JPH07314916A - Medium for heat-sensitive recording and recording medium as well as method for recording and reproducing by using these mediums - Google Patents

Abstract

PURPOSE:To improve storage properties of a recorded information and to make its forgery to be hardly done. CONSTITUTION:A heat-sensitive recording medium is irradiated with a heat beam for recording from its surface protective layer 1 to form respectively a microtransmitting part 20 for incident light and a microtransmitting part 40 for emitted light and the position of a transmitting light path 30 and the angle psi of transmittance constituted of a pair of microtransmitting parts 20 and 40 and provided in each heat-sensitive recording layer a substrate are recorded as recording informations to obtain a recording medium 17. In addition, a light receiving element 11 is arranged on the heat-sensitive recording layer 4 wherein the microtransmitting part 40 for emitted light of this recording medium and it is emitted with a light beam 10 from the heat-sensitive recording layer 2 wherein the microtransmitting part 20 for incident light is formed to detect the position of the transmitting light path 30 and the angle psi of transmittance and the recorded information is reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to I, such as membership cards and employee ID cards.
A thermal recording medium applicable to various cards such as a D card, a credit card, and a prepaid card, a recording medium using the thermal recording medium, and a recording / reproducing method thereof.
In particular, the present invention relates to a thermosensitive recording medium which has high storability of recorded information and is hard to be forged, a recording medium, and a recording / reproducing method using such a medium.

[0002]

2. Description of the Related Art As a recording medium of this type, a magnetic card in which a magnetic material is arranged on a card base has been widely used. In this magnetic card, a magnetic head is brought into contact with the magnetic body to partially magnetize the magnetic body to record information, while the magnetic head is brought into contact with the magnetized magnetic body to reproduce recorded information. Met.

[0003]

By the way, this kind of magnetic card has a drawback that the recorded information is easily destroyed due to the influence of the external magnetic field in the surroundings, and the magnetic head is brought into contact with the recording / reproducing. Since this method is used, both the magnetic head and the magnetic card are prone to deterioration over time. Further, since the information recorded on the magnetic material can be easily read, there is a problem that it is easily forged.

In addition to a magnetic card, an optical card for reading information optically by changing the reflectance, an IC card having an internal electronic memory, and the like are known.
It has problems in terms of handling such as measures against static electricity and maintenance of the reading device, and has not yet been widely used.

The present invention has been made by paying attention to such a problem, and an object thereof is a thermosensitive recording medium and a recording medium which have high preservability of recorded information and are hard to be forged. It is to provide a recording / reproducing method using such a medium.

[0006]

That is, the invention according to claim 1 is a light-transmissive support and is made light-transmissive by being irradiated with a recording heat beam provided on at least both front and back surfaces of the support. It is characterized by comprising a light-impermeable heat-sensitive recording layer and a light-permeable protective layer provided on the surface of each heat-sensitive recording layer.

The heat-sensitive recording medium according to the first aspect of the present invention is used for manufacturing the recording medium described below. That is, a heat beam for recording is irradiated from at least one protective layer side of the heat-sensitive recording medium according to the first aspect of the invention so that each heat-sensitive recording layer is provided with a light transmitting minute transmitting portion and a light emitting minute transmitting portion. A recording medium is obtained by recording, as recording information, the position and the transmission angle of a transmission optical path formed by a pair of minute transmission portions provided in each thermosensitive recording layer and a support.

In the case where a light-impervious heat-sensitive recording layer is provided inside the support, a recording medium manufactured using this heat-sensitive recording medium has a light-impervious property provided inside the support. The heat-sensitive recording layer acts to make it difficult to confirm the state of the transmitted light path. The invention according to claim 2 is based on such a technical reason.

That is, the invention according to claim 2 is premised on the heat-sensitive recording medium according to the invention according to claim 1, wherein the support is two or more light-transmissive base materials and these light-transmissive substrates. It is characterized in that it is composed of a light-impermeable heat-sensitive recording layer which is interposed between materials and becomes transparent when irradiated with a recording heat beam.

The invention according to claims 3 to 4 relates to an invention in which the material of the heat-sensitive recording layer and the materials of the support and the protective layer are specified.

That is, the invention according to claim 3 is premised on the thermosensitive recording medium according to claim 1 or 2,
The heat sensitive recording layer absorbs a heat beam for recording, and the invention according to claim 4 is based on the heat sensitive recording medium according to any one of claims 1 to 3, and the support is The protective layer has heat resistance to withstand the recording temperature of the heat-sensitive recording layer.

Next, the invention according to claims 5 to 6 is defined by claim 1.
The present invention relates to a recording medium obtained by using the heat-sensitive recording medium according to any one of items 1 to 4.

That is, the invention according to claim 5 is such that a light-transmissive support is provided, and a micro-transmission part for light incidence is formed on one of the front and back surfaces of this support, and a micro-transmission part is provided on the other. A pair of light-impermeable recording layers each having a transparent portion and recording position information and a transmission angle of a transmitted light path formed by the pair of minute transparent portions and a support, and the surface of each recording layer. The invention according to claim 6 is characterized in that the support comprises two or more light-transmitting base materials,
It is characterized in that it is composed of a light-impermeable heat-sensitive recording layer which is interposed between these light-transmissive substrates and becomes light-transmissive when irradiated with a recording heat beam.

In these recording media, the light receiving element is arranged on the side of the thermosensitive recording layer on which the light transmitting minute transmitting portion is formed, and the light receiving element is arranged on the side of the heat sensitive recording layer side for reproducing. Recorded information is reproduced by irradiating a light beam to detect the position and transmission angle of the transmitted light path, but one of the support and the protective layer has a function of blocking light having a wavelength different from that of the reproduction light beam (that is, When it has the function of an optical filter), it has an advantage of making it more difficult to confirm the state of the transmission optical path provided in this recording medium. The invention according to claim 7 is based on such a technical reason.

That is, the invention according to claim 7 is based on the recording medium according to claim 5 or 6, and at least one of the support and the protective layer emits light having a wavelength different from that of the reproduction light beam. It is characterized by blocking.

Further, the invention according to claims 8 to 10 relates to the invention of the above-mentioned thermal recording medium and a recording / reproducing method using the recording medium.

That is, the invention according to claim 8 irradiates each thermal recording layer by irradiating the thermal recording beam from at least one protective layer side of the thermal recording medium according to any one of claims 1 to 4. The position and the transmission angle of the transmitted light path, which is formed by the light incident minute transmitting portion and the light emitting minute transmitting portion and which is formed by the pair of minute transmitting portions provided in each thermosensitive recording layer and the support, are used as recording information. While recording and obtaining a recording medium, a light-receiving element is arranged on the side of the heat-sensitive recording layer on which the light-transmitting micro-transmission part is formed and the recording medium is reproduced from the thermo-sensitive recording layer side on which the light-incident micro-transmission part is formed. The recording information is reproduced by irradiating a light beam to detect the position and the transmission angle of the transmission optical path, and the recording information is recorded according to the invention of claim 8.・ For recording above, assuming playback method 11. The invention according to claim 10, wherein the light source of the beam and the reproduction light beam is composed of a single wavelength light source, and the depth of focus thereof is substantially equal to or more than the thickness dimension of the thermosensitive recording medium and the recording medium. Is based on the recording / reproducing method according to the invention of claim 8 or 9,
The recording heat beam and the reproduction light beam have substantially the same beam diameter.

In such a technical means, the incident angle of the recording heat beam with respect to the heat-sensitive recording medium can be limited to several steps. In particular, [θ1, θ2, ... θ
n] is the incident angle, [r1, r2, ... rn] is the heat-sensitive diameter of the heat-sensitive recording layers 2 and 4 at that time, and the thickness of the support 3 is h, the heat-sensitive recording layer 2 on the heat beam source side for recording. The deviation [x1, x2, ... Xn] of the transmission beam irradiation center position of the other thermosensitive recording layer 4 from the upper beam irradiation center position is calculated from the incident angle θi by the law of refraction sin (θi) / sin (ψi). ) = N ₃ (where n ₃ is the refractive index of the support) and is obtained as an approximation to obtain a transmission angle [ψ
1, ψ2, ... ψn], xi = h · tan (ψi), and the heat-sensitive range of the second layer (that is, the heat-sensitive recording layer 4) is a relative position from (xi-ri / 2). (Xi + ri / 2) (see FIG. 1).

Therefore, when the step i of the incident angle of the recording heat beam with respect to the heat-sensitive recording medium is changed, it is desirable to selectively set the heat-sensitive ranges so that they do not overlap each other.

Further, the transmission angles are [ψ1, ψ2, ...
ψn], the incident angle φi of the reproducing light beam with respect to the transmission angle ψi is obtained from the law of refraction, and the incident angle is [φ1, φ2, ... φn].
Can be limited to

Next, when forming a transmitted light path on the thermosensitive recording medium, it is not necessary to have one transmitted light path, and a plurality of such transmitted light paths are formed, and information is recorded by the combination of the position and the transmission angle of each transmitted light path. It is a thing.

Further, when forming the above-mentioned transmitted light path, the recording heat beam is not limited to irradiating from a single direction and recording may be performed by arbitrarily selecting from both sides.

Further, when forming one transmitted light path, the recording heat beam may be irradiated from one side, or one recording light beam may be irradiated from both sides to form one transmitted light path. However, it is optional. However, irradiating the recording heat beams from both sides does not mean simultaneous irradiation, and may be simultaneous or separate.

Here, the term "heat-sensitive in the heat-sensitive recording layer" generally means a change in light transmittance due to heat, including thermal destruction such as melting or burning.

Further, each light source of the recording heat beam and the reproducing light beam means a light source only, and includes a collimator lens group, a focusing lens group and the like.

The transmission angle as recording information includes the direction in addition to the normal angle formed by the perpendicular of the recording medium surface and the transmitted light path. That is, two angle components in the case where the origin is placed in the minute transmission part and polar coordinates are displayed with the perpendicular as the Z axis are recorded as the transmission angle. However, for simplicity,
The transmission angle is limited to the ordinary meaning and used in the description.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is an explanatory view showing a schematic cross section of a recording medium 17 and a recording method. Although not shown in the figure, the recording heat beam 6 is emitted from the recording heat beam source of the recording apparatus directly or through various optical elements at an incident angle θ, that is, the heat-sensitive recording medium, that is, the light-transmissive support 3. Thermal recording layer 2, 4
When irradiated from one side of the heat-sensitive recording medium, the main part of which is composed of the surface protection layer 1 and the surface protection layers 5 and 5, the recording heat beam 6
Is, for example, thermally destroyed the thermosensitive recording layer 2 to form and transmit the minute transmissive portion 20, and also permeates the support 3 to thermally destroy the second thermosensitive recording layer 4 to form the minute transmissive portion 40, Further, it escapes to the outside of the thermal recording medium through the surface protective layer 5. In this way, the transmission optical path 30 having the transmission angle ψ is formed and recorded in the medium, to be precise, between the thermal recording layers 2 and 4. The incident angle θ and the transmission angle ψ do not generally match and are related by the above law of refraction. Further, as described above, a transmission optical path equivalent to this may be formed by irradiating recording heat beams from both sides of the thermal recording medium, and the thermal recording layer may have two or more layers. Good. In FIG. 1, 7 is the incident direction of the recording heat beam 6, r is the beam diameter of the recording heat beam 6, h is the thickness of the support 3, and x is the minute transmissive portion 20 formed in the thermosensitive recording layer 2. And the shift amount of the central position of the minute transmissive portion 40 formed on the thermal recording layer 4 are shown.

FIG. 2 is an explanatory view showing a schematic cross section of the recording medium 17 and a reading and identifying method. Although not shown in the figure, the reproducing light beam 10 is irradiated from the reproducing light beam source of the reproducing apparatus directly or through various optical elements at an incident angle θr from one side of the recording medium 17, and the thermal recording layer 2 is formed. When the heat-sensitive position (that is, the heat-sensitive portion 8) and the transmission angle ψ are close, transmitted light is detected by the light receiving element 11 of the reproducing device. It should be noted that the transmission angle ψ in the recording medium 17 from the incident angle θr
Can be calculated by the above-mentioned law of refraction. Further, when the reproducing light beam 10 emitted from the reproducing apparatus irradiates a position on the thermosensitive recording layer 2 which is not heat-sensitive (see FIG. 3) or when the incident angle θr is different from the transmission angle ψ (FIG. 4 and (See FIG. 5) is not transmitted or is small even if it is transmitted. Therefore, a threshold value is set for the detection amount of the light receiving element 11, and if it is less than this threshold value, it may be determined as non-transmission. The transmission angle is changed by repeating a trial of irradiating the recording position of the recording medium 17 while changing the incident angle, continuously changing the incident angle, or by irradiating the reproducing light beams having different incident angles at the same time. To decide. At this time, if the transmission angle is within a certain range, it can be detected as a recording abnormality (see FIG. 6).

For forgery checking, a method may be adopted in which a recording device sets a transmission angle which is not used for recording in advance, and the recording device determines that the recording device is abnormal even when the reproduction device detects the transmission angle.

In this recording medium, recording and reproduction are carried out by utilizing optical transparency, so that it is semi-permanent unless surface scratches, complete bending, or structural destruction such as heating or chemical change. Can be used for.

Further, even if the recording medium is forged by the contact heating means 12 such as a thermal head or a thermal needle, as shown in FIGS. 7A to 7C, one side of the thermal recording medium is When heated from above, only the heat-sensitive recording layer 2 on the heating side is heat-sensitive, or even if the other heat-sensitive recording layer 4 is also heat-sensitive, the heat-sensitive area is different and it becomes difficult to record the angle information. Further, even if it is possible to heat the heat-sensitive recording layer by contact heating from both sides of the heat-sensitive recording medium, or to heat the heat-sensitive recording layer by non-contact heating using a laser or the like, from the already-recorded recording medium. Forgery of the recording medium is difficult because it is usually impossible to measure the position of the transmitted optical path or the transmission angle, and further to measure the combination pattern thereof. Furthermore, when at least one of the support and the surface protective layer has a function of an optical filter that transmits a specific wavelength, the measurement cannot be performed unless the wavelengths of the reproducing light beams match (claim 7). Further, when the light-impermeable heat-sensitive recording layer 2'is provided inside the support composed of the two light-transmitting substrates 3'and 3 ", the dummy minute transmitting portions 21 and 41 are provided near the surface protective layer. By forming only the heat-sensitive recording layers 2 and 4, it becomes difficult to measure the transmission state of the heat-sensitive recording layer 2 ′ inside, so that the recording medium 17 can be more completely prevented from being forged (claims 2 and 6). (See Fig. 8) Further, the forgery can be made difficult by setting the beam diameter of the recording heat beam to be small so that the heat-sensitive area of the heat-sensitive recording layer is narrowed to achieve high definition.

Further, the recording heat beam 6 in the recording apparatus is used.
When the incident angle of is limited to several steps, the incident angle of the reproduction light beam 10 in the reproducing apparatus can be correspondingly limited to several steps as described above. In this case, the reproducing apparatus may have a structure in which the incident angle of the reproducing light beam 10 is controlled by an optical device, for example, a polarization mirror 18 (see FIG. 9), or a plurality of reproducing units corresponding to the number of stages of the incident angle. The light source of the light beam 10 may be installed to directly irradiate the light (see FIG. 10). If the latter structure is adopted, it is efficient because there is no energy loss due to passing through the optics.
Moreover, since the transmission angle can be digitally determined, there is an advantage that the reliability of reproduction is improved. In FIG. 9, 15 is a light source, 16 is a concave lens, and 23 is an optical sensor array,
Moreover, in FIG. 10, 23 is an optical sensor array and 24 is a light source array.

