JP6095317B2 - Ink jet recording apparatus and recovery processing method for ink jet recording apparatus - Google Patents

Description

  The present invention relates to an inkjet recording apparatus capable of executing an ejection recovery process for ejecting ink from a recording head onto a recording medium in order to recover the ejection performance of the recording head that ejects ink, and a recovery processing method for the inkjet recording apparatus.

  Conventionally, as an ink jet recording apparatus, as shown in Patent Document 1, a recording material stored in a roll shape is conveyed so as to pass in front of a recording head, and ink is discharged from an ejection port of the recording head for recording. What performs is disclosed. The ink jet recording apparatus includes: a recovery processing unit that discharges ink from a discharge port onto a recording material to perform discharge recovery processing; and a cutting unit that cuts the front and rear of the portion of the recording material that has absorbed the discharged ink. Have.

  On the other hand, Patent Document 2 discloses a full-line type long ink discharge head having an element substrate provided with a plurality of ink discharge energy generating elements and a head liquid chamber for holding ink supplied to the element substrate. An inkjet recording apparatus is disclosed. This device is provided with an ink circulation device that continuously flows ink from the ink inlet formed in the head liquid chamber to the ink outlet, so that the ink is continuously supplied in the head liquid chamber even during the ejection operation of the head. Therefore, it is possible to prevent a temperature rise in the head liquid chamber.

JP-A-3-295663 JP 2006-175651 A

  However, the conventional ink jet recording apparatus disclosed in Patent Document 2 can suppress the temperature rise of the recording head, but eliminates the temperature difference that occurs between the element substrates arranged in the ink circulation direction. I can't do it. The technique disclosed in Patent Document 2 does not consider the temperature difference caused by the difference in the arrangement position of each element substrate in the ink circulation direction, and the ejection performance of all element substrates can be reliably recovered. A discharge recovery process is performed by determining a fixed number of ink discharges (discharge amount). In other words, even with a relatively low temperature recording element substrate that is less likely to cause ejection failure in the conventional ejection recovery process, the ejection recovery process is performed with a fixed discharge amount that matches the high temperature element substrate that is relatively susceptible to ejection failure. ing. For this reason, a low-temperature element substrate that can recover the ejection performance with a small discharge amount consumes more ink than necessary, which causes an increase in running cost.

  The present invention has been made paying attention to the above-described problem, and an inkjet recording apparatus capable of performing ejection recovery processing with an appropriate discharge amount in consideration of the temperature of each of a plurality of element substrates, and recovery of the inkjet recording apparatus The purpose is to provide a processing method.

  In order to achieve the above object, the present invention comprises the following arrangement.

The present invention includes a recording head in which a plurality of element substrates having a plurality of nozzles for ejecting ink are arranged, and supplies the ink to the plurality of element substrates while flowing the ink in the recording head, thereby generating image data. Accordingly, an ink jet recording apparatus that forms an image by discharging the ink from the nozzle to the sheet and performs discharge recovery processing of the nozzle by discharging ink from the nozzle to the sheet according to discharge recovery processing data In the present invention, the element substrate positioned on the downstream side in the ink flow direction includes control means for controlling the number of ink ejections in the ejection recovery process to be increased.
In the present invention, a transport mechanism that transports a sheet in a first direction and a plurality of discharge ports are formed along a second direction intersecting the first direction, and ink is discharged from the plurality of discharge ports. A recording head that records an image on a sheet; a tank that stores ink supplied to the recording head; a circulation mechanism that circulates ink between the recording head and the tank; An ink jet recording apparatus comprising: a discharge recovery process for recovering the discharge performance of the recording head by discharging ink from a discharge port to a sheet, wherein the control means includes: Out of a plurality of discharge ports, the amount of ink discharged from the discharge port located on the upstream side in the circulation direction of ink in the recording head is set to the downstream side in the circulation direction. Characterized by less than the amount of ink discharged from the discharge ports for location.
Further, according to the present invention, a transport mechanism that transports the sheet in the first direction and a plurality of discharge ports are formed along a second direction that intersects the first direction, and ink is discharged from the plurality of discharge ports. Ink jet recording apparatus recovery processing method comprising: a recording head that records an image on a sheet; a tank that stores ink supplied to the recording head; and a circulation mechanism that circulates ink between the recording head and the tank. And a discharge recovery step of recovering the discharge performance of the recording head by discharging ink from the discharge ports to a sheet based on discharge recovery processing data, wherein the plurality of discharge ports in the discharge recovery step Among these, the amount of ink discharged from the discharge port located upstream in the circulation direction of ink in the recording head is the discharge located downstream in the circulation direction. Characterized by less than the amount of ink discharged from.

  According to the present invention, it is possible to perform the recovery process with an appropriate discharge amount (number of discharges) in consideration of the temperature of each of the plurality of element substrates. For this reason, it is possible to maintain good ejection performance while suppressing unnecessary consumption of ink, and to reduce running cost.

1 is a perspective view showing an overall configuration of a recording apparatus according to a first embodiment of the present invention. It is sectional drawing which shows the internal structure of the recording device shown in FIG. It is a schematic diagram which shows the example of arrangement | positioning of the several image recorded sequentially on a sheet | seat. FIG. 2 is a schematic diagram illustrating a configuration of an ink supply system of the ink discharge recording apparatus according to the embodiment of the present invention. FIG. 3 is a perspective view of the recording head as viewed from the ejection port surface side. FIG. 6 is a diagram illustrating an overall configuration of the recording head illustrated in FIG. 5. FIG. 6 is a cross-sectional view showing an internal structure of the recording head shown in FIG. 5. (A) is a diagram showing the relationship between the position of the element substrate provided in the recording head of this embodiment and the ink circulation path, (b) is a diagram showing the temperature of each element substrate, and (c) is the temperature of the recording element. FIG. 6 is a diagram illustrating a relationship between ink consumption in the ejection recovery process. It is a figure which shows the discharge recovery process pattern formed in the non-image area | region 101-2 in FIG. It is a figure which shows the discharge recovery process pattern formed in the non-image area | region of a sheet | seat in this embodiment. It is a figure which shows an example of the discharge recovery process pattern in 2nd Embodiment. It is a figure which shows the other example of the discharge recovery process pattern in 2nd Embodiment. It is a figure which shows the discharge recovery process pattern in 3rd Embodiment.

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

(First embodiment)
FIG. 1 is a perspective view showing the overall configuration of the ink jet recording apparatus according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the internal structure of the recording apparatus 1 shown in FIG. As shown in each drawing, the inkjet recording apparatus 1 includes a sheet feeding unit 2, a recording unit 5, a cutter unit 6, and a drying unit from the upstream side to the downstream side in the sheet conveyance direction (A direction) during sheet recording. Unit 7, an ink tank unit 8, a control unit 9, and a paper discharge unit 10.

  The sheet feeding unit 2 holds the sheet 3 wound in a roll shape so as to be rotatable. In the present embodiment, the sheet 3 that is a recording medium is continuous paper, but cut paper may be used. The sheet feeding unit 2 has a transport mechanism 13 for pulling out the sheet 3 and supplying it to the downstream side in the sheet transport direction.

  The recording unit 5 includes a plurality of recording heads 100 corresponding to a plurality of different ink colors. In each recording head 130, a plurality of nozzles that eject ink are arranged along a certain direction. In the following description, the nozzle arrangement direction is also referred to as a main scanning direction, and the sheet conveyance direction (A direction) is also referred to as a sub-scanning direction. The recording heads 100 for each color are arranged side by side in the sub-scanning direction. In this embodiment, an example in which four recording heads corresponding to four colors of cyan (C), magenta (M), yellow (Y), and black (K) are used is shown. Is not limited. Each color ink is supplied from the ink tank 8 to the recording head 130 via an ink tube. Details of the recording head 130 will be described later.

  The recording unit 5 is provided with a sheet conveyance path facing the recording head 130 and has a conveyance mechanism 13 for conveying the sheet along the sheet conveyance path. The conveyance mechanism 13 includes a plurality of conveyance rollers arranged along the sheet conveyance path and a platen having a support surface that supports the sheet 3 between adjacent conveyance rollers. In the recording apparatus of the present embodiment, recording can be performed on the sheets 3 having different widths, and the conveyed sheet 3 is opposed to the nozzle array of the recording head 130 (opposite area), and the sheet 3 is opposed to the nozzle array. There are two different states of the non-opposed area (non-opposing area). The positional relationship between the facing area and the non-facing area and the ratio of both areas vary depending on the width of the sheet to be used.

  The cutter unit 6 is a unit for cutting the continuous sheets recorded by the recording unit 5 for each predetermined size (for each predetermined length in the transport direction), and is provided with a cutter mechanism 6a. The drying unit 7 is a unit for drying the cut sheet ink in a short time. The unit is provided with a heater 11 and a plurality of conveyance rollers 12 are arranged in parallel along the sheet conveyance path. ing. The paper discharge unit 10 stores cut sheets discharged from the drying unit 7, and a plurality of sheets with ink fixed thereon are stacked. The control unit (control means) 9 includes a CPU, a memory, various I / O interfaces, and the like, and controls various controls and driving of the entire recording apparatus.

  In recording, the control unit 9 stores image data transmitted from a host device such as a personal computer connected via an interface in a memory, and then proceeds with an image forming operation while reading the stored image data. . In addition to the image data for recording the image to be formed on the recording medium cut by the cutter mechanism 6a, the memory includes discharge recovery process data and a cut mark for performing the discharge recovery process described later. The discharge data for forming the cut mark for the purpose is also stored.

  FIG. 3 is a schematic diagram showing an arrangement example of a plurality of images (image 1, image 2, image 3,...) Sequentially recorded on the sheet. In the illustrated example, an image area 100 (100-1, 100-2, 100-3,...) And a non-image area 101 (101-1, 101-2, 101-3,. ) And are lined up alternately. That is, a non-image area is arranged between adjacent image areas. Further, in this arrangement example, the cut marks 102 (102-1, 102-2, 102-3,...) For determining the cutting positions of the non-image areas are formed in the respective non-image areas 101. A formation region is provided. On the other hand, the pattern 103 for the ejection recovery process of the recording head is formed only in some non-image areas (only 101-3 in FIG. 3). Further, the non-image area (101-1, 101-3) including the pattern 103 and the non-image area (101-2) not including the non-image area have different sizes (lengths) in the transport direction of the non-image area. Yes.

  When the cut mark formed on the sheet is detected by the cut mark sensor (cut mark detection means) 19, the control unit 9 drives the cutter unit 6 at a predetermined timing based on the detected signal, and the non-image region is detected. Cut the rear end and the front end. The cut mark sensor 19 is a small optical sensor having a light source and a light receiving element. For example, the cut mark 102 is a rectangular mark of 2 × 2 [mm], for example, and the spot diameter of the illumination light 110 illuminated on the cut mark 102 is φ1 [mm]. A small semiconductor light source (LED, OLED, semiconductor laser, etc.) is suitable for the light source. For example, a red LED is used as the light source, and black ink having a good light absorption distribution characteristic with respect to red is used for recording the cut mark 102. In the sheet conveyance direction (A direction), the non-image areas 101 (101-1, 101-2, ...) have a width of a predetermined length M (4 mm). In order to facilitate the distinction between the image area 100 (100-1, 100-2...) And the cut mark 102, in the present embodiment, the previous image area 100- (n-1) and the cut mark are separated. A blank having a length half of the length M (2 [mm]) is formed between 102 and n. However, it is not essential to provide such a blank.

  Next, the structure of the recording head 130 in the ink jet recording apparatus according to the present embodiment will be described with reference to FIGS. 4 is a schematic diagram of an ink supply system of the ink jet recording apparatus, and FIG. 5 is a perspective view of the recording head 130 as viewed from the discharge port surface side. 6 and 7 are diagrams showing the configuration of the recording head 130 shown in FIG. 5 in more detail. FIG. 6 is a diagram for explaining the overall configuration 100 of the recording head 130. FIG. It is a cross-sectional view which shows the internal structure of. FIG. 6 shows a state in which four element substrates are provided for simplification of explanation, (a) is a bottom view, and (b) is a line aa in FIG. 6 (a). (C) is a side view, (d) is a top view, and (e) is a cross-sectional view taken along the line cc of FIG.

  As shown in FIG. 5, the actual recording head 130 in this embodiment includes 18 element substrates 121 having an effective ejection width of about 0.85 inches. These element substrates 121 are bonded in a zigzag manner to a base substrate 111 that is a support member, and are electrically connected to the flexible wiring substrate 106 by wire bonding at electrode portions at both ends thereof.

  As described above, since the 18 element substrates 121 are used in the present embodiment, the entire effective ejection width of the recording head 130 has a length of about 12 inches. This is a length substantially coincident with the length of the A3 size sheet 3 in the short side direction. A sheet 3 is conveyed in the longitudinal direction with respect to the recording heads 130 for each color, and each of the recording heads 130 scans the sheet 3 once, thereby completing a full-color image.

  FIG. 7 is a sectional view of the recording head 130. The element substrate 121 is formed with a plurality of ejection openings 102 which are the opening ends of nozzles for ejecting ink, and ink droplets of ink ejected from the respective ejection openings 102 are landed on the sheet so that an image is printed. Recording is performed. On the element substrate 121, unillustrated heating elements (electrothermal conversion elements or heaters) as discharge energy generating elements are formed corresponding to the respective discharge ports 102. The heat generating element generates heat when energized, generates bubbles in the ink by the heat, and discharges ink droplets from the discharge port 102 by the generated pressure of the bubbles. The electrode part of the element substrate 121 and the flexible wiring board 106 are connected by a wire bonding part. Ink droplets scattered from the ejection port 102 or ink droplets bounced off from the medium may adhere to the wire bonding portion and corrode the electrode of the wire bonding portion or its underlying metal. For this reason, the wire bonding portion and the like are covered and sealed with a sealing agent 107 such as a silicon-based resin having excellent sealing properties and ion blocking properties so that the connection reliability is not lowered due to ink adhesion. It is.

