JPS6334441B2 - - Google Patents
Info
- Publication number
- JPS6334441B2 JPS6334441B2 JP54002665A JP266579A JPS6334441B2 JP S6334441 B2 JPS6334441 B2 JP S6334441B2 JP 54002665 A JP54002665 A JP 54002665A JP 266579 A JP266579 A JP 266579A JP S6334441 B2 JPS6334441 B2 JP S6334441B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- beam splitter
- polarizing beam
- polarizing
- information
- 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
Links
- 230000003287 optical effect Effects 0.000 claims description 18
- 230000010287 polarization Effects 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 3
- 238000000576 coating method Methods 0.000 claims description 3
- ORUIBWPALBXDOA-UHFFFAOYSA-L magnesium fluoride Chemical compound [F-].[F-].[Mg+2] ORUIBWPALBXDOA-UHFFFAOYSA-L 0.000 claims description 2
- 229910001635 magnesium fluoride Inorganic materials 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 2
- 229910021532 Calcite Inorganic materials 0.000 claims 1
- 239000010445 mica Substances 0.000 claims 1
- 229910052618 mica group Inorganic materials 0.000 claims 1
- 239000010453 quartz Substances 0.000 claims 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
Landscapes
- Optical Head (AREA)
Description
本発明は読取装置用偏光ビームスプリツタに関
し、さらに詳しくは、ビデオデイスク等に記録さ
れている情報を読取る場合に情報に含まれている
反射光を分離するのに用いられる偏光ビームスプ
リツタに関するものである。
The present invention relates to a polarizing beam splitter for a reading device, and more particularly to a polarizing beam splitter used to separate reflected light contained in information when reading information recorded on a video disk or the like. It is.
ビデオデイスク装置は、デイスク円板に情報を
微細な凹凸、いわゆるピツトとして記録したもの
であり、このビデオデイスクに記録されている情
報を光学的に読取る場合には、光源から放射され
る光を集束して情報記録トラツクに照射し、その
反射光を検出して情報を読取る構成が用いられて
いる。そして、従来一般に用いられている情報読
取装置は、第１図に示されているように、光源１
から放射された光線を偏光ビームスプリツタ２を
介して波長板３に供給することにより位相変化を
与え、この波長板３を通過した光線４は、対物レ
ンズ５において集束されて情報記録媒体としての
ビデオデイスク６の表面に微小スポツトとして照
射される。この場合、ビデオデイスク６の表面
は、記録情報に対応したピツトが形成されている
ために、スポツト状に照射された光線の反射光は
前記ピツトによつて変調を受けることになる。こ
のようにビデオデイスク６の反射光は、再び対物
レンズを通過した後に波長板３においてさらに位
相変化を与えられ、偏光ビームスプリツタ２に供
給される。
偏光ビームスプリツタ２は、波長板３を通過
し、所定量の位相変化を受けた反射光７を分離し
て受光素子８に供給する。
従つて、受光素子８に入力される入射光は、ビ
デオデイスク６のビツトに対応してその光量が変
化する光となり、受光素子８からは記録情報に対
応した電気信号が出力されることになる。
この場合、上述した偏光ビームスプリツタ２
は、第１図に示すように、遮光性の良いガラスに
よつて作られた三角柱２ａ，２ｂの長辺を互いに
接合した状態で貼り合せ、その貼り合せ面に多層
コーテイングを施すことによつて偏光作用が付与
され、この偏光ビームスプリツタ２は、波長板３
の光源側に配置された構成になつている。
A video disc device records information on a disc disc as minute irregularities, so-called pits, and when reading the information recorded on this video disc optically, the light emitted from the light source is focused. A configuration is used in which the information is read by illuminating the information recording track and detecting the reflected light. As shown in FIG. 1, a conventional information reading device generally used has a light source 1
A phase change is applied by supplying the light rays emitted from the wavelength plate 3 via the polarizing beam splitter 2, and the light rays 4 that have passed through the wave plate 3 are focused by the objective lens 5 and used as an information recording medium. The surface of the video disc 6 is irradiated as a minute spot. In this case, since pits corresponding to recorded information are formed on the surface of the video disc 6, the reflected light of the light beam irradiated in a spot shape is modulated by the pits. In this way, the reflected light from the video disk 6 passes through the objective lens again, undergoes a further phase change in the wave plate 3, and is supplied to the polarizing beam splitter 2. The polarizing beam splitter 2 separates the reflected light 7 that has passed through the wavelength plate 3 and has undergone a predetermined amount of phase change, and supplies the separated light to the light receiving element 8 . Therefore, the incident light input to the light-receiving element 8 becomes light whose intensity changes depending on the bit of the video disk 6, and the light-receiving element 8 outputs an electrical signal corresponding to the recorded information. . In this case, the above-mentioned polarizing beam splitter 2
As shown in Fig. 1, the long sides of triangular prisms 2a and 2b made of glass with good light-shielding properties are bonded together, and a multilayer coating is applied to the bonded surfaces. A polarizing beam splitter 2 is provided with a polarizing effect, and a wave plate 3
The configuration is such that it is placed on the side of the light source.
しかしながら、上記構成による情報読取装置に
用いられる偏光ビームスプリツタは、三角柱を２
個組合せて構成する関係上、加工面が10面、研磨
面が６面、コーテイング面が６面と工程数が多く
なり、各面の角度精度および加工精度を十分に得
ることが困難であつた。
また、三角柱の一面を互いに貼り合せることか
ら、この貼り合せ面に空気等が混入されて光学的
不良が生じやすく、さらに、三角柱を２個組合せ
て構成する関係止、外形寸法の精度が上らず、こ
れに伴つて該偏光ビームスプリツタの交換時に光
軸ずれが生じてしまう等の種々の欠点を有してい
た。
また、偏光ビームスプリツタの他に波長板を必
要とするため、部品数が多く製造工程が多い他、
製造コストも増加するといつた欠点も有してい
た。
そこで、本発明は、構成が簡単で製作工程数が
少なく、加工が容易であると共に、交換時におけ
る光軸ずれが生じない読取装置用偏光ビームスプ
リツタを提供すると共に、加えて波長板を一体化
した読取装置用偏光ビームスプリツタを提供し、
以て部品数を減らし、製造工程、製造コストを低
減し得る読取装置用偏光ビームスプリツタを提供
することを目的とするものである。
However, the polarizing beam splitter used in the information reading device with the above configuration splits the triangular prism into two.
Due to the combination of individual parts, the number of processes was large: 10 surfaces to be machined, 6 surfaces to be polished, and 6 surfaces to be coated, making it difficult to obtain sufficient angular accuracy and processing accuracy for each surface. . In addition, since one side of the triangular prisms is bonded to each other, air, etc. may be mixed into the bonded surfaces, which can easily cause optical defects.Furthermore, the precision of the external dimensions and the relationship between the two triangular prisms assembled by combining them is increased. First, there are various drawbacks associated with this, such as optical axis misalignment occurring when the polarizing beam splitter is replaced. In addition, it requires a wavelength plate in addition to a polarizing beam splitter, which requires a large number of parts and many manufacturing steps.
It also had the disadvantage of increasing manufacturing costs. SUMMARY OF THE INVENTION Therefore, the present invention provides a polarizing beam splitter for a reading device that has a simple configuration, a small number of manufacturing steps, is easy to process, and does not cause optical axis deviation during replacement. We provide polarizing beam splitters for reading devices that are
It is an object of the present invention to provide a polarizing beam splitter for a reading device that can reduce the number of parts and reduce the manufacturing process and manufacturing cost.
上述のような目的を達成するために、この発明
は、光源から情報記録媒体に供給される情報読取
光の光路中に斜めに配置され、通過する上記情報
読取光に1/4波長相当の位相変化を与える平行平
板状の光学素子と、その一面に形成された偏光面
とからなり、光源より放射された情報読取光を前
記偏光面側から前記光学素子を通過させ、前記情
報記録媒体を経由した前記情報読取光を前記偏光
面とは反対側から前記光学素子を通過させ、前記
偏光面により反射させることを特徴とするもので
ある。
In order to achieve the above-mentioned object, the present invention is arranged obliquely in the optical path of the information reading light supplied from the light source to the information recording medium, and has a phase equivalent to 1/4 wavelength of the information reading light passing therethrough. It consists of a parallel plate-shaped optical element that provides change and a polarization plane formed on one surface of the optical element, and the information reading light emitted from the light source is passed through the optical element from the polarization plane side and then via the information recording medium. The information reading light is caused to pass through the optical element from the side opposite to the polarization plane, and is reflected by the polarization plane.
以下、本発明の構成を第２図、第３図に示す実
施例により説明する。先ず、第２図は本発明によ
る情報読取装置用偏光ビームスプリツタの一実施
例を示し、この偏光ビームスプリツタは、通過光
に対して所定の位相変化を与える水晶、雲母、方
解石等の光学的材料よつて作られた光学素子とし
ての平行平面板１０の一面に、フツ化マグネシウ
ム、酸化ジルコン等の多層膜をコーテイングする
ことによつて偏光面１１を形成したものである。
この偏光ビームスプリツタは、光軸１２に対して
所定角度（例えば45度）に傾斜させて配置されて
いる。
光源２１から放射された光線（入射光）２２
は、平行平面板１０を通過して対物レンズ２３を
介してビデオデイスク２４は放射されるが、平行
平面板１０を通過する際その平行平面上において
偏光される一方、入射光２２に対して透過光２５
は所定の位相変化（例えばλ／４、λは波長）を
受ける。そして、このビデオデイスク２４の表面
において、ピツトによる記録情報に対応して変調
された反射光２６は、前記対物レンズ２５を再び
通過し、平行平面板１０に戻つてくる。このとき
該反射光２６は、平行平面板１０によつてさらに
所定の位相変化を受け（従つて、入射光に対して
反射光はλ／２の位相変化を受け）、偏光面１１
上で反射され、光線２７として受光素子２８へ供
給される。受光素子２８は、入射光２７をその強
さに対応した電気信号に変化することにより読取
信号を出力する。この場合、偏光ビームスプリツ
タは、平行平面板１０によつて構成されているた
めに、構造が極めて簡単であり、両面の平行度を
１分以内に容易に抑えることができ、これに伴つ
て光束角度ぶれを±0.6分以内、板厚変化による
光束平行移動量を±0.03分以内に抑えることがで
きる。このために、偏光ビームスプリツタを交換
しても、光軸はほとんど変化することがない。
Hereinafter, the structure of the present invention will be explained with reference to the embodiments shown in FIGS. 2 and 3. First, FIG. 2 shows an embodiment of a polarizing beam splitter for an information reading device according to the present invention. A polarizing plane 11 is formed by coating a multilayer film of magnesium fluoride, zirconium oxide, etc. on one surface of a plane-parallel plate 10 as an optical element made of an optical material.
This polarizing beam splitter is arranged to be inclined at a predetermined angle (for example, 45 degrees) with respect to the optical axis 12. Light rays (incident light) 22 emitted from the light source 21
The video disk 24 passes through the parallel plane plate 10 and is emitted via the objective lens 23, but when passing through the parallel plane plate 10, it is polarized on the parallel plane, while the incident light 22 is transmitted. light 25
undergoes a predetermined phase change (for example, λ/4, where λ is the wavelength). Then, on the surface of the video disk 24, the reflected light 26 modulated in accordance with the information recorded by the pits passes through the objective lens 25 again and returns to the parallel plane plate 10. At this time, the reflected light 26 is further subjected to a predetermined phase change by the parallel plane plate 10 (therefore, the reflected light undergoes a phase change of λ/2 with respect to the incident light), and the polarization plane 11
It is reflected at the top and is supplied to the light receiving element 28 as a light beam 27. The light receiving element 28 outputs a read signal by converting the incident light 27 into an electrical signal corresponding to its intensity. In this case, since the polarizing beam splitter is constituted by the parallel plane plate 10, the structure is extremely simple, and the parallelism on both sides can be easily suppressed within one minute. The angular deviation of the light beam can be suppressed to within ±0.6 minutes, and the amount of parallel movement of the light beam due to changes in plate thickness can be suppressed to within ±0.03 minutes. For this reason, even if the polarizing beam splitter is replaced, the optical axis hardly changes.
以上説明したように、本発明による読取装置用
偏光ビームスプリツタは、平行平面板１０の表面
に多層膜をコーテイングする構成であるために、
加工面が１面、研磨面が２面、コーテイング面が
２面となつて、それぞれが前述した従来の場合に
比較して大幅に少なくなり、これによつて工程数
が減り加工が容易で、かつ、精度も高くなると共
に、外形寸法を正確に規定することができるため
に、偏光ビームスプリツタを交換した場合におけ
る光軸ずれが生じない。
また、本発明によれば、偏光ビームスプリツタ
には貼付部分がないためその製造が極めて容易に
なり、製造コストを大幅に下げることができる等
の種々の優れた効果を有する。
さらにまた、本発明によれば、波長板を一体化
したため波長板が不必要となり、部品数を少なく
することができ、従つて、情報読取装置の製造工
程、製造コストを低減することができる。
As explained above, since the polarizing beam splitter for a reading device according to the present invention has a structure in which a multilayer film is coated on the surface of the parallel plane plate 10,
There is one processed surface, two polished surfaces, and two coated surfaces, each of which is significantly smaller than in the conventional case described above, which reduces the number of steps and facilitates processing. Moreover, since the accuracy is increased and the external dimensions can be accurately defined, optical axis deviation does not occur when the polarizing beam splitter is replaced. Further, according to the present invention, since the polarizing beam splitter does not have a pasting part, it is extremely easy to manufacture, and has various excellent effects such as being able to significantly reduce manufacturing costs. Furthermore, according to the present invention, since the wavelength plate is integrated, the wavelength plate is unnecessary, and the number of parts can be reduced, and therefore, the manufacturing process and manufacturing cost of the information reading device can be reduced.
第１図は従来の情報読取装置の一例を示す要部
構成図、第２図は本発明による情報読取装置の一
実施例を示す要部構成図、第３図は同偏光ビーム
スプリツタの斜面図である。
１０……平行平面板、１１……偏光面。
Fig. 1 is a block diagram of main parts showing an example of a conventional information reading device, Fig. 2 is a block diagram of main parts showing an example of an information reading device according to the present invention, and Fig. 3 is a slope of the polarizing beam splitter. It is a diagram. 10... Parallel plane plate, 11... Polarizing plane.
Claims (1)
光の光路中に斜めに配置され、通過する上記情報
読取光に1/4波長相当の位相変化を与える平行平
板状の光学素子と、その一面に形成された偏光面
とからなり、光源より放射された情報読取光を前
記偏光面側から前記光学素子を通過させ、前記情
報記録媒体を経由した前記情報読取光を前記偏光
面とは反対側から前記光学素子を通過させ、前記
偏光面により反射させることを特徴とする読取装
置用偏光ビームスプリツタ。 ２ 前記光学素子は、水晶、雲母、方解石等の光
学材料よりなることを特徴とする特許請求の範囲
第１項記載の読取装置用偏光ビームスプリツタ。 ３ 前記偏光面は、フツ化マグネシウム、酸化ジ
ルコン等の多層膜をコーテイングすることによつ
て形成されたことを特徴とする特許請求の範囲第
１項記載の読取装置用偏光ビームスプリツタ。[Scope of Claims] 1. Parallel plate-shaped optics arranged obliquely in the optical path of the information reading light supplied from the light source to the information recording medium and giving a phase change equivalent to 1/4 wavelength to the information reading light passing through it. The information reading light emitted from the light source passes through the optical element from the polarization plane side, and the information reading light that has passed through the information recording medium is converted into the polarized light. A polarizing beam splitter for a reading device, wherein light passes through the optical element from the opposite side to the polarizing surface and is reflected by the polarizing surface. 2. The polarizing beam splitter for a reading device according to claim 1, wherein the optical element is made of an optical material such as quartz, mica, or calcite. 3. The polarizing beam splitter for a reading device according to claim 1, wherein the polarizing plane is formed by coating a multilayer film of magnesium fluoride, zirconium oxide, or the like.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP266579A JPS5595913A (en) | 1979-01-13 | 1979-01-13 | Polarizing beam splitter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP266579A JPS5595913A (en) | 1979-01-13 | 1979-01-13 | Polarizing beam splitter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5595913A JPS5595913A (en) | 1980-07-21 |
| JPS6334441B2 true JPS6334441B2 (en) | 1988-07-11 |
Family
ID=11535608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP266579A Granted JPS5595913A (en) | 1979-01-13 | 1979-01-13 | Polarizing beam splitter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5595913A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6089841A (en) * | 1983-10-21 | 1985-05-20 | Toyo Commun Equip Co Ltd | Reflected light partial feedback light isolator |
| JPH0444003A (en) * | 1990-06-11 | 1992-02-13 | Alps Electric Co Ltd | Optical device for optical pickup |
-
1979
- 1979-01-13 JP JP266579A patent/JPS5595913A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5595913A (en) | 1980-07-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH03157843A (en) | Optical pickup device | |
| US5726962A (en) | Compact optical pickup device with beam splitter | |
| USRE41193E1 (en) | Method for fabricating a prism and method for fabricating an optical system | |
| KR100286865B1 (en) | Optical head unit | |
| US5581403A (en) | Beam shaping and beam splitting device and optical head comprising the same | |
| JPS6117103A (en) | Polarizing beam splitter | |
| JPS6334441B2 (en) | ||
| JPS62141653A (en) | Light pickup | |
| JP2710809B2 (en) | Crossed diffraction grating and polarization rotation detector using the same | |
| JPH07121923A (en) | Optical-pickup head device | |
| US5249171A (en) | Opto-magnetic pick-up device including phase difference correcting means | |
| JPH01282756A (en) | Optical pickup | |
| JPH03252928A (en) | Optical pickup device | |
| JP3131994B2 (en) | Recorded information reading device | |
| JPH0328401Y2 (en) | ||
| US5199013A (en) | Optical head apparatus applicable to optical disc apparatus | |
| JPH0749627Y2 (en) | Optical pickup device | |
| JPH0391133A (en) | Optical information recording and reproducing device | |
| JP2793706B2 (en) | Optical head for magneto-optical disk | |
| JPH01243257A (en) | Optical pickup | |
| JPH11339300A (en) | Optical information recording and reproducing device | |
| JPS63187440A (en) | Optical head | |
| JPH04177623A (en) | Optical information recording/reproducing apparatus | |
| JPS63187427A (en) | Optical pickup | |
| JPS62226454A (en) | Photomagnetic recording and reproducing device |