JP2000158677A - Flushing position adjustment device in ink jet recording device - Google Patents

Abstract

(57) [Problem] To provide an ink jet recording apparatus capable of improving the throughput and reducing the size of the apparatus. SOLUTION: A plurality of recording heads 12a and 12b are mounted on a carriage 11, and printing is performed while each recording head moves in the direction in which these recording heads are arranged.
It is configured to flush ink droplets to 5, 26. Adjusting amount input means for adjusting an output timing of a flushing control signal to be supplied to each of the recording heads 12a and 12b; and outputting of a flushing control signal to each recording head using the adjustment value input at the adjusting amount input means. It is configured to determine timing.

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 in which a plurality of recording heads are mounted on a carriage and printing is performed while each recording head moves in the direction in which these recording heads are arranged. The present invention relates to a flushing position adjusting device of a recording apparatus configured to flush ink droplets to a flushing area in a state.

[0002]

2. Description of the Related Art Ink jet recording apparatuses have been used in many types of printing including color printing in recent years, since noise at the time of printing is relatively small and small dots can be formed at a high density. Such an ink jet recording apparatus includes an ink jet recording head that receives supply of ink from an ink cartridge, and a paper feeding unit that moves recording paper relative to the recording head, and records the recording head on a carriage. Recording is performed by ejecting ink droplets onto the recording paper while moving in the width direction of the paper. The carriage is equipped with a recording head that can eject black ink and each color ink of yellow, cyan, and magenta, and not only text printing with black ink, but also full-color printing by changing the ejection ratio of each ink. It is possible.

In such an ink jet recording head, the ink pressurized in the pressure generating chamber is ejected as ink droplets from a nozzle opening onto recording paper to perform printing. There is a problem that printing failure occurs due to an increase in viscosity, solidification of the ink, adhesion of dust, and mixing of air bubbles. For this purpose, the ink jet recording apparatus is provided with capping means for sealing the nozzle openings of the recording head during non-printing.

The capping means not only functions as a lid for preventing the ink from being dried at the nozzle openings when printing is stopped, but also seals the nozzle plate when the nozzle openings are clogged. It also has a function of sucking ink from the nozzle opening by the negative pressure from the suction pump and eliminating clogging due to solidification of the ink in the nozzle opening and ink ejection failure due to air bubbles entering the ink flow path. .

[0005] Forcible suction and discharge processing of ink for eliminating the clogging of the recording head and the state of air bubbles mixed into the ink flow path is usually called a cleaning operation, and the printing operation is performed after the apparatus has been stopped for a long time. Is restarted, or when the user operates the cleaning switch to eliminate the deterioration of the quality of the recorded image, an operation of discharging ink droplets by negative pressure is performed.

[0006] The recording head is also provided with a function of applying a drive signal unrelated to printing to discharge ink droplets idle. This is called a flushing operation, and the recording operation is performed by wiping during a cleaning operation. This operation is performed at regular intervals in order to recover irregular meniscuses near the nozzle opening of the head, and to prevent clogging due to thickening of ink in the nozzle opening that discharges a small amount of ink droplets during printing. .

[0007]

Incidentally, recently, there has been a demand for the above-mentioned recording apparatus to have a large amount of printing capability and a high printing speed. Along with this, in the cleaning process and the flushing process as the recovery process of the printing function in the recording head, it is necessary to handle a large amount of ink ejection, and the capping unit uses both the cleaning process and the flushing process. In such a case, there is a problem that it is impossible to discharge a large amount of waste ink. For this reason, a recording apparatus has been developed in which an area dedicated to flushing is set and the area is flushed.

In the flushing process,
In a predetermined flushing area, a processing routine is employed in which the carriage motor is stopped and flushing is performed, and subsequently a printing operation is performed, so that the throughput cannot be improved. I have Further, for example, when a plurality of recording heads are mounted on a carriage and printing is performed while each recording head moves in the direction in which these recording heads are arranged, a width equivalent to the width of the plurality of recording heads in the carriage traveling direction is used. Since a flushing area larger than the width is required, the apparatus is inevitably increased in size.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and is configured so that each of the recording heads flushes the flushing area at a timing corresponding to each other in a moving state of the carriage.
It is an object of the present invention to provide a recording apparatus which has solved the above-mentioned problems. Another object of the present invention is to provide a recording apparatus that includes an input unit for an adjustment value for adjusting the flushing timing and that can execute a flushing operation with high accuracy on a flushing area.

