JPS6266452A - Photomagnetic head - Google Patents

Abstract

PURPOSE:To attain the miniaturization by providing a split polarized element having a different polarized face while being placed on an optical axis and a multi-split light sensor split into >=2 detecting light transmitting through the polarized element. CONSTITUTION:A laser light irradiated from a semiconductor laser 16 is collimated nearly by a converting lens 17, reflected in a half mirror 18 and irradiated into an optomagnetic disc 15 through a condenser lens 14. A read light beam 1a reflected from the disc 15 is made incident in the split polarized elements 11 having different polarized faces and the transmitted light is divided into two light beams 1b, 1c whose phase of intensity change is deviated depending on the change in the recorded information on the photomagnetic disc 15 and made incident in the multi-split sensor 12. As the read information, the output of the multi-split sensors 12b, 12c corresponding respectively to light beams 1b, 1c divided into two by the split polarized element 11 is inputted to a differential amplifier 13. Then number of components of the optomagnetic head is less and miniaturization is attained.

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、特に光磁気情報読み出しの光
磁気ヘッドに関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disk device, and particularly to a magneto-optical head for reading magneto-optical information.

〔従来の技術〕[Conventional technology]

従来、この種の光磁気ヘッドは磁気光学効果によって光
磁気ディスク上の情報を読み出すため、第２図に示すよ
うに、半導体レーザ２９を出射したレーザ光は収束レン
ズ３０によりほぼ平行光にされ、ハーフミラ−３１によ
り反射され、集光レンズ２７を通り、光磁気ディスク２
８上に照射される。光磁気ディスク２８から反射し、集
光レンズ２７によりほぼ平行光にされた読み出し光ビー
ム２ａはハーフミラ−３１を通り、ビームスプリッタ２
１により分けられ、分けられた光ビーム２ｂ　＋　２　
ｃはそれぞれ個別の偏光素子２２．２３を通り、別々の
光センサ２４，２５に入射し、２つの光センサ２４，２
５の出力を差動増幅器２６に入力し、光磁気ディスク２
８から記録された情報を読み出していた。Conventionally, this type of magneto-optical head reads information on a magneto-optical disk using the magneto-optic effect, so as shown in FIG. It is reflected by the half mirror 31, passes through the condensing lens 27, and enters the magneto-optical disk 2.
8. The readout light beam 2a reflected from the magneto-optical disk 28 and made into almost parallel light by the condensing lens 27 passes through the half mirror 31 and is sent to the beam splitter 2.
1 and divided light beam 2b + 2
c passes through individual polarizing elements 22 and 23 and enters separate optical sensors 24 and 25, and the two optical sensors 24 and 2
5 is input to the differential amplifier 26, and the output of the magneto-optical disk 2
The information recorded from 8 was being read out.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

上述した従来の光磁気ヘッドは読み出し光を２つに分け
るためのビームスプリッタが必要であり、また２組の偏
光素子と２組の光センサが必要であり、部品数が多くな
り、小型化が困難であるという欠点がある。The conventional magneto-optical head described above requires a beam splitter to split the read light into two, and also requires two sets of polarizing elements and two sets of optical sensors, which increases the number of parts and makes it difficult to miniaturize. The disadvantage is that it is difficult.

本発明は前記問題点を解消し、小型化を実現できる光磁
気ヘッドを提供するものである。The present invention solves the above problems and provides a magneto-optical head that can be miniaturized.

〔問題点を解決するための手段〕[Means for solving problems]

本発明は磁気光学効果により光磁気ディスク等に記録さ
れた情報を読み出す光磁気ヘッドにおいて、光磁気ディ
スク等から反射又は透過した読み出し光を平行光にする
集光レンズと、平行光にされた読み出し光の光軸上に置
いた互いに異なる偏光面をもつ分割偏光素子と、偏光素
子を通過した光を検出する少なくとも２つ以上に分割さ
れた多分割光センサとを有することを特徴とする磁気ヘ
ッドである。The present invention provides a magneto-optical head that reads information recorded on a magneto-optical disk or the like using the magneto-optic effect. A magnetic head characterized by having a divided polarizing element placed on the optical axis of light and having mutually different polarization planes, and a multi-segmented optical sensor divided into at least two parts for detecting the light that has passed through the polarizing element. It is.

〔実施例〕〔Example〕

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図は本発明の光磁気ヘッドの一実施例を示す構成図
である。第１図において、本発明は集光レンズ１４と、
読み出し光の光軸上に置いた互いに異なる偏光面をもつ
２分割偏光素子１１と、少なくとも２分割された多分割
光センサ１２とを有する。FIG. 1 is a block diagram showing an embodiment of the magneto-optical head of the present invention. In FIG. 1, the present invention includes a condenser lens 14;
It has a two-split polarizing element 11 placed on the optical axis of readout light and having mutually different polarization planes, and a multi-split optical sensor 12 divided into at least two parts.

