a thin vibrating plate 21 that elastically deforms, and the nozzle plate 16 described above.
And the flow path forming plate 20 sandwiched between the vibration plates 21 and fixed in a liquid-tight manner. The flow path forming plate 20 has a plurality of pressure generating chambers 17 communicating with each of the nozzle openings 15, an ink chamber 18 supplied with ink from the ink cartridge 7, and a plurality of pressure generating chambers 17 from the ink chamber 18. A space corresponding to the ink supply path 19 for supplying the ink is formed. Then, separate ink chambers 18 and rows of nozzle openings 15 are provided for each of the six types of ink colors.

The piezoelectric vibrator 13 is attached to a support substrate 22, and the support substrate 22 is used for the accommodation chamber 12 of the base 11.
By being fixed inside, it is vibratably accommodated in the accommodation chamber 12. The lower end of the piezoelectric vibrator 13 is connected to the island portion 2 of the diaphragm 21 of the flow path unit 14.
It is bonded to 1a. In the figure, 23 is a signal cable for sending a drive signal to the piezoelectric vibrator 13.

The recording head 6 performs printing, for example, as follows. That is, first, when the piezoelectric vibrator 13 is charged and contracts, the pressure generating chamber 17 expands and the internal pressure decreases. As a result, the nozzle opening 1
The meniscus 5 is slightly drawn into the pressure generating chamber 17, and the ink in the ink chamber 18 is supplied to the pressure generating chamber 17 through the ink supply passage 19.

Then, after a lapse of a predetermined time, the piezoelectric vibrator 1
When the electric charge of 3 is discharged and the piezoelectric vibrator 13 returns to the original state, the pressure generating chamber 17 contracts and the internal pressure increases. As a result, the ink in the pressure generating chamber 17 is compressed and ejected as an ink droplet from the nozzle opening 15, and the ink droplet is ejected onto the upper surface of the recording paper 5 to print an image or a character.

FIG. 3 is a schematic view showing the first embodiment of the ink jet recording apparatus of the present invention. In FIG. 3, reference numeral 30 denotes a printer controller that receives various data from a host (not shown). Although details will be described later with reference to FIG. 7, a drive voltage is applied to the piezoelectric vibrator 13 in response to a print signal. A printing operation of applying and ejecting ink droplets from the recording head 6 is executed. In addition, in response to the flushing command, a drive voltage that is not related to the print signal is applied to the piezoelectric vibrator 13, and a flushing operation of ejecting ink droplets from each nozzle opening 15 of the recording head 6 is executed. further,
During a cleaning operation in a cleaning assist mode, which will be described later, a drive voltage irrelevant to the print signal is applied to the piezoelectric vibrator 13 to change the ink pressure in a desired nozzle opening 15 of the recording head 6.

Reference numeral 32 denotes a pump drive means, which applies a negative pressure to the recording head 6 sealed by the capping device 8 (capping means) by the suction pump 9 to forcibly suck ink from all the nozzle openings 15. Perform the cleaning operation.

A cleaning control means 31 receives a signal from the host and controls the cleaning operation by the pump drive means 32.

Reference numeral 34 denotes a capping timer (capping time measuring means), which is activated upon detecting that the recording head 6 is sealed by the capping device 8, and in a state where the recording head 6 is sealed by the capping means 8. Measure the left-over capping time. Further, 35 is a leaving timer (leaving time measuring means), which measures the time when the recording head 6 is left in a state of being released from the capping device 8. The capping timer 34 and the leaving timer 3
All of 5 are reset when a signal is output.

Reference numeral 33 denotes a mode selecting means, which receives a signal of the capping time output from the capping timer 34 or the leaving time output from the leaving timer 35 and does not operate the piezoelectric vibrator 13 for each color ink. Either the normal mode or the cleaning assist mode for operating the piezoelectric vibrator 13 is selected, and the signal of the selected mode is output to the printer controller 30 and the cleaning control means 31.

FIG. 4 is an explanatory diagram showing an example of the mode selection conditions depending on the capping time in the above ink jet recording apparatus. In this example, FIG.
As shown in (c), the capping time is divided into three areas of less than 1 month, 1 to 2 months, and 2 months or more.

In general, as the capping time becomes longer, the viscosity of the ink increases, and the ink ejection capability of the nozzle openings decreases. When the above six types of inks are pigment inks, the viscosity increasing speed is high in the order of M, BK, and other colors, and the ink discharge ability of the nozzle openings is likely to be decreased quickly. Therefore, for ink with a high viscosity increasing speed, when the capping time exceeds the predetermined time, the cleaning assist mode for operating the piezoelectric vibrator 13 is selected. Set shorter.

In the present embodiment, as shown in FIG. 4A, the nozzle opening 15 using magenta (M) ink is used.
For the (nozzle row), the cleaning normal mode is selected when the capping time is less than one month, and the cleaning assist mode is selected when the capping time is one month or more.

Further, as shown in FIG. 4B, for the nozzle openings 15 (nozzle row) in which black (BK) ink is used, the cleaning normal mode is selected if the capping time is less than 2 months. When the capping time is 2 months or more, the cleaning assist mode is selected.

On the other hand, as shown in FIG. 4C, nozzle openings 15 (nozzle row) in which cyan (C) ink, light magenta (LM) ink, light cyan (LC) ink and yellow (Y) ink are used. For, the cleaning normal mode is selected regardless of the capping time.

The relationship between the standing time and the mode selection condition is almost the same as the relationship between the capping time and the mode selection condition shown in FIG. 4, but the division standard values for the capping time are 1 month and 2 months. , The standing time can be read as 1 week and 2 weeks.

The values of 1 month and 2 months, which are the standard values for the capping time, and 1 week and 2 weeks, which are the standard values for the leaving time, are all set to the temperature standard value of 40 ° C. It is an experimentally derived value by the present inventor based on this. Preferably, each of these values can be modified according to the temperature or humidity of the environment in which the inkjet recording apparatus is actually installed.

Here, an example of the operation of the ink jet recording apparatus will be described with reference to the flow chart shown in FIG. In addition, in FIG. 5, "S" means a step.

First, when the host issues a cleaning operation command, the capping time by the capping timer 34 is detected (S1). Alternatively, the leaving time is detected by the leaving timer 35 (S1). Next, the mode selecting means 33 selects the cleaning normal mode or the cleaning auxiliary mode for each ink color based on the obtained capping time or the standing time (S).
2).

When the cleaning normal mode is selected, the cleaning operation is executed by the pump driving means 32 and the suction pump 9 (S3).

When the cleaning assist mode is selected, the pump driving means 32 and the suction pump 9 also carry out the cleaning operation. During the operation of the suction pump 9, the nozzle opening 1 in which the ink color concerned is used.
The piezoelectric vibrator 13 corresponding to No. 5 is driven (S4).

For example, the driving frequency of the piezoelectric vibrator 13 during the operation of the suction pump 9 may be the basic frequency of the driving signal for printing 8.64 kHz × 3 = 25.9.
It is 2 kHz.

As described above, according to the above-mentioned ink jet recording apparatus, the suction pump 9 is in operation at the nozzle opening 15 through which the magenta ink (M) or the black ink (BK) having a relatively high viscosity increasing speed is ejected ( Since the piezoelectric vibrator 13 is driven during the cleaning operation), it is possible to sufficiently recover the ink droplet ejection capability at the nozzle opening 15.

On the other hand, cyan (C), light magenta (LM), and light cyan (L), which have relatively slow viscosity increasing rates.
C) In the nozzle opening 15 from which the yellow (Y) ink is ejected, since the piezoelectric vibrator 13 is not driven during the operation of the suction pump 9 (during the cleaning operation), the inside of the ink flow path communicating with the nozzle opening 15 It does not adversely affect the bubble elimination effect of. Further, since it is possible to avoid driving the piezoelectric vibrator 13 which is not particularly necessary, the driving cost of the piezoelectric vibrator 13 is reduced and the life thereof is not unnecessarily shortened.

The driving frequency of the piezoelectric vibrator 13 during the operation of the suction pump 9 can be changed appropriately. In the above-described embodiment, the drive frequency for driving the piezoelectric vibrator 13 in the cleaning assist mode is common, but it is preferable to set each drive frequency according to the viscosity state of each ink (liquid).

For example, the higher the viscosity of the ink, the higher the driving frequency is preferably used. In this case, it is possible to realize the stepwise driving of the piezoelectric vibrator 13 during the cleaning operation with the driving frequency set stepwise according to the viscosity of the ink.

The drive frequency can be changed by increasing or decreasing the frequency itself of the basic waveform. Alternatively, the drive frequency can be changed by increasing or decreasing the number of pulse waveforms selected (picked up) from the basic waveform.

In some cases, for example, as shown in FIG. 6, when the capping time is 1 to 2 months (or the leaving time is 1 to 2 weeks) for the nozzle opening 15 in which magenta ink is used. The corresponding piezoelectric vibrator 13 is driven at a drive frequency of 25.92 kHz, while 25.92 kHz when the capping time is 2 months or longer (left-standing time is 2 weeks or longer).
It is preferable that the corresponding piezoelectric vibrator 13 be driven at a driving frequency F higher than. That is, it is preferable that a plurality of drive frequencies be set stepwise with respect to the capping time (or the standing time).

Here, an example of the printer controller 30 in the above embodiment will be described in detail with reference to FIG.

The printer controller 30 includes an external interface (external I / F) 132, a RAM 133 that temporarily stores various data, a ROM 134 that stores control programs and the like, a control unit 111 that includes a CPU and the like. And an oscillator circuit 135 for generating a clock signal
A drive signal generating circuit 136 for generating a drive signal COM to be supplied to the recording head 6, and a drive signal, dot pattern data (bitmap data) developed based on print data, and the like to the print engine 131. And an internal interface (internal I / F) 137 that operates.

The external I / F 132 receives print data composed of, for example, a character code, a graphic function, image data, etc. from a host computer (not shown) or the like. Further, a busy signal (BUSY) and an acknowledge signal (ACK) are output to the host computer or the like through the external I / F 132.

The RAM 133 has a reception buffer, an intermediate buffer, an output buffer and a work memory (not shown). Then, the reception buffer is the external I / F 13
The print data received via 2 is temporarily stored, the intermediate buffer stores the intermediate code data converted by the control unit 111, and the output buffer stores the dot pattern data. Here, the dot pattern data is
It is print data obtained by decoding (translating) intermediate code data (for example, gradation data).

The ROM 134 stores font data, graphic functions, etc. in addition to a control program (control routine) for performing various data processing.
Further, the ROM 134 also stores setting data for maintenance operation as a maintenance information holding unit.

The control unit 111 performs various controls according to the control program stored in the ROM 134. For example,
The print data in the reception buffer is read, the print data is converted into intermediate code data, and the intermediate code data is stored in the intermediate buffer. In addition, the control unit 1
Reference numeral 11 analyzes the intermediate code data read from the intermediate buffer, and with reference to the font data, the graphic function, etc. stored in the ROM 134, develops (decodes) the dot pattern data. Then, the control unit 111
Stores the dot pattern data in the output buffer after performing the necessary decoration processing.

If dot pattern data for one line that can be printed is obtained by one main scan of the print head 6,
The dot pattern data for one line is sequentially output from the output buffer to the electric drive system 139 of the recording head 6 through the internal I / F 137, and the carriage 1 is scanned to print one line. When one line of dot pattern data is output from the output buffer, the expanded intermediate code data is erased from the intermediate buffer, and expansion processing is performed on the next intermediate code data.

Further, the control section 111 controls the maintenance operation (recovery operation) performed prior to the recording operation by the recording head 6.

The print engine 131 includes a paper feed motor 113 as a paper feed mechanism, a pulse motor 3 as a head scanning mechanism, and an electric drive system 139 for the recording head 6.
And are included.

Further, the electric drive system 139 of the recording head 6 will be described. As shown in FIG. 7, the electric drive system 139 includes a shift register circuit 14 electrically connected in order.
0, a latch circuit 141, a level shifter circuit 142, a switch circuit 143, and the piezoelectric vibrator 13. The shift register circuit 140, the latch circuit 141, the level shifter circuit 142, the switch circuit 143, and the piezoelectric vibrator 13 are respectively provided in the nozzle openings 1 of the recording head 6.
It is provided every five.

In this electric drive system 139, when the bit data applied to the switch circuit 143 is “1”, the switch circuit 143 is in the connected state and the drive signal (COM) is directly applied to the piezoelectric vibrator 13 to cause each piezoelectric element. The vibrator 13 is deformed according to the signal waveform of the drive signal. On the other hand, when the bit data applied to the switch circuit 143 is “0”, the switch circuit 143 is disconnected and the supply of the drive signal to the piezoelectric vibrator 14 is cut off.

As described above, the drive signal can be selectively supplied to each piezoelectric vibrator 13 based on the bit data. Therefore, it is possible to eject ink droplets from the nozzle openings 15 or to slightly vibrate the meniscus, depending on the bit data given.

