JP2004174742A - Ink jet printer and its image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet printer capable of obtaining a high quality image through a simple structure by ejecting ink to a sheet and then fixing the ink. <P>SOLUTION: The ink jet printer for forming an image by ejecting ink to a sheet comprises a means for carrying the sheet by rotating a sheet holding drum holding the sheet on the outer circumferential surface thereof, a means for holding the sheet at a specified position of the sheet holding drum, a means for writing an image on the sheet held on the sheet holding drum by ejecting ink from an ink jet recording head, a means for fixing the ink ejected onto the sheet, and a means for separating the fixed sheet from the sheet holding drum. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink-jet printer and an image forming method of the ink-jet printer, and more particularly to an ink-jet printer that forms an image by ejecting ink onto paper and an image forming method of the ink-jet printer.
[0002]
[Prior art]
In recent years, the ink jet recording method has been applied to various printing fields such as photographs, various printings, special printings such as markings and color filters, since images can be easily and inexpensively formed. In particular, a recording device that ejects and controls fine dots, and ink with improved color reproduction range, durability, and jetting suitability, ink absorptivity, coloring of coloring materials, surface gloss, etc. have been dramatically improved. Using special paper, it is also possible to obtain image quality comparable to silver halide photography. The improvement in image quality of today's ink jet recording system has been achieved only when all of the recording apparatus, ink, and special paper are provided.
[0003]
However, an ink jet system that requires special paper has a problem in that the paper is limited and the cost of the paper is increased. Therefore, many attempts have been made to record on a sheet different from the dedicated sheet by the ink jet method. Specifically, a phase-change inkjet method using a wax ink that is solid at room temperature, a solvent-based inkjet method that uses a quick-drying organic solvent-based ink, or a UV inkjet method that records and then crosslinks with ultraviolet (UV) light. System.
[0004]
Above all, the UV inkjet system has attracted attention in recent years because it has a relatively low odor compared to the solvent-based inkjet system, and is capable of recording on a recording medium that is quick-drying and does not absorb ink.
[0005]
Here, a description will be given of a conventional example of an inkjet printer that performs printing on a sheet by ejecting ultraviolet curable ink onto the sheet P from an inkjet recording head. FIG. 6 is a perspective view showing the configuration of a conventional inkjet printer. As shown in FIG. 6, an ultraviolet irradiation device for irradiating ultraviolet rays is provided at a position where the ultraviolet curable ink ejected from the ink jet recording head 100 lands on the paper, and the ultraviolet irradiation device (also referred to as ink fixing means) is provided. An ultraviolet ray generating section 101 for generating ultraviolet rays, and an optical fiber 102 for guiding the ultraviolet rays generated from the generating section to near the vicinity of the ink jet recording head. An ink jet printer for curing is known (Patent Document 1).
[0006]
[Patent Document 1]
JP-A-2002-144553
[Problems to be solved by the invention]
However, the structure becomes complicated when the ink is guided to the ink jet recording head by an optical fiber from an ultraviolet irradiation device located at a position distant from the ink jet recording head. When an image is formed by jetting, there is a problem that it is difficult to obtain good image quality due to a change in the distance between the tip of the inkjet recording head and the surface of the paper.
[0008]
The present invention has been made in view of the above problems, and an object of the first invention is to provide an ink jet printer capable of ejecting ink on paper with a simple structure and fixing the ink to obtain a high image, It is another object of the present invention to provide an image forming method for an ink jet printer in which a high quality image can be obtained by ejecting ink onto paper and fixing the ink by a simple method.
[0009]
[Means for Solving the Problems]
The above object of the first invention can be achieved by the following means.
[0010]
(1) In an ink jet printer that forms an image by ejecting ink onto a sheet, a sheet holding drum unit that rotates a sheet holding drum on which the sheet is held on the outer peripheral surface and conveys the sheet, and a predetermined number of the sheet holding drum. Sheet holding means for holding the sheet at a position, image writing means for writing an image by ejecting ink from the ink jet recording head onto the sheet held on the sheet holding drum, and fixing the written ink on the sheet An ink jet printer, comprising: an ink fixing unit; and a sheet separating unit that separates the fixed sheet from the sheet holding drum, and forms an image on the sheet.
[0011]
The above object of the second invention can be achieved by the following means.
(2) In an image forming method of an ink jet printer for forming an image by ejecting ink onto a sheet, a first step of holding the sheet at a predetermined position on an outer peripheral surface of a sheet holding drum that rotates and conveys the sheet; A second step of writing an image on the sheet held by the holding drum with an ink jet recording head, a third step of fixing ink on the written sheet, and a fourth step of separating the fixed sheet from the sheet holding drum. Wherein an image is formed by sequentially performing the first to fourth steps by rotating the paper holding drum to form an image.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. FIG. 1 is a cross-sectional view illustrating an overall configuration of an ink jet printer according to an embodiment, and FIG. 2 is a cross-sectional view illustrating a configuration of an image forming unit in FIG.
[0013]
As shown in FIGS. 1 and 2, the ink jet printer has an automatic document feeder 1 on an upper portion of an ink jet printer main body (hereinafter, also simply referred to as a printer main body) and reads an image of an original in the ink jet printer main body. It comprises a unit 2, an image forming unit 3, a paper storage unit 4, a paper supply unit 5, a reverse discharge / re-feed unit 6, an ADU 8 serving as a reverse transport unit, a discharge tray 64, and the like.
[0014]
The automatic document feeder 1 is a device that feeds a document one sheet at a time, transports the document to an image reading position, and discharges the document, for which the document image has been read, to a predetermined place. The automatic document feeder 1 includes a document table 11 on which documents are placed, a document separating unit 12 for separating documents placed on the document table 11, and a plurality of documents for transporting the documents separated by the document separating unit 12. Document feeder 13 including rollers, document discharger 14 for discharging the document conveyed by document conveyer 13, document discharge table 15 on which the document discharged by document discharger 14 is placed, and And a document reversing means 16 comprising a pair of rollers for reversing the front and back of the document when reading images on both sides of the document. A plurality of documents (not shown) placed on the document table 11 are separated one by one by a document separating unit 12 and conveyed to an image reading position by a document conveying unit 13.
[0015]
The document reading position is provided below the document conveying means 13, where the image of the document is read through the slit 21. The document from which the image has been read is discharged onto the document discharge table 15 by the document discharge means 14. On the other hand, when reading images on both sides of the document, the document on which the image on one side has been read once is guided to the document reversing means 16, and the rollers are rotated reversely while the rear end of the document is applied to the rollers. The image on the other surface (second surface) can be read at the document reading position by turning over the document and transporting the document again by the document transporting unit 13.
[0016]
Such a process is repeated for the number of originals placed on the original placing table 11. The automatic document feeder 1 is configured to be foldable, and the automatic document feeder 1 is raised to open the document table glass 22 to directly place a document on the document table glass 22. It is configured so that it can be copied.
[0017]
The image reading means 2 is a means for reading an image of a document and obtaining image data, and includes a lamp 231 for irradiating the document via the slit 21 and a first mirror 232 for reflecting light reflected from the document. The first mirror unit 23, which is integrated, the second mirror unit 24, which integrates the second mirror 241 and the third mirror 242 that reflect the light from the first mirror 232, and the second mirror unit 24, An imaging lens 25 for forming an image of the reflected light on an image pickup device (hereinafter referred to as a CCD) 26, and a linear CCD 26 for photoelectrically converting the light image formed by the imaging lens 25 to obtain image information. have.
[0018]
Note that, in a mode in which the image reading unit 2 reads a document fed by the automatic document feeder 1, the first mirror unit 23 and the second mirror unit 24 are fixed at positions as illustrated. Further, in a mode of reading an image of a document directly placed on the platen glass 22, the first mirror unit 23 and the second mirror unit 24 are moved along the platen glass 22 while maintaining the optical path length. This is done by causing
[0019]
Further, the image processing means S performs image processing of the image data obtained by reading the image of the document so as to be optimal for forming an image with an ink jet printer. The image-processed data is compressed and temporarily stored in a memory.
[0020]
Further, in the paper storage unit 4, paper feed trays 400, 410, and 420 integrally configured with storage containers 405, 415, and 425 for storing paper in a stacked state and paper feed units 406, 416, and 426 are arranged vertically. The paper feed units 406, 416, and 426 have paper feed rollers 407, 417, and 427, and separation rollers 408, 418, and 428 for preventing stacking.
[0021]
The paper supply unit 5 includes a pair of transport rollers (hereinafter, simply referred to as “transport rollers”) R1, R2, R3, R4, and R5 as means for transporting the paper from each of the paper feed trays to the image forming unit 3. , R6. PS is a photo sensor, for example, a transport roller provided with paper fed from a paper feed tray 400 (410, 420) by a paper feed roller 407 (417, 427) downstream of a separation roller 408 (418, 428). It has a function of detecting whether or not the pair has reached the pair R1 (R2, R3), and is disposed at a position immediately before the transport roller pair R1. Reference numeral 55 denotes a transport roller provided downstream of the transport roller R4, which is provided at the junction of the transport path between the paper sent out via the ADU 8 and the paper fed from the paper feed tray 400, for example. And 57 are registration rollers.
[0022]
Further, the image forming unit 3 includes a sheet holding drum unit A that rotates the sheet holding drum 32 on which the sheet is held on the outer peripheral surface and conveys the sheet, and a sheet holding unit B that holds the sheet at a predetermined position of the sheet holding drum 32. Image writing means C for writing an image by ejecting ink from the ink jet recording head 31 to the paper held on the paper holding drum 32, ink fixing means D for fixing the ink of the written paper, and It has sheet separating means E and the like for separating from the holding drum 32, and forms an image by ejecting ink to the sheet.
[0023]
The sheet holding drum means A is adapted to hold the sheet P on the outer periphery of the sheet holding drum 32. When the motor M (see FIG. 2) rotates, the sheet holding drum means A rotates clockwise (in the direction of the arrow) in FIG. In conjunction with the rotation of the paper holding drum 32, operations such as holding the paper P on the paper holding drum 32, writing an image by jetting ink onto the paper P, fixing ink, and separating the paper P from the paper holding drum 32 are performed. Etc. are performed. Note that the entire peripheral length of the outer peripheral surface of the sheet holding drum 32 is larger than the entire length of the sheet P in the transport direction. In this embodiment, the length of the sheet holding drum 32 in the circumferential direction is A3 size. The length is 420 mm or more and 450 mm or less, which is a length that can cover a sheet of paper in the longitudinal direction.
[0024]
The sheet holding means B positions and holds the sheet P at a predetermined position on the outer peripheral surface of the sheet holding drum 32. The paper holding drum 32 is provided with a reference mark 322, while the inkjet printer body is provided with a reference index 323 for the paper holding drum 32. The initial position of the paper holding drum 32 is a position where the reference mark 322 and the reference index 323 match.
[0025]
More specifically, when the solenoid SOL1 is turned on, the swinging belt 39 stretched around the belt rollers 37, 38 is moved to a position indicated by a dotted line (see FIG. 2) with the rotation axis of the belt roller 37 as a fulcrum. Then, the swing belt 39 is rotated and pressed against the surface of the paper holding drum 32. When the sheet P is transported while the swing belt 39 is pressed against the surface of the sheet holding drum 32, the leading end of the sheet is sandwiched between the swing belt 39 and the sheet holding drum 32 and is transported in the direction of the arrow. When the solenoid SOL1 is turned off, the swing belt 39 is returned to the position indicated by the solid line by the bias of the spring 392, and is separated from the sheet holding drum 32.
[0026]
Further, the paper holding drum 32 is inserted and fixed to a hollow pipe shaft 343 whose one end is closed by a shielding cover (not shown). And is supported via a bearing (not shown) attached to the ink jet printer main body. The hollow portion of the paper holding drum 32 has a plurality of suction holes 321 formed in the outer peripheral surface. The pipe shaft 343 is connected to a suction fan (not shown), and when holding the sheet, the sheet P is sucked through the suction hole 323 and wound around the sheet holding drum 32 to be held.
[0027]
Further, the image writing unit C expands the image data stored by compression, and ejects ink onto a sheet based on the image-processed data to form an image. The ink jet recording head 31 is in contact with the outer peripheral surface of the paper holding drum 32 via a roller 311 that rotates along the outer peripheral surface of the paper holding drum 32 by the bias of the spring 312. In the embodiment, the distance between the tip of the ink jet recording head 31 and the outer peripheral surface of the paper holding drum 32 is set to 1 mm to 1.5 mm. Note that the inkjet recording head 31 may be brought into contact with the paper holding drum 32 via a roller along the surface of the paper held by the paper holding drum 32. The inkjet recording head 32 is provided with yellow (Y), magenta (M), cyan (C), and black (K) nozzles, respectively. The ink jet recording head 31 has a width capable of covering the paper width in the longitudinal direction. If the printing resolution is 600 dpi (dot / inch, but 1 inch is 2.54 cm) and the paper width is A3 size, image formation is performed. If the maximum size is possible, the number of nozzles of the inkjet recording head 31 is about 7196 dots (applicable width: about 304 mm). The circumference of the paper holding drum 32 is 420 mm or more.
[0028]
The ink to be used is a photo-curable ink, in addition to a pigment, for example, a monomer that is a precursor of a polymer compound, a photopolymerization initiator that promotes crosslinking and polymerization of the monomer by a photocatalytic reaction, a photopolymerization accelerator A photo-curable ink is used which has a property of being cross-linked and polymerized by irradiation of light such as ultraviolet rays to cure the monomer. For example, JP-B 5-54667, JP-A-6-200204, and JP-T-2000-504778 disclose ultraviolet-curable inkjet inks, but are not limited to ultraviolet-curable inks. An ink that cures may be used.
[0029]
Further, the ink fixing means D is means for fixing the ink by scanning and irradiating the surface of the paper on which the image is written with laser light. FIG. 3 is a diagram showing an optical system of the ink fixing means. As shown in FIG. 3, 351 is an ink curing light source, 352 is a polygon mirror, 353 is a slit of a light beam, 354 is an fθ lens, M1, M2, and M3 are reflection mirrors, 355 is a cylindrical lens, and 356 is a collimator lens. The light emitted from the ink curing light source 351 becomes parallel light by the collimator lens 356, is reflected and scanned by the rotating polygon mirror 352, is narrowed down to a predetermined spot by the slit 353, and is emitted by the fθ lens 354 in the main scanning direction. The light is corrected so as to have a uniform linear motion, and the optical path error due to the inclination of the polygon mirror 352 is corrected by the cylindrical lens 355 via the reflecting mirrors M1 and M2. The spot light is dropped on the image on the sheet P on the sheet holding drum 32 by the reflecting mirror M3, and the image is fixed by ultraviolet light. The light amount adjustment of the ink is performed in line units by the light amount monitor. That is, the spot-like light of the light beam by the slit 353 is adjusted to be vertically long, and the required amount of light is adjusted so as to irradiate the sheet. The light source in the wavelength region for curing the ink includes, for example, in the case of ultraviolet light in a specific wavelength region, an ultraviolet lamp that emits light with stable irradiation energy and a filter that transmits ultraviolet light of a specific wavelength as spot light and transmits the light. Is done. Here, as the ultraviolet light source, for example, a mercury lamp, a metal halide lamp, an excimer laser, an ultraviolet laser, a black light, an LED (light emitting diode) and the like can be applied. In particular, a black light having a wavelength of 250 nm is preferable because it can prevent bleeding and efficiently control the dot diameter.
[0030]
Further, the sheet separating means E separates the sheet P wound around the sheet holding drum 32 in FIG. When the solenoid SLO2 is turned on, the tip of the separation claw 36 comes into contact with the sheet holding drum 32. When the paper holding drum 32 holding the paper rotates clockwise (in the direction of the arrow) in a state where the separation claw 36 is in contact with the paper holding drum 32, the paper P is separated from the paper holding drum 32 by the leading end and separated. . When the separation of the sheet is completed, the solenoid SLO2 is turned off, and the separation claw 36 is returned to the original position (solid line) by the bias of the spring 361.
[0031]
Here, the main operation of the ink jet printer according to the embodiment will be described with reference to FIGS. FIG. 4 is an explanatory diagram showing each process of the ink jet printer. FIG. 4A illustrates a state in which the sheet holding drum is at an initial position where the reference mark 322 and the reference index 323 match, and FIG. 4B illustrates a state where the leading end of the sheet P is held by the sheet holding drum. FIG. 4C is a diagram showing a state where the leading edge of the sheet P is at a position where writing of an image is started, and FIG. 4D is a diagram showing a state where the leading edge of the sheet P is at a fixing position of ink. FIG. 4E illustrates a state in which the leading edge of the sheet is at a position where separation from the sheet holding drum starts. FIG. 5 is a time chart showing the operation steps of the ink jet printer. More specifically, the timing chart of each operation process of sheet holding, image writing, ink fixing, and sheet separation is schematically shown. In this embodiment, one sheet is performed by two rotations of the sheet holding drum. However, the present invention is not limited to this.
[0032]
The main operation of the ink jet printer will be described. First, as shown in FIG. 4A, a document is conveyed, image data is read, image processing is performed, the paper P is conveyed from the paper storage unit 4 and temporarily stopped by the registration rollers 57. Let it.
[0033]
As shown in FIG. 4B, the swing belt 39 rotates and moves to the position shown by the solid line, while the synchronization is performed so that the leading end of the paper P coincides with the reference mark 322 provided on the paper holding drum 32. Is taken. The sheet P is held on the sheet holding drum 32 from the leading end. Note that the swing belt 38 is controlled to return to the original position when the sheet is held (first step).
[0034]
As shown in FIG. 4C, the held paper P rotates clockwise together with the paper holding drum 32, and is synchronized with the ejection of the ink from the inkjet recording head 31, so that each of the Y, M, C, and K colors is obtained. The image is written correspondingly. That is, each color image processing signal is formed by the image-processed data, and the ink is ejected from the inkjet recording head 31 to perform the image writing according to the write command (second step).
[0035]
As shown in FIG. 4D, the ink is cured and fixed on the paper by the ultraviolet rays in the ink fixing means D (third step).
[0036]
As shown in FIG. 4E, the separation claw 36 comes into contact with the outer peripheral surface of the sheet holding drum 32, and the sheet P is separated from the sheet holding drum 32 (fourth step).
[0037]
As shown in FIG. 1, the separated sheet P is further conveyed, conveyed by conveying rollers 59, and sent to the reverse sheet discharging / re-feeding unit 6. The reverse discharge / re-feed unit 6 is an area for reversing and discharging the sheet after printing and fixing, or re-feeding the sheet in accordance with the duplex image forming mode. Is discharged to the outside of the apparatus as it is via the paper discharge roller 63, when the paper is discharged after being turned upside down, or when the paper is directed to the registration roller 57 in order to form an image on the back surface (second surface) of the paper. A switching unit 62 for switching the transport path when re-feeding is provided.
[0038]
When the sheet on which the image has been formed is to be discharged as it is, that is, with the image surface facing down, the switching means 62 is positioned at the position shown by the one-dot chain line in the figure, and the sheet on which the image is formed is turned upside down. In the case of discharging, the switching unit 62 is positioned at a position shown by a solid line in the figure, and the sheet conveyed by the reversing discharge roller 61 is fed into a conveying path provided with conveying rollers 600, 610, and 620, and the trailing end is fed. Stops the operation of the roller group at the timing when the roller group reaches the position in front of the conveying roller 600, and then rotates the conveying roller 600 in the reverse direction to pass the left side of the switching means 62. And discharges the paper to a paper discharge tray 64 outside the apparatus.
[0039]
Further, in the case of a mode in which an image is continuously formed on the second surface of the sheet, the switching unit 62 is positioned at a position indicated by a solid line in the drawing, and the sheet conveyed by the reverse discharge roller 61 is driven by the discharge motor. The sheet is fed to the ADU 8 via each of the transport rollers of the reversing sheet discharging / re-feeding unit 6, and after the sheet is turned over, is sent out to the registration roller 57, and is processed by the same process as the image formation described above. The sheet is discharged to the paper tray 64.
[0040]
As described above, the ADU 8 reverses the sheet and turns the sheet along the circulation path (registration roller 57-swing belt 39-reverse discharge / re-feed unit 6-ADU8-registration roller 57). This is a reversing conveyance unit that forms a part, and includes a plurality of roller pairs (hereinafter, also simply referred to as conveyance rollers) 800, 810, 820, 830, 840, and 850.
[0041]
Among the transport rollers, the roller denoted by reference numeral 800 is a roller that is driven and controlled in the forward and reverse directions by a motor (not shown), and is hereinafter referred to as an ADU reversing roller to distinguish it from the other rollers.
[0042]
The behavior of the sheet on which the image is to be formed on the second surface, particularly in the ADU, has advanced along the transport path by the driving action of the roller group (600, 610, 620) of the reversing sheet discharging / re-feeding unit 6. Thereafter, the movement of the ADU reversing roller 800 is continued in the same direction by the driving action of the ADU reversing roller 800, and the movement is performed in accordance with the rotation stop operation of the ADU reversing roller in a state where the rear end portion is sandwiched by the ADU reversing roller 800. Stops, and then switches back by receiving the driving force of the ADU reversing roller 800 rotated in the direction opposite to the rotation direction, enters the right conveyance path at a branch point, and conveys the conveyance rollers 810 or The horizontal movement path is moved to the right by the driving action of 850 and moves upward, and then reaches the registration roller 57 via the conveyance rollers 55 and 56. Thereafter, the sheet is processed by the same process as the above-described image formation, and then is discharged to the discharge tray 64.
[0043]
As described above, an image forming procedure such as sheet reversal and re-feeding (double-sided printing) is set by an operation panel as operation means.
[0044]
In the above embodiment, an example in which the image reading means 2 for reading a document is provided has been described. However, the present invention is not limited to this. For example, a document is read externally, and the image data is transferred to an inkjet printer. May be received to form an image.
[0045]
Further, in the above-described embodiment, as the holding of the sheet on the sheet holding drum 32, the suction by the suction fan (not shown) has been described. However, the present invention is not limited to this. For example, a charger and a static eliminator may be used. Alternatively, it may be performed by electrostatic adsorption.
[0046]
Further, in the above-described embodiment, the inkjet method using the ultraviolet curable ink has been described. However, the present invention is not limited to the ultraviolet curable ink, and an ink having a property of being cured by irradiation of infrared rays and visible light, and a light source suitable for the ink. May be used.
[0047]
【The invention's effect】
The configuration described above has the following effects.
[0048]
According to the first aspect of the present invention, since the sheet holding drum unit, the sheet holding unit, the image writing unit, the ink fixing unit, and the sheet separating unit are provided, the ink is ejected onto the sheet with a simple structure to discharge the ink. The ink jet printer was able to obtain a high image by fixing.
[0049]
According to the second aspect of the present invention, the paper is electrostatically attracted and held on the outer peripheral surface of the paper holding drum, or the paper is sucked and held through the suction hole provided on the outer peripheral surface of the paper holding drum. Further, the paper can be held on the paper holding drum with a simple mechanism and with high accuracy.
[0050]
According to the third aspect of the present invention, since the image is written by ejecting the photocurable ink onto the paper, the ink fixing process is facilitated.
[0051]
According to the fourth aspect of the present invention, since the inkjet recording head has a width that can cover the sheet width perpendicular to the sheet transport direction, the image is written over the entire area of the sheet width while the inkjet recording head is fixed. It became as to be.
[0052]
According to the fifth aspect of the invention, it is possible to form an image of a color including at least yellow (Y), magenta (M), and cyan (C).
[0053]
According to the invention described in claim 6, the urging member slidably abuts on the outer peripheral surface of the paper holding drum, and the interval between the tip of the ink jet recording head and the outer peripheral surface of the paper holding drum is maintained at a predetermined interval. Therefore, the accuracy of the interval can be easily obtained, and good image quality can be obtained.
[0054]
According to the seventh aspect of the present invention, since the surface of the paper on which the image is written is scanned and irradiated with the laser light to fix the ink, the ink can be reliably fixed with a simple structure.
[0055]
According to the eighth aspect of the present invention, since the outer peripheral length of the sheet holding drum is longer than the length in the sheet conveying direction, it is possible to form an image over the entire area in the sheet conveying direction.
[0056]
According to the ninth and tenth aspects of the present invention, since the sheet holding unit, the image writing unit, the ink fixing unit, and the sheet separating unit are arranged around the outer peripheral surface of the sheet holding drum, each unit is compact. , And the operation can be performed efficiently.
