JP2007109147A - Code printing apparatus, code printing method, and printing medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively cancel a part of code data. <P>SOLUTION: The code printing apparatus comprises an image forming unit 41K to form a K toner image, image forming units 41I<SB>1</SB>, 41I<SB>2</SB>, and 41I<SB>3</SB>to form an invisible toner image, an intermediate transfer belt 46 to accumulate and convey the toner images, a secondary transfer device 410 to secondarily transfer the toner image onto a medium, and a fixing device 440 to fix the toner image on the medium. In the image forming units 41I<SB>1</SB>, 41I<SB>2</SB>, and 41I<SB>3</SB>, the toner image is formed respectively using an invisible toner including material to be decomposed by light of a wavelength λ1, an invisible toner including material to be decomposed by light of a wavelength λ2, and an invisible toner including no material to be decomposed by light, thereby selectively canceling code data by light after printing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus such as a printer or a copying machine, and more particularly to a code printing apparatus or the like that prints a code obtained by encoding predetermined information.

2. Description of the Related Art In recent years, various so-called paper-based tablet systems have been devised in which writing information is reflected in an electronic document when the electronic document is printed. In order to realize such a paper-based tablet system, it is necessary to associate an electronic document with a printed matter. For example, a medium code is printed in advance using a code symbol, and the electronic document is recorded on the medium. Such association is possible by reading this code symbol at the same time as printing.
By the way, as a code symbol, a machine-readable symbol such as a barcode or a two-dimensional code is generally used, but the amount of information that can be encoded in these symbols is limited. Therefore, when encoding codes to be allocated to a large amount of media used in daily work, it is conceivable that code symbols are insufficient.

  Accordingly, in order to effectively use the code symbols, it has been proposed to discard the code symbols assigned to the medium (see, for example, Patent Document 1). In Patent Document 1, as an example of a specific code symbol discarding method, easy-to-determine characters such as “x” and “unusable” are printed on an already printed medium. It has been. It is also described that information can be erased by heating the medium to an appropriate temperature when a thermoreversible coloring material typified by leuco dye is used as the medium.

JP 2003-150585 A (6th and 7th pages, FIG. 6)

Thus, it has been conventionally considered to discard the code information assigned to the medium.
However, Patent Document 1 has a problem that even if all the code information on the medium can be erased, a part of the code information cannot be selectively discarded and reused.
There is also a problem that it is not possible to continue using the code information on the medium without erasing only a part of the code information.

For example, by discarding the code of the medium, the association with the electronic document is canceled, but if the code indicating the position on the medium remains, the handwritten characters using a dedicated pen are used as a memo paper that can be digitized It is possible. In addition, there is a case where additional writing by hand cannot be performed, but it is desired to keep the association with the electronic document as it is.
In response to such a request, the technique of Patent Document 1 did not provide any effective solution.

The present invention has been made to solve the technical problems as described above, and an object thereof is to enable a part of code information to be selectively discarded.
Another object of the present invention is to allow a part of code information to remain and be used as it is.

For this purpose, in the present invention, in a code printing apparatus having a plurality of code image printing means, reading of the code printed by at least one code image printing means is restricted by light (for example, it becomes impossible). ) That is, the code printing apparatus according to the present invention prints a code image in which predetermined information is readable, and the first portion of the code image has an absorption curve changed by light of a specific wavelength. The first code image printing means for printing using the first recording material that restricts the reading of the image and the second portion of the code image are different from the first recording material in terms of the characteristics relating to the change in the absorption curve due to light. Second code image printing means for printing using the second recording material.
Here, the second recording material may be one in which the absorption curve is not changed by light and the reading of information is not restricted, or the absorption curve is changed by light having a wavelength different from the specific wavelength, thereby reading information. May be limited.

  The present invention also provides a code printing apparatus that prints a code image with two recording materials that can read information at different wavelengths. In that case, the code printing apparatus of the present invention prints a code image in which predetermined information is readable so that the first portion of the code image is read with light of the first wavelength. The first code image printing means for printing using the first recording material and the second portion of the code image printed using the second recording material for reading information with the light of the second wavelength Second code image printing means.

  Furthermore, the present invention can also be understood as a code printing method. In that case, the code printing method of the present invention prints a code image including the identification information of the medium and the position information in the medium so as to be optically readable, and corresponds to the identification information in the code image. Printing a portion to be printed using the first invisible toner, and printing a portion corresponding to the position information in the code image using the second invisible toner having optical characteristics different from those of the first invisible toner. Steps.

  On the other hand, the present invention can also be understood as a print medium that is a result of printing. In this case, the print medium of the present invention is printed with a code image in which predetermined information is imaged so that the information can be read, and the code image changes its absorption curve due to light of a specific wavelength and restricts reading of information. The first portion printed using the first recording material, and the second portion printed using the second recording material having characteristics relating to the change in the absorption curve due to light different from those of the first recording material Including.

