JP2004138719A - Two-dimensional scanner and picture display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To excellently correct TV distortion and trapezoidal distortion. <P>SOLUTION: The TV distortion and the trapezoidal distortion are corrected by tilting and shifting the spherical lens 5b of a scanning optical system 5 guiding luminous flux from a two-dimensional deflector 4 to a surface to be scanned 6 and shifting a spherical lens 5c thereof. <P>COPYRIGHT: (C)2004,JPO

Description

【００６９】
ここで
ｚ　−−−−−　ｚ軸に対して平行な面のサグ
ＣＵＸ，ＣＵＹ　−−−−−　それぞれｘとｙの曲率
ＫＸ，ＫＹ−−−−−　それぞれｘとｙの円錐係数で、ＡＳＰ面タイプのＫと同様の方法で離心率を求めます。
ＡＲ，ＢＲ，ＣＲ，ＤＲ　−−−−−　円錐から４次，６次，８次，１０次の変形した回転対称部を表します。
ＡＰ，ＢＰ，ＣＰ，ＤＰ　−−−−−　円錐から４次，６次，８次，１０次の変形した非回転対称部を表します。
【００７０】
本実施例３は、全長は実施例２に対して２．７７倍と画面サイズを大きくした倍率にほぼ等しく、更に偏向器４から第３走査レンズ５ｃまでの距離を４２．００（ｍｍ）として実施例２とほぼ等距離に配置している。これは、全長に対する偏向器４から第３走査レンズ５ｃまでの距離を縮小しており、走査光学系の小型化を図っている。本実施例３において、全長Ｌ＝１７５．８８（ｍｍ）、偏向器４から最も被走査面６の近くに配置された走査レンズ５ｃまでの距離ｄ＝４２．００（ｍｍ）であり、
ｄ／Ｌ＝０．２４
となって、画面サイズが大きいにも係わらず、非常にコンパクトな２次元走査光学系を構成できている。
【００７１】
本実施例３では、第２走査レンズ５ｂを偏向器４へ光源１からの光束が斜入射する側へ５３．７４（ｄｅｇ）チルトさせると共に、斜入射する側へ６．４２（ｍｍ）シフトさせている。更に、第３走査レンズ５ｃを偏向器４へ光源１からの光束が斜入射する側へ２．７６（ｄｅｇ）チルトさせると共に、斜入射する側とは反対側へへ２２．４９（ｍｍ）シフトさせている。
【００７２】
図１０に本実施例３の表示画像（格子）を示し、表８に本実施例３のＴＶディストーションと台形歪みの量を示す。
【００７３】
本実施例３は、ＴＶディストーションは、画像の上辺で０．２３％、下辺で０．３６％、左辺で０．１２％、右辺で０．１２％であり、問題ない程度に小さく、良好に補正されている。また、台形歪みは、左辺、右辺共に０．３８％であり、問題ない程度に小さく、良好に補正されている。
【００７４】
本実施例３のようにチルトされる光学素子に回転非対称非球面（屈折面また透過回折面）を用いることで、より効果的にＴＶディストーションならびに台形歪みを補正することができる。また、本実施例３ではチルト及びシフトさせた透過型光学素子は２つとしたがこれに限ったものではなく、例えば３つ以上の透過型光学素子をチルト及び／又はシフトさせても本発明の効果を十分に得ることができる。
【００７５】
（実施例４）
図１１は、本発明の実施例４における２次元走査装置の垂直断面図である。
【００７６】
本実施例４の実施例１との相違点は、１次元方向に偏向可能な１次元偏向器を２つ用いて２次元偏向手段を構成している点である。
【００７７】
本実施例４の２つの偏向器は双方とも、反射面が１つのトーションバーによって筐体に支持されたものであり、図２中の反射面４ａと第１のトーションバー４ｂ及び第１の筐体４ｃから構成される。
【００７８】
光源１から発せられた発散光束は、集光レンズ２によって収束光束に変換され、開口絞り３にて光束幅を制限される。偏向器４は垂直方向へ偏向可能な第１の１次元偏向器４１と水平方向に偏向可能な第２の１次元偏向器４２とで構成されており、光源１からの光束は第１の偏向器４１により垂直方向に偏向され、第２の偏向器４２により水平方向に偏向され、これにより２次元方向に偏向される。偏向器４により偏向された光束は３枚の走査レンズから成る走査光学系５により被走査面６上に光スポットとして結像される。
【００７９】
表９に本実施例４における走査光学系の構成を表すレンズデータを示す。
【００８０】
本実施例４の走査光学系５も３枚の走査レンズから構成され、偏向器４側から順に第１走査レンズ５ａ、第２走査レンズ５ｂ、第３走査レンズ５ｃとしたとき、第１走査レンズ５ａは偏向器４側に凹面を向けた負の光学液パワーを有するメニスカスレンズであり、第２走査レンズ５ｂは偏向器４側に凹面を向けた正の光学的パワーを有するメニスカスレンズであり且つ両面をアナモフィック面で構成しており、第３走査レンズ５ｃは正の光学的パワーを有する両凸レンズである。
【００８１】
本実施例４では、光源１からの光束を、まずは垂直方向に偏向可能な第１の偏向器４１に入射させ、次に水平方向に偏向可能な第２の偏向器４２へ入射させている。このとき、光源１からの光束は垂直断面内において第１の偏向器４１に入射させている。第１の偏向器４１の回転中心軸は水平断面内にあり、入射光束と偏向器の反射面の回転中心軸とが別の断面に存在する。しかし、第２の偏向器４２の回転中心軸は入射光束同様垂直断面内に存在するので、第１の偏向器４１で偏向された光束は第２の偏向器４２に斜入射することとなる。これによって、ＴＶディストーションと台形歪みが発生し問題となる。
【００８２】
そこで、本実施例４では、垂直断面内において第２走査レンズ５ｂを、第２の偏向器４２へ光源１からの光束が斜入射する側（図１１中の時計周り）に４２．２７（ｄｅｇ）チルトさせ、かつ第２の偏向器４２へ光源１からの光束が斜入射する側に（図１１中右側）４．０２（ｍｍ）シフトさせている。また、第３走査レンズ５ｃを第２走査レンズ５ｂとは逆側に５．８４（ｍｍ）シフトさせている。
【００８３】
図１２に本実施例４の表示画像（格子）を示し、表１０に本実施例のＴＶディストーションと台形歪みの量を示す。
【００８４】
本実施例４では、ＴＶディストーションは、上辺で０．２９％、下辺で０．１７％、左辺で０．１１％、右辺で０．１１％であり、問題ない程度に小さくし、十分に補正されている。また、台形歪みは、左辺、右辺共に０．１８％であり、問題ない程度に小さくし、良好に補正されている。
【００８５】
このように、１次元偏向器を２つ用いた２次元偏向手段を用いた場合、後方に配置された１次元偏向器の中心軸（回転軸）に対して光源手段から発せられた光束が斜入射し、ＴＶディストーションならびに台形歪みを発生させて問題となるが、走査光学系を構成する透過型光学素子のうち、光学的パワーを有する反射面を持たない素子を１つチルトさせ、光学的パワーを有する反射面を持たない素子を１つをシフトさせることでＴＶディストーションならびに台形歪みを補正することができる。
【００８６】
（実施例５）
図１３は本発明の実施例５における２次元走査装置の垂直断面図である。
【００８７】
本実施例５と実施例１との相違点は、走査光学系５を２枚の走査レンズ５ａ，５ｂにて構成した点である。
【００８８】
表１１に本実施例５の走査光学系の構成を表すレンズデータを示す。
【００８９】
本実施例５では、第１走査レンズ５ａと第２走査レンズ５ｂの双方の両面を回転非対称非球面にて構成している。本実施例５における非球面は、光軸方向（Ｚ方向）における変位量Ｚが、水平方向（Ｘ方向）及び垂直方向（Ｙ方向）の各位置において、次式で表現される形状としている。
【００９０】
【外２】

【００９１】
ここで
ｚ　−−−−　ｚ軸に平行な面のサグ
ｃ　−−−−−　頂点の曲率（ＣＵＹ）
ｋ　−−−−　コーニック定数
Ｃ_{ｊ　−−−−−−}　ｘ^ｍｙ^ｎの係数
【００９２】
本実施例５おいては、第２走査レンズ５ｂを、偏向器４へ光源１からの光束が斜入射する側（図１４中の時計回り）に２１．５３（ｄｅｇ）チルトさせ且つ偏向器４へ光源１からの光束が斜入射する側とは反対側へ６．０６（ｍｍ）シフトさせている。更に、第２走査レンズ５ｂの光出射面はその光入射面に対して、偏向器４へ光源１からの光束が斜入射する側とは反対側（図２３中の反時計回り）に１．６０（ｄｅｇ）チルトさせ且つ偏向器４へ光源１からの光束が斜入射する側とは反対側へ０．２０（ｍｍ）シフトさせている。これにより、被走査面６上に表示される画像のＴＶディストーションならびに台形歪みを補正している。
【００９３】
本実施例５では、特に第２走査レンズ５ｂを回転非対称非球面レンズで構成し且つ上述のとおりチルト及びシフトさせることにより、１枚のレンズのチルト・シフトのみでＴＶディストーションならびに台形歪みを良好に補正している。
【００９４】
図１４に本実施例５の表示画像（格子）を示し、表１２に本実施例５のＴＶディストーションならびに台形歪みの量を示す。ＴＶディストーションは、上辺で０．０７％、下辺で０．０１％、左辺で０．０１％、右辺で０．０１％であり、問題ない程度に小さく、極めて良好に補正されている。また、台形歪みは、左辺，右辺共に０．０２％であり、問題ない程度に小さく、極めて良好に補正されている。
【００９５】
本実施例５のように走査光学系５を構成する透過型光学素子のうち、チルトもしくは、シフトさせる光学的パワーを有する反射面を持たない光学素子を回転非対称非球面レンズとすることでＴＶディストーションならびに台形歪みの補正効果を大きくすることができる。また、走査レンズを１枚だけチルト及びシフトさせるだけで、ＴＶディストーションと台形歪みの補正が可能となり、走査光学系５を構成する光学素子の数を削減することができる。
【００９６】
本実施例５では、チルト及びシフトさせた走査レンズの回転非対称非球面に（ｍ＋ｎ）≦４までの非球面係数を使用したが、これに限ったものではなく、より高次（ｍ＋ｎ）≧６の非球面係数を用いることにより、ＴＶディストーション及び台形歪みの補正をより効果的に行うことが可能となる。
【００９７】
以上説明した各実施例（レンズデータ）では、各光学素子にガラスレンズを使ったものを例に取ったがこれに限ったものではなく、例えば、射出成型により成形されたプラスチックレンズを少なくとも一枚の光学素子に用いることにより、製造が容易になり、コストダウンが図れる。
【００９８】
また、光源手段に青、緑、赤の３色の発光部を備えることにより、２次元カラー画像を表示させることも可能である。これによって、走査型カラー画像表示装置を提供することができる。この場合、青、緑、赤の３色の光を順次／又は同時に偏向器に向けることになる。これ以外にも、白色の光源と青、緑、赤の３色のフィルタを回転可能なターレット上に配置したものとを組み合わせて、青、緑、赤の３色の光を順次／又は同時に偏向器に向けることができる。
【００９９】
このように光源手段から青、緑、赤の３色の光を順次／又は同時に偏向手段へ向けつつ偏向器と走査光学系を使ってカラーの２次元画像を形成する際の光源手段や偏向手段の制御方法は公知なので、ここでは詳細な説明はしない。
【０１００】
また、偏向手段には２次元方向に共振可能なＭＥＭＳ偏向デバイスや、１次元方向に共振可能なＭＥＭＳ偏向デバイスを例に挙げたが、これに限ったものではなく、ガルバノミラーやポリゴンミラーを用いても本発明の効果を十分に得ることができる。
【０１０１】
また、前述の特開平８−１４６３２０号公報に記載があるように電気的にＴＶディストーションを補正する技術もあるので、この種の電気的な補正と本発明における走査光学系による光学的な補正とを組み合わせて画像の歪みを補正する構成を採ることも可能である。
【０１０２】
電気的に補正する場合、偏向器を制御する駆動回路（不図示）により２次元走査の際の反射面の傾斜角度を、光学的補正後の残存ディストーションを補正するように、制御する。
【０１０３】
また、以上説明した各実施例は、被走査面にスクリーン等がありその画像を直接観察する形態の画像表示装置（例えばプロジェクター）を例にとり説明したが、例えば被走査面に形成した画像をリレー光学系等を介して観察形態の画像表示装置（例えばファインダー）にも、本発明は適用できる。
【０１０４】
【表１】

