JPH10134375A - Optical disk reproducing device and method for optimizing servo control of optical disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a waiting time at the time of start up by performing optimizing processing of servo control of a layer to be reproduced on a medium having plural recording layers first, storing this reproducing data in a memory means and afterward performing the optimizing processing on another layer during reproducing execution of reading this reproducing data. SOLUTION: In addition to normal system control, the kind of a disk is discriminated, and also an amplitude of a signal from a preamplifier 9 is measured, and a tap gain of a transversal filter incorporated in the preamplifier 9 is adjusted to be optimized and set by a system controller 11 with operation of a CPU. When once the optimizing control is performed, its data is stored in an EEPROM 7. When reproduction is commenced, the necessary data is read out of the EEPROM 7, and is transferred to the preamplifier 9 and a digital servo control circuit (DSV) 10. Subsequently, a quantity of reflected light is detected, and based on this detection, the kind of the disk is discriminated. Then, an optimum table value is set to correspond to the measured value.

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 recording / reproducing a signal on / from a disk-shaped recording medium, and in particular, to appropriately controlling a servo control mechanism of a recording / reproducing head. In addition to optimizing the reproduction signal from the optical pickup, specifically, data is written to a disk such as a DVD (digital video disk or digital versatile disk) capable of recording data on a plurality of recording layers. The present invention relates to optimization control of an information recording / reproducing apparatus which records and reproduces data in a predetermined block time unit.

[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 used in practice. 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 disk-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.

[0003] Among these optical recording media, DVD has a high signal recording density. Of the EFM + reproduction signals obtained by reading out the DVD recording signal with the optical head, the reproduction amplitude of the 3T wavelength signal is about 25% of the reproduction amplitude of the 14T wavelength signal among the 3T to 14T wavelength signals. become.
Therefore, the frequency characteristics of the high-frequency signal are raised by a waveform equivalent equalizer to improve the signal jitter.

[0004]

However, the pit shape of the disk, the optical frequency characteristics of the optical pickup, and the IV
The frequency characteristics of the conversion amplifier, the operational amplifier, and the like change from the time of the initial due to the influence of temperature change and aging. Therefore, among the plurality of manufactured optical disk reproducing devices, there may be a case where the state of each part varies.
In response to physical changes in the use environment of optical disk recording / reproducing devices and optical disk reproducing devices, and non-uniformity of disks,
In order to readjust the offset, balance, gain, etc. of the tracking error signal and the focus error signal, in the conventional method, the optical disk recording / reproducing apparatus or the optical disk reproducing apparatus must be stopped once and released from the recording or reproducing state. Therefore, it is not possible to cope with a case where the use environment of the optical disk recording / reproducing apparatus or the optical disk reproducing apparatus suddenly changes during recording or reproduction. For example, when the outside temperature is −30 ° C., and a disc placed in such an atmosphere is brought indoors at + 25 ° C. and loaded into an optical disc recording / reproducing apparatus or an optical disc reproducing apparatus, an automatic recording or reproduction is started at the beginning. The offset, balance, and gain of the tracking error signal and the focus error signal set appropriately and appropriately change over time, and servo control becomes impossible at a certain time, that is, at a time when the temperature of the disk has risen to some extent. Sometimes.

[0005] Prior to the present invention, the present inventor has considered the above-mentioned conventional problems and has considered that even if there is a change in the physical state of the optical disk recording / reproducing device or the optical disk reproducing device itself or the nonuniformity of the optical recording medium, The offset, balance, and gain of the tracking error signal and the focus error signal can be readjusted quickly and accurately without stopping the optical disk recording / reproducing device or the optical disk reproducing device itself, that is, without interrupting recording and reproduction. An optical disk recording / reproducing device has been developed and a patent application has been filed (Japanese Patent Application No. Hei 7-31514). In one aspect of the invention disclosed in the prior application, in order to solve the above-described conventional problem, the physical state of the optical disk recording / reproducing apparatus itself or the optical recording medium is detected, and the detected physical state is determined as a reference value or a reference value. , By comparing with the value before the physical state in time, detecting whether the optical head is recording or reading on the optical disk or in a standby state, and detecting the offset and balance of the tracking error signal and the focus error signal. When it is necessary to readjust at least one of the gains, the optical head is readjusted to optimize the control by the servo control means when the optical head is in a standby state with respect to the optical disk.

In another aspect of the invention disclosed in the prior application, in order to solve the above-mentioned conventional problem, the elapsed time after the power of the optical disk recording / reproducing apparatus itself is turned on is measured, and the measured time is measured. The elapsed time is compared with a reference value to detect whether the optical head is recording or reading data to or from the optical disk or is in a standby state. At least one of offset, balance, and gain of the tracking error signal and the focus error signal is detected. When readjustment is necessary, readjustment is performed so as to optimize the control by the servo control means when the optical head is in a standby state.

In another aspect of the invention disclosed in the prior application, in order to solve the above-mentioned conventional problem, an error signal generated in error correction means of an optical disk reproducing device is counted, and the number of counted error signals is counted. Is compared with a reference value to detect whether the optical head is reading data from the optical disk or in a standby state. If the number of error signals counted exceeds the reference value, the offset of the tracking error signal and the focus error signal is detected. It is determined that at least one of the balance, the gain, and the gain needs to be readjusted, and when the optical head is in the standby state, the readjustment is performed so as to optimize the control by the servo control means.
The “optical disk recording / reproducing device” means a disk device having one or both of an optical disk recording function and an optical disk reproducing function.

According to the invention disclosed in the prior application, when the number of recording layers of the disk is one, the servo control optimization processing is performed as needed.
When a plurality of layers or more layers are provided, it is necessary to perform focus control for each layer, and if the recording density of data is different for each recording layer, the track pitch and reflectivity are different, and the tracking control is different from the tracking control. Optimization processing in focus control also needs to be performed for each layer. As described above, it is necessary to select a pickup and a signal processing circuit portion suitable for each layer and perform an optimization process due to a difference in recording mode of each layer, and the adjustment time required for that is 1 second per layer. Then, 2 seconds for 2 layers and n seconds for n layers. For example, if this adjustment is performed for all layers after the apparatus is started or after the disc is exchanged or loaded, the playback apparatus must wait for the time to start playback. It will not be. When the optimization processing is required due to factors such as temperature change, for example, if the optimization processing is performed on both the first layer and the second layer during the reproduction of the first layer, the reproduction of the first layer is interrupted. May occur, which is inconvenient.

Therefore, according to the present invention, even when a disk is provided with a plurality of recording layers, a desired optimizing process is performed by shortening the waiting time at the time of starting (including when the disk is replaced or loaded). It is a first object of the present invention to provide an optical disk reproducing apparatus and a method for optimizing servo control of the optical disk reproducing apparatus. Further, even when a disc is provided with a plurality of recording layers, if optimization processing is required due to factors such as a temperature change during normal reproduction, it is possible to prevent interruption during reproduction. It is a second object of the present invention to provide an optical disk reproducing apparatus capable of performing the above optimization processing and a method for optimizing servo control of the optical disk reproducing apparatus.

[0010]

In order to achieve the first object, in the present invention, when the optimization process is performed at the time of startup, the optimization process is not performed continuously for all layers but is necessary for the time being. An optimization process is performed on a layer in which information is recorded, a certain amount of information from the layer is read out and stored in a memory, and this information is read out and reproduced. While the head is on standby, optimization processing is performed on other layers.
As an optimization process, in one aspect of the present invention, an envelope detector for a reproduced RF signal and an RF3T signal is provided to detect a frequency characteristic, and a tap gain of a transversal filter that processes the RF signal is determined based on a ratio of the detected signals. It is configured so as to optimize the frequency characteristics as the quality of the reproduced signal. In another aspect of the present invention, after optimizing the focus servo control, the jitter of the reproduced RF signal is measured, and the tap gain of the transversal filter for processing the RF signal is optimized so that the value of the jitter is optimized. It is configured. Further, in order to achieve the second object, in the present invention, when performing the optimization processing at the time of normal reproduction due to factors such as temperature change, the optimization processing is not performed continuously for all layers, but is necessary for the time being. A certain amount of information from the layer in which the information is recorded is read out and stored in the memory, and this information is read out and reproduced. The optimization process is performed, and then the optimization process is performed on other layers while the memory has more than a predetermined amount of information, that is, while the optical head is on standby.

That is, according to the present invention, there is provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium. A time axis changing means for reading data from the memory means at a speed lower than a speed at which read data from the optical head is written to the memory means when reading from the optical disc;
Servo control means for performing tracking control of the optical head and / or focus control of the optical head, and means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk In the optimizing means, which can optimize the control in the servo control means for each recording layer of the plurality of recording layers,
A recording layer judging unit for judging from which of the plurality of recording layers information reproduction is required;
When information reproduction is requested for a layer, an optimization process is performed on the first layer by the optimization unit, a predetermined amount of information is read from the first layer, and stored in the memory unit. When information equal to or more than a first predetermined amount is stored in the memory means, the optical head is set to the standby state, information is read from the memory means to perform a reproducing operation, and the optimizing means for the second layer is performed. , And when the amount of information stored in the memory unit is smaller than a second predetermined amount,
A predetermined amount of information is read from the first layer and stored in the memory means. When reproduction of information is requested for the second layer, optimization processing by the optimization means for the second layer is performed. A predetermined amount of information is read from the second layer and stored in the memory unit. When the memory unit stores information of a first predetermined amount or more, the optical head is set in the standby state. Controlling the readout of the information from the memory means to perform the reproducing operation, and performing the optimization process by the optimization means for the recording layers other than the second layer, so that the amount of information stored in the memory means is equal to the second. When the amount becomes smaller than the predetermined amount, at least after the optical disk reproducing apparatus is started or the optical disk is read so that a predetermined amount of information is read from the second layer and stored in the memory means. Control means for controlling after the recording medium is loaded, and wherein the optimizing means detects the quality of a reproduction signal which is an output signal from the optical head, and the signal quality detecting means detects Means for optimizing the quality of the output signal of the optical head according to the obtained signal quality.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether or not information reproduction from the shift recording layer is required; and an optimization processing by the optimization unit for the first layer when information reproduction is required for the first layer. And reading out a predetermined amount of information from the first layer and storing it in the memory means. When the memory means stores more than a first predetermined amount of information, the optical head is placed in the standby state. As a state, information is read from the memory means to perform a reproducing operation, and the second layer is controlled so as to perform an optimizing process by the optimizing means, and the amount of information stored in the memory means becomes smaller than a second predetermined amount. When the number decreases, a predetermined amount of information is read from the first layer and stored in the memory means. When reproduction of information is requested for the second layer, the information is read for the second layer. When an optimization process is performed by the optimization unit, a predetermined amount of information is read from the second layer and stored in the memory unit, and the memory unit stores information of a first predetermined amount or more. Is
While the optical head is in the standby state, information is read from the memory unit to perform a reproducing operation, and control is performed such that the optimizing unit performs an optimizing process on a recording layer other than the second layer. When the amount of stored information is smaller than the second predetermined amount, at least after the optical disk reproducing apparatus is started or the optical recording is performed, a predetermined amount of information is read from the second layer and stored in the memory means. Frequency characteristic changing means having control means for controlling after loading of a medium, wherein the optimizing means can change frequency characteristics of a reproduction signal which is an output signal from the optical head; and Filter means for extracting the highest frequency band of the signal, first envelope generating means for obtaining the amplitude of the reproduction signal, and amplitude of the output signal of the filter means A second envelope generation means for obtaining,
A comparing means for comparing the amplitudes obtained by the first and second envelope generating means, and a control signal for changing a frequency characteristic of the frequency characteristic changing means according to a result of the comparison by the comparing means. An optical disk reproducing device comprising a control unit is provided.

Further, according to the present invention, there is provided an optical disc reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disc-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether or not information reproduction from the shift recording layer is required; and an optimization processing by the optimization unit for the first layer when information reproduction is required for the first layer. And reading out a predetermined amount of information from the first layer and storing it in the memory means. When the memory means stores more than a first predetermined amount of information, the optical head is placed in the standby state. As a state, information is read from the memory means to perform a reproducing operation, and the second layer is controlled so as to perform an optimizing process by the optimizing means, and the amount of information stored in the memory means becomes smaller than a second predetermined amount. When the number decreases, a predetermined amount of information is read from the first layer and stored in the memory means. When reproduction of information is requested for the second layer, the information is read for the second layer. When an optimization process is performed by the optimization unit, a predetermined amount of information is read from the second layer and stored in the memory unit, and the memory unit stores information of a first predetermined amount or more. Is
While the optical head is in the standby state, information is read from the memory unit to perform a reproducing operation, and control is performed such that the optimizing unit performs an optimizing process on a recording layer other than the second layer. When the amount of stored information is smaller than the second predetermined amount, at least after the optical disk reproducing apparatus is started or the optical recording is performed, a predetermined amount of information is read from the second layer and stored in the memory means. Frequency characteristic changing means having control means for controlling after loading of a medium, wherein the optimizing means can change frequency characteristics of a reproduction signal which is an output signal from the optical head; and Clock extracting means for extracting a clock from the clock signal; measuring means for measuring the jitter of the clock and the reproduced signal extracted by the clock extracting means; A comparison unit that compares the jitter measured by the measurement unit with a predetermined value, and a control unit that generates a control signal that changes a frequency characteristic of the frequency characteristic change unit according to a result compared by the comparison unit, There is provided an optical disk reproducing apparatus characterized by having the above.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether or not information reproduction from the shift recording layer is required; and an optimization processing by the optimization unit for the first layer when information reproduction is required for the first layer. And reading out a predetermined amount of information from the first layer and storing it in the memory means. When the memory means stores more than a first predetermined amount of information, the optical head is placed in the standby state. As a state, information is read from the memory means to perform a reproducing operation, and the second layer is controlled so as to perform an optimizing process by the optimizing means, and the amount of information stored in the memory means becomes smaller than a second predetermined amount. When the number decreases, a predetermined amount of information is read from the first layer and stored in the memory means. When reproduction of information is requested for the second layer, the information is read for the second layer. When an optimization process is performed by the optimization unit, a predetermined amount of information is read from the second layer and stored in the memory unit, and the memory unit stores information of a first predetermined amount or more. Is
While the optical head is in the standby state, information is read from the memory unit to perform a reproducing operation, and control is performed such that the optimizing unit performs an optimizing process on a recording layer other than the second layer. When the amount of stored information is smaller than the second predetermined amount, at least after the optical disk reproducing apparatus is started or the optical recording is performed, a predetermined amount of information is read from the second layer and stored in the memory means. Frequency characteristic changing means having control means for controlling after loading of a medium, wherein the optimizing means can change frequency characteristics of a reproduction signal which is an output signal from the optical head; and Filter means for extracting the highest frequency band of the signal, first envelope generating means for obtaining the amplitude of the reproduction signal, and amplitude of the output signal of the filter means A second envelope generation means for obtaining,
First storage means for storing the amplitudes obtained by the first and second envelope generation means, calculation means for comparing the amplitudes stored in the first storage means, and a calculation result by the calculation means And a control means for generating a control signal for changing a frequency characteristic of the frequency characteristic changing means in accordance with the operation result stored in the second storage means. An optical disk reproducing apparatus characterized by the above features is provided.

Further, according to the present invention, there is provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether or not information reproduction from the shift recording layer is required; and an optimization processing by the optimization unit for the first layer when information reproduction is required for the first layer. And reading out a predetermined amount of information from the first layer and storing it in the memory means. When the memory means stores more than a first predetermined amount of information, the optical head is placed in the standby state. As a state, information is read from the memory means to perform a reproducing operation, and the second layer is controlled so as to perform an optimizing process by the optimizing means, and the amount of information stored in the memory means becomes smaller than a second predetermined amount. When the number decreases, a predetermined amount of information is read from the first layer and stored in the memory means. When reproduction of information is requested for the second layer, the information is read for the second layer. When an optimization process is performed by the optimization unit, a predetermined amount of information is read from the second layer and stored in the memory unit, and the memory unit stores information of a first predetermined amount or more. Is
While the optical head is in the standby state, information is read from the memory unit to perform a reproducing operation, and control is performed such that the optimizing unit performs an optimizing process on a recording layer other than the second layer. When the amount of stored information is smaller than the second predetermined amount, at least after the optical disk reproducing apparatus is started or the optical recording is performed, a predetermined amount of information is read from the second layer and stored in the memory means. Frequency characteristic changing means having control means for controlling after loading of a medium, wherein the optimizing means can change frequency characteristics of a reproduction signal which is an output signal from the optical head; and Clock extracting means for extracting a clock from the clock signal; measuring means for measuring the jitter of the clock and the reproduced signal extracted by the clock extracting means; First storage means for storing the jitter measured by the measurement means, comparison means for comparing the jitter stored in the first storage means with a predetermined value, and the frequency based on the result of comparison by the comparison means. Control means for generating a control signal for changing the frequency characteristic of the characteristic change means,
There is provided an optical disk reproducing apparatus characterized by having the above.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether information reproduction from the misaligned recording layer is required, and detecting which of the recording layers of the optical disk the optical head is reading or is in the standby state When the reproduction of information for the first layer is requested, the optimization processing is performed on the first layer by the optimization means, and a predetermined amount of information is read from the first layer. To store the data in the memory means, read the information from the memory means and perform a reproducing operation, and cause the optimizing means to perform the optimizing process on the second layer when the first layer is in the standby state. When the reproduction of information is requested for the second layer, an optimization process is performed on the second layer by the optimizing means, and a predetermined amount of information is reproduced from the second layer. When the readout is performed and stored in the memory unit, the information is read out from the memory unit and the reproduction operation is performed, and when the second layer is in the standby state, the optimization processing by the optimization unit is performed on the first layer. Control means for controlling at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, and the optimizing means controls the quality of a reproduced signal which is an output signal from the optical head. An optical disc reproducing apparatus is provided, comprising: signal quality detecting means for detecting; and means for optimizing the quality of an output signal of the optical head according to the signal quality detected by the signal quality detecting means. You.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether information reproduction from the misaligned recording layer is required, and detecting which of the recording layers of the optical disk the optical head is reading or is in the standby state When the reproduction of information for the first layer is requested, the optimization processing is performed on the first layer by the optimization means, and a predetermined amount of information is read from the first layer. To store the data in the memory means, read the information from the memory means and perform a reproducing operation, and cause the optimizing means to perform the optimizing process on the second layer when the first layer is in the standby state. When the reproduction of information is requested for the second layer, an optimization process is performed on the second layer by the optimizing means, and a predetermined amount of information is reproduced from the second layer. When the readout is performed and stored in the memory unit, the information is read out from the memory unit and the reproduction operation is performed, and when the second layer is in the standby state, the optimization processing by the optimization unit is performed on the first layer. Control means for controlling at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, and wherein the optimizing means controls a frequency characteristic of a reproduced signal as an output signal from the optical head. , A filter means for extracting the highest frequency band of the reproduction signal, a first envelope generation means for obtaining an amplitude of the reproduction signal, and an amplitude of an output signal of the filter means. Second envelope generating means to be obtained, and comparing means for comparing the amplitudes obtained by the first and second envelope generating means; An optical disc reproducing apparatus comprising: a control unit that generates a control signal that changes a frequency characteristic of the frequency characteristic changing unit in accordance with a result of the comparison by the comparing unit.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether information reproduction from the misaligned recording layer is required, and detecting which of the recording layers of the optical disk the optical head is reading or is in the standby state When the reproduction of information for the first layer is requested, the optimization processing is performed on the first layer by the optimization means, and a predetermined amount of information is read from the first layer. To store the data in the memory means, read the information from the memory means and perform a reproducing operation, and cause the optimizing means to perform the optimizing process on the second layer when the first layer is in the standby state. When the reproduction of information is requested for the second layer, an optimization process is performed on the second layer by the optimizing means, and a predetermined amount of information is reproduced from the second layer. When the readout is performed and stored in the memory unit, the information is read out from the memory unit and the reproduction operation is performed, and when the second layer is in the standby state, the optimization processing by the optimization unit is performed on the first layer. Control means for controlling at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, and wherein the optimizing means controls a frequency characteristic of a reproduced signal as an output signal from the optical head. Frequency characteristic changing means capable of changing the clock, clock extracting means for extracting a clock from the reproduced signal, measuring means for measuring the clock extracted by the clock extracting means and jitter of the reproduced signal, and the measuring means Comparing means for comparing the jitter measured in the above with a predetermined value, and said frequency characteristic according to the result compared by said comparing means And a control unit for generating a control signal for changing a frequency characteristic of the changing unit.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether information reproduction from the misaligned recording layer is required, and detecting which of the recording layers of the optical disk the optical head is reading or is in the standby state When the reproduction of information for the first layer is requested, the optimization processing is performed on the first layer by the optimization means, and a predetermined amount of information is read from the first layer. To store the data in the memory means, read the information from the memory means and perform a reproducing operation, and cause the optimizing means to perform the optimizing process on the second layer when the first layer is in the standby state. When the reproduction of information is requested for the second layer, an optimization process is performed on the second layer by the optimizing means, and a predetermined amount of information is reproduced from the second layer. When the readout is performed and stored in the memory unit, the information is read out from the memory unit and the reproduction operation is performed, and when the second layer is in the standby state, the optimization processing by the optimization unit is performed on the first layer. Control means for controlling at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, and wherein the optimizing means controls a frequency characteristic of a reproduced signal which is an output signal from the optical head. Frequency change means capable of changing the amplitude, a filter means for extracting the highest frequency band of the reproduced signal, a first envelope generating means for obtaining an amplitude of the reproduced signal, and an amplitude of an output signal of the filter means. A second envelope generating means for obtaining the first and second envelopes, and a first envelope for storing the amplitudes obtained by the first and second envelope generating means.
Storage means, an operation means for comparing the amplitudes stored in the first storage means, a non-volatile second storage means for storing a result of the operation by the operation means, and a storage means in the second storage means A control unit for generating a control signal for changing a frequency characteristic of the frequency characteristic changing unit according to the calculation result.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. A servo control means for performing control and / or focus control of the optical head; and a means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the servo control means Optimizing means capable of optimizing control in the means for each of the plurality of recording layers; and A recording layer judging unit for judging whether information reproduction from the misaligned recording layer is required, and detecting which of the recording layers of the optical disk the optical head is reading or is in the standby state When the reproduction of information for the first layer is requested, the optimization processing is performed on the first layer by the optimization means, and a predetermined amount of information is read from the first layer. To store the data in the memory means, read the information from the memory means and perform a reproducing operation, and cause the optimizing means to perform the optimizing process on the second layer when the first layer is in the standby state. When the reproduction of information is requested for the second layer, an optimization process is performed on the second layer by the optimizing means, and a predetermined amount of information is reproduced from the second layer. When the readout is performed and stored in the memory unit, the information is read out from the memory unit and the reproduction operation is performed, and when the second layer is in the standby state, the optimization processing by the optimization unit is performed on the first layer. Control means for controlling at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, and wherein the optimizing means controls a frequency characteristic of a reproduced signal as an output signal from the optical head. Frequency characteristic changing means capable of changing the clock, clock extracting means for extracting a clock from the reproduced signal, measuring means for measuring the clock extracted by the clock extracting means and jitter of the reproduced signal, and the measuring means First storage means for storing the jitter measured in the step (c), and comparing the jitter stored in the first storage means with a predetermined value. An optical disc reproducing apparatus is provided, comprising: a control unit for generating a control signal for changing a frequency characteristic of the frequency characteristic changing unit in accordance with a result of comparison by the comparing unit.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. Servo control of an optical disc reproducing apparatus, comprising: servo control means for performing control and / or focus control of the optical head; and means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disc. Optimization method, at least after starting the optical disc reproducing apparatus or after loading the optical recording medium Judging from which of the plurality of recording layers information reproduction is required, and optimizing servo control for the first layer when information reproduction is required for the first layer. Performing a process, reading a predetermined amount of information from the first layer and storing the information in the memory means, and when the memory means stores at least a first predetermined amount of information, Setting the optical head in the standby state, reading out information from the memory unit and performing a reproducing operation, and executing the optimization process on the second layer, wherein the amount of information stored in the memory unit is a second predetermined amount. Reading the information from the first layer and storing the information in the memory means,
When information reproduction is requested for a layer, executing the optimization process for the second layer; reading a predetermined amount of information from the second layer and storing the information in the memory means; When information of a first predetermined amount or more is stored in the memory means, the optical head is set in the standby state, information is read out from the memory means to perform a reproducing operation, and a recording layer other than the second layer is read. Executing the optimizing process on the memory, and when the amount of information stored in the memory means is smaller than a second predetermined amount, reading out a predetermined amount of information from the second layer and storing the information in the memory means Performing the optimization process; and performing focus servo control on the optical head; and performing tracking servo control on the optical head. Controlling, the step of optimizing the quality of the reproduced signal, the step of obtaining the amplitude of the reproduced signal, the filtering step of extracting the highest frequency band of the reproduced signal, and the step of extracting the highest frequency band of the reproduced signal. Obtaining the amplitude of the output signal of the highest frequency band, storing the obtained amplitudes, calculating the stored amplitudes to compare them, and calculating the results obtained in the calculating step Generating a control signal for changing a frequency characteristic of the frequency characteristic changing means in accordance with the above method.

According to the present invention, there is also provided an optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein reproduced data is temporarily stored. Memory means for temporarily storing data, time axis changing means for reading data from the memory means at a speed lower than a speed for writing read data from the optical head to the memory means when reading from the optical disk, and tracking of the optical head. Servo control of an optical disc reproducing apparatus comprising: servo control means for performing control and / or focus control of the optical head; and means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disc. Optimization method, at least after starting the optical disc reproducing apparatus or after loading the optical recording medium Judging from which of the plurality of recording layers information reproduction is required, and optimizing servo control for the first layer when information reproduction is required for the first layer. Performing a process, reading a predetermined amount of information from the first layer and storing the information in the memory means, and when the memory means stores at least a first predetermined amount of information, Setting the optical head in the standby state, reading out information from the memory unit and performing a reproducing operation, and executing the optimization process on the second layer, wherein the amount of information stored in the memory unit is a second predetermined amount. Reading the information from the first layer and storing the information in the memory means,
When information reproduction is requested for a layer, executing the optimization process for the second layer; reading a predetermined amount of information from the second layer and storing the information in the memory means; When information of a first predetermined amount or more is stored in the memory means, the optical head is set in the standby state, information is read out from the memory means to perform a reproducing operation, and a recording layer other than the second layer is read. Executing the optimizing process on the memory, and when the amount of information stored in the memory means is smaller than a second predetermined amount, reading out a predetermined amount of information from the second layer and storing the information in the memory means Performing the optimization process; and performing focus servo control on the optical head; and performing tracking servo control on the optical head. Controlling the quality of the reproduced signal, measuring the jitter of the reproduced signal, storing the measured jitter, and changing the frequency characteristic of the frequency characteristic changing means. Adjusting the jitter of the reproduced signal again; comparing the first measured jitter with the subsequently measured jitter; and adjusting the frequency of the frequency characteristic changing means according to the result of the comparison. And a control step of generating a control signal for changing a characteristic of the optical disc reproducing apparatus.

[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 a DVD recording / reproducing apparatus as an embodiment of the optical disc reproducing apparatus according to the present invention. FIG. 1 is a flowchart showing a processing procedure of a part related to optimization processing at the time of startup (including the time of disk replacement / loading) during operation of the microcomputer (microcomputer) 11 in FIG. FIG. 3 is also a flowchart showing a processing procedure of a part related to the optimization processing at the time of normal reproduction.
The same step numbers in FIG. 1 and FIG. 3 indicate substantially the same processing. On the other hand, FIG. 9 and FIGS.
Are substantially the same, but have no relevance to the step numbers in FIG. 1, FIG. 3, and FIG.

Discs known as DVDs (Digital Video Discs) include a pit-type disc dedicated to reproduction, similar to a conventional audio disc in which only audio is recorded, and a phase-change type optical disc capable of recording and reproduction. When,
There is a so-called write-once type disc that can be written only once. In this embodiment, a description will be given by taking as an example a recordable and reproducible disc having a two-layer laminated structure. That is, in FIG.
There is a track spirally formed from the inner circumference to the outer circumference, and the optical pickup 2 gives a laser beam spot to this track so that bibliographic information, audio information, and video information in a predetermined format can be optically read. Is recorded and played back. This disk 1 is servo-controlled by a servo circuit of a block 10 based on a signal read and reproduced by an optical pickup (optical head) 2,
The spindle motor 3 and the motor driver / tracking / focus control circuit 4 rotate at CLV (constant linear velocity). The optical pickup 2 has a superimposing device 5. The optical head 2 can be moved by the traverse motor 6 in the radial direction of the disk 1.

The optical pickup 2 also has a laser diode for emitting a laser beam to the disk 1. A signal obtained by reproducing optical information recorded on the disk 1 based on the reflected light and a signal obtained by the astigmatism method. It outputs two types of focus error signal detection signals A to D and two types of tracking error signal detection signals E and F of a three-beam method (see FIG. 7 described later). These signals A to F have their frequency characteristics switched and amplified by the head amplifier 8 in accordance with the frequency, and are output to the preamplifier 9 which operates as detection / adjustment means. Further, a signal for driving a laser diode in the optical pickup 2 is applied from the preamplifier 9 to the head amplifier 8.

A temperature sensor 20 for measuring the ambient temperature near the optical pickup 2 and near the disk 1
Is provided. The output signal is A /
It is input to the D converter 11a. The preamplifier 9 has a variable speed transfer controller / memory controller / EFM modulation / demodulation /
The reproduced EFM signal, the focus error signal FEO, the tracking error signal TEO, and the like are output to the error correction / servo circuit block 10. The servo circuit of the block 10 is constituted by, for example, a DSP (Digital Signal Processor). 4MB DRAM
Numeral 13 temporarily stores data when compressing and decompressing data at the time of recording and reproduction. Writing and reading are controlled by the memory controller of the block 10 which has been instructed by the microcomputer 11.

The variable speed transfer controller / memory controller / EFM modulation / demodulation / error correction / servo circuit block 10 encodes the recording data at the time of recording and modulates it to an EFM signal, transfers the data at a variable speed, and transmits the data via the preamplifier 9. Output to the head amplifier 8. This block 10
During reproduction, the EFM signal from the preamplifier 9 is demodulated and error-correction decoded, and data is transferred at a variable speed. The servo circuit of the block 10 controls the optical pickup 2 via the motor driver / tracking / focus control circuit 4 so that the optical pickup 2 performs tracking and focusing on the track of the disk 1 based on the focus error signal FEO and the tracking error signal TEO. . The microcomputer 11 moves the optical pickup 2 near the innermost circumference of the disc 1 (TOC: Table Of C
ontents) to read out necessary ID information, and adjust the offset and balance of the tracking error signal TEO as described later. Compression / decompression control means 14
Is to compress (encode) a recording signal by a predetermined method and expand (decode) a reproduction signal by a predetermined method. Note that an A / D converter and a D / A converter can be provided as needed in the interface between the block 10 and the outside for video signals, audio signals, and ROM signals.

The microcomputer 11 includes an A / D converter 11a for receiving various signals A to F, FEO, TEO, and the like from the preamplifier 9, and a laser diode LD in the optical pickup 2.
For controlling the output power of the laser diode LD by driving the device with a signal corresponding to, for example, a 12-bit PWM signal, and a RAM 1 for a work area or the like.
1c, a ROM 11d for programs and the like, a CPU 11e for performing control as described below, and the like, and these circuits 11a to 11e are connected via a bus 11f.
The RAM 11c has an area for storing the upper and lower peak values of the tracking error signal and the like for the CPU 11e to perform the adjustment described later. The PWM signal from the PWM unit 11b is converted to a DC voltage by a low-pass filter (LPF) 12, applied to a laser power control circuit (not shown), and then a laser diode in the optical pickup 2 is driven via a head amplifier 8. . Microcomputer 1
The input unit 1 is connected to an input unit 16 and a display unit 18 to receive an instruction from a user and display a recording / reproducing state, a control state, and the like.

In the present invention, as shown in the flow chart of FIG. 1, when the servo control means composed of the blocks 4, 10 and the preamplifier 9 needs to be optimized, the optimization is performed. Before the description, the contents of the servo control will be described. First, the configuration of the preamplifier 9 will be described in detail with reference to FIG. RF signals A, B, C, and D input from the optical pickup 2 via the head amplifier 8 are output to the EFM modulation / demodulation / error correction circuit 10 as EFM signals via the information reproduction signal output circuit in the preamplifier 9. . In order to adjust the focus balance, an envelope signal EFMENV of the EFM signal is output from the EF in the preamplifier 9.
It is detected by the MENV detection circuit (see FIG. 7 described later) and output to the A / D converter 11a in the microcomputer 11.

Further, using the output signals A to D of the four-split sensor for detecting the focus error (FE) signal, (A + C−
BD) is calculated, and a focus error (FE) signal is generated. Further, two-part sensors E and F for detecting a tracking error signal from the optical pickup 2 (see FIG. 7).
(FE) is calculated using the output signals E and F of the above, and a tracking error (TE) signal is generated. These two
The known balance, gain, and offset are adjusted for the two error signals (FE, TE), and the adjusted focus error signal FEO and tracking error signal TEO are adjusted.
Is the servo circuit 10 and the A / D converter 11 in the microcomputer 11
output to a.

The CPU 11e in the microcomputer 11 uses these input signals and signals from the block 10 to generate a focus balance signal FBAL, a focus gain signal FG,
A focus offset signal FOFS, a tracking balance signal TBAL, a tracking gain signal TG, a tracking offset signal TOFS, and the like are generated and supplied to the preamplifier 9. The preamplifier 9 uses these signals to adjust the balance, gain, and offset of the focus error signal FE and the tracking error signal TE, and outputs the adjusted focus error signal FEO and tracking error signal TEO from the preamplifier 9. Is done.

Returning to FIG. 1, the procedure of the optimization process at startup by the microcomputer 11 will be described. The flowchart of FIG. 1 shows an example of a procedure for performing an optimization process at the time of starting the optical disc recording / reproducing apparatus of FIG. This flow is started when, for example, the apparatus is turned on and the disc 1 is loaded. First, the input / output unit 16 instructs the optical disk recording / reproducing apparatus to reproduce the information of the first layer or the second layer of the disk 1 (Y1, Y2).
It is determined whether or not 2) has been input (step S1).
In the following description and in step S2 and subsequent steps in FIG. 1, these two layers may be simply referred to as one layer or two layers.

If there is a reproduction request (Y1) for one layer, or if there is no reproduction request for any layer, the optimization processing for one layer is immediately executed (step S2). Executing a one-layer optimization process and a one-layer optimization request flag 1F
Is set to 1. The one-layer optimization request flag 1F and a two-layer optimization request flag 2F described below are both 0 when the power is turned on or when a disc is inserted, 0 when there is an optimization request, and when the optimization process is completed. It becomes 1. The optimization process is performed by controlling the frequency characteristics of a reproduction signal generated from the output signal of the optical head 2. In addition to the control of the frequency characteristics of the reproduction signal, at least one of offset, balance, and gain in tracking control and focus control of the optical head may be adjusted. Details of the optimization processing will be described later. Second in step S1
When there is a reproduction request (Y2) for a layer, the process from step S11 described below is executed.

When step S2 of the optimization processing for the first layer is completed, the optical head 2 is moved to the inner peripheral portion of the disk, and
The TOC of the layer is read (step S3). In the next step S4, the same reproduction request (Y1, Y2) as in step S2
Is determined. When the reproduction request (Y1) for one layer is confirmed again, the process goes to step S5, where data is read from the first layer of the optical disk 1 by the optical head 2 and written to the DRAM 13 as memory means. The data written in the DRAM 13 is read out at a speed lower than the speed at which the data was written, the time axis is changed, the data is decoded and sequentially time-expanded, and output is started as a reproduction signal.

Next, it is checked whether or not data of a certain amount (for example, about 80%) which is relatively close to the capacity is accumulated in the DRAM 13 (step S6). That is, the DRAM 1
Since the data of No. 3 is erased when read, the remaining amount of data decreases as the reading progresses. DRA
If there is no data of a certain amount or more in M13 which is relatively close to the capacity, the process returns to step S5. On the other hand, if the DRAM 13 has data of a certain amount or more which is relatively close to the capacity, it is determined whether or not the two-layer optimization request flag 2F is 1 in step S7. If 2F = 0, that is, if the optimization process has not been executed yet for the two layers, step S
At 8, a two-layer optimization process is performed.

The processing in step S8 is basically the same as step S2 except that the target recording layer is different.
However, while step S2 is executed before the optical head 2 reads out a signal, step S7 is performed in the first
The difference is that the processing is performed in the middle of the reproduction of the data such as the sound and image of the layer.

When 2F = 1 in step S7 or after the end of step S8, a one-track kick is performed in step S9, and the apparatus stands by for the next read timing. Next, it is checked whether or not the data less than a certain amount (for example, 20% of the capacity) close to the empty remains in the DRAM 13 (step S10), and if it remains, the process goes to step S5. On the other hand, when data of a certain amount or more does not remain in the DRAM 13, that is, when the amount of remaining data is small, the process returns to step S 7 and data is newly read from the disk 1. As described above, the process of optimizing the control for the second layer by the servo control means (step S8) is performed when the optical head is in a standby state where the data of the first layer is not being read (pickup) from the disk 1, that is, read first. Since the data of the first layer is time-expanded and reproduced during the reproduction, it is not necessary to interrupt the data reading performed by the optical head 2 one after another.

Returning to step S4, if the request for reproducing the second layer (Y2) has been confirmed, or if there is no request for reproducing any of the layers, the optimization processing for the second layer (step S11) and the reading of the TOC (step S11) are performed. Step S12) is executed. Note that, depending on the disc, the TOC may exist only in the first layer, and in this case, step 12 is omitted. In step S11, the flag 2F is set to 1. When step S12 ends, the same determination as in step S4 is performed in step S13. When the first layer reproduction request (Y1) is confirmed, the process goes to step S5, and the second layer reproduction request (Y2) is confirmed. If so, go to step S14. If there is no request to reproduce any layer, step S1
Repeat 3. Steps S14 to S19 are for performing the optimization processing of the first layer during the reading of the information of the second layer, and are performed by replacing the contents of steps S5 to S10 with the layers, and the description is omitted.

Next, the procedure of the optimization processing at the time of normal reproduction will be described with reference to FIG. The flowchart of FIG. 3 shows an example of a procedure for performing the optimization processing when the optical disc recording / reproducing apparatus of FIG. 2 is in the reproducing mode. This flow is for normal playback and is described separately from the flowchart of FIG. 1 for convenience. However, the two flowcharts of FIGS. Can be optimized. It is assumed that the temperature near the optical disc 1 is detected in real time by the temperature sensor 20 shown in FIG. 2 and is sequentially written to the RAM 11c. Also, the measurement temperature is
It shall be compared to a reference value or to a previously measured temperature in time. Such processing is performed by the microcomputer 11
3 is not shown in FIG. 3.

When the temperature measured by the above-mentioned temperature sensor 20 exceeds the reference value or changes so as to have a difference greater than a predetermined value from the previously measured value, the optimization request flags 1F and 2F are set to 0. Is done. In step S20, it is determined whether the recording layer requested to be reproduced is the first layer or the second layer. In the case of the first layer, the process goes to step S5, and steps S5 and S6 are executed as in FIG. Next, in step S21, it is determined whether or not the optimization process is necessary as a result of the measured temperature. If the optimization process is necessary, the first layer is optimized in step S22, and the flag 1F is set to 1 and the flag 2F is set to 0. If NO in step S21 or after the end of step S22, it is determined in step S7 whether 2F = 1. Since 2F = 0 when passing through step S22,
In step S8, the optimization processing of the second layer is executed. If YES in step S7 or after the end of step S8, a one-track kick is performed (step S9), and it is determined again whether or not the reproduction request is for the first layer (step S23). If the determination is YES, the process returns to step S5 or S21 via step S10.

NO in step S23 or step S20
, That is, when the request for reproducing the second layer is confirmed, the process proceeds to step S14. The flow of step S14 and subsequent steps is a modification of the steps of step S5 and subsequent steps for the reproduction of the second layer. Only the layers are different, and the processing contents correspond. Now, assuming that a rapid temperature change occurs during the reproduction of the second layer, an optimization request is issued in step S24, the optimization process is performed on the second layer in step S25, the flag 2F is set to 1, and the flag 2F is set to 1. Since 1F is set to 0,
Next, when step S16 is executed, the determination becomes NO, and the optimization processing is also executed for the first layer in step S17.

FIG. 4 is a timing chart showing one mode of control according to the flowchart of FIG. 1 (first embodiment of the present invention). This example corresponds to steps S2 to S1 in FIG.
0 and steps S5 to S8, S21 to S23 in FIG.
FIG. 4 shows that S10 is being executed. In FIG. 4, the first layer optimization portion shown on the left side of the portion showing the optical head state is
The portion of the second layer optimization shown on the right side in step S2 in FIG. 1 corresponds to step S8 in FIG. The first layer optimization shown on the right side is the step S in FIG.
The second-layer optimization portion corresponding to step S22 in FIG. 3 and further on the right side (right end) corresponds to step S8 in FIG. In FIG. 4 and FIG. 5, the part of the optimization processing is indicated by hatching.
In the example shown in FIG. 4, if the temperature difference exceeds 30 ° C. at time t1, it is determined that an optimization request has been issued. In the figure, "disc reproduction" refers to reading data from the optical disc 1 (step S5 in FIG. 1, etc.), and "reproduction" in the audio / image reproduction portion refers to an audio / image whose time axis is expanded. It does not mean what is actually provided via an audio playback device and display such as an amplifier and a speaker.

FIG. 5 is a timing chart showing another mode of control according to the flowchart of FIG. 1 (second embodiment of the present invention). The configuration of the second embodiment of the present invention is also substantially the same as the block diagram of FIG. 2, but the temperature sensor 20 is unnecessary in the second embodiment, the third embodiment described later, and the fourth embodiment. In FIG. 5, the first layer optimization part and the second layer optimization part shown in the part indicating the state of the optical head correspond to the optimization processing steps in FIGS. 1 and 3 as in FIG. In the example shown in FIG. 5, when the error count in the error correction processing in the block 10 in FIG. 2 exceeds a predetermined value at time t2, it is determined that an optimization request is present.

In the figure, "disk reproduction" and "reproduction" in the audio / image reproduction part are the same as those in FIG. Second
In this embodiment, the first embodiment has first detecting means (temperature sensor 20) for detecting the physical state of the optical disc recording / reproducing apparatus itself or the optical disc 1 which is an optical recording medium, and the physical condition detected by the first detecting means. A comparison means (microcomputer 11) for comparing the physical state with a reference value or a value temporally preceding the physical state is provided to determine whether to perform the optimization process. An optimally provided counter means (microcomputer 11) for counting an error signal generated in the error correction means in the block 10 and a comparing means (microcomputer 11) for comparing the number of error signals counted by the counting means with a reference value. It is determined whether or not to perform the conversion process. Therefore, there is no need for a means for monitoring a physical condition such as a temperature sensor.

As a counting means for counting the error signal, an error counter of C1, C2 or C1, C2, C3
The error counter (in the case of DVD-ROM or CDROM) can be provided in the error correction circuit in the block 10 or realized by software of the microcomputer 11. When an IC provided with a counting means for counting such error signals is used as an IC for performing the error correction processing, this can be used. The counting means counts the number of errors at regular intervals, and the count value is compared with a reference value by the counting means. As described above, in the second embodiment, the criterion for determining whether or not there is an optimization request is the first.
This is different from the embodiment. The comparing means is a microcomputer 1
It can be easily realized with one software.

Further, as a third embodiment of the present invention, the second embodiment
There are the following variations of the embodiment. In the third embodiment,
As in the second embodiment, step S in FIG.
8, S22, or S17, S25 is performed. In order to check whether or not the number of errors has fallen below a reference value in the optimization processing, data for which optimization processing is determined to be necessary is performed. The readout of the block is performed again by the optical head (optical pickup 2). That is, by reading the same data again, the number of errors is counted again and compared with the reference value. As a result, if the number of errors is smaller than the reference value, it is determined that there is an improvement, and the optimization process is subsequently performed based on the number of errors. On the other hand, if the number of errors is not smaller than the reference value, it is determined that there is no improvement, and thereafter, the optimization process based on the number of errors is not performed. Such processing can be performed in the flowchart of FIG. 3 instead of or together with the one-track kick in steps S9 and S18. When the disk 1 is replaced, the optimization process at the time of startup is performed according to the flow of FIG.

In the third embodiment, if the number of errors is not less than the reference value after the optimization processing, the reason why the optimization processing is not performed thereafter is as follows. That is, the case where there is no improvement in the number of errors despite the optimization processing means that the disk 1 is extremely deteriorated, the optical pickup 2 is covered with dust, or the temperature or other environmental condition is out of the use range. Therefore, the execution of the optimization process is useless in such a case. Therefore, it is preferable to send an alarm signal from the microcomputer 11 to the display unit 18 to warn the user.

Further, as a fourth embodiment of the present invention, the determination of the presence / absence of an optimization request can be replaced with the presence / absence of a predetermined time. That is, since the environmental conditions of the optical disk recording / reproducing apparatus or the optical disk reproducing apparatus change with time, executing the optimization processing at regular time intervals is one of the preferable aspects of the present invention. In the fourth embodiment, there is no need to provide a detecting means for detecting the physical state of the optical disc recording / reproducing apparatus itself or the optical disc 1 which is an optical recording medium, a counting means for counting error signals, and the like. Since step S6 can be realized only by configuring a timer, the cost can be minimized.

Next, optimization processing common to the above embodiments (steps S2, S8, S11, S17, S22, S25)
Will be described. For example, when performing the optimization processing for the first layer during the reproduction of the first layer, the optimization can be performed while the light spot by the optical pickup remains at that position. It can also be done on the move. Further, when performing the optimization process for the second layer during the reproduction of the first layer, the focus of the light spot by the optical pickup may be controlled to move the light spot in the direction perpendicular to the disc. Alternatively, it can be performed by moving a track to a predetermined area.

In the first embodiment, the temperature sensor is used as the first detecting means for detecting the physical state of the optical disk recording / reproducing apparatus itself or the optical recording medium. However, instead of this or in addition to this, the following is used. May be measured and detected. (1) Humidity change (2) Power supply voltage change (3) Physical change due to impact (4) Resonance state change caused by difference in rotation speed between inner and outer circumferences of disk
(5) Variation of eccentricity and runout of disk (6)
Changes in optical characteristics due to differences in position on the disk (7) Fluctuations in the number of revolutions of the spindle motor (8) Number of times the spindle motor is started (9) Number of times or distance of movement of the optical pickup by the actuator

FIG. 1 shows a method of the optimization process at the time of reproduction.
Since the data is stored in the RAM 13 and read and sent from the block 10 to the preamplifier 9, it is possible to execute the optimization processing of another layer during writing of one layer in the same manner as during reproduction. Although the block diagram of FIG. 2 has both recording and reproducing functions, it is obvious that the present invention is also applied to a device having only one of them. Furthermore, in the above example, the case where the optical disc 1 has two recording layers has been described, but the present invention is applicable to a disc having a multilayer structure of three or more layers. Although the above embodiment has been described with respect to reproduction, it is possible to perform optimization processing on a recordable disc at the time of start-up as in FIG. According to the remaining data amount, a result of detecting a physical state such as a temperature, a result of measuring an elapsed time after the optical disc reproducing apparatus itself is turned on, or performing error correction processing on reproduced data. It is determined whether or not optimization processing is necessary based on a count result of an error signal generated in an error correction unit to be performed. When it is determined that optimization processing is necessary, the optical head is in a standby state and each recording layer, that is, The optimization process can be performed on the recording layer on which writing is currently being performed and the other recording layers in the same manner as in FIG.

Next, a specific method of optimization in each of the above embodiments will be described. FIG. 6 shows the optical disc recording /
FIG. 3 is a block diagram showing a simplified configuration of the playback device among the playback devices. As a specific method of optimization, the optical disk reproducing apparatus shown in FIG. 6 reproduces information from a read-only type CD and DVD, and the DVD includes a read-only two-layer type, a write-once type, The description will be made assuming that the reproduction type is included. FIG. 7 is a circuit diagram showing an optical pickup (PU) shown in FIG. 6 and an arithmetic unit (part of the preamplifier in FIG. 6) which responds to the output signal. 5 shows an example of a circuit for selecting one of the error signals.

Although the reference numerals in FIG. 6 correspond to those in FIG. 2, a block 10 in FIG.
And the microcomputer 11 is the system controller 1
Shown as 1. Since FIG. 6 is a simplified diagram, some elements in FIG. 2 are omitted. The system controller 11 is an EEPROM which is a nonvolatile storage means.
(Electrically erasable, programmable read-only memory) 7, and predetermined data is stored in this memory as described later. Hereinafter, preferred 4 as a specific method for performing optimization in each of the above embodiments of the present invention.
The two methods will be described.

<First Method> FIG. 7 shows a four-split photosensor portion A, B, C, D and a photosensor portion E, which is used in the three-beam method.
F schematically shows a part of the optical pickup 2 having F;
Further, an arithmetic unit (a part of the preamplifier 9) which responds to an output signal from the optical sensor part in the case of the first method for performing optimization is shown. Symbols A to F indicate both these optical sensor portions and their output signals. The adder 20 adds and outputs the output signals of the photosensor portions A and C on the diagonal lines, and the adder 22 adds and outputs the output signals of the photosensor portions B and D on the other diagonals. Is what you do. The adders 24 and 32 are for adding the output signals of the adders 20 and 22 together, and the subtractor 30 is for the adder 2
The output signal of the adder 22 is subtracted from the output signal of 0. Further, the subtracter 28 subtracts the output signal of the optical sensor portion F from the output signal of the optical sensor portion E.
The output signal of the adder 24 is output as it is as an RF signal and is also supplied to an envelope detection circuit 36 as an envelope generating means. Further, the output signal of the adder 24 is supplied to a second envelope detection circuit 37 as a second envelope generating means via the HPF 34. The output signal of the first envelope detection circuit 36 is ENV
The output signal of the second envelope detection circuit 37 is 3
Expressed as TENV. Although the first and second envelope detection circuits 36 and 37 are separately provided in the configuration of FIG. 7, a single envelope detection circuit may be used by switching.

The output signal of the subtractor 28 is supplied to a well-known tracking servo control system and focus servo control system so that the output signal of the subtractor 30 is used as a signal tracking error signal TE and the output signal of the subtracter 30 is used as a focus error signal FE. The output signal of the adder 32 is output as a sum signal (sum all (SA) signal) of the four-divided photosensor portion. The sum signal SA is a main signal for reading the recorded information of the disk and a signal to be measured for disc type discrimination described later. Note that the sum signal SA can be output via an LPF (not shown) in order to remove a high-frequency component that may be included in the sum signal SA.

The system controller 11 has a CPU 11
In addition to the normal system control, discrimination of the disc type, which will be described later, is performed by the operation of e.
The transversal filter (FIG. 8) built in the preamplifier 9 measures the amplitude from the NV and the signal 3TENV.
Adjust) and set the tap gain to the optimal value. Once the data is optimally controlled, the data is stored in the EEPROM 7 which is a nonvolatile storage means.

The focus search is performed by increasing or decreasing the voltage applied to the 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 the optical path. FIG. 9 is a flowchart showing an operation procedure of the microcomputer for determining the type of the disc by focus search as a first method of the present invention, thereafter setting parameters according to the discrimination result, and controlling the frequency characteristics of the reproduced signal. . In FIG. 9, when the control is started, when the power of the reproducing apparatus is turned on, the disk is exchanged, or when data reproduction of another layer is required on the multi-layer type disc, it is determined that the initial setting is necessary ( In step S1), initialization such as clearing predetermined contents of a memory and a buffer (not shown) connected to the microcomputer is performed. Next, in step S2, necessary data is read from the EEPROM 7,
Preamplifier 9 and digital servo control circuit (DSV) 1
Transfer to 0. In step S3, a focus search is started, and in step S4, the amount of reflected light is detected. Based on the detection, the type of the disc is determined. Next, step S5
The parameter is set according to the determination result. Discrimination of the disc type refers to, for example, discrimination between a CD and a DVD, and the method thereof will be described later.

In the next step S6, the focus servo control is turned on. In the following step S7, the spindle motor is started, and in step S8, the tracking servo control is turned on. In the following step S9, the rotation speed of the spindle motor is controlled to the CLV rotation speed, and in step S10, the operating point of the focus servo control is changed, and an offset for obtaining the maximum level of the ENV signal is set. That is, the level of the ENV signal is maximized while adding an offset to the operating point. If the processing in step S10 is not performed, the optical frequency characteristics change, and it is difficult to perform stable control thereafter. For the adjustment or setting of the offset in the focus servo control, a known method disclosed in the prior application of the present inventors (Japanese Patent Application Laid-Open No. 7-235072) can be applied. This is the same for the other methods described later.

In the next step S11, the average value of the ENV signal is obtained, and in step S12, the average value of the 3TENV signal is obtained. The method of calculating the average value in steps S11 and S12 is to measure each signal level a plurality of times and calculate the arithmetic average. Note that the measurement of the signal level may be performed alternately on the two signals so that the influence of a defect or the like affects equally. In the next step S13, 3
The TENV signal is divided by the ENV signal to obtain its quotient X. In step S14, a filter gain is set so as to obtain a desired X stored in the ROM in advance. The gain is set by the preamplifier 9 or DSP / DSV10
The transversal filter is comprised of five taps as shown in FIG. The delay time T of the unit delay element can be switched between 440 ns for a CD and 80 ns for a DVD. This 5
Each gain coefficient of the tap is stored as a table in the ROM of the microcomputer according to the optical characteristics of the optical pickup 2 and the electrical characteristics of the amplifier in advance as an eight-step pattern. Is set. Here, when 3TENV / ENV = X does not pass through the filter of FIG. 8, for example, the gain of G0 is set to 1,
Assuming that 1, G2, G3, and G4 are each 0, and the initial setting value is about X = 0.2, calculation or RO
According to the lookup table stored in M, X =
For example, G0 = 0.02 so as to be about 0.4,
G1 = 0.2, G2 = 1, G3 = 0.2, G4 =
0.02.

Next, in step S15, the optical pickup is moved to a target track, and reproduction and the like are started. These gain values are obtained by writing in the EEPROM 7 the values obtained by the same adjustment as described above in the manufacturing process before shipment of the reproducing apparatus. When the playback device is used by the user, these gain values are read out as a center value at the time of start-up, and when the power is turned on or the disk is inserted in FIG. The operation is performed. Note that once the processing in FIG. 9 has been performed, the value can be normally used. However, when the servo control is turned off again due to the influence of vibration or the like and the servo control is turned on again, it is only necessary to set the adjusted value, and it is not necessary to measure the ENV signal or the like.

Next, the second to fourth systems of the optimization processing according to the present invention will be described. FIG. 10 is a block diagram showing an arithmetic circuit (part of the preamplifier in FIG. 2 or 6) used in the second to fourth systems. Note that the circuit of FIG. 7 can be used for generating the tracking error signal. The circuit shown in FIG. 10 utilizes the circuit shown in FIG. 4 of Japanese Patent Application Laid-Open No. 57-74837, and the same reference numerals in FIG. 7 is different from FIG. 7 in that gate circuits 66 and 70 controlled by the output signals of a falling pulse generating circuit 62 and a rising pulse generating circuit 64 in response to the output signal of the adder 24 are similar to the subtractor 30. The output signal of the function subtracter 26 is gated and applied to the hold circuits 68 and 72, respectively. Hold circuits 68, 72
Are supplied to the + and-input terminals of the subtractor 74, respectively, and the output signal of the subtractor 74 is supplied to one terminal of the switch 60. The output signal of the subtractor 28 is provided to the 0 terminal of the switch 60. Selection of the 1-side terminal and the 0-side terminal of the switch 60 is controlled by a control signal CONT1.

The output signal of the adder 24 is an LPF 58
And an equalizer (EQ) 76 to output a sum signal (SA), an EFM signal, or an EFM plus signal, respectively. The equalizer 76 is provided with a control signal CONT2 for controlling its characteristics. Adder 2
The output signal of No. 4 is output as a 3T signal via a series circuit of the HPF 78 and the LPF 50. The control signals CONT1 and CONT2 are generated by the CPU 11e in the system controller 11, respectively.

Accordingly, when the 0 side of the switch 60 is selected by the control signal CONT1 from the CPU 11e, the tracking error signal TE of the three-beam method is output. 74
A tracking error signal TE similar to that shown in FIG. 4 of JP-A-837 is selected. As described in the publication, a method of obtaining this tracking error signal is that both edges (falling pulse generating circuit 62 and rising pulse generating circuit 64) of the sum signal (the output signal of the adder 24) are used.
Sampling the difference signal (the output signal of the subtracter 26) with the output signal of
This is equivalent to obtaining a value obtained by adding a sign corresponding to the direction of deviation of the beam spot from the track to the two-peak value (see FIG. 5 of the publication).

FIG. 11 shows the second to fourth schemes in FIG.
FIG. 2 is a block diagram showing an internal configuration of a DSP in the DSP DSV10. A PLL circuit 52 that matches the phase of input data read out by the optical pickup 2 and given through the preamplifier 9 in bit units to generate a clock synchronized with a reproduction signal, and the reproduction data and the output signal of the PLL circuit 52 A comparator 54 for comparing with a certain clock and an integrator 56 for integrating an output signal of the comparator 54 are provided. In the second to fourth systems, the focus servo control is turned on, the tracking servo control is turned on, and the signal is reproduced in a state where the spindle is rotated at a predetermined rotation speed so that the jitter of the reproduced signal is optimized. The characteristic of the equalizer 76 is controlled while measuring the jitter.
If the operation of the focusing system is not optimized before the jitter at the equalizer 76 is set to the best point, the optical frequency characteristics fluctuate and the equalizer control becomes meaningless. Therefore, first, the operation of the focus system is optimized. The details of the second to fourth systems will be described below.

<Second System> FIG. 12 is a flowchart showing a control procedure of the microcomputer in the second system. The same steps as those in FIG. 9 are denoted by the same reference numerals, and a description thereof will be omitted. The second method adjusts the best point of focus and the best point of equalizer characteristics based on the measurement of jitter. Since both focus and equalizer characteristics are measured by measuring jitter, the circuit configuration is the simplest. Step S1 in FIG.
At 0A, the operating point of focus servo control is changed and RF
In order to optimize the signal quality, the measured value of the jitter of the reproduced signal is read from the output signal of the integrator 56 shown in FIG. 11, the integrator 56 is reset, and an offset is added to the focus servo control operating point. Measure again and set an offset value that minimizes jitter.

Next, the characteristics of the equalizer 76 are controlled. For this purpose, the measured value of the jitter is read from the output signal of the integrator 56, and the best jitter point is set while switching the equalizer characteristics in several steps. When the initial measured value is G0 = 0.
02, G1 = 0.2, G2 = 1, G3 = 0.2, G
Assuming that 4 = 0.02, for example, G0 = 0.03, so as to further increase the high-frequency amplitude by a calculation or a look-up table previously stored in the ROM.
G1 = 0.3, G2 = 1, G3 = 0.3, G4 =
0.03. Then, the jitter is measured again, and control is performed so that the measured value is minimized (step S1).
1A).

<Third Method> FIG. 13 shows C in the third method.
It is a flowchart which shows the control procedure of PU11e. The same steps as those in FIG. 12 are denoted by the same reference numerals, and a description thereof will be omitted. In the third method, the best focus point is the maximum level of the EFM signal, and the best point of the equalizer characteristics is adjusted based on the measurement of the jitter. In the second method, when the initial quality of the signal is poor, it may not be possible to measure the jitter in a stable manner. is there. In step S10B of FIG. 13, the operating point of the focus servo control is set to SA in order to optimize the quality of the RF signal.
The signal (or 3T signal) is measured, and the SA signal (or 3T signal) is added while adding an offset to the operating point of the focus servo control.
An offset value that maximizes the level of the (T signal) is set.

Next, the characteristic of the equalizer 76 is controlled. For this purpose, the measured value of the jitter is read from the output signal of the integrator 56, and the jitter optimum point is set while switching the equalizer characteristic in several steps. When the initial measured value is G0 = 0.
02, G1 = 0.2, G2 = 1, G3 = 0.2, G
Assuming that 4 = 0.02, for example, G0 = 0.03, G1 so as to further increase the high-frequency amplitude by a calculation or a look-up table previously stored in the ROM.
= 0.3, G2 = 1, G3 = 0.3, G4 = 0.0
3 is assumed. Then, the jitter is measured again, and control is performed so that the measured value is minimized (step S11A).

<Fourth Method> FIG. 14 is a flowchart showing a control procedure of the microcomputer in the fourth method. FIG.
The same steps as those described above are denoted by the same reference numerals, and description thereof will be omitted. In the fourth method, the best focus point is the maximum level of the EFM signal, the best point of the equalizer characteristic is adjusted by the amplitude level adjustment of 3T, and both the best focus point and the best equalizer characteristic point are determined based on the jitter measurement. One adjustment is performed. The adjustment at the maximum level point in the third method is short and stable, but is not always accurate. Therefore, in the fourth method, the coarse adjustment is performed by the level, and the fine adjustment is performed by the jitter. In step S10B of FIG. 14, the operating point of the focus servo control is determined in the same manner as in the third method. In order to optimize the quality of the RF signal, the SA signal (or 3T signal) is measured, and an offset is added to the operating point of the focus servo control. ,
An offset value that maximizes the level of the SA signal (or 3T signal) is set.

