TW379320B - Dual-focus optical read/write system for track tolerance detection by push-pull - Google Patents

Abstract

The invention relates to a kind of dual-focus optical read/write system for track tolerance detection by push-pull, including a light source projected through a solid stuffing lens for generation of 2 light dots one light dot being provided for reading and writing data and the other light dot for tracking tolerance signals. One side of the system disk being engraved with grooved channels in continuation or concentric manner and coated on its entire side reflective membrane for the detection of tracing tolerance signals and the other side covered with optical recording materials for reading and writing data.

Description

Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (1) Field of the invention: The present invention relates to a dual-focus optical read-write system using push-pull method for tracking error detection. The total data storage capacity of the disc & does not require an optical read-write system that operates in conjunction with a high-speed motor. Related prior art: The optical information reading and writing system has a priority to generate a light spot with a small diameter. The smaller the light spot is, the smaller the stem, the larger the capacity of the information stored on the disc. The diameter of the spot is inversely proportional to the number of apertures (NA) of the focused beam, that is, NA = nsin0, where η is the refractive index of the medium at the point where the spot is formed, and 0 is the angle between the edge light and the optical axis in the focused beam. The conventional near-field optical read-write head structure includes a read-write head 11, a plano-convex lens 12, and a disc 13 as shown in the first figure. The convergent light beam output from the read / write head 11 is incident from the lower surface of the convex lens 12 and restricted to propagate within the convex lens 12, so that a large NA can be created at the upper surface of the convex lens 12, and a small diameter is obtained. Light spot (light spot A). In optics, the lens with this function is called Solid Immersion Lens (SIL). With proper design, NA = n sin (9 | = n (n sin 0) = n2 sin 0, where Θ is the beam convergence angle output by the read / write head 11. When the disc 13 is close to the convex lens 12, because Near-field optical effect, part of the light wave will pass through the air gap (thickness about 0.15 / im) between the convex lens 12 and the disc 13, and a light spot (light point) with the same diameter as the light spot A will be formed on the lower surface of the disc 13 B). The physical properties (intensity or polarization vector) of the reflected light reflected by light point B is affected by the information stored at that point. From point B, the near-field optical effect occurs again and passes through the air gap in the opposite direction. , Οϋπ »Ι * Μ · Κ ΙΊΙοηΙ 11 3 This paper size applies to China National Standard (CNS) A4 (21 OX297 mm) (Please read the precautions on the back before filling out this page) Order ---- -〇-—Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (2) Return to the convex lens 12 and the read-write head U. The read-write head η can detect the physical properties of the reflected light and can determine Information on disc 13. The disc used in the conventional near-field optical read-write system is shown in the second figure. There are two discs with a flat (trackless groove) surface. One is the lower surface 131; the other is the upper surface 132. The lower surface 131 is very close to the solid-state condensing lens 133, and the optical recording material film is plated thereon. The light spot β falls on this film, and the upper surface 132 is useless. The tracking error detection method used in the conventional near-field optical read-write system is the Sample Servo (SS) method. According to the sample servo method, It is divided into several virtual sectors in each virtual circle of the track, and a tracking signal sampling pit 134 is pre-engraved at the beginning of each sector. During operation, the light spot hits the pit 134 and then reflects the reflected light. The intensity is a function of the amount of deflection of the light spot. By detecting this light, the amount of deflection error of the light spot can be determined. The detected deflection error photocurrent is sent to the read / write head servo mechanism to correct the deflection of the objective lens. However, the sampling servo method has the following two disadvantages. The first disadvantage is that it must be operated with a high-speed motor. It is assumed that the derailment behavior is constantly occurring at a frequency of 2 kHz. In order to correct it immediately, we must try to produce Frequency is 2kHz off-track error photocurrent signal waveform. In order to generate this waveform, the frequency of sampling pits of the tracking signal must be at least 4kHz. For example, suppose that one circle of the track contains fifty sectors and the motor speed is frps F x 50 = 4 kHz, so f = 80 rps = 4800 rpm, which means that the speed of the motor is very high. Because the high speed motor is not easy to obtain, it makes it difficult to reduce the cost of the near-field optical read-write head. Another disadvantage is ...

