JPS63262675A - Confidential document producing method - Google Patents

Abstract

PURPOSE:To produce a confidentiality holding document by which true information is difficult to leak, by forming the true information by a toner of the same color as that of transfer paper on one face of the transfer paper, forming the second information by a toner of a different color from thereon, and also, forming the third information on the other face of the transfer paper. CONSTITUTION:On an original placing table, the first original (true information) is set and copy is executed, and on transfer paper, a white toner image corresponding to an original image is formed. As for an obtained copy, an image is formed by a white toner on white transfer paper, and an image information part becomes difficult to be decoded. This copy is further used as the transfer paper, and the second original (dummy information) is copied by a coloring toner (black toner). Also, the other face of the transfer paper on which the first and the second information are formed is used as the transfer surface, and the third original (dummy information) is copied. As for the toner used at the time of this copy, desirably, the toner having a high contrast color to the transfer paper is used. In such a way, a confidential document can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of creating confidential documents using an electrophotographic copying machine.

(Prior Art and its Problems) Recent improvements in the performance of copying machines and their widespread use have been remarkable, and anyone can now easily obtain large quantities of faithful copies of originals. Under these circumstances, materials that should not be copied or even important documents such as various certificates are copied, or copies of documents that have been partially amended are judged to be the original image information and transmitted. There is a risk that you may be

For example, the following methods have been considered as means to prevent this.

(1) A method of coloring transfer paper with dye or pigment to absorb irradiated light equally in non-image areas and image areas, eliminating image exposure on the photoreceptor and preventing re-copying (Japanese Patent Laid-Open No. 54-52
538).

(2) A method for preventing copying in which a camouflage pattern is applied to transfer paper and images are formed in different colors on the paper, so that when copying, the ground pattern is also copied, making it difficult to read.
/1.7).

(3) A method in which a fluorescent material is present on the surface of a document, irradiated with excitation light, and the presence or absence of luminescence is detected and the copying operation is stopped (
JP-A-58-184967).

However, according to method (1), the manufacturing process becomes complicated and the documents produced become expensive because the transfer paper itself is colored with a small amount of dye or pigment (either one or the other) during or after the paper making process. In addition, creating a copy-protected document using method (2) is time-consuming and costly because a camouflage pattern with equal reflectance is created in the non-image area and the image area using printing methods or other methods. It has the disadvantage of being expensive.

Furthermore, in (3), there are safety and health problems due to the use of fluorescent substances, and in addition, in order to stop the copying operation, a detection means and a control mechanism for stopping it are required, and a special copying machine is required. Applicable only to machines.

In addition, any method completely prevents re-copying,
It is difficult to create a document that is sufficiently visible to the naked eye, and although it is possible to prevent the document from discharging by making it impossible to re-copy, if the document itself is read, it is difficult to create a document that can be read with the naked eye. However, secrets are leaked.

(Object of the Invention) The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a method for creating confidential documents without requiring any special equipment or control mechanism. be.

Another object of the present invention is to provide a method for confidential documents with extremely high security-keeping ability. Yet another object of the present invention is to provide a method that completely prevents the effects of discharge on document content. Still another object of the present invention is to provide a confidential document creation method that allows document contents to be easily and clearly reproduced.

(Structure of the Invention) In order to achieve the above object, the present invention has the following features:
Forming a toner image corresponding to the first document using toner or transparent toner of the same color as the transfer paper, and forming a toner image corresponding to the second document image using toner of a different color from the first image in any order. A confidential document is created by forming a toner image corresponding to the third original image on the other side of the transfer paper using toner of a different color from that of the transfer paper.

(Example) Examples of the present invention will be described in detail below.

The copying machine used in the present invention is a commonly used copying machine and does not have any special mechanism or control means, but the developing device contains toner of each color and is constructed to be replaceable. For this reason, it is desirable that the developing device be integrated into a unit. Furthermore, it is preferable to use a multi-color developing system copier which has two developing units in the copier and each unit is filled with toner of a desired color to produce any color depending on the copying purpose or original image. used.

When performing the copying method of the present invention, for example, a developing device containing white toner is attached to the main body of the copying machine, and ordinary white transfer paper is used as the transfer paper. A first original (true information) is set on the original table and copied, and a white toner image corresponding to the original image is formed on the transfer paper. The resulting copy has an image formed with white toner on white transfer paper, making the image information portion difficult to decipher. This copy is further used as transfer paper to create a second manuscript (dummy information).
Place the document on the original table and copy using colored toner (black toner in this case). On the transfer paper, a second image is formed with black toner on top of the first image formed with white toner, and when a third party other than the information provider and recipient obtains this copy, Unless you are very careful, only the information on the second document, which is dummy information, will be read.

Further, the other side of the transfer paper on which the first information and the second information are formed is used as a transfer surface, and a third original (dummy information) is transferred.
Place the document on the original table and make copies. When making this copy,
The toner used may be a colored toner of a color different from that of the transfer paper, but preferably a toner of a color having a high contrast with the transfer paper is used. The second information is a passive dummy image that makes it difficult to read the true information hidden on the surface, while the third information formed on the other surface is
It is an aggressive dummy statue designed to draw the attention of the person who holds it. Therefore, the second information is formed by trademarks, patterns, etc., and the third information is selected from character information, etc. When we have this information, we focus on the content of the third information, which is text information, and do not pay attention to the second information, such as the pattern.
There is no risk that the first information, which is the true information obscured by the second information, will be decoded.

If the true information is to be read from this confidential document, the recipient of this copy must use toner of the same color (
In this case, a black aqueous ink may be applied to the second image forming surface. Since most of the components of toner are resin, water-based ink does not repel and adhere to the white and black parts where the first and second information are formed, and only the non-image parts are colored. Ru. Since the information of the first document, which is the true information, is formed with white toner, it stands out in white from the information area colored with black water-based ink and can be visually observed.

On the other hand, since the information on the second document, which is dummy information, is formed using black toner, even if the water-based ink is repelled, the information on the second document becomes invisible together with the black background.

That is, by applying black water-based ink, the easily visible visible image is reversed from the second information to the first information. It is desirable to uniformly apply a small amount of water-based ink to the entire surface, and application by means such as a roller, brush, or spray is employed.

In the embodiment described above, a white toner image corresponding to the first original image was formed on the transfer paper, and then a colored toner image corresponding to the second original image was formed on the transfer paper, but the toner images are formed in this order. When the first image, which is the true information, is reproduced,
When a white toner image and a colored toner image overlap, the white I/toner is hidden by the colored toner, making it difficult to read the true information. In such a case, the order in which the first image and second image are formed may be reversed. First, a colored toner image corresponding to the second original image (dummy information) is formed on transfer paper,
Next, a white toner image corresponding to the first original image (true information) is formed. Even if the colored toner is covered with a white toner having a weak hiding power, the dummy image formed with the colored I/toner will not be hidden, and the existence of the confidential document will not be confirmed.

Since most ordinary transfer papers are white, white toner is essential in the method of the present invention, and therefore white toner will be described below.

Since the white toner used in the present invention does not need to cover the base, there is no need to use a material with excellent hiding power. To make white toner, binder resin, white colorant,
Also, a device mixture thereof such as a charge control agent and a mold release agent is used, and the composition thereof is not particularly limited as long as it does not adversely affect the color tone of the colorants 1 to 1.

The weight ratio of the white colorant and the binder resin is preferably 0 to 35 parts by weight of the white colorant to 100 parts of the binder resin.
If the amount ratio of the white colorant is greater than this, the triboelectric charging characteristics of the toner will deteriorate, and furthermore, spent toner will be more likely to be generated, resulting in a shortened lifespan as a developer.

As the binder resin used in this toner, various resin materials conventionally known as toner binder resins for electrophotography are used. For example, polystyrene, polystyrene
Styrenic copolymers such as butadiene copolymers, styrene-acrylic copolymers, ethylene copolymers such as polyethylene, polyethylene-vinyl acetate copolymers, polyethylene-vinyl alcohol copolymers, phenolic resins, epoxy-based resin, allyl phthalate resin, polyamide resin, polyester resin, maleic acid resin, etc.

The white coloring agents used in this toner include zinc white,
Examples include titanium oxide, tin oxide, antimony white, zinc sulfide, zinc oxide, barium carbonate, clay, silica, white carbon, cruzi, alumina, and pallite.

As the charge control agent used in this toner, a known colorless or white one is used as it does not adversely affect the color tone of the white toner. For the purpose of positive charge control, organic compounds having basic nitrogen atoms, such as basic dyes, aminopyrine, pyrimidine compounds, polynuclear polyamine compounds, aminosilanes, or fillers surface-treated with these, are used. For the purpose of controlling negative charge, a carboxyl group-containing compound such as a metal chelate of alkyl salicylic acid is used. These charge control agents are preferably used in an amount of 1 to 10% by weight per toner.

Further, examples of the release agent used in this toner include silicone oil, low molecular weight olefin resins, and various waxes.

The white toner is obtained by melt-kneading the above components, cooling them, and then crushing and classifying the mixture. It can also be obtained by dispersing toner ingredients in a resin solution and then spray granulating the resultant.

Clear toners are also suitably used in the method of the invention. Transparent toners 1 to 1 are prepared without adding a colorant in the normal toner manufacturing process, but preferably the above-mentioned white l
・It is best to omit the addition of white coloring agents during the manufacturing process. As the binder resin, a highly transparent resin is selected, and as the charge control agent, a colorless one or a white one with weak hiding power is selected. Furthermore, even if a colored charge control agent is used after being pulverized, its hiding power will be weak.

A developing device containing this transparent toner is attached to the main body of the copying machine, and an image corresponding to the original image is transferred and fixed using the transparent toner. Even if transparent toner is transferred to white transfer paper, the image cannot be seen with the naked eye and can only be recognized as completely white paper. If a colored water-based ink is applied to this copy, only the toner image portion will not be colored, and the paper base will be transmitted through the portion to which the transparent toner has been fixed, resulting in a white image.

In this embodiment, the image corresponding to the first document was formed using white or transparent toner, but the color of the toner is not limited to this, and any toner may be used as long as it is the same color as the transfer paper.

Furthermore, transfer paper of any color can be used as long as it uses transparent toner. It is desirable to use a toner with a high contrast color to the second original (used in the first original).

Further, the aqueous ink may be dark enough to make it difficult to distinguish the color of the second toner and the color of the transfer paper in the non-image area.

(Effects of the Invention) As explained above, according to the present invention, true joy is formed on one side of the transfer paper using toner of the same color as the transfer paper, and second information is formed on top of that using toner of a different color. Furthermore, by forming third information on the other side of the transfer paper, it is possible to create a confidentiality document in which true information is unlikely to be leaked.

As a result, even if a third party other than the information provider and recipient obtains this information, only the dummy information (second and third information) will be read, thereby preventing the true information from leaking. In addition, by using patterns as the second information and character information as the third information, it is possible to maintain the confidentiality of true information in order to actively draw the eyes of third parties to other aspects of true information formation. becomes extremely high. Furthermore, even if this copy is amended, it will still be able to convey true information.

Claims (1)

[Claims] On one side of the transfer paper, a toner image corresponding to the first document is formed using toner of the same color as the transfer paper or transparent toner, and a toner image corresponding to the second document image is formed using toner of a different color from the first image. A method for creating a confidential document, characterized in that formation is performed in an arbitrary order, and a toner image corresponding to a third original image is formed on the other side of the transfer paper using toner of a different color from that of the transfer paper.