JP2021084320A - Recording device and recording method - Google Patents

Abstract

To suppress density unevenness in performing recording using a recording head-joint head in which a plurality of discharge port rows are deviatedly arranged.SOLUTION: It is determined whether there is a predetermined area where recording is performed by a joint part multiple times. When the recording is performed multiple times, in at least one recording, a pixel that is recorded in a crossing direction of the predetermined area is recorded by discharge ports of both discharge port rows forming the joint part, and in the other at least one recording, a pixel that is recorded in the crossing direction of the predetermined area is recorded by discharge ports of one discharge port row of the discharge port rows forming the joint part.SELECTED DRAWING: Figure 9

Description

The present invention relates to a recording device and a recording method.

In an inkjet recording device, a full-line head recording device having a row of ejection ports having a width of a recording medium and a recording device having a long recording head are known even in a serial printer.

In Patent Document 1, recording is performed using a print head that is elongated by arranging a plurality of relatively inexpensive short head chips in a direction that intersects the nozzle row direction. Is described.

There is a concern that the ink landing position may shift from chip to chip when recording an image due to variations in ejection characteristics and mounting errors that occur in the recording head manufacturing process, resulting in unevenness in the recorded image. Will be done.

In order to suppress such unevenness, Patent Document 2 discloses that the region where the ejection ports of the plurality of chips overlap is recorded by using the ejection ports of the plurality of chips.

Japanese Unexamined Patent Publication No. 2005-161681 Japanese Unexamined Patent Publication No. 5-57965

In a multi-pass where an image is recorded by ejecting ink to the same area of the recording medium multiple times, when recording is performed by the joint portion in the region recorded by the joint portion where the chips overlap. Even if the image is recorded by using the method of Patent Document 2, there is a possibility that the density difference from the recorded region due to the non-joint portion where the chips do not overlap can be easily recognized.

The present invention has been made in view of the above problems, and an object of the present invention is to suppress density unevenness when recording is performed using a recording head connecting head in which a plurality of discharge port rows are arranged in a staggered manner.

The present invention has a plurality of ejection port rows in which a plurality of ejection ports for ejecting ink are arranged along a predetermined direction, and the ends of the ejection port rows are arranged in an intersecting direction intersecting the predetermined direction. A recording head in which the discharge port rows are arranged so as to be displaced from each other in the predetermined direction so that a connecting portion is formed, a scanning means for scanning the recording head in the crossing direction, and the recording head in the scanning means. A recording device including a control means for controlling a recording operation so as to eject an ink from the recording head and record an image on a recording medium while moving in the intersecting direction. The control means is the connecting portion. The recording by at least one scan of the scans for recording by the joint portion with respect to the predetermined region which is the region where the ink is ejected a plurality of times by the ejection port of the predetermined region is recorded in the intersecting direction of the predetermined region. The recording by at least one scan of the scans in which the pixels are recorded by the discharge ports of both discharge port rows forming the joint and recorded by the joint for the predetermined area is The pixel to be recorded in the crossing direction of the predetermined region is recorded by the discharge port of one of the discharge port rows forming the connecting portion.

When the same area is recorded by the connecting portion a plurality of times, the density unevenness between the non-joining portion and the connecting portion can be suppressed by differently using the discharge port of the connecting portion in the multiple recordings. ..

It is a perspective view which shows the internal mechanism of the inkjet recording apparatus which concerns on 1st Embodiment. It is sectional drawing of the inside of the recording apparatus which concerns on 1st Embodiment. It is a schematic diagram of the discharge port surface of the recording head which concerns on 1st Embodiment. It is a block diagram for demonstrating the schematic structure of the control system of the recording apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the image processing of 1st Embodiment. It is a figure for demonstrating the recording method of the joint part of 1st Embodiment. It is a figure of the mask pattern of the 1st embodiment. It is a figure explaining the generation process of the recorded data of 1st Embodiment. It is a figure explaining the multipath recording of 1st Embodiment. It is a figure explaining the multipath recording of 1st Embodiment. It is a figure for demonstrating the method of using the nozzle of the joint part at the time of 6 passes in 1st Embodiment. It is a figure of the mask pattern of the 1st embodiment. It is a flowchart of the process of selecting a mask pattern of 1st Embodiment. It is a flowchart of the process of selecting the mask pattern of the 2nd Embodiment. It is a flowchart of the process of selecting a mask pattern of 3rd Embodiment. It is a correspondence table of the mode, the type of the recording medium, and the number of passes.

(First Embodiment)
FIG. 1 is a perspective view showing an internal mechanism of the inkjet recording device 1 (hereinafter, simply referred to as recording device 1) according to the present embodiment. The recording device 1 according to the present embodiment mainly recovers the recording performance of the feeding unit that feeds the recording medium, the transport unit that conveys the recording medium, the discharge unit that discharges the recording medium on which the image is recorded, and the recording unit. It is composed of recovery parts and the like.

The feeding unit has a feeding tray for loading a plurality of recording media and a feeding roller for feeding the recording media loaded on the feeding tray one by one into the recording device 1.

The transport unit includes a transport roller 8 that transports the recording medium fed from the feed unit, and a pinch roller that is arranged at a position facing the transport roller 8 and holds the recording medium together with the transport roller 8.

