JP2004066742A - Recorder and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform interpolation recording of a pixel being recorded by a defective recording element more effectively using another recording element. <P>SOLUTION: When multipass recording is performed by means of a serial recorder, a plurality of combination tables different in the carrying amount of a recording medium and the combination of recording elements for recording pixels on the same line by a plurality of times of scanning are prepared. Information concerning to a recording element incapable of normal recording is acquired (S401), a combination table to be used is selected among the plurality of combination tables depending on the information thus acquired (S402-S405). When a recording element incapable of normal recording is included in a combination of recording elements for recording pixels on the same line, the pixel being recorded by that recording element incapable of normal recording is recorded using another recording element. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus and a recording method, and in particular, a recording apparatus that performs recording by scanning a recording head having a plurality of recording elements arranged in a predetermined direction on the recording medium in a direction crossing the conveyance direction of the recording medium. And a recording method.
[0002]
[Prior art]
For example, as information output devices in word processors, personal computers, facsimiles, and the like, printers that record desired information such as characters and images on a sheet-like recording medium such as paper or film are widely used.
[0003]
Various printer recording methods are known, but there are wire dot methods, thermal methods, thermal transfer methods, ink jet methods, and the like. In particular, ink jet methods directly eject ink onto recording paper. Therefore, it has been attracting attention as a method that can perform a recording operation with low running cost and excellent quietness.
[0004]
Further, as a configuration thereof, recording (scanning) is performed while moving a carriage on which a recording head is mounted in a direction intersecting with the conveyance direction of the recording medium. In general, the serial type is inexpensive and easy to downsize. Widely used. In such a serial type ink jet printer, after a plurality of nozzles provided in the recording head are driven based on the recording information during the scanning of the carriage, the recording area is recorded by one scanning. The recording medium is conveyed by the width of the recording area in a direction intersecting the scanning direction of the carriage, and a desired image is recorded by alternately performing the scanning and the conveyance of the recording medium.
[0005]
The recording head is provided with a number of nozzles (ejection ports) for ejecting ink droplets, and the nozzles are filled with ink used for recording on a recording medium. In the case of recording an image or the like, a nozzle to be driven corresponding to the image data is selected as appropriate, and recording is performed by ejecting ink droplets from the selected nozzle.
[0006]
In general, a discharge section (nozzle) for discharging a liquid such as ink has a very fine structure, and thus a state in which a dye or pigment mixed in the ink is fixed or a foreign matter adheres causes a discharge failure. Sometimes. Therefore, in a liquid ejection apparatus such as an ink jet recording apparatus, correct recording cannot be performed due to ejection failure.
[0007]
In order not to cause such a problem, liquid is forcibly discharged by suction, pressurization, etc., the surface of the discharge part is cleaned, or gas or liquid is discharged to the discharge area of the discharge part at appropriate intervals. A so-called recovery operation is performed.
[0008]
In the ink jet recording apparatus, high quality and high resolution recording is desired due to the nature of the recording apparatus, and the nozzles used are becoming finer. Since a fine nozzle is used, recording becomes unstable due to the problems described above, and the recorded image is deteriorated.
[0009]
If the classification is based on the deterioration of the recorded image, the ink ejection direction becomes unstable, the ink droplet landing position is slightly different, and the recording is caused by clogging of the ejection port (nozzle) due to dust or thickened ink. Discharge failure, discharge failure due to disconnection of heater in bubble jet (registered trademark) system that generates air bubbles in ink using an electrical / thermal converter (heater), and ink droplets are on the discharge port surface There is a discharge failure that occurs when the discharge port adheres to the discharge port and covers the discharge port.
[0010]
Due to the occurrence of such discharge defects, lines that are not recorded in the scanning direction are generated in the serial printer, and appear as white stripes in the recorded image, which greatly deteriorates the recorded image. It was.
[0011]
Such a problem is that when the number of nozzles is increased to several hundreds or thousands in order to increase the recording throughput, the probability that a defective nozzle is generated increases in proportion to the number of nozzles. It becomes even more difficult to obtain.
[0012]
Further, from the viewpoint of manufacturing a recording head, conventionally, there has been a demand for a recording head in which all nozzles are normal and free from defects. However, when the number of nozzles is increased as described above, the probability of occurrence of defective nozzles during production increases in proportion thereto, resulting in a decrease in manufacturing yield and an increase in manufacturing cost.
[0013]
Conventionally, even if a recording head having no defect at the time of manufacture is used, if one of the many nozzles fails in the process of being used for recording, that nozzle is used for recording. Unusable. For this reason, in a recording apparatus that performs recording with a multi-nozzle head having a large number of nozzles, an abnormality may occur in any of the nozzles, and a recording defect will occur each time.
[0014]
In addition, not only in the ink jet recording method, in a recording apparatus that forms an image on a recording medium using various recording elements, when the recording element becomes unrecordable due to damage or the like, some dots in the recorded image It is necessary to continue recording with the knowledge that recording is no longer recorded, or to stop recording and restore the recording state by replacing the recording head.
[0015]
On the other hand, for example, as disclosed in JP-A-10-006488 and JP-A-2000-94662, one raster recording is performed with a plurality of nozzles, and even if there are defective nozzles. However, a recording method that complements using other normal nozzles has been proposed.
[0016]
In Japanese Patent Laid-Open No. 2000-94662, in multi-pass printing in which each raster is completed by N scans, one raster printing is completed using N nozzles. A recording method has been proposed in which even if there are defective nozzles, the other nozzles are used for complementation.
[0017]
[Problems to be solved by the invention]
However, the conventional methods as described above have the following problems when avoiding a recording failure due to a defective nozzle.
[0018]
For example, in the case of detecting a defective nozzle and performing complementary recording using a separately prepared complementary nozzle, it is necessary to provide a preliminary interpolation nozzle in the recording head in advance, which hinders the downsizing of the recording head. In addition, the cost of the recording head, which is a consumable item, increases.
[0019]
In addition, even with this method, if an interpolation nozzle corresponding to a defective nozzle is also defective, complementary recording cannot be performed.
[0020]
Also, in multi-pass printing, even if there are defective nozzles, even if there is a printing method that complements using other nozzles, if all the multiple nozzles used for printing the same raster are defective, complementary printing is performed. Can not do.
[0021]
In addition, even when all nozzles that record the same raster in this method have defects, for example, if three nozzles out of four nozzles that record the same raster in four-pass recording have defects, the remaining 1 Since complementary recording is performed up to the recording with other nozzles using one normal nozzle, the frequency of use of one normal nozzle is increased, and the life of the nozzle is extremely shortened. As a result, four nozzles There is a high possibility that everything will be in a defective state and cannot be complemented.
[0022]
The present invention has been made in view of the above situation, and a recording apparatus capable of performing more effective and effective interpolation recording of pixels recorded by a defective recording element with other recording elements, and An object is to provide a recording method.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, a recording apparatus according to the present invention performs recording by scanning a recording head having a plurality of recording elements arranged in a predetermined direction on the recording medium in a direction crossing the conveyance direction of the recording medium. A device,
When performing multi-pass printing in which printing is performed by performing relative movement of the print head a plurality of times for each print area, pixels on the same line are printed by the carry amount of the print medium and the plurality of scans Storage means for storing a plurality of combination tables with different combinations of recording elements;
Undischarge information acquisition means for acquiring information about a recording element that cannot perform normal recording; and selection means for selecting a combination table to be used from the plurality of combination tables according to the acquired information;
When a combination of recording elements that record pixels on the same line includes recording elements that cannot perform normal recording, the pixels that should be recorded by the recording elements that cannot perform normal recording are recorded by other recording elements. And a recording control means for controlling.
[0024]
Further, the recording method of the present invention that achieves the above object is a recording method in which recording is performed by causing a recording head having a plurality of recording elements arranged in a predetermined direction to scan on the recording medium in a direction intersecting the conveyance direction of the recording medium. A method,
When performing multi-pass printing in which printing is performed by performing relative movement of the print head a plurality of times for each print area, pixels on the same line are printed by the carry amount of the print medium and the plurality of scans A table preparation step of preparing a plurality of combination tables having different combinations of recording elements;
An undischarge information acquisition step of acquiring information about a recording element that cannot perform normal recording; a selection step of selecting a combination table to be used from the plurality of combination tables according to the acquired information;
When a combination of recording elements that record pixels on the same line includes recording elements that cannot perform normal recording, the pixels that should be recorded by the recording elements that cannot perform normal recording are recorded by other recording elements. A recording control process for controlling the recording.
[0025]
That is, according to the present invention, in a recording apparatus that performs recording by scanning a recording head having a plurality of recording elements arranged in a predetermined direction on the recording medium in a direction intersecting the conveyance direction of the recording medium, When performing multi-pass printing in which printing is performed by moving the print head a plurality of times, a plurality of print medium conveyance amounts and combinations of printing elements that print pixels on the same line in a plurality of scans are different. A recording element that prepares a combination table, acquires information about a recording element that cannot perform normal recording, selects a combination table to be used from a plurality of combination tables according to the acquired information, and records pixels on the same line If the combination includes a recording element that cannot perform normal recording, the pixel to be recorded by the recording element that cannot perform normal recording is recorded by another recording element. To control to.
[0026]
In this way, when performing multi-pass recording with a serial type recording apparatus, even if there are a plurality of recording elements that cannot perform normal recording, the combination of recording elements that record pixels on the same line does not perform normal recording. A combination table that does not allow recording elements that cannot be performed can be selected, and when the recording elements that record pixels on the same line include recording elements that cannot perform normal recording, recording is performed with recording elements that cannot perform normal recording. The pixel to be recorded can be recorded by another recording element.
[0027]
Therefore, effective and efficient interpolation recording can be performed when recording is performed with a recording head having a recording element that cannot perform normal recording.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0029]
In the embodiment described below, an ink jet printer using an ink jet recording method will be described as an example of a recording apparatus according to the present invention.
[0030]
In this specification, “recording” (sometimes referred to as “printing”) is not only for forming significant information such as characters and graphics, but also for human beings, regardless of whether it is significant or not. Regardless of whether or not it has been manifested, it also represents a case where an image, a pattern, a pattern or the like is widely formed on a recording medium or the medium is processed.
[0031]
“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.
[0032]
Furthermore, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly in the same way as the definition of “recording (printing)” above. It represents a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing an ink (for example, solidification or insolubilization of a colorant in ink applied to the recording medium).
