JPH10251584A - Invisible fluorescent ink and coding device using the same ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject ink capable of readily visually observing printed result and making the printed result invisible or slightly visible by subjecting the printed material to decoloring treatment. SOLUTION: A material which is invisible or slightly visible when dissolved in cyanine dye, is used as a fluorescent material used for fluorescent ink. The fluorescent ink is mixed with a decolorizer such as cyanine dye which decolors when a specific wavelength is irradiated to the fluorescent ink. In this case, a cyanine dye exhibiting absorption at a wavelength longer than that excited with cyanine dye of the fluorescent material is used as the decolorizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an invisible fluorescent ink that is invisible or hardly visible, and a coding device that prints a machine-readable symbol such as a bar code on a mail using the fluorescent ink.

[0002]

2. Description of the Related Art For example, a fluorescent ink is used as an ink for providing security, and a fluorescent ink can be detected by irradiating excitation light of the fluorescent ink onto a print made with the fluorescent ink. Have been. JP-B-54-22336 and JP-A-8-23960 are used as inks for further enhancing security.
An invisible fluorescent ink which is invisible or hardly visible as described in Japanese Patent Publication No. 7 is known.

On the other hand, as a method for automatically sorting mail,
The method of automatically sorting by reading the postal code or address attached to the mail with OCR, the method of printing directly on the mail, or the method of automatically sorting by reading the bar code etc. corresponding to the address information printed using the label Are known. A coding device is known as a device for printing a barcode or the like on a mail.

A coding device is disclosed in Japanese Patent Publication No. 61-157.
As seen in Japanese Patent Publication No. 58, by inputting address information by key input, this information is converted into a barcode, and whether this barcode is printed directly on mail or a label with the barcode printed is attached. I do. For example, when the operator inputs a postal code attached to a postal matter by a key, the key input information is converted into a barcode, and the barcode is directly printed on the postal matter by a printing device. Alternatively, a label printed by a printing device is attached to mail. In this way, the barcode is read from a mail on which the barcode is printed directly or indirectly by using a reading device, and the mail is automatically sorted, for example, for each address.

In such a coding apparatus, when printing a barcode on a mail, fluorescent ink is often used because of the background of the mail or characters. That is, by irradiating the fluorescent ink with the excitation light, the barcode can be read without being greatly affected by the background or characters below the printed barcode. In particular, in the case of mail, printing a barcode on the destination address causes problems such as smearing characters, and thus the invisible fluorescent ink that is invisible or hard to see as described above is used.

When printing address information on a mail using a barcode, it is necessary to confirm whether or not the barcode has already been printed in order to avoid double printing of the barcode. That is, if the barcode is printed twice, it becomes impossible to determine when reading the barcode, and the mail is rejected. However, when a barcode is printed using invisible fluorescent ink, it cannot be checked visually.Therefore, the barcode is checked using a dedicated reader that can read the invisible fluorescent ink, or the barcode is printed using the invisible fluorescent ink. There is no choice but to irradiate the excitation light to emit visible light and visually observe it.

[0007]

As described above, conventionally, when a symbol such as a barcode is printed on mail using invisible fluorescent ink, it is difficult to visually confirm the symbol. Read and confirm, or use a specific invisible fluorescent ink that emits visible light by irradiating a specific excitation light, and irradiate this fluorescent ink with excitation light using an excitation light irradiation device For example, a large-scale device must be used to check the symbols, and the checking operation is troublesome.

According to the first and second aspects of the present invention, there is provided an invisible fluorescent ink in which a printed result can be easily visually observed, and thereafter, the printed result can be made invisible or invisible by performing a decoloring process.

The invention according to claims 3 to 6 is characterized in that the printed matter can be easily viewed, and then the printed matter can be made invisible or hard to see by performing a decoloring process. The present invention provides a coding device that can print a machine-readable symbol on a mail or the like, thereby easily checking whether the symbol is printed on a mail or the like.

Further, according to the present invention, the fluorescent ink used for printing can be erased to make it invisible or difficult to see, and the printed symbols can be read to automatically sort mail and the like, thereby improving workability. Provide a coding device that can be improved.

