JP2000222741A - Information read preventing device for optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispose of an optical disk easily and safely with good operability without causing information recorded on the optical recording medium to leak. SOLUTION: When the optical disk 10 is driven at a constant linear velocity(CLV), a control part 34 turns on and controls a light heating part 20 so that the output is constant. The control part 34 controls a spindle motor by a spindle driving part 30 so that the rotating speed is larger toward the disk inner peripheral side. At the same time, the control part 34 drives a stepping motor by a stepping driving part 32 to move the light heating part 20 from the inner peripheral side to the outer peripheral side (and vice versa) of the optical disk 10. Then a coloring matter layer of the optical disk 10 irradiated with light by the light heating part 20 abruptly rises in temperature and the coloring matter is chemically destroyed with the heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading prevention device for an optical recording medium for preventing reading of information recorded on an optical recording medium (optical recording medium) such as a CD or DVD.

[0002]

2. Description of the Related Art There are various types of information recording media such as disks and tapes, and optical recording media such as CDs and DVDs are widely spread as media that can be supplied in large quantities at low manufacturing costs. In particular, CD-Rs and DVD-Rs, which are so-called write-once, can record information only once, but rather utilize their properties to represent important documents represented by public documents that cannot be tampered with. Used to record information. Also, since a large amount of information can be easily recorded and stored, it is also used personally and at home.

When discarding an optical disc on which information has been recorded, since the information once recorded cannot be erased on the above-described CD-R or the like, the disc itself is discarded. At this time, if the information recorded on the disc to be discarded is important and has confidentiality, it is necessary to prevent the recorded information from being read so as not to leak the information.

[0004] As a conventional information reading prevention method, first,
There is a method in which a dye layer, which is a recording layer, is peeled from an optical disk substrate by pressing a heated plate against an optical disk to separate the dye layer and the lacquer layer. In this method, the optical disk itself is disassembled, and as a result, information cannot be read. On the other hand, there is a method of providing a plurality of claws on a roller, such as a music box, thereby physically scratching the optical disc. In this method, even if the optical disk is set in a reading device due to a scratch on the disk surface, the optical path of the reading laser beam changes due to the scratch on the disk surface, and reading of information is hindered.

[0005]

However, such background arts have the following disadvantages. First, in the former method of press-fitting a heating plate, it is necessary to preheat the plate for press-fitting, and there is an inconvenience that time is required for work. On the other hand, in the latter method using nails, the work itself is simple, and the work time is short. However, due to the physical destruction of the optical disk, it is possible to partially read out information depending on the degree of damage, and there is a danger of information leakage. In addition, it is necessary to consider the influence of dust and the like generated at the time of forming a flaw.

The present invention focuses on the above points,
It is an object of the present invention to provide an information readout prevention device that can easily and safely discard an optical disk without causing leakage of information recorded on an optical recording medium.

[0007]

In order to achieve the above object, the present invention relates to a method for reading information from an optical recording medium having a dye layer on which information is recorded laminated on a substrate, by erasing the information or controlling the reading light. An information reading prevention device for an optical recording medium, which prevents the reading of the information by changing the optical path; an optical heating means for outputting light for heating the dye or the substrate; a rotating means for rotating the optical recording medium; the optical heating means and the light Moving means for moving one of the recording media in a substantially radial direction of the optical recording medium; the light heating means so that light output from the light heating means scans an information recording surface of the optical recording medium; , The rotating means, and control means for controlling the operation of the moving means.

According to one of the main modes, the control means controls the rotating means so that the optical recording medium rotates at a constant linear velocity, and controls the output of the light heating means to be constant. Is controlled. According to another aspect, the control means controls the rotating means so that the optical recording medium rotates at a constant angular velocity,
The output of the light heating means is controlled so as to correspond to the linear velocity of the optical recording medium. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

[0009]

Embodiments of the present invention will be described below in detail. FIG. 1A shows a mechanical configuration of the first embodiment. In FIG. 1, an optical disk 10 to be processed is rotatably mounted on a rotating shaft 14 of a spindle motor 12. As shown in FIG. 1B, for example, the optical disk 10 includes
It has a laminated structure sandwiched between B and the reflective layer 10C.
Information is recorded by irradiating the dye layer 10A with a laser beam to cause a phase change or the like.

Next, in this embodiment, an optical heating unit 20 is provided to erase information recorded on the optical disk 10. The light heating unit 20 includes a light source 22 and a condensing optical system 24, and the light output from the light source 22
Thus, light is collected near the dye layer 10A of the optical disk 10 and the dye layer 10A is heated. The size of the spot on the optical disk 10 of the light source 22 is larger than the laser beam spot when information is recorded on the optical disk 10, and has a size extending over a number of tracks. The light heating unit 20 is configured to slide on a slide shaft 28 in the disk radial direction by a stepping motor 26. As the light source 22 of the light heating unit 20, a halogen lamp or the like is suitable.

FIG. 2A shows an electrical configuration of the first embodiment. The spindle motor 12 described above
Are driven by a spindle drive unit 30, and the stepping motor 26 is driven by a stepping drive unit 32. These driving units 30 and 32 are connected to a control unit 34 together with the light source 22 of the light heating unit 20. The control unit 34 controls the drive of the spindle motor 12 and the stepping motor 26 so that the beam spot output from the light heating unit 20 moves on the information recording surface of the optical disk 10 in a substantially radial direction.

Next, the operation of the present embodiment will be described. When the optical disk 10 is driven at a constant linear velocity (CLV), the light heating unit 20 is turned on and controlled by the control unit 34 so that the output is constant. The control unit 34 includes the spindle driving unit 3
A value of 0 controls the spindle motor 12 so that the rotation speed increases toward the inner circumference of the disk. At the same time, the control unit 34 drives the stepping motor 26 by the stepping drive unit 32 and causes the optical heating unit 20 to
0 from the inner circumference to the outer circumference (or vice versa). Then, the temperature of the dye layer 10A of the optical disk 10 irradiated with light by the light heating unit 20 rises rapidly, and the dye is chemically destroyed by heat. For example, when a cyanine dye is used as a dye, it is completely destroyed when the temperature is 350 ° C. or higher. At this time, the polycarbonate also melts. That is, the optical path of the laser light inside the optical disk changes (including destruction).

On the other hand, the optical disk 10 is rotated at a constant angular velocity (CA).
When driving in V), the spindle drive unit 30 is controlled by the control unit 34 so that the rotation speed of the spindle motor 12 is constant. In this case, the optical disk 10
The linear velocity becomes higher toward the outer periphery of. For this reason, the control unit 34
Is such that the output of the light heating unit 20 corresponds to the linear velocity of the disk at the incident position of the output beam spot of the light heating unit 20, that is, the output of the light heating unit 20 increases toward the outer periphery of the disk.
Control. Then, the stepping motor 26 is driven by the stepping drive unit 32 to move the optical heating unit 20 from the inner peripheral side of the optical disc 10 to the outer peripheral side (or vice versa). As a result, similarly to the case where the linear velocity is constant, the temperature of the dye layer 10A of the optical disk 10 irradiated with light by the light heating unit 20 rises rapidly, and the dye is heated by heat as shown in FIG. Chemically destroyed.

In both cases of CLV and CAV, the beam spot of the light heating unit 20 irradiates a large number of tracks at the same time, so that the time required to scan the entire disk is longer than in the case of ordinary information recording. It will be a short time. Further, no preparation time such as residual heat is required, and the reading of information can be completely disabled because the chemical dye is destroyed.

FIG. 2B shows a second embodiment of the present invention. In this embodiment, the stepping motor 26 and the slide shaft 28 are provided on the optical disk 10 side,
The optical disk 10 is configured to move with respect to the light heating unit 20. That is, the stepping drive unit 50 is provided on the optical disk 10 side. Then, the control unit 52 rotates and moves the optical disk 10. Others are the same as the first embodiment.

FIG. 3 shows still another embodiment. In this embodiment, a temperature sensor 60 for detecting the temperature of the optical disk 10 or its vicinity and a light amount monitor 62 for detecting the output light amount or light intensity of the light heating unit 20 are provided. Have been.
When the temperature of the optical disk 10 is high, for example, when the temperature is high, or when the temperature is increased by performing the information erasing process, the dye is satisfactorily destroyed even if the output of the light heating unit 20 is reduced accordingly. (The polycarbonate substrate may not be destroyed). Further, by reducing the output, the life of the light source 22 of the light heating unit 20 can be extended. Therefore, in the present embodiment, the control unit 64 controls the output of the light source 22 based on the measurement result by the temperature sensor 60. On the other hand, depending on the lamp used as the light source 22, the output light quantity gradually decreases due to so-called aging. Therefore, the output light amount of the light source 22 is detected by the light amount monitor 62 and is controlled by the control unit 64 so that the output required for the destruction of the dye is obtained.

The present invention has many embodiments, and various modifications can be made based on the above disclosure. For example, the following is also included. The present invention is applied to the CD-R
And DVD-R are preferable examples. However, CD- and DVD-ROMs, and CD-ROMs in which information can be repeatedly written and read many times.
The present invention is also applicable to other optical recording media such as RW and DVD-RW. The information readout prevention device according to the present invention may be incorporated in a driver for reading or writing information on an optical recording medium. In the case where information is recorded on the front and back of the optical recording medium, erasing information and changing the optical path can be performed in a short time by providing light heating means on each of the front and back of the optical recording medium. Even when information is recorded on only one surface of the optical recording medium, the work time for erasing information or changing the optical path can be reduced by providing two or more light heating means. In the above embodiment, the case of CLV and CAV has been described.
ZC that rotates an optical recording medium at a constant linear velocity for each constant zone
The same applies to the case of LV or the like, as long as the temperature rise at which the dye or the substrate is destroyed occurs.

[0018]

As described above, according to the present invention,
The following effects are obtained. Since the dye or the substrate in the optical recording medium is destroyed or deformed by the temperature rise by the light heating means, it is possible to prevent reading of the recorded information and safely discard the optical disk. Since the dye or the substrate is heated by the light, preparation such as preheating is not required, and the operation is easy and good.

[Brief description of the drawings]

FIG. 1 is a diagram showing a mechanical configuration of a first embodiment of the present invention and a basic layer configuration of an optical disc.

FIG. 2 is a block diagram showing an electrical configuration of the first and second embodiments.

FIG. 3 is a block diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Optical disk 10A ... Dye layer 10B ... Substrate 10C ... Reflection layer 12 ... Spindle motor 14 ... Rotating axis 20 ... Light heating part 22 ... Light source 24 ... Condensing optical system 26 ... Stepping motor 28 ... Slide shaft 30 ... Spindle drive part 32 ... Stepping drive unit 34 ... Control unit 50 ... Stepping drive unit 60 ... Temperature sensor 62 ... Light amount monitor 64 ... Control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroo Shimizu 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Electric Power Co., Inc. (72) Inventor Yukihide Omura 6-16-20 Ueno, Taito-ku, Tokyo Taiyo (72) Inventor Akira Negishi 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Co., Ltd. (72) Inventor Hironobu Shimizu 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Invitation (72) Inventor Shino Sekiguchi 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction (72) Inventor Yoshikazu Takagishi 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Invitation F term (for reference) in Denki Co., Ltd. 5D090 BB12 CC03 CC16 DD03 DD05 EE06 FF09 HH03 KK03 KK18 LL07

Claims (3)

[Claims] 1. An information readout prevention device for an optical recording medium, which prevents reading of information from an optical recording medium in which a dye layer on which information is recorded is laminated on a substrate by erasing the information or changing the optical path to the reading light. Light heating means for outputting light for heating the dye or the substrate; rotating means for rotating the optical recording medium; one of the light heating means and the optical recording medium having a diameter substantially equal to the diameter of the optical recording medium. Moving means moving in the direction; control for controlling the operations of the light heating means, the rotating means, and the moving means such that the light output from the light heating means scans the information recording surface of the optical recording medium. Means for preventing reading of information from an optical recording medium. 2. The control means controls the rotating means so that the optical recording medium rotates at a constant linear velocity, and controls the output of the light heating means to be constant. An apparatus for preventing information reading from an optical recording medium according to claim 1. 3. The control means controls the rotation means so that the optical recording medium rotates at a constant angular velocity, and controls the output of the light heating means so as to correspond to the linear velocity of the optical recording medium. 2. The information reading prevention device for an optical recording medium according to claim 1, wherein: