JP5252857B2 - Ink jet recording apparatus and control method of the recording apparatus - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and a control method for the recording apparatus, and more specifically, a plurality of nozzles arranged in a recording head are divided into a plurality of blocks, and the timing for driving the recording elements of the nozzles is shifted between the blocks. This relates to so-called time-division drive control.

  In recent years, with the widespread use of information equipment, recording devices, which are peripheral equipment, are also rapidly spreading. In particular, an ink jet recording method in which a recording head is scanned with respect to a recording medium and ink is ejected from the recording head at the time of scanning is easy to downsize the apparatus, and has a relatively simple configuration. It has various advantages such as being capable of color recording. From such a point, the ink jet recording method is adopted in many information output devices.

  Among ink jet recording apparatuses, the thermal ink jet method that ejects ink using bubbles generated by thermal energy is relatively easy to integrate the ejection mechanism relatively, and the ejection ports for ejecting ink are arranged at high density. Making it possible. By disposing the discharge ports at high density in this way, the recording head and thus the recording apparatus can be reduced in size, and high-quality and high-speed recording is possible.

  When ink is ejected by driving a recording head in which a large number of ejection ports are arranged in this way, a relatively large capacity power supply is required to eject all the ejection ports simultaneously and eject ink at the same timing. Is required. For this reason, a so-called time-division driving method is generally employed in which a plurality of ejection openings are divided into a plurality of blocks and sequentially driven for each block. By performing this time-division driving, the number of ejection ports that are driven simultaneously is reduced, so that the capacity of the power source required for the printing apparatus can be suppressed.

  By the way, depending on such a time-division driving method, various inconveniences may occur regarding the flow of ink in the recording head. For example, when ink is ejected from a certain ejection port, the pressure fluctuation generated at that time is transmitted to the adjacent ejection port through the ink flow path, and the ink interface (meniscus) of the ejection port becomes unstable. When ink is ejected in such an unstable state, the landing position of the ink on the recording medium may be shifted, or the amount of ink droplets ejected from the ejection port may vary. If the landing positions of the ink droplets are shifted or the ejection amount of the ink droplets is changed as described above, density unevenness may occur in the image on the recording medium. In addition, due to the deviation of the landing position, the ink dots formed on the recording medium are overlapped, and conversely, the recording medium is blanked, which may cause uneven density such as black stripes or white stripes.

  In order to solve the discharge failure due to the ink meniscus state as described above, the level of negative pressure generated in the liquid chamber is optimized by optimizing the timing and discharge amount of time-division drive during ink discharge. There is known a method of bringing the distance close to (see Patent Document 1). In this Patent Document 1, ink can be ejected in a stable state in which the amplitude of vibration during ink refilling is small by bringing the negative pressure generated in the liquid chamber close to normal pressure by optimal time-division driving. A technique for improving the driving frequency is described.

Japanese Patent Laid-Open No. 05-084911

  However, even when time-division driving is performed in which the amplitude of ink refill vibration is reduced during recording, ink mist may adhere to the surface of the recording head on which the ejection openings are provided. As a result, the landing position deviation of the ejected ink droplets and the like occur, and density unevenness similar to that described above occurs.

  For example, during pre-discharge, in order to prevent uneven printing, especially density unevenness caused by the difference in discharge characteristics between used nozzles and non-used nozzles, the drive pulse can be controlled to the maximum discharge amount or There is also a known technology that uses large amounts of energy. In the case of preliminary ejection, it is common to eject many ink droplets at a high frequency from a plurality of ejection port arrays at a time. In such a case, the air current between the flying ink droplets interferes to generate a turbulent flow, and the ink mist wound up by the turbulent flow often adheres to the ejection port surface.

  In addition, a recording apparatus provided with an ink receiving portion for receiving the pre-discharged ink is known. The distance between the discharge port surface of the recording head and the receiving surface of the ink receiving portion is determined by the discharge port at the time of recording. It is often set larger than the distance between the surface and the recording medium. This prevents the discharge port surface of the recording head from inadvertently contacting with the receiving surface and rubbing, or pre-discharged ink from accumulating and contacting the discharge port surface. However, as a result, the amount of ink mist generated during preliminary ejection is larger than that during recording, and turbulent flow is likely to occur.

  As described above, when a large amount of ink mist adheres to the ejection port surface during preliminary ejection, it may be combined with the adhesion mist on the ejection port surface when ink is ejected during recording. As a result, the ejection direction changes and the landing position shifts, and there is a problem that density unevenness is caused in the recording as described above.

