JP3066758B2 - Optical information recording method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical information recording method.

2. Description of the Related Art An example of a conventional optical information recording / reproducing apparatus will be described with reference to FIG. First, at the time of reproduction, the semiconductor laser 1 is driven by the laser drive circuit 2 to perform DC lighting with the reproduction power, whereby the light emitted from the semiconductor laser 1 is made into parallel light by the coupling lens 3 and the beam splitter 4 , 1/4 wavelength plate 5 and sequentially condensed by an objective lens 6, and irradiates the surface of an optical information recording medium 7. The light reflected by the optical information recording medium 7 again passes through the objective lens 6 and the quarter-wave plate 5 again in sequence, and passes through the beam splitter 4.
And passes through the condenser lens 8 toward the knife edge prism 9. The light reflected by the knife edge prism 9 is received by the two-divided light receiving element 10,
A track error signal can be obtained by sending the received signal to the arithmetic circuit 11 and calculating the difference between the signal outputs, thereby sending the track error signal to the tracking drive circuit 12 to drive the actuator and perform tracking control. be able to.

The light that has passed through the knife edge prism 9 is received by the two-divided light receiving element 13, and the received signal is sent to the arithmetic circuit 14 to obtain a difference in signal output, whereby a focus error signal can be obtained. Thereby, the focus control can be performed by sending the focus error signal to the focus drive circuit 15 to drive the actuator. Further, an analog reproduction signal can be obtained by sending the output signal of the two-division light receiving element 13 to the arithmetic circuit 16 and calculating the difference between the outputs.
And demodulated to obtain a reproduced signal.

On the other hand, at the time of recording, the recording signal is input to the modulation circuit 18 and modulated to be sent to the laser drive circuit 2 so that the semiconductor laser 1 is irradiated on the surface of the optical information recording medium 7 with the recording power according to the modulation signal. Thus, recording can be performed.

Problems to be Solved by the Invention In the optical information recording medium 7 on which data is recorded in the conventional optical information recording / reproducing apparatus as described above, in addition to a normal data area, a data area for recording data in this data area is used. In some cases, a test area for setting an optimal light amount condition is formed. An example of such an optical information recording medium having a test area is disclosed in JP-A-63-228417 as a "data recording method". In this case, when recording data in the data area,
Test data is recorded in the test area under different conditions in advance, and the optimum recording conditions are determined by checking the reproduction of the data, and actual data recording is performed.
The test data recorded in the test area only turns on / off the recording beam, and merely records a repetition of “0” and “1” as data.
However, the optimum recording condition is not determined only by repetition of '0' and '1', but is determined by one or more continuous '1' or one or more continuous '0' random data. Things. In other words, data of simple '0' or '1' as described above is recorded by changing the repetition condition, and '0'
Even if the recording condition allows discrimination between data '1' and data '1'
If there is a continuous area, there remains a question as to whether or not the reproduction is possible. Further, even if the reproduction is possible, there is a problem that the reliability is lowered because the recording is not optimal.

Means for Solving the Problems A repetitive pattern of 0 and 1 and a pattern having one or more continuous 0s separated by two or more continuous 1s and 2
In the test area, an independent pattern having one or more consecutive 1's sandwiched between two or more consecutive 0's is recorded in advance in the test area. Independent patterns sandwiched by two or more consecutive 1s by comparing with the first independent 0 portion of the pattern having one or more consecutive 0s which are sandwiched between 1 or more consecutive 1s A recording condition for equalizing the first independent zero portion of the pattern having one or more consecutive zeros is set, and one part of the repeated pattern of the zeros and ones is set to the two or more consecutive zeros. In comparison with the independent first portion of the pattern having one or more continuous ones sandwiched between two or more independent one or more continuous ones sandwiched between the two or more consecutive zeros Independent of the pattern having one Set a recording condition to equalize the first th 1 part of, and to perform recording of data in the data area of the original to the optical information recording medium of the set optimum recording condition.

Operation As a result, predetermined test data is written in the test area in advance, reproduced and detected at a predetermined timing, and a reproduction signal is detected to determine an optimum recording condition. This makes it possible to perform optimum recording without causing any trouble, and in addition, it is possible to reduce the test area as compared with the related art.

Embodiment An embodiment of the present invention will be described with reference to FIGS. Since the entire configuration of the optical information recording / reproducing apparatus has been described in the related art (see FIG. 7), the description is omitted here, and the same parts are denoted by the same reference numerals.

It is assumed that a data area and a test area (not shown) are formed on the optical information recording medium used here. Then, first, test data is written in the test area prior to recording in the data area. FIG. 1 shows the state of the pattern written in the test area. In this case, the pattern is a repeated pattern of data '0' and '1' at a bit interval 'T'. The pattern is a pattern having one or more independent 0s sandwiched between two or more consecutive 1s, and here, there is one independent data '0' after the continuation of data '1', and Are also continuous data '1'. The pattern is a pattern having one or more consecutive ones sandwiched between two or more consecutive zeros. In this case, in contrast to the pattern, one piece of independent data '1' is formed after data '0' is continued. ', And after that, data' 0 'continues.

Test data consisting of these various patterns
As shown in FIG. 2, by switching the switch element 19 and directly inputting it to the laser drive circuit 2 without passing through the modulation circuit 18, recording in the data area is performed.

The recording pulse a in FIG. 3 shows a waveform input as the initial condition of the test data, and the width of the recording pulse.
The pattern is recorded byte by byte with Twa and recording power Pw. At this time, if the width Twa is too wide, the analog reproduction signal of the arithmetic circuit 16 (see FIG. 7) is
It has a waveform like the analog reproduction signal A in the figure. And
This analog signal A is converted to A /
Perform D conversion. In this case, since the width Twa of the recording pulse a is too wide, the waveform rises due to overwriting as in the P portion of the analog reproduction signal A, thereby causing '1'.
The A / D conversion data in the independent '0' part c present in the continuous pattern of '0' part in the repeated pattern of '0' and '1' Become.

Therefore, next, the A / D conversion data of "a" and "c" are compared (by a CPU or the like), and Twa is changed based on the comparison result so that more optimal recording conditions can be obtained.
That is, as shown in FIG. 3, the recording of the test area is performed by narrowing the Twa of the recording pulse a and setting the Twa of the recording pulse b to Twb. Then, when this is reproduced, it becomes a waveform like the analog reproduction signal B in FIG. At this time, the A / D conversion is performed again at the timings A, B, C, and D as in the case described above. Thus, A and C are at the same level, so that the pulse width Twb is an appropriate condition for the '0' portion. However, in the waveform of the analog reproduced signal B, the point "b" of the "1" portion in the repeated pattern of "0" and "1" and the independent "1" portion existing in the continuous pattern of "0" are When compared with the two points, the level of the two is smaller. The reason why d becomes smaller in this way is that when data '0' is continuous, the first portion of the next data '1' has no preheating of the semiconductor laser 1 and the writing is delayed. is there.

Then, next, in order to correct such a phenomenon, as shown in the recording pulse c in FIG.
In the case where there are more than one test data, the next test data '1' is recorded slightly forward (width Twp) so that a waveform like the analog reproduced signal C in FIG. Obtainable. And I, Lo, Ha,
By performing A / D conversion at the timing of d and comparing a and ha and b and d, respectively, the values of a and ha corresponding to the '0' part can be equalized, and also correspond to the '1' part It is also possible to make the values of b and d equal, which indicates that the recording is performed with the optimum recording pulse width.