[0010]

According to the present invention, there is provided a flushing position adjusting apparatus for an ink jet recording apparatus, comprising: a plurality of recording heads mounted on a carriage; A flushing position adjusting device in a recording apparatus configured to print while moving each recording head in the direction in which the recording head moves, and to flush ink droplets to a flushing area in a moving state of the carriage. An adjustment amount input unit for adjusting an output timing of a flushing control signal given to the head, wherein an output timing of the flushing control signal for each recording head is determined using the adjustment value input by the adjustment amount input unit. Is done.

In this case, the adjustment value of the output timing of the flushing control signal in each recording head input by the adjustment amount input means is set to a predetermined reference position corresponding to the flushing area in any one recording head. It is desirable to configure so as to be input as a correction value.

Preferably, a correction value for a preset reference position corresponding to a flushing area in any one of the recording heads is managed by a pulse number, and a correction value for the reference position in another recording head is , And is controlled by the delay time.

The correction value for a preset reference position corresponding to a flushing area in any one of the recording heads and the correction value for the reference position in another recording head are managed by the number of pulses. May be configured.

In any of the above-mentioned embodiments, in any of the preferred embodiments, any one of
The preset reference position corresponding to the flushing area in one recording head is determined by an encoder signal generated with the movement of the carriage.

In a preferred embodiment, the correction value is stored in a non-volatile memory, and each of the flushing control signals is calculated based on an encoder signal generated as the carriage moves and the correction value stored in the memory. The output timing is determined. In addition, in a preferred embodiment, the width of the flushing area in the carriage traveling direction is made smaller than the width of the plurality of recording heads in the carriage traveling direction.

According to the ink jet type recording apparatus constructed as described above, each recording head performs a flushing operation in accordance with each timing while moving on the carriage, thereby discharging ink droplets to the flushing area. Is done. Therefore, the throughput can be improved, and the width of the flushing area can be set smaller, so that the size of the recording apparatus can be reduced.

Further, according to the flushing position adjusting device according to the present invention, the correction value of the output timing of the flushing control signal given to each recording head can be input by the adjustment amount input means, and based on this correction value, The ejection timing of flushing by the recording head is corrected. Therefore, in each printing apparatus, the accuracy of the ejection timing of the flushing by each print head can be improved, and the landing position of the ink droplet by the flushing can be specified in a narrower area, so that the width of the flushing area is further increased. It can be formed narrow.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a flushing position adjusting device in an ink jet type recording apparatus according to the present invention will be described based on an embodiment shown in the drawings. 1 to 3 show the configuration of a large-sized ink jet recording apparatus (hereinafter, also referred to as a printer) directly applied to a floor to which the present invention is applied. FIG. 1 is an external perspective view of the printer. FIG. 2 is a front view of the internal configuration of the printer. FIG. 3 is a longitudinal sectional view showing a state in which a flushing area portion described later in FIG. 2 is broken.

In this printer, a paper feed unit 1, a printing unit 2, and a discharge stack unit 3 are arranged in an upper, middle, and lower positional relationship. A paper transport path from the paper supply unit 1 to the paper discharge stack unit 3 via the printing unit 2 is formed substantially straight from the obliquely upper back side to the obliquely lower front side. As shown in FIGS. 2 and 3, the paper supply unit 1 is configured so that a long roll paper 4 as a recording medium having a paper width of, for example, 40 inches or more can be disposed, and can be removed at the time of replacement. The paper feed unit 1 is configured to have a height suitable for performing the work of exchanging the roll paper 4 with the worker standing.

In the embodiment, as shown in FIGS. 1 and 3, the front surface of the roll paper 4 attached to the paper feed unit 1 can be covered by a roll paper cover 5 that can be opened and closed. When the cover 5 is closed, the upper surface of the cover 5, the printing unit 2, and a paper ejection guide 6, which will be described later, are substantially flush with each other, and have a rigidity different from that of the roll paper 4. It is configured to be able to supply and discharge thick paper and the like.

As shown in FIG. 2, the sheet feeding section 1 further includes a pair of spindle receivers 8a and 8b below a pair of spindle receivers 7a and 7b. These spindle receivers are respectively mounted on a pair of left and right frames 9, 9 in the printer body. And
Both ends of two long spindles 7, 8 on which roll papers 4, 4 are mounted, respectively,
It is laid horizontally between a and 7b and between 8a and 8b.

As can be understood from FIGS. 1 and 2, the two spindles 7 and 8 are mutually moved so that the relatively upper spindle 7 is slightly rearward with respect to the worker standing in front of the apparatus. They are arranged diagonally up and down. Each of the roll papers 4 is configured to be conveyed along a paper conveyance path that is formed substantially linearly obliquely up and down toward the entrance of the discharge stack unit 3 via the printing unit 2.

As shown in FIG. 2, a guide rod 10 is provided in the printing unit 2 so as to be horizontal between the left and right frames 9 and 9 so that the guide rod 10 can be moved left and right on the guide rod 10. The first recording head 12a and the second carriage 11 are attached to the carriage 11.
Are mounted side by side in the moving direction of the carriage 11. Then, the recording heads 12a, 12
Below the scanning area b, a flat paper discharge guide 6 forming a part of the paper transport path is formed.

The paper discharge stack 3 is a portion for receiving printed paper, and the paper discharge stack 3 is a stack cloth 13 whose paper receiving surface is made of a foldable cloth sheet.
It is formed with. Then, as shown in FIG. 3, the printed paper is transferred to the printing unit 2 by the paper discharge switching lever 14.
Of the stack cloth 1 on the front floor of the printer body (not shown).
3 is developed so that the sheet can be guided to a second receiving portion that is temporarily formed on the front side.

Then, the printed paper is transferred to the first receiving portion 15.
And the upper edge 13a of the stack cloth 13 protruding onto the paper transport path by the paper discharge switching lever 14 when the paper ejection guide 6 is formed below the printing unit 2. Is formed by forming an opening 16 therebetween.

When the printed sheet is guided to the second receiving portion, the upper edge 13a of the stack cloth 13 is retracted backward from the sheet transport path by the discharge switching lever 14, and the stack cloth fixing lever 17 is moved. Is pulled out to the front side, and the hook 18 to which the leading end of the stack cloth 13 is fixed is engaged with the front end of the fixing lever 17, so that the stack cloth 13 can be deployed to the front side of the printer body. ing.

As shown in FIG. 2, one end of the traveling area of the recording heads 12a and 12b mounted on the carriage 11 is formed as a non-printing area (home position), and the capping means 21 is disposed in the non-printing area. Have been. The nozzle forming surface of the recording head 12 is mounted on the carriage 11 in a state where it is slightly inclined from the vertical direction, and the capping unit 21 moves the recording heads 12a and 12b when the recording head 12 moves to the non-printing area. Two cap members corresponding to the respective recording heads are arranged so that the respective nozzle forming surfaces can be sealed. A suction pump 22 for applying a negative pressure to the internal space of the cap member is disposed below the capping means 21.

The capping means 21 functions as a lid for preventing the nozzle openings of the recording heads 12a and 12b from drying during the idle period of the recording apparatus. In addition, the capping means 21 applies the negative pressure from the suction pump 22 to the recording heads 12a and 12b. And also has a function as a head cleaning means for sucking ink. The waste ink sucked by the suction pump 22 is discharged to a first waste liquid tank 23 and is absorbed by a waste liquid absorbing material 23a housed in the tank.

On the other hand, a first flushing area 25 is formed on the moving path of the recording heads 12a and 12b adjacent to the capping means 21, and the first flushing area 25 is provided with an ink receiving unit 27. Is disposed, and the waste ink collected by the ink receiving unit 27 is discharged to the first waste liquid tank 23, and is absorbed by the waste liquid absorbing material 23a accommodated in the tank. .