  The object of the present invention is to reduce the amount of ink mist adhering to the ejection port surface during preliminary ejection by devising the time-division driving method of the recording head, and to perform recording with high quality and high reliability. It is to provide a possible ink jet recording apparatus and a method for controlling the apparatus.

Therefore, in the present invention, in an inkjet recording apparatus that uses a recording head in which a plurality of ejection openings are arranged, and performs recording by ejecting ink onto a recording medium by performing time-division driving on the plurality of ejection openings from the recording head. In addition to the recording medium, the preliminary ejection means for performing preliminary ejection for ejecting ink not involved in recording from the recording head, and the operation of the recording head, the next recording operation is performed or the preliminary ejection by the preliminary ejection means is performed. A determination unit that determines whether or not preliminary ejection is performed, and d discharges of a group consisting of discharge ports adjacent to each other in the array having the same number d as the number of time divisions in time-division driving. The outlets are divided into n (an integer greater than or equal to 1) divided groups and are time-division driven, and are continuously arranged in the discharge port array of the k-th divided group (k = 1,..., N). The d / n number of discharge ports, ink sequentially from these discharge ports is discharged, and the first ejection order of the discharge port to be ejected in the k divided group initially discharged at the (k + 1) Split Group In this case, continuous time-division driving is performed that precedes the ejection order of the ejection ports to be performed, and when the determination unit determines that a recording operation is performed, ink is ejected in order from the d ejection ports of the group. And control means for performing distributed time division driving, which is time division driving other than the continuous time division driving,
It is characterized by comprising.

In another embodiment, a recording head having an ejection port array in which a plurality of ejection ports are arranged, and the ejection port array are divided into a plurality of groups for each of a plurality of continuous ejection ports, and time-division driving is performed for each group. An ink jet recording apparatus that performs recording by ejecting ink onto a recording medium, and the control means includes a control unit that performs pre-ejection that ejects ink not involved in recording. Are divided into a first divided group and a second divided group, and a plurality of outlets of each divided group are sequentially arranged from one side and discharged from the outlets of the first divided group and the second divided group. When performing the recording operation on the recording medium by controlling the discharge from the outlet alternately, the plurality of discharge ports in each group are changed to the meniscus of ink generated when the adjacent discharge ports are driven. And controls so as to drive the vibration in the driving order of the distance to be discharged in a state in which subsided.

Further, in a control method for an ink jet recording apparatus that uses a recording head in which a plurality of ejection openings are arranged and performs recording by ejecting ink onto a recording medium by performing time-division driving from the recording head to the plurality of ejection openings. In addition to the medium, a step of preparing preliminary ejection means for performing preliminary ejection for ejecting ink that does not participate in recording from the recording head, and the operation of the recording head, whether the recording operation is performed next or preliminary ejection by the preliminary ejection means A determination step for determining whether or not pre-discharge is performed, and when the determination step determines that preliminary discharge is performed, the number d is the same as the number of time divisions in time-division driving, and d The ejection ports are divided into n (an integer greater than or equal to 1) divided groups and time-division driven, and the ejection ports are arranged in the k-th divided group (k = 1,..., N). The continuous d / n number of discharge ports, ink sequentially from these discharge ports is discharged, and the discharge order of the discharge port is initially discharged at the k divided group is initially at the (k + 1) Split Group In this case, continuous time-division driving, which is ahead of the discharge order of the discharge ports discharged to the nozzle, is performed, and when the determination unit determines that the recording operation is performed, the ink is sequentially discharged from the d discharge ports of the group. And a control step of performing distributed time-division driving, which is time-division driving other than the continuous time-division driving.

  According to the above configuration, it is possible to perform continuous time-division driving with less mist generation during preliminary ejection. Further, during the preliminary ejection, the above-described continuous time-division driving is performed, while during recording, the dispersion-type time-division driving in which the displacement of the landing position or the like is smaller than the continuous-type time-division driving is performed. Thereby, it is possible to prevent the ink mist from adhering to the ejection port surface during preliminary ejection and to record a high-quality image.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an ink jet recording apparatus according to an embodiment of the present invention. In FIG. 1, an ink jet recording apparatus 1 includes a carriage 2 that can reciprocate in the main scanning direction indicated by an arrow A, and performs recording by ejecting ink from a recording head 3 that is detachably mounted on the carriage. An ink jet cartridge 4 that contains ink and supplies ink to the recording head 3 is detachably held with respect to the recording head 3. The inkjet cartridge 4 contains black (K) ink and cyan (C), light cyan (LC), magenta (M), light magenta (LM), and yellow (Y) color inks, respectively. The recording head 3 includes nozzle rows for discharging black ink (not shown) and five nozzle rows used for discharging each color ink. Each color ink nozzle row is formed by arranging 1280 ejection openings.

  The carriage 2 is guided by a guide shaft 8 attached to the housing 7 so as to be movable in the direction of the arrow A in the figure, that is, in the main scanning direction, and is included in the drive mechanism 5 that transmits the drive force of the CR motor M1. 6 is connected. Accordingly, the carriage 2 reciprocates along the guide shaft 8 by rotating the CR motor M1 forward or backward. Further, a scale (encoder) 9 indicating an absolute position of the carriage 2 in the main scanning direction is disposed in the housing 7 in parallel with the guide shaft 8.

  A paper feed mechanism 10 is provided on the back of the housing 7, and a plurality of recording media P of various sizes such as A4 size paper and postcard size paper are placed on a paper feed tray 11 included in the paper feed mechanism 10. It can be mounted. The paper feed mechanism 10 includes a separation roller (not shown) driven by an LF motor M2 (not shown in FIG. 1), and the recording medium P is fed from the paper feed tray 11 by the separation roller, and the print head on the carriage 2 3 is supplied (conveyed) to a recording position opposite to 3.

  Further, the ink jet recording apparatus 1 includes a recovery device 15 including a capping unit 13 and a wiping unit 14. When the inkjet recording apparatus 1 is not recording, the recording head 3 is capped by the capping unit 13. In this capping state, the suction recovery process is performed as part of the discharge recovery process. Ink adhering to the recording head 3 is removed by the wiping unit 14.

  An ink receiver (hereinafter referred to as a preliminary discharge box) that receives preliminary discharge ink, which will be described later with reference to FIG. 2, is disposed between the capping unit 13 and the recordable area (not shown in FIG. 1). As the carriage moves to this position, a discharge recovery process by preliminary discharge is performed.

  At the time of recording, the carriage 2 moves in the forward direction of the arrow A (for example, the moving direction from the home position side to the other end). Discharged. When the carriage 2 moves to the other end of the recording medium P, the separation roller rotates by a certain amount, thereby conveying the recording medium P by a predetermined amount in the direction of arrow B (sub-scanning direction, conveyance direction). Then, recording is performed while moving the carriage 2 again in the backward direction of the arrow A (for example, the moving direction from the other end to the home position side). In this way, an image is recorded on the entire recording medium by repeating the recording scan of the carriage and the conveying operation of the recording medium.

  The recording head 3 includes a heating resistor element for converting electrical energy into thermal energy. The ink is caused to boil by the heat energy generated by the heating resistor element, and the ink is ejected by utilizing the pressure change caused by the growth and contraction of bubbles due to the film boiling. The heating resistance elements are provided in the respective ejection openings (also referred to as nozzles) constituting the nozzle row of each color ink, and a driving pulse voltage is applied to each heating resistance element in order to eject ink.

FIG. 2 is a diagram schematically showing a configuration of a preliminary discharge box used in the recording apparatus of the present embodiment shown in FIG. The recording medium P is supplied onto the platen 17, and normally the distance between the recording medium P and the recording head 3 is set as close as possible. On the other hand, the preliminary discharge box 16 disposed between the capping unit 13 and the recordable area usually has a relatively large distance from the recording head 3. This is to prevent dirt and by the preliminary ejection ink to the recording area, ink deposit by the preliminary ejection Ru rubbing the recording head. An absorber for receiving the preliminary discharge ink is disposed in the preliminary discharge box.

  FIG. 3 is a block diagram showing a control configuration in the ink jet recording apparatus shown in FIG. The ink jet recording apparatus according to the present embodiment is connected to a host computer (such as a PC) and can record image data including image information and recording information created by using an application of the host computer. In FIG. 3, reference numeral 200 denotes a CPU that controls the entire inkjet recording apparatus. The CPU 200 executes processing described later with reference to FIG. 9 using programs and data stored in the ROM 201 and random access memory (RAM) 202. That is, the CPU 200 controls the recording apparatus by sending a drive command to each drive unit via the main bus line 205. An image input unit 203 and an image signal processing unit 204 are connected to the main bus line 205, and image information (image data) from the host computer is temporarily input to the image input unit 203 and then input to the image signal processing unit 204. And converted into an image signal (recording data) suitable for recording. The main bus line 205 is further connected to an operation unit 206 for performing various settings relating to recording by an operator and a recovery system control circuit 207 connected to a recovery device for the recording head. Furthermore, the main bus line 205 is connected to a head drive control circuit 215, a carriage drive control circuit 216, and a paper feed (conveyance) control circuit 217, which are each drive unit. In addition, a program for driving each drive unit is stored in the RAM 202 in advance, and the program for each drive circuit is activated in accordance with a drive command from the CPU 200.

  The recording apparatus is connected to a host computer via an interface connected to the main bus. In the above description, the host computer and the recording apparatus are connected. However, in addition to the host computer, a digital camera or a flash memory can be connected. At this time, the recording device records an image captured by the digital camera or an image stored in the flash memory.

  The recovery system control circuit 207 is a circuit that controls a recovery device for maintaining a good discharge state of ink droplets from the recording head, and controls the drive of the recovery system motor 208, the blade 209, the cap 210, and the suction pump 211. . The recovery device includes a blade 209 that wipes off ink droplets and dust adhering to the ejection port surface, and a cap 210 that covers the ejection port surface when recording is not performed so that ink does not evaporate from the ejection port. Further, there is a suction pump 211 that suctions ink in the recording head by forcing a negative pressure in the cap and forcibly discharges the thickened ink in the nozzle.

  The recording head drive control circuit 215 drives the heating resistance element of the recording head 213 according to the recording data. As a result, the recording head 213 can perform so-called preliminary ejection for ejecting ink that is not involved in recording from the recording head other than the recording medium, ink ejection for image recording, and temperature control of the ink or the recording head. Further, a carriage drive control circuit 216 that controls the drive of the carriage, a paper feed control circuit 217 that controls a paper feed mechanism that feeds and transports the recording medium, and the like respectively drive the carriage motor and the carry motor according to the drive program. .

  4A to 4C are diagrams for explaining an example of time-division driving, in which FIG. 4A is a nozzle row of a recording head, FIG. 4B is a drive signal applied to each nozzle, FIG. 4C schematically shows the flying ink droplets ejected from each nozzle by the drive signal.

  In FIG. 4A, the nozzle array 500 of the ink jet recording head is composed of, for example, 32 nozzles, and these nozzles are divided into four groups from the first group to the fourth group, 8 nozzles from the top in the figure. It has been. Further, each of the eight nozzles in each group belongs to one of the eight drive blocks, and is driven sequentially in a time-division manner in units of blocks when recording. In time-division driving, the nozzles in the same block are driven simultaneously. In the illustrated example, the four nozzles No. 1, 9, No. 17, and No. 25 in the nozzle row are the first drive block (also simply referred to as the first block), No. 8, No. 16, No. 24, and No. 32. One nozzle is the second drive block. Similarly, the nozzles in each group are periodically assigned to each drive block such that the second, tenth, 18th, and 26th nozzles are called the eighth drive block. In the case of time-division driving sequentially driven from the first drive block to the eighth drive block in ascending order, the respective heating resistance elements are sequentially driven by the pulse-like drive signal 300 shown in FIG. Corresponding to FIG. 4, the ink droplet 100 is ejected as shown in FIG.

  Next, a block configuration of time division driving of the recording head and a drive signal to be applied according to an embodiment of the present invention will be described with reference to FIGS. 5 and 6 are diagrams showing “continuous” time-division driving and “distributed” time-division driving, respectively. In the embodiment of the present invention, the time-division driving is switched between preliminary ejection and recording.

  In the continuous time-division driving shown in FIG. 5, the nozzle row (discharge port arrangement) in which 1280 nozzles are arranged for each ink color is grouped into 20 nozzles. No. 0 nozzle to No. 19 nozzle are the first group, and thereafter the nozzle array is divided into 64 groups in the same manner. The number of blocks (number of time divisions) recorded per unit time is 20. For example, the No. 0, No. 20... Nozzles have a block No (number) of 0, and 64 nozzles of the same block No. are simultaneously driven to eject ink. Although the 20 nozzles in this group are sequentially driven, they are all driven within one column (one cycle). Note that the print head of this embodiment has a nozzle row configuration in which 1280 nozzles are arranged in one row, but a print head in which nozzle rows of 640 nozzles are shifted by two rows may be used. At this time, the nozzles of the odd and even rows are arranged so as to be shifted in the main scanning direction. For each nozzle row of the odd and even rows, one group can be constituted by 20 continuous nozzles, and the nozzles of each group can be block-driven for each nozzle row.

The continuous time-division driving shown in FIG. 5 is sequentially driven from the upper nozzle to the lower nozzle with one drive timing. For example, when ink is ejected from all nozzles, first, the nozzle No. 0 is driven and ink is ejected from the nozzle No. 0. Next, ink is sequentially ejected from the 10th nozzle, 1st nozzle, 11th nozzle,. In the example shown in FIG. 5, the drive in which the drive timing is continuous is not actually performed from the adjacent nozzles in the array. However, in the divided group of nozzles 0 to 9 (hereinafter referred to as the first divided group) that are continuous in the nozzle arrangement, ink is ejected in order from these nozzles. 10th nozzle to 19 th divided groups of nozzles (hereinafter, a second split group) The same applies. The ejection order of the nozzles ejected first in the first divided group is ahead of the ejection order of the nozzles ejected first in the second divided group. In this specification, this driving order is referred to as a “continuous” driving order. Of course, as shown in FIG. 8, the continuous drive order includes driving the adjacent nozzles in one group related to the time-division drive from the 0th nozzle to the 19th nozzle in order.

Generally speaking, when the number of adjacent nozzles in the array is the same as the number of time-division drive blocks (time-division number d; 20 in FIG. 5), n nozzles (1 Consider time division driving by dividing into the above integers (two in FIG. 5). At this time, the driving sequence of “continuous type” is d / n continuous in the nozzle arrangement of the k-th divided group (k = 1,..., N; first and second divided groups in FIG. 5). In the nozzles, ink is ejected in order from these nozzles. The ejection order of the nozzles ejected first in the k-th divided group is ahead of the ejection order of the nozzles ejected first in the (k + 1) -th divided group.

  According to the above-described continuous driving order, it is possible to suppress the generation of ink mist and reduce the amount of mist adhering to the discharge port surface. That is, conventionally, when ink is ejected sequentially from adjacent nozzles, the ink meniscus of the adjacent nozzles is vibrated during ink ejection, and the ink ejection from the adjacent nozzles becomes unstable (crosstalk). It has been. However, the inventors of the present invention do not generate airflow due to flying ink droplets by performing time-division driving in the above driving sequence even when ink is ejected in this unstable state. Found to be suppressed. This is because the energy of bubbles due to film boiling diffuses due to crosstalk, so that the speed of ink discharge decreases and airflow is reduced. As a result, not only the amount of ink mist generated can be reduced, but also the turbulence can be prevented from interfering with the airflow between the flying ink droplets. Adhesion can also be suppressed.

  However, since the ejection characteristics are relatively unstable, the position where the ink droplets land on the recording medium may be shifted, or the amount of ink droplets ejected from the ejection port may vary. For this reason, in the embodiment of the present invention, such time division driving is used at the time of preliminary ejection. Thereby, it is possible to reduce the ink mist from adhering to the ejection port surface due to the preliminary ejection.

  For example, since the nozzle that is ejected first in each group of time-division driving is not affected by crosstalk, the speed of ejected ink is high and airflow is also generated. After that, the ink droplets ejected continuously are affected by the crosstalk, the ejection speed is reduced, and the airflow is also reduced. The landing position of the ink droplet to be moved will be twisted. Out of the continuously ejected ink droplets, the landing position of an ink droplet located relatively behind is referred to as end deflection. In the example shown in FIG. 5, when the number of ejections per unit time is large, the ink droplets of the 1st nozzle and the 11th nozzle are affected by the airflow generated by the ejection of continuous ink droplets, respectively. It is drawn toward the 10th nozzle. This edge misalignment causes a white streak-like line in which the ground color of the recording medium can be seen in the image by shifting the landing position of the portion corresponding to one end of the belt-like image recorded by continuously ejected ink droplets. End up. The white streak-like lines are generated for each group during continuous time-division driving of the recording head, and thus the white streak intervals are very narrow, that is, many are generated at a low pitch. Therefore, it is easily recognized and leads to a decrease in image quality. This white streak occurs when a high duty image, a high duty recorded in one recording scan, a large amount of ink applied per unit area, a large number of ejections per unit time, etc. It appears more prominently when recorded under conditions.

  On the other hand, in the present embodiment, the “distributed” driving order shown in FIG. 6 is used in a normal recording operation. This makes it possible to perform high-quality and highly reliable recording without any landing position deviation.

  That is, the time-division driving shown in FIG. 6 shows an example based on the distributed driving order. In FIG. 6, the group and block configurations are the same as those in FIG. In this specification, as shown in FIG. 6, ink is ejected in order (time division) from 20 nozzles in one group, but the drive order other than the above-described continuous time division drive is used. This is called “distributed” driving order. As shown in FIG. 6, in the distributed drive, when ink is ejected from all nozzles, first, nozzle No. 0 is driven and ink is ejected from nozzle No. 0, then nozzles No. 8, nozzle No. 4, Ink is sequentially ejected from the 12th nozzle.

  Conventionally, when ink is ejected from nozzles that are not adjacent to each other at different drive timings, it is known that the ink meniscus of the nozzle does not vibrate and ink is ejected in a stable state. In other words, when ink is ejected from a nozzle, the ink interface between adjacent nozzles vibrates, but it is thought that stable ink ejection is performed by ejecting ink from a remote nozzle with a stable ink interface. It has been. Then, it is considered that the ink is ejected after the vibration of the ink interface due to the ink ejection of the adjacent nozzles is settled. However, the inventors of the present invention have discovered that when ink is ejected in this stable state, the generation of airflow due to the flying of ink droplets is promoted. That is, since the energy of bubbles due to film boiling is accurately transmitted to the ejected ink, the ink ejection speed is high and airflow is likely to occur. As a result, not only the amount of ink mist generated increases, but also the airflow between the flying ink droplets interferes to generate turbulent flow, causing the ink mist to adhere to the ejection port surface.

  However, since ink is ejected in a relatively stable state, there is little concern that the position where the ink droplets land on the recording medium will be shifted or the amount of ink droplets ejected from the ejection port will fluctuate. For example, the influence of the air flow generated by the previously ejected ink droplets is limited to the adjacent nozzle region, and it is difficult to exert the influence when the nozzle to be ejected next is separated. Therefore, when recording a high duty image, the distributed driving order is less likely to cause end deviation, so that a higher quality image can be recorded.

  As described above, in the present embodiment, a plurality of types of block drive orders as shown in FIG. 7 are prepared, and the continuous drive order is preliminary ejection, and the distributed drive order is image recording. Control to select each. In FIG. 7, the driving order A is the continuous driving order shown in FIG. 5, and the driving order B is the distributed driving order shown in FIG. Accordingly, it is possible to avoid selecting the driving order A that is worried about end deviation during image recording, and to achieve high-quality image recording by selecting the driving order B. In that case, although there is a concern that the ink mist adheres to the ejection port surface when the driving order B is selected, the distance between the ejection port surface of the recording head and the recording medium is normally set as close as possible. In many cases, the amount of ink mist generated is relatively small. The driving order C is the continuous driving order shown in FIG.

  On the other hand, since the distance between the preliminary discharge box and the discharge port surface is often relatively large, there is a concern that ink mist adheres to the discharge port surface during preliminary discharge. Also, during preliminary ejection, it is common to eject many ink droplets from a plurality of ejection port arrays at a high frequency at a time. In order to avoid such a concern, a reliable driving order A is selected during preliminary ejection. It is possible. In this case, although there is a concern about image deterioration such as edge deviation, it is not necessary to be aware of image deterioration if the driving order is limited to only preliminary ejection, so that an optimal driving order can be selected.

  FIG. 9 is a flowchart showing a control process of the ink jet recording apparatus according to the present embodiment.

  First, when image information (image data) is input from a host computer or the like, the image information is temporarily input to the image input unit (S101) and converted into an image signal (record data) suitable for recording by the image signal processing unit (S101). S102). In response to the input of the image information, the CPU 200 executes a block drive order selection sequence (S103). When the block driving order for the pre-printing recovery sequence is selected, after performing the preliminary ejection included in the pre-printing recovery sequence (S104), the recording operation is started (S105). When the printing operation is started, first, a block drive order selection sequence is executed (S106), and then preliminary ejection is performed during the printing operation. Next, after executing the block drive order selection sequence again (S108), a recording scan for performing image recording is performed (S109). When the recording scan of one scan is finished, it is determined whether or not the print job is finished (S110). If it is not finished yet, the process returns to S106 to start the recording operation. When the print job is completed, the recovery sequence at the end of printing is performed after the block drive order selection sequence is executed, and the preliminary ejection included in the recovery sequence at the end of printing is performed according to the selected drive order ( S112). When the recovery sequence at the end of printing ends, the recording head is capped (S113), and the printing operation ends.

  FIG. 10 is a flowchart showing processing for setting the block drive order in this embodiment. This process is a process executed in the block drive order selection sequence in the process of FIG.

  First, the CPU 200 acquires an operation status indicating whether the recording operation is being performed or the non-recording operation is being performed (S810). Based on the acquired data, it is determined whether or not to perform the preliminary ejection operation next (S820). If it is determined that the situation acquired in step S810 is the non-printing operation and the next preliminary ejection is performed, or if it is determined that the recording operation is being performed and the preliminary ejection is performed next, the subsequent step In S830, the block drive order is set as drive order A. Also, if the situation acquired in S810 is the recording operation and it is determined that the recording operation is to be continued next, the block driving order is set as the driving order B in S840. Next, in step S850, the ejection operation is executed in accordance with the driving order set in steps S830 and 840.