[0034]

According to the heat-sensitive recording medium according to the present invention, a light-transmissive support and a light-transmissive support provided on at least front and back surfaces of the support are irradiated with a heat beam for recording. Since it has a light-impervious heat-sensitive recording layer and a light-transmissive protective layer provided on the surface of each heat-sensitive recording layer, recording is performed from at least one protective layer side of this heat-sensitive recording medium. The thermosensitive recording layer is irradiated with a heat beam to form a light transmitting minute transmitting portion and a light emitting minute transmitting portion, respectively, and each heat sensitive recording layer comprises a pair of minute transmitting portions and a support. It is possible to obtain a recording medium in which the position and the transmission angle of the transmitted light path are used as recording information.

Further, according to the recording medium of the present invention, the light-transmissive support and the minute transmission part for light incidence are provided on both front and back surfaces of the support. On the other hand, a minute transmitting portion for emitting light is formed on the other side, and a pair of optical opaque portions having the position and the transmitting angle of the transmitted optical path constituted by the pair of minute transmitting portions and the support as recorded information are formed. Since the recording layer and the light-transmissive protective layer respectively provided on the surface of each recording layer are provided, the light-receiving element is arranged on the side of the heat-sensitive recording layer on which the light-transmitting minute transmission part is formed and It is possible to reproduce the recorded information by irradiating the reproducing light beam from the thermosensitive recording layer side on which the incident minute transmitting portion is formed and detecting the position and the transmitting angle of the transmitting optical path.

Further, according to the recording / reproducing method of the invention described in any one of claims 8 to 10, the recording heat beam is applied from at least one protective layer side of the heat-sensitive recording medium according to any one of claims 1 to 4. To form a light transmitting minute transmitting portion and a light emitting minute transmitting portion on each heat-sensitive recording layer, and a transmission composed of a pair of minute light transmitting portions and a support provided on each heat-sensitive recording layer. The position and the transmission angle of the optical path are recorded as recording information to obtain a recording medium, and a light receiving element is arranged on the side of the heat-sensitive recording layer on which the light transmitting minute transmitting portion of the recording medium is formed and the light incident minute transmitting portion is The recording light is reproduced by irradiating the reproducing light beam from the formed thermal recording layer side to detect the position and the transmission angle of the transmitted light path.

Since recording / reproducing is performed by utilizing optical transparency in the heat-sensitive recording medium and the recording medium used in this recording / reproducing method, surface scratches, complete bending and heating are performed. It is possible to continue its use semi-permanently as long as there is no structural destruction such as chemical change.

Further, since it is usually impossible to measure the position and transmission angle of the transmitted light path or the combination pattern thereof from the recorded recording medium, it is possible to make counterfeiting of the recording medium difficult.

[0039]

[Embodiment] This embodiment relates to an employee ID recording and identification system applied to a door opening / closing operation.

11A and 11B show a plan view and a sectional view of an ID-unrecorded employee ID card 26 which is a thermal recording medium. That is, this ID-unrecorded employee ID card is provided with a face photograph and proof items such as name and affiliation on the display surface, and a heat sensitive recording area 27 is provided in a part thereof.
As shown in FIG. 11B, the heat-sensitive recording area 27 includes a light-transmissive support 3 made of a polymer material having heat resistance such as PVC or PET, and tin or the like provided on both surfaces of the support 3. Thermal recording layers 2 and 4 made of a material having low heat resistance,
The main part of the thermosensitive recording layers 2 and 4 is composed of the light-transmitting surface protective layers 1 and 5, and the thermosensitive recording layers 2 and 4 are thermally destroyed by irradiation of the recording heat beam. It is a medium in which a transmission optical path is formed. Therefore, the support 3 has about 5
In contrast to the thickness of 00 μm, each of the thermosensitive recording layers 2 and 4 is very thin and the thickness thereof is about 10 nm to 1 μm.

FIG. 12 is a schematic view of a recording device for an ID-unrecorded employee ID card.

That is, this recording apparatus, as a recording heat beam light source, outputs 100 mW at a small emission point of 10 μm or less.
4 laser light sources are used. This light source array 30 has an ID
One spot on the surface of unrecorded employee ID 26, and
The ID-unrecorded employee ID card 26 is adjusted so that the irradiation angles thereof are [−60 degrees, −20 degrees, 20 degrees, 60 degrees] with respect to the normal line on the surface of the ID-unrecorded employee ID card 26.
Are arranged perpendicularly to the transport direction 29. Also,
A light source having a deep beam diameter of 100 μm and a depth of focus of 800 μm or more is applied to each light source.

The light source array 30 includes the controller unit 3
A switching controller (not shown) built in the controller unit 33 is connected to the light source 3 to select a light source according to the input ID data from the input unit 36 and perform switching. It is also possible to simultaneously turn on a plurality of light sources to record two transmitted light paths from the same irradiation point. However, in the recording apparatus according to this embodiment, only one light source is turned on from the viewpoint of importance of reading accuracy. It is configured to let. In addition, I
D The unrecorded employee ID 26 is conveyed and scanned at a constant speed of 5 cm / s.

Then, the one light source selected by the switching controller is turned on to irradiate the heat-sensitive recording area 27 of the ID-unrecorded employee ID card 26 with the recording heat beam,
A part of the heat-sensitive recording layers 2 and 4 is thermally destroyed to open a pair of minute transmissive portions to form a transmitted light path composed of the pair of minute transmissive portions and the support 3. In this case, by increasing the irradiation time for one time, a slit-shaped minute transmissive portion instead of a perfect circle (see FIG. 13, the opening shown by the solid line in the figure indicates the minute transmissive portion formed on the thermosensitive recording layer 2). The portion 20 and the opening shown by the broken line represent the minute transmission portion 40 formed in the thermosensitive recording layer 4). When such a slit-shaped micro-transmission part is opened, reading can be performed while shifting the position of one micro-transmission part. Therefore, the writing error due to the structural disorder of the thermal-destruction part during recording or the structure of the thermal-destruction part This has the effect of reducing reading errors due to disturbance. In this embodiment, the holes are adjusted to have a length five times the slit width at regular intervals.

Further, this recording apparatus is constructed so as to read the recorded information for improving the reliability as shown in FIG. That is, a light source array 31 for reproducing light beam composed of four light sources is arranged at a position distant from the light source array 30 for recording heat beam in the scanning direction, and each light source of this light source array 31 is arranged. The irradiation angles are [-60 degrees, -20 degrees, 20 degrees
, 60 degrees]. Each light source has substantially the same wavelength, beam diameter, depth of focus, etc. as the light source of the recording heat beam except that the output is small and a few mW, and this light source array 31 also has the controller section 33.
It is connected to the. In addition, the light source array 31 of the reproduction light beam
The optical sensor row 23 is arranged on the transmitted light path when the ID recorded employee ID card 26 is arranged opposite to, and
A decoder unit 35 for reading reproduction information is connected to the optical sensor array 23. Further, the decoder unit 3
5, a comparator 34 for comparing the reproduction information from 5 and the input information from the input section 36, and an error display 32 for displaying an error according to the output information from the comparator 34.

When the ID recorded employee ID card 26 is conveyed to the readable position by the roller 28, the four light sources of the reproducing light beam light source array 31 are simultaneously turned on for each slit in synchronization with the recording position. In this case, since the output of each light source is very small, the thermal recording layer of the ID-recorded employee ID card 26 will not be thermally destroyed by this irradiation.

In the decoder section 35, (1)
Four analog resistance values of each sensor in the optical sensor array 23 are time-integrated by an integrator circuit, and (2) each of the four integrated values is compared with a designated threshold value to determine transmission or non-transmission. A recording error is displayed when two or more reproducing light beams are judged to be transmitted, while in other cases (4
The code is sent to the comparator 34 in accordance with the transmitted light beam (in the case where both are opaque or only one is transmitted).

The comparator 34 sequentially compares the input ID code from the input section 36 and the code from the decoder section 35, and displays a recording error when they are different, while recording errors are displayed when the codes match. The recording operation is terminated without displaying.

Regarding the light source array 31 for the reproducing light beam, a heat beam output control mechanism is added to the light source array 30 for the recording heat beam, and a reciprocating transport mechanism for the ID unrecorded or recorded employee ID 26 is provided. Therefore, the light source array 30 of the recording heat beam can be used instead.

FIG. 14 is an explanatory view showing the schematic structure of the employee ID identification device. The structure of this identification device is
Since it is almost the same as the reading operation unit of the recording apparatus, description thereof will be omitted. However, the comparator 34 is adjusted so as to compare the read code from the decoder unit 35 with the code registered in the employee database 38 and drive the door control unit 37 depending on the presence or absence of the corresponding code. That is, in the identification device shown in FIG. 14, if the corresponding code exists, the door control unit 3
The door is designed to open and close via 7.

[0051]

According to the heat-sensitive recording medium of the present invention, a light-transmissive support is provided, and a recording heat beam is provided on at least both front and back surfaces of the support to emit light. Since it is provided with a light-impermeable heat-sensitive recording layer that becomes transparent and a light-transmitting protective layer provided on the surface of each heat-sensitive recording layer, from the side of at least one protective layer of this heat-sensitive recording medium. By irradiating a heat beam for recording, a micro-transmission part for light incidence and a micro-transmission part for light emission are respectively formed on each thermosensitive recording layer, and a pair of microtransmission parts and a support provided on each thermosensitive recording layer are formed. There is an effect that a recording medium in which the position and the transmission angle of the formed transmission optical path are used as recording information can be obtained.

According to the recording medium of the present invention, the light-transmissive support is provided, and the light-transmitting minute transmission part is formed on both front and back surfaces of the support. On the other hand, a minute transmitting portion for emitting light is formed on the other side, and a pair of optical opaque portions having the position and the transmitting angle of the transmitted optical path constituted by the pair of minute transmitting portions and the support as recorded information are formed. Since the recording layer and the light-transmissive protective layer respectively provided on the surface of each recording layer are provided, the light-receiving element is arranged on the side of the heat-sensitive recording layer on which the light-transmitting minute transmission part is formed and The recorded information can be reproduced by irradiating the reproducing light beam from the thermosensitive recording layer side on which the incident minute transmitting portion is formed and detecting the position and the transmitting angle of the transmitting optical path.

Furthermore, according to the recording / reproducing method of the present invention, the heat-sensitive recording medium and the recording medium used in this recording / reproducing method utilize optical transparency. Since recording / reproducing is performed, it is possible to continue to use it semi-permanently as long as there is no damage on the surface, complete bending, structural damage such as heating or chemical change, and from the recorded recording medium. Since it is usually impossible to measure the position and the transmission angle of the transmitted light path or the combination pattern thereof, it has the effect of making it difficult to forge the recording medium.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a schematic cross section of a recording medium according to the present invention and a recording method.

FIG. 2 is an explanatory view showing a schematic cross section of a recording medium according to the present invention and a read identification method.

FIG. 3 is an explanatory diagram of an example in which a reproduction light beam cannot pass through a transmission optical path of a recording medium.

FIG. 4 is an explanatory diagram of another example in which the reproduction light beam cannot pass through the transmission optical path of the recording medium.

FIG. 5 is an explanatory diagram of an example in which a part of the reproduction light beam cannot pass through the transmission optical path of the recording medium.

FIG. 6 is an explanatory diagram showing a reading error during reproduction.

FIG. 7 is an explanatory diagram showing a forgery process of a recording medium using a thermal head.

FIG. 8 is an explanatory diagram of a recording medium having a light-impermeable heat-sensitive recording layer inside a support.

FIG. 9 is an explanatory diagram of a method of reproducing recorded information on a recording medium.

FIG. 10 is an explanatory diagram of another method of reproducing recorded information on a recording medium.

FIG. 11A is a plan view of an ID unrecorded employee ID card according to the embodiment, and FIG. 11B is an explanatory view showing the layer structure of the heat-sensitive recording area.

FIG. 12 is an explanatory diagram showing a configuration of a recording apparatus according to an embodiment.

FIG. 13 is an enlarged plan view of a heat-sensitive recording area in which slit-shaped minute transmissive portions are formed.

FIG. 14 is an explanatory diagram showing a configuration of an employee ID identification device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface protective layer 2 Thermal recording layer 3 Support 4 Thermal recording layer 5 Surface protective layer 6 Recording heat beam 7 Incident direction 10 Reproducing light beam 11 Light receiving element 17 Recording medium 20 Micro transmission part 30 Transmission optical path 40 Micro transmission part θr Incident angle ψ Transmission angle

Claims (10)

[Claims] 1. A light-transmissive support, a light-impervious heat-sensitive recording layer which is provided on at least both front and back surfaces of the support and becomes light-transmitting when irradiated with a recording heat beam, and each heat-sensitive recording layer. A heat-sensitive recording medium, comprising: a light-transmitting protective layer provided on each surface thereof. 2. The support comprises two or more light-transmissive base materials,
2. A light-impermeable heat-sensitive recording layer which is interposed between these light-transmissive base materials and becomes light-transmissive when irradiated with a recording heat beam. Thermal recording medium. 3. The heat-sensitive recording medium according to claim 1, wherein the heat-sensitive recording layer absorbs a heat beam for recording. 4. The support and the protective layer have heat resistance to withstand the recording temperature of the thermosensitive recording layer.
4. The heat-sensitive recording medium according to any one of 3 to 3. 5. A light-transmissive support, and a micro-transmission part for light incidence formed on one of the front and back surfaces of the support, and a micro-transmission part for light emission on the other. These are a pair of light-impermeable recording layers whose recording information is the position and transmission angle of the transmitted light path composed of a pair of minute transmission parts and a support, and the light transmission properties provided on the surface of each recording layer. And a protective layer of the recording medium. 6. The support comprises two or more light-transmissive substrates.
6. A light-impermeable thermosensitive recording layer which is interposed between these light-transmissive substrates and becomes light-transmissive when irradiated with a recording heat beam. recoding media. 7. The recording medium according to claim 5, wherein at least one of the support and the protective layer blocks light having a wavelength different from that of the reproduction light beam. 8. The heat-sensitive recording layer is irradiated with a recording heat beam from at least one protective layer side of the heat-sensitive recording medium according to any one of claims 1 to 4, and each of the heat-sensitive recording layers is provided with a light-transmitting minute transmitting portion and a light. A minute transmission portion for emission is formed, and a position and a transmission angle of a transmission optical path formed by a pair of minute transmission portions and a support provided in each thermosensitive recording layer are recorded as recording information to obtain a recording medium, In this recording medium, a light receiving element is arranged on the side of the heat-sensitive recording layer on which the light transmitting minute transmitting portion is formed, and a reproducing light beam is emitted from the side of the heat sensitive recording layer on which the light incident minute transmitting portion is formed to transmit a light path. A recording / reproducing method, characterized in that the position and the transmission angle are detected and the recorded information is reproduced. 9. The light source for the recording heat beam and the reproducing light beam is constituted by a single wavelength light source, and the depth of focus thereof is substantially equal to or more than the thickness dimension of the heat sensitive recording medium and the recording medium. The recording / reproducing method according to claim 8, which is characterized in that: 10. The beam diameter of the recording heat beam and that of the reproducing light beam are substantially equal to each other.
Recording / playback method described.