JP2006341570A - Inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet which suppresses an excessive increase in temperature of a recording head and an adverse effect thereof as much as possible without complicating a recording apparatus main body and control, and without causing noticeable density unevenness and hue unevenness in an output image. A recording apparatus and an inkjet recording method are provided.
A wait time before each recording scan is set in a stepwise manner in accordance with the information about the temperature of the recording head during recording and the width information of the recording medium. As a result, even when the temperature of the recording head gradually rises during recording, the color difference from the adjacent area can be changed in steps, so that the density unevenness caused by the difference in wait time can be reduced. Hue unevenness becomes difficult to detect.
[Selection] Figure 5

Description

  The present invention relates to an ink jet recording apparatus that ejects ink using thermal energy, and an ink jet recording method using the ink jet recording apparatus. Specifically, in a serial-type inkjet recording apparatus that sequentially forms images on a recording medium by intermittently repeating main scanning and sub-scanning, the main scanning is performed according to the heat storage state of the recording head and the recording width of the recording medium. It relates to means and methods for setting the waiting time between scans.

  In recent years, with the spread of the Internet and the like, recording apparatuses having functions such as printers, copiers, and facsimiles have been spread in offices and general households. Such a recording apparatus is widely useful in various states, such as a composite electronic device including a computer and a word processor, or an output device connected to a workstation.

  As a recording method of the recording apparatus, there are an electrophotographic method, an ink jet method, a thermal method, etc. Among them, the ink jet method is not only paper, OHP sheets and films, but also various materials such as cloth, cardboard, ceramics, metal, etc. It can also be recorded on a medium. Further, since printing is possible not only on a flat surface but also on a medium having unevenness and a curved surface, and an edge portion of the medium, it is also utilized as a business printer. Furthermore, the recording head can be made relatively compact, and high-definition images can be recorded at high speed. Furthermore, the running cost is low, the non-impact method is low in noise, and there are a number of advantages that a color image can be recorded with a simple configuration using multi-color ink. .

  Among the recording heads mounted on the ink jet recording apparatus, in particular, in the type that ejects ink using thermal energy, electrothermal transducers and electrodes are generally formed on the substrate by a semiconductor manufacturing process such as etching, vapor deposition, and sputtering. Is formed by forming a liquid channel wall, a top plate and the like. Therefore, since individual recording elements for ejecting ink as droplets can be manufactured with a relatively high density, further downsizing can be achieved. In addition, it has excellent ejection response frequency and is suitable for meeting recent demands for recording high-definition images at high speed. In such a recording head, a plurality of recording elements each having a liquid path for transporting ink and an electrothermal conversion element for causing film boiling in the ink in the liquid path are arranged in a high density. The configuration is common.

  However, in such a recording head, since the energy for ejection is generated by abruptly generating heat from the electrothermal conversion element provided in each recording element, the more the ejection is repeated, the more the recording head Heat storage proceeds and this heat storage may be a problem. For example, as the heat storage of the recording head proceeds, the ink temperature in the liquid chamber also rises, and dissolved gas precipitates in the ink. Small bubbles generated in the individual liquid passages gradually grow with heat accumulation and eventually exist in a common liquid chamber communicating with the respective liquid passages. In this case, the large bubbles obstruct the ink supply to the common liquid chamber, and hence the ink supply to each liquid path, and obstruct the ink discharge from the discharge port of each recording element. In this way, even when a voltage pulse according to image data is applied to the electrothermal conversion element, the fact that sufficient ejection is not performed from each recording element is generally referred to as non-ejection. In an ink jet recording head, such non-ejection occurs when the temperature rises excessively, affecting the image quality and causing damage to the recording head. Such a heat storage problem becomes more prominent because a higher frequency drive is realized at a higher density as an attempt is made to achieve higher speed and higher density output.

