JP3036773B2 - card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Field of the Invention]

The present invention relates to a card intended for optical machine reading.

[0002]

[Prior art]

Conventionally, when a diffraction grating is used as an information pattern, information is displayed by changing the spatial frequency of the diffraction grating and / or changing the direction of the diffraction grating as shown in FIG. As a method for reading the information of the diffraction grating pattern, there is a method using the diffraction angle of the diffraction grating, a method for detecting the direction of the diffracted light as shown in FIG. 8, and the like. On the other hand, as a method of manufacturing a diffraction grating, there is a method of exposing a photosensitive film to minute interference fringes due to interference of two light beams using a laser beam of two light beams.

When a conventional diffraction grating pattern 11 as shown in FIG. 7 is used as an information pattern, if the number of patterns is to be increased, the number of output detectors (for example, one using a photodiode) is also required. Inevitably increase,
As the number of output detection units increases, a reading error easily occurs. In order to solve this, it is conceivable to use a pattern using a plurality of diffraction gratings for one pattern.

[0004]

[Problems to be solved by the invention]

However, in the case of the conventional diffraction grating pattern 11 as shown in FIG. 9, which is produced by performing multiple exposure on a plurality of diffraction gratings whose spatial frequencies and directions are desirably changed by two-beam interference using a two-beam laser beam, Not only the diffracted light of the diffraction grating, but also the diffracted light due to the interaction between them. For this reason, it has been impossible to use a pattern using a plurality of diffraction gratings for one pattern for optical mechanical reading.

An object of the present invention is to provide a card having a diffraction grating pattern using a plurality of diffraction gratings in one pattern, which is impossible as described above and can be easily read by optical and mechanical means. And

[Means for Solving the Problems]

[0006] The card according to the first aspect of the present invention is a diffraction grating in which a large number of two or more types of minute areas formed by a diffraction grating whose direction and / or spatial frequency are set according to information to be recorded are arranged adjacent to each other. A card characterized in that a lattice pattern is provided on the card.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The optical reading method described below describes a case where only the first-order diffracted light is detected, but the same applies to the detection of second-order or higher-order diffracted light. In the first embodiment, only the change in the direction of the diffraction grating is described, and in the second embodiment, only the change in the spatial frequency is described. However, the same applies to a combination of both. Further, in the present embodiment, only two types of diffraction gratings constituting a minute area of the diffraction grating pattern are described, but the same applies to three or more types of diffraction gratings.

[0008]

【Example】

Hereinafter, embodiments of the present invention will be described with reference to specific examples and comparative examples for clarifying the features of the present invention.

Example 1 Optical mechanical reading was performed by a method as shown in FIG. When the incident light 9 is irradiated by the laser oscillator 8 from right above the diffraction grating pattern 11 existing on the card 12,
The diffracted light 1 is diffracted and returned in a direction perpendicular to the direction of the line of the diffraction grating. The diffracted light 1 is detected by the photodiode 10. In the case of the reading method, information is displayed by changing the direction of the diffraction grating pattern 11. Photodiode 10
8 output detectors are arranged in a circle at equal intervals using
The diffraction light 1 in four directions as shown in FIG. 10 can be detected.

The present invention according to this reading method is, for example, a card having a diffraction grating pattern 11 as shown in FIG. The shape of the diffraction grating pattern used was a square of 2 mm × 2 mm, and the minute area composed of the diffraction grating of the diffraction grating pattern was a square of 0.05 mm × 0.05 mm. The diffraction grating pattern 11 that forms the area has a spatial frequency of
700 line / mm, the diffraction grating directions are X and Y directions
Two types having a 90-degree angle were used.

[0011] Such a card is manufactured by the following method. First, a dry plate having the diffraction grating pattern 11 is manufactured, and a transfer foil is manufactured using the dry plate as an original plate by using a well-known embossing method. FIG. 2 shows an example of the configuration of the transfer foil. Diffraction grating forming layer 5, metal evaporation layer 6, adhesive layer 7 on PET base (polyethylene terephthalate base) 3 via release layer 4
Are sequentially laminated. The transfer foil is transferred to an object to be transferred such as a PVC card by a transfer method such as thermal transfer to obtain a card.

The pattern of the diffracted light 1 when this card is used in the above-described reading method as viewed in an XY section parallel to the card is as follows:
It was as shown in FIG. Numeral 2 is a light spot, the central light spot is the diffracted light 1 from the diffraction grating pattern 11 which reflects in the incident light 9 direction, that is, the vertical direction, and the other light spots are diffracted in the direction of the diffraction grating line. Light 1. When the card was used for the above reading method, the reading was satisfactory.

(Comparative Example 1) Two kinds of diffraction gratings, that is, a spatial circumference of 700 lines / mm, and directions of the diffraction gratings make an angle of 90 degrees with each other in the X direction and the Y direction as in Example 1. FIG. 9 shows a case where the diffraction grating pattern 11 having the above diffraction grating is manufactured by a conventional manufacturing method.

