JPS62192939A - Optical head - Google Patents
Optical headInfo
- Publication number
- JPS62192939A JPS62192939A JP61035820A JP3582086A JPS62192939A JP S62192939 A JPS62192939 A JP S62192939A JP 61035820 A JP61035820 A JP 61035820A JP 3582086 A JP3582086 A JP 3582086A JP S62192939 A JPS62192939 A JP S62192939A
- Authority
- JP
- Japan
- Prior art keywords
- light
- objective lens
- laser beam
- recording
- converging
- 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 42
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
Landscapes
- Optical Head (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光デイスク装置に関し、特に光ヘッドに関する
。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disk device, and particularly to an optical head.
従来、この種の光ヘッドは第２図に示すように、レーザ
ビーム発生器２１から発生した平行な光ビームはそのま
ま対物レンズ２２に入射するため、対物レンズ２２から
出射した光はただ１つの収束点をもつ。２３はハーフミ
ラ−１２４は収束レンズ、２５はナイフェツジ、２６は
２分割光検出器である。Conventionally, in this type of optical head, as shown in FIG. 2, the parallel light beam generated from the laser beam generator 21 enters the objective lens 22 as it is, so the light emitted from the objective lens 22 has only one convergent beam. Has a point. 23 is a half mirror, 124 is a converging lens, 25 is a knife lens, and 26 is a two-split photodetector.
上述した従来の光ヘッドは対物レンズから出射した光は
ただ１つの収束点しかないため、１つの光ヘッドで同時
に光デイスク媒体２７の異った記録面２７ａ、２７ａの
情報を同時に記録再生を行なうことはできない。Since the conventional optical head described above has only one convergence point for the light emitted from the objective lens, one optical head simultaneously records and reproduces information on different recording surfaces 27a and 27a of the optical disk medium 27. It is not possible.
本発明の目的は１つの光ヘッドによる光デイスク媒体の
異なる記録面への同時記録再生を可能ならしめた光ヘッ
ドを捉供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide an optical head that enables simultaneous recording and reproduction on different recording surfaces of an optical disk medium using one optical head.
ｃ問題点を解決するための手段〕
本発明の光ヘッドはレーザビーム発生器とレーザビーム
光軸上の対物レンズとの間に、対物レンズの出射光ビー
ムに複数の収束点を形成するフレネル帯板を設置したこ
とを特徴とするものである。Means for Solving Problem c] The optical head of the present invention has a Fresnel zone between the laser beam generator and the objective lens on the laser beam optical axis, which forms a plurality of convergence points in the light beam emitted from the objective lens. It is characterized by the installation of a board.
以下、本発明の一実施例を図により説明する。 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
第１図において、レーザビーム発生器１よりのレーザビ
ーム光軸上にはフレネル帯板２とハーフミラ−３と対物
レンズ４とを順に設置する。またハーフミラ−３の光軸
上には収束レンズ、ミラーナイフェツジ６．２分割光検
出器７ａ、”ｒｂを設置する。In FIG. 1, a Fresnel strip 2, a half mirror 3, and an objective lens 4 are installed in this order on the optical axis of a laser beam from a laser beam generator 1. Further, on the optical axis of the half mirror 3, a converging lens, a mirror knife 6, and a two-split photodetector 7a, ``rb'' are installed.
実施例において、レーザビー１、発生器１がら出射した
レーザビームＣはフレネル帯板２を通り、同一の光軸を
もつ透過しただけの平行光となる第１の光ビームａと回
折により収束光となる第２の光ビームｂの同一光軸上の
２つのレーザビー１、に分けられ、ハーフミラ−３を通
過し、対物レンズ４に入射する。対物レンズ４を通過し
た２つのレーザビームａ、ｂは対物レンズ４により同一
光軸−ヒに２つの収束点を作る収束光となる。In the embodiment, a laser beam C emitted from a laser beam 1 and a generator 1 passes through a Fresnel band plate 2, and is converted into a convergent light beam by diffraction with a first light beam a which is a parallel light beam having the same optical axis. The second light beam b is divided into two laser beams 1 on the same optical axis, passes through a half mirror 3, and enters an objective lens 4. The two laser beams a and b that have passed through the objective lens 4 become convergent light that forms two convergence points on the same optical axis.
２一つの収束光のうら、第１の収束光ａは両面型光ディ
スク媒体８の第１の記録面８ａに入射しスポットを結び
、第２の収束光すは両面型光ディスク媒体８の第２の記
録面８ｂに入射しスボソ１〜を結び、独立して記録再生
を行なう。2. Behind one convergent light, the first convergent light a enters the first recording surface 8a of the double-sided optical disc medium 8 and connects the spots, and the second convergent light a enters the first recording surface 8a of the double-sided optical disc medium 8, and the second convergent light a enters the second recording surface 8a of the double-sided optical disc medium 8. The light enters the recording surface 8b and connects the channels 1 to 1 to perform recording and reproduction independently.
多層型光デイスク媒体８の２つの面８ａ、８ｂがら反射
した２つのレーザ光は再び対物レンズ４に入射し、ハー
フミラ−３により光路を変えられ、フォーカス信号検出
用の収束レンズ５に入射し、ミラーナイフェツジ６によ
りビーム直径で分割される。分割された−・方のビーム
Ａの第１の記録面８ａから反射された光ビ・−１、の収
束点付近に第１の２分割光検出器７ａをおき、他方のビ
ーＪ、■３の第２の記録面８ｂから反射された光ビーＪ
４の収束点イ・１近に第２の２分割光検出器７ｂをおく
。第１の２分割光検出器７ａの出力は多層型光デイスク
媒体８の第１の記録面８ａ上にスボソＩ・を結ぶための
フォーカス信号を検出し、例えば対物レンズ４をト下さ
せ、フォーカス制御をする。第２の２分割光検出器７ｂ
の出力は両面型光ディスク媒体８の第２の記録面８ｂ上
にスポットを結ぶためのフォ・−カス信号を検出し、例
えばフレネル帯板２を−１−下させ、フォーカス制御を
行なう。The two laser beams reflected from the two surfaces 8a and 8b of the multilayer optical disk medium 8 enter the objective lens 4 again, have their optical paths changed by the half mirror 3, and enter the converging lens 5 for focus signal detection. The beam is divided by the beam diameter by a mirror knife 6. A first two-split photodetector 7a is placed near the convergence point of the light beam B-1 reflected from the first recording surface 8a of the divided beam A, and the other beam J, -3 is The light beam J reflected from the second recording surface 8b of
A second two-split photodetector 7b is placed near the convergence point A.4. The output of the first two-split photodetector 7a detects a focus signal for connecting a sub-I. Take control. Second two-split photodetector 7b
The output detects a focus signal for connecting a spot on the second recording surface 8b of the double-sided optical disc medium 8, and for example lowers the Fresnel strip 2 by -1- to perform focus control.
以上のような光ディスクを用いることにより、多層型光
ディスク８の複数面の情報が１つの光ヘッドで同時に記
録再生できる。なお、上記多層型光ディスクの代わりに
基板入射型の両面型光ディスクについても同時に記録再
生を行なうことができる。By using the optical disc as described above, information on multiple sides of the multilayer optical disc 8 can be simultaneously recorded and reproduced with one optical head. Incidentally, instead of the above-mentioned multilayer optical disk, recording and reproduction can also be performed simultaneously on a substrate-incident double-sided optical disk.
以上のように本発明の光ヘッドはレーザビーム発生器と
、対物レンズの間にフレネル帯板を入れ、対物レンズｉ
ｍ過後、複数の収束点を形成することにより、多層型光
ディスクの各面の情報を同時に記録、再生を行なうこと
ができる。また、両面型光ディスク媒体の場合、うらが
えずことなく、１つの光ヘッドで同時にＡＢ面を記録再
生することができる効果を有するものである。As described above, in the optical head of the present invention, a Fresnel strip plate is inserted between the laser beam generator and the objective lens, and the objective lens i
By forming a plurality of convergence points after m has elapsed, information on each side of the multilayer optical disc can be simultaneously recorded and reproduced. In addition, in the case of a double-sided optical disc medium, it has the effect of being able to record and reproduce information on the A and B sides at the same time with one optical head without any backtracking.
第１図は本発明の光ヘッドを示す構成図、第２図は従来
の光ヘッドを示す構成図である。
１・・・レーザビーム発生器、２・・・フレネル帯板、
３・・・ハーフミラ−１４・・・対物レンズ、５・・・
収束レンズ、６・・・ミラーナイフェツジ、７ａ、７ｂ
・・・２分割光検出器、８・・・多層型光デイスク媒体
、８ａ、８ｂ・・・光デイスク媒体記録面。FIG. 1 is a block diagram showing an optical head of the present invention, and FIG. 2 is a block diagram showing a conventional optical head. 1... Laser beam generator, 2... Fresnel strip plate,
3...half mirror 14...objective lens, 5...
Converging lens, 6... Mirror knife, 7a, 7b
...Two-split photodetector, 8...Multilayer optical disk medium, 8a, 8b... Optical disk medium recording surface.
Claims (1)
レンズとの間に、対物レンズの出射光ビームに複数の収
束点を形成するフレネル帯板を設置したことを特徴とす
る光ヘッド。(1) An optical head characterized in that a Fresnel band plate is installed between a laser beam generator and an objective lens on the optical axis of the laser beam to form a plurality of convergence points on the light beam emitted from the objective lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61035820A JPS62192939A (en) | 1986-02-20 | 1986-02-20 | Optical head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61035820A JPS62192939A (en) | 1986-02-20 | 1986-02-20 | Optical head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62192939A true JPS62192939A (en) | 1987-08-24 |
Family
ID=12452582
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61035820A Pending JPS62192939A (en) | 1986-02-20 | 1986-02-20 | Optical head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62192939A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005078714A1 (en) * | 2004-02-16 | 2005-08-25 | Ricoh Company, Ltd. | Apparatus for reproducing signal from multi-layered optical disk |
| JP2008251134A (en) * | 2007-03-30 | 2008-10-16 | Sony Corp | Optical disk drive, information recording method, and information reproducing method |
-
1986
- 1986-02-20 JP JP61035820A patent/JPS62192939A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005078714A1 (en) * | 2004-02-16 | 2005-08-25 | Ricoh Company, Ltd. | Apparatus for reproducing signal from multi-layered optical disk |
| CN100435225C (en) * | 2004-02-16 | 2008-11-19 | 株式会社理光 | Apparatus for reproducing signal from multi-layered optical disk |
| US7852733B2 (en) | 2004-02-16 | 2010-12-14 | Ricoh Company, Ltd. | Apparatus for reproducing signal from multi-layered optical disk using multiple photo detectors |
| JP2008251134A (en) * | 2007-03-30 | 2008-10-16 | Sony Corp | Optical disk drive, information recording method, and information reproducing method |
| US7944794B2 (en) | 2007-03-30 | 2011-05-17 | Sony Corporation | Optical disc apparatus, information recording method, and information reproduction method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH08241531A (en) | Optical pickup system | |
| JPH1055566A (en) | Optical pickup device | |
| JPH05210868A (en) | Multibeam separation type optical head | |
| JPS62192939A (en) | Optical head | |
| JPH0863780A (en) | Optical pickup device | |
| JPH0391125A (en) | Optical pickup device using wavelength multiplex recording system | |
| JPS601633A (en) | Reproducer of information signal | |
| JPH02192044A (en) | Multi-beam separating device | |
| JPH0612714A (en) | Simultaneous recording and reproducing optical disk and optical head device therefor | |
| JPS60106039A (en) | Optical information processor | |
| JP2806197B2 (en) | Optical pickup | |
| JP2642111B2 (en) | Tracking method in multi-beam optical pickup | |
| JPH08227534A (en) | Optical disk device | |
| JPS61175942A (en) | Multi-optical head | |
| JPH02282937A (en) | Optical head device | |
| JP2730167B2 (en) | Multi-beam optical head device | |
| JPH01276441A (en) | Optical head | |
| JPH073461Y2 (en) | Optical pickup device | |
| JPH08147753A (en) | Optical recording and reproducing device | |
| JPH0391126A (en) | Optical pickup device using wavelength multiplex recording system | |
| JPS5914147A (en) | Optical beam synthesizer | |
| JPS6079534A (en) | Optical information reproducing device | |
| JPS5925626U (en) | Multi-beam optical disk head | |
| JPS63100622A (en) | Optical disk device | |
| JPS6120235A (en) | Optical recording and reproducing device equipped with two light sources |