JPH0415529B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] The present invention records binary data by irradiating a light beam such as a laser beam onto a rotating disk on which a thin metal film or the like is deposited on a disk surface such as a glass plate. The present invention relates to an optical storage device.

[Conventional technology and problems]

Many techniques have been reported for recording and reproducing binary data on a rotating disc-shaped disk on which a metal thin film is deposited using a needle-shaped light beam such as a laser beam. This type of technology uses a light beam to form dissolved micro-pits on the disc disk, and the micro-pit areas exhibit a specific state of weak reflectance, while the non-pit areas exhibit a specific state of strong reflectance. Become. Data is recorded by assigning binary states of binary data to these two types of states, a weak light beam is irradiated, and the data is reproduced depending on the strength and weakness of the reflected light. The pit portion recorded here has a diameter of 0.8 μm, for example, and a distance between adjacent tracks of 2 μm.

In addition, the diameter of the disc was set to 30 cm, and the distance between the tracks was
If it is about 2 μm, approximately 30,000 to 40,000 tracks can be divided. In such cases, a track servo device is used to cause the light beam to accurately follow the track to be recorded or reproduced. However, when recording data on a desired track, it involves difficult positioning problems. For example, suppose you install a new disk and record data to it. In this case, as one example, a reference track to serve as a reference is provided around the outermost part, innermost part, or center of the disk. However, when recording data, no matter how precisely the track servo device is physically adjusted with respect to one reference track, it is extremely difficult to maintain accurate distance intervals on tracks that are quite far from the reference track. It's difficult. Another method for this purpose is to provide a plurality of reference tracks and, for example, refer to the reference tracks to determine and record the desired track position. This method is
For example, "Unexamined Japanese Patent Publication No. 51-142933, Optical Memory Method"
seen in Such devices have the disadvantage of being complicated and expensive. Another method is to pre-provide very narrow grooves on all data tracks on which data are to be recorded. However, according to this method, it is very difficult to manufacture the groove. For example, the width of this groove is 0.6 μm.

The above situation also occurs during playback. That is,
This is because a data tractor does not necessarily have some data recorded on it, so it is necessary to determine a desired track from a reference track.

[Purpose and characteristics of the invention]

By the way, in an optical storage device that records binary data as optically distinguishable pits by irradiating a light beam such as a laser beam onto the disk surface, it is easy to distinguish between binary data indicating recorded information. It is necessary to record a mark that can be identified. This mark is used, for example, as a mark indicating the start or end of writing of recorded information.

An object of the present invention is to provide an optical storage device that records information as optically discernible pits on a disk surface, and is capable of recording marks that can be easily identified as recorded information pits. It is about providing.

In the present invention, in order to record such a mark, a recording pulse of a predetermined period is generated so as to connect a plurality of pits that have already been recorded, and a rectangular pit is created by continuously connecting the plurality of pits. It is characterized by the formation of Since this mark is formed as a long pit different from the data pit indicating recorded information, it can be easily distinguished from the data pit.

The present invention uses multiple tracks as data tracks. Note that this track may be arranged in a spiral manner. According to one feature of the present invention, minute pits are recorded in advance on the data track at equal intervals. That is, since the data tracks are provided with equally spaced pits, a desired data track can be easily tracked and controlled by the track servo device.
Here, the equally spaced pits may become narrower as they approach the radial center of the disk, or may be the same space over the entire surface. Here, the minute pit rows recorded in advance at equal intervals are assigned to binary states of binary data.

[Embodiments of the invention]

FIG. 1 is a block diagram illustrating an optical storage device showing one embodiment of the present invention. FIG. 2 is a diagram showing an example of a data track state of a disk on which data has not yet been recorded. Third
The figure is a waveform diagram illustrating an embodiment of an optical recording method related to an embodiment of the present invention.

In FIG. 1, a light source 1 is a laser emitter, and a light beam 20 is emitted. The light beam 20 is applied to the light modulator 2 and is transmitted from the controller 10 to the light modulator 2.
The beam is controlled by the recording pulse WP supplied to the recording pulse WP, and becomes a strong beam when the recording pulse WP is generated. The light beam 21 passes through the half mirror 3, is focused into a needle shape by the objective lens 4, and is projected onto the rotating recording/reproducing disk 5. The disk 5 used here is as shown in FIG. That is, according to FIG. 2, a large number of data tracks 3
A part of the disk 5 is shown in which minute pits (circular hatched areas) are formed at equal intervals at 0 and 31-.
This disk 5 has data tracks 30 and 31.
……have. Similar columns of pits such as spots 32 and 33 are formed on the data track 30. In the adjacent data track 31, pit rows such as pits 34 and 35 are similarly formed. Here, the size of the pit of the data track 30 is t, and the distance between the pits (for example, 32 and 3
3t) will be explained as 3t.

