Optical storage medium multi-layer reading system and error correction method
By forming multi-layered light spots in the optical storage medium and maintaining the conjugate relationship between the object and the image, the problem of slow read and write speed in optical storage systems is solved, achieving efficient multi-layered data reading, which is suitable for the industrialization of high-density optical storage technology.
Patent Information
- Application Number
- CN202512023763.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-17
AI Technical Summary
Existing high-capacity optical storage systems have slow data read and write speeds, and surface read/write optical storage technology systems are complex, costly, and bulky, which is not conducive to commercialization.
The system employs a light source module, a focusing imaging module, first and second readout modules, a focusing servo module, and a correction module. The focusing imaging module forms multi-layered light spots inside the optical storage medium, and the focusing servo module and correction module maintain the conjugate relationship between the detector and the object image on the data recording layer. By using a beam splitting optical path design and a compensation mirror to correct the optical path, the system achieves synchronous readout of multi-layered data.
It significantly improves the information reading speed and efficiency of optical storage devices, has a simple system structure, and is suitable for the industrial application of high-density optical storage technology.
Smart Images
Figure CN121884874A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical storage technology, and in particular to a multi-layer reading system for optical storage media and an error correction method. Background Technology
[0002] Currently, the storage capacity of large-capacity optical storage systems on the market has reached a relatively high level, but the data read and write speed is still relatively slow, which restricts the development of optical storage technology.
[0003] In recent years, a surface read / write optical storage technology has emerged. Its data reading principle involves using a surface light source or spatial light modulator to generate a surface light source. This surface light source is then imaged onto the optical disc's recording layer using an imaging optical system to form an image of the surface light source. After the image of the surface light source carries the optical disc's data information, it is reflected off the recording layer and then imaged onto a data receiving detector by the surface imaging system to generate surface read data. This method can improve data read / write speeds, but the system is overly complex, costly, and bulky, hindering commercialization. Summary of the Invention
[0004] This invention provides a multi-layer reading system for optical storage media and an error correction method to overcome the above-mentioned technical problems.
[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A multi-layer reading system for optical storage media includes: a light source module, a focusing imaging module, a first reading module, a second reading module, a focusing servo module, and a correction module; The light source module is used to emit a parallel beam of light to the focusing imaging module; The focusing imaging module is used to focus the parallel beam onto the interior of the optical storage medium to form a first read surface spot for illuminating the first data recording layer in the optical storage medium and a second read surface spot for illuminating the second data recording layer in the optical storage medium. Furthermore, the focusing imaging module is also used to project the first reflective surface spot and the second reflective surface spot onto the first reading module and the second reading module, respectively; wherein, the first reflective surface spot is the first reading surface spot reflected by the first data recording layer, and the second reflective surface spot is the second reading surface spot reflected by the second data recording layer; The first reading module includes a first detector and is capable of reading the light spot on the first reflective surface through the first detector; The second reading module includes a second detector and is capable of reading the light spot on the second reflective surface through the second detector; The focusing servo module is used to adjust the position of the optical disc so that the first detector and the first data recording layer are in and maintain a conjugate relationship between the object and the image; The correction module is used to adjust the optical path from the second reflective surface spot to the second detector so that the second detector and the second data recording layer are in and maintain an object-image conjugate relationship. Furthermore, the focusing imaging module includes a first semi-transparent mirror and an objective lens; The specific process by which the focusing imaging module focuses the parallel beam onto the interior of the optical storage medium to form a first read surface spot for illuminating the first data recording layer in the optical storage medium and a second read surface spot for illuminating the second data recording layer in the optical storage medium includes: The incident parallel light beam is reflected to the objective lens by the first semi-transparent and semi-reflective mirror, and the incident light is refracted into the interior of the optical storage medium by the objective lens, thereby forming a first read surface spot and a second read surface spot on the first data recording layer and the second data recording layer located before and after the focal point inside the optical storage medium, respectively. The specific process by which the focusing imaging module projects the first reflective surface spot and the second reflective surface spot onto the first reading module and the second reading module, respectively, includes: The objective lens refracts the light spots from the first and second reflective surfaces onto the first semi-transparent mirror, and the first semi-transparent mirror projects the incident light onto the first and second reading modules respectively. Furthermore, the first reading module also includes a second semi-transparent and semi-reflective mirror; The specific process by which the first reading module reads the light spot on the first reflective surface includes: The second semi-transparent mirror reflects the light spot projected by the first semi-transparent mirror onto the first detector, so as to form an image on the first detector.
