JP2006305877A - Recording apparatus and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a recording method which has less influence on a recording medium after an image is formed, and rapidly performs fixing by a simple structure and quickly causes a recording liquid delivered on the recording medium to quickly permeate the recording medium, and a recording apparatus. <P>SOLUTION: Permeation of an ink into the recording medium is accelerated by providing an ultrasonic wave generating apparatus as a drying means in the vicinity of the downstream side of a recording head in an inkjet recording apparatus, and applying a high frequency vibration by an ultrasonic wave on a paper just after the image is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a recording method capable of realizing high-speed fixing with respect to an image recorded at high speed by inkjet.

  Up to now, industrial printing machines have been mainly used for printed matter by analog such as manuals and catalogs, but in recent years, with the evolution of IT, the demand for variable data that creates contents according to the recipient is increasing.

  For this reason, in the industrial printing field, the production of various types and small lots has rapidly progressed from the mass printing up to now.

  Accordingly, there has been a demand for a printing press that does not require time and process before printing, and the need for a new printing method, print-on-demand, has increased. Print-on-demand technology has evolved due to growing needs, and high productivity, printing speed, image quality, and low cost are required.

  As a printing method that enables this new printing method, there is an ink jet recording method. The inkjet recording method is to create a recording image such as an image or a character by ejecting a small droplet of ink from a recording head and attaching it to a recording medium, and it is easy to make the recording apparatus compact, high-speed and color. A high-definition image can be obtained. In addition, the recording system has advantages such as a non-impact type, low noise during operation, and on-demand low running cost.

  From the above, the industrial printing market in the ink jet recording method has rapidly advanced. With changes in the market for inkjet printers, the target recording media have also changed.

  For this reason, it is required to produce a printed matter with high speed and high image quality even for printing paper that does not have the IJ fixing suitability. In the conventional ink jet recording method, an ink in which an aqueous pigment in which pigment particles are finely dispersed using various water-soluble dyes or water-soluble polymer resins as an ink is dissolved in a mixed solution with water or an organic solvent is used. Further, it is dried by utilizing the solvent permeability to the recording medium.

However, now that high speed printing is required, natural drying causes insufficient drying and causes show-through and tailing. Therefore, a drying apparatus such as a thermal energy or a high-frequency heating apparatus has been proposed for a post-processing unit that forms an image with a recording liquid on a recording medium in order to promote drying.
(For example, Patent Document 1 or Patent Document 2).

JP 11-207941

However, these apparatuses have drawbacks such as a complicated apparatus configuration and high power consumption because a heater or microwave is used for drying. Further, when the recording medium stops near the drying device due to paper jam or the like, excessive heat is applied to the recording medium, which is somewhat difficult from the viewpoint of safety.

  Accordingly, an object of the present invention is to provide a recording method in which the recording liquid ejected onto the recording medium has a simple mechanism and has a small influence on the recording medium after image formation, and quickly fixes the recording medium by quickly penetrating the recording medium. It is to propose a recording apparatus.

  The above object is achieved by the present invention described below. That is, in the present invention, immediately after the ink is ejected from the recording head, an ultrasonic wave is applied to quickly realize the penetration of the ink used for image recording into the paper.

In addition, the inkjet recording method of the present invention includes a recording head that records an image by discharging ink from a plurality of nozzles arranged perpendicular to a recording medium to be conveyed,
An ultrasonic wave is applied to the image portion from an ultrasonic wave generator arranged downstream in the transport direction from the recording head, and the ejected ink penetrates the recording medium.

  By carrying out the present invention, the ink fixing performance can be improved by allowing the ink used for recording to permeate the recording medium quickly.

  The ink jet recording unit can be applied to any method such as a charge amount control type, a continuous type using a spray method, a thermal ink jet method using heat energy, or a piezo method using a piezo diaphragm.

  At this time, the recording head may be a full multi-head having a recording width, or several heads may be arranged in the recording width direction, but if a higher speed is to be realized, a fixed line head should be used. Is preferred.

As a process of fixing the ink on the paper, first, there is a time when the ejected ink contacts the paper and no absorption occurs. This is called a wetting time and corresponds to the time until the surface of the paper gets wet with ink. Liquid penetration proceeds after the surface of the paper gets wet. There is the following Lucas-Washburn capillary penetration method as a basic theory related to liquid absorption and penetration.
h = (γcosθ · rt / 2η) ^1/2
(Where, h: depth of penetration, γ: surface tension of liquid, cos θ: contact angle between recording medium and recording liquid, r: capillary radius, t: penetration time, η: viscosity of liquid)
From this equation, when the contact angle (cos θ) of the recording liquid is small, the wetting property of the recording liquid is improved, so that the penetration of the recording liquid is promoted.

  The present invention includes an ultrasonic generator, and by applying ultrasonic vibration after ejecting ink, the contact angle between the paper and the ink is reduced, and the wetting time is reduced. If the wetting time is short, it is possible to allow the ink to permeate quickly, and beading that occurs before permeation hardly occurs. In addition, since the liquid has better ultrasonic transmission than air, the influence of ultrasonic waves increases as the ink penetrates the paper, and the penetration is promoted.

  In addition, when the ultrasonic generator is disposed on the back side of the recording surface, the sheet is subjected to high-frequency vibrations and an operation such as passing through a sieve occurs, so that the ink penetrates smoothly into the sheet. In addition, by providing a sensor in the recording device and sensing the thickness of the recording medium and the discharge amount of the recording liquid, the ultrasonic oscillation frequency, ultrasonic intensity, and application time are controlled according to the thickness and discharge amount of the recording medium. , The degree of penetration can be adjusted.

  Since the ultrasonic oscillation frequency can be controlled, a recording medium having penetrability can be dried at high speed even on a recording medium having various penetrating characteristics (a recording medium that does not easily penetrate). It is also possible to manually perform high-speed drying suitable for the recording medium by controlling the oscillation frequency of the ultrasonic wave according to the thickness and type of the recording medium.

  The controllable ultrasonic oscillation frequency is preferably in the range of 1 to 30 [MHz]. The liquid composition used in the present invention is composed of a coloring material and water, but in addition to this, a surfactant, preservative, antioxidant, and other organic solvents for adjusting physical properties can be added.

  The surfactant is added for the purpose of improving the permeability to the recording medium, smoothing with the ejection device member, flow characteristics, and an auxiliary agent for dispersion stability. The color material used in the ink may be pigment ink, dye ink, or a mixed ink thereof, but is preferably a pigment in terms of light resistance and water resistance. The pigment is not particularly limited, and both inorganic pigments and organic pigments can be used.

  The amount of the color material contained in the ink to be used is preferably 1 to 20% by weight, and preferably 2 to 12%.

  In the embodiment of the present invention, an ink jet recording apparatus equipped with the dryer of the present invention will be described in detail with reference to the following drawings for explaining examples relating to the recording apparatus of the present invention. However, the present invention is not limited to these examples.

  An ink jet recording apparatus equipped with the ultrasonic generator of the present invention will be described with reference to FIG.

  The recording apparatus 101 includes five recording head modules 103 to 107 on a media stage 117. The recording data to each recording head module is created by the information processing apparatus 100 and transferred to the recording apparatus 101 via the USB interface and the USB cable 120.

  Each of the recording head modules 103 to 107 is composed of a total of four color recording heads K (black), C (cyan), M (magenta), and Y (yellow), and each recording head has a corresponding ink tank 111 to 114. Ink is supplied through the tube 115.

  The recording resolution of each recording head is, for example, 600 [dpi], the number of nozzles ejecting ink is 2,560 [Nozzle], and thus the maximum recording width is about 4.3 [inch]. Since an overlap area is required, the line printer is capable of continuously performing color recording of a maximum recording width of 20 [inch] with a recording width of 4 [inch] per recording module. [Dpi] indicates [dot / inch].

  The paper (recording medium) 102 is transported in the direction of the arrow by a transport motor 118 and is recorded at a high speed simultaneously with the passage of the recording head modules 103 to 107 below. An ultrasonic generator 109 is disposed below the paper 102 further downstream of the recording head modules 103, 105, and 107 on the downstream side in the transport direction, and a paper discharge roller 108 is further downstream.

  FIG. 2 shows this embodiment. Two ultrasonic generators 109 are arranged in cascade in the transport direction further downstream of the recording head modules 103, 105, and 107 on the downstream side. This is to ensure the permeability of the ink by ultrasonic vibration and can be said to be an effective means when continuous recording at higher speed is required.

Details of the ultrasonic generator 109 are shown in FIG. The main body of the ultrasonic generator 109 is provided with a vibrator 301 such as a piezo to vibrate the vibration roller 302 and the vibration belt 303 as a whole. The vibration frequency is preferably in the range of 1 to 30 [MHz], for example.
In order to reduce the amount of ultrasonic attenuation at the contact portion between the vibration belt 303 and the paper 102, forward tension is applied to the paper 102 by the paper discharge roller 108 that tries to rotate at a faster peripheral speed than the conveyance roller (not shown in FIG. 3a). And is in close contact with the vibration belt 303.

  In FIG. 3 b, the paper 102 is also brought into close contact with the vibration belt 303 by applying a forward tension within a predetermined range to the paper 102 by the take-up torque of the paper take-up rewinder 304.

3A and FIG. 3B, a forward tension is applied from the rewinder 304 to the paper 102, but the initiative to determine the conveyance speed is only held by the conveyance roller coupled to the upstream conveyance motor 118.
In this embodiment, the ultrasonic generator 109 is arranged on the back side of the paper 102. However, when the ultrasonic generator 109 is arranged on the recording surface side of the paper 102, it is arranged so as to be physically non-contacting. Consideration is required.

  FIG. 4 shows a connection form between the host PC 100 that performs image data creation, transfer, and issue of a recording operation start command, the recording apparatus 101, and the conveying apparatus 401 and the ultrasonic generator 109. For example, USB is used as an interface between the host PC 100, the recording apparatus 101, and the transport apparatus 401. However, the ultrasonic generator 109 may be controlled directly from the host PC 100 through the USB interface.

  FIG. 5 is an electrical block diagram of the conveying device 401 that handles the paper 102.

  A conveyance start / stop command of the paper 102 is received from the host PC 100 via the USB interface controller 501, and the CPU 502 analyzes the command.

  When a transfer start command is received, a transfer speed instruction value or the like is written in the servo logic 508, and an operation start is instructed. Subsequently, the conveyance motor 118 is started through the servo amplifier 509 to start a constant speed conveyance of an instruction speed value, for example, 200 [mm / sec].

  The speed control is performed by the servo logic 508 itself by feeding back the output of the rotary encoder 510 coupled to the rotating shaft 118 of the transport motor to the servo logic 508.

  Thereafter, the paper 102 arrives at the transport unit from a roll paper supply unit (not shown), and when the leading edge is detected by the paper leading edge detection sensor 506, the servo logic 508 starts sending a count Up signal and a position pulse. The count Up / Down signal and the position pulse are obtained by synchronizing and converting the output of the encoder 510. For example, the position pulse is output 600 [Pulse] when the recording medium 102 advances 1 [inch] in the same manner as the resolution of the recording head. . The count Up / Down signal is kept at “High” while the paper 102 is being conveyed in the forward direction, and kept at “Low” level in the reverse direction (back feed). The count Up signal and the position pulse signal are also used as a real time cutout signal of the recording apparatus 101.

  The operation panel 505 has a display such as an LCD and operation keys, and can manually turn on / off the power, start / stop operation, and monitor the operation status of the apparatus.

  Reference numeral 507 denotes an input / output port, and the CPU 502 can monitor and control peripheral circuits via these ports.

  The control program of the CPU 502 is stored in the ROM 503, and the RAM 504 is used as a work memory necessary for each process.

  An interface 511 is a communication interface with the printing apparatus 101, and transmits / receives mutual status, and automatically switches a printing speed (conveyance speed).

  Since the sheet 102 is large, it is conceivable to use a sheet adsorbing unit (not shown). The ultrasonic generator 109, which is a characteristic part of the present invention, can be turned ON / OFF via the input / output port 507, but the drive source of the vibrator itself may include an individual power supply device. Since the rewinder 304 added to the paper discharge side has a motor, the control is preferably performed by the CPU 502 of the transport device 401 in relation to the transport motor 118.

  FIG. 6 is an electrical block diagram of the recording apparatus 101.

  Image recording data, a recording start / stop command, and the like are received from the host PC 100 via, for example, the USB interface controller 601, and the CPU 602 analyzes the command.

  When a recording operation start command is received, recording data is stored in the VRAM 607 at high speed via the interface controller 601 and the memory controller 606 according to an instruction from the CPU 602. In the recording apparatus according to the present invention, the amount of recording data transferred from the host PC always exceeds the amount of recording data recorded per unit time.

  An execution program of the CPU 602 and various conversion tables are stored in the ROM 603. A RAM 604 is used as a working memory. Information unique to the recording apparatus 101, such as information on all the recording heads of the recording modules 103 to 107 and adjustment data (registration) of minute recording positions in the vertical and horizontal directions, is written in a nonvolatile EEPROM 605. Can be changed.

  When a predetermined amount of recording data can be received, a head U / D motor 611 that moves all the recording heads up and down all at once and a cap motor 612 that moves a cap mechanism (not shown) to the left and right in the transport direction are mutually connected via a drive unit 610. Then, all the recording heads of the recording modules 103 to 107 are simultaneously moved from the standby position to the recording position to prepare for recording.

  The pump motor 613 supplies ink from an ink tank (not shown) to the recording heads of the recording modules 103 to 107, and pressurizes the ink in the recording head when ink is not ejected from the nozzles for a predetermined period. It is also used as a drive source for a pressure pump (not shown) for forcibly discharging ink from each nozzle to restore sound recording performance.

  When reception of the count up signal and position pulse from the transport device starts, the latest current position of the recording medium (paper) 102 is indicated by the UP / Down counter included in the recording module control circuit 608. When the recording medium reaches the recording start position of each recording module, the recording data is transferred to each of the recording modules 103 to 107 via the VRAM 607 to the memory controller 606 to the recording module control circuit 608 at high speed. The VRAM 607 is configured in a FIFO (First In First Out) format, and is refreshed to new received data in order from the recorded area.

  The recording apparatus 101 shown in FIG. 1 includes a set of recording head modules 103 to 107. However, if the recording operation is continued even if a recording head cleaning (recovery) operation is performed during the recording operation, recording is performed. If a plurality of sets of head modules 103 to 107 are used, continuous recording can be maintained.

  The operation panel 620 includes operation keys such as power ON / OFF and forced stop. Reference numeral 621 denotes a temperature sensor inside the recording module. Besides this, a sensor (not shown) is also present in the recording module. The input / output port 609 is used for input identification of sensors, operation keys, etc., and control of ON / OFF of actuators such as motors.

  The interface 625 is used as an interface when another recording apparatus 101 is added in the recording width direction and the maximum recording width is doubled to 40 [inch]. Reference numeral 626 denotes a communication interface with the transport apparatus 401, which exchanges commands for obtaining synchronization between the recording operation and the transport apparatus 401 including the ultrasonic generator.

  Each of the recording head modules 103 to 107 may include a sub CPU separately to reduce the load on the CPU 602.

  Next, operations among the host PC 100, the recording apparatus 101, and the transport apparatus 401 will be described with reference to an operation flow of FIG.

  When printing start is input on the screen of the host PC 100, a conveyance start command is issued (701), and the conveyance device starts driving the conveyance motor (721). The vibration roller 302 and the vibration belt of the ultrasonic generator 109 arranged on the downstream side of the recording head modules 103 to 107 are also moved by the conveyance motor, but the upstream conveyance roller 110 has the initiative of the sheet conveyance speed. Holding

  Next, the recording data is created and transferred (702), and the recording apparatus moves the recording head from the standby (capping) position to the recording position (741).

  When the leading edge of the paper 102 is detected by the leading edge detection sensor 506 (722-Yes) in the transport device, output of a print start signal (count up signal, position pulse) is started (723), and recording by each recording unit is performed. Operation begins (742).

  In parallel, when the operation of the ultrasonic transducer 301 of the ultrasonic generator 109 is turned ON (724), an ultrasonic signal is applied to the paper 102 via the vibration roller 302 and the vibration belt 303. As shown in the second embodiment of FIG. 2, the ultrasonic generators 109 may be arranged in cascade in the transport direction. Thereafter, the ink permeability to the paper 102 is improved and the scratching property is improved.

  When the desired recording operation is finished (743-Yes), the recording head returns to the standby position (744), and when the paper 102 is discharged (725-Yes), the transport device 401 completes the operation to the host PC. Then, the ultrasonic generator 109 is turned off, the conveyance motor is also stopped (727), and the process ends.

  The present invention can be used in a recording system that records high-quality images at high speed and discharges them with high reliability.

It is a schematic image figure for demonstrating 1st Example of this invention. It is a schematic image figure for demonstrating 2nd Example of this invention. It is a figure explaining incorporation of an ultrasonic generator. It is a system configuration diagram of the present invention. FIG. 4 is an electrical block diagram of a paper transport device. It is an electrical block diagram of a recording apparatus. It is a processing flow explaining the operation | movement sequence of each apparatus.

Explanation of symbols

100 Information processing device (host PC)
101 Recording device 102 Paper (recording medium)
103-107
Recording head module 108 Paper discharge roller 109 Ultrasonic generator 110 Conveying roller 118 Conveying motor

301 Ultrasonic vibrator 302 Excitation roller 303 Excitation belt 304 Rewinder

401 Conveying device

502 CPU (conveying device)
602 CPU (recording device)

Claims (8)

In a recording apparatus for recording an image by ejecting ink onto a recording medium from a recording head having a plurality of nozzles,
A recording apparatus comprising an ultrasonic generator in the vicinity of the recording head, which can permeate the ejected ink into the recording medium by vibration.   2. The recording apparatus according to claim 1, wherein the ultrasonic generator is disposed downstream of the recording head in the recording medium conveyance direction.   The recording apparatus according to claim 1, wherein the ultrasonic generator is disposed on a back surface with respect to a recording surface of the recording medium.   3. The recording apparatus according to claim 1, wherein the ultrasonic generator is disposed on a recording surface of the recording medium.   The recording apparatus according to claim 1, comprising a plurality of the ultrasonic generators.   The recording apparatus according to claim 1, wherein a generation frequency of the ultrasonic generator is 1 to 30 MHz.   The recording apparatus according to claim 1, further comprising a thermal energy generation device on a downstream side of the ultrasonic generation device. A recording medium transported on a transport path, and disposed perpendicular to the recording medium transport direction,
A recording head for recording an image by ejecting ink from a plurality of nozzles in a stationary state;
A recording method comprising irradiating the image with ultrasonic waves from an ultrasonic generator disposed downstream in the transport direction from the recording head and penetrating the image into the recording medium.

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