JP2612587B2 - Information recording and playback method - Google Patents

Description

The present invention relates to an information recording / reproducing method, and more particularly to an information recording / reproducing method using an erasable information recording medium.

<Prior Art> In an information recording apparatus using a non-erasable information recording medium, to avoid overwriting on the information recording medium and to improve the throughput of the apparatus, the recorded sectors on the information recording medium are There has been proposed a method of recording a mark indicating the completion of writing (Japanese Patent Laid-Open No. 62-67731).

This is because the recording of the write mark and the subsequent information are performed continuously, the amount of reflected light from the medium is detected during the recording of the write mark, and if the write mark is detected, the subsequent information is recorded. By preventing recording, destruction of recorded information is prevented. Even if writing (overwriting) is performed again in a place where the writing mark has been recorded, the writing mark has an erase pattern of continuously irradiating light so that the writing mark is not destroyed.

<Problems to be Solved by the Invention> Therefore, in the above-described conventional example, the detection and recording of the presence / absence of a write mark are performed by one rotation of the disk, and the information is subsequently recorded. Has the effect of improving the throughput, but at the time of reproduction, the current position cannot be confirmed unless the data following the written mark is reproduced. Therefore, the meaning of the written mark does not exist in improving the seek speed at the time of reproduction. There was a problem.

The present invention has been made in view of such a problem, and in a method of describing a written mark, it is possible to shorten a seek time, enable high-speed access, and improve the reliability of information recording. An object of the present invention is to provide an information recording / reproducing method.

<Means for Solving the Problems> In order to achieve the above object, an information recording / reproducing method according to the present invention provides a code indicating that recording is performed including address information consistent with a recorded block of an information recording medium. (Hereinafter referred to as Z code) means for recording information with an error correction code added to a track on an information recording medium, and an error correction with a higher correction capability than the error correction code on the track. Recording the address information to which the code is added.

<Operation> Since the code indicating that recording has been performed contains consistent address information, the address of the current position can be immediately recognized simply by reproducing the code.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings. An optical card will be described as an example of the information recording medium used in the present invention.

First, the basic configuration of the optical card and the configuration of the optical head will be described. In the following description, the same members are denoted by the same reference numerals.

FIG. 1 is a schematic diagram of an embodiment of an information recording / reproducing apparatus according to the information recording / reproducing method of the present invention.

FIG. 2 is a schematic plan view of an example of the optical card used in the present invention.

 FIG. 3 is a partially enlarged view of part A in FIG.

In both figures, tracking tracks 5 (51, 52,...) Formed in a continuous linear form in advance on the optical card 1 are arranged at equal intervals. Then, a data recording unit 4 (4) for recording information for each tracking track.
1,42, ...) are provided. That is, the optical card 1 has a data recording section in all of the space between the tracking tracks.

As shown in FIG. 3, the tracking track 5-1 and
The G mark 7 is provided between the G mark 7 and the G mark 51. The G mark 7 is a mark for determining a reference track, and is arranged at a predetermined position on the optical card by preformatting. On the extension of the data recording section 40 having the G mark 7, a medium type identification pattern 8 as an auxiliary data section is recorded and formed in a free format or a light spot. The medium type identification pattern 8 indicates the type of the optical card, and records information such as a modulation / demodulation method, a data capacity per track, and the total number of tracks.

FIG. 4 is an explanatory diagram relating to the configuration of the optical head section of the information recording / reproducing apparatus.

FIG. 5 is an explanatory diagram showing a light beam irradiated on the optical card.

 FIG. 6 is an explanatory diagram showing the configuration of the photodetector.

A light beam emitted from a light source 27 such as a semiconductor laser is collimated by a collimator lens 28 and divided into three beams by a diffraction grating 30. These optical cards are imaged by the objective lens 26 on the tracking tracks 51, 52 and the data recording section 41 on the optical card 1, as shown in FIG. 5, to form beam spots S1, S2, S3. Here, the optical card 1 is moved in the direction of arrow R by driving means (not shown), and is scanned by the beam spot in the direction in which the tracking track extends. Beam spot S
The reflected lights of S1, S2 and S3 pass through the objective lens 26 again, are reflected by the beam splitter 20, and are projected by the condenser lens system 21 to the photodetectors 22, 23 and 24, respectively. Condensing lens system
Reference numeral 21 denotes an astigmatism system, which is an example arranged so that auto-focusing can be performed by a well-known astigmatism method. These photodetectors are configured in the arrangement shown in FIG. 6, and the photodetectors 23 are four in number, as in A, B, C, and D.
Has been split. In FIG. 4, reference numeral 29 denotes a prism for converting the cross-sectional distribution of the collimated light beam emitted from the semiconductor laser from an ellipse to a circle.
This is a mirror that guides the light beam to the mirror.

Next, the operation of recording information on an optical card using the above-described device will be described with reference to FIG.

First, when information is recorded in the data recording unit 41, the beam spots S1, S2, and S3 are irradiated on the tracking 52, the data recording unit 41, and the tracking track 51, respectively. These beam spots are scanned in the direction of arrow F by the movement of the optical card 1 as described above. The reflected light from the beam spot S1 enters the photodetector 22, and the reflected light from the beam spot S3 enters the photodetector 24, and a tracking signal is detected by a so-called three-beam method. That is, when the beam spots S1 and S3 deviate from the tracking tracks 52 and 51, a difference occurs in the light intensity incident on the photodetectors 22 and 24, and a tracking signal is obtained by comparing the signals from these light receiving surfaces. It is. Based on this tracking signal, tracking means (not shown, for example,
In the figure, the beam spots S1, S2, S3 are integrally moved in a direction perpendicular to the scanning direction (direction D in FIG. 2) by means for moving the objective lens 26 in the Z direction, and AT is performed.
Then, the data recording section 41 has a beam spot S2,
Accurate recording pit 3 along tracking tracks 51, 52
1 is recorded.

Next, an information recording / reproducing method according to the present embodiment will be described using an information recording / reproducing apparatus as an example.

The information recording / reproducing apparatus of this embodiment is characterized in that a special code (Z code) including the physical track number and indicating that the track is a recorded track is recorded on the extension of the information track before data recording. Things.

Hereinafter, a method of recording and reproducing information using the Z code and a method of recording the Z code will be described.

FIG. 7 is an explanatory diagram of the operation of recording and reproducing on an optical card by the information recording and reproducing apparatus of the present embodiment.

FIG. 8 is a flowchart for explaining the operation at the time of reproduction using the Z code.

FIG. 9 is a flowchart for explaining the operation at the time of recording using the Z code.

Hereinafter, the operation of reproducing information and the role of the Z code will be described with reference to FIG. 7 in accordance with the flow of FIG.

In FIG. 7, 1 is an optical card, 71d to 74d are recorded data, 71Z to 74Z are Z codes corresponding to the data, 700
710 are position coordinates on the optical card 1, for example, (7
00,705) to indicate point 70.

The light spot is located at the coordinates (700, 705) at the beginning or by a head feed mechanism (not shown), and the data of the target information track to be reproduced is data 74d.

First, the light spot moves from the coordinates (700, 705) to the coordinates (701, 705) as shown at 801 in FIG. Then, the code is reproduced from the coordinates (701, 705) (FIG. 80, FIG. 80).
2). The reproduction is completed when the coordinates (702, 705) are reached, and the physical track number (in FIG. 8, indicated as an address) of the information track where the current light spot is located can be known from this code. This is compared with the target physical track number (FIG. 80, FIG. 80).
3) In this example, the light spot is coordinated (704,706)
(FIG. 8A) and the same operation is repeated.

Thereafter, similarly, the Z codes 72Z, 73Z, 74Z are reproduced, and the Z code 74Z is reproduced, so that it is understood that the information track is the target information track.

Therefore, the moving direction of the light spot is reversed at the coordinates (700, 708), the light spot is moved toward the coordinates (704, 708), and the data 74d following the Z code 74Z is reproduced (FIG. 8).
804).

Since the Z code is added to all the written information tracks, a consistent address included in all the Z codes is a so-called physical address. Therefore, in this example, the host device, that is, the CPU 9, records and reproduces information using the physical address or the logical address obtained by converting the physical address.

Next, an information recording operation will be described with reference to FIG. 7 in accordance with the flow of FIG.

In FIG. 7, reference numeral 75d denotes data to be recorded from now on, and 75Z denotes a Z code to be recorded corresponding to the data 75d.

By the way, the light spot is set to the coordinates (700, 70
5) Next, the light spot is moved to the coordinates (704, 705) in the same manner as in the above-mentioned reproduction (No. 9).
(FIG. 901) The Z code is reproduced (FIG. 9, 902). It is determined from the physical track number included in the code whether the track is the target track (FIG. 903). In this case, the light spot is moved because it is different. Hereinafter, the same operation is repeated to reach the Z code 74Z of the target information track (the information track to be recorded has not been recorded because it is a recording operation. Therefore, the information track immediately before the information track is deleted. Target information track.)

Next, the light spot is moved to coordinates (700, 709) (FIG. 9).
04), and a Z code 75Z is recorded from the coordinates (701,709) (FIG. 9, 905).

Then, data 75d corresponding to the Z code 75Z is recorded from the coordinates (703,709). (FIG. 9 906) In addition to including information indicating no error and consistent address information, the Z code describes only consistent address information. The information may be indicated.

Since the number of bits required for recording the Z code is smaller than the number of bits for recording the corresponding data, the Z code has higher redundancy when redundant bits of the same length are respectively added. In this way, it is easy to make the redundancy of the Z code higher than that of the corresponding data, so that the probability of occurrence of an unrecoverable error of the Z code is lower than that of the corresponding data. Thus, effects such as an increase in the accuracy of information management can be obtained.

Further, when an error correction code is included in the Z code and the correction capability is made higher than that of the data corresponding to the Z code, it is possible to reduce the reproduction error of the Z code.

In this embodiment, the optical card is used as the information recording medium. However, it is obvious that the present invention can be applied to other information recording media such as a disk.

<Effect of the Invention> An information recording / reproducing method according to the present invention comprises the steps of: recording information with an error correction code added to a track on an information recording medium; and writing an error correction code having a higher correction capability than the error correction code on the track. Recording the address information to which the address is added, so that the accuracy of the address detection can be improved. As a result, the current position can be reliably recognized at the time of reproduction, and the management of the information corresponding to the address can be accurately performed. Can be done. Thus, the reliability of information recording can be improved.

In addition, since the redundancy of the code indicating no error and the correction capability of the error correction code are made higher than those of the corresponding data, the accuracy of information management is increased, and the reliability of information recording / reproducing system is improved. Has the effect of significantly improving the reliability of the device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the information recording / reproducing method of the present invention. FIG. 2 is a schematic plan view of an example of the optical card used in the present invention. FIG. 3 is a partially enlarged view of part A in FIG. FIG. 4 is an explanatory diagram relating to the configuration of the optical head unit in the information recording / reproducing method. FIG. 5 is an explanatory diagram showing a light beam irradiated on the optical card. FIG. 6 is an explanatory diagram showing the configuration of the photodetector. FIG. 7 is an explanatory diagram of the operation during recording and reproduction on an optical card by the information recording and reproduction method of the present invention. FIG. 8 is a flowchart for explaining the operation at the time of reproduction using the Z code. FIG. 9 is a flowchart for explaining the operation at the time of recording using the Z code. 1 ... optical card, 9 ... CPU, 10 ... MPU, 11 ... AT / AF
Control circuit, 12… Modulation / demodulation circuit, 13… Head feed motor, 14… Card feed motor, 15… AF actuator, 16… AT actuator, 17… Illumination optical system, 18…
… Optical pickup, 19 …… drive, 71d, 72d, 73d, 74d,
75d ... information, 71Z, 72Z, 73Z, 74Z, 75Z ... Z code.

Claims (1)

(57) [Claims] A step of recording information with an error correction code added to a track on an information recording medium; and a step of recording address information with an error correction code having a higher correction capability than the error correction code added to the track. An information recording / reproducing method, comprising: