JPS63153151A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To easily and accurately correct a recording position, by providing a test pattern signal generating means for forming a test pattern confirming the coincidence of the positions of ink droplets on a recording medium in a reciprocating operation direction. CONSTITUTION:MPU 11 records a test pattern 1 by the signal of starting the test pattern 1 from a key switch 17. For example, the test pattern 1 records the longitudinal lines in P-and Q-directions by the reciprocating recording only due to a cyan recording bead 5A. When the longitudinal lines are shifted, a dip switch 14a is changed over to repeat the formation of test patterns until the longitudinal lines coincide. The delay time Z at the time of forward recording is determined. Next, MPU 11 records a test pattern II and the longitudinal lines of recording heads g 5A-5D are recorded at a one-line unit by the recording in the P-direction. When there is shift between colors, dip switches 14B, 14C, 14D are changed over and the formation of test patterns is repeated until all of longitudinal lines coincide with each other. The delay times DB, DC, DD to the recording heads 5A-5D are determined and the recording position is corrected simply and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inkjet recording apparatus in which a recording head is mounted on a carriage.

[Prior art]

An inkjet recording device forms flying ink droplets and prints them onto a sheet (recording medium) by driving a recording head having multiple ink ejection ports based on data signals.
Inkjet recording devices are also capable of color printing;
For color printing, for example, four recording heads are used corresponding to each ink color of cyan, yellow, magenta, and black. Further, a plurality of recording heads may be provided to correspond to a plurality of inks having different shading even if they have the same hue.

The present invention mounts a recording head on a reciprocating carriage,
The target is an inkjet printing apparatus that scans and prints on a printing medium (paper or a sheet such as a thin plastic plate) with a printing head.

FIG. 2 schematically shows the recording operation of this type of inkjet recording apparatus.

In front of the platen 2 that banks up the recording medium 1, there is a
A guide rail 3 is installed parallel to this, and a plurality of (four in the illustrated example) recording heads 5A, 5B, and 5C15D are mounted on a carriage 4 that is guided and supported by the guide rail and moves back and forth. These recording heads are for example cyan,
It supports yellow, magenta, and black ink colors.

The recording heads 5A to 5D are arranged at predetermined intervals along the recording direction (the direction of arrow P and arrow Q).

During printing, the carriage 4 first moves in the direction of the arrow P, and when it moves to the printing start position detected by the linear encoder 6 as shown in FIG. Squirt out drops.

After that, the carriage 4 is further moved in the P direction, and when the linear encoder 6 detects that the next recording head 5B has reached the recording start position as shown in FIG. 2(B), the recording head 5B is moved. Drive to eject ink droplets. At this time,
The point recorded by the recording head 5B is the recording head 5A.
It is required that the points recorded by the above match on the recording medium 1.

However, using only the timing from the linear encoder 6, it is difficult to align ink droplets ejected from the plurality of print heads 5A to 5D on the print medium l because there is a positional error in the mounting of the print heads 5A to 5D. It was difficult.

Furthermore, during reciprocating printing, when the carriage 4 moves in the direction of arrow P and when it moves in the direction of arrow Q (opposite direction) as shown in FIG. Even if the ink droplets are ejected from 5A),
Due to differences in the flight time of ink droplets and the driving cycle of the recording head, it was difficult to match the recording position between the forward and return times. One timer is provided for each timer, and linear encoder 6 is installed.
By delaying the time from the recording start timing of 1 to the start of driving of the recording heads, the plurality of recording heads 5A to
A method has been proposed in which ink droplets ejected from a 5D or ink droplets ejected from the same print head during reciprocating printing are made to coincide on the print medium 1.

However, in such a conventional configuration, the delay time by the timer of each of the plurality of recording heads must be set individually for both forward and return times, and the dip used for timer setting must be set individually. There have been problems in that the number of switches has increased and the structure has been complicated.

In addition, two correction operations, ie, setting the delay time for the previous time and setting the delay time for the return time, must be performed for each of the recording heads 58 to 5D one by one, which requires a great deal of effort and effort to set the delay time. There was a problem that it took a while.

〔the purpose〕

SUMMARY OF THE INVENTION An object of the present invention is to provide an inkjet recording apparatus that can solve the problems of the prior art, minimize the number of switches for recording position correction, and easily and accurately perform recording position correction.

〔overview〕

The present invention provides a test pattern signal generating means for forming a test pattern for confirming alignment of ink droplets on a recording medium in a reciprocating direction in an inkjet recording apparatus having a recording head mounted on a reciprocating carriage. The above object is achieved by the configuration in which the above object is provided.

〔Example〕

The present invention will be specifically described below with reference to FIGS. 1, 3, and 4.

FIG. 1 is a block diagram schematically showing the configuration of an inkjet recording apparatus according to the present invention.

Reference numeral 11 denotes a microprocessor unit (MPU) that controls the operation of the entire recording apparatus, and records data (print data) is sent to each recording head 5A to 5D in advance via a data bus 12.
is sent.

Reference numeral 13 is a timer for correcting the round trip delay time.

The MPU II sets the counter of the timer 13 according to the value read from the dip switch 14A, and the timer 13 starts to be activated according to the timing signal from the linear encoder 6.

