JPH0714166A - Method for recording information on optical information medium - Google Patents

Abstract

PURPOSE:To provide a method for recording information on an optical information medium capable of recording the information on an information recordable area of the optical information medium by using a laser with a low output. CONSTITUTION:At the time of recording information on the information recordable area 1B, by a system controller 241, a spindle motor 242 is driven, and an optical disk 1 is rotated at a prescribed rotational speed lower than the speed at the time of reproducing the information, e.g. a linear velocity of 0.6m/s being 1/2 of the linear velocity of a CD standard of 1.2m/s and a write signal length is set double the length at the time of reproducing the information. Further, the effective output of the laser of an optical pickup 243 is set to a prescribed value higher than the value at the time of reproducing, e.g. 1.6mW, and the information is written. Thus, the constitution of an information recording device or an information recording/reproducing device for the optical disk 1 is simplified and the cost is reduced, and the optical disk 1 provided with an information reproducing exclusive area 1A and an information recordable area 1B can be spreaded accompanying that the cost of these devices is made low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recording information on an optical information medium having an information reproduction exclusive area and an information recordable area, and more particularly, information recording for recording information using a low output laser for information reproduction. It is about the method.

[0002]

2. Description of the Related Art Conventionally, a compact disc (hereinafter referred to as a CD
Information) recorded on an optical information medium such as a CD player or the like, and a reproduction-only optical information medium in which a metal thin film such as aluminum and a protective film are formed on a substrate on which pits are formed. A playback-only device for playing back is generally known.

Further, a metal thin film of aluminum or the like and a protective film are provided on the substrate as an area exclusively for reproducing information, a dye film is interposed as an information recordable area on the same main surface, and a metal thin film of aluminum or the like and a protective film are provided on the main surface. An optical information medium having a protective film has been proposed, and it has become possible to record user-specific information in the information recordable area.

[0004]

However, when information is recorded in the information recordable area using the optical information medium having the above-mentioned information reproduction-dedicated area and the information recordable area, a high information recording area is used. Due to the need for an expensive recording device equipped with an output laser, its widespread use has been delayed. That is, if only reproducing information, a low-priced laser having an effective output (strength on the disc surface) of about 2 mW, which is used in a CD player, may be provided, but if recording information, an optical laser is used. In order to obtain a sufficient amount of heat to thermally change the recording layer of the information medium, an expensive laser having an effective output of 20 to 30 mW must be provided.

In view of the above problems, an object of the present invention is to provide an information recording method for an optical information medium, which can record information in an information recordable area of the optical information medium using a low-power laser. It is in.

[0006]

In order to achieve the above-mentioned object, the present invention provides the information reproducing-only area in which predetermined information is recorded in advance on the inner circumference side in order to achieve the above object.
In an information recording method for an optical information medium having a disc shape in which an information recordable area capable of recording information at any time is formed on the outer peripheral side, in the information recording in the information recordable area, the information reproduction in the information reproduction dedicated area is performed. The output intensity of the laser used at the time is set to a predetermined value higher than that at the time of information reproduction, and a laser beam is emitted from the laser to the information recordable area at a predetermined linear velocity slower than that at the time of information reproduction of the information reproduction dedicated area. We propose a method of recording information on an optical information medium by irradiating and recording information.

Further, according to a second aspect of the present invention, an information reproduction-only area in which predetermined information is recorded is formed on the inner circumference side, and an information recordable area on which information can be recorded at any time is formed on the outer circumference side. In the information recording method on an optical information medium having a shape, at the time of recording information in the information recordable area, the output intensity of the laser used during information reproduction in the information reproduction exclusive area is set to a predetermined value higher than that during information reproduction. A method for recording information on an optical information medium is proposed, in which information is recorded by setting a laser beam from the laser to the information recordable area at an information density lower than the information density in the information reproduction only area.

[0008]

According to the first aspect of the present invention, when information is recorded in the information recordable area of the optical information medium, the output intensity of the laser used for information reproduction in the information reproduction exclusive area is higher than that during information reproduction. The information is recorded by setting the value to a value and irradiating the information recordable area with laser light from the laser at a predetermined linear velocity slower than that at the time of reproducing the information in the information reproduction exclusive area. As a result, for example, when the linear velocity at the time of recording information is ½ of the linear velocity at the time of reproducing information, the amount of heat supplied to the laser light irradiation position of the optical information medium becomes sufficient for forming pits, and the degree of modulation. And a good pit can be formed. Therefore, it is possible to record information in the information recordable area by using the low power laser used for reproducing information.

According to the second aspect, when information is recorded in the information recordable area of the optical information medium, the output intensity of the laser used for information reproduction in the information reproduction exclusive area is higher than that during information reproduction. The information is recorded by setting the value to a value and irradiating the laser beam from the laser to the information recordable area at an information density lower than the information density in the information reproduction only area. For example, the amount of information recorded per unit area of the optical information medium decreases by decreasing the transfer rate of the recording signal that changes the laser output intensity during information recording and lengthening the signal. The amount of heat supplied to the laser light irradiation position on the medium is sufficient for forming pits. As a result, it is possible to record information in the information recordable area with a laser beam having a low output intensity by using a low output laser used for reproducing information.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an optical information medium used in this embodiment. In the figure, 1 is an optical information medium (hereinafter,
It is called an optical disk) and has a disk shape having a diameter of 12 cm, and an information reproduction exclusive area 1A is formed on the inner peripheral side thereof.
Further, an information recordable area 1B is provided on the outer peripheral side and is created as follows.

That is, pits having the same height and size of unevenness as the CD are formed on the inner peripheral side of the main surface, and about 1 outer peripheral side is formed.
A disc-shaped substrate having a width of cm and a depth substantially the same as that of the pit and having a spiral guide groove wobbling (swinging) at a predetermined cycle is formed by injection molding of polycarbonate.

Next, a predetermined dye coating liquid is applied to the guide groove portion of the substrate, for example, 1.1'dicaloxymethyl 3.3.3'.3 'tetramethylindotricarbocyanine chloride represented by the following chemical formula (1)
(2) 1.1'Diethyl 3.3.3'.3 'Tetramethyl 4.5.4'.5' Dicyclopentylindicarbaocyanine iodide mixed in a ratio of 1: 1 using a spin coater After coating, a direct aluminum reflection layer and a protective layer having a predetermined thickness are formed on the entire pits and guide grooves to complete the process. Further, an ATIP code (absolute time information) is recorded in the guide groove itself, and by detecting this ATIP code, the movement of the optical pickup described later can be accurately performed (Japanese Patent Laid-Open No. 5-5120).
6-105343, JP-A-63-87682, JP-A-63-10345).

[0013]

[Chemical 1]

[Chemical 2] Further, here, a dye having a high sensitivity is applied to the information recordable area 1B so as to cause deformation recording having a low reflectance and a high sensitivity.

FIG. 2 is a block diagram showing the optical information recording / reproducing apparatus in this embodiment. In the figure, 1 is the above-mentioned optical disc, 2 is an optical information recording / reproducing apparatus, and a data input / output unit 2
1, recording unit 22, reproduction unit 23, and system control unit 24
It consists of

The data input / output unit 21 includes an analog input / output interface 211, an analog / digital (hereinafter, A /
The converter 212 includes a D / D converter 212, a digital / analog (hereinafter referred to as D / A) converter 213, a digital input / output interface 214, and change-over switches 215 and 216. When the information to be recorded is supplied as an analog signal, this analog signal is input to the A / D converter 212 via the analog input / output interface 211 and converted into the digital signal DA1. When the information to be recorded is supplied by a digital signal, this digital signal is input to the digital input / output interface 214, and the changeover switch 21 is used as the digital signal DA2.
Entered in 5. The changeover switch 215 selects one of the digital signals DA1 and DA2 according to the supply state of the recording target information and outputs it to the data conversion unit 22.

When outputting the signal reproduced from the optical disk 1 as an analog signal, the signal inputted from the reproducing section 24 is inputted to the D / A converter 213 via the changeover switch 216 and converted into an analog signal. After that, it is output to the host device via the analog input / output interface 211.
When outputting the reproduction signal as a digital signal, the reproduction unit 2
The signal input from the No. 4 is output to the host device via the changeover switch 216 and the digital input / output interface 214.

Further, a digital input / output interface
Reference numeral 214 mediates transfer of control information between the higher-level device and the system control unit 24.

The recording unit 22 is a well-known EFM encoder 22.
1, a buffer memory 222, a synchronization circuit 223, and a recording correction circuit 224. The EFM encoder 221 is
The digital signal DA output from the data input unit 21 is EFM (Eight to Fourteen Modulation) modulated and output to the buffer memory 222. Also, the buffer memory 222
Sequentially accumulates the digital data output from the EFM encoder 221, and the system control unit 2 described later
4 outputs the accumulated digital data to the synchronizing circuit 223 based on the control signal from the system controller 241.

The synchronizing circuit 223 inputs the EFM-modulated digital data from the buffer memory 222, and based on the control signal from the system controller 241 and the clock signal CK from the signal processing circuit 244 described later, the input digital data. It is output at a predetermined timing synchronized with the clock signal CK.

The recording correction circuit 224 inputs the digital data output from the synchronizing circuit 223, responds to this digital data, and, based on the control signal from the system controller 241, sets the duty of the voltage and the pulse width to the optimum values. The recording signal set to (1) is generated and output to the optical pickup 233 described later.

The reproducing section 23 includes an analog waveform shaping circuit 231.
And a digital signal processing circuit 232.

The analog waveform shaping circuit 231 inputs the received light signal PS from the optical pickup 243, shapes the waveform, and converts it into a digital signal for output. The digital signal processing circuit 232 inputs the digital signal output from the analog waveform shaping circuit 231, performs error checking, and converts the digital signal into a predetermined format for output.

The system controller 24 includes a system controller 241, a spindle motor 242, and an optical pickup 243.
, Signal processing circuit 244, and tracking control circuit 245
It is composed by. System controller 241
Is provided with a CPU, a memory, and the like, and controls each unit based on control information input from the host device via the digital input / output interface 214. Further, the reproduction information converted into the digital signal output from the digital signal processing circuit 232 is input, and the tracking of the optical pickup 243 and the drive of the spindle motor 242 are driven based on the subcode information and the control information in the reproduction information. Take control.

The spindle motor 242 rotates the optical disc 1 at a rotation speed based on a control signal from the system controller 241.

As is well known, the optical pickup 243 is composed of a laser diode, a lens, a mirror, a photodetector, etc., emits a laser beam based on the recording signal output from the recording correction circuit 224, and reflects it from the optical disc 1. The light is received and a light reception signal PS corresponding to this is output. Further, the optical pickup 243 is configured to be movable so as to track the irradiation position of the laser light corresponding to the guide groove of the optical disc 1 based on the control signal from the tracking control circuit 245.

Here, the laser diode provided in the optical pickup 243 is similar to that used in a general-purpose CD player, and has a low output of, for example, an effective output of about 2 mW.

The signal processing circuit 244 includes an optical pickup 243.
The received light signal PS output from the
The focus control of the optical pickup 243 is performed based on S, the wobbling period of the guide groove (hereinafter referred to as a wobble signal) is detected from the light receiving signal PS, and the clock signal CK synchronized with the wobble signal is generated to generate the system controller 241. And to the synchronizing circuit 223. That is, when the rotation speed of the optical disc 1 changes and the detection period of the wobble signal changes, the period of the clock signal CK generated correspondingly also changes. Further, the signal processing circuit 244
The ATIP code is detected from the light receiving signal PS, and the absolute time based on the ATIP code is output to the system controller 241.

The tracking control circuit 245 moves the position of the optical pickup 243 based on the control signal from the system controller 241, and at the same time, the optical pickup 243.
The irradiation position of the laser light is tracked corresponding to the guide groove of the optical disc 1 based on the received light signal PS from. Further, when the tracking is lost, the tracking error signal ER is output and the system controller 241 is immediately notified of this.

According to the present embodiment having the above-described structure, when recording information in the information recordable area 1B, the system controller 241 drives the spindle motor 242 to rotate at a predetermined rotation speed lower than that at the time of reproducing information. For example, 1.2m /
The optical disc 1 is rotated at a linear velocity of 0.6 m / s, which is half the linear velocity of the CD standard of s, and the write signal length is set to double. Furthermore, the effective output of the laser of the optical pickup 243 is set to a predetermined value higher than that during reproduction, for example, 1.6.
Set to mW. As a result, a sufficient amount of heat for forming signal-reproducible pits is supplied to the laser light irradiation position in the information recordable area 1B.

When the optical disk 1 is rotated at a constant linear velocity (CLV), the linear velocity is set to 1.0 m / s or less, preferably 0.2 to 0.8 m / s. High-quality pits that can be easily reproduced can be formed, and good results have been obtained. Further, when the optical disc 1 is rotated at a constant rotation speed (CAV), good results are obtained when the rotation speed is 200 rpm or less, preferably 50 to 150 rpm.

When the information to be recorded is input through the data input / output unit 21, this information is temporarily stored in the buffer memory 222 as EFM-modulated data, and the data previously stored under the control of the system controller 241. Are sequentially output from the buffer memory 222. Further, the system controller 241 has a tracking control circuit 245.
Tracking is started from the information recording start position via.

As a result, the data output from the buffer memory 222 is synchronized with the clock signal CK by the synchronizing circuit 223, is output at a predetermined timing, and is converted into a recording signal by the recording correction circuit 224. Based on this recording signal, pulsed laser light is emitted from the optical pickup 243, and information is recorded in the information recordable area 1B of the optical disc 1.

Here, the linear velocity is 0.6 m / s and the signal length is 2
The sensitivity (pit formation rate due to the amount of heat supplied by the laser light) is about 1.4 times, and the signal length is relatively large compared to the spot size of the laser light. The degree can be increased. As a result, the dark portion on the optical disc 1 becomes darker and the bright portion becomes brighter, and high-quality pits that can be easily reproduced can be formed. Further, since the information recordable area 1B is fixed to the outer peripheral portion of the optical disc 1 having a width of 1 cm, the information recordable area 1B can be easily accessed by setting the physical position of the optical pickup 243. The relationship between the linear velocity and the rotation speed is limited, and the access control condition can be set easily.

Further, when the rotation of the optical disk 1 (rotation of the spindle motor 242) changes, the cycle of the clock signal CK generated by the signal processing circuit 244 also changes correspondingly. The cycle of the output recording signal is changed according to the rotation of the optical disc 1 (rotation of the spindle motor 242). At this time, under the control of the system controller 241, the data output with respect to the data input is temporally adjusted in the buffer memory 222. Further, although the optimum value of the laser output changes with the change of the rotation speed, the linear velocity, etc., under the control of the system controller 241, in the recording correction circuit 224, the laser output is the optimum value that matches the rotation number and the linear velocity of the optical disc 1. The voltage value of the recording signal and the duty of the pulse width are changed so that the value becomes a value. As a result, it is possible to reduce the occurrence of jitter and errors during reproduction of the information recorded on the optical disc 1, and it is possible to improve the stability of information reproduction.

On the other hand, when reproducing the information recorded in the information reproduction exclusive area 1A, the system controller 241
Sets the laser effective output of the optical pickup 243 to a value lower than that at the time of information recording, for example, about 0.2 mW, drives the spindle motor 242 at a linear velocity of 1.2 m / s of the CD standard, and controls the tracking control circuit. Tracking is started from the information reproduction start position via 245.

After that, the pits formed on the optical disc 1 are read by the optical pickup 243 and output as an electric signal as reproduction information. Optical pickup 24
The electric signal of the reproduction information output from 3 is input to the analog waveform shaping circuit 231 for waveform shaping, converted into a digital signal, and output to the digital signal processing circuit 232. The digital signal processing circuit 232 inputs the digital signal output from the analog waveform shaping circuit 231, performs error checking, etc.
Digital I / O interface after conversion to mat
It is output to the host device via 214.

When reproducing the information recorded in the information recordable area 1B, the system controller 241
Sets the laser effective output of the optical pickup 243 to a value lower than that at the time of information recording, for example, about 0.3 mW, and drives the spindle motor 242 at a linear velocity twice the linear velocity of 1.2 m / s of the CD standard. At the same time, tracking is started from the information reproduction start position via the tracking control circuit 245.
As a result, information can be reproduced without forming pits.

After that, the pits formed on the optical disk 1 are read by the optical pickup 243 and output as an electric signal as reproduction information, as described above. The electric signal of the reproduction information output from the optical pickup 243 is input to the analog waveform shaping circuit 231, the waveform is shaped, converted into a digital signal, and output to the digital signal processing circuit 232. Digital signal processing circuit 232
Receives the digital signal output from the analog waveform shaping circuit 231, performs an error check, etc., converts it into a predetermined format, and then outputs it to a higher-level device via the digital input / output interface 214. .

Also, by switching the switch 216, the digital signal output from the digital signal processing circuit 232 is converted into an analog signal by the D / A converter 213, and then output to the host device via the analog input / output interface 211. You can also do it.

As described above, according to the present embodiment, information can be reproduced by using an inexpensive low-power laser used in a general-purpose CD player, and the recording layer of the optical disk 1 can be recorded at the time of recording information. It is possible to obtain an amount of heat sufficient to change the heat of the pit, and it is possible to form a pit in which information can be reproduced as usual. As a result, it is possible to simplify the structure and reduce the cost of the information recording apparatus or the information recording / reproducing apparatus for the optical disc 1 having the information reproduction exclusive area 1A and the information recordable area 1B, and to reduce the cost of these apparatuses. Accordingly, the optical disc 1 having the information reproduction exclusive area 1A and the information recordable area 1B can be spread.

In the present embodiment, the optical information medium is the compact disc type optical disc 1, but the optical information medium is not limited to this, and may be a laser disc (LD).

In this embodiment, the linear velocity at the time of recording information is set to 0.6 m / s and the signal length is set to twice the CD standard, but the present invention is not limited to this.

Further, in the present embodiment, the information recording by the low power laser was made possible by decreasing the linear velocity, but the same effect can be obtained by reducing the information density. For example, the amount of information recorded per unit area of the optical information medium decreases by decreasing the transfer rate of the recording signal that changes the laser output intensity during information recording and lengthening the signal. The amount of heat supplied to the laser light irradiation position of the medium is sufficient for forming pits, and information is recorded in the information recordable area 1B by laser light of low output intensity using an inexpensive low output laser used for reproducing information. be able to.

Further, it goes without saying that the configurations of the optical disc 1 and the optical information recording / reproducing apparatus 2 in this embodiment are merely examples, and the present invention is not limited to these.

[0045]

As described above, according to the first aspect of the present invention, information can be recorded in the information recordable area by the laser beam of low output intensity using the inexpensive laser used for reproducing information. Therefore, information can be recorded and reproduced by one laser, the structure of the information recording / reproducing apparatus can be simplified and the cost can be reduced, and the write-once optical disc and the information reproducible area and the information recordable area can be realized. It is possible to popularize an optical information medium such as an optical disc having an optical disc and capable of recording information.

Further, according to the second aspect, since the information can be recorded in the information recordable area by the laser having the low output intensity used at the time of reproducing the information, the information can be recorded and reproduced by one inexpensive laser. In addition to simplifying the configuration of the information recording / reproducing apparatus and reducing the cost, it is possible to provide an information recordable optical information medium such as a write-once optical disc and an optical disc having an information read-only area and an information recordable area. It has an extremely excellent effect that it can be popularized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an optical information medium used in an embodiment of the present invention.

FIG. 2 is a configuration diagram showing an optical information recording / reproducing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 1A ... Information reproduction exclusive area, 1B ... Information recordable area, 2 ... Optical information recording / reproducing apparatus, 21 ... Data input / output section, 211 ... Analog input / output interface, 212
... A / D converter, 213 ... D / A converter, 214 ... Digital input / output interface, 215, 216 ... Switch, 22 ...
Recording unit, 221 ... EFM encoder, 222 ... Buffer memory, 223 ... Synchronization circuit, 224 ... Recording correction circuit, 23 ... Reproducing unit, 231 ... Analog waveform shaping circuit, 232 ... Digital signal processing circuit, 24 ... System control unit, 241 System controller, 242 Spindle motor, 243 Optical pickup, 244 Signal processing circuit, 245 Tracking control circuit

Front Page Continuation (72) Inventor Toru Fujii 6-16-20 Ueno Taito-ku, Tokyo Taiyo Denki Co., Ltd.

Claims (2)

[Claims] 1. A disc-shaped optical information in which an information reproduction-only area in which predetermined information is recorded is formed on the inner circumference side and an information recordable area on which information can be recorded at any time is formed on the outer circumference side. In the method of recording information on a medium, at the time of recording information in the information recordable area, while setting the output intensity of the laser used during information reproduction in the information reproduction dedicated area to a predetermined value higher than during information reproduction, A method for recording information on an optical information medium, characterized in that information is recorded by irradiating a laser beam from the laser to the information recordable area at a predetermined linear velocity slower than that at the time of reproducing information in the information reproduction dedicated area. 2. A disc-shaped optical information in which an information reproduction-only area in which predetermined information is recorded is formed on the inner circumference side and an information recordable area on which information can be recorded at any time is formed on the outer circumference side. In the method of recording information on a medium, at the time of recording information in the information recordable area, while setting the output intensity of the laser used during information reproduction in the information reproduction dedicated area to a predetermined value higher than during information reproduction, A method for recording information on an optical information medium, wherein information is recorded by irradiating a laser beam from the laser to the information recordable area at an information density lower than the information density in the information reproduction only area.