Also, a second flushing area 26 is formed at the other end opposite to the capping means 21 via the central printing area. Also in the second flushing area 26, an ink receiving unit 27 is disposed, and the waste ink collected by the ink receiving unit 27 is discharged to a second waste liquid tank 28,
It is configured to be absorbed by the waste liquid absorbing material 28a accommodated in the tank.

A porous sheet 27a is disposed at the opening of each ink receiving unit 27, receives ink droplets generated by flushing from the recording head, and introduces the ink droplets into a case constituting the unit 27. Are configured to be absorbed by the waste liquid absorbents 23a and 28a, respectively.

The ink receiving units 27 in the flushing area have substantially the same configuration, and the width W1 in the carriage traveling direction is the same as the width W2 in the carriage traveling direction over the first and second recording heads 12a and 12b. In contrast, it is configured to be small. More specifically,
The first and second recording heads 12a and 12b are formed to be slightly larger than their respective widths.

The first and second flushing areas are set according to, for example, the width of the paper to be printed.
A flushing sequence that is appropriately selected and used is introduced, so that the reliability of printing by flushing can be ensured without lowering the throughput.

On the other hand, as shown in FIG. 3, a cartridge holder 31 on which ink cartridges are loaded is disposed on the left and right sides of the printing unit 2 in the recording apparatus. The cartridge holder 31 is configured to be rotatable by approximately 45 degrees, and forms a cartridge replacement mode in which the ink cartridge can be replaced at one rotation end (a longitudinal direction is obliquely 45 degrees). At the same time, at the other rotating end (the longitudinal direction is horizontal), the ink supply mode to the recording head side is set.

FIGS. 4 to 6 show the operation and configuration of the flushing position adjusting device mounted on the above-mentioned recording apparatus. As described above, the width W1 in the carriage traveling direction of each of the ink receiving units 27 arranged in the first and second flushing areas 25 and 26 is the width in the carriage traveling direction across the first and second recording heads 12a and 12b. It is configured smaller than W2. This is because each recording head 12
Since the flashing is controlled by the predetermined timings a and 12b, the ink droplets ejected by the flashing can be reliably collected by the respective ink receiving units 27 even in the aforementioned relationship of the width. This is because it can be done.

In order to realize such an operation, it is necessary to adjust the output timing of the flushing control signal given to the first and second recording heads 12a and 12b.
FIG. 4 is a timing chart showing an adjustment method in the adjustment device. As shown in FIG. 4, a linear encoder signal is used as a preset reference position corresponding to the flushing area. This linear encoder signal is obtained by reading a mark or a magnetic scale arranged in a band along the traveling direction of the carriage by a sensor arranged on the carriage.

The linear encoder signals shown in FIG. 4 are denoted by N-1,..., N + 2 for convenience of explanation. An NCHG (nozzle charge) signal applied to each of the first and second heads is a flushing signal that ejects ink from all nozzles of each head when this signal is in a “High” (hereinafter referred to as “H”) state. State.

First, in the adjustment of the flushing position of the first head, the N-th encoder signal from the home position is used as a reference position, and based on the N-th signal, the NCHG signal of the first head at this timing is " H ". And the second
Similarly, the adjustment of the flushing position of the head is tentatively set so that the NCHG signal of the second head becomes “H” at a timing delayed by T (μsec) with the Nth encoder signal from the home position as a reference position. I have. Therefore, these two temporary flushing positions are the reference in the design of the apparatus.

FIG. 5 shows the accuracy with which a correction value is added to the temporary flushing position described with reference to FIG. 4 so that the ink droplet can reliably fly into the opening of the ink receiving unit 27 during the movement of the recording head. 9 shows an operation procedure of the adjustment amount input means for obtaining a high flushing position. The input of the adjustment amount is performed, for example, when the product is shipped from the factory, and can also be performed by an end user.

First, in step S11 of FIG.
= 0 and t = 0. N is a correction value for the reference position N of the encoder signal, and n is managed by the number of pulses. Further, t is a correction value for a time obtained by adding the delay time T to the reference position N of the encoder signal. Therefore, t is managed as a delay time. The values of n and t are initially set to "0" as described above.

Then, the process proceeds to step S12. In this state, since n = 0 as described above, the NCHG signal of the first head becomes "H" at the N-th signal (design reference). It is set as follows. Then, step S1
In 3, a flushing operation is performed to determine whether the flushing position of the first head is appropriate. If it is determined in step S13 that the flushing position of the first head is appropriate (Yes), the operation proceeds to step S15. If it is determined that the flushing position of the first head is not appropriate (No), In step S14, the value of n is input.

As the value of n, an appropriate value of n is input based on the result of the flushing performed in step S13 according to the experience and feeling of the adjuster to some extent, and the process returns to step S12, where the N + n-th signal is used. N of the first head
The CHG signal is set to “H”. Therefore, the value of n may be positive (+) or negative (-).

In this manner, the flushing operation is performed again in step S13, and it is determined whether the flushing position of the first head is appropriate. If it is determined in step S13 that the flushing position of the first head is appropriate (Yes), the process proceeds to step S15, and the operation of adjusting the flushing position of the second head is started.

In step S15, since t = 0 as described above, the NCHG signal of the second head is set to "H" after Tμsec which is a design reference. Then, in step S16, a flushing operation is performed to determine whether the flushing position of the second head is appropriate. In step S16, the second
If it is determined that the flushing position of the head is appropriate (Yes), the process proceeds to step S18. If it is determined that the flushing position of the second head is not appropriate (No), the value of t is input in step S17. I do.

With respect to the value of t, an appropriate value of t is input based on the result of the flushing performed in step S16 according to the experience and feeling of the adjuster to some extent, the process returns to step S15, and the second time after T + tμsec.
The NCHG signal of the head is set to “H”. Therefore, the value of t may also be positive (+),
It may be negative (-).

Thus, the flushing operation is performed again in step S16, and it is determined whether the flushing position of the second head is appropriate. If it is determined in step S16 that the flushing position of the second head is appropriate (Yes), the process proceeds to step S18, where the values of n and t set in steps S14 and S17 are written to the nonvolatile memory. Then, the input operation of the adjustment amount is completed.

As can be understood from the above description, the values of n and t written in the non-volatile memory take into account the flight time of the ink droplet during the flushing operation. By using this, a highly accurate flushing position can be secured.

FIG. 6 is a block diagram showing a control system for executing appropriate flushing based on the correction value input by the adjustment amount input means. Reference numeral 31 in the figure denotes an adjustment amount input means, which has the function described in FIG. Reference numeral 32 denotes a non-volatile memory which stores the correction values n and t input by the adjustment amount input means 31.

An encoder signal generated based on driving of the carriage by the carriage control means 33 is inputted to the flushing control means 34,
The flashing control means 34 includes a nonvolatile memory 3
The correction values n and t from 2 are supplied. Therefore, in the flushing control means 34, a flushing control signal is generated at a timing corresponding to the value of N + n for the first head, and a flushing control signal is generated at a timing corresponding to the value of T + t for the second head.

The flushing control signal corresponding to the value of N + n is supplied to the head drive means 35, and generates a drive signal for causing the first head 12a to execute flushing. A flushing control signal corresponding to the value of T + t is also supplied to the head drive unit 35 to generate a drive signal for causing the second head 12b to execute flushing.

Thus, the heads 12a and 12b are flushed at the respective timings with respect to the opening of the ink receiving unit 27 while the carriage is running. Therefore, the ink receiving unit 27
Ink droplets caused by flushing from the heads passing immediately before can be reliably collected and discharged to the waste ink tank.

In the above description, the adjustment of the flushing position with respect to the first flushing area 25 close to the home position has been described. However, the adjustment of the position of the second flushing area 26 is performed with the second flushing area 2.
This can be achieved by performing the same operation as described above, with reference to the encoder signal position, which is a reference in design of the device as No. 6, that is, N + xxxx.

In the above description, the correction value for the flushing reference position in one recording head, ie, the first head, is managed by the number of pulses, and the correction value for the other recording head, ie, the flushing reference position in the second head, is calculated. Although the management is performed by the delay time, the correction values for the flushing reference positions of the first and second heads can be both managed by the number of pulses.

Further, the embodiment shows a recording apparatus having two recording heads. However, even in an apparatus having three or more recording heads, each recording head can be formed by the same means as described above. Can be determined.

Further, the above description is based on an example in which the present invention is applied to a particularly large recording apparatus as shown in FIGS. 1 to 3, but the present invention is applied to such a specific recording apparatus. In addition to the above, it is needless to say that the same operation and effect can be obtained by applying the present invention to another ink jet recording apparatus.

[0056]

As is apparent from the above description, the flushing position adjusting device in the ink jet type recording apparatus according to the present invention includes the adjustment amount input means for adjusting the output timing of the flushing control signal given to each recording head. Since the output timing of the flushing control signal for each recording head is determined by using the adjustment value input by the adjustment amount input means, in the running state of each recording head, the flushing area can be accurately determined. Ink droplets can be ejected. Therefore, it is possible to improve the throughput,
Further, since the landing position of the ink droplet in the flushing area can be specified in a narrower area, the width of the flushing area can be further reduced, which can contribute to downsizing of the apparatus.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a front view schematically showing an internal configuration of the recording apparatus shown in FIG.

FIG. 3 is a longitudinal sectional view showing a state in which the flashing region is broken in the recording apparatus shown in FIG. 2;

FIG. 4 is a timing chart for explaining the operation of the flushing position adjusting device according to the present invention.

FIG. 5 is a flowchart showing an adjusting operation of the flushing position adjusting device.

FIG. 6 is a block diagram showing a configuration of the flushing position adjusting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed part 2 Printing part 3 Discharge stack part 4 Roll paper 11 Carriage 12a, 12b Recording head 21 Capping means 22 Suction pump 25, 26 Flushing area 27 Ink receiving unit 31 Adjustment amount input means 32 Non-volatile memory 33 Carriage control means 34 flushing control means 35 head driving means

Claims (7)

[Claims] A plurality of recording heads are mounted on a carriage, and printing is performed while each of the recording heads moves in a direction in which these recording heads are arranged, and ink droplets are flushed to a flushing area in a moving state of the carriage. A flushing position adjusting device for a printing apparatus configured to adjust the output timing of a flushing control signal applied to each of the printheads, the adjustment value being input by the adjustment amount inputting means. A flushing position adjusting device in an ink jet type recording apparatus, wherein the output timing of a flushing control signal to each recording head is determined by utilizing the above. 2. An adjustment value of an output timing of a flushing control signal in each printhead, which is input by the adjustment amount input means, is corrected with respect to a preset reference position corresponding to the flushing area in any one printhead. The flushing position adjusting device according to claim 1, wherein the flushing position adjusting device is configured to be input as a value. 3. A correction value for a preset reference position corresponding to a flushing area in any one of the recording heads is managed by a pulse number, and a correction value for the reference position in another recording head is a delay value. 3. The flushing position adjusting device in the ink jet recording apparatus according to claim 2, wherein the flushing position adjusting device is configured to be managed by time. 4. A correction value for a preset reference position corresponding to a flushing area in any one of the recording heads and a correction value for the reference position in another recording head are respectively managed by the number of pulses. 3. The flushing position adjusting device in the ink jet recording apparatus according to claim 2, wherein 5. A printing apparatus according to claim 2, wherein a preset reference position corresponding to a flushing area in any one of the print heads is obtained by an encoder signal generated as the carriage moves.
A flushing position adjusting device in the ink jet recording apparatus according to any one of the above. 6. The correction value is stored in a non-volatile memory, and an output timing of each flushing control signal is determined based on an encoder signal generated with movement of a carriage and a correction value stored in the memory. The flushing position adjusting device in the ink jet recording apparatus according to claim 5, wherein 7. The ink jet type according to claim 1, wherein a width of the flushing area in the carriage traveling direction is smaller than a width of the plurality of recording heads in the carriage traveling direction. A flushing position adjusting device in a recording device.