JPH0648537B2 - Repeatable recordable information recording medium disk recording / reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is capable of erasing already recorded information, has a recording layer capable of repeatedly recording and reproducing information signals, and has a function of recording traces of main signals. The recording / reproducing operation at a constant linear velocity is performed in advance in a non-erasable manner by changing the geometrical shape. The three-point beam method is applied to the recording trace by the spiral tracking pilot signal. The present invention relates to a recording / reproducing apparatus for an information recording medium disk, which is performed under the tracking control operation to which the above-mentioned item is applied.

(Prior Art) In recent years, in various technical fields, as the demand for high density recording / reproducing of information signals has increased, high density recording / reproducing of information signals by various types of information recording media has been attempted. .

As an information recording medium in which information signals can be easily recorded and reproduced and the recorded information signals can be easily erased and re-recorded (rewritten), a ferromagnetic material has been conventionally used. A magnetic recording medium having a general structure provided with a recording layer made of a material was known, but recently,
As an information recording medium capable of recording, reproduction, and re-recording, a phase change from an amorphous state to a crystalline state or a crystalline state to an amorphous state by applying an electromagnetic wave, an electric field, heating, etc. Of a material that causes a phase change of, for example, an information recording medium in which a recording layer made of (TeOx) is formed on a substrate, or the magnetic properties for which thermomagnetic recording such as so-called Curie temperature recording or compensation temperature recording is performed. Thin film (e.g. magnetic thin film made of materials such as TbFe, GdTbFe, GdCo)
An information signal at a recording density higher than that of the recording / reproducing of the information signal, which is performed by using the conventional general magnetic recording medium, by using the information recording medium in which the recording layer is formed on the substrate. It has also been attempted to record and reproduce.

By the way, in order to satisfactorily perform high-density recording / reproducing of an information signal, a recording mark interval (track pitch) must be narrowed. However, when the track pitch is narrowed, a recording element, a reproducing element, or Since it is difficult to accurately track the recording / reproducing element on the recording trace on the information recording medium, attempts have been made to solve this problem by applying various tracking control means. However, when the recording density is further improved, an extremely high mechanical precision is required as the recording mechanism in order to prevent overlapping of the recording marks at the time of recording, which makes the device remarkably expensive. Becomes a problem.

As a means for solving the above-mentioned problems, in a disc type information recording medium (information recording medium disc) in which information signals are recorded and reproduced by using a minute spot of light, information recording has been conventionally performed. At the time of recording an information signal on the recording layer of the medium disk, at the time of reproducing the information signal from the recording layer, or a guide groove for generating a tracking reference signal used in a tracking control operation to be performed by both, It has been proposed to pre-configure the information recording medium disk in a non-erasable manner.

Further, for high density recording of an information signal on an information recording medium disk, it has been conventionally practiced to record and reproduce the information signal at a constant linear velocity (CLV).
In that case, a signal such as a rotation synchronizing signal (or speed control signal) for enabling the information recording medium disk to perform recording and reproduction at a constant linear velocity is used as a guide for generating the tracking reference signal. It has been conventionally proposed that the groove portion be fixedly recorded (non-erasable form) in advance, but in the conventional proposed information recording medium disk, an information signal for keeping the linear velocity constant is provided. Becomes a problem that it mixes with the main information signal to deteriorate the signal-to-noise ratio, and since improvement thereof has been desired, the applicant company has already recorded it as an information recording medium disk without the above-mentioned problems. Equipped with a recording layer that can erase information and can repeatedly record and reproduce information signals, the recording and reproducing operation at a constant linear velocity with respect to the recording trace of the main signal can change the geometric shape. Because It is designed to be performed under the control operation based on a reproduction signal from a recording trace by a spiral tracking pilot signal that is provided in advance in a non-erasable manner, and a lead-in signal area and a main A predetermined portion is recorded in the recording trace by the spiral pilot signal for tracking over all of the above-mentioned areas in the information recording medium disk in which the signal recording / reproducing area and the lead-out signal area are provided side by side. The rotation synchronization signal is included at every interval of the above, and further, the portion other than the lead-out signal area in the recording trace by the above-mentioned spiral pilot signal for tracking also includes the data of the accumulated time value. In addition, the lead-out in the recording trace by the pilot signal for spiral tracking described above is The signal area to provide an information recording medium disc which is made to include a lead-out signal, and to problems in the prior art already described is satisfactorily resolved.

(Problems to be Solved by the Invention) However, as described above, the information recording medium disk proposed by the applicant company has a lead-in signal area, a main signal recording / reproducing area, and a lead-out signal area on the surface of the disk. And are provided side by side, and the recording traces by the pilot signal for spiral tracking over all of the above-mentioned regions include rotation synchronization signals at predetermined intervals. Further, the portion other than the lead-out signal area in the recording trace by the above-mentioned spiral tracking pilot signal includes data of the cumulative time value. It is completely new that the lead-out signal area in the recording trace by the pilot signal contains the lead-out signal. Since the information recording medium disk is a rewritable information recording medium in a new form, when recording the information signal on the rewritable information recording medium disk, various information signals previously recorded in the recording trace by the pilot signal for tracking. There has been a demand for an information signal recording / reproducing apparatus capable of facilitating recording / reproducing operations by effectively utilizing the above.

(Means for Solving Problems) The present invention provides a recording layer capable of erasing recorded information of a recording trace of a main signal and capable of repeatedly recording and reproducing an information signal, For tracking, which is preliminarily provided in parallel with the recording trace of the main signal described above in a non-erasable manner due to a change in shape and includes at least a tracking information signal and a rotation synchronization signal. Using an information recording medium disk having a spiral recording trace by the pilot signal of, the recording / reproducing operation at a constant linear velocity with respect to the recording trace of the main signal is a tracking control operation using the three-point beam method. A recording / reproducing apparatus configured as described below, in which a three-point beam for tracking is arranged in a straight line diagonally crossing a recording trace of a main signal on a disk surface of an information recording medium. Of the three laser light spots generated in the state, the laser light in a state preceding the laser light spot used to record the information signal to be recorded in the recording trace of the main signal. A tracking pilot signal (tracking information signal, sync bit S, which is configured to include at least a tracking information signal and a rotation synchronization signal by a spot)
b, a rotation synchronization signal Sr, and a signal composed of one or more of the data St of the accumulated time value), means for reading out various information signals recorded in the recording trace, and The direction of the inclination of the straight line determined by the arrangement of the three light spots arranged in a straight line diagonally across the recorded trace of the main signal used for recording the information signal on the recorded trace of the main signal Means for causing the laser light spot preceding the laser light spot to be positioned closer to the area where the information signal is to be recorded, and a laser for generating the above-mentioned three laser light spots. (EN) A recording / reproducing apparatus for a repetitive recordable information recording medium disk, which is provided with means for making the intensity of light weaker in reproducing operation than in recording operation.

