JP2008296562A - Recording device and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output an image of high quality even in the case of reducing the range of a recording element used for recording by the recording of tip-and-rear ends from the recording of the central part of a recording medium. <P>SOLUTION: Second masks used in the case of recording to the tip-and-rear ends of the recording medium are created of first masks used for recording to the central part. More particularly, the second masks connected to each other by suitably abstracting data of the recording permission rate of the first mask are created, so that an abrupt bump is not developed in the distribution of a recording permission rate in a recording element arranging direction. Thus, in the case of reducing the range of the recording element by the recording of the tip-and-rear ends as compared with the recording of a recording medium central part, images of the quality of the same degree as that of the central part can be outputted at the-tip-and rear ends of the recording medium. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a recording method for performing recording by applying a recording agent (for example, ink) to a recording medium.

  Recently, OA devices such as personal computers and word processors are widely used, and various recording devices for recording information output from these devices on various recording media are provided. In particular, the ink jet recording apparatus has various advantages such as low noise, low running cost, small size, and relatively easy colorization, and is accepted by a wide range of users. In recent years, in particular, there has been an increasing demand for outputting images taken with a digital camera with the same quality as a silver halide photograph, and a recording method incorporating various ideas for responding to this has been implemented.

  For example, a recording medium that does not leave a margin at the edge such as the leading edge or the trailing edge of the recording medium (hereinafter, “marginless recording”) has been commercialized and has become widespread. However, at the leading edge or the trailing edge of the recording medium, the recording medium conveyance accuracy tends to decrease due to the configuration of the recording apparatus. Therefore, an ink jet recording apparatus that employs a special recording method at the front end portion or the rear end portion of the recording medium has already been provided.

  Furthermore, a recording apparatus that employs a recording method called “multi-pass recording” in order to output a smoother image that matches the picture quality is now common. “Multi-pass printing” In the same image area, printing is executed by a plurality of printing scans according to a mask pattern that defines a complementary pixel arrangement.

  Hereinafter, specific configurations of “front and rear end recording” and “multi-pass recording” will be described.

(Recording on the front and rear ends)
In general, when recording the leading end or the trailing end of a recording medium, the image tends to be distorted. This is mainly due to a situation in which the recording medium comes off from some of the plurality of rollers that support and convey the recording medium on the upstream side and downstream side of the recording position. Hereinafter, such a state will be described in detail with reference to the drawings.

  FIG. 8 is a diagram schematically illustrating the recording head, the recording medium, and a transport mechanism that transports the recording medium in a state where the central portion of the recording medium is being recorded. In the figure, a transport roller M3060 on the upstream side in the transport direction and two discharge rollers M3100 and M3110 on the downstream side cooperate with a pinch roller M3070 and two spurs M3120 and M3120, respectively. That is, three sets of nip portions are formed and the recording medium P is nipped and conveyed.

  H1000 is a recording head cartridge having a recording head in which a plurality of recording elements (nozzles) for ejecting ink are arranged at a predetermined pitch in a direction parallel to the conveying direction in the figure. The recording head cartridge H1000 discharges ink from each recording element while moving and scanning in a direction orthogonal to the drawing, and the image is applied to the area of the recording medium P located between the transport roller M3060 and the discharge roller M3100. Form. Images are sequentially formed on the recording medium P by alternately repeating the recording scanning by the recording head cartridge H1000 and the conveying operation of the recording medium P by the three roller pairs.

  FIG. 9 is a diagram showing a state in which recording further proceeds from the state of FIG. 8 and recording is performed on the vicinity of the rear end portion of the recording medium P. The recording medium P has already been removed from the transport roller M3060 and is transported only by the rotation of the discharge rollers M3100 and M3110.

  In general, there are many differences in roller diameter and conveyance accuracy between the conveyance roller M3060 and the discharge rollers M3100 and M3110 due to differences in their main roles. The transport roller M3060 has a main role of positioning the recording medium at an appropriate position with respect to the recording head for each recording scan. Therefore, it has a sufficiently large roller diameter, and can perform a conveying operation with a desired accuracy. On the other hand, the discharge rollers M3100 and M3110 have a main role of reliably discharging the recording medium after recording. Therefore, the roller diameter is small and the conveyance accuracy of the recording medium is often inferior compared to the conveyance roller M3060. Accordingly, compared to the previous area, the conveyance accuracy is higher for the area from when the trailing edge of the recording medium P is removed from the conveying roller M3060 until the recording of the last edge of the recording medium P is completed. A deteriorating situation will occur. At this time, when the carry amount is insufficient, the image forming portion between adjacent recording scans overlaps so-called “black streaks”. Conversely, when the carry amount is too large, the image forming portion between print scans is The so-called “white streaks” may be confirmed by moving away. Depending on the image to be recorded, this is a bad image effect that cannot be ignored.

  In addition, image defects due to the fact that both ends of the recording medium are not held also occur. When the rear end portion of the recording medium P deviates from the conveyance roller M3060, the distance between the recording head and the recording medium (hereinafter referred to as the inter-paper distance) fluctuates not a little, and then becomes unstable. The recording head cartridge H1000 performs recording scanning while ejecting ink at a timing corresponding to a predetermined inter-paper distance maintained by the front and rear rollers. The ink ejected at an appropriate timing becomes dots on the recording medium, and an image is formed by arranging the ink at an appropriate pitch. Therefore, if the inter-paper distance changes during recording, or if the inter-paper distance variation within the recording width is large, the dot position on the recording medium will also become unstable, and white, black, or rough. Such a bad image occurs.

