JP2020196219A - Ink jet recording apparatus and ink jet recording method - Google Patents

Abstract

To output an image of high image quality by hindering deterioration of image quality, resulting from contact with a conveyance mechanism, in a configuration in which multi-pass recording is carried out with an ink jet recording apparatus of full-line type.SOLUTION: An image in a unit area is completed by a plurality of processes of recording conveyance by alternately performing recording conveyance in which a conveyance mechanism 7 is caused to convey a recording medium P in a normal direction while a recording head 2 is caused to emit ink and recording conveyance in which it is caused to convey the recording medium in a reverse direction. One recording mode is set from among a plurality of recording modes including a first recording mode in which the length of the unit area in a conveying direction is a first length and a second recording mode in which it is a second length shorter than the first length. In the first recording mode, nip conveyance in which the unit area is conveyed while being nipped by the conveyance mechanism 7 is interposed between the plurality of processes of recording conveyance for completing the image of the unit area. In a second recording mode, the nip conveyance is not interposed between the plurality of processes of recording conveyance for completing the image of the unit area.SELECTED DRAWING: Figure 6

Description

The present invention relates to an inkjet recording device and an inkjet recording method.

In Patent Document 1, a step of transporting a recording medium in the forward direction and a step of transporting the recording medium in the opposite direction to the forward direction while ejecting ink from a line-type inkjet recording head are repeated to form a recording medium. A multi-pass recording method for recording an image is disclosed. According to such a multipath recording method, ink is gradually applied to a unit area of a recording medium by a plurality of recording transports, so that a large amount of ink is applied in a short time, resulting in a bleeding phenomenon. Can be suppressed. Further, by moving the inkjet recording head by several pixels in the nozzle arrangement direction between the recording transfer and the recording transfer, the pixel array extending in the transfer direction is recorded by a plurality of nozzles, and the ejection characteristics of the individual nozzles are recorded. It is possible to alleviate streaks and unevenness caused by.

Japanese Patent No. 4715209

However, Patent Document 1 does not describe the positional relationship between the transport mechanism for transporting the recording medium and the recording head in the transport direction. Therefore, when the multipath recording described in Patent Document 1 is performed, a situation may occur in which a region to which ink is applied but the image is not completed is conveyed while being nipated by the conveying mechanism. In this case, depending on the state of the recording medium, the surface thereof may be deformed, causing uneven transport marks in the image and deteriorating the image quality.

The present invention has been made to solve the above problems. Therefore, the purpose is to output a high-quality image while suppressing deterioration of image quality due to contact with the transport mechanism in a configuration in which multipath recording is performed by a full-line type inkjet recording device.

Therefore, in the present invention, the recording head in which the nozzles for ejecting ink are arranged is provided at a position upstream of the recording head in the transport direction intersecting the direction of the arrangement, and the recording is performed while niping the recording medium. A transport mechanism capable of transporting the medium in the forward direction in the transport direction and the opposite direction opposite to the forward direction, and the transport mechanism transports the recording medium in the forward direction while ejecting ink to the recording head. The recording having a predetermined length in the transport direction is performed by alternately performing the recording transport for causing the recording and the recording transport for transporting the recording medium to the transport mechanism in the opposite direction while ejecting ink to the recording head. From the control means for completing the image of the unit region on the medium by the plurality of recording transports, the first recording mode in which the length of the unit region in the transport direction is the first length, and the first length. The first recording mode is an inkjet recording apparatus including a second recording mode having a small second length and a setting means for setting one recording mode from a plurality of recording modes including the first recording mode. The second recording mode includes nip transport in which the unit region is niped to the transport mechanism during the plurality of recording transports for completing an image of the unit region. It is characterized in that the nip transfer is not included between the plurality of record transfer for completing the image.

According to the present invention, in a configuration in which multipath recording is performed by a full-line type inkjet recording device, it is possible to suppress deterioration of image quality due to contact with a transport mechanism and output a high-quality image.

It is sectional drawing of the main part of the inkjet recording apparatus. It is a figure for demonstrating the structure of a recording head. It is a block diagram which shows the control structure of a recording apparatus. It is a schematic diagram for demonstrating multipath recording. It is a schematic diagram for demonstrating multipath recording. It is a figure for demonstrating two recording modes. It is a figure which shows the correspondence relationship between a recording medium and a recording mode. It is a figure which shows another example of the correspondence relationship between a recording medium and a recording mode. It is a figure which shows the correspondence relationship of the ink application amount and a recording mode. It is a figure which shows the example of a batch transfer. It is a figure which shows the example of the correspondence relation between various conditions and a recording mode.

(First Embodiment)
1 (a) and 1 (b) are schematic cross-sectional views of a main part of an inkjet recording device (hereinafter, also referred to as “recording device”) 1 that can be used in the present embodiment. FIG. 1A shows a state in which the recording head 2 is performing a recording operation, and FIG. 1B shows a state in which the recording head 2 is performing a maintenance operation. In the drawings below, the x direction is the transport direction for transporting the recording medium from the feeding section to the discharging section, the y direction intersecting the x direction is the width direction of the recording medium, and the z direction is the vertical direction (opposite the gravity direction). Direction).

The recording medium P of the present embodiment is held as a roll 3 in a state of being wound around a roll shaft 11 as a feeding unit. The roll shaft 11 is held by the roll holder 8 and can be rotated in the R1 direction and the R2 direction in the figure by the transport drive unit 10. The transport roller pair 7 composed of the driving roller and the driven roller nips the recording medium P fed from the roll 3 from the front and back surfaces and rotates the recording medium P in the forward direction (C1 direction or C2 direction in the figure). It is conveyed in the + x direction) or in the opposite direction (−x direction) to the forward direction. The surface of the transport roller pair 7 can be made of a rubber material, a foam material, or the like. The driven roller may be changed to spur. That is, the forward direction is the direction from the feeding section to the discharging section, and the reverse direction is the direction from the discharging section to the feeding section.

The recording head 2 ejects ink according to the recording data and records an image on the recording medium P being conveyed. The ink discharged by the recording head 2 is supplied to the recording head 2 from an ink tank arranged inside the apparatus via a tube (not shown). The platen 12 maintains the smoothness of the recording medium P while supporting the recording medium P recorded by the recording head 2 from the back surface.

The head holder 5 that holds the recording head 2 can be moved in the z direction and the y direction along the elevating shaft 13 by a driving means (not shown). When performing the recording operation, the head holder 5 moves to a position where the nozzle surface of the recording head 2 and the recording medium P face each other at an appropriate distance (see FIG. 1A). When performing a maintenance operation on the recording head 2, the head holder 5 moves to a position where the nozzle surface of the recording head 2 and the maintenance unit 6 described later face each other at an appropriate distance (see FIG. 1B).

In the recording operation shown in FIG. 1A, the recording medium P is conveyed by the transfer drive unit 10 and the transfer roller pair 7. When the transfer drive unit 10 rotates the roll 3 in the R1 direction in the figure and the transfer roller pair 7 rotates in the C1 direction in the figure, a new region of the recording medium P is separated from the roll 3 and sandwiched between the transfer roller pairs 7. While being transported in the + x direction. Hereinafter, such transport is referred to as forward transport. On the other hand, when the transport drive unit 10 rotates the roll 3 in the R2 direction in the figure and the transport roller pair 7 rotates in the C2 direction in the figure, the recording medium P sandwiched between the transport roller pairs 7 is -x in the opposite direction. A part of the recording medium P which is conveyed in the direction and separated is wound around the roll 3 again. Hereinafter, such transfer will be referred to as reverse transfer. A back tension in the −x direction is applied to the recording medium P between the transfer roller pair 7 and the transfer drive unit 10 by the torque limiter of the transfer drive unit 10.

Although not shown in the figure, a cutter unit for cutting the recording medium for which recording has been completed and a cutter unit are cut at a position further downstream of the recording head 2 in the substantially transport direction of the recording medium P. A basket is provided as a discharge unit for accommodating the recording medium. That is, the recording medium P is conveyed from the roll 3 as the feeding unit to the basket as the discharging unit. Further, in FIGS. 1A and 1B, the recording medium P is described in the form of being held as the roll 3, but the recording medium P may be cut paper. That is, the cut paper loaded on the cassette or the like may be fed by a feeding roller or the like.

When performing maintenance processing on the recording head 2, the head holder 5 is vertically above the recording operation, and the nozzle surface of the recording head 2 faces the maintenance unit 6 in the z direction and the y direction. (See FIG. 1 (b)). The maintenance unit 6 of the present embodiment has a wiper blade 43 for wiping the nozzle surface of the recording head 2 and a wiper holder 44 for supporting the wiper blade 43. By moving the wiper holder 44 in the y direction with the tip of the wiper blade 43 in contact with the nozzle surface of the recording head 2, excess ink and dust adhering to the nozzle surface can be removed.

2A to 2D are diagrams for explaining the configuration of the recording head 2. FIG. 2A is a side view of the recording head 2, and here shows a state in which a maintenance operation is performed on the recording head. The recording head 2 of the present embodiment is a full-line type inkjet recording head in which nozzles for ejecting ink are arranged in the y direction by a distance corresponding to the maximum width of the recording medium P.

The wiper holder 44 is connected to a part of the drive belt 46, and moves in the ± y direction in the figure while being guided by the shaft 45 as the drive shaft 47 rotates. By moving the wiper blade 43 in the ± y direction in the figure while abutting on the nozzle surface of the recording head 2, the nozzle row extending in the y direction is wiped.

2 (b) to 2 (d) are diagrams showing an example of arrangement of nozzle rows in the recording head 2. Each figure is a view seen from the nozzle surface side. FIG. 2B shows an example in which one long chip 41 is arranged on one long base substrate 40. On the long chip 41, nozzle rows 42 formed by arranging nozzles for ejecting ink of the same color in a row over a distance corresponding to the maximum width of the recording medium P are arranged in parallel for four rows. Each of the four nozzle rows ejects black, cyan, magenta, and yellow inks.

FIG. 2C shows an example in which a plurality of short chips 41 are arranged on one long base substrate 40 while being alternately displaced in the x direction. FIG. 2D shows an example in which a plurality of short base substrates 40 on which short chips 41 are arranged are arranged on one support substrate 48 while being alternately displaced in the x direction. In each of the examples, nozzle rows for four colors are formed in parallel on each chip 41, and the nozzles of each color are arranged without interruption in the y direction over a distance corresponding to the width of the recording medium P.

Each chip 41 is provided with an ejection element that generates energy for ejecting ink so as to correspond to each nozzle. As the discharge element, an electric heat conversion element (heater), a piezo element, an electrostatic element, a MEMS element, or the like can be adopted.

FIG. 3 is a block diagram showing a control configuration of the recording device 1. The CPU 501 controls the entire device while using the RAM 503 as a work area according to the programs and parameters stored in the ROM 502. The image data created by the host device 100 connected to the outside is input to the recording device 1 via the interface I / F 504, and is developed in the RAM 503 under the instruction of the CPU 501. Under the instruction of the CPU 501, the image processing unit 505 performs predetermined image processing on the image data expanded in the RAM 503, and generates the recording data that can be recorded by the recording head 2.

The head driver 506 drives the recording head 2 according to the generated recording data under the instruction of the CPU 501 to eject ink. During the ejection operation by the recording head 2, the transfer unit 9 performs the transfer operation of the recording medium P. Here, the transport unit 9 includes the transport drive unit 10 and the transport roller pair 7 as described with reference to FIG. 1, and transports the recording medium P according to the transport amount and the transport direction indicated by the CPU 501. The head holder drive unit 507 moves the head holder 5 in the z direction and the y direction in accordance with the instruction of the CPU 501 prior to the recording operation and the maintenance operation.

4 and 5 are schematic views for explaining an example of multipath recording that can be executed by the recording device 1 of the present embodiment. In multipath recording, the recording medium is conveyed in the forward and reverse directions so that the recording head 2 moves relative to the unit area on the recording medium in the forward and reverse directions, and the image of the unit area is displayed. It is completed step by step by multiple relative movements accompanied by the ejection operation of the recording head. Hereinafter, the transfer operation of the recording medium accompanied by the ejection operation of the recording head is referred to as recording transfer. Further, the transfer operation of the recording medium without the discharge operation of the recording head is referred to as empty transfer.

FIG. 4 schematically shows the plurality of recording transports in a form in which the recording medium P is fixed, that is, in a form in which the recording head moves with respect to a unit area. On the other hand, FIG. 5 shows the plurality of recording transports in a form in which the recording head 2 is fixed, that is, in a form in which the recording medium P is moved with respect to the recording head 2. Therefore, between FIGS. 4 and 5, the forward direction and the reverse direction are reversed. In both figures, multi-pass recording in which an image is completed by eight recording transfers for a unit region having a length L in the conveying direction is shown for 18 recording transfers (passes).

In the case of 8-pass multi-pass recording, in each unit area, the forward recording transfer in which ink is applied while being conveyed in the forward direction and the reverse recording transfer in which ink is applied while being conveyed in the reverse direction are performed four times each. The images are completed alternately.

In the figure, the first eight recording transports (passes) are recording transports peculiar to the tip where the transport amount is gradually increased, and the recording transports after the ninth pass are a positive recording transport with a distance of 5 L and a distance of 4 L. Reverse recording transport is repeated. In both figures, the black arrow indicates a recording transfer in which ink is ejected to the corresponding unit area, and the white arrow indicates an empty transfer in which ink is not ejected to the corresponding unit area.

In FIG. 4, the unit area shown by the blank area indicates a unit area in which recording has not been started. Further, the unit area indicated by dots indicates the unit area in the middle of recording, and the unit area filled with gray indicates the unit area in which recording is completed. On the other hand, in FIG. 5, the numbers shown in each unit area indicate how many times each unit area has been recorded and conveyed in each path.

Here, attention is paid to the first unit region of length L located on the most advanced side of the recording medium P. The first unit area includes forward recording transport at distance L, reverse recording transport at distance L, forward recording transport at distance 2L, reverse recording transport at distance 2L, forward recording transport at distance 3L, reverse recording transport at distance 3L, and reverse recording transport at distance 4L. The image is completed by eight recording transports of the forward recording transport and the reverse recording transport at a distance of 4 L. The second unit area adjacent to the first unit area is a forward recording transport of a distance of 2L, a reverse recording transport of a distance of 2L, a forward recording transport of a distance of 3L, a reverse recording transport of a distance of 3L, a forward recording transport of a distance of 4L, and a distance of 4L. The image is completed by the reverse recording transfer, the forward recording transfer at a distance of 5 L, and the reverse recording transfer at a distance of 5 L.

In such multi-pass recording, ink is applied to each unit area in eight times, so that the bleeding phenomenon can be suppressed even when a high-density image is recorded in the unit area. .. Further, by interposing an operation of moving the recording head 2 in the y direction between each recording transfer, it is possible to avoid a state in which dots recorded by individual nozzles are lined up in a line in the transfer direction, which is caused by the ejection characteristics of the nozzles. It is possible to alleviate streaks and unevenness.

6 (a) and 6 (b) are diagrams for explaining the 5-pass multipath recording performed by the recording device of the present embodiment. In 5-pass multi-pass recording, recording is carried out 5 times for each unit area. Further, assuming that the unit region length is L, the maximum transport amount in the forward direction is 3 L, and the maximum transport amount in the reverse direction is 2 L. In the case of odd-numbered multipath recording, empty transport as described with reference to FIGS. 4 and 5 does not occur. In the figure, the distance D indicates the distance from the nozzle row 42 (that is, the position where ink is applied) on the most upstream side of the recording head 2 to the nip portion NP of the transfer roller pair 7. In this embodiment, D = 65 mm.

FIG. 6A shows the recording states of the 1st to 9th passes in the 5-pass multipath recording in which the length L1 of the unit region satisfies D ≦ 2 × L1. In this embodiment, L1 = 60 mm. In the case of FIG. 6A, in all the unit areas except the first unit area (first unit area), there is a situation in which the ink is once applied and then passes through the nip portion NP of the transport roller pair 7. .. Hereinafter, the transfer performed while being nipated by the transfer roller pair 7 during the recording of the multipath recording is referred to as a nip transfer.

For example, in the figure, the second unit area is nip-conveyed in the fourth and fifth passes, and the third unit area is nip-conveyed in the sixth and seventh passes. As described above, in the 5-pass multipath recording in which the unit area width L1 satisfies L1 <D ≦ 2 × L1, one reciprocating (twice) nip transfer is interposed in all the unit areas other than the first unit area. It will be. A certain amount of ink has already been applied to the unit area after at least one recording transfer, and the surface of the recording medium is moist. Therefore, if the nip is conveyed in that state, the surface may be deformed, resulting in unevenness and recognition. Hereinafter, in the present specification, the image harmful effect caused by the intervention of such nip transfer is referred to as transfer trace unevenness.

On the other hand, FIG. 6B is a diagram showing the case where multi-pass recording of 5 passes is performed in a state where the length L2 of the unit region satisfies D> 2 × L2, from the 1st to the 9th passes. .. In this embodiment, L2 = 30 mm. In the case of FIG. 6B, the maximum transport amount in the reverse direction, that is, twice the length of the unit region length L2, is smaller than the distance D from the nozzle row 42 to the nip portion NP, and the images of all the unit regions are displayed. It is completed without the intervention of nip transfer. That is, in the case of FIG. 6B, the above-mentioned uneven transport trace does not occur. However, in FIG. 6B, the throughput is lower than that in FIG. 6A because the unit area length L2 is reduced.

By the way, the degree of conspicuousness of the transport trace unevenness described with reference to FIG. 6A differs depending on the type of recording medium and the like. For example, in a glossy paper or film-based recording medium having a relatively smooth surface, deformation due to nip transfer is large, and uneven transfer marks tend to be conspicuous. On the other hand, in plain paper or coated paper having relatively large irregularities formed on the surface, the deformation due to nip transfer is small, and the unevenness of the transfer trace tends to be inconspicuous.

In view of the above, in the present embodiment, a mode A in which the nip transfer is interposed as shown in FIG. 6A and a mode B in which the nip transfer is not interposed as shown in FIG. 6B are prepared. .. Then, the CPU 501 sets an appropriate recording mode according to the type of the recording medium.

FIG. 7 is a diagram showing a correspondence relationship between the type of recording medium and the recording mode. The type of the recording medium may be specified by the user, for example, via the operation panel of the recording device or the printer driver installed in the host device 100, or may be detected by a sensor arranged in the recording device 1. In any case, the CPU 501 sets either mode A or mode B based on the type of recording medium specified. Then, in the case of mode A, after setting the length of the unit region to L1 = 60 mm, multipath recording of 5 passes is performed according to the recording method shown in FIG. 6A. Further, in the case of mode B, the length of the unit region is set to L2 = 30 mm, and 5-pass multipath recording is performed according to the recording method shown in FIG. 6 (b).

As shown in FIG. 7, in the present embodiment, mode A in which nip transfer is interposed is set for plain paper and coated paper. In plain paper and coated paper, even if nip transfer is performed in a state where ink is absorbed, the surface shape does not change much and uneven transfer marks tend to be inconspicuous. Therefore, when the recording medium is plain paper or coated paper, high-speed output is prioritized over reduction of transport trace unevenness, and mode A is set.

On the other hand, for glossy paper, semi-glossy paper, art paper, and film, mode B in which nip transfer is not interposed is set. The surfaces of glossy paper, semi-glossy paper, and film are smooth, but they swell or soften by absorbing ink, making them susceptible to external forces. That is, the region where the nip transport is performed is deformed and the transport trace unevenness becomes conspicuous. Further, the art paper is relatively thick and has large irregularities on the surface, but when the nip is conveyed in a state where the ink is absorbed, the irregularities are deformed by the pressure contact of the nip portion, and the unevenness of the conveying trace becomes conspicuous. Therefore, when the recording medium is glossy paper, semi-glossy paper, art paper, or film, the mode B is set in which the reduction of transport trace unevenness is prioritized over the high-speed output and the nip transport is not interposed.

As described above, according to the present embodiment, in the full-line type inkjet recording apparatus, a recording mode in which an image is output while a long transfer distance is provided and a nip transfer is provided, and a recording mode in which a transfer distance is short and no nip transfer is provided are provided. Prepare a recording mode for recording images in. Then, by appropriately selecting and setting these recording modes according to the type of the recording medium, it is possible to output a high-quality image regardless of the type of the recording medium.

(Modified example of the first embodiment)
In the above, the recording mode is set according to the type of the recording medium, that is, the material of the recording medium, but the conspicuousness of the transport trace unevenness changes according to various factors other than the material of the recording medium. 8 (a) to 8 (c) are diagrams showing another example of the correspondence between the recording medium and the recording mode. The conspicuousness of the transport trace unevenness may depend on, for example, the degree of unevenness on the surface of the recording medium, that is, the surface roughness. This is because, in a recording medium having a large surface roughness, ink easily enters the concave and convex recesses, so that even if the transport mechanism presses against the surface, the effect on the region where the ink permeates is small, and uneven transport traces are unlikely to appear. That is, the above-mentioned recording mode may be set in association with the surface roughness.

FIG. 8A shows a case where the recording mode is set according to the surface roughness. The surface roughness can be measured by various methods, but FIG. 8 (a) shows the value measured by a non-contact laser microscope. In FIG. 8A, in addition to the above-mentioned modes A and B, a mode A'in which the unit region length is further increased (L3 = 80 mm) is prepared. Then, mode A'is set for plain paper having a surface roughness even larger than that of coated paper.

Mode A and mode A'are common in that nip transfer is interposed. However, in the mode A'in which the length of the unit region is large, the unevenness of the transport trace is more conspicuous than in the mode A because the nip transport distance is increased, and the throughput is faster. Therefore, in this modification, the mode A'is set for the plain paper having a surface roughness larger than that of the coated paper and the unevenness of the transport traces being less noticeable, and the throughput is improved as compared with the coated paper.

For glossy paper, semi-glossy paper, and film having a relatively small surface roughness, a mode B in which nip transfer is not interposed is set as in the first embodiment.

FIG. 8B shows a case where the recording mode is set according to the thickness of the recording medium even in the same coated paper. In the recording medium, the thicker the thickness, the stronger the nip pressure received during nip transfer, and the more easily the surface is deformed. Therefore, even if the recording medium is made of the same material, the larger the thickness, the more conspicuous the unevenness of the transport traces.

In FIG. 8B, the mode A'is set for the thinnest (90 μm) coated paper A. Mode A is set for coated paper B having a standard thickness (180 μm). Mode B is set for the thickest (300 μm) coated paper C.

FIG. 8C shows a case where the recording mode is set according to the ink absorption capacity even in the same coated paper. This is because the lower the ink absorption capacity of the recording medium, the easier it is for the ink to be transferred to the transfer mechanism during nip transfer, and the more likely it is that uneven transfer marks are confirmed. The ink absorption capacity can be quantified by various methods, but in FIG. 8C, the ink transfer amount is used as the ink absorption capacity.

The amount of metastasis was determined by the Japan TAPPI pulp and paper test method No. It can be measured by using the Bristow method described in 51, "Method for testing liquid absorption of paper and paperboard". Hereinafter, a method for measuring the amount of ink transfer will be briefly described. First, a certain amount of ink is injected into a holding container having an opening slit of a predetermined size. The ink in the container is brought into contact with the strip-shaped recording medium wound around the disk through a slit, and the disk is rotated while the holding container is fixed. Next, the area (length) of the ink band transferred to the recording medium is measured, and the transfer amount (ml / m ² ) per unit area is calculated from the area of the ink band. This transfer amount (ml / m ² ) indicates the amount of ink absorbed by the recording medium at a predetermined time, and the predetermined time is defined as the transfer time. The transition time (millisecond ^ 1/2) corresponds to the contact time between the slit and the recording medium, and is converted from the speed of the disk and the width of the opening slit.

In FIG. 8 (c), the mode A'is set for the coated paper D having the largest transfer amount (40 ml / m ² ). Mode A is set for the coated paper E having a standard transfer amount (30 ml / m ² ). Mode B is set for the coated paper F having the smallest transfer amount (18 ml / m ² ).

As described above, the recording mode for outputting an image with nip transfer and the recording mode for recording an image without nip transfer are appropriately set according to various elements of the recording medium. This makes it possible to stably output a high-quality image.

(Second Embodiment)
In the recording medium, the larger the amount of ink applied, the higher the possibility of deformation of the surface of the recording medium due to nip transfer and transfer to the transfer mechanism. Therefore, in the present embodiment, the recording mode is set according to the amount of ink applied to the recording medium, that is, based on the image to be recorded and the recording data.

FIG. 9 is a diagram showing a correspondence relationship between the amount of ink applied and the recording mode in the present embodiment. Here, the recording rate of dots with respect to a plurality of pixel regions arranged on a recording medium is shown as an ink application amount (%). When dots are recorded in all the pixel areas arranged on the recording medium, the ink application amount is 100%, and when dots are not recorded in all the pixel areas, the ink application amount is 0%. Such an ink application amount (recording rate) may be acquired by the host device 100 based on the image data, or may be acquired by the CPU 501 based on the recorded data generated by the image processing unit 505.

In the present embodiment, when the amount of ink applied is less than 30%, the CPU 501 sets the mode A'. When the amount of ink applied is 30% or more and less than 90%, the CPU 501 sets the mode A. When the amount of ink applied is 90% or more, the CPU 501 sets the mode B.

As described above, in the present embodiment, when recording an image in which the amount of ink applied is small and the unevenness of the transport trace is inconspicuous even with the same coated paper, the length of the unit area is set large and the throughput is increased accordingly. It is improving. On the other hand, when recording an image in which the amount of ink applied is large and unevenness of transport marks is easily noticeable, the length of the unit area is set small so that nip transport is not intervened.

Although FIG. 9A shows the recording rate for the pixel area of the entire page as the ink application amount, the method for calculating the ink application amount is not limited to this. For example, the entire pixel area of the recording medium may be divided into areas of a predetermined number of pixels, and the average of the recording rates obtained in each divided area may be used as the amount of ink applied to the page. Further, the maximum value of the recording rate in the plurality of divided areas may be used as the amount of ink applied to the page.

The recording mode described with reference to FIG. 9 can also be switched between different areas within the same page. For example, when the first object with a large amount of ink applied and the second object with a small amount of ink applied are arranged apart from each other in the transport direction, the first object records in mode B without nip transfer, and the second object records with nip transfer. You may record in mode A in which. In this case, the CPU 501 may acquire the amount of ink applied for each predetermined area in the transport direction and set the recording mode for each of the predetermined areas.

Further, when the CPU 501 has a unit area in which the ink application amount is 0%, the recording transfer step for the unit area may be omitted, and the recording medium may be collectively conveyed to the unit area in which the ink application amount is not 0%. Good. That is, the batch transport in which the empty transport in the unit region where the ink application amount is 0% and the recording transport in the unit region where the ink application amount is not 0% are collectively referred to as batch transport.

FIG. 10 is a diagram showing an example of the batch transfer. Here, the recording state of the mode A is shown when the amount of ink applied in the third to fifth unit regions is 0%. Compared with the standard 5-pass multi-pass recording shown in FIG. 6 (a), the same recording transfer as in FIG. 6 (a) is performed up to the 6th pass, but the recording for the 6th unit area is performed in the 7th pass. The recording media are collectively transported to a position where they can be transported. That is, in the 7th pass, the recording transfer for the 3rd to 5th unit areas is omitted, and the first recording transfer for the 6th unit area is performed. If such batch transfer is performed, the throughput can be improved by the amount that recording transfer is omitted.

In addition, in FIG. 10, the case of recording in the same recording mode (mode A) for both the first and second unit areas and the sixth and subsequent unit areas has been described, but these two areas are described. , You may record in different recording modes according to each ink application amount.

Further, such batch transportation is not limited to the present embodiment. Even when the recording mode is set based on the recording medium as in the first embodiment, if the region where the ink application amount is 0% can be detected, the recording transfer to the region is omitted and the ink is ink. It is possible to collectively transport to the next unit area where the grant amount is not 0%.

As described above, according to the present embodiment, the amount of ink applied to the recording medium is defined as a recording mode in which an image is output with nip transfer intervening and a recording mode in which an image is recorded without nip transfer. Set appropriately according to. This makes it possible to output a high-quality image regardless of the image data.

(Other embodiments)
The degree of conspicuousness of the transport trace unevenness may depend on various conditions other than the characteristics of the recording medium as described in the first embodiment and the amount of ink applied as described in the second embodiment. 11 (a) to 11 (c) are diagrams showing an example of the correspondence between the various conditions and the recording mode.

FIG. 11A shows a case where the recording mode is set according to the type of ink used. In general, dye inks tend to have high permeability and pigment inks tend to have low permeability to recording media. Since the pigment ink is more likely to remain on the surface of the recording medium than the dye ink, it is excellent in color development, but the unevenness of the transfer mark due to the nip transfer is easily noticeable. Therefore, in FIG. 11A, when the ink used is a dye ink, a mode A in which nip transfer is interposed is set, and when the ink used is a pigment ink, a mode B in which nip transfer is not interposed is set. .. In this way, it is possible to record a high-quality image without uneven transport traces regardless of the type of ink used.

FIG. 11B shows a case where the recording mode is set according to the environmental temperature. In general, the higher the environmental temperature, the lower the fixability of the ink to the recording medium, and the unevenness of the transport traces due to the nip transport becomes more noticeable. Therefore, in FIG. 11B, a mode A'for interposing nip transfer is set when the environmental temperature is less than 15 ° C., and a mode for intervening nip transfer when the environmental temperature is 15 ° C. or higher and lower than 28 ° C. Set A. Further, when the environmental temperature is 28 ° C. or higher, the mode B in which the nip transfer is not interposed is set. In this way, even if the environmental temperature at which the recording device is used changes, the recording mode suitable for each environmental temperature is set, and it is possible to record high-quality images without uneven transport traces as fast as possible. It becomes.

FIG. 11C shows a case where the recording mode is switched according to the environmental humidity. In general, the higher the environmental humidity, the lower the fixability of the ink on the recording medium, and the transfer and uneven transport traces associated with nip transport tend to be more noticeable. Therefore, in FIG. 11C, a mode A'for interposing nip transfer is set when the environmental humidity is less than 30%, and a mode for intervening nip transfer when the environmental humidity is 30% or more and less than 60%. Set A. Further, when the environmental humidity is 60% or more, the mode B in which the nip transfer is not interposed is set. In this way, even if the environmental humidity in which the recording device is used changes, the recording mode suitable for each environmental humidity is set, and a high-quality image without uneven transport traces can be recorded at the highest possible speed. It will be possible.

The embodiments and modifications described above can be combined with each other. For example, as a combination of the first embodiment and the second embodiment, the CPU 501 may be able to set the recording mode based on the type of the recording medium and the amount of ink applied. Further, even when the dye inks are used in combination with FIGS. 11A to 11C, the recording mode may be different depending on whether the environmental temperature or humidity is high or low. Such a configuration can be realized by storing in the ROM 502 a multidimensional table in which one recording mode is determined based on a plurality of parameters such as a recording medium type, an ink application amount, and an environmental temperature. The CPU 501 may set one recording mode based on a plurality of parameters by referring to the multidimensional table.

In addition, the types of recording modes are not limited to the three types shown in the above embodiments. A plurality of recording modes in which the unit area lengths are further different may be prepared in each of the mode in which the nip transfer is interposed and the mode in which the nip transport is not interposed.

Further, a plurality of recording modes having different numbers of multipaths may be prepared. For example, in the first embodiment, when the recording medium is plain paper, the 5-pass multipath recording shown in FIG. 6A is performed, and when the recording medium is coated paper, it is shown in FIGS. 4 and 5. 8-pass multipath recording may be performed. In both multipath recordings, if the unit area length is L1, nip transfer is interposed.

The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

1 Inkjet recording device 2 Inkjet recording head 7 Conveyor roller pair (conveyance mechanism)
501 CPU
P Recording medium

Claims (15)

A recording head with an array of ink ejection nozzles,
It is provided at a position upstream of the recording head in the transport direction intersecting the direction of the arrangement, and while niping the recording medium, the recording medium is transported in the forward direction in the transport direction and in the opposite direction to the forward direction. With a transport mechanism that can be
A recording transfer in which the recording medium is conveyed to the transfer mechanism in the forward direction while ejecting ink to the recording head, and a recording transfer in which the transfer mechanism conveys the recording medium in the opposite direction while ejecting ink to the recording head. A control means for completing an image of a unit region on the recording medium having a predetermined length in the transport direction by the plurality of record transports by alternately performing recording transports.
A plurality of recordings including a first recording mode in which the length of the unit region in the transport direction is the first length, and a second recording mode in which the length of the unit region is smaller than the first length. A setting means for setting one recording mode from the modes, and
It is an inkjet recording device equipped with
The first recording mode includes nip transport in which the unit region is transported while being niped by the transport mechanism during the plurality of recording transports for completing an image of the unit region.
The second recording mode is an inkjet recording apparatus that does not include the nip transfer between the plurality of recording transfer for completing an image of the unit area. The inkjet recording apparatus according to claim 1, wherein the setting means sets the recording mode according to the type of the recording medium. The setting means sets the first recording mode for a recording medium having a surface roughness of a first value, and sets a recording medium having a surface roughness of a second value smaller than the first value. The inkjet recording apparatus according to claim 1, wherein the second recording mode is set. The setting means sets the first recording mode for a recording medium having a first thickness, and sets the second recording mode for a recording medium having a second thickness larger than the first thickness. The inkjet recording apparatus according to claim 1. The setting means sets the first recording mode for a recording medium having a transfer amount of the first value, and the setting means for a recording medium having a second value of the transfer amount smaller than the first value. The inkjet recording apparatus according to claim 1, wherein a second recording mode is set. When the amount of ink applied to the recording medium is the first value, the setting means sets the first recording mode, and the amount of ink applied is a second value larger than the first value. The inkjet recording apparatus according to claim 1, wherein the second recording mode is set in some cases. Further provided is a means for obtaining the amount of ink applied for each region of the recording medium in the transport direction.
The setting means sets the first recording mode for the region where the grant amount is the first value, and the first setting means for the region where the grant amount is a second value larger than the first value. 2. The inkjet recording apparatus according to claim 1, wherein a recording mode is set. The setting means according to claim 1, wherein the first recording mode is set when the ink is a dye ink, and the second recording mode is set when the ink is a pigment ink. Ink recording device. The setting means sets the first recording mode when the environmental temperature is the first temperature, and sets the second recording mode when the environmental temperature is a second temperature higher than the first temperature. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is set. The setting means sets the first recording mode when the environmental humidity is the first humidity, and sets the second recording mode when the environmental humidity is a second humidity higher than the first humidity. The inkjet recording apparatus according to claim 1, wherein the setting is made. When there is a region in which ink is not applied in the transport direction, the control means does not perform the record transport to the region, and the record transport is performed on the unit region located upstream of the transport direction. The inkjet recording apparatus according to any one of claims 1 to 10, wherein the recording media are collectively conveyed to a possible position. In the control means, twice the first length is larger than the distance from the position of the nozzle located at the most downstream in the positive direction of the recording head to the nip portion of the transport means, and the control means has the second length. The inkjet recording apparatus according to any one of claims 1 to 11, wherein the distance is twice as small as the distance. The inkjet recording according to any one of claims 1 to 12, wherein the plurality of modes further include a third recording mode having a third length larger than the first length. apparatus. The inkjet recording apparatus according to any one of claims 1 to 13, wherein the plurality of modes include modes in which the number of recording transports for completing an image in the unit region is different from each other. .. A recording head with an array of ink ejection nozzles,
It is provided at a position upstream of the recording head in the transport direction intersecting the direction of the arrangement, and while niping the recording medium, the recording medium is transported in the forward direction in the transport direction and in the opposite direction to the forward direction. With a transport mechanism that can be
Using an inkjet recording device equipped with
A recording transfer in which the recording medium is conveyed to the transfer mechanism in the forward direction while ejecting ink to the recording head, and a recording transfer in which the transfer mechanism conveys the recording medium in the opposite direction while ejecting ink to the recording head. An inkjet recording method in which an image of a unit region on a recording medium having a predetermined length in the transport direction is completed by a plurality of the recording transports by alternately performing recording transports.
The length of the unit region in the transport direction is the first length, and the unit region is transported while being nipated by the transport mechanism during the plurality of recording transports for completing an image of the unit region. The first recording mode in which the nip transfer is performed and
The length of the unit region in the transport direction is a second length smaller than the first length, and the nip transport is performed during the plurality of recording transports for completing an image of the unit region. The second recording mode without intervention and
An inkjet recording method comprising a step of setting.

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