JP2022122137A - Recording apparatus - Google Patents

Abstract

To provide a recording apparatus capable of inhibiting accumulation of scorch caused by ink containing resin particulates associated with preliminary discharge.SOLUTION: A recording apparatus includes: a recording head for discharging ink to a recording medium; preliminary discharge control means for making the recording head perform preliminary discharge; and recovery control means for performing recovery processing of the recording head depending on the number of times of the preliminary discharge when executing the preliminary discharge.SELECTED DRAWING: Figure 7

Description

The present invention relates to recording apparatuses.

2. Description of the Related Art A printing apparatus is known that prints an image on a print medium by ejecting ink while scanning a print head relative to the print medium in a scanning direction. In order to maintain a proper ink ejection state at all times, the printing apparatus ejects a small amount of ink at a predetermined location at certain time intervals, irrespective of the printing data, called "intra-page preliminary ejection" or "preliminary ejection." There is something that does Moreover, in recent years, various types of recording media and inks have been used in recording apparatuses in order to record on a variety of recorded materials. It is designed to improve fixation to.

JP-A-2002-361889

In ink containing such fine resin particles, the fine resin particles may deposit as kogation on the recording elements that eject the ink to each nozzle. The accumulation of burnt deposits is greater in a recording element that has no recording data and performs preliminary ejection without recording ejection than in a recording element that has recording data and performs ejection and preliminary ejection during recording. Easy to deposit. Therefore, it is important to grasp the number of preliminary ejections, estimate the degree of kogation accumulation, and suppress the kogation accumulation. However, although it is possible to determine the amount of preliminary ejection of the print head in Patent Document 1, the number of preliminary ejections during printing of the print head is not counted, and the state of kogation cannot be accurately estimated. In some cases, the deposition of kogation cannot be suppressed.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording apparatus capable of suppressing the deposition of burnt deposits due to ink containing fine resin particles during preliminary ejection. .

In order to achieve the above object, the recording apparatus according to the present invention comprises:
a recording head that ejects ink onto a recording medium;
preliminary ejection control means for causing the recording head to perform preliminary ejection;
recovery control means for performing recovery processing of the print head according to the number of times the preliminary ejection is performed;
Prepare.

According to the present invention, it is possible to provide a recording apparatus capable of suppressing the deposition of burnt deposits due to ink containing fine resin particles that accompanies preliminary ejection.

Schematic explanatory diagram of an inkjet recording apparatus according to the present embodiment Nozzle arrangement diagram in the print head according to the present embodiment FIG. 2 is an enlarged cross-sectional view of the ejection port of the print head according to the present embodiment; FIG. 1 is a block diagram showing the configuration of an inkjet printing apparatus according to this embodiment; FIG. 4 is a diagram showing the data processing process of the inkjet printing apparatus according to the present embodiment; FIG. 2 shows a reflective optical sensor according to the present embodiment; 3 is a flow chart showing kogation suppression control according to the first embodiment. Schematic diagram when ink containing fine resin particles is ejected from the recording element of the inkjet recording apparatus according to the present embodiment. Schematic diagram in the case where only preliminary ejection of ink containing fine resin particles is repeated in the recording element of the inkjet recording apparatus according to the present embodiment. Flowchart showing kogation deposition suppression control according to the second embodiment Table showing the correspondence between the number of recording shots and the counter for the number of preliminary ejections according to the second embodiment A diagram of an ejection detection mechanism according to the present embodiment. 7 is a flow chart showing control for performing preliminary ejection after printing according to the present embodiment based on ejection test results for only ink containing fine resin particles.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

<Recording device configuration>
An inkjet recording apparatus according to this embodiment will be described with reference to the drawings.

FIG. 1 shows the appearance of an inkjet recording apparatus (hereinafter also referred to as a recording apparatus or printer) according to this embodiment. This is a so-called serial scanning printer, which scans the recording head in the X direction (scanning direction) perpendicular to the Y direction (conveying direction) of the recording medium P to record an image.

The outline of the configuration of this ink jet recording apparatus and the operation during recording will be described with reference to FIG. First, the recording medium P is conveyed in the Y direction from the spool 101 holding the recording medium P by a conveying roller driven by a conveying motor (not shown) via a gear. On the other hand, at a predetermined transport position, the main scanning motor causes the carriage unit 102 to reciprocate (reciprocate) along the guide shaft 103 extending in the X direction in the +X direction and the −X direction. In the process of this scanning, the recording medium P is synchronized with the timing based on the position signal obtained by the encoder 106 in the main scanning direction, and the recording medium P is ejected from the ejection openings of the recording head 105 that can be mounted on the carriage unit 102 . to record.

A reflective optical sensor 107 is attached to the carriage unit 102 to obtain the color development characteristics of the recording medium. Similar to the recording head 105, it synchronizes with the timing based on the position signal obtained by the encoder 106 during the reciprocating scanning process, and processes the detection signal corresponding to the position of the carriage unit 102. FIG. A carriage belt can be used to transmit the driving force from the main scanning motor to the carriage unit 102 . However, instead of the carriage belt, for example, a lead screw that is rotationally driven by a main scanning motor and extends in the X direction, and an engaging portion that is provided in the carriage unit 102 and engages with the groove of the lead screw. Other drive schemes can also be used.

The fed print medium P is nipped and conveyed between a paper feed roller (not shown) and a pinch roller (not shown), and guided to a print position (print head scan area) on the platen 104 . Since the face of the printhead 105 is capped in a normal rest state, the cap 108 is opened prior to printing to make the printhead 105 or carriage unit 102 scannable.

After that, when data for one scan is accumulated in the buffer, the carriage unit 102 is caused to scan by the main scanning motor 420, and printing is performed as described above. Also, the cap 108 covers and caps the recording head 105 when the carriage unit 102 is at the home position. This prevents the ink from evaporating from the ejection openings of the print head 105, thereby preventing ejection failure due to an increase in the viscosity of the ink or evaporation and adhesion of volatile components. The inside of the cap 108 communicates with a pump unit (not shown). For example, when the printhead 105 has an ejection failure, the pump unit performs suction recovery by bonding the cap 108 and the printhead 105 together, and when performing empty suction of the ink ejected into the cap 108 . Apply negative pressure as needed. As a result, the cap 108 can remove ink adhering to the vicinity of the ejection openings of the print head 105 .

FIG. 2 shows an arrangement diagram of nozzles (ejection ports) in the print head 105 according to this embodiment. The recording head 105 is composed of non-fluorescent ink and fluorescent ink, and has an ejection port array 201 that ejects black ink, an ejection port array 202 that ejects cyan ink, an ejection port array 203 that ejects magenta ink, and an ejection port array 203 that ejects yellow ink. It has an ejection port array 204 that Since these black ink, cyan ink, magenta ink, and yellow ink contain only the corresponding colorants, these inks will also be referred to as non-fluorescent inks for the sake of simplicity in the following description. The print head 105 also includes an ejection port array 205 that ejects fluorescent ink. Fluorescent ink can form an image on a recording medium as a fluorescent ink by dyeing resin fine particles with a fluorescent material. That is, in this specification, fluorescent ink is an example of ink containing a resin component such as resin fine particles, and non-fluorescent ink is an example of ink that does not contain a resin component. In this embodiment, the content concentration of the fine resin particles in the fluorescent ink is set to 5%.

In the print head 105, these ejection port arrays are arranged in the order of ejection port arrays 201, 202, 203, 204, and 205 from the + side to the - side in the X direction. In these ejection port rows 201, 202, 203, 204, and 205, 1280 ejection ports 200 for ejecting ink are arranged in the Y direction (arrangement direction) at a density of 1200 dpi. It should be noted that the ejection amount of ink ejected at one time from one ejection port 200 in this embodiment is approximately 4.5 pl. These ejection port arrays 201, 202, 203, 204, and 205 are connected to ink tanks (not shown) that store corresponding ink, respectively, and are supplied with ink. Note that the print head 105 and the ink tank used in this embodiment may be configured to be separable from each other, or may be configured integrally.

FIG. 3 is an enlarged cross-sectional view of one ejection port 200 in the XY plane. A driving pulse is applied to the ejection heater 300 according to print data received from the inkjet printing apparatus, thereby driving the ejection heater 300 to generate heat. This thermal energy causes the ink on the ejection heater 300 to undergo film boiling, that is, the ink undergoes a change in state to form bubbles. action is performed. The ejection heaters 300 are sometimes called printing elements.

FIG. 4 is a block diagram showing a configuration example of a printing apparatus according to this embodiment. A controller 400 as a main control unit has, for example, a CPU 401 in the form of a microcomputer, a ROM 402 that stores programs, required tables, and other fixed data, and a RAM 403 that has an area for developing image data, an area for working, and the like. . In addition, the controller 400 executes processing for adjusting the landing position, which will be described later. An adjustment value for adjusting the impact position is set by the process for adjusting the impact position, and the adjustment value is used to adjust the impact position in the subsequent recording process. The controller 400 also functions as a preliminary ejection control unit that causes the print head 105 to perform a preliminary ejection operation and a recovery control unit that causes the print head 105 to perform recovery processing, as will be described later.

The host device 404 is a supply source of image data, and may be in the form of a computer that creates and processes data such as images to be printed, or in the form of a reader for reading images. Image data, other commands, status signals, etc. are transmitted and received to and from the controller 400 via an interface (I/F) 405 . An operation unit 406 is a group of switches for receiving instructions input by the operator, and includes a power switch 407, a switch 408 for instructing the start of printing, and an instruction to start a predetermined recovery process such as a suction recovery operation for the print head 105. It has a recovery switch 409 for In one example, the operation unit 406 may have a landing position adjustment activation switch 410 for adjusting the landing position. In this embodiment, the recording start, recovery operation, and landing position adjustment are performed by switches provided on the main body. However, it may be executed based on instructions from the host device 404 .

A sensor group 411 is a sensor group for detecting the state of the printing apparatus, and includes the reflective optical sensor 107, a photocoupler 412 for detecting the home position, an ejection detection unit 450, and appropriate parts for detecting the environmental temperature. It has a temperature sensor 413 provided in.

A head driver 414 is a driver that drives the ejection heaters 300 of the print head 105 according to print data and the like. The head driver 414 includes a shift register that aligns print data in correspondence with the positions of the ejection heaters 300, a latch circuit that latches at appropriate timing, and a logic circuit element that operates the ejection heaters 300 in synchronization with drive timing signals. .

A sub-heater 418 is provided in the print head 105 . The sub-heater 418 performs temperature adjustment for stabilizing ink ejection characteristics. The sub-heater 418 may be formed on the printhead substrate like the ejection heater 300 or may be attached to the printhead 105 .

A main scanning motor driver 415 is a driver for driving the main scanning motor 420 . The main scanning motor 420 is a motor used for reciprocating scanning (reciprocating movement) of the carriage unit 102 along the guide shaft 103 as described above. A sub-scanning motor driver 416 is a driver for driving the sub-scanning motor 421 . The sub-scanning motor 421 is a motor used for conveying (moving in the sub-scanning direction) the recording medium P via a conveying roller. A recovery processing unit 517 performs recovery processing for maintaining a good ink ejection state in the print head 105 .

FIG. 5 is a flow chart for explaining the process of processing image data in this embodiment. Image data to be printed by the inkjet printing apparatus 1 is created via the application J101 of the host device 404 . When printing, the image data created by the application J101 is transmitted to the printer driver 500. FIG.

The printer driver 500 executes pre-processing J0002, post-processing J0003, gamma correction J0004, and binarization processing J0005 on the created image data. In the pre-process J0002, color gamut conversion is performed to convert the color gamut of the display of the host computer 115 into the color gamut of the printer 1 . By using the three-dimensional lookup table, image data R, G, and B in which R, G, and B are each represented by 8 bits are converted into 8-bit data R, G, and B within the color gamut of the printer. In post-processing J0003, the colors for reproducing the converted color gamut are decomposed into ink color gamuts. A process for obtaining 8-bit data (image data) corresponding to the combination of inks for reproducing the colors represented by the 8-bit data R, G, and B within the print color gamut obtained in the preceding process J0002 is performed. In the γ correction J0004, γ correction is performed on each of the 8-bit data (image data) obtained by color separation. Each of the 8-bit data obtained in post-processing J0003 is converted so as to be linearly associated with the gradation characteristics of the inkjet printing apparatus, and 8-bit data (correction data) corresponding to the combination of inks is obtained. In the binarization processing J0005, each of the 8-bit data (correction data) obtained by the γ correction J0004 is converted into 1-bit data to perform quantization processing to generate binary data. As this quantization process, any quantization method such as a density pattern method, a dither method, an error diffusion method, or the like can be adopted. The data generated as described above is supplied to the inkjet recording apparatus 1 .

In the mask data conversion process J0008, the binary data created in the binarization process J0005 and the mask pattern stored in the ROM 402 are used to convert into print data representing ink ejection/non-ejection. This mask pattern is formed by arranging print permitting pixels that permit ink ejection and print non-permitting pixels that do not permit ink ejection in a specific pattern. Note that the mask pattern used in the mask data conversion process J0008 is stored in advance in a predetermined memory within the inkjet printing apparatus.

For example, by storing a mask pattern in the ROM 402 and using this mask pattern, the CPU 401 can perform conversion into print data. Print data obtained by mask data conversion processing is supplied to the head driver 414 and the print head 105 . Based on this print data, ink is ejected onto the print medium P from each ejection port arranged in the print head 105 . Based on the print data created by the processing described above, the drive of each motor, print head, etc. is controlled to perform the print operation.

Also, registration adjustment for fluorescent ink and non-fluorescent ink will be described. 6A and 6B are schematic diagrams for explaining the reflective optical sensor 107 that acquires the color development characteristics of the recording medium shown in FIG.

The reflective optical sensor 107 is attached to the carriage unit 102 as described above, and the measurement area is located downstream of the recording surface of the recording head 105 in the transport direction (Y direction). The lower surface of the reflective optical sensor 107 is arranged at the same position as or higher than the lower surface of the recording head 105 .

FIG. 6A shows a cross-sectional view of the reflective optical sensor 107. FIG. A light-emitting portion 601 realized by visible LEDs of red, green, blue, or the like, and a light-receiving portion 602 realized by a photodiode are provided. A light 603 emitted from the light emitting unit 601 is irregularly reflected at a detection spot 605 on the recording medium P, and the irregularly reflected light 604 can be detected by the light receiving unit 602 .

FIG. 6(b) shows a detection spot 605 by the reflective optical sensor 107. FIG. A detection spot 605 where the light 603 emitted from the light emitting unit 601 is irregularly reflected by the recording medium P is a circle with a diameter of about 3 mm. A detection signal (analog signal) of the reflected light 604 is transmitted through a flexible cable (not shown) to a control circuit on an electrical board of the recording apparatus, and converted into a digital signal by an A/D converter in the control circuit. .

When measuring the coloring characteristics of an adjustment pattern for landing position adjustment, which will be described later, the conveyance of the recording medium P in the sub-scanning direction and the movement of the carriage unit 102 to which the reflective optical sensor 107 is attached in the main scanning direction are alternated. will be implemented. As a result, the reflective optical sensor 107 detects the density of the adjustment pattern recorded on the recording medium P as an optical reflectance in synchronization with the timing based on the position signal obtained by the encoder 106 .

When the adjustment pattern formed on the surface of the recording medium is irradiated with light, the level of reflection intensity reflecting the density of the adjustment pattern can be detected. The reflection intensity becomes stronger on the white recording medium surface, and the reflection intensity becomes weaker as the density of the adjustment pattern increases. The fluorescent ink emits fluorescent light, and the reflective optical sensor 107 shown in FIG. value becomes smaller.

For this reason, the influence of sensor reading errors increases, and it is difficult to perform registration adjustment using the fine adjustment density method for detecting density changes. However, the coarse adjustment distance detection method detects the boundary position where the read signal value of the paper white portion and the read signal value of the patch portion are switched. Therefore, since the reflective optical sensor 107 shown in FIG. 6(a) receives light of all wavelengths including the light-emitting region, a sufficient S/N ratio can be ensured even in the read signal value of the sensor. For the registration adjustment of the fluorescent ink, the processing described in S1501, S1502, and S1503 in FIG. 17 of Japanese Patent Application Laid-Open No. 2013-240991 is performed.

For fluorescent ink that is visually resistant to unevenness in impact variation, it is possible to perform registration adjustment only by the coarse adjustment distance detection method. On the other hand, since non-fluorescent ink is not affected by light emission, the distance detection method for coarse adjustment is performed, and then the density method for fine adjustment is performed. Perform the described processing. Further, in the registration adjustment for non-fluorescent ink, even-odd row correction and AB row correction between nozzle rows with a relatively small amount of print position deviation may be performed only by the fine adjustment density method. .

<First embodiment>
Next, the kogation suppression control according to the first embodiment will be described with reference to the flowchart of FIG. The processing shown in FIG. 7 is realized by the CPU 401 of the controller 400 developing a program stored in the ROM 402 in the RAM 403 and executing the program.

Upon receiving print data from the host device 404 via the IF 405, the controller 400 controls the conveying motor to feed the print medium in S701, and performs a print operation for one scan in S702. In the printing operation, printing ejection, which is ejection involved in printing an image, is performed. Subsequently, the controller 400 advances the process to S703, and determines whether the timer A, which indicates the length of time during which preliminary ejection is not performed, exceeds the threshold value Ath. For example, the threshold Ath may be 1 second. If the timer A exceeds the threshold Ath (Yes in S703), the controller 400 advances the process to S704. If not (No in S703), the process proceeds to S705. Subsequently, in S704, the controller 400 turns ON the preliminary ejection flag. In S705, the controller 400 determines whether or not the preliminary ejection flag is ON. If the preliminary ejection flag is ON (Yes in S705), the controller 400 advances the process to S706. If the preliminary ejection flag is not ON (No in S705), the controller 400 advances the process to S708. In S706, the controller 400 controls the print head 105 to perform preliminary ejection, and advances the process to S707. Preliminary ejection is, for example, performing ejection that does not involve printing less than 20 times within a page.

In S707, since the preliminary ejection has been performed in S706, the counter B indicating the number of times of preliminary ejection is added by B=B+1, the preliminary ejection flag is set to OFF, and the timer A is reset. In S708, it is determined whether or not the recording is completed. If the printing has ended, the process proceeds to S709. If the printing has not ended, that is, if there is still an image to be printed, the controller 400 returns the process to S702 and prints for one scan. Subsequently, the controller 400 advances the process to S709 and discharges the recording paper.

As described above, it is possible to maintain a good state at all times even if there is no printed image by periodically performing preliminary ejection while performing printing scans, and to output images without problems when a printed image appears during printing scanning. becomes.

Here, deposition of burnt deposits of ink containing fine resin particles will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 is a schematic diagram showing the state of the ejection heater 300 when ink containing fine resin particles is ejected.

A feature of the ink containing fine resin particles, such as the fluorescent ink of the ejection port array 205, is that the fine resin particles themselves may be partially destabilized due to the thermal shock caused by foaming or defoaming caused by driving the ejection heater 300. .

At this time, as indicated by 801, destabilized resin fine particles may bond together, or the resin fine particles may adhere to the heater. On the other hand, even if the fine resin particles adhere to the heater, the fine resin particles may be detached as shown in 802 due to the thermal shock when defoaming due to ejection. It is possible to repeat the detachment and discharge while maintaining a constant equilibrium state.

On the other hand, FIG. 9 is a schematic diagram showing the state of the ejection heater 300 when ink containing fine resin particles is only pre-ejected. For example, when an image of the fluorescent ink 45 is not included in the recorded image, the fluorescent ink 45 is not discharged during recording, so the discharge heater 300 corresponding to the fluorescent ink 45 performs only preliminary discharge. Preliminary ejection is control for ejecting ink in order to suppress drying of the ink, and a smaller amount of ink is ejected compared to normal ejection. In this embodiment, 10 shots are used. Since a relatively small amount of ink is ejected in the preliminary ejection, the thermal impact during defoaming caused by the ejection is small, and the effect of detachment of the fine resin particles on the heater is smaller than that in the recording ejection.

For this reason, when ink containing fine resin particles is not ejected during printing and a small amount of preliminary ejection is repeated, the fine resin particles themselves adhere during the rest period of the recorded image, and the fine resin particles are separated by only a small amount of preliminary ejection. less chance to do so. Therefore, as shown in FIG. 9, the fine resin particles may gradually adhere to the discharge heater 300 and deposit as kogation 901 . When the kogation accumulates, the kogation impairs the energy during ejection, and the energy for ejecting the ink is weakened.

Therefore, in the present embodiment, the degree of accumulation of kogation is estimated by counting the number of times preliminary ejection is performed, and recovery processing is performed when the number of times preliminary ejection is performed exceeds a threshold value. The recovery process is, for example, continuous ejection to the cap 108 a plurality of times, such as 1000 times or more, for example, 10000 times, after the end of printing. The recovery process may include aspiration of the nozzles by the cap 108 and may include wiping. The recovery process promotes detachment of the fine resin particles, reduces kogation accumulation, and makes it possible to restore the equilibrium state as shown in FIG. Therefore, in S710, it is determined whether or not the counter B indicating the number of times preliminary ejection is performed exceeds the threshold value Bth. Here, Bth is assumed to be 10000 times.

If the counter B exceeds the threshold Bth, the process proceeds to S111. If not, terminate.

In S711, recovery processing of the printhead 105 after printing is executed. In the recovery process, as described above, 10,000 shots of ink are continuously ejected, thereby further promoting the detachment of the kogation. At S712, the counter B is reset and the process ends. As described above, in a printing apparatus equipped with ink containing resin fine particles, the accumulation of burnt deposits due to resin fine particles is estimated based on the number of times preliminary ejection is performed, and the accumulation of burnt deposits due to the resin fine particles is suppressed by periodically executing recovery processing. becomes possible.

<Second embodiment>
In the first embodiment, when the number of times of preliminary ejection exceeds the threshold value, recovery processing is uniformly performed after printing is completed regardless of the printing ejection. However, when the recorded image includes an image of ink containing fine resin particles, the kogation can be separated by the recording ejection, so it is possible to suppress the accumulation of the kogation. In the second embodiment, control for executing a recovery operation after printing is further based on the number of ejections in printing will be described. The same reference numerals are used for the same configurations, processes, and functions as in the first embodiment, and the description thereof is omitted.

Although FIG. 10 is a flow chart in the second embodiment, the processing of S1007 will be described in detail as a difference from the first embodiment.

In S1007, since the preliminary ejection was performed in S706, the controller 400 calculates the value C based on the number of ejections of the ejection heater 300 in printing ejection in addition to the counter B indicating the number of times of preliminary ejection, and turns off the preliminary ejection flag. and reset timer A.

Calculation of the value C based on the number of ejections in the recording ejection will be described with reference to the table of FIG.

The number of recorded shots in the table shown in FIG. 11 is calculated from the recorded data created by the process of FIG. For example, when performing one preliminary ejection for each printing scan (printing ejection), control is performed based on the numerical value of the average number of printing shots (average number of ejections) of one printing scan.

When the number of ejections in one printing scan is 3200000, since there are 1280 ejection openings for each row of the print head 105, ejection is performed an average of 2500 times. Similarly, when the number of ejections in one printing scan is 6,400,000, each ejection heater 300 performs an average of 5,000 ejections. Similarly, when the number of ejections in one printing scan is 12,800,000, each ejection heater 300 performs an average of 10,000 ejections. When the number of ejections is 0, the average number of ejections is 0.

When the average number of ejections in recording ejection is 0 times or more and less than 2500 times, kogation adheres and accumulates as in the first embodiment, so the value C=C+1. When the average number of ejections is 2500 times or more and less than 5000 times, the value C=C is set because the balance between the ejection during the printing scan and the detachment of the kogation is balanced. When the average number of ejections in printing ejection is 5000 times or more and less than 10000 times, the effect of removing kogation due to the ejection during printing scanning is obtained, and the degree of kogation deposition is reduced, so the value C=C-1. Therefore, the value C can take negative values.

If the average number of ejections in printing ejection is 10000 times or more, it means that the number of ejections during printing scanning is the same as the number of continuous ejections in the recovery process of S111 of the first embodiment. That is, when the average number of ejections in one recording ejection is 10000 times, the same kogation reducing effect as the recovery process after the printing in the first embodiment is obtained. Therefore, assuming that the same kogation reduction effect as that of resetting the counter B in S712 has already been obtained, the counter B is reset and the value C=0.

If it is determined in S1010 that the sum of the counter B and the value C exceeds the threshold value Bth, the process advances to S711 to execute the recovery process after the end of recording. Subsequently, in S1012, a value C determined based on the number of times B of preliminary ejection and the number of times of ejection of the printing scan is reset to zero.

As described above, the degree of kogation deposition can be determined more accurately by considering both the kogation reduction effect according to the number of ejections in one recording ejection and the kogation accumulation effect according to the preliminary ejection. can be estimated and the recovery process can be performed at the appropriate time.

<Other Examples>
As another example, control for performing recovery processing after the end of printing in this embodiment based on the result of an ink ejection test will be described. In this embodiment, the recording apparatus 1 is provided with an ejection detection unit 450 as an optical sensor for determining whether or not ink has been ejected. As shown in FIG. 12, the ejection detection unit 450 includes a light emitting element 1201 and a light receiving element 1202 arranged at a position away from the ejection port for detecting the ink ejection state.

The ejection detection unit 450 is provided below the carriage scanning, and ejects ink after the carriage moves above the sensor. The ejection detection unit 450 determines that the output of the light emitting element 1201 is constant, and that the light is ejected when the intensity of the light received by the light receiving element 1202 changes, and that the ink is not ejected if it does not change. For example, it may be determined that ink is ejected when the intensity of light received by the light receiving element 1202 is smaller than a predetermined threshold, and that ink is not ejected when it is greater than or equal to the predetermined threshold.

In the case of ink containing fine resin particles, when the ejection speed of the ink decreases due to the accumulation of kogation, the ink droplets may not reach the detection range of the ejection detection unit 450, and the detection result is non-ejection. may be judged.

Hereinafter, the control for performing recovery after printing according to the present embodiment based on the ejection test result of ink containing fine resin particles will be described with reference to the flowchart of FIG. 13 .

In S1301, an ejection inspection is performed. The ejection inspection is performed periodically after printing or when the user selects cleaning. In one example, it may be determined whether or not the ink ejected in the preliminary ejection is detected while the printing apparatus 1 is performing the preliminary ejection.

In S1301, the number of nozzles determined to be non-ejection by the ejection detection unit 450 is counted as the number N of non-ejection nozzles. For example, ink containing fine resin particles is ejected from each of the ink ejection openings 200 in order, and the number of ejections detected by the ejection detection unit 450 is subtracted from the total number of ink ejection openings containing fine resin particles. The non-ejection number N can be counted.

It is determined whether or not the number N of ejection openings 200 for which ejection could not be detected, ie, was determined to be non-ejecting even though ejection was performed in S1302, exceeds a threshold value Nth. Assume that the threshold value Nth is 10 here. If the number N of ejection ports 200 determined to be non-ejecting exceeds the threshold value Nth (Yes in S1302), the process proceeds to S1303, and if not (No in S1302), the process ends. Recovery processing is performed in S1303. For example, in S1303, nozzle suction is performed. Even if the liquid chambers and nozzles are not filled with ink, the ink is supplied by this operation to fill the liquid chambers and nozzles with ink, and the ejection ports can be recovered. Further, in S1303, continuous ejection may be performed. As a result, even when kogation is accumulated due to the resin fine particles, it is possible to promote detachment of the kogation and reduce the kogation accumulation. Also, in S1303, wiping is performed. As a result, even if paper dust or the like adheres to the surface of the print head 105 and obstructs the ejection, the paper dust is removed and the ejection speed can be recovered.

As described above, it is determined whether or not ejection has been detected in the ink containing fine resin particles, and if it is determined that ejection has not occurred, recovery processing is performed, thereby improving the ejection failure of the printing element. can do.

Note that the process shown in FIG. 13 can also be applied to an ejection element that ejects ink that does not contain fine resin particles. In this case, in S1303, nozzle suction and wiping are performed, but the type of recovery processing may be changed depending on the ink to be ejected, such as not performing continuous ejection. This allows the controller 400 to execute recovery processing according to the type of ink.

In the present embodiment, the ink is ejected while the print head scans in the width direction. However, in one example, a print head having a length longer than the width direction of the print medium is used, and an image is printed by ejecting ink from the print head while conveying the print medium only once in a direction crossing the width direction. It can also be applied to any recording device.

Further, as another embodiment, according to the temperature of the printing apparatus during printing, for example, the higher the temperature is, the more the number of ejections in the recovery process after the end of printing is increased, or control is performed so that preliminary ejection after the end of printing is frequently performed. You may For example, the controller 400 appropriately controls the threshold Ath corresponding to the execution period of preliminary ejection, the threshold Bth of the number of preliminary ejections, and the value C corresponding to the number of ejections in the printing ejection in S1007 according to the output of the temperature sensor 413. You can change it. That is, the controller 400 may execute the recovery process more frequently according to the temperature measured by the temperature sensor 413, or may set the contents of the recovery process.

In another embodiment, the controller 400 acquires the execution interval of the recovery process according to the length of time during which the recovery process is not executed. The control may be changed so that the recovery process is entered frequently.

As another embodiment, as the cumulative number of ejections of the print head increases, the number of ejections in the recovery process may be increased, or the control may be changed so that the recovery process is frequently performed.

Further, in the present embodiment, the content concentration of the resin fine particles is 5%. However, in order to obtain a dark ink, there is a case where the concentration of resin fine particles is set to a high concentration such as 10%. In this case, the destabilization of the fine resin particles may further progress due to foaming due to driving of the ejection heater 300 during ejection or thermal shock during defoaming. Therefore, depending on the content concentration of the resin fine particles, the control may be changed to increase the number of discharge times in the recovery process or to perform the recovery process more frequently as the concentration becomes higher.

Further, in the present embodiment, the recovery process is performed after the printing operation is completed when the number of times of preliminary ejection is equal to or greater than the predetermined number of times. However, in one example, recovery processing may be performed after performing one scan, recovery processing may be performed after printing on one printing medium is completed, or recovery processing may be performed after one printing job is completed. processing may be performed.

The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus reads and executes the program. It can also be realized by processing to It can also be implemented by a circuit (for example, ASIC) that implements one or more functions.

The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the claims are appended to make public the scope of the invention.

102: carriage, 105: recording head, 300: recording element, 400: controller

Claims (25)

A recording device,
a recording head that ejects ink onto a recording medium;
preliminary ejection control means for causing the recording head to perform preliminary ejection;
recovery control means for performing recovery processing of the print head according to the number of times the preliminary ejection is performed;
A recording device comprising: 2. A printing apparatus according to claim 1, wherein said recovery processing includes an operation of ejecting ink from said printhead. 2. A recording apparatus according to claim 1, wherein said recovery processing includes an operation of ejecting ink from said recording head a plurality of times in succession. further comprising a cap that covers the recording head and sucks ink ejected from the recording head;
4. A printing apparatus according to claim 2, wherein said recovery processing includes an operation of ejecting ink from said print head to said cap. 5. A recording apparatus according to claim 1, wherein said ink contains a resin component. 6. A recording apparatus according to claim 1, wherein said recovery control means performs said recovery processing after finishing a recording operation. 7. A recording apparatus according to claim 6, wherein the end of the recording operation is after the end of recording on one recording medium. 7. A printing apparatus according to claim 6, wherein the end of the printing operation is after one printing job is completed. 9. The print head comprises a plurality of ejection elements, and the recovery control means causes the print head to perform recovery processing in accordance with the number of times of preliminary ejection for each of the plurality of ejection elements. The recording apparatus according to any one of 1. 10. A printing apparatus according to claim 1, wherein said recovery control means controls said print head so as to perform said recovery process each time said number of times of preliminary ejection reaches a predetermined number of times. . 10. A method according to any one of claims 1 to 9, wherein said recovery control means controls said print head so as to perform said recovery process based on said number of times of preliminary ejection and said number of times of ejection in a printing operation. recording device. The recovery control means controls the print head to perform the recovery process when the sum of the number of times of preliminary ejection and a value determined for each range of the number of times of ejection in the printing operation exceeds a predetermined number of times. 12. The recording apparatus according to claim 11, wherein: The value is the first value when the number of ejections in the printing operation is within the first range, and the first value when the number of ejections is within the range of the second number greater than the first range. 13. A recording apparatus according to claim 12, wherein the second value is less than . 14. A printing apparatus according to claim 13, wherein said recovery control means resets the number of times of preliminary ejection to 0 when the number of times of ejection in said printing operation is greater than the range of said second number of times. 15. A recording apparatus according to claim 1, wherein said recovery control means resets the number of times of preliminary ejection to 0 when said recovery processing is performed. 2. The preliminary ejection control means controls the printhead to perform the preliminary ejection when the time during which the preliminary ejection is not executed exceeds a predetermined time during the printing operation. 16. The recording apparatus according to any one of 15 to 15. 17. A recording apparatus according to claim 1, wherein said recording head comprises a heater that generates heat when a drive pulse is applied. a conveying means for conveying the recording medium;
scanning means for scanning the recording head in a direction crossing the conveying direction of the conveying means;
18. The recording apparatus according to any one of claims 1 to 17, further comprising: further comprising detecting means for detecting ink ejected from the recording head at a predetermined position away from the recording head;
19. The recording apparatus according to any one of claims 1 to 18, wherein said recovery control means determines whether or not to execute said recovery processing based on the detection result of said detection means. further comprising a temperature sensor for measuring the internal temperature of the recording device;
13. A recording apparatus according to claim 10, wherein said recovery control means sets said predetermined number of times to be smaller as the temperature measured by said temperature sensor is higher. further comprising a temperature sensor for measuring the internal temperature of the recording device;
5. A recording apparatus according to claim 2, wherein said recovery control means increases the number of ejections in said recovery process as the temperature measured by said temperature sensor increases. 13. The recording apparatus according to claim 10, wherein the recovery control means sets the predetermined number of times to be smaller as the recovery processing is not executed longer. 5. A recording apparatus according to claim 2, wherein said recovery control means increases the number of times of ejection in said recovery process as the time during which said recovery process is not executed increases. 13. The recording apparatus according to claim 10, wherein the recovery control means sets the predetermined number of times to be smaller as the concentration of the resin component contained in the ink is higher. 5. The recording apparatus according to claim 2, wherein said recovery control means increases the number of ejections in said recovery process as the concentration of the resin component contained in said ink is higher.

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