[0006] Furthermore, the second reading module also includes a reflector; The correction module is a compensation mirror, and the compensation mirror is located between the second detector and the reflector; The specific process by which the second reading module reads the light spot on the second reflective surface includes: The reflector reflects the light spot projected by the second reflective surface of the first semi-transparent and semi-reflective mirror to the compensating mirror; The incident light is refracted to the second detector by the compensation mirror to form an image on the second detector.
[0007] Furthermore, the light source module includes a point light source and a collimating lens; The point light source is used to emit monochromatic laser light; The collimating lens is used to collimate the incident monochromatic laser into the parallel beam.
[0008] A method for error correction in a multi-layer reading system for optical storage media, comprising the following steps: S1. The initial position of the optical storage medium is adjusted by the focusing servo module so that the imaging size of the first reflective surface spot and the second reflective surface spot on the first detector and the second detector both conform to the set size. S2. During the actual reading of the optical disc, check whether the size of the light spot imaged by the first detector and the second detector both conform to the set size. If not, execute S3; if yes, execute S5. S3. The position of the optical disc is adjusted along the optical axis by the focusing servo module so that the first detector and the first data recording layer restore the conjugate relationship between the object and the image. S4. Based on the size of the light spot imaged by the second detector, adjust the position of the correction module along the optical axis to change the optical path from the second reflective surface light spot to the second detector, so that the second detector and the second data recording layer restore the conjugate relationship between the object and the image. S5. Continue reading the optical disc and continuously detect the size of the light spot imaged by the first and second detectors. Beneficial Effects: This invention uses a focusing imaging module to focus a parallel light beam onto the interior of an optical storage medium, forming a first read surface spot for illuminating the first data recording layer and a second read surface spot for illuminating the second data recording layer. The reflected light spots are read by a first read module and a second read module. A focusing servo module adjusts the position of the optical disc to maintain a conjugate object-image relationship between the first detector and the first data recording layer. A correction module adjusts the optical path from the second reflect surface spot to the second detector to maintain a conjugate object-image relationship between the second detector and the second data recording layer. Through precise optical path design and control of the object-image conjugate relationship, this invention achieves synchronous, interference-free reading of the two data recording layers inside an optical disc using a traditional point light source, significantly improving the information reading speed and efficiency of optical storage devices. It also boasts advantages such as simple structure and system stability, providing a core solution for the industrial application of high-density optical storage technology. Attached Figure Description
[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0010] Figure 1 This is a schematic diagram of the structure of a multi-layer reading system for optical storage media according to the present invention; Figure 2 This is a flowchart of the optical path of the light spot on the first reflective surface in an embodiment of the present invention; Figure 3 This is a flowchart of the optical path of the second reflective surface spot in an embodiment of the present invention; Figure 4 This is a schematic diagram of the array data readout of the first reflective surface light spot on the first detector in an embodiment of the present invention; Figure 5 This is a schematic diagram illustrating the overlap between imaging data in an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating an error occurring in the multi-layer reading system of the optical storage medium in an embodiment of the present invention.
[0011] In the picture: 1. Light source module; 11. Point light source; 12. Collimating lens; 2. Focusing imaging module; 21. First semi-transparent mirror; 22. Objective lens; 3. First reading module; 31. First detector; 32. Second semi-transparent mirror; 33. Imaging of the light spot on the first reflecting surface; 34. Diffusion spot of the light spot on the second reflecting surface; 4. Second reading module; 41. Second detector; 42. Reflector; 5. Calibration module; 6. First data recording layer; 61. First reading surface spot; 7. Second data recording layer; 71. Second readout surface spot; 72. Theoretical location of the second data recording layer; 8. Optical storage media. Detailed Implementation
[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0013] This embodiment provides a multi-layer reading system for optical storage media, such as... Figure 1 As shown, it includes: light source module 1, focusing imaging module 2, first reading module 3, second reading module 4, focusing servo module (not shown in the figure) and correction module 5; The light source module 1 is used to emit a parallel light beam to the focusing imaging module 2; like Figure 2 and Figure 3As shown, the focusing imaging module 2 is used to focus the parallel beam onto the interior of the optical storage medium 8 to form a first read surface spot 61 for illuminating the first data recording layer 6 in the optical storage medium and a second read surface spot 71 for illuminating the second data recording layer 7 in the optical storage medium. Furthermore, the focusing imaging module 2 is also used to project the first reflective surface spot and the second reflective surface spot onto the first reading module 3 and the second reading module, respectively; wherein, the first reflective surface spot is the first reading surface spot reflected by the first data recording layer 6, and the second reflective surface spot is the second reading surface spot reflected by the second data recording layer 7; The first reading module 3 includes a first detector 31, and is capable of reading the light spot on the first reflective surface through the first detector 31; The second reading module 4 includes a second detector 41, and is capable of reading the light spot on the second reflective surface through the second detector 41; The focusing servo module is used to adjust the position of the optical disc so that the first detector 31 and the first data recording layer 6 are in and maintain a conjugate relationship between the object and the image; The correction module 5 is used to adjust the optical path from the second reflective surface spot to the second detector 41 so that the second detector 41 and the second data recording layer 7 are in and maintain a conjugate relationship between the object and the image.
[0014] Specifically, such as Figures 1 to 3 As shown, in this embodiment, the parallel light beam is reflected by the first semi-transparent mirror 21 and then incident on the objective lens 22. The light spot on the first reflective surface is reflected by the first data recording layer 6 and then sequentially projected through the objective lens 22, the first semi-transparent mirror 21, and the second semi-transparent mirror 32, finally forming an image on the first detector 31. The light spot on the second reflective surface is reflected by the second data recording layer 7 and then sequentially transmitted through the objective lens 22, the first semi-transparent mirror 21, the second semi-transparent mirror 32, the reflector 42, and the compensating mirror, finally forming an image on the second detector, thereby achieving synchronous data reading from the two recording layers.
[0015] In a specific embodiment, the focusing imaging module 2 includes a first semi-transparent mirror 21 and an objective lens 22; The specific process by which the focusing imaging module 2 focuses the parallel beam onto the interior of the optical storage medium to form a first read surface spot for illuminating the first data recording layer in the optical storage medium and a second read surface spot for illuminating the second data recording layer in the optical storage medium includes: The incident parallel light beam is reflected to the objective lens 22 by the first semi-transparent and semi-reflective mirror 21, and the incident light is refracted into the interior of the optical storage medium by the objective lens 22, thereby forming a first read surface spot and a second read surface spot in the first data recording layer 6 and the second data recording layer 7 located before and after the focal point inside the optical storage medium, respectively. The specific process by which the focusing imaging module 2 projects the first reflective surface spot and the second reflective surface spot onto the first reading module and the second reading module, respectively, includes: The objective lens 22 refracts the light spots from the first and second reflective surfaces onto the first semi-transparent mirror 21, and the first semi-transparent mirror 21 projects the incident light onto the first reading module 3 and the second reading module 4, respectively. In a specific embodiment, the first reading module 3 further includes a second semi-transparent and semi-reflective mirror 32; The specific process by which the first reading module 3 reads the light spot on the first reflective surface includes: The second semi-transparent mirror 32 reflects the light spot projected by the first semi-transparent mirror onto the first detector 31, so as to form an image on the first detector. Figure 4 As shown.
[0016] In a specific embodiment, the second reading module 4 further includes a reflector 42; The correction module 5 is a compensation mirror, and the compensation mirror is located between the second detector 41 and the reflector 42; The specific process by which the second reading module 4 reads the light spot on the second reflective surface includes: The second reflective surface spot projected by the first semi-transparent and semi-reflective mirror is reflected to the compensation mirror through the reflector 42; The incident light is refracted to the second detector 41 by the compensation mirror to form an image on the second detector.
[0017] Specifically, in this embodiment, a portion of the light reflected by the second reflective surface spot is also reflected onto the first detector 31 via the second semi-transparent mirror 32. However, since the second reflective surface spot and the first detector 31 are not conjugate, their array data recording information will not be precisely imaged on the first detector 31. Instead, a relatively low-intensity diffuse spot 34 is superimposed on the first detector 31, which will not significantly affect the high-intensity recording information (image 33 of the first reflective surface spot) formed by the first reflective surface spot. Figure 4 As shown. Similarly, the first reflective surface spot and the second detector 41 are not conjugates, and their array data recording information will not significantly affect the high light intensity recording information formed by the second reflective surface spot on the second detector 41, thus enabling multi-layer data reading without mutual interference.
[0018] Specifically, in this embodiment, both the first semi-transparent mirror 21 and the second semi-transparent mirror 32 are coated beam splitters, and the beam splitting ratio (i.e., the ratio of reflected light intensity to transmitted light intensity) can be dynamically adjusted according to the reflectivity of the optical disc recording layer. For example, for the second data recording layer with low reflectivity, the transmission ratio of the second semi-transparent mirror 32 can be increased to 70% to ensure that sufficient light energy reaches the subsequent optical path.
[0019] In a specific embodiment, the light source module 1 includes a point light source 11 and a collimating lens 12; The point light source 11 is used to emit monochromatic laser light; The collimating lens 12 is used to collimate the incident monochromatic laser into the parallel beam.
[0020] This embodiment also provides a method for error correction in a multi-layer readout system for optical storage media, characterized in that the specific steps include: S1. The initial position of the optical storage medium is adjusted by the focusing servo module so that the imaging size of the first reflective surface spot and the second reflective surface spot on the first detector 31 and the second detector 41 both conform to the set size. S2. During the actual reading of the optical disc, check whether the size of the light spot imaged by the first detector 31 and the second detector 41 both conform to the set size. If not, execute S3; if yes, execute S5. S3. The position of the optical disc is adjusted along the optical axis by the focusing servo module so that the first detector 31 and the first data recording layer 6 restore the object-image conjugate relationship. S4. Based on the size of the light spot imaged by the second detector, adjust the position of the correction module 5 along the optical axis to change the optical path from the second reflective surface light spot to the second detector, so that the second detector 41 and the second data recording layer 7 restore the object-image conjugate relationship. S5. Continue reading the optical disc and continuously detect the size of the light spot imaged by the first and second detectors. Specifically, in this embodiment, before reading the optical disc, the position of the optical disc is initially adjusted by the focusing servo module so that the imaging sizes of the first reflective surface spot and the second reflective surface spot on the first detector 31 and the second detector 41 both conform to the set size. However, during the actual reading process of the optical disc, due to movement errors and slight jitter when the optical disc rotates at high speed, it is difficult to ensure that the target recording layer is always in the preset position. This results in the surface spot and the detector being in a non-conjugate relationship, and the surface spot data cannot form a clear image on the detector. Figure 5As shown, data overlap can occur, affecting subsequent data decoding. To address this issue, this embodiment determines whether the data recording layer and the detector are in an object-image conjugate state by judging whether the size of the light spot on the detector matches the ideal light spot. Specifically: if the recording layer is close to the objective lens, the size of the light spot imaged by the detector will be larger than the ideal light spot; if the recording layer is far from the objective lens, the size of the light spot imaged by the detector will be smaller than the ideal light spot. When adjustments are needed based on the detection results, the focusing servo module dynamically adjusts the position of the optical disc recording layer by moving the optical disc along the optical axis, ensuring that the recording layer is always in a conjugate position with the detector. When the focusing servo