  Such a problem of the inter-paper distance occurs similarly when recording not only the rear end portion of the recording medium but also the front end portion.

  FIG. 10 is a diagram showing a state in which recording is performed on the vicinity of the front end of the recording medium P. In this state, the recording medium P is held and transported only by the upstream transport roller M3060 and the pinch roller M3070. In other words, when the leading end is recorded, the discharge rollers M3100 and M3110 are not involved in transporting the recording medium P. Compared to the state in which the vicinity of the rear end portion described in FIG. 9 is recorded, it can be said that the conveyance is performed with high accuracy. However, the problem of the inter-paper distance due to the fact that the leading edge of the recording medium P is not held occurs as in the state of FIG. That is, the dot position accuracy on the recording medium becomes unstable as compared with the recording at the center of the recording medium (the state shown in FIG. 8), and image quality degradation such as white stripes, black stripes, or rough feeling occurs.

  The following countermeasures are taken in the serial type recording apparatus in which the image quality is particularly emphasized against the adverse effects of the image that may occur at the time of recording at the leading edge and the trailing edge of the recording medium as described above (for example, Patent Documents). 1). That is, when recording at the front and rear end portions, the recording width of the recording head (that is, the range in which the recording elements are actually ejected in a range that is involved in recording) is limited (reduced), and the recording medium is recorded accordingly. This is a method of reducing the transport amount. By narrowing the recording width of the recording head, it is possible to suppress fluctuations in the inter-paper distance within the recording width. In this case, if multi-pass printing, which will be described later, is performed, the effect is also exhibited against roughness. Even in a situation where the conveyance accuracy is lowered, the conveyance error can be reduced by reducing the conveyance amount of the recording medium. Further, coupled with the fact that the pitch of the connecting portions of the image forming portions between adjacent recording scans becomes fine, there is also an effect that white stripes and black stripes become inconspicuous. Furthermore, it is more effective to use so-called multi-pass printing in which an image is formed by performing printing scanning a plurality of times for the same area on the printing medium, and an effect on roughness is also expected.

  Also, an ink jet recording apparatus that employs an interlace recording method that uses a recording head in which the arrangement density of recording elements is lower than the recording density and completes an image while interpolating the recording density in the sub-scanning direction by a plurality of recording scans. The same countermeasures are also taken at. That is, the number of recording elements that actually eject ink only at the front and rear ends is suppressed, and the conveyance amount of the recording medium is adjusted accordingly (for example, Patent Document 2).

(About multi-pass recording method)
Next, a multipass recording method will be described.

  FIG. 11 schematically shows a recording head and a recording pattern in order to explain the multipass recording method. The recording head H1001 actually has a large number of recording elements (nozzles), but here it will be described as having 16 nozzles for simplicity. As shown in the drawing, the nozzles are divided into first to fourth nozzle groups, and each nozzle group includes four nozzles. The mask P0002 is composed of first to fourth mask patterns P0002 (a) to P0002 (d). The first to fourth mask patterns P0002 (a) to P0002 (d) define areas where the first to fourth nozzle groups can be recorded. The black area in the mask pattern indicates a recording allowable area, and the white area indicates a non-recording area. The first to fourth mask patterns P0002 (a) to P0002 (d) are complementary to each other, and when these four mask patterns are overlapped, recording of a region corresponding to a 4 × 4 area is completed. It has become.

  Here, in the mask pattern, the recording allowance is determined as follows. The recording allowable ratio is a percentage of the number of recording allowable areas to the total number of recording allowable areas (black areas) and non-recording allowable areas (white areas) constituting the mask pattern. That is, if the mask pattern recording allowable area is m and the non-recording allowable area is n, the mask pattern recording allowable ratio (%) is m / (m + n) × 100.

  Each pattern indicated by P0003 to P0006 in FIG. 11 shows a state in which an image is completed by overlapping recording scans. At the end of each printing scan, the printing medium is conveyed by the width of the nozzle group (four nozzles in this figure) in the direction of the arrow in the figure. Therefore, the same area of the recording medium (area corresponding to the width of each nozzle group) is configured such that an image is completed only after four recording scans. As described above, the formation of each same area of the recording medium by a plurality of nozzle groups by a plurality of scans has an effect of reducing variations peculiar to the nozzles and variations in the conveyance accuracy of the recording medium. Further, by devising the arrangement of the mask pattern, it is possible to take measures against other various image problems and reliability problems of the printing apparatus.

  For example, as in recent years, in an inkjet recording head that ejects a large number of small droplets at a high frequency, the ink ejection direction from nozzles located at the end of the recording head is deflected toward the inside of the nozzle array. There is a tendency to end up. In this case, since the dots to be formed by the nozzles located at the end of the nozzle row are formed at positions inside the nozzle array that deviate from the normal positions, the white stripes (hereinafter referred to as pitches) of the recording width of the recording head. , Referred to as “edge streaks”). Even in such a situation, the edge streaks can be made inconspicuous by devising the arrangement of the mask pattern described above (see, for example, Patent Document 3).

