JPS5915913A - Objective lens of optical high density recording and reproducing device - Google Patents
Objective lens of optical high density recording and reproducing deviceInfo
- Publication number
- JPS5915913A JPS5915913A JP12506582A JP12506582A JPS5915913A JP S5915913 A JPS5915913 A JP S5915913A JP 12506582 A JP12506582 A JP 12506582A JP 12506582 A JP12506582 A JP 12506582A JP S5915913 A JPS5915913 A JP S5915913A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- light source
- curvature
- inequality
- source side
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000003287 optical effect Effects 0.000 title claims description 8
- 230000005499 meniscus Effects 0.000 claims abstract description 6
- 230000004075 alteration Effects 0.000 abstract description 13
- 239000002131 composite material Substances 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 11
- 239000006059 cover glass Substances 0.000 description 6
- 241000283986 Lepus Species 0.000 description 1
- 210000003127 knee Anatomy 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/24—Optical objectives specially designed for the purposes specified below for reproducing or copying at short object distances
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Lenses (AREA)
Abstract
Description
【発明の詳細な説明】
本発明はビデオディスク等の光学式高密度記録再生装置
の対物レンズに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an objective lens for an optical high-density recording/reproducing device such as a video disc.
光学式高密度記録再生装置の対物レンズは、久。The objective lens of optical high-density recording and reproducing equipment is long-lasting.
−力レンズ等の制御駆動を必借とし必然的に小型軽量化
が要求される一方、上記制御駆動時におけるディスク面
への衝突などを避けるために作動距離が大きく、捷だ記
録再生の精確度金向」ニさせるためにNAの大きなもの
が要求される。本発明はこれらの要求に沿って、小型軽
量で作動距離が犬きく且つNAの大きな光掌弐箇密度記
録角生装置の対物レンズを提供するものである。- While it is necessary to use control drive such as a power lens, it is inevitably required to be smaller and lighter, but the working distance is long to avoid collisions with the disk surface during the control drive, and the accuracy of recording and playback is poor. A large NA is required to achieve "Kinmukai". In accordance with these requirements, the present invention provides an objective lens for an optical beam density recording angle generating device that is small and lightweight, has a long working distance, and has a large NA.
以下、本発明について説明する。本発明の対物レンズは
3枚のレンズより構成される。この3枚のレンズは光源
側から記録再生媒体側に向けて、第ルンズ、第2レンズ
、第3レンズの順に配置される。上記第ルンズは光源側
に凸曲を向けた負のメニスカスレンズにより、第2レン
ズは両凸レンズにより、第3レンズは光源側に凸面を向
けた正のメニスカスレンズにより各々構成される。The present invention will be explained below. The objective lens of the present invention is composed of three lenses. These three lenses are arranged in the order of the first lens, the second lens, and the third lens from the light source side toward the recording/reproducing medium side. The first lens is a negative meniscus lens with a convex surface facing the light source, the second lens is a biconvex lens, and the third lens is a positive meniscus lens with a convex surface facing the light source.
このような対物レンズにおいてζ上記第ルンズの記録再
生媒体側の曲率半径k rz、第2レンズの光源側の曲
率半径kr3、第3Vンズの光源側の曲率半径をr5、
第1及び第2レンズの合成焦点距入1tをfl +、2
、第3レンズの焦点距離をf’3、全レンズ系の焦点
距離をfとしたとき、本発明の対物レンズは次の3宋件
を満足する。In such an objective lens, the radius of curvature of the second lens on the recording/reproducing medium side is krz, the radius of curvature of the second lens on the light source side is kr3, the radius of curvature of the third lens on the light source side is r5,
The combined focal length 1t of the first and second lenses is fl +, 2
, the focal length of the third lens is f'3, and the focal length of the entire lens system is f, the objective lens of the present invention satisfies the following three conditions.
(i) 0.55 < ”2/ < 0.953
(h) o、21 < ”’ / yo、2 < 0
.dB(iii) 0.56 < r5/(< 0.
97上記の条件(1)は球面収差全良好に保つための条
件である。上限をこえると球面収差の補正不足、下限を
こえると補正過剰となる。(i) 0.55 <"2/< 0.953 (h) o, 21 <"' / yo, 2 < 0
.. dB(iii) 0.56 <r5/(< 0.
97 The above condition (1) is a condition for keeping all spherical aberrations in good condition. If the upper limit is exceeded, the spherical aberration will be under-corrected, and if the lower limit is exceeded, the spherical aberration will be over-corrected.
条件(11)は作動距離を犬きく保つための条件である
。上限分こえると作動距離が小さくなり、フォーカシン
グなどの制御駆動に支障全きたす。また下限をこえると
第3レンズの負荷が犬きくなり各収差補正が困難となる
。Condition (11) is a condition for keeping the working distance close. If the upper limit is exceeded, the working distance becomes smaller, which completely hinders control drives such as focusing. Moreover, when the lower limit is exceeded, the load on the third lens becomes severe, making it difficult to correct each aberration.
条件(iii)は像面湾曲の補正を良好に保つための条
件である。上限をこえると像面湾曲の補正過剰、下限を
こえると補正不足となる。Condition (iii) is a condition for maintaining good correction of field curvature. If the upper limit is exceeded, the field curvature will be over-corrected, and if the lower limit is exceeded, the field curvature will be under-corrected.
本発明の対9りJレンズは上記の3条件ヲ滴足すること
により、下記する実施例のように作動距離が大きく、且
つNAも大きな、所望の光学式高密度記録再生装置、t
tめ対物レンズが得られたものである。By adding the above three conditions, the pair 9-shaped J lens of the present invention can be used as a desired optical high-density recording/reproducing device with a large working distance and a large NA as shown in the embodiments below.
A t-th objective lens was obtained.
第1図MC第1笑施例を示す。図示しない光源は図の左
側に置力)れる。符号LJ、 T−rz、 詔は第ル
ンズ、第2レンズ、第3レンズである。符号Gはカバー
ガラス、符号Mは記録再生媒体を示す。符号rlW r
6は上記各レンズの曲率半径、符号rfr8はカバーガ
ラスGの表裏面の曲率半径、符号dl〜d5は上記各レ
ンズの面間距離、符号d6Fi第3レンズ込の記録再生
媒体側面からカバーガラスGの表面までの光軸上の距離
、符号d7J−jカバーガラスQの表裏面間の距離を各
々示す。FIG. 1 MC shows a first embodiment. A light source (not shown) is placed on the left side of the figure. The symbols LJ, T-rz, and imperial commands are the 1st lens, 2nd lens, and 3rd lens. The symbol G indicates a cover glass, and the symbol M indicates a recording/reproducing medium. Code rlW r
6 is the radius of curvature of each lens, code rfr8 is the radius of curvature of the front and back surfaces of the cover glass G, codes dl to d5 are the distances between the surfaces of each of the lenses, code d6Fi is the distance from the side of the recording/reproducing medium including the third lens to the cover glass G. The distance on the optical axis to the surface of d7J-j and the distance between the front and back surfaces of the cover glass Q are shown respectively.
これらの具体的数値は以下のとおりである。These specific figures are as follows.
rl = 1.898
d1=0.192 n1=1.78788 )’t
=25.5r2 = 1.088
d2=0.084
r3” 1.525
d3= 0.443 n2=1.61888
))z =60Jr4ニー5.282
d4== o、 175
r5二 0.788
+15=0.478 n3=1.82072
J/J=87.8r6= 1.994
d6=0.381
’r’7= 0O
d7= 0.8 n11)−1,51Q3””
(X)
尚、 f=1.ooo NA=0.6 WD
=0.88上記において、符号n1〜n3U各レンズL
1〜尾の屈折率、nQはカバーガラスGの屈折率、シI
〜シ3は各レンズL]〜馳のアツベ数を各々示し、また
WDは作動距離を示す。rl = 1.898 d1 = 0.192 n1 = 1.78788 )'t
=25.5r2 = 1.088 d2=0.084 r3" 1.525 d3= 0.443 n2=1.61888
)) z = 60 Jr4 knee 5.282 d4== o, 175 r5 two 0.788 +15=0.478 n3=1.82072
J/J=87.8r6= 1.994 d6=0.381 'r'7= 0O d7= 0.8 n11)-1,51Q3""
(X) Furthermore, f=1. ooo NA=0.6 WD
=0.88 In the above, symbols n1 to n3U each lens L
1 to tail refractive index, nQ is the refractive index of cover glass G,
3 indicates the Atsube number of each lens L], and WD indicates the working distance.
第2図に第2実施例を示す。符号Ll’ 、 L2’
、祐′は第ルンズ、第2レンズ、第3レンズを示し、他
の符号は第1実施例と全く同様である。FIG. 2 shows a second embodiment. Code Ll', L2'
, Yu' indicate the first lens, the second lens, and the third lens, and the other symbols are exactly the same as in the first embodiment.
これらの具体的数値は次のとおりである。These specific figures are as follows.
rl” 1.877
d1= 0.175 nl= 1.78738 J
t = 25.5ra =1.046
.12= 0.125
r3=: 1.505
d3= 0.452 n2= 1.6 l388
Ll = 60Ur4=−5,242
d4= 0.187
r5= 0.786
d5=0.439 n3=1.82072 シ
3=a7.ar5= 2.fi78
d6=0.450
r7− ″
dy=OJ
r8二 (資)
尚、f = 1.0(10、NA = 0.5 、
WD = 0.45次に各収差図について述べる。第1
実施例に対する収差図を第3図に、第2実施例に対する
収差図を第4図に各々示す。また、第1実施例の波面収
差の等高線図を第5図に、第2実施例の波面収差の等高
線図を第6図に各々示す。これらの波面収差に関する図
のうち、(イ)は像高h=oすなわち光軸上の、(ロ)
は周辺部のそれぞれにおける波面収差を1厘位置の等高
線図で示したものである。rl” 1.877 d1= 0.175 nl= 1.78738 J
t = 25.5ra = 1.046. 12= 0.125 r3=: 1.505 d3= 0.452 n2= 1.6 l388
Ll = 60Ur4 = -5,242 d4 = 0.187 r5 = 0.786 d5 = 0.439 n3 = 1.82072 C3 = a7. ar5=2. fi78 d6=0.450 r7-'' dy=OJ r82 (fund) In addition, f = 1.0 (10, NA = 0.5,
WD = 0.45 Next, each aberration diagram will be described. 1st
An aberration diagram for the example is shown in FIG. 3, and an aberration diagram for the second example is shown in FIG. 4. Further, a contour line diagram of the wavefront aberration of the first embodiment is shown in FIG. 5, and a contour line diagram of the wavefront aberration of the second embodiment is shown in FIG. 6, respectively. Among these diagrams regarding wavefront aberration, (a) shows the image height h=o, that is, on the optical axis, and (b)
is a contour map showing the wavefront aberration in each peripheral area at one position.
第1図は本発明の第1実施例を示す図、第2図は本発明
の第2実Mq例を示す図、第3図及び第4図は上記第1
及び第2実施例の収差図、第5図及び第6図は上記第1
及び第2実施例の波m]収走の等高線図である。
bl、塊、馳、 L12. L2j、招電0、レンズG
・・カバーガラス、 M・・・記録丙午媒体特許出願人
株式会社三協精機製作所
第1図
第2図 、6.。5
第3図
第4図
勧oo+a* −1=o、o12シNA”
(Lf AM As
第5図
中1(
(イ)
第6図
申i(
(イ)
11辺−(ロ)FIG. 1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing a second actual Mq example of the present invention, and FIGS. 3 and 4 are diagrams showing the first embodiment of the present invention.
and the aberration diagrams of the second embodiment, FIGS. 5 and 6 are the same as those of the first embodiment.
and wave m of the second embodiment] is a contour diagram of retraction. bl, lump, hase, L12. L2j, electrification 0, lens G
...Cover glass, M...Record Heigo media patent applicant Sankyo Seiki Seisakusho Co., Ltd. Figure 1 Figure 2, 6. . 5 Figure 3 Figure 4 Recommendation oo+a* -1=o, o12 si NA"
(Lf AM As 1 in Figure 5 ((a)) Figure 6 (i) ((a) 11th side - (b)
Claims (1)
ンズ、第3レンズを順次配してなり、上記第ルンズを光
源側に凸面を向けた負のメニスカス1/ンズ、第2レン
ズを両凸レンズ、第3v ンスk 光源側に凸■を向け
た正のメニスカスレンズにより構成し、 上記第ルンズの記録再生媒体側の曲率半径をr2、第2
レンズの光源側の曲率半径krv、第3レンズの光源側
の曲率半径をr5、第1及び第2レンズの合成焦点距離
をfl、2、第3レンズの焦点距離ヲf3、全レンズ系
の焦点距離をfとし1ことき・(i) 0.55 <
r2/ < 0.953 Ql) o21 < f3/ fl、2 < o、a3
(iii) 0.56 < r5/f(0,97な槍ト
ff:満足する光学式高密度記録再生装置、の対物レン
ズ。[Claims] A first lens, a second lens, and a third lens are sequentially arranged from the first light source toward the recording/reproducing medium, and the first lens has a negative meniscus 1/2 with a convex surface facing the light source. The second lens is a biconvex lens, and the third lens is a positive meniscus lens with a convex side facing the light source side.
The radius of curvature of the lens on the light source side is krv, the radius of curvature of the third lens on the light source side is r5, the combined focal length of the first and second lenses is fl, 2, the focal length of the third lens is f3, the focal point of the entire lens system Let the distance be f and 1. (i) 0.55 <
r2/ < 0.953 Ql) o21 < f3/ fl, 2 < o, a3
(iii) 0.56 < r5/f (0.97 ff: objective lens of an optical high-density recording/reproducing device.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12506582A JPS5915913A (en) | 1982-07-20 | 1982-07-20 | Objective lens of optical high density recording and reproducing device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP12506582A JPS5915913A (en) | 1982-07-20 | 1982-07-20 | Objective lens of optical high density recording and reproducing device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5915913A true JPS5915913A (en) | 1984-01-27 |
JPH0215044B2 JPH0215044B2 (en) | 1990-04-10 |
Family
ID=14900946
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP12506582A Granted JPS5915913A (en) | 1982-07-20 | 1982-07-20 | Objective lens of optical high density recording and reproducing device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5915913A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04219627A (en) * | 1990-04-20 | 1992-08-10 | Matsushita Electric Ind Co Ltd | Optical disk recording and reproducing device |
USRE37185E1 (en) | 1990-04-20 | 2001-05-22 | Matsushita Electric Industrial Co., Ltd. | Optical head |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57192415A (en) * | 1981-05-22 | 1982-11-26 | Matsushita Electric Works Ltd | Improvement of solvent resistance of thermoplastic resin |
-
1982
- 1982-07-20 JP JP12506582A patent/JPS5915913A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57192415A (en) * | 1981-05-22 | 1982-11-26 | Matsushita Electric Works Ltd | Improvement of solvent resistance of thermoplastic resin |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH04219627A (en) * | 1990-04-20 | 1992-08-10 | Matsushita Electric Ind Co Ltd | Optical disk recording and reproducing device |
USRE37185E1 (en) | 1990-04-20 | 2001-05-22 | Matsushita Electric Industrial Co., Ltd. | Optical head |
Also Published As
Publication number | Publication date |
---|---|
JPH0215044B2 (en) | 1990-04-10 |
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