【０１０５】
【表２】

【０１０６】
【表３】

【０１０７】
【表４】

【０１０８】
【表５】

【０１０９】
【表６】

【０１１０】
【表７】

【０１１１】
【表８】

【０１１２】
【表９】

【０１１３】
【表１０】

【０１１４】
【表１１】

【０１１５】
【表１２】

【０１１６】
【発明の効果】
以上、本発明は、走査光学系における光学的パワーを有する反射面を持たない光学素子（例えば球面レンズ）をチルト及び／又はシフトさせることにより、ＴＶディストーションや台形歪みを良好に補正することができる。これによって、ＴＶディストーションや台形歪みが良好に補正できた２次元走査装置と、この２次元走査装を用いて高品位な画像を表示することが可能な画像表示装置とを提供できる。
【図面の簡単な説明】
【図１】本発明の実施例１における斜視図
【図２】２次元偏向器（２次元偏向デバイス）の要部概要図
【図３】本発明の実施例１における垂直断面図
【図４】本発明の比較例における垂直断面図
【図５】本発明の比較例における表示画像（格子）
【図６】本発明の実施例１における表示画像（格子）
【図７】本発明の実施例２における垂直断面図
【図８】本発明の実施例２における表示画像（格子）
【図９】本発明の実施例３における垂直断面図
【図１０】本発明の実施例３における表示画像（格子）
【図１１】本発明の実施例４における垂直断面図
【図１２】本発明の実施例４における表示画像（格子）
【図１３】本発明の実施例５における垂直断面図
【図１４】本発明の実施例５における表示画像（格子）
【符号の説明】
１　光
２　集光レンズ系
３　開口絞り
４　偏向器
５　走査光学系
６　被走査面（スクリーン）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a two-dimensional scanning device for projecting and displaying a two-dimensional image by two-dimensionally scanning light and a scanning image display device using the same.
[0002]
[Prior art]
Various two-dimensional scanning devices that form a two-dimensional image by scanning a scanned surface two-dimensionally with a light spot have been proposed.
[0003]
For example, in Japanese Patent Application Laid-Open No. 08-146320, a light beam emitted from a light source means is deflected by a deflecting means capable of two-dimensionally deflecting, and a scanning lens having a distortion characteristic of f.sin .theta. There is disclosed a two-dimensional scanning device that scans two-dimensionally. This is obtained by correcting image distortion by f · sin θ characteristics of the scanning lens and electrical correction.
[0004]
In addition, Japanese Patent Application Laid-Open No. 2000-281585 includes an optical member that deflects light emitted from a light source by a deflecting unit and has two or more reflecting surfaces including an eccentric non-rotationally symmetric surface having optical power. An example in which a scanning optical system scans a scanned surface two-dimensionally is disclosed. This is a downsizing of the scanning optical system by the lens action and the deflection action of the reflecting surface having the optical power. In addition, decentering causes decentering aberrations such as coma and astigmatism even on an axial ray. This decentering aberration is corrected by making the reflecting surface a rotationally asymmetric surface.
[0005]
[Problems to be solved by the invention]
As described above, the two-dimensional scanning device deflects the light beam emitted from the light source means by the two-dimensionally deflectable deflecting means, and forms a two-dimensional image on the surface to be scanned via the scanning optical system. . At this time, it is generally known that the light beam is two-dimensionally deflected by the deflecting means, so that a two-dimensional image on the surface to be scanned is distorted. This is a so-called distortion. The distortion includes a trapezoidal distortion, a constant-speed scanning distortion and a straight-scanning distortion, and a TV distortion that refers to a curved image frame drawn on the surface to be scanned.
[0006]
In Japanese Patent Application Laid-Open No. 08-146320, the TV distortion is corrected by the f · sin θ characteristic of the scanning optical system and the electrical correction, but it is difficult to electrically correct the TV distortion.
[0007]
Japanese Patent Application Laid-Open No. 2000-281585 does not consider TV distortion.
[0008]
In addition, the optical member constituting the scanning optical system has a rotationally symmetric reflection surface having optical power, and has a drawback that surface accuracy is extremely severe. Further, since it is necessary to secure a folded optical path inside the optical element, there is a problem that the thickness of the optical element increases. Further, when the optical element is made of plastic, there is a problem that the optical element is greatly affected by the internal refractive index distribution and the birefringence.
[0009]
Therefore, an object of the present invention is to provide a two-dimensional scanning device capable of correcting TV distortion and trapezoidal distortion using a scanning optical system that does not include a reflection surface having optical power.
[0010]
[Means for Solving the Problems]
The present invention is characterized in that a tilted and / or shifted optical element having no reflecting surface having optical power in an optical system is used for TV distortion and trapezoidal distortion correction. Here, the tilted and / or shifted optical element is an optical element whose optical axis or reference axis is tilted and / or shifted with respect to an axis (ray) at the center of the two-dimensional deflection range of the light beam by the deflection unit. .
[0011]
Some embodiments of the present invention are described in each of [Claims 1] to [Claim 8] of [Claims], and more specifically, there are the following embodiments. .
[0012]
In the apparatus according to any one of claims 1 to 8, for example, a deflecting unit that deflects a light beam from a light source in a two-dimensional direction, and scans the deflecting light beam deflected by the deflecting device. A scanning optical system for directing light onto a surface, wherein the optical system is tilted with respect to an axis in the center of a range where the light beam is deflected by the deflecting unit, and has no reflecting surface having optical power. And a light beam from the light source is obliquely incident on a reflecting surface of a deflector of the deflecting means, and one of the two-dimensional directions is arranged along a plane of incidence at that time. In a two-dimensional scanning apparatus, the directions correspond, and the optical element is tilted (tilted) around an axis perpendicular to the plane of incidence to a side where the light beam is obliquely incident on the deflector.
(A) The optical element is a meniscus lens having a concave surface facing the deflector.
(B) The optical element is an anamorphic lens having different optical powers in the one-dimensional direction and the other one-dimensional direction orthogonal to the one-dimensional direction.
(C) The optical element is an anamorphic lens in which the optical power in one one-dimensional direction is smaller (preferably close to non-power) than the optical power in the other one-dimensional direction orthogonal to the one-dimensional direction.
(D) The optical element is an aspheric lens having a non-rotationally symmetric aspheric surface.
(E) In the optical element, the light entrance surface and the light exit surface are eccentric to each other.
(F) The optical system has a plurality of optical elements. In the one-dimensional direction, when the side on which the light beam is obliquely incident on the deflector is a minus side and the opposite side is a plus side, the optical element is The second optical element is tilted and shifted (displaced) to the minus side, and is shifted to the plus side.
[0013]
In the one-dimensional direction, when the side on which the light beam is obliquely incident on the deflector is a minus side and the opposite side is a plus side, the optical element is tilted to the minus side, and the optical element is the plus side. Has shifted to the side.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
(Example 1)
FIG. 1 is a perspective view of a two-dimensional scanning device according to a first embodiment of the present invention. The first embodiment is an example in which the two-dimensional scanning device is used for an image display device such as a projector.
[0015]
In FIG. 1, reference numeral 1 denotes a light source. The light source 1 includes a laser diode, an LED, a lamp, and the like, and light emission is controlled by a drive circuit (not shown) according to, for example, an image signal. The divergent light beam emitted from the light source 1 is converted into a convergent light beam by a condenser lens system 2 in which two condenser lenses 2a and 2b are bonded, and the light beam width is limited by an aperture stop 3. Reference numeral 4 denotes a deflector, for example, a deflector (deflecting means) having one reflecting surface rotatable around two rotation axes extending in directions orthogonal to each other and capable of resonating in a two-dimensional direction. The reflector 4 reflects and deflects the light flux emitted from the light source 1 and passed through the condenser lens system 2 and the aperture stop 3 and returned by the return mirror 7, and performs two-dimensional horizontal and vertical directions (X and Y directions). Is deflected. The tilt direction and tilt angle of the deflector 4 are controlled by a drive circuit (not shown) according to, for example, an image signal.
[0016]
Reference numeral 5 denotes a scanning optical system having fθ characteristics. The scanning optical system 5 has three spherical lenses 5a, 5b, 5c, and forms an image of the deflected light beam deflected by the deflecting means 4 as a spot on the surface 6 to be scanned. At this time, the deflected light beam is guided onto the surface 6 to be scanned via the scanning optical system 5, and the deflector resonates in the horizontal and vertical directions to optically scan the surface 6 to be scanned. Thus, a two-dimensional image is displayed on the scanned surface 6.
[0017]
The two-dimensional deflector 4 of the first embodiment is a known MEMS (Micro Electro-Mechanical Scanner) using, for example, a semiconductor manufacturing technique, and is extremely small and lightweight.
[0018]
FIG. 2 shows a schematic diagram of a main part of the deflector 4, which is shown at the same time as an example, and the configuration of the deflector is not limited in the present invention.
[0019]
