Optical storage medium, optical storage medium layering method and device

Abstract

The present application discloses an optical storage medium, an optical storage medium tracking method, and an optical storage medium tracking device, relating to the field of optical storage technology. The optical storage medium includes multiple storage layers, each of which includes: a data area for storing data, and multiple guide areas for positioning the storage layer; wherein the guide areas of the multiple storage layers form at least two non-overlapping guide units in a direction perpendicular to the multiple storage layers, and each guide unit includes partial guide areas of at least two storage layers.

Description

Technical Field

[0001] The present application relates to the field of optical storage technology, and in particular to an optical storage medium, a method for preparing an optical storage medium, and a device for preparing an optical storage medium. Background Art

[0002] With the development of information technology, the amount of computing and storage required for various types of information is growing exponentially. Consequently, optical storage technology has become widely used as a key means of information storage. To increase the storage density of optical storage, the design, manufacture, and read / write capabilities of multi-layer / ultra-multi-layer optical storage media are key technologies for high-density optical storage.

[0003] Typically, when reading or writing to multi-layer or multi-layer optical storage media, it is necessary to first determine an S-curve representing the time-varying focus error (FE) signal from each storage layer in the optical storage medium. This S-curve can then be used to locate the target storage layer. The FE signal can be determined by the reflected light signal collected by a light detector after the light signal generated by the laser head is reflected from the surface of the storage layer.

[0004] However, when an optical storage medium has a large number of storage layers, for a deep storage layer farther from the surface of the optical storage medium (i.e., the surface of the first storage layer in the optical storage medium), the light signal generated by the laser head will be severely attenuated when it passes through multiple storage layers to reach the surface of the deep storage layer due to multiple layers of obstruction. When the attenuated light signal is reflected from the surface of the deep storage layer and then passes through multiple storage layers to reach the optical detector, it will be further severely attenuated due to multiple layers of obstruction. Therefore, the intensity of the light signal reflected from the deep storage layer detected by the optical detector is usually very weak. As a result, the weak light signal detected by the optical detector makes it difficult to accurately locate the deep storage layer. Summary of the Invention

[0005] The present application provides an optical storage medium, an optical storage medium tracking method and an optical storage medium tracking device, which realizes the accurate positioning of the deep storage layer in the optical storage medium.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides an optical storage medium comprising multiple storage layers, each of the multiple storage layers comprising a data area for storing data and multiple guide areas for positioning the storage layers. The guide areas of the multiple storage layers form at least two non-overlapping guide units in a first direction, and each guide unit comprises portions of the guide areas of at least two storage layers. The first direction is perpendicular to the multiple storage layers.

[0008] The solution provided by this application, because at least two guide units are arranged non-overlappingly in the first direction, can limit the number of guide areas included in each guide unit in practical applications, thereby limiting the number of obstructed layers in the deep guide area within each guide unit. Therefore, when an S-curve for locating a storage layer is obtained based on the guide area within each guide unit, the amplitude of the FE signal obtained for drawing the S-curve is relatively strong. Therefore, there is no situation where the S-curve is inaccurately drawn due to a too weak FE signal, or the S-curve cannot be drawn due to an undetectable FE signal. Therefore, the solution provided by this application can achieve accurate positioning of each storage layer (especially the deep storage layer) in an optical storage medium.

[0009] In a possible design, a region of the plurality of storage layers that overlaps with any guide unit in the first direction is a transparent medium.

[0010] In another possible design, the guide areas of the same guide unit among the at least two guide units are overlapped in the first direction.

[0011] In another possible design, the at least two guiding units are arranged in a stepped manner in the first direction.

[0012] Through these possible design approaches, each guide unit can be free of an effective shielding layer in the first direction. Consequently, for any guide area in each guide unit, only the guide area located above that guide area in each guide unit can effectively shield and attenuate the optical signal irradiating that guide area. Therefore, when an S-curve for locating a storage layer is obtained based on the guide area in each guide unit, the amplitude of the FE signal obtained for drawing the S-curve is relatively strong. Therefore, there will be no situations where the S-curve is inaccurate due to a too-weak FE signal, or the S-curve cannot be drawn due to an undetectable FE signal. Therefore, the optical storage medium provided by the present application can accurately locate each storage layer (especially deep storage layers) in the optical storage medium.

[0013] In another possible design, the at least two guide units include a first guide unit and a second guide unit adjacent to the first guide unit, wherein the first guide area in the first guide unit and the second guide area in the second guide unit are located in the same storage layer.

[0014] In another possible design, the first guide area is the bottom-most guide area of the first guide unit, and the second guide area is the top-most guide area of the second guide unit.

[0015] These two possible designs demonstrate that any two adjacent guide units are connected end-to-end. That is, the bottom layer of the first guide unit and the first layer of the second guide unit are located in the same storage layer. This allows for easy determination of the distribution order of the multiple guide units corresponding to the multiple sub-S-curves included in the S-curve, using the S-curves corresponding to at least two guide units.

[0016] In another possible design, the plurality of storage layers include a plurality of groups of guide units distributed on the moving track of the optical storage medium, wherein one group of guide units in the plurality of groups of guide units includes at least two guide units.

[0017] In another possible design, the plurality of guide units are located at the edge and / or middle of the optical storage medium.

[0018] These two possible design approaches can easily address the problem of accurately positioning storage layers in scenarios where the optical storage medium's manufacturing process prevents each storage layer from being perfectly parallel. Specifically, by providing multiple sets of guide units at different locations on the optical storage medium, the guide units at each location can be used only for positioning the storage layer during reading and writing operations near that location, thereby achieving accurate positioning of the storage layer at any location on the optical storage medium.

[0019] In another possible design, all guide areas belonging to one guide unit among the at least two guide units correspond to wobble signal grooves having the same extension track.

[0020] In another possible design, the above-mentioned optical storage medium includes a swing signal groove structure layer, which is provided with a swing signal groove corresponding to each guide unit; or, all guide areas belonging to a guide unit are provided with a swing signal groove corresponding to the guide unit.

[0021] Through these two possible design methods, since each guide area corresponds to a corresponding swing signal groove, after positioning the target storage layer, the optical signal can move smoothly from the guide area of the target storage layer to the data area, thereby realizing reading / writing of the data area of the target storage layer.

[0022] In a second aspect, the present application provides a method for tracking layers of an optical storage medium, the method comprising: obtaining a first S-reference curve. When it is determined that a tracking error occurs when reading or writing data in a data area for storing data in a first storage layer among multiple storage layers, the position of an optical head in a first direction is adjusted according to the first S-reference curve to achieve correct tracking of the first storage layer. The first S-reference curve is determined based on multiple focus error (FE) signals obtained after an optical signal continuously scans guide areas on multiple storage layers in the optical storage medium in a first direction, wherein the first direction is perpendicular to the multiple storage layers, and the guide areas on the multiple storage layers include the guide area of the first storage layer.

[0023] The solution provided by this application utilizes a first S-reference curve determined by multiple focus error (FE) signals obtained by continuously scanning guide areas on multiple storage layers of an optical storage medium in a direction perpendicular to the multiple storage layers based on an optical signal. This allows accurate positioning of the storage layers of the optical storage medium. Therefore, when a tracking error occurs during reading or writing to the first storage layer, the first storage layer can be directly positioned using the first S-reference curve. Compared to solutions that require rescanning to obtain the S-curve of the data area after a tracking error, the solution of this application improves the efficiency of storage layer positioning while maintaining accurate positioning.

[0024] In one possible design, when it is determined that a layer tracking error occurs when reading / writing data from a data area for storing data in a first storage layer among the multiple storage layers, adjusting the position of the optical head in the first direction based on a first S-reference curve to achieve correct layer tracking of the first storage layer includes: when it is determined that a layer tracking error occurs when reading / writing data from a data area for storing data in the first storage layer among the multiple storage layers, obtaining a first S-curve. Then, based on the first S-reference curve and the first S-curve, adjusting the position of the optical head in the first direction to achieve correct layer tracking of the first storage layer. The first S-curve is determined based on multiple FE signals obtained after the optical signal continuously scans the data areas on the multiple storage layers in the first direction.

[0025] In another possible design, adjusting the position of the optical head in the first direction based on the first S-reference curve and the first S-curve to achieve accurate tracking of the first storage layer includes determining a phase difference between the first S-curve and the first S-reference curve indicating zero-crossing points of the same storage layer. If the phase difference is less than a preset threshold, adjusting the position of the optical head in the first direction based on the first S-curve to achieve accurate tracking of the first storage layer. If the phase difference is greater than the preset threshold, terminating reading or writing to the first storage layer.

[0026] These two possible designs enable the use of the first S-reference curve as a valid reference curve for the first S-curve corresponding to the newly acquired data area after a tracking error occurs during reading or writing to the first storage layer, thereby determining whether the first S-curve can correctly locate the storage layer. This avoids the problem of storage layer tracking errors caused by an invalid first S-curve.

