JPH0752375A - Printing method - Google Patents

Abstract

PURPOSE:To improve the productivity, enlarge the degree of designing freedom of printing contents and save printing costs by making it easy to handle an unnecessary ink even after printing of a wider area than a prescribed area in full-color printing according to an inkjet system using a water-soluble painting ink. CONSTITUTION:After a high-density layer is formed at a predetermined printing area of a work by a printing part 2, a receiving layer for color printing which contains a filler is formed on the high-density layer by a printing part 4. Then, an image data read by an original plate reading part 7 is supplied to a printing head of an inkjet multicolor printing part 6, whereby a pattern or the like corresponding to the image data is printed in colors on a printing surface of the work. At this time, the printing is done at a wider area than the predetermined printing area of the work. Thereafter, an unnecessary ink sticking out the printing area is sucked and removed by a suction nozzle or, dried and evaporated at a next processing part 8 for handling of an unnecessary ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing method in which image information is supplied to an ink jet type print head to perform full-color printing on an object to be printed such as paper, a plastic plate or a cassette.

[0002]

2. Description of the Related Art For example, disc cartridges containing optical disks, magneto-optical disks, etc., tape cassettes containing magnetic tapes (hereinafter collectively referred to as recording medium storage cases), are manufactured by our company. It is printed with a logo mark for asserting that it is and various designs added to enhance the commercial value.
Printing on the recording medium storage case is generally performed according to the following procedure.

First, an original having a design to be printed on a recording medium storage case is color-separated by a color CCD scanner. Then, after producing a color positive film according to the color separation, a plate for each color is produced. next,
After calibrating this, test printing on a cassette to adjust the ink viscosity. Finally, the color plates are registered and printed on the recording medium storage case.

Specifically, first, a white ink receiving layer containing a filler is formed on the surface of a recording medium housing case, and then full color printing is performed on the white ink receiving layer by ink jet to form a colored layer. Form. After that, a permeating aqueous protective liquid (varnish or top coat agent) is applied onto this colored layer to form a top coat layer.

[0005]

By the way, in the printing method by the ink jet method, it is general to use a water-soluble paint ink. Since this water-soluble paint ink does not have immediate dryness and its wettability with respect to the surface of the synthetic resin is not good, a phenomenon occurs in which the ink slightly scatters around the print area when the ink is sprayed on the specified print area.

In the conventional ink jet printing method, there is no established method for removing unnecessary ink that has overflowed from the specified print area defined on the recording medium storage case, so printing is performed on the outer periphery of the specified print area. Printing a little smaller (coloring) by leaving the unprinted part that is not applied
I am trying to apply. For this reason, there is a problem that printing cannot be effectively performed on the printing area.

When multicolor printing is performed in the printing area on the recording medium storage case by the multicolor printing method applying the ink jet, the ink is jetted so as not to shift the colored ink with respect to the formation area of the receiving layer. Therefore, it was impossible to spray the ink with the ink, and in order to perform printing so that the ink did not overflow from the forming area of the receiving layer, the printing had to be performed in a range narrower than the forming area of the receiving layer.

As described above, in the conventional printing method,
Since the printable area must be set small,
Due to design restrictions, the advantages of multicolor printing on the plastic surface by inkjet were not available, and there was an edge in the colored range, and it was not possible to express fine characters without edging. In this case, when the white-based receiving layer is used, it looks as if it was printed on the paper-based material attached to the recording medium storage case, and it appears directly on the plastic surface of the recording medium storage case. There is a problem that it is not possible to obtain an impression as if printed, and it is impossible to give an impression (impact) of appearance.

Further, the human eye has a high resolution, and is therefore sensitive to the difference in the width of the edging portion, and the narrower the edging, the more noticeable the deviation of the printed portion from the left, right, up and down. . There is a problem in that very high accuracy is required for the alignment of the printing portion with respect to the receiving layer, a highly sensitive sensor and a highly accurate alignment mechanism must be installed, and the printing cost becomes high.

Therefore, in the past, as a method of printing with a low level of alignment accuracy, that is, rough alignment, printing is performed slightly larger than the range of formation of the receiving layer.
A method has been considered in which unnecessary ink protruding from a prescribed printing area (reception layer forming area) is wiped off with a water-absorbent paper or cloth.

However, this method has a problem in yield since the workability is poor, and the printed surface may become dirty due to re-adhesion of unnecessary ink during wiping, resulting in a defective product. Thus, in the conventional method, since the decoction Ne can be improved in productivity, at present, is not set prospect of print method of performing a wider print than the formation range of the receiving layer.

Further, if an organic solvent-based paint ink is used as the ink, it can be realized by a much simpler printing system. However, considering the recent environmental problems, it is still a water-soluble paint ink. It will be necessary to realize full-color printing.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a full-color multicolor printing by an ink jet method using a water-soluble paint ink rather than a prescribed printing area. Even if printing is performed in a wide range, it is possible to easily process the unnecessary ink thereafter, and it is possible to effectively improve productivity, expand design flexibility of print contents, and reduce printing cost. To provide a printing method.

[0014]

SUMMARY OF THE INVENTION The present invention is a printing method for supplying color information to an object to be printed W by supplying image information to a print head of an ink jet system, wherein a high density layer is formed in a predetermined printing area of the object to be printed W. 21. After forming a base layer 22 for color printing containing 21 and a filler, color printing is performed in an area wider than the printing area, and a printing layer of a portion of the color printed portion that protrudes from the printing area. 23
a is removed.

Specifically, the portion of the print layer 23a that extends beyond the print area is removed by suction with a suction nozzle or by dry evaporation treatment.

[0016]

In the printing method according to the present invention, first, the base layer 22 for color printing containing the high-density layer 21 and the filler is formed in a predetermined printing area of the material W to be printed. afterwards,
The image information is supplied to an ink jet type print head, and color printing of a pattern or the like according to the image information is performed on the printing object W. At this time, color printing is performed in a larger area than the predetermined printing area of the printing material W.

After that, the print layer 23a of the portion protruding from the print region is removed by suction with a suction nozzle or dry evaporation treatment, for example.

As described above, according to the printing method of the present invention, since the color printing can be performed in a larger area than the predetermined printing area, the positioning accuracy of the color printing with respect to the base layer 22 can be made rough. Therefore, it is not necessary to install a highly sensitive sensor or a highly accurate alignment mechanism, and it is possible to effectively reduce the printing cost.

Further, since the color printing can be performed in an area larger than the predetermined printing area, there is no restriction in design, and the object to be printed W by ink jet is printed.
The advantage of multicolor printing on the printing surface (for example, plastic surface) can be fully exerted, and the impression (impact) that printing is directly applied on the plastic surface can be given.

In particular, since the unnecessary printing layer 23a protruding from the predetermined printing area is removed by suction with a suction nozzle or dry evaporation processing, the removal processing of the unnecessary printing layer 23a can be mechanized, and the color printing process can be fully automated. Can be promoted. Moreover, since the unnecessary printing layer 23a can be reliably removed, the productivity of the printed material (product) on which printing is performed is improved in combination with the mechanization.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A printing method according to the present invention will now be described with reference to a tape cassette containing a video tape or an audio tape.
An embodiment (hereinafter, simply referred to as a printing method according to the embodiment) applied to full-color printing on a recording medium housing case such as a disk cartridge in which a magnetic disk, an optical disk, or a magneto-optical disk is rotatably housed is shown in FIGS. This will be described with reference to FIG.

The printing method according to this embodiment is shown in FIG.
It is realized by an inkjet type printing system as shown in FIG.

As shown in the drawing, this printing system includes a work supply unit 1, a lower layer printing unit 2, a first drying unit 3, and a receiving layer in order from the stage where a work (in this case, a recording medium storage case) W is loaded. It is composed of a (middle layer) printing unit 4, a second drying unit 5, an inkjet multicolor printing unit 6, an unnecessary ink processing unit 8, an upper layer printing unit 9, a third drying unit 10, and a work discharge unit 11. The work W is sequentially carried to the above-mentioned respective parts by a carrying operation by the work carrying section 12.

Each section will be described below. First, the work supply unit 1 sequentially supplies one work from a large number of loaded works W to the work transfer unit 12, or stacks a large number of magazines in which a large number of works W are arranged in a plane. This is a part where one magazine is sequentially supplied to the work transfer section 12 from the outside. In the following description, for simplification of description, a case where full-color printing is performed on one work W will be mainly described.

Next, the lower layer printing section 2 is a section for forming the first high adhesion layer 21 on the surface of the work W, as shown in FIG. Here, the high adhesion layer 21 serves as an anchor layer and an adhesion layer, and adheres the second and subsequent layers to the synthetic resin which is a constituent material of the work (recording medium storage case) W. It is a layer for improving the property.

The material used for the high adhesion layer 21 is appropriately selected in consideration of the adhesiveness with the synthetic resin which is the constituent material of the work W, and the following materials can be mentioned.

1. Solvent-based adhesive (dissolves and adheres the surface of the work W) 1. Solvent-based silk screen ink 3. Alumina + water-soluble resin + water 4. A double-sided tape having an upper surface coated with water-based glue and a lower surface coated with an adhesive that adheres to the surface of the tape cassette can be used instead.

In this example, a layer having the components shown below was formed.

Polyester resin solution 45.0% by weight Titanium oxide 45.0% by weight Defoamer 2.0% by weight Solvent 5.0% by weight Other additives 3.0% by weight

Then, in the lower layer printing section 2, the above materials are formed on the surface of the work W so as to have a thickness of 50 to 500 μm. It is preferably applied so as to have a thickness of about 200 μm.

Next, as shown in FIG. 2, the receiving layer printing section 4 receives the receiving layer 2 containing the filler and the binder as the second layer.
It is a part forming 2. The receiving layer 22 also contains, for example, a white pigment that aids in the color development of the water-soluble coating ink that will be formed later, and functions as a base layer for the subsequent full-color printing. The acceptance layer 22 is 3 to 10
It is formed to have a thickness of 0 μm.

The following are examples of the components of the coating material applied to form the receiving layer 22.

Polyvinyl alcohol resin 8.5% by weight Synthetic silica powder 15.0% by weight Distilled water 60.0% by weight Hydrophilic solvent 15.0% by weight Other additives 1.5% by weight

In addition to the above examples, as the filler, a material having a large water absorption amount such as alumina, calcium carbonate, talc, diatomaceous earth, or zeolite is preferable in place of silica, and the ink absorption amount of this layer 101 is 10 ml / cm. ^It is preferable to form it so as to be ² or more. Also, as a binder,
Instead of gelatin or polyamide alkoxide, a water-soluble polymer such as polyacrylamide, starch, gum arabic or the like can be used. Furthermore, examples of the synthetic resin include polyamide resin and alkyd resin.

When the ink composition is formed by ink jet printing, the above component ratio is appropriately changed depending on the diameter of the nozzle of the print head, the background color of the work W, the hiding ratio, and the like.

Next, the ink jet multi-color printing unit 6 sprays the water-soluble paint ink from a plurality of print heads prepared for each color to perform full-color printing, and as shown in FIG. This is a portion where the colored layer 23 is formed. In this embodiment, as the water-soluble paint ink, a cyan paint ink Cy, a magenta paint ink Mz, a yellow paint ink Ye, and a black paint ink Bk are used. Of course, a specific colored ink other than the primary colors may be used.