In FIG. 2, reference numeral 4a denotes a reflection surface, on which a light beam from the light source 1 enters, is reflected and deflected. The reflection surface 4a is supported by the first housing 4c by a first torsion bar 4b extending in the Y-axis direction, and the reflection surface 4a is set in the horizontal direction (X-axis direction) with the first torsion bar 4b as a rotation center axis. Can be vibrated. Further, the first housing 4c is supported by the second housing 4e by a second torsion bar 4d extending in the X-axis direction. The first housing 4c and the second housing 4c have the second torsion bar as a rotation center axis. The reflecting surface 4a supported thereby can be vibrated in the vertical direction (Y direction). Thus, the deflector 4 can vibrate in a horizontal and vertical two-dimensional direction as a two-dimensional light deflecting device.
[0020]
Further, the two-dimensional deflection device is manufactured by MEMS technology using, for example, a semiconductor manufacturing technology, and has an advantage that it is extremely small and lightweight.
[0021]
FIG. 3 is a vertical sectional view (YZ section) of the two-dimensional scanning device according to the first embodiment. Here, this vertical cross section corresponds to the plane of incidence when the light beam is obliquely incident on the reflecting surface 4a of the deflector 4.
[0022]
In this embodiment, when the light beam from the light source 1 is incident on the deflector 4, the incident light beam is reflected from the lower side in the vertical direction (right side of the deflector 4 in FIG. 3) at an angle of 15 (deg) from the reflection surface of the deflector 4. 4a. The deflector 4 is a two-dimensional light deflecting device. A first torsion bar 4b serving as a rotation center axis when the reflecting surface 4a shown in FIG. 2 is vibrated in the horizontal direction is parallel to the vertical direction. A second torsion bar serving as a central axis when vibrating in the vertical direction is arranged parallel to the horizontal direction. Therefore, the light flux from the light source means 1 is obliquely incident on the first torsion bar 4b. As described above, when the light is obliquely incident on the central axis of the deflecting means 4, usually, an image displayed on the surface to be scanned (for example, a screen) has a problem that a large TV distortion occurs.
[0023]
However, in the first embodiment, the side where the light beam is obliquely incident on the deflector 4 around the axis parallel to the X-axis, which is an axis perpendicular to the plane of incidence of the light beam incident on the reflecting surface 4a, through the spherical lens 5b ( It is tilted and shifted with respect to the axis (light ray) A at the center of the light beam deflection range of the deflector 4 to the minus side, and the spherical lens 5c is shifted to the opposite side (plus side) to the side where the light beam obliquely enters the deflector 4. This distortion is favorably corrected by shifting the axis (light ray) A at the center of the light beam deflection range. This will be described later in detail with numerical examples.
[0024]
FIG. 4 is a vertical sectional view of a two-dimensional scanning device which is a comparative example of the first embodiment.
[0025]
In the comparative example shown in FIG. 4, the divergent light beam emitted from the light source 1 is converted into a convergent light beam by the condenser lens system 2, the light beam width is limited by the aperture stop 3, and the deflector is 4, the light is reflected and deflected in two horizontal and vertical directions. Reference numeral 5 denotes a scanning optical system having fθ characteristics. The scanning optical system 5 has three spherical lenses 5a, 5b, and 5c coaxial with each other, and forms an image of the deflected light beam deflected by the deflecting means 4 on the surface 6 to be scanned as a light spot. . At this time, the deflector 4 resonates in the horizontal and vertical directions to optically scan the surface 6 to be scanned via the scanning optical system 5.
[0026]
Table 1 shows lens data representing the configuration of the scanning optical system of the comparative example.
[0027]
In the comparative example, the three spherical lenses 5a, 5b, 5c constituting the scanning optical system 5 do not shift or tilt, and the luminous flux toward the center of the image displayed on the surface 6 to be scanned is the spherical surface. It passes through the optical axes of the lenses 5a, 5b, 5c.
[0028]
Further, the light beam from the light source 1 is incident on the reflecting surface of the deflector 4 at an angle of 15 (deg) from below in the vertical cross section, and the light beam is incident on the deflector 4 in the vertical cross section by oblique incidence. On the surface 6 to be scanned, a TV distortion caused by optical scanning in the two-dimensional direction by the deflecting means 5 and a trapezoidal distortion caused by obliquely entering the deflector 4 occur.
[0029]
FIG. 5 shows a display image (grating) in the comparative example. Table 2 shows the amounts of TV distortion and trapezoidal distortion in Comparative Examples.
[0030]
As shown in FIG. 5, among the four lines constituting the frame of the image, the upper side L1 and the lower side L2 of the frame should be horizontally extending straight lines, but the TV distortion in which the center of each side is curved downward. Has occurred. At this time, the TV distortion was 1.59% on the upper side and 1.93% on the lower side (see Table 2). Further, the left side L3 and the right side L4 of the frame should be straight lines extending vertically, but are inclined so that the interval increases from the upper side to the lower side of the image, and trapezoidal distortion occurs. At this time, the trapezoidal distortion was 2.11% for both the left and right sides (see Table 2).
[0031]
As described above, in the configuration of the comparative example, TV distortion and trapezoidal distortion are largely generated, and a good two-dimensional image cannot be obtained.
[0032]
Therefore, in the first embodiment, as described above, at least one of the spherical lenses 5a, 5b, and 5c constituting the scanning optical system is tilted and at least one lens is shifted, so that the TV distortion and the trapezoidal shape are obtained. The distortion is satisfactorily corrected or reduced to the extent that no problem occurs.
[0033]
Table 3 shows lens data indicating the configuration of the scanning optical system 5 of the first embodiment.
[0034]
The scanning optical system 5 includes three spherical lenses 5a, 5b, and 5c, which are referred to as a first scanning lens, a second scanning lens, and a third scanning lens in this order from the deflector 4 side. The first scanning lens 5a is a meniscus lens having negative optical power (refractive power, 1 / focal length) and having a concave surface facing the deflector 4 side. The second scanning lens 5b is a meniscus lens having a positive power and having a concave surface facing the deflector 4 side, and the third scanning lens 5c is a meniscus lens having a positive power and having a concave surface facing the deflector 4 side.
[0035]
At this time, the second scanning lens 5b is tilted clockwise (minus side) by 36.1 (deg) in the vertical section. This is a direction in which the optical axis of the second scanning lens 5b is inclined toward the light beam L obliquely incident on the deflector 4, and approaches the light beam L obliquely incident. The second scanning lens 5b is shifted 4.64 (mm) downward (minus side). This moves in a direction approaching the obliquely incident light flux L. Therefore, the rotation center of the second scanning lens 5b is on the deflector 4 side, and is tilted so as to approach the incident light beam. At this time, the rotation center is located at a position (z, x, y) = (11.14, 0, 0) moved to the deflector 4 side by 6.36 (mm) from the light incident surface of the second scanning lens 5b.
[0036]
Further, the third scanning lens 5c is shifted upward (plus side) by 2.76 (mm). This is the direction away from the incident light beam.
[0037]
FIG. 6 shows a display image (grating) according to the first embodiment. Table 4 shows the amounts of TV distortion and trapezoidal distortion in this example.
[0038]
The TV distortion of the image shown in FIG. 6 is such that the upper side L1 of the frame is 0.12% and the lower side L2 is 0.21%. In the comparative example, the curved upper side L1 and lower side L2 are corrected to be substantially straight lines. I have. The trapezoidal distortion is 0.10% for both the left and right sides. In the comparative example, the inclined line is corrected to a vertical line. As described above, by giving an appropriate tilt or shift to the scanning lens constituting the scanning optical system 5, the TV distortion and the trapezoidal distortion can be reduced to a level that does not cause any problem, and the correction can be performed well.
[0039]
The scanning optical system of the first embodiment corrects the TV distortion by tilting the second scanning lens 5b, and corrects the trapezoidal distortion by shifting the second scanning lens 5b and the third scanning lens 5c. I have. However, since the tilt correction and the shift correction affect each other, it is important to balance them.
[0040]
Therefore, the light beam from the light source is obliquely incident on the deflector 4, and at least one transmission optical element of the transmission optical elements constituting the scanning optical system 5 is provided in the obliquely incident cross section, that is, in the incident plane. By tilting and shifting at least one transmission optical element, a two-dimensional scanning apparatus capable of satisfactorily correcting TV distortion and trapezoidal distortion of an image displayed on the surface 6 to be scanned and displaying a high-quality image is provided. Can be provided.
[0041]
In the first embodiment, the scanning lens (optical element having no reflecting surface having optical power) 5b to be tilted has a meniscus shape with the concave surface facing the deflector 4 side. Thereby, when the scanning lens 5b is tilted, the influence on the field curvature can be reduced while maintaining the influence on the TV distortion and the trapezoidal distortion. Therefore, it is possible to correct the TV distortion and the trapezoidal distortion separately from the curvature of field, and it is possible to easily correct the TV distortion and the trapezoidal distortion.
[0042]
In the first embodiment, an example in which one deflector 4 capable of resonating in the two-dimensional direction is used as the deflecting means, but the present invention is not limited to this. The same effect as that of the first embodiment can be obtained as a deflecting unit that can deflect in the dimensional direction. Further, the deflector is not limited to the one that resonates, but may be a galvanomirror or a polygon mirror that rotates.
[0043]
The optical surfaces (surfaces acting on light to be directed to the surface to be scanned) of the three optical elements (scanning lenses) constituting the scanning optical system of the first embodiment are all refractive surfaces that transmit light and control the wavefront thereof. It consists of. The refracting surface has a merit that the manufacturing is easy since the refracting surface has a precision of 1/4 of the reflecting surface. In addition, the reflection surface is restricted in the arrangement of the optical path after the tilt, but the transmission type refraction surface is not affected by the restriction. Furthermore, the transmittance on the refraction surface is higher than the reflectance on the reflection surface, and the refraction surface has an advantage that the loss of light amount is very small, and is particularly effective when the number of surfaces is large. Further, the transmittance becomes extremely high by attaching the antireflection film.
[0044]
Further, in an optical element in which a refracting surface and a reflecting surface are mixed, it is necessary to secure an optical path inside the optical element, and there is a problem that the optical element itself becomes large. Further, the problem of the enlargement also causes a problem that the influence of the refractive index distribution and birefringence generated when the optical element is formed by plastic molding becomes large.
[0045]
However, the scanning lens in which the optical surface is constituted by a refracting surface as in the first embodiment does not need to secure an optical path, so that it can be made thinner, which is advantageous for miniaturization.
[0046]
Therefore, when an optical element having no reflecting surface for directing light to the surface to be scanned is used in the scanning optical system, various effects can be obtained as compared with the above-described optical member having the reflecting surface in JP-A-2001-281584. it can. In the present invention, an optical element using a diffractive surface that transmits and diffracts light instead of or in combination with the refractive surface can also be used to correct image distortion on the scanned surface.
[0047]
Further, in the first embodiment, the light beam from the light source means is obliquely incident on the ZY plane. However, the present invention is not limited thereto. By tilting and / or shifting, TV distortion and trapezoidal distortion can be corrected in the same manner as in the first embodiment. When oblique incidence is performed on both the ZX plane and the ZY plane, the transmission optical element is shifted to the ZX plane. By tilting and / or shifting the transmission optical element in at least one one-dimensional direction of the ZY plane, TV distortion and trapezoidal distortion can be corrected as in the first embodiment.
[0048]
(Example 2)
FIG. 7 is a vertical sectional view of the two-dimensional scanning device according to the second embodiment of the present invention.
[0049]
The difference between the second embodiment and the first embodiment is that the screen size displayed on the surface 6 to be scanned is increased. Therefore, the configuration of the scanning optical system is different. It has the same configuration as the device of FIG. 3 except for the optical system.
[0050]
The second embodiment is a scanning optical system capable of increasing the screen size by 1.4 times as compared with the first embodiment, but the total length (the distance between the deflector 4 and the surface 6 to be scanned) is only 1.1 times. This is an example of miniaturization.
[0051]
Table 5 shows lens data representing the configuration of the scanning optical system 5 in the second embodiment.
[0052]
In the second embodiment, as in the first embodiment, of the three scanning lenses 5a, 5b, and 5c constituting the scanning optical system 5, the second scanning lens 5b is tilted and shifted, and the third scanning lens 5c is moved. Are shifted, the TV distortion and the trapezoidal distortion of the image displayed on the scanned surface 6 are corrected. At this time, in the vertical section which is the ZY plane, the second scanning lens 5b tilts the light beam from the light source means 1 obliquely into the deflector 4 (44.38 (deg)) on the side (minus side) and deflects. The light beam from the light source means 1 is shifted 5.05 mm to the obliquely incident side (negative side) to the container 4. The third scanning lens 5c is shifted by 24.57 mm to the side (plus side) opposite to the side on which the light beam from the light source unit 1 is obliquely incident on the deflecting unit 4.
[0053]
FIG. 8 shows a display image (grating) of the second embodiment, and Table 6 shows TV distortions and trapezoidal distortion amounts of the second embodiment.
[0054]
In the second embodiment, the TV distortion is 0.12% on the upper side of the image frame, 0.24% on the lower side, 0.11% on the left side, and 0.11% on the right side, which are small enough to cause no problem. , Has been well corrected. The trapezoidal distortion is 0.06% on the left and right sides of the image frame, is small enough to cause no problem, and is well corrected.
[0055]
Further, when it is desired to reduce the overall length while increasing the screen size, the tilt amount of the scanning lens 5b increases to correct TV distortion or trapezoidal distortion, and the tilt amount of the scanning lens 5b is generated on the scanned surface 6 due to the tilt of the scanning lens 5b. The amount of ass produced increases. Therefore, in the second embodiment, an optical element having anamorphic power is included in the scanning optical system. Specifically, both of the second scanning lens 5b and the third scanning lens 5c are anamorphic lenses formed on the anamorphic surface.
[0056]
In particular, in the second scanning lens 5b, the optical power in the vertical section (ZY section) is made smaller than the optical power in the horizontal section (ZX section) to approach non-power, and the second scanning lens 5b tilts. This reduces the inclination of the curvature of field in the vertical section. This makes it possible to satisfactorily correct the TV distortion and the trapezoidal distortion by tilting the second scanning lens 5b greatly. In addition, assembling can be corrected by using the third scanning lens 5c as an anamorphic lens.
[0057]
Since the scanning lens to be tilted is preferably a meniscus lens having a concave surface directed to the deflector 4, the second scanning lens 5b has a meniscus shape with a concave surface facing the deflector 4 side in both horizontal and vertical sections. An anamorphic lens.
[0058]
In addition, the second scanning lens 5b increases the effect of correcting TV distortion and trapezoidal distortion by making the radius of curvature of the vertical section smaller than the radius of curvature of the horizontal section (making the radius of curvature larger in absolute value). be able to.
[0059]
As described above, by tilting and / or shifting the optical element having anamorphic optical power, the effect of correcting TV distortion and trapezoidal distortion and the effect of correcting astigmatism can be obtained, and a high-quality large screen can be obtained. A two-dimensional scanning device can be provided.
[0060]
In particular, when an optical element to be tilted has anamorphic power, a section to be tilted is a first section, and a section orthogonal to the first section and the optical axis is a second section, the optical section in the first section is By making the optical power smaller than the optical power in the second cross section and approaching the non-power, the influence of tilting on the field curvature can be reduced and the focus can be concentrated on the correction of TV distortion and trapezoidal distortion. , TV distortion and trapezoidal distortion can be independently corrected.
[0061]
As in the second embodiment, the scanning lenses 5b and 5c, which are tilted and / or shifted and have many unused portions, can be compactly stored in an optical box by cutting while leaving only the used portions.
[0062]
(Example 3)
FIG. 8 is a vertical sectional view of the two-dimensional scanning device according to the third embodiment of the present invention.
[0063]
The difference between the third embodiment and the second embodiment is that the screen size displayed on the scanned surface 6 is further increased, and the third embodiment has the same basic configuration as the second embodiment. Therefore, only the differences will be described in detail.
[0064]
In the third embodiment, the screen size to be displayed on the scanned surface 6 is 4.1 (inch), and the scanning optical system has a screen size 2.86 times larger than that of the second embodiment.
[0065]
Table 7 shows lens data representing the configuration of the scanning optical system of the third embodiment.
[0066]
In the third embodiment, the second scanning lens 5b is an anamorphic lens having a meniscus shape concave toward the deflecting means 4, and both surfaces are different from each other in a horizontal section (ZX section) and a vertical section (ZY section). It is configured as a rotationally asymmetric aspherical surface having an aspherical amount.
[0067]
Further, the aspherical surface in the present embodiment has a shape in which the displacement amount Z in the optical axis direction (Z direction) is expressed by the following equation at each position in the horizontal direction (X direction) and the vertical direction (Y direction). .
[0068]
[Outside 1]

[0069]
here
z −−−−− サ Sag of plane parallel to z axis
CUX, CUY {−−−−−} Curvature of x and y respectively
KX, KY-----Estimate the eccentricity using the same method as for the ASP surface type K, using the cone coefficients of x and y, respectively.
AR, BR, CR, DR − − ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ − ４ ４ − ４ ４ ４ ４ − − ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４ ４
AP, BP, CP, DP {---------} Represents the transformed non-rotationally symmetric part of the fourth, sixth, eighth and tenth order from the cone.
[0070]
In the third embodiment, the total length is 2.77 times that of the second embodiment, which is almost equal to the magnification obtained by increasing the screen size, and the distance from the deflector 4 to the third scanning lens 5c is 42.00 (mm). They are arranged at substantially the same distance as in the second embodiment. This reduces the distance from the deflector 4 to the third scanning lens 5c with respect to the entire length, thereby miniaturizing the scanning optical system. In the third embodiment, the total length L is 175.88 (mm), and the distance d from the deflector 4 to the scanning lens 5c disposed closest to the surface 6 to be scanned is d = 42.00 (mm).
d / L = 0.24
Thus, a very compact two-dimensional scanning optical system can be configured despite the large screen size.
[0071]
In the third embodiment, the second scanning lens 5b is tilted 53.74 (deg) to the side where the light beam from the light source 1 obliquely enters the deflector 4 and is shifted 6.42 (mm) to the side where the oblique incidence occurs. ing. Further, the third scanning lens 5c is tilted by 2.76 (deg) to the side where the light beam from the light source 1 obliquely enters the deflector 4, and shifted by 22.49 (mm) to the side opposite to the obliquely incident side. Let me.
[0072]
FIG. 10 shows a display image (grating) of the third embodiment, and Table 8 shows TV distortion and trapezoidal distortion amounts of the third embodiment.
[0073]
In the third embodiment, the TV distortion is 0.23% on the upper side of the image, 0.36% on the lower side, 0.12% on the left side, and 0.12% on the right side. Has been corrected. The trapezoidal distortion is 0.38% for both the left and right sides, is small enough to cause no problem, and is well corrected.
[0074]
By using a rotationally asymmetric aspherical surface (refractive surface or transmission diffraction surface) for the tilted optical element as in the third embodiment, TV distortion and trapezoidal distortion can be more effectively corrected. In the third embodiment, two transmission optical elements are tilted and shifted. However, the present invention is not limited to this. For example, even if three or more transmission optical elements are tilted and / or shifted, The effect can be sufficiently obtained.
[0075]
(Example 4)
FIG. 11 is a vertical sectional view of the two-dimensional scanning device according to the fourth embodiment of the present invention.
[0076]
The difference between the fourth embodiment and the first embodiment is that a two-dimensional deflecting unit is configured using two one-dimensional deflectors that can deflect in a one-dimensional direction.
[0077]
Each of the two deflectors of the fourth embodiment has a reflection surface supported by the housing by one torsion bar, and the reflection surface 4a, the first torsion bar 4b, and the first housing in FIG. It is composed of a body 4c.
[0078]
The divergent light beam emitted from the light source 1 is converted into a convergent light beam by the condenser lens 2, and the light beam width is limited by the aperture stop 3. The deflector 4 includes a first one-dimensional deflector 41 that can deflect in the vertical direction and a second one-dimensional deflector 42 that can deflect in the horizontal direction. The light is deflected in the vertical direction by the deflector 41 and is deflected in the horizontal direction by the second deflector 42, thereby being deflected in the two-dimensional direction. The light beam deflected by the deflector 4 is imaged as a light spot on a scanned surface 6 by a scanning optical system 5 including three scanning lenses.
[0079]
Table 9 shows lens data representing the configuration of the scanning optical system in the fourth embodiment.
[0080]
The scanning optical system 5 according to the fourth embodiment also includes three scanning lenses. When the first scanning lens 5a, the second scanning lens 5b, and the third scanning lens 5c are sequentially arranged from the deflector 4 side, the first scanning lens 5a is a meniscus lens having a negative optical liquid power with a concave surface facing the deflector 4 side, the second scanning lens 5b is a meniscus lens with a positive optical power having a concave surface facing the deflector 4 and Both surfaces are constituted by anamorphic surfaces, and the third scanning lens 5c is a biconvex lens having a positive optical power.
[0081]
In the fourth embodiment, the light beam from the light source 1 is first made incident on the first deflector 41 which can be deflected in the vertical direction, and then is made incident on the second deflector 42 which can be deflected in the horizontal direction. At this time, the light beam from the light source 1 is incident on the first deflector 41 in the vertical section. The rotation center axis of the first deflector 41 is in a horizontal cross section, and the incident light beam and the rotation center axis of the reflection surface of the deflector exist in different cross sections. However, since the rotation center axis of the second deflector 42 exists in the vertical cross section like the incident light beam, the light beam deflected by the first deflector 41 obliquely enters the second deflector 42. As a result, TV distortion and trapezoidal distortion occur, which is a problem.
[0082]
Therefore, in the fourth embodiment, the second scanning lens 5b is moved to the second deflector 42 in the vertical cross section by 42.27 (deg.) On the side where the light beam from the light source 1 obliquely enters (clockwise in FIG. 11). ) It is tilted and shifted by 4.02 (mm) to the side where the light beam from the light source 1 obliquely enters the second deflector 42 (right side in FIG. 11). Further, the third scanning lens 5c is shifted by 5.84 (mm) to the opposite side of the second scanning lens 5b.
[0083]
FIG. 12 shows a display image (grating) of the fourth embodiment, and Table 10 shows the amounts of TV distortion and trapezoidal distortion of the fourth embodiment.
[0084]
In the fourth embodiment, the TV distortion is 0.29% on the upper side, 0.17% on the lower side, 0.11% on the left side, and 0.11% on the right side. Have been. The trapezoidal distortion is 0.18% for both the left side and the right side, which is small enough to cause no problem, and is well corrected.
[0085]
As described above, when the two-dimensional deflecting means using two one-dimensional deflectors is used, the light beam emitted from the light source means is oblique with respect to the central axis (rotation axis) of the one-dimensional deflector arranged behind. Incident, causing TV distortion and trapezoidal distortion, which is problematic. Among the transmission type optical elements constituting the scanning optical system, one element having no reflection surface having optical power is tilted, and the optical power is tilted. The TV distortion and the trapezoidal distortion can be corrected by shifting one of the elements having no reflecting surface having the following.
[0086]
(Example 5)
FIG. 13 is a vertical sectional view of the two-dimensional scanning device according to the fifth embodiment of the present invention.
[0087]
The difference between the fifth embodiment and the first embodiment is that the scanning optical system 5 is composed of two scanning lenses 5a and 5b.
[0088]
Table 11 shows lens data representing the configuration of the scanning optical system of the fifth embodiment.
[0089]
In the fifth embodiment, both surfaces of the first scanning lens 5a and the second scanning lens 5b are constituted by rotationally asymmetric aspheric surfaces. The aspherical surface in the fifth embodiment has a shape in which the displacement Z in the optical axis direction (Z direction) is expressed by the following equation at each position in the horizontal direction (X direction) and the vertical direction (Y direction).
[0090]
[Outside 2]

[0091]
here
z --- Sag of plane parallel to z-axis
c-------Curvature of the vertex (CUY)
k −−−− conic constant
C_{j −−−−−−−}X^myⁿCoefficient
[0092]
In the fifth embodiment, the second scanning lens 5b is tilted by 21.53 (deg) to the side where the light beam from the light source 1 is obliquely incident on the deflector 4 (clockwise in FIG. 14), and the deflector 4 is tilted. The light beam from the light source 1 is shifted 6.06 (mm) to the side opposite to the side obliquely incident. Further, the light exit surface of the second scanning lens 5b is positioned on the opposite side (counterclockwise in FIG. 23) of the light entrance surface from the side where the light beam from the light source 1 obliquely enters the deflector 4. It is tilted by 60 (deg) and shifted by 0.20 (mm) to the side opposite to the side where the light beam from the light source 1 obliquely enters the deflector 4. Thereby, TV distortion and trapezoidal distortion of the image displayed on the scanned surface 6 are corrected.
[0093]
In the fifth embodiment, in particular, the second scanning lens 5b is formed of a rotationally asymmetric aspherical lens and is tilted and shifted as described above, so that TV distortion and trapezoidal distortion can be satisfactorily achieved only by tilt shift of one lens. It has been corrected.
[0094]
FIG. 14 shows a display image (grating) of the fifth embodiment, and Table 12 shows TV distortion and trapezoidal distortion amounts of the fifth embodiment. The TV distortion is 0.07% on the upper side, 0.01% on the lower side, 0.01% on the left side, and 0.01% on the right side, which are small enough to cause no problem and are corrected very well. The trapezoidal distortion is 0.02% for both the left side and the right side, is small enough to cause no problem, and is corrected very well.
[0095]
As in the fifth embodiment, among the transmission optical elements constituting the scanning optical system 5, an optical element having no reflection surface having an optical power for tilting or shifting is made to be a rotationally asymmetric aspherical lens, so that TV distortion is achieved. In addition, the effect of correcting trapezoidal distortion can be increased. Further, the TV distortion and the trapezoidal distortion can be corrected only by tilting and shifting one scanning lens, and the number of optical elements constituting the scanning optical system 5 can be reduced.
[0096]
In the fifth embodiment, the aspherical coefficient up to (m + n) ≦ 4 is used for the rotationally asymmetric aspherical surface of the tilted and shifted scanning lens. However, the present invention is not limited to this. By using the aspherical coefficient of (1), it is possible to more effectively correct TV distortion and trapezoidal distortion.
[0097]
In each of the embodiments (lens data) described above, an example in which a glass lens is used for each optical element is taken as an example. However, the present invention is not limited to this. For example, at least one plastic lens molded by injection molding is used. By using such an optical element, the manufacturing becomes easy and the cost can be reduced.
[0098]
Further, by providing the light source means with light emitting units of three colors of blue, green and red, it is possible to display a two-dimensional color image. Thereby, a scanning type color image display device can be provided. In this case, light of three colors of blue, green, and red is sequentially and / or simultaneously directed to the deflector. In addition, a white light source is combined with a blue, green, and red filter arranged on a rotatable turret to deflect blue, green, and red light sequentially and / or simultaneously. Can be turned to a bowl.
[0099]
The light source means and the deflecting means for forming a two-dimensional color image using the deflector and the scanning optical system while sequentially and / or simultaneously directing the three color lights of blue, green and red from the light source means to the deflecting means. Since the control method is well known, a detailed description will not be given here.
[0100]
The MEMS deflection device capable of resonating in a two-dimensional direction and the MEMS deflection device capable of resonating in a one-dimensional direction have been exemplified as the deflecting means. However, the present invention is not limited to this, and a galvano mirror or a polygon mirror may be used. However, the effect of the present invention can be sufficiently obtained.
[0101]
There is also a technique for electrically correcting TV distortion as described in the above-mentioned Japanese Patent Application Laid-Open No. 8-146320. Therefore, this kind of electrical correction and optical correction by the scanning optical system according to the present invention are required. May be combined to correct image distortion.
[0102]
In the case of electrical correction, a drive circuit (not shown) for controlling the deflector controls the inclination angle of the reflection surface during two-dimensional scanning so as to correct the residual distortion after optical correction.
[0103]
In each of the embodiments described above, an image display device (for example, a projector) having a screen or the like on the surface to be scanned and directly observing the image has been described. However, for example, an image formed on the surface to be scanned is relayed. The present invention can be applied to an image display device (for example, a finder) in an observation form via an optical system or the like.
[0104]
[Table 1]

