JPS60176012A - Objective lens for optical pickup - Google Patents

Objective lens for optical pickup

Info

Publication number
JPS60176012A
JPS60176012A JP59032203A JP3220384A JPS60176012A JP S60176012 A JPS60176012 A JP S60176012A JP 59032203 A JP59032203 A JP 59032203A JP 3220384 A JP3220384 A JP 3220384A JP S60176012 A JPS60176012 A JP S60176012A
Authority
JP
Japan
Prior art keywords
lens
optical pickup
objective lens
convex
objective
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
JP59032203A
Other languages
Japanese (ja)
Inventor
Ichiro Morishita
一郎 森下
Masaru Arai
優 新井
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.)
Alps Alpine Co Ltd
Original Assignee
Alps Electric Co Ltd
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 Alps Electric Co Ltd filed Critical Alps Electric Co Ltd
Priority to JP59032203A priority Critical patent/JPS60176012A/en
Publication of JPS60176012A publication Critical patent/JPS60176012A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00—Optical objectives specially designed for the purposes specified below
    • G02B13/14—Optical objectives specially designed for the purposes specified below for use with infrared or ultraviolet radiation

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Lenses (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE:To mass-produce the whole lens system, and to reduce its cost by combining the first - the third lenses having a prescribed shape. CONSTITUTION:An objective lens for an optical pickup consists of planoconvex lenses 1, 2 whose one surface is a plane, and a positive meniscus lens 3 having a convex shape in the direction of a disk 4. In this state, when a focal distance of the whole system, a radius of curvature of a convex surface of the lens 2, a radius of curvature of the surface of the lens 2 side in the lens 3, and a focal distance of the lens 3 are denoted as (f), r3, r5, and f3, respectively, they are set so as to satisfy the expressions.

Description

【発明の詳細な説明】 〔技術分野〕 本発明はコンパクトディスクプレーヤなどに用いられる
光ピツクアップに係り、特に、レーザビームなどをディ
スクの記録面に集光させる対物レンズに関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical pickup used in a compact disc player, and more particularly to an objective lens for condensing a laser beam or the like onto a recording surface of a disc.

〔技術的背景ならびに従来技術〕[Technical background and conventional technology]

コンパクトディスクプレーヤなどに用いられる光ピツク
アップには１．レーザビームなどをディスクの記録面に
集光させる対物レンズが備えられている。第１図はこの
種の光ピツクアップを用いたプレーヤの概略を示すもの
である。図中の符号４はディスクであり、その中央はス
ピンドル１１１に支持されて回転駆動されるようになっ
ている。また、ディスク４の下側に光ピツクアップ１２
が配設されている。この光ピツクアップ１２はディスク
４の半径方向に沿って駆動されるものである。この光ピ
ツクアップ１２には鏡筒ｌＯが設けられ、この鏡筒１０
内に対物レンズが収納されている。そして、光ピツクア
ップ１２内にて発せられるレーザビームがこの対物レン
ズｉこよってディスク４の記録面に集光され、記録面の
ピットが読取られて記録の再生が行われるようになって
いる。Optical pickups used in compact disc players, etc. have 1. It is equipped with an objective lens that focuses a laser beam or the like onto the recording surface of the disk. FIG. 1 schematically shows a player using this type of optical pickup. Reference numeral 4 in the figure is a disk, the center of which is supported by a spindle 111 and driven to rotate. In addition, an optical pickup 12 is provided below the disk 4.
is installed. This optical pickup 12 is driven along the radial direction of the disk 4. This optical pickup 12 is provided with a lens barrel lO, and this lens barrel 10
The objective lens is housed inside. A laser beam emitted within the optical pickup 12 is focused onto the recording surface of the disk 4 by the objective lens i, and the pits on the recording surface are read to reproduce the recording.

