JP3373417B2 - Recording / reproducing apparatus for optical information recording medium and focus control method therefor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium reproducing apparatus for reading and reproducing recorded information from an optical information recording medium in which information is recorded on a disk-shaped medium by means of pits or the like.
Alternatively, the present invention relates to a recording / reproducing apparatus capable of further recording information (hereinafter, simply referred to as a recording / reproducing apparatus for an optical information recording medium), and particularly to an optical information recording for recording / reproducing information on a land-groove type medium. The present invention relates to an improved structure of a medium recording / reproducing apparatus and a method of controlling a focus position which is a focus of an optical reproducing means in the apparatus.

[0002]

Conventionally, from the optical information recording medium recording the by Rijo report that by utilizing a phase change, etc. on a disc-shaped optical recording medium to form pits, reads the recording information optically Various types of recording / reproducing apparatuses for reproducing an optical information recording medium are known and are already in practical use. Further, particularly in recent years, as an optical recording medium capable of recording a large amount of information by increasing the information recording density, for example, a DV
A so-called D (digital video disk) has been proposed and has attracted attention, and a part of a reproducing device for reading and reproducing the recorded information is already on the market.

By the way, in such a high density recording medium including a DVD or the like, in order to increase the information recording density on the disk-shaped medium, a laser beam having a shorter wavelength than the conventional one is used as an optical reproducing means. Further, in order to improve the track pitch density, uneven portions called land areas and groove areas are formed on the recording surface of the medium, and information is recorded in these areas. The land area and the groove area alternately appear for each turn following the tracking operation by the optical pickup which is an optical reproducing means. Also, as such a high-density recording medium, various recording such as a recording medium capable of reproducing only recorded information, a recording medium capable of recording once, and a recording medium capable of recording a plurality of times, etc. A medium has been proposed. The characteristics of these various recording media are different, especially in their reflectance.

On the other hand, in the recording / reproducing apparatus of the optical information recording medium for reproducing the recorded information from the high density recording medium in which the concave and convex portions called the land area and the groove area are formed, the optical reproduction is conventionally performed. The focus position of the means is controlled by synchronizing with an address signal pre-recorded in an area formed between the land area and the groove area, that is, a so-called pit address area, while the land is rotated every turn. The focus position for the area and the focus position for the groove area are alternately switched and controlled.

[0005]

However, in the high-density recording medium as described above, in order to accurately reproduce information recorded at high density, an optical pickup, which is an optical reproducing means thereof, particularly, It is necessary to control the focus position of the focus lens more precisely. Normal,
In a recording / reproducing apparatus for an optical information recording medium, the focus position is adjusted so as to be controlled to an optimum position obtained in advance at the time of shipping, however, for example, the type and state of the recording medium are adjusted. Moreover, it is important to control the focus position to an optimum position that suits the operating environment of the device, including the temperature, and for that purpose, based on the recorded information etc. actually reproduced by the device. To correct the focus position to the optimum position,
For example, it is performed by adopting a control that adopts learning control or the like.

However, as described above, when the optical pickup is focused only on the focus position for information reproduction by the focus position control such as the learning control and the focus position is controlled to a more optimum position, however, however, However, a problem will occur in reproducing the address information recorded in the pit address area formed between the land area and the groove area.

That is, as described above, the focus position of the optical pickup is controlled by alternately switching between the focus position for the land area and the focus position for the groove area in synchronization with the address signal of the pit address area. Is being done. However, when the focus position of the optical pickup is controlled to an optimum position only for reproducing the recorded information in the land area or groove area, the address information in the pit address area cannot be accurately read. Occurs.

However, when the address signal in the pit address area cannot be accurately read in this way, in such an apparatus, various operations including reproduction or recording of information are performed in the address information of the pit address area. Since it is performed based on the above, it becomes impossible to guarantee the operation of the entire recording / reproducing apparatus including the tracking control of the optical pickup, and therefore the function as the recording / reproducing apparatus cannot be fulfilled.

In view of the above-mentioned prior art, the present invention is based on the above-mentioned recognition by the present inventors, and in particular, an optical information recording in which land areas and groove areas are formed to record information at high density. It is possible to optimally control the focus position of the optical pickup, which is the optical reproducing means, at the time of reading and reproducing recorded information from the medium or reproducing the recorded information or recording the information. It is possible to reliably capture the address information of the pit address area between the area and the groove area, so that the recording / recording of the optical information recording medium capable of excellent reproduction or recording operation under various conditions can be performed. It is an object to propose a reproducing apparatus and a focus control method thereof.

[0010]

First, in order to achieve the above-mentioned object, what is provided by the present invention is to form a land region, a groove region, and between the land region and the groove region. An optical information recording medium for reading out information recorded on a recording surface of an optical information recording medium having a pit address area while controlling the focus position of an optical reproducing means in conformity with the land area and the groove area. In the recording / reproducing apparatus, the focus position of the optical reproducing means in the land area and the groove area is set so that it is always located in the area of the focus position obtained in conformity with the pit address area. This is a focus control method in a recording / reproducing apparatus for an optical information recording medium for reading out.

Further, according to the present invention, in the focus control method in the recording / reproducing apparatus for the optical information recording medium, the focus position obtained in conformity with the pit address area is set to the optical position on the optical information recording medium. This is set and obtained when it is inserted into the information recording medium reproducing apparatus.

Further, according to the present invention, in the focus control method in the recording / reproducing apparatus for the optical information recording medium, the focus position of the optical reproducing means is controlled so as to be respectively adapted to the land area and the groove area. As a method, learning control is adopted.

Further, according to the present invention, in the focus control method in the recording / reproducing apparatus for the optical information recording medium, the focus position of the optical reproducing means is controlled in conformity with the land area and the groove area, respectively. Therefore, the reflection intensity at a predetermined pattern formed on the head portion of each sector on the recording surface of the optical information recording medium is detected, so as to control the focus position based on the detected reflection intensity did.

According to the present invention, again, in order to achieve the above object, optical information including a land area, a groove area, and a pit address area formed between the land area and the groove area is provided. A recording / reproducing apparatus for a recording optical information recording medium, which records information on a recording surface of a recording medium, while controlling the focus position of an optical reproducing means in conformity with the land area and the groove area respectively,
Optical information recording for recording the information by setting the focus position of the optical reproducing means in the land area and the groove area so that it is always located within the area of the focus position obtained by fitting to the pit address area. A focus control method in a medium recording / reproducing apparatus has been proposed.

In addition, according to the present invention, in order to achieve the above object, the land region, the groove region, and
The information recorded on the recording surface of the optical information recording medium having the pit address area formed between the land area and the groove area, the focus position of the optical reproducing means, the land area and the groove area. In the recording / reproducing apparatus of the optical information recording medium which is set and read respectively,
Further, the optical information recording medium is provided with a control means for setting the focus position of the optical reproducing means in the land area and the groove area so as to be located inside the area of the matching focus position in the pit address area. A recording / playback device is proposed.

According to the present invention, in the recording / reproducing apparatus for the optical information recording medium, the control means includes means for optically recognizing the information formed in the pit address area.

Further, according to the present invention, the above-mentioned recording / reproducing apparatus for the optical information recording medium further comprises means for recording information on the recording surface of the optical information recording medium.

According to the invention, in the recording / reproducing apparatus for the optical information recording medium, the information recording means adapts the focus position of the optical reproducing means at the time of information recording in the pit address area. A control means for setting the focus position to be located inside the area of the focus position is provided.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, FIG. 2 attached herewith shows an optical information recording medium such as a DVD disc which is a high density recording medium for reproducing the recorded information by a recording / reproducing apparatus for an optical information recording medium according to an embodiment of the present invention. 100 is shown. Among such optical information recording media, particularly in a recordable medium called DVDRAM, information is formed by forming so-called pits in the recording layer in the transparent substrate by utilizing, for example, phase change due to laser light irradiation. Can be written, and after that,
The recorded information is reproduced by this written pit. Alternatively, in a read-only optical information recording medium called a DVDROM, a recording surface on which information has already been written is irradiated with laser light, and the reflected light reproduces the recorded information.

The optical information recording medium 1 shown in FIG.
00 is, for example, a recordable medium called the above-mentioned DVDRAM, and as shown in the figure, the ROM section 110 in which predetermined control information and the like are recorded in the central part thereof.
And a RAM section 120 around it. In the high density recording medium as described above, the R
In the AM section 120, a spiral track T for continuously recording information on a disk is used as the information recording section.
At the same time that the tracks are formed, this track is formed separately in a so-called land area and a groove area, which is an uneven area, in order to increase the recording density, and enables recording and reading of information.

FIG. 3 shows a cross section of the land area and the groove area of the information recording portion. In this figure, the land area is indicated by the symbol L, while the groove area is indicated by G, and the land area L and the groove area G are alternately formed in the radial direction of the disk-shaped recording medium 100. In addition, so-called pits are formed in each of the land area L and the groove area G as shown by the broken lines in the figure, and information is recorded.

Further, FIG. 4 shows a formation format of the land area L and the groove area G in the high density recording medium. In this figure, the land area L is formed.
Are shown by the shaded areas, while the groove regions G are formed between these shaded areas. The land area L and the groove area G are formed while alternately changing between the land area L and the groove area G in units of one circumference of the disk-shaped recording medium 100. In this figure, the land area L and the groove area G are switched at the boundary of the one-dot chain line. In addition, these land areas L
The groove area G and the groove area G are formed in units called 17 to 34 sectors, each of which is a circumference of the track T on the disk, and a pit address area P is provided between each sector.
It is divided by an area called A. The RAM section 120 in the disk is divided into zones from the inner circumference to the outer circumference. Each zone has the same number of sectors.

FIG. 5 shows a pit address area formed between the land area L and the groove area G. First, FIG. 5A shows a portion (a pit address area of a portion indicated by an alternate long and short dash line in FIG. 4) that transitions from the land area L to the groove area G, and laser light for detecting a recording signal is shown. Will move from the land area L to the groove area G through the pit address area PA, as indicated by the one-dot chain line arrow in the figure.

On the other hand, FIG. 5B shows a portion where the land region L is shifted to the land region L. Here, the laser beam for detecting the recording signal is also indicated by an alternate long and short dash line arrow in the figure. As shown in FIG. 5, for example, the land area L is transferred to the next land area L through the pit address area PA. Needless to say, when the groove area G is moved to the next groove area G, the groove area G also passes through the pit address area PA in the same manner as described above.

As described above, in the recording medium 100 for recording the recording information at a high density, the recording information is alternately recorded in the land area L and the groove area G having different heights, and therefore the recording information is recorded from the recording medium. In order to reliably reproduce the information, an optical pickup, which is an optical reproducing means for reproducing the recorded information by utilizing the reflection of the laser light, for each of the land area L and the groove area G having different heights, In particular, it is necessary to optimally control the focus position of the optical lens (focus lens) for converging and irradiating the laser beam for reproduction on the surface of the recording medium.

At the same time, the pit address area P
As is clear from the figure, A shows the recording medium 100.
The address number above is based on the multiple pit rows P, P ...
It is recorded on both sides. Therefore, in order to reproduce the record information from the recording medium 100, the plurality of pits P, P ... In the pit address area PA.
It is necessary to accurately detect

Therefore, in the present invention, so-called learning control is adopted in order to optimally control the focus position of the optical lens in the optical reproducing means in reproducing the recorded information from the high density recording medium 100. Optimal position control is performed, and the pit address area PA is also used.
Of the optical information recording medium that enables reliable detection of the pits P, P ...
A playback device is provided.

First, the entire construction of a recording / reproducing apparatus for an optical information recording medium according to an embodiment of the present invention is shown in FIG. 6 attached. In this figure, reference numeral 100 indicates
Similarly to the above, a high-density recording medium is shown, and the reference numeral 20
0 passes through a semiconductor laser 210, which is a light emitting element that generates a laser beam having a desired wavelength, a condensing optical lens 220 that makes the emitted laser beam parallel light, and a part of incident light. At the same time, a half mirror 230 for reflecting the other part, a mirror 240 for changing the direction of light, and a focus lens 25 for irradiating the recording surface of the high density recording medium 100 with a laser beam converged to a predetermined beam diameter.
0 shows an optical pickup which is an optical reproducing means including a light receiving element 260 for receiving and detecting the reflected light from the half mirror 230.

Further, in FIG. 6 described above, reference numeral 300
Is a signal processing unit for detecting the light receiving element 260 of the optical reproducing means and converting the reflected light into an electric signal to perform a predetermined process. The signal processing unit 300 is an optical information recording medium reproducing apparatus. Is connected to a microcomputer 400 provided for controlling the whole of the above, including a focus control method described in detail below.
Performs various controls. That is, the microcomputer 400 is further connected to the laser drive circuit 500, the feed control circuit 600, the spindle control circuit 700, and the two-dimensional actuator control circuit 800.

That is, with the above configuration, the microcomputer 400 is the semiconductor laser 210 which is the light emitting element of the optical pickup 200 which is the above optical reproducing means.
To the high density recording medium 10 of the optical reproducing means 200 by controlling the current supplied to the optical reproducing means 200 to control the emission intensity thereof and the rotation of the feed controlling motor 650.
Controls the position of 0 in the radial direction. Reference numeral 660 in the figure is
This is a gear for moving the optical pickup 200 in the radial direction by the rotation of the feed control motor 650.

Further, the microcomputer 400 controls the rotation of the motor 750 that rotationally drives the spindle to control the constant linear velocity CLV (constant linear linear control) widely used in such high density information recording media. Velocity) or ZCL V ( zoned constant linear velocity) is realized. In particular, in the latter ZCL V, Within each zone, by controlling the rotational speed (the angular velocity) constant, changing the rotational speed for each zone. Further, this microcomputer 400 is
The two-dimensional actuator control circuit 800 realizes the focus position control of the focus lens 250 of the optical pickup 200 by an electromagnetic action using, for example, an electromagnetic coil 850 as its operating means. Here, the two-dimensional position control of the focus realized by the two-dimensional actuator control circuit 800 means the high-density recording medium 1 of the focus lens 250.
In addition to position control in the direction perpendicular to the recording surface of No. 00, tracking position control for following the track by minute position adjustment in the radial direction perpendicular to the position is also included.

Next, FIG. 1 attached herewith shows a light receiving element 260 in the optical pickup 200 which is an optical reproducing means in the recording / reproducing apparatus for the optical information recording medium according to the embodiment of the present invention, and its light receiving element 260. A detailed configuration including a signal processing unit 300 that processes a detection signal and its peripheral portion is shown.

As is clear from the figure, this light receiving element 2
Reference numeral 60 is divided into four detectors A, B, C, and D. The reflected light reflected by the recording surface of the high-density recording medium 100 and incident on the light receiving element 260 is divided into each of these divided portions. The detectors convert the electric signals and output the electric signals. In addition, these divided detection units A, B, C, D
The outputs from are input to the adder circuits 301 to 304, and are (A + C), (B + D), (A + D), and (B +), respectively.
C) is added. Further, the outputs from the adder circuits 301 and 302 are input to the adder circuit 305, whereby all the outputs from the detection units A, B, C and D are added to obtain the sum of (A + B + C + D). The signal is output.

The outputs from the adder circuits 301 and 302 are also input to the subtraction circuit 306 at the same time, so that the output is for tracking represented by ((A + C)-(B + D)). The tracking error signal TE, which is the signal of The tracking error signal TE is then passed through a high frequency pass filter (HPF) 307 to obtain an ID signal. In other words, the ID signal is one obtained by reading a signal waveform as shown FIG 5 address number pits P generated in the pit address area PA shown in, the P ..., for example, in FIG. 7 (B) is there. In addition,
The read ID signal is taken into the microcomputer 400 and is recognized as the address number of each sector on the track of the recording surface of the high density recording medium 100.

On the other hand, this tracking error signal TE
At the same time, after passing through the low frequency pass filter (LPF) 308, the offset value from the D / A converter 310 is added by the adder 309. For tracking control in the groove area, first, the polarity of the tracking error signal TE is inverted by the inversion circuit 312, and further output to the two-dimensional actuator control circuit 800 via the switch element 315. On the other hand, for tracking control in the land area, it is then output to the two-dimensional actuator control circuit 800 via the switch element 318. However, one of the switch elements, that is, the logic signal input of the switch element 318 that passes the tracking control signal of the land (L) region is input.
The power unit has a built-in inverting circuit,
The L / G switching signal output from the computer 400
ON / OFF operation is opposite to that of the switch element 315.
It is designed to be. That is, by this, the two-dimensional actuator control circuit 800 alternately receives the tracking control signal in the land (L) region and the tracking control signal in the groove (G) region based on the tracking signal TE.
Output to. This output becomes a TR signal for controlling tracking, and the feed control circuit 600 of FIG. 6 controls the position of the optical reproducing means 200 in the radial direction. An offset value is given to the D / A converter 310 from the microcomputer 400 via the A / D converter. It should be noted that the detailed description thereof is omitted here because it has little relation to the present invention.

On the other hand, the signals (A + D) and (B + C) output from the adder circuits 303 and 304 are input to the subtraction circuit 311, whereby ((A + D)-(B +).
The focus error signal FE represented by C)) is obtained. The focus error signal FE is divided into a focus control signal in the land area and a focus control signal in the groove area and processed.
After that, the focus position of the focus lens 250 of the optical reproducing means 200 (direction perpendicular to the recording surface of the high-density recording medium 100) is controlled via the two-dimensional actuator control circuit 800.

That is, the focus error signal FE ((A + D)-(B
+ C)) is applied with the focus offset by the adder 314 and is output to the two-dimensional actuator control circuit 800. The groove / land offset setting on the D / A313 and D / A316 is analog switch SW3.
It is applied to the adder 314 through 17.

Incidentally, these D / A converters 313, 316
The microcomputer 400 provides offset values for focus control in the groove area and the land area, respectively. Further, the switching control signal output from the microcomputer 400, that is, the switching signal of the land (L) area / groove (G) area is input to the control input of the switch element 317.

The offset value added to the focus error signal FE via the D / A converters 313 and 316 is adopted in the present invention to control the focus position of the optical lens to the optimum position. It is a variable learned in the learning control, and when shipped as a product of the recording / reproducing apparatus of this optical information recording medium, it is initially set to a predetermined value and shipped. The initial setting value is recorded in the EPROM or the like which is the recording means of the microcomputer 400.

Further, the sum signal (A + B + C + D) from the adder circuit 305 is then subjected to a high frequency pass filter (HPF) 320 and a low frequency pass filter (LPF) 3.
21. Further, after passing through the envelope detection circuit 322, it is taken in by the sample hold (S / H) circuit 323 through the A / D conversion section of the microcomputer 400. This sample hold (S / H)
The timing taken by the circuit 323 is determined by a sample hold (S / H) timing signal output from the microcomputer 400, which will be described later.

Next, a focus control method in the recording / reproducing apparatus for the optical information recording medium of the present invention, the details of which have been described above, will be described with reference to the flowcharts of FIGS. 8 and 10. First, the flow chart shown in FIG. 8 is performed before the learning control shown in FIG. 10 is performed below, whereby the variable region of the focus position in the learning control is preset. Note that this flow is started, for example, at the same time when the reproducing device is turned on, is executed based on the various output signals shown in FIG. 1, and is executed for each of the land area and the groove area. .

In this flow, first, the focus error (FE) offset is set to an initial setting value (step S11). That is, the microcomputer 40
0 sets the initial setting values recorded in the EPROM or the like at the time of shipment in the D / A converters 313 and 316. After that, as shown in FIG. 9 attached, the microcomputer 400 performs a plurality of steps (for example, +8 steps to control) before and after the initial setting value (0) as a center with respect to the initial setting value of the offset. -16 steps up to -8 steps) are set, each step value is set as an offset value of the focus error (FE) to change the focus position, and the pit address area is set at the plurality of focus positions. Judgment of pit reproduction in. At this time, the determination condition of the pit address reproduction determining, by the ID signal shown in FIG. 7 (B), whether the ID signal in a range of one rotation of the track can be continuously recognized. Further, the number of sectors in which the ID signal can be recognized in one track may be used as the determination condition.

That is, in FIG. 8, first, the offset values 0 to -8 are sequentially set (step S12), and the pit P in the pit address area PA is also set depending on the respective focus positions. , P ... Is recognized to determine whether the address can be reproduced (step S13). As a result, if the pit address can be reproduced (“OK”), the offset value is stored (step S13). In S14), this is repeated until reproduction of the pit address becomes impossible (“NG”).
Then, in the same manner as above, the offset value is 0 to +8.
The steps are sequentially set (step S15), the reproduction is determined (step S16), the reproducible offset value is stored (step S17), and the reproduction is impossible (“NO”).
Is repeated until, finally, the offset value within the range that can be varied by learning, that is, the pit address recognizable offset value is set according to the step range (step S18), and the process ends.

