JP2672618B2 - Optical information recording / reproducing device - Google Patents
Optical information recording / reproducing deviceInfo
- Publication number
- JP2672618B2 JP2672618B2 JP1002321A JP232189A JP2672618B2 JP 2672618 B2 JP2672618 B2 JP 2672618B2 JP 1002321 A JP1002321 A JP 1002321A JP 232189 A JP232189 A JP 232189A JP 2672618 B2 JP2672618 B2 JP 2672618B2
- Authority
- JP
- Japan
- Prior art keywords
- optical
- light
- optical information
- information recording
- beam splitter
- 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
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、光情報記録媒体にレーザ光を照射し、情報
の記録、再生を行う光情報記録再生装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for irradiating an optical information recording medium with a laser beam to record / reproduce information.
従来の技術 従来の光情報記録再生装置を第６図に基づいて説明す
る。半導体レーザ１から出射されたレーザ光はコリメー
トレンズ２により平行化されビームスプリツタ３により
偏光された後、ミラー４を介して、対物レンズ５により
集光され光情報記録媒体としての光磁気デイスク６に照
射され、これにより情報の記録が行われる。また、その
光磁気デイスク６からの反射光は前記ビームスプリツタ
３、λ/2板７を順次透過した後、光情報検出光学系８内
に導かれる。この光情報検出光学系８内では、光磁気デ
イスク６により反射された光が偏光ビームスプリツタ９
により２つの互いに直交する直線偏光液に分離され、一
方では直進して集光レンズ10により集光されたトラツク
受光素子11に導かれることによりトラツクエラー信号が
検出され、また、他方では前記偏光ビームスプリツタ９
により反射され集光レンズ12、ウエツジプリズム13、凹
レンズ14を順次透過してフオーカス受光素子15に導かれ
ることによりフオーカスエラー信号が検出される。さら
に、これら２つの受光素子11,15に検出される総受光量
を求めることにより光磁気信号を検出して情報の再生を
行つている。2. Description of the Related Art A conventional optical information recording / reproducing apparatus will be described with reference to FIG. The laser light emitted from the semiconductor laser 1 is collimated by the collimator lens 2 and polarized by the beam splitter 3, and then focused by the objective lens 5 via the mirror 4 and the magneto-optical disk 6 as an optical information recording medium. The information is recorded. Further, the reflected light from the magneto-optical disk 6 is sequentially transmitted through the beam splitter 3 and the λ / 2 plate 7 and then guided into the optical information detecting optical system 8. In the optical information detection optical system 8, the light reflected by the magneto-optical disc 6 is polarized beam splitter 9
Is separated into two linearly polarized liquids orthogonal to each other, and on the one hand, a track error signal is detected by going straight and being guided to the track light receiving element 11 condensed by the condenser lens 10. Pritta 9
The focus error signal is detected by being sequentially reflected by the condenser lens 12, the wedge prism 13, and the concave lens 14 and guided to the focus light receiving element 15. Further, the magneto-optical signal is detected and the information is reproduced by obtaining the total amount of received light detected by these two light receiving elements 11 and 15.
発明が解決しようとする課題 上述したような従来の装置の場合、光情報検出光学系
８内において偏光ビームスプリツタ９により光路が２分
割され、特にフオーカス検出光路系におけるレンズ焦点
距離が長いため小型化できずスペース効率が悪くなり、
その結果、装置全体が大型化してしまうということや、
また、これにより部品点数が多く組み付け調整が難しい
ため生産効率が悪くコスト高になるという問題がある。
このように光ピツクアツプ光学系全体が大型化してしま
うと重量が重くなり高速アクセスに対応することができ
ないという問題がある。Problems to be Solved by the Invention In the case of the conventional device as described above, the optical path is divided into two by the polarization beam splitter 9 in the optical information detection optical system 8, and particularly, the lens focal length in the focus detection optical path system is long, so that the size is small. Cannot be realized, and space efficiency becomes poor,
As a result, the overall size of the device will increase,
Further, this causes a problem that production efficiency is poor and cost is high because the number of parts is large and assembly and adjustment are difficult.
If the entire optical pickup optical system becomes large in this way, there is a problem that the weight becomes heavy and high-speed access cannot be supported.
課題を解決するための手段 そこで、このような問題点を解決するために、本発明
は、半導体レーザから出射された光をビームスプリツタ
を介して光情報記録媒体に照射し情報の記録を行うと共
に、その光情報記録媒体からの反射光を前記ビームスプ
リツタを介して光情報検出光学系に導き情報の再生や、
トラツクエラー信号、フオーカスエラー信号を検出する
光情報記録再生装置において、前記光情報記録媒体から
の光反射光が前記ビームスプリツタを通過して前記光情
報検出光学系に導かれた光路上に、光学レンズを介し
て、ピツチの異なる同心円状をした回折格子の形成され
たグレーテイング素子を配設し、このグレーテイング素
子を透過した光を検出する互いに直交する直線状の分割
線とその交点を中心とする円状の分割線とにより少なく
とも８分割された受光面をもつ光検知器を設けた。In order to solve such a problem, the present invention irradiates light emitted from a semiconductor laser onto an optical information recording medium via a beam splitter to record information. Together with the reproduction of information by guiding the reflected light from the optical information recording medium to the optical information detection optical system via the beam splitter,
In the optical information recording / reproducing apparatus for detecting the track error signal and the focus error signal, the light reflected light from the optical information recording medium is passed through the beam splitter to the optical path guided to the optical information detecting optical system. , Grating elements formed with concentric diffraction gratings with different pitches are arranged through an optical lens, and straight dividing lines that intersect each other for detecting the light transmitted through this grating element and their intersections. A photodetector having a light-receiving surface divided into at least eight parts by a circular dividing line centered at is provided.
作用 光情報記録媒体からの反射光は直線偏光波の状態で、
光情報検出光学系内の光学レンズを介してグレーテイン
グ素子の回折格子に導かれ回折光となり、この回折光は
光検知器の受光面に検知され、これによりフオーカスエ
ラー信号、トラツクエラー信号、光磁気信号等を検出す
ることができる。The reflected light from the optical information recording medium is in the state of a linearly polarized wave,
It is guided to the diffraction grating of the grating through the optical lens in the optical information detection optical system to become diffracted light, and this diffracted light is detected by the light-receiving surface of the photodetector, whereby the focus error signal, the track error signal, It is possible to detect a magneto-optical signal or the like.
実施例 本発明の一実施例を第１図ないし第４図に基づいて説
明する。なお、光情報記録再生装置の全体構成について
の説明は省略し、ここでは本発明に係る光情報検出光学
系についてのみ述べる。また、従来技術と同一部分につ
いては同一符号を用いる。Embodiment An embodiment of the present invention will be described with reference to FIGS. The description of the entire configuration of the optical information recording / reproducing apparatus is omitted, and only the optical information detecting optical system according to the present invention will be described here. Further, the same reference numerals are used for the same parts as those in the conventional technique.
グテーテイング素子16は、その表面にピツチＴの異な
る同心円状をした回折格子17が形成されている。このグ
レーテイング素子16は光情報記録体としての光磁気デイ
スク６により反射され光が光情報検出光学系８に導かれ
た光路上に位置して、光学レンズとしての凸レンズ18を
介して配設されている。また、前記グレーテイング素子
16を透過した光の光路上は光検知器19が配設されてお
り、この光検知器19には互いに直交する直線状の分割線
A,Bとその交点を中心とする円状の分割線Ｃとにより８
分割された受光面（a0,a1,b0,b1,c0,c1,d0,d1）が形成
されている。A grating 17 having concentric circles with different pitches T is formed on the surface of the grating element 16. This grating element 16 is located on the optical path where the light reflected by the magneto-optical disc 6 as an optical information recording body is guided to the optical information detecting optical system 8 and is arranged via a convex lens 18 as an optical lens. ing. Also, the above-mentioned rating element
A photodetector 19 is arranged on the optical path of the light transmitted through 16, and the photodetector 19 has linear dividing lines orthogonal to each other.
