JP2757504B2 - lens - Google Patents
lensInfo
- Publication number
- JP2757504B2 JP2757504B2 JP1307910A JP30791089A JP2757504B2 JP 2757504 B2 JP2757504 B2 JP 2757504B2 JP 1307910 A JP1307910 A JP 1307910A JP 30791089 A JP30791089 A JP 30791089A JP 2757504 B2 JP2757504 B2 JP 2757504B2
- Authority
- JP
- Japan
- Prior art keywords
- objective lens
- flange
- lens
- optical
- optical axis
- 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.)
- Expired - Fee Related
Links
Landscapes
- Optical Head (AREA)
- Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
Description
【発明の詳細な説明】 〔概 要〕 光ディスク装置の光学ヘッドに用いられる対物レンズ
に関し、 光学ヘッドに対物レンズを装着する場合の光軸の傾き
調整が容易な対物レンズの提供を目的とし、 光ディスク装置の光学ヘッドに用いられる対物レンズ
の光軸に対して直交する平面を有する鍔を前記対物レン
ズを周縁部に一体的に設け、前記鍔の平面に光の反射膜
を形成して構成する。The present invention relates to an objective lens used for an optical head of an optical disk device. The objective of the present invention is to provide an objective lens in which the inclination of an optical axis can be easily adjusted when the objective lens is mounted on the optical head. A flange having a plane perpendicular to the optical axis of the objective lens used in the optical head of the apparatus is provided integrally with the periphery of the objective lens, and a light reflecting film is formed on the plane of the flange.
〔産業上の利用分野〕 本発明は、光ディスク装置等に用いられる対物レンズ
に関する。[Industrial application field] The present invention relates to an objective lens used for an optical disk device or the like.
光ディスク装置の光学ヘッド内における対物レンズ
は、その光軸を常に光ディスクの記録面に対して精度よ
く垂直に保持されながらトラッキング駆動およびフォー
カシング駆動される。もし光ディスクの記録面に対する
光軸の傾きが大きくなると光学的収差（非点収差やコマ
収差等）が発生して各種の情報信号に乱れが生じるた
め、精度よく保持するように取付け位置が調整できる手
段の開発が望まれている。The objective lens in the optical head of the optical disk device is driven for tracking and focusing while its optical axis is always kept accurately perpendicular to the recording surface of the optical disk. If the inclination of the optical axis with respect to the recording surface of the optical disk becomes large, optical aberrations (astigmatism, coma aberration, etc.) are generated, and various information signals are disturbed. The development of means is desired.
第２図は従来の光ディスク装置内における光ディスク
と対物レンズとの相対位置を示す図である。以下構成、
動作の説明を理解し易くするために全図を通じて同一部
分には同一符号を付してその重複説明を省略する。図に
おいて、１は光ディスク装置の光学ヘッドに用いられる
対物レンズ、２は光ディスク、３は対物レンズの光軸を
示す。対物レンズ１は光ディスク装置に装着された光学
ヘッド内に取付けられた状態において、光ディスク２の
記録面に対してその光軸３が精度よく垂直を保持するよ
うに光学測定器を利用して取付位置の調整を行う。FIG. 2 is a diagram showing a relative position between an optical disk and an objective lens in a conventional optical disk device. The following configuration,
To facilitate understanding of the description of the operation, the same portions will be denoted by the same reference symbols throughout the drawings, and redundant description will be omitted. In the figure, reference numeral 1 denotes an objective lens used for an optical head of an optical disk device, 2 denotes an optical disk, and 3 denotes an optical axis of the objective lens. When the objective lens 1 is mounted in an optical head mounted on an optical disk device, the mounting position of the objective lens 1 is measured using an optical measuring device so that the optical axis 3 of the optical disk 3 is perpendicular to the recording surface of the optical disk 2 with high accuracy. Make adjustments.
第３図は従来の代表的な対物レンズの断面図を示す。
図において、４は対物レンズのレンズ部、５は対物レン
ズ１の光軸３に対して直交する平面を有する鍔であって
レンズ部４周縁部に同心円状に所要の厚みをもって一体
的に設けられている。６は鍔５の傾きを調整可能に支え
る支持部材であって光学ヘッド７を構成する部材の一部
分である。対物レンズ１はモールド形成されたものが多
く、光軸３と鍔５の平面部はかなりの精度で垂直度が保
証されている。FIG. 3 is a cross-sectional view of a conventional typical objective lens.
In the figure, reference numeral 4 denotes a lens portion of the objective lens, and 5 denotes a flange having a plane orthogonal to the optical axis 3 of the objective lens 1 and is provided concentrically and integrally at a peripheral portion of the lens portion 4 with a required thickness. ing. Reference numeral 6 denotes a support member that supports the inclination of the flange 5 so as to be adjustable, and is a part of a member that constitutes the optical head 7. In many cases, the objective lens 1 is formed by molding, and the flatness of the optical axis 3 and the flange 5 guarantees verticality with considerable accuracy.
第４図は従来の対物レンズの傾きを測定する方法の説
明図である。図において８は光ディスク装置内の光学ヘ
ッド取付基準面（ガイドレール等）であって、測定に際
しては光ディスク２を取り除き、光学ヘッド取付基準面
の所定位置に配置した光学ヘッド７に装着された対物レ
ンズ１の直上にオートコリメータ９を位置決めする。FIG. 4 is an explanatory view of a conventional method for measuring the tilt of an objective lens. In the figure, reference numeral 8 denotes an optical head mounting reference surface (a guide rail or the like) in the optical disk device. In measurement, the optical disk 2 is removed, and an objective lens mounted on the optical head 7 arranged at a predetermined position on the optical head mounting reference surface. The autocollimator 9 is positioned just above the position 1.
オートコリメータ９は自ら平行光を射出して測定対象
物である対物レンズ１の鍔５からの反射光を検知して鍔
５の傾き角を測定する装置である。The autocollimator 9 is a device that emits parallel light by itself, detects reflected light from the flange 5 of the objective lens 1 as an object to be measured, and measures the inclination angle of the flange 5.
オートコリメータ９から光学ヘッド取付基準面８に対
して垂直方向の平行光を対物レンズ１に照射し、対物レ
ンズ１に設けられた鍔５からの反射光を観測することに
より、光学ヘッド取付基準面８に対する鍔５の平面部の
傾きの測定を行う。By irradiating the objective lens 1 with parallel light perpendicular to the optical head mounting reference plane 8 from the autocollimator 9 and observing the reflected light from the flange 5 provided on the objective lens 1, the optical head mounting reference plane is obtained. The inclination of the flat portion of the flange 5 with respect to 8 is measured.
測定方法の詳細は朝倉書店1984年８月５日発行の「光
学的測定ハンドブック」著者；田幸敏治・他２名に記載
されているので省略するが、マイクロメータ等を併用す
ると高精度の傾き角の測定が容易に行えるから、このオ
ートコリメータを利用して光学ヘッドに対する対物レン
ズ１の位置決め調節を行なっていた。The details of the measurement method are described in Asakura Shoten's "Optical Measurement Handbook" published on August 5, 1984 by Toshiharu Tada and two others. Since the measurement can be easily performed, the positioning of the objective lens 1 with respect to the optical head is adjusted using this autocollimator.
従来の対物レンズ１の外形は一般にレンズ部の直径が
約3mm、鍔の直径が約5mm程度でオートコリメータは鍔の
平面部の面積と、その平面部の反射率（従来は約５％程
度）に依存する反射光を検出して傾きの測定を行うもの
である。近時光学ヘッドの小型化、すなわち対物レンズ
の小型化の強い要望があり、レンズ部の直径を約1mmに
する可能性の検討が進められている。ところがレンズ部
の直径の小型化に鍔の直径の小型化が伴うため鍔の平面
部の面積が小さくなる結果、オートコリメータが検出す
る反射光の光度が検出可能限界を下回ることになり、オ
ートコリメータの機能が働かなくなり、対物レンズの傾
き調節が困難になるという問題点がある。The outer shape of the conventional objective lens 1 generally has a lens diameter of about 3 mm and a flange diameter of about 5 mm. The autocollimator has an area of the flat part of the flange and a reflectance of the flat part (about 5% in the past). Is used to detect the reflected light depending on the angle and measure the inclination. In recent years, there has been a strong demand for miniaturization of optical heads, that is, miniaturization of objective lenses, and studies on the possibility of reducing the diameter of a lens portion to about 1 mm are being conducted. However, as the diameter of the lens is reduced and the diameter of the flange is reduced, the area of the flat portion of the flange is reduced. Function does not work, and it is difficult to adjust the tilt of the objective lens.
本発明は上記従来の問題点に鑑みて創作されたもの
で、光学ヘッドに対物レンズを装着する場合の光軸の傾
き調整が容易な対物レンズの提供を目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and has as its object to provide an objective lens that can easily adjust the inclination of an optical axis when an objective lens is mounted on an optical head.
第１図は本発明のレンズの外観図である。光軸に直交
する平面を有する鍔５を前記レンズの周縁部に設け、前
記鍔５の平面に光軸方向に反射する光の反射膜10を設け
て構成する。FIG. 1 is an external view of the lens of the present invention. A flange 5 having a plane perpendicular to the optical axis is provided on the periphery of the lens, and a reflective film 10 for reflecting light in the optical axis direction is provided on the plane of the flange 5.
鍔の平面に光軸方向に反射する光の反射膜を設けるこ
とにより、反射率を向上させ、オートコリメータが受光
する鍔の反射膜から受ける反射光量を増加させてレンズ
装着時のレンズの光軸の傾きを容易に測定することがで
きる。By providing a reflective film for light reflected in the optical axis direction on the flat surface of the collar, the reflectance is improved, and the amount of reflection received from the reflective film of the collar received by the autocollimator is increased, so that the optical axis of the lens when the lens is mounted. Can be easily measured.
以下本発明の実施例を図面によって詳述する。第１図
は本発明の対物レンズの外観図であって、第１図（ａ）
は平面図、第１図（ｂ）は側面断面図を示す。両図にお
いて、１は対物レンズであってレンズ部４と、レンズ部
４の光軸３に対して直交する平面を有しレンズ部４の周
縁部に一体的に設けられた鍔５と、その鍔５の平面部に
形成された反射膜10とから構成されている。反射膜10の
反射率は高い程好ましく、100％に近い反射率を得るた
めには例えば非金属の多層蒸着膜（誘電体多層蒸着膜）
が使用される。これは光学材料の研磨面を基板として、
その表面に基板材料の屈折率nS（例えば1.51）よりも高
い屈折率nHの物質（例えば酸化セリウム）と、低い屈折
率nLの物質（例えば弗化マグネシウム）を光学的な厚さ
（屈折率と厚さの積）が1/4波長になるように交互に重
ねて蒸着したものが知られている。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external view of an objective lens according to the present invention, and FIG.
1 is a plan view, and FIG. 1 (b) is a side sectional view. In both figures, reference numeral 1 denotes an objective lens, which is a lens portion 4, a flange 5 having a plane perpendicular to the optical axis 3 of the lens portion 4, and provided integrally with a peripheral portion of the lens portion 4. And a reflection film 10 formed on a flat surface of the flange 5. The reflectivity of the reflective film 10 is preferably as high as possible. In order to obtain a reflectivity close to 100%, for example, a non-metal multilayer vapor deposition film (dielectric multilayer vapor deposition film)
Is used. This uses the polished surface of the optical material as a substrate,
A material having a refractive index n H (for example, cerium oxide) and a material having a low refractive index n L (for example, magnesium fluoride) that are higher than the refractive index n S (for example, 1.51) of the substrate material are coated on the surface with an optical thickness (for example, magnesium fluoride). It is known that they are alternately stacked and vapor-deposited so that the product of the refractive index and the thickness) becomes 1/4 wavelength.
鍔５の平面部の面積減少率が少ない場合は、安価なア
ルミ膜の蒸着形成でも目的を達成することができる。When the area reduction rate of the flat part of the flange 5 is small, the purpose can be achieved even by vapor deposition of an inexpensive aluminum film.
以上の説明から明らかなように本発明によれば、対物
レンズの外形が小型化しレンズ鍔の平面部の面積が小さ
くなっても、反射光量を十分確保することが可能になる
ため、オートコリメータ等を使用してのレンズ光軸の傾
きの検出が可能となり光ディスク装置等の組立性向上に
寄与するところが大きい。As is apparent from the above description, according to the present invention, even if the outer diameter of the objective lens is reduced and the area of the flat portion of the lens flange is reduced, it is possible to sufficiently secure the amount of reflected light. Can be used to detect the inclination of the lens optical axis, which greatly contributes to the improvement of the assemblability of an optical disk device or the like.
第１図は本発明の対物レンズの外観図、 第２図は従来の光ディスク装置内における光ディスクと
対物レンズの相対位置を示す図、 第３図は従来の代表的な対物レンズの断面図、 第４図は従来の対物レンズの傾きを測定する方法の説明
図を示す。 第１図において、１は対物レンズ、５は鍔、10は反射膜
をそれぞれ示す。FIG. 1 is an external view of an objective lens of the present invention, FIG. 2 is a diagram showing a relative position between an optical disk and an objective lens in a conventional optical disk device, FIG. 3 is a cross-sectional view of a typical conventional objective lens, FIG. 4 is an explanatory view of a conventional method for measuring the tilt of an objective lens. In FIG. 1, reference numeral 1 denotes an objective lens, 5 denotes a flange, and 10 denotes a reflection film.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) G11B 7/135──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) G11B 7/135
Claims (1)
ズの周縁部に設け、前記鍔の平面に光軸方向に反射する
光の反射膜を設けたことを特徴とするレンズ。1. A lens, wherein a flange having a plane perpendicular to the optical axis is provided on a peripheral portion of the lens, and a reflection film for reflecting light in the optical axis direction is provided on the plane of the flange.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1307910A JP2757504B2 (en) | 1989-11-27 | 1989-11-27 | lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1307910A JP2757504B2 (en) | 1989-11-27 | 1989-11-27 | lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03168937A JPH03168937A (en) | 1991-07-22 |
| JP2757504B2 true JP2757504B2 (en) | 1998-05-25 |
Family
ID=17974644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1307910A Expired - Fee Related JP2757504B2 (en) | 1989-11-27 | 1989-11-27 | lens |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2757504B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017040791A (en) * | 2015-08-20 | 2017-02-23 | 株式会社ダイセル | Optical component and optical device including the same |
| JP6503026B2 (en) * | 2017-08-03 | 2019-04-17 | 株式会社ダイセル | Optical part and optical apparatus provided with the same |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60214431A (en) * | 1984-04-10 | 1985-10-26 | Toshiba Corp | Detector of lens position |
| JPS6176401U (en) * | 1984-10-24 | 1986-05-22 | ||
| JPS6446241A (en) * | 1987-04-17 | 1989-02-20 | Alps Electric Co Ltd | Method for fitting objective lens to optical pickup, optical pickup mounted with objective lens and objective lens to optical pickup |
-
1989
- 1989-11-27 JP JP1307910A patent/JP2757504B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03168937A (en) | 1991-07-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |