JP2010146640A - Light shielding filter and optical head device - Google Patents

Light shielding filter and optical head device Download PDF

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JP2010146640A
JP2010146640A JP2008323044A JP2008323044A JP2010146640A JP 2010146640 A JP2010146640 A JP 2010146640A JP 2008323044 A JP2008323044 A JP 2008323044A JP 2008323044 A JP2008323044 A JP 2008323044A JP 2010146640 A JP2010146640 A JP 2010146640A
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light
light shielding
laser light
shielding filter
filter
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JP5062159B2 (en
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Hiroyuki Suyama
洋行 須山
Takanari Toyama
隆也 外山
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Pulstec Industrial Co Ltd
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Pulstec Industrial Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To reduce the influence of a laser beam reflected at a light shielding area in a light shielding filter for turning the laser beam to an annular beam. <P>SOLUTION: The light shielding filter 10 comprises a transparent substrate 11 made of a disc-shaped transparent glass plate, and a hemispherical light shielding member 12 adhered to the center part of the transparent substrate 11. The light shielding member 12 is formed by coating a light shielding material 13 on the surface of a semicircular object. The light shielding member 12 forms a light shielding area 15 and forms an annular light-transmitting area 16 on the periphery of the light shielding area 15. Since the incident face of a laser beam in the light shielding area 15 does not have a plane orthogonal to the optical axis of the laser beam, the laser beam reflected at the light shielding area 15 is prevented from being made incident on a laser beam source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、透過したレーザ光が輪帯光となるように遮光域と透光域とを備えた遮光フィルタ、および、その遮光フィルタを備えた光ヘッド装置に関する。   The present invention relates to a light-shielding filter having a light-shielding area and a light-transmitting area so that transmitted laser light becomes annular light, and an optical head device having the light-shielding filter.

従来から、加工対象物に集光したレーザ光を照射して加工を行うレーザ加工装置や、光ディスクに集光したレーザ光を照射して光ディスクにデータを記録したり光ディスクに記録されたデータを再生したりする光ディスク装置はよく知られている。このようなレーザ光を使用した装置においては、微細な加工を実現するため、あるいは、データの集積度を上げるために、集光したレーザ光により形成される光スポット径がより微小にされる傾向にある。   Conventionally, a laser processing device that performs processing by irradiating a focused laser beam on a workpiece, or records data on an optical disc by irradiating the focused laser beam on an optical disc, or reproduces data recorded on an optical disc Such optical disk devices are well known. In an apparatus using such a laser beam, the diameter of the light spot formed by the focused laser beam tends to be smaller in order to realize fine processing or increase the degree of data integration. It is in.

光スポット径を微小にする方法としては、レーザ光の波長を短くすることや、レーザ光を集光するレンズの開口数（ＮＡ）を大きくすることが一般的であるが、これ以外にもレーザ光を輪帯光（断面がリング状のビーム）にする方法が知られている。例えば、特許文献１に提案されたレーザ加工装置においては、レーザ光を輪帯光にする超解像光学素子を設けて光スポット径を微小化している。この特許文献１には、レーザ光を輪帯光にする方法として、２つのアキシコンレンズを対向させる方法と、ドーナツ状の遮光フィルタを用いる方法が提案されている。
特開２００７−２１６２６３号公報 As a method for reducing the light spot diameter, it is common to shorten the wavelength of the laser beam or increase the numerical aperture (NA) of the lens that collects the laser beam. There is known a method of turning light into annular light (a beam having a ring-shaped cross section). For example, in the laser processing apparatus proposed in Patent Document 1, a super-resolution optical element that converts laser light into ring light is provided to reduce the light spot diameter. Patent Document 1 proposes a method of making two axicon lenses face each other and a method of using a donut-shaped light shielding filter as methods for converting laser light into annular light.
JP 2007-216263 A

２つのアキシコンレンズを対向させる方法は、アキシコンレンズの設置位置精度が悪いと形状の良い輪帯光が得られない。このため、設置位置調整に時間がかかってしまうという問題がある。一方、ドーナツ状の遮光フィルタを用いる方法は、設置位置調整が容易である。しかし、遮光フィルタの遮光域で反射したレーザ光の影響が現れる。遮光フィルタは、透明平板の中央部に遮光材を蒸着させて遮光域を形成し、遮光部の周囲を輪帯状の透光域としたものである。こうした遮光フィルタは、レーザ光の光路途中に設けられて使用されるが、遮光域で反射したレーザ光がレーザ光源に入射してレーザ光の光量制御の精度が落ちたり、レーザ光源の劣化を早めたりするといった問題が生じる。また、遮光域で反射したレーザ光がフォトディテクタに入射する場合もあり、フォーカス制御やトラッキング制御といったレーザ光の反射光に基づく制御に悪影響を与えてしまうおそれもある。   In the method of making the two axicon lenses face each other, the annular light having a good shape cannot be obtained if the installation position accuracy of the axicon lens is poor. For this reason, there exists a problem that installation position adjustment will take time. On the other hand, the method using a donut-shaped light shielding filter is easy to adjust the installation position. However, the influence of the laser beam reflected in the light shielding area of the light shielding filter appears. The light shielding filter is formed by depositing a light shielding material at the center of a transparent flat plate to form a light shielding area, and surrounding the light shielding part with a ring-shaped light transmitting area. Such a light-shielding filter is used in the middle of the optical path of the laser light, but the laser light reflected from the light-shielding area is incident on the laser light source and the accuracy of laser light quantity control is reduced, or the laser light source is accelerated. Problems occur. In addition, the laser light reflected in the light shielding area may enter the photodetector, which may adversely affect the control based on the reflected light of the laser light, such as focus control and tracking control.

本発明は、上記問題に対処するためになされたもので、レーザ光を輪帯光にする遮光フィルタにおいて、遮光域で反射したレーザ光の影響を低減することを目的とする。   The present invention has been made to cope with the above problem, and an object of the present invention is to reduce the influence of laser light reflected in a light shielding area in a light shielding filter that converts laser light into ring light.

上記目的を達成するために、本発明の遮光フィルタの特徴は、レーザ光が入射する領域の中央部に遮光域を、その遮光域の周囲に輪帯状の透光域を備えて、入射したレーザ光を輪帯光にして透過する遮光フィルタにおいて、前記遮光域は、レーザ光の入射面が前記レーザ光の光軸に対して直交する平面を有さないように形成されたことにある。   In order to achieve the above object, the light blocking filter of the present invention is characterized in that an incident laser having a light blocking area at the center of an area where laser light is incident and an annular light transmitting area around the light blocking area. In the light-shielding filter that transmits light as annular light, the light-shielding area is formed so that the incident surface of the laser light does not have a plane orthogonal to the optical axis of the laser light.

本発明によれば、遮光域におけるレーザ光の入射面がレーザ光の光軸に対して直交する平面を有していないため、遮光域に入射したレーザ光は、その入射方向とは異なる方向に反射する。このため、遮光域で反射したレーザ光がレーザ光源に入射しないようにすることができる。尚、透光域については、レーザ光の光軸に対して直交する平板状に形成されることが好ましいが、レーザ光が進行方向を変えずに透過できるものであれば任意の形状にて実施できる。   According to the present invention, since the incident surface of the laser light in the light shielding area does not have a plane perpendicular to the optical axis of the laser light, the laser light incident on the light shielding area is in a direction different from the incident direction. reflect. For this reason, it is possible to prevent the laser light reflected in the light shielding area from entering the laser light source. The translucent region is preferably formed in a flat plate shape that is orthogonal to the optical axis of the laser beam, but any shape can be used as long as the laser beam can be transmitted without changing the traveling direction. it can.

また、本発明の遮光フィルタの他の特徴は、前記遮光域は、半球形状、円錐形状、角錐形状の何れかの形状に形成されていることにある。本発明によれば、遮光域に入射したレーザ光を様々な方向に反射させることができるので、特定方向に片寄ってレーザ光が反射することがない。このため、レーザ光の光路上に設けた他の光学素子に対して反射光の影響を抑制することができる。尚、半球形状とは、球を平面で切断した形状であって、必ずしも二分の一に切断した形状に限るものではない。   In addition, another feature of the light shielding filter of the present invention is that the light shielding area is formed in any one of a hemispherical shape, a conical shape, and a pyramid shape. According to the present invention, since the laser beam incident on the light shielding area can be reflected in various directions, the laser beam is not reflected in a specific direction. For this reason, the influence of reflected light can be suppressed with respect to other optical elements provided on the optical path of the laser beam. The hemispherical shape is a shape obtained by cutting a sphere in a plane, and is not necessarily limited to a shape cut in half.

また、本発明の遮光フィルタの他の特徴は、遮光材料をコーティングした遮光体を、透明平板の中央部に接着して構成されることにある。この場合、前記遮光体は、半球形状、円錐形状、角錐形状の何れかの形状に形成されているとよい。本発明によれば、遮光材料をコーティングした遮光体を透明平板の中央部に接着することで、透明平板の中央部に遮光域が形成され、その周囲に輪帯状の透光域が形成される。従って、遮光フィルタを簡単に製造することができる。   Another feature of the light-shielding filter of the present invention is that a light-shielding body coated with a light-shielding material is bonded to the central portion of the transparent flat plate. In this case, the light shielding body may be formed in any one of a hemispherical shape, a conical shape, and a pyramid shape. According to the present invention, a light-shielding body coated with a light-shielding material is adhered to the central portion of the transparent flat plate, thereby forming a light-shielding region at the central portion of the transparent flat plate, and forming an annular light-transmitting region around it. . Therefore, the light shielding filter can be easily manufactured.

また、本発明の遮光フィルタの他の特徴は、前記レーザ光の光軸を中心軸にした筒体内に取り付けられたことにある。本発明によれば、遮光域で反射したレーザ光は、筒体で遮られるため他の光学素子に入射しにくく、遮光フィルタからの反射光が外乱光となって、例えば、レーザ光の光量制御やフォーカス制御といった制御系に悪影響を及ぼすという不具合を防止することができる。   Another feature of the light-shielding filter according to the present invention is that the light-shielding filter is attached to a cylindrical body having the optical axis of the laser light as a central axis. According to the present invention, the laser light reflected in the light shielding area is shielded by the cylindrical body, so that it is difficult to enter the other optical elements, and the reflected light from the light shielding filter becomes disturbance light, for example, control of the amount of laser light. It is possible to prevent the problem of adversely affecting the control system such as focus control.

また、本発明の光ヘッド装置の特徴は、レーザ光を出射するレーザ光源と、前記出射されたレーザ光を平行光にするコリメーティングレンズと、前記平行光にされたレーザ光を集光する対物レンズとを少なくとも備える光ヘッド装置において、前記レーザ光源から前記対物レンズまでの光路上に遮光フィルタを設置したことにある。   Further, the optical head device of the present invention is characterized in that a laser light source that emits laser light, a collimating lens that makes the emitted laser light parallel light, and the laser light that has been made parallel light is condensed. In an optical head device including at least an objective lens, a light shielding filter is provided on an optical path from the laser light source to the objective lens.

本発明によれば、遮光域で反射したレーザ光がレーザ光源に入射しないようにすることができる。従って、レーザ光のスポット径を微小にして照射する光ヘッド装置として使用すると非常に有益である。   According to the present invention, it is possible to prevent the laser light reflected in the light shielding area from entering the laser light source. Therefore, it is very useful when used as an optical head device that irradiates with a laser beam having a small spot diameter.

本発明の光ヘッド装置の他の特徴は、前記筒体は、その側面を覆う熱伝達用部材を介して光ヘッドケーシングに熱伝達可能に取り付けされていることにある。遮光域で反射したレーザ光を筒体で遮ると筒体が発熱する。そこで、本発明においては、筒体を、その側面を覆う熱伝達用部材を介して光ヘッドケーシング（光ヘッド装置のケーシング）に熱伝達可能に取り付けているため、筒体で発生した熱を光ヘッドケーシングにスムーズに移動させることができる。この結果、筒体が熱膨張して遮光フィルタの位置ずれが発生するといった不具合を防止することができる。   Another feature of the optical head device of the present invention resides in that the cylindrical body is attached to the optical head casing so as to be capable of transferring heat through a heat transfer member covering the side surface. When the laser beam reflected by the light shielding area is blocked by the cylinder, the cylinder generates heat. Therefore, in the present invention, the cylindrical body is attached to the optical head casing (the casing of the optical head device) through a heat transfer member that covers the side surface of the cylindrical body so that heat can be transferred. It can be smoothly moved to the head casing. As a result, it is possible to prevent a problem that the cylindrical body is thermally expanded and the light-shielding filter is displaced.

