JPS6259093A - Printing plate, printing method and plate-making device - Google Patents

Abstract

PURPOSE:To enable thick-film printing, by providing the recessed parts of a predetermined pattern on projected parts constituting a picture element part of a letterpress plate. CONSTITUTION:Projected parts constituting the picture element part are provided with recessed parts of the predetermined pattern. An ink shown by slashes is amply built up on a plate surface because the recessed parts function as ink reservoirs. When the plate surface is pressed against an object to be printed, the recessed parts function to prevent the ink from being pushed out to the outside of a picture element part. Accordingly, thick film printing with an extremely large ink thickness can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel printing plate, printing method, and plate making device that enable thick film printing in letterpress printing.

(Prior art and its problems) Printing with large ink thickness (generally referred to as thick film printing)
For example, in the manufacture of electronic components such as printer 1 to I2M boards and thick film ICs, thick film ink such as conductive paste or etching resist is printed on the substrate in a pattern.
In addition to being used in cases, it is also used as needed in the manufacture of industrial products other than electronic parts and in general printing applications. When performing such thick film printing, printing methods such as stencil (screen printing plate), intaglio (including clavier printing plate), and flat concave printing methods have conventionally been used depending on the purpose. However, due to the characteristics of this printing method, letterpress
When the printing plate is pressed against the printing material, the ink is pushed out and bulges around the image area (contour area), and as a result, the ink thickness decreases inside, making it impossible to form a uniform thick film. Conventionally, it has not been used in the field of thick film printing.

However, this letterpress printing method is the simplest plate method compared to other printing plate methods, and it is easy to apply ink to the plate surface and has high printing accuracy, and it also uses a relatively wide range of ink types. In addition to being able to choose freely, flat pressure 1 circular pressure 1
It can be used with any rotary printing method, offering a high degree of freedom. Furthermore, it is possible to manufacture multiple plates relatively easily and quickly from the original plate, and the plate has good durability (high printing durability), which works well with the ease of handling and high degree of freedom mentioned above. As a result, it has many advantages over other printing plate methods, including the ability to achieve high overall productivity. Therefore, if it becomes possible to perform thick film printing using a letterpress, not only will the uses of letterpress printing further expand, but it will also be possible to further improve productivity in the field of thick film printing.

(Object of the invention) This invention was made from the above-mentioned viewpoints,
The purpose is to provide a new printing plate, printing method, and plate making device that enable thick film printing in letterpress printing.

(Means for Achieving the Object) In order to achieve the above object, in the printing plate according to the present invention, recesses in a predetermined pattern are provided on the projections representing the image areas of the relief plate.

Furthermore, in order to achieve the above object, in the printing method according to the present invention, recesses having a predetermined pattern are provided on the projections representing the image areas of the relief plate, and printing is performed using the relief plate with the recesses. ing.

That is, in this invention, the amount of ink transferred to the plate surface by the function of the recessed portions is increased more than in the conventional letterpress plate, thereby making thick film printing possible.

(Example) FIG. 1 is an explanatory diagram showing an example of a printing plate used in the printing method according to the present invention in comparison with a conventional letterpress printing plate. In Figure 1, (a) is the original drawing, (b) is a conventional letterpress obtained based on the original drawing, (C) is a cross-sectional view taken along the line C-C in (b), and (d) is based on the original drawing. (e) shows a cross-sectional view taken along line ee in (d), respectively. In FIGS. 1(b) and 1(d), the shaded areas represent relief printing.

In the conventional letterpress printing method, as shown in (b) and (c), the drawing area corresponds to the original image and is 6 times smaller than the non-printing area.
It is formed as a convex flat ridge on the plate surface. On the other hand, in the plate according to the present invention, as shown in (d) and (e), concave portions having a predetermined pattern are formed in the convex portions representing the image areas. This predetermined pattern is shown in FIG.
Although a repeating single line pattern is used in the embodiments of ) and (e), other patterns such as a gravure mesh may be used, and either a repeating pattern or a non-repetitive pattern may be used. The depth of the concave portion is preferably smaller than the height of the convex portion, as shown in the cross-sectional view of FIG. 1(e).

In the embodiments shown in FIGS. 1(d) and 1(e), concave portions are not formed in the contours of the image areas, but convex portions are left as they are. This is because if a recess is formed in the contour and the contour of the image area is interrupted, the edges of the printed image may become jagged, so it is preferable to leave the contour as a convex portion.

In this case, it is also possible, for example, to leave only the contour portion as a convex portion and form concave portions in all other portions. However, when such a pattern of concave portions is formed, when the print area becomes large, a situation arises in which the ink buildup on the printing plate becomes concave in the center. Therefore, preferably, as shown in the embodiments of FIGS. 1(d) and 1(e), recesses are formed in some predetermined pattern, and a suitable earth embankment (i.e., a protrusion) is formed inside the contour. It is desirable to leave it there. In addition, if this original plate is prepared by photolithography, for example, this earthen wall may have the minimum necessary width to take side etching into account.

FIG. 2 is an explanatory diagram showing a state in which ink has been applied to a printing plate according to the present invention. As shown in the figure, ink indicated by diagonal lines is abundantly deposited on the printing plate because the recesses formed as described above act as ink reservoirs.

Furthermore, even when the printing plate is pressed against the printing material, the movement of the recesses prevents ink from being pushed out to the periphery of the image area. Therefore, compared to conventional letterpress printing, it is possible to perform thick film printing using a much thicker ink.

Next, a method for producing a plate for use in the printing method according to the present invention will be described. As mentioned above, as long as the relief plate has concave portions formed in a predetermined pattern on the convex portions representing the image areas, the plate can be made by any method such as mechanical, chemical, photochemical, electronic, etc. However, from a practical point of view, an example using a plate-making scanner and an example using an electronic engraving plate-making machine will be described below.

As is well known, a plate-making scanner is a device that photoelectrically scans an original image and sequentially scans and exposes a photosensitive film to produce an image negative film necessary for photolithography. In this embodiment, a circuit as shown in the block diagram of FIG. 3 is applied to such a plate-making scanner. For example, the fourth
If the original image shown in Figure (a) is sequentially scanned, Figure 4 (
An output image as shown in b) is obtained.

In FIG. 3, well-known sharp signals and unsharp signals, which are image signals obtained by photoelectrically scanning an original image, are input to binarization circuits 1 and 2, respectively. As shown in FIGS. 5(b) and 5(c), these sharp signals and unsharp signals have the characteristics shown in FIG. These signals can be easily created using optical or electronic circuit methods, such as those disclosed in Japanese Patent Application Laid-Open No. 59-141871.

The binarization circuits 1 and 2 discriminate the input sharp signal and unsharp signal using appropriate threshold values, respectively, and
The signals E and E shown in FIGS. 5(d) and 5(e) are output, respectively. At this time, the threshold values are appropriately selected in advance so that the signal width of the signal E corresponds equally to the width of the original image, and the signal width of the signal E is slightly narrower than the width of the original image. These signals, E, are input to the exclusive OR gate 3, and from the exclusive OR gate 3, as shown in FIG.
An edge signal G corresponding to the outline of the original image is output.

On the other hand, a pattern (single line screen) signal as shown in FIG. The single line screen) signal F is subjected to gate processing, and the recess pattern signal H as shown in FIG. 5(h) is derived from the output terminal of the AND gate 1-4. -1 is input to the OR gate 5, and an exposure image signal I as shown in FIG.

Using the exposure image signal I obtained in this way, the photosensitive film is sequentially exposed in synchronization with the scanning of the original image using a well-known plate-making scanner, and then a predetermined development process is performed, for example, as shown in FIG. For an original image as shown in (a), an image negative film as shown in FIG. 4(b) is obtained. After that, by using this image negative film as a printing master plate and making a letterpress plate using a normal photoengraving process, plates like those shown in Figures 1(d) and (e) can be produced. can. At this time, the depth of the concave portion can be changed appropriately by adjusting the exposure amount for printing within a range that does not cause lack of relief due to insufficient exposure.

Furthermore, in order to make the depth of the concave portion smaller than the height of the convex portion, a circuit as shown in the block diagram of FIG. 6, for example, may be applied to the plate-making scanner instead of the circuit of FIG. . In the circuit shown in FIG. 6, after adjusting the level of the concave pattern signal H shown in FIG. 5(h), the signal H shown in FIG.
), a signal 8J as shown in FIG. 5(j) is outputted to the output terminal of the subtracter 6 as an image signal for exposure. And this exposure image signal J
After creating a continuous-tone image negative film using the above method, the desired original plate can be obtained by performing a normal photoengraving process.