[0011]

According to the first aspect of the present invention,
Contains a fluorescent material that is invisible or hardly visible under visible light when dissolved in a solution, and a decolorizable material that can be decolorized by irradiating a specific wavelength. Invisible fluorescent inks with different wavelengths for coloring.

According to a second aspect of the present invention, in the invisible fluorescent ink of the first aspect, the wavelength at which the decolorable material is decolorized is longer than the wavelength at which the fluorescent material is excited.

According to a third aspect of the present invention, there is provided means for inputting or reading information such as numbers and characters, means for converting information input or read by this means into machine-readable symbols, and conversion by this means. A printing means for printing a machine-readable symbol on mail or the like using fluorescent ink is provided, and as a fluorescent ink, a decoloring material made of a dye absorbing and decoloring a specific wavelength, and being visually invisible under visible light. There is a coding apparatus that uses ink mixed with a fluorescent material made of a fluorescent dye that emits light of a different wavelength when irradiated with a specific wavelength, which is possible or difficult to see.

According to a fourth aspect of the present invention, in the coding apparatus of the third aspect, a cyanine dye is used as a decoloring dye, and a dye that emits visible light when irradiated with ultraviolet light is used as a fluorescent dye. .

According to a fifth aspect of the present invention, in the coding apparatus of the fourth aspect, the density of the cyanine dye is set to 0.1.
It is not more than 05 wt%.

According to a sixth aspect of the present invention, there is provided means for inputting or reading information such as numbers and characters, means for converting information input or read by this means into machine-readable symbols, and conversion by this means. Printing means for printing a machine-readable symbol on mail or the like using fluorescent ink; symbol reading means for reading a machine-readable symbol printed by the printing means; and a symbol reading result by the symbol reading means. Sorting means for sorting mails or the like based on the same, and decoloring means for irradiating a symbol printing portion of the mail or the like with a specific wavelength after reading the symbols by the symbol reading means. From a decoloring material consisting of a dye that absorbs and decoloring a specific wavelength and a fluorescent dye that is invisible or difficult to see under visible light and emits light of another wavelength when irradiated with a specific wavelength In the coding apparatus using ink fluorescent materials are mixed that.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view showing the entire configuration of a coding apparatus. This coding apparatus comprises an input operation unit 1, a temporary storage stacker 2, and a sorting stacker unit 3, and a mail placing unit 4 provided in the input operation unit 1. A postal matter 5 such as a postcard is placed, and a postal code and destination address information read from the postal matter 5 are input by using a keyboard 6 provided on the input operation unit 1 as well.

The address information input by key is converted into a machine-readable symbol, for example, a bar code by a microprocessor provided in the input operation unit 1. Is conveyed to a printing section to be described later, and a bar code is printed at a predetermined position of the postal matter 5 using fluorescent ink at the printing section, and the postal matter 5 having been printed is stored in the temporary storage stacker 2. It is supposed to.

The mails 5 temporarily stored in the temporary storage stacker 2 are sent out one by one to the sorting stacker section 3, and the sorting stacker 3 transports the mails 5 along the transport path 7,
A barcode is read from the mail 5 by a barcode reader 8 provided on the way. Then, the mail 5 conveyed based on the read bar code information, that is, the address information, is divided into a plurality of sorting stackers 9a, 9b, 9
c, 9d, and 9e.

FIG. 2 is a diagram schematically showing the internal structure of the coding apparatus. In the input operation unit 1, a mail 5 is made up of a belt 13 wrapped around driving rollers 11, 12 and driven rollers 14, 15. The bar code is conveyed by being sandwiched between the belts 16, and a bar code is printed by an ink jet printer unit 17 arranged in the middle of the belt 16. The postal matter 5 transported sandwiched between the belts 13 and 16 is subsequently driven by a belt 21 wrapped around driving rollers 18, 19, 20 and a driven roller opposed to the driving roller 18 via the belt 21. A driven roller 23 opposed to the driving roller 17 via a belt 21 and a guide 24 opposed to the belt 21 between the driving rollers 18 and 19.
And transported to the temporary storage stacker 2 via a transport path composed of:

The temporary storage stacker 2 stores the mail 5 between the mail holder 25 and the belt 21. The mail 5 already stored is lightly belted by the mail holder 25 by a spring (not shown). It is pushed to the 21 side,
The postal matter 5 transported between the belt 21 and the guide 24 is inserted into the frontmost side of the stored postal matter 5. The mail holder 25 stores the mail 5
When the amount of postal matter 5 to be stored increases and reaches the position of the conveyor belt 27, the conveyor belt 27 moves to the position indicated by the arrow in FIG. Since the mail 5 rotates in the direction, the mail 5 is sandwiched between the driving roller 28 and the driven roller 29 one by one and sent out to the sorting stacker section 3.

