WO2025039910A1 - Single-servo-layer multi-recording-layer optical disc drive, memory, and electronic device - Google Patents

Abstract

A single-servo-layer multi-recording-layer optical disc drive, a memory, and an electronic device. A dichroic mirror is provided in the optical disc drive. A light beam of a first light source is projected on the surface of one side of the dichroic mirror and then is reflected to a recording medium of an optical disc to read and write data. A light beam of a second light source may directly transmit through the dichroic mirror and be transmitted to a servo layer of the recording medium of the optical disc. The dichroic mirror can be fixed in the optical disc drive by means of a movable assembly. The movable assembly can change the orientation of the dichroic mirror to adjust the relative position between a propagation direction of the light beam of the first light source and a propagation direction of the light beam of the second light source, so as to eliminate errors generated in the processes of installation, use and the like of the optical disc drive. The optical disc drive of the present application has the advantages of small internal structure change, simple implementation process, high control precision and the like, and the effect that while accurate servo of the light beam of the second light source in the servo layer is implemented, the light beam of the first light source is projected to a data track center of each recording layer of the optical disc is realized at low costs.

Description

Single-servo-layer multi-recording-layer optical disc drive, storage device and electronic device

This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office of China on August 18, 2023, with application number 202311050409.X and application name “A single-servo layer and multi-recording layer optical disc drive, storage device and electronic device”, the entire contents of which are incorporated by reference in this application.

Technical Field

The present invention relates to the field of optical disc technology, and in particular to an optical disc drive, a memory and an electronic device with a single servo layer and multiple recording layers.

Background Art

An optical drive is a device used to read and write optical discs. An optical drive is usually an optional component of a computer or other electronic device, used to read and write various types of optical discs, such as compact discs (CDs), digital versatile discs (DVDs), and blu-ray discs (BDs). The working principle of an optical drive is to use a laser beam to read and write on the surface of an optical disc. When the optical drive reads the disc, the light reflected back by the laser beam is detected by the sensor and then converted into a digital signal to extract the data on the disc. At the same time, the optical drive can also write data to the disc by adjusting the intensity and focus of the laser beam.

When a CD-ROM drive in the related art writes data on a single-servo-layer multi-recording-layer CD-ROM, the red laser uses a pre-pressed single-layer guide layer for servo, and the coaxial blue laser changes the focal depth to record on the multi-layer recording layer. During the installation and use of the CD-ROM drive, the directions of the red and blue laser light sources may change, which may cause the red and blue laser light sources to be non-coaxial, affecting the quality of the CD-ROM drive writing and reading data.

Summary of the invention

In order to solve the above problems, the present application provides a single-servo-layer multi-recording-layer optical disc drive in an embodiment, wherein the internal dichroic mirror is movably fixed inside the optical disc drive to adjust the relative position between the guide light beam and the recording light beam, thereby eliminating the error generated during the installation and use of the optical disc drive. In addition, the present application also provides a memory and an electronic device corresponding to the single-servo-layer multi-recording-layer optical disc drive.

To this end, the following technical solutions are adopted in the embodiments of the present application:

In a first aspect, an embodiment of the present application provides a single-servo layer and multi-recording layer optical disc drive, comprising: a first light source, used to generate a first light beam, to read and write data in the recording layer; a second light source, used to generate a second light beam, to perform focusing and tracking servo in the servo layer; a propagation direction of the second light beam intersects with a propagation direction of the first light beam; a dichroic mirror is arranged at a position where the propagation direction of the second light beam intersects with the propagation direction of the first light beam, for reflecting the first light beam and transmitting the second light beam; a movable component, which movably fixes the dichroic mirror inside the optical disc drive, for changing the orientation of the dichroic mirror to adjust the relative position between the propagation direction of the first light beam and the propagation direction of the second light beam.

In this embodiment, a dichroic mirror is used to transmit and reflect lasers of different wavelengths, and the dichroic mirror can be designed to be movably fixed inside the optical disc drive. The light beam generated by the second light source can be directly transmitted from the dichroic mirror, and the propagation direction will not change with the change of the orientation of the dichroic mirror. After the light beam generated by the first light source is projected onto the surface of the dichroic mirror, reflection is generated. The reflected light beam changes its propagation direction with the change of the orientation of the dichroic mirror. When the propagation direction of the light beam of the first light source projected onto the optical disc is not coaxial with the propagation direction of the light beam of the second light source projected onto the optical disc, the orientation of the dichroic mirror can be changed by changing the movable component to adjust the propagation direction of the light beam of the first light source projected onto the optical disc. The optical disc drive has the advantages of small changes in the internal structure, simple implementation process, high control accuracy, etc., and can realize the precise servo of the light beam of the second light source on the servo layer at a relatively low cost, while the light beam of the first light source is projected onto the center of the data track of each recording layer of the optical disc.

In one embodiment, the movable component includes at least one piezoelectric effect actuator, one end of the at least one piezoelectric effect actuator is fixed at different positions of the dichroic mirror, and the other end of the at least one piezoelectric effect actuator is fixed at different positions inside the optical disc drive; the at least one piezoelectric effect actuator is used to change the orientation of the dichroic mirror when receiving an electrical signal.

In this embodiment, the piezoelectric effect driver is a very common device, which has the advantages of low price, convenient control, and precise control, etc. After the dichroic mirror is fixed inside the optical disk drive through the piezoelectric effect driver, if the position of the dichroic mirror is changed, it is only necessary to change the electrical signal flowing into each piezoelectric effect driver to change the position of the dichroic mirror. The whole process is very simple and the control cost is relatively low.

In one embodiment, the dichroic mirror includes a frame, the frame includes two frame structures, one side of the two frame structures is separated from each other, and the opposite side is connected together; one side of the two frame structures connected to each other is fixed inside the optical disc drive; the movable component includes at least one piezoelectric effect driver, which is arranged on one side of the two frame structures separated from each other. Between, used for changing the orientation of the dichroic mirror when receiving an electrical signal.