  Further, as shown in FIGS. 6B and 7, a filter member 151 is attached to each element substrate 121 via a filter support member 150 on the back side. The filter member 151 has a configuration in which a fine stainless steel wire is woven so as not to allow a foreign substance having a particle size large enough to block the discharge port 102 to pass through the discharge port 102. Yes. In the present embodiment, a filter member having an eye that does not allow passage of foreign matters having a diameter of 10 μm or more is used. The same filter support member 150 and filter member 151 are attached to each element substrate 121. The area of the filter member 151 has a sufficiently large area that does not cause a large pressure loss with respect to the maximum ink flow rate when all the discharge nozzles of the corresponding element substrate 121 perform the liquid discharge operation. . Since the filter member is provided corresponding to each ejection port, no pressure loss occurs when ink is supplied, and a sufficient amount of ink is stably supplied to the ejection port 102. Therefore, a sufficient amount of ink is ejected from the nozzles in one ejection operation, and it is possible to prevent the occurrence of density reduction and non-ejection during recording.

  As shown in FIG. 7, the element substrate 121 in which the discharge ports 102 are formed is provided on the base substrate 111. A slit-like opening 104 is provided in a portion of the base substrate 111 corresponding to the discharge port 102, and one common liquid chamber 110 for holding ink is formed for one element substrate 121. . The common liquid chamber 110 is opened with a length substantially equal to the length of the discharge port array. The base substrate 111 is provided with 18 element substrates 121 in a staggered manner. A head liquid chamber member 112 is bonded so as to cover all 18 filter members 151 corresponding to the element substrates 121, thereby forming a head liquid chamber 109 common to the element substrates. As shown in FIGS. 6D and 6E, ink outlets 113 and 114 provided so as to communicate with the head liquid chamber 109 are provided at almost both ends of the head liquid chamber member 112. An ink inlet 115 is provided at a substantially central portion of the liquid chamber member.

  Next, the ink supply path in the present embodiment will be described with reference to FIG. The ink inlet 115 and the ink outlets 113 and 114 provided in the head liquid chamber member 112 are connected to tubes 166, 167a, and 167b, respectively, as shown in FIG. The ink in the liquid storage tank 161 is supplied from the ink inlet 115 into the head liquid chamber 109 by the liquid supply pump 162. A part of the ink in the head liquid chamber 109 passes through the filter member 151 corresponding to each element substrate 121 as shown in FIG. 7 and then passes through each common liquid chamber 110 and the slit 104 to each discharge port. 102 is discharged.

  On the other hand, ink that has not been used for ejection among the ink supplied into the head liquid chamber 109 is discharged from the ink outlets 113 and 114 by the action of the liquid suction pump 163, and passes through the tube 167 d to be stored in the liquid storage tank 161. It is configured to be returned to. The ink in the liquid storage tank 161 is again circulated to the recording head 130 by the liquid supply pump.

  In the recording head 130 of the present embodiment, the ink outlets 113 and 114 are provided at positions close to both ends of the head liquid chamber 109 with respect to the ink inlet 115 provided in the substantially central portion of the head liquid chamber 109. . 4 shows the case where two ink inlets 115 are provided at substantially the center as shown in FIG. 4, but one ink inlet 115 is provided at the center of the head liquid chamber 109 as shown in FIG. May be provided.

  The ink that has flowed into the head liquid chamber 109 from the ink inlet 115 flows in approximately two halves in two directions: the ink outlet 113 direction and the ink outlet 114 direction. That is, the length of the ink flowing in the head liquid chamber 109 can be approximately half the total length of the recording head 130 (the total length of the recording head in the direction intersecting the nozzle arrangement direction (orthogonal direction in the drawing)). become. In addition, since the distance from the ink inlet 115 to the ink outlet 114 is approximately ½ of the total length of the recording head 130, the ink flowing into the head liquid chamber 109 from the ink inlet 115 becomes the ink. The staying time until it flows out from the outlet 114 is also almost halved. Therefore, even when high-speed printing or continuous printing is performed using a full-line head, the temperature rise of the recording head 130 can be further suppressed, and ink can be stably ejected. Further, since the length of ink flow in the head liquid chamber 109 is halved, the temperature difference in the circulation path is reduced, and as a result, a good recorded image without density unevenness can be obtained.

  FIG. 8A shows the relationship between the positions of the 18 element substrates provided in the recording head 130 of this embodiment and the ink circulation path. In the following description, in order to distinguish the 18 element substrates, the element substrates are denoted by reference numerals CH0 to CH17. The ink circulation paths C1 and C2 have a symmetrical shape with respect to the center point of the recording head, and the heat transfer characteristics are also symmetrical. Accordingly, here, a description will be given by taking as an example the case where the ink ejection operation is performed on the recording element substrates CH0 to CH8 belonging to the ink circulation path C1. In FIG. 8B, ink of about 30 ° C. is circulated in the liquid chamber of the recording head 130, and continuous recording is performed on the roll paper having the maximum width (12 inches) with the maximum recording duty per color. It is the figure which plotted the state in which the output (temperature) of the temperature detection element with which it equipped was substantially saturated. As shown in the figure, the temperature of the element substrate CH8 near the circulation path inlet 115 is about 30 ° C., and the temperature of the element substrate CH0 near the outlet is about 38 ° C.

  FIG. 8C shows the ink consumption ratio of the ejection recovery process executed at predetermined intervals on the roll paper with respect to the temperature of the element substrate. When continuous recording is performed at the maximum recording duty, the temperature of the recording element substrate is 39 ° C. It can be seen that the ink consumption required for recovering the ejection state at this time is 1.45 times the ink consumption required for continuous recording at the minimum recording duty (29 ° C.). That is, it can be said that the higher the temperature of the recording element substrate, the more the number of ejections required to restore the ejection state, and the greater the ink consumption. This is because when the temperature of the recording element substrate is high, the amount of water that volatilizes from the ejection port increases, and the ink tends to thicken.

  FIG. 9 is a diagram showing details of the non-image area 101-2 in FIG. The non-image area 101-2 is formed by a cut mark formation area R1 and an ejection recovery process pattern formation area R2. As shown in the figure, the ejection recovery process pattern 103 performs the ejection recovery process with the same ejection recovery process pattern from the element substrates CH0 to CH17 of the recording head 130. The amount of ink consumed in this ejection recovery process is generally the amount of ink consumed that does not lead to ejection failure even on element substrates that are exposed to the worst conditions during recording operations, that is, element substrates that are most likely to suffer from poor ejection performance. Designed to. That is, as shown in FIG. 9, the ink consumption for all the element substrates CH0 to CH17 is designed in accordance with the ink consumption of the element substrate CH0. The ejection recovery process pattern at this time is defined by a bitmap image so that the number of ejections from each nozzle is constant. However, if a bitmap image is assigned to all the nozzles, the size of the register circuit for generating the bitmap image increases. Therefore, an m × n basic pattern is defined, and the pattern is arranged in the nozzle arrangement direction and the sheet conveyance. Data processing is repeated for each direction.

  As described above, by carrying out the discharge recovery process with the same number of discharges on all the element substrates, all the element substrates are recovered to have good discharge performance. However, in this case, since the ink is consumed more than necessary, there arises a problem that the running cost increases. That is, among the element substrates, the lower the temperature of the element substrate, the less the deterioration of the ejection performance, and therefore the number of ejections necessary for the ejection recovery process, that is, the amount of ink to be consumed is small. However, in the discharge recovery process shown in FIG. 9, since the number of discharges of other element substrates is determined in accordance with the element substrate CH0 having the highest temperature, the number of discharges is excessive in the low-temperature element substrate, and the discharge recovery process is performed. As a result, more ink than necessary is consumed. This excessive ink consumption causes the running cost to increase.

  Therefore, in the ink jet recording apparatus according to the present embodiment, bitmap pattern data for forming an ejection recovery process pattern is changed for each element substrate.

  FIG. 10 is a diagram illustrating an ejection recovery process pattern formed in the non-image area of the sheet in the present embodiment. In the present embodiment, the discharge recovery process pattern data for forming the discharge recovery process pattern is optimized for each element substrate based on the temperature distribution of the recording head 130 in FIG. That is, in the ink circulation flow path from the ink inlet of the recording head to the ink outlet, the temperature of the element substrate decreases as the ink inlet 115 is closer, and conversely, the temperature of the element substrate decreases as the ink outlets 113 and 114 are closer. Becomes higher. In other words, the element substrate positioned upstream in the ink circulation flow path formed in the recording head has a lower temperature, and the element substrate positioned downstream in the ink circulation flow path has a higher temperature. According to such a temperature distribution, in the present embodiment, the element substrate whose temperature is high causes the number of ejections to be increased and a large amount of ink to be discharged. The ejection recovery process pattern data is set so as to reduce the number of ejections and discharge a small amount of ink.

  FIG. 10 shows an example of a discharge recovery process pattern in the present embodiment. In the present embodiment, in the ink circulation channel C1, ejection is performed such that the ink discharge amount gradually increases from the element substrate CH8 closest to the ink inlet to the element substrate CH0 located on the most downstream side of the ink circulation channel. A recovery process pattern is defined. In the other ink circulation channel C2, the discharge recovery is such that the ink discharge amount increases gradually from the element substrate CH9 closest to the ink inlet to the element substrate CH17 located on the most downstream side in the ink circulation channel. A processing pattern is defined. That is, the ejection recovery pattern formation data is defined so that an ejection recovery process pattern is formed so that the element substrate positioned downstream in the ink flow direction increases the number of ejections in the ejection recovery process. Note that the ejection recovery process pattern shown here has more margins (areas not shaded in the drawing) where ink is not ejected than the ejection recovery process pattern shown in FIG. It can be seen that the ink consumption at is suppressed. In addition, since each ejection recovery processing pattern is set to the minimum number of ejections necessary to restore the ejection performance of the element substrate, the ejection performance can be recovered while suppressing wasteful ink consumption.

(Second Embodiment)
Next, a second embodiment of the present invention will be described based on FIG. 11 and FIG. The second embodiment also has the same configuration as that shown in FIGS. 1 to 8 described in the first embodiment.

  FIG. 11 shows the nozzle ejection recovery process used when recording an image having a width of about half (about 6 inches) of an image having a width of 12 inches which is the maximum recording width of the recording head in the second embodiment. It is a figure which shows the pattern (discharge recovery process pattern) for performing. FIG. 12 is a diagram showing a pattern (discharge recovery process pattern) for performing the discharge recovery process of the nozzles used when recording a 6-inch image. However, the ejection recovery process pattern shown in FIG. 12 is obtained by shifting the relative positions of the recording head and the sheet along the nozzle arrangement direction (direction orthogonal to the transport direction).

  As is apparent from the comparison between FIG. 11 and FIG. 12, even when an image having the same width is formed, the ejection recovery processing pattern differs depending on the position of the nozzle used (position of the element substrate) in the image formation. If the relative positional relationship between the used nozzle and the sheet does not change, the discharge recovery process is performed by a simple process using a part of the discharge recovery process pattern of FIG. 10 as shown in FIG. 11 based on the sheet width information. Pattern data can be obtained.

  On the other hand, as shown in FIG. 12, when the relative position of the sheet and the recording head in the nozzle arrangement direction is changed, in the present embodiment, according to the element substrate (used element substrate) to be used for image formation. The ejection recovery process is performed using the ejection recovery process pattern. That is, in the present embodiment, the sheet width information and the recording head position information in the nozzle arrangement direction are acquired, the relative position between the sheet and the used nozzle (used element substrate) is determined based on both information, and the relative position is determined. A discharge recovery process pattern is determined based on the position. Sheet width information can be acquired by detecting the positions of both ends in the width direction of the sheet with an optical sensor or the like, but it is used based on the recording head position information and sheet width information previously input by the user. The relative position between the element substrate and the sheet may be determined.

  The relative position between the used element substrate and the sheet can be determined, for example, as follows. First, as shown in FIG. 11, the recording head when the central axis L0 in the sheet width direction (nozzle arrangement direction) and the central axis L1 in the recording head width direction (nozzle arrangement direction) are located on the same straight line. Is the first position. Here, when the position of the recording head 130 is moved to the second position shown in FIG. 12 by a known head moving mechanism, the position of the used element substrate of the recording head 130 is shown in FIG. Shift from the position shown to the position shown in FIG. That is, in FIG. 12, the element substrate used is moved by four element substrates from the first position shown in FIG. 11 to the end side. After determining the position of the used element substrate in this way, an ejection recovery process pattern is set according to the position of the used element substrate, and an ejection recovery process is performed.

  Each of the ejection recovery processing patterns shown in FIGS. 11 and 12 increases the number of ink ejections (discharge amount) as the element substrate is located farther from the ink inlet. Therefore, also in the second embodiment, as in the first embodiment, it is possible to restore the ejection performance while suppressing wasteful ink consumption.

  In the second embodiment, when an image having a width smaller than the total length of the nozzle array arranged in the recording head is formed, it is avoided that only a specific nozzle in the nozzle array is used and deteriorated. Therefore, the recording head 103 is moved by a known head moving mechanism. Further, when the nozzle used is changed, the discharge recovery pattern of each element substrate to be discharged and recovered is changed according to the change, thereby making it possible to execute an appropriate discharge recovery process.

(Third embodiment)
Next, a third embodiment of the present invention will be described. The third embodiment also has the same configuration as the configuration shown in FIGS. 1 to 8 described in the first embodiment.

  FIG. 13 is a diagram showing a discharge recovery process pattern that is discharged to a non-image area of a sheet by the discharge recovery process in the third embodiment. In the ejection recovery process pattern shown in FIG. 13, the cut mark pattern formation area R1 and the ejection recovery process pattern formation area R2 in the non-image area are overlapped, and the cut mark pattern 102 is placed in the ejection recovery process pattern formation area R2. Try to form. That is, the discharge recovery process pattern 103 is formed in the discharge recovery process pattern formation region R2, and the cut mark 102 is formed in a blank portion where the discharge recovery process pattern 103 is not formed.

  As shown in FIG. 13, in the case where the ink inlet is formed in the substantially central portion of the recording head 130, the temperature of the element substrate closer to the ink inlet is lower, so the ejection recovery processing pattern is a small area pattern. It becomes. Accordingly, in the region R2, a large area margin is formed in a portion where the above-described small area ejection recovery process pattern is formed. If the cut mark 102 is formed here, the cut mark and the ejection area are discharged. It is possible to avoid overlapping with the recovery processing pattern. As described above, according to the third embodiment, it is possible to reduce the area of the non-image area (the hatched area in FIG. 13) where ink is not ejected from the sheet, and the non-image area is consumed. It is possible to reduce the sheet amount.

  Note that the cut mark sensor (cut mark detection means) in the ink jet recording apparatus according to the present embodiment is a sensor having an aperture sufficiently smaller than the recording width (length in the nozzle arrangement direction) of the cut mark 102. The cut mark is formed near the ink inlet of the ink circulation path of the recording head in the recording width direction. For this reason, the mark detection sensor is disposed at a position where the cut mark 102 can be detected on the upstream side of the cutter mechanism 6a in the sheet conveying direction.

  In some cases, only the cut mark 102 is recorded in the non-image area as in the non-image areas 101-1 and 101-3 in FIG. For this reason, in the third embodiment, when roll paper is continuously recorded, the ejection data for recording only the cut mark and the ejection data for forming the cut mark and the ejection recovery process pattern are set according to the non-image area. May be selectively used. Also in the third embodiment, when the used nozzle in the nozzle row is changed, it is necessary to change the ejection recovery pattern in accordance with the change. However, in the third embodiment, both the cut mark 102 and the discharge recovery pattern are formed in the discharge recovery pattern formation region R2. Therefore, it is desirable to set the relationship among the region R2, the discharge recovery pattern 103, and the cut mark 102 so that the discharge recovery pattern and the cut mark 102 do not overlap.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 Sheet | seat 9 Control part 19 Cut mark sensor 101 Non-image area | region 102 Cut mark 103 Discharge recovery process pattern 113,114 Ink outlet 115 Ink inlet 130 Recording head CH1-CH17 Element substrate R1 Cut mark formation area R2 Ejection Recovery processing pattern formation area

Claims (20)

A recording head having a plurality of element substrates each having a plurality of nozzles for discharging ink, the ink being supplied to the plurality of element substrates while flowing the ink in the recording head, and the nozzles corresponding to image data An ink jet recording apparatus that forms an image by discharging the ink from a nozzle to a sheet, and performs discharge recovery processing of the nozzle by discharging ink from the nozzle to the sheet according to discharge recovery processing data,
An ink jet recording apparatus comprising: control means for controlling the element substrate located downstream in the ink flow direction to increase the number of ink ejections in the ejection recovery process.   2. The recording head according to claim 1, wherein the recording head includes an inflow port through which the ink flows in and an outflow port through which the ink flows out, and causes the ink flowing in from the inflow port to flow toward the outflow port. Inkjet recording apparatus.   The inkjet recording apparatus according to claim 2, wherein the inflow port is located at a central portion of the recording head, and the outflow port is located near both end portions of the recording head. The nozzles formed on each element substrate are arranged along a certain direction,
The sheet is a continuous paper conveyed in a direction intersecting the arrangement direction of the nozzles,
The image formed on the sheet is formed through a certain interval,
4. The inkjet recording apparatus according to claim 3, wherein the control unit performs the ejection recovery process by ejecting the ink to a non-image area located between images before and after being formed on the sheet. 5.   In the non-image area, an ejection recovery process pattern forming area in which an ejection recovery process pattern is formed by ink ejected from the nozzles in the ejection recovery process, and a cut mark for determining a cutting position of the non-image area are formed. The inkjet recording apparatus according to claim 4, further comprising: a cut mark forming region for performing the operation.   The non-image area includes an ejection recovery process pattern formation area in which an ejection recovery process pattern is formed by ink ejected from the nozzles in the ejection recovery process. The inkjet recording apparatus according to claim 4, wherein a cut mark for determining a cutting position of the image area is formed.   The cut mark is formed in all non-image areas of the sheet, and the ejection recovery process pattern is formed in a part of the non-image areas in all the non-image areas. The ink jet recording apparatus according to 5 or 6. The cut marks are formed by a nozzle which is located near the inlet, either the 5 to claim, characterized in that the cut mark detecting means to a detectable position a cut mark is located 7 2. An ink jet recording apparatus according to item 1.   2. The device according to claim 1, wherein among the element substrates used for forming the image, an element substrate located on the downstream side in the ink flow direction increases the number of ejections in the ejection recovery process. 2. An ink jet recording apparatus according to 1. A recording head having a plurality of element substrates each having a plurality of nozzles for discharging ink, the ink being supplied to the plurality of element substrates while flowing the ink in the recording head, and the nozzles based on image data A recovery process for an ink jet recording apparatus that forms an image by discharging the ink from a sheet to a sheet and performs a discharge recovery process for the recording head by discharging ink from the nozzle to the sheet according to discharge recovery process data A method,
The recovery processing method of an ink jet recording apparatus, wherein the number of ink ejections in the ejection recovery process is increased as the element substrate is positioned downstream in the ink flow direction. A transport mechanism for transporting the sheet in the first direction;
A plurality of ejection openings formed along a second direction intersecting the first direction, and a recording head that ejects ink from the plurality of ejection openings to record an image on a sheet;
A tank for storing ink to be supplied to the recording head;
A circulation mechanism for circulating ink between the recording head and the tank;
Control means for performing discharge recovery processing for recovering the discharge performance of the recording head by discharging ink from the discharge port to a sheet based on discharge recovery processing data,
In the ejection recovery process, the control unit positions an ink ejection amount from an ejection port located upstream in the circulation direction of ink in the recording head among the plurality of ejection ports downstream in the circulation direction. An ink jet recording apparatus characterized in that the amount is less than the amount of ink discharged from the discharge port. In the recording head, a plurality of element substrates each having a plurality of ejection openings formed along the second direction are provided along the second direction.
The circulation mechanism supplies ink to the plurality of element substrates while circulating ink between the recording head and the tank,
In the ejection recovery process, the control means determines an ink ejection amount from an ejection port formed on an element substrate located upstream of the plurality of element substrates in the ink circulation direction in the recording head. The ink jet recording apparatus according to claim 11, wherein the ink discharge amount is less than an ink discharge amount from an discharge port formed in an element substrate positioned on the downstream side of the ink jet recording apparatus. The recording head has an inflow port through which the ink in the tank flows into the inside and an outflow port through which the ink in the tank flows out into the tank, and moves the ink that has flowed in from the inflow port toward the outflow port. The inkjet recording apparatus according to claim 11 or 12, 14. The ink jet recording apparatus according to claim 13, wherein the inflow port is positioned at a substantially central portion of the recording head, and the outflow port is positioned at both ends of the recording head. The sheet is continuous paper;
The recording head records images on the sheet at substantially constant intervals;
15. The discharge recovery process according to claim 11, wherein the control unit performs the discharge recovery process by causing the recording head to discharge ink to a non-image area between the images recorded on the sheet. The ink jet recording apparatus according to any one of the above. The non-image area includes an ejection recovery process pattern forming area in which an ejection recovery process pattern is formed by ink ejected from the ejection port in the ejection recovery process, and a cut mark for determining a cutting position of the non-image area. The inkjet recording apparatus according to claim 15, further comprising a cut mark formation region for forming the cut mark. The non-image area includes an ejection recovery process pattern formation area in which an ejection recovery process pattern is formed by ink ejected from the ejection port in the ejection recovery process, and the non-image area is formed in a blank portion in the ejection recovery process pattern formation area. 16. The ink jet recording apparatus according to claim 15, wherein a cut mark for determining a cutting position of the image area is formed. The cut mark is formed in all non-image areas of the sheet, and the ejection recovery processing pattern is formed in a part of the non-image areas in all the non-image areas. Item 17. The ink jet recording apparatus according to Item 17. The recording head has an inflow port through which the ink in the tank flows.
19. The cut mark is formed by a discharge port disposed near the inflow port, and a cut mark detection unit is disposed at a position where the cut mark can be detected. 2. An ink jet recording apparatus according to item 1. A conveyance mechanism that conveys the sheet in the first direction and a plurality of ejection openings are formed along a second direction that intersects the first direction, and ink is ejected from the plurality of ejection openings to record an image on the sheet. An ink jet recording apparatus recovery processing method comprising: a recording head; a tank that stores ink supplied to the recording head; and a circulation mechanism that circulates ink between the recording head and the tank.
A discharge recovery step of recovering the discharge performance of the recording head by discharging ink from the discharge port to the sheet based on discharge recovery processing data;
In the discharge recovery step, the ink discharged from the discharge ports located on the upstream side in the circulation direction of the ink in the recording head among the plurality of discharge ports is the ink discharged from the discharge ports located on the downstream side in the circulation direction. A recovery processing method for an ink jet recording apparatus, wherein the recovery amount is less than an ejection amount.

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