200849232 九、發明說明： 【發明所屬之技術領域】 之尋執方法，更明200849232 IX. Description of invention: [The technical field of invention]
本發明係關於一種用於光碟資訊軌 之’係關於多層光碟資訊軌之尋執 【先前技術】The present invention relates to a method for a disc information track to search for a multi-layer disc information track. [Prior Art]
美國專利第5923632號揭示多層光碟之光學讀取裝置， 其中藉由-光源產生的光束係分成一主光束、一第一側光 束與-第二側光束。主光束係聚焦在主光點；第一側光束 與第二側光束係分別聚焦在多層光碟的第一與第二側光 點。來自主光點、第一與第二側光點的反射光束係藉由主 光束接收構件、第一側光束接收構件與第二側光束接收構 件而光電轉換，以獲得推挽尋執信號。第一側光束接收構 件與第二側光束接收構件係與主光束接收構件隔開一距 離，以致於不會與第一與第二側光束接收構件形成干擾係 源自從多層光碟的一未聚焦資訊層反射的主光束。此解決 方案可能係技術性挑戰，因為使用高精確度來定位第一側 光束接收構件與第二側光束接收構件可能不易達成。可能 會有來自多層光碟的一未聚焦訊層所反射主光束的一些干 擾量。此可造成影響記錄/重製資料的不準確的推挽尋執 信號。 具有用於獲得準確的推挽尋轨信號之方法係有利的。具 有用於獲得準確的推挽尋軌信號之一光學讀取單元亦係有 利的。 【發明内容】 129947.doc 200849232 本發明揭示一牙重多層光學記錄載體資訊執之#向尋軌之 方法。該方法包含產生從落在一光學偵測器上的一主光 ”、占 第一側光點與一第二側光點之光所取得的一推挽尋 轨仏说其中该主光點、該第一側光點與該第二側光點係 分別藉由聚焦一主輻射光束、一第一側輻射光束與一第： 側輕射光束形成，其係考慮從多層光學記錄载體的離焦層 之主光點之反射所引起的一背景光點之效果。U.S. Patent No. 5,932,632 discloses an optical reading apparatus for a multilayer optical disc in which a light beam generated by a light source is divided into a main beam, a first side beam, and a second side beam. The main beam is focused at the main spot; the first side beam and the second side beam are respectively focused on the first and second side spots of the multilayer disc. The reflected light beams from the main spot, the first and second side spots are photoelectrically converted by the main beam receiving member, the first side beam receiving member and the second side beam receiving member to obtain a push-pull seek signal. The first side beam receiving member and the second side beam receiving member are spaced apart from the main beam receiving member by a distance such that no interference with the first and second side beam receiving members is derived from an unfocused from the multilayer optical disc The main beam reflected by the information layer. This solution may be a technical challenge because the use of high accuracy to position the first side beam receiving member and the second side beam receiving member may not be easily achieved. There may be some amount of interference from the main beam reflected by an unfocused layer of the multilayer disc. This can result in inaccurate push-pull seek signals that affect the recording/reproduction data. It is advantageous to have a method for obtaining an accurate push-pull tracking signal. It is also advantageous to have an optical reading unit for obtaining an accurate push-pull tracking signal. SUMMARY OF THE INVENTION 129947.doc 200849232 The present invention discloses a method for tracking a tooth-heavy multilayer optical record carrier. The method includes generating a push-pull track obtained from a main light falling on an optical detector, the light occupying the first side spot and the second side spot, wherein the main spot, The first side spot and the second side spot are respectively formed by focusing a main radiation beam, a first side radiation beam and a first side side light beam, which are considered to be separated from the multilayer optical record carrier. The effect of a background spot caused by the reflection of the main spot of the focal layer.
ί. 一本發明揭示一種用於多層光學記錄載體之光學讀取單 凡。該光學讀取單^包含—控制單元，其配置用以產生從 落在一光學_器上的—主光點、—第—側光點與一第二 ，光點的光所取得之一推挽尋執信號，其中該主光點、該 弟一側光點與該第二側光點係分別藉由聚焦一主輻射光 束、一第一側輻射光束與一第二側輻射光束形成，其係考 慮由多層光學記錄載體的離焦層之主光點之反射所引起的 一背景光點之效果。 卜獲彳于夕層光學記錄載體的準確推挽尋執信號之方 法可使用電腦程式實施。 【實施方式】 q 一 =己錄載體2可為一多層可記錄（R)或可重寫（rw)類 八 7孔了儲存或5己錄在資訊軌上，例如DVD+RW、 DVD-RW、DVD+R、HD_DVE^BD+RW。 參考圖1 射二極體） 3 2 a通過* ，光學讀取單元30具有一輻射產生器31(例如雷 ^其配置用以產生一輻射光束32a。輻射光束 刀光為33與一物鏡34。物鏡34聚焦輻射光束32b 129947.doc 200849232 在光學記錄載體2上的焦點F。輻射光束32b從光學記錄載 體2(反射㈣光束32e)反射，並通過準直透鏡^與物鏡 及分光器33(光束32d)，並通過一像散透鏡刊（用於聚焦 "吳差^號產生）以到達一光學偵測器3 5。 對於達成及維持正確聚焦輻射光束32b在光學記錄載體2 的一所需位置上而言，物鏡34係軸向可置換安裝。 Γ c 限之每一者上的輻射入射量 參考圖2，光學偵測器3 5包含複數個偵測器區段（在四個 谓測器區段35a、35b、35c及35d的情況中），其能夠分別 提供個別们則器信號A、B、咖，#示在四個债測器象 中線3 7將第一及第四區段 35a及35d與第二及第三區段35b&35c分開。此外，光學偵 測器35包含兩個偵測器區段35e&35f，其能夠提供偵測器 h唬E及F，指示在偵測器區段（即350及35f)之每一者上的 光入射里。此外，光學偵測器35包含兩個偵測器區段35g 及35h ’其能夠提供個別偵測器信號〇及η，指示在偵測器 區段（即35g及35h)之每一者上的光入射量。 推挽方法與三光束方法通常係已當作尋執伺服方法用以 將資料記錄在光學記錄載體上/從光學記錄載體重製資 料。在該等方法之中，典型一者係差動推挽方法。 差動推挽方法的原理係示意性說明於圖3中。輻射產生 器31產生的輻射光束係通過光學構件39(參見圖丨），並分成 主幸田射光束、一弟一側輕射光束與一第二側輻射光束。 主輻射光束產生主要光點Μ，第一側輻射光束產生第一側 光點S]，且第二側輻射光束在光學記錄载體2上產生第二 129947.doc 200849232 側光點S2。藉由光學讀取3 1形成的三個輻射光束光點（主 光點Μ與側光點1及so經定位使得側光點8)及&以半磁軌 間距P對主光點Μ偏移。纟自主光點顺侧光點^及§2兩者 的反射輻射光束係藉由光學偵測器35進行光電轉換，使得 推挽尋軌信號可於光點Μ、8]及82獲得。光電轉換信號^ 用來獲得資料，並伺服光碟機需要的信號，例如徑向、焦 • 點與傾斜控制信號。例如，一資料信號、一尋軌信號，與 ' 水焦误差仏號通常使用下列方程式獲得： ( 資料=(A+B + C+D) 尋軌WA+DHB+C^-I^e+ghf+h)]，其中k係倍増因數， 聚焦=(A+C)-(B+D) 應庄思，主光點在此視為中央光點或主要光點，且側光 點視為衛星光點或子光點或次要光點。此外，光學系統30 可、、二適§地修改以形成主光點M與側光點s 1及S2。 發明人已發現，對於雙層或多層光學記錄載體而言，失 G 冑出現在用於徑向尋執的三光點推挽尋難號。發明人亦 已I現k些失真的原因不僅係同調串擾（即具有離焦層 ’ 光點之第一側光點與第二側光點的干擾），且大部分變= 出現在離焦光點本身。 一仗圖4清楚看出’來自主光點M與第―側光點h及第二側 =S,2的反射輻射光束落在光學偵測器35。亦應注意，一 夕光”占亦係因光學記錄載體2的離焦層反射而形成。此 外來自兔景光點的反射輻射光束係入射在所有偵測器區 段（即 35a、ί c 、35c、35d、35e、35f、35g 及 3 5h)。不具 129947.doc 200849232 有側光點（即不具有\及的測量顯示側光點81及&之位 置上彳貞測到的信號變化。此係在圖5A及5B顯示。 在圖5A中，水平軸代表推挽尋軌信號值，且垂直軸代表 具有第一側光點與第二側光點之推挽尋執信號的振幅。在 圖5 B中，水平軸代表推挽尋執信號值，且垂直軸代表不具 有第一側光點與第二側光點之推挽尋執信號的振幅。從圖 5 A及圖5B可觀察，推挽尋軌信號的失真振幅係極類似於 不具有側光點存在的失真。參考圖，推挽尋執信號值的 振幅係由離焦層反射之光學偵測器35上的光點變動所引 起。 因此，本發明揭示一種多層光學記錄載體資訊執之徑向 尋軌之方法。該方法包含產生從落在一光學偵測器上的一 主光點、一第一側光點與一第二側光點的光所取得的一推 挽尋執信號，其中該主光點、該第一側光點與該第二側光 點係分別藉由聚焦一主輻射光束、一第一側輻射光束與一 C, 第二側輻射光束而形成，其係考慮來自多層光學記錄載體 之離焦層的主光點之反射所引起的一背景光點之效果。 推挽尋軌信號係考慮背景光點變動而產生，因此產生準 、 確的推挽尋軌信號值。本質上，在此揭示的方法從具有可 - 推論光束著陸的側光點信號來區別三光點推挽尋執信號中 失真（即背景光點變化）的原因。 在一具體實施例中，產生主光點、第一側光點與第二側 光點的推挽尋軌信號的方法_包含在圖6說明的步驟。現 參考圖6,在步驟6〇2中，i生第一側光點Si(參考圖3)與第 129947.doc 200849232 二側光點S2(參考圖3)的第一側輻 列？田射先束與第二側輻射光束 會關閉。在步驟604中，與背景光點相關聯的-第一信號 係藉由光電轉換來自背景光點的反射輕射光束而測量。在 步驟606中，產生第—彻丨本c 座生弟側先點S】（參考圖3)與第二側光點 S2(參考圖3)的第一側輻射光束與第二側輻射光束會開啟。 在步驟608中，盘背景井點、贷 .,, 月不尤點弟一側輻射光束、與第二側 輻射光束相關聯的一第二信號係藉由光電轉換來自背景光 點：第-側輕射光束與第二側輕射光束的反射輻射光束而 在步驟610中’-校正信號係基於該第—信號與該 第二信號的差而計算。在步驟612中’主光點、第一側光 點與第，側光點的推挽尋軌信號係藉由使用來自該主光 ”’占°亥第側光點與該第二側光點的光電轉換（即光電信 號）反射輻射光束上的校正信號而產生。開啟與關閉第一 側光：與第二側光點係有利的’由於不具有側光點(即不 具有第一側光點與第二側光點）的信號可測量，並可用作 與背景光點相關聯的測量。具有側光點（即具有第一側光 =與第二側光點）的信號可測量’且當（正常）在三光點推挽 尋，信號中’ Λ目前係補償光束著陸。推挽尋軌信號係考 慮背景光點變動而獲得，因此推挽尋軌信號係準確。此改 善來自光學記錄載體的資料之記錄/重製。 在進一步具體實施例中，開啟及關閉第一側輻射光束 與第二側輻射光束包括透過一可切換光柵來傳送主輻射光 束，該可切換光柵具有下列狀態：一啟動狀態，除主輻射 光束外，该狀態產生第一側輻射光束與第二側輻射光束；' 129947.doc 200849232 及-關閉狀態，其只傳送該主輕射光束。換句話說，在關 狀九、中’第-側輻射光束與第二側輻射光束係不傳送。 ^-小且相當簡單的光學元件可容易引用在光學光路徑 日守’此係有利實施方案’因此允許具有對光學驅動器之架 構的剩餘部分極小變化之成本效益解決方案。 〃 在仍然進—步具體實施例中，可切換光栅包含—液晶材 料與-聲光調變器之一者。光柵係藉由如圖7所示的液晶 材料而達成切換。光柵係經由存在透明結構（例如藉由光 聚合或微影蝕刻建立)的單元製成。該結構具有所需光柵 的形狀，提供所使用材料的光學常數。單元基板由啟用定 址液晶所需的一透明電極所組成。圖7顯示在結構之頂部 上的液晶材料的-額外平行層。應注意，額外平行層係只 供製造目的，且不會影塑氺與# 〇0一 个曰〜饗光學頃取早兀31之功能。此層 可省略。An invention discloses an optical reading for a multilayer optical record carrier. The optical reading unit includes a control unit configured to generate one of the light from the main spot, the first side spot, and the second second spot on the optical device. Searching for a signal, wherein the main spot, the young side spot, and the second side spot are formed by focusing a primary radiation beam, a first side radiation beam, and a second side radiation beam, respectively The effect of a background spot caused by the reflection of the main spot of the defocused layer of the multilayer optical record carrier is considered. The method of obtaining an accurate push-pull seek signal of the optical record carrier can be implemented using a computer program. [Embodiment] q A = record carrier 2 can be a multi-layer recordable (R) or rewritable (rw) class of 8 7 holes for storage or 5 have been recorded on the information track, such as DVD+RW, DVD- RW, DVD+R, HD_DVE^BD+RW. Referring to Figure 1, the emitter diode 3 2 a passes through *, the optical reading unit 30 has a radiation generator 31 (e.g., a lightning beam configured to generate a radiation beam 32a. The radiation beam blade is 33 and an objective lens 34. Objective lens 34 focuses radiation beam 32b 129947.doc 200849232 Focus F on optical record carrier 2. Radiation beam 32b is reflected from optical record carrier 2 (reflection (four) beam 32e) and passes through collimator lens and objective lens and beam splitter 33 (beam 32d), and through an astigmatic lens (for focusing " nucleus generation) to reach an optical detector 35. For achieving and maintaining a desired focus of the radiation beam 32b in the optical record carrier 2 Positionally, the objective lens 34 is axially replaceably mounted. 