JPH056257B2 - - Google Patents
Info
- Publication number
- JPH056257B2 JPH056257B2 JP58236165A JP23616583A JPH056257B2 JP H056257 B2 JPH056257 B2 JP H056257B2 JP 58236165 A JP58236165 A JP 58236165A JP 23616583 A JP23616583 A JP 23616583A JP H056257 B2 JPH056257 B2 JP H056257B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- photodetector
- disk
- lens
- optical head
- 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 - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 31
- 238000001514 detection method Methods 0.000 claims description 4
- 230000008878 coupling Effects 0.000 description 9
- 238000010168 coupling process Methods 0.000 description 9
- 238000005859 coupling reaction Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- 239000013078 crystal Substances 0.000 description 4
- 239000004065 semiconductor Substances 0.000 description 4
- 238000010897 surface acoustic wave method Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910013641 LiNbO 3 Inorganic materials 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
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
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/12004—Combinations of two or more optical elements
-
- 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
- G11B7/123—Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
- G11B7/124—Integrated head arrangements, e.g. with source and detectors mounted on the same substrate the integrated head arrangements including waveguides
- G11B7/1245—Integrated head arrangements, e.g. with source and detectors mounted on the same substrate the integrated head arrangements including waveguides the waveguides including means for electro-optical or acousto-optical deflection
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- General Physics & Mathematics (AREA)
- Automatic Focus Adjustment (AREA)
- Optical Recording Or Reproduction (AREA)
- Optical Head (AREA)
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は光デイスク等の光学的情報処理装置に
おける光記録あるいは再生を行なうための光学装
置に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an optical device for optical recording or reproduction in an optical information processing device such as an optical disk.
従来の光ヘツドを第１図、第５図に示す。第１
図において、半導体レーザ１の光はカツプリング
レンズ２により平行光となり、ミラー５で反射さ
れ、対物レンズ７により微小光スポツト６が形成
される。カツプリングレンズ２と対物レンズ間に
は回折格子３が配置されており微小光スポツト６
は３個のスポツトからなつている。微小光スポツ
トは回転記録媒体である光デイスク上に形成さ
れ、光デイスク上の情報を読み取るのに用いられ
る。光デイスク上の情報は複数のトラツク上に微
細なピツトと称される穴の形で記録されている。
この情報を精度良く読むためにはデイスク上に微
小光スポツトを形成するための自動焦点機能およ
び、微小光スポツトが所望のトラツク上を追随す
るためのトラツキング機能が必要である。図にお
いてデイスクからの反射光はハーフプリズム４に
より反射され、凸レンズ１１、シリンドリカルレ
ンズ１０を通り光検出器９に到達する。第３図に
第１図に示した凸レンズ１１、シリンドリカルレ
ンズ１０を用いた焦点誤差信号検出の動作原理を
示す。
A conventional optical head is shown in FIGS. 1 and 5. 1st
In the figure, light from a semiconductor laser 1 is turned into parallel light by a coupling lens 2, reflected by a mirror 5, and a minute light spot 6 is formed by an objective lens 7. A diffraction grating 3 is placed between the coupling lens 2 and the objective lens, and a minute light spot 6 is placed between the coupling lens 2 and the objective lens.
is made up of three spots. A minute optical spot is formed on an optical disk, which is a rotating recording medium, and is used to read information on the optical disk. Information on an optical disk is recorded in the form of minute holes called pits on multiple tracks.
In order to read this information accurately, an automatic focusing function for forming a minute light spot on the disk and a tracking function for making the minute light spot follow a desired track are required. In the figure, reflected light from the disk is reflected by a half prism 4, passes through a convex lens 11 and a cylindrical lens 10, and reaches a photodetector 9. FIG. 3 shows the operating principle of focus error signal detection using the convex lens 11 and cylindrical lens 10 shown in FIG. 1.
