JPH01285979A - Copyingproof recorded matter - Google Patents

Abstract

PURPOSE:To make recorded information hardly readable or unreadable from a copy by coloring it least either of a recording surface and recording information with dots to provide a difference in copying density between the recording surface and an information recording part to a specific range. CONSTITUTION:Copying reproducibility is poor and the information from the copy is substantially illegible according to the range in the difference between the copy densities if characters, symbols, etc., are formed by fine points, i.e., dots at the time of copying by an electrophotographic copying machine. At least either of the recording surface and recording information is thus colored by the dots to provide the difference in the copying densities between the recording surface and the information recording part to a -0.3-0.2 range at the time of recording the information on the recording surface in such a manner. The recorded information is distinctly visible by naked eyes but the dot images are obscurely copied by an electrophotographic type copying machine. The information recorded from the copy is thus hardly readable or unreadable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to copy protection 11-recorded materials. Regarding a certain recorded material.

(Prior art) Conventionally, with the development of copying technology, it has become easy to copy all kinds of things, and for example, problems such as counterfeiting of expensive books, securities, banknotes, etc., duplication or secret leakage of important documents, secret documents, etc. problems occur frequently.

In order to prevent such forgery and secret leakage, copy prevention sheets have been proposed, but the conventional copy protection 11-
The sheet is, for example, a ↓L material receipt such as M, with a colored surface, and the recorded information can be read with the naked eye, but when it is copied with an electrophotographic copying machine, the entire surface is copied in black. , the copied characters become difficult to read or become illegible.

(Problem to be solved by the invention) The above-mentioned conventional anti-copying sheet has a colored surface, and the coloring absorbs the light source light from an electrophotographic copying machine, making it similar to the absorption by recorded characters, etc. This makes it difficult to read the characters, etc. on the copy, so the colored portion is colored, for example, dark brown so that it can absorb most of the light from the light source.

Therefore, there is a drawback that the characters recorded therein using black ink or the like are extremely difficult to read with the naked eye.

Therefore, there is a need for the development of a copy prevention technique that can prevent copying, but also allows recorded information to be easily read with the naked eye.

Accordingly, one object of the present invention is to provide a recorded material that can be sufficiently prevented from being copied without excessively coloring the recording surface.

(Means for Solving the Problems) The above objects of the present invention are achieved by the following present invention.

That is, the present invention is characterized in that in a recorded article in which information is recorded on a recording surface, the difference between the recorded information and the copy density of at least line information on the recording surface is in the range of -0.3 to 0.2. This is a mutual defense record.

(Function) When recording information on the recording surface, at least one of the recording surface and the recorded information is colored with halftone dots, and the difference in copy density between the recording surface and the information recording area is set to -0.3 to 0.2. By setting the range, the recorded information can be clearly read with the naked eye, or because the halftone image is copied unclearly with an electrophotographic copying machine, it is difficult or impossible to read the recorded information from the copy. becomes.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments of the present invention.

The recording surface used in the present invention may be one normally used for numerical recording (for example, printing, printing, writing, etc.) such as general paper, plastic film, synthetic paper, etc.
Not particularly limited. In the present invention, the term "recording surface" refers to an area of recording paper on which no information is recorded.

The method for recording information consisting of characters and symbols on the recording surface is not particularly limited and may be any method such as gravure printing, offset printing, letterpress printing, flexo printing, various printers, handwriting, etc.

Also, any ink suitable for these methods can be used. In the present invention, the term "information recording section" refers to an area in which information such as characters and symbols is recorded.

The main feature of the present invention is to take advantage of the fact that when characters, symbols, etc. are formed by fine dots, that is, halftone dots, copying reproducibility is poor when those characters, symbols, etc. are copied using an electronic copying machine. .

For example, when the recording surface is white like paper, if you want to blank out information such as characters or symbols, that is, color only the surroundings of the characters or symbols, and make the white background into the shape of the characters or symbols, If the above coloring is done using halftone dots, even if the recorded information (white background) is copied using an electronic copying machine (mainly black and white), the boundary between the white text and the surrounding halftone colored areas will be blurred. , the shapes of characters, symbols, etc. become unclear, making them difficult or impossible to read.

Although such a phenomenon occurs to varying degrees in all halftone recorded materials, in the present invention, the difference between the copy density of the recording surface and the copy density of the information recording portion such as characters and symbols is kept within a specific range. It has been found that this makes the copies difficult or impossible to read. The difference in copy density that can prevent copying is -0.3 to 0.2, preferably 10.15 to 0.
．． It is 1. Note that the above example is one example of the present invention, and the recording surface is not limited to white, but may be colored in any color.

In the present invention, the copy density of the recording surface refers to the area average density obtained by measuring the density of the area of the recording surface that does not contain information such as characters or symbols.On the other hand, the copy density of the information recording area is This is the area average density obtained by measuring with a densitometer a plain screen or duplex area formed under the same conditions as the area where characters, symbols, etc. are formed.

Therefore, the recording surface in the above example has the area average density of the colored area with halftone dots, and the copy density of the information recording area is the area average density of the white area. For example, since the copy density of a white background such as ordinary paper is approximately 0 to 0.1, the copy density of the halftone colored portion may be set to a range of 0.3 to 0.4 in the above example.

It becomes difficult to read information from a copy within such a range of difference in copy density, and in particular, the closer the difference between the two approaches to 0, the more difficult it becomes to read information. A typical example where the difference is 0 or close to 0 is when the recording surface and the information recording section are both colored in different colors.

Further, as another example of the present invention, (+) J: A mode in which information such as characters and symbols is formed by halftone dots, contrary to the north side, (2) A white part by halftone dots is formed as a halftone colored part. (3) A method in which areas other than the information recording area are colored with ink or halftone dots of different colors, and (3) an aspect in which the information recording area is colored with halftone dots in a different color. The principle is the same as above.

As a method for forming halftone dots in the recorded matter of the present invention as described above, a halftone printing plate is formed from a manuscript by a halftone plate making method widely used in the conventional printing technology field, and this plate is used to form a halftone dot on the recording surface or information. It can be easily formed by printing the recording section. For example, a printed version of a document created in Japanese type or the like can be obtained by changing its shading to the size of dots through a mesh screen or contact screen.

For the purpose of the present invention, the dot size is preferably 50 to 300 L (line number per inch liter) and the dot area (surface 82 to which ink is attached) is 10 to 98%, preferably 2.
It is obtained by a halftone screen ranging from 0 to 90%.

Furthermore, when printing the recording surface and/or the information recording section, it goes without saying that the density and adhesion amount of the printing ink must be adjusted in order to keep the copying density of both areas within the printing range.

In addition, when coloring the recording surface, these colors can be done using flat mesh,
It goes without saying that patterns such as gradated plain mesh, background patterns, etc. may also be used.

(Effects) According to the present invention as described above, when recording information on a recording surface, at least one of the recording surface and the recorded information is colored with halftone dots, and the copy density between the recording surface and the information recording section is improved. The difference between -
By setting it in the range of 0.3 to 0.2, the recorded information can be clearly read with the naked eye, but the recorded information becomes difficult or impossible to read from a copy.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 Using a manuscript recording information consisting of No. 4 typeface, a plate was made using a photoengraving method using a screen with a line count of 133L and a halftone dot of 80% at an angle of 15°, and a screen with white characters was created. A printed version was created. Using this plate and the following ink, offset printing was performed on an art background with an amount of ink that gave a blue filter density of 0.59 in the solid printed area, to obtain a printed white character print with a green recording surface and white characters.

Cyanine blue 2.4 parts qF Disazo yellow 2.8 parts 1 part titanium oxide
19.2 parts, 11 parts, manganese ocdylate (manganese content: 8%), 0.5 parts, 11 parts, varnish, 75.1 parts, 1 part, part by weight, 75.1 parts, 1 part by weight, 1 part by weight.Copying density of the ground (halftone dot colored part) of the above printed matter (Maches@RD-9)
18 (measured using a densitometer, hereinafter the same) is 0.34, while the copy density of white text (white side of art paper) is 0.09, and the difference is -0.25. Ta.

The characters on the above printed matter were easily legible with the naked eye, but this was done using an electrophotographic copying machine (lillJIXliR).
OX 3870), the characters were blurry and difficult to read.

Example 2 Using a manuscript recording information consisting of 20 points of type, a plate was made using a photolithography method using a screen with a line count of 175L and a halftone dot of 70% at an angle of 75'', and the characters were expressed as halftone dots. A halftone printing plate was created. Using this plate, offset printing was performed on an art background using the following ink with an amount of ink that gave a black filter density of 0.42 in the solid printing area.
A halftone print with a white recording surface and black characters was obtained.

Carbon black 5.6 parts by weight Calcium carbonate 20.0 parts by weight Manganese octylate (manganese content 8%) 0.5 parts by weight Varnish 73.9 parts by weight The copy density of the background of the above print (white side of art paper) is On the other hand, the copy density of the halftone dot character area (black) was 0.27, and the difference therebetween was 0.19.

The characters on the above printed matter were easily legible with the naked eye, but this was done using an electrophotographic copying machine (F[IJIXEROX
3870), some of the characters were missing and it was difficult to read.

Example 3 A halftone printing plate in which characters are expressed as halftone dots is made by photolithography using a manuscript recording information consisting of 20 points of type, using a screen with a line count of 150L and halftone dots of 50%. It was created. Using this plate and the following ink, offset printing was performed on an art background with an ink star with a black filter density of 1.72 in the solid printed area to obtain halftone dot prints with black characters.

