JP2011053605A - Liquid crystal optical element, method of manufacturing the same and pickup apparatus provided with the same - Google Patents

Liquid crystal optical element, method of manufacturing the same and pickup apparatus provided with the same Download PDF

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JP2011053605A
JP2011053605A JP2009204691A JP2009204691A JP2011053605A JP 2011053605 A JP2011053605 A JP 2011053605A JP 2009204691 A JP2009204691 A JP 2009204691A JP 2009204691 A JP2009204691 A JP 2009204691A JP 2011053605 A JP2011053605 A JP 2011053605A
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liquid crystal
electrode
optical element
crystal optical
drive electrode
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Yoshiharu Takane
義晴 高根
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Citizen Holdings Co Ltd
Citizen Electronics Co Ltd
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Citizen Holdings Co Ltd
Citizen Electronics Co Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal optical element which does not disturb vertical alignment of liquid crystal molecules even when there is a region where a liquid crystal layer is not driven in an effective region; to provide a method of manufacturing the liquid crystal optical element; and to provide an optical pickup apparatus provided with the liquid crystal optical element. <P>SOLUTION: A dummy electrode 18a which is made of the same material as that of a driving electrode 18 and is electrically insulated from the driving electrode 18 is arranged in a region where there is no driving electrode 18 in the effective region 15. The driving electrode 18 and the dummy electrode 18a are covered with a vertically aligned film 19. Thus, in a driving electrode region and a non-driving electrode region, substrate conditions of the vertical alignment films 19 are made common and alignment disorder is hardly caused. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、垂直配向型の液晶光学素子とその製造方法及びこの液晶光学素子を備えたピックアップ装置に関する。   The present invention relates to a vertical alignment type liquid crystal optical element, a method for manufacturing the same, and a pickup device including the liquid crystal optical element.

光ディスクの読み書きに使用するピックアップ装置は、レーザー光源やプリズムやレンズなどからなる光学系を備えている。レーザー光源から出射したレーザービームはプリズムやレンズを経て光ディスク上でスポットを結び、この反射光が再びピックアップ装置に戻り受光素子に達する。このピックアップ装置のレーザー光路中に液晶光学素子を挿入し、この液晶光学素子で偏光や波面を制御し対物レンズの開口数調整、収差補正、ピント調整などを行なうことがある。   A pickup device used for reading and writing an optical disk includes an optical system including a laser light source, a prism, a lens, and the like. The laser beam emitted from the laser light source forms a spot on the optical disk through a prism and a lens, and this reflected light returns to the pickup device again and reaches the light receiving element. In some cases, a liquid crystal optical element is inserted into the laser beam path of the pickup device, and the liquid crystal optical element controls polarization and wavefront to adjust the numerical aperture of the objective lens, aberration correction, focus adjustment, and the like.

例えば特許文献１に記載されている記録・再生装置は、ＴＮ（ツイストネマチック）液晶セル（液晶光学素子）を対物レンズの直前に配置し、対物レンズの実質的な開口数を変更して光ディスク面上の光スポット径を調節している。これで記録密度が異なる２種類以上の光ディスクに対して情報の記録・再生が行えるようになる。また特許文献１の段落（０００９）おいて「対物レンズの開口径の可変を電気的に制御することができる。」と記載されているように、ふつう液晶光学素子は液晶層を電気的に駆動することが多い。   For example, in the recording / reproducing apparatus described in Patent Document 1, a TN (twisted nematic) liquid crystal cell (liquid crystal optical element) is disposed immediately before the objective lens, and the substantial numerical aperture of the objective lens is changed to change the optical disk surface. The upper light spot diameter is adjusted. Thus, information can be recorded / reproduced with respect to two or more types of optical disks having different recording densities. In addition, as described in paragraph (0009) of Patent Document 1, “variation of the aperture diameter of the objective lens can be electrically controlled”, the liquid crystal optical element normally electrically drives the liquid crystal layer. Often to do.

特開平５−１２０７２０号公報（段落（０００９））JP 5-120720 A (paragraph (0009))

ＴＮ液晶の代わりに温度特性が良好であることが知られている垂直配向型液晶を使い、前述の対物レンズの開口径を可変にする液晶光学素子を製作したところ、レーザー光が透過する有効領域において駆動電極のない領域で液晶分子の垂直配向が乱れてしまった。すなわちこの配向乱れにより、駆動電極のない領域と駆動電極のある領域との間で屈折率の差が生じ、駆動電極のない領域で干渉縞（モアレパターン）が発生した。     Using a vertical alignment type liquid crystal that is known to have good temperature characteristics instead of the TN liquid crystal, a liquid crystal optical element that makes the aperture diameter of the objective lens variable is manufactured. In FIG. 2, the vertical alignment of the liquid crystal molecules was disturbed in the region where there was no drive electrode. That is, due to this disordered alignment, a difference in refractive index occurs between the region without the drive electrode and the region with the drive electrode, and interference fringes (moire patterns) occur in the region without the drive electrode.

本発明は、前述の問題に鑑みてなされたものであり、有効領域内の駆動電極のない領域において液晶分子の垂直配向が乱れない液晶光学素子及びこれを備えたピックアップ装置を提供することを目的としている。     The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a liquid crystal optical element in which the vertical alignment of liquid crystal molecules is not disturbed in a region where there is no drive electrode in an effective region, and a pickup device including the same. It is said.

駆動電極のない領域で液晶分子の垂直配向が乱れることについて究明したところ、垂直配向の液晶の場合、配向規制力が弱いため、配向膜が形成されている下地の影響を強く受けることが判明した。本発明はこの観点に基づいてなされたものである。
本発明は、２枚の透明基板間に液晶層を挟持し、光線束が通過する有効領域を備える液晶光学素子において、少なくとも一方の透明基板の有効領域に、垂直配向膜と、液晶層を駆動する駆動電極とが設けられていると共に、当該有効領域の駆動電極のない部位に、駆動電極と電気的に絶縁され駆動電極と同じ材料からなるダミー電極が設けられていることを特徴とする。 As a result of investigating that the vertical alignment of the liquid crystal molecules is disturbed in the region where there is no drive electrode, it was found that the vertical alignment liquid crystal is strongly influenced by the substrate on which the alignment film is formed because the alignment control force is weak. . The present invention has been made based on this viewpoint.
The present invention provides a liquid crystal optical element having an effective region through which a light beam passes by sandwiching a liquid crystal layer between two transparent substrates, and driving a vertical alignment film and a liquid crystal layer in the effective region of at least one transparent substrate. And a dummy electrode made of the same material as the drive electrode, which is electrically insulated from the drive electrode, is provided at a portion of the effective region where the drive electrode is not provided.

本発明によれば、有効領域において駆動電極がない領域にも駆動電極と同じ材料からな
るダミー電極が存在する。これにより、垂直配向膜の下地として基板から受ける影響が少なくなり、駆動電極領域もダミー電極領域も同じ条件となるため、駆動電極領域同様ダミー電極領域も垂直配向が安定する。 According to the present invention, there is a dummy electrode made of the same material as the drive electrode even in a region where there is no drive electrode in the effective region. As a result, the influence of the substrate as the base of the vertical alignment film is reduced, and the drive electrode region and the dummy electrode region have the same conditions, so that the dummy electrode region as well as the drive electrode region has a stable vertical alignment.

前述の光線束はレーザービームであることが好ましい。レーザービームは単一波長で偏光方向と位相が揃い直進性に優れた平面波なので、透過光線束の位相や偏光方向を制御する本発明の液晶光学素子においては性能を充分に発揮される。   The aforementioned light bundle is preferably a laser beam. Since the laser beam is a plane wave having a single wavelength and the same polarization direction and phase and excellent in straightness, the liquid crystal optical element of the present invention that controls the phase and the polarization direction of the transmitted light beam exhibits sufficient performance.

