JP2875342B2 - Optical information recording medium - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information processing apparatus, and more particularly to a large-capacity and high-speed optical disk file apparatus.

[Conventional technology]

Conventionally, as an apparatus of this type, for example, an optical disk medium having a diameter of 300 mm has a user capacity of 1.3 GB on one side and a transfer rate of 4 GB.
40KB / s has been put to practical use. In this apparatus, in order to increase the throughput, the disk is rotated at a constant angular velocity, and as a data recording method, a method in which “1” after modulation, which has been adopted in the conventional optical disk, corresponds to the center of the pit hole. Hereinafter, a pit position recording method is used. In addition, a CAV method for making the recording bit rate constant at the inner and outer circumferences is adopted.

In order to improve the performance of the optical disk, these methods have difficulty.

[Problems to be solved by the invention]

It is an object of the present invention to realize a disk device having a significantly higher speed and a larger capacity than conventional optical disk devices. Specifically, we propose an optical disc device that has a disc of about 300 mm in diameter and a side of 3.0 GB or more and a transfer rate of 1 MB / s or more.

[Means for Solving the Problems] In the present invention, a pit edge recording method in which “1” of modulated data is made to correspond to the edge portion of a long hole pit as a recording method is adopted. The MCAV recording method divides the recording area into zones in units of multiple tracks, changes the recording clock for each zone, and keeps the length of the recording pits substantially constant even when the disk rotates at a constant angular speed. Is used.
The recording / reproducing apparatus of the present invention has means for controlling recording conditions and reproducing conditions, and means for changing the control for each zone. Then, a method of independently detecting the front edge and the rear edge of the recording pit, discriminating data for each edge, and then combining these edge data is used.

[Action]

1. Even if the optical resolution is the same as the pit position recording method, the recording bit density is increased by the pit edge recording method.

FIG. 2 shows a comparative example between a pit position recording method as a conventional recording method and a pit edge recording method used in the present invention.

In the pit position recording, if the pit interval is shortened in order to improve the recording density, the level of a portion where there is no pit is reduced due to interference between the pits in the reproduced waveform 4, and it becomes difficult to disassemble and detect the pit. However, if the data is made to correspond to the ends of the variable-length pits, even if the characteristics of the optical system are the same and the recording density is improved, the reproduced waveform 5
, The pit end can be detected stably.

2. Such a recording form is adopted in a reproduction-only video disk and a digital audio disk in an optical disk. However, these read-only disks have a form in which edges are accurately recorded in advance using a photoresist as a recording film in advance, a stamper is created from a developed master, and a disk is created by stamping based on the stamper. Attempts to apply this method to a recordable / reproducible disc have the following problems. The recording principle of a recordable optical disk is to change the irradiation energy intensity of the spot 3 which has been narrowed down minutely, locally change the temperature distribution on the recording medium, and thereby change the optical characteristics of the recording medium to transfer information. It is to be recorded. From this recording principle, the pit shape changes according to the shape of the light spot, the intensity-modulated light pulse waveform, the recording characteristics of the recording medium (determined by the recording film composition, film thickness, underlayer, substrate), the linear velocity during recording, etc. Receive. For this reason, as a conventional recording method, a pit position method in which information is provided at a position (center position) of a pit rather than having information in a pit shape has to be adopted. In the present invention, means for controlling the recording conditions is provided to control the pit shape, and the factors determining the recording characteristics are controlled. In particular, in the present invention, as described later, the recording area is divided into zones in units of a plurality of tracks, and the recording clock is changed for each zone so that even if the disk rotates at a constant angular velocity, the recording area is changed between the zones. The recording condition control is changed for each zone by using the MCAV recording method in which the length of the recording pit is substantially constant.
As a result, a variable-length pit whose end corresponds to the data can be formed stably.

3. Even if the recording control described in the above item 2 is performed, there are variations in factors that determine recording characteristics between devices and media, or factors that determine reproduction characteristics. Looking at the fluctuation characteristics of these factors, the fluctuation does not change for each individual pit, but is very low when viewed from the modulation frequency, and can be regarded as almost static. Focusing on the edge of the pit, the shape of the pit changes, but the positions of the front edge and the rear edge hardly change. Therefore, in order to reproduce data stably even if there is the above-mentioned variation, the leading edge and the trailing edge are detected independently, the data is discriminated for the leading edge and the trailing edge, and then these edge data are combined and recorded. Demodulate information. As a result, data can be accurately reproduced even if the pit shape changes.

4. As described above, the recording area is divided into zones in units of a plurality of tracks, and the recording clock is changed for each zone so that the length of the recording pit is substantially constant even when the disk rotates at a constant angular speed. When the MCAV recording method is used, the recording capacity gradually increases as the number of zones is increased, as shown in FIG. 3, as compared with the CAV method in which the recording clock is constantly recorded irrespective of the disk radial position. As the capacity approaches 1.5 times the capacity of the system, the capacity can be increased effectively.