When the first-order diffracted light of this card used in the optical machine reading method is viewed in a cross section parallel to the card, a pattern as shown in FIG. 11 is obtained. 2 is a light spot. The optical machine reading method is the same as in the first embodiment.
Diffraction light is generated in the diffraction pattern due to the cross-term between the respective diffraction gratings, and when used in the optical reading method, a reading error occurs.

Example 2 Optical mechanical reading was performed by a method as shown in FIG. When the incident light 9 is irradiated from directly above the diffraction grating pattern 11 existing on the card 12 by the laser oscillator 8, the diffracted light 1 is returned by diffracting at a diffraction angle corresponding to the spatial frequency of the diffraction grating pattern 11. In the case of the reading method, information is displayed by changing the spatial frequency of the diffraction grating. An output detection unit using the photodiode 10 is arranged at a predetermined position, so that the primary diffraction light can be detected. The present invention according to the above reading method is a card having a diffraction grating pattern 11 as shown in FIG. 5, for example.

In this embodiment, a 2 mm × 2 mm square was used as the pattern shape, and a 0.05 mm × 0.05 mm square was used as the minute area formed by the diffraction grating of the fixed grating pattern. As the diffraction gratings forming the area, two types of diffraction gratings were used in which the direction of the diffraction grating was the Y direction and the spatial frequency of the diffraction grating was 700 line / mm and 600 line / mm. FIG. 6 shows a pattern in which the diffracted light when this card was used in the above reading method was viewed in a cross section parallel to the card. Numeral 2 is a light spot, the central light spot is the diffracted light 1 from the diffraction grating pattern 11 which reflects in the incident light 9 direction, that is, the vertical direction, and the other light spots are diffracted in the direction of the diffraction grating line. Light 1. When the card was used for the above reading method, the reading was satisfactory.

[0017]

【The invention's effect】

As described above, according to the card of the present invention, since the card has the diffraction grating pattern composed of a plurality of minute areas formed by the diffraction grating, each card has a large number of diffraction gratings included in one pattern. Only the diffracted light is generated, no diffracted light due to the interaction is generated, and a reading error caused by the diffracted light due to the interaction does not occur, thereby facilitating optical mechanical reading. Therefore,
It is now possible to easily use a pattern using a large number of diffraction gratings for one optical pattern reading, which was impossible until now. Since this becomes possible, the number of patterns when a diffraction grating is used as an information pattern is dramatically increased, and the range of selection of information that can be displayed is widened.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a diffraction grating pattern suitable for an optical machine reading method for detecting the direction of a diffracted light in the present invention.

FIG. 2 is an explanatory sectional view of a transfer foil having a diffraction grating pattern.

FIG. 3 is a pattern diagram of diffracted light when the diffraction grating pattern of FIG. 1 is used in the reading method of FIG.

FIG. 4 is a schematic explanatory view of an optical machine reading method for detecting a diffraction angle of a diffracted light (a view of the apparatus from the side and a view of the apparatus from above).

FIG. 5 is an explanatory diagram of a diffraction grating pattern suitable for an optical machine reading method for detecting a diffraction angle of diffracted light in the present invention.

FIG. 6 is a pattern diagram of the diffracted light when the diffraction grating pattern of FIG. 5 is used in the gunning method of FIG.

FIG. 7 is an explanatory diagram of a diffraction grating pattern used as a conventional information pattern.

FIG. 8 is a schematic explanatory view of an optical machine reading method for detecting a direction of a diffracted light (a view of the apparatus from the side and a view of the apparatus from above).
It is.

FIG. 9 is an explanatory diagram of a diffraction grating pattern produced by performing multiple exposure on a plurality of diffraction gratings.

FIG. 10 is an explanatory diagram of directions of diffracted light corresponding to a diffraction grating.

11 is a pattern diagram showing a cross section of diffracted light when the diffraction grating pattern of FIG. 9 is used in the reading method of FIG. DESCRIPTION OF SYMBOLS 1 ... Diffraction light 2 ... Light spot 3 ... PET base 4 ... Peeling layer 5 ... Diffraction grating formation layer 6 ... Metal deposition layer 7 ... Adhesion layer 8 ... Laser oscillator 9 ... Incident light 10 ... … Photodiode 11 …… diffraction grating pattern 12 …… card

Continuation of the front page Judge, Takashi Murayama, Judge, Akiyoshi Sato, Judge, Takashi Yoshimura (56) , A1)

Claims (1)

(57) [Claims] 1. A card is provided with a diffraction grating pattern in which a large number of two or more types of minute areas formed by a diffraction grating whose direction and / or spatial frequency are set according to information to be recorded are arranged adjacent to each other. A card characterized by that.