JP5287221B2

JP5287221B2 - Liquid crystal display

Info

Publication number: JP5287221B2
Application number: JP2008328534A
Authority: JP
Inventors: 哲志吉田
Original assignee: Casio Computer Co Ltd
Current assignee: Casio Computer Co Ltd
Priority date: 2008-12-24
Filing date: 2008-12-24
Publication date: 2013-09-11
Anticipated expiration: 2028-12-24
Also published as: JP2010151995A

Description

この発明は、液晶表示装置に関する。 The present invention relates to a liquid crystal display device.

従来の液晶表示装置は、対向配置された一対の基板間に液晶層が封入され、前記一対の基板の互いに対向する内面の少なくとも一方に、電圧の印加により液晶分子の配向状態を変化させて前記液晶層の光学的特性を制御する複数の電極が設けられた液晶素子と、前記液晶素子を挟んで配置された観察側とその反対側の一対の偏光板と、前記反対側の偏光板の後側（観察側とは反対側）に配置された面光源とにより構成されている（特許文献１参照）。
特開２００２−９８９６３号公報 In the conventional liquid crystal display device, a liquid crystal layer is sealed between a pair of opposed substrates, and the orientation state of liquid crystal molecules is changed by applying a voltage to at least one of the opposed inner surfaces of the pair of substrates. A liquid crystal element provided with a plurality of electrodes for controlling the optical characteristics of the liquid crystal layer, a pair of polarizing plates on the opposite side and the observation side disposed with the liquid crystal element interposed therebetween, and the polarizing plate on the opposite side It is comprised by the surface light source arrange | positioned at the side (opposite side to an observation side) (refer patent document 1).
JP 2002-98963 A

しかし、上記従来の液晶表示装置は、その厚さが厚いという問題をもっている。 However, the conventional liquid crystal display device has a problem that it is thick.

この発明は、薄型化をはかることができる液晶表示装置を提供することを目的としたものである。 An object of this invention is to provide the liquid crystal display device which can achieve thickness reduction.

前記目的を果たすため、本発明の液晶表示装置の一態様は、第１の面と第２の面とを有する液晶素子と、透明な板状部材からなり、当該板状部材の端面に光を入射させる入射端面が形成され、当該板状部材の２つの板面の一方に当該入射端面から入射した光の出射面が形成され、当該出射面を前記液晶素子の前記第２の面に対向させて配置された導光板と、前記導光板の前記入射端面に対向させて配置された発光素子と、前記液晶素子の前記第１の面に対向させて配置され、ベースフィルムと偏光層と保護フィルムとを有する偏光板と、前記導光板の前記出射面に密着させて配置されるとともに、前記液晶素子の前記第２の面に密着させて配置された、前記ベースフィルム及び前記保護フィルムを有さない薄膜状偏光層と、を備える、ことを特徴とする。 In order to achieve the above object, one embodiment of a liquid crystal display device of the present invention includes a liquid crystal element having a first surface and a second surface , and a transparent plate-like member, and emits light to an end surface of the plate-like member. An incident end face to be incident is formed, an exit face of light incident from the incident end face is formed on one of the two plate faces of the plate-like member, and the exit face is opposed to the second face of the liquid crystal element. a light guide plate disposed Te, a light emitting element which is arranged opposite to the incident end face of the light guide plate, is disposed opposite to said first surface before Symbol liquid crystal element, the protective base film and the polarizing layer Yes to a polarizing plate and a film, wherein disposed in close contact with the exit surface Rutotomoni of the light guide plate, wherein disposed in close contact with the second surface of the liquid crystal element, the base film and the protective film a thin-film polarizing layer otherwise comprises, that And butterflies.

この発明の液晶表示装置によれば、薄型化をはかることができる。 According to the liquid crystal display device of the present invention, it is possible to reduce the thickness.

（第１の実施形態）
図１はこの発明の第１の実施例を示す液晶表示装置の断面図であり、この液晶表示装置は、液晶素子１と、前記液晶素子１の観察側とは反対側（以下、後側という）に配置され、前記液晶素子１に向けて照明光を照射する面光源８と、前記液晶素子１と前記面光源８との間に配置された薄膜状の偏光層１５と、前記液晶素子１の観察側に配置された偏光板１７とを備えている。 (First embodiment)
FIG. 1 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention. The liquid crystal display device includes a liquid crystal element 1 and a side opposite to the observation side of the liquid crystal element 1 (hereinafter referred to as a rear side). ), A surface light source 8 that irradiates illumination light toward the liquid crystal element 1, a thin-film polarizing layer 15 disposed between the liquid crystal element 1 and the surface light source 8, and the liquid crystal element 1. And a polarizing plate 17 disposed on the observation side.

前記液晶素子１は、予め定めた間隙を設けて対向配置された観察側とその反対側の一対の透明基板２，３間に液晶層５が封入され、前記一対の基板２，３の互いに対向する内面の少なくとも一方に、電圧の印加により液晶分子の配向状態を変化させて前記液晶層５の光学的特性を制御する複数の透明電極６，７が設けられたものであり、前記一対の基板２，３は、それぞれの周縁部において枠状のシール材４を介して接合され、前記液晶層５は、前記一対の基板２，３間の間隙の前記シール材４で囲まれた領域に封入されている。 In the liquid crystal element 1, a liquid crystal layer 5 is sealed between a pair of transparent substrates 2 and 3 on the opposite side and an observation side which are arranged to face each other with a predetermined gap, and the pair of substrates 2 and 3 are opposed to each other. A plurality of transparent electrodes 6 and 7 for controlling the optical characteristics of the liquid crystal layer 5 by changing the alignment state of liquid crystal molecules by applying a voltage to at least one of the inner surfaces of the pair of substrates. The liquid crystal layer 5 is sealed in a region surrounded by the sealing material 4 in the gap between the pair of substrates 2 and 3. Has been.

この実施例の液晶素子１は、前記電極６，７を一対の基板２，３の内面それぞれに設けたものであり、前記電極６，７のうちの一方の基板、例えば観察側とは反対側の基板（以下、後側基板という）３の内面に設けられた電極７は、行および列方向に配列させて形成された複数の画素電極、他方の基板、つまり観察側基板２の内面に設けられた電極６は、前記複数の画素電極７の配列領域の全域に対向させて形成された一枚膜状の対向電極である。 In the liquid crystal element 1 of this embodiment, the electrodes 6 and 7 are provided on the inner surfaces of a pair of substrates 2 and 3, respectively, and one of the electrodes 6 and 7 is opposite to the observation side, for example, the observation side. The electrodes 7 provided on the inner surface of the first substrate 3 (hereinafter referred to as the rear substrate) are provided on the inner surface of the plurality of pixel electrodes arranged in the row and column directions, the other substrate, that is, the observation-side substrate 2. The formed electrode 6 is a single-film counter electrode formed so as to face the entire array region of the plurality of pixel electrodes 7.

なお、この液晶素子１は、ＴＦＴ（薄膜トランジスタ）をアクティブ素子としたアクティブマトリックス液晶素子であり、図では省略しているが、前記複数の画素電極７が設けられた後側基板３の内面に、前記複数の画素電極７にそれぞれ対応させて配置され、対応する画素電極７にそれぞれ接続された複数のＴＦＴと、各行の複数のＴＦＴに前記ＴＦＴをオンさせるゲート信号を供給する複数の走査線と、各列の複数のＴＦＴに画像データ信号を供給する複数の信号線とが設けられている。 The liquid crystal element 1 is an active matrix liquid crystal element in which a TFT (thin film transistor) is used as an active element. Although omitted in the drawing, the liquid crystal element 1 is formed on the inner surface of the rear substrate 3 provided with the plurality of pixel electrodes 7. A plurality of TFTs arranged corresponding to the plurality of pixel electrodes 7 and connected to the corresponding pixel electrodes 7, respectively, and a plurality of scanning lines for supplying gate signals for turning on the TFTs to the plurality of TFTs in each row; A plurality of signal lines for supplying image data signals to a plurality of TFTs in each column are provided.

また、図では省略しているが、前記観察側基板２の内面には、前記複数の画素電極７と前記対向電極６とが互いに対向する領域からなる複数の画素にそれぞれ対応させて、赤、緑、青の３色のカラーフィルタが設けられている。なお、前記対向電極６は、前記カラーフィルタの上に形成されている。 Although not shown in the drawing, the inner surface of the observation-side substrate 2 is red, corresponding to a plurality of pixels each having a region where the plurality of pixel electrodes 7 and the counter electrode 6 face each other. Three color filters of green and blue are provided. The counter electrode 6 is formed on the color filter.

さらに、前記一対の基板２，３の内面はそれぞれ、前記電極６，７を覆って配向膜（図示せず）を設け、これらの配向膜の膜面を予め定めた方向にラビングすることにより配向処理されており、前記液晶層５の液晶分子は、前記配向処理によって一対の基板２，３それぞれの近傍における配向方向を規定され、予め定めた初期配向状態に配向している。 Further, the inner surfaces of the pair of substrates 2 and 3 are respectively provided with alignment films (not shown) so as to cover the electrodes 6 and 7, and the film surfaces of these alignment films are aligned by rubbing in a predetermined direction. The liquid crystal molecules of the liquid crystal layer 5 have been processed, the alignment directions in the vicinity of each of the pair of substrates 2 and 3 are defined by the alignment process, and are aligned in a predetermined initial alignment state.

一方、前記面光源８は、板状の透明部材からなり、その１つの端面に光を入射させる入射端面１０が形成され、２つの板面の一方に、前記入射端面１０から入射した光の出射面１１が形成され、他方の板面に前記入射端面１０から入射した光を前記出射面１１に向けて内面反射する反射面１２が形成された導光板９と、前記導光板９の入射端面１０に対向させて配置されたＬＥＤ（発光ダイオード）等からなる複数の発光素子１３とにより構成されており、前記液晶素子１の後側に、前記導光板９の出射面１１を前記液晶素子１に対向させて配置されている。 On the other hand, the surface light source 8 is made of a plate-like transparent member, and an incident end face 10 for allowing light to be incident on one end face thereof is formed. A light guide plate 9 formed with a reflection surface 12 for reflecting light incident on the other plate surface from the incident end surface 10 toward the output surface 11; and an incident end surface 10 of the light guide plate 9. And a plurality of light emitting elements 13 composed of LEDs (light emitting diodes) or the like disposed so as to face each other, and an output surface 11 of the light guide plate 9 is disposed on the liquid crystal element 1 on the rear side of the liquid crystal element 1. It is arranged to face each other.

この面光源８は、前記複数の発光素子１３の点灯により、これらの発光素子１３が発する光を前記導光板９により導いて、この導光板９の出射面１１から前記液晶素子１に向けて照射する。 The surface light source 8 guides light emitted from the light emitting elements 13 by the light guide plate 9 when the plurality of light emitting elements 13 are turned on, and irradiates the liquid crystal element 1 from the emission surface 11 of the light guide plate 9. To do.

また、前記液晶素子１の観察側に配置された偏光板１７は、トリアセチルセルロース等の樹脂からなるベースフィルム１８と、このベースフィルム１８上に形成され、一方方向に配向させたヨウ素分子を含有したポリビニルアルコール等の樹脂層からなる薄膜状の偏光層１９と、前記偏光層１９を覆って積層されたトリアセチルセルロース等の樹脂からなる保護フィルム２０とからなっており、前記液晶素子１の観察側基板２の外面に貼り付けられている。 The polarizing plate 17 disposed on the observation side of the liquid crystal element 1 contains a base film 18 made of a resin such as triacetyl cellulose, and iodine molecules formed on the base film 18 and oriented in one direction. A thin film-like polarizing layer 19 made of a resin layer such as polyvinyl alcohol, and a protective film 20 made of a resin such as triacetyl cellulose laminated so as to cover the polarizing layer 19. It is affixed on the outer surface of the side substrate 2.

一方、前記液晶素子１と面光源８との間に配置された薄膜状の偏光層１５は、前記偏光板１７の偏光層１９と実質的に同じものであり、ヨウ素分子を含有したポリビニルアルコール等の樹脂層からなり、前記ヨウ素分子を一方方向に配向させた薄膜からなっている。この偏光層１５は、前記面光源８の導光板９の出射面１１に密着させて配置され、前記出射面１１に貼り付けられている。 On the other hand, a thin film-like polarizing layer 15 disposed between the liquid crystal element 1 and the surface light source 8 is substantially the same as the polarizing layer 19 of the polarizing plate 17, such as polyvinyl alcohol containing iodine molecules. And a thin film in which the iodine molecules are oriented in one direction. The polarizing layer 15 is disposed in close contact with the emission surface 11 of the light guide plate 9 of the surface light source 8 and is attached to the emission surface 11.

さらに、前記偏光層１５の前記液晶素子１と対向する面には、前記偏光層１５を保護するための保護フィルム１６が設けられている。この保護フィルム１６は、前記偏光板１７の保護フィルム２０と実質的に同じもの（トリアセチルセルロース等の樹脂からなるフィルム）であり、前記偏光層１５の上に密着させて設けられている。 Further, a protective film 16 for protecting the polarizing layer 15 is provided on the surface of the polarizing layer 15 facing the liquid crystal element 1. The protective film 16 is substantially the same as the protective film 20 of the polarizing plate 17 (a film made of a resin such as triacetyl cellulose), and is provided in close contact with the polarizing layer 15.

そして、前記面光源８は、前記保護フィルム１６の外面（偏光層１５に接する面とは反対面）を前記液晶素子１の後側基板３の外面に密着させるか、或いは近接させて配置されている。 The surface light source 8 is disposed such that the outer surface of the protective film 16 (the surface opposite to the surface in contact with the polarizing layer 15) is in close contact with or close to the outer surface of the rear substrate 3 of the liquid crystal element 1. Yes.

また、この実施例の液晶表示装置は、前記面光源８の導光板９の出射面１１とは反対側、つまり反射面１２側に、前記導光板９の反射面１２に密着させるか、或いは近接させて配置され、観察側から入射し、前記偏光板１７と液晶素子１と保護フィルム１６及び偏光層１５と前記導光板９とを透過した光を前記観察側へ反射する反射膜１４をさらに備えている。なお、この反射膜１４は、前記導光板９にその入射端面１０から入射して前記導光板９内を導かれた光のうちの前記反射面１２を透過して後側に出射した漏れ光を反射して前記導光板９内に戻す機能も有している。 Further, in the liquid crystal display device of this embodiment, the surface light source 8 is in close contact with or close to the reflection surface 12 of the light guide plate 9 on the side opposite to the emission surface 11 of the light guide plate 9, that is, on the reflection surface 12 side. And a reflective film 14 that is incident on the viewing side and reflects the light transmitted through the polarizing plate 17, the liquid crystal element 1, the protective film 16, the polarizing layer 15, and the light guide plate 9 to the viewing side. ing. The reflection film 14 transmits leaked light that has entered the light guide plate 9 from its incident end face 10 and has been guided through the light guide plate 9 and transmitted through the reflection surface 12 and emitted to the rear side. It also has a function of reflecting back into the light guide plate 9.

また、前記液晶素子１は、前記一対の基板２，３間に、誘電異方性が正のネマティック液晶からなる液晶層５を封入し、その液晶分子を、一対の基板２，３間において実質的に９０°の捩れ角でツイスト配向させたＴＮ型液晶素子であり、前記液晶素子１と面光源８との間に配置された偏光層１５は、その吸収軸を、前記液晶素子１の後側基板３の内面の配向処理方向（配向膜のラビング方向）に対していずれか一方の方向に実質的に４５°の角度で交差する方向に向けて配置され、前記液晶素子１の観察側に配置された偏光板１７は、その吸収軸を、前記偏光層１５の吸収軸に対して実質的に直交する方向に向けて配置されている。 The liquid crystal element 1 encloses a liquid crystal layer 5 made of nematic liquid crystal having positive dielectric anisotropy between the pair of substrates 2 and 3, and the liquid crystal molecules are substantially separated between the pair of substrates 2 and 3. In particular, the polarizing layer 15 arranged between the liquid crystal element 1 and the surface light source 8 has its absorption axis at the rear of the liquid crystal element 1. Arranged in a direction substantially intersecting at an angle of 45 ° with any one direction with respect to the alignment processing direction (rubbing direction of the alignment film) on the inner surface of the side substrate 3, on the observation side of the liquid crystal element 1 The arranged polarizing plate 17 is arranged so that its absorption axis is substantially perpendicular to the absorption axis of the polarizing layer 15.

図２は、前記液晶素子１の一対の基板２，３の内面の配向処理方向と、前記偏光層１５及び偏光板１７の吸収軸の向きを示している。 FIG. 2 shows the alignment treatment direction of the inner surfaces of the pair of substrates 2 and 3 of the liquid crystal element 1 and the directions of the absorption axes of the polarizing layer 15 and the polarizing plate 17.

図２のように、前記液晶素子１の後側基板３の内面は、画面の横軸ｘに対して一方の方向、例えば観察側から見て右回り方向に実質的に４５°の角度で交差する方向３ａに配向処理され、観察側基板２の内面は、前記画面の横軸ｘに対して前記一方の方向とは反対方向（観察側から見て左回り方向）に実質的に４５°の角度で交差する方向２ａに配向処理されており、前記液晶層５の液晶分子は、一対の基板２，３それぞれの近傍において、これらの基板２，３の配向処理方向２ａ，３ａに分子長軸を向けて配向し、前記一対の基板２，３間において、図２に分子配列の捩れ方向を破矢線で示したように、後側基板３から観察側基板２に向かって実質的に９０°の捩れ角でツイスト配向している。 As shown in FIG. 2, the inner surface of the rear substrate 3 of the liquid crystal element 1 intersects the horizontal axis x of the screen in one direction, for example, a clockwise direction when viewed from the observation side at a substantially 45 ° angle. The inner surface of the observation-side substrate 2 is substantially 45 ° in a direction opposite to the one direction (a counterclockwise direction when viewed from the observation side) with respect to the horizontal axis x of the screen. The liquid crystal molecules of the liquid crystal layer 5 are aligned in the direction 2a and 3a of the substrates 2 and 3 in the vicinity of the pair of substrates 2 and 3, respectively. And the twist direction of the molecular arrangement between the pair of substrates 2 and 3 is substantially 90 toward the observation side substrate 2 from the rear side substrate 3 as shown by a broken line in FIG. Twist orientation with a twist angle of °.

そして、前記液晶素子１と面光源８との間に配置された偏光層１５は、その吸収軸１５ａを、前記画面の横軸ｘと実質的に平行な方向、すなわち、前記液晶素子１の後側基板３の内面の配向処理方向３ａに対して観察側から見て左回り方向に実質的に４５°の角度で交差する方向に向けて配置されている。 The polarizing layer 15 disposed between the liquid crystal element 1 and the surface light source 8 has an absorption axis 15a in a direction substantially parallel to the horizontal axis x of the screen, that is, after the liquid crystal element 1. They are arranged in a direction that intersects the orientation direction 3a of the inner surface of the side substrate 3 in a counterclockwise direction as viewed from the observation side at an angle of substantially 45 °.

また、前記液晶素子１の観察側に配置された偏光板１７は、その吸収軸１７ａを、前記画面の横軸ｘと実質的に９０°の角度で交差する方向、すなわち、前記液晶素子１の観察側基板２の内面の配向処理方向２ａに対して観察側から見て左回り方向に実質的に４５°の角度で交差し、且つ前記偏光層１５の吸収軸１５ａに対して実質的に直交する方向に向けて配置されている。 The polarizing plate 17 disposed on the viewing side of the liquid crystal element 1 has a direction in which the absorption axis 17a intersects the horizontal axis x of the screen at an angle of substantially 90 °, that is, the liquid crystal element 1 Crosses the orientation processing direction 2a of the inner surface of the observation side substrate 2 in the counterclockwise direction when viewed from the observation side at an angle of substantially 45 °, and is substantially orthogonal to the absorption axis 15a of the polarizing layer 15. It is arranged in the direction to do.

この液晶表示装置は、前記液晶素子１の後側に面光源８を配置し、さらに前記面光源８の導光板９の後側に反射膜１４を配置しているため、前記面光源８からの照明光を利用する透過表示と、観察側から入射した光（液晶表示装置の使用環境の光である外光）を利用する反射表示とを行うことができる。 In this liquid crystal display device, the surface light source 8 is disposed on the rear side of the liquid crystal element 1, and the reflection film 14 is disposed on the rear side of the light guide plate 9 of the surface light source 8. It is possible to perform transmissive display using illumination light and reflective display using light incident from the observation side (external light which is light in the usage environment of the liquid crystal display device).