CiMJmU'PK 16-Joc 4 This paper size applies to Chinese National Standard (CNS) A4 (210X297 mm) (Please read the precautions on the back before filling this page)

1T A7 ____B7 V. Existence of invention description (3), occupying a part of data storage space, thus reducing the total data storage capacity on the disc. Therefore, the conventional near-field optical read-write head generates a light spot, which illuminates the disc without track grooves but with small sampling pits. The head uses a sampling servo to track the light spot on the disc. The system-wide data storage capacity is low 'and must be operated with high speed horses. The present invention addresses the aforementioned shortcomings by providing an optical read-write system that can increase the total data storage capacity of a disc and eliminates the need for a high-speed motor to cooperate to reduce costs. Summary and purpose of the invention: The present invention relates to an optical read-write system for a push-pull tracking error detection method. In the present invention, two light spots are generated by a light source to illuminate a disc with a track groove. The first light spot is used to provide a near-field optical effect; the second light spot is used to generate diffracted light reflected from the track groove. The tracking error signal is detected by the Push Pull method, so that the system has a higher data storage capacity, and does not need to operate with a high-speed motor. Printed by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economics This invention can be applied to different types of read-write discs, such as "read-only", "dye-type write-once type", "phase change-type write-once type", "Phase change erasure multiple erasure type" and "Magneto-optical erasure multiple erasure type", etc. Schematic description: • In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment of the present invention is given in detail, and the accompanying drawings are described in detail below. Figure 1: A side sectional view of a conventional optical reading and writing system. >

JmlaMiC I'McatSpccilii-atioaVVI l6.Joc 3 This paper is suitable for financial standards (CNS) A4 specifications (2Η) X 297 mm) '' Printed by the Consumers ’Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Invention Description (4 ) Figure 2: A perspective view of the disc of a conventional optical read-write system. Figure 3a: Schematic diagram of the system of the first preferred embodiment of the present invention. Figure 3b: A perspective view of a disc according to the first preferred embodiment of the present invention. Fig. 4a: A schematic diagram of a first preferred embodiment of the present invention when a light beam is reflected from a disc surface including two push-pull pattern areas. Fig. 4b: Schematic diagram of two different push-pull pattern areas included when the light beam is reflected from different disc surface positions in the first preferred embodiment of the present invention. Figure 5: Schematic diagram of the system of the second preferred embodiment of the present invention. Explanation of drawing number: 11 read / write head 12 plano-convex lens 13 disc 131 lower surface 132 upper surface 133 solid-state congestion lens 134 small pit 31 light source 310 photon 311 subtractor 312 condenser 313 photon 314 drive circuit 32. collimator 33 Beamsplitter. 34 Objective lens 35 Solid-state clogging lens 36 Disc 361 Upper surface 362 Lower surface 363 Rail groove 37 Beam splitter 38 Reflector 39 Condenser 51 Light source 511 Subtractor 512 Plane mirror 513 Plane mirror 514 Condenser 515 Condenser 516 Photon 517 Photon 518 Photon 518 Subtractor 52 Collimator lens 53 Beamsplitter 54 Objective lens 55 Solid-state plug lens 56 Disc 561 Upper surface 562 Lower surface 563 Rail groove 57 Beamsplitter

CiVlinUaM'K l * iitonlSpcrHicauon'6)) 6. ≪ ioc This paper size is applicable to China National Standard (CNS) Α4 size (210 ×: 297mm) I; 1 Packing: Thread (please read the precautions on the back first) Fill out this page again) A7 B7 V. Description of the invention (5) Detailed description of the preferred embodiment of the invention: First, please refer to the third a diagram. The light emitted from the laser light source 31 passes through the collimator lens 32 and becomes parallel light. This light is reflected by the beam splitter 33 and then hits the objective lens 34. This light is converged by the objective lens 34 and is incident on the solid state plug lens 35. On the lower surface of the solid congestion lens 35, there are two regions. The first zone ranges from 0 to a diameter and the second zone ranges from a to b, where a < b. The radius of curvature of the surface of the first zone is infinite, while the radius of curvature of the surface of the second zone is r, and Γ is finite. The light emitted from the light source 31 to the first region passes through the solid-state congestion lens 35 after passing through the surface, and then passes through the upper surface of the solid-state congestion lens 35 to form a light point P in the space. The light emitted from the light source 31 to the second region passes through the solid-state congestion lens 35 after acting on its surface, and forms a light spot Q on the upper surface of the solid-state congestion lens 35. A disk 36 having a thickness t and a refractive index η is placed above the upper surface of the solid-state congestion lens 35. The appropriate numbers of t and η are selected so that the upper surface 361 of the disc 36 meets the point P; and the lower surface 362 of the disc 36 is very close to the Q point so that near-field optical effects can occur and make a light point R Appears on the lower surface 362. Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs (please read the notes on the back before filling this page) Please refer to Figures 3b, 4a and 4b. On the upper surface 361 of the disk 36, continuous or concentric circular grooves 363 are formed and plated with a metal reflective film. The gauge and groove depth of the track groove are made to properly match the wavelength and the diameter of the P point, so that the beam reflected from the P point contains two push-pull pattern areas E and F, as shown in the fourth a . The light intensities ′ Ie and if in the two pattern areas change with the off-track distance X of the p point, as shown in the fourth figure b. In addition, the lower surface 362 of the disc 36 is a completely flat surface.