In this embodiment, if the frame of the dichroic mirror includes two frame structures, one side of the two frame structures is separated from each other, and the opposite side is connected together, a piezoelectric effect driver can be arranged between the separated sides. If the orientation of the dichroic mirror is changed, the orientation of the dichroic mirror can be changed by only changing the electrical signals flowing into each piezoelectric effect driver, and the whole process is simpler and the control cost is lower.

In one embodiment, it also includes: a controller, which is connected to the piezoelectric effect driver respectively, and is used to detect the deviation degree between the light spot of the first light beam and the light spot of the second light beam, and send an electrical signal of a corresponding value to the piezoelectric effect driver.

In this embodiment, the controller is a central unit that accurately controls the orientation of the dichroic mirror. The controller can change the electrical signal flowing into each piezoelectric effect driver according to the deviation between the light spot of the first light beam and the light spot of the second light beam, thereby accurately changing the orientation of the dichroic mirror to adjust the relative position between the first light beam and the second light beam, ensuring that when the servo layer accurately completes the servo control, the first light beam used for reading and writing the recording layer always remains at the center of the data track, and the deviation caused by the different coaxiality of different driver installation errors can be eliminated.

In one embodiment, it further includes: a first photodetector, which is used to receive the first light beam and convert the focusing deviation signal and/or the tracking deviation signal of the first light beam into an electrical signal of a corresponding numerical value.

In this embodiment, after receiving the first light beam, the first photodetector converts the first light beam into an electrical signal of a corresponding value to detect the light intensity of the first light beam. The light inlet of the photodetector generally has four quadrants, and each quadrant is provided with a photosensitive detector. If there is a focus and tracking deviation, the light intensities received by the four quadrants of the photodetector are different. The photodetector detects the focus and tracking errors through different addition and subtraction operations of the light intensities of the four quadrants.

In one embodiment, it also includes: a first focus servo circuit and a first tracking servo circuit, wherein the first focus servo circuit is used to adjust the focus position of the first light beam according to the change of the electrical signal corresponding to the focus deviation signal of the first photodetector; the first tracking servo circuit is used to adjust the direction of the first light beam according to the change of the electrical signal corresponding to the tracking deviation signal of the first photodetector.

In this embodiment, the first focus servo circuit can make a slight displacement adjustment to the objective lens according to the change of the light intensity signal of the first light beam, so that the focus of the first light beam can reach the optimal position. The first tracking servo circuit can adjust the direction of the objective lens according to the change of the light intensity signal of the first light beam, so that the objective lens can accurately follow the position change of the first light beam, so that the objective lens can maintain the correct pointing direction of the first light beam.

In one embodiment, it also includes: a first polarization beam splitter, which is arranged at a position in the propagation direction of the first light beam, and is used to split the first light beam into two identical sub-beams, and project one sub-beam to the light inlet of the first photodetector, and project the other sub-beam to the dichroic mirror.

In this embodiment, the first polarization beam splitter can split the first light beam into two sub-beams with the same intensity, so that the first polarization beam splitter can detect the intensity of the first light beam projected onto the recording medium.

In one embodiment, it further includes: a second photodetector for receiving the second light beam and converting a focusing deviation signal and/or a tracking deviation signal of the second light beam into an electrical signal of a corresponding value.

In this embodiment, after receiving the second light beam, the second photodetector converts the second light beam into an electrical signal of a corresponding value to detect the light intensity of the second light beam. If there is a focus and tracking deviation, the light intensities received by the four quadrants of the photodetector are different. The photodetector detects the focus and tracking errors through different addition and subtraction operations of the light intensities of the four quadrants.

In one embodiment, it also includes: a second focus servo circuit and a second tracking servo circuit, the second focus servo circuit is used to adjust the focus position of the second light beam according to the change of the electrical signal corresponding to the focus deviation signal of the second photodetector; the second tracking servo circuit is used to adjust the direction of the second light beam according to the change of the electrical signal corresponding to the tracking deviation signal of the second photodetector.

In this embodiment, the second focus servo circuit can make a slight displacement adjustment to the objective lens according to the change of the light intensity signal of the second light beam, so that the focus of the second light beam can reach the optimal position. The second tracking servo circuit can adjust the direction of the objective lens according to the change of the light intensity signal of the second light beam, so that the objective lens can accurately follow the position change of the second light beam, so that the objective lens can maintain the correct pointing direction of the second light beam.

In one embodiment, it also includes: a second polarization beam splitter, which is arranged at a position in the propagation direction of the second light beam, and is used to split the second light beam into two identical sub-beams, and project one sub-beam to the light inlet of the second photodetector, and project the other sub-beam to the dichroic mirror.

In a second aspect, an embodiment of the present application provides a storage device comprising: at least one single-servo layer multi-recording layer optical disc, and at least one optical disc drive that may be implemented as in the embodiments of the first aspect, for reading and writing data on the at least one single-servo layer multi-recording layer optical disc.

In a third aspect, an embodiment of the present application provides an electronic device, comprising: at least one storage device as may be implemented in each embodiment of the second aspect. A device and at least one controller are respectively connected to the at least one memory and are used to control the at least one memory to read and write data.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief introduction to the drawings required for describing the embodiments or prior art.

FIG1 is a schematic diagram showing the principle of an optical disc drive reading and writing on an optical disc with a single servo layer and multiple recording layers;

FIG2 is a schematic structural diagram of an optical disc drive in the related art;

FIG3 is a schematic diagram of the structure of an optical disc drive provided in an embodiment of the present application;

FIG4( a ) is a schematic diagram of a blue laser beam 1 and a red laser beam 1 provided in an embodiment of the present application coaxially propagating on a dichroic mirror;

FIG4( b ) is a schematic diagram of a blue laser beam 1 and a red laser beam 1 propagating incoaxially on a dichroic mirror provided in an embodiment of the present application;

FIG4( c ) is a schematic diagram of another blue laser beam 1 and a red laser beam 1 propagating incoaxially on a dichroic mirror provided in an embodiment of the present application;

FIG5 is a schematic diagram of deformation of a deformation block of a piezoelectric effect actuator provided in an embodiment of the present application when receiving different electrical signals;

FIG6 is a schematic diagram of an assembly between a movable component and a dichroic mirror provided in an embodiment of the present application;

FIG7 is a schematic diagram of assembly between another movable component and a dichroic mirror provided in an embodiment of the present application;

FIG8( a ) is a schematic diagram of a blue laser beam 1 and a red laser beam 1 provided in an embodiment of the present application, which propagate coaxially in a direction in which a dichroic mirror is in the same position;

FIG8( b ) is a schematic diagram of a blue laser beam 1 and a red laser beam 1 provided in an embodiment of the present application, propagating in different axes when a dichroic mirror is in the same position;

FIG8( c ) is a schematic diagram of the blue laser beam 1 and the red laser beam 1 provided in an embodiment of the present application propagating in different axes when the dichroic mirror is in another orientation.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

The term "and/or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol "/" in this article indicates that the associated objects are in an or relationship, for example, A/B means A or B.

The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of the objects. For example, a first response message and a second response message are used to distinguish different response messages rather than to describe a specific order of the response messages.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two. For example, multiple processing units refer to two or more processing units, etc.; multiple elements refer to two or more elements, etc.

A single-servo-layer multi-recording-layer optical disc is an optical disc structure that has the ability to store multiple layers of data on a single side. The optical disc drive utilizes the transparency between different data layers of a single-servo-layer multi-recording-layer optical disc. By adjusting the focus of the laser beam and selecting the appropriate data layer, it can read and write multiple data layers of a single-servo-layer multi-recording-layer optical disc. The optical disc drive allows the read/write head to select a specific data layer for operation by switching the focus position of the laser beam or adjusting the wavelength of the laser.

FIG1 is a schematic diagram showing the principle of an optical disc drive reading and writing on a single-servo-layer multi-recording-layer optical disc. As shown in FIG1 , a red laser as a guide beam passes through an objective lens and multiple recording layers of a single-servo-layer multi-recording-layer optical disc, and is projected onto the guide layer of the single-servo-layer multi-recording-layer optical disc. The red laser uses the concave-convex, indentations or marks of the guide layer to perform servo operations, which can realize the functions of accurately positioning and tracking the target in optical devices. A blue laser as a recording beam passes through an objective lens and is projected onto a specific recording layer of a single-servo-layer multi-recording-layer optical disc. The recording beam is focused on the recording layer and interacts with the recording layer to realize reading and writing data on the recording layer.

When the optical drive reads and writes on a single-servo-layer multi-recording-layer optical disc, the guide beam and the recording beam always remain coaxial, and the guide beam Keeping the paths of the guide beam and the recording beam in the optical system consistent helps to better align and calibrate the beams, ensuring that both beams are precisely focused at the focal point to obtain the best optical performance and recording quality. Coaxial means that the propagation direction of the guide beam is the same as the propagation direction of the recording beam, and the center of the guide beam is at the same position as the center of the recording beam. The guide beam and the recording beam share an optical path, which can reduce the number of components and installation complexity of the optical system to improve the stability and reliability of the optical system.

FIG2 is a schematic diagram of the structure of an optical disc drive in the related art. As shown in FIG2, the red laser emitted by the red laser diode (RLD) is projected onto the guide layer of the optical disc through various lenses. The blue laser emitted by the blue laser diode (BLD) is projected onto the recording medium of the optical disc through various lenses and a relay lens group (relay lens). The optical disc drive can adjust the relay lens group to a set position so that the red laser and the blue laser are coaxial. The coaxial red laser and blue laser can share an actuator to focus and track the objective lens, thereby adjusting the focal depth of the blue laser and operating on different layers of the recording medium.

In the related art, the coaxiality of the red laser and the blue laser depends on the accuracy of the CD-ROM drive assembly and the accuracy of the components inside the CD-ROM drive. After the CD-ROM drive is assembled, the position of the internal dichroic mirror is fixed and cannot be adjusted. When manufacturers produce CD-ROM drives, it is difficult to ensure that all the red lasers and blue lasers of the CD-ROM drives are coaxial, and errors in different directions will always occur. For errors in the focusing direction, the CD-ROM drive can eliminate the errors in the focusing direction by adjusting the relay lens group. For errors in the tracking direction, the CD-ROM drive can eliminate the errors in the tracking direction by adjusting the objective lens and the actuator. However, the red laser and the blue laser share the objective lens and the actuator. If the CD-ROM drive adjusts the objective lens and the actuator based on the blue laser, the red laser will produce errors in the tracking direction, resulting in the CD-ROM drive being unable to simultaneously eliminate the errors of the red laser and the blue laser in the tracking direction.

In order to solve the defects of the optical disc drive in the related art, the embodiments of the present application provide an optical disc drive, a storage device and an electronic device with a single servo layer and multiple recording layers. Usually, there is a dichroic mirror (dichroic prism or dichroic mirror) inside the optical disc drive. The red laser can directly pass through the dichroic mirror and be transmitted to the recording medium of the optical disc. After the blue laser is projected onto the side surface of the dichroic mirror, it is reflected to the recording medium of the optical disc. The dichroic mirror can be fixed inside the optical disc drive by a movable component, such as inside the optical head of the optical disc drive. The movable component can change the orientation of the dichroic mirror to adjust the relative position between the propagation direction of the red laser and the propagation direction of the blue laser, so that the red laser and the blue laser always remain coaxial, thereby eliminating the errors generated during the installation and use of the optical disc drive.

FIG3 is a schematic diagram of the structure of an optical disc drive provided in an embodiment of the present application. As shown in FIG3 , the optical disc drive 300 may include a first light source 301, a second light source 302, a dichroic mirror 303, an active component 304, an anamorphic prism 305, a polarizing beam splitter (PBS) 306, a PBS 307, a photodetector 308, a photodetector 309, a focus servo circuit 310, a tracking servo circuit 311, a focus servo circuit 312, a tracking servo circuit 313, a beam splitter aperture 313, a quarter wave plate 314, and an objective lens 315.

In the embodiment of the present application, the wavelength of the light source emitted by the first light source 301 is different from the wavelength of the light source emitted by the second light source 302. One of the first light source 301 and the second light source 302 serves as a recording light source. The recording light beam generated by the recording light source can be focused on the recording layer and interact with the recording layer to read and write data on the recording layer. The other light source of the first light source 301 and the second light source 302 serves as a guiding light source. The guiding light beam generated by the guiding light source is focused and tracked on the servo layer, which can realize the functions of accurately positioning and tracking the target in the optical device. In the embodiment of the present application, the first light source 301 serves as a recording light source and can emit a blue laser. The second light source 302 serves as a guiding light source and can emit a red laser.

The blue laser can be projected onto the surface of one side of the dichroic mirror 303 through optical devices such as the anamorphic prism 305, the PBS 306, and the convex mirror. The anamorphic prism 305 is a specially designed optical device for changing the aspect ratio of the input light beam to achieve the desired deformation effect of deforming or compressing the light beam. In the embodiment of the present application, after the blue laser passes through the anamorphic prism 305, the light in the optical path is deformed or compressed, so that the blue laser is deformed or compressed to the set deformation effect to meet the requirement of writing data on the recording medium of the optical disc by the blue laser.

PBS is an optical device, generally composed of special optical materials and reflective coatings. PBS can split the input light beam into two mutually perpendicular and equal-intensity beams according to the set polarization direction. In the embodiment of the present application, PBS 306 can split the blue laser into two mutually perpendicular and equal-intensity blue laser sub-beams, and project one blue laser sub-beam 1 onto the surface of one side of the dichroic mirror 303, and project the other blue laser sub-beam 2 onto the light inlet of the photodetector 308.

A photodetector is a device that converts light energy into an electrical signal, and is used to detect and measure the intensity of light. In the embodiment of the present application, after receiving the blue laser sub-beam 2, the photodetector 308 converts the blue laser sub-beam 2 into an electrical signal of a corresponding value to detect the light intensity of the blue laser sub-beam 2. After the photodetector 308 detects the light intensity of the blue laser sub-beam 2, the position and direction of the optical path can be adjusted according to the light intensity signal.

The photodetector 308 can be connected to a focus servo circuit 310 and a tracking servo circuit 311. The photodetector 308 can generate a control signal based on the light intensity signal of the blue laser sub-beam 2, and send it to the focus servo circuit 310 and the tracking servo circuit 311 to control the movement of the optical device to adjust the phase position and relative direction of the blue laser sub-beam 1 projected onto the optical disc. In the embodiment of the present application, the light inlet of the photodetector generally has four quadrants, and each quadrant is provided with a photosensitive detector. If the blue laser sub-beam 2 is projected There is a focus deviation and a tracking deviation in the input port of the photodetector 308, and the light intensities received by the four quadrants of the photodetector 308 are different. The photodetector 308 can detect the focus deviation and the tracking deviation of the blue laser sub-beam 2 by different addition and subtraction operations of the light intensities of the four quadrants. The photodetector 308 can convert the focus deviation signal into an electrical signal of a corresponding value and send it to the focus servo circuit 310, and convert the tracking deviation signal into an electrical signal of a corresponding value and send it to the tracking servo circuit 311.

The focus servo circuit 310 can adjust the focus position of the optical path by controlling the position of optical devices (such as the objective lens 315, the dichroic aperture 313, the quarter wave plate 314, etc.). In the embodiment of the present application, the focus servo circuit 310 can be connected to the objective lens 315. After receiving the electrical signal corresponding to the focus deviation signal of the photodetector 308, the focus servo circuit 310 can allow the servo system to make a slight displacement adjustment to the objective lens 315 according to the change of the electrical signal corresponding to the focus deviation signal of the photodetector 308, so that the focus of the blue laser sub-beam 1 can reach the optimal position.

The tracking servo circuit 311 can track the position of the light source or the moving target by controlling the direction of the optical device (such as the objective lens 315, the aperture 313 of the beam splitter, the 1/4 wave plate 314, etc.). In the embodiment of the present application, the tracking servo circuit 311 can be connected to the objective lens 315. After receiving the electrical signal corresponding to the tracking deviation signal of the photodetector 308, the tracking servo circuit 311 can adjust the direction of the objective lens 315 according to the change of the electrical signal corresponding to the tracking deviation signal of the photodetector 308, so that the objective lens 315 can accurately follow the position change of the blue laser sub-beam 1, so that the objective lens 315 can maintain the correct pointing direction of the blue laser sub-beam 1.

The red laser can pass through optical devices such as PBS 307 and convex mirrors and be projected onto the dichroic mirror 303. PBS 307 can split the red laser into two mutually perpendicular red laser sub-beams with the same intensity, and project one red laser sub-beam 1 onto the dichroic mirror 303, and project the other red laser sub-beam 2 onto the light inlet of the photodetector 309. After receiving the red laser sub-beam 2, the photodetector 309 converts the red laser sub-beam 2 into an electrical signal of a corresponding value to detect the light intensity of the red laser sub-beam 2. After detecting the light intensity of the red laser sub-beam 2, the photodetector 309 can adjust the direction of the optical path according to the light intensity signal.

The photodetector 309 can be electrically connected to the focus servo circuit 312 and the tracking servo circuit 313. The photodetector 309 can detect the light intensity signal of the red laser sub-beam 2 according to the light intensity of the red laser sub-beam 2 projected to the four quadrants, and generate a control signal. The photodetector 309 sends the control signal to the focus servo circuit 312 and the tracking servo circuit 313 to control the movement of the optical device to adjust the phase position and relative direction of the red laser sub-beam 1 projected to the optical disc.