5. In order to apply this MCAV recording method to edge recording, in the present invention, recording conditions (recording power, recording pulse width, recording clock frequency, etc.) and reproduction conditions (signal processing circuit characteristics, reproduction clock generation characteristics, etc.) Control for each zone. As a result, the MCAV recording method and the pit edge recording method are compatible, and information can be recorded and reproduced at a high density.

〔Example〕

FIG. 1 is a block diagram of a recording / reproducing apparatus according to one embodiment of the present invention. The driving device is connected to a host (not shown).
This SCS is connected to the CPU and SCSI interface.
The I interface sends data, commands, and the like from the host to the drive, and sends reproduced data and information indicating the operation status of the drive to the host from the drive. This SCSI interface is connected to the SCSI protocol controller 10,
Controls the exchange of signals on the interface. First, the configuration of the controller will be described with reference to FIG. Data input / output to / from the SCSI protocol controller 10 is connected to the ECC circuit 13 and the buffer memory 14 via the pointer controller 11 and the buffer controller 12, and is connected from the ECC circuit 13 to the formatter 15.

Control commands input / output to / from SCSI protocol controller 10
16 is also connected to the pointer controller 11.
SCSI protocol controller 10 and pointer controller
11, pointer controller 11 and buffer controller 12,
Buffer controller 12 and ECC 13, buffer controller
Control instructions 16, 17, 18, 1 for transferring data are provided between blocks 12 and buffer memory 14, ECC 13 and formatter 15.
9,20 are connected respectively. Controller control MPU2
The address information 22 generated from 1 is an address recorder 23
And issues a command CS for chip select of each memory. The address information 22 is input to the RAM 23, the DMA controller 24, the formatter 15, the SCSI controller 10, the pointer controller 11, the buffer controller 12, and the ECC 13, and specifies the address of each data. Control information for controlling data is controlled by the controller.
MPU21, RAM23, DMA controller 24, formatter 15, SCSI
It is exchanged via a common bus between the controller 10, the pointer controller 11, the buffer controller 12, and the ECC 13. In particular, between the controller control MPU 21 and the DMA controller 24, a signal 26 for controlling the release of the common bus is provided.
Are connected. The access control information 25 is input from the controller control MPU 21 to the RMA 23, the DMA controller 24, the formatter 15, the SCSI controller 10, the pointer controller 11, the buffer controller 12, and the ECC 13, and used for data access. In addition, the above address information
22 and access information 25 are input from the buffer controller 12 to the buffer memory 14. Various interrupt control signals 27 are input to the controller control MPU 21. The formatter 15 is connected to a driving device via an ESDI interface 28. The interface 28 exchanges recording / reproducing data, various information for controlling the operation of the driving device, and information indicating the operation status of the driving device.

Returning to FIG. 1, the recording data 30 from the formatter 15
Is converted into a modulation signal 32 by the modulation circuit 31 and input to the write pulse generation circuit 33. Write pulse generation circuit 33
Then, using the control information 34 corresponding to the MCAV zone and the recording clock 36 generated from the frequency synthesizer 35, a modulation pulse is generated by controlling the modulation signal to have a recording pulse width corresponding to each MCAV zone, The recording pulse 37 is sent to the driver 38. The control information 34 corresponding to the MCAV zone is input to the frequency synthesizer 35,
A recording clock 36 corresponding to the AV zone is generated. The control information 34 is input to the write power switching circuit 39, and supplies a recording power set value 40 corresponding to the MCAV zone to the laser driver 38. The laser driver 38 creates a pulse waveform 42 for driving the laser based on the power set value 40, the recording pulse 37, and the APC control signal 41,
The laser which is the light source of the optical head 44 is driven via the high frequency superimposing circuit 43.

The optical head 44 outputs a signal 45 from the detector that has received the light emitted from the laser, and inputs the signal 45 to the APC circuit 46. As a result, the edge recording data modulated corresponding to the MCAV zone can be stably recorded according to the linear velocity without being affected by fluctuations in characteristics of a laser or the like.

The optical head 44 has light spot control information, for example,
Focus control information and tracking control information are input. Defocus signal 47 from optical head 44
Is input to the focus control circuit 48, a control signal 49 for driving the focus actuator is output to the focus actuator, and focus servo for maintaining the focal plane of the light spot on the disk surface is performed. Also, the optical head 44
A tracking servo that outputs a track shift signal 50, outputs a control signal 51 for moving the light spot minutely in the radial direction to the optical head 44, and drives the fine actuator to position the light spot along the track. Perform

The movement of the light spot in a minute area is performed by a fine actuator, and when the light spot is moved over a large area, the optical head is moved using the coarse actuator 52.
Driving 44 whole. The course control information 53 is input to the course actuator 52. Also, at the time of tracking, the fine actuator and the course actuator 52 move in conjunction with each other, so that the light spot follows the track eccentricity.
Thus, the light spot is stably controlled, and data can be recorded and reproduced accurately. In the case of random access, a signal 54 from an external scale attached to the optical head 44 is input to the course control circuit 55, and the course actuator is controlled using the signal 54 from the external scale representing the position of the head. A signal 53 is generated, and the entire head 44 is first moved largely near the target track.
To move the light spot and position it on the target track. In a series of operations of these light spots, information for control is exchanged between the mechanical controller 56 and the focus control circuit 48, the tracking control circuit 69, and the course control circuit 55, and each actuator is controlled by the mechanical controller 56. This is realized by being controlled. Also,
From the mechanical controller 56, control information is exchanged with a circuit 59 for controlling a spindle motor 58 for rotating the disk 57.The spindle motor control circuit 59 sends information 60 indicating the rotation status of the spindle motor 58. The information 61 for controlling the rotation of the spindle motor 58 is sent from the mechanical controller 56. The spindle motor 58 is driven by a spindle motor control circuit 59 and is stably rotated at a constant rotation speed.

The drive control MPU 62 controls the operation of the entire optical disk drive, and includes an auto loading mechanism 6
Signals are exchanged among 3, the mechanical controller 56, the controller control MPU 21, and the panel control unit 64, respectively. The drive control MPU 62 controls the auto-loading mechanism 63, attaches and detaches the disc 57 to and from the spindle, controls the controller control MPU 21 to perform signal processing for recording and reproduction, and controls the mechanical controller 56 to control the light for recording and reproduction. A series of operations of the optical disk drive are controlled to perform spot positioning and control the panel control unit 64 to obtain information for maintenance.

The signal detected by the optical head 44 is received by a photodetector, converted into an electric signal, and then amplified by a preamplifier 65. The signal leaving the preamplifier 65 is a waveform shaping circuit
The pulse 66 is input to the circuit 66, and the circuit 66 outputs pulses 121 and 119 respectively corresponding to the leading edge and the trailing edge of the pit. The leading edge signal 121 and the trailing edge signal 119 are input to the VFOs 600 and 601, respectively, and the reproduced clocks 501 and 5 are respectively inputted.
03 is created, normal data discrimination is performed using these clocks and edge signals, and leading edge data 502 and trailing edge data 504 are detected. These data are input to the reproduction / synthesis circuit 222, and after the edge data is synthesized, the data is input to the demodulation circuit 67 to obtain the reproduction data. Details of the recording / reproducing system will be described later.

The above is the outline of the configuration of the optical disk device according to the present embodiment. Hereinafter, the edge recording characteristics and the recording control method determined from this will be described in more detail for the present embodiment, the reproduction control method for detecting the reproduction data from the recorded pits will be described, and then the specific format for MCAV And the overall signal flow of recording and reproduction will be described.

As the recording medium of the optical disk 57, in this embodiment, the fifth medium
As shown in FIG. 1A, a UV film 71 provided on a glass substrate 70 and a recording film 72 provided thereon is used. Recording film 72
It is preferable to use a Te-based ternary metal film (PbTeSe). The UV film 71 has a guide groove 73 for positioning the light spot. As shown in FIG. 5 (b), two disks 57 are bonded in a sandwich structure. Using this recording medium, at a recording radius position of 70 mm and a rotation speed of 1000 rpm, a spot diameter of 1.3 mm was used.
Performs long hole recording with a light spot of μm and recording pulse width T _W
Expressed by the recording power P to the parameter relating to the rehabilitation pulse width T _R and is as Figure 6. The horizontal axis is the recording pulse width
T _W, the vertical axis represents the reproduction pulse width T _R. Play pulse width T _R is,
The range recording pulse width T _W is large, approximately recording pulse width T _W
Has a linear relationship with an offset amount. When the recording pulse width T _W becomes shorter abruptly shortened deviates from linearity. While the recording power P is large linear relationship reproduction pulse width T _R and the recording pulse width T _W being substantially maintained, the offset amount increases. Looking further this characteristic in more detail, the recording power slope of P linear relationship is large becomes large changes minutely, and reproduction pulse width T _R shift towards linearity deviation begin recording pulse width T _W is long Will come. Even if the recording radius position is doubled to 140 mm at the same rotation speed (1000 rpm) at the same rotation speed, the tendency does not change as shown in FIG.