The pattern formed by this full-color printing is, for example, a logo mark for asserting that it is a product of the company, various designs added to enhance the commercial value, and this work W is, for example, a video. In the case of a tape cassette, a design that characterizes the recorded contents recorded on the video tape (for example, one scene of an athletic meet or one scene of a recorded movie) is a design represented by two or more colors. When W is, for example, a disc cartridge in which a magneto-optical disc is rotatably accommodated, a design (for example, a photograph of the face of the performer of the recorded song) that characterizes the recorded content recorded on the magneto-optical disc is 2 It is a picture that is expressed in more than color.

The plurality of print heads are provided in the original reading section 7
It is controlled based on the image information from, and is configured to perform multicolor printing on the work W. The original reading unit 7 is provided with an image reading means (not shown) such as an image reader or a copying machine for electrically reading the print contents (pictures, etc.) from the original printed on a photograph or paper. Head control means (not shown) for controlling the ink ejection amount of each print head of the multicolor printing section is incorporated based on the image information from the image reading means.

The head control means, in addition to the image information from the image reading means such as an image reader or a copying machine, the ink ejection amount of each print head based on a printing image created by direct image processing by a computer. Can also be configured to control.

The component ratios in the case of the above water-soluble paint ink are shown below. The water-soluble paint ink used in this example was one that did not have immediate dryness and generally had poor wettability on the synthetic resin surface.

Dye 1% by weight Diethylene glycol 29% by weight Water 70% by weight

In this full-color printing, by preparing a receiving layer 22 having different properties, for example, one having a receptive capacity for water-soluble ink and one having a receptive capacity for oil-based ink, a desired standard can be obtained.
A suitable type of ink can be selected and printed according to the designated design. The full-color printing may be performed by silk screen printing, PAD printing, or offset printing in addition to the inkjet printing according to this embodiment. However, as in this embodiment, the inkjet printing system is used. By doing so, it is possible to print according to a large number of small quantities even after assembly.

As shown in FIG. 4, the multicolor printing unit 6 sprays the water-soluble coating ink in a range e wider than the forming range c of the receiving layer 22 formed in the lower layer to perform full color printing. That is, when the horizontal and vertical dimensions of the forming range c of the receiving layer 22 are Xc and Yc, and the horizontal and vertical dimensions of the spraying range of the water-soluble coating ink are Xe and Ye, respectively, the dimensional relationship is Xc <Xe, Full-color printing is performed by spraying a water-soluble paint ink so that Yc <Ye. Here, a portion that is projected from the receiving layer 22 and the ink is sprayed is referred to as an over area printing portion in the following description.

In this case, since the water-soluble paint ink having a poor wettability on the synthetic resin surface is used, the ink is directly sprayed on the synthetic resin surface of the work W like the over-area printing portion. Then, as shown in FIG. 3, the ink 23a is in the state of particles, that is, in the state of polka dots, on the sprayed surface. The size of each particle of the ink 23a is about several tens of μm, but the particles of the ink 23a that are close to each other attract each other due to the amount of the ink or the overlapping condition of the inks of the respective colors to form a larger particle. In some cases.

Next, the unnecessary ink processing section 8 forms a polka dot-shaped unnecessary ink 23 formed in the above-mentioned over area printing portion.
This is a part for removing a, and two facilities are selectively installed.

First, one piece of equipment is, as shown in FIG.
The unnecessary ink removing means 31 uses a vacuum source.
The unnecessary ink removing means 31 is provided with a vacuum pump 32 as a vacuum source and a plurality of suction nozzles at least at a position corresponding to the over area printing portion, and the operation of the vacuum pump 32 eliminates the need for the over area printing portion. A suction head 33 that sucks and removes the ink 23a, and the suction head 33 that moves the work 23
It is composed of a vertical movement mechanism 34 for moving the work W on the upper side 2 in the contact and separation direction, and a tank 35 for storing the unnecessary ink 23a sucked by the suction head 33.

As shown in FIG. 7, the tank 35 has the first tube 3 led out from the suction head 33 at the upper part thereof.
6 and the second tube 37 led out from the vacuum pump 32 are attached, and the openings of the tubes 36 and 37 are fixed so as to face the inside of the tank 35, respectively. Further, a valve 38 is attached to the second tube 37 in the middle of its piping path.

The operation of the unnecessary ink removing means 31 will be described. First, the work W conveyed to the unnecessary ink processing portion 8 by the work conveying portion 12 is supported at an appropriate position, for example, by the vertical movement mechanism 34. It stops at a position just below the suction head 33 that is present. After that, suction head 3
Work W 3 is located right below by the vertical movement mechanism 34
Descend to a position close to. The valve 38 opens at the timing of the lowering of the suction head 33, and the vacuum pump 32 becomes ready for suction.

When the suction head 33 reaches the bottom dead center, the suction operation by the vacuum pump 32 causes the unnecessary ink 23a in the over-area printing portion to be sucked and removed through the suction head 33.

The sucked unnecessary ink 23a is sent into the tank 35 through the first tube 36. That is, as shown in FIG. 7, the unnecessary ink 23a sucked and guided in the first tube 36 is released at the opening of the first tube 36 facing the inside of the tank 35, and is discharged to the bottom of the tank 35 by its own weight. Will accumulate. At this time, the unnecessary ink 23
The air sucked together with a is discharged to the vacuum pump 32 side through the second tube 37.

After a lapse of a fixed time, the valve 38 is closed and the process of removing the unnecessary ink 23a by the suction head 33 is completed. At the same time, the vertical movement mechanism 34 is used to move the suction head 3
3 moves upward and returns to the initial position. Unnecessary ink 2
The work W from which 3a has been suctioned and removed is transported to the next step by the work transporting unit 12 at the same time when the suction head 33 moves up.

The unnecessary ink removing means 31 using the vacuum source temporarily stops the work W and then removes the unnecessary ink 23a.
However, the suction head 33 is synchronized with the feeding of the work W without stopping the work W.
The unnecessary ink 23a may be removed by suction.

Further, the vertical moving mechanism 34 for moving the suction head 33 up and down is, for example, a scalar type robot, and as described above, a large number of suction nozzles provided on the suction head 33 are used for over-area printing. As shown in FIG. 8, the suction head 33 is configured as a suction head (for example, synthetic resin) 33a having a nozzle shape and size capable of sucking only a certain area as shown in FIG. May be. In this case, when the suction head 33a is moved by the robot to move the suction head 33a closer to the over-area printing portion and further move along the over-area printing portion, the unnecessary ink 2 in the over-area printing portion is removed.
It becomes possible to remove 3a by suction.

Next, other equipment selectively installed in the unnecessary ink processing unit 8 is, as shown in FIG. 9, an unnecessary ink removing means 4 by a dry evaporation process using a heat source (heater).
It is 1. The unnecessary ink removing means 41 has a structure similar to that of a so-called electric furnace, and has a heater 43 selectively heated by a heater driving part 42 and a fan driving part 44 in the furnace in which the work transfer part 12 is arranged. And a fan 45 that circulates the heat generated from the heater 43. The inside of the furnace is kept at a uniform drying temperature, for example, about 50 to 60 ° C., by the heat generated by the heater 43 and the air circulating action by the fan 45.

The operation of the unnecessary ink removing means 41 will be described. First, the work W carried into the furnace by the work carrying section 12 is stopped at an appropriate position, for example, a position directly below the heater 43, and the work W is made uniform. Let stand for about 15 minutes in an oven maintained at the drying temperature. At this time, the unnecessary ink 23
The water contained in a is evaporated, and as a result, the unnecessary ink 23
a will dry and evaporate.

In this case, as shown in FIG. 10, the dried unnecessary ink 23a remains in dots (the size of each dot is several hundred μm or less), but the unnecessary ink 23a of several tens μm or less cannot be discriminated by the naked eye. It becomes small and disappears. Although it depends on the quality of the product as the work W, when the color of the synthetic resin surface of the work W is blackish, the dried unnecessary ink 23a becomes almost inconspicuous, and as described later, the top coat layer is formed on the upper layer. Therefore, even if the dry unnecessary ink 23a remains, it is not directly subjected to external friction during use, and the unnecessary ink 23a is peeled off to stain the surrounding printing surface 46. Does not occur. Further, since the unnecessary ink 23a is dried, there is no problem that the unnecessary ink 23a penetrates into the top coat layer formed on the upper layer.

In the furnace, the work W, which has been dried and vaporized for the unnecessary ink 23a in the over-area printing portion, is carried to the next step by the work carrying section 12.

In the above example, the work W is stopped in the furnace and left to stand for a predetermined time for dry evaporation processing. The unnecessary ink 23a in the over-area printed portion may be dried and evaporated by transporting for a predetermined time. It is needless to say that the atmospheric temperature in the furnace and the leaving time of the work W (time during which the work is transported in the furnace) are appropriately set depending on the material of the work W, the composition of the ink, and the amount.

In the above example, the temperature of the atmosphere in the furnace is raised by the heater 43 and the fan 45,
Although an example in which the dry evaporation process is performed is shown, the humidity in the furnace may be lowered or the atmospheric pressure may be decreased to perform the dry evaporation process.

As described above, the unnecessary ink removing section 8 comprises two means, that is, an unnecessary ink removing means 31 using a vacuum source and an unnecessary ink removing means 41 by a dry evaporation process using a heat source (heater). However, no matter which method is used, the ink will not be transferred to the hand after the treatment, and as a result, the product after printing will be easy to handle and the ink There is no problem such as stains on the printing surface 46 due to the reattachment of.

The above-mentioned over-area printing portion does not need to be excessively wide, and is as narrow as possible in order to reduce the amount of unnecessary ink as much as possible and to carry out dry evaporation processing or suction removal in a short time. It is preferable to set.

Next, as shown in FIG. 2, the upper layer printing section 9 improves the characteristics such as alcohol resistance and scratch resistance of the colored layer 23 and the sharpness of the pattern printed in full color on the colored layer 23. Is a portion where the transparent topcoat layer 24 having a relatively large film thickness is formed for the purpose of increasing the film thickness.

The material of the top coat layer 24 is
Water-soluble synthetic resin or water-based varnish, oil-based varnish (organic solvent-soluble resin + solvent), UV-based top coat, silk screen ink and the like can be used. As a commercially available product, an oily clear spray manufactured by Kansai Paint can be used.

Next, the first drying section 3, the second drying section 5 and the third drying section 10 are all constituted by a thermal drying oven in this embodiment, and each of the layers formed in the previous step is used. It is installed for the purpose of drying. That is, the first drying unit 3 dries the high adhesion layer 21 formed in the lower layer printing unit 2, the second drying unit 5 dries the receiving layer 22 formed in the receiving layer printing unit 4, and The drying unit 10 dries the top coat layer 24 formed in the upper layer printing unit 9.

The drying sections 3, 5 and 10 may be dried by heat or may be dried or cured by another method such as ultraviolet rays depending on the composition of the ink constituting the layers.

Next, a method of performing full-color printing on the work W by the above-mentioned inkjet type printing system will be described.

First, the work supply unit 1 to the work transfer unit 1
The work W input to the second work 2 is transferred to the next lower layer printing unit 2 by the transfer by the work transfer unit 12,
A high adhesion layer 21 is formed in a predetermined region on the upper surface of the. The work W on which the high adhesion layer 21 has been formed is again conveyed by the work conveying section 12 and put into the next first drying section 3.

