JP2006321065A - Inkjet recorder, recording medium for the apparatus, and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate printing to a recording medium such as a corrugated cardboard by an optimum condition according to contents of an image to be recorded, by applying an inkjet recording system. <P>SOLUTION: A cardboard box 11 is equipped with a storage element 17 beforehand. Recording control information, printing data and the like are stored in the element. Printing is carried out while a first recording head 1 for recording large dots and a second recording head 2 for recording small dots are suitably selected on the basis of the information, data and the like. In other words, a solid recording part such as a logo, and an elaborate recording part such as a bar code are distinguished from each other on the basis of the stored information. Printing is carried out by selecting the recording head favorable for each of the parts. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus, a recording medium for the apparatus, and an ink jet recording method, and is particularly carried out at a site such as a manufacturing factory, a site where goods are stored and shipped such as a distribution warehouse, or a cardboard liner paper printing site. It is suitable for application to corrugated cardboard printing.

  As a method for printing on a corrugated cardboard box for distribution of fruit and vegetable products, marine products, machine parts, etc., as described in Patent Document 1, there is a method using a flexographic printing method or the like on a sheet-like cardboard box material. Are known. At this time, information such as the name of the contents to be stored in the cardboard box, common information such as the design part, manufacturer name, etc. is printed in advance (pre-printing), and then this is cut, and further the cardboard box making machine Etc. can be processed into a box. In addition, unique information such as serial numbers, product destinations, and lot numbers are formed by printing with a stamp or printer after boxing, or by attaching a label on which the unique information is printed. .

  However, as the type of contents to be stored in the cardboard box increases, the number of pre-printed sheet-like materials, cut cardboard paper, or cardboard boxes to be boxed increases. Therefore, a space for storing them before use is required, and management becomes complicated. Furthermore, when the common information to be pre-printed is changed, it is necessary to change the plate, resulting in problems such as being unable to respond quickly.

  Also, for forming unique information, when a stamp is used, the machine cost is low, but it requires work and is expensive. In addition, when printing with a stamp or a printer, the corrugated cardboard to be printed is not rigid in the thickness direction, and printing unevenness is likely to occur. Invited to rise. In addition, when printing specific information on a label and pasting it on cardboard etc., there is no need to prepare a separate output machine for printing on the label or a system for peeling the liner carrying the label and pasting it on the box And the cost of the label itself. In addition, since a large amount of liners and the like that are no longer necessary after label separation are generated, it is not preferable in terms of environmental performance and resource saving.

  Therefore, it is conceivable to solve the above-mentioned problem by simultaneously printing the common information and the specific information directly on the liner paper on the outer surface of the cardboard using an ink jet recording method. Here, the ink jet recording system is a system in which ink is ejected from an ink ejection port provided in a recording head and desired information is formed on various recording media, and recording is performed in a non-contact manner on the recording medium. Therefore, it has advantages such as high-quality images with no unevenness and good water resistance, high-speed recording, and easy colorization. is there. This eliminates the need to have pre-printed cardboard boxes in stock even when a wide variety of cardboards are required, which not only saves space in warehouses and factories, but also responds quickly to design changes. it can. Further, since it is not necessary to prepare or replace a plate at the printing site, the cleaning process can be reduced and ink can be used efficiently.

  However, when printing on a cardboard liner paper by the inkjet recording method, it is difficult to achieve both printing with a design portion, a portion with a so-called “solid” portion such as a logo mark, and a dense portion such as a barcode or character. There's a problem. This is because the surface of cardboard liner paper is generally processed so that flexographic ink can be easily applied, so when printed with low-viscosity ink, the characters and barcodes are relatively dense due to bleeding. This is thought to be due to the marked deterioration in the print quality at such parts. In addition, when ink with suppressed bleeding is used, the print quality of relatively dense parts is improved, but there is no bleeding in areas where solid printing is performed, so there are areas that are not covered with ink, such as white lines. The problem that it occurs occurs.

  Here, Patent Document 2 discloses an image recording apparatus that includes a recording head that discharges pigment ink and a recording head that discharges dye ink, and switches the use of them depending on whether they are characters or non-characters. ing.

Japanese Patent Laid-Open No. 5-92554 JP 2005-1250 A

  The configuration described in Patent Document 2 is effective for recording on a recording medium of a relatively small size that is to be recorded by an office or personal use recording apparatus. However, when recording on a relatively large recording medium, such as recording on corrugated paper, simply separate characters and non-characters and switch between pigment ink and dye ink. Is not enough. For example, even if it is a character, it may be a large point where the solid portion becomes large, and even if it is a non-character, there are some that should be formed densely like a barcode.

  Therefore, the present invention makes it possible to perform preferable recording for each portion of an image to be formed, that is, recording with high reliability and good quality, on a relatively large recording medium such as corrugated paper. It is for the purpose.

  Another object of the present invention is to make it possible to easily realize preferable recording for each portion of an image to be formed.

  For this purpose, the present invention uses a first recording head for recording a recording dot having a relatively large area and a second recording head for recording a recording dot having a relatively small area. An ink jet recording apparatus for printing on a cardboard liner paper, etc., which should be recorded by the first recording head on the basis of the reading means for reading information for printing from the recording medium and the read information Identification means for identifying a portion (solid recording portion, etc.) and a portion (dense recording portion, etc.) to be recorded by the second recording head, and driving the first and second recording heads based on the identification And means for performing a recording operation.

  In addition, the present invention is a recording medium that can be printed by the ink jet recording apparatus, and is characterized by carrying information holding means that can be read by the reading means.

  Furthermore, the present invention prints on a recording medium using a first recording head for recording a recording dot having a relatively large area and a second recording head for recording a recording dot having a relatively small area. A step of reading information for printing from an information holding means carried on the recording medium, and a portion to be recorded by the first recording head based on the read information And a step of identifying the portion to be recorded by the second recording head, and a step of driving the first and second recording heads based on the identification to perform a recording operation. And

  According to the present invention, an information holding unit is provided on a recording medium, recording control information, print data, and the like are stored, and recording is performed while an appropriate recording head is selected based on the recording control information and print data. Printing can be easily performed under the optimum conditions according to the contents.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

1. 1. First Embodiment 1.1 Inkjet Recording Apparatus FIGS. 1 and 2 are a schematic side view and a schematic perspective view, respectively, of an inkjet recording apparatus (hereinafter simply referred to as a recording apparatus) according to a first embodiment of the present invention. FIG.

  The recording apparatus of this example includes an endless conveyor belt 14 that is stretched between a pair of drums 13 and 13 disposed on the upstream side and the downstream side in the medium conveyance direction F with respect to the printing position, and recording is performed on the conveyance belt 14. While carrying the corrugated cardboard box 11 as an object, the conveyance is performed by running the conveyance belt accompanying the rotation of the drum. 1 to 5 are full line heads in which discharge ports are arranged in a direction perpendicular to the transport direction F over the entire width of the cardboard box 11 in order to perform recording on the transported cardboard box 11. An ink jet recording head (hereinafter simply referred to as a recording head), which is juxtaposed along the transport direction F. The recording heads 1 and 2 eject black ink, and the recording heads 3, 4 and 5 eject cyan, magenta and yellow inks, respectively.

  Here, in this embodiment, the recording head 1 is suitable for recording a so-called solid portion by forming a large area dot on the recording surface of the cardboard box 11. On the other hand, the recording head 2 is suitable for recording a dense portion by forming small area dots.

  The recording heads 1 to 5 are supplied with ink of a corresponding color from an ink supply source (not shown) through a tube or the like. Further, as the recording heads 1 to 5, for example, a recording head having an element that generates thermal energy that causes film boiling in the ink can be used as energy used for ejecting the ink. Furthermore, as a configuration that enables recording over a length corresponding to the maximum width of the recording medium, each recording head may satisfy the length as shown in the drawing, The structure which satisfy | fills length may be sufficient.

  A non-contact communication unit 15 including an RF-ID communication antenna is provided at a position upstream of the recording heads 1 to 5 in the conveyance direction of the cardboard box 11. Prior to recording by the recording heads 1 to 5, communication is performed with a non-contact integrated circuit board (RF tag or the like) 17 having a data storage function and a non-contact communication function attached to the cardboard box 11. Based on the information acquired from the contact integrated circuit 17 via the non-contact communication unit 15, it is possible to execute predetermined printing on the cardboard box 11. That is, the cardboard box 11 is transported by the transport belt 14, and after the information held by the non-contact integrated circuit board 17 is first read by the non-contact communication unit 15, it passes through the recording position by the recording heads 1-5. Recording (one-pass recording) is performed with each color ink ejected from each head, and the ink is discharged out of the recording apparatus.

  The non-contact integrated circuit board 17 can store control information such as the material of the recording medium and printing data (including color designation), for example. It is also possible to store identification information for the solid recording portion and the dense recording portion included in the printing data. In particular, since the type of the surface coat layer differs depending on the application, storing the control information in advance such that the recording device can print each image to be printed on the used cardboard box. It is possible to easily realize preferable recording for the portion.

  In addition, a barcode (including a two-dimensional barcode) is printed in advance on the cardboard box 11, and a predetermined barcode reader is placed upstream of the recording heads 1 to 5 in the transport direction of the cardboard box 11. It is also possible to execute predetermined printing on the cardboard box 11 based on information obtained from the barcode prior to recording by the recording heads 1 to 5.

FIG. 3 is a block diagram illustrating a configuration example of a control system of the recording apparatus 101 according to the present embodiment.
Here, the MPU 600 executes a control program corresponding to a control procedure described later with reference to FIG. 4 stored in the program ROM 601 while appropriately using the work RAM 602. Reference numeral 603 denotes a VRAM that functions as a print buffer that develops print data for each print head corresponding to print data in the cardboard box 11.

  Reference numeral 604 denotes a communication control driver for exchanging information with the host device 109 such as a computer. Reference numeral 313 denotes a conveyance motor which is a driving source for conveyance of the cardboard box 11, and 605 denotes a driver thereof. Reference numeral 606 denotes a driving circuit that drives the recording heads 1 to 5 for each color based on the recording data developed in the VRAM 603. 309 is a sensor for detecting the tip position of the cardboard box 11 being conveyed, 105 is a power switch of the recording apparatus, 610 is an operation switch for an operator to set an operating environment, and 607 is for these parts. Input / output unit (I / O). Reference numeral 611 denotes a display unit in the form of an LCD for displaying a required message to the operator, and reference numeral 608 denotes a driver for driving the LCD 611.

  FIG. 4 is a flowchart showing a recording processing procedure by the recording apparatus of this embodiment.

  This procedure is started, for example, when a recording start command is received from the host device 109. First, the conveyance motor 313 is operated to drive the conveyance belt 14, and conveyance of the corrugated cardboard 11, which is a recording medium, is started (step S1). ). When communication with the RF-ID tag 17 becomes possible, the stored information is read through the non-contact communication unit 15 (step S3). From the printing data included in the read information, especially for data using black ink, a solid recording part (logo, design part, large point character, etc.) and a precise recording part (barcode ( The data to be recorded by each color recording head is developed in the VRAM 603 (step S7).

  Then, a recording operation is performed on the conveyed cardboard box 11 while driving the recording heads 1 to 5 based on the recording data (step S9). When recording on one cardboard box 11 is completed, it is determined whether or not recording is to be performed on the next cardboard box 11 (step S11). If the determination is affirmative, the processing from step S3 is repeated. If the determination is negative, after the cardboard box 11 is discharged, the transport operation is stopped (step S13), and this procedure ends.

  The solid recording portion and the dense recording portion can be identified as long as the RF-ID tag 17 attached to the cardboard box 11 holds the identification information in advance. Further, if the non-contact integrated circuit board 17 holds recording data for each recording head in advance as print data, it can be developed into the VRAM 603 using this as it is.

  On the other hand, if the identification information is not held in the RF-ID tag 17, for example, if it is held as black print data, the distribution state of the black print data is determined, and the solid recording is performed. The development may be performed by separating into a preferable portion and a portion where fine recording is preferable. Further, if the RF-ID tag 17 holds print data as a color image, separation into each color recording data, and further separation of black data into a portion where solid recording is preferable and a portion where fine recording is preferable. Just do it. If the burden on the recording apparatus is large in performing these separation processes, it can be received after the separation process is performed on the host apparatus 109 side. In this case, the data stored in the RF-ID tag 17 may be transferred from the recording device to the host device 109, or may be directly transmitted from the non-contact communication unit to the host device 109.

  Further, in the above procedure, if it takes time from data communication to data development after communication with the RF-ID tag 17, the conveyance can be stopped before the recording process (step S9).

