Registers – Coded record sensors – Particular sensor structure
Patent
1994-01-04
1995-10-31
Hajec, Donald
Registers
Coded record sensors
Particular sensor structure
235491, 235471, 235454, 250271, 250239, G06K 710
Patent
active
054632129
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a latent image forming member, such as an ID card, and more particularly to a latent image forming member having a latent image pattern, such as a bar code having fluorescent grains dispersed and held therein, and a method of manufacturing the same.
The present invention also relates to a latent image reading apparatus for reading data recorded in the form of a latent image of a fluorescent material which emits light when it is stimulated by infrared rays, from an object on which the latent image has been formed. More particularly, the present invention relates to an arrangement and characteristics of an infrared ray source for irradiating a latent image with infrared rays and of a light detection device for detecting excited light from the latent image.
The present invention further relates to an information recording medium having a latent image mark and a system for reading the same, and more particularly to a configuration of the latent image mark and of an optical system of a reading apparatus.
2. Discussion of Related Art
In recent years, control of articles by means of bar codes has been performed widely in various industrial fields while centering the PDS (Point Of Sales) in the distribution field. Along with this, a suggestion has been made that a non-visible bar code, chat is, a latent image bar code is put on in terms of improving design and security (see, for example, Japanese Patent Application Laid-Open No. 52-80906).
As for manufacturing of the latent image bar code, a method has been suggested (see, for example, Japanese Patent Application Laid-Open No. 53-9607) in which a ribbon containing fluorescent grains is made to be transferred to paper upon impact so that the latent image bar code is printed on to the paper.
At present, if the latent image bar code of the foregoing type is formed on an ID card for use as a credit card or the like, there arise a problem of unsatisfactory durability, such as the wear resistance and chemical resistance against, for example, alcohol. It will come to be difficult to read the latent image bar code as the card is repeatedly used. Therefore, the code of the foregoing type has a disadvantage that the card cannot be used for a long time.
Further, a latent image reading apparatus has been known (see for example Japanese Patent Application Laid-Open No. 52-80906 and Japanese Patent Application Laid-Open No. 53-9600) in which data recorded in the form of a latent image of a florescent substance that emits light when it is stimulated by infrared rays, is read from paper on which the latent image has been formed.
The latent image can be obtained by printing, for example, on white paper or plastic, with ink which is obtained by mixing 200 g of sodium yttrium fluoride (NaYF.sub.4) fluorescent substance activated by, for example, ytterbium and erbium with 160 g of vinyl chloride type resin and 40 g of plasticizer, followed by dispersing the mixture in a 400 g of solvent. When the latent image of the foregoing type is irradiated by infrared rays, for example, a gallium arsenide (GaAs) infrared ray emitting diode, the ink emits light, the excited light having a wavelength different from that of the infrared ray. The reading apparatus for reading the latent image receives the excited light from the ink, and treat or process a signal of the light to read out the data recorded in the latent image.
Since the excited light obtainable from the latent image is very weak, if infrared rays from the infrared ray source is not efficiently applied to the latent image or if the excited light from the latent image is not efficiently incident upon a light detection device disposed in the reading apparatus, a high level of reading signal cannot be obtained and reading error is liable to occur.
In order to overcome a problem of the foregoing type, a conventional reading apparatus has been formed, as shown in FIG. 17 and FIG. 18, in such a manner that an excellent-directivity infrared ray source and a light
REFERENCES:
patent: 3169186 (1965-02-01), Howard
patent: 3473027 (1969-10-01), Freeman et al.
patent: 3483388 (1969-12-01), Ogle et al.
patent: 3691350 (1972-09-01), Kuhns et al.
patent: 3812328 (1974-05-01), Tramposch
patent: 3919447 (1975-11-01), Kilmer, Jr. et al.
patent: 3949219 (1976-04-01), Crouse
patent: 4151667 (1979-05-01), Idelson et al.
patent: 4157784 (1979-06-01), Grottrup et al.
patent: 4202491 (1980-05-01), Suzuki
patent: 4282430 (1981-08-01), Hatten et al.
patent: 4647766 (1987-03-01), Dimur et al.
patent: 4757188 (1988-07-01), Nakarai et al.
patent: 4816659 (1989-03-01), Bianco et al.
patent: 4983817 (1991-01-01), Dolash et al.
patent: 5210411 (1993-05-01), Oshima et al.
Itoh Akihiko
Matsumoto Taiji
Nishida Masato
Ohiwa Tsunemi
Oshima Toshio
Hajec Donald
Hitachi Maxell Ltd.
Lee Michael G.
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