In the first drying section 3, the high adhesion layer 21 formed on the upper surface of the work W is dried. When the drying process for the high adhesion layer 21 in the first drying unit 3 is completed, the work W is conveyed to the next receiving layer printing unit 4 by the work conveyance unit 12, and the high adhesion layer 21 is formed in the upper surface of the work W. The receiving layer 22 is formed on the formed portion. The work W on which the receiving layer 22 has been formed is again conveyed by the work conveying section 12 and put into the next second drying section 5.

In the second drying section 5, the receiving layer 22 formed on the upper surface of the work W is dried.
When the drying process for the receiving layer 22 in the second drying unit 5 is completed, the work W is transported to the next inkjet multicolor printing unit 6 by the work transport unit 12, and in the inkjet multicolor printing unit 6, the work W is processed. Full-color printing is performed over a wider area than the area where the receiving layer 22 is formed on the upper surface of the.

After that, the work W, which has been subjected to the full-color printing, is transferred to the next unnecessary ink processing unit 8 in the work transfer unit 12.
Be transported to. In the unnecessary ink processing unit 8, if the equipment constituting the processing unit 8 is, for example, the unnecessary ink removing means 31 using a vacuum source, the suction head 33 sucks and removes the unnecessary ink 23a in the over-area printing portion. Alternatively, if the equipment constituting the processing unit 8 is the unnecessary ink removing means 41 by the dry evaporation process using the heater 43, for example, the unnecessary ink 2 in the over area printing portion is set in the oven kept at the drying temperature.
3a is dried and evaporated.

The work W from which the unnecessary ink 23a in the over area printing portion is removed in the unnecessary ink processing section 8 is conveyed to the next upper layer printing section 9 by the work conveying section 12, and in this upper layer printing section 9, Top coat layer 24
Is formed. The work W on which the top coat layer 24 is formed is again conveyed by the work conveying section 12 and put into the next third drying section 10.

In the third drying section 10, the work W
A drying process is performed on the top coat layer 24 formed on the upper surface of the. The top coat layer 24 in the third drying section 10
After the drying process is completed, the work W is conveyed to the next work ejecting unit 11 and ejected by the work conveying unit 12.

As described above, in the printing method according to this embodiment, full-color printing can be performed in an area wider than the predetermined printing area, and therefore, the alignment accuracy with respect to the base layer of full-color printing, that is, the receiving layer 22 can be improved. Can be done roughly. Therefore, it is not necessary to install a highly sensitive sensor or a highly accurate alignment mechanism, and it is possible to effectively reduce the printing cost.

Further, since the color printing can be performed in an area wider than the predetermined printing area, there is no design restriction, and the printing surface (in this case, the plastic surface) of the work W by the ink jet method can be applied. The full-color printing advantages of can be fully exerted, and the impression (impact) of printing directly on the plastic surface can be given.

In particular, since the unnecessary ink 23a in the over-area printed portion which is out of the predetermined printing area is removed by suction and dry evaporation processing by the suction head 33 in the unnecessary ink processing section 8, the unnecessary ink 23a is removed. Mechanization can be achieved, and full automation of the full-color printing process can be promoted. Moreover, the unnecessary ink 23a is surely provided.
Since it is possible to remove the above, it is possible to improve the productivity of the printed work (product) W in combination with the above mechanization.

In the above example, the full-color printing for one work W has been mainly described, but in addition, for a plurality of works W stored in a magazine in which a large number of works W can be arranged and stored in a plane. It can also be applied when performing full-color printing at the same time.

The full-color printing in the ink jet multicolor printing section 6 is performed by the receiving layer 22 formed in the previous step.
Although the ink is sprayed in a range wider than the formation range c, the ink may be sprayed in a range e narrower than the formation range c of the receiving layer 22 as shown in FIG. In this case, it is possible to obtain the same border printing mode as in the related art.

[0078]

As described above, according to the printing method of the present invention, in the printing method of supplying the image information to the ink jet type print head to perform the color printing on the printing object, the predetermined printing of the printing object is performed. After forming an underlayer for color printing containing a high-density layer and a filler in the area, color printing was performed in an area wider than the above-mentioned printing area, and out of the above-mentioned printing area in this color-printed portion. Remove the printed layer on the part. Specifically, the print layer in the portion protruding from the print area is suctioned and removed by a suction nozzle,
Alternatively, since it is dried and evaporated to remove it, in the full-color multicolor printing by the inkjet method using a water-soluble paint ink, even if the printing is performed wider than the specified printing area, unnecessary ink The processing can be easily performed, and productivity can be improved, design flexibility of print contents can be expanded, and printing cost can be reduced effectively.

[Brief description of drawings]

FIG. 1 is a block diagram showing a printing method according to the present invention, in which a tape cassette in which a video tape or an audio tape is stored and a recording medium storage case such as a disk cartridge in which a magnetic disk, an optical disk or a magneto-optical disk is rotatably stored (workpiece) 2] is a configuration diagram schematically showing an inkjet type printing system for realizing the embodiment applied to full-color printing in FIG.

FIG. 2 is a cross-sectional view showing a laminated structure of layers formed on a print area of a work by a printing method according to an embodiment.

FIG. 3 is a cross-sectional view showing a coloring layer formed on a print area of a work by a printing method according to an embodiment and unnecessary ink in an over area print portion.

FIG. 4 is a perspective view showing a work that has been subjected to full-color printing (over-area printing) by spraying a water-soluble coating ink in a range wider than the forming range of a receiving layer formed in the lower layer.

FIG. 5 is a perspective view showing a work which has been subjected to full-color printing (rimming printing) by spraying a water-soluble coating ink in a range narrower than a forming range of a receiving layer formed in a lower layer.

FIG. 6 is a configuration diagram schematically showing an unnecessary ink removing unit using a vacuum source selectively installed in an unnecessary ink processing unit.

FIG. 7 is a configuration diagram schematically showing a tank installed in an unnecessary ink removing unit using a vacuum source.

FIG. 8 is a cross-sectional view showing another example of a suction head installed in an unnecessary ink removing unit using a vacuum source.

FIG. 9 is a configuration diagram schematically showing an unnecessary ink removing unit by a dry evaporation process using a heat source (heater) selectively installed in an unnecessary ink processing unit.

FIG. 10 is a front view showing the print surface of the work after the drying and evaporation process by the unnecessary ink removing means using the heat source (heater).

[Explanation of symbols]

W Work 1 Work supply unit 2 Lower layer printing unit 3 First drying unit 4 Receiving layer (middle layer) printing unit 5 Second drying unit 6 Inkjet multicolor printing unit 7 Original plate reading unit (image processing unit) 8 Unnecessary ink processing unit 9 Upper layer Printing part 10 Third printing part 11 Work discharge part 12 Work transfer part 21 High adhesion layer (lower layer) 22 Receiving layer (middle layer) 23 Coloring layer 23a Unnecessary ink 24 Top coat layer (upper layer) 31 Removal of unnecessary ink using vacuum source Means 32 Vacuum pump 33 Suction head 34 Vertical movement mechanism 35 Tanks 36 and 37 First and second tubes 38 Valve 41 Unnecessary ink removing means by dry evaporation treatment using a heat source (heater) 42 Heater drive unit 43 Heater 44 Fan Drive unit 45 fan

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Claims (3)

[Claims] 1. A printing method in which image information is supplied to an inkjet print head to perform color printing on a printing material, which comprises a high-density layer and a filler in a predetermined printing region of the printing material. After forming the underlayer of, the color printing is performed in an area wider than the printing area, and the printing layer of the portion that is out of the printing area is removed from the color printed portion. 2. The printing method according to claim 1, wherein a portion of the print layer that extends beyond the print area is removed by suction with a suction nozzle. 3. The printing method according to claim 1, wherein a portion of the printing layer that extends beyond the printing area is dried and evaporated to be removed.