JPH0731836B2 - Magneto-optical pickup device - Google Patents
Magneto-optical pickup deviceInfo
- Publication number
- JPH0731836B2 JPH0731836B2 JP58173844A JP17384483A JPH0731836B2 JP H0731836 B2 JPH0731836 B2 JP H0731836B2 JP 58173844 A JP58173844 A JP 58173844A JP 17384483 A JP17384483 A JP 17384483A JP H0731836 B2 JPH0731836 B2 JP H0731836B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- reflecting surface
- magneto
- incident
- optical
- 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 - Lifetime
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
Description
【発明の詳細な説明】 本発明は垂直方向に磁化容易軸を有する磁性情報記録媒
体に光学的に情報を記録再生及び消去する光磁気ピック
アップ装置に関するものである。The present invention relates to a magneto-optical pickup device for optically recording / reproducing / erasing information on / from a magnetic information recording medium having an easy axis of magnetization in the vertical direction.
第１図は光磁気ピックアップの動作原理を説明するもの
である。第１図において、 レーザダイオード１から放射される光をコリメートレン
ズ２によって平行光束とし、ビーム整形プリズム３に入
射させる。プリズム３により円形状にされた光束は２個
のハーフミラー４及び５を通過しかつ対物レンズ６によ
って磁性記録媒体７上にスポット状に集光される。磁性
記録媒体７で反射された光は対物レンズ６を通りかつ第
２ハーフミラー５によって２分割され、反射光は検光子
８を通過して光検出器９で受光される。又第２ハーフミ
ラー５の通過光は第１ハーフミラー４で一部反射され、
フォーカス検出用の臨界角プリズム10を通り４分割構成
の光検出器11で受光され、対物レンズ６のフォーカッシ
ング及びトラッキング制御に用いられる。FIG. 1 illustrates the operation principle of the magneto-optical pickup. In FIG. 1, light emitted from a laser diode 1 is collimated by a collimator lens 2 and is made incident on a beam shaping prism 3. The light flux formed into a circular shape by the prism 3 passes through the two half mirrors 4 and 5 and is focused by the objective lens 6 on the magnetic recording medium 7 in a spot shape. The light reflected by the magnetic recording medium 7 passes through the objective lens 6 and is split into two by the second half mirror 5, and the reflected light passes through the analyzer 8 and is received by the photodetector 9. Further, the light passing through the second half mirror 5 is partially reflected by the first half mirror 4,
The light is passed through a focus detection critical angle prism 10 and received by a photodetector 11 having a four-division structure, and is used for focusing and tracking control of the objective lens 6.
前記第１図の構成のものは情報信号が対物レンズ６に最
も近いハーフミラー５で反射される光束により検出する
ようにしたから良好な再生信号が得られる利点がある。The configuration shown in FIG. 1 has an advantage that a good reproduction signal can be obtained because the information signal is detected by the light flux reflected by the half mirror 5 closest to the objective lens 6.
しかしかかる光磁気ピックアップでは整形プリズム３、
２個のハーフミラー４及び５が個別に構成され、２個の
ハーフミラー４及び５間と整形プリズム３とハーフミラ
ー４との間で各光学部材の表面において光量ロスが生じ
る欠点があり良好な再生信号が得られない欠点がある。However, in such a magneto-optical pickup, the shaping prism 3,
The two half mirrors 4 and 5 are individually configured, and there is a disadvantage that a light amount loss occurs on the surface of each optical member between the two half mirrors 4 and 5 and between the shaping prism 3 and the half mirror 4. There is a drawback that a reproduction signal cannot be obtained.
更にビーム整形プリズム３と、ハーフミラー４、５が互
いに分離していることにより装置の組立てが煩雑となる
欠点がある。Further, since the beam shaping prism 3 and the half mirrors 4 and 5 are separated from each other, there is a drawback that assembly of the apparatus becomes complicated.
本発明の光磁気ピックアップ装置はトラック状に記録さ
れた情報を読取るために光源から放射された光束を光分
割光学素子へ入射させその出射光をレンズに入射させ前
記レンズからの収束光を光磁気用の記録媒体へ照射さ
せ、その反射光の少なく共一部を前記レンズに入射させ
た後前記光分割光学素子へ再び入射させ、その後前記光
分割素子の反射面で反射した光束を光検出器で受光して
情報信号と制御信号を検出するようにした光磁気ピック
アップ装置において、 前記光分割素子は直線状の光軸が貫かれると共に該光軸
に対して傾斜した傾きを持つ３つの面を少なくとも有す
るものであり、前記３つの面は前記光源から放出された
楕円形状のビームを円形状のビームに成形するための入
射面と前記記録媒体からの反射光を制御信号検出用の光
検出器へ向けて反射させるため第１の反射面と前記反射
光を情報信号検出用の光検出器へ向けて反射させるため
の第２の反射面とから構成されるものであって、前記入
射面と前記第１の反射面と前記第２の反射面は一体的に
構成された光学面から成るものであり且つ前記レンズよ
り近い順に前記第２の反射面、前記第１の反射面、前記
入射面を直線的に配置したことを特徴のするものであ
る。In the magneto-optical pickup device of the present invention, in order to read information recorded in a track shape, a light beam emitted from a light source is made incident on a light splitting optical element, and its emitted light is made incident on a lens, and the converged light from the lens is made magneto-optical. A recording medium for use in the optical recording medium, and a small part of the reflected light is made incident on the lens and then made incident on the light splitting optical element again, and then the light flux reflected by the reflecting surface of the light splitting element is detected by a photodetector. In a magneto-optical pickup device which is configured to detect an information signal and a control signal by receiving light at, the light splitting element has three surfaces having a linear optical axis penetrating and an inclination inclined with respect to the optical axis. At least one of the three surfaces has an incident surface for shaping the elliptical beam emitted from the light source into a circular beam and a reflected light from the recording medium for detecting a control signal. A first reflecting surface for reflecting the light toward the photodetector and a second reflecting surface for reflecting the reflected light toward the photodetector for detecting an information signal. The incident surface, the first reflecting surface, and the second reflecting surface are optical surfaces integrally formed, and the second reflecting surface, the first reflecting surface, The incident surface is arranged linearly.