In the embodiment of the present application, the focus servo circuit 312 may be connected to the objective lens 315. After receiving the electrical signal corresponding to the focus deviation signal of the photodetector 309, the focus servo circuit 312 may allow the servo system to perform a slight displacement adjustment on the objective lens 315 according to the change of the electrical signal corresponding to the focus deviation signal of the photodetector 309, so that the focus of the red laser sub-beam 1 can reach the optimal position.

After receiving the electrical signal corresponding to the tracking deviation signal of the photodetector 309, the tracking servo circuit 313 can allow the servo system to adjust the direction of the objective lens 315 according to the change of the electrical signal corresponding to the tracking deviation signal of the photodetector 309, so that the objective lens 315 can accurately follow the position change of the red laser sub-beam 1, thereby enabling the objective lens 315 to maintain the correct pointing direction of the red laser sub-beam 1.

The dichroic mirror 303 is an optical device, also known as a polarizing filter or a birefringent filter. The dichroic mirror 303 utilizes the birefringence property of the material to selectively transmit or block light in a specific direction through different refractive indices (or refractive indices). That is, the dichroic mirror 303 is an optical device that allows a light beam of a set wavelength to be transmitted and light beams of other wavelengths to be reflected. In the embodiment of the present application, the dichroic mirror 303 allows a red laser with a longer wavelength to be transmitted and a blue laser with a shorter wavelength to be reflected. That is, after the red laser is projected onto the surface of the dichroic mirror 303, it will directly pass through the dichroic mirror 303. After the blue laser is projected onto the surface of the dichroic mirror 303, it will be reflected, changing the direction of the blue laser. The propagation direction of the red laser projected by the dichroic mirror 303 is coaxial with the propagation direction of the reflected blue laser, and is projected onto the optical disc through optical devices such as the beam splitting diode aperture 313, the 1/4 wave plate 314, and the objective lens 315.

The beam splitter aperture is an optical device, generally composed of a series of color separation filters and apertures. The filters of the beam splitter aperture have specific optical properties, which only allow light within a specific wavelength range to pass through, while reflecting or absorbing light of other wavelengths and controlling it through the aperture. In the embodiment of the present application, the coaxial red laser and blue laser pass through the beam splitter aperture 313 to separate the different wavelength components in the incident light beam to improve the purity of the two lasers.

A quarter wave plate is an optical device used to change the polarization state of an incident light beam. A quarter wave plate is a wave plate made of a special material, and its thickness is about one quarter of the wavelength of light. In the embodiment of the present application, after the coaxial red laser and the blue laser pass through the quarter wave plate 314, the quarter wave plate 314 can convert the linear polarization of light in one direction into circular polarization in another direction, or convert the circular polarization of light in one direction into linear polarization, thereby adjusting and changing the polarization state of the coaxial red laser and the blue laser.

The objective lens is an optical device used to gather and project light. In the embodiment of the present application, after the coaxial red laser and blue laser pass through the objective lens 315, the objective lens 315 accurately focuses the coaxial red laser and blue laser onto the data track on the surface of the optical disc and maintains accurate reading or writing of data. The objective lens 315 provides accurate and stable optical performance for the optical disc drive through functions such as focusing, tracking, and spot shape control.

The dichroic mirror 303 is movably disposed at a position where the propagation direction of the red laser sub-beam 1 intersects the propagation direction of the blue laser sub-beam 1. In the embodiment of the present application, the propagation direction of the red laser beam 1 is perpendicular to the plane of the optical disc. When the dichroic mirror 303 is disposed between the second light source 302 and the optical disc, the propagation direction of the red laser beam 1 does not change with the position and angle of the dichroic mirror 303.

When the propagation direction of the blue laser beam 1 is different from the propagation direction of the red laser beam 1, after the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, it is reflected on the surface of the dichroic mirror 300, thereby changing the propagation direction of the blue laser beam 1. The propagation direction of the blue laser beam 1 after reflection is coaxial with the propagation direction of the red laser beam 1.

In one possible embodiment, as shown in FIG4(a), the propagation direction of the blue laser beam 1 is perpendicular to the propagation direction of the red laser beam 1. The angle between the surface of the dichroic mirror 303 and the propagation direction of the red laser beam 1 is 45°. After the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, it will be reflected on the surface of the dichroic mirror 303. The propagation direction of the reflected blue laser beam 1 is consistent with the propagation direction of the transmitted red laser beam 1, achieving the effect of the two beams being coaxial.

It should be noted that the propagation direction of the reflected blue laser beam 1 in FIG4(a) is not coaxial with the propagation direction of the transmitted red laser beam 1. This is to facilitate readers to see the two beams. In essence, the propagation direction of the reflected blue laser beam 1 coincides with the propagation direction of the transmitted red laser beam 1.

As shown in FIG4(b), when the angle between the propagation direction of the blue laser beam 1 and the propagation direction of the red laser beam 1 is greater than 90°, after the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, the propagation direction of the reflected blue laser beam 1 is inconsistent with the propagation direction of the transmitted red laser beam 1. The propagation direction of the reflected blue laser beam 1 is below the propagation direction of the transmitted red laser beam 1.

In order to make the propagation direction of the reflected blue laser beam 1 coaxial with the propagation direction of the transmitted red laser beam 1, the orientation of the dichroic mirror 303 can be adjusted to change the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1, so as to adjust the relative position between the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1, so as to achieve that the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1 remain coaxial. In the embodiment of the present application, the dichroic mirror 303 can be slightly tilted forward inside the optical disc drive 300 to change the angle between its surface and the propagation direction of the blue laser beam 1, so that the angle at which the blue laser beam 1 is incident on the surface of the dichroic mirror 303 is 45°. After the reflection angle of the blue laser beam 1 is reduced, the propagation direction of the reflected blue laser beam 1 is coaxial with the propagation direction of the transmitted red laser beam 1.