なお、透過表示のときは、前記面光源８の導光板９の出射面１１から出射した照明光が、前記偏光層１５によって、その吸収軸１５ａと平行な直線偏光成分が吸収され、前記偏光層１５の吸収軸１５ａに対して直交する振動面をもった直線偏光になって液晶素子１に入射し、前記液晶素子１を、液晶層５の液晶分子の配向状態に応じた複屈折作用を受けて透過した光が、観察側の偏光板１７に入射し、その光のうちの前記偏光板１７の吸収軸１７ａに対して直交する直線偏光が前記偏光板１７を透過して観察側に出射する。 In the case of transmissive display, illumination light emitted from the exit surface 11 of the light guide plate 9 of the surface light source 8 is absorbed by the polarizing layer 15 in a linearly polarized light component parallel to the absorption axis 15a, and the polarizing layer. 15 is linearly polarized light having a vibration plane orthogonal to the absorption axis 15 a and enters the liquid crystal element 1, and the liquid crystal element 1 is subjected to a birefringence action according to the alignment state of the liquid crystal molecules of the liquid crystal layer 5. The transmitted light enters the polarizing plate 17 on the observation side, and linearly polarized light orthogonal to the absorption axis 17a of the polarizing plate 17 out of the light passes through the polarizing plate 17 and exits to the observation side. .

また、反射表示のときは、観察側から入射した光が、観察側の偏光板１７によって、その吸収軸１７ａと平行な直線偏光成分が吸収され、前記偏光板１７の吸収軸１７ａに対して直交する振動面をもった直線偏光になって液晶素子１に入射し、前記液晶素子１を、液晶層５の液晶分子の配向状態に応じた複屈折作用を受けて透過した光が、前記偏光層１５に入射し、その光のうちの前記偏光層１５の吸収軸１５ａに対して直交する直線偏光が前記偏光層１５を透過し、さらに前記面光源８の導光板９を透過して前記反射膜１４により反射され、その反射光が、前記導光板９と偏光層１５と液晶素子１と観察側の偏光板１７を透過して観察側に出射する。 In the case of reflective display, the light incident from the observation side is absorbed by the observation-side polarizing plate 17 with the linearly polarized light component parallel to the absorption axis 17 a and orthogonal to the absorption axis 17 a of the polarizing plate 17. The light that has entered the liquid crystal element 1 in the form of linearly polarized light having a vibrating surface is transmitted through the liquid crystal element 1 under the birefringence action according to the alignment state of the liquid crystal molecules of the liquid crystal layer 5. Of the light, the linearly polarized light orthogonal to the absorption axis 15a of the polarizing layer 15 is transmitted through the polarizing layer 15 and further transmitted through the light guide plate 9 of the surface light source 8 and the reflective film. 14, and the reflected light passes through the light guide plate 9, the polarizing layer 15, the liquid crystal element 1, and the polarizing plate 17 on the observation side and is emitted to the observation side.

前記液晶表示装置は、前記液晶素子１と、前記導光板９とその入射端面１０に対向させて配置された複数の発光素子１３とにより構成され、前記液晶素子１の後側に、前記導光板９の出射面１１を前記液晶素子１に対向させて配置された面光源８と、前記面光源８の導光板９の出射面１１に密着させて配置された薄膜状の偏光層１５と、前記偏光層１５の液晶素子１と対向する面に密着させて設けられた保護フィルム１６と、前記液晶素子１の観察側に配置された偏光板１７とによって構成されているため、装置全体を薄型化することができる。 The liquid crystal display device includes the liquid crystal element 1, the light guide plate 9 and a plurality of light emitting elements 13 disposed to face the incident end face 10, and the light guide plate is disposed behind the liquid crystal element 1. A surface light source 8 disposed with the light exit surface 11 facing the liquid crystal element 1, a thin-film polarizing layer 15 disposed in close contact with the light exit surface 11 of the light guide plate 9 of the surface light source 8, and Since the protective film 16 provided in close contact with the surface of the polarizing layer 15 facing the liquid crystal element 1 and the polarizing plate 17 disposed on the observation side of the liquid crystal element 1, the entire apparatus is thinned. can do.

すなわち、液晶素子を挟んで観察側とその反対側とに一対の偏光板を配置した従来の液晶表示装置は、２枚の偏光板の厚さが液晶表示装置の厚さに大きく影響するため、薄型化をはかることが難しい。 That is, in the conventional liquid crystal display device in which a pair of polarizing plates are arranged on the observation side and the opposite side across the liquid crystal element, the thickness of the two polarizing plates greatly affects the thickness of the liquid crystal display device. It is difficult to reduce the thickness.

なお、前記実施例の液晶表示装置における観察側の偏光板１７の厚さ（ベースフィルム１８と偏光層１９と保護フィルム２０との合計厚さ）は約０．１５ｍｍであり、従来の液晶表示装置は、前記約０．１５ｍｍの厚さの２枚の偏光板を備えているため、この２枚の偏光板の厚さが液晶表示装置の厚さに大きく影響する。 In addition, the thickness of the polarizing plate 17 on the observation side (total thickness of the base film 18, the polarizing layer 19, and the protective film 20) in the liquid crystal display device of the above example is about 0.15 mm, which is a conventional liquid crystal display device. Is provided with the two polarizing plates having a thickness of about 0.15 mm, the thickness of the two polarizing plates greatly affects the thickness of the liquid crystal display device.

