JP2008087326A - Inkjet recording device and its recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make density differences on a printed image inconspicuous and reduce a memory capacity even if recording head driving conditions change when a recording device using a bubble-jet (R) recording head performs continuous printing. <P>SOLUTION: The inkjet recording device has a driving condition storage means 14 to store driving conditions of a recording head 8 which are supplied to the recording head 8 and by which heating elements are driven, and a temperature detection means 11 to detect the temperature of the recording head 8. The recording device has a printing duty judgment means 12 to judge a printing duty in a scanning direction, and a mixture means to mix a plurality of driving conditions stored in the driving condition storage means during one scan recording. Furthermore, the recording device has a changing means to change the mixture ratio of the driving conditions in the one scan recording in accordance with the detected temperature of the recording head 8 and the judged printing duty. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an ink jet recording apparatus that records a recording liquid (hereinafter simply referred to as “ink”) by ejecting it from an ink ejection port as flying droplets and adhering it to a recording material, and a control method therefor.

  Conventionally, ink in an ink discharge port and a liquid channel communicating with the ink discharge port (hereinafter referred to as “nozzle” together) is heated by a heating element such as a heater to generate bubbles. Micro ink droplets are ejected from the ejection port onto the recording medium. Thus, a so-called bubble jet (registered trademark) recording head for obtaining a recorded image on the recording medium is widely known and applied to printers, copiers, and the like.

  In the recording apparatus using the bubble jet (registered trademark) recording head, the heat is generated by the heating element to heat the ink. Therefore, when printing is performed continuously, heat is accumulated in the recording head and the temperature of the recording head rises. . In general, since the viscosity of ink changes with temperature, the viscosity of the ink changes due to the temperature rise of the recording head or the change of the environmental temperature, and the ejection amount of the ejected ink droplets changes. Changes.

  In addition, in the recording with such a bubble jet (registered trademark) recording head, it is easy to increase the number of nozzles and the density of the nozzles, which is suitable for high speed and high image quality. In particular, many attempts have been made to improve the recording speed of printers, copiers, and the like by increasing the number of nozzles and increasing the drive frequency of the recording head. The change in print density due to the temperature rise of the recording head is an increasingly important issue.

  In addition, when the support member that supports the recording head provided with the heat generating element is configured with a resin member, the heat generated in the recording head compared to the case where a member having a large heat capacity such as alumina is configured as the support member, It is difficult for the supporting member to escape and the temperature of the recording head itself tends to rise. Therefore, a change in print density due to temperature rise of the recording head is a big problem.

  Therefore, in a conventional ink jet recording apparatus, a temperature detecting element such as a thermistor is used to detect the temperature of the recording head, and the density is adjusted by changing the driving condition of the recording head based on the detected temperature. (For example, refer to Patent Document 1). That is, in the invention described in Patent Document 1, the temperature of the recording head is detected, and the driving condition of the recording head is controlled based on the detected temperature of the recording head.

  In the conventional control method described above, for example, if the drive pulse generation condition according to the detected temperature of the recording head is changed for each page, the density may differ between the first and last pages.

  Further, when one page is divided into a plurality of areas and the print head driving conditions are set for each of the divided areas, a density difference may appear between scans.

  FIG. 14 is an enlarged schematic diagram illustrating an example of a print image when the driving condition is changed in a conventional inkjet recording apparatus.

  In the serial printer, as described above, when the driving condition of the recording head is changed in the continuous print image in accordance with the detected temperature of the recording head, the density difference becomes conspicuous. In the example shown in FIG. 14, when one page is divided into a plurality of areas and printed, a heating element is driven by a so-called “double pulse driving condition α” in which a recording of a certain scan is driven in combination with a prepulse and a main pulse, for example. Drive to print.

  The “pre-pulse” is a pulse for warming ink, and the “main pulse” is a pulse for ejecting ink.

  Then, as a result of detecting the temperature condition or the like before printing of the next scan, printing of the next scan was performed by driving the heating element according to the so-called “single pulse driving condition β” that is driven only by the main pulse, for example. Shows the case.