The MPU II has timers 15A to 15B and 15C for recording position correction corresponding to each of the recording heads 5A to 5D.
115D is connected.

When the time preset by the MPU II is counted by the timer 13 for correcting the round trip delay time, the timer 13 outputs a timeout signal to each of the timers 15A to 15D for correcting the recording position.

Among these timers 15A to 15D for recording position correction, a fixed value is set in the counter of the timer 15A, and a value determined by the data read out in advance by the MPU II from the dip switches 14B and 14C14D in the counters of the other timers 15B to 15D. There are cents.

In addition, the timers 15A to 15D for each recording position correction are
Activation is started by inputting a timeout signal of a timer 13 for round-trip delay time correction, and when a preset time has been counted, each timeout signal is output to the corresponding recording nodes 5A to 5D.

When each of the recording heads 5A to 5D receives a timeout signal from the corresponding timer 15A to 15D,
It is driven based on recording data set in advance by MP[Jll to perform recording.

Further, a key switch 17 is connected to the MPUI 1 to start recording a test pattern for checking the degree of coincidence of recording positions of ink droplets, and when the key switch 17 is operated, recording of a predetermined test pattern is started. signals are input to the MPU II.

FIG. 3 illustrates values set in the counters of timers 15A-15D of each recording head 5A-5D of the inkjet recording apparatus according to the present invention and ink droplet ejection timing.

First, FIG. 3(A) schematically shows the delay time for correcting the recording position of ink droplets ejected from the nozzles 5A to 5D to each recording.

In FIG. 3(A), the intervals of recording start positions sequentially output by the linear encoder 6 (FIG. 1) are constant if the carriage 4 (FIG. 1) moves at a constant speed. The interval when moving in the direction of arrow P is shown as the time interval of 500 μsec between H+1 and n.

This interval of 500 μsec is equal to the drive cycle of the recording head.

Symbol F indicates the flight time from when the ink tN is ejected from the recording head until it reaches the recording medium 1, and in FIG. 3(A), this flight time F is set to 200 μsec, which is almost the same for each of the recording heads 5A to 5D. has been done.

Furthermore, the symbols DASDB, DC, and DD represent each recording head 5.
It is the delay time set in the timers 15A to 15D of A to 5D, excluding DA<DB, DClDD is MPLIII
is determined by the values read from the depth inches 1.4B, 14B, and 14D.

By the way, in reality, the positional error when attaching the grooves 5A to 5D to each recording is ±250 μ2 with respect to the recording head 5A.
It is possible to suppress it by 50μ.

Therefore, when the recording throats 5A to 5D move to the recording start position, the deviation between the actual position of each recording head and the reference position is determined between dotted line a and dotted line d in FIG. 3(A), that is, the reference position. It can be suppressed within the range of +200 μsec of n. In the illustrated example, the MPU II is the recording head 5A to 5D.
Considering that the time for data transfer is about 100 μsec, the range between the dotted line a and the dotted line is set to +200 μsec, which is smaller than +250 μsec.

By the way, if the actual position when the recording throats 5A to 5D move to the recording start position is outside the range of dotted line a and dotted line S, the limit value of +200 μsec or -200 μsec.
Suppose it is μ seconds.

Therefore, the delay time DA of any one recording head 5A
If the time is fixed to 200 μsec, other recording heads 5B to 5D
The delay time DB-DD can be set between 0 and 4008 seconds, and recording can be performed at the same position on the recording medium 1.

FIG. 3(B) shows a delay time when, in addition to the recording position correction shown in FIG. 3(A), forward and backward position corrections are performed during reciprocating recording.

In order to correct the position of this round-trip recording, the timer 13 (
A delay time Z according to FIG. 1) is provided.

The reason for providing this delay time Z is that, assuming that the signal from the encoder 6 is output at the same position during reciprocating, if the recording start position in the past is n (Fig. 3), the recording start position in the return trip is This is because it must be set to n+2.

In other words, the flight time of the ink droplets is about 200 μs,
As mentioned above (the drive cycle of the recording heads 5A to 5D is set to 500
Set the delay time to about μ seconds and set the range of delay time DB to DD to θ to 40
This is because if the time is set to about 0 μsec, the recording start position upon returning must be set at position n+2.

For example, if a delay time of 500 μs or more is required for correcting the recording position during return, such as the recording head 5C in FIG. 3, this delay time will exceed the drive cycle of the recording head 5C. Therefore, unless the aforementioned delay time Z is added, recording becomes impossible.

Therefore, a timer 13 is provided to correct the round trip delay time, and in the past, the delay time Z is set to 0, and when returning, it is set to an appropriate time (
In the illustrated example, if 200 μsec) is set, the counters of timers 15B to 15D for recording position correction at the time of return are set to 400 μsec-DB, 400 μsec-DC, and 400 μsec-, respectively.
By setting the DD, it is possible to always make ink droplets ejected from each of the recording heads 5A to 5D adhere to the same position on the recording medium l even during reciprocating recording.

In order to control delay time correction during such round-trip recording,
The value of the set delay time Z at the time of returning is read from the dip switch 14A, and
114D is configured to successively output values corresponding to the delay times DB%DC and DD of the recording heads 5B to 5D, respectively.

FIG. 4 illustrates a test pattern for checking whether there is any deviation in the recording position (adhering position) of ink droplets in the present invention. That is, FIG. 4(A) shows a test pattern I used for correcting the recording position of the same recording head during reciprocating recording, and FIG.
A test pattern (■) used for correcting the recording position between D and D is shown.

In FIG. 1, when the MPU II receives the start signal of test pattern I from the key switch 17, the MPU
II records a test pattern (2) as shown in FIG. 4(A).

This test pattern (2) is formed by printing vertical lines as shown in the figure by reciprocating printing using only one printing head (in the example shown, the printing head 5A whose ink color is cyan). That is, a vertical line with a height of one line is recorded in the direction of arrow P (forward direction), and then a vertical line with a height of one line is recorded in the direction of arrow Q (return direction).

If there is a deviation in the vertical lines during the reciprocating recording, the dip switch 14A is switched and the operations consisting of adjustment and test pattern formation are repeated until the vertical lines match in the reciprocal recording.

As a result, the delay time Z when returning (when recording in the arrow Q direction)
(Figure 3) is determined.

Next, when the MPUI receives the start signal of the test pattern ① from the key switch 17 (Fig. 1), the MPUI
I records a test pattern (2) as shown in FIG. 4(B).

That is, by recording in one direction (in the direction of arrow P), the vertical lines of each of the rads 5A to 5D, that is, the vertical lines of cyan, magenta, yellow, and black, are printed 1 as shown in the figure.
Record line by line.

However, if there is a discrepancy between each color based on cyan (recording head 5A), the depth inches 14B, 14
The operation consisting of adjustment and test pattern formation is repeated by switching C114D respectively until all vertical lines match.

Through this operation, the delay times DB, DC, and DD for each recording head 5A to 5D are determined.

Therefore, by recording two types of test patterns ■ and ■ as shown in FIG. 4(A) and FIG. 4(B), it became possible to easily and reliably correct the recording position. .

According to the embodiments of the present invention described above with reference to FIGS. 1, 3, and 4, ink droplets ejected from the plurality of recording heads 58 to 5D are aligned on the recording medium 1. In addition to providing correction timers 15A to 15D, a correction timer 13 for matching the positions of ink droplets ejected during reciprocating is provided, and since these timers are operated in combination, the dip switch 14A used for timer setting is provided. The number of switches such as ~14D can be minimized, and the delay time between recording heads 5A to 5D and during reciprocating recording can be corrected with a simple structure, and recording positions can be matched easily and accurately. It became possible to do so.

Also, the delay time setting during reciprocating can be set for each recording head 5A to 5D.
There is no need to operate each time, a common timer 1
3 allows for automatic settings, making correction operations extremely easy.

Furthermore, by operating the key switch 17, a test pattern I for detecting the deviation of the adhesion position of ink droplets during reciprocating printing with the same printhead, and a test pattern I for detecting the deviation of the adhesion position of ink droplets between each of the printheads 5A to 5D during unidirectional printing. Since the test pattern (2) for detecting deviations can be easily recorded, it has become possible to easily and reliably perform correction operations for the recording positions of each of the recording heads 5A to 5D.

Note that in the illustrated configuration, the recording start timing signal is generated using the linear encoder 6;
The signal can also be generated based on the excitation phase switching timing of the pulse motor used to drive the motor.

In addition, the delay time Z for position correction of reciprocating recording and the delay time DB-DD of each recording head 5B to 5D were set using the dilab switches 14A to 14D, which determine the value to be set on the timer counter. Any switch that can be used can be used.

Furthermore, the number of recording heads is not limited to four, and any number can be selected.

(Effects) As is clear from the above description, according to the present invention, a test pattern signal generating means for forming a test pattern for confirming the coincidence of the positions of ink droplets in the reciprocating direction on the recording medium is provided. An inkjet recording apparatus is provided that can minimize the number of setting switches used for recording position correction and can easily correct the recording position.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a control system of an inkjet recording apparatus according to an embodiment of the present invention, and (A) to (C) in FIG.
(A) and (A) of FIG.
B) is a timing chart illustrating the recording position correction for each recording head and the recording position correction during reciprocating recording by the control system in Fig. 1, and (A) and (B) in Fig. 4 respectively show the same recording during reciprocating recording. Test pattern for detecting a deviation in the recording position of the head■ and a test pattern for detecting a deviation in the recording position between multiple recording heads during unidirectional recording■
FIG. 1------1...-Recording medium, 4...--
... Carriage, 5A to 5D ... Recording head, 13 ... Correction timer (reciprocating recording position),
15A-15D...-Correction timer (recording position between recording heads), 17...-Key switch. Agent Patent Attorney Yasushi Ooto Tsumai −

Claims (1)

[Claims] (1) In an inkjet recording apparatus having a recording head mounted on a reciprocating carriage, a test pattern signal generating means is provided for forming a test pattern for confirming the coincidence of the positions of ink droplets on a recording medium in the reciprocating direction. An inkjet recording device comprising: