Optical head torquer, optical head, optical reading and writing system, and data reading and writing method

Abstract

The present application relates to the field of optical technology, and specifically to an optical head torquer, an optical head, an optical reading and writing system, and a data reading and writing method. The optical head torquer includes: a driving unit, an objective lens holder, and a plurality of objective lenses mounted on the objective lens holder; the driving unit is used to drive the objective lens holder to move so that the plurality of objective lenses focus the laser beam onto the disk; the plurality of objective lenses include a main beam objective lens and a servo beam objective lens arranged in parallel along the suspension line direction, the suspension line direction is parallel to the tangential direction of the disk, the main beam objective lens is used to focus the main beam onto the disk, and the servo beam objective lens is used to focus the servo beam onto the disk. The torquer of the present application can increase the effective reading and writing area of the optical head, improve the data reading and writing effect of the optical head, and achieve high-quality reading and writing.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to an optical head torquer, an optical head, an optical reading and writing system, and a data reading and writing method. Background Art

[0002] With the development of mobile devices, the amount of data generated in our daily lives is also exploding. Jem Gray, the 1998 Turing Award winner, proposed a new Moore's Law: the amount of data generated by all computing devices worldwide will grow every 18 months at a rate equal to the total amount of information ever generated. The vast majority of this data is infrequently used, cold data. Therefore, the development of low-energy, long-life, and high-capacity cold data storage technology is urgent. Traditional optical storage, with its low cost, low energy consumption, and long life, has become a key means of cold data storage. In recent years, the emergence of multi-layer high-density optical discs has addressed the low capacity issues of traditional optical storage. The torquer in the optical pickup head of multi-layer high-density optical discs is one of their core technologies.

[0003] In optical disc systems, the torquer is the actual actuator of the optical head's servo action. Its function is to drive the objective lens in real time based on error signals (such as focusing error and tracking error signals) acquired by the optical head during disc reading, allowing the focused light spot to overcome the disc's fluctuations and offsets (for example, offsets in the focusing and tracking directions) on the disc, thereby accurately landing on the disc's information track. However, the two objective lenses of existing optical heads are arranged along the tracking direction, resulting in poor data reading and writing performance. Summary of the Invention

[0004] The embodiments of the present application provide an optical head torquer, which can increase the effective reading and writing area of the optical head and improve the data reading and writing effect of the optical head.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, the present application provides an optical head torquer, comprising: a drive unit, an objective lens holder, and a plurality of objective lenses mounted on the objective lens holder. The drive unit is configured to drive the objective lens holder to move so that the plurality of objective lenses focus a laser beam onto a disk; the plurality of objective lenses include a main beam objective lens and a servo beam objective lens arranged in parallel along a suspension line direction, the suspension line direction being parallel to a tangential direction of the disk; the main beam objective lens is configured to focus a main beam onto the disk, and the servo beam objective lens is configured to focus a servo beam onto the disk.

[0007] According to the optical head torquer provided in the embodiment of the present application, since the main beam objective lens and the servo beam objective lens are arranged side by side along the suspension line direction, and the suspension line direction is perpendicular to the tracking direction of the optical head torquer, the servo beam of the servo beam objective lens and the main beam of the main beam objective lens can be focused on the same readable and writable track circumference of the disk at the same time. However, in the optical head torquer in the prior art, the servo beam of the servo beam objective lens and the main beam of the main beam objective lens will not be focused on the same readable and writable track circumference of the disk at the same time. Therefore, compared with the optical head torquer in the prior art, the optical head torquer provided in the present application, in some possible embodiments, the focusing spot corresponding to the servo beam and the focusing spot corresponding to the main beam can be moved to the edge of the disk at the same time along the tracking direction, that is, the focusing spot corresponding to the servo beam and the focusing spot corresponding to the main beam can be located at the edge of the disk at the same time (corresponding to the maximum readable and writable track circumference of the disk). As a result, the main beam of the main beam objective lens can perform reading and writing operations in all areas on the disk, which greatly improves the effective reading and writing area of the optical head on the disk, achieving high-quality reading and writing.

[0008] In one possible implementation of the first aspect, the main beam objective lens and the servo beam objective lens are arranged so that the main beam and the servo beam can be simultaneously focused on the circumference of the maximum read / write track on the disk, where the radius of the circumference of the maximum read / write track is equal to the radius of the disk. With this arrangement, the main beam and the servo beam can be simultaneously focused on the circumference R1 of the maximum read / write track on the disk, significantly increasing the effective read / write area of the disk.

[0009] In one possible implementation of the first aspect, the drive unit is configured to drive the objective lens holder to move in a focusing direction, a tracking direction, and a tilting direction, wherein the focusing direction is a direction perpendicular to the surface of the disk, the tracking direction is a direction parallel to the radial direction of the disk, and the tilting direction is a direction rotating about a direction parallel to the tangential direction of the disk. In other words, the optical head torquer of the present application is a three-dimensional torquer.

[0010] In a possible implementation of the first aspect, the driving unit includes:

[0011] A tilt drive magnetic circuit, used for providing a Lorentz force for driving the objective lens holder to move in a tilt direction;

[0012] A focusing drive magnetic circuit is used to provide a Lorentz force to drive the objective lens holder to move in the focusing direction;

[0013] The tracking drive magnetic circuit is used to provide the Lorentz force that drives the objective lens holder to move along the tracking direction.

[0014] In a possible implementation of the first aspect above, the tilt drive magnetic circuit includes: a first tilt coil and a second tilt coil;

[0015] The objective lens holder includes a first groove and a second groove arranged on both sides of the multiple objective lenses along the tracking direction. The first groove and the second groove respectively penetrate the objective lens holder along the focusing direction. The first tilt coil is arranged in the first groove and the second tilt coil is arranged in the second groove.

[0016] In one possible implementation of the first aspect, the first tilt coil is disposed on the wall of the first slot facing the multiple objective lenses, and the second tilt coil is disposed on the wall of the second slot facing the multiple objective lenses. With this arrangement, the first and second tilt coils are located on opposite sides of the optical head torquer along the radial direction of the disk. This is an appropriate distance considering the tilt sensitivity, overall size, and mass of the optical head torquer.

[0017] In a possible implementation of the first aspect, the tilt drive magnetic circuit further includes:

[0018] a first yoke, a portion of the first yoke extending in the focusing direction and inserted into the first slot, and a portion of the first yoke spaced from the first tilt coil in the tracking direction;

[0019] The second yoke has a portion extending in the focusing direction and inserted into the second groove, and a portion of the second yoke is spaced apart from the second tilt coil in the tracking direction.

[0020] In a possible implementation of the first aspect, the tilt drive magnetic circuit further includes:

[0021] A first side magnet and a second side magnet, the N pole and S pole of each side magnet are arranged along the focusing direction, the first side magnet is arranged on a surface of a part of the first yoke facing the first tilt coil, and the second side magnet is arranged on a surface of a part of the second yoke facing the second tilt coil.

[0022] In a possible implementation of the first aspect above, the focus drive magnetic circuit includes: a first focus coil and a second focus coil;

[0023] The objective lens holder also includes a third groove and a fourth groove arranged on both sides of the objective lens along the suspension line direction. The third groove and the fourth groove respectively pass through the objective lens holder along the focusing direction. The first focusing coil is arranged in the third groove and the second focusing coil is arranged in the fourth groove.

