JPH10255317A - Optical disk device - Google Patents

Optical disk device

Info

Publication number
JPH10255317A
JPH10255317A JP9076741A JP7674197A JPH10255317A JP H10255317 A JPH10255317 A JP H10255317A JP 9076741 A JP9076741 A JP 9076741A JP 7674197 A JP7674197 A JP 7674197A JP H10255317 A JPH10255317 A JP H10255317A
Authority
JP
Japan
Prior art keywords
laser
light
polarizing
information recording
recording medium
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
Application number
JP9076741A
Other languages
Japanese (ja)
Inventor
Masahiko Nakayama
昌彦 中山
Original Assignee
Ricoh Co Ltd
株式会社リコー
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 Ricoh Co Ltd, 株式会社リコー filed Critical Ricoh Co Ltd
Priority to JP9076741A priority Critical patent/JPH10255317A/en
Publication of JPH10255317A publication Critical patent/JPH10255317A/en
Pending legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To enable change and separation in an optical path without unnecessarily attenuating the light quantity of a laser beam, in recording and reproducing information for a disk having a different substrate thickness. SOLUTION: The device is set so that a semiconductor laser 1 emits a laser beam with a λ1 wavelength and S polarization, that a semiconductor laser 2 emits a laser beam with a λ2 wavelength and S polarization, and that λ1 is longer than λ2. In addition, in the optical path between an objective lens 5 and a photodetector 10, a polarizing beam splitter 3 for CD is arranged that reflects nearly 100% of the laser beam entered from the semiconductor laser 1 and that transmits nearly 100% of other laser beams, as is a wide-band polarizing beam splitter 7 that reflects nearly 100% of the laser beam entered from the semiconductor laser 2 and that transmits nearly 100% of other laser beams. As a result, the light quantity is reduced that quantity is attenuated at the time of change and separation in the optical path of the laser beam.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は,レーザ源から出射
されるレーザ光の光量を有効に利用しながら,基板厚が
異なる情報記録媒体に対して記録再生可能にした光ディ
スク装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus capable of recording / reproducing information on / from information recording media having different substrate thicknesses while effectively utilizing the amount of laser light emitted from a laser source.

【0002】[0002]

【従来の技術】今日,ディスクの記録密度を高めたいと
の要請から種々研究開発が行われ,1つの標準として,
いわゆるDVDなるものが提案されている。当該DVD
は,従来から使用されているディスクより基板厚が薄
く,かつ,高記録密度が可能になっている。
2. Description of the Related Art Today, various researches and developments have been made in response to a demand for increasing the recording density of a disk.
A so-called DVD has been proposed. The DVD
Has a substrate thickness smaller than that of a conventionally used disk, and enables a high recording density.

【0003】そして,従来のディスクとDVDで代表さ
れるディスクとに対して再生等が共に行えるようにした
光ピックアップ装置として特開平6−259804号公
報にかかるものがある。なお,以下の説明においては,
ディスクの基板厚が厚い従来のディスクをCDと記載
し,当該ディスク(CD)より基板厚が薄く記録密度の
高いディスクをDVDと記載する。
[0003] Japanese Patent Application Laid-Open No. 6-259804 discloses an optical pickup device capable of performing both reproduction and the like on a conventional disk and a disk represented by a DVD. In the following explanation,
A conventional disk having a large disk substrate thickness is referred to as a CD, and a disk having a smaller substrate thickness and a higher recording density than the disk (CD) is referred to as a DVD.

【0004】図9は当該公報にかかる光ピックアップ装
置の光学系を示したものである。同図にかかる光ディス
ク装置において,CD6を再生する時は,半導体レーザ
1から出射された波長λ=780nmのS偏光のレーザ
光をコリメートレンズ2により平行光又は発散光に変換
して広帯域偏光ビームスプリッタ7に入射させる。
FIG. 9 shows an optical system of an optical pickup device according to the publication. In reproducing the CD 6 in the optical disk apparatus according to the figure, the S-polarized laser light having a wavelength λ = 780 nm emitted from the semiconductor laser 1 is converted into parallel light or divergent light by the collimating lens 2 and is broadband polarized beam splitter. 7 is incident.

【0005】これによりレーザ光は,当該広帯域偏光ビ
ームスプリッタ7で反射されてハーフミラー26に入射
し,当該ハーフミラー26で反射されて対物レンズ5に
入射する。当該対物レンズ5に入射したレーザ光は,集
光されてCD6に照射される。
Accordingly, the laser light is reflected by the broadband polarization beam splitter 7 and enters the half mirror 26, and is reflected by the half mirror 26 and enters the objective lens 5. The laser light incident on the objective lens 5 is condensed and irradiated on the CD 6.

【0006】また,CD6からの反射光は,対物レンズ
5,ハーフミラー26,集光レンズ8,シリンドリカル
レンズ9を介し,広帯域偏光ビームスプリッタ27で反
射され,CD用の受光素子15で受光されてCD6の再
生が行なわれる。
The reflected light from the CD 6 is reflected by the broadband polarization beam splitter 27 via the objective lens 5, the half mirror 26, the condenser lens 8, and the cylindrical lens 9, and is received by the light receiving element 15 for CD. The reproduction of CD6 is performed.

【0007】一方,DVD13を再生する時は,半導体
レーザ11から出射された波長λ=650nmのP偏光
のレーザ光をコリメートレンズ12で平行光にし,広帯
域偏光ビームスプリッタ7を透過させてハーフミラー2
6で反射する。その後,対物レンズ5に入射し,当該対
物レンズ5により集光されてDVD13に照射される。
On the other hand, when the DVD 13 is reproduced, the P-polarized laser light having a wavelength of λ = 650 nm emitted from the semiconductor laser 11 is made parallel by the collimating lens 12 and transmitted through the wide-band polarization beam splitter 7 to form the half mirror 2.
The light is reflected at 6. Thereafter, the light enters the objective lens 5, is condensed by the objective lens 5, and is irradiated on the DVD 13.

【0008】また,DVD13からの反射光は,対物レ
ンズ5,ハーフミラー26,集光レンズ8,シリンドリ
カルレンズ9を介し,広帯域偏光ビームスプリッタ27
を透過して,DVD用の受光素子16で受光されてDV
D13の再生が行なわれる。なお,広帯域偏光ビームス
プリッタ27は,広帯域偏光ビームスプリッタ7と同じ
構成のものである。
The reflected light from the DVD 13 passes through an objective lens 5, a half mirror 26, a condenser lens 8, and a cylindrical lens 9, and passes through a broadband polarization beam splitter 27.
And received by the light receiving element 16 for DVD,
D13 is reproduced. The broadband polarization beam splitter 27 has the same configuration as the wideband polarization beam splitter 7.