(Embodiment) Hereinafter, specific contents of a recording / reproducing apparatus for a repetitive recordable information recording medium disc of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a recording / reproducing apparatus for an information recording medium disk capable of repeating recording according to the present invention.

In FIG. 1, 5 is a motor for driving and rotating the information recording medium disc D, 6 is a rotation shaft of the motor, 7 is a turntable, and 8 is a clamper, and the information recording medium disc fixed to the turntable 7 by the clamper 8. D is driven by the motor 5 that is driven and rotated by the drive power supplied from the motor drive control circuit 9, and the information recording medium disk D is a recording (reproducing) surface thereof and a light beam generated by a laser beam for recording (reproducing). The relative velocity with respect to the spot is always rotated in such a state as to show a predetermined constant linear velocity.

The motor drive control circuit 9 described above uses the information recording medium disk D
In the following description, a recording trace by a pilot signal for tracking configured to include at least a tracking information signal and a rotation synchronization signal (in the following description, "tracking configured to include at least a tracking information signal and a rotation synchronization signal "Recorded trace by pilot signal for tracking" may be described as "recorded trace by pilot signal for tracking") By comparing the rotation synchronizing signal Sr read as described later from the inside with the reference signal Driving power is generated and supplied to the motor 5 so that the information recording medium disk D is driven and rotated at a rotation speed such that the obtained error signal becomes zero.

Reference numeral 10 denotes an optical recording / reproducing head, and the optical recording / reproducing head 10 is moved by a transfer mechanism 11 in the radial direction of the information recording medium disk D. Then, the transfer mechanism 11 moves the optical recording / reproducing head 10 in the direction and moving speed determined by the control signal supplied from the control unit 12 according to the operation mode set in the input unit 13 of the recording / reproducing apparatus. is there. In the controller 12, the transfer mechanism 11 described above is used.
In addition, the control signal required for each operation mode set by the input unit 13 is supplied to the motor drive control circuit 9 and other components.

The above-mentioned optical recording / reproducing head 10 includes a recording / reproducing laser driving circuit 10a, a recording / reproducing laser 10b, a collimating lens 10c,
10i, laser beam cross-section correction elements 10d and 10h, diffraction grating 10e, polarizing prism 10f, quarter wave plate 10g and 10
l, erasing laser 10j, erasing laser drive circuit 10k, dichroic mirror 10m, condenser lens 10n, cylindrical lens
10o, light receiving part 10p consisting of multiple light receiving elements, objective lens
10q, actuator 10r, etc.

14 is an input terminal of an information signal to be recorded, 15 is an encoder, 16 is a recording circuit, 17 is a reproducing circuit, 18 is a tracking control circuit, 19 is a focus control circuit, and 20 is an output terminal of a reproduction signal. .

When the operation mode of the recording / reproducing apparatus is set to the recording mode, the recording / reproducing laser 10b in the optical recording / reproducing head 10 and the laser light emitted from the recording / reproducing laser 10b have different wavelengths. When both the erasing laser 10j that emits the laser light and the erasing laser 10j are both in the light emitting state and the operation mode of the recording / reproducing apparatus is in the reproducing mode, the recording / reproducing head 10 Only the laser for laser 10b is turned on, and the laser for erasing 10j is turned off. The light emission output of the recording / reproducing laser 10b in the reproduction mode is controlled to be smaller than the light emission output of the recording / reproducing laser 10b in the recording mode.

In the state where the operation mode of the recording / reproducing apparatus is in the recording mode, the laser light emitted from the erasing laser 10j is the erasing laser 10j → the collimating lens 10i → the laser beam cross-section correcting element 10h → the polarizing prism 10f → 1 /
4 wave plate 10l → dichroic mirror 10m → 1/4 wave plate 10
l → Polarizing prism 10f → 1/4 wavelength plate 10g → Objective lens 10
q → Information recording medium disk D → Objective lens 10q → 1/4 wavelength plate
6g on the recording layer of the information recording medium disk D while passing through a path such as 10g → polarizing prism 10f → diffraction grating 10e → correction element 10d for laser beam cross-sectional shape → collimating lens 10c →. As indicated by Eb, a spot of a laser beam for erasing having a long cross-sectional shape is irradiated in the direction of extension of the recording mark, and a recording cross-section as indicated by reference numeral Lb2 in FIG. Prior to the recording of the information signal by the circular small-diameter laser beam spot, the recorded information in the main signal recording trace of the information recording medium disk D is erased (in order to avoid the complexity of illustration in FIG. 1). The display of the path of light reflected by the erasing laser beam from the information recording medium disc D is omitted, and as a constituent material of the recording layer in the information recording medium disc D, the magnetic material on which thermomagnetic recording should be performed. If the material is used, the laser light spot cross-sectional shape for erasing may be circular).

When the recording / reproducing apparatus is set to the recording mode according to the operation mode set in the input unit 13, the erasing laser drive circuit 10 of the optical recording / reproducing head 10 is transmitted from the control unit 12 via the line 26.
By the control signal supplied to k, the erasing laser 10j is made to emit light as described above, and the information recording medium disk D
At the same time that the preceding erasure of the already-recorded portion is performed favorably, at the same time, the recording / reproducing laser drive circuit 10a of the optical recording / reproducing head 10 from the control unit 12 via the line 27.
By the control signal supplied to the recording / reproducing laser 10b, the light emission output of the recording / reproducing laser 10b is increased so as to have an intensity necessary for recording.
The signal from the recording / reproducing laser 10b is supplied via the line 28.
The intensity of the laser beam emitted from the encoder 15 is modulated by the signal supplied from the encoder 15 to the recording / reproducing laser drive circuit 10a.

When the recording / reproducing apparatus is set to the recording mode according to the operation mode set in the input unit 13, the recording / reproducing laser 10
The laser light emitted from the laser beam b is recorded / reproduced laser 10b → collimator lens 10c → correction element 10d for laser beam cross-sectional shape.
→ By being given to the diffraction grating 10e through the path of the diffraction grating 10e, the laser beam of the 0th-order diffracted light (in the recording trace of the main signal of the information recording medium disk D, the information to be recorded is recorded in the diffraction grating 10e). (A laser beam that produces a recording light spot as indicated by Lb2 in FIG. 6 that is intensity-modulated by a signal) and a ± 1st-order diffracted laser beam (on the information recording medium disk D, as shown in FIG. A laser beam for producing a spot of light for tracking as indicated by Lb1 and Lb3 therein ... As will be apparent from the description below, the spot of light Lb1 on the disk D of the information recording medium is used for reading the pilot signal for tracking. Is also used) and a total of three laser beams are generated.

As described above, the three laser beams generated from the diffraction grating 10e are rotated in the direction of arrow R in FIG. 6 through the path of the polarizing prism 10f → 1/4 wavelength plate 10g → objective lens 10q. As shown in FIG. 6, three light spots Lb1, Lb2, Lb3 are generated on the recording surface of the information recording medium disc D, but the main signal recording trace of the information recording medium disc D is generated. The information signal to be recorded is recorded by a spot of a laser beam having a circular cross section for recording and having a small diameter, which is indicated by reference numeral Lb2 in FIG.
In the figure, two small-diameter laser beam spots having a circular cross section, which are denoted by reference characters Lb1 and Lb3, are located at the boundary between the recording trace of the pilot signal for tracking and the recording trace of the main signal. , Is used for generating a tracking reference signal, and for recording the information signal targeted for recording in the recording trace of the main signal in the two spots Lb1 and Lb3 of the small-diameter laser light described above. The laser light spot Lb1 preceding the laser light spot Lb2 used for the information signal recorded in the recording trace of the pilot signal for tracking (described later with reference to FIG. 5). It is also used for reading out various signals forming the signal section Sa).

The above-mentioned three light spots Lb1, Lb2, Lb3 are arranged in a straight line so as to diagonally cross the main signal recording trace, but are determined by the arrangement of the three light spots Lb1, Lb2, Lb3. A laser beam spot Lb1 preceding the laser beam spot Lb2 used for recording the information signal targeted for recording in the recording trace of the main signal in the direction of the inclination of the straight line as shown in FIG. However, if it is determined that it is located closer to the area where the information signal is to be recorded, the direction of the inclination of the straight line determined by the arrangement of the three light spots Lb1, Lb2, Lb3 is the above-mentioned direction. As compared with the case opposite to the above, the pilot signal can be read by the laser beam spot Lb1 with a good S / N when the information signal recording operation is first performed on the unrecorded information recording medium disk. . That is, the laser beam spot Lb1 preceding the laser beam spot Lb2 used for recording the information signal on the recording trace of the main signal is
If the information signal is to be positioned closer to the area where the information signal is to be recorded, it is assumed that the tracking is temporarily performed when the information signal recording operation is performed on a new unrecorded information recording medium disc. Even if the laser beam spot Lb1 is largely displaced toward the recording trace of the main signal in the unrecorded state due to the defective state of, the signal is not read from the recording trace of the main signal. When the laser beam spot Lb1 preceding the laser beam spot Lb2 used for recording the information signal is located closer to the area where the information signal has already been recorded, Compared with the state where the tracking state is poor and the laser beam spot Lb1 is largely displaced toward the recording trace of the main signal in the recording state, the reading of the pilot signal for tracking has a good S / N. Is the rope that may be.

As described above, the reflected light from the three laser light spots Lb1 to Lb3 generated on the information recording medium disk D by the three laser beams applied to the information recording medium disk D is the objective lens 10q → 1/4. After passing through the path of wave plate 10g → polarizing prism 10f → 1/4 wave plate 10l → dichroic mirror 10m → condenser lens 10n → cylindrical lens 10o, light is applied to a light receiving portion 10p composed of a plurality of light receiving elements.

In the light receiving section 10p, a tracking error signal obtained on the basis of the output signal of the light receiving element that photoelectrically converts the reflected light from the laser light spots Lb1 and Lb3 on the information recording medium disc D is tracked via the line 21. Information signals (various signals forming the signal section Sa described later with reference to FIG. 5) given to the signal obtained by photoelectrically converting the reflected light from the laser light spot Lb1 It is given to the recording circuit 16, the tracking control circuit 18, and the motor drive control circuit 9 via the line 22, and further, the laser beam spot Lb2
A focus error signal obtained from a signal obtained by photoelectrically converting the reflected light from the plurality of light receiving elements is given to the focus control circuit 19 via the line 23.

2 (a) and 2 (b) show a disk of an information recording medium disk on which a geometrical change due to a spiral tracking pilot signal is previously applied in a non-erasable manner. , A recording layer capable of recording, reproducing, erasing, re-recording (rewriting), and recording an information signal with a high recording density (eg, phase change from amorphous state to crystalline state) , Or a recording layer made of a material (TeOx) that causes a phase change from a crystalline state to an amorphous state, or a magnetic thin film on which so-called Curie point temperature recording or thermomagnetic recording such as compensation temperature recording should be performed. (For example, TbFe, GdTbF
e, a recording layer of a magnetic thin film) made of a substance such as GdCo}
The recording / reproducing operation at a constant linear velocity with respect to the recording trace of the main signal in the state of being applied is provided in advance in a non-erasable manner due to the change of the geometrical shape. 3 is a plan view of an information recording medium disk on which an information signal is to be recorded under a control operation based on a reproduction signal obtained from a recording trace of the pilot signal of FIG. Is the whole code of the information recording medium disk, 1 is the central hole, 2 is the lead-in signal area, 3 is the main signal recording / reproducing area, and 4 is the lead-out signal area.

In the information recording medium disc D shown in each of FIGS. 2A and 2B, one of the information recording medium discs D shown in FIG. On the inner circumference side of the information recording medium disk D, and the lead-out signal area 4
2 shows an example of a configuration in which each of them is provided on the outer peripheral side of the information recording medium disc D, and the information recording medium disc D shown in FIG. Is provided on the outer peripheral side of the information recording medium disc D, and the lead-out signal area 4 is provided on the inner peripheral side of the information recording medium disc D.

Then, in the above-mentioned information recording medium disc D, a recording trace by a spiral pilot signal for tracking which is provided in advance in a non-erasable manner due to a change in geometrical shape is the information recording medium disc D. Is provided over the entire area of the lead-in signal area 2, the main signal recording / reproducing area 3 and the lead-out signal area 4, and in the information recording medium disk D, the spiral tracking described above is provided. In order to make the crosstalk amount of the pilot signal crossing the recording trace of the main signal sandwiched between the recording traces of the pilot signal for use by the pilot signal for spiral tracking described above, Recording trace width Wp of the recording trace (Fig. 3 or 6
(See the figure) is the recording mark interval TP on the information recording medium disk D
It is set to be 40% or less of (see FIG. 3 or FIG. 6).

FIG. 4 shows that in the information recording medium disc D, the recording trace width Wp of the recording trace due to the spiral tracking pilot signal is set to 40% or less of the recording trace interval TP in the information recording medium disc D as described above. FIG. 6 is a diagram used for explaining the reason why it is desirable to set, where the recording trace width of a recording trace by a spiral tracking pilot signal is Wp, and the spiral tracking pilot signal is described above. With the recording trace width of the main signal recording trace sandwiched between the recording traces by Wm and the recording trace interval of the information recording medium disk D as TP = Wm + Wp, the diameter d of the recording / reproducing light spot is d. When the relation is ≤ Wm, the ratio W of the post-recording width Wp of the recording trace by the spiral tracking pilot signal and the recording trace interval TP of the information recording medium disk D
The figure shows how the crosstalk amount of the tracking pilot signal that crosstalks to the main signal changes with respect to the change of the p / TP value. When the value of Wp / TP is 0.4 or less, Experimental results show that the crosstalk effect of the tracking pilot signal on the main signal does not hinder the practical use.

3 and 6 are enlarged plan views of a part of the above-mentioned information recording medium disk D, and the portions shown by obliquely descending rightward lines in FIGS. 3 and 6 will be described later. Represents a pit portion or a groove portion preformed on the substrate in a non-erasable manner by changing the geometrical shape by the tracking pilot signal having the signal form as described above. In FIG. 3 and FIG. 6, the part shown by drawing a diagonal line to the left is a light spot. It should be noted that the portions other than the portion indicated by the diagonal lines to the right in FIGS. 3 and 6 are land portions.

FIG. 5 is a schematic diagram for explaining the signal form of the tracking pilot signal. In FIG. 5 (a), the tracking pilot signal is a block signal in units of a collection of specific signals one after another. In FIG. 5, (b) shows a concrete configuration example of a block signal of a unit in the pilot signal for tracking.

In the above-mentioned information recording medium disk D, a recording trace by a spiral pilot signal for tracking, which is previously provided in a non-erasable manner due to a change in geometrical shape, is recorded as described above. The entire area of the recording medium disk D,
That is, the lead-in signal area 2, the main signal recording / reproducing area 3, and the lead-out signal area 4 are provided over the entire area. There is no recording mark by the pilot signal of.

That is, in the above-described information recording medium disk D, all the signals to be recorded in the recording trace by the spiral tracking pilot signal which is previously provided in an unerasable manner by the change of the geometrical shape are A tracking information signal recorded in the form of a groove that is substantially continuous over the area, a rotation synchronization signal recorded at regular intervals over the entire area, and areas other than the lead-out signal area 4 (lead-in signal area 2 and In the information recording medium disk D, since it is the data of the accumulated time value recorded in both the main signal recording / reproducing area 3) and the lead-out signal (go-home signal) recorded in the lead-out signal area 4. The signals recorded in the recording traces of the spiral tracking pilot signal provided over all of the above-mentioned areas. But not all are as identical signal form for the entire region.

Of the unit used to form the pilot signal for tracking.
In (b), an example is shown in which the unit block signal is composed of the synchronization bit Sb, the rotation synchronization signal Sr, the accumulated time value data St, and the continuous signal section Sc. Also in the unit block signal of such a configuration mode, the unit block signal includes the continuous signal portion Sc and the other signal portion Sa (in the example of the signal configuration of FIG. 5B, the synchronization bit Sb, The rotation synchronizing signal Sr and the data St of the accumulated time value constitute the signal portion Sa}. The signal portion Sa comprises two signal portions Sa and Sc described above. The length L of the block signal of one unit is always constant in any part of the disc D of the information recording medium.

Two signal parts Sa and S that form a unit block signal
In c, the synchronization bit Sb in the signal section Sa is configured to represent a synchronization code by a predetermined plurality of bits, and the rotation synchronization signal Sr is, for example, an impulse having a predetermined pulse width. , The cumulative time value data St is set at the boundary of transition from the lead-in signal area 2 to the main signal recording / reproducing area 3 as a reference time position of the cumulative time 0, and from the reference time position to the main signal recording / reproducing area 3 side. Is set to a numerical signal indicating a positive cumulative time value, and is set to a numerical signal indicating a negative cumulative time value on the lead-in signal area 2 side from the reference time position. (Details of the contents of the recording signal in the lead-in signal area 2 will be described later with reference to FIG. 7).

The synchronization bit Sb, the rotation synchronization signal Sr, the accumulated time value data St, and the like are recorded as pits corresponding to the above signals on the surface of the substrate of the information recording medium disk D, while the unit The continuous signal portion Sc in the two signal portions Sa and Sc constituting the block signal of is recorded on the surface of the substrate of the information recording medium disk D as a continuous long groove.

As described above, on the surface of the substrate of the information recording medium disk D on which the recording trace by the tracking pilot signal is recorded by the pits and the long groove corresponding to the tracking pilot signal composed of the two signal cormorants Sa and Sc. , Record,
A recording layer capable of reproducing, erasing, re-recording (re-writing), and recording an information signal at a high recording density (for example, a phase change from an amorphous state to a crystalline state, or a crystalline state to an amorphous state) Recording layer made of a material (TeOx) that undergoes a phase change to, or a magnetic thin film (such as TbFe, GdTbTe, and GdCo) on which thermomagnetic recording such as so-called Curie point temperature recording and compensation temperature recording should be performed. Information recording medium disk D
Is done.

The recording trace by the pilot signal for tracking shown in FIG. 3 is a portion composed of pits by the above-mentioned signal portion Sa, and in FIG.
The portion of the recording mark by the pilot signal for tracking, which is composed of both the pits and the long groove by the continuous signal portion Sc, is shown.

FIG. 7 is a diagram used for explaining the content of the signal in the recording trace by the pilot signal for tracking in the lead-in signal area 2. In FIG. 7, 3 is a main signal recording / reproducing area, 2a and 2b are lead areas. A code for distinguishing the two areas in the IN signal area 2, 0 is a code indicating the boundary between the lead-in signal area 2 and the main signal recording / reproducing area 3, and the thin vertical line in the drawing indicates the extension of the recording trace. It is the line shown in the direction.

In FIG. 7, recording marks by the pilot signal for tracking in the area 2a of the lead-in signal area 2,
The tracking pilot signals recorded in the recording traces by the tracking pilot signals in the area 2b of the lead-in signal area 2 have different signal forms.

That is, in the tracking pilot signal composed of two signal portions, the signal portion Sa and the continuous signal portion Sc, the signal Sa rotates as the tracking pilot signal recorded in the area 2a of the lead-in signal area 2. A signal composed of only the synchronization signal Sr is used, and as the pilot signal for tracking recorded in the area 2b of the lead-in signal area 2, the signal portion Sa has the synchronization bit Sb and the rotation synchronization signal Sr. And the position of the boundary between the area 2a and the area 2b is used as a start portion for rewriting the lead-in information.

Now, when the input information for setting the recording / reproducing apparatus to the recording mode is given to the input unit 13, each component of the recording / reproducing apparatus in the control unit 12 sequentially performs the operation required in the recording mode. Generate a control signal that
It is supplied to each component of the recording / reproducing apparatus, and the recording operation is performed by the recording / reproducing apparatus.

When the recording / reproducing apparatus is set to the recording mode, a control signal generated by the control unit 12 is supplied to the transfer mechanism 11 via the line 30, so that the transfer mechanism 11 causes the optical recording / reproducing head 10 to move.
From the home position to a position where the laser light spots Eb, Lb1 to Lb3 can be located in the area 2a of the lead-in signal area 2 on the information recording medium disk D, and then the laser light spot Eb. , Lb1 to Lb3 are moved in such a manner that the optical recording / reproducing head 10 is moved such that the lead-in signal area 2 of the information recording medium disk D is sequentially moved to the area 2b → the main signal recording / reproducing area 3. To During the period when the recording mode is started and the laser light spots Eb and Lb1 to Lb3 are positioned in the lead-in signal area 2 of the information recording medium disc D, the recording / reproducing apparatus temporarily reproduces. Be put in a state. The lead-in area 2 is divided into an area 2a and an area 2b, and the recording trace by the pilot signal for tracking of each of the areas 2a and 2b is divided into a signal portion Sa and a continuous signal portion Sc used for the construction thereof. As described above, the configuration of the signal portion Sa of the tracking pilot signal composed of two signal portions is configured by different tracking pilot signals, and the tracking pilot in the area 2a is described above. The signal portion Sa of the signal is composed only of the rotation synchronizing signal Sr, and the signal portion Sa of the pilot signal for tracking in the area 2b is composed of the synchronization bit Sb, the rotation synchronizing signal Sr, and the accumulated time value data St. It is configured.

In the recording trace of the main signal sandwiched by the recording traces by the tracking pilot signal in the area 2b of the lead-in area 2, as will be described later in detail, at the end of the previous recording operation, The laser light spot used to record the information signal on the recording trace of the main signal, such as the chapter number corresponding to the recorded contents during the recording operation and the data of the accumulated time value corresponding to the recording area. Recorded by Lb2.

The lead-in signal based on the data such as the chapter number and the accumulated time value recorded in the recording trace of the main signal in the area 2b of the lead-in area 2 is temporarily reproduced by the recording / reproducing apparatus as described above. Is read out and stored in the memory of the control unit 12 via the reproduction circuit 17. In addition, the control unit 12 uses the data of the accumulated time value read as described above to read the main signal recording / reproducing area 3
In order to position the laser beam spots Eb, Lb1 to Lb3 at the recording start portion following the recorded portion in the above, the transfer unit transmits the control signal for moving the optical recording / reproducing head 10 rapidly.
Give to 11.

The recording / reproducing apparatus is set to the recording mode, and the optical recording / reproducing head 10 is moved from the home position to the area 2a of the lead-in signal area 2 on the information recording medium disk D.
In a state where the laser light spots Eb and Lb1 to Lb3 can be positioned, the pilot signal read from the recording trace by the pilot signal for tracking from the area 2a of the information recording medium disk D is already stored. As described above, recording is performed by the pilot signal for tracking which is composed of two signal portions, the signal portion Sa and the continuous signal portion Sc, and which exists in the area 2a of the lead-in signal area 2 in the disc D of the information recording medium. Since the pilot signal recorded in the trace has a signal form in which the signal portion Sa thereof is composed only of the rotation synchronization signal Sr, the area 2a of the lead-in signal area 2 in the information recording medium disk D is as described above. In the state where the laser beam spots Eb and Lb1 to Lb3 are located inside, it is a recording mark by the pilot signal for tracking. The rotation synchronization signal Sr is read out by the laser beam spot Lb1.

When the recording / reproducing apparatus is set to the recording mode, the motor drive control circuit 9 supplied with the control signal from the control unit 12 through the line 31 causes the motor 5 to rotate at a rotation speed of a predetermined initial value. Rotation control. For that purpose, first, the lead-in signal area 2 in the disk D of the information recording medium is
When the laser light spots Lb1 to Lb3 are positioned in the area 2a, and the rotation synchronization signal Sr is read by the laser light spot Lb1, the light receiving unit 10p supplies the rotation synchronization signal Sr to the motor drive control circuit 9. As a result, the motor drive control circuit 9 compares the rotation synchronization signal Sr supplied thereto with the reference signal, and the rotation synchronization signal Sr read by the laser beam spot Lb1 is kept constant in the cycle of the motor 5. The rotation speed is controlled so that the relative linear velocity between the laser beam spot and the information recording medium disk D is always kept at a predetermined constant velocity.

As described above, if the signal portion Sa of the tracking pilot signal recorded in the area 2a of the lead-in signal area 2 is composed of only the rotation synchronization signal Sr, the lead-in signal is used. Area 2 of signal area 2
Since the signal read out by the laser light spot Lb1 from the signal portion Sa in the tracking pilot signal recorded in a is only the impulse-shaped rotation synchronization signal Sr, the laser light spot Lb1 causes the signal in the lead-in signal area 2 to be read. By comparing the impulse-shaped rotation synchronization signal Sr read from the area 2a with the reference signal in the motor drive control circuit 9, the cycle of the rotation synchronization signal Sr read by the laser light spot Lb1 is always constant. As described above, the rotation speed of the motor 5 is well controlled, and the relative linear velocity between the laser light spot and the information recording medium disk D is quickly raised to a predetermined constant velocity.

The optical recording / reproducing head 10 is transferred by the transfer mechanism 11, and the position of the laser beam spot is a region beyond the lead-in start portion of the boundary between the regions 2a and 2b of the lead-in signal region 2 in the information recording medium disk D. When moving to the area 2b, the signal portion Sa in the pilot signal read from the recording trace of the tracking pilot signal in the area 2b is, as described above, the synchronization bit Sb, the rotation synchronization signal Sr, and the negative cumulative time value. Data St and
The rotation synchronization signal Sr is supplied to the motor drive control circuit 9 to be used for controlling the rotation speed of the motor 5, and the negative cumulative time value data St is used by the control unit 12 to generate a control signal. The sync bit Sb is also used as a timing reference for the processing of data, as is well known.

In addition, all the main signal recording traces of the area 2b in the lead-in signal area 2 include the chapter number corresponding to the recorded contents recorded at the end of the previous recording operation and the cumulative time value corresponding to the recording area. Since data and the like are recorded, the optical recording / reproducing head 10 is moved by the transfer mechanism 11, and the position of the laser beam spot moves in the area 2b of the lead-in signal area 2 in the disk D of the information recording medium. At this time, from the main signal recording trace in the area 2b, a lead-in signal composed of a chapter number corresponding to the recorded content at the end of the previous recording operation and data of a cumulative time value corresponding to the recording area is read. It is then supplied to the control unit 12 via the reproduction circuit 17 and stored in the memory.

The control unit 12 uses the data of the cumulative time value corresponding to the recording area at the time of the previous recording operation, and the main signal recording / reproducing area on the information recording medium disk D at which the recording of the signal should be started at the current recording operation. The optical recording / reproducing head 10 is moved by the transfer mechanism 11 so that the laser beam spot is located at the position 3, and then the optical recording / reproducing head 10 is put in the standby state at that position (of the previous recording). In the last part, the lead-out signal is recorded after the data of the cumulative time value is recorded over several tracks as will be described later. It is made part.)

During the recording operation on the information recording medium disk D having no recorded information, the lead-in signal is not read from the main signal recording trace of the area 2b of the lead-in signal area 2. Indicates a predetermined value, for example, the optical recording / reproducing head 10 is made to stand by so that the laser light spot is positioned at a position where the accumulated time value data is -2 seconds.

After the recording by the recording / reproducing apparatus is started, the optical recording / reproducing head 10 is transmitted from the control unit 12 via the line 26.
The erasing laser (semiconductor laser) 10j is made to emit light by the control signal given to the erasing laser driving circuit 10k, and the recording / reproducing laser in the optical recording / reproducing head 10 from the control section 12 via the line 27. The recording / reproducing laser (semiconductor laser) 10b is brought into a light emitting state having a light intensity required in the recording mode by a control signal given to the drive circuit 10a.

The recording / reproducing laser 10b emits a laser light beam whose intensity is modulated by a signal supplied from the recording / reproducing laser driving circuit 10a for driving the recording / reproducing laser 10b.
The signal used for performing the intensity modulation of 10b is the signal given from the encoder 15 to the recording / reproducing laser drive circuit 10a as described above.

In the encoder 15, of the signal to be recorded supplied from the input terminal 14 thereof and the signal read from the recording trace by the pilot signal for tracking of the main signal recording / reproducing area 3 in the information recording medium disk D. Of the accumulated time value St and the chapter number input from the input unit 13 to generate a recording signal in a coded state, and apply the recording signal to the recording / reproducing laser drive circuit 10a in the optical recording / reproducing head 10. Of.

When the laser beam spot moves from the main signal recording / reproducing area 3 to the lead-out signal area 4 during the recording operation, the lead-out signal is read from the recording trace by the pilot signal for tracking in the lead-out signal area 4. In this case, the recording circuit 16 gives a read-out signal to the encoder 15 and the control unit 12 so that the control unit 12 supplies only the read-out signal from the encoder 15 to the recording / reproducing laser drive circuit 10a. , The operation mode of the encoder 15 is controlled so that the lead-out signal is recorded, and then the transfer mechanism 11 is controlled so that the optical recording / reproducing head 10 rapidly returns to the area 2a of the lead-in signal area 2. Next, the data of each chapter number and cumulative time value corresponding to all the recorded contents recorded on the disc D of the information recording medium is the lead-in signal area. The recording circuit 16, the encoder 15, the optical recording / reproducing head 10 and the like are controlled so that the recording is performed in the area 2b, and after the above-mentioned operations are completed, the optical recording / reproducing head 10 is moved to the home position. Return to the position and stop.

Further, when a lead-out signal is given from the input unit 13 to the control unit 12 in order to end the recording operation for the main signal recording / reproduction region 3 in the middle of the main signal recording / reproduction region 3, the control unit 12 causes the recording circuit 16, the encoder. 15. The optical recording / reproducing head 10 and the like perform control operations for the respective parts of the apparatus so as to perform the following operations at the end of the recording operation.

When an instruction to end the recording operation is given to the main signal recording / reproducing area 3 in the middle of the main signal recording / reproducing area 3, only the data of the accumulated time value is recorded for a period of several rotations from that point, and then the lead-out signal is outputted. , And then the optical recording / reproducing head 10 is rapidly returned to the area 2a of the lead-in signal area 2, and next, all the recorded contents corresponding to the information recorded on the information recording medium disk D are recorded. After recording the lead-in signal including the data of the chapter number and the accumulated time value in the entire area 2b of the lead-in signal area 2, the optical recording / reproducing head 10 is returned to the home position and the apparatus is stopped. It is.

As described above, when the optical recording / reproducing head 10 is rapidly returned to the area 2a of the lead-in signal area 2, the recording / reproducing laser and the erasing laser are both inoperative.
During the recording operation described above, the tracking control circuit 18
The actuator 10r supplied with the output signal from the focus control circuit 19 drives and controls the objective lens 10q so that the recording operation is always performed in a good tracking state and a focus state. This also applies to the reproducing operation.

When the input information for setting the recording / reproducing apparatus to the reproducing mode is given to the input unit 13, each component of the recording / reproducing apparatus in the control unit 12 sequentially performs the operation required in the reproducing mode. Generate a control signal that
It is supplied to each component of the recording / reproducing apparatus, and the reproducing operation is performed by the recording / reproducing apparatus.

When the recording / reproducing device is set to the reproducing mode, the control signal generated by the control unit 12 is supplied to the transfer mechanism 11 via the line 30, so that the transfer mechanism 11 causes the optical recording / reproducing head 10 to move.
Is moved from the home position to a position where the laser light spots Lb1 to Lb3 can be located in the area 2a of the lead-in signal area 2 on the disc D of the information recording medium.

Then, the recording / reproducing apparatus is set to the reproducing mode, and the optical recording / reproducing head 10 moves from the home position to the area 2 of the lead-in signal area 2 on the information recording medium disk D.
In the state where the laser light spots Lb1 to Lb3 can be positioned in a, the information recording medium disk D
As described above, the pilot signal read from the recording trace of the tracking pilot signal from the area 2a in FIG. 2 is composed of two signal portions, the signal portion Sa and the continuous signal portion Sc. The pilot signal recorded in the recording trace of the tracking pilot signal existing in the area 2a of the lead-in signal area 2 on the medium disk D has a signal form in which the signal portion Sa of the pilot signal is composed only of the rotation synchronization signal Sr. Because it belongs to
As described above, in the area 2a of the lead-in signal area 2 on the disc D of the information recording medium, laser beam spots Lb1 to Lb3 are formed.
In the state where is positioned, the rotation synchronizing signal Sr is read by the laser beam spot Lb1 from the recording trace by the pilot signal for tracking. The motor drive control circuit 9 supplied with the control signal via the rotation control circuit controls the rotation of the motor 5 so as to rotate the motor 5 at a rotation speed of a predetermined initial value. Then, the laser light spots Lb1 to Lb3 are placed in the area 2a of the lead-in signal area 2 on the information recording medium disk D, and the rotation synchronization signal Sr is generated by the laser light spot Lb1.
Is read, the motor drive control circuit 9 from the light receiving unit 10p is read.
Is supplied to the motor drive control circuit 9, the rotation synchronization signal Sr supplied thereto is compared with the reference signal, and the cycle of the rotation synchronization signal Sr read by the laser beam spot Lb1 is always constant. In this way, the rotation speed of the motor 5 is controlled so that the relative linear velocity between the laser beam spot and the information recording medium disk D is always kept at a predetermined constant velocity.