ダミー電極が液晶層を挟んで対向する対向電極と電気的に接続することが好ましい。これにより、ダミー電極領域の液晶層を確実に電圧無印状態にすることができる。   It is preferable that the dummy electrode is electrically connected to a counter electrode opposed to the liquid crystal layer. Thereby, the liquid crystal layer in the dummy electrode region can be surely brought into a voltage-free state.

また、本発明は、２枚の基板間に液晶層を挟持し、光線束が通過する有効領域を備える液晶光学素子の製造方法において、複数の有効領域が画成された２枚のマザー基板を用意する工程と、少なくとも一方のマザー基板における有効領域の各々に、垂直配向膜と、液晶を駆動する駆動電極とを形成すると共に、当該有効領域の駆動電極のない部位には、駆動電極と同じ材料からなり駆動電極に接続されたダミー電極を形成する工程と、マザー基板を有効領域毎に切断して個片化すると同時に、駆動電極とダミー電極とを分離する工程と、を有することを特徴としている。これにより製造工程で発生する静電気に対し耐性を強化することができる。 According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal optical element having an effective region in which a liquid crystal layer is sandwiched between two substrates and through which a light beam passes, and the two mother substrates each having a plurality of effective regions are defined. A vertical alignment film and a drive electrode for driving the liquid crystal are formed in each of the preparing step and at least one effective area of the mother substrate, and the same area as the drive electrode is provided in the effective area without the drive electrode. A step of forming a dummy electrode made of a material and connected to the driving electrode; and a step of cutting the mother substrate into individual pieces for each effective area and simultaneously separating the driving electrode and the dummy electrode. It is said. Thereby, tolerance to static electricity generated in the manufacturing process can be enhanced.

さらに、本発明のピックアップ装置は、上記の液晶光学素子を備えることを特徴とするものである。   Furthermore, the pickup device of the present invention is characterized by including the above-described liquid crystal optical element.

本発明によれば、駆動電極領域もダミー電極領域も垂直配向膜の下に同じ電極材料が存在し好ましい下地条件となるので、液晶分子の配向乱れを低減することができる。
本発明の製造方法によれば、製造工程中において、駆動電極とダミー電極との間に電位差が発生しないので、電極の静電破壊を防止することができる。 According to the present invention, since the same electrode material is present under the vertical alignment film in both the drive electrode region and the dummy electrode region, which is a preferable base condition, the alignment disorder of the liquid crystal molecules can be reduced.
According to the manufacturing method of the present invention, since no potential difference is generated between the drive electrode and the dummy electrode during the manufacturing process, electrostatic breakdown of the electrode can be prevented.

本発明の実施形態１に係る液晶光学素子の外観図である。1 is an external view of a liquid crystal optical element according to Embodiment 1 of the present invention. 図１に示す液晶光学素子の断面図である。It is sectional drawing of the liquid crystal optical element shown in FIG. 図１に示す液晶光学素子の電極パターンを示す平面図である。It is a top view which shows the electrode pattern of the liquid crystal optical element shown in FIG. 図1に示す液晶光学素子を備えたピックアップ装置の説明図である。FIG. 2 is an explanatory diagram of a pickup device including the liquid crystal optical element shown in FIG. 図1に示す液晶光学素子を備えたピックアップ装置の説明図である。FIG. 2 is an explanatory diagram of a pickup device including the liquid crystal optical element shown in FIG. 本発明の実施形態２に係る電極パターンを示す平面図である。It is a top view which shows the electrode pattern which concerns on Embodiment 2 of this invention. 図６に示す電極パターンが配列したマザー基板の平面図である。FIG. 7 is a plan view of a mother substrate on which the electrode patterns shown in FIG. 6 are arranged. 本発明の実施形態３に係る電極パターンを示す平面図である。It is a top view which shows the electrode pattern which concerns on Embodiment 3 of this invention. 図８に示す液晶光学素子を備えたピックアップ装置の説明図である。It is explanatory drawing of the pick-up apparatus provided with the liquid crystal optical element shown in FIG. 本発明の実施形態４に係る電極パターンを示す平面図である。It is a top view which shows the electrode pattern which concerns on Embodiment 4 of this invention. 図１０に示す液晶光学素子の使用法を示す説明図である。It is explanatory drawing which shows the usage method of the liquid crystal optical element shown in FIG. 本発明の実施形態５に係る液晶光学素子の外観図である。It is an external view of the liquid crystal optical element which concerns on Embodiment 5 of this invention. 図１２に示す液晶光学素子の電極パターンを示す平面図である。It is a top view which shows the electrode pattern of the liquid crystal optical element shown in FIG. 図１２に示す液晶光学素子を備えたピックアップ装置の説明図である。It is explanatory drawing of the pick-up apparatus provided with the liquid crystal optical element shown in FIG.

以下、添付図面を参照しながら、本発明の好適な実施形態１〜５について詳細に説明する。なお、同一または相当要素には同一の符号を付し重複する説明は省略する。
（実施形態１） Hereinafter, preferred embodiments 1 to 5 of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent element, and the overlapping description is abbreviate | omitted.
(Embodiment 1)

実施形態１の液晶光学素子１０は、対物レンズの開口径を変える開口制限素子である。実施形態１を図１〜５で説明する。図１は実施形態１の液晶光学素子の外観図、図２は図１の液晶光学素子の断面図、図３は図１の液晶光学素子の電極パターンを示す平面図、図４と図５は図１の液晶光学素子を取り付けたピックアップ装置の使用例を示す説明図である。     The liquid crystal optical element 10 of Embodiment 1 is an aperture limiting element that changes the aperture diameter of the objective lens. A first embodiment will be described with reference to FIGS. 1 is an external view of the liquid crystal optical element of Embodiment 1, FIG. 2 is a sectional view of the liquid crystal optical element of FIG. 1, FIG. 3 is a plan view showing an electrode pattern of the liquid crystal optical element of FIG. It is explanatory drawing which shows the usage example of the pick-up apparatus which attached the liquid crystal optical element of FIG.

図１において実施形態１の液晶光学素子１０の構造を説明する。ここで（ａ）は液晶光学素子１０の斜視図、（ｂ）は液晶光学素子１０を上面から見た平面図である。上ガラス基板１１の下に配置された下ガラス基板１２は上ガラス基板１１より延出している。この延出部には外部回路（図示せず）と液晶層を駆動するための電極（図示せず）とを接続するための接続電極１３，１３ａが形成されている。上ガラス基板１１の周辺部にはシール１４（一点鎖線）があり、シール１４の内側にはレーザービームが通過する有効領域１５（一点鎖線）がある。     The structure of the liquid crystal optical element 10 of Embodiment 1 will be described with reference to FIG. Here, (a) is a perspective view of the liquid crystal optical element 10, and (b) is a plan view of the liquid crystal optical element 10 as viewed from above. The lower glass substrate 12 disposed below the upper glass substrate 11 extends from the upper glass substrate 11. Connection electrodes 13 and 13a for connecting an external circuit (not shown) and an electrode (not shown) for driving the liquid crystal layer are formed on the extending portion. There is a seal 14 (one-dot chain line) around the upper glass substrate 11, and an effective region 15 (one-dot chain line) through which the laser beam passes inside the seal 14.

