JPH02101638A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform a jump operation provided with certainty and high speed by performing jump while evading a header part and performing plural number of times of jump operations in one sector by executing the next jump at a time when setting is performed to a certain degree after performing the preceding jump. CONSTITUTION:A timer 20 connected to a CPU 17 is started up, and the execution of second jump is performed after prescribed time T2. The time T2 is set a t a value in which the setting is performed to the certain degree after turning on a loop switch 14 and the jump can be executed. The second jump is started during performing the operation of the setting completion signal of first jump, however, since track jump is performed by turning off the loop switch 14 and adding a jump pulse, the next jump operation can be performed even without awaiting sure setting. Also, since the total of the turn-on time of the switch of a jump generation circuit 18 and the time T2 is less than the 1/2 of a time between a pre-format part and the next pre-format part, it is possible to surely execute the jump for two times in one sector.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording and reproducing apparatus that records and/or reproduces information by irradiating an optical information recording medium with a light beam.

[Prior Art] Devices that record or reproduce signals using laser light have been put to practical use. For example, there are CDs (compact discs), LDs (laser discs), and the like. In addition, information signals are optically recorded by projecting a light beam onto a disk-shaped recording medium (hereinafter referred to as a disk) that can be recorded, reproduced, and erased using magneto-optical signals on predetermined spiral or concentric tracks. Magneto-optical disk devices for reproducing and erasing information are also being developed.

Usually, these signals are generated by pits (grooves) as shown in Figure 8.
is recorded on disk 1. To read information signals from the disk 1, a light beam (not shown) is projected onto the disk 1 and the pits 2 are read by optical scanning. That is, by scanning the track where bit 2 is formed with a light beam, the intensity of the reflected light changes depending on the presence or absence of the bit, making it possible to optically read the information bit.

FIG. 9 shows the configuration of a disk 3 that can reproduce, record, and erase signals using magneto-optical signals.

In the figure, reference numeral 4 denotes a track guide groove, for example, a spiral groove. The magneto-optical signal is recorded midway between this track guide groove and the adjacent track guide groove. Reference numeral 5 denotes a preformat bit in which a detection pattern such as a track address, a sector address, a sector mark, etc. when a magneto-optical disk is used as data information etc. is dug in the middle of a track guide groove and an adjacent track guide groove. An address is read using preformat bit 5, and data corresponding to the address is reproduced, recorded, or erased using a magneto-optical signal until the next preformat bit 5 in the circumferential direction.

In such a tracking servo system that follows a track using the track guide groove 4 of the disk 3, the reflectance of the disk surface decreases at the location of the preformat bit, and furthermore, the S/N of the tracking error signal decreases.
It becomes a kind of noise.

With this preformat bit, when the servo system is closed at about 4 to 5% of the total track guide groove, the fidelity of track following is reduced, but the servo does not become disconnected.

However, if you want to jump to an adjacent track and play data, for example, first open the tracking servo, then jump to the next track, and then close the tracking servo system when you arrive at a predetermined position. This is the sequence. At this time, it is necessary to increase the gain immediately after the tracking closes to make it easier to pull in the tracking, but if the tracking is closed at the location of the preformat bit, the noise of the preformat bit will also be amplified, making it difficult to pull in the servo. There was a problem with stability.

On the other hand, in order to solve this kind of problem, the applicant proposed in Japanese Patent Application No. 63-40594 a device that avoids the preformatted part and jumps. .

[Problem that the invention seeks to solve] However,
When performing a track jump that avoids such a preformatted part to ensure reliable operation, for example, as will be explained later with reference to Figure 2, it is necessary to ensure that more than half of the sectors are Even though the actual jump operation takes only 1/3 to 115 of a sector, only one jump can be performed per sector and the seek time is long.

[Means for Solving the Problems] The present invention further develops the device of the prior application, and when there is a next jump operation, the jump is performed after reliably waiting for a settling end signal after the previous jump. By executing the next jump after the header has stabilized to a certain extent, it is possible to jump while avoiding part of the header, and to perform multiple jumps in one sector, resulting in reliability and high speed. This is a device that allows you to perform a jumping motion that also functions as a jump motion.

[Examples] Hereinafter, the optical information recording/reproducing apparatus of the present invention will be described in detail based on specific examples.

First, a configuration of an optical system that can be applied to the device of the present invention will be explained in the third section.
As shown in the figure.

In FIG. 3, a laser for reading and writing information in magneto-optical signals is emitted from a laser light source 6, passes through a collimator lens 7 that converts the laser light into parallel light, and is distributed in the disk direction by a polarizing beam splitter (PBS) 8a. , focuses on the magneto-optical disk 3 by an objective lens 9. The reflected light from the disk 3 contains information about the disk,
The light returns to the objective lens 9 and PBS 8a, and is distributed to the detector side. The reflected light distributed to the detector side by the PBS 8a is condensed by a condensing lens 10a to the detector.
, 10b, and one passes through the PBS 8b and is focused on the servo detector 11 for picking up the servo error signal. Also, the other reflected light passes through PBS8b and passes through PBS8c.
R, which picks up magneto-optical signals and pre-pit signals, respectively.
It reaches the FI detector 12a and the RF2 detector 12b.

In the above configuration, signal waveforms of the RFI detector 12a and the RF2 detector 12b are shown in FIG. In FIG. 4, 30 and 31 are preformat signals, and 3
2 and 33 are magneto-optical signals, respectively. As shown in FIG. 4, the magneto-optical signal 32 is
and 3.3 are in reverse phase, and the preformat signals 30 and 3
1 appears in phase. Therefore, the magneto-optical signal is RF1F1
The preformat signal is obtained as a differential signal between the signal 13a and the RF2 signal 13-b, and the preformat signal is obtained from the RFI signal 13-a and the RFI signal 13-a.
It is obtained by adding the F2 signal 13-b.

Next, a detection means for detecting a preformatted portion using an RF multiplied signal will be explained with reference to FIGS. 5 and 6.

Figure 5 is a diagram showing the preformat detection circuit, and Figure 6 shows the preformat detection circuit.
The figure shows the signals of each part.

In FIG. 5, first, the RFI signal 13-a and the RF2 signal 13-b are added by the adding amplifier 14-a. As mentioned above, since the magneto-optical signals 32 and 33 have opposite phases, the magneto-optical signals cancel each other out, leaving only the preformat signal (the signal is shown at 15-a in FIG. 6).

Next, the comparator 14-b determines the noise level and 15
The signal is binarized at approximately half the peak level of the signal -a (15-b in FIG. 6).

Finally, with the one-shot multivibrator 14-C,
Waveform shaping is performed to obtain the waveform 15-0 in FIG.

Next, FIG. 1 shows a block diagram of a tracking servo system of an optical information recording/reproducing apparatus according to the present invention. In the figure, a servo detector 11 uses laser light to detect the amount of deviation of the disk 3 from the track guide groove as a tracking error signal.

The tracking error signal is amplified to a target gain by an amplifier circuit 12, and compensated by a phase compensation circuit 13 so that a target phase margin is obtained. The loop switch 14 is a switch that opens or closes the tracking servo, and is left open during track jumps. The drive circuit 15 is for driving the actuator 16 in a direction in which the target seat becomes smaller using the tracking error signal, and the servo operates when the loop switch 14 is closed.

The CPU 17 is a processor that controls the above-mentioned tracking servo system, takes in the output signal of the preformat detection section 19, and controls the ON/OFF of the loop switch 14 and the ON/OFF of the jump pulse generation circuit. It is something to return to.

FIG. 2 is a timing chart of a conventional example, and shows that the preformat detection output obtained as shown in FIG. 6 is used to jump while avoiding the preformat portion.

When accessing a target track, the track is skipped by a track jump, but the CPU 17 continues to monitor the signal of the preformat detection output 21-a, and after confirming that the preformat part has passed, starts the servo. The loop switch 14 is turned OFF and opened (21-b in FIG. 2). Subsequently, the jump generation circuit is activated to perform a jump (21-c).

The tracking error signal is as shown in 21-d, and the drive signal is as shown in 21-e. The settling end signal 21-e is applied to the window comparator output of the tracking error signal.
It has a time constant of 1. T is determined by selecting the time from when the signal reaches the threshold value of the window comparator until it is reliably settled and reaches the state before the track jump. In a system with poor stability, it is necessary to set the time T for a long time.

Next, the timing of the embodiment of the present invention will be explained using FIG. 22-a to 22-f are respectively 2 in FIG.
1-a to 21-f. The explanation is the same as in FIG. 2 up to the point where the preformat is avoided and the first jump is performed. Subsequently, in the second jump, the next jump is executed without waiting for the settling end signal 22-e to fall.

To start the second jump, turn off the first jump switch, start the timer 20 connected to the CPU 17 in FIG. 1, wait for time T2, and then start the second jump. Move. T2 is the loop switch 20-
After turning on b, let it settle to a certain extent, and then set it to a value that is safe for the next jump. The start of the second jump is triggered by the settling end signal 22- of the first jump.
T of e is in operation, but the track jump operation turns off the loop switch 22-b and jumps by adding a jump pulse, so you can perform the next jump operation without waiting for it to stabilize. obtain. Furthermore, even if you add the time the jump generation circuit switch 22-C is ON and the time T2, it does not take up to 1/2 of the time to reach the preformat part and the next preformat part. Can perform two jumps.

In the above embodiment, the jump operation is performed after the preformat portion has passed, but the timing is not limited to this. For example, if the jump operation takes longer than the preformat portion, the preformat portion is As soon as a part is detected, it is possible to perform a jump motion without overlapping, stably, and in a short time.

Further, in the embodiment described above, the jump operation is performed twice per sector, but the jump operation is not limited to this, and the jump operation may be performed three times or more.

Furthermore, in the above embodiment, the preformat detection section 19 was provided separately, but in actual equipment, the preformat detection section is always required when reading an address, so the RF signal processing system is Since the RF signal processing circuit is included in the circuit, it is possible to configure the present invention by using the output signal from the RF signal processing circuit.

[Effects of the Invention] As explained above, according to the optical information recording/reproducing apparatus of the present invention, by avoiding part of the header during track jump operation, it is possible to improve the stability of the tracking servo system, and also to improve the stability of the tracking servo system. By performing multiple track jumps within one sector, it has become possible to achieve high speed.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a timing chart diagram of a conventional embodiment, Fig. 3 is a configuration diagram of an optical system of an embodiment of the present invention, and Fig. 4 is an RF signal output waveform. 5 is a diagram showing a preformat detection circuit, FIG. 6 is a diagram showing output signal waveforms of each part in FIG. 5, FIG. 7 is a timing chart diagram of an embodiment of the present invention, and FIG. 8 is a diagram showing a preformat detection circuit. 9 is a diagram showing the appearance of a conventional disk such as CD%LD, and FIG. 9 is a diagram showing the appearance of a magneto-optical disk. 11-m-servo detector, 12-m-amplifier circuit, 13-m-phase compensation circuit, 14-m-loop switch, 15-m-drive circuit, 16--actuator, 17--CPU. 18-m-Jump pulse generation circuit, 19-m-Brief format detection section.

Claims (1)

[Claims] (1) Using an optical recording medium in which tracks divided into a plurality of sectors by preformatted parts such as addresses are arranged in parallel, the tracks are traced with a light beam while performing tracking control to record information and and/or an optical information recording/reproducing device which performs reproduction and performs a jump operation between tracks with a light beam while avoiding the preformat section when accessing a desired track; The optical information recording and reproducing apparatus is characterized in that the next jump operation is started without waiting for the tracking control operation to settle, thereby performing a plurality of jump operations between one sector.