TW472244B - Tracking error detection method and device of near-field optical read/write system - Google Patents

Abstract

The present invention provides a tracking error detection method and device of near-field optical read/write system. Tracking grooves are installed on the non-data-storage surface of the optical recording medium. In accordance with means to generate two signal-pickup light spots, the data on the data-storage surface can be accessed by the first light spot. The second light spot focused on the tracking groove is used to detect the tracking error signal (TES) by push-pull tracking method, so as to increase the data storage density of the near-field optical read/write system of the optical recording medium. Without the cooperation of high rotation speed motor, the purpose of tracking error detection can be achieved.

Description

472244 V. Description of the invention (1) '----___ [Scope of application of the invention] The telegraph system has a method for measuring near-field 氺 and Jing write 糸 U measurement method MW "a system of tracking error debt can be raised; There is another method and device applied to the near-field optical reading and writing system, Tongshi, and recorded media, and capable of detecting tracking errors using the push-to-track method. [Background of the Invention] Light The Beixun read-write system takes the generation of a light spot with a small diameter as a priority. The smaller the light spot, the larger the capacity of the information stored on the recording medium. The aperture (Numerical Aperture 'ΝΑ) is inversely proportional. (T Near-field optical read-write principle, please refer to "Figure 1", is the convergent light beam output by a pass 1 first read-write head η from the lower surface of a plano-convex lens 12 Incorporating and limiting the propagation within the plano-convex lens 12, a large N A value can be created on the upper surface of the plano-convex lens 12, and a light spot (light A) with a small diameter is obtained. The lens with this function is a solid-filled lens (Solid Immersio n Lens, SIL). NA—nx sin0, two n (nx sin0) = n2x sin g can be found through proper setting of ten, where Θ is the convergence angle of the light beam output by the conventional read / write head i 丨. When the film is close to the side plano-convex lens, 2 ′, due to the near-field optical effect, part of the light waves will pass through the air gap (thickness of about 0.15 // m) between the plano-convex lens 12 and the disc 13 and below the disc 1 3 A light spot of the same diameter as light spot a (light spot B) is formed at 31 on the surface. The light is reflected by light spot β. The physical properties of the reflected light (intensity kite polarization vector) are affected by the data stored at that point, and the reflected light From point B, the “near-field optical effect occurs again and passes through the air gap in the opposite direction” back to the 5 472244 Description of the invention (2) Convex lens 12 and the traditional nest reader n — & physical properties of light The tablet 统 unified type write head 11 detects the information on this noise month 13. And: Knowing: Field:: Read-write system, "The disc η used, picture" is not, it has two flat Let's make the following table> face 1_. There is a thin film of optical recording material, and the disc 'SIL12, let the light spot β fall on this film, = near. The upper surface 1 3 2 has no special use. 4 The near-field optical reading method of uterine system # | ΓίSERVO'Uampie ^ ff uses non-compliance error detection 1 female virtual circle order is divided into several virtual sections: = start Pre-engraving—a tracking signal sampling pit ", during operation, 2 shots, η: the light spot generated after falling on the tracking signal sampling pit 24 and then reflected: the intensity of the reflected light is a function of the amount of paranoia in the light spot , Detection = 4 can determine the amount of off-track error of the light point, and send the paranoid error $ from the detection to the person reading (serving the machine ^, you can correct the paranoia of the objective lens. But the first two and the second assume that the bias execution is constantly occurring at a frequency of 2 kHz, and the second t t correction, we must try to generate a paranoid error photocurrent waveform with a frequency of 2 kHZ. Therefore, the sampling of the compliance signal is small. The frequency of appearance must be at least ',', 4kHz, assuming that there are 50 sections in the track-circle, and the motor speed is f

Ps, then fx5〇 =: 4ktlz, through calculation f = 80rps = 4800rpm, the high-speed requirement of this policy must be realized by a high-speed motor, and because of the high-speed motor IX, get, so the near-field optical read-write head It is not easy to reduce the cost of the s method. The point is that the existence of the tracking signal sampling pit 24 occupies a portion of 4? 2244 to store 0 / ^ 'light points from the above, t: 5il. ^ '遂 不 #' to cause it to generate a differential signal, then the purpose of the invention / in view of this girl can be used to improve the storage density. In the system of the present invention, the groove is not set according to the above-mentioned storage surface, and the near-field light error servo (S amp 1 e) is not provided. There are two kinds of surface curved pickup light spots. The invention saves more space for data, thus reducing the total data on the disc. Knowing that it is necessary to provide not to take two light spots to avoid adoption and overview], the shortcomings of the near-field optical system of the present invention are stored in only To generate a light spot, near-field optical shielding, and to extract tracking error-like servo method. If a new system can be created, which is used to read the data and detect the tracking error caused by the servo sampling error method. The purpose is to change the reading and writing system. Another purpose is to provide a speed motor with its device. The present invention relates to the method and purpose of high-speed push-pull tracking, which can be used to generate f, system, and gas. The difference (TES: Servo, the solid state of the present invention rate is based on reading and writing data). ≫ No. _) method requires a more stuffed lens (the optical recording medium in the near-field optical reading and writing of good practice) of Applied to the near-field optical read-write combination, it can easily detect the non-data method of obtaining the optical recording medium, the method of obtaining the tracking error signal, the pick-up light point, the first light point of the material, and the -light point. Therefore, in the embodiment of improving the sampling and sampling pits and the high speed Ma Yuanjia, two signals are generated by using SIL) to increase the compliance lock route in the same track groove. According to 472244 V. Invention description (4)

Japanese Journal 〇f AppUed physics >

Vo 1.38 (1 9 9 9), the calculation results mentioned in ppj 7744 776 learned that: within the ditch, three compliance-locked routes will be allowed, and data can be stored under the added routes, making this The incubation density of the invented near-field optical read-write system can be increased up to three times. In order to make the above and other objects, features, and advantages of the present invention more obvious, the following is a preferred embodiment, which will be described in detail with reference to the accompanying drawings. f [Explanation of the embodiment of the invention] ^ = Refer to "Figure 3A", according to the technology disclosed in the present invention, ff has. On the upper surface 361 of the optical recording medium 36 (non-data storage ^ = a ditch 3 is provided) 6 丨 '' Reuse one can generate two signals: = :: means' to generate the first light spot for reading and writing data, and the second light spot for :: track error (TES) signal. A better solution is to fill in the solid with a solid,. T ', brother (S1L) 3 5 to generate the above two light spots, grab two, a > the lower surface (that is, the side close to the laser light source) ) Has two kinds of surface curvature. When the lens (Sichuan) is 35, the first beam of the surface curvature field condenses into two lights because it passes through the Haigubei packing, and the surface curvature is different. " The lower surface 362 of the optical recording medium 36 = uses the principle of near-field optics to read and write data, and the second surface m surface 361 (not a data storage table) is in the groove 3611, and cooperates with the push-pull tracking method (push — puii racking method) to generate the second light point number (TES). Tracking block error provided by Zhongyou "Page 7 47224 4. V. Description of the invention (5) Please refer to "Figure 3B". On the upper surface 361 of the optical recording medium 36, there are continuous rail grooves 3611, or as shown in "Figure 3c" It is a concentric circular groove, and a metal reflective film is plated thereon. The groove pitch and groove depth of the groove 36 11 are appropriately matched with the output beam wavelength and the diameter of the p-point (the second κ-light point). 'The light beam reflected from the point P contains two push-pull pattern areas e and f. As shown in "Figure 4A", the light intensities in the two pattern areas, Ie and I f' The derailment distance of the point changes, as shown in Figure 4B. Let TES = le — if, when point p is located in the center of the orbit, TES = 0, and when point P deviates from the center of the track, 0 Or TES > 0, as shown in "Figure 4C". For the structure of the entire near-field optical read-write system in the present invention, please refer to "Figure 5", the output beam emitted by a laser light source 31, The straight lens 32 becomes parallel light, and is reflected by a beam splitter 33, and then travels to an objective lens 34 to converge the light beam and is directed to a solid-state stuffing lens (SIL) 3 5. The objective lens 3 4 The solid-state packing lens (SIL) 35 is connected by a bracket 317 to form a focusing unit 345. As described in the rain, the lower surface of the SIL 35 is divided into two regions with different surface curvatures, and the diameter of the first region ranges from 0 to a, its surface curvature radius is infinite. The diameter range of the second region is a to b, where a < b, its surface curvature radius is a finite value. After the light beam directed to the first region is acted on by its surface, it passes through the A solid-filled lens (SIL) 35 is formed in space to form a “light point P (the first point of the description)”. The light beam directed to the second area is passed through the SIL35 and formed on the upper surface of the SIL35. A light spot q (the aforementioned first light spot). An optical recording medium 36 having a thickness t and a refractive index n is placed on the upper surface of the solid-filled lens (SIL) 35.

Page 472244 V. Description of the invention (6) The appropriate values t and 1 are selected so that the upper surface 6 丨 of the optical recording medium 36 coincides with the P point, and the lower surface 3 62 of the optical recording medium 36 is cleaned. q is so close that the near-field optical effect can occur, and a light spot R appears on the lower surface 362. After returning the light beam reflected from the P point contact, after passing through the optical recording medium solid-filled lens (SIL) 35 and the objective lens 34, the output light beam and the returning light beam are separated into different ones by minute t: then the The returning beam continues to pass through a central hollow-out beam splitter "make = different tracking beams and data beams, in which the tracking light beam spot: fall: reverse :: pass-condenser 39, and finally converged into-recycling light Dianluo has 31 photoreceptor areas E and F in one photon, which are divided into two terms by the two photon = surface, where the positive two light = decimol V lele-U, TES has a tracking error signal TH —, send _4 to-and the maximum voltage value, Φ of the tracking servo circuit unit 3 1 2 and preset a plurality of reference voltages vid λ, < Vmax, the relationship is as "the 6th Vmin < Vi 312 compares TES with Vi, based on "=", the tracking servo circuit unit. As a result of the comparison, a correction voltage is generated if TES > V i, then the correction voltage Ud >0; the road unit 312 will generate-a positive value, to drive the focusing unit to be sent to a cycle The rail actuator 5 moves in a certain horizontal direction. The objective lens