【0009】[0009]

【発明が解決しようとする課題】しかしながら,上記構
成の光学系では,ハーフミラー26により光路の変更等
を行うが,その際当該ハーフミラー26でレーザ光の光
量が半減してしまう不都合がある。このため,特に記録
時において,高価な高出力の半導体レーザを使う必要が
生じ,また再生信号のS/Nが低下する問題があった。
However, in the optical system having the above-described structure, the optical path is changed by the half mirror 26, but there is a disadvantage that the light quantity of the laser beam is reduced by half at the half mirror 26. For this reason, especially at the time of recording, it is necessary to use an expensive high-output semiconductor laser, and there is a problem that the S / N of a reproduction signal is reduced.

【0010】そこで,本発明は,光学系の光路中にハー
フミラーを使わずに効率の良い光学系を提供することを
目的とする。
Accordingly, an object of the present invention is to provide an efficient optical system without using a half mirror in the optical path of the optical system.

【0011】[0011]

【課題を解決するための手段】請求項1にかかる発明
は,基板厚の厚い第1情報記録媒体と当該第1情報記録
媒体より基板厚が薄い第2記録媒体とにそれぞれ適応し
た波長のレーザ光を出射する第1及び第2レーザ源から
なるレーザ発生手段と,該レーザ発生手段からのレーザ
光を集光して第1又は第2情報記録媒体に照射する対物
レンズと,第1又は第2情報記録媒体からの反射光を受
光して再生信号を出力する受光手段とを有した光ディス
ク装置において,第1レーザ源は,波長がλ1でS偏光
のレーザ光を出射し,第2レーザ源は,波長がλ2でS
偏光のレーザ光を出射し,かつ,λ1>λ2になるよう
に設定され,対物レンズと受光手段との光路中に,第1
レーザ源から入射したレーザ光を略100%反射し,そ
の他のレーザ光は略100%透過させる第1偏光手段と
第2レーザ源から入射したレーザ光を略100%反射
し,その他のレーザ光は略100%透過させる第2偏光
手段とを配設して,レーザ光の光量減衰を防止したこと
を特徴とする。
According to the first aspect of the present invention, there is provided a laser having a wavelength adapted to a first information recording medium having a thicker substrate and a second recording medium having a smaller substrate thickness than the first information recording medium. A laser generating means comprising first and second laser sources for emitting light, an objective lens for condensing laser light from the laser generating means and irradiating the first or second information recording medium with the first or second laser; (2) In an optical disk apparatus having light receiving means for receiving reflected light from an information recording medium and outputting a reproduction signal, a first laser source emits S-polarized laser light having a wavelength of λ1, and a second laser source. Is S at wavelength λ2
The laser beam is emitted so as to be polarized light, and is set so that λ1> λ2.
A laser beam incident from a laser source is reflected by approximately 100%, and other laser beams are transmitted by approximately 100%. A first polarizing means and a laser beam incident from a second laser source are reflected by approximately 100%. A second polarizing means for transmitting substantially 100% is provided to prevent the light quantity of the laser beam from attenuating.

【0012】請求項2にかかる発明は,対物レンズと受
光手段との間に,第1情報記録媒体からの反射光のみを
反射して第1及び第2情報記録媒体からの反射光の光路
を分離する第3偏光手段が配設され,かつ,受光手段を
第3偏光手段で反射された第1情報記録媒体からの反射
光を受光する第1受光素子と,第3偏光手段を透過した
第2情報記録媒体からの反射光を受光する第2受光素子
とから構成して,第1及び第2情報記録媒体に対して適
切な再生信号を得るようにしたことを特徴とする。
According to a second aspect of the present invention, the optical path of the reflected light from the first and second information recording media is reflected between the objective lens and the light receiving means by reflecting only the reflected light from the first information recording medium. A third polarizing means for separating light is provided, and the light receiving means is a first light receiving element for receiving the reflected light from the first information recording medium reflected by the third polarizing means, and a third light receiving element for transmitting the third polarized light. And (2) a second light receiving element for receiving light reflected from the information recording medium so as to obtain an appropriate reproduction signal for the first and second information recording media.

【0013】請求項3にかかる発明は,第1レーザ源か
らのレーザ光を絞る第1アパーチャ手段と,第2レーザ
源からのレーザ光を絞る第2アパーチャ手段とが設けら
れて,対物レンズの開口数を第1及び第2情報記録媒体
に適した開口数にして,球面収差等の発生を防止したこ
とを特徴とする。
According to a third aspect of the present invention, there is provided a first aperture means for narrowing a laser beam from a first laser source, and a second aperture means for narrowing a laser beam from a second laser source. The numerical aperture is set to a numerical aperture suitable for the first and second information recording media to prevent occurrence of spherical aberration and the like.

【0014】請求項4にかかる発明は,第1及び第2偏
光手段又は第1乃至第3偏光手段が,透明部材を挟んで
一体に積層されて形成された平行四辺形状のプリズムを
用いて部品点数等を削減すると共に,製造を容易にした
ことを特徴とする。
According to a fourth aspect of the present invention, there is provided a component using a parallelogram prism formed by laminating the first and second polarizing means or the first to third polarizing means integrally with a transparent member interposed therebetween. The feature is that the number of points etc. has been reduced and the production has been simplified.

【0015】請求項5にかかる発明は,プリズムにおけ
る,第1及び第2偏光手段又は第1乃至第3偏光手段の
配設面と平行な面にサーボ信号発生手段が形成されて,
部品点数等を削減すると共に,製造を容易にしたことを
特徴とする。
According to a fifth aspect of the present invention, in the prism, the servo signal generating means is formed on a surface parallel to the surface on which the first and second polarizing means or the first to third polarizing means are provided.
It is characterized by reducing the number of parts and facilitating manufacture.

【0016】請求項6にかかる発明は,第1レーザ源が
出射するレーザ光の波長λ1を780〜830nmの範
囲に設定し,かつ,第2レーザ源が出射するレーザ光の
波長λ2を635〜685nmの範囲に設定して,第1
及び第2情報記録媒体に対して適切な波長で情報の記録
再生を可能にしたことを特徴とする。
According to a sixth aspect of the present invention, the wavelength λ1 of the laser beam emitted from the first laser source is set in the range of 780 to 830 nm, and the wavelength λ2 of the laser beam emitted from the second laser source is set to 635 to 635 nm. 685 nm, the first
And recording and reproduction of information at an appropriate wavelength with respect to the second information recording medium.

【0017】[0017]

【発明の実施の形態】本発明の第1の実施の形態を図を
参照して説明する。なお,従来の構成と同一構成に関し
ては同一符号を用い,説明を適宜省略する。図1は,本
実施の形態にかかる光ディスク装置の光学系を示したも
のである。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. Note that the same reference numerals are used for the same configuration as the conventional configuration, and the description will be appropriately omitted. FIG. 1 shows an optical system of an optical disk device according to the present embodiment.

【0018】CD6の再生時には,半導体レーザ1から
波長λ=780nmのS偏光のレーザ光が出射され,コ
リメートレンズ2で平行光又は発散光となり,780n
m用の偏光ビームスプリッタ3で反射され,λ/4板4
で円偏光となる。そして,対物レンズ5により集光され
て,CD6に照射される。なお,以下偏光ビームスプリ
ッタ3をCD用PBS3と記載する。
At the time of reproduction of the CD 6, an S-polarized laser beam having a wavelength λ = 780 nm is emitted from the semiconductor laser 1, and is converted into a parallel beam or a divergent beam by the collimator lens 2, and 780n
reflected by the polarizing beam splitter 3 for m.
Becomes circularly polarized light. Then, the light is condensed by the objective lens 5 and irradiated on the CD 6. Hereinafter, the polarization beam splitter 3 is referred to as a CD PBS 3.

【0019】CD6からの反射光は,対物レンズ5を介
し,λ/4板4でP偏光となり,CD用PBS3を透過
し,広帯域偏光ビームスプリッタ7を透過し,集光レン
ズ8,シリンドリカルレンズ9を介し,受光素子10で
受光されて再生が行われる。以下,広帯域偏光ビームス
プリッタ7を広帯域PBS7と記載する。
The reflected light from the CD 6 passes through the objective lens 5, becomes P-polarized light by the λ / 4 plate 4, passes through the CD PBS 3, passes through the broadband polarization beam splitter 7, and collects the condensing lens 8 and the cylindrical lens 9. , The light is received by the light receiving element 10 and reproduction is performed. Hereinafter, the broadband polarization beam splitter 7 is referred to as a broadband PBS 7.

【0020】一方,DVD13の再生時には,半導体レ
ーザ11から波長λ=650nmのS偏光のレーザ光が
出射され,コリメートレンズ12で平行光となり広帯域
PBS7により反射されて,CD用PBS3を透過し,
λ/4板4で円偏光となる。そして,対物レンズ5によ
り集光されて,DVD13に照射される。
On the other hand, when the DVD 13 is reproduced, an S-polarized laser beam having a wavelength λ = 650 nm is emitted from the semiconductor laser 11, becomes parallel light at the collimating lens 12, is reflected by the broadband PBS 7, and passes through the CD PBS 3.
The light becomes circularly polarized light by the λ / 4 plate 4. Then, the light is condensed by the objective lens 5 and irradiated on the DVD 13.

【0021】DVD13からの反射光は,対物レンズ5
を介し,λ/4板4でP偏光となり,CD用PBS3及
び広帯域PBS7を透過し,集光レンズ8,シリンドリ
カルレンズ9を介して受光素子10で受光されて再生が
行われる。
The reflected light from the DVD 13 passes through the objective lens 5
The light is converted into P-polarized light by the λ / 4 plate 4, passes through the CD PBS 3 and the broadband PBS 7, is received by the light receiving element 10 through the condenser lens 8 and the cylindrical lens 9, and is reproduced.

【0022】図4は,CD用PBS3における分光特性
を示したもので,波長λ=780nmの近傍のレーザ光
に対して,P偏光のレーザ光は略100%透過するが,
S偏光のレーザ光は略100%反射される。
FIG. 4 shows the spectral characteristics of the PBS 3 for a CD. In the case of a laser beam having a wavelength near λ = 780 nm, approximately 100% of a P-polarized laser beam is transmitted.
S-polarized laser light is reflected almost 100%.

【0023】一方,波長λ=650nmの近傍のレーザ
光に対しては,P偏光及びS偏光のいずれの偏光状態で
あっても略100%透過する。
On the other hand, almost 100% of the laser light having a wavelength of λ = 650 nm is transmitted regardless of the polarization state of either P-polarized light or S-polarized light.

【0024】また図5は,広帯域PBS7における分光
特性を示したものである。波長λ=780nm及び波長
λ=650nmの近傍のレーザ光に対して,P偏光のレ
ーザ光は略100%透過するが,S偏光のレーザ光は略
100%反射される。
FIG. 5 shows the spectral characteristics of the broadband PBS 7. With respect to the laser light near the wavelengths λ = 780 nm and λ = 650 nm, the P-polarized laser light is transmitted by approximately 100%, while the S-polarized laser light is reflected by approximately 100%.

【0025】従って,このような特性を持つCD用PB
S3及び広帯域PBS7を用いることにより,従来のよ
うに反射と透過が50%ずつのハーフミラーを用いる場
合に比べレーザ光の利用効率が向上し,半導体レーザの
出力が小さくて済むようになる。これにより安価な半導
体レーザを使用することが可能になり,また受光素子に
入射する反射光の光量が多いので,情報の再生を正確に
行うことが可能になる。
Therefore, a PB for CD having such characteristics
By using the S3 and the broadband PBS 7, the use efficiency of the laser light is improved and the output of the semiconductor laser can be reduced as compared with the case where a half mirror having 50% reflection and 50% transmission as in the related art is used. As a result, an inexpensive semiconductor laser can be used, and the amount of reflected light incident on the light receiving element is large, so that information can be accurately reproduced.

【0026】次に本発明にかかる第2の実施の形態を図
を参照して説明する。なお,第1の実施の形態と同一構
成に関しては,同一符号を付して説明を適宜省略する。
Next, a second embodiment according to the present invention will be described with reference to the drawings. The same components as those of the first embodiment are denoted by the same reference numerals, and the description will be appropriately omitted.

【0027】図2は,本実施の形態にかかる光学系を示
す図で,図1と略同じ構成であるが,シリンドリカルレ
ンズ9と受光素子10との間に650nm用の偏光ビー
ムスプリッタ14が配設され,さらに受光素子10がD
VD用の受光素子16に変更されると共に,偏光ビーム
スプリッタ14で反射されたレーザ光を受光するCD用
受光素子15が配設されている点が相違している。な
お,以下の説明においては,650nm用の偏光ビーム
スプリッタ14をDVD用PBS14と記載する。
FIG. 2 is a view showing an optical system according to the present embodiment, which has substantially the same configuration as that of FIG. 1, except that a polarizing beam splitter 14 for 650 nm is disposed between the cylindrical lens 9 and the light receiving element 10. And the light receiving element 10 is D
The difference is that the light receiving element 16 is replaced with a light receiving element 16 for VD and a light receiving element 15 for CD which receives the laser beam reflected by the polarization beam splitter 14 is provided. In the following description, the polarizing beam splitter 14 for 650 nm is referred to as a DVD PBS 14.

【0028】そして,CD6の再生時には,半導体レー
ザ1から出射されたS偏光のレーザ光は,コリメートレ
ンズ2で平行光又は発散光となり780nm用PBS3
で反射され,λ/4板4で円偏光となる。その後,対物
レンズ5により集光されてCD6に照射される。
When reproducing the CD 6, the S-polarized laser light emitted from the semiconductor laser 1 is converted into parallel light or divergent light by the collimator lens 2, and the 780 nm PBS 3 is used.
And is converted into circularly polarized light by the λ / 4 plate 4. Thereafter, the light is condensed by the objective lens 5 and is irradiated on the CD 6.

【0029】CD6からの反射光は,対物レンズ5を介
し,λ/4板4でP偏光となり,CD用PBS3を透過
し,広帯域PBS7を透過し,集光レンズ8,シリンド
リカルレンズ9を介し,DVD用PBS14で反射され
て,CD用受光素子15で受光される。これによりCD
6の再生が行われる。
The reflected light from the CD 6 passes through the objective lens 5, becomes P-polarized light by the λ / 4 plate 4, passes through the CD PBS 3, passes through the broadband PBS 7, passes through the condenser lens 8, the cylindrical lens 9, The light is reflected by the DVD PBS 14 and received by the CD light receiving element 15. This is CD
6 is performed.

【0030】一方,DVD13の再生時には,半導体レ
ーザ11から出射されたS偏光のレーザ光は,コリメー
トレンズ12で平行光となり広帯域PBS7で反射さ
れ,CD用PBS3を透過して,λ/4板4で円偏光と
なる。そして,対物レンズ5により集光されてDVD1
3に照射される。
On the other hand, when the DVD 13 is reproduced, the S-polarized laser light emitted from the semiconductor laser 11 is converted into parallel light by the collimating lens 12, reflected by the broadband PBS 7, transmitted through the CD PBS 3, and transmitted to the λ / 4 plate 4. Becomes circularly polarized light. Then, the light is collected by the objective lens 5 and the DVD 1
3 is irradiated.

【0031】DVD13からの反射光は,対物レンズ5
を介し,λ/4板4でP偏光となり,CD用PBS3を
透過し,広帯域PBS7,集光レンズ8,シリンドリカ
ルレンズ9,DVD用PBS14を順次透過して,DV
D用受光素子16で受光される。これによりDVD13
の再生が行なわれる。
The reflected light from the DVD 13 passes through the objective lens 5
Through the λ / 4 plate 4 to become P-polarized light, pass through the CD PBS 3, sequentially pass through the broadband PBS 7, the condenser lens 8, the cylindrical lens 9, and the DVD PBS 14, and
The light is received by the D light receiving element 16. With this, DVD13
Is reproduced.

【0032】図6は,DVD用PBS14の分光特性を
示したものである。波長λ=650nmの近傍のレーザ
光に対しては,P偏光のレーザ光は,略100%透過
し,S偏光のレーザ光は,略100%反射する。
FIG. 6 shows the spectral characteristics of the PBS 14 for DVD. With respect to the laser light near the wavelength λ = 650 nm, approximately 100% of the P-polarized laser light is transmitted, and approximately 100% of the S-polarized laser light is reflected.

【0033】一方,波長λ=780nmの近傍のレーザ
光に対しては,P偏光でもS偏光でも略100%のレー
ザ光が反射される。
On the other hand, for a laser beam having a wavelength near λ = 780 nm, approximately 100% of the laser beam is reflected by both P-polarized light and S-polarized light.

【0034】従って,このような特性を持つ,CD用P
BS3,広帯域PBS7及びDVD用PBS14を用い
ることにより,従来のように反射と透過が50%ずつの
ハーフミラーを用いる場合に比べレーザ光の利用効率が
向上するため,半導体レーザの出力が小さくて済むよう
になる。このことは,安価な半導体レーザの使用を可能
にし,また受光素子に入射する反射光の光量が多いの
で,情報の再生を正確に行うことが可能になる。
Accordingly, a P for CD having such characteristics
By using the BS3, the broadband PBS7, and the DVD PBS14, the use efficiency of the laser beam is improved as compared with the case of using a half mirror having 50% reflection and transmission, as in the related art, so that the output of the semiconductor laser can be reduced. Become like This makes it possible to use an inexpensive semiconductor laser, and since the amount of reflected light incident on the light receiving element is large, it is possible to accurately reproduce information.

【0035】次に本発明にかかる第3の実施の形態を図
を参照して説明する。この際,第1,2の実施の形態と
同一構成に関しては,同一符号を付して説明を適宜省略
する。
Next, a third embodiment according to the present invention will be described with reference to the drawings. At this time, the same components as those of the first and second embodiments are denoted by the same reference numerals, and the description will be appropriately omitted.

【0036】CD6は基板の厚さが1.2mmであり,
DVD13は基板の厚さが0.6mmである。従って,
これら2種類のディスクを同一の対物レンズで再生等行
うためには,例えばCD用の半導体レーザ1からのS偏
光のレーザ光をコリメートレンズ2を透過させて発散光
としたり,コリメートレンズ2に球面収差補正機能を付
加する必要がある。
CD6 has a substrate thickness of 1.2 mm.
The DVD 13 has a substrate thickness of 0.6 mm. Therefore,
In order to reproduce these two types of disks with the same objective lens, for example, S-polarized laser light from a semiconductor laser 1 for CD is transmitted through a collimating lens 2 to be divergent light, or a spherical surface is formed on the collimating lens 2. It is necessary to add an aberration correction function.

【0037】そこで,本実施の形態にかかる発明は,簡
単な方法でCD6とDVD13とディスクを共に再生等
できるようにする。このような観点から構成された光デ
ィスク装置の光学系が図3である。
Therefore, the invention according to the present embodiment makes it possible to reproduce a CD6, a DVD13 and a disc together with a simple method. FIG. 3 shows an optical system of an optical disk device configured from such a viewpoint.

【0038】図3は,図2の光学系と略同じ構成である
が,コリメートレンズ2の周辺部にCD6を再生する時
に最適となるアパーチャ17を設け,かつ,対物レンズ
5にDVD13を再生する時に最適となるアパーチャ1
8を設けている。
FIG. 3 has substantially the same configuration as that of the optical system shown in FIG. 2. However, an aperture 17 which is optimal when reproducing the CD 6 is provided around the collimator lens 2, and the DVD 13 is reproduced by the objective lens 5. Aperture 1 that is sometimes optimal
8 are provided.

【0039】このように,アパーチャ17,18を設け
ることにより,対物レンズ5の開口数NAを変えること
が可能になる。なお,対物レンズ5を出射するレーザ光
の最適開口数NAは,CD6で0.45〜0.5程度,
DVD13で0.6程度である。
By providing the apertures 17 and 18 in this manner, it is possible to change the numerical aperture NA of the objective lens 5. The optimum numerical aperture NA of the laser beam emitted from the objective lens 5 is about 0.45 to 0.5 for CD6,
It is about 0.6 for DVD13.

【0040】従って,アパーチャ17,18の開口領域
の大きさを,上記最適開口数になるように設定すれば,
厚みの異なる2種類のディスクに対して,コリメートレ
ンズ2によりレーザ光を発散光としたり,当該コリメー
トレンズ2に球面収差補正機能を付加することなく再生
を行うことが可能になる。
Therefore, if the size of the aperture areas of the apertures 17 and 18 is set to be the above-mentioned optimum numerical aperture,
For two types of disks having different thicknesses, reproduction can be performed without using a collimating lens 2 to make laser light divergent or adding a spherical aberration correction function to the collimating lens 2.

【0041】なお,上記説明では,アパーチャ17をコ
リメートレンズ2の周辺部に設け,アパーチャ18を対
物レンズ5に設けた場合について説明したが,本発明は
これに限定されるものではなく,例えばアパーチャ18
をコリメートレンズ12の周辺部に設けてもよく,さら
にはアパーチャ17を半導体レーザ1側のCD用PBS
3の入射面に設けたり,アパーチャ18を半導体レーザ
11側の広帯域PBS7の入射面に設けることも可能で
ある。
In the above description, the case where the aperture 17 is provided on the periphery of the collimator lens 2 and the aperture 18 is provided on the objective lens 5 has been described. However, the present invention is not limited to this. 18
May be provided in the periphery of the collimating lens 12, and the aperture 17 may be provided with a CD PBS for the semiconductor laser 1.
The aperture 18 may be provided on the incident surface of the broadband PBS 7 on the semiconductor laser 11 side.

【0042】次に本発明にかかる第4の実施の形態を図
を参照して説明する。なお,上記第1〜3の実施の形態
と同一構成に関しては,同一符号を付して説明を適宜省
略する。
Next, a fourth embodiment according to the present invention will be described with reference to the drawings. The same components as those in the first to third embodiments are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

【0043】図7は,本実施の形態にかかる光ディスク
装置の光学系を示す図である。CD6の再生時には,半
導体レーザ1から出射されるS偏光のレーザ光は,平行
四辺形のプリズム19に入射し,780nm用PBS膜
20で反射され,平行四辺形のプリズム19の左の斜辺
(図7において,左の斜辺)で反射され,λ/4板4で
円偏光となる。なお,以下の説明においては,780n
m用PBS膜20をCD用PBS膜20と記載する。
FIG. 7 is a diagram showing an optical system of the optical disk device according to the present embodiment. When the CD 6 is reproduced, the S-polarized laser light emitted from the semiconductor laser 1 is incident on the parallelogram prism 19, is reflected by the 780 nm PBS film 20, and is on the left hypotenuse of the parallelogram prism 19 (see FIG. At 7, the light is reflected by the left oblique side) and becomes circularly polarized light by the λ / 4 plate 4. In the following description, 780n
The m-PBS film 20 is referred to as a CD PBS film 20.

【0044】そして,コリメートレンズ23を透過し,
対物レンズ5により集光されてCD6に照射される。な
お,CD用PBS膜20は,CD用PBS3における分
光特性と同じ分光特性を持っている。
Then, the light passes through the collimating lens 23,
The light is condensed by the objective lens 5 and irradiated on the CD 6. The CD PBS film 20 has the same spectral characteristics as those of the CD PBS 3.

【0045】CD6からの反射光は,対物レンズ5,コ
リメートレンズ23を順次透過し,λ/4板4でP偏光
となって平行四辺形のプリズム19の左の斜辺(図7に
おいて,左の斜辺)で反射される。
The reflected light from the CD 6 sequentially passes through the objective lens 5 and the collimating lens 23, becomes P-polarized light by the λ / 4 plate 4, becomes the left oblique side of the parallelogram prism 19 (the left oblique side in FIG. 7). (The hypotenuse).

【0046】そして,CD用PBS膜20を透過し,広
帯域偏光ビームスプリッタ膜(広帯域PBS)膜21を
透過し,平行四辺形のプリズム19の右の斜辺(図7に
おいて,右の斜辺)に設けたグレーティング22で反射
されて,受光素子10で受光される。これにより,CD
の再生が行なわれる。広帯域PBS膜21は,広帯域P
BS7の分光特性と同じ分光特性を持っている。なお,
以下の説明では広帯域偏光ビームスプリッタ膜21を広
帯域PBS膜21と記載する。
Then, the light passes through the CD PBS film 20 and the broadband polarizing beam splitter film (broadband PBS) film 21 and is provided on the right oblique side of the parallelogram prism 19 (the right oblique side in FIG. 7). The light is reflected by the grating 22 and received by the light receiving element 10. With this, CD
Is reproduced. The broadband PBS film 21 has a broadband P
It has the same spectral characteristics as those of BS7. In addition,
In the following description, the broadband polarization beam splitter film 21 is referred to as a broadband PBS film 21.

【0047】一方,DVD13の再生時には,DVD用
の半導体レーザ11から出射されたS偏光のレーザ光
は,平行四辺形のプリズム19に入射し,広帯域PBS
膜21で反射され,そしてCD用PBS膜20を透過
し,平行四辺形のプリズム19の左の斜辺(図7におい
て,左の斜辺)で反射され,λ/4板4で円偏光とな
る。その後,コリメートレンズ23を介して対物レンズ
5により集光されてDVD13に照射される。
On the other hand, at the time of reproducing the DVD 13, the S-polarized laser light emitted from the DVD semiconductor laser 11 enters the parallelogram prism 19, and is broadband PBS.
The light is reflected by the film 21, passes through the CD PBS film 20, is reflected by the left oblique side (the left oblique side in FIG. 7) of the parallelogram prism 19, and becomes circularly polarized light by the λ / 4 plate 4. Thereafter, the light is condensed by the objective lens 5 via the collimator lens 23 and is irradiated on the DVD 13.

【0048】DVD13からの反射光は,対物レンズ5
及びコリメートレンズ23を介し,λ/4板4でP偏光
となり,平行四辺形のプリズム19の左の斜辺(図7に
おいて,左の斜辺)で反射され,CD用PBS膜20及
び広帯域PBS膜21を順次透過し,平行四辺形のプリ
ズム19の右の斜辺(図7において,右の斜辺)に設け
たグレーティング(ホログラム)22で反射されて,受
光素子10で受光される。これによりDVD13の再生
が行われる。
The reflected light from the DVD 13 passes through the objective lens 5
Then, through the collimating lens 23, the light becomes P-polarized light by the λ / 4 plate 4, is reflected by the left oblique side (left oblique side in FIG. 7) of the parallelogram prism 19, and is exposed to the CD PBS film 20 and the broadband PBS film 21. Are sequentially transmitted, reflected by a grating (hologram) 22 provided on the right oblique side (right oblique side in FIG. 7) of the parallelogram prism 19, and received by the light receiving element 10. Thereby, reproduction of the DVD 13 is performed.

【0049】なお,グレーティング22は,非点収差を
発生させるものでも良いし,領域分割タイプのものでも
良い。また,所望のサーボ特性が得られればグレーティ
ングに限らずレンズでもプリズムでも良い。
The grating 22 may be one that generates astigmatism or one that is divided into regions. In addition, a lens or a prism may be used instead of the grating as long as desired servo characteristics can be obtained.

【0050】上述した構成は,図1に示す光学系におけ
る2個のPBSを当該プリズムで代用したが,図2に示
す光学系における3個のPBSを当該プリズムで代用す
ることも可能である。
In the above-described configuration, the two PBSs in the optical system shown in FIG. 1 are substituted by the prisms. However, the three PBSs in the optical system shown in FIG. 2 can be substituted by the prisms.

【0051】図8は,かかるは作用を行う平行四辺形の
プリズム19の製造模式図を示したものである。同図に
おいて,23,24,25はガラス板である。そして,
ガラス板23とガラス板24の間には,広帯域PBS膜
21が蒸着,コーティング等の薄膜形成方法により形成
され,またガラス板24とガラス板25の間には,CD
用PBS膜20が蒸着,コーティング等の薄膜形成方法
により形成されている。さらにガラス板23の上面には
グレーティング22が形成されている。
FIG. 8 is a schematic view showing the manufacture of a parallelogram prism 19 which performs such an operation. In the figure, 23, 24 and 25 are glass plates. And
A broadband PBS film 21 is formed between the glass plates 23 and 24 by a thin film forming method such as vapor deposition and coating.
The PBS film 20 is formed by a thin film forming method such as vapor deposition and coating. Further, a grating 22 is formed on the upper surface of the glass plate 23.

【0052】このように,ガラス板にPBS膜を配設
し,グレーティングを形成した後に,図8にしめす破線
に沿って,斜め方向(点線A)と奥行き方向(点線B)
に切断することにより多数の四辺形のプリズム19が容
易に製造することが可能になる。
As described above, after the PBS film is disposed on the glass plate and the grating is formed, the oblique direction (dotted line A) and the depth direction (dotted line B) are taken along the broken line shown in FIG.
In this way, a large number of quadrangular prisms 19 can be easily manufactured.

【0053】従って,厚みの異なる2種類のディスクに
対して再生を可能にする平行四辺形のプリズムを容易,
かつ,簡易に量産することが可能になる。
Therefore, a parallelogram prism capable of reproducing data from two types of disks having different thicknesses can be easily formed.
In addition, mass production can be easily performed.

【0054】なお,図7及び図8においては,グレーテ
ィング22をアイランド状に形成しているが,本発明は
これに限定されずガラス板23の全面に形成してもよい
ことは言うまでもない。
Although the grating 22 is formed in an island shape in FIGS. 7 and 8, it is needless to say that the present invention is not limited to this and may be formed on the entire surface of the glass plate 23.

【0055】次に,本発明にかかる第5の実施の形態を
説明する。なお,第1〜4の実施の形態と同一構成に関
しては,同一符号を付して説明を適宜省略する。
Next, a fifth embodiment according to the present invention will be described. In addition, about the same structure as 1st-4th embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted suitably.

【0056】CDといっても種々のCDがあり,例えば
再生専用のCDや書き込みが可能なCDがある。特にC
D−Rは,波長λが780〜830nm程度でしか再生
することが出来ないので,CD−Rを再生するためには
半導体レーザ1から出射されるレーザ光の波長がλ=7
80〜830nmである必要がある。一方,DVDの場
合には波長がλ=780〜830nmのときは再生が出
来ないので,λ=635nm〜685nm程度にする必
要がある。
There are various types of CDs, such as a read-only CD and a writable CD. Especially C
Since the DR can be reproduced only when the wavelength λ is about 780 to 830 nm, the wavelength of the laser beam emitted from the semiconductor laser 1 is λ = 7 to reproduce the CD-R.
It needs to be 80 to 830 nm. On the other hand, in the case of DVD, reproduction cannot be performed when the wavelength is λ = 780 to 830 nm, so that it is necessary to set λ to about 635 nm to 685 nm.

【0057】そこで,半導体レーザ1から出射されるレ
ーザ光の波長をλ=780〜830nmとし,半導体レ
ーザ11から出射されるレーザ光の波長をλ=635〜
685nmに設定する。
Therefore, the wavelength of the laser light emitted from the semiconductor laser 1 is set to λ = 780-830 nm, and the wavelength of the laser light emitted from the semiconductor laser 11 is set to λ = 635-635.
Set to 685 nm.

【0058】これにより,CDファミリー(CD,CD
−R,CD−RW等)とDVDファミリー(DVD,D
VD−R,DVD−RW等)との再生を共に行うことが
可能になる。
Thus, the CD family (CD, CD
-R, CD-RW, etc.) and DVD family (DVD, D
VD-R, DVD-RW, etc.).

【0059】[0059]

【発明の効果】請求項1にかかる発明によれば,対物レ
ンズと受光手段との光路中に,第1レーザ源から入射し
たレーザ光のみを略100%反射し,その他のレーザ光
は略100%透過させる第1偏光手段と第2レーザ源か
ら入射したレーザ光のみを略100%反射し,その他の
レーザ光は略100%透過させる第2偏光手段とを配設
したので,第1及び第2レーザ源から出射されるレーザ
光の光量を有効に利用することが可能になり,高価な高
出力のレーザ源を用いなくても,基板厚の異なるディス
クに対して高精度に記録再生が可能になる。
According to the first aspect of the invention, approximately 100% of only the laser light incident from the first laser source is reflected on the optical path between the objective lens and the light receiving means, and the other laser light is approximately 100%. %, And a second polarizing means that reflects approximately 100% of only the laser light incident from the second laser source and transmits approximately 100% of the other laser light. (2) The amount of laser light emitted from the laser source can be used effectively, enabling high-precision recording and reproduction on disks with different substrate thicknesses without using expensive high-power laser sources. become.

