A servo system and method

Abstract

The present application discloses a servo system and method, relating to the technical field of optical storage. This servo system solves the servo addressing problem when multi-focus parallel data reading is performed based on an array of light beams. The system includes an optical head assembly and a signal processing device. The optical head assembly is configured to generate a first set of optical signals including multiple optical signals, and to apply the first set of optical signals to multiple data points on an optical storage medium to obtain a second set of optical signals, which includes reference signals of at least three reference data points and data signals of data points to be read. The signal processing device is configured to receive the second set of optical signals, and obtain a servo control signal for adjusting the position of the optical head assembly according to the reference signals in the second set of optical signals and preset information of at least three reference points.

Description

Technical Field

[0001] The present application relates to the field of optical storage technology, and in particular to a servo system and method. Background Art

[0002] With the development of information technology, the amount of computing and storage of various information is growing exponentially. Optical storage is widely used as an important means of information storage. Traditional optical storage technology uses a single focus of a single beam to read and write data. In order to meet the needs of high-density and high-bandwidth data reading and writing, in the future, optical storage technology will use multi-focus based on homogeneous transparent materials and array beams to read and write data in parallel.

[0003] However, when reading data stored using optical storage technology, such as reading data from an optical disc, when the optical disc is rotating at high speed, due to the influence of mechanical vibration, environmental noise and disc flatness, the positions of the multiple focal points obtained after the array light beam used to read the data are focused separately will have relative deviations. If these deviations are not corrected by relative servo, they will affect the reading of real data. Since the traditional servo method used for reading data based on a single beam and a single focus is not suitable for servo correction of parallel reading of data through multiple focal points of an array light beam, how to servo address when reading data based on multiple focal points of an array light beam in parallel is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a servo system and method, which solves the servo addressing problem when reading data in parallel based on multi-focus of an array beam.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides a servo system, which includes an optical head assembly and a signal processing device. The optical head assembly is used to generate a first group of optical signals including multiple optical signals, and is used to apply the first group of optical signals to multiple data points on an optical storage medium to obtain a second group of optical signals. The second group of optical signals includes reference signals of at least three reference data points and data signals of data points to be read. The signal processing device is used to receive the second group of optical signals, and obtain a servo control signal for adjusting the position of the optical head assembly based on the reference signal in the second group of optical signals and preset information of at least three reference points.

[0007] Based on this servo system, multiple data points can be read through the first set of optical signals, and at least three reference data points among the multiple reference data points are used as the servo basis to generate a servo control signal. The servo system can perform servo adjustment on the optical head assembly according to the servo control signal, thereby effectively solving the servo addressing problem during multi-focus parallel data reading based on an array of light beams and improving the accuracy of the read data.

[0008] In a possible design, the above-mentioned servo control signal includes a focusing servo signal. The above-mentioned optical head assembly includes an optical head, and a voice coil motor is provided on the optical head. The voice coil motor is used to receive the focusing servo signal and adjust the coil current in the voice coil motor according to the focusing servo signal to adjust the position of the optical head in the axial direction of the optical head.

[0009] In another possible design, the above-mentioned servo control signal further includes a tracking servo signal. The above-mentioned optical head is further used to receive the tracking servo signal and adjust the current of the voice coil motor in the optical head according to the tracking servo signal to adjust the position of the optical head in a direction perpendicular to the axial direction of the optical head.

[0010] In another possible design, the above-mentioned servo control signal further includes a circumferential servo signal. The above-mentioned optical head assembly further includes a spatial light modulator and a rotating motor connected to the spatial light modulator. Among them, the spatial light modulator is used to generate the first set of optical signals. The rotating motor is used to receive the circumferential servo signal and adjust the rotating motor according to the circumferential servo signal to adjust the circumferential angle of the spatial light modulator.

[0011] Through these possible design methods, the servo system adjusts the focusing error of the optical head assembly according to the focusing servo signal, adjusts the tracking error of the optical head assembly according to the tracking servo signal, and adjusts the circumferential error of the optical head assembly according to the circumferential servo signal, thereby solving the servo addressing problem during multi-focus parallel data reading based on an array of light beams.

[0012] In another possible design, the above-mentioned signal processing device includes: a detector, which is used to receive the second set of optical signals and obtain the light intensity information and spot information of the reference signal in the second set of optical signals. A processor determines the servo control signal according to the foregoing light intensity information and spot information of the reference signal and the preset information of at least three reference data points. Among them, the preset information of the at least three reference data points includes the light intensity information and spot information of the at least three reference data points.

[0013] In this way, through this possible design method, the servo system determines the servo control signal based on the preset information of the reference data points and the reference signals of multiple currently read data points, and then can adjust the position of the optical head assembly, thus realizing the servo addressing problem in multi-focus parallel data reading based on the array beam.

[0014] In another possible design method, at least three voice coil motors are provided on the above-mentioned optical head, the number of reference data points corresponds to the number of voice coil motors, and the positions of the reference data points correspond to the positions of the voice coil motors.

[0015] Through this possible design method, at least three voice coil motors can be used to adjust at least three focal positions of the optical signals acting on at least three reference data points, and thus the position of the focal plane can be determined according to the at least three focal positions. In this way, the focusing servo and tracking servo in multi-focus parallel data reading based on the array beam are realized.

[0016] In a second aspect, the present application provides a servo method, which is applied to a servo system including an optical head assembly. The method includes: applying a first set of optical signals including multiple optical signals to multiple data points of an optical storage medium to obtain a second set of optical signals, where the second set of optical signals includes reference signals of at least three reference data points and data signals of data points to be read. Determining a servo control signal according to the reference signals and the preset information of at least three reference data points. Adjusting the position of the optical head assembly according to the servo control signal.

[0017] In a possible design method, the above-mentioned optical head assembly includes an optical head, the above-mentioned servo control signal includes a focusing servo signal, and "adjusting the position of the optical head assembly according to the servo control signal" includes: adjusting the current of the voice coil motor in the optical head according to the focusing servo signal to adjust the position of the optical head in the axial direction of the optical head.

[0018] In another possible design method, the above-mentioned servo control signal further includes a tracking servo signal, and "adjusting the position of the optical head assembly according to the servo control signal" further includes: adjusting the current of the voice coil motor in the optical head according to the tracking servo signal to adjust the position of the optical head in a direction perpendicular to the axial direction of the optical head.

[0019] In another possible design method, the above-mentioned servo system further includes a spatial light modulator and a rotating motor connected to the spatial light modulator, and the above-mentioned servo control signal further includes a circumferential servo signal. "Adjusting the position of the optical head assembly according to the servo control signal" further includes: adjusting the circumferential angle of the spatial light modulator by adjusting the rotating motor according to the circumferential servo signal, where the spatial light modulator is used to generate the first set of optical signals.

[0020] In another possible design, the above "determining the servo control signal according to the reference signal and the preset information of multiple reference points" includes: obtaining the light intensity information and the spot information of the reference signal. According to the light intensity information and the spot information of the reference signal, and the preset information of the at least three reference data points, determine the servo control signal. Wherein, the preset information of the at least three reference data points includes the light intensity information and the spot information of the at least three reference data points.

[0021] For the explanation of the servo method provided by the second aspect and any of its possible design manners and the description of the beneficial effects, reference can be made to the explanation of the servo system provided by the first aspect and any of its possible design manners and the beneficial effects, which will not be elaborated herein.

[0022] In a third aspect, the present application provides a servo control method applied to a servo system. The servo system includes a pickup head assembly. The method includes: controlling the pickup head assembly to generate a first set of optical signals including multiple optical signals. Controlling the first set of optical signals to act on multiple data points on an optical storage medium to obtain a second set of optical signals. Generating a servo control signal according to the light intensity information and the spot information of the reference signal in the second set of optical signals to adjust the position of the pickup head assembly.

[0023] For the explanation of the servo control method provided by the third aspect and the description of the beneficial effects, reference can be made to the explanation of the servo method provided by the second aspect and any of its possible design manners and the beneficial effects, which will not be elaborated herein.

[0024] In a fourth aspect, the present application provides a servo control device including a processor and a memory. The processor is used to call and run a computer program stored in the memory to execute the servo control method in the third aspect.

[0025] In a fifth aspect, the present application provides a computer program product, which when running on a servo control device, causes the servo control method in the third aspect to be executed.

[0026] In a sixth aspect, the present application provides a computer-readable storage medium, such as a non-transitory computer-readable storage medium. A computer program (or instruction) is stored thereon, and when the computer program (or instruction) runs on a servo control device, the servo control device is caused to execute the servo control method provided in the above third aspect.

[0027] It can be understood that any of the above-provided servo control devices, computer program products, or computer storage media can be applied to the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding methods, which will not be elaborated herein.

[0028] In this application, the names of the above servo systems or servo control devices do not constitute a limitation on the devices or functional modules themselves. In actual implementation, these devices or functional modules may appear under other names. As long as the functions of each device or functional module are similar to those of this application and fall within the scope of the claims of this application and their equivalent technologies.

[0029] These aspects or other aspects of this application will be made more concise and understandable in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the shape of the focal point array of the array beam provided by the embodiment of this application;

[0031] Figure 2 Schematic diagram of writing data blocks on an optical storage medium by the array beam provided by the embodiment of this application;

[0032] Figure 3 Schematic diagram of the focusing error provided by the embodiment of this application;

[0033] Figure 4 Schematic diagram of the tracking error provided by the embodiment of this application;

[0034] Figure 5 Schematic diagram of the circumferential error provided by the embodiment of this application;

[0035] Figure 6 Schematic diagram of the structure of the servo system provided by the embodiment of this application;

[0036] Figure 7 Schematic diagram of a kind of data block provided by the embodiment of this application;

[0037] Figure 8 Schematic diagram of another kind of data block provided by the embodiment of this application;

[0038] Figure 9 Schematic diagram of yet another kind of data block provided by the embodiment of this application;

[0039] Figure 10 Schematic diagram of the structure of the optical head provided by the embodiment of this application;

[0040] Figure 11 Schematic diagram of a kind of determining the adjustment direction when adjusting the position of the optical head assembly in the servo control signal according to the spot size and shape provided by the embodiment of this application;

[0041] Figure 12 Schematic diagram of another kind of determining the adjustment direction when adjusting the position of the optical head assembly in the servo control signal according to the spot size and shape provided by the embodiment of this application;

[0042] Figure 13Another schematic diagram provided by the embodiment of the present application for determining the adjustment direction when adjusting the position of the optical head assembly according to the spot size and shape;

[0043] Figure 14 A schematic flowchart of a servo method provided by the embodiment of the present application. Detailed implementation manners

[0044] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0045] In the embodiments of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0046] The meaning of the term "at least one" in the present application is one or more, and the meaning of the term "a plurality" in the present application is two or more. For example, a plurality of second messages means two or more second messages. The terms "system" and "network" are often used interchangeably herein.

[0047] It should be understood that the terms used in the description of various examples herein are only for the purpose of describing specific examples and are not intended to be limiting. As used in the description of various examples and the appended claims, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0048] It should also be understood that in the various embodiments of the present application, the magnitudes of the sequence numbers of the various processes do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0049] It should be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0050] It should also be understood that the term "comprises" (also referred to as "includes", "including", "comprises" and / or "comprising") when used in this specification specifies the presence of the stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0051] It should also be understood that the term "if" can be interpreted to mean "when" ("when" or "upon") or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if it is determined..." or "if [the stated condition or event] is detected" can be interpreted to mean "when it is determined..." or "in response to determining..." or "when [the stated condition or event] is detected" or "in response to detecting [the stated condition or event]".

[0052] It should be understood that the references to "one embodiment", "an embodiment", "a possible implementation" throughout the specification mean that a particular feature, structure, or characteristic related to the embodiment or implementation is included in at least one embodiment of the present application. Thus, the appearances of "in one embodiment" or "in an embodiment", "a possible implementation" throughout the specification do not necessarily refer to the same embodiment. In addition, these particular features, structures, or characteristics may be combined in one or more embodiments in any suitable manner.

[0053] In order to meet the high-density and high-bandwidth requirements of optical storage, optical storage technology has gradually started to use array beams to read and write data in parallel. That is, multiple optical signals are simultaneously applied to the optical storage medium to achieve data reading and writing. Among them, an array beam refers to a group of optical signals including multiple optical signals.

[0054] The shape of the focus array generated after the multiple optical signals included in the array beam are respectively focused by an optical head (such as an objective lens) can be any shape. For example, the shape of the focus array can be any one of a straight line, a square, a rectangle, a rhombus, a circle, or an ellipse, etc.

[0055] It should be understood that after the multiple optical signals included in the array beam are respectively focused by the optical head, the array formed by the foci of each optical signal in the array beam is the focus array of the array beam.

[0056] Reference Figure 1 , Figure 1 exemplarily shows several shapes of the focus array. Among them, the black dots represent the foci of the optical signals after being focused by the optical head. As Figure 1 shown in (a) ofFigure 1 As shown in (b) of Figure 1 As shown in (c) of

[0057] Among them, as Figure 1 shown, Figure 1 The distribution of the foci in the focus array shown in Figure 1 can be a uniform distribution, such as shown in (a) of Figure 1 and (b) of Figure 1 Of course, the distribution of the foci in the focus array shown in Figure 1 can also be a non-uniform distribution, such as shown in (c) of

[0058] It should be understood that the distribution of the multiple optical signals included in the array beam corresponds to the distribution of the foci in the focus array of the array beam.

[0059] When writing data using an array beam, the optical storage medium for storing data is located on the focal plane after the array beam is focused by the optical head. In this way, when an array beam including m optical signals acts on the optical storage medium after being focused by the optical head, m light spots (i.e., m foci) can be generated. In this way, the optical signals with different intensities in the array beam can make the optical storage medium at the positions of the m foci exhibit different physical and / or chemical properties, thereby realizing data writing. Among them, m is an integer greater than or equal to 2.

[0060] When the recording method of the optical storage medium is the reflective light type, the different physical and / or chemical properties presented by the optical storage medium can make the optical storage medium have different reflectivities. When the recording method of the optical storage medium is the spontaneous fluorescence type, the optical storage medium can have different fluorescence emission rates.

[0061] It can be seen that when recording binary numbers, two states of physical and / or chemical properties on the optical storage medium are required. In this way, state 1 can be used to represent "0", and state 2 can be used to represent "1". Or, state 1 can be used to represent "1", and state 2 can be used to represent "0". Similarly, when recording decimal numbers, ten states of physical and / or chemical properties on the optical storage medium are required, which will not be elaborated here.

[0062] It can be seen that the positions of the m foci on the optical storage medium are the m data points on the optical storage medium. These m data points constitute the data block written on the optical storage medium by the array beam used to generate the m foci. Generally, an optical storage medium with data written thereon can be referred to as an optical storage medium (such as an optical disc recording data content), and an optical storage medium without data written thereon can be referred to as a blank disc.

[0063] It can be seen that for a data block on the optical storage medium, the shape of the data block is the shape of the focus array on the optical storage medium after the array beam written to the data block is respectively focused by the optical head. Among them, the size and shape of the data points in the data block are the same as the size and shape of the foci in the focus array; the number of data points in the data block is the same as the number of foci in the focus array (that is, the number of data points in the data block is the same as the number of optical signals included in the array beam written to the data block); and the distribution of the data points in the data block is the same as the distribution of the foci in the focus array.

[0064] It can be seen that when the array beam writes a data block, one optical signal in the array beam corresponds to one data point in the data block, that is, the optical signals included in the array beam and the data points in the data block are in one-to-one correspondence.

[0065] As an example, refer to Figure 2 , Figure 2 shows a schematic diagram of writing a data block 201 on an optical storage medium 20 using an array beam including (4×4) optical signals. As Figure 2 shown, the thick black straight line with an arrow in the middle represents the array beam. When the array beam is respectively focused by the optical head and acts on the optical storage medium 20, a data block 201 can be written on the optical storage medium. Among them, the data block 201 includes 4×4 data points, as shown by the black dots in Figure 1 .

[0066] It should be understood that when writing multiple data blocks using an array beam including multiple optical signals, the present application embodiment does not specifically limit the distribution trajectory of the multiple data blocks.

[0067] When reading data using the array beam, data can be read by the array beam acting on the optical storage medium with data recorded thereon and collecting the optical signals fed back by the optical storage medium.

[0068] Specifically, when the array beam for reading data is respectively focused by the optical head and acts on the optical storage medium with data recorded thereon, in one case, data can be read by collecting the reflected beam of the optical storage medium. In another case, data can be read by collecting the spontaneous fluorescence generated by the optical storage medium after being acted on by the array beam.

[0069] It should be understood that if data is written on the optical storage medium by the array beam 1, then for the array beam 2 used to read the data, except that the optical power is different from that of the array beam 1, the remaining parameters are the same. For example, the number of optical signals included in the array beam, the distribution of the optical signals included in the array beam, the shape of the focal point array generated after the group of optical signals are focused by the optical head with the same focusing parameters, etc., are all the same.

[0070] During the process of reading data on the optical storage medium by the array beam, it is necessary for the optical signals included in the array beam to be accurately focused on the data blocks of the optical storage medium by the optical head respectively, that is, it is necessary for the focal point array obtained after the optical signals in the array beam are focused respectively to overlap with the data blocks. Usually, only when the overlap rate between each focal point in the focal point array and the data point corresponding to each focal point in the data block is greater than a preset threshold, can the array beam accurately read the data in the data block. Among them, the embodiment of the present application does not specifically limit the value of the preset threshold.

[0071] In practical applications, when reading data on an optical storage medium (such as an optical disc), the optical disc is usually in a state of high-speed rotation. During the high-speed rotation of the optical disc, it is often affected by mechanical vibration, environmental noise, and the flatness of the disc. Therefore, the above-mentioned situation where the overlap rate is less than the preset threshold will occur. In this case, the optical signals used to read the data cannot be accurately focused on the data points on the optical disc, and thus the data on the optical disc cannot be accurately read.

[0072] It should be understood that the embodiment of the present application does not specifically limit the above situation where the overlap rate is equal to the preset threshold. For example, when the overlap rate is equal to the preset threshold, the optical signals can accurately read the data on the optical disc. Or, when the overlap rate is equal to the preset threshold, the optical signals cannot accurately read the data on the optical disc, etc.

[0073] Generally, the main reasons for the above situation where the overlap rate is less than or equal to the preset threshold are as follows:

[0074] 1) Focusing error

[0075] When using the array beam to read data on the optical storage medium, it is usually necessary for the optical head to focus each optical signal in the array beam on the disc surface of the optical storage medium, that is, the focal plane after the array beam is focused by the optical head respectively coincides with the disc surface of the optical storage medium. When there is a certain distance between the focal plane of the array beam after being focused by the optical head and the disc surface of the optical storage medium, it means that the array beam is not focused on the disc surface of the optical storage medium.

[0076] Therefore, the focusing error, which can also be referred to as the axial error or defocus amount, specifically refers to the distance between the focal plane of the array beam after being focused by the optical head and the disk surface of the optical storage medium.

[0077] Reference Figure 3 , Figure 3 shows a schematic diagram of the focusing error. As Figure 3 shown, the solid line is used to represent the front view of the optical storage medium 31, and the dashed line is used to represent the front view of the focal plane 32 of the array beam after being focused by the optical head. Therefore, the focusing error is used to indicate the distance between the optical storage medium 31 and the focal plane 32, such as Δz1 and Δz2. Among them, Δz1 can represent the distance between the data point A1 on the optical storage medium 31 and the focal point A2 on the focal plane 32, and Δz2 can represent the distance between the data point B1 on the optical storage medium 31 and the focal point B2 on the focal plane 32. Among them, the data point A1 corresponds to the focal point A2, and the data point B1 corresponds to the focal point B2.

[0078] 2) Tracking error

[0079] The tracking error, which can also be referred to as the radial error. When the focal plane generated by the array beam after being focused by the optical head overlaps with the disk surface of the optical storage medium, the tracking error is used to indicate the distance between the focal point array generated by the array beam after being focused by the optical head and the data block to be read on the optical storage medium in the plane where the disk surface is located. That is, the tracking error is used to indicate the radial offset amount of the focal point array deviating from the data block to be read in the plane where the disk surface is located.

[0080] Among them, in the two-dimensional plane where the disk surface of the optical storage medium is located, the radial offset amount includes the x-axis offset amount and the y-axis offset amount.

[0081] As Figure 4 shown, Figure 4 shows a schematic diagram of the tracking error. As Figure 4 shown, in the two-dimensional plane where the disk surface of the optical storage medium is located, the data block 41 includes 5×3 data points ( Figure 4 the data points are represented by black dots in it), and the focal point array 42 of the array beam for reading data includes 5×3 focal points ( Figure 4 the focal points are represented by striped dots in it). As Figure 4 shown, the radial offset amount between the data block 41 and the focal point array 42 includes the x-axis offset amount Δx and the y-axis offset amount Δy. Among them, Δx represents the distance between the data block 41 and the focal point array 42 in the x-axis direction, and Δy represents the distance between the data block 41 and the focal point array 42 in the y-axis direction.

[0082] 3) Circumferential error

[0083] When the focal plane generated after the array beam is focused by the optical head overlaps with the disk surface of the optical storage medium, the circumferential error is usually used to indicate the circumferential angle between the focal point array and the data block to be read.

[0084] Reference Figure 5 , Figure 5 shows a schematic diagram of the circumferential error. As Figure 5 shown, the data block 51 includes 5×3 data points ( Figure 1 the data points are represented by black dots in Figure 1 ), and the focal point array 52 of the array beam for reading data includes 5×3 focal points ( Figure 1 the focal points are represented by striped dots in ). Among them, the circumferential error is used to indicate the angle between the data block 51 and the focal point array 52 as Δθ.

[0085] It should be understood that when reading data on the optical storage medium with a single beam of optical signal, there is no circumferential error in the system for reading optical storage data.

[0086] Based on this, the embodiments of the present application provide a servo system and method, which effectively solve the servo addressing problem when reading data in parallel with multiple focal points of the array beam based on the reported multi-beam optical signal.

[0087] Reference Figure 6 , Figure 6 shows a schematic structural diagram of the servo system 60 provided by the embodiments of the present application. As Figure 6 shown, the servo system 60 may include a light source 61, a beam splitting device 62, an optical head assembly 63, and a signal processing device 64.

[0088] Among them, the light source 61 may be a laser light source, such as a laser diode, etc. The light source 61 is used to generate an initial optical signal for reading data blocks on the optical storage medium 65, and the initial optical signal may be a single-beam laser signal or a multi-beam laser signal. Here, the embodiments of the present application do not specifically limit the wavelength of the initial optical signal generated by the laser light source 61.

[0089] The beam splitting device 62 is used to receive the initial optical signal generated by the light source 61 and transmit the initial optical signal through the optical head assembly 63.

[0090] Among them, when the optical storage medium records data in a reflection light type, the beam splitting device 62 may be a flat or prism-type beam splitter. Here, the beam splitter may be a lens that transmits or reflects the incident light based on the polarization direction of the incident light. When the optical storage medium records data in a spontaneous fluorescence type, the beam splitting device 62 may be a dichroic mirror. Here, the dichroic mirror may transmit long-wavelength lasers and reflect short-wavelength fluorescence.

[0091] The optical head component 63 is used to receive an initial optical signal, obtain a first set of optical signals based on the initial optical signal, and apply the first set of optical signals to the data blocks on the optical storage medium 65 to obtain a second set of optical signals. Among them, after the second set of optical signals is processed by the information processing device 62, the data on the data blocks can be obtained.

[0092] Among them, the first set of optical signals includes multiple optical signals, and the multiple optical signals correspond one by one to the multiple data points included in the data blocks acted on by the first set of optical signals.

[0093] It should be understood that the power of each optical signal in the first set of optical signals is less than or equal to a first preset threshold. In this way, when the optical signal acts on the optical storage medium 65, the physical and / or chemical properties of the optical storage medium 65 are not changed. Of course, the power of each optical signal in the first set of optical signals can be the same or different, and the embodiments of the present application do not make specific limitations on this.

[0094] For simplicity of description, hereinafter, the power of each optical signal in the first set of optical signals is the first preset power, and the value of the first preset power is less than or equal to the first preset threshold.

[0095] The optical head component 63 may include a spatial light modulator (SLM) 631 and an optical head 633. Optionally, the optical head component 63 may further include a rotating motor 632.

[0096] Among them, the SLM 631 is used to receive the initial optical signal and split the initial optical signal into a first set of optical signals. Then, the SLM 631 sends the first set of optical signals to the optical head 633. It should be understood that considering optical loss, the sum of the powers of all optical signals in the first set of optical signals is less than or equal to the power of the initial optical signal.

[0097] The rotating motor 632 is connected to the SLM 631 and is used to rotate the SLM 631 in a plane perpendicular to the axial direction of the optical head 633 to adjust the circumferential angle of the SLM 631.

[0098] Exemplarily, as Figure 6 shown, Figure 6 The rotating motor 632 shown is a cross-sectional schematic diagram of an annular rotating motor.

[0099] Specifically, the SLM 631 can be installed on the rotating motor 632. The rotating motor 632 is electrically connected to the processor 642 of the signal processing device 64 and is used to receive the circumferential servo signal sent by the processor 642, so as to rotate the SLM 631 according to the circumferential servo signal to adjust the circumferential angle of the SLM 631, thereby achieving the purpose of adjusting the circumferential angle of the first group of optical signals. Here, the description of the circumferential servo signal can be referred to in the following text and will not be elaborated here.

[0100] The optical head 633 is used to receive the first group of optical signals, focus the multiple optical signals included in the first group of optical signals respectively, and then act on multiple data points of the optical storage medium 65 to obtain the second group of optical signals. Among them, the optical head 633 can be an objective lens.

[0101] In one case, after the first group of optical signals are focused by the optical head 633 and act on multiple data points, the first group of optical signals are reflected according to the reflectivity of the multiple data points on the optical storage medium, so as to obtain the second group of optical signals. It can be seen that in this case, the second group of optical signals is the reflected signal of the first group of optical signals.

[0102] In another case, after the first group of optical signals are focused by the optical head 633 and act on multiple data points, according to the fluorescence emission rate of the multiple data points on the optical storage medium, each data point emits spontaneous fluorescence, so as to obtain the second group of optical signals. It can be seen that in this case, the second group of optical signals is a fluorescence signal.

[0103] It should be understood that between the SLM 631 and the optical storage medium 65, the optical paths of the second group of optical signals and the first group of optical signals are opposite. After the first group of optical signals are focused by the optical head 633 and act on multiple data points, the multiple formed light spots can be regarded as multiple point light sources that generate the second group of optical signals. The reflected light signals or fluorescence signals emitted by the multiple point light sources can be transmitted to the SLM 631 through the optical head 633.

[0104] In one case, when the optical storage medium 65 records data in a reflection light type, in this case, after receiving the second group of optical signals, the SLM631 adjusts the polarization direction of the optical signals in the second group of optical signals and emits the second group of optical signals with the adjusted polarization direction to the beam splitter 62. At this time, the beam splitter 62 is a flat or prism beam splitter. In this way, the beam splitter 62 can reflect the second group of optical signals with the adjusted polarization direction to the detector 641 in the signal processing device 64.

[0105] In another case, when the optical storage medium 65 records data in a spontaneous fluorescence type, after the SLM 631 receives the second set of optical signals, it transmits the second set of optical signals to the beam splitter 62. At this time, the beam splitter 62 is a dichroic mirror. In this way, the beam splitter 62 can reflect the received second set of optical signals onto the detector 641 in the signal processing device 64.

[0106] It can be understood that the light source 61, the beam splitter 62, and the optical head assembly 63 can also be used to obtain a third set of optical signals according to the coding information of the data to be written. The third set of optical signals is used to be focused on the optical storage medium, so as to realize the writing of the data to be written. Among them, the number of light beams in the third set of optical signals is the same as the number of optical signals in the first set of optical signals. And, the power of a single optical signal in the third set of optical signals can be greater than or equal to the first preset threshold. In this way, when the third set of optical signals is focused on the optical storage medium, the physical and / or chemical properties of the position on the optical storage medium that is acted on can be changed, so as to realize the corresponding data writing.

[0107] It should be understood that the process of the optical head assembly 63 obtaining the third set of optical signals is the same as the process of obtaining the first set of optical signals, and will not be elaborated here.

[0108] It should be noted that in the above-mentioned second set of optical signals, it includes a reference signal of at least three reference data points and a data signal of the data points to be read. The reference signal of the at least three reference data points is used to determine the servo control signal for adjusting the position of the optical head assembly. The data signal of the data points to be read is used to decode the data read from the optical storage medium.

[0109] Among them, the at least three reference data points can be written when the third set of optical signals obtained by the optical head assembly 63 writes data on the optical storage medium 65. Among them, when the multiple optical signals included in the third set of optical signals act on the optical storage medium, one data block can be written. The one data block includes multiple data points, and the multiple data points include the at least three reference data points.

