JPH10143873A - Optical disk reproducing device and optical pickup control method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly, correctly and stably move a light spot to the track posi tion of a prescribed address of a layer different from the layer being accessed at present at the time of reproducing information from an optical recording medium having recording layer of two or more layers by an optical pickup. SOLUTION: In a first mode, whether either a focus jump or a track jump is to be executed at first is selected according to the mode of the light spot of an optical pickup 2 and other physical condition. Moreover, in a second mode, when the focus jump is performed after the tack jump, since the accelerating or the decelerating of a spindle motor can be performed simultaneously with the track jump when the accelerating or the decelerating of the spindle motor is need, a time before the spindle motor reaches a prescribed speed is manage to be shorter as compared with a method performing the track jump after performing the focus jump.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus or an optical disk reproducing apparatus for reproducing a signal from a disk-shaped recording medium, and more particularly to a signal from an optical recording medium such as a DVD having two or more recording layers. The present invention relates to an optical disc reproducing apparatus including an improvement in a movement of a light spot between layers and a movement between tracks by a light beam for reproducing a light beam.

[0002]

2. Description of the Related Art Generally, in this type of information recording / reproducing apparatus, tracking control and focus control of an optical head are performed, and data is accurately written and read during recording and reproduction. Such control is performed by controlling the optical head by a so-called servo control circuit. As a method of generating a tracking error signal used for tracking control of an optical head, a three-beam method and a phase difference method (phase difference detection method: DPD method) are generally put into practical use. These methods are described in, for example, "Compact Disc Reader", pp134-138 (Showa 57), published by Ohmsha, and JP-A-61-230637. Various types of disc-shaped optical recording media have been developed.
In addition to the (compact disk), a plurality of types such as a CD-ROM, a video CD, and a DVD (digital versatile disk) have been put to practical use. Until now, all optical recording media that have been put to practical use have a single recording layer.
The VD has a configuration in which two 0.6 mm layers are bonded together, and information is read from two recording layers by a single optical pickup located on one side of the disk.

[0003]

In an optical disk reproducing apparatus for reproducing information from an optical recording medium having a plurality of layers, a light beam emitted from a single optical pickup is directed to an objective lens by using an objective lens. The signal reading can be started by focusing on a target track of the layer and obtaining a light spot. By the way, the user of the optical disc reproducing apparatus changes the reproducing program,
When a request such as a high-speed search in the same program occurs, it is necessary to move the light spot to another track in the same layer or to a predetermined track in another layer. In the case of a single-layer optical recording medium such as a conventional CD, it is sufficient to move only between tracks. However, in the case of a disk having two or more layers, it is necessary to use an interlayer of an optical spot to access another layer. You also have to move. In order to quickly perform such interlayer movement, it is necessary to perform a so-called focus jump that instantaneously changes the focal length of the objective lens of the optical pickup. However, a simple combination of the conventional inter-track movement (track kick or track jump or track search) and focus jump can quickly or stably access a desired track position in another target layer. Did not.

Accordingly, the present invention relates to an optical disk reproducing apparatus for reproducing information from an optical recording medium having two or more recording layers, wherein a light spot by a light beam from an optical pickup is quickly and accurately formed on a target layer. It is an object of the present invention to provide an optical disk reproducing device capable of moving to a target track and an optical pickup control method in the optical disk reproducing device.

[0005]

In order to achieve the above object, according to a first aspect of the present invention, when it is necessary to move a light spot from a current layer to another layer, a track jump means firstly sets a target layer on a target layer. A first method of moving the light spot to the target layer by the focus jump means after moving the light spot to the vicinity of the track of the current layer corresponding to the target track, and the first method of moving the light spot to the target layer by the focus jump means After moving the light spot to the layer, it is determined by a predetermined condition which of the second methods of moving the light spot to the target track of the target layer by the track jump means is adopted,
According to the result, the movement of the light spot is executed by one of the first method and the second method. here,
The predetermined condition may be, for example, (1) whether the determined moving direction of the light spot is from the outer circumference to the inner circumference or from the inner circumference to the outer circumference, or (2) the determined moving direction of the optical spot is the optical disk. (3) a type in which the first and second layers of the optical disc have the same address, or a different address. Type.

In order to achieve the above object, according to a second aspect of the present invention, when it is necessary to move the light spot from the current layer to another layer, the light spot is first moved to the target track of the target layer by the track jump means. After the light spot is moved to the vicinity of the track of the corresponding current layer, the light spot is moved to the target layer by the focus jump means (fixed to the first method of the first aspect). .

In order to achieve the above object, in a third aspect of the present invention, when it is necessary to move the light spot from the current layer to another layer, a direction to be moved is detected by the track jump means, and the light spot is moved. When the moving direction is from the outer circumference to the inner circumference, the rotation speed of the spindle motor is accelerated, and when the moving direction is from the inner circumference to the outer circumference, the rotation speed of the spindle motor is reduced.

In order to achieve the above object, according to a fourth aspect of the present invention, when it is necessary to move a light spot from the current layer to another layer, the number of tracks to be moved and the direction to be moved of the light spot are detected. When the number of tracks to be moved is equal to or more than a predetermined number and the moving direction of the light spot is from the outer circumference to the inner circumference, the rotation speed of the spindle motor is accelerated. When the number is greater than or equal to the number and is from the inner circumference to the outer circumference, the rotation speed of the spindle motor is reduced.

In order to achieve the above object, in a fifth aspect of the present invention, the optical pickup is controlled by combining the first aspect with the third aspect or the fourth aspect.

In order to achieve the above object, in a sixth aspect of the present invention, an optical pickup is controlled by combining the second aspect with the third aspect or the fourth aspect.

In order to achieve the above object, in a seventh aspect of the present invention, the optical pickup is controlled by combining the second method in the first aspect with the third or fourth aspect.

That is, according to the present invention, an optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light;
A servo control unit that controls the optical pickup using the reflected light to perform tracking servo control of the light beam and focus servo control; and a light spot where the light beam is focused on the first layer and the second layer. Current layer determining means for determining which position is located; focus jump means for moving the light spot of the light beam from the current layer to another target layer; and the position of the focused light spot of the light beam Current track number detecting means for detecting a track number to be moved, track jumping means for moving the light spot of the light beam from the current track to another target track, and moving the light spot from the current layer to another layer When necessary, the track jump means corresponds to the target track of the target layer first. A first method in which the light spot is moved to a target layer by the focus jump means after the light spot is moved to the vicinity of the track in the layer, and the light is first moved to the target layer by the focus jump means. A control method determining means for determining which method of the second method of moving the light spot to a target track of a target layer by the track jump means after moving the spot, There is provided an optical disc reproducing apparatus having a light spot control means for executing the first method or the second method determined by the control method determination means.

According to the present invention, an optical disk for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and reading the information by an optical pickup for detecting reflected light is provided. A method of controlling an optical pickup of a reproducing apparatus, a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; When the light spot needs to be moved to another layer, the light spot is first moved to the vicinity of the track of the current layer corresponding to the target track of the target layer by the track jump means, and then the target is moved by the focus jump means. A first method for moving the light spot to a layer, and the light spot to a target layer by the focus jump means. After moving, a control method determining step of determining which of the second methods of moving the light spot to a target track of a target layer by the track jumping means is adopted. An optical pickup control method is provided.

According to the present invention, an optical disk for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and reading the information by an optical pickup for detecting reflected light is provided. A method of controlling an optical pickup of a reproducing apparatus, a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; When the light spot needs to be moved to another layer, first, the light spot is moved to the vicinity of the track of the current layer corresponding to the target track of the target layer by the track jump means. Moving the light spot to a layer to be formed. It is.

Further, according to the present invention, an optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and the optical recording medium A spindle motor for rotating and driving the spindle motor;
Spindle motor control means for obtaining V; servo control means for controlling the optical pickup using the reflected light to perform tracking servo control of the light beam; focus servo control; and a light spot focused on the light beam. Current layer determining means for determining which of the first layer and the second layer is located; focus jump means for moving a light spot of the light beam from the current layer to another target layer; Current track number detecting means for detecting a track number at which a focused light spot of a beam is located; track jumping means for moving the light spot of the light beam from a current track to another target track; and the track jumping means A light spot moving direction detecting means for detecting a direction to be moved by,
When the moving direction of the light spot detected by the light spot moving direction detecting means is from the outer circumference to the inner circumference, the spindle motor control means accelerates the rotation speed of the spindle motor during a focus jump, An optical disc reproducing apparatus is provided which has an acceleration / deceleration means for controlling the spindle motor control means to reduce the rotation speed of the spindle motor at the time of a focus jump when moving from the inner circumference to the outer circumference.

Further, according to the present invention, an optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and the optical recording medium A spindle motor for rotating and driving the spindle motor;
Spindle motor control means for obtaining V; servo control means for controlling the optical pickup using the reflected light to perform tracking servo control of the light beam; focus servo control; and a light spot focused on the light beam. Current layer determining means for determining which of the first layer and the second layer is located; focus jump means for moving a light spot of the light beam from the current layer to another target layer; Current track number detecting means for detecting a track number at which a focused light spot of a beam is located; track jumping means for moving the light spot of the light beam from a current track to another target track; and the track jumping means A light spot moving direction detecting means for detecting a direction to be moved by,
Moving track number detecting means for detecting the number of tracks to be moved by the track jumping means; and the number of tracks to be moved detected by the moving track number detecting means being a predetermined number or more, and the light spot moving direction detecting means When the moving direction of the light spot detected is from the outer circumference to the inner circumference, the spindle motor control means accelerates the rotation speed of the spindle motor at the time of a focus jump, while the movement track number detection means When the detected number of tracks to be moved is equal to or more than a predetermined number and is directed from the inner circumference to the outer circumference, the acceleration / deceleration for controlling the spindle motor control means to reduce the rotation speed of the spindle motor during a focus jump. And an optical disk reproducing apparatus having the means.

According to the present invention, an optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and the optical recording medium A spindle motor for rotating and driving the spindle motor;
Spindle motor control means for obtaining V; servo control means for controlling the optical pickup using the reflected light to perform tracking servo control of the light beam; focus servo control; and a light spot focused on the light beam. Current layer determining means for determining which of the first layer and the second layer is located; focus jump means for moving a light spot of the light beam from the current layer to another target layer; A current track number detecting means for detecting a track number at which a focused light spot of the beam is located; a track jumping means for moving the light spot of the light beam from a current track to another target track; When it is necessary to move from the current layer to another layer, the track jump means first A first method of moving the light spot to a target layer by the focus jump means after moving the light spot near a track of a current layer corresponding to a target track of the target layer; Any of the second methods of moving the light spot to a target track of the target layer by the track jumping means after first moving the light spot to the target layer by the means A light spot control means for executing the first method or the second method determined by the control method determination means, and a direction to be moved by the track jump means is detected. Light spot moving direction detecting means, and a moving method of the light spot detected by the light spot moving direction detecting means When the direction is from the outer circumference to the inner circumference, the spindle motor control means accelerates the rotation speed of the spindle motor at the time of focus jump, while when the flow is from the inner circumference to the outer circumference, the spindle motor control means is There is provided an optical disc reproducing apparatus having acceleration / deceleration means for controlling the rotation speed of the spindle motor to be reduced at the time of a focus jump.

Further, according to the present invention, an optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and the optical recording medium A spindle motor for rotating and driving the spindle motor;
Spindle motor control means for obtaining V; servo control means for controlling the optical pickup using the reflected light to perform tracking servo control of the light beam; focus servo control; and a light spot focused on the light beam. Current layer determining means for determining which of the first layer and the second layer is located; focus jump means for moving a light spot of the light beam from the current layer to another target layer; A current track number detecting means for detecting a track number at which a focused light spot of the beam is located; a track jumping means for moving the light spot of the light beam from a current track to another target track; When it is necessary to move from the current layer to another layer, the track jump means first A first method of moving the light spot to a target layer by the focus jump means after moving the light spot near a track of a current layer corresponding to a target track of the target layer; Any of the second methods of moving the light spot to a target track of the target layer by the track jumping means after first moving the light spot to the target layer by the means A light spot control means for executing the first method or the second method determined by the control method determination means, and a direction to be moved by the track jump means is detected. Moving spot detecting means for detecting the number of tracks to be moved by the track jumping means; And click the number of detection means,
The number of tracks to be moved detected by the moving track number detecting means is equal to or more than a predetermined number, and the moving direction of the light spot detected by the light spot moving direction detecting means is from the outer circumference to the inner circumference. When the spindle motor control means accelerates the rotation speed of the spindle motor at the time of a focus jump, the number of tracks to be moved detected by the moving track number detection means is equal to or more than a predetermined number, and An optical disc reproducing apparatus is provided which has an acceleration / deceleration means for controlling the spindle motor control means to decelerate the rotation speed of the spindle motor at the time of a focus jump when the head is moving toward.

Further, according to the present invention, during normal reproduction, CL
An optical pickup which is rotated by a spindle motor whose rotation speed is controlled to be V, irradiates a disk-shaped optical recording medium having information recorded on the first and second layers with a light beam, and detects reflected light A method of controlling an optical pickup of an optical disc reproducing apparatus for reading out the information, wherein a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; Detecting the direction in which the light spot is to be moved, and, when the light spot needs to be moved from the current layer to another layer, when the direction in which the light spot should be moved is from the outer circumference to the inner circumference. During the focus jump, accelerate the rotation speed of the spindle motor,
On the other hand, when moving from the inner circumference to the outer circumference, a step of controlling the rotation speed of the spindle motor to be reduced at the time of the focus jump, and when it is necessary to move the light spot from the current layer to another layer, First moving the light spot to the vicinity of the track of the current layer corresponding to the target track of the target layer by the jump means, and then moving the light spot to the target layer by the focus jump means. An optical pickup control method is provided, comprising:

Further, according to the present invention, during normal reproduction, CL
An optical pickup which is rotated by a spindle motor whose rotation speed is controlled to be V, irradiates a disk-shaped optical recording medium having information recorded on the first and second layers with a light beam, and detects reflected light A method of controlling an optical pickup of an optical disc reproducing apparatus for reading out the information, wherein a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; Detecting the direction in which the light spot should be moved; detecting the number of tracks on which the light spot should be moved; and detecting the movement when the light spot needs to be moved from the current layer to another layer. If the number of tracks to be moved is equal to or more than a predetermined number and the direction in which the light spot should move is from the outer circumference to the inner circumference, the focus When the detected number of tracks to be moved is equal to or more than a predetermined number and moves from the inner circumference to the outer circumference, the rotation speed of the spindle motor is accelerated during a focus jump. Controlling the speed to decelerate, and when it is necessary to move the light spot from the current layer to another layer, first by a track jump means, near the track of the current layer corresponding to the target track of the target layer There is provided an optical pickup control method, comprising: moving the light spot; and thereafter, moving the light spot to a target layer by a focus jump unit.

According to the present invention, during normal reproduction, CL
An optical pickup which is rotated by a spindle motor whose rotation speed is controlled to be V, irradiates a disk-shaped optical recording medium having information recorded on the first and second layers with a light beam, and detects reflected light A method of controlling an optical pickup of an optical disc reproducing apparatus for reading out the information, wherein a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; Detecting the direction in which the light spot is to be moved, and, when the light spot needs to be moved from the current layer to another layer, when the direction in which the light spot should be moved is from the outer circumference to the inner circumference. During the focus jump, accelerate the rotation speed of the spindle motor,
On the other hand, when moving from the inner circumference to the outer circumference, a step of controlling the rotation speed of the spindle motor to be reduced at the time of a focus jump; and Light moving the light spot to a target layer by a jump means, and then moving the light spot to a target track of the target layer by a track jump means. A pickup control method is provided.

Further, according to the present invention, during normal reproduction, CL
An optical pickup which is rotated by a spindle motor whose rotation speed is controlled to be V, irradiates a disk-shaped optical recording medium having information recorded on the first and second layers with a light beam, and detects reflected light A method of controlling an optical pickup of an optical disc reproducing apparatus for reading out the information, wherein a current layer determining step of determining whether the focused light spot of the light beam is located on the first layer or the second layer; Detecting the direction in which the light spot should be moved; detecting the number of tracks on which the light spot should be moved; and detecting the movement when the light spot needs to be moved from the current layer to another layer. If the number of tracks to be moved is equal to or more than a predetermined number and the direction in which the light spot should move is from the outer circumference to the inner circumference, the focus When the detected number of tracks to be moved is equal to or more than a predetermined number and moves from the inner circumference to the outer circumference, the rotation speed of the spindle motor is accelerated during a focus jump. Controlling the light spot to decelerate, and when the light spot needs to be moved from the current layer to another layer, first moving the light spot to a target layer by a focus jump means; Moving the light spot to a target track of a target layer.

[0023]

Embodiments of the present invention will be described below with reference to the drawings, together with preferred embodiments. FIG. 2 is a block diagram showing one embodiment of the optical disk reproducing apparatus according to the present invention. This optical disk reproducing apparatus reproduces information from a read-only type DVD, which is a kind of the optical recording medium 1, and uses a read-only two-layer type DVD. It should be noted that the present invention is applicable not only to a playback apparatus dedicated to DVDs, but also to a conventional music CD or video C.
It can be configured to also be used as a playback device such as a D or CD-ROM. In the following embodiment, an optical disk reproducing apparatus as a CD / DVD reproducing apparatus will be described.

In the case of such a CD / DVD reproducing apparatus, what kind of type of the loaded disc 1 is,
By adding a function to identify whether the disc is a D-layer, a single-layer DVD, or a double-layer DVD, it is possible to set parameters in the reproducing apparatus according to the loaded disc and perform subsequent processing. Become. FIG. 6 is a circuit diagram showing an optical pickup (PU) 2 in FIG. 2 and an arithmetic unit (part of the preamplifier 5 in FIG.
5 shows an example of a circuit for selecting one of two types of tracking error signals in accordance with the result of the type determination.

In FIG. 2, a motor driver / tracking / focus control circuit 4 controls the disk 1 to be rotated at a CLV (constant linear velocity) by a spindle (SP) motor 3. A signal read from the disk 1 by the optical pickup (optical head) 2 is supplied to a preamplifier 5, and an output signal thereof is supplied to a digital servo (DSV) control circuit 6. The system controller 7 exchanges signals with the preamplifier 5 and the digital servo control circuit 6 to control the entire optical disc reproducing apparatus, and has a microcomputer, not shown, that is, a CPU, a memory, an interface, and the like.

The output signal of the digital servo control circuit 6 is supplied to a motor driver / tracking / focus control circuit 4, which controls the rotation of the spindle motor 3, the tracking servo control of the optical pickup, and the focus servo control. The DSV 6 includes a variable speed controller / memory controller / EFM demodulation circuit / error correction circuit and the like in addition to the servo control circuit, and also has a function of transmitting a reproduction signal using a memory (not shown). The optical pickup 2 can be moved in the radial direction of the disk 1 by a traverse motor (not shown), and the objective lens is moved along the focus direction, that is, along the optical path, by a focus servo control mechanism (not shown) and an actuator included in the tracking servo control. It can move in the direction and radial direction of the disc. The light spot is moved in the radial direction of the disk by using both the traverse motor and the actuator. The former moves a large distance (for example, several hundred tracks or more), while the latter moves a short distance. Used for

The optical pickup 2 also has a laser diode for irradiating the disk 1 with a laser beam, and outputs a signal obtained by reproducing optical information recorded on the disk 1 based on the reflected light. As shown, signals A to D for detecting a focus error signal FE by an astigmatism method and for detecting a tracking error signal by a phase difference method, and two types of signals E for detecting a tracking error signal TE of a three-beam method, A plurality of photodetectors A to F
F (A to F indicate both the plurality of photodetectors and their output signals). These signals are supplied to a preamplifier 5 where necessary calculations are performed.

In FIG. 6, the optical pickup 2 includes four divided optical sensor portions A, B, C,
D and optical sensor portions E and F used for the three-beam method are schematically shown. FIG. 6 shows an arithmetic unit which responds to output signals from these optical sensor portions. The adder 10 adds and outputs the output signals of the photosensor portions A and C on the diagonal line, and the adder 12 adds the output signals of the photosensor portions B and D on the other diagonal line. Output. The adder 14 adds the output signals of the adders 10 and 12 to each other. The subtracters 16 and 20 both add the output signal of the adder 10 to the output signal of the adder 10.
The second output signal is subtracted. Also, the subtractor 18
Is for subtracting the output signal of the optical sensor portion F from the output signal of the optical sensor portion E.

The circuit shown in FIG. 6 utilizes the circuit shown in FIG. 4 of JP-A-57-74837.
Gate circuits 36 and 40 controlled by output signals of a falling pulse generating circuit 32 and a rising pulse generating circuit 34 responsive to an output signal of the adder 14, respectively,
, And hold circuits 38,
42. Output signals of the hold circuits 38 and 42 are supplied to + and-input terminals of a subtractor 44, respectively, and an output signal of the subtractor 44 is supplied to a terminal on one side of the switch 30. The output signal of the adder 14 is LPF
28 and an equalizer (EQ) 46, respectively, and are output as a sum signal (sum all (SA) signal), an EFM signal or an EFM plus signal.

Therefore, the control signal CONT from the microcomputer of the system controller 7 causes the switch 30
When the side is selected, the tracking error signal TE of the three-beam method is output, and when the side is selected, the same as that shown in FIG. 4 of the above-mentioned Japanese Patent Application Laid-Open No. 57-74837 is used. A tracking error signal is selected.
This tracking error signal is obtained by sampling the difference signal (the output signal of the subtractor 16) at both edges (the output signals of the falling pulse generating circuit 32 and the rising pulse generating circuit 34) of the sum signal (the output signal of the adder 14). This is equivalent to obtaining a value obtained by adding a sign according to the direction of deviation of the beam spot from the track to the momentary peak-to-peak value of the difference signal (see FIG. 5 of the publication).

The output signal of the subtracter 20 is supplied to a known focus servo control system and the tracking error signal TE is supplied to a known tracking servo control system so as to be used as a focus error signal FE. The sum signal SA is a main signal for reading the recorded information of the disc, and also a measurement target signal for disc type discrimination described later. Note that the sum signal SA is output via the LPF 28 in order to remove a high-frequency component that may be included in the sum signal SA. The system controller 7
Discrimination of the disc type and control of the optical pickup are performed by a later-described operation of a microcomputer (not shown).

Next, a bifocal type optical pickup 2, that is, an objective lens having two converging points as shown in JP-A-7-65407 and JP-A-7-98431, is provided with two focusing points. A method for discriminating the type of a disc using a disc that can be used for different discs will be described. The optical pickup 2 has NA = 0.38 mm
And a spot of NA = 0.6 mm, two types of discs, ie, a CD having a plate thickness of t1 = 1.2 mm and t2 = 0.
It is assumed that information is read from a 6 mm DVD. The distance between the two focal points is 0.3 mm. If an image is formed simultaneously on the disk surface and the signal surface, the disk surface is affected by low-frequency modulation and offset, so that the distance between the two focal points cannot be set in the same manner as the disk thickness.

FIG. 3 is a diagram showing a state of focusing a laser beam on the disk 1 in such a bifocal optical pickup. 1-a is a disk with t1 = 1.2 mm, 1-b is t2 =
0.6-mm disc, 1-c indicates the focusing state on a dual-layer disc (interlayer distance t3 = 40 μm) with one layer being 0.6 mm, the leading upper beam is for 1.2 mm, and the trailing lower beam is The side beam is for 0.6 mm. In FIG. 3, α, β, γ, δ
Indicates the respective states in which the objective lens of the optical pickup 2 has moved in the focus direction. FIG. 4 shows various signal waveforms obtained from output signals when a focus search is performed by the optical pickup 2 corresponding to FIG. That is, the vertical axis in FIG. 4 is voltage, the horizontal axis is time, and p
Indicates a peak. The bifocal optical pickup is composed of a hologram lens.
Although signals are detected in addition to the two spots having two focal points as in Japanese Patent Publication No. 1, signals other than the two-focus detection signal are omitted here.

4-a to 2-d in FIG. 4 are the same as 1-a in FIG.
For 2-mm thick disks, 2-e to 2-h are for 0.6-mm thick disks of 1-b in FIG. 3, and 2-i to 2-l are for 1-c in FIG.
0.6 mm thick × two-layer type disc. Further, the sum signal SA in FIG. 6 corresponds to 2-a, 2-e, 2-i in FIG.
The signal obtained as a result of comparing the sum signal SA with the threshold indicated by the dotted line is shown in FIG. 4 as 2-b, 2-f, and 2-j.
It is. Further, when the frequency characteristic of the equalizer 46 in FIG. 6 is flattened, the EFM signals shown in FIG.
It is. Further, the signal obtained as a result of comparing the EFM signal with the threshold shown by the dotted line is 2-d, 2-h, 2-l in FIG.
It is.

Here, 1.2 mm for two focal points
The upper spot of the thick disc and the lower spot of the 0.6 mm thick disc are the original reproduced signals, and the output of this portion contains high frequency components schematically indicated by a plurality of vertical lines in the waveform diagram. ing. On the other hand, the spot which does not correspond to the original reproduction signal is in a state where the light spot is blurred due to the spherical aberration, and it can be seen that the output signal therefrom does not contain a high frequency component.

The focus search is performed by increasing or decreasing a voltage applied to a focus coil of the optical pickup 2 to move an objective lens which is a part of the optical system of the optical pickup 2 along an optical path. In the waveform 2-a in FIG. 4, the peak on the left side in the figure is obtained in the state α of the disk 1-a in FIG. 3, and the peak on the right side is obtained in the state β in the same manner. Thus, the peaks in FIG. 4 correspond to α and β in FIG.
The four peaks at -i to 2-l correspond to α, β, γ, and δ of the disk 1-c in FIG. FIG. 5 is a waveform diagram showing a focus search in a two-layer disc.
The case where the servo control is turned on in the second layer of the 6 mm recording layer is shown. 3-a is a voltage applied to the focus coil, and 3-b to 3-e are waveforms corresponding to, for example, 2-i to 2-l in FIG.

In FIG. 4, the portion where the thin lines are dense indicates the high frequency component HF. In FIG. 5, 9-a is the voltage applied to the focus coil, and 9-b is the sum signal S.
A, 9-c is the focus error signal, 9-d is the sum signal SA
9-e is a signal obtained by comparing the focus error signal (FE) 9-C with a predetermined threshold, and 9-f is a signal obtained by comparing the EFM signal with the comparator 5.
A signal obtained by comparison with the reference value Ref at 0, 9-g is HFDET (the output signal of the D-FF 56) in FIG. The timing SC in the waveform 9-e indicates the time when the focus servo control is turned on.

FIG. 7 shows the output signal of the circuit of FIG.
FIG. 3 is a block diagram illustrating an example of a circuit that detects a high-frequency component HF using A and an EFM signal. The EFM signal is output from the comparator 5
0 and compared with the reference signal Ref. Sum signal S
A is applied to the D input of a D-FF (flip-flop) 52, its Q output is applied to the D input of the next stage D-FF 54, and its Q output is further applied to the D input of the next stage D-FF 56. The Q output is output as a detection signal HFDET. The output signal of the comparator 50 is each D-FF 52-5.
6 clocks. Reset is each DF
F52 to 56 are reset signals.

The output signal of the comparator 50 in the circuit of FIG. 7, that is, the signal after the comparison of the EFM signal is shown as 9-f in FIG. The D-FFs 52 to 56 count pulses of the output signal of the comparator 50 only when the signal 9-d formed by shaping the waveform of the sum signal SA is H (high level). Output signal HF of FF56
DET 9-g becomes H. If three counts cannot be performed within this interval, the counter including the D-FFs 52 to 56 is reset by the sum signal SA or the like. In this example, three counts are used, but this count can be set to a predetermined number as appropriate.

FIG. 8 is a block diagram showing another example of a circuit for detecting a high-frequency component HF using an EFM signal in the output signal of the circuit of FIG. The EFM signal is provided to the comparator 60 via the HPF 58, and is compared with the reference signal Ref.
The output of the comparator 60 is provided as a clock for the D-FF 62, and its Q output is output as a detection signal HFDET. A predetermined value is always given to the D input of the D-FF 62. Reset is a reset signal for the D-FF 62. The circuit of FIG. 8 extracts a high-frequency component HF of the EFM signal and compares the extracted high-frequency component HF with a reference value Ref to latch a signal obtained. It should be noted that other configurations than those shown in FIGS. 7 and 8 can be used as long as they detect high-frequency components.
A PF may be provided.

As a circuit example of the equalizer 46 in FIG. 6, for example, a 5-tap transversal filter can be used. The delay time T and the tap gains G0 to G4 of the unit delay elements constituting this filter can be controlled using data stored in advance in a program ROM of a controller (not shown) according to the type of the disk. As an example of T, T = 44 for a 1.2 mm CD
In the case of a DVD of 0 ns and 0.6 mm, T = 80 ns can be switched. Examples of G0 to G4 include:
G2 = 1, G1 = G3 = 0.1 for 1.2 mm CD
2, G0 = G4 = 0, and G for a 0.6 mm DVD
0 = 0.02, G1 = 0.2, G2 = 1, G3 = 0.
2, G4 = 0.02, and at the time of focus search, G2 = 1 to remove frequency characteristics, and the other values are set to 0.

The operation of the configuration obtained by combining FIGS. 6 and 7 will be described. After turning on the power of the reproducing apparatus, the spindle (SP) motor 3 is started to start the focus search. That is, the voltage applied to the focus coil is
9-a, the sum signal SA is A / D-converted and taken into a microcomputer, and the sum signal SA (FIG. 5)
9-b) is read, and the output signal HFDE of FIG.
Monitor T (9-g in FIG. 5).

When sum signal SA exceeds a predetermined value and signal HF
DET becomes H, and the focus error signal (9-c in FIG. 5)
) Is compared with a predetermined value, and the signal 9-e is monitored. When the signal 9-e changes from H to L (low level), the focus servo control is performed at the time t (corresponding to almost the zero cross point of the so-called S curve in the focus search). Is turned on. Also,
Various parameters of the reproducing apparatus due to the difference in reflectivity of each disk, for example, laser power of an optical head, a focus error signal, a gain of a circuit for generating a tracking error signal, an offset, a balance, a delay time of a unit delay element,
A tap gain is set, and a reproduction process is executed.

The above operation will be described with reference to the flowchart of FIG. It is assumed that this flow starts when the power of the reproducing apparatus is turned on, the disc is exchanged, or when data reproduction of another layer is required in a multi-layer disc. After initialization such as clearing predetermined contents of a memory or a buffer not shown in step S20,
In step S21, a focus search is started. Thereafter, the voltage of the sum signal SA is read and stored in a register,
A comparison with a predetermined value is performed. In the next step S23, the sum signal S
It is determined whether or not A is greater than a predetermined value Q. If YES, it is determined in step S24 whether or not the leading edge (front edge) of the sum signal SA has been detected. If “NO” in the step S23, the process returns to the step S22. If an edge of the sum signal SA is detected in step S24, the count C of the counter is incremented by one in step S25, and the process returns to step S22. On the other hand, step S24
If the edge of the sum signal SA is not detected in step S26, it is determined in step S26 whether HFDET is at H. NO
Returns to step S22 if YES, step S if YES
The signal of FIG. 5 obtained by shaping the focus error signal FE at 27
It is determined whether or not the trailing edge 9-e is detected.

When the edge of the focus error signal FE is detected, it is determined in step S28 whether or not the count C is 1, and if it is 1, it is determined that the loaded disk is a CD, and the disk is suitable for the CD. The parameters are set in step S29, and then, in step S34, the focus servo control is turned on at time SC (see waveform 9-e) when the signal 9-c in FIG. 5 becomes the center value. If C = 1 is not satisfied, it is determined in step S30 whether C = 2. If C = 2, it is determined that the disc is a single-layer DVD disc, and parameters suitable for the disc are set in step S31, and then step S34 is performed. To turn on the focus servo control as described above. If not C = 2, it is determined in step S32 whether or not C = 3.
It is determined that the layer is the layer, and a parameter suitable for the layer is set in step S33. Then, in step S34, the focus servo control is turned on as described above. Thereafter, a normal reproduction operation is started in step S35. The disc type can be determined by the number of counts C as shown in FIG. 4 because the number of peaks of the sum signal SA (2-a, 2-e, 2-i in FIG. 4) obtained during the focus search. And the timing at which the high-frequency component in the EFM signal is detected has a certain relationship depending on the type of disc.

[0046]

<First Embodiment> Next, a first embodiment of the present invention will be described with reference to FIG. In the first mode, one of the following two methods is selected and executed when moving the light spot. == First method == When it is necessary to move to another layer,
First, a light spot is moved (track jump) to a currently accessed track corresponding to a target track of a target layer, and then a focus jump is performed to a target layer (FIGS. 10B and 10D). == Second method == When it is necessary to move to another layer,
First, a focus jump is performed to a target layer, and then a light spot is moved (track jump) to a target track of the target layer (a and c in FIG. 10).

In FIG. 1, it is first determined in step S1 whether or not there is a search request. The search request here occurs when another location is accessed from a predetermined track of the currently accessed layer. Next, step S2
Then, it is determined whether the destination access point is in the same layer as the current location. This can be determined by comparing the current address with the destination address and referring to the TOC data. Since the address is provided with a layer identification code indicating which of the first layer and the second layer is the track (layer), when the address is read, the position of the layer and the disk in the radial direction can be known. If the destination access point is in the same layer as the currently accessed location, the process according to the present invention is not particularly necessary, so the flow goes to step S3, and the search is executed in the same manner as in the related art. Therefore, the processing after step S3 is not shown.

[0048]

If the destination access point is in a different layer, it is determined in step S4 whether the first method or the second method is selected. For this determination, one of the following conditions applies. [Judgment Conditions for Selection of First Method and Second Method] (1) Whether the moving direction of the light spot to be obtained is from the outer circumference to the inner circumference or from the inner circumference to the outer circumference of the optical disc. The first method is selected when moving from the current position to the inner circumference, and the second method is selected when moving from the current position to the outer circumference. In the second method, since no signal is read from the track during the focus jump, a speed signal cannot be obtained, and therefore, the spindle motor cannot be controlled. It takes time to make it work. In particular, in the CLV, the rotation speed of the inner circumference is higher than that of the outer circumference, so that moving from the outer circumference to the inner circumference requires more time than the reverse, so this determination condition is used. (2) It depends on whether the moving direction of the light spot to be obtained is from the first layer to the second layer of the optical disc or from the second layer to the first layer. When going from the first layer to the second layer, the first method is selected, and when going from the second layer to the first layer, the second method is selected. (3) It depends on whether the first and second layers of the optical disc have the same address (type 1 disc) or have different addresses (type 2 disc). The first method is selected for types having the same address, and the second method is selected for types having different addresses. FIG. 11 schematically shows Type 1 and Type 2 discs, where L0 indicates the first layer and L1 indicates the second layer. In the figure, “30000h” indicates a specific example of the address of the innermost periphery of the data area. In this embodiment, the first layer means the outer layer closer to the optical pickup of the two layers of the disc, and the second layer means the inner layer farther from the optical pickup. (4) It depends on physical factors. For example, when the signal quality of the first layer is lower than that of the second layer due to a large jitter or a scratch, or when the recording density is different, the first method and the second method are combined, and the length is generally increased. A track jump, which is a distance movement, is always performed on the second layer side. For example, when moving from the innermost circumference or the outermost circumference, when moving to the innermost circumference or the outermost circumference, or when overrunning the end track, runaway may occur. Therefore, the switching is performed in consideration of the current position or the target position. (5) It depends on the type of data to be reproduced. For example, if control data is recorded on the first layer and main data such as images and sounds are recorded on the second layer, a long-distance track jump must always be performed on the first layer where the control data is located. Control data can be read when a track is kicked.

[0049]

In step SS4 in FIG. 1, the above determination conditions are not shown, but specific methods of the first method and the second method will be described below. [First Method] When the first method is selected in step S4, steps S5 to S12 are executed. In step S5, the current address is read, and the difference from the address corresponding to the destination access point in the currently accessed layer is calculated. From this address difference, it is known whether the radial direction to be moved is toward the outer circumference or the inner circumference, and the number of tracks to be moved is known. In step S6, the tracking servo control is temporarily turned off and the optical pickup 2 is controlled to move the light spot to the target track (track jump) using the information obtained in step S5. At this point, the movement of the light spot in the radial direction of the disk is as rough as about ± several tracks.

When the movement of the light spot in the radial direction of the disk 1 is started, the counting of the number of crossed tracks is started. Also, the spindle motor 3 is controlled so that the light spot has a CLV (constant linear velocity) with respect to the access point.
Is controlled. In step S7, it is determined whether or not the count value of the number of tracks matches the calculated value obtained in step S5. If the count value matches, the brake is applied to reduce the moving speed, the tracking servo control is turned on, and then step S8 Perform a focus jump to move to the target layer.
Focus jump means that both the focus servo control and the tracking servo control are turned off, acceleration is performed in the focus direction so that the light spot moves instantaneously from the first layer to the second layer or vice versa. This refers to moving the focus position in the thickness direction of the disc by applying a brake when a curve is detected.

After the focus jump, the focus servo control is turned on (the servo control loop is closed) in step S9, and the tracking servo control is similarly turned on in step S10. Here, the current address is read in step S11. This address may be the address of the target access point, but the addresses often do not match due to the influence that the eccentricity of the spiral track differs between layers. In order to accurately access the target address, the number and direction of tracks to be further moved are calculated in step S11.
In step 2, this information is used to kick the target track precisely. Note that a track kick refers to a short radial movement of the disk, while a track jump refers to a long radial movement of the disk. The above is the contents of the processing of the first method.

Since the spindle motor 3 is CLV controlled,
When moving the disk in the radial direction, it is necessary to control acceleration or deceleration depending on the moving direction. DVDRO
In a case where a high-speed search is required by M or the like, since the inertia of the disk 1 is large, a large time loss occurs in the convergence of the speed of the spindle motor 3 on the target track. Therefore, when moving to another layer, by setting the acceleration / deceleration value of the spindle motor 3 by CLV control as soon as possible along with the track movement, the target rotation speed can be achieved in the shortest time. After that, the speed of the spindle motor 3 can quickly converge to the target speed while the target layer is accurately moved to the target track by kicking. Note that it is a preferable embodiment to include such quick control of acceleration / deceleration of the spindle motor 3 in step S6. This quick control of acceleration / deceleration of the spindle motor 3 is shown as steps S30 to S33 in the flowchart of FIG. 13 showing a third mode and a fourth mode, which will be described later. can not touch.

[Second Method] When the second method is selected in step S4, steps S13 to S18 are executed, and thereafter, the flow returns to step S10 constituting the first method. Steps S13 to S15 are steps S8 to S10
In step S13, a focus jump is performed to move to the target layer. After the focus jump, the focus servo control is turned on in step S14, and the tracking servo control is similarly turned on in step S15. The next steps S16 to S18 are steps S5 to S5.
In step S16, the current address is read, and the difference between the current address and the address corresponding to the destination access point in the currently accessed layer is calculated in step S16.
From this address difference, it is known whether the radial direction to be moved is toward the outer circumference or the inner circumference, and the number of tracks to be moved is known.

In step S17, the optical pickup 2 is controlled to move the light spot to the target track (track jump) using the information obtained in step S16. At this point, the movement of the light spot in the radial direction of the disk is as rough as about ± several tracks. When the movement of the optical spot in the radial direction of the disk 1 is started, the counting of the number of tracks that have been moved is started. Further, the spindle motor 3 is controlled so that the light spot becomes CLV with respect to the access point. In step S18, it is determined whether or not the count value of the number of tracks matches the calculated value obtained in step S16. If they match, step S10
Steps S12 to S12 are performed in the same manner as in the first method.

FIG. 10 is a diagram schematically showing the first method and the second method. In FIG. 10, L0 indicates a first layer and L1 indicates a second layer. The movement of the light spot is indicated by an arrow, ps is the first access point of the light spot,
p1 and p2 indicate the subsequent movement of the light spot in numerical order, and pe indicates the final arrival point (the target track of the target layer). 10b and 10d show the first method, a and c show the second method, respectively.

<Second Aspect> In the first aspect, the first method and the second method are selected under predetermined conditions, and the optical pickup is controlled using either of them. In the second mode, such selection is not performed, and only the first method is used. FIG. 12 is a flowchart showing the processing of the second mode, and the same steps as those in FIG. 1 have the same contents. That is, FIG. 12 shows steps S4, S4 in FIG.
13 is different from FIG. 1 in that points S13 to S18 are deleted, and the process proceeds directly from step S2 YES to step S5.

<Third Aspect> and <Fourth Aspect> Next, a third aspect and a fourth aspect of the present invention will be described. As described above, since the spindle motor 3 is controlled by CLV, when the disk is moved in the radial direction, it is necessary to control acceleration or deceleration depending on the moving direction. DVD
If you need a high-speed search in ROM, etc.,
Since the inertia of the disk 1 is large, a large time loss occurs in the convergence of the speed of the spindle motor 3 on the target track. Therefore, when performing a focus jump to another layer, the radial direction of the disk to be moved is determined, and the acceleration / deceleration value of the spindle motor 3 is set and applied according to the direction and distance (the number of tracks) to be moved. By performing the focus jump at the same time as or near the same time, the speed of the spindle motor 3 can quickly converge to the target speed while the focus servo control is turned on and thereafter the target track is moved.

FIG. 13 is a flowchart showing the processing of the fourth mode including the third mode, and the same steps as those in FIG. 12 have the same contents. That is, FIG. 13 inserts steps S30 to S33 after step S5 in FIG. 12 and executes steps S8 to S10 prior to step S6, and these points are different from FIG. In step S30, it is determined whether the difference between the current address obtained in step S5 and the target address is positive or negative and whether the movement is radial outward or radial inward, and then in step S31. The number of tracks Tj to be moved is calculated as Tj = track position Tp indicated by the current address−track position Td indicated by the target address, and it is determined whether or not Tj is a predetermined number K or more. That is, it is determined whether the number of tracks to be moved by the light spot in the radial direction is K or more. The constant K can be set to, for example, 100.

If the number of tracks Tj to be moved is equal to or larger than the predetermined value K, control is performed in step S32 so as to accelerate or decelerate the spindle motor 3 according to the moving direction. Specifically, the convergence to the CLV is executed in a short time by accelerating toward the inner periphery and decelerating toward the outer periphery. In order to execute the acceleration or deceleration, a value obtained by multiplying the number of tracks Tj to be moved by a constant M is output as an acceleration value or a deceleration value of the rotation of the spindle motor 3. That is, the rotation speed of the spindle motor 3 is accelerated or decelerated by a function of the moving direction of the light spot and the moving distance of the disk in the radial direction. On the other hand, if the number of tracks Tj to be moved is not equal to or greater than the predetermined value K in step S31, the same control value as the current rotational speed is held and output in step S33, or free-run is performed. In this case, a normal CLV corresponding to the address of the position of the light spot
Control is performed.

FIG. 14 is a schematic diagram showing the transition of the light spot and the timing of the control of the optical pickup and the control of the spindle motor in the third mode. After the end of step S32 or step S33, a focus jump is performed in step S8, and then focus servo control and tracking servo control are turned on in steps S9 and S10. Next, in step S34, the current address in the target layer is read, the direction to be moved and the number of tracks are recalculated, and movement to the target track is started. If acceleration or deceleration is required at this time, the acceleration or deceleration value has already been output in step S32 and applied to the spindle motor 3, so that the spindle motor 3 is accelerated or decelerated simultaneously or almost simultaneously with the focus jump in step S8. As a result, a predetermined speed can be obtained as soon as the vehicle reaches the target track. In this regard, the normal CL
In the V control, the address information is read from the track, and the CLV control is executed based on this information. Therefore, the acceleration or the deceleration is not executed during the focus jump. In FIG. 14, since the acceleration value or the deceleration value is applied during the focus jump and the spindle motor 3 is controlled, faster control is possible. After step S7, step S1
1, S12 is executed in the same manner as in FIG.

In the flowchart of FIG. 13, the operation of turning on the tracking servo control in step S10, the reading of the current address in the target layer in step S34, and the recalculation of the number of moving tracks using the same are omitted. The moving direction and the number of moving tracks may be determined using the information obtained in S5. This omission eliminates the need to perform calculations again, reduces the load on the processing program, and shortens the time until the start of movement. Since the track eccentricity differs between the original layer and the current layer (target layer), the information obtained in step S5 does not result in an accurate number of moving tracks, but causes an error.
By the processing of S12 and S12, the track is corrected by a precise track kick, and the target track can be accurately reached. Note that FIG. 13 shows steps S31 and S33.
May be deleted, and the process may go directly to step S32 from step S30. That is, acceleration or deceleration may be performed irrespective of whether or not the number of tracks Tj to be moved is equal to or greater than the predetermined value K, which is a third aspect of the present invention.

<Fifth Aspect> It is also possible to combine the first aspect with the third aspect or the fourth aspect. This combination is referred to as a fifth aspect of the present invention.

<Sixth Aspect> A configuration in which the above-described second aspect is combined with the third aspect or the fourth aspect may be adopted. Such a combination is referred to as a sixth aspect of the present invention.

<Seventh Aspect> The second method in the first aspect, that is, the method of performing a focus jump and then a track jump, and the third or fourth aspect may be combined. . Such a combination is referred to as a seventh aspect of the present invention.

[0065]

As described above, according to the present invention, D
When reproducing information from an optical recording medium having two or more recording layers, such as VD, with an optical pickup, when moving the light spot to a track position of a predetermined address on a layer different from the currently accessed layer, The traveling time is short, and an accurate and stable jump (search) to a target access point can be executed. In particular, in the first mode, which one of the focus jump and the track jump is executed first is appropriately selected according to the mode of movement of the light spot and other physical conditions. Shortening of travel time and stable search can be executed.
In the second embodiment, the focus jump is performed after the track jump. However, when compared with the method in which the focus jump is performed and then the track jump is performed, when the acceleration or deceleration of the spindle motor is necessary, the acceleration or deceleration is performed simultaneously with the track jump. And the time required to reach the predetermined speed can be shortened.

Further, in the third mode, the spindle motor is accelerated or decelerated simultaneously or almost simultaneously with the focus jump, and thereafter the track jump is performed. Therefore, the acceleration or deceleration of the spindle motor can be executed during the focus search in the focus jump. The moving time of the light spot to the target access point can be made shorter than that in which the acceleration or deceleration of the spindle motor is not performed during the focus search. Further, in the fourth mode, the acceleration / deceleration in the third mode is performed only when the number of tracks is equal to or more than a predetermined number. Therefore, unnecessary acceleration / deceleration is not performed, and the moving time is reduced. . In the fifth to seventh aspects, as described above, the two aspects or one aspect and a part of the other aspects are combined, so that the traveling time can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control procedure of an optical pickup according to a first embodiment, among operations of a microcomputer used in a system controller in FIG. 2;

FIG. 2 is a block diagram showing an embodiment of an optical disk reproducing apparatus according to the present invention.

FIG. 3 is a diagram showing a state in which a laser beam is focused on a disk in a bifocal optical pickup.

4 is a waveform diagram showing various signal waveforms obtained from output signals when a focus search is performed by an optical pickup corresponding to FIG. 3;

FIG. 5 is a waveform diagram showing a focus search in a two-layer disc.

6 is a circuit diagram showing an optical pickup and an arithmetic unit (part of the preamplifier in FIG. 2) responding to an output signal of the optical pickup in the embodiment of the optical disk reproducing apparatus of the present invention.

7 shows a sum signal SA and an EFM among output signals of the circuit of FIG. 6;
FIG. 3 is a block diagram illustrating an example of a circuit that detects a high-frequency component HF using a signal.

8 is a block diagram showing another example of a circuit for detecting a high-frequency component HF using an EFM signal in an output signal of the circuit of FIG. 6;

FIG. 9 is a flowchart showing a processing procedure for discriminating a disc type in the operation of the microcomputer used for the system controller in FIG. 2 and starting a reproducing operation.

FIG. 10 is a schematic diagram illustrating movement of a light spot in the first method and the movement of the light spot in the second method, respectively.

FIG. 11 shows a type 1 divided according to an addressing method.
FIG. 3 is a schematic diagram showing a type 2 disk.

FIG. 12 is a flowchart showing a control procedure of the optical pickup in the second mode in the operation of the microcomputer used in the system controller in FIG. 2;

13 is a flowchart showing a control procedure of an optical pickup in a fourth mode including a third mode in the operation of the microcomputer used in the system controller in FIG. 2;

FIG. 14 is a schematic diagram showing transition of light spots, control of an optical pickup, and timing of control of a spindle motor in a third mode.

[Explanation of symbols]

Reference Signs List 1 optical disk (optical recording medium) 2 optical pickup (optical head) 3 spindle motor 4 motor driver / tracking / focus control circuit (servo control means, focus jump means, track jump means, spindle motor control means together with DSV 6 and system controller 7) 5) Preamplifier 6 Digital servo (DSV) control circuit 7 System controller (current layer judgment means, track number detection means, control method judgment means, control means, movement direction detection means, acceleration / deceleration means, movement track number detection means) 10, 12, 14 Adder 16, 18, 20, 44 Subtractor 28 LPF (Low Pass Filter) 30 Switch 32, 34 Pulse Generator 36, 40 Gate Circuit 38, 42 Hold Circuit 46 Equalizer 50, 60 Comparator 52 54,56,62 D-FF 58 HPF (high pass filter) A, B, C, 4-split photosensor section E used in the D phase difference method, two sensor parts for use in F 3-beam method

Claims (16)

[Claims] 1. An optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and the optical pickup using the reflected light And servo control means for controlling the tracking servo control of the light beam and the focus servo control by controlling the light beam.
A current layer judging means for judging which of the layer and the second layer is located; a focus jump means for moving a light spot of the light beam from the current layer to another target layer; a focus of the light beam Current track number detecting means for detecting a track number at which the light spot is located, track jump means for moving the light spot of the light beam from the current track to another target track, and When it is necessary to move the light spot to another layer by the track jump means, first, the light spot is moved to the vicinity of the track of the current layer corresponding to the target track of the target layer. A first method of moving the light spot to a layer to be After the light spot is moved to the target layer, it is determined which of the second methods of moving the light spot to the target track of the target layer by the track jumping means is adopted. An optical disc reproducing apparatus comprising: a control method determining unit; and a light spot control unit that executes the first method or the second method determined by the control method determining unit. 2. An optical pickup of an optical disc reproducing apparatus for irradiating a disc-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and reading said information by an optical pickup for detecting reflected light. In the control method, the focused light spot of the light beam is the first light spot.
A current layer determining step of determining whether the light spot is located on a layer or a second layer; and when the light spot needs to be moved from the current layer to another layer, first, A first method of moving the light spot to a target layer by a focus jump means after moving the light spot near a track of a current layer corresponding to a track to be set; After moving the light spot to the layer to be
A control method judging step of judging which of the second methods of moving the light spot to a target track of a target layer by the track jump means is adopted. Pickup control method. 3. The method according to claim 1, further comprising the step of determining whether the direction of movement of the light spot is from the outer circumference to the inner circumference or from the inner circumference to the outer circumference of the optical disk. 3. The optical pickup control method according to claim 2, wherein the control method judging step adopts the first method, while the control method judging step adopts the second method when moving from the inner circumference to the outer circumference. 4. A step of judging whether the direction of movement of the light spot required is from the first layer to the second layer or from the second layer to the first layer of the optical disc. Further, when the control method is directed from the first layer to the second layer, the control method determination step employs the first method, while the control method determination step is performed from the second layer to the first layer. 3. The optical pickup control method according to claim 2, wherein said second method is adopted at a certain time. 5. The first layer and the second layer of the optical disk.
The method further comprises the step of determining whether the layers have the same address or have different addresses. When the layers have the same address, the control method determining step employs the first method, 3. The optical pickup control method according to claim 2, wherein the second method is adopted for types having different addresses. 6. An optical pickup of an optical disk reproducing apparatus for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and reading the information by an optical pickup for detecting reflected light. In the control method, the focused light spot of the light beam is the first light spot.
A current layer determining step of determining whether the light spot is located on a layer or a second layer; and when the light spot needs to be moved from the current layer to another layer, first, Moving the light spot near a track on a current layer corresponding to the track to be moved, and then moving the light spot to a target layer by a focus jump means. Control method. 7. After turning on the focus servo control and the tracking servo control, read the address of the current track and calculate the number of tracks to be moved; 7. The optical pickup control method according to claim 2, further comprising a precision track kick step of moving. 8. An optical pickup for irradiating a disc-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and rotating and driving the optical recording medium. A spindle motor; a spindle motor control means for controlling the number of revolutions of the spindle motor to obtain a CLV during normal reproduction; a tracking servo control of the light beam by controlling the optical pickup using the reflected light; and a focus servo control Servo control means for performing the following;
A current layer judging means for judging which of the layer and the second layer is located; a focus jump means for moving a light spot of the light beam from the current layer to another target layer; a focus of the light beam Current track number detecting means for detecting a track number at which the selected light spot is located, track jumping means for moving the light spot of the light beam from the current track to another target track, and moving by the track jumping means. A light spot moving direction detecting means for detecting a power direction; and a spindle motor control means for performing a focus jump when a moving direction of the light spot detected by the light spot moving direction detecting means is from the outer circumference to the inner circumference. Sometimes the speed of the spindle motor is accelerated, while Wherein the acceleration and deceleration means for spindle motor control means controls so as to reduce the rotation speed of the spindle motor at the time of focus jump has optical disc reproducing apparatus when it is. 9. An optical pickup for irradiating a disk-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and rotating and driving the optical recording medium A spindle motor; spindle motor control means for controlling the number of revolutions of the spindle motor to obtain CLV during normal reproduction; tracking servo control of the light beam by controlling the optical pickup using the reflected light; and focus servo control Servo control means for performing the following;
A current layer judging means for judging which of the layer and the second layer is located; a focus jump means for moving a light spot of the light beam from the current layer to another target layer; a focus of the light beam Current track number detecting means for detecting a track number at which the light spot is located, track jumping means for moving the light spot of the light beam from the current track to another target track, and moving by the track jumping means. A light spot moving direction detecting means for detecting a power direction, a moving track number detecting means for detecting the number of tracks to be moved by the track jumping means, and a predetermined number of tracks to be moved detected by the moving track number detecting means. The light spots detected by the light spot moving direction detecting means. When the moving direction of the cut is from the outer circumference to the inner circumference, the spindle motor control means accelerates the rotation speed of the spindle motor at the time of a focus jump, while the movement detected by the moving track number detection means is increased. Acceleration / deceleration means for controlling the spindle motor control means to reduce the number of revolutions of the spindle motor during a focus jump when the number of tracks to be expended is equal to or more than a predetermined number and is directed from the inner circumference to the outer circumference. Optical disc playback device. 10. An optical pickup for irradiating a disc-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and rotating and driving the optical recording medium. A spindle motor; spindle motor control means for controlling the number of revolutions of the spindle motor to obtain CLV during normal reproduction; tracking servo control of the light beam by controlling the optical pickup using the reflected light; and focus servo control Servo control means for performing the following;
A current layer judging means for judging which of the layer and the second layer is located; a focus jump means for moving a light spot of the light beam from the current layer to another target layer; a focus of the light beam Current track number detecting means for detecting a track number at which the light spot is located, track jump means for moving the light spot of the light beam from the current track to another target track, and When it is necessary to move the light spot to another layer by the track jump means, first, the light spot is moved to the vicinity of the track of the current layer corresponding to the target track of the target layer. A first method of moving the light spot to a layer to be After moving the light spot to the target layer, it is determined which of the second methods of moving the light spot to the target track of the target layer by the track jumping means is adopted. Control method determination means; light spot control means for executing the first method or the second method determined by the control method determination means; and light spot movement for detecting a direction to be moved by the track jump means. Direction detecting means, when the moving direction of the light spot detected by the light spot moving direction detecting means is from the outer circumference to the inner circumference, the spindle motor control means increases the rotation speed of the spindle motor during a focus jump. When the vehicle is moving from the inner circumference to the outer circumference, the spindle motor control means And deceleration means for controlling so as to reduce the rotation speed of the spindle motor at the time of jump, with the optical disc reproducing apparatus. 11. An optical pickup for irradiating a disc-shaped optical recording medium having information recorded on a first layer and a second layer with a light beam and detecting reflected light, and rotating and driving the optical recording medium. A spindle motor; a spindle motor control means for controlling the number of revolutions of the spindle motor to obtain a CLV during normal reproduction; a tracking servo control of the light beam by controlling the optical pickup using the reflected light; and a focus servo control Servo control means for performing the following;
A current layer judging means for judging which of the layer and the second layer is located; a focus jump means for moving a light spot of the light beam from the current layer to another target layer; a focus of the light beam Current track number detecting means for detecting a track number at which the light spot is located, track jump means for moving the light spot of the light beam from the current track to another target track, and When it is necessary to move the light spot to another layer by the track jump means, first, the light spot is moved to the vicinity of the track of the current layer corresponding to the target track of the target layer. A first method of moving the light spot to a layer to be After the light spot is moved to the target layer, it is determined which of the second methods of moving the light spot to the target track of the target layer by the track jumping means is adopted. Control method determination means; light spot control means for executing the first method or the second method determined by the control method determination means; and light spot movement for detecting a direction to be moved by the track jump means. Direction detecting means, moving track number detecting means for detecting the number of tracks to be moved by the track jumping means, and the number of tracks to be moved detected by the moving track number detecting means is a predetermined number or more, and the light When the moving direction of the light spot detected by the spot moving direction detecting means is from the outer circumference to the inner circumference. Means that the spindle motor control means accelerates the rotation speed of the spindle motor at the time of a focus jump, while the number of tracks to be moved detected by the moving track number detection means is a predetermined number or more, and from the inner circumference to the outer circumference. An optical disc reproducing device comprising: an accelerating / decelerating means for controlling the spindle motor control means to decelerate the rotation speed of the spindle motor at the time of a focus jump when the heading is in progress. 12. During normal reproduction, the first motor is rotated by a spindle motor whose rotation speed is controlled to be CLV.
An optical pickup control method for an optical disk reproducing apparatus for irradiating a disk-shaped optical recording medium having information recorded on a layer and a second layer with a light beam and reading out the information by an optical pickup for detecting reflected light; The focused light spot of the first
A current layer determining step of determining which of the layer and the second layer is located; a step of detecting a direction in which the light spot is to be moved; and a step of moving the light spot from the current layer to another layer. At one time, if the direction in which the light spot should move is from the outer circumference to the inner circumference, the rotation speed of the spindle motor is accelerated during the focus jump, while if it is from the inner circumference to the outer circumference, the focus jump is performed. Sometimes controlling the rotation speed of the spindle motor to be reduced, and when it is necessary to move the light spot from the current layer to another layer, the track jump means first responds to the target track of the target layer. Moving the light spot to the vicinity of the track of the current layer to be moved. Moving the light spot to a layer of the optical pickup. 13. During normal playback, the first motor is rotated by a spindle motor whose rotation speed is controlled to be CLV.
An optical pickup control method for an optical disk reproducing apparatus for irradiating a disk-shaped optical recording medium having information recorded on a layer and a second layer with a light beam and reading out the information by an optical pickup for detecting reflected light; The focused light spot of the first
A current layer determination step of determining which of the layer and the second layer is located; a step of detecting a direction in which the light spot is to be moved; and a step of detecting the number of tracks in which the light spot is to be moved. When the light spot needs to be moved from the current layer to another layer, the detected number of tracks to be moved is equal to or more than a predetermined number, and the direction in which the light spot is to be moved is from the outer circumference to the inner circumference. At one time, the rotation speed of the spindle motor is accelerated at the time of the focus jump. Controlling to reduce the number of rotations of the motor; and when it is necessary to move the light spot from the current layer to another layer, First moving the light spot to the vicinity of the track of the current layer corresponding to the target track of the target layer by the jump means; and then moving the light spot to the target layer by the focus jump means. An optical pickup control method, comprising: 14. During normal playback, the first motor is rotated by a spindle motor whose rotation speed is controlled to be CLV.
An optical pickup control method for an optical disk reproducing apparatus for irradiating a disk-shaped optical recording medium having information recorded on a layer and a second layer with a light beam and reading out the information by an optical pickup for detecting reflected light; The focused light spot of the first
A current layer determining step of determining which of the layer and the second layer is located; a step of detecting a direction in which the light spot is to be moved; At one time, if the direction in which the light spot should move is from the outer circumference to the inner circumference, the rotation speed of the spindle motor is accelerated during the focus jump, while if it is from the inner circumference to the outer circumference, the focus jump is performed. Sometimes controlling to reduce the rotation speed of the spindle motor; and when it is necessary to move the light spot from the current layer to another layer, first move the light spot to a target layer by a focus jump means. Moving the light spot to a target track of a target layer by a track jump means thereafter And an optical pickup control method. 15. During normal playback, the first motor is rotated by a spindle motor whose rotation speed is controlled to be CLV.
An optical pickup control method for an optical disk reproducing apparatus for irradiating a disk-shaped optical recording medium having information recorded on a layer and a second layer with a light beam and reading said information by an optical pickup for detecting reflected light; Current layer determining step of determining whether the focused light spot is located on the first layer or the second layer; detecting a direction in which the light spot should be moved; moving the light spot Detecting the number of tracks to be moved; and when the light spot needs to be moved from the current layer to another layer, the detected number of tracks to be moved is equal to or more than a predetermined number, and the light spot should be moved. When the direction is from the outer circumference to the inner circumference, the rotation speed of the spindle motor is accelerated during the focus jump, while the detected shift is When the number of tracks to be recorded is equal to or more than a predetermined number and is directed from the inner circumference to the outer circumference, controlling the rotation speed of the spindle motor during a focus jump to reduce the rotation speed of the spindle motor. When the light spot needs to be moved to the layer, first, the light spot is moved to a target layer by a focus jump means, and then, the light spot is moved to a target track of the target layer by a track jump means. An optical pickup control method, comprising: 16. The step of controlling the rotational speed of the spindle motor to accelerate or decelerate, wherein the rotational speed of the spindle motor is determined by a function of a moving direction and a number of tracks to be moved or a radial distance of a disk to be moved. 16. The optical pickup control method according to claim 12, wherein the optical pickup is accelerated or decelerated.