  In order to avoid the adverse effects caused by the heat storage problem as described above, a method for controlling the recording method by detecting the temperature of the recording head during recording and comparing the detected temperature with a predetermined threshold is known. It has been. For example, when the detected temperature is higher than a threshold value, there is a method of suppressing the heat storage by reducing the drive frequency (discharge frequency) of the recording head. Further, in the case of a serial type ink jet recording apparatus that forms an image by intermittently repeating the main scan of the recording head and the sub-scan of the recording medium, a predetermined waiting time is set before executing the next recording scan. It is also effective to provide a method for promoting the temperature drop of the recording head.

  Further, in a serial type ink jet recording apparatus, a method of executing recording control by using information about image data recorded by the recording head in each main scan as well as the detected temperature of the recording head has been devised. For example, Patent Document 1 discloses a method of changing a threshold value for comparison with a recording head in accordance with the number of pixels to be recorded (image data) in each recording scan. Also disclosed is a method of estimating the temperature of the recording head after the end of the next main scan based on the current detected temperature and the image data of the next main scan and setting the standby time according to the estimated temperature ( For example, see Patent Document 2.)

  By adopting the various methods described above, heat storage of the recording head can be suppressed. Therefore, it is possible to avoid various problems caused by the excessive temperature rise of the recording head, such as ink ejection becoming unstable and affecting the image quality, or causing the recording head to be damaged. ing.

JP 2002-355959 A JP 2001-113678 A

  However, in the various countermeasures as described above, the heat storage of the recording head could be suppressed, but there were cases where various problems were caused following this. For example, when a method of reducing the drive frequency (discharge frequency) of the print head when the detected temperature is higher than the threshold value, the relative speed of the print head to the print medium must be reduced in accordance with the drive frequency of the print head. Don't be. Such control for changing the drive frequency and relative speed within the same page requires a complicated drive mechanism configuration and drive control circuit. Therefore, there arises a problem that the cost of the entire apparatus increases.

  On the other hand, the method of providing a waiting time between each main scan does not require a complicated structure. However, in this method, harmful effects were confirmed in the recorded image. Specifically, the density and hue of the area recorded with the standby time interposed therebetween are sensed differently from the density and hue of the other areas, and are recognized as density unevenness and hue unevenness.

  In the following, in order to explain the cause and phenomenon of the density unevenness (or hue unevenness), a multipass recording method generally employed in an ink jet recording apparatus will be briefly described. A plurality of recording elements are arranged at a high density in a recording head mounted on the ink jet recording apparatus, and ink is ejected from each recording element in accordance with image data. However, since some variation is inevitably included between the plurality of recording elements in the manufacturing process of the recording head, the discharge amount and the discharge direction are not completely aligned. In an image in which main scanning is repeated in such an irregular state, the ejection characteristics of the individual recording elements appear remarkably, and image adverse effects such as stripes and uneven density are recognized. The multi-pass recording method is a recording method that is employed in order to suppress such image adverse effects.

  In the multi-pass recording method, image data that can be recorded by the recording head in one main scan is divided into a plurality of images, and an image is formed by a plurality of main scans sandwiching a predetermined amount of sub-scanning. That is, a line that can be recorded by one recording element in one main scan is formed by a plurality of recording elements by a plurality of main scans. Therefore, in the line, the influence of the ejection characteristics of one printing element is suppressed, and the ejection characteristics of each printing element are dispersed. Extreme streaks and irregularities are less likely to appear in the entire image, and a smooth image can be obtained.

  In such a multi-pass recording method, the number of multi-passes can be set variously. For example, in the case of two-pass multi-pass printing, image data that can be printed by one main scan is divided into two, and an image is formed by two main scans. In N-pass multi-pass printing, image data that can be printed by one main scan is divided into N pieces, and an image is formed by N main scans. The larger the value of N, the less the influence of the ejection characteristics of one printing element on one line, and the smoother the entire image.

  However, in the multi-pass printing method, the time difference between N main scans greatly affects the image density. In general, in an ink jet recording apparatus, the obtained image density and hue are different between when an image is formed in one main scan with respect to the same region and when an image is formed in a plurality of times. Are known. Further, for example, even when an image is formed by dividing into two times, it is also known that the image density and hue are affected by the time difference between the execution of the first main scan and the second main scan. These phenomena vary in appearance depending on the type of ink to be applied and the type of recording medium. However, it has been confirmed that image density and hue are affected at least by the time difference.

  Therefore, when the method of changing the standby time between each scanning scan and the multi-pass printing method are employed at the same time in order to avoid overheating of the printing head, the detected temperature of the printing head exceeds the threshold value. Therefore, only the area formed by the main scanning in which the standby time is set to a long time has a density and hue different from those of the other areas and becomes noticeable as unevenness.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to cause noticeable density unevenness and hue unevenness in an output image without complicating the recording apparatus main body and control. An object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method that suppress an excessive increase in temperature of the recording head and problems associated therewith as much as possible.

  Therefore, in the present invention, the recording scan for ejecting ink using thermal energy and ejecting ink based on the recording data while moving and scanning the recording head relative to the recording medium, and the recording scan are: In an ink jet recording apparatus that forms an image on the recording medium by repeating sub-scanning that intermittently conveys the recording medium in the intersecting direction, a temperature information acquisition unit that acquires information about the temperature of the recording head; The recording scan is executed according to the paper width detecting means for detecting the width of the recording medium, the temperature of the recording head indicated by the information obtained by the temperature information acquiring means, and the width obtained by the paper width detecting means. Setting means for setting a wait time to wait for the recording scan before.

  Further, the recording head that ejects ink using thermal energy is moved and scanned relative to the recording medium while ejecting ink based on the recording data, and the recording scan intersects the recording head. In an inkjet recording method for forming an image on the recording medium by repeating sub-scanning that intermittently conveys the recording medium, a temperature information acquisition step for acquiring information about the temperature of the recording head, and the width of the recording medium The recording scan before performing the recording scan according to the paper width detection step for detecting the temperature, the temperature of the recording head indicated by the information obtained by the temperature information acquisition step, and the width obtained by the paper width detection step And a setting step for setting a wait time for waiting.

  By adopting the above configuration, according to the present invention, even when the temperature of the recording head gradually rises during recording, the color difference from the adjacent region can be changed stepwise. The uneven density and the uneven hue caused by the difference in the waiting time are not easily detected.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification, “record” is not only formed when significant information such as characters and figures is formed, but also manifested so that human beings can perceive it visually. Regardless of whether or not the image, a pattern, a pattern, or the like is widely formed on the recording medium, or the medium is processed. “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall. Further, the term “ink” should be interpreted broadly in the same way as the definition of “recording” described above. When applied to a recording medium, it forms an image, a pattern, a pattern, etc., or processes the recording medium. It represents a liquid that can be subjected to the above processing (for example, coagulation or insolubilization of the colorant in the ink applied to the recording medium).

(First embodiment)
FIG. 1 is a schematic perspective view for explaining an internal mechanism of an ink jet recording apparatus applicable to this embodiment. In the figure, 1 is a transport motor. By driving the transport motor 1, the platen roller 2 rotates in the direction of arrow R in the figure, and the recording medium M is transported in the direction of arrow F. Guide shafts 3a and 3b are arranged in parallel in a direction orthogonal to the conveyance direction F (sub-scanning direction) of the recording medium M. The carriage 4 on which the ink jet recording head 5 is mounted is reciprocated (scanned) in the direction of the arrow S (main scanning direction) in the figure by driving the carriage motor 6 while being guided and supported by the guide shafts 3a and 3b. The recording head 5 mounted on the carriage 4 ejects ink according to the recording data during the moving scan of the carriage 4. When one recording scan is performed by the recording head 5, the recording medium M is transported by a predetermined amount by the transport motor 1.

  In the inkjet recording head 5 applied in the present embodiment, 1280 ejection ports (nozzles) are arranged at a pitch of 1200 dpi (dot / inch; reference value) in the sub-scanning direction. In the ink flow path (liquid path) communicating with each discharge port, an electrothermal converter is provided for heating the ink locally to cause film boiling and discharging the ink by the pressure. . The recording head 5 is provided with a diode sensor 50 (see FIG. 2) for detecting the temperature of the recording head 5 on the same substrate as the substrate on which the electrothermal transducer is provided.

  Further, the carriage 4 is provided with a paper width sensor 40 (see FIG. 2). The paper width sensor 40 reciprocates (scans) along the guide shafts 3 a and 3 b together with the carriage 4 and plays a role of detecting the width of the recording medium M.

  FIG. 2 is a block diagram for explaining the configuration of the control system of the ink jet recording apparatus according to the present embodiment. In the figure, reference numeral 20 denotes an interface for transmitting / receiving data such as image data and control commands to / from the host device H. An MPU 21 performs various controls of the entire recording apparatus. Programs and fixed data for the MPU 21 to control are stored in the ROM 22. A DRAM 23 temporarily stores various data (such as recording data to be supplied to the recording head 5) or is used as a work area for processing performed by the MPU 21.

  Reference numeral 24 denotes a gate array that controls supply of recording data to the recording head 5. The gate array 24 also controls data transfer among the interface 20, MPU 21, and DRAM 23. Reference numerals 25 and 26 denote motor drivers for driving the carriage motor 6 and the transport motor 1, respectively. Reference numeral 27 denotes a head driver for driving the recording head 5.

  Reference numeral 50 denotes a diode sensor for detecting the temperature of the recording head 5, and reference numeral 40 denotes a paper width sensor for detecting the paper width of the recording medium. Each detection data is sent to the MPU 21.

  A sequence for actually executing recording using the recording apparatus described above will be specifically described below.

  FIG. 3 is a flowchart for explaining a series of steps executed by the MPU 21 when an image for one page is recorded in the recording apparatus of the present embodiment. First, when recording is started in step S301, image data including control data is input from the host apparatus H to the MPU 21 via the interface 20 and the gate array 24 (step S302).

  In step S303, the MPU 21 feeds and conveys the recording medium M by driving the conveyance motor 1, and arranges it at a predetermined recording start position. Further, in step S304, the carriage motor 6 is driven to move and scan the carriage 4 by one reciprocation, and the width of the fed recording medium M is detected by the paper width sensor 40 provided in the carriage 4 at this timing. To do. The detected data is transferred to the MPU 21.

  In subsequent step S305, the MPU 21 acquires the temperature of the recording head 5 detected by the diode sensor 50 (hereinafter referred to as the head temperature TH), and this TH and a predetermined threshold temperature (hereinafter referred to as protection) stored in the ROM 22 in advance. (Referred to as temperature TP). If the head temperature TH is lower than the protect temperature TP, the process proceeds to step S308. On the other hand, if it is determined that the head temperature TH is higher than the protect temperature TP, the process proceeds to step S306, where the start of the next main scan is temporarily stopped and the head temperature is waited for to drop.

  After waiting for a predetermined time in step S306, the process proceeds to step S307 to newly detect the head temperature TH. Then, the obtained head temperature TH is compared with a predetermined main scanning permission temperature (hereinafter referred to as TK, TK <TP) stored in the ROM 22 in advance. Here, if TH> TK, it is determined that the recording head has not been sufficiently cooled to be worthy of recording, and the process returns to step S306 again to continue the recording interruption state. On the other hand, if TH <TK, it is determined that the recording head has been cooled sufficiently to resume recording, and the process proceeds to step S308.

  In the following description of FIG. 4, in this example, the recording interruption time in step S306 is 5 seconds. Further, the wait time in the present invention indicates a time for stopping the carriage for a short time immediately before the start of each printing scan, and is a value equal to or less than a waiting time (5 seconds) for interrupting printing. Further, the protect temperature TP is a temperature at which it is determined that it is better to temporarily stop the recording because there is a concern that the problem described in the section of the problem occurs in the discharge operation. In this example, the protect temperature TP is set to 80 ° C. Yes. On the other hand, the main scanning permission temperature TK is a temperature that is sufficiently lower than the protect temperature TP and at which it is determined that the interrupted recording operation may be resumed, and is 60 ° C. in this example.

  FIG. 4 is a table for explaining a wait time setting method in step S308. In the recording apparatus of the present embodiment, the wait time immediately before each recording scan is determined according to the paper width data detected in step S304 and the head temperature TH detected in step S305 or step S307. Further, the recording apparatus of the present embodiment is compatible with two-size recording media having a paper width of 24 inches and 44 inches, and FIG. 4 shows the wait time for the head temperature TH with respect to the two sizes of paper width. For example, when the paper width of the recording medium detected in step S304 is 44 inches and the head temperature TH detected in step S305 or step S307 is 65 ° C., the wait time is set to 3 seconds. Such wait time for the paper width data and the head temperature TH is stored in the ROM 22 in advance, and the MPU 21 sets the wait time by referring to the table. Then, the carriage 4 is made to wait according to the time.

  When the wait according to the set wait time is completed, the process proceeds to step S309, and one recording main scan is executed. That is, the MPU 21 drives the carriage motor 6 to move and scan the carriage 4 and drives the head driver 27 to drive the recording head 5 to eject ink according to the recording data.

  When one recording main scan in step S309 is completed, the process proceeds to step S310, and the MPU 21 conveys the recording medium M by driving the conveyance motor 1 by a predetermined amount.

  When the recording main scan for one row is completed in steps S309 and S310, the process proceeds to step S311 to determine whether or not the recording of image data for one page is completed in the recording main scan performed immediately before. If it is determined that there is still image data to be recorded, the process returns to step S305, and the head temperature TH is detected again for the next main printing scan. On the other hand, if it is determined in step S311 that the recording of all the image data has been completed, the process proceeds to step S312 and the MPU 21 drives the transport motor 1 to discharge the recording medium M on which the recording has been completed. Thus, the recording for one page is completed (step S313).

  As described above, in the recording apparatus according to the present embodiment, the temperature TH of the recording head 5 is detected at each recording scan, and after executing the weight corresponding to the temperature TH, the recording main scan is executed. That is, even if the detected temperature TH of the recording head is a temperature at which recording can be continued, the wait time between the recording scans is provided stepwise. Therefore, even when the head temperature TH gradually rises as recording continues, it can be gradually suppressed from during recording that this reaches the protect temperature TP not worthy of recording. Also, even if the recording is interrupted for 5 seconds when the protect temperature TP is reached, the recording standby is not performed for the first time here, and a certain level of standby (already in the continuous recording scanning performed in advance) (Wait) is interrupted after being made in steps of 1 second and 3 seconds. Therefore, even when the multi-pass printing method in which the time difference between the main scans greatly affects the image density and the hue is employed, the adverse effect as described in the section of the problem, that is, the head temperature TH is less than the protect temperature TP. It is difficult to confirm an adverse effect that the output density is increased only in the region formed by the main scanning executed after the threshold is exceeded.

  FIG. 5 shows the recording with the head temperature TH, the wait time, and the wait time when an image of 20% density is uniformly recorded for one page by the 2-pass multi-pass printing method according to the above-described recording method. 3 shows the color difference ΔE between the recorded area and the adjacent area recorded by the main scanning before and after this area. Here, as a comparative example for explaining the effect of the present invention, a conventional method in which the wait time corresponding to the head temperature TH is not particularly set and the recording operation is interrupted for 5 seconds when the protect temperature TP is reached. The results by are also shown.

  First, a case where a recording medium having a width of 44 inches is detected will be described. Referring to FIG. 4, in the case of a recording medium having a width of 44 inches, when the head temperature TH reaches 50 ° C., a wait time of 1 second is set. When two-pass multi-pass printing is performed, two print main scans are performed at a constant interval when the head temperature is 50 ° C. or lower. However, in the print scan when the head temperature TH reaches 50 ° C., the above-mentioned fixed interval is used. An image is formed by two recording scans added by 1 second. In this case, as described in the background art section, this area forms a different density and hue with respect to the previously formed area. In the present embodiment, the color difference ΔE between the two regions obtained here is 1. However, a color difference of about ΔE = 1 can be regarded as a level that is not so problematic visually.

  When the head temperature TH reaches 60 ° C., a wait time of 3 seconds is provided. However, since the wait time of 1 second has already been set in the main scanning so far, the color difference ΔE from the adjacent area is suppressed to about 3, and this color difference is not so problematic visually. It can be regarded as a level. Further, when the head temperature reaches 70 ° C., a wait time of 5 seconds is provided. However, since the wait time of 3 seconds has already been set in the main scanning so far, the color difference ΔE from the adjacent region is still the same. It is suppressed to about 3. Furthermore, when the head temperature TH reaches 80 ° C., it waits for about 5 seconds until the head temperature drops to the main scanning permission temperature TK of 60 ° C., but the wait time of 5 seconds has already been set in the previous main scanning. Therefore, the color difference ΔE from the adjacent area is within 0.6.

  On the other hand, when a recording medium having a width of 24 inches is detected, the main scanning width is shorter than that of 44 inches, so the rate of increase in head temperature in one recording main scanning is low. Therefore, the wait time may be set after the head temperature TH is closer to the protect temperature. In this embodiment, a wait time of 1 second is provided when the head temperature reaches 65 ° C., 3 seconds when the head temperature reaches 70 ° C., and 5 seconds when the head temperature reaches 75 ° C. As shown in FIG. 5, the color difference ΔE with respect to each wait time is equivalent to the case of the 44 inch width.

  On the other hand, in the comparative example, the wait time is not set until the head temperature TH reaches the protect temperature TP. That is, the interruption (standby) of about 5 seconds is performed for the first time when the head temperature reaches the protect temperature of 80 ° C. Accordingly, the color difference ΔE from the previous area where no weight is applied is 6. This value is large enough to be recognized as uneven density or uneven hue.

  As described above, according to the present embodiment, even when the multi-pass printing method in which the time difference between the main scans tends to affect the image density is adopted, a complicated drive mechanism configuration or drive control circuit is used. The problem described in the problem section, that is, the problem that the output density is increased only in the region formed by the main scanning performed after the head temperature TH exceeds the protect temperature TP. Can be suppressed.

  In this embodiment, one feature is that the wait time for each scan can be set according to the head temperature TH and the recording width. In the case of a wide recording medium in which the head temperature is likely to rise more rapidly, a longer wait time is set in advance, and in the case of a narrow recording medium in which the head temperature is difficult to rise, the wait time is set longer than necessary. It is set not to be long. The increase rate of the head temperature in each recording scan is easily affected by the width of the recording medium. Therefore, the wait time stored in the ROM in advance is stored in a state where the expected increase in the head temperature is anticipated depending on the recording medium width, so that the wait time that more appropriately matches the recorded image is set. It can be done. In other words, it is possible to prevent image unevenness due to multi-pass recording and standby time as much as possible, and to realize image output with appropriate quality and throughput according to the head temperature rise level without providing wait time more than necessary. Is possible.

(Second Embodiment)
The second embodiment of the present invention will be described below. Also in the present embodiment, as in the first embodiment, the ink jet recording apparatus having the configuration described with reference to FIGS. 1 and 2 is applied, and the recording operation is performed in the process described with reference to FIG. However, in the present embodiment, it is possible to select two types of recording modes for executing the 2-pass and 6-pass multi-pass recording methods for the same size recording medium.

  FIG. 6 is a diagram for explaining a wait time setting table corresponding to the detected width of the recording medium and the recording mode. When multi-pass printing is employed, the larger the number of multi-passes, the lower the number of times the print head discharges in one print main scan, so the temperature rise rate of the print head is also reduced. Therefore, in the 6-pass printing of this embodiment, the wait time is provided after the head temperature TH is closer to the protect temperature TP than in the 2-pass printing, and the set time is set relatively short.

  FIG. 7 shows the head temperature TH, the wait time, and the wait time when an image of 20% density is uniformly recorded for one page by the multipass printing method according to the printing method of the present embodiment. The color difference ΔE between the recorded main scanning area and the main scanning areas before and after the main scanning area is shown in the same manner as in the first embodiment.

  In the figure, a case of a recording medium having a width of 44 inches will be described as an example. Referring to FIG. 6, when 6-pass multi-pass printing is performed on a recording medium having a width of 44 inches, a wait time of 1 second is set when the head temperature TH reaches 60 ° C. The color difference ΔE obtained at this time is about 0.3, which is a smaller value than the two-pass printing mode. After that, when the head temperature reaches 70 ° C., the wait time is 3 seconds, and when the head temperature reaches 80 ° C. which is the protect temperature, the interruption is executed for about 5 seconds, but the color difference ΔE is within about 1 and 0.5, respectively. .

  On the other hand, even in the case of a 24-inch width recording medium, the wait time is set after the head temperature reaches 70 ° C., but the color difference ΔE with respect to each wait time is larger than that in the case of multi-pass recording of two passes. Can be confirmed to be smaller.

  In general, in multi-pass printing, the image quality increases as the number of passes increases, but the printing time increases as the number of printing scans increases. Therefore, in the ink jet recording apparatus, in general, a plurality of recording modes having different numbers of multi-passes are prepared as in the present embodiment in accordance with the use of the image to be recorded and the user's preference. The user selects the low-speed recording mode with a larger number of multi-passes when he wants to realize a high-quality image over time, and the high-speed recording with a smaller number of multi-passes when he wants to output images at a higher speed. The mode can be selected. In the present embodiment, in the low-speed recording mode where the number of multi-passes is originally large and the color difference ΔE is difficult to be confirmed, the wait time is set to be relatively short so that the recording time is not further extended. On the other hand, in a high-speed recording mode in which the number of multi-passes is small and the color difference ΔE is confirmed, an appropriate wait time is set according to the detected temperature of the recording head, and the color difference is suppressed to the extent that the influence is not as much as possible. Yes.

  As described above, according to this embodiment, even when the multi-pass printing method in which the time difference between the main scans greatly affects the image density is provided as a plurality of print modes having different multi-pass numbers. The problem described in the section of the problem, that is, the problem that the output density is increased only in the area formed by the main scanning performed after the head temperature TH exceeds the protect temperature TP, is recorded for each recording. It becomes possible to suppress in an appropriate state according to the mode.

  In the above description of the embodiment, the configuration in which the temperature of the recording head is detected by the diode sensor 50 has been described as an example, but information indicating the temperature obtained by the detection is stored in a RAM (for example, DRAM) in the apparatus. In addition, the temperature information may be acquired from the RAM when necessary. In this case, by making the information in the RAM updated each time detection is performed, it is possible to acquire information on the temperature detected at the closest timing when making the determination.

  Further, the present invention is not limited to a configuration in which the temperature of the recording head is acquired using a sensor, but can also be applied to a configuration in which the temperature of the recording head is obtained by estimation. In this case, it is possible to know the temperature of the recording head by storing information on the temperature obtained by estimation in the RAM and reading the information as necessary.

  In the embodiment described above, the mechanism is provided with the paper width sensor 40 for detecting the width of the recording medium as means for detecting the paper width. However, the present invention is not limited to such a configuration. The width of the recording medium may be detected by other configuration means provided in the recording apparatus main body, or may be configured to be input / set by the user from the recording apparatus or the host apparatus H connected thereto. good. Of course, the size of the paper width that can be recorded by the recording apparatus is not limited to two types of 24 inches and 44 inches, but may be configured to have a table adapted to more sizes.

  Further, in the second embodiment, the recording apparatus having two types of recording modes of 2 pass and 6 pass has been described. However, the recording apparatus of the present invention can be applied to more types of recording media, for example. A configuration having a recording mode may be used. In this case, it is expected that the density unevenness and hue unevenness will vary depending on the type of recording medium. Therefore, a plurality of types of tables as described with reference to FIG. 4 may be prepared according to the type of recording medium.

  Furthermore, in the present invention, the methods of Patent Document 1 and Patent Document 2 can be used in combination with the recording method described above. In this way, not only can the above-described effects of the present invention be obtained, but also the protection temperature TP is reached by using information relating to image data recorded by the recording head in each main scan together with the detection temperature TH of the recording head. The previous effective recording operation can be realized.

1 is a schematic perspective view for explaining an internal mechanism of an ink jet recording apparatus applicable to an embodiment of the present invention. FIG. 2 is a block diagram for explaining a configuration of a control system of an inkjet recording apparatus applicable to the embodiment of the present invention. 5 is a flowchart for explaining a series of steps executed by the MPU when recording an image for one page in the embodiment of the present invention. It is a figure for demonstrating the setting table of the wait time in the 1st Embodiment of this invention. In the first embodiment of the present invention, the head temperature TH, the wait time, and the color difference ΔE between the main scanning area recorded with the waiting time and the main scanning area before and after the main scanning area are shown. It is a figure for demonstrating the setting table of the wait time in the 2nd Embodiment of this invention. In the second embodiment of the present invention, the head temperature TH, the wait time, and the color difference ΔE between the main scan area recorded with the wait time and the main scan area before and after the main scan area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conveyance motor 2 Platen roller 3a, 3b Guide shaft 4 Carriage 5 Recording head 6 Carriage motor 7 Conveyance motor M Recording medium H Host apparatus 20 Interface 21 MPU
22 ROM
23 DRAM
24 Gate array 25 Motor driver 26 Motor driver 27 Head driver 40 Paper width sensor 50 Diode sensor

Claims (8)

A recording scan that ejects ink based on recording data while moving and scanning a recording head that discharges ink using thermal energy relative to the recording medium, and the recording medium in a direction intersecting the recording scan In an inkjet recording apparatus that forms an image on the recording medium by repeating sub-scanning that intermittently conveys
Temperature information acquisition means for acquiring information about the temperature of the recording head;
Paper width detecting means for detecting the width of the recording medium;
In accordance with the temperature of the print head indicated by the information obtained by the temperature information acquisition means and the width obtained by the paper width detection means, a wait time for waiting for the print scan is set before executing the print scan. Setting means;
An ink jet recording apparatus comprising:   2. The ink jet recording apparatus according to claim 1, wherein the setting unit sets the wait time to be longer as the temperature of the recording head is higher.   The inkjet recording apparatus according to claim 1, wherein the setting unit sets the wait time to be longer as the width of the recording medium is larger.   4. The inkjet recording apparatus according to claim 1, further comprising a table referred to for setting the wait time according to a temperature of the recording head and a width of the recording medium. Inkjet recording apparatus.   The inkjet recording apparatus according to claim 4, wherein the inkjet recording apparatus has a plurality of recording modes having different recording operations, and the table is prepared for each recording mode.   Means for preventing the recording scan from being executed when the temperature of the recording head is equal to or higher than a first threshold value until the detected temperature becomes equal to or lower than a second threshold value lower than the first threshold value; The ink jet recording apparatus according to claim 1, further comprising: an ink jet recording apparatus according to claim 1.   7. The ink jet recording apparatus according to claim 1, wherein the paper width detecting unit includes a mechanism for measuring the width of the recording medium. A recording scan that ejects ink based on recording data while moving and scanning a recording head that discharges ink using thermal energy relative to the recording medium, and the recording medium in a direction intersecting the recording scan In the inkjet recording method of forming an image on the recording medium by repeating sub-scanning that intermittently conveys
A temperature information acquisition step of acquiring information about the temperature of the recording head;
A paper width detection step of detecting the width of the recording medium;
In accordance with the temperature of the print head indicated by the information obtained by the temperature information acquisition step and the width obtained by the paper width detection step, a wait time for waiting for the print scan is set before executing the print scan. A setting process;
An ink jet recording method comprising:

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