JP2792157B2 - Optical information recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an optical information recording apparatus for irradiating an optical recording medium with convergent light from a light source to optically record, reproduce, and erase information. More particularly, the present invention relates to an optical information recording / reproducing apparatus that irradiates a plurality of converging lights from an optical head onto an optical recording medium to optically record and reproduce information.

[Prior Art] With the development of information processing systems in recent years, the optical information recording / reproducing apparatus has a so-called high transfer rate capable of recording and reproducing information at high speed in addition to the conventional large capacity. It is strongly desired, and various attempts have been made for it (The 49th Japan Society of Applied Physics (Autumn) 1988, 4p-ZD-
1, 4p-ZD-2, etc.). As one method of increasing the transfer rate, a so-called multi-beam optical head has been proposed, in which a plurality of recording / reproducing convergent spots of the optical head are provided.

2. Description of the Related Art Conventionally, as an optical information recording / reproducing apparatus using this kind of multi-beam optical head, for example, there is one as disclosed in Japanese Patent Application Laid-Open No. 61-117744. As shown in FIG. 15, this is a plurality (three in the example shown) of which light emission can be controlled independently.
A laser diode array 100 in which laser diodes are integrally formed in a straight line and at equal intervals, one condensing lens 101 for converting output light from the laser diode array 100 into parallel light, Objective lens 10 for converging light into a minute spot
2, a polarizing beam splitter 103 for separating incident light and reflected light, and a plurality of beam separation detecting means for separating reflected light from a plurality of beam spots and detecting a signal.
104, a two-part detector 105 for detecting one track position, and a set of focus error detection systems 106.

Then, a plurality of beam spots (three in the illustrated example) 10
7 to 109, as shown in FIG.
Are irradiated onto the plurality of tracks 111, 111... To record or reproduce information on the plurality of tracks 111, 111.

By the way, in the case of the multi-beam optical head, the second
As shown in FIG. 17, a plurality of beam spots 107 to 109 linearly arranged at equal intervals are
When it is attempted to arrange the laser diodes along the distance, it is necessary to make the interval between a plurality of laser diodes arranged in the laser diode array 100 extremely narrow due to factors such as the magnification of the optical system. There was a problem that becomes. In addition, when the distance between a plurality of laser diodes arranged in the laser diode array 100 is very close, there is a problem that adjacent laser diodes thermally interfere with each other.

Therefore, multiple beam spots arranged linearly
By tilting 112 to 120 by a predetermined angle θ with respect to the radial direction A of the optical disk 110 as shown in FIG. 18, the interval between a plurality of laser diodes arranged in the laser diode array 100 is increased. It has also been proposed to set the diode array 100 to a value that can be actually manufactured.

However, this case has the following problems. That is, the optical information recording / reproducing device is
As shown in FIG. 18, a plurality of beam spots 112 to 120 are arranged linearly at equal intervals.
Therefore, when a large number of beam spots 112 to 120 are arranged so as to be inclined by an angle θ with respect to the radial direction A of the optical disk 110 as shown in FIG. 18, the tracks 111, 111. Since it is formed in an arc shape having a predetermined radius of curvature, a plurality of beam spots 112 to 120
Cannot be positioned on the corresponding tracks 111, 111..., And the beam spots at both ends deviate from the tracks 111, 111. Therefore, even if you run the tracking servo, all beam spots 112
~ 120 at the same time and accurately each track 111,11
.. Cannot be tracked up, and information cannot be simultaneously recorded or reproduced on a plurality of tracks 111.

Therefore, in order to solve these problems, a plurality of beam spots 121 to 124 are formed along the radial direction of the optical disk 110 to a plurality of adjacent tracks 111, 111... P as shown in FIG. It is also considered to arrange at corresponding intervals. By doing so, the interval between the plurality of laser diodes arranged in the laser diode array is set wide so that the production of the laser diode array 100 is practically possible, and all the beam spots 121 to 121 are formed. 124 can be simultaneously and accurately tracked on the respective tracks 111, 111...

[Problems to be Solved by the Invention] However, the above-described conventional technology has the following problems. That is, a plurality of beam spots 12
When 1 to 124 are arranged at intervals corresponding to a plurality of times the adjacent track interval P along the radial direction of the optical disk 110, the data of the tracks 111, 111. As shown in FIG. 20, a plurality of beam spots 125 to 128 are
Each time the 110 makes one rotation, the track jumps to the adjacent track 111, 111..., And after all the tracks 111, 111. Not the tracks 111, 111 ...
A special track jump operation is required to make the optical head jump up to this point. Therefore, there is a problem that a control circuit for controlling the tracking operation of the optical head becomes complicated, which leads to a significant increase in cost.

Means for Solving the Problems Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to form a plurality of beam spots on a track of an optical recording medium. Are arranged at predetermined intervals corresponding to a plurality of track intervals along a direction perpendicular to the direction of the laser diode array, and the interval between the plurality of laser diodes arranged in the laser diode array is set to a value that can be practically manufactured by the laser diode array. Even if the beam spot is set to be wide so that all the beam spots can be simultaneously and accurately tracked on each track, there is no need to use a circuit for performing complicated tracking control. An object of the present invention is to provide an optical information recording / reproducing apparatus capable of avoiding a significant increase in cost.

That is, the invention described in claim 1 of the present invention provides an optical head having an imaging optical system for irradiating an array of M beam spots on an optical recording medium, and a spiral track for M multi-tracks. Comprising an optical recording medium having
What is claimed is: 1. An optical information recording medium reproducing apparatus for optically recording and reproducing information on said optical recording medium by using an optical head, comprising: Are arranged along a direction orthogonal to the above, and when the interval between adjacent tracks is P, the interval between adjacent spots is (M + 1) P and the interval between one track is MP. ing.

The multiple tracks of the optical recording medium are configured, for example, to each have a pre-group.

Further, the multiple tracks of the optical recording medium are configured such that, for example, only one track has a pre-group.

Further, among the multiple tracks of the optical recording medium, for example, only one of the tracks is composed of a ROM, a phase groove, light and shade having different reflectivities, and the like.

In the multiplex track of the optical recording medium, for example, a groove depth of a track other than the track for detecting a tracking error signal is λ / 4n (where λ is the wavelength of the light beam, and n is the optical recording medium). (The refractive index of the substrate).

Furthermore, the multiple tracks of the optical recording medium are:
For example, the depth of the groove of the tracking error signal detection track is λ / 8n (where λ is the wavelength of the light beam,
n is configured to be the refractive index of the substrate of the optical recording medium).

According to a fourth aspect of the present invention, there is provided an apparatus comprising: an optical head having an imaging optical system for irradiating an array of M beam spots onto an optical recording medium; and (M-2) multiple tracks. An optical recording medium having a single tracking error signal detection track in a spiral shape, and optically recording and reproducing information on the optical recording medium by an optical head. When M beam spot arrays are arranged from the optical head on the optical recording medium along a direction perpendicular to the track, and when the interval between adjacent tracks is P, the beam spots at both ends are determined. The distance between adjacent spots excluding MP is 1
The tracks are arranged so that the interval between the tracks is (M-1) P, and the tracking error signal is detected at the spots at both ends of the beam spot row.

In this case, the spots at both ends of the beam spot array may be shifted from the track in a direction orthogonal to different tracks.

Further, the shift amount of the spots at both ends may be set to about half of the interval between adjacent tracks.

[Operation] That is, in the device according to the first aspect of the present invention, M beam spot trains are formed from the optical head by:
When arranged along the direction perpendicular to the track on the optical recording medium, and the adjacent track interval is P,
Since the arrangement is such that the interval between adjacent spots is (M + 1) P and the interval between one track is MP, M beam spot trains from the optical head are placed on the optical recording medium. Even if the beam spots are arranged along the direction perpendicular to the track and all beam spots are located on the track without being affected by the curvature of the track,
The interval between adjacent spots can be increased to (M + 1) P. In addition, the interval between adjacent spots is (M +
1) P and P are arranged so that the interval between one track is MP, so that adjacent spots are M
It is located on a track adjacent to the multitrack of the book. Therefore, by tracking one beam spot on one track, information recording or reproduction can be performed on all M tracks with the M beam spots.

In the apparatus described in claim 4 of the present invention, M beam spot arrays are arranged from an optical head on an optical recording medium along a direction perpendicular to the track, and Assuming that the interval between adjacent tracks is P, the interval between adjacent spots excluding the beam spots at both ends is MP, and the interval between one track is (M-1) P. Since the tracking error signal is detected at the spots at both ends, an optical recording medium having (M-2) multiple tracks and one tracking error signal detection track in a spiral shape is used. Even in this case, the same operation as the device according to claim 1 can be achieved.

[Embodiments] The present invention will be described below based on the illustrated embodiments.

2 and 4 show one embodiment of the optical information recording / reproducing apparatus according to the present invention.

In the figure, reference numeral 1 denotes an optical information recording / reproducing device.

The optical information recording / reproducing apparatus 1 includes a semiconductor laser 2 in which a plurality (five in the illustrated example) of independently drivable light emitting elements are linearly arranged, and a cross-sectional ellipse emitted from the semiconductor laser 2. Multiple shaped laser beams LB _{1 to} L
A collimator lens 3 for converting the B ₅ into parallel light, a laser beam LB ₁ ~LB ₅ is converted into parallel light by the collimator lens 3, a beam shaping prism 4 for shaping the circular cross section of the light, is the shaping the laser beam LB ₁ ~LB ₅
And a quarter-wave plate 6 for mutually converting linearly polarized light and circularly polarized light into a light beam to be irradiated on the optical disk 8 and a reflected light from the optical disk 8 to be described later.
And the laser beams LB _{1 to} LB passing through the quarter-wave plate 6
Objective lens 7 for converging and irradiating ₅ on an optical disk 8
And an optical disk 8 as an optical recording medium to which the laser beams LB _{1 to} LB ₅ converged by the objective lens 7 are irradiated, and a reflected laser beam LB ₁ from the optical disk 8 separated by the polarizing beam splitter 5. To LB ₅ , and the laser beams LB _{1 to} LB ₅ separated by the beam splitter 9.
While a condenser lens 10 for condensing the, receiving the laser beam LB ₁ ~LB ₅ condensed by the condenser lens 10 7
And number of the light receiving device 11 ₁ to 11 _5, a condenser lens 12 for condensing the other laser beam LB ₁ ~LB ₅ separated by the beam splitter 9, which is condensed by the condenser lens 12 a pinhole 13 for passing only the middle laser beam LB ₃ of the laser beam LB ₁ ~LB _5, the laser beam LB ₃ taken out by the pinhole 13
Condenser lens 14 and cylindrical lens 15 for detecting a focusing error signal by an astigmatism method
And a four-division light receiving element 16 for receiving a beam formed by the condenser lens 14 and the cylindrical lens 15.

The optical disk 8 as the optical recording medium is
As shown in FIG. 5, M multiplex tracks 17, 17... For recording information are formed in a spiral shape.
Each of the tracks 17, 17,... Has a pre-group 17a. The adjacent tracks 17, 17,... Are arranged with an interval P therebetween. This adjacent track 1
The interval P between 7, 17,... Is set to, for example, 1.6 μm.

In the optical information recording / reproducing apparatus 1,
As shown in FIG. 2, a plurality of elliptical laser beams LB _{1 to} LB ₅ emitted from the semiconductor laser 2 are converted into parallel light by a collimator lens 3 and then converted into a circular beam by a beam shaping prism 4. Be shaped. After that, the laser beams LB _{1 to} LB ₅ pass through the polarizing beam splitter 5 and the 波長 wavelength plate 6 and are focused on the tracks 17, 17...

The reflected light from the tracks 17, 17,... Of the optical disk 8 returns along the same path as described above, is reflected by the polarization beam splitter 5, and is separated into two directions by the beam splitter 9. One of the laser beams LB _{1 to} LB ₅ is a condensing lens
By 10, seven light receiving elements 111 to 115 are imaged onto a plurality of tracks 17, 17 by these light receiving elements 11 ₁ to 11 ₅
Are simultaneously read. Each light-receiving element 11 ₁ to 11 _5, as shown in FIG. 6, a differential amplifier 50
Is connected to the _{1-50 5,} image information is obtained as the output signal of the differential amplifier 50 _{1-50 5.}

The other laser beams LB _{1 to} LB ₅ separated by the beam splitter 9 are focused by the condenser lens 12, and then only the central laser beam LB ₃ passes through the pinhole 13, and An image is formed on the four-divided light receiving element 16 via the cylindrical lens 14 and the lens 14, and a tracking error signal is obtained, and a focusing error signal is obtained by the astigmatism method.

The tracking error signal is obtained as follows. That is, as shown in FIG. 7, the four-divided light receiving element 16 has adjacent light receiving elements 16a and 16b and light receiving elements 16c and 16d connected to addition amplifiers 54 and 55, respectively. 55 is connected to the differential amplifier 56. Then, a tracking error signal is obtained from the differential amplifier 56.

In addition, the astigmatism method, as is known, makes the focus of the laser beam in the x-axis direction and the focus in the y-axis direction different from each other by the cylindrical lens 15 so that the laser beam is focused as shown in FIG. A focusing error signal is obtained by utilizing the fact that a middle circular beam can be obtained in the state of being turned. The above four-divided light receiving element 16
Is a light receiving element located on a diagonal line as shown in FIG.
16a and 16c and light receiving elements 16b and 16d are added amplifiers 51 and 52.
Are respectively connected to these summing amplifiers 51 and 52.
Are connected to a differential amplifier 53.

Then, when the focus is on, as shown in FIG. 9 (a), the output of the differential amplifier 53 becomes 0, and when the focus is off, as shown in FIGS. 9 (b) and 9 (c). As described above, when the output of the differential amplifier 53 becomes + or-, a focusing error signal is obtained.

By the way, the optical information recording / reproducing apparatus according to this embodiment arranges M beam spot rows from an optical head on an optical recording medium along a direction orthogonal to the track, and furthermore, the adjacent track interval , P is arranged so that an interval between adjacent spots is (M + 1) P and an interval between one track is MP.

First, a semiconductor laser 2 in which a plurality of (five in the illustrated example) independently drivable light emitting elements are linearly arranged,
It is configured as follows.

That is, as shown in FIG. 10, the semiconductor laser 2 includes a p-GaAs substrate 19, an n-GaAs layer 20 formed on the substrate 19 to form a current confinement layer, and a P-Ga _1-x Al _x As layer 21 constituting a cladding layer formed on
A p-Ga _1-y Al _y As layer 22 constituting an active layer formed on the p-Ga _1-x Al _x As layer 21; and a p-Ga _1-y Al _y As layer 22
P-Ga _1-x Al _x As layer forming a cladding layer formed thereon
23 and an n-GaAs layer 24 constituting a gap layer formed on the p-Ga _1-x Al _x As layer 23, constitute a main part thereof,
On the back side of the p-GaAs substrate 19, a p-side electrode is
25, on the other hand, a plurality of n-type electrodes 26 to
The V-grooves 33 to 37 formed by mesa etching or the like are provided in the n-GaAs layer 20 constituting the current confinement layer. laser element 18 _{1-18 5} are formed.

Then, between the p-side electrode 25 and the n-side electrodes 26 to 30,
By independently applying a driving voltage, in the active region of the semiconductor laser element 18 _{1-18 5,} the V grooves in n-GaAs layer 20 of the current confinement layer having a polarity opposite to that of the substrate 19
33-37 current is injected from the direction of the arrow through the laser oscillation occurs in the _{p-Ga 1-y Al y} As layer 22 as an active layer, a plurality of laser beams of elliptical shape from the semiconductor laser element 18 _{1-18 5} LB ₁ ~LB ₅ is adapted to be obtained. These laser beams LB _{1 to} LB ₅ are applied to the semiconductor laser elements 18 ₁ to 18 ₁
8 is emitted in ₅ equal intervals to the interval x ₁ ~x ₄ of.

Further, the multi-beam optical head according to this embodiment forms the semiconductor laser configured as described above and a plurality of beams from the semiconductor laser on the optical recording medium along a direction orthogonal to the track. And an image forming optical system.

That is, the multi-beam optical head 40 is an imaging optical system mainly composed of members of the optical information recording / reproducing apparatus 1 other than the optical disk 8 in addition to the semiconductor laser 2.
As shown in FIG. 2, the optical head 40 is movable along the radial direction A of the optical disk 8 by a driving means (not shown).

Then, as shown in FIG. 2, the plurality of laser beams LB _{1 to} LB ₅ emitted from the semiconductor laser 2 are collimated by a collimator lens 3, a beam shaping prism 4, a polarizing beam splitter 5, and a 板 wavelength plate 6. through, a plurality of beam spots BS ₁ to BS ₅ is converged by the objective lens 7, as shown in FIG. 4, it is imaged in a linear shape along the radial direction a on the optical disc 8.

A plurality of beam spots BS _{1 to} BS ₅ radiated linearly on the optical disk 8 have a distance P between adjacent tracks of the optical disk 8 as shown in FIG.
An image is formed so that the interval between adjacent beam spots is (M + 1) P.

That is, tracks 17, 17... Adjacent to the optical disk 8
Is 1.6 μm, the interval between adjacent beam spots is given by (M + 1) P, where M is 5, which is 9.6 μm. Then, as shown in FIG. 4, as the imaging optical system 41 of the optical head 40, if the magnification was used three times the reduction optical system, the interval of the semiconductor laser element 18 _{1-18 5} in the semiconductor laser 2, It is about 30 μm.
This value is practically manufacturable values semiconductor laser 2, moreover has become capable of preventing thermal interference of the semiconductor laser element 18 _{1-18 5} adjacent values.

In the above configuration, in the optical information recording / reproducing apparatus according to this embodiment, for example, information is reproduced as follows. That is, in order to reproduce information, as shown in FIG. 2, a plurality of laser beams LB _{1 to} LB ₅ are emitted from the semiconductor laser 2, and these laser beams LB _{1 to} LB ₅ are transmitted to the imaging optical system 41. Tracks 17, 17 on optical disk 8 via
On the tracks 17, 17,.
Along and forms a beam spot BS ₁ to BS _5.

Incidentally, the beam spot BS ₁ to BS ₅ for focusing on the optical disc 8, when the interval between adjacent tracks is P, is set so that the distance between adjacent spots is (M + 1) P. Moreover, the M multiplex tracks 17, 17,... Formed in a spiral shape on the optical disc 8 as shown in FIG. 5 are arranged such that the interval between the tracks 17 is MP.

Therefore, in the initial state, the five beam spots BS _{1 to} BS ₅ are arranged such that the first beam spot BS ₁ is located on the first set of tracks A as shown in FIG. Beam spot BS ₂ on the second track B, third beam spot BS ₃ on the third track C, fourth beam spot BS ₄ on the fourth track D, and the fifth beam The spot BS ₅ is imaged on each of the fifth set of tracks E. Here, A, B, C, D, and E indicate five multiplex tracks in order. In addition, optical disk 8
Has five multiplex tracks 17, 17,..., So that tracks A, B, C, D, and E are arranged in order.

Next, the directly following are allowed to tracking operation the central beam spot BS ₃ in this state into the track C, and the optical disc 8 rotated once, as shown in FIG. 11 (2), the first beam the track a spot BS1 are second set, the second beam spot BS ₂ is third set track B, and the track C of the third beam spot BS ₃ is 4th group, the fourth beam spot BS ₄ There the track D of 5 pair in the fifth beam spot BS ₅ are respectively imaged on 6 pair in the track E.

Similarly, each time the optical disk 8 makes one rotation, the state changes as shown in FIGS. 11 (3) to (5). When the optical disk 8 makes five rotations, the state shown in FIG. 11 (6) is obtained. Eleventh
This is the same as the state shown in FIG.

Thus, the five beam spot rows from the optical head 40
BS ₁ a to BS _5, arranged along a direction perpendicular the track 17, 17 ... and on the optical disc 8, the beam spots BS ₁ .about.B
Even if the S ₅ was positioned on all tracks 17, 17 ... top without being affected by the track 17, 17 ... curvature, it is possible to increase the spacing between adjacent spots BS ₁ to BS ₅ and 9.6μm it can. Further, the interval (M + 1) P of adjacent spots BS ₁ to BS _5, the spacing of one track are arranged such that the MP, the spot BS ₁ to BS ₅ adjacent,
As shown in FIGS. 11 (1) to (6), all of the five multiplex tracks 17, 17,... Are located on adjacent tracks A, B, C, D, E. Therefore, one beam spot is
Just continue to track this track 17, five beam spots BS ₁ to BS ₅ with five multitrack 17 ...
Can record or reproduce information, and does not require a complicated track jump operation. Therefore, a simple control circuit for controlling the tracking operation can be used, which leads to an increase in cost. Absent.

FIG. 12 shows another embodiment of the present invention. The same parts as those of the above embodiment are denoted by the same reference numerals. In this embodiment, of the multiple tracks of the optical disc 8, Only one track A has a pre-group 17a, and the other tracks B, C, D and E are formed on lands 17b. In addition, the above pre-group 17a
The tracking is performed by the track A having the following.

The track A having the pre-group 17a is
For example, it is composed of ROM, phase grooves, light and shade with different reflectivities, and the like.

Tracks B, C, D, and E other than the tracking error signal detection track A have, for example, a groove depth of λ / 4n (where λ is the light beam wavelength, and n is an optical recording medium). (Refractive index of the substrate).
In such a case, the information recorded on the tracks B, C, D, and E can be reproduced with high accuracy.

The tracking error signal detection track A
Is set, for example, so that the depth of the groove is λ / 8n (where λ is the wavelength of the light beam, and n is the refractive index of the substrate of the optical recording medium). In such a case, the tracking error signal can be detected with high accuracy.

Other configurations and operations are the same as those of the above-described embodiment, and the description thereof will be omitted.

FIG. 13 shows an embodiment of the invention described in claim 4. The same parts as those in the above embodiment are denoted by the same reference numerals and described. The described invention relates to an optical head having an imaging optical system for irradiating an array of M beam spots on an optical recording medium, (M-2) multiple tracks and one tracking error signal detection track. An optical information recording / reproducing apparatus comprising: an optical recording medium having a spiral shape; and an optical information recording / reproducing apparatus for optically recording / reproducing information on the optical recording medium by an optical head. The beam spot array is arranged on the optical recording medium along the direction perpendicular to the track, and when the interval between adjacent tracks is P, the interval between adjacent spots excluding beam spots at both ends is MP and One tiger The arrangement is such that the intervals of the tracks are (M-1) P, and the tracking error signal is detected at the spots at both ends of the beam spot row.

That is, as shown in FIG.
It has multiple tracks B, C, D, and E and one track A for tracking error signal detection in a spiral shape. This tracking error signal detection track A
Has a pre-group 17a.

Further, M (six in the illustrated example) spot rows BS _{1 to} BS ₆ are placed on the optical disk 8 by the tracks A,
When arranged along a direction orthogonal to B, C, D, and E, and the interval between adjacent tracks is P, the interval between adjacent spots excluding beam spots at both ends is MP, 1
Spacing of tracks are arranged so that the (M-1) P, thereby performing the detection of the tracking error signal by spots BS ₁ and BS ₆ at both ends of the beam spot line. At that time, the beam spot BS ₁ and BS ₆ at both ends are staggered in a direction away respectively in a direction perpendicular to the track. Spots BS ₁ and BS _{6 at} both ends
Is set to, for example, about half of the interval P between adjacent tracks.

In this case, the reflected light from the spot BS ₁ and BS ₆ at both ends is received by the respective light receiving elements, by an output signal from each light receiving element is amplified by the differential amplifier, the tracking error signal is obtained.

As described above, when the track A for detecting the tracking error signal is provided on the optical disk 8, there is an effect that the tracking error signal can be reliably detected. When the displacement between the spots BS ₁ and BS ₆ at both ends is set to about half of the interval P between the adjacent tracks, the tracking error signal becomes the depth of the pre-group 17 a of the track A for detecting the tracking error signal. , The tracking error signal can be detected with higher accuracy.

Other configurations and operations are the same as those of the above-described embodiment, and the description thereof will be omitted.

FIG. 14 shows another embodiment of the present invention. The same parts as those of the above embodiment are denoted by the same reference numerals and described. In this embodiment, the beam spots BS _{1 at} both ends are provided.
The and BS _6, rather than staggered in a direction away respectively in a direction perpendicular to the track, the beam spot BS ₁ and BS ₆ at both ends, in the direction of approaching each in a direction perpendicular to the track It is configured to be staggered. Further, the deviation amount of the spot BS ₁ and BS ₆ in the both ends in this embodiment, for example, is set to about half the spacing P of adjacent tracks.

[Effects of the Invention] The present invention has the above-described configuration and operation, and forms a plurality of beam spots at predetermined intervals corresponding to a plurality of track intervals along a direction orthogonal to the tracks of the optical recording medium. The distance between the laser diodes arranged in the laser diode array is set widely so that the production of the laser diode array is practically possible, and all the beam spots are simultaneously
Provided is an optical information recording / reproducing apparatus which can avoid a significant increase in cost without using a circuit for performing complicated tracking control even when accurate tracking can be performed on each track. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a positional relationship between a beam spot and a track showing an embodiment of an optical information recording / reproducing apparatus according to the present invention, and FIGS. 2 and 3 are configuration diagrams of the optical information recording / reproducing apparatus. FIG. 4 is a configuration diagram of an imaging optical system, FIGS. 5 (a) and 5 (b) are schematic plan views and partial cross-sectional views respectively showing an optical disk, and FIG. FIG. 7 is a circuit diagram showing a detection unit for a tracking error signal and a focusing error signal, FIG. 8 is a perspective view showing a principle of detecting a focusing error signal,
9 (a), 9 (b) and 9 (c) are explanatory views showing the operation of detecting a focusing error signal, FIG. 10 is a perspective view showing a semiconductor laser, and FIGS. 11 (1) to 11 (6) are multi-elements. Plane explanatory view showing the beam imaging state, FIG. 12 (1)-
(6) is an explanatory plan view showing an image forming state of a multi-beam according to another embodiment of the present invention. FIGS. 13 (1) to (6) are image forming states of a multi-beam according to another embodiment of the present invention. FIGS. 14 (1) to (6) are plan explanatory views showing an image forming state of a multi-beam according to another embodiment of the other invention.
FIG. 15 is a perspective view showing a conventional multi-beam optical head, and FIG.
FIG. 16 is a plan view showing a beam imaged by the multi-beam optical head, FIG. 17 is an explanatory view showing how to form different images of the multi-beam, and FIG. 18 is a diagram showing different images of the multi-beam. FIG. 19 is an explanatory diagram showing how to form a different image of a multi-beam, and FIGS. 20 (1) to (6) are explanatory diagrams showing a state of multi-beam tracking. . [Explanation of Reference Codes] 8 optical disk 17 track 18 semiconductor laser element 40 multi-beam optical head 41 imaging optical system LB laser beam BS beam spot M beam spot Number P: interval between adjacent tracks

Claims (5)

(57) [Claims] 1. An optical head comprising: an optical head having an imaging optical system for irradiating an array of M beam spots onto an optical recording medium; and an optical recording medium having M multiple tracks in a spiral form. An optical information recording / reproducing apparatus for optically recording / reproducing information on an optical recording medium by an optical head, wherein the M beam spot trains from the optical head are orthogonal to the tracks on the optical recording medium. Are arranged along the direction, and when the interval between adjacent tracks is P, the interval between adjacent spots is (M + 1) P and the interval between one track is MP. Optical information recording and reproducing device. 2. The multiplexed track of the optical recording medium, wherein the depth of the groove of a track other than the track for detecting a tracking error signal is λ / 4n (where λ is the wavelength of the light beam, and n is the optical 2. The optical information recording / reproducing apparatus according to claim 1, wherein a refractive index of the substrate of the recording medium is used. 3. The multiplexed track of the optical recording medium, wherein the depth of the groove of the tracking error signal detecting track is λ / 8n (where λ is the wavelength of the light beam and n is the optical recording medium). 2. The optical information recording / reproducing apparatus according to claim 1, wherein the refractive index of the substrate is a refractive index of the substrate. 4. An optical head having an imaging optical system for irradiating an array of M beam spots on an optical recording medium;
2) An optical recording medium having spiral tracks of multiple tracks and one tracking error signal detection track, and optically recording and reproducing information on the optical recording medium by an optical head. Information recording / reproducing apparatus, wherein M beam spot arrays from the optical head are arranged on an optical recording medium along a direction orthogonal to the track, and an interval between adjacent tracks is P. In this case, the interval between adjacent spots excluding the beam spots at both ends is MP, and the interval between one track is (M-1) P
An optical information recording / reproducing apparatus characterized in that tracking error signals are detected at spots at both ends of a beam spot row. 5. The optical information recording / reproducing apparatus according to claim 4, wherein the spots at both ends of the beam spot row are shifted with respect to the track in a direction orthogonal to different tracks.