JPS58176668A - Original for preventig copying - Google Patents

Abstract

PURPOSE:To make reproduction of a picture image impossible, by making the total opacity of one or plural sheets of laminated sheets 70-98% so that the color tone of an original is selected with a spectral characteristic and the reflectivity characteristic in the image part and non-image part of the original are made uniform. CONSTITUTION:Adhesive paper 3 coated with an adhesive agent 2 is adhered on backing paper 1 which is subjected to conversion such as waxing. The paper 3 is wood free paper of about 83% opacity. Double sheets 4 are formed by adhering the adhesive paper 3 of the sheets 4 to the front image side of an original 5 whereby an original 6 for preventing copying is formed. The total opacity of the laminated sheets is made 70-98%. The opacity is defined by JISP8138 and is determined by lining a sheet (paper) with white and black standard sheets, measuring the respective reflectivities R1, R2 by using a green filter, and expressing the ratio of R2 with respect to R1 in %.

Description

[Detailed description of the invention] It is related to the manuscript.

In recent years, the spread of various types of copying machines has been remarkable, and confidential documents, etc.
This situation allows for relatively easy duplication.

For this reason, various techniques have been proposed to prevent the copying of confidential documents, etc., but the basic idea is to select the color tone of the document in accordance with the spectral characteristics of the copying machine, and distinguish between image areas and non-image areas of the document. This equalizes the reflectance characteristics between the two parts and makes it impossible to reproduce a single image.

This idea will be explained in more detail.

The spectral characteristics of a copying machine are determined by the spectral energy characteristics of the light source lamp, the spectral transmittance characteristics of the platen glass, the spectral transmittance characteristics of the lens, the spectral reflection characteristics of the mirror, the spectral sensitivity characteristics of the Iμyt body, and the like. For example, the spectrum 1'r gonadal line in one model of XSe electrophotographic copying machine is as shown in FIG.

However, when this copying machine is used to copy an original with a color tone printed with ink having spectral reflectance characteristics as shown in Figure 2, the light incident on the photoreceptor in the non-image area of the original is The groove is obtained by multiplying both characteristic values shown in FIGS. 1 and 2 by each other, and this is shown in FIG. 3.

The area E1 surrounded by the characteristic curve in FIG.
It is the energy (exposure@) that the body receives from the non-image area.

On the other hand, the surface potential characteristics of the photoreceptor with respect to the exposure meter are normally as shown in FIG.
When t is El, the surface potential is vl. On the other hand, if the exposure tilz2 in the image area is zero, the surface potential is v2.

Therefore, the development start potential V. ,V,,>V. If the setting is made so that the non-image area is developed along with the image.

In short, the smaller E is, the easier the non-image area is to be developed.
This makes it difficult to reproduce images.

However, as is clear from the above explanation, this exposure amount E1 is a value that varies depending on the spectral characteristics of the copying machine and the spectral reflectance of the non-image area. In this case, the relationship ■l>vo is not guaranteed.

Assuming that the spectral characteristics of a copying machine are determined only by the spectral energy characteristics of the light source lamp, a copying machine whose light source is a fluorescent lamp with an emission line spectrum in the three-color or green region will Although it is relatively difficult to reproduce the original, it is possible to reproduce the original if it is in +'/color tone tone tone.

By the way, in general, with electrophotographic copying machines, when the spectral reflectance of the image part of the original is set to zero, if the spectral reflectance of the non-image part is less than 30%, it is difficult to copy (that is, it is difficult to decipher the copy). It has been experimentally confirmed that This means that the spectral reflectance of the non-image area is 100
% means that similar results can be obtained even if the spectral reflectance of the image area is set to 70% or more.

Therefore, if the original is subjected to some kind of processing so that the spectral reflectance of the image area is 70% or more, and if the original is legible i-+■, it satisfies the requirements as a copy-protected original.

In view of the above circumstances, the present inventor has developed a manuscript that completely eliminates the problems of the prior art.

It is an object of the present invention to provide a manuscript that cannot be copied, yet is legible, no matter what type of copying machine is used.

The configuration of the present invention will be made clear by the following description.