A erasing device 30 is provided as erasing means at a position facing the frontmost side of the mail 5 stored in the temporary storage stacker 2. The decoloring device 30 is disposed so as to be movable back and forth with respect to the temporary storage stacker 2, and irradiates a specific light to a decoloring material contained in the barcode ink printed by the inkjet printer unit 17. To perform the decoloring process.

The sorting stacker 3 includes a driving roller 3
A transport path is formed by the belt 34 stretched over the belts 1, 32, 33 and the belt 38 looped over the driven rollers 35, 36, 37, and the postal mail is sent between the drive roller 28 and the driven roller 29. The object 5 is transferred to the belt 34
8 to convey the sheet. The bar code reader 8 is disposed between the drive rollers 31 and 32. In addition, another driven roller 39 is opposed to the driven roller 36 via a belt 38,
The bent portion of the belt 38 is supported.

The postal matter 5 held and conveyed by the belts 34 and 38 is conveyed by driving rollers 40 and 41, and a belt 45 is driven by driven rollers 43 and 44.
The belt is transported while being held between the belts 42 and 45 of the transport path composed of the following, and subsequently, the belt 48 stretched over the driving rollers 46 and 47 and the belt 51 looped over the driven rollers 49 and 50.
The belts 48 and 51 are conveyed while being held between the belts 48 and 51, and then the belt 54 wrapped around the drive rollers 52 and 53 and the belt 57 wrapped around the driven rollers 55 and 56.
The belts 54 and 57 are conveyed by the belts 54 and 57, and the mail 5 is conveyed toward each of the sorting stackers 9a to 9e.

During the transport, when the bar code is read, for example, when the sorting stacker 9a is selected, the selector 58 rotates to store the mail 5 in the sorting stacker 9a, and when the sorting stacker 9b is selected. When the selector 59 rotates to store the mail 5 in the sorting stacker 9b, and when the sorting stacker 9c is selected, the selector 60 rotates to store the mail 5 in the sorting stacker 9c. , The mail 5 is selectively stored in each of the sorting stackers 9a to 9e.

The ink jet printer unit 17
Uses a piezo-type inkjet head 61 as shown in FIG.
Reference numeral 1 denotes an orifice plate 65 having an ink discharge port 64 fixed to a front end surface of a substrate 63 in which an ink chamber 62 is formed, a diaphragm 66 attached to a rear end surface, and an upper electrode 67 and a lower electrode 67 provided on the rear end surface of the diaphragm 66. 68
Are formed and fixed. The P
The ZT 70 and the electrodes 67 and 68 are housed in a head frame 71. An ink supply port 72 communicating with the ink chamber 62 is also formed in the substrate 63, and the ink supply port 72 communicates with an ink supply unit (not shown) provided outside.

The ink jet printer unit 17
When a pulse voltage is applied between the upper electrode 67 and the lower electrode 68, the PZT 70 deforms, the diaphragm 66 fluctuates due to the deforming operation, and a pressure change is applied to the ink in the ink chamber 62. Due to this pressure change, the ink in the ink chamber 62 is ejected from the ink ejection port 64 to print an ink dot.

The ink used for this printing is a fluorescent ink, and the fluorescent material used for the fluorescent ink is invisible or hardly visible when dissolved in a solvent, that is, an invisible material is used. The fluorescent ink is mixed with a decoloring material that decolors when irradiated with a specific wavelength. As the fluorescent material, a material which hardly absorbs under visible light and emits visible light when excited by ultraviolet light, for example, a fluorescent brightener, ER-120, ER-122
(All manufactured by Mitsui Toatsu Co., Ltd.), and a general daylight fluorescent dye having a concentration that does not cause coloration, and a fluorescent material that emits infrared light when excited by infrared light, such as neodymium ion A resin solid solution prepared by mixing a fluorescent material activated with ytterbium ions, a low-concentration cyanine dye, or a low-concentration cyanine dye at the time of emulsion polymerization of a copolymer of styrene acrylonitrile can be used. Also,
As the decoloring material, a decoloring dye such as a cyanine dye is used.

When a cyanine dye is used as the fluorescent material, the decoloring material uses a cyanine dye exhibiting absorption at a wavelength longer than the wavelength excited by the cyanine dye of the fluorescent material. Examples of the fluorescent material and the decoloring material include cyanine dyes such as NK-3377, NK-3761, and NK-380.
3, NK-4254, NK-4341, NK-3872
(All manufactured by Japan Photographic Dye Laboratories) and the like can be used.

The ink jet printer unit 17
As shown in FIG. 4, a bar code 73 is printed on the mail 5 using the fluorescent ink, for example, on the right side of the destination. The bar code 73 to be printed here is a four-state three-bar-type code. This code uses four types of bars: a long bar 73a, a left half bar 73b, a right half bar 73c, and a short bar 73d. The numbers and the like are represented by three bars by combining these four types of bars.

As the fluorescent material, for example, ER-120 is used. As shown in FIG. 5, this fluorescent material emits light at around 615 nm when irradiated with ultraviolet light at around 365 nm. Further, as shown in FIG. 6, the absorption wavelength of this fluorescent material is not at all in the visible region.
That is, the fluorescent material is invisible in the visible region. Therefore, an ink using this fluorescent material is an ink that is impossible or difficult to see unless it is irradiated with ultraviolet light. As the decoloring material, for example, NK-3761 of a cyanine dye is used.

A fluorescent solution prepared by dissolving ER-120 in ethanol at 1 wt% is prepared. Water-soluble NK-3377, NK-3761, NK-3803, N as a cyanine dye
K-4254, NK-4341, NK-3872 and the like can be used, but here, N which can be easily decolored at a specific wavelength is used.
Use K-3761. This NK-3761 is mixed with water and a wetting agent for polyhydric alcohols. As a humectant, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol,
One type or a mixture of two or more types such as tripropylene glycol is used. Here, diethylene glycol was used.

As the surfactant, a nonionic surfactant which has little bubble action and is not affected by ionicity is preferable. For example, a surfactant obtained by adding ethylene oxide to polypropylene glycol can be used. These are mixed and the working inks A, B,
C and comparative inks A and B were prepared. The ink viscosity was 10 cp (centipoise) ± 3, and the surface tension was 35 dy.
n / cm, the contact angle is preferably about 25 to 50 °, and the prototype ink here is 12 cps, 35 dyn / cm,
The contact angle was about 40 °. In addition, the heater was controlled using a heater so that the inkjet head could always be controlled at 35 ° C. Therefore, each prototype ink was 35 ° C.
To make the ink viscosity, surface tension, and contact angle satisfactory.

Working ink A Water: 30.35 wt% Diethylene glycol: 57.00 wt% Ethanol fluorescent solution: 8.00 wt% (ER-120: 0.08 wt%) Cyanine dye: 0.05 wt% Water-soluble resin: 3.00 wt % Surfactant: 1.00 wt% Antifoaming agent: 0.10 wt% Others: 0.50 wt% Working ink B Water: 30.375 wt% Diethylene glycol: 57.00 wt% Ethanol fluorescent solution: 8.00 wt% (ER-120) : 0.08 wt%) Cyanine dye: 0.025 wt% Water-soluble resin: 3.00 wt% Surfactant: 1.00 wt% Defoaming agent: 0.10 wt% Other: 0.50 wt% Working ink C Water: 30. 75 wt% diethylene glycol: 56.64 wt% ethanol fluorescent solution: 8.00 wt% (ER-120 0.08 wt%) Cyanine dye: 0.01 wt% Water-soluble resin: 3.00 wt% Surfactant: 1.00 wt% Defoamer: 0.10 wt% Others: 0.50 wt% Comparative ink A Water: 30.85 wt % Diethylene glycol: 56.55 wt% Ethanol fluorescent solution: 8.00 wt% (ER-120: 0.08 wt%) Cyanine dye: 0.00 wt% Water-soluble resin: 3.00 wt% Surfactant: 1.00 wt% Defoaming Agent: 0.10 wt% Other: 0.50 wt% Comparative ink B Water: 30.30 wt% Diethylene glycol: 57.00 wt% Ethanol fluorescent solution: 8.00 wt% (ER-120: 0.08 wt%) Cyanine dye: 0.0 10% by weight Water-soluble resin: 3.00% by weight Surfactant: 1.00% by weight Antifoaming agent: 0.10% by weight Others: 0.50 wt% Further, as a fluorescent material, a practical ink D and a comparative ink C were prepared using a fluorescent whitening agent instead of ER-120.