辐射 c Limits the amount of radiation incident on each of the limits. Referring to Figure 2, the optical detector 35 includes a plurality of detector segments (in four pre-tests) In the case of the segments 35a, 35b, 35c and 35d), which are capable of providing individual signals, A, B, and coffee, respectively, # are shown in the four detectors, the center line 37, the first and fourth regions. Segments 35a and 35d are separated from second and third sections 35b & 35c. In addition, optical detection The processor 35 includes two detector sections 35e & 35f that are capable of providing detectors h唬E and F indicating light incidence on each of the detector sections (i.e., 350 and 35f). The optical detector 35 includes two detector sections 35g and 35h' that are capable of providing individual detector signals η and η indicating light on each of the detector sections (ie, 35g and 35h) The amount of incident light. The push-pull method and the three-beam method are usually used as a search servo method for recording data on/from an optical record carrier. Among these methods, one is typical. The principle of the differential push-pull method is schematically illustrated in Fig. 3. The radiation beam generated by the radiation generator 31 passes through the optical member 39 (see Fig. ,) and is divided into a main Koda beam, a younger one. a side light beam and a second side radiation beam. The main radiation beam produces a primary spot Μ, the first side radiation beam produces a first side spot S], and the second side radiation beam produces a first spot on the optical record carrier 2 Two 129947.doc 200849232 Side spot S2. Three formed by optical reading 3 1 The radiation beam spot (the main spot Μ and the side spot 1 and so are positioned such that the side spot 8) and & are offset by the half track pitch P to the main spot 纟. 纟 Autonomous spot punctual spot ^ And the reflected radiation beam of both of § 2 is photoelectrically converted by the optical detector 35, so that the push-pull tracking signal can be obtained at the spots 8, 8] and 82. The photoelectric conversion signal ^ is used to obtain data and servo The signals required by the optical disc drive, such as radial, focal point and tilt control signals. For example, a data signal, a tracking signal, and the 'water focus error apostrophe are usually obtained using the following equation: (data = (A + B + C+D) Tracking WA+DHB+C^-I^e+ghf+h)], where k is the double factor, focus = (A+C)-(B+D) should be Zhuangsi, the main spot is This is considered to be the central spot or the main spot, and the side spot is considered to be a satellite spot or a sub spot or a secondary spot. In addition, the optical system 30 can be modified to form the main spot M and the side spots s 1 and S2. The inventors have found that for a two-layer or multi-layer optical record carrier, a loss of G 胄 occurs in a three-spot push-pull difficulty for radial seek. The inventors have also made some distortions not only due to coherent crosstalk (ie, interference with the first side spot and the second side spot of the defocus layer 'spot), and most of the change = appearing in defocused light Point itself. As is clear from Fig. 4, the reflected radiation beam from the main spot M and the first side spot h and the second side = S, 2 falls on the optical detector 35. It should also be noted that the overnight light is also formed by the reflection of the defocused layer of the optical record carrier 2. In addition, the reflected radiation beam from the rabbit spot is incident on all of the detector sections (ie 35a, ί c , 35c, 35d, 35e, 35f, 35g, and 3 5h). There is no 129947.doc 200849232 There are side light spots (ie, there is no \ and the measurement shows the side light spot 81 and the position of the signal detected on the & This is shown in Figures 5A and 5B. In Figure 5A, the horizontal axis represents the push-pull tracking signal value, and the vertical axis represents the amplitude of the push-pull seek signal having the first side spot and the second side spot. In Fig. 5B, the horizontal axis represents the push-pull seek signal value, and the vertical axis represents the amplitude of the push-pull seek signal without the first side spot and the second side spot. Observed from Fig. 5A and Fig. 5B The distortion amplitude of the push-pull tracking signal is very similar to the distortion without the presence of the side spot. Referring to the figure, the amplitude of the push-pull seek signal value is the change of the spot on the optical detector 35 reflected by the defocus layer. Therefore, the present invention discloses a radial tracking of information of a multilayer optical record carrier. The method includes generating a push-pull seek signal obtained from light of a primary spot, a first side spot, and a second side spot on an optical detector, wherein the main light The point, the first side spot and the second side spot are respectively formed by focusing a main radiation beam, a first side radiation beam and a C, a second side radiation beam, which are considered from the multilayer optical recording. The effect of a background spot caused by the reflection of the main spot of the defocused layer of the carrier. The push-pull tracking signal is generated in consideration of the variation of the background spot, thus producing a quasi-accurate push-pull tracking signal value. Essentially The method disclosed herein distinguishes the cause of distortion (i.e., background spot variation) in the three-spot push-pull seek signal from a side spot signal having a deductible beam landing. In a specific embodiment, the main spot is generated. The method of the push-pull tracking signal of the first side spot and the second side spot is included in the step illustrated in Fig. 6. Referring now to Fig. 6, in step 6〇2, the first side spot Si is generated ( Refer to Figure 3) and the first side of the 129947.doc 200849232 two-side spot S2 (refer to Figure 3) The first beam and the second side of the radiation beam are turned off. In step 604, the first signal associated with the background spot is measured by photoelectrically converting the reflected light beam from the background spot. In step 606, the first side radiation beam and the second side radiation beam of the first side of the c-seat (the reference point S) (refer to FIG. 3) and the second side spot S2 (refer to FIG. 3) are generated. In step 608, the disk background well point, the credit., the month is not particularly the side of the radiation beam, and the second signal associated with the second side radiation beam is converted from the background spot by photoelectric conversion: The side-light beam and the second-side light beam reflect the radiation beam and in step 610 the '-correction signal is calculated based on the difference between the first signal and the second signal. In step 612, 'the main spot, the first side spot, and the side, the side spot of the push-pull tracking signal are obtained by using the light from the main light and the second side spot. The photoelectric conversion (ie, the photoelectric signal) is generated by reflecting the correction signal on the radiation beam. The first side light is turned on and off: the second side light point is advantageous because there is no side light spot (ie, there is no first side light) The signal at the point and the second side spot is measurable and can be used as a measurement associated with the background spot. A signal with a side spot (ie having a first side light = and a second side spot) can be measured' And when (normal) push-pull in the three-spot, the signal '' is currently compensating for the beam to land. The push-pull tracking signal is obtained by considering the background spot variation, so the push-pull tracking signal is accurate. This improvement comes from optical recording. Recording/reproduction of the data of the carrier. In a further embodiment, turning the first side radiation beam and the second side radiation beam on and off comprises transmitting the main radiation beam through a switchable grating having the following states: a startup state, except the main In addition to the beam, this state produces a first side radiation beam and a second side radiation beam; '129947.doc 200849232 and - off state, which only transmits the main light beam. In other words, in the off state, the middle ' - The side radiating beam and the second side radiating beam are not transmitted. ^-Small and fairly simple optical components can be easily cited in the optical optical path. This is an advantageous embodiment of the 'Effective embodiment' and thus allows the remainder of the architecture with optical drivers A cost-effective solution with minimal variation. 〃 In still further embodiments, the switchable grating comprises one of a liquid crystal material and an acousto-optic modulator. The grating is made of a liquid crystal material as shown in FIG. The switching is achieved. The grating is made via a cell in the presence of a transparent structure, such as photopolymerization or photolithographic etching. The structure has the shape of the desired grating, providing the optical constant of the material used. The unit substrate is enabled by the addressed liquid crystal A transparent electrode is required. Figure 7 shows the extra parallel layer of liquid crystal material on top of the structure. It should be noted that the additional parallel layer is for manufacturing purposes only. Movies Shui plastic and without an 〇0 # ~ satisfy said optical functions are taken early 31's Wu This layer may be omitted.
C I考圖7 ’較佳地係’可切換液晶材料的該等折射率之 -者應匹配光柵的非可切換部分。開啟或關閉狀態然後對 應於繞射或無繞射，此係取決於是否使用具有正或負介電 各向異性的液晶。因此，藉由施加電壓至光柵，其開始或 仔止繞射。藉由連續施加高與低電壓(開啟與關閉），可個 別測量不具有側光點(即不具有第一側光點與第二側 的背景光點之信號與包括側光點（即具有第一側光點與第 二側光點）的背景光點之信號。 一簡單重建演算法係如下給定： 側光點信號（t=mT) =不具有側光點的信號 129947.doc 200849232 bm=側光點信號（t==l/2T+mT)=具有側光點的信號 C’用於背景光點之所校正的側光點信號外 其中m係整數且τ係完成關閉與開啟光柵循環所使用的時 間週期。 因此，新的三光點信號（即主光點、第—側光點與第二 側光點）係藉由使用光點開啟/關閉切換來取樣同相側光點 推挽尋軌信號而構成，其可產生計算出％的樣本^和^。 Cm由不具有背景光點的側光點推挽值組 光的推挽尋軌信號減去，以達到三光點信號γ’κ主 當光柵的切換係低於致動器的頻寬時，不連續取樣會影 響徑：尋軌性能。當切換係在致動器的頻寬内_，側：： ㈣尋軌信號的頻寬將減少。側光點信號係用來補償光束 著陸，其亦係一慢改變信號（此信號的來回頻率或第二、 第三諧波）。如此’只要切換時間超過補償光束著陸所需 的頻率係很好，此解決方案將可適當地工作。 Ο 此觀念在於藉由切換液晶材料，光將只遇到—相移且不 會偏極旋轉；此應藉由液晶單元的正確設計及其與進 極方向有關的方位而達成。 作為-呈現—實體結構之較佳光柵的替代方案，可 一光柵’#中整個單元係使用液晶填滿，但是用一 圖案化電極構造。應選擇該構造以實現啟用適當相移。對 ==立體結構的光栅及對於從液晶製成的光拇兩者 形：。/、建立的圖案係具有50%之負載循環的二元光柵 129947.doc -13· 200849232 側光點的強度一般應 1 /1 5階大小。 對於二元相位光柵而言，第零與第一階強度的強度係藉 由下式給定： 弟 〇階· 1()=½ [1+C0S((|))] Iin 弟 IP皆· ^=^2-2 cos((())]/(7i2) Iin 其中Iin係輻射光束的強度，且(Kphi)係二元光柵的相位深 度。 對於10之因數的強度差而言，相位深度差係波長的0.15。 對於15之因數的強度差而言，相位深度差係波長的〇12。 對於液晶材料而言，兩個狀態間的折射率差一般係01。 口此為了達成0·15λ的上述相位差，15人之液晶材料的深 度（對於藍光光碟而言（λ=4〇5 nm)，其係6〇8 之深度）係 適當的單元深度，並允許單元的快速切換。 可切換光栅亦可為一如圖8所示的聲光調變器。參考圖 8開始/關閉聲波產生光栅輪廓並將導致光栅的開啟及關 閉j本上’藉由開啟及關閉聲波，可開啟及關閉光柵。 可如月，】述關於液晶光栅的段落來實現側光點的處理。唯一 差別係-聲光調變器的切換時間可極短…至 大 /J\ 〇 4』在另一進—步具體實施例中’液晶材料包含鐵電液曰材 料。數個光柵可利用不同類型㈣… 戴電液曰曰材 型液曰日材不⑽型的液晶製成，例如使用向列 5^夜日日材科的一些材料及 相較於向列型，夜3播田 才料的其他材料。 a液曰曰’使用鐵電液晶材料的優點係相較於針 i29947.doc -J4- 200849232 對向列型液晶的5至（U ms，有 „ ,杳抓A 有、乃20叩切換時間的切換時 間差。實際的切換時間取決於 早7C間隙與細加的電場強 度0 f 參考圖卜考慮形成於多層光學記錄載體 (參考圖4)，該光學讀取單-經調適以執行產生主 弟一側光點與第二側光點之推挽尋軌信號的方法。