JP2002288842A - Optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk, in which both of digital animation data having a large amount of information, and audio or character and computer data which require fine division of sectors are recorded, and which can easily perform retrieval thereof. SOLUTION: Both of the digital animation data having the large amount of information, and the audio or character and computer data having a small information unit are recorded. Pits shifted to the front and the rear with respect to a track direction are provided at the head portion of an information sector including pre-formatted addresses information. The information sector consists of a large information unit consisting of a pre-formatted address unit and a small information unit consisting of a plurality of sub-sectors in which a region for recording/reproducing data is divided into a plurality of sub-addresses. Data for retrieving the digital animation data are disposed in the sub-sector at the head portion of the animation data to be recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk and a method for high-density recording and reproduction of the optical disk.

[0002]

2. Description of the Related Art FIG. 9 is a diagram showing the principle of a conventional high-density reproducing method disclosed in, for example, Japanese Patent Application Laid-Open No. 5-12673. In the figure, 1 is a laser beam for performing recording and reproduction, 2 is an objective lens for condensing the laser beam 1, 3 is a temperature-dependent transmittance variable medium for varying the reflectance or transmittance of the medium, Reference numeral 4 denotes an optical recording / reproducing layer for recording / reproducing information.

FIG. 10 is a diagram showing the medium transmittance of the temperature-dependent variable transmittance medium (hereinafter, referred to as “medium”) 3 in FIG. 9 with respect to the medium temperature. FIG. 11 is a diagram showing the medium 3 in FIG. 9 and FIG. FIG. 4 is a diagram showing a principle of high-density reproduction using the technique. In the figure, 5 is the moving direction of the optical disk 10, 6 is an information detection area which is a light spot irradiation area of the laser light 1, 7 is a recording mark written on the optical recording / reproducing layer 4, and 8 is a medium by light spot irradiation. The high-temperature region 3 and 9 are portions that contribute to actual signal reproduction where the high-temperature region 8 where the light transmittance of the medium 3 is high and the information detection region 6 overlap.

FIG. 12 is a diagram showing the principle of forming a recording mark smaller than the information detection area 6. In the figure, 1
0 indicates an optical disk, 11 indicates a high-temperature region by light spot irradiation, 12 indicates a temperature at which a phase change occurs when the medium 3 is a phase change medium, and 13 indicates a temperature distribution of a portion irradiated with the light spot.

FIG. 13 is a diagram showing the principle of high-density reproduction when a magneto-optical medium is used. In the drawing, reference numeral 14 denotes a reproducing layer initialized by a large external magnetic field and magnetically transferred in a high temperature region, and 15 denotes a recording layer on which information is recorded. FIG.
9 compares the reproduction signal level of the optical disk using the high-density recording method based on the super-resolution principle shown in FIGS. 9 to 13 with the reproduction signal level of the optical disk using the normal recording method.

FIG. 15 is a block diagram of an optical disk apparatus using a conventional high-density recording / reproducing method. In the figure, 1
6 is a disk motor for rotating the disk 10,
17 is an actuator for driving the objective lens 2,
Reference numeral 18 denotes an optical head for emitting a laser beam 1 to reproduce a signal, 19 denotes a signal from a photodetector of the optical head 18, 2
0 is a small signal amplifier circuit for amplifying a small signal from the photodetector, 21 is a waveform equalization / demodulation circuit for reproducing data from a reproduction signal from the small signal amplifier circuit 20, 22
Is reproduction data, 23 is a tracking control circuit for controlling the objective lens 2 to always position the light spot at the track center, and 24 is a focus for controlling the objective lens 2 to always focus the light spot on the disk surface. A control circuit, 25 is a system control circuit for controlling the entire optical disk drive, 26 is an actuator drive signal for driving the actuator 17 based on the outputs of the control circuits 23 and 24, and 27 is a laser power emitted from the optical head 18. Is a recording / reproducing spot diameter adjusting circuit for controlling the recording / reproducing light spot diameter by changing the target value of the auto laser power control circuit 27.

FIG. 16 is a block diagram showing details of a laser power control unit in the optical disk device of FIG.
In the figure, 29 is a deflecting prism for dispersing a laser, 30 is a laser, 31 is a photodetector for receiving reflected light from the optical disk 10 and performing photoelectric conversion, and 32 is a part of the emitted laser light. This is a photodetector for receiving the split light and performing photo-electric conversion. 33 and 34 are IV for converting the output currents of the photodetectors 31 and 32 into voltages.
Conversion circuits, 35 and 36 are integrators for forming a control loop, 37 is a subtractor for comparing with a reference reflected light amount 38, 39 is a phase compensation circuit for forming a control loop,
40 is a subtraction circuit for connecting the auto laser power control loop and the light spot diameter adjustment loop, 41
Is an amplifier for compensating the loop gain, and 42 is a laser driver for driving the laser 30.

FIG. 17 is a block diagram for controlling the diameter of the recording / reproducing light spot so that the amplitude of the reproduced signal is maximized. In the figure, reference numeral 43 denotes a reproduction signal amplitude detection circuit; 44, an A / D converter for taking in amplitude detection information from the reproduction signal detection circuit 43 into a microcomputer 46;
Reference numeral 5 denotes a D for converting a command value from the microcomputer 46 to an analog voltage to indicate an optimum spot diameter.
/ A converter.

Next, the operation of the conventional example will be described with reference to the drawings. An optical disk device generally has a smaller layer storage capacity than a magnetic tape device or the like, and is not particularly suitable for recording a signal such as a digital moving image.
However, a technique for compressing and recording video information such as JPEG, MPEG, and H261, instead of recording the digital moving image signal as it is, is being developed, and it is becoming possible for an optical disc apparatus to sufficiently record.

However, current optical disk devices (CDs and O
In DD), the total storage capacity per disk is still small, and there is a problem in recording digital moving image information for a long time even by using a compression technique. For this reason, a method using a short wavelength laser has been considered, but it is currently difficult to realize a green laser or a blue laser capable of increasing the density with a semiconductor. Technology was desired.

9 to 17 described as a conventional high-density recording / reproducing method show a basic method for achieving high density without relying on this short-wavelength laser. FIG. 10 shows the basic principle. As shown in FIG. 9, at the time of reproduction, a laser beam 1 is irradiated and focused on the medium surface of the optical disk 10 by the objective lens 2. As shown in FIG. 11, the structure of the medium surface of the optical disk 10 includes a medium 3 and an optical recording / reproducing layer 4. The medium 3 has a medium transmittance as the medium temperature increases as shown in FIG. Has the property of changing.

The medium 3 is, for example, a generally well-known phase change medium. Here, needless to say, even if the transmittance is replaced with the reflectance, it is completely equivalent. The recording of the phase change method is performed by irradiating a high-power light spot for a short time to rapidly heat and quench to a temperature higher than the melting point, thereby forming an amorphous phase which is fixed while the atomic arrangement is disturbed. It is carried out by gradually heating and gradually cooling to a temperature higher than the crystallization temperature to return the atomic arrangement to a regular crystalline state. In this case, recording / erasing is performed by a change in the amount of emitted laser light, and reproduction is a method of capturing a change in the amount of reflected light.

If the optical disk 10 is rotating, a physical phenomenon as shown in FIG. 11 occurs. FIG.
9 shows the principle of high-density reproduction using the medium of FIGS. 9 and 10. When the optical disk 10 continues to move in the direction of movement 5 as shown in FIG.
Shift occurs in the high temperature region 8. At this time, the portion from which the optical head 18 reads data is the portion of the information detection region 6, but in the region where the temperature of the medium 3 is low, the light transmittance or the light reflectance is low, so that it actually contributes to signal reproduction. The portion becomes a portion 9 that contributes to actual signal reproduction where the high-temperature region 8 having a high medium transmittance and the information detection region 6 overlap.

For this reason, even a small recording mark 7 that cannot be reproduced from the reproduction light spot due to the limitation of its spatial resolution can be reproduced. Such a method is called a super-resolution phenomenon, and the above description shows a method using a temperature-dependent variable reflectance / transmittance medium. FIG. 13 shows an example of this for a magneto-optical disk, which utilizes the fact that the high-temperature region 8 in which the temperature of the reproducing layer 4 is also high and the reproducing light spot are shifted when the medium moves. In the super-resolution phenomenon of this magneto-optical disk, the reproducing layer 14 is erased in advance by an initializing magnetic field, and the perpendicular magnetization information of the recording layer 15 is transferred in the high-temperature region 8 of the reproducing layer 14, as shown in FIG. Similarly, data is reproduced in a portion 9 that contributes to actual signal reproduction where the high-temperature region 8 and the information detection region 6 where the transmittance of the reproduction layer 14 is high overlap. In such a method using the super-resolution phenomenon, as shown in FIG. 14, even if the recording density is higher than that of a normal disk,
There is no limitation due to spatial resolution.

With the above-described method, the super-resolution phenomenon can be realized even when magneto-optical recording or phase change recording is used. Is a method of reproducing actual data in a portion 9 contributing to actual signal reproduction where the high-temperature region 8 and the information detection region 6 where the temperature is high overlaps. The distribution of the high-temperature region 8 also changes due to changes in the linear velocity in addition to fluctuations in the temperature, the device temperature, and the laser power. Also, at the time of recording,
As shown in FIG. 12, the high-temperature area 11 where the recording of the medium is performed is
Since the spot is formed to be sufficiently smaller than the diameter of the light spot, it becomes impossible to record and reproduce minute pits even with a slight change in the medium temperature.

