JPS63271731A - Focus control method for optical head - Google Patents
Focus control method for optical headInfo
- Publication number
- JPS63271731A JPS63271731A JP10430087A JP10430087A JPS63271731A JP S63271731 A JPS63271731 A JP S63271731A JP 10430087 A JP10430087 A JP 10430087A JP 10430087 A JP10430087 A JP 10430087A JP S63271731 A JPS63271731 A JP S63271731A
- Authority
- JP
- Japan
- Prior art keywords
- refractive index
- medium
- light beam
- light
- objective lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 25
- 238000000034 method Methods 0.000 title claims description 7
- 230000005684 electric field Effects 0.000 abstract description 4
- 239000004065 semiconductor Substances 0.000 abstract description 2
- 230000002093 peripheral effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000010897 surface acoustic wave method Methods 0.000 description 1
Landscapes
- Optical Recording Or Reproduction (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光ディスクやカード等の光メモリの光学ヘッド
に係り、特に集積化等ヘッドの小形化に適する光ヘッド
の焦点制御方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical head for an optical memory such as an optical disk or a card, and more particularly to a focus control method for an optical head suitable for miniaturization of the head such as integration.
光デイスクメモリ用の従来の光ヘッドには、日立評論、
６５巻１０号（１９８３年）第２９頁から第３４頁に論
じられているように、光ディスクへ照射する光が記録膜
上に焦点を結ぶための対物レンズ駆動用２次元あるいは
３次元アクチュエータが設置されていた。Conventional optical heads for optical disk memory include Hitachi Hyoron,
As discussed in Vol. 65, No. 10 (1983), pages 29 to 34, a two-dimensional or three-dimensional actuator is installed to drive the objective lens to focus the light irradiated onto the optical disk onto the recording film. It had been.
上記アクチュエータは、スパイラルバネや鏡筒等で構成
されるため、光ヘツド小形化の大きな障害となっていた
。Since the actuator is composed of a spiral spring, a lens barrel, etc., it has been a major obstacle to downsizing the optical head.
本発明の目的は、かかるアクチュエータを不要′にする
光ヘッドの焦点制御方法を提供することにある。An object of the present invention is to provide a focus control method for an optical head that eliminates the need for such an actuator.
上記目的は、光メモリ媒体上に光を集光するための集光
レンズに入る光の入射角を変える手段を持つことにより
、達成される。The above object is achieved by having means for varying the angle of incidence of light entering a condensing lens for concentrating light onto an optical memory medium.
レーザ出射後の拡散光路中に屈折率が変るレンズを設け
るとレンズからの出射角が変り、集光レンズに入る入射
角が変るので、光の焦点位置を変えることができる。し
かも、従来のアクチュエータのような機械的可動部が存
在しないため、装置の小形化が容易になるという特徴を
持っている。If a lens with a variable refractive index is provided in the diffused optical path after laser emission, the angle of emission from the lens changes and the angle of incidence of the light into the condenser lens changes, so the focal position of the light can be changed. Furthermore, since there are no mechanically movable parts like in conventional actuators, the device can be easily miniaturized.
以下、本発明の実施例を図面を用いて説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図において、半導体レーザ等の光源１と光メモリ媒
体５との間にハーフミラ−２，屈折率可変媒体３．対物
レンズ４を配置する。屈折率可変媒体は電界、磁界、温
度あるいは圧力等により媒体の屈折率を変化させ、光の
出射角度を変えることができる。屈折率可変媒体３の屈
折率をまわりの雰囲気と同様にした場合、光源からの光
は光路９を通ってスポット１１を結ぶことになる。また
屈折率を雰囲気中よりも大きくした場合、光は光路８で
示される方向へ曲げられスポット１０を結ぶ。従って、
屈折率可変媒体３の屈折率を変化させることにより、焦
点位置を移動することができる。In FIG. 1, a half mirror 2, a refractive index variable medium 3. The objective lens 4 is placed. A refractive index variable medium can change the refractive index of the medium by an electric field, a magnetic field, temperature, pressure, etc., and can change the light emission angle. When the refractive index of the variable refractive index medium 3 is set to be the same as that of the surrounding atmosphere, the light from the light source passes through the optical path 9 and connects the spots 11. Further, when the refractive index is made larger than that in the atmosphere, the light is bent in the direction shown by the optical path 8 and connects the spot 10. Therefore,
By changing the refractive index of the variable refractive index medium 3, the focal position can be moved.
焦点位置のずれはハーフミラ−２，シリンドリカルレン
ズ６、焦点位置検出センサ７で構成される光学系で検出
する。A shift in the focal position is detected by an optical system composed of a half mirror 2, a cylindrical lens 6, and a focal position detection sensor 7.
第１図中、屈折率可変媒体３は電気信号により屈折率を
変化させることができ、焦点位置検出センサ７で検出し
た焦点ずれ信号を電気信号とじてフィードバックするこ
とにより自動焦点機構を構成している。In FIG. 1, the refractive index variable medium 3 can change the refractive index by an electric signal, and constitutes an automatic focusing mechanism by feeding back the defocus signal detected by the focal position detection sensor 7 as an electric signal. There is.
第２図及び第３図は屈折率可変媒体を薄膜光導波路型ヘ
ッドに応用した例である。FIGS. 2 and 3 are examples in which a refractive index variable medium is applied to a thin film optical waveguide type head.
基板３０．導波路２８により構成される先導波路２１に
おいて、半導体レーザ等の光源１から出た光は、屈折率
可変媒体３及び光路３４を通リグレーティングレンズ２
７により集光され、光スポット３３を形成する。Substrate 30. In the leading waveguide 21 constituted by the waveguide 28, light emitted from the light source 1 such as a semiconductor laser passes through the refractive index variable medium 3 and the optical path 34 to the rerating lens 2.
7 to form a light spot 33.
この時、屈折率可変媒体３の屈折率を大きくすると、斜
めに入射した光は内側に曲げられ、光路３５を通る。従
って、グレーティングレンズ２７を通過した後の光スポ
ットは符号３２で示される点に結像し、焦点位置が移動
する。At this time, when the refractive index of the variable refractive index medium 3 is increased, the obliquely incident light is bent inward and passes through the optical path 35. Therefore, the light spot after passing through the grating lens 27 forms an image at a point indicated by the reference numeral 32, and the focal position moves.
屈折率可変媒体３は、電界、磁界、温度、圧力等あるい
は表面弾性波による効果でその屈折率を変化させること
ができ、外部から電気信号でコントロール可能である。The refractive index variable medium 3 can change its refractive index by an effect of an electric field, a magnetic field, temperature, pressure, etc. or a surface acoustic wave, and can be controlled from the outside by an electric signal.
第２図及び第３図中の屈折率可変媒体３は上下を電極２
９．３１ではさまれ、電圧印加により発生する電界の効
果で、その部分の屈折率を変化させる。The refractive index variable medium 3 in FIGS. 2 and 3 has electrodes 2 on its upper and lower sides.
9.31, and the refractive index of that portion changes due to the effect of the electric field generated by applying a voltage.
焦点位置のずれはハーフミラ−２，シリンドリカルレン
ズ６、焦点ずれ検出センサ７により検出され、電気信号
として前述の屈折率可変媒体３ヘフイードバツクされる
。これらの機構により常に合焦点位置を追従しつる自動
焦点機構が構成される。The focal position shift is detected by the half mirror 2, the cylindrical lens 6, and the focal shift detection sensor 7, and is fed back to the variable refractive index medium 3 as an electrical signal. These mechanisms constitute an automatic focusing mechanism that always follows the in-focus position.
本発明によれば、機械的な焦点位置駆動方式をまったく
必要としないので、振動に強く、高速応答の自動焦点調
整機構を実現することができる。According to the present invention, since no mechanical focus position driving method is required, it is possible to realize an automatic focus adjustment mechanism that is resistant to vibration and has a high speed response.
第１図は本発明の一実施例によるバルク型の焦点調節方
式を示した概略構成図、第２図及び第３図は本発明の他
の実施例として薄膜導波路型の光学ヘッドを示した概略
構成図である。
１・・・光源、２・・・ハーフミラ−１３・・・屈折率
可変媒体、４・・・対物レンズ、５川光メモリ媒体。
第 ｌ 図
２・・・ハーフミラーFIG. 1 is a schematic configuration diagram showing a bulk type focusing method according to one embodiment of the present invention, and FIGS. 2 and 3 show a thin film waveguide type optical head as other embodiments of the present invention. It is a schematic configuration diagram. DESCRIPTION OF SYMBOLS 1...Light source, 2...Half mirror 13...Refractive index variable medium, 4...Objective lens, 5-channel optical memory medium. Figure 2: Half mirror
Claims (1)
成される光ヘッドの焦点制御方法において、該対物レン
ズに入る光の入射角を変えることにより焦点位置を制御
することを特徴とする自動焦点制御方法。1. A method for controlling the focus of an optical head comprising a light source and an objective lens condensing light onto an optical memory medium, characterized in that the focus position is controlled by changing the incident angle of light entering the objective lens. Control method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10430087A JPS63271731A (en) | 1987-04-30 | 1987-04-30 | Focus control method for optical head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10430087A JPS63271731A (en) | 1987-04-30 | 1987-04-30 | Focus control method for optical head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63271731A true JPS63271731A (en) | 1988-11-09 |
Family
ID=14377073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10430087A Pending JPS63271731A (en) | 1987-04-30 | 1987-04-30 | Focus control method for optical head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63271731A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8022332B2 (en) * | 2004-04-28 | 2011-09-20 | Olympus Corporation | Laser processing device |
-
1987
- 1987-04-30 JP JP10430087A patent/JPS63271731A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8022332B2 (en) * | 2004-04-28 | 2011-09-20 | Olympus Corporation | Laser processing device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5450237A (en) | Hyperresolution optical system | |
| US6002661A (en) | Deformable mirror and optical data reproducing apparatus using the same | |
| KR0147628B1 (en) | Optical pickup for multi-layer disk | |
| US4763134A (en) | Laser recording apparatus having variable recording magnification and beam intensity control | |
| JPH11259889A (en) | Device for reading out/writing optical recording medium | |
| JPH01273228A (en) | Optical pickup device | |
| JPS63271731A (en) | Focus control method for optical head | |
| JPS63271732A (en) | Optical head | |
| JPS6057308A (en) | Focus position control mechanism of lens | |
| JP2941997B2 (en) | Semiconductor laser device and optical pickup device using this semiconductor laser device | |
| JPS63163312A (en) | Automatic focusing device and its lens driving mechanism | |
| JPS6232532B2 (en) | ||
| KR960035483A (en) | Optical pickup device with dual focusing | |
| JPS6041536Y2 (en) | optical scanning device | |
| JP2761300B2 (en) | Tracking actuator for optical disk drive | |
| JPS5826332A (en) | Adjusting device for optical path | |
| JPH0725859Y2 (en) | Mirror actuator for focus position control | |
| JPS63224036A (en) | Optical head | |
| JP2004079117A (en) | Information recording and reproducing device | |
| JPS63181131A (en) | Optical head | |
| JPH01113925A (en) | Optical pick-up | |
| JPH0547010A (en) | Method and device for adjusting focus position | |
| US20040021919A1 (en) | Focal adjustable hologram lens and optical apparatus using the same | |
| JPS63115130A (en) | Optical device | |
| JPH0366037A (en) | Light scanning record device |