The pit edge recording system which correspond to the data to the edge of the elongated hole pit, it is preferable that the recording pulse width T _W is equal to the reproduction pulse width T _R. However, if the slow linear velocity is set to the recording power P so as to equalize the recording pulse width T _W and the reproduction pulse width T _R, the fluctuation of the reproduction pulse width T _R becomes larger. This is shown in FIG. In this figure,
The relationship between the recording power P and the fluctuation of the reproduction pulse width T _R shown by the recording pulse width T _W as a parameter. If the linear velocity slow, the temperature rise on the recording film becomes large, it tends to spread reproduction pulse width T _R with respect to the recording pulse width T _W. For this reason, when the recording power P is lowered, the gradient of the temperature distribution on the recording film surface at the time of light spot irradiation becomes gentle, and the recording film becomes more sensitive to fluctuations in sensitivity and recording power of the recording film. The fluctuation of the edge position increases. Therefore, stable optimum recording power position of the edge is a major power than the recording power P1 such that equal to the recording pulse width T _W and the reproduction pulse width T _R. On the other hand, the reproduction pulse width T
_{For R} , if the recording bit pitch and the modulation method are determined, the range that can be taken as shown in FIG. 6 is uniquely determined.
Then, the recording pulse width T _W is determined from the recording power P above the aforementioned reproduction pulse width T _R. This recording pulse width T _W
Becomes shorter than the reproduction pulse width T _R, shift a certain amount of time only it may take a range of reproduction pulse width (reproduction pulse width necessary for demodulation) from the linear relationship between the recording pulse width and the reproduction pulse width the setting recording pulse width region as shown in FIG. 6 is a set range of the recording pulse width T _W.

From the above examination results, at the time of recording, control is performed so that the recording pulse width _TW is corrected by a fixed time amount (correction pulse width) determined in accordance with the linear velocity with respect to the pulse width to be originally recorded (FIG. 9). reference). This is performed by a write pulse generation circuit (write pulse width control circuit) 33. The recording power P is also controlled by the write power switching circuit (WRT current control circuit) 39 so that the recording power P becomes the optimum recording power with little edge fluctuation according to the linear velocity. By these recording controls, stable pits corresponding to data to be recorded can be formed. In this embodiment, since use of the MCAV recording method, the recording power P, the correction pulse width [Delta] T _W is controlled in each zone is controlled to be equal in the zone.

The modulation method used for pit edge recording must be a method suitable for the recording characteristics of the optical disk.
Considering the recording characteristics as described above, it is advantageous that the shortest pulse width to be recorded as the pulse width after modulation is longer than the pulse width determined from the bit pitch because the linear region between the reproduction pulse and the recording pulse can be used effectively. Further, from the viewpoint of the reproduction characteristics, if the resolution is the same in the same optical system and the resolution is the same, it is preferable to detect the long hole because the signal level increases and interference between pits decreases. In view of the above, according to the expression method of the modulation method used for the magnetic disk, it is desirable that the shortest magnetization reversal time is T or more, where T is the bit interval time. In the current modulation scheme, a 1.33T sequence to a 1.5T sequence is more preferable.

As a specific example, a modulation method called (1,7,2,3) 1to7 modulation or (2,7,2,4) 2to7 modulation is preferable. In this embodiment, 2to7 modulation is used. However, in these modulation methods, although the shortest pit length is long, the width of a detection window for discriminating data is narrow, and therefore, it is necessary to suppress fluctuation of the edge position.
Among the recording media of optical disks, particularly, a recording film having a perforated shape has a very small number of disk noises corresponding to variations in the shape of pits, and is suitable for such a modulation method.

When this modulation method is used for edge recording, various problems occur when detecting a signal corresponding to an edge from a reproduced signal. That is, since the above-described modulation method has a signal component from DC to low band as a signal occupied band, the second
As shown in the figure, when an attempt is made to detect a signal corresponding to an edge as an intersection 7 between a fixed slice level 6 and a level converter of the reproduction signal 5, the reproduction signal 5 amplifies and transmits a signal from DC to a wide area. There is a need to. However, in general, signals cannot be handled from a direct current to a band due to problems of dynamic range, offset, and drift. Thus, as shown below, a point at which the level conversion of the reproduction signal 5 changes is detected as a signal corresponding to the edge.

In this way, only the signal component representing the change point is amplified,
Since transmission is sufficient, components in the low frequency range from DC are not required.

Hereinafter, a time chart of the recording signal / reproducing signal processing operation is shown in FIG. 9, and a block diagram of the recording / reproducing system is shown in FIG.
In order to detect the change point of the reproduction signal 5, as shown in FIG. 9, the signal level of the differential detection signal 80 of the reproduction signal 5 becomes large in the conversion unit. Therefore, the reproduced signal 5 is input to the differentiating circuit 81, and the level of the output of the differential detection signal 80 of the reproduced signal is determined by the level slicing circuit 82 to detect each edge position. Since the point at which the differential detection signal 80 of the reproduction signal 5 becomes maximum is the change point, the differential detection signal of the reproduction signal 5
80 is further differentiated, and a signal corresponding to an edge is detected using the zero-cross point and the above-described edge position signal. As a result, a signal corresponding to each edge can be stably detected by a normal signal processing circuit. In this signal detection method, since high-frequency components are amplified for each differentiation process in order to perform differentiation, low-pass filters 83 and 84 are provided for limiting to a required band. That is, as shown in FIG. 10, the flow of the entire signal is a signal obtained by photoelectric conversion by the photodetector 85.
After passing through 81, the signal passes through a low-pass filter 83 and is input to an AGC (automatic gain control) circuit 86 for adjusting the gain to a constant value. Each is input to the differentiating circuit 87. The band of the low-pass filter 84 is variable. The signal 97 differentiated by the differentiating circuit 87 enters a zero-cross detecting circuit 88. Zero detection circuit 88
Has two slice levels, E ₃ and E _{4. When} the differentiated signal crosses these levels E ₃ and E ₄ twice in succession,
A pulse indicating the crossing period is generated, and a zero-crossing pulse generated when the differential signal 97 crosses zero twice is gated by the pulse to generate a zero-crossing signal 89 indicating a change point of the reproduction signal. Level slice circuit 82
In first derivative signal 80 was sliced in two slice level E ₁ and E _2, the front edge position signal after indicating the location of the trailing edge and the edge position signal 90 before indicating the location of the edges
Generates 91. Each edge position signal 90, 91 output from the level slice circuit 82 and the zero cross signal 89 output from the zero cross detection signal path are input to the edge detection circuit 92, and the leading edge pulse 121 and the trailing edge pulse 11 corresponding to each edge are input.
Output 9

Considering the combined use of the MCAV recording method and this reproduction method, the recording pit length for each zone is almost equal,
In addition, since the rotation speed is constant, the signal band gradually increases in each zone from the inner circumference to the outer circumference of the disk radius. If the value of the filter 84 is fixed, the signal band is doubled, so that the noise value is generally doubled on the outer circumference compared to the inner circumference. Therefore, it is necessary to change the constant for signal processing for each zone, but if the number of zones is large, the circuit becomes complicated. In the case of a perforated medium, the noise that must be considered in the optical disk is dominated by the disk noise. The disc noise has the characteristic that the noise power occupying the entire signal band is equal even if the signal band increases compared to the white noise. Considering this characteristic, the number of band switching stages of the filter 84 can be reduced, and the number of zones can be reduced to about 1/10 of the number of zones.

The leading edge pulse 121 and the trailing edge pulse 119 are input to independent PLLs (phased locked loops),
The reproduction clock signals 501 and 503 are generated.

Window pulses 93 and 94 for detecting data are generated from the reproduced clock signal. In addition, the detection pulse of each edge which compensated the delay of PLL, circuit etc. from each edge pulse
95 and 96 are generated to discriminate the data depending on whether or not this is during a certain period of the window pulse. Therefore,
To detect data accurately, the edge pulses 121, 11
The nine time fluctuations must fall within the time width of the window pulses 93 and 94.

The causes of the time variation of the edge pulse are as follows.

Tc; fluctuation of reproduction clock Tp; dynamic fluctuation at the time of recording Tj; fluctuation at the time of reproduction Each edge data 502 and 504 output from the data discrimination circuit is input to the reproduction synthesis circuit 222. Here, edge data 502 and 504 are sequentially stored in the memories 606 and 607 in accordance with the reproduction clocks 501 and 503 created by the respective PLLs for each edge. The edge data stored in the memory is read according to another clock 514. At the time of this reading, the order of the data taken out from each memory is adjusted. In order to match the order, using the recording data in which the time interval between the leading edge and the trailing edge is known in advance, this recording data is detected, and the data corresponding to the edge before the recording data is compared with the data corresponding to the trailing edge. The data is read from the memory after being shifted by the clock corresponding to the time interval. In the optical disc, the PLL operation may be disturbed due to a defect or the like, and each edge data may be shifted in time. For this reason, the recording data is recorded at certain intervals, and when a time shift is detected, re-synchronization control for re-adjusting the order is performed. In this way, the fluctuation of the edge position necessarily caused by the recording principle of the optical disk is absorbed, and the data can be reproduced stably.

Hereinafter, a configuration example and operation of the reproduction / synthesis circuit 222 will be described with reference to FIGS. 11 and 12. The synthesis circuit 222
Pattern detection circuits 602 and 603, and memory A606 and memory B6
The write address control circuits 604 and 605 of 07, a memory output control circuit 608 and a data generation control circuit 609 are provided. FIG. 12 is a time chart showing the operation of FIG. 11, and will be used simultaneously in the following description. Ninth
As described in the figure, the edge data pulse 121 is
One is input to the circuit 600, and the VCO clock (VCOCKL1) 501,
Data (DATA1) 502 synchronized with the clock is obtained. The configuration of the VFO1 circuit may be a conventionally used one. Similarly, the VFO clock circuit (VCOCKL2) 503 and the data (DATA
2) 504 is obtained. In FIG. 12, data is shown to be valid at the rising edge of the corresponding clock. The data and clock are input to pattern detection circuits 602 and 603, and pattern detection signals 505 and 506 are output corresponding to the leading edge and trailing edge, respectively. Pattern detection circuits 602, 60
3 can be constituted by a shift register and a gate circuit for determining pattern coincidence. The configuration itself may be the same as the type conventionally used for detection of the demodulation synchronization pattern, for example, the type shown in the 51 to 4 ″ ISO format.
At 602 and 603, data “1” immediately after the output of the pattern detection signals 505 and 506 are output as detection pulses 507 and 510, respectively. As a circuit for this, for example, a D flip-flop is used, the flip-flop is set from the detection signal 505, and the data 502 that comes immediately after the Q output of the flip-flop becomes "H" becomes "H". When you do, you just have to output it. The same applies to the generation of the detection pulse 510. The address 508 of the memory A 606 starts counting up from the time when the detection pulse 507 is input. Similarly, the address 511 of the memory B607 is the detection pulse 5
Start counting up immediately after 10 is input. The memories A606 and B607 are serial input and parallel output memories. Write address 508 of memory A606
, The data 502 is written to the memory A606 by the clock 501. Similarly, the write address 511 of the memory B
, Data 504 is written to the memory B607 by the clock 503. Here, the write address 51 of the memory B
1 starts from “3”, this is a VFO pattern
This is because 420 uses a repetitive pattern of 1.5T, that is, a pattern that exists as one data “1” for three clocks in terms of the number of clocks. That is, when "1" of the leading edge data is written to the address "0", "1" of the trailing edge data is written to the address "3", but it should be at a normal position. . The operation time chart shown in FIG. 12 shows a case where a 1.5T repetition pattern is used as a reference pattern for reproduction / synthesis. Therefore, the address 508 of the memory A starts from "0" and the address 511 of the memory B starts from "0". It starts from 3 ". For example, if a repetition pattern of 2.0T is used as a reference pattern, the address 511 of the memory B may be started from “4”. If the data written in the memories A and B in this way is read by a common address,
This means that the reproduction and synthesis have been performed correctly. Output control circuit 60
According to 8, when the address 511 of the memory B activated by the detection pattern 510 is counted up to “4”, a data generation permission signal 514 is generated, and it is instructed that the following data string has been reproduced. Output of memory A and memory B
Data 130 can be obtained by sequentially reading 9,512 at the common address 513. As the clock 514, a clock 501 may be used. Also, the clock 503 or the recording clock used for pit recording can be used as long as the frequencies are equal. In this case, if the memories A and B are FIFO (first-in first-out) memories and the input side and the output side can be controlled by separate clocks, it can be easily realized. In the circuit configuration of FIG. 11, 8-bit memories are used as the memories A and B, but there is no particular limitation on the bit length.
After storing data of the entire sector using a memory having a data bit length of a sector, reading from the memory may be executed. However, when continuous sector reading is performed, it is desirable to select an appropriate bit length from the viewpoint of improving throughput. Preferably, it is several times the repetition interval of a specific recording pattern used for resynchronization control.

In the above, the edge recording characteristics and the recording control determined from the edge recording characteristics have been described, and the reproduction control for detecting the reproduction data from the recorded pits has been described. Next, in order to examine a specific format for MCAV recording, edge recording / reproduction characteristics when a Te-based ternary metal film (PbTeSe) is used, and specific recording control and reproduction control for this recording film. An example will be shown, and then the overall signal flow for recording and reproduction will be described.

The following conditions are employed to examine the edge recording / reproducing characteristics.

The methods include: (1) detection method; two-stage differential detection method (2) recording method; fixed time width pulse width correction (3) reproduction method; edge independent detection method (4) modulation method; 2-7 modulation (1) Optical system; spot diameter 0.77 μm (half width) wavelength 0.83
μm (2) Recording power fluctuation width; + 5%, -12% of set power (3) Recording light pulse waveform; Rising / falling 6 ns (4) Signal detector; Detects light transmitted through lens on one light receiving surface.

Under these conditions, the following measurement is performed while changing the rotation speed and the recording linear density. The phase jitter is measured by changing the recording power for each correction amount of one recording pulse width. Jitter is measured independently for the leading and trailing edges. The recording pattern used for the measurement is the worst pattern generated by the 2-7 modulation as shown in FIG. One example of this result is shown in FIG. Here, the fluctuation width of the recording set power is +5.
%, -12%, the set power at which the phase jitters at these fluctuating powers become equal is found.

One set power and the worst value of the phase jitter are obtained for each correction amount of one recording pulse width.

Next, the worst value of the phase jitter is obtained by changing the correction amount, and FIG. 15 is obtained. From this, the pulse correction amount that minimizes the worst value of the phase jitter is obtained.

From the above, the set recording power, the recording pulse width (correction amount), and the worst phase jitter at that time are obtained for one rotation speed and one linear density. When this is measured while changing the rotation speed and the linear density, the linear velocity dependence of the phase jitter using the linear density as a parameter as shown in FIG. 16 can be obtained. Here, the relative ratio to the detection window width determined from the linear density was taken as the jitter.

It can be seen from this characteristic that the jitter starts to increase sharply as the linear velocity is increased. The reason for this is that if the linear velocity is high, the amount of irradiation energy that escapes to the substrate becomes large, and the gradient of the temperature distribution on the recording film becomes gentle. It is considered that the fluctuation of the edge increases.

From such characteristics, the recording radius position is changed while the rotation speed is kept constant, and in a recording method such as MCAV in which the recording is performed while the linear velocity changes, while increasing the capacity,
In order to record and reproduce data with high reliability, it is desired that the magnitude of the phase jitter be equal over the inner and outer circumferences of the disk. For this purpose, as is clear from FIG. 16, the recording linear density may be changed for each linear velocity in accordance with the recording characteristics. It is preferable that the linear velocity be kept constant irrespective of the linear velocity, or that as the linear velocity increases, the other phase jitter also increases, so that it decreases as the linear velocity increases. In this way, the capacity is not limited by the recording characteristics at the specific radial position, and the detection characteristics do not become particularly severe at the specific radial position.

As such a format, the recording innermost radius Rm is now
Determine the number of sectors from in, the linear density, and the sector capacity.
It is conceivable to increase one sector in the AV zone. In this format, for example, track pitch
Assuming that 1.6 μm, the format efficiency is 72%, and the sector capacity is 1024B, the relationship between the number of innermost sectors and the storage capacity and the relationship between the recording pit pitch on the inner and outer circumferences of the disk at that time are 17th.
Obtained as shown in the figure. In this format, the innermost pit pitch of the disk can be made smaller than the outermost pit pitch. Using this format with a recording capacity of 3.2 GB, the jitter when the rotation speed is changed from 900 to 1200 rpm is obtained from FIGS. 16 and 17, and is as shown in FIG. From this figure, the worst phase jitter at the radial position can be obtained. When the worst jitter at each rotation speed is obtained by changing the capacity, the result is as shown in FIG. In this figure, the remaining portion excluding the worst jitter with respect to the entire detection window width is represented as a parameter. The storage capacity differs depending on what value can be taken as the remaining amount. This value is determined from the viewpoint of device design by the amount of jitter with respect to the fluctuation of other control elements, and is usually 30% to 60%. The value of the degree. Therefore, from the results in FIG. 19, it is possible to realize a rotation speed of 900 rpm or more and a storage capacity of 3 GB or more.
The minimum value of the transfer rate is 1 MB / s or more from the above-described linear density of 1.3 μm at the innermost circumference with the minimum rotation speed of 900 rpm and the minimum capacity.

The above formats reduce the number of tracks in a zone to 10
In this case, the number of lines is 24. At this time, if the linear density on the inner circumference of the disk is determined, the linear density on the outer circumference of the disk is limited to some extent in relation to the capacity. Therefore, in order to select the linear density on the inner and outer circumferences to some extent freely, a plurality of types of zones having different numbers of tracks are provided as follows, and by combining these, it is possible to control the desired linear density at an arbitrary radial position. it can. That is, the innermost recording radius; R
min, the number of tracks in the zone; N, the track pitch; p, the number of innermost sectors; n, the sector is increased by one sector for each zone from the inner circumference to the outer circumference due to the magnitude relationship between N × n × p and Rmin. Sometimes, the rate of change of the recording linear density can be changed, and can be monotonically increased or monotonically decreased. For example, if two types of zone # 1 of 1024 tracks and zone # 2 of 512 tracks are used, the rate of change in linear density of zone # 2 is negative, and the rate of change of linear density in zone # 1 is positive. If the ratios of zone # 1 and zone # 2 are 4: 1, 3: 1, 2: 2, respectively, and zones are sequentially arranged at this ratio, as shown in FIG. In comparison, even if the linear density at the innermost radius of the disk is determined, the linear density at each radial position can be controlled.