[0110] Among them, in the third set of optical signals, at least three optical signals for writing the at least three reference data points can be at least three optical signals with a preset power and whose optical axes are not in the same plane. Here, the preset powers of the at least three optical signals can be the same (for example, the second preset power), or different, and the embodiments of the present application do not make specific limitations on this.

[0111] In this way, when the at least three optical signal beams are focused on the optical storage medium, at least three reference data points can be written. In this case, the positions of the at least three reference data points correspond to the at least three optical signal beams. The at least three reference data points are three data points in the data block written by the third group of optical signals and not on the same straight line.

[0112] In a data block written by the above-mentioned third group of optical signals on the optical storage medium, there is also a block address data point. Among them, the block address data point is used to mark the address of the current data block among multiple data blocks. Usually, at least one data point can be used as the block address data point.

[0113] As an example, if one data point is used as the block address data point. Then, when the data recorded on the optical storage medium is binary data, this one data point can be used to mark the block addresses of 2 data blocks; when the data recorded on the optical storage medium is decimal data, this one data point can be used to mark the block addresses of 10 data blocks. Similarly, if three data points are used as the block address data points, then when the data recorded on the optical storage medium is binary data, these three data points can be used to mark the block addresses of 8 data blocks; when the data recorded on the optical storage medium is decimal data, these three data points can be used to mark the block addresses of 1000 data blocks.

[0114] In a data block written by the above-mentioned third group of optical signals on the optical storage medium, there is also a data point for the data to be written. The data point for the data to be written is used to record the written data.

[0115] Reference Figure 7 , Figure 7 shows a schematic diagram of the data block written after the third group of optical signals act on the optical storage medium. As Figure 7 shown, in data block 70, there are 4×4 data points. Among them, among the 4×4 data points, there are three reference data points, namely reference data point 711, reference data point 712, and reference data point 713. It can be seen that reference data point 711, reference data point 712, and reference data point 713 are not on the same straight line. Reference data point 711, reference data point 712, and reference data point 713 can form a triangle. As Figure 7 shown, among the 4×4 data points, there can also be a block address data point 72. Reference data point 711, reference data point 712, reference data point 713, and block address data point 72 can be the vertices of a quadrilateral. In addition, Figure 7 the black dots shown can represent the data points for recording data information.

[0116] Reference Figure 8 , Figure 8Another schematic diagram of the data block written after the third group of optical signals act on the optical storage medium is shown. As Figure 8 shown, the data block 70 includes 4×4 data points. Among the 4×4 data points, there are three reference data points, namely reference data point 811, reference data point 812, and reference data point 813. It can be seen that reference data point 811, reference data point 812, and reference data point 813 are not on the same straight line. Reference data point 811, reference data point 812, and reference data point 813 can present as a triangle. As Figure 8 shown, among the 4×4 data points, there is also a block address data point 72. In addition, Figure 8 the black dots shown can represent the data points for recording data information.

[0117] Reference Figure 9 , Figure 9 Another schematic diagram of the data block written after the third group of optical signals act on the optical storage medium is shown. As Figure 9 shown, the data block 70 includes 4×4 data points. Among the 4×4 data points, there are three reference data points, namely reference data point 811, reference data point 812, reference data point 813, and reference data point 914. It can be seen that reference data point 811, reference data point 812, reference data point 813, and reference data point 914 are not on the same straight line. As Figure 8 shown, among the 4×4 data points, there is also a block address data point 72. In addition, Figure 7 the black dots shown can represent the data points for recording data information.

[0118] In addition, at least three voice coil motors are provided on the optical head 633, and the at least three voice coil motors are used to adjust the position of the optical head 633 in the axial direction of the optical head 633 and in the direction perpendicular to the axial direction. The number of voice coil motors provided on the optical head 633 corresponds to the number of reference data points in one data block described above, and the position of the reference data point corresponds to the position of the voice coil motor corresponding to the reference data point.

[0119] Optionally, the voice coil motors provided on the optical head 633 can correspond one by one to the reference data points in one data block described above, or among the voice coil motors provided on the optical head 633, multiple voice coil motors can correspond to one reference data point in one data block described above. The embodiments of the present application do not limit this.

[0120] Reference Figure 10 , taking the example that three voice coil motors are provided on the optical head 633, Figure 10 a schematic diagram of the structure of the optical head 633 is shown. Among them,Figure 10 In (a) therein, a front view of the structural schematic diagram is shown. Figure 10 In (b) therein, a top view of the structural schematic diagram is shown.

[0121] As Figure 10 shown in (a) therein, the main optical unit bracket 101 and the bracket 105 in the servo system 60 are connected by a flexible connector 103, and the optical head 633 is fixed on the bracket 105. On the main optical unit bracket 101, three permanent magnets are provided, namely the permanent magnet 1021, the permanent magnet 1022, and the permanent magnet 1023. On the bracket 105, three voice coil motors are provided, namely the voice coil motor 1041, the voice coil motor 1042, and the voice coil motor 1043. Among them, the permanent magnet 1021 corresponds to the voice coil motor 1041 to form an adjusting device 1 for adjusting the position of the optical head 633. Similarly, the permanent magnet 1022 corresponds to the voice coil motor 1042 to form an adjusting device 2 for adjusting the position of the optical head 633. The permanent magnet 1023 corresponds to the voice coil motor 1043 to form an adjusting device 3 for adjusting the position of the optical head 633.

[0122] It should be noted that in the axial direction of the optical head 633, the central axis of the permanent magnet in an adjusting device does not coincide with the central axis of the voice coil motor.

[0123] Among them, when the servo system 60 adjusts the current magnitudes of the voice coil motors in the adjusting device 1, the adjusting device 2, and the adjusting device 3, the adjusting device 1, the adjusting device 2, and the adjusting device 3 can generate magnetic fields with corresponding intensities. Then, the magnetic force generated by the magnetic field can Figure 10 adjust the position of the optical head 633 in the x-axis, y-axis, and z-axis directions shown in (b) therein. Among them, the z-axis represents the axial direction of the optical head 633, and the x-axis and y-axis represent the directions perpendicular to the axial direction of the optical head 633.

[0124] Figure 10 In (d) therein, a schematic diagram of the data block 100 is shown. In the data block 100, three data reference points are included, namely the data reference point 1001, the data reference point 1002, and the data reference point 1003. As Figure 10 shown, the position of the adjusting device 1 corresponds to the data reference point 1001 (i.e., the position of the voice coil motor 1041 corresponds to the data reference point 1001), the position of the adjusting device 2 corresponds to the data reference point 1002 (i.e., the position of the voice coil motor 1042 corresponds to the data reference point 1002), and the position of the adjusting device 3 corresponds to the data reference point 1003 (i.e., the position of the voice coil motor 1043 corresponds to the data reference point 1003).

[0125] The signal processing device 64 includes a detector 641 and a processor 642. Among them, the detector 641 is used to convert the received second group of optical signals into electrical signals and send the electrical signals to the processor 642 for processing. The processor 642 can further process the information received from the detector 641 to obtain the data to be read and determine the servo control signal.

[0126] Among them, the detector 641 can be an array-type photodetector. Among them, the detector 641 can include a plurality of photodetection units, and the number of the plurality of photodetection units included in the detector 641 is greater than or equal to the number of optical signals included in the second group of optical signals.

[0127] Among them, one photodetection unit can include at least one pixel point, and the embodiments of the present application do not make specific limitations on this. It should be understood that one photodetection unit can be used to process one optical signal in the second group of optical signals. In this way, the reference signal and the data signal in the second group of optical signals can be respectively sent to the processor 642 for further processing after being processed by different photodetection units.

[0128] Specifically, after receiving the second group of optical signals, the detector 641 can determine the light intensity information of each optical signal in the second group of optical signals and the spot information of the spot formed by the optical signal on its corresponding photodetection unit. Alternatively, after receiving the second group of optical signals, the detector 641 can determine the light intensity information of each optical signal in the second group of optical signals and the spot information of the spot formed by the reference signal in the second group of optical signals on its corresponding photodetection unit. Among them, the spot information includes the spot shape and the spot size.

[0129] Then, the detector 641 can send the determined light intensity information and spot information of the second group of optical signals to the processor 642 for further processing.

[0130] Here, since the reference signal and the data signal in the second group of optical signals are sent to the processor 642 after being processed by different photodetection units, when the processor 642 determines the servo control signal according to the light intensity information and spot information of the reference signal, compared with the prior art in which it is necessary to extract the servo optical signal for determining the servo control signal from the data signal according to the frequency information, the solution provided by the embodiments of the present application is convenient and efficient.

[0131] Then, the processor 642 can decode the data to be read according to the preset decoding rule and the light intensity information of the received data signal. Here, the preset decoding rule corresponds to the encoding rule when the data information stored in the optical storage medium 65 is written, which will not be elaborated here.

[0132] The processor 642 can also determine a servo control signal based on the optical intensity information and spot information of the received reference signal, as well as the preset information of at least three reference data points.

[0133] Among them, the preset information of the at least three reference data points includes the optical intensity information and spot information of the at least three reference data points. Here, the optical intensity information and spot information of the at least three reference data points refer to the optical intensity information and spot information of the optical signals returned by the at least three reference data points when at least three optical signals are accurately focused on the at least three reference data points respectively. Among them, the optical signal can be a reflected optical signal or a fluorescence signal. Among them, the power of each optical signal in the at least three optical signals is a first preset power.

[0134] Among them, the optical intensity information and spot information of the optical signals returned by the at least three reference data points can be pre-determined. Specifically, taking the servo system 60 as an example of pre-determining the optical intensity information and spot information of the optical signals returned by the at least three reference data points, the servo system 60 can use at least three optical signals with a first preset power to accurately focus on the at least three reference data points, so as to obtain the optical signals returned by the at least three reference data points. Then, the detector 641 receives the optical signal and determines the optical intensity information and spot information of the optical signal. In this way, the optical intensity information and spot information of the optical signal are the preset information of the at least three reference data points.

[0135] It can be seen that the power of the optical signal used to measure the preset information of the at least three reference data points is the same as the power of the optical signal in the first group of optical signals used to act on the at least three reference data points.

[0136] For convenience of description, in the embodiments of the present application, the optical intensity information in the preset information of the at least three reference data points is referred to as the first optical intensity information, and the spot information in the preset information of the at least three reference data points is referred to as the first spot information. In addition, in the embodiments of the present application, the optical intensity information of the reference signal received by the processor 642 is referred to as the second optical intensity information, and the spot information of the reference signal received by the processor 642 is referred to as the second spot information.

[0137] In this way, the processor 642 can determine the servo control signal according to the received second optical intensity information and second spot information, as well as the preset first optical intensity information and first spot information. Among them, the servo control signal includes at least one of a focusing servo signal, a circumferential servo signal, or a tracking servo signal.

[0138] In one aspect, the processor 641 can determine the adjustment direction when adjusting the position of the optical head assembly in the servo control signal according to the spot size and spot shape in the first spot information, as well as the spot size and spot shape in the second spot information.

[0139] As an example, refer to Figure 11 , Figure 11 which shows a schematic diagram for determining the adjustment direction when adjusting the position of the optical head assembly according to the spot size and shape in the servo control signal.

[0140] As Figure 11 shown, the solid circle represents the spot 111 in the preset information of the reference data points. The overlapping part of the solid circle and the dashed circle represents the spot 112 of the reference signal in the second group of optical signals above. As Figure 11 shown, the processor 642 can determine, based on the shapes and sizes of the spot 111 and the spot 112, that the optical head 633 does not focus the optical signal for acting on the reference data points on the optical storage medium 65. Therefore, the processor 632 can determine that it is necessary to adjust the position of the optical head 633 in the axial direction of the optical head 633 towards the direction close to the optical storage medium.

[0141] Refer to Figure 12 , Figure 12 which shows another schematic diagram for determining the adjustment direction when adjusting the position of the optical head assembly according to the spot size and shape in the servo control signal.

[0142] As Figure 12 shown, the solid circle represents the spots (including spot 120a, spot 120b, and spot 120c) in the preset information of the reference data points. The overlapping part of the solid circle and the dashed circle represents the spots of the reference signal in the second group of optical signals above, including spot 121a, spot 121b, and spot 121c. As Figure 12 shown, if the spots 120a, 120b, and 120c are connected, a preset spot plane 120 can be obtained. Similarly, if the spots 121a, 121b, and 121c are connected, a reference spot plane 121 of the reference signal can be obtained. In this way, the processor 642 can determine, based on the preset spot plane 120 and the reference spot plane 121, that the optical head 633 needs to rotate the SLM 631 in the plane direction perpendicular to the axial direction of the optical head 633 (for example, Figure 10 in the plane direction formed by the x-axis and the y-axis shown in

[0143] Refer to Figure 13 , Figure 13 which shows yet another schematic diagram for determining the adjustment direction when adjusting the position of the optical head assembly according to the spot size and shape in the servo control signal.

[0144] As Figure 13 shown, the solid circle represents the spot 131 in the preset information of the reference data points. The overlapping part of the solid circle and the dashed circle represents the spot 132 of the reference signal in the second group of optical signals above. AsFigure 13 As shown, the processor 642 can determine, according to the shapes and sizes of the light spots 131 and 132, that the optical head 633 needs to adjust the position of the optical head 633 along the positive x-axis direction and the positive y-axis direction in a direction perpendicular to the axial direction of the optical head 633 (such as Figure 13 the x-axis direction and the y-axis direction shown in the figure).

[0145] On the other hand, the processor 642 can determine the focusing error, tracking error, and circumferential error of the optical head assembly 63 according to the first light intensity information and the second light intensity information. It can be understood that if the first light intensity information (or the second light intensity information) corresponds to three reference data points, the focusing error includes the focusing errors of these three reference data points.

[0146] Specifically, for any one of the at least three reference data points above, such as reference data point 1, the processor 642 can subtract the light intensity corresponding to this reference data point 1 in the first light intensity information from the light intensity corresponding to this reference data point 1 in the second light intensity information, and determine the focusing error, tracking error, and circumferential error of the optical head assembly according to this difference.

[0147] Optionally, designers can preset, in the processor 642 through a large number of test results, the corresponding relationships between the differences between different light intensities and the light intensities corresponding to different reference data points in the first light intensity information, and the focusing error, tracking error, and circumferential error of the optical head assembly 63.

[0148] In this way, the processor 642 can determine the focusing error, tracking error, and circumferential error of the optical head assembly according to this corresponding relationship, and according to the difference between the light intensity corresponding to a certain reference data point in the first light intensity information and the light intensity corresponding to this reference data point in the second light intensity information.

[0149] Then, when the focusing error determined by the processor 642 is greater than or equal to the second preset threshold, the processor 642 can generate a focusing servo signal according to the determined adjustment direction of the optical head 633 and the determined focusing error, and this focusing servo signal is used to indicate to adjust the position of the optical head 633 in the axial direction of the optical head 633. It should be understood that when the reference signal is the reference signal of at least three reference data points, the focusing servo signal includes at least three focusing servo signals corresponding to the reference data points. For example, the focusing servo signal can include the focusing servo signal corresponding to data reference point 1, the focusing servo signal corresponding to data reference point 2, and the focusing servo signal corresponding to data reference point 3, etc.

[0150] Optionally, the processor 633 can preset the corresponding relationship between different focusing errors and the adjustment amount of the adjustment of the optical head 633, and this corresponding relationship can be determined in advance according to a large number of experiments, and no specific limitation is made here.

[0151] When the tracking error determined by the processor 642 is greater than or equal to a third preset threshold, the processor 642 may generate a tracking servo signal according to the determined adjustment direction of the optical head 633 and the determined tracking error. The tracking servo signal is used to indicate adjusting the position of the optical head 633 in a direction perpendicular to the axial direction of the optical head 633. It should be understood that when the reference signal is a reference signal of at least three reference data points, the tracking servo signal includes at least three tracking servo signals corresponding to the reference data points. For example, the tracking servo signal may include the tracking servo signal corresponding to data reference point 1, the tracking servo signal corresponding to data reference point 2, and the tracking servo signal corresponding to data reference point 3, etc.

[0152] Optionally, the processor 633 may preset a correspondence between different tracking errors and the adjustment amount of the optical head 633. This correspondence may be determined in advance based on a large number of experiments, and no specific limitation is made thereto.

[0153] When the circumferential error determined by the processor 642 is greater than or equal to a fourth preset threshold, the processor 642 may generate a circumferential servo signal according to the determined adjustment direction of the optical head 633 and the determined circumferential error. The circumferential servo signal is used to indicate adjusting the circumferential angle of the first group of optical signals.

[0154] Optionally, the processor 633 may preset a correspondence between different axial errors and the adjustment amount of the SLM 631. This correspondence may be determined in advance based on a large number of experiments, and no specific limitation is made thereto.

[0155] Among them, the present application embodiment does not specifically limit the values of the above-mentioned second preset threshold, third preset threshold, and fourth preset threshold.

[0156] Then, after the processor 632 can generate a focusing servo signal corresponding to at least three reference data points, the focusing servo signal is sent to the voice coil motor disposed on the optical head 633 and corresponding to the at least three reference data points, so that the voice coil motor adjusts the coil current in the voice coil motor according to the received focusing servo signal, thereby adjusting the position of the optical head 633 in the axial direction of the optical head 633. For example, Figure 10 adjust the position of the optical head 633 in the z-axis direction shown in (c) of

[0157] Specifically, in combination with Figure 10 , the voice coil motor 1041 can receive the focusing servo signal 1 of the reference data point 1001 and adjust the magnitude of the coil current in the voice coil motor 1041 according to the focusing servo signal 1, thereby Figure 10Adjust the position of the optical head 633 in the z-axis direction as shown in (c) therein. Similarly, the voice coil motor 1042 can receive the focusing servo signal 2 of the reference data point 1002, and adjust the magnitude of the coil current in the voice coil motor 1042 according to the focusing servo signal 2, so as to Figure 10 Adjust the position of the optical head 633 in the z-axis direction as shown in (c) therein. The voice coil motor 1043 can receive the focusing servo signal 3 of the reference data point 1003, and adjust the magnitude of the coil current in the voice coil motor 1043 according to the focusing servo signal 3, so as to Figure 10 Adjust the position of the optical head 633 in the z-axis direction as shown in (c) therein.

[0158] It should be understood that when the voice coil motor 1041, the voice coil motor 1042, and the voice coil motor 1043 receive the corresponding focusing servo signals, they can simultaneously Figure 10 Adjust the position of the optical head 633 in the z-axis direction as shown in (c) therein, or can separately Figure 10 Adjust the position of the optical head 633 in the z-axis direction as shown in (c) therein. The embodiments of the present application do not limit this.

[0159] In this way, the optical head 633 can achieve the purpose of adjusting the position of the optical head 633 in its axial direction.

[0160] Next, when the processor 632 can generate the tracking servo signals corresponding to at least three reference data points, send the tracking servo signals to the voice coil motors arranged on the optical head 633 and corresponding to the at least three reference data points, so that the voice coil motors adjust the coil current in the voice coil motors according to the received focusing servo signals, so as to adjust the position of the optical head 633 in the direction perpendicular to the axial direction of the optical head 633, such as Figure 10 Adjust the position of the optical head 633 in the x-axis and y-axis directions as shown in (d) therein.

[0161] Here, for the specific process of the voice coil motor adjusting the position of the optical head 633 according to the tracking servo signal, reference can be made to the description of the voice coil motor adjusting the position of the optical head 633 according to the focusing servo signal above, which will not be elaborated here.

[0162] Then, when the processor 632 can generate the circumferential servo signal, send the circumferential servo signal to the rotating motor 632 for setting the SLM 631, so that the rotating motor 632 rotates by a corresponding angle according to the received circumferential servo signal, so as to adjust the circumferential angle of the SLM 631 in the plane perpendicular to the axial direction of the optical head 633, such as Figure 10 Adjust the circumferential angle of the SLM 631 in the plane formed by the x-axis and y-axis as shown in (d) therein, so as to achieve the purpose of adjusting the circumferential angle of the first group of optical signals.

[0163] Alternatively, after generating the circumferential servo signal, the processor 632 may send the circumferential servo signal to the SLM 631 to enable the SLM 631 to adjust the algorithm, thereby achieving the purpose of adjusting the circumferential angle of the first group of optical signals. The embodiments of the present application do not make specific limitations on this.

[0164] It can be understood that generally, the servo system first performs servo on the focusing error of the optical head assembly. In this way, when the first group of optical signals act on the next data block of the currently read data block, the focal plane formed by the foci of each optical signal in the first group of optical signals can overlap with the surface of the optical storage medium, that is, the focusing error of the optical head assembly is eliminated.

[0165] Then, the servo system performs servo on the tracking error and circumferential error of the optical head assembly to eliminate the tracking error and circumferential error of the optical head assembly. Among them, the embodiments of the present application do not make specific limitations on the timing of the servo system performing servo on the tracking error of the optical head assembly and performing servo on the circumferential error of the optical head assembly.

[0166] In this way, through the above servo system 60, the servo addressing problem can be efficiently achieved when reading data through an array beam including multiple optical signals.

[0167] It should be noted that Figure 6 The servo system 60 shown only shows the core devices / modules of the servo system 60, Figure 6 The shown structure does not constitute a limitation on the servo system 60. In addition to Figure 6 the shown devices / modules, the servo system 60 may include more or fewer devices or modules than shown, or different device / module arrangements, etc. For example, the above servo system 60 may further include a connection circuit between the processor 642 and the rotating motor 632, and a connection circuit between the processor 642 and the voice coil motor, etc., which will not be elaborated here.

[0168] Next, with reference to the accompanying drawings, the servo method provided by the embodiments of the present application will be described.

[0169] Referring to Figure 14 Figure 14 shows a schematic flowchart of the servo method provided by the embodiments of the present application. This method is applied to Figure 6 the servo system 60 shown, and this method may include the following steps:

[0170] S101. The servo system acts the first group of optical signals on multiple data points of the optical storage medium to obtain a second group of optical signals. Among them, the second group of optical signals includes reference signals of at least three reference data points and data signals of the data points to be read.

[0171] ​Among them, the relevant descriptions of the first group of optical signals and the second group of optical signals can refer to the relevant descriptions in the optical head assembly 63 above, which will not be elaborated here.

[0172] S102. The servo system determines a servo control signal according to the above reference signal and the preset information of the at least three reference data points.

[0173] Among them, the specific description of the at least three reference data points can refer to the relevant descriptions of the at least three reference data points above. The description of the preset information of the at least three reference data points can refer to the description of the preset information of the at least three reference data points above. The specific process of the servo system determining the servo control signal according to the reference signal and the preset information of the at least three reference data points can refer to the description of generating the focusing servo signal, the tracking servo signal, and the circumferential servo signal in the servo control signal above. This will not be elaborated in the embodiments of the present application.

[0174] S103. The servo system adjusts the position of the optical head assembly in the servo system according to the determined servo control signal.

[0175] Among them, the description of the optical head assembly in the servo system can refer to the above, which will not be elaborated here.

[0176] Specifically, adjusting the position of the optical head assembly in the servo system means adjusting the position of the optical head in the axial direction of the optical head in the optical head assembly, adjusting the position of the optical head in the direction perpendicular to the axial direction, and adjusting the circumferential angle of the SLM in the optical head assembly in the plane perpendicular to the axial direction.

[0177] Specifically, the servo system can adjust the position of the optical head in the axial direction of the optical head according to the focusing servo signal in the servo control signal. The servo system can also adjust the position of the optical head in the direction perpendicular to the axial direction of the optical head according to the tracking servo signal in the servo control signal. The servo system can also adjust the circumferential angle of the SLM in the optical head assembly in the plane perpendicular to the axial direction of the optical head according to the circumferential servo signal in the servo control signal.

[0178] Among them, the detailed process of the servo system adjusting the position of the optical head in the axial direction of the optical head, adjusting the position of the optical head in the direction perpendicular to the axial direction, and adjusting the circumferential angle of the SLM in the optical head assembly in the plane perpendicular to the axial direction can refer to the description of the voice coil motor adjusting the position of the optical head and the rotary motor adjusting the circumferential angle of the SLM above, which will not be elaborated here.

[0179] In summary, the embodiments of the present application provide a servo system and method. When writing data on an optical storage medium using an array beam including multiple optical signals (i.e., the third group of optical signals), at least three reference data points are written, and the at least three reference data points can be used to determine a plane. In this way, when reading data by acting on the optical storage medium with an array beam including multiple optical signals (i.e., the first group of optical signals), a servo control signal can be generated based on the light intensity information and spot information of the optical signals (i.e., the reference signals in the second group of optical signals) fed back after the corresponding optical signals in the first group of optical signals act on the at least three reference data points. Then, the servo system can perform servo on the optical head assembly according to the servo control signal, thus effectively solving the servo addressing problem in multi-focus parallel data reading based on the array beam.

[0180] In addition, in the servo system provided by the embodiments of the present application, the reference signal for determining the servo control signal and the data signal of the data to be read can be processed by different photoelectric detection units respectively. In this case, compared with the prior art where it is necessary to extract the servo optical signal from the data signal according to the frequency, the solution provided by the embodiments of the present application is simpler and more efficient.

[0181] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A servo system, characterized in that, include: An optical head assembly, used to generate a first group of optical signals, and used to apply the first group of optical signals to a plurality of data points on an optical storage medium to obtain a second group of optical signals; wherein the first group of optical signals includes a plurality of optical signals, and the second group of optical signals includes reference signals of at least three reference data points and data signals of data points to be read; A signal processing device is used to receive the second group of optical signals and obtain a servo control signal according to the reference signal and preset information of the at least three reference data points, wherein the servo control signal is used to adjust the position of the optical head assembly.

2. The servo system according to claim 1, characterized in that, The optical head assembly comprises an optical head, a voice coil motor is arranged on the optical head, and the servo control signal comprises a focus servo signal; The voice coil motor is used to receive the focus servo signal and adjust the coil current in the voice coil motor according to the focus servo signal to adjust the position of the optical head in the axial direction of the optical head.

3. The servo system according to claim 2, wherein The optical head assembly further includes a spatial light modulator and a rotary motor connected to the spatial light modulator, and the servo control signal further includes a circumferential servo signal; The spatial light modulator is used to generate the first group of optical signals; The rotary motor is used to receive the circumferential servo signal and adjust the rotary motor according to the circumferential servo signal to adjust the circumferential angle of the spatial light modulator.

4. The servo system according to claim 2 or 3, characterized in that, The servo control signal also includes a tracking servo signal; The optical head is also used to receive the tracking servo signal and adjust the current of the voice coil motor in the optical head according to the tracking servo signal to adjust the position of the optical head in a direction perpendicular to the axial direction of the optical head.

5. The servo system according to any one of claims 1 to 3, characterized in that The signal processing device comprises: a detector, configured to receive the second group of optical signals, and obtain light intensity information and light spot information of the reference signal in the second group of optical signals; The processor determines the servo control signal based on the light intensity information and the light spot information of the reference signal and the preset information of the at least three reference data points, wherein the preset information of the at least three reference data points includes the light intensity information and the light spot information of the at least three reference data points.

6. The servo system according to any one of claims 1-3, characterized in that At least three voice coil motors are arranged on the optical head, the number of the reference data points corresponds to the number of the voice coil motors, and the positions of the reference data points correspond to the positions of the voice coil motors.

7. A servo method, characterized in that, The method is applied to a servo system, the servo system includes an optical head assembly, and the method includes: Applying a first group of optical signals to a plurality of data points of an optical storage medium to obtain a second group of optical signals, wherein the first group of optical signals comprises a plurality of optical signals, and the second group of optical signals comprises reference signals of at least three reference data points and data signals of data points to be read; Determining a servo control signal according to the reference signal and preset information of the at least three reference data points; The position of the optical head assembly is adjusted according to the servo control signal.

8. The method according to claim 7, wherein The optical head assembly includes an optical head, the servo control signal includes a focus servo signal; and adjusting the position of the optical head assembly according to the servo control signal includes: Adjust the current of the voice coil motor in the optical head according to the focusing servo signal to adjust the position of the optical head in the axial direction of the optical head.

9. The method according to claim 8, wherein The servo system further includes a spatial light modulator and a rotating motor connected to the spatial light modulator, the servo control signal further includes a circumferential servo signal, and the adjusting the position of the optical head assembly according to the servo control signal further includes: Adjust the circumferential angle of the spatial light modulator by adjusting the rotating motor according to the circumferential servo signal, wherein the spatial light modulator is used to generate the first set of optical signals.

10. The method according to claim 8 or 9, characterized in that, The servo control signal further includes a tracking servo signal, and the adjusting the position of the optical head assembly according to the servo control signal further includes: Adjust the current of the voice coil motor in the optical head according to the tracking servo signal to adjust the position of the optical head in a direction perpendicular to the axial direction of the optical head.

11. The method according to any one of claims 7-9, characterized in that The determining the servo control signal according to the reference signal and the preset information of the at least three reference data points includes: Obtain the light intensity information and spot information of the reference signal; Determine the servo control signal according to the light intensity information and spot information of the reference signal, and the preset information of the at least three reference data points, wherein the preset information of the at least three reference data points includes the light intensity information and spot information of the at least three reference data points.

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