  Thus, the upper and lower two scans shown in FIG. 14 are driven under different driving conditions. At this time, the portion printed with the driving condition α driven by the main pulse while the ink is warmed by the prepulse has a larger amount of ink droplets than the portion printed by the driving condition β driven only by the main pulse. Become. That is, when ink is ejected after warming the ink with a pre-pulse, the amount of ink droplets increases. Therefore, the diameter of the recorded dots is relatively larger in the upper half and smaller in the lower half.

  FIG. 15 is a diagram illustrating the relationship between the head temperature and the ejection amount when driven under the driving condition α and the driving condition β.

  As shown in FIG. 15, when the driving condition α and the driving condition β are suddenly switched, the discharge amount at the same head temperature is greatly different, and a density difference appears between the two scans.

  Further, if the driving conditions are finely controlled, the density difference between the scans can be reduced. However, there is a problem that the cost is increased because a large capacity of a memory for storing each driving condition is required and a large capacity of a memory for storing data for determining each driving condition is required.

  Furthermore, even if it is attempted to finely control the driving conditions, there is a problem that it is difficult to adjust the ink ejection amount to a minute amount because there is a limit to the minimum time width that can adjust the time of the pulse width for driving the heating element.

  On the other hand, when changing the drive condition between scans, it is known to control by mixing the drive condition driven in the previous scan and the drive condition driven in the next scan (for example, Patent Document 2). reference).

In the method described in Patent Document 2, for example, in the previous scan, the drive is performed under the double pulse drive condition α, and after the temperature rises, the double pulse drive condition α and the single pulse drive condition β are mixed in the next scan. To drive.
JP-A-3-284951 Japanese Patent Laid-Open No. 10-157136

  However, in the method described in Patent Document 2, when the drive is changed to the single pulse drive condition β in the next scan, the print duty after the change of the drive condition is low, so the temperature of the recording head may not increase so much. As described above, when the drive condition is changed and printing is performed under the single pulse drive condition β, there is a problem that the discharge amount is small, the density difference is generated, and the density difference appears.

In the recording apparatus using the Bubble Jet (registered trademark) recording head, the present invention prevents the density difference on the printed image from conspicuous even if the recording head driving condition changes, when printing is performed continuously. The purpose is to reduce the memory capacity.

The present invention includes drive condition storage means for storing a drive condition of a print head that is supplied to the print head and drives the heating element, and temperature detection means for detecting the temperature of the print head. In addition, the present invention includes a print duty determination unit that determines a print duty in the scanning direction, and a mixing unit that mixes a plurality of drive conditions stored in the drive condition storage unit during one scan recording. Furthermore, the present invention includes a changing unit that changes a mixing ratio of the plurality of driving conditions during the one-scan recording according to the detected temperature of the recording head and the determined printing duty.

According to the present invention, in a recording apparatus using a Bubble Jet (registered trademark) recording head, when printing is performed continuously, the density difference on the printed image is not noticeable even if the driving conditions of the recording head change. In addition, the memory capacity can be reduced.

  FIG. 1 is a diagram illustrating a configuration of a control circuit of an ink jet recording apparatus 100 according to an embodiment of the present invention.

  The ink jet recording apparatus 100 includes a system controller 1, a host computer 4, a buffer 5, a frame buffer memory 6, a recording control unit 7, a recording head 8, a recording element 9, and a temperature detection unit 11.

  The system controller 1 controls the entire apparatus and functions as a CPU, and also includes a ROM 2 that stores a control program and a RAM 3 that is used during processing operations related to control.

  The buffer 5 temporarily stores data and information related to recording from the host computer 4 and temporarily stores the information until the information is read on the system controller 1 side.

  The frame buffer memory 6 develops data relating to recording read into the system controller 1 into image data. Therefore, the frame buffer memory 6 has a memory size required for recording.

  The recording control unit 7 controls the recording head 8 in accordance with a command from the system controller 1 and controls the recording head 8 according to the ink ejection speed, the number of recording data, and the like, and is provided in the recording head 8 for ink ejection. The drive condition of the recording head being determined is determined. The recording control unit 7 includes a printing duty counter 12, a drive condition setting circuit 13, and a drive condition storage ROM 14.