The format related to the arrangement of tracks has been described above. The format in a sector will be described with reference to FIG. 53Bytes pre-built preformat part 300 and 14Bytes flag area 301 and 130
It consists of a data area 302 of 9 bytes. Address information 303 indicating the position of a sector is duplicated recorded in the preformat unit 300, and a clock necessary for reading this address information is created. A synchronization signal 304 for the VFO and a synchronization signal indicating the start of the address information are generated. There is a mark 305. The address information 303 includes a track number TRH, TRL, a sector number SEC, a number ID # indicating any of double address information, and an error check code CRC used to perform an error check when detecting these signals. ing. Since 2-7 is used as the modulation method, extra bits may be generated after modulation. Therefore, an area 306 for absorbing this is provided. To explain with an example, CRC
If the data ends with "0100111", for example, "01
The modulation is divided into 0 "," 011 ", and" 1 ".The first three bits" 010 "are" 100100 "after the modulation, and the next" 011 "is" 001 ".
000 ", but since the last 1 bit" 1 "cannot be modulated by 2-7, it is modulated by adding 1 bit. If" 0 "is added here, the data" 0100111 "becomes" 1 ". Ten
01000010000100 ". At this time, the last" 00 "after modulation, which is increased by the added" 0 ", becomes redundant, and an area 306 is provided to absorb this. Flag area 3
01 includes an area TOF which is flat without a guide groove for correcting a track shift detection signal of a light spot, a buffer area GAP having no information, and an area 307 indicating a recording state in the sector. A data area 302 includes a signal 308 for starting a VFO for generating a clock for reproducing data, a synchronization signal 309 for adjusting the phase of the clock, an area 310 for user information, and a next sector. And a buffer area 311. Area 310 related to user information
Further includes user data and recording data control information DMP.
And an error correction code CRC and an error check code ECC added to reliably read these signals.
And a plurality of repetitively recorded data patterns Resymi used for resynchronization of the reproduction / synthesis described above. For the structure of user data and error correction code CRC,
It is based on the configuration of LDC (Long Distance Code) that has already been determined by standardization of optical discs. 1040 bytes including user data, control information DMP and error check code CRC
As shown in FIG. 22, s is divided into ten blocks, and a 16-byte Reed-Solomon error correction code is added to each block. When recording on a disk, the blocks are sequentially recorded in the direction of the arrow. The resynchronization data pattern Resymc described above is inserted every 40 bytes of the recording data.

In the recording characteristics, 830 nm is used as the laser wavelength to be used. However, when 780 nm is used as the laser, the resolution can be improved by the wavelength ratio of the laser. Therefore, the track pitch can be improved from 1.6 to 1.5 μm, and the linear density can be improved by the wavelength ratio. 83
With the jitter characteristic at 0 nm, 60% can be taken as the remaining phase jitter, and the capacity of the remaining jitter that is substantially equal over the entire radial position is 3.2 GB. When the track format is configured in consideration of the improvement in resolution by the 780 nm laser,
It looks like Figure 23. The storage capacity is 3.5 GB, and the transfer rate is 1.17 MB / s on the inner circumference and 2.22 MB / s on the outer circumference.

〔The invention's effect〕

According to the present invention, an unprecedented performance in which an optical disk having a disk diameter of 300 mm or more has a storage capacity used by a user of 3.0 GB or more per side and a transfer rate of 1 MB / s or more can be realized.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing a comparison between position recording and edge recording, and FIG.
FIG. 4 is a diagram showing the relationship between the number of zones and the storage capacity in the MCAV recording method, FIG. 4 is a block diagram of a controller unit according to an embodiment of the present invention, FIG. 6 and 7 show the relationship between the recording pulse width and the reproduction pulse width, FIG. 8 shows the relationship between the recording power and the time fluctuation of the reproduction signal, and FIG. 9 shows the time chart of the edge recording / reproduction control. FIG. 10 is a block diagram of a recording / reproducing system according to one embodiment of the present invention, FIG. 11 is a configuration diagram of a reproducing / synthesizing circuit, FIG. 12 is a time chart of the reproducing / synthesizing circuit, and FIG. A diagram illustrating a recording pattern,
FIG. 14 is a diagram showing the relationship between recording power and phase fluctuation, and FIG.
FIG. 16 is a diagram showing a relationship between a recording pulse width and a phase variation, FIG. 16 is a diagram showing a relationship between a linear density and a storage capacity, FIG. 17 is a diagram showing a format configuration according to an embodiment of the present invention, and FIG. The figure is
FIG. 19 shows a format of 3.2 GB / side, FIG. 19 shows a relationship between the number of rotations and storage capacity, FIG. 20 shows a method for controlling a linear density according to a recording radius position, and FIG. 21. FIG. 22 is a diagram showing a configuration of a sector format, FIG. 22 is a diagram for explaining a configuration of a data portion, and FIG. 23 is a diagram for explaining a 3.5 GB format.

Continued on the front page (72) Inventor: Atsushi Saito 1-280, Higashi Koikekubo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. Inventor Kuki Sugiyama 1-280 Higashi Koikebo, Kokubunji-shi, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. 56) References JP-A-56-35577 (JP, A) JP-A-61-131236 (JP, A) JP-A-62-239382 (JP, A) JP-A-62-185250 (JP, A) Sho 61-284876 (JP, A) JP-A Sho 58-177753 (JP, A)

Claims (1)

(57) [Claims] In an optical information recording medium having a plurality of sectors, each sector has a preformat section and a data area, and the preformat section indicates a position of the sector recorded by a specific modulation method. An optical information recording medium comprising: an address information area; and a PA area for absorbing an extra bit due to the modulation method.