  As described above, according to the present embodiment, the block drive order is changed between the image recording and the preliminary ejection operation. Accordingly, it is possible to avoid selecting a driving order that is worried about end deviation at the time of image recording, and to select a driving order that may cause ink mist to adhere to the ejection port surface during preliminary ejection. That is, it is possible to perform recording without any deviation of the landing position during recording, and it is possible to perform ink ejection with less ink mist during preliminary ejection. Both high-quality image recording and improved reliability can be achieved.

(Other embodiments)
In the above-described embodiment, one driving order is selected as the block driving order at the time of preliminary ejection. However, a configuration in which the driving order can be selected according to the preliminary ejection conditions may be employed. Specifically, as a condition for preliminary ejection, the carriage moves to the preliminary ejection box during non-printing and then stops, and the preliminary ejection that is executed in that state (stationary preliminary ejection) and the carriage on the preliminary ejection box during the recording operation And preliminary discharge (moving preliminary discharge) that is performed while moving. In such a case, a different driving order may be selected.

  For example, in general, stationary preliminary ejection often ejects a large number of ink droplets at a high frequency from a plurality of ejection port arrays. Therefore, in order to suppress the airflow of ink droplets, the adjacent nozzles do not discharge sequentially in sequence as shown in FIG. 5, but the timing at which another nozzle discharges while the adjacent nozzle discharges is set. It may be better to provide (first continuous driving sequence). On the other hand, the moving preliminary discharge is often discharged sequentially at a relatively low frequency. For this reason, in order to suppress the air flow of ink droplets, the timing (corresponding to the driving order C in FIG. 7; the second continuous type) such that the adjacent nozzles as shown in FIG. It is preferable to optimize the driving order). That is, it is possible to maintain a more reliable state by appropriately selecting the optimum preliminary ejection block drive timing in accordance with the configuration of the head and the preliminary ejection conditions.

  FIG. 11 is a flowchart showing a process of grasping the operation status of the recording head and selecting an optimum block driving order for image recording, stationary preliminary ejection, and moving preliminary ejection. First, the CPU 200 obtains the operation status (S815), and determines whether the recording operation is being performed or the non-recording operation is being performed (S825). If the determination result is during the non-recording operation, the driving order A is set as the block driving order for stationary preliminary ejection included in the recovery sequence before printing or the recovery sequence at the end of printing (S865). If the determination result is during the recording operation, it is determined whether or not the preliminary ejection operation is to be performed next (S835). If the result of determination in S825 is that the printing operation is being performed and it is determined that preliminary ejection is to be executed next, then in block S845, the block driving order for moving preliminary ejection is determined (the division number n is the driving order A). (Less than) drive order C is set. If it is determined that the result of the determination in S825 is the printing operation and it is determined that the preliminary ejection operation is not performed next, the driving sequence B is set as the block driving sequence for recording in the subsequent S855. Next, in S875, the ejection operation is executed in accordance with the driving order set in S845, 855, and 865.

  As described above, according to the present embodiment, the block drive order can be switched between the image recording and the preliminary ejection operation, and the preliminary ejection block order can be selected according to the preliminary ejection conditions. As a result, it is possible to control the discharge timing optimum for the conditions of the preliminary discharge operation, and it is possible to perform image recording with higher reliability.

1 is a perspective view showing an ink jet recording apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the structure of the preliminary discharge box in embodiment of this invention. It is a block diagram which shows the electric constitution of an inkjet recording device. It is a schematic diagram which shows the drive signal in a time division drive, and the discharged ink droplet. It is a schematic diagram which shows the continuous time division drive order in embodiment of this invention. It is a schematic diagram which shows the distributed time division drive order in embodiment of this invention. It is a figure which shows the drive order of several time division drive. It is a schematic diagram which shows another continuous type time division drive order in embodiment of this invention. 6 is a flowchart illustrating a printing flow according to an embodiment of the present invention. It is a flowchart which sets the block drive order in embodiment of this invention. It is a flowchart which sets the block drive order in other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Carriage 3 Recording head 13 Cap 16 Preliminary discharge box 17 Platen 100 Ink droplet 200 CPU
215 Head drive control circuit 216 Carriage drive control circuit

Claims (10)

In an inkjet recording apparatus that uses a recording head in which a plurality of ejection openings are arranged and performs recording by ejecting ink onto a recording medium by performing time-division driving on the plurality of ejection openings from the recording head.
Preliminary ejection means for performing preliminary ejection for ejecting ink that is not involved in recording from the recording head other than the recording medium;
As a recording head operation, a determination unit that determines whether a recording operation is performed next or whether preliminary ejection is performed by the preliminary ejection unit;
When the determination unit determines that preliminary discharge is performed, the number of d discharge ports of a group consisting of adjacent discharge ports in the array, which is the same as the number of time divisions in the time division drive, is n (one or more). (Integer) divided groups are time-division driven, and d / n discharge ports that are continuous in the discharge port array of the k-th divided group (k = 1,..., N) are in order from these discharge ports. The ejection order of the ejection ports ejected first in the k-th divided group is earlier than the ejection order of the ejection ports first ejected in the (k + 1) -th divided group. When time-division driving is performed and the determination unit determines that a recording operation is performed, ink is sequentially discharged from the d discharge ports of the group, and time division other than the continuous time-division driving is performed. A distributed time-division drive Control means to perform;
An ink jet recording apparatus comprising: The control means performs first continuous time-division driving in which the division number n is 2 when the preliminary ejection performed by the preliminary ejection means is performed with the recording head stationary. 3. The second continuous time-division drive in which the division number is 1, when the preliminary ejection performed by the preliminary ejection means is performed by moving the recording head. The ink jet recording apparatus described. The continuous type time-division driving is a driving order in which the ejection port is driven in a state where vibration of a meniscus of ink generated when the adjacent ejection port is driven is generated in the ejection port, and the distributed type The time-sharing drive is in a driving order in which the ejection ports are driven in a state where meniscus vibration of ink generated when the adjacent ejection ports are driven is contained in the ejection ports. 2. An ink jet recording apparatus according to 2. A recording head having a discharge port array in which a plurality of discharge ports are arranged;
A controller that controls the ejection port array to be divided into a plurality of groups for each of a plurality of continuous ejection ports and to perform time-division driving for each group, and performs recording by ejecting ink onto a recording medium. In an inkjet recording apparatus,
When performing preliminary ejection for ejecting ink that is not involved in recording, the control unit divides each group into a first divided group and a second divided group, and the plurality of ejection ports of each divided group have one ejection port. In order from the side and the discharge port of the first divided group and the discharge port of the second divided group are controlled to be alternately discharged,
When performing a recording operation on a recording medium, a plurality of ejection openings in each group are driven in a driving order that is an interval at which ejection of ink meniscus is suppressed when adjacent ejection openings are driven. And an ink jet recording apparatus which is controlled to be driven by 5. The inkjet recording apparatus according to claim 1, wherein each of the plurality of ejection openings includes a heating resistance element that generates energy for ejecting ink. The ink jet recording apparatus according to claim 1, wherein the recording head is mounted on a scanning unit that reciprocally scans a recording medium. It further has a preliminary discharge receiver for receiving ink discharged by the preliminary discharge,
The inkjet recording apparatus according to claim 1, wherein a distance between the preliminary ejection receiver and the recording head is greater than a distance between a recording medium and the recording head. In a control method for an ink jet recording apparatus that uses a recording head in which a plurality of ejection openings are arranged and performs recording by ejecting ink onto a recording medium by performing time-division driving on the plurality of ejection openings from the recording head.
A step of preparing preliminary ejection means for performing preliminary ejection for ejecting ink not involved in recording from the recording head other than the recording medium;
As a recording head operation, a determination step of determining whether a recording operation is performed next or whether preliminary discharge is performed by the preliminary discharge unit;
When the determination step determines that preliminary discharge is performed, the number of d discharge ports of a group consisting of adjacent discharge ports in the array, which is the same as the number of time divisions in the time division drive, is n (one or more). (Integer) divided groups are time-division driven, and d / n discharge ports that are continuous in the discharge port array of the k-th divided group (k = 1,..., N) are in order from these discharge ports. The ejection order of the ejection ports ejected first in the k-th divided group is earlier than the ejection order of the ejection ports first ejected in the (k + 1) -th divided group. When time-division driving is performed and the determination unit determines that a recording operation is performed, ink is sequentially discharged from the d discharge ports of the group, and time division other than the continuous time-division driving is performed. A distributed time-division drive A control process to be performed;
A method for controlling an ink jet recording apparatus, comprising: In the control step, when the preliminary ejection performed by the preliminary ejection unit is performed with the recording head being stationary , the first continuous type time-division driving in which the division number n is 2, preliminary ejection preliminary discharge means is executed, when it is intended to run by moving the recording head, according to claim, characterized in that performing the time division driving of the second continuous the number of division n is 1 8 A method for controlling the ink jet recording apparatus according to the above. The continuous type time-division driving is a driving order in which the ejection port is driven in a state where vibration of a meniscus of ink generated when the adjacent ejection port is driven is generated in the ejection port, and the distributed type 9. The time-division driving in this order is a driving order in which the ejection ports are driven in a state where meniscus vibrations of ink generated when the adjacent ejection ports are driven are contained in the ejection ports. 10. A method for controlling an ink jet recording apparatus according to item 9.

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