  The recording element 9 temporarily stores the data to be recorded every time recording is performed, and the storage capacity of the storage element varies depending on the number of nozzles of the recording head 8.

  A driver (not shown) is provided in the recording head 8, and this driver drives the recording head 8 in accordance with a control signal from the recording control unit 7.

  FIG. 2 is a diagram illustrating an example of a driving pulse for driving the recording head 8.

  In this example, the heating element is driven once with two drive pulses. The “driving condition A” is a condition in which a pre-pulse, which is a pulse for heating ink, and a main pulse, which is a pulse for actually ejecting ink, are applied to a heating element, and ink is ejected. Double pulse ".

  The “driving condition B” is a condition in which a single main pulse is applied to the heat generating element and ink is ejected, and is a so-called “single pulse”.

  The temperature detection unit 11 detects the temperature of the recording head 8. In the recording control unit 7, the printing duty counter 12 counts the average printing duty stored in the recording element 9.

  The driving condition setting circuit 13 sets driving conditions. The driving condition storage ROM 14 is a driving condition storage ROM that stores pulse table data in which the temperature of the recording head 8 and the driving conditions of the recording head 8 are associated with each other.

  The drive condition setting circuit 13 takes out the drive conditions from the drive condition storage ROM 14 in which the pulse table data is stored, sets the mixing ratio of a plurality of drive conditions as necessary, and controls to print.

  The pulse table data in which the driving conditions of the recording head 8 are associated with the temperature of the recording head 8 detected by the temperature detecting means 11 that detects the temperature of the recording head 8 and the average print duty is the driving condition. It is stored in the storage ROM 14. The “average print duty” is a print duty counted by the print duty counter 12 and is an average print duty of image data printed in the next scan.

  By such control, even when the driving condition is changed according to the temperature rise of the recording head 8, the density difference caused by the change in the ejection amount of the ejected ink droplets can be reduced.

  Next, an example of the control method will be described.

  FIG. 3 is a diagram for explaining an example of the contents stored in the drive condition storage ROM 14.

  The example shown in FIG. 3 is an example in which the widths of the pre-pulse, the interval, and the main pulse are stored in accordance with the temperature of the recording head 8.

  In this example, if the head temperature is less than 30 ° C., driving is performed under the driving condition A (double pulse), and if the head temperature is 40 ° C. or higher, driving is performed under the driving condition B (single pulse). If the head temperature is 30 ° C. or higher and lower than 40 ° C., printing is performed while changing the mixing ratio of the driving condition A and the driving condition B. Corresponding to the average print duty of the image data printed in the next scan (average print duty counted by the counter 12), the mixing ratio of the drive condition A and the drive condition B is changed and printing is performed.

  FIG. 4 is a diagram illustrating an example in which the mixing ratio of the driving condition A and the driving condition B is changed during one scan in accordance with the head temperature and the average print duty.

  If the ratio of drive condition A / (drive condition A + drive condition B) per scan is changed and set as shown in FIG. 4, the drive condition is finely controlled without storing a lot of pulse table data. can do.

  Next, the change in the discharge amount when the drive is controlled as described above will be described.

  FIG. 5 is a diagram illustrating the relationship between the ink discharge amount and the head temperature when driving is performed under the driving condition A and the driving condition B.

  As shown in FIG. 5, the discharge amount when discharged under the drive condition A is larger than the discharge amount when discharged under the drive condition B. Therefore, the driving is performed under the driving condition A up to 30 ° C., and the driving condition A and the driving condition B are used at 30 ° C. to 40 ° C., and the mixing ratio is changed as shown in FIG. If it becomes higher, the driving is performed under the driving condition B. As a result, even if the head temperature changes, the ink discharge amount is appropriately adjusted, and the density difference can be eliminated.

  In the above embodiment, the driving condition A is a double pulse and the driving condition B is a single pulse, but instead of doing this, both the driving condition A and the driving condition B may be double pulses. In this case, the duty in the driving condition A and the duty in the driving condition B are made different. Further, both the driving condition A and the driving condition B may be a single pulse. In this case, the duty in the driving condition A and the duty in the driving condition B are made different.