Incidentally, the pit 36 is a long pit indicating the beginning or end of writing.

In FIG. 1, the light beam 22 is a recording pulse
A pit is created at point 25 when the beam is strong due to the influence of WP. Here, the pits are recorded in such a way that the metal thin film is dissolved. Therefore, strong reflected light is generated from areas where there are no pits. This reflected light is reflected by the half mirror 3, becomes a light beam 23, and reaches the analyzer 6. On the other hand, only weak reflected light is generated from the part where the pit is made. As a result, the reproduced data is transmitted to the optical beam 23 by the analyzer 6.
It can be detected as the strength or weakness of

Incidentally, the pit portion formed at point 25 is usually formed between a row of pits made in advance, for example, between 32 and 33.

The detector 6 generates a readout signal 40 and the pulser 7
A portion of the signal is amplified by the sync signal generator 8, and a portion is sent to an external playback device (not shown), and a portion is input to the synchronization signal generator 8.

This synchronizing signal generator 8 has a sawtooth wave oscillator that oscillates in synchronization with the reproduction pulse 41.

This type of oscillator is, for example, of a type similar to that built into a part of the reading device of a magnetic tape device or a magnetic disk device. The output signal 42 of this synchronization signal generator 8 is also sent to an external playback device. Inside the synchronization signal generator 8, there is a self-oscillating sawtooth wave TH in synchronization with the reproduction pulse 41, and the sawtooth wave TH follows equidistant pits and is shown as TH in FIG. 3 in synchronization with the signal 40. The waveform will look like this.

Note that the signal TH has a waveform with twice the frequency of the signal 40. Therefore, the pits 70, 71, 72, . 41
controlled by.

The output signal RS of the synchronization signal generator 8 is generated at a position in the middle of the equally spaced pit row with twice the synchronization of this sawtooth wave (corresponding to the repetition period of the pits).

This signal will be created based on the sawtooth wave TH.

A signal RS output from the synchronization signal generator 8 is supplied to a controller 10 and a buffer 11.

The buffer 11 stores 16 "1" states and "0" states of binary data in the order of input, and sequentially stores "1" data W ₁ or "0" data in synchronization with the signal RS.
Outputs either W ₀ . Continuous detector 9 is “1”
From the signal W ₁ indicating data and the signal W ₀ indicating “0” data, the signal C is set to “high level” only when there is a change from “1” data to “0” data or from “0” data to “1” data. The voltage is applied to the controller 10 at a constant value. In the controller 10, the signal C is “high level”
At this time, the recording pulse WP is turned on for a short time with reference to other signals, and as a result, pits are written on the optical disk 5.

Assume now that binary data "110100" from the outside is stored in the buffer 11.

When the write control signal 43 is applied, this signal is applied to the controller 10 and the synchronization signal generator 8.

Upon receiving this signal, the synchronization signal generator 8 generates a signal.
Generate RS. This signal RS is sent to controller 10 and buffer 11.

The buffer 11 sends out "0" data W ₀ and "1" data W ₁ as shown in FIG. If the data is “110100”, it is “0” data W ₀ is pit 5
2, 54, 55, and "1" data _W1 is pits 50, 51, 53.

On the other hand, on track D of the disk, there are pits 70, 71, 72, 73, 74, 7, which are indicated with diagonal lines in advance.
As shown by 5, pits with a diameter of t are recorded at equal intervals of 3t.

During recording, these pits are assigned to respective pits of data. here,
It is assumed that pit 50 of "1" data _W1 is assigned to pit 70 of track D. Similarly, pits 53 are assigned to pits 73, respectively. The pit 52 of "0" data W ₀ is assigned to the pit 72 of track D. Pitt 54 becomes 74, Pitt 5
5 is assigned to 75 respectively. That is, the pit positions of each of the "1" data W ₁ and the "0" data W ₀ are made to correspond to equally spaced pits located at positions 2t away from them.

This association is performed by sending data from the buffer 11 to the continuous signal detector 9 and the controller 10 in synchronization with the signal RS. That is,
Data will be sent out in response to each pulse of signal RS that is advanced by 2t relative to pit D.

The writing of data is started by forming grooves that short-circuit between previously written pits, such as the pits 36 of the disk 5 (see FIG. 2), and connecting the pits.

That is, when the write control signal is applied to the terminal 43, the signal RS is first generated, 2t is sent from this signal RS, the recording pulse WP is generated for a predetermined period, the light beam is maintained as a strong beam, and a continuous A series of elongated pits is formed by short-circuiting a plurality of pits. This marks the beginning of writing.

When the writing start mark is formed, a predetermined data reading RD is sent from the controller 10 to the buffer 11.
In synchronization with the next RS signal, the first data is sent from the buffer 11, and in FIG.
0 and is sent to the continuous detector 9.

Here, if "1" data is assigned to the first pit, the first pit 50 is "1" data, so no recording pulse WP is generated and the light beam 22 remains a weak beam. Since the next data 51 is also "1", the light beam 22 remains a weak beam.

However, when the pit 52 is supplied to the continuous detector 9, since the pit 52 is "0", the continuous detector 9 detects this and generates the pulse signal C as a "high level" to the controller 10. supply to.

When the controller 10 receives the "high level" pulse signal C, it generates the recording pulse WP in synchronization with the signal RS, changing the light beam 22 from a weak beam to a strong beam.

As a result, a pit 63 (see FIG. 3) is formed on the track D.

Since the pits 50 and 51 of the "1" data _W1 continue to be in the same state, no new pits are recorded on the track D. Next, “0” data
Since the pit 52 of W ₀ changes from "1" to "0", the continuous detector 9 generates a pulse 56 as the signal C. This position is the “high level” of signal RS
It matches 80. Naturally, this pit 63 is recorded at an intermediate position between equally spaced pits 71 and 72, and has a diameter t and a spacing t on each side.

Next, when "1" is generated in the "1" data W ₁ as a pit 53, the data changes from "0" in the pit 52 to "1" in the pit 53, so a pulse 57 is generated as the signal C and the recording pulse WP A pulse is generated at 61, and a pit 64 is recorded on track D. This pit 64 corresponds to signal 81. Similarly, at pit 54 of "0" data W ₀ , pit 6 is
5 is recorded. At the pit 55 of the next "0" data _W0 , "0" continues, so no pit is recorded on track D.

By repeating the above process, a pit is recorded in the middle of the equally spaced pits on the data track, and this recording state indicates the inversion of the data.If there is no pit between the equally spaced pits, it is determined that the data is continuous. be done.

In this way, the predetermined data is written, and a write stop signal to finish writing the data is sent to the terminal 43.
As in the beginning of writing, a recording pulse WP is generated for a predetermined period of time, a groove is formed that shorts between the plurality of pits, a recording end mark of a long pit is formed, and data writing is completed. do.

In this embodiment, the explanation is given by assigning the first pit to "1" data, but if it is assigned to "0" data, a pit will be formed in front of the spot 70 in synchronization with the signal RS. becomes. Further, it is also possible to allocate a pre-formed pit to an intermediate position between pit information and handle it in the same manner as the magnetization reversal in the PM and FM methods in the magnetic recording method.

When supporting the MF and PM magnetic recording methods, the intermediate state between the first state (“0” or “1”) and the second state (“1” or “0”) of the pit information of binary data. 2. Make the positions correspond to the equally spaced pits, record pits between the equally spaced pits in the first state, and record no pits in the second state; When the first state or the second state of the digital data is continuous, a pit is recorded at the intermediate position of the equally spaced pits, and when the first state or the second state is reversed to another state, the pit is recorded at the intermediate position of the equally spaced pits. This can be achieved by not recording any pits at intermediate positions of equally spaced pits.

Although the writing start mark and the writing end mark are recorded using short-circuit spots, a predetermined pattern such as a mark such as "01010" may be recorded as the start of writing, and a predetermined pattern may be used as the end of writing. Note that if the number of data recording pit information is kept constant, the write end pattern and mark are unnecessary. In this case, when the recording pit is below a certain level, dummy pit information or the like may be inserted.

In the example given here, the recording pulse WP
The strong light beam is generated when the recording pulse WP is generated, but it may be changed so that the strong light beam is generated when the recording pulse WP is not generated. The light beam may also be modulated.

[Effects of the present invention]

According to the present invention, by irradiating the recording pulse,
By continuously connecting a plurality of pits that have already been recorded, a long pit different from a data pit indicating recorded information is formed, so a mark that can be easily identified as a recorded information pit can be recorded.

Further, the present invention can be similarly applied to transmission type optical disks and optical recording devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of an optical storage device to which the present invention is applied, and FIG. 2 is an explanatory diagram of an embodiment of a disk, which is one of the components of the invention.
FIG. 3 is a waveform diagram for explaining the operation of the embodiment. 1 is a light source, 2 is a light modulator, 3 is a half mirror,
4 is a lens, 5 is an optical disk, 6 is an analyzer, 7 is a pulser, 8 is a synchronizing signal generator, 9 is a continuous detector, 10 is a controller, and 11 is a buffer.

Claims (1)

[Scope of Claims] 1. In an optical storage device that records information as optically discernible pits on a disk surface, a recording pulse of a predetermined period is applied to combine a plurality of pits that have already been recorded. 1. An optical storage device characterized in that long pits are formed by continuously connecting the pits. 2. The optical storage device according to claim 1, wherein the recording pulse is a light beam having an intensity that dissolves a recording film on a disk surface.