KR870000697Y1 - Focus servo circuit of optical reproducing device - Google Patents
Focus servo circuit of optical reproducing device Download PDFInfo
- Publication number
- KR870000697Y1 KR870000697Y1 KR2019840014606U KR840014606U KR870000697Y1 KR 870000697 Y1 KR870000697 Y1 KR 870000697Y1 KR 2019840014606 U KR2019840014606 U KR 2019840014606U KR 840014606 U KR840014606 U KR 840014606U KR 870000697 Y1 KR870000697 Y1 KR 870000697Y1
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- South Korea
- Prior art keywords
- output
- focus
- focus servo
- optical reproducing
- servo circuit
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Classifications
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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
-
- 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
- G11B7/0945—Methods for initialising servos, start-up sequences
Landscapes
- Optical Recording Or Reproduction (AREA)
Abstract
내용 없음.No content.
Description
제1도는 본 고안의 계통도.1 is a schematic diagram of the present invention.
제2도는 각 부분의 출력 파형도.2 is an output waveform diagram of each part.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
1 : 합산기 2,6 : 레벨검출기1: summer 2,6: level detector
4,5,11 : 증폭기 3 : 오어게이트4,5,11: amplifier 3: or gate
7 : 래치 10 : 발진기7: latch 10: oscillator
8,9 : 전자스위치8,9: electronic switch
본 고안은 3빔(beam)방식의 광 재생장치에서 광 픽-업(pick-up)의 옵젝티브 렌즈(objective Lens : 이하 Lens로 칭함)를 통해 나오는 빛이 신호가 수록되어 있는 레코드(Record) 매체에 정확한 촛점을 이루게 하기 위해 렌즈를 레코드와 수직으로 현재의 위치에서 일정속도로 움직여서 캡처링 레인지(capturing range)에 도달했을 때 이위치를 서치(Search)하여 포커스 서보 루우프(Focus Sevvo Loop)를 구동시키게 하는 회로이다.The present invention records a signal in which a signal of light emitted through an optical lens of an optical pick-up (hereinafter referred to as a lens) is recorded in a three-beam optical reproduction device. To ensure accurate focusing on the medium, the lens is moved perpendicular to the record at a constant speed from the current position to search for this position when the capturing range is reached and to focus the focus servo loop (Focus Sevvo Loop). It is a circuit for driving.
종래 회로의 복잡하고 많은 부품 사용에 비해 1개의 연산증폭기와 2개의 다이오드 및 트랜지스터로 제작이 가능하므로 원가절감에 유리한 회로로써 이를 첨부된 도면에 의거 상세히 설명하면 다음과 같다.Compared to the complicated and many components of the conventional circuit, one op amp, two diodes, and a transistor can be manufactured, and thus a circuit for advantageous cost reduction will be described in detail with reference to the accompanying drawings.
즉, 트랙킹 서보용 포토 다이오드 출력(A)에 합산기(1)를 거쳐 레벨 검출기(2)에 연결하고, 이를 오어게이트(3)의 일단 입력에 연결한다.That is, the photodiode output A for tracking servo is connected to the level detector 2 via an adder 1, and is connected to one end of the or gate 3.
또, 포커스 에러 단(B)에 증폭기(4,5)를 연결하고, 상기 연산 증폭기(4)의 일방은 레벨 검출기(6)를 거쳐 오어게이트(3) 타방에 연결하며, 이의 출력이 래치(7)를 거쳐 전자 스위치(8,9)를 제어 하도록 구성한다.In addition, the amplifiers 4 and 5 are connected to the focus error stage B, and one of the operational amplifiers 4 is connected to the other of the or gate 3 via the level detector 6, and its output is latched ( 7) to control the electronic switches (8, 9).
상기 전자 스위치(8)의 일방엔 발진기(10)를 연결하고, 전자스위치(9)는 증폭기(5,11)를 연결하며 증폭기(11)의 출력이 포커스 서보코일(L)을 제어하는 구성이다.The oscillator 10 is connected to one side of the electronic switch 8, the electronic switch 9 connects the amplifiers 5 and 11, and the output of the amplifier 11 controls the focus servo coil L. .
전원을 온하고 정상동작전 까지는 렌즈는 중력에 의해 가장 밑부분에 위치하게 되므로 e와 H점에는 아무런 파형도 나오지 않게 되며 이때 전자 스위치(8)는 접속되고 전자스위치(9)는 전자스위치(8) 일단에 접속되어 코일에는 제2(a)도와 같은 파형이 인가되며 이로인해 렌즈는 상하 운동을 시작하게 되어 제2(b)도와 같은 파형이 증폭기(4)를 거쳐 제2(a)도에 출력된다.Since the lens is positioned at the bottom by gravity due to the power on and normal operation, no waveform appears at points e and H. At this time, the electronic switch 8 is connected and the electronic switch 9 is the electronic switch 8 One end is connected to the coil and a waveform such as the second (a) is applied to the coil, which causes the lens to start up and down, and the waveform such as the second (b) is output through the amplifier 4 to the second (a). do.
이 파형의 레벨을 H와 같이 선정하여 표준 레벨과 비교함으로써 제2(c)도와 같은 파형이 b에 출력되고 래치(7)에 전달되며 이때의 출력은 d에 제2(d)도와 같이 나타난다.By selecting the level of the waveform as H and comparing it with the standard level, a waveform such as the second (c) diagram is output to b and transmitted to the latch 7, and the output at this time is shown as the second (d) diagram in d.
래치(7)의 입력이 바뀌므로 출력이 논리 Low에서 High로 돼변환되면 전자스위치(8,9)의 동작이 전과 반대로 됨에 따라 코일(L)에는 발진기(10)의 출력이 아닌 포커스 에러신호가 인가되어 포커스 서보 루우프(Focus Servo Loop)를 형성하게 되어 서보 동작이 진행된다.Since the input of the latch 7 is changed, when the output is changed from logic low to high, the operation of the electronic switches 8 and 9 is reversed as before, so that the focus error signal, not the output of the oscillator 10, is applied to the coil L. It is applied to form a focus servo loop, and the servo operation is performed.
포커스 캡쳐링 레인지(Range)에 내에 들어가게 되면 e에는 신호가 인가되고 합산기(1)에서 더해지므로 f에는 어떤 크기를 갖는 값을 유지하게 된다.Once within the focus capturing range, a signal is applied to e and added by summer 1 to maintain a value of f.
이 값은 캡쳐링이 되면 언제나 일정한 직류 전압을 계속 유지하게 되므로 이 값을 서치하여 어느 일정 값에 도달시 Low에서 High로 변환되므로 래치(7)에 계속해서 HIGH신호가 인가되므로 포커스 에러레벨이 작아지므로 해서 발생하는 래치(7)의 HIGH에서 LOW로 변환하는 것을 방지하게 된다.Since this value keeps constant DC voltage at all times when capturing, search this value and when it reaches a certain value, it is converted from low to high, so the HIGH signal is continuously applied to the latch (7), so the focus error level is small. Therefore, it is possible to prevent the shift of the latch 7 generated from high to low.
따라서 캡쳐링이 되었을시에 g의 파형은 제2(e)도와 같이 되므로 g와 b의 신호를 오어시키므로 해서 래치(7)의 출력 d에는 정상적인 포커스 서보가 이루어지게 되는 것이다.Therefore, when capturing is performed, the waveform of g becomes as shown in FIG. 2 (e), so that the signals d of g and b are turned off so that the normal focus servo is applied to the output d of the latch 7.
만일 캡쳐링이 안되게 되면 g의 파형은 LOW인 상태이고 레벨 검출기(2)의 기준 레벨이 정상적인 에러 레벨보다 높으므로 b의 파형도 LOW로 되어 p전원 온 시와 같은 상태로 되므로 전과 같은 동작을 반복하게 된다.If capturing fails, the waveform of g is LOW and the reference level of the level detector 2 is higher than the normal error level. Therefore, the waveform of b is also LOW and becomes the same as when the power is turned on. Done.
이러한 본 고안은 비교적 간단한 구성으로 이러한 회로의 제작이 가능하므로 신뢰성 향상과 원가절감을 이루게 되는 유익한 특징이 있는 것이다.This invention has a beneficial feature that can be produced in such a circuit with a relatively simple configuration to achieve improved reliability and cost savings.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019840014606U KR870000697Y1 (en) | 1984-12-31 | 1984-12-31 | Focus servo circuit of optical reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019840014606U KR870000697Y1 (en) | 1984-12-31 | 1984-12-31 | Focus servo circuit of optical reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR860008560U KR860008560U (en) | 1986-07-28 |
| KR870000697Y1 true KR870000697Y1 (en) | 1987-02-25 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR2019840014606U KR870000697Y1 (en) | 1984-12-31 | 1984-12-31 | Focus servo circuit of optical reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR870000697Y1 (en) |
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1984
- 1984-12-31 KR KR2019840014606U patent/KR870000697Y1/en not_active IP Right Cessation
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| Publication number | Publication date |
|---|---|
| KR860008560U (en) | 1986-07-28 |
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