As shown in FIG4(c), when the angle between the propagation direction of the blue laser beam 1 and the propagation direction of the red laser beam 1 is less than 90°, after the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, the propagation direction of the reflected blue laser beam 1 is inconsistent with the propagation direction of the transmitted red laser beam 1. The propagation direction of the reflected blue laser beam 1 is above the propagation direction of the transmitted red laser beam 1.

In order to make the propagation direction of the reflected blue laser beam 1 coaxial with the propagation direction of the transmitted red laser beam 1, the orientation of the dichroic mirror 303 can be adjusted to change the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1, so as to adjust the relative position between the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1, so as to achieve that the propagation direction of the reflected blue laser beam 1 is coaxial with the propagation direction of the transmitted red laser beam 1. In the embodiment of the present application, the dichroic mirror 303 can be slightly tilted backward inside the optical disc drive 300 to change the angle between its surface and the propagation direction of the blue laser beam 1, so that the angle of the blue laser beam 1 incident on the surface of the dichroic mirror 303 is 45°. After the reflection angle of the blue laser beam 1 is increased, the propagation direction of the reflected blue laser beam 1 is coaxial with the propagation direction of the transmitted red laser beam 1.

The movable component 304 movably fixes the dichroic mirror 303 inside the optical disc drive 300. The movable component 304 can fix the position of the dichroic mirror 303, and can prevent the dichroic mirror 303 from moving inside the optical disc drive 300, which affects the reliability of the product. The movable component 304 can change the orientation of the dichroic mirror 303 to adjust the relative position between the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1, so that the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1 remain coaxial.

The movable component 304 may be a piezoelectric effect actuator. A piezoelectric effect actuator is a device that uses the piezoelectric effect to control or drive a device. The piezoelectric effect refers to the change in charge distribution of certain crystals or ceramic materials when subjected to pressure or pressure, thereby generating an electric field or potential difference. A piezoelectric effect actuator uses the piezoelectric effect to control or drive a corresponding device by applying pressure or pressure.

As shown in FIG5 , the piezoelectric effect driver may include a deformation block. The deformation block may be lead barium zirconate titanate (PZT). The two ends of the deformation block are electrically connected to the positive and negative electrodes of the power supply, respectively. When the power supply does not apply an electrical signal to the two ends of the deformation block, the deformation block does not deform. When the power supply applies an electrical signal to the two ends of the deformation block, the deformation block will deform and become a deformation block with a larger radius and a smaller axial length. Among them, within a reasonable range, the greater the electrical signal applied by the power supply, the greater the deformation of the deformation block. That is, the larger the radius of the deformation block, the shorter the axial length.

FIG6 is a schematic diagram of an assembly between a movable component and a dichroic mirror provided in an embodiment of the present application. As shown in FIG6 , the movable component 304 includes four piezoelectric effect actuators. One end of the four piezoelectric effect actuators is respectively fixed to the four corners of the frame of the dichroic mirror 303. The other ends of the four piezoelectric effect actuators are respectively fixed to the inner surface of the housing of the optical disk drive 300 or the surface of other devices. The controller can apply electric signals of different magnitudes to the four piezoelectric effect drivers to arbitrarily change the orientation of the dichroic mirror 303. Optionally, the number of piezoelectric effect drivers included in the movable assembly 304 is not limited to the four shown in FIG6 , but can also be other numbers. The position where the piezoelectric effect driver is installed is not limited to the position shown in FIG6 , but can also be other positions.

For example, when the dichroic mirror 303 needs to be tilted to the left side (the left side shown in FIG. 6 ) by a certain angle, the controller applies the same electrical signal to the upper left piezoelectric effect driver and the lower left piezoelectric effect driver, and does not need to apply the electrical signal to the upper right piezoelectric effect driver and the lower right piezoelectric effect driver. Alternatively, the controller applies the same electrical signal to the upper left piezoelectric effect driver and the lower left piezoelectric effect driver, which is greater than the same electrical signal to the upper right piezoelectric effect driver and the lower right piezoelectric effect driver.

For another example, when the dichroic mirror 303 needs to be tilted to the lower left side by a certain angle, the controller applies an electric signal to the piezoelectric effect driver at the lower left side, and does not need to apply an electric signal to the piezoelectric effect driver at the upper left side, the piezoelectric effect driver at the upper right side, and the piezoelectric effect driver at the lower right side. Alternatively, the controller applies an electric signal of the same magnitude to the piezoelectric effect driver at the upper left side and the piezoelectric effect driver at the lower right side, and the electric signal is smaller than the electric signal applied to the piezoelectric effect driver at the lower left side. Alternatively, the controller applies an electric signal to the piezoelectric effect driver at the upper right side, and the electric signal is smaller than the electric signal applied to the piezoelectric effect driver at the upper left side and the piezoelectric effect driver at the lower right side.

Fig. 7 is a schematic diagram of assembly between another movable component and a dichroic mirror provided in an embodiment of the present application. As shown in Fig. 7, the dichroic mirror 303 includes a frame. The frame is composed of two frame structures. One side of the two frame structures is separated from each other, and the opposite side is connected together. The dichroic mirror 303 is embedded in a frame structure. The movable component 304 includes two piezoelectric effect drivers. The two piezoelectric effect drivers are respectively arranged at the two ends of a side of the two frame structures that are separated from each other, and are fixed to the sides of the two frame structures that are close to each other. The two piezoelectric effect drivers are electrically connected to the controller independently. The controller can apply electrical signals of different sizes to the two piezoelectric effect drivers to arbitrarily change the orientation of the dichroic mirror 303. Optionally, the number of piezoelectric effect drivers included in the movable component 304 is not limited to the two shown in Fig. 7, but can also be other numbers. The position where the piezoelectric effect driver is installed is not limited to the position shown in Fig. 7, but can also be other positions.

Under normal circumstances, the two piezoelectric effect actuators are arranged between one side of the two frame structures to spread one side of the two frame structures apart. When the axial length of the piezoelectric effect actuator becomes shorter, the two frame structures move one side of the two frame structures closer to each other under the action of the restoring force.

As shown in FIG8(a), after one side of the frame of the dichroic mirror 303 is fixed to a set position inside the optical disc drive 300, the two frame structures of the frame are in a normal state. That is, one side of the two frame structures are spread apart from each other. After the red laser beam 1 is projected onto the dichroic mirror 303, it is directly transmitted from the dichroic mirror 303, and the propagation direction remains unchanged. After the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, it will be reflected on the surface of the dichroic mirror 303, changing the propagation direction. At this time, the propagation direction of the reflected blue laser beam 1 is consistent with the propagation direction of the transmitted red laser beam 1, achieving the effect of the two beams being coaxial.

As shown in FIG8(b), when the propagation direction of the blue laser beam 1 changes, after the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, the propagation direction of the reflected blue laser beam 1 is inconsistent with the propagation direction of the transmitted red laser beam 1. The propagation direction of the reflected blue laser beam 1 is on the left side of the propagation direction of the transmitted red laser beam 1.

In order to make the propagation direction of the reflected blue laser beam 1 coaxial with the propagation direction of the transmitted red laser beam 1, the orientation of the dichroic mirror 303 can be adjusted to change the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1, so as to adjust the relative position between the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1, so as to achieve that the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1 remain coaxial. In the embodiment of the present application, the controller can reduce the electrical signal applied to the piezoelectric effect driver between the two frame structures. After the electrical signals at both ends of the piezoelectric effect driver are reduced, the axial length becomes longer, and the distance between one side of the two frame structures is increased. Under the action of the restoring force of the piezoelectric effect driver, the frame structure with the dichroic mirror 303 installed in the two frame structures moves slightly upward to reduce the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1. After the reflection angle of the blue laser sub-beam 1 is increased, the propagation direction of the reflected blue laser sub-beam 1 is coaxial with the propagation direction of the transmitted red laser sub-beam 1 .

As shown in FIG8(c), when the propagation direction of the blue laser beam 1 changes, after the blue laser beam 1 is projected onto the surface of the dichroic mirror 303, the propagation direction of the reflected blue laser beam 1 is inconsistent with the propagation direction of the transmitted red laser beam 1. The propagation direction of the reflected blue laser beam 1 is to the right of the propagation direction of the transmitted red laser beam 1.

In order to make the propagation direction of the reflected blue laser beam 1 coaxial with the propagation direction of the transmitted red laser beam 1, the orientation of the dichroic mirror 303 can be adjusted to change the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1, so as to adjust the relative position between the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1, so as to achieve that the propagation direction of the reflected blue laser beam 1 and the propagation direction of the transmitted red laser beam 1 remain coaxial. In the embodiment of the present application, the controller can increase the electrical signal applied to the piezoelectric effect driver between the two frame structures. After the electrical signals at both ends of the piezoelectric effect driver are increased, the axial length becomes shorter, and the distance between the two side edges of the frame structures is reduced. Under the action of the restoring force, the two frame structures move toward The dichroic mirror 303 is slightly moved downward to increase the angle between the surface of the dichroic mirror 303 and the propagation direction of the blue laser beam 1. After the reflection angle of the blue laser beam 1 is reduced, the propagation direction of the reflected blue laser beam 1 is coaxial with the propagation direction of the transmitted red laser beam 1.

In the embodiment of the present application, the electrical signal applied by the controller to the piezoelectric effect driver is related to the degree to which the spot of the blue laser beam 1 deviates from the track of recorded data. This relationship can be studied and determined through experiments. Generally speaking, the greater the degree to which the spot of the blue laser beam 1 deviates from the track of recorded data, the greater the electrical signal applied by the controller to the piezoelectric effect driver. The smaller the degree to which the spot of the blue laser beam 1 deviates from the track of recorded data, the smaller the electrical signal applied by the controller to the piezoelectric effect driver.

The controller can use a push-pull method to detect the deviation of the light spot of the blue laser beam 1 from the recorded data track. The basic principle of the push-pull method is to apply an alternating voltage to the piezoelectric material to cause it to generate mechanical vibration. This vibration can cause a slight change in the light propagation path, thereby causing the deviation of the light spot. By adjusting the frequency and amplitude of the applied voltage, the degree of deviation of the light spot can be controlled. After the controller determines that the light spot of the blue laser beam 1 deviates from the center of the data track, the four-quadrant photosensitive detector will detect the degree of deviation. The low-pass filter filters out the high-frequency response and noise in the results output by the photosensitive detectors of the four quadrants, and the low-frequency part of the output is the fixed deviation between the propagation direction of the blue laser beam 1 and the propagation direction of the red laser beam 1. After the controller converts the fixed deviation into an electrical signal of a corresponding value, it is input into the piezoelectric effect driver to adjust the orientation of the dichroic mirror 303 so that the propagation direction of the blue laser beam 1 and the propagation direction of the red laser beam 1 always remain coaxial.

In the embodiment of the present application, the dichroic mirror 303 is used to transmit and reflect lasers of different wavelengths, and the dichroic mirror 303 can be designed to be movably fixed inside the optical disc drive 300. The light beam generated by the second light source 302 can be directly transmitted from the dichroic mirror 303, and the propagation direction will not change with the change of the orientation of the dichroic mirror 303. After the light beam generated by the first light source 301 is projected onto the surface of the dichroic mirror 303, reflection is generated. The reflected light beam changes the propagation direction with the change of the orientation of the dichroic mirror 303. When the propagation direction of the light beam of the first light source 301 projected onto the optical disc is not coaxial with the propagation direction of the light beam of the second light source 302 projected onto the optical disc, the orientation of the dichroic mirror 303 can be changed to adjust the relative position between the propagation direction of the light beam of the first light source 301 and the propagation direction of the light beam of the second light source 302, so as to achieve that the propagation direction of the light beam of the first light source 301 and the propagation direction of the light beam of the second light source 302 remain coaxial. The optical disc drive 300 protected by the present application has the advantages of small internal structure changes, simple implementation process, and high control accuracy. When the light beam of the second light source 302 is accurately served in the servo layer at a relatively low cost, the light beam of the first light source 301 is projected to the center of the data track of each recording layer of the optical disc.

An embodiment of the present application provides a memory, which includes an optical drive and an optical disc, and the optical drive can read and write data to the optical disc. Among them, the optical drive can be a single-servo layer multi-recording layer optical drive as shown in Figures 3 to 8(c). The optical disc can be an optical disc or other types of single-servo layer multi-recording layer optical discs. Since the memory includes the optical drive, the memory has all or at least some of the advantages of the optical disc drive. The memory can be a CD, DVD, BD, etc. The memory can be a dedicated optical disc type, such as an optical disc image file, an optical disc mirror file, etc. The memory can be a storage medium based on optical technology, such as an optical memory (optical memory) and an optical disc array (optical disc array), etc.

The number of components and types of components in the memory provided by the embodiments of the present application are not limited to the above embodiments, and all technical solutions implemented under the principles of the present application are within the protection scope of the present solution. Any one or more embodiments or diagrams in the specification, combined in an appropriate manner, are within the protection scope of the present solution.

An embodiment of the present application provides an electronic device, which includes at least one memory. The memory includes an optical disk drive as shown in Figures 3 to 8(c). Since the electronic device includes the optical disk drive, the electronic device has all or at least some of the advantages of the optical disk drive. The electronic device may be a desktop computer, a server, a portable notebook computer, etc.

The number of components and types of components in the electronic device provided by the embodiments of the present application are not limited to the above embodiments, and all technical solutions implemented under the principles of the present application are within the protection scope of the present solution. Any one or more embodiments or diagrams in the specification, combined in an appropriate manner, are within the protection scope of the present solution.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application. Those skilled in the art should understand that, although the present application is described in detail with reference to the aforementioned embodiments, the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims (12)

A single-servo-layer multi-recording-layer optical disc drive, characterized by comprising: A first light source (301) is used to generate a first light beam to read and write data on the recording layer; A second light source (302) is used to generate a second light beam for performing focusing and tracking servo on the servo layer; the propagation direction of the second light beam intersects with the propagation direction of the first light beam; A dichroic mirror (303) is arranged at a position where the propagation direction of the second light beam intersects with the propagation direction of the first light beam, and is used to reflect the first light beam and transmit the second light beam; A movable component (304) movably fixes the dichroic mirror inside the optical disc drive and is used to change the orientation of the dichroic mirror to adjust the relative position between the propagation direction of the first light beam and the propagation direction of the second light beam. The optical disc drive according to claim 1, characterized in that the movable component comprises at least one piezoelectric effect actuator, one end of the at least one piezoelectric effect actuator is respectively fixed to different positions of the dichroic mirror, and the other end of the at least one piezoelectric effect actuator is respectively fixed to different positions inside the optical disc drive; The at least one piezoelectric effect actuator is respectively used to change the orientation of the dichroic mirror when receiving an electrical signal. The optical disc drive according to claim 1, characterized in that the dichroic mirror comprises a frame, the frame comprises two frame structures, one side of the two frame structures are separated from each other, and one opposite side is connected together; one side of the two frame structures connected to each other is fixed inside the optical disc drive; The movable component includes at least one piezoelectric effect driver, which is arranged between two mutually separated sides of the two frame structures and is used to change the orientation of the dichroic mirror when receiving an electrical signal. The optical disc drive according to claim 2 or 3, further comprising: The controller is connected to the piezoelectric effect driver respectively, and is used to detect the deviation value between the light spot of the first light beam and the light spot of the second light beam, and send an electrical signal of a corresponding value to the piezoelectric effect driver. The optical disc drive according to any one of claims 1-4 is characterized in that it also includes: a first photodetector (308) for receiving the first light beam and converting a focusing error signal and/or a tracking error signal of the first light beam into an electrical signal of a corresponding numerical value. The optical disc drive according to claim 5, further comprising: a first focus servo circuit (310) and a first tracking servo circuit (311), The first focus servo circuit is used to adjust the focus position of the first light beam according to the change of the electrical signal corresponding to the focus deviation signal of the first photodetector; The first tracking servo circuit is used to adjust the direction of the first light beam according to the change of the electrical signal corresponding to the tracking deviation signal of the first photodetector. The optical disc drive according to claim 5 or 6 is characterized in that it also includes: a first polarization beam splitter (306), which is arranged at a position in the propagation direction of the first light beam, and is used to split the first light beam into two identical sub-beams, and project one sub-beam to the light inlet of the first photodetector, and project the other sub-beam to the dichroic mirror. The optical disc drive according to any one of claims 1-7 is characterized in that it also includes: a second photodetector (309) for receiving the second light beam and converting the focusing deviation signal and/or the tracking deviation signal of the second light beam into an electrical signal of a corresponding numerical value. The optical disc drive according to claim 8, further comprising: a second focus servo circuit (312) and a second tracking servo circuit (313), The second focus servo circuit is used to adjust the focus position of the second light beam according to the change of the electrical signal corresponding to the focus deviation signal of the second photodetector; The second tracking servo circuit is used to adjust the direction of the second light beam according to the change of the electrical signal corresponding to the tracking deviation signal of the second photodetector. The optical disc drive according to claim 8 or 9 is characterized in that it also includes: a second polarization beam splitter (307), which is arranged at a position in the propagation direction of the second light beam, and is used to split the second light beam into two identical sub-beams, and project one sub-beam to the light inlet of the second photodetector, and project the other sub-beam to the dichroic mirror. A memory, comprising: At least one single servo layer multi-recording layer optical disc, At least one optical disc drive as claimed in any one of claims 1 to 10, used to read and write data on the at least one single-servo-layer multi-recording-layer optical disc. An electronic device, comprising: at least one memory as claimed in claim 11, At least one controller is respectively connected to the at least one memory and is used to control the at least one memory to read and write data.