以下、本発明の一実施形態について図面を用いて説明する。図１は、実施形態に係る遮光フィルタ１０を表し、（ａ）は遮光フィルタ１０の斜視図、（ｂ）は遮光フィルタ１０の横断面図、（ｃ）は遮光フィルタの正面図である。遮光フィルタ１０は、円盤状の透明ガラス平板からなる透明基板１１と、透明基板１１の中央部に接着される半円球状の遮光部材１２とから構成される。遮光部材１２は、半球形状物体の表面（底面は除いてよい）に遮光材料１３をコーティングして形成される。そして、遮光部材１２の底面（球体の切断面）を透明基板１１の中心に接着することで遮光フィルタ１０が完成する。この場合、透明基板１１の中心と遮光部材１２の底面の中心とを一致させて、透明基板１１と遮光部材１２とを同心状に接着する。   Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B show a light shielding filter 10 according to an embodiment, in which FIG. 1A is a perspective view of the light shielding filter 10, FIG. 1B is a cross-sectional view of the light shielding filter 10, and FIG. The light shielding filter 10 includes a transparent substrate 11 made of a disk-shaped transparent glass flat plate, and a hemispherical light shielding member 12 bonded to the central portion of the transparent substrate 11. The light shielding member 12 is formed by coating a light shielding material 13 on the surface (a bottom surface may be excluded) of a hemispherical object. Then, the light shielding filter 10 is completed by bonding the bottom surface of the light shielding member 12 (the cut surface of the sphere) to the center of the transparent substrate 11. In this case, the center of the transparent substrate 11 and the center of the bottom surface of the light shielding member 12 are aligned, and the transparent substrate 11 and the light shielding member 12 are bonded concentrically.

例えば、半球形状のガラス体の表面をクロムコートして遮光部材１２を作成し、この遮光部材１２を透明基板１１の中心に接着剤で接着することで、簡単に遮光フィルタ１０を製造することができる。この場合には、コーティング処理時のマスクが不要となり製造コストを低く抑えることができる。   For example, the light shielding filter 10 can be easily manufactured by forming the light shielding member 12 by chromium coating the surface of the hemispherical glass body and bonding the light shielding member 12 to the center of the transparent substrate 11 with an adhesive. it can. In this case, a mask for the coating process is not necessary, and the manufacturing cost can be reduced.

このように形成された遮光フィルタ１０は、レーザ光の光路中に設けられるが、レーザ光の光軸が遮光フィルタ１０の中心（透明基板１１の中心でもあり遮光部材１２の中心でもある）を通るように、かつ、レーザ光の光軸に対して透明基板１１の表面が垂直となるように配置されるものである。また、遮光部材１２を設けた側の面がレーザ光の入射する面となるようにする。従って、遮光部材１２がレーザ光を遮光する遮光域１５となり、透明基板１１における遮光部材１２との接着部の周囲がレーザ光を透過する透光域１６となる。遮光域１５は、レーザ光の入射側から見て円形に形成され、透光域１６は、レーザ光の入射側から見て輪帯状（リング状）に形成される。   The light shielding filter 10 formed in this way is provided in the optical path of the laser light, and the optical axis of the laser light passes through the center of the light shielding filter 10 (the center of the transparent substrate 11 and the center of the light shielding member 12). Thus, the transparent substrate 11 is arranged so that the surface thereof is perpendicular to the optical axis of the laser beam. Further, the surface on which the light shielding member 12 is provided is made to be a surface on which laser light is incident. Accordingly, the light shielding member 12 becomes a light shielding area 15 where the laser light is shielded, and the periphery of the bonding portion of the transparent substrate 11 with the light shielding member 12 becomes a light transmitting area 16 where the laser light is transmitted. The light shielding area 15 is formed in a circular shape when viewed from the laser light incident side, and the light transmitting area 16 is formed in an annular shape (ring shape) as viewed from the laser light incident side.

遮光フィルタ１０に入射したレーザ光は、遮光域１５にて中央部が遮られ透光域１６のみを透過するため、輪帯光となって遮光フィルタ１０から出射する。遮光域１５に入射したレーザ光は、所定の割合で反射するが、遮光域１５におけるレーザ光の入射面がレーザ光の光軸と直交する平面を有さないため、入射してきた方向には殆ど反射しない。   The laser light incident on the light blocking filter 10 is emitted from the light blocking filter 10 as annular light because the central portion is blocked by the light blocking region 15 and passes only through the light transmitting region 16. The laser light incident on the light shielding area 15 is reflected at a predetermined ratio, but the incident surface of the laser light in the light shielding area 15 does not have a plane perpendicular to the optical axis of the laser light, so that it is almost in the incident direction. Does not reflect.

次に、遮光フィルタ１０を備えた光ヘッド装置について説明する。図２は、実施形態としての光ヘッド装置１の概略構成図である。光ヘッド装置１は、例えば、光ディスクにデータを記録したり光ディスクのデータを再生したりする光ディスク装置や、加工対象物をレーザ加工するレーザ加工装置に用いられる。   Next, an optical head device including the light shielding filter 10 will be described. FIG. 2 is a schematic configuration diagram of an optical head device 1 as an embodiment. The optical head device 1 is used in, for example, an optical disc device that records data on an optical disc or reproduces data on the optical disc, and a laser processing device that lasers a workpiece.

光ヘッド装置１は、レーザ光源５０，コリメーティングレンズ５２，立ち上げミラー５４，偏光ビームスプリッタ５６，集光レンズ５８，フォトディテクタ６０，１／４波長板６２，光強度変換素子６４，遮光フィルタ１０，対物レンズ６８，対物レンズホルダ７０，集光レンズ７２，シリンドリカルレンズ７４，フォトディテクタ７６等を光ヘッドケーシング７８内に収納して構成される。レーザ光は、レーザ光源５０から出射し、コリメーティングレンズ５２を透過して平行光となり立ち上げミラー５４に入射する。立ち上げミラー５４に入射したレーザ光は、進行方向を変え偏光ビームスプリッタ５６に入射し、偏光ビームスプリッタ５６で大部分（例えば全体の９５％）が透過し、少量（例えば全体の５％）が反射する。偏光ビームスプリッタ５６で反射したレーザ光は、集光レンズ５８を介してフォトディテクタ６０に入射する。フォトディテクタ６０は、受光光量に相当する強度の信号を出力する。この信号は、レーザ光源５０の出射光量を一定に保つ光量制御に使われる。   The optical head device 1 includes a laser light source 50, a collimating lens 52, a rising mirror 54, a polarization beam splitter 56, a condensing lens 58, a photodetector 60, a quarter wavelength plate 62, a light intensity conversion element 64, and a light shielding filter 10. , The objective lens 68, the objective lens holder 70, the condenser lens 72, the cylindrical lens 74, the photodetector 76, and the like are housed in an optical head casing 78. The laser light is emitted from the laser light source 50, passes through the collimating lens 52, becomes parallel light, and enters the rising mirror 54. The laser light incident on the rising mirror 54 changes its traveling direction and is incident on the polarization beam splitter 56, and most (for example, 95% of the total) is transmitted through the polarization beam splitter 56 and a small amount (for example, 5% of the total) is transmitted. reflect. The laser beam reflected by the polarization beam splitter 56 enters the photodetector 60 via the condenser lens 58. The photodetector 60 outputs a signal having an intensity corresponding to the amount of received light. This signal is used for light quantity control for keeping the light quantity emitted from the laser light source 50 constant.

偏光ビームスプリッタ５６を透過したレーザ光は、１／４波長板６２を透過して直線偏光から円偏光に変化して光強度変換素子６４に入射する。光強度変換素子６４は、例えば、特開２００２−２６７８１０にて知られているように、ガウス型光強度分布をもつ入射光を、中央部の光強度が低く、かつ、周辺部の光強度が高い光強度分布をもつ出射光に変換する素子である。光強度変換素子６４に入射するレーザ光は、レーザ光の光軸に垂直な断面で見てガウス分布の光強度分布になっているが、光強度変換素子６４を透過することで、周辺が中心部より強度が高い光強度分布となる。   The laser light that has passed through the polarization beam splitter 56 passes through the quarter-wave plate 62, changes from linearly polarized light to circularly polarized light, and enters the light intensity conversion element 64. For example, as is known in Japanese Patent Application Laid-Open No. 2002-267810, the light intensity conversion element 64 converts incident light having a Gaussian light intensity distribution with a low light intensity at the central part and a light intensity at the peripheral part. It is an element that converts it into outgoing light having a high light intensity distribution. The laser light incident on the light intensity conversion element 64 has a Gaussian light intensity distribution as viewed in a cross section perpendicular to the optical axis of the laser light. However, by passing through the light intensity conversion element 64, the periphery is centered. The light intensity distribution is higher than that of the portion.

光強度変換素子６４を透過したレーザ光は、上述した遮光フィルタ１０を透過することで輪帯光となる。この場合、光強度変換素子６４によりレーザ光の強度分布が中心部より周辺部の強度が高くなるように変換されているため、遮光フィルタ１０の中心部（遮光域１５）で損失する光量を減らすことができる。遮光フィルタ１０に入射したレーザ光は、遮光域１５である程度の量が反射するが、遮光部材１２が半球形状に形成されているため、その反射光は様々な方向に進む。従って、レーザ光源５０に入射する反射光が極微少量となり、レーザ光源５０の劣化を早めることがなくなる。また、光ディスクへのデータ記録やレーザ加工の時などのようにレーザ光の強度が大きくても、レーザ光の光量制御の精度が低下しない。   The laser light that has passed through the light intensity conversion element 64 passes through the light shielding filter 10 described above, and becomes annular light. In this case, since the intensity distribution of the laser light is converted by the light intensity conversion element 64 so that the intensity at the peripheral part is higher than that at the central part, the amount of light lost at the central part (the light shielding area 15) of the light shielding filter 10 is reduced. be able to. A certain amount of the laser light incident on the light shielding filter 10 is reflected by the light shielding area 15, but the reflected light travels in various directions because the light shielding member 12 is formed in a hemispherical shape. Accordingly, the amount of reflected light incident on the laser light source 50 becomes extremely small, and the deterioration of the laser light source 50 is not accelerated. Further, even when the intensity of the laser beam is high, such as when recording data on an optical disk or during laser processing, the accuracy of the light amount control of the laser beam does not decrease.

遮光フィルタ１０を透過して輪帯光となったレーザ光は、対物レンズ６８により照射対象物ＯＢに集光し、照射対象物ＯＢ上に微小な光スポットを形成する。対物レンズ６８と遮光フィルタ１０は、対物レンズホルダ７０内に固定される。対物レンズホルダ７０は、光を透過しない円筒体であり、その中心軸（円筒中心軸）がレーザ光の光軸と一致するように配置される。また、対物レンズ６８と遮光フィルタ１０は、それらの中心軸が対物レンズホルダ７０の円筒軸と一致するように固定される。   The laser light that has passed through the light shielding filter 10 and has become annular light is condensed on the irradiation object OB by the objective lens 68 to form a minute light spot on the irradiation object OB. The objective lens 68 and the light shielding filter 10 are fixed in the objective lens holder 70. The objective lens holder 70 is a cylindrical body that does not transmit light, and is arranged such that its central axis (cylindrical central axis) coincides with the optical axis of the laser light. The objective lens 68 and the light shielding filter 10 are fixed so that their central axes coincide with the cylindrical axis of the objective lens holder 70.

照射対象物ＯＢで反射したレーザ光は、対物レンズ６８で平行光に戻り、遮光フィルタ１０を透過した後、光強度変換素子６４および１／４波長板６２を透過する。１／４波長板６２を透過したレーザ光は、偏光方向が出射時とは９０度異なる直線偏光となり偏光ビームスプリッタ５６に入射する。偏光ビームスプリッタ５６に入射したレーザ光は、大部分（例えば全体の９５％程度）が反射し、集光レンズ７２，シリンドリカルレンズ７４を介してフォトディテクタ７６に入射する。フォトディテクタ７６は、受光領域が複数に分割され、各分割領域ごとに受光光量に相当する強度の信号を出力する。この信号は、レーザ光の集光位置を照射対象物ＯＢの表面またはデータ記録面に一致させるためのフォーカスサーボや、レーザ光の集光位置を照射対象物ＯＢに形成されたトラックに一致させるためのトラッキングサーボに使用される。また、照射対象物ＯＢがデータの記録された光ディスクであれば、記録されたデータの再生に使用される。尚、図中においては、フォーカスサーボやトラッキングサーボを行うためのアクチュエータを省略している。   The laser light reflected by the irradiation object OB returns to parallel light by the objective lens 68, passes through the light shielding filter 10, and then passes through the light intensity conversion element 64 and the quarter wavelength plate 62. The laser light transmitted through the quarter-wave plate 62 becomes linearly polarized light whose polarization direction is 90 degrees different from that at the time of emission, and enters the polarization beam splitter 56. Most of the laser light incident on the polarization beam splitter 56 is reflected (for example, about 95% of the whole) and enters the photodetector 76 via the condenser lens 72 and the cylindrical lens 74. The photodetector 76 divides the light receiving area into a plurality of parts, and outputs a signal having an intensity corresponding to the amount of received light for each divided area. This signal is used to make the focus position of the laser beam coincide with the surface of the irradiation object OB or the data recording surface, or to match the laser beam condensing position with the track formed on the irradiation object OB. Used for tracking servo. Further, if the irradiation object OB is an optical disc on which data is recorded, it is used for reproducing the recorded data. In the figure, an actuator for performing focus servo and tracking servo is omitted.

