JP2000118012A - Method and apparatus for recording image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a print head from being clogged with ink while avoiding complication of the print head and eliminating an extra time. SOLUTION: When ink drops are discharged from a print head 200 of an on-demand system which discharges ink drops to a recording sheet held on a hold face of a rotating cylinder 100, images are recorded through the rotation of the cylinder 100 as a main scan. According to this method for recording images, ink drops are idle discharged from the print head 200 to at least either of non-image areas forward and rearward in a rotation direction of the cylinder 100 of an image record area of the recording sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image recording method and an image recording apparatus for recording an image on a recording sheet.

[0002]

2. Description of the Related Art In recent years, a color separation halftone original film image data, a photo halftone original image data and a solid image halftone original image data have been separated by a device called DTP, not by cutting and pasting a color separation halftone original film. From the image data such as, cut and paste on the image data, create color separation network image data, with a device called imagesetter,
A color separation screen original film is prepared from the color separation screen image data, and a printing plate is directly prepared by a device called CTP.

[0003] The calibration work performed by such a system using DTP includes not only a method of preparing a color separation screen original film from color separation screen image data and forming a color proof from the color separation screen document film, but also a method of preparing a color proof. DDCP, which creates a color proof directly from the decomposition network image data,
It has been done recently.

[0004] The DDCP includes a method of producing a color proof by exposing a silver halide color photographic light-sensitive material with an LED or a laser beam based on the color separation image data. There are, for example, a type in which a color proof is created by an ink transfer printing method, and a type in which a color proof is created by an inkjet printing method based on color separation halftone image data.

[0005] In the case of producing a color proof by exposing a silver halide color photographic light-sensitive material,
There is a problem that it is necessary to use a processing liquid or a waste liquid of the processing liquid is generated. Further, in the ink transfer printing method, there is a problem that an ink sheet after transferring the ink is generated as a waste material.

[0006] On the other hand, those using the ink jet printing method record images by ejecting minute droplets of ink onto a recording sheet such as paper.
High-speed printing is possible, it is inexpensive, and there is little generation of waste liquid and waste material.

[0007] DDCPs using such an ink-jet printing method include Y (yellow), M
(Magenta), C (cyan) and K (black)
2. Description of the Related Art An ink jet printer provided with a print head is known. This ink jet printer has a cylinder holding a recording sheet on a holding surface, and a plurality of print heads provided with only one nozzle, and constantly ejects droplets from the nozzle at regular intervals, A continuous type of recording an image by deflecting the ejected droplets so that the image is recorded on the image recording surface of the recording sheet held in a cylinder, or is prevented from hitting the recording sheet. Met.

Although not for DDCP, Y, M,
An ink jet printer having a print head for each of the C and K colors. A single print head is provided with a plurality of nozzles, and these nozzles are used to print images on a recording sheet conveyed by a belt at high speed. Some records are also known. Note that the on-demand method is a method of recording an image corresponding to image data on a recording sheet by ejecting or not discharging a droplet according to image data.

[0009]

In the case of an on-demand type print head, if image data that does not eject ink droplets continues, ink clogging may occur in the print head. Therefore, the print head itself is provided with a cap that can move so as to cover the discharge direction of the print head ink, and the cap that discharges the ink idle or the print head that can move in the direction parallel to the cylindrical axis of the cylinder are not used. There is a type in which a blank discharge space is provided in a place other than the recording sheet, and the print head is moved to the blank discharge space at regular time intervals to perform a blank discharge of ink droplets.

However, when the cap is provided on the print head, the print head becomes complicated, and it is necessary to increase the space between the print head and the recording sheet. Also, to move the print head to the idle discharge space at regular intervals in the direction parallel to the cylinder axis of the print head that discharges ink droplets, and to perform idle discharge, There is waste.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an image recording method and an image recording method for preventing ink clogging of a print head without complicating the print head and eliminating unnecessary time. It is intended to provide a device.

[0012]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to the first aspect of the present invention, there is provided a method for ejecting ink droplets from an on-demand type print head which ejects ink droplets onto a recording sheet held on a holding surface of a rotating cylinder. In an image recording method for recording an image as rotation is a main scan, the print head idle-discharges at least one non-image area in the rotation direction of the cylinder in the image recording area of the recording sheet in the front or rear direction. An image recording method, comprising: ].

According to the first aspect of the present invention, since ink droplets can be ejected as they are during image recording, there is no need to provide a dedicated space for empty ejection of ink. No extra time is required to move the printhead, the printhead does not need to be complicated, and ink clogging of the printhead can be prevented.

According to a second aspect of the invention, there is provided an image forming apparatus comprising: a cylinder for holding a recording sheet on a holding surface; and an on-demand type print head for ejecting ink droplets, wherein the recording sheet is placed on the holding surface of the cylinder. An image recording apparatus that records an image on a recording sheet held on a holding surface of the cylinder by ejecting ink droplets from the print head while rotating the cylinder as a main scan while holding the recording sheet. An image recording apparatus characterized in that the print head idle-discharges at least one non-image area in the rotation direction of the cylinder in the image recording area. ].

According to the second aspect of the present invention, since the ink droplets can be idle-discharged during the image recording, there is no need to provide a dedicated space for the idle discharge of the ink, and the ink droplets are placed in a dedicated space for each idle discharge. No extra time is required to move the printhead, the printhead does not need to be complicated, and ink clogging of the printhead can be prevented.

According to a third aspect of the present invention, there is provided a recording sheet held on a holding surface of the cylinder by ejecting ink droplets from the print head in accordance with image data corresponding to color separation image data. 3. The image recording apparatus according to claim 2, wherein a color proof image corresponding to the color separation halftone image data is recorded. ].

According to the third aspect of the present invention, since the ink droplets can be ejected as they are during the image recording, the delicate color as in the case where the image recording is interrupted and the ink droplets are ejected during the image recording. The generation of unevenness can be prevented and a good color proof can be created.

According to a fourth aspect of the present invention, there is provided a method as described above, wherein the holding surface is
The print head has a substantially cylindrical shape, and has a cylindrical rotating means for rotating the cylinder about a substantially cylindrical axis of the cylindrical surface, and the print head includes a plurality of nozzles for discharging ink droplets. The image recording apparatus according to claim 2, wherein the print head is a print head. ].

Hereinafter, the fourth aspect of the present invention will be described in detail.

According to the fourth aspect of the present invention, the cylinder rotates substantially around the cylinder axis while fixedly holding the recording sheet on the cylindrical holding surface.
The image recording surface of the recording sheet passes through a predetermined position in a predetermined direction. Accordingly, the distance between the leading end of the print head and the image recording surface of the recording sheet can be made very small, and the accuracy of the mounting position and direction of the print head with respect to the image recording surface of the recording sheet can be made extremely high. Therefore, even when using an on-demand type print head provided with a plurality of nozzles in which the ejection direction of ink droplets is not so constant, image recording can be performed without moving the print head to an empty ejection space or capping. During this time, the ink droplets can be ejected as they are, so that the positional accuracy of the ink droplets ejected from the print head and recorded on the image recording surface of the recording sheet can be extremely increased, and ink clogging can be prevented. Therefore, ink clogging can be prevented while a highly reproducible high-definition image can be recorded. Also, when creating a color proof, a color proof that can be used favorably for proofing can be created.

The holding surface for holding the recording sheet fixedly may be an outer peripheral surface of a cylinder or a hollow cylinder, and may be an inner peripheral surface of the cylinder. And when the holding surface is the outer peripheral surface of the cylinder, it is desirable to hold the image recording surface of the recording sheet so that it faces outward, and when a hollow cylinder is used and the holding surface is the inner peripheral surface of this cylinder, It is desirable to hold the recording sheet so that the image recording surface faces inward, but it is not limited to these.

The cylindrical axis and the cylindrical surface are a cylindrical axis and a cylindrical surface in a geometric sense, and the cylindrical axis is a straight line.
The cylindrical surface is a surface formed by a straight line parallel to the cylinder axis and passing through a circumference on a plane perpendicular to the cylinder axis.

Further, the holding surface is a surface of a portion where the recording sheet is held in the area for holding the recording sheet, and the holding surface is substantially a cylindrical surface. The location where the recording sheet is held may be substantially a cylindrical surface, and the other areas may be concave or substantially non-cylindrical, such as not being present, or substantially not. It may be a cylindrical surface. Further, the recording sheet may be held at all points in the area for holding the recording sheet, but for example, the recording sheet such as a groove, a hole, a slit, or a hole is not held in a part of the area for holding the recording sheet. Even if the location is provided, the location for holding the recording sheet in the area for holding the recording sheet may be a substantially cylindrical surface.

The holding surface is substantially cylindrical when the variation in the distance of the holding surface with respect to the cylinder axis is within a range where the quality of the recorded image does not substantially matter. The variation in the distance of the surface to the cylinder axis is
It is preferably within 0.5 mm or less.
It preferably falls within 3 mm or less (particularly 0.1 mm or less).

In addition, "to rotate substantially around the cylindrical axis of the cylindrical surface" means that the rotation is made around the cylindrical axis of the cylindrical surface as a rotation axis, and the eccentricity (distance of the rotation axis with respect to the cylindrical axis) is recorded. The image quality is within a range in which the image quality does not substantially matter, and the eccentricity is preferably within 0.5 mm or less, and more preferably within 0.3 mm or less (especially 0.1 mm or less). .

The direction of the axis of the cylinder is preferably substantially horizontal, but may be vertical or oblique.

Examples of the form in which the cylinder fixedly holds the recording sheet, such as the form in which the cylinder fixedly holds the recording sheet by electrostatic attraction, the form in which the cylinder fixedly holds the recording sheet by means of a magnet, And a mode in which the cylinder holds the recording sheet fixedly by vacuum suction, but is not limited thereto.

The distance between the print head and the recording sheet is preferably regulated to 1 cm or less, and more preferably to 2 mm or less (particularly 1 mm or less).

The color proof image corresponding to the color separation network image data is a color proof image that simulates a printed matter created from the color separation network image data. Further, the image data corresponding to the color separation network image data may be image data corresponding to the color separation network image data, and is not limited to the color separation network image data itself. The continuous tone original image data input to the halftone image processing device that generates the color separation halftone image data, and the continuous tone processing device that converts the color separation halftone image data into the continuous tone image data. The image data may be continuous tone image data obtained by converting the decomposed net image data.

According to a fifth aspect of the present invention, there is provided an image recording apparatus according to the first aspect, wherein the cylindrical axis of the cylinder is substantially horizontal, and the print head ejects ink droplets downward from a position above the recording sheet to record an image on the recording sheet. The image recording apparatus according to claim 4, wherein an image is recorded on the surface. ].

Hereinafter, the invention according to claim 5 will be described in detail.

According to the fifth aspect of the present invention, as compared with the case where the print head ejects ink droplets in the upward or horizontal direction to record an image on the image recording surface of a recording sheet held in a cylinder, , And the positional accuracy of ink droplets recorded on the image recording surface of the recording sheet can be increased. Therefore, a very high-definition image with very high reproducibility can be recorded.

When a color proof is created, a color proof that can be used well by calibration can be created. Further, since the cylinder axis of the cylinder is substantially horizontal and the print head ejects ink droplets downward from a position above the recording sheet to record a color proof image on the image recording surface of the recording sheet, May be a large one that holds a large size recording sheet for color proof, or the horizontal cross-sectional area of the structural material for increasing the accuracy between the cylinder and the print head may be small, A color proof that can be used favorably by proofing can be created while reducing the overall cost.

It is to be noted that the cylindrical axis of the cylinder is substantially horizontal,
It is sufficient that the horizontal cross-sectional area of the structural material for increasing the accuracy between the cylinder and the print head is small, and it is sufficient that the position accuracy of the ink droplets is higher. Absent. The angle of the axis of the cylinder with respect to the horizontal plane is preferably 20 ° or less, and more preferably 5 ° or less (especially 1 ° or less).

Further, discharging ink droplets downward means that:
It is sufficient that the ink droplet is ejected in a downward direction so as to increase the positional accuracy of the ink droplet, and it is not necessary to be completely vertically downward. The angle of the direction in which the ink droplets are ejected with respect to the vertically downward direction is preferably equal to or less than a half-perpendicular angle, and more preferably equal to or less than 20 ° (particularly, equal to or less than 5 °).

According to a sixth aspect of the invention, there is provided a moving means for moving the print head in a direction parallel to the cylinder axis at least over an image recording width, and wherein the plurality of nozzles are arranged on the cylinder axis. 5. The width in which the plurality of nozzles are arranged side by side in a direction substantially parallel to the width of the plurality of nozzles is smaller than the image recording width.
Or the image recording device according to claim 5. ].

Hereinafter, the invention according to claim 6 will be described in detail.

According to the sixth aspect of the present invention, since the plurality of nozzles are juxtaposed in a direction substantially parallel to the cylinder axis, the height and direction of the plurality of nozzles with respect to the image recording surface are different. Variations can be easily reduced, and the width at which the plurality of nozzles are juxtaposed is narrower than the image recording width.
Compared to arranging a plurality of nozzles in parallel over the image recording width, it is easier to create a print head in which a plurality of nozzles are arranged with necessary accuracy, and the holding means connects the print head to the cylindrical shaft. Can move across the image recording width in a direction parallel to the image recording area, so that images can be recorded over the entire image recording area of the recording sheet, and at a lower cost than arranging multiple print heads to cover the entire image recording width. , Easy to achieve high precision.

As described above, the cost of the entire apparatus can be reduced while a higher quality image can be recorded.

It should be noted that a plurality of nozzles being juxtaposed in a direction substantially parallel to the cylinder axis means that the direction in which the plurality of nozzles are arranged and the cylinder axis are completely parallel. However, the direction in which the plurality of nozzles are arranged and the column axis may be approximately parallel to such an extent that variations in height and direction of the plurality of nozzles with respect to the image recording surface can be reduced. The deviation angle φ between the direction in which a plurality of nozzles are arranged and the direction of the cylinder axis is determined by the width of the plurality of nozzles arranged in the circumferential direction of the cylinder (the direction in which the plurality of nozzles are arranged). (W) from the center of the nozzle at one end to the center of the nozzle at the other end).

Φ <tan ⁻¹ (S / W) As a result, a high-quality image can be recorded without performing image processing for deforming the image. Further, it is preferable that the following expression is further satisfied.

Φ <tan ⁻¹ (0.3 × S / W) The invention according to claim 7 is characterized in that “the print head has a restricting means for restricting a position of the print head in a direction perpendicular to the cylindrical axis. The image recording apparatus according to claim 4, wherein ].

According to the present invention, not only can the position of the print head in the direction perpendicular to the cylinder axis of the cylinder be regulated, but also the position of the print head in the cylinder axis direction can be easily regulated. It is easy to prevent the position of the image recorded on the recording sheet from being slightly shifted before and after the movement in the direction parallel to the cylinder axis. Therefore, a higher quality image can be recorded.

The restricting means only needs to restrict the position of the print head in the direction perpendicular to the column axis. For example, a column-shaped guide provided in parallel with the cylinder axis of the cylinder; This guide is fitted, and a combination with a holding member that holds the print head, a guide groove provided in parallel with the cylindrical axis of the cylinder, and a holding member that fits in the guide groove and holds the print head. But not limited to these. Further, examples of the column shape include a prism shape such as a quadrangular prism shape, a column shape, and the like, but are not limited thereto.

According to an eighth aspect of the present invention, there is provided an image processing apparatus comprising a nozzle head having a plurality of nozzles arranged in parallel for each color of color separation image data. The image recording device according to any one of the above. ].

According to the eighth aspect of the present invention, since a nozzle head having a plurality of nozzles arranged in parallel for each color of the color separation network image data is provided, one nozzle head can store the color separation network image data. From those with nozzles for all colors,
Since an image can be recorded at a high speed even if the number of nozzles per nozzle head is small, the image recording speed is high and a print head can be easily created. Therefore, the cost of the entire apparatus can be reduced while an image can be recorded at a higher speed.

According to a ninth aspect of the present invention, there is provided a sheet feeding means for feeding a recording sheet onto the holding surface of the cylinder, and a recording sheet fed to the sheet feeding means on the holding surface of the cylinder. 9. The image recording apparatus according to claim 4, further comprising a pressing roller for pressing. ].

According to the ninth aspect of the present invention, since the recording sheet fed onto the holding surface of the cylinder is pressed against the holding surface of the cylinder by the pressing roller, the recording sheet is easily brought into close contact with the cylinder.

According to a tenth aspect of the present invention, the sheet feeding means feeds the recording sheet onto the outer peripheral surface of the cylinder without rubbing the image recording surface. Item 10. The image recording apparatus according to Item 9. ].

According to the tenth aspect of the present invention, the recording sheet can be fed without rubbing the image recording surface, so that a high-density image recording that absorbs a large amount of ink per unit area can be easily recorded. In addition, damage due to feeding can be prevented. Therefore, it is possible to record an image reproduced up to a high-density area with little damage.

According to an eleventh aspect of the present invention, the sheet feeding means includes: a guide for guiding a back surface of the recording sheet;
The image recording apparatus according to claim 10, further comprising: a feeding roller pair configured to feed a recording sheet. ].

According to the eleventh aspect of the present invention, the recording sheet is capable of being fed without rubbing the image recording surface, so that a high-density image recording which absorbs a large amount of ink per unit area can be easily damaged. In addition, damage due to feeding can be prevented. Therefore, an image reproduced up to a high-density area with less flaws can be recorded.

According to a twelfth aspect of the present invention, there is provided an image forming apparatus according to any one of the fourth to eleventh aspects, further comprising a sheet discharging means for discharging a recording sheet from the outer peripheral surface of the cylinder without rubbing the image recording surface. Image recording device. ].

According to the twelfth aspect of the present invention, since the image can be discharged without rubbing the image recording surface, even a recording sheet which is easily damaged and capable of recording a high density image such that a large amount of ink is absorbed per unit area. In addition, damage due to discharge can be prevented. Therefore, an image reproduced up to a high-density area with less flaws can be recorded.

[0056]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an image recording method and an image recording apparatus according to the present invention will be described below. In addition,
The present invention is not limited to the embodiments described below. In the following description, there may be a description explaining the meaning of the term, but it is merely to explain the meaning of the term in the embodiment, and the meaning of the term of the present invention is not limited to this description. .

The image recording apparatus according to this embodiment is a color proof creating apparatus capable of recording a color proof image by ejecting ink droplets on an image recording surface of a recording sheet based on color separation halftone image data. FIG. 1 is a schematic perspective view of the color proof creating apparatus of this embodiment, with a part thereof cut away, FIG. 2 is a schematic front view of the internal structure thereof, and FIG. This will be described with reference to FIG.

As a recording sheet 1 on which an image is recorded by the color proof forming apparatus,
It is preferable that an ink absorbing layer having a large amount of ink absorbed per unit area is provided, thereby enabling good tone reproduction from high density to low density. The ink absorbing layer is preferably a void layer containing inorganic fine particles and a hydrophilic binder. Recording sheet 1
The back surface opposite to the image recording surface is formed as a slippery surface.

The sheet cassette 500 can stack and store a plurality of recording sheets 1 so that the image recording surface faces upward. And the feeding roller 410 is
The uppermost recording sheet 1 of the plurality of recording sheets 1 deposited
It is designed to be fed from.

In this color proof forming apparatus, the recording sheets 1 are taken out one by one from the sheet cassette 500, supplied to the cylinder 100, wound around the cylinder 100, and
Print head 20 on recording sheet 1 held by
0 records an image by discharging ink droplets, and the recording sheet 1 on which the image is recorded is discharged to the discharge tray 310. The color proof creating apparatus converts the color separation image data into continuous tone while rotating the cylinder 100 at a constant speed as main scanning while holding the recording sheet 1 on the holding surface of the cylinder 100. A print head 200 based on the obtained continuous tone image data
A color proof image corresponding to the color separation halftone image data is recorded on the image recording surface of the recording sheet 1 fixedly held on the holding surface of the cylinder 100 by discharging ink droplets from the cylinder.

The color proof forming apparatus supplies the recording sheet 1 to the cylinder 100 from the sheet cassette 500 disposed below the cylinder 100 and the discharge tray 310. The color proof forming apparatus includes a feed roller 410 that feeds only one recording sheet stacked on the uppermost portion of the sheet cassette 500 while separating it by a difference in frictional force.
And a first transport roller pair 4 that transports the recording sheet 1 therebetween.
20, a first supply guide 430 for guiding the back side of the recording sheet 1, a second pair of conveyance rollers 440 for conveying the recording sheet 1 therebetween, a second supply guide 450 for guiding the back side of the recording sheet 1, and recording. A pressing roller 460 for pressing the sheet 1 against the cylinder 100 is provided, and the recording sheet 1 is transported from the sheet cassette 500 to the cylinder 100 while being turned upside down and fed.

Further, the cylinder 100 has a holding surface on the outer peripheral side for fixedly holding the recording sheet 1 wound around the recording sheet 1 with the image recording surface facing outward during image recording. The shape of the holding surface of the cylinder 100 is a cylindrical surface, and the variation in the distance of the holding surface with respect to the cylindrical axis is 0.0.
It is less than 5 mm. And this cylinder 100
Are arranged so that the cylindrical axis of the cylindrical surface is horizontal and rotate about this cylindrical axis, and the eccentricity is within 0.1 mm or less. The cylinder 100 is rotated at a constant rotation speed by a motor (not shown) during image recording.

The carriage 230 holds the print head 200 fixedly. Also, print head 2
Reference numeral 00 denotes an on-demand type print head, as shown in FIG.
217 are provided, and each nozzle head table 211, 2
13, 215, and 217 are each provided with two nozzle heads. In each of the nozzle heads 221 to 228, a plurality of nozzles 220 are provided so that all the deviation angles φ are smaller than the image recording width φ <tan ⁻¹ (0.3 ×
(S / W), they are arranged side by side in the column axis direction of the cylinder 100. These nozzles 220 are ink jet nozzles of an on-demand system, which discharge ink droplets only for pixels for which ink recording is required, and discharge ink droplets in the vertical direction.

A quadrangular carriage guide 245 for guiding the print head 200 in the direction of the cylinder axis of the cylinder 100 while regulating the position of the print head 200 in the direction perpendicular to the cylinder axis of the cylinder 100 is provided. , The carriage 230 is provided with a hole in which the carriage guide 245 is movable, and a belt is fitted over a pulley 250 fixed to the motor shaft of the motor 240 and a pulley 270 held rotatably. The carriage 230 is fixed to the carriage 260, and the motor 240 rotates the pulley 250 so that the carriage guide 2
45 guides the carriage 230 and print head 2
The carriage 230 is moved in the direction of the cylinder axis of the cylinder 100 over a width wider than the image recording width so that 00 is always located in the vertical direction of the cylinder axis of the cylinder 100.

Further, ink containers 271 to 278 are provided on the ink container holding plate 280 for each of the nozzle heads 221 to 228. Then, the nozzle heads 221 to 22
8 and the corresponding ink containers 271 to 278, the nozzle heads 221 to 228 and the corresponding ink containers 271 to 278 are connected to the flexible pipes 291 and 292, respectively.
Connected through. The pipe 292 has one end connected to the carriage main body 230 and the other end connected through a tractor unit 295 fixed to the ink container holding plate 280.

In the color proof forming apparatus, the print head 200 ejects ink droplets while rotating the cylinder 100 fixedly holding the recording sheet 1 on the holding surface, thereby recording the image on the recording sheet 1. The recording of a part of the image in the area and the movement of the print head 200 in the cylindrical axis direction of the cylinder 100 by the motor 240 are alternately performed, and the image of the entire image recording area of the recording sheet 1 is recorded. At this time, the interval between the print head 200 and the recording sheet 1 is restricted to 1 mm or less.

After the image formation is completed, the motor 2
The rotation of the pulley 250 causes the carriage 230 to move in the cylindrical axis direction of the cylinder 100, and the print head 200 to move above the maintenance unit 600,
Sucking, cleaning and capping are performed.
The sucking is performed by sucking the ink in the nozzles 220 from the ink droplet ejection direction of the print head 200, the cleaning is performed by cleaning the ink droplet ejection surface of the print head 200 with a wiper or the like, and the capping is performed by cleaning the print head 200. This is to cover the ink droplet ejection surface with a cap.

The color proof forming apparatus includes a discharge guide 350 for separating the recording sheet 1 on which an image is recorded from the cylinder 100 and discharging the recording sheet 1, and a discharge tray 310 provided on the side of the cylinder 100. The recording sheet 1 having the image recorded by the cylinder 100 is discharged to a discharge tray 310.

Further, the discharge guide 350 guides the back surface of the recording sheet 1 from the side of the cylinder 100 to the discharge tray 310, so that the recording sheet 1 released from being fixedly held by the cylinder 100 is moved by gravity. Discharge tray 31
Lead to zero. Then, the recording sheet 1 is discharged to the discharge tray 310 with the image recording surface facing up.

The discharge tray 310 has a plurality of recording sheets 1.
Can be accommodated. In addition, the discharge tray 310
The recording sheet 1 is provided obliquely so that the height on the side of the cylinder 100 is increased, and accommodates the discharged recording sheet 1 obliquely.

The discharge tray 310 has a bat 330 slidable in the direction indicated by the arrow in FIG. 1, and stores the discharged recording sheet 1 in a state where the bat 330 is slid and pulled out. . When the sheet cassette 500 is replaced, the recording sheet 1 cannot be supplied from the sheet cassette 500, so that the bat 330 can be pushed in.
Since the sheet cassette 500 is replaced, the sheet cassette 500 can be easily replaced.

The print head 200 may be provided with a recording sheet, for example, a heater may be provided inside the cylinder 100, an infrared lamp may be provided at a position facing the discharge guide 350, or an infrared lamp may be provided next to the print head 200. The structure is such that the recording sheet 1 is dried from the time when the ink droplets are ejected to the image recording surface of the first recording sheet 1 until the time when the recording sheet 1 is discharged to the discharge tray 310.

FIG. 4 is a plan view showing a state where the recording sheet is held on the holding surface of the cylinder 100, and FIG. 5 is a plan view of the recording sheet.

In this color proof forming apparatus, during image recording, the non-image recording areas 1c and 1d of at least one of the image recording area 1a of the recording sheet 1 at the front or rear in the rotation axis direction of the cylinder 100 in the image recording area 1a. 1 per revolution
All the nozzles 220 of one nozzle head are vacantly ejected with the empty ink in order, and the ink droplets are vacantly ejected from the nozzles 220 of all the nozzle heads with 8 rotations, thereby causing the print head 200 to vacantly eject the ink droplets. I do. This prevents occurrence of ink clogging in all the nozzles 220 of the print head 200.