凸レンズ１１により絞られる点をＯ、円筒レン
ズ１０により絞られた点をＦとすると、Ｆ，Ｍ，
Ｏ点での光強度の断面分布形状はIF，IM，IOとな
る。いまデイスクと対物レンズ７との距離が理想
位置より小さくなる焦点誤差が生じた時、第３図
のＯ点、Ｆ点は凸レンズ１１から遠ざかる方向に
移動するため、Ｍ点での光強度の分布形状はIMか
らIFに近い形状に変化する。デイスクと対物レン
ズの距離が理想位置より大きくなつた時、Ｍ点で
はIOに近い形状となる。したがつてＭ点に第４図
１２に示した４分割光検知器１２を配置すると焦
点誤差が検出できる。すなわち、光検知器の４分
割部Da，Db，Dc，Ddの光出力電圧をＶ（Da），
Ｖ（Db），Ｖ（Dc），Ｖ（Dd）とすると、Ｖ（Da）＋
Ｖ（Dd）−（Ｖ（Db）＋Ｖ（Dc））により焦点誤差信
号が得られ、この信号により自動焦点機構が駆動
される。 If the point narrowed down by the convex lens 11 is O, and the point narrowed down by the cylindrical lens 10 is F, then F, M,
The cross-sectional distribution shapes of the light intensity at point O are I F , I M , and I O . Now, when a focus error occurs in which the distance between the disk and the objective lens 7 is smaller than the ideal position, points O and F in FIG. 3 move away from the convex lens 11, so the distribution of light intensity at point M changes. The shape changes from I M to a shape close to I F. When the distance between the disk and the objective lens becomes larger than the ideal position, the shape at point M becomes close to I O. Therefore, if the four-split photodetector 12 shown in FIG. 4 is placed at point M, the focus error can be detected. In other words, the optical output voltages of the four division parts Da, Db, Dc, and Dd of the photodetector are V (Da),
If V (Db), V (Dc), V (Dd), then V (Da) +
A focus error signal is obtained by V(Dd)-(V(Db)+V(Dc)), and this signal drives the autofocus mechanism.
トラツキング信号の検出は次のごとく行なわれ
る。デイスク上に形成される３個のスポツトはデ
イスク上のトラツクに対し第２図のごとく配置さ
れる。主スポツト１６はトラツク上にあり、サイ
ドスポツト１７はトラツク中心から少しはずれた
位置にあるよう光学系が設定されている。主スポ
ツト１６からの反射光は第４図に示す光検知器１
２で検知される。サイドスポツトは光検知器１
３，１４で検知される。 Detection of the tracking signal is performed as follows. The three spots formed on the disk are arranged with respect to the tracks on the disk as shown in FIG. The optical system is set so that the main spot 16 is located on the track, and the side spots 17 are located slightly off the center of the track. The reflected light from the main spot 16 is detected by the photodetector 1 shown in FIG.
Detected at 2. Side spot is photodetector 1
Detected at 3.14.
光検知器１３，１４の光検出電圧をそれぞれＶ
（De），Ｖ（Df）とする。トラツキングに誤差があ
る場合はＶ（De），Ｖ（Df）が等しくならず、トラ
ツキング信号Ｖ（De）−Ｖ（Df）が零になるように
トラツキング機構が動作する。 The photodetection voltage of the photodetectors 13 and 14 is set to V, respectively.
(De) and V(Df). If there is an error in tracking, V(De) and V(Df) are not equal, and the tracking mechanism operates so that the tracking signal V(De)-V(Df) becomes zero.
デイスクのトラツク上に記録されているピツト
信号は光検知器の出力Ｖ（Da）＋Ｖ（Db）＋Ｖ（Dc）
＋Ｖ（Dd）で検知される。 The pit signal recorded on the disk track is the output of the photodetector V (Da) + V (Db) + V (Dc)
Detected at +V (Dd).
第５図は従来の光ヘツドの別の例であり、この
ヘツドの動作はPhilips technical Review1982年
40巻、６号、151頁から156頁に詳しく述べられて
いる。 Figure 5 shows another example of a conventional optical head, and the operation of this head is described in the Philips technical review 1982.
It is described in detail in Volume 40, No. 6, pages 151 to 156.
第５図でLaは半導体レーザ、P1はビーム分割
器、Ｍは反射面、P2は２分割プリズム、L2はカ
ツプリングレンズ、L1はオブジユクテイブレン
ズ、Ｄはデイスク、Ｓは絞られた光スポツトを示
している。D1，D2，D3，D4は直線配置型４分割
光検知器Ｄのそれぞれの光検知器であり、これら
の光検知出力をそれぞれＶ（D1），Ｖ（D2），Ｖ
（D3），Ｖ（D4）とすると、信号成分はＶ（D1）＋Ｖ
（D2）＋Ｖ（D3）＋Ｖ（D4）、焦点誤差信号はＶ（D1）
＋Ｖ（D4）−（Ｖ（D2）＋Ｖ（D3））、トラツキング信
号はＶ（D1）＋Ｖ（D2）−（Ｖ（D3）＋Ｖ（D4））で得
られる。 In Figure 5, La is a semiconductor laser, P 1 is a beam splitter, M is a reflective surface, P 2 is a two-split prism, L 2 is a coupling lens, L 1 is an objective lens, D is a disk, and S is an aperture. It shows a light spot. D 1 , D 2 , D 3 , and D 4 are the respective photodetectors of the linearly arranged 4-split photodetector D, and their photodetection outputs are expressed as V(D 1 ), V(D 2 ), and V, respectively.
(D 3 ), V (D 4 ), the signal component is V (D 1 ) + V
(D 2 ) + V (D 3 ) + V (D 4 ), the focus error signal is V (D 1 )
+V( D4 )-(V( D2 )+V( D3 )), and the tracking signal is obtained as V( D1 )+V( D2 )-(V( D3 )+V( D4 )).
ところで、第１図、第５図で説明した従来の光
ヘツドはそれぞれ単品からなるレンズ、プリズ
ム、回折格子などを機構部の中に、所定の精度で
配置したものであるが、この配置精度を実現する
ための調整個所が多く、調整に長時間を要する欠
点がある。また、個々別々の単品部品を配置する
ため、光ヘツド全体の大きさも大きくなる欠点が
ある。 By the way, in the conventional optical head explained in FIGS. 1 and 5, individual lenses, prisms, diffraction gratings, etc. are arranged in a mechanical part with a predetermined precision. There are many adjustment points to achieve this, and the disadvantage is that it takes a long time to make adjustments. Furthermore, since individual components are arranged, there is a drawback that the overall size of the optical head becomes large.
本発明は上記した欠点を解消するためになされ
たもので、調整個所が少なく、低価格で大量生産
に適しかつ小さな光ヘツドを提供することにあ
る。
The present invention has been made to overcome the above-mentioned drawbacks, and its object is to provide a small optical head that requires fewer adjustment points, is suitable for mass production at low cost, and is suitable for mass production.
したがつて本発明では光導波器を形成し、光導
波路表面上に導波路レンズ、導波路格子などを露
光、現像プロセスで精度良く、集積化して製作、
配置できることに着目し、光導波路を利用した小
型の光ヘツドを提供しようとするものである。
Therefore, in the present invention, an optical waveguide is formed, and a waveguide lens, a waveguide grating, etc. are integrated on the surface of the optical waveguide with high precision through an exposure and development process.
The aim is to provide a compact optical head that utilizes an optical waveguide, focusing on the fact that it can be arranged easily.
以下、本発明の実施例を第６図により説明す
る。第６図は本発明の一実施例を示す図であり、
ａは平面図、ｂは側面図である。
An embodiment of the present invention will be described below with reference to FIG. FIG. 6 is a diagram showing an embodiment of the present invention,
A is a plan view, and b is a side view.
図において、１９はLiNbO3結晶のごとき強誘
電結晶で、結晶表面２６はTi拡散を施こし周囲
の屈折率よりわずかに高い屈折率を有しているた
め、光導波層として働く。 In the figure, numeral 19 is a ferroelectric crystal such as LiNbO 3 crystal, and the crystal surface 26 is Ti-diffused and has a refractive index slightly higher than the surrounding refractive index, so that it functions as an optical waveguide layer.
