JPS6130328B2 - - Google Patents
Info
- Publication number
- JPS6130328B2 JPS6130328B2 JP55064572A JP6457280A JPS6130328B2 JP S6130328 B2 JPS6130328 B2 JP S6130328B2 JP 55064572 A JP55064572 A JP 55064572A JP 6457280 A JP6457280 A JP 6457280A JP S6130328 B2 JPS6130328 B2 JP S6130328B2
- Authority
- JP
- Japan
- Prior art keywords
- mirror
- light
- light source
- optical
- recording medium
- 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.)
- Expired
Links
Classifications
-
- 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
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
-
- 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
- G11B7/002—Recording, reproducing or erasing systems characterised by the shape or form of the carrier
- G11B7/0033—Recording, reproducing or erasing systems characterised by the shape or form of the carrier with cards or other card-like flat carriers, e.g. flat sheets of optical film
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Optical Recording Or Reproduction (AREA)
- Optical Head (AREA)
Description
【発明の詳細な説明】
本発明は光記録媒体に情報を光学的に記録、再
生する光学式記録再生装置に関するものであり、
光源レーザーの小型化、及び再生信号量の増大化
をはかることを目的とするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical recording and reproducing device that optically records and reproduces information on an optical recording medium.
The purpose of this is to reduce the size of the light source laser and increase the amount of reproduced signals.
従来の光学式記録再生装置の光学系において
は、光源から媒体に到達するまでの光路上で受光
することが出来ないため、その光路上にハーフミ
ラーを置き、ビームを分割して受光するものであ
つた。しかしながらこの方式は、光源から出射し
た光が受光器に到達するまでにハーフミラーを２
回通過するために、光伝送効率が激減し、レーザ
ー光源の大型化あるいは再生信号量不足という問
題が生じる欠点があつた。これらの問題を解決す
るために、一部では偏光を利用したビームスプリ
ツターが用いられている。この方式は、光源に直
線偏光を使用し、ビームスプリンターとしてＰ偏
光とＳ偏光のどちらか一方が反射し他方が透過す
る偏光プリズムを用い、さらにそのビームスプリ
ツターと記録媒体の間に1/4波長板を設けるもの
であり、このような構成にすることにより、光源
からの出射した偏向はビームスプリツターにより
ほとんどすべて反射され、1/4波長板を往復する
ことにより偏光面を90度回転させ、記録媒体から
の反射光はビームスプリツターを透過させること
ができる。この結果、総合伝送効率は極めて良く
なり、一部は実用に供している。 In the optical system of conventional optical recording and reproducing devices, it is not possible to receive light on the optical path from the light source to the medium, so a half mirror is placed on the optical path to split the beam and receive the light. It was hot. However, this method requires two half mirrors before the light emitted from the light source reaches the receiver.
Due to the multiple passes, the optical transmission efficiency is drastically reduced, resulting in problems such as an increase in the size of the laser light source and an insufficient amount of reproduced signals. To solve these problems, beam splitters that utilize polarization are used in some cases. This method uses linearly polarized light as a light source, a polarizing prism as a beam splitter that reflects either P-polarized light or S-polarized light, and transmits the other, and a 1/4-inch space between the beam splitter and the recording medium. With this configuration, almost all of the polarized light emitted from the light source is reflected by the beam splitter, and the plane of polarization is rotated by 90 degrees by going back and forth through the quarter-wave plate. , the reflected light from the recording medium can be transmitted through the beam splitter. As a result, the overall transmission efficiency has become extremely high, and some of them are now in practical use.
しかしながら、磁気光学記録媒体の再生原理
は、媒体からの反射光のＰ成分とＳ成分を検出す
ることにより、偏光面の回転方向を検知するた
め、上記の従来法は適用することができない。 However, the principle of reproduction of magneto-optical recording media is that the direction of rotation of the plane of polarization is detected by detecting the P component and S component of the reflected light from the medium, so the above conventional method cannot be applied.
本発明は、偏光を利用する磁気光学記録媒体の
再生に適用しても総合伝送効率を著しく向上させ
ることができ、その結果、レーザー光源の小型化
再生信号の増大化が期待できる光学式記録再生装
置を提供するものである。 The present invention is an optical recording and reproducing method that can significantly improve the overall transmission efficiency even when applied to reproducing magneto-optical recording media that utilize polarized light, and as a result, it is possible to miniaturize the laser light source and increase the reproduction signal. It provides equipment.
以下本発明の一実施例を図面を用いて詳述する
第１図に本発明による実施例の光学系を示す。直
線偏光レーザー光源１を出射した光はミラー２に
入射角50゜で入射される。このミラー２は、第２
図に示す通り、三角柱の一つの側面６と他の側面
７の二面が全反射面になつているものであり、そ
の全反射面で構される夾角を100゜に設定したも
のである。ミラー２の全反射面６で反射された光
は、集光レンズ３を介して記録媒体４の面上で焦
点を結ぶ。このとき、記録媒体４面上での入射角
は10゜であるが、磁気光学記録媒体のKerr回転
角は、例えばMnBi薄膜を例にとると入射角20゜
以下ではほとんど変化せず、入射角による信号特
性の劣化はない。一方記録媒体４上で反射した光
は、入射光軸とは分離し、ミラー２の全反射面の
うち、レーザー光源から来た光を反射する面とは
別の全反射面７で反射させ、そのあと受光部５で
光検出を行う。これらの光学系の構成によると、
半透鏡使用の場合に比べ、総合伝送効率は約４倍
になり、その結果再生用レーザー光源パワーを1/
４にすることができ、装置を小型化することがで
きる。また、レーザー光源パワーを一定として考
えると、受光部に到達する光量が増し、その結果
約２倍のSN比が得られるものである。 An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an optical system of an embodiment according to the present invention. Light emitted from a linearly polarized laser light source 1 is incident on a mirror 2 at an incident angle of 50°. This mirror 2 is
As shown in the figure, one side 6 and the other side 7 of the triangular prism are total reflection surfaces, and the included angle formed by the total reflection surfaces is set to 100°. The light reflected by the total reflection surface 6 of the mirror 2 is focused on the surface of the recording medium 4 via the condenser lens 3. At this time, the angle of incidence on the four surfaces of the recording medium is 10°, but the Kerr rotation angle of the magneto-optical recording medium, for example, in the case of a MnBi thin film, hardly changes when the angle of incidence is less than 20°; There is no deterioration of signal characteristics due to On the other hand, the light reflected on the recording medium 4 is separated from the incident optical axis, and is reflected on a total reflection surface 7 of the mirror 2 that is different from the surface that reflects the light coming from the laser light source. Thereafter, light detection is performed by the light receiving section 5. According to the configuration of these optical systems,
Compared to the case of using a semi-transparent mirror, the overall transmission efficiency is approximately 4 times higher, and as a result, the power of the laser light source for reproduction can be reduced by 1/2.
4, and the device can be made smaller. Furthermore, assuming that the power of the laser light source is constant, the amount of light reaching the light receiving section increases, and as a result, the S/N ratio is approximately doubled.
さらに第１図に示すように、光源１からミラー
２に達するまでの光路と、ミラー２から受光系に
達するまでの光路を同一直線上に位置させ、その
同一直線上に沿つてミラー２を図中の矢印方向Ｌ
に駆動できるようにし、ミラー２の駆動系を用い
て記録媒体上のトラツクを追随させると、トラツ
キングサーボ駆動による受光位置のズレは全く考
慮する必要がなく、光検出を容易に行うことでき
る。 Furthermore, as shown in FIG. 1, the optical path from the light source 1 to the mirror 2 and the optical path from the mirror 2 to the light receiving system are positioned on the same straight line, and the mirror 2 is plotted along the same straight line. Inside arrow direction L
If the drive system of the mirror 2 is used to follow the track on the recording medium, there is no need to take into account any deviation in the light receiving position due to the tracking servo drive, and light detection can be easily performed.
なお、本発明は偏光ビームスプリツタを用いる
ことのできない磁気光学記録媒体の再生について
特に顕著な効果が期待できる。しかしながら本発
明を、ヒートモード方式による光干渉を利用した
再生に利用すると、偏光ビームスプリツタを用い
る場合と同程度の光源レーザーの小型化、SN比
の増大が期待できるだけでなく、光源として直線
偏光レーザーを用いる必要がなくなり、トラツキ
ングサーボによる受光位置のずれも全く考慮する
必要がなく光学設計も容易に行なうことができ
る。 Note that the present invention can be expected to have a particularly remarkable effect on reproduction of magneto-optical recording media in which a polarizing beam splitter cannot be used. However, if the present invention is used for reproduction using optical interference using a heat mode method, not only can the light source laser be made smaller and the signal-to-noise ratio can be increased to the same degree as when using a polarized beam splitter, but also linearly polarized light can be used as a light source. There is no need to use a laser, and there is no need to consider any deviation in the light receiving position due to the tracking servo, making optical design easier.
また本発明の装置は、記録時のフオーカスサー
ボ系に利用することができ、再生系と同様に伝送
効率の増大が期待でき、レーザ光源の小型化が可
能となるものである。 Furthermore, the device of the present invention can be used in a focus servo system during recording, and can be expected to increase transmission efficiency similarly to a reproducing system, making it possible to downsize the laser light source.
第１図は本発明の一実施例における光学式記録
再生装置の再生光学系の概略図、第２図は同装置
のミラーの斜視図である。
１……光源、２……ミラー、３……集光レン
ズ、４……記録媒体、５……受光部、６，７……
全反射面。
FIG. 1 is a schematic view of a reproducing optical system of an optical recording/reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a mirror of the apparatus. 1... Light source, 2... Mirror, 3... Condensing lens, 4... Recording medium, 5... Light receiving section, 6, 7...
Totally reflective surface.
Claims (1)
具備し、光源からの光を上記ミラーの一方の全反
射面で反射させて記録媒体に入射させ、上記記録
媒体で反射された光を上記ミラーの他の全反射面
で反射させて受光するよう構成するとともに、上
記光源から上記ミラーへの入射光軸と、上記ミラ
ーからの出射光軸とを平行に設定し、上記ミラー
への入射光軸に沿つて上記ミラーを駆動し、上記
記録媒体上のトラツクを追随させることを特徴と
する光学式記録再生装置。1 A mirror having at least two total reflection surfaces is provided, the light from the light source is reflected by one total reflection surface of the mirror and incident on the recording medium, and the light reflected by the recording medium is reflected by the other mirror. The optical axis of incidence from the light source to the mirror is set parallel to the optical axis of output from the mirror, and the optical axis of incidence to the mirror is set parallel to the optical axis of incidence to the mirror. An optical recording/reproducing apparatus characterized in that the mirror is driven to follow a track on the recording medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6457280A JPS56159848A (en) | 1980-05-14 | 1980-05-14 | Optical recording and reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6457280A JPS56159848A (en) | 1980-05-14 | 1980-05-14 | Optical recording and reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56159848A JPS56159848A (en) | 1981-12-09 |
| JPS6130328B2 true JPS6130328B2 (en) | 1986-07-12 |
Family
ID=13262066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6457280A Granted JPS56159848A (en) | 1980-05-14 | 1980-05-14 | Optical recording and reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56159848A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61111036U (en) * | 1984-12-24 | 1986-07-14 |
-
1980
- 1980-05-14 JP JP6457280A patent/JPS56159848A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56159848A (en) | 1981-12-09 |
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