Page 9 472244 V. Description of the invention (7) After the plug lens (SIL) 35 is moved, it will cause p-point paranoia 3 4 and the solid-state lane filling 蚬 wl) 3 d 杪 勑, it will cause p-point derailment and The state changes so that the TES value and Vd value also change. This procedure is repeated until TES = V i. If the effect of the tracking actuator 3 丨 5 is sufficiently sensitive, then TES is almost always equal to Vi, and it can be seen that tes 悝 is equal to-a positive value constant or zero, so the point P is kept off the center of the orbit or exactly On a certain virtual route, that is, point P is locked on a certain route. k If TES < Vi, the tracking servo circuit unit 312 will generate a positive voltage (Vd < 0), and the voltage will also be sent to the tracking dynamics 315 to drive the focusing unit 345 to another Relying on the solid-filled lens (SIL) 35, moving ^ thousands of squares will move towards making ^ =: the state changes, so that the TES value and Vd value will continue to be repeated until TES = Vi A If the effect is sensitive enough, TES ^ ... the negative constant or zero of the orbital actuator 315, so the other-virtual route in the p-point track, that is, the p-point is locked ;: the other center :: as explained above The procedure is called "Following on another route." The constant voltage, value corresponds to the lock :: lock, ^ is called the center of the lock. Since Vi can be multiple values, the '4 route does not have to be on the road. The track-locked route can be plural. Although there is only one line in the text, it is: below the line,-one: read = Figure 7 ", the number of each-that is, the maximum value of 7" or "Erase" ", Vi is the quotient of the diameter and distance. ',; The light point at point R (or Q point) The optical surface of the body 36 (data 472244 V. Description of the invention (8) storage film storage surface) applied to the present invention is a completely flat plane, It is plated. The tracking error detection method of the present invention can be applied to thin recording media 36 of two materials, such as "read-only type", "dye 々 二 # of the same form of optical eight", scolding "one offense" phase change "Write only once type", "Phase change type _ yi xi sheng sheng", optical erasing multiple times type ", etc., can use the above formula = ^ type" and "magnetism list" phase change erasing multiple times "Type" explains the working principles of "& track * route" /, δ shell "," should do "rubbing". "Ma" and please refer to "Figure 5" again. When writing, turn the data signal string to the drive circuit 314 'of the laser light source 31 to make the laser light source 3 string two to ,,: T, ,, 0 ,, Correspondingly, the high-intensity " ,,, and middle-in-law " Rabbi :, the output beam of the strong intensity of the intensity of the parent's substitution, the output beam is as described in 刖, passes through the collimator U, said the beam splitter Device 33, the objective lens 34 and the solid-filled lens (SIL) 35 and other components / rear '& by the near-field optical effect, a light spot R is formed on the lower surface 362 of the optical recording medium 36 coated with an optical recording material. The intensity of the light emitted by the laser light source in the 31 rounds is changed: the light intensity at point R also changes accordingly: 时 When a strong beam is received, the optical recording material at this point undergoes a physical change to become amorphous. Data is written at this point, when the medium-intensity beam is received at 1? Point, the optical recording material at that point changes physically and becomes crystalline. This means that data, 〇. When reading, the laser light source 31 is caused to emit a constant, low-intensity β light beam, and the light passes through the collimator lens 32, the beam splitter 33, the objective lens 34, and the solid-state stuffing lens (as described above). SIL) 35 and other elements, through the near-field optical effect, a light point R is formed on the lower surface 362 of the optical recording medium 36 on which the actual material has been written, and the return beam reflected from the R point is reflected in the crystalline state.

472244 V. Description of the invention (9) The intensity of the transmitted light is strong, and the light intensity of the reflected light at the position ^ of the crystal 6 is weak. The light beam passes through the Q point through the near-field optical effect and then passes through the solid-state packing lens (SIL) 35. The objective lens 34 and the beam splitter 33 are then reflected by the central hollow-shaped beam splitter 3 7 ′, and then they are collected by the condenser lens 3 1 6 into a recovered light spot and fall on the photon 313. A photovoltage VR is generated at the photon 313. VR is proportional to the intensity of the reflected light. When the size of VR is detected, it is known that the reflected light comes from "crystalline, evil" or "amorphous state", that is, the data is 0 or 1, so VR is the data read signal RFS. . ^ ^ ^ ^ ^ ^ ^ ^ ^, When erasing, 'make the laser light source 31 emit a light beam of constant "medium intensity", as described above, the light beam passes through the collimator 32, the beam splitter 33, the After the object = 34 and the solid-filled lens (SIL) 35 and other components, a light spot R is formed on the lower surface 362 of the optical recording medium 36 on which the data has been written via the near-field optical effect. "Medium" brightness, so =. Haiguang § The recorded material is physically changed to a crystalline state, that is, all data is written on the optical record, and 0 is equivalent to erasing all the data attached to the optical recording medium. Although the present invention has been disclosed as above with a preferred embodiment, it does not use God # ^ The present invention 'Any person skilled in the art, without departing from the essence of the present invention: within the circle' should make a few changes and retouching 'Therefore, the warranty of the present invention * is mentioned, which is defined by the scope of the patent application attached.

， Effectiveness JP <, κ.Λ / Light Warfare The present invention uses the means of generating two signals to pick up light spots to track separately. The recorded media accesses the data and locks on the record, so the push-pull cycle can be used. / (Push-pull tracking method)

Page 12 472244

Page 13 472244 Brief description of the drawings [Schematic description] Figure 1 shows the structure of the conventional near-field optical reading and writing system; Figure 2 shows the structure of the ten disks of the conventional near-field optical reading and writing system. Schematic diagram; Figure 3A, which shows the structure of the main technology in this creation; Figure 3B, which shows the structure of the first embodiment of the optical recording medium in this creation; Figure 3C, which shows this creation Schematic diagram of the second embodiment of the Chinese optical recording medium; Figure 4A, which shows the relationship between the reflected light and the push-pull pattern area; Figure 4B, which shows the relationship between the push-pull pattern area and the off-track distance; Section 4C Figure 5 shows the relationship between the detrack distance and the push-pull tracking error signal TES. Figure 5 shows the structure of the entire near-field optical read-write system. Figure 6 shows the push-pull tracking error signal TES and reference. The relationship diagram of the voltage Vi; and FIG. 7 is a schematic diagram showing a plurality of tracking lock routes. [Illustration of Symbols in the Schematic Diagram] 11... 13 ..... .............. upper surface 2 4 .............. Tracking signal sampling pit

Μ Μ 1 11

Page 14 472244 Schematic description 31 ........ Laser light source 32 ... Collimator 3 3 ......... Beamsplitter '3 4 .... Don't Mirror 35 ...... Solid Packed Lens 34 5 ........ Focus Unit 36 ...... .......... Optical recording medium 3 61 ........ Upper surface 3611 ............ ..... Ditch 3 6 2 ..... Lower surface 37..... 38 ................... Reflector 3 9 ................... Condenser 310 ... .............. Photon 311 ........ Subtractor 312 ............ .. compliant servo circuit unit 313... Photon 314... Drive circuit 315... .............. Follow Actuator 316 ........ Condenser 317 ........ .........support

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Claims (1)

472244, patent application scope 1, a kind of near-field optical reading club will follow from # 虹 〆 备 π + t # μ to write the tracking error detection method of the system is wide and far) The Recording Office has grasped from time to time ... _ 一 〆-¾ _. ^ 1 The stupid Bei Xiong has been greatly improved, and does not need to. The cooperation of two speeds and examinations, which includes at least: Yu Guangguang . A track groove is provided on the non-data storage surface of the recorded media; a means for generating two signal pick-up spots is provided to generate a first light spot on the data storage surface of the optical recording medium for reading and writing data and a Focus on the second light spot at the track groove; and 1J1 pull-type tracking rabbit (ush-pull tracking method) to obtain the tracking error represented by the tracking beam reflected by the second light spot. Signal (TES). 2. The tracking error extraction method for a near-field optical read-write system as described in item i of the patent application range, wherein the track groove is continuous or concentric, and a reflective film is coated thereon. 3. The tracking error detection method of the near-field optical read-write system as described in item (1) of the scope of the patent application, wherein the means for generating two signal pickup spots is by bringing a lens close to the laser light source. -The surface is divided into two regions with different surface curvatures, so that a round of outgoing light emitted by the laser light source passes through the lens, and the two signal pickup light spots are formed on the optical recording medium. 4. Tracking error detection method of near-field optical read-write system as described in item 3 of the Shen-Jin patent scope, wherein the lens is a solid-filled lens (Sol id Immersion Lens, SIL). Page 16 472244 6. Patent application scope 5. The tracking error detection method of the near-field optical read-write system as described in patent application scope 3), where it is more convenient * to use a collimator lens to output the beam Processed as a parallel beam. 6. For the tracking error detection method of the near-field optical read-write system described in the third item of the patent application, an objective lens can be used to convert the output beam into a convergent beam and shoot the lens. . 7. The tracking error detection method of the near-field optical read-write system as described in item 1 of the scope of the patent application, wherein the push-pull tracking law enforcement further includes separating the path of the beam and using a beam splitter to The output beam is separated into a different optical path from the return beam reflected from the optical recording medium. 8. The tracking error detection method of the near-field optical read-write system as described in item 1 of the scope of the patent application, wherein the push-pull tracking method further includes separating the path of the beam and using a central hollow-out beam splitter To separate a real light beam reflected back from the first light spot and a tracking light beam reflected back from the second light spot to different optical paths. 9. The tracking error detection method for a near-field optical read-write system as described in item 8 of the scope of the patent application, wherein a reflector can be used to change the traveling direction of the tracking beam or the data beam. 10. The tracking S-difference detection method for a near-field optical read-write system as described in item 8 of the scope of patent application, wherein the tracking beam falls on a photon on a light-receiving surface divided into two photosensitive areas, A photovoltage is generated by the two photosensitive areas individually, and the two photovoltages are sent to a subtractor for calculation, to obtain the tracking error signal (TES). Page 17 472244 VI. Patent application scope 1 1. The compliance error detection method of the near-field optical read-write system as described in item 10 of the patent application scope, wherein the generation of the tracking error signal (TES) is more A condensing mirror can be used to arrange the light path between the central hollow-out beam splitter and the photoreceptor for converging the observing light beam on the photoreceptor. 1 2. A compliance error detection device for a near-field optical read-write system, which will reflect an output beam generated by a -λ—a laser light source, irradiate an optical recording and recording medium with a track groove and reflect a return beam ' And use the Push-pull tracking method T '. Track detection rig, the difference is at least; Include: / One track is set to the non-data storage of the optical recording medium Surface; -i 一 全. ¾ ... ί 'arranged on the optical path of the optical read-write system, the output beam and the return beam can be separated into different optical paths respectively; (a focusing unit, y contains an objective lens A solid-filled lens (Solid Immersion Lens, SU) is disposed in the optical path of the optical read-write system. The objective lens applies the output beam to a convergent beam and shoots toward the solid-filled lens. The solid-filled lens is near A stack of the 5H objective lens is divided into two regions with different curvatures, so the convergent beam will form two light spots after passing through the solid-filled lens, respectively falling on the data storage surface of the optical recording medium and the track groove, where First light point In reading and writing data, ❿ second light spot while executing error signal for providing a cycle; Central hollowing profile & VI. Patent-pending optical path, separating the two j ^ backhaul beams in the optical read-write system into separate beams that are not reflected from the optical recording medium; the same tracking beam With a data and a photoreceptor, the configuration & light receiving surface is divided into two senses ~ the optical path of the tracking beam is pressed; and the region 'g 1 f method for sensing the compliance beam is two pairs of two photoreceptors Photovoltaic voltages Λ 隹 式 2 tracking error signals 形成. 2: The scope of the patent: The near field optical read / write / nine resolution measurement device described in item 12 of the stomach, which also includes a collimator configured on the optical path of the write system, which is used for the laser light source. The output 4 beam is processed into a parallel beam. The compliance error detection device for near-field optical reading and writing as described in item 12 of the scope of the patent application, which further includes a reflector arranged on the optical lens to change the tracking beam or the data light travel direction. The near-field optical reading and writing device tracking S-difference detection device according to item 12 of the scope of the patent application, which further includes a condenser lens, 2 a light path between the central hollow-out beam splitter and the photon, 6 Focus the tracking beam on the photon. The near-field optical read-write and U-track detection device as described in item i 2 of the scope of the patent application, wherein the track groove is connected to the return light of the Lianbin-like or unified system, and its photoelectricity is used to systematically light the student's system The return beam system is configured to be system concentric and the reflective surface is coated with a reflective film 472244 Page 20