〔従来技術の問題点〕[Problems with conventional technology]

ところで、上記の光ピツクアップでは、ディスク４の記
録面に高い密度にて記録された非常に小さな信号を再生
しなければならず、少なくとも１ｇ、ｍの分解能が必要
とされる。よって、ディスク４の記録面に微小なビーム
スポットを高精度にて集光させなければならない。また
、情報の正確な再生のためには、対物レンズの球面収差
に適切な補正を与え、さらに最もディスクに近い位置の
レンズとディスクとの距離（作動圧ｔｉｌｌ：）も十分
な長さにしなければならないなど種々の条件が満足され
なければならない。By the way, in the above optical pickup, it is necessary to reproduce very small signals recorded at high density on the recording surface of the disk 4, and a resolution of at least 1 gm is required. Therefore, it is necessary to focus a minute beam spot on the recording surface of the disk 4 with high precision. In addition, in order to reproduce information accurately, the spherical aberration of the objective lens must be appropriately corrected, and the distance between the lens closest to the disk and the disk (operating pressure till:) must be sufficiently long. Various conditions must be met, such as:

ところが、このような条件を満たす対物レンズを構成す
るためには、高精度なレンズ系が必要とされる。従来、
このような高精度なレンズ系を構成するには、量産性が
劣り且つコスト高なレンズを使用せざるを得ない問題点
がある。However, in order to construct an objective lens that satisfies such conditions, a highly accurate lens system is required. Conventionally,
In order to construct such a highly accurate lens system, there is a problem in that it is necessary to use lenses that are difficult to mass produce and are expensive.

〔本発明の目的〕[Object of the present invention]

本発明は上記従来の問題点に着目してなされたものであ
り、製造しやすい形状のレンズを使用して量産性への適
用とコストダウンを図り、しかも、高分解能が可能とな
り、球面収差の補正も最適になるなど各種条件を満足で
きる光ピツクアップ用対物レンズを提供することを目的
としている。The present invention has been made by focusing on the above-mentioned conventional problems, and aims to apply it to mass production and reduce costs by using a lens with an easy-to-manufacture shape.It also enables high resolution and eliminates spherical aberration. The objective is to provide an objective lens for optical pickup that satisfies various conditions such as optimum correction.

〔本発明の構成〕[Configuration of the present invention]

本発明による光ピ・ンクアップ用対物レンズは、第２図
に示すように、同軸上に配設された第ルンズ（１）、第
２レンズ（２）および第３レンズ（３）とか、ら成り、
第ルンズ（１）と第２レンズ（２）が共に片面が平面の
平凸レンズであり、且つディスク（４）側に対向する第
３レンズ（３）がディスク（４）方向へ凸形状となる正
のメニスカスレンズであることを特徴としている。この
ように、製造が比較的容易な平凸レンズ（１）および（
２）を使用することによって、レンズ系全体の量産化を
図り、コストダウンを実現できるようにしたものである
。The optical pin-up objective lens according to the present invention, as shown in FIG. ,
Both the second lens (1) and the second lens (2) are plano-convex lenses with one side having a flat surface, and the third lens (3) facing the disk (4) side is a positive lens that is convex toward the disk (4). It is characterized by being a meniscus lens. In this way, the plano-convex lens (1) and (
By using 2), the entire lens system can be mass-produced and costs can be reduced.

また、第２レンズ（２）と第３レンズ（３）は以下の条
件に適合するように製作されている。Further, the second lens (2) and the third lens (3) are manufactured to meet the following conditions.

■１．ｏｆ＜　ｒ３　＜　１．２ｆ ■−１，７ｆ　＜　ｒ５　＜−１，４ｆ■　ｆ３＜１０
．Ｏｆ ただし、ｆは全系の焦点距離、ｒ３は第２レンズの凸面
の曲率半径、ｒ５は第３レンズにおける第２レンズ側の
而の曲率半径、ｆ３は第３レンズの焦点距離である。■1. of< r3 < 1.2f ■-1,7f < r5 <-1,4f ■ f3<10
．． Of, where f is the focal length of the entire system, r3 is the radius of curvature of the convex surface of the second lens, r5 is the radius of curvature of the third lens on the second lens side, and f3 is the focal length of the third lens.