  FIG. 12 is a diagram showing an example of a mask that is employed to reduce the edge streaks. The black area of the mask in FIG. 12 is a portion that plays the same role as the black area of the mask in FIG. 11, and indicates an area that allows recording. The white area of the mask in FIG. 12 is a part that plays the same role as the white area of the mask pattern in FIG. In this example, a case where a recording head having 1280 nozzles is used and 4-pass multi-pass printing is performed is shown as an example. As in the case of FIG. 11, all 1280 nozzles are divided into four groups of 320 nozzles. Here, the print allowance ratio (the black area and the white area constituting the mask pattern is determined depending on the position of the nozzles. It can be seen that the ratio of the number of black areas to the total number is different.

  Here, the printing allowance of the mask pattern corresponding to each of the first nozzle group and the fourth nozzle group is N%, and the printing allowance of the mask pattern corresponding to each of the second nozzle group and the third nozzle group is M. (However, M> N)%. The sum (N + M + M + N) of the mask pattern recording allowances corresponding to these four nozzle groups is 100%. Further, even within each nozzle group or the same nozzle group, the distribution of the print allowance is biased depending on the region, and the print allowance at the central portion is set to be relatively high, while the print allowance gradually decreases toward the end. This is a mask (called a gradation mask).

  It has been confirmed that the above-described deflection in the ejection direction becomes more noticeable as smaller droplets of ink are ejected at higher speed and higher density. Therefore, setting the recording allowance rate at the end portion to be lower than that at the central portion can alleviate the deflection tendency of the ink ejected from the nozzle located at the end portion. Even if there is a slight tendency to deflection, since the number of dots to be formed itself is reduced, the effect of making the end stripe due to the landing position deviation inconspicuous is also obtained.

  In an ink jet recording apparatus that places importance on photographic image quality, a small amount of droplets, a high density recording element, and a high driving frequency are important factors in achieving both image quality and recording speed. Therefore, the mask pattern as shown in FIG. 5 is a generally useful configuration in recent inkjet recording apparatuses that place importance on photographic image quality.

JP 2004-98668 A JP 11-291506 A JP 2002-096455 A JP 2002-144737 A JP-A-6-330616 JP 2002-144522 A

  As described above, the recording quality can be improved by limiting the range (nozzle use range) of the nozzle arrangement that is involved in recording when recording the front and rear end portions, and reducing the conveyance amount of the recording medium accordingly. . If multi-pass printing is used in combination, it is more effective and an effect on roughness is also expected. However, when the nozzle use range is changed between the recording at the central portion of the recording medium and the recording at the front and rear end portions, and the multipass printing is realized in each range, the size of the nozzle use range is different. Must be switched. A configuration for performing such switching is also disclosed in Patent Document 4.

  Here, it is conceivable to separately prepare a mask (first mask) applied to recording in the central portion of the recording medium and a mask (second mask) applied to recording of the front and rear end portions. However, in general, a mask is applied when recording, in which data defining its configuration pattern is fixedly stored in a memory such as a ROM. For this reason, preparing the first mask and the second mask separately leads to an increase in memory capacity. In particular, recently, there are recording apparatuses that can change the number of passes during multi-pass recording according to the type of recording medium used for recording and the mode for specifying the recording quality desired by the user. The mask is prepared. In addition, considering switching between the first mask and the second mask leads to a further increase in memory capacity.

  Therefore, for example, it is conceivable that only the first mask is prepared as the mask, and the second mask is generated based on the first mask and used. In this case, data is extracted from the first mask prepared corresponding to the nozzle range used for recording at the central portion of the recording medium, corresponding to the nozzle range used for recording at the front and rear end portions. It is conceivable to generate two masks.

  However, the present inventors have found that if such extraction is not properly performed, a step having a large recording allowance occurs at the joint of the mask pattern corresponding to each of the nozzle groups divided in the reduced use range. Thus, the present inventors have found that the image quality is deteriorated due to this.

  The present invention relates to a printing apparatus capable of performing multipass printing using different printing element usage ranges and applying different masks according to the size, and extracting another mask from one mask. The purpose is to maintain the recording quality even when applied.

For this purpose, the present invention provides a recording scan in which a recording head having an array of recording elements scans a recording medium in a direction different from the direction of the array, and a direction intersecting the direction of the recording scan. Recording that can be performed by performing the recording scan a plurality of times in accordance with a pixel arrangement that is complementary to the same image area. A device,
First recording using a recording element group included in a relatively wide first range from the array of recording elements, and second recording using a recording element group included in a relatively narrow second range from the array of recording elements And setting means capable of setting
A first mask that is applied to define the pixel array when the first recording is performed, and the first mask having a nonuniform distribution of the recording allowance in the direction of the array is fixed to perform the definition. Storage means for storing automatically,
Extracting means for extracting the data of the recording allowance ratio from the stored first mask and serving as a second mask to be applied to define the pixel arrangement when executing the second recording;
And the extraction means performs extraction so that the recording allowance of the second mask changes monotonously along the direction of the array.

The present invention also provides a recording scan for recording while a recording head having an array of recording elements is scanned with respect to a recording medium in a direction different from the direction of the array, and a direction intersecting the direction of the recording scan. A recording method capable of recording an image by conveying the recording medium and performing recording by a plurality of recording scans according to a pixel arrangement complementary to the same image area Because
First recording using a recording element group included in a relatively wide first range from the array of recording elements, and second recording using a recording element group included in a relatively narrow second range from the array of recording elements And a setting process capable of setting
A first mask that is applied to define the pixel array when the first recording is performed, and the first mask having a nonuniform distribution of the recording allowance in the direction of the array is fixed to perform the definition. Reading the stored first mask from the storage means for storing the first mask and applying it to the first recording;
Extracting the data of the recording allowance ratio from the first mask and extracting it as a second mask applied to define the pixel arrangement when performing the second recording;
The extraction step is characterized in that the extraction is performed so that the recording allowance of the second mask changes monotonously along the direction of the arrangement.

  In the present invention, in the recording apparatus capable of performing the first and second multi-pass recording using different first and second masks depending on the size of the recording element use range, The print allowance ratio data is extracted from the first mask to be the second mask. At this time, by performing extraction so that the recording allowance rate of the second mask changes monotonously along the direction of the arrangement, the second multipass recording maintaining the same recording quality as the first multipass recording is performed. realizable.

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

(1) Device Configuration FIG. 1 is a schematic perspective view showing the overall configuration of an ink jet recording apparatus according to an embodiment of the present invention. At the time of recording, the recording medium P is sandwiched between a conveying roller 1 that is one of a plurality of rollers provided on the conveying path and a pinch roller 2 that is driven by the recording medium P. 3 is conveyed in the direction A intersecting the direction of recording scanning while being guided and supported on the upper side. A pinch roller 2 is elastically urged against the conveying roller 1 by pressing means such as a spring (not shown). The transport roller 1 and the pinch roller 2 constitute constituent elements of the upstream transport means (first transport means).

  The platen 3 is provided at a recording position facing the surface (ejection surface) on which the ejection port of the recording head 4 in the form of an ink jet recording head is formed, and supports the back surface of the recording medium P so that the surface of the recording medium P The distance from the discharge surface is maintained at a constant or predetermined distance.

  The recording medium P that has been transported and recorded on the platen 3 is then sandwiched between a rotating discharge roller 12 and a spur 13 that is a rotating body that is driven by the recording roller P, and is transported in the A direction. To the discharge tray 15. These discharge rollers 12 and spurs 13 constitute constituent elements of the downstream conveying means (second conveying means). In FIG. 1, only one pair of the discharge roller 12 and the spur 13 is shown, but two pairs may be provided as shown in FIGS.

  14 is a member that is disposed on one side of the recording medium, serves as a conveyance reference when conveying the recording medium, and also serves to restrict the recording medium P from floating upward, that is, toward the ejection surface of the recording head 4. It is.

  The recording head 4 is detachably mounted on the carriage 7 with its discharge surface facing the platen 3 or the recording medium P. The carriage 7 is reciprocated along the two guide rails 5 and 6 by a motor as a driving means, and the recording head 4 can perform an ink ejection operation in the course of the movement. This carriage movement direction is a direction orthogonal to the recording medium conveyance direction (arrow A direction) and is called a main scanning direction. On the other hand, the recording medium conveyance direction is called a sub-scanning direction. Then, recording on the recording medium P is performed by alternately repeating main scanning (recording scanning) of the carriage 7 or the recording head 4 and conveyance (sub-scanning) of the recording medium.

  Here, the recording head 4 is provided with means (for example, a heating resistance element) that generates thermal energy as energy used for ink ejection, and causes a change in ink state (film boiling) by the thermal energy. The nozzle can be used. Further, an element that generates mechanical energy such as a piezo element may be used as the energy generating means, and a system that ejects ink using the mechanical energy may be used.

  A plurality of nozzles are arranged in a direction different from the main scanning direction, for example, in the sub-scanning direction. With such a head configuration, it is possible to execute so-called one-pass printing in which printing on the same area on the printing medium is completed by one main scanning. However, so-called multi-pass printing, in which printing in the same scanning area on the printing medium is completed by a plurality of main scans in order to reduce nozzle variations and improve printing quality, can also be performed. The number of passes at the time of multi-pass recording can be appropriately determined according to the recording mode and other conditions.

  A plurality of independent ink tanks are detachably attached to the recording head 4 according to the color of the ink to be used. Alternatively, ink may be supplied from an ink tank provided at a fixed portion of the apparatus via a liquid supply tube.

  The recovery unit 11 can face the ejection surface of the recording head 4 in a non-recording area within the movable range of the recording head 4 in the main scanning direction and outside the side edge of the recording medium P or the platen 3. Is arranged. The recovery unit 11 has a known configuration as described below. That is, a cap portion for capping the ejection surface of the recording head 4, a suction mechanism for forcibly sucking ink from the recording head 4 in a state where the ejection surface is capped, and a cleaning blade for wiping off dirt on the ink ejection surface.

  FIG. 2 is a diagram illustrating the regions of the front end, the center, and the rear end when the marginless recording is performed on the recording medium of A4 size (294 mm × 210 mm) with the recording apparatus of the present embodiment. That is, as described with reference to FIGS. 8 to 10, an area where recording can be performed with the recording medium held by both the transport roller 1 and the discharge roller 12 is a central portion. In addition, a recording area before the leading edge of the recording medium is supported by the discharge roller is a leading edge, and a recording area after the trailing edge of the recording medium is separated from the conveying roller is a trailing edge.

Here, the transport operation in a state where the recording medium is supported by the transport roller 1 and not supported by the discharge roller 12 is referred to as a first transport operation. Further, the transport operation in a state supported by both the transport roller 1 and the discharge roller 12 is referred to as a second transport operation. Furthermore, a transport operation in a state where the transport roller 1 is not supported but is supported by the discharge roller 12 is referred to as a third transport operation. When the transport operation is defined in this manner more strictly, the recording area can be divided into the following five areas. That is,
An area A in which an image is completed by only the first transport operation between recording scans;
A region B in which an image is completed by intervening the first conveyance operation and the second conveyance operation between recording scans;
A region C in which an image is completed by only interposition of the second conveying operation between recording scans;
An area D in which an image is completed by the intervention of the second conveyance operation and the third conveyance operation between recording scans, and an area E in which an image is completed by the intervention of only the third conveyance operation between recording scans,
It is. However, in the embodiment described below, for the above five regions, the region A and the region B are determined as the front end portion, the region C as the central portion, and the region D and the region E as the rear end portion. For the central portion, the first mask in the form of a gradation mask prepared for this is applied, while for the leading end portion and the trailing end portion, the second mask is extracted from the first mask. Shall apply.

  In the present embodiment, among the recording element groups (nozzle groups) arranged in the sub-scanning direction (recording medium conveyance direction), the nozzles included in a partial area located on the more downstream side (discharge roller side) Recording is performed on the front end and rear end. Therefore, the area treated as the rear end is slightly wider than the area treated as the front end.

  The recording apparatus of this embodiment forms an image with, for example, 10 colors of ink. The ten colors are, for example, cyan (C), light cyan (Lc), magenta (M), light magenta (Lm), yellow (Y), first black (K1), second black (K2), red (R), Green (G) and gray (Gray). Here, the first black K1 ink and the second black K2 ink are respectively a photo black ink that realizes high glossy recording on glossy paper and a matte black ink that is suitable for matte paper without gloss. be able to.

  FIG. 3 schematically shows a state in which the recording head 4 employed in the present embodiment is viewed from the nozzle forming surface side. The recording head 4 of this example has two recording element substrates H3700 and a recording element substrate H3701 in which nozzle rows for each of the ten colors are formed. H2700 to H3600 are nozzle rows corresponding to 10 different colors of ink, respectively.

  One recording element substrate H3700 is provided with nozzle rows H3200, H3300, H3400, H3500, and H3600 that are supplied with gray, light cyan, first black, second black, and light magenta inks and perform ejection operations. . On the other recording element substrate H3701, nozzle rows H2700, H2800, H2900, H3000, and H3100 are formed that perform discharge operations by being supplied with cyan, red, green, magenta, and yellow inks. Each nozzle row is composed of, for example, 1280 nozzles arranged at an interval of 1200 dpi (dot / inch; reference value) in the conveyance direction of the recording medium.

  When recording in the central portion of the recording medium shown in FIG. 2 (first recording in the present embodiment), the entire range W of each nozzle row, that is, 1380 nozzles is used as the relatively wide first range. Is possible. On the other hand, in front-and-rear end recording (second recording in the present embodiment), the used nozzle range of each row is reduced, and as a relatively narrow second range, for example, downstream in the recording medium conveyance direction (discharge roller side) It is possible to set so as to use a region R including 256 nozzles positioned at the same position. In other words, image degradation is prevented by reducing the recording width in one scan.

  FIG. 4 shows a configuration example of the main part of the control system of the ink jet recording apparatus according to the present embodiment. Here, reference numeral 100 denotes a control unit that controls each drive unit of the ink jet recording apparatus according to the present embodiment. The control unit 100 includes a CPU 101, a ROM 102, an EEPROM 103, and a RAM 104. The CPU 101 performs various calculations and determinations for processing related to the recording operation and the like, including processing procedures to be described later, and performs processing for print data and the like. The ROM 102 stores a program corresponding to a processing procedure executed by the CPU 101, other fixed data, and the like. In particular, the ROM 102 of the present embodiment stores a mask (hereinafter referred to as a first mask) that is applied to recording in the central portion of the recording medium. The EEPROM 103 is a non-volatile memory and is used to hold predetermined information even when the recording apparatus is turned off. The RAM 104 temporarily stores print data supplied from the outside and print data expanded in accordance with the apparatus configuration, and also functions as a work area for arithmetic processing by the CPU 101.

  The interface (I / F) 105 has a function of connecting to an external host device 1000 and performs bidirectional communication with the host device 1000 based on a predetermined protocol. The host device 1000 has a known form such as a computer, and serves as a print data supply source for causing the recording apparatus of this embodiment to perform printing, and a printer driver which is a program for causing the printing operation to be performed. Installed. That is, the printer driver sends print data, print setting information such as the type information of the recording medium on which the print data is printed, and a control command for controlling the operation of the recording apparatus.

  The linear encoder 106 detects the position of the recording head 4 in the main scanning direction. The sheet sensor 107 is provided at an appropriate position on the recording medium conveyance path. By detecting the leading and trailing edges of the recording medium using the sheet sensor 107, it is possible to know the conveyance (sub-scanning) position of the recording medium. Motor drivers 108 and 112 and a head drive circuit 109 are connected to the control unit 100. Under the control of the control unit 100, the motor driver 108 drives the transport motor 110 that is a recording medium transport drive source. The driving force of the conveyance motor 110 is transmitted to the conveyance roller 1 and the discharge roller 2 through a transmission mechanism such as a gear. The motor driver 112 drives a carriage motor 114 that is a driving source for moving the carriage 7. The driving force of the carriage motor 114 is transmitted to the carriage 7 via a transmission mechanism such as a timing belt. The head drive circuit 109 drives the recording head 4 under the control of the control unit 100 to perform an ejection operation.

(2) Generation of second mask In this embodiment, a mask in the form of a gradation mask is used in which the print allowance is relatively high at the center of all 1280 nozzles, and the print allowance gradually decreases toward the end. One mask is used. Then, from the first mask prepared corresponding to the nozzle use range W for recording in the central portion of the recording medium in this way, corresponding to the range R including 256 nozzles used for recording of the front and rear end portions. Data is extracted to generate a second mask. Therefore, when a second mask that does not appropriately extract data from the first mask is applied to the recording at the front and rear end portions, the mask pattern joints corresponding to the nozzle groups divided in the nozzle usage range R are used. As a result, a step having a large recording allowance is generated. It will be described that the image quality deteriorates due to this.

  FIG. 6 shows a first mask applied to recording in the central portion of the recording medium and the generation of the second mask from the first mask in the case of performing four-pass multi-pass recording using the recording head. An example of In the central recording, all 1280 nozzles in the range W are divided into 320 first to fourth nozzle groups. For each divided area, as shown in the left part of FIG. One mask is applied. On the other hand, in the recording at the rear end, 256 nozzles in the range R are divided into 64 first to fourth nozzle groups, and data extraction is performed from the first mask, as shown in the right part of the figure. A second mask is generated.

  At this time, data corresponding to 64 nozzles continuous from the nozzles positioned at the upstream end in the medium conveyance direction is extracted from each mask pattern corresponding to the first to fourth nozzle groups of the first mask, A mask pattern corresponding to the first to fourth nozzle groups of two masks is used. In the case where 256 multi-pass (4-pass) recording in the range R is performed by applying the second mask generated in this way, the total recording allowance is 100%.

  However, since the first mask has a high recording allowance at the center and the recording allowance gradually decreases toward the end, the generated second mask is recorded at the joint of the mask pattern. A step with a large allowable rate is generated. Accordingly, a nozzle group having a high recording allowance, that is, ejecting a large amount of ink, and a nozzle group having a low recording allowance, that is, a nozzle having low ink ejection are adjacent to each other. Here, in a recording head that discharges a large number of minute ink droplets at a high frequency, a position adjacent to a nozzle group with a small amount of ejection among nozzle groups with a large amount of ejection (that is, an end of a nozzle group with a large amount of ejection) ) Is deflected to the inside of the arrangement range. In this case, since the dots formed by the nozzles whose ejection direction has been deflected land on the inner positions that deviate from the normal positions, the pitch of the recording width of the recording head is confirmed. Accordingly, the dots to be formed by the nozzles located at the end of the nozzle group where there are many ejections are formed at positions inside the nozzle array that deviate from the normal positions. Edge streaks will occur. In other words, the effect of combining the reduction of the nozzle use range and the multi-pass printing to prevent image detriment is diminished.

  In addition, when a nozzle group with many ejections and a nozzle group with few ejections are adjacent to each other, the following problems due to the fact that a portion where a large amount of ink adheres to a portion where a small amount of ink adheres on the recording medium Also occurs. That is, it has been confirmed that the ink flows from a portion where a large amount of ink is adhered to a portion where a small amount of ink is adhered, particularly on a recording medium where the adhered ink is difficult to dry. The image quality may be deteriorated due to blurring or the like.

  Therefore, in the present embodiment, a configuration is adopted in which the second mask is appropriately generated so that the above-described problem does not occur even at the front and rear end portions where the nozzle use range is greatly reduced compared to the central portion of the recording medium. To do.

  FIG. 6 is an explanatory diagram of a generation mode of the second mask in the present embodiment. Here, the 1280 nozzles are the 0th to 1279th nozzles in order from the nozzle located on the most upstream side in the recording medium conveyance direction. In this case, each nozzle group (divided region) obtained by dividing the number of all nozzles (1280) by the number of passes (4) includes 320 nozzles continuous in the recording medium conveyance direction. If 16 nozzles are defined as one set, 20 sets are arranged for each divided nozzle group.

  Here, the number of nozzles included in each divided nozzle group used for recording in the central portion of the recording medium is m (m = 320 in the example of FIG. 6), and included in each divided nozzle group used for recording in the leading and trailing ends. Let n be the number of nozzles (n = 64 in the example of FIG. 6), and k be the integer part of the value obtained by dividing m by n. As described above, at the front and rear end portions of the recording medium, the used nozzle range is greatly reduced compared to the central portion of the recording medium (the number of used nozzles is greatly reduced), so m> n and k is 1 or more. (K = 5 in the example of FIG. 6).

  In this embodiment, each divided nozzle group (divided area) used for recording in the central portion of the recording medium is associated with each divided nozzle group (divided area) used for recording in the front and rear end portions, and the former is supported. The data of the latter recording allowance is extracted dispersedly from the portion of the first mask. That is, data is extracted as follows from the memory (ROM 104) which is a storage means that fixedly stores the mask data MD1 that defines the recording allowance ratio of each nozzle corresponding to the first mask, and the front and rear end portions A second mask applied during recording is generated. That is, assuming that the number of nozzles per set is L (L = 16 in the example of FIG. 8), mask data corresponding to L nozzles continuous from 0, 80, 160, 320,. To extract. The data extracted in this way is temporarily stored in the RAM 104 as the storage means, thereby generating a second mask MD2 as shown in the right part of FIG.

