JPH0519857Y2

JPH0519857Y2 -

Info

Publication number: JPH0519857Y2
Application number: JP1984014294U
Authority: JP
Priority date: 1984-02-03
Filing date: 1984-02-03
Publication date: 1993-05-25
Also published as: JPS60127634U

Description

【考案の詳細な説明】技術分野この考案は記録情報再生装置に関し、特に情報
検出用の光ビームの光軸と記録デイスクとの直交
関係を維持するいわゆるチルトサーボを有する光
学式記録情報再生装置に関する。[Detailed Description of the Invention] Technical Field This invention relates to a recorded information reproducing device, and more particularly to an optical recorded information reproducing device having a so-called tilt servo that maintains an orthogonal relationship between the optical axis of a light beam for information detection and a recording disk.

背景技術情報検出用の光ビームの光軸と記録デイスクと
の間のなす角が直角からずれると、隣接記録トラ
ツクからの情報が漏洩してクロストーク現象が生
じる。そこで、この直交関係を検出してビーム光
軸とデイスクとの直交関係を常に正確に維持して
クロストークを軽減するチルトサーボ系が設けら
れる。BACKGROUND ART When the angle between the optical axis of a light beam for information detection and a recording disk deviates from a right angle, information from adjacent recording tracks leaks, resulting in a crosstalk phenomenon. Therefore, a tilt servo system is provided that detects this orthogonal relationship and always accurately maintains the orthogonal relationship between the beam optical axis and the disk to reduce crosstalk.

このサーボ系は、当該直交関係からのずれを検
出する検出手段と、この検出出力に応じてビーム
光軸を傾斜せしめる傾斜手段とからなつている。
この検出手段としては、発射光を記録デイスクへ
向けて照射する発光素子と、この発射光のデイス
クによる反射光を受光すべくこの受光素子の両側
に設置された一対の受光素子からなり、この受光
出力の差によつて傾斜手段を制御するようになつ
ている。 This servo system consists of a detection means for detecting a deviation from the orthogonal relationship, and a tilting means for tilting the beam optical axis in accordance with the detected output.
This detection means consists of a light emitting element that emits emitted light toward the recording disk, and a pair of light receiving elements installed on both sides of this light receiving element to receive the reflected light of the emitted light from the disk. The tilting means is controlled by the difference in output.

この場合、検出手段は情報検出用の光ビームの
光軸近傍にあつてこの光ビームの光軸とデイスク
の直交関係を正しく検出することが要求される
が、デイスクの内外周で記録トラツクすなわちピ
ツトのある部分と無い部分とにより反射率に差が
あるため、受光素子に入射する反射光量に差を生
じサーボ系の誤動作を招来する。 In this case, the detection means is required to be located near the optical axis of the light beam for information detection and to correctly detect the orthogonal relationship between the optical axis of the light beam and the disk. Since there is a difference in reflectance between the portion with and without it, there is a difference in the amount of reflected light incident on the light receiving element, leading to malfunction of the servo system.

考案の概要そこで、本考案は傾斜検出光ビームすなわち発
射光のデイスク上におけるビーム径を所望に設定
することによつてデイスクの内外周においても正
確なチルトサーボ信号を発生可能な記録情報再生
装置を提供することを目的とする。Summary of the invention Therefore, the present invention provides a recorded information reproducing device that can generate accurate tilt servo signals even on the inner and outer peripheries of the disk by setting the beam diameter of the tilt detection light beam, that is, the emitted light, on the disk as desired. The purpose is to

本考案による記録情報再生装置は、少なくとも
プログラム部分において記録デイスクと記録情報
検出用光ビームの光軸との直交関係のずれを検出
してこのずれに応じて前記光軸の傾斜をなす傾斜
手段を制御して前記直交関係を維持するようにし
たサーボ系を有する記録情報再生装置であつて、
前記直交関係を検出する手段は、発射光を前記デ
イスクへ向けて照射する発光素子と、この発射光
の前記デイスクによる反射光を受光する受光手段
とからなり、前記デイスク上における前記発射光
のビーム半径を前記デイスクのリードイン及びリ
ードアウトトラツク部分の半径方向の長さの少な
いほうの長さより小に設定してなることを特徴と
する。 The recorded information reproducing apparatus according to the present invention includes a tilting means that detects a deviation in the orthogonal relationship between the recording disk and the optical axis of the recorded information detection light beam in at least the program portion, and tilts the optical axis in accordance with this deviation. A recorded information reproducing device having a servo system controlled to maintain the orthogonal relationship,
The means for detecting the orthogonal relationship includes a light emitting element that irradiates the emitted light toward the disk, and a light receiving means that receives the reflected light of the emitted light by the disk, and the means for detecting the orthogonal relationship includes It is characterized in that the radius is set smaller than the smaller radial length of the lead-in and lead-out track portions of the disk.

実施例以下に図面を用いて本考案の実施例を説明す
る。Examples Examples of the present invention will be described below with reference to the drawings.

第１図は本考案の１実施例を示すもので、図に
おいて、ピツクアツプ１上に、デイスク２と記録
情報検出用光ビーム（図示せず）の光軸との間の
直交関係を検出するための発射光を発する発光素
子３と、この素子３の両サイドに設置された受光
素子４，５とがあり、発光素子３の発射光のデイ
スクによる反射光を素子４，５により受光するの
である。両素子４，５の出力が差動アンプ６へ入
力され、この出力がサーボアンプ７を介してチル
トサーボモータ９の駆動をなす。このモータ９に
よつて、ピツクアツプ１が軸１０を中心に回動し
て図示せぬ情報検出ビームの光軸を傾斜制御す
る。 FIG. 1 shows an embodiment of the present invention. In the figure, a pickup 1 is placed on a pickup 1 for detecting the orthogonal relationship between a disk 2 and an optical axis of a recorded information detection light beam (not shown). There is a light-emitting element 3 that emits light, and light-receiving elements 4 and 5 installed on both sides of this element 3, and the elements 4 and 5 receive the reflected light from the disk of the light emitted by the light-emitting element 3. . The outputs of both elements 4 and 5 are input to a differential amplifier 6, and this output drives a tilt servo motor 9 via a servo amplifier 7. The motor 9 rotates the pickup 1 about a shaft 10 to control the tilt of the optical axis of an information detection beam (not shown).

ここで、何等かの原因によつて、デイスク２が
傾き直交関係がずれると、受光素子４，５の出力
に差異を生じて差動アンプ６の出力は直交関係か
らのずれに応じた信号が得られよつて、これがサ
ーボ信号となつてモータを制御し直交関係を維持
するよう動作する。 Here, if the disk 2 is tilted for some reason and the orthogonal relationship deviates, a difference will occur in the outputs of the light receiving elements 4 and 5, and the output of the differential amplifier 6 will have a signal corresponding to the deviation from the orthogonal relationship. This is then used as a servo signal to control the motor and operate to maintain the orthogonal relationship.

ここで、記録デイスクの規格によれば、デイス
ク２の外周にはプログラム部分２１の終了点から
更に外周に半径約１ミリの間はリードアウトトラ
ツク部分２３が、またデイスクの内周のプログラ
ム部分２１の開始点から更に内周に半径約1.5ミ
リはリードイントラツク部分２２が夫々設けられ
るようになつている。尚、８はデイスク回転中心
を示している。従つて、デイスクの記録面上にお
ける発光素子３による発射光のビーム半径を１ミ
リよりも小に選定しておけば、図示せぬ記録情報
検出ビーム及び発射光ビームがデイスクの内外周
付近のプログラム部分２１とリードイン又はリー
ドアウトトラツク部分２２，２３との境界にきた
場合でも、発光素子３の発射ビームはデイスクの
ピツトの無い部分にかかることがなく、よつて、
受光素子４，５の間の反射光量に差異は生じな
い。その結果、デイスクの内外周付近の当該境界
でも正確なチルトサーボが可能である。 According to the standards for recording discs, there is a lead-out track part 23 on the outer periphery of the disc 2 for a radius of about 1 mm from the end point of the program part 21, and a lead-out track part 23 on the inner periphery of the disc. Further, a lead intratrack portion 22 is provided at a radius of approximately 1.5 mm on the inner periphery from the starting point. Note that 8 indicates the center of disk rotation. Therefore, if the beam radius of the light emitted by the light emitting element 3 on the recording surface of the disk is selected to be smaller than 1 mm, the recorded information detection beam and the emitted light beam (not shown) will be able to detect the program near the inner and outer peripheries of the disk. Even when reaching the boundary between the portion 21 and the lead-in or lead-out track portions 22, 23, the emitted beam of the light emitting element 3 will not hit the pit-free portion of the disk, and therefore,
There is no difference in the amount of reflected light between the light receiving elements 4 and 5. As a result, accurate tilt servo is possible even at the boundaries near the inner and outer peripheries of the disk.

そして、この傾斜検出ビームを平行光束とすれ
ばデイスクの上下位置によつて生ずる検出誤差や
検出感度の低下を除去できることになる。 If this tilted detection beam is made into a parallel light beam, detection errors and decreases in detection sensitivity caused by the upper and lower positions of the disk can be eliminated.

第２図は本考案の他の実施例を示す図であり、
第１図と同等部分は同一符号により示している。
Ａは側面図であり、ＢはそのＡ−A′断面図であ
る。本例では、トラツク接線方向若しくはそれに
直交する方向に発光素子３を傾斜して配置すれ
ば、反射光の大部分は受光素子４，５の受光面へ
入射するので、効率良く誤差なくチルトサーボ信
号を得ることができる。受光素子４，５は発光素
子３の傾斜方向に沿つて長い構造とすれば、デイ
スクの上下位置の変動による誤差を除去し得るこ
とになる。 FIG. 2 is a diagram showing another embodiment of the present invention,
Components equivalent to those in FIG. 1 are designated by the same reference numerals.
A is a side view, and B is a sectional view taken along line A-A'. In this example, if the light emitting element 3 is arranged tilted in the track tangential direction or in the direction perpendicular thereto, most of the reflected light will be incident on the light receiving surfaces of the light receiving elements 4 and 5, so that the tilt servo signal can be efficiently and without error. Obtainable. If the light-receiving elements 4 and 5 have a long structure along the inclination direction of the light-emitting element 3, errors caused by fluctuations in the vertical position of the disk can be eliminated.

効果このように本考案によれば、傾斜検出光ビーム
のデイスク上におけるビーム半径をリードイン、
リードアウトトラツク部分の半径方向の長さより
も小に設定したので、デイスク内外周付近のプロ
グラム部分とリードイン又はリードアウトトラツ
ク部分との境界においても傾斜検出光ビームがピ
ツトからはずれることがなく、正確なチルトサー
ボがなされることになる。Effects As described above, according to the present invention, the beam radius on the disk of the tilt detection light beam can be set as the lead-in,
Since it is set to be smaller than the length in the radial direction of the lead-out track section, the tilt detection light beam will not deviate from the pit even at the boundary between the program section near the inner and outer periphery of the disk and the lead-in or lead-out track section, ensuring accurate detection. A tilt servo will be used.

[Brief explanation of the drawing]

第１図は本考案の実施例を示す図、第２図は本
考案の他の実施例を示す図であり、Ａはその側面
図、ＢはそのＡ−A′断面図である。主要部分の符号の説明、２……デイスク、３…
…発光素子、４，５……受光素子、９……モー
タ。 FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing another embodiment of the present invention, where A is a side view thereof and B is a sectional view taken along line A-A'. Explanation of symbols of main parts, 2...disk, 3...
...Light emitting element, 4, 5... Light receiving element, 9... Motor.

Claims

[Scope of utility model registration request]

Detecting a deviation in the orthogonal relationship between the recording disk and the optical axis of the recorded information detection light beam in at least the program portion, and controlling a tilting means for tilting the optical axis in accordance with this deviation to maintain the orthogonal relationship. In the recorded information reproducing apparatus having a servo system, the means for detecting the orthogonal relationship includes a light emitting element that emits emitted light toward the disk, and a light emitting element that receives reflected light of the emitted light from the disk. and a light receiving means, and the beam radius of the emitted light on the disk is set to be smaller than the smaller length in the radial direction of the lead-in and lead-out track portions of the disk. Device.