一方、前記実施例の液晶表示装置は、観察側の偏光板１７の厚さは約０．１５ｍｍであるが、液晶素子１と面光源８との間に配置された前記薄膜状の偏光層１５の厚さと、前記偏光層１５に密着させて設けられた前記保護フィルム１６の厚さはそれぞれ約０．０５ｍｍであり、この偏光層１５と保護フィルム１６の合計厚さは、約０．１０ｍｍである。 On the other hand, in the liquid crystal display device of the above example, the polarizing plate 17 on the observation side has a thickness of about 0.15 mm, but the thin-film polarizing layer 15 disposed between the liquid crystal element 1 and the surface light source 8. And the thickness of the protective film 16 provided in close contact with the polarizing layer 15 is about 0.05 mm, and the total thickness of the polarizing layer 15 and the protective film 16 is about 0.10 mm. is there.

そして、前記偏光層１５は、前記面光源８の導光板９の出射面１１に密着させて配置され、前記面光源８は、前記偏光層１５に密着させて設けられた前記保護フィルム１６を前記液晶素子１の後側基板３の外面に密着させるか、或いは近接させて配置されているため、前記実施例の液晶表示装置によれば、その厚さを従来の液晶表示装置に比べて薄くすることができる。 The polarizing layer 15 is disposed in close contact with the exit surface 11 of the light guide plate 9 of the surface light source 8, and the surface light source 8 includes the protective film 16 provided in close contact with the polarizing layer 15. Since the liquid crystal element 1 is disposed in close contact with or close to the outer surface of the rear substrate 3, the thickness of the liquid crystal display device according to the embodiment is made thinner than that of the conventional liquid crystal display device. be able to.

なお、前記実施例の液晶表示装置において、前記面光源８は、前記保護フィルム１６を前記液晶素子１の後側基板３の外面に密着させて配置するのが望ましく、このようにすることにより、装置全体をより薄型化することができる。 In the liquid crystal display device of the embodiment, it is desirable that the surface light source 8 is disposed so that the protective film 16 is in close contact with the outer surface of the rear substrate 3 of the liquid crystal element 1. The entire apparatus can be made thinner.

さらに、このように前記面光源８を、前記保護フィルム１６を前記液晶素子１の後側基板３の外面に密着させて配置しているので、液晶層５と反射膜１４との距離が短くなり、前記反射表示のときに、表示画像の影が前記面光源８の後側に配置された反射膜１４上に映り、前記表示画像と、前記反射膜１４上に映った影とが観察側から見えることによる二重像の発生を殆んど目立たなくすることができる。 Furthermore, since the surface light source 8 is arranged in such a manner that the protective film 16 is closely attached to the outer surface of the rear substrate 3 of the liquid crystal element 1, the distance between the liquid crystal layer 5 and the reflective film 14 is shortened. At the time of the reflective display, the shadow of the display image is reflected on the reflective film 14 disposed on the rear side of the surface light source 8, and the display image and the shadow reflected on the reflective film 14 are viewed from the observation side. It is possible to make the generation of double images almost inconspicuous.

すなわち、例えば前記液晶素子１の後側基板３の板厚が０．５０ｍｍ、前記面光源８の導光板９の板厚が０．８０ｍｍ、前記導光板の出射面１１に密着された前記偏光層１５とその上に密着された保護フィルム１６との合計厚さが０．１０ｍｍであり、前記面光源８が、前記保護フィルム１６を前記液晶素子１の後側基板３の外面に密着させて配置され、前記反射膜１４が前記導光板９の出射面１１とは反対側の反射面１２に密着させて配置されている場合、前記液晶素子１の液晶層５の後側の面、つまり前記後側基板３の内面と前記反射膜１４との間の距離Ｌは、１．４０ｍｍである。 That is, for example, the thickness of the rear substrate 3 of the liquid crystal element 1 is 0.50 mm, the thickness of the light guide plate 9 of the surface light source 8 is 0.80 mm, and the polarizing layer is in close contact with the output surface 11 of the light guide plate. 15 and the protective film 16 adhered thereon are 0.10 mm, and the surface light source 8 is disposed in close contact with the outer surface of the rear substrate 3 of the liquid crystal element 1. When the reflective film 14 is disposed in close contact with the reflective surface 12 opposite to the light exit surface 11 of the light guide plate 9, the rear surface of the liquid crystal layer 5 of the liquid crystal element 1, that is, the rear surface. A distance L between the inner surface of the side substrate 3 and the reflective film 14 is 1.40 mm.

そして、前記後側基板３の内面と前記反射膜１４との間の距離Ｌが１．４０ｍｍ程度であれば、観察側から前記液晶素子１の法線方向に対して斜めに傾いた入射角で入射した光の観察側の偏光板１７上における入射点と、前記入射角で入射し、前記反射膜１４により反射された光の前記観察側の偏光板１７上における出射点の位置ずれは極く僅かであり、したがって、表示画像の影が前記反射膜１４上に映っても、その影は前記表示画像に隠れてほとんど視認されない。 If the distance L between the inner surface of the rear substrate 3 and the reflective film 14 is about 1.40 mm, the incident angle is inclined obliquely with respect to the normal direction of the liquid crystal element 1 from the observation side. There is very little misalignment between the incident point of the incident light on the polarizing plate 17 on the observation side and the emission point of the incident light at the incident angle and reflected by the reflective film 14 on the polarizing plate 17 on the observation side. Therefore, even if the shadow of the display image is reflected on the reflective film 14, the shadow is hidden behind the display image and hardly visible.