光磁気ディスク等からの読み出し情報は磁気光学効果に
より光磁気ディスク等からの読み出し光ビームの直線偏
光向のずれとなって含まれる。Information read from a magneto-optical disk or the like is contained as a shift in the linear polarization direction of a read light beam from the magneto-optical disk or the like due to the magneto-optic effect.

半導体レーザ１６を出射したレーザ光は収束レンズ】７
によりほぼ平行光にされ、ハーフミラ−１８により反射
され、集光レンズ１４を通り光磁気ディスク１５上に照
射される。The laser light emitted from the semiconductor laser 16 is passed through a converging lens]7
The light is made into almost parallel light, reflected by the half mirror 18, passes through the condenser lens 14, and is irradiated onto the magneto-optical disk 15.

光磁気ディスク１５から反射した読み出し光ビーム１ａ
は互いに偏光面の異なった分割偏光素子１１に入射し、
通過した光は分割偏光素子１１によって光磁気ディスク
１５上に記録された情報の変化に応じて強度変化の位相
のずれた２つの光ビーム１ｂ、１ｃに分けられ、少なく
とも２つ以上に分割された多分割センサ１２に入射され
る。Readout light beam 1a reflected from magneto-optical disk 15
are incident on the divided polarizing elements 11 with mutually different polarization planes,
The transmitted light is divided into two light beams 1b and 1c whose intensity changes are out of phase according to the change in the information recorded on the magneto-optical disk 15 by the splitting polarizing element 11, and is divided into at least two or more light beams. The light is incident on the multi-divided sensor 12.

読み出し情報は分割偏光素子１１により２つに分けられ
た光ビームｌｂ、ｌｃにそれぞれ対応した多分割センサ
１２ｂ、１２ｃの出力を差動増幅器１３に入力し、その
出力に現れる。The readout information is obtained by inputting the outputs of the multi-divided sensors 12b and 12c corresponding to the light beams lb and lc, respectively, which are divided into two by the split polarizing element 11, into the differential amplifier 13, and appearing at the output thereof.

〔発明の効果〕〔Effect of the invention〕

以上説明したように本発明は光磁気ディスク等からの読
み出し光の光軸上に分割偏光素子と多分割センサとを置
くことにより、光磁気ヘッドの部品数を少なくし、小型
化できる効果がある。As explained above, the present invention has the effect of reducing the number of components of the magneto-optical head and making it more compact by placing the split polarizing element and the multi-segment sensor on the optical axis of the read light from the magneto-optical disk, etc. .

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の光磁気ヘッドを示す構成図、第２図は
従来の光磁気ヘッドを示す構成図である。 １１・・・２分割偏光素子　　１２・・・多分割光セン
サ１３・・・差動増幅器　　　　ｌａ・・・読み出し光
ビーム１４・・・集光レンズ　　　　１５・・・光磁気
ディスク１６・・・半導体レーザ　　　１７・・・収束
レンズ１８・・・ハーフミラ−FIG. 1 is a block diagram showing a magneto-optical head of the present invention, and FIG. 2 is a block diagram showing a conventional magneto-optical head. DESCRIPTION OF SYMBOLS 11... Two-split polarizing element 12... Multi-segment optical sensor 13... Differential amplifier la... Readout light beam 14... Condensing lens 15... Magneto-optical disk 16... Semiconductor laser 17... Converging lens 18... Half mirror

Claims (1)

【特許請求の範囲】[Claims] （１）磁気光学効果により光磁気ディスク等に記録され
た情報を読み出す光磁気ヘッドにおいて、光磁気ディス
ク等から反射又は透過した読み出し光を平行光にする集
光レンズと、平行光にされた読み出し光の光軸上に置い
た互いに異なる偏光面をもつ分割偏光素子と、その偏光
素子を通過した光を検出する少なくとも２つ以上に分割
された多分割光センサとを有することを特徴とする光磁
気ヘッド。(1) In a magneto-optical head that reads information recorded on a magneto-optical disk, etc. using the magneto-optic effect, a condenser lens converts the readout light reflected or transmitted from the magneto-optical disk, etc. into parallel light, and a readout light that is converted into parallel light. Light characterized by having a split polarizing element placed on the optical axis of the light and having mutually different polarization planes, and a multi-segmented optical sensor split into at least two parts for detecting the light that has passed through the polarizing element. magnetic head.