JP4524736B2 - Optical element and optical pickup device - Google Patents
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本発明は、光学素子及び光ピックアップ装置に関し、特に光学性能を向上させた光学素子及び光ピックアップ装置に関する。 The present invention relates to an optical element and an optical pickup device, and more particularly to an optical element and an optical pickup device with improved optical performance.
近年、短波長赤色半導体レーザの実用化に伴い、従来の光ディスク（光情報記録媒体ともいう）である、ＣＤ（コンパクトディスク）と同程度の大きさで大容量化させた高密度の光ディスクであるＤＶＤ（デジタルバーサタイルディスク）が開発・製品化されている。しかるに、ＣＤもしくはＤＶＤを専用として情報を記録／再生できるというだけでは、光ピックアップ装置の製品としての価値は十分なものとはいえないことから、より付加価値を高めるため、ＣＤ・ＤＶＤのいずれに対しても情報の記録／再生を行うことができる、いわゆる互換型光ピックアップ装置も開発されている。 In recent years, with the practical application of short-wavelength red semiconductor lasers, high-density optical disks with the same size and large capacity as conventional optical disks (also called optical information recording media), CDs (compact disks). DVD (Digital Versatile Disc) has been developed and commercialized. However, just because information can be recorded / reproduced exclusively for a CD or DVD, the value as a product of an optical pickup device cannot be said to be sufficient. On the other hand, so-called compatible optical pickup devices capable of recording / reproducing information have also been developed.
ところで、ＣＤの仕様（光源波長、開口数、透明基板厚さ等）とＤＶＤの仕様とは異なるため、単一の対物レンズを用いて、双方の光ディスクに対して適切に情報を記録及び／又は再生するためには、何らかの工夫が必要となる。これに対し、対物レンズの光学面に回折構造を設けることで、ＣＤ、ＤＶＤに適した収差特性を得ることが行われている。 By the way, since the specifications of the CD (light source wavelength, numerical aperture, transparent substrate thickness, etc.) are different from the specifications of the DVD, information is appropriately recorded and / or recorded on both optical disks using a single objective lens. In order to reproduce, some device is required. On the other hand, aberration characteristics suitable for CDs and DVDs are obtained by providing a diffractive structure on the optical surface of the objective lens.
一方、ＣＤ・ＤＶＤより一歩進んだ、より高密度な次世代の光ディスクも開発されている。このような次世代の光ディスクを媒体とした光情報記録再生装置（光ピックアップ装置ともいう）の集光光学系では、記録信号の高密度化を図るため、或いは高密度記録信号を再生するため、対物レンズを介して情報記録面上に集光するスポッ卜の径を小さくすることが要求される。そのためには、光源であるレーザの短波長化や対物レンズの高開口数（高ＮＡ）化が必要となる。短波長レーザ光源としてその実用化が期待されているのは、波長４００ｎｍ以下の青紫色半導体レーザである。 On the other hand, higher-density next-generation optical discs, which are one step ahead of CD / DVD, have also been developed. In a condensing optical system of an optical information recording / reproducing apparatus (also referred to as an optical pickup apparatus) using such a next-generation optical disk as a medium, in order to increase the recording signal density or to reproduce the high-density recording signal, It is required to reduce the diameter of the spot condensed on the information recording surface via the objective lens. For this purpose, it is necessary to shorten the wavelength of the laser as the light source and to increase the numerical aperture (high NA) of the objective lens. A blue-violet semiconductor laser having a wavelength of 400 nm or less is expected to be put to practical use as a short wavelength laser light source.
このような波長４００ｎｍ以下の青紫色半導体レーザを用いて、情報の記録／再生を行える高密度光ディスクシステムの研究・開発が急速に進んでいる。一例として、ＮＡ０．８５、光源波長４０５ｎｍの仕様で情報記録／再生を行う光ディスク（以下、本明細書ではかかる光ディスクを「高密度ＤＶＤ」と呼ぶ）では、ＤＶＤ（ＮＡ０．６、光源波長６５０ｎｍ、記憶容量４、７ＧＢ）と同じ大きさである直径１２ｃｍの光ディスクに対して、１面あたり２０〜３０ＧＢの情報の記録が可能である。かかる高密度ＤＶＤの情報記録面に対して適切な集光スポットを形成できるように、ミクロンオーダーの微細な回折構造を設けた対物レンズも開発されている（特許文献１参照）。 Research and development of a high-density optical disk system capable of recording / reproducing information using such a blue-violet semiconductor laser having a wavelength of 400 nm or less is proceeding rapidly. As an example, in an optical disc for recording / reproducing information with specifications of NA 0.85 and light source wavelength 405 nm (hereinafter referred to as “high density DVD” in this specification), DVD (NA 0.6, light source wavelength 650 nm, Information of 20 to 30 GB per side can be recorded on an optical disk having a diameter of 12 cm, which is the same size as the storage capacity 4, 7 GB). An objective lens provided with a fine diffraction structure on the order of microns has been developed so that an appropriate focused spot can be formed on the information recording surface of such a high-density DVD (see Patent Document 1).
ところで、光源から出射されるレーザ光を効率よく利用するために、光ピックアップ装置の光学部品には、透過率を高める工夫がなされている。例えば対物レンズ等の光学面には、反射防止膜が成膜され、光の干渉を利用して光学面から反射する光の量を抑制するようにしている（特許文献２参照）。
しかるに、上述したような互換型光ピックアップ装置に用いる対物レンズに反射防止膜を成膜する場合、それに入射する異なる波長の光束それぞれに対して、反射防止を実現しなくてはならない。ところが、反射防止を実現できる波長域を広くとるためには、一般的には反射防止膜の膜厚の増大を容認せざるをえないが、膜厚の増大により、微細形状を有する回折構造の形状が設計形状に対して変形してしまい、それにより所望の回折特性が得られなくなる恐れがある。 However, when an antireflection film is formed on the objective lens used in the compatible optical pickup apparatus as described above, it is necessary to realize antireflection for each of the light beams having different wavelengths incident thereon. However, in order to widen the wavelength range in which antireflection can be realized, it is generally necessary to allow an increase in the film thickness of the antireflection film. The shape may be deformed with respect to the design shape, which may result in failure to obtain desired diffraction characteristics.
特に、輪帯形状の回折構造の場合、その断面において輪帯の頂点は不連続部となるが、このような形状であると、頂点の周囲に被膜素材が多く付着する傾向があり、それにより頂点から庇のように張り出し且つ垂れ下がる反射防止膜が形成される恐れがある。このような庇形状の反射防止膜は、入射光束を遮り、結果として透過効率を減少させるという問題がある。 In particular, in the case of an annular diffractive structure, the apex of the annular zone in the cross section becomes a discontinuous part, but with such a shape, there is a tendency that a lot of coating material adheres around the apex, thereby There is a risk of forming an antireflection film that protrudes like a ridge from the apex and hangs down. Such a saddle-shaped antireflection film has a problem in that it blocks an incident light beam and consequently reduces transmission efficiency.
本発明は、かかる従来技術の問題に鑑みてなされたものであり、被覆層の膜厚を増大させても、透過効率を高く維持できる光学素子、及びそれを用いた光ピックアップ装置を提供することを目的とする。 The present invention has been made in view of such problems of the prior art, and provides an optical element that can maintain high transmission efficiency even when the film thickness of the coating layer is increased, and an optical pickup device using the optical element. With the goal.
請求項１に記載の光学素子は、光源からの光束を光情報記録媒体に集光させる光ピックアップ装置に用いられる光学素子において、前記光学素子は、回折構造を有し、前記回折構造は、光軸方向深さが１０μｍ以下の段部を有する光軸を中心とした同心円状の輪帯を複数有し、それぞれの前記段部は、前記光学素子の光軸を含む断面において、入射光束の進行方向に連れて光軸に近づいていくようなテーパ形状面を有しており、前記テーパ形状面を含む前記段部の上に前記段部の頂点を覆うようにして被膜層が形成されており、前記被覆層は、複数の前記段部の形状に沿った凹凸を有する形状となっており、前記光学素子の光軸を含む断面において、空気側から前記段部の上に形成された前記被膜層に入射するように、光軸と平行の仮想直線をひいたときに、再度空気側を通過することなく前記光学素子に至ることを特徴とする。 The optical element according to claim 1 is an optical element used in an optical pickup device that focuses a light beam from a light source onto an optical information recording medium, wherein the optical element has a diffractive structure, and the diffractive structure is a light beam. There are a plurality of concentric ring zones centered on the optical axis having a step portion with an axial depth of 10 μm or less, and each step portion travels an incident light beam in a cross section including the optical axis of the optical element. It has a tapered surface that approaches the optical axis in the direction, and a coating layer is formed on the step portion including the tapered surface so as to cover the top of the step portion. The coating layer has a shape having irregularities along the shape of the plurality of stepped portions, and the coating formed on the stepped portion from the air side in the cross section including the optical axis of the optical element. A virtual straight line parallel to the optical axis to be incident on the layer When drawn, characterized in that lead to the optical element without passing through the re-air side.