Ink D Water: 36.365 wt% Diethylene glycol: 58.00 wt% Cyanine dye: 0.025 wt% Fluorescent brightener: 1.00 wt% Other fluorescent dyes: 0.01 wt% Water-soluble resin: 3.00 wt% Surfactant: 1.00 wt% Defoamer: 0.10 wt% Others: 0.50 wt% Comparative ink C Water: 36.375 wt% Diethylene glycol: 58.00 wt% Cyanine dye: 0.025 wt% Fluorescent brightener: 1 0.000% by weight Water-soluble resin: 3.00% by weight Surfactant: 1.00% by weight Defoaming agent: 0.10% by weight Others: 0.50% by weight The other fluorescent dyes used in the working ink D are:
A fluorescent dye used to distinguish it from the fluorescent whitening agent contained in paper.
They are used in combination of different types or more. As the fluorescent dye, for example, as a material exhibiting a yellowish wavelength, Brill. Flavine 10GFH300%, Yellow 7G manufactured by Hodogaya Chemical Co., Ltd.
LH, Yellow 3GLH 200%, Flavin 10G-DP, Yellow 7G-DP, Kyafect Yellow G manufactured by Nippon Kayaku Co., Ltd., and fluorescent materials of other manufacturers. In addition, as a material showing a red-based wavelength,
Catilon Brilliant Pink CD-BH, KS manufactured by Hodogaya Chemical
There is a dye such as TMagenta J-FB (hereinafter, referred to as JFB).

Of course, the present invention is not limited to these. In the above embodiment ink D, JFB was used.
JFB is used in a very dilute state because it does not result in an invisible or hardly visible ink at high concentrations. 0.
By setting the content to 01 wt% or less, the ink becomes invisible or hardly visible.

The fluorescent whitening agents used in the working ink D and the comparative ink C include, for example, Mikephor BS con
c. (Mitsui Toatsu Co., Ltd., hereinafter, referred to as BS) can be used, and this BS was used here. In addition, the water-soluble resin used in each ink should be added in order to fix the fluorescent material well and to obtain a stable emission output, but it may also cause clogging of the head. Add a minimal amount. As the water-soluble resin, for example, polyvinyl alcohol, polyvinyl pyrrolidone, acrylic resin, styrene maleic acid resin, maleated polybutadiene, maleated alkyd resin, acrylic-modified shellac resin, and the like can be used.

A bar code 73 is printed on the postal matter 5 as shown in FIG. 4 using each of the inks A to D and the comparative inks A to C as shown in FIG. The visibility and the visibility after decolorization were evaluated. In the working ink D, JFB is used as a fluorescent dye, BS is used as a fluorescent whitening agent, and the emission wavelength when these are mixed and irradiated by a UV lamp is shown in FIG. Note that the hatched portions in the drawing indicate regions that contribute to the light emission output.

The absorption wavelength of the cyanine dye NK-3761 has a peak near 780 nm as shown in FIG. 8, and when this wavelength is irradiated, the color disappears as shown in FIG.
FIG. 9 is a graph showing the relationship between cyanine dye concentration and decoloration. Graph g1 shows the change in Macbeth concentration with respect to time when 0.1% by weight of cyanine dye is mixed, and graph g2 shows 0.05% by weight of cyanine dye. The graph g3 shows the change in the Macbeth concentration with respect to the time when the cyanine dye was mixed at 0.025 wt%, and the graph g4 shows the change with the time when the cyanine dye was mixed at 0.01 wt%. This shows the Macbeth density change.

Table 1 shows the evaluation results.

[Table 1]

The evaluation of the reading performance is performed by the bar code reading device 8, which is, as shown in FIG.
A lens 82, a filter 83, and a CC are provided at the center of the reading window 81.
A D camera 84 is arranged and U
V lamps (black lamps) 85 and 86 are arranged, and a signal from the CCD camera 84 is processed by a detection circuit section 87 to detect the presence or absence of a bar code.

The bar code reader 8 has a peak wavelength of 365 n from the UV lamps 85 and 86 for the mail 5.
m ultraviolet light. Due to the irradiation of the ultraviolet light, the portion printed with the fluorescent ink on the postal matter 5 emits light at a wavelength different from that of the irradiated ultraviolet light. The emitted light passes through a lens 82 and a filter 83 and is collected on a CCD camera 84.
The filter 83 is a Y52 (manufactured by HOYA) filter that passes a wavelength of 520 nm or more as shown in FIG. To cut light from

As shown in Table 1, all the inks except for Comparative Ink C were satisfactorily read as shown in Table 1. The comparative ink C could not be read because only the fluorescent whitening agent was used as the fluorescent material. From this result, ER-120 or JFB is sufficient as the fluorescent material. This fluorescent material emits light more efficiently on the longer wavelength side than the fluorescent whitening agent, and is an invisible ink that is invisible or difficult to see.

In addition, the visibility of the ink before the decoloring needs to be visible until the postal sorting process is completed. The cyanine dye NK-3761 has a green color in the ink. The inks before erasing had good visibility except for Comparative Ink A. Comparative ink A
However, since the cyanine dye is not contained in the ink, the ink becomes only the fluorescent material, and becomes an invisible ink, and cannot be visually recognized. On the other hand, when the cyanine dye is added in an amount of 0.01 wt% or more, the printed barcode becomes easily visible.

From the above, as the fluorescent inks which can be visually recognized before erasing and which can be read, practical inks A to A
D and Comparative Ink B. However,
If the barcode remains on the postal matter 5, the recipient may feel uncomfortable. Therefore, it is necessary to erase the fluorescent ink to return it to an invisible fluorescent ink that is invisible or hard to see. On the other hand, the processing of the postal matter 5 includes a sorting section and a road assembly section. Therefore, it is desirable to decolor the fluorescent ink at the stage when all the sorting tasks are completed, that is, at the stage when the route assembling is completed or during the route assembling. Some postal items 5 for which the directions are to be assembled have bar codes already printed thereon, and the bar codes can be easily confirmed before decoloring.

Therefore, the postal matter 5 for which the barcode printing has already been completed is subjected to the decoloring process to perform the division. If the barcode is not printed, it is erased after printing and classified. This erasing process is performed by the erasing device 30 arranged at the position of the temporary storage stacker 2. As shown in FIG. 12, the color erasing device 30 has a halogen lamp 92 fixed by a fixing jig 91, and a filter 93 is disposed immediately before the halogen lamp 92. The erasing device 30 also serves as a jig for discharging the postal matter 5 from the temporary storage stacker 2.

The light emission characteristics of the halogen lamp 92 are shown in FIG.
As shown in FIG. 3, the absorption wavelength of the cyanine dye is 780.
Since it has a peak near the wavelength of nm, the cyanine dye can be efficiently decolorized. In addition, light is irradiated through the filter 93 so as not to affect the fluorescent material that emits light when irradiated with ultraviolet light. The filter 93 is a filter that passes a wavelength of 560 nm or more as shown in FIG. This filter cuts the wavelength absorbed by the fluorescent material, and absorbs 780 nm of the absorption wavelength of the cyanine dye.
Any filter that transmits near m may be used.

As described above, the halogen lamp 9 of the decolorizer 30 is used.
By irradiating the light from 2 on the bar code of the mail 5 through the filter 93, the ink is decolorized. The decoloring characteristics depend on the concentration of the cyanine dye and the exposure time of the halogen lamp 92. That is, as shown in FIG. 9, the higher the concentration of the cyanine dye, the higher the initial Macbeth density (the higher the density, the darker the color), and the longer the color erasing.
If the Macbeth density is 0.05 or less after the color is erased, it is almost indistinguishable from the background of the postal matter 5.
In the case of the comparative ink B in which the cyanine dye was mixed at 0.1 wt%, even if the decoloring process was performed as shown in the graph g1, 60%.
The color cannot be erased within seconds, and the bar code changed from green to yellow can be visually recognized even after the color is erased. That is, the comparative ink B was good in the reading result and the visibility before the erasing, but was poor in the visibility after the erasing (×).
Met.