[0057]
According to the eleventh aspect, data obtained by reading a document can be subjected to image processing in the ink jet printer.
[0058]
According to the twelfth aspect, a document can be read in the ink jet printer.
[0059]
According to the thirteenth aspect, the image forming conditions can be set by the operation unit in the ink jet printer.
[0060]
According to the fourteenth aspect, an image is formed by sequentially performing the first to fourth steps by rotating the paper holding drum, so that the flow of each step is smooth and the drive control of the ink jet printer is easy. became.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an overall configuration of an inkjet printer according to an embodiment.
FIG. 2 is a cross-sectional view illustrating a configuration of an image forming unit in FIG.
FIG. 3 is a diagram illustrating an optical system of an ink fixing unit.
FIG. 4 is an explanatory diagram showing each process of the ink jet printer.
FIG. 5 is a time chart illustrating operation steps of the ink jet printer.
FIG. 6 is a perspective view illustrating a configuration of a conventional inkjet printer.
[Explanation of symbols]
A paper holding drum means B paper holding means C image writing means D ink fixing means E paper separating means 31 inkjet recording head 32 paper holding drum

Claims (14)

In an inkjet printer that forms an image by ejecting ink on paper,
Paper holding drum means for conveying the paper by rotating the paper holding drum on which the paper is held on the outer peripheral surface,
Sheet holding means for holding the sheet at a predetermined position of the sheet holding drum,
Image writing means for writing an image by ejecting ink from an ink jet recording head onto a sheet held by the sheet holding drum,
Ink fixing means for fixing the ink on the written paper,
Sheet separating means for separating the fixed sheet from the sheet holding drum;
An inkjet printer comprising: an image forming unit that forms an image on a sheet; The paper holding means holds the paper by electrostatically attracting and holding the paper to the outer peripheral surface of the paper holding drum, or sucks and holds the paper through a suction hole provided in the outer peripheral surface of the paper holding drum. The inkjet printer according to claim 1, wherein: The ink jet printer according to claim 1, wherein the image writing unit writes an image by ejecting a photocurable ink onto a sheet. 4. The ink jet printer according to claim 1, wherein the ink jet recording head has a width capable of covering a sheet width perpendicular to a sheet conveying direction. 5. The ink jet printer according to claim 1, wherein the image writing unit ejects ink of a color including at least yellow (Y), magenta (M), and cyan (C). 6. . At least a part of the image writing unit is slidably abutted on the outer peripheral surface of the paper holding drum by an urging member, and the interval between the tip of the ink jet recording head and the outer peripheral surface of the paper holding drum is set to a predetermined interval. The ink jet printer according to claim 1, wherein the ink jet printer is held. The ink jet printer according to claim 1, wherein the ink fixing unit scans and irradiates a surface of a sheet on which an image is written with a laser beam to fix the ink. The inkjet printer according to any one of claims 1 to 7, wherein an outer peripheral length of the paper holding drum is larger than a length in a paper transport direction. 9. The sheet holding unit, the image writing unit, the ink fixing unit, and the sheet separating unit, respectively, are arranged around an outer peripheral surface of the sheet holding drum. 2. The inkjet printer according to 1. 10. The ink jet printer according to claim 9, wherein the image writing unit, the ink fixing unit, and the sheet separating unit are arranged in this order in the rotation direction of the sheet holding drum. The inkjet printer according to any one of claims 1 to 10, further comprising image processing means for performing image processing of image data obtained by reading an image of a document into data to be image-formed by the inkjet printer. The inkjet printer according to claim 1, further comprising: a document reading unit configured to read image data from the document. The inkjet printer according to claim 1, further comprising an operation unit configured to set an image forming condition. In an image forming method of an ink jet printer for forming an image by ejecting ink on paper,
A first step of holding a sheet at a predetermined position on an outer peripheral surface of a sheet holding drum that rotates and conveys a sheet;
A second step of writing an image on a sheet held by the sheet holding drum with an inkjet recording head;
A third step of fixing the ink on the written paper;
A fourth step of separating the fixed sheet from the sheet holding drum;
An image forming method for an ink jet printer, comprising: sequentially performing the first to fourth steps by rotating the paper holding drum to form an image.

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