JP3790226B2

JP3790226B2 - 3D display device

Info

Publication number: JP3790226B2
Application number: JP2003087979A
Authority: JP
Inventors: 史朗陶山; 英明高田
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2003-03-27
Filing date: 2003-03-27
Publication date: 2006-06-28
Anticipated expiration: 2023-03-27
Also published as: JP2004294848A

Description

【０００１】
【発明の属する技術分野】
本発明は、三次元表示装置に係わり、特に、立体視の生理的要因間での矛盾を抑制し、かつ、多人数の人が同時に三次元立体像を観察できる三次元表示装置に関する。
【０００２】
【従来の技術】
三次元立体像を表示する装置として、二眼式立体表示装置が知られている（例えば、特許文献参照）。
図１７は、従来の二眼式立体表示装置の一例を示す図であり、この図１７に示す二眼式立体表示装置は、前述の特許文献の図２７に記載されている液晶シャッタ眼鏡方式の立体表示装置である。
以下、この液晶シャッタ眼鏡方式の原理について説明する。
この液晶シャッタ眼鏡方式においては、カメラ（６０２，６０３）により、三次元物体６０１を異なる方向から撮影し、三次元物体６０１を異なる方向から撮影した像（視差像）を生成する。
カメラ（６０２，６０３）により撮影された映像を、映像信号変換装置６０４で合成して１つの映像信号とし、二次元表示装置（例えば、ＣＲＴ表示装置）６０５に入力する。観察者６０７は、液晶シャッタ眼鏡６０６をかけて二次元表示装置６０５の映像を観察する。
ここで、二次元表示装置６０５がカメラ６０３の映像を表示している時に、液晶シャッタ眼鏡６０６は左側が非透過状態、右側が透過状態とされ、また、二次元表示装置６０５がカメラ６０２の映像を表示している時に、液晶シャッタ眼鏡６０６は左側が透過状態、右側が非透過状態とされる。
前記動作を高速で切り替えると、眼の残像効果により両眼に視差像が見えるように感じる。したがって、両眼視差による立体視が可能となる。
【０００３】
なお、本願の発明に関連する先行技術文献情報としては以下のものがある。
【特許文献】
特許第３０２２５５８号公報
【非特許文献】
「液晶・基礎編」、「液晶・応用編」（岡野、小林共編、培風館）
【０００４】
【発明が解決しようとする課題】
しかしながら、前述の図１７に示す液晶シャッタ眼鏡方式は、立体視の生理的要因の中で、両眼視差、輻輳と、ピント調節との間に大きな矛盾が生じる。
即ち、液晶シャッタ眼鏡方式では、両眼視差と輻輳はほぼ満足できるが、ピント面が表示面にあるため、この矛盾により、眼精疲労などを生じるという問題点があった。
本発明は、前記従来技術の問題点を解決するためになされたものであり、本発明の目的は、立体視の生理的要因間での矛盾を抑制し、かつ、多人数の人が同時に三次元立体像を観察することが可能な三次元表示装置を提供することにある。
本発明の前記ならびにその他の目的と新規な特徴は、本明細書の記述及び添付図面によって明らかにする。
【０００５】
【課題を解決するための手段】
本願において開示される発明のうち、代表的なものの概要を簡単に説明すれば、下記の通りである。
即ち、本発明は、右目用の視差像と、左目用の視差像を表示する表示装置と、前記観察者の右目の眼前に設けられ、焦点距離を第１の焦点距離と第２の焦点距離に切替可能な第１の二焦点レンズと、前記観察者の左目の眼前に設けられ、焦点距離を第３の焦点距離と第３の焦点距離に切替可能な第２の二焦点レンズと、前記第１の二焦点レンズの焦点距離を第１の焦点距離と第２の焦点距離とに切り替え、かつ、前記第２の二焦点レンズの焦点距離を第３の焦点距離と第４の焦点距離とに切り替える同期装置とを備える三次元表示装置であって、前記同期装置は、前記第１の二焦点レンズの焦点距離を第１の焦点距離に切り替えたときに、前記表示装置に表示される前記右目用の視差像の輝度と、前記第１の二焦点レンズの焦点距離を第２の焦点距離に切り替えたときに、前記表示装置に表示される前記右目用の視差像の輝度を、前記右目用の視差像および前記左目用の視差像による三次元立体像の奥行き位置に応じて変化させ、かつ、前記第２の二焦点レンズの焦点距離を第３の焦点距離に切り替えたときに、前記表示装置に表示される前記左目用の視差像の輝度と、前記第２の二焦点レンズの焦点距離を第４の焦点距離に切り替えたときに、前記表示装置に表示される前記左目用の視差像の輝度を、前記右目用の視差像および前記左目用の視差像による三次元立体像の奥行き位置に応じて変化させる。
【０００６】
また、本発明では、前記観察者の右目の眼前に設けられる第１のシャッタ手段と、前記観察者の左目の眼前に設けられる第２のシャッタとを備え、前記表示装置は、前記右目用の視差像と前記左目用の視差像とを交互に表示し、前記同期装置は、前記表示装置が前記右目用の視差像を表示するときに、前記第１のシャッタ手段を透過状態、前記第２のシャッタ手段を非透過状態にするとともに、前記第１の二焦点レンズの焦点距離を第１の焦点距離と第２の焦点距離に時分割で切り替え、また、前記表示装置が前記左目用の視差像を表示するときに、前記第１のシャッタ手段を非透過状態、前記第２のシャッタ手段を透過状態にするとともに、前記第２の二焦点レンズの焦点距離を第３の焦点距離と第４の焦点距離に時分割で切り替える。
【０００７】
また、本発明では、前記表示装置の前記観察者側に配置される偏光切替装置と、前記観察者の右目の眼前に設けられる第１のシャッタ手段と、前記観察者の左目の眼前に設けられる第２のシャッタとを備え、前記第１および第２の二焦点レンズは、偏光型二焦点レンズであり、前記表示装置は、前記右目用の視差像と前記左目用の視差像とを交互に表示し、前記同期装置は、前記表示装置が前記右目用の視差像を表示するときに、前記第１のシャッタ手段を透過状態、前記第２のシャッタ手段を非透過状態にするとともに、前記偏光切替装置を制御し、前記偏光切替装置から出力される視差像の偏光方向を第１の方向と第２の方向とに時分割で切り替え、また、前記表示装置が前記左目用の視差像を表示するときに、前記第１のシャッタ手段を非透過状態、前記第２のシャッタ手段を透過状態にするとともに、前記偏光切替装置を制御し、前記偏光切替装置から出力される視差像の偏光方向を第１の方向と第２の方向とに時分割で切り替える。
【０００８】
また、本発明では、前記表示装置の前記観察者側に配置される偏光切替装置と、前記観察者の右目の眼前に設けられ、偏光方向が第１の偏光方向の光を通過させ、偏光方向が第２の偏光方向の光を遮断する第１の手段と、前記観察者の左目の眼前に設けられ、偏光方向が第２の偏光方向の光を通過させ、偏光方向が第１の偏光方向の光を遮断する第２の手段とを備え、前記表示装置は、前記右目用の視差像と前記左目用の視差像とを交互に表示し、前記同期装置は、前記偏光切替器を制御し、前記表示装置が前記右目用の視差像を表示するときに前記偏光切替装置から出力される視差像の偏光方向を第１の偏光方向に切り替えるとともに、前記第１の二焦点レンズの焦点距離を第１の焦点距離と第２の焦点距離に時分割で切り替え、また、前記表示装置が前記左目用の視差像を表示するときに前記偏光切替装置から出力される視差像の偏光方向を第２の偏光方向に切り替えるとともに、前記第２の二焦点レンズの焦点距離を第３の焦点距離と第４の焦点距離に時分割で切り替える。
【０００９】
また、本発明では、前記観察者の右目の眼前に設けられ、偏光方向が第１の偏光方向の光を通過させ、偏光方向が第２の偏光方向の光を遮断する第１の手段と、前記観察者の左目の眼前に設けられ、偏光方向が第２の偏光方向の光を通過させ、偏光方向が第１の偏光方向の光を遮断する第２の手段とを備え、前記表示装置は、偏光方向が第１の偏光方向である前記右目用の視差像と、偏光方向が第２の偏光方向である前記左目用の視差像とを同時に表示し、前記同期装置は、前記第１の二焦点レンズの焦点距離を第１の焦点距離と第２の焦点距離に時分割で切り替え、かつ、前記第２の二焦点レンズの焦点距離を第３の焦点距離と第４の焦点距離に時分割で切り替える。
【００１０】
また、本発明では、前記第１の二焦点レンズと前記表示装置との間に設けられる第１の偏光切替装置と、前記第２の二焦点レンズと前記表示装置との間に設けられる第２の偏光切替装置と、前記第１の偏光切替装置と前記表示装置との間に設けられ、偏光方向が第１の偏光方向の光を通過させ、偏光方向が第２の偏光方向の光を遮断する第１の手段と、前記第２の偏光切替装置と前記表示装置との間に設けられ、偏光方向が第２の偏光方向の光を通過させ、偏光方向が第１の偏光方向の光を遮断する第２の手段とを備え、前記第１および第２の二焦点レンズは、偏光型二焦点レンズであり、前記表示装置は、偏光方向が第１の偏光方向である前記右目用の視差像と、偏光方向が第２の偏光方向である前記左目用の視差像とを同時に表示し、前記同期装置は、前記第１および第２の偏光切替器を制御し、前記第１および第２の偏光切替装置から出力される視差像の偏光方向を第１の偏光方向と第２の偏光方向に時分割で切り替える。
また、本発明では、前記観察者がかけるメガネを備え、前記メガネは、左右のレンズとして、前記第１および第２の可変焦点レンズを有する。
【００１１】
本発明によれば、観察者が、第１および第２の二焦点レンズが左右のレンズとして取り付けられたメガネをかけるなどの方法により、観察者の右目の眼前に第１の二焦点レンズと、前記観察者の左目の眼前に第２の二焦点レンズとを配置し、前述の特許文献に記載されているＤＦＤ（Depth Fused 3-D）方式の三次元表示装置の原理を適用し、右目用及び左目用の視差像のピント面が、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置にあるように、観察者に知覚させるようにしたので、従来の二眼式立体表示装置で問題となっていた眼精疲労などを軽減することが可能となる。
【００１２】
【発明の実施の形態】
以下、図面を参照して本発明の実施の形態を詳細に説明する。
なお、実施の形態を説明するための全図において、同一機能を有するものは同一符号を付け、その繰り返しの説明は省略する。
図１は、本発明の基本となる三次元表示装置の概略構成を示す図である。