[0105]
[Table 2]

[0106]
[Table 3]

[0107]
[Table 4]

[0108]
[Table 5]

[0109]
[Table 6]

[0110]
[Table 7]

[0111]
[Table 8]

[0112]
[Table 9]

[0113]
[Table 10]

[0114]
[Table 11]

[0115]
[Table 12]

[0116]
【The invention's effect】
As described above, according to the present invention, TV distortion and trapezoidal distortion can be satisfactorily corrected by tilting and / or shifting an optical element (for example, a spherical lens) having a reflection surface having optical power in a scanning optical system. . As a result, it is possible to provide a two-dimensional scanning device capable of favorably correcting TV distortion and trapezoidal distortion, and an image display device capable of displaying a high-quality image using the two-dimensional scanning device.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first embodiment of the present invention.
FIG. 2 is a schematic diagram of a main part of a two-dimensional deflector (two-dimensional deflection device).
FIG. 3 is a vertical sectional view according to the first embodiment of the present invention.
FIG. 4 is a vertical sectional view of a comparative example of the present invention.
FIG. 5 is a display image (grid) in a comparative example of the present invention.
FIG. 6 is a display image (grating) according to the first embodiment of the present invention.
FIG. 7 is a vertical sectional view according to a second embodiment of the present invention.
FIG. 8 is a display image (grating) according to the second embodiment of the present invention.
FIG. 9 is a vertical sectional view according to a third embodiment of the present invention.
FIG. 10 is a display image (grating) according to the third embodiment of the present invention.
FIG. 11 is a vertical sectional view according to a fourth embodiment of the present invention.
FIG. 12 is a display image (grating) according to the fourth embodiment of the present invention.
FIG. 13 is a vertical sectional view according to a fifth embodiment of the present invention.
FIG. 14 is a display image (grating) according to the fifth embodiment of the present invention.
[Explanation of symbols]
1 light
2 Condensing lens system
3 aperture stop
4 deflector
5 scanning optical system
6 Scanned surface (screen)

Claims (8)

Deflecting means for deflecting a light beam from the light source in a two-dimensional direction;
An optical system for directing a deflected light beam deflected by the deflecting means onto a surface to be scanned.
The two-dimensional scanning apparatus, wherein the scanning optical system does not have a reflective surface having optical power and has a tilted and / or shifted optical element. The light flux from the light source is obliquely incident on the reflection surface of the deflecting unit, and one of the two-dimensional directions corresponds to a direction along the plane of incidence at that time,
2. The two-dimensional scanning device according to claim 1, wherein the optical element is tilted to a side on which the light beam obliquely enters the deflector around an axis perpendicular to the incident plane. 3. In at least one one-dimensional direction of the two-dimensional direction, a light beam from the light source means is obliquely incident on an axis at the center of a range deflected by the deflecting means,
2. The two-dimensional scanning device according to claim 1, wherein the optical element is tilted in the one-dimensional direction to a side where the light flux is obliquely incident. 3. The two-dimensional scanning device according to claim 2, wherein the optical element is shifted in the one-dimensional direction. The said optical system has the 2nd optical element shifted in the said one-dimensional direction, The 2nd optical element does not have the reflective surface which has optical power, The Claim 2 or Claim 3 characterized by the above-mentioned. Two-dimensional scanning device. Distortion on the surface to be scanned is corrected optically by the optical system, or corrected by a combination of optical correction by the optical system and electrical correction by a circuit that controls the deflecting unit. The two-dimensional scanning device according to claim 1. An image display device comprising: means for forming an image on the surface to be scanned by the two-dimensional scanning device according to claim 1. Light source means for supplying light beams of three colors, such as red, green, and blue, and forming a color image on the surface to be scanned by sequentially and / or simultaneously entering the light beams of the three colors into the deflector. The image display device according to claim 7, wherein:

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