JP2004351676A - Method and device for image recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress generation of vibration at an inkjet printer of a serial printing system. <P>SOLUTION: A first head 30 and a second head 40 are arranged separately from each other in a transfer direction of a recording paper sheet 12. The plurality of the recording heads 30 and 40 are moved in a direction to intersect the transfer direction of the recording paper sheet 12 to scan the whole width of a recording area of the recording paper sheet 12. The heads 30 and 40 are simultaneously moved in mutually opposite directions to record an image. The vibration accompanying the head movement is offset by synchronously moving the two heads 30 and 40 in the opposite directions. Since the two heads 30 and 40 are moved to scan the whole width of the recording area unlike the case of recording different recording areas by two heads, a density decrease and generation of streaks at a boundary part of the recording areas are eliminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recording method and apparatus, and more particularly to a method and apparatus for recording an image by sending a recording head in a direction crossing a recording paper conveyance direction.
[0002]
[Prior art]
In a serial recording type ink jet printer, for example, an ink jet head is scanned in a direction crossing the recording paper transport direction to record an image on the recording paper. In such a serial recording type printer, a plurality of recording heads are provided to perform high-speed recording or to increase density by overlapping recording (see, for example, Patent Documents 1 to 4). There has also been proposed a printer that uses a plurality of recording heads and independently records on a recording area (see, for example, Patent Documents 5 and 6).
[0003]
[Patent Document 1]
Japanese Patent Publication No. 56-10188 (page 2, Fig. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 55-23654 (first page, FIG. 2)
[Patent Document 3]
JP-A-63-276579 (first page, FIG. 5)
[Patent Document 4]
Japanese Patent No. 2966572 (2nd page, FIG. 1)
[Patent Document 5]
Japanese Patent No. 3029516 (second page, FIG. 2)
[Patent Document 6]
Japanese Patent No. 3032641 (2nd page, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, in the printers of Patent Documents 1 to 4, since the recording area is divided by two recording heads, streaks occur at the boundary between the recording areas between these recording heads, and the uniformity of density between different recording areas. It may be lost. On the other hand, in the printers of Patent Documents 5 and 6, since the two recording heads move the entire width of the recording area, there is no occurrence of a discontinuous portion or the like in the recording area, but the moving area of the head carriage becomes long. Since the inertia due to the movement of the head and the carriage is increased, there is a problem that the vibration of the entire casing during recording is increased. In addition, there is a problem that the recording area is displaced by the two recording heads, and there is a problem that a high-quality image cannot be recorded.
[0005]
In addition, in the ink jet recording, the fading performance due to light or ozone is inferior to that of other recording methods, and the fading of printing is a problem. Pigment inks with excellent fading performance are more resistant to fading than dyeing inks, but have a drawback that the color expression range is narrow, the saturation is low, and the glossiness is reduced when recorded on glossy paper.
[0006]
SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and provides an image recording method and apparatus that eliminates the occurrence of vibration caused by the displacement of the recording area of each recording head and the movement of each recording head, and improves the fading performance. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the image recording method of the present invention is an image recording method for recording an image on the recording paper by scanning a recording head in a direction intersecting the recording paper conveyance direction, A plurality of recording heads, and each of the plurality of recording heads can scan the entire width of the recording area of the recording paper, and at least two of the plurality of recording heads simultaneously scan in opposite directions. It is characterized by doing.
[0008]
The image recording apparatus of the present invention is an image recording apparatus that records an image on the recording paper by scanning a recording head in a direction that intersects the conveying direction of the recording paper, and is arranged apart from the conveying direction. A plurality of recording heads; scanning means for scanning each of the plurality of recording heads with the full width of the recording area of the recording paper; and at least two recording heads among the plurality of recording heads simultaneously scanning in opposite directions. And a control means.
[0009]
It is preferable that approximately half of the plurality of recording heads simultaneously scan in the same direction and the remaining heads simultaneously scan in the opposite direction to the approximately half of the heads. Preferably, the odd-numbered heads simultaneously scan in the same direction in the order of arrangement of the plurality of recording heads in the transport direction, and the even-numbered heads simultaneously scan in the direction opposite to the odd-numbered heads. .
[0010]
The plurality of recording heads are ink jet heads, and it is preferable that recording is performed with different ink color sets. In addition, it is preferable to supply the head with ink that is late in order of recording on the recording paper as ink with relatively little discoloration. More preferably, the latest ink to be recorded on the recording paper is the black pigment ink, and the other ink is supplied to the head as a dye ink.
[0011]
When recording by ejecting ink from only one of the plurality of recording heads, at least one of the plurality of recording heads that does not eject other ink is opposite to the scanning direction of the ejecting head. It is preferable to scan in the direction simultaneously. Further, it is preferable that each of the plurality of recording heads records by ejecting ink only in the same scanning direction. It is preferable that the plurality of recording heads increase the scanning speed in the scanning direction in which ink is not ejected, rather than scanning in which ink is ejected and recorded.
[0012]
It is preferable that at least two of the plurality of recording heads read the same encoder pattern to obtain a recording timing signal. Further, it is preferable that the cutter for cutting the recording paper after recording can be moved in the recording paper conveyance direction.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view schematically showing an ink jet printer embodying the present invention, and FIG. 2 is a plan view of the same. A recording paper roll 11 is loaded in the ink jet printer 10. The recording paper 12 drawn from the recording paper roll 11 by a paper supply roller (not shown) is nip conveyed by the first and second sub-scanning roller pairs 13 and 14 and the first to third conveyance roller pairs 15 to 17. Each roller pair 13-17 is comprised by the feed rollers 13a-17a and the pressing rollers 13b and 18. As shown in FIG. The feed rollers 13a and 14a of the sub-scanning roller pairs 13 and 14 are composed of rubber rollers, and reliably convey the recording paper 12. The sub-scanning roller pairs 13 and 14 are rotationally driven by the sub-scanning motor 94, and the transport roller pairs 15 to 17 are rotationally driven by the transport motor 97.
[0014]
The other feed rollers 15a to 17a are made of a resin material such as polyacetal. A star wheel is used as the pressing roller 18 of the second sub-scanning roller pair 14 and the first to third transport roller pairs 15 to 17, and the contact area with the printing screen is reduced. The star wheel has small protrusions in the circumferential direction, and contacts the recording paper through the protrusions. A guide plate 19 is disposed between each of the roller pairs 13 to 17, and the guide plate 19 guides the recording paper 12 to the next roller pair.
[0015]
A first recording unit 21 is provided between the first and second sub-scanning roller pairs 13 and 14, and a second recording unit 22 is provided between the second sub-scanning roller pair 14 and the first conveying roller pair 15. A drying unit 23 is provided from the exit of the first transport roller pair 15 to the exit of the second transport roller pair 16, and a cutter unit 24 is provided between the second and third transport roller pairs 16 and 17. A paper discharge tray 25 is provided on the recording paper exit side of the third conveying roller pair 17.
[0016]
The first recording unit 21 includes a first inkjet head (hereinafter simply referred to as a first head) 30, a carriage 31, guide shafts 32 and 33, and a main scanning mechanism 34 (see FIG. 2). The guide shafts 32 and 33 are arranged in the recording paper width direction (main scanning direction M) orthogonal to the conveyance direction (sub-scanning direction S) of the recording paper 12, and guide the carriage 31 in the main scanning direction. The first head 30 is fixed to the carriage 31, and the carriage 31 is moved along the guide shafts 32 and 33 by the main scanning mechanism 34. The second recording unit 22 is configured similarly to the first recording unit 21, and includes a second head 40, a carriage 41, guide shafts 42 and 43, and a main scanning mechanism 44.
[0017]
As shown in FIGS. 1 and 3, first and second sensors 45 and 46 are disposed on the carriages 31 and 41 of the first and second recording units 21 and 22, respectively. These sensors 45 and 46 read a stripe-shaped encoded pattern 48 of the same encoder pattern film 47. The first sensor 45 moves above the pattern film 47 and the second sensor 46 moves below the pattern film 47 so that the sensors 45 and 46 do not interfere with each other. The read signal of the encode pattern 48 by these sensors 45 and 46 is sent to the controller 50 (see FIG. 6), and the ejection timing of the heads 30 and 40 in the first and second recording units 21 and 22 is synchronized by this read signal. Is planned.
[0018]
FIG. 4 shows the initial positions of the heads 30 and 40, where the first head 30 is located on one side edge of the recording paper 12 and the second head 40 is located on the other side edge of the recording paper 12. In the first head 30, a yellow (Y) ink discharge nozzle row 51, a light magenta (LM) ink discharge nozzle row 52, and a magenta (M) ink discharge nozzle row 53 are formed in the sub-scanning direction S. These nozzle rows 51 to 53 are arranged apart from each other in the main scanning direction M, and are arranged in the order of Y, LM, M from the side closer to the recording paper 12.
[0019]
In the second head 40, a light cyan (LC) ink discharge nozzle row 54, a cyan (C) ink discharge nozzle row 55, and a black (K) ink discharge nozzle row 56 are formed in the sub-scanning direction S. These nozzle rows 54 to 56 are also arranged apart from each other in the main scanning direction M, and are arranged in the order of LC, C, K from the side closer to the recording paper 12.
[0020]
As shown in an enlarged view in FIG. 4B, each of the nozzle arrays 51 to 56 is configured by arranging nozzles 57 at a pitch half the recording resolution, and the nozzle array length (recording width) is W. It is said that. Each nozzle row 51 to 56 is supplied with corresponding ink from an ink cartridge (not shown) mounted on the carriage. The ink cartridge may be a carriage-mounted type that is mounted separately from the head, or may be an ink cartridge and a head that are integrated. Furthermore, instead of the ink cartridge, an ink tank may be provided in the main body of the ink jet printer 10, and ink may be supplied to each head via a tube.
[0021]
As shown in FIG. 1, the heads 30 and 40 are removed from the recording paper 12, and cleaning of nozzles and capping during standby are performed by a cleaning unit (not shown).
[0022]
The drying unit 23 includes heaters 60 and 61, a fan 62, and a fan casing 63. The drying unit 23 is heated to a high temperature by the heaters 60 and 61, sprayed onto the recording surface by dry air sent by the fan 62, and the heater 60. , 61 radiated heat, the recording paper 12 is dried.
[0023]
The cutter unit 24 includes a cutter unit 65, a shift mechanism 66, and a not-shown chip tray. The cutter unit 65 includes a cutter blade 65a and a cutter drive motor 96 (see FIG. 6), and cuts the recording paper 12 along a cutting line 67 extending in the width direction of the recording paper 12, as shown in FIG. To do. The cutting line 67 is set forward and backward so as to sandwich the boundary portion 69 of each recording area 68. By cutting along the cutting line 67, the boundary portion 69 of each recording area 68 is cut off to form a borderless print 70 (see FIG. 1) for each recording area 68. The borderless print 70 is discharged to the paper discharge tray 25 by the third transport roller pair 17. Reference numeral 12 a in FIG. 5 is an area nipped by the second sub-scanning roller pair 14 at the start of recording, and the leading end area 12 a is cut along a cutting line 67.
[0024]
The cutting along the cutting line 67 is performed within the main scanning time of the heads 30 and 40, that is, when the recording paper 12 is stopped. Therefore, the front and rear cuts at each boundary 69 are performed in two consecutive main scanning times. Chips including the respective boundary portions 69 fall to the chip tray. The chip tray is formed in a size that covers a cutting position that accompanies a change in the cutter position by the shift mechanism 66, and the chips are reliably stored in the tray.
[0025]
As shown in FIGS. 1 and 2, the shift mechanism 66 includes guide shafts 71 and 72, a cutter moving motor 95, a worm gear 73 and a rack 74, a moving base 75, limit sensors 76 and 77, a cutter position sensor 78, and the like. Yes. As the cutter moving motor 95 rotates, the moving table 75 is moved to an arbitrary position in the sub-scanning direction via the worm gear 73 and the rack 74. The limit sensors 76 and 77 detect the movement limit position of the moving table 75. Further, the cutter position sensor 78 detects the initial position of the movable table 75, whereby the cutter position is initially set.
[0026]
Instead of forming the chip tray with a size that covers the cutting position, the chip tray may be fixed at a position corresponding to the cutting position of the cutter unit 65, and in this case, the chip tray is attached to the cutter tray. Since it is integrated with the unit 65, the chip tray can follow even if the cutting position is changed, and the chip tray can be made smaller.
[0027]
In FIG. 6, a system controller 50 controls the operation and image processing of the entire system. An image signal from a personal computer or a memory card as a host computer is input via the input interface 80 and sent to the image processing unit 81. In the image processing unit 81, nozzle drive signals that match the ink colors for the first head 30 and the second head 40 are output to the heads 30 and 40.
[0028]
In addition to this, the system controller 50 includes main scanning drive circuits 82 and 83 for the first and second heads, an encoder signal processing circuit 84 for main scanning control, a sub-scanning driving circuit 85, a cut position control circuit 86, a sensor signal. A processing circuit 87, a cutter driving circuit 88, a conveyance roller driving circuit 89, a key input unit 90, a display 91, and the like are connected to the motors 92 to 97 and sensors 45, 46, and 76 to 78. Has been.
[0029]
Next, the operation of this embodiment will be described. As shown in FIG. 6, when a print start operation is performed via the key input unit 90 after image data is input from a personal computer or memory card via the input interface 80, first, the sub-scanning drive circuit 85 performs the operation. The sub-scanning motor 94 is driven to rotate, and the head of the recording area 78 of the recording paper 12 is sent to the first recording unit 21. Thereafter, the main scanning motors 92 and 93 rotate via the main scanning drive circuits 82 and 83 for the first and second heads, and the first head 30 moves in the direction of the arrow A1 as shown in FIG. Then, the second head 40 moves in the direction of arrow A2. During this movement, the encode pattern 48 of the encoder pattern film 47 is read by the first and second sensors 45 and 46, and the ink discharge timing of each ink discharge nozzle 57 is synchronized based on the read signal. Thereby, ink can be discharged from each nozzle 57 of the first head 30 to the recording area at an accurate discharge position.
[0030]
Each ink ejection nozzle 57 is driven and controlled by a nozzle drive signal from the image processing unit 81, whereby ink is ejected to the recording area and an image is recorded in the main scanning direction with a width of W. At this time, the second head 40 is also scanned in accordance with the movement of the first head 30, and the scanning is performed in the opposite directions, so that the vibration of the entire casing is canceled and adverse effects such as vibration are externally caused. No effect.
[0031]
When the recording for one main scan is completed, the first and second heads 30 and 40 are returned to the initial positions at high speed as indicated by arrows B1 and B2. Further, during this head return, the recording paper 12 is fed by W / 2 and sub-scanned. Next, the remaining half of the pixels in the first row and the next half of the pixels in the second row are recorded by the first head 30. At this time, the other second head 40 is also sent in the opposite direction in synchronization with the feed of the first head 30, and the vibration of the entire casing is cancelled. During the main scanning of the second head 40, since the recording area has not yet reached the second head 40, ink ejection is not performed.
[0032]
Thereafter, pixel recording (main scanning) and W / 2 feeding (sub-scanning) of the recording paper in the latter half of each row and the first half of the next row are performed, and the half row is recorded by two main scans. The image is completed. FIG. 7 shows an example of this recording. In this embodiment, the nozzles of each nozzle row are formed at half the pitch of the recording resolution, and only the pixels corresponding to W / 2 are recorded in the first row, and similarly the pixels corresponding to W / 2 in the last row. Only record. In other words, in the first main scan, W / 2, which is half of one line, is recorded in the recording area by using the half of the recording paper feed downstream side of each nozzle row. In the next second main scan, all the nozzles in each nozzle row are used to shift the image data by half a line, and the remaining half of the first half of the first line and the latter half of the first line. Record half of that. Next, similarly in the third main scan, the remaining half of the second half of the first row and the half of the first half of the next second row are recorded. Thereafter, each row is recorded one after another. In the final scan of the last row, the remaining half of the latter half of the last row is recorded, and the recording for one image is completed.
[0033]
When the leading end of the recording area reaches the second head 40, recording is performed for each color of LC, C, and K by the second head 40 in the same manner as the first head 30. At this time, since the first and second heads 30 and 40 are synchronized so as to scan and move in directions opposite to each other, generation of vibration of the entire housing is suppressed. When the recording of the recording area by the first head 30 is completed and there is no image to be printed next, only the main scanning movement of the first head 30 is performed in synchronization with the second head 40. Ink is not discharged.
[0034]
In the first head 30, ink is ejected onto the recording paper 12 in the order of Y, LM, and M by the nozzle rows 51 to 53, and in the second head 40, recording is performed in the order of LC, C, and K by the nozzle rows 54 to 56. Ink is ejected onto the paper 12. Thereby, K, C, and LC with less fading are recorded at the end, so that an image with less fading can be recorded. In particular, if the order of the strong ink to the weak ink is K, C, LC, M, LM, Y, an image with the least faded color can be obtained. In this embodiment, since the K ink is a pigment ink with a little amber color and the other inks are dye inks, the K ink that is recorded last is the strongest amber color ink. Fewer images can be obtained. Moreover, since only K is a pigment ink and the other colors are dye inks, a high-quality image can be obtained without narrowing the color expression range or lowering the saturation, unlike the pigment ink. .
[0035]
The full color image in which each color of Y, LM, M, LC, C, and K is recorded by the first and second recording units 21 and 22 is sent to the drying unit 23 to dry each color ink. The recording paper 12 that has been dried is sent to the cutter unit 24.
[0036]
The cutter unit 24 detects the boundary portion 69 of each image based on the number of sub-scan feeds, operates the cutter unit 65 at this position, separates each image into a print 70, and discharges it to the discharge tray 25. Make paper. The timing at which the leading end of the recording paper 12 enters the position control range of the cutter unit 24 is the value obtained by dividing the distance from the recording start position of the second head 40 by the sub-scan feed distance: W / 2. Calculated by scanning. Therefore, the recording paper 12 can be separated at the boundary 69 of the adjacent recording area 68 as shown in FIG. 5 by controlling the position by driving the distance corresponding to the fraction of the calculation result by the cutter moving motor 95. The remaining unrecorded recording paper front end is returned to the exit position of the second sub-scanning roller pair 14 and enters a standby state.
[0037]
In the above-described embodiment, the unidirectional recording method is adopted so that the recording order of each ink is always constant, but a reciprocating recording method may be used instead. In this case, although the recording time is shortened by the reciprocal recording, the image quality deteriorates due to the variation based on the reciprocal asymmetry. Further, in recording by the second head 40, half of the pixels in each row are recorded with K, which is strong against fading, at the end, but the remaining half of the pixels are in the order of K, C, and LC, causing color unevenness. In addition, since the ink that is resistant to fading is not always the last recording, the fading characteristics are slightly deteriorated as compared with the one-way recording method. However, since Y, LM, M, etc. that are weak to fading are recorded first by the first head 30, the fading characteristics as a whole are not deteriorated as compared with the conventional one-head type.
[0038]
The test method of strong / weak amber color is generally performed by an accelerated exposure method using xenon light or a fluorescent lamp, or an exposure test in an ozone atmosphere from an ozone generator. Since the surface of the ink receiving layer of the recording paper 12 has a stronger intensity of light and ozone, it can be easily faded by relatively later recording an ink with less fading (strong against fading) due to light or ozone ( Due to the effect of covering the surface of the ink (which is weak to fading), an image with less fading is obtained as a whole.
[0039]
In the above embodiment, the two ink jet heads 30 and 40 are used. However, the number of heads used is not limited to this, and may be three or more. Preferably, even numbers are used, and two of these are used as one set, and recording is performed by changing the scanning direction in synchronization to suppress the occurrence of vibration due to head movement. In the case of an odd number, the recording is performed by moving the heads in different directions synchronously as a set of two, but the vibration reduction rate is reduced compared to the case of an even number, but the occurrence of vibration is similarly suppressed. It is done.
[0040]
FIG. 8 shows a main part of a printer using the first to fourth heads 101 to 104. FIG. 8 shows the initial positions of the heads 101 to 104. The first and third heads 101 and 103 are located on one side edge of the recording paper 12, and the second and fourth heads 102 and 104 are recording paper. 12 on the other side edge. In the first head 101, a Y ink discharge nozzle row 111 and a red (R) ink discharge nozzle row 112 are formed in the sub-scanning direction S. These nozzle arrays 111 and 112 are arranged apart from each other in the main scanning direction M, and are arranged in the order of Y and R from the side closer to the recording paper 12.
[0041]
Further, the LM ink ejection nozzle row 113 and the M ink ejection nozzle row 114 are formed in the second head 102 in the same manner, and the LM and M are arranged in order from the side closer to the recording paper 12. The third head 103 is formed with an LC ink discharge nozzle row 115 and a C ink discharge nozzle row 116 in order from the side closer to the recording paper 12, and the fourth head 104 has the first order from the side closer to the recording paper 12. The 1 black (K1) ink discharge nozzle row 117 and the second black (K2) ink discharge nozzle row 118 are formed so as to be shifted by one pixel. Each nozzle in each of the nozzle rows 111 to 118 is formed at a pitch that is half of the recording resolution, and one line is printed for the width of W by two main scans.
[0042]
As in the above embodiment, the encode patterns are read from the first encoder pattern film 123 by the sensors 121 and 122 of the first and second heads 101 and 102, and the third and fourth heads 103 and 104 are read. The encode pattern is read from the second encoder pattern film 126 by the sensors 124 and 125, and the ink ejection timing is synchronized.
[0043]
The recording mode in the second embodiment includes a first recording mode for recording with six colors K1, C, LC, M, LM, and Y, a second recording mode for recording with two colors K1, R, and K1, There is a third recording mode for recording with a single color of K2, which can be selected.
[0044]
In the first recording mode, the first to fourth heads 101 to 104 are used, and the odd-numbered and even-numbered two pieces are reversed in the main scanning direction. Further, the sub-scan is performed every W / 2. Here, the order of the ink that is resistant to the amber color is the order of K, C, LC, M, LM, R, and Y, and the ink layer that is resistant to the amber color becomes the upper layer by recording from the order that is weak to the amber color. As a result, it is possible to obtain a print resistant to amber. Further, when the first and third heads 101 and 103 move in the A1 direction, the second and fourth heads 102 and 104 move in the A2 direction opposite to A1, so that the occurrence of vibration is suppressed.
[0045]
In the second recording mode, the R ink ejection nozzle row 112 of the first head 101 and the K1 ink ejection nozzle row 117 of the fourth head 104 are used to perform main scanning of these heads 101 and 104 in opposite directions. Further, the sub-scan is performed every W / 2. Also in this case, vibration generated by the main scanning of the heads 101 and 104 can be suppressed.
[0046]
In the third recording mode, ink is ejected from the nozzle rows 117 and 118 of K1 and K2 that are shifted by one pixel in one main scan of the fourth head 104. Therefore, the first and second recording modes described above are used. Thus, thinning recording is not performed, and sub-scanning is performed W by W. In synchronization with the main scanning of the fourth head 104, the third head 103 is main-scanned in the reverse direction, and no ink is ejected by the third head 103. In the third recording mode, since the third and fourth heads 103 and 104 are main-scanned in different directions, the occurrence of vibration is suppressed.
[0047]
The arrangement and pitch of the ink discharge nozzle rows in each head are not limited to those in the above embodiments, and may be changed as appropriate. In the above embodiment, an ink jet recording type printer has been described as an example. However, the present invention is implemented by another recording method, for example, another serial type printer having a thermal head, a dot impact head, an exposure head, and the like. In this case as well, the occurrence of vibration of each head can be suppressed.
[0048]
【The invention's effect】
According to the present invention, a plurality of recording heads are arranged in the transport direction, and at least two of the plurality of recording heads are simultaneously scanned in opposite directions. Vibration can be canceled and generation of vibration can be suppressed. In addition, since each of the plurality of recording heads can scan the entire width of the recording area of the recording paper, streaks occur at the boundary of the recording area between the recording heads, and the uniformity of the density at the boundary of the recording area is lost. It will not be broken.
[0049]
Since at least two heads of the plurality of recording heads read the same encoder pattern to obtain a recording timing signal, the positional deviation of the recording area by the two recording heads can be eliminated, and a high-quality image can be obtained. Recording is possible.
[0050]
The plurality of recording heads are ink-jet heads, each of which performs recording with a different ink color set, and supplies the head with a relatively low-colored ink that is recorded in the order of recording in the recording paper. It is possible to easily create prints that are resistant to damage. Similarly, by using the black ink of the pigment ink as the slowest ink to be recorded on the recording paper and the dye ink as the other ink, it is possible to easily create a print more resistant to fading.
[0051]
Further, when recording is performed by ejecting ink from only one of the plurality of recording heads, at least one of the plurality of recording heads that does not eject other ink is opposite to the scanning direction of the ejecting head. By simultaneously scanning in this direction, the occurrence of vibration can be suppressed even when recording is performed with one recording head.
[0052]
Each of the plurality of recording heads discharges and records ink only in the same scanning direction, so that the recording is surely performed in order of weakness against fading and a print more resistant to fading is obtained. Further, by increasing the scanning speed in the scanning direction in which the plurality of recording heads do not eject ink rather than scanning in which ink is recorded, the printing speed can be increased and the entire printing time can be shortened. Further, by enabling the cutter for cutting the recording paper after recording to be moved in the recording paper conveyance direction, the recording paper can be cut at an arbitrary position.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an ink jet printer embodying the present invention.
FIG. 2 is a plan view of the same.
FIG. 3 is a perspective view showing an encoder pattern film and each sensor for synchronizing the first and second heads.
FIG. 4A is a schematic plan view for explaining the main scanning operation of the first and second heads, and FIG. 4B is an enlarged plan view showing a part of the nozzle row.
FIG. 5 is a plan view showing an example of recording areas and cutting lines recorded on recording paper.
FIG. 6 is a control block diagram of the ink jet printer.
FIGS. 7A and 7B are explanatory diagrams sequentially showing recording states by main scanning. FIGS.
FIG. 8 is a plan view showing a main part of another embodiment having first to fourth ink jet heads.
[Explanation of symbols]
10 Inkjet printer
12 Recording paper
13, 14 Sub-scanning roller pair
15-17 Conveyor roller pair
21 First recording section
22 Second recording section
23 Drying section
24 Cutter part
30 First head
40 2nd head
45,46 sensor
47 Pattern film for encoder
48 Encoding pattern
51,111 Yellow (Y) ink discharge nozzle row
52,113 Light magenta (LM) discharge nozzle row
53,114 Magenta (M) ink ejection nozzle array
54,115 Light cyan (LC) ink ejection nozzle array
55,116 Cyan (C) discharge nozzle row
56 Black (K) ink discharge nozzle row
57 nozzles
101-104 1st-4th head
112 Red (R) discharge nozzle row
117 First black (K1) ink discharge nozzle row
118 Second black (K2) ink discharge nozzle row

Claims (22)

In an image recording method for recording an image on the recording paper by scanning the recording head in a direction crossing the conveyance direction of the recording paper,
A plurality of recording heads are arranged in the transport direction,
Each of the plurality of recording heads can scan the entire width of the recording area of the recording paper,
An image recording method, wherein at least two of the plurality of recording heads simultaneously scan in opposite directions. 2. The image recording method according to claim 1, wherein approximately half of the plurality of recording heads simultaneously scan in the same direction, and the remaining heads simultaneously scan in a direction opposite to the approximately half of the heads. . The odd-numbered heads simultaneously scan in the same direction in the arrangement order of the plurality of recording heads in the transport direction, and the even-numbered heads simultaneously scan in the direction opposite to the odd-numbered heads. The image recording method according to claim 1 or 2. The image recording method according to claim 1, wherein the plurality of recording heads are ink jet heads, and each of the recording heads performs recording with different ink color sets. The image recording method according to claim 4, wherein ink with a slow order of recording on the recording paper is supplied to the head as ink with relatively little discoloration. 6. The image recording method according to claim 4, wherein the ink with the latest order of recording on the recording paper is supplied to the head as black ink of pigment ink and the other ink as dye ink. When recording by ejecting ink from only one of the plurality of recording heads, at least one of the plurality of recording heads that does not eject other ink is opposite to the scanning direction of the ejecting head. 7. The image recording method according to claim 4, wherein scanning is simultaneously performed in the direction. 8. The image recording method according to claim 4, wherein each of the plurality of recording heads records by ejecting ink only in the same scanning direction. The image recording method according to claim 8, wherein the plurality of recording heads increase a scanning speed in a scanning direction in which ink is not ejected, compared to scanning in which ink is ejected and recorded. 10. The image recording method according to claim 1, wherein at least two of the plurality of recording heads read the same encoder pattern to obtain a recording timing signal. 11. The image recording method according to claim 1, wherein a cutter for cutting the recording paper after recording is movable in the recording paper conveyance direction. In an image recording apparatus for recording an image on the recording paper by scanning the recording head in a direction crossing the conveyance direction of the recording paper,
A plurality of recording heads arranged apart in the transport direction;
Scanning means for scanning each of the plurality of recording heads with the full width of the recording area of the recording paper;
An image recording apparatus comprising: a control unit that simultaneously scans at least two of the plurality of recording heads in opposite directions. 13. The control unit scans substantially half of the plurality of recording heads simultaneously in the same direction and simultaneously scans the remaining heads in a direction opposite to the half of the heads. The image recording apparatus described. The control means simultaneously scans odd-numbered heads in the same direction in the order of arrangement of the plurality of recording heads in the transport direction, and simultaneously scans even-numbered heads in a direction opposite to the odd-numbered heads. The image recording apparatus according to claim 12 or 13, 15. The image recording apparatus according to claim 12, wherein the plurality of recording heads are ink jet heads, and each performs recording with different ink color sets. The image recording apparatus according to claim 15, wherein ink with a low order of recording on the recording paper is supplied to the head as ink with relatively little discoloration. The image recording apparatus according to claim 15 or 16, wherein the ink with the latest order of recording on the recording paper is supplied to the head as black ink of pigment ink and the other ink as dye ink. The control means scans the head that discharges at least one of the plurality of recording heads that does not discharge other ink when recording by discharging ink from only one of the plurality of recording heads. 18. The image recording apparatus according to claim 15, wherein scanning is simultaneously performed in a direction opposite to the direction. 19. The image recording apparatus according to claim 15, wherein each of the plurality of recording heads records by discharging ink only in the same scanning direction. The image recording apparatus according to claim 19, wherein the control unit increases a scanning speed at the time of scanning without ejecting ink, compared with scanning at which ink is ejected and recorded. The control means performs a recording timing signal in at least one set of heads that simultaneously scans by changing a scanning direction among the plurality of recording heads based on a reading signal of the same encoder pattern. The image recording apparatus according to any one of 12 to 20. The image recording apparatus according to any one of claims 12 to 21, further comprising: a cutter that cuts the recording paper after recording in the scanning direction; and a moving unit that moves the cutter in the recording paper conveyance direction.

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