JPH0798931A - Optical recorder and recording and reproducing device - Google Patents

Abstract

PURPOSE:To accurately and stably detect rotation start position information(phase) on a disk plane even without improving the relative mounting accuracy of an optical head and a rotation start position mark signal detector and to control the start of recording or reproduction by using the information. CONSTITUTION:A D-latch 19 detects phase difference between a rotation start mark signal detected by a detector 7 and formed on a disk 1 and an address signal detected by the optical head 11. When it is judged that a state enters a lock state by a lock detector 9, a switch controller 8 switches a switch 6 toterminal (b). Consequently, the input on one side of a phase comparator 5 becomes the output signal of a decoder 21, therefore, the pull-in of a rotating phase of a disk motor 2 is performed again. Hereinafter, the rotating phase control of the disk motor 2 is performed so that the frequency and phase of the output of a reference separation circuit 4 that is the prescribed point of an external video signal and that of the decoder 21 can be matched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording device and a recording / reproducing device, and more particularly to an optical device for controlling recording start or reproduction start by using a rotation start position mark signal for positioning the rotation start end. Recording apparatus and recording / reproducing apparatus.

[0002]

2. Description of the Related Art A conventional optical recording device is disclosed in Japanese Patent Laid-Open No. 58-58
As described in JP-A-62831 and JP-A-58-97136, a rotation start end position mark detector different from an optical head equipped with a laser used for recording and reproducing is used. , The rotation start end position mark signal required for performing the rotation start end positioning is detected.

This rotation start position mark detector is composed of a light emitting diode and a detector composed of elements such as a phototransistor.

According to this conventional apparatus, the disk is rotated in synchronization with the output of the rotation start end position mark detector and the external video signal, and the video signal is recorded on the disk.

[0005]

As described above, when the rotation start end position mark signal is detected by using the rotation start end position mark signal detector and recording is performed by synchronizing this with the video signal, There is a problem that the accuracy of the position of the signal in which the external image signal is actually recorded on the disk is largely controlled by the relative mounting accuracy of the optical head and the rotation start position mark signal detector.

The problem will be described with reference to FIG. Figure 2
Shows the relative relationship between the rotation start end position mark signal detector and the disk when viewed from the side surface of the disk.

In FIG. 2, reference numeral 1 is a disk, and 7 is a rotation start end position mark signal detector. 33 and 33
Reference numeral ′ indicates the locus of the optical axis emitted from the rotation start end position mark signal detector 7. Reference numeral 33 indicates a disk when the light is irradiated perpendicularly to the disk 1 surface. The locus | trajectory of an optical axis when it inclines in the direction opposite to a rotating direction, and is irradiated is shown.

As is apparent from the figure, the rotation start end position mark signal detector 7 obtains from the rotation start end position mark signal detector 7 when the optical axis is vertical and when the optical axis is tilted. When the output signal is inclined, it means that the phase of the delayed portion on the disk surface is actually detected. on the other hand,
The disk motor that rotates the disk 1 is controlled by an error signal that compares the phase of a predetermined point of the external video signal with the output of the rotation start end position mark signal detector 7 to synchronize the external video signal and the disk phase. To be Therefore, looking at the time relationship between the external video signal and the actual disc rotation phase in this case, when the optical axis of the rotation start end position mark signal detector 7 is mounted perpendicular to the disc 1 surface, As shown in FIG. 3 (a), the disc rotation start end position P1 on the disc 1 surface coincides with the external video signal predetermined reference point P2, but when it is attached at an angle, as shown in FIG. Will be detected after P2.

For this reason, the optical axis of the laser light emitted from the optical head for actually recording the external image signal on the disk surface is mounted vertically and at the same position, while the rotation start position mark signal is detected. If the optical axis of the device 7 is tilted and attached, the phase of the video signal recorded on the disc surface will also be recorded out of phase with each other.

In the above case, the case where the optical axis of the rotation start end position mark signal detector 7 is tilted in the tangential direction of the disk is considered, but when the optical head is tilted or the rotation start end. Even when the relative positional relationship between the position mark signal detector 7 and the optical head is deviated, the phase shift as described above occurs.
Therefore, when the recording device is fixed for recording on one disc, the problem is relatively small. However, when recording is performed on one disc by changing the recording device, the phase of the video signal is different from that of the recording device. There is a problem that the recording is shifted with each change.

