JPS61132530U - - Google Patents
Info
- Publication number
- JPS61132530U JPS61132530U JP1416185U JP1416185U JPS61132530U JP S61132530 U JPS61132530 U JP S61132530U JP 1416185 U JP1416185 U JP 1416185U JP 1416185 U JP1416185 U JP 1416185U JP S61132530 U JPS61132530 U JP S61132530U
- Authority
- JP
- Japan
- Prior art keywords
- light
- optical system
- parallel
- focus control
- receiving element
- 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
Links
- 238000001514 detection method Methods 0.000 claims description 6
- 230000003287 optical effect Effects 0.000 claims 5
- 230000004907 flux Effects 0.000 claims 2
- 238000010586 diagram Methods 0.000 description 8
Landscapes
- Optical Recording Or Reproduction (AREA)
Description
第１図はこの考案の一実施例を示す構成図、第
２図は本実施例におけるフオーカス誤差検出の原
理を示す図、第３図は従来のフオーカス誤差検出
装置を示す構成図、第４図は第３図における４分
割受光素子の照射状態を示す図、第５図はフオー
カス誤差検出特性を示す図、第６図は別の従来例
のフオーカス誤差検出装置を示す構成図、第７図
は第６図における４分割受光素子の照射状態を示
す図である。
１……光源、２……偏光ビームスプリツタ、３
……1/4波長板、４……対物レンズ、５……媒体
、６……円筒レンズ、７……４分割受光素子、８
……偏光膜、９……コリメータレンズ、１０……
集光レンズ。
Fig. 1 is a block diagram showing an embodiment of this invention, Fig. 2 is a diagram showing the principle of focus error detection in this embodiment, Fig. 3 is a block diagram showing a conventional focus error detection device, and Fig. 4 is a diagram showing the irradiation state of the four-division light receiving element in FIG. 3, FIG. 5 is a diagram showing focus error detection characteristics, FIG. 6 is a configuration diagram showing another conventional focus error detection device, and FIG. 7 is a diagram showing the focus error detection characteristics. FIG. 7 is a diagram showing the irradiation state of the four-division light-receiving element in FIG. 6; 1...Light source, 2...Polarizing beam splitter, 3
...1/4 wavelength plate, 4...Objective lens, 5...Medium, 6...Cylindrical lens, 7...4-split light receiving element, 8
...Polarizing film, 9...Collimator lens, 10...
Condenser lens.
Claims (1)
する第１の光学系と、該第１の光学系を介して導
かれた前記平行光束を集束して媒体に照射しかつ
前記媒体からの反射光を前記平行光束と分離する
第２の光学系と、該第２の光学系を介して導かれ
た前記反射光を一軸方向にのみ集束するフオーカ
ス制御用光束に変換する円筒レンズと、該円筒レ
ンズの焦点距離の２倍離れた位置に配置されて前
記フオーカス制御用光束を受光する受光素子とか
らなり、該受光素子の表面上における前記フオー
カス制御用光束の照射状態の変化を検出すること
により前記媒体の表面上での前記平行光束の集束
状態を検出することを特徴とするフオーカス誤差
検出装置。 a light source; a first optical system that converts the light emitted from the light source into a parallel beam; and a first optical system that focuses the parallel beam guided through the first optical system and irradiates it onto a medium, and a second optical system that separates the reflected light from the parallel light flux; a cylindrical lens that converts the reflected light guided through the second optical system into a focus control light flux that focuses only in one axis direction; comprising a light receiving element disposed at a position twice the focal length of the cylindrical lens to receive the focus control light beam, and detecting a change in the irradiation state of the focus control light beam on the surface of the light receiving element. A focus error detection device characterized by detecting a convergence state of the parallel light beam on the surface of the medium.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1416185U JPS61132530U (en) | 1985-02-05 | 1985-02-05 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1416185U JPS61132530U (en) | 1985-02-05 | 1985-02-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS61132530U true JPS61132530U (en) | 1986-08-19 |
Family
ID=30498833
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1416185U Pending JPS61132530U (en) | 1985-02-05 | 1985-02-05 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61132530U (en) |
-
1985
- 1985-02-05 JP JP1416185U patent/JPS61132530U/ja active Pending
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