C; 'UnJ «\ i'K I'slent SpeeillcKtien'iil Ιύ doc " J This paper size applies the Chinese National Standard (CNS) M specification (21〇χ 297 mm) Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs Α7 Β7 5. Description of the invention (6) and optical recording material is stored. Please refer to FIG. 3a again. The light emitted from the light source 31 to the first light area is acted on by the surface, passes through the solid-state congestion lens 35, and then passes through the upper surface of the solid-state congestion lens 35 to form a space. The light point P, the reflected light reflected from the point P passes through the disc 36, then the solid-state clogging lens 35, then the objective lens 34, then the beam splitter 33, and then the central air-space beam splitter 37. After reflecting at 38, it passes through the condenser 39 and is finally collected into a recovered light spot and falls on the photon 310. The light receiving surface of the photoreceptor 310 is divided into two photosensitive areas E and F. The photovoltages generated by the two photosensitive areas are VE and VF, respectively. The voltage VE is proportional to IE, and the voltage VF is proportional to Ip. VE and Vf are sent to the subtractor 311 for operation, and a signal output is obtained. Using this output as the tracking error signal TES, TES = Ve-〇 In addition, the lower surface 362 of the disc 36 is a completely flat surface, and a thin film of an optical recording material is plated thereon. 'When data is written, the data signal is serially output to the driving circuit 314 of the laser light source 31, so that the light source 31 generates light intensity corresponding to "1" and "0" of the data as "high intensity" and "medium intensity" alternately Changing output light. As described above, after passing through the elements such as the collimator lens 32, the beam splitter 33, the objective lens 34, and the solid-state clogging lens 35, the light is coated on the lower surface of the disc 36 with the optical recording material film through the near-field optical effect. A light spot R is formed on 362. As the output light intensity of the light source 3 i changes, the light intensity at the R point also changes accordingly. When the R point is "high-intensity", the optical recording material is physically changed by the light and becomes amorphous. This means that the data "1" is written somewhere on the disc; C'JiMU'TK 1 > · ι «ι« · 8 This paper size applies to the Chinese National Standard (CNS) Α4 specification (210X297 mm) J ----- Ί.— 装 ----——-- Order .----- © line ( (Please read the notes on the back before filling this page) A7 B7 V. Description of the invention (7) When the R point is "medium-strength", the optical recording material will be physically changed by the light and become crystalline. Data "0" is written somewhere on the chip. When the data is read, the laser light source is made to emit a constant "low intensity" light. As described above, this light passes through the collimator lens 32, the beam splitter 33, the objective lens 34, and the solid-state condensing lens 35, and then passes through the near-field optical effect on the lower surface 362 of the disc 36 on which data has been written. A light spot R is formed. The intensity of the reflected light reflected from the R point is related to the crystalline nature of the material. The intensity of the reflected light reflected from the "crystalline state j" is strong; the intensity of the reflected light reflected from the "amorphous state" is weak. This light passes through the Q point through the near-field optical effect, then passes through the solid-state clogging lens 35, then passes through the objective lens 34, then passes through the beam splitter 33, then meets the beam splitter 37, and after reflection, passes through the condenser lens 312, and is finally collected into a recovered light. It falls on the photoreceptor 313 and causes the photoreceptor 313 to generate a photovoltage VR. When the reflected light intensity is strong, VR is large; when the reflected light intensity is weak, Vr is small. By detecting the magnitude of Vr, it is known that the reflected light comes from the "crystalline state" or "amorphous state", that is, the data is known as "0" or "1". Therefore, VR is the data read signal RFS. Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs (please read the notes on the back before filling this page). When the data is deleted, make the laser light source emit a constant "medium intensity" light. As described above, this light passes through the collimator lens 32, the beam splitter 33, the objective lens 34, and the solid-state condensing lens 35, and then passes through the near-field optical effect on the lower surface 362 of the disc 36 on which data has been written. A light spot R is formed. When the R point is "medium-strength", the optical recording material undergoes physical changes due to light and becomes crystalline. That is, all data "0" are written on the disc 36, which means that all original data on the disc is deleted. . As mentioned above, this system can "track", "write", "

CiMiMbM'K PMbM ^ pcaKraliM '^ l I6. «Ioc 9 This paper size is applicable to China National Standard (CNS) A4 specifications (210X297 public epidemic " 1 printed by A7 B7 of the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs) 5. Description of the invention ( 8) Read "," Delete ". The system can be used for" read-only type "," dye-type write-once type "," phase change-type write-only type "and" phase-change type write-and-rewrite type ", etc. Disc. Please refer to the fifth figure again. The light from the laser light source 51 is collimated by the collimator lens 52. This light is reflected by the beam splitter 53 and hits the objective lens. 54. This light is by the objective lens 54 acts as a convergent beam and is directed toward the solid-state congestion lens 55. On the lower surface of the solid-state congestion lens 55, there are two regions. The first region ranges from 0 to a diameter, and the second region ranges from diameters a to b. a < b. The radius of curvature of the surface of the first zone is r, and the radius of curvature of the surface of the second zone is r, and Γ and r are not equal. The light that hits the first zone is acted on by the surface and passes through the solid state. The lens 55 passes through the upper surface of the solid-state congestion lens 55 to form a light spot P in the space and strikes the second point. After the area light is applied by its surface, it passes through the solid congestion lens 55 to form a light spot Q on the upper surface of the solid congestion lens 55. A disc 56 having a thickness t and a refractive index η is placed on The upper surface of the solid congestion lens 55 is further above. Select appropriate numbers of t and η 'to make the upper surface 561 of disc 56 coincide with point P; and the lower surface 562 of disc 56 is very close to the Q point. The field optical effect can occur so that a light spot R appears on the lower surface 562. On the upper surface 561 of the disc 56, a continuous or concentric track groove 563 is plated and a metal reflective film is plated. The track of the track groove The distance and groove depth are appropriately matched with the wavelength and the diameter of the P pattern so that the beam reflected from the point P contains two push-pull pattern regions E and F, and the light intensity in the two pattern regions 巉 ' IE and If change with the off-track distance X of the point P. The reflected light reflected from the point ρ passes through the disc 36 and then passes through the solid state congestion

f.VUmUM'K I'nicnt ϋιχίί (ίοϋοηΆΙ t6, Juu ID) This paper size applies the Chinese National Standard (CNS) A4 specification (210X 297 mm) (I read the precautions on the back before filling this page). Temporary i nn — ^ n Ml h 1 A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (9) The lens 55 ′ passes through the objective lens 54, then the beam splitter 53, and then passes through the central hollow-out beam splitter 57 After being reflected by the reflecting mirror 58, it is finally collected by the condenser 59 'into a recovered light spot and falls on the photoreceptor 51. The light-receiving surface of the photoreceptor 510 is divided into two photosensitive regions. The light voltages generated by the zone are VE and VF respectively. The voltage νΕ is proportional to IE, and the voltage VF is proportional to IF. The voltage and the input to the subtractor 511 are calculated to obtain a signal output. This output is used as the tracking error signal. TES, (1 tes = Ve-Vf = Ie-If 〇 In addition, the lower surface 562 of the disc 56 is a completely flat surface, which is plated with a thin film of optical recording material. When data is written, the data signal Driving circuit 514 serially to the laser light source 51 to make the laser light 51 generates output light whose light intensity corresponding to "i" and "0" of the data alternates between "high intensity" and "medium intensity". This light passes through the collimator lens 52, the beam splitter 53, and the objective lens as described above. 54. After solid-state congestion lens 55 'and other components', a near-field optical effect forms a light spot R on the lower surface 562 of the optical recording material film coated with the thin film 56. As the output light intensity of the light source 51 changes, R The light intensity at the point also changes correspondingly. When the R point is "high intensity", the optical recording material is physically changed by the light and becomes amorphous, which means that the data r is written somewhere on the disc ; "" When the R point is "medium-strength", the optical recording material is physically changed by the light and changes to a crystalline state. This means that data is written somewhere on the disc "0J ° when the data is read At this time, the laser light source is caused to generate light of constant "low intensity". This light passes through the collimator lens 52, the beam splitter 53, and the objective lens 5 (^ VLisdaM'K Ι ^ · Ι «M Spccitk« lionV > t I6. «1og 1 Paper size is applicable to Chinese National Standard (CNS) A4 (210X 297 mm) ~ · ^ -^ — 1 '—HI— —111 m «lli m nn — ^ m fl ^ * 4 yi \ 0¾ ** (# -Read the precautions on the back before filling this page) Order the staff of the Central Bureau of Procurement, Ministry of Economic Affairs The cooperative prints A7 B7 V. Description of the invention (), solid-state congestion lens 55 and other components, through the near-field optical effect, a light spot R is formed on the lower surface 562 of the disc 56 on which the data has been written. The intensity of the reflected light ' reflected from the r point is related to the crystalline nature of the material. The intensity of the reflected light reflected from the "crystalline" position is strong; the intensity of the reflected light reflected from the "amorphous" position is weak. This light passes the q-point through the near-field optical effect, then passes through the solid-state congestion lens 55 ', then passes through the objective lens 54, passes through the beam splitter 53, and then is reflected by the beam splitter 57' and passes through the plane mirrors 512, 513 and the condenser lenses 514, 515. Finally, it is collected into a recovered light spot and falls on the photoconductors 516 and 517, and the photoconductors 516 and 517 generate a photovoltage Vr. The photovoltage generated by the two photoreceptors 516 and 517 is operated by the subtractor 518 to obtain a signal output, which is a data reading signal. When the data is deleted, make the laser light emit a constant "medium intensity" light. As described above, the light passes through the collimator lens 52, the beam splitter 53, the objective lens 54, and the solid-state condensing lens 55, and then passes through the near-field optical effect on the lower surface 562 of the disc 56 on which data has been written. A light spot R is formed. When the R point is "medium J", the optical recording material undergoes physical changes due to light and changes to a crystalline state. This means that all data "0" is written on the disc, that is, all original data on the disc is deleted. As mentioned above, this system can "track", "write", "read", and "delete" the disc. The system can be used for "magneto-optical erasure multiple type" discs. This paper size is applicable to Chinese National Standard (CNS) A4 specification (210X29? Mm) (Please read the precautions on the back before filling this page) Order ----------- Γ · 5. Description of the invention (N) A7 B7 In order to show the difference between the present invention and the previous technology, the following table is provided to compare the curvature of the surface of the solid-state stuffing lens of the prior art of the present invention. Points 2 1 Principle of reading and writing Near-field optics Near-field optical tracking method Push-pull method Sampling servo method Motor with low speed The upper surface of the disc is pre-engraved with continuous or concentric circular track grooves. Plated reflective flags are completely flat. Uncoated The lower surface of the disc is completely flat. The plated recording material is mostly flat, and a small portion is pitted. Although the present invention has been disclosed in the foregoing preferred embodiments, it is not intended to limit the creation of this art. Anyone skilled in this art should not depart from the spirit and scope of this work. Various changes and modifications are made, so the scope of protection of this creation shall be determined by the scope of the appended patent application. (# -Read the precautions on the back before filling this page) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs ----------- Order ----- ο 线 ---- ΊΝ-- r 3 1 This paper size is in accordance with China National Standard (CNS) A4 (210X297 mm)

Claims (1)

Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs, a bifocal optical read-write system using push-pull f tracking error detection, which includes: _ ~ light source; and ... ~ solid-state congestion lens, which enables the The light source generates two light spots, one of which is used to compliment the data, and the other light spot is used to provide a tracking error signal. 2. A dual-focus optical read-write system using push-pull method for tracking error detection, comprising: a light source; a solid-state congestion lens, which can generate two light points for the light source, one of which is used for reading 'Write data' and another light spot is used to provide tracking error signal; and a disc 'which can be used by the light source to read and write through the solid state lens. 3. A bifocal optical read-write system that uses the push-pull method for tracking error detection according to item 1 or 2 of the scope of the patent application. The light source system uses near-field optical effects to achieve data reading and writing. 4 'A dual-focus optical read-write system using push-pull method for tracking error detection according to item 1 or 2 of the scope of patent application, wherein the light source uses the push-pull method to obtain a tracking error signal. 5 'Double-focus optical read-write system for tracking error detection using push-pull method according to item 1 or 2 of the scope of patent application, wherein one side of the disc contains optical recording material and the other side is engraved with a continuous pattern The groove-like track is plated with a reflective film over the entire surface. 6. Use the push-pull method as the tracking error according to item 1 or 2 of the scope of the patent application. The paper size is in Chinese National Standard (CNS) A4 (210X297 mm) .- 'Ό © I1I ——II III n II line (please read the precautions on the back before filling this page) A8 B8 C8 D8 The dual-focus optical reading and writing system for patent range detection printed by the Consumer Cooperatives of the Central Government Bureau of the Ministry of Economic Affairs. An optical recording material is stored on one side, and concentric groove-shaped tracks are engraved on the other side, and a reflective film is plated on the entire surface. 7. A bifocal optical read-write system for tracking error detection using a push-pull method, comprising: a light source passing through a collimator lens, a beam splitter, and an objective lens; a solid-state congestion lens, which can pass through the objective lens The light source generates two light spots, one of which is used to read and write data, and the other light spot is used to provide tracking error signals; a disc, with optical recording material stored on one side and continuous on the other side The groove-like track is plated with a reflective film on the entire surface. A light spot generated by the solid-state condensing lens causes a near-field optical effect to cause a physical change in the optical recording material on one side of the disc. The other light spot generated by the lens illuminates the detection error signal of the track on the other side of the disc; the optical recording material on one side of the disc is reflected by the near-field optical effect of the light spot, and is reflected by the solid congestion lens, objective lens, The beam splitter and condenser, to the photon, can read the optical recording material; and the reflective film on the other track of the disc is irradiated and will be reflected by the solid congestion lens, objective lens, beam splitter, reflector and condenser to the photosensitive Child Compare with the subtractor to detect the error signal. 8'A dual-focus optical read-write system that uses the push-pull method for tracking error detection, which includes: a * light source that passes through a collimator, beam splitter, and objective lens; (Please read the precautions on the back before filling (This page)-Binding. Ί IVten.Sp.ci, > nCMi〇, V, j | fiagc 15 This paper size applies to Chinese national standards (CNS > A4 specifications (210X297 printed by the Central Consumers Bureau of the Ministry of Economic Affairs, Consumer Consumption Cooperatives) System A8 B8 § ______ VI. Patent application scope-A solid-state condensed lens, which can generate two light spots through the light source of the objective lens, one light spot is used to read and write data, and the other light spot is used to provide tracking error Signal; a disc with optical recording material stored on one side, and a concentric circular groove track engraved on the other side, and a reflective film plated on the entire surface, a light spot generated by the solid congestion lens is near The field optical effect should cause a physical change in the disc-side optical recording material, and the solid state is blocked. Another light spot generated by the mirror illuminates the detection error signal of the track on the other side of the disc; the disc One side of the light recording material is The near-field optical effect of the light spot reflects through the solid-state condensing lens, objective lens, and beam splitter. The reflected light passes through the two beam splitters, and then passes through a plane mirror, a condenser lens, and a photon. The optical recording material must be read; and the reflective film on the other side of the disc is irradiated and reflected by the solid-state condensing lens, objective lens, beam splitter, reflector, and condenser to the photon 'and the subtractor. Measured error signal. 9. An optical read-write disc with optical recording material stored on one side and a continuous or concentric groove-shaped track engraved on the other side and a reflective film plated on the entire surface. 1 0. A tracking error detection method includes the following steps to provide a light source; the light is passed through a solid-state congestion lens to generate two light spots; one of the light spots is irradiated on the surface of the dish with reflection plating. Reflected in the shape of an orbit, the reflected light contains two pattern areas. The pattern area is based on the light Π: \ Ι.ίη < 1 > ΨΚ faicnlSpcciliealion'USI tC.Uoe 1 6 This paper is in accordance with the Chinese National Standard (CNS) A4 specifications (2 丨 O X297 mm) (Please read the precautions on the back before filling in this page) Packing. • ο Order. A8 B8 C8 D8 6. The range of the patent application point deviates from the track and changes; and it is detected by a subtractor Tracking error signal. Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the precautions on the back before filling this page) C: \ Un (Uv) 'K IVlcnl SpecificalkmS6l l6. ≪ loc' This paper size applies China National Standard (CNS) A4 specification (210X297 mm)