為此目 的，該光學讀取單元30具有一控制單元38，其經配置以產 生一從落在-光學偵測器上之一主光點、一第一側光點盘 -弟一側先點之光取得之推挽尋軌信號，其令考慮因多層 光學記錄載體之離焦層之主光 ^ 王九點之反射引起之一背景光點 的效果，该主光點、該第一側光點舆該第二側光點分別係 藉由聚焦一主輻射弁蚩、—赞 .^ Λ| , 了尤末 弟一側輻射光束與一第二側輻 射光束形成。 該光學構件39(參考圖υ包含一可切換光柵，其配置用 ϋ 以關閉及開啟將第一側輻射光束與第二側輻射光束分別聚 焦至弟一側光點與第二側光點。 該控制單元3 8進一步包含· I) 測里單το 3 8a ’其配置用以當該可切換光栅係在開啟狀 態時，測量與該背景光點相關聯的一第一信號；及用以藉 由光私轉換來自5亥为景光點之反射輻射光束，當該可切換 光栅係在關閉狀態時，測量與背景光點相關聯的一第二信 號； 。 II) 片介單tl38b，其配置用以基於該第一信號與該第二 信號的差來計算一校正信號；及 129947.doc -15- 200849232 u/)邏輯早兀38c，其配置用以藉由將該校正信號施加在 來自該主絲、該第-側光點與該第二側絲的光電轉換 (即光電仏號）之反射輕射光束，I生主光點、第一側光點 與第二側光點的推挽尋執信號。 -驅動器(例如具有光學讀取單元3〇的藍光光碟驅動器 或:DVD驅動器或一狐DVD驅動器）可獲得準確的推挽尋 執^號，藉此改善資料的記錄/重製。 雖然本發明藉由使用藍光光碟與藍光驅動器的具體實施 例加以解釋’但是技術可應用至所有類型的多層記錄載 體，例如單次寫入媒體與多次寫入可記錄類型（DVD-RW、 口口 D + RW、HD-DVD)。此外，上述技術並未侷限於一雙層 己錄載體（即雙層兄錄載體）或一雙層雙側記錄載體 (即一雙層雙側記錄載體）。熟習此項技術者可使用軟體、 或使用硬體與軟體來實施產纟一推挽信號之方法的描述具 體實施例。彳文圖式、揭示内容及下列申請專利範圍的閱 貝實現本文所聲明申請專利範圍之熟諳此項技術者將可 ”解及貝現所揭示具體實施例的其他變化。動詞”包含，，的 使用亚未排除在申請專利範圍或描述中所述這些之外的元 牛存在。在元件或步驟前使用的不定冠詞，，一，，或”一個，，並 未排除複數個此等元件或步驟的存在。該等圖式及描述只 是說明而不是限制本發明。 【圖式簡單說明】 將藉由下列參考附圖的範例而進一步解說此等及其他態 樣特被與優點’圖中的相同參考數字指示相同或類似部 129947.doc -16- 200849232 件，而且其中： 圖1示意性說明一範例性光學讀取單元； 圖2示意性說明用於獲得徑向推挽尋軌信號之一範例性 光學偵測器； 圖3以一範例性差動推挽方法示意性說明在主光點、第 一側光點與第二側光點之間的位置關係；The reference to Fig. 7 'preferably' to switch the refractive indices of the liquid crystal material should match the non-switchable portion of the grating. The on or off state then corresponds to diffraction or no diffraction, depending on whether a liquid crystal having positive or negative dielectric anisotropy is used. Therefore, by applying a voltage to the grating, it starts or stops the diffraction. By continuously applying high and low voltages (on and off), it is possible to individually measure signals that do not have side spots (ie, do not have a first side spot and a second side of the background spot and include side spots (ie, have The signal of the background spot of one side spot and the second side spot. A simple reconstruction algorithm is given as follows: Side spot signal (t=mT) = signal without side spot 129947.doc 200849232 bm = side spot signal (t==l/2T+mT)=the signal C' with the side spot is used for the corrected side spot signal of the background spot, where m is an integer and the τ system is completed to close and turn on the grating The time period used by the cycle. Therefore, the new three-spot signal (ie, the main spot, the first-side spot, and the second-side spot) is sampled by the spot-side light-on/off switch to sample the in-phase side spot push-pull. Constructed by a tracking signal, which can generate samples of % and ^ calculated. Cm is subtracted from the push-pull tracking signal of the side-pick-picked group of light having no background spot to achieve the three-spot signal γ' When the switching of the κ main grating is lower than the bandwidth of the actuator, discontinuous sampling will affect the diameter: tracking When the switching system is within the bandwidth of the actuator, the side:: (4) The bandwidth of the tracking signal will be reduced. The side spot signal is used to compensate for the beam landing, which is also a slow change signal (the back and forth of this signal) Frequency or second and third harmonics. So 'as long as the switching time exceeds the frequency required for the compensation beam to land, this solution will work properly. Ο The idea is that by switching the liquid crystal material, the light will only Encounter-phase shift and no polar rotation; this should be achieved by the correct design of the liquid crystal cell and its orientation in relation to the direction of the pole. As an alternative to the preferred grating of the present-physical structure, a grating can be used. The entire cell in '# is filled with liquid crystal, but constructed with a patterned electrode. This configuration should be chosen to achieve proper phase shifting. For the == three-dimensional grating and for the optical thumb made from liquid crystal: /, The established pattern is a binary grating with a load cycle of 50%. 