JP2007030407A - Printing controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing controller enabling the optimization of a discharge pulse. <P>SOLUTION: A nozzle monitoring group for monitoring separately from a printing nozzle group is established separately, and determines whether every nozzle monitoring group executes a continuous discharge or does not execute the discharge continuously, and then the discharge pulse is optimized according the result. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that has a plurality of print nozzle groups, called print heads, and records an image by ejecting ink from the print nozzle groups, and particularly relates to control of heat pulses applied to the print nozzle groups. Is.

  2. Description of the Related Art In recent years, there are printers as information output devices in word processors, personal computers, facsimiles, and the like, which record information such as desired characters and images on a sheet-like recording medium such as paper or film.

  Various types of printer recording methods are known. One of them is that non-contact recording is possible on recording media such as paper, colorization is easy, and quietness is high. There are inkjet systems with

  This ink jet printer can be equipped with a print head for each color, and ink is ejected to the print head in the main scanning direction (print head moving direction) and in the sub-scanning direction (recording medium transport direction). Printing nozzles are arranged side by side.

  While the print head is reciprocated in the main scanning direction, the movement position is sequentially detected, and a plurality of raster images for the print nozzles are simultaneously recorded by ejecting ink from the print nozzles to the recording medium for each print position. When printing in the desired main scanning direction is finished, the recording medium is moved in the sub-scanning direction (the recording medium is advanced), and the print head is reciprocated in the main scanning direction again to perform the next printing. In general, printing methods that are easy to miniaturize are widely used.

  The conventional description will be given with reference to FIGS.

  FIG. 1 shows an example of a print head of an ink jet printer. In this figure, there are 70 nozzles for discharging ink in one color in total, and it is configured in two rows. In the case of a color ink jet printer, such nozzle aligned heads are prepared for the number of colors.

  In this figure, since the head is composed of 2 nozzles with 35 nozzles for each color and a total of 70 nozzles, if the number of colors is 6, this inkjet printer has 420 nozzles. Printing is performed by ejecting ink from nozzles by applying ejection pulses. In other words, it is necessary to apply energy to up to 420 nozzles simultaneously. In such a system, if the number of nozzles in the head is increased, the energy required simply increases.

  Therefore, by dividing the print head nozzles into several groups and giving sequential discharge pulses to these discharge nozzle groups, there is a method that does not increase the energy consumption per discharge even if the number of nozzles increases. It has been taken. FIG. 2 is a diagram illustrating this, and shows that the discharge of all the nozzle rows is performed with five discharges.

  That is, in the first discharge, discharge pulses are given to 14 nozzles of the nozzles (0, 10, 20, 30, 40, 50, 60, 1, 11, 21, 31, 41, 51, 61). This is called a discharge nozzle group 0. In the second discharge, discharge pulses are given to 14 nozzles of the nozzles (2, 12, 22, 32, 42, 52, 62, 3, 13, 23, 33, 43, 53, 63). This is called discharge nozzle group 1. In the third discharge, a discharge pulse is given to 14 nozzles of the nozzles (4, 14, 24, 34, 44, 54, 64, 5, 15, 25, 35, 45, 55, 65). This is called a discharge nozzle group 2. In the fourth discharge, discharge pulses are given to 14 nozzles (6, 16, 26, 36, 46, 56, 66, 7, 17, 27, 37, 47, 57, 67). This is called a discharge nozzle group 3. In the fifth discharge, a discharge pulse is given to 14 nozzles of the nozzles (8, 18, 28, 38, 48, 58, 68, 9, 19, 29, 39, 49, 59, 69). This is called a discharge nozzle group 4.

  If ink is ejected from the nozzles of each ejection nozzle group and printing is performed by sequentially giving ejection pulses to each of these ejection nozzle groups, the number of nozzles that eject simultaneously is maximum for one head in this example. There are 14 nozzles, and in the case of 6 colors, the maximum number of simultaneous ejection nozzles is 84. In other words, by dividing the nozzles of the head into several groups and sequentially giving ejection pulses to the ejection nozzle groups, even if the number of nozzles is increased, the energy consumed for one ejection does not increase. I'm sorry.

  Also, as shown in FIG. 2, the discharge nozzle group is a group of nozzles at discrete positions with respect to all nozzles. This is to prevent the nozzles that eject ink at a time from being biased toward the physical position of the nozzle row.

  By the way, the energy given to each ejection nozzle group is determined by the active time of the ejection pulse to be given, and the energy must be made equal for each ejection. This is to maintain print quality. If there is a variation in energy applied to each ejection nozzle group, ink ejection is not stable, and the amount of ink ejected is not constant. This indicates that in each discharge nozzle group, the active time of the discharge pulse to be given must be determined depending on which nozzle discharges from which nozzle and does not discharge from which nozzle. For example, in the case of solid printing, ink is discharged from all the nozzles from the first discharge to the fifth discharge, and therefore, the same discharge pulse may be given from the first discharge to the fifth discharge. However, in general, solid printing is not performed so much, for example, the number of nozzles ejected according to the image, such as ejection from only seven nozzles (0, 20, 40, 60, 11, 31, 51) in the first ejection. Will change. Therefore, the active time of the ejection pulse given to each nozzle group is also changed according to the number of nozzles ejected simultaneously.

  FIG. 2 shows a state where all the nozzles eject one time, but in practice, a desired image is formed by moving the print size required in the head moving direction 1. At that time, after the fifth discharge, discharge is performed by the first discharge nozzle, and this is repeated. This ejection for the print size is called one scan.

  Alternatively, at the timing at which the head moves in the direction opposite to the head moving direction 1, similarly, the ejection is started from the fifth ejection, and a desired image is formed by performing this for one scan.

As another conventional example, Patent Literature 1 and Patent Literature 2 can be cited.
JP 2002-211010 A JP 2002-337334 A

  As described above, conventionally, at the timing of ejecting ink, the active time of ejection pulses is determined according to the number of nozzles to be ejected, and an image is formed.

  In order to increase the printing speed, it is effective to shorten the interval between discharges, increase the number of nozzles, and increase the number of nozzles belonging to one nozzle group.

  On the other hand, in order to prevent deterioration in image quality, it is necessary to stably supply ink near the nozzles. However, as the number of nozzles increases, it becomes impossible to stably supply ink near the ink outlets, which may cause deterioration in image quality. ing.

  That is, as the number of nozzles increases, it is necessary to consider the discharge frequency at both ends of the nozzle and the discharge frequency at the center of the nozzle in addition to determining the active time of the discharge pulse according to the number of discharges in the conventional discharge nozzle group unit.

The proposed printing control apparatus intends to solve the above problems by the following. That is,
-Within one scan, separate nozzle monitoring groups at physical positions can be set separately from the nozzle groups for each print unit.

  ・ When this separately set nozzle monitoring group discharges continuously and when it does not discharge continuously, if it is continuous, it counts up the continuous number of times, and when discharge is not performed, Count how long the discharge has not been performed, and if the period when the discharge has not been performed is longer than a certain period, the count value of the continuous number of times the discharge has been performed is cleared and the discharge is continuously performed again. Count the number of times.

  From the above description, the proposed print control device can grasp the status of whether or not continuous printing has been performed for each nozzle monitoring group corresponding to the physical position of the print head separately from the ink ejection nozzle group. Fine discharge pulse control is possible.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Hereinafter, the operation of the present invention will be described with reference to FIG. 3, FIG. 4, and FIG.

  In the figure, reference numeral 100 denotes a dot count unit that counts the number of ejections in the nozzle monitoring group. In this embodiment, counting is performed for three nozzle monitoring groups, and data is generated by a timing signal from the timing control unit 600. The print data sent from the transfer unit is counted for each specific nozzle monitoring group set by the 1100 nozzle monitoring group selection unit.

  This is provided separately from the dot count in the nozzle group in a normally prepared ink discharge unit.

  200 is a continuous count unit. For each nozzle monitoring group, the 100 dot count unit performs an addition operation if the nozzle to be ejected is not '0', and clears the count if '0' is a specific number of times or more. . Such a counting operation is performed for each nozzle monitoring group by a timing signal from the print timing control unit.

  This is also provided separately from the dot count in the nozzle group in a normally prepared ink discharge unit.

  Reference numeral 300 denotes a table reference control unit that determines which part of the correction value of the 400 pulse value correction table is to be referred to from the 100 dot count unit and the 200 continuous count unit.

  Reference numeral 400 denotes a pulse value correction table in which the user sets in advance what kind of correction is to be performed based on the relationship between the number of ejections and continuous ejection.

  500 is a discharge pulse generator, and the user sets a basic discharge pulse in advance, and in addition to that, the correction value from the 400 pulse value correction table is corrected for the set discharge pulse, and 600 printing is performed. An ejection pulse is generated at an appropriate printing timing of the timing controller.

  A timing control unit 600 is a timing control circuit for appropriately performing printing, and controls data read timing from the image memory, image data generation timing, dot count timing, print data transfer timing, and the like.

  Reference numeral 700 denotes a data transfer unit that transfers image data to the head for each nozzle group in accordance with a timing signal from the 600 timing control unit, and also sends image data to be actually ejected to the 100 dot count unit.

  Reference numeral 800 denotes an image data generation unit that performs mask processing according to a printing method.

  An image memory access unit 900 appropriately reads image data to be printed from the 1000 image memory in accordance with a timing signal from the 600 timing control unit.

  An image memory 1000 stores image data to be printed.

  Reference numeral 1100 denotes a nozzle monitoring group selection unit. In this embodiment, apart from the ejection nozzle group for normal printing, as shown in FIG. Set as a group and set as nozzle monitoring group U, set the nozzle (30 to 39) at the center as one nozzle group and set as nozzle monitoring group M, and set the nozzles (60 to 69) at the lower end as one nozzle group The nozzles belonging to the three nozzle monitoring groups are set so as to be set as the nozzle monitoring group D. The dot count for each of the three nozzle monitoring groups is performed by the 100 dot count unit. That is, the nozzle monitoring group U within the 100 dot count of FIG. 3 performs the dot count of the nozzle monitoring group U of FIG. 5, and the nozzle monitoring group M within the 100 dot count of FIG. 3 is the dot count of the nozzle monitoring group M of FIG. The nozzle monitoring group D within the 100 dot count of FIG. 3 performs the dot count of the nozzle monitoring group D of FIG.

  FIG. 4 is a block diagram showing an example of the operation of the 200 continuous counting unit in FIG.

  In the figure, 201 is a discharge presence / absence determination unit that determines whether or not there is a nozzle to actually discharge, and if even one of the nozzle monitoring groups discharges, sends a signal to the 202 continuous discharge counter unit and discharges even one. If not, a signal is sent to the 203 discontinuous discharge counter.

  Reference numeral 202 denotes a continuous discharge counter unit, which counts up an internal counter based on a signal from a nozzle discharged by a 201 discharge presence / absence determination unit.

  203 is a discontinuous discharge counter unit, and the internal counter is counted up by a signal from the nozzle discharged by the 201 discharge presence / absence determination unit, but when there is one discharge nozzle from the 201 discharge presence / absence determination unit, This counter is cleared.

  A discontinuous discharge counter value determination unit 204 outputs a counter value clear signal to the 202 continuous discharge counter unit when a predetermined count value, for example, a discontinuous discharge count value of 10 times is reached.

  In the above configuration, if there is even one discharge in each nozzle monitoring group, it is counted up, and when there is no discharge for a certain period, the counter is cleared, and the case where the continuous discharge is not performed more than a certain number of times. Except for the past continuous discharge state, it is possible to detect.

  FIG. 6 shows an example of another embodiment of the present invention. By adopting a configuration in which the determination reference count number in the discontinuous state can be arbitrarily set, it is possible to cope with more flexibility.

FIG. 4 is a diagram illustrating an example of an arrangement of print nozzles prepared in a print head for one color of a print control apparatus. FIG. 4 is a diagram for explaining an example of a discharge state of a print nozzle prepared in a one-color print head of a print control apparatus. FIG. 3 is a block diagram for explaining a characteristic operation of the printing control apparatus. FIG. 3 is a block diagram for explaining a characteristic operation of discharge count of the print control apparatus. FIG. 5 is a block diagram for explaining a second characteristic ejection counting operation of the printing control apparatus. The figure which shows an example of another Example of this plan.

Explanation of symbols

100 dot count section
200 continuous count section
300 Table reference controller
400 Pulse value correction table
500 Discharge pulse generator
600 Print timing controller
700 Data transfer section
800 Image data generator
900 Image memory access block
1000 image memory
201 Discharge presence / absence judgment unit
202 Continuous discharge counter
203 Discontinuous discharge counter
204 Discontinuous discharge counter value determination unit
205 Discontinuous discharge counter value setting section

Claims (3)

The print head has a plurality of print nozzles that eject ink, and the print nozzles are ejected simultaneously, grouped into several nozzle blocks, and a heat pulse signal is given to each nozzle block to eject ink. In the ink jet printing control apparatus, the heat pulse signal stabilizes ink ejection by changing the active time according to the number of nozzles ejected.
In addition to the nozzle block at the time of printing, a nozzle monitoring block for monitoring the discharge state of the print nozzle can be set. The nozzle monitoring block counts the continuous discharge of ink, and the continuous discharge count value and the discharge from this A print control apparatus characterized in that an active time of a heat pulse is determined from the number of simultaneous discharges to be attempted.   When counting that the nozzle monitoring block has continuously ejected ink, if there is no ink ejection, it counts the state without ink ejection, and when this no-ink ejection count value reaches the predetermined number, continuous ejection The print control apparatus according to claim 1, wherein the continuity of ink ejection is counted by clearing the count value.   3. The print control apparatus according to claim 1, wherein the continuous discharge is counted as continuous discharge when a predetermined number or more of the print nozzles in the nozzle monitoring group discharge.

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