CN1022518C - 聚焦控制电路 - Google Patents
聚焦控制电路 Download PDFInfo
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- CN1022518C CN1022518C CN90108670A CN90108670A CN1022518C CN 1022518 C CN1022518 C CN 1022518C CN 90108670 A CN90108670 A CN 90108670A CN 90108670 A CN90108670 A CN 90108670A CN 1022518 C CN1022518 C CN 1022518C
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- China
- Prior art keywords
- input end
- differential amplifier
- multiplier
- output terminal
- focus control
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/0908—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only
- G11B7/0909—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for focusing only by astigmatic methods
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/094—Methods and circuits for servo offset compensation
Landscapes
- Optical Recording Or Reproduction (AREA)
- Medicines Containing Material From Animals Or Micro-Organisms (AREA)
- Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
- Medicines Containing Plant Substances (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Looms (AREA)
- Lubrication Of Internal Combustion Engines (AREA)
- Eye Examination Apparatus (AREA)
- Details Of Television Scanning (AREA)
- Telescopes (AREA)
- Focusing (AREA)
- Automatic Focus Adjustment (AREA)
Abstract
在扫描信息介质上以某一频率扭摆的数据轨迹的光扫描装置上，扫描数据的光束被从信息介质上反射到装有4个光电二极管(A、B、C、D)的四象限光探测器(PD)上。为了自动地补偿在聚焦控制电路中诸如由温度变化造成的偏移电压，乘法器(M)的输入端加有聚焦和循迹控制信号。乘法器(M)的输出信号通过低通滤波器(TP)送入聚焦控制电路作为补偿电路。
Description
此发明涉及一种用于光扫描装置的聚焦控制电路，以此，光束可由一循迹控制电路引导，跟踪一唱片形信息介质上以某一中心频率扭摆的数据轨迹，并借助于该聚焦控制电路该光束会聚在该信息介质上从而使该光束从该信息介质上折射到一个四象限光探测器。
根据EP-A 0 256 984可知一种唱片形信息介质，其数据轨迹是以一中心频率扭摆的。因而该数据轨迹成正弦形。这种形状特殊的数据轨迹的优点在于它们可以包含附加的信息，例如位置信息。
在所谓的推挽方法中，光束例如在扫描这种信息介质上的数据时可由一聚焦控制电路会聚在效信息介质上，并由一循迹控制电路引导跟踪一条以预定频率扭摆的数据轨迹。扫描数据轨迹的光束被信息介质折射到一个由4个光电二极管A、B、C和D构成的四象限光探测器。4个光探测器A、B、C和D输出信号在一加法放大器中相加。为了产生循迹误差信号即用于循迹控制电路的控制信号，两个相邻设置的光电二极管A和B的输出信号被送入第一差分放大器的加法输入端，而另外两个相邻设置的光电二极管C和D的输出信号被送入第一差分放大器的减法输入端。用于聚焦控制电路的控制信号即所谓的聚焦误差信号，取自第二差分放大器的输出端，而其加法输入端被送入第一对两个对角设置的光电二极管A和C的输出信号，而另一对两个对角设置的光电二极管B和D的输出信号被送入第二差分放大器的减
法输入端。
为了补偿出现在光测探器和放大器中的无用的偏移电压，预先用电位器调整好的补偿电压被送入聚焦控制电路。
然而这种方法具有仍然忽视了诸如由元件老化或由于温度变化而造成的偏移电压变化的缺点。为了还能够补偿偏移电压的变化，补偿电压因而必须经常地用一电位器来调整。
因而此发明的目的就是在所述那种聚焦控制电路中自动地补偿偏移电压及其诸如由于元件老化或由温度变化所致的变化。
此发明通过将循迹误差信号送至一乘法器的第一输入並将聚焦误差信号输至该乘法器的第二输入端同时将该乘法器的输出信号经一低通滤波器送入聚焦控制电路作为补偿电压而达到了这个目的。
图1为此发明的第一个例子;
图2为乘法器的一个例子。
借助于图1所示的例子，此发明将得以描述和说明。
图1中所示四象限光探测器有4个光电二极管A、B、C和D。两个相邻设置的光电二极管A和B的输出信号被送至差分放大器V1的加法输入端，而另两个相邻设置的光电二极管C和D的输出信号与差分放大器V1的减法输入端连接。两个对角设置光电二极管A和C的输出信号被送至差分放大器V2的加法输入端，而另两个对角设置的光电二极管B和D与差分放大器V2的减法输入端连接。两个差分放大器V1和V2的输出端都通过滤波器F和相移器PH各自与乘法器M的两个输入端连接，而后者的输出端通过低通滤波器TP和放大器V3与求和点SU的一个输入端连接。在求和点SU的另一输入端处接差分放大器V2的输出端。加有已经补偿的聚焦误差信号的求和点
SU的输出端与聚焦控制电路的控制放大器V4连接。
此发明源于这样的认识：在差分放大器V1输出端处的循迹误差信号中包含有介质上数据轨迹扭摆的频率。
通常宽度与信息介质上数据轨迹的扭摆频率相应的滤波器F和相移器PH对此发明的效能不是绝对必需的，但它们可以改善偏移电压的补偿。
放大器V3输出端处的信号被送入聚焦控制电路作为偏移补偿电压。因而所有偏移电压及其在光探测器PD和放大器V1及V2中诸如由元件老化成由温度变化而造成的变化得以补偿。
图2表示乘法器M的一个例子。
乘法器M的加有加法放大器V2的输出信号的一个输出端E1构成了两个联动的可控转换开关U1和U2的相互连接的第一输出端，它们的第二输入端处于参考电位。乘法器M的加有差分放大器V1输出端处的循迹误差信号的第二输入端E2构成了其输出端与两个转换开关U1和U2的控制输入端相连的比较器K或限幅器的输入端。转换开关U1的输出端通过电阻R1与差分放大器DV的反向输入端相连。另一转换开关U2的输出端通过电阻R2与差分放大器DV的通过处于参考电位的电容C2的非反向输入端相连。构成乘法器M的输出端A1的差分放大器DV输出端通过电容C1反馈至反向输入端。
比较器K将差分放大器V1输出端处的正弦形扭摆数据轨迹信号转换成矩形信号。两可控转换开关U1和U2因而由比较器K以差分放大器V1输出端处的正弦形信号的频率来转换。差分放大器DV根据两个转换开关U1和U2的位置来在一个或另一个方向上对加法放大器V2输出端处的信号进行积分。
此发明适合作为扫描其数据轨迹以某一频率扭摆的光信息介质的光扫描装置的聚焦控制电路。
Claims (5)
1、光扫描装置的聚焦控制电路，由此，光束由一循迹调整电路引导跟踪唱片形记录介质上以某一中心频率扭摆的数据轨迹，由聚焦调整电路会聚在记录介质上，光束从记录介质反射到一四象限光探测器(PD)上，循迹误差信号和聚焦误差信号分别被送到乘法器(M)的第一和第二输入端以产生一偏移补偿电压，其特征在于：乘法器(M)的输出信号作为补偿电压通过一低通滤波器(TP)送入聚焦调整电路。
2、权利要求1所述聚焦控制电路，其特征在于光探测器（PD）的两个相邻设置的光电二极管（A、B）的输出信号被送入第一差分放大器（V1）的加法输入端，而另两个相邻设置的光电二极管（C、D）的输出信号被送至第一差分放大器（V1）的减法输入端，循迹误差信号可取自后者的输出端，第一对对角设置的光电二极管（A、C）的输出信号被送至第二差分放大器的加法输入端，而另两个对角设置的一对光电二极管（BD）的输出信号被送至第二差分放大器（V2）的减法输入端，聚焦误差信号可取自后者的输出端，第一差分放大器（V1）的输出端与乘法器（M）的第一输入端连接，第二差分放大器（V2）的输出端与乘法器（M）的第二输入端及求和点（SU）的第一输入端连接，而低通滤波器（TP）的输出端与求和点（SU）的第二输入端连接，用于聚焦控制电路的控制信号可取自后者的输出端。
3、权利要求1或2所述聚焦控制电路，其特征在于如同在第一差分放大器（V1）与乘法器（M）之间那样在第二差分放大器（V2）与乘法器（M）之间也装有滤波器（F）。
4、权利要求1、2或3所述聚焦控制电路，其特征在于在放大器（V1、V2）之一与乘法器（M）连接的至少一条支路上装有相移器（PH）。
5、权利要求1、2、3或4所述聚焦控制电路，其特征在于第一和第二可控转换开关（U1、U2）的相互连接的第一输入端构成乘法器（M）的加有第二差分放大器（V2）输出信号的第一输入端（E1），两个可控制开关（U1、U2）的第二输入端处于参考电位，输出端与两个转换开关（U1、U2）的控制输入端连接的比较器或限幅器（K）的输入端构成乘法器（M）的第二输入端，第一转换开关（U1）的输出端通过第一电阻（R1）与第三差分放大器（DV）的反向输入端连接，第二转换开关（U2）的输出端通过第二电阻（R2）与第三差分放大器（DV）通过第一电容（C2）处于参考电位的非反向输入端连接，构成乘法器（M）的输出端（A1）的第三差分放大器（DV）的输出端通过第二电容（C1）反馈至反向输入端。
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3936032.6 | 1989-10-28 | ||
| DEP3936032.6 | 1989-10-28 | ||
| DE3936032A DE3936032A1 (de) | 1989-10-28 | 1989-10-28 | Fokusregelkreis |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1051444A CN1051444A (zh) | 1991-05-15 |
| CN1022518C true CN1022518C (zh) | 1993-10-20 |
Family
ID=6392483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN90108670A Expired - Fee Related CN1022518C (zh) | 1989-10-28 | 1990-10-27 | 聚焦控制电路 |
Country Status (14)
| Country | Link |
|---|---|
| EP (1) | EP0500547B1 (zh) |
| JP (1) | JP2930715B2 (zh) |
| KR (1) | KR100251289B1 (zh) |
| CN (1) | CN1022518C (zh) |
| AT (1) | ATE114381T1 (zh) |
| AU (1) | AU6405190A (zh) |
| DE (2) | DE3936032A1 (zh) |
| ES (1) | ES2064763T3 (zh) |
| FI (1) | FI921879A0 (zh) |
| HK (1) | HK68795A (zh) |
| HU (1) | HU208588B (zh) |
| MY (1) | MY107278A (zh) |
| TR (1) | TR24658A (zh) |
| WO (1) | WO1991006949A1 (zh) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5978329A (en) * | 1995-06-07 | 1999-11-02 | Discovision Associates | Technique for closed loop servo operation in optical disc tracking control |