  According to the present invention, a part of code information can be selectively discarded.

The best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described below in detail with reference to the accompanying drawings.
FIG. 1 shows an example of the configuration of a system to which the present embodiment is applied. In this system, at least a terminal device 100 that instructs to print an electronic document, a document repository 200 that stores the electronic document, and an image forming apparatus 400 that superimposes a code image on the image of the electronic document and prints the network 900. It is configured by being connected. The system also includes a printed material 500 output from the image forming apparatus 400 and a pen device 600 that records characters or graphics on the printed material 500 and reads the trajectory of the characters or graphics. Further, a terminal device 700 that displays the locus received from the pen device 600 and the electronic document acquired from the document repository 200 in an overlapping manner is also connected to the network 900.

The outline of the operation of this system will be described below.
First, the terminal device 100 acquires an electronic document to be printed from the document repository 200 (A). Then, it instructs the image forming apparatus 400 to print this electronic document (B). At this time, the terminal device 100 designates a printing attribute that is a parameter related to printing. As in normal printing, the print attributes include paper size, orientation, reduction / enlargement, double-sided printing, N-up (printing in which N pages of an electronic document are allocated within one page of paper), and the like. In addition, regarding the code image, designation of an area in which the code image is to be printed may be included.
When receiving the instruction to print the electronic document, the image forming apparatus 400 prints an image obtained by superimposing the code image on the image of the electronic document on a medium such as paper, and outputs a printed matter 500 (C). In this case, the code image is an image of the identification code corresponding to the identification information and the position code corresponding to the position information. Alternatively, it may be an image including additional information which is other information.

Here, as the identification information, information for uniquely identifying each medium can be adopted. For example, it may be information obtained by combining the identification number of the image forming apparatus 400 and the serial number of printing of the medium in the image forming apparatus 400 or the date and time of printing. It may be managed information. Alternatively, information that uniquely identifies an electronic document printed on a medium may be adopted as identification information instead of information that uniquely identifies each medium.
The position information is information for specifying the coordinate position (X coordinate, Y coordinate) on each medium. For example, it is conceivable to express coordinates in a coordinate system set by taking the upper left point of the medium as the origin, taking the X axis in the right direction of the medium and the Y axis in the lower direction. Alternatively, a plurality of coordinate systems may be set on one medium, such as providing a coordinate system for each region instead of one coordinate system.
Further, the additional information includes the identification information of the user who issued the print instruction, information about whether copying is prohibited, or the like.

  In addition, the image forming apparatus 400 forms the code image as an invisible image using an invisible toner whose infrared light absorption rate is equal to or higher than a certain reference. On the other hand, it is preferable that the document image of the electronic document is formed as a visible image using a visible toner having an infrared light absorption rate which is equal to or lower than a certain reference. The difference in the absorption rate of infrared light between the toner used for forming the code image and the toner used for forming the document image is that the reading accuracy when reading the code image by irradiating the infrared light is increased. This is to ensure. In this specification, the description is based on the premise that the code image is read by infrared light irradiation, but the code image may be read by ultraviolet light.

Thereafter, it is assumed that the user has written characters or figures on the printed material 500 using the pen device 600 (D). Thereby, the pen device 600 inputs a code image by irradiating the printed matter 500 with infrared light and detecting the reflected light. Then, information is acquired or generated from the code image, and the information is transmitted to the terminal device 700 via wired communication or wireless communication (E). The information transmitted here includes, for example, identification information of the printed matter 500 and position information of characters or figures written on the printed matter 500. Alternatively, the position information may be transmitted as trajectory information obtained by connecting the position information of characters or figures at a certain time.
Thereafter, based on the identification information received from the pen device 600, the terminal device 700 acquires an electronic document that is a source of the document image printed on the printed material 500 from the document repository 200 (F). Then, the electronic document acquired from the document repository 200 and the information acquired from the pen device 600 are superimposed and displayed.

By the way, when the identification information received from the pen device 600 is information that uniquely identifies each medium, in order to be able to acquire an electronic document based on this identification information, the identification information and the electronic document It is necessary to manage the correspondence. In FIG. 1, it is not clearly shown where to manage this correspondence, but it may be managed where it can be accessed from the terminal device 700. For example, the document repository 200 or the image forming apparatus 400 may be used. When the identification information received from the pen device 600 is information that uniquely identifies the electronic document printed on the medium, the electronic document can be acquired without referring to such correspondence.
Further, when the trajectory information is received from the pen device 600, the trajectory information is displayed superimposed on the position on the electronic document corresponding to the writing position on the printed matter 500. This is because the code image read by the pen device 600 includes writing position information, and the corresponding position in the display image of the electronic document can be specified from the information.

Although the system to which the present embodiment is applied has been described above, such a configuration is merely an example. For example, the function of the image processing unit that superimposes the document image and the code image in the image forming apparatus 400 may be realized by the terminal device 100, the document repository 200, or another device. Further, the document repository 200 may be in the terminal device 100. Furthermore, the terminal device 100 and the terminal device 700 may be the same terminal device.
In this specification, the term “electronic document” is used, but this does not mean only data obtained by digitizing a “document” including text. For example, “electronic document” includes image data such as pictures, photographs, figures, etc. (regardless of raster data or vector data) and other printable electronic data.

  2A to 2C are diagrams for explaining the above-described code image. FIG. 2A schematically shows a two-dimensional code array formed as an invisible image. FIG. 2B is an enlarged view of the two-dimensional code which is one unit of the two-dimensional code array in FIG. Further, FIG. 2C is a diagram for explaining a pattern image of backslash “\” and slash “/”.

  In the present embodiment, the code images shown in FIGS. 2A to 2C have a maximum absorption rate of, for example, 7% or less in the visible light region (400 nm to 700 nm), and the near infrared region (800 nm to 1000 nm). For example, an invisible toner having an absorptance of 30% or more. The invisible toner has an average dispersion diameter in the range of 100 nm to 600 nm in order to enhance the near infrared light absorption capability necessary for machine reading of an image. Here, “visible” and “invisible” are not related to whether they can be recognized visually. “Visible” and “invisible” are distinguished depending on whether or not an image formed on a printed medium can be recognized by the presence or absence of color development due to absorption of a specific wavelength in the visible light region. Further, “invisible” includes those that have some color developability due to absorption of a specific wavelength in the visible light region but are difficult to recognize with human eyes.

  In addition, the code image is formed as an invisible image that can be machine-readed and decoded by infrared light irradiation stably over a long period of time and can record information at high density. Furthermore, it is preferable that the image is an invisible image that can be provided in an arbitrary area regardless of the area where the visible image on the medium surface that outputs the image is provided. Furthermore, for example, an invisible image that can be recognized by a difference in gloss when visually observed is more preferable. For example, an invisible image is formed on the entire surface of the medium (paper surface) in accordance with the size of the medium to be printed. However, “entire surface” does not mean to include all four corners of the sheet. In an apparatus such as an electrophotographic system, the area around the paper surface is usually a non-printable range, and therefore it is not necessary to print an invisible image in such a range.

  The two-dimensional code shown in FIG. 2B includes an area where a position code indicating a coordinate position on the medium is stored, and an area where an identification code for uniquely specifying the medium or the like is stored. It also includes an area for storing the synchronization code. As shown in FIG. 2A, a plurality of two-dimensional codes are arranged on the medium surface in a lattice pattern. That is, a plurality of two-dimensional codes as shown in FIG. 2B are arranged on the medium surface, each of which includes a position code, an identification code, and a synchronization code. In the plurality of position code areas, different position information is stored depending on the place where each area is arranged. On the other hand, the same identification information is stored in the areas of the plurality of identification codes regardless of the place where they are arranged.

  In FIG. 2B, the position code is arranged in a rectangular area of 5 bits × 5 bits. Each bit value is formed by a plurality of minute line bitmaps having different rotation angles, and the bit value 0 and the bit value 1 are expressed by the pattern image (pattern 0 and pattern 1) shown in FIG. . More specifically, bit 0 and bit 1 are expressed using backslash “\” and slash “/” having different inclinations. The pattern image is composed of 600 dpi and a size of 8 × 8 pixels. A diagonally upward pattern image (pattern 0) has a bit value 0, and a diagonally upward pattern image (pattern 1) has a bit value 1. Express. Therefore, 1-bit information (0 or 1) can be expressed by one pattern image. By using such a minute line bitmap composed of two kinds of inclinations, a two-dimensional code capable of embedding a large amount of information with high density by providing very little noise to a visible image. It becomes possible.

That is, position information of a total of 25 bits is stored in the position code area shown in FIG. Of these 25 bits, 12 bits can be used for encoding the X coordinate, and 12 bits can be used for encoding the Y coordinate. The remaining 1 bit may be used for either encoding. If all the 12 bits are used for position encoding, 2 ¹² (4096) positions can be encoded. When each pattern image is composed of 8 pixels × 8 pixels (600 dpi) as shown in FIG. 2C, one dot of 600 dpi is 0.0423 mm. The size of the two-dimensional code (including the synchronization code) is about 3 mm (8 pixels × 9 bits × 0.0423 mm) both vertically and horizontally. When 4096 positions are encoded at intervals of 3 mm, a length of about 12 m can be encoded. In this way, all 12 bits may be used for position coding, or in the case where a pattern image detection error occurs, redundant bits for error detection and error correction may be included. .
The identification code is arranged in a rectangular area of 3 bits × 8 bits, and can store a total of 24 bits of identification information. When using the 24-bit as the identification information can be represented the identity of two ways ²⁴ (about 17 million combinations). Similarly to the position code, the identification code can include redundant bits for error detection and error correction in 24 bits.
On the other hand, the additional code is arranged in a rectangular area of 5 bits × 3 bits and can store identification information of 15 bits in total. When 15 bits are used as additional information, 2 ¹⁵ (about 33,000) additional information can be expressed. Similarly to the identification code and the position code, the additional code can include redundant bits for error detection and error correction in 15 bits.

In the example shown in FIG. 2C, the two pattern images have an angle of 90 degrees different from each other, but four types of pattern images can be configured if the angle difference is 45 degrees. When configured in this way, 2-bit information (0 to 3) can be expressed by one pattern image. That is, the number of bits that can be expressed can be increased by increasing the angle types of the pattern image.
In the example shown in FIG. 2C, the encoding of the bit value is described using the pattern image, but other than the pattern image may be adopted. For example, it is possible to perform encoding according to the ON / OFF state of the dot or the direction in which the dot position is shifted from the reference position.

By the way, in the present embodiment, only a specific type of code information can be selectively deleted (invalidated) on a medium on which a plurality of types of code information is printed.
In this specification, the term “erasure” is used for convenience, but this does not mean that the code image printed on the medium is physically erased, and information cannot be read from the code image. It means to do. In addition to making it impossible to completely read information from a code image, making it difficult to read information from a code image can be included in the concept of “erasing”. Therefore, “erasing” can be regarded as “restricting reading of information from the code image”.

The state of code erasing in the present embodiment is shown in FIGS. Here, it is assumed that the identification code, the position code, and the additional code are arranged as shown in FIG.
FIG. 3 shows an example in which code information is erased in one stage.
Among these, FIG. 3A shows a printed matter 500 in which a code image including an identification code, a position code, and an additional code is printed superimposed on a document image. On the other hand, FIG. 3B shows a printed matter 520 in which the identification code and the additional code are erased by light of a specific wavelength, and only the position code can be read.

FIG. 4 shows a first example in which code information is erased in two stages.
4A shows a printed matter 500 in which a code image including an identification code, a position code, and an additional code is printed superimposed on a document image. FIG. 4B shows a printed matter 520 in which the identification code and the additional code are erased by the first code information erasing means (light having the wavelength λ1), and only the position code can be read. Further, FIG. 4C shows a printed matter 530 in which the position code is also erased by the second code information erasing means (light having the wavelength λ2), and the code information cannot be read at all.

FIG. 5 shows a second example in which code information is erased in two stages.
Among these, FIG. 5A shows a printed matter 500 in which a code image including an identification code, a position code, and an additional code is printed superimposed on a document image. FIG. 5B shows a printed matter 510 in which the additional code is erased by the first code information erasing means (light having the wavelength λ1) and only the identification code and the position code can be read. Further, FIG. 5C shows a printed matter 520 in which the identification code is also erased by the second code information erasing means (light having the wavelength λ2) and only the position code can be read.

In order to erase the code information with light in this way, it is necessary to print the code image with an image forming material whose optical characteristics such as an absorption curve change with light. In particular, when the code information is erased separately for the light of wavelength λ1 and the light of wavelength λ2, it is necessary to print the code image with at least two image forming materials having different wavelengths of light that change optical characteristics.
In the following, taking the case of FIG. 5 as an example, invisible toner for erasing information with light of wavelength λ1, invisible toner for erasing information with light of wavelength λ2, and information erasing with light of wavelength λ1 or light of wavelength λ2. An image forming apparatus 400 that prints a code image using invisible toner that is not visible will be described.

FIG. 6 is a diagram illustrating a configuration example of the image forming apparatus 400. An image forming apparatus 400 shown in FIG. 6 is a so-called tandem type apparatus, for example, a plurality of image forming units 41 (41I ₁ , 41I ₂ , 41I ₃₎ on which toner images of respective color components are formed by electrophotography. 41K), an intermediate transfer belt 46 for sequentially transferring (primary transfer) and holding each color component toner image formed in each image forming unit 41, and a superimposed image transferred on the intermediate transfer belt 46 as a sheet (medium). A secondary transfer device 410 that performs batch transfer (secondary transfer) to P and a fixing device 440 that fixes the secondary transferred image on the paper P are provided.

In this image forming apparatus 400, in addition to the image forming unit 41K that forms a black (K) toner image, the image forming units 41I ₁ , 41I ₂ , and 41I ₃ that form invisible toner images form an image forming unit that forms a tandem. It is provided as a unit.
In the image forming units 41I ₁ , 41I ₂ , and 41I ₃ , a color material that absorbs more infrared light than the image forming unit 41K is used. Examples of such a color material include a color material containing vanadyl naphthalocyanine. Note that the K toner used in the image forming unit 41K absorbs less infrared light than the color material used in the image forming units 41I ₁ , 41I ₂ , and 41I ₃ in order to make the detection of the code image easier. Although it is desirable to use a color material, it is also possible to use a color material that absorbs commonly used infrared light, such as a color material containing carbon.

Incidentally, in this embodiment, as an invisible toner used in the image forming unit 41I _1, the absorption curve changes decomposed by light having a wavelength .lambda.1, used as absorption amount of near-infrared light becomes extremely small. Further, as an invisible toner used in the image forming unit 41I _2, the absorption curve changes decomposed by light having a wavelength .lambda.2, used as absorption amount of near-infrared light becomes extremely small. On the other hand, the invisible toner used in the image forming unit 41I _3, without degradation in light of even the wavelength λ2 in the light of the wavelength .lambda.1, use one does not change the absorption of near infrared light. The color material having these properties will be described in detail later.

In the present embodiment, each image forming unit 41 (41I ₁ , 41I ₂ , 41I ₃ , 41K) is a charger that charges the photosensitive drum 42 around the photosensitive drum 42 rotating in the direction of arrow A. 43, a laser exposure device 44 for writing an electrostatic latent image on the photosensitive drum 42 (the exposure beam is indicated by a symbol Bm in the figure), each color component toner is accommodated, and the electrostatic latent image on the photosensitive drum 42 is transferred with toner. A developing unit 45 that visualizes the image, a primary transfer roll 47 that transfers each color component toner image formed on the photosensitive drum 42 to the intermediate transfer belt 46, a drum cleaner 48 that removes residual toner on the photosensitive drum 42, and the like. The electrophotographic devices are sequentially arranged. These image forming units 41 are arranged in the order of invisible (I ₁ color, I ₂ color, I ₃ color) and black (K color) from the upstream side of the intermediate transfer belt 46.

  Further, the intermediate transfer belt 46 is configured to be rotatable in the direction of arrow B shown in the drawing by various rolls. As these various rolls, a drive roll 415 that is driven by a motor (not shown) to rotate the intermediate transfer belt 46, and has a function of giving a constant tension to the intermediate transfer belt 46 and preventing meandering of the intermediate transfer belt 46. A tension roll 416, an idle roll 417 that supports the intermediate transfer belt 46, and a backup roll 412 (described later) are included.

The primary transfer roll 47 is applied with a voltage having a polarity opposite to the charging polarity of the toner, whereby the toner images on the photosensitive drums 42 are sequentially electrostatically applied to the intermediate transfer belt 46. The toner images are sucked and a superimposed toner image is formed on the intermediate transfer belt 46. Further, the secondary transfer device 410 includes a secondary transfer roll 411 disposed in pressure contact with the toner image carrying surface side of the intermediate transfer belt 46, and a counter electrode of the secondary transfer roll 411 disposed on the back surface side of the intermediate transfer belt 46. The backup roll 412 is provided with a metal power supply roll 413 to which a secondary transfer bias is stably applied. A brush roll 414 for removing dirt attached to the secondary transfer roll 411 is disposed in contact with the secondary transfer roll 411.
A belt cleaner 421 for cleaning the surface of the intermediate transfer belt 46 after the secondary transfer is provided on the downstream side of the secondary transfer roll 411.

  Furthermore, in the present embodiment, as a paper transport system, a paper tray 430 that stores paper P, a pick-up roll 431 that picks up and transports the paper P accumulated in the paper tray 430 at a predetermined timing, and a pick-up roll 431. A transport roll 432 that transports the fed paper P, a transport chute 433 that feeds the paper P transported by the transport roll 432 to a secondary transfer position by the secondary transfer device 410, and a post-secondary transfer paper P that is a fixing device 440. A transport belt 434 that transports to the right is provided.

Next, an image forming process of the image forming apparatus 400 will be described. When a user turns on a start switch (not shown), a predetermined image forming process is executed. More specifically, for example, when the image forming apparatus 400 is configured as a color printer, digital image signals transmitted from the network 900 are temporarily stored in a memory, and the four colors (I ₁ ) stored therein are stored. , I ₂ , I ₃ , K) to form toner images of the respective colors.

That is, the image forming units 41 (41I ₁ , 41I ₂ , 41I ₃ , 41K) are driven based on the image recording signals of the respective colors obtained by the image processing. In each of the image forming units 41I ₁ , 41I ₂ , 41I ₃ , 41K, an electrostatic latent image corresponding to the image recording signal is applied to the photoconductor drum 42 uniformly charged by the charger 43. 44, respectively. Further, each written electrostatic latent image is developed by a developing unit 45 that contains toner of each color to form a toner image of each color.

  The toner image formed on each photoconductive drum 42 is transferred from the photoconductive drum 42 by the primary transfer bias applied by the primary transfer roll 47 at the primary transfer position where each photoconductive drum 42 and the intermediate transfer belt 46 are in contact with each other. Primary transfer is performed on the surface of the intermediate transfer belt 46. The toner image primarily transferred to the intermediate transfer belt 46 in this manner is superimposed on the intermediate transfer belt 46 and conveyed to the secondary transfer position as the intermediate transfer belt 46 rotates.

On the other hand, the paper P is conveyed to the secondary transfer position of the secondary transfer device 410 at a predetermined timing, and the secondary transfer roll 411 nips the paper P against the intermediate transfer belt 46 (backup roll 412). The superimposed toner image carried on the intermediate transfer belt 46 is secondarily transferred to the paper P by the action of a secondary transfer electric field formed between the secondary transfer roll 411 and the backup roll 412.
Thereafter, the sheet P on which the toner image is transferred is conveyed to the fixing device 440 by the conveying belt 434, and the toner image is fixed. On the other hand, residual toner is removed from the intermediate transfer belt 46 after the secondary transfer by the belt cleaner 421.

6 includes one image forming unit 41K that forms a black (K) toner image and three image forming units 41I ₁ , 41I ₂ , which form invisible toner images. 41I ₃ and is provided, but is not limited to such a configuration.
For example, instead of the image forming unit 41K, an image forming unit that forms any one of yellow (Y), magenta (M), and cyan (C) toner images may be provided.
The number of image forming units for forming an invisible toner image is not necessarily three, and two image forming units are sufficient to achieve the object of the present invention. Specifically, if there is no image forming unit 41I _2, it becomes a configuration for performing code erasing shown in FIG. 4, if there is no image forming unit 41I _3, the configuration for code erasing shown in FIG. 5 Become.

Next, the invisible toner used in the present embodiment will be described.
As the invisible toner in the present embodiment, the following two materials can be used.
One is a material that has an absorption wavelength in an invisible region and whose absorption curve changes with light. The other is a material having an absorption wavelength in the invisible region and whose absorption curve is not changed by light. Here, the near-infrared region is exemplified as the invisible region, and the amount of absorption of near-infrared light is extremely reduced by applying light in the former, and the latter does not change even when exposed to light. Hereinafter, the former material is referred to as “erasable recording material”, and the latter material is referred to as “non-erasable recording material”.

First, the erasable recording material will be described.
Examples of the erasable recording material include the following.
(1) Erasable recording material in which absorption curve changes (disappears) when decomposed by visible light over time. As such an erasable recording material, there is a mixture of a cyanine dye and an organic boron compound.
FIG. 7 is a diagram showing a decolorization reaction formula in this case. The first term on the left side represents a cyanine dye, and the second term on the left side represents an organoboron compound.
Here, the cyanine dye refers to a so-called cyanine dye in a broad sense in which a heterocyclic ring containing a nitrogen atom, an oxygen atom, a sulfur atom or the like is bonded with polymethine (—CH═) n. Specifically, quinoline series (so-called cyanine series), indole series (so-called indocyanine series), benzothiazole series (so-called thiocyanine series), oxazole series (so-called oxacyanine series), aminobenzene series ( So-called polymethine). Each of these has a methine chain in the dye, and the methine chain is easily decomposed by light, so that it decomposes and disappears with visible light over time.
As described above, cyanine dyes that decompose with visible light over time include the following.

Among cyanine dyes, those containing boron anions are decomposed not only by visible light over time but also by near-infrared light. When irradiated with near-infrared light, a compound containing a boron anion acts as a decomposition initiator and decomposes and decolorizes. That is, both near infrared absorption and visible absorption are zero.
As described above, cyanine dyes that can be decomposed not only by visible light but also near infrared light include the following.

  In the formula, each R independently represents an n-butyl group, n-hexyl group, or n-octyl group, and each Ar independently represents a phenyl group or anisyl group.

  In the formula, each R independently represents an n-butyl group, n-hexyl group, or n-octyl group, and each Ar independently represents a phenyl group or anisyl group.

  In the formula, each R independently represents an n-butyl group, n-hexyl group, or n-octyl group, and each Ar independently represents a phenyl group or anisyl group.

  In the formula, each R independently represents an n-butyl group, n-hexyl group, or n-octyl group, and each Ar independently represents a phenyl group or anisyl group.

  On the other hand, as the organic boron compound, one having an ammonium salt structure of a quaternary boron anion can be used. For example, the following can be mentioned.

(2) Erasable recording material in which absorption curve changes (discolors) when decomposed by near-infrared light. Such erasable recording materials include cyanine dyes containing boron anions, organoboron compounds, and aminium. There is a mixture with salt (Immonium salt). This is because the aminium salt (immonium salt) works as a photodegradation inhibitor (antioxidant), so that the cyanine dye is not decomposed (not easily) by visible light. Further, a mixture of an aminium salt (imonium salt) and an organic boron compound may be used. Aminium salt (imonium) is a cationic compound that absorbs near-infrared light. If an organic boron compound is used in combination with this, it decomposes and discolors with near-infrared light, and discolors in the same way as in (1). Become toner.
Here, as the aminium salt, those having at least one N, N-diaryliminium salt skeleton are preferable, and those represented by the following general formula are particularly preferable.

In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ each independently represents a hydrogen atom, an alkyl group, or a phenyl group, a quinone ring and a benzene ring May have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an acyl group, a nitro group, and a halogen atom.
X ⁻ represents a counter anion. Examples of the counter anion X ⁻ include inorganic acid anions such as inorganic boric acid such as Cl ⁻ , Br ⁻ , I ⁻ , ClO 4 ⁻ , PF 6 ⁻ , and BF 4 ⁻ , benzenesulfonic acid, p-toluenesulfonic acid, and naphthalene. Examples include sulfonic acid, acetic acid, and organic acid anions such as organic boric acid having an organic group such as methyl, ethyl, propyl, butyl, phenyl, methoxyphenyl, naphthyl, difluorophenyl, pentafluorophenyl, thienyl, and pyrrolyl. .

  Further, as the imonium salt, those having at least one N, N-diaryliminium salt skeleton are preferable, and those represented by the following general formula are particularly preferable.

In the formula, R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ each independently represent a hydrogen atom, an alkyl group, or a phenyl group, a quinone ring and a benzene ring May have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, an acyl group, a nitro group, and a halogen atom.
X ⁻ represents a counter anion. Examples of the counter anion X ⁻ include inorganic acid anions such as inorganic boric acid such as Cl ⁻ , Br ⁻ , I ⁻ , ClO 4 ⁻ , PF 6 ⁻ , and BF 4 ⁻ , benzenesulfonic acid, p-toluenesulfonic acid, and naphthalene. Examples include sulfonic acid, acetic acid, and organic acid anions such as organic boric acid having an organic group such as methyl, ethyl, propyl, butyl, phenyl, methoxyphenyl, naphthyl, difluorophenyl, pentafluorophenyl, thienyl, and pyrrolyl. .

Next, the non-erasable recording material will be described.
Examples of the non-erasable recording material include, for example, transition metal ions that absorb at least wavelengths in the near-infrared region, and inorganic components such as phosphoric acid, silica, boric acid, and the like that transmit visible wavelengths. In addition, glass to which a material such as a pigment made of an organic compound is added, crystallized glass obtained by crystallizing the material by heat treatment, or the like can be used.
In addition, in order to make preparation of glass and heat processing easy, you may add well-known glass network modification components, such as another alumina, an alkali oxide, and an alkaline-earth oxide. In addition, such glass may be prepared by melting once and cooling it, but when adding a material such as a pigment made of an organic compound that absorbs near-infrared wavelengths to the glass raw material. Alternatively, it may be produced by a sol-gel method or the like that can produce glass without using a melting process that requires high-temperature heating.

The invisible toner includes a binder resin as in the case of normal toner.
The binder resin is not particularly limited as long as it is an inorganic material particle satisfying the absorptivity in the visible light region and the average dispersion diameter as described above when manufactured as an electrophotographic toner. The following materials can be used.
For example, styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl acetate, methyl acrylate, ethyl acrylate, acrylic Α-methylene aliphatic monocarboxylic acid ester such as butyl acid, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl methyl ether, vinyl ethyl ether, Homopolymers or copolymers of vinyl ethers such as vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone.
Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. A polymer, polyethylene, and polypropylene can be mentioned. Further examples include polyester, polyurethane, epoxy resin, silicon resin, polyamide, modified rosin, paraffin, and waxes.

The materials that can be used for the invisible toner have been described in detail above.
By the way, in the image forming apparatus 400 shown in FIG. 6, the invisible toner used in the image forming unit 41I ₁ is decomposed by the light having the wavelength λ1, and the invisible toner used in the image forming unit 41I ₂ is the wavelength λ2. It was decomposed by the light. Therefore, among the above materials, an erasable recording material (1) that is decomposed only by visible light (the cyanine dye does not contain boron anion) is used in the image forming unit 41I _{1 and} only near-infrared light is used. decomposed, it can be used erasable recording material (2) by the image forming unit 41I _2.
Further, the invisible toner used in the image forming unit 41I ₃ was not decomposed by the light having the wavelength λ1 or the light having the wavelength λ2. Therefore, among the above materials, may be used erasable recording material by the image forming unit 41I _3.

  As described above, in the present embodiment, the reading of information is not restricted even when the toner and / or the light, which is restricted by reading light of different wavelengths, is restricted. A code image was formed using toner. As a result, a part of the code information can be selectively discarded, and a part of the code information can be used as it is.

For example, a medium in which identification information is deleted and only position information is left cannot be used to trace the original electronic document, but can be used to digitize handwritten characters. On the other hand, although it is not possible to add and digitize a medium in which position information is erased and leave only identification information, the original electronic document can be traced from there.
In addition, the designation of information to be erased may be performed by a smaller group rather than a large group such as identification information or position information. For example, if the identification information consists of a global ID (printed printer ID) and a local ID (print number in the printer), it is not possible to know which printer output by deleting only the global ID, but handwriting It is possible to obtain a memo pad consisting of a plurality of pages that can be digitized.
Alternatively, the part to be erased can be designated as a part of the code image regardless of the correspondence with the code information.

  In the present embodiment, the invisible toner whose reading of information is restricted by applying light of different wavelengths and / or a plurality of invisible that does not restrict reading of information even when light is applied. Image formation was performed using toner. Therefore, this can be extended to a configuration in which image formation is performed using a plurality of invisible toners having different optical characteristics. As an example, there is a configuration in which image formation is performed using a plurality of invisible toners for reading information with light of different wavelengths. For example, invisible toner used for reading information with infrared light is used in the first image forming unit, and invisible toner used for reading information with ultraviolet light is used in the second image forming unit. It is a configuration.

1 is a diagram showing an overall configuration of a system to which an embodiment of the present invention is applied. It is a figure for demonstrating the code image printed on a medium in embodiment of this invention. It is the figure which showed the effect | action by embodiment of this invention. It is the figure which showed the effect | action by embodiment of this invention. It is the figure which showed the effect | action by embodiment of this invention. 1 is a diagram illustrating a configuration example of an image forming apparatus according to an embodiment of the present invention. It is the figure which showed the formula of the decoloring reaction utilized in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,700 ... Terminal device, 200 ... Document repository, 400 ... Image forming apparatus, 500 ... Printed matter, 600 ... Pen device

Claims (10)

A code printing device for printing a code image in which predetermined information is readable,
First code image printing means for printing the first portion of the code image by using a first recording material whose absorption curve changes due to light of a specific wavelength and restricts reading of information;
Second code image printing means for printing the second portion of the code image using a second recording material having a characteristic relating to a change in an absorption curve by light different from the first recording material. A code printing device.   The code printing apparatus according to claim 1, wherein the second recording material does not change an absorption curve by light and does not restrict reading of information.   The code printing apparatus according to claim 1, wherein the second recording material restricts reading of information by changing an absorption curve by light having a wavelength different from the specific wavelength.   The code printing apparatus according to claim 1, wherein the first recording material and the second recording material are invisible. The first part is a part in which the first type of information is imaged,
2. The code printing apparatus according to claim 1, wherein the second portion is a portion in which the second type of information is imaged. A code printing device for printing a code image in which predetermined information is readable,
First code image printing means for printing the first portion of the code image using a first recording material for reading information with light of a first wavelength;
Code printing comprising: a second code image printing means for printing the second portion of the code image using a second recording material for reading information with light of a second wavelength apparatus. A code printing method for printing a code image including medium identification information and position information in the medium in an optically readable manner,
Printing a portion of the code image corresponding to the identification information using a first invisible toner;
A code printing method comprising: printing a portion of the code image corresponding to the position information using a second invisible toner having optical characteristics different from that of the first invisible toner. One of the first invisible toner and the second invisible toner has an absorption curve changed by light of a predetermined wavelength,
8. The code printing method according to claim 7, wherein an absorption curve of the other of the first invisible toner and the second invisible toner does not change due to light. One of the first invisible toner and the second invisible toner has an absorption curve changed by light of the first wavelength,
8. The cord according to claim 7, wherein an absorption curve of the other of the first invisible toner and the second invisible toner changes due to light having a second wavelength different from the first wavelength. Printing method. A print medium on which a code image obtained by imaging predetermined information is printed,
The code image is
A first portion printed using a first recording material that changes its absorption curve due to light of a specific wavelength and restricts reading of information;
A print medium comprising: a second portion printed using a second recording material having a characteristic relating to a change in an absorption curve due to light, which is different from the first recording material.

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