  FIG. 6 shows an example in which the mixing ratio between the driving condition A and the driving condition B is changed during one scan in accordance with the head temperature and the average printing duty, and the driving condition B and driving condition C per scan. It is a figure which shows the example which changes the mixing ratio of 1 in 1 scan.

  Further, as shown in FIG. 6, the driving condition storage ROM 14 may store three driving conditions, and the driving conditions may be changed according to the temperature and the print duty.

Next, an example in which recording is performed by the above control method will be described.

  FIG. 7 is an explanatory diagram of the first embodiment of the present invention. The recording head 8 repeats recording by reciprocation in the scanning direction, and the printing pattern when the recording is performed with “1 pass” and with a printing duty of 100% is shown. It is explanatory drawing.

  The “one pass” means that after the recording in the scanning in one scanning direction, the recording in the next scanning is performed so that the recording in the previous scanning and the printed dots do not overlap.

  In the first embodiment, in order to simplify the explanation, it is assumed that the bandwidth that the recording head 8 prints in one scan is 8 dots. However, in actuality, a larger number of dots may be recorded. Many.

  Assume that the head temperature before scanning is 27 ° C., and at this time, the upper recording of the three scanning recordings shown in FIG. 7 (mixing of driving condition A and driving condition AB, recording based on driving condition B). (Recording under driving condition A). In this case, since the driving is performed under the driving condition A having a relatively large calorific value, the ejection amount to be ejected is large, the printed dot diameter is increased, and the printing density is increased.

  When the head temperature reaches 35 ° C., when recording in the middle of the three scan recordings (recording by mixing the driving conditions AB), the temperature of the recording head 8 rises. In order to cancel, it is assumed that the driving condition B changes to a relatively small calorific value.

  In the first embodiment, the printing is performed by mixing the driving condition A and the driving condition B, and the head temperature before scanning is 35 ° C., and recording is performed at a printing duty of 100%. As shown in FIG. Driving is performed at a mixing ratio of A and driving condition B of 50%.

  In the first embodiment, 8 dots in the scanning direction and the vertical direction ejected at substantially the same timing are driven under the same driving condition, and the driving condition A and the driving condition B are set during one scan recording. The mixing ratio is 50%. In this way, driving is performed by switching the driving conditions of 8 dots in the scanning direction and the vertical direction.

  Further, as shown in FIG. 7, the method of switching between the driving condition A and the driving condition B takes into account that the recording head 8 gradually increases in temperature, and gradually reduces the ratio of the driving condition A. It is desirable to switch as follows. However, the switching between the driving condition A and the driving condition B may be performed uniformly during the recording of one scan.

  When the head temperature before scanning reaches 42 ° C., the lower recording (recording under the driving condition B) of the three scanning recordings is performed.

  By adopting the recording method as described above, as shown in FIG. 5, even if the head temperature changes, the drive conditions are changed, so that the ink ejection amount is adjusted appropriately. In other words, even if the drive pulse control in the drive circuit is not precise, and even if the memory capacity for storing the drive conditions is small, the density difference is eliminated and the ink ejection amount is adjusted appropriately. Can do.

  FIG. 8 is an explanatory diagram of a print pattern when recording is performed with an average print duty of 50% in one pass.

  The example shown in FIG. 8 is recording of four scans (mixing of driving condition A, first driving condition AB, mixing of second driving condition AB, recording based on driving condition B).

  Assume that the head temperature before scanning is 27 ° C. At this time, the first-stage recording (recording under the driving condition A) is performed among the recordings of the four scans. In this case, the driving is performed under the driving condition A having a relatively large calorific value.

  When the head temperature before scanning reaches 32 ° C., the second-stage recording (recording by mixing the first driving condition AB) is performed among the recordings of the four scans. In this case, recording is performed with the print duty set to 50%, and as shown in FIG. 4, driving is performed with the mixing ratio of the drive condition A and the drive condition B set to 80%.

  When the head temperature before scanning reaches 36 ° C., the third-stage recording (recording by mixing the second driving condition AB) is executed. In this case, the driving is performed with the mixing ratio of the driving condition A and the driving condition B set to 30%. Here, when switching to the mixing of the driving conditions AB of the second stage and the third stage, the driving condition A is gradually increased in consideration of the gradual increase in temperature of the recording head 8 as in the first embodiment. It is desirable to switch so as to reduce the ratio.

  Then, when the head temperature before scanning reaches 41 ° C., printing at the third stage is executed and driving is performed under driving condition B.

  As described above, when the print duty is different, by detecting the print duty, the head temperature before scanning in the next scan can be predicted, and control according to the situation at that time can be performed. As in the case of printing with the print duty set to 100%, by changing the drive conditions, the discharge amount can be adjusted and the density difference can be eliminated.

  FIG. 9 is a diagram illustrating five scan recordings including a scan recording in which the drive condition changes when 100% recording is performed in one pass, as in FIG. 7.

The example shown in FIG. 9 is an example in which recording is performed with the recording head 8 which is more difficult to raise the temperature than the recording head 8 used in the recording of FIG. Then, as shown in FIG. 9, if the head temperature before scanning in the middle number of scans is a temperature driven by mixing of driving conditions AB, according to the head temperature before scanning of the scan and the print duty, The driving condition AB may be mixed.

  FIG. 10 is an explanatory diagram of a print pattern according to the second embodiment of the present invention. Similarly to the first embodiment, FIG. 10 is an explanatory diagram of a print pattern when printing with a print duty of 100% is performed in one pass.

  Here, in the second embodiment, as in the first embodiment, the driving in the upper stage and the lower stage is executed under the driving condition A and the driving condition B, respectively. When driving under the middle driving conditions (mixing of driving conditions AB), the scanning direction and the vertical direction are set so that the mixing ratio of the driving conditions A and the driving conditions B is 50% during one scan recording. These 8 dots are driven by switching their driving conditions. In this case, each dot or a group of dots grouped in a certain combination is driven by different drive signals, thus forming a circuit on the substrate.

According to the second embodiment, similarly to the first embodiment, the discharge amount can be adjusted by changing the driving condition, and the density difference can be eliminated. As shown in FIG. 10, also in the second embodiment, the driving condition A and the driving condition B are switched step by step in consideration of the gradual increase in temperature of the recording head 8. It is desirable to switch so that the ratio of condition A is reduced.

  FIG. 11 is an explanatory diagram of a print pattern according to the third embodiment of the present invention. Similarly to the first and second embodiments, FIG. 11 is an explanatory diagram of a print pattern when recording is performed with a print duty of 100% in one pass.

  In the third embodiment, similarly to the first and second embodiments, the driving in the upper stage and the lower stage is performed under the driving condition A and the driving condition B, respectively. When driving under middle driving conditions (mixing of driving conditions AB), each dot is different so that the mixing ratio of driving conditions A and driving conditions B is 50% during one scan recording. Print under driving conditions. In addition, the dots in the scanning direction and the vertical direction that are ejected at substantially the same timing are also driven by changing the driving conditions.

According to the third embodiment, similarly to the first and second embodiments, the discharge amount can be adjusted by changing the driving condition, and the density difference can be eliminated. As shown in FIG. 11, also in the third embodiment, the driving condition A and the driving condition B are switched in a stepwise manner in consideration of the fact that the recording head 8 gradually increases in temperature. It is desirable to switch so as to reduce the ratio of A.

  In the fourth embodiment of the present invention, the head temperature is driven under a certain driving condition in the previous scan, and is driven under a different driving condition in the next scan so that the driving is not performed in a different driving condition in the next scan. Even so, this is an embodiment in which two drive conditions are mixed and recorded.

  Example 4 is an example applied when the support member that supports the recording head 8 provided with the heat generating element is formed of a resin member. That is, the fourth embodiment is applied to a configuration in which the heat generated by the recording head 8 is less likely to escape to the support member and the temperature of the recording head 8 itself is higher than when the member having a large heat capacity such as alumina is configured as the support member. This is an embodiment.

  FIG. 12 is an explanatory diagram of a print pattern according to the fourth embodiment of the present invention. Similarly to the first embodiment, FIG. 12 is an explanatory diagram of a print pattern when recording is performed with a print duty of 100% in one pass.