【0060】請求項2にかかる発明によれば,対物レン
ズと受光手段との間に,第1情報記録媒体からの反射光
のみを略100%反射して第1及び第2情報記録媒体か
らの反射光の光路を分離する第3偏光手段を配設し,か
つ,受光手段を第3偏光手段で反射された第1情報記録
媒体からの反射光を受光する第1受光素子と,第3偏光
手段を透過した第2情報記録媒体からの反射光を受光す
る第2受光素子とから構成したので,第1及び第2レー
ザ源から出射されるレーザ光の光量を有効に利用するこ
とが可能になり,高価な高出力のレーザ源を用いなくて
も,基板厚の異なるディスクに対して高精度に記録再生
が可能になる。
According to the second aspect of the present invention, only approximately 100% of the reflected light from the first information recording medium is reflected between the objective lens and the light receiving means to reflect the reflected light from the first and second information recording media. A third polarizing means for separating an optical path of the reflected light, and a light receiving means for receiving the reflected light from the first information recording medium reflected by the third polarizing means; And the second light receiving element for receiving the reflected light from the second information recording medium that has passed through the means, so that the light amount of the laser light emitted from the first and second laser sources can be effectively used. Thus, recording and reproduction can be performed with high accuracy on disks having different substrate thicknesses without using an expensive high-power laser source.

【0061】請求項3にかかる発明によれば,第1レー
ザ源からのレーザ光を絞る第1アパーチャ手段と,第2
レーザ源からのレーザ光を絞る第2アパーチャ手段とを
設けたので,対物レンズの開口数を第1及び第2情報記
録媒体に適した開口数にすることが可能になる。また,
これにより,1つの対物レンズであっても球面収差の発
生が抑えられて,厚みの異なる2種類の情報記録媒体に
対して品質の高い再生信号等が得ることが可能になる。
According to the third aspect of the present invention, the first aperture means for narrowing the laser beam from the first laser source, and the second aperture means
Since the second aperture means for narrowing the laser beam from the laser source is provided, the numerical aperture of the objective lens can be set to a numerical aperture suitable for the first and second information recording media. Also,
As a result, even with a single objective lens, the occurrence of spherical aberration is suppressed, and a high-quality reproduction signal or the like can be obtained for two types of information recording media having different thicknesses.

【0062】請求項4にかかる発明によれば,透明部材
を挟んで第1及び第2偏光手段又は第1乃至第3偏光手
段を一体に積層して,これを所定の大きさにカットする
ことにより平行四辺形状のプリズムを形成して用いるよ
うにしたので,部品点数等を削減すると共に,当該プリ
ズムの量産性を向上させることが可能になる。
According to the fourth aspect of the present invention, the first and second polarizing means or the first to third polarizing means are integrally laminated with the transparent member interposed therebetween, and this is cut into a predetermined size. Therefore, since a parallelogram-shaped prism is formed and used, it is possible to reduce the number of components and the like and to improve the mass productivity of the prism.

【0063】請求項5にかかる発明によれば,プリズム
における,第1及び第2偏光手段又は第1乃至第3偏光
手段の配設面と平行な面にグレーティング等のサーボ信
号発生手段を形成したので,容易にサーボ信号が得られ
ると同時に量産性の向上が可能となると共に,部品点数
等の削減が可能になる。
According to the fifth aspect of the present invention, the servo signal generating means such as a grating is formed on a surface of the prism parallel to the surface on which the first and second polarizing means or the first to third polarizing means are provided. Therefore, a servo signal can be easily obtained, mass productivity can be improved, and the number of parts can be reduced.

【0064】請求項6にかかる発明によれば,第1レー
ザ源が出射するレーザ光の波長λ1を780〜830n
mの範囲に設定し,かつ,第2レーザ源が出射するレー
ザ光の波長λ2を635〜685nmの範囲に設定した
ので,第1又は第2情報記録媒体が,CDファミリー
(CD,CD−R,CD−RW等)又はDVDファミリ
ー(DVD,DVD−R,DVD−RW等)のいずれで
あっても,適切な波長で情報の記録再生が可能になる。
According to the invention of claim 6, the wavelength λ1 of the laser light emitted from the first laser source is set to 780 to 830n.
m, and the wavelength λ2 of the laser light emitted from the second laser source is set in the range of 635 to 685 nm, so that the first or second information recording medium is a CD family (CD, CD-R). , CD-RW, etc.) or the DVD family (DVD, DVD-R, DVD-RW, etc.), information can be recorded and reproduced at an appropriate wavelength.

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

【図1】本発明の第1の実施の形態にかかる光ディスク
装置における光学系の構成図である。
FIG. 1 is a configuration diagram of an optical system in an optical disc device according to a first embodiment of the present invention.

【図2】本発明の第2の実施の形態にかかる光ディスク
装置における光学系の構成図である。
FIG. 2 is a configuration diagram of an optical system in an optical disc device according to a second embodiment of the present invention.

【図3】本発明の第3の実施の形態にかかる光ディスク
装置における光学系の構成図である。
FIG. 3 is a configuration diagram of an optical system in an optical disk device according to a third embodiment of the present invention.

【図4】CD用PBSにおける分光特性を示した図であ
る。
FIG. 4 is a diagram illustrating spectral characteristics of a CD PBS.

【図5】広帯域PBSにおける分光特性を示した図であ
る。
FIG. 5 is a diagram illustrating spectral characteristics of a broadband PBS.

【図6】DVD用PBSの分光特性を示した図である。FIG. 6 is a diagram showing spectral characteristics of a PBS for DVD.

【図7】本発明の第4の実施の形態にかかる光ディスク
装置における光学系の構成図である。
FIG. 7 is a configuration diagram of an optical system in an optical disk device according to a fourth embodiment of the present invention.

【図8】プリズムの製造方法を説明する図である。FIG. 8 is a diagram illustrating a method of manufacturing a prism.

【図9】従来の光ディスク装置における光学系の構成図
である。
FIG. 9 is a configuration diagram of an optical system in a conventional optical disk device.

【符号の説明】[Explanation of symbols]

1,11 半導体レーザ 2,12 コリメートレンズ 3 CD用偏光ビームスプリッタ 5 対物レンズ 7 広帯域偏光ビームスプリッタ 10 受光素子 15 CD用受光素子 14 DVD用偏光ビームスプリッタ 16 DVD用受光素子 17,18 アパーチャ 19 プリズム 20 CD用偏光ビームスプリッタ膜 21 広帯域用偏光ビームスプリッタ膜 22 グレーティング DESCRIPTION OF SYMBOLS 1, 11 Semiconductor laser 2, 12 Collimating lens 3 CD polarizing beam splitter 5 Objective lens 7 Broadband polarizing beam splitter 10 Light receiving element 15 CD light receiving element 14 DVD polarizing beam splitter 16 DVD light receiving element 17, 18 Aperture 19 Prism 20 Polarizing beam splitter film for CD 21 Broadband polarizing beam splitter film 22 Grating

Claims (6)

    【特許請求の範囲】[Claims]
  1. 【請求項1】 基板厚の厚い第1情報記録媒体と当該第
    1情報記録媒体より基板厚が薄い第2記録媒体とにそれ
    ぞれ適応した波長のレーザ光を出射する第1及び第2レ
    ーザ源からなるレーザ発生手段と,該レーザ発生手段か
    らのレーザ光を集光して前記第1又は第2情報記録媒体
    に照射する対物レンズと,前記第1又は第2情報記録媒
    体からの反射光を受光して再生信号を出力する受光手段
    とを有した光ディスク装置において,前記第1レーザ源
    は,波長がλ1でS偏光のレーザ光を出射し,前記第2
    レーザ源は,波長がλ2でS偏光のレーザ光を出射し,
    かつ,λ1>λ2になるように設定され,前記対物レン
    ズと前記受光手段との光路中に,前記第1レーザ源から
    入射したレーザ光のみを反射する第1偏光手段と前記第
    2レーザ源から入射したレーザ光のみを反射する第2偏
    光手段とを配設したことを特徴とする光ディスク装置。
    1. A first and a second laser source for emitting laser beams having wavelengths respectively adapted to a first information recording medium having a large substrate thickness and a second recording medium having a substrate thickness smaller than the first information recording medium. Laser generating means, an objective lens for condensing laser light from the laser generating means and irradiating the first or second information recording medium, and receiving reflected light from the first or second information recording medium And an optical disc device having a light receiving means for outputting a read signal, wherein the first laser source emits S-polarized laser light having a wavelength of λ1,
    The laser source emits S-polarized laser light having a wavelength of λ2,
    In addition, it is set so that λ1> λ2, and the first polarization unit and the second laser source that reflect only the laser light incident from the first laser source in the optical path between the objective lens and the light receiving unit An optical disc device comprising a second polarizing means for reflecting only an incident laser beam.
  2. 【請求項2】 前記対物レンズと前記受光手段との間
    に,前記第1情報記録媒体からの反射光のレーザ光のみ
    を反射して前記第1及び第2情報記録媒体からの反射光
    の光路を分離する第3偏光手段が配設され,かつ,前記
    受光手段が,前記第3偏光手段で反射された第1情報記
    録媒体からの反射光を受光する第1受光素子と,前記第
    3偏光手段を透過した前記第2情報記録媒体からの反射
    光を受光する第2受光素子とからなることを特徴とする
    請求項1記載の光ディスク装置。
    2. An optical path of reflected light from the first and second information recording media by reflecting only the laser light of the reflected light from the first information recording medium between the objective lens and the light receiving means. A first light receiving element for receiving reflected light from the first information recording medium reflected by the third polarizing means; and a third polarizing means for receiving the third polarized light. 2. The optical disk device according to claim 1, further comprising a second light receiving element that receives reflected light from the second information recording medium that has passed through the means.
  3. 【請求項3】 前記第1レーザ源からのレーザ光を絞る
    第1アパーチャ手段と,前記第2レーザ源からのレーザ
    光を絞る第2アパーチャ手段とが設けられて,前記対物
    レンズの開口数を前記第1及び第2情報記録媒体に適し
    た開口数にしてなることを特徴とする請求項1又は2記
    載の光ディスク装置。
    A first aperture means for narrowing a laser beam from the first laser source; and a second aperture means for narrowing a laser beam from the second laser source. 3. The optical disk device according to claim 1, wherein the numerical aperture is set to a numerical aperture suitable for the first and second information recording media.
  4. 【請求項4】 前記第1及び第2偏光手段又は前記第1
    乃至第3偏光手段が,透明部材を挟んで一体に積層され
    て形成された平行四辺形状のプリズムであることを特徴
    とする請求項1乃至3記載の光ディスク装置。
    4. The first and second polarizing means or the first polarizing means.
    4. The optical disk device according to claim 1, wherein the third to third polarizing means are parallelogram prisms integrally formed with a transparent member interposed therebetween.
  5. 【請求項5】 前記プリズムにおける,前記第1及び第
    2偏光手段又は前記第1乃至第3偏光手段の配設面と平
    行な面にサーボ信号発生手段が形成されてなることを特
    徴とする請求項4記載の光ディスク装置。
    5. A servo signal generating means is formed on a surface of said prism parallel to a plane on which said first and second polarizing means or said first to third polarizing means are arranged. Item 5. The optical disk device according to item 4.
  6. 【請求項6】 前記第1レーザ源が出射するレーザ光の
    波長λ1を780〜830nmの範囲に設定し,かつ,
    前記第2レーザ源が出射するレーザ光の波長λ2を63
    5〜685nmの範囲に設定したことを特徴とする請求
    項1乃至5記載の光ディスク装置。
    6. A wavelength λ1 of the laser light emitted from the first laser source is set in a range of 780 to 830 nm, and
    The wavelength λ2 of the laser light emitted from the second laser source is 63
    6. The optical disk device according to claim 1, wherein the optical disk device is set in a range of 5 to 685 nm.
JP9076741A 1997-03-13 1997-03-13 Optical disk device Pending JPH10255317A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9076741A JPH10255317A (en) 1997-03-13 1997-03-13 Optical disk device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9076741A JPH10255317A (en) 1997-03-13 1997-03-13 Optical disk device

Publications (1)

Publication Number Publication Date
JPH10255317A true JPH10255317A (en) 1998-09-25

Family

ID=13614039

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9076741A Pending JPH10255317A (en) 1997-03-13 1997-03-13 Optical disk device

Country Status (1)

Country Link
JP (1) JPH10255317A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6980505B2 (en) 2001-09-19 2005-12-27 Nec Corporation Optical head apparatus including two light sources and one photodetector
JP2006331594A (en) * 2005-05-30 2006-12-07 Sanyo Electric Co Ltd Optical pickup device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6980505B2 (en) 2001-09-19 2005-12-27 Nec Corporation Optical head apparatus including two light sources and one photodetector
JP2006331594A (en) * 2005-05-30 2006-12-07 Sanyo Electric Co Ltd Optical pickup device
US8165003B2 (en) 2005-05-30 2012-04-24 Sanyo Electric Co., Ltd. Optical pickup device

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