  As is apparent from FIG. 8, the second mask generated by this method is different from the second mask of FIG. The step of the recording allowance at the joint between the groups is small. Therefore, by applying the second mask, it is possible to suppress the deterioration of the image quality at the time of recording at the front and rear end portions of the recording medium, and to output an image having the same quality as the central portion of the recording medium. .

  Further, in the present embodiment, the second mask is not prepared in the ROM 102 in a fixed manner, but is generated from the first mask as needed and developed into the RAM 104 for use. Therefore, the memory capacity for preparing the mask data in advance is small. In particular, in the configuration in which the number of passes at the time of multi-pass printing can be changed according to the type of the recording medium used for recording and the mode for specifying the recording quality desired by the user, and a plurality of masks are prepared. Advantageously, both the first and second masks need not be provided.

  The second mask may be generated in advance and expanded in a RAM or the like, or may be applied while extracting data from the first mask when recording the front and rear ends. In this case, for example, the read start position S (S = 0, 80, 160, 320,..., 1200) of the first mask data from the ROM 102 is set prior to recording. Good. According to this, an area for developing the generated second mask becomes unnecessary, which can contribute to a reduction in the capacity of the RAM 104.

FIG. 7 shows an example of a recording processing procedure executed by the recording apparatus of this embodiment.
In this procedure, first, it is recognized whether or not it is a recording mode in which no margin is left at the front and rear end portions (step S1). For example, the host device 1000 can notify the mode information selected by the user on the UI screen displayed on the monitor of the host device 1000.

  Next, according to the recognized mode, the setting of the nozzle area used for recording and the carry amount are set (step S3). In other words, in the mode in which the marginless recording is performed, the nozzle use range R used for recording at the front end portion and the rear end portion of the recording medium is set, and a conveying operation corresponding to this is performed. Settings are made.

  Next, the recording data is developed and a mask applied at the time of recording is set (step S5). That is, the first mask is set to be applied to the central portion of the recording medium, and the above-described second mask generation or read position data generation from the first mask is performed on the front and rear end portions. The end is set so that the first mask is applied. Then, the recording operation to the front end portion, the central portion, and the rear end portion is sequentially executed (steps S7, S9, and S11).

(Other)
In the above-described embodiment, the number of passes during multi-pass printing is 4, the number of printing elements (nozzles) is 1280, all 1280 nozzles are used at the center of the printing medium, and 256 nozzles are used at the front and rear ends. An example was described. However, these numerical values are merely examples, and the present invention is applicable to multi-pass printing with a larger number of passes or a smaller number of passes, and even when a printing head with a larger number of nozzles or a smaller number of nozzles is used. It can be applied effectively. In addition, the present invention can be effectively applied as long as the nozzle usage range at the front and rear end portions of the recording medium is smaller than the nozzle usage range at the central portion of the recording medium.

  In the above-described embodiment, the recording method has been described for realizing marginless recording. However, the present invention is not limited to marginless recording. Further, the marginless recording may be realized at either the front end or the rear end of the recording medium. Further, ranges having different positions and sizes may be used between the front end portion and the rear end portion, or different second masks may be extracted or generated.

  In addition, in the above-described embodiment, a mode in which marginless recording is performed at the front and rear end portions has been described as an example of reducing the nozzle use range. However, the present invention is also applicable to, for example, an apparatus having a mode in which the conveyance error is reduced by reducing the nozzle use range even in the central portion, particularly when high quality recording is required. That is, there are at least two nozzle usage ranges of different sizes, and when performing multipass printing in the smaller nozzle usage range, data is extracted from the mask (first mask) prepared for the larger nozzle usage range. What is necessary is just to apply the second mask. The size, position, reduction ratio, and type of the use range can be determined as appropriate.

  In the above-described embodiment, the number of nozzles for one set of data extraction or reading is 16, but this number is not limited and can be changed within a range that can correspond to the specifications of the printing apparatus. Is possible. Further, in the above-described embodiment, the mask data is regularly extracted from the first mask. However, as long as the problem as shown in FIG. 6 does not occur, the mask data can be extracted at random and can be divided. The number of sets to be extracted from the nozzle group can also be determined as appropriate.

  Furthermore, the number of ink colors (color, density, etc.) to be used, the type of ink, the type of mask pattern to be applied, etc. are merely examples. For example, the form of mask (arrangement form of print permitting area) applicable in the present invention is not limited to the arrangement shown in the above-described embodiment. The present invention can be effectively applied to any mask that has a configuration in which the distribution of the print allowance ratio with respect to the nozzle position of the print head is not uniform along the direction of the nozzle arrangement. That is, as long as the print allowance ratio between the nozzles at the end and the nozzles other than the end has a predetermined correlation, the present invention can be applied to any arrangement of print pixels in the mask pattern. The effect can be demonstrated. For example, the arrangement may be such that a pattern such as the gradation mask described above is repeated periodically. Further, it may be an array having randomness as disclosed in Patent Document 5, or a dot arrangement having a predetermined dispersibility as described in Patent Document 6. The present invention is also effective when various mask patterns are applied.

  In addition, in the above embodiment, a recording method using an ink jet recording head that discharges ink as droplets has been described. However, the effect of the present invention is not limited to such a recording method. The present invention can be applied to any recording method as long as a recording head in which a plurality of recording elements are arranged is used without being limited to nozzles.

1 is a schematic perspective view illustrating an overall configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 5 is a diagram illustrating regions at a front end portion, a central portion, and a rear end portion when performing marginless recording on a recording medium. It is a front view which shows typically the state which looked at the recording head 4 employ | adopted by embodiment from the nozzle formation surface side. 2 is a block diagram illustrating a configuration example of a main part of a control system of the ink jet recording apparatus according to the embodiment. FIG. It is explanatory drawing for demonstrating the inconvenience when data extraction is not performed appropriately when producing | generating a 2nd mask from a 1st mask. It is explanatory drawing for demonstrating the aspect of the data extraction which concerns on embodiment. It is a flowchart which shows an example of the recording processing procedure which the recording device of embodiment performs. FIG. 3 is a schematic side view showing a recording head, a recording medium, and a transport mechanism that transports the recording medium in a state where a central portion of the recording medium is recorded. FIG. 6 is a schematic side view for explaining that image disturbance occurs in the vicinity of the rear end of the recording medium. FIG. 6 is a schematic side view for explaining that image disturbance occurs in the vicinity of the leading end of the recording medium. It is a schematic diagram for demonstrating the multipass recording method. It is explanatory drawing which shows an example of the mask pattern applied to a multipass printing method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conveyance roller 4 Recording head 12 Discharge roller 101 CPU
102 ROM
104 RAM

Claims (10)

A recording scan in which recording is performed while a recording head having an array of recording elements scans the recording medium in a direction different from the direction of the array, and conveyance of the recording medium in a direction crossing the direction of the recording scan A recording apparatus capable of recording an image by performing a plurality of recording scans according to a pixel arrangement complementary to the same image area,
Setting capable of setting a first recording using a recording element group included in the first range of the array of recording elements and a second recording using a recording element group included in a second range narrower than the first range. Means,
A first mask that is applied to define the pixel array when the first recording is performed, and the first mask having a nonuniform distribution of the recording allowance in the direction of the array is fixed to perform the definition. Storage means for storing automatically,
Extracting means for extracting the data of the recording allowance ratio from the stored first mask and serving as a second mask to be applied to define the pixel arrangement when executing the second recording;
And the extraction means performs extraction so that the recording allowance of the second mask changes monotonously along the direction of the array.   The first range and the second range are divided into a plurality of regions corresponding to the plurality of printing scans, and the extraction unit includes the plurality of divided regions of the first range and the second range of the second range. The extraction is performed in association with a plurality of divided areas, and data of the recording allowance ratio is extracted by being distributed from the portion of the first mask corresponding to the divided areas in the first range. Item 2. The recording device according to Item 1.   The setting means performs setting so that the first recording is performed on a central portion of the recording medium and the second recording is performed on at least one of a front end portion and a rear end portion of the recording medium. The recording apparatus according to claim 1, wherein the recording apparatus is a recording apparatus. A first conveying unit that conveys the recording medium upstream from the recording head in the conveying direction; and a second conveying unit that conveys the recording medium downstream from the recording head in the conveying direction. The setting unit determines that the recording medium is recording on the tip when the recording medium is supported only by the first conveying unit, and the recording medium is the first and second conveying units. When the recording medium is supported by both means, it is determined that the recording is performed on the central portion, and when the recording medium is supported only by the second conveying means, it is determined that the recording is performed on the rear end portion. The recording apparatus according to claim 3.   The recording apparatus according to claim 1, wherein the first range and the second range are a whole range and a partial range of the arrangement of the recording elements, respectively.   The first mask is configured such that, among the recording elements included in the first range, a recording allowance of a recording element located at an end is lower than a recording allowance of a recording element located at a central portion. The recording apparatus according to claim 1, wherein the recording apparatus is a recording apparatus.   The recording apparatus according to claim 1, wherein the recording head is an ink jet recording head having a nozzle for discharging ink as the recording element.   8. The recording apparatus according to claim 1, further comprising storage means for temporarily storing the second mask generated by the extraction.   8. The recording apparatus according to claim 1, further comprising storage means for temporarily storing a position where the extraction is performed from the storage means. A recording scan in which recording is performed while a recording head having an array of recording elements scans the recording medium in a direction different from the direction of the array, and conveyance of the recording medium in a direction crossing the direction of the recording scan And a recording method capable of performing recording in a plurality of recording scans according to a pixel array having a complementary relationship with respect to the same image area,
Setting capable of setting a first recording using a recording element group included in the first range of the array of recording elements and a second recording using a recording element group included in a second range narrower than the first range. Process,
A first mask that is applied to define the pixel array when the first recording is performed, and the first mask having a nonuniform distribution of the recording allowance in the direction of the array is fixed to perform the definition. Reading the stored first mask from the storage means for storing the first mask and applying it to the first recording;
Extracting the data of the recording allowance ratio from the first mask and extracting it as a second mask applied to define the pixel arrangement when performing the second recording;
And the extraction step performs the extraction so that the recording allowance of the second mask changes monotonously along the direction of the array.

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