As described above, recording is performed using the test pattern in FIG. 1 as test data, and this is A / D-converted at predetermined timings (a, b, c, d) to obtain "0" and "1". By comparing the A / D conversion data of the repetition pattern with the A / D conversion data of the independent '0' in the continuous '1' or the independent '1' in the continuous '0', Optimal recording conditions for recording in the area can be obtained, which makes it possible to cope with sensitivity variations due to media (optical information recording medium) and changes in sensitivity due to changes in ambient temperature. The optical information recording medium 7
Since the optical disk used as a disk may have a defect, etc., the test data shown in FIG. 3 is repeatedly stored a plurality of times, and at the time of reproduction, the A / B, A, C and D data shown in FIG. The effects of defects and the like can be removed by taking D-converted data and accumulating the data A, B, C, and D, respectively, and comparing them, whereby more accurate optimum recording conditions can be obtained.

Next, a modified example of the test data recorded in the test area will be described. FIG. 5 shows a modified example of the test data, in which two continuous'0's follow the data '1' as a pattern, followed by a continuous state of the data '1', or the data as a pattern. Two consecutive data "1" are used after "0" is continuous, and then data "0" is used continuously. FIG. 6 shows a waveform of test data in which such various waveforms are recorded in the test area and a waveform of an analog reproduced signal when the waveform is reproduced. In this case as well, the optimum recording conditions in the data area can be obtained by sampling and comparing “0” at the timing of “H” and “1” at the timing of “H” and “H”.

In the above-described example, only the pulse width of the recording pulse waveform is changed. Alternatively, the recording power and the bottom power may be changed.

As described above, the present invention provides a repetition pattern of 0 and 1 and 2
In the test area, a pattern having one or more continuous zeros and one or more consecutive ones sandwiched between two or more consecutive zeros is recorded in the test area in advance. In reproducing the test area, an independent first one of patterns having 0 or more continuous 0s sandwiched between the 0 portion of the repeated pattern of 0s and 1s and the 2 or more continuous 1s Comparing the zero part of the eye with the independent first of the patterns having one or more continuous 0s sandwiched between the two or more continuous 1s
A recording condition for equalizing the 0-th part of the pattern is set, and a pattern having one or more consecutive ones sandwiched between one part of the repetitive pattern of the zeros and ones and the two or more consecutive zeros is set. An independent first portion of the pattern having one or more consecutive ones sandwiched between the two or more consecutive zeros by comparing with the independent first portion of the first portion; The recording conditions are set to be equal to each other, and data is recorded in the data area of the optical information recording medium under the set optimal recording conditions. This makes it possible to perform optimum recording in the data area without performing the test, and furthermore, it is possible to reduce the test area as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a waveform diagram showing the state of various patterns recorded in a test area, FIG. 2 is a circuit diagram showing a conversion circuit for recording test data, and FIG. 3 is a waveform of a test data waveform and various recording pulses. FIG. 4 is a waveform diagram showing waveforms of test data and various analog reproduction signals,
FIG. 5 is a waveform diagram showing a modified example of various patterns of test data, FIG. 6 is a waveform diagram showing a state of the test data waveform and an analog signal waveform, and FIG. 7 is a configuration showing an example of an optical information recording / reproducing apparatus. FIG. 1 ... Semiconductor laser, 6 ... Objective lens, 7 ... Optical information recording medium

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Claims (1)

(57) [Claims] 1. A pattern having a repeating pattern of 0 and 1 and a pattern having one or more continuous 0s sandwiched between two or more continuous 1s and a pattern having one or more independent zeros sandwiched between two or more continuous 0s A pattern having a 1 is recorded in the test area in advance, and at the time of reproduction of the test area, one or more continuous patterns sandwiched between the 0 portion of the repetitive pattern of the 0 and 1 and the two or more consecutive 1s are reproduced. Of the pattern having 0s, and comparing the 2
A recording condition is set for equalizing the first independent zero portion of the pattern having one or more consecutive zeros interposed between one or more consecutive ones. Is compared with the first independent part of the pattern having one or more consecutive ones sandwiched between the two or more consecutive zeros, and the two or more consecutive zeros are compared. The recording condition for equalizing the independent first portion of the pattern having one or more independent ones sandwiched between the two is set, and the optical information is set under the set optimum recording condition. An optical information recording method, wherein data is recorded in a data area of a recording medium.