請求項２に記載の光学素子は、請求項１に記載の発明において、前記輪帯は、鋸歯状の構造であることを特徴とする。
請求項３に記載の光学素子は、請求項１又は２に記載の発明において、前記輪帯の頂点が円弧形状（例えば図１において、点線で示すように斜面Ｓとテーパ形状Ｃ’とを滑らかにつなぐ円弧形状）となっていることを特徴とする。
According to a second aspect of the present invention, there is provided the optical element according to the first aspect , wherein the annular zone has a sawtooth structure.
According to a third aspect of the present invention, there is provided an optical element according to the first or second aspect of the present invention, wherein the top of the annular zone has a circular arc shape (for example, a slanted surface S and a tapered shape C ′ as shown by a dotted line in FIG. It is characterized by a circular arc shape that connects to
本発明を図面を参照して説明する。図１は、従来技術により被覆層を形成された光学素子の断面拡大図であり、図２は、本発明により被覆層を形成された光学素子の断面拡大図である。図１において、光学素子ＯＥは、光学面に鋸歯状の回折輪帯ＤＲを有しており、回折輪帯ＤＲは、光軸に同軸な複数の円筒面Ｃと、隣接する円筒面Ｃを連結する斜面Ｓとを有している。又、光学素子ＯＥの光学面には、被覆層としての反射防止膜ＲＭが形成されている。 The present invention will be described with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of an optical element formed with a coating layer according to the prior art, and FIG. 2 is an enlarged cross-sectional view of the optical element formed with a coating layer according to the present invention. In FIG. 1, the optical element OE has a sawtooth-shaped diffraction ring zone DR on the optical surface, and the diffraction ring zone DR connects a plurality of cylindrical surfaces C coaxial with the optical axis and adjacent cylindrical surfaces C. And a slope S. In addition, an antireflection film RM as a coating layer is formed on the optical surface of the optical element OE.
ここで、反射防止膜ＲＭは、反射防止素材を蒸着により飛散させることで、光学素子ＯＥの光学面に付着させて形成されることが多いので、回折輪帯ＤＲの円筒面Ｃと斜面Ｓとの突出した交点（先端）において、反射防止素材が堆積しやすくなっており、図１に示すような、回折輪帯ＤＲの先端から庇が垂れ下がった（オーバーハングした）ような被覆がなされることとなる。従って、光学素子ＯＥに光軸に平行な光束Ｌが入射した場合、垂れ下がった被覆の部位を通過することで、透過光率が減少する恐れがある。特に、図１に示す例では、矢印で示す光束Ｌが、反射防止膜ＲＭに入射後に一旦空気内に戻り、再度反射防止膜ＲＭに入射しそこを通過して光学素子ＯＥに至るという光路をとるが、このとき光束Ｌがどのように屈折するかは、垂れ下がった被覆の部位の形状によって変わるため、殆ど集光に寄与しえなくなり、これも透過光率を減少させることとなる。 Here, since the antireflection film RM is often formed by scattering an antireflection material by vapor deposition to adhere to the optical surface of the optical element OE, the cylindrical surface C and the inclined surface S of the diffraction ring zone DR are formed. The anti-reflection material is easy to deposit at the intersection (tip) of the projection, and as shown in FIG. 1, a coating is formed such that the heel hangs down (overhangs) from the tip of the diffraction ring zone DR. It becomes. Therefore, when the light beam L parallel to the optical axis is incident on the optical element OE, there is a possibility that the transmitted light rate may be reduced by passing through the portion of the coating that hangs down. In particular, in the example shown in FIG. 1, the light beam L indicated by the arrow returns to the air once after entering the antireflection film RM, enters the antireflection film RM again, passes therethrough, and reaches the optical element OE. However, since how the light beam L is refracted at this time varies depending on the shape of the portion of the covering that hangs down, it hardly contributes to light collection, and this also reduces the transmitted light rate.
これに対し、図２に示す本発明による構成では、反射防止膜ＲＭは、回折輪帯ＤＲ’の先端から庇が垂れ下がったような部位を有していない。これを言い換えると、回折輪帯のある突出した段部Ｔ（図２で深さがΔ）に形成された反射防止膜ＲＭ（被覆層）の部位が、段部Ｔに隣接する回折輪帯ＤＲ’を通過した光束Ｌを遮らない形状に形成されているのである。このような反射防止膜ＲＭは、例えば回折輪帯ＤＲ’の形状を変え、円筒面をテーパ形状Ｃ’とすることで実現できる。円筒面をテーパ形状Ｃ’とすれば、蒸着時に、回折輪帯ＤＲ’の先端に反射防止素材が多く堆積しても、そこから庇が垂れ下がった（オーバーハングした）ような被覆が形成されにくいからである。尚、このような被覆形状は、輪帯形状を、図１の断面で円筒面Ｃと斜面Ｓとを所定の円弧で滑らかに連結した形状とすることでも実現できるし、蒸着方法を変えることによっても実現できる。 On the other hand, in the configuration according to the present invention shown in FIG. 2, the antireflection film RM does not have a portion where the eyelids hang down from the tip of the diffraction ring zone DR ′. In other words, the portion of the antireflection film RM (covering layer) formed on the protruding step T (having a depth Δ in FIG. 2) having a diffraction ring zone is adjacent to the step T. It is formed in a shape that does not block the light beam L that has passed through. Such an antireflection film RM can be realized, for example, by changing the shape of the diffraction ring zone DR 'and changing the cylindrical surface to a tapered shape C'. If the cylindrical surface has a tapered shape C ′, even if a large amount of antireflection material is deposited on the tip of the diffraction zone DR ′ during vapor deposition, it is difficult to form a coating in which wrinkles hang down (overhang) therefrom. Because. In addition, such a covering shape can be realized by making the annular shape into a shape in which the cylindrical surface C and the slope S are smoothly connected with a predetermined arc in the cross section of FIG. 1, or by changing the deposition method. Can also be realized.
本発明によれば、例えば、光学素子ＯＥに光軸に平行な光束Ｌが入射した場合、反射防止膜ＲＭに入射した光束Ｌ（断面上の仮想直線で表している）は、原則的に空気内に戻ることなくそこを通過して光学素子ＯＥに至るという光路をとるため、集光に寄与させる光束を増大させることができ、それにより透過光率を増大させることができる。 According to the present invention, for example, when a light beam L parallel to the optical axis is incident on the optical element OE, the light beam L (represented by a virtual straight line on the cross section) incident on the antireflection film RM is basically air. Since the optical path that passes through the optical element OE without going back into the optical element OE is taken, the luminous flux contributing to the condensing can be increased, whereby the transmitted light rate can be increased.
請求項４に記載の光学素子は、請求項１乃至３のいずれかに記載の発明において、前記円弧形状の曲率半径（図１でＲ）が、１μｍ〜４μｍであることを特徴する。
請求項５に記載の光学素子は、請求項１乃至４のいずれかに記載の発明において、前記被膜層の厚さは、０．０５μｍ〜０．６μｍであることを特徴とする。
請求項６に記載の光学素子は、請求項１乃至５のいずれかに記載の発明において、前記輪帯の前記段部の光軸方向深さは、１μｍ以上であることを特徴とする。
An optical element according to a fourth aspect is characterized in that, in the invention according to any one of the first to third aspects , a radius of curvature (R in FIG. 1) of the arc shape is 1 μm to 4 μm.
The optical element according to claim 5 is the invention according to any one of claims 1 to 4 , wherein the thickness of the coating layer is 0.05 μm to 0.6 μm.
An optical element according to a sixth aspect is characterized in that, in the invention according to any one of the first to fifth aspects, a depth in the optical axis direction of the step portion of the annular zone is 1 μm or more.
請求項７に記載の光学素子は、請求項１乃至６に記載の発明において、前記被膜層は反射防止コートであることを特徴とする。 An optical element according to a seventh aspect is characterized in that, in the invention according to the first to sixth aspects, the coating layer is an antireflection coating.
請求項８に記載の光学素子は、請求項１乃至７のいずれかに記載の発明において、前記被膜層は、その組成成分としてＳｉＯ2及び酸化タンタルを含むことを特徴とする。 An optical element according to an eighth aspect is the invention according to any one of the first to seventh aspects, wherein the coating layer contains SiO 2 and tantalum oxide as its composition components.
請求項９に記載の光学素子は、請求項１乃至８のいずれかに記載の発明において、前記被膜層において、波長４００ｎｍ〜４１０ｎｍの光束の透過率が、９０％以上であることを特徴とする。
請求項１０に記載の光学素子は、請求項１乃至９のいずれかに記載の発明において、前記光ピックアップ装置の前記光源の波長が３９０〜４５０ｎｍであることを特徴とする。
An optical element according to a ninth aspect is characterized in that, in the invention according to any one of the first to eighth aspects, in the coating layer, a transmittance of a light beam having a wavelength of 400 nm to 410 nm is 90% or more. .
An optical element according to a tenth aspect is characterized in that, in the invention according to any one of the first to ninth aspects, the wavelength of the light source of the optical pickup device is 390 to 450 nm.
請求項１１に記載の光ピックアップ装置は、光源と、前記光源からの光束を光情報記録媒体に集光させる、請求項１乃至１０のいずれかに記載の光学素子を含む集光光学系と、を有することを特徴とする。
An optical pickup device according to an eleventh aspect includes a light source and a condensing optical system including the optical element according to any one of claims 1 to 10 , which condenses a light beam from the light source onto an optical information recording medium. It is characterized by having.
本明細書中で用いる「回折構造」とは、光学部品の表面に、レリーフを設けて、回折によって光束を集光あるいは発散させる作用を持たせた部分のことをいう。レリーフの形状としては、光学部品の表面に、光軸を中心とする略同心円状の輪帯として形成され、光軸を含む平面でその断面をみれば各輪帯は鋸歯のような形状や階段状の形状のものが知られているが、そのような形状を含むものであり、そのような形状を特に「回折輪帯」という。 The “diffractive structure” used in the present specification refers to a portion provided with a relief on the surface of an optical component so as to condense or diverge a light beam by diffraction. The shape of the relief is formed as a substantially concentric ring zone centered on the optical axis on the surface of the optical component, and each ring zone is shaped like a sawtooth or a staircase when the cross section is viewed in a plane including the optical axis. Although the shape of a shape is known, such a shape is included and such a shape is especially called a "diffraction ring zone."
本明細書中において、対物レンズとは、狭義には光ピックアップ装置に光情報記録媒体を装填した状態において、最も光情報記録媒体側の位置で、これと対向すべく配置される集光作用を有するレンズを指し、広義にはそのレンズと共に、アクチュエータによって少なくともその光軸方向に作動可能なレンズを指すものとする。 In this specification, the objective lens is, in a narrow sense, a light collecting action that is arranged to face the optical information recording medium at the position closest to the optical information recording medium when the optical information recording medium is loaded in the optical pickup device. In a broad sense, it refers to a lens that can be operated at least in the optical axis direction by an actuator.
本発明によれば、被覆層の膜厚を増大させても、透過効率を高く維持できる光学素子、及びそれを用いた光ピックアップ装置を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, even if it increases the film thickness of a coating layer, the optical element which can maintain high transmission efficiency, and an optical pick-up apparatus using the same can be provided.
以下、本発明の実施の形態を図面を用いて説明する。図３は、本実施の形態にかかる光ピックアップ装置の概略構成図である。図３において、光源としての半導体レーザ１からの光束（波長３９０〜４５０ｎｍ）は、ビームスプリッタ２を通過し、光源側の面（第１の光学面）に回折構造を形成した対物レンズ４に入射し、対物レンズ４の回折構造を形成していない媒体側面（第２の光学面）から出射した光束は、高密度ＤＶＤである光情報記録媒体５の情報記録面に集光される。一方、光情報記録媒体５から反射した光は、対物レンズ４を通過し、ビームスプリッタ２により半導体レーザ１と異なる方向に反射され、非点収差発生レンズ６で非点収差を発生された後、光検出器７で受光されるようになっている。尚、図示していないが、対物レンズを一体で光軸方向に移動させるフォーカシング機構が設けられている。
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 3 is a schematic configuration diagram of the optical pickup device according to the present embodiment. In FIG. 3, a light beam (wavelength 390 to 450 nm) from a semiconductor laser 1 as a light source passes through a beam splitter 2 and is incident on an objective lens 4 having a diffractive structure formed on a light source side surface (first optical surface). The light beam emitted from the side surface (second optical surface) of the objective lens 4 on which the diffractive structure is not formed is condensed on the information recording surface of the optical information recording medium 5 that is a high-density DVD. On the other hand, the light reflected from the optical information recording medium 5 passes through the objective lens 4, is reflected in a direction different from that of the semiconductor laser 1 by the beam splitter 2, and astigmatism is generated by the
（実施例）
図３の光ピックアップ装置に用いるのに好適な光学素子としての対物レンズの実施例を説明する。
(Example)
An embodiment of an objective lens as an optical element suitable for use in the optical pickup device of FIG. 3 will be described.
反射防止膜の材料としては、以下のものを用いた。
（１）低屈折率材料（Ｌ材）：フッ化アルミニウム、フッ化マグネシウム、酸化シリコン：屈折率１．３０〜１．５０
（２）中屈折率材料（Ｍ材）：酸化アルミニウム、酸化イットリウム、フッ化セリウム：屈折率１．５５〜１．７０
（３）高屈折率材料（Ｈ材）：酸化ジルコニウム、酸化タンタル、酸化チタン、酸化ハウニウム：屈折率１．７５〜２．５０
以上の材料を単独で、もしくはそれを主成分とした混合材料として、対物レンズの光学面にコートした。光学部品である対物レンズを構成する材料は、アクリル樹脂、ポリカーボネート樹脂、より具体的な例として、ゼオネックス（日本ゼオン（株）製の商品名）等の透明なプラスチック樹脂又はガラス材であるが、プラスチック樹脂は、上記樹脂に限定されるものではなく、光学部品の素材に適する全ての樹脂を含む。
The following materials were used as the material for the antireflection film.
(1) Low refractive index material (L material): Aluminum fluoride, magnesium fluoride, silicon oxide: Refractive index 1.30 to 1.50
(2) Medium refractive index material (M material): aluminum oxide, yttrium oxide, cerium fluoride: refractive index 1.55 to 1.70
(3) High refractive index material (H material): zirconium oxide, tantalum oxide, titanium oxide, haonium oxide: refractive index of 1.75 to 2.50
The above materials were coated on the optical surface of the objective lens alone or as a mixed material containing the above as a main component. The material constituting the objective lens, which is an optical component, is an acrylic resin, a polycarbonate resin, and, as a more specific example, a transparent plastic resin or glass material such as ZEONEX (trade name of Nippon Zeon Co., Ltd.), The plastic resin is not limited to the above resin, and includes all resins suitable for the material of the optical component.
コート方法は、真空蒸着方法、スパッタ方法、ＣＶＤ方法、大気圧プラズマ法、塗布法、ミスト法などがあるが、本実施例では、真空蒸着方法を採用した。 Examples of the coating method include a vacuum deposition method, a sputtering method, a CVD method, an atmospheric pressure plasma method, a coating method, and a mist method. In this example, a vacuum deposition method was employed.
本実施例では、同じ条件での比較例（従来構造）に対し、透過効率を２％向上させることができた。 In this example, the transmission efficiency was improved by 2% compared to the comparative example (conventional structure) under the same conditions.
以上、本発明を実施の形態を参照して説明してきたが、本発明は上記実施の形態に限定して解釈されるべきではなく、適宜変更・改良が可能であることはもちろんである。 The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, and can be modified or improved as appropriate.
１ 光源
２ ビームスプリッタ
４ 対物レンズ
５ 光情報記録媒体（光ディスク）
７ 光検出器
DESCRIPTION OF SYMBOLS 1 Light source 2 Beam splitter 4 Objective lens 5 Optical information recording medium (optical disk)
7 Photodetector
Claims (11)
前記光学素子は、回折構造を有し、
前記回折構造は、光軸方向深さが１０μｍ以下の段部を有する光軸を中心とした同心円状の輪帯を複数有し、
それぞれの前記段部は、前記光学素子の光軸を含む断面において、入射光束の進行方向に連れて光軸に近づいていくようなテーパ形状面を有しており、
前記テーパ形状面を含む前記段部の上に前記段部の頂点を覆うようにして被膜層が形成されており、
前記被覆層は、複数の前記段部の形状に沿った凹凸を有する形状となっており、
前記光学素子の光軸を含む断面において、空気側から前記段部の上に形成された前記被膜層に入射するように、光軸と平行の仮想直線をひいたときに、再度空気側を通過することなく前記光学素子に至ることを特徴とする光学素子。 In an optical element used in an optical pickup device that focuses a light beam from a light source on an optical information recording medium,
The optical element has a diffractive structure;
The diffractive structure has a plurality of concentric annular zones centering on the optical axis having a step portion having an optical axis direction depth of 10 μm or less,
Each of the step portions has a tapered surface that approaches the optical axis in the traveling direction of the incident light beam in a cross section including the optical axis of the optical element,
A coating layer is formed so as to cover the top of the stepped portion on the stepped portion including the tapered surface,
The coating layer has a shape having irregularities along the shape of the plurality of steps,
In the cross section including the optical axis of the optical element, when passing a virtual straight line parallel to the optical axis so as to be incident on the coating layer formed on the step portion from the air side, the optical element passes through the air side again. An optical element that reaches the optical element without being performed.
前記光源からの光束を光情報記録媒体に集光させる、請求項１乃至１０のいずれかに記載の光学素子を含む集光光学系と、を有することを特徴とする光ピックアップ装置。 A light source;
Condenses the light beam from the light source to the optical information recording medium, an optical pickup device characterized by having a converging optical system including an optical element according to any one of claims 1 to 10.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60103311A (en) * | 1983-11-03 | 1985-06-07 | インタ−ナショナル ビジネス マシ−ンズ コ−ポレ−ション | Manufacture of fresnel phase plate lens |
| JP2002189114A (en) * | 2000-10-02 | 2002-07-05 | Konica Corp | Optical element, metallic mold and tool |
| JP2002298422A (en) * | 2001-03-30 | 2002-10-11 | Asahi Optical Co Ltd | Objective lens for optical head |
| JP2002365533A (en) * | 2001-06-07 | 2002-12-18 | Matsushita Electric Ind Co Ltd | Objective lens, and optical head device, aberration measuring method and optical information recording/ reproducing device using the same |
| JP2003215310A (en) * | 2001-11-15 | 2003-07-30 | Konica Corp | Optical lens and optical information recording and reproducing device |
| WO2003075267A1 (en) * | 2002-03-06 | 2003-09-12 | Matsushita Electric Industrial Co., Ltd. | Optical head device and optical information device using this, and computer, optical disk player, car navigation system, optical disy recorder and optical disk server using this optical information device |
-
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60103311A (en) * | 1983-11-03 | 1985-06-07 | インタ−ナショナル ビジネス マシ−ンズ コ−ポレ−ション | Manufacture of fresnel phase plate lens |
| JP2002189114A (en) * | 2000-10-02 | 2002-07-05 | Konica Corp | Optical element, metallic mold and tool |
| JP2002298422A (en) * | 2001-03-30 | 2002-10-11 | Asahi Optical Co Ltd | Objective lens for optical head |
| JP2002365533A (en) * | 2001-06-07 | 2002-12-18 | Matsushita Electric Ind Co Ltd | Objective lens, and optical head device, aberration measuring method and optical information recording/ reproducing device using the same |
| JP2003215310A (en) * | 2001-11-15 | 2003-07-30 | Konica Corp | Optical lens and optical information recording and reproducing device |
| WO2003075267A1 (en) * | 2002-03-06 | 2003-09-12 | Matsushita Electric Industrial Co., Ltd. | Optical head device and optical information device using this, and computer, optical disk player, car navigation system, optical disy recorder and optical disk server using this optical information device |
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