図１に示す三次元表示装置は、表示装置２００と、観察者１００の右目の眼前に配置される第１の二焦点レンズ１３１と、観察者１００の左目の眼前に配置される第２の二焦点レンズ１３２と、同期装置２１０とを備える。ここで、表示装置２００は、右目用の視差像（二次元像）と、左目用の視差像を表示する。
ここで、第１の二焦点レンズ１３１は、焦点距離を、第１の焦点距離と第２の焦点距離とに切り替えることができ、また、第２の二焦点レンズ１３２は、焦点距離を、第３の焦点距離と第４の焦点距離とに切り替えることができる。
第１の二焦点レンズ１３１と第２の二焦点レンズ１３２とは、例えば、図１に示すように、メガネの左右のレンズとして取り付けられ、観察者１００は、このメガネをかけて表示装置２００を観察する。
【００１３】
図２は、従来の二眼式立体表示装置における三次元立体像の奥行き位置と、右目用および左目用の視差像におけ表示装置上の位置を示す模式図であり、同図において、１０は表示装置２００の表示面、１１は、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置を表す。
この図２において、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置１１の中の位置ｘ０の画素の、観察者１００が実際に観察する表示装置２００の表示面１０の位置は、右目用の視差像では２１の位置で、左目用の視差像では２２の位置となる。
このように、従来の二眼式立体表示装置では、立体視の生理的要因の中で、両眼視差と輻輳はほぼ満足できるが、右目用及び左目用の視差像のピント面が表示面にあるため、この矛盾により、眼精疲労などを生じるという問題点があった。
なお、図２において、ｄＲ、ｄＬを視差量とすると、位置ｘ０、位置ｘ０の奥行き位置ｚ０、視距離（観察者と表示装置の表示面との間の距離）Ｄ、観察者の両眼間隔Ｅとの間には、下記（１）、（２）式の関係がある。
【数１】
ｄＬ＝ｚ０×（Ｅ／２−ｘ０）／（Ｄ−ｚ０）・・・・・・・・（１）
ｄＲ＝ｚ０×（Ｅ／２＋ｘ０）／（Ｄ−ｚ０）・・・・・・・・（２）
【００１４】
この問題点を解決するために、本実施の形態の三次元表示装置では、前述の特許文献に記載されているＤＦＤ（Depth Fused 3-D）方式の三次元表示装置の原理を適用し、右目用及び左目用の視差像のピント面が、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置にあるように、観察者に知覚させて、従来の二眼式立体表示装置で問題となっていた眼精疲労などを軽減するものである。
以下、本実施の形態の三次元表示装置について説明するが、初めに、ＤＦＤ（Depth Fused 3-D）方式の三次元表示装置の原理について説明する。
図３は、ＤＦＤ方式の三次元表示装置の概略構成を示す図であり、前述の特許文献に図１として図示されている三次元表示装置である。
ＤＦＤ方式の三次元表示装置では、観察者１００の前面に複数の表示面、例えば、表示面（１０１，１０２）（表示面１０１が表示面１０２より観察者１００に近い）を設定し、これらの表示面（１０１，１０２）に複数の二次元像を表示するために、二次元表示装置と種々の光学素子を用いて光学系１０３を構築する。
【００１５】
以下、図３ないし図８を用いて、ＤＦＤ方式の三次元表示装置の表示原理について説明する。
図４に示すように、観察者１００に提示したい三次元物体１０４を、観察者１００の両眼の視線方向から、前述の表示面（１０１，１０２）へ射影した像（以下、「２Ｄ化像」と呼ぶ）（１０５，１０６）を生成する。
この２Ｄ化像の生成方法としては、例えば、視線方向から物体１０４をカメラで撮影した二次元像を用いる方法、あるいは別の方向から撮影した複数枚の二次元像から合成する方法、あるいはコンピュータグラフィックによる合成技術やモデル化を用いる方法など種々の方法がある。
そして、図３に示すように、前記２Ｄ化像（１０５，１０６）を、各々表示面１０１と表示面１０２の双方に、観察者１００の右眼と左眼とを結ぶ線上の一点から見て重なるように表示する。
これは、例えば、２Ｄ化像（１０５，１０６）の各々の中心位置や重心位置の配置と、各々の像の拡大・縮小を制御することで可能となる。
【００１６】
ＤＦＤ方式の三次元表示装置の重要な要点は、前記構成を有する装置上で、２Ｄ化像（１０５，１０６）の各々の輝度を、観察者１００から見た総体的な輝度を一定に保ちつつ、三次元物体１０４の奥行き位置に対応して変えることである。
その変え方の一例を以下に述べる。なお、ここでは、白黒図面であるため、分かりやすいように、以下の図面では輝度の高い方を濃く示してある。
例えば、三次元物体１０４が表示面１０１上にある場合には、図５に示すように、この上の２Ｄ化像１０５の輝度を三次元物体１０４の輝度に等しくし、表示面１０２上の２Ｄ化像１０６の輝度はゼロとする。
次に、例えば、三次元物体１０４が観察者１００より少し遠ざかって表示面１０１より表示面１０２側に少し寄った位置にある場合には、図６に示すように、２Ｄ化像１０５の輝度を少し下げ、２Ｄ化像１０６の輝度を少し上げる。
【００１７】
さらに、例えば、三次元物体１０４が観察者１００よりさらに遠ざかって表示面１０１より表示面１０２側にさらに寄った位置にある場合には、図７に示すように、２Ｄ化像１０５の輝度をさらに下げ、２Ｄ化像１０６の輝度をさらに上げる。
遂に、例えば、三次元物体１０４が表示面１０２上にある場合には、図８に示すように、この上の２Ｄ化像１０６の輝度を三次元物体１０４の輝度に等しくし、表示面１０１上の２Ｄ化像１０５の輝度はゼロとする。
このように表示することにより、観察者（人）１００の生理的あるいは心理的要因あるいは錯覚により、表示しているのが２Ｄ化像（１０５，１０６）であっても、観察者１００にはあたかも表示面（１０１，１０２）の中間に三次元物体１０４が位置しているように感じられる。
即ち、例えば、表示面（１０１，１０２）にほぼ等輝度の２Ｄ化像（１０５，１０６）を表示した場合には、表示面（１０１，１０２）の奥行き位置の中間付近に三次元物体１０４があるように感じられる。
【００１８】
図９に示すように、本実施の形態の三次元表示装置では、同期装置２１０により、観察者１００の右目の眼前に配置された第１の二焦点レンズ１３１の焦点距離を、時分割で２段階に変化させ、表示装置２００に表示された二次元像を結像面１０２１と結像面１０２２とに結像させる。
そして、同期装置２１０により、表示装置２００に表示された二次元像を結像面１０２１に結像させる時に、表示装置２００に第１の視差像を表示し、また、表示装置２００に表示された二次元像を結像面１０２２に結像させる時に、表示装置２００に第２の視差像を表示する。この動作を人間の目の残像時間内に行う。
ここで、第１の視差像と第２の視差像は、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像である。
この場合、位置ｘ０の奥行き位置は、前述の（１）、（２）式により求めることができる。
【００１９】
前述したように、ＤＦＤ方式の三次元表示装置の重要な要点は、２Ｄ化像（１０５，１０６）の各々の輝度を、観察者１００から見た総体的な輝度を一定に保ちつつ、３次元物体１０４の奥行き位置に対応して変えることである。
したがって、前述したように、第１の視差像と第２の視差像として、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００（即ち、結像面（１０２１，１０２２））に表示することにより、観察者１００には、右目用の視差像のピント面が、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置にあるように知覚される。
即ち、第１の視差像と第２の視差像として、右目用の視差像の輝度を一対一に分割した画像を表示装置２００に表示することにより、観察者１００には、結像面（１０２１，１０２２）の中間付近に、右目用の視差像のピント面があるように感じられる。
【００２０】
ここで、右目用の視差像の輝度の分割比率を変化させることにより、観察者１００に感じられる右目用の視差像のピント面は、結像面１０２１から結像面１０２２の間で変化させることができる。
また、左目用の視差像についても、右目用の視差像と同様に表示する。
これにより、観察者１００には、右目用および左目用の視差像のピント面が、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置にあるように感じられるので、本実施の形態の三次元表示装置では、従来の二眼式立体表示装置で問題となっていた眼精疲労などを軽減することができ、これにより、多人数の人が同時に長時間、三次元立体像を観察することが可能となる。
【００２１】
以下、本発明の実施の形態の三次元表示装置について説明する。
図１０は、本発明の実施の形態の三次元表示装置の一例の概略構成を示す図である。
図１０に示す三次元表示装置は、第１の二焦点レンズ１３１の表示装置側に第１のシャッタ装置１４１が配置され、また、第２の二焦点レンズ１３２の表示装置側に第２のシャッタ装置１４２が配置されている点で、図１に示す三次元表示装置と相異する。
図１０に示す三次元表示装置では、表示装置２００が、右目用の視差像および左目用の視差像を交互に表示し、それに合わせて、同期装置２１０は、表示装置２００が右目用の視差像を表示するときに、第１のシャッタ装置１４１を透過状態、第２のシャッタ装置１４２を非透過状態となし、また、表示装置２００が左目用の視差像を表示するときに、第２のシャッタ装置１４２を透過状態、第１のシャッタ装置１４１を非透過状態となす。
【００２２】
また、同期装置２１０は、表示装置２００が右目用の視差像を表示するときに、第１の二焦点レンズ１３１の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）に表示させる。
また、同期装置２１０は、表示装置２００が左目用の視差像を表示するときに、第２の二焦点レンズ１３２の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、左目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
なお、図１０に示す三次元表示装置において、第１および第２のシャッタ装置（１４１，１４２）は、第１および第２の二焦点レンズ（１３１，１３２）の観察者側に設置してもよい。
【００２３】
図１１は、本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
図１１に示す三次元表示装置は、表示装置２００の観察者側に偏光切替装置１３５が配置されるとともに、第１の二焦点レンズ１３１と第２の二焦点レンズ１３２が、偏光型二焦点レンズ（１３３，１３４）である点で図１０に示す三次元表示装置と相異する。
偏光型二焦点レンズ（１３３，１３４）は、入射される光の偏光方向により焦点距離が２段階に変化するレンズであり、入射される光の偏光方向により、図９に示すように、表示置２００に表示された二次元像を、第１の結像面１０２１と第２の結像面１０２２とに結像させることができる。
図１１に示す三次元表示装置では、表示装置２００が、右目用の視差像および左目用の視差像を交互に表示し、同期装置２１０は、表示装置２００が右目用の視差像を表示するときに、第１のシャッタ装置１４１を透過状態、第２のシャッタ装置１４２を非透過状態となし、また、表示装置２００が左目用の視差像を表示するときに、第２のシャッタ装置１４２を透過状態、第１のシャッタ装置１４１を非透過状態となす。
【００２４】
また、同期装置２１０は、表示装置２００が右目用の視差像を表示するときに、偏光切替装置１３５を制御し、偏光切替装置１３５から出力される右目用の視差像の偏光方向を第１の偏光方向と、第２の偏光方向に時分割で切り替えて、偏光型二焦点レンズ１３３の焦点距離を時分割で２段階に変化させるとともに、第１の視差像と第２の視差像として、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
また、同期装置２１０は、表示装置２００が左目用の視差像を表示するときに、偏光切替装置１３５を制御し、偏光切替装置１３５から出力される右目用の視差像の偏光方向を第１の偏光方向と、第２の偏光方向に時分割で切り替えて、偏光型二焦点レンズ１３４の焦点距離を時分割で２段階に変化させるとともに、第１の視差像と第２の視差像として、左目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
なお、図１１に示す三次元表示装置において、第１および第２のシャッタ装置（１４１，１４２）は、偏光型二焦点レンズ（１３３，１３４）の観察者側に設置してもよい。
【００２５】
図１２は、図１１に示す偏光型二焦点レンズ（１３３，１３４）の一例の概略構成を示す図である。
図１２に示す偏光型二焦点レンズは、同図（ａ）、（ｂ）に示すように、固定焦点レンズ３０１と、複屈折領域３０２とから構成される。
ここで、固定焦点レンズ３０１は、例えば、図１２（ｂ）に示すガラスあるいはプラスチック製の凸レンズ、または、図１２（ａ）に示すガラスあるいはプラスチック製の凹レンズ、あるいは、ガラスあるいはプラスチック製の凸レンズ、凹レンズ、プリズムなどの組み合わせによるレンズ系、あるいは、ガラスあるいはプラスチック製の凸レンズ、凹レンズ、プリズムなどの組み合わせによるミラー系等により構成される。
また、複屈折領域３０２、例えば、液晶やＰＬＺＴ等からなる複領域屈折性を有する媒体で構成される。
【００２６】
ここで、固定焦点レンズ３０１の屈折率をｎ１とし、入射光の第１の偏光方向、並びに、第２の偏光方向における、複屈折領域３０２の屈折率を、それぞれｎ２１、ｎ２２とする。
例えば、複屈折領域３０２から光を入射した場合、入射光の偏光方向に応じてそれぞれに屈折率ｎ２１、ｎ２２を感じて進行した後、屈折率ｎ１の固定焦点レンズ３０１と接することになる。
したがって、出射光は、入射光の偏光状態に応じて異なった位置に結像する。即ち、偏光方向により焦点距離が相違する二焦点レンズとして動作する。
逆に、固定焦点レンズ３０１側から入射した場合にも、同様に固有偏光方向に応じた屈折率により、二つの結像面に分離して結像する。
なお、図１２に示すように、複屈折領域３０２が液晶の場合、配向膜３０３を付け加えることにより、複屈折領域３０２側から入射した光に対して、面内均一な分離を得ることができる。
【００２７】
また、図１２に示す偏光型二焦点レンズにおいて、固定焦点レンズ３０１がない場合でも、複屈折領域３０２の片面あるいは両面が、図１２に示すような、レンズ形状やプリズム形状をしている場合には、同様な効果がある。
さらに、複屈折性を有する媒体としては、液晶が屈折率異方性が大きいために有益であり、その種類としては通常のネマティック液晶の他、例えば、高分子分散型液晶、ホログラフィック高分子分散型液晶、高分子液晶、スメクティック液晶、強誘電液晶、高分子安定化強誘電液晶などがある。
さらに、液晶以外でも高分子材料の主軸を揃えて形成することにより複屈折性を得ることができることは明らかである。
本実施の形態の偏光切替装置１３５としては、例えば、電界や電圧により複屈折性を変化できる媒質（例えば、液晶やＰＬＺＴ等）を用いた装置がよく知られている。液晶を用いた装置としては、例えば、前述の非特許文献などに多くの種類が記載されている。
【００２８】
図１３は、本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
図１３に示す三次元表示装置は、表示装置２００の観察者側に偏光切替装置１３５が配置されるとともに、第１の二焦点レンズ１３１の表示装置側に、第１の直線偏光子１５１が配置され、また、第２の二焦点レンズ１３２の表示装置側に第２の直線偏光子１５２が配置されている点で、図１に示す三次元表示装置と相異する。
図１３に示す三次元表示装置では、表示装置２００が、右目用の視差像および左目用の視差像を交互に表示し、それに合わせて、同期装置２１０が、偏光切替装置１３５を制御し、偏光切替装置１３５から出力される右目用の視差像の偏光方向を第１の偏光方向に、偏光切替装置１３５から出力される左目用の視差像の偏光方向を第２の偏光方向に切り替える。
また、直線偏光子１５１は、偏光方向が第１の方向であり、偏光方向が第１の偏光方向の光を通過させ、偏光方向が第２の偏光方向の光を遮断する。
同様に、直線偏光子１５２は、偏光方向が第２の方向であり、偏光方向が第２の偏光方向の光を通過させ、偏光方向が第１の偏光方向の光を遮断する。
【００２９】
また、同期装置２１０は、表示装置２００が右目用の視差像を表示するときに、第１の二焦点レンズ１３１の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
また、同期装置２１０は、表示装置２００が左目用の視差像を表示するときに、第２の二焦点レンズ１３２の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、左目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００（即ち、結像面（１０２１，１０２２）に）に表示させる。
なお、図１３に示す三次元表示装置において、第１および第２の直線偏光子（１５１，１５２）は、第１および第２の二焦点レンズ（１３１，１３２）の観察者側に設置してもよい。
また、図１０、図１１、図１３に示す三次元表示装置において、表示装置２００としては、例えば、ＣＲＴ、液晶ディスプレイ、ＬＥＤディスプレイ、ＥＬディスプレイ、プラズマディスプレイ、ＦＥＤディスプレイ、プロジェクション型ディスプレイ、線描画型ディスプレイなどが使用される。
【００３０】
図１４は、本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
図１４に示す三次元表示装置では、表示装置２００が、偏光方向が第１の方向である右目用の視差像と、偏光方向が第２の方向である左目用の視差像を同時に表示するとともに、第１の二焦点レンズ１３１の表示装置側に、第１の直線偏光子１５１が配置され、また、第２の二焦点レンズ１３２の表示装置側に第２の直線偏光子１５２が配置されている点で、図１に示す三次元表示装置と相異する。
図１４に示す表示装置２００の一例を図１５に示す。
図１５に示す表示装置２００は、第１および第２のプロジェクタ型二次元表示装置（例えば、ＣＲＴ型、ＬＣＤ型、ＩＬＶ型、ＤＭＤ型など）（１６１，１６２）と、スクリーン１６３とで構成される。
ここで、スクリーン１６３は、透過型のスクリーン、あるいは、反射型のスクリーンのどちらでもよい。
【００３１】
スクリーン１６３が透過型のスクリーンの場合は、第１および第２のプロジェクタ型二次元表示装置（１６１，１６２）が、スクリーン１６３の、観察者と反対側に配置され、スクリーン１６３が反射型のスクリーンの場合は、第１および第２のプロジェクタ型二次元表示装置（１６１，１６２）が、スクリーン１６３の観察者側に配置される。
第１のプロジェクタ型二次元表示装置１６１は、偏光方向が第１の方向の第３直線偏光子１５３を有し、右目用の視差像として、偏光方向が第１の方向の視差像をスクリーン１６３に投影する。
第２のプロジェクタ型二次元表示装置１６２は、偏光方向が第２の方向の第４直線偏光子１５４を有し、左目用の視差像として、偏光方向が第２の方向の視差像をスクリーン１６３に投影する。
また、直線偏光子１５１は、偏光方向が第１の方向であり、偏光方向が第１の偏光方向の光を通過させ、偏光方向が第２の偏光方向の光を遮断する。
同様に、直線偏光子１５２は、偏光方向が第２の方向であり、偏光方向が第２の偏光方向の光を通過させ、偏光方向が第１の偏光方向の光を遮断する。
【００３２】
また、同期装置２１０は、第１の二焦点レンズ１３１の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、右目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
また、同期装置２１０は、第２の二焦点レンズ１３２の焦点距離を２段階に時分割で変化させるとともに、第１の視差像と第２の視差像として、左目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。
なお、図１４に示す三次元表示装置において、第１および第２の直線偏光子（１５１，１５２）は、第１および第２の二焦点レンズ（１３１，１３２）の観察者側に設置してもよい。
【００３３】
図１６は、本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
図１６に示す三次元表示装置は、第１の二焦点レンズ１３１と第２の二焦点レンズ１３２が、偏光型二焦点レンズ（１３３，１３４）であり、偏光型二焦点レンズ１３３と直線偏光子１５１との間に第１の偏光切替装置１３６が配置され、かつ、偏光型二焦点レンズ１３４と第２の直線偏光子１５２との間に第２の偏光切替装置１３７が配置される点で図１４に示す三次元表示装置と相異する。
図１６に示す三次元表示装置でも、表示装置２００が、偏光方向が第１の方向である右目用の視差像と、偏光方向が第２の方向である左目用の視差像を同時に表示する。
そして、同期装置２１０は、第１の偏光切替装置１３６と、第２の偏光切替装置１３７とを制御し、第１および第２の偏光切替装置（１３６，１３７）から出力される視差像の偏光方向を第１の偏光方向と、第２の偏光方向に時分割で切り替えるとともに、右目用および左目用の第１の視差像と第２の視差像として、右目用および左目用の視差像の各画素毎に、右目用の視差像および左目用の視差像による三次元立体像の奥行き位置（図２の１１）に応じて、輝度を分配した視差像を表示装置２００に（即ち、結像面（１０２１，１０２２）に）表示させる。なお、図１６に示す三次元表示装置において、偏光型二焦点レンズ（１３３，１３４）として、図１２に示すものが、また、表示装置２００として、図１５に示す表示装置が使用可能である。
【００３４】
なお、前述の説明では、第１および第２の二焦点レンズ（１３１，１３２）、または、偏光型二焦点レンズ（１３３，１３４）を、観察者１００の眼前に配置する方法として、第１および第２の二焦点レンズ（１３１，１３２）、または、偏光型二焦点レンズ（１３３，１３４）が左右のレンズとして取り付けられたメガネを用意し、観察者１００が、このメガネをかける方法を採用したが、第１および第２の二焦点レンズ（１３１，１３２）を、観察者１００の眼前に配置する方法は、これに限定されるものではなく、その他の方法を用いてもよい。
以上、本発明者によってなされた発明を、前記実施の形態に基づき具体的に説明したが、本発明は、前記実施の形態に限定されるものではなく、その要旨を逸脱しない範囲において種々変更可能であることは勿論である。
【００３５】
【発明の効果】
本願において開示される発明のうち代表的なものによって得られる効果を簡単に説明すれば、下記の通りである。
本発明の三次元表示装置によれば、立体視の生理的要因間での矛盾を抑制し、かつ、多人数の人が同時に三次元立体像を観察することが可能となる。
【図面の簡単な説明】
【図１】本発明の基本となる三次元表示装置の基本構成を示す図である。
【図２】従来の二眼式立体表示装置における三次元立体像の奥行き位置と、右目用および左目用の視差像におけ表示装置上の位置を示す模式図である。
【図３】ＤＦＤ方式の三次元表示装置の概略構成を示す図である。
【図４】ＤＦＤ方式の三次元表示装置において、各表示面に表示する２Ｄ化像の生成方法を説明するための図である。
【図５】ＤＦＤ方式の三次元表示装置の表示原理を説明するための図である。
【図６】ＤＦＤ方式の三次元表示装置の表示原理を説明するための図である。
【図７】ＤＦＤ方式の三次元表示装置の表示原理を説明するための図である。
【図８】ＤＦＤ方式の三次元表示装置の表示原理を説明するための図である。
【図９】本発明の実施の形態の三次元表示装置において、第１および第２の二焦点レンズによる結像面を示す図である。
【図１０】本発明の実施の形態の三次元表示装置の一例の概略構成を示す図である。
【図１１】本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
【図１２】図１１、図１６に示す偏光型二焦点レンズの一例の概略構成を示す図である。
【図１３】本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
【図１４】本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
【図１５】図１４に示す表示装置の一例を示す図である。
【図１６】本発明の実施の形態の三次元表示装置の他の例の概略構成を示す図である。
【図１７】従来の二眼式立体表示装置の一例を示す図である。
【符号の説明】
１０…表示装置の表示面、１１…右目用の視差像および左目用の視差像による三次元立体像の奥行き位置、２１…観察者が実際に観察する右目用の視差像の表示装置の表示面の位置、２２…観察者が実際に観察する左目用の視差像の表示装置の表示面の位置、１００，６０７…観察者、１０１，１０２…表示面、１０３…光学系、１０４，６０１…三次元物体、１０５，１０６…２Ｄ化像、１３１，１３２…二焦点レンズ、１３３，１３４…偏光型二焦点レンズ、１３５，１３６，１３７…偏光切替装置、１４１，１４２…シャッタ装置、１５１〜１５４…直線偏光子、２００…表示装置、２１０…同期装置、１６１，１６２…プロジェクタ型二次元表示装置、１６３…スクリーン、３０１…固定焦点レンズ、３０２…複屈折領域、３０３…配向膜、６０２，６０３…カメラ、６０４…映像信号変換装置、６０５…ＣＲＴ表示装置、６０６…液晶シャッタ眼鏡、１０２１，１０２２…結像面。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a three-dimensional display device, and more particularly to a three-dimensional display device that suppresses contradiction among physiological factors of stereoscopic vision and allows a large number of people to observe a three-dimensional stereoscopic image at the same time.
[0002]
[Prior art]
As a device for displaying a three-dimensional stereoscopic image, a twin-lens stereoscopic display device is known (see, for example, Patent Literature).
FIG. 17 is a diagram showing an example of a conventional binocular stereoscopic display device. The binocular stereoscopic display device shown in FIG. 17 is a liquid crystal shutter glasses method described in FIG. 27 of the aforementioned patent document. 3D display device.
Hereinafter, the principle of the liquid crystal shutter glasses method will be described.
In this liquid crystal shutter glasses method, a camera (602, 603) photographs a three-dimensional object 601 from different directions, and generates an image (parallax image) obtained by photographing the three-dimensional object 601 from different directions.
Images taken by the cameras (602, 603) are combined by a video signal conversion device 604 into one video signal and input to a two-dimensional display device (for example, a CRT display device) 605. The observer 607 observes the image of the two-dimensional display device 605 with the liquid crystal shutter glasses 606.
Here, when the two-dimensional display device 605 displays the image of the camera 603, the liquid crystal shutter glasses 606 are set to the non-transmissive state on the left side and the transmissive state on the right side, and the image of the camera 602 is displayed on the two-dimensional display device 605. Is displayed, the left side of the liquid crystal shutter glasses 606 is transmissive and the right side is non-transmissive.
When the operation is switched at high speed, it feels like a parallax image is visible to both eyes due to the afterimage effect of the eyes. Accordingly, stereoscopic viewing with binocular parallax is possible.
[0003]
The prior art document information related to the invention of the present application includes the following.
[Patent Literature]
Japanese Patent No. 3022558
[Non-patent literature]
"Liquid Crystal / Fundamentals", "Liquid Crystal / Applications" (Okano, Kobayashi, Ed.)
[0004]
[Problems to be solved by the invention]
However, the liquid crystal shutter glasses method shown in FIG. 17 has a large contradiction between binocular parallax, convergence, and focus adjustment among the physiological factors of stereoscopic vision.
In other words, the binocular parallax and the convergence are almost satisfactory in the liquid crystal shutter glasses method, but there is a problem that eye strain occurs due to this contradiction because the focus surface is on the display surface.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to suppress contradiction between physiological factors of stereoscopic vision, and a large number of people can simultaneously perform tertiary. An object of the present invention is to provide a three-dimensional display device capable of observing an original stereoscopic image.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
[0005]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
That is, the present invention is provided in front of the right eye of the observer, a display device that displays a parallax image for the right eye and a parallax image for the left eye, and the focal lengths are the first focal length and the second focal length. A first bifocal lens that is switchable to the left eye of the observer, a second bifocal lens that can switch a focal length between a third focal length and a third focal length, The focal length of the first bifocal lens is switched between the first focal length and the second focal length, and the focal length of the second bifocal lens is changed between the third focal length and the fourth focal length. A three-dimensional display device comprising: a synchronization device that switches to the first synchronization distance, wherein the synchronization device is displayed on the display device when the focal length of the first bifocal lens is switched to the first focal length. The brightness of the parallax image for the right eye and the focal length of the first bifocal lens are set to the second When switching to a point distance, the luminance of the parallax image for the right eye displayed on the display device changes according to the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye And the luminance of the parallax image for the left eye displayed on the display device when the focal length of the second bifocal lens is switched to the third focal length, and the second bifocal lens When the focal length of the left eye is switched to the fourth focal length, the luminance of the parallax image for the left eye displayed on the display device is changed to a three-dimensional stereoscopic image based on the parallax image for the right eye and the parallax image for the left eye. It is changed according to the depth position.
[0006]
In the present invention, a first shutter means provided in front of the right eye of the observer and a second shutter provided in front of the eye of the left eye of the observer are provided, and the display device is for the right eye. The parallax image and the parallax image for the left eye are alternately displayed, and the synchronization device transmits the first shutter unit in a transmissive state when the display device displays the parallax image for the right eye, and the second The shutter means is made non-transmissive, and the focal length of the first bifocal lens is switched in time division between the first focal length and the second focal length, and the display device performs parallax for the left eye. When displaying an image, the first shutter unit is set to a non-transmissive state, the second shutter unit is set to a transmissive state, and the focal length of the second bifocal lens is set to a third focal length and a fourth focal length. Switch to the focal length of in time division.
[0007]
In the present invention, the polarization switching device disposed on the observer side of the display device, the first shutter means provided in front of the right eye of the observer, and the eye in front of the left eye of the observer. A second shutter, and the first and second bifocal lenses are polarization bifocal lenses, and the display device alternately produces the right-eye parallax image and the left-eye parallax image. The synchronizing device sets the first shutter means to the transmissive state and the second shutter means to the non-transmissive state when the display device displays the parallax image for the right eye, and The switching device is controlled to switch the polarization direction of the parallax image output from the polarization switching device between the first direction and the second direction in a time-sharing manner, and the display device displays the parallax image for the left eye When the first shutter means The non-transmission state, the second shutter means is set to the transmission state, the polarization switching device is controlled, and the polarization directions of the parallax images output from the polarization switching device are changed to the first direction and the second direction. Switch in time division.
[0008]
In the present invention, the polarization switching device disposed on the viewer side of the display device and the right eye of the viewer are provided in front of the eyes, and the polarization direction of the light passes through the first polarization direction. Is provided in front of the eyes of the left eye of the observer, the light passing through the second polarization direction, and the polarization direction is the first polarization direction. Second means for blocking the light, and the display device alternately displays the parallax image for the right eye and the parallax image for the left eye, and the synchronization device controls the polarization switch. When the display device displays the parallax image for the right eye, the polarization direction of the parallax image output from the polarization switching device is switched to the first polarization direction, and the focal length of the first bifocal lens is changed. Switch to the first focal length and the second focal length in a time-sharing manner. When the display device displays the parallax image for the left eye, the polarization direction of the parallax image output from the polarization switching device is switched to the second polarization direction, and the focal length of the second bifocal lens is changed to a third distance. Are switched in a time-division manner to the fourth focal length and the fourth focal length.
[0009]
In the present invention, the first means is provided in front of the right eye of the observer, and transmits light having a polarization direction of a first polarization direction and blocks light having a polarization direction of a second polarization direction; A second means provided in front of the eye of the left eye of the observer, which transmits light having a polarization direction of a second polarization direction and blocks light having a polarization direction of the first polarization direction; , Simultaneously displaying the parallax image for the right eye whose polarization direction is the first polarization direction and the parallax image for the left eye whose polarization direction is the second polarization direction, and the synchronization device The focal length of the bifocal lens is switched in time division between the first focal length and the second focal length, and the focal length of the second bifocal lens is switched between the third focal length and the fourth focal length. Switch by dividing.
[0010]
In the present invention, the first polarization switching device provided between the first bifocal lens and the display device, and the second provided between the second bifocal lens and the display device. The polarization switching device is provided between the first polarization switching device and the display device, and transmits light having a polarization direction of the first polarization direction and blocks light having a polarization direction of the second polarization direction. Provided between the first means, the second polarization switching device, and the display device, the light whose polarization direction is the second polarization direction is allowed to pass, and the light whose polarization direction is the first polarization direction is transmitted. And the first and second bifocal lenses are polarization bifocal lenses, and the display device has a parallax for the right eye whose polarization direction is the first polarization direction. Simultaneously displaying the image and the parallax image for the left eye whose polarization direction is the second polarization direction. The synchronization device controls the first and second polarization switching devices, and changes the polarization directions of the parallax images output from the first and second polarization switching devices to the first polarization direction and the second polarization direction. Switch in time division.
In the present invention, the eyeglasses worn by the observer are provided, and the eyeglasses have the first and second variable focus lenses as left and right lenses.
[0011]
According to the present invention, the first bifocal lens is placed in front of the right eye of the observer by a method such as wearing glasses with the first and second bifocal lenses attached as left and right lenses, A second bifocal lens is arranged in front of the left eye of the observer, and the principle of a DFD (Depth Fused 3-D) type three-dimensional display device described in the above-mentioned patent document is applied to the right eye. And the observer is perceived so that the focus plane of the parallax image for the left eye is in the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye. It is possible to reduce eyestrain and the like, which has been a problem with stereoscopic displays.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.
FIG. 1 is a diagram showing a schematic configuration of a three-dimensional display device which is the basis of the present invention.
The three-dimensional display device illustrated in FIG. 1 includes a display device 200, a first bifocal lens 131 disposed in front of the right eye of the observer 100, and a second second lens disposed in front of the left eye of the observer 100. A focus lens 132 and a synchronization device 210 are provided. Here, the display device 200 displays a right-eye parallax image (two-dimensional image) and a left-eye parallax image.
Here, the first bifocal lens 131 can switch the focal length between the first focal length and the second focal length, and the second bifocal lens 132 changes the focal length to the first focal length. It is possible to switch between 3 focal lengths and 4th focal lengths.
For example, as shown in FIG. 1, the first bifocal lens 131 and the second bifocal lens 132 are attached as the left and right lenses of the glasses, and the observer 100 puts the glasses on the display device 200. Observe.
[0013]
FIG. 2 is a schematic diagram showing the depth position of a three-dimensional stereoscopic image in a conventional binocular stereoscopic display device, and positions on the display device in parallax images for right and left eyes. A display surface 11 of the display device 200 represents the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye.
In FIG. 2, the display surface 10 of the display device 200 on which the observer 100 actually observes the pixel at the position x0 in the depth position 11 of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye. The position is 21 in the parallax image for the right eye and 22 in the parallax image for the left eye.
Thus, in the conventional binocular stereoscopic display device, binocular parallax and convergence are almost satisfied among the physiological factors of stereoscopic vision, but the focus plane of the parallax image for the right eye and the left eye is the display surface. Therefore, this contradiction has the problem of causing eye strain and the like.
In FIG. 2, when dR and dL are parallax amounts, the position x0, the depth position z0 of the position x0, the viewing distance (distance between the observer and the display surface of the display device) D, and the binocular distance of the observer There is a relationship of the following formulas (1) and (2) with E.
[Expression 1]
dL = z0 × (E / 2−x0) / (D−z0) (1)
dR = z0 × (E / 2 + x0) / (D−z0) (2)
[0014]
In order to solve this problem, the three-dimensional display device according to the present embodiment applies the principle of the DFD (Depth Fused 3-D) method three-dimensional display device described in the aforementioned patent document, Conventional binocular stereoscopic display by letting the viewer perceive that the focus plane of the parallax image for the left and right eyes is in the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye It reduces eye strain and other problems that have been a problem with the device.
Hereinafter, the three-dimensional display device according to the present embodiment will be described. First, the principle of a DFD (Depth Fused 3-D) type three-dimensional display device will be described.
FIG. 3 is a diagram showing a schematic configuration of a DFD type three-dimensional display device, which is the three-dimensional display device shown in FIG. 1 in the aforementioned patent document.
In the three-dimensional display device of the DFD system, a plurality of display surfaces, for example, display surfaces (101, 102) (the display surface 101 is closer to the viewer 100 than the display surface 102) are set on the front surface of the viewer 100. In order to display a plurality of two-dimensional images on the display surfaces (101, 102), an optical system 103 is constructed using a two-dimensional display device and various optical elements.