129947.doc -13· 200849232 The intensity of the side spot should generally be 1 / 1 5 steps. For the binary phase grating, the zeroth and the Strong first-order strength The degree is given by the following formula: 弟〇级·1()=1⁄2 [1+C0S((|))] Iin 弟 IP all · ^=^2-2 cos((())]/(7i2) Iin where Iin is the intensity of the radiation beam and (Kphi) is the phase depth of the binary grating. For the intensity difference of the factor of 10, the phase depth difference is 0.15 of the wavelength. For the intensity difference of the factor of 15, the phase Depth difference is the wavelength of 〇12. For liquid crystal materials, the refractive index difference between the two states is generally 01. In order to achieve the above phase difference of 0·15λ, the depth of the liquid crystal material of 15 people (for Blu-ray discs) Word (λ = 4 〇 5 nm), which is a depth of 6 〇 8 ) is the appropriate cell depth and allows fast switching of the cell. The switchable grating can also be an acousto-optic modulator as shown in FIG. Referring to Figure 8, starting/closing the acoustic wave produces a raster profile and will cause the grating to turn on and off. By turning the sound wave on and off, the grating can be turned on and off. The section on the liquid crystal grating can be described as a month to realize the processing of the side spot. The only difference is that the switching time of the acousto-optic modulator can be extremely short...to a large /J\ 〇 4" In another embodiment, the liquid crystal material comprises a ferroelectric liquid material. Several types of gratings can be used in different types (four)... Electrolytic liquid coffin type liquid helium is not made of liquid crystal (10) type, for example, using some materials of nematic 5^ night Japanese wood and compared to nematic, Night 3 broadcasts other materials that are only available. The advantage of using a ferroelectric liquid crystal material is 5 to (U ms, „, 杳 A, 20 叩 switching time compared to the needle i29947.doc -J4- 200849232 Switching time difference. The actual switching time depends on the early 7C gap and the finely applied electric field strength 0 f. Refer to the multilayer optical record carrier (refer to Figure 4), which is adapted to perform the generation of the master. A method of push-pull tracking signals between a side spot and a second side spot. For this purpose, the optical reading unit 30 has a control unit 38 configured to generate a slave-to-optical detector. A main spot, a first side spot plate, and a push-pull tracking signal obtained by the first point of the light, which is caused by reflection of the main light of the defocused layer of the multilayer optical record carrier The effect of one of the background spots, the main spot, the first side spot, and the second side spot are respectively focused by a main radiation 弁蚩, - 赞.^ Λ| The light beam is formed with a second side radiation beam. The optical member 39 (refer to FIG. a grid configured to close and open the first side radiation beam and the second side radiation beam respectively to the side light spot and the second side light spot. The control unit 38 further includes · I) Το 3 8a ' is configured to measure a first signal associated with the background spot when the switchable grating is in an on state; and to reflect from the 5H point by a light private conversion a radiation beam that, when the switchable grating is in the off state, measures a second signal associated with the background spot; II) a slice interface tl38b configured to be based on the first signal and the second signal Calculating a correction signal; and 129947.doc -15-200849232 u/) logic early 38c configured to apply the correction signal from the main wire, the first side spot, and the second The reflected light beam of the photoelectric conversion (ie, photoelectric nickname) of the side wire, the push-pull seek signal of the primary light spot, the first side spot and the second side spot. - The driver (for example, having an optical reading unit) 3-inch Blu-ray disc drive or: DVD drive or a fox DVD drive) Obtaining an accurate push-pull seek number, thereby improving the recording/reproduction of the data. Although the invention is explained by using a specific embodiment of a Blu-ray disc and a Blu-ray drive, the technology can be applied to all types of multi-layer record carriers, For example, single-write media and multiple-write recordable types (DVD-RW, port D + RW, HD-DVD). In addition, the above technology is not limited to a double-layered record carrier (ie, double-layered recordings) a carrier or a double-layered double-sided record carrier (ie, a double-layered double-sided record carrier). Description of the method by which the skilled artisan can use software, or use hardware and software to implement a push-pull push-pull signal. example. 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 The use of the bulls that are not excluded from the scope of the patent application or description described above is used. The use of the indefinite articles, <RTI ID=0.0> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects are indicated by the same reference numerals in the drawings, and the same reference numerals are used to indicate the same or similar parts 129947.doc -16 - 200849232, and wherein: Figure 1 An exemplary optical reading unit is schematically illustrated; FIG. 2 schematically illustrates an exemplary optical detector for obtaining a radial push-pull tracking signal; FIG. 3 is schematically illustrated by an exemplary differential push-pull method. a positional relationship between the main spot, the first side spot, and the second side spot;
圖4不意性說明在光學偵測器平面上的光強度分佈，其 =-背景光點連同主m側光點與第二側光點:、 該背景光點由一範例性多層藍光光碟的離焦層反射引起； 圖5A及圖5B以圖例說明具有側光點（即具有第—側光點 與第二側光點）及不具有側光點（即不具有第一側光點與第 二側光點）之推挽尋執信號的失真振幅； 圖6根據本發明的一具體實施例顯示產生推挽尋執信號 之方法； ~ 圖7示思性顯示一範例性液晶光栅；及 圖8示意性顯示一範例性聲光調變器。 【主要元件符號說明】 2 光學s己錄載體 30 光學讀取單元/光學系統 31 輻射產生器 32a 輻射光束 32b 輻射光束 32c 輻射光束 32d 輻射光束 129947.doc -17- 200849232 Γ ί. 33 分 光 器 34a 準 直 透 鏡 34b 物 鏡 35 光 學 偵 測 器 36 像散透 鏡 35a 偵 測 器 區 段/ 第 --- 段 35b 偵 測 器 區 段/ 第 二 段 35c 偵 測 器 區 段/ 第 三 區 段 35d 偵 測 器 段/ 第 四 區 段 35e 偵 測 器 區 段 35f 偵 測 器 區 段 35g 偵 測 器 區 段 35h 偵 測 器 區 段 37 中 線 38 控制單元 38a 測量單元 38b 計算單元 38c 邏輯單元 39 光學構件/可切換光橋 Μ 主光點 Si 第一側光點 S2 第二側光點 129947.doc -18-Figure 4 is a non-intentional description of the light intensity distribution on the plane of the optical detector, which = - background spot together with the main m side spot and the second side spot: the background spot is separated by an exemplary multilayer Blu-ray disc Coke layer reflection is caused; FIG. 5A and FIG. 5B illustrate with a side spot (ie, having a first side spot and a second side spot) and no side spot (ie, having no first side spot and second) Distortion amplitude of the push-pull seek signal of the side spot; FIG. 6 shows a method of generating a push-pull seek signal according to an embodiment of the invention; ~ FIG. 7 is an illustrative display of an exemplary liquid crystal grating; and FIG. An exemplary acousto-optic modulator is shown schematically. [Main component symbol description] 2 Optical s recording carrier 30 Optical reading unit / optical system 31 Radiation generator 32a Radiation beam 32b Radiation beam 32c Radiation beam 32d Radiation beam 129947.doc -17- 200849232 Γ ί. 33 Beam splitter 34a Collimating lens 34b Objective lens 35 Optical detector 36 Astigmatic lens 35a Detector section / Section - Segment 35b Detector section / Second section 35c Detector section / Third section 35d Detection Segment / fourth segment 35e detector segment 35f detector segment 35g detector segment 35h detector segment 37 center line 38 control unit 38a measurement unit 38b computing unit 38c logic unit 39 optical component / Switchable optical bridge Μ main spot Si first side spot S2 second side spot 129947.doc -18-