JP2766172B2 - Optical information recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording apparatus, and more particularly to an optical information recording apparatus for reproducing and recording data by using an optical head having one laser and two lasers dedicated to recording.

[0002]

2. Description of the Related Art Conventionally, optical information recording devices include a read-only device, a write-once device capable of writing and reproducing once, a magneto-optical recording system and a phase change recording system capable of reproducing and rewritable recording, and the like. There are rewritable devices.

[0003] As a recording method in these optical information recording apparatuses, there are a pit position recording method using data at the center of the pit and a pit edge recording method using data at the edge of the pit.

First, a conventional pit position recording type optical information recording apparatus will be described with reference to the drawings.

FIG. 3 is a block diagram for explaining processing during reproduction and recording of the conventional optical information recording apparatus.
FIG. 3A is a diagram for explaining processing during reproduction, and FIG.
FIG. 8 is a diagram for explaining processing at the time of recording.

At the time of reproduction, as shown in FIG. 3A, an optical head 1 for reproducing and recording data with one laser.
In step 5, a laser spot is emitted with an arbitrary reproducing laser power, data is reproduced from the information recording medium 16, data demodulation 17 is performed, interleaving is performed, and error correction 13 is performed.
To restore the original data. This data is transmitted to the host device 1 via the interface 12.

[0007] At the time of recording, as shown in FIG.
The optical head 15 performs data modulation 14 for recording, and performs reproduction and recording with one laser, after adding an error correction code by an error correction 13 through an interleave.
Then, a laser spot is emitted by an arbitrary recording laser power to record the modulated data on the information recording medium 16.

Next, a conventional pit edge recording type optical information recording apparatus will be described with reference to the drawings.

FIG. 4 is a diagram for explaining a conventional pit edge recording method, FIG. 4A is a diagram showing a code word,
FIG. 4B shows a recorded pit array, and FIG.
FIG. 7 is a diagram showing a reproduced detection signal.

At the time of reproduction, as shown by the pit arrangement in FIG. 4B, after adjusting the laser spot to an arbitrary read power by the laser A, the laser spot 1 emits light along the recording track of the information recording medium. The recorded pit data signal is detected. As shown by the detection signal in FIG. 4C, when a change in the reproduced analog waveform is monitored, a level change occurs in the electrical signal of the detection signal with respect to an arbitrary time axis, and the level is compared with a preset level 1. By doing so, the pit data is determined. When the electrical signal of the reproduced waveform has changed and the level has reached level 1, the pit data is set to "1". When there is no change in the electrical signal of the reproduced waveform, the pit data is set to "0" regardless of the level 1. ". Then, the data is shown in FIG.
It is converted into the code word of (a) to obtain valid pit data.

At the time of recording, the laser A emits a laser spot for the code word shown in FIG. The relationship between the pit data and the laser A is defined as follows in the recording process. When recording the pit data of “1”, the laser 1 emits a laser spot 2 with an arbitrary write power. When recording pit data of "0", recording is performed with the same data as the previous pit so that the detection signal does not change according to the previous pit recording.

In the pit edge recording method, compared with the pit position recording method using the center portion of the pit as data, recording is performed at both edges of the pit.
Although a denser pit arrangement is possible, the recording density can be increased. However, at present, the capacity can be doubled as compared with the pit position recording method.

[0013]

In the pit position recording method of the above-mentioned conventional optical information recording apparatus, the recording density can be increased as compared with the pit position recording method. The increase in recording capacity was also about twice.

[0014]

SUMMARY OF THE INVENTION An optical information recording apparatus according to the present invention uses a laser spot to reproduce and reproduce data on a track of an information recording medium having concentric or spiral grooves and tracks using the grooves. In an optical information recording apparatus for performing recording, an optical head having one first laser for reproducing and recording data and two second lasers exclusively for recording, and data modulated by the optical head for two times. A recording function of recording one pit recording area of a track by one first laser and two second lasers in pit units, and a predetermined slice of a detection signal of data recorded by the recording function. And a reproduction function of performing detection and reproduction with one first laser at the level.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram for explaining processing at the time of reproduction and recording of an embodiment of an optical information recording apparatus according to the present invention.
FIG. 1A is a diagram for explaining processing during reproduction, and FIG.
FIG . 1B is a diagram for explaining a process at the time of recording , and FIG.
FIG. 4 is a diagram showing an arrangement of lasers of a recording / reproducing optical head .

During reproduction, FIGS. 1A and 1C are referred to.
And a laser for reproduction selected by the laser controller 10,
The pit data information recorded on the medium is reproduced from the information recording medium 6 by the first laser 18 of the optical head 5 using a laser spot with an arbitrary reproduction laser power, and the detection signal obtained from the reproduction laser spot is reproduced. It is detected as an electrical signal of the analog waveform. Then, the level converter 9 monitors the rate of change of the electric signal, reproduces pit data at a predetermined electric signal level (slice level), and reads the data recorded on the information recording medium 6 as “ 00 "," 01 "," 10 "," 1 "
The pit data is detected as pit data having any one of two pit arrangements of 1 ". Further, in order to obtain continuous pit data from the two pit data arrangement, the pit data is arranged by the code word converter 8 to generate effective pit data. Then, the pit data is demodulated 7 to deinterleave the data, to perform error correction 3, and to restore the recorded data, which is transmitted to the host device 1 via the interface 2.

[0018] During recording, FIG. 1 (b), reference to (c)
After receiving data from the host device 1 via the interface 2, adding an error correction code in the error correction 3 and interleaving the data, the data is modulated 4 for recording,
Then generate code word converter 8 in 1 pit of pit data array of two pit units from continuous pit data, and control any of the recording laser by the laser controller 10, the optical science head 5 and the first laser 18 2 The second
The lasers 19 and 20 are controlled to emit a laser spot with an arbitrary recording laser power to record pit data on the information recording medium 6.

Next, an information recording method by the optical information recording apparatus of this embodiment will be described with reference to FIGS.

FIG. 2 is a diagram for explaining an information recording method by the optical information recording apparatus of the present embodiment, FIG. 2A is a diagram showing a code word, and FIG. 2B is a diagram showing a recorded pit array. FIG. 2 (c) shows the reproduced detection signal.
(D) is a diagram showing a level determination criterion of a detection signal.

At the time of reproduction, as shown by the pit arrangement in FIG. 2B, after the laser B by the first laser 18 adjusts the laser spot to an arbitrary reproduction laser power, the laser B follows the recording track of the information recording medium. As in the conventional optical information recording apparatus, the pit data signal recorded by emitting the laser spot 1 is detected. The detected signal is shown in FIG.
As shown by the detection signal (c), the level converter 9 monitors the change in the reproduced analog waveform, and detects the electrical signal level when the electrical signal level of the detection signal changes with respect to an arbitrary time axis. The pit data is determined by comparing it with a predetermined electric signal level (slice level). As shown in FIG. 2D, when the electric signal of the reproduced waveform changes and does not reach level 1, the pit data is set to "01", and when the electric signal of the reproduced waveform changes, as shown in FIG. When the level reaches 1 but does not reach level 2, the pit data is "10". When the electrical signal of the reproduced waveform changes and reaches level 2, the pit data is "11". When there is no change in the electrical signal, the pit data is reproduced as "00" regardless of level 1 and level 2. Then, the code word converter 8 converts the data of the two-pit data array into a continuous one-pit processable data array.

At the time of recording, one of the codewords shown in FIG.
The pit data of the pit is converted into a continuous code word of two pits by the code word converter 8, and a laser spot is emitted from an arbitrary laser by the laser controller 10. The relationship between the pit data and the three lasers is defined as follows in the recording process. When recording “01” pit data , the second laser 19
A is a laser spot 2 with an arbitrary recording laser power
Is emitted, and when the pit data of “10” is recorded , the second
Laser spot 2 by laser A from laser 19
The laser spot 3 by the laser B from the first laser 18 emits light at an arbitrary laser power, and when recording the pit data “11”, the laser A from the second laser 19
A laser spot 2 according to the first laser 18 and the laser spot 3 by laser <br/> The B from the second and the laser spot 4 due <br/> laser C from the laser 20 is any laser power
And record different pit data. The "00" pit data corresponds to the same data as the previous pit so that the detection signal does not change in accordance with the previous pit recording as in the conventional pit edge recording method.

[0023]

As described above, the optical information recording apparatus of the present invention performs recording and reproduction by using an optical head having one laser and two lasers dedicated to recording, thereby achieving the conventional pit edge recording. There is an effect that data recording can be performed about twice as much as the method and about four times as much as the conventional pit position recording method.

Further, since the optical information recording apparatus of the present invention can process data of two pits at a time, there is an effect that the data recording and reproducing time can be reduced to one half of the conventional recording method.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining processing at the time of reproduction and recording of an embodiment of an optical information recording apparatus according to the present invention. FIG. 1A is a diagram for explaining a process at the time of reproduction. FIG. 1B is a diagram for explaining a process at the time of recording. FIG. 1C shows a laser arrangement of the recording / reproducing optical head.
FIG.

FIG. 2 is a diagram for explaining an information recording method by the optical information recording device of the present embodiment. FIG. 2A shows a code word. FIG. 2B is a diagram showing a recorded pit arrangement. FIG. 2C is a diagram showing the reproduced detection signal. FIG. 2D is a diagram showing a reference level for detecting a signal level.

FIG. 3 is a block diagram for explaining processing at the time of reproduction and recording of an optical information recording apparatus of a conventional example. FIG. 3 (a)
FIG. 8 is a diagram for explaining processing during reproduction. FIG. 3 (b)
FIG. 8 is a diagram for explaining processing at the time of recording.

FIG. 4 is a diagram for explaining a conventional pit edge recording method. FIG. 4A is a diagram showing a code word. FIG. 4B shows the recorded pit arrangement.
FIG. 4C is a diagram showing the reproduced detection signal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Host device 2 Interface 3 Error correction 4 Data modulation 5 Optical head 6 Information recording medium 7 Data demodulation 8 Code word converter 9 Level converter 10 Laser controller 11 Host device 12 Interface 13 Error correction 14 Data modulation 15 Optical head 16 Information recording medium 17 Data demodulation 18 First laser 19 Second laser 20 Second laser

Claims (2)

(57) [Claims] 1. An optical information recording apparatus for reproducing and recording data with a laser spot on a track of an information recording medium having a groove on a concentric circle or a spiral and a track using the groove, An optical head having one first laser for performing reproduction and recording and two second lasers dedicated to recording,
A recording function of recording data modulated by the optical head in a one-pit recording area of the track in units of two pits using the one first laser and the two second lasers, respectively; An optical information recording apparatus having a reproducing function of detecting and detecting a detection signal of data recorded by the above-mentioned one first laser at a predetermined slice level. 2. A laser controller for controlling the one first laser and the two second lasers according to the content of the data, and determining a change in a reproduction waveform reproduced by the reproduction function to reproduce the data. 2. The optical information recording apparatus according to claim 1, further comprising: a level converter for converting the converted data into a processable array; and a codeword converter for controlling a codeword converted by the level converter.