[0033]
First, a configuration of a recording apparatus common to the following embodiments will be described.
[0034]
<Outline of recording device>
This recording apparatus is a color recording apparatus adopting an ink jet method, and the main part thereof has a recording means 200a having a structure as shown in FIG. In FIG. 1, reference numeral 1 denotes a recording sheet as a recording medium made of paper or a plastic sheet, which is stored in a stacked state in a cassette or the like, and the top or bottom of the stacked sheet bundle. A sheet feeding roller (not shown) in contact with one surface of the recording sheet 1 is rotated so that recording sheets are supplied one by one from the cassette, and are arranged on the platen at a predetermined interval. The recording sheet 1 arranged on the platen is in the direction of arrow A (sub-scanning direction) by a pair of first conveying rollers 3 and a pair of second conveying rollers 4 driven by individual stepping motors (not shown). It is designed to be conveyed.
[0035]
A carriage 6 is provided so as to be linearly reciprocable along a horizontal guide shaft 9 held in the main scanning direction crossing the sub-scanning direction A. The carriage 6 is connected via a belt 7 and pulleys 8a and 8b. The carriage motor 23 is linked to the carriage motor 23, and the carriage motor 23 is driven to reciprocate along the guide shaft 9. The carriage 6 is provided with an ink jet recording head 5 for recording on the recording sheet 1 and an ink cartridge (not shown) for supplying ink to the head. Here, as the recording head, there are four types of recording heads for discharging inks of four colors of C (cyan), M (magenta), Y (yellow), and K (black), and ink cartridges that supply ink to these. Each of the C, M, and Y recording heads has 1280 nozzles, and K has 640 nozzles.
[0036]
In the recording means 200a having the above configuration, the recording head 5 ejects ink onto the recording sheet 1 in accordance with the recording signal while moving in the main scanning direction (arrow B direction), and the number of nozzles of the recording head in the sub-scanning direction. Recording is performed in a recording area having a corresponding width. If necessary, the recording head 5 returns to the home position, and the ink recovery device eliminates clogging of the nozzles, and the pair of conveying rollers 3 and 4 drive the recording sheet 1 in the direction of the arrow A. Carries only the width. In addition, a preliminary discharge port (not shown) for performing preliminary discharge is provided on both sides of the recording sheet 1 in the main scanning direction, and preliminary discharge is performed regardless of the reciprocal direction in each scanning scan. It can be carried out. By repeating this operation, an ink image composed of a predetermined number of rasters is formed on the recording sheet 1.
[0037]
Further, in order to recover the ejection performance of the recording head 5, the difference between the recording head returning to the home position covers the ejection port surface to prevent ink evaporation, and the recovery operation is performed by a suction pump (not shown). There is provided a recovery mechanism 10 having a cap and a blade for cleaning dust adhering to the surface of the discharge port, fixed ink, or the like.
[0038]
Next, a control system of the recording apparatus 200 having the recording means 200a will be described with reference to FIG.
[0039]
As shown in FIG. 2, this control system is used as a control program executed by the CPU 20a such as a microprocessor and a ROM 20c storing various data, and as a work area of the CPU 20a and various data such as recorded image data. An arithmetic control unit 20 having a RAM 20b and the like for temporarily storing the image is provided. The arithmetic control unit 20 includes an interface 21, an operation panel 22, motors (carriage motor 23, paper feed motor 24, first transport roller drive motor). 25, a driver 27 for driving the second transport roller driving motor 26) and a driver 28 for driving the recording head are connected.
[0040]
The arithmetic control unit 20 performs input / output (information input / output) of various information (for example, character pitch, character type, etc.) from an after-mentioned host 201 and an image signal with an external device via the interface 21. Further, the control unit 20 outputs ON / OFF signals and image signals for driving the motors 23 to 26 through the interface 21 and drives each unit by the image signals.
[0041]
<Image processing device overview>
Next, a recording information processing apparatus that generates recording signal data for causing the recording apparatus 200 to perform a recording operation will be described.
[0042]
FIG. 3 is a diagram showing a schematic configuration of a host computer (hereinafter simply referred to as a host) as an information processing apparatus in each embodiment of the present invention. In the figure, a host 201 includes a CPU 202, a memory 204 (recording information generating means), an external storage device 203, an input unit 205, and an interface 206 with the recording device 202. The CPU 202 executes various operations such as calculation, determination, and control by executing a program stored in the memory 204, and realizes color processing, quantization processing, correction processing, and the like described later. Functions as calculation means, recording signal correction means (first and second correction means), and the like. This program and recorded information are stored in the external storage device 203, read from this, supplied to the CPU 202, and temporarily stored in the memory 204. The host 201 is connected to the recording device 202 via an interface 206, and transmits image data subjected to color processing to the recording device 202 to execute a recording operation.
[0043]
FIG. 4 is a functional block diagram illustrating functions of the image processing unit 230 realized by the host 201. The image processing unit 230 outputs input R, G, B color image data of 8 bits (256 gradations) as C, M, Y, K color 1 bit data. The unit 210 and the quantization unit 220 are included. The color processing unit 210 includes a color space conversion processing unit 211, a color conversion processing unit 212, and an output γ processing unit 213. Among these, the color space conversion processing unit 211 and the color conversion processing unit 212 are configured by a three-dimensional LUT (lookup table), and the output γ processing unit 213 is configured by a one-dimensional LUT (lookup table). Each LUT is stored in the memory 204 in the host computer 201.
[0044]
In the image processing unit 230 having the above configuration, R, G, B color bit data read from the external storage device 203 is first converted into R ′, G ′, B ′ color 8-bit data by a three-dimensional lookup table. Is done. This processing is called color space conversion processing (previous color processing), and is conversion processing for correcting the difference between the color gamut (color space) of the input image and the reproduction color space of the output device. The R ′, G ′, B ′ color 8-bit data subjected to this color space conversion processing is converted into C, M, Y, K color 8-bit data by the following three-dimensional LUT. This color conversion processing is referred to as post-stage color processing, and is conversion processing for correcting the difference between the color space of the input image (color space) and the reproduction color space of the output device.
[0045]
Further, the 8-bit data of each color R ′, G ′, B ′ subjected to the previous color processing is converted into 8-bit data of each color C, M, Y, K by the three-dimensional LUT constituting the next color conversion processing unit 212. Is done. This color conversion process is referred to as post-stage color processing, and is a process of converting from an input RGB color to an output C, M, Y, K color. The input image data is often the three primary colors (R, G, B) of the additive color mixture of the light emitter such as a display. However, when the color is expressed by reflection of light such as a printer, the three primary colors of the subtractive color mixture are used. Since color materials of the system (C, M, Y) are used, such a color conversion process is necessary.
[0046]
The three-dimensional LUT used for the pre-stage color processing and the three-dimensional LUT used for the post-stage color processing hold data discretely, and the obtained data is obtained by interpolation processing. Therefore, detailed description regarding the interpolation processing is omitted here.
[0047]
Thereafter, the output γ correction is performed on the 8-bit data of each color C, M, Y, and K subjected to the subsequent color processing by the one-dimensional LUT constituting the output γ processing unit 213. Since the relationship between the number of recording dots per unit area and the output characteristics (reflection density, etc.) is not a linear relationship in many cases, by applying output γ correction, the input levels of C, M, Y, and K8 bits and at that time Guarantees a linear relationship with the output characteristics of The above is a schematic description of the image processing unit 201.
[0048]
<Interpolation recording in multi-pass recording>
FIG. 5 is a diagram for explaining a general multipass recording method. In the illustrated example, this is the case of 4-pass printing.
[0049]
In the recording head 100, 16 nozzles 101 to 116 are arranged from bottom to top in the figure. In the case of four-pass printing, the recording head is moved in the main scanning direction to perform recording scanning, and then a four-nozzle paper feeding operation is performed in the sub-scanning direction. The recording area 120 is an area recorded in four passes, and is divided into a vertical 4 × width 24 area corresponding to each pixel. The 16 nozzles are divided into 4 blocks of A, B, C, and D, and when recording in the recording area 120, the blocks are used in the order of B, C, D from A, The recording of the image is completed by performing the recording scan four times.
[0050]
Here, when attention is paid to one raster 121 displayed in gray in the recording area 120, in order to complete an image of the area of this one raster, the recording head 100 first performs main scanning in the first recording scan (one pass). Scanning is performed in the direction, and recording is performed on predetermined pixels by the nozzle 101 of the A block. Next, four-nozzle paper feeding is performed in the sub-scanning direction intersecting the main scanning direction, the second recording scan (two passes) is performed, and recording is performed by the B block nozzle 105. Similarly, in the third recording scan (three passes) after feeding four nozzles again, recording is performed using the nozzle 109 of the C block, and the fourth recording scan (four passes after feeding four nozzles again). In (4 passes), recording is performed by the nozzle 113 of the D block, and the recording to a predetermined pixel in the raster is completed.
[0051]
Thus, in the case of 4-pass printing, printing is performed in the printing area of the raster 121 using four nozzles 101, 105, 109, and 113.
[0052]
In FIG. 5, pixels are designated by assigning indices such as L1 to L24 in the horizontal direction with respect to the raster 121 displayed in gray in the recording area 120, but in each scan for the raster 121 displayed in gray. FIG. 6 shows the state of recording.
[0053]
FIG. 6A shows a state of printing in each of the first to fourth scans when all four nozzles used for printing of the raster 121 are normal. Here, the nozzle 101 records pixels of 4N + 1 (N = 0, 1, 2,...) In the first recording scan, the nozzle 105 records pixels of the nozzle 4N + 2 in the second recording scan, and the nozzle 109 in the third recording scan. Shows a case where 4N + 3 pixels are recorded, and the nozzle 113 records 4N + 4 pixels in the fourth recording scan.
[0054]
Here, it is assumed that the nozzle 101 is a defective nozzle (undischarge nozzle). FIG. 6B shows the state of printing in each scan when the nozzle 101 is a non-discharge nozzle. In this case, 4N + 1 pixels that should be recorded in the first recording scan are not recorded, and are blank. Such a recording failure is particularly noticeable in a solid portion or the like.
[0055]
FIG. 6C shows a state in which complementary recording is performed using other nozzles in order to prevent such a recording failure. The interpolation recording shown here is an example in which the pixels to be recorded by the nozzle 101 are recorded by the nozzle 105. Accordingly, the pixels recorded by the nozzle 101 in the second recording scan are recorded in addition to the pixels originally recorded by the nozzle 105.
[0056]
By performing such supplementary recording, it is possible to record all data to be recorded. In this case, supplementation is performed using the nozzle 105, but it is needless to say that supplementary recording may be performed using either the nozzle 109 or 113. Further, the complementary recording may be performed by dividing the pixel to be recorded by the nozzle 101 by the three nozzles 105, 109, and 113, or any two nozzles.
[0057]
When performing multi-pass printing, the total number of nozzles of the print head is divided into the number of scans (number of passes), for example, 2 blocks for 2-pass printing and 4 blocks for 4-pass printing, and one printing scan. In general, paper is fed by the number of nozzles belonging to each block. For example, the total number of nozzles of the print head is 16 nozzles, and the paper feed amount when using all the nozzles is 8 nozzles for 2-pass printing, 4 nozzles for 4-pass printing, and 2 nozzles for 8-pass printing Minutes.
[0058]
FIG. 7 shows a combination of nozzles when the number of nozzles is 16 and 2-pass (a), 4-pass (b), and 8-pass (c) multi-pass printing is performed. As is clear from this figure, when performing multi-pass printing with a constant paper feed amount, the combination of a plurality of nozzles for printing one raster is always constant and does not change. For example, in the case of the two-pass printing shown in (a), since the raster printing recorded by the nozzle number 3 in the first printing scan has a paper feed amount of 8 nozzles, the nozzle number 11 is always used in the second printing scan. Recording will be done. Even in the case of the 4-pass printing shown in (b), since the paper feed amount is equivalent to 4 nozzles, for example, in the raster printing in which the nozzle number 3 is recorded in the first printing scan, the nozzle number 7 is set in the second printing scan, In the third recording scan, nozzle number 11 is recorded, and in the fourth recording scan, nozzle number 15 is recorded. The same applies to 8-pass printing.
[0059]
Therefore, for example, in the combination shown in FIG. 7A, when nozzle number 3 is a non-discharge nozzle in two-pass printing, complementary recording is performed if nozzle number 11 is a normal nozzle. However, if the nozzle number 11 is also a discharge failure nozzle, complementary recording is impossible. That is, when all the nozzles in the combination that record the same raster are non-discharge nozzles, complementary recording cannot be performed.
[0060]
Further, for example, in the combination shown in FIG. 7B, when nozzle numbers 3, 7 and 11 are non-ejection nozzles in 4-pass printing, nozzle number 3 is used in the fourth printing scan. , 7 and 11 can be used for complementary recording by recording all the data to be recorded, but in this case, nozzle number 15 performs recording four times as many as other nozzles. At the time of recording, an operation of driving the nozzles to eject ink droplets is performed. In the process of repeating this operation, the characteristics of the nozzles deteriorate and change over time. Specifically, it appears as ejection amount fluctuation, ink droplet deflection, and irregular ejection. When the number of discharges exceeds a certain number, the heater in the nozzle may be disconnected and discharge may not occur. For this reason, the nozzles used for complementation are used more frequently than other nozzles, and the above-described deterioration of the nozzle characteristics occurs at an early stage.
[0061]
(First embodiment)
Hereinafter, a first embodiment according to the present invention that compensates for the disadvantages of interpolation recording in such conventional multi-pass recording will be described.
[0062]
In the first embodiment of the present invention, combinations of nozzles that perform printing of the same raster are not discharged nozzles or the number of combinations that are discharged nozzles is reduced.
[0063]
FIG. 8 is a diagram showing combinations of nozzle numbers for recording one raster corresponding to the number of used nozzles and the feed amount in the two-pass printing in the present embodiment. Note that the total number of nozzles of the recording head of the present embodiment is 20, and the number of used nozzles means the number of nozzles actually used for recording out of the total number of nozzles. Each number in FIG. 8 indicates a nozzle number, and each combination of (a) to (e) is referred to as an undischarge head rank table, and an undischarge head rank table number is designated as T (1) to T (5). Is allocated.
[0064]
These undischarge head rank tables may be stored in the ROM in advance, or a table corresponding to a multipass recording mode that can be executed by the printing apparatus from a printer driver installed in a host device connected to the printing apparatus. The information may be received and stored in the RAM.
[0065]
Here, it is assumed that nozzle numbers 3 and 11 are undischarge nozzles. In FIG. 8, these two nozzle numbers are displayed in gray. In the case of the undischarge head rank table 3 shown in FIG. 8C, the same raster is recorded by combining the nozzle numbers 3 and 11 which are undischarge nozzles, and complementary recording cannot be performed. However, in each of the discharge failure head rank tables (a), (b), (d), and (e), a combination of recording the same raster between discharge failure nozzles is not possible, so that complementary recording is possible.
[0066]
FIG. 9 shows a case where, in the undischarge head rank table shown in FIG. 8, the nozzle numbers 1 and 4 are also non-discharge nozzles in addition to the nozzle numbers 3 and 11. Again, the undischarge nozzle number is displayed in gray. In this case, since the number of ejection failure nozzles is large, there is a raster that is recorded between ejection failure nozzles in two printing scans other than the combination of ejection failure head rank tables shown in (a) and (d). In other words, in the example shown in FIG. 9, complementary recording is possible by selecting one of the combinations of the undischarge head rank table of (a) and (d).
[0067]
Hereinafter, the determination method of the undischarge head rank table with respect to the position information of the non-discharge nozzle executed in the present embodiment will be described with reference to the flowchart of FIG.
[0068]
First, in step S401, an undischarge nozzle number is acquired as position information of an undischarge nozzle in the recording head. This nozzle number is assumed to be assigned to all nozzles provided in the recording head.
[0069]
Next, in step S402, all the discharge failure rank tables T (1) to T (Max) stored in the ROM or RAM of the recording apparatus are referred to.
[0070]
In step S403, the acquired ejection failure nozzle number is compared with the ejection failure rank tables T (1) to T (Max), and a combination in which the ejection failure nozzles record the same raster in two printing scans is searched. And count that number. For example, when there are two such combinations in the discharge failure rank table 1, K (1) = 2 is obtained as the count value of the discharge failure rank table 1, and this count is obtained for all discharge failure rank tables. Find the value.
[0071]
Next, in step S404, the calculated count values from K (1) to K (Max) are respectively compared, and the lowest count value is selected. At this time, when there are a plurality of count values having the lowest value, the count value having the largest table number N is selected.
[0072]
Here, as the reason for selecting the largest table number, as shown in FIG. 8 and FIG. 9, in this embodiment, the larger the table number, the more the recording paper feed amount is used in one scan. This is because there are a large number of nozzles, and as a result, the recording speed is higher.
[0073]
In this embodiment, the lowest count value is selected from the calculated count values. If the count value is not zero, it means that there is a combination in which undischarge nozzles overlap. Therefore, if there is no count value of 0, it may be determined that the recording head is unusable and an error signal may be output.
[0074]
Finally, in step S405, for example, if the selected count value is K (2), R (2) is determined as the undischarge head rank corresponding to the undischarge head rank table 2, and the corresponding undischarge head rank is determined. A table is selected and the number of nozzles to be used and the feed amount are determined.
[0075]
The method for determining the undischarge head rank table based on the position information of the undischarge nozzle executed in the present embodiment has been described above.
[0076]
Further, the undischarge head rank table as shown in FIGS. 8 and 9 is prepared for each multi-pass printing mode having a different number of passes, and the undischarge head rank table is determined for each recording mode.
[0077]
<Modification>
The above description has been given for the case of two-pass printing. However, in the case of multi-pass printing of four or more passes, the count value is calculated when calculating the value of K (N) in step S403 of the flowchart of FIG. Perform weighting.
[0078]
For example, in the case of four-pass printing, undischarge head rank tables T (1) to T (3) as shown in FIGS. 11A to 11C are prepared, and nozzle numbers 3 and 3 are set as undischarge nozzles. Assume that 4, 7, and 11 have been detected. When attention is paid to T (1) shown in (a), two undischarge nozzles of nozzle numbers 4 and 7 are used for recording the same raster. Thus, when two undischarge nozzles overlap the same raster recording, 1 is added to the count value. When attention is paid to T (2), the three undischarge nozzles of nozzle numbers 3, 7, and 11 overlap the same raster recording. Thus, when three undischarge nozzles overlap the same raster recording, 5 is added to the count value. In this way, the count value is weighted according to the number of undischarge nozzles overlapping, and the head rank table to be used is determined by the accumulation of the count value.
[0079]
Further, although not shown, when four undischarge nozzles overlap the same raster recording, a large value such as 15 may be added to the count value. Alternatively, in this case, since there is a raster that cannot be complementarily recorded, it may be determined that this recording head is unusable and an error signal may be output.
[0080]
(Second Embodiment)
Hereinafter, a second embodiment according to the present invention will be described. In the following description, the description of the same parts as those of the first embodiment will be omitted, and the characteristic parts of the present invention will be mainly described.
[0081]
In the first embodiment, the position information of the discharge failure nozzle is detected in advance, and this position information (nozzle number) is acquired to determine the head rank table used for recording. In the present embodiment, the recording apparatus has an undischarge nozzle detection function, and detects an undischarge nozzle number using this function.
[0082]
A method for determining the undischarge head rank table in the present embodiment will be described with reference to the flowchart of FIG.
[0083]
First, in step S501, an undischarge nozzle number is specified using the undischarge nozzle detection function provided in the recording apparatus.
[0084]
Next, in step S502, an undischarge nozzle number is acquired from the detection result. Steps S503 to S506 are the same as S402 to S405 in the first embodiment, and a description thereof will be omitted.
[0085]
Since the present embodiment has the function of detecting an undischarge nozzle as described above, for example, the non-discharge nozzle is detected every time recording on A41 sheets of recording medium is completed, and the undischarge nozzle information is detected. Thus, the undischarge head rank table to be used can be determined. In this way, it is possible to cope with ejection failures that occur in the process of performing the recording operation, and as a result, even when a large number of undischarge nozzles occur in the recording head, the maximum complementary recording can be performed. It is possible to suppress the recording failure.
[0086]
The timing for detecting the undischarge nozzle is not particularly limited. For example, the number of dots recorded by the recording head may be counted, and the detection may be performed when the count value exceeds a certain threshold value, or suction. For example, detection may be performed when the recovery operation of the recording head is performed, and the undischarge head rank table to be used may be determined. Alternatively, the discharge failure head rank table may be determined by performing detection for each data output from the printer server, that is, for each job.
[0087]
In addition, about the non-discharge nozzle detection function in this embodiment, what is necessary is just to identify the nozzle which generate | occur | produced non-discharge, and the detection method, a specific method, etc. are not specifically limited.
[0088]
For example, a recorded pattern is read by an optical sensor or the like provided inside the recording apparatus, and a discharge failure nozzle is detected from the result, or an operating state of nozzle driving means such as a heater provided inside the recording head is determined. The method for detecting undischarge nozzles, the method for identifying the nozzles that failed to discharge and the undischarge nozzles using an inspection device different from the recording device, and the user visually judging the recorded pattern In addition, a method for the user himself / herself to input the number of the nozzle determined to be non-ejection is known, and any of these methods can be applied to the present embodiment.
[0089]
(Third embodiment)
The third embodiment according to the present invention will be described below. In the following description, the description of the same parts as those in the first and second embodiments will be omitted, and the characteristic parts of the present invention will be mainly described.
[0090]
Although the first embodiment has been described, the nozzle characteristics are deteriorated in the process of repeatedly ejecting ink droplets in order to perform recording, and change with time. Therefore, the nozzles used for complementation are used more frequently than other nozzles, and the deterioration of the nozzle characteristics occurs early.
[0091]
In this embodiment, in order to solve such a problem, an undischarge head rank table to be used is switched, and the method will be described below.
[0092]
That is, in this embodiment, for each multi-pass recording mode, a plurality of undischarge head rank tables are determined as undischarge head rank tables to be used, and the undischarge head rank tables to be used are switched at a predetermined timing.
[0093]
The case of the two-pass printing mode will be described as an example. When there are two undischarge head rank tables in which the combination of nozzles that record the same raster does not become undischarge nozzles, the numbers of these two undischarge head rank tables And one undischarge head rank is selected as the undischarge head rank table to be used first.
[0094]
As described above, when the same undischarge head rank table is used all the time, the nozzle used for complementation deteriorates earlier than other nozzles. In order to avoid this, the undischarge head rank table used for recording is switched to the other at a predetermined timing. The timing for switching may be the timing after the recording of one A4 recording medium is completed, the number of dots recorded by the recording head, and when the count value reaches a certain threshold or more, or is output from the printer server. Switching may be performed for each data, that is, for each job. In this case, the two head ranks may be alternately switched at each timing.
[0095]
In the case of other multi-pass printing modes, the undischarge head rank table using two undischarge head rank tables is selected and stored from the ones having a small count value described in the first embodiment, It may be switched at the timing.
[0096]
Further, the number of undischarge head rank tables to be switched is not limited to two, but may be three or more.
[0097]
(Other embodiments)
In the above embodiment, the case where the present invention is applied to a color recording apparatus adopting the ink jet system has been described, but the present invention can also be applied to a recording apparatus employing a recording system other than the ink jet system.
[0098]
That is, the recording method is not limited as long as the recording apparatus performs recording by moving a recording head having a plurality of recording elements relative to the recording medium.
[0099]
The above embodiment includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for performing ink discharge, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.
[0100]
As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and applying a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed.
[0101]
By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus liquid (ink) discharge with particularly excellent responsiveness can be achieved.
[0102]
As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0103]
As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, liquid path, and electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations described in U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an opening that absorbs a pressure wave of thermal energy is discharged to a plurality of electrothermal transducers. A configuration based on Japanese Patent Laid-Open No. 59-138461 disclosing a configuration corresponding to each part may be adopted.
[0104]
In addition to the cartridge-type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being mounted on the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.
[0105]
In addition, it is preferable to add recovery means for the recording head, preliminary means, etc. to the configuration of the recording apparatus described above, since the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressure or suction unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.
[0106]
Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.
[0107]
In the embodiment described above, the description is made on the assumption that the ink is a liquid. However, even if the ink is solidified at room temperature or lower, it may be softened or liquefied at room temperature. Alternatively, the ink jet method generally controls the temperature of the ink so that the viscosity of the ink is within a stable discharge range by adjusting the temperature within a range of 30 ° C. or higher and 70 ° C. or lower. It is sufficient if the ink sometimes forms a liquid.
[0108]
In addition, it is solidified in a stand-by state in order to actively prevent temperature rise by heat energy as energy for changing the state of ink from the solid state to the liquid state, or to prevent ink evaporation. Ink that is liquefied by heating may be used. In any case, by applying heat energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used.
[0109]
In such a case, the ink is held as a liquid or solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260, It is good also as a form which opposes with respect to an electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0110]
Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even if it is applied to a system composed of a plurality of devices (eg, a host computer, interface device, reader, printer, etc.) You may apply. Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.
[0111]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.
[0112]
As a storage medium for supplying the program code, for example, a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.
[0113]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.
[0114]
Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0115]
When the present invention is applied to the above-described storage medium, the storage medium stores program codes corresponding to the flowcharts described above (shown in FIG. 10 and / or FIG. 12).
[0116]
【The invention's effect】
As described above, according to the present invention, when performing multi-pass printing with a serial type printing apparatus, a combination of printing elements for printing pixels on the same line even if there are a plurality of printing elements that cannot perform normal printing. However, if a combination table that does not allow recording elements that cannot perform normal recording can be selected and the combination of recording elements that record pixels on the same line includes recording elements that cannot perform normal recording, this normal recording A pixel to be recorded by a recording element that cannot perform recording can be recorded by another recording element.
[0117]
Therefore, effective and efficient interpolation recording can be performed when recording is performed with a recording head having a recording element that cannot perform normal recording.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing a main part mechanism of a recording apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of a control system of the recording apparatus illustrated in FIG.
3 is a diagram showing a schematic configuration of a host computer as an information processing apparatus for the recording apparatus of FIG. 1;
4 is a functional block diagram illustrating functions of an image processing unit realized by the host computer of FIG. 3. FIG.
FIG. 5 is a diagram for explaining a recording method of multi-pass recording.
FIG. 6 is a diagram for explaining complementary recording in multi-pass recording.
FIG. 7 is a diagram showing combinations of the number of used nozzles and paper feed amount in multi-pass printing and nozzle numbers for printing the same raster.
FIG. 8 is a diagram illustrating an undischarge head rank table for two-pass printing according to the first embodiment of the present invention.
FIG. 9 is a diagram illustrating an undischarge head rank table for two-pass printing according to the first embodiment of the present invention.
FIG. 10 is a flowchart illustrating a method for determining an undischarge head rank table according to the first embodiment of the present invention.
FIG. 11 is a diagram illustrating an undischarge head rank table for four-pass printing according to the first embodiment of the present invention.
FIG. 12 is a flowchart illustrating a method for determining an undischarge head rank table according to the second embodiment of the present invention.
[Explanation of symbols]
1 paper
6 Carriage
5, 100 Recording head
101-116 nozzles
120 recording area
121 raster
200 Recording device
200a Recording means
201 hosts
202 CPU
204 memory
230 Recording information processing
213 Output γ processing section

Claims (12)

A recording apparatus that performs recording by causing a recording head having a plurality of recording elements arranged in a predetermined direction to scan on a recording medium in a direction that intersects the conveyance direction of the recording medium,
When performing multi-pass printing in which printing is performed by performing relative movement of the print head a plurality of times for each print area, pixels on the same line are printed by the carry amount of the print medium and the plurality of scans Storage means for storing a plurality of combination tables with different combinations of recording elements;
Undischarge information acquisition means for acquiring information about a recording element that cannot perform normal recording;
A selection means for selecting a combination table to be used from the plurality of combination tables according to the acquired information;
When a combination of recording elements that record pixels on the same line includes recording elements that cannot perform normal recording, the pixels that should be recorded by the recording elements that cannot perform normal recording are recorded by other recording elements. And a recording control means for controlling the recording apparatus. The selection unit selects, as the combination table to be used, the combination table that includes at least one recording element that can perform normal recording as the recording element that records pixels on the same line. The recording device described. The recording apparatus according to claim 1, wherein the storage unit stores the plurality of combination tables according to the number of scans for each recording region. The selection means performs a weighting operation according to the number of recording elements that cannot perform normal recording included in the combination of recording elements that record pixels on the same line, and uses the combination according to the result of the operation. The recording apparatus according to any one of claims 1 to 3, wherein a table is selected. The selection means selects a plurality of combination tables as the combination table to be used, selects a combination table to be actually used for recording according to a predetermined rule,
2. The table changing means for changing the combination table actually used for recording to another combination table in the selected plurality of combination tables at a predetermined timing relating to execution of the recording operation. 5. The recording apparatus according to any one of items 1 to 4. The recording apparatus according to claim 5, wherein the predetermined timing is a timing related to either end of recording on a predetermined number of recording media or recording of a predetermined number of pixels. The recording apparatus according to claim 1, further comprising a detecting unit that detects the recording element that cannot normally record. The recording apparatus according to claim 1, wherein the recording head is an ink jet recording head that performs recording by discharging ink. 9. The recording head according to claim 8, wherein the recording head is a recording head that ejects ink using thermal energy, and includes a thermal energy converter for generating thermal energy applied to the ink. Recording device. A recording method for performing recording by scanning a recording head having a plurality of recording elements arranged in a predetermined direction on the recording medium in a direction intersecting the conveyance direction of the recording medium,
When performing multi-pass printing in which printing is performed by performing relative movement of the print head a plurality of times for each print area, pixels on the same line are printed by the carry amount of the print medium and the plurality of scans A table preparation step of preparing a plurality of combination tables having different combinations of recording elements;
Undischarge information acquisition step of acquiring information about a recording element that cannot perform normal recording;
In accordance with the acquired information, a selection step of selecting a combination table to be used from the plurality of combination tables;
When a combination of recording elements that record pixels on the same line includes recording elements that cannot perform normal recording, the pixels that should be recorded by the recording elements that cannot perform normal recording are recorded by other recording elements. And a recording control step of controlling the recording method. A computer program for causing a computer to execute the recording method according to claim 10. A storage medium storing the computer program according to claim 11.

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