In Table 1, the poor visibility after decolorization (x) means that the color was not sufficiently decolored by the decoloring device 30 and visual observation was possible. Say. Conversely, good visibility after erasing (o) indicates that the erasing device 30 has successfully erased the color and is invisible or hard to see, ie, has become an invisible ink. From the above results, the cyanine dye concentration was 0.1%.
It is preferably not more than 05 wt%, and more preferably not more than 0.025 wt%, which can be erased within 10 seconds.

As described above, in the coding apparatus according to this embodiment, the operator reads the address information from the mail 5, makes a key input from the keyboard 6, and inputs the address information from the keyboard 6.
, The input information is converted into a barcode, and when the postal matter 5 reaches the position of the ink jet printer unit 17, the barcode is converted into a postal code using the fluorescent inks shown in the above-described embodiment inks A to D. Print on object 5. The postal matter 5 on which the barcode is printed is further conveyed and temporarily stored in the temporary storage stacker 2, and then conveyed to the sorting stacker unit 3, where the barcode printed on the postal matter 5 is read by the barcode reading device 8. The postal matter 5 is sorted and stored in any of the sorting stackers 9a to 9e based on the read barcode information, that is, the address information. As described above, the barcode is read from the postal matter 5 on which the barcode is printed, and can be automatically sorted into the sorting stackers 9a to 9e, thereby improving workability.

In the decoloring process, the mode differs between the mail 5 on which the barcode is already printed and the mail 5 on which the barcode is not printed. If it is printed, the input of the address information and the printing process of the barcode are omitted, and after the decoloring of the fluorescent ink by the decoloring device 30, it is sorted to the sorting stackers 9a to 9e. If the printing is not performed, after the address information is input and the barcode is printed, the decoloring device 30 decolorizes the fluorescent ink, and is sorted to the sorting stackers 9a to 9e.

As described above, the barcode is printed on the mail 5 using the invisible fluorescent ink as shown in the working inks A to D, so that the mail 5 can be seen before the decoloring process is performed. Therefore, it is easy to check whether or not the barcode is printed on the mail 5, and the operator does not mistakenly print the barcode on the mail 5 twice. In addition, since the invisible fluorescent ink can be easily erased by using the eraser 30, the original invisible fluorescent ink returns to the original invisible fluorescent ink after the decoloring process is performed. When delivered, the bar code on the mail is not visible or difficult to see, so it does not cause discomfort to the recipient.

In this embodiment, the case where a cyanine dye is used as the decoloring material has been described. However, the present invention is not limited to this. For example, a decoloring material that can be decolored by heat is used. It is also possible. Further, in this embodiment, the barcode cannot be read when the fluorescent material is an ink made of a fluorescent whitening agent, but this is a case where the surface of the mail contains the fluorescent whitening agent, In the case of mail that does not contain a fluorescent whitening agent, reading becomes possible, so that this type of ink can also be used.

In this embodiment, a fluorescent material excited by UV (ultraviolet) light is used as the fluorescent material. However, the present invention is not limited to this. Fluorescent materials that are excited at long wavelengths may be used. At this time, the filter of the decolorizer may be a filter that does not excite the fluorescent material.
Further, the same cyanine dye can be used as the fluorescent material and the decoloring material.

In this embodiment, the coding apparatus for printing on mail is described. However, the present invention is not limited to this, and a coding apparatus for printing other than mail may be used. In this embodiment, a barcode is described as a machine-readable symbol to be printed. However, it is a matter of course that the present invention is not limited to this. Furthermore, in this embodiment, the address information is input using the keyboard. However, the present invention is not limited to this. The postal code and the destination are optically read from the mail and automatically input. There may be.

[0056]

As described above, according to the first and second aspects of the present invention, an invisible fluorescent ink in which the printed result can be easily visually observed, and thereafter the printed result can be made invisible or difficult to see by performing a decoloring process. Can be provided.