Carbon black 15.6 parts by weight Calcium carbonate 10.0 parts by weight Manganese octylate (
Manganese content: 8%) 05 parts by weight Varnish 73.9 parts by weight Next, using the same original as above, a plate was made by photolithography using a screen with 15 OL lines and 80% halftone dots at an angle of 45 degrees, and the letters were printed. created a shaded printing plate with the colors removed. Using this plate and the following ink, we matched it with the above printed matter and overlaid it with offset printing with ink (■) with a blue filter density of 0.58 in the solid printed area to obtain a colored printed matter in which the recording surface was green and the letters were black. Ta.

Cyanine blue 2.4 parts by weight Disazo yellow 2.8 parts by weight Titanium oxide
19.2 parts by weight Manganese octylate (manganese content 8%) 0.5 parts by weight varnish 75.1 parts by weight The copy density of the background (green) of the above print is 0.36, while the halftone letters The copy density of the part (black) was 0.45, and the difference therebetween was 0.09.

The characters on the above printed matter were easily legible with the naked eye, but this was done using an electrophotographic copying machine (FLIJIXIERO).
The copy obtained by copying with X 3870) was difficult to read because some of the characters were missing and blurred.

Example 4 Using a manuscript recording information consisting of No. 4 typeface, a plate was made using a photoengraving method using a screen with a line count of 133L and halftone dots of 80% at an angle of 15 degrees, and the letters and halftone dots were removed. A printed version was created. Using this plate and the following ink, offset printing was performed on an art background with an amount of ink that gave a black filter density of 0.45 in the solid printing area to obtain a printed matter with a black recording surface. Carbon black: 5.6 parts by weight Calcium carbonate: 1000 parts by weight Part: Manganese octylate (manganese content 8%): 0.5 ffl: Varnish: 83.7 parts: Next, using the same manuscript as above, a plate was made by photolithography to prepare a printing plate without shading. Using this plate and the following ink, align it with the above printed matter, overlap and offset print with an ink amount that makes the blue filter density of the solid printing part 0.42,
A printed matter with a black recording surface and green characters was obtained.

Cyanine Blue 2.4 parts by weight Disazo Yellow 2, 8-jl j, 1-1 parts Titanium oxide 19.2 parts by weight Manganese octylate (manganese content 8%) 0.5 parts,! jY part varnish 75.1 layer fJt part The copy density of the background (black) of the above printed matter is 0.46, on the other hand,
The copy density of the text portion (green) was 0.34, and the difference therebetween was -0.12.

It has been said that the characters on the above printed matter can be easily read with the naked eye, but this was done using an electrophotographic copying machine (FUJ lX1iRO).
The copy obtained by copying with X 3870) was difficult to read as some of the characters were missing.

Example 5 A color cutting plate without shading was prepared by a photolithography method using a manuscript recording information consisting of No. 4 typeface. Using this plate and process color TC-80 yellow, offset printing was performed on an art background with an amount of ink such that the yellow filter density of the solid printing area was 0.8, to obtain a yellow blank print on the recording side.

Next, using the same manuscript as above, plate making was performed using a screen with a line count of 15 OL and a halftone dot of 70% at an angle of 15° using a photolithography method to create a halftone printing plate with characters composed of halftone dots. . Using this plate and the following ink, overlapping offset printing was carried out with an amount of ink that matched the above printed matter and the black filter density of the solid printed area was 0.42, to obtain a printed matter with a yellow recording surface and black characters.

Carbon black 5.6 parts by weight Calcium carbonate 200 parts by weight Manganese octylate (manganese content 8%) 0.5 parts by weight 1 part by weight Varnish 73.9 parts by weight 0.17,
On the other hand, the copy density of halftone letters (black) is 0.34,
The difference was 0.17.

The characters on the above printed matter were easily legible with the naked eye, but this was done using an electrophotographic copying machine (FU, IIXEROX).
3870), some of the text information is missing and difficult to read.

Claims (4)

[Claims] (1) In a recorded product in which information is recorded on a recording surface, at least one of the recorded information and the recording surface is colored with halftone dots, and the difference between the copy density of the recording surface and the copy density of the recorded information is -0.3 to A photocopy-proof recorded material, characterized in that it is in the range of 0.2. (2) The copy protection recorded material according to claim 1, wherein the information is recorded as cut-out characters, and the periphery of the characters is colored with halftone dots. (3) The copy protection recorded material according to claim 1, wherein the information is recorded on the recording surface as a set of halftone dots. (4) The copy protection recorded material according to claim 1, wherein the information is formed by colored characters, and at least one of the recording surface or the characters is formed by halftone dots.