上記の条件のうち、■と■は光ピツクアップ用対物レン
ズとして使用するための補正要件が非常に厳しい球面収
差に関する条件である。この条件■と■においてｒ３　
、ｒ５が上限を越えると球面収差が大きくなり光ピツク
アップ用対物レンズとしての性能を満たさなくなる。ま
た、ｒ３＋ｒ５が下限を越えると球面収差が補正過剰と
なる。Among the above conditions, (1) and (2) are conditions related to spherical aberration, which require very strict correction requirements for use as an objective lens for optical pickup. Under these conditions ■ and ■, r3
, r5 exceeds the upper limit, the spherical aberration becomes large and the performance as an objective lens for optical pickup is no longer satisfied. Furthermore, if r3+r5 exceeds the lower limit, spherical aberration will be overcorrected.

さらに、前記条件のうち■はレンズ系の作動距離を十分
大きく保つためのものである。この条件■において、ｆ
３が１０．Ｏｆよりも大きくなると作動距離が小さくな
って光ピツクアップ用対物レンズとしては使用上不便に
なる。Furthermore, among the above conditions, (2) is for keeping the working distance of the lens system sufficiently large. In this condition ■, f
3 is 10. If it is larger than Of, the working distance becomes small, making it inconvenient to use as an objective lens for optical pickup.

〔本発明の実施例〕[Example of the present invention]

次に、上記にて説明した光ピツクアップ用対物レンズの
実施例を示す（各符号については第２図谷照）。Next, an example of the optical pickup objective lens described above will be shown (each reference numeral is shown in Fig. 2).

（実施例１） ｒ　ｌ＝　２．９３５９ ｄ　ｒ　＝　０．３８６３　ｎ　１＝　１．７８８７！
３ｒ２＝ｏｏ（平面） ｄ　２　＝　０．０５１５ ｒ　３　＝　１．０８１６ ｄ３　＝、０．３８８３　ｎ３　＝１．７６８７９ｒ４
−■（平面） ｄ　４＝　０．０８９５ ｒ　＝、　＝　−１，４０８１ ｄｓ　＝０．４２．４９　ｎｓ　＝１．５１１４３ｒ　
６　＝　−１，１，５８９ ｆ＝ｌ　ＮＡ＝０．４８　ＷＤ＝０．３３１１１ｔ　＝
０．３０９０　ｆ３　＝８．１４８８（実施例２） ｒ　１　＝　２．１３７１５ ｄ　１　＝　０．３４０２　ｎ　Ｉ＝　１．７８１３７
９ｒ２＝ａｏ（平面） ｄ２＝０．０３８８ ｒ　３　＝　１．０１１８２ ｄｓ　＝０．３８７８　ｎ３−１．７６８７１１１ｒ４
＝ｏｏ（平面） ｄ４＝０．（１７１１ ｒ５　＝−１，４１１１ｔ８ ｄｓ　’＝０．４３０？　ｎｓ　＝１．５１１４３ｒ６
　＝−１，１８８４ ｆ＝Ｉ　ＮＡ＝０：４７４　ＷＤ＝０．３８９２ｔ　＝
０．２５８４　ｆ、　＝８．７：１９（実施例３） この実施例では、第ルンズ（１）、第２レンズ（２）お
よび第３レンズ（３）が同一材料によって構成されてい
る（ｎｔ　＝ｎ３　＝ｎｓ）ｅｒ　１　＝　２．６７１
９ ｄ　ｌ＝　０．４０７２　ｎ　ｔ　＝　１．７６８７１
１ｒ２＝■（平面） ｄ２＝０．０７５０ ｒ　３　＝　１．０５２４ ｄ３＝０．４１４５　ｎ３　＝１．７８６７８ｒ４＝（
１）〔平面〕 ｄ　４　＝　０．０５２４ ｒ　５　＝　−１，４２２３ ｄｓ”０．４１４５　”　ｎ５　＝１．７８８’）’１
ｒ　６　＝　−１，２１１１８０ ｆ＝Ｉ　ＮＡ＝０．４８０　ＷＤ＝８．３９１２ｔ　＝
０．２４８７　ｆ、　＝８．８８０１（実施例４） この実施例においても、第ルンズ（１）５第２レンズ（
２）および第３レンズ（３）は同一材料によって構成さ
れている（ｎｌ＝ｎ３＝ｎｓ　）ｅｒ　ｌ　＝　３．７
７５８ ｄ　１　＝　０．４１４１１　ｎ　１　＝　１．８９７
８８ｒ２＝ｏｏ（平面） ｄ２　＝０．０５５３ ｒ　３　＝　１．１８９４ ｄｓ　＝０．４１４９　ｎ３　＝１．８１３７６８ｒ４
＝ｏｏ（平面） ｄ４　＝０．０７４７ ｒ　５　＝　−１，８１８１ ｄｓ　＝０．４５８４　ｎ５　＝１．８１１１７６８ｒ
　６　＝　−１，５３５１ ｆ＝Ｉ　ＮＡ＝０．４Ｂ４　ＷＤ＝０．３８０３ｔ　＝
（３，３３１９ｆ３　＝９．２５８７ただし、ｒｌ＋ｒ
２・・・＋ｒ６はレンズ各面の曲率半径、ｄｌ＋ｄ２・
・・＋ｄ５は各レンズの肉厚および空気間隔、ｎｌ　、
ｎ３１　ｎ５は各レンズのλ＝　７６８．２　ｎ　ｍに
対する屈折率、またｆは全系の焦点距離、ＷＤは作動距
離、ｔは光ディスクの厚さ、ｆ３は第３レンズ（３）の
焦点距離である。(Example 1) r l = 2.9359 d r = 0.3863 n 1 = 1.7887!
3r2=oo (plane) d2 = 0.0515 r3 = 1.0816 d3 =, 0.3883 n3 = 1.76879r4
-■ (Plane) d 4 = 0.0895 r =, = -1,4081 ds = 0.42.49 ns = 1.51143r
6 = -1,1,589 f=l NA=0.48 WD=0.33111t =
0.3090 f3 = 8.1488 (Example 2) r 1 = 2.13715 d 1 = 0.3402 n I = 1.78137
9r2=ao (plane) d2=0.0388 r3=1.01182 ds=0.3878 n3-1.7687111r4
=oo (plane) d4=0. (1711 r5 = -1,4111t8 ds' = 0.430? ns = 1.51143r6
=-1,1884 f=I NA=0:474 WD=0.3892t=
0.2584 f, =8.7:19 (Example 3) In this example, the first lens (1), the second lens (2) and the third lens (3) are made of the same material (nt = n3 = ns) er 1 = 2.671
9 d l = 0.4072 n t = 1.76871
1r2=■(plane) d2=0.0750 r3=1.0524 d3=0.4145 n3=1.78678r4=(
1) [Plane] d 4 = 0.0524 r 5 = -1,4223 ds"0.4145" n5 = 1.788')'1
r 6 = -1,211180 f=I NA=0.480 WD=8.3912t =
0.2487 f, =8.8801 (Example 4) Also in this example, the 5th lens (1), 5th lens (
2) and the third lens (3) are made of the same material (nl=n3=ns)er l = 3.7
758 d 1 = 0.41411 n 1 = 1.897
88r2=oo (plane) d2 =0.0553 r3 = 1.1894 ds =0.4149 n3 =1.813768r4
=oo (plane) d4 =0.0747 r5 = -1,8181 ds =0.4584 n5 =1.8111768r
6 = -1,5351 f=I NA=0.4B4 WD=0.3803t =
(3,3319f3 =9.2587 However, rl+r
2...+r6 is the radius of curvature of each lens surface, dl+d2・
...+d5 is the wall thickness and air spacing of each lens, nl,
n31 n5 is the refractive index of each lens for λ = 768.2 nm, or f is the focal length of the entire system, WD is the working distance, t is the thickness of the optical disk, and f3 is the focal length of the third lens (3). be.

上記各実施例にて示すレンズを使用すれば、開口率ＮＡ
が０．４８〜０．４８４となり、光ピ、ツクアップ用対
物レンズに最適な値になる。また、■、■の条件により
球面収差が最適な範囲に補正され、さらに作動距離ＷＤ
も十分大きくとれる。If the lenses shown in each of the above embodiments are used, the aperture ratio NA
is 0.48 to 0.484, which is the optimum value for an objective lens for optical pickup and pickup. In addition, the spherical aberration is corrected to the optimal range by the conditions ■ and ■, and the working distance WD
can also be made large enough.

第３図は、上記各実施例のうち（実施例１）の対物レン
ズの横収差曲線を示したものである。この図から解るよ
うに、横収差は最少の範囲内に抑えられている。光ピツ
クアップ用対物レンズでは、この横収差が抑えられてい
れば、光デイスク上のビットによる情報の読取りが高精
度に行なわれることになる。FIG. 3 shows the lateral aberration curve of the objective lens of (Example 1) among the above-mentioned examples. As can be seen from this figure, lateral aberrations are kept to a minimum. In the optical pickup objective lens, if this lateral aberration is suppressed, information from the bits on the optical disk can be read with high precision.

Ｃ本発明の効果〕 以上のように本発明によれば以下に列記する効果を奏す
るようになる。C. Effects of the present invention] As described above, according to the present invention, the following effects can be achieved.

（１）第ルンズと第２レンズとが平凸レンズによって構
成されている。この平凸レンズは片面が平面であるため
、他の形状の凸レンズと比較して研磨工程が簡単になり
、且つレンズの肉厚の管理がしやすい。よって他の凸レ
ンズに比べ量産性に優れ、さらに高精度のレンズとなる
。したがって、平凸レンズ２枚とメニスカスレンズ１枚
とで構成される本発明の対物レンズは他の凸レンズを含
むものに比べ低コストで高精度のものになる。(1) The first lens and the second lens are constituted by plano-convex lenses. Since one side of this plano-convex lens is flat, the polishing process is simpler and the thickness of the lens can be easily controlled compared to convex lenses of other shapes. Therefore, compared to other convex lenses, this lens is superior in mass production and has even higher precision. Therefore, the objective lens of the present invention, which is composed of two plano-convex lenses and one meniscus lens, is lower in cost and more accurate than other lenses including convex lenses.

さらに、平凸レンズの場合には形状が簡単であるため、
将来プレス成形できるレンズ材料を使用することになっ
た場合にも適用しやすい。よって、さらにコストダウン
の余地を残していることになる。Furthermore, since the plano-convex lens has a simple shape,
It is also easy to apply when it is decided to use a lens material that can be press-molded in the future. Therefore, there is still room for further cost reduction.

（２）平凸レンズは片面が平面であるため、レンズを鏡
筒などに組付ける際に、上記の平面部分を基準とし、あ
るいは平面部分を受けることによって、位置決めが行な
いやすいメリットがある。(2) Since one side of a plano-convex lens is flat, there is an advantage that when assembling the lens into a lens barrel, positioning can be easily performed by using the flat part as a reference or by receiving the flat part.

よって、対物レンズ全体の組立作業が簡単で且つ組立精
度も高くなる。また、レンズを受ける側の鏡筒などの製
作も容易になる。Therefore, the task of assembling the entire objective lens is simple and the assembly precision is also high. Furthermore, it becomes easier to manufacture the lens barrel on the side that receives the lens.

（３）請求の範囲第（２）項に記載する条件■、■およ
び■に基づいて第２レンズと第３レンズを構成すれば、
平凸レンズとメニスカスレンズの組合せにおいても、最
適な球面収差の補正と、作動距離を得ることができるよ
うになり、光ピツクアップ用対物レンズとしての機能は
十分発揮できることになる。(3) If the second lens and the third lens are configured based on the conditions (2), (2), and (2) described in claim (2),
Even in the combination of a plano-convex lens and a meniscus lens, it is now possible to obtain optimal spherical aberration correction and working distance, and the function as an objective lens for optical pickup can be fully demonstrated.

（４）請求の範囲第（３）項に記載するように第ルンズ
、第２レンズ、第３レンズを全て同一材料によって構成
すればレンズの製作が一層容易になり、材料管理などの
面でコストダウンを促進できることになる。(4) As stated in claim (3), if the first lens, second lens, and third lens are all made of the same material, the manufacturing of the lens becomes easier and costs are reduced in terms of material management, etc. This will help promote down.