The recording unit includes a recording head 3 having an ejection port surface provided with an ejection port for ejecting ink (hereinafter, the ejection port is also referred to as a nozzle), and a carriage 2 on which the recording head 3 is detachably mounted. .. In the present embodiment, the recording head 3 can eject four colors of ink, cyan ink, magenta ink, yellow ink, and black ink. The carriage 2 is configured to be reciprocally movable in the X direction (movement direction of the carriage) which is a predetermined direction along the guide shaft 7 via a timing belt 5 attached to the chassis 4 by driving the carriage motor 6. .. The recording medium P is conveyed in the Y direction, which is an intersecting direction that intersects the X direction. The recording head 3 records an image by ejecting ink to the recording medium P stopped at a position facing the recording head 3 while the carriage 2 is reciprocating. A platen 15 (see FIG. 2) that supports the recording medium from below is provided at a position facing the recording head 3 so as to keep the distance between the surface of the recording medium P and the discharge port surface of the recording head 3 constant. ing.

The discharge unit includes a discharge roller (not shown) that discharges the recording medium on which the image is recorded to the outside of the recording device, and a spur roller 11 that holds the recording medium at a position facing the discharge roller.

The recovery unit has a cap 30 (see FIG. 2) that covers the discharge port surface 20 of the recording head 3 outside the recording area in the moving direction of the carriage 2. The cap 30 is provided with an absorber that absorbs ink, and the absorber comes into contact with the ejection port surface 20 to cover the ejection port surface 20. The home position of the recording head 3 is a position where the discharge port surface 20 can be covered by the cap 30. Further, the recovery unit sucks ink from the recording head 3 by driving a suction pump 31 connected to the cap 30 via a tube (not shown) in a state where the cap 30 covers the discharge port surface 20 of the recording head 3. Has a suction mechanism.

FIG. 2 is a schematic cross-sectional view of the inside of the recording device 1 when viewed from the Y direction. The recording medium P fed from the feeding unit is sandwiched and conveyed by the transfer roller 8 and the pinch roller 9 provided on the upstream side of the recording head 3 in the Y direction, and is conveyed on the platen 15. Then, as the transport progresses, it is also sandwiched by the discharge roller and the spur roller 11 provided on the downstream side of the recording head 3 in the Y direction. The recording medium P is sandwiched and conveyed while the surface is kept flat in a state where tension is generated between the transfer roller 8 and the pinch roller and the discharge roller and the spur roller 11. The optical sensor 13 is used to determine whether or not the recording medium P is on the platen 15.

The conveyed recording medium P has one band (one line feed) due to ink droplets being ejected from the ejection port of the recording head 3 mounted on the carriage 2 that moves in the X direction while the conveying is stopped. ) Image is recorded. When an image for one band is recorded, the recording medium P is conveyed in a predetermined amount in the Y direction by driving the transfer roller 8 by a transfer motor (not shown). The reciprocating movement of the carriage 2, the ejection of ink droplets by the recording head 3, and the transfer of a predetermined amount of the recording medium P by the transfer roller 8 (intermittent transfer) are alternately repeated, so that an image is displayed on the entire recording medium P. Recorded. When the recording is completed, the recording medium is cut by the cutter 35 and discharged.

(Recording head)
FIG. 3 shows a schematic view of the discharge port surface 20 of the recording head 3. As shown in FIG. 3A, in the recording head of the present embodiment, three chips are arranged so as to be offset in the Y direction. The chip 1 is arranged on the upstream side in the transport direction (Y direction). As shown in FIG. 3B, discharge ports are arranged on each chip. The ends of the chip 1 and the chip 2 and the ends of the chip 2 and the chip 3 are arranged so as to be aligned in the X direction. The chip arrangement shown in FIG. 3A is a chip for one color. Since four colors of ink can be ejected in the present embodiment, the recording head 3 has four chips shown in FIG. 3A.

As shown in FIG. 3B, the discharge ports at the ends arranged in the X direction are referred to as connecting portions. Further, the discharge port of the joint portion between the chip 1 and the chip 2 is referred to as OL12, and the discharge port of the joint portion between the chip 2 and the chip 3 is referred to as OL23. Each chip is provided with 1224 ejection ports, and the ejection ports are numbered 1 to 3068 in order from the + Y direction of the chip 1. The discharge ports arranged in the X direction of the connecting portion have the same number. In the present embodiment, the connecting portions are for 32 discharge ports, OL12 is a discharge port from 1193 to 1224, and OL23 is a discharge port from 2385 to 2416.

In the present embodiment, each chip has been described as having a single row of discharge ports, but a chip having a plurality of rows of discharge ports in the same chip may be used. In the following description, the discharge port row may be referred to as a nozzle row.

(Block Diagram)
FIG. 4 is a block diagram for explaining a schematic configuration of a control system of the recording device 1. The main control unit 300 is provided with a CPU 301 that controls operations and control of the entire device, a ROM 302 that stores a control program or the like to be executed by the CPU 301, a RAM 303 that is used as a buffer for recorded data, an input / output port 304, and the like. There is. The CPU 301 controls each mechanism by driving each drive circuit 305 to 308 via the input / output port 304. The LF motor 312 is driven by the drive circuit 305, and the transport roller 8 and the discharge roller for transporting the recording medium P connected to the LF motor 312 are driven. The CR motor 313 is driven by the drive circuit 306, and the carriage 2 connected to the CR motor 313 moves. The recording head 3 is driven by the drive circuit 307, and ink is ejected. The cutter is driven by the drive circuit 308, and the recording medium P is cut off. Further, the CPU 301 includes an optical sensor 13, a head temperature sensor 314 for detecting the temperature of the recording head, a home position sensor 310 for detecting that the carriage 2 is in the home position, and the like via the input / output port 304. Detect the output signal.

Further, the main control unit 300 receives image data, a recording mode, information on a recording medium, and the like transmitted from the host computer 315 via the interface circuit 311. The mode is a mode for specifying the recording quality such as "highest mode", "clean mode", and "standard mode". The user inputs the mode and recording medium information (size and type) on the host computer, and the information is transmitted. Further, the recording device 1 may be provided with an operation panel so that the user can input the above information from the operation panel. The number of passes at the time of recording is determined by the mode and the type of recording medium. FIG. 16 shows a correspondence table between the mode, the type of recording medium, and the number of passes. By storing this information in the ROM 302 in advance, the number of passes can be determined based on the information on the mode and the type of recording medium.

When the image data is received, the main control unit 300 performs image processing and converts it into recorded data that can be recorded by the recording device. Hereinafter, image processing will be described with reference to FIG.

The host computer 315 receives the input image data 50 from, for example, an application. Rendering processing 51 is performed on the received input image data 50 at a resolution of 1200 dpi to generate multi-value RGB data 52 for recording. In the present embodiment, the multi-valued RGB data 52 for recording has 256 values. The generated multi-value RGB data 52 for recording is transferred to the CPU 301 via the interface circuit 311.

The CPU 301 performs a color conversion process 53 on the multi-value RGB data 52 for recording to convert it into multi-value (256 value) CMYK data 54 corresponding to the CMYK color of the ink of the recording device. Next, the multi-valued CMYK data 54 is subjected to a quantization process 55 (for example, error diffusion) to binarize the multi-valued CMYK data 54 to generate binary CMYK data 56. The binary CMYK data 56 corresponding to the area to be mainly scanned is read from the RAM 303, and the binary data for each chip is generated by taking the logical product with the division mask pattern stored in the ROM 302. The mask pattern is an array of pixels that allow recording for each pixel and pixels that prohibit recording. The division mask pattern divides the binary data into data recorded by the chip 1, data recorded by the chip 2, and data recorded by the chip 3. Then, in order to divide the data into data for each of a plurality of paths, the data is divided into binary data for each path by the path mask stored in the ROM 302, and the recorded data is generated. The recording head 3 is driven according to the recorded data, and recording is performed. The processing order of the divided mask pattern and the path mask pattern may be set in a suitable order depending on the recording device.

The divided mask pattern and the pass mask pattern may be the same regardless of the ink color, or may be different for each ink color. Further, the divided mask pattern and the path mask pattern may be combined into one mask pattern, stored in the ROM 302, and processed. Further, in the present embodiment, up to the multi-valued RGB data 52 for recording is generated by the host computer 315, and the subsequent processing is performed by the main control unit 300, but the color conversion processing is also performed by the host computer. May be good. Further, although the main control unit 300 that performs image processing in the present embodiment is installed inside the recording device 1, it may be installed outside the recording device 1 so as to be able to communicate with the recording device 1.

(About the connecting part)
Next, a recording method of the connecting portions OL12 and OL23 will be described with reference to FIG. FIG. 6A shows the arrangement of the chips described in FIG. FIG. 6B is a diagram for explaining how to use the discharge port of the connecting portion. As described above, the discharge ports of the connecting portions are arranged in the X direction, and are arranged at positions where the same raster is recorded when recording. Therefore, in scanning the same recording head, the discharge port row of the non-joint portion that is not the joint portion records an image only with the discharge port row of the same chip, but the joint portion uses the discharge port row of each of the two chips. It is controlled to record an image. 6 (b-1) to 6 (b-3) are graphs showing the usage rate of the discharge port at the connecting portion. The horizontal axis corresponds to the position of the discharge port (for example, the 1193 nozzle of OL12) at the end of the connecting portion from the origin, and the axial direction from the origin corresponds to the position in the X direction. On the other hand, the nozzle usage rate on the vertical axis means the usage rate of the discharge port. Here, the usage rate of the discharge port means the sharing ratio of each chip when recording is performed at the connecting portion. The distribution method to each discharge port row may be appropriately selected. For example, a mask pattern in which the permissible recording position of each discharge port row can be used can be used. In such a case, the number of pixels assigned to each nozzle with respect to the number of pixels in the data becomes the usage rate. Although OL12 is illustrated here, it can also be applied to OL23. The solid line of the graph indicates the ejection port of the tip 1, and the dotted line indicates the ejection port of the chip 2. FIG. 6 (b-1) is referred to as a gradation joint, and the usage rate decreases as the chip approaches the end of each chip. Here, the usage rate on the non-end side is 100%, and the usage rate decreases toward the end, and becomes 0% at the end. The gradation connection can make it difficult to visually recognize the density unevenness due to the difference in the ejection characteristics between the chips by gradually changing the usage rate. Further, at the end of the ejection port row, an edge twisting phenomenon may occur in which the ink landing position is shifted to the inside of the chip due to the air flow generated by the ejection of the ink. By reducing the usage rate of the discharge port at the end of the discharge port row, it is possible to make the end twist phenomenon less likely to occur. FIG. 6 (b-2) is referred to as an even joint, and 50% each of the chip 1 and the chip 2 is uniformly used with respect to the joint region recorded at the joint. For example, it simply indicates that droplets are alternately ejected to the same raster. The ratio does not have to be 50% each. Even in the even connection, since the boundary between the chips is not clearly separated by recording the image by the ejection ports of the two chips, it is possible to make the density unevenness less visible. Further, FIG. 6 (b-3) is referred to as a switching joint, and the usage rate of the discharge port on the non-end side of the joint is 100%, and the usage rate of the discharge port on the end side is 0%. There is. The switching position does not have to be the center of the joint. Since the recording area is divided for each chip, even if the ejection characteristics are different between the chips, unevenness due to landing deviation or the like is unlikely to occur because the same chip is used for recording in each area.

FIG. 7 is a diagram for explaining a method for realizing the above-mentioned three connection methods (gradation connection, uniform connection, and switching connection). In FIG. 6, for the sake of simplicity of explanation, the number of discharge ports of the connecting portion is four. A split mask pattern is used to generate recorded data that realizes the above-mentioned connection method. As shown in the figure, the evenly connected mask pattern is a mask pattern in which the entire connecting area is evenly recorded by the chip 1 and the chip 2, and is a houndstooth in the figure. The mask pattern of the switching joint is a mask pattern that records the side of the joint that is not the end of the chip. The gradation connecting mask pattern is a mask pattern in which the chip usage rate gradually changes. Here, since the number of discharge ports at the connecting portion is as small as 4, it is a stepped mask. In the present embodiment, normally, the divided mask pattern of the connecting portion uses the mask pattern of the gradation connecting portion to generate the recorded data. When recording with a mask pattern of gradation connection, it becomes difficult to visually recognize the density difference between chips.

Next, the process of generating recorded data for ejecting ink from the recording head will be described with reference to FIG. 8 by taking an even connection as an example. Consider the case where the binary CMYK data 56 is 100% Duty for recording in all pixels. First, the binary CMYK data 56 is divided into data recorded by the chip 1 and data recorded by the chip 2 by an evenly connected division mask pattern. Next, the path mask determines whether or not the data is recorded in that path. That is, ink droplets are ejected from the nozzle of the portion where the AND of the divided mask pattern and the pass mask pattern is taken. By the above processing, it is determined that the ink is ejected at the position shown in the figure of the recording pixel in one pass.

(About multipath)
FIG. 9 is a diagram illustrating a multipath recording method using a mask. Here, the recording head 701 is a connecting head in which two rows of nozzles composed of 10 nozzles in one row are arranged. The case where the number of recording passes is 4 will be described.

In each scan, the mask pattern 702 determines the pixels to be recorded. Pixels shown in black indicate pixels that can be ejected. The mask patterns from the first scan to the fourth scan have a complementary relationship, and when the fourth scan is completed, all the pixels can be recorded. In the first scan, recording is performed by the ejection port of the first recording group, and the recording medium is conveyed by a distance corresponding to pixels for four nozzles. Next, the area recorded in the first scan is recorded by the discharge port of the second recording group. This is repeated, and when recording is performed by the discharge port of the fourth recording group, the recording of the image in that area is completed. In this way, by alternately scanning the recording head 701 and conveying the recording medium, the recording head can be scanned a plurality of times with respect to a unit area smaller than the area in which the recording head 701 can record in one scan. Make a record.

Next, as an example of performing multi-pass recording as shown in FIG. 9, when 8-pass recording is performed using the recording head 3 of FIG. 3 to complete an image in 8 passes with respect to a unit area, every 1 pass. The number of nozzles used is 3608 (total number of nozzles) ÷ 8 = 451
Will be. Nozzles used for each pass: Nozzles used for the first pass: Nos. 1 to 451 Nozzles used for the second pass: Nozzles 452 to 902 Nozzles used for the third pass: Nozzles 903 to 1353 Nozzles used for the fourth pass: 1354 Nozzles to 1804 5th pass Nozzles: 1805 to 2255 6th pass nozzles: 2256 to 2706 7th pass nozzles: 2707 to 3157 8th pass nozzles: 3158 to It will be number 3608. The relationship between the recording head and the recording area at this time is shown in FIG. 10 (a). The length of the unit region A sandwiched between the two chain lines in the figure in the Y direction is the same as the feed amount of the recording medium between the passes. It is the 3rd pass and the 6th pass that record in the unit area by the nozzle of the connecting portion. Of the nozzles that record the unit area A in the third pass, the nozzles at the connecting portion are the 1193th to 1224th nozzles from the + Y side. The pixels recorded by these nozzles are the 291-222th pixels when the + Y direction end of the unit area A is the first pixel. Of the nozzles that record the unit area in the 6th pass, the 2385th to 2416th nozzles from the + Y side are the nozzles of the connecting portion. The pixels recorded by these nozzles are the 130th to 161st pixels when the + Y direction end of the unit area A is the first pixel. In the unit area, the recorded image recorded by the connecting portion of the third pass and the recorded image recorded by the connecting portion of the sixth pass do not overlap.

On the other hand, when 8-pass recording is performed using the recording head 3 of FIG. 3 to complete an image in 6 passes for a unit area, the number of nozzles used for each pass is 3606 (total number of nozzles) ÷ 6 = 601 (? Nozzles 3607 and 3608 are not used)
Will be. Nozzles used for each pass: Nozzles used for the first pass: Nos. 1 to 601 Nozzles used for the second pass: Nozzles 602 to 1202 Nozzles used for the third pass: Nozzles 1203 to 1803 Nozzles used for the fourth pass: 1804 Nozzles Nos. 2404 Nozzles used in the 5th pass: Nozzles 2405 to 3005 Nozzles used in the 6th pass: Nozzles 3006 to 3606. The relationship between the recording head and the recording area at this time is shown in FIG. 10 (b). The length of the unit region B sandwiched between the two chain lines in the figure in the Y direction is the feed amount of the recording medium between the passes. It is the 2nd to 5th passes that the nozzle of the connecting portion is involved in the recording of the unit area B. At this time, the areas recorded by the nozzles at the joints of the 2nd and 4th passes overlap, and the areas recorded by the nozzles at the joints of the 3rd and 5th passes overlap. The nozzles at the joints where the recording areas of the nozzles at the locations indicated by T in FIG. 10B overlap. The duplication will be described in detail below.

Of the nozzles that record the unit area B in the second pass, the nozzles at the connecting portion are the 1193th to 1202nd nozzles. The pixels recorded by these nozzles are the 592nd to 601st pixels when the + Y direction end of the unit area B is the first pixel. On the other hand, among the nozzles that record the unit area B in the 4th pass, the nozzles at the connecting portion are the 2385th to 2404th nozzles. The pixels recorded by these nozzles are the 582nd to 601st pixels when the + Y direction end of the unit area B is the first pixel. Therefore, the 10 pixels 592 to 601st from the + Y direction end of the unit area B are the pixels recorded by both the nozzle of the connecting portion of the second pass and the nozzle of the connecting portion of the fourth pass.

Further, among the nozzles that record the unit area B in the third pass, the nozzles at the connecting portion are the 1203rd to 1229th nozzles. The pixels recorded by these nozzles are the 1st to 22nd pixels when the + Y direction end of the unit area B is the first pixel. On the other hand, among the nozzles that record the unit area B in the 5th pass, the nozzles at the connecting portion are the 2405th to 2416th nozzles. The pixels recorded by these nozzles are the 1st to 12th pixels when the end in the + Y direction of the unit area B is the first pixel. Therefore, the 12 pixels 1st to 12th from the end in the + Y direction of the unit area B are the pixels recorded by both the nozzle of the connecting portion of the third pass and the nozzle of the connecting portion of the fifth pass. The area surrounded by the dotted line frame in FIG. 10B is the connecting portion for recording in the same area.

Since the image is formed by ejecting ink from different chips at the recording location of the connecting portion, the fluid behavior of the ink droplet after landing is different from the recording location of the non-connecting portion. Therefore, there is a difference in the method of fixing the ink to the recording medium, which may cause uneven density. If the number of recordings at the joint is once, it is difficult to visually recognize the density unevenness due to the difference in the fixing state. However, if the recording points of the connecting portion overlap, the difference in the fixing state from the non-connecting portion may accumulate, and the density unevenness may be easily visually recognized. In the present embodiment, even when recording is performed a plurality of times in the same area by the joint portion, it is difficult to visually recognize the density unevenness due to the difference in the fixing state.

Therefore, in the present embodiment, the recording data is generated by using the gradation joint division mask pattern in which the pixels in the Y direction are recorded by the ejection ports of both chips at least once in the recording by the joint portion. Then, the recorded data is generated by using the split mask pattern of the switching joint that records the pixels in the Y direction at least once by the ejection port of one chip. Recording is performed using the recorded data generated as described above.

The method of using the nozzle when the number of multipaths is 6 will be described below. FIG. 11 is a diagram for explaining how to use the nozzle of the connecting portion when performing 6-pass recording. Further, FIG. 12 is a schematic view showing the correspondence between the nozzle and the recordable pixel. The color coding in the figure indicates which chip nozzle is selected for recording of each pixel, and the pattern formed by the pixels that can be selected in each chip is the pattern of the recording allowable pixel of the mask pattern. Corresponds to.

The nozzles of OL12 used in the second pass are the nozzles of Nos. 1193 to 1202. The data corresponding to the nozzles of the 1193 to 1202 joints is processed by the mask pattern of the gradation joint. FIG. 11 (b-1) shows the nozzle usage rate of OL12. Since the mask pattern of the gradation connection is used, the nozzle usage rate decreases toward the end of the chip. FIG. 12A-1 is a diagram showing a chip that allows recording in each pixel. The pixels shown in gray in the figure correspond to the pixels that allow recording by the nozzle of the chip 1. On the other hand, the pixels shown in black correspond to the pixels that allow recording by the nozzle of the chip 2. Further, as shown in FIG. 11 (b-3), an evenly connected mask pattern in which nozzles are used evenly may be used. FIG. 12 (a-3) is a diagram showing a chip that allows recording to each pixel when a mask pattern of even connection is used.

The nozzles of OL23 used in the 4th pass are the nozzles Nos. 2385 to 2404. FIG. 11 (b-2) shows the nozzle usage rate of OL23. Of the nozzles used in the 4th pass, the area recorded by the nozzles Nos. 2385 to 2394 does not overlap with the area recorded by the nozzles of the OL12 in the second pass. Therefore, the data corresponding to the nozzles Nos. 2385 to 2394 are processed by the mask pattern of the gradation connection. Since the nozzles recorded by the nozzles 2395 to 2404 overlap with the area recorded by the nozzles of OL12 in the second pass, the data corresponding to the nozzles 2395 to 2404 is processed by the mask pattern of the switching connection. As shown in FIG. 11 (b-2), all the regions corresponding to Nos. 2395 to 2404 are recorded by the nozzle of the chip 3. FIG. 12 (a-2) is a diagram showing a chip that allows recording of each pixel corresponding to the usage rate of FIG. 11 (b-2). Here, the pixels recorded by the 2385th to 2394th joints are recorded by the recording data using the gradation mask. Therefore, among the pixels corresponding to the 2385th to 2394th nozzles, the pixels close to the pixels corresponding to the 2395th to 2416th nozzles are more pixels recorded by the nozzle of the chip 3. Therefore, when the pixels corresponding to the nozzles Nos. 2395 to 2416 are recorded by the nozzles of the chip 3, it is difficult to visually recognize the density difference from the pixels corresponding to the nozzles Nos. 2385 to 2394. For example, when the area recorded by all the nozzles of the connecting portion OL23 overlaps the area recorded by the OL12, recording is performed by the chip 2 and the chip 3 as in the mask pattern of the switching connection shown in FIG. May be good. Further, as shown in FIG. 11 (b-4), the nozzles Nos. 2385 to 2394 may use a mask pattern of evenly connected joints. FIG. 12 (a-4) is a mask pattern corresponding to the usage rate of FIG. 11 (b-4).

As described above, for the region where recording is performed multiple times by the joint portion, a mask pattern of gradation connection or uniform connection is used once to make it difficult to visually recognize the density unevenness due to the variation in the ejection characteristics between the chips. .. Then, once again, the recorded data is generated by using the mask pattern of the switching joint in order to make it difficult to visually recognize the density unevenness due to the difference in the fixing state of the ink between the non-joint portion and the joint portion. By doing so, it is possible to make it difficult to visually recognize both the density unevenness due to the difference in discharge characteristics and the density unevenness due to the difference in the fixing state.

Further, in the above description, the mask pattern of the gradation connection is used in the second pass, and the mask pattern of the switching connection is used in the fourth pass. However, the order of use may be reversed, and the mask pattern of the switching connection may be used in the second pass, and the mask pattern of the gradation connection may be used in the fourth pass. However, it is possible to make it more difficult to visually recognize the density unevenness due to the variation in the ejection characteristics by using the mask pattern of the gradation connection or the mask pattern of the uniform connection on the side where the area to be recorded by the joint portion is wide.

In the present embodiment, the mask can be determined according to the number of passes to be recorded. When generating recorded data from the information of the number of passes according to the input of the setting from the user, it is determined whether or not the same area is recorded by the connecting portion, and the connecting portion OL12 and OL23 are divided according to the determination result. Determine the mask pattern.

In the case of the above-mentioned 8-pass recording, since the predetermined area is not recorded a plurality of times by the connecting portion, the recording data is generated by using the mask pattern of the gradation connecting in each of the divided mask patterns.

(flowchart)
Next, the process of selecting the mask pattern described so far is shown in the flowchart of FIG. This process is, for example, a process of expanding the program stored in the ROM 302 into the RAM 303 and executing the program by the CPU 301. This process starts in response to the main control unit 300 acquiring image data from the host computer 315. The main control unit 300 acquires information on the recording mode and the type of recording medium specified by the user as well as the image data. The acquired image data and mode are stored in the RAM 303. The number of passes corresponding to the modes is predetermined and is stored in the ROM 302. In addition, the split mask pattern used for the connecting portion is set to the mask pattern of the gradation connecting by default.

First, in step S101, the mode and recording medium type information stored in the RAM 303 is acquired. Then, in step S102, the number of passes at the time of recording is determined from the correspondence between the mode stored in the ROM 302, the type of recording medium, and the number of passes.

Next, in step S103, the area to be recorded by the connecting portion is obtained from the number of passes determined in step S102 and the information of the connecting portion of the recording head 3 stored in the ROM or the like as fixed information. In step S104, it is determined whether or not there is an area in which the connecting portions are duplicated and recorded. If there is no overlapping area, the mask pattern of the gradation connection is used for the connection part, so the process ends without changing. When there is an overlapping area, in step S105, the image data corresponding to the overlapping nozzles of the connecting portion used in one recording is changed to use the mask pattern of the switching connecting, and the processing is performed. finish.

When the mask pattern used in the above processing is set, the image data is processed using the set mask pattern and the recorded data is generated.

In the present embodiment, the recording head in which three chips are connected has been described, but the present invention can be applied to, for example, a recording head in which two chips are connected or a recording head in which four or more chips are connected. Further, since the division mask pattern to be used can be set in advance if the number of passes and the position of the connecting portion are known, the preset one is stored in the ROM 302, and the image data is processed according to the mode. You may want to get the settings.

Further, the number of times that the connecting portion records in the same area is twice in the above description, but the present embodiment can be applied even when the number of times is three or more. In that case, prepare one pass for applying the gradation or even connection to the nozzle of the joint for recording the same area, and one pass for applying the switching connection. Other than that, when the reduction of density unevenness due to the variation in ejection characteristics between chips is emphasized, a mask pattern of gradation connection is often used. Further, when the reduction of density unevenness due to the difference in the fixing state of the ink between the non-joint portion and the joint portion is emphasized, the mask pattern of the switching joint is often used. By doing so, it is possible to make it more difficult to visually recognize the density unevenness than in the case of recording using the gradation or the mask pattern of evenly connected in all the scans of the number of times that the joint portion records in the same area. ..

Further, in the present embodiment, it is described that all image formation is completed in a specified number of passes, but depending on the recording device, at the recording start portion (tip) or the recording final portion (rear end) of the recording medium. , There is a process that reduces the feed amount of the recording medium. This is done in order to prevent image deterioration due to the feed amount error in the case of a device in which the feed amount error at the front and rear ends tends to be large due to mechanical factors. However, even for such processing, since the feed amount information can be obtained by analyzing the mode, the overlap of the joints between the paths is checked after considering the feed amount processing at the front and rear ends, and each joint is connected. The nozzle usage rate of the unit can be determined.

(Second Embodiment)
In the first embodiment, the division mask pattern to be used is changed regardless of the number of passes. In this embodiment, a mode in which the division mask pattern is not changed when the number of passes is larger than a predetermined number will be described. The description of the same as that of the first embodiment will be omitted.

When the number of passes is large, the data is divided into smaller pieces, and the density of ink recorded in one scan becomes low. Therefore, the probability that the inks stick to each other is low, and the density unevenness due to the difference in the fixing state of the inks between the non-joint portion and the joint portion is less likely to occur. Therefore, when recording is performed with a number of passes larger than a predetermined number of passes, the divided mask pattern is not changed, and the recorded data is generated and recorded using the mask pattern of the gradation connection.

FIG. 14 shows a flowchart of the process of selecting the mask pattern of the present embodiment. This process is, for example, a process of expanding the program stored in the ROM 302 into the RAM 303 and executing the program by the CPU 301. This process starts in response to the main control unit 300 acquiring image data from the host computer 315. The main control unit 300 acquires information on the recording mode and the type of recording medium specified by the user as well as the image data. The acquired image data and mode are stored in the RAM 303. The number of passes corresponding to the modes is predetermined and is stored in the ROM 302. In addition, the divided mask pattern used for the connecting portion is set to the mask pattern of the gradation connecting by default.

Steps S201 to S202 perform the same processing as steps S101 to S102 of FIG. 13 of the first embodiment.

In step S203, it is determined whether or not the number of passes acquired in step S202 is equal to or greater than the predetermined number of passes. The predetermined number of passes N is preset and stored in the ROM 302. If the number of passes is N or more, the division mask pattern is not changed, so the process ends. If the number of passes is not N or more, the division mask pattern may be changed, so the process proceeds to step S204.

Steps S204 to S206 perform the same processing as steps S103 to S105 of FIG. 13 of the first embodiment, and change the division mask pattern when there is an area where the recordings by the connecting portions overlap.

According to the above processing, when density unevenness due to the difference in the fixing state of the ink between the non-joint portion and the joint portion is unlikely to occur, the density due to the variation in the ejection characteristics between the chips is obtained by using the mask pattern of the gradation joint. It is possible to further suppress unevenness.

(Third Embodiment)
In the present embodiment, the process of selecting the divided mask pattern is performed by further adding the information on the type of the recording medium to the second embodiment. The easiness of visually recognizing density unevenness differs depending on the type of recording medium. If the density unevenness is not a type of recording medium that is easily visible, the density unevenness due to the difference in the fixing state of the ink between the non-joint portion and the joint portion is difficult to be visually recognized. Therefore, the division mask pattern is not changed.

FIG. 15 shows a flowchart of the process of selecting the mask pattern of the present embodiment. This process is, for example, a process of expanding the program stored in the ROM 302 into the RAM 303 and executing the program by the CPU 301. This process starts in response to the main control unit 300 acquiring image data from the host computer 315. The main control unit 300 acquires information on the recording mode specified by the user and the recording medium used for recording as well as the image data. The acquired image data, mode, and recording medium type information are stored in the RAM 303. The number of passes corresponding to the modes is predetermined and is stored in the ROM 302. In addition, the divided mask pattern used for the connecting portion is set to the mask pattern of the gradation connecting by default.

Steps S301 to S303 perform the same processing as steps S201 to S203 of FIG. 14 of the second embodiment.

In step S304, it is determined whether or not the type of recording medium acquired in step S301 is a type of recording medium in which density unevenness is easily visible. In the determination, the type of recording medium in which the density unevenness is easily visually recognized is stored in the ROM 302 in advance, and when the type of the recording medium acquired in step S304 is stored in the ROM 302, it is determined that the density unevenness is easily visible. .. If it is determined that the density unevenness is not a recording medium that is easily visible, the division mask pattern is not changed, so the process is terminated. If it is determined that the recording medium has density unevenness that is easily visible, the process proceeds to step S305.

Steps S305 to S307 perform the same processing as steps S204 to S206 of FIG. 14 of the second embodiment, and change the division mask pattern when there is an area where the recordings by the connecting portions overlap.

According to the above processing, the division mask pattern can be changed only when the density unevenness is easily visually recognized, and the processing time can be shortened when the change is not performed.

1 Recording device 3 Recording head 300 Main control unit 301 CPU
302 ROM
303 RAM
315 host computer

Claims (15)

A plurality of ejection port rows for ejecting ink are arranged along a predetermined direction, and a connecting portion is formed in which the ends of the ejection port rows intersect with each other in the predetermined direction. A recording head in which the discharge port rows are arranged so as to be offset from each other in the predetermined direction.
A scanning means for scanning the recording head in the crossing direction, and
A control means for controlling the recording operation so that the scanning means ejects ink from the recording head while moving the recording head in the crossing direction to record an image on a recording medium.
It is a recording device having
In the control means, the recording by at least one scan of the scans for recording by the joint portion with respect to the predetermined region which is the region where the ink is ejected a plurality of times by the ejection port of the joint portion is the predetermined region. Pixels to be recorded in the intersection direction of the region are recorded by the discharge ports of both discharge port rows forming the joint portion, and at least the other scan in which recording is performed by the joint portion for the predetermined region. Recording by one scan is characterized in that pixels to be recorded in the crossing direction of the predetermined region are recorded by the discharge port of one of the discharge port rows forming the joint portion. Recording device. The control means describes the ejection port of the joint portion that ejects ink to the predetermined region in recording by at least one scan of the scans that record the predetermined region by the joint portion. The recording head is such that the number of times ink is ejected by the ejection port on the end side of the ejection port row is smaller than the number of times ink is ejected by the ejection port on the side other than the end of the ejection port row in the direction. The recording device according to claim 1, wherein the recording apparatus is controlled. When the control means records a region for recording by ejecting ink once by the ejection port of the joint portion, both pixels forming the joint portion form pixels to be recorded in the intersecting direction of the region. The recording device according to claim 1 or 2, wherein the recording is performed by the discharge port of the discharge port row. It has a pass number acquisition means for acquiring the number of passes which is the number of times the scanning means scans in order to record an image in the area scanned by the scanning means.
When the number of passes acquired by the pass number acquisition means is equal to or greater than the predetermined number of passes, the control means has the crossing direction of the predetermined region in all scans for recording the predetermined region by the connecting portion. The recording device according to any one of claims 1 to 3, wherein the pixels to be recorded in the above are recorded by the discharge ports of both discharge port rows forming the joint portion. The recording device according to claim 4, wherein the pass number acquisition means acquires the number of passes based on information indicating the quality of the record. The recording device according to claim 4 or 5, wherein the pass number acquisition means acquires the number of passes based on information on the type of recording medium for recording by the recording head. It has a type acquisition means for acquiring information on the type of recording medium for recording.
When the type of the recording medium indicated by the information on the type of the recording medium acquired by the type acquisition means is set so that density unevenness is easily visible, the control means is determined by the connecting portion. In all scans for recording the region, the recording head is controlled so that the pixels to be recorded in the intersecting direction of the predetermined region are recorded by the discharge ports of both discharge port rows forming the joint portion. The recording device according to any one of claims 1 to 6, characterized in that. The control means records the pixels recorded in the crossing direction of the predetermined region by scanning the scan of the scan recording the predetermined region, whichever has the larger number of discharge ports of the joints used for recording. The recording device according to any one of claims 1 to 7, wherein the recording head is controlled so as to record by the discharge ports of both discharge port rows forming the joint portion. In the scan for recording the predetermined area, the control means records the pixels recorded in the intersecting direction of the predetermined area in the discharge port of one of the discharge port rows forming the joint portion. In the scan recorded by, the pixels in the intersecting direction of the region to be recorded by the discharge port of the joint portion for recording the region other than the predetermined region are recorded by the discharge ports of both discharge port rows forming the joint portion. The recording device according to any one of claims 1 to 8, wherein the recording head is controlled. The control means measures the pixels to be recorded in the intersecting direction of the predetermined region in the predetermined region in a scan in which the pixels are recorded by the discharge port of one of the discharge port rows forming the joint portion. Any of claims 1 to 9, wherein the recording head is controlled so that the pixels to be recorded are recorded by the discharge port of one of the discharge port rows forming the joint portion. The recording device according to item 1. The control means captures pixels recorded in the crossing direction of the predetermined region by the discharge port of one of the discharge port rows forming the joint portion in the scanning of the predetermined region. The portion is recorded by a predetermined number of discharge ports from the non-end side of the one discharge port row, and the remaining area of the predetermined region is recorded by the discharge port of the other discharge port row. The recording device according to any one of claims 1 to 10, wherein the recording head is controlled. In the scan for recording the predetermined area, the control means records the pixels recorded in the intersecting direction of the predetermined area in the discharge port of one of the discharge port rows forming the joint portion. In the scanning recorded by, if there is a discharge port of the joint portion for recording the region other than the predetermined region, the discharge port for recording the predetermined region is closer to the discharge port not the joint portion. The recording device according to claim 10, wherein the recording head is controlled so as to record all the pixels in the predetermined region by the discharge port of the above. It has a generation means for generating recorded data for recording an image by using a mask pattern for determining the permission or prohibition of recording for each pixel.
The generation means determines a mask pattern used for generating recorded data for recording by the discharge port of the joint portion based on the number of passes acquired by the acquisition means, and records the predetermined area by the joint portion. In the recording by at least one scanning, the pixels to be recorded in the crossing direction of the predetermined area are recorded by the discharge ports of both discharge port rows forming the joint portion, and are recorded in the predetermined area. On the other hand, in the recording by at least one scanning while recording by the joint portion, the pixels recorded in the intersection direction of the predetermined region are recorded in one of the discharge port rows forming the joint portion. Generate the recorded data to be recorded by the discharge port of the discharge port row,
The recording device according to any one of claims 1 to 12, wherein the control means controls the recording head so that recording is performed according to the recording data generated by the generation means. The recording device according to any one of claims 1 to 13, wherein the recording head has three discharge port rows and is arranged so that two connecting portions are formed. A plurality of ejection port rows for ejecting ink are arranged along a predetermined direction, and a connecting portion is formed in which the ends of the ejection port rows intersect with each other in the predetermined direction. The recording heads are arranged so that the ejection port rows are displaced from each other in the predetermined direction, and the recording medium is ejected while being scanned on the recording medium in a direction intersecting the predetermined direction by the scanning means. It is a recording method that records images in
The recording by at least one scan of the scans for recording by the joint portion with respect to the predetermined region which is the region where the ink is ejected a plurality of times by the ejection port of the joint portion is the crossing direction of the predetermined region. The pixels to be recorded in are recorded by the discharge ports of both discharge port rows forming the joint portion, and by at least one other scan of the scans in which the joint portion records the predetermined area. Recording is a recording method characterized in that pixels to be recorded in the crossing direction of the predetermined region are recorded by a discharge port of one of the discharge port rows forming the joint portion.

Images