During the cleaning operation, the piezoelectric vibrator 1 corresponding to the nozzle opening 15 for ejecting a predetermined ink color.
The control mode of the above embodiment in which only 3 is driven is
By controlling the bit data, the recording head control can be performed in substantially the same manner as during printing.

In the above embodiment, the nozzle openings are grouped based on the color (type) of the ink used when determining whether or not to drive the piezoelectric vibrator 13 during the cleaning operation. . This is one preferable mode because the same thickened state is estimated for the nozzle openings using the same color ink.

However, the thickening of the ink at the nozzle openings can be affected by the type of the ink and, for example, the structural factor of the nozzle, particularly the manufacturing error of the nozzle diameter. Generally, the nozzle openings are formed for each nozzle opening row. Considering the above, it may be effective to group the nozzle openings for each row (though normally, the nozzle openings using the same color ink are arranged on the same row).

For example, any row of nozzle openings can be specified by a user's manual setting, and the piezoelectric vibrator 13 is driven during the cleaning operation only for the nozzle openings belonging to the specified row. It is preferable that In particular, a dot missing device (for example, see Japanese Patent Laid-Open No. 2001-334651) is installed side by side, and the user opens a nozzle opening array driven by the corresponding piezoelectric vibrator 13 based on the inspection result of the dot missing device. Is preferably specified.

However, the group of nozzle openings specified by the user does not need to be a unit of the row of nozzle openings.

Further, in the above-described embodiment, the example in which the present invention is applied to the ink jet type recording apparatus having the recording head 6 using the piezoelectric vibrator 13 which expands and contracts in the axial direction is shown, but the present invention is not limited to this. Instead, it may be applied to an ink jet recording apparatus having a recording head that expands and contracts the pressure generating chamber 17 by flexural vibration, a bubble jet (registered trademark) recording head, or the like. In this case as well, the same effect is obtained.

The flushing operation or cleaning operation can be performed by moving the carriage to a predetermined flushing position or cleaning position, respectively.

Further, in each of the above embodiments, at least a part of the printer controller 30, the cleaning control means 31, the pump drive means 32, the mode selection means 33, the capping timer 34, and the leaving timer 35 can be realized by a computer system. .

In this case, the computer-readable recording medium 201 in which the programs for realizing the above-mentioned respective elements in the computer system are recorded is also the subject of protection of the present case.

Further, when each of the above-mentioned elements is realized by a program (second program) such as an OS operating on a computer system, a program including various instructions for controlling the program such as the OS (second program) The recording medium 202 in which the program) is recorded is also a protection target of the present case.

Although the above description has been made with respect to the ink jet recording apparatus, the present invention is broadly applicable to all liquid ejecting apparatuses. As an example of the liquid, in addition to ink, glue, nail polish, a conductive liquid (liquid metal) for forming a circuit, or the like can be used. Furthermore, the present invention can be applied to an apparatus for manufacturing a color filter in a display body such as a liquid crystal.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an ink jet recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing an example of an inkjet recording head.

FIG. 3 is a schematic block diagram showing an embodiment of an ink jet recording apparatus according to the present invention.

FIG. 4 is a diagram illustrating an example of a relationship between a capping time and a cleaning mode.

5 is a flowchart showing an operation of the ink jet recording apparatus of FIG.

FIG. 6 is a diagram for explaining another example of the relationship between the capping time and the cleaning mode.

FIG. 7 is a block diagram showing details of a printer controller.

8A and 8B are partially cutaway sectional views showing an inkjet recording head of a conventional example, FIG. 8A is a steady state, FIG. 8B is a state in which a piezoelectric vibrator is contracted, and FIG. 8C is a state in which ink droplets are ejected. is there.

[Explanation of symbols]

1 carriage 2 Timing belt 3 pulse motor (stepping motor) 4 Guide bar 5 recording paper 6 recording head 7 ink cartridges 8 capping device 9 Suction pump 11 bases 12 accommodation room 13 Piezoelectric vibrator 14 flow path unit 15 nozzle opening 16 nozzle plate 17 Pressure generation chamber 18 ink chamber 19 ink supply path 20 flow path forming plate 21 diaphragm 21a Island part 22 Support substrate 23 signal cable 30 Printer controller 31 cleaning control means 32 Pump drive means 33 Mode selection means 34 capping timer 35 Abandoned timer 111 control unit 113 Paper feed motor 131 print engine 132 External interface 133 RAM 134 ROM 135 oscillator circuit 136 Drive signal generation circuit 137 Internal interface 139 Electric drive system for recording head 140 shift register circuit 141 Latch circuit 142 level shifter circuit 143 switch circuit

Claims (22)

[Claims] 1. A plurality of nozzle openings, a plurality of pressure generating chambers that communicate with each nozzle opening and can store a liquid, a plurality of liquid supply paths that supply a liquid to each pressure generating chamber, and a respective pressure generating unit. A head member having a plurality of pressure generating means for ejecting a liquid droplet from each nozzle opening by changing the pressure of the liquid in the chamber, and a suction operation is performed by commonly sucking the liquid from the plurality of nozzle openings. A cleaning unit, a cleaning control unit that drives the cleaning unit, and a cleaning control condition that is set for each group of nozzle openings divided into groups while the cleaning control unit is driving the cleaning unit. And a cleaning assisting means for driving the pressure generating means corresponding to the nozzle openings divided into at least one group. Liquid-jet apparatus characterized by was e. 2. The cleaning auxiliary means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group while the cleaning control means drives the cleaning means. The liquid ejecting apparatus according to claim 1, wherein the pressure generating means corresponding to the nozzle openings divided into other groups is not driven. 3. The liquid ejecting apparatus according to claim 1, wherein the nozzle openings divided into groups are nozzle openings that use the same type of liquid. 4. The nozzle openings classified into the at least one group are nozzle openings specified by a user of the liquid ejecting apparatus.
The liquid ejecting apparatus according to any one of 1. 5. The liquid ejecting apparatus according to claim 1, wherein the nozzle openings divided into the at least one group are nozzle openings that use a highly viscous liquid. 6. A leaving time measuring unit for measuring a leaving time of the head member, wherein the cleaning assisting unit has a leaving time measured by the leaving time measuring unit exceeding a predetermined time. The liquid ejecting apparatus according to claim 1, wherein the pressure generating means corresponding to the nozzle openings divided into the at least one group is driven only in this case. 7. The cleaning aid further comprises: capping means for sealing a nozzle opening of the head member; and capping time measuring means for measuring a capping time during which the head member is sealed by the capping means. The means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group only when the capping time measured by the capping time measuring means exceeds a predetermined time. 6. The method according to claim 1, wherein
The liquid ejecting apparatus according to any one of 1. 8. The driving frequency of the pressure generating means by the cleaning assisting means is variable depending on the viscosity of the liquid used in the nozzle openings divided into the at least one group. Item 8. The liquid ejecting apparatus according to any one of Items 1 to 7. 9. The cleaning assisting means, based on a cleaning control condition set for each group of nozzle openings divided into groups, while the cleaning control means is driving the cleaning means. The pressure generating means corresponding to the nozzle openings grouped into one group is driven, and the nozzle openings grouped into each of the at least two groups are liquids having substantially the same viscosity in each group. The driving frequency of the pressure generating means corresponding to each group of the at least two groups by the cleaning assisting means is determined by the viscosity of the liquid used in the nozzle openings grouped into each group. 9. The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is determined depending on each of them. 10. A nozzle opening, a pressure generating chamber communicating with the nozzle opening and capable of containing a liquid, a liquid supply path for supplying the liquid to the pressure generating chamber, and a nozzle by changing the pressure of the liquid in the pressure generating chamber. A head member having a pressure generating unit for discharging a liquid droplet from the opening; a cleaning unit for sucking the liquid from the nozzle opening to perform a cleaning operation; a cleaning control unit for driving the cleaning unit; Is left unattended, and the cleaning control means is driving the cleaning means when the unattended time measuring means measures the unattended time and the unattended time measured by the unattended time measuring means exceeds a predetermined time. A liquid ejecting apparatus comprising: a cleaning assisting unit that drives a pressure generating unit therebetween. 11. A nozzle opening, a pressure generating chamber communicating with the nozzle opening and capable of containing a liquid, a liquid supply path for supplying the liquid to the pressure generating chamber, and a nozzle by changing the pressure of the liquid in the pressure generating chamber. A head member having a pressure generating unit for discharging a liquid droplet from the opening; a cleaning unit for sucking the liquid from the nozzle opening to perform a cleaning operation; a cleaning control unit for driving the cleaning unit; A capping means for sealing the nozzle opening of the head member, a capping time measuring means for measuring the capping time in which the head member is sealed by the capping means, and a capping time measured by the capping time measuring means for a predetermined time. In the case of
A liquid ejecting apparatus comprising: a cleaning assisting unit that drives a pressure generating unit while the cleaning control unit drives the cleaning unit. 12. A plurality of nozzle openings, a plurality of pressure generating chambers communicating with each nozzle opening and capable of accommodating a liquid, a plurality of liquid supply paths for supplying a liquid to each pressure generating chamber, and each pressure generating. A head member having a plurality of pressure generating means for ejecting a liquid droplet from each nozzle opening by changing the pressure of the liquid in the chamber, and a suction operation is performed by commonly sucking the liquid from the plurality of nozzle openings. A control device for controlling a liquid ejecting apparatus comprising: a cleaning means, wherein the cleaning control means drives the cleaning means, and the cleaning control means drives the cleaning means. Based on the cleaning control condition set for each group of nozzle openings, it corresponds to the nozzle openings grouped into at least one group. Control apparatus characterized by comprising a cleaning auxiliary means for driving the pressure generating means. 13. The cleaning assisting means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group while the cleaning control means is driving the cleaning means. 13. The control device according to claim 12, wherein the pressure generating means corresponding to the nozzle openings divided into other groups are not driven. 14. The control device according to claim 12, wherein the nozzle openings divided into groups are nozzle openings that use the same type of liquid. 15. The nozzle opening classified into the at least one group is a nozzle opening specified by a user of the liquid ejecting apparatus. Control device. 16. The control device according to claim 12, wherein the nozzle openings divided into the at least one group are nozzle openings that use a highly viscous liquid. 17. A leaving time measuring unit for measuring a leaving time of the head member, wherein the cleaning assisting unit has a leaving time measured by the leaving time measuring unit exceeding a predetermined time. 17. The controller according to claim 12, wherein the pressure generating means corresponding to the nozzle openings grouped into the at least one group is driven only in this case. 18. A cleaning assist system, further comprising: capping means for sealing a nozzle opening of the head member; and capping time measuring means for measuring a capping time during which the head member is sealed by the capping means. The means drives the pressure generating means corresponding to the nozzle openings grouped into the at least one group only when the capping time measured by the capping time measuring means exceeds a predetermined time. The control device according to any one of claims 12 to 16, further comprising: 19. The driving frequency of the pressure generating means by the cleaning assisting means is variable depending on the viscosity of the liquid used in the nozzle openings divided into the at least one group. Item 19. The control device according to any one of Items 12 to 18. 20. At least two cleaning assisting means are provided based on a cleaning control condition set for each group of nozzle openings divided into groups while the cleaning control means is driving the cleaning means. The pressure generating means corresponding to the nozzle openings grouped into one group is driven, and the nozzle openings grouped into each of the at least two groups are liquids having substantially the same viscosity in each group. The driving frequency of the pressure generating means corresponding to each group of the at least two groups by the cleaning assisting means is determined by the viscosity of the liquid used in the nozzle openings grouped into each group. 20. The liquid ejecting apparatus according to claim 12, wherein the liquid ejecting apparatus is determined depending on each of them. 21. A nozzle opening, a pressure generating chamber communicating with the nozzle opening and capable of containing a liquid, a liquid supply path for supplying the liquid to the pressure generating chamber, and a nozzle by changing the pressure of the liquid in the pressure generating chamber. A head member having a pressure generating unit for ejecting a liquid droplet from the opening, a cleaning unit for sucking the liquid from the nozzle opening to perform a cleaning operation, and a stand for measuring a standing time of the head member A control device for controlling a liquid ejecting apparatus comprising a time measuring means, wherein a cleaning control means for driving the cleaning means and a leaving time measured by the leaving time measuring means exceeds a predetermined time. A cleaning assisting means for driving the pressure generating means while the cleaning control means is driving the cleaning means. A control device comprising: a step. 22. A nozzle opening, a pressure generating chamber communicating with the nozzle opening and capable of containing a liquid, a liquid supply path for supplying the liquid to the pressure generating chamber, and a nozzle by changing the pressure of the liquid in the pressure generating chamber. A head member having a pressure generating means for discharging a liquid droplet from the opening; a cleaning means for sucking the liquid from the nozzle opening to perform a cleaning operation; a capping means for sealing the nozzle opening of the head member; A controller for controlling the liquid ejecting apparatus, wherein the head member includes a capping time measuring means for measuring the capping time sealed by the capping means, and a cleaning control means for driving the cleaning means; , The capping time measured by the capping time measuring means exceeds a predetermined time. In the case,
A cleaning assisting means for driving the pressure generating means while the cleaning control means is driving the cleaning means.