[0024] In a possible implementation of the first aspect, the focus drive magnetic circuit further includes:

[0025] a third yoke, wherein a first portion of the third yoke extends along the focusing direction and is inserted into the third groove, and the first focusing coil is disposed around the first portion of the third yoke;

[0026] A fourth yoke, wherein a first portion of the fourth yoke extends along a focusing direction and is inserted into the fourth slot, and a second focusing coil is arranged around the first portion of the fourth yoke.

[0027] In a possible implementation of the first aspect, the third yoke further includes a second portion located outside the objective lens holder, the second portion of the third yoke extending along the focusing direction and spaced apart from the first portion of the third yoke along the suspension line direction.

[0028] The fourth yoke further includes a second portion located outside the objective lens holder, the second portion of the fourth yoke extending along the focusing direction and spaced apart from the first portion of the fourth yoke along the suspension line direction;

[0029] The focusing drive magnetic circuit also includes: a first main magnet and a second main magnet, the N pole and S pole of each main magnet are arranged along the suspension line direction, the first main magnet is arranged on the surface of the second part of the third yoke facing the objective lens frame, and the second main magnet is arranged on the surface of the second part of the fourth yoke facing the objective lens frame.

[0030] In a possible implementation of the first aspect above, the surfaces of the objective lens holder facing the third yoke and the fourth yoke are respectively provided with a first mounting groove and a second mounting groove that penetrate the surface along the suspension line direction, the first mounting groove is for the first focusing coil to pass through to be arranged in the third groove, and the second mounting groove is for the second focusing coil to pass through to be arranged in the fourth groove.

[0031] In a possible implementation of the first aspect, the tracking drive magnetic circuit includes:

[0032] Two pairs of tracking coils are located on the outer surface of the lens holder, one pair of tracking coils is located on the outer surface of the lens holder facing the first main magnet, and the other pair of tracking coils is located on the outer surface of the lens holder facing the second main magnet.

[0033] In one possible implementation of the first aspect, the outer contour of the projection of the objective lens holder along the focusing direction is octagonal. This configuration prevents interference between the suspension wire and the objective lens holder during movement in the focusing, tracking, and tilting directions, thereby affecting movement of the objective lens holder. Furthermore, since the objective lens holder does not interfere with the suspension wire during movement, the service life of the suspension wire can be extended.

[0034] In a possible implementation of the first aspect above, the octagon is a regular octagon.

[0035] In a possible implementation of the first aspect, the method further includes:

[0036] Terminal block;

[0037] At least eight suspension wires extend along a suspension direction, one end of the at least eight suspension wires is connected to the wiring seat, and the other end is connected to the objective lens holder to support the objective lens holder;

[0038] Six of the at least eight suspension wires are used to supply current to the coils in the focus drive magnetic circuit, the tracking drive magnetic circuit, and the tilt drive magnetic circuit, respectively. This application does not impose a limit on the number of suspension wires; any number of suspension wires sufficient to support the objective lens holder and supply current to the drive magnetic circuits falls within the scope of protection of this application. For example, in some possible implementations, the number of suspension wires is ten.

[0039] In a second aspect, the present application provides an optical head, comprising:

[0040] The optical head torque device as described in any one of the first aspects above, wherein the optical head torque device is used for reading and writing a disk; and

[0041] The light source is used to emit a main beam and a servo beam. The main beam objective lens is used to focus the main beam onto the disk. The servo beam objective lens is used to focus the servo beam onto the disk.

[0042] In a third aspect, the present application provides an optical reading and writing system, comprising:

[0043] A disk table, used to mount the disk and drive the disk to rotate; and

[0044] The optical head described in the second aspect above.

[0045] In a possible implementation of the second aspect, the optical reading and writing system further includes:

[0046] The controller is used to control the rotation of the disk table and control the driving unit to drive the objective lens holder to move in the focusing direction, tracking direction and tilt direction.

[0047] In a fourth aspect, a data writing method using the optical reading and writing system according to any one of the third aspects is provided, the method comprising:

[0048] detecting that the main beam and the servo beam are focused on the disk;

[0049] Drive the platter to rotate;

[0050] acquiring a first guidance signal according to the servo beam, and driving the objective lens holder to move along the tracking direction according to the first guidance signal;

[0051] Acquire a first error signal according to the servo beam, the first error signal including a focus error signal, a tracking error signal, and a tilt error signal;

[0052] According to the first error signal, the objective lens holder is driven to move in the focusing direction, the tracking direction and the tilting direction;

[0053] Determining that the wavefront aberration of the writing spot of the main beam is within a preset range;

[0054] A second pilot signal is acquired according to the servo beam, and the main beam writes data information on the recording layer according to the second pilot signal.

[0055] In a fifth aspect, a data reading method using the optical reading / writing system according to any one of the third aspects is provided, the method comprising:

[0056] It is detected that the main beam is focused on the disc;

[0057] Drive the platter to rotate;

[0058] obtaining a third guiding signal according to the main light beam, and driving the objective lens holder to move along the tracking direction according to the third guiding signal;

[0059] Acquire a second error signal according to the main light beam, the second error signal including a focus error signal, a tracking error signal and a tilt error signal;

[0060] driving the objective lens holder to move in a focusing direction, a tracking direction, and a tilting direction according to the second error signal;

[0061] Determining that the wavefront aberration of the reading spot of the main beam is within a preset range;

[0062] A fourth pilot signal is obtained according to the main light beam, and the main light beam reads data information in the recording layer according to the fourth pilot signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 Schematic diagram showing the structure of the optical reading and writing system of some embodiments of the present application Figure 1 ;

[0064] Figure 2 Schematic diagram showing the structure of the optical reading and writing system of some embodiments of the present application Figure 2 ;

[0065] Figure 3 3D diagram showing the torquer in the optical reading and writing system of some embodiments of the present application Figure 1 ;

[0066] Figure 4 Schematic diagram showing the structure of the optical reading and writing system of some embodiments of the present application Figure 3 ;

[0067] Figure 5 Schematic diagram showing the structure of the optical reading and writing system of some embodiments of the present application Figure 4 ;

[0068] Figure 6 A perspective view showing a driving unit in an optical reading and writing system according to some embodiments of the present application;

[0069] Figure 7 A perspective exploded view of a torquer in an optical reading and writing system according to some embodiments of the present application is shown;

[0070] Figure 8 3D diagram showing the torquer in the optical reading and writing system of some embodiments of the present application Figure 2 ;

[0071] Figure 9 A top view of a torquer in an optical reading and writing system according to some embodiments of the present application is shown;

[0072] Figure 10 A cross-sectional view of a torquer in an optical reading and writing system according to some embodiments of the present application is shown. Figure 1 ;

[0073] Figure 11 A cross-sectional view of a torquer in an optical reading and writing system according to some embodiments of the present application is shown. Figure 2 ;

[0074] Figure 12 Schematic diagram showing the magnetic circuit in the optical reading and writing system of some embodiments of the present application Figure 1 ;

[0075] Figure 13 Schematic diagram showing the magnetic circuit in the optical reading and writing system of some embodiments of the present application Figure 2 ;

[0076] Figure 14 A flow chart showing a data writing method of an optical reading and writing system according to some embodiments of the present application;

[0077] Figure 15 A flow chart showing a data reading method of an optical reading / writing system according to some embodiments of the present application is shown. DETAILED DESCRIPTION

[0078] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0079] In some possible implementations, reference Figure 1 The optical reading and writing system includes: a disk 1 (for example, an optical disc) and an optical head torque device. The disk 1 is mounted on the disk table and is driven to rotate by the spindle motor 2 ( Figure 1 (T in the figure indicates the direction of rotation). The torquer is a core component of the optical read / write system. It can adjust the spatial position and posture of the objective lens in real time to ensure that the focused light spot passing through the torquer objective lens always accurately lands on the information track of the information storage disk 1 to enable data reading and writing.

[0080] The optical head torquer of the present application includes a driving unit (not shown), an objective lens holder 3 and a plurality of objective lenses mounted on the objective lens holder 3. The driving unit is used to drive the objective lens holder 3 to move, for example, along the focusing direction ( Figure 1The laser beam is focused onto the disk 1 in the Z direction (shown in FIG. 1 ). The focusing direction is perpendicular to the surface of the disk 1.

[0081] In this application, if Figure 1 As shown, the multiple objective lenses include a main beam objective lens 3a and a servo beam objective lens 3b, and the main beam objective lens 3a and the servo beam objective lens 3b are arranged along the tracking direction, which is along the radial direction of the parallel disk 1 ( Figure 1 and Figure 2 The radial direction of the disk 1 is perpendicular to the tangential direction of the disk 1 ( Figure 2 The main beam objective lens 3a is used to focus the main beam onto the disk 1 ( Figure 1 and Figure 2 Point A in the middle is the focus spot of the main beam on the disk 1), and the servo beam objective lens 3b is used to focus the servo beam onto the disk 1 ( Figure 1 and Figure 2 Point B in the middle is the focused spot of the main beam on the disk 1). For example, Figure 1 As shown in FIG, along the tracking direction, the main beam objective lens 3a is located on the left side of the servo beam objective lens 3b.

[0082] Exemplarily, the above-mentioned main beam objective lens 3a and servo beam objective lens 3b are compatible with DVD (Digital Video Disc) and BD (Blu-ray Disc). One of the objective lenses is used to realize the CD / DVD function, and the other objective lens realizes the Blu-ray reading function, which can meet the reading and writing of DVD at high speed and the burning function of Blu-ray.

[0083] When the main beam objective lens 3a and the servo beam objective lens 3b are arranged along the tracking direction (i.e., arranged along the radial direction of the disk 1), taking the optical read-write system as an example of writing information, the main beam objective lens 3a and the servo beam objective lens 3b will work simultaneously. Figure 2 , when the driving unit drives the objective lens frame 3 to move rightward along the tracking direction ( Figure 2 (Direction E in the figure indicates the movement direction). The main beam objective lens 3a and the servo beam objective lens 3b also move rightward along the tracking direction. Accordingly, the focused spot A of the main beam of the main beam objective lens 3a on the disk 1 moves rightward relative to the center point O of the disk 1, and the focused spot B of the servo beam of the servo beam objective lens 3b on the disk 1 moves rightward relative to the center point O of the disk 1.

[0084] The main beam of the main beam objective lens 3a and the servo beam of the servo beam objective lens 3b will not be focused on the same readable and writable track circle of the disk 1 at the same time. Figure 2As shown in (a), the main beam of the main beam objective lens 3a is focused on the circumference O1 of the readable and writable track of the disk 1, and the servo beam of the servo beam objective lens 3b is focused on the circumference O2 of the readable and writable track of the disk 1. Exemplarily, the radius of the circumference O2 of the readable and writable track is larger than the radius of the circumference O1 of the readable and writable track.

[0085] Since the optical reading and writing system writes information layer by layer, each layer will be offset outward from the radius of the previous layer. Figure 2 As shown in (a), when the servo beam of the servo beam objective lens 3b can still focus on the disc 1, that is, when there is still a focused spot B on the disc 1, the main beam objective lens 3a can perform writing work normally. Figure 2 As shown in (b), when the servo beam objective lens 3b moves to the right along the tracking direction until the servo beam is not focused on the disk 1 (the focused spot A is within the edge of the disk 1), that is, when the focused spot B does not exist on the disk 1, the main beam objective lens 3a stops writing.

[0086] This means that the main beam of the main beam objective lens 3a will not write to all areas on the disc 1, for example Figure 2 (b) shows that the optical head's effective read / write area is S1 (the circumferential area formed by the line connecting the center point O of disk 1 and the focused spot A). The annular area (area S2) formed by the focused spot A and the edge of disk 1 is where the main beam cannot write. The sum of areas S1 and S2 is the circumferential area of disk 1. Consequently, the optical head's effective read / write area on the entire disk 1 is reduced.

[0087] To this end, in some possible implementations, reference Figure 3 and Figure 4 , the present application provides another optical reading and writing system, which can increase the effective reading and writing area of the optical head on the disk 20. The optical reading and writing system includes an optical head torquer 10, a disk 20 and an optical path system 30. Exemplarily, the optical head torquer 10 and the optical path system 30 constitute a part of the structure of the optical head. The optical head torquer 10 of the present application includes: an objective lens holder 11, a driving unit 12, a plurality of objective lenses mounted on the objective lens holder 11, a plurality of suspension wires 13 and a terminal block 14. Among them, the driving unit 12 and the terminal block 14 are non-movable parts of the optical head torquer 10, and the objective lens holder 11, the plurality of objective lenses and the suspension wires 13 are movable parts of the optical head torquer 10.

[0088] The extension direction of each suspension line 13 is the suspension line direction ( Figure 3 The direction of the suspension line is parallel to the tangent direction of the disk 20 ( Figure 5The tangent direction of the disk 20 is perpendicular to the radial direction of the disk 20. Along the suspension wire direction, one end of each suspension wire 13 is connected to the wiring seat 14, and the other end is connected to the objective lens holder 11 to support the objective lens holder 11. Exemplarily, the above-mentioned wiring seat 14 is a circuit board. Part of the suspension wire 13 is used to provide current to the driving unit 12, so that the driving unit 12 can drive the objective lens holder 11 to move, so that the multiple objective lenses focus the laser beam onto the disk 20. The multiple objective lenses also include a main beam objective lens 111 and a servo beam objective lens 112. The optical path system 30 provides a main beam 31 and a servo beam 32 to the optical head torquer 10, and the main beam 31 is focused on the disk 20 through the main beam objective lens 111 ( Figure 4 Point C is the focus spot of the main beam 31 on the disk 20), and the servo beam 32 is focused on the disk 20 through the servo beam objective lens 112 ( Figure 4 Point D is the focused spot of the main light beam 31 on the disk 20).

[0089] The difference from the above embodiment is that Figures 3 to 5 The main beam objective lens 111 and the servo beam objective lens 112 in the optical head torquer 10 are arranged along the suspension line direction ( Figures 3 to 5 The Y direction is shown in the figure) and the suspension line direction is parallel to the tangent direction of the disk 20 ( Figure 5 The tangent direction of the disk 20 is perpendicular to the radial direction of the disk 20. That is, the main beam objective lens 111 and the servo beam objective lens 112 of the present application are not arranged along the tracking direction, that is, not arranged along the radial direction of the disk 20. This is equivalent to, Figures 3 to 5 The arrangement direction of the double objective lens shown is perpendicular to Figure 1 and Figure 2 The arrangement direction of the dual objective lenses shown.

[0090] Since the main beam objective lens 111 and the servo beam objective lens 112 are arranged in parallel along the suspension line direction, the servo beam of the servo beam objective lens 112 and the main beam of the main beam objective lens 111 can be simultaneously focused on the same readable and writable track circumference of the disk 20 (for example Figure 5 On the readable and writable track circle O3) shown in (a).

[0091] After setting this up, for example, refer to Figure 5 In (a), the driving unit 12 drives the objective lens frame 11 to move rightward along the tracking direction ( Figure 5(Direction E in the figure indicates the movement direction), the main beam objective lens 111 and the servo beam objective lens 112 also move rightward along the tracking direction and onto the same circumference of the read / write track on the disk 20. Accordingly, the focused spot C of the main beam 31 of the main beam objective lens 111 on the disk 20 moves rightward relative to the center point O of the disk 20, and the focused spot D of the servo beam 32 of the servo beam objective lens 112 on the disk 20 moves rightward relative to the center point O of the disk 20. In other words, the focused spot C and the focused spot D can exist simultaneously on the same circumference of the read / write track on the disk 20.

[0092] Thus, reference Figure 5 In (b), the focused spot C and the focused spot D can simultaneously move to the right along the tracking direction to the edge of the disk 20 (corresponding to the maximum readable and writable track circumference of the disk 20). Then, the main beam 31 of the main beam objective lens 111 can write to all areas on the disk 20. For example Figure 5 (b) shows that the effective reading and writing area of the optical head is S3 ( Figure 2 =The sum of area S1 and area S2). This is equivalent to the arrangement of the main beam objective lens 111 and the servo beam objective lens 112 satisfying the following conditions: the main beam 31 and the servo beam 32 can be simultaneously focused on the maximum readable and writable track circumference R1 of the disk 20, wherein the radius of the maximum readable and writable track circumference R1 is equal to the radius of the disk 20. Figure 2 Compared with the arrangement positions of the main beam objective lens 111 and the servo beam objective lens 112 shown in FIG. Figures 3 to 5 The arrangement of the main beam objective lens 111 and the servo beam objective lens 112 shown greatly increases the effective reading and writing area of the optical head on the disk 20 .

[0093] For example, refer to Figure 3 、 Figures 6 to 9 The diameter of the suspension wire 13 is 0.15 mm and the density is 8660 kg / m 3 , Poisson's ratio is 159GPa, and there are eight of them. For example, Figure 3 As shown, four suspension wires 13 are provided on either side of the tracking direction of the objective lens holder 11. One end of each suspension wire 13 is fixed to a terminal block 14, and the other end is inserted into the fixing ears 118 (a total of eight) on both sides of the objective lens holder 11. Each suspension wire 13 passes through two fixing ears 118 and is bonded and cured thereto. Any two of the suspension wires 13 serve as support and do not need to be welded to the leads of the coils (the focusing coil, tracking coil, and tilt coil described later) in the drive unit 12. The remaining six suspension wires 13 are welded to the leads of the corresponding coils to provide support force and current for the entire optical head torquer 10.

[0094] As the capacity of the disk 20 increases, the tilt tolerance of the disk 20 becomes smaller and smaller. Figure 3 and Figure 4The driving unit 12 of the present application is used to drive the objective lens holder 11 along the focusing direction ( Figure 3 and Figure 4 Z direction), tracking direction ( Figure 3 and Figure 4 X direction) and tilt direction ( Figure 4 The optical head torquer 10 of the present application is a three-dimensional torquer that can drive the objective lens to perform focusing, tracking, and tilting movements.

[0095] Therefore, the optical head torquer 10 of the present application can drive the objective lens frame 11 to move in real time according to the error signals obtained by the optical head during the reading process of the disc 20, namely the focusing error signal, the tracking error signal and the tilt error signal, so that the focusing spot C of the main beam objective lens 111 and the focusing spot D of the servo beam objective lens 112 can overcome the offset of the light spot on the disc 20 caused by the ups and downs vibration of the optical disc, and then accurately fall on the information track (wobble layer 22 and recording layer 21) of the disc 20, thereby achieving high-quality reading and writing.

[0096] In some possible implementations, the optical head torquer 10 may be a two-dimensional torquer that can drive the objective lens to perform focusing and tracking motions.

[0097] This application uses the example of a three-dimensional optical head torquer 10. Exemplarily, the drive unit 12 includes a tilt drive magnetic circuit, a focus drive magnetic circuit, and a tracking drive magnetic circuit. The aforementioned suspension wire 13 supplies current to the coils in the focus drive magnetic circuit, the tracking drive magnetic circuit, and the tilt drive magnetic circuit, respectively. Thus, the tilt drive magnetic circuit provides a Lorentz force that drives the objective lens holder 11 in a tilting direction, the focus drive magnetic circuit provides a Lorentz force that drives the objective lens holder 11 in a focusing direction, and the tracking drive magnetic circuit provides a Lorentz force that drives the objective lens holder 11 in a tracking direction.

[0098] For example, refer to Figure 9 The outer contour of the projection of the objective lens holder 11 along the focusing direction is an octagon. For example, the octagon is a regular octagon. This arrangement prevents interference between the suspension wire 13 and the objective lens holder 11 during movement in the focusing, tracking, and tilting directions, thereby affecting the movement of the objective lens holder 11. Furthermore, since the objective lens holder 11 does not interfere with the suspension wire 13 during movement, the service life of the suspension wire 13 can be extended. The specific structures of the aforementioned tilting drive magnetic circuit, focusing drive magnetic circuit, and tracking drive magnetic circuit are not limited. Any structure that can provide the Lorentz force that drives the objective lens holder 11 to perform focusing, tracking, and tilting movements falls within the scope of protection of this application.

[0099] Some possible implementations of the tilting drive magnetic circuit, the focusing drive magnetic circuit, and the tracking drive magnetic circuit are introduced below by way of example.

[0100] In some possible implementations, reference Figure 3 、 Figures 6 to 11 The tilt drive magnetic circuit of the present application includes: a first tilt coil 121 and a second tilt coil 122. For example, the first tilt coil 121 and the second tilt coil 122 are both 0.1 mm in diameter, 2240 Ω / m in resistivity, and 9 turns each. The objective lens holder 11 includes a first tilt coil 121 and a second tilt coil 122. Figure 7 The first groove 113 and the second groove 114 are provided on both sides of the plurality of objective lenses (shown in the X direction), and the first groove 113 and the second groove 114 are located between the suspension wires 13 on both sides of the objective lens holder 11. The first groove 113 and the second groove 114 of the present application are respectively along the focusing direction ( Figure 7 The first slot 113 extends through the objective lens holder 11 (as shown in the Z direction). That is, along the focusing direction, the top and bottom of the first slot 113 are continuous, and the top and bottom of the second slot 114 are continuous. The first tilt coil 121 of the present application is disposed within the first slot 113, and the second tilt coil 122 is disposed within the second slot 114.

[0101] The first groove 113 of the present application includes a left groove wall 1131 and a right groove wall 1132 arranged opposite each other along the tracking direction, with the left groove wall 1131 of the first groove 113 facing the main beam objective lens 111 and the servo beam objective lens 112. The second groove 114 includes a left groove wall 1142 and a right groove wall 1141 arranged opposite each other along the tracking direction, with the right groove wall 1141 of the second groove 114 facing the main beam objective lens 111 and the servo beam objective lens 112.

[0102] For example, the maximum current flowing through the first and second tilt coils 121, 122 is 0.3A. When the number of turns in the first and second tilt coils 121, 122 is too large, the Lorentz force increases, and the resistance of the first and second tilt coils 121, 122 increases, reducing the tilt sensitivity of the optical head torquer 10. Excessive mass can also cause the optical head torquer 10 to sag significantly due to gravity when de-energized. When the number of turns in the first and second tilt coils 121, 122 is determined, the greater the distance between the first and second tilt coils 121, 122 and the center of mass of the optical head torquer 10, while maintaining the same Lorentz force, the greater the tilt torque generated by the Lorentz force.

[0103] In order to meet the tilt sensitivity required by the design of the optical head torquer 10, the distance between the first tilt coil 121 and the second tilt coil 122 and the center of mass of the optical head torquer 10 should be as large as possible. However, if this distance is too large, the overall volume and mass of the optical head torquer 10 will be too large. Figure 11In some possible implementations, the first tilt coil 121 is disposed on the left groove wall 1131 of the first groove 113 facing the multiple objective lenses, and the second tilt coil 122 is disposed on the right groove wall 1141 of the second groove 114 facing the multiple objective lenses. With this arrangement, the first tilt coil 121 and the second tilt coil 122 are distributed on both sides of the optical head torquer 10 along the radial direction of the disk 20. This is an appropriate distance considering the tilt sensitivity, overall volume, and mass of the optical head torquer 10.

[0104] Continue to refer Figure 6 、 Figure 7 、 Figure 9 and Figure 11 The tilt drive magnetic circuit of the present application further includes: a first yoke 127 and a second yoke 129. Exemplarily, the first yoke 127 and the second yoke 129 are made of a nickel-iron high-permeability magnetic alloy, and are used to regulate the magnetic circuit of the dual-objective-lens three-dimensional torquer of the multi-layer high-density optical disc optical pickup head and prevent magnetic flux leakage.

[0105] Exemplarily, the first yoke 127 includes a first portion 1271, a second portion 1273, and a third portion 1272 connected to each other, wherein the first portion 1271 and the third portion 1272 of the first yoke 127 are respectively aligned along the focusing direction ( Figure 6 、 Figure 7 and Figure 11 The first yoke 127 extends in the Z direction (shown in the middle Z direction), and the second portion 1273 of the first yoke 127 is connected to the bottom of the first portion 1271 and the third portion 1272 of the first yoke 127, respectively. The second portion 1273 of the first yoke 127 is used to mount the first yoke 127 on the base (not shown) of the optical head torquer 10. Exemplarily, the second portion 1273 of the first yoke 127 is bonded and cured to the base of the optical head torquer 10 by glue, and is relatively fixed.

[0106] Exemplarily, the second yoke 129 has the same structure as the first yoke 127. The second yoke 129 includes a first portion 1291, a second portion 1293, and a third portion 1292 connected to each other, wherein the first portion 1291 and the third portion 1292 of the second yoke 129 are respectively along the focusing direction ( Figure 6 、 Figure 7 and Figure 11 The second portion 1293 of the second yoke 129 is connected to the bottom of the first portion 1291 and the third portion 1292 of the second yoke 129, respectively. The second portion 1293 of the second yoke 129 is used to mount the second yoke 129 on the base (not shown) of the optical head torquer 10. Exemplarily, the second portion 1293 of the second yoke 129 is bonded and cured to the base of the optical head torquer 10 by glue and is relatively immovable.

[0107] Since the first groove 113 and the second groove 114 pass through the objective lens holder 11 along the focusing direction, it is convenient for the first portion 1271 of the first yoke 127 to be inserted into the first groove 113 along the focusing direction, and the first portion 1291 of the second yoke 129 to be inserted into the second groove 114 along the focusing direction. Figure 6 、 Figure 7 and Figure 11 The first yoke 127 is spaced apart from the first tilted coil 121 (as shown in the X direction), with the third portion 1272 of the first yoke 127 located outside the first slot 113. The first portion 1291 of the second yoke 129 is spaced apart from the second tilted coil 122 along the tracking direction, with the third portion 1292 of the second yoke 129 located outside the second slot 114. Furthermore, a first side magnet 131 is provided on the surface of the first portion 1271 of the first yoke 127 facing the first tilted coil 121, and a second side magnet 132 is provided on the surface of the first portion 1291 of the second yoke 129 facing the second tilted coil 122.

[0108] like Figure 7 As shown, the N pole and S pole of the first side magnet 131 are arranged up and down along the focusing direction, and the S pole and N pole of the second side magnet 132 are arranged up and down along the focusing direction. Figure 12 and Figure 13 The currents in the first tilt coil 121 and the second tilt coil 122 in the tilt drive magnetic circuit are directed in the same direction. Thus, the tilt drive magnetic circuit of the present application provides a Lorentz force on the objective lens holder 11 that causes it to move in the tilt direction. By changing the direction of the currents in the first tilt coil 121 and the second tilt coil 122, the direction of the Lorentz force applied to the objective lens holder 11 can be changed, thereby controlling the tilt movement of the objective lens holder 11 to accommodate the offset of the disk 20 and achieve high-quality reading and writing.

[0109] It should be noted that the structures of the first yoke 127 and the second yoke 129 are not limited to the above-described structures. Any structure that can regulate the magnetic circuit and support the first side magnet 131 and the second side magnet 132 falls within the scope of protection of this application. For example, in some possible embodiments, the first yoke 127 includes only the above-described first portion, and the second yoke 129 includes only the above-described first portion.

[0110] In some possible implementations, reference Figure 3 、 Figures 6 to 11 The focus driving magnetic circuit of the present application includes: a first focus coil 124 and a second focus coil 123. For example, the first focus coil 124 and the second focus coil 123 are both 0.1 mm in diameter, have a resistivity of 2240 Ω / m, and are both 30 turns. The objective lens holder 11 also includes a suspension line direction ( Figure 7The third groove 115 and the fourth groove 116 are provided on both sides of the objective lens, and the third groove 115 and the fourth groove 116 are respectively along the focusing direction ( Figure 7 The third groove 115 extends through the objective lens holder 11 (as shown in the Z direction). That is, along the focusing direction, the top and bottom of the third groove 115 are continuous, and the top and bottom of the fourth groove 116 are continuous. The first focusing coil 124 is disposed within the third groove 115, and the second focusing coil 123 is disposed within the fourth groove 116.

[0111] Continue to refer Figure 6 、 Figure 7 、 Figure 9 and Figure 10 The focus drive magnetic circuit of the present application further includes: a third yoke 128 and a fourth yoke 130. For example, the third yoke 128 and the fourth yoke 130 are made of nickel-iron high-permeability magnetic alloy, which is a dual-lens three-dimensional torquer for multi-layer high-density optical disc pickup head to regulate the magnetic circuit and prevent magnetic leakage. For example, referring to Figure 3 and Figure 9 The first yoke 127 , the second yoke 129 , the third yoke 128 and the fourth yoke 130 are evenly and symmetrically distributed around the objective lens holder 11 , making the structure of the optical head torquer 10 compact.

[0112] Exemplarily, the third yoke 128 includes a first portion 1281, a second portion 1283, and a third portion 1282 connected to each other, wherein the first portion 1281 and the second portion 1283 of the third yoke 128 are respectively aligned along the focusing direction ( Figure 6 、 Figure 7 、 Figure 9 and Figure 10 The third portion 1282 of the third yoke 128 is connected to the bottom of the first portion 1281 and the second portion 1283 of the third yoke 128, respectively. The third portion 1282 of the third yoke 128 is used to mount the third yoke 128 on the base (not shown) of the optical head torquer 10. Exemplarily, the third portion 1282 of the third yoke 128 is bonded and cured to the base of the optical head torquer 10 by glue, and is relatively immovable.

[0113] Exemplarily, the fourth yoke 130 has the same structure as the third yoke 128. The fourth yoke 130 includes a first portion 1301, a second portion 1303 and a third portion 1302 connected to each other, wherein the first portion 1301 and the second portion 1303 of the fourth yoke 130 are respectively along the focusing direction ( Figure 6 、 Figure 7 、 Figure 9 and Figure 10The third portion 1302 of the fourth yoke 130 is connected to the bottom of the first portion 1301 and the second portion 1303 of the fourth yoke 130, respectively. The third portion 1302 of the fourth yoke 130 is used to mount the fourth yoke 130 on the base (not shown) of the optical head torquer 10. Exemplarily, the third portion 1302 of the fourth yoke 130 is bonded and cured to the base of the optical head torquer 10 by glue, and is relatively immovable.

[0114] Since the third groove 115 and the fourth groove 116 respectively penetrate the objective lens holder 11 along the focusing direction, it is convenient for the first portion 1281 of the third yoke 128 to be inserted into the third groove 115 along the focusing direction, and for the first portion 1301 of the fourth yoke 130 to be inserted into the fourth groove 116 along the focusing direction. Figure 6 The first focusing coil 124 disposed in the third slot 115 is disposed around the first portion 1281 of the third yoke 128, and the second focusing coil 123 disposed in the fourth slot 116 is disposed around the first portion 1301 of the fourth yoke 130. The second portion 1283 of the third yoke 128 is spaced apart from the first portion 1281 of the third yoke 128 along the suspension direction and is located outside the third slot 115. The second portion 1303 of the fourth yoke 130 is spaced apart from the first portion 1301 of the fourth yoke 130 along the suspension direction and is located outside the fourth slot 116.

[0115] In addition, a first main magnet 133 is provided on the surface of the second portion 1283 of the third yoke 128 facing the objective lens holder 11, and a second main magnet 134 is provided on the surface of the second portion 1303 of the fourth yoke 130 facing the objective lens holder 11. In other words, the first main magnet 133 and the second main magnet 134 are provided outside the objective lens holder 11. For example, the north pole and south pole of the first main magnet 133 are arranged along the suspension line direction, and the north pole and south pole of the second main magnet 134 are arranged along the suspension line direction. Figure 12 and Figure 13 The currents flowing through the first focusing coil 124 and the second focusing coil 123 in the focus drive magnetic circuit are directed in the same direction. Thus, the focus drive magnetic circuit of the present application provides a Lorentz force on the objective lens holder 11 that moves in the focus direction. By changing the direction of the current flowing through the first focusing coil 124 and the second focusing coil 123, the direction of the Lorentz force applied to the objective lens holder 11 that moves in the focus direction can be changed, thereby controlling the focusing motion of the objective lens holder 11 to accommodate the offset of the disk 20 and achieve high-quality reading and writing.

[0116] As mentioned above, the first focusing coil 124 is arranged around the first portion 1281 of the third yoke 128, and the second focusing coil 123 is arranged around the first portion 1301 of the fourth yoke 130. In order to facilitate the installation of the first focusing coil 124 and the second focusing coil 123, refer to Figure 8The surfaces of the objective lens holder 11 facing the third yoke 128 and the fourth yoke 130, respectively, are provided with a first mounting groove 117 and a second mounting groove (with the same structure as the first mounting groove 117) extending through the surface in the direction of the suspension line. That is, along the suspension line direction, the third groove 115 communicates with the outside world through the first mounting groove 117, and the fourth groove 116 communicates with the outside world through the second mounting groove. The first mounting groove 117 allows the first focusing coil 124 to pass through and be located within the third groove 115, while the second mounting groove allows the second focusing coil 123 to pass through and be located within the fourth groove 116. Specifically, the first focusing coil 124 passes through the first mounting groove 117 from the side of the objective lens holder 11 and is then located within the third groove 115. The second focusing coil 123 passes through the second mounting groove from the side of the objective lens holder 11 and is then located within the fourth groove 116.

[0117] In some possible implementations, reference Figure 6 、 Figure 7 、 Figure 9 and Figure 10 The tracking drive magnetic circuit includes two pairs of tracking coils 125 and 126 located on the outer surface of the objective lens holder 11. One pair of tracking coils 125 includes a first tracking coil 1251 and a second tracking coil 1252, spaced apart in the tracking direction. The first tracking coil 1251 and the second tracking coil 1252 are located on the outer surface of the objective lens holder 11 facing the first main magnetic field 133. The other pair of tracking coils 126 includes a third tracking coil 1261 and a fourth tracking coil 1262, spaced apart in the tracking direction. The third tracking coil 1261 and the fourth tracking coil 1262 are located on the outer surface of the objective lens holder 11 facing the second main magnetic field 134. Along the suspension line direction, the first tracking coil 1251 and the third tracking coil 1261 are spaced apart, while the second tracking coil 1252 and the fourth tracking coil 1262 are spaced apart. In other words, the two pairs of tracking coils 125 and 126 are located outside the objective lens holder 11.

[0118] For example, the two pairs of tracking coils 125 and 126 have a diameter of 0.1 mm, a resistivity of 2240 Ω / m, and 12 turns. Figure 12 and Figure 13 The currents in the first tracking coil 1251 and the second tracking coil 1252 are in opposite directions, the currents in the first tracking coil 1251 and the third tracking coil 1261 are in opposite directions, the currents in the third tracking coil 1261 and the fourth tracking coil 1262 are in opposite directions, and the currents in the second tracking coil 1252 and the fourth tracking coil 1262 are in opposite directions. Thus, the tracking drive magnetic circuit of the present application provides the objective lens holder 11 with a Lorentz force for movement in the tracking direction. By changing the direction of the currents in the two pairs of tracking coils 125 and 126, the direction of the Lorentz force provided to the objective lens holder 11 for movement in the tracking direction can be changed, thereby controlling the tracking motion of the objective lens holder 11 to adapt to the offset of the disk 20 and achieve high-quality reading and writing.

[0119] Exemplarily, the optical reading and writing system further includes a controller (not shown) for controlling the rotation of the disk table on which the disk 20 is mounted, and controlling the driving unit 12 to drive the objective lens holder 11 to move in the focusing direction, tracking direction and tilt direction.

[0120] In summary, the optical head torquer provided by the present application, by setting the above-mentioned tilt drive magnetic circuit, focus drive magnetic circuit and tracking drive magnetic circuit, enables the dual-objective lens three-dimensional torquer of the present application to have the linear motion freedom in the focusing direction, the linear motion freedom in the tracking direction, and the tilt motion freedom in the tilt direction, thereby ensuring the accuracy of high-density optical disc reading and writing and improving the density of single-layer optical disc information storage. In addition, the dual objective lenses of the optical head torquer of the present application are arranged side by side along the tangential direction of the optical disc, thereby increasing the effective reading and writing area of the optical head torquer 10 on the disc 20. The dual objective lenses can work simultaneously and individually, meeting the reading and writing requirements of multi-layer optical discs with dozens of layers, increasing the storage capacity of the optical disc, and promoting the development of cold data storage technology.

[0121] refer to Figure 4 The information track of the disk 20 of the present application includes a wobble layer 22 (guide layer) and a recording layer 21. In some possible implementations, refer to Figure 14 The present application provides a data writing method using the optical reading and writing system described in any of the above embodiments, specifically writing data to the recording layer 21 of the disk 20.

[0122] Data writing methods include:

[0123] S100: The optical head torquer 10 moves the animal frame 11 along the focusing direction, and both the main beam objective lens 111 and the servo beam objective lens 112 work, so that the main beam 31 and the servo beam 32 are focused on the disk 20;

[0124] S101: When it is detected that the main beam 31 and the servo beam 32 are focused on the disk 20, the controller drives the disk 20 to rotate, obtains a first guidance signal (wobble signal) based on the servo beam 32, and drives the objective lens holder 11 to move in the tracking direction according to the first guidance signal;

[0125] S102: During the movement of the objective lens holder 11 along the tracking direction, the controller obtains a first error signal based on the servo beam 32. The first error signal includes a focus error signal, a tracking error signal, and a tilt error signal. The controller drives the objective lens holder 11 to move along the focus direction, the tracking direction, and the tilt direction based on the first error signal. That is, the optical head torquer 10 drives the main beam objective lens 111 and the servo beam objective lens 112 to vibrate at high frequencies in three degrees of freedom based on the focus signal, the tracking signal, and the tilt signal, so that the main beam 31 and the servo beam 32 are focused on the disk 20 within a certain error range.

[0126] S103 : When the controller determines that the wavefront aberration of the writing spot of the main beam 31 is within a preset range, the controller obtains a second pilot signal according to the servo beam 32 , and the main beam 31 writes data information on the recording layer 21 according to the second pilot signal.

[0127] In some possible implementations, reference Figure 15 The present application provides a data reading method using the optical reading and writing system described in any of the above embodiments, specifically reading data from the recording layer 21 of the disk 20.

[0128] Data writing methods include:

[0129] S200: The optical head torquer 10 moves the animal frame 11 along the focusing direction, the main beam objective lens 111 works, and the servo beam objective lens 112 does not work, so that the main beam 31 is focused on the disk 20;

[0130] S201: When detecting that the main light beam 31 is focused on the disk 20, the controller drives the disk 20 to rotate; the controller obtains a third guidance signal (wobble signal) based on the main light beam 31, and drives the objective lens holder 11 to move in the tracking direction according to the third guidance signal;

[0131] S202: During the movement of the objective lens holder 11 in the tracking direction, the controller obtains a second error signal based on the main light beam 31. The second error signal includes a focus error signal, a tracking error signal, and a tilt error signal. Based on the second error signal, the controller drives the objective lens holder 11 to move in the focus, tracking, and tilt directions. That is, the optical head torquer 10 drives the main beam objective lens 111 to vibrate at high frequencies in three degrees of freedom based on the focus signal, tracking signal, and tilt signal, so that the main light beam 31 is focused on the disk 20 within a certain error range.

[0132] S203 : When the controller determines that the wavefront aberration of the reading spot of the main beam 31 is within a preset range, the controller obtains a fourth pilot signal according to the main beam 31 , and the main beam 31 reads data information on the recording layer 21 according to the fourth pilot signal.

[0133] In summary, when the optical reading and writing system described in any of the above embodiments is used in the present application to write and read data, since the dual objective lenses of the present application are arranged side by side along the tangential direction of the optical disc, this can increase the effective reading and writing area of the optical head torquer on the disc and achieve high-quality reading and writing.

Claims

1. An optical head torquer (10), characterized in that: include: A driving unit (12), an objective lens holder (11), and a plurality of objective lenses mounted on the objective lens holder (11); wherein, The driving unit (12) is used to drive the objective lens holder (11) to move so that the multiple objective lenses focus the laser beam onto the disk (20); The plurality of objective lenses include a main beam objective lens (111) and a servo beam objective lens (112) arranged in parallel along a suspension line direction, the suspension line direction being parallel to a tangential direction of the disk (20), the main beam objective lens (111) being used to focus the main beam onto the disk (20), and the servo beam objective lens (112) being used to focus the servo beam onto the disk (20); The arrangement positions of the main beam objective lens (111) and the servo beam objective lens (112) satisfy the following conditions: the main beam and the servo beam can be simultaneously focused on the maximum readable and writable track circumference (R1) of the disk (20), wherein the radius of the maximum readable and writable track circumference (R1) is equal to the radius of the disk (20).

2. The optical head torquer (10) according to claim 1, characterized in that: The driving unit (12) is used to drive the objective lens holder (11) to move along a focusing direction, a tracking direction, and a tilting direction, wherein the focusing direction is a direction perpendicular to the surface of the disk (20), the tracking direction is a direction parallel to the radial direction of the disk (20), and the tilting direction is a direction rotating around a direction parallel to the tangential direction of the disk (20).

3. The optical head torquer (10) according to claim 2, characterized in that: The driving unit (12) comprises: A tilt driving magnetic circuit, used for providing a Lorentz force for driving the objective lens holder (11) to move along the tilt direction; A focusing drive magnetic circuit, used for providing a Lorentz force for driving the objective lens holder (11) to move along the focusing direction; The tracking drive magnetic circuit is used to provide a Lorentz force that drives the objective lens holder (11) to move along the tracking direction.

4. The optical head torquer (10) according to claim 3, characterized in that: The tilting drive magnetic circuit comprises: a first tilting coil (121) and a second tilting coil (122); The objective lens holder (11) comprises a first groove (113) and a second groove (114) provided on both sides of the plurality of objective lenses along the tracking direction, the first groove (113) and the second groove (114) respectively passing through the objective lens holder (11) along the focusing direction, the first tilting coil (121) being provided in the first groove (113), and the second tilting coil (122) being provided in the second groove (114).

5. The optical head torquer (10) according to claim 4, characterized in that: The first tilting coil (121) is provided on a groove wall (1131) of the first groove (113) facing the plurality of objective lenses, and the second tilting coil (122) is provided on a groove wall (1141) of the second groove (114) facing the plurality of objective lenses.

6. The optical head torquer (10) according to claim 4 or 5, characterized in that: The tilt drive magnetic circuit further includes: a first yoke (127), wherein a portion (1271) of the first yoke (127) extends along the focusing direction and is inserted into the first slot (113), and the portion (1271) of the first yoke (127) is spaced apart from the first tilt coil (121) along the tracking direction; A second yoke (129), a portion (1291) of the second yoke (129) extends along the focusing direction and is inserted into the second slot (114), and the portion (1291) of the second yoke (129) is spaced apart from the second tilt coil (122) along the tracking direction.

7. The optical head torquer (10) according to claim 6, characterized in that: The tilt drive magnetic circuit further includes: A first side magnet (131) and a second side magnet (132), wherein the N pole and the S pole of each side magnet are arranged along the focusing direction, the first side magnet (131) is arranged on a surface of the portion (1271) of the first yoke (127) facing the first tilted coil (121), and the second side magnet (132) is arranged on a surface of the portion (1291) of the second yoke (129) facing the second tilted coil (122).

8. The optical head torquer (10) according to claim 3, characterized in that: The focusing drive magnetic circuit comprises: a first focusing coil (124) and a second focusing coil (123); The objective lens holder (11) further comprises a third groove (115) and a fourth groove (116) provided on both sides of the objective lens along the suspension line direction, the third groove (115) and the fourth groove (116) respectively passing through the objective lens holder (11) along the focusing direction, the first focusing coil (124) being provided in the third groove (115), and the second focusing coil (123) being provided in the fourth groove (116).

9. The optical head torquer (10) according to claim 8, characterized in that: The focusing drive magnetic circuit further includes: a third yoke (128), wherein a first portion (1281) of the third yoke (128) extends along the focusing direction and is inserted into the third slot (115), and the first focusing coil (124) is arranged around the first portion (1281) of the third yoke (128); A fourth yoke (130), wherein a first portion (1301) of the fourth yoke (130) extends along the focusing direction and is inserted into the fourth slot (116), and the second focusing coil (123) is arranged around the first portion (1301) of the fourth yoke (130).

10. The optical head torquer (10) according to claim 9, characterized in that: The third yoke (128) further comprises a second portion (1283) located outside the objective lens holder (11), the second portion (1283) of the third yoke (128) extending along the focusing direction and spaced apart from the first portion (1281) of the third yoke (128) along the suspension line direction; The fourth yoke (130) further comprises a second portion (1303) located outside the objective lens holder (11), the second portion (1303) of the fourth yoke (130) extending along the focusing direction and spaced apart from the first portion (1301) of the fourth yoke (130) along the suspension line direction; The focusing drive magnetic circuit further includes: a first main magnet (133) and a second main magnet (134), wherein the N pole and the S pole of each main magnet are arranged along the suspension line direction, the first main magnet (133) is arranged on the surface of the second part (1283) of the third yoke (128) facing the objective lens holder (11), and the second main magnet (134) is arranged on the surface of the second part (1303) of the fourth yoke (130) facing the objective lens holder (11).

11. The optical head torquer (10) according to claim 9 or 10, characterized in that: The objective lens holder (11) is provided with a first mounting groove (117) and a second mounting groove respectively on surfaces facing the third yoke (128) and the fourth yoke (130) and penetrating the surface along the suspension line direction. The first mounting groove (117) allows the first focusing coil (124) to pass through so as to be arranged in the third groove (115), and the second mounting groove allows the second focusing coil (123) to pass through so as to be arranged in the fourth groove (116).

12. The optical head torquer (10) according to claim 10, characterized in that: The tracking drive magnetic circuit includes: Two pairs of tracking coils (125, 126) are located on the outer surface of the objective lens holder (11), wherein one pair of tracking coils (125) is located on the outer surface of the objective lens holder (11) facing the first main magnet (133), and the other pair of tracking coils (126) is located on the outer surface of the objective lens holder (11) facing the second main magnet (134).

13. The optical head torquer (10) according to claim 1, characterized in that: The outer contour of the projection of the objective lens holder (11) along the focusing direction is octagonal.

14. The optical head torquer (10) according to claim 13, characterized in that: The octagon is a regular octagon.

15. The optical head torquer (10) according to claim 3, characterized in that: Also includes: Terminal block (14); At least eight suspension wires (13) extending along the suspension direction, one end of the at least eight suspension wires (13) being connected to the wiring seat (14), and the other end being connected to the objective lens holder (11) to support the objective lens holder (11); Among them, six suspension wires (13) among the at least eight suspension wires (13) are used to respectively provide current to the coils in the focusing drive magnetic circuit, the tracking drive magnetic circuit and the tilting drive magnetic circuit.

16. An optical head, characterized in that: include: The optical head torque device (10) according to any one of claims 1 to 15, wherein the optical head torque device (10) is used for reading and writing a disk (20); as well as A light source is used to emit a main beam and a servo beam, a main beam objective lens (111) of the optical head torquer (10) is used to focus the main beam onto the disk (20), and a servo beam objective lens (112) of the optical head torquer (10) is used to focus the servo beam onto the disk (20).

17. A disc optical reading and writing system, characterized in that: include: A disk table, used for mounting a disk (20) and driving the disk (20) to rotate; as well as The optical head according to claim 16, wherein the optical head torquer (10) of the optical head is used for reading and writing the disk (20).

18. The optical disc reading and writing system according to claim 17, wherein: Also includes: The controller is used to control the rotation of the disk stage and to control the driving unit (12) to drive the objective lens holder (11) to move in a focusing direction, a tracking direction and a tilting direction.

19. A data writing method using the optical disc reading and writing system according to claim 17 or 18, characterized in that: The method comprises: detecting that the main beam and the servo beam are focused on the disk (20); driving the disc (20) to rotate; Acquiring a first guide signal according to the servo light beam, and driving the objective lens holder (11) to move along a tracking direction according to the first guide signal; acquiring a first error signal according to the servo beam, the error signal comprising a focus error signal, a tracking error signal, and a tilt error signal; According to the first error signal, driving the objective lens holder (11) to move in a focusing direction, a tracking direction and a tilting direction; Determining that the wavefront aberration of the writing spot of the main light beam is within a preset range; A second guide signal is acquired according to the servo light beam, and the main light beam writes data information on the recording layer of the disk (20) according to the second guide signal.

20. A data reading method using the optical disc reading and writing system according to claim 17 or 18, characterized in that: The method comprises: detecting that the main light beam is focused on the disk (20); driving the disc (20) to rotate; Acquiring a third guide signal according to the main light beam, and driving the objective lens holder (11) to move along a tracking direction according to the third guide signal; acquiring a second error signal according to the main light beam, the second error signal comprising a focus error signal, a tracking error signal, and a tilt error signal; According to the second error signal, driving the objective lens holder (11) to move in a focusing direction, a tracking direction and a tilting direction; Determining that the wavefront aberration of the reading spot of the main light beam is within a preset range; A fourth guide signal is acquired according to the main light beam, and the main light beam reads data information on the recording layer of the disk (20) according to the fourth guide signal.

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