Next, an example using an electronic engraving and plate making machine will be described.

As is well known, an electronic engraving machine is a device that photoelectrically scans an original image and directly engraves a letterpress printing plate using the function of an electronic circuit. In this embodiment, a circuit as shown in the block diagram of FIG. 7 is applied to such an electronic engraving and plate making machine.

In the circuit shown in FIG. 7, a sawtooth signal K as shown in FIG. 5(k) is introduced into gate 7, and a signal ``in FIG. The above sawtooth signal K is gated and the fifth
A signal M shown in FIG. 7(m) is derived from the gate 7. Then, this signal M and the sharp signal shown in FIG. 5(b) are subjected to addition t1 processing by an adder 8 to obtain an engraving image signal @N as shown in FIG. 5(n). After that, as shown in FIG. 8(a), if the moving path (dotted line) of the engraving needle of the electronic engraving plate-making machine is set in the positional relationship as shown with respect to the plate material 9, It is possible to produce an original plate as shown in (b).

The depth of the recess adjusts the amplitude of the sawtooth signal above,
This allows for appropriate changes.

Although Figures 1 and 4 illustrate the pattern of a single line screen (straight line screen), a pattern similar to the mesh white line screen used in gravure printing can also be used.
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Note that the plate material used in this invention may be a metal plate or a resin plate. In addition, the process of producing an image negative film using the plate-making scanner described above is performed using the conventional photographic method (1-1).
Although it is possible to do this by using the in-line method, the netting method, etc., it is not practical because the process becomes extremely complicated, requires a large number of steps, and requires a high level of skill.

(Effects of the Invention) As explained above, according to the present invention, since printing is performed using a letterpress plate on which concave portions are formed in a predetermined pattern, thick film printing is possible in letterpress printing. It is possible to realize a new printing method.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a printing plate used in the printing method according to the present invention in comparison with a conventional letterpress; FIG. 2 is an explanatory diagram showing the case where the plate according to the invention is inked;
The figure is a block diagram showing one embodiment of the circuit applied to the plate-making apparatus according to the present invention, FIG. 4 is an explanatory diagram of input and output images according to the present invention, and FIG. 5 is a diagram showing waveforms of various parts of the circuit according to the present invention. , FIGS. 6 and 7 are block diagrams showing other embodiments of the circuit applied to the plate making apparatus according to the present invention, and FIG. 8 is an explanatory diagram when performing electronic engraving plate making according to the present invention.

Claims (11)

[Claims] (1) A printing plate characterized in that concave portions having a predetermined pattern are provided in the convex portions representing the image areas of the relief plate. (2) The printing plate according to claim 1, wherein the outline of the image area is left as a convex portion. (3) The printing plate according to claim 1, wherein the depth of the concave portion is smaller than the height of the convex portion. (4) A printing method characterized in that a concave portion having a predetermined pattern is provided in a convex portion representing an image area of a relief plate, and printing is performed using this relief plate. (5) The printing method according to claim 4, wherein the outline of the printed line portion is left as a convex portion. (6) The printing method according to claim 4, wherein the depth of the concave portion is smaller than the height of the convex portion. (7) A predetermined pattern signal is output in correspondence with the image line portion of the image signal obtained by photoelectrically scanning the original image, and based on this pattern signal, a recess formed in a predetermined pattern is formed on the relief plate representing the image portion of the relief plate. A plate-making device characterized in that it produces a plate on which is formed. (8) A plate-making apparatus according to claim 7, which produces a plate from a signal including an outline of an original image and a pattern inside the outline of the original image. (9) The plate-making apparatus according to claim 7, wherein the pattern signal is formed so that the depth of the concave portion is smaller than the height of the convex portion. (10) The scope of the claim is that a negative film for plate making is produced by recording exposure on a photosensitive film using an image signal to which a pattern signal is added using a scanner for plate making, and a plate is produced from this negative film for plate making. Items 7 to 9
The plate-making device described in any of the paragraphs. (11) The plate-making apparatus according to any one of claims 7 to 9, which directly performs engraving and plate-making using an image signal to which a pattern signal is added using an electronic engraving and plate-making machine.