JPS5933633A - Recording and reproducing device of optical information - Google Patents

Abstract

PURPOSE:To perform reading of only a sector where the information is written correctly, by discriminating assuredly a sector where the recording is incomplete which is generated with a track jump under recording and a sector where the double writing is carried out for replacement from a normal data where the data is already written. CONSTITUTION:A preamplifier is equal to an AC amplifier is an envelope detecting circuit, and therefore the low frequency component is assuredly suppressed by an HPF20 for a signal 100 which lost its DC component. An envelope curve wave detecting circuit 22 detects the envelope signal 103 after a clamping circuit 21 had a DC reproduction in order to increase the signal level of envelope detection. A comparator output 104 is applied to a counter 25, and clocks 106 of a clock generating circuit 26 are counted. The output 107 of the counter 25 is set at one with a prescribed count number of clocks. Then a latch 27 is set at one. The envelope detecting signal 105 is not delivered at a sector where the double writing is carried out. Therefore it is possible to discriminate a normal recorded sector where the signal 105 is delivered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of Industry-1- The present invention relates to an optical information recording and reproducing device that records and reproduces information on a rotationally driven disc-shaped recording medium (hereinafter referred to as a disk) using a light beam. In particular, the present invention relates to means for updating recorded information when the disc is recordable but recording signals cannot be erased.

Conventional configuration and its problems Recording and reproducing signals at high density on an optical recording disk by concentrating the light of a laser etc. into a beam with a diameter of 1 μm or less is often done when recording signals on the master disc of a video disk. ing. In addition, with the recent development of new optical recording techniques, digital signals and video signals are being optically recorded and reproduced on disks.

In addition, in order to record and reproduce high-density signals with a simple device, a disk with optically detectable guide tracks is used to transmit signals within and between the guide tracks along the guide tracks. Recording and playback are being carried out. As an example of the above-mentioned guide track, the depth is approximately % of the wavelength of the light from the light source used for recording and reproduction, and the width is 0.
It has been proposed to use grooves of 5-1 μm. These grooves are arranged spirally or concentrically at appropriate track pitches over the entire signal recording area on the disk.

Further, as another example of the guide track, a servo track on which servo signals are recorded in advance is formed, and signals are recorded and reproduced along this servo track.

FIG. 1 shows an example of this optical recording disk. In FIG. 1, only one signal recording guide track is shown for the purpose of simplifying the drawing. In FIG. 1, a guide track 2 of a disc 1 includes an address recording area A1°A2 to An and a sector S1. It consists of S2 to Sn.

Address A1. A2-An have a unique trunk address number and the following sector S1.A2 to distinguish track 2 from other tracks. Sector address numbers S2 to Sn are recorded in advance to indicate an address signal.

The address A1. Sector S1 divided by A2 to An
, 82 to Sn make it possible to record and reproduce data in sector units on the guide track 2.

Although the above-mentioned disk can record data, it does not have an erasing function, so new data cannot be recorded and reproduced in sectors where data has already been recorded.

Additionally, during recording on a disc, there are cases where the light beam that follows the guide track and records due to disturbances such as vibrations skips to other tracks, resulting in recording only on one part of the sector. It is difficult to accurately distinguish the corresponding sector from a read error caused by a defective disk.

In addition, since the disk size is very large, it is not possible to manage the address of the corresponding sector of the recorded data, so it is necessary to record the file management information of the data recorded on a specific track of the disk and manage the file. is desired.

Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and it is possible to distinguish between old data in recorded sectors and sectors in which the latest data is recorded, and to distinguish incompletely recorded sectors caused by track skipping from normal recorded sectors. It is an object of the present invention to provide an optical information recording and reproducing apparatus that can satisfactorily reproduce only the sectors in which the latest data is recorded among the normally recorded sectors by distinguishing between the two.

Constituent Structure of the Invention Means for modulating a laser light source to record data in a predetermined area of a designated guide track of a non-erasable recording medium; means for detecting an envelope of a recorded area of the guide track; and a means for detecting an envelope of a recorded area of the guide track; means for overwriting a special signal in the area, and the envelope detecting means detects an envelope of the data-recorded area and prevents the envelope of the overwriting area from being detected so as to detect the overwriting when reading the guide track. By configuring to skip areas for reproduction, even non-erasable recording media can be used efficiently.

DESCRIPTION OF THE EMBODIMENT FIG. 2 is a block diagram of an embodiment of the optical information recording/reproducing apparatus according to the present invention. In the figure, only blocks necessary for explaining the present invention are shown, and a search system and the like are not shown. In FIG. 2, an optical recording disk 1 is being rotated by a disk motor 3. As shown in FIG. The light beam emitted from the semiconductor laser 4 is focused in the form of a parallel beam onto the guide track of the optical recording disk 10 by the aperture lens 5, and a servo is applied to follow the guide track. Note that the focus servo and tracking servo blocks are not shown in the figure. The optical beat reflected by the guide track of the optical recording disk 10 is reflected by the polarizing beam splitter 6 in the surface angle direction and is incident on the 4-split optical detector 7. Although not shown, there is a % wavelength plate in the optical path between the polarizing beam splitter 6 and the aperture lens 6, which rotates the plane of polarization of the incident light beam and the reflected light beam by 90°C, and beats the reflected light at the polarizing beam splitter 6. I make it possible to do it in advance.

The reproduced signal output from the 4-split optical detector 7 is outputted to a preamplifier 8 as a readout signal 100 and a focus error signal.

The tracking error signal is processed and output.

The readout signal 100 is a reproduction signal of the signal recorded on the guide track and is applied to the demodulation circuit 9, the address reproduction circuit 10, and the envelope detection circuit 11. Address endogenous circuit 10
is the address A1. formed on the guide track. A2~An
A circuit that demodulates and reproduces the data, reads out the track address number and sector address number tracked by the light beam, and sends it to the sector write/read control circuit 12 and the control C.
Output to Pu13.

Data recording to a sector is started by activating the input/output device 14 by the control CPU 13 and storing data in the buffer memory 15. The data stored in the buffer memory 15 is divided into sectors and read out, and converted by the modulation circuit 16 into a signal form suitable for the recording/reproducing characteristics of the optical recording disk 1.

The modulation circuit 16 is activated when the sector write/read control circuit 12 detects that the track address and sector address specified by the control CPU 13 match the address output of the address reproduction circuit 10. At the same time, the demodulation circuit 9 is activated at the same timing when reading a sector.

A modulation signal 101 from the modulation circuit 16 is added to a superimposed signal 102 (described later) by an adder circuit 17, and is input to a 31' barrel laser drive circuit 18, which modulates the drive current of the semiconductor laser 4 and outputs laser light. A modulated signal 101 is recorded as a hole or a change in density in the recording portion deposited on the guide track by varying the intensity.Reading information from the recorded sector is performed by the control CPU 1.
The sector write/read control circuit 12 compares the address specified in step 3 with the reproduction address, and when the addresses match, the demodulation circuit 9 is activated.

The demodulation circuit 9V is composed of a waveform equalization circuit for correcting waveform deterioration of the read signal 100(7), a clock regeneration circuit, a data demodulation circuit, and the like. The data demodulated by the demodulation circuit 9 is stored in the buffer memory 16 and transferred to the input/output device 14 after sector reading is completed. When recording the sector, the envelope detection circuit 11 detects the data in the previously recorded sector at K-J- when recording the sector. This is a detection circuit to prevent erroneous double writing, and is used to check the presence or absence of recording before writing data into a sector. In fact, as will be described later, this circuit also distinguishes between normally recorded sectors and updated old recorded sectors.

When data is updated by recording new data in unrecorded sectors and also recording DC signals in sectors where old data is recorded, some sectors may be left unrecorded due to track skipping. ! FIG. 3 shows an overwriting process that can reliably distinguish incompletely recorded sectors from normally recorded sectors.

Figure 3A shows changes in the amount of reflected light from recorded sectors, and S
・ and S・ are normally recorded sectors) -1Ll-
1, and sector Sj is an example of a sector in which track skipping occurs. The opening in FIG. 3 shows the overwrite signal 102, which is generated by the overwrite signal generation circuit 19 in FIG. This overwrite signal 102 is transmitted to sectors S, -, as shown in the opening of FIG.
This is a DC signal that becomes ゛1''' during the period when data 1 is written into sectors S, , and Si. Overwriting signal 102 is forcibly applied to sectors S, , and Sj, ignoring the envelope detection of the envelope detection circuit 11. In the recorded state, as shown in Fig. 3, the recording focus of the modulated signal 101 of the data in almost the entire data write period of the sector is covered, resulting in a state where the reflectance is high. When the read signal 100 from the sector in the recording state passes through the envelope detection circuit 22 explained in FIG. 4, the envelope signal 103 becomes as shown in FIG. The level has dropped to a level where almost no output is produced.In this way, the overwritten sector is determined to be a normally recorded sector based on the waveform characteristics of the envelope signal;1OS.

FIG. 4 is a block diagram of an embodiment of the envelope detection circuit 11 for discriminating between the above-mentioned overwritten sectors and normal recorded sectors from the envelope waveform. In Figure 6,
The Ig waveform of each part in FIG. 4 is 0. This shows how the sector S among the recorded sectors 5i-1, Si, and Si+1 has been overwritten. In FIG. 4, the readout signal 100 of the preamplifier 8 has a waveform and power as shown in the opening of FIG. 5, in which the DC component of the change in the amount of reflected light shown in FIG. Ru.

The high-pass filter (HPF) 20 reliably suppresses low frequency components of the read signal 100.

The output of the HPF 20 is subjected to DC regeneration in a clamp circuit 21 in order to increase the signal level for envelope detection, and then
The envelope detection circuit 22 detects the envelope signal 103. The envelope signal 103 is binarized by the converter ζ-lator 23 so as to indicate the section exceeding the reference voltage 240, as shown in FIG. 5C. The comparator output 1o4 (FIG. 5-2) of the comparator 23 is applied to the count enable terminal of the counter 2S and the reset terminal of the S-R latch 27. The counter 25 counts the clock 106 of the clock generation circuit 26 by 1 when the comparator output 104 is 1'', and at a predetermined count, the output 107 of the counter 26 is set to 1'' and the latch 27 is set to 1.
Set to 1'°. Lanoji 27 is comparator 104
It is cleared when becomes 0''.

Figure 6 E shows the envelope detection signal 1 at the output of the latch 27.
It is 06. Since this envelope detection signal 105 is not output in the overlapped sector S, the envelope detection signal 105 is output in the normal recorded sector 5i.
-11Si, etc., can be completely distinguished.

Next, we will explain how to read the updated data when the data is updated by the overlapping omitting process described in -.
The data in sectors S3 and S4 of files 1 to 84 are updated and the data in sectors S6. This figure shows when a new file is created in sectors S1 to 86 by recording data in S6. Sector S3. In S4, the overwriting process of the present invention is performed. FIG. 6A shows changes in the amount of reflected light in sectors, and sector S3. S4 is overwritten. The flowchart for reading data from sector S1 to 86 in the new file is shown in the seventh section.
As shown in the figure. First, a sector envelope check is performed. This is done by checking the envelope detection signal 106 shown in FIG.
One portion is stored in the memory of U13. Next, the presence/absence of the envelope detection signal 105 is checked, and sectors S3. S4 is skipped and sectors S1. S2. S6. S6 is sequentially read out up to the final sector S6. of course,
In FIG. 7, the presence/absence of an envelope is determined by referring to the memory contents used at the time of envelope checking.

In the following explanation, the overwriting signal 102 is a DC signal, but the minimum noise width (minimum bit width) of the modulation signal 101
This objective can be similarly achieved even if AC signals of twice or more are recorded.

Effects of the Invention As is clear from the detailed explanation above, according to the present invention, incompletely recorded sectors caused by track skipping during sector recording and sectors overwritten for updating can be replaced by normal recording. Since the sector table in which data is recorded can be reliably distinguished, it is possible to easily read out only the sectors in which data has been written correctly.
Therefore, it is possible to update data on optical recording discs that do not have an erasing function.

[Brief explanation of drawings]

FIG. 1 is a plan view schematically showing an example of an optical recording disk;
Fig. 2 is a block diagram of an embodiment of the optical information recording internal generation device of the present invention, Fig. 3 is an operational waveform diagram that does not show the overlapping of recorded sectors, and Fig. 4 is an envelope detection circuit. A block diagram showing one embodiment, FIG. 5C is an operation waveform diagram showing signal waveforms of each part of the envelope detection circuit, and FIG. 6 is an operation waveform diagram illustrating sector reading when data is updated by overwriting. , FIG. 7 is a flow chart thereof. 1... Optical recording disk, 2... Guide track, 3... Disc motor, 4...
・Semiconductor laser, 6...Aperture lens, 6...
...Polarizing beam splitter, 7...4-split optical detector, 8...Preamplifier, 9...
・Demodulation circuit, 10...Address regeneration circuit, 11.
... Envelope detection circuit, 12 ... Sector write/read control circuit, 13 ... Control CPU. 14... Input/output device, 16... Buffer memory, 16... Modulation circuit, 17...
Addition circuit, 18... Semiconductor laser drive circuit, 1
9... Car marking signal generation circuit, 20...
・High-pass filter, 21...clamp circuit,
22... Envelope detection circuit, 23... Comparator, 24... Reference power supply, 25...
...Counter, 26...Clock generation circuit, 2
7... S-R latch, ioo... Read signal, 101... Modulation signal, 102...
...Overwrite signal, 103...Envelope signal,
104... Comparator output, 105...
...Envelope detection signal, 106...Clock.

Claims (1)

[Scope of Claims] (1) means for modulating a laser light source to record data in a predetermined area of a designated guide track of a non-erasable recording medium; and means for detecting an envelope of the recorded area of the guide track; means for overwriting a special signal on the recorded area of the guide track, and the envelope detecting means detects an envelope of the data recorded area and prevents the envelope of the overwritten area from being detected so that the envelope of the overwritten area is not detected. 1. An optical information recording/reproducing apparatus characterized in that the overwritten area is skipped during reproduction. Optical information according to claim 1, characterized in that the special signal to be overwritten in the overwritten area is a DC signal, and brings all the recording portions in the overwritten area into a recorded state. Recording/reproducing device. ('4 Scope of claims for il ¥ ¥ 1, characterized in that the special signal overwritten in the overwriting area is an AC signal capable of recording -1- or more than twice the shortest recording pit length of the recording area. 1st
The optical information recording and reproducing device described in 2. (4) The envelope detection means is characterized in that it includes a high-pass filter that suppresses the envelope of the reproduced signal from the overwritten area, and detects only the envelope of the recorded area that is not overwritten. An optical information recording and reproducing device according to claim 1 or 14.