If a highly opaque sheet is stacked on the surface of the document, the contrast between the image and non-image areas of the document will be reduced.
The spectral reflectances in both parts become close to each other. In fact, by stacking sheets with an opacity of 70% or more, the difference in spectral reflectance n between the image area and the non-image area can be suppressed to less than 30%, and a copy-protected original can be obtained.

In this case, it must be difficult to separate the laminated sheet and the original, and even if the temporary stand can be separated, the image area of the original or the surface layer of the original will peel off and the image area will be lost.

The above-mentioned opacity is defined by J.E. S. p8138, and a sheet (paper) is backed with white and black standard plates, and a colorless filter is used to calculate the reflectance of each of them R, , R. , and the ratio of the latter (R2) to the former (R1) expressed in % is 8.

Next, the results of a copying test according to a specific embodiment of the present invention are as follows.
A comparison with that of conventional technology will be shown.

Example I A double-layered sheet 4 was prepared by pasting a pasting paper 3 (high-quality paper with an opacity of 83%) coated with an adhesive 2 onto a base paper 1 which had been subjected to processing such as ruffling. The adhesive paper 3 of the double sheet 4 was pasted on the image side surface of the original 5 to create a copy-preventing original 6. The image was clear.

Example ■ As mJ sticker paper 3, 90% opacity paper (straw paper)
A manuscript 6 similar to that in Example I was prepared using the following. The image was clear.

Example ■ A colored high-quality paper 10 with an opacity of 80% was layered on the image side surface of the original 11 (no adhesive was used), both sides of which were covered with a polyester film 12, and laminated to create a copy-protected original 13. . The image was so clear.

Comparative example dye: Red type (manufactured by Hodogaya Chemical Co., Ltd., Aizen Prim)
raRed 4] 3) 1) -Mixing ratio 4 Black type (manufactured by Sumitomo Chemical, Direct gaspBl
ack XA) - Mixing ratio 3 Yellow type (Hodogaya Chemical, Direct FastY
yellow Go) -Mixing ratio 9 F- Mix the dye mixture with starch: Dye-starch 10:
0.3) As a 10% aqueous solution, approximately 5
gr/m to prepare transfer paper for preventing re-copying.

A manuscript was created by performing predetermined printing on this transfer paper.

The manuscripts in each of Examples I to (2) and Comparative Example were copied using various types of electrophotographic copying machines. Somasu ○ mark...
Good △ mark: Fairly good In the comparative example,
FX7200 with spectral characteristics in the long wavelength spectral region
．． 4000.3200, the copy was legible.

In the above embodiment, one sheet of adhesive paper 3 and one sheet of colored wood-free paper are laminated on the surface of the manuscript, but if multiple sheets are laminated,
It may be possible to obtain a desired degree of opacity.

As described above, according to the present invention, it is possible to prevent copying in various types of copying machines, and in addition, it is easy to prepare originals and is inexpensive.

[Brief explanation of drawings]

Figure 1 is a graph showing an example of the spectral characteristic curve of an electrophotographic copying machine, Figure 2 is a graph showing an example of the spectral reflectance characteristic of ink, and Figure 3 is a graph showing an example of the spectral reflectance characteristic of an electrophotographic copying machine. A graph showing the reflectance)×(spectral sensitivity of the electrophotographic copying machine shown in FIG. 1) curve, FIG. 4 is a graph showing the photosensitivity characteristic curve of the photoreceptor, and FIG. FIG. 6 is an explanatory diagram showing a method for creating a copy-protected original according to the embodiment described above, and FIG. 7 is a diagram showing a method for creating a copy-protected original according to another embodiment of the present invention. FIG. 8 is a sectional view of the same copy-protected document. l...Base paper, 2...Adhesive, 3...Packing paper, 4...
...Double sheet, 5.. Original, 6.. Copy-protected original, 10.. Colored high-quality paper, 11.. Original, 12.. Polyester film, 13.. Copy-protected original. Agent: Patent attorney Nozomi Ehara and 1 other person: u
l1y6jj E1 Atsushi 5
Figure r'- Figure 6

Claims (1)

[Claims] 1. A copy-preventing original, characterized in that eleven or more sheets are laminated and integrated on the original surface, and the total opacity of the tank layer sheets is 70 to 98%.