以下図面を参照して本発明の一実施例を説明する。An embodiment of the present invention will be described below with reference to the drawings.
第２図は本発明の第１実施例を示す。FIG. 2 shows a first embodiment of the present invention.
光源、例えばレーザダイオード１から放射される光束を
コリメートレンズ２によって平行光束に変形とし、プリ
ズム３の一部であるビーム整形プリズム３′に入射させ
て楕円形状ビームを円形状ビームへ整形させる。プリズ
ム３′により円形状にされた光束はこのプリズム３′と
一体に構成された２個のハーフミラーの基準ブロックを
共用したハーフミラー３′ａ、３′ｂを通過した後対物
レンズ６を通過して磁性記録媒体７上にスポット状に集
束される。磁性記録媒体７で反射された光は再び対物レ
ンズ６を通り、かつハーフミラー３′ａ、３′ｂで２分
割される。即ち第２接合面３′ｂで反射された反射光は
検光子８を通過し光検出器９で受光されここで情報信号
が検出される。一方第２接合面３′ｂを透過し、第１接
合面３′ａで反射された光は臨界角プリズム10を通過し
光検出器11で受光され対物レンズ６のフォーカシング及
びトラッキング制御に用いられる。A light beam emitted from a light source, for example, a laser diode 1 is transformed into a parallel light beam by a collimating lens 2 and is incident on a beam shaping prism 3'which is a part of the prism 3 to shape an elliptical beam into a circular beam. The light beam made circular by the prism 3'passes through the objective lens 6 after passing through the half mirrors 3'a and 3'b sharing the reference block of the two half mirrors integrally formed with the prism 3 '. Then, they are focused on the magnetic recording medium 7 in a spot shape. The light reflected by the magnetic recording medium 7 passes through the objective lens 6 again and is split into two by the half mirrors 3'a and 3'b. That is, the reflected light reflected by the second bonding surface 3'b passes through the analyzer 8 and is received by the photodetector 9 where the information signal is detected. On the other hand, the light transmitted through the second joint surface 3'b and reflected by the first joint surface 3'a passes through the critical angle prism 10, is received by the photodetector 11, and is used for focusing and tracking control of the objective lens 6. .
第３図は本発明光磁気ピックアップ装置の第２実施例を
示す。第２図では、接合面３′ａ、３′ｂが互いに平行
であるのに対し本例は、接合面３′ａ、３′ｂが互いに
直交した関係になっている。その他の構成は第２図に示
すものと同一であるのでその説明は省略する。FIG. 3 shows a second embodiment of the magneto-optical pickup device of the present invention. In FIG. 2, the joint surfaces 3'a and 3'b are parallel to each other, but in this example, the joint surfaces 3'a and 3'b are orthogonal to each other. The other structure is the same as that shown in FIG. 2, and the description thereof is omitted.
第３図の実施例では、情報信号検出用の光検出器９と制
御信号検出用の光検出器11はプリズム３を挾むように配
置される。In the embodiment shown in FIG. 3, the photodetector 9 for detecting the information signal and the photodetector 11 for detecting the control signal are arranged so as to sandwich the prism 3.
以上の様に本発明はひとつの光分割素子（例えば前記実
施例のプリズム３）の入射面（例えば前記実施例の入射
面３′ｃ）でビーム整形を行なわせると共に、光分割素
子内の第１と第２の反射面のうち第２の反射面（例えば
前記実施例の接合面３′ｂ）を対物レンズの近くに配置
し、この第２の反射面からの反射光により磁性記録媒体
の情報を検出するようにし且つ入射面、第１と第２の反
射面が直線状に配されるようにしたから、簡単な光学素
子で良好な情報信号を得ることができる。As described above, according to the present invention, the beam shaping is performed at the incident surface (for example, the incident surface 3'c of the above-described embodiment) of one light-dividing element (for example, the prism 3 of the above-described embodiment), and Of the first and second reflecting surfaces, the second reflecting surface (for example, the cemented surface 3'b in the above embodiment) is arranged near the objective lens, and the reflected light from the second reflecting surface causes the magnetic recording medium to move. Since information is detected and the incident surface and the first and second reflecting surfaces are linearly arranged, a good information signal can be obtained with a simple optical element.