8 by A and B and a circular dividing line C centered on the intersection
Divided light receiving surfaces (a 0 , a 1 , b 0 , b 1 , c 0 , c 1 , d 0 , d 1 ) are formed.
このような構成において、光磁気デイスク６からの反
射光は、ビームスプリツタ３、λ/2板７を順次透過して
直線偏光波（Ｓ偏光波とＰ偏光波とを含む）となり、光
情報検出光学系８内の凸レンズ17を介して、グレーテイ
ング素子16に導かれる。この場合、直線偏光波は、第４
図に示すように、Ｓ偏光波の方がＰ偏光波よりも回折効
率が大きいため、このような回折効率の異なる直線偏光
波をグレーテイング素子16の回折格子17に入力させる
と、その入力場所によつて回折効率が異なつた回折光が
得られることになり、この状態で光検知器19の８分割さ
れた受光面20に検出されることになる。In such a configuration, the reflected light from the magneto-optical disc 6 sequentially passes through the beam splitter 3 and the λ / 2 plate 7 to become a linearly polarized wave (including an S polarized wave and a P polarized wave), and the optical information It is guided to the grating element 16 via the convex lens 17 in the detection optical system 8. In this case, the linearly polarized wave is
As shown in the figure, since the S-polarized wave has a higher diffraction efficiency than the P-polarized wave, if such a linearly polarized wave having a different diffraction efficiency is input to the diffraction grating 17 of the grating element 16, the input position As a result, diffracted light having different diffraction efficiencies can be obtained, and in this state, the light is detected by the eight-divided light-receiving surface 20 of the photodetector 19.
この場合、フオーカスエラー信号は、スポツトサイズ
法により（a0＋b0＋c0＋d0）−（a1＋b1＋c1＋d1）を求
めることにより検出することができる。また、トラツク
エラー信号は、サンプルサーボ方式をとることによつて
８分割された受光面20の総受光量を求めることにより検
出することができ、コンテイニユアス方式をとるならば
受光面20を分割する分割線A,Bのうちのいずれか一方の
分割線を光磁気デイスク６のトラツク方向に合わせ、そ
の左右の光量差から検出することができる。さらに、光
検知器19において、通常、a0＋a1とc0＋c1とに検出され
る受光量は等しく、また、b0＋b1とd0＋d1とに検出され
る受光量も等しい関係にある。そして、この状態でグレ
ーテイング素子16に入射する直線偏光波が回転すると、
b0＋b1とd0＋d1とに検出される回折光の受光量は減少
し、a0＋a1とc0＋c1とに検出される回折光の受光量は増
える傾向にあるため、これにより、光磁気信号は（a0＋
a1）＋（c0＋c1）−（b0＋b1）−（d0＋d1）の値を求め
ることにより検出することができる。In this case, Fuo dregs error signal by Supotsutosaizu method (a 0 + b 0 + c 0 + d 0) - can be detected by obtaining the (a 1 + b 1 + c 1 + d 1). The track error signal can be detected by obtaining the total amount of light received by the light-receiving surface 20 divided into eight by using the sample servo method. If the continuous method is adopted, the light-receiving surface 20 can be divided. Any one of the dividing lines A and B to be aligned can be aligned with the track direction of the magneto-optical disc 6 and can be detected from the difference in light amount between the left and right sides thereof. Further, in the photodetector 19, the received light amounts detected by a 0 + a 1 and c 0 + c 1 are usually equal, and the received light amounts detected by b 0 + b 1 and d 0 + d 1 are also equal. It is in. Then, when the linearly polarized wave incident on the grating 16 in this state rotates,
The received light amount of diffracted light detected by b 0 + b 1 and d 0 + d 1 tends to decrease, and the received light amount of diffracted light detected by a 0 + a 1 and c 0 + c 1 tends to increase. Therefore, the magneto-optical signal becomes (a 0 +
a 1) + (c 0 + c 1) - (b 0 + b 1) - can be detected by determining the value of (d 0 + d 1).
上述したように、光情報検出光学系８内に、ピツチの
異なる同心円状をした回折格子17をもつグレーテイング
素子16と、直線状の分割線A,B及び同心円状の分割線Ｃ
により８分割された受光面20をもつ光検知器19とを設け
ることによつて、フオーカスエラー信号やトラツクエラ
ー信号、さらには、光磁気信号を同時に検出することが
でき、これにより、部品点数を大幅に削減することがで
きるため装置全体の構成を一段と小型、軽量にすること
ができる。As described above, in the optical information detecting optical system 8, the grating element 16 having the concentric diffraction gratings 17 with different pitches, the linear dividing lines A and B, and the concentric dividing line C are provided.
By providing the photodetector 19 having the light-receiving surface 20 divided into eight by the method, the focus error signal, the track error signal, and further the magneto-optical signal can be detected at the same time. Since it is possible to significantly reduce the size, it is possible to further reduce the size and weight of the entire device.
次に、本発明の変形例を第５図に基づいて説明する。
これは、光情報検出光学系８内における光学レンズを変
えた場合の例である。すなわち、光学レンズに凹レンズ
21を用いたことによつて、光路長を一段と短くすること
ができ、しかも、凹レンズ21とグレーテイング素子16と
を一体化することができるため、前述した実施例に比べ
一段とスペースを省略化することができ、これにより装
置の小型、軽量化を一層図ることができる。Next, a modified example of the present invention will be described with reference to FIG.
This is an example when the optical lens in the optical information detection optical system 8 is changed. That is, a concave lens as an optical lens
By using 21, the optical path length can be further shortened, and since the concave lens 21 and the grating element 16 can be integrated, the space can be further reduced as compared with the above-described embodiment. This makes it possible to further reduce the size and weight of the device.
発明の効果 本発明は、光情報記録媒体からの反射光を光情報検出
光学系内のピツチの異なる同心円状をした回折格子の形
成されたグレーテイング素子に入射させ、その回折を少
なくとも８分割された受光面をもつ光検知器に検出させ
ることにより、フオーカスエラー信号やトラツクエラー
信号、さらには、光磁気信号等を検出することができ、
これにより、光情報検出光学系内における部品点数を削
減でき、しかも、光路長を短くしてスペースの省略化を
図ることができるため、装置全体の構成を一段と小型、
軽量化することが可能となり、しかも、組み付け調整が
簡単となるため生産性を上げコストを一層低減させるこ
とができるものである。According to the present invention, the reflected light from the optical information recording medium is incident on the grating element in which the concentric diffraction gratings with different pitches are formed in the optical information detection optical system, and the diffraction is divided into at least eight. By detecting with a photodetector having a light receiving surface, it is possible to detect focus error signals and track error signals, as well as magneto-optical signals,
As a result, the number of components in the optical information detection optical system can be reduced, and the optical path length can be shortened to reduce the space.
Since the weight can be reduced and the assembling adjustment is easy, the productivity can be increased and the cost can be further reduced.
第１図は本発明の一実施例を示す説明図、第２図はその
グレーテイング素子の正面図、第３図は光検知器の正面
図、第４図は入射光の偏光波と回折効率との関係を示す
グラフ、第５図は本発明の変形例を示す説明図、第６図
は従来例を示す説明図である。 １……半導体レーザ、３……ビームスプリツタ、６……
光情報記録媒体、８……光情報検出光学系、16……グレ
ーテイング素子、17……回折格子、18……光学レンズ、
19……光検知器、20……受光面、21……光学レンズ、Ｔ
……ピツチ、A,B,C……分割線FIG. 1 is an explanatory view showing an embodiment of the present invention, FIG. 2 is a front view of the grating element, FIG. 3 is a front view of a photodetector, and FIG. 4 is a polarized wave of incident light and diffraction efficiency. FIG. 5 is an explanatory diagram showing a modified example of the present invention, and FIG. 6 is an explanatory diagram showing a conventional example. 1 ... Semiconductor laser, 3 ... Beam splitter, 6 ...
Optical information recording medium, 8 ... Optical information detection optical system, 16 ... Grating element, 17 ... Diffraction grating, 18 ... Optical lens,
19 ... Photodetector, 20 ... Light receiving surface, 21 ... Optical lens, T
...... Pitch, A, B, C …… Dividing line
Claims (1)
プリツタを介して光情報記録媒体に照射し情報の記録を
行うと共に、その光情報記録媒体からの反射光を前記ビ
ームスプリツタを介して光情報検出光学系に導き情報の
再生や、トラツクエラー信号、フオーカスエラー信号を
検出する光情報記録再生装置において、前記光情報記録
媒体からの反射光が前記ビームスプリツタを通過して前
記光情報検出光学系に導かれた光路上に、光学レンズを
介して、ピツチの異なる同心円状をした回折格子の形成
されたグレーテイング素子を配設し、このグレーテイン
グ素子を透過した光を検出する互いに直交する直線状の
分割線とその交点を中心とする円状の分割線とにより少
なくとも８分割された受光面をもつ光検知器を設けたこ
とを特徴とする光情報記録再生装置。1. An optical information recording medium is irradiated with light emitted from a semiconductor laser through a beam splitter to record information, and reflected light from the optical information recording medium is transmitted through the beam splitter. In the optical information recording / reproducing apparatus for detecting the information reproduced by the optical information detection optical system, the track error signal, and the focus error signal, the reflected light from the optical information recording medium passes through the beam splitter and A grating element having a concentric diffraction grating with different pitches is arranged on the optical path guided to the information detection optical system through an optical lens, and the light transmitted through this grating element is detected. A light comprising a photodetector having a light-receiving surface divided into at least 8 parts by a straight dividing line which is orthogonal to each other and a circular dividing line whose center is an intersection thereof. Broadcast recording and reproducing apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1002321A JP2672618B2 (en) | 1989-01-09 | 1989-01-09 | Optical information recording / reproducing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1002321A JP2672618B2 (en) | 1989-01-09 | 1989-01-09 | Optical information recording / reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02183453A JPH02183453A (en) | 1990-07-18 |
| JP2672618B2 true JP2672618B2 (en) | 1997-11-05 |
Family
ID=11526058
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1002321A Expired - Lifetime JP2672618B2 (en) | 1989-01-09 | 1989-01-09 | Optical information recording / reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2672618B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2823871B2 (en) * | 1988-06-13 | 1998-11-11 | 本田技研工業株式会社 | Method of manufacturing movable side plate in viscous fluid coupling device, and movable side plate obtained by the manufacturing method |
| JPH05120726A (en) * | 1991-10-25 | 1993-05-18 | Nec Corp | Optical information recording and reproducing device |
| JP2542858Y2 (en) * | 1992-11-30 | 1997-07-30 | 財団法人工業技術研究院 | Magneto-optical head |
| US6088322A (en) | 1998-05-07 | 2000-07-11 | Broome; Barry G. | Single objective lens for use with CD or DVD optical disks |
| ATE441183T1 (en) | 1999-01-22 | 2009-09-15 | Konica Minolta Opto Inc | OPTICAL SCANNING DEVICE, RECORDING/RECORDING DEVICE EQUIPPED WITH THE OPTICAL SCANNING DEVICE, OPTICAL ELEMENT AND METHOD FOR DATA RECORDING/REPRODUCTION |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6285111A (en) * | 1985-10-09 | 1987-04-18 | Mazda Motor Corp | Exhaust system structure for engine |
-
1989
- 1989-01-09 JP JP1002321A patent/JP2672618B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02183453A (en) | 1990-07-18 |
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