JP2003178474A - Information recording / reproducing apparatus, information recording / reproducing method, and polarity reversal position detecting method of information recording medium - Google Patents

Abstract

(57) [Problem] To record on a disk of a land-groove type disk in which a land portion and a groove portion appear alternately and continuously by detecting the switching position of the land portion and the groove portion stably and reliably. To reproduce the information in a stable and reliable manner. When an optical head tries to reproduce information on a pit formation position on a disk, not an RF signal but an HPP signal is used to detect a position at which a land portion and a groove portion are switched.
Also, the positive and negative polarities of the pit signal appearing in the HPP signal are detected, the switching position of the land and the groove is detected based on the position where the order changes, and tracking control, focus control and the like of the optical head are performed by the respective components. In a manner suitable for

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing technique for an optically readable recording medium (hereinafter simply referred to as "disk"),
In particular, the present invention relates to an information recording / reproducing apparatus equipped with a control method of a light irradiating means corresponding to a disc of a format compatible with high density information recording and its function.

[0002]

2. Description of the Related Art In a disc, information is reproduced by focusing laser light on an information recording surface of the disc and detecting reflected light modulated by recording marks or pits.

Recording marks and the like are formed along a spiral guide groove formed on the information recording surface. In order to increase the recording density, it is necessary to increase the density in the thickness direction, circumferential direction or radial direction of the disk medium. Among them, it is possible to narrow the track pitch of the recording / reproducing track in order to increase the recording density in the radial direction, but there is a limit in forming the guide groove.

Therefore, as disclosed in Japanese Examined Patent Publication No. 4-4661, the width of the groove and the width between the grooves are made substantially the same, and the minimum crosstalk from adjacent tracks is determined by the laser light wavelength for irradiation of the groove depth. With such a depth, it becomes possible to form recording marks in the guide grooves (grooves) and between the guide grooves (lands) as well as to reproduce, thereby improving the recording density in the radial direction of the disc. .

In order to continuously reproduce the information recorded in the groove portion and the land portion, when the groove is simply formed continuously from the inner periphery to the outer periphery, the groove portion (land portion) is continuously formed. In the case of shifting from the state of being reproduced to the state of continuously reproducing the land portion (groove portion), the time required for the transition is required, and it is possible to continuously reproduce the information of the land portion and the groove portion continuously. It will be impossible.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. Hei 7-141701, the tracks of the land portion and the groove portion are approximately one.
By forming a groove (single spiral) that appears alternately every circumference, it is possible to continuously reproduce the recorded information recorded in the land portion and the groove portion.

In this disc, in order to specify the recording / reproducing position, the modulated position information is formed as a pit row instead of the guide groove on the track. At this time, it is difficult to form pit information for each track having a high density, and it is also difficult to reproduce and demodulate due to crosstalk from a pit string formed on an adjacent track.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 6-176404, a distance that is a quarter of the center position of each land portion and an adjacent land portion is offset to a position that is separated inward or outward. By being formed so as to be reproducible, both the land portion and the groove portion can be reproduced.

Further, as disclosed in Japanese Unexamined Patent Publication No. 8-221821, pits are pre-formatted at substantially equal intervals in the circumferential direction of the track, and the pits are adjacent to the land portion from the center position of the land portion or groove portion. A distance of ¼ of the distance between the central positions of the lands is alternately offset to positions spaced apart in the inner circumferential direction and the outer circumferential direction. On this disc, it is possible to form information such that the polarity reversal position can be relatively specified at the PID portion other than the pit formation position (PID portion) corresponding to the polarity reversal position.

In order to reproduce a recording mark formed on a disc having such a land portion or a groove portion, the condensing position of the laser beam focused on the information recording surface is set to the radius of the disc of the land portion or the groove portion. It is necessary to scan along the substantially central position with respect to the direction, and it is also necessary to ensure that the information recording surface is in focus. At this time, a deviation amount (tracking deviation amount) that is approximately proportional to the distance from the center position of the land portion or the groove portion of the laser beam focusing position
Is obtained by the tracking error signal (HPP signal) obtained by detecting the diffracted light of the laser light by the groove, and the focus position of the laser light is controlled using the deviation amount (tracking control). In the groove part, the polarity of the deviation amount is reversed.

FIG. 10 is a schematic view of the surface of the disk medium near the PID portion. The HPP signal waveform based on the tracking deviation amount generated when the light spot virtually crosses the radial direction 1003 of the disk medium is 30
4 shows. As is clear from this, the polarity of the HPP signal is different between the land portion and the groove portion. That is, when the HPP signal is negative in the groove portion, it is determined that the light spot is shifted to the right of the paper surface of FIG. 10, and the light spot is moved to the left of the paper surface to perform tracking, but in the land portion. , If the HPP signal is negative, it means that the HPP signal is shifted to the left on the paper surface.

Therefore, in order to continuously reproduce from the land portion to the groove portion or from the groove portion to the land portion,
At the position where the land portion and the groove portion are switched, it is necessary to control the focus position of the laser light corresponding to the polarity of the deviation amount being reversed. Then, JP-A-6-176404
As described in JP-A-8-221821 or JP-A-8-221821, areas are set on the track of the disk at substantially equal intervals in the circumferential direction, and pits are formed in the areas. By reproducing the information of the pits, the pits are formed so that the positions (polarity reversal positions) at which the land portions and the groove portions are switched can be recognized, and the states such as tracking control and focus control are switched based on the information.

[0013]

As described above, a pit is formed at an intermediate position between the land portion and the groove portion, and the pit information is formed using a signal (RF signal) based on the change in the total amount of reflected light. When the reading is performed and tracking control or focus control is performed to reproduce the signal, the signal amplitude cannot be large because the pits are formed offset from the track center. Therefore, it becomes difficult to detect the polarity reversal position, and it becomes difficult to perform tracking control, focus control, and the like, and it becomes extremely difficult to reproduce the recorded information.

In the detection of the polarity reversal position by reproducing the pit information, the polarity reversal position is recognized when the pit formation is defective, the disk shape is defective, or when it is difficult to reproduce the pit due to various control fluctuations. become unable.

Further, since the polarity reversal position is determined by the relative position with respect to other PID parts, if the plural PID parts are erroneously detected, the polarity reversal position cannot be predicted. Even when the number of rotations or the linear velocity of the disk medium fluctuates rapidly due to an access operation, the playback signal PL
L cannot follow, and it becomes impossible to demodulate and reproduce pit information.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide a method for reliably controlling the light irradiation means by stably detecting the PID position and the polarity reversal position, and an information recording / reproducing apparatus using the method.

[0017]

In order to solve the above problems, the present invention uses the HPP signal instead of the RF signal to detect the PID position and the polarity reversal position.

As shown in FIG. 10, a pit is equivalent to circumferentially short grooves lined up in the circumferential direction. Therefore, the light spot position follows the groove track center 1001 or the land track center 1002. If PI
Depending on the presence / absence of pits in the D area 301, the level at the boundary between the land portion and the groove portion and the state without the groove, that is, the no signal level are output.

That is, by using the HPP signal, the reproduction signal amplitude of the pit can be made sufficiently large, so that the information contained in the pit can be read. By reading this information, it is possible to detect the polarity reversal position at which the land portion and the groove portion are switched.

A signal obtained by reproducing the pit information is output on the HPP signal. At this time, according to the fact that the pit is formed inward or outward from the center of the land or groove, the HPP signal The polarity of the reproduction signal is determined according to the pit information output above. Since the order of offset in the inner or outer circumference is determined according to the land or groove, it is determined whether the light spot is currently scanning the land or groove according to the positive / negative order of the signal output corresponding to the pit. It becomes possible to do. When the result of the determination is changed from the land portion or the groove portion to the groove portion or the land portion, the polarity reversal position is detected.

Since the focus control and the tracking control suitable for the land portion and the groove portion can be performed by stably detecting the polarity reversal position in this way, the information recorded on the disc can be surely recorded over the entire disc. It can be recorded and played back.

