JPS59144055A - Optical head - Google Patents

Optical head

Info

Publication number
JPS59144055A
JPS59144055A JP58020327A JP2032783A JPS59144055A JP S59144055 A JPS59144055 A JP S59144055A JP 58020327 A JP58020327 A JP 58020327A JP 2032783 A JP2032783 A JP 2032783A JP S59144055 A JPS59144055 A JP S59144055A
Authority
JP
Japan
Prior art keywords
objective lens
optical
objective
beam splitter
semiconductor laser
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.)
Granted
Application number
JP58020327A
Other languages
Japanese (ja)
Other versions
JPH0827948B2 (en
Inventor
Toyokazu Noda
豊和 野田
Yutaka Oki
裕 大木
Kiyoshi Toyoda
清 豊田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sony Corp
Original Assignee
Sony Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sony Corp filed Critical Sony Corp
Priority to JP58020327A priority Critical patent/JPH0827948B2/en
Publication of JPS59144055A publication Critical patent/JPS59144055A/en
Publication of JPH0827948B2 publication Critical patent/JPH0827948B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording 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
    • G11B7/12Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/123Integrated head arrangements, e.g. with source and detectors mounted on the same substrate

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE:To reduce the length of an optical head in the optical axis direction of an objective by shifting together the objective, the semiconductor laser of a light source and an optical system including a photodetector. CONSTITUTION:An optical head contains a semiconductor laser 21 which forms a light source, a polarized beam splitter 22, a 1/4 wavelength plate 24, a rectangular prism 25, an objective 26, a photodetector 28 which detects the laser light reflected by the splitter 22, etc. in one body. Such an optical system is shifted toward the optical axis of the lens 26 as well as in the direction rectangular to said optical axis for purposes of focusing and tracking respectively. Therefore it is possible to reduce the size of the objective 26 as well as the distance between the objective 26 and the prism 25 in comparison with the case where only the objective 26 is shifted. As a result, the length of the optical head can be reduced in the optical axis direction of the objective 26.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、光学式ディスク再生装置などに用いられる光
学ヘッドに関する。
DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical head used in an optical disk reproducing device or the like.

背景技術とその問題点 光学式ディスク再生装置に用いられる光学ヘッドとして
は、大別して、半導体レーザーよりのレーザー光が途中
で経路を曲げられることなく対物レンズに入射するタイ
プのものと、半導体レーザーよりのレーザー光が途中で
直角プリズムやミラーにより経路を直角に曲げられて対
物レンズに入射するタイプのものとがある。前者のタイ
プのものは、ディスクの回転軸方向に沿う方向の長さが
大きくなり、ディスク再生装置の偏平化が妨げられるが
、後者のタイプのものは、ディスクの回転軸方向に沿う
方向の長さを小さくでき、ディスク再生装置の偏平化を
はかることができる。
Background Art and Problems Optical heads used in optical disc playback devices can be roughly divided into two types: those from a semiconductor laser, in which the laser beam enters the objective lens without bending its path midway; There is a type in which the laser beam is bent at a right angle by a right-angle prism or mirror midway through, and then enters the objective lens. The former type has a large length along the rotational axis of the disc, which prevents flattening of the disc playback device, but the latter type has a large length along the rotational axis of the disc. The disc playback device can be made flat.

第1図及び第Ω図は後者のタイプの従来の光学ヘッドの
一例で、半導体レーザー//よりのレーザー光が、偏光
ビームスプリツターハI透過し、コリメーターレンズ/
3により発散光から平行光に変換され、−波長板/クラ
介して直角プリズム/Sに入射して経路が直角に曲げら
れ、対物レンズ/乙によシ集束されてディスク/に照射
される。
Figures 1 and Ω are examples of the latter type of conventional optical head, in which laser light from a semiconductor laser is transmitted through a polarized beam splitter I and collimated through a collimator lens.
3, the diverging light is converted into parallel light, enters the right angle prism/S via the wavelength plate/cluster, its path is bent at right angles, is focused by the objective lens/B, and is irradiated onto the disk/.

ディスク/で反射されたレーザー元は、対物レンズ/乙
を介して直角プリズム/Sに入射して経路が直角に曲げ
られ、−波長板/グ及びコリメーター 一し7ズ/3を介し、偏光ビームスプリッタ−/、2で
反射されて更に経路が直角に曲げられ、シリンドリカル
レンズ77を介して光検出器/gに到達して電気信号に
変換される。そして、対物レンス/乙がフォーカス制御
とトラッキング制御の光軸方向であるディスク/の回転
軸方向(第1図の上下方向)とこれに対して直交するデ
ィスク/の半径方向(第1図の左右方向)に動かされる
The laser beam reflected by the disk / passes through the objective lens / B and enters the right-angle prism / S, and its path is bent at right angles. The beam is reflected by the beam splitter 2, the path of which is bent at a right angle, and reaches the photodetector 77 via the cylindrical lens 77, where it is converted into an electrical signal. The objective lens/A is the optical axis direction for focus control and tracking control in the rotational axis direction of the disk (vertical direction in Figure 1) and the radial direction of the disk (left and right in Figure 1) perpendicular to this direction. direction).

しかし、この従来の光学ヘッドは、コリメーターレンズ
/3を用いて半導体レーザー//よシの発散光を平行光
に変換するとともに、対物レンズ/乙のみをディスク/
の回転軸方向と半径方向に動かしてフォーカス制御とト
ラッキング制御を行なうので、ディスク/の回転軸方向
の長さをなお充分に小さくできない不都合がある。
However, this conventional optical head converts the diverging light of the semiconductor laser into parallel light using the collimator lens /3, and converts only the objective lens /3 into the disk /
Since focus control and tracking control are performed by moving the disk in the direction of the rotation axis and in the radial direction, there is a problem that the length of the disk in the direction of the rotation axis cannot be made sufficiently small.

即ち、この従来の光学ヘッドのディスク/の回転軸方向
の長さは、第1図から明らかなように、対物レンズ/乙
の厚さと、直角プリズム/Sの高さと、対物レンズ/A
、!=[角プリズム/Sの距離の和になるが、フォーカ
ス制御のために対物レンズ/乙が直角プリズム/Sなど
他の光学部品に対してディスク/の回転軸方向(第1図
の上下方向)に動かされる際に対物レンズ/乙が直角プ
リズム/Sにぶつからないように、対物レンズ/乙と直
角プリズム/Sの距離は2■以上確保する必要がある。
That is, as is clear from FIG. 1, the length of the conventional optical head in the direction of the rotational axis of the disk is determined by the thickness of the objective lens A, the height of the right angle prism S, and the objective lens A.
,! = [This is the sum of the distances of the square prisms/S, but for focus control, the objective lens/B is the right angle prism/S and other optical components in the direction of the disk/'s rotation axis (vertical direction in Figure 1) To prevent the objective lens/B from colliding with the right-angle prism/S when it is moved, the distance between the objective lens/B and the right-angle prism/S must be at least 2cm.

マタ、このように対物レンズ/乙の作動距離が、2Wr
m以上にされる場合に、トラッキング制御のために対物
レンズ/乙が直角プリズム/Sなど他の光学部品に対し
てディスク/の半径方向(第1図の左右方向)K動かさ
れても直角プリズム/左ヲ介した平行ビームが対物レン
ズ/乙の視野からはずれないように、直角プリズム/3
VC入射するビームの径を左、S鏑ぐらいKする必要が
あり、(3) そのために、直角プリズム/Sの高さは乙、grmn以
上にする必要がある。さらに、対物レンズ/乙の厚さは
通常3trrm以上になる。従って、ヘッド全体のディ
スク/の回転軸方向の長さは/3.!;關以上になる。
Mata, like this, the working distance of the objective lens/O is 2Wr.
m or more, even if the objective lens is moved in the radial direction (horizontal direction in Figure 1) of the disk relative to other optical components such as the right-angle prism for tracking control, the right-angle prism remains / Right angle prism / 3 to prevent the parallel beam passing through the left side from deviating from the field of view of the objective lens /
It is necessary to set the diameter of the beam incident on the VC to about S, (3) Therefore, the height of the rectangular prism/S needs to be greater than or equal to grmn. Furthermore, the thickness of the objective lens/B is usually 3 trrm or more. Therefore, the length of the entire head in the direction of the rotational axis of the disk is /3. ! ;Become more than concerned.

発明の目的 本発明は、半導体レーザーよりのレーザー元が途中で直
角プリズムやミラーにより経路を直角に曲げられて対物
レンズに入射するタイプの光学ヘッドにおいて、光学ヘ
ッドの対物レンズの光軸方向の長さ、即ちディスク再生
用の場合にはディスクの回転軸方向の長さをより小でく
することができるようにしたものである。
Purpose of the Invention The present invention provides an optical head of a type in which a laser source from a semiconductor laser is bent at a right angle by a right-angle prism or mirror midway and enters an objective lens. In other words, in the case of disc playback, the length of the disc in the rotational axis direction can be made smaller.

発明の概要 本発明では、コリメーターレンズを用いて半導体レーザ
ーよりの発散光全平行光に変換した上で対物レンズによ
シ集束させるのではなく、半導体レーザーよりの球面波
を直接、ディスクなどの被照射体上に集光させるもので
、そのために対物レンズとして有限倍率のものを用いる
。同時に、本(+り 発明では、半導体レーザー、偏光ビームスプリッタ−2
直角プリズムまたはミラー、対物レンズ。
Summary of the Invention In the present invention, instead of using a collimator lens to convert the diverging light from a semiconductor laser into fully parallel light and then focusing it on an objective lens, the spherical wave from the semiconductor laser is directly transmitted to a disk, etc. It focuses light onto the object to be irradiated, and for this purpose an objective lens with a finite magnification is used. At the same time, in the book (plus invention), semiconductor laser, polarizing beam splitter-2
Right angle prism or mirror, objective lens.

光検出器などのすべての光学部品を7つの鏡筒内に収納
し、ヘッド全体を二軸の駆動装置にょシフオーカス制御
とトラッキング制御のために対物レンズの光軸方向とこ
れに直交する方向に動かすようにする。
All optical components such as photodetectors are housed in seven lens barrels, and the entire head is moved by a two-axis drive device in the direction of the optical axis of the objective lens and in a direction perpendicular to this for focus control and tracking control. Do it like this.

実  施  例 第3図〜第S図は本発明の光学ヘッドの一例を二軸の駆
動装置の一例とともに示すもので、有限倍率の対物レン
ズとして一点から発散する球面波を別の点に収束する球
面波に変換するレンズ作用を有するホログラムを用いた
場合である。
Embodiment Figures 3 to S show an example of the optical head of the present invention together with an example of a two-axis drive device, which serves as an objective lens with a finite magnification to converge a spherical wave diverging from one point to another point. This is a case where a hologram having a lens action that converts into a spherical wave is used.

即ち、光学ヘッド、20は半導体レーザー2/。That is, the optical head 20 is a semiconductor laser 2/.

偏光ビームスプリッタ−2,2,、波長板、211.i
[角プ+)ダム2.!;+有限倍率の対物レンズλ乙、
シリンドリカルレンズ27及び光検出器2gからなるが
、対物レンズa乙として一点から発散する球面波を別の
点に収束する球面波に変換するレンズ作用を有するホロ
グラムが用いられ、半導体装置ザー27から発散するレ
ーザー光が、偏光ビームスプリッタ−22を透過し、−
波長板2’l’fr介しダ て直角プリズム2左に入射して経路が直角に曲げられ、
対物レンズ2Aにより集束されてディスク/に照射され
、ディスク/で反射されたレーザー光が、対物レンズΩ
乙を介して直角プリズム2左に入射して経路が直角に曲
げられ、7波長板21Iを介し、偏光ビームスプリッタ
−,22で反射されて更に経路が直角に曲げられ、シリ
ンドリカルレンズ27を介して光検出器2gに到達して
電気信号に変換される。
Polarizing beam splitter 2, 2, wave plate, 211. i
[Kakupu +) Dam 2. ! ; + objective lens λ with finite magnification;
It consists of a cylindrical lens 27 and a photodetector 2g, and a hologram having a lens action that converts a spherical wave that diverges from one point into a spherical wave that converges at another point is used as the objective lens a. The laser beam transmitted through the polarizing beam splitter 22,
It enters the right angle prism 2 left through the wave plate 2'l'fr, and its path is bent at right angles.
The laser beam that is focused by the objective lens 2A and irradiated onto the disk/, and reflected by the disk/, is reflected by the objective lens Ω
The beam enters the right-angle prism 2 to the left through the cylindrical lens 27, is bent at a right angle, passes through the 7-wave plate 21I, is reflected by the polarizing beam splitter 22, and is further bent at a right angle, and passes through the cylindrical lens 27. The light reaches the photodetector 2g and is converted into an electrical signal.

かような対物レンズ2乙として用いられるホログラムは
、第6図に示すように、対物レンズ3/の光路上に補助
のホログラム32と対物レンズλ乙として用いられるホ
ログラムとなるべきダイクロメートゼラチンなどの薄膜
2乙a’に配し、補助のホログラム3λによる開口数が
sinθlの収束球面波と対物レンズ3/による開口数
がsinθコの発散球面波を薄膜λ乙a上で干渉させて
作ることができる。即ち、これによれば、薄膜2乙aは
、点F/から発散する開口数がsinθlの球面波を点
F2に収束する開口数がsinθコの球面波に変換する
レンズ作用を有する対物レンズコ乙として用いられるホ
ログラムになる。なお、補助のホログラム32は、第7
図に示すように、対物レンズ33の光路上に補助のホロ
グラム32となるべき薄膜32a’x配し、平面波と対
物レンズ33による開口数がsinθ/の発散球面波全
薄膜32a上で干渉させて作ることができる。
As shown in FIG. 6, the hologram used as such an objective lens 2B includes an auxiliary hologram 32 on the optical path of the objective lens 3/ and a hologram made of dichromate gelatin or the like to be used as the objective lens λB. It is possible to create a convergent spherical wave with a numerical aperture of sinθl by an auxiliary hologram 3λ placed on the thin film 2a′ and a diverging spherical wave with a numerical aperture of sinθl by the objective lens 3/ on the thin film λa′. can. That is, according to this, the thin film 2a is an objective lens having a lens action that converts a spherical wave with a numerical aperture of sinθl that diverges from the point F/ into a spherical wave with a numerical aperture of sinθl that converges on the point F2. It becomes a hologram used as a hologram. Note that the auxiliary hologram 32 is the seventh
As shown in the figure, a thin film 32a'x, which is to become an auxiliary hologram 32, is arranged on the optical path of the objective lens 33, and a plane wave and a diverging spherical wave with a numerical aperture of sin θ/ by the objective lens 33 are caused to interfere on the entire thin film 32a. can be made.

この光学ヘッド20は矩形の短かい筒部グOとそのT端
側を覆う板部4/により形成される部屋内に収納され、
各光学部品が筒部tIOあるいは板部ll/に取り付け
られる。ただし、対物レンズ2乙は板部グ/に形成され
た窓穴にはめこまれ、部屋の外部に臨まされる。板部l
l/の半導体レーザー2/、偏+ビームスプリッター2
2,7波長板2’l及び直角プリズム2左の配列方向の
両端には脚部lI2及びグ3が一体に形成され、この脚
部グλ及び4t3にフォーカス制御用のコイルlI乙及
びlI7がそれぞれ取シ付けられる。また、筒部lIO
の偏光ビームスプリッタ−2λ、シリンドリカルレンズ
λ7及び光検出器、2gの配列方向の一側面の中央部に
トラッキング制御用のコイルグ9が取り付けられる。一
方、はぼU字形の基板S/の脚部32及びS3に8字形
のヨーク54及び&5がそれぞれ取り付けられ、ヨーク
SII及び55の両側の脚部にマグネットS乙及びS7
がそれぞれ取り付けられて、基板S/の脚部S2及びS
3にフォーカス制御用の磁気回路が形成される。
This optical head 20 is housed in a chamber formed by a short rectangular cylinder part O and a plate part 4/ that covers the T end side thereof.
Each optical component is attached to the cylinder part tIO or the plate part ll/. However, the objective lens 2B is fitted into a window hole formed in the plate part G/, and is exposed to the outside of the room. Plate l
l/ semiconductor laser 2/, polarized + beam splitter 2
Legs lI2 and g3 are integrally formed at both ends of the 2 and 7 wavelength plate 2'l and the left side of the right angle prism 2 in the arrangement direction, and coils lIb and lI7 for focus control are attached to the leg parts gλ and 4t3. Can be installed respectively. In addition, the cylindrical portion lIO
A coil ring 9 for tracking control is attached to the center of one side in the arrangement direction of the polarizing beam splitter 2λ, cylindrical lens λ7, photodetector 2g. On the other hand, 8-shaped yokes 54 and &5 are attached to the legs 32 and S3 of the U-shaped board S/, respectively, and magnets S and S7 are attached to the legs on both sides of the yokes SII and 55.
are attached respectively to the legs S2 and S of the substrate S/
3, a magnetic circuit for focus control is formed.

また、基板S/の中央部に8字形のヨークSgが取り付
けられ、ヨークSgの両側の脚部にマグネツ13−9が
取シ付けられて、基板S/の中央部にトラッキング制御
用の磁気回路が形成される。そして、筒部グOが基板3
/の脚部S2及び左3のフォーカス制御用のλつの磁気
回路の間に挿入され、フォーカス制御用のコイルt/を
乙及びグアがそれぞれの磁気回路の空隙内に挿入され、
トラッキング制御用のコイル4t9が基板S/の中央部
のトラッキング制御用の磁気回路の空隙内に挿入され、
筒部グ0がダンパー乙コ及び乙3によりヨーク54及び
5.tに、従って基板左/に支持される。
In addition, an 8-shaped yoke Sg is attached to the center of the board S/, magnets 13-9 are attached to the legs on both sides of the yoke Sg, and a magnetic circuit for tracking control is attached to the center of the board S/. is formed. Then, the cylindrical part O is connected to the substrate 3.
The coil t/ for focus control is inserted between the legs S2 and the left 3 magnetic circuits for focus control, and the coil t/ for focus control is inserted into the gap between the respective magnetic circuits.
A coil 4t9 for tracking control is inserted into the gap of the magnetic circuit for tracking control in the center of the substrate S/,
The cylindrical part G0 is connected to the yokes 54 and 5 by the dampers Otsuko and Otsu3. t and thus supported on the left/left of the substrate.

従って、光学ヘッド20全体が、筒部lIOやコイルグ
乙、l17及びlI9などとともに、基板S/やヨーク
、tlI、55及び左gなどに対して、フォーカス制御
のために対物レンズ2乙の光軸方向であるディスク/の
回転軸方向(第3図の紙面に垂直な方向、即ち、第9図
及び第S図の上下方向)に動かされるとともに、トラッ
キング制御のためにこれと直交するディスクlの半径方
向(第3図の上下方向、即ち、第9図及び第S図の紙面
に垂直な方向)に動かされる。
Therefore, the entire optical head 20, together with the cylindrical portion lIO, coil ring O, l17 and lI9, etc., is connected to the optical axis of the objective lens 2O for focus control with respect to the substrate S/, yoke, tlI, 55, left g, etc. The direction of the rotational axis of the disk / (in the direction perpendicular to the plane of the paper in Fig. 3, that is, the vertical direction in Figs. 9 and S), and the direction of the rotation axis of the disk / perpendicular to this direction for tracking control. It is moved in the radial direction (in the vertical direction in FIG. 3, ie, in the direction perpendicular to the plane of the paper in FIGS. 9 and S).

有限倍率の対物レンズ2Aとしては、上述のホログラム
の代わシに通常のガラスレンズを用いてもよい。この場
合も、光学ヘッド及び二軸の駆動装置は、第3図〜第S
図の例と同様に構成すればよい。
As the finite magnification objective lens 2A, a normal glass lens may be used instead of the above-mentioned hologram. In this case as well, the optical head and the two-axis drive device are shown in FIGS.
The configuration may be similar to the example shown in the figure.

なお、第3図〜第S図の例は、半導体レーザー2/より
のレーザー光が偏光ビームスプリッタ−22を透過し、
ディスク/で反射されたレーザー光が偏光ビームスプリ
ッタ−22で反射される場合であるが、逆に、半導体レ
ーザーよりのレーザー光が偏光ビームスプリッタ−で反
射され、ディスクで反射されたレーザー光が偏光ビーム
スプリッタ−を透過するようにしてもよい。
In the examples shown in FIGS. 3 to S, the laser beam from the semiconductor laser 2/ is transmitted through the polarizing beam splitter 22,
In this case, the laser beam reflected by the disk is reflected by the polarizing beam splitter 22, but conversely, the laser beam from the semiconductor laser is reflected by the polarizing beam splitter, and the laser beam reflected by the disk becomes polarized. The light may be transmitted through a beam splitter.

また、直角プリズム2左の代わりにミラーを用いてもよ
い。
Further, a mirror may be used instead of the left side of the right angle prism 2.

発明の効果 本発明によれば、対物レンズとして有限倍率のものを用
いて半導体レーザーよりの球面波全直接、ディスクなど
の被照射体上に集光させるとともに、半導体レーザー、
偏光ビームスプリッタ−1直角プリズムまたはミラー、
対物レンズ、光検出器などのすべての光学部品をフォー
カス制御とトラッキング制御のために対物レンズの光軸
方向とこれに直交する方向に一体に動かすようにしたの
で、光学ヘッドの対物レンズの光軸方向の長さ、即ちデ
ィスク再生用の場合にはディスクの回転軸方向の長さを
より小さくすることができる。即ち、本発明によれば、
直角プリズムト]たはミラーに入射するビームが球面波
であるとともに、対物レンズΩ乙が他の光学部品に対し
て独立にその光軸方向と直交する方向に動かされず、対
物レンズ、2乙に入射するビームの径を大きくする必要
がないので、直角プリズム2左またはミラーの高さをダ
〜グ、3tanぐらいにすることができ、また、対物レ
ンズコ乙が他の光学部品に対して独立にその光軸方向に
動かされないので、対物レンズλ乙ト直角プリズム2!
;’!fCはミラーの距離をほとんど零にすることがで
き、対物レンズλ乙として通常のガラスレンズを用いる
場合でも、ヘッド全体の対物レンズΩ乙の光軸方向の長
さ全従来に比べてグ〜グ、り咽ぐらい短かくすることが
できる。特に、対物レンズλ乙としてホログラムを用い
る場合には、レンズの主面がホログラムの膜面と一致す
るので、口径のわりに作動距離が長くとれ、対物レンズ
λ乙に入射するビームの径を小さくできるので、直角プ
リズム2Sまたはミラーの高さを3〜3、!Wmぐらい
にすることができ、対物レンズ2乙の厚みもΩ■ぐらい
になるので、ヘッド全体の対物レンズλ乙の光軸方向の
長さ全従来に比べてざ(//) 〜ざ、3叫も短かくすることができる。
Effects of the Invention According to the present invention, an objective lens with a finite magnification is used to focus the entire spherical wave from a semiconductor laser directly onto an irradiated object such as a disk, and the semiconductor laser,
Polarizing beam splitter - 1 right angle prism or mirror,
All optical components such as the objective lens and photodetector are moved together in the direction of the optical axis of the objective lens and in the direction orthogonal to this for focus control and tracking control, so the optical axis of the objective lens of the optical head is The length in the direction, that is, in the case of disc reproduction, the length in the direction of the rotation axis of the disc can be made smaller. That is, according to the present invention,
The beam incident on the right-angle prism or mirror is a spherical wave, and the objective lens Ω is not moved in a direction perpendicular to its optical axis independently with respect to other optical components, and the beam is incident on the objective lens Ω. Since there is no need to increase the diameter of the beam to be used, the height of the right-angle prism 2 or mirror can be set to approximately 3 tan, and the objective lens 2 can be adjusted independently from other optical components. Since it is not moved in the optical axis direction, the objective lens λ and the right-angle prism 2!
;'! With fC, the distance between the mirrors can be reduced to almost zero, and even when a normal glass lens is used as the objective lens λ, the length of the entire head in the optical axis direction of the objective lens Ω is significantly smaller than that of the conventional one. It can be made as short as the length of the throat. In particular, when a hologram is used as the objective lens λB, the main surface of the lens coincides with the film surface of the hologram, so the working distance can be long compared to the aperture, and the diameter of the beam incident on the objective lens λB can be reduced. Therefore, the height of the right angle prism 2S or mirror should be 3~3! Since the thickness of the objective lens 2 can be approximately Wm, and the thickness of the objective lens 2 is also approximately Ω■, the length of the objective lens λ of the entire head in the optical axis direction is smaller than that of the conventional one. Screams can also be made shorter.

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

第1図及び第Ω図は従来の光学ヘッドの一例を示すもの
で、第1図は側面図、第Ω図は平面図、第3図〜第S図
は本発明の光学ヘッドの一例を二軸の駆動装置の一例と
ともに示すもので、第3図は一部を切り欠いた平面図、
第9図はそのIV−IV線上の断面図、第S図は側面図
、第4図及び第7図はホログラムの作9方の説明のため
の図である。 図中1,2/は半導体レーザー、λΩは偏光ビームスプ
リッタ−1,2Sは直角プリズム、2乙は対物レンズ1
,2gは光検出器である。 (/2) 第1図 第2図 手続補正書 1.事件の表示 昭和Sg年特許願第20327号 2、発明の名称 光学ヘッド 3、補正をする者 事件との関係    特許出願人 住  所   東京部品用区北品用乙丁目7番33号名
 称  (,27ざ)ソニー株式会社代表者大賀典雄 6、補正によシ増加する発明の数 な し7、補正の対
象 明細書の特許請求の範囲の欄及び発明の詳細な説明
の欄 8、補正の内容 (1)  特許請求の範囲を別紙の通り補正する。 (2)  明細書中、第3頁15行「左右方向」とある
を[紙面に対して垂直方向]に訂正する。 以上 特許請求の範囲 半導体レーザーと、この半導体レーザーよりのレーザー
光を透過あるいは反射させるビームスプリッタ−と、こ
のビームスプリッタ−を介したレーザー光の経路を直角
に曲げる光学部品と、この光学部品を介したレーザー光
を集束する有限倍率の対物レンズと、この対物レンズに
反対方向より入射し、上記光学部品で経路が直角に曲げ
られ、上記ビームスプリッタ−で反射され、あるいは上
記ビームスプリンターを透過したレーザー光を検出する
光検出器とを有し、上記半導体レーザー。 ビームスプリンター、光学部品、対物レンズ及び光検出
器が、上記対物レンズの光軸方向及びこれと直交する方
向に一体に動かされるようにされた光学ヘッド。
Figures 1 and Ω show an example of a conventional optical head. Figure 1 is a side view, Figure Ω is a plan view, and Figures 3 to S are two examples of the optical head of the present invention. It is shown together with an example of a shaft drive device, and Fig. 3 is a partially cutaway plan view;
FIG. 9 is a sectional view taken along the line IV--IV, FIG. S is a side view, and FIGS. 4 and 7 are views for explaining how to make a hologram. In the figure, 1 and 2/ are semiconductor lasers, λΩ is a polarizing beam splitter, 1 and 2S are right-angle prisms, and 2 is an objective lens 1.
, 2g is a photodetector. (/2) Figure 1 Figure 2 Procedural amendment 1. Display of the case Showa Sg Year Patent Application No. 20327 2, Title of the invention Optical head 3, Person making the amendment Relationship to the case Patent applicant address 7-33 Otsu-chome, Kitashinyo-ku, Tokyo Parts Name (, 27) Sony Corporation Representative Norio Ohga6, Number of inventions to be increased due to amendment None7, Subject of amendment Column of Claims of Specification and Detailed Description of Invention Column8, Contents of Amendment (1) Amend the claims as shown in the attached sheet. (2) In the specification, the phrase "horizontal direction" on page 3, line 15, is corrected to "perpendicular to the page." The above claims include a semiconductor laser, a beam splitter that transmits or reflects laser light from the semiconductor laser, an optical component that bends the path of the laser light via the beam splitter at right angles, and a An objective lens with a finite magnification that focuses the laser beam, and a laser beam that enters the objective lens from the opposite direction, whose path is bent at a right angle by the optical component, is reflected by the beam splitter, or is transmitted through the beam splitter. and a photodetector for detecting light, the semiconductor laser as described above. An optical head in which a beam splinter, an optical component, an objective lens, and a photodetector are moved together in the optical axis direction of the objective lens and in a direction perpendicular thereto.

Claims (1)

【特許請求の範囲】[Claims] 半導体レーザーと、この半導体レーザーよりのレーザー
光を透過あるいは反射させる偏光ビームスプリッタ−と
、この偏光ビームスプリッタ−を介したレーザー光の経
路を直角に曲げる光学部品と、この光学部品を介したレ
ーザー光を集束する有限倍率の対物レンズと、この対物
レンズに反対方向より入射し、上記光学部品で経路が直
角に曲げられ、上記偏光ビームスプリッタ−で反射され
、あるいは上記偏光ビームスプリッタ−を透過したレー
ザー光を検出する光検出器とを有し、上記半導体レーザ
ー、偏光ビームスプリッタ−2光学部品、対物レンズ及
び光検出器が、上記対物レンズの光軸方向及びこれと直
交する方向に一体に動かされるようにされた光学ヘッド
A semiconductor laser, a polarizing beam splitter that transmits or reflects the laser beam from the semiconductor laser, an optical component that bends the path of the laser beam through the polarizing beam splitter at right angles, and a laser beam that passes through the optical component. an objective lens with a finite magnification that focuses the laser beam, and a laser beam that enters the objective lens from the opposite direction, whose path is bent at right angles by the optical component, and is reflected by the polarizing beam splitter or transmitted through the polarizing beam splitter. a photodetector that detects light, and the semiconductor laser, the polarizing beam splitter 2 optical component, the objective lens, and the photodetector are moved together in the optical axis direction of the objective lens and in a direction perpendicular thereto. Optical head made like this.
JP58020327A 1983-02-08 1983-02-08 Optical head Expired - Lifetime JPH0827948B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP58020327A JPH0827948B2 (en) 1983-02-08 1983-02-08 Optical head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP58020327A JPH0827948B2 (en) 1983-02-08 1983-02-08 Optical head

Publications (2)

Publication Number Publication Date
JPS59144055A true JPS59144055A (en) 1984-08-17
JPH0827948B2 JPH0827948B2 (en) 1996-03-21

Family

ID=12024033

Family Applications (1)

Application Number Title Priority Date Filing Date
JP58020327A Expired - Lifetime JPH0827948B2 (en) 1983-02-08 1983-02-08 Optical head

Country Status (1)

Country Link
JP (1) JPH0827948B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62234243A (en) * 1986-03-26 1987-10-14 Nec Home Electronics Ltd Optical pickup device
JP2007535719A (en) * 2003-07-07 2007-12-06 シンボル テクノロジーズ インコーポレイテッド Imaging apparatus and barcode imager for imaging optical code or target at multiple focal planes

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55163566A (en) * 1979-06-05 1980-12-19 Sony Corp Hologram lens and its production and optical system signal using this hologram lens
JPS5630439U (en) * 1979-08-06 1981-03-24
JPS56144136A (en) * 1980-04-14 1981-11-10 Mitsubishi Rayon Co Ltd Injection molding device for polyester resin

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55163566A (en) * 1979-06-05 1980-12-19 Sony Corp Hologram lens and its production and optical system signal using this hologram lens
JPS5630439U (en) * 1979-08-06 1981-03-24
JPS56144136A (en) * 1980-04-14 1981-11-10 Mitsubishi Rayon Co Ltd Injection molding device for polyester resin

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62234243A (en) * 1986-03-26 1987-10-14 Nec Home Electronics Ltd Optical pickup device
JP2007535719A (en) * 2003-07-07 2007-12-06 シンボル テクノロジーズ インコーポレイテッド Imaging apparatus and barcode imager for imaging optical code or target at multiple focal planes

Also Published As

Publication number Publication date
JPH0827948B2 (en) 1996-03-21

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