第１図は本発明の動作原理を説明するための光磁気ピッ
クアップの構成を示す説明図、 第２図は本発明光磁気ピックアップの第１実施例を示す
説明図、 第３図は本発明光磁気ピックアップの第２実施例の構成
を示す説明図である。 １……光源 ２……コリメートレンズ ３……プリズム ３′……整形プリズム ３′ａ……ハーフミラー ３′ｂ……ハーフミラー ３′ｃ……入射面 ６……対物レンズ ７……磁性記録媒体 ８……検光子 ９……光検出器 10……臨界角プリズム 11……光検出器。FIG. 1 is an explanatory diagram showing the structure of a magneto-optical pickup for explaining the operation principle of the present invention, FIG. 2 is an explanatory diagram showing a first embodiment of the magneto-optical pickup of the present invention, and FIG. It is explanatory drawing which shows the structure of 2nd Example of a magnetic pickup. 1 ... Light source 2 ... Collimating lens 3 ... Prism 3 '... Shaping prism 3'a ... Half mirror 3'b ... Half mirror 3'c ... Incident surface 6 ... Objective lens 7 ... Magnetic recording Medium 8 ... Analyzer 9 ... Photodetector 10 ... Critical angle prism 11 ... Photodetector
───────────────────────────────────────────────────── フロントページの続き 審判の合議体 審判長 藤田 孝司 審判官 犬飼 宏 審判官 岡田 孝博 (56)参考文献 特開 昭58−128037（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page Judgment panel Chief referee Takashi Fujita Judge Inquiry Hiroshi Inukai Referee Takahiro Okada (56) Reference JP-A-58-128037 (JP, A)
Claims (1)
に光源から放射された光束を光分割光学素子へ入射させ
その出射光をレンズに入射させ前記レンズからの収束光
を光磁気用の記録媒体へ照射させ、その反射光の少なく
共一部を前記レンズに入射させた後前記光分割光学素子
へ再び入射させ、その後前記光分割素子の反射面で反射
した光束を光検出器で受光して情報信号と制御信号を検
出するようにした光磁気ピックアップ装置において、 前記光分割素子は直線状の光軸が貫かれると共に該光軸
に対して傾斜した傾きを持つ３つの面を少なくとも有す
るものであり、前記３つの面は前記光源から放出された
楕円形状のビームを円形状のビームに整形するための入
射面と前記記録媒体からの反射光を制御信号検出用の光
検出器へ向けて反射させるための第１の反射面と前記反
射光を情報信号検出用の光検出器へ向けて反射させるた
めの第２の反射面とから構成されるものであって、前記
入射面と前記第１の反射面と前記第２の反射面は一体的
に構成された光学面から成るものであり且つ前記レンズ
より近い順に前記第２の反射面、前記第１の反射面、前
記入射面が直線的に配置されていることを特徴とする光
磁気ピックアップ装置。1. A light beam emitted from a light source for reading information recorded on a track is incident on a light splitting optical element, and its emitted light is incident on a lens, and the converged light from the lens is recorded for magneto-optical recording. The medium is irradiated, and a small part of the reflected light is made incident on the lens and then made incident again on the light splitting optical element, and then the light beam reflected by the reflecting surface of the light splitting element is received by the photodetector. In a magneto-optical pickup device for detecting an information signal and a control signal, the light splitting element has at least three surfaces having a linear optical axis penetrating and an inclination inclined with respect to the optical axis. And the three surfaces are directed to an incident surface for shaping the elliptical beam emitted from the light source into a circular beam and reflected light from the recording medium toward a photodetector for detecting a control signal. Reflection And a second reflecting surface for reflecting the reflected light toward a photodetector for detecting an information signal, wherein the incident surface and the first reflecting surface are provided. The reflecting surface and the second reflecting surface are optical surfaces integrally formed, and the second reflecting surface, the first reflecting surface, and the incident surface are linear in the order closer to the lens. A magneto-optical pickup device characterized in that the magneto-optical pickup device is arranged in.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58173844A JPH0731836B2 (en) | 1983-09-20 | 1983-09-20 | Magneto-optical pickup device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58173844A JPH0731836B2 (en) | 1983-09-20 | 1983-09-20 | Magneto-optical pickup device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6066348A JPS6066348A (en) | 1985-04-16 |
| JPH0731836B2 true JPH0731836B2 (en) | 1995-04-10 |
Family
ID=15968204
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58173844A Expired - Lifetime JPH0731836B2 (en) | 1983-09-20 | 1983-09-20 | Magneto-optical pickup device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0731836B2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58128037A (en) * | 1982-01-22 | 1983-07-30 | Sharp Corp | Magnetooptical head |
-
1983
- 1983-09-20 JP JP58173844A patent/JPH0731836B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6066348A (en) | 1985-04-16 |
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