[0022]

1 is a schematic block diagram of an embodiment of the present invention. The disk medium 101 is rotated by a spindle motor 102 at a substantially constant linear velocity. The optical head 103 includes a semiconductor laser, an optical component for focusing light on the information recording surface of the disk, a detector for detecting reflected light, an actuator for varying the light focusing position, and the like.

From the optical head, a signal corresponding to the RF signal and the HPP signal is changed as a voltage value by a gain controller (GCA).
It is output to 112 and 115, respectively. A constant gain is set in GCA, and AGC (automatic gain control unit) 11
3 and 116, respectively. The AGC outputs so that the output becomes substantially constant, and then outputs to the switch 117.
The switch 117 is switched depending on the PID portion and the data area on the disc, and outputs the HPP signal of the PID portion and the RF signal in the data area to the DC corrector 118, respectively.

After that, when the switch 117 selects the HPP signal, the DC corrector 118 determines that the 2 in the HPP signal.
Suppresses DC fluctuation components of types of PID information and RF signals,
Output to the waveform equalizer (EQ) 119. The EQ compensates for the high frequency component lowered in the optical system or the like. The output of EQ is AS
A C (automatic slice level controller) 120 binarizes the signal component at a slice level at which the duty ratio becomes approximately 50%, and outputs the binarized signal to the PLL 121 and the discriminator 122.

In the PLL, a substantially constant reproduction clock that follows the edge interval of the input signal is generated, and the discriminator discriminates the output of the ASC into two values at the timing of the edge of the reproduction clock and outputs it as a signal string. . The signal train is demodulated in the demodulator 123 according to a predetermined modulation rule, for example, from a 16-pit signal train to 8-pit data, and the data in the recording area is error-corrected by the ECC 124. The polarity reversal position detector 1 (130) detects that the polarity of tracking, focus, etc. of the data signal sequence of the PID section is switched before and after the PID section based on prerecorded PID information.

The polarity reversal position detector 1 and the PID error detector operate in synchronization with the reproduction clock generated by the PLL 121. The detected PID position, the position of the PID to be reproduced next from the demodulated contents, and the It is possible to predict the content. Therefore, the control signal can be output to the controller 132 without delay, and even if the information in the PID area at one location cannot be reproduced, the control signal can be generated from the previous pit information.

The signal sequence from the demodulator is input to the PID error detector 126 to detect the presence or absence of an error in the PID information, and when the reproduced PID information contains an error,
The PID information is estimated from the information of the immediately preceding PID, and a control signal is output to the controller 132.

However, if the PID error continues a plurality of times (some times can be set appropriately), the polarity reversal position cannot be detected from the PID information, which makes tracking control and focus control difficult. Therefore, by switching the switch 131, the polarity reversal position detector 2 (12
The output of 9) is selected to be output to the controller 132.
In other cases, the polarity reversal position detector 1 has many advantages such as not affecting tracking control and focus control and predicting the position and content of the PID to be reproduced next from the demodulated content. Output to the controller.

The signal of the AGC 116 is also output to the PID position detector 127, and the PID position detector outputs a control signal to the switch 117 and the polarity discriminator 128. To the switch 117, a PID position detection signal for discriminating the PID portion and the recording area is output. Switch 117
Operates so that when the PID position detection signal indicates the PID portion, the HPP signal having a large signal amplitude of the pit reproduction signal is selected, and when it indicates the recording area, the RF signal is selected. This makes it possible to reliably read the information contained in the pits of a disc formed by shifting the pits to which the present invention is applied from the center of the track.

To the polarity discriminator, two P's in the PID section are connected.
The signal detection position output in the positive (plus) polarity or the negative (minus) polarity on the HPP signal corresponding to the ID is output to the polarity discriminator 128. The polarity discriminator uses the PI
It is determined whether the light spot is a land portion or a groove portion of the track being scanned based on the detection signals of the positive and negative signals in the D portion.

The polarity reversal position detector 2 (129) uses the output of the polarity discriminator to detect the PID position where the polarity of the track changes from groove to land or from land to groove. Output to the switch 131.

As described above, the switch 131 is
When the ID part cannot be detected (a defect in the PID part, a reproduction error due to a change in the inclination of the disk medium, a PLL error due to a rotation change, etc.), the polarity reversal position information is sent to the controller 132.
Otherwise, the polarity inversion information of the polarity inversion position detector 1 is output to the controller 132.

The output of the AGC 116 of the HPP signal is input to the controller 132 as a deviation amount from the track center. It is output to the tracking actuator in the optical head so that the focal position follows the track center. At this time, the polarity of the output of the control amount is switched by the land portion or the groove portion based on the polarity reversal position information.

Further, although not shown in the figure, in reproducing the land portion or the groove portion, the focus offset in the control of the focusing of the light spot (focus control) corresponds to each of the land portion and the groove portion. Are switching.

FIG. 2 shows a disk medium 101 used in the present invention.
The schematic diagram of is shown. Tracks are spirally formed from the inner circumference to the outer circumference on the information recording surface of the disk medium.
Tracks are groove track 201 and land track 2
02 switches at the polarity reversal position 203 once per revolution.

Although not shown in the drawing, 17 to 40 PIDs are formed per track on the track at a substantially constant interval in the circumferential direction. Information as to whether or not the position is the polarity reversal position is uniquely recorded as a pit.

FIG. 3 shows a schematic diagram of tracks and PIDs on the disk and an HPP signal waveform when an optical spot scans one of the tracks. The shape of the track at positions other than the polarity reversal position 203 is shown in FIG. Groove tracks 201 and land tracks 202 are alternately formed in the radial direction. In the circumferential direction, the PID area 301
And recording areas 302 are formed alternately, and the intervals between the PID areas are substantially constant.

In the PID portion, pits are formed with a distance of 1/4 of the groove track interval in the inner peripheral direction and the outer peripheral direction with respect to the center of the groove track.
The contents recorded in the two PIDs are the same. 30 light spots on land track at 304
3 shows an HPP signal waveform when scanning is performed as shown in FIG. PI
At D, a signal corresponding to the pit information is output with a positive level and a negative level with respect to the level in the HPP recording area. Reference numeral 314 shows an HPP signal waveform when the groove track is scanned. The order of outputting positive and negative pit signals is opposite to that in the case of reproducing the land track.

Reference numeral 324 in FIG. 3 (b) shows an HPP signal waveform when passing through the polarity inversion position 203 and shifting from the groove track to the land track. The light spot locus in that case is shown at 323. It can be seen that the output waveform of the pit signal of the PID portion at the polarity reversal position and the waveform of the PID portion immediately before that are reversed in order.

Therefore, it is possible to detect the polarity reversal position by using the reversal of this signal, and the polarity of the tracking control and the offset of the focusing control can be switched with that.

FIG. 4 is a schematic diagram showing the HPP signal output and RF signal output when the land track is reproduced, the output of the switch 117, the output of the DC correction 118 and the output of the EQ 119. The pit information of the PID portion of the HPP signal and the recording mark information of the recording area on the RF signal are combined by the switch 117, the DC compensator 118 suppresses the fluctuation of the DC voltage, and the EQ 119 suppresses the signal deterioration of the high frequency band. Compensate and suppress low-frequency fluctuations. This signal output is AS
By binarizing with C120, it is possible to reproduce the pit information and the recording mark information in the same manner.

FIG. 5 shows a PID position detector 1 according to the present invention.
27 shows a signal waveform of one example of No. 27. An example of the circuit configuration at this time is shown in FIG. HP when playing a land track
The peak detector 601 and the bottom detector 602 are used to perform envelope detection on the P signal output waveform. The output of the detector is compared with the peak slice level 614 and the bottom slice level 616 in comparators 604 and 606, respectively, and the results are output to ANDs 607 and 608, respectively. Further, the outputs of the respective envelope detections are subtracted by a subtractor 603, and a difference signal slice level 615 is calculated in a comparator 605.
Compared to. The output of the comparator 605 is output as a PID detection signal and is also used as a mask signal in the logical products 607 and 608. The outputs of the logical products 607 and 608 are output as detection signals of the positive side and negative side outputs of the pit signal of the PID portion, respectively.

During the period when the PID detection signal is output,
By detecting the output order of the positive-side and negative-side pit detection signals, the polarity discriminator 128 can determine whether the track is a land track or a groove track.

FIG. 7 shows a PID position detector 1 according to the present invention.
27 shows a signal waveform of another example of No. 27. Further, FIG. 8 shows a circuit configuration example at this time. With respect to the HPP signal output waveform when the land track is reproduced, the high frequency breaker 801 is used to suppress the high frequency component corresponding to the pit information. The outputs of the high frequency circuit breakers are comparators 802 and 80, respectively.
3 is compared with the upper slice level 812 and the lower slice level 813, respectively, and the result is expanded in pulse width correctors 804 and 805, respectively. The outputs of the respective pulse width correctors are logically ORed in the logical OR 806 and output as a PID detection signal.

FIG. 9 shows a schematic block diagram of another embodiment of the present invention. In this embodiment, the PID is detected not only from the pit information, but only by using the PID position detector of the present invention, and the polarity and the polarity inversion position are detected by using only the output of the PID position detector 127. There is. With such a configuration, even if the two polarity inversion position detectors, the polarity inversion position detector 1 and the polarity inversion position detector 2 as described above, are not used, the pit information is not lost. The polarity reversal position can be detected regardless of this. In this embodiment, the PID position detector 127 may be either the first or second embodiment.

Note that the switch 117 is provided in this embodiment for reading information such as the ID number contained in the pit, and when only the information of the polarity reversal position is recorded in the pit. Since the polarity reversal position detector 2 can detect the polarity reversal position, the switch 1
It is not always necessary to provide 17.

[0047]

According to the present invention, the HPP signal is used to reproduce the information recorded in the pits of the PID part in the disc capable of continuous recording and reproducing in both the land part and the groove part. Since this is reproduced, a signal having a sufficiently large signal amplitude is reproduced, and the information can be surely reproduced.

Further, the switching portion between the land portion and the groove portion can be detected stably and easily from the positive / negative order of the HPP signal waveform without demodulating and reproducing the information recorded in the pits of the PID portion. Thus, it is possible to realize a recording / reproducing apparatus that enables stable and reliable recording and reproduction.

[Brief description of drawings]

FIG. 1 is a block diagram of a reproduction processing system of an information recording / reproducing apparatus using the present invention.

FIG. 2 is a schematic view of a disk medium of the present invention and a conventional disk medium.

FIG. 3 is an example of a track configuration on a disk of the present invention and an output of a track deviation signal.

FIG. 4 is a diagram showing a reproduction signal of a reproduction processing system of the present invention.

FIG. 5 is a signal output example of the PID position detector according to the first embodiment of the present invention.

FIG. 6 is a block diagram of a PID position detector according to the first embodiment of the present invention.

FIG. 7 is a signal output example of the PID position detector according to the second embodiment of the present invention.

FIG. 8 is a block diagram of a PID position detector according to a second embodiment of the present invention.

FIG. 9 is a block diagram of a reproduction processing system of an information recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 10 is a schematic view of a disc used in the present invention.

[Explanation of Codes] 101 ... Disk, 102 ... Spindle Motor, 103
... optical head 117 ... switch, 131 ... switch, 6
03 ... Subtractor, 604 ... Comparator, 605 ... Comparator, 60
6 ... Comparator, 802 ... Comparator, 803 ... Comparator.

Continued front page    (72) Inventor Toru Kawashima             Stock, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Hitachi Image Information System Co., Ltd. (72) Inventor Kuki Sugiyama             Stock, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Company Hitachi, Ltd. Visual Information Media Division (72) Inventor Hiroyuki Minemura             Stock, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Company Hitachi, Ltd. Visual Information Media Division (72) Inventor Yoshio Suzuki             Stock, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Company Hitachi, Ltd. Visual Information Media Division (72) Inventor Hisamitsu Tanaka             Stock, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Company Hitachi, Ltd. Visual Information Media Division F-term (reference) 5D090 AA01 BB03 BB04 CC01 CC04                       CC16 DD03 EE15 FF02 FF15                       GG02 GG22 LL08                 5D118 AA13 BA04 BB02 BC09 BC13                       BF02 BF03 CA13 CC15 CD03                       CG02

Claims (30)

[Claims] 1. A light irradiated onto an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the track center. In an information recording / reproducing apparatus for recording / reproducing information by detecting the return light of, and processing a signal based on the return light, a polarity reversal position at which the land portion and the groove portion are switched using a tracking error signal. An information recording / reproducing apparatus comprising a polarity reversal position detecting means for detecting 2. The information recording / reproducing apparatus according to claim 1, wherein the polarity reversal position detecting means detects the polarity reversal position by detecting a change in the waveform of the tracking error signal. 3. The information recording / reproducing apparatus according to claim 1, wherein the polarity reversal position detecting means detects the polarity reversal position by detecting a positive / negative change in the waveform of the tracking error signal. . 4. The information recording / reproducing apparatus according to claim 3, wherein the polarity inversion position is detected by performing envelope detection of the tracking error signal. 5. The information recording / reproducing apparatus according to claim 3, wherein the polarity reversal position is detected by cutting off a signal component of the tracking error signal in a high frequency range. 6. The information recording / reproducing apparatus according to claim 1, wherein the polarity reversal position detecting means detects the polarity reversal position by reading information included in the tracking error signal. 7. A light irradiating means for an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the track center. In the information recording / reproducing apparatus that detects the return light of the light emitted by the device and reproduces information by the signal processing unit processing the information signal based on the return light, the position where the light irradiation unit is formed with the pits. A selection means for selecting a tracking error signal when irradiating light on the light source, and selecting the information signal for outputting to the signal processing means when irradiating light on the land portion or the groove portion. An information recording / reproducing apparatus characterized by: 8. A formation position detection means for detecting a formation position of the pit by detecting a change in the tracking error signal is provided, and the selection means outputs the information signal and the tracking error by the output of the formation position detection means. 8. The information recording / reproducing apparatus according to claim 7, wherein the signal is selected. 9. The information according to claim 7, wherein a polarity reversal position at which the land portion and the groove portion are switched is detected by the signal processing unit reproducing the tracking error signal. Recording / playback device. 10. A light irradiating means for an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the center of the track. In the information recording / reproducing apparatus, which detects the return light of the light emitted by the device and reproduces information by processing the information signal based on the return light by the signal processing means, the land portion based on the information included in the tracking error signal. And a second polarity inversion position for detecting the polarity inversion position by detecting a change in the waveform of the tracking error signal. An information recording / reproducing apparatus comprising: a detecting unit. 11. A tracking control means for controlling tracking of the light irradiating means and a focus control means for controlling focus of the light irradiating means are based on the output of the first or second polarity reversal position detecting means. 11. The information recording / reproducing apparatus according to claim 10, wherein tracking control or focus control corresponding to a portion or the groove portion is performed. 12. The output of the second polarity reversal position detection means is output to the tracking control means and the focus control means when the information contained in the tracking error signal cannot be read a plurality of times. The information recording / reproducing apparatus according to claim 10. 13. A light irradiating means for an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the track center. In the information recording / reproducing apparatus that detects the return light of the light emitted by the device and reproduces the information by processing the information signal based on the return light by the signal processing means, the formation position of the pit is detected from the change of the tracking error signal. Forming position detecting means, and the output of the forming position detecting means selects the tracking error signal when the light irradiating means is irradiating light to the position where the pit is formed, and the land portion or the First selecting means for selecting the information signal and outputting it to the signal processing means when the groove portion is irradiated with light; First polarity reversal position detection means for detecting a polarity reversal position at which the land portion and the groove portion switch based on information included in the tracking error signal processed by the processing means, and a change in the waveform of the tracking error signal. Second polarity reversal position detection means for detecting the polarity reversal position by detecting the second polarity reversal position, and second polarity reversal position detection if the signal processing means cannot read the information contained in the tracking error signal a plurality of times. Tracking control means and second selection means for outputting the output of the means to the focus control means, and the tracking control means for controlling the tracking of the light irradiation means and the focus control means for controlling the focus of the light irradiation means are The track corresponding to the land portion or the groove portion based on the output of the second selecting means. King control or information recording and reproducing apparatus and performs focus control. 14. The information recording / reproducing according to claim 13, wherein the second polarity reversal position detecting means detects the polarity reversal position by detecting a positive or negative change in the waveform of the tracking error signal. apparatus. 15. The information recording / reproducing apparatus according to claim 14, wherein the second polarity reversal position detecting means detects the polarity reversal position by performing envelope detection of the tracking error signal. 16. The polarity reversal position detecting means detects the polarity reversal position by cutting off a signal component of the tracking error signal in a high frequency range.
4. The information recording / reproducing apparatus described in 4. 17. A light irradiating means for an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the center of the track. Irradiates light, the light detection means detects the return light of the irradiation light, generates a signal based on the return light, and the signal processing means processes the signal to control the tracking of the light irradiation means. An information recording / reproducing apparatus for reproducing information while the signal processing means processes a tracking error signal to generate a signal indicating the land portion and the groove portion, and based on the signal, the land portion and An information recording / reproducing apparatus, wherein tracking control of the light irradiation means is performed in the groove portion. 18. The tracking error signal is a signal obtained by detecting diffracted light of a groove formed by forming the land portion, the groove portion and the pit. Any one of 17
The information recording / reproducing apparatus described in 1. 19. A land portion of an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the center of the track. And a polarity reversal position detection method for an information recording medium for detecting a position at which the groove part and the groove part are switched, wherein a polarity reversal position at which the land part and the groove part are switched is detected using a tracking error signal. A method for detecting the polarity reversal position of a characteristic information recording medium. 20. The polarity reversal position detecting method for an information recording medium according to claim 19, wherein the polarity reversal position is detected by detecting a change in the waveform of the tracking error signal. 21. The polarity reversal position detecting method for an information recording medium according to claim 19, wherein the polarity reversal position is detected by detecting a positive or negative change in the waveform of the tracking error signal. 22. The method of detecting the polarity reversal position of an information recording medium according to claim 21, wherein the polarity reversal position is detected by performing envelope detection of the tracking error signal. 23. The polarity reversal position detecting method for an information recording medium according to claim 21, wherein the polarity reversal position is detected by cutting off a high frequency component of the tracking error signal. 24. The method for detecting the polarity reversal position of an information recording medium according to claim 19, wherein the polarity reversal position is detected by reading information included in the tracking error signal. 25. Light radiated on an information recording medium in which a land portion and a groove portion are alternately formed on a track, and a pit having information indicating at least the land portion or the groove portion is provided offset from the track center. Is an information recording / reproducing method for reproducing information by detecting a signal based on the return light, wherein the land portion and the groove portion are switched based on information included in a tracking error signal. A first polarity reversal position detection signal indicating a position is generated, and a change in the waveform of the tracking error signal is detected to generate a second polarity reversal position detection signal indicating the polarity reversal position. The tracking control and the focus control suitable for the land portion or the groove portion are performed based on the second polarity inversion position detection signal to illuminate the light. Information recording and reproducing method characterized by. 26. When the information included in the tracking error signal cannot be read a plurality of times, tracking control and focus control suitable for the land portion or the groove portion are performed based on the second polarity inversion position detection signal. 26. The information recording / reproducing method according to claim 25, characterized in that the information is reproduced by irradiating light. 27. The information recording / reproducing method according to claim 25, wherein the second polarity inversion position detection signal is generated by detecting a positive or negative change in the waveform of the tracking error signal. 28. The information recording / reproducing method according to claim 27, wherein the second polarity inversion position detection signal is generated by envelope detection of the tracking error signal. 29. The information recording / reproducing method according to claim 27, wherein the second polarity inversion position detection signal is generated by cutting off a signal component of the tracking error signal in a high frequency range. 30. The tracking error signal is a signal obtained by detecting diffracted light of a groove formed by forming the land portion, the groove portion and the pit. 29. The information recording / reproducing method described in any one of 29.