Next, in step S11B, RF (EFM +)
The average value of the envelope of the SA signal, which is the entire signal of, is obtained, and the average value of the 3T signal is obtained in step S12B. The method of calculating the average value of steps S11B and S12B is to measure each signal level a plurality of times and calculate the arithmetic average. Note that the measurement of the signal level may be performed alternately on the two signals so that the influence of a defect or the like affects equally. The envelope itself may be used instead of calculating the average value of the envelope of the SA signal. In the next step S13B, the 3T signal is divided by the SA signal to obtain the quotient X. In step S14A, the desired X
Set the filter gain so that Where 3T /
When SA = X does not pass through the filter 25 of FIG. 8, for example, if the gain of G0 is 1, G1, G2, G3, and G4 are each 0 and the initial set value is about X = 0.25, the calculation is as follows. Alternatively, according to a lookup table stored in a ROM, for example, G0 = 0.02, G1 = 0.2, G2 =
1, G3 = 0.2 and G4 = 0.02.

This set value is, for example, divided into eight levels by the microcomputer R
It can be obtained by reading what is stored in the OM in advance. Then, in order to ensure the accuracy of the reproduction signal, the measured value of the jitter of the reproduction signal is read from the output signal of the integrator 56 in FIG. 11 and the integrator 56 is reset so that the jitter is minimized. I do. Initial measurement value is G
0 = 0.02, G1 = 0.2, G2 = 1, G3 =
0.2, G4 = 0.02, calculation or ROM
For example, G0 = 0.0 so as to further increase the high-frequency amplitude by using the lookup table stored in
3, G1 = 0.3, G2 = 1, G3 = 0.3, G4
= 0.03. Then, the jitter is measured again, and control is performed to reduce the measured value to a minimum (step S).
14A).

Next, the disc discriminating step (S4) in each of the flowcharts will be described. here,
The optical pickup 2 is a bifocal type, that is, as shown in JP-A-7-65407 and JP-A-7-98431, an objective lens is provided with two convergence points to be able to cope with disks having different thicknesses. Using
A method for determining the type of a disc will be described. The optical pickup 2 has NA = 0.38 mm and NA = 0.6 mm
At two spots, that is, a plate thickness t1
It is assumed that information is read from a CD of = 1.2 mm and a DVD of t2 = 0.6 mm. The distance between the two focal points is 0.3mm
And When the image is formed simultaneously on the disc surface and signal surface,
The distance between the two focal points cannot be set in the same manner as the thickness of the disk because the disk surface is affected by low frequency modulation and offset.

FIG. 15 is a diagram showing a state in which a laser beam is focused on the disk 1 in such a bifocal optical pickup. 1-a is a disk with t1 = 1.2 mm, 1-b is t2
= 0.6mm disc, 1-c is 0.6mm disc 2
This shows a focused state on a layered disc (interlayer distance t3 = 40 μm), where the leading upper beam is for 1.2 mm and the trailing lower beam is for 0.6 mm. In FIG. 15, α, β,
γ and δ indicate the states in which the objective lens of the optical pickup 2 has moved in the focus direction. FIG. 16 shows FIG.
3 shows various signal waveforms obtained from an output signal when a focus search is performed by the optical pickup 2. That is, the vertical axis in FIG. 16 is voltage, the horizontal axis is time, and p indicates a peak. Since the bifocal optical pickup is constituted by a hologram lens, signals other than the two spots having two focal points are detected as in JP-A-7-98431. Is omitted.

In FIG. 16, 2-a to 2-d correspond to the disk 1-a in FIG. 15, 2-e to 2-h correspond to the disk 1-b in FIG. 15, and 2-i to 2-l correspond to the disk 1-b. These correspond to the disks 1-c in FIG. In addition, the sum signal SA of FIG.
a, 2-e, 2-i, and the focus error signal FE is
6 are 2-b, 2-f, 2-j, and the signal obtained as a result of comparing the sum signal SA with the threshold shown by the dotted line is shown in FIG.
The signals obtained by comparing the focus error signal FE with the threshold shown by the dotted line are 2-d, 2-h, and 2-l in FIG. is there.

The focus search is performed by moving the objective lens, which is a part of the optical system of the optical pickup 2, along the optical path by increasing or decreasing the voltage applied to the focus coil of the optical pickup 2. In the waveform 2-a in FIG. 16, the peak on the left side in the figure is obtained in the state α of the disk 1-a in FIG. 15, and the peak on the right side is obtained in the state β in the same manner. Thus, the peaks in FIG. 16 correspond to α and β in FIG.
The four peaks in waveforms 2-i to 2-l are shown in FIG.
These correspond to α, β, γ, and δ of the 1-c disk. FIG.
7 is a waveform diagram showing a focus search in a two-layer disc, and shows a case where servo control is turned on in the second layer of a 0.6 mm disc. 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.

FIG. 18 shows a C for judging the disc type by the focus search shown in FIG. 15 and FIG.
It is a flowchart which shows the operation | movement procedure of PU11e. That is, the flowchart of FIG. 18 corresponds to steps S3 to S6 in FIGS. 9 and 12 to 14 corresponding to each method.
3 shows an example of a portion corresponding to. The switch 60 shown in FIG. 10 is controlled by using the disc type determination result, and one of the three-beam method and the phase difference method tracking error signal is selected by the microcomputer. FIG.
In this example, this flow is started when the power of the reproducing apparatus is turned on, the disc is exchanged, or data reproduction of another layer is required on the multi-layer type disc. First, the memory connected to the CPU 11e In step S1A, initialization such as clearing predetermined contents of the buffer and the buffer is performed, and then focus search is started in step S15A, the contents of the registers storing the peak voltages V1, V2, and V3 are set to 0, and the timer is started.

Next, in step S16, digital values obtained by A / D converting the voltage of the sum signal SA are sequentially read,
The values are sequentially stored in a predetermined A / D conversion register, and are sequentially compared with previous values. In step S17, it is determined whether or not a peak value is detected as a result of the sequential comparison in step S16. If YES, the peak value is set to V1 in step S18.
The result is stored in the register, and if NO, the process returns to step S16. After the end of step S17, A /
The D conversion register is reset.
Steps S20 and S21 similar to step S17 are executed, and the next peak value is stored in the V2 register in step S22.
The D conversion register is reset in step S23. In the next step S24, it is determined whether or not the time measured by the timer has exceeded the set value (overflow). If it has, the process proceeds to step S28, and if not, the process proceeds to step S25. Steps S25 and S26 correspond to the above-described step S, respectively.
The contents are the same as those of 16 and 17, and the peak value is stored in the V3 register in step S27. In step S28, a comparison operation is performed using the peak values V1, V2, and V3 obtained so far.

In the next step S29, V1 is set to a predetermined value Q1.
It is determined whether V2 is smaller than V2 or smaller than a predetermined value Q2. If YES, the process proceeds to an abnormality processing routine of step S34. These predetermined values Q1 and Q2 are values that are sufficiently smaller than the peak value obtained in a focus search on a normal disc. If “NO” in the step S29, it is determined whether or not V1 / V2> Q3 in a step S30 (Q3 is, for example, a value of about 70% of a ratio of V1 to V2 normally obtained with a 1.2 mm thick disk). Predetermined value: This value varies depending on the design of the reproducing apparatus.
The ratio of 1 to V2 can be reversed, and so can the other similar comparison steps). If “YES” in the step S30, it is determined that the current disk has a thickness of 1.2 mm, predetermined parameters are set in a step S40, and then the focus servo control is turned on in a step S31. On the other hand, if NO is determined in the step S30, V2 is determined in a step S32.
/ V1> Q4 (Q4 is, for example, 7 of the ratio of V2 to V1 normally obtained with a disc having a thickness of 0.6 mm).
A predetermined value of about 0%).

If "YES" in the step S32, it is determined that the current disk has a thickness of 0.6 mm, and a step S4 is executed.
In step S3, predetermined parameters are set.
In step 3, a predetermined focus servo control is turned on. on the other hand,
If NO in step S32, V3> V in step S36
1 (when V3 is measured) and whether or not V3> V2 is determined. If YES in step S36,
In step S42, predetermined parameters are set, and then, in step S37, the focus servo control is turned on at the point SC (see waveform 3-e) when the signal shown by 3-C in FIG. 17 becomes the center value. Although not shown, step S31,
The operation of turning on the focus servo control in S33 is also 1
Since the type of disc can be detected during the focus search, the waveform 2
The focus servo control can be turned on immediately after the detection of the peak voltage V2 at -e, and the focus servo control can be turned on even in the reverse focus search.

In the flowchart of FIG. 18, the peak value V4
Is not used, but this is the detection of V3 and its V1, V
If the disc is judged to be a two-layer disc by comparison with
This is because the search time can be shortened by turning on the servo control at the time of V3 before detecting V4. The setting of the predetermined parameters in the above steps S40, S41 and S42 includes the laser power of the optical head, the gain and offset of the circuit for generating the focus error signal and the tracking error signal in the preamplifier 9 in accordance with the disc type determined. Parameters such as balance, switching of equalizer characteristics to be described later in the preamplifier 9 or the DSP / DSV 10, parameters necessary for items such as delay amount of a unit delay element of a transversal filter in the preamplifier 9 or the DSP / DSV 10, tap gain setting, etc. Is set. Here, it is assumed that the equalizer and the transversal filter are included in any block of the preamplifier 9 or the DSP / DSV 10. Although the amplitude of the sum signal SA is measured here, the zero-cross timing of the focus error signal FE may be used when measuring the peak value, or the signal 2 which is the focus error signal FE may be used.
The same applies to the measurement of S-curve voltage values (symmetrical voltage values on one side or both sides) of -b, 2-f, and 2-j.

[0081]

As described above, according to one embodiment of the present invention, the optimization is not performed on all the layers at least after the optical disk reproducing apparatus is started or after the optical recording medium is loaded, but the reproduction is performed on all the layers. First, optimization processing is performed, and the reproduced data is temporarily stored in a memory means, and then read out. During reproduction, the servo control optimization processing for other layers, that is, a transversal filter through which a reproduction signal passes. By adjusting the tap gain, the frequency characteristic of the reproduced signal is optimally controlled, so that the waiting time at the time of starting (including the time of replacing / loading the disk) can be reduced. Also, the physical state of the optical disk reproducing device or the optical recording medium is detected, and the control by the servo control means is optimized according to the detected physical state when the optical head is in a standby state in which the optical disk is not reading data from the optical disk. In the aspect in which the physical state is suddenly changed during reproduction, recording of sound, images, and the like,
The optimization can be performed without interrupting the playback, so that stable playback can be continued thereafter.

The elapsed time since the power of the optical disk reproducing apparatus itself is turned on is measured. When the optical head is in a standby state with respect to the optical disk according to the measured elapsed time, the control by the servo control means is performed. In the aspect of re-adjusting to optimize, even if a sudden change in the physical state occurs during playback, optimization can be performed without interrupting playback of audio, images, etc. Can be continued.

The error signal generated by the error correction means is counted, and the control by the servo control means is optimized in accordance with the counted number of error signals when the optical head is in a standby state with respect to the optical disk. In the mode of re-adjusting, even if a sudden change in the physical state or other undesired phenomena occurs during playback, audio, recording of images, etc., optimization can be performed without interrupting playback, Therefore, stable reproduction can be continued thereafter.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control procedure for realizing an optimization process at the time of startup in an optical disc reproducing apparatus of the present invention.

FIG. 2 is a block diagram showing an optical disc reproducing apparatus as an embodiment of the optical disc reproducing apparatus of the present invention.

FIG. 3 is a flowchart showing a control procedure for realizing an optimization process at the time of normal reproduction in the optical disc reproducing apparatus of the present invention.

FIG. 4 is a timing chart showing one mode (first embodiment) of the control according to the flowcharts of FIGS. 1 and 3;

FIG. 5 is a timing chart showing another mode (second embodiment) of the control according to the flowcharts of FIGS. 1 and 3;

FIG. 6 is a simplified block diagram of FIG. 2;

FIG. 7 is a circuit diagram showing an optical pickup and an arithmetic unit (part of the preamplifier in FIG. 6) used in a first system of an optimization process performed in response to an output signal of the optical pickup in the embodiment of the optical disk reproducing apparatus of the present invention; It is.

FIG. 8 is a block diagram illustrating a configuration of a transversal filter included in the preamplifier or the DSP / DSV of FIG. 6;

FIG. 9 is a flowchart showing a first method of optimization processing in the processing procedure of the operation of the microcomputer used in the system controller in FIG. 6;

FIG. 10 is a circuit diagram showing an optical pickup of the optical disk reproducing apparatus of the present invention and an arithmetic unit (part of the preamplifier in FIG. 6) used in second to fourth systems of an optimization process performed in response to an output signal thereof; is there.

FIG. 11 is a circuit diagram showing a jitter measuring circuit used in the second to fourth systems of the optimization processing in the optical disc reproducing apparatus of the present invention.

FIG. 12 is a flowchart showing a second method of the optimization processing in the processing procedure of the operation of the microcomputer used in the system controller in FIG. 6;

13 is a flowchart showing a third method of the optimization processing in the processing procedure of the operation of the microcomputer used in the system controller in FIG. 6;

14 is a flowchart showing a fourth method of the optimization processing in the processing procedure of the operation of the microcomputer used in the system controller in FIG. 6;

FIG. 15 is a diagram showing a state in which a laser beam is focused on a disk in a bifocal optical pickup.

16 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.

FIG. 17 is a waveform diagram showing a focus search in a two-layer disc.

FIG. 18 shows an operation of a microcomputer (microcomputer) used for the system controller in FIG. 6;
9 is a flowchart illustrating a processing procedure for discriminating a disc type.

[Explanation of symbols]

Reference Signs List 1 optical disk 2 optical pickup (optical head) 3 spindle motor 4 motor driver / tracking / focus control circuit (constituting servo control means with DSV 10 and focusing search means with system controller 11) 7 EEPROM (non-volatile storage means) 9 Preamplifier (including each arithmetic means, DSP / DS
V10 constitutes signal processing means) 10 Variable speed transfer controller / memory controller /
EFM modulation / demodulation / error correction / servo circuit block (Fig. 6
11 corresponds to a digital signal processor (DSP) / digital servo (DSV) control circuit, constitutes an error correction means, and constitutes a servo-on means together with a system controller. 11 Microcomputer (corresponds to the system controller of FIG. Means, recording layer determining means, optimizing means, controlling means, standby state detecting means, comparing means, second controlling means, time measuring means, counting means, controlling / warning means, controlling means, comparing means, calculating means. 11e CPU 12, 50, 58 LPF (low-pass filter) 13 DRAM (memory means) 14 Compression / expansion control means (time axis changing means) 16 input means 18 display means 20 Temperature sensor (physical state detection means) 20, 22 , 24, 32 Adder 25 Transversal filter (frequency characteristic changing means) 26, 2 , 30, 74 Subtractor 34, 78 HPF (high-pass filter: filter means) 36, 37 Envelope detector (envelope generating means) 52 PLL circuit (clock extracting means) 54 Comparator 56 Integrator (jitter measuring means together with comparator 54) 60 switch 62, 64 pulse generation circuit 66, 70 gate circuit 68, 72 hold circuit 76 equalizers A, B, C, D 4-split optical sensor portion used for phase difference method E, F 2 used for 3-beam method One sensor part

Claims (17)

[Claims] 1. A first layer and a second layer of a disk-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required And when the reproduction of information is requested for the first layer, an optimization process is performed on the first layer by the optimizing means, and a predetermined amount of information is read from the first layer to read the memory means. And when the memory unit stores information equal to or greater than a first predetermined amount, the optical head is set to the standby state, the information is read out from the memory unit to perform a reproducing operation, and the second layer is read. Is controlled so that the optimizing process is performed by the optimizing unit, and when the amount of information stored in the memory unit is smaller than a second predetermined amount, a predetermined amount of information is read from the first layer. When the information stored in the memory means is requested to be reproduced from the second layer, an optimization process is performed by the optimizing means on the second layer to read a predetermined amount of information from the second layer. When the optical head is in the standby state, the information is read out from the memory means, and the reproducing operation is performed when the information is stored in the memory means. Do,
Control is performed so that the optimizing unit performs optimization processing on the recording layers other than the second layer, and when the amount of information stored in the memory unit becomes smaller than a second predetermined amount, the second layer starts the second layer. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the quantitative information is read and stored in the memory means, and the optimizing means comprises: Signal quality detection means for detecting the quality of a reproduced signal that is an output signal from the head, and means for optimizing the quality of the output signal of the optical head according to the signal quality detected by the signal quality detection means, An optical disk reproducing apparatus comprising: 2. The frequency characteristic of the reproduced signal is detected by detecting a jitter or a frequency characteristic of the reproduced signal and optimizing a quality of an output signal of the optical head. Optical disc playback device. 3. A first layer and a second layer of a disk-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required And when the reproduction of information is requested for the first layer, an optimization process is performed on the first layer by the optimizing means, and a predetermined amount of information is read from the first layer to read the memory means. And when the memory unit stores information equal to or greater than a first predetermined amount, the optical head is set to the standby state, the information is read out from the memory unit to perform a reproducing operation, and the second layer is read. Is controlled so that the optimizing process is performed by the optimizing unit, and when the amount of information stored in the memory unit is smaller than a second predetermined amount, a predetermined amount of information is read from the first layer. When the information stored in the memory means is requested to be reproduced from the second layer, an optimization process is performed by the optimizing means on the second layer to read a predetermined amount of information from the second layer. When the optical head is in the standby state, the information is read out from the memory means, and the reproducing operation is performed when the information is stored in the memory means. Do,
Control is performed so that the optimizing unit performs the optimizing process on the recording layers other than the second layer. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the quantitative information is read and stored in the memory means, and the optimizing means comprises: Frequency characteristic changing means capable of changing a frequency characteristic of a reproduction signal which is an output signal from a head; filter means for extracting a highest frequency band of the reproduction signal; first envelope generation for obtaining an amplitude of the reproduction signal Means, a second envelope generating means for obtaining an amplitude of an output signal of the filter means, and an amplitude equal to the amplitude obtained by the first and second envelope generating means. Comparing means for comparing the optical disk reproducing apparatus, characterized in that the control means for generating a control signal for changing the frequency characteristic of the frequency characteristic changing means according to a result of comparison, with at the comparison means. 4. A first layer and a second layer of a disk-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required And when the reproduction of information is requested for the first layer, an optimization process is performed on the first layer by the optimizing means, and a predetermined amount of information is read from the first layer to read the memory means. And when the memory unit stores information equal to or greater than a first predetermined amount, the optical head is set to the standby state, the information is read out from the memory unit to perform a reproducing operation, and the second layer is read. Is controlled so that the optimizing process is performed by the optimizing unit, and when the amount of information stored in the memory unit is smaller than a second predetermined amount, a predetermined amount of information is read from the first layer. When the information stored in the memory means is requested to be reproduced from the second layer, an optimization process is performed by the optimizing means on the second layer to read a predetermined amount of information from the second layer. When the optical head is in the standby state, the information is read out from the memory means, and the reproducing operation is performed when the information is stored in the memory means. Do,
Control is performed so that the optimizing unit performs the optimizing process on the recording layers other than the second layer. Control means for controlling at least after starting the optical disc reproducing apparatus or after loading the optical recording medium, so that the quantitative information is read and stored in the memory means, and the optimizing means comprises: Frequency characteristic changing means capable of changing a frequency characteristic of a reproduced signal which is an output signal from the head; clock extracting means for extracting a clock from the reproduced signal; clock extracted by the clock extracting means and the reproduced signal Measuring means for measuring the jitter of the measuring means; comparing means for comparing the jitter measured by the measuring means with a predetermined value; Optical disk reproducing apparatus, wherein a control means for generating a control signal for changing the frequency characteristic of the frequency characteristic changing means comprises in accordance with the. 5. A first layer and a second layer of a disk-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required And when the reproduction of information is requested for the first layer, an optimization process is performed on the first layer by the optimizing means, and a predetermined amount of information is read from the first layer to read the memory means. And when the memory unit stores information equal to or greater than a first predetermined amount, the optical head is set to the standby state, the information is read out from the memory unit to perform a reproducing operation, and the second layer is read. Is controlled so that the optimizing process is performed by the optimizing unit, and when the amount of information stored in the memory unit is smaller than a second predetermined amount, a predetermined amount of information is read from the first layer. When the information stored in the memory means is requested to be reproduced from the second layer, an optimization process is performed by the optimizing means on the second layer to read a predetermined amount of information from the second layer. When the optical head is in the standby state, the information is read out from the memory means, and the reproducing operation is performed when the information is stored in the memory means. Do,
Control is performed so that the optimizing unit performs the optimizing process on the recording layers other than the second layer. Control means for controlling at least after starting the optical disc reproducing apparatus or after loading the optical recording medium, so that the quantitative information is read and stored in the memory means, and the optimizing means comprises: Frequency characteristic changing means capable of changing a frequency characteristic of a reproduction signal which is an output signal from a head; filter means for extracting a highest frequency band of the reproduction signal; first envelope generation for obtaining an amplitude of the reproduction signal Means, a second envelope generating means for obtaining an amplitude of an output signal of the filter means, and an amplitude obtained by the first and second envelope generating means. A first storage unit for storing each of them; a calculation unit for comparing the amplitudes stored in the first storage unit; a non-volatile second storage unit for storing a calculation result by the calculation unit; 2. An optical disc reproducing apparatus, comprising: a control unit for generating a control signal for changing a frequency characteristic of the frequency characteristic changing unit in accordance with the calculation result stored in the storage unit. 6. A first layer and a second layer of a disc-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required And when the reproduction of information is requested for the first layer, an optimization process is performed on the first layer by the optimizing means, and a predetermined amount of information is read from the first layer to read the memory means. And when the memory unit stores information equal to or greater than a first predetermined amount, the optical head is set to the standby state, the information is read out from the memory unit to perform a reproducing operation, and the second layer is read. Is controlled so that the optimizing process is performed by the optimizing unit, and when the amount of information stored in the memory unit is smaller than a second predetermined amount, a predetermined amount of information is read from the first layer. When the information stored in the memory means is requested to be reproduced from the second layer, an optimization process is performed by the optimizing means on the second layer to read a predetermined amount of information from the second layer. When the optical head is in the standby state, the information is read out from the memory means, and the reproducing operation is performed when the information is stored in the memory means. Do,
Control is performed so that the optimizing unit performs the optimizing process on the recording layers other than the second layer. Control means for controlling at least after starting the optical disc reproducing apparatus or after loading the optical recording medium, so that the quantitative information is read and stored in the memory means, and the optimizing means comprises: Frequency characteristic changing means capable of changing a frequency characteristic of a reproduced signal which is an output signal from the head; clock extracting means for extracting a clock from the reproduced signal; clock extracted by the clock extracting means and the reproduced signal Measuring means for measuring the jitter of the first, second storing means for storing the jitter measured by the measuring means, and the jitter stored in the first storing means. An optical disc, comprising: comparison means for comparing the frequency characteristic with a predetermined value; and control means for generating a control signal for changing a frequency characteristic of the frequency characteristic changing means in accordance with a result of the comparison by the comparison means. Playback device. 7. A first layer and a second layer of a disk-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required Standby state detecting means for detecting which of the recording layers of the optical disk the optical head is reading or the standby state; and when reproduction of information is required for the first layer. Performs an optimization process by the optimization unit on the first layer, reads a predetermined amount of information from the first layer, stores the information in the memory unit, reads information from the memory unit, and performs a reproduction operation. And controlling the first layer to perform the optimization process by the optimizing means for the second layer in the standby state, and when the reproduction of the information for the second layer is requested, The optimization processing is performed on the second layer by the optimization means,
A predetermined amount of information is read out from the layer and stored in the memory means, and the information is read out from the memory means to perform a reproducing operation. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the optimizing means performs the optimizing process, and the optimizing means comprises an output signal from the optical head. Signal quality detecting means for detecting the quality of the reproduced signal, and means for optimizing the quality of the output signal of the optical head according to the signal quality detected by the signal quality detecting means. Optical disk playback device. 8. The apparatus according to claim 1, wherein a jitter or a frequency characteristic of the reproduced signal is detected as the quality of the reproduced signal, and the frequency characteristic is optimized to optimize the quality of the output signal of the optical head. Optical disc playback device. 9. A first layer and a second layer of a disc-shaped optical recording medium.
An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a layer, a memory means for temporarily holding reproduction data, and a memory for reading data from the optical head when reading from the optical disk. Time axis changing means for reading data from the memory means at a speed lower than the writing speed to the means; servo control means for performing tracking control of the optical head and / or focus control of the optical head; Means for setting a standby state when a read operation is not performed for the plurality of recording layers; and optimizing means for optimizing control by the servo control means for each of the plurality of recording layers; Recording layer determining means for determining which of the recording layers from which information reproduction is required Standby state detecting means for detecting which of the recording layers of the optical disk the optical head is reading or the standby state; and when reproduction of information is required for the first layer. Performs an optimization process by the optimization unit on the first layer, reads a predetermined amount of information from the first layer, stores the information in the memory unit, reads information from the memory unit, and performs a reproduction operation. And controlling the first layer to perform the optimization process by the optimizing means for the second layer in the standby state, and when the reproduction of the information for the second layer is requested, The optimization processing is performed on the second layer by the optimization means,
A predetermined amount of information is read out from the layer and stored in the memory means, and the information is read out from the memory means to perform a reproducing operation. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the optimization processing is performed by the optimization means, and wherein the optimization means outputs an output signal from the optical head. Frequency characteristic changing means capable of changing the frequency characteristic of the reproduced signal, filter means for extracting the highest frequency band of the reproduced signal, first envelope generating means for obtaining the amplitude of the reproduced signal, and the filter Second envelope generating means for obtaining the amplitude of the output signal of the means, and the amplitude obtained by the first and second envelope generating means. Comparing means for comparing the optical disk reproducing apparatus, characterized in that the control means for generating a control signal for changing the frequency characteristic of the frequency characteristic changing means according to a result of comparison, with at the comparison means. 10. An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein said memory means temporarily stores reproduced data. A time axis changing unit that reads data from the memory unit at a speed lower than a speed of writing read data from the optical head to the memory unit when reading from the optical disk; tracking control of the optical head and / or the light A servo control unit for performing focus control of a head; and a unit for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk. Optimizing means for optimizing each recording layer of the recording layers, and any one of the plurality of recording layers Recording layer determining means for determining whether information reproduction is required; standby state detecting means for detecting whether the optical head is reading data from any of the recording layers of the optical disk or is in the standby state; When information reproduction is requested for the first layer, an optimization process is performed on the first layer by the optimizing unit, a predetermined amount of information is read from the first layer, and the information is read to the memory unit. Storing and reading information from the memory means to perform a reproducing operation, and controlling the first layer to perform an optimization process by the optimizing means for the second layer in the standby state; When reproduction of information is required for two layers, the second layer is subjected to optimization processing by the optimizing means, and
A predetermined amount of information is read out from the layer and stored in the memory means, and the information is read out from the memory means to perform a reproducing operation. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the optimizing means performs the optimizing process, and the optimizing means comprises an output signal from the optical head. Frequency characteristic changing means capable of changing the frequency characteristic of the reproduced signal, clock extracting means for extracting a clock from the reproduced signal, and measuring the jitter of the clock extracted by the clock extracting means and the reproduced signal. Measuring means; comparing means for comparing the jitter measured by the measuring means with a predetermined value; Optical disk reproducing apparatus, wherein a control means for generating a control signal for changing the frequency characteristic of the frequency characteristic changing means comprises in accordance with the. 11. An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein said memory means temporarily stores reproduced data. A time axis changing unit that reads data from the memory unit at a speed lower than a speed of writing read data from the optical head to the memory unit when reading from the optical disk; tracking control of the optical head and / or the light A servo control unit for performing focus control of a head; and a unit for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk. Optimizing means for optimizing each recording layer of the recording layers, and any one of the plurality of recording layers Recording layer determining means for determining whether information reproduction is required; standby state detecting means for detecting whether the optical head is reading data from any of the recording layers of the optical disk or is in the standby state; When information reproduction is requested for the first layer, an optimization process is performed on the first layer by the optimizing unit, a predetermined amount of information is read from the first layer, and the information is read to the memory unit. Storing and reading information from the memory means to perform a reproducing operation, and controlling the first layer to perform an optimization process by the optimizing means for the second layer in the standby state; When reproduction of information is required for two layers, the second layer is subjected to optimization processing by the optimizing means, and
A predetermined amount of information is read out from the layer and stored in the memory means, and the information is read out from the memory means to perform a reproducing operation. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the optimizing means performs the optimizing process, and the optimizing means comprises an output signal from the optical head. Frequency characteristic changing means capable of changing the frequency characteristic of the reproduced signal, filter means for extracting the highest frequency band of the reproduced signal, first envelope generating means for obtaining the amplitude of the reproduced signal, and the filter A second envelope generating means for obtaining an amplitude of an output signal of the means, and an amplitude obtained by the first and second envelope generating means. A first storage unit for storing each of them; a calculation unit for comparing the amplitudes stored in the first storage unit; a non-volatile second storage unit for storing a calculation result by the calculation unit; 2. An optical disc reproducing apparatus, comprising: a control unit for generating a control signal for changing a frequency characteristic of the frequency characteristic changing unit in accordance with the calculation result stored in the storage unit. 12. An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein said memory means temporarily stores reproduced data. A time axis changing unit that reads data from the memory unit at a speed lower than a speed of writing read data from the optical head to the memory unit when reading from the optical disk; tracking control of the optical head; A servo control unit for performing focus control of a head; and a unit for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disk, wherein the control by the servo control unit is performed by the plurality of units. Optimizing means for optimizing each recording layer of the recording layers, and any one of the plurality of recording layers Recording layer determining means for determining whether information reproduction is required; standby state detecting means for detecting whether the optical head is reading data from any of the recording layers of the optical disk or is in the standby state; When information reproduction is requested for the first layer, an optimization process is performed on the first layer by the optimizing unit, a predetermined amount of information is read from the first layer, and the information is read to the memory unit. Storing and reading information from the memory means to perform a reproducing operation, and controlling the first layer to perform an optimization process by the optimizing means for the second layer in the standby state; When reproduction of information is required for two layers, the second layer is subjected to optimization processing by the optimizing means, and
A predetermined amount of information is read out from the layer and stored in the memory means, and the information is read out from the memory means to perform a reproducing operation. Control means for controlling at least after activation of the optical disc reproducing apparatus or after loading of the optical recording medium so that the optimization processing is performed by the optimization means, and wherein the optimization means outputs an output signal from the optical head. Frequency characteristic changing means capable of changing the frequency characteristic of the reproduced signal, clock extracting means for extracting a clock from the reproduced signal, and measuring the jitter between the clock extracted by the clock extracting means and the reproduced signal. Measuring means; first storage means for storing jitter measured by the measuring means; and jitter stored in the first storage means. An optical disc, comprising: comparison means for comparing the frequency characteristic with a predetermined value; and control means for generating a control signal for changing a frequency characteristic of the frequency characteristic changing means in accordance with a result of the comparison by the comparison means. Playback device. 13. A physical state detecting means for detecting a physical state of the optical disk reproducing apparatus itself or the optical recording medium; and a physical value detected by the physical state detecting means as a reference value or the physical state. A comparing means for comparing the value with the previous time value, and wherein the detected physical state exceeds the reference value in response to the comparing means and the standby state detecting means, or the temporal state of the physical state When the optical head has a difference equal to or more than a predetermined value from the previous value, when the optical head is in the standby state, the optimization is performed to optimize the control by the servo control means for each of the recording layers. 13. The optical disk reproducing apparatus according to claim 7, further comprising a second control unit for controlling the unit. 14. A time measuring means for measuring an elapsed time after power is supplied to the optical disc reproducing apparatus itself; a comparing means for comparing the elapsed time measured by the time measuring means with a reference value; In response to the means and the standby state detecting means, when the measured elapsed time exceeds the reference value, when the optical head is in the standby state, the control by the servo control means is performed for each of the recording layers. 13. The optical disk reproducing apparatus according to claim 7, further comprising: a second control unit that controls the optimizing unit for optimizing. 15. An error correction means for performing error correction processing on reproduced data; a counting means for counting the number of error signals generated in the error correction means; and a reference to the number of error signals counted by the counting means. A comparing unit that compares the number of error signals counted in response to the comparing unit and the standby state detecting unit, when the counted number of error signals exceeds the reference value, when the optical head is in the standby state, 13. The optical disk reproducing apparatus according to claim 7, further comprising: a second control unit that controls the optimization unit so as to optimize control of the servo control unit for each of the recording layers. 16. An optical disk reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disk-shaped optical recording medium, wherein the memory means temporarily stores reproduced data. A time axis changing unit that reads data from the memory unit at a speed lower than a speed of writing read data from the optical head to the memory unit when reading from the optical disk; tracking control of the optical head and / or the light A method for optimizing servo control of an optical disc reproducing apparatus, comprising: servo control means for performing focus control of a head; and means for setting the optical head to a standby state when the optical head is not performing a read operation on the optical disc. At least after starting the optical disc reproducing apparatus or after loading the optical recording medium, Determining which of the recording layers the information reproduction is required from; and executing the servo control optimization process for the first layer when the information reproduction is required for the first layer. Reading a predetermined amount of information from the first layer and storing the information in the memory means; and when the memory means stores a predetermined amount of information or more, the optical head is in the standby state. Reading information from the memory means as a state and performing a reproducing operation, and executing the optimization processing on the second layer; and when the amount of information stored in the memory means becomes smaller than a second predetermined amount. Reading information from the first layer and storing the information in the memory means; and when reproduction of information is requested for the second layer, the information is read to the second layer. Executing the optimization process; reading out a predetermined amount of information from the second layer and storing the information in the memory means; and storing at least a first predetermined amount of information in the memory means. When the optical head is in the standby state, the information is read out from the memory unit to perform a reproducing operation, and the optimization process is performed on a recording layer other than the second layer. Reading the predetermined amount of information from the second layer and storing it in the memory means when the amount of information becomes smaller than the second predetermined amount, and executing the optimization process Performing focus servo control on the optical head, performing tracking servo control on the optical head, and optimizing the quality of the reproduced signal. Obtaining the amplitude of the reproduced signal; filtering the highest frequency band of the reproduced signal; and obtaining the amplitude of the output signal of the highest frequency band extracted in the filtering step. Storing the amplitudes respectively, an arithmetic operation for performing an operation for comparing the stored amplitudes, and a control for changing the frequency characteristic of the frequency characteristic changing means in accordance with the operation result obtained in the operation step. Generating a signal. The method for optimizing servo control of an optical disc reproducing apparatus, comprising: 17. An optical disc reproducing apparatus for reproducing information recorded on a plurality of recording layers including a first layer and a second layer of a disc-shaped optical recording medium, wherein said memory means temporarily stores reproduced data. A time axis changing unit that reads data from the memory unit at a speed lower than a speed of writing read data from the optical head to the memory unit when reading from the optical disk; tracking control of the optical head; A method for optimizing servo control of an optical disc reproducing apparatus, comprising: servo control means for performing focus control of a head; and means for setting a standby state when the optical head is not performing a read operation on the optical disc. At least after starting the optical disc reproducing apparatus or after loading the optical recording medium, Determining which of the recording layers the information reproduction is required from; and executing the servo control optimization process for the first layer when the information reproduction is required for the first layer. Reading a predetermined amount of information from the first layer and storing the information in the memory means; and when the memory means stores a predetermined amount of information or more, the optical head is in the standby state. Reading information from the memory means as a state and performing a reproducing operation, and executing the optimization processing on the second layer; and when the amount of information stored in the memory means becomes smaller than a second predetermined amount. Reading information from the first layer and storing the information in the memory means; and when reproduction of information is requested for the second layer, the information is read to the second layer. Executing the optimization process; reading out a predetermined amount of information from the second layer and storing the information in the memory means; and storing at least a first predetermined amount of information in the memory means. When the optical head is in the standby state, the information is read out from the memory unit to perform a reproducing operation, and the optimization process is performed on a recording layer other than the second layer. Reading the predetermined amount of information from the second layer and storing it in the memory means when the amount of information becomes smaller than the second predetermined amount, and executing the optimization process Performing focus servo control on the optical head, performing tracking servo control on the optical head, and optimizing the quality of the reproduced signal. Measuring the jitter of the reproduced signal; storing the measured jitter; changing the frequency characteristic of the frequency characteristic changing unit; and measuring the jitter of the reproduced signal again. A step of comparing the jitter measured first and the jitter measured later; and a control step of generating a control signal for changing a frequency characteristic of the frequency characteristic changing unit according to a result of the comparison. A method for optimizing servo control of an optical disk reproducing device.