JP4994819B2 - Recording apparatus and data generation method - Google Patents

Description

  The present invention relates to a recording apparatus and a recording method that perform recording using a recording head in which a plurality of recording elements are arranged in a line, and relates to a recording apparatus and a recording method that are suitable when using a so-called full-line type inkjet recording head. Is.

  A recording device used as an output device such as a printer, a copying machine, a composite electronic device including a computer, a word processor, or a workstation, or a workstation, has an image (including characters and symbols) on a recording medium such as paper based on the recorded information. Is configured to record. Such a recording apparatus is classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method.

  In a so-called serial type recording apparatus that performs recording while scanning in the main scanning direction that intersects the conveyance direction (sub-scanning direction) of the recording medium, an image is recorded using a recording head as recording means that moves along the recording medium. Record. That is, every time the recording operation for one main scan is completed by the recording head, the recording medium is conveyed by a predetermined amount, thereby performing recording on the entire recording medium.

  On the other hand, in a so-called full-line type recording apparatus in which the recording head has a recording width corresponding to the width of the recording medium and only moves in the conveying direction of the recording medium, the recording medium is set at a predetermined position and the recording medium is conveyed. However, the recording operation for one line is continuously performed. By doing this, recording is performed on the entire recording medium.

  Among the recording apparatuses of each type, an ink jet recording apparatus (ink jet recording apparatus) uses an ink jet recording head as recording means, and performs recording by discharging ink from a discharge port of the recording head toward a recording medium. It is. Such an ink jet recording apparatus is easy to downsize the recording head, can form high-definition images at high speed, can record on so-called plain paper without requiring special processing, and has low running cost. It has the advantage of being. Further, since it is a non-impact method, there are also advantages such as low noise and the ease of adopting a configuration for forming a color image using multicolor ink. Further, in this type of recording apparatus, a full recording head using a recording head (so-called full line type recording head) in which a large number of ink jet recording elements are arranged in a direction intersecting (generally orthogonal) with the conveyance direction of the recording medium. There is a line-type recording device. The full-line type recording apparatus is capable of further increasing the speed of image formation, and has attracted attention as a recording apparatus for on-demand recording whose needs are increasing. (For example, refer to Patent Document 1.) The ink jet recording element is positioned over the entire width of the recording area of the recording medium, and has a configuration capable of ejecting ink from the ejection port.

  By the way, in such a full-line type recording apparatus for on-demand recording, for example, for mono-color recording such as text, a resolution of 600 × 600 dpi (dot / inch) or more is applied to an A3-sized recording medium every minute. Recording on 30 pages or more is required.

For recording a full color image such as a photograph, it is required to record a high resolution of 1200 × 1200 dpi or more on an A3 size recording medium at 30 pages or more per minute.
Japanese Patent Laid-Open No. 2002-292859

  However, in the recording head used in the above-described full-line type recording apparatus, all of the ink jet recording elements located over the entire width of the recording area of the recording medium, in particular, the discharge ports forming part of the ink jet recording elements are processed satisfactorily. It was difficult. For example, in a full-line type recording apparatus, about 14,000 discharge ports (recording width of about 280 mm) are formed in a full-line type recording head in order to perform recording at a resolution of 1200 dpi on A3 size paper. It is necessary to do. Further, in a full line type recording head, it is difficult in terms of the manufacturing process to satisfactorily process all the ink jet recording elements corresponding to such a large number of ejection openings. Further, even if such a recording head can be manufactured, the yield rate is low and the manufacturing cost becomes large.

  Therefore, a so-called connecting head has been proposed as a full-line type recording head used in a full-line type ink jet recording apparatus. The connecting head is a recording head in which a plurality of head chips each having a recording element array in which a plurality of recording elements are arrayed are arrayed in the recording element array direction. In other words, it is possible to increase the length by arranging these chips with high precision so that a plurality of relatively inexpensive short-chip-type recording heads used in the serial type are connected in the arrangement direction of the discharge ports. This is a long recording head to be realized.

  However, as a result of intensive investigations by the present inventors, such a connecting head has a configuration in which it is likely that image quality deterioration, that is, a so-called connecting streak is likely to occur in a recording portion by a recording element located at a connecting portion between a plurality of head chips. It became clear that there was a problem. The term “joint portion” as used herein refers to a portion in which the end portions of the recording element arrays of the adjacent head chips are adjacent to each other. In a connection head having such a configuration, it is necessary to connect a plurality of head chips with high accuracy, and due to variations in the spacing between the plurality of head chips and a relative position shift between the head chips, Streaks occur in the image corresponding to the connecting portion.

  As disclosed in Patent Document 1, several improvement measures have been proposed for the connecting stripe generated by such a connecting head. For example, there is a method of reducing the displacement of the discharge port pitch by using an array method or an array device for performing head chip array of connecting portions with high accuracy. As another countermeasure, the head chip connecting portions are not arranged so that the discharge ports at the respective head chip ends are adjacent to each other in the arrangement direction of the discharge ports, and a predetermined number of discharge ports at the respective head chip ends are arranged. There is a method in which the recording media are arranged so as to overlap in the conveyance direction. In this case, at the time of recording, ink is ejected from both ejection ports that overlap each other, thereby making the connecting stripe inconspicuous.

  However, none of these measures can be said to be sufficient with respect to the connecting stripes generated when recording a photographic tone.

  As described above, by arranging the plurality of head chips so that the recording areas of the adjacent head chips partially overlap, the connecting stripe between the head chips can be reduced. However, in such a recording head configuration, it is necessary to arrange adjacent head chips at different positions in the paper movement direction. Image degradation may occur due to the spacing between the head chips in the paper movement direction.

  For example, a recording medium conveyance variation (so-called conveyance meandering) of the recording apparatus or a relative positional relationship between a full-line type recording head and the recording medium occurs. Due to these effects, the discharge port pitch formed by the discharge port of the adjacent recording element in the connection part is not the same as the other discharge port pitch, and corresponds to the connection part of the chip on the recorded image. May occur. Due to the structure of the connection head, the distance between the discharge port arrays used for recording at the connection portion in the discharge port array direction is often larger than the discharge port array used for recording at the non-connection portion. For this reason, it is considered as one factor that the connecting portion is easily influenced by the above-described meandering and tilting. Hereinafter, problems caused by meandering during conveyance and the relative inclination between the recording head and the paper will be described.

  For example, in Patent Document 1, the head chips are arranged in a staggered manner. In this case, the recording head and the recording medium are inclined in a direction inclined from a designed angle (generally, a direction perpendicular to the recording element array). There is a case where recording is performed by conveying. As a result, the positional relationship in the recording element array direction shifts for each recording element array, and the head chip ends alternately approach the recording element array direction and become widened. More specifically, the recording element arrays having the same positional relationship in the direction perpendicular to the recording element array have a relationship of being shifted in the recording element array direction by the same amount and recorded on the recording medium. For this reason, even if the head chip mounting accuracy is sufficiently high at the head chip end, if the recording head and the recording medium are tilted away from the designed angles, image quality deterioration occurs at the head chip end.

  FIG. 1 is an explanatory diagram of a case where recording is performed while using the recording heads IJH in which the head chips 5 are arranged in a staggered manner while the recording head IJH and the recording medium are moved relative to each other in a direction inclined from the designed angle. is there. The head chip 5 has recording elements (recording element 6-a that performs recording, recording element 6-b that does not perform recording). Here, the conveyance direction as designed for the recording medium is A, and the conveyance direction that is shifted and inclined is B. When the transport direction is A, the recording on the recording medium by the recording element of the head chip at the joint (joint) is equally spaced from the recording on the recording medium by the recording element that is not the joint. However, when the transport direction is B, the recording on the recording medium by the recording element of the joint head chip is closer to the portion corresponding to the joint of X, and the portion corresponding to the joint of Y is widened. End up.

  Here, when the same color is recorded, if the positional relationship between the head chips is a fraction of the recording dot diameter and is shifted on the recording medium, a connecting stripe can be seen in the recording area by the joint between the head chips. The inventors confirmed that there is. Specifically, as shown in FIG. 1, when recording was performed using a recording head in which three or more head chips were connected, white streaks (connecting streaks) occurred at the end of the chip in the recording element array direction.

In view of the problems as described above, an object of the present invention is to achieve high image quality of recorded images without streaking while maintaining high-speed image formation, which is an advantage of a full-line type inkjet recording apparatus. It is to provide a recording apparatus and a data generation method that can be used.

  As a result of intensive studies, the present inventors have found that there is a difference in the connecting stripe between the recording area by the joint between the head chips corresponding to the approaching eye and the recording area by the joint between the head chips corresponding to the spreading eye. I found it. This means that the connecting stripes are less noticeable in the recording area formed by the joint between the head chips corresponding to the approaching eye. Accordingly, the inventors of the present invention have focused on the fact that the recording duty at the joint between the head chips corresponding to the approaching eyes has a high recording duty, and have further studied earnestly from this point of view to reach the present invention.

  Specifically, in order to achieve the above object, the present invention has the following configuration.

The first and second recording element arrays in which a plurality of recording elements are arrayed overlap each other in the transport direction of the recording medium intersecting with the array direction, and the first recording element array An image is recorded by ejecting ink droplets onto the recording medium using a recording head configured such that the region other than the joint portion and the region other than the joint portion of the second recording element array do not overlap each other. A recording device,
Input means for inputting recorded data;
Conveying means for conveying the recording medium in the conveying direction ;
Based on the recording data corresponding to the connecting portion of the recording data input by the input means, the first recording data corresponding to the connecting portion of the first recording element array, and the second recording Data generating means for generating second recording data corresponding to the connecting portion of the element array ;
Recording control means for controlling recording of an image on the recording medium conveyed by the conveying means using the recording head based on the first and second recording data generated by the data generating means ; Have
The data generation unit is configured to record recording data corresponding to the connecting portion of the recording data input by the input unit, and the first and second recording element arrays in the recording direction in the transport direction. Two recordings so that the amount of ink applied in the transport direction by the first and second recording element arrays at the joint portion decreases toward the end of each recording element array. Distribute to data,
Relative to the two recording data in a direction corresponding to a predetermined number of recording elements, in the direction from the center of each of the first recording element array and the second recording element array to the end portion constituting the connecting portion. The first recording data and the second recording data are generated by displacing each other.

  Therefore, according to the present invention, a high-quality image can be obtained by using a full-line type recording head in which a plurality of recording elements are arranged in a line and a plurality of the recording element arrays are arranged in the column direction of the recording elements. Can be recorded.

  In this specification, “recording” not only forms significant information such as characters and graphics, but also forms images, patterns, patterns, etc. on a wide variety of recording media, regardless of significance, or It also represents the case where the medium is processed. It does not matter whether it has been made obvious so that humans can perceive it visually.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Further, “ink” should be interpreted widely as the definition of “recording (printing)” above, and when applied to a recording medium, it forms an image, a pattern, a pattern, etc. or processes the recording medium. Or a liquid that can be subjected to ink processing. Further, as an example that can be used for ink processing, there is coagulation or insolubilization of the colorant in the ink applied to the recording medium.