フォトディテクタ６０，７６は、本来のレーザ光や反射光のみが入射することが望まれるが、遮光フィルタ１０の遮光域１５で反射したレーザ光が外乱光となって入射する可能性がある。特に、レーザ光源５０から出射するレーザ光の強度が大きいときは、フォトディテクタ６０，７６に入射する外乱光の強度が大きくなり、フォーカスサーボやトラッキングサーボの精度が悪化する可能性がある。そこで、本実施形態においては、対物レンズホルダ７０内に遮光フィルタ１０を設けることにより、遮光フィルタ１０の遮光域１５で反射したレーザ光を対物レンズホルダ７０の内筒面にて遮蔽するようにしている。つまり、遮光域１５で反射したレーザ光を対物レンズホルダ７０の外に出ないようにしている。この場合、遮光フィルタ１０の取付位置よりもレーザ光の入射側に対物レンズホルダ７０の円筒壁面を長くすることで、遮光域１５で反射したレーザ光の遮蔽度合いを高めることができる。この結果、遮光域１５で反射したレーザ光の殆どは、フォトディテクタ６０，７６に外乱光として入射しないようになる。従って、レーザ光の光量や照射対象物ＯＢからの反射光の光量に基づいて行う各種の制御を精度良く行うことができる。   Although it is desirable that the photodetectors 60 and 76 receive only original laser light or reflected light, the laser light reflected by the light shielding region 15 of the light shielding filter 10 may be incident as disturbance light. In particular, when the intensity of the laser light emitted from the laser light source 50 is large, the intensity of disturbance light incident on the photodetectors 60 and 76 may increase, and the accuracy of the focus servo and tracking servo may deteriorate. Therefore, in the present embodiment, by providing the light shielding filter 10 in the objective lens holder 70, the laser light reflected by the light shielding area 15 of the light shielding filter 10 is shielded by the inner cylindrical surface of the objective lens holder 70. Yes. That is, the laser light reflected by the light shielding area 15 is prevented from coming out of the objective lens holder 70. In this case, by making the cylindrical wall surface of the objective lens holder 70 longer on the laser light incident side than the attachment position of the light shielding filter 10, the degree of shielding of the laser light reflected by the light shielding region 15 can be increased. As a result, most of the laser light reflected by the light shielding area 15 does not enter the photodetectors 60 and 76 as disturbance light. Therefore, various controls performed based on the amount of laser light and the amount of reflected light from the irradiation object OB can be accurately performed.

次に、遮光フィルタの変形例について説明する。図３は、第１変形例に係る遮光フィルタ２０を表し、（ａ）は遮光フィルタ２０の斜視図、（ｂ）は遮光フィルタ２０の平面図、（ｃ）は遮光フィルタ２０の正面図である。第１変形例の遮光フィルタ２０は、上述した実施形態の遮光部材１２に代えて、円錐形状の遮光部材２２を設けたものである。この遮光部材２２は、円錐形状物体の表面（底面は除いてよい）に遮光材料１３をコーティングして形成され、実施形態の遮光部材１２と同様に、透明基板１１の中心に接着される。従って、遮光部材２２がレーザ光を遮光する遮光域２５となり、透明基板１１における遮光部材２２との接着部の周囲がレーザ光を透過する透光域２６となる。例えば、円錐形状のガラス体の表面をクロムコートして遮光部材２２を作成し、この遮光部材２２を透明基板１１の中心に接着剤で接着することで、簡単に遮光フィルタ２０を製造することができる。   Next, a modified example of the light shielding filter will be described. 3A and 3B show a light shielding filter 20 according to a first modification, in which FIG. 3A is a perspective view of the light shielding filter 20, FIG. 3B is a plan view of the light shielding filter 20, and FIG. . The light shielding filter 20 of the first modification is provided with a conical light shielding member 22 instead of the light shielding member 12 of the above-described embodiment. The light shielding member 22 is formed by coating the surface of the conical object (except for the bottom surface) with the light shielding material 13, and is adhered to the center of the transparent substrate 11 in the same manner as the light shielding member 12 of the embodiment. Therefore, the light shielding member 22 becomes a light shielding area 25 where the laser light is shielded, and the periphery of the bonding portion of the transparent substrate 11 with the light shielding member 22 becomes a light transmitting area 26 where the laser light is transmitted. For example, the light shielding filter 20 can be easily manufactured by making the light shielding member 22 by chromium-coating the surface of a conical glass body and bonding the light shielding member 22 to the center of the transparent substrate 11 with an adhesive. it can.

この第１変形例の遮光フィルタ２０においても、実施形態と同様に、遮光域２５に入射したレーザ光は、遮光域２５におけるレーザ光の入射面がレーザ光の光軸と直交する平面を有さないため、入射してきた方向には殆ど反射しない。従って、実施形態と同様の作用効果を得ることができる。   Also in the light shielding filter 20 of the first modified example, the laser light incident on the light shielding area 25 has a plane in which the incident surface of the laser light in the light shielding area 25 is orthogonal to the optical axis of the laser light, as in the embodiment. Therefore, it hardly reflects in the incident direction. Therefore, the same effect as the embodiment can be obtained.