図２において実施形態１の液晶光学素子１０の構造をさらに詳しく説明する。図２は図１（ｂ）のＡ−Ａ線に沿った液晶光学素子１０の断面図である。上ガラス基板１１の下面には共通電極１６が形成され、共通電極１６は略全面が垂直配向膜１７に覆われている。共通電極１６の一部はシール１４と重なっている。シール１４と上下のガラス基板１１，１２からなる空間には液晶層２０が挟持されている。下ガラス基板１２の上面には接続電極１３と駆動電極１８、ダミー電極１８ａ，１８ｂが形成され、駆動電極１８及びダミー電極１８ａ，１８ｂも垂直配向膜１９で覆われている。
なお、各図において縮尺は適宜変更しており、例えば下ガラス基板１２の厚さが０．４ｍｍ程度であるのに対し液晶層２０の厚さは４μｍである。 In FIG. 2, the structure of the liquid crystal optical element 10 of Embodiment 1 will be described in more detail. FIG. 2 is a cross-sectional view of the liquid crystal optical element 10 taken along line AA in FIG. A common electrode 16 is formed on the lower surface of the upper glass substrate 11, and the entire surface of the common electrode 16 is covered with the vertical alignment film 17. A part of the common electrode 16 overlaps the seal 14. A liquid crystal layer 20 is sandwiched in a space formed by the seal 14 and the upper and lower glass substrates 11 and 12. A connection electrode 13, a drive electrode 18, and dummy electrodes 18 a and 18 b are formed on the upper surface of the lower glass substrate 12, and the drive electrode 18 and the dummy electrodes 18 a and 18 b are also covered with a vertical alignment film 19.
In each figure, the scale is appropriately changed. For example, the thickness of the lower glass substrate 12 is about 0.4 mm, whereas the thickness of the liquid crystal layer 20 is 4 μm.

図３において実施形態１の液晶光学素子１０が備える電極を説明する。
共通電極１６は、シール１４中に混練された導電粒子（図示せず）によって接続電極１３と電気的に接続されている。駆動電極１８はもう一方の接続電極１３ａ（図１参照。）を経由して外部回路と電気的に接続されている。共通電極１６、駆動電極１８、ダミー電極１８ａ，１８ｂ及び接続電極１３，１３ａは厚さが１２ｎｍのＩＴＯ膜である。垂直配向膜１７，１９は、厚さが約１０ｎｍのポリイミド膜であり、配向処理されている。液晶層２０の液晶は、屈折率異方性が負のネマチック液晶である。
図３（ａ）は上ガラス基板１１に形成された共通電極１６（対向電極）を示している。共通電極１６は、円形の領域と突出部１６ａとからなり、円形の領域はレーザービームが透過する有効領域１５を含んでいる。突出部１６ａは先端部がシール１４まで達し、そこで接続電極１３と接続する。図３（ｂ）は下ガラス基板１２上に形成された輪帯状の駆動電極１８と、円形をした有効領域１５内のダミー電極１８ａ、輪帯状をした有効領域１５外のダミー電極１８ｂ、接続電極１３，１３ａを示している。駆動電極１８、ダミー電極１８ａ，１８ｂは同心円状に配列し、駆動電極１８とダミー電極１８ａ，１８ｂの間には５μｍ程度の隙間（図示せず）がある。駆動電極１８と接続電極１３ａとが接続し、接続電極１３ａの左側には、孤立した接続電極１３がある。 The electrodes provided in the liquid crystal optical element 10 of Embodiment 1 will be described with reference to FIG.
The common electrode 16 is electrically connected to the connection electrode 13 by conductive particles (not shown) kneaded in the seal 14. The drive electrode 18 is electrically connected to an external circuit via the other connection electrode 13a (see FIG. 1). The common electrode 16, the drive electrode 18, the dummy electrodes 18a and 18b, and the connection electrodes 13 and 13a are ITO films having a thickness of 12 nm. The vertical alignment films 17 and 19 are polyimide films having a thickness of about 10 nm and are subjected to alignment treatment. The liquid crystal of the liquid crystal layer 20 is a nematic liquid crystal having a negative refractive index anisotropy.
FIG. 3A shows the common electrode 16 (counter electrode) formed on the upper glass substrate 11. The common electrode 16 includes a circular region and a protrusion 16a, and the circular region includes an effective region 15 through which a laser beam is transmitted. The tip of the projecting portion 16a reaches the seal 14 and is connected to the connection electrode 13 there. FIG. 3B shows an annular drive electrode 18 formed on the lower glass substrate 12, a dummy electrode 18a in the effective area 15 having a circular shape, a dummy electrode 18b outside the effective area 15 having an annular shape, and a connection electrode. 13 and 13a. The drive electrode 18 and the dummy electrodes 18a and 18b are arranged concentrically, and there is a gap (not shown) of about 5 μm between the drive electrode 18 and the dummy electrodes 18a and 18b. The drive electrode 18 and the connection electrode 13a are connected, and there is an isolated connection electrode 13 on the left side of the connection electrode 13a.

次に、図４を参照して、液晶光学素子１０をピックアップ装置に適用し、開口制限されない場合の例を説明する。光源１０１を出射したレーザービーム１０２（光線束、破線）は、液晶光学素子１０に入射する。このとき液晶光学素子１０の駆動電極１８と共通電極１６とは同じ電位にしておく。すなわち駆動電極１８が占める領域の液晶層２０は電圧が印加されずオフとなる。この結果、レーザービーム１０２は液晶光学素子１０からなんの変調も受けずに出射する。その後、発散光であったレーザービーム１０２は、コリメータレンズ１０３で円筒状になり、偏光ビームスプリッター１０６を通過し、λ／４位相差板１０７で円偏光となる。この円偏光となったレーザービーム１０２は対物レンズ１０８により光ディスク１０９上にスポットを結ぶ。光ディスク１０９から反射する際に円偏光
の回転方向が逆になるので、レーザービーム１０２がλ／４位相差板１０７で直線偏光にもどるときに、レーザービーム１０２の偏光方向は、光源１０１を出射した時のレーザービーム１０２の偏光方向と直交している。この結果、レーザービーム１０２は偏光ビームスプリッター１０６で反射し、レンズ１０４で集光され検光子１０５に入射する。 Next, an example in which the liquid crystal optical element 10 is applied to a pickup device and the aperture is not limited will be described with reference to FIG. A laser beam 102 (light beam, broken line) emitted from the light source 101 enters the liquid crystal optical element 10. At this time, the drive electrode 18 and the common electrode 16 of the liquid crystal optical element 10 are set to the same potential. That is, the liquid crystal layer 20 in the region occupied by the drive electrode 18 is turned off without being applied with a voltage. As a result, the laser beam 102 is emitted from the liquid crystal optical element 10 without any modulation. After that, the laser beam 102 which is divergent light becomes a cylindrical shape by the collimator lens 103, passes through the polarization beam splitter 106, and becomes circularly polarized light by the λ / 4 phase difference plate 107. The circularly polarized laser beam 102 is spotted on the optical disk 109 by the objective lens 108. Since the rotation direction of the circularly polarized light is reversed when reflecting from the optical disk 109, when the laser beam 102 returns to the linearly polarized light by the λ / 4 phase difference plate 107, the polarization direction of the laser beam 102 is emitted from the light source 101. It is orthogonal to the polarization direction of the laser beam 102 at the time. As a result, the laser beam 102 is reflected by the polarization beam splitter 106, collected by the lens 104, and enters the analyzer 105.

次に、図５を参照して、液晶光学素子１０をピックアップ装置に適用し、開口制限される場合の例を説明する。光源１０１を出射したレーザービーム１０２ａ（点線）、１０２（破線）は、液晶光学素子１０に入射する。このとき液晶表示素子１０の駆動電極１８と共通電極１６との間に電圧を印加し、駆動電極１８が占める領域の液晶層２０をλ／２位相差板として機能させる。この結果、駆動電極１８の領域を通過したレーザービーム１０２ａは偏光方向が９０°回転し、偏光ビームスプリッター１０６で図の右方向に反射する。ダミー電極１８ａの領域を通過したレーザービーム１０２は何の変調も受けないので、図４のレーザービーム１０２同様に光ディスク１０９上にスポットを結び、反射して検光子１０５に入射する。     Next, an example in which the liquid crystal optical element 10 is applied to a pickup device and the aperture is limited will be described with reference to FIG. Laser beams 102 a (dotted lines) and 102 (broken lines) emitted from the light source 101 enter the liquid crystal optical element 10. At this time, a voltage is applied between the drive electrode 18 and the common electrode 16 of the liquid crystal display element 10 to cause the liquid crystal layer 20 in the region occupied by the drive electrode 18 to function as a λ / 2 phase difference plate. As a result, the polarization direction of the laser beam 102a that has passed through the region of the drive electrode 18 is rotated by 90 °, and reflected by the polarization beam splitter 106 in the right direction in the figure. Since the laser beam 102 that has passed through the region of the dummy electrode 18 a is not subjected to any modulation, a spot is formed on the optical disk 109, is reflected, and is incident on the analyzer 105, similarly to the laser beam 102 of FIG.