| WO2002093568A1 (fr) * | 2001-05-11 | 2002-11-21 | Matsushita Electric Industrial Co., Ltd. | Tete optique, enregistreur-lecteur de disque, et procede de pilotage d'un objectif |
| DE102005018461A1 (de) | 2005-04-20 | 2006-10-26 | Deutsche Thomson-Brandt Gmbh | Fokusregelung für optischen Abtaster |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6070923U (ja) * | 1983-10-19 | 1985-05-20 | パイオニア株式会社 | 焦点誤差検出装置 |
| JPS61269241A (ja) * | 1985-05-24 | 1986-11-28 | Sony Corp | 光学ヘツド用焦点検出装置 |
-
1989
- 1989-10-28 DE DE3936032A patent/DE3936032A1/de not_active Withdrawn
-
1990
- 1990-09-21 WO PCT/EP1990/001603 patent/WO1991006949A1/de active IP Right Grant
- 1990-09-21 DE DE59007781T patent/DE59007781D1/de not_active Expired - Fee Related
- 1990-09-21 JP JP2512856A patent/JP2930715B2/ja not_active Expired - Fee Related
- 1990-09-21 EP EP90913816A patent/EP0500547B1/de not_active Expired - Lifetime
- 1990-09-21 ES ES90913816T patent/ES2064763T3/es not_active Expired - Lifetime
- 1990-09-21 KR KR1019920700988A patent/KR100251289B1/ko not_active IP Right Cessation
- 1990-09-21 AT AT90913816T patent/ATE114381T1/de active
- 1990-09-21 AU AU64051/90A patent/AU6405190A/en not_active Abandoned
- 1990-09-21 HU HU921300A patent/HU208588B/hu not_active IP Right Cessation
- 1990-10-23 MY MYPI90001852A patent/MY107278A/en unknown
- 1990-10-26 TR TR90/1013A patent/TR24658A/xx unknown
- 1990-10-27 CN CN90108670A patent/CN1022518C/zh not_active Expired - Fee Related
-
1992
- 1992-04-27 FI FI921879A patent/FI921879A0/fi not_active Application Discontinuation
-
1995
- 1995-05-04 HK HK68795A patent/HK68795A/xx not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR920704282A (ko) | 1992-12-19 |
| EP0500547A1 (de) | 1992-09-02 |
| JPH05501327A (ja) | 1993-03-11 |
| HU208588B (en) | 1993-11-29 |
| TR24658A (tr) | 1992-03-01 |
| HU9201300D0 (en) | 1992-07-28 |
| CN1051444A (zh) | 1991-05-15 |
| DE3936032A1 (de) | 1991-05-02 |
| AU6405190A (en) | 1991-05-31 |
| FI921879A (fi) | 1992-04-27 |
| DE59007781D1 (de) | 1995-01-05 |
| MY107278A (en) | 1995-10-31 |
| KR100251289B1 (ko) | 2000-04-15 |
| EP0500547B1 (de) | 1994-11-23 |
| FI921879A0 (fi) | 1992-04-27 |
| ATE114381T1 (de) | 1994-12-15 |
| ES2064763T3 (es) | 1995-02-01 |
| HUT60874A (en) | 1992-10-28 |
| HK68795A (en) | 1995-05-12 |
| WO1991006949A1 (de) | 1991-05-16 |
| JP2930715B2 (ja) | 1999-08-03 |
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| C06 | Publication | ||
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| C14 | Grant of patent or utility model | ||
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| C15 | Extension of patent right duration from 15 to 20 years for appl. with date before 31.12.1992 and still valid on 11.12.2001 (patent law change 1993) | ||
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| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |