JPS61289544A - Optical head device - Google Patents
Optical head deviceInfo
- Publication number
- JPS61289544A JPS61289544A JP60129482A JP12948285A JPS61289544A JP S61289544 A JPS61289544 A JP S61289544A JP 60129482 A JP60129482 A JP 60129482A JP 12948285 A JP12948285 A JP 12948285A JP S61289544 A JPS61289544 A JP S61289544A
- Authority
- JP
- Japan
- Prior art keywords
- light
- light beam
- information
- prism
- optical head
- 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.)
- Pending
Links
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- Optical Head (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、情報相体の情報記録面に光を照射し、情報の
書き込み又は読出しを行う光ヘッド装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical head device that writes or reads information by irradiating an information recording surface of an information medium with light.
ディスク状の情報相体に情報を記録し、又は記録した情
報を再生する光ヘッド装置において、光ヘッドを小型軽
量化することは、高速アクセスを達成する上で多くの利
点をもたらす。In an optical head device that records information on a disk-shaped information medium or reproduces recorded information, making the optical head smaller and lighter brings many advantages in achieving high-speed access.
本出願人は、特願昭59−132293号及び特願昭5
9−132294号において、小型軽量な光ヘッドを提
案した。The applicant has filed Japanese Patent Application No. 59-132293 and Patent Application No. 5
In No. 9-132294, a small and lightweight optical head was proposed.
第6図は、上記特許出願に記載されている光ヘッド装置
の構成図である。FIG. 6 is a configuration diagram of the optical head device described in the above patent application.
同図において、半導体レーザ11から出射したP偏光は
コリメータレンズ12により平行光束となり、光分割器
13に入射する。光分割器13は、平行平板14及び1
6と、回折格子15とから構成されている。In the figure, P-polarized light emitted from a semiconductor laser 11 is turned into a parallel beam by a collimator lens 12 and enters a light splitter 13. The light splitter 13 includes parallel plates 14 and 1
6 and a diffraction grating 15.
光分割器13を透過したP偏光は、対物レンズ18によ
って集光し、基板19に形成された記録面20に径1p
m前後のスポットを形成する。記録面20には情報が磁
気的に記録されているために、入射光の偏光面に対する
反射光17の偏光面は、記録された情報に応じて回転し
ている(磁気的カー効果によるカー回転)。The P-polarized light transmitted through the light splitter 13 is condensed by an objective lens 18, and is focused onto a recording surface 20 formed on a substrate 19 with a diameter of 1 p.
A spot of around m is formed. Since information is magnetically recorded on the recording surface 20, the polarization plane of the reflected light 17 with respect to the polarization plane of the incident light rotates according to the recorded information (Kerr rotation due to the magnetic Kerr effect). ).
偏光面の回転した反射光17は、光分割器13に再び入
射し、回折格子15によって回折される。この回折光2
2は、平行平板14の上面又は平行平板16の下面で全
反射を繰り返して導かれ、検光子21を介して光検出器
23に入射する0回折光22は、記録面20に記録され
た情報に対応して偏光面が回転しているために、検光子
21によって記録面20に記録された情報に対応した光
量変化に変換され、その光量変化が光検出器23によっ
て電気信号に変換される。The reflected light 17 whose plane of polarization has been rotated enters the light splitter 13 again and is diffracted by the diffraction grating 15. This diffracted light 2
2 is guided through repeated total reflection on the upper surface of the parallel plate 14 or the lower surface of the parallel plate 16, and the 0 diffracted light 22 that enters the photodetector 23 via the analyzer 21 is the information recorded on the recording surface 20. Since the plane of polarization is rotated in accordance with the information recorded on the recording surface 20 by the analyzer 21, the change in light amount is converted into a change in light amount corresponding to the information recorded on the recording surface 20, and the change in light amount is converted into an electrical signal by the photodetector 23. .
このように、先に提案の光ヘッド装置は小型軽量なもの
であるが、省スペース化の点から光源等も含めて更に薄
型化された構成が望まれていた。As described above, the previously proposed optical head device is small and lightweight, but from the viewpoint of space saving, there has been a desire for a thinner structure including the light source and the like.
一方、前述の光ヘッド装置の光源として用いられる半導
体レーザは、良く知られているようにp−n接合面に平
行な方向と垂直な方向で出射される光束の発散角が異な
り、光束の断面形状は通常楕円形である。このような光
束を記録媒体上に集光させると、光量分布の偏りから記
録、再生の効率が低下する場合があった。On the other hand, in the semiconductor laser used as the light source of the above-mentioned optical head device, as is well known, the divergence angle of the light beam emitted in the direction parallel to and perpendicular to the p-n junction surface is different, and the cross section of the light beam is different. The shape is usually oval. When such a light beam is focused onto a recording medium, the efficiency of recording and reproduction may be lowered due to a bias in the light amount distribution.
本発明の目的は、小型・簡単な構成で、ビーム整形の機
能を有する光ヘッド装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide an optical head device that has a small and simple configuration and has a beam shaping function.
本発明の他の目的は、小型・軽量で、更にfIj型化に
適した光ヘッド装置を提供することにある。Another object of the present invention is to provide an optical head device that is small, lightweight, and suitable for fIj type.
本発明の上記目的は、光ヘッド装置を、光源と、前記光
源から発した光束を光学的記録媒体上に集光する集光手
段と、前記光束の記録媒体からの反射光を検出する光検
出器と、前記光源から記録媒体に入射する光束の光路中
に、該入射光束の光軸にほぼ垂直な面に沿って配列され
た回折格子を有し、前記記録媒体からの反射光を前記回
折格子で回折せしめて前記光検出器に導く光分割器と、
前記光分割器と一体に形成され前記光源からの光束を偏
向して記録媒体に導くプリズムとから構成することによ
って達成される。The above-mentioned object of the present invention is to provide an optical head device including a light source, a condensing means for condensing a luminous flux emitted from the light source onto an optical recording medium, and a photodetector for detecting reflected light of the luminous flux from the recording medium. and a diffraction grating arranged along a plane substantially perpendicular to the optical axis of the incident light beam in the optical path of the light beam incident on the recording medium from the light source, and diffracting the light reflected from the recording medium. a light splitter that diffracts the light with a grating and guides the light to the photodetector;
This is achieved by comprising a prism that is formed integrally with the light splitter and deflects the light beam from the light source and guides it to the recording medium.
以下、本発明の実施例を図面を用いて説明する。尚、以
下の実施例において、第6図の装置と同一の部材には同
一の符号を付した。Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same members as those in the apparatus shown in FIG. 6 are given the same reference numerals.
第1図に、本発明の第1の実施例を示す、半導体レーザ
11から射出された光束はコリメータレンズ12により
平行光束となり、光分割器33に入射する。光分割器3
3は、平行平板16、平行平板16上に形成された回折
格子15及びこの回折格子15のカバーガラスを兼ねた
ビーム整形プリズム34とから構成される。そして、半
導体レーザ11からの光束はこのプリズム34によって
断面形状が回転対称となるようにして偏向され、回折格
子15に垂直に入射する0回折格子15は、金型を機械
的に加工、あるいはホログラフィックにレリーフパター
ンを形成した金型のレリーフコピーにより作られる。ま
ず、平行平板16に紫外線硬化型樹脂層を介して前記金
型を圧着する0次に、紫外線を照射することにより、平
行平板16上にレリーフ格子を形成し、このレリーフ格
子上に適当な特性を有する偏光膜を形成した後、コピー
に用いたのと同一、あるいは同等の屈折率を有する接着
剤を用いて、プリズム34を接着する。FIG. 1 shows a first embodiment of the present invention. A light beam emitted from a semiconductor laser 11 is turned into a parallel light beam by a collimator lens 12, and enters a light splitter 33. light splitter 3
3 is composed of a parallel flat plate 16, a diffraction grating 15 formed on the parallel flat plate 16, and a beam shaping prism 34 which also serves as a cover glass for the diffraction grating 15. The light beam from the semiconductor laser 11 is deflected by the prism 34 so that its cross-sectional shape is rotationally symmetrical, and the zero diffraction grating 15, which is incident perpendicularly to the diffraction grating 15, is formed by mechanically processing a mold or by using a hologram. It is made by copying the relief of a mold with a graphic relief pattern. First, the mold is pressure-bonded to the parallel plate 16 through an ultraviolet curable resin layer.Next, a relief grating is formed on the parallel plate 16 by irradiation with ultraviolet rays, and appropriate characteristics are applied to the relief grating. After forming the polarizing film having the same or similar refractive index, the prism 34 is bonded using an adhesive having the same or similar refractive index to that used for copying.
このレリーフコピーに用いられる接着剤は、紫外線硬化
型のほかに、エポキシ樹脂等の熱硬化型のものや、X線
硬化型も使用できる。また、このようなレリーフ型に限
らず、前述の本出願人の先願に記載された体積型ホログ
ラムも同様に使用可能である。As the adhesive used for this relief copy, in addition to an ultraviolet curing adhesive, a thermosetting adhesive such as an epoxy resin, or an X-ray curing adhesive can also be used. In addition, the hologram is not limited to such a relief type, and the volume type hologram described in the above-mentioned earlier application of the present applicant can also be used.
ビーム整形プリズム34により略回転対称となった光束
は、回折格子15、平行平板16を透過し、対物レンズ
18を介して、基板19に形成された情報記録担体20
上にスポットを生じる。The light beam, which has become approximately rotationally symmetrical due to the beam shaping prism 34, passes through the diffraction grating 15 and the parallel plate 16, and passes through the objective lens 18 to the information recording carrier 20 formed on the substrate 19.
Causes spots on the top.
情報記録担体20より反射され、情報を含んだ光束は、
対物レンズ18を通って平行光束となり、平行平板16
に入射した後、回折格子15により回折され、平行平板
16中を全反射しながら光束22となって導かれ、検光
子21を通って光検出器23に入射する。The light beam reflected from the information recording carrier 20 and containing information is
It passes through the objective lens 18 and becomes a parallel light beam, and the parallel plate 16
After being incident on the light beam, it is diffracted by the diffraction grating 15 and guided as a light beam 22 while being totally reflected in the parallel plate 16 , passes through the analyzer 21 and enters the photodetector 23 .
情報記録担体20には情報が磁気的に記録されており、
媒体の上向!l磁化、下向き磁化の方向に応じて、入射
光には異った方向へのカー回転を生じ、この偏光状態の
差が検光子21により光の強度差となって検出される。Information is magnetically recorded on the information recording carrier 20,
Media upwards! Depending on the direction of l magnetization and downward magnetization, the incident light undergoes Kerr rotation in different directions, and this difference in polarization state is detected by the analyzer 21 as a difference in light intensity.
また、光検出器23からの出力よりフォーカス誤差及び
トラッキング誤差の検出も可能である。Furthermore, it is also possible to detect focus errors and tracking errors from the output from the photodetector 23.
この例を第2図を用いて説明する。This example will be explained using FIG. 2.
第2図は光分割器33を半導体レーザ11側から見た図
で、回折格子15は異った位置に中心を持つ駒格子1t
2a、112b、113に分割されている。格子113
により回折された光束は、二分割の光検出器114に入
射する。FIG. 2 is a diagram of the light splitter 33 seen from the semiconductor laser 11 side, and the diffraction grating 15 has a piece grating 1t with centers at different positions.
It is divided into 2a, 112b, and 113. Lattice 113
The light beam diffracted by the beam enters the two-split photodetector 114.
情報記録担体20が基準位置より遠いか近いかにより、
反射光束は発散あるいは収束となる。このため、回折光
束が光検出器に入射する位置が移動する。従って、光検
出器114からの出力、IAとIBとの差をとることに
より、フォーカスエラー信号が検出できる。Depending on whether the information recording carrier 20 is farther or closer to the reference position,
The reflected light beam is either divergent or convergent. Therefore, the position where the diffracted light beam enters the photodetector moves. Therefore, by taking the difference between the outputs from the photodetector 114, IA and IB, a focus error signal can be detected.
一方、駒格子112a、112bからの光束は光検出器
115,116に夫々入射する。今、情報記録担体の基
板19上に形成されている溝が第2図のAXの方向に配
置されていると溝による光の回折により、112a、1
12bに入射する光量のバランスがくずれる。従って、
光検出器115.116からの出力IC,IDの差をと
ることにより、トラッキング誤差が検出できる。On the other hand, the light beams from the piece gratings 112a and 112b enter photodetectors 115 and 116, respectively. Now, if the grooves formed on the substrate 19 of the information recording carrier are arranged in the direction of AX in FIG.
The balance of the amount of light incident on 12b is lost. Therefore,
Tracking errors can be detected by taking the difference between the outputs IC and ID from the photodetectors 115 and 116.
第3図は、本発明の第2実施例を示す概略構成図である
6本実施例の光分割器43の基本的構成は、第1図示の
装置と同一であるが、回折格子45がビーム整形プリズ
ム44の底面をインジェクション或いはコンプレッショ
ン技術を用いて、凹凸形状に加工することによって形成
されている点で異る。この凹凸面には、適当な反射膜が
形成された後、プリズム44とほぼ同一の屈折率を有す
る接着剤46を介して平行平板16が接合される。FIG. 3 is a schematic configuration diagram showing a second embodiment of the present invention.6 The basic configuration of the light splitter 43 of this embodiment is the same as that of the device shown in FIG. 1, but the diffraction grating 45 The difference is that the bottom surface of the shaping prism 44 is formed by processing the bottom surface into an uneven shape using injection or compression technology. After a suitable reflective film is formed on this uneven surface, the parallel plate 16 is bonded to the prism 44 via an adhesive 46 having substantially the same refractive index.
このような構成をとることにより、より少ない工f1数
で、低価格に光ヘッドを構成することが可能となる。By adopting such a configuration, it is possible to construct an optical head at a low cost with a smaller number of man-hours f1.
第4図に本発明の第3の実施例を示す、半導体し〜ザ1
1から射出された光束はコリメータレンズ12により平
行光束となり、折り曲げプリズム47に入射し、反射面
48により曲げられて光分割器13に入射する。プリズ
ム47は光分割器13を構成している第1の平行平板1
4に接着されている。光束は、平行平板14、回折格子
15、平行平板16を透過し、対物レンズ18によって
基板19を介して情報記録担体20に集光される。この
反射光束は、回折格子15で回折されて光束22となり
、検光子21を透過して光検出器23に入射し、情報信
号、フォーカスエラー信号、トラッキングエラー信号等
が検出される。A third embodiment of the present invention is shown in FIG.
The light beam emitted from the light beam 1 becomes a parallel light beam by the collimator lens 12, enters the bending prism 47, is bent by the reflecting surface 48, and enters the light splitter 13. The prism 47 is the first parallel plate 1 constituting the light splitter 13.
It is glued to 4. The light beam passes through the parallel plate 14, the diffraction grating 15, and the parallel plate 16, and is focused by the objective lens 18 onto the information recording carrier 20 via the substrate 19. This reflected light beam is diffracted by the diffraction grating 15 to become a light beam 22, which passes through the analyzer 21 and enters the photodetector 23, where information signals, focus error signals, tracking error signals, etc. are detected.
第5図は、本発明の第4実施例を示す6本実施例は第4
図示の実施例の平行平板14を省略し、プリズム47を
回折格子15のカバーガラスとして光分割器49を構成
したものである。上記第3及び第4の実施例は、光束が
反射面71で90”曲げられ、光ヘッド全体が薄型に構
成できる長所も有している。FIG. 5 shows a fourth embodiment of the present invention.
The parallel plate 14 of the illustrated embodiment is omitted, and the light splitter 49 is constructed by using the prism 47 as a cover glass for the diffraction grating 15. The third and fourth embodiments have the advantage that the light beam is bent by 90'' at the reflecting surface 71, and the entire optical head can be made thin.
本発明の光ヘッド装置は、以上の実施例の他にも種々の
応用が可能である0例えば、記録担体は前述の光磁気記
録に限らず、ピット形成や反射率変化を利用した様々な
担体に利用可能である。この場合、実施例の検光子21
は不:W七なる。The optical head device of the present invention can be applied in various ways in addition to the embodiments described above. For example, the record carrier is not limited to the above-mentioned magneto-optical recording, but can also be applied to various carriers that utilize pit formation or change in reflectance. is available. In this case, the analyzer 21 of the embodiment
Hafu: W seven naru.
以上説明したように、本発明の光ヘッド装置においては
、ビーム整形プリズム或いは光路を折り曲げるプリズム
を、回折格子を用いた光分割器と一体に形成したので、
簡単な構成で記録・再生の高効率化或いは薄型化が可能
になった。As explained above, in the optical head device of the present invention, the beam shaping prism or the prism for bending the optical path is formed integrally with the light splitter using the diffraction grating.
With a simple configuration, it has become possible to increase the efficiency of recording and playback or to make the device thinner.