  In the present invention, it is a requirement that “when the recording medium is conveyed for a significant length, recording is performed by the recording elements of both the first and second head chips”. Here, “significant length” means a statistically meaningful length. Specifically, for example, when an image is formed at 1200 dpi × 1200 dpi, when a 1-inch recording medium is conveyed, each recording element has a recording opportunity of 1200 times. If there are 1,200 recording opportunities, the ratio of the number of times of recording to the number of times of not recording is considered statistically significant. For this reason, for example, when an image is formed at 1200 dpi × 1200 dpi, 1 inch can be referred to as “significant length” in the present invention. Further, the “recording duty” in the present invention represents the ratio of how many times recording is performed out of the number of recording opportunities of the recording element when the recording medium is conveyed by a significant length. For example, out of 1,200 recording opportunities, 100% duty is recorded when recording 1200 times, 50% duty when recording 600 times, and 0% duty when not recording once.

  Embodiments of the present invention will be described below with reference to the drawings.

  2 and 3 are conceptual diagrams of a connecting portion of a conventional recording head, a recording duty of the connecting portion in the recording element array direction, and a recording image of a recording area by the recording element of the connecting portion. is there.

  FIG. 2 shows the head chip joint portion when the recording medium is transported as designed, the recording duty of the head chip joint portion with respect to the recording element array direction, and the recording image of the recording area by the recording element of the joint portion. It is a conceptual diagram.

  The number of recording elements in the area where the recording areas overlap in the direction of the recording element array between the head chips is shown, but for the sake of simplicity, the figure of the head chip is shown with the number of recording elements reduced from the figure showing the recorded image. is doing. Actually, it is assumed that the number of recording elements corresponding to the recorded image is provided. Further, the recording duty in the recording element array direction of the joint portion takes the recording duty on the vertical axis, and in the overlapping portion, the total recording of the overlapping portion of the head chip 5-a and the overlapping portion of the head chip 5-b is performed. The duty is indicated by a dotted line.

  The subject of the present invention is both a serial type and a one-pass full-line type recording apparatus. However, a one-pass full-line type recording apparatus that has a high need to lengthen the head even when a head chip is connected is used. This is mainly described because it is considered the main target. The problem that the recording head and the recording medium move relative to each other at the joint between the head chips in the serial recording apparatus is the same as that of the full line system in which only one pass is seen in the same path. For this reason, it can be solved by the present invention in the same manner as the full line system. Therefore, it is omitted from the description.

  In addition, here, a long chip having a plurality of recording elements arranged in a zigzag manner as shown in FIG. 1 with a plurality of recording elements overlapped in the recording element array direction in the direction of the recording element array is provided. The head is used. Then, using a full-line recording apparatus that records in one recording pass of the recording medium width by applying the recording color material to the recording medium while transporting the recording medium in a direction crossing the recording element array direction. Yes. For the sake of explanation, the area recorded by the head chip 5-b is shown in gray. However, the head chip 5-a and the head chip 5-b are actually recorded with recording materials of the same color and density. ing.

  In the area where the recording areas overlap in the recording element array direction, the area where one head chip does not record is complementarily recorded by the other head chip. Specifically, for example, when recording a solid portion where the recording duty is 100%, in the head chip 5-a, the recording duty is increased from 100% to 0% toward the end of the overlapping portion. A recording area determined by generating values and binarizing by dithering or error diffusion is recorded. In the head chip 5-b, the remaining area obtained by inverting it is recorded in a mutually complementary manner. As a result, the entire recording area is distributed to one of the head chips. If there is a plurality of recording element arrays in one head chip, the allocation of the recording area is distributed among the head chips and then distributed among the recording element arrays in the head chip. Thus, if the recording medium is conveyed at the designed angle, there is no positional deviation of the recording dots, there is no gap in the recordable area, and recording according to the recorded image data is performed as shown in the conceptual diagram of the recorded image in FIG. Is possible.

  FIG. 3 shows a head chip connecting portion when the recording medium is conveyed in a direction inclined from the designed angle, a recording duty of the connecting portion of the head chip with respect to the recording element array direction, and recording of the connecting portion. It is a conceptual diagram of an image.

  However, if the recording head and the recording medium are transported at an angle as designed in this way, as shown in FIG. 1, the head approaches or separates between the head chips in the recording element array direction. End up. Then, in the area where the recording area overlaps in the recording element array direction, the recording dot position shift occurs, and there is a part where the overlap between the recording dots increases and a part where there is a gap between the recording dots. To do. As a result, the recording density of the portion where the recording dots overlap does not double, so that the recording density of the region where the recording region overlaps in the recording element array direction decreases. At this time, the amount of deviation between the head chips changes in proportion to the amount by which the angle at which the recording medium is conveyed tilts from the designed angle. As the amount of deviation increases, the area where the recording areas overlap in the direction of the recording element array between the head chips tends to become thinner. The conceptual diagram of the recorded image in FIG. 3 shows this.

  FIG. 4 is a diagram illustrating the connection of streak lines at the recording dot shift amount for each recording duty when recording at the connecting portion of the head chip is performed by changing the recording duty and further shifting the recording dot position in the recording element array direction. It is a result table | surface which evaluated visually the presence or absence of generation | occurrence | production. Here, the shift toward the proximity side corresponds to the recording dot shift when approaching the recording element array direction, and the shift toward the separation side corresponds to the recording dot when separating toward the recording element array direction. It corresponds to a gap. Further, the deviation of the recording dot position from the position of 0 to the proximity side and the separation side is shifted to 20 μm every 5 μm, and the recording duty is from low duty (2.3%) to high duty (100%). Therefore, it is determined whether or not there is a connecting stripe under that condition. Further, the positional deviation of the recording dots is a value in which the deviation toward the proximity side is negative and the deviation toward the separation side is positive.

  Here, as in FIG. 2, for example, when the recording duty is 100%, one head chip has a multi-value so that the recording duty is linearly 100% to 0% toward the end of the overlapping portion. A recording area that was generated in step 2 and binarized with dither was recorded. In the other head chip, the remaining area obtained by inverting it was recorded in a complementary manner. Similarly, when the recording duty is 2.3%, one head chip is generated in multiple values so that the recording duty is linearly from 2.3% to 0% toward the end of the overlapping portion. A recording area binarized by dither was recorded. In the other head chip, the remaining area obtained by inverting it was recorded in a complementary manner.

  Here, “◯” in the table indicates that a connecting stripe has not occurred, and “X” indicates that a connecting stripe has occurred. Currently, from the viewpoint of the conveyance accuracy of the recording medium, a recording dot shift of about 30 μm (± 15 μm) at the maximum can occur. In consideration of this, it can be seen from this table that when a recording dot shift of 10 μm to 15 μm occurs on the separated side (“NG area” in FIG. 4), a connecting stripe occurs.

  Further, when the recording data is supplied to the recording element linearly, the recording duty of the recording element on the side where duplication starts is high, and the recording duty of the recording element on the side where duplication ends is low, As shown in FIG. 4, it is difficult to reduce the thickness on the close side where the eye approaches. Here, when the head chips are arranged in a staggered manner as shown in FIG. 1, when the recording medium is conveyed at an angle as designed, recording is performed between odd-numbered chips and even-numbered chips and between even-numbered chips and odd-numbered chips. In the direction of the element row, the eyes approach and leave alternately. Therefore, one in every other two between the head chips is conspicuous.

  Therefore, in the present invention, the recording data is recorded on a pixel-by-pixel basis so that the recording medium is conveyed at an angle from the designed angle and is recorded with a normal dot arrangement when the head chips are spread. You can approach the direction and shift to the eye direction. In this way, when recording is performed with approaching, and the recording duty of the overlapping portion where the end portions of the recording element arrays overlap each other is increased, the connecting stripes are less noticeable as derived from the result of FIG. In addition, it was considered that the recording density increased due to approaching eyes and a larger number of recording dots, but this was offset by the effect of thinning by shifting the recording position, and as a result, the recording density hardly changed. I also found out that.

  In the present invention, in the overlapping portion where the end portions of the recording element arrays overlap each other, only the image area in which the multi-value halftone is binarized is recorded with one head chip, and the other head chip is connected to perform image processing. It is preferable to record the image area. This is because only the image area obtained by binarizing the multi-value halftone is recorded in one head chip, and the remaining image area is mutually complemented by the other head chip for the entire image area subjected to the connected image processing. Means to record automatically.

  In addition, it is preferable that the recording duty by the recording element in the overlapping portion changes linearly with respect to the column direction of the recording element array, and the recording duty of the recording element on the overlapping end side is minimized. This is to prevent the recording area from being overlapped from becoming darker or lighter.

  In addition, as a method for binarizing a multi-value halftone in the present invention, error diffusion and dithering can be mentioned.

Next, a recording apparatus, a recording head, and a control configuration that are preferably used in the present invention will be described.
<Basic Configuration of Recording Apparatus (FIG. 5), (FIG. 6)>
FIG. 5 is an external perspective view showing the configuration of the main part of an ink jet printer IJRA that can be preferably implemented in the present invention. As shown in FIG. 5, the ink jet printer of this embodiment includes a recording head (full line recording head) IJH that ejects ink jets over the entire width of a recording medium such as a continuous sheet recording medium P, for example. Are arranged in the transport direction. Ink is ejected toward the recording medium P from the ejection ports of the head chip IT of these recording heads IJH at a predetermined timing.

  In this embodiment, the recording sheet P, which is a continuous sheet that can be folded, is driven in the VS direction shown in FIG. 5 by driving the transport motor under the control of the control circuit described below, and image recording is performed on the recording sheet. Is made. In FIG. 5, reference numeral 5018 denotes a conveying roller. A discharge side 5019 holds the recording medium P that is a continuous sheet together with the conveyance roller 5018 at the recording position, and conveys the recording medium P in the direction of the arrow VS in conjunction with the conveyance roller 5018 driven by a drive motor (not shown). The roller.

  FIG. 5 shows a configuration in which one full line recording head IJH is provided to eject black (K) ink as a configuration for performing monochrome recording. However, when performing color recording, as will be described later with reference to FIG. 6, at least four full-line recording heads are provided along the conveyance direction of the recording medium, corresponding to the ink used for color recording. Examples of ink used for color recording include yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (K) ink.

  For example, two full-line recording heads that eject ink of the same color may be provided for high-quality recording and high-speed recording.

  Furthermore, the recording medium used in the recording apparatus may be a continuous sheet as shown in the figure or a cut sheet.

  FIG. 6 is a front view for explaining a conceptual configuration centering on the recording head portion of another ink jet recording apparatus according to an embodiment of the present invention. A head unit is constituted by a plurality of long ink jet recording heads 1, 2, 3, and 4, and each of the ink jet recording heads 1, 2, 3, and 4 has a plurality of ink ejecting ports from corresponding ink ejection ports. Inkjet recording elements are arranged. The recording heads 1, 2, 3, and 4 are long recording heads for ejecting black (K), cyan (C), magenta (M), and yellow (Y) ink, respectively. An ink supply tube (not shown) is connected to the recording head, and a control signal and the like are sent via a flexible cable (not shown). A recording medium P such as plain paper, high-quality exclusive paper, OHP sheet, glossy paper, glossy film, postcard or the like is sandwiched between a conveyance roller and a discharge roller (not shown), and the direction of the arrow (main) Sent in the scanning direction). The ink jet recording element includes an ejection port and an energy generating element for ejecting ink provided corresponding to each ejection port. In the ink jet recording element of this example, a heating element (electric / thermal energy converter) that generates thermal energy used for ink ejection is provided in the interior (liquid path) communicating with the ink ejection port. In accordance with the reading timing of a linear encoder (not shown) that detects the transport position of the recording medium P, the heating element is driven based on the recording signal to eject ink droplets from the ink ejection port onto the recording medium P. Adhere. An image can be recorded by ink droplets landed on the recording medium P.

  The ink jet recording head seals the ink discharge port surface by a cap portion of a capping unit (not shown) when recording is not performed, thereby adhering ink due to evaporation of the ink solvent or adhering foreign matter such as dust. Clogging due to such as is prevented.

Further, the cap portion of the capping means is a cap portion for discharging ink that does not contribute to image recording from the ink discharge port (preliminary discharge) for eliminating discharge defects and clogging of the ink discharge port that is not frequently used. It can be used for discharging toward the water. In addition, a negative pressure generated by a pump (not shown) is introduced into the cap portion in the capped state, and ink that does not contribute to image recording is sucked and discharged from the ink discharge port of the recording head into the cap portion. It is also possible to recover the ink discharge port that caused the defect. Further, by disposing a blade (wiping member) (not shown) at a position adjacent to the cap portion, it is possible to clean (wipe) the ink discharge port forming surface of the ink jet recording head.
<Basic configuration of recording head (FIG. 7)>
FIG. 7 is an exploded perspective view illustrating a configuration example of a main part of the above-described ink jet recording head.

  The ink jet head IJH of this example mainly includes a heater board 23 that is a substrate on which a plurality of heaters (heating elements) 22 for heating ink is formed, and a top plate 24 that covers the heater board 23. It is configured as a prime. A plurality of discharge ports 25 are formed in the top plate 24, and a tunnel-like liquid path 26 communicating with each discharge port 25 is formed behind each discharge port 25. Each liquid path 26 is commonly connected to one ink liquid chamber at the rear thereof, and ink is supplied to the ink liquid chamber via an ink supply port, and the ink is supplied from the ink liquid chamber to each liquid path. 26. The discharge port 25 forms a discharge port capable of discharging ink.

  As shown in FIG. 7, the heater board 23 and the top plate 24 are assembled so that each heater 22 is positioned at a position corresponding to each liquid path 26. In FIG. 7, four discharge ports 25, heaters 22, and liquid paths 26 are representatively shown, and one heater 22 is arranged corresponding to each liquid path 26. In the inkjet head IJH assembled as shown in FIG. 7, when a predetermined driving pulse is supplied to the heater 22, the ink on the heater 22 boils to form bubbles, and the volume expansion of the bubbles Ink is ejected from the ejection port 25.

  The ink jet recording method to which the present invention can be applied is not limited to the bubble jet (registered trademark) method using a heating element (heater) as shown in FIGS. For example, in the case of a continuous type in which ink droplets are continuously ejected into particles, there are a charge control type and a divergence control type. Further, in the case of an on-demand type that ejects ink droplets as necessary, it can also be applied to a pressure control system that ejects ink droplets from an orifice by mechanical vibration of a piezoelectric vibration element. As described above, the present invention is applicable to a recording head including various ink jet recording elements.

  FIG. 8 shows a recording head constructed by arranging a plurality of head chips each having a recording element array in which recording elements preferably used in the present invention are arrayed so that the recording element arrays are parallel to each other. FIG. This is a recording head IJH in which a plurality of head chips 5 each having a recording element array composed of a plurality of recording elements 6 are arranged in a staggered manner, and has a recording element overlapping region D between the head chips 5.

In the present invention, in addition to the head chip having one recording element array on one head chip shown in FIG. 8, a head chip having a plurality of recording element arrays on one head chip can be preferably used. . FIG. 9 is a diagram showing an example of a head chip having a plurality of recording element arrays on one head chip that can be preferably used in the present invention. It is preferable to have a plurality of recording element arrays because the recording element array can have a higher resolution than a recording head having one head chip. FIG. 9A shows a head chip in which two recording element arrays are arranged so that the recording elements are arranged in a staggered manner. FIG. 9B shows a head chip in which four recording element arrays are arranged so that the recording elements are arranged in a staggered manner. FIG. 9C illustrates a head chip in which each recording element is aligned in a direction orthogonal to the recording element array direction.
<Control Configuration of Recording Apparatus (FIG. 10)>
FIG. 10 is a block diagram showing a configuration example of a control system in the ink jet recording apparatus as an embodiment of the present invention.

  In FIG. 10, 31 is an image data input unit, 32 is an operation unit, 33 is a CPU unit that performs various processes, and 34 is a non-volatile storage medium that stores various data. The print information storage memory of the storage medium 34 stores mainly information 34a relating to the type of recording medium, information 34b relating to ink used for printing, and information 34c relating to the environment such as temperature and humidity during recording. 34d shows various control program groups. Furthermore, 35 is a RAM, 36 is an image data processing unit, 37 is an image recording unit for outputting an image, and 38 is a bus unit for transferring various data.

  More specifically, the image data input unit 31 inputs multi-value image data from an image input device such as a scanner or a digital camera, or multi-value image data stored in a hard disk of a personal computer. The operation unit 32 includes various keys for setting various parameters and instructing start of recording. The CPU 33 controls the entire recording apparatus according to various programs in the storage medium. The storage medium 34 stores a program for operating the recording apparatus according to a control program and an error processing program. All operations in this example are operations according to this program. As the storage medium 34 for storing such a program, ROM, EPROM, EEPROM, FeRAM, FD, CD-ROM, HD, memory card, magneto-optical disk, or the like can be used. The RAM 35 is used as a work area for various programs in the storage medium 34, a temporary save area for error processing, and a work area for image processing. The RAM 35 can also copy various tables in the storage medium 34, change the contents of the tables, and proceed with image processing while referring to the changed tables.

  The image data processing unit 36 quantizes the input multi-value image data into N-value image data for each pixel, and creates an ejection pattern corresponding to the gradation value “K” indicated by each quantized pixel. To do. That is, after the input multi-value image data is subjected to N-value processing, an ejection pattern corresponding to the gradation value “K” is created. For example, when multi-value image data expressed in 8 bits (256 gradations) is input to the image data input unit 31, the image data processing unit 36 sets the gradation value of the output image data to 25 (= 24 + 1) values. Need to convert. In this example, the multi-value error diffusion method is used for the K-value processing of the input gradation image data. However, the present invention is not limited to this. Can be used. Further, by repeating the above-described K-value conversion processing for all the pixels based on the density information of the image, binary drive signals for ink ejection and non-ejection for each pixel corresponding to each ejection port 25 are obtained. Is formed.

  The image recording unit 37 ejects ink from the corresponding ejection port 25 based on the ejection pattern created by the image data processing unit 36 to form a dot image on the recording medium. The bus line 38 transmits address signals, data, control signals, and the like in the apparatus.

  Next, regarding a specific embodiment of the present invention used in the recording apparatus having the above-described configuration, the arrangement and driving of the discharge ports, which are characteristic portions of the invention, and the actual recording operation using the recording head are described. I will explain. In addition, the example here is an example and is not limited to this example.

First, the recording data can be created by a method used in a normal ink jet printer. In this embodiment, the input image is color-separated so as to correspond to the recording head for each ink color, and then the color-separated gray image is binarized by the error diffusion method, Recording data to be recorded by the recording head was prepared.
[Example 1]
FIG. 11 is a conceptual diagram of a recording head joint portion, a recording duty of the joint portion in the recording element array direction, and a recording image of a recording area by the recording element of the joint portion in Embodiment 1 of the present invention. is there.

  In the first embodiment, the recording duty in the recording element overlapping area in the joint portion of the head chip 5-a changes linearly with respect to the column direction of the recording element array. The recording duty of the recording element on the side where the overlap with the recording element of the head chip 5-b begins is high, and the recording duty of the recording element on the side where the overlap ends is low. Also, the recording elements in the region from α-b to β-b in the drawing of the recording element overlapping region of the connecting portion of the head chip 5-b are the same as the recording elements that are not the overlapping portion of the head chip 5-b. It is a duty. The recording elements in the region from β-b to γ-b in the drawing of the head chip 5-b are such that the recording element array is minimized at γ-b, which is the recording element on the side where the overlap ends. The recording duty is linearly changed with respect to the column direction. As is apparent from the diagram of the recording duty with respect to the recording element array direction of the connecting portion in FIG. 11, by doing this, the total recording duty by the recording elements in the overlapping portion is calculated from the recording duty by the recording elements that are not the overlapping portion. Is also high.

  FIG. 12 is a conceptual diagram showing the recording duty at the joint portion of the head chip and the mask pattern which is an embodiment of means for achieving the recording duty at the joint portion in Embodiment 1 of the present invention. For the sake of simplicity, this mask pattern diagram is shown with the number of mask patterns actually used being used and the number of recording elements being reduced. Actually, the number of mask patterns is the number of masks corresponding to the recording opportunity when the statistically significant “dominant length” recording medium is conveyed. Here, “●” in the mask pattern in FIG. 12 indicates that recording is performed, and “◯” indicates that recording is not performed using a mask.

  The mask patterns of the head chip 5-a and the head chip 5-b are stored in the ROM that is the storage medium 34 in FIG. The CPU 33 controls the printing apparatus according to this mask pattern.

  In the overlapping portion of the head chip 5-a, the number of recording elements masked increases toward the side where the overlapping ends. Further, the endmost recording element on the side where the overlap starts is not masked and is equal to the recording duty of the recording element which is not the overlapped portion, and the endmost recording element on the side where the overlap ends is all masked and the recording duty is increased. 0%. In the overlapping portion of the head chip 5-b, some of the recording elements on the side where the duplication starts are not masked, and the remaining recording elements on the side where the duplication ends are going to the side where the duplication ends. More recording elements are masked. With such a mask pattern, the recording duty by the recording element at the end on the side where the overlap of the head chip 5-b begins becomes equal to the recording duty by the recording element that is not the overlapping portion. However, the recording duty due to the recording elements in all the other overlapping portions is higher than the recording duty due to the recording elements that are not overlapping portions.