The optical recording / reproducing head 10 is transferred by the transfer mechanism 11, and the position of the laser beam spot is a region beyond the lead-in start portion of the boundary between the regions 2a and 2b of the lead-in signal recording 2 on the information recording medium disk D. When moving to the area 2b, the signal portion Sa in the pilot signal read from the recording trace of the tracking pilot signal in the area 2b is, as described above, the synchronization bit Sb, the rotation synchronization signal Sr, and the negative cumulative time value. Data St and
The rotation synchronization signal Sr is supplied to the motor drive control circuit 9 to be used for controlling the rotation speed of the motor 5, and the negative cumulative time value data St is used by the control unit 12 to generate a control signal. The sync bit Sb is also used as a timing reference for the processing of data, as is well known.

Further, in all of the main signal recording traces of the area 2b in the lead-in signal area 2, the data of the chapter number corresponding to the recorded contents recorded on the information recording medium disk D and the accumulated time value corresponding to the recording area are recorded. , Etc. are recorded, the optical recording / reproducing head 10 is moved by the transfer mechanism 11, and the position of the laser beam spot is changed to the information recording medium disk D.
When moving in the area 2b of the lead-in signal area 2 in, the main signal recording trace in the area 2b shows the chapter contents corresponding to the area contents of the information recording medium disk D and the accumulated time value corresponding to the recording area. The data and the like are read out and supplied to the control unit 12 via the reproduction circuit 17 and stored in the memory.

In the control unit 12, the data of the cumulative time value corresponding to the recorded contents of the information recording medium disk D and the data of the cumulative time value indicating the position of the information of the chapter number of the reproduction desired input to the input unit 13 are mainly used. The transfer unit transmits a control signal for rapidly moving the optical recording / reproducing head 10 so that the laser light spots Lb1 to Lb3 can be positioned at the head position of the recording portion of the information of the desired chapter number in the signal recording / reproducing area 3.
Give to 11.

When the recording / reproducing apparatus is set to the reproducing mode according to the operation mode set in the input unit 13, the erasing laser drive circuit 10 of the optical recording / reproducing head 10 is transmitted from the control unit 12 via the line 26.
The control signal supplied to k stops the emission of the erasing laser 10j, and at the same time, controls the recording / reproducing laser drive circuit 10a of the optical recording / reproducing head 10 via the line 27 from the control unit 12. The signal causes the light emission output of the recording / reproducing laser 10b to have a constant and small intensity necessary for reproduction.
In playback mode, encoder 15 is
A control signal provided via 29 causes the encoder 15
The output signal of is not supplied to the recording / reproducing laser drive circuit 10a.

The laser light emitted from the recording / reproducing laser 10b in the reproducing mode is similar to the operation of the recording / reproducing apparatus in the recording mode described above, and the recording / reproducing laser 10b → collimator lens 10c → correction element 10d for the laser beam cross-sectional shape → By being given to the diffraction grating 10e through the path of the diffraction grating 10e, the diffraction grating 10e
At e, a laser beam of 0th-order diffracted light (a laser beam for producing a reproduction light spot as indicated by Lb2 in FIG. 6 on the information recording medium disk D) and a laser of ± 1st-order diffracted light Beam (on the information recording medium disk D, Lb1,
And a laser beam for generating a spot of light for tracking as indicated by Lb3), a total of three laser beams are generated.

As described above, the three laser beams generated from the diffraction grating 10e are rotated in the direction of arrow R in FIG. 6 through the path of the polarizing prism 10f → 1/4 wavelength plate 10g → objective lens 10q. As shown in FIG. 6, three light spots Lb1, Lb2, Lb3 are generated on the recording surface of the information recording medium disc D, but the main signal recording trace of the information recording medium disc D is generated. Is continuously irradiated with a small-diameter laser beam spot having a circular cross-section for reproduction, which is indicated by reference numeral Lb2 in FIG. 6, and an information signal is read from a recorded trace of the main signal. Two small-diameter laser light spots having a circular cross section, which are denoted by reference characters Lb1 and Lb3 in FIG. 6, are positioned at the boundary between the recording trace of the pilot signal for tracking and the recording trace of the main signal. Is used to generate the tracking reference signal. .

As described above, the reflected light from the three laser light spots Lb1 to Lb3 generated on the information recording medium disk D by the three laser beams applied to the information recording medium disk D is the objective lens 10q → 1/4. Wave plate 10g → Polarizing prism 10f → 1/4 Wave plate 10l → Dichroic mirror 10m → Condenser lens 10n →
After passing through the path of the cylindrical lens 10o, the light is applied to the light receiving portion 10p including a plurality of light receiving elements.

In the light receiving section 10p, a tracking error signal obtained on the basis of the output signal of the light receiving element that photoelectrically converts the reflected light from the laser light spots Lb1 and Lb3 on the information recording medium disc D is tracked via the line 21. 18, a focus error signal obtained from a signal obtained by photoelectrically converting the reflected light from the laser beam spot Lb2 by a plurality of light receiving elements is given to the focus control circuit 19 via a line 23, and further, a main signal of Laser light spot L irradiating the recording trace
From the signal obtained by photoelectrically converting the reflected light of b2 by the light receiving element, the light receiving unit 10
The reproduction signal generated by p is output to the reproduction circuit 17 via the line 24, and the reproduction circuit 17 performs decoding and other predetermined signal processing, and outputs the reproduction signal to the output terminal 20.

When there are a plurality of information signals desired to be reproduced, it is possible to sequentially reproduce the information signals desired to be reproduced by previously inputting the chapter numbers corresponding to the plurality of information signals desired to be reproduced. it can. When the reproducing operation is completed, the optical recording / reproducing head 10 is returned to the home position and the apparatus is stopped.

(Advantages of the Invention) The recording / reproducing apparatus for a repetitive recordable information recording medium disc of the present invention has a recording layer capable of erasing recorded information of a recording trace of a main signal and repeatedly recording / reproducing an information signal. It is provided in advance in parallel with the recording trace of the main signal described above in a non-erasable manner by changing the geometrical shape, and at least a tracking information signal and a rotation synchronization signal are provided. By using an information recording medium disk having a spiral recording trace by a pilot signal for tracking which is configured to include a recording / reproducing operation at a constant linear velocity with respect to the recording trace of the main signal, a three-point beam is used. The recording / reproducing apparatus is designed to be performed under the tracking control operation to which the
A point beam was used in which the recording trace of the main signal on the disk surface of the information recording medium was arranged in a straight line diagonally crossing 3
Of the laser light spots, at least the tracking information is obtained by the laser light spot that is ahead of the laser light spot used to record the information signal to be recorded in the recording trace of the main signal. Signal and a rotation synchronizing signal, the means for reading various information signals recorded in the recording trace by the tracking pilot signal, and the recording trace of the main signal described above. The direction of the inclination of the straight line determined by the arrangement of three light spots arranged in a straight line so as to cross diagonally precedes the laser light spot used for recording the information signal in the recording trace of the main signal. Means for keeping the laser light spot being positioned closer to the area where the information signal is to be recorded, and the above-mentioned three lasers. Since it is a recording / reproducing apparatus for a repeatedly recordable information recording medium disk, which is provided with means for weakening the intensity of the laser beam for producing a spot during the reproducing operation rather than during the recording operation, the repeatedly recordable information recording according to the present invention. In the medium disc recording / reproducing apparatus, the center of the three light spots Lb1, Lb2, Lb3 arranged in a straight line so as to diagonally cross the recording trace of the main signal on the recording surface of the information recording medium disc D. The information signal of the recording trace of the main signal is recorded and reproduced by the optical spot Lb2 of the main signal, and the three laser light spots Lb1 and Lb2 of the laser light are arranged in a straight line so as to diagonally cross the recording trace of the main signal. , Lb3, two spots Lb1 and Lb3 of the laser light at both ends of the tracking pilot signal (tracking information signal) are configured to include at least a tracking information signal and a rotation synchronization signal. , Synchronization bit Sb, rotation synchronization signal Sr, and accumulated time value data St
One of the two laser beams is used to generate a tracking reference signal and is located at the boundary between the recording trace of one or more of the above) and the recording trace of the main signal. , Lb3, the laser light spot Lb1 preceding the laser light spot Lb2 used for recording the information signal to be recorded is
Various information signals recorded in the recording trace by the tracking pilot signal including at least the tracking information signal and the rotation synchronization signal, that is, the synchronization bit Sb, the rotation synchronization signal Sr, and the accumulated time value. Since the recording / reproducing operation can be performed by using it also for reading the data St and the like, the structure of the optical system is simplified, and further, the recording trace of the main signal is diagonally crossed. Three light spots Lb1, arranged on the line
The direction of the inclination of the straight line determined by the arrangement of Lb2 and Lb3 is
The laser beam spot Lb1 preceding the laser beam spot Lb2 used for recording the information signal on the recording trace of the main signal is positioned closer to the area where the information signal is to be recorded. In this case, when the information signal recording operation is performed on the new unrecorded information recording medium disk, the tracking state is temporarily defective, and the laser beam spot Lb1 is not recorded in the unrecorded state. Since the signal is not read from the recording trace of the main signal even if it is largely displaced toward the recording trace of the signal, the laser beam spot L used for recording the information signal on the recording trace of the main signal.
When the laser light spot Lb1 preceding the b2 is positioned near the area where the information signal has already been recorded, the tracking state becomes defective and the laser light spot Lb1 is recorded. The pilot signal can be read with a good S / N as compared with the state in which the main signal is largely displaced toward the recording trace of the state, and the recording / reproducing apparatus of the rewritable information recording medium disk according to the present invention is used. Since the recording trace of the main signal is different from the recording trace of the tracking pilot signal including at least the tracking information signal and the rotation synchronization signal, the S / S of the main signal is
N is good, and tracking is configured to include at least a tracking information signal and a rotation synchronizing signal which are pre-recorded in a predetermined entire area of the information recording medium disk in a non-erasable manner. By using the rotation synchronizing signal reproduced from the recording trace by the pilot signal of 1, the advantage that the recording and reproducing operation at high recording density by the CLV system can always be performed well is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing apparatus for a repeatedly recordable information recording medium disc of the present invention, FIG. 2 is a plan view of the information recording medium disc, and FIGS. 3 and 6 are recording by a pilot signal for tracking. FIG. 4 is an enlarged plan view showing traces and a laser beam spot, FIG. 4 is a characteristic curve diagram for explanation, FIG. 5 and FIG.
The figure is a diagram showing a configuration of a signal. D ... Information recording medium disk, 2 ... Lead-in signal area,
3 ... Main signal recording / reproducing area, 4 ... Readout signal area, 5 ... Motor, 6 ... Motor rotating shaft, 7 ... Turntable, 8 ... Clamper, 9 ... Motor drive control circuit, 10 ...... Optical recording / reproducing head, 10a ...... Recording / reproducing laser drive circuit, 10b ...... Recording / reproducing laser, 10c, 10i ...... Collimating lens, 10d, 10h ...... Correction element of laser beam cross-sectional shape, 10e ...... Diffraction grating, 10f ... Polarizing prism, 10g, 10l ... 1/4 wavelength plate, 10j ... Erase laser, 10k ... Erase laser drive circuit, 10m ... Dichroic mirror, 10n ... Condenser lens, 10o ...... Cylindrical lens, 10p …… Light receiving part consisting of multiple light receiving elements, 10q ……
Objective lens, 10r ... Actuator, 11 ... Transfer mechanism, 12 ... Control section, 13 ... Input section, 14 ... Input terminal of information signal to be recorded, 15 ... Encoder, 16
...... Recording circuit, 17 ...... Reproduction circuit, 18 ...... Tracking control circuit, 19 ...... Focus control circuit, 20 ...... Reproduction signal output terminal,

Claims (1)

[Claims] 1. A recording layer capable of erasing recorded information of a recording trace of a main signal, capable of repeatedly recording and reproducing an information signal, and erasing by changing a geometric shape. A spiral recording trace formed by a pilot signal for tracking, which is provided in parallel in advance with the recording trace of the main signal in an impossible manner and includes at least a tracking information signal and a rotation synchronization signal. A recording / reproducing operation at a constant linear velocity with respect to a recording trace of a main signal is performed by using an information recording medium disc having the following: a recording control operation using a three-point beam method. A reproducing apparatus, in which three laser beams generated by a three-point beam for tracking are arranged in a straight line diagonally crossing a recording trace of a main signal on a disk surface of an information recording medium. In the pot, at least the tracking information signal is rotationally synchronized with the laser light spot that is ahead of the laser light spot used to record the information signal targeted for recording in the recording trace of the main signal. Means for reading various information signals recorded in the recording trace by the tracking pilot signal including the signal, and the recording trace of the main signal crossing diagonally. A laser beam spot used for recording an information signal in a recording trace of a main signal, in a direction of inclination of a straight line determined by an array of three light spots arranged on a straight line Means for causing the light spot to be positioned closer to the area where the information signal is to be recorded,
A recording / reproducing apparatus for a repetitive recordable information recording medium disc, comprising means for weakening the intensity of the laser light for generating the above-mentioned three laser light spots in the reproducing operation than in the recording operation.