JP2000260023A - Information recording device, information recording medium and information reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make reproducible data even without recording a synchronizing signal showing a bit boundary in modulating a carrier signal and reproducing the data recording according to the change of a scan locus by generating a recording signal so as to repeat the same signal waveform in a cycle being shorter than the cycle of a bit boundary of input data. SOLUTION: An optical disk drive 1 records output data of an information source 3 on a master disk 2. In such a case, a data processing circuit 9 converts output data DINFO of the source 3 into 4-bit parallel data DD0 to DD3. A record signal generation circuit 10 generates a recording signal RS so as to repeat the same signal waveform in a cycle being shorter than the cycle of the bit boundaries of the data DD0 to DD3 between periods corresponding to 1-bit of the data DD0 to DD3 in the signal RS. An optical modulator 7 controls a laser beam L0 and emits a laser beam L1 whose light quantity changes in accordance with the signal RS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording device, an information recording medium, and an information reproducing device, and can be applied to, for example, an optical disk device. According to the present invention, a recording signal is generated so that the same signal waveform is repeated at a shorter cycle than a cycle of a bit boundary of data to be recorded. The carrier wave signal is modulated so that a recorded data sequence can be reproduced by a change in a scanning locus or the like. In addition, by integrating the synchronous detection result while avoiding the bit boundary, the data recorded in this way is prevented from being affected by the reproduction result due to the preceding and succeeding data.

[0002]

2. Description of the Related Art Conventionally, in an optical disk such as a compact disk, desired data is recorded by sequentially forming pits or marks based on a predetermined reference cycle.

[0003] That is, the process of making a compact disc is as follows:
Error correction code (ECC: Error Correcting Cod) is added to audio data obtained by sampling the audio signal.
e) after adding EFM (Eight to Fourteen Modulati
on) Modulate to generate a modulated signal. Further, in the process of producing a compact disk, after the laser beam is turned on and off by the modulation signal to expose the disk master, the disk master is developed to create a mother disk, and the mother disk is used to create a compact disk. .

[0004] Thus, the compact disc is EFM
After the data of the 8-bit string is converted into the data of the 17-bit string by the modulation, the data is converted into a serial data string, and 0.3 [μm] corresponding to the logical level of the serial data string.
Pits or spaces are sequentially formed in units of length.

[0005]

When reproducing data recorded in this manner, a compact disc player receives return light obtained by irradiating a compact disc with a laser beam and receives the return light according to the pit train. A reproduction signal whose signal level changes is generated, and the reproduction signal is binary-identified to generate reproduction data corresponding to serial data at the time of recording.

Accordingly, in a compact disk player, the length of pits and spaces formed on the compact disk in units of 0.3 [μm] is identified to generate reproduction data. 3 [μm]
, The signal level of the reproduction signal is binary-identified at a short time interval corresponding to the length of the data, and the serial data is reproduced. As a result, in the compact disc player, the logical level of the reproduced data may be erroneously reproduced due to instantaneous noise.

In a compact disc player,
Such bit errors in the reproduced data are subjected to error correction processing to a practically sufficient degree by the error correction code added at the time of recording. By the way, DVD (Digital Video Dis
Also in the case of k), the reproduction signal is generated by discriminating the reproduction signal by the binary at such a short time interval.
Same as compact disc player.

It is considered that if the bit error of the reproduced data due to such noise can be reduced, the recording density of this type of optical disk can be improved accordingly.

In this case, for example, Japanese Patent Application No. 10-12434.
It is considered that the method proposed in No. 2 can reduce bit errors in reproduced data due to this kind of noise and improve the recording density accordingly.

That is, this kind of noise is considered to be mainly caused by dust, dust and the like on the disk surface and appears concentrated in a relatively low frequency band of the reproduced signal. Accordingly, in the method proposed in Japanese Patent Application No. 10-124342, a carrier signal based on a sine wave signal is modulated by data to be used for recording to generate a modulation signal, and a groove is changed by the modulation signal to obtain a desired signal. Record the data. At the time of reproduction, the change in the groove is detected to generate a reproduction signal, and the synchronous detection result of the reproduction signal is integrated every period corresponding to one bit during recording to reproduce the original data. Thus, desired data is reproduced by reducing the influence of noise.

At this time, the groove is changed by a plurality of modulated signals using a plurality of orthogonal carrier wave signals, thereby securing a recording density. According to this method, desired data can be recorded / reproduced by efficiently utilizing the frequency characteristics of the signal-to-noise ratio of the optical disc, and as a result, the information recording density of the optical disc can be improved.

In this method, however, a synchronization signal is periodically recorded on an optical disk, and during reproduction, a synchronization detection result is integrated in bit units based on the synchronization signal, and the synchronization signal is recorded. Accordingly, there is a disadvantage that the recording density of the optical disk is reduced.

[0013] Further, by synchronously detecting a reproduction signal obtained by irradiating a laser beam with a constant beam diameter and integrating it at a constant period, the integration result changes according to the logical value of the preceding and succeeding data. There is a disadvantage that the accuracy of the data is still insufficient.

The present invention has been made in view of the above points, and when reproducing a data recorded by modulating a carrier signal and changing a scanning trajectory, a synchronous signal indicating a bit boundary is not required to be recorded. An information recording device, an information recording medium, and an information reproducing device capable of reproducing are proposed. Another object of the present invention is to propose an information reproducing apparatus capable of preventing the influence of a reproduction result due to preceding and succeeding data when reproducing data recorded by changing a scanning trajectory by modulating a carrier signal.

[0015]

According to a first aspect of the present invention, there is provided an information recording apparatus for recording input data by irradiating a recording beam according to a recording signal. The generation means compares with the period of the bit boundary of the input data in the recording signal or in a predetermined frequency band corresponding to the modulation signal forming the recording signal during a period corresponding to one bit of the input data in the recording signal. Then, a recording signal is generated such that the same signal waveform is repeated in a short cycle.

Further, in the invention according to claim 10, the present invention is applied to an information recording medium on which desired input data is recorded by a change of a groove or a ridge due to a scanning locus of a recording beam,
The change of the scanning trajectory or the change of the predetermined frequency band of the change of the scanning trajectory is the same in a period corresponding to one bit of the input data by a period shorter than the length between the bit boundaries of the input data. It is formed so that the change is repeated.

In the invention according to claim 15, when applied to an information reproducing apparatus, the synchronizing signal reproducing means delays the reproduced signal by a predetermined period shorter than a cycle of a bit boundary to generate a delayed reproduced signal. And a correlation detection means for detecting a correlation signal indicating the degree of coincidence between the delayed reproduction signal and the reproduction signal, and a synchronization signal generation means for generating a synchronization signal based on the correlation signal.

The invention according to claim 21 is applied to a similar information reproducing apparatus, and a detecting means for synchronously detecting a reproduced signal and outputting a detection result, and integrating the detection result with reference to the synchronous signal. And an identification means for identifying the integration result and outputting the reproduced data, wherein the integration means detects the signal by avoiding bit boundaries in the reproduced signal with reference to the synchronization signal. Integrate the result.

According to the configuration of the first aspect, during a period corresponding to one bit of input data in the recording signal, in the recording signal or in a predetermined frequency band corresponding to a modulation signal forming the recording signal, By generating a recording signal so that the same change is repeated in a cycle shorter than the cycle of the bit boundary of the input data, the playback apparatus that processes the playback signal corresponding to the recording signal generates Alternatively, in a signal obtained by band-limiting a reproduced signal, the same waveform is repeated during a period corresponding to one bit. As a result, on the reproducing side, the bit boundary can be detected by using the repetition of the same waveform, whereby the recorded data can be reproduced without recording the synchronization signal.

According to the tenth aspect of the present invention, the change in the scanning trajectory or the change in the predetermined frequency band of the change in the scanning trajectory corresponds to one bit of the input data. Since the same signal waveform is formed so as to be repeated in a cycle shorter than the length between the boundaries, the reproduction side that processes the reproduction signal whose signal level changes in accordance with the change in the scanning trajectory is used. In the reproduction signal, or in a signal obtained by band-limiting the reproduction signal, the same waveform is repeated during a period corresponding to one bit. As a result, on the reproducing side, the bit boundary can be detected by using the repetition of the same waveform, whereby the recorded data can be reproduced without recording the synchronization signal.

Further, according to the present invention, a delay means for delaying a reproduction signal by a predetermined period shorter than a cycle of a bit boundary to generate a delay reproduction signal, and a degree of coincidence between the delay reproduction signal and the reproduction signal By providing a correlation detection means for detecting a correlation signal indicating the following, and a synchronization signal generating means for generating a synchronization signal based on the correlation signal, a synchronization signal indicating a bit boundary is not recorded. Also, it is possible to reproduce recorded data by reproducing a synchronization signal based on a signal waveform repeated with a reproduced signal.

Further, according to the present invention, there is provided a detecting means for synchronously detecting a reproduced signal and outputting a detection result, and an integrating means for integrating the detection result based on the synchronous signal and outputting an integration result. And identification means for identifying the integration result and outputting reproduced data, wherein the integration means comprises:
By integrating detection results while avoiding bit boundaries in the reproduction signal with reference to the synchronization signal, even when data is reproduced by irradiating a reproduction beam with a constant beam spot diameter, the effect of the preceding and following bits can be effectively reduced. Can be avoided.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(1) First Embodiment (1-1) Configuration of First Embodiment FIG. 2 is a block diagram showing an optical disk device according to an embodiment of the present invention. The optical disc apparatus 1 exposes a master disc 2 and records input data DINFO output from an information source 3. In the manufacturing process of the optical disk, a mother disk is created by developing the disk master 2 and then electroforming to create a stamper from the mother disk. Further, in the optical disk manufacturing process, a disk substrate is prepared from the stamper thus prepared, and a reflective film and a protective film are formed on the disk substrate to prepare an optical disk.

That is, in the optical disk device 1,
The spindle motor 4 drives the disk master 2 to rotate,
The FG signal generation circuit held at the bottom outputs an FG signal FG whose signal level rises at every predetermined rotation angle. The spindle servo circuit 5 drives the spindle motor 4 according to the exposure position of the disk master 2 so that the frequency of the FG signal FG becomes a predetermined frequency, thereby rotating the disk master 2 at a predetermined rotation speed. I do.

The laser 6 is constituted by a gas laser or the like, and emits a laser beam L0 for exposing the master disc, which is a recording beam. Thus, the laser 6 constitutes a beam emission source for emitting a recording beam.

The optical modulator 7 is composed of an electroacoustic optical element, and controls a laser beam L0 according to a recording signal RS to emit a laser beam L1 whose light amount changes according to the recording signal RS. . Thus, the optical modulator 7 constitutes a beam modulating unit that modulates the recording beam according to the recording signal RS.

The laser beam L thus obtained is
1 is condensed on the master disk 2 by the objective lens 8 after the optical path is bent by a mirror (not shown). The mirror and the objective lens 8 are sequentially moved in the outer peripheral direction of the disk master 2 by a thread mechanism (not shown) in synchronization with the rotation of the disk master 2, thereby sequentially shifting the exposure position by the laser beam L1 in the outer peripheral direction of the disk master 2. To be displaced.

Thus, in the optical disc apparatus 1, tracks are formed in a spiral by moving the mirror and the objective lens 8 while the master disc 2 is driven to rotate, and the tracks are sequentially exposed according to the recording signal RS. Thus, the mirror and the objective lens 8 constitute beam irradiation means for irradiating the information recording medium with the recording beam modulated by the beam modulation means.

The information source 3 is composed of, for example, a digital audio tape recorder or the like, and sequentially outputs parallel data DINFO having a predetermined bit length for recording. The data processing circuit 9 outputs the output data D
The data DIN to be recorded is latched by latching INFO and sequentially outputting each word in units of 4 bits.
The FO is converted into 4-bit parallel data DD0 to DD3 and output.

The recording signal generation circuit 10 generates and outputs a recording signal RS from the 4-bit parallel data DD0 to DD3. Thus, the recording signal generation circuit 10 constitutes a recording signal generation unit that generates the recording signal RS according to the input data DD0 to DD3 to be recorded. At this time, the recording signal generation circuit 10 repeats the same signal waveform in a period shorter than the period of the bit boundary of the data DD0 to DD3 during the period corresponding to one bit of the data DD0 to DD3 in the recording signal RS. Thus, the recording signal RS is generated.

FIG. 1 is a block diagram showing the recording signal generation circuit 10. The recording signal generation circuit 10 includes the oscillator 1
1, a clock CK1 synchronized with the data DD0 to DD3 is generated and output. In this embodiment,
The data DD0 to DD3 are sequentially input from the data processing circuit 9 to the recording signal generation circuit 10 at timing based on the clock CK1 such that the bit boundaries of the data DD0 to DD3 correspond to the rising edge of the clock CK1.

The level conversion circuits 12A to 12D respectively output parallel data DD0 to DD output from the data processing circuit 9 at a timing based on the clock CK1.
Each bit of 3 is fetched, corrected and output so that the signal level of each bit changes around the 0 level. In this embodiment, each of the level conversion circuits 12A to 12D has an output signal level of +1 [V] at each logic level.
And -1 [V], the signal level of each bit is corrected.

A PLL (Phase Locked Loop) circuit 13A
Generates a carrier signal SC1 having a frequency f1 based on the clock CK1. At this time, the PLL circuit 13A generates the carrier signal SC1 so as to maintain a certain relationship with the bit boundaries of the parallel data DD0 to DD3.
Specifically, the PLL circuit 13A outputs the parallel data DD0.
Carrier signal with a sine wave signal of frequency f1 such that the frequency is twice the frequency f0 of clock CK1 and crosses level 0 at the rising edge of clock CK1. Generate SC1. Thereby, the PLL circuit 13A
Is the carrier wave signal SC represented by the following equation, with the time point at the bit boundary of the parallel data DD0 to DD3 being t = 0.
1 is generated.

[0035]

(Equation 1)

The PLL circuit 13B generates a carrier signal SC2 having a frequency f2 with reference to the clock CK1. At this time, the PLL circuit 13B outputs the parallel data DD0-D
The carrier signal SC2 is generated so as to maintain a certain relationship with the bit boundary of D3. Specifically, the PLL circuit 1
3B corresponds to the frequency f0 of the clock CK1 by 4 with respect to the clock CK1 synchronized with the parallel data DD0 to DD3.
The frequency f is doubled so as to cross the 0 level at the timing of the rising edge of the clock CK1.
A sine wave signal SC2 is generated. This allows the PLL circuit 13A to output the parallel data DD0 to DD0.
Assuming that the time point at the bit boundary of DD3 is t = 0, a carrier signal SC2 represented by the following equation is generated.

[0037]

(Equation 2)

The PLL circuit 13C generates a carrier signal SC3 having a frequency f1 with reference to the clock CK1. At this time, the PLL circuit 13C outputs the parallel data DD0-D
The carrier signal SC3 is generated so as to maintain a certain relationship with the bit boundary of D3. Specifically, the PLL circuit 1
3C generates a carrier signal SC3 based on a cosine signal having a frequency f1 such that the phase is different from the first carrier signal SC1 by 90 degrees. Thereby, the PLL circuit 13
C generates a carrier signal SC3 represented by the following equation by comparison with the equation (1).

[0039]

(Equation 3)

The PLL circuit 13D generates a carrier signal SC4 having a frequency f2 based on the clock CK1. At this time, the PLL circuit 13D outputs the parallel data DD0-D
The carrier signal SC4 is generated so as to maintain a certain relationship with the bit boundary of D3. Specifically, the PLL circuit 1
The 3D generates a carrier signal SC4 based on a cosine wave signal having a frequency f2 such that the phase is different from the second carrier signal SC2 by 90 degrees. Thereby, the PLL circuit 13
D generates a carrier signal SC4 represented by the following equation by comparison with equation (2).

[0041]

(Equation 4)

Thus, the recording signal generation circuit 10 generates two sets of orthogonal signals that are held in a fixed relationship with respect to the bit boundaries of the data DD0 to DD3 to be recorded, and is one of the repetition periods of the data DD0 to DD3. It generates carrier signals SC1 to SC4 repeated at a cycle of / 2 and 1/4.

Thus, the PLL circuits 13A to 13D
Plural sets of orthogonal carrier wave signals SC1 whose period is shorter than the period of the bit boundary of data DD0 to DD3 to be recorded.
To SC4.

The multiplication circuits 14A to 14D are provided with these carrier signals SC1 to SC4 and the level conversion circuits 12A to 12D.
Of the carrier signal SC1
To SC4 are modulated by data DD0 to DD3 to generate modulated signals M1 to M4. Thus, these modulation signals M1 to M4 can be expressed by the following equations using constants A1 to A4 set to values 1 or -1 according to the logical values of the data DD0 to DD3.

[0045]

(Equation 5)

Thus, the multiplication circuits 14A to 14D convert the carrier signals SC1 to SC4 into the corresponding input data DD0 to DD0.
Modulation means for modulating with DD3 to generate modulation signals M1 to M4 is configured.

The adder circuit 15 outputs these modulated signals M1 to M
4 and outputs the result, thereby constituting an adding means for adding the modulation signals M1 to M4. Signal level correction circuit 16
Amplifies this addition signal with a predetermined gain and gives an offset voltage, thereby correcting the addition signal to a signal level suitable for driving the optical modulator 7 and outputting a recording signal RS represented by the following equation. . Here, AA is an amplification factor by the signal level correction circuit 16, and BB is an offset voltage by the signal level correction circuit 16.

[0048]

(Equation 6)

Thus, in the recording signal generation circuit 10, during the period corresponding to one bit of the data DD0 to DD3 in the recording signal RS, the same period is used with a shorter period than the period of the bit boundary of the data DD0 to DD3. The recording signal RS is generated so that the signal waveform is repeated. In the optical disc device 1, the light amount of the laser beam L0 is modulated according to the recording signal RS.

FIG. 3 is a perspective view showing an optical disk.
This optical disk 20 is created from the master disk 2 exposed by the optical disk device 1. In the master disc 2, the light amount of the laser beam L0 is modulated by the recording signal RS, and the carrier signals SC1 to SC
Since the recording signal RS is generated by adding the modulation signals M1 to M4 by C4 and correcting the signal level, the exposure is performed so that the width of the continuous exposure trajectory changes according to the signal level of the recording signal RS. Is done. As a result, a groove (hereinafter, referred to as a groove) whose width is modulated in accordance with the signal level of the recording signal RS is formed on the optical disc 20, as shown by the reference numeral A in FIG. In the groove formed in this manner, the width may be extremely narrow, and the groove may be interrupted and become a land.

In this manner, data DD0 to DD3 are recorded on the optical disc 20 due to a change in the width of the groove, and one of the data DD0 to DD3 is recorded in this groove.
In the section corresponding to the bit, the same change is repeated in a cycle shorter than the length between the bit boundaries of the data DD0 to DD3.

FIG. 4 is a block diagram showing an optical disk apparatus for reproducing the optical disk 20. In the optical disk device 30, the spindle motor 31 drives the optical disk 20 to rotate at a predetermined rotation speed, and outputs an FG signal FG2 whose signal level rises at each predetermined rotation angle from an FG signal generation circuit held at the bottom. The spindle servo circuit 32 drives the spindle motor 31 so that the frequency of the FG signal FG becomes a predetermined frequency, thereby driving the optical disc 20 to rotate at a predetermined rotation speed.

The optical pickup 33 receives the return light obtained by irradiating the optical disk 20 with a laser beam, and thereby changes the signal level according to the tracking error amount with respect to the track center which is the center of the groove. An error signal TE, a focus error signal FE whose signal level changes according to the focus error amount, and a reproduction signal SU whose signal level changes according to the groove width are generated.

The optical pickup 33 generates the tracking error signal TE by a so-called three spot method. The optical pickup 33 generates a reproduction signal SU as a light receiving result of the light receiving surface on the central light receiving surface used for generating the tracking error signal by the three spot method. Thus, the optical pickup 33 constitutes a reproduction signal generation unit that generates a reproduction signal whose signal level changes in accordance with a change in a groove, which is a scanning trajectory of a recording beam formed on the optical disc 20.

The servo circuit 34 moves the objective lens of the optical pickup 33 based on the tracking error signal TE and the focus error signal FE, thereby performing tracking control and focus control.

The signal level correction circuit 35 amplifies the reproduction signal SU output from the optical pickup 33 with a predetermined gain, and applies an offset voltage so that the DC level becomes almost the same as the modulation signal at the time of recording. Playback signal S
The signal level of U is corrected and output. As a result, the signal level correction circuit 35 outputs the reproduction signal GRF represented by the following equation in comparison with the equation (6).

[0057]

(Equation 7)

The synchronizing signal reproducing circuit 36 detects a bit boundary from the reproducing signal GRF output from the signal level correcting circuit 35 and reproduces the synchronizing signal SY held in a fixed phase relationship with the bit boundary. .

The data reproducing circuit 37 outputs the synchronization signal SY
, And processing the reproduction signal GRF on the basis of the data to generate 4-bit parallel data DD0 to DD generated during recording.
3 is reproduced, and the data DD0 to DD3 are output from the original array.

Thus, the synchronizing signal reproducing circuit 36 generates the reproduced signal GR to which the data DD0 to DD3 are assigned.
F is processed to constitute a synchronizing signal reproducing means for reproducing a synchronizing signal SY having a fixed relation to the bit boundaries of the data DD0 to DD3, whereas the data reproducing circuit 37 uses this synchronizing signal SY as a reference. Then, the reproduction signal GRF to which the data DD0 to DD3 are assigned is processed to record the data DD0 to DD0 recorded on the optical disc 20 as the information recording medium.
A data reproducing means for reproducing D3 is constituted.

FIG. 5 is a block diagram showing the synchronizing signal reproducing circuit 36. The synchronization signal reproducing circuit 36 includes a delay circuit 40
The reproduction signal GRF is supplied to the sub-signal generator, and here, the reproduction signal GRF is delayed by a half cycle as compared with the cycle of the bit boundary to generate a delayed reproduction signal DRF. Here, as shown in FIG. 6, in this embodiment, the carrier signals SC1 to SC of １ ／ cycle and １ ／ cycle with respect to the cycle T0 of the bit boundary.
4 is quadrature-modulated, and the result of the modulation is added to modulate the width of the groove, so that in the reproduction signal GRF, the same signal is used before and after the time point tb between the bit boundaries ta and tc. The waveform is repeated (Fig. 6
(A)).

As a result, the signal waveform of the delayed reproduction signal DRF coincides with that of the reproduction signal GRF just before the bit boundary in the reproduction signal GRF and for a period cycle T1 which is １ ／ of the period T0 between the bit boundaries (FIG. 6 (B)). In the remaining period T2, the signal waveform rarely coincides with the reproduction signal GRF depending on the data to be recorded, but the majority has a different signal waveform. Thereby, the delay circuit 40
Represents the reproduction signal G for a predetermined period shorter than the cycle of the bit boundary.
The delay means for delaying the RF to generate the delayed reproduction signal DRF is configured.

In the synchronizing signal reproducing circuit 36, the correlation detecting circuit 41 generates and outputs a correlation degree signal CO indicating the degree of coincidence of the signal waveforms. That is, the correlation detection circuit 41
, The multiplication circuit 42 multiplies the delayed reproduction signal DRF and the reproduction signal GRF and outputs the result (FIG. 6C). Here, in the multiplied signal PR obtained in this way,
In the period T1 in which the signal waveforms of the delay reproduction signal DRF and the reproduction signal GRF coincide, the value always takes a positive value. On the other hand, during the period T2 when the signal waveforms do not match,
In (2), although the value differs depending on the recorded data, the average value generally becomes 0 when there is no deviation in the logical value in the data to be recorded (FIG. 6C).

Using this relationship, the correlation detection circuit 41
The multiplied signal PR, which is the result of the multiplication, is represented by a bit boundary period T.
By cyclically adding with a delay of 0, a correlation signal CO (FIG. 6D) whose signal level rises in a period T1 in which the signal waveforms of the delayed reproduced signal DRF and the reproduced signal GRF coincide with each other is generated.

That is, in the correlation detection circuit 41, the addition circuit 43 adds the output signal PR of the multiplication circuit 42 to the output signal of the delay circuit 44 and outputs the result. The attenuator 45 outputs the output signal of the addition circuit 43. The output is attenuated by a predetermined attenuation rate. The delay circuit 44 delays the output signal of the attenuator 45 by the period of the bit boundary period T0. The correlation detection circuit 41 outputs the output signal of the attenuator 45 as a correlation degree signal CO. Note that the attenuator 45 performs the cyclic addition in this manner to perform the cyclic addition, and the correlation degree signal C during the period T1 in which the signal waveforms of the delayed reproduction signal DRF and the reproduction signal GRF coincide.
The attenuation factor is set so that the signal level of O does not increase beyond a certain value. Thus, the correlation level signal CO is created so that the signal level switches at the time points ta and tc at the bit boundary and at the time point tb at the center of the bit boundary.

Thus, the correlation detecting circuit 41 constitutes a correlation detecting means for detecting a correlation degree signal CO indicating the degree of coincidence between the reproduced signal GRF and the delayed reproduced signal DRF. More specifically, the correlation degree signal CO is generated so as to show a large value during a period in which the signal waveforms should match, and to show a small value in a period in which it is not determined whether the signal waveforms match. The addition circuit 43, the attenuator 45, and the delay circuit 44
A cyclic addition circuit is configured in which the multiplication signal obtained from the multiplication circuit is delayed by the period of the bit boundary and cyclically added.

The synchronizing signal generation circuit 46 is constituted by a PLL circuit, and the synchronizing signal SY having a phase leading the correlation signal CO by 90 degrees with respect to the correlation signal CO.
(FIG. 6E) is generated. Accordingly, the synchronization signal generation circuit 46 avoids the bit boundary in the reproduction signal GRF and generates the synchronization signal SY having the signal level rising during one period of the carrier signals SC1 and SC3 and two periods of the carrier signals SC2 and SC4. Generate.

FIG. 7 is a block diagram showing the data reproducing circuit 37. The data reproducing circuit 37 reproduces the carrier signals SC1 to SC4 based on the synchronization signal SY, and synchronously detects the reproduced signal GRF based on the carrier signals SC1 to SC4. Further, the synchronous detection result is integrated with reference to the synchronous signal SY, and the original 4-bit parallel data DD is obtained.
0 to DD3 are reproduced and output in the original arrangement.

That is, in the data reproducing circuit 37, P
The LL circuit 50A operates based on the synchronization signal SY,
A carrier signal SW1 corresponding to the carrier signal SC1 at the time of recording is generated. Here, the carrier signal SW1 is (1)
It is expressed by the following equation by comparison with the equation.

[0070]

(Equation 8)

The multiplying circuit 51A receives the carrier signal SW1
And the reproduction signal GRF, thereby outputting a synchronous detection result D1 represented by the following equation.

[0072]

(Equation 9)

The integration circuit 52A resets the integration result in synchronization with the synchronization signal SY, and integrates the synchronization detection result D1 output from the multiplication circuit 51A during the period when the signal level of the synchronization signal SY rises. Thus, an integration result I1 represented by the following equation is output.

[0074]

(Equation 10)

Here, the equation (10) is a process for integrating the synchronous detection result by the carrier signal SW1 of the frequency f1 during the period in which the synchronous signal SY rises, and the integration section T0 / 2 corresponds to the frequency f1. , F2, the integral result of the equation (10) is represented by the following equation.

[0076]

[Equation 11]

The level conversion circuit 53A calculates the integration result I
By binary-identifying 1, the data DD0 at the time of recording is reproduced and output.

The PLL circuit 50B operates based on the synchronization signal SY to generate and output a carrier signal SW2 corresponding to the carrier signal SC2 at the time of recording. Here, the carrier signal SW2 is expressed by the following equation in comparison with the equation (2).

[0079]

(Equation 12)

The multiplying circuit 51B outputs the carrier signal SW2
And the reproduction signal GRF, thereby outputting a synchronous detection result D2 represented by the following equation.

[0081]

(Equation 13)

The integration circuit 52B resets the integration result in synchronization with the synchronization signal SY, and integrates the synchronization detection result D1 output from the multiplication circuit 51B during the period when the signal level of the synchronization signal SY rises. Thus, an integration result I2 represented by the following equation is output.

[0083]

[Equation 14]

Here, the equation (14) is a process for integrating the synchronous detection result by the carrier signal SW2 of the frequency f2 during the period when the synchronous signal SY rises, and the integral section T0 / 2 corresponds to the frequency f1. , F2, the integral result of equation (14) is represented by the following equation.

[0085]

(Equation 15)

The level conversion circuit 53B calculates the integration result I
By binary-identifying 2, the data DD1 at the time of recording is reproduced and output.

The PLL circuit 50C operates on the basis of the synchronization signal SY, and generates and outputs a carrier signal SW3 corresponding to the carrier signal SC3 at the time of recording. Here, the carrier signal SW3 is expressed by the following equation in comparison with the equation (3).

[0088]

(Equation 16)

The multiplying circuit 51C outputs the carrier signal SW3
And the reproduction signal GRF, thereby outputting a synchronous detection result D3 represented by the following equation.

[0090]

[Equation 17]

The integration circuit 52C resets the integration result in synchronization with the synchronization signal SY, and integrates the synchronization detection result D3 output from the multiplication circuit 51C during the period when the signal level of the synchronization signal SY rises. Thus, an integration result I3 represented by the following equation is output.

[0092]

(Equation 18)

The equation (18) is a process for integrating the synchronous detection result by the carrier signal SW3 of the frequency f1 during the period when the synchronous signal SY rises, and the integration section T0 / 2 is performed at the frequency f1. , F2, the integral result of equation (18) is expressed by the following equation.

[0094]

[Equation 19]

The level conversion circuit 53C calculates the integration result I
3 is binary-identified, thereby reproducing and outputting the data DD2 at the time of recording.

The PLL circuit 50D operates based on the synchronization signal SY, and generates and outputs a carrier signal SW4 corresponding to the carrier signal SC4 at the time of recording. Here, the carrier signal SW4 is expressed by the following equation in comparison with the equation (4).

[0097]

(Equation 20)

The multiplying circuit 51D receives the carrier signal SW4
And the reproduction signal GRF, thereby outputting a synchronous detection result D4 represented by the following equation.

[0099]

(Equation 21)

The integration circuit 52D resets the integration result in synchronization with the synchronization signal SY, and integrates the synchronization detection result D4 output from the multiplication circuit 51D while the signal level of the synchronization signal SY is rising. Thus, an integration result I4 represented by the following equation is output.

[0101]

(Equation 22)

Here, the equation (22) is a process for integrating the synchronous detection result by the carrier signal SW4 of the frequency f2 during the period when the synchronous signal SY rises, and the integration section T0 / 2 corresponds to the frequency f1. , F2 is an integral multiple of the reciprocal of f2, so that the integration result by the expression (22) is expressed by the following expression.

[0103]

(Equation 23)

The level conversion circuit 53D calculates the integration result I
4 is binary-identified to reproduce and output the data DD3 at the time of recording.

The data processing circuit 54 outputs the output data DD0 to DD0 output from the level conversion circuits 53A to 53D.
DD3 is rearranged, and reproduced data DINFO is output.

(1-2) Operation of the First Embodiment In the above configuration, the data DINFO recorded on the disk master 2 (FIG. 2) is 4-bit parallel data DD0 to DD3 in the data processing circuit 9. And input to the recording signal generation circuit 10. In the recording signal generation circuit 10, the data DD0 to DD3 (FIG. 1) are sequentially input at a timing synchronized with the clock CK1 output from the oscillator 11, and the level conversion circuits 12A to 12D use the signals based on the 0 level respectively. The signal level is corrected so that the level changes.

In the recording signal generation circuit 10, the PLL
The circuits 13A to 13D cross the zero at the rising edge of the clock CK1 corresponding to the bit boundaries of the data DD0 to DD3 at the frequencies f1 and f2 twice and four times the frequency of the clock CK1, respectively, based on the clock CK1. Two sets of orthogonal carrier signals SC1 to SC4
Is generated. Further, each of these carrier signals SC1 to SC
4 are respectively modulated by the output signals of the level conversion circuits 12A to 12D, and the resulting modulated signals M1 to M
4 is added by the adding circuit 15. Thereafter, in the recording signal generation circuit 10, the signal level of the addition signal output from the addition circuit 15 is corrected by the signal level correction circuit 16 to generate the recording signal RS.

Thus, in the optical disk device 1,
During a period corresponding to one bit of the input data DD0 to DD3 in the recording signal RS, the input data DD0 to DD3
The recording signal RS is generated such that the same signal waveform is repeated at a cycle shorter than the cycle of the bit boundary of D3.

In the optical disk device 1, the optical modulator 7 is driven by the recording signal RS generated by correcting the signal level in this manner, and the light amount of the laser beam L0 emitted from the laser 6 is changed to the signal of the recording signal RS. The laser beam L1 which changes according to the level and is emitted from the optical modulator 7 is condensed on the master disc 2, and the master disc 2 is exposed.

As a result, in the optical disc 20 generated by processing the master disc 2 (FIG. 3), a groove is formed in the irradiation locus of the laser beam, and the width of the groove is determined according to the signal level of the recording signal RS. It is formed so as to change, that is, in the section corresponding to one bit of the input data DD0 to DD3, the same change is repeated by a shorter length than the length between the bit boundaries of the input data DD0 to DD3. .

As a result, in the synchronous detection result obtained by multiplying the reproduction signal SU whose signal level changes in accordance with the change of the groove width with each of the carrier signals SC1 to SC4 (SW1 to SW4), each data DD0 to DD0 is obtained. This means that the logic level of DD3 is being demodulated. Further, in the integration result obtained by integrating the multiplication result by a cycle of one cycle of the carrier signals SC1 to SC4, the signal level does not change depending on the logic level of the other data DD0 to DD3, and the corresponding result. The signal level changes only depending on the logic levels of the data DD0 to DD3.

As a result, on the optical disk, the data DD0 to DD3 of the four systems are multiplexed and recorded in a distributed manner in the groove section corresponding to the cycle of the bit boundary. On the other hand, in the conventional optical disk,
1 depending on the timing of the edge in the pit or mark
Bit data will be sequentially reproduced. As a result, in this embodiment, in the reproduction signal SU obtained from the optical disk 20, the influence of instantaneous noise is reduced, and the effective SNR can be improved by that amount, and the effective signal-to-noise ratio can be improved accordingly. Thus, a sufficient margin for high-density recording can be secured.

The frequency band of the reproduction signal SU obtained by detecting the change in the width of the groove in this manner is a frequency band synthesized by amplitude modulation of the carrier signals SC1 to SC4. As a result, the frequencies of the carrier signals SC1 to SC4 can be set so as to avoid a frequency band in which noise is concentrated in this type of system, and the effective SNR can be further improved. A sufficient margin for density recording can be secured.

Further, not only the frequency band of this noise but also the frequency of the carrier signal S
By setting the frequencies C1 to SC4, high-density recording can be performed by effectively and efficiently using the frequency characteristics of the recording / reproducing system.

Thus, the optical disk 20 (FIG. 4) is used in the optical disk device 30 to store the optical pickup 3
When the laser beam emitted from 3 is irradiated and its return light is received, a reproduction signal SU whose signal level changes according to the width of the groove is detected, and the signal level of this reproduction signal SU is corrected for signal level. The correction is performed by the circuit 35. Further, the synchronizing signal reproducing circuit 36 generates a synchronizing signal SY held in a fixed relationship with the bit boundary,
The data DINFO recorded on the optical disc 20 by the processing of the data reproducing circuit 37 based on the synchronization signal SY.
Is played.

In the processing of the data reproducing circuit 37 (FIG. 7), in the optical disk device 30, the carrier signals S1 to SC4 corresponding to the carrier signals SC1 to SC4 at the time of recording in the PLL circuits 50A to 50D with reference to the synchronization signal SY.
W1 to SW4 are generated, and these carrier signals SW1 to S4 are generated.
W4 is multiplied by the reproduction signal GRF in the multiplication circuits 51A to 51D, respectively.
To DD3 are obtained as synchronous detection results D1 to D4. Synchronous detection results D1 to D4 are obtained by integrating circuits 52A to 52D.
Are integrated, and the level conversion circuits 53A to 53D discriminate the integration results I1 to I4 into binary data, and the data DD0 to DD3
Is played. The data DD0 to DD3 are returned to the original arrangement in the subsequent data processing circuit 55, whereby the output data DINFO of the information source 3 is reproduced.

At this time, the noise component mixed in the reproduction signal GRF is smoothed by integration in the integration circuits 52A to 52D, whereby the bit error in the reproduction data DINFO is remarkably improved as compared with the related art.

Further, at the time of integration in the integration circuits 52A to 52D, synchronous detection is performed only for one period of the carrier signal SW1 and SW3 having the lowest frequency with respect to the synchronous signal SY so as to avoid bit boundaries of the reproduced signal GRF. Result D
By integrating 1 to D4, each data DD0 to DD
In the integration results I1 to I4 of 3, a change due to the preceding and succeeding bits can be prevented, thereby further reducing bit errors as compared with the related art.

On the other hand, in the synchronous signal reproducing circuit 36 (FIG. 5), the reproduced signal GRF is
The delayed reproduction signal DRF is generated by being delayed by the delay circuit 40 for a short period in which the same signal waveform is repeated for a short period shorter than the period of the bit boundary of D3, and the delayed reproduction signal DRF is multiplied by the multiplication circuit. 42, the reproduced signal GR
F (FIG. 6). Thus, the product signal PR
In the above, the signal level always rises positively during a period in which the signal waveforms of the delayed reproduction signal DRF and the reproduction signal GRF coincide with each other, and the signal level changes around the 0 level in other portions. And the reproduced signal GR
The start point and the end point of the period in which this signal level always rises to the positive side with respect to F show a certain relationship with the bit boundary of the reproduction signal GRF.

In this embodiment, carrier signals SC1 to SC1
The longest cycle in SC4 is the data DD0 to DD3.
, The start time and the end time of the period during which the multiplication result PR always rises to the positive side indicate the center time and the bit boundary between the bit boundaries, respectively. .

As a result, in the optical disk device 30, the multiplication result PR is cyclically added by the cyclic addition circuit including the addition circuit 43, the attenuator 45, and the delay circuit 44 after being delayed by a period corresponding to the cycle of the bit boundary. Result P
During the period when R is always rising to the positive side, the signal level is raised to a predetermined level, and during the period when the signal level changes around the 0 level, the signal level is set to 0 level. And thereby the correlation signal C as a criterion for determining the bit boundary of the reproduction signal GRF.
O is generated.

At this time, in this embodiment, as described above, the longest cycle of carrier signals SC1 to SC4 is １ ／ of the bit cycle of data DD0 to DD3.
In the addition result CO obtained by the cyclic addition in this manner, the rising edge indicates the center point between bit boundaries, and the falling edge indicates the bit boundary.

As a result, in the optical disk device 30, the addition result CO is input to the synchronization signal generation circuit 46 as the correlation signal CO, and here the phase difference of 90 degrees with respect to the bit boundary is set with reference to the correlation signal CO. A different synchronization signal SY is generated. Thereby, the optical disk device 30
Then, the synchronization signal S held in a fixed relation to the bit boundary from the reproduction signal GRF to which the data is assigned
Y can be generated. Accordingly, in this embodiment, a reference signal indicating a bit boundary is separately transmitted to the optical disc 20.
The data recorded on the optical disk 20 can be reproduced without recording on the optical disk 20, and the recording density of the optical disk 20 can be improved accordingly.

Further, in the optical disk device 30, the integration circuits 52A to 52D use the synchronization signal SY having a phase difference of 90 degrees with respect to the bit boundary as a reference to obtain the synchronous detection result so as to avoid the bit boundary. The multiplication results D1 to D4 are integrated. At this time, in this embodiment, as described above, since the longest cycle of carrier signals SC1 to SC4 is set to の of the bit cycle of data DD0 to DD3, the multiplication results D1 to D4 have , The corresponding carrier signal SW1
The integration is performed only for the period of the integral wave of SW4.

Thus, in this embodiment, with a simple configuration, the synchronous detection results D1 to D4 are transmitted to the carrier signal SC1.
To SC4, the signal level does not change depending on the logic level of the other data DD0 to DD3, and the corresponding data DD0 to DD3
In this case, the integration results I1 to I4 can be obtained such that the signal level changes only according to the logical level of the above. Thus, a bit error can be effectively avoided.

(1-3) Effects of the First Embodiment According to the above configuration, when recording desired data by changing the groove width in accordance with the recording signal, the bit boundary of the data to be recorded is recorded. By generating a recording signal so as to repeat the same signal waveform in a shorter cycle than the cycle of the above, even if a synchronization signal indicating a bit boundary is not recorded,
Data recorded on the optical disc can be reproduced. Accordingly, the recording density of the optical disk can be improved accordingly.

Further, at this time, by modulating a plurality of sets of orthogonal carrier signals and generating the recording signal by using the resultant addition signal, the effect of noise can be effectively avoided and desired data can be obtained as compared with the related art. Can be recorded at high density.

On the reproduction side, the reproduction signal to which the data is assigned is processed, and the synchronization signal indicating the bit boundary is reproduced by reproducing the synchronization signal having a fixed relation to the bit boundary of the data. The data recorded on the optical disk can be reproduced without recording. Accordingly, the recording density of the optical disk can be improved accordingly.

At this time, the reproduced signal is delayed by a predetermined time to generate a delayed reproduced signal, and a correlation signal indicating the degree of coincidence between the delayed reproduced signal and the reproduced signal is detected. By generating the signal, the reproduced signal to which the data is allocated in this way is processed, and the characteristic of the reproduced signal is effectively used in reproducing the synchronous signal having a fixed relation to the bit boundary of the data. Thus, a bit boundary can be reliably detected.

Further, by integrating the synchronous detection result of the reproduction signal while avoiding the bit boundary, it is possible to prevent the data recorded in this way from affecting the reproduction result by the preceding and following data.

(2) Other embodiments

In the above embodiment, the case where the correlation signal is detected by directly delaying the reproduction signal has been described. However, the present invention is not limited to this. For example, a predetermined modulation is performed on the reproduction signal by a band-pass filter. Only the signal component may be extracted, and the modulation signal component may be delayed to determine the coincidence of the waveforms. By doing so, the relationship between the cycle of the bit boundary and the frequency of the carrier signal can be set more freely, and desired data can be recorded and reproduced as in the above-described embodiment. In this case, the delay time for generating the delay reproduction signal can be shortened according to the frequency of the modulated signal to be extracted, and the integration period with respect to the bit period can be lengthened.

Further, in the above-described embodiment, a case has been described in which a synchronous signal is generated from a reproduced signal, and a synchronous detection result is integrated while avoiding a bit boundary. However, the present invention is not limited to this. If a sufficient recording density can be secured, a configuration that only integrates the synchronous detection result while avoiding bit boundaries may be adopted.On the contrary, if a practically sufficient bit error rate can be secured. Is
Only a configuration for generating a synchronization signal from a reproduction signal may be employed.

In the case of adopting a configuration that only generates a synchronizing signal from a reproduced signal, the data reproducing circuit is variously used, for example, when a noise component is removed from a synchronous detection result using a low-pass filter instead of an integrating circuit. Can be applied.

In the above-described embodiment, in carrier signals SC1 to SC4, the cycle of carrier signals SC1 and SC3 having the lowest frequency is １ ／ of the cycle of the bit boundary.
By setting so that
Although the case where the same signal waveform is repeated in a half cycle of the bit cycle has been described, the present invention is not limited to this. In short, the same signal waveform is repeated in a cycle shorter than the bit cycle. Thus, the same effect as in the above-described embodiment can be obtained.

Also, in the above-described embodiment, the frequency of one set of carrier signals SC1 and SC3 having the lowest frequency is set to twice the frequency of the other set of carrier signals SC2 and SC4. , But
The present invention is not limited to this, and may be set to a frequency other than an integer multiple if each bit can be demodulated sufficiently without being affected by other modulated signals in practical use.

Further, in the above-described embodiment, a case has been described in which the data DD0 to DD3 of the four systems are recorded and reproduced at the same data transfer rate. However, the present invention is not limited to this, and any one of them may be used as necessary. The transfer speed of the data string may be changed. That is, for example, if the data transfer rate is reduced for the data sequence allocated to the low frequency side and the high frequency side where the frequency characteristics are deteriorated, one bit can be dispersedly recorded over a long distance on the optical disc for the data sequence. Bit errors can be further improved.

In the above-described embodiment, a case has been described in which all of the two carrier signals SC1 to SC4 are modulated and processed by data to be transmitted.
The present invention is not limited to this. For example, one of the highest frequency reference signals may be assigned to address information or the like, and may be recorded as a clock generation reference signal without any modulation.

In the above-described embodiment, a case has been described in which a plurality of sets of orthogonal carrier signals SC1 to SC4 are modulated by binary values. However, the present invention is not limited to this, and each carrier signal is modulated by multiple values. May be. In this case, the recording density can be further improved.

In the above embodiment, the case where desired data is recorded by changing the width of the groove has been described. However, the present invention is not limited to this, and the desired data is recorded by changing the depth of the groove. Alternatively, desired data may be recorded by a displacement in the width direction, which is a meandering groove, or a combination of these may be recorded. When the information is recorded by the displacement of the groove in the width direction as described above, in the optical pickup on the reproducing side, the light receiving surface is divided by a dividing line corresponding to the direction in which the track extends, and the light receiving surface of the divided light receiving surface is divided. Means for detecting a reproduction signal based on the difference signal can be used.

In the above-described embodiment, a case has been described in which an optical disc is prepared by processing a master disc so that the scanning trajectory of a laser beam is a groove as a groove. However, the present invention is not limited to this. Conversely, the present invention can be widely applied to a case where a disc master is processed to produce an optical disc such that the scanning trajectory of the laser beam becomes an elongated projection (a protruding strip).

In the above embodiment, the case where the width of the groove is changed or the groove is displaced in the width direction has been described. However, the present invention is not limited to this, and the width of the pit or mark is changed. Alternatively, the pits or marks may meander. In this way, for example, key data required for descrambling of main data recorded by pits and marks is assigned to the width of these pits or marks, or skewed to pits or marks, multiplexed, and distributed recording is performed. can do.

In the above-described embodiment, the case where the tracks are formed spirally has been described. However, the present invention is not limited to this, and can be widely applied to the case where tracks are formed concentrically.

Further, in the above-described embodiment, a case has been described in which an optical disk is prepared by exposing a disk master. However, the present invention is not limited to this, and for example, a rewritable disk represented by a magneto-optical disk or a phase change disk is used. The present invention can be widely applied to various optical disk systems, for example, when applied to possible optical disks.

Further, in the above-described embodiment, the case where the present invention is applied to the optical disk device using the laser beam as the recording beam and the reproducing beam has been described. However, the present invention is not limited to this, and the recording beam may be applied. Also, the present invention can be widely applied to a recording / reproducing apparatus using an electron beam as a reproducing beam.

In the above-described embodiment, the case where the present invention is applied to an optical disk device has been described. However, the present invention is not limited to this, and for example, a recording beam and a reproducing beam are irradiated on a card-shaped recording medium. Thus, the present invention can be widely applied to the case of recording and reproducing desired data.

[0147]

As described above, according to the present invention, a recording signal is generated so as to repeat the same signal waveform in a cycle shorter than the cycle of a bit boundary of data to be recorded, thereby forming a bit boundary. Even if the synchronization signal shown is not recorded, it is possible to reproduce the recorded data sequence by modulating a predetermined carrier signal and changing the scanning trajectory. Therefore, the recording density can be improved accordingly.

By integrating the synchronous detection result while avoiding bit boundaries, it is possible to prevent the data recorded in this way from being affected by the reproduction result of the preceding and succeeding data, thereby improving the reliability. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a recording signal generation circuit of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an optical disc device to which the recording signal generation circuit of FIG. 1 is applied.

FIG. 3 is a perspective view showing an optical disk manufactured by using the optical disk device of FIG. 1;

FIG. 4 is a block diagram showing an optical disk device for reproducing the optical disk of FIG.

FIG. 5 is a block diagram showing a synchronization signal reproducing circuit of the optical disk device of FIG.

FIG. 6 is a signal waveform diagram for explaining the operation of the synchronization signal reproducing circuit of FIG. 5;

FIG. 7 is a block diagram showing a data reproducing circuit of the optical disk device of FIG.

[Explanation of symbols]

1, 30 ... optical disk device, 2 ... disk master, 3
…… information source, 6 …… laser, 7 …… optical modulator, 9 ……
Data processing circuit, 10 ... Recording signal generation circuit, 11 ...
Oscillator, 13A to 13D, 50A to 50D ... PLL circuit, 14A to 14D, 42, 51A to 51D ... Multiplication circuit, 15, 43 ... Addition circuit, 20 ... Optical disk, 3
3 ... optical pickup, 36 ... sync signal reproducing circuit, 3
7 Data reproduction circuit, 40, 44 Delay circuit, 45
... attenuator, 46 ... synchronization signal generation circuit, 52A-52
D ... Integrating circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 20/10 341 G11B 20/10 341Z 20/14 351 20/14 351A F-term (Reference) 5D029 WB11 WB17 5D044 BC02 BC04 BC10 CC05 CC06 JJ01 JJ02 5D090 AA01 BB04 CC01 CC04 CC14 CC16 DD03 DD05 EE15 FF13 GG02 GG09 HH01 KK03 KK09 KK17

Claims (24)

[Claims] 1. An information recording apparatus which scans an information recording medium with a recording beam and records input data on the information recording medium by changing a scanning locus of the recording beam, wherein the recording is performed according to the input data. Recording signal generation means for generating a signal; a beam emission source for emitting the recording beam; beam modulation means for modulating the recording beam in accordance with the recording signal; and the recording modulated by the beam modulation means. Beam irradiating means for irradiating the information recording medium with a beam for use, wherein the recording signal generating means, during a period corresponding to one bit of the input data in the recording signal, in the recording signal or in the recording In a predetermined frequency band corresponding to a modulation signal forming a signal, the same signal waveform is generated by a cycle shorter than a cycle of a bit boundary of the input data. Ri as returned, the information recording device and generates said recording signal. 2. The information recording apparatus according to claim 1, wherein the beam modulator modulates the intensity of the recording beam according to the recording signal. 3. The information recording apparatus according to claim 1, wherein the beam modulator displaces the recording beam in a direction orthogonal to a scanning direction according to the recording signal. 4. The recording signal generating means includes: a carrier signal generating means for generating a plurality of sets of orthogonal carrier signals having a shorter cycle than a cycle of the bit boundary; and a modulating the carrier signal by corresponding input data. The information recording apparatus according to claim 1, further comprising: a modulation unit configured to generate a modulation signal, and an addition unit configured to add the modulation signal. 5. An information recording apparatus according to claim 4, wherein said modulation means is a multiplication circuit for multiplying said carrier signal and corresponding input data. 6. The plural sets of orthogonal carrier signals are a plurality of sine wave signals having different frequencies from each other and a plurality of cosine wave signals corresponding to the sine wave signals. Information recording device according to the above. 7. The information recording apparatus according to claim 6, wherein the plurality of sine wave signals have a frequency set to an integral multiple of a predetermined fundamental frequency higher than the frequency of the data string. 8. An information recording apparatus according to claim 1, wherein said recording beam is a light beam. 9. The information recording apparatus according to claim 1, wherein said recording beam is an electron beam. 10. An information recording medium on which desired input data is recorded by a change in a scanning trajectory of a recording beam, wherein the change in the scanning trajectory or the change in a predetermined frequency band of the change in the scanning trajectory is detected. An information recording medium, wherein the same change is repeated in a period corresponding to one bit of the input data in a cycle shorter than a length between bit boundaries of the input data. 11. The information recording medium according to claim 10, wherein the information recording medium is formed in a disk shape, and the scanning trajectory is formed concentrically or spirally. 12. The method according to claim 1, wherein the change in the scanning trajectory is a change in the width of an irradiation trace of the recording beam.
0. The information recording medium according to 0. 13. The information recording medium according to claim 10, wherein the change in the scanning trajectory is a change in the depth or height of a groove or a protrusion due to the scanning trajectory. 14. The information recording medium according to claim 10, wherein the change in the scanning trajectory is a displacement in the width direction of the irradiation trace of the recording beam. 15. An information reproducing apparatus for irradiating a reproduction beam onto an information recording medium and reproducing data recorded on the information recording medium from an irradiation result, wherein the information recording medium is formed on the information recording medium based on the irradiation result. Reproduction signal generation means for generating a reproduction signal whose signal level changes in accordance with a change in the scanning locus of the recording beam, and processing the reproduction signal to which the data is allocated, and setting the data to a bit boundary of the data. A synchronizing signal reproducing means for reproducing a synchronizing signal having a predetermined relationship with respect to the synchronizing signal; and processing the reproducing signal to which the data is assigned based on the synchronizing signal to reproduce data recorded on the information recording medium. The synchronization signal reproducing means delays the reproduced signal by a predetermined period shorter than the cycle of the bit boundary to generate a delayed reproduced signal. Means, a correlation detection means for detecting a correlation signal indicating the degree of coincidence between the delayed reproduction signal and the reproduction signal, and a synchronization signal generation means for generating the synchronization signal based on the correlation signal. Characteristic information reproducing device. 16. A multiplication circuit for multiplying the delayed signal and the reproduction signal to output a multiplication signal, and a cyclic addition circuit for delaying the multiplication signal by the cycle of the bit boundary and performing cyclic addition. The information reproducing apparatus according to claim 15, comprising: 17. The information reproducing apparatus according to claim 15, wherein said reproducing signal generating means generates said reproducing signal such that a signal level changes in accordance with a change in a width of said scanning trajectory. . 18. The reproduction signal generating means generates the reproduction signal such that a signal level changes in accordance with a change in a groove depth or a ridge height according to the scanning trajectory. The information reproducing apparatus according to claim 15. 19. The information reproducing apparatus according to claim 15, wherein said reproducing signal generating means generates said reproducing signal such that a signal level changes in accordance with a displacement of said scanning trajectory in a width direction. apparatus. 20. A data reproducing means, comprising: a detecting means for synchronously detecting the reproduced signal and outputting a detection result; and an integrating means for integrating the detection result based on the synchronous signal and outputting an integration result. And identification means for identifying the integration result and outputting reproduction data, wherein the integration means integrates the detection result avoiding a bit boundary in the reproduction signal based on the synchronization signal. The information reproducing apparatus according to claim 15, wherein 21. An information reproducing apparatus for irradiating an information recording medium with a reproducing beam and reproducing data recorded on said information recording medium from an irradiation result, wherein said apparatus reproduces data recorded on said information recording medium based on said irradiation result. Reproduction signal generation means for generating a reproduction signal whose signal level changes in accordance with a change in the scanning trajectory of the recording beam; synchronization signal reproduction means for detecting a bit boundary in the reproduction signal and reproducing a synchronization signal; Detection means for synchronously detecting the reproduction signal and outputting a detection result; integration means for integrating the detection result and outputting an integration result with reference to the synchronization signal; and reproducing data by identifying the integration result. Identification means for outputting the information, wherein the integration means integrates the detection result while avoiding a bit boundary in the reproduction signal based on the synchronization signal. Playback device. 22. The information reproducing apparatus according to claim 21, wherein said reproduction signal generation means generates said reproduction signal such that a signal level changes according to a change in a width of said scanning trajectory. . 23. The reproduction signal generation means, wherein the reproduction signal is generated such that a signal level changes in accordance with a change in a depth of a groove or a height of a ridge due to the scanning trajectory. An information reproducing apparatus according to claim 21. 24. The information reproduction apparatus according to claim 21, wherein said reproduction signal generation means generates said reproduction signal such that a signal level changes according to a displacement of said scanning locus in a width direction. apparatus.