JP2002036594A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer capable of stably performing flushing operation for discharging air bubbles and preventing a color mixture. SOLUTION: After purging operations (S3, S7, S11, S15) are completed, wiping operations (S4, S8, S12, S16) are respectively performed and, in the flushing operations, at first, flushing by a small ball waveform is performed (S18, S19) and, thereafter, flushing by a large ball waveform is performed (S20, S21).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus having a function of performing a purge operation for sucking ink from an ink ejection nozzle and a flushing operation of ink.

[0002]

2. Description of the Related Art Conventionally, as an ink jet recording apparatus which performs recording such as printing by ejecting ink onto a recording medium such as paper,
For example, an ink jet printer is known. In this inkjet printer, an ink cartridge containing ink is provided so as to be replaceable with respect to a recording head unit having a recording head, ink is supplied from the replaced ink cartridge to the recording head, and ink is ejected from each ejection nozzle. Record.

Further, during use of the ink jet printer, for example, by a user's switch operation or automatically when predetermined conditions are satisfied, the tip side of the ejection nozzle, that is, the nozzle surface where the ejection nozzle is opened A so-called purging operation of sucking ink from is performed.

[0004] The purging operation is to cover the nozzle surface with a suction cap and apply a negative pressure to the suction cap with a suction pump, thereby sucking ink from inside the recording head through the suction cap and removing the ink to the outside. Operation.

In the ink jet printer performing the purging operation, a wipe member is brought into contact with the nozzle surface of the recording head to wipe off ink adhered to the nozzle surface during the purging operation, and the recording head is moved.
A wiping operation for wiping the nozzle surface of the recording head is performed. Further, since the ink is mixed between the ejection nozzles of different colors by the wiping operation, a flushing operation is performed following the wiping operation to remove the mixed ink by the ejection.

[0006]

However, ink adheres to the nozzle surface immediately after the purging operation by suction using the above-mentioned negative pressure. This ink contains many fine bubbles generated by a vigorous ink flow due to the purge operation. On the other hand, the ink in the recording head
As is well known, the function of the porous body in the ink cartridge causes a negative pressure (back pressure) in the pulling-back direction, so that the ink containing bubbles adhering to the nozzle surface is
The back pressure causes the recording head to be drawn into the recording head. Thereafter, a wiping operation for wiping the ink on the nozzle surface is performed, but the air bubbles drawn into the recording head together with the ink cannot be removed. In addition, when a plurality of color ink ejection nozzles are provided on the nozzle surface, another color ink may be pushed into the nozzles by the wiping operation.

As described above, a jetting operation for discharging bubbles and other colors of ink that have entered the recording head, that is, a flushing operation is performed. However, if the jetting is continuously performed at a high frequency, the flow changes rapidly. In this case, the meniscus of the ejection nozzle is destroyed, and it is impossible to shift to the recording operation. If the ejection is performed at a low frequency, there is a problem that it takes much time to discharge bubbles and inks of other colors.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an ink jet printer capable of stably performing a flushing operation for discharging bubbles and preventing color mixing.

[0009]

According to a first aspect of the present invention, there is provided an ink jet recording apparatus for ejecting ink to a recording medium by ejecting ink onto a recording medium. A purge operation of sucking ink in the recording head from the ejection side of the recording head, a wiping operation performed after the purging operation for wiping ink adhered to nozzles of the recording head, and a wiping operation. In an ink jet recording apparatus which performs a flushing operation for ejecting ink in the recording head, which is performed after the operation, the flushing operation includes a small amount of ink droplet ejected for one dot during recording. A driving voltage having a waveform of A driving voltage having a waveform in which the amount of ink droplets ejected to the ink droplets is larger than the ink amount of the small ball waveform, and a flushing operation by a large ball waveform applied to the recording head. The configuration is as follows.

In the ink jet recording apparatus having this configuration,
At the time of the flushing operation, first, a driving voltage having a waveform in which the amount of ink droplets ejected for one dot during recording is small is applied by the small ball waveform applied to the recording head, and then the flushing operation is performed. Since the flushing operation is performed by the large waveform applied to the recording head, a driving voltage having a waveform in which the amount of ink droplets ejected for one dot is larger than the ink volume of the small droplet waveform is performed. In addition, it is possible to perform the ink ejection required for preventing color mixing in a relatively short time, and to suppress the flushing by the large ball waveform in a short time, so that the meniscus is not destroyed.