[0015]
Hereinafter, the display principle of the DFD type three-dimensional display device will be described with reference to FIGS.
As shown in FIG. 4, an image (hereinafter referred to as a “2D image”) that is obtained by projecting a three-dimensional object 104 to be presented to the viewer 100 from the viewing direction of both eyes of the viewer 100 onto the display surface (101, 102). Is generated) (105, 106).
As a method for generating the 2D image, for example, a method using a two-dimensional image obtained by photographing the object 104 with a camera from the line-of-sight direction, a method of combining from a plurality of two-dimensional images taken from different directions, or a computer graphic There are various methods such as a synthesis technique based on the above and a method using modeling.
Then, as shown in FIG. 3, the 2D image (105, 106) is viewed from one point on the line connecting the right eye and the left eye of the observer 100 on both the display surface 101 and the display surface 102, respectively. Display to overlap.
This can be achieved, for example, by controlling the arrangement of the center position and the gravity center position of each 2D image (105, 106) and the enlargement / reduction of each image.
[0016]
An important point of the DFD type three-dimensional display device is that the luminance of each of the 2D images (105, 106) on the device having the above-described configuration is kept constant as viewed from the observer 100. The three-dimensional object 104 is changed corresponding to the depth position.
An example of how to change is described below. Here, since it is a black and white drawing, the higher luminance is shown darkly in the following drawings for easy understanding.
For example, when the three-dimensional object 104 is on the display surface 101, as shown in FIG. 5, the luminance of the 2D image 105 above is made equal to the luminance of the three-dimensional object 104 and 2D on the display surface 102 is displayed. The luminance of the converted image 106 is zero.
Next, for example, when the three-dimensional object 104 is slightly away from the viewer 100 and is slightly closer to the display surface 102 than the display surface 101, the brightness of the 2D image 105 is increased as shown in FIG. Slightly lower the brightness of the 2D image 106 slightly.
[0017]
Furthermore, for example, when the three-dimensional object 104 is further away from the viewer 100 and is further away from the display surface 101 toward the display surface 102, the brightness of the 2D image 105 is further increased as shown in FIG. The brightness of the 2D image 106 is further increased.
Finally, for example, when the three-dimensional object 104 is on the display surface 102, the luminance of the 2D image 106 on the display surface 102 is made equal to the luminance of the three-dimensional object 104 as shown in FIG. The brightness of the 2D image 105 is zero.
By displaying in this way, even if the 2D image (105, 106) is displayed due to the physiological or psychological factors or illusions of the observer (person) 100, it is as if the observer 100 It feels as if the three-dimensional object 104 is located in the middle of the display surfaces (101, 102).
That is, for example, when a 2D image (105, 106) having substantially equal luminance is displayed on the display surface (101, 102), the three-dimensional object 104 is located near the middle of the depth position of the display surface (101, 102). It feels like there is.
[0018]
As shown in FIG. 9, in the three-dimensional display device according to the present embodiment, the synchronization device 210 sets the focal length of the first bifocal lens 131 arranged in front of the right eye of the observer 100 to 2 in a time division manner. The two-dimensional image displayed on the display device 200 is imaged on the imaging surface 1021 and the imaging surface 1022 by changing in stages.
Then, when the two-dimensional image displayed on the display device 200 is formed on the imaging surface 1021 by the synchronization device 210, the first parallax image is displayed on the display device 200 and is displayed on the display device 200. When the two-dimensional image is formed on the imaging surface 1022, the second parallax image is displayed on the display device 200. This operation is performed within the afterimage time of the human eye.
Here, the first parallax image and the second parallax image are obtained for each pixel of the right-eye parallax image, and the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye (see FIG. 2). 11) is a parallax image in which luminance is distributed according to (11).
In this case, the depth position of the position x0 can be obtained by the above-described equations (1) and (2).
[0019]
As described above, an important point of the DFD type three-dimensional display device is that the luminance of each of the 2D images (105, 106) is kept constant while maintaining the overall luminance as viewed from the observer 100. It is to change corresponding to the depth position of the object 104.
Therefore, as described above, as the first parallax image and the second parallax image, for each pixel of the parallax image for the right eye, the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye In accordance with (11 in FIG. 2), the parallax image in which the luminance is distributed is displayed on the display device 200 (that is, the imaging planes (1021, 1022)), so that the observer 100 receives the parallax image for the right eye. The focus plane is perceived as being at the depth position of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye.
That is, as the first parallax image and the second parallax image, an image obtained by dividing the luminance of the parallax image for the right eye on a one-to-one basis is displayed on the display device 200, so that the viewer 100 can have an image plane (1021). , 1022), it seems that there is a focus plane of the parallax image for the right eye near the middle.
[0020]
Here, by changing the luminance division ratio of the parallax image for the right eye, the focus plane of the parallax image for the right eye felt by the viewer 100 is changed between the imaging plane 1021 and the imaging plane 1022. Can do.
The left-eye parallax image is also displayed in the same manner as the right-eye parallax image.
As a result, the viewer 100 feels that the focus planes of the right-eye and left-eye parallax images are at the depth position of the three-dimensional stereoscopic image of the right-eye parallax image and the left-eye parallax image. In the 3D display device according to the embodiment, it is possible to reduce eyestrain and the like, which has been a problem in the conventional binocular stereoscopic display device. An image can be observed.
[0021]
Hereinafter, a three-dimensional display device according to an embodiment of the present invention will be described.
FIG. 10 is a diagram showing a schematic configuration of an example of the three-dimensional display device according to the embodiment of the present invention.
In the three-dimensional display device shown in FIG. 10, the first shutter device 141 is disposed on the display device side of the first bifocal lens 131, and the second shutter is disposed on the display device side of the second bifocal lens 132. It differs from the three-dimensional display device shown in FIG. 1 in that the device 142 is arranged.
In the three-dimensional display device illustrated in FIG. 10, the display device 200 alternately displays a parallax image for the right eye and a parallax image for the left eye, and accordingly, the synchronization device 210 includes a parallax image for the right eye. When the first shutter device 141 is in the transmissive state, the second shutter device 142 is in the non-transmissive state, and when the display device 200 displays the parallax image for the left eye, The device 142 is in a transmissive state, and the first shutter device 141 is in a non-transmissive state.
[0022]
In addition, when the display device 200 displays the right-eye parallax image, the synchronization device 210 changes the focal length of the first bifocal lens 131 in two stages in a time-division manner, and the first parallax image and the first parallax image. As the parallax image of 2, the luminance is distributed for each pixel of the parallax image for the right eye according to the depth position (11 in FIG. 2) of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye. The parallax image is displayed on the display device 200 (that is, on the imaging planes (1021, 1022)).
In addition, when the display device 200 displays a parallax image for the left eye, the synchronization device 210 changes the focal length of the second bifocal lens 132 in two stages in a time-division manner, and the first parallax image and the first parallax image. As the parallax image of 2, the luminance is distributed for each pixel of the parallax image for the left eye according to the depth position (11 in FIG. 2) of the right-eye parallax image and the left-eye parallax image. The parallax image is displayed on the display device 200 (that is, on the imaging planes (1021, 1022)).
In the three-dimensional display device shown in FIG. 10, the first and second shutter devices (141, 142) may be installed on the viewer side of the first and second bifocal lenses (131, 132). Good.
[0023]
FIG. 11 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
In the three-dimensional display device shown in FIG. 11, a polarization switching device 135 is disposed on the viewer side of the display device 200, and the first bifocal lens 131 and the second bifocal lens 132 are polarized bifocal lenses. (133, 134) is different from the three-dimensional display device shown in FIG.
The polarization type bifocal lens (133, 134) is a lens whose focal length changes in two steps depending on the polarization direction of incident light. As shown in FIG. The two-dimensional image displayed on 200 can be imaged on the first imaging surface 1021 and the second imaging surface 1022.
In the three-dimensional display device illustrated in FIG. 11, the display device 200 alternately displays the parallax image for the right eye and the parallax image for the left eye, and the synchronization device 210 displays the parallax image for the right eye. In addition, the first shutter device 141 is in a transmissive state, the second shutter device 142 is in a non-transmissive state, and when the display device 200 displays a parallax image for the left eye, the second shutter device 142 is transmissive. In this state, the first shutter device 141 is set to a non-transmissive state.
[0024]
The synchronization device 210 controls the polarization switching device 135 when the display device 200 displays the right-eye parallax image, and sets the polarization direction of the right-eye parallax image output from the polarization switching device 135 to the first direction. The polarization direction and the second polarization direction are switched in a time division manner to change the focal length of the polarizing bifocal lens 133 in two stages in a time division manner, and the right eye is converted into a first parallax image and a second parallax image. For each pixel of the parallax image for use, a parallax image in which the luminance is distributed to the display device 200 according to the depth position (11 in FIG. 2) of the parallax image for the right eye and the parallax image for the left eye. (I.e., on the image planes (1021, 1022)).
Further, the synchronization device 210 controls the polarization switching device 135 when the display device 200 displays the left-eye parallax image, and sets the polarization direction of the right-eye parallax image output from the polarization switching device 135 to the first one. The polarization direction and the second polarization direction are switched in a time division manner to change the focal length of the polarization type bifocal lens 134 in two stages in a time division manner, and the left eye is converted into a first parallax image and a second parallax image. For each pixel of the parallax image for use, a parallax image in which the luminance is distributed to the display device 200 according to the depth position (11 in FIG. 2) of the parallax image for the right eye and the parallax image for the left eye. (I.e., on the image planes (1021, 1022)).
In the three-dimensional display device shown in FIG. 11, the first and second shutter devices (141, 142) may be installed on the observer side of the polarization type bifocal lens (133, 134).
[0025]
FIG. 12 is a diagram showing a schematic configuration of an example of the polarization type bifocal lens (133, 134) shown in FIG.
The polarization type bifocal lens shown in FIG. 12 includes a fixed focus lens 301 and a birefringent region 302 as shown in FIGS.
Here, the fixed focus lens 301 is, for example, a glass or plastic convex lens shown in FIG. 12B, a glass or plastic concave lens shown in FIG. 12A, or a glass or plastic convex lens, The lens system is configured by a combination of a concave lens and a prism, or a mirror system by a combination of a convex lens, a concave lens, and a prism made of glass or plastic.
In addition, the birefringent region 302 is formed of a medium having birefringent properties made of, for example, liquid crystal or PLZT.
[0026]
Here, the refractive index of the fixed focus lens 301 is n1, and the refractive indexes of the birefringent region 302 in the first polarization direction and the second polarization direction of incident light are n21 and n22, respectively.
For example, when light is incident from the birefringent region 302, the light travels while feeling the refractive indexes n21 and n22 according to the polarization direction of the incident light, and then comes into contact with the fixed focus lens 301 having the refractive index n1.
Therefore, the emitted light is imaged at different positions according to the polarization state of the incident light. That is, it operates as a bifocal lens whose focal length differs depending on the polarization direction.
On the other hand, even when the light is incident from the fixed focus lens 301 side, the image is separated and formed on the two image planes by the refractive index corresponding to the intrinsic polarization direction.
As shown in FIG. 12, when the birefringent region 302 is a liquid crystal, by adding an alignment film 303, in-plane uniform separation can be obtained for light incident from the birefringent region 302 side.
[0027]
Further, in the polarization type bifocal lens shown in FIG. 12, even when the fixed focus lens 301 is not provided, when one or both surfaces of the birefringent region 302 have a lens shape or a prism shape as shown in FIG. Has a similar effect.
Furthermore, as a medium having birefringence, the liquid crystal is useful because of its large refractive index anisotropy, and as its type, in addition to the usual nematic liquid crystal, for example, polymer dispersed liquid crystal, holographic polymer dispersed Type liquid crystal, polymer liquid crystal, smectic liquid crystal, ferroelectric liquid crystal, and polymer stabilized ferroelectric liquid crystal.
Furthermore, it is clear that birefringence can be obtained by forming the main axis of the polymer material in alignment with other than the liquid crystal.
As the polarization switching device 135 of the present embodiment, for example, a device using a medium (for example, liquid crystal or PLZT) whose birefringence can be changed by an electric field or voltage is well known. Many types of liquid crystal devices are described in, for example, the aforementioned non-patent literature.
[0028]
FIG. 13 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
In the three-dimensional display device illustrated in FIG. 13, the polarization switching device 135 is disposed on the viewer side of the display device 200, and the first linear polarizer 151 is disposed on the display device side of the first bifocal lens 131. The second linear polarizer 152 is different from the three-dimensional display device shown in FIG. 1 in that the second linear polarizer 152 is arranged on the display device side of the second bifocal lens 132.
In the three-dimensional display device shown in FIG. 13, the display device 200 alternately displays the parallax image for the right eye and the parallax image for the left eye, and accordingly, the synchronization device 210 controls the polarization switching device 135 to control the polarization. The polarization direction of the parallax image for the right eye output from the switching device 135 is switched to the first polarization direction, and the polarization direction of the parallax image for the left eye output from the polarization switching device 135 is switched to the second polarization direction.
In addition, the linear polarizer 151 has a polarization direction of the first direction, passes light having a polarization direction of the first polarization direction, and blocks light having a polarization direction of the second polarization direction.
Similarly, the linear polarizer 152 has a polarization direction of the second direction, passes light having a polarization direction of the second polarization direction, and blocks light having a polarization direction of the first polarization direction.
[0029]
In addition, when the display device 200 displays the right-eye parallax image, the synchronization device 210 changes the focal length of the first bifocal lens 131 in two stages in a time-division manner, and the first parallax image and the first parallax image. As the parallax image of 2, the luminance is distributed for each pixel of the parallax image for the right eye according to the depth position (11 in FIG. 2) of the three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye. The parallax image is displayed on the display device 200 (that is, on the imaging planes (1021, 1022)).
In addition, when the display device 200 displays the parallax image for the left eye, the synchronization device 210 changes the focal length of the second bifocal lens 132 in two stages in a time-division manner, As the parallax image of 2, the luminance is distributed for each pixel of the parallax image for the left eye according to the depth position (11 in FIG. 2) of the right-eye parallax image and the left-eye parallax image. The parallax image is displayed on the display device 200 (that is, on the imaging planes (1021, 1022)).
In the three-dimensional display device shown in FIG. 13, the first and second linear polarizers (151 and 152) are installed on the viewer side of the first and second bifocal lenses (131 and 132). Also good.
In the three-dimensional display devices shown in FIGS. 10, 11, and 13, the display device 200 includes, for example, a CRT, a liquid crystal display, an LED display, an EL display, a plasma display, an FED display, a projection display, and a line drawing type. A display or the like is used.
[0030]
FIG. 14 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
In the three-dimensional display device shown in FIG. 14, the display device 200 simultaneously displays a parallax image for the right eye whose polarization direction is the first direction and a parallax image for the left eye whose polarization direction is the second direction. The first linear polarizer 151 is disposed on the display device side of the first bifocal lens 131, and the second linear polarizer 152 is disposed on the display device side of the second bifocal lens 132. It differs from the three-dimensional display device shown in FIG.
An example of the display device 200 shown in FIG. 14 is shown in FIG.
A display device 200 shown in FIG. 15 includes first and second projector-type two-dimensional display devices (for example, CRT type, LCD type, ILV type, DMD type, etc.) (161, 162) and a screen 163. The
Here, the screen 163 may be either a transmissive screen or a reflective screen.
[0031]
When the screen 163 is a transmissive screen, the first and second projector-type two-dimensional display devices (161, 162) are arranged on the opposite side of the screen 163 from the observer, and the screen 163 is a reflective screen. In this case, the first and second projector-type two-dimensional display devices (161, 162) are arranged on the viewer side of the screen 163.
The first projector-type two-dimensional display device 161 includes a third linear polarizer 153 whose polarization direction is the first direction, and displays a parallax image whose polarization direction is the first direction as a parallax image for the right eye on the screen 163. Project to.
The second projector type two-dimensional display device 162 includes a fourth linear polarizer 154 whose polarization direction is the second direction, and displays a parallax image whose polarization direction is the second direction as the parallax image for the left eye on the screen 163. Project to.
In addition, the linear polarizer 151 has a polarization direction of the first direction, passes light having a polarization direction of the first polarization direction, and blocks light having a polarization direction of the second polarization direction.
Similarly, the linear polarizer 152 has a polarization direction of the second direction, passes light having a polarization direction of the second polarization direction, and blocks light having a polarization direction of the first polarization direction.
[0032]
In addition, the synchronization device 210 changes the focal length of the first bifocal lens 131 in two stages in a time-sharing manner, and for each pixel of the parallax image for the right eye as the first parallax image and the second parallax image. In addition, the parallax image in which the luminance is distributed according to the depth position (11 in FIG. 2) of the right-eye parallax image and the left-eye parallax image (11 in FIG. 2) is displayed on the display device 200 (that is, the imaging plane (1021). , 1022)).
In addition, the synchronization device 210 changes the focal length of the second bifocal lens 132 in two stages in a time-sharing manner, and for each pixel of the parallax image for the left eye as the first parallax image and the second parallax image. In addition, the parallax image in which the luminance is distributed according to the depth position (11 in FIG. 2) of the right-eye parallax image and the left-eye parallax image (11 in FIG. 2) is displayed on the display device 200 (that is, the imaging plane (1021). , 1022)).
In the three-dimensional display device shown in FIG. 14, the first and second linear polarizers (151 and 152) are installed on the viewer side of the first and second bifocal lenses (131 and 132). Also good.
[0033]
FIG. 16 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
In the three-dimensional display device shown in FIG. 16, the first bifocal lens 131 and the second bifocal lens 132 are polarization bifocal lenses (133, 134), and the polarization bifocal lens 133 and linear polarizer. 151, the first polarization switching device 136 is disposed between the polarization bifocal lens 134 and the second linear polarizer 152, and the second polarization switching device 137 is disposed between the polarization bifocal lens 134 and the second linear polarizer 152. 14 is different from the three-dimensional display device shown in FIG.
Also in the three-dimensional display device shown in FIG. 16, the display device 200 simultaneously displays a parallax image for the right eye whose polarization direction is the first direction and a parallax image for the left eye whose polarization direction is the second direction.
The synchronization device 210 controls the first polarization switching device 136 and the second polarization switching device 137, and the polarization of the parallax image output from the first and second polarization switching devices (136, 137). The direction is switched in a time-sharing manner between the first polarization direction and the second polarization direction, and each of the right-eye and left-eye parallax images is used as a first parallax image for the right eye and a left parallax image. For each pixel, the parallax image in which the luminance is distributed according to the depth position (11 in FIG. 2) of the parallax image for the right eye and the parallax image for the left eye is displayed on the display device 200 (that is, the imaging plane). (1021, 1022). In the three-dimensional display device shown in FIG. 16, the one shown in FIG. 12 can be used as the polarization type bifocal lens (133, 134), and the display device shown in FIG.
[0034]
In the above description, the first and second bifocal lenses (131, 132) or the polarization bifocal lenses (133, 134) are arranged in front of the observer 100 as the first and second methods. The second bifocal lens (131, 132) or the polarized bifocal lens (133, 134) is prepared as a left and right lens, and the observer 100 adopts a method of wearing this spectacle. However, the method of placing the first and second bifocal lenses (131, 132) in front of the eyes of the observer 100 is not limited to this, and other methods may be used.
Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course.
[0035]
【The invention's effect】
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
According to the three-dimensional display device of the present invention, contradiction among physiological factors of stereoscopic vision can be suppressed, and a large number of people can simultaneously observe a three-dimensional stereoscopic image.
[Brief description of the drawings]
FIG. 1 is a diagram showing a basic configuration of a three-dimensional display device as a basis of the present invention.
FIG. 2 is a schematic diagram illustrating a depth position of a three-dimensional stereoscopic image in a conventional binocular stereoscopic display device, and positions on the display device in right-eye and left-eye parallax images.
FIG. 3 is a diagram illustrating a schematic configuration of a DFD type three-dimensional display device;
FIG. 4 is a diagram for explaining a method for generating a 2D image to be displayed on each display surface in a DFD three-dimensional display device.
FIG. 5 is a diagram for explaining a display principle of a DFD type three-dimensional display device;
FIG. 6 is a diagram for explaining a display principle of a DFD type three-dimensional display device;
FIG. 7 is a diagram for explaining a display principle of a DFD type three-dimensional display device;
FIG. 8 is a diagram for explaining a display principle of a DFD type three-dimensional display device;
FIG. 9 is a diagram showing an image plane formed by first and second bifocal lenses in the three-dimensional display device according to the embodiment of the present invention.
FIG. 10 is a diagram illustrating a schematic configuration of an example of a three-dimensional display device according to an embodiment of the present invention.
FIG. 11 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
12 is a diagram showing a schematic configuration of an example of the polarizing bifocal lens shown in FIGS. 11 and 16. FIG.
FIG. 13 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
FIG. 14 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
15 is a diagram showing an example of the display device shown in FIG.
FIG. 16 is a diagram showing a schematic configuration of another example of the three-dimensional display device according to the embodiment of the present invention.
FIG. 17 is a diagram illustrating an example of a conventional binocular stereoscopic display device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Display surface of display apparatus, 11 ... Depth position of three-dimensional stereoscopic image by parallax image for right eye and parallax image for left eye, 21 ... Display surface of parallax image for right eye that observer actually observes 22: Position of display surface of display device for parallax image for left eye actually observed by observer, 100, 607 ... Observer, 101, 102 ... Display surface, 103 ... Optical system, 104, 601 ... Tertiary Original object, 105, 106 ... 2D image, 131, 132 ... Bifocal lens, 133, 134 ... Polarization type bifocal lens, 135, 136, 137 ... Polarization switching device, 141, 142 ... Shutter device, 151-154 ... Linear polarizer, 200 ... display device, 210 ... synchronization device, 161 and 162 ... projector type two-dimensional display device, 163 ... screen, 301 ... fixed focus lens, 302 ... birefringence region, 303 ... Alignment films, 602, 603 ... camera, 604 ... video signal converting device, 605 ... CRT display device, 606 ... liquid crystal shutter glasses, 1021, 1022 ... imaging plane.

Claims

A display device that displays a parallax image for the right eye and a parallax image for the left eye;
A first bifocal lens provided in front of the right eye of the observer and capable of switching a focal length between a first focal length and a second focal length;
A second bifocal lens provided in front of the left eye of the observer and capable of switching a focal length between a third focal length and a fourth focal length;
The focal length of the first bifocal lens is switched between a first focal length and a second focal length, and the focal length of the second bifocal lens is changed to a third focal length and a fourth focal length. A three-dimensional display device comprising a synchronization device for switching to
The synchronization device includes a luminance of the parallax image for the right eye displayed on the display device when the focal length of the first bifocal lens is switched to the first focal length, and the first bifocal lens. When the focal length of the right eye is switched to the second focal length, the luminance of the parallax image for the right eye displayed on the display device is expressed as a three-dimensional stereoscopic image by the parallax image for the right eye and the parallax image for the left eye. The brightness of the parallax image for the left eye displayed on the display device when the focal length of the second bifocal lens is changed to a third focal length is changed according to the depth position, and the second When the focal length of the bifocal lens 2 is switched to the fourth focal length, the luminance of the parallax image for the left eye displayed on the display device is determined by the parallax image for the right eye and the parallax image for the left eye. Changes according to the depth position of the 3D stereoscopic image Three-dimensional display device characterized by to.

First shutter means provided in front of the right eye of the observer;
A second shutter provided in front of the left eye of the observer,
The display device alternately displays the parallax image for the right eye and the parallax image for the left eye,
When the display device displays the right-eye parallax image, the synchronization device sets the first shutter means to the transmissive state and the second shutter means to the non-transmissive state, and The focal length of the focal lens is switched in time division between the first focal length and the second focal length, and when the display device displays the parallax image for the left eye, the first shutter means is not transmitted. 2. The state of claim 1, wherein the second shutter means is in a transmissive state, and the focal length of the second bifocal lens is switched in a time division manner between a third focal length and a fourth focal length. The three-dimensional display device described in 1.

A polarization switching device disposed on the viewer side of the display device;
First shutter means provided in front of the right eye of the observer;
A second shutter provided in front of the left eye of the observer,
The first and second bifocal lenses are polarization bifocal lenses;
The display device alternately displays the parallax image for the right eye and the parallax image for the left eye,
When the display device displays the right-eye parallax image, the synchronization device sets the first shutter means in a transmissive state and the second shutter means in a non-transmissive state, and sets the polarization switching device When the polarization direction of the parallax image output from the polarization switching device is switched in time division between the first direction and the second direction, and when the display device displays the parallax image for the left eye The first shutter means is in a non-transmissive state, the second shutter means is in a transmissive state, the polarization switching device is controlled, and the polarization direction of the parallax image output from the polarization switching device is set to the first The three-dimensional display device according to claim 1, wherein the direction is switched to the second direction in a time division manner.

A polarization switching device disposed on the viewer side of the display device;
A first means that is provided in front of the right eye of the observer and transmits light having a polarization direction of a first polarization direction and blocks light having a polarization direction of a second polarization direction;
Provided in front of the left eye of the observer, and a second means for passing light having a polarization direction of a second polarization direction and blocking light having a polarization direction of the first polarization direction,
The display device alternately displays the parallax image for the right eye and the parallax image for the left eye,
The synchronization device controls the polarization switch, and switches the polarization direction of the parallax image output from the polarization switching device to the first polarization direction when the display device displays the parallax image for the right eye. The focal length of the first bifocal lens is switched in time division between the first focal length and the second focal length, and the polarization switching device when the display device displays the parallax image for the left eye Switching the polarization direction of the parallax image output from the second polarization direction and switching the focal length of the second bifocal lens between a third focal length and a fourth focal length in a time-sharing manner. The three-dimensional display device according to claim 1.

A first means that is provided in front of the right eye of the observer and transmits light having a polarization direction of a first polarization direction and blocks light having a polarization direction of a second polarization direction;
Provided in front of the left eye of the observer, and a second means for passing light having a polarization direction of a second polarization direction and blocking light having a polarization direction of the first polarization direction,
The display device simultaneously displays the parallax image for the right eye whose polarization direction is the first polarization direction and the parallax image for the left eye whose polarization direction is the second polarization direction,
The synchronizer switches the focal length of the first bifocal lens between a first focal length and a second focal length in a time-sharing manner, and the focal length of the second bifocal lens is a third focal length. The three-dimensional display device according to claim 1, wherein the distance and the fourth focal length are switched in a time division manner.

A first polarization switching device provided between the first bifocal lens and the display device;
A second polarization switching device provided between the second bifocal lens and the display device;
A first means provided between the first polarization switching device and the display device, which transmits light having a polarization direction of the first polarization direction and blocks light having a polarization direction of the second polarization direction; ,
A second means provided between the second polarization switching device and the display device, which transmits light having a polarization direction of the second polarization direction and blocks light having a polarization direction of the first polarization direction; With
The first and second bifocal lenses are polarization bifocal lenses;
The display device simultaneously displays the parallax image for the right eye whose polarization direction is the first polarization direction and the parallax image for the left eye whose polarization direction is the second polarization direction,
The synchronization device controls the first and second polarization switching units, and sets the polarization directions of the parallax images output from the first and second polarization switching devices to the first polarization direction and the second polarization direction. The three-dimensional display device according to claim 1, wherein the switching is performed in a time division manner.

Equipped with glasses worn by the observer,
The three-dimensional display device according to claim 1, wherein the glasses include the first and second variable focus lenses as left and right lenses.