In the first embodiment, recording is performed at a recording duty with respect to the recording element array direction shown in FIG. 11 in the recording apparatus shown in the outline of FIG. 5 having the recording head having the head chip configuration of FIG. 8 and the mask pattern of FIG. went. In addition, PIXUS ip7100 (manufactured by Canon Inc.) was used as the ink, and PR-101 (manufactured by Canon Inc.) was used as the recording medium. As a result, it was possible to achieve the recording without the connecting stripes as shown in the conceptual diagram of the recording image in the recording area by the recording element at the connecting portion in FIG.
[Example 2]
FIG. 13 is a conceptual diagram of a recording head joint portion, a recording duty of the joint portion in the recording element array direction, and a recording image of a recording area by the recording element of the joint portion in Embodiment 2 of the present invention. is there.

  In the second embodiment, the recording with the head chip 5-a is the same as in the first embodiment. Further, the recording by the recording elements in the region from α-b to β-b in the recording element overlapping region of the connecting portion of the head chip 5-b is the same as in the case of the first embodiment. In the recording element in the region from β-b to γ-b in the figure of the head chip 5-b, the recording element is minimized so that γ-b is the side on which the overlap of the recording element rows ends. The recording duty is linearly changed with respect to the column direction. The difference from the first embodiment is that the recording duty in the γ-b region of the head chip 5-b is 0%, and the inclination of the recording duty from β-b to γ-b is steep. It is. Also in Example 2, the total recording duty of the recording elements in the overlapping portion is higher than the recording duty in the portion where each head chip does not overlap except for the recording duty of the recording elements at both ends of the overlapping portion. .

  A mask pattern that achieves the recording duty with respect to the recording element array direction at the connecting portion in FIG. 13 is created, and the mask pattern is stored in the ROM that is the storage medium 34 as in the first embodiment, and is recorded in the CPU 33 according to this mask pattern. The device was controlled.

In Example 2, recording was performed under the same conditions as in Example 1 except for the above conditions. As a result, it was possible to achieve the recording without the connecting stripes as shown in the conceptual diagram of the recording image of the recording area by the recording element in the connecting portion in FIG.
[Example 3]
FIG. 14 is a conceptual diagram of a recording head joint portion, a recording duty of the joint portion in the recording element array direction, and a recording image of a recording area by the recording element of the joint portion in Embodiment 3 of the present invention. is there.

  In the third embodiment, the recording with the head chip 5-b is the same as in the first embodiment. Further, in the recording element overlapping area of the connecting portion of the head chip 5-a, the recording duty changes linearly in the area from α-a to γ-a with respect to the column direction of the recording element array, and the recording duty is thereby changed by the change. The image area is recorded so as to be minimized on the side where the overlap of the columns ends. Note that the recording element at the position γ-a of the head chip 5-a overlaps the recording element at the position β-b of the head chip 5-b with respect to the conveyance direction of the recording medium.

  A mask pattern that achieves the recording duty in the recording element array direction of the connecting portion in FIG. 14 is created, and the mask pattern is stored in the ROM that is the storage medium 34 as in the first embodiment, and is recorded in the CPU 33 according to this mask pattern. The device was controlled.

In Example 3, recording was performed under the same conditions as in Example 1 except for the above conditions. As a result, it was possible to achieve the recording without the connecting stripes as shown in the conceptual diagram of the recording image in the recording area by the recording element at the connecting portion in FIG.
[Example 4]
FIG. 15 is a conceptual diagram of a recording head joint portion, a recording duty of the joint portion in the recording element array direction, and a recording image of a recording area by the recording element of the joint portion in Embodiment 4 of the present invention. is there.

  In the fourth embodiment, the recording with the head chip 5-b is the same as in the first embodiment. The recording with the head chip 5-a is obtained by inverting the recording with the head chip 5-b.

  A mask pattern that achieves the recording duty in the recording element array direction at the connecting portion in FIG. 15 is created, and the mask pattern is stored in the ROM that is the storage medium 34 and is recorded in the CPU 33 according to this mask pattern, as in the first embodiment. The device was controlled.

  In Example 4, recording was performed under the same conditions as in Example 1 except for the above conditions. As a result, it was possible to achieve the recording without the connecting stripes as shown in the conceptual diagram of the recording image of the recording area by the recording element in the connecting portion in FIG.

  In the embodiments of the first to fourth embodiments described above, regarding the recording at the recording ratio in the recording element array direction shown in FIG. 2, it is considered that the recording in the non-overlapping area is shifted to the overlapping area. Can do. In this regard, it has been found that Examples 1 to 3 in which the recording area of one head chip is shifted are particularly effective when the shifting of the recording area is effective with one pixel. In addition, when a plurality of pixels are required to shift the recording area, it was found that Example 4 in which the recording areas of both head chips are shifted is particularly effective.

  The various types of recording methods described above can be summarized as shown in the flowchart of FIG.

  First, in step S1, recording data is input. Next, in step S2, the recording medium is conveyed. Further, in step S3, recording is performed by the recording elements of both the first and second head chips in at least a part of the overlapping area of the first and second head chips. Then, in the area other than the partial area of the overlapping area, the recording is controlled so as to be complementarily recorded by the recording elements of the first and second head chips. This is to increase the recording duty and to make the connecting stripe inconspicuous by recording the recording area at the overlapping portion with the recording elements of both the first and second head chips. By doing so, it is possible to achieve recording without a connecting line in the overlapping area of the recording element arrays.

  In addition, although the above Example is an example of an inkjet recording device and is an especially preferable example, this invention may be another recording device. In particular, among the ink jet recording methods, high density recording is provided using a method for generating thermal energy for discharging ink (for example, an electrothermal converter) and causing the ink state to change by the thermal energy. And high definition can be achieved.

  In addition, the ink jet recording apparatus according to the present invention may be used as an image output apparatus for information processing equipment such as a computer, a copying apparatus combined with a reader, or a facsimile apparatus having a transmission / reception function. It may be one taken.

FIG. 11 is an explanatory diagram of a case where recording is performed while the recording head and the recording medium are relatively moved in a direction inclined from a designed angle. FIG. 4 is a conceptual diagram of a head chip joint portion, a recording duty at a head chip joint portion, and a recorded image of the joint portion when the recording head and the recording medium are relatively moved at an angle as designed. Schematic diagram of head chip joints, recording duty at head chip joints, and recorded images of the joints when the recording head and recording medium move relative to each other in a tilted direction. is there. 10 is a streak evaluation result table for a deviation amount in the recording element array direction for each recording duty when gradation connection image processing is performed for recording in a head chip connection portion. 1 is an external perspective view for explaining a conceptual configuration of an ink jet recording apparatus according to an embodiment of the present invention. It is a front view for demonstrating the notional structure of the inkjet recording device which concerns on one Example of this invention. FIG. 2 is an exploded perspective view illustrating a configuration example of a main part of an inkjet recording head. FIG. 2 is a schematic diagram of a recording head configured by arranging a plurality of head chips each having a recording element array in which recording elements are arrayed so that the recording element arrays are parallel to each other. FIG. 4 is a diagram illustrating an example of a head chip having a plurality of recording element arrays on one head chip that can be preferably used in the present invention. FIG. 2 is a block diagram illustrating a configuration example of a control system in the ink jet recording apparatus as an embodiment of the present invention. FIG. 2 is a conceptual diagram of a head chip joint portion, a recording duty at a head chip joint portion, and a recorded image of the joint portion in Embodiment 1 of the present invention. FIG. 3 is a conceptual diagram of a recording duty at a joint portion of a head chip and a mask pattern at the joint portion in Embodiment 1 of the present invention. FIG. 6 is a conceptual diagram of a head chip joint portion, a recording duty at a head chip joint portion, and a recorded image of the joint portion in Embodiment 2 of the present invention. FIG. 6 is a conceptual diagram of a head chip joint portion, a recording duty at a head chip joint portion, and a recorded image of the joint portion in Embodiment 3 of the present invention. FIG. 10 is a conceptual diagram of a head chip joint portion, a recording duty at a head chip joint portion, and a recorded image of the joint portion in Embodiment 4 of the present invention. It is a flowchart figure showing the recording method of this invention.

Explanation of symbols

1, 2, 3, 4, IJH Inkjet recording head 5, 5-a, 5-b, IT head chip 6, 6-a, 6-b Recording element 22 Heater (electrothermal converter)
23 Heater board 24 Top plate 25 Discharge port 26 Liquid passage 31 Image data input unit 32 Operation unit 33 CPU
34 Storage medium 34a Recording medium information 34b Ink information 34c Environmental information 34d Various control program groups 35 RAM
36 Image processing unit 37 Image storage unit 38 Data bus 5018 Conveying roller 5019 Discharging roller P Recording medium

Claims (3)

The first and second recording element arrays in which a plurality of recording elements are arrayed overlap each other in the transport direction of the recording medium intersecting with the array direction, and the first recording element array An image is recorded by ejecting ink droplets onto the recording medium using a recording head configured such that the region other than the joint portion and the region other than the joint portion of the second recording element array do not overlap each other. A recording device,
Input means for inputting recorded data;
Conveying means for conveying the recording medium in the conveying direction ;
Based on the recording data corresponding to the connecting portion of the recording data input by the input means, the first recording data corresponding to the connecting portion of the first recording element array, and the second recording Data generating means for generating second recording data corresponding to the connecting portion of the element array ;
Recording control means for controlling recording of an image on the recording medium conveyed by the conveying means using the recording head based on the first and second recording data generated by the data generating means ; Have
The data generation unit is configured to record recording data corresponding to the connecting portion of the recording data input by the input unit, and the first and second recording element arrays in the recording direction in the transport direction. Two recordings so that the amount of ink applied in the transport direction by the first and second recording element arrays at the joint portion decreases toward the end of each recording element array. Distribute to data,
With respect to the two recording data, a predetermined number of recording element correspondences are directed in the direction from the center of each of the first recording element array and the second recording element array to the end portion constituting the connecting portion. Generating the first recording data and the second recording data by relatively shifting;
A recording apparatus. The recording apparatus according to claim 1, wherein the predetermined number is one. The first and second recording element arrays in which a plurality of recording elements are arrayed overlap each other in the transport direction of the recording medium intersecting with the array direction, and the first recording element array An image is recorded by ejecting ink droplets onto the recording medium using a recording head configured such that the region other than the joint portion and the region other than the joint portion of the second recording element array do not overlap each other. A data generation method in a recording apparatus ,
An input process for inputting recorded data;
Based on the recording data corresponding to the connecting portion of the recording data input in the input step, the first recording data corresponding to the connecting portion of the first recording element array, and the second recording A data generation step of generating second recording data corresponding to the connecting portion of the element row ,
In the data generation step, the recording data corresponding to the connecting portion among the recording data input in the input step is recorded, and the first and second recording element arrays are recorded in the transport direction in the connecting portion. Two recordings so that the amount of ink applied in the transport direction by the first and second recording element arrays at the joint portion decreases toward the end of each recording element array. Distribute to data,
With respect to the two recording data, a predetermined number of recording element correspondences are directed in the direction from the center of each of the first recording element array and the second recording element array to the end portion constituting the connecting portion. A data generation method characterized in that the first recording data and the second recording data are generated by relatively shifting .

Images