半導体レーザ１からの光は端面結合により光導
波層２６に導かれ、カツプリングレンズ２１、オ
ブジエクテイブレンズ２２によりデイスク２５上
に微小スポツトを形成する。カツプリング２１は
公知のジオデシツクレンズ、あるいは回折格子等
の導波路レンズであつてよい。オブジエクテイブ
レンズ２２は公知の回折格子からなるレンズであ
る。２３は弾性表面波を励振するための電極であ
り弾性表面波の周波数を変化させることにより弾
性表面波で回折し、デイスク上で形成された微小
スポツトがデイスク上のトラツクを追随するよう
にしている。 The light from the semiconductor laser 1 is guided to the optical waveguide layer 26 by end face coupling, and a minute spot is formed on the disk 25 by the coupling lens 21 and the objective lens 22. The coupling 21 may be a known geodesic lens or a waveguide lens such as a diffraction grating. The object lens 22 is a lens made of a known diffraction grating. 23 is an electrode for exciting surface acoustic waves, and by changing the frequency of the surface acoustic waves, the surface acoustic waves are diffracted so that minute spots formed on the disk follow tracks on the disk. .
デイスクから反射した光はオブジエクテイブレ
ンズ２２、カツプリングレンズ２１を通過し、屈
曲型回折格子２０で反射し直線配置型４分割光検
知器２４に入射する。屈曲型回折格子２０の片側
の直線部分からのレーザ光は直線配置型４分割光
検知器の片側の２個の光検知器部分へ、他の回折
格子の部分からのレーザ光は別の２個の光検知器
部分へ入射する。屈曲型回折格子２０の動作原理
は第５図に示したプリズムP2に対応するもので
ある。この動作原理を第７図で説明する。焦点誤
差信号は次のように検出される。オブジエクテイ
ブレンズにより絞られた光スポツトが正確にデイ
スク表面にある場合、デイスクから反射しもどつ
てくる光は第７図のＯ点に収束するようにもどつ
てくる。Ｏ点に収束するようにもどつてくる光の
一部は屈曲型回折格子２０により反射され直線配
置型４分割光検知器２４で検知される。この場
合、第７図実線で示すようにレーザ光は４分割検
知器のD1，D2の中間およびD3，D4の中間位置に
来るようになつている。 The light reflected from the disk passes through an objective lens 22 and a coupling lens 21, is reflected by a bent diffraction grating 20, and enters a linearly arranged four-part photodetector 24. Laser light from one straight portion of the bent diffraction grating 20 is directed to two photodetector portions on one side of the linearly arranged 4-split photodetector, and laser light from the other portion of the diffraction grating is directed to two other photodetector portions. The light enters the photodetector section of the photodetector. The operating principle of the bent diffraction grating 20 corresponds to that of the prism P2 shown in FIG. The principle of this operation will be explained with reference to FIG. The focus error signal is detected as follows. If the light spot focused by the objective lens is exactly on the disk surface, the light reflected from the disk will return to converge at point O in FIG. 7. A portion of the light that returns to converge at point O is reflected by the bent diffraction grating 20 and detected by the linearly arranged four-segment photodetector 24. In this case, as shown by the solid line in FIG. 7, the laser beam is arranged to come to the intermediate position between D 1 and D 2 and the intermediate position between D 3 and D 4 of the four-split detector.
オブジエクテイブレンズとデイスク間の距離が
正しい距離よりも小さくなるような焦点誤差が生
じた場合、デイスクから反射しもどつてくるレー
ザ光は第７図鎖線に示すようにＯ点より離れた点
（図ではO′点）に収束するようにもどつてくる。
この場合、鎖線に示すように光検知器２４にレー
ザ光が入射するため受光部D1，D2および受光部
D3，D4の光検知出力間に差異が生じる。すなわ
ち、D1，D2，D3，D4の光検知出力電圧をＶ
（D1），Ｖ（D2），Ｖ（D3），Ｖ（D4）とし、焦点誤
差信号AFを次式で得るとすると、
AF＝Ｖ（D1）＋Ｖ（D4）＋（Ｖ（D2）＋Ｖ（D3））…(1
)
この場合、AF＜Ｏとなる。 If a focus error occurs such that the distance between the objective lens and the disk is smaller than the correct distance, the laser beam reflected from the disk and returning will be directed to a point farther away from point O as shown by the chain line in Figure 7 (Figure 7). Then, it returns to converge to point O′).
In this case, as shown by the chain line, the laser beam is incident on the photodetector 24, so the light receiving parts D 1 , D 2 and the light receiving part
A difference occurs between the light detection outputs of D 3 and D 4 . In other words, the photodetection output voltages of D 1 , D 2 , D 3 , and D 4 are set to V
(D 1 ), V(D 2 ), V(D 3 ), V(D 4 ), and the focus error signal AF is obtained by the following formula: AF=V(D 1 )+V(D 4 )+( V(D 2 )+V(D 3 ))…(1
) In this case, AF<O.
逆に、オブジエクテイブレンズとデイスク間の
距離が正しい距離よりも大きくなるような焦点誤
差が生じた場合、AF＞Ｏとなる。 Conversely, if a focus error occurs such that the distance between the objective lens and the disk is larger than the correct distance, AF>O.
以上、説明したごとく焦点誤差信号は検出され
る。 As explained above, the focus error signal is detected.
トラツキング信号TRは次式で得られる。 The tracking signal TR is obtained by the following equation.
TR＝Ｖ（D1）＋Ｖ（D2）−（Ｖ（D3）＋Ｖ（D4））…(2
)
これは、光スポツトがデイスク上のトラツクか
ら少しずれた場合、デイスクからの反射光の屈曲
型回折格子上での光強度分布は屈曲型回折格子の
面側で一致しなくなり、式(2)のTRの正負により
トラツクずれの方向が検知できることによる。TR=V( D1 )+V( D2 )-(V( D3 )+V( D4 ))…(2
) This means that if the light spot deviates slightly from the track on the disk, the light intensity distribution of the reflected light from the disk on the bent diffraction grating will no longer match on the surface side of the bent diffraction grating, and Equation (2) This is because the direction of track deviation can be detected by the positive or negative sign of TR.
以上の如く、本発明によれば、光導波路を利用
しているので、導波路レンズ、導波路格子などの
光学部品を露光、現像プロセスで精度良く、集積
化して製作、配置することができ、調整個所が少
なく、低価格でかつ超小型の光ヘツドが容易に実
現できる。
As described above, since the present invention utilizes an optical waveguide, optical components such as waveguide lenses and waveguide gratings can be manufactured and arranged in an integrated manner with high accuracy through exposure and development processes. With fewer adjustment points, a low-cost, ultra-small optical head can be easily realized.
第１図は従来の光ヘツドを示す図、第２図は従
来のトラツキン原理を説明する図、第３図、第４
図は従来の自動焦点原理を説明するための図、第
５図は従来の他の光ヘツドを示す図、第６図及び
第７図は本発明による光ヘツドの一実施例を説明
する図である。
１…半導体レーザ、１９…強誘電結晶、２０…
屈曲型回折格子、２１…カツプリングレンズ、２
２…オブジエクテイブレンズ、２４…直線配置型
４分割光検知器、２６…光導波層。
Figure 1 is a diagram showing a conventional optical head, Figure 2 is a diagram explaining the conventional tracking principle, Figures 3 and 4.
The figure is a diagram for explaining the conventional autofocus principle, FIG. 5 is a diagram showing another conventional optical head, and FIGS. 6 and 7 are diagrams for explaining an embodiment of the optical head according to the present invention. be. 1... Semiconductor laser, 19... Ferroelectric crystal, 20...
Bent diffraction grating, 21... Coupling lens, 2
2...Objective lens, 24...Linear arrangement type 4-segment photodetector, 26...Optical waveguide layer.
Claims (1)
波路上に形成されて記録媒体からの光を第１の光
と第２の光に分割する屈曲型回折格子と、該第１
の光と第２の光を受光する直線配置型４分割光検
知器を有し、該直線配置型４分割光検知器の片側
の２個の光検知器部分で上記第１の光を受光し、
直線配置型４分割光検知器の他の片側の２個の光
検知器部分で上記第２の光を受光し、上記直線配
置型４分割光検知器からの４つの検出信号を演算
することにより焦点誤差信号及びトラツキング信
号を形成することを特徴とする光ヘツド。 ２ 前記直線配置型４分割光検知器の４個の光検
知器部分を順にD1，D2，D3，D4とし、その光検
知出力を順にＶ（D1），Ｖ（D2），Ｖ（D3），Ｖ（D4）
としたとき、前記第１の光を上記D1およびD2で
受光し、前記第２の光を上記D3およびD4で受光
し、前記焦点誤差信号AFを以下の演算で形成す
ることを特徴とする特許請求の範囲第１項記載の
光ヘツド。 演算： AF＝Ｖ（D1）＋Ｖ（D4）−（Ｖ（D2）＋Ｖ（D3）） ３ 前記直線配置型４分割光検知器の４個の光検
知器部分を順にD1，D2，D3，D4とし、その光検
知出力を順にＶ（D1），Ｖ（D2），Ｖ（D3），Ｖ（D4）
としたとき、前記第１の光を上記D1およびD2で
受光し、前記第２の光を上記D3およびD4で受光
し、前記トラツキング信号TRを以下の演算で形
成することを特徴とする特許請求の範囲第１項記
載の光ヘツド。 演算： TR＝Ｖ（D1）＋Ｖ（D2）−（Ｖ（D3）＋Ｖ（D4））[Claims] 1. A waveguide that transmits light from a recording medium, and a bent diffraction grating that is formed on the waveguide and splits the light from the recording medium into first light and second light. , the first
and a second light, and two photodetectors on one side of the linearly arranged four-part photodetector receive the first light. ,
By receiving the second light with the two photodetector parts on the other side of the linearly arranged 4-part photodetector and calculating the four detection signals from the linearly arranged 4-part photodetector. An optical head characterized in that it forms a focus error signal and a tracking signal. 2 The four photodetector portions of the linearly arranged four-part photodetector are designated as D 1 , D 2 , D 3 , and D 4 in this order, and their photodetection outputs are designated as V (D 1 ) and V (D 2 ) in this order. , V(D 3 ), V(D 4 )
Then, the first light is received by D1 and D2 , the second light is received by D3 and D4 , and the focus error signal AF is formed by the following calculation. An optical head according to claim 1, characterized in: Calculation: AF=V( D1 )+V( D4 )-(V( D2 )+V( D3 ) ) D 2 , D 3 , D 4 and their photodetection outputs are V (D 1 ), V (D 2 ), V (D 3 ), V (D 4 ) in order.
, the first light is received by the D 1 and D 2 , the second light is received by the D 3 and D 4 , and the tracking signal TR is formed by the following calculation. An optical head according to claim 1. Calculation: TR=V( D1 )+V( D2 )-(V( D3 )+V( D4 ))
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58236165A JPS60129938A (en) | 1983-12-16 | 1983-12-16 | light head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58236165A JPS60129938A (en) | 1983-12-16 | 1983-12-16 | light head |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4090607A Division JPH05101416A (en) | 1992-04-10 | 1992-04-10 | Optical head |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60129938A JPS60129938A (en) | 1985-07-11 |
| JPH056257B2 true JPH056257B2 (en) | 1993-01-26 |
Family
ID=16996728
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58236165A Granted JPS60129938A (en) | 1983-12-16 | 1983-12-16 | light head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60129938A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0795372B2 (en) * | 1984-06-27 | 1995-10-11 | キヤノン株式会社 | Optical head device |
| JPS6289250A (en) * | 1985-10-16 | 1987-04-23 | Fuji Photo Film Co Ltd | Pickup for optical disk |
| JPH0743845B2 (en) * | 1985-12-16 | 1995-05-15 | キヤノン株式会社 | Optical head device |
| JPS632128A (en) * | 1986-06-20 | 1988-01-07 | Matsushita Electric Ind Co Ltd | light pick up |
| JP2594970B2 (en) * | 1986-09-09 | 1997-03-26 | 株式会社日立製作所 | Thin-film optical waveguide type optical head |
| JPH0622065B2 (en) * | 1987-02-25 | 1994-03-23 | 株式会社日立製作所 | Integrated optical head |
| US5191624A (en) * | 1990-09-19 | 1993-03-02 | Hitachi, Ltd. | Optical information storing apparatus and method for production of optical deflector |
| JP2828227B2 (en) * | 1996-11-18 | 1998-11-25 | オリンパス光学工業株式会社 | Light head |
-
1983
- 1983-12-16 JP JP58236165A patent/JPS60129938A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60129938A (en) | 1985-07-11 |
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