JP2006190422A - Optical recording medium, position detecting method of multi-beam, adjusting method of optical pickup, optical pickup apparatus, optical recording and reproducing apparatus and optical recording and reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording medium and a position detecting method of a multi-beam capable of detecting positions and an interval on a recording track of beam spots disposed on the optical recording medium when optical recording and reproduction are performed by near field irradiation with two or more laser beams and to provide an adjusting method of an optical pickup, an optical pickup apparatus, an optical recording and reproducing apparatus and an optical recording and reproducing method utilizing the same. <P>SOLUTION: In the optical recording medium 1 wherein near field optical recording and/or reproduction is performed by using at least two laser beams, at least one pit row region 30P wherein pit rows 35A and 35B are disposed in positions deviated from recording track centers C1 and C2 is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical recording medium that performs recording and / or reproduction by irradiating two or more laser beams in the near field and an optical recording medium suitable for application to an optical recording / reproducing apparatus using the same, a multi-beam position detection method, The present invention relates to an optical pickup adjustment method, an optical pickup device, an optical recording / reproducing apparatus, and an optical recording / reproducing method.

  Optical (or magneto-optical) recording media represented by compact disc (CD), mini disc (MD), and digital video disc (DVD) are widely used as storage media for music information, video information, data, programs, and the like. Yes. However, with higher sound quality, higher image quality, longer time, and larger capacity of music information, video information, data, programs, etc., an even larger capacity optical recording medium and an optical recording / reproducing apparatus that performs recording / reproduction Is desired.

Therefore, in order to cope with these, in the optical recording / reproducing apparatus, the light source, for example, the semiconductor laser has a shorter wavelength and the numerical aperture of the condensing lens is increased, and the light spot that converges through the condensing lens is reduced. The diameter has been reduced.
For example, with regard to semiconductor lasers, GaN semiconductor lasers whose oscillation wavelength has been shortened from the 635 nm to 400 nm bands of conventional red lasers have been put into practical use, and thereby the diameter of the light spot is being reduced. For example, for further shortening of the wavelength, a far ultraviolet solid-state laser UW-1010 that continuously oscillates light having a single wavelength of 266 nm manufactured by Sony Corporation has been put on the market. It is being planned. In addition to this, research and development of a Nd: YAG laser double wave laser (266 nm band), a diamond laser (235 nm band), a GaN laser double wave laser (202 nm band), and the like are underway.

Further, for example, by using an optical lens having a large numerical aperture represented by a solid immersion lens, for example, a condensing lens having a numerical aperture of 1 or more is realized, and the objective surface of the condensing lens is used as an optical recording medium. A so-called near-field optical recording / reproducing system in which recording / reproducing is performed close to about one-tenth of the light source wavelength has been studied.
In increasing the transfer rate of this near-field optical recording / reproducing method, it is important how to rotate the disc at high speed while maintaining the optical contact state between the optical recording medium and the condenser lens.

For example, when a solid immersion lens is used, a solid immersion lens and an objective optical lens are arranged in this order from the optical recording medium side to constitute a near-field light condenser lens.
Here, when the solid immersion lens is formed in a super hemispherical shape, assuming that the radius of curvature of the hemispherical part is r, the refractive index is n, and the thickness along the optical axis is t, t = r (1 + 1 / n) There is a relationship. For example, when the solid immersion lens is formed in a hemispherical shape, if the radius of curvature of the hemispherical part is r, the refractive index is n, and the thickness in the direction along the optical axis is t, there is a relationship of t = r.

The condensing lens having such a configuration is mounted on a biaxial pickup device used for optical recording / reproducing or a magnetic head device used for magnetic recording / reproducing, and optically determines the distance between the optical recording medium and the condensing lens. Keep in good contact.
At this time, the objective surface of the solid immersion lens is opposed to the surface of the optical recording medium at a distance of about one tenth of the wavelength of the light to be used as described above, and the object surface of the optical recording medium rotating at high speed is used. In order to prevent damage such as scratches and wear on both the lens and the medium due to contact, it is necessary to precisely control and hold the distance between the lens and the optical recording medium and the relative angle thereof (see, for example, Patent Document 1). .

  For this reason, it is difficult to increase the rotational speed of the optical recording medium in order to increase the transfer rate. That is, in the near-field optical recording / reproducing method, the positional accuracy between the condensing lens and the optical recording medium increases as the distance between the solid immersion lens and the optical recording medium and the relative angle increases as the optical recording medium rotates at a higher speed. Since accuracy is required and this accuracy is required to be maintained even when the environment changes, it is extremely difficult to realize a near-field optical pickup device and a near-field optical recording / reproducing device compatible with a high transfer rate. .

In order to realize an optical recording medium having a high recording density of about 100 Gbit / inch ² corresponding to such a near-field optical recording / reproducing system, the recording track width needs to be about 100 nm or less. Manufacturing by beam exposure is possible, but further narrowing is difficult, and it is also difficult to increase the information density in the track direction.

  On the other hand, a method has been proposed in which the signal transfer rate is improved by simultaneously reproducing two tracks without changing the recording density (see, for example, Patent Document 2).

JP 2004-53303 A JP 2003-272176 A

In the method described in Patent Document 1, a beam different from the recording / reproducing beam is used as a laser beam for detecting a gap (gap) between the solid immersion lens and the optical recording medium. Not considered.
Further, in the optical recording medium described in Patent Document 2, a method of performing recording and reproduction by irradiating two beam spots on recording tracks existing on both sides across one tracking track (guide groove), Information transfer rates are being increased.
However, in the technique disclosed in Patent Document 2, when the near-field light is specifically irradiated onto the optical recording medium, for example, the distance (gap) between the solid immersion lens as the near-field light irradiation means and the optical recording medium, 2 Since how to adjust the irradiation position of the beam to the center of the recording track is not considered, once the optical pickup device is assembled, it is impossible to adjust the position of the beam spot on the recording track. May affect playback characteristics.

  It is an object of the present invention to detect the position and interval of a beam spot arranged on an optical recording medium on a recording track when performing optical recording / reproducing by near-field irradiation using two or more laser beams. Provided is an optical recording medium, a multi-beam position detection method, an optical pickup adjustment method, and an optical pickup device using the optical recording medium. The optical recording medium can be used for high density and large capacity, particularly high transfer rate, and recording. An object of the present invention is to provide an optical recording / reproducing apparatus and an optical recording / reproducing method that enable near-field optical recording / reproducing with good reproducing characteristics.

In order to solve the above-described problems, an optical recording medium according to the present invention is an optical recording medium that is recorded and / or reproduced by near-field optical beams using two or more laser beams, and a pit row is disposed at a position shifted from the recording track center. It is characterized in that at least one pit row area is provided.
The present invention is also characterized in that the above-mentioned optical recording medium is provided with a pit row arranged at a position shifted from the center of the recording track for each of the two or more laser beams.

The present invention is also a multi-beam control method for near-field irradiation of two or more laser beams onto an optical recording medium, wherein at least one or more pit rows provided at positions shifted from the recording track center of the recording medium. , The irradiation position shift from the recording track center at the irradiation position of the multi-beam is detected, and the irradiation position of the multi-beam is adjusted based on the detected amount.
The present invention is also a method for adjusting an optical pickup that irradiates an optical recording medium with two or more laser beams in the near-field, and includes at least one or more pits arranged at positions shifted from the recording track center of the optical recording medium. By reproducing the row, an irradiation position shift of at least one of the two or more laser beams from the recording track center is detected, and the irradiation position of the laser beam is adjusted based on the detected amount. And

Furthermore, the present invention is an optical pickup device that irradiates an optical recording medium with two or more laser beams in a near field, and includes at least one pit row arranged at a position shifted from the recording track center of the optical recording medium. Detection is performed, and the irradiation position deviation of at least one of the two or more laser beams from the recording track is adjusted.
The present invention is also an optical recording / reproducing apparatus having an optical pickup device that irradiates two or more laser beams onto the optical recording medium in a near-field, and is at least arranged at a position shifted from the recording track center of the optical recording medium. Light receiving means for detecting one or more pit rows, signal comparing means for comparing a reproduction signal detected from the light receiving means, and recording of at least one of the two or more laser beams based on the compared signal It comprises at least beam position detecting means for detecting an irradiation position deviation from a track and an adjusting means for adjusting the position of the at least one beam based on the irradiation position deviation amount.
The optical recording / reproducing method according to the present invention is an optical recording / reproducing method for recording and / or reproducing by irradiating two or more laser beams onto the optical recording medium in the near field, and deviating from the recording track center of the optical recording medium. At least one or more pit rows arranged at the predetermined position are reproduced to detect an irradiation position deviation of at least one of the two or more laser beams from the recording track. Recording and / or reproduction is performed by adjusting the irradiation position of the beam described above.

  As described above, in the present invention, when performing near-field optical recording and / or reproduction using two or more laser beams, a pit row is arranged on the optical recording medium at a position shifted from the recording track center. Is detected. As will be described in detail in the example of the subsequent embodiment, when a pit row that is intentionally arranged at a position deviated from the recording center is reproduced as described above, the beam spot corresponds to the amount of deviation from the recording track center, The reproduction signal amplitude changes. Therefore, by using this, it is possible to detect the amount of deviation of the beam spot from the center of the recording track and further to which side. Therefore, on the basis of the positional deviation detected from the change in the reproduction signal amplitude, for example, by providing a mechanism for rotating the optical pickup along the surface of the optical recording medium from the recording track extension direction (so-called tangential direction). By controlling the irradiation position, it is possible to correct the deviation of each beam spot irradiation position from the recording track center.

  That is, according to the present invention, since a plurality of recording / reproducing beam spots are used, the recording / reproducing signal which has been a limit in the conventional near-field optical recording / reproducing method without high rotation of the optical recording medium. In the direction perpendicular to the extending direction of the recording track from the center of the recording track, that is, in the case where the optical recording medium is a disc type, the deviation in the radial direction can be adjusted well. Thus, it is possible to avoid or reduce the deterioration of the recording / reproducing characteristics due to the beam spot displacement.

As described above, according to the optical recording medium of the present invention, when near-field optical recording / reproducing is performed on the optical recording medium using two or more laser beams, the recording track of the optical recording medium of the laser beam is used. The positional deviation from the center can be adjusted.
Further, in the optical recording medium of the present invention, by providing a pit row arranged at a position shifted from the center of the recording track for every two or more laser beams, it is possible to adjust the position shift of all the laser beams.
Further, in the optical recording medium of the present invention, since the frequency of the pit row provided for every two or more laser beams is different, the positional deviation of each laser beam can be detected for each frequency, so the positional deviation is detected with higher accuracy. be able to.
Further, in the optical recording medium of the present invention, by setting the amount shifted from the recording track center of the pit row to 2 or more, it is possible to detect the positional deviation of each laser beam more reliably.

Furthermore, according to the multi-beam control method of the present invention, it is possible to detect and adjust the positional deviation of the laser beam from the recording track center.
Further, in the multi-beam control method of the present invention, the position shift of all laser beams can be adjusted by providing a pit row arranged at a position shifted from the center of the recording track for every two or more laser beams. .
Furthermore, in the multi-beam control method of the present invention, since the frequency of the pit row provided for each of two or more laser beams is different, the positional deviation of each laser beam can be detected for each frequency, so that the positional deviation is detected with higher accuracy. can do.

Further, according to the adjustment method, the optical pickup device, the optical recording / reproducing apparatus, and the optical recording / reproducing method of the present invention, it is possible to adjust the positional deviation of two or more laser beams from the recording track center.
Furthermore, in the optical pickup adjustment method, optical pickup apparatus, and optical recording / reproducing apparatus of the present invention, the pickup section of the optical system that irradiates the multi-beam is placed on the surface of the optical recording medium from the extending direction of the recording track of the optical recording medium. By rotating along, the control of moving the irradiation position of the laser beam to the recording track center is performed, so that the multi-beam can be irradiated to the recording track center with a relatively simple mechanism with high accuracy.

Examples of the best mode for carrying out the present invention will be described below, but the present invention is not limited to the following examples.
First, an example of an optical recording medium according to the present invention will be described with reference to the schematic configuration diagrams of FIGS. 1A and 1B.
The optical recording medium of the present invention is an optical recording medium that is recorded and / or reproduced by near-field optical recording using two or more laser beams, and is sandwiched between guide tracks 31 as shown in FIG. In the recorded track, a pit row, in this case the first and second pits, is shifted from the center of the recording track indicated by the alternate long and short dashed lines C1 and C2, that is, in a position shifted in a direction perpendicular to the extending direction of the recording track. Rows 35A and 35B are arranged. In the example shown in the figure, an example is shown in which recording and / or reproduction is performed by irradiating a recording track region sandwiched between two guide beams 31 with a near field.
In this case, in the recording tracks 30A and 30B to which each laser beam is irradiated in the near field, the first pit row 35A is guided to the recording track center C1, and the second pit row 35B is guided to the recording track center C2. It is provided on the opposite side of the track 31, that is, at a position shifted to the boundary line side of the recording track indicated by a two-dot chain line B.
As shown in FIG. 1B, for example, in the case of a disc-shaped optical recording medium 1, such pit rows 35A and 35B have at least one pit row region 30P intermittently or partially between recording / reproducing regions 30R. Two or more are formed in the pit row region 30P.

  Further, the arrangement positions of these pit rows with respect to the recording track center may be shifted in different directions as shown in FIG. 1, or may be shifted in the same direction. Similarly, the deviation from the center of the recording track may be the same or different for each beam.

Next, as an example of the multi-beam detection method of the present invention for detecting an irradiation position shift of two or more laser beams on a recording track using such an optical recording medium, a case where two laser beams are used as an example. explain. As the irradiation positions of the first and second laser beams, there are six possible positions as shown in the schematic plan views of FIGS. That is, as shown in FIG. 6A, when the first beam spot 32A is substantially located on the recording track center indicated by the one-dot chain line C1 of the recording track 30A, as shown in FIG. 2B, the first beam spot 32A is shifted to the guide track 31 side. In this case, as shown in FIG. 2C, the recording track 30B may be shifted to the adjacent recording track 30B. Further, as shown in FIG. 6D, when the second beam spot 32B is located substantially on the recording track center indicated by the one-dot chain line C2 of the recording track 30B, as shown in FIG. 2E, the second beam spot 32B is shifted to the guide track 32 side. In this case, as shown in FIG. 2F, the recording track 30A may be shifted to the adjacent recording track 30A.
Therefore, when two beam spots are irradiated in this way, there are nine combinations of the arrangement positions of the beam spots.

  As an example, as shown in a schematic plan configuration in FIG. 3, each of the first and second pit rows 35A and 35B has two or more deviation amounts from the center of the recording track, and in this example, three types are provided. 1st and 2nd pit rows 35A and 35B are located in the first pit arrangement area 361 shifted to the boundary line side indicated by the two-dot chain line B, and the second pit located substantially on the recording track center indicated by the one-dot chain lines C1 and C2. The case where the arrangement area 362 and the third pit arrangement area 363 shifted to the guide track 31 side are provided will be described.

As described above, there are nine combinations of arrangement positions of the first and second beam spots 32A and 32B. 4A to I show a combination example in which the first and second beam spots 32A and 32B are arranged on the first pit arrangement region 361 in FIG. 4A to 4I, parts corresponding to those in FIG. 2 and FIG.
That is, in FIGS. 4A to 4C, the first beam spot 32A is irradiated to the recording track center position, and in FIGS. 4D to F, the first beam spot 32A is irradiated to the position shifted to the guide track 31 side. 4G to I show the case where the first beam spot 32A is irradiated to the position shifted to the boundary line side indicated by the two-dot chain line B, while FIGS. 4A, 4D and 4G show the second beam. When the spot 32B is irradiated to the position shifted to the boundary line side indicated by the two-dot chain line B, FIGS. 4B, 4E, and 4H show the case where the second beam spot 32B is irradiated almost on the center of the recording track. F and I indicate a case where the second beam spot 32B is irradiated to a position shifted to the guide track 31 side.

First, an example shown in FIG. 4B in which each beam spot is irradiated almost on the recording track center will be described. FIG. 5 shows the arrangement positions of the first and second beam spots 32A and 32B on the recording track in this case. 5, parts corresponding to those in FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description is omitted.
At this time, when the beam spots 32A and 32B irradiate the first to third pit arrangement regions 361 to 363, the reproduction signal amplitude obtained is a pattern shown in FIGS. In FIG. 6A, the time change of the signal level by the 1st beam is shown. The first beam spot 32A is irradiated almost on the center of the recording track, and in the first pit arrangement region 361, the first pit row 35A is shifted from the center of the recording track, so that the signal amplitude is medium. is there. In the second pit arrangement region 362, the first pit row 35A is located almost at the center of the recording track, so that the reproduction signal amplitude is large. In the third pit arrangement region 363, the first pit row 35A is recorded. Since it deviates from the track center, the reproduction signal amplitude becomes medium again.
On the other hand, in FIG. 6B, the time change of the signal level by the 2nd beam is shown. The second beam spot 32B is also irradiated almost on the center of the recording track, and in the first pit arrangement region 361, the second pit row 35B is shifted from the center of the recording track, so that the signal amplitude is medium. In the second pit arrangement 362, the second pit row 35B is located substantially at the center of the recording track, so that the reproduction signal amplitude is large. In the third pit arrangement region 363, the second pit row 35B is recorded again. Since it deviates from the track center, the reproduction signal amplitude is medium.

Next, the example shown in FIG. 4G described above in which both the first and second beam spots 32A are irradiated to the position shifted to the boundary line side indicated by the two-dot chain line B will be described. FIG. 7 shows the arrangement positions of the first and second beam spots 32A and 32B on the recording track in this case. 7, parts corresponding to those in FIGS. 3 and 4 are denoted by the same reference numerals, and redundant description is omitted.
At this time, when the beam spots 32A and 32B irradiate the first to third pit arrangement regions 361 to 363, the reproduction signal amplitude obtained is a pattern shown in FIGS. 8A and 8B. In FIG. 8A, the time change of the signal level by the 1st beam is shown. The first beam spot 32A is irradiated to a position shifted to the boundary side indicated by a two-dot chain line B. In the first pit arrangement region 361, the first pit row 35A is moved from the center of the recording track to the first beam. Since it is shifted to the same side as the irradiation position of the spot 32A, the signal amplitude becomes large. In the second pit arrangement region 362, the first pit row 35A is located substantially at the center of the recording track, so that the reproduction signal amplitude is medium. In the third pit arrangement region 363, the first pit row 35A is Since the position is shifted to the opposite side to the irradiation position of the first beam spot 32A, the reproduction signal amplitude becomes a smaller value.
On the other hand, FIG. 8B shows the time change of the signal level due to the second beam. The second beam spot 32B is also irradiated to a position shifted to the boundary line side indicated by the two-dot chain line B. In the first pit arrangement region 361, the second pit row 35B is the second beam spot 32B. Is shifted to the same side as the irradiation position of the second beam spot 32B from the center of the recording track, so that the signal amplitude becomes large. In the second pit arrangement 362, the second pit row 35B is located substantially at the center of the recording track, so that the reproduction signal amplitude is medium. In the third pit arrangement area 363, the second pit row 35B is Since the position is opposite to the irradiation position of the second beam spot 32B, the reproduction signal amplitude becomes a smaller value.

Further, the example shown in FIG. 4D described above where both the first and second beam spots 32A are irradiated to the position shifted toward the guide track 31 will be described. FIG. 9 shows the arrangement positions of the first and second beam spots 32A and 32B on the recording track in this case. 9, parts corresponding to those in FIG. 3 and FIG.
At this time, when each of the beam spots 32A and 32B irradiates the first to third pit arrangement regions 361 to 363, the obtained reproduction signal amplitude has a pattern shown in FIGS. In FIG. 10A, the time change of the signal level by the 1st beam is shown. The first beam spot 32A is irradiated to a position shifted toward the guide track 31, and in the first pit arrangement region 361, the first pit row 35A is irradiated from the center of the recording track to the first beam spot 32A. Since the position is shifted to the opposite side to the position, the reproduction signal amplitude is small. In the second pit arrangement region 362, the first pit row 35A is located substantially at the center of the recording track, so that the reproduction signal amplitude is medium. In the third pit arrangement region 363, the first pit row 35A is Since it is shifted to the same side as the irradiation position of the first beam spot 32A, the reproduction signal amplitude is maximized.
On the other hand, in FIG. 10B, the time change of the signal level by the 2nd beam is shown. The second beam spot 32B is also irradiated at a position shifted to the guide track 31 side. In the first pit arrangement area 361, the second pit row 35B has the second beam spot 32B from the recording track center. Since it is shifted to the opposite side to the irradiation position of the second beam spot 32B, the signal amplitude is small. In the second pit arrangement 362, the second pit row 35B is located substantially at the center of the recording track, so that the reproduction signal amplitude is medium. In the third pit arrangement area 363, the second pit row 35B is Since the position is shifted to the same side as the irradiation position of the second beam spot 32B, the reproduction signal amplitude is maximized.

From the above results, for example, as described above, when the first to third pit arrangements are provided, the reproduction signal amplitude is changed by each pit arrangement, and each beam spot to be irradiated is detected by detecting the change pattern. However, it is possible to detect which is shifted from the center of the recording track.
FIGS. 11 to 13 show combination patterns in which the reproduction signal amplitude changes along the first to third pit arrangements with respect to the irradiation positions of the respective beam spots. 11A to 11C, the levels of the reproduction signal amplitude obtained along the first to third pit arrangements for the combination of irradiation positions described in FIGS. 4A to 4C are shown as large, medium, and small, respectively. Similarly, FIGS. 12A to 12C show the levels of the reproduction signal amplitude obtained along the first to third pit arrangements for the irradiation position combinations described in FIGS. 4D to F, respectively. 13A to 13C show the levels of the reproduction signal amplitude obtained along the first to third pit arrangements for the irradiation position combinations described in FIGS. 4G to I, respectively. Since these combinations are all different, the irradiation position of each laser beam is shifted from the recording track center to which side, that is, in the radial direction in the case of an optical recording medium on a disk, from the obtained reproduction signal amplitude pattern. You can see if Therefore, it is possible to detect the positional deviation of each beam spot, and by adjusting the beam spot irradiation position based on this result, it is possible to irradiate each beam spot almost at the center of the recording track, which is stable and good. Recording and playback can be performed.
As shown in the example in the figure, by making the frequencies of the pit rows 35A and 35B different, crosstalk of the obtained reproduction signal can be suppressed and the reproduction signal can be detected satisfactorily.

In the above example, the first to third pit arrays 361 to 363 are provided. However, for example, even when only the first pit array 361 is provided, depending on the irradiation position of each beam spot, FIG. It becomes a different pattern shown to 14A-I. Therefore, it is possible to detect the positional deviation of each beam spot based on the level of the reproduction signal amplitude.
In this case, it is possible to detect the irradiation position deviation satisfactorily by appropriately selecting the arrangement position and the deviation amount of the pit row corresponding to each beam spot and making it different for each beam.
In the above-described example, the case where two beam spots are used has been described. However, in the case where the recording track is irradiated with three or more other beam spots, a similar pit row is provided and the reproduction signal amplitude is set. By detecting, similarly, the irradiation position of each beam spot can be detected satisfactorily.

Next, the optical pickup adjusting method, the optical pickup device, and the optical recording of the present invention for controlling the irradiation position of the beam using the optical recording medium and the multi-beam position detecting method of the present invention described above. An example of a playback device will be described.
First, FIG. 15 shows a schematic configuration of a main part of an example of an optical pickup device and an optical recording / reproducing device according to the present invention.
In this example, a case where a solid immersion lens (SIL) is used as the near-field light irradiation means 2 is shown. A condensing lens 70 is configured by arranging a near-field light irradiating means 2 and an optical lens 3 made of a solid immersion lens with their optical axes aligned in this order with respect to the optical recording medium 1. The solid immersion lens 2 is, for example, hemispherical or super hemispherical with a radius r, and the thickness along the optical axis is r when hemispherical, and n is the lens material when super hemispherical. r (1 + 1 / n). With such a configuration, it is possible to provide a condensing lens 70 having a high numerical aperture exceeding the numerical aperture NA of the optical lens 3.
Actually, the near-field light irradiating means 2 made of a solid immersion lens and the optical recording medium 1 are not in contact with each other, but the distance between the near-field light irradiating means 2 and the optical recording medium 1 is near-field light irradiating. Since it is sufficiently smaller than the thickness of the solid immersion lens of means 2, the interval is omitted in the following FIGS.
Then, for example, as shown in FIG. 16, first and second beam splitters 71 and 72 are disposed between the light source and photodetector (not shown) and the condenser lens 70. If the optical recording medium 1 is in the form of a disk, for example, it is mounted on a spindle motor (not shown) and rotated at a predetermined rotational speed.

Further, the condenser lens 70 is provided with means for controlling and driving in the tracking direction and the gap direction. Examples of this means include a biaxial actuator used for a general optical pickup and a slider used for a magnetic head device.
The form of the control drive means of these condensing lenses 70 is shown below.
FIG. 17 is a schematic configuration diagram of an example of an optical pickup device using a biaxial actuator as a control driving unit. As shown in FIG. 17, the condensing lens 70 is fixed to the holding unit 6 with the optical axes of the near-field light irradiating means 2 and the optical lens 3 made of a solid immersion lens or the like aligned, and the holding unit 6 is a gap. It is fixed to a biaxial pickup 9 controlled and driven in the direction and / or tracking direction. The biaxial pickup 9 includes a tracking direction control coil 8 that controls and drives the condenser lens 70 in the tracking direction, and a gap direction control coil 7 that controls and drives the condenser lens 70 in the gap direction.

The biaxial pickup 9 monitors the distance (gap) between the optical recording medium 1 and the near-field light irradiation means 2, for example, the total reflected return light amount from the gap detection beam spot, and feeds back the distance information. The distance between the near-field light irradiating means 2 and the optical recording medium 1 is kept substantially constant, and is controlled so as to avoid a collision between the near-field light irradiating means 2 and the optical recording medium 1. The
Further, in this biaxial pickup 9, it is possible to move the focused spot to a desired recording track by monitoring the amount of light returning in the tracking direction and feeding back the position information.

  Hereinafter, the schematic configuration of the optical pickup device will be described with reference to FIG. 15 again. Outgoing light emitted from a light source, for example, a semiconductor laser, is converted into parallel light (Li) by a collimator lens (not shown), passes through the first beam splitter 4, and passes through the condensing lens 70 to the optical recording medium 1. Is condensed on the information recording surface. The return light reflected from the information recording surface passes through the condenser lens 70, is reflected by the first beam splitter 4 (L2), and enters the second beam splitter 5. The return light (Lo) separated by the second beam splitter 5 is condensed on a gap control photodetector and a signal photodetector (not shown), and a gap error signal, a reproduction pit signal, and the like are generated. Detected.

  The return light reflected by the second beam splitter is also collected on the tracking photodetector, and a tracking error signal is detected. If necessary, the optical pickup device includes the remaining gap error component followed by the biaxial pickup that fixes the condenser lens 70 to the surface shake of the optical recording medium 1 and the assembly process of the condenser lens. A relay lens that can correct the generated error component by changing the interval between the two lenses may be inserted between the first beam splitter 4 and the optical lens 3. Further, when the condenser lens 70 is fixed to the slider, as a means for correcting the remaining gap error component followed by the slider and the error component generated during the assembly process of the condenser lens, the proximity lens constituting the condenser lens 70 is used. The field light irradiation means 2 may be fixed to a slider, and the optical lens 3 may be configured to be movable in the optical axis direction by, for example, a piezoelectric element.

  The above-described optical pickup device includes a reproduction-only unit that performs only reproduction, a recording-only unit that performs only recording, and a recording / reproducing unit that can perform both recording and reproduction. In addition, each of the optical pickup devices described above can be configured to include a device in which a magnetic coil or the like is incorporated in a part of the optical pickup device by combining the magneto-optical recording method and the near-field light reproducing method. The optical recording / reproducing apparatus includes a reproduction-only apparatus that performs only reproduction, a recording-only apparatus that performs only recording, and a recording / reproduction apparatus that can perform both recording and reproduction.

  FIG. 18 shows a schematic configuration of a more specific example of the optical pickup device according to the present invention. The optical pickup device has at least a light source 10 and drives and controls a collimating lens 11, a non-polarizing beam splitter 12, a polarizing beam splitter 13, a quarter-wave plate 14, a beam expander 15, a mirror 16, and a condenser lens 70. An actuator 17 is included.

In such a configuration, a plurality of lights emitted from the light source 10 (represented by a single optical path in the figure) are converted into parallel light by the collimating lens 11, and the non-polarizing beam splitter 12 and the polarizing beam splitter 13. The beam width is adjusted by the beam expander 15 through the ¼ wavelength plate 14 through the lens, and reflected by the mirror 16 and mounted on the actuator 17, that is, the optical lens 3 and near-field light irradiation. The light is incident on the means 2, for example, the SIL, and the optical recording medium 1 is irradiated as near-field light.
The light reflected from the recording surface of the optical recording medium 1 is reflected by the mirror 16 via the near-field light irradiating means 2 and the optical lens 3, and the polarizing beam splitter 13 via the beam expander 15 and the quarter wavelength plate 14. And is condensed by the lens 18 on the light receiving means 19. A part of the light that has passed through the polarizing beam splitter (PBS) 13 is reflected by the non-polarizing beam splitter (NPBS) 12 and detected by the light receiving means 21 by the lens 20. For example, the tracking signal and the RF reproduction signal are received by the light receiving means 19 that receives the light reflected from the polarization beam splitter 13, and the gap detection for controlling the distance between the near-field light irradiation means and the optical recording medium by the other light receiving means 21. The signal can be reproduced. As the light receiving means 19 for recording and reproduction, a photodetector having two or more light receiving portions corresponding to the number of beams is used. The same applies when the gap detection beam spot is set to two or more.

In this example, a case where gap detection is detected using a change in polarization is shown. That is, when the gap between the optical recording medium and the near-field light irradiation means, for example, the SIL is wide and the light is substantially totally reflected at the SIL end face, the polarization changes on the SIL surface. Light leaks. On the other hand, when the optical recording medium is close to the SIL and the near-field light leaks and is close to normal reflection, the amount of light leaking through the PBS 13 is small because the change in polarization is small. Gap detection can be performed using this difference, that is, a change in the total reflected return light amount.
As the gap detection method, various other methods such as a method of detecting a change in capacitance can be employed.

When irradiating two laser beams onto an optical recording medium with such an optical pickup device, as shown in FIG. 19, for example, N is sandwiched between guide tracks 31 formed of grooves or lands formed in a spiral shape. Two beam spots 32AN and 32BN are irradiated to the recording track 30N on the circumference. In FIG. 19, the beam spots 32AN-1, 32BN-1, 3AN + 1, and 32BN + 1 in the recording tracks 30N-1 and 30N + 1 before and after one turn are indicated by alternate long and short dash lines.
As a light source that emits two beams, for example, as shown in FIG. 20, for example, a schematic configuration of a main part of an example, a semiconductor laser 51 in which two light emitting ends 51 </ b> S are provided in parallel can be used. 18 can be used as the light source 10.

In the optical pickup apparatus described with reference to FIG. 18, the first and second light receiving means made up of, for example, a photodetector are arranged as the light receiving means 19 at the emission positions of the respective laser beams, thereby detecting the reproduction signal from each beam spot. be able to.
In order to adjust the irradiation position of the beam based on the detected result, for example, as shown in FIG. 21, a schematic configuration of a main part of an example of the optical recording / reproducing apparatus of the present invention, the first and second light receiving means. The signal reproduction means 92 compares the RF reproduction signals detected by the above, and the beam position detection means 93 detects the position where each beam spot is irradiated. Based on the detection result, the controller 94 outputs a signal for adjusting the irradiation position of the beam spot to the adjusting means 95.

As the adjustment means 95, for example, the adjustment method of the optical pickup according to the present invention in which the optical pickup is rotated along the surface of the optical recording medium can be applied for good adjustment. An example of the adjustment method in this case will be described with reference to the schematic plan configuration of FIGS. 22A and 22B. For example, as shown in FIG. 22A, the first and second beam spots 32A and 32B extend along the recording track extension direction indicated by the broken line t in the recording track 30 (tangential direction in the case of a disc-shaped optical recording medium). Are arranged. A direction (in the radial direction in the case of a disk-shaped optical recording medium) crossing the guide track 31 perpendicular to the recording track extension direction indicated by a broken line t is indicated by a broken line r.
At this time, as shown in FIG. 22B, for example, as shown in FIG. 22B, the pickup unit 37 that irradiates each laser beam is moved from the extending direction of the recording track indicated by the broken line t according to the result of the reproduction signal amplitude by the beam spots 32A and 32B. By rotating along the surface, the position where the first and second beam spots 32A and 32B are irradiated onto the recording track 30 is adjusted, and an appropriate position can be irradiated.
In this case, it is possible to accurately adjust a minute positional deviation of each beam spot only by controlling the angle at which the pickup unit 37 is rotated.
Further, as other means for adjusting the beam interval, a mechanical rotating means or an optical rotating means can be used.

The optical pickup device and the optical recording / reproducing device of the present invention can also be applied to other cases where, for example, a gap detection beam spot is irradiated separately from the recording / reproducing beam spot.
FIG. 23 shows a schematic configuration of an example of an optical pickup device when light having a wavelength different from that of the recording / reproducing beam spot is used as the gap detection beam spot. In FIG. 23, parts corresponding to those in FIG. In this case, for example, a light source 40 having a wavelength different from that of the light source 10 is used, and a collimator lens 41, a beam splitter 42, a polarization beam splitter 43, and a ¼ wavelength plate 44 are arranged on the optical axis of light emitted from the light source 40. A dichroic prism 45 is arranged.
In this optical pickup device, the gap detection light emitted from the light source 40 is converted into parallel light by the collimating lens 41 and transmitted through the beam splitter 42 and the polarization beam splitter 43, and the phase is adjusted by the quarter wavelength plate 44. After 1/4 conversion, the light is incident on the optical pickup 17 through the dichroic prism 45, and is irradiated on the predetermined recording track of the optical recording medium in the near field. The phase of the return light reflected from the optical recording medium 1 is again converted to ¼ by the ¼ wavelength plate 44 via the optical pickup 17 and the dichroic prism 45.
This example also shows a case where gap detection is detected by using a change in polarization. The gap between the optical recording medium and the near-field light irradiation means 2, for example, the SIL is wide, and light is substantially totally reflected at the end surface of the SIL. In this case, since the polarization changes on the surface of the SIL, a part of light leaks from the polarization beam splitter 43 in the return optical path, but the gap between the optical recording medium 1 and the near-field light irradiation means 2 is sufficiently small. When the near-field light leaks and is close to normal reflection, the amount of light leaking through the PBS 13 is small because the change in polarization is small. Therefore, the light transmitted through the polarization beam splitter 43 is separated by the beam splitter 42 and detected by the light receiving means 21 through the condensing lens 20 to detect this difference, that is, the change in the total reflected return light amount, Gap detection can be performed.
As the gap detection method, various other methods such as a method of detecting a change in capacitance can be employed.

  FIG. 24 shows a schematic plan view of an example of a state in which the optical recording medium 1 is irradiated with a beam spot by the optical pickup device having such a configuration. The recording / reproducing beam spots 32A and 32B are irradiated with a light having a wavelength of 405 nm, for example, and the gap detecting beam spot 33 with a light having a wavelength of 680 nm, for example, to irradiate the recording / reproducing area with a relatively wide area. can do.

As an optical recording medium usable in the optical pickup adjusting method, the optical pickup apparatus and the optical recording / reproducing apparatus using the same according to the present invention described above, various substrate configurations and optical recording media corresponding to the recording / reproducing methods are applied. can do. For example, as shown in FIG. 25A, when a concave guide track 31 so-called guide groove is provided on the medium surface 60 constituting the recording surface 61 of the optical recording medium 1, the guide track 31 is formed as shown in FIG. 25B. In the case of a convex shape, that is, a land shape, as shown in FIGS. 26A and 26B, the present invention is also provided when a planarizing layer 66 made of a protective layer or the like is provided so as to embed a concave or convex guide track 31. Can be applied.
Further, as shown in FIGS. 27A and 27B, when the guide track 31 has a concave shape or a convex shape, and the recording surface has a two-layer structure, the first and second recording surfaces 61A and 61B are provided. Similarly, as shown in FIGS. 28A and 28B, the same applies to the case where the flattening layer 66 is provided on the second recording surface 61B on the surface side among the recording surfaces having the two-layer structure.
29 and 30 show the case where the guide track 31 and the recording surface 61 are provided on the front surface and the back surface of the substrate 65, respectively, and the guide track 31 has a concave shape or a convex shape in FIGS. 29A and 29B, respectively. FIGS. 30A and 30B show the case where the planarizing layer 66 is provided on the concave or convex guide track 31. FIG. The optical recording / reproducing method according to the present invention can be applied to an optical recording medium having such various substrate shapes and recording surface configurations.

  Similarly, for the recording layer or the recording / reproducing method, the present invention can be applied to various optical recording media whose cross-sectional configurations are schematically shown in FIGS. FIG. 31A shows an example of the phase change recording medium 1A, in which a reflective layer 71, a dielectric layer 72, a phase change material layer 73, a dielectric layer 74, and a protective layer 75 are provided on a substrate 70. FIG. 31B shows an example of the magneto-optical recording medium 1B, in which a reflective layer 71, a dielectric layer 72, a magneto-optical recording layer 76, a dielectric layer 74, and a protective layer 75 are provided on a substrate 70. FIG. 31C shows an example of the dye recording medium 1 </ b> C, in which a reflective layer 71, a dielectric layer 72, a dye recording layer 77, a dielectric layer 74, and a protective layer 75 are provided on a substrate 70. FIG. 31D shows an example of the read-only medium 1D, and a recording mark so-called pit is formed on the substrate 70 by an uneven pit pattern (not shown), and a reflective layer 71, a dielectric layer 74, and a protective layer 75 are provided thereon. Thus, a recording medium is configured. By applying the present invention to these various recording and reproducing optical recording media, it becomes possible to perform stable near-field recording and reproducing at a high transfer rate.

Next, a description will be given of a lens shape when a solid immersion lens (SIL) is used as the near-field light irradiation means 2 in FIGS. In the case of using a solid immersion lens, the cross section thereof is, for example, a super hemisphere or a hemisphere, the object surface facing the optical recording medium is, for example, a flat surface, and the opposite surface of the object surface is a convex spherical surface. Further, the peripheral side surface is a biaxial pickup or a fixing surface with the slider.
In addition, since the gap interval between the solid immersion lens and the optical recording medium is about several tens of nanometers as described above, in order to secure a mechanical tilt margin between the lens and the optical recording medium, FIG. 32A and FIG. As shown in the schematic plan view of the side surface and the tip side of the example, the tip side facing the optical recording medium is processed into a conical shape or the like within a range that does not block the laser incident angle of the lens. Is preferred. A one-dot chain line e in the figure indicates the optical axis. In the example of FIG. 32, a case where the tip side opposite to the spherical portion 81 is conical and the tip 82 is planar is shown. In this case, if the radius of the spherical portion 81 is r, the thickness of the lens along the optical axis e is r (1 + 1 / n). When the spherical portion 81 is hemispherical, the thickness is r.
Further, as shown in FIGS. 33A and 33B, when the spherical portion 81 is a super hemisphere, the tip portion 82 has a shape that circumscribes a sphere having a radius r / n indicated by a one-dot chain line f. Also good. In FIGS. 33A and B, parts corresponding to those in FIGS. In this case, as shown in FIG. 34, the enlarged cross-sectional configuration of the tip portion of the light passes through the lens even when the optical axis of the incident light deviates from the optical axis of the lens as indicated by arrows Li1 to Li3. Since the optical path length is not substantially changed, the light can be substantially condensed at the distal end portion 82. Therefore, recording and reproduction can be performed stably, and fluctuations due to variations in optical axis adjustment can be suppressed when detecting the distance g from the optical recording medium 1, and assembly accuracy can be relaxed. Have
In the case where the spherical portion 81 is hemispherical, the same effect can be obtained if the tip portion 82 has a shape that circumscribes a sphere having a radius r.

Further, as shown in the schematic side view and the plan view in FIGS. 35A and 35B, the tip end portion 82 can be formed in a curved surface shape formed by one curved surface. 35A and 35B, parts corresponding to those in FIGS. 32A and 32B are denoted by the same reference numerals, and redundant description is omitted. Even in this case, as shown in the enlarged cross-sectional configuration of the tip portion in FIG. 36, the same effect can be obtained by making the tip portion 82 substantially circumscribing the r / n sphere. Also in this case, when the spherical portion 81 is hemispherical, the same effect can be obtained by making the tip portion 82 a shape roughly outlined as a sphere having a radius r.
In the near-field optical recording / reproducing system for the magneto-optical recording medium, a magnetic field is required at the time of recording and / or reproduction. Therefore, a magnetic coil or the like is attached to a part of the objective surface of the solid immersion lens. Also good.

When the solid immersion lens described above is used as a near-field light irradiation means, the material thereof has a large refractive index and a large transmittance with respect to the wavelength of the laser light source equipped in the optical pickup device and optical recording / reproducing device to be used. A material having low light absorption is preferable. For example, S-LAH79 manufactured by OHARA INC., Which is a high refractive index glass, Bi ₄ Ge ₃ O ₁₂ , SrTiO ₃ , KTaO ₃ , ZrO ₂ , HfO ₂ , high refractive index ceramics, high refractive index single crystal material, SiC, diamond, GaP, etc. are suitable.
Further, it is desirable that these optical lens materials have an amorphous structure or a cubic structure in the case of a single crystal. When the optical lens material has an amorphous structure or a cubic structure, a conventional ball polishing method and apparatus can be used. Furthermore, an etching process or a polishing process for manufacturing an optical lens can be easily applied without worrying about the orientation of the material.

Next, examples will be described.
(1) Example 1
The first embodiment is applied to the case where the number of beams is two and recording / reproduction is performed by irradiating two beam spots onto a spiral recording track. In this example, the recording / reproducing laser wavelength is set to 410 nm, and the beam interval in the extension direction of the recording track 30, that is, the so-called tangential direction is 3.5 μm, as shown in FIG. The beam spacing in the so-called radial direction is 140 nm, the pitch of the guide track 31 is 280 nm, the width of the guide track 31 is 49 nm, and the width of the recording track 30 sandwiched between the guide tracks 31 (first and second recording tracks 30A and 30A). Near-field recording / reproduction was performed with the sum of the width of 30B set to 231 nm. In FIG. 37, portions corresponding to those in FIG. Further, as shown in FIG. 38, the cross-sectional configuration of the optical recording medium is such that an Ag alloy layer 91, a SiN layer 92, a ZnS—SiO ₂ layer 93, a GeSbTe layer 94, and a ZnS—SiO ₂ layer 95 are formed on a polycarbonate substrate 90. Then, an SiN layer 96 was sequentially laminated to constitute an optical recording medium.
In such an optical recording medium 1, the first and second pit rows similar to the example described with reference to FIG. 3 are formed in a part of the recording track 30. In this example, the frequency of the first pit row is set to 7 MHz, the frequency of the second pit row is set to 3 MHz, and the position deviation of each beam spot from the recording track is detected with a good reproduction signal in which crosstalk is suppressed. 21 and 22 can be used to adjust the irradiation position of each beam spot to substantially the center of the recording track by using the adjusting means by the rotating mechanism of the optical pickup described above, thereby obtaining good recording / reproducing characteristics. It was.

Further, in the optical recording medium according to the first embodiment, the two beam spots 32A and 32B are arranged symmetrically between the guide tracks 31 and are adjacent to the guide tracks 31 so as to partially irradiate the guide tracks 31. Therefore, even when the guide track 31 is a pit or wobble other than the groove or land, a stable signal can be obtained.
Also, as described above, for example, two recording / reproducing signals by two laser beams can be recorded in a recording area on one spiral, so that a high transfer rate of recording / reproducing can be achieved without rotating the disk at high speed. It becomes possible. That is, good recording and reproduction of signals can be performed at a high transfer rate that has been difficult in the past.

(2) Example 2
Next, the second embodiment is applied to the case where the number of beams is three, two are for recording / reproducing and tracking, and one is for gap detection. In this case, the wavelength of the two recording / reproducing and tracking lasers is 410 nm, the beam spacing in the tangential direction is 3.5 μm, the beam spacing in the radial direction is 140 nm, and the wavelength of one laser for the gap servo Was 650 nm, and the beam spot was arranged approximately at the center between the guide tracks 31. FIG. 39 shows a schematic plan configuration on the optical recording medium in this case. In FIG. 39, parts corresponding to those in FIG. Also in this example, the pitch of the guide track 31 is 280 nm, the width of the guide track 31 is 49 nm, and the width of the recording track 30 is 231 nm. Further, the cross-sectional configuration of the optical recording medium 1 was the same as the example described in FIG.

  In this example as well, the first and second pit trains having a frequency of 7 MHz and a frequency of 3 MHz are formed on a part of the first and second recording tracks 32A and 32B of the optical recording medium, and the example described in FIG. Similarly formed. By reproducing these pit rows with two beam spots for recording / reproduction with the above-described arrangement, the positional deviation of each beam spot from the recording track is detected with a good reproduction signal with suppressed crosstalk. By using the adjusting means by the rotating mechanism of the optical pickup described in FIGS. 21 and 22, the irradiation position of each beam spot can be adjusted to substantially the center of the recording track, thereby obtaining good recording / reproducing characteristics. .

Also in the second embodiment, the two beam spots are arranged symmetrically between the guide tracks 31 and are arranged adjacent to the guide track 31 so as to partially irradiate the guide track 31. The guide track 31 can be followed stably, and a stable signal can be obtained even when the guide track 31 is a pit or wobble other than a groove or land.
Also, as described above, for example, two recording / reproducing signals by two laser beams can be recorded in a recording area on one spiral, so that a high transfer rate of recording / reproducing can be achieved without rotating the disk at high speed. It becomes possible. That is, it is possible to record / reproduce a high-transfer recording / reproducing signal that has been difficult in the past.
In the second embodiment, in addition to the two lasers for recording / reproducing and tracking, one laser for gap servo is arranged at the center of the same recording guide groove interval, so that it is stable even during recording / reproducing. This makes it possible to control the gap servo. That is, it is possible to record / reproduce a high-transfer recording / reproducing signal that has been difficult in the past.

As described above, according to the optical recording medium, the multi-beam position detection method, the optical pickup adjustment method, the optical pickup device, and the optical recording / reproducing device of the present invention, near-field optical recording and When reproducing, by reproducing a pit row arranged at a position shifted from the recording track center on the optical recording medium with a plurality of recording / reproducing beam spots in a recording / reproducing area sandwiched between the guide tracks, It is possible to satisfactorily detect an irradiation position shift of a plurality of beam spots, and an irradiation position of the beam spot can be adjusted based on the detected beam spot position shift.
That is, the present invention provides means for detecting and adjusting a change in reproduction signal amplitude caused by non-uniformity in beam interval and arrangement due to beam spot irradiation position deviation.

In addition, it is possible to increase the recording / reproducing signal transfer rate, which is a limit in the conventional near-field optical recording / reproducing method, without rotating the disk at a high speed.
Further, when the arrangement of a plurality of recording / reproducing beam spots is separated into a beam spot for maintaining a gap and a beam spot for recording / reproducing as described above, a near-field light irradiation means such as a solid immersion lens and an optical recording medium Therefore, the stability of recording / reproducing with respect to the optical recording medium can be improved.
In other words, according to the present invention, it is possible to easily obtain a high transfer rate in near-field recording / reproduction using a condensing lens having a large numerical aperture. As a result, it becomes possible to provide an optical recording medium, an optical pickup device, and an optical recording / reproducing device corresponding to the high transfer rate expected.

In addition, this invention is not limited to each example demonstrated above, A various other deformation | transformation and change are possible. For example, as a light source used for an optical pickup device or an optical recording / reproducing device, for example, a semiconductor laser of 780 nm band, 680 nm band, 660 nm band, 650 nm band, 635 nm band, 400 nm band, 415 nm band, etc. can be used. It is also possible to use a light source.
As the near-field light irradiation means, various means such as a solid immersion mirror (SIM) using a polygonal mirror can be used in addition to the above-described solid immersion lens.
In addition, for example, in the case of reproduction only, a plurality of beam spots are arranged by separating light emitted from one light source using a light separating means such as a diffraction grating without separately providing a light source that emits a plurality of beams. Needless to say, the various configurations of the optical recording medium and the various configurations of the optical pickup device and the optical recording / reproducing device can be modified and changed without departing from the configuration of the present invention.

FIG. 2A is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. B is a schematic plan view of an example of an optical recording medium according to the present invention. A is a schematic plan view showing an example of an irradiation position of a laser beam. B is a schematic plan view showing an example of a laser beam irradiation position. C is a schematic plan view showing an example of a laser beam irradiation position. D is a schematic plan view showing an example of a laser beam irradiation position. E is a schematic plan view showing an example of the irradiation position of the laser beam. F is a schematic plan configuration diagram showing an example of a laser beam irradiation position. 1 is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. FIG. 2A is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. FIG. 3B is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. C is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. FIG. 3D is a schematic plan configuration diagram of a main part of an example of the optical recording medium according to the present invention. E is a schematic plan view of a main part of an example of the optical recording medium according to the present invention. F is a schematic plan view of the main part of an example of the optical recording medium according to the present invention. G is a schematic plan view of a main part of an example of an optical recording medium according to the present invention. H is a schematic plan view of a main part of an example of the optical recording medium according to the present invention. I is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. 1 is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. 1 is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. 1 is a schematic plan configuration diagram of a main part of an example of an optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal by the optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. C is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. C is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. C is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. A is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. B is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. C is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. D is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. E is a figure which shows an example of the reproduction signal level in the optical recording medium by this invention. F is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. G is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. H is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. I is a diagram showing an example of a reproduction signal level in the optical recording medium according to the present invention. It is a schematic block diagram of the principal part of an example of the optical pick-up apparatus of this invention. It is a schematic block diagram of the principal part of an example of the optical pick-up apparatus of this invention. It is a schematic block diagram of the principal part of an example of the optical pick-up apparatus of this invention. It is a schematic block diagram of an example of the optical pick-up apparatus of this invention. It is a schematic plane block diagram of an example of the irradiation aspect of a multi beam. It is a schematic cross-sectional block diagram of an example of a semiconductor laser apparatus. It is a block block diagram of the principal part of an example of the optical recording / reproducing apparatus by this invention. A is an explanatory view of an example of a method of adjusting an optical pickup according to the present invention. B is an explanatory view of an example of an adjustment method of an optical pickup according to the present invention. It is a schematic block diagram of an example of the optical pick-up apparatus of this invention. It is a schematic plane block diagram of an example of the irradiation aspect of a multi beam. A is a schematic perspective view of a main part of an example of an optical recording medium. B is a schematic perspective view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic cross-sectional view of a main part of an example of an optical recording medium. B is a schematic cross-sectional view of a main part of an example of an optical recording medium. C is a schematic cross-sectional view of a main part of an example of an optical recording medium. D is a schematic cross-sectional view of a main part of an example of an optical recording medium. A is a schematic side view of an example of a solid immersion lens. B is a schematic plan view of an example of a solid immersion lens. A is a schematic side view of an example of a solid immersion lens. B is a schematic plan view of an example of a solid immersion lens. It is a schematic cross-section block diagram of the front-end | tip part of a solid immersion lens. A is a schematic side view of an example of a solid immersion lens. B is a schematic plan view of an example of a solid immersion lens. It is a schematic cross-section block diagram of the front-end | tip part of a solid immersion lens. It is a schematic plane block diagram which shows the beam arrangement | positioning aspect on the optical recording medium in an Example of this invention. 1 is a schematic cross-sectional configuration diagram of a main part of an example of an optical recording medium in an embodiment of the present invention. It is a schematic plane block diagram which shows the beam arrangement | positioning aspect on the optical recording medium in the Example of this invention.

Explanation of symbols

  1. Optical recording medium, 1A. Phase change recording medium, 1B. Magneto-optical recording medium, 1C. Dye recording medium, 1D. 1. Read-only recording medium 2. near-field light irradiation means; Optical lens, 4. 4. first beam splitter; Second beam splitter, 6. 6. holding part; 7. Gap direction control coil; Coil for tracking direction control, 9.2 axis pickup, 10. 10. light source Collimating lens, 12. Non-polarizing beam splitter, 13. 14. polarizing beam splitter, 14.1 / 4 wavelength plate, 15. Beam expander, 16. Mirror, 17. Actuator, 18. Lens, 19. Light receiving means, 20. Lens, 21. Light receiving means, 30. Recording track, 30A. Recording track, 30B. Recording track, 30P. Pit row area, 30R. Recording / playback area, 31. Guide track, 32A. First beam spot, 32B. Second beam spot, 33. Gap detection beam spot, 35A. First pit row, 35B. Second pit row 37. Pickup section, 40. Light source, 41. Collimating lens, 42. Beam splitter 43, polarization beam splitter 44.1 / 4 wavelength plate 45. Dichroic prism 51. Semiconductor laser, 51S. Emission end, 52. Semiconductor laser, 52S. Emission end, 53. Semiconductor laser, 53S. Light emitting end, 60. Medium surface 61. Recording surface, 63. End face, 65. Substrate, 66. Planarizing layer, 70. Condensing lens, 71. Reflective layer, 72. Dielectric layer, 73. Phase change recording layer, 74. Dielectric layer, 75. Protective layer, 76. Magneto-optical recording layer, 77. 81. Dye recording layer Bulbous part, 82. Tip, 91A. First light receiving means, 91B. Second light receiving means, 92. Signal comparison means, 93. Beam position detecting means, 94. Controller, 95. Adjusting means 361. First pit arrangement region, 362. Second pit arrangement region, 363. Third pit arrangement area

Claims (16)

An optical recording medium that is recorded and / or reproduced by near-field optical recording with two or more laser beams,
An optical recording medium comprising at least one pit row area in which a pit row is arranged at a position shifted from the center of the recording track. 2. The optical recording medium according to claim 1, wherein a pit row arranged at a position deviated from the center of the recording track is provided for each of the two or more laser beams. The optical recording medium according to claim 2, wherein the frequency of the pit row provided for each of the two or more laser beams is different. 2. The optical recording medium according to claim 1, wherein an amount of the pit row deviating from the recording track center is set to 2 or more. The optical recording medium according to claim 2, wherein the amount of deviation of the pit row from the center of the recording track is set to 2 or more. The optical recording medium according to claim 3, wherein an amount of the pit row deviating from the recording track center is set to 2 or more. A multi-beam control method for near-field irradiation of two or more laser beams on an optical recording medium,
The irradiation position shift from the recording track center at the irradiation position of the multi-beam is detected by reproducing at least one pit row provided at a position shifted from the recording track center of the optical recording medium. Multi-beam position detection method. The optical recording medium is provided with a pit row arranged at a position shifted from the recording track center for each of the two or more laser beams.
The multi-beam position detection method according to claim 7, wherein an irradiation position shift from the recording track center is detected for each laser beam. 9. The frequency of a pit row provided for each of the two or more laser beams of the optical recording medium is different, and detection of an irradiation position shift from the recording track center of the multi-beam is performed for each frequency. Multi-beam position detection method. An optical pickup adjustment method for irradiating an optical recording medium with two or more laser beams in a near field,
By reproducing at least one or more pit rows arranged at a position deviated from the recording track center of the optical recording medium, the irradiation position deviation of at least one or more of the two or more laser beams from the recording track center is reduced. An adjustment method of an optical pickup, characterized by detecting and adjusting the irradiation position of the laser beam based on the detected amount. By rotating the arrangement direction of the irradiation positions of the multi-beams along the surface of the optical recording medium from the extension direction of the recording tracks of the optical recording medium, the irradiation positions of the two or more laser beams are changed to the recording tracks. The method of adjusting an optical pickup according to claim 10, wherein control for moving to the center is performed. An optical pickup device that irradiates an optical recording medium with two or more laser beams in a near field,
At least one or more pit rows arranged at positions shifted from the recording track center of the optical recording medium are reproduced to adjust the irradiation position deviation of at least one or more of the two or more laser beams from the recording track. An optical pickup device. A rotation mechanism is provided that rotates the arrangement direction of the irradiation positions of the laser beams at an arbitrary angle along the surface of the optical recording medium from the extending direction of the recording track of the optical recording medium. The optical pickup device according to claim 12. An optical recording / reproducing apparatus having an optical pickup device that irradiates an optical recording medium with two or more laser beams in a near field,
A light receiving means for detecting at least one or more pit rows arranged at a position deviated from the recording track center of the optical recording medium;
Signal comparison means for comparing the reproduction signal detected from the light receiving means;
Beam position detecting means for detecting an irradiation position shift of at least one of the two or more laser beams from the recording track based on the compared signal;
An optical recording / reproducing apparatus comprising: at least adjusting means for adjusting the position of the at least one beam based on the irradiation position deviation amount. As the adjusting means, an optical pickup section that irradiates the optical recording medium with the two or more laser beams is applied at an arbitrary angle along the surface of the optical recording medium from the extending direction of the recording track of the optical recording medium. The optical recording / reproducing apparatus according to claim 14, further comprising a rotating mechanism that rotates. An optical recording / reproducing method for performing recording and / or reproduction by irradiating an optical recording medium with two or more laser beams in a near field,
At least one or more pit rows arranged at positions shifted from the recording track center of the optical recording medium are reproduced to detect an irradiation position deviation of at least one of the two or more laser beams from the recording track. And recording and / or reproducing by adjusting the irradiation position of the one or more beams based on the amount of positional deviation.

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