Optical disc, optical drive and optical drive control method

Abstract

The embodiment of the invention discloses an optical disk, an optical drive and an optical drive control method. A guide layer in the optical disc is provided with a spiral groove, a first groove brim of the groove is provided with a waveform, the waveform is used for carrying guide information, and a second groove brim of the groove is not provided with a waveform. According to the invention, the groove brim at one side of the groove has a waveform, and the groove brim at the other side has no waveform, so that when the position of the optical head corresponds to the groove, the waveform-free groove brim does not interfere with information reading, and guiding information can be read. Besides, for a bank structure formed between two adjacent circles of grooves, the groove brim on one side of the bank structure has a waveform, and the groove brim on the other side of the bank structure has no waveform, so that when the position of the optical head corresponds to the bank structure, the waveform-free groove brim does not interfere with information reading, and the guide information can be read. Therefore, read-write operation can be performed in the recording layer, at the position corresponding to the groove and at the position corresponding to the bank structure, and thus the storage density of the optical disc can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of data storage, and in particular to an optical disc, an optical drive and an optical drive control method. Background Art

[0002] A read-write optical disc generally includes a guide layer and a recording layer. The guide layer is usually a thin plate with pre-pressed grooves. The grooves are spiral-shaped in macroscopic view, with equal width at each position, and have waveforms in microscopic view, which are used to carry guide information. The guide information is mainly used for position indication. During the reading and writing process, the optical drive can determine the position of the optical head through the guide information read by the optical head, and then perform corresponding read and write operations on the position.

[0003] Under this structure, for two adjacent groove circles, there will be mutual interference in waveform between the outer groove edge of the inner groove and the inner groove edge of the outer groove. The optical head can only read the guide information at the position facing the groove. Therefore, the optical head can only read and write the recording layer at the position facing the groove. This limits the storage density of the optical disc. Summary of the invention

[0004] The embodiments of the present disclosure provide an optical disc, an optical drive, and an optical drive control method, which can solve the problems in the related art. The technical solution is as follows:

[0005] In a first aspect, an optical disc is provided, which includes a guide layer and a recording layer. The guide layer and the recording layer are connected, the guide layer has a spiral groove, the first groove edge of the groove has a waveform, the waveform is used to carry guide information, and the second groove edge of the groove does not have a waveform. The recording layer is used to store data.

[0006] In the scheme disclosed in the present invention, a spiral groove is provided in the guide layer of the optical disc, the first bank of the groove has a waveform for carrying guide information, the second bank does not have a waveform, and a bank structure is formed between two adjacent circles of grooves. In this way, the bank on one side of the groove has a waveform, and the bank on the other side has no waveform. When the position of the optical head corresponds to the groove, the bank without a waveform will not interfere with the information reading, and the guide information can be read. In addition, for the bank structure formed between two adjacent circles of grooves, the bank on one side of the bank has a waveform, and the bank on the other side has no waveform. When the position of the optical head corresponds to the bank structure, the bank without a waveform will not interfere with the information reading, and the guide information can be read. It can be seen that in the recording layer, both the position corresponding to the groove and the position corresponding to the bank structure can perform read and write operations, thereby improving the storage density of the optical disc.

[0007] In an optional manner, the second groove eaves is a spiral line. The spiral center of the spiral line can be arranged concentrically with the circle of the optical disc guide layer. The second groove eaves can be a standard spiral line, that is, the increment of the radius of the spiral line is positively correlated with the increment of the central angle of the spiral line. In this way, the processing difficulty of the second groove eaves can be reduced.

[0008] In an optional manner, the center line of the waveform is a spiral line. The center line of the waveform is a line connecting the symmetry centers of each single-cycle wave constituting the waveform. In this way, the processing difficulty of the first groove eaves can be reduced.

[0009] The first groove eaves has a waveform, which is composed of a plurality of standard single-cycle waves and a plurality of high-frequency single-cycle waves, wherein the single-cycle wave can be a cosine wave or a sawtooth wave. The frequency of the high-frequency single-cycle wave is greater than the frequency of the standard single-cycle wave, for example, the frequency of the high-frequency single-cycle wave can be twice the frequency of the standard single-cycle wave. In this way, the accuracy of the demodulation guidance information can be improved.

[0010] In an optional manner, the waveform is a cosine wave.

[0011] In an optional manner, the center line of the waveform is equidistant from the second groove eaves on both sides. In this way, the equivalent width of the groove and the equivalent width of the corresponding bank structure can improve the accuracy of the demodulation guidance information.

[0012] In an optional manner, the distance between two points included in any radially adjacent point pair in the second groove rim is equal to a specified value, wherein the radially adjacent point pair is two adjacent intersection points among a plurality of intersection points of the same radius of the optical disc and the second groove rim. In this way, the equivalent width of each circle of grooves is equal to the equivalent width of each circle of bank structures, and when the optical head demodulates the guide information in the groove and then switches to demodulating the guide information on the bank structure, or when the optical head demodulates the guide information in the bank structure and then switches to demodulating the guide information in the groove, there is no need to adjust the size of the irradiation area, which can improve the convenience of demodulating the guide information.

[0013] In an optional manner, the specified value is greater than or equal to twice the read / write unit width corresponding to the optical disc. The read / write unit width is the minimum width of the recording point generated by the phase change of the recording layer caused by focusing the recording beam in the radial direction of the optical disc. In this way, the read / write unit width is exactly equal to the equivalent width of the groove and bank structure. At this time, when reading data, the recording beam can just cover the recording point in the irradiation area of ​​the recording layer, and will not be crosstalked by the recording point on another recording line, which can improve the reading accuracy.

[0014] In an optional manner, the optical disc includes multiple recording layers, the multiple recording layers are located on the same side of the guide layer, and the guide layer and the multiple recording layers are stacked. In this way, during the process of reading and writing data, the multiple recording layers in the optical disc can all use the guide information in the guide layer, and the multiple recording layers can all be used to store data, which can further improve the storage density of the optical disc.

[0015] In a second aspect, an optical drive is provided, which is used to perform a read operation or a write operation on an optical disc, wherein the guide layer of the optical disc has a spiral groove, wherein the first groove eaves of the groove have a waveform carrying guide information, and the second groove eaves of the groove do not have a waveform, and the optical drive includes an optical head and a processor. The optical head includes a light emitting element, a beam splitter, and a plurality of light detectors. The beam splitter is used to split the light beam emitted by the light emitting element into a plurality of light beams, wherein the plurality of light beams correspond to a plurality of irradiation areas on a working surface of the optical drive, and the working surface is a surface in the optical drive corresponding to the guide layer of the optical disc. The plurality of light detectors are used to detect the plurality of irradiation areas. The processor is used to: determine the guide information based on the detection result of the first light detector among the plurality of light detectors, determine the light product corresponding to each other light detector within a specified time length based on the detection results of other light detectors other than the first light detector, determine the radial offset of the optical head based on the light product corresponding to each other light detector, and perform offset correction on the optical head based on the radial offset, wherein the radial offset includes a point away from the center of the working surface or a point close to the center of the working surface.

[0016] In the scheme shown in the present disclosure, the light beam emitted by the light emitting element is divided into multiple light beams by a beam splitter, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. The guide light beam is divided into multiple light beams by a beam splitter, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. After the multiple light beams contact the guide layer of the optical disc, they are reflected, and multiple light detectors receive the multiple reflected light beams correspondingly, so as to detect the multiple irradiation areas. The processor is used to determine the light product corresponding to each other light detector within a specified time period based on the detection results of other light detectors other than the first light detector, determine the radial offset of the optical head based on the light product corresponding to each other light detector, and perform offset correction on the optical head based on the radial offset. Therefore, for the optical disc provided in the embodiment of the present disclosure, the optical drive can be used to align the guide track with the groove or shore structure to accurately demodulate the guide information. In this way, the accuracy of the demodulated guide information can be guaranteed while improving the data storage density of the optical disc.

[0017] In an optional manner, the optical head includes a light emitting element, a beam splitter, a first light detector, a second light detector, and a third light detector. The beam splitter is used to split the light beam emitted by the light emitting element into three light beams, and the three light beams correspond to a first irradiation area, a second irradiation area, and a third irradiation area on the working surface of the optical drive, respectively. The first light detector, the second light detector, and the third light detector are used to detect the first irradiation area, the second irradiation area, and the third irradiation area, respectively. The processor is used to: determine the first light product within a specified time length based on the detection result of the second light detector, determine the second light product within a specified time length based on the detection result of the third light detector, and determine the radial offset of the optical head based on the first light product and the second light product. In this way, the processor can determine the first light product and the second light product based on the second light detector and the third light detector, respectively, and determine the radial offset of the optical head through the first light product and the second light product, which can improve the accuracy of determining the radial offset of the optical head.

[0018] In an optional manner, the first irradiation area, the second irradiation area, and the third irradiation area are all circular, the diameter of the first irradiation area is greater than twice the waveform amplitude of the first groove eaves, the radius of the second irradiation area is less than the distance from the trough of the waveform to the corresponding second groove eaves, the center of the second irradiation area is tangent to the trough, the diameter of the third irradiation area is less than the distance from the peak of the waveform to the corresponding second groove eaves, and the center of the third irradiation area is tangent to the peak. The processor is used to: determine the radial offset of the optical head based on the magnitude relationship between the first light product and the second light product. In this way, when the first light product is greater than the second light product, it can be determined that the guide track is radially deviated inward, that is, the optical head is radially deviated inward, and the processor can send an outward movement signal to the optical head to make the optical head move radially outward. When the first light product is less than the second light product, it can be determined that the guide track is radially deviated outward, that is, the optical head is radially deviated outward, and the processor can send an inward movement signal to the optical head to make the optical head move radially inward, ensuring that the guide track is aligned with the groove to accurately demodulate the guide information.

[0019] In a third aspect, a method for controlling an optical drive is provided, the method comprising: receiving an operation instruction, the operation instruction being a read instruction or a write instruction, the operation instruction carrying a first guide track number and a first address number, the operation instruction being used to instruct the optical drive to perform a read operation or a write operation on the optical disc, the guide layer of the optical disc having a spiral groove, the first groove eave of the groove having a waveform carrying guide information, and the second groove eave of the groove having no waveform. Controlling the optical head to move to a position corresponding to the first guide track number and the first address number. Performing a read operation or a write operation based on the operation instruction. In this way, the operation instruction carries not only the first address number but also the first guide track number. When controlling the optical drive, the position of the optical head is no longer moved only according to the address number, but the position of the optical head is moved according to the guide track number and the address number at the same time. Therefore, for an optical disc whose read and write logic is provided with multiple guide tracks during the read and write process, the read operation and the write operation can still be effectively completed, thereby expanding the scope of application of the optical drive.

[0020] In an optional manner, controlling the optical head to move to a position corresponding to the first guide track number and the first address number includes: controlling the optical head based on the first guide track number so that the optical head is located on the first guide track. Controlling the optical head to move to a position on the first guide track corresponding to the first address number. In this way, when the optical drive controls the movement of the optical head, the optical head is first located on the first guide track, and then the optical head is controlled to move to a position on the first guide track corresponding to the first address number, and the adjustment range is from large to small, which can avoid repeated adjustment of the position of the optical head and improve the efficiency of adjusting the position of the optical head.

[0021] In an optional manner, the optical head is controlled based on the first guide track number so that the optical head is located on the first guide track, including: if the first guide track number is different from the guide track number of the guide track where the optical head is currently located, the optical head is controlled to move a specified distance in the radial direction, wherein the specified distance is an odd multiple of the track pitch. If the first guide track number is the same as the guide track number of the guide track where the optical head is currently located, the position of the optical head is kept unchanged. In this way, whether to control the movement of the optical head is determined based on whether the first guide track number is the same as the guide track number of the guide track where the optical head is currently located, thereby improving the efficiency of adjusting the position of the optical head.

[0022] In an optional manner, controlling the optical head to move to a position on the first guide track corresponding to the first address number includes: determining a second address number corresponding to the current position of the optical head. Determining a difference between the first address number and the second address number. Controlling the movement of the optical head based on the difference, and switching to executing a process of determining the second address number corresponding to the current position of the optical head. In this way, different adjustment methods can be determined to move the optical head according to the difference between the first address number and the second address number, thereby improving the accuracy of adjusting the position of the optical head.

[0023] In an optional manner, performing a read operation or a write operation based on an operation instruction includes: controlling the optical head to move along the first guide track where it is currently located and performing a read operation or a write operation. After the optical head moves to the position corresponding to the first guide track number and the third address number to perform a read operation or a write operation, if the operation instruction has not been completed, the optical head is controlled to move to the position corresponding to the second guide track number and the fourth address number, wherein the second guide track number corresponds to a different guide track than the first guide track number, the third address number is the tail address number, and the fourth address number is the head address number. Controlling the optical head to move along the second guide track where it is currently located and performing a read operation or a write operation. In this way, during the writing process, when the storage area in the recording layer corresponding to the tail storage address of any guide track in the guide layer completes data writing, the optical drive can control the optical head to move directly to the storage area in the recording layer corresponding to the head storage address of another guide track to perform data. During the reading process, when the data reading of the storage area in the recording layer corresponding to the tail storage address of any guide track in the guide layer is completed, the optical drive can control the optical head to move directly to the storage area in the recording layer corresponding to the first storage address of another guide track to read data, thereby improving the reading and writing efficiency of the optical drive. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0025] Figure 2 is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0026] Figure 3 is a schematic diagram of a structure of a light detector receiving a reflected light beam provided by an embodiment of the present disclosure;

[0027] Figure 4 It is a schematic diagram of a structure in which a light beam emitted by an optical head irradiates an optical disc provided by an embodiment of the present disclosure;

[0028] Figure 5 is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0029] Figure 6 is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0030] Figure 7 is a schematic diagram of an output waveform of a light detector of an optical disc at different rotation speeds provided by an embodiment of the present disclosure;

[0031] Figure 8 is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0032] Fig. 9is a schematic structural diagram of a guide layer of an optical disc provided by an embodiment of the present disclosure;

[0033] Fig.10 It is a schematic structural diagram of a recording layer of an optical disc provided by an embodiment of the present disclosure;

[0034] Fig.11 It is a schematic structural diagram of a recording layer of an optical disc provided by an embodiment of the present disclosure;

[0035] Fig.12 is a schematic diagram of the structure of an optical disc provided by an embodiment of the present disclosure;

[0036] Fig.13 is a structural schematic diagram of an optical drive provided by an embodiment of the present disclosure;

[0037] Fig.14 is a schematic diagram of a guide layer irradiated with multiple light spots provided by an embodiment of the present disclosure;

[0038] Fig.15 It is a schematic diagram of a structure in which a plurality of light detectors receive a plurality of reflected light beams, provided by an embodiment of the present disclosure;

[0039] Fig.16 is a structural schematic diagram of an optical drive provided by an embodiment of the present disclosure;

[0040] Fig.17 is a schematic diagram of a guide layer irradiated with multiple light spots provided by an embodiment of the present disclosure;

[0041] Fig.18 is a flow chart of a method for controlling an optical drive provided by an embodiment of the present disclosure;

[0042] Fig.19 is a schematic diagram of the position of a guide track in an optical drive provided by an embodiment of the present disclosure;

[0043] Fig. 20 It is a schematic diagram of a guide layer irradiated with multiple light spots provided by an embodiment of the present disclosure.

[0044] Legend

[0045] 01. Swinging groove; 02. Swinging bank structure;

[0046] 1. Guide layer;

[0047] 11. Groove; 12. Bank structure;

[0048] 111. first trough eaves; 112. second trough eaves; 113. center line of the waveform;

[0049] 1121, radially adjacent point pairs;

[0050] 2. Recording layer;

[0051] 21. First recording line; 22. Second recording line;

[0052] 3. Base;

[0053] 4. Protective layer;

[0054] 100. Bald head;

[0055] 101. light emitting element; 102. optical splitter; 103. optical detector;

[0056] 1031, a first light detector; 1032, a second light detector; 1033, a third light detector;

[0057] 1031a, first detection area; 1032a, second detection area; 1033a, third detection area;

[0058] 1032b, the point in the second detection area that is the shortest distance from the center point of the working surface;

[0059] 1033b, the point in the third detection area that is the farthest from the center point of the working surface;

[0060] 200, processor;

[0061] 300. Motor. DETAILED DESCRIPTION

[0062] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0063] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent disclosure specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0064] Nowadays, read-write optical disc media has become one of the most common data storage media. Read-write optical discs include recordable optical discs and rewritable optical discs. Recordable optical discs and rewritable optical discs include overlapping guide layers and recording layers. The guide layer is used to carry guide information, and the recording layer is used to store data.

[0065] like Figure 1 ( Figure 1 As shown in FIG. 1 , which is a top view of a guide layer of an optical disc in the related art, the guide layer has a spiral wobble groove 01 , and a wobble land structure 02 is formed between two adjacent circles of the wobble groove 01 .

[0066] refer to Figure 2 ( Figure 2 for Figure 1 (Partially enlarged view), the swing groove 01 has a uniform width in its extending direction.

[0067] The swing frequency of the swing groove 01 is modulated with guide information. The swing frequency of the swing groove 01 is a quasi-cosine wave, wherein the quasi-cosine wave means that the swing groove 01 is a waveform composed of several single-cycle cosine waves, and each single-cycle cosine wave has a symmetry center, and these symmetry centers are distributed in a spiral shape around the center point of the guide layer.

[0068] The wobbling groove 01 includes two single-cycle cosine waves, one of which is a standard cosine wave and the other is a high-frequency cosine wave, and the frequency of the high-frequency cosine wave is greater than the frequency of the standard cosine wave. For example, the frequency of the high-frequency cosine wave is twice the frequency of the standard cosine wave, or the frequency of the high-frequency cosine wave is 1.5 times the frequency of the standard cosine wave. The amplitudes of the standard cosine wave and the high-frequency cosine wave are equal and are both about 0.16 microns. The wavelength of the standard cosine wave is about 5 microns, and the distance between the center lines of two adjacent circles of the wobbling groove 01 is about 0.32 microns.

[0069] The guide light beam emitted by the optical head falls on the surface of the guide layer to form an irradiation area, which is circular in shape and has a diameter slightly larger than twice the amplitude of the above cosine wave, that is, the irradiation area can cover at least part of the wobbling groove 01 and the wobbling bank structure 02 corresponding to the part of the wobbling groove 01. The optical detector is located on the reflected light path of the guide light beam and is used to detect the reflected light beam of the irradiation area.

[0070] refer to Figure 3 The optical detector may be a four-quadrant photodetector. During the rotation of the optical disc, due to the different reflectivities of the wobbling groove 01 and the wobbling bank structure 02, the light intensity values ​​detected by the four quadrants of the four-quadrant photodetector show periodic changes in intensity, and then according to the periodic changes in intensity, the guide information carried in the guide layer can be demodulated.

[0071] Combination Figure 2 and Figure 3 When the illumination area corresponds to the first position, the sum of the light intensity L1 in the first quadrant and the light intensity L2 in the second quadrant is greater than the sum of the light intensity L3 in the third quadrant and the light intensity L4 in the fourth quadrant; when the illumination area corresponds to the second position, the sum of the light intensity L1 in the first quadrant and the light intensity L2 in the second quadrant is less than the sum of the light intensity L3 in the third quadrant and the light intensity L4 in the fourth quadrant.

[0072] Furthermore, the guide information includes timing information (Timing) for indicating the rotation speed of the optical drive motor and address information for indicating the data storage location. The guide information may also include the optical disc address number, the manufacturer of the optical disc, the implementation standard, etc.

[0073] The optical head first corresponds to the position of one end of the swing groove 01 close to the center of the optical disc, and the guide information at this end is first demodulated. The optical disc rotates with the motor of the optical drive, and the optical head moves outward in the radial direction, gradually completing the demodulation of all the guide information. In the process of the optical head moving outward in the radial direction, if the motor of the optical drive rotates at a constant speed, then as the radius of the swing groove 01 increases, the linear velocity of the corresponding position of the optical head increases accordingly. If the linear velocity of the corresponding position of the optical head is too large, it may cause the demodulation of the guide information to fail. Therefore, it is necessary to adjust the speed of the motor of the optical drive in the process of the optical head moving outward in the radial direction. The specific method can be that when the four-quadrant photoelectric detector detects that the time interval of the change of the light intensity value is less than the preset time interval, the processor of the optical drive sends a speed reduction signal to the motor. The speed reduction signal is used to instruct the optical drive to reduce the speed of the motor so that the linear velocity of the corresponding position of the optical head tends to be consistent, so as to ensure the smooth demodulation of the guide information.

[0074] refer to Figure 7 For example, if (L1+L2)>(L3+L4) the four-quadrant photodetector outputs a high level, and (L1+L2)<(L3+L4) the four-quadrant photodetector outputs a low level, then when the motor of the optical drive rotates at a constant speed, the output waveforms of the high and low levels should be the waveforms on the left. As the radius of the swing groove 01 increases, the linear velocity of the corresponding position of the optical head increases accordingly, and the duration of the high and low levels becomes shorter and shorter. At this time, when the four-quadrant photodetector detects that the time interval of the change in light intensity value is less than the preset time interval, the processor of the optical drive sends a speed reduction signal to the motor to reduce the speed of the optical drive motor, ensuring that the output waveforms of the high and low levels tend to the waveform on the right (the periods of the high and low levels in the waveform on the right are equal) to ensure the smooth demodulation of the guide information.

[0075] refer to Figure 4When writing data using a recordable optical disc or a rewritable optical disc, the optical head 100 simultaneously emits a guide beam and a recording beam, the guide beam converges on the guide layer 1 of the optical disc, and the recording beam converges on the recording layer 2. The optical detector is located on the reflection light path of the guide beam, and is used to detect the reflected beam of the irradiated area and demodulate the guide information. According to the demodulated guide information, the recording beam completes the burning on the recording layer 2 and stores the data in the corresponding storage area; when reading data, the optical head 100 simultaneously emits a guide beam and a recording beam, the guide beam converges on the guide layer 1 of the optical disc, and the recording beam converges on the recording layer 2. When the user needs to read specific data, the optical drive can address the guide layer 1 through the address number in the demodulated guide layer 1, find the corresponding storage address in the guide layer 1, and then find the storage area corresponding to the storage address, so as to read the specific data required by the user in the corresponding storage area. In the process of writing and reading data, the storage area in the recording layer 2 corresponds one-to-one with the storage address in the guide layer 1. In the process of reading and writing data, only when the optical head can accurately demodulate the guide information can the optical head's reading and writing operations on the recording layer be reliable.

[0076] refer to Figure 1 In the related art, a guide layer in an optical disc has a spiral wobbling groove 01. Figure 2 As shown, a swing bank structure 02 is formed between two adjacent circles of swing grooves 01. The swing bank structure 02 is usually spiral-shaped. However, for two adjacent circles of swing grooves 01, due to the gradual increase in the radius of the swing groove 01, there is a phase difference between the outer groove eaves of the swing groove 01 close to the spiral center and the inner groove eaves of the swing groove 01 far from the spiral center, which makes the width between the two groove eaves constituting the swing bank structure 02 change randomly. Therefore, for the swing bank structure 02, it is impossible to demodulate the guide information by using the above-mentioned method of using a four-quadrant photodetector to detect the periodic intensity change of the light intensity value, which results in the position corresponding to the swing bank structure 02 in the recording layer of the optical disc being unable to perform data storage, and the data storage density is low. In this regard, the embodiment of the present disclosure provides an optical disc that can improve the data storage density of the optical disc.

[0077] The embodiment of the present disclosure provides an optical disc, which includes a guide layer 1 and a recording layer 2, wherein the guide layer 1 and the recording layer 2 are connected. The guide layer 1 has a spiral groove 11, a first groove eave 111 of the groove 11 has a waveform, and the waveform is used to carry guide information, and a second groove eave 112 of the groove 11 does not have a waveform. The recording layer 2 is used to store data.

[0078] In this way, the first groove eaves 111 on one side of the groove 11 have waveforms, and the second groove eaves 112 on the other side have no waveforms. When the position of the optical head corresponds to the groove 11, the second groove eaves 112 without waveforms will not interfere with information reading, and the guide information can be read. In addition, for the bank structure 12 formed between two adjacent circles of grooves 11, the first groove eaves 111 on one side of the bank structure 12 have waveforms, and the second groove eaves 112 on the other side have no waveforms. When the position of the optical head corresponds to the bank structure 12, the second groove eaves 112 without waveforms will not interfere with information reading, and the guide information can be read. It can be seen that in the recording layer 2, the position corresponding to the groove 11 and the position corresponding to the bank structure 12 can perform read and write operations, thereby improving the storage density of the optical disc.

[0079] Figure 5 A schematic diagram of the structure of a guide layer of an optical disc provided in an embodiment of the present disclosure is shown in FIG. Figure 5 As shown, the guide layer 1 has a spiral groove 11. A bank structure 12 is formed between two adjacent circles of the groove 11, and the bank structure 12 also has a spiral structure.

[0080] In implementation, the guide layer 1 and the recording layer 2 are stacked, both of which have a circular thin plate structure, and the radii of the guide layer 1 and the recording layer 2 can be equal, and the guide layer 1 is coaxial with the recording layer 2. For the guide layer 1, a device can be used to firstly process a wobble groove, and both sides of the groove eaves of the wobble groove have waveforms, and the waveforms of the groove eaves on both sides are used to carry guide information, and then, a device can be used to reprocess the groove eaves on one side of the wobble groove so that the groove eaves on this side no longer have waveforms, thereby obtaining a groove 11.

[0081] Optionally, the first groove eave 111 can be a groove eave in the groove 11 close to the center of the optical disc, or a groove eave in the groove 11 far from the center of the optical disc. The embodiment of the present disclosure does not limit the position of the first groove eave 111 in the groove 11.

[0082] In one example, the second gutter 112 is a spiral line.

[0083] like Figure 6 As shown, the second groove eaves 112 are spiral lines, and the spiral center of the second groove eaves 112 is the center of the optical disc.

[0084] In this way, since the second groove ridge 112 has no waveform, the second groove ridge 112 does not carry the guide information. In the recording layer, the position corresponding to the groove 11 can use the guide information carried by the first groove ridge 111 to write data, and the position corresponding to the land structure 12 can also use the guide information carried by the first groove ridge 111 to write data, thereby improving the data storage density of the optical disc. At the same time, the processing difficulty of the second groove ridge 112 can also be reduced.

[0085] In one example, the center line 113 of the wave shape of the first gutter 111 is a spiral line.

[0086] The center line 113 of the waveform of the first gutter eave 111 is a line connecting the symmetry centers of each single-cycle wave constituting the waveform.

[0087] In this way, the difficulty of processing the first gutter 111 can be reduced.

[0088] In practice, the wavelength of each single-cycle wave is about 5 microns, and the amplitude of each single-cycle wave is equal and is about 0.16 microns. The center line 113 is actually a line connecting multiple line segments. Since the distance between each line segment is very small, the center line 113 can be approximately considered as a spiral line.

[0089] In implementation, in the guide layer, every 56 consecutive single-cycle cosine waves constitute an ADIP unit (Address in Pre-groove). The first single-cycle cosine wave in each ADIP unit must be a high-frequency cosine wave. Among these 56 single-cycle cosine waves, according to the preset coding rules, a specific number of single-cycle cosine waves at a specific position are high-frequency cosine waves, and the ADIP units composed of standard cosine waves and high-frequency cosine waves in different arrangement orders are used to represent the numbers "0" and "1", respectively. For example, for any ADIP unit, if its 12th or 14th single-cycle cosine wave is a high-frequency cosine wave, then the ADIP unit represents the number "1", and the remaining ADIP units in the arrangement order all represent the number "0". The above coding rules can be set according to actual needs, and the embodiments of the present disclosure are not limited.

[0090] Further, every 83 consecutive ADIP units constitute one ADIP word.

[0091] There are multiple storage addresses in the boot layer, each storage address corresponds to a storage area in the recording layer, and each storage address has a number, namely, an address number. Multiple ADIP units can form a string of address numbers, and this string of address numbers is used to indicate which storage address in the boot layer the storage address is. It is easy to understand that this string of address numbers can also be used to indicate which storage area in the recording layer corresponding to the storage address is. In each ADIP word, the first few ADIP units (for example, the first 8 ADIP units) are used to indicate the number of the ADIP word, which is the address number. The data storage capacity corresponding to each ADIP word is 64K, that is, the data storage capacity of the storage area corresponding to each storage address is 64K.

[0092] Thus, each ADIP word corresponds to a storage address, and the first several ADIP units in each ADIP word form an address number. The boot layer includes a plurality of continuous storage addresses, and each storage address has its own address number.

[0093] For the guide information, low-pass filtering can be used to separate the indication information for indicating the rotation speed of the optical drive motor and the address information for indicating the data storage location in the guide information, which will not be described in detail here.

[0094] refer to Figure 6 It can be understood that the amplitude of the waveform of the first gutter eaves 111 is very small relative to its wavelength. The amplitude of the waveform of the first gutter eaves 111 in the drawings shown in the present disclosure is larger to facilitate readers to observe the structures of the first gutter eaves 111 and the second gutter eaves 112.

[0095] Exemplarily, the center line 113 is arranged concentrically with the second gutter 112 .

[0096] In this way, the first groove eaves 111 and the second groove eaves 112 can be arranged concentrically, thereby improving the accuracy of demodulating the guidance information.

[0097] In one example, the waveform of the first groove eaves 111 is a cosine wave, and the amplitude of each single-cycle cosine wave is equal.

[0098] Illustratively, the amplitude of a single cycle of the cosine wave is approximately 0.16 microns.

[0099] In implementation, the waveform of the first groove eaves 111 includes two waveforms, one is a standard cosine wave, and the other is a high-frequency cosine wave, and the frequency of the high-frequency cosine wave is twice the frequency of the standard cosine wave.

[0100] In one example, the distances from the center line 113 of the waveform of the first gutter eaves 111 to two adjacent circles of the second gutter eaves 112 are equal.

[0101] like Figure 8 As shown, each circle of the center line 113 has a circle of second groove eaves 112 on both sides, the distance from the center line 113 to the second groove eaves 112 away from the spiral center is D1, and the distance from the center line 113 to the second groove eaves 112 close to the spiral center is D2, D1 = D2.

[0102] In this way, the equivalent width of the groove 11 is equal to the equivalent width of the corresponding bank structure 12, thereby improving the accuracy of the demodulation guidance information.

[0103] In one example, the distance between two points included in any radially adjacent point pair in the second gutter 112 is equal to a specified value.

[0104] like Fig. 9As shown, the radially adjacent point pair is two adjacent intersection points among the multiple intersection points of the same radius of the optical disk and the second groove flange 112. That is, the second groove flange 112 is an equidistant spiral line, and the distance between two adjacent circles of the second groove flange 112 is equal.

[0105] In this way, the equivalent width D1 of each circle of groove 11 is equal to the equivalent width D2 of each circle of bank structure 12. After the optical head demodulates the guidance information in the groove 11, it turns to the bank structure 12 to demodulate the guidance information, or after the optical head demodulates the guidance information in the bank structure 12, it turns to the groove 11 to demodulate the guidance information, there is no need to adjust the size of the irradiation area, which can improve the convenience of demodulating the guidance information.

[0106] Optionally, the distance (ie, the specified value) between two points included in the radially adjacent point pair is greater than or equal to twice the width of the read / write unit corresponding to the optical disc.

[0107] In implementation, reference Figure 4 , the recording light beam output by the optical head is focused on specific positions of the recording layer 2, causing phase changes at these positions. Data writing can be completed by causing phase changes at different positions of the recording layer. Fig.10 As shown, the recording layer 2 has a first recording line 21 and a second recording line 22, both of which have a spiral structure, and the first recording line 21 and the second recording line 22 correspond to the groove 11 and the bank structure 12 in the vertical direction. Each recording line is composed of a plurality of recording points, and the recording points are obtained by focusing the recording light beam to cause a phase change in the recording layer.

[0108] like Fig.11 ( Fig.11 for Fig.10 As shown in the partial enlarged view of FIG. 1 , the wireframe includes part of the first recording line 21 and part of the second recording line 22, and part of the first recording line 21 and part of the second recording line 22 are composed of a plurality of recording points. Limited by the wavelength and numerical aperture of the light, the minimum width of the recording point in the radial direction has a minimum value M1, and the minimum value M1 is the read-write unit width corresponding to the optical disc. Fig.11 , the distance between the two points included in the radially adjacent point pair is the specified value N1. When the read-write unit width M1 and the specified value N1 satisfy N1=2·M1, the read-write unit width M1 is exactly equal to the equivalent width of the groove 11 and the bank structure 12. At this time, when reading data, the irradiation area of ​​the recording light beam in the recording layer 2 can just cover the recording point and will not be affected by the crosstalk of the recording point on another recording line.

[0109] In this way, the storage density of the optical disc is improved to the greatest extent and the reading accuracy can be improved when reading the data stored in the recording layer 2 .

[0110] In one example, if Fig.12As shown, the optical disc includes a plurality of recording layers 2 , and the plurality of recording layers 2 are all located on the same side of the guide layer 1 , and the guide layer 1 and the plurality of recording layers 2 are overlapped.

[0111] In this way, during the process of reading and writing data, the multiple recording layers 2 in the optical disc can all use the guide information in the guide layer 1, and the multiple recording layers 2 can all be used to store data, which can further improve the storage density of the optical disc.

[0112] Optionally, the optical disc may further include a substrate 3 and a protective layer 4 .

[0113] like Fig.12 As shown, the substrate 3 is located on the side of the guide layer 1 away from the recording layer 2, and the protective layer 4 is located on the side of the recording layer 2 farthest from the guide layer 1 away from the guide layer 1. The substrate 3, the guide layer 1, multiple recording layers 2 and the protective layer 4 are stacked.

[0114] In this way, the protective layer 4 and the substrate 3 can correspondingly protect the guide layer 1 and the recording layer 2, prevent the guide layer 1 and the recording layer 2 from being scratched, and increase the service life of the optical disc.

[0115] When using an optical drive to read or write an optical disc, it is necessary to perform servo control on the optical head so that the irradiation area of ​​the optical head in the guide layer 1 is aligned with the wobbling groove 01 to accurately demodulate the guide information.

[0116] In the related art, reference Figure 2 and Figure 3 As shown, a four-quadrant push-pull method is usually used to perform servo control on the optical head.

[0117] Exemplarily, in the related art, the guide light beam is irradiated onto the working surface of the optical drive to form a circular irradiation area. The guide light beam is reflected after contacting the guide layer of the optical disc. A four-quadrant photodetector is used to receive the reflected light beam. Due to the different reflectivities of the swing groove 01 and the swing bank structure 02, the light product of the four quadrants of the four-quadrant photodetector will change within a specified time period. Within the specified time period, the sum of the light product Q1 of the first quadrant + the light product Q2 of the second quadrant is subtracted from the sum of the light product Q3 of the third quadrant + the light product Q4 of the fourth quadrant to obtain the light product difference q. If q is greater than zero, it means that within the specified time period, the sum of the light product Q1 of the first quadrant + the light product Q2 of the second quadrant is greater than the sum of the light product Q3 of the third quadrant + the light product Q4 of the fourth quadrant, and the guide light beam is radially deviated outward. At this time, the processor will send an inward movement signal to the optical head, so that the optical head moves radially inward to ensure that the irradiation area irradiated by the optical head in the guide layer 1 is aligned with the swing groove 01 to accurately demodulate the guide information. Similarly, within a specified time length, the sum of the light product Q1 of the first quadrant + the light product Q2 of the second quadrant is subtracted from the sum of the light product Q3 of the third quadrant + the light product Q4 of the fourth quadrant to obtain the light product difference q. If q is less than zero, it means that within the specified time length, the sum of the light product Q1 of the first quadrant + the light product Q2 of the second quadrant is less than the sum of the light product Q3 of the third quadrant + the light product Q4 of the fourth quadrant, and the guide light beam is radially deflected inward. At this time, the processor will send an outward movement signal to the optical head, so that the optical head moves radially outward to ensure that the irradiation area of ​​the optical head in the guide layer 1 is aligned with the swing groove 01, so as to accurately demodulate the guide information.

[0118] However, for the optical disc provided by the embodiment of the present disclosure, since the first groove eaves 111 have a waveform and the second groove eaves 112 do not have a waveform, when the above-mentioned four-quadrant push-pull method is used to perform servo control on the optical head, if the irradiation area of ​​the optical head in the guide layer 1 is aligned with the groove 11, the difference in light product q is always greater than zero or always less than zero, that is, for the optical disc provided by the embodiment of the present disclosure, the four-quadrant push-pull method is no longer applicable. In this regard, the embodiment of the present disclosure provides an optical drive, which can make the irradiation area of ​​the optical head in the guide layer 1 aligned with the groove 11, so as to accurately demodulate the guide information.

[0119] The embodiment of the present disclosure provides an optical drive, which can be used to perform a read operation or a write operation on the above optical disc, in which the guide layer 1 has a spiral groove 11, the first groove rim 111 of the groove 11 has a waveform carrying guide information, and the second groove rim 112 of the groove 11 does not have a waveform, and the optical drive includes an optical head 100 and a processor 200. When using the optical drive and optical disc provided by the embodiment of the present disclosure, a read-write logic with two guide tracks can be set during the read-write process, wherein the guide track is the movement track of the equivalent center of the light beam emitted by the optical head on the optical disc during the read-write process.

[0120] like Fig.13 As shown, the optical head 100 includes a light emitting element 101, a beam splitter 102 and a plurality of light detectors 103. The light emitting element 101 emits a guided light beam.

[0121] Exemplarily, the light emitting element 101 includes a laser emitter, a collimating prism and an objective lens (all not shown).

[0122] The laser emitter may be a semiconductor laser, a gas laser, a solid laser, a liquid laser, or a fiber laser. The disclosed embodiments do not limit the type of laser emitter, and a semiconductor laser is used as an example in the following content. The collimating prism is used to converge the light beam emitted by the laser emitter into parallel light. The objective lens may be a single-sided convex lens, and its material may be a resin material or a glass material. The disclosed embodiments do not limit the material of the objective lens.

[0123] Optionally, the light emitting element 101 may further include a deformable prism pair, which is located in the light emitting direction of the collimating prism, and is used to change the polarization property of the emitted light beam.

[0124] In practice, polarized light can be divided into linear polarized light, elliptically polarized light and circularly polarized light according to its properties. The output light beam from the laser transmitter is usually elliptically polarized light. By setting the deformable prism pair in the light output direction of the collimating prism, the polarization property of the output light beam can be adjusted from elliptically polarized light to circularly polarized light.

[0125] The beam splitter 102 is used to split the light beam emitted by the light emitting element 101 into multiple light beams. The beam splitter 102 can be a hot melt taper beam splitter or a PLC planar waveguide beam splitter. The embodiment of the present disclosure does not limit the type of the beam splitter 102.

[0126] The light detector 103 is used to detect the multiple irradiation areas. The light detector 103 may be a four-quadrant photodetector.

[0127] In implementation, the light beam emitted by the light emitting element 101 is divided into multiple light beams by the beam splitter 102, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. The guide light beam is divided into multiple light beams by the beam splitter 102, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. After the multiple light beams contact the guide layer of the optical disc, they are reflected, and the multiple light detectors 103 receive the multiple reflected light beams accordingly, so as to detect the multiple irradiation areas.

[0128] refer to Fig.13The processor 200 is electrically connected to the multiple light detectors 103, and the processor 200 is used to: determine the guidance information based on the detection result of the first light detector 1031 among the multiple light detectors, determine the light product corresponding to each other light detector within a specified time period based on the detection results of other light detectors other than the first light detector 1031, determine the radial offset of the optical head 100 based on the light product corresponding to each other light detector, and perform offset correction on the optical head based on the radial offset.

[0129] The working surface is a surface of the guide layer of the optical disc in the optical drive, and the radial offset includes a point away from the center point of the working surface or a point close to the center point of the working surface.

[0130] The specific process of determining the guidance information based on the detection result of the first light detector 1031 can be referred to above and will not be repeated here.

[0131] Several possible implementations of determining the radial offset of the optical head 100 and correcting the offset of the optical head based on the radial offset are described below:

[0132] The optical head 100 may determine the radial deviation of the optical head 100 via a plurality of optical detectors 103 .

[0133] In some possible embodiments, the optical drive includes three light detectors 103 .

[0134] like Fig.13 As shown, the optical head 100 includes a light emitting element 101 , a beam splitter 102 , a first light detector 1031 , a second light detector 1032 and a third light detector 1033 .

[0135] The structural features of the light emitting element 101 and the beam splitter 102 are the same as above and will not be described again here.

[0136] like Fig.13 and Fig.14 As shown, the beam splitter 102 is used to split the light beam emitted by the light emitting element 101 into three beams, and the three beams respectively form a first irradiation area, a second irradiation area and a third irradiation area on the working surface of the optical drive.

[0137] In implementation, the light intensity in each irradiation area decays in the radial direction, that is, the light intensity near the center point in the irradiation area is higher, and the light intensity away from the center point is lower. In the process of light intensity decaying in the radial direction, there is a detection area concentric with the irradiation area, and the light intensity in the detection area has a significant impact on the detection result of light detection, while the light intensity in the area outside the detection area is small, and the impact on the detection result of the light detector can be ignored. In this example, each irradiation area has a corresponding detection area, that is, the first irradiation area has a first detection area 1031a, the second irradiation area has a second detection area 1032a, and the third irradiation area has a third detection area 1033a. The first light detector 1031, the second light detector 1032, and the third light detector 1033 are used to detect the first detection area 1031a, the second detection area 1032a, and the third detection area 1033a respectively. The processor 200 is used to: determine a first light product within a specified time length based on the detection result of the second light detector 1032, determine a second light product within a specified time length based on the detection result of the third light detector 1033, and determine a radial offset of the optical head 100 based on the first light product and the second light product.

[0138] In one example, the first detection area 1031a, the second detection area 1032a, and the third detection area 1033a are all circular.

[0139] like Fig.14 As shown, the radial width H1 of the second detection area 1032a corresponding to the second light detector 1032 is smaller than the minimum distance H2 from the trough of the waveform to the second groove eaves 112, and the radial width H3 of the third detection area 1033a corresponding to the third light detector 1033 is smaller than the minimum distance H2.

[0140] The distance between the second detection area 1032a and the center point of the working surface is greater than the distance between the third detection area 1033a and the center point of the working surface, that is, the second detection area 1032a is closer to the third detection area 1033a and farther from the center point of the working surface.

[0141] In implementation, when the optical head 100 is on the guide track, the point 1032b in the second detection area 1032a having the largest distance from the center point of the working surface satisfies the first condition, and the point 1033b in the third detection area 1033a having the smallest distance from the center point of the working surface satisfies the second condition, or, when the optical head 100 is on the guide track, point 1032b satisfies the third condition, and point 1033b satisfies the first condition.

[0142] The first condition is to be located on the second gutter eave 112 , the second condition is to be located on a spiral line connecting the wave crest points of the waveform, and the third condition is to be located on a spiral line connecting the wave trough points of the waveform.

[0143] like Fig.14 As shown, since the radial width H1 of the second detection area 1032a is smaller than the distance H2 from the trough of the waveform to the corresponding second trough eaves 112, the radial width H3 of the third detection area 1033a is smaller than the distance H2 from the peak of the waveform to the corresponding second trough eaves 112. It is easy to understand that when the point 1032b in the second detection area 1032a with the largest distance from the center point of the working surface meets the first condition, the point in the second detection area 1032a close to the center point of the working surface has a reference distance with the adjacent second trough eaves 112, and when the point 1033b in the third detection area 1033a with the smallest distance from the center point of the working surface meets the second condition, the point in the third detection area 1033a far from the center point of the working surface also has a reference distance with the adjacent second trough eaves 112.

[0144] refer to Fig.14 and Fig.15 When the guide track does not radially offset, the second detection area 1032a and the third detection area 1033a both fall completely in the shore structure 12. Within a specified time period, the sum of the light product P1 in the third quadrant and the light product P2 in the fourth quadrant is the first light product, and the sum of the light product P3 in the ninth quadrant and the light product P4 in the tenth quadrant is the second light product. The first light product is equal to the second light product.

[0145] When the guide track deviates radially inward: Taking the guide track as being aligned with the groove 11 as an example, since there is a reference distance between the point of the second detection area 1032a close to the center point of the working surface and the adjacent second groove eaves 112, within the specified time length, the sum of the light product P1 of the third quadrant and the light product P2 of the fourth quadrant is the first light product, and the first light product does not change; since the point 1033b in the third detection area 1033a is located on the spiral line connecting the peak points of the waveform, the guide track deviates radially inward, and point 1033b passes the second groove eaves 112 and enters the groove 11. At this time, within the specified time length, the sum of the light product P3 of the ninth quadrant and the light product P4 of the tenth quadrant is the second light product, and the second light product decreases, so the first light product is greater than the second light product. It is easy to understand that when the guide track deviates radially outward, the first light product is less than the second light product.

[0146] Accordingly, the radial offset of the optical head can be determined according to the magnitude relationship between the first light product and the second light product.

[0147] Further, when the first optical product is greater than the second optical product, it can be determined that the guide track is radially deviated inward, that is, the optical head is radially deviated inward, and the processor can send an outward movement signal to the optical head to make the optical head move radially outward to ensure that the guide track is aligned with the groove 11, so as to accurately demodulate the guide information. When the first optical product is less than the second optical product, it can be determined that the guide track is radially deviated outward, that is, the optical head is radially deviated outward, and the processor can send an inward movement signal to the optical head to make the optical head move radially inward to ensure that the guide track is aligned with the groove 11, so as to accurately demodulate the guide information.

[0148] refer to Fig. 20 In the case where the guide track should be aligned with the bank structure 12, the process of determining the radial offset of the optical head and correcting the offset of the optical head based on the radial offset is the same as the above content and will not be repeated here.

[0149] It is easy to understand that the second irradiation area and the third irradiation area only need to meet the above-mentioned position characteristics and size characteristics to achieve the determination of the radial offset of the optical head 100. The embodiment of the present disclosure does not limit the positional relationship between the first irradiation area, the second irradiation area and the third irradiation area.

[0150] The optical head 100 can be offset in the radial direction by a method that determines the radial displacement of the optical head 100.

[0151] In some possible embodiments, the optical drive includes two light detectors 103 .

[0152] like Fig.16 As shown, the optical head 100 includes a light emitting element 101 , a beam splitter 102 , a first light detector 1031 and a second light detector 1032 .

[0153] The structural features of the light emitting element 101 and the beam splitter 102 are the same as above and will not be described again here.

[0154] like Fig.17 As shown, the beam splitter 102 is used to split the light beam emitted by the light emitting element 101 into two light beams, and the two light beams correspond to the first irradiation area and the second irradiation area on the working surface of the optical drive, respectively, and the first irradiation area and the second irradiation area have a first detection area 1031a and a second irradiation area 1032a, respectively. The first light detector 1031 and the second light detector 1032 are used to detect the first detection area 1031a and the second irradiation area 1032a, respectively.

[0155] The processor 200 is used to determine a first light product and a second light product within a specified time period based on the detection result of the second light detector 1032 , and determine a radial offset of the optical head 100 based on the first light product and the second light product.

[0156] In one example, the first illumination area and the second illumination area are both circular. The first light detector 1031 and the second light detector 1032 are both four-quadrant photodetectors.

[0157] The diameter of the first detection area 1031a is greater than the difference between the specified value and the minimum distance H2 from the trough of the waveform to the second gutter eave 112, and the diameter of the second detection area 1032a is equal to the distance H2 from the trough of the waveform to the corresponding second gutter eave 112.

[0158] In implementation, when the laser head is on the guide rail, points in the second detection area 1032a close to and far from the center point of the working surface respectively satisfy the first condition and the third condition, that is, the edge of the second detection area 1032a close to the center of the working surface is tangent to the second groove eave 112, and the edge of the second detection area 1032a far from the center of the working surface is tangent to the trough of the waveform.

[0159] like Fig.17 As shown, in implementation, the sum of the light product amount P2 of the second quadrant and the light product amount P1 of the first quadrant is the first light product amount, and the sum of the light product amount P3 of the third quadrant and the light product amount P4 of the fourth quadrant is the second light product amount.

[0160] In practice, taking the guide track being aligned with the groove 11 as an example, when the guide track deviates radially inward: since the edge of the second detection area 1032a away from the center of the working surface is tangent to the trough of the waveform, within a specified time period, the first light product does not change, and the second light product decreases and does not change periodically. When the guide track deviates radially outward, since the edge of the second detection area 1032a close to the center of the working surface is tangent to the second groove eaves 112, within a specified time period, the second light product does not change, and the first light product changes periodically between decrease and increase.

[0161] Accordingly, the radial offset of the optical head can be determined according to the variation trend of the first light product and the second light product.

[0162] Further, when the first optical product does not change, and the second optical product decreases and does not change periodically, it can be determined that the guide track deviates radially inward, that is, the optical head deviates radially inward, and the processor can send an outward movement signal to the optical head to move the optical head radially outward to ensure that the guide track is aligned with the groove 11, so as to accurately demodulate the guide information. When the second optical product does not change, and the first optical product changes periodically between decrease and increase, it can be determined that the guide track deviates radially outward, that is, the optical head deviates radially outward, and the processor can send an inward movement signal to the optical head to move the optical head radially inward to ensure that the guide track is aligned with the groove 11, so as to accurately demodulate the guide information.

[0163] In the case where the guide track should be aligned with the bank structure 12, the process of determining the radial offset of the optical head and performing offset correction on the optical head based on the radial offset is the same as that described above and will not be repeated here.

[0164] The optical drive provided by the disclosed embodiment is adopted, and the optical head 100 of the optical drive includes a light emitting element 101, a beam splitter 102 and a plurality of light detectors 103. The light beam emitted by the light emitting element 101 is divided into multiple light beams by the beam splitter 102, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. The guide light beam is divided into multiple light beams by the beam splitter 102, and the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive. After the multiple light beams contact the guide layer of the optical disc, they are reflected, and the multiple light detectors 103 receive the multiple reflected light beams correspondingly, so as to detect the multiple irradiation areas. The processor 200 is used to determine the light product corresponding to each other light detector within a specified time period based on the detection results of other light detectors other than the first light detector 1031, determine the radial offset of the optical head 100 based on the light product corresponding to each other light detector, and perform offset correction on the optical head based on the radial offset. Therefore, the optical disc provided by the disclosed embodiment can align the guide track with the groove 11 or the bank structure 12 by adopting the optical drive to accurately demodulate the guide information. In this way, when using the optical disc and the optical drive of the embodiment of the present disclosure, the data storage density of the optical disc can be improved while ensuring the accuracy of the demodulation guide information.

[0165] The embodiment of the present disclosure also provides an optical drive control method. The optical drive control method is applied to an optical drive, and the optical drive can be used to perform a read operation or a write operation on the above optical disc. In the optical disc, the guide layer 1 has a spiral groove 11, the first groove ridge 111 of the groove 11 has a waveform carrying guide information, and the second groove ridge 112 of the groove 11 does not have a waveform. The process of optical drive control can be as follows: Fig.18 The process shown is executed.

[0166] Before introducing the process of optical drive control in detail, we first briefly introduce the definition of the guide track.

[0167] When using the optical drive, optical disc, and optical drive control method provided by the embodiments of the present disclosure, a read / write logic having two guide tracks can be set during the read / write process, wherein the guide track is the movement track of the equivalent center of the light beam emitted by the optical head on the optical disc during the read / write process. Fig.19As shown, there are two guide tracks in the process of reading and writing the optical disc by the optical drive, and the solid line and the dotted line in the figure represent a guide track respectively. One of the guide tracks is the movement trajectory of the equivalent center of the guide light beam emitted by the optical head on the guide layer 1 of the optical disc when the optical head 100 corresponds to the groove 11 in the guide layer 1, and the other guide track is the movement trajectory of the equivalent center of the guide light beam emitted by the optical head on the guide layer 1 of the optical disc when the optical head 100 corresponds to the shore structure 12 in the guide layer 1. It is easy to understand that in the process of reading and writing the optical disc, the optical head only moves in the radial direction, and in the process of moving the optical head 100, the optical head 100 switches between the two guide tracks. The optical drive may include multiple guide tracks. The embodiment of the present disclosure takes two guide tracks as an example to introduce, and the value range of the guide track number can be [0,1].

[0168] The following is a detailed description of the optical drive control process:

[0169] Fig.18 is a flow chart of an optical drive control method provided by an embodiment of the present disclosure, see Fig.18 The process includes:

[0170] Step 1801: The optical drive receives an operation instruction.

[0171] The operation instruction is a read instruction or a write instruction, and the operation instruction carries a first guide track number and a first address number.

[0172] During the process of reading and writing data on the optical disc, the user uses the terminal device to send a read instruction or a write instruction to the optical drive, and the read instruction or the write instruction carries the first guide track number and the first address number. The first guide number is the number of the guide track that the optical head needs to reach during the reading and writing process, and the value of the first guide track number can be "0" or "1".

[0173] Exemplarily, the first guide track number and the first address number may be different fields in one number, or may be two independent numbers.

[0174] Optionally, before executing step 1801, that is, before the optical drive receives an operation instruction, the optical drive first obtains boot information.

[0175] refer to Fig.19During the data writing process of the optical disc, when the optical disc whose recording layer does not store data is placed in the optical drive, the optical drive will first control the optical head to focus the guide beam so that the guide beam is irradiated on the guide layer of the optical disc, and then control the motor 300 to rotate to drive the optical disc to rotate. During this process, the optical drive controls the optical head to move successively following the groove 11 and the bank structure 12 in the guide layer, demodulates the guide information carried by the groove 11 and the bank structure 12 through the first groove eaves 111, and stores the guide information into the cache; during the data reading process of the optical disc, similarly, the optical drive will control the optical head to focus the guide beam, and then control the motor 300 to rotate to drive the optical disc to rotate. During this process, the optical drive controls the optical head to move successively following the groove 11 and the bank structure 12 in the guide layer, demodulates the guide information carried by the groove 11 and the bank structure 12 through the first groove eaves 111, and stores the guide information into the cache.

[0176] The cache may be a cache of the optical drive, or a cache of a processor in a terminal device (eg, a computer) that sends an operation instruction to the optical drive. Then, step 1801 is executed.

[0177] Step 1802: The optical drive controls the optical head to move to a position corresponding to the first guide track number and the first address number.

[0178] In some possible embodiments, in step 1802, the optical drive controls the optical head based on the first guide track number so that the optical head is located on the first guide track.

[0179] After the optical drive demodulates the boot information and stores the boot information into the cache, the optical head may be located on any kind of guide track, that is, the value of the guide track where the optical head is currently located may be "0" or "1".

[0180] In implementation, the optical drive receives an operation instruction carrying a first guide track number, and the first guide track number in the operation instruction may be the same as or different from the guide track number where the optical head is currently located. When the first guide track number in the operation instruction is the same as the guide track number where the optical head is currently located, it indicates that the guide track where the optical head is currently located is the guide track where the user needs the optical head to reach, and when the first guide track number in the operation instruction is different from the guide track number where the optical head is currently located, it indicates that the guide track where the optical head is currently located is different from the guide track where the user needs the optical head to reach.

[0181] refer to Fig.19After the optical drive demodulates the guide information and stores it in the cache, the optical head may be located on the guide track corresponding to the groove 11, or may be located on the track corresponding to the bank structure 12. At this time, the optical drive receives an operation instruction carrying the first guide track number, and the operation instruction indicates that the optical head needs to move to the guide track corresponding to the groove 11, or to the track corresponding to the bank structure 12. At this time, if the optical head is currently located on the guide track corresponding to the groove 11, and the operation instruction indicates that the optical head needs to move to the guide track corresponding to the groove 11, there is no need to move the optical head due to switching the guide track. If the optical head is currently located on the guide track corresponding to the groove 11, and the operation instruction indicates that the optical head needs to move to the guide track corresponding to the bank structure 12, it is necessary to move the optical head so that the optical head moves to the guide track that needs to be reached.

[0182] In one example, if the first guide track is different from the guide track number of the optical head currently located in the guide track where the optical head is currently located, the optical drive controls the optical head to move a specified distance in the radial direction. If the first guide track number is the same as the guide track number of the optical head currently located in the guide track where the optical head is currently located, the position of the optical head is kept unchanged.

[0183] The optical drive controlling the optical head to move radially means that the optical drive controls the optical head to move in the radial direction of the optical disc, the radial direction includes radially inward and radially outward, and the specified distance is an odd multiple of the track pitch.

[0184] Exemplarily, the specified distance may be equal to the pitch of the guide rails.

[0185] In some possible embodiments, in step 1802, after the optical head is located on the first guide track, the optical drive controls the optical head to move to a position on the first guide track corresponding to the first address number.

[0186] During the reading and writing process, each time the guide light beam passes through a storage address, the optical drive can demodulate the address number of the current storage address from the waveform in the first groove 111. The address number of the storage address swept by the guide light beam currently emitted by the optical head is called the second address number. The value range of the second address number is related to the total storage space size of the optical disc.

[0187] Exemplarily, the value range of the second address number may be [0, 20000].

[0188] In practice, when the optical drive receives an address number carrying an operation instruction, the optical head may be located at any storage address, and the first address number and the second address number in the operation instruction may be the same or different. When the first address number and the second address number in the operation instruction are the same, it means that the storage address currently located by the optical head is the storage address that the user needs the optical head to reach. When the first address number and the second address number in the operation instruction are different, it means that the storage address currently located by the optical head is different from the storage address that the user needs the optical head to reach. At this time, the optical drive needs to move the optical head to move it to the storage address that needs to be reached.

[0189] In one example, the optical drive determines a second address number corresponding to a current position of the optical head, determines a difference between the first address number and the second address number, and controls movement of the optical head based on the difference.

[0190] The difference between the first address number and the second address number is the difference obtained by subtracting the second address number from the first address number.

[0191] Exemplarily, the optical drive receives an operation instruction with a first address number, for example, the first address number in the operation instruction is "3523". At the same time, the optical drive demodulates the address number of the current storage address from the waveform in the first groove 111, and records it as the second address number. For example, the optical drive demodulates the second address number from the waveform in the first groove 111 as "2023". Therefore, by subtracting the second address number from the first address number, it can be determined that the difference between the first address number and the second address number is "1500". Based on the difference, the optical drive controls the movement of the optical head to move the optical head to the position on the first guide track corresponding to the first address number.

[0192] Optionally, when the difference is less than a first preset value, the optical drive controls the optical head to move along the first guide track. When the difference is greater than or equal to the first preset value and less than a second preset value, the optical drive controls the optical head to move via a voice coil motor. When the difference is greater than or equal to the second preset value, the optical drive controls the optical head to move as a whole.

[0193] The first preset value is smaller than the second preset value.

[0194] In implementation, when the difference between the first address number and the second address number is less than the first preset value, the storage address corresponding to the first address number and the storage address corresponding to the second address number are very close. At this time, the optical drive only needs to control the optical head to follow the first guide track. As the optical disc rotates, the optical head can move to the position corresponding to the first address number. When the difference between the first address number and the second address number is greater than or equal to the first preset value and less than the second preset value, there is a distance between the storage address corresponding to the first address number and the storage address corresponding to the second address number. The distance is large, for example, the distance is less than the distance corresponding to the overall movement of the optical head by one unit length. If the optical drive directly controls the overall movement of the optical head, the second address number at which the optical head is located after moving one unit length may be greater than the first address number, and then the position of the optical head needs to be adjusted in the reverse direction. Therefore, the voice coil motor can be used to control the movement of the optical head to improve the adjustment accuracy. When the difference between the first address number and the second address number is greater than the second preset value, there is a distance between the storage address corresponding to the first address number and the storage address corresponding to the second address number. The distance is greater than the distance corresponding to the overall movement of the optical head by one unit length. At this time, the optical drive controls the overall movement of the optical head to improve the adjustment efficiency.

[0195] The specific values ​​of the first preset value and the second preset value can be set according to actual parameters of the optical drive, and the embodiment of the present disclosure does not limit this.

[0196] In implementation, after the optical drive controls the movement of the optical head based on the difference, the second address number corresponding to the position reached by the moved optical head may still be different from the first address number. Therefore, after executing the control of the movement of the optical head based on the difference, it is possible to switch to the processing of determining the second address number corresponding to the current position of the optical head, and continue to adjust the position of the optical head to control the optical head to move to the position on the first guide track corresponding to the first address number.

[0197] Step 1803: Execute a read operation or a write operation based on the operation instruction.

[0198] In implementation, the operation instruction is a read instruction or a write instruction. When the operation instruction is a read instruction, the optical drive performs a read operation based on the operation instruction. When the operation instruction is a write instruction, the optical drive performs a write operation based on the operation instruction.

[0199] In step 1803, the optical drive controls the optical head to move along the first guide track currently located and performs a read operation or a write operation.

[0200] In implementation, after the optical drive controls the optical head to move to the position corresponding to the first address number on the first guide track, the optical drive performs a read operation and a write operation on the position corresponding to the first address number in the recording layer of the optical disc.

[0201] In one example, after the optical head moves to the position corresponding to the first guide track number and the third address number to perform a read operation or a write operation, if the operation instruction has not been completed, the optical head is controlled to move to the position corresponding to the second guide track number and the fourth address number. The optical head is controlled to move along the second guide track currently located and perform a read operation or a write operation.

[0202] The third address number is the tail address number, and the fourth address number is the head address number. The second guide track number corresponds to a different guide track from the first guide track number, that is, if the first guide track is track 0, the second guide track is track 1, and if the first guide track is track 1, the second guide track is track 0.

[0203] In implementation, the operation instruction includes the first guide track number and the first address number, as well as the required read and write data capacity.

[0204] Exemplarily, taking the data writing process as an example, the optical disc guide layer has a total of 20,000 storage addresses, and the groove and land structures respectively have 10,000 storage addresses. The operation instruction includes the first guide track number "0" and the first address number "9989", and the write data capacity is 1GB. Assuming that the guide track corresponding to the groove is guide track No. 0, the recording layer storage area where data is written starts corresponding to the storage address with address number 9989 on guide track No. 0 of the guide layer. Including storage address No. 9989, there are 12 storage addresses in guide track No. 0 that can be used to record guide information, and there are 12 storage areas in the recording layer that can be used to store data. If the storage capacity of these 12 storage areas is less than the data capacity that needs to be read and written, that is, the storage capacity of these 12 storage areas is less than 1GB, then after the optical head moves to the position corresponding to the third address number for a write operation, the write operation cannot be completed, and there is still data that needs to be written. At this time, the optical drive controls the optical head to move to the position corresponding to guide track No. 1 and the fourth address number, that is, the optical drive controls the optical head to move to the first storage address of another guide track, and continues to perform the write operation at the position corresponding to the first storage address of another guide track in the recording layer, thereby completely writing the data to be written.

[0205] With the optical drive control method provided by the embodiment of the present disclosure, the optical drive receives an operation instruction, and the operation instruction carries not only the first address number but also the first guide track number. The position of the optical head is no longer moved only according to the address number, but is moved according to the guide track number and the address number at the same time. In this way, for an optical disc whose read / write logic is to be provided with multiple guide tracks during the reading and writing process, the reading operation and the writing operation can still be effectively completed, thereby expanding the application scope of the optical drive.

[0206] The above description is only one embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the scope and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. An optical disc, characterized in that: The optical disc comprises a guide layer (1) and a recording layer (2); The guide layer (1) is connected to the recording layer (2), the guide layer (1) has a spiral groove (11), a first groove eave (111) of the groove (11) has a waveform, the waveform is used to carry guide information, and a second groove eave (112) of the groove (11) does not have a waveform; The recording layer (2) is used to store data.

2. The optical disc according to claim 1, characterized in that The second groove eaves (112) are spiral lines.

3. The optical disc according to claim 1 or 2, characterized in that: The center line (113) of the waveform is a spiral line.

4. The optical disc according to any one of claims 1 to 3, characterized in that: The waveform is a cosine wave.

5. The optical disc according to any one of claims 1 to 4, characterized in that: The center line (113) of the waveform is equidistant from the second groove eaves (112) on both sides.

6. The optical disc according to any one of claims 1 to 5, characterized in that: The distance between two points included in any radially adjacent point pair (1121) in the second groove eaves (112) is equal to a specified value, wherein the radially adjacent point pair (1121) is two adjacent intersection points among multiple intersection points of the same radius of the optical disc and the second groove eaves (112).

7. The optical disc according to claim 6, characterized in that The specified value is greater than or equal to twice the read / write unit width corresponding to the optical disc.

8. An optical drive, characterized in that: The optical drive is used to perform a read operation or a write operation on an optical disc, the guide layer (1) of the optical disc has a spiral groove (11), the first groove flange (111) of the groove (11) has a waveform carrying guide information, and the second groove flange (112) of the groove (11) does not have a waveform, and the optical drive comprises an optical head (100) and a processor (200); The optical head (100) comprises a light emitting element (101), a beam splitter (102) and a plurality of light detectors (103); The beam splitter (102) is used to split the light beam emitted by the light emitting element (101) into multiple light beams, wherein the multiple light beams correspond to multiple irradiation areas on the working surface of the optical drive, and the working surface is the surface of the optical drive corresponding to the guide layer of the optical disc; The multiple light detectors (103) are used to detect the multiple irradiation areas; The processor (200) is used to: determine the guide information based on the detection result of the first light detector (1031) among the multiple light detectors; determine the light product corresponding to each other light detector within a specified time period based on the detection results of other light detectors other than the first light detector (1031); determine the radial offset of the optical head (100) relative to the guide track based on the light product corresponding to each other light detector; and perform offset correction on the optical head based on the radial offset.

9. The optical drive according to claim 8, characterized in that: The plurality of light detectors (103) further include a second light detector (1032) and a third light detector (1033); The radial width H1 of the second detection area (1032a) corresponding to the second light detector (1032) is smaller than the minimum distance H2 from the trough of the waveform to the second groove eaves (112), and the radial width H3 of the third detection area (1033a) corresponding to the third light detector (1033) is smaller than the minimum distance H2; The distance between the second detection area (1032a) and the center point of the working surface is greater than the distance between the third detection area (1033a) and the center point of the working surface; When the optical head (100) is on the guide track, the point (1032b) in the second detection area (1032a) with the largest distance from the center point of the working surface satisfies the first condition, and the point (1033b) in the third detection area (1033a) with the smallest distance from the center point of the working surface satisfies the second condition, or, when the optical head (100) is on the guide track, the point (1032b) satisfies the third condition, and the point (1033b) satisfies the first condition; wherein the first condition is to be located on the second groove eaves (112), the second condition is to be located on a spiral line connecting the peak points of the waveform, and the third condition is to be located on a spiral line connecting the trough points of the waveform.

10. The optical drive according to claim 9, characterized in that: The processor (200) is used for: A first light product within a specified time length is determined based on the detection result of the second light detector (1032), a second light product within the specified time length is determined based on the detection result of the third light detector (1033), and a radial offset of the optical head is determined based on the magnitude relationship between the first light product and the second light product.

11. A method for controlling an optical drive, characterized in that: The method comprises: Receiving an operation instruction, the operation instruction being a read instruction or a write instruction, the operation instruction carrying a first guide track number and a first address number, the operation instruction being used to instruct the optical drive to perform a read operation or a write operation on an optical disc, the guide layer (1) of the optical disc having a spiral groove (11), a first groove flange (111) of the groove (11) having a waveform carrying guide information, and a second groove flange (112) of the groove (11) having no waveform; Controlling the optical head to move to a position corresponding to the first guide track number and the first address number; A read operation or a write operation is performed based on the operation instruction.

12. The method according to claim 11, characterized in that The controlling the optical head to move to a position corresponding to the first guide track number and the first address number comprises: Controlling the optical head based on the first guide track number so that the optical head is located on the first guide track; The optical head is controlled to move to a position on the first guide track corresponding to the first address number.

13. The method according to claim 12, characterized in that The controlling the optical head based on the first guide track number so that the optical head is located on the first guide track includes: If the first guide track number is different from the guide track number of the guide track currently located by the optical head, controlling the optical head to move a specified distance in the radial direction, wherein the specified distance is an odd multiple of the track pitch; If the first guide track number is the same as the guide track number of the guide track where the optical head is currently located, the position of the optical head is kept unchanged.

14. The method according to claim 12 or 13, characterized in that The step of controlling the optical head to move to a position on the first guide track corresponding to the first address number comprises: Determine a second address number corresponding to the current position of the optical head; determining a difference between the first address number and the second address number; The movement of the optical head is controlled based on the difference, and the process of determining the second address number corresponding to the current position of the optical head is executed.

15. The method according to any one of claims 11 to 14, characterized in that: The performing a read operation or a write operation based on the operation instruction comprises: Controlling the optical head to move along the first guide track currently located and perform a read operation or a write operation; After the optical head moves to the position corresponding to the first guide track number and the third address number to perform a read operation or a write operation, if the operation instruction has not been executed, the optical head is controlled to move to the position corresponding to the second guide track number and the fourth address number, wherein the second guide track number and the first guide track number correspond to different guide tracks, the third address number is a tail address number, and the fourth address number is a head address number; The optical head is controlled to move along the second guide track where it is currently located and perform a read operation or a write operation.

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