なお、前記液晶素子１の後側基板３と前記面光源８の導光板９の一方または両方は、より薄い板厚のものが好ましく、例えば、前記後側基板３の板厚を０．１５ｍｍ、前記導光板９の板厚を０．２５ｍｍにすることにより、前記後側基板３の内面と前記反射膜１４との間の距離Ｌを０．５０ｍｍにし、前記二重像の発生をさらに目立たなくすることができる。 One or both of the rear substrate 3 of the liquid crystal element 1 and the light guide plate 9 of the surface light source 8 are preferably thinner, for example, the thickness of the rear substrate 3 is 0.15 mm, By setting the thickness of the light guide plate 9 to 0.25 mm, the distance L between the inner surface of the rear substrate 3 and the reflective film 14 is set to 0.50 mm, and the generation of the double image is less noticeable. can do.

（第２の実施形態）
図３はこの発明の第２の実施例を示す液晶表示装置の断面図である。なお、この実施例において、上記第１の実施例に対応するものには図に同符号を付し、同一のものについてはその説明を省略する。 (Second Embodiment)
FIG. 3 is a sectional view of a liquid crystal display device showing a second embodiment of the present invention. In this embodiment, parts corresponding to those in the first embodiment are given the same reference numerals in the drawings, and description of the same parts is omitted.

この実施例の液晶表示装置は、上記第１の実施例における偏光層１５の保護フィルムを省略し、前記面光源８を、その導光板９の出射面１１に密着された偏光層１５の液晶素子１と対向する面を、前記液晶素子１の後側基板３の外面に密着させて配置したものであり、他の構成は第１の実施例と同じである。 In the liquid crystal display device of this embodiment, the protective film of the polarizing layer 15 in the first embodiment is omitted, and the liquid crystal element of the polarizing layer 15 in which the surface light source 8 is in close contact with the emission surface 11 of the light guide plate 9. 1 is disposed in close contact with the outer surface of the rear substrate 3 of the liquid crystal element 1, and other configurations are the same as those of the first embodiment.

この液晶表示装置は、前記液晶素子１と前記面光源８の導光板９との間に、約０．０５ｍｍの厚さの偏光層１５だけを配置し、この偏光層１５を前記面光源８の導光板９の出射面１１に密着させ、さらに前記面光源８を、前記偏光層１５を前記液晶素子１の後側基板３の外面に密着させて配置しているため、装置全体の厚さを上記第１の実施例の液晶表示装置よりもさらに薄くすることができる。 In this liquid crystal display device, only a polarizing layer 15 having a thickness of about 0.05 mm is disposed between the liquid crystal element 1 and the light guide plate 9 of the surface light source 8, and this polarizing layer 15 is disposed on the surface light source 8. Since the surface light source 8 is disposed in close contact with the light exit surface 11 of the light guide plate 9, and the polarizing layer 15 is disposed in close contact with the outer surface of the rear substrate 3 of the liquid crystal element 1, the thickness of the entire apparatus can be reduced. It can be made thinner than the liquid crystal display device of the first embodiment.

また、この液晶表示装置は、例えば、前記液晶素子１の後側基板３の板厚を０．１５ｍｍ、前記導光板９の板厚を０．２５ｍｍにし、さらに前記反射膜１４を前記導光板９の出射面１１とは反対面（反射面）１２に密着させて配置したときの前記後側基板３の内面と前記反射膜１４との間の距離Ｌが０．４５ｍｍであるため、前記二重像の発生を、さらに目立たなくすることができる。 Further, in this liquid crystal display device, for example, the rear substrate 3 of the liquid crystal element 1 has a thickness of 0.15 mm, the light guide plate 9 has a thickness of 0.25 mm, and the reflective film 14 is formed on the light guide plate 9. because the emission surface 11 a distance L between the inner surface and the reflective layer 14 of the rear substrate 3 when disposed in close contact with the opposite surface (reflecting surface) 12 is 0.4 5 mm, the The generation of double images can be made less noticeable.

（他の実施形態）
なお、上記第１及び第２の実施例の液晶表示装置は、液晶分子を一対の基板２，３間において実質的に９０°の捩れ角でツイスト配向させたＴＮ型の液晶素子１を備え、且つ、前記偏光層１５と観察側の偏光板１７とを、それぞれの吸収軸１５ａ，１７ａを前記液晶素子１の一対の基板２，３の配向処理方向２ａ，３ａに対して実質的に４５°の角度で交差する方向に向けて配置したものであるが、前記偏光層１５と観察側の偏光板１７は、それぞれの吸収軸１５ａ，１７ａを前記液晶素子１の一対の基板２，３の配向処理方向２ａ，３ａに対して実質的に直交または平行な方向に向けて配置してもよい。 (Other embodiments)
The liquid crystal display devices of the first and second embodiments include a TN liquid crystal element 1 in which liquid crystal molecules are twist-aligned between a pair of substrates 2 and 3 with a twist angle of substantially 90 °. In addition, the polarizing layer 15 and the polarizing plate 17 on the observation side have their absorption axes 15 a and 17 a substantially 45 ° with respect to the alignment treatment directions 2 a and 3 a of the pair of substrates 2 and 3 of the liquid crystal element 1. The polarizing layer 15 and the polarizing plate 17 on the observation side are arranged so that the absorption axes 15a and 17a are aligned with the pair of substrates 2 and 3 of the liquid crystal element 1, respectively. You may arrange | position toward the direction substantially orthogonal or parallel with respect to process direction 2a, 3a.

また、前記液晶素子１は、液晶分子を一対の基板２，３間において１８０°〜２７０°の捩れ角でツイスト配向させたＳＴＮ型、液晶分子を基板面に対して実質的に垂直に配向させた垂直配向型、液晶分子を分子長軸を一方向に揃えて基板面と実質的に平行に配向させた非ツイストの水平配向型、液晶分子をベンド配向させるベンド配向型のいずれか、あるいは強誘電性または反強誘電性液晶素子でもよい。 The liquid crystal element 1 has an STN type in which liquid crystal molecules are twist-aligned between a pair of substrates 2 and 3 at a twist angle of 180 ° to 270 °, and liquid crystal molecules are aligned substantially perpendicular to the substrate surface. Vertical alignment type, non-twisted horizontal alignment type in which liquid crystal molecules are aligned in a direction parallel to the substrate surface with the molecular long axis aligned in one direction, bend alignment type in which liquid crystal molecules are bend-aligned, or strong A dielectric or antiferroelectric liquid crystal element may be used.

さらに、前記液晶素子１は、一対の基板の内面にそれぞれ複数の画素を形成するための電極を設けたものに限らず、一対の基板のいずれか一方の内面に、複数の画素を形成するための第１の電極と、それよりも液晶層側に前記第１の電極と絶縁して形成された複数の細長電極部を有する第２の電極とを設け、これらの電極間に横電界（基板面に沿う方向の電界）を生じさせて液晶分子の配向状態を変化させる横電界制御型のものでもよい。 Furthermore, the liquid crystal element 1 is not limited to the one in which electrodes for forming a plurality of pixels are provided on the inner surfaces of a pair of substrates, but for forming a plurality of pixels on one inner surface of a pair of substrates. And a second electrode having a plurality of elongated electrode portions formed on the liquid crystal layer side of the first electrode and being insulated from the first electrode, and a horizontal electric field (substrate) between the electrodes. A lateral electric field control type that changes the alignment state of liquid crystal molecules by generating an electric field in a direction along the surface).

また、上記実施例の液晶表示装置は、面光源８からの照明光を利用する透過表示と、観察側から入射した光を利用する反射表示とを行うものであるが、この発明は、面光源８からの照明光を利用する透過表示だけを行う表示装置にも適用することができ、その場合は、上記実施例において面光源８の導光板９の後側に配置された反射膜１４は、設けても、設けなくてもよい。 The liquid crystal display device of the above embodiment performs transmissive display using illumination light from the surface light source 8 and reflective display using light incident from the observation side. 8 can also be applied to a display device that performs only transmissive display using illumination light from the light source 8, and in that case, the reflective film 14 disposed on the rear side of the light guide plate 9 of the surface light source 8 in the above-described embodiment, It may or may not be provided.

この発明の第１の実施例を示す液晶表示装置の断面図。1 is a cross-sectional view of a liquid crystal display device showing a first embodiment of the present invention. 第１の実施例における液晶素子の一対の基板の配向処理方向と、偏光層及び偏光板の吸収軸の向きを示す図。The figure which shows the orientation process direction of a pair of board | substrate of the liquid crystal element in a 1st Example, and the direction of the absorption axis of a polarizing layer and a polarizing plate. この発明の第２の実施例を示す液晶表示装置の断面図。Sectional drawing of the liquid crystal display device which shows 2nd Example of this invention.

Explanation of symbols

１…液晶素子、２，３…基板、５…液晶層、６，７…電極、８…面光源、９…導光板、１０…入射端面、１１…出射面、１２…反射面、１３…反射膜、１４…発光素子、１５…偏光層、１６…保護フィルム、１７…偏光板。 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal element, 2, 3 ... Board | substrate, 5 ... Liquid crystal layer, 6, 7 ... Electrode, 8 ... Surface light source, 9 ... Light guide plate, 10 ... Incident end surface, 11 ... Output surface, 12 ... Reflective surface, 13 ... Reflection Film | membrane, 14 ... light emitting element, 15 ... polarizing layer, 16 ... protective film, 17 ... polarizing plate.

Claims

A liquid crystal element having a first surface and a second surface,
It is made of a transparent plate-shaped member, and an incident end surface for making light incident on the end surface of the plate-shaped member is formed, and an exit surface for light incident from the incident end surface is formed on one of the two plate surfaces of the plate-shaped member. A light guide plate disposed with the emission surface facing the second surface of the liquid crystal element;
A light emitting element disposed to face the incident end face of the light guide plate;
Is arranged opposite to said first surface before Symbol liquid crystal device, a polarizing plate having a base film and the polarizing layer and the protective film,
Rutotomoni disposed in close contact with the emitting surface of the light guide plate, wherein disposed in close contact with the second surface of the liquid crystal element, a thin-film polarizing layer without the base film and the protective film,
Equipped with a,
A liquid crystal display device characterized by the above.

2. The liquid crystal display device according to claim 1 , wherein the thin-film polarizing layer is made of a polyvinyl alcohol resin layer containing iodine molecules, and is made of a thin film in which the iodine molecules are oriented in one direction.

It is arranged on the other side of the two plate surfaces of the light guide plate, enters from the first surface side of the liquid crystal element, and passes through the polarizing plate, the liquid crystal element, the thin film polarizing layer, and the light guide plate. the liquid crystal display device according to claim 1 or 2, further comprising a reflective film for reflecting to the light again first surface.