JPH0722771Y2 - Optical disk player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an optical disk player, and in particular, is intended to improve the operation during a seek period by a track jump.

B. Outline of the Invention The present invention is an optical disc player for reproducing an optical disc in which a plurality of address information is discretely recorded in the longitudinal direction of a recording track, and a beam spot for information reading is set to one address during a seek period by a track jump. By moving along the information recording area, the address information can be read reliably, and when used in combination with the traverse count, a long jump can be performed with high accuracy and the seek operation can be speeded up. Moreover, it is possible to suppress variations in seek time.

C. Conventional Technology Conventionally, seek operation in an optical disc player has been
The optical pickup is generally performed by a so-called track jump in which the optical pickup is moved at high speed in units of, for example, about 1 to 100 tracks. Further, when performing a rough seek by a long jump of about 100 tracks, the optical pickup is moved while counting the number of tracks through which the beam spot has passed (traverse count) using only the traverse signal, for example. At this time, the tracking servo is in the off state, and the address information recorded on the disc may be readable in some cases, but it is not reliable information and is normally not used even if it is readable.

D. Problem to be solved by the invention However, when the optical pickup is moved only by the traverse count, the accuracy is not so good and the optical pickup reaches a track that is largely different from the target track (address). I will end up. As a result, the target track may not be reached unless a jump of several tens of tracks is performed after the long jump. Therefore, the seek operation takes a long time, and the seek time varies.

Therefore, the present invention has been proposed in view of such a problem, and long jump can be performed with high accuracy, seek operation can be speeded up, and seek time variation can be suppressed. An object is to provide an optical disc player.

E. Means for Solving the Problems In order to solve the above-mentioned problems, the optical disc player according to the present invention reads the above-mentioned address information from an optical disc on which a plurality of address information is recorded in the longitudinal direction of the recording track, and In the seek period in which the information reading means is provided with a tracking adjusting means for adjusting the objective lens for irradiating the optical disc with the information reading light beam in the tracking direction, and the information signal reading means is moved in the radial direction of the optical disc at a high speed. Speed detecting means for generating a signal according to the moving speed, eccentricity detecting means for generating a signal according to the eccentricity of the optical disk, and correction based on the signal according to the eccentricity and the signal according to the moving speed A correction signal calculating means for generating a signal, and the correction signal or the information reading from the correction signal calculating means. Switching means for switching and inputting the tracking error signal from the capturing means to the tracking adjusting means connected to the output end, and the light beam from the information reading means during the seek period is one of the ones on the recording track of the optical disc. A switching signal for controlling switching of the switching means is generated so that the correction signal from the correction signal calculating means is input to the tracking adjusting means from the time when the area slightly before the area where the address information is recorded approaches. And a switching signal generating means.

F. Operation According to the present invention, by moving the beam spot for information reading along the recording area of one address information during the seek period by the track jump, the address information can be read reliably.

G. Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing a main part configuration of an embodiment of an optical disc player according to the present invention. In FIG. 1, an optical disc 1 which is rotationally driven at a constant angular velocity (CAV) has pre-groups, which are, for example, guide grooves, formed in a spiral shape in advance, and land portions between the pre-groups are information recording tracks. Has become. A plurality of address information, which are absolute position information on the disc, are discretely recorded in the longitudinal direction of the recording track. Also,
Since the optical disc 1 is rotationally driven at a constant angular velocity, the address information exists at equiangular intervals.

The optical pickup 2 serves as a tracking adjusting means.
The objective lens 6 has an axis device 3 and is driven in the tracking direction by supplying a signal from the tracking drive circuit 4 to the tracking coil 5.
As a result, the position of the beam spot for reading information is adjusted in the tracking direction. The optical pickup 2 has, of course, a laser diode, a photodetector, an optical system component and the like in addition to the biaxial device 3, but they are not shown here.

The tracking drive circuit 4 is connected to the selection terminal 7a of the changeover switch 7. The selected terminal 7b of the changeover switch 7 is supplied with the tracking error signal T _E based on the output from the photodetector of the optical pickup 2. Further, the selected terminal 7d has a moving speed signal M
A correction signal C _O obtained by adding the _V invert signal and the eccentricity amount signal D _I by the adder 8 is supplied. The selected terminal 7c is open. Here, the moving speed signal M _V is a signal (actually, the moving speed) corresponding to the moving speed of the optical pickup 2 during a seek period by a so-called track jump in which the optical pickup 2 is moved in the radial direction of the optical disc 1 at a high speed. Is a signal obtained by integrating
The moving speed is detected by, for example, a speed detector. The eccentricity amount signal D _I is a signal corresponding to the eccentricity amount of the optical disc 1. The moving speed signal M _V is inverted because the objective lens 6 is driven in a direction opposite to the direction of the moving speed vector V _M of the optical pickup 2, as will be described later. The eccentricity amount signal D _I is not inverted because the eccentricity amount vector V _{D of the} optical disk 1 is not converted.
This is because the direction of is set opposite to the direction of the moving speed vector V _M.

The changeover switch 7 is switched controlled by switching signal S _W. That is, during normal reproduction (reproduction mode), the selected terminal 7b is selected, and the objective lens 6 of the biaxial device 3 is selected based on the tracking error signal T _E.
Are driven in the tracking direction, and tracking servo is performed.

Further, as shown in FIG. 2, the seek period by the track jump in which the direction of the moving speed vector V _M of the optical pickup 2 is set in the radial direction of the optical disc 1, for example, downward in the figure, and the optical pickup 2 is moved at a high speed. In (seek mode), the selected pin is initially open.
7c is selected, and the objective lens 6 of the biaxial device 3 is not driven in the tracking direction. Here, in FIG. 2, the two-dot chain line shows each recording track on the optical disc 1. Also, the eccentricity vector V of the optical disk 1
_In the present embodiment, the direction of _D is set to the opposite direction (upward in the figure) to the direction of the moving speed vector V _M.
Then, the changeover switch 7 is switched from time t _A when the position of the beam spot B _S for reading information from the optical pickup 2 reaches a region slightly before the recording region of one address information on the recording track of the optical disc 1. , The selected terminal 7d is selected, and the objective lens 6 of the biaxial device 3 is driven based on the correction signal C _O. As a result, the beam spot B _S is corrected upward (in the direction of arrow A) in the figure, and moves along the recording area of the one address information starting from the time t _S. Then, at the time t _E when the position of the beam spot B _S reaches the end of the recording area of the one address information, the changeover switch 7 is changed over so that the selected terminal 7c in the open state is selected again. Has become.

Thereby, the beam spot B in the seek period
The locus of _S becomes as shown by the thick solid line in FIG.
One address information on the recording track can be surely read. Therefore, by using it together with the conventional traverse count, for example, a long jump of about 100 tracks can be performed with high accuracy, and the seek operation can be speeded up.
Further, it is possible to suppress variations in seek period.

Next, the operation during the seek period will be described more specifically. First, an example of a circuit for forming a window pulse W _{P which} is a basis for forming a switching pulse S _P described later will be described with reference to a third example.
Description will be given with reference to the drawings. Based on the output from the photodetector of the optical pickup 2 during the seek period
The RF signal S _RF is supplied to the shift register 11. For example, as shown in FIG. 4A, the RF signal S _RF has a structure in which an address mark is provided in advance of the address information and a synchronization signal is provided between them. ROM
The table 12 has the same pattern of information as the address mark, and when it matches the contents of the shift register 11, that is, when the address mark is detected, the output becomes H level (high level). This output is supplied to the counter 14 via the latch circuit 13, and the counter 14 is cleared. The counter 14 includes the shift register
The same clock signal φ as that supplied to 11 and the latch circuit 13 is supplied, and the count values of the clock signal φ are supplied to 15 and 16, respectively. Comparator 15
Is for comparing the count value with a predetermined value corresponding to a time point t _B slightly before the start time point t _S of the address information, and the comparator 16 detects the match value from the count value of the address information. The match is detected by comparing with a predetermined value corresponding to the end time t _E (see FIG. 4). The flip-flop circuit 17 is preset by the coincidence detection output from the comparator 15, and then the comparator 15 is preset.
Cleared by the match detect output from 16. As a result,
The flip-flop circuit 17 outputs a window pulse W _P as shown in FIG. 4 (B).