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

第１図は光ピツクアップの概要を示す説明図、第２図は
本発明による光ピツクアップ用対物レンズを、主軸を水
平に向けた状態にて示した断面図、第３図は本発明の１
つの実施例による光ピツクアップ用対物レンズの横収差
曲線である。 （＋）・・・第ルンズ、（２，）・・・第２レンス、　
（３）・・・第３レンズ、（４）・・・光ディスク、ｌ
Ｏ・・・対物レンズ、１２・・・光ピツクアップ、ｒｌ
−ｒ６・°゛レンズ曲率半径、ｄｌ　＊　ｄ３　＋　ｃ
ｉｓ・・・レンズの主軸上における厚さ、ｄ２＋ｄ４・
・・レンズ間距離、ｎｌ＋ｎ３．ｎ５・・・レンズの屈
折率。FIG. 1 is an explanatory diagram showing an overview of optical pickup, FIG. 2 is a sectional view showing an objective lens for optical pickup according to the present invention with its principal axis oriented horizontally, and FIG. 3 is an explanatory diagram showing an overview of optical pickup.
3 is a transverse aberration curve of an objective lens for optical pickup according to two embodiments. (+)...Second run, (2,)...Second run,
(3)...Third lens, (4)...Optical disc, l
O...Objective lens, 12...Optical pickup, rl
−r6・°゛Lens curvature radius, dl * d3 + c
is...Thickness on the main axis of the lens, d2+d4・
... Distance between lenses, nl+n3. n5...Refractive index of the lens.

Claims (3)

【特許請求の範囲】[Claims] （１）同軸上に配設された第ルンズ、第２レンズおよび
第３レンズとから成り、第ルンズと第２レンズは共に片
面が平面の平凸レンズであり、且つ記録媒体に対物する
第３レンズは記録媒体の方向へ凸形状となる正のメニス
カスレンズである光ピツクアップ用対物レンズ。(1) Consisting of a second lens, a second lens, and a third lens arranged on the same axis, the first lens and the second lens are both plano-convex lenses with one surface having a flat surface, and the third lens is an object to the recording medium. is an optical pickup objective lens that is a positive meniscus lens that is convex in the direction of the recording medium. （２）第２レンズと第３レンズは以下の条件を満足する
ものである特許請求の範囲第（り項記載の光ピックアッ
プ用対物しイス。 ■１．０ｊ＜　ｒ３　＜　１．２ｆ ■−１，７ｆ　＜　ｒ５　＜−１，４ｆ■　ｆ３＜１０
．Ｏｆ ただし、ｆは全系の焦点距離、ｒ３は第２レンズの凸面
の曲率半径、ｒ５は第３レンズにおける第２レンズ側の
面の曲率半径、ｆ３は第３レンズの焦点距離である。(2) An objective chair for an optical pickup according to claim 1, wherein the second lens and the third lens satisfy the following conditions. ■1.0j<r3<1.2f ■-1 ,7f<r5<-1,4f■ f3<10
．． Of, where f is the focal length of the entire system, r3 is the radius of curvature of the convex surface of the second lens, r5 is the radius of curvature of the surface of the third lens on the second lens side, and f3 is the focal length of the third lens. （３）第ルンズ、第２レンズおよび第３レンズが同一材
料によって形成されている特許請求の範囲第（１）項ま
たは第（２）項記載の光ピツクアップ用対物レンズ。(3) The objective lens for optical pickup according to claim (1) or (2), wherein the first lens, the second lens, and the third lens are formed of the same material.
JP59032203A 1984-02-22 1984-02-22 Objective lens for optical pickup Pending JPS60176012A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59032203A JPS60176012A (en) 1984-02-22 1984-02-22 Objective lens for optical pickup

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59032203A JPS60176012A (en) 1984-02-22 1984-02-22 Objective lens for optical pickup

Publications (1)

Publication Number Publication Date
JPS60176012A true JPS60176012A (en) 1985-09-10

Family

ID=12352345

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59032203A Pending JPS60176012A (en) 1984-02-22 1984-02-22 Objective lens for optical pickup

Country Status (1)

Country Link
JP (1) JPS60176012A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109782422A (en) * 2017-11-14 2019-05-21 新巨科技股份有限公司 The infrared Single wavelength of three-chip type projects lens set

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109782422A (en) * 2017-11-14 2019-05-21 新巨科技股份有限公司 The infrared Single wavelength of three-chip type projects lens set
CN109782422B (en) * 2017-11-14 2021-02-26 新巨科技股份有限公司 Three-piece infrared single-wavelength projection lens set

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