  Further, in the above configuration, the RF-ID tag 17 may be attached to each recording medium (corrugated cardboard box), or may be attached to a plurality of sheets or a lot unit. In this case, the number of recordings (the number of cardboard boxes) can be stored in the RF-ID tag 17 attached to the leading recording medium.

  As a basic configuration, the present embodiment employs an ink jet recording system that performs printing with high quality and good water resistance on a cardboard box (or on the inner / outer liner paper). This eliminates the need to have pre-printed cardboard boxes in stock even when a wide variety of cardboards are required, which not only saves space in warehouses and factories, but also responds quickly to design changes. it can. In addition, since it is not necessary to prepare or replace a plate at the printing site, the cleaning process can be reduced and ink can be used efficiently.

  In addition, the present embodiment has a characteristic configuration in which a cardboard box is provided with a storage element in advance, recording control information, print data, and the like are stored, and recording is performed while appropriately selecting a recording head based on this. Thus, it is possible to perform printing under preferable and optimal conditions according to the content of the image to be recorded and further according to the type of liner of the cardboard.

1.2 Embodiment for Obtaining Different Recording Dot Areas The present invention provides a first recording head for forming a relatively large recording dot and a second recording dot for forming a relatively small recording dot. A recording head is used, and a portion to be recorded by both recording heads is separated according to the contents of an image to be recorded.

  In order to obtain different recording dot areas as described above, various modes can be exemplified.

  In the above-described recording apparatus, the size of the ejection ports of the recording heads 1 and 2 is made different (for example, the recording head 1 has a larger array of ejection ports than the recording head 2), thereby different recording dots. The area can be obtained.

  Further, in the recording heads 1 and 2, different recording dot areas can be obtained by using inks having different bleeding rates on the recording medium. Then, a portion with a large solid area such as an illustration or a logo is recorded with ink having a high bleeding rate, and a portion requiring precise printing such as a small-point character or barcode is recorded with a low bleeding rate ink. it can.

  The bleeding rate is obtained by dividing the dot diameter on the recording medium by the diameter of the ink droplet calculated from the volume of the ink drop ejected from the recording head, and an appropriate bleeding rate is obtained according to the resolution. Such a bleeding rate is influenced by the surface condition of the recording medium, but can be controlled by the surface tension or viscosity of the ink.

  Here, it is preferable to use a pigment or a dye as the color material used in the black ink. The amount of the coloring material contained is in the range of 0.5 to 20%, preferably 2 to 12% by weight. When a pigment is used as the color material, carbon black can be used. When a dye is used as the color material, an acid dye, a direct dye, a reactive dye, or a basic dye described in the color index can be used. However, these are examples, and a newly synthesized one can also be used.

  In addition to the above coloring materials, surfactants (nonionic surfactants, amphoteric surfactants, cationic surfactants, etc.), preservatives, antioxidants, etc. as auxiliary agents for ejection stability, flow characteristics, and dispersion stability An auxiliary material for adjusting physical properties can be added, and an ink is prepared by applying a water-soluble solvent thereto. The surface tension and viscosity of the ink can be adjusted arbitrarily depending on the type of surfactant, the amount added, the type of water-soluble solvent, and the amount added.

  Alternatively, even if the recording heads 1 and 2 have an array of ejection openings of the same size, the ink ejection amount is varied by changing the driving conditions of the recording head, thereby varying the recording dot area. It is also possible to

  For example, in a recording head using a heating element (heater) that generates thermal energy that causes film boiling in ink as a result of energization as energy used to eject ink from an ejection port, Driving conditions can be varied. In other words, the drive pulse (heat pulse) supplied to the heater is a single pulse (single pulse), and is divided into two pulses before and after the interval time (pause period) (double pulse including pre-pulse and main pulse) The discharge amount can be modulated by appropriately modulating these divided pulses and interval time.

  In addition, whether driving with a single pulse or driving with a double pulse, the discharge amount can be controlled by controlling at least one of the pulse height (applied voltage), pulse width, and pulse shape. It is also possible to control. Furthermore, it is possible to control the ejection amount by adjusting the ink viscosity by providing a temperature adjusting heater in the recording head and appropriately heating the ink in the recording head. Further, it is possible to adopt a configuration in which two or more discharge heaters are provided corresponding to one discharge port, and discharge amount modulation is enabled by selectively driving the discharge heaters. That is, “different drive conditions” as used in the present invention includes such aspects.

1.3 Examples Hereinafter, specific examples applied to the configuration of the recording apparatus of FIG. 1 will be described.

1.3.1 Ink First, the following various black inks were prepared.

Black ink A
80 parts potassium hydroxide solution (neutralization rate 110%, resin solid content 15 parts) of styrene / acrylic acid / ethyl acrylate copolymer (acid value 200, weight average molecular weight 15000), 7 parts ethylene glycol, this solution After adding 13 parts of carbon black (MA-7; manufactured by Mitsubishi Chemical Corporation), the mixture was dispersed using a sand mill to prepare an aqueous dispersion (solid content: about 12%).

Next, the following components were mixed, stirred for 3 hours, and then filtered through a 1 μm membrane filter to obtain black ink A.
-25 parts of the above dispersion-15 parts of ethylene glycol-5 parts of glycerin-5 parts of triethylene glycol-0.5 part of Emulgen 931-remaining part of the ion-exchange water The surface tension of this ink is 45.6 mN / m, viscosity at 25 ° C Was 3.7 mPa · s. This ink has the property that the color material component tends to remain relatively on the surface of the recording medium.

Black ink B
The following components were mixed and stirred for 3 hours, followed by filtration through a 2 μm membrane filter to obtain black ink B.
-25 parts of the above dispersion-15 parts of ethylene glycol monobutyl ether-5 parts of glycerin-0.5 part of diethylene glycol monobutyl ether-1 part of acetylene glycol ethylene oxide adduct (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.)
-Ion exchange water remainder The surface tension of this ink was 30.4 mN / m, and the viscosity at 25 ° C was 3.3 mPa · s. This ink has a property that the color material component is relatively easy to penetrate into the recording medium.

Black ink C
80 parts potassium hydroxide solution (neutralization rate 110%, resin solid content 60 parts) of styrene / acrylic acid / ethyl acrylate copolymer (acid value 200, weight average molecular weight 30000), 7 parts ethylene glycol, this solution After adding 8 parts of carbon black (MA-7; manufactured by Mitsubishi Chemical), the mixture was dispersed using a sand mill to prepare an aqueous dispersion (solid content of about 11%).

Next, the following components were mixed, stirred for 3 hours, and then filtered through a 3 μm membrane filter to obtain black ink C.
-50 parts of the above dispersion-15 parts of diethylene glycol-7 parts of glycerin-0.3 parts of acetylene glycol ethylene oxide adduct (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.)
-Ion exchange water remainder The surface tension of this ink was 42.1 mN / m, and the viscosity of 25 degreeC was 4.6 mPa * s. This ink has an intermediate property between the black ink A and the black ink B.

  Next, acidic dyes, basic dyes, direct dyes, organic pigments, and inorganic pigments described in the color index can be used for the color ink used in the present invention. As the pigment, a surface-modified self-dispersed pigment, an aqueous pigment dispersed by a polymer dispersion, or the like can be used.

  The following various color inks were prepared for use in the examples.

The components below yellow ink were mixed and stirred for 3 hours, and then filtered through a 2 μm membrane filter to obtain yellow ink.
・ C. I. ACID YELLOW 23 3 parts ・ Diethylene glycol 8 parts ・ Glycerin 10 parts ・ Acetylene glycol ethylene oxide adduct 0.1 part (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.)
・ Ion exchange water balance

80 magenta ink styrene / acrylic acid / ethyl acrylate copolymer (glass transition temperature 58 ° C., acid value 180, weight average molecular weight 8000) sodium hydroxide solution (neutralization rate 130%, resin solid content 2.5 parts) To a solution containing 5 parts of diethylene glycol. I. After adding 15 parts of Pigment Red122, dispersion was performed with a sand mill for 8 hours to obtain an aqueous dispersion. This dispersion was centrifuged (15000 rpm, 0.5 hour) to remove coarse particles, and an aqueous dispersion (solid content of about 13%) was prepared.

The following components were mixed, stirred for 3 hours, filtered through a 1 μm membrane filter, and further, inorganic impurities were removed through an ion exchange resin layer to obtain a magenta ink.
-40 parts of the above dispersion-10 parts of ethylene glycol-8 parts of glycerin-10 parts of diethylene glycol-0.5 part of acetylene glycol ethylene oxide adduct (trade name: acetylenol EH; manufactured by Kawaken Fine Chemical Co., Ltd.)
・ Ion exchange water balance

80 parts of a potassium hydroxide solution (neutralization rate 125%, resin solid content 5 parts) of cyan ink styrene / acrylic acid / ethyl acrylate copolymer (glass transition temperature 77 ° C., acid value 140, weight average molecular weight 6000), C. Washed with pure water in a solution containing 5 parts of ethylene glycol. I. Pigment Blue 15: 3 15 parts were premixed and then dispersed in a sand mill for 3 hours to prepare an aqueous dispersion (solid content of about 14%).

The following components were mixed and stirred for 3 hours, and then filtered through a 2 μm membrane filter to obtain a cyan ink.
・ Dispersion 40 parts ・ Diethylene glycol 8 parts ・ Glycerin 8 parts ・ Triethylene glycol 8 parts ・ Diethylene glycol monobutyl ether 0.5 part ・ Surfinol 465 (Nissin Chemical Industry Co., Ltd.) 0.5 part ・ Ion-exchanged water balance

1.3.2 Example
Example 1
The black ink A, the black ink B, and three kinds of color inks are filled in the ink cassette of the ink jet recording apparatus shown in FIG. 1, and the black recording head 2, the black recording head 1, and the color recording heads 3 to 5, respectively. To supply. As the black recording heads 1 and ² , those having an ejection opening area of 380 μm ² were used.

Then, on the white PC 180 g / m ² (corrugated cardboard liner, manufactured by Oji Paper Co., Ltd.), the black ink A recording head 2 is used to print the barcode and 8-point characters, the black ink B recording head 1 and the color recording head. Illustrations and logos were formed using 3-5. The blot rate of the dots printed by the recording head 2 was 2.0, and the blur rate of the dots printed by the recording head 1 was 2.8.

Example 2
The black ink A was supplied to the recording heads 1 and 2, and the various color inks were supplied to the color recording heads 3 to 5. Here, a black recording head 1 having a discharge port area of 400 μm ² and a black recording head 2 having a discharge port area of 330 μm ² were used.

Then, on the brown liner OFC 210 g / m ² (corrugated cardboard liner, manufactured by Oji Paper Co., Ltd.), the recording head 2 is used to display the barcode and 6-point characters, the recording head 1 and the color recording heads 3 to 5 are A logo was formed. The ink discharge amount of the recording head 1 was 27 ng, and the ink discharge amount of the recording head 2 was 23 ng.

Example 3
The black ink B, the black ink C, and three kinds of color inks are filled in the ink cassette of the ink jet recording apparatus shown in FIG. 1, and the black recording head 1, the black recording head 2, and the color recording heads 3 to 5, respectively. To supply. As the black recording heads 1 and ² , those having an ejection opening area of 410 μm ² were used.

Then, on the brown liner OFK 210 g / m ² (corrugated cardboard liner, manufactured by Oji Paper Co., Ltd.), the bar code and 6-point characters are displayed using the recording head 2, and the illustration and A logo was formed.

Example 4

The black ink A was supplied to the recording heads 1 and 2, and the various color inks were supplied to the color recording heads 3 to 5. Here, a black recording head 1 having a discharge port area of 400 μm ² and a black recording head 2 having a discharge port area of 380 μm ² were used.

Then, on the brown K liner 210 g / m ² (corrugated cardboard liner, manufactured by Oji Paper Co., Ltd.), the recording head 2 is used to print a barcode and 6-point characters under the following driving condition 2 and the recording head 1 and the color recording head 3. Illustrations and logos were formed under the following driving condition 1 using -5. The ink discharge amount of the recording head 1 was 26.5 ng, and the ink discharge amount of the recording head 2 was 23.2 ng.

(Drive condition 1) Double pulse drive: applied voltage 26 V, pre-pulse width 0.5 μs, pause time 2.5 μs, main pulse width 2.5 μs
(Drive condition 2) Single pulse drive: applied voltage 26 V, pulse width 2.8 μs.

Comparative Example 1
Recording was performed under the same conditions as in Example 1 except that the black ink A was supplied to both of the recording heads 1 and 2 in Example 1 (both had a discharge port area of 380 μm ² ).

Comparative Example 2
Black ink B was supplied to the recording heads 1 and 2 (both of which had an ejection port area of 430 μm ² ), and color ink was supplied to the recording heads 3 to 5 to perform recording under the same conditions as in Example 2.

1.4 Evaluation The printing results of Examples 1 to 4 and Comparative Examples 1 and 2 were evaluated as follows.

(Image quality evaluation)
The image density of the black solid recording portion was measured using a reflective photometer RD-918 (trade name) manufactured by Macbeth.

(Barcode characteristics)
The barcode recording part was verified 10 times by a verification machine (LASERCHEKII, manufactured by Fuji Electric Chiller).

  The evaluation results are shown in Table 1.

  In the above table, “◯” of the bar code suitability indicates that the bar code can be read all 10 times, and “x” indicates that the bar code cannot be read out of 10 times. Further, “◯” in the solid partial uniformity indicates that no white stripe is generated, and “×” indicates that a white stripe is generated.

2. Second Embodiment In the above embodiment, a case has been described in which the present invention is applied to a line printer type recording apparatus using a recording head in the form of a full line head in which ejection openings are arranged over the entire width of the recording medium. . However, the present invention can be applied to other types of recording apparatuses.

  FIG. 5 shows another embodiment of the ink jet recording apparatus to which the present invention can be applied, and the same reference numerals are given to the corresponding parts in the same manner as described above.

  The recording apparatus according to this example performs recording while repeatedly scanning the recording head in a direction perpendicular to the conveyance direction F of the cardboard box 11 as a recording medium and moving the recording head in a direction parallel to the conveyance direction F. It is the form to do.

  FIG. 6 is a front view of a recording head unit applied to such a recording apparatus. This recording head unit includes recording heads 31-1 and 31-2 for black ink, cyan (C), magenta (M), and yellow (Y) color inks in a scanning direction x orthogonal to the medium conveyance direction F. Recording heads 31-3 to 31-5 are juxtaposed. Each recording head has a plurality of ejection openings arranged in a direction different from the scanning direction x, for example, in a direction y parallel to the medium conveyance direction F perpendicular thereto. Here, as in the above embodiment, the recording head 31-1 is suitable for recording a so-called solid portion by forming a large area dot on the recording surface of the cardboard box 11, while the recording head 31-2. Is suitable for recording a dense portion by forming dots with a small area.

  In FIG. 5, reference numeral 35 denotes a carriage, which holds recording heads having the recording heads 31-1 to 31-5, and includes ink tanks 32-1 to 32-5 storing ink to be supplied to the recording heads. Hold. Further, the non-contact communication unit 15 is held on the carriage 35. The carriage 35 is supported and guided by a guide shaft 26x extending in the scanning direction x and can move in the same direction. Further, the carriage 35 is supported and guided by the guide shaft 26y extending in the y direction parallel to the conveyance direction F together with the guide shaft 26x, and can move in the same direction. Further, the carriage 35 is supported and guided by a guide shaft 26z extending in the vertical direction and can move in the same direction, thereby being able to cope with various heights and thicknesses of the recording medium.

  The cardboard box 11 serving as a recording medium is stopped at a position facing the movable range of the carriage 35 in the x and y directions, and is held by the non-contact integrated circuit board 17 by the non-contact communication unit 15 as the carriage 35 moves. After the information to be read is read and recording is performed by the recording heads or recording heads 31-1 to 31-5, the information is conveyed again and discharged out of the recording apparatus. Processing related to reading information is the same as in the first embodiment.

  In FIG. 1, reference numeral 21 denotes a controller interposed between the host device 109 and the non-driving element of the recording apparatus shown in the figure, and the cable 23 connected to the host device 109 and the x, y, and z directions. And a cable 24 for transmitting a signal for realizing the movement.

3. Others The present invention uses a first recording head for forming a recording dot with a relatively large area and a second recording head for forming a recording dot with a relatively small area, and the contents of an image to be recorded Accordingly, the portions to be recorded by both recording heads are divided so that optimum recording is performed respectively.

  In order to obtain different recording dot areas in this way, as described above, the first recording head (recording head 1 or recording head 31-1) and the second recording head (recording head 2 or recording head 31-2). ) Various modes such as varying the size of the two ejection openings, using inks with different bleeding rates on the recording medium, and varying the ink ejection amount by varying the driving conditions. I can give you. These embodiments may be used alone, or two or more of them can be appropriately combined.

  Further, in each of the above-described embodiments, different recording dot areas are realized for the black ink, but this may be realized for other inks as necessary. Furthermore, it goes without saying that the color tone (including color and density) or the number of inks used in the ink jet recording apparatus can be determined as appropriate.

  In addition, in the above example, it is assumed that recording is performed on a corrugated cardboard box which is a boxed and assembled form, but this may be in a folded state or in a deployed state before boxing, Alternatively, printing may be performed on a sheet-like cardboard material. Further, the present invention is suitable for application when printing an image in which the medium size and the area of the image forming area are large and the solid recording portion and the dense recording portion are mixed, and the recording medium Of course, it is not limited to the above example.

  In addition, in the above example, a non-contact type is used as a means for sending and receiving printing data and the like. However, for example, the combination of a barcode and a barcode reader can be appropriately determined. . The non-contact type is preferable in order not to interfere with the conveyance state of a recording medium such as a cardboard box and to shift the position. However, without such a concern, the use of a contact type is not excluded.

1 is a schematic side view of an ink jet recording apparatus according to a first embodiment of the present invention. 1 is a schematic perspective view of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration example of a control system of the ink jet recording apparatus according to the first embodiment of the present invention. 3 is a flowchart showing a recording processing procedure by the ink jet recording apparatus according to the first embodiment of the present invention. It is a typical perspective view of the inkjet recording device which concerns on the 2nd Embodiment of this invention. FIG. 6 is a schematic front view of a recording head applied to an ink jet recording apparatus according to a second embodiment of the present invention.

Explanation of symbols

1000 Host device (computer)
1 to 5 recording head 3 drum 11 cardboard box 14 transport belt 15 non-contact communication unit 17 RF-ID tag 31-1 to 31-5 recording head 32-1 to 32-5 ink tank 35 carriage 101 recording device 109 host device 600 MPU
603 VRAM

Claims (13)

An inkjet recording apparatus that performs printing on a recording medium using a first recording head for recording a relatively large area of recording dots and a second recording head for recording a relatively small area of recording dots. There,
Reading means for reading information for printing from the recording medium;
Identification means for identifying, based on the read information, a portion to be recorded by the first recording head and a portion to be recorded by the second recording head;
Means for driving the first and second recording heads to perform a recording operation based on the identification;
An ink jet recording apparatus comprising:   The inkjet recording apparatus according to claim 1, wherein the recording medium includes information holding means that can be read by the reading means.   3. The ink jet according to claim 1, wherein a portion to be recorded by the first recording head is a solid recording portion, and a portion to be recorded by the second recording head is a dense recording portion. Recording device.   The first and second recording heads differ in at least one of the size of the ejection port for ejecting ink, the surface tension of the ejected ink, the viscosity of the ejected ink, and the driving condition for ejecting ink. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is provided.   5. The ink jet recording apparatus according to claim 1, wherein the first and second recording heads are for ejecting black ink.   6. The ink jet recording apparatus according to claim 5, further comprising a recording head for discharging color ink.   7. The ink jet recording apparatus according to claim 1, wherein the recording medium is a cardboard liner paper.   2. The non-contact communication circuit for performing non-contact reading of the information from the information holding unit in the form of non-contact integrated circuit carried on the recording medium. The ink jet recording apparatus according to claim 7.   A recording medium capable of being printed by the ink jet recording apparatus according to claim 1, comprising an information holding unit readable by the reading unit.   The recording medium according to claim 9, wherein the information includes print data.   The recording medium according to claim 9, wherein the information includes control information for performing the identification.   12. The recording medium according to claim 9, wherein the information includes information indicating a recording medium type. An inkjet recording method for printing on a recording medium using a first recording head for recording a relatively large area of recording dots and a second recording head for recording a relatively small area of recording dots. There,
Reading information for printing from the information holding means carried on the recording medium;
Identifying a portion to be recorded by the first recording head and a portion to be recorded by the second recording head based on the read information;
Driving the first and second recording heads based on the identification to perform a recording operation;
An ink jet recording method comprising:

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