次に、遮光フィルタの第２変形例について説明する。図４は、第２変形例に係る遮光フィルタ３０を表し、（ａ）は遮光フィルタ３０の斜視図、（ｂ）は遮光フィルタ３０の平面図、（ｃ）は遮光フィルタ３０の正面図である。第２変形例の遮光フィルタ３０は、実施形態の遮光部材１２に代えて、角錐形状（この例では八角錐）の遮光部材３２を設けたものである。この遮光部材３２は、角錐形状物体の表面（底面は除いてよい）に遮光材料１３をコーティングして形成され、実施形態の遮光部材１２と同様に、透明基板１１の中心に接着される。従って、遮光部材３２がレーザ光を遮光する遮光域３５となり、透明基板１１における遮光部材３２との接着部の周囲がレーザ光を透過する透光域３６となる。例えば、角錐形状のガラス体の表面をクロムコートして遮光部材３２を作成し、この遮光部材２２を透明基板１１の中心に接着剤で接着することで、簡単に遮光フィルタ３０を製造することができる。   Next, a second modification of the light shielding filter will be described. 4A and 4B show a light shielding filter 30 according to a second modification, in which FIG. 4A is a perspective view of the light shielding filter 30, FIG. 4B is a plan view of the light shielding filter 30, and FIG. 4C is a front view of the light shielding filter 30. . The light shielding filter 30 of the second modified example is provided with a light shielding member 32 having a pyramid shape (an octagonal pyramid in this example) instead of the light shielding member 12 of the embodiment. The light shielding member 32 is formed by coating the surface of the pyramid-shaped object (except for the bottom surface) with the light shielding material 13, and is bonded to the center of the transparent substrate 11 in the same manner as the light shielding member 12 of the embodiment. Therefore, the light shielding member 32 becomes a light shielding region 35 that shields the laser light, and the periphery of the bonding portion of the transparent substrate 11 with the light shielding member 32 becomes a light transmitting region 36 that transmits the laser light. For example, the light shielding filter 30 can be easily manufactured by making the light shielding member 32 by chromium-coating the surface of a pyramid-shaped glass body and bonding the light shielding member 22 to the center of the transparent substrate 11 with an adhesive. it can.

この第２変形例の遮光フィルタ３０においても、実施形態と同様に、遮光域３５に入射したレーザ光は、遮光域３５におけるレーザ光の入射面がレーザ光の光軸と直交する平面を有さないため、入射してきた方向には殆ど反射しない。従って、実施形態と同様の作用効果を得ることができる。   Also in the light shielding filter 30 of the second modified example, similarly to the embodiment, the laser light incident on the light shielding area 35 has a plane in which the incident surface of the laser light in the light shielding area 35 is orthogonal to the optical axis of the laser light. Therefore, it hardly reflects in the incident direction. Therefore, the same effect as the embodiment can be obtained.

次に、遮光フィルタ１０の配置の変形例について説明する。上述した実施形態においては、遮光フィルタ１０を対物レンズ６８の近傍に配置したが、遮光フィルタ１０は、レーザ光源５０から対物レンズ６８までのレーザ光の光路上であれば様々な位置に配置することができる。例えば、図５に示した光ヘッド装置２のように、コリメーティングレンズ５２と立ち上げミラー５４との間に、光強度変換素子６４と遮光フィルタ１０とを設けるようにしてもよい。この場合、光強度変換素子６４が遮光フィルタ１０に対してレーザ光源５０側となるように配置される。   Next, a modified example of the arrangement of the light shielding filter 10 will be described. In the above-described embodiment, the light shielding filter 10 is disposed in the vicinity of the objective lens 68. However, the light shielding filter 10 is disposed at various positions on the optical path of the laser light from the laser light source 50 to the objective lens 68. Can do. For example, as in the optical head device 2 shown in FIG. 5, the light intensity conversion element 64 and the light shielding filter 10 may be provided between the collimating lens 52 and the rising mirror 54. In this case, the light intensity conversion element 64 is disposed on the laser light source 50 side with respect to the light shielding filter 10.

遮光フィルタ１０は、図６の一部破断斜視図に示すように、フィルタホルダ８０内に固定される。フィルタホルダ８０は、光を透過しない円筒体であり、その円筒軸がレーザ光の光軸と一致するように配置される。フィルタホルダ８０は、立ち上げミラー５４側となる先端に遮光フィルタ１０を円筒軸と同軸状に固定し、遮光フィルタ１０よりレーザ光源５０側に長く延びている。従って、フィルタホルダ８０は、遮光フィルタ１０の遮光域１５で反射したレーザ光の殆どを遮蔽することができる。このため、遮光域１５で反射したレーザ光は、他の素子に外乱光として入射しにくくなる。この例では、フィルタホルダ８０は、遮蔽部の軸方向の寸法（遮光フィルタ１０よりレーザ光源５０側の筒体の軸方向の寸法）を筒体の直径よりも大きくして、縦長の円筒形状に形成されている。   The light shielding filter 10 is fixed in the filter holder 80 as shown in the partially broken perspective view of FIG. The filter holder 80 is a cylindrical body that does not transmit light, and is arranged so that its cylindrical axis coincides with the optical axis of the laser light. The filter holder 80 fixes the light shielding filter 10 coaxially with the cylindrical axis at the tip which becomes the rising mirror 54 side, and extends longer from the light shielding filter 10 to the laser light source 50 side. Therefore, the filter holder 80 can shield most of the laser light reflected by the light shielding area 15 of the light shielding filter 10. For this reason, the laser light reflected by the light shielding area 15 is less likely to be incident as disturbance light on other elements. In this example, the filter holder 80 has a longitudinally long cylindrical shape in which the axial dimension of the shielding portion (the axial dimension of the cylindrical body on the laser light source 50 side from the light shielding filter 10) is larger than the diameter of the cylindrical body. Is formed.

遮光域１５で反射したレーザ光の殆どをフィルタホルダ８０で遮光した場合、フィルタホルダ８０が発熱する。フィルタホルダ８０が発熱すると、遮光フィルタ１０とのあいだに温度差が生じて、遮光フィルタ１０のフィルタホルダ８０に対する取付位置がずれたり、フィルタホルダ８０と光ヘッドケーシング７８とのあいだに温度差が生じて、フィルタホルダ８０の光ヘッドケーシング７８に対する取付位置がずれたりする可能性がある。このような場合には、輪帯光の形状が悪くなる。   When most of the laser light reflected by the light shielding area 15 is shielded by the filter holder 80, the filter holder 80 generates heat. When the filter holder 80 generates heat, a temperature difference is generated between the filter holder 80 and the light-shielding filter 10, and the mounting position of the light-shielding filter 10 with respect to the filter holder 80 is shifted, or a temperature difference is generated between the filter holder 80 and the optical head casing 78. Thus, the mounting position of the filter holder 80 with respect to the optical head casing 78 may be displaced. In such a case, the shape of the annular light becomes worse.

そこで、こうした不具合が生じるおそれがある場合には、図７、図８に示すように、フィルタホルダ８０の円筒壁面を全体にわたって密着して覆う取付具９０を用いて、フィルタホルダ８０を光ヘッドケーシング７８に固定する。この取付具９０は、円筒孔９１が中央に形成された本体部９２と、本体部９２の下部から左右に張り出した脚部９３とからなり、熱伝達率の良い金属等の材料により一体形成される。フィルタホルダ８０は、取付具９０の円筒孔９１に堅く挿入される。従って、フィルタホルダ８０の円筒壁面全体が取付具９０の本体部９２に密着して固定される。また、脚部９３は、ネジ９４により光ヘッドケーシング７８の内壁面に締め付け固定される。従って、取付具９０と光ヘッドケーシング７８との接触面積を広く確保することができる。   Therefore, when there is a possibility that such a problem may occur, as shown in FIGS. 7 and 8, the filter holder 80 is attached to the optical head casing by using an attachment 90 that covers the entire cylindrical wall surface of the filter holder 80 in close contact with each other. Fix to 78. The fixture 90 includes a main body portion 92 having a cylindrical hole 91 formed in the center and leg portions 93 projecting left and right from the lower portion of the main body portion 92, and is integrally formed of a material such as a metal having a good heat transfer coefficient. The The filter holder 80 is firmly inserted into the cylindrical hole 91 of the fixture 90. Therefore, the entire cylindrical wall surface of the filter holder 80 is fixed in close contact with the main body 92 of the fixture 90. The leg portion 93 is fastened and fixed to the inner wall surface of the optical head casing 78 by screws 94. Therefore, a wide contact area between the fixture 90 and the optical head casing 78 can be secured.

これにより、フィルタホルダ８０で発生した熱を取付具９０を介して光ヘッドケーシング７８に良好に移動させることができ、遮光フィルタ１０とフィルタホルダ８０とのあいだの温度差、および、フィルタホルダ８０と光ヘッドケーシング７８との間の温度差を少なくすることができる。この結果、遮光フィルタ１０のフィルタホルダ８０に対する取付位置、および、フィルタホルダ８０の光ヘッドケーシング７８に対する取付位置がずれて輪帯光の形状が悪くなるといった不具合を防止することができる。この取付具９０は、本発明の熱伝達用部材に相当する。尚、光ヘッド装置２に設置する遮光フィルタは、遮光フィルタ１０に限らず、遮光フィルタ２０，３０など他の遮光フィルタを使用することもできる。   Thereby, the heat generated in the filter holder 80 can be favorably moved to the optical head casing 78 via the fixture 90, the temperature difference between the light shielding filter 10 and the filter holder 80, and the filter holder 80 A temperature difference from the optical head casing 78 can be reduced. As a result, it is possible to prevent a problem that the mounting position of the light shielding filter 10 with respect to the filter holder 80 and the mounting position of the filter holder 80 with respect to the optical head casing 78 are shifted and the shape of the annular light is deteriorated. The fixture 90 corresponds to the heat transfer member of the present invention. The light shielding filter installed in the optical head device 2 is not limited to the light shielding filter 10, and other light shielding filters such as the light shielding filters 20 and 30 may be used.

以上、本発明の実施形態および変形例について説明したが、本発明の実施にあたっては、上記実施形態や変形例に限定されるものではなく、本発明の目的を逸脱しない限りにおいて種々の変形も可能である。   Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the object of the present invention. It is.

例えば、上記実施形態および変形例においては、遮光フィルタは、透明基板と遮光部材との２部品を接着して形成されるが、１部品にて形成するようにしてもよい。また、透明基板にレーザ光の光軸と直交する平面を備えない窪みを形成するようにしてもよい。例えば、図９に示す遮光フィルタ１００のように、透明基板１０１の中央に半球形状の窪み１０２を形成し、その窪み１０２の表面に遮光材料１０３をコーティングして形成したものであってもよい。また、図１０に示す遮光フィルタ１１０のように、透明基板１１１の中央に円錐形状あるいは角錐形状の窪み１１２を形成し、その窪み１１２の表面に遮光材料１１３をコーティングして形成したものであってもよい。また、図１１に示す遮光フィルタ１２０のように、透明基板１２１の中央に波形状部１２２を形成し、その波形状部１２２の表面に遮光材料１２３をコーティングして形成したものであってもよい。この波形状部１２２は、同心円状に配置された複数のリング状の波形状が好ましい。   For example, in the above-described embodiment and the modification, the light shielding filter is formed by bonding two parts of the transparent substrate and the light shielding member, but may be formed by one part. Moreover, you may make it form the hollow which does not have the plane orthogonal to the optical axis of a laser beam in a transparent substrate. For example, like the light shielding filter 100 shown in FIG. 9, a hemispherical depression 102 may be formed at the center of the transparent substrate 101, and the light shielding material 103 may be coated on the surface of the depression 102. Further, like the light shielding filter 110 shown in FIG. 10, a conical or pyramidal depression 112 is formed at the center of the transparent substrate 111, and the surface of the depression 112 is coated with a light shielding material 113. Also good. Further, like the light shielding filter 120 shown in FIG. 11, a wave shape portion 122 may be formed at the center of the transparent substrate 121 and the surface of the wave shape portion 122 may be coated with a light shielding material 123. . The corrugated portion 122 is preferably a plurality of ring-shaped corrugated shapes arranged concentrically.

また、上記実施形態および変形例においては、遮光域で反射する反射光を遮蔽する筒体（対物レンズホルダ７０、あるいは、フィルタホルダ８０）を備えた構成であるが、反射光が外乱として殆ど影響しない光ヘッド装置であれば、筒体の軸方向の長さを短くしてもよいし、筒体を省略してもよい。また、上記実施形態および変形例においては、遮光フィルタを光ヘッド装置のようにレーザ光を集光して照射する装置に適用したが、レーザ光を集光したときのスポット径を小さくする以外の目的でレーザ光を輪帯光にする必要がある装置に適用してもよい。   Further, in the above-described embodiment and the modification, the configuration includes the cylindrical body (the objective lens holder 70 or the filter holder 80) that shields the reflected light reflected in the light shielding area. However, the reflected light has almost no influence as a disturbance. If the optical head device does not, the axial length of the cylinder may be shortened, or the cylinder may be omitted. Moreover, in the said embodiment and modification, although the light-shielding filter was applied to the apparatus which condenses and irradiates a laser beam like an optical head apparatus, except for making the spot diameter small when condensing a laser beam. You may apply to the apparatus which needs to make a laser beam into annular light for the objective.

実施形態に係る遮光フィルタを表す概略図で、（ａ）はその斜視図、（ｂ）はその横断面図、（ｃ）はその正面図である。It is the schematic showing the light shielding filter which concerns on embodiment, (a) is the perspective view, (b) is the cross-sectional view, (c) is the front view. 実施形態に係る光ヘッド装置の概略構成図である。1 is a schematic configuration diagram of an optical head device according to an embodiment. 第１変形例に係る遮光フィルタを表す概略図で、（ａ）はその斜視図、（ｂ）はその横断面図、（ｃ）はその正面図である。It is the schematic showing the light shielding filter which concerns on a 1st modification, (a) is the perspective view, (b) is the cross-sectional view, (c) is the front view. 第２変形例に係る遮光フィルタを表す概略図で、（ａ）はその斜視図、（ｂ）はその横断面図、（ｃ）はその正面図である。It is the schematic showing the light shielding filter which concerns on a 2nd modification, (a) is the perspective view, (b) is the cross-sectional view, (c) is the front view. 変形例に係る光ヘッド装置の概略構成図である。It is a schematic block diagram of the optical head apparatus which concerns on a modification. 変形例に係るフィルタホルダの一部破断斜視図である。It is a partially broken perspective view of the filter holder concerning a modification. 変形例に係るフィルタホルダの取付状態を表す斜視図である。It is a perspective view showing the attachment state of the filter holder which concerns on a modification. 変形例に係るフィルタホルダの取付状態を表す正面図である。It is a front view showing the attachment state of the filter holder which concerns on a modification. 他の変形例に係る遮光フィルタの横断面図である。It is a cross-sectional view of a light shielding filter according to another modification. 他の変形例に係る遮光フィルタの横断面図である。It is a cross-sectional view of a light shielding filter according to another modification. 他の変形例に係る遮光フィルタの横断面図である。It is a cross-sectional view of a light shielding filter according to another modification.

符号の説明Explanation of symbols

１，２…光ヘッド装置、１０，２０，３０，１００，１１０，１２０…遮光フィルタ、１１，１０１，１１１，１２１…透明基板、１２，２２，３２…遮光部材、１５，２５，３５…遮光域、２６，２６，３６…透光域、５０…レーザ光源、６０，７６…フォトディテクタ、６４…光強度変換素子、６８…対物レンズ、７０…対物レンズホルダ、８０…フィルタホルダ、７８…光ヘッドケーシング、９０…取付具。   DESCRIPTION OF SYMBOLS 1, 2 ... Optical head apparatus 10, 20, 30, 100, 110, 120 ... Light shielding filter, 11, 101, 111, 121 ... Transparent substrate, 12, 22, 32 ... Light shielding member, 15, 25, 35 ... Light shielding , 26, 26, 36 ... translucent zone, 50 ... laser light source, 60,76 ... photo detector, 64 ... light intensity conversion element, 68 ... objective lens, 70 ... objective lens holder, 80 ... filter holder, 78 ... optical head Casing, 90 ... fixture.

Claims (7)

レーザ光が入射する領域の中央部に遮光域を、その遮光域の周囲に輪帯状の透光域を備えて、入射したレーザ光を輪帯光にして透過する遮光フィルタにおいて、
前記遮光域は、レーザ光の入射面が前記レーザ光の光軸に対して直交する平面を有さないように形成されたことを特徴とする遮光フィルタ。 In a light shielding filter that includes a light shielding area at the center of a region where laser light is incident and a ring-shaped light transmitting area around the light shielding area, and transmits incident laser light as annular light,
The light-shielding filter is characterized in that the light-shielding area is formed so that a laser light incident surface does not have a plane perpendicular to the optical axis of the laser light. 前記遮光域は、半球形状、円錐形状、角錐形状の何れかの形状に形成されていることを特徴とする請求項１記載の遮光フィルタ。   The light shielding filter according to claim 1, wherein the light shielding area is formed in any one of a hemispherical shape, a conical shape, and a pyramid shape. 遮光材料をコーティングした遮光体を、透明平板の中央部に接着して構成される請求項１または２記載の遮光フィルタ。   The light-shielding filter according to claim 1, wherein a light-shielding body coated with a light-shielding material is bonded to the center of the transparent flat plate. 前記遮光体は、半球形状、円錐形状、角錐形状の何れかの形状に形成されていることを特徴とする請求項３記載の遮光フィルタ。   The light shielding filter according to claim 3, wherein the light shielding body is formed in any one of a hemispherical shape, a conical shape, and a pyramid shape. 前記レーザ光の光軸を中心軸にした筒体内に取り付けられたことを特徴とする請求項１ないし請求項４の何れか一項記載の遮光フィルタ。   The light-shielding filter according to claim 1, wherein the light-shielding filter is mounted in a cylindrical body having an optical axis of the laser light as a central axis. レーザ光を出射するレーザ光源と、前記出射されたレーザ光を平行光にするコリメーティングレンズと、前記平行光にされたレーザ光を集光する対物レンズとを少なくとも備える光ヘッド装置において、前記レーザ光源から前記対物レンズまでの光路上に、請求項１ないし請求項５の何れかに記載の遮光フィルタを設置したことを特徴とする光ヘッド装置。   In the optical head device comprising at least a laser light source that emits laser light, a collimating lens that collimates the emitted laser light, and an objective lens that condenses the collimated laser light, 6. An optical head device, wherein the light shielding filter according to claim 1 is installed on an optical path from a laser light source to the objective lens. 請求項５記載の遮光フィルタを設置した請求項６記載の光ヘッド装置において、
前記筒体は、その側面を覆う熱伝達用部材を介して光ヘッドケーシングに熱伝達可能に取り付けされていることを特徴とする光ヘッド装置。 The optical head device according to claim 6, wherein the light shielding filter according to claim 5 is installed.
An optical head device characterized in that the cylindrical body is attached to an optical head casing through a heat transfer member covering a side surface thereof so as to be able to transfer heat.
JP2008323044A 2008-12-19 2008-12-19 Shielding filter and optical head device Expired - Fee Related JP5062159B2 (en)

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JPH06148575A (en) * 1992-10-30 1994-05-27 Sony Corp Optical element and optical head
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JP2000339746A (en) * 1999-06-01 2000-12-08 Hitachi Maxell Ltd Recording and reproducing device and photoirradiation method
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