module moves the optical disc along the optical axis, the upper and lower working recording layers move the same distance. If the relative distance between the two layers in the optical disc is strictly equal to the theoretical distance between the two surface spots, it can be guaranteed that the surface spots of the two recording layers and the corresponding detectors are always in an accurate conjugate state during the movement of the optical disc. That is, if the first detector 31 and the first data recording layer 6 are in an object-image conjugate relationship, then the second detector 41 and the second data recording layer 7 will also be in an object-image conjugate relationship. However, in the actual optical disc manufacturing process, due to manufacturing deviations (such as the deviation between the actual position of the second data recording layer 7 and the theoretical position 72 of the second data recording layer), it is difficult to guarantee that the distance between the two layers is exactly equal to the theoretical design value. This situation will cause that no matter how the optical disc moves along the axial direction, because the two layers move the same distance, only one recording layer can be in a conjugate imaging state with the detector, and the other layer can never be conjugate with its detector. Figure 6 As shown. To solve this problem, this embodiment uses the first data recording layer 6 as the reference layer. The focusing servo module ensures that the first detector 31 and the first data recording layer 6 are in a conjugate relationship. If, due to the interlayer distance error of the optical disc, the second data recording layer and the second detector 41 are not in a conjugate imaging relationship, the compensation mirror is adjusted along the optical axis according to the spot size on the second detector 41 to restore the conjugate imaging relationship between the second data recording layer 7 and the second detector 41. This solves the problem that the data of the two recording layers cannot be read accurately at the same time due to the manufacturing deviation of the optical disc. Specifically, in this embodiment, the optical path difference of the reflected beam from the second data recording layer 7 is corrected by a compensation mirror: Since the second data recording layer 7 is located deeper in the optical disc, the optical path of its reflected beam to the second detector 41 is longer than that from the first data recording layer 6 to the first detector 31. The compensation mirror can adjust the optical path length to ensure the phase consistency of the beam and avoid image blurring. In summary, this embodiment utilizes the object-image conjugate relationship and beam splitting optical path design to ensure that when the first and second reflective surface spots are imaged on the corresponding detectors, the non-conjugate spots form low-intensity diffuse spots, guaranteeing no interference with valid data. Combined with the position adjustment of the focusing servo module and the optical path correction of the compensation mirror, it solves the imaging problems caused by optical disc movement errors and interlayer manufacturing deviations. Ultimately, it achieves synchronous and interference-free reading of the two data recording layers of the optical disc, improving the information reading speed and efficiency of optical storage devices, and is suitable for the industrial application of high-density optical storage technology.
[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A multi-layered surface reading system for optical storage media, characterized by include: Light source module (1), focusing imaging module (2), first reading module (3), second reading module (4), focusing servo module and correction module (5); The light source module (1) is used to emit a parallel beam of light to the focusing imaging module (2); The focusing imaging module (2) is used to focus the parallel beam onto the interior of the optical storage medium (8) to form a first reading surface spot (61) for illuminating the first data recording layer (6) in the optical storage medium and a second reading surface spot (71) for illuminating the second data recording layer (7) in the optical storage medium. Furthermore, the focusing imaging module (2) is also used to project the first reflective surface spot and the second reflective surface spot onto the first reading module (3) and the second reading module respectively; wherein, the first reflective surface spot is the first reading surface spot (61) reflected by the first data recording layer (6), and the second reflective surface spot is the second reading surface spot (71) reflected by the second data recording layer (7). The first reading module (3) includes a first detector (31) and is able to read the light spot on the first reflective surface through the first detector (31); The second reading module (4) includes a second detector (41) and is capable of reading the second reflective surface light spot through the second detector (41); The focusing servo module is used to adjust the position of the optical disc so that the first detector (31) and the first data recording layer (6) are in and maintain a conjugate relationship between the object and the image; The correction module (5) is used to adjust the optical path from the second reflective surface spot to the second detector (41) so that the second detector (41) and the second data recording layer (7) are in and maintain an object-image conjugate relationship.
2. The multi-layer reading system for optical storage media according to claim 1, characterized in that, The focusing imaging module (2) includes a first semi-transparent mirror (21) and an objective lens (22). The specific process by which the focusing imaging module (2) focuses the parallel beam onto the interior of the optical storage medium to form a first read surface spot for illuminating the first data recording layer in the optical storage medium and a second read surface spot for illuminating the second data recording layer in the optical storage medium includes: The incident parallel light beam is reflected to the objective lens (22) by the first semi-transparent mirror (21), and the incident light is refracted into the interior of the optical storage medium by the objective lens (22), thereby forming a first read surface spot and a second read surface spot on the first data recording layer (6) and the second data recording layer (7) located before and after the focal point inside the optical storage medium, respectively. The specific process by which the focusing imaging module (2) projects the first reflective surface spot and the second reflective surface spot onto the first reading module and the second reading module, respectively, includes: The objective lens (22) refracts the light spots of the first and second reflective surfaces to the first semi-transparent mirror (21), and the incident light is projected to the first reading module (3) and the second reading module (4) through the first semi-transparent mirror (21).
3. The multi-layer reading system for optical storage media according to claim 1, characterized in that, The first reading module (3) also includes a second semi-transparent and semi-reflective mirror (32); The specific process by which the first reading module (3) reads the light spot on the first reflective surface includes: The first reflective surface light spot projected by the first semi-transparent mirror is reflected to the first detector (31) by the second semi-transparent mirror (32) so as to form an image on the first detector.
4. The multi-layer reading system for optical storage media according to claim 3, characterized in that, The second reading module (4) also includes a reflector (42); The correction module (5) is a compensation mirror, and the compensation mirror is located between the second detector (41) and the reflector (42); The specific process by which the second reading module (4) reads the light spot on the second reflective surface includes: The second reflective surface spot projected by the first semi-transparent and semi-reflective mirror is reflected to the compensating mirror through the reflector (42); The incident light is refracted to the second detector (41) by the compensation mirror to form an image on the second detector.
5. The multi-layer reading system for optical storage media according to claim 1, characterized in that, The light source module (1) includes a point light source (11) and a collimating lens (12); The point light source (11) is used to emit monochromatic laser light; The collimating lens (12) is used to collimate the incident monochromatic laser into the parallel beam.
6. A method for error correction in the multi-layer readout system of optical storage media according to claims 1-5, characterized in that, The specific steps include: S1. The initial position of the optical storage medium is adjusted by the focusing servo module so that the imaging size of the first reflective surface spot and the second reflective surface spot on the first detector (31) and the second detector (41) both conform to the set size. S2. During the actual reading of the optical disc, check whether the size of the light spot imaged by the first detector (31) and the second detector (41) both meet the set size. If not, execute S3; if yes, execute S5. S3. The position of the optical disc is adjusted along the optical axis by the focusing servo module so that the first detector (31) and the first data recording layer (6) restore the object-image conjugate relationship; S4. According to the size of the light spot imaged by the second detector, adjust the position of the correction module (5) along the optical axis to change the optical path from the second reflective surface light spot to the second detector, so that the second detector (41) and the second data recording layer (7) restore the object-image conjugate relationship; S5. Continue reading the optical disc and continuously detect the size of the light spot imaged by the first and second detectors.