As a result, it is possible to set the range in which the pits P, P ... Of the pit address area PA can be surely recognized in the step of -8 to +8 around the offset initial value (0) of the focus position control. become. Specifically, for example, in FIG. 9A, in the focus position control in the land area, the step is “NG” at −8 and +5, and therefore the area between them is −7 to. It can be seen that the pits P, P ... In the pit address area PA can be reliably recognized in the range of +4 steps. From this, in the focus position control in the land area, if the learning control is performed within the range of the steps from -7 to +4, the focus position can be controlled to a more optimal position while ensuring the reproduction of the pit address. It will be possible. The focus position control in the groove area is similar to the above, and in the example shown in FIG. 9B, the learning control can be performed later within the range of -4 to +7. I understand.

Next, learning control for controlling the optimum focus position of each of the land area and the groove area in which information is recorded will be described with reference to FIGS. When an unrecorded disc is inserted, the test zones assigned to the innermost and outermost discs and the laser drive circuit 500 are driven to perform recording. In this learning, since the relative change in the amplitude of the reproduced signal of the recorded data is detected,
For the recording pattern setting, a preset initial value is sufficient.

First, FIG. 10 shows a schematic processing flow of learning control for optimal focus position control. First, data is reproduced (step S21). At this time, as shown in FIG. 7A, a VFO portion in which pits of a predetermined width called 4T are recorded in a predetermined pattern (number), for example, is arranged at the head portion of each sector. After that, the data (DATA) section in which the record information to be reproduced is recorded continues. And there, especially in order to control the optimum focus position,
This is performed by utilizing the intensity of the reflected light in this VFO section. That is, in the VFO section, the reproduced signal waveform is as shown in FIG. 7C, however, however, the envelope detection circuit 32 that outputs the envelope waveform.
From 2 (see FIG. 1), if the output as shown in FIG. 7D, that is, the reflectance of the recording surface of the recording medium 100 is constant, its height (voltage) is always constant. The signal is being output. The reason why the 4T pattern is adopted is that the phase change medium is stable with respect to the fluctuation of the recording pattern and that the focus position of the optimum condition of recording and reproducing in the land-groove method is the 4T pattern. It is based on the fact that it is confirmed by experiments that the maximum amplitude of is obtained.

Therefore, as is clear from FIG. 1 above,
The microcomputer 400 outputs a sample hold (S / H) signal during the period of this VFO section to detect and reproduce the height of the envelope waveform (FIG. 7D) from the sample hold (S / H) circuit 323. Capture as signal amplitude value. In addition, sample hold (S / H) at this time
The signal and the amplitude of the detected reproduced signal (detected reproduced signal amplitude), which is the height of the envelope waveform captured by the signal, are shown in FIGS. 7 (E) and 7 (F).

Returning to FIG. 10 again, in the learning control for the optimum focus position control, the offset of the focus error (FE) is set next (step S2).
2). That is, here, the range is set by the pit address recognizable area obtained in step S18 in FIG. Specifically, for example, as shown in FIG. 9B, the possible setting area for the groove (G) area is -4 to +7, and this step value is set. .

Thereafter, as described above, based on the amplitudes of the detected reproduction signals fetched from a plurality of sectors, the offset value (step) of the focus error (FE) at which the signal amplitude in each sector becomes maximum (step The unit) is obtained (step S23). Then, the offset value of the focus error (FE) obtained for each sector is averaged by the following formula, and the optimum focus error (FE) offset for the land (L) area and the groove (G) area on the recording medium 100 is averaged. Value FEoff (L), FEof
You will get f (G).

[Equation 1]

In the above, the purpose of averaging
Is non-uniformity (so-called variation) in reflectance or the like in sector units in the circumferential direction of the disk which is the recording medium 100.
This is to eliminate the problem. That is, for example, as shown in FIG. 11, the amplitude of the detected reproduction signal in each sector (Sec.1 to Sec.17) (see FIG. 7F).
If they are different from each other, first, the optimum FE offset value is obtained in each sector (specifically, the FE offset values of the sectors that extend over the same circumference in the radial direction are averaged). After that, the FE offset values of each sector are averaged to obtain the optimum FE offset value FEof
f (L) and FEoff (G). This will be simplified and described with reference to the attached FIG.
c. 1-Sec. 3, the offset values at which the detected reproduction signal amplitude is maximum are -1, +1, +, respectively.
When 3 is obtained, these are averaged and +1 (step unit) becomes the optimum FE offset value. As a method for obtaining the focus offset value of the maximum amplitude value, a difference method, a maximum position calculation by a quadratic curve approximation calculation, and a left and right offset in which the amplitude value is reduced by -1 dB from the amplitude at which the maximum value is calculated There are methods such as obtaining from the half value of the position.

At this time, as is apparent from the above description, the optimum FE offset value obtained by the above control is set in the above step S22 (from -7 to
If the step range of +4) is exceeded, the closest value among the set values, that is, -7 or +4, is selected as the optimum FE offset value.
That is, this makes it possible to always control the focus position of the optical pickup to the optimum position while always accurately reading the address signal in the pit address area, and the loss of the address information impairs the operation of the entire reproducing apparatus. It is possible to always perform good focus control.

In the above description, so-called learning control has been described as an example of the method for controlling the optimum position of the focus, however, the present invention is not limited to such learning control. That is,
It is obvious that the present invention can be applied in the same manner as described above even when other control methods for performing the optimum focus position control are adopted.

Further, in the above description of the embodiment, the reproducing apparatus for reading the information recorded in advance on the optical information recording medium 100 and its operation have been described as the apparatus, however, the present invention is not limited thereto. The present invention is not limited to the above reproduction-only reproduction device, and can also be applied to a recording / reproduction device for an optical information recording medium having an information writing function. When the present invention is applied to a recording / reproducing apparatus for such an optical information recording medium, it is not limited to being used during the information reproduction, and also in the focus control during the information recording, the same as above. It is possible to apply. And, even in that case, since the address information on the recording surface of the optical information recording medium at the time of recording is surely obtained,
It will be apparent from the above description that a more optimal information recording operation can be obtained.

[0054]

As is apparent from the above detailed description, according to the recording / reproducing apparatus for an optical information recording medium and the focus control method thereof according to the present invention, a land area and a groove are formed on the information recording surface. In the area information reproduction and recording of a high density optical information recording medium such as a DVD, it is possible to optimally control the focus position of an optical pickup which is an optical reproducing means, and ensure good information reproduction or recording operation. At the same time, by ensuring that the address information of the pit address area between these areas, which is the basis of the operation of such a device, can be surely taken in, it is always possible to perform good reproduction or recording even under various conditions. It has an extremely excellent effect of enabling operation.

[Brief description of drawings]

FIG. 1 is a detailed diagram of a circuit configuration centering on a signal processing unit that processes a detection signal from a light receiving element of a recording / reproducing apparatus for an optical information recording medium according to an embodiment of the present invention.

FIG. 2 is a high-density recording medium D on which information is reproduced / recorded by the recording / reproducing apparatus for the optical information recording medium of the present invention.
It is a perspective view which shows the external appearance of VD.

3 is a cross-sectional view of a land area and a groove area of an information recording portion in the DVD shown in FIG.

FIG. 4 is an explanatory diagram showing a formation format of a land area and a groove area in a DVD which is the high density optical recording medium.

FIG. 5 is a partially enlarged perspective view showing a pit address area formed between a land area and a groove area in the DVD.

FIG. 6 is a block diagram showing the overall configuration of a recording / reproducing apparatus for an optical information recording medium of the present invention.

FIG. 7 is a waveform diagram showing a signal waveform of each part in the recording / reproducing apparatus for the optical information recording medium of the present invention.

FIG. 8 is a flowchart illustrating a focus control method in the recording / reproducing apparatus for the optical information recording medium of the present invention.

9 is an explanatory diagram for specifically explaining a pit address recognizable area set by the focus control method shown in FIG.

FIG. 10 is a flow chart diagram for explaining learning control of focus control in the recording / reproducing apparatus for the optical information recording medium of the present invention.

11 is an explanatory diagram for explaining an optimum FE offset value of each sector set by the learning control of FIG.

FIG. 12 is an explanatory diagram briefly explaining an optimum FE offset value set by averaging in the learning control of FIG.

[Explanation of symbols]

100 High Density Optical Recording Medium (DVD) L land area G groove area PA pit address area P pit 200 Optical reproduction means (optical pickup) 250 focus lens 300 signal processor 400 microcomputer 800 Two-dimensional actuator control circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Minemura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Stock Company Hitachi, Ltd. Video Information Media Division (72) Inventor Toshimitsu Gaku 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address Stock Company Hitachi, Ltd. Video Information Media Division (72) Inventor Kazuo Shigematsu 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Address Stock Company Hitachi Ltd. Video Information Media Division (72) Inventor Shinichi Arai Totsuka, Yokohama, Kanagawa Prefecture 292, Yoshida-cho, Tokyo Stock company Hitachi Ltd., Video Information Media Division (72) Inventor Koichiro Wakabayashi 1-280, Higashi Koikekubo, Kokubunji, Tokyo (56) References JP-A-3-165332 (56) JP, A) JP 8-329484 (JP, A) JP -231588 (JP, A) JP-A-7-287855 (JP, A) JP-A-9-128767 (JP, A) JP-A-3-273529 (JP, A) JP-A-6-68495 (JP, A) ) JP-A-4-49533 (JP, A) JP-A-9-293244 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B ^7/ 09-7/10

Claims (6)

(57) [Claims] 1. A track provided in a circular shape on a disk.
This is divided into sectors in the disk circumferential direction,
The information recorded on the recording surface of the optical information recording medium including the land area, the groove area, and the pit address area formed between the land area and the groove area is optically reproduced The focus position of the means is set and read in the land area and the groove area, respectively ,
Further, in the land area and the groove area,
Set the focus position of the optical playback means to the pit address
Offset range of the focus position that fits in the focus area
In a recording / reproducing apparatus for an optical information recording / reproducing medium, which is equipped with a control means for setting the inside of the enclosure,
Offset range of the focus position that fits in the focus area
The area that contains the address information that can be reproduced within one track.
A recording / reproducing apparatus for an optical information recording / reproducing medium, which is set based on the number of contacts . 2. A track provided on the disc in a circular shape.
And this is divided into sectors in the disk circumferential direction.
Land area, groove area, and land area in units
Address formed between the groove area and the groove area
Recorded on the recording surface of an optical information recording medium having an area and
Information, the focus position of the optical reproduction means
Set and read the area and groove area respectively.
In addition, the light in the land region and the groove region
The focus position of the hand-replay
Offset range of the focus position that fits in the area
The optical information recording / reproducing apparatus is provided with a control means set to
In the recording / playback device for raw media, the pit address
Offset range of the focus position that fits in the area
The address information can be reproduced continuously for two or more.
Optical information recording / reproducing medium characterized by being set as a condition
Body recording / playback device . 3. In claim 1 or claim 2,
The optical reconstruction in the land area and the groove area.
Set the focus position of the live source to the tip of the data part of the sector.
The amplitude of the reproduced signal of the VFO part located at the head becomes maximum.
Of the optical information recording / reproducing medium characterized by setting
Recording / playback device. 4. The focus position according to claim 3,
By the quadratic curve approximation calculation of the amplitude of the reproduction signal of the VFO section
Characterized by finding using maximum value detection Optical information recording
Recording / playback device for playback media. 5. The focus position according to claim 3,
From the amplitude obtained by obtaining the maximum value of the amplitude of the reproduction signal of the VFO section
Left and right focus offset with amplitude value reduced by -1db
Optical information recording characterized by being obtained from the half value of the dot position
Recording / playback device for playback media. 6. Claim 3, or Claim 4, or Claim
In item 5, it is applicable in the pit address area.
Within the focus position offset range
Of the optical reproduction means in the region and the groove region.
If no circus position exists, the pit address area
Nearest to the left and right of the focus position area
The focus offset value that touches the land area and
Focus of the optical reproducing means in the groove area
Of the optical information recording / reproducing medium characterized by setting the position
Recording / playback device.