JPH01227227A - Data recording and reproducing control method - Google Patents

Abstract

PURPOSE:To prevent the defective reproducing of data by making a switching signal by an interpolating signal at non-detecting time of a sector mark. CONSTITUTION:The counter CT 41 of a SM interpolating signal making circuit 4 forecasts the predetermined position of the SM signal based on the SM detection signal. In this case, it is reset by a SM detection signal 103, set just before the position of the SM signal estimated next and even in case of the next SM signal being not detected by counting a clock it is reset by counting until immediately after the position thereof. The CT 41 generates a SM detection estimating gate signal 106 therefore. An interpolating signal making part 42 generates an interpolating signal 104 at the time when the signal 103 is not detected at the scheduled position by the signal 106, feeding it to an ID/data changing signal making circuit 5. In the circuit 5 the ID/data changing 105 is generated at the timing corresponding to the data range of the next sector, fed to a selector 8 and the ID and user data are alternately output.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data recording and reproducing control method in an optical recording and reproducing device, and in particular, sector marks (hereinafter abbreviated as "SM"), track numbers, Relating to a data recording and reproducing control method suitable for switching the recording and reproducing method between an identification signal of a different recording and reproducing method and user data even when an identification signal such as a sector number (hereinafter abbreviated as rlDJ) is not detected. It is something.

[Conventional technology]

In general, in a rewritable optical disk recording/reproducing device, there is a sector mark SM representing the start point of each sector, which is a unit of information recording, and an identification mark SM that is recorded following the sector mark and representing the track number or sector number. The method for recording and reproducing the signal ID is different from the recording and reproducing means for user data that is recorded to the effect that it is rewritable after the ID. FIG. 2(a) shows a sector format 100 of this type of optical disc, in which the SM part and ID part □ of one sector are preformatted in advance.
Recording is done by drilling holes (bits) on the recording film. Each sector has a predetermined fixed length, and these SM and ID sections cannot be rewritten or erased. On the other hand, the user data section is a recording section that can be erased and rewritten, such as in magneto-optical recording and reproduction, and data is recorded by methods such as changing the magnetization direction of the recording film. . For example, in perpendicular magneto-optical recording, recording is performed by changing the magnetization direction from directly below to directly above depending on data.

Reproduction of recorded information can be performed by a common (or separate) optical reproducing head for the SM, ID section, and data section, but since the recording method of each information is different,
The recording/reproducing circuit must be suitable for each method (for example, have different gains, etc.). In FIG. 2(a), "buffer" is a part for switching the recording/reproducing method by a switching signal after the data section ends and before entering the next SM.

In the conventional device, in order to adapt the recording and reproducing circuit to each recording and reproducing method, a recording and reproducing circuit for SM and ID and a recording and reproducing circuit for user data are provided, and in the reproduction mode of the ID section, the SM and ID are Based on the detected signal, a switching signal for the ID section and the data section is created, and the image recording/reproducing circuit is switched to each recording/reproducing method. A known example of this type is JP-A-62-
There is a publication No. 184627.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, no consideration is given to the problem when the SM or ID cannot be detected due to dust adhering to the disk or defects occurring on the disk. In other words, when SM and ID are not detected due to the above reasons, it is not possible to create a timing signal (switching signal) to switch the image recording and playback method (circuit), so the playback mode of the ID section remains set. As a result of reproducing the data portion in this state, there is a problem in that the recorded data cannot be sufficiently reproduced.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a data recording and reproducing control system for an optical recording and reproducing apparatus, in which the recording and reproducing of the ID section and the user data section can be performed even when the SM and ID are not detected. The purpose is to create a switching signal (timing signal) for switching formats to prevent data reproduction failures.

[Means to solve the problem]

In order to achieve the above object, in the data recording/reproduction control system of the present invention, in addition to the SM, ID detection means, switching signal generation means, and recording/reproduction format switching means using the switching signal, ) is not detected, an interpolated signal is created in place of the undetected signal. A switching signal (timing signal) for switching the recording/reproducing method is created using the interpolation signal. The switching signal is configured to switch the recording/reproducing method even when no SM or ID is detected.

[Effect]

The operation based on the above configuration will be explained.

The interpolation signal (SM signal for interpolation) output from the SM interpolation signal generation circuit is the SM signal only when SM and ID are not detected.
It is output to a position shifted by a predetermined timing from the expected detection position. The switching signal generating means (ID section/data section recording/reproducing method switching signal generating circuit) outputs a switching signal from a predetermined position after receiving the interpolation SM signal. The switching signal is applied to the switching means for the recording/reproducing method of the ID section/data section, where the recording/reproducing method of the ID section/data section is switched and the data is reproduced.

To prevent data from becoming impossible to reproduce even when an ID is not detected.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram of a reproduction system to which the present invention is applied. In FIG. 1, 1 is an optical head that reads data from an optical disk, 2 is a circuit that converts the read analog signal into a digital signal, and 3 is an SM detection circuit that detects an SM that is the starting point of an information recording unit. , 4 is a counter section 41
and an SM interpolation signal generation circuit including an interpolation signal generation unit 42,
Reference numeral 5 denotes an ID section/data section recording/reproduction method switching signal generation circuit, 6 an ID section continuous signal reproducing circuit, 7 a data section continuous signal reproducing circuit, and 8 a reproduction signal sending section (recording/reproduction method switching section). be.

FIG. 2 shows a timing chart of the sector format 100 and the ID section/data section recording/reproduction method switching signal 105.

As mentioned in the section on the prior art, an SM preformatted onto an optical disk.

The ID section has a row of holes (pits) formed on the recording film, whereas the data section, which records user data,
Data is recorded by changing the magnetization direction of the recording film.

When reproducing recorded data, a part of the signal 101 read out from the optical head 1 is converted into a digitized signal 102 by the analog waveform digital signal conversion circuit 2, and then converted into a digitized signal 102.
It is applied to the M detection circuit 3. By the SM detection circuit 3,
An SM serving as a starting point of an information recording unit is detected from the signal 102 and outputted as an SM detection signal 103 (FIG. 2(C)). Upon receiving the SM detection signal 103, the ID section/data section recording/reproduction method switching signal generation circuit 5 outputs the detection signal 10.
3, a switching signal 105 (FIG. 2(b)) for switching between the ID section and the data section of the existing signal is created and output. This signal is outputted as a reproduction signal 108 via the ID section successive signal sending section 8.

As described above, if the SM, which is the starting point of the information recording unit, is not detected, the reference point for creating the signal 105 for switching between the ID section and the data section becomes unclear, and data may not be reproduced.

Therefore, in order to prevent this, as a feature of this embodiment,
An SM interpolation signal generation circuit 4 is provided. The counter unit 41 of the generation circuit 4 predicts the position of the SM double signal to be determined next based on a certain SM detection signal, and also calculates the SM signal at this position.
It operates as a kind of timer and gate signal circuit that determines whether or not a double signal is detected. In this example, the counter section 41 is reset by the SM detection signal 103, counts the clock, and is set immediately before the next expected SM double signal position, and even if the next SM double signal is not detected, It is designed to be reset when counting up to just after that position.

Therefore, the counter 41 generates the SM detection expected gate signal 106 shown in FIG. 2(e). Interpolation signal creation unit 42
receives the signal 106 and produces no output when the SM detection signal 103 is detected, but when the SM detection signal 103 is not detected at the expected position, it outputs the interpolated signal 104 shown in FIG. 2(d). This is a type of gate circuit that occurs immediately after the scheduled position. The interpolation signal 104 is applied to the ID/data switching signal generation circuit 5, which generates the ID/data switching signal 1 at a timing corresponding to the data range of the next sector.
05 is generated. The switching signal 105 is applied to the reproduction signal 8, and the ID and user data are alternately selected and output.

According to this embodiment, the data portion can be reproduced satisfactorily even when no SM is detected.

In the above embodiment, the explanation was given regarding data reproduction.
The same can be applied when recording data.

〔Effect of the invention〕

As described in detail above, according to the data recording/reproduction control method of the present invention, when a sector mark is not detected, an interpolation signal is created in place of the sector mark, and a switching signal is created using this interpolation signal.
Since the D section and user data section are switched, even when no sector mark is detected, it is possible to reliably switch between the recording and playback formats of the ID section and the user data section, resulting in stable playback data. It has excellent effects, such as being able to obtain

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a reproduction system which is an embodiment of the present invention.
FIG. 2 is a timing chart of the sector format and the ID section/data section recording/reproducing method switching signal. DESCRIPTION OF SYMBOLS 1... Optical head, 2... Read signal digitization section, 3... SM detection circuit, 4...
...SM interpolation signal generation circuit, 5...ID section/
Data section recording/reproducing method switching signal generation circuit, 6...
- ID section read signal reproducing circuit, 7... data section read signal reproducing circuit, 8... reproduced signal sending section.

Claims (1)

[Claims] 1. A detection means for detecting a sector mark indicating the starting point of each sector of a recording medium and a sector identification signal preformatted to the sector, and a sector identification signal section and user data recording based on the sector mark detected by the detection means. In an optical data recording and reproducing control system, the optical data recording and reproducing control system includes a switching signal generating means for generating a switching signal for switching a recording and reproducing method for a sector, and a switching means for switching the recording and reproducing means to a corresponding method based on the switching signal. A data recording/reproducing control system comprising: interpolation signal generation means for generating an interpolation signal in place of the sector mark when no mark is detected, and configured to generate the switching signal using the interpolation signal.