  That is, the fourth embodiment shown in FIG. 12 shows the recording of three scans in which the driving conditions change. Of the three scan recordings, when the first stage recording is performed, it is assumed that the head temperature before the scanning is 27 ° C., and driving is performed under the driving condition A as shown in FIG.

  When the head temperature before scanning reaches 42 ° C., the second-stage recording is executed among the recordings of the three scans. At this time, in the table shown in FIG. . In such a situation, if the driving condition is changed in the second stage, the density difference between the recorded prints becomes conspicuous. Therefore, the driving is performed with the mixing ratio of the driving condition A and the driving condition B being 50%.

  Next, when the head temperature before scanning reaches 50.degree. C., printing at the third stage is performed.

  Here, in the third embodiment, the mixing ratio of the driving condition A and the driving condition B in the second stage is set to 50%. However, as in the first embodiment, it is desirable to change the mixing ratio according to the printing duty. .

  Further, the switching method between the driving condition A and the driving condition B in the second stage is the same as in the first embodiment, considering that the recording head 8 gradually rises in temperature, in a stepwise manner. It is desirable to switch to reduce the ratio.

According to the fourth embodiment, even in a head having a configuration that easily raises the temperature, similarly to the first embodiment, the ink discharge amount can be adjusted and the density difference can be eliminated by changing the driving conditions.

  In the fifth embodiment of the present invention, for example, when recording a multi-pass, which is used when recording a photo image, when the head temperature rises, the two driving conditions are mixed and recorded, whereby the density is increased. In this embodiment, the control is performed so that the difference becomes inconspicuous.

  FIG. 13 is an explanatory diagram of a printing pattern when recording is performed with four passes and a printing duty of 100%.

  FIG. 13 mainly shows recording of nine scans in which the driving conditions change.

  Also in the fifth embodiment, the mixing ratio of the driving condition A and the driving condition B is changed according to the head temperature before scanning and the print duty. For example, the head temperature gradually increases from the first scan to the ninth scan, and the mixing ratio of the driving condition A and the driving condition B is set to 100%, 87.5%, 75%, 62.5%, 50%. Gradually change the mixing ratio to 37.5%, 25%, 12.5%, 0%.

  According to the fifth embodiment, even during multi-pass printing, as in the first to fourth embodiments, the ink discharge amount can be adjusted and the density difference can be eliminated by changing the driving conditions in stages. .

  In the above embodiment, the drive condition storage means for storing the drive condition of the print head supplied to the print head 8, the temperature detection means for detecting the temperature of the print head 8, and the print duty determination for determining the print duty in the scanning direction. Means. When recording in the scanning direction, the first driving condition and the second driving condition stored in the driving condition storage unit are mixed and driven, and the recording in the scanning direction is performed according to the head temperature information and the print duty information. The mixing ratio of the first driving condition and the second driving condition is changed.

  Accordingly, since the driving condition is changed according to the temperature rise of the recording head 8, the density difference caused by the change in the ejection amount of the ejected ink droplets can be reduced and made inconspicuous. Therefore, it is possible to obtain a print image with good image quality in which density unevenness and the like are not conspicuous.

Further, the present invention has various effects such that the drive pulse control in the drive circuit may not be precise, and the capacity of the memory storing the drive conditions may be reduced.

1 is a diagram illustrating a configuration of a control circuit of an ink jet recording apparatus 100 that is an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of a driving pulse for driving the recording head 8. FIG. It is a figure explaining an example of the memory content of drive condition memory ROM14. It is a figure which shows the example which changes the mixing ratio of the drive condition A and the drive condition B in 1 scan according to head temperature and an average printing duty. FIG. 6 is a diagram illustrating a relationship between an ink ejection amount and a head temperature when driven under driving conditions A and B. An example in which the mixing ratio between the driving condition A and the driving condition B is changed during one scan according to the head temperature and the average printing duty, and the mixing ratio between the driving condition B and the driving condition C per scan is It is a figure which shows the example changed in 1 scan. FIG. 3 is an explanatory diagram of Embodiment 1 of the present invention, and is an explanatory diagram of a printing pattern when the recording head 8 repeats recording by reciprocation in the scanning direction and performs recording with “1 pass” and a printing duty of 100%. . It is explanatory drawing of the printing pattern at the time of recording by making an average printing duty into 50% by 1 pass. FIG. 8 is a diagram illustrating five scan recordings including scan recordings in which drive conditions change when 100% recording is performed in one pass, as in FIG. 7. It is explanatory drawing of the printing pattern in Example 2 of this invention, and it is explanatory drawing of the printing pattern at the time of recording by 100% of printing duty by 1 pass similarly to Example 1. FIG. It is explanatory drawing of the printing pattern in Example 3 of this invention, It is explanatory drawing of the printing pattern at the time of recording by 100% of printing duty by 1 pass similarly to Example 1,2. It is explanatory drawing of the printing pattern in Example 4 of this invention, It is explanatory drawing of the printing pattern in the case of recording by 100% of printing duty by 1 pass similarly to Example 1. FIG. It is explanatory drawing of the printing pattern at the time of recording by printing pass 100% by 4 passes. FIG. 10 is an enlarged schematic diagram illustrating an example of a printed image when a driving condition is changed in a conventional inkjet recording apparatus. It is a figure which shows the relationship between head temperature and discharge amount when it drives by drive condition (alpha) and drive condition (beta).

Explanation of symbols

100: Inkjet recording apparatus,
1 ... System controller,
7: Recording control unit,
8: Recording head,
9: Recording element,
11 ... temperature detection means,
12: Print duty counter,
13 ... Driving condition setting circuit,
14: Drive condition storage ROM.

Claims (9)

In a recording apparatus that forms an image on a recording material using a recording head provided with a plurality of nozzles that eject ink and an ejection energy generating element that ejects the ink.
Driving condition storage means for storing a driving condition of the recording head that is supplied to the recording head and drives the heating element;
Temperature detecting means for detecting the temperature of the recording head;
A print duty determining means for determining a print duty in the scanning direction;
Mixing means for mixing a plurality of drive conditions stored in the drive condition storage means at the time of recording for one scan;
Changing means for changing a mixing ratio of the plurality of driving conditions during the recording of the one scan in accordance with the detected temperature of the recording head and the determined printing duty;
A recording apparatus comprising: In claim 1,
One of the plurality of driving conditions is a condition for driving the recording head by a preheat pulse and a main heat pulse, and the other one of the plurality of driving conditions is a main driving condition. A recording apparatus characterized in that the recording head is driven only by a heat pulse. In claim 1,
A recording apparatus that switches and controls a driving condition for driving by mixing a plurality of driving conditions at the time of the recording at each recording timing of the one scan. In claim 1,
A recording apparatus, wherein a driving condition for driving by mixing a plurality of driving conditions is switched and controlled for each nozzle of the recording head. In claim 1,
A recording apparatus, wherein a driving condition for driving by mixing a plurality of driving conditions is switched for each nozzle of the recording head and is switched for each recording timing of one scan. In claim 1,
A recording apparatus, wherein a mixing ratio of a plurality of driving conditions is changed stepwise during the recording. In claim 1,
A recording apparatus characterized in that for each recording of one scan, the detected temperature of the recording head and the determined printing duty are acquired and a driving condition is determined. In claim 1,
When the driving condition determined in accordance with the detected recording head temperature and the determined printing duty is different from the driving condition before the recording, the detected recording head temperature is determined as the determination. A recording apparatus for recording according to a driving condition obtained by mixing a driving condition determined in accordance with a printing duty and a driving condition before the recording. In a control method of a recording apparatus for forming an image on a recording material using a recording head provided with a plurality of nozzles for discharging ink and an ejection energy generating element for discharging the ink,
A drive condition storage step for storing a drive condition of a printhead that is supplied to the printhead and drives the heating element;
A temperature detecting step for detecting the temperature of the recording head;
A print duty determination step of determining a print duty in the scanning direction;
A mixing step of mixing a plurality of driving conditions stored in the driving condition storing step during recording of one scan;
A changing step of changing a mixing ratio of the plurality of driving conditions during the recording of the one scan in accordance with the detected temperature of the recording head and the determined printing duty;
A control method for a recording apparatus, comprising:

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