第1図は本発明の一実施例の構゛成を示す概略図、第2
図は第1図示の光分割器を半導体レーザ側から見た概略
平面図、第3図、第4図及び第5図は夫々本発明の他の
実施例の構成を示す概略図、第6図は本発明を適用でき
る回折格子を用いた光ヘッド装置の構成を示す概略図で
ある。
11−−m−半導体レーザ、12−−−−コリメータレ
ンズ、15−−−一回折格子、16−−−−平行平板、
18−−−一対物レンズ、20−−−一情報記録担体、
23−−−一光検出器、33−−−一光分割器、34−
−−−ビーム整形プリズム。FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, and FIG.
FIG. 1 is a schematic plan view of the light splitter shown in FIG. 1 viewed from the semiconductor laser side, FIGS. 3, 4, and 5 are schematic diagrams showing the configuration of other embodiments of the present invention, and FIG. 1 is a schematic diagram showing the configuration of an optical head device using a diffraction grating to which the present invention can be applied. 11--m-semiconductor laser, 12--collimator lens, 15--single diffraction grating, 16--parallel plate,
18---one objective lens, 20---one information recording carrier,
23---One photodetector, 33---One light splitter, 34-
---Beam shaping prism.
Claims (3)
体上に集光する集光手段と、前記光束の記録媒体からの
反射光を検出する光検出器と、 前記光源から記録媒体に入射する光束の光路中に、該入
射光束の光軸にほぼ垂直な面に沿って配列された回折格
子を有し、前記記録媒体からの反射光を前記回折格子で
回折せしめて前記光検出器に導く光分割器と、前記光分
割器と一体に形成され前記光源からの光束を偏向して記
録媒体に導くプリズムとから成る光ヘッド装置。(1) A light source, a condensing means for condensing the light beam emitted from the light source onto an optical recording medium, a photodetector for detecting reflected light of the light beam from the recording medium, and a light beam from the light source to the recording medium. A diffraction grating is arranged in the optical path of the incident light beam along a plane substantially perpendicular to the optical axis of the incident light beam, and the light reflected from the recording medium is diffracted by the diffraction grating to detect the photodetector. What is claimed is: 1. An optical head device comprising: a light splitter that guides a light beam to a recording medium; and a prism formed integrally with the light splitter that deflects a light beam from the light source and guides it to a recording medium.
させるビーム整形プリズムである特許請求の範囲第1項
記載の光ヘッド装置。(2) The optical head device according to claim 1, wherein the prism is a beam shaping prism that changes the cross-sectional shape of the light beam from the light source.
加工して成る特許請求の範囲第1項記載の光ヘッド装置
。(3) The optical head device according to claim 1, wherein the diffraction grating is formed by processing one surface of the prism into an uneven shape.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60129482A JPS61289544A (en) | 1985-06-14 | 1985-06-14 | Optical head device |
US06/748,342 US4733065A (en) | 1984-06-27 | 1985-06-24 | Optical head device with diffraction grating for separating a light beam incident on an optical recording medium from a light beam reflected therefrom |
FR8509716A FR2566953A1 (en) | 1984-06-27 | 1985-06-26 | Optical head device |
DE19853522849 DE3522849A1 (en) | 1984-06-27 | 1985-06-26 | OPTICAL HEAD |
NL8501857A NL194898C (en) | 1984-06-27 | 1985-06-27 | Optical reader. |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60129482A JPS61289544A (en) | 1985-06-14 | 1985-06-14 | Optical head device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS61289544A true JPS61289544A (en) | 1986-12-19 |
Family
ID=15010572
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60129482A Pending JPS61289544A (en) | 1984-06-27 | 1985-06-14 | Optical head device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61289544A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0283002A2 (en) * | 1987-03-17 | 1988-09-21 | Matsushita Electric Industrial Co., Ltd. | Optical head |
JPH01303638A (en) * | 1988-05-31 | 1989-12-07 | Matsushita Electric Ind Co Ltd | Optical pickup device |
US6806950B2 (en) | 2001-05-25 | 2004-10-19 | Leica Microsystems Heidelberg Gmbh | Apparatus for determining a light power level, microscope, and method for microscopy |
-
1985
- 1985-06-14 JP JP60129482A patent/JPS61289544A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0283002A2 (en) * | 1987-03-17 | 1988-09-21 | Matsushita Electric Industrial Co., Ltd. | Optical head |
JPH01303638A (en) * | 1988-05-31 | 1989-12-07 | Matsushita Electric Ind Co Ltd | Optical pickup device |
US6806950B2 (en) | 2001-05-25 | 2004-10-19 | Leica Microsystems Heidelberg Gmbh | Apparatus for determining a light power level, microscope, and method for microscopy |
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