Therefore, in the conventional high-density reproducing method, the small signal amplifier circuit 2 for amplifying the signal 19 from the photodetector of the optical head 18 in the block diagram of FIG.
An auto laser power control circuit 27 for controlling the laser power emitted from the optical head 18 using the signal amplified by 0, and a variable target value of the auto laser power control circuit 27 for recording / reproducing. By providing a recording / reproducing spot diameter adjusting circuit 28 for controlling the light spot diameter, the size of the portion 9 corresponding to the actual light spot diameter and contributing to actual signal reproduction is adjusted.

As a specific method of adjusting the light spot diameter shown in FIG. 15, there is a method of first detecting the medium reflectance or transmittance and controlling it in real time. FIG. 16 is a block diagram showing details of a laser power control portion in the block diagram of FIG. 15, and based on an output of a photodetector 31 for receiving reflected light from the optical disk 10 and performing photoelectric conversion, the reference value is used as a reference. The amount of reflected light is compared with that of the comparator 37 and used as a reference for a general auto laser power control loop. In general auto laser power control, it is only necessary to control the output power of the laser 30 based on the output of a photodetector 32 for receiving light obtained by dispersing a part of the output laser light and performing photoelectric conversion. On the other hand, in this method, a correction loop for keeping the medium reflectance constant is added.

As shown in FIG. 17, there is also a method of controlling the diameter of the recording / reproducing light spot so that the amplitude of the reproduced signal from the portion 9 which contributes to the actual signal reproduction is maximized. In this method, the amplitude detection information from the reproduction signal amplitude detection
Microcomputer 46 via a / D converter 44
The microcomputer 46 controls hill climbing. As a result of the hill-climbing control, the optimum spot diameter is instructed by the D / A converter 45, and the reference value of the automatic laser power control loop is corrected and controlled.

As described above, by correcting the reference (reference value) of a general auto laser power control circuit so that the amplitude of the reproduced signal becomes maximum or the medium reflectance becomes a predetermined value, The size of the portion 9 that contributes to actual signal reproduction can be adjusted.

[0020]

In the conventional laser power control method as described above, in order to reproduce minute pits, a reliable super-resolution phenomenon occurs, and the apparent light spot diameter is always kept constant. In order to ensure that the recording pit having the shortest pit length can be reproduced, there are the following problems.

In the method of controlling the laser power so that the reproduction signal amplitude is maximized, the optimum laser power value changes whenever the pit length of the recording signal changes. Power does not match. For example, when the pit length of the signal is so large that the super-resolution phenomenon is not required, there is a problem that the greater the laser power, the greater the amplitude of the reproduced signal.

In addition, there is another problem that it is not possible to distinguish which state of the reflectance is the state in which the optimum super-resolution occurs only by keeping the reflectance constant.

Also, in an optical disk apparatus for recording, it is necessary to keep the linear velocity of the optical disk constant, and it is necessary to take out a rotation reference signal for that purpose from the disk. However, there is a problem that the rotation reference signal cannot be obtained.

The present invention has been made in order to solve the above-described problems, and it is to produce a reliable super-resolution phenomenon, always keep the apparent light spot diameter constant, and to reduce the recording pit having the shortest pit length. Digital video data with a large amount of information and audio, text, and computers that need to be finely divided into sectors, as well as ensuring reliable playback and facilitating tracking during recording and data retrieval during playback. It is an object of the present invention to obtain an optical disk that records both data and can be easily searched.

[0025]

An optical disk according to the present invention has a first medium layer which undergoes a phase change by irradiating a light spot of a laser beam formed on a disk substrate, and an optical disk of the first medium layer. In an optical disk on which a second medium layer whose reflectance or transmittance changes due to temperature change is formed on the irradiation side, a pit row having irregularities sufficiently smaller than the light spot diameter preformatted on the disk substrate in advance is used. Equipped with a configured super-resolution laser power control reference pit row, records both digital video data with a large amount of information and voice, text and computer data with a small information unit, and includes preformatted address information At the beginning of the information sector, a pit that is shifted back and forth in the track direction is provided. A large information units comprised of formatted address unit, in which is composed of a small information unit comprising a plurality of sub-sectors divided area for recording and reproducing the data into a plurality of sub-address. According to the above configuration, by adjusting the laser power so that the reproduction signal is maximized in the pre-formatted super-resolution laser power control reference pit row, substantial reproduction in the super-resolution phenomenon is achieved. The spot diameter can always be adjusted to the shortest recording pit length. In addition, digital moving image data having a large amount of information and both voices, characters and computer data which need to be finely divided into sectors can be recorded and easily searched.

Further, the data for retrieving the digital moving picture data is arranged in a sub-sector at the head of the moving picture data to be recorded. According to the above configuration, in an optical disc that records both digital moving image data having a large information amount and audio, text, and computer data having a small information unit, digital moving image data having a large information amount is embedded in another digital moving image data. Can edit.

Digital moving picture data having a large amount of information is recorded in units of the preformatted sector, and voice, character and computer data having a small amount of information are recorded in units of the subsector. According to the above configuration, it is possible to record digital moving image data having a large amount of information and both voice and character and computer data which need to be finely divided into sectors, and to easily search them.

The present invention also relates to a first medium layer which undergoes a phase change due to irradiation of a light spot of a laser beam formed on a disk substrate, and a reflectance or a reflectance on the light irradiation side of the first medium layer due to a temperature change. In an optical disk on which a second medium layer having a variable transmittance is formed, a super-resolution laser power control composed of a pit array of irregularities sufficiently smaller than the light spot diameter preformatted on the disk substrate in advance. Provided is an optical disk having a reference pit row for use. According to the above configuration, by adjusting the laser power so that the reproduction signal is maximized in the pre-formatted super-resolution laser power control reference pit row, substantial reproduction in the super-resolution phenomenon is achieved. The spot diameter can always be adjusted to the shortest recording pit length.

The reference pit row for super-resolution laser power control is arranged at the head of each sector. According to the above configuration, the laser power can be adjusted for each sector.

Further, in the pre-formatted area of the optical disk, there is provided a tracking wall pit row which is shifted back and forth in the track direction which can be detected with a normal light spot diameter. According to the above configuration, when the light spot passes through the wobble pit row, the level of the reproduction signal of each pit is held, and a difference between the light spot position and the position of the track center is detected by taking a difference, and the offset is detected. No tracking is possible.

Further, an area in which the reflectivity of the disk can be measured is provided in the preformatted area of the optical disk. According to the configuration, by adjusting the laser power so that the disk reflectivity of the area where the reflectivity can be measured is constant, the substantial reproduction spot diameter at the time of super-resolution phenomenon is always minimized. It can be adjusted to the recording pit length.

Further, a code for indicating the type of the optical disk is provided between a portion of the optical disk which is clamped to the motor and a portion where the first and second medium layers are formed. According to the above configuration, when reproducing the optical disk, the type of the optical disk can be detected by reading the code, so that the laser power required for reproducing the optical disk can be adjusted.

The present invention also relates to a first medium layer which undergoes a phase change by irradiation of a light spot of a laser beam formed on a disk substrate, and a reflectivity or a change in temperature on a light irradiation side of the first medium layer due to a temperature change. A second medium layer having a variable transmittance is formed, and a super-resolution laser power control reference comprising a pit array of irregularities sufficiently smaller than the light spot diameter pre-formatted on the disk substrate in advance. Provided is a method of reproducing an optical disk having a means for controlling laser power so that the amplitude of a reproduction signal of a reference pit sequence for super-resolution laser power control becomes maximum when reproducing an optical disk having a pit sequence. According to the above configuration, the laser power can be optimally controlled in the preformatted super-resolution laser power control reference pit row region.

The present invention also relates to a first medium layer which undergoes a phase change due to irradiation of a light spot of a laser beam formed on a disk substrate, and a reflectance or a reflectivity or a temperature change on the light irradiation side of the first medium layer. A second medium layer having a variable transmittance is formed, and a super-resolution laser power control reference comprising a pit array of irregularities sufficiently smaller than the light spot diameter pre-formatted on the disk substrate in advance. When reproducing an optical disk having a pit array, a timing signal is generated by a PLL circuit from a reproduction signal in a pit area that can be detected at a normal light spot diameter, and the detection timing of the super-resolution laser power control reference pit array is determined. There is provided a method for reproducing an optical disc provided with a means for obtaining. According to the above method, it is possible to obtain the detection timing of the super-resolution laser power control reference pit row from the reproduction signal of the pit area that can be detected with a normal light spot diameter.

The present invention also relates to a first medium layer which undergoes a phase change due to irradiation of a light spot of a laser beam formed on a disk substrate, and a reflectivity or a change in temperature on a light irradiation side of the first medium layer due to a temperature change. A second medium layer having a variable transmittance is formed, and a super-resolution laser power control reference comprising a pit array of irregularities sufficiently smaller than the light spot diameter pre-formatted on the disk substrate in advance. When reproducing an optical disc having an array of pits, where the reflectivity can be measured during reproduction of an optical disc having an area where the reflectivity of the optical disc can be measured within the preformatted area of the optical disc. By changing the reproduction laser power between the crystal part and the amorphous part, the average value of the optimum laser power in each region is calculated, and this average value is used as the optimum laser power. To provide an optical disc playback method characterized by comprising means for maintaining the over value. According to the above method, it is possible to optimally control the laser power in an optical disc having an area where the reflectance can be measured.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram of an optical disk apparatus using the optical disk high-density recording / reproducing method according to Embodiment 1 of the present invention. In the figure,
Reference numeral 47 denotes a comparator and an amplifier circuit for discriminating binarized data from the reproduced signal, and 48 denotes an optical disk 1 from the binarized data.
A pattern matching circuit for distinguishing between a wobble pit preformatted to 0 and a reference pit string for super-resolution laser control; 49, a PLL circuit for generating a reference clock based on the output of the pattern matching circuit 48; Is a timing generation circuit for generating a timing signal of each preformat signal and recording signal based on the output of the PLL circuit 49;
A hold circuit for detecting a track deviation amount from a wobble signal preformatted in the optical disk 10
This is a laser power control unit that detects and controls the optimum laser power from the super-resolution laser control reference pit row that has been preformatted.

Numeral 53 denotes a data detecting circuit for detecting reproduced data from the binarized data, and numeral 54 denotes a portion between a portion clamped by the disk motor 16 on the inner circumference of the optical disk 10 and a recording portion on which the medium 3 is formed. From the printed code,
A disc type discriminating circuit for discriminating whether the disc is a high-density disc using a medium of the super-resolution phenomenon or a read-only disc formed only of concave and convex pits;
Is a phase control circuit that controls the rotation phase of the disk motor 16 based on the output of the disk motor 16, and 56 is a motor driver that drives the disk motor 16.

FIG. 2 is a diagram for explaining a control operation in the laser power control unit 52 of the optical disk device shown in FIG. In the figure, reference numerals 57 to 60 denote signal pit trains preformatted on the optical disk 10, 59 denotes a pit train forming a laser power setting area, 57 denotes a wobble pit train for tracking, and 58 denotes a wobble position judgment in combination with the wobble pit train 57. A pit 60 for forming a pattern for use is a sector pattern representing a sector address. Reference numeral 61 denotes a reproduction laser power level; 62, a reproduction signal at this time; 63, a binarized reproduction signal; and 64, a PLL reference clock created from the binarized reproduction signal 63.

Next, the operation will be described. The data in the preformatted portion is reproduced by a comparator and amplifier circuit 47 for discriminating the binarized data shown in FIG. 1, and wobble pits and laser power settings preformatted on the optical disk 10 based on the binarized reproduction signal 63 are reproduced. Region 59
A PLL reference clock 64 is generated by a PLL circuit 49 according to a pattern determined by a pattern matching circuit 48 for distinguishing a determination pattern for determining. Further, P
Based on the output of the LL circuit 49, a timing signal for each preformat signal and recording signal is generated. As described above, the timing signals of the super-resolution reference pattern and the tracking wobble pattern can be obtained.

Next, the laser power controller 52 controls the laser power based on the subroutine of the software control shown in FIG. 4 using the timing signal. When the super-resolution power selection timing is input from the timing generation circuit 50, the level of the reproduction signal 62 is latched at the PLL clock timing, and the process of increasing the laser power by Δt is performed until all the power determination areas are latched. The level of the laser power at which the level of the reproduction signal 62 becomes maximum is repeatedly selected, and this level is maintained until the next super-resolution power selection timing. With this control, it is possible to set the optimum laser power at the time of super-resolution in the laser power setting area 59 that has been preformatted in advance. Since the laser power setting area 59 is arranged for each sector, it is possible to cope with a difference between the inner and outer circumferences of the optical disc 10 and a variation in linear velocity and the like. Further, since the laser power setting area 59 has a pattern fixed to the shortest pit length, it is possible to accurately extract the laser power at the time of reproduction.

Embodiment 2 FIG. 3 shows a laser power control unit 52 of the optical disk apparatus shown in FIG.
Is a diagram for explaining the control operation in the above, and shows the operation principle of measuring the reflectance of the medium 3 and setting the laser power at the time of super-resolution. In the figure, reference numeral 59 'denotes a laser power setting area for measuring a reflectance, 59a denotes an amorphous area of the phase change medium 3 in the laser power setting area 59',
9b represents a crystal region. 61 'is the reproduction laser power,
62 'is a reproduction signal.

Next, the operation will be described. FIG. 3 shows the operation of a method of measuring the reflectance from the optical disk 10 and setting the optimum laser power at the time of super-resolution in the preformat portion other than the portion for recording and reproducing data. The configuration can be realized by a block configuration similar to that of FIG. However, in this case, the optical disk 1
The laser power setting area 59 is not the super-resolution reference pattern provided in the pre-format section of FIG. 2 as in the laser power setting area 59 in FIG. 2 but is not preformatted as shown in FIG. 'Is provided.

In the case of a phase change medium, a crystal area 59b and an amorphous area 59a are previously written in a laser power setting area 59 'for measuring the reflectance as shown in FIG. The reproduction laser power 61 'is changed as shown in FIG. At this time, the reproduction signal 6 equivalent to the medium reflectance in the laser power setting area 59 '
The level of 2 ′ is as shown in FIG. 3D, but the intermediate value E between the minimum value A and the maximum value B of the reflectance in the amorphous region 59a (intermediate value E = (I + B) / 2 ) Is calculated, and the reproduction laser power (g) at this time is stored.

Similarly, also in the crystal region 59b, the reproducing laser power 61 'is changed, and the intermediate level (f) between the minimum value (c) and the maximum value (d) of the binarized reproduction signal 62' is calculated. The reproduction laser power (h) at this time is stored. Next, the average value (i) of the calculated reproduction laser power values (g) and (h) is held after the laser power setting area 59 ′. As described above, by providing the dedicated area for measuring the medium reflectance, it is possible to set the laser power at the time of accurate super-resolution.

Embodiment 3 FIG. 6 is a diagram showing a preformat unit of the optical disc according to Embodiment 3 of the present invention. In the super-resolution method, as shown in FIG. 11, the portion 9 contributing to actual signal reproduction is an area where the circular information detection area 6 and the high-temperature area 8 of the medium 3 overlap. The portion 9 contributing to actual signal reproduction has a shorter line direction than the information detection region 6 of the light spot.

For this reason, the optical disc 1 for performing super-resolution reproduction
By making the pit shape of the pit row portion having irregularities sufficiently smaller than the above-mentioned light spot diameter pre-formatted to 0 into a short pit shape in the line direction and a long pit shape in the track direction, the pit shape in the super-resolution phenomenon is substantially reduced. By forming the light spot in the same shape as the typical light spot, a larger reproduced signal amplitude can be obtained.

Embodiment 4 FIGS. 5A and 5B are views for explaining the optical disc of the fourth embodiment. FIG. 5A shows a preformat portion of the optical disc 10, FIG. 5B shows a plan view of the optical disc, and FIG. Is shown. FIG.
Reference numeral 65 in (a) denotes a wobble pit for detecting a tracking error signal and a determination pattern portion for determining the position of the wobble pit.

In the wobble pit portion 65, the pits having substantially the same light spot diameter as those in the uneven pit row portion preformatted on the preformatted disk substrate are shifted back and forth in the track direction with respect to the center of the track. When a light spot passes through the two wobble pits by the hold circuit 51, a predetermined pattern including the wobble pits is determined by the pattern matching circuit 48 of FIG. By detecting and holding the amplitude of the pit reproduction signal and taking the difference, the position of the light spot of the reproduction laser light and the deviation from the track center are detected so that tracking without offset can be performed. I have.

In order to obtain a tracking signal by this wobble pattern, at least two tracks per disk rotation are required.
Unless 000 or more patterns are provided, it is needless to say that a tracking error signal causes a phase rotation due to sampling, making it impossible to follow the track. Generally, in an optical disk device using the push-pull tracking method, an offset signal is mixed into a sensor signal as the objective lens moves. But,
In the sample servo method using the wobble pit, an error signal is detected in a time-division manner and a difference between the error signals is detected. Therefore, an offset signal accompanying the movement of the objective lens is canceled out, and an error signal without an offset can be obtained. .

The wobble pit for servo detection needs to obtain error information irrespective of the super-resolution phenomenon in order to prevent the servo from deviating (reflection rate at the time of super-resolution).
It is needless to say that the pit diameter should be set to a value that can be detected with a normal light spot diameter (without using super-resolution), since the influence of transmittance change must not be exerted).

By arranging the wobble pits at a constant interval in the line direction, this is used as the rotation reference information of the optical disk during reproduction, and the linear velocity constant control (CLV) operation is performed by the phase control circuit 55 of FIG. It becomes possible. Conventionally, as a method of controlling a constant linear velocity rotation at the time of recording using a recordable optical disk, there is known a method of meandering a track guide groove and using a modulation component of a reproduced signal due to the meandering as a rotation detection signal. However, in the optical disk in which the wobble pits are preformatted according to the fourth embodiment, the pits themselves for tracking error detection become the rotation detection signals.

Embodiment 5 FIG. Embodiment 5 will be described with reference to FIG. FIG. 5A shows a preformat portion of the optical disk. Reference numeral 66 denotes a portion in which a reference pattern signal for super-resolution and address information of a sector are recorded.
Reference numeral 7 denotes an area for recording actual data.

The address information of the sector is recorded in a pit row having substantially the same diameter as the light spot diameter, except for the pit row portion having irregularities sufficiently smaller than the light spot diameter pre-formatted on the optical disk 10 in advance. Is formed for each field of the digital moving image recorded on the optical disc 10 or for each frame, thereby making it possible to easily search for each image for each screen.

Embodiment 6 FIG. FIG. 5B is a plan view of the optical disk, and FIG. 5C shows a binarized reproduction signal.
In the figure, 68 is a sector which is one unit of information recording,
Reference numeral 69 denotes a print code for determining the type of the disc.

The data detection circuit 53 shown in FIG. 1 detects data from the binarized reproduction signal. At this time, the data discrimination level differs as shown in FIG. 5C depending on the type of the optical disc. To detect the type of this optical disk,
A code 69 indicating the type of the optical disk is printed on an annular portion between the clamp portion of the optical disk on the inner periphery of the motor and the portion where the recording medium is formed, and the code 69 is read. Disc type determination circuit 54
Then, it is determined whether the disc is a high-density disc using a medium of the super-resolution phenomenon or a read-only disc formed only with uneven pits,
The above is addressed by switching the threshold level of the data detection and the amplification factor of the reproduced signal.

It is needless to say that a command value of the number of revolutions, a data capacity and the like can be written in the code 69. These codes are performed by irradiating LED light and reading the reflected light with a photodiode or the like, as shown in FIG. 5B.

Embodiment 7 FIG. FIG. 7 is a diagram showing a sector structure of information on a high-density optical disk according to the seventh embodiment. In FIG. 7, (a) is a preformat portion showing the head of a sector, 70 is a laser power setting area for super-resolution, 71 is a wobble pit area for tracking error detection, 72 is an address area, and 73 is a data recording area. It is. FIG. 7B shows a wobble mark portion in a sector.
It shows the sequence up to. FIG. 7C shows a large information area in which some of the sectors 74 are further gathered. Reference numeral 75 denotes a pit row of a preformat portion at the head thereof, and reference numeral 76 denotes a sector arrangement of the large information area. Things. 8 (a), 8 (b),
FIG. 7C shows a variation of the data array of the large information area in FIG.

Next, the operation will be described. A sector of information in a portion where information of the digital moving image is recorded is configured in image field or frame units,
At the beginning of the frame, there is an address area 72 formed by concave and convex pits having substantially the same size as the reproduction light spot diameter on the disk substrate, and in a part where program data and control data other than image data are recorded. , The sub address 75-E is recorded by phase change or write once.

For example, digital moving image data (G) 1 to (G) n are recorded, and search data for inserting or editing this moving image into another still image or the like is used as search data for the moving image data. If you want to record at the beginning,
The sector arrangement is configured as shown in FIG. When the amount of text information, voice, and computer program information is larger than the still image data, the configuration is as shown in FIG. When moving image data and computer programs are mixed, the configuration is as shown in FIG.

In this case, although the digital video data has a large amount of information, it is not necessary to set address information in detail. If one piece of address information is provided for one screen, detailed address information is not required except in special cases such as dividing and editing the inside of the screen. Also, in the moving image compression algorithm such as the MPEG method or H261, the data rate in each image unit is constant.
Therefore, it is desirable to record and reproduce the image data in units of sectors pre-formatted on the disk in advance. However, since the information amount of computer data and voice / character data is not constant, it is necessary to set detailed sectors. Therefore, as in the seventh embodiment, a method of recording the address of the program data by the phase change is desired. In this case, it is considered that it is desirable to write data before and after the tracking wobble pits that are present in 2000 or more per disk circumference.

By forming sub-sectors by further subdividing the preformatted sector, not only video information but also general computer program data can be easily searched.

[0062]

As described above, the optical disc according to the present invention is a super-resolution laser power control composed of a pit array of irregularities smaller than the light spot diameter pre-formatted on the optical disc substrate in advance. Equipped with a reference pit string, it records both digital video data with a large amount of information and audio, text and computer data with a small information unit, and has a track at the beginning of an information sector containing preformatted address information. In addition to providing pits shifted in the front and rear directions, the information sector is composed of a large information unit composed of pre-formatted address units and a plurality of sub-sectors in which an area for recording and reproducing the data is divided into a plurality of sub-addresses. Since it is composed of small information units,
By adjusting the laser power so that the reproduced signal is maximized in the part of the reference pit row for super-resolution laser power control, the actual reproduction spot diameter during super-resolution phenomenon is always adjusted to the shortest recording pit length In addition, digital moving image data having a large amount of information and both voice and character data and computer data which need to be divided into sectors can be recorded and easily searched.

Further, if the data for retrieving the digital moving image data is arranged in the sub-sector at the head of the moving image data to be recorded, the digital moving image data having a large information amount and the audio data having a small information unit are arranged. In an optical disc that records both data and characters and computer data, it is possible to edit digital video data with a large amount of information to fit into other digital video data.

Further, the digital moving picture data having a large amount of information is recorded in units of the preformatted sectors, and the voice, characters and computer data having a small amount of information are recorded in units of the subsectors. Both large amounts of digital moving image data and voice and text and computer data that need to be finely divided into sectors can be recorded and easily searched.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disc apparatus using a high-density recording / reproducing method for an optical disc according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining a control operation in a laser power control unit according to the first embodiment.

FIG. 3 is a diagram for explaining a control operation in a laser power control unit according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a software control subroutine in a laser power control unit according to the first embodiment.

5A and 5B are diagrams for explaining the optical disc according to the present invention, wherein FIG. 5A shows a preformat unit, FIG. 5B shows a plan view of the optical disc, and FIG. 5C shows a binarized reproduction signal.

FIG. 6 is a diagram showing a preformat unit of the optical disc according to the present invention.

FIG. 7 is a diagram showing a sector structure of information on a high-density optical disk according to the present invention.

FIG. 8 is a diagram showing a sector structure of information on a high-density optical disk according to the present invention.

FIG. 9 is a principle diagram of a conventional high-density reproduction method.

10 is a diagram showing the medium transmittance of the temperature-dependent transmittance variable medium in FIG. 9 with respect to the medium temperature.

FIG. 11 is a diagram showing a principle of high-density reproduction using the medium of FIGS. 9 and 10;

FIG. 12 is a diagram showing the principle of forming a recording mark smaller than a light spot.

FIG. 13 is a diagram showing the principle of high-density reproduction when a magneto-optical medium is used.

FIG. 14 is a diagram comparing a reproduction signal level when a high-density recording method based on the super-resolution principle shown in FIGS. 9 to 13 is used with a reproduction signal level of a normal optical disk.

FIG. 15 is a block diagram of an optical disk device using a conventional high-density recording / reproducing method.

FIG. 16 is a block diagram showing details of a laser power control part in the block diagram of FIG. 15;

FIG. 17 is a block diagram for controlling the diameter of the recording / reproducing light spot so that the reproduction signal amplitude is maximized.

[Explanation of symbols]

1 laser light, 2 objective lens, 3 temperature-dependent transmittance variable medium, 4 optical recording / reproducing layer, 5 moving direction of disc, 6 information detection area, 7 recording mark,
8 High-temperature area of medium, 9 Part contributing to actual signal reproduction, 10 Optical disk, 11 High-temperature area due to light spot irradiation, 12 Temperature causing phase change, 13
Temperature distribution, 14 reproduction layer, 15 recording layer, 16
Disk motor, 17 actuator, 18 optical head, 19 signal from photodetector, 20 small signal amplification circuit, 21 waveform equalization / demodulation circuit, 22 reproduction data, 23 tracking control circuit, 24 focus control circuit, 25 system control circuit,
26 Actuator drive signal, 27 Auto laser power control circuit, 28 Recording / playback spot diameter adjustment circuit, 29 Deflection prism, 30 Laser, 3
1,32 photo detector, 33,34 IV conversion circuit,
35, 36 integrator, 37 comparator, 39 phase compensation circuit, 40 subtraction circuit, 41 amplifier, 42
Laser driver, 43 playback signal amplitude detection circuit,
44 A / D converter, 45 D / A converter, 46 microcomputer, 47 comparator and amplifier circuit, 48 pattern matching circuit,
49 PLL circuit, 50 timing generation circuit, 5
1 hold circuit, 52 laser power control unit,
53 data detection circuit, 54 disk type discrimination circuit, 55 phase control circuit, 56 motor driver,
57 Wobble pit row for tracking, 58 Pits forming a pattern for wobble position determination, 5
9, 59 'laser power setting area, 59a amorphous area, 59b crystal area, 60 sector pattern, 61, 61' reproduction laser power, 62, 6
2 'playback signal, 632-valued playback signal, 64
A PLL reference clock, 65 a wobble pit for detecting a tracking error signal and a portion of a determination pattern for determining the position of the wobble pit, 66
A portion in which a reference pattern signal for super-resolution and address information of a sector are recorded; 67 an area for recording actual data; 68 sectors; 69 a print code;
Laser power setting area, 71 Wobble pit area for tracking error detection, 72 address area, 7
3 Data recording area, 74 Code 70 in one sector
An array of up to 73, a pit row of 75 preformat parts, and an 76 sector array.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 20/12 G11B 20/12 F-term (Reference) 5D029 MA04 5D044 AB07 BC03 BC06 CC06 DE18 DE38 DE55 DE57 FG18 GK12 5D090 AA01 CC04 CC14 FF11 FF41 GG12 GG28 5D118 AA13 BA01 BC13 BF03 CD03 5D119 AA11 BA01 DA05 HA54

Claims (3)

[Claims] 1. A first medium layer which undergoes a phase change due to irradiation of a light spot of a laser beam formed on a disk substrate, and a reflectance or a transmittance on the light irradiation side of the first medium layer due to a temperature change. An optical disc on which a second medium layer having a variable width is formed, a super-resolution laser power control reference comprising a concavo-convex pit array sufficiently smaller than the light spot diameter pre-formatted on the disc substrate. Equipped with a pit row, it records both digital video data with a large amount of information and audio, text, and computer data with a small information unit. And the information sector is composed of preformatted address units. An optical disc comprising: a large information unit; and a small information unit including a plurality of sub-sectors in which an area for recording and reproducing the data is divided into a plurality of sub-addresses. 2. The optical disk according to claim 1, wherein data for searching for the digital moving image data is arranged in a sub-sector at a head portion of the moving image data to be recorded. 3. The digital moving picture data having a large amount of information is recorded in units of the preformatted sector, and the voice, character, and computer data having a small amount of information are recorded in the unit of the subsector. The optical disc according to claim 2.