As a means for solving such a problem, it is conceivable that the mechanical accuracy of the relative positional relationship between the optical head and the rotation start end position mark signal detector is extremely improved. There is a problem that the device becomes expensive. It is also possible to use the optical head itself to detect the phase of the address signal, etc., recorded on the disk surface in advance without using the rotation start position mark, to control the disk rotation phase. Due to the dropout caused by the laser beam, the search, etc., the motor control is disturbed and the laser light must always be projected onto the disk surface.

The present invention has been made in order to eliminate the above-mentioned problems, and the object of the present invention is to improve the relative mounting accuracy between the optical head and the rotation start end position mark signal detector. An object of the present invention is to provide an optical recording device and a recording / reproducing device capable of accurately and stably detecting the rotation start position information (phase) of the disk surface and controlling the recording start or the reproduction start by using this. .

[0013]

As shown in FIG. 1, the above-mentioned object is to detect a rotation start end position mark signal of the disk 101, and a recording information to the disk 1.
01 recording means 103, means 109 for detecting and recording the phase difference between the rotation start position mark detected by the detector 104 and the address signal detected by the address signal phase detector 108, and Means 110 for phase-shifting the rotation start position mark signal based on the phase difference to create a corrected rotation start position mark signal, means 105 for separating the reference signal from the recorded information, and means 105
Means 106 for phase-comparing the reference signal output from the detector, the rotation start end position mark signal before correction detected by the detector 104, and the rotation start end position mark signal after correction output from the means 110. Means 107 for determining the phase lock based on the output of the means 106, and the means 10
According to the determination result of No. 7, means 111 for switching the signal connected to the means 106 from the rotation start end position mark signal before correction to that after correction, and a disk motor whose rotation phase is controlled by the output of the means 106. This is achieved by

[0014]

The disk position and phase information obtained from the recording means 103 (optical head) and the disk position and phase information obtained from the rotation start end position mark signal detector 104 are phase-compared only when the system is started up, thereby rotating the optical head and the optical head. It operates to detect and store a relative mounting error of the start position mark detector. Next, according to the stored error signal, the disc rotation start end position mark signal detector 104
Output signal is phase-shifted, and the rotation phase of the disk 1 is controlled again using this signal. by this,
The disk rotation start phase is matched with the disk surface phase information read by the optical head regardless of the variation in the relative mounting position of the rotation start detector with respect to the optical head, and the influence of dropout of address signals etc. You can avoid receiving it.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the embodiments of the present invention, a typical example of the currently proposed optical disk format will be described with reference to FIG.

FIG. 4 (a) shows the case where the address signal is formed at two places per one rotation of the optical disk. As shown in the figure, the optical disc 1 is composed of a track portion 202 composed of a groove-shaped guide track, address signal portions 203 and 204 of the track formed on the guide track, and a rotation start end position mark 205. Address signal section 203,
204 is formed in a region forming an angle α with the center of the optical disc 1. In addition, the rotation start end position mark 205
Is inside the guide track 202, but may be outside the guide track 202.

The track address signals recorded in the address signal sections 203 and 204 are formed as uneven bits in the form of a modulation signal such as FM modulation or PE modulation. On the other hand, the rotation start end position mark 205 is formed by cutting the optical disc, and is detected as a difference in reflectance by the light emitting diode for detecting the rotation start end position mark and the phototransistor.

Next, FIG. 4B shows an example of another optical disc format, showing a case where there is one address signal portion per one rotation of the optical disc. Other than this, it is the same as or equivalent to FIG.

FIG. 4 (c) shows still another example of the optical disk format, showing an example in which there is one address signal portion per one rotation of the optical disk and the rotation start end position mark is not formed. In this example, the light from the light emitting diode for detecting the rotation start position mark is transmitted to the optical disc 1
The inner peripheral portion of the address signal portion 203 is detected to detect the difference in reflectance between the address signal portion 203 and other portions, and the inner peripheral portion of the address signal portion 203 plays the same role as the rotation start position mark.

Next, an embodiment of the present invention will be described with reference to the drawings. Here, in the disk format shown in FIG. 4B, a rotation start position mark signal detector 7 (light emitting diode and phototransistor) and an optical head 11 are attached to the optical disk rotation direction as shown in FIG. The case will be described. FIG. 6 shows a block diagram of an embodiment of the present invention, and FIGS. 7 and 8 show signal waveforms or timing charts of respective parts of the block diagram. Note that the reference numerals in FIG. 6 and the reference numerals in FIGS. 7 and 8 are associated with each other.