[0075]

According to the present invention, it is not necessary to complicate the print head, and it is possible to prevent the clogging of the print head with ink while consuming unnecessary time.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view in which a part of a color proof creating device is cut away.

FIG. 2 is a schematic front view of the internal structure of the color proof creating device.

FIG. 3 is a diagram of the print head viewed from its discharge direction.

FIG. 4 is a plan view of a recording unit.

FIG. 5 is a plan view of a recording sheet.

[Explanation of symbols]

 Reference Signs List 1 recording sheet 1a image portion 1c, 1d non-image portion 100 cylinder 200 print head 230 carriage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 EA14 EC03 EC54 EC59 EE08 FA02 FA10 FA14 HA28 HA29 HA33 HA38 5C079 HB03 KA01 KA12 KA15 NA00 PA03

Claims (12)

[Claims] An ink droplet is ejected from a print head of an on-demand type which ejects an ink droplet onto a recording sheet held on a holding surface of a rotating cylinder. An image recording method for recording an image on a recording sheet, wherein the print head idle-discharges an ink droplet from the print head to at least one non-image area in the rotation direction of the cylinder in the image recording area of the recording sheet. Method. 2. A cylinder for holding a recording sheet on a holding surface;
An on-demand print head that ejects ink droplets, and ejects ink droplets from the print head while rotating the cylinder as main scanning while holding a recording sheet on the holding surface of the cylinder. Thus, in an image recording apparatus that records an image on a recording sheet held on the holding surface of the cylinder, the image recording area of the recording sheet in at least one non-image area in the front or rear in the rotation direction of the cylinder, An image recording apparatus, wherein ink droplets are ejected from a print head. 3. The image processing apparatus according to claim 1, wherein the print head ejects ink droplets in accordance with image data corresponding to the color separation screen image data, thereby printing the color separation screen image data on a recording sheet held on a holding surface of the cylinder. 3. The image recording apparatus according to claim 2, wherein a color proof image corresponding to the image is recorded. 4. The printing apparatus according to claim 1, wherein the holding surface has a substantially cylindrical shape, and has a cylinder rotating means for rotating the cylinder about a substantially cylindrical axis of the cylindrical surface. The image recording apparatus according to claim 2, wherein the image recording apparatus is a print head in which a plurality of nozzles that eject droplets are arranged in parallel. 5. The image forming apparatus according to claim 1, wherein the cylindrical axis of the cylinder is substantially horizontal, and the print head ejects ink droplets downward from a position above the recording sheet to record an image on an image recording surface of the recording sheet. The image recording apparatus according to claim 4, wherein: 6. A moving means capable of moving the print head in a direction parallel to the cylinder axis over at least an image recording width, wherein the plurality of nozzles are arranged in a direction substantially parallel to the cylinder axis. The image recording apparatus according to claim 4, wherein a width of the plurality of nozzles arranged side by side is narrower than an image recording width. 7. An image recording apparatus according to claim 4, further comprising regulating means for regulating a position of said print head in a direction perpendicular to said cylindrical axis. 8. The image according to claim 4, further comprising a nozzle head having a plurality of nozzles arranged in parallel for each color of the color separation image data. Recording device. 9. A sheet feeding means for feeding a recording sheet onto the holding surface of the cylinder, and a pressing roller for pressing the recording sheet fed to the sheet feeding means against the holding surface of the cylinder. The image recording apparatus according to any one of claims 4 to 8, wherein: 10. An image recording apparatus according to claim 9, wherein said sheet feeding means feeds a recording sheet onto the outer peripheral surface of said cylinder without rubbing an image recording surface. . 11. An image recording apparatus according to claim 10, wherein said sheet feeding means has a guide for guiding the back side of the recording sheet, and a pair of feeding rollers for feeding the recording sheet. 12. The image recording apparatus according to claim 4, further comprising a sheet discharging means for discharging the recording sheet from the outer peripheral surface of the cylinder without rubbing the image recording surface.