In the ink jet recording apparatus according to the second aspect of the present invention, in addition to the configuration of the ink jet recording apparatus according to the first aspect, the large ball waveform is larger than the small ball waveform for one dot. The configuration is characterized by having an ejection pulse.

In the ink jet recording apparatus having this configuration,
In addition to the operation of the ink jet recording apparatus according to the first aspect, the large ball waveform can be realized by increasing the pulses of the small ball waveform.

Further, in the ink jet recording apparatus according to the third aspect of the present invention, in order to improve the ejection state of the ink, the recording head ejects the recording head to perform recording by ejecting the ink to the recording medium. A purge operation of sucking ink in the recording head from the side, a wiping operation performed after the purging operation for wiping ink adhered to the nozzles of the recording head, and a wiping operation performed after the wiping operation. In an ink jet recording apparatus that performs a flushing operation for ejecting ink, the flushing operation includes a flushing operation using a stable waveform in which a drive voltage having a small waveform of the pressure fluctuation of the ink in the recording head is applied to the recording head, The drive voltage having a waveform in which the pressure fluctuation of the ink in the recording head is large is performed thereafter. It has a structure, characterized in that by the applied unstable waveform recording head is composed of a flushing operation.

In the ink jet recording apparatus having this configuration,
At the time of the flushing operation, first, the driving voltage having a waveform in which the pressure fluctuation of the ink in the recording head is small is subjected to the flushing operation by the stable waveform applied to the recording head, and then the waveform in which the pressure fluctuation of the ink in the recording head is large. Flushing operation is performed by the unstable waveform applied to the recording head with the drive voltage of the above, so that ink ejection required for discharging bubbles and preventing color mixing can be performed in a relatively short time, and unstable. Since the flushing due to the waveform can be suppressed in a short time, the meniscus is not destroyed.

In the ink jet recording apparatus according to a fourth aspect of the present invention, in addition to the configuration of the ink jet recording apparatus according to the third aspect, the unstable waveform has more ejections per dot than the stable waveform. The configuration is characterized by having a pulse.

In the ink jet recording apparatus having this configuration,
In addition to the operation of the ink jet recording apparatus according to the third aspect, the unstable waveform can be realized by increasing the number of ejection pulses per dot relative to the stable waveform.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the recording apparatus of the present invention will be described below with reference to the drawings. First, an internal configuration of an ink jet printer 1 which is an embodiment of the recording apparatus of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing the internal structure of the inkjet printer 1. FIG. 2 is an enlarged view of the maintenance / recovery mechanism RM.

As shown in FIG. 1, a carriage 8 is provided inside the housing 2 of the ink jet printer 1, and the carriage 8 is slidably supported by a guide rod 11 and a guide member 12, respectively. It is fixed to the belt 13 and driven by the CR motor 16 to reciprocate. A recording head unit 17 having a recording head 18 for performing recording such as printing is attached to the carriage 8. The recording head 18 has four color inks (cyan c, magenta m, yellow y, and black b).
Is an ink jet type in which ink droplets are ejected onto a recording sheet P as a recording medium to perform a recording operation. In order to eject the inks of the respective colors onto the recording sheet P side, cyan, magenta, yellow , Four black nozzle groups.

In the recording head unit 17, four ink cartridges 22y, 22m, 22c and 22b for supplying ink of each color to each ejection nozzle are detachably mounted. The recording head 18 has a large number of (for example, 64) channels (not shown) serving as ink flow paths formed by cutting a large number of concave portions in parallel and linearly in the material of the piezoelectric element. . The channel is opened at the nozzle surface 23 to form a large number of injection nozzles (injection holes).

Therefore, ink can be ejected from a desired ejection nozzle by applying a voltage of a predetermined frequency using the piezoelectric element at the position constituting the wall surface of each channel as an actuator.

Further, in the ink jet printer 1 of the present embodiment, as shown in FIG. 1, a platen roller 25 for conveying the recording paper P is provided at a position facing the recording head 18, and the platen roller 25 is The recording paper P is conveyed in the direction of the arrow shown in FIG. 1 by rotation of the LF motor 24 shown in FIG.

As shown in FIG. 1 and FIG.
In the lower left portion (in FIG. 1), a maintenance / recovery mechanism RM for maintaining / recovering the ink ejection operation of the recording head 18 is provided. The maintenance / recovery mechanism RM may cause the ink to dry during use of the recording head 18, generate air bubbles therein, or cause ink droplets to adhere to the nozzle surface 23 of the ejection nozzle. A suction unit 26 for eliminating jetting failures that occur, and an ink jet printer 1
A storage cap 27 that covers the nozzle surface 23 to prevent drying of the ink when not in use, and a wiper member 28 that wipes the nozzle surface 23. Further, as shown in FIG. 1, a flushing receiving member 7 for receiving ink ejected from the recording head 18 is provided at a right end (in FIG. 1) inside the housing 2. The flushing receiving member 7 is made of a material having a high ink hygroscopic property such as felt.

The suction means 26 is provided for the recording head 1.
8, a suction cap 33 capable of contacting and separating from the surface 23 of each ejection nozzle;
And a suction pump for sucking ink through the suction cap 33 when in close contact with the ink. The suction means 26 is provided with a suction cap 33 and a wiper member 2 by a cam member 36 and a cam drive motor (not shown).
8 is moved toward and away from the recording head 18, and the suction pump 34 is driven to perform a suction operation (purge operation) via the suction cap 33.

Next, the electrical configuration of the ink jet printer 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a block diagram illustrating an electrical configuration of the inkjet printer 1.

As shown in FIG. 3, the ink jet printer 1 has a control 1 for controlling the entire ink jet printer 1.
A CPU 50 having a chip configuration is provided.
A RAM 51 for temporarily storing data and a ROM 52 for storing various control programs are connected via a data bus B1 and an address bus B2. Also, CP
A control circuit 57 composed of a gate array is connected to U50 via a data bus B1 and an address bus B2, and an image memory 58 for developing print data and a personal computer 60 are connected to the control circuit 57. The Centronics interface 59 is connected.

Here, the CPU 50 generates a print timing signal TS and a control signal RS according to the program stored in the ROM 52 and transfers them to the control circuit 57. In the control circuit 57, the print timing signal TS and the control signal R
In accordance with S, based on the image data stored in the image memory 58, transfer data DATA for printing for forming the image data on the recording paper P, a transfer clock TCK synchronized with the transfer data DATA, a strobe signal STB , A print clock ICK to generate a drive circuit 61
Transfer to Further, the control circuit 57 generates a Centronics data interrupt signal WS based on the Centronics data transferred from the external device such as the personal computer 60 via the Centronics interface 59, and transfers it to the CPU.

A drive circuit 61 is connected to the control circuit 57 via a harness cable 62, and transfer data DATA for printing, a transfer clock TCK, a strobe signal STB, and a print clock ICK are transmitted from the control circuit 57 to the drive circuit 61. Is input to These transfer data for printing DA
The TA, the transfer clock TCK, the strobe signal STB, and the print clock ICK are low voltage signals of approximately 5V.

The drive circuit 61 is connected to the recording head 18 via a harness cable 63. Since the recording head 18 is composed of a shear mode piezoelectric actuator, a signal flowing through the harness cable 63 is provided. Is a relatively high voltage signal of about 20V.
Note that the harness cables 62 and 63 are made of a flexible printed circuit board.

An operation panel 53 for inputting various commands is connected to the CPU 50. Further, C
The PU 50 is connected to a CR motor 16 for driving the carriage 8 via a CR motor drive circuit 54.
The LF motor 24 that drives the platen roller 25 via the LF motor drive circuit 55 is connected to the PU 50. Further, a maintenance / recovery mechanism drive circuit 56 is connected to the CPU 50, and the maintenance / recovery mechanism drive circuit 56
It is configured to control the maintenance / recovery mechanism RM.

Next, the configuration of the drive circuit 61 will be described with reference to FIG. FIG. 4 is a diagram showing the internal configuration of the drive circuit 61.

As shown in FIG. 4, the drive circuit 61 includes a serial / parallel converter 71, a data latch 72, an AND gate 73, and an output circuit 74. The serial / parallel converter 71 includes a shift register having the same bit length as the number of ink channels in the recording head 18.
7, the print transfer data DATA serially transferred in synchronization with the transfer clock TCK is input and converted into parallel data PD0 to PD63. Data latch 72
Is the strobe signal S transferred from the control circuit 57.
As the TB rises, each of the parallel data PD0 to PD0
Latch PD63.

The AND gate 73 takes the logical product of the parallel data PD0 to PD63 output from the data latch 72 and the print clock ICK transferred from the control circuit 57, and generates drive data A0 to A63. The output circuit 74 generates a 20V pulse signal based on the drive data A0 to A63, and outputs the output signal to a piezoelectric element actuator provided in the print head 18.

Next, a maintenance process of the ink jet printer 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a maintenance process of the ink jet printer 1, and FIG. 6 is a driving waveform diagram of ink ejection used in the ink jet printer 1. The maintenance processing program shown in FIG. 5 is stored in the ROM 52 shown in FIG.
This is executed by U50.

In the ink jet printer 1, after the replacement of the ink cartridges 22y, 22m, 22c, 22b, a maintenance process (initial purge) at the time of initial introduction is performed. Also, when the user finds a missing pixel or the like in printing, a maintenance process is performed by operating a purge button (not shown) provided on the operation panel 53. Further, when a predetermined time has elapsed from the previous maintenance processing, the maintenance processing is automatically performed.

As shown in FIG. 5, when the maintenance process is started, the color of the ejection nozzle for which the ink cartridge has been replaced or the purge process has been instructed by the purge button or the like is determined (S1, S5, S9, S9). S13). If the ejection nozzle to be purged is a black ink ejection nozzle (S1: YES), the carriage 8 is moved so that the black ink ejection nozzle of the recording head 18 faces the suction cap 33. (S2).

Next, the suction cap 33 is attached to the recording head 18.
Then, the suction pump 34 is driven to perform a purge operation (suction operation) via the suction cap 33 (S3). Next, the carriage 8
Is moved, and the wiper member 28 wipes off the jet nozzle surface of the recording head 18 for black ink (S4).
The process proceeds to S5. If it is determined in step S1 that the purging operation of the black ink ejection nozzle of the recording head 18 is not to be performed (S1: NO), step S1 is performed.
The process proceeds to the determination of step 5.

If the ejection nozzle to be purged is a yellow ink ejection nozzle (S5: YE
S) The carriage 8 is moved to move the ejection nozzle of the recording head 18 for yellow ink to a position facing the suction cap 33 (S6).

Next, the suction cap 33 is attached to the recording head 1.
Then, the suction pump 34 is driven to perform a purge operation (suction operation) via the suction cap 33 by contacting the yellow ink ejection nozzle 8 (S7). Next, the carriage 8 is moved and the recording head 18 is moved by the wiper member 28.
Wipe the yellow ink jet nozzle surface (S
8), the process proceeds to S9. If it is determined in step S5 that the purging operation of the yellow ink ejection nozzle of the recording head 18 is not performed (S5: N
O), proceed to the determination of S9.

If the ejection nozzle to be purged is a cyan ink ejection nozzle (S9: YE
S), the carriage 8 is moved to move the cyan ink ejection nozzle of the recording head 18 to a position facing the suction cap 33 (S10).

Next, the suction cap 33 is attached to the recording head 1.
Then, the suction pump 34 is driven in contact with the cyan ink ejection nozzle 8 to perform a purge operation (suction operation) via the suction cap 33 (S11). Next, the carriage 8 is moved and the recording head 18 is moved by the wiper member 28.
Wipe the cyan ink jet nozzle surface (S1).
2) The process proceeds to S13. If it is determined in step S9 that the purging operation of the cyan ink ejection nozzle of the recording head 18 is not performed (S9: N
O), the process proceeds to S13.

When the ejection nozzle to be purged is a magenta ink ejection nozzle (S13: YE
S), the carriage 8 is moved to move the magenta ink ejection nozzle of the recording head 18 to a position facing the suction cap 33 (S14).

Next, the suction cap 33 is attached to the recording head 1.
Then, the suction pump 34 is driven by making contact with the magenta ink ejection nozzle 8 to perform a purge operation (suction operation) via the suction cap 33 (S15). Next, the carriage 8 is moved and the recording head 1 is moved by the wiper member 28.
8 wipes the magenta ink jet nozzle surface (S1
6) The process proceeds to S17.

Next, the recording head 18 is moved to the flushing position (S17). Specifically, the carriage 8 is moved to the right end (in FIG.
The recording head 18 is made to face the flushing receiving member 7 (S17).

Next, the process of S18 is performed. In S18, a flushing operation of ejecting 500 ink droplets with a small bead waveform is set for the ejection nozzle that has performed the purge operation (S18). This setting is stored in the RAM 51 shown in FIG. The driving waveform data for performing the flushing operation using the small bead waveform is stored in the ROM 52 shown in FIG. A specific example of the small ball waveform will be described later.

Next, when the processing of S18 is completed, a flushing operation of 500 ink droplets with a small bead waveform is performed on the ejection nozzle that has been previously purged (S1).
9). This process is performed by the CPU 50 shown in FIG. 3 using the small droplet waveform stored in the RAM 51 in S18.
By transmitting a drive signal from the drive circuit 61 to the print head 18 via the control circuit 57 based on the data of the zero ejection, ink droplets are ejected from the corresponding ejection nozzle as shown in FIG. It is injected to the flushing receiving member 7 (S19).

When the flushing operation of S19 is completed,
Next, the process of S20 is performed. In S20, the flushing operation of 1000 droplets of ink droplets is set for the ejection nozzle that has performed the purge operation by using a large-sized waveform having a larger amount of ink than the small-sized waveform (S2).
0). This setting is stored in the RAM 51 shown in FIG. The driving waveform data for performing the flushing operation using the large ball waveform is stored in the ROM 52 shown in FIG. A specific example of the large ball waveform will be described later.

In the process of S20, since the flushing operation with the large ball waveform is also performed for the ejection nozzle that has not been purged, the ink droplet 5 with the large ball waveform is used.
00 injection is set (S20). This setting is shown in FIG.
Is stored in the RAM 51 shown in FIG.

Next, when the process of S20 is completed, a flushing operation is performed on the ejection nozzles set to eject 1000 or 500 ink droplets by the large ball waveform (S21). This processing is performed by the CPU shown in FIG.
50 sends a drive signal with a large-sized waveform from the drive circuit 61 to the print head 18 via the control circuit 57 based on data of ejection of 1000 or 500 ink droplets with a large-sized waveform stored in the RAM 51. , FIG.
As shown in (B), ink droplets are ejected from the corresponding ejection nozzle to the flushing receiving member 7 (S2).
1). Thereafter, the maintenance process ends, and the inkjet printer 1 enters a standby state.

Next, with reference to FIGS. 6 and 7, the small ball waveform and the large ball waveform will be described. FIG. 6A is a driving waveform of a small bead waveform for driving the recording head 18, and FIG.
(B) is a driving waveform of a large ball waveform for driving the recording head 18.

Here, the length (depth) of the channels in the ejection nozzles of the four colors cyan, magenta, yellow, and black of the recording head 18 is "L", and the sound velocity in the ink in the channels is "L". a ", the one-way propagation time T = L / a of the pressure wave in the channel is obtained. The small ball waveform and the large ball waveform will be described using this “T”. An example of T is “8 μs”.

As shown in FIG. 6 (A), when the small ball waveform first rises, it turns on at a voltage value of approximately 20 V and becomes 1T.
After continuing for the time, it falls and turns off. At the falling timing, as shown in FIG. 7A, one drop of ink is ejected from the ink nozzle. Then, after a lapse of 2.5T from the falling timing, it turns on at a voltage value of approximately 20 V, and after 0.5T, it falls and turns off. The pulse lasting 0.5 T is a cancellation pulse for canceling the residual pressure fluctuation in the channel. It should be noted that the small bead waveform is one cycle of the print clock 1CK, that is, one dot as described above.
Since the droplet is ejected only and the pressure fluctuation in the channel is small, the waveform does not cause non-ejection even when ejected continuously for a long time.

Next, the large ball waveform will be described. FIG.
As shown in (B), when the large ball waveform first rises,
It turns on at a voltage value of about 20 V, and after falling for 1T, falls and turns off. At the falling timing, as shown in FIG. 7B, one drop of ink is ejected from the ink nozzle. Then, 1T time after the falling timing, the voltage value becomes approximately 20 V again.
And after continuing for 1T time, it falls and becomes OFF. At the timing of this fall, FIG.
As shown in (B), the second ink droplet is ejected from the ink nozzle. Then, after 1T time from the falling timing, it is turned on again at a voltage value of approximately 20 V, and after continuing for 1T time, it falls and is turned off. At the falling timing, as shown in FIG. 7B, the third ink droplet is ejected from the ink nozzle.

Then, 1T after the falling timing, it is turned on again at a voltage value of about 20 V, and
After continuing for T time, it falls and turns off.
At the falling timing, as shown in FIG. 7B, the fourth ink droplet is ejected from the ink nozzle.
After a lapse of 2.5T from the last falling timing, it turns on at a voltage value of approximately 20 V, and falls and turns off after a lapse of 0.5T. The pulse lasting 0.5 T is a cancellation pulse for canceling the residual pressure fluctuation in the channel. In the large ball waveform, print clock 1
The above-described waveform is output within one cycle of CK, and eventually four drops of ink are ejected for one dot.
As shown in (B), a large dot is formed at the landing position as compared with the dot by the small ball waveform. The large ball waveform is a waveform in which the pressure fluctuation in the channel is large.

More specifically, if the operation of outputting a plurality of pulses for one dot is continued, the residual vibration of the ink itself is gradually amplified, and a flow of the ink which changes rapidly in the channel or the manifold is generated. If this operation is continued for a very large number of dots (for example, 10,000 shots or more, or one line or more of the printer), the meniscus of the nozzle may be excessively concave and air may be drawn in as it is, resulting in non-ejection. The large ball waveform of the present embodiment is an unstable waveform in the sense that a non-injection may occur.

As described above, in the ink jet printer according to the present embodiment, during the flushing operation, first, the flushing operation is performed by the small ball waveform, which is a waveform in which the pressure fluctuation in the channel is small with respect to the ejection nozzle on which the purge operation has been performed. Is performed. Since the bubbles are drawn into the channel by the back pressure together with the ink attached to the nozzle surface by this purge operation, the bubbles relatively close to the nozzle surface and the relatively large bubbles are discharged. Next, a flushing operation with a large ball waveform, which is a waveform having a large pressure fluctuation in the channel, is performed for all the ejection nozzles, and the ink pushed into each nozzle by the wiping operation is discharged, that is, as much as necessary to prevent color mixing. And ejects the air bubbles remaining in the channels and the manifold and the air bubbles adhering to the wall surface by violent flow. At this time, the flushing operation of the large ball waveform is not continued to such an extent that the meniscus of the nozzle becomes too large and falls into non-ejection.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present embodiment. For example,
In the above-described embodiment, the ink jet printer has been described. However, the present invention can be applied to various recording apparatuses such as a facsimile. Instead of the small and large ball waveforms, the recording head may be initially driven at a low frequency during flushing, and then driven at a high frequency.

[0056]

As described above in detail, in the ink jet recording apparatus according to the first aspect of the present invention, during the flushing operation, first, the amount of ink droplets ejected for one dot during recording is small. A flushing operation is performed by a small-drop waveform applied to the recording head with a drive voltage having a waveform as follows, and then the amount of ink droplets ejected for one dot is larger than the amount of ink in the small-drop waveform. Since the flushing operation is performed by the large-sized waveform applied to the recording head with the drive voltage having the following waveform, it is possible to perform the ejection of the ink necessary for the discharge of bubbles and the prevention of color mixing in a relatively short time, and Since the flushing due to the waveform can be suppressed in a short time, the meniscus is not destroyed.

Further, in the ink jet recording apparatus according to the second aspect of the present invention, in addition to the effect of the ink jet recording apparatus according to the first aspect, the large ball waveform can be realized by increasing the pulses of the small ball waveform. Therefore, it is not necessary to provide a special additional circuit in the control circuit of the ejection pulse.

In the ink jet recording apparatus according to the third aspect of the present invention, at the time of the flushing operation, first, a driving voltage having a waveform in which the pressure fluctuation of the ink in the recording head is small is applied by a stable waveform applied to the recording head. Is performed, and then a driving voltage having a waveform in which the pressure variation of the ink in the print head is large is subjected to a flushing operation based on an unstable waveform applied to the print head.
Injection of ink required for air bubble discharge and color mixing prevention can be performed in a relatively short time, and flushing due to an unstable waveform can be suppressed in a short time, so that the meniscus is not destroyed.

According to a fourth aspect of the present invention, in addition to the effect of the third aspect of the present invention, in addition to the effect of the third aspect of the present invention, the unstable waveform is obtained by ejecting a pulse from the stable waveform for one dot. Can be realized by increasing Therefore, it is not necessary to provide a special additional circuit in the control circuit of the ejection pulse.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an internal structure of an inkjet printer 1. FIG.

FIG. 2 is an enlarged view of a maintenance / recovery mechanism RM.

FIG. 3 is a block diagram showing an electrical configuration of the inkjet printer 1.

FIG. 4 is a diagram showing an internal configuration of a drive circuit 61.

FIG. 5 is a flowchart illustrating a maintenance process of the inkjet printer 1.

FIG. 6 is a driving waveform diagram of ink ejection used in the ink jet printer 1.

FIG. 7 is a diagram showing small ball injection and large ball injection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet printer 2 Case 7 Flushing receiving member 8 Carriage 18 Recording head 22y, 22m, 22c, 22b Ink cartridge 23 Nozzle surface 25 Platen roller RM Maintenance / recovery mechanism 26 Suction unit 27 Storage cap 28 Wiper member 33 Suction cap 36 Cam member 50 CPU 51 RAM 52 ROM 53 Operation panel 57 Control circuit 58 Image memory 61 Drive circuit P Recording paper

Claims (4)

[Claims] 1. A purging device for ejecting ink from a jet side of a recording head to a recording head for performing recording by ejecting ink to a recording medium in order to improve an ejection state of the ink. Ink jet recording that performs an operation, a wiping operation performed after the purging operation for wiping ink adhered to nozzles of the recording head, and a flushing operation performed after the wiping operation to eject ink in the recording head. In the apparatus, the flushing operation includes: a flushing operation using a small ball waveform applied to the recording head, the driving voltage having a waveform in which the amount of ink droplets ejected for one dot during printing is small; Of a waveform in which the amount of ink droplets ejected for one dot is larger than the amount of ink in the small ball waveform. An ink jet recording apparatus characterized by dynamic voltage is composed of a flushing operation by the applied Ootama waveform to the recording head. 2. The ink jet recording apparatus according to claim 1, wherein the large ball waveform has more ejection pulses than the small ball waveform for one dot. 3. A purge for sucking ink in the recording head from the ejection side of the recording head in order to improve the ejection state of the ink with respect to a recording head that performs recording by ejecting ink to a recording medium. Ink jet recording that performs an operation, a wiping operation performed after the purging operation for wiping ink adhered to nozzles of the recording head, and a flushing operation performed after the wiping operation to eject ink in the recording head. In the apparatus, the flushing operation includes a flushing operation by a stable waveform in which a drive voltage having a small waveform of the pressure fluctuation of the ink in the recording head is applied to the recording head, and a pressure fluctuation of the ink in the recording head performed thereafter. Flushing due to an unstable waveform when a drive voltage having a large waveform is applied to the recording head An ink jet recording apparatus characterized in that it is composed of a. 4. The unstable waveform according to claim 1, wherein:
The inkjet recording apparatus according to claim 3, wherein the inkjet recording apparatus has more ejection pulses than the stable waveform.