In FIG. 6, 1 is an optical disk and 2 is a disk motor. The disk motor 2 starts to rotate when a disk start command (FIG. 8 (W)) output from a microcomputer that controls the system is applied to the disk drive circuit 3. For example, when the signal of FIG. 8 (W) becomes a high level, it starts.

The external video signal is input to the reference signal separation circuit 4, and predetermined points of the video signal are separated. The predetermined point differs depending on the format of the external video signal to be recorded or the number of screens of information recorded per one rotation of the optical disk. For example, when the external video signal to be recorded is a TV signal and one screen is recorded for one rotation of the optical disc, a so-called frame signal generated at one timing per one screen, such as the vertical synchronization signal of the first field, is generated. In many cases, the predetermined point is separated from the video signal.

It serves as one input of the output phase comparator 5 of the reference signal separation circuit 4 and serves as a reference for controlling the rotational phase of the disk motor 2. The signal selected by the switch circuit 6 is input to the other side of the phase comparator 5.

The rotation start position mark detector 7 is composed of a light emitting diode, a phototransistor, etc., as described above, and detects the rotation start position mark previously recorded on the optical disk 1. Here, the rotation start end position mark portion has a high signal, and the other portions have a low signal (FIG. 7B).
This output is connected to one of the switch circuits 6, and is also connected to a set terminal of a counter circuit 16, a load terminal of a programmable down counter 20 and a decoder circuit 21 which will be described later.

Since the switch circuit 6 is connected to the fixed terminal a by the output signal of the switch control circuit 8 (Y in FIG. 8) at the start of rotation of the optical disk 1, the rotation start end position mark detection output is selected. Phase comparator 5
Is input to the other. Here, the output (Y) of the switch control circuit 8 connects the switch 18 to the fixed terminal d by H,
The switch 6 is connected to the fixed terminal b. At L, it is connected to the fixed terminal on the opposite side.

The phase comparator 5 performs a phase comparison between a predetermined point of the external video signal separated by the reference separation circuit 4 and the rotation start end position mark detection output, and the phase comparator 5
Is output to control the rotational phase of the disk motor 2 via the disk drive circuit 3. As a result, the external video signal and the rotation phase of the optical disc 1 are synchronized.

Therefore, at the beginning of rotation of the optical disk 1, control is performed so that the output of the reference signal separation circuit 4 and the frequency and phase of the output of the rotation start end position mark signal detector 7 match.

The phase lock detector 9 receives the phase error signal which is the output of the phase comparator 5 as an input, and the phase error signal has become sufficiently small, that is, the predetermined point of the external video signal and the rotation start end position mark signal. It is detected that the phase difference of the detector 7 has become sufficiently small, and it is determined that the rotation phase of the optical disk 1 is phase locked to the external video signal.

The output of this phase lock detector 9 (see FIG. 8)
(X) is transferred to the optical head operation signal generation circuit 10 (generally constituted by a microcomputer controlling the system) and the switch control circuit 8. Figure 8
In (X), the H level indicates the phase locked state and the L level indicates the unlocked state. The optical head operation signal generation circuit 10 outputs a signal in various cases in order to correspond to various operations, but here, only operations related to the present invention will be described. In the present invention, the circuit 10 detects that the phase lock detector 9 is in the first phase lock state after the rotation start of the optical disk 1 (a in FIG. 8 (X)), and operates the optical head 11. A signal (FIG. 8 (Z)) is output.
As a result, the optical head 11 generates light from the light source attached to the optical head 11, and the optical disk 1
It is controlled so that the light beam is correctly irradiated on the surface of. The H level in FIG. 8 (Z) shows the operating state of the optical head.

The optical head 11 is used when recording and reproducing a video signal. When recording an external video signal,
An external video signal that has been appropriately modulated is input and input to the optical head 1 through a circuit (not shown). The optical head 1 outputs a light beam having an intensity according to the external video signal. The light beam is applied to the surface of the optical disc 1, and the video signal is recorded on the surface of the optical disc 1. on the other hand,
When reproducing a signal recorded on the optical disc 1, the optical head 1 emits a light beam weaker than that at the time of recording.
Irradiate the surface. Then, the reflected light is detected and the information on the surface of the optical disc 1 is reproduced.

When the external video signal is recorded on the optical disk 1, the light reflected from the optical disk 1 is received again by the optical head 11, converted into an electric signal, and then sent to the preamplifier 12 to be sent to the optical disk 1. The address information previously recorded on the No. 1 surface is reproduced.

The output of the preamplifier 12 is connected to the address signal separation circuit 13 to separate the address signal previously recorded on the disc, and the waveform shaping circuit 14 performs envelope detection and the like to make the address signal portion high. A pulse is generated (FIG. 7 (C)). The pulse generation in the address signal portion is described in detail in JP-A-58-97136, page 4, upper right row, line 17 to lower left row, line 6. Here, the pulse signal indicating the address signal portion corresponds to the address signal section pulse.

From the above, it can be understood that the rising edge portion of the output of the waveform shaping circuit 14 becomes the predetermined phase of the optical disk 1 read by the optical head 11 itself.

Next, in the counter circuit 16, as described above, the output signal of the rotation start end position mark signal detector 7 is input to the reset input of the high frequency oscillator 17 (see FIG. 7).
(D)) is connected to its clock input. Therefore, the counter circuit 16 counts the number of pulses of the high frequency oscillator output (FIG. 7 (D)) in synchronization with the rising edge of the output of the rotation start position mark signal detector 7 (FIG. 7 (B)). The output of the counter 16 is sent to the data input of the D-latch 19.

The clock input of the D-latch 19 is a signal indicating the address signal portion which is the output of the waveform shaping circuit 14 via the switch circuit 18 which is initially connected to the fixed terminal C shown in FIG. 7 (C). ) Has been sent. Therefore, the D-latch 19 receives the rotation start position mark signal (see FIG. 7).
The number of pulses (here, N) of the high-frequency oscillator output (FIG. 7D) which is the clock input of the counter 16 from the rising of (B)) to the rising of the signal indicating the address signal portion (FIG. 7C). ) Is latched at the rising edge of the signal indicating the address signal portion, and the signal indicating the next address signal portion (C)
This content is held until the arrival of (FIG. 7 (F)).

Next, the programmable down counter 20 receives the output of the D-latch 19 as its data input,
The rotation start position mark signal (FIG. 7B) is input as the data load input, and each signal of the output of the high frequency oscillator 17 is input as the clock input. Therefore, the programmable down counter 20 is loaded with the number latched in the D-latch 19 as data in synchronization with the rising edge of the rotation start end position mark signal (N in this case),
From this number, the pulses of the high-frequency oscillator 17, which is a clock input, are down-counted, and at the end of N counts, borrow (carrying down) signals G1, G2, G3, ... (FIG. 7).
(G)) occurs.

After that, until the rotation start position mark signal arrives again, the borrow signal is generated every 2 ^m of the count number by the bit number m of the programmable down counter 20. The output of the programmable down counter 20 is shown in FIG. 7 (G) (provided that the binary counter is used).

The decoder circuit 21 receives the borrow output (FIG. 7 (G)) of the programmable down counter 20 and the first pulse G1, G2, G3 of FIG. 7 (G) after the arrival of the rotation start position mark signal (B). ... is selected and output (Fig. 7
(I)). Therefore, the rising output (FIG. 7 (I)) of the decoder circuit 21 has the same timing as the rising timing of FIG. 7 (C) which is a signal indicating the address signal portion read by the optical head 11. In summary,
By the counter 16 and the D-latch 19, FIG.
(B) and (C) Phase comparison of both signals is performed, and a signal obtained by shifting the signal of FIG. 7B by the output of the D-latch 19 is created by the programmable down counter 20 and the decoder circuit 21. You can

Output of the decoder circuit 21 (FIG. 7 (I))
Becomes one input of the switch circuit 6. The switch control circuit 8 outputs the output of the phase lock detection circuit 9 (see FIG.
(X)) is connected. The switch control circuit 8 is
After the disk motor rotation is started and the output state of the phase lock detection circuit 9 first changes, the state is changed after an appropriate time has elapsed, and the state is maintained until the rotation of the optical disk is stopped.

Switch circuit 6 and switch circuit 18
Are connected to fixed terminals a and c from the start of the optical disk rotation described above until the state of the switch control circuit 8 changes, respectively, and the rotation start end which is the output of the rotation start end position mark signal detector 7 respectively. The position mark signal and the address signal partial pulse output from the waveform shaping circuit 14 are selected. On the other hand, at the H level after the change of the state of the switch control circuit 8 (FIG. 8 (Y)), the switch circuit 6 and the switch circuit 18 have fixed terminals b,
d and are respectively switched to the output of the decoder circuit 21 and the ground. Therefore, after the switching, the clock input of the D-latch 19 is stopped and the data before the state change of the switch control circuit 8 is held. In other words, the phase comparison of the rotation start end position mark signal and the signal indicating the address signal portion is performed in the period of (a) to (i) of FIG. 8 (X), and the result of the phase comparison is stored. .

As a result, the result of phase comparison between FIGS. 7B and 7C is held until the switch control circuit 8 changes again (until the rotation of the optical disk 1 is stopped).
Therefore, after the state of the switch control circuit 8 changes, D-
Based on the number held in the latch 19 (N in this case), the decode circuit output (FIG. 7 (I)) is created every time the rotation start position mark signal arrives. As a result, thereafter, without reading the address signal by the optical head 11, it is possible to generate a signal at the same timing as the rotation start position mark signal (B).

On the other hand, in the disk motor 2, since the input of the switch 6 is switched, one input of the phase comparator 5 becomes the output signal of the decoder 21, so that the rotational phase of the disk motor 2 is pulled again. (FIG. 8 (X) C). Note that in FIG. 8 (X), the output of the phase lock detector 9 becomes unlocked at the portion (a) because the input of the phase comparator 5 shown in FIG. 6 is switched to the output of the reference separation circuit 4. This is because the rotational phase of the disk is re-engaged so that the output of the decoder 21 is matched.

Thereafter, the rotational phase control of the disk motor 2 is controlled so that the frequency and phase of the output of the reference separation circuit 4 which is a predetermined point of the external video signal and the output of the decoder 21 are matched. Further, the output of the switch control circuit 8 is output from the optical head operation signal generation circuit 10 (see FIG.
After (Y)) changes its state, a signal for returning the optical head 11 to the standby state again is output, and the optical head 11 remains in the standby state until the next operation command from the microcomputer or the like arrives. After the step of FIG. 8 (X), the output signal of the optical head operation signal generation circuit 10 (see FIG.
(Z)) will be governed by a command from the microcomputer (for example, start recording).

According to the configuration of the embodiment, the output of the rotation start position mark signal detector 7 is corrected by the phase information of the optical disk 1 surface detected by the optical head 11 which actually records an external video signal or the like. Even if the accuracy of attaching the rotation start position mark signal detector 7 to the optical head 11 is not increased, the rotation start position on the surface of the optical disk 1 can be aligned with the reading phase of the optical head 11.

Further, in this case, since the rotation start end position mark signal detector 7 always detects the rotation start end position mark on the inner circumference of the disc in a constant state, a stable optical disc which is not affected by the dropout of the address signal portion or the like. The effect is to position the rotation start end of.

In the above embodiment, the case where the detection timing of the rotation start end position mark signal is slightly earlier than the address signal portion detection timing is considered, but the above timing may be replaced. In this case, the number of stages of the counter 16 and the number of bits of the D-latch 19 increase.

When the detection of the rotation start end position mark signal and the address signal are almost the same, for example, in the case of FIG. 9, the waveform shaping circuit 14 and the switch 18 as shown in FIG.
It is solved by inserting a delay circuit between the two.

FIG. 10 shows a block diagram, and FIG. 11 shows waveforms and timing charts of respective parts. Here, the operation of the components different from the above-described embodiment will be described.

The delay circuit 15 delays the signal (FIG. 11C) showing the address signal portion, which is the output of the waveform shaping circuit 14, by a fixed amount and outputs it. The output signal waveform of the delay circuit 15 is as shown in FIG. This fixed delay output corresponds to the signal (C) indicating the address signal portion described with reference to FIG. 7, and if the output signal of the delay circuit 15 (FIG. 11 (J)) is used, the same operation as in the above embodiment is performed. It is clear that Therefore, even in this case, the optical disc 1 is not required to be mounted on the optical head 11 without increasing the accuracy of mounting the rotation start position mark signal detector 7.
The rotation start end positioning on the surface can be matched with the reading phase of the optical head 11.

Further, it is possible to control the phase at which recording information is started to be recorded on the recording medium based on the phase difference between the rotation start end position mark signal and the address signal. Further, even when the information recorded on the recording medium is reproduced, the phase at which reproduction is started can be controlled based on the phase difference.

Next, a second embodiment of the present invention will be described. In the first embodiment, the case where the address signal forming portion is one place per one rotation of the disk is considered.
In the case of the disc format as shown in FIG.
The block diagram shown in FIG.

Now, it is assumed that the rotation start position mark signal detector 7 and the optical head 11 have the positional relationship shown in FIG. FIG. 14 shows waveforms and timing charts of respective parts of the block in FIG. 13 in this case. Here, the operation of the components different from those of the embodiment described with reference to FIGS. 6 and 7 will be described.

In the second embodiment, since the frequency of the signal portion indicating the address signal portion is doubled, as shown in FIG. 13, the output of the rotation start end position mark signal detector 7 and the waveform shaping circuit. A selection circuit 22 having 14 as an input is provided, and the output of the selection circuit 22 is input to the switch circuit 18. The waveform shaping circuit 14 outputs two address signals per one rotation of the disk as shown in FIG. 14C, but the selection circuit 22 outputs the rotation start position mark signal (FIG. 14B). ) Only the signal indicating the first address signal portion after generation is selected and output (FIGS. 13 and 14).
(K)). When the signal (K) is used instead of the signal (C) shown in FIG. 7, the same effect as that of the first embodiment can be obtained.

Next, a third embodiment of the present invention will be described. This embodiment shows the case of the disk format as shown in FIG. 4C, that is, the case where there is one address signal portion per one rotation of the optical disk and the rotation start position mark is not formed. In this embodiment, the inner peripheral portion of the address signal portion is detected by a detector of the same kind as the rotation start end position mark signal detector provided separately from the optical head,
Although this is the point of the rotation start end, it is clear that if the output of this detector is replaced with the rotation start end position mark signal of FIG. 7B, the same shaping and effect as the first embodiment can be obtained. is there.

[0055]

According to the present invention, even if there is variation in the mounting accuracy of the rotation start position mark signal detector with respect to the optical head, the disk surface phase information and the rotation start position mark detected by the optical head at the beginning of system startup. The phase difference of the output of the signal detector is detected and stored, and thereafter, the disk surface phase information detected by the optical head is restored from the rotation start position mark signal based on the phase difference storage output, and the disk rotation start position can be determined. it can. Therefore, since the mounting accuracy of the rotation start position mark signal detector may be rough,
This has the effect of significantly reducing the time required for the mounting process, and thus of reducing the manufacturing cost. Further, since the rotation start end position mark can be detected without being affected by the dropout of the address signal or the like, it is possible to stably improve the positioning accuracy of the rotation start end (recording start point) on the disk surface. A phase at which recording information is started to be recorded on the recording medium based on a phase difference between the rotation start position mark signal detected by the rotation start position mark signal detector and the address signal detected by the optical head, Alternatively, it becomes possible to control the phase at which reproduction is started.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a configuration of the present invention.

FIG. 2 is an explanatory diagram of a problem of the conventional device.

FIG. 3 is an explanatory diagram of a problem of the conventional device.

FIG. 4 is a diagram showing a typical example of a conventional optical disc format.

FIG. 5 is an explanatory diagram of an optical disc format according to the first embodiment of the present invention.

FIG. 6 is a block diagram of a first embodiment of the present invention.

FIG. 7 is a time chart of signals of main parts of FIG.

FIG. 8 is a time chart of signals of main parts of FIG.

FIG. 9 is an explanatory diagram of an optical disc format according to an application example of the first embodiment.

FIG. 10 is a block diagram of the application example.

FIG. 11 is a time chart of the signal of the main part.

FIG. 12 is an explanatory diagram of an optical disc format according to a second embodiment of the present invention.

FIG. 13 is a block diagram of the second embodiment.

FIG. 14 is a time chart of the signal of the main part.

[Explanation of symbols]

1, 101 ... disk, 2, 102 ... disk motor,
5, 106 ... Phase comparator, 7, 104 ... Rotation start position mark signal detector, 11, 103 ... Optical head (recording means), 105 ... Reference signal separating means, 109 ... Phase difference storing means, 110 ... Phase shifting means , 111 ... Switching means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Nishizawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock company Hitachi Image Information Systems (72) Inventor Chiharu Takayama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Hitachi Imaging Information System (72) Inventor Masashi Sasaki 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Inside the Hitachi Imaging Information System

Claims (2)

[Claims] 1. An optical recording apparatus comprising a rotation start end position mark signal detector and an optical head, wherein the rotation start end position mark signal detected by the rotation start end position mark signal detector and the rotation start end position mark signal An optical recording apparatus, wherein a phase difference from an address signal detected by an optical head is detected, and a phase at which recording information is started to be recorded on a recording medium is controlled based on the phase difference. 2. An optical recording / reproducing apparatus comprising a rotation start end position mark signal detector and an optical head, wherein the rotation start end position mark signal detected by the rotation start end position mark signal detector Optical recording / reproducing, characterized in that a phase difference from an address signal detected by the optical head is detected, and a phase at which reproduction of information recorded on a recording medium is started based on the phase difference is controlled. apparatus.