図４の開口制限されていない場合と、図５の開口制限されている場合とでは光ディスク１０９上のスポット径が異なるので、異なった規格の光ディスクに対応することができる。
（実施形態２） Since the spot diameter on the optical disk 109 is different between the case where the opening is not restricted in FIG. 4 and the case where the opening is restricted in FIG. 5, it is possible to cope with optical disks of different standards.
(Embodiment 2)

実施形態１の液晶光学素子１０は、製造工程において静電気で駆動電極１８やダミー電極１８ａ，１８ｂが破壊することがある。そこで静電気対策を施した実施形態２を図６と図７で説明する。図６は実施形態２の電極を示す平面図である。図７は図６の電極パターンが配列したマザー基板の平面図である。なお、本実施形態の外観、断面、及び部材は図１，２と略等しい。また本実施形態の液晶光学素子１０をピックアップ装置に適用した場合も実施形態１（図４，５）と等しくなる。   In the liquid crystal optical element 10 of the first embodiment, the drive electrode 18 and the dummy electrodes 18a and 18b may be destroyed by static electricity during the manufacturing process. A second embodiment in which countermeasures against static electricity are taken will be described with reference to FIGS. FIG. 6 is a plan view showing an electrode according to the second embodiment. FIG. 7 is a plan view of a mother substrate on which the electrode patterns of FIG. 6 are arranged. In addition, the external appearance, a cross section, and a member of this embodiment are substantially the same as FIGS. Further, when the liquid crystal optical element 10 of the present embodiment is applied to a pickup device, it is equivalent to the first embodiment (FIGS. 4 and 5).

図６において本実施形態の液晶光学素子１０の電極を説明する。図６（ａ）は上ガラス基板１１の下面に形成された共通電極１６（対向電極）を示し、図３（ａ）と同じものである。図６（ｂ）は下ガラス基板１２の上面に形成された駆動電極１８、ダミー電極１８ａ，１８ｂ、接続電極１３，１３ａ、短絡用電極６２を示している。駆動電極１８は、輪帯状の領域が連続するのを妨げる細い間隙１８ｈを備えている。この間隙１８ｈに配置した隘路により、円形で有効領域１５内のダミー電極１８ａと、輪帯状で有効領域１５の周囲を囲うダミー電極１８ｂとが接続している。駆動電極１８、ダミー電極１８ａ，１８ｂは同心円状に配列し、駆動電極１８と、ダミー電極１８ａ，１８ｂ及び隘路との間には５μｍ程度の隙間（図示せず）がある。隘路の幅は１０μｍ程度である。駆動電極１８と接続電極１３ａ、ダミー電極１８ｂと接続電極１３とが接続している。さらに接続電極１３，１３ａは短絡用電極６２と隘路で接続している。     The electrodes of the liquid crystal optical element 10 of the present embodiment will be described with reference to FIG. FIG. 6A shows the common electrode 16 (counter electrode) formed on the lower surface of the upper glass substrate 11, which is the same as FIG. FIG. 6B shows the drive electrode 18, the dummy electrodes 18 a and 18 b, the connection electrodes 13 and 13 a, and the short-circuit electrode 62 formed on the upper surface of the lower glass substrate 12. The drive electrode 18 includes a narrow gap 18h that prevents the annular zone region from continuing. The circular dummy electrode 18a in the effective region 15 and the dummy electrode 18b surrounding the effective region 15 in a ring shape are connected by a bottleneck disposed in the gap 18h. The drive electrode 18 and the dummy electrodes 18a and 18b are arranged concentrically, and there is a gap (not shown) of about 5 μm between the drive electrode 18, the dummy electrodes 18a and 18b, and the bottleneck. The width of the bottleneck is about 10 μm. The drive electrode 18 and the connection electrode 13a are connected, and the dummy electrode 18b and the connection electrode 13 are connected. Furthermore, the connection electrodes 13 and 13a are connected to the short-circuit electrode 62 via a bottleneck.

図６（ｂ）には、液晶光学素子１０の下側の基板上に形成された電極だけでなく、多数個取りによる製造工程で使用するマザー基板に形成される電極の一部も示されている。つまり液晶光学素子１０を個片にするときには切断線６１により短絡用電極６２が取り除かれ、駆動電極１８とダミー電極１８ａ，１８ｂとが分離し電気的に絶縁する。     FIG. 6B shows not only the electrodes formed on the lower substrate of the liquid crystal optical element 10 but also a part of the electrodes formed on the mother substrate used in the manufacturing process by multi-cavity. Yes. That is, when the liquid crystal optical element 10 is divided into pieces, the short-circuit electrode 62 is removed by the cutting line 61, and the drive electrode 18 and the dummy electrodes 18a and 18b are separated and electrically insulated.

図７によりマザー基板を説明する。図７は本実施形態の液晶光学素子１０の電極がマザー基板上に配列された状況を示している。図７（ａ）は上側のマザー基板７１を示している。マザー基板７１の下面には共通電極１６が１２個分形成されている。液晶光学素子１０を個片にするときには、切断線７２（破線）により上側のマザー基板７１を切断する。図７（ｂ）は下側のマザー基板７３である。マザー基板７３の上面には駆動電極１８とダミー電極１８ａ，１８ｂが１２個分形成され、短絡用電極６２で駆動電極１８とダミー
電極１８ａ，１８ｂが接続している。液晶光学素子１０を個片にするときには、切断線６１（破線）により下マザー基板７３を切断する。なお実際のピックアップ装置で使用する液晶光学素子は外形が数ｍｍ角程度であるので、マザー基板上には数千個分の電極が配列することになる。 The mother substrate will be described with reference to FIG. FIG. 7 shows a state where the electrodes of the liquid crystal optical element 10 of the present embodiment are arranged on the mother substrate. FIG. 7A shows the upper mother board 71. Twelve common electrodes 16 are formed on the lower surface of the mother substrate 71. When the liquid crystal optical element 10 is divided into pieces, the upper mother substrate 71 is cut along a cutting line 72 (broken line). FIG. 7B shows the lower mother board 73. Twelve drive electrodes 18 and 12 dummy electrodes 18 a and 18 b are formed on the upper surface of the mother substrate 73, and the drive electrode 18 and the dummy electrodes 18 a and 18 b are connected by a short-circuit electrode 62. When the liquid crystal optical element 10 is divided into pieces, the lower mother substrate 73 is cut along a cutting line 61 (broken line). Since the liquid crystal optical element used in the actual pickup device has an outer shape of about several millimeters square, thousands of electrodes are arranged on the mother substrate.

前述のようにマザー基板７３上で駆動電極１８とダミー電極１８ａ，１８ｂを短絡させておくと、マザー基板７１，７３に電極を形成してから一個の液晶光学素子１０に分離するまでの製造工程において、静電気が駆動電極１８やダミー電極１８ａ，１８ｂに溜まることがなくなるので静電破壊が防止される。なお本実施形態では、マザー基板７１，７３を重ね合わせたときに共通電極１６とダミー電極１８ａ，１８ｂが接続するようにしている。
（実施形態３） As described above, if the drive electrode 18 and the dummy electrodes 18a and 18b are short-circuited on the mother substrate 73, the manufacturing process from the formation of the electrodes on the mother substrates 71 and 73 to the separation into one liquid crystal optical element 10 is performed. In this case, static electricity is not accumulated on the drive electrode 18 or the dummy electrodes 18a and 18b, so that electrostatic breakdown is prevented. In this embodiment, the common electrode 16 and the dummy electrodes 18a and 18b are connected when the mother substrates 71 and 73 are overlapped.
(Embodiment 3)

実施形態３の液晶光学素子３０は、ピックアップ装置が持つ球面収差を補正する収差補正素子である。本発明の実施形態３を図８と図９で説明する。図８は実施形態３の電極を示す平面図である。図９は図８の液晶光学素子３０を取り付けたピックアップ装置の使用例を示す説明図である。なお、本実施形態の外観は図１と略等しく、断面及び部材も駆動電極１８、ダミー電極１８ａ，１８ｂのパターンが異なるだけで図２と略等しい。製造方法も駆動電極１８、ダミー電極１８ａ，１８ｂのパターンが異なることを除き実施形態２と同じである。   The liquid crystal optical element 30 of the third embodiment is an aberration correction element that corrects spherical aberration of the pickup device. A third embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a plan view showing an electrode of the third embodiment. FIG. 9 is an explanatory view showing an example of use of the pickup device to which the liquid crystal optical element 30 of FIG. 8 is attached. The external appearance of this embodiment is substantially the same as FIG. 1, and the cross-section and members are substantially the same as FIG. 2 except that the patterns of the drive electrode 18 and the dummy electrodes 18a and 18b are different. The manufacturing method is the same as that of the second embodiment except that the patterns of the drive electrode 18 and the dummy electrodes 18a and 18b are different.

図８において本実施形態の液晶光学素子３０の電極を説明する。図８（ａ）は上ガラス基板１１の下面に形成された共通電極１６（対向電極）を示し、図３（ａ）と同じものである。図８（ｂ）は下ガラス基板１２の上面に形成された駆動電極１８、ダミー電極１８ａ，１８ｂ、接続電極１３，１３ａ、短絡用電極６２を示している。駆動電極１８は、円形をした中心側の領域１８ｃと、輪帯状でこの輪帯が連続するのを妨げる細い間隙１８ｈを備えた領域とからなり、それぞれの領域は隘路で接続している。有効領域１５の内側にあるダミー電極１８ａは、輪帯状で、駆動電極１８の隘路を挟むように間隙を備えている。有効領域１５の外側にあるダミー電極１８ｂも輪帯状であり、ダミー電極１８ａとダミー電極１８ｂとが駆動電極１８の間隙に設けられた隘路で接続している。駆動電極１８とダミー電極１８ａ，１８ｂは同心円状に配列している。駆動電極１８とダミー電極１８ａ，１８ｂとの間、及び駆動電極１８とダミー電極１８ａ，１８ｂの隘路との間、駆動電極１８の隘路とダミー電極１８ａ，１８ｂの間には５μｍ程度の隙間（図示せず）がある。なお隘路は１０μｍ程度である。駆動電極１８と接続電極１３ａ、ダミー電極１８ｂと接続電極１３とが接続している。さらに接続電極１３，１３ａは短絡用電極６２と隘路で接続している。     The electrodes of the liquid crystal optical element 30 of this embodiment will be described with reference to FIG. FIG. 8A shows the common electrode 16 (counter electrode) formed on the lower surface of the upper glass substrate 11, which is the same as FIG. 3A. FIG. 8B shows the drive electrode 18, the dummy electrodes 18 a and 18 b, the connection electrodes 13 and 13 a, and the short-circuit electrode 62 formed on the upper surface of the lower glass substrate 12. The drive electrode 18 is composed of a circular central region 18c and a region having a ring shape and a narrow gap 18h that prevents the ring zone from continuing, and each region is connected by a bottleneck. The dummy electrode 18a inside the effective region 15 has a ring shape and has a gap so as to sandwich the bottleneck of the drive electrode 18. The dummy electrode 18 b outside the effective area 15 is also in a ring shape, and the dummy electrode 18 a and the dummy electrode 18 b are connected by a bottleneck provided in the gap between the drive electrodes 18. The drive electrode 18 and the dummy electrodes 18a and 18b are arranged concentrically. A gap of about 5 μm is formed between the drive electrode 18 and the dummy electrodes 18a and 18b, between the drive electrode 18 and the dummy electrodes 18a and 18b, and between the drive electrode 18 and the dummy electrodes 18a and 18b (see FIG. Not shown). The bottleneck is about 10 μm. The drive electrode 18 and the connection electrode 13a are connected, and the dummy electrode 18b and the connection electrode 13 are connected. Further, the connection electrodes 13 and 13a are connected to the short-circuit electrode 62 by a bottleneck.

図８（ｂ）には、液晶光学素子３０の下側の基板上に形成された電極だけでなく、多数個取りによる製造工程で使用するマザー基板に形成される電極の一部も示されている。つまり液晶光学素子３０を個片にするときには切断線６１により短絡用電極６２が取り除かれ、駆動電極１８とダミー電極１８ａ，１８ｂとが分離し電気的に絶縁する。     FIG. 8B shows not only the electrodes formed on the lower substrate of the liquid crystal optical element 30 but also a part of the electrodes formed on the mother substrate used in the manufacturing process by multi-cavity. Yes. That is, when the liquid crystal optical element 30 is divided into pieces, the short-circuit electrode 62 is removed by the cutting line 61, and the drive electrode 18 and the dummy electrodes 18a and 18b are separated and electrically insulated.

図９においてこの液晶光学素子３０をピックアップ装置に適用する例を説明する。光源１０１を出射したレーザービーム１０２（光線束、破線）は、コリメータレンズ１０３で円筒状になり、偏光ビームスプリッター１０６を通過し、液晶光学素子３０に入射する。このとき液晶表示素子３０の駆動電極１８と共通電極１６との間に電圧を印加しておき、駆動電極１８領域を通過するレーザービーム１０２の位相が遅れるようにする。液晶光学素子３０から出射しλ／４位相差板１０７で円偏光となったレーザービーム１０２は、波面９１が凹凸を持ち、このまま対物レンズ１０８に入射する。このレーザービーム１０２は対物レンズ１０８の球面収差と相殺し、集光する波面９２となって光ディスク１０９
上にスポットを結ぶ。光ディスク１０９から反射する際に円偏光の回転方向が逆になったレーザービーム１０２は、λ／４位相差板１０７で直線偏光にもどる。この時のレーザービーム１０２の偏光方向は、光源１０１を出射した時のレーザービーム１０２の偏光方向と直交しているので、液晶光学素子３０を素通りし、偏光ビームスプリッター１０６で反射され、レンズ１０４により集光して検光子１０５に入射する。なお検光子１０５上のスポットは光ディスク１０９上のスポットより大きいので、復路側のレーザービーム１０２に対物レンズ１０８の球面収差が含まれていても問題にならない。
（実施形態４） In FIG. 9, an example in which the liquid crystal optical element 30 is applied to a pickup device will be described. The laser beam 102 (light beam, broken line) emitted from the light source 101 becomes cylindrical by the collimator lens 103, passes through the polarization beam splitter 106, and enters the liquid crystal optical element 30. At this time, a voltage is applied between the drive electrode 18 and the common electrode 16 of the liquid crystal display element 30 so that the phase of the laser beam 102 passing through the region of the drive electrode 18 is delayed. The laser beam 102 emitted from the liquid crystal optical element 30 and circularly polarized by the λ / 4 retardation plate 107 is incident on the objective lens 108 with the wavefront 91 having irregularities. This laser beam 102 cancels out the spherical aberration of the objective lens 108 and becomes a converging wavefront 92, which is the optical disk 109.
Tie a spot on top. The laser beam 102 in which the rotational direction of the circularly polarized light is reversed when reflected from the optical disk 109 is returned to the linearly polarized light by the λ / 4 phase difference plate 107. The polarization direction of the laser beam 102 at this time is orthogonal to the polarization direction of the laser beam 102 when emitted from the light source 101, so that it passes through the liquid crystal optical element 30, is reflected by the polarization beam splitter 106, and is reflected by the lens 104. The light is collected and enters the analyzer 105. Since the spot on the analyzer 105 is larger than the spot on the optical disk 109, there is no problem even if the return side laser beam 102 includes the spherical aberration of the objective lens 108.
(Embodiment 4)

本発明の実施形態４を図１０と図１１で説明する。図１０は実施形態４の電極を示す平面図である。図１１は実施形態４の液晶光学素子の使用法を示す説明図である。なお、本実施形態の外観は図１と略等しく、断面及び部材も駆動電極１８、ダミー電極１８ａ，１８ｂのパターンが異なるだけで図２と略等しい。製造方法も駆動電極１８、ダミー電極１８ａ，１８ｂのパターンが異なることを除き実施形態２と同じである。   A fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a plan view showing an electrode of the fourth embodiment. FIG. 11 is an explanatory diagram showing how to use the liquid crystal optical element of the fourth embodiment. The external appearance of this embodiment is substantially the same as FIG. 1, and the cross-section and members are substantially the same as FIG. 2 except that the patterns of the drive electrode 18 and the dummy electrodes 18a and 18b are different. The manufacturing method is the same as that of the second embodiment except that the patterns of the drive electrode 18 and the dummy electrodes 18a and 18b are different.

図１０において実施形態４の液晶光学素子４０の電極を説明する。この液晶光学素子４０は光線束の方向を変える回折格子である。図１０（ａ）は上ガラス基板１１に形成された共通電極１６（対向電極）を示している。共通電極１６は、方形の領域と突出部１６ａとからなり、方形の領域はレーザービームが透過する有効領域１５を含んでいる。突出部１６ａは先端の領域がシール部１４に達し、そこで接続電極１３と接続する。図１０（ｂ）は下ガラス基板１２上に形成された駆動電極１８、ダミー電極１８ａ，１８ｂ、接続電極１３，１３ａ、短絡用電極６２を示す。駆動電極１８は共通部分から複数の突起が伸びた櫛歯形状を為している。ダミー電極は、櫛歯状に配列し有効領域１５を含むダミー電極１８ａと駆動電極１８の外周を取り囲むダミー電極１８ｂとからなっている。駆動電極１８と、ダミー電極１８ａ，１８ｂとの間には５μｍ程度の隙間（図示せず）がある。駆動電極１８と接続電極１３ａ、ダミー電極１８ｂと接続電極１３とが接続している。さらに接続電極１３，１３ａは短絡用電極６２と隘路で接続している。     The electrodes of the liquid crystal optical element 40 of Embodiment 4 will be described with reference to FIG. The liquid crystal optical element 40 is a diffraction grating that changes the direction of the light beam. FIG. 10A shows the common electrode 16 (counter electrode) formed on the upper glass substrate 11. The common electrode 16 includes a square area and a protrusion 16a, and the square area includes an effective area 15 through which a laser beam is transmitted. The protruding portion 16 a reaches the seal portion 14 at the tip region, and is connected to the connection electrode 13 there. FIG. 10B shows the drive electrode 18, the dummy electrodes 18 a and 18 b, the connection electrodes 13 and 13 a, and the short-circuit electrode 62 formed on the lower glass substrate 12. The drive electrode 18 has a comb shape in which a plurality of protrusions extend from the common portion. The dummy electrode is composed of a dummy electrode 18 a arranged in a comb shape and including the effective region 15, and a dummy electrode 18 b surrounding the outer periphery of the drive electrode 18. There is a gap (not shown) of about 5 μm between the drive electrode 18 and the dummy electrodes 18a and 18b. The drive electrode 18 and the connection electrode 13a are connected, and the dummy electrode 18b and the connection electrode 13 are connected. Further, the connection electrodes 13 and 13a are connected to the short-circuit electrode 62 by a bottleneck.

図１０（ｂ）には、液晶光学素子４０の下側の基板上に形成された電極だけでなく、多数個取りによる製造工程で使用するマザー基板に形成される電極の一部も示されている。つまり液晶光学素子４０を個片にするときには切断線６１により短絡用電極６２が取り除かれ、駆動電極１８とダミー電極１８ａ，１８ｂとが分離し電気的に絶縁する。     FIG. 10B shows not only the electrodes formed on the lower substrate of the liquid crystal optical element 40 but also a part of the electrodes formed on the mother substrate used in the manufacturing process by multi-cavity. Yes. That is, when the liquid crystal optical element 40 is separated into pieces, the short-circuit electrode 62 is removed by the cutting line 61, and the drive electrode 18 and the dummy electrodes 18a and 18b are separated and electrically insulated.

図１１においてこの液晶光学素子４０の使用方法を説明する。図１１（ａ）は駆動電極１８と共通電極１６を同じ電位にしておく場合である。すなわち駆動電極１８の領域の液晶層２０は電圧が印加されずオフとなる。光線束２３は液晶光学素子４０からなんの変調も受けないので直進する。（ｂ）は駆動電極１８と共通電極１６の間に電圧を印加した場合である。すなわち駆動電極１８の領域の液晶層２０はオンとなる。この結果、光線束２３は液晶光学素子４０により回折され進行方向が変わる。     In FIG. 11, a method of using the liquid crystal optical element 40 will be described. FIG. 11A shows the case where the drive electrode 18 and the common electrode 16 are kept at the same potential. That is, the liquid crystal layer 20 in the region of the drive electrode 18 is turned off without being applied with a voltage. The light beam 23 goes straight because it does not receive any modulation from the liquid crystal optical element 40. (B) shows a case where a voltage is applied between the drive electrode 18 and the common electrode 16. That is, the liquid crystal layer 20 in the region of the drive electrode 18 is turned on. As a result, the light beam 23 is diffracted by the liquid crystal optical element 40 and the traveling direction is changed.

この液晶光学素子４０は、ピックアップ装置（図４、５、９）の集光レンズ１０４の前に配置し、レーザービーム１０２の方向を変え、複数の検光子にレーザービーム１０２を分配するのに使うことができる。
（実施形態５） The liquid crystal optical element 40 is disposed in front of the condenser lens 104 of the pickup device (FIGS. 4, 5 and 9), and is used to change the direction of the laser beam 102 and distribute the laser beam 102 to a plurality of analyzers. be able to.
(Embodiment 5)

本発明の実施形態５を図１２〜１４で説明する。図１２は実施形態５の液晶光学素子５０の外観図、図１３は図１２の液晶光学素子５０の電極パターンを示す平面図、図１４は図１２の液晶光学素子５０を取り付けたピックアップ装置の使用例を示す説明図である。     Embodiment 5 of the present invention will be described with reference to FIGS. 12 is an external view of the liquid crystal optical element 50 of the fifth embodiment, FIG. 13 is a plan view showing an electrode pattern of the liquid crystal optical element 50 of FIG. 12, and FIG. 14 is a use of a pickup apparatus to which the liquid crystal optical element 50 of FIG. It is explanatory drawing which shows an example.

図１２において実施形態５の液晶光学素子５０が備える構造を説明する。ここで図１２（ａ）は液晶光学素子５０の斜視図、図１２（ｂ）は液晶光学素子５０を上面から見た平面図、図１２（ｃ）は液晶光学素子５０の側面図である。下ガラス基板１１ａ上に中ガラス基板１２ａと上ガラス基板１１が積層しており、中ガラス基板１２ａは上ガラス基板１１および下ガラス基板１１ａより延出している。この延出部の上面には外部回路（図示せず）と液晶層を駆動するための電極（図示せず）とを接続するための接続電極１３，１３ａが形成されており、同様に延出部の下面にも２本の接続電極（図示せず）が形成されている。上ガラス基板１１の周辺部にはシール１４があり、シール１４の内側にはレーザービームが通過する有効領域１５（一点鎖線）がある。同様に下ガラス基板１１ａの周辺部にもシール１４と同じ形状のシール（図示せず）がある。     A structure provided in the liquid crystal optical element 50 of Embodiment 5 will be described with reference to FIG. 12A is a perspective view of the liquid crystal optical element 50, FIG. 12B is a plan view of the liquid crystal optical element 50 as viewed from above, and FIG. 12C is a side view of the liquid crystal optical element 50. The middle glass substrate 12a and the upper glass substrate 11 are laminated on the lower glass substrate 11a, and the middle glass substrate 12a extends from the upper glass substrate 11 and the lower glass substrate 11a. Connection electrodes 13 and 13a for connecting an external circuit (not shown) and an electrode (not shown) for driving the liquid crystal layer are formed on the upper surface of the extending portion. Two connection electrodes (not shown) are also formed on the lower surface of the portion. A seal 14 is provided at the periphery of the upper glass substrate 11, and an effective region 15 (a chain line) through which the laser beam passes is provided inside the seal 14. Similarly, there is a seal (not shown) having the same shape as the seal 14 at the periphery of the lower glass substrate 11a.

上ガラス基板１１と中ガラス基板１２ａとの間の構造及び部材は、駆動電極１８，ダミー電極１８ａ，１８ｂの配列が若干異るだけで図２と略等しい。下ガラス基板１１ａと中ガラス基板１２aとの間の構造及び部材は、上ガラス基板１１と中ガラス基板１２ａとの間の構造及び部材と、中ガラス基板１２ａを軸として対称である。   The structure and members between the upper glass substrate 11 and the middle glass substrate 12a are substantially the same as those in FIG. 2 except that the arrangement of the drive electrodes 18 and the dummy electrodes 18a and 18b is slightly different. The structure and members between the lower glass substrate 11a and the middle glass substrate 12a are symmetrical with respect to the structure and members between the upper glass substrate 11 and the middle glass substrate 12a and the middle glass substrate 12a as an axis.

図１３において本実施形態の液晶光学素子５０の電極を説明する。図１３（ａ）は上ガラス基板１１の下面に形成された共通電極１６（対向電極）を示し、図３（ａ）と同じものである。図１３（ｂ）は中ガラス基板１２ａの上面に形成された複数の同心円状の駆動電極１８、ダミー電極１８ａ，１８ｂ、接続電極１３，１３ａ、短絡用電極６２を示す。駆動電極１８は、３本の輪帯電極領域と、それぞれの輪帯電極領域を接続する隘路とからなっている。駆動電極１８の各輪帯電極領域は、連続することを妨げるような隙間がある。有効領域１５内のダミー電極１８ａは、中心の円形の領域と輪帯状の領域からなる。ダミー電極１８ａの各領域及び駆動電極１８の外周を取り囲むダミー電極１８ｂは、駆動電極１８の輪帯領域の隙間に配置された隘路で互いに接続している。またダミー電極１８ａの各輪帯領域は駆動電極１８の隘路を挟むような隙間がある。駆動電極１８とダミー電極１８ａ，１８ｂは同心円状に配列している。駆動電極１８とダミー電極１８ａ，１８ｂとの間、及び駆動電極１８とダミー電極１８ａ，１８ｂの隘路との間、駆動電極１８の隘路とダミー電極１８ａ，１８ｂの間には５μｍ程度の隙間（図示せず）がある。なお隘路は１０μｍ程度である。駆動電極１８と接続電極１３ａ、ダミー電極１８ｂと接続電極１３とが接続している。さらに接続電極１３，１３ａは短絡用電極６２と隘路で接続している。     In FIG. 13, the electrodes of the liquid crystal optical element 50 of the present embodiment will be described. FIG. 13A shows the common electrode 16 (counter electrode) formed on the lower surface of the upper glass substrate 11, which is the same as FIG. 3A. FIG. 13B shows a plurality of concentric drive electrodes 18, dummy electrodes 18 a and 18 b, connection electrodes 13 and 13 a, and a short-circuit electrode 62 formed on the upper surface of the middle glass substrate 12 a. The drive electrode 18 includes three annular electrode regions and a bottleneck connecting the respective annular electrode regions. Each annular electrode region of the drive electrode 18 has a gap that prevents it from being continuous. The dummy electrode 18a in the effective region 15 includes a central circular region and a ring-shaped region. Each region of the dummy electrode 18a and the dummy electrode 18b surrounding the outer periphery of the drive electrode 18 are connected to each other by a bottleneck disposed in a gap in the annular zone region of the drive electrode 18. Each annular zone of the dummy electrode 18 a has a gap that sandwiches the bottleneck of the drive electrode 18. The drive electrode 18 and the dummy electrodes 18a and 18b are arranged concentrically. A gap of about 5 μm is formed between the drive electrode 18 and the dummy electrodes 18a and 18b, between the drive electrode 18 and the dummy electrodes 18a and 18b, and between the drive electrode 18 and the dummy electrodes 18a and 18b (see FIG. Not shown). The bottleneck is about 10 μm. The drive electrode 18 and the connection electrode 13a are connected, and the dummy electrode 18b and the connection electrode 13 are connected. Further, the connection electrodes 13 and 13a are connected to the short-circuit electrode 62 by a bottleneck.

中ガラス基板１２ａの下面にも図１３（ｂ）で示した電極が形成され、同様に下ガラス基板１１ａの上面にも図１３（ａ）で示した電極が形成されている。駆動電極１８の輪帯領域は外側になるほど幅が細くなり、同様に隣接する輪帯領域の間隔も外側に行くほど狭くなる。なお、上ガラス基板１１と中ガラス基板１２ａの間の配向膜（図示せず）に施した配向処理方向と、下ガラス基板１１ａと中ガラス基板１２ａの間の配向膜（図示せず）に施した配向処理方向とは直交している。     The electrode shown in FIG. 13B is also formed on the lower surface of the middle glass substrate 12a, and the electrode shown in FIG. 13A is also formed on the upper surface of the lower glass substrate 11a. The width of the annular zone of the drive electrode 18 becomes narrower as it goes outward, and similarly, the interval between adjacent annular zones becomes narrower as it goes outward. The alignment treatment direction applied to the alignment film (not shown) between the upper glass substrate 11 and the middle glass substrate 12a and the alignment film (not shown) between the lower glass substrate 11a and the middle glass substrate 12a are applied. It is orthogonal to the orientation processing direction.

図１４を参照して、液晶光学素子５０をピックアップ装置に適用した例を説明する。光源１０１を出射するレーザービーム１０２（光線束、破線）は、コリメータレンズ１０３で円筒状になり、偏光ビームスプリッター１０６を通過し、液晶光学素子５０に入射する。このとき液晶表示素子５０の駆動電極１８と共通電極１６の間には電圧を印加しておく。これで液晶光学素子５０は凹レンズ（バイナリー形回折レンズ）として振る舞い、レーザービーム１０２を広げる。このレーザービーム１０２は、λ／４位相差板１０７で円偏光となる。この円偏光となったレーザービーム１０２は対物レンズ１０８により光ディスク１０９上にスポットを結ぶ。光ディスク１０９で反射したレーザービーム１０２は逆の経路をたどり偏光ビームスプリッター１０６に戻ってくる。このときのレーザービーム１０２の偏光方向は、光源１０１を出射した時のレーザービーム１０２と直交しているの
で、偏光ビームスプリッター１０６で反射し、レンズ１０４で集光され検光子１０５に入射する。なお液晶光学素子５０のそれぞれの液晶層は、往路と復路のレーザービーム１０２に個別に凹レンズとして作用する。 An example in which the liquid crystal optical element 50 is applied to a pickup device will be described with reference to FIG. A laser beam 102 (light bundle, broken line) emitted from the light source 101 becomes cylindrical by the collimator lens 103, passes through the polarization beam splitter 106, and enters the liquid crystal optical element 50. At this time, a voltage is applied between the drive electrode 18 and the common electrode 16 of the liquid crystal display element 50. As a result, the liquid crystal optical element 50 behaves as a concave lens (binary diffractive lens) and spreads the laser beam 102. The laser beam 102 is circularly polarized by the λ / 4 retardation plate 107. The circularly polarized laser beam 102 is spotted on the optical disk 109 by the objective lens 108. The laser beam 102 reflected by the optical disk 109 follows the reverse path and returns to the polarization beam splitter 106. The polarization direction of the laser beam 102 at this time is orthogonal to the laser beam 102 when emitted from the light source 101, so that it is reflected by the polarization beam splitter 106, collected by the lens 104, and incident on the analyzer 105. Note that each liquid crystal layer of the liquid crystal optical element 50 individually acts as a concave lens on the forward and backward laser beams 102.