Further, according to the inventions described in claims 3 to 6, the invisible fluorescent ink which makes it easy to visually observe the printed result and thereafter makes the printed result invisible or difficult to see by performing a decoloring process is used. Thus, it is possible to provide a coding device capable of printing a machine-readable symbol on a mail or the like, thereby easily confirming whether or not the symbol is printed on a mail or the like.

According to the sixth aspect of the present invention, the fluorescent ink used for printing can be erased to make it invisible or invisible, and the printed symbols can be read to automatically sort mail and the like. It is possible to provide a coding device that can improve the performance.

[Brief description of the drawings]

FIG. 1 is an external view of an entire coding apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing an internal configuration of a coding device according to the embodiment.

FIG. 3 is a partial cross-sectional view illustrating a configuration of an inkjet head used in the embodiment.

FIG. 4 is an exemplary view showing a postal matter on which a barcode is printed according to the embodiment;

FIG. 5 is a diagram showing light emission characteristics of a fluorescent material used in the embodiment.

FIG. 6 is a diagram showing excitation characteristics of a fluorescent material used in the embodiment.

FIG. 7 is a view showing emission characteristics of a fluorescent dye used in Ink D in the embodiment.

FIG. 8 is a diagram showing absorption characteristics of a cyanine dye used in the embodiment.

FIG. 9 is a graph showing the relationship between cyanine dye concentration and decoloration used in the embodiment.

FIG. 10 is a schematic configuration diagram of a barcode reading device used in the embodiment.

FIG. 11 is a view showing characteristics of a filter used in the bar code reader of FIG. 10;

FIG. 12 is a sectional view showing a configuration of the decolorizer used in the embodiment.

FIG. 13 is a view showing the light emission characteristics of a halogen lamp used in the decolorizer of FIG.

FIG. 14 is a diagram showing characteristics of a filter used in the decolorizer of FIG. 12;

[Explanation of symbols]

 5 Mail 6 Keyboard 8 Barcode reader 9a-9e Sorting stacker 17 Inkjet printer unit 30 Decolorer

Claims (6)

[Claims] 1. A wavelength which contains a fluorescent material which is invisible or hardly visible under visible light when dissolved in a solution and a decolorizable material which can be decolorized by irradiating a specific wavelength, and which excites the fluorescent material. And an invisible fluorescent ink, wherein the wavelength at which the decoloring material is decolorized is changed. 2. The invisible fluorescent ink according to claim 1, wherein a wavelength at which the decolorable material is decolored is longer than a wavelength at which the fluorescent material is excited. 3. Means for inputting or reading information such as numbers and characters, means for converting information input or read by the means into machine-readable symbols, and means for converting the machine-readable symbols converted by the means. Printing means for printing on mail or the like using a fluorescent ink is provided, and the fluorescent ink is invisible or hardly visible under a decoloring material and visible light, which is composed of a dye that absorbs a specific wavelength and decolorizes, A coding apparatus characterized in that the coding apparatus is an ink mixed with a fluorescent material made of a fluorescent dye that emits light of a different wavelength when irradiated with a specific wavelength. 4. The coding apparatus according to claim 3, wherein a cyanine dye is used as the decoloring dye, and a dye that emits visible light when irradiated with ultraviolet light is used as the fluorescent dye. 5. The method according to claim 5, wherein the concentration of the cyanine dye is 0.05 wt%.
5. The coding apparatus according to claim 4, wherein: 6. A means for inputting or reading information such as numbers and characters, a means for converting information input or read by this means into a machine-readable symbol, and a means for converting the machine-readable symbol converted by this means. Printing means for printing on mail or the like using fluorescent ink, symbol reading means for reading a machine-readable symbol printed by the printing means, and mail or the like based on a result of reading the symbol by the symbol reading means And a color erasing means for irradiating a symbol printing portion of the mail or the like with a specific wavelength after reading the symbol by the symbol reading means, wherein the fluorescent ink is specified by the color erasing means. A decoloring material consisting of a dye that absorbs and decoloring a wavelength and a fluorescent dye consisting of a fluorescent dye that is invisible or difficult to see under visible light and emits light of another wavelength when irradiated with a specific wavelength A coding device characterized by being an ink mixed with a light material.