JPS63193340A - Information recording medium - Google Patents

Abstract

PURPOSE:To permit easy and sure decision of the posture at which an information recording medium is inserted to a recording and reproducing device and whether the recording medium is true or false by forming a phase type diffraction grating to at least part of a layer boundary to which light can be projected from the surface. CONSTITUTION:This optical card 1 is constituted by adhering a substrate 37 consisting of a resin such as polycarbonate and a transparent resin substrate 34 consisting of polycarbonate, etc., partially attached with an optical information recording layer 35 by an adhesive layer 36. The diffraction grating 33 of a phase type is formed at the boundary between the transparent substrate 34 and the recording layer 35. This diffraction grating is easily formed by previously forming a grating shape partly on one face of a mold at the time of forming the transparent substrate 34 by a molding method such as compression. The posture at which the information recording medium is inserted into the recording and reproducing device, whether the recording medium is true or false and the kind of the recording medium are thereby easily and surely decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an information recording medium, and more particularly to an information recording medium having, in addition to main purpose information, recorded information for one purpose that can be easily detected optically. Such an information recording medium is suitably applied, for example, to an optical information recording medium in which the main objective information is optically recorded and/or optically recorded.

[Prior Art and its Problems] Conventionally, an optical type has been used, which records information on a recording medium and/or reproduces information recorded on the recording medium while irradiating the surface of the information recording medium with a laser beam. Information recording and reproducing methods have been put into practical use.

Information recording media used in such optical information recording and reproducing systems include card-like or sheet-like media in which a large number of linear information tracks each consisting of an appropriate number of information bit strings are arranged in parallel; There are disc-shaped discs in which information tracks consisting of bit strings are arranged in a spiral or concentric circle, and each type is designed according to the purpose.

Here, the above-mentioned card-like medium (hereinafter referred to as "
An example of optical information recording and reproducing using an optical card (hereinafter referred to as "optical card") will be explained.

FIG. 4 is a block diagram showing the configuration of an apparatus for recording information on an optical card and/or reproducing information recorded on the optical card.

In FIG. 4, l is an optical card, and the optical card is B
It is stored and fixed on the shuttle 5 in an attitude perpendicular to the direction. The optical card l is provided with an information recording area, in which a large number of incoming information tracks are arranged in parallel in the C direction.

22 and 23 are bootsaws, and a belt 24 is wound between these pulleys, and the shuttle 5 is attached to the belt.
is fixed = The pulley 22 is attached to the shaft of a drive motor 26, and the forward or reverse rotation of the motor causes the belt 24 to travel, thus allowing the shuttle 5 to reciprocate in the incoming direction.

On the other hand, 3 is an optical head, which includes a semiconductor laser 8 as a light source, a collimator lens 9, a polarizing beam splitter 10, a quarter wavelength plate 30, and an objective lens 11.
, a built-in optical sensor 12. The optical head 3 can be moved intermittently in the C direction by a stepping motor 21.

The light from the laser 8 passes through a collimator lens 9 and then a polarizing beam splitter 1O and a 1/4 wave plate 30.
and is focused as a light beam 4 by the objective lens it to form a minute spot on the optical card l. The light beam reflected by the optical card l passes through the objective lens 11,
The beam then passes through a 1/4 wavelength plate 11, is further reflected by a polarizing beam splitter 10, and is sent to an optical sensor.
Reach 12.

The output of the optical sensor 12 is input to a preamplifier 13, and the focusing deviation signal and tracking deviation signal obtained here are input to an autofocusing servo means 14 and an autotracking servo means 15, respectively. A command is issued to the drive mechanism to move the objective lens (11) in directions B and C, respectively, and perform autofocusing and autotracking.

On the other hand, the information reproduction signal obtained by the preamplifier 13 is input to a decoder 16, and the output of the decoder is input to a computer 18 via an interface 17.

A command signal for the laser 8 is emitted from the computer 18, and the signal is transmitted to the interface 17.
．． Enco! -19, further passes through the laser driver 20 and reaches the laser 8. In addition, the computer 1
8 issues a command signal for the stepping motor 21, which signal reaches the stepping motor 21 via the interface 17. Furthermore, the computer 18 issues command signals for the drive motor 26, which signals are transmitted to the motor servo means 27.
The motor 26 is reached via the motor 26.

In the above-described recording and reproducing apparatus, information is recorded on the optical card 1 or information recorded on the optical card 1 is reproduced by moving the optical card 1 back and forth in the input direction at a predetermined stroke while operating the semiconductor laser 8. This is carried out by intermittently moving the radar 3 in the C direction.

Incidentally, information recording and reproduction is performed after the optical card l is loaded into a predetermined area within the recording and reproduction apparatus.

FIGS. 5(a), 5(b), and 5(c) are schematic perspective views for explaining such optical card loading.

The optical card l having the recording area 2 is manually inserted into the card insertion slot 61 of the recording and reproducing device in the direction A, and then a transport mechanism (not shown) in the device is used to record and reproduce information below the optical disk 3. The optical card 1 is transported into the area R, and recording and reproduction is performed within this area R by reciprocating the optical card l in the input direction as described above and further moving the optical head 3 intermittently in the direction C. .

Incidentally, there are several postures for the optical card 1 to be inserted from the card insertion slot 61, as shown in FIGS. 5(a) to 5(C). That is, in addition to the case where it is inserted in the normal position as shown in Fig. 5(a), there are cases where it is inserted in the reverse direction as shown in Fig. 5(b), and cases where it is inserted in the reverse direction as shown in Fig. 5(C). It may be inserted upside down as shown.

In order to simplify the configuration of the recording/reproducing device and the recording/reproducing method, it is necessary to set the card insertion position in such a way that the optical card l is ejected from the insertion slot 61 unless the card insertion position is as shown in FIG. 5 (11). It is preferable to

In order to determine whether such an insertion error has occurred, the optical card L may be transported to the recording/reproducing area R, and then the optical head may perform a reproducing operation, and the card orientation may be determined from the format of the information being reproduced. However, this method has the disadvantage that if the card orientation is not normal, transportation, recording and reproducing are wasted and the efficiency is low.

On the other hand, in recent years, with the spread of card-type information recording media, counterfeiting has become a problem. As a countermeasure against counterfeiting, an encryption code, etc. is recorded on the card in the same format as the main purpose information recording format (i.e., in the case of an optical card, the format that is reproduced by the optical head mentioned above). After the card is loaded into the playback device, the recorded information on the card is played back and the determination can be made based on whether predetermined code information is recorded.

However, such a card authenticity determination method is carried out after the -H card is conveyed to the recording/reproducing area, and therefore has the drawback of low efficiency.

Therefore, an object of the present invention is to provide an information recording medium that makes it possible to easily and reliably determine the insertion posture of the information recording medium into a recording/reproducing apparatus and to easily determine the authenticity of the recording medium. purpose.

[Means for Solving the Problems] According to the present invention, the above objects are achieved.

In an information recording medium having a plurality of layers, at least one of which is an information recording layer, a phase-type diffraction grating is formed at least in part of the layer boundaries through which light can enter from the surface. An information recording medium is provided.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1(L) is a schematic plan view showing one embodiment of the information recording medium according to the present invention, and FIG.
This embodiment, which is a -x sectional view, is an example in which the recording medium is an optical card.

As shown in FIG. 1(a), an optical card 1 has a predetermined area 2 as an information recording area. An appropriate logo 32 can be attached to areas other than the recording area so that the user can visually determine the type, purpose, etc. of the card.

As shown in FIG. 1(b), the optical card 1 has a substrate 37 made of a resin such as polycarbonate and a transparent resin substrate 34 made of polycarbonate or the like on which an optical information recording layer 35 is partially attached. It has a structure in which it is bonded by an agent layer 36.

A phase type diffraction grating 33 is partially formed at the boundary between the transparent substrate 34 and the recording layer 35 .

The diffraction grating can be easily formed by partially forming a grating shape on one side of the mold surface when the transparent substrate 34 is produced by a molding method such as compression.

In this embodiment, the diffraction grating 33 is formed not on the surface of the optical card l, but at the boundary between the two layers, so that when the optical card is used, foreign matter such as dirt and dust may enter the diffraction grating portion, resulting in an accurate grating. There is no loss of shape.

As shown in FIG. 1(&), the diffraction grating 33 is arranged biased to the left side of the card surface.

FIG. 2 is a schematic perspective view showing a part of the apparatus for recording and reproducing information on the optical card 1 of the above embodiment. In particular, this figure shows the area around the optical card transport mechanism.
The function of the diffraction grating 33 formed on the optical card 1 will be explained with reference to this figure.

When the optical card l is inserted through the opening 62 of the card insertion slot 61, the sensor 63 detects the entry of the optical card, and the motor 64 rotates the pulley 65. When the optical card 1 is further pushed in, the leading end of the optical card is sandwiched between rollers 66 and 67, and is guided by a guide means (not shown) and sent in the entry direction.

At this time, the shuttle 5 is in a position where the protrusion 68 engages with the recess 69, and the roller 71.
72 is included. When the motor 64 further rotates, the optical card l is pushed by the rollers 71 and 72 and inserted into the shuttle 5 until it hits the stopper 73, and the sensor 63
detects the entry of the optical card l, and after a certain period of time motor 6
4 stops.

74 is a light source such as an LED, and 52a and 52b are optical sensors. FIGS. 3(a) and 3(b) are schematic perspective views for explaining the functions of the light source 74 and the optical sensor.

As also shown in FIG. 3, the optical sensor 52&.

52b is arranged symmetrically with respect to the position of the light source 74 in the C direction. The position of the light source is arranged to correspond to the portion of the diffraction grating 33 with an optical power of -11 in the C direction, and light is emitted downward from the light source. Therefore, as the optical card 1 advances, the light source 74
When reaching the lower part of the light source 74, first, as shown in FIG. 3(a), the portion other than the diffraction grating 33 is located directly below the light source 74, and at this time, only the specularly reflected light 41 is reflected toward the light source.

Then, the card l advances gradually, and as shown in FIG. 3(b), the part of the diffraction grating 33 is located directly below the light source 74, and at this time, the light is reflected and diffracted by the diffraction grating. Of the light, the θ-time diffracted light (regularly reflected light) 41 travels toward the light source, but the first-order diffracted lights 42a and 42b travel toward optical sensors 52a and 52b, respectively, thereby detecting the diffraction grating position. . .

Therefore, from the time from the time when the optical card insertion is detected by the sensor 63 in FIG. If the optical card l is inserted upside down, the optical sensors 52a, 5
Since no light is detected by 2b, this can also be determined.

Therefore, according to this embodiment, the card insertion posture can be easily and reliably determined before transporting the optical card 1 to the information recording/reproducing area.

When it is determined that the optical card l has been inserted in the normal position, the solenoid 75 moves to the lever 76 in FIG.
Pull the recess 69 of the lever 77 and the protrusion 68 of the shuttle 5.
At the same time, disengage with.

Or after a certain period of time, the motor 78 rotates and the shuttle 5
Recording/reproducing area R (lower position of optical head 3 shown)
After that, information is recorded and reproduced by the optical radar 3.

On the other hand, if it is determined that the optical card l has been inserted in an incorrect orientation other than the normal orientation, the motor 64 is rotated in the opposite direction to that at the time of insertion, and the card is ejected from the insertion slot 61. At this time, it is also possible to display using a display means for the purpose of making the user aware that a card insertion abnormality has occurred.

Note that the determination means consisting of the light source wave 74 and the optical sensors 52a and 52b is connected to the shuttle 5 which is in a standby state when the optical card is inserted.
By placing the optical card above the shuttle, it is possible to detect whether the optical card is attached to the shuttle. That is, when the optical card l is installed in the shuttle 5 with an inclination,
The amount of light detected by the optical sensors 52a and 52b is different, and the inclination angle can be determined based on the difference in the amount of light or the ratio of the amount of light, and if the angle exceeds an allowable value, it can be determined that the installation is defective.

Further, by making the diffraction grating 33 of a blazed type and concentrating the diffracted light in a specific direction, it is possible to use only one photodetector and further improve the detection S/N.

Also, depending on whether the diffracted light from the diffraction grating 33 in this embodiment is detected by the optical sensors 52a and 52b,
It is also possible to determine the authenticity of optical cards. That is, it can be determined that an optical card in which no diffracted light is detected by the optical sensor is not a genuine card. If the card is determined to be a fake,
The card can be ejected in the same manner as in the case of the incorrect insertion position.

In the above embodiment, a case is shown in which the diffraction grating 33 is placed at the center of the card l in the C direction, but the position of the diffraction grating is not particularly limited and may be placed outside the recording area 2. Often, a determination means may be disposed in the recording/reproducing apparatus corresponding to the position of the diffraction grating, and various determination formats change depending on the position of the diffraction grating. For example, if the diffraction grating section is not at the center of the card in the C direction.

When the insertion posture is reversed, no light is detected by the optical sensors 52a and 52b, as in the case of upside-down insertion.

According to the recording medium of the present invention, depending on the type of the diffraction grating portion,
It is also possible to determine the type of recording medium. For example, when recording on two types of recordable optical cards with different recording sensitivities using the same recording/playback device, it is necessary to determine the type of the optical card and set the light source light amount appropriately according to the type. However, among the diffraction gratings 33 in the above embodiment, one is a blazed grating so that the diffracted light travels only toward the optical sensor 52a, and the other one is a blazed grating that allows the diffracted light to travel only toward the optical sensor 52b. By using a blazed grating that moves forward, the type of optical card can be determined based on which sensor detects the light.

Although the above embodiment shows a case where the diffraction grating section is formed at one location, the present invention may also include the diffraction grating section being formed at two or more locations. Furthermore, it is also possible to detect the diffracted lights from these two or more diffraction grating portions, respectively, and perform various determinations based on a combination of these detection results.

At this time, a plurality of diffraction grating sections are provided along the card insertion direction, and various diffraction gratings can be made depending on the number of the grating sections, or each grating section is a blazed grating with different directionality and the order of arrangement of the grating sections, etc. A relatively short piece of information for one purpose can be recorded.

Although the above embodiment is a case where the diffraction grating is of a reflective type, the present invention can be similarly applied to a case where the diffraction grating is a transmission type.

Furthermore, although the above embodiments have been described in the case where the information recording medium is an optical card, the present invention is applicable to optical information recording media in the form of disks or other forms, or information recording using other recording methods such as magnetic recording. The same applies to media.

[Effects of the Invention] According to the present invention as described above, since the information recording medium has a diffraction grating which is a recording format different from the information recording format which is the main purpose of the information recording medium, the recording medium can be used for the above-mentioned main purpose of information recording and reproduction. The layer purpose information can be detected quickly and efficiently immediately after the medium is inserted without having to transport the medium to the storage area.This makes it easy to easily and reliably determine the insertion posture of the information recording medium into the recording/reproducing device and to easily check the true state of the recording medium. It is possible to determine whether the information is false or to easily and reliably determine the type of recording medium.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1(a) is a schematic plan view showing one embodiment of the information recording medium according to the present invention, and FIG. 1(b) is a schematic plan view of the information recording medium according to the present invention.
-x sectional view. FIG. 2 is a schematic perspective view showing a part of an apparatus for recording and reproducing information on an optical card. FIGS. 3(a) and 3(b) are schematic perspective views for explaining the functions of the light source and the optical sensor. FIG. 4 is a block diagram showing the configuration of the optical card information recording/reproducing device. FIGS. 5(a), 5(b), and 5(c) are schematic perspective views for explaining loading of an optical card. l: optical card, 2: recording area. 3: Optical head, 33: Diffraction grating, 34: Transparent resin substrate. 35: Information recording layer, 36: Adhesive layer, 37: Resin substrate. 52a, 52b: optical sensor, 61: optical card insertion slot. 74: Light source. Agent Patent Attorney Seki Yamashita Figure 1 (b) Figure 3 (o) Figure 3 (1))

Claims (5)

[Claims] (1) In an information recording medium having a plurality of layers, at least one of which is an information recording layer, a phase-type diffraction grating is formed at at least a portion of the layer boundaries through which light can enter from the surface. An information recording medium characterized by: (2) The information recording medium according to claim 1, wherein the diffraction grating is a blazed diffraction grating. (3) The information recording medium according to claim 1, wherein the diffraction grating is formed at a plurality of locations. (4) The information recording medium according to claim 1, which is in the form of a card. (5) The information recording medium according to claim 1, wherein at least one of the information recording layers is a layer in which information can be optically recorded and/or information is optically recorded.