液晶光学素子５０の駆動電極１８と共通電極１６との間に電圧を印加しない場合は、液晶光学素子５０がレーザービーム１０２になんの作用も及ぼさないため、液晶光学素子５０を凹レンズとして機能させた場合に比べ焦点位置が近くになる。このようにして液晶光学素子５０を制御することによりスポット位置（像面）を変えられるので、異なった規格の光ディスクに対応することができる。   In the case where no voltage is applied between the drive electrode 18 and the common electrode 16 of the liquid crystal optical element 50, the liquid crystal optical element 50 has no effect on the laser beam 102, so that the liquid crystal optical element 50 functions as a concave lens. The focal position is closer than in the case. Since the spot position (image plane) can be changed by controlling the liquid crystal optical element 50 in this manner, it is possible to deal with optical disks of different standards.

なお、実施形態１〜５は有効領域１５外にもダミー電極１８ｂを備えていた。このダミー電極１８ｂよって、有効領域１５外の配向乱れが抑えられ、この結果、有効領域１５内の配向がさらに安定する。実施形態１〜５の共通電極１６は一個であったが、複数に分割してもよい。この場合、分割した電極の微細な隙間を除いた領域で基板が露出するようなら、ダミー電極を設けなければならない。同様に実施形態１〜５は駆動電極１８が実質的に一本であったが、複数の駆動電極を備えても良い。また本発明は前述の実施形態に限られず、領域によって偏光方向を切り換える偏光切替素子、コマ収差や非点収差を補正する収差補正素子、位相差板などにも適用できる。   In the first to fifth embodiments, the dummy electrode 18 b is also provided outside the effective area 15. The dummy electrode 18b suppresses alignment disturbance outside the effective region 15, and as a result, the alignment in the effective region 15 is further stabilized. Although the common electrode 16 of Embodiments 1-5 was one, you may divide | segment into plurality. In this case, a dummy electrode must be provided if the substrate is exposed in a region excluding fine gaps between the divided electrodes. Similarly, in Embodiments 1 to 5, the drive electrode 18 is substantially one, but a plurality of drive electrodes may be provided. The present invention is not limited to the above-described embodiment, and can also be applied to a polarization switching element that switches the polarization direction depending on the region, an aberration correction element that corrects coma and astigmatism, a retardation plate, and the like.

１０，３０，４０，５０…液晶光学素子、１１，１１ａ，１２，１２ａ…ガラス基板（透明基板）、１３，１３ａ…接続電極、１４…シール、１５…有効領域、１６…共通電極（対向電極）、１８…駆動電極、１８ａ，１８ｂ…ダミー電極、６１，７２…切断線、６２…短絡用電極、７１，７３…マザー基板、１０２，１０２ａ…レーザービーム（光線束）。   DESCRIPTION OF SYMBOLS 10, 30, 40, 50 ... Liquid crystal optical element 11, 11, 11a, 12, 12a ... Glass substrate (transparent substrate), 13, 13a ... Connection electrode, 14 ... Seal, 15 ... Effective area, 16 ... Common electrode (counter electrode) , 18... Drive electrode, 18 a and 18 b. Dummy electrode, 61 and 72... Cutting line, 62. Short-circuit electrode, 71 and 73 ... mother substrate, 102 and 102 a.

Claims (5)

２枚の透明基板間に液晶層を挟持し、光線束が通過する有効領域を備える液晶光学素子において、
少なくとも一方の前記透明基板の前記有効領域に、垂直配向膜と、液晶層を駆動する駆動電極とが設けられていると共に、当該有効領域の前記駆動電極のない部位に、前記駆動電極と電気的に絶縁され前記駆動電極と同じ材料からなるダミー電極が設けられていることを特徴とする液晶光学素子。 In a liquid crystal optical element having an effective region in which a light beam passes through a liquid crystal layer sandwiched between two transparent substrates,
A vertical alignment film and a drive electrode for driving the liquid crystal layer are provided in the effective region of at least one of the transparent substrates, and the drive electrode is electrically connected to a portion of the effective region where the drive electrode is not provided. A liquid crystal optical element, characterized in that a dummy electrode made of the same material as that of the drive electrode is provided. 前記光線束がレーザービームであることを特徴とする請求項１に記載の液晶光学素子。   The liquid crystal optical element according to claim 1, wherein the light beam is a laser beam. 前記ダミー電極が前記液晶層を挟んで対向する対向電極と電気的に接続されていることを特徴とする請求項１又は２に記載の液晶光学素子。   The liquid crystal optical element according to claim 1, wherein the dummy electrode is electrically connected to a counter electrode opposed to the liquid crystal layer with the liquid crystal layer interposed therebetween. ２枚の基板間に液晶層を挟持し、光線束が通過する有効領域を備える液晶光学素子の製造方法において、
複数の前記有効領域が画成された２枚のマザー基板を用意する工程と、
少なくとも一方の前記マザー基板における前記有効領域の各々に、垂直配向膜と、液晶を駆動する駆動電極とを形成すると共に、当該有効領域の前記駆動電極のない部位には、前記駆動電極と同じ材料からなり前記駆動電極に接続されたダミー電極を形成する工程と、
前記マザー基板を前記有効領域毎に切断して個片化すると同時に、前記駆動電極と前記ダミー電極とを分離する工程と、
を有することを特徴とする液晶光学素子の製造方法。 In a method for manufacturing a liquid crystal optical element comprising an effective region in which a light beam passes through a liquid crystal layer sandwiched between two substrates,
Providing two mother substrates each having a plurality of the effective areas defined;
A vertical alignment film and a drive electrode for driving liquid crystal are formed in each of the effective regions in at least one of the mother substrates, and the same material as the drive electrode is formed in a portion of the effective region where the drive electrodes are not provided. Forming a dummy electrode connected to the drive electrode, and
Cutting the mother substrate into pieces for each effective area, and simultaneously separating the drive electrodes and the dummy electrodes;
A method for producing a liquid crystal optical element, comprising: 請求項１〜３のいずれか一項に記載の液晶光学素子を備えることを特徴とするピックアップ装置。
A pickup device comprising the liquid crystal optical element according to claim 1.
JP2009204691A 2009-09-04 2009-09-04 Liquid crystal optical element, method of manufacturing the same and pickup apparatus provided with the same Pending JP2011053605A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07294948A (en) * 1994-04-27 1995-11-10 Casio Comput Co Ltd Liquid crystal display device
JPH0933874A (en) * 1995-07-14 1997-02-07 Sharp Corp Liquid crystal display device and its manufacture
JP2002009407A (en) * 2000-06-20 2002-01-11 Sharp Corp Wiring board
JP2009133910A (en) * 2007-11-28 2009-06-18 Stanley Electric Co Ltd Liquid crystal display

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07294948A (en) * 1994-04-27 1995-11-10 Casio Comput Co Ltd Liquid crystal display device
JPH0933874A (en) * 1995-07-14 1997-02-07 Sharp Corp Liquid crystal display device and its manufacture
JP2002009407A (en) * 2000-06-20 2002-01-11 Sharp Corp Wiring board
JP2009133910A (en) * 2007-11-28 2009-06-18 Stanley Electric Co Ltd Liquid crystal display

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