[0027] In a third aspect, the present application provides a tracking device for an optical storage medium, the device comprising: an acquisition unit for acquiring a first S-reference curve; a control unit for, upon determining that a tracking error occurs when reading / writing data from a data area for storing data in a first storage layer among multiple storage layers, controlling and adjusting the position of an optical head in a first direction according to the first S-reference curve to achieve correct tracking of the first storage layer. The first S-reference curve is determined based on multiple focus error (FE) signals obtained after an optical signal continuously scans guide areas on multiple storage layers in the optical storage medium in a first direction, wherein the first direction is perpendicular to the multiple storage layers, and the guide areas on the multiple storage layers include the guide area of the first storage layer.

[0028] In one possible design, the acquisition unit is further configured to acquire a first S-curve when determining that a layer tracking error occurs when reading or writing data from a data area for storing data in a first storage layer among the multiple storage layers. The control unit is specifically configured to control and adjust the position of the optical head in the first direction based on the first S-reference curve and the first S-curve to achieve correct layer tracking of the first storage layer. The first S-curve is determined based on multiple FE signals obtained after the optical signal continuously scans the data areas on the multiple storage layers in the first direction.

[0029] In another possible design, the apparatus further includes a determining unit configured to determine a phase difference between the first S-curve and the first S-reference curve, indicating zero-crossing points in the same storage layer. The control unit is configured to, if the phase difference is less than a preset threshold, adjust the position of the optical head in the first direction according to the first S-curve to achieve accurate tracking of the first storage layer. The control unit is further configured to terminate reading or writing to the first storage layer if the phase difference is greater than a preset threshold.

[0030] It can be understood that the description of the beneficial effects of the third aspect and any possible design method thereof can refer to the description of the beneficial effects brought about by any possible design method in the second aspect, and will not be repeated here.

[0031] In a fourth aspect, the present application provides a follower device for an optical storage medium, the device comprising: a transmission interface and one or more processors, the one or more processors receiving or sending data through the transmission interface, the one or more processors being configured to call program instructions stored in a memory to execute any of the methods provided in the second aspect and any possible design thereof.

[0032] In a fifth aspect, the present application provides a computer-readable storage medium comprising program instructions, which, when executed on a computer or processor, enables the computer or processor to execute any of the methods provided in the second aspect and any possible design thereof.

[0033] In a sixth aspect, the present application provides a computer program product, which, when run on a backing device of an optical storage medium, enables any method provided by any possible implementation manner in the second aspect to be executed.

[0034] It can be understood that any of the above-mentioned devices, computer storage media or computer program products can be applied to the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods and will not be repeated here.

[0035] In this application, the name of the optical storage medium backing layer device does not limit the device or functional module itself. In actual implementation, these devices or functional modules may appear with other names. As long as the functions of each device or functional module are similar to those of this application, they fall within the scope of the claims of this application and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of a data reading and writing system for reading and writing optical storage media;

[0037] Figure 2 A schematic diagram of obtaining an S-curve of any storage layer;

[0038] Figure 3 A schematic diagram of an S-curve with regular transitions corresponding to multiple storage layers included in an optical storage medium;

[0039] Figure 4 A schematic structural diagram of an optical storage medium provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the effect of an S-curve corresponding to two guide units formed by guide areas on multiple storage layers in an optical storage medium provided by an embodiment of the present application;

[0041] Figure 6A schematic diagram of a guide area on a storage layer of an optical disc and a guide unit formed by the guide area provided in an embodiment of the present application;

[0042] Figure 7 A schematic diagram of a plurality of guide units distributed at the inner edge or middle position of an optical disc provided in an embodiment of the present application;

[0043] Figure 8 A schematic diagram of an embodiment of the present application showing multiple groups of guide units distributed at the inner edge and middle of an optical disc;

[0044] Figure 9 A schematic diagram of a process for forming a layer of an optical storage medium according to an embodiment of the present application;

[0045] Figure 10 A schematic structural diagram of a heel layer device for an optical storage medium provided in an embodiment of the present application;

[0046] Figure 11 A schematic structural diagram of a signal-carrying medium for carrying a computer program product provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0048] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0049] It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the listed items. The term "and / or" describes an association between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this application generally indicates that the associated objects are in an "or" relationship.

[0050] It should be understood that references throughout this specification to "one embodiment," "an embodiment," or "one possible implementation" mean that specific features, structures, or characteristics associated with that embodiment or implementation are included in at least one embodiment of this application. Therefore, the appearance of "in one embodiment," "in an embodiment," or "one possible implementation" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0051] refer to Figure 1 , Figure 1 A data reading and writing system for reading and writing data from an optical storage medium is shown. The data reading and writing system may include an optical path module 11 and a control module 12. The optical path module 11 is configured to generate optical signals for reading and writing data from an optical storage medium 10 under the control of the control module 12. The optical storage medium 10 includes multiple storage layers. For example, the optical storage medium 10 is an optical disc including multiple storage layers.

[0052] It is understood that the optical signal generated by the optical path module 111 for reading from / writing to the optical storage medium 10 can be a single optical signal or an array of multiple optical signals, and this embodiment of the present application is not limited thereto. It should be understood that if the optical signal is an array of multiple optical signals, each of the multiple optical signals is used to read from / write to a single data point on the optical storage medium 10.

[0053] Optionally, the optical path module 11 may include a light source 111, an optical modulator 112, a spatial optical path component 113, and an optical head 114, and the control module 12 may include a main controller 121, a servo controller 122, an optical signal detector 123, an optical head servo driver 124, and an optical storage medium servo driver 125, etc.

[0054] Specifically, the light source 111 is used to generate an initial optical signal for reading / writing data. The light source 111 can be a laser light source, etc., which is not limited.

[0055] The optical modulator 112 is connected to the main controller 121 and can modulate the initial optical signal received from the light source 111 into an optical signal that corresponds one-to-one with the data to be written, or into an optical signal with a preset power for reading data, based on a signal instruction sent by the main controller 121. It should be understood that when the optical signal used for writing data acts on the optical storage medium 10, it will change the physical / chemical properties of the optical storage medium 10, while when the optical signal used for reading data acts on the optical storage medium 10, it will not change the physical / chemical properties of the optical storage medium 10.

[0056] During the data writing process, the main controller 121 receives input data to be written and, after encoding the data at an encoder (not shown), controls the optical modulator 112 to modulate the initial optical signal into an optical signal capable of generating, on the optical storage medium 10, an optical signal with physical / chemical properties corresponding to the data to be written. Specifically, the optical modulator 112 modulates the initial optical signal into an optical signal that corresponds one-to-one with the data to be written. The encoder is strongly correlated with the characteristics of the optical storage medium 10 and records the correspondence between the data and the physical / chemical properties of the optical storage medium 10.

[0057] The spatial optical path component 113 can be configured to transmit the optical signal received from the optical modulator 112, receive the reflected optical signal from the optical storage medium 10, and reflect the reflected optical signal to the optical signal detector 123. The reflected optical signal is used to determine the read data and to obtain a servo signal. For example, the functions of the spatial optical path component 113 can be implemented using a beam splitter, which is not described in detail here.

[0058] The optical head 114 is used to receive the optical signal transmitted by the spatial optical path component 113 and focus the optical signal so that it acts on the optical storage medium 10. When the optical signal acting on the optical storage medium 10 is used to write data, this process achieves data writing. When the optical signal acting on the optical storage medium 10 is used to read data, the optical storage medium 10 reflects the optical signal. Furthermore, the reflected optical signal from the optical storage medium 10 can reach the spatial optical path component 113 via the optical head 114, and then be reflected by the spatial optical path component 113 to the optical signal detector 123.

[0059] In this way, the optical signal detector 123 can receive the reflected light signal reflected by the spatial optical path component 113 and detect the light intensity information of the reflected light signal. The decoder (and the main controller 121, not shown) can then decode the light intensity information detected by the optical signal detector 123 to determine the read data. The main controller 121 then outputs the read data.

[0060] The optical signal detector 123 includes a charge coupled device (CCD). In addition, the decoder records the correspondence between different light intensities and the physical / chemical properties of the optical storage medium 10, as well as the correspondence between different physical / chemical properties and data.

[0061] In addition, the optical signal detector 123 may also include a four-quadrant detector. The four-quadrant detector can collect signal values of the four quadrants A, B, C, and D based on the reflected light signal received from the optical storage medium 10. In this way, the servo controller 122 connected to the four-quadrant detector can calculate the focus error (FE) value by (A+B)-(B+D) based on the collected signal values of the four quadrants. It can be understood that this process is the process of obtaining the FE value based on the phase dispersion method. Here, the embodiment of the present application does not specifically explain the phase dispersion method and the four-quadrant detector.

[0062] The FE value indicates the distance between the focal point of an optical signal acting on any storage layer in the optical storage medium 10 and the surface of the storage layer. When the distance is 0, the FE value is 0, indicating that the optical signal is correctly focused on the storage layer, that is, the focal point of the optical signal and the surface of the storage layer coincide. When the distance is greater than 0, it indicates that the optical signal is not correctly focused on the storage layer, that is, the focal point of the optical signal and the surface of the storage layer do not coincide.

[0063] In this way, the servo controller 122 can determine a focus servo control signal based on the obtained FE value and send the focus servo signal to the optical head servo driver 124. The optical head servo driver 124 can then adjust the position of the optical head 114 along the optical axis of the optical head 114 based on the received focus servo signal, thereby ensuring that the optical signal focused by the optical head 114 and used to read / write the optical storage medium 10 is correctly focused on the storage layer of the optical storage medium 10. It can be understood that this process implements focus servo on the optical signal in the axial direction.

[0064] In addition, in a possible implementation, a wobble signal groove structure is provided in the optical storage medium 10 , and the wobble structure is used to locate data points within the plane of the optical storage medium 10 , thereby realizing radial servo of the optical signal within the plane of the optical storage medium 10 .

[0065] In this case, the optical signal acting on the optical storage medium 10, after being reflected by the optical storage medium 10, can carry frequency information indicating the wobble structure. Therefore, the optical signal detector 123 can also determine the frequency information carried by the optical signal in the reflected optical signal received from the optical storage medium 10. In this way, the servo controller 122 can determine a radial servo signal based on the frequency information carried by the optical signal and send the radial servo signal to the optical head servo driver 124 and / or the optical storage medium servo driver 125. The optical head servo driver 124 can then adjust the position of the optical head 114 in a direction perpendicular to the optical axis of the optical head 114 (i.e., within the plane of the optical storage medium 10) based on the received radial servo signal, and / or the optical storage medium servo driver 125 can adjust the position of the optical storage medium 10 within the plane of the optical storage medium 10 based on the received radial servo signal, thereby ensuring that the optical signal used to read / write the optical storage medium 10 correctly acts on the position to be read / written in the optical storage medium 10.

[0066] It should be noted that, on the one hand, in the data reading and writing system (such as Figure 1 Before the data reading and writing system (shown in FIG. 1 ) reads or writes any storage layer in the optical storage medium, the data reading and writing system needs to determine the target storage layer based on the S curve obtained after scanning the optical storage medium layer by layer. Figure 1 When a layer tracking error (e.g., layer jump) occurs during reading / writing of any storage layer of an optical storage medium by a data read / write system (e.g., a data read / write system shown in FIG2 ), the data read / write system needs to re-determine the position of the target storage layer based on the S-curve obtained by rescanning the optical storage medium 10 layer by layer, thereby achieving layer tracking during reading / writing of the optical storage medium. The S-curve is a graph showing the temporal variation of the FE value calculated based on the optical signal reflected from the optical storage medium 10 during the layer-by-layer scanning of the optical signal on the optical storage medium 10. The S-curve is described in detail below.

[0067] As can be seen from the above description, for any storage layer in an optical storage medium, when the optical signal is correctly focused on that storage layer, the FE value calculated based on the optical signal reflected from that storage layer is 0. When the optical signal is not correctly focused on that storage layer, the FE value calculated based on the optical signal reflected from that storage layer is not 0. It should also be noted that when the distance between the focal point of the optical signal and that storage layer is sufficiently far, the FE value is also 0.

[0068] It can be understood that when the focus of the optical signal moves along the optical axis toward the selected storage layer and continues to move in the original direction after focusing on the surface of the selected storage layer, the FE value calculated based on the reflected light signal of the selected storage layer undergoes a transition from zero to positive to zero to negative to zero. A zero value between positive and negative values indicates that the optical signal is correctly focused on the surface of the selected storage layer, i.e., the focus of the optical signal coincides with the surface of the selected storage layer.

[0069] For example, combined with Figure 1 The main controller 121 can control the optical head 114 to move along the optical axis, so that the focus of the optical signal after being focused by the optical head 114 moves from a position farther away from any storage layer in the optical storage medium 10 to the any storage layer, and continues to move along the original direction after the focus coincides with the any storage layer.

[0070] During this process, the four-quadrant detector samples the optical signal reflected from any storage layer at a predetermined frequency. The servo controller 122 then calculates an FE value based on the signal values from the four quadrants A, B, C, and D sampled at each time. Furthermore, the servo controller 122 can plot an S-curve based on the temporal evolution of the multiple FE values calculated after multiple samplings. A zero-crossing point in the S-curve (i.e., a point between the positive and negative FE values where the FE value is 0) indicates that the optical signal is correctly focused on that particular storage layer.

[0071] Exemplary, reference Figure 2 , Figure 2 A schematic diagram of obtaining an S-curve of any storage layer is shown.

[0072] refer to Figure 2 In (a), as the optical head moves along direction 1, the focus of the optical signal after being focused by the optical head also moves along direction 1. During this process, the four-quadrant detector samples the optical signal reflected by the storage layer 20 at a predetermined frequency. The signal value obtained from each sampling is used to calculate an FE value. In this way, based on the multiple FE values calculated after multiple samplings, an S-curve can be drawn to represent the change of the FE value over time, for example Figure 2 The S-curve 21 shown in (b) in FIG. 1 , wherein the x-axis represents the sampling time t and the y-axis represents the FE value.

[0073] like Figure 2 As shown in (b), point A is the point with the largest positive FE value in the S-curve 21, and the corresponding spot shape of the light signal formed on the storage layer 20 is Figure 2 The vertical elliptical shape shown in (b) in FIG. 1 indicates that the optical signal is not correctly focused on the storage layer 20. The focus of the optical signal is Figure 2The focus fa shown in (a) in FIG.

[0074] Point C is the point with the maximum negative FE value in the S-curve 21. The corresponding spot shape of the light signal formed on the storage layer 20 is: Figure 2 The horizontal elliptical shape shown in (b) in FIG. 1 indicates that the optical signal is not correctly focused on the storage layer 20. The focus of the optical signal is Figure 2 The focus fc shown in (a).

[0075] Point B is the zero-crossing point between the positive FE value point and the negative FE value point in the S-curve 21. The corresponding spot shape of the optical signal formed on the storage layer 20 is: Figure 2 That is, the optical signal is correctly focused on the storage layer 20, that is, the focus of the optical signal is Figure 2 The focus fb shown in (a).

[0076] In this way, for an optical storage medium including multiple storage layers, by controlling the optical head to move in its axial direction a distance greater than the thickness of all storage layers in the optical storage medium, an S curve with regular jumps corresponding to the multiple storage layers can be obtained.

[0077] refer to Figure 3 , Figure 3 A schematic diagram of an S-curve with regular jumps corresponding to the multi-layer storage layer included in the optical storage medium is shown. Figure 3 As shown in FIG, the optical storage medium includes five storage layers, namely storage layers c1, c2, c3, c4 and c5. Storage layer c1 is the first storage layer of the optical storage medium (i.e., the first storage layer located on the surface side of the optical storage medium), and storage layer c5 is the bottommost storage layer of the optical storage medium (i.e., the first storage layer located on the substrate side of the optical storage medium). Figure 3 The xy plane in the coordinate system shown is a plane parallel to the optical storage medium, and the z-axis direction is a direction perpendicular to the optical storage medium.

[0078] In the actual application of reading and writing data, Figure 3 The optical storage medium shown can move in the positive direction along the x-axis. Thus, when the optical head moves in the positive direction along the z-axis, the optical signal focused by the optical head can scan the storage layers c1, c2, c3, c4 and c5 layer by layer.

[0079] When the optical signal scans the five storage layers layer by layer, the four-quadrant detector can sample the optical signal reflected by the storage layer of the optical storage medium multiple times at a predetermined frequency, and the signal values of the multiple samples can be calculated to obtain multiple FE values. In this way, the curve of the multiple FE values changing with time is: Figure 3 The S-curve 30 shown has regular transitions.

[0080] in, Figure 3 The illustrated S-curve 30 includes multiple sub-S-curves with different amplitudes. The zero crossing of each sub-S-curve indicates that the optical signal is correctly focused on a storage layer. Therefore, the zero crossing of each sub-curve corresponds to a correctly focused storage layer. For example, zero crossing A1 corresponds to the correctly focused storage layer C1.

[0081] In practical applications, a servo controller or main controller can record the z-axis position of the optical head at each sampling moment of the four-quadrant detector. Thus, for each zero-crossing point in the S-curve 30, the servo controller or main controller records a corresponding z-axis position of the optical head. When the optical head is at the position recorded at the sampling moment corresponding to any zero-crossing point, the optical head can accurately focus the optical signal on the storage layer corresponding to that zero-crossing point. This achieves the purpose of finding a layer among the multiple storage layers of the optical storage medium based on the S-curve, that is, locating a storage layer can be achieved based on each zero-crossing point in the S-curve.

[0082] It can be understood that when the optical storage medium and the optical head are moving at a uniform speed, the intervals between any two adjacent zero-crossing points in the S-curve obtained by scanning the entire storage layer of the optical storage medium layer by layer with the optical signal focused by the optical head are equal. Figure 3 The interval between the zero crossing points A1 and B1 and the interval between the zero crossing points B1 and C1 are shown to be equal.

[0083] It should also be understood that when the optical storage medium moves in the positive direction along the x-axis and the optical head moves in the positive direction along the z-axis, the focal points of the optical signal focused by the optical head on different storage layers in the optical storage medium are located at Figure 3 The intersection of the track 1 and each storage layer is shown. Moreover, the focus on the track 1 corresponds to the first group of sub-S curves in the S curve 30 (the group of sub-S curves on the left in the S curve 30). When the optical storage medium moves in the positive direction along the x-axis and the optical head moves in the negative direction along the z-axis, the focus of the optical signal focused by the optical head on different storage layers in the optical storage medium is located as shown in FIG. Figure 3 The intersection of the track 2 and each storage layer is shown. Moreover, the focus on the track 2 corresponds to the second group of sub-S curves in the S curve 30 (the right group of sub-S curves in the S curve 30).

[0084] It should also be understood that when the optical signal focused by the optical head scans multiple storage layers layer by layer, the phase difference of the zero-crossing points corresponding to different storage layers based on the reference point is different. The phase difference value between any zero-crossing point and the reference point is only related to the number of storage layers between the storage layer corresponding to any zero-crossing point and the storage layer corresponding to the reference point. The reference point can be any zero-crossing point in the S-curve, that is, any zero-crossing point in the S-curve can be set as a reference point, which is not limited in the embodiment of the present application. For example, the reference point of the S-curve 30 can be Figure 3 The zero-crossing point A1 shown here, or the zero-crossing point B1, can also be the zero-crossing point C1, without limitation. Therefore, after obtaining S-curves corresponding to multiple storage layers in an optical storage medium, the phase difference value of any zero-crossing point in the S-curve relative to a reference point can be associated with the storage layer corresponding to that zero-crossing point.

[0085] Depend on Figure 3 It can also be seen that the amplitudes of the sub-S curves corresponding to different storage layers decrease as the distance between the storage layer and the first storage layer in the optical storage medium increases. In other words, the sub-S curve corresponding to the first storage layer (for example, storage layer c1) has the largest amplitude, while the sub-S curve corresponding to the lowest storage layer (for example, storage layer c5), which is the farthest away from the first storage layer, has the smallest amplitude.

[0086] This situation arises because when the optical signal is focused by the optical head on the bottommost storage layer, it must pass through multiple storage layers before reaching it. During this process, each storage layer through which the light signal passes scatters and / or reflects the light signal, causing it to attenuate before reaching the bottommost storage layer. The attenuated light signal then reflects from the bottommost storage layer, and must pass through multiple storage layers again before reaching the optical detector, further attenuating the light signal. However, for the first storage layer, the light signal can be applied directly to the first storage layer, and the light signal reflected from the first storage layer reaches the optical detector without passing through other storage layers. Therefore, during this process, the light signal is not attenuated due to obstruction. Consequently, the FE value calculated from the reflected light signal from the bottommost storage layer, as collected by the four-quadrant detector, is much smaller than the FE value calculated from the reflected light signal from the first storage layer. This means that the amplitude of the sub-S-curve corresponding to the bottom storage layer is smaller than that of the sub-S-curve corresponding to the first storage layer.

[0087] When an optical storage medium includes a large number of storage layers, the optical signal collected by the four-quadrant detector for calculating the FE value of the underlying storage layer will be relatively weak, resulting in the calculated FE value being too small or inaccurate. Consequently, the S-curve drawn based on these FE values cannot accurately locate the underlying storage layer in the optical storage medium. Alternatively, the four-quadrant detector cannot collect the optical signal used to calculate the FE value of the underlying storage layer, making it impossible to obtain the sub-S-curve corresponding to the underlying storage layer in the optical storage medium, and thus unable to locate the underlying storage layer in the optical storage medium based on the S-curve.

[0088] Based on this, an embodiment of the present application provides an optical storage medium comprising multiple storage layers, each of which includes a data area and multiple guide areas. The data area is used to store data, while the guide areas are used to obtain a clear and accurate S-reference curve, which enables accurate positioning of the storage layer. Furthermore, the S-reference curve can also serve as an effective reference curve for tracking layers during data read / write operations, effectively resolving the problem of storage layer tracking errors caused by optical signal attenuation during data read / write operations.

[0089] The data area and the guide area both have the property of partially transmitting and partially reflecting the light signal.

[0090] Specifically, the guide areas in the multiple storage layers of the optical storage medium provided in the embodiments of the present application can form at least two non-overlapping guide units in a first direction (a direction perpendicular to the multiple storage layers). Each of the at least two guide units can include a guide area on each of the at least two storage layers (i.e., each guide unit includes a portion of the guide areas of at least two storage layers). Furthermore, the guide areas belonging to the same guide unit are arranged to overlap in the first direction. In the first direction, the area in the multiple storage layers that overlaps with any of the guide units is a transparent medium. It should be understood that the transparent medium here only transmits light signals and does not reflect them.

[0091] That is, for any guide unit, both the areas above and below it in the first direction are transparent. Furthermore, because the number of overlapping guide areas within a guide unit in the first direction is limited, when an optical signal acts on the bottommost guide area within that guide unit, only the guide areas on the remaining storage layers within that guide unit, excluding the bottommost guide area, attenuate the optical signal. The transparent media above and below the guide unit only transmit the optical signal and do not reflect it, thus preventing any attenuation. Consequently, the attenuation of the optical signal upon impacting the bottommost guide area within that guide unit is extremely limited. Consequently, when the optical signal scans the at least two guide units layer by layer, the amplitude of the sub-S-curve corresponding to each guide area is relatively large, allowing the S-curve to accurately locate the storage layer.

[0092] Optionally, for the at least two boot units mentioned above, the number of boot areas included in each boot unit may be the same or different, which is not limited in this embodiment of the present application.

[0093] For simplicity, the embodiments of the present application are described below using an example in which each guide unit includes the same number of guide areas. In this case, it can be understood that if the number of guide units formed by the guide areas on multiple storage layers in the optical storage medium in the first direction is m, and the number of overlapping guide areas in each guide unit in the first direction is n, then the number of storage layers included in the optical storage medium is: (n-1)×m+1, where m and n are both positive integers.

[0094] Optionally, the at least two guiding units are arranged in a stepped manner in the first direction.

[0095] Optionally, for a first boot unit of the at least two boot units and a second boot unit adjacent to the first boot unit, the first boot area in the first boot unit and the second boot area in the second boot unit are located in the same storage layer. If the first boot unit is located above the second boot unit, the first boot area is the bottom-most boot area of the first boot unit, and the second boot area is the top-most boot area of the second boot unit, i.e., the second boot area is the first-layer boot area of the second boot unit.

[0096] As an example, refer to Figure 4 , Figure 4 FIG. 4 shows a schematic structural diagram of an optical storage medium 40 provided in an embodiment of the present application. Figure 4 As shown, the optical storage medium 40 includes 7 storage layers, namely storage layer 1, storage layer 2, storage layer 3, storage layer 4, storage layer 5, storage layer 6 and storage layer 7. Figure 4In the coordinate system shown, the xy plane is parallel to the optical storage medium 40, and the z axis is perpendicular to the multiple storage layers in the optical storage medium, that is, the z axis direction is the first direction mentioned above.

[0097] in, Figure 4 (a) in FIG. 4 shows a schematic diagram of a three-dimensional structure of the optical storage medium 40. Figure 4 As shown in (a) in FIG, each storage layer of the optical storage medium 40 includes a data area and a guide area. The guide areas of the seven storage layers of the optical storage medium 40 can form three guide units in the z-axis direction, namely, guide unit 1, guide unit 2, and guide unit 3. Among them, guide unit 1 includes three guide areas, which are divided into guide area y1 on storage layer 1, guide area y2 on storage layer 2, and guide area y3-1 on storage layer 3. Guide unit 2 includes three guide areas, which are divided into guide area y3-2 on storage layer 3, guide area y4 on storage layer 4, and guide area y5-1 on storage layer 5. Guide unit 3 includes three guide areas, which are divided into guide area y5-2 on storage layer 5, guide area y6 on storage layer 6, and guide area y7 on storage layer 7.

[0098] It can be seen that guide units 1, 2, and 3 are distributed in a stepped manner in the z-direction. Furthermore, as adjacent guide units 1 and 2, the guide area y3-1 in guide unit 1 and the guide area 3-2 in guide unit 2 are both located in storage layer 3. Specifically, guide area y3-1 is the bottom-most guide area in guide unit 1, and guide area 3-2 is the top-most guide area in guide unit 2. Similarly, as adjacent guide units 2 and 3, the guide area y5-1 in guide unit 2 and the guide area 5-2 in guide unit 3 are both located in storage layer 5. Specifically, guide area y5-1 is the bottom-most guide area in guide unit 2, and guide area 5-2 is the top-most guide area in guide unit 3. It can be seen that the guide areas of adjacent guide units are connected end to end.

[0099] Figure 4 (b) in FIG. 4 shows a cross-sectional schematic diagram of the optical storage medium 40. Figure 4 As shown in (b), the three boot areas in the boot unit 1 correspond from top to bottom Figure 4 The three guide areas in the guide unit 2 correspond to the following from top to bottom: Figure 4 The three guide areas in the guide unit 3 correspond to the following from top to bottom: Figure 4(a) shows the guide area y5-2, guide area y6, and guide area y7. The area below the guide unit 1 and overlapping with the guide unit 1 in the z-axis direction is a transparent medium. Similarly, the area above and below the guide unit 2 and overlapping with the guide unit 2 in the z-axis direction is a transparent medium. Similarly, the area above the guide unit 3 and overlapping with the guide unit 3 in the z-axis direction is a transparent medium. Figure 4 As shown by the dotted line in (b).

[0100] In this way, when the optical signal focused by the optical head acts on the bottom guide area of guide unit 3, such as guide area y7, the optical signal can pass through the transparent medium above guide unit 3, as well as guide areas y5-2 and y6 within guide unit 3, before acting on guide area y7. In this case, only guide areas y5-2 and y6 attenuate the optical signal acting on guide area y7, while the transparent medium above guide unit 3 does not attenuate the optical signal acting on guide area y7, thus limiting the attenuation of the optical signal. Furthermore, the amplitude of the S-curve obtained by scanning the guide areas of the optical storage medium layer by layer is relatively large, making this S-curve more accurate when used to locate the storage layer.

[0101] refer to Figure 5 , Figure 5 The schematic diagram shows the effect of the S curve corresponding to two guide units formed by the guide areas on multiple storage layers in an optical storage medium provided by an embodiment of the present application. Figure 5 As shown, the optical storage medium includes five storage layers, namely storage layers c1, c2, c3, c4, and c5. Furthermore, the optical storage medium moves along the positive x-axis of the coordinate system, and the optical head moves along the positive z-axis. Therefore, the focus of the optical signal focused by the optical head on the storage layer is located at the intersection of track 1 and each storage layer.

[0102] in, Figure 5 The optical storage medium shown in (a) is a common optical storage medium, that is, Figure 5 The optical storage medium shown in (a) does not distinguish between the guide area and the data area. Figure 5 The optical storage medium shown in (b) is an optical storage medium provided by an embodiment of the present application, and includes a guide area for positioning the storage layer and a data area for storing data. Figure 5 The guide area on the five storage layers of the optical storage medium shown in (b) can form two guide units in the z-axis direction, including a guide unit 1 and a guide unit 2.

[0103] like Figure 5As shown in (a) of FIG, after the optical signal focused by the optical head scans the five storage layers layer by layer along the positive direction of the z-axis, an S-curve 51 can be obtained. It should be understood that the process of obtaining the S-curve here can refer to Figure 3 The description of the process of obtaining the S-curve is omitted here.

[0104] like Figure 5 As shown in (b), the guide areas on the five storage layers of the optical storage medium form guide units 1 and 2 in the z-axis direction. The areas on the five storage layers that overlap with the guide unit 1 along the z-axis, and the areas on the five storage layers that overlap with the guide unit 2 along the z-axis are both transparent media. Figure 5 As shown by the dotted line in (a) in FIG. When the optical signal focused by the optical head scans the guide areas of the two guide units layer by layer along the positive direction of the z-axis, an S-curve 52 can be obtained. It should be understood that the process of obtaining the S-curve here can refer to Figure 3 The description of the process of obtaining the S-curve is omitted here.

[0105] It can be seen that when the optical signal focused by the optical head acts on the guide area in guide unit 2, it passes through two layers of transparent medium. These two layers of transparent medium do not attenuate the optical signal acting on the guide area in guide unit 2. Therefore, the amplitude of the S-curve corresponding to guide unit 2 (i.e., the last three sub-S-curves in S-curve 52, starting from the left side) is greater than that of the S-curves corresponding to storage layers c3, c4, and c5 in S-curve 51 (i.e., the last three sub-S-curves in S-curve 51, starting from the left side). Therefore, the S-curve corresponding to the guide unit in the optical storage medium can more accurately locate the storage layer where the guide area is located.

[0106] Refer again Figure 4 In (a), after the target storage layer is determined by obtaining the S reference curve after scanning the guide area layer by layer along the z-axis according to the optical signal, the data reading and writing system (e.g. Figure 1 The data reading and writing system shown in the figure can control the optical head along Figure 4 The optical signal moves in the direction 1 shown in (a) so that the optical signal can move to the data area, thereby achieving the purpose of reading / writing the data area of the target storage layer.

[0107] In practical applications, data reading and writing systems (such as Figure 1 When the data read / write system (shown in FIG. 1 ) reads or writes to an optical storage medium, the optical storage medium is in high-speed motion. As the data read / write system controls the optical head to move from the guide area to the data area, the optical signal's focus on the storage layer forms a specific motion trajectory based on the direction of the optical storage medium's motion. Because the guide areas within a guide unit overlap in the z-axis (i.e., the first direction), each guide unit corresponds to a specific motion trajectory, and different guide units correspond to different motion trajectories.

[0108] It should be understood that the trajectory of the optical signal as it moves from the guide area to the data area is determined by the direction and speed of movement of the optical storage medium, as well as the direction and speed of movement of the optical head. When the direction and speed of movement of the optical storage medium and the direction and speed of movement of the optical head are determined, the trajectory of the optical signal as it moves from the guide area to the data area is also determined.

[0109] It should be noted that the area that the motion trajectory of the optical signal passes through when moving from the guide area to the data area also belongs to the area range of the guide area.

[0110] For the sake of convenience, the present application embodiment will Figure 4 The guide area shown is called the first area of the guide area described in the embodiment of the present application, and the area through which the motion trajectory of the optical signal when moving from the guide area to the data area is passed is called the second area of the guide area described in the embodiment of the present application.

[0111] The guide area in the optical storage medium provided by the embodiment of the present application is further described below by taking a circular optical disc as an example. It should be understood that when the optical storage medium is a circular optical disc, the movement mode of the optical disc is usually high-speed rotation.

[0112] It should be noted that, in an optical disc, the data track is spiral-shaped. For simplicity of illustration, the data track in the following figures is illustrated as a circular ring.

[0113] refer to Figure 6 , Figure 6 A schematic diagram of a guide area on a storage layer of an optical disc 60 and a guide unit formed by the guide area is shown in an embodiment of the present application.

[0114] Figure 6 (a) in FIG. 1 shows a top view of the optical disc 60. Figure 6 As shown in (a) of FIG. 1 , multiple sets of guide units are distributed along the circumference of the optical disc 60 (i.e., the direction of the optical disc's motion trajectory) at the outer edge of the optical disc 60. It should be understood that these multiple sets of guide units typically cover the entire circumference of the optical disc 60 (for a spiral data track on an optical disc, this would be a spiral ring adjacent to each other). Each set of guide units comprises a guide area on each storage layer of the optical disc 60.

[0115] For the first group of guide units in multiple groups of guide units, for example Figure 6In the first group of guide units shown in (a), the shaded area within the first group of guide units comprises the first area of each guide zone within the first group of guide units, and the blank area within the first group of guide units comprises the second area of each guide zone within the first group of guide units. Furthermore, the area radially adjacent to the plurality of guide units on optical disc 60 is the data area of optical disc 60 for storing data.

[0116] Figure 6 (b) in FIG. 5 shows a perspective cross-sectional view of the first group of guide units in the optical disc 60. Specifically, Figure 6 (b) in FIG. 1 shows a cross-sectional view of the first region of the guide area in the first group of guide units. Figure 6 As shown in (b), the optical disc 60 includes 10 storage layers, and the guide areas on the 10 storage layers form three non-overlapping guide units in the first group of guide units in a direction perpendicular to the optical disc 60 (i.e., the first direction mentioned above), namely, guide unit 1, guide unit 2 and guide unit 3.

[0117] The guide unit 1, the guide unit 2 and the guide unit 3 are distributed in a stepped manner in the first direction, and each guide unit includes four guide areas ( Figure 6 (b) in FIG. 1 is shown by a black thick solid line). Furthermore, the top guide area of the guide unit 2 adjacent to the guide unit 1 and the bottom guide area of the guide unit 1 are located in the same storage layer. Similarly, the top guide area of the guide unit 3 adjacent to the guide unit 2 and the bottom guide area of the guide unit 2 are located in the same storage layer. In addition, in the first direction, the area overlapping with the guide unit 1, the area overlapping with the guide unit 2, and the area overlapping with the guide unit 3 in the 10 storage layers of the optical disc 60 are all transparent media. Here, the transparent media is formed by Figure 6 The dotted line shown in (b) indicates.

[0118] Figure 6 (c) in FIG. 5 shows an enlarged top view of the first group of guide units of the optical disc 60 and a data area adjacent to the first group of guide units in the radial direction of the optical disc 60. Figure 6 As shown in (c) in FIG. 1 , the first group of guide units includes guide unit 1, guide unit 2, and guide unit 3. For any guide area in each guide unit, the area of the guide area parallel to the circumference of the optical disc 60 is the first area of the guide area, and the area intersecting the circumference of the optical disc 60 is the second area of the guide area. For example, for guide area 3, area 1 of guide area 3 parallel to the circumference of the optical disc 60 is the first area of the guide area in guide unit 3, and area 2 of guide area 3 intersecting the circumference of the optical disc 60 is the second area of the guide area in guide unit 3.

[0119] In addition, if the optical disc 60 moves along direction 1, after the target storage layer is determined based on the S reference curve obtained by scanning the guide area of the optical disc 60 layer by layer along the first direction according to the optical signal, the data reading and writing system (for example Figure 1 The data reading and writing system shown in FIG. 1 can control the optical head to move in direction 2 (i.e., radial direction). In this case, if the target storage layer is the storage layer where any guide area in the guide unit 1 is located, the motion trajectory formed by the optical signal focused by the optical head moving from the guide area to the data area on the target storage layer is: Figure 6 If the target storage layer is the storage layer where any guide area in the guide unit 2 is located, the motion track formed by the light signal focused by the optical head moving from the guide area to the data area on the target storage layer is Figure 6 If the target storage layer is the storage layer where any guide area in the guide unit 3 is located, the motion track formed by the light signal focused by the optical head moving from the guide area to the data area on the target storage layer is Figure 6 Trajectory 3 shown in (c) in FIG.

[0120] Figure 6 (d) in FIG. 1 shows an exploded top view of each guide unit in the first group of guide units. The shapes of guide unit 1, guide unit 2, and guide unit 3 are as follows: Figure 6 As shown in (d) in .

[0121] It is understandable that Figure 6 The width of any guide area in any guide unit shown in the figure is the same as the width of a data track on the optical disc. That is, the width of a guide unit is the same as the width of a data track on the optical disc. Therefore, for the spiral data track on the optical disc, when the optical head is located above the data track where guide unit 1 is located, during the first rotation of the optical storage medium, the optical signal can only act on the data track where guide unit 1 is located. During the second rotation of the optical storage medium, the optical signal can act on the data track where guide unit 2 is located. During the third rotation of the optical storage medium, the optical signal can act on the data track where guide unit 3 is located.

[0122] In order to ensure that the optical signal can move smoothly from the guide area to the data area, the data reading and writing system (such as Figure 1 The data reading and writing system shown in the figure determines the FE value in real time based on the light signal reflected from the guide area after the light signal acts on the guide area, thereby realizing focus servo of the light signal during movement. In this way, it can be ensured that the light signal will not jump layers during the movement from the guide area to the data area.

[0123] Furthermore, for any guide unit, the adjacent area to that guide unit in the plane of the optical disc is typically a transparent medium. Therefore, as the optical signal moves from any guide area within that guide unit to the data area, it must follow the trajectory of the optical signal within that guide unit. This is because if the optical signal deviates from its trajectory due to environmental factors (e.g., mechanical vibration), the optical signal may impinge on the transparent medium. Consequently, the data read / write system may be unable to implement focus servo on the optical signal.

[0124] To achieve the above objectives, the motion track of the optical signal in each guide unit of the optical disc corresponds to at least one wobble structure identical to the extended track of the motion track. That is, multiple guide areas in a guide unit correspond to wobble structures having the same extended track.

[0125] In this way, when the optical signal moves from the guide area to the data area, the data reading and writing system can serve the optical signal within the plane of the optical disc 60, thereby ensuring that the optical signal can move from the guide area to the data area along the motion trajectory.

[0126] In one possible implementation, an optical disc includes a wobble structure layer, which is shared by multiple storage layers of the disc to implement servoing of optical signals within the disc plane. In this case, the wobble structure layer includes a wobble structure corresponding to each guide unit. Furthermore, the wobble structures having the same extended track corresponding to the multiple guide areas in any guide unit include at least one wobble structure in the wobble structure layer.

[0127] In another possible implementation, each of the multiple storage layers of the optical disc is provided with a wobble structure for servoing the optical signal within the disc plane. That is, each guide area within any guide unit is provided with a wobble structure whose extended trajectory is identical to the motion trajectory corresponding to that guide unit.

[0128] In some embodiments, combined Figure 6 , Figure 6 The multiple groups of guide units described in the figure may also be distributed at the inner edge of the optical disc 60 , or at any position in the middle of the optical disc 60 , which is not limited in this embodiment of the present application.

[0129] As an example, refer to Figure 7 , Figure 7 (a) in the figure shows a schematic diagram of the above-mentioned multiple groups of guide units distributed at the inner edge of the optical disc 60. Figure 7(b) in FIG. 5 is a schematic diagram showing that the aforementioned multiple groups of guide units are distributed in the middle position of the optical disc 60 .

[0130] In practical applications, due to disc manufacturing process errors, the storage layers within a disc cannot be absolutely parallel. Therefore, in some embodiments, multiple sets of guide cells can be positioned at at least two locations: the outer edge, the inner edge, or the center of the disc. In this way, the S-reference curves obtained based on the multiple sets of guide cells at each location can accurately locate the storage layer at that location. Furthermore, the S-reference curves corresponding to the multiple sets of guide cells at each location can also serve as effective reference curves when reading / writing data areas near each location, thereby ensuring accurate layer tracking when reading / writing data areas near that location.

[0131] As an example, refer to Figure 8 , Figure 8 FIG. 5 shows a schematic diagram of the plurality of guide units described above being distributed at the inner edge and middle positions of the optical disc 60. Figure 8 As shown, the data area of optical disc 60 includes data area 1 and data area 2. When reading or writing optical disc 60 from the outer edge to the inner edge, the S-reference curves corresponding to the multiple groups of guide units located at the outer edge of optical disc 60 can be used as effective positioning reference curves when reading or writing data area 1; and the S-reference curves corresponding to the multiple groups of guide units located in the middle of optical disc 60 can be used as effective positioning reference curves when reading or writing data area 2.

[0132] The above is a detailed description of the optical storage medium provided in the embodiment of the present application. The following describes the method for forming a layer of the optical storage medium provided in the embodiment of the present application in conjunction with the accompanying drawings.

[0133] refer to Figure 9 , Figure 9 The following is a flow chart of a method for layering an optical storage medium provided by an embodiment of the present application. The optical storage medium is an optical storage medium provided with a guide area provided by an embodiment of the present application. For example, the optical storage medium is Figure 6 The method can be performed by Figure 1 The data reading and writing system shown is executed. The method may include:

[0134] S101: Obtain a first S-reference curve.

[0135] Optionally, the data reading and writing system can first focus the optical signal on any storage layer of the optical disc, then maintain the position of the optical head in the first direction unchanged, and control the optical head to move above the guide area provided in the optical disc. Then, the data reading and writing system can control the optical head to swing in the first direction, thereby realizing layer-by-layer scanning of the guide area on each storage layer, and then, based on the optical signal reflected by the guide area on each storage layer, the data reading and writing system can obtain the first S reference curve. Here, it can be understood that the specific process of obtaining the first S reference curve based on the optical signal reflected by the guide area can be referred to. Figure 2 and Figure 3 The description of obtaining the S-curve shown is not repeated here.

[0136] The maximum swing distance of the optical head in the first direction is greater than the distance between the first storage layer and the bottom storage layer in the optical disc.

[0137] The embodiment of the present application does not specifically limit the specific method by which the data reading and writing system determines that the optical head has moved to the position above the guide area of the optical disc.

[0138] For example, a data track having a preset reflectivity may be provided at a position radially adjacent to a location where a guide area is provided on any of the aforementioned storage layers on the optical disc. When the data read / write system controls the movement of the optical head, if the intensity of the light signal reflected by any of the storage layers detected by the light detector within a preset time range is a preset constant value, the data read / write system may determine that the optical head has moved over the data track having the preset reflectivity. The magnitude of the constant value corresponds to the aforementioned preset reflectivity.

[0139] In this way, the data reading and writing system can determine that the next data track to be scanned has a guide area, that is, the optical head will move to the top of the guide area.

[0140] As another example, during the manufacture of the optical disc, the reflectivity of the guide area is prepared to be different from the reflectivity of the data area, and different from the reflectivity of any data point after any data is written into the data area. In this way, when the optical head of the data read / write system is moved, when the light detector first detects an optical signal with a preset intensity, it is determined that the optical head has moved over the guide area. The preset intensity corresponds to the reflectivity of the guide area.

[0141] S102. When it is determined that a layer tracking error occurs when reading / writing data in the data area of the first storage layer among the multiple storage layers in the optical disc, the position of the optical head in the first direction is controlled and adjusted according to the above-mentioned first S reference curve to achieve correct layer tracking of the first storage layer.

[0142] It is understood that after acquiring the first S-reference curve, the data read / write system can control and adjust the movement of the optical head to a first position based on the first storage layer indicated in the read / write instruction, so that the optical signal focused by the optical head can be correctly focused on the guide area of the first storage layer. The data read / write system pre-stores / records the first position of the optical head in the first direction when the zero-crossing point corresponding to the first storage layer in the first S-reference curve is acquired. When the optical head is at the first position, the optical signal focused by the optical head can be correctly focused on the guide area of the first storage layer.

[0143] Then, once the optical signal focused by the optical head is correctly focused on the guide area of the first storage layer, the data read / write system controls the optical head to move radially along the optical disc, thereby moving the optical signal focused by the optical head along the motion trajectory within the guide area to the data area of the first storage layer. The data read / write system can then read / write the data area of the first storage layer. The relevant description of the motion trajectory can be found above and is not repeated here.

[0144] During the process of reading / writing the data area of the first storage layer by the data read / write system, the data read / write system tracks and determines in real time whether a layer error has occurred in the first storage layer. The embodiment of the present application does not limit the specific manner in which the data read / write system tracks and determines in real time whether a layer error has occurred in the first storage layer during the process of reading / writing the data area of the first storage layer.

[0145] As an example, the data read / write system can determine whether a layer tracking error has occurred in the first storage layer based on the FE value determined by the reflected light signal of the first storage layer. When the data read / write system determines that the absolute value of the FE value determined at the first moment is greater than a threshold, it can be determined that a layer jump occurred when the data read / write system reads / writes the data area of the first storage layer at the first moment, i.e., a layer tracking error has occurred in the first storage layer. The specific value of this threshold is not specifically limited in this embodiment of the present application.

[0146] In a possible implementation, after the data reading and writing system determines that the first storage layer is incorrectly followed, the data reading and writing system can directly readjust the position of the optical head to the first position, thereby achieving correct following of the first storage layer.

[0147] That is to say, in this real-time mode, when the data reading and writing system determines that a layer tracking error has occurred, it directly adjusts the position of the optical head according to the first position of the optical head in the first direction when the zero crossing point corresponding to the first storage layer in the pre-stored / recorded first S reference curve is obtained, thereby achieving correct layer tracking of the first storage layer.

[0148] It should be understood that in this case, the positions of the multiple groups of guide units used to obtain the first S reference curve in the optical disc are the positions where the optical signal passes and are closest to the current read / write position during the reading / writing process of the data area of the first storage layer.

[0149] In another possible implementation, after the data read / write system determines that a tracking error has occurred in the first storage layer, the system can maintain the optical head stationary in a plane perpendicular to the first direction and control the optical head to swing in the first direction, thereby scanning the data area on each storage layer of the optical disc layer by layer. Furthermore, based on the reflected light signal from the data area on each storage layer, the data read / write system can obtain a first S-curve. The swing distance of the optical head in the first direction is greater than the distance between the first storage layer and the bottommost storage layer of the optical disc.

[0150] It should be understood that the first S-curve is similar to Figure 3 The S-curve 30 is shown in FIG.

[0151] In this way, the data reading and writing system can adjust the position of the optical head in the first direction according to the first S reference curve and the first S curve to achieve correct tracking of the first storage layer.

[0152] Specifically, the data reading and writing system can first determine the phase difference between the first S reference curve and the first S curve for indicating the zero-crossing point of the same storage layer based on the first S reference curve and the first S curve. It can be understood that the phase of the zero-crossing point in the first S reference curve can be represented by the phase difference based on reference point 1. The phase of the zero-crossing point in the first S curve can be represented by the phase difference based on reference point 2. The storage layer corresponding to reference point 1 and the storage layer corresponding to reference point 2 are the same storage layer. A detailed description of the reference points can be found above and will not be repeated here.

[0153] Then, when the difference is less than the preset threshold, the data reading and writing system controls and adjusts the optical head to the second position in the first direction according to the second position of the optical head when obtaining the first S curve and obtaining the zero crossing point corresponding to the first storage layer in the first S curve, thereby achieving correct tracking of the first storage layer.

[0154] It should be understood that when the difference is less than the preset threshold, it indicates that the error between the first S-curve and the first S-reference curve is within an acceptable range, that is, the first S-curve can be used to correctly track the first storage layer.

[0155] When the difference is greater than a preset threshold, the reading / writing of the first storage layer is terminated. In this case, it means that the error between the first S-curve and the first S-reference curve has exceeded the acceptable range, and therefore, the first S-curve can no longer be used to locate the first storage layer.

[0156] In actual applications, when the data read / write system first determines that the phase difference between the first S-reference curve and the zero-crossing point in the first S-curve indicating the same storage layer is greater than a preset threshold, the system does not directly terminate reading or writing to the first storage layer. Instead, the system repeatedly executes the method described in this possible implementation to correctly track the first storage layer. If the data read / write system still cannot correctly track the first storage layer after executing the method described in this possible implementation a preset number of times, the system terminates reading or writing to the first storage layer.

[0157] In some embodiments, if the optical disc is Figure 8 For example, the optical disc shown in FIG. 1 is shown, and the data read / write system reads / writes from the outer side of the optical disc to the inner side of the optical disc. In this case, when the data read / write system begins to read / write the optical disc, it can first continuously scan the guide area located at the outer edge of the optical disc layer by layer to obtain a first S-reference curve.

[0158] Then, after the data reading and writing system locates the first storage layer based on the first S reference curve, it starts to read / write the data area 1 on the first storage layer, and in the process of reading / writing the data area 1, the first storage layer is followed based on the first S reference curve.

[0159] As the data read / write system reads and writes data area 1 in the first storage layer, the optical head gradually moves to above the guide area located in the middle. When the data read / write system determines that the optical signal has entered the guide area (for details, please refer to the description in S101), it can obtain a second S-reference curve corresponding to the guide area located in the middle. Then, after the data read / write system locates the first storage layer based on the second S-reference curve, it begins reading / writing data area 2 on the first storage layer. During the reading / writing process of data area 2, the first storage layer is tracked based on the second S-reference curve.

[0160] Through the above method, the embodiment of the present application can accurately locate the storage layer of the optical disc based on the S reference curve corresponding to the guide area. Furthermore, the S reference curve can also serve as an effective reference curve when tracking the storage layer, thereby avoiding the problem of tracking errors caused by signal attenuation.

[0161] In summary, the embodiments of the present application provide an optical storage medium and a method for tracking the optical storage medium. Particularly, each storage layer of the optical storage medium includes a guide area. Since the number of guide area layers in the guide unit formed by the guide areas on different storage layers in the first direction is limited, and the upper and lower parts of the guide unit are transparent media. Therefore, the FE signal amplitude for drawing the S curve obtained after the optical signal scans the guide area in the first direction is relatively strong, and thus the S curve drawn based on the FE value with the stronger signal amplitude can be used to accurately locate the storage layer. In particular, for the storage layer close to the bottommost storage layer in the optical storage medium, the optical storage medium provided by the embodiments of the present application can be accurately positioned by the S curve obtained after scanning the guide area.

[0162] Furthermore, during the reading / writing process of the optical storage medium, the S-curve obtained by scanning the guide area can also be used as an effective reference curve to track the target storage layer, thereby effectively avoiding the tracking error problem caused by optical signal attenuation.

[0163] The above is an introduction to the optical storage medium layer method provided by the embodiment of the present application from the perspective of method. In order to realize the above functions, it includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0164] In the embodiments of the present application, the functional modules of the optical storage medium layer device can be divided according to the above-mentioned method examples. For example, each functional module can be divided according to each function, or two or more functions can be integrated into a single processing module. The above-mentioned integrated modules can be implemented in the form of hardware or software functional modules. It should be noted that the division of modules in the embodiments of the present application is illustrative and is only a logical functional division. In actual implementation, other division methods may be used.

[0165] like Figure 10 As shown, Figure 10 The structure diagram of a tracking layer device 100 for an optical storage medium provided by an embodiment of the present application is shown. The tracking layer device 100 can be used to perform the above-mentioned tracking layer method for an optical storage medium, for example, to perform Figure 9 The tracking device 100 may include an acquisition unit 101 and a control unit 102.

[0166] An acquisition unit 101 is configured to acquire a first S-reference curve. A control unit 102 is configured to, upon determining that a layer tracking error occurs when reading or writing data from a data area for storing data in a first storage layer among multiple storage layers, control and adjust the position of an optical head in a first direction according to the first S-reference curve to achieve correct layer tracking of the first storage layer. The first S-reference curve is determined based on multiple focus error (FE) signals obtained after an optical signal continuously scans guide areas on multiple storage layers in an optical storage medium in a first direction, wherein the first direction is perpendicular to the multiple storage layers, and the guide areas on the multiple storage layers include the guide area of the first storage layer.

[0167] As an example, combined with Figure 9 , the acquisition unit 101 can be used to execute S101, and the control unit 102 can be used to execute S102.

[0168] Optionally, the acquisition unit 101 is further configured to acquire a first S-curve when determining that a layer tracking error occurs when reading or writing data from a data area for storing data in a first storage layer among the multiple storage layers. The control unit 102 is specifically configured to control and adjust the position of the optical head in the first direction based on the first S-reference curve and the first S-curve to achieve correct layer tracking of the first storage layer. The first S-curve is determined based on multiple FE signals obtained after the optical signal continuously scans the data areas on the multiple storage layers in the first direction.

[0169] As an example, combined with Figure 9 , the control unit 102 can be used to execute S102.

[0170] Optionally, the tracking device 100 further includes a determination unit 103 for determining a phase difference between the first S-curve and the first S-reference curve, indicating zero-crossing points of the same storage layer. A control unit 102 is specifically configured to, if the phase difference is less than a preset threshold, adjust the position of the optical head in the first direction according to the first S-curve to achieve accurate tracking of the first storage layer. The control unit 102 is further configured to, if the phase difference is greater than a preset threshold, terminate reading or writing to the first storage layer.

[0171] As an example, combined with Figure 9 , the control unit 102 can be used to execute S102.

[0172] For the detailed description of the above optional methods, please refer to the above method embodiments, which will not be repeated here. In addition, the explanation and description of the beneficial effects of any of the above-provided heel layer devices 100 can refer to the above corresponding method embodiments, which will not be repeated here.

[0173] As an example, combined with Figure 1 , the following layer device 100 may be Figure 1 The servo controller shown in FIG. 1 is not limited thereto.

[0174] Figure 11 A schematic structural diagram of a signal-carrying medium for carrying a computer program product provided in an embodiment of the present application is shown. The signal-carrying medium is used to store a computer program product or to store a computer program for executing a computer process on a computing device.

[0175] like Figure 11 As shown, the signal bearing medium 110 may include one or more program instructions, which when executed by one or more processors may provide the above-mentioned Figure 9 Thus, for example, reference to Figure 9 One or more features of S101 to S102 may be performed by one or more instructions associated with the signal bearing medium 110. Figure 11 The program instructions in also describe example instructions.

[0176] In some examples, signal-bearing medium 110 may include computer-readable medium 111, such as, but not limited to, a hard drive, a compact disk (CD), a digital video disk (DVD), a digital tape, a memory, a read-only memory (ROM), or a random access memory (RAM), and the like.

[0177] In some implementations, signal bearing medium 110 may include computer recordable medium 112 such as, but not limited to, memory, read / write (R / W) CD, R / W DVD, or the like.

[0178] In some implementations, signal bearing medium 110 may include communication medium 113 such as, but not limited to, digital and / or analog communication media (eg, fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0179] Signal bearing medium 110 may be communicated by a wireless form of communication medium 113 (eg, a wireless communication medium conforming to the IEEE 1902.11 standard or other transmission protocols). The one or more program instructions may be, for example, computer executable instructions or logic implemented instructions.

[0180] In some examples, such as for Figure 9 The described optical storage medium backing device may be configured to provide various operations, functions, or actions in response to one or more program instructions via computer-readable medium 111 , computer-recordable medium 112 , and / or communication medium 113 .

[0181] Should be understood that the arrangement described here is only for the purpose of example. Thus, those skilled in the art will understand that other arrangements and other elements (such as, machines, interfaces, functions, sequences, and functional groups, etc.) can be used instead, and some elements can be omitted altogether according to the desired result. In addition, many of the described elements can be implemented as discrete or distributed components or in any appropriate combination and position in conjunction with the functional entities implemented by other components.

[0182] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer executes the instructions on the computer and when the computer executes the instructions, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server or data center to another website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more media that can be integrated. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0183] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An optical storage medium, characterized in that The optical storage medium includes a plurality of storage layers, each of the plurality of storage layers including: Data area, used to store data; A plurality of guide areas for locating the storage layer; The guide areas of the multiple storage layers form at least two non-overlapping guide units in a first direction, each guide unit includes partial guide areas of at least two storage layers, and the first direction is a direction perpendicular to the multiple storage layers; the area of the multiple storage layers that overlaps with any guide unit in the first direction is a transparent medium, and the transparent medium is used to transmit light signals but not reflect light signals.

2. The optical storage medium according to claim 1, wherein The guide areas belonging to the same guide unit are arranged to overlap in the first direction.

3. The optical storage medium according to claim 1 or 2, characterized in that The at least two guiding units are arranged in a stepped manner in the first direction.

4. The optical storage medium according to claim 1, wherein The at least two guide units include a first guide unit and a second guide unit adjacent to the first guide unit, wherein a first guide area in the first guide unit and a second guide area in the second guide unit are located in a same storage layer.

5. The optical storage medium according to claim 4, wherein The first boot area is the bottom boot area of the first boot unit, and the second boot area is the top boot area of the second boot unit.

6. The optical storage medium according to claim 1, wherein The plurality of storage layers include a plurality of groups of guide units distributed on a moving track of the optical storage medium; wherein a group of guide units in the plurality of groups of guide units includes the at least two guide units.

7. The optical storage medium according to claim 6, wherein: The multiple groups of guide units are located at edge positions and / or middle positions of the optical storage medium.

8. The optical storage medium according to claim 1, wherein All guide areas belonging to one guide unit correspond to wobbled signal grooves having the same extension track.

9. The optical storage medium according to claim 8, wherein The optical storage medium includes a wobble signal groove structure layer, wherein the wobble signal groove structure layer is provided with a wobble signal groove corresponding to each guide unit; or All the guide areas belonging to one guide unit are provided with a wobble signal groove corresponding to the one guide unit.

10. A method for coating an optical storage medium, characterized in that: The method comprises: Obtaining a first S-reference curve, the first S-reference curve being determined based on a plurality of focus error (FE) signals obtained after continuously scanning guide areas on a plurality of storage layers in an optical storage medium with an optical signal in a first direction, wherein the first direction is a direction perpendicular to the plurality of storage layers, wherein the guide areas on the plurality of storage layers include a guide area of the first storage layer; the guide areas of the plurality of storage layers form at least two non-overlapping guide units in the first direction, each guide unit including partial guide areas of at least two storage layers; and a region of the plurality of storage layers that overlaps with any guide unit in the first direction is a transparent medium, wherein the transparent medium is configured to transmit the optical signal and not reflect the optical signal; When it is determined that a layer tracking error occurs when reading / writing data in the data area of the first storage layer among the multiple storage layers, the position of the optical head in the first direction is adjusted according to the first S reference curve to achieve correct layer tracking of the first storage layer; wherein the data area is used to store data.

11. The method according to claim 10, characterized in that When it is determined that a layer tracking error occurs when reading / writing data in a data area of a first storage layer among the multiple storage layers, adjusting the position of the optical head in the first direction according to the first S-reference curve to achieve correct layer tracking of the first storage layer includes: When it is determined that a following layer error occurs when reading / writing data from / to a data area of a first storage layer among the multiple storage layers, obtaining a first S-curve, the first S-curve being determined based on a plurality of FE signals obtained after the optical signal continuously scans the data area on the multiple storage layers in the first direction; According to the first S-reference curve and the first S-curve, the position of the optical head in the first direction is adjusted to achieve correct tracking of the first storage layer.

12. The method according to claim 11, characterized in that The adjusting the position of the optical head in the first direction according to the first S-reference curve and the first S-curve to achieve correct tracking of the first storage layer includes: determining a phase difference between the first S-curve and the first S-reference curve indicating a zero-crossing point of the same storage layer; If the difference is less than a preset threshold, adjusting the position of the optical head in the first direction according to the first S-curve to achieve correct tracking of the first storage layer; If the difference is greater than a preset threshold, the reading / writing of the first storage layer is terminated.

13. A heel layer device for an optical storage medium, characterized in that: include: an acquisition unit, configured to acquire a first S-reference curve, the first S-reference curve being determined based on a plurality of focus error (FE) signals obtained after continuously scanning guide areas on a plurality of storage layers in an optical storage medium with an optical signal in a first direction, wherein the first direction is a direction perpendicular to the plurality of storage layers, wherein the guide areas on the plurality of storage layers include a guide area of the first storage layer; the guide areas of the plurality of storage layers form at least two non-overlapping guide units in the first direction, each guide unit including partial guide areas of at least two storage layers; and a region of the plurality of storage layers overlapping with any guide unit in the first direction is a transparent medium, wherein the transparent medium is configured to transmit the optical signal and not reflect the optical signal; A control unit is configured to control, when determining that a layer following error occurs when reading / writing data in a data area of a first storage layer among the multiple storage layers, adjusting the position of the optical head in the first direction according to the first S reference curve to achieve correct layer following of the first storage layer; wherein the data area is used to store data.

14. The device according to claim 13, characterized in that The acquisition unit is further configured to, when determining that a layer following error occurs when reading or writing data from a data area of a first storage layer among the multiple storage layers, acquire a first S-curve, the first S-curve being determined based on a plurality of FE signals obtained after the optical signal continuously scans the data areas on the multiple storage layers in the first direction; The control unit is specifically configured to control and adjust the position of the optical head in the first direction according to the first S reference curve and the first S curve, so as to achieve correct tracking of the first storage layer.

15. The device according to claim 14, characterized in that The device further comprises: a determining unit, configured to determine a phase difference between the first S-curve and the first S-reference curve indicating a zero-crossing point of the same storage layer; The control unit is specifically used to control the adjustment of the position of the optical head in the first direction according to the first S-curve if the difference is less than a preset threshold value so as to achieve correct tracking of the first storage layer; and to control the end of reading / writing of the first storage layer if the difference is greater than a preset threshold value.

16. A heel layer device for an optical storage medium, characterized in that: include: A transmission interface and one or more processors, wherein the one or more processors receive or send data through the transmission interface, and the one or more processors are configured to call program instructions stored in a memory to execute the method according to any one of claims 10 to 12.

17. A computer-readable storage medium, characterized in that The computer-readable storage medium includes program instructions. When the program instructions are executed on a computer or a processor, the computer or the processor is caused to perform the method according to any one of claims 10 to 12.

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