The window pulse W _P is supplied to a circuit for forming a switching pulse S _P as shown in FIG. 5, for example. In Figure 5, the traverse signal T _R (see FIG. 4 (C)) is supplied to the comparator 21, the traverse signal T _R reference voltage V which is set across the level corresponding to the zero crossing point of the
It is compared with _R1 and V _R2 respectively. The traverse signal T _R
When the level of becomes the level near the zero cross point, both outputs of the comparators 21 and 22 become the H level, and NAND
The output of the circuit 23 becomes L level (low level). This NA
The output of the ND circuit 23 is supplied to the NAND circuit 24 with a negative input terminal. Further, the NAND circuit 24 is supplied with a mirror signal M _I as shown in FIG. 4 (D). This mirror signal M
_I is the RF from the photodetector of the optical pickup 2.
The signal S _RF or the light amount signal is obtained by AC coupling, and the L level portion corresponds to the land portion on the optical disc 1. In the present embodiment, so-called land recording is performed, and therefore, when the position of the beam spot B _S is exactly on the recording track, the NAND is used.
The output of the circuit 24 becomes L level. The output of the NAND circuit 24 is supplied to the NAND circuit 25 with a negative input terminal. Further, the above-mentioned window pulse W _P (fourth
(See FIG. (B)) is supplied. The output of the NAND circuit 25 is output during the period in which the window pulse W _P exists.
At the time when the position of the beam spot B _S just reaches the recording track, that is, at the time t _A when the position of the beam spot B _S approaches the area immediately before the recording area of the address information on the optical disc 1, it becomes L level. . As a result, the flip-flop circuit 26 is preset and the output becomes H level. Before this output becomes H level, no signal for driving the biaxial device 3 of the optical pickup 2 in the tracking direction is supplied, but when it becomes H level, the selector 27 is switched and the moving speed signal M _V A signal based on the correction signal C _O obtained by adding the inversion signal and the eccentricity signal D _I in the adder 8 is supplied to the biaxial device 3. As a result, the position correction of the beam spot B _S is started. The output of the flip-flop circuit 26 is the end time t _{E of the} address information.
Then, the L level is set, the selector 27 is switched, and no signal for driving the biaxial device 3 in the tracking direction is supplied again. That is, the fourth diagram the selector 27 by the switching pulse S _P, as shown in (E) is switching control, the beam spot B _S is to move along a recording region of address information of the beam spot B _S Position correction is performed.

Further, the selector 27 is supplied with a mode identification signal M _D according to the operation mode, and during normal reproduction, a signal based on the tracking error signal T _E is supplied to the biaxial device 3.

Although the above-described embodiment is an example in which the present invention is applied to a so-called continuous groove type optical disc system in which a pre-groove serving as a guide groove is provided on the disc, a sample mark (pit) is used instead of the guide groove. It can also be applied to a so-called sample servo type optical disc system provided with. In this case, for example, the changeover switch or the selector may be changed at the time when the clock pit existing on the center line of the track is read with an appropriate value and before the beam spot enters the address information recording area. .

H. Effect of the Invention According to the optical disc player of the present invention, the tracking adjustment means provided in the optical pickup is driven during the seek period by the track jump, and the beam spot for information reading is set to the recording area of one address information. The address information can be reliably read because it is moved along. Therefore, by using together with the conventional traverse count, a long jump can be performed with high accuracy, the seek operation can be speeded up, and the seek period variation can be suppressed.

Especially, during the seek period, 2
By applying a correction signal to the tracking coil of the axis device, the beam spot is controlled so as to scan the recording track of the optical disk, so that stable address information can be obtained even if disturbance such as vibration is applied to the player itself. Can read.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a main part configuration of an embodiment of an optical disk player according to the present invention, FIG. 2 is a schematic diagram for explaining an operation of the optical disk player of the above embodiment in a seek period, and FIG. FIG. 4 is a block circuit diagram showing an example of a window pulse forming circuit, FIG. 4 is a time chart for explaining the operation, and FIG. 5 is a circuit diagram showing an example of a switching pulse forming circuit. 1 ... Optical disc 2 ... Optical pickup 3 ... 2-axis device 7 ... Changeover switch

Claims (1)

[Scope of utility model registration request] 1. A tracking adjusting means for reading the address information from an optical disc having a plurality of address information recorded in the longitudinal direction of a recording track and adjusting an objective lens for irradiating the optical disc with the information reading light beam in the tracking direction. An information reading means, a speed detecting means for generating a signal according to a moving speed in a seek period in which the information signal reading means is moved in the radial direction of the optical disk at a high speed, and a signal according to an eccentricity amount of the optical disk. Eccentricity amount detecting means for generating, correction signal calculating means for generating a correction signal based on the signal corresponding to the eccentricity amount and the signal corresponding to the moving speed, and the correction signal or the information reading from the correction signal calculating means. Tracking error signal from the means is connected to the output terminal Switching means for switching and inputting to a step, and a point of time during the seek period when the light beam from the information reading means reaches an area on the recording track of the optical disk slightly before the area where one address information is recorded. From the correction signal calculating means, the switching signal generating means for generating a switching signal for controlling switching of the switching means so that the correction signal is inputted to the tracking adjusting means.