JP2001116990A - Lens for projection - Google Patents
Lens for projectionInfo
- Publication number
- JP2001116990A JP2001116990A JP29839999A JP29839999A JP2001116990A JP 2001116990 A JP2001116990 A JP 2001116990A JP 29839999 A JP29839999 A JP 29839999A JP 29839999 A JP29839999 A JP 29839999A JP 2001116990 A JP2001116990 A JP 2001116990A
- Authority
- JP
- Japan
- Prior art keywords
- lens
- lens group
- projection
- group
- projection lens
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、液晶パネル等に
表示される平面画像を、拡大してスクリーン等の表示媒
体上に投射結像させる投射用レンズに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection lens for enlarging a planar image displayed on a liquid crystal panel or the like and projecting it on a display medium such as a screen.
【０００２】[0002]
【従来の技術】液晶パネルに表示された平面画像を、ス
クリーン等の表示媒体上に拡大投射する液晶プロジェク
タは、ビデオ再生画像やコンピュータのデータ等の表示
用として、近来広く普及してきている。なかでも、赤・
緑・青の各色画像を、独立した液晶パネル（液晶ライト
バルブ等）に表示し、各色画像を合成して拡大投影表示
する「３板式液晶プロジェクタ」は、画像が高精細であ
ることから普及率も高い。図１８は、従来から知られた
３板式液晶プロジェクタの、光学配置を説明図として示
している。符号１〜３は液晶ライトバルブを示す。液晶
ライトバルブ１は青画像表示用であり、液晶ライトバル
ブ２および３はそれぞれ、緑画像および赤画像表示用で
ある。符号４は「色合成手段」としてのクロス型ダイク
ロイックプリズム、符号５は投射用レンズ、符号６は
「表示媒体」としてのスクリーンを示す。図示されない
照明光源光学系により、液晶ライトバルブ１には青色
光、液晶ライトバルブ２には緑色光、液晶ライトバルブ
３には赤色光がそれぞれ照射され、各液晶ライトバルブ
を透過した光（各液晶ライトバルブに表示された画像に
より２次元的に変調されている）は、クロス型ダイクロ
イックプリズム４で合成されて投射用レンズ５に入射す
る。投射用レンズ５から射出した光は、液晶ライトバル
ブ１，２，３の画像情報を、合成してカラー画像として
スクリーン６上に拡大して投影表示する。2. Description of the Related Art A liquid crystal projector for enlarging and projecting a flat image displayed on a liquid crystal panel onto a display medium such as a screen has recently been widely used for displaying video reproduction images, computer data, and the like. Above all, red
The “three-panel liquid crystal projector,” which displays each color image of green and blue on an independent liquid crystal panel (liquid crystal light valve, etc.), synthesizes each color image, and displays the enlarged image, has a high definition because the image is of high definition. Is also expensive. FIG. 18 is an explanatory diagram showing an optical arrangement of a conventionally known three-panel liquid crystal projector. Reference numerals 1 to 3 indicate liquid crystal light valves. The liquid crystal light valve 1 is for displaying a blue image, and the liquid crystal light valves 2 and 3 are for displaying a green image and a red image, respectively. Reference numeral 4 denotes a cross type dichroic prism as “color combining means”, reference numeral 5 denotes a projection lens, and reference numeral 6 denotes a screen as “display medium”. The liquid crystal light valve 1 is irradiated with blue light, the liquid crystal light valve 2 is irradiated with green light, and the liquid crystal light valve 3 is irradiated with red light by an illumination light source optical system (not shown). (Two-dimensionally modulated by the image displayed on the light valve) is synthesized by the cross-type dichroic prism 4 and enters the projection lens 5. The light emitted from the projection lens 5 combines the image information of the liquid crystal light valves 1, 2, and 3, combines the image information, and enlarges and displays the image on a screen 6 as a color image.
【０００３】このように、３板式液晶プロジェクタで
は、投射用レンズ５の縮小側に、液晶ライトバルブや
「プリズム等の色合成手段」が配置され、特に、投射用
レンズと液晶ライトバルブとの間に色合成手段を配備し
なければならないため、投射用レンズ５は「長いバック
フォーカス」を必要とする。また、液晶ライトバルブか
ら色合成手段４に入射する光束の角度が変化すると、そ
れに応じて、色合成手段の分光透過率も変化し、投影さ
れたカラー画像における各色の明るさが画角により変化
して見づらい画像になるので、投射用レンズ５は、主光
線の角度が縮小側で同じになるテレセントリックな性質
を持つことが好ましい。近来、テレビ放送のデジタル化
を迎え、また、一般家庭におけるテレビの大画面化の傾
向と相俟って、これに適した背面投射タイプの３板式液
晶リアプロジェクタの高い普及率が予想されている。こ
のような状況から、３板式液晶リアプロジェクタに対し
ては、さらなる投射距離の短縮化・大画面化の要望が強
く、投射用レンズに対し、投射距離短縮のための短焦点
化、高画角化、表示画質を確保するための高性能、さら
なるコンパクト化の要請が強まってきている。As described above, in the three-panel type liquid crystal projector, the liquid crystal light valve and the “color combining means such as a prism” are arranged on the reduction side of the projection lens 5, and in particular, between the projection lens and the liquid crystal light valve. Therefore, the projection lens 5 needs a “long back focus” because a color synthesizing means must be provided in the projection lens 5. When the angle of the light beam entering the color synthesizing means 4 from the liquid crystal light valve changes, the spectral transmittance of the color synthesizing means changes accordingly, and the brightness of each color in the projected color image changes according to the angle of view. Therefore, it is preferable that the projection lens 5 has a telecentric property in which the angle of the principal ray becomes the same on the reduction side. In recent years, television broadcasting has been digitized, and in conjunction with the trend toward larger television screens in ordinary households, a high penetration rate of rear projection type three-panel liquid crystal rear projectors suitable for this is expected. . Under these circumstances, there is a strong demand for a three-panel liquid crystal rear projector to further reduce the projection distance and enlarge the screen, and the projection lens requires a shorter focal length for shortening the projection distance and a higher angle of view. There is an increasing demand for higher performance and higher compactness in order to secure display quality.
【０００４】[0004]
【発明が解決しようとする課題】この発明は、上記要請
にこたえるべく、Ｆ値：２．４程度の明るさを有し、半
画角４５度以上の高画角でありながらも高い解像力を維
持し、色合成手段配備に必要な十分な長さのバックフォ
ーカスを持ち、高いテレセントリック性を有する投射用
レンズの実現を課題とする。この発明はまた、３板式液
晶リアプロジェクタ本体に、コンパクトに組み込むこと
のできるコンパクトな投射用レンズの実現を課題とす
る。SUMMARY OF THE INVENTION In order to meet the above demand, the present invention has a high F-number of about 2.4 and a high resolving power at a high angle of view of more than 45 degrees at a half angle of view. It is an object of the present invention to realize a projection lens having a high back-focus and a high telecentric property, which has a sufficient length of back focus required for maintaining the color combining means. Another object of the present invention is to realize a compact projection lens that can be compactly incorporated into a three-panel liquid crystal rear projector main body.
【０００５】[0005]
【課題を解決するための手段】この発明の投射用レンズ
は、図１に例示するように、拡大側（図１の左方）から
縮小側に向かって順次、第１レンズ群Ｉ〜第３レンズ群
IIIを配している。第１群Ｉは「負の屈折力」を持ち、
第２レンズ群IIと第３レンズ群IIIは「共に正の屈折
力」を持つ。従って、全体のパワー配分は「負・正・
正」である。第1レンズ群Ｉと第2レンズ群IIとの間には
「比較的長い間隔」を有する。第１群は「全て負レン
ズ」で構成され、第1レンズ群Ｉを構成するレンズの
内、最も縮小側のレンズが非球面を有する（請求項
１）。請求項１記載の投射用レンズはまた、第３レンズ
群IIIを構成するレンズの内の少なくとも１枚が非球面
を有することができる（請求項２）。上記請求項１また
は２記載の投射用レンズは、レンズ全系の焦点距離を
f、第１レンズ群の焦点距離をｆ１、第３レンズ群の焦
点距離をｆ３、上記第１レンズ群と前記第２レンズ群の
間の空気間隔をＤとするとき、これらが条件： （１） −２．７＜ｆ１／ｆ＜−２．０ （２） ２．２＜ｆ３／ｆ＜ ２．８ （３） ２．９＜ Ｄ／ｆ＜ ４．１ を満足することが好ましい（請求項３）。請求項１また
は２または３記載の投射用レンズはまた、第２レンズ群
IIを、負の屈折力を持つレンズＬ２Ａ（図１で、拡大側
のレンズ）と正の屈折力を持つレンズＬ２Ｂ（図１で、
縮小側のレンズ）とで構成し、レンズＬ２Ａのアッベ数
をレンズＬ２Ｂのアッベ数よりも大きくすることができ
る（請求項４）。As shown in FIG. 1, a projection lens according to the present invention includes a first lens unit I to a third lens unit sequentially from an enlargement side (left side in FIG. 1) to a reduction side. Lens group
III is arranged. The first group I has “negative refractive power”,
The second lens group II and the third lens group III have “both have positive refractive power”. Therefore, the overall power distribution is “negative / positive /
Positive ". There is a “relatively long interval” between the first lens group I and the second lens group II. The first group is composed of "all negative lenses", and among the lenses constituting the first lens group I, the lens closest to the reduction side has an aspherical surface (claim 1). In the projection lens according to the first aspect, at least one of the lenses constituting the third lens group III may have an aspherical surface (claim 2). The projection lens according to claim 1 or 2 has a focal length of the entire lens system.
f, the focal length of the first lens group is f1, the focal length of the third lens group is f3, and the air gap between the first lens group and the second lens group is D. -2.7 <f1 / f <-2.0 (2) 2.2 <f3 / f <2.8 (3) It is preferable that 2.9 <D / f <4.1 be satisfied (claim). Item 3). The projection lens according to claim 1, 2 or 3, further comprises a second lens group.
II, a lens L2A having a negative refractive power (a lens on the enlargement side in FIG. 1) and a lens L2B having a positive refractive power (in FIG. 1,
(The lens on the reduction side), and the Abbe number of the lens L2A can be made larger than the Abbe number of the lens L2B.
【０００６】上記請求項１〜４の任意の１に記載の投射
用レンズにおいては、第３レンズ群IIIの拡大側の焦点
位置近傍に、開口絞りＳＴを配置することができる（請
求項５）。請求項６記載の投射用レンズは、上記請求項
１〜５の任意の１に記載の投射用レンズにおいて、第１
レンズ群と第２レンズ群の間に「光路を曲げるための反
射手段」を配置したことを特徴とする。In the projection lens according to any one of the first to fourth aspects, an aperture stop ST can be arranged near the focal position on the enlargement side of the third lens group III (claim 5). . The projection lens according to claim 6 is the projection lens according to any one of claims 1 to 5, wherein
"Reflecting means for bending the optical path" is disposed between the lens group and the second lens group.
【０００７】この発明の投射用レンズは、長いバックフ
ォーカスと、高いテレセントリック性を持たせるため、
拡大側から負の屈折力を持つ第１レンズ群Ｉ、正の屈折
力を持つ第２レンズ群II、正の屈折力を持つ第３レンズ
群IIIの、３群構成とし、屈折力の分布を「負・正・
正」とすることにより、拡大側が負で縮小側が正の「基
本的なレトロフォーカス型レンズ」とし、第1レンズ群
Ｉと第2レンズ群IIの間に、比較的長い間隔を配してい
る。第１・第２レンズ群間のこの「比較的長い間隔」に
は、請求項６記載の投射用レンズのように「光路を折り
曲げるミラー手段」を配置することができ、また必要に
応じて「有害な光線をカットする光学フィルター」等の
光学系を配置することができる。第１，第２レンズ群間
に「比較的長い間隔」を配すると、第１レンズ群の外径
が大きくなる傾向にあり、一般に行われている「レトロ
フォーカス型レンズの歪曲収差補正を担う正の屈折力の
レンズ」を配置する事が困難となる。そこで、第1レン
ズ群を全て負の屈折力のレンズで構成し、外径を小さく
すると共に、最も縮小側のレンズを非球面レンズとする
ことで、歪曲収差を適切に補正している。請求項２記載
の投射用レンズのように、第３群を構成するレンズの少
なくとも１枚に非球面を採用することによって、投射用
レンズの球面収差、非点収差を少ないレンズ枚数で補正
することが可能になる。The projection lens of the present invention has a long back focus and high telecentricity.
The first lens group I having a negative refractive power, the second lens group II having a positive refractive power, and the third lens group III having a positive refractive power have a three-group configuration from the enlargement side. "Negative / Positive /
By "positive", the enlargement side is negative and the reduction side is positive, so that it is a "basic retrofocus lens", and a relatively long distance is provided between the first lens group I and the second lens group II. . In this “relatively long interval” between the first and second lens groups, “mirror means for bending the optical path” can be arranged as in the projection lens according to claim 6. An optical system such as an “optical filter that cuts harmful light rays” can be arranged. If a “relatively long interval” is provided between the first and second lens groups, the outer diameter of the first lens group tends to increase, and the “positive correction for distortion of a retrofocus lens” that is generally performed is performed. It is difficult to arrange a lens having a refracting power. Therefore, the first lens group is composed of all lenses having negative refractive power, the outer diameter is reduced, and the lens on the most reduction side is an aspherical lens, so that distortion is appropriately corrected. The spherical aberration and astigmatism of the projection lens are corrected with a small number of lenses by adopting an aspheric surface for at least one of the lenses constituting the third group as in the projection lens according to claim 2. Becomes possible.
【０００８】請求項３記載の投射用レンズが満足する条
件（１）〜（３）のうち、条件（１）は、所望のバック
フォーカスと良好な光学性能を得る為の条件である。条
件（１）の下限を超えると、第１レンズ群の負の屈折力
が小さくなって「レトロフォーカス性」が弱くなり、コ
ンパクト性を保ちつつ、所望のバックフォーカスを確保
するのが困難になる。条件（１）の上限を超えると、第
１レンズ群の負の屈折力が過大になり、コマ収差、像面
湾曲等の軸外収差を良好に保つのが困難になる。条件
（２）は、高いテレセントリック性と所望のバックフォ
ーカスを得る為の条件である。条件（２）の下限を超え
ると、第３レンズ群の屈折力が大きくなり、軸外の主光
線が大きく曲げられてテレセントリック性が損なわれる
とともに、第１レンズ群と第２レンズ群の間に「所望の
間隔」を確保することが困難になる。条件（２）の上限
を超えると、第３レンズ群の屈折力が小さくなり、それ
に応じて第１レンズ群の屈折力も小さくしなければなら
なくなり、第１レンズ群と第２レンズ群の間隔が広が
り、第１レンズ群が大型化する。条件（３）は、第1レ
ンズ群と第2レンズ群の間に、前述の「光路を折り曲げ
る反射手段」等を適切に配置できるようにする為の条件
式であるが、上限を超えると、投射用レンズの全長が長
大化し、第１レンズ群の外径も大きくなってコンパクト
性の確保が困難になる。条件（３）の下限を超えると、
第1レンズ群と第2レンズ群の間に「所望の空気間隔」を
確保することが困難になる。また、所望のバックフォー
カスを得ようとすると、第1レンズ群の負の屈折力、第
３レンズ群の正の屈折力を共に大きくしなければなら
ず、このようにすると球面収差・コマ収差等の収差が悪
化する。[0008] Of the conditions (1) to (3) satisfied by the projection lens according to the third aspect, the condition (1) is a condition for obtaining a desired back focus and good optical performance. If the lower limit of the condition (1) is exceeded, the negative refracting power of the first lens group becomes small, and the "retro focus property" becomes weak, and it becomes difficult to secure a desired back focus while maintaining compactness. . When the value exceeds the upper limit of the condition (1), the negative refractive power of the first lens unit becomes excessively large, and it becomes difficult to maintain good off-axis aberrations such as coma and curvature of field. Condition (2) is a condition for obtaining high telecentricity and a desired back focus. When the value exceeds the lower limit of the condition (2), the refractive power of the third lens unit becomes large, and the off-axis principal ray is largely bent to impair telecentricity, and between the first lens unit and the second lens unit. It becomes difficult to secure a “desired interval”. When the value exceeds the upper limit of the condition (2), the refractive power of the third lens unit decreases, and accordingly, the refractive power of the first lens unit also needs to decrease. Accordingly, the distance between the first lens unit and the second lens unit decreases. The first lens group expands. The condition (3) is a conditional expression for appropriately disposing the above-mentioned “reflecting means for bending the optical path” between the first lens group and the second lens group. The overall length of the projection lens increases, and the outer diameter of the first lens group also increases, making it difficult to ensure compactness. When the value exceeds the lower limit of the condition (3),
It becomes difficult to secure a “desired air gap” between the first lens group and the second lens group. In order to obtain a desired back focus, both the negative refractive power of the first lens group and the positive refractive power of the third lens group must be increased. Becomes worse.
【０００９】請求項４記載の投射用レンズにおけるアッ
ベ数に対する条件は、投射用レンズのコンパクト性を保
ちつつ、軸上色収差を効果的に補正する条件である。前
述の如く、この発明の投射用レンズは、第1レンズ群と
第2レンズ群との間に比較的長い間隔を有する為、第1レ
ンズ群の外径が大きくなり易い。請求項４の条件を満足
することにより、「正の屈折力のレンズ」を第１レンズ
群内に配備することなく軸上色収差を補正でき、上記正
の屈折力のレンズを第１レンズ群中に配置することによ
る「外形の大型化」を防ぐことができる。請求項５記載
の投射用レンズのように、第３レンズ群の拡大側の焦点
位置近傍に「開口絞り」を配置することにより、高いテ
レセントリック性を確保すると共に、高い開口効率を実
現できる。また、請求項６記載の投射用レンズのよう
に、第1レンズ群と第2レンズ群との間に「光路を折り曲
げる反射手段」、例えば、ミラー、プリズム等を配置す
ることにより、投射用レンズのコンパクト性が計られる
とともに、３板式液晶リアプロジェクタ本体内のレイア
ウトの自由度も増し、本体をより小さくする事が可能と
なる。The condition for the Abbe number in the projection lens according to the fourth aspect is a condition for effectively correcting axial chromatic aberration while maintaining the compactness of the projection lens. As described above, since the projection lens of the present invention has a relatively long interval between the first lens group and the second lens group, the outer diameter of the first lens group is likely to be large. By satisfying the condition of claim 4, axial chromatic aberration can be corrected without disposing a “lens having a positive refractive power” in the first lens group, and the lens having a positive refractive power is included in the first lens group. In this case, it is possible to prevent "enlargement of the outer shape" caused by arranging the external shape. By arranging the "aperture stop" in the vicinity of the focal position on the enlargement side of the third lens group as in the projection lens according to the fifth aspect, high telecentricity can be ensured and high aperture efficiency can be realized. Further, as in the projection lens according to claim 6, a “reflection unit that bends the optical path”, for example, a mirror, a prism, or the like is disposed between the first lens group and the second lens group. And the degree of freedom in layout within the three-panel liquid crystal rear projector main body is increased, and the main body can be made smaller.
【００１０】なお、図１において、符号Ｐは「色合成手
段としての色合成プリズム」を示している。In FIG. 1, the symbol P indicates "color combining prism as color combining means".
【００１１】[0011]
【発明の実施の形態】以下、具体的な実施の形態とし
て、７実施例を挙げる。BEST MODE FOR CARRYING OUT THE INVENTION Seven specific examples will be described below.
【００１２】各実施例において、「Ｓ」により面（開口
絞りの絞り面、色合成プリズムの射出面・入射面を含
む）の番号（拡大側から数える）を表し、「Ｒ」により
各面の曲率半径（非球面にあっては近軸曲率半径）を表
し、「Ｄ」により光軸上の面間隔を表す。また、「Ｎ
ｄ」及び「νｄ」により、各レンズの材質の、ｄ線に対
する屈折率と、アッベ数を示す。また「ｆ」は投射用レ
ンズの焦点距離、「Ｆ／Ｎｏ」は明るさを表すＦ値、
「ω」は半画角、「ｂｆ」は空気中（プリズムのない状
態）のバックフォーカスを表す。非球面の形状は、光軸
との交点を原点とし、光軸に対する高さ：ｈ、光軸方向
の変移：Ｚ、近軸曲率：ｃ（前記近軸曲率半径の逆
数）、円錐定数：Ｋ、高次の非球面係数：Ａ，Ｂ，Ｃ，
Ｄ，Ｅとして、周知の式： Ｚ＝ｃ・ｈ2／[１＋√{１―（１＋Ｋ）・ｃ2・ｈ2}]＋
Ａ・ｈ4＋Ｂ・ｈ6＋Ｃ・ｈ8＋Ｄ・ｈ10＋Ｅ・ｈ12 で表す。In each of the embodiments, the number (counted from the enlargement side) of the surface (including the stop surface of the aperture stop, the exit surface and the entrance surface of the color combining prism) is represented by “S”, and “R” is assigned to each surface. A radius of curvature (a paraxial radius of curvature in the case of an aspherical surface) is shown, and "D" represents a surface interval on the optical axis. Also, "N
“d” and “νd” indicate the refractive index of the material of each lens with respect to the d-line and the Abbe number. Also, “f” is the focal length of the projection lens, “F / No” is the F value representing the brightness,
“Ω” indicates a half angle of view, and “bf” indicates a back focus in the air (without a prism). The aspherical shape has an origin at an intersection with the optical axis, height relative to the optical axis: h, displacement in the optical axis direction: Z, paraxial curvature: c (reciprocal of the paraxial curvature radius), conical constant: K , Higher order aspheric coefficients: A, B, C,
Well-known formulas as D and E: Z = c · h 2 / [1 + √ {1− (1 + K) · c 2 · h 2 }] +
A · h 4 + B · h 6 + C · h 8 + D · h 10 + E · h 12
【００１３】実施例１ 図２に、実施例１の投射用レンズのレンズ構成を示す。
拡大側（図の左側）から負の屈折力を持つ第１レンズ群
Ｉ、比較的長い間隔を隔てて正の屈折力を持つ第２レン
ズ群II、開口絞りＳＴ、正の屈折力を持つ第３レンズ群
III、プリズムＰからなっている。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.3度、ｂｆ＝39.15 Ｓ Ｒ Ｄ Ｎd νd 1 66.902 4.221 1.74330 49.2 2 43.849 4.950 3 51.710 4.380 1.65160 58.4 4 37.629 2.406 5 40.658 3.000 1.49154 57.8 6 19.115 60.550 7 51.921 6.189 1.58913 61.3 8 22.483 1.226 9 24.589 6.414 1.72825 28.3 10 426.090 4.079 11 ∞(絞り) 7.084 12 −66.842 6.544 1.69680 55.5 13 −33.906 0.300 14 −69.748 4.314 1.51680 64.2 15 −41.439 3.014 16 −23.134 3.820 1.80518 25.5 17 54.153 11.722 1.48749 70.4 18 −33.517 0.300 19 12053.791 7.939 1.62041 60.3 20 −57.912 0.300 21 74.688 11.264 1.58913 61.3 22 −89.772 0.320 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 非球面 第６面 K＝−0.723603，A＝0.490527×10-6，B＝−0.249556×10-9， C＝−0.260326×10-11，D＝0.478098×10-15，E＝−0.265872×10-17 条件式の値 （１）−2.47 （２） 2.41 （３） 3.50 図９に、実施例１の投射用レンズを縮小側で評価した収
差図を示す。基準波長は「５４６ｎｍのｅ線」としてい
る。非点収差図におけるＳはサジタル光線、Ｍはメリデ
ィオナル光線の場合を示している。他の収差図において
も同様である。Embodiment 1 FIG. 2 shows a lens configuration of a projection lens of Embodiment 1.
A first lens unit I having a negative refractive power, a second lens group II having a positive refractive power at a relatively long interval, an aperture stop ST, and a second lens unit having a positive refractive power from the magnifying side (left side in the figure). 3 lens groups
III, consisting of a prism P. f = 17.3, F / No = 2.4, ω = 45.3 degrees, bf = 39.15 SRD Nd νd 1 66.902 4.221 1.74330 49.2 2 43.849 4.950 3 51.710 4.380 1.65160 58.4 4 37.629 2.406 5 40.658 3.000 1.49154 57.8 6 19.115 60.550 7 51.921 6.189 1.58913 61.3 8 22.483 1.226 9 24.589 6.414 1.72825 28.3 10 426.090 4.079 11 絞 り (aperture) 7.084 12 −66.842 6.544 1.69680 55.5 13 −33.906 0.300 14 −69.748 4.314 1.51680 64.2 15 −41.439 3.014 16 −23.134 3.820 1.80518 25.5 17 54.153 11.722 1.48749 70.4 18 −33.517 0.300 19 12053.791 7.939 1.62041 60.3 20 −57.912 0.300 21 74.688 11.264 1.58913 61.3 22 −89.772 0.320 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 Aspheric surface 6th surface K = −0.723603, A = 0.490527 × 10 -6 , B = −0.249556 × 10 −9 , C = −0.260326 × 10 −11 , D = 0.478098 × 10 −15 , E = −0.265872 × 10 −17 Value of conditional expression (1) −2.47 (2) 2.41 (3) 3.50 FIG. 9 shows an aberration diagram of the projection lens of Example 1 evaluated on the reduction side. The reference wavelength is “e-line of 546 nm”. In the astigmatism diagram, S indicates a sagittal ray, and M indicates a meridional ray. The same applies to other aberration diagrams.
【００１４】実施例２ 図３に、実施例２の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.2度、ｂｆ＝39.14 Ｓ Ｒ Ｄ Ｎd νd 1 68.956 6.325 1.74330 49.2 2 46.642 6.304 3 57.293 4.517 1.65160 58.4 4 39.757 3.987 5 45.620 3.000 1.49154 57.8 6 20.137 69.200 7 48.692 5.753 1.58913 61.3 8 25.727 1.584 9 27.472 5.535 1.72825 28.3 10 347.349 4.302 11 ∞(絞り) 8.674 12 −91.822 4.562 1.69680 55.5 13 −38.396 0.506 14 −54.589 4.348 1.51680 64.2 15 −38.778 2.986 16 −23.491 5.030 1.80518 25.5 17 53.328 11.511 1.48749 70.4 18 −35.077 0.581 19 707.518 7.864 1.62041 60.3 20 −63.051 0.300 21 72.385 10.994 1.58913 61.3 22 −98.384 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 非球面 第６面 K＝−0.720194，A＝0.366381×10-7，B＝−0.689612×10-10， C＝−0.315017×10-11，D＝0.134922×10-14，E＝−0.201544×10-17 条件式の値 （１）−2.52 （２） 2.57 （３） 4.00 図１０に、実施例２の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 2 FIG. 3 shows a lens configuration of a projection lens according to Embodiment 2 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.2 degrees, bf = 39.14 S RD Nd νd 1 68.956 6.325 1.74330 49.2 2 46.642 6.304 3 57.293 4.517 1.65160 58.4 4 39.757 3.987 5 45.620 3.000 1.49154 57.8 6 20.137 69.200 7 48.692 5.753 1.58913 61.3 8 25.727 1.584 9 27.472 5.535 1.72825 28.3 10 347.349 4.302 11 絞 り (aperture) 8.674 12 −91.822 4.562 1.69680 55.5 13 −38.396 0.506 14 −54.589 4.348 1.51680 64.2 15 −38.778 2.986 16 −23.491 5.030 1.80518 25.5 17 53.328 11.511 1.487 18 −35.077 0.581 19 707.518 7.864 1.62041 60.3 20 −63.051 0.300 21 72.385 10.994 1.58913 61.3 22 −98.384 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 Aspheric surface 6th surface K = −0.720194, A = 0.366381 × 10 -7 , B = −0.689612 × 10 −10 , C = −0.315017 × 10 −11 , D = 0.134922 × 10 −14 , E = −0.201544 × 10 −17 Value of conditional expression (1) −2.52 (2) 2.57 (3) 4.00 FIG. 10 shows an aberration diagram of the projection lens of Example 2 evaluated on the reduction side.
【００１５】実施例３ 図４に、実施例３の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.4度、ｂｆ＝39.13 Ｓ Ｒ Ｄ Ｎd νd 1 66.098 4.785 1.74330 49.2 2 38.363 4.566 3 45.556 3.000 1.65160 58.4 4 33.819 4.080 5 40.294 3.334 1.49154 57.8 6 18.564 52.000 7 57.454 3.230 1.58913 61.3 8 35.014 0.300 9 34.456 8.000 1.72825 28.3 10 −654.715 8.038 11 ∞(絞り) 8.919 12 −72.783 4.965 1.69680 55.5 13 −27.545 0.300 14 −30.396 3.000 1.49154 57.8 15 −39.959 2.550 16 −27.301 3.007 1.80518 25.5 17 51.118 11.316 1.48749 70.4 18 −35.341 0.416 19 −234.604 7.903 1.62041 60.3 20 −47.795 0.300 21 179.708 12.285 1.58913 61.3 22 −48.569 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 非球面 第６面 K＝−0.759422，A＝−0.634822×10-7，B＝−0.259778×10-8， C＝−0.380183×10-11，D＝0.302099×10-14，E＝−0.809244×10-17 第１５面 K＝−2.47655，A＝0.945226×10-5，B＝0.550034×10-8， C＝−0.977880×10-11，D＝0.333603×10-12，E＝−0.139238×10-14 条件式の値 （１）−2.12 （２） 2.35 （３） 3.00 図１１に、実施例３の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 3 FIG. 4 shows a lens configuration of a projection lens according to Embodiment 3 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.4 degrees, bf = 39.13 SRD Nd νd 1 66.098 4.785 1.74330 49.2 2 38.363 4.566 3 45.556 3.000 1.65160 58.4 4 33.819 4.080 5 40.294 3.334 1.49154 57.8 6 18.564 52.000 7 57.454 3.230 1.58913 61.3 8 35.014 0.300 9 34.456 8.000 1.72825 28.3 10 −654.715 8.038 11 絞 り (aperture) 8.919 12 −72.783 4.965 1.69680 55.5 13 −27.545 0.300 14 −30.396 3.000 1.49154 57.8 15 −39.959 2.550 16 −27.301 3.007 1.80518 25.5 17 51.118 11.316 1.48749 70.4 18 −35.341 0.416 19 −234.604 7.903 1.62041 60.3 20 −47.795 0.300 21 179.708 12.285 1.58913 61.3 22 −48.569 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.784 Aspheric surface 6th surface K = −0.759422, A = −0.634822 × 10 -7 , B = −0.259778 × 10 −8 , C = −0.380183 × 10 −11 , D = 0.302099 × 10 −14 , E = −0.809244 × 10 −17 15th page K = −2.47655, A = 0.945226 × 10 −5 , B = 0.550034 × 10 -8, C = -0.977880 × 10 -11, D = 0.333603 × 10 -12, E = -0.139238 × 10 -14 condition value (1) -2.12 2) 2.35 (3) 3.00 11 illustrates aberration diagrams of the evaluation of the projection lens of Example 3 at the reduction side.
【００１６】実施例４ 図５に、実施例４の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.4度、ｂｆ＝39.15 Ｓ Ｒ Ｄ Ｎd νd 1 66.994 7.409 1.74330 49.2 2 40.705 5.616 3 50.784 3.277 1.65160 58.4 4 35.325 4.190 5 42.354 3.008 1.49154 57.8 6 18.904 25.900 7 ∞ 48.000 1.51680 64.2 8 ∞ 3.000 9 58.618 3.645 1.58913 61.3 10 40.115 0.300 11 38.321 5.664 1.72825 28.3 12 −403.765 6.515 13 ∞(絞り) 9.103 14 −71.692 4.640 1.69680 55.5 15 −31.434 0.898 16 −37.077 3.000 1.49154 57.8 17 −44.533 2.881 18 −28.706 3.000 1.80518 25.5 19 46.673 11.516 1.48749 70.4 20 −36.885 0.743 21 −337.090 8.000 1.62041 60.3 22 −52.676 0.702 23 179.639 12.563 1.58913 61.3 24 −48.841 0.300 25 ∞ 48.000 1.51680 64.2 26 ∞ 7.800 非球面 第６面 K＝−0.745055，A＝0.798626×10-7，B＝−0.163054×10-8， C＝−0.382532×10-11，D＝0.384170×10-14，E＝−0.692046×10-17 第１7面 K＝−2.194191，A＝0.905236×10-5，B＝0.730483×10-8， C＝−0.346268×10-10，D＝0.400363×10-12，E＝−0.139238×10-14 条件式の値 （１）−2.18 （２） 2.52 （３） 3.50 （Ｄの値は空気換算長＝60.55である。） 図１２に、実施例４の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 4 FIG. 5 shows a lens configuration of a projection lens of Embodiment 4 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.4 degrees, bf = 39.15 SRD Nd νd 1 66.994 7.409 1.74330 49.2 2 40.705 5.616 3 50.784 3.277 1.65160 58.4 4 35.325 4.190 5 42.354 3.008 1.49154 57.8 6 18.904 25.900 7 ∞ 48.000 1.51680 64.2 8 ∞ 3.000 9 58.618 3.645 1.58913 61.3 10 40.115 0.300 11 38.321 5.664 1.72825 28.3 12 −403.765 6.515 13 絞 り (aperture) 9.103 14 −71.692 4.640 1.69680 55.5 15 −31.434 0.898 16 −37.077 3.000 1.49154 57.8 17 −44.533 2.881 18 − 28.706 3.000 1.80518 25.5 19 46.673 11.516 1.48749 70.4 20 −36.885 0.743 21 −337.090 8.000 1.62041 60.3 22 −52.676 0.702 23 179.639 12.563 1.58913 61.3 24 −48.841 0.300 25 ∞ 48.000 1.51680 64.2 26 ∞ 7.800 Aspherical surface K = −0.745055, A = 0.798626 × 10 −7 , B = −0.163054 × 10 −8 , C = −0.382532 × 10 −11 , D = 0.384170 × 10 −14 , E = −0.692046 × 10 −17 17th surface K = −2.194191, A = 0.905236 × 10 -5 , B = 0.730483 × 10 -8 , C = −0.346268 × 10 -10 , D = 0.400363 × 10 -12 , E = −0.139238 × 10 − 14 Value of Conditional Expression (1) −2.18 (2) 2.52 (3) 3.50 (The value of D is air-equivalent length = 60.55.) FIG. 12 shows aberrations of the projection lens of Example 4 evaluated on the reduction side. The figure is shown.
【００１７】実施例５ 図６に、実施例５の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.4度、ｂｆ＝39.14 Ｓ Ｒ Ｄ Ｎd νd 1 66.488 8.000 1.74330 49.2 2 47.870 7.531 3 61.793 6.462 1.65160 58.4 4 38.762 8.490 5 59.360 3.000 1.49154 57.8 6 20.545 69.200 7 44.143 3.000 1.58913 61.3 8 38.298 0.904 9 43.999 5.444 1.72825 28.3 10 −560.804 7.071 11 ∞(絞り) 10.600 12 −58.212 4.279 1.69680 55.5 13 −33.544 0.300 14 −50.167 3.000 1.49154 57.8 15 −54.789 4.109 16 −31.231 3.000 1.80518 25.5 17 45.903 11.464 1.48749 70.4 18 −38.118 0.300 19 −596.426 7.152 1.62041 60.3 20 −60.290 1.528 21 144.782 12.379 1.58913 61.3 22 −50.721 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.780 非球面 第６面 K＝−0.733938，A＝−0.682613×10-6，B＝−0.115020×10-8， C＝−0.334012×10-11，D＝0.231678×10-14，E＝−0.248061×10-17 第１５面 K＝−1.632315，A＝0.860901×10-5，B＝0.769495×10-8， C＝−0.709000×10-10，D＝0.518172×10-12，E＝−0.139239×10-14 条件式の値 （１）−2.27 （２） 2.65 （３） 4.00 図１３に、実施例５の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 5 FIG. 6 shows a lens configuration of a projection lens according to Embodiment 5 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.4 degrees, bf = 39.14 SRD Nd νd 1 66.488 8.000 1.74330 49.2 2 47.870 7.531 3 61.793 6.462 1.65160 58.4 4 38.762 8.490 5 59.360 3.000 1.49154 57.8 6 20.545 69.200 7 44.143 3.000 1.58913 61.3 8 38.298 0.904 9 43.999 5.444 1.72825 28.3 10 −560.804 7.071 11 絞 り (aperture) 10.600 12 −58.212 4.279 1.69680 55.5 13 −33.544 0.300 14 −50.167 3.000 1.49154 57.8 15 −54.789 4.109 16 −31.231 3.000 1.80518 25.5 17 45.903 11.464 1.487 70.4 18 −38.118 0.300 19 −596.426 7.152 1.62041 60.3 20 −60.290 1.528 21 144.782 12.379 1.58913 61.3 22 −50.721 0.300 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.780 Aspheric surface 6th surface K = −0.733938, A = −0.682613 × 10 -6 , B = −0.115020 × 10 −8 , C = −0.334012 × 10 −11 , D = 0.231678 × 10 −14 , E = −0.248061 × 10 −17 15th surface K = −1.632315, A = 0.860901 × 10 −5 , B = 0.769495 x 10 -8 , C = -0.709000 x 10 -10 , D = 0.518172 x 10 -12 , E = -0.139239 x 10 -14 Value of conditional expression (1)-2.27 (2) 2.65 (3) 4.00 FIG. 13 shows an aberration diagram obtained by evaluating the projection lens of Example 5 on the reduction side.
【００１８】実施例６ 図７に、実施例６の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.2度、ｂｆ＝38.85 Ｓ Ｒ Ｄ Ｎd νd 1 71.512 8.000 1.74330 49.2 2 54.919 9.053 3 72.257 8.000 1.65160 58.4 4 43.630 6.875 5 55.452 7.345 1.49154 57.8 6 20.954 69.200 7 60.337 3.203 1.58913 61.3 8 27.005 1.806 9 27.288 6.215 1.72825 28.3 10 476.514 5.363 11 ∞(絞り) 9.690 12 −148.084 5.435 1.69680 55.5 13 −39.051 2.707 14 −25.111 6.576 1.80518 25.5 15 50.895 11.934 1.48749 70.4 16 −34.258 0.300 17 −1021.523 7.323 1.49154 57.8 18 −58.302 0.300 19 56.346 12.652 1.58913 61.3 20 −112.966 1.326 21 ∞ 48.000 1.51680 64.2 22 ∞ 7.784 非球面 第６面 K＝−0.726004，A＝−0.132647×10-6，B＝−0.101805×10-8， C＝−0.196352×10-11，D＝0.265319×10-14，E＝−0.240580×10-17 第１8面 K＝−0.440388，A＝0.367389×10-6，B＝−0.558733×10-9， C＝0.377645×10-12，D＝0.105239×10-14，E＝0.158780×10-18 条件式の値 （１）−2.59 （２） 2.55 （３） 4.00 図１４に、実施例６の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 6 FIG. 7 shows a lens configuration of a projection lens according to Embodiment 6 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.2 degrees, bf = 38.85 S RD Nd νd 1 71.512 8.000 1.74330 49.2 2 54.919 9.053 3 72.257 8.000 1.65160 58.4 4 43.630 6.875 5 55.452 7.345 1.49154 57.8 6 20.954 69.200 7 60.337 3.203 1.58913 61.3 8 27.005 1.806 9 27.288 6.215 1.72825 28.3 10 476.514 5.363 11 絞 り (aperture) 9.690 12 −148.084 5.435 1.69680 55.5 13 −39.051 2.707 14 −25.111 6.576 1.80518 25.5 15 50.895 11.934 1.48749 70.4 16 −34.258 0.300 17 −1021.523 7.323 1.49154 57.8 18 −58.302 0.300 19 56.346 12.652 1.58913 61.3 20 −112.966 1.326 21 ∞ 48.000 1.51680 64.2 22 ∞ 7.784 Aspheric surface 6th surface K = −0.726004, A = −0.132647 × 10 −6 , B = −0.101805 × 10 −8 , C = −0.196352 × 10 -11 , D = 0.265319 × 10 -14 , E = −0.240580 × 10 -17 Surface 18 K = −0.440388, A = 0.367389 × 10 -6 , B = −0.558733 × 10 -9 , C = 0.377645 × 10 -12 , D = 0.105239 × 10 -14 , E = 0.158780 × 10 -18 Value of the conditional expression (1) −2.59 (2) 2.55 (3) 4.00 FIG. FIG. 3 is an aberration diagram showing an evaluation of the projection lens on the reduction side.
【００１９】実施例７ 図８に、実施例７の投射用レンズのレンズ構成を、図２
に倣って示す。 f＝17.3、Ｆ／Ｎｏ＝2.4、ω＝45.6度、ｂｆ＝43.58 Ｓ Ｒ Ｄ Ｎd νd 1 73.386 5.500 1.72000 50.3 2 52.609 5.010 3 68.117 5.500 1.73400 51.1 4 39.481 4.864 5 50.658 5.000 1.49154 57.8 6 22.227 19.548 7 ∞ 48.000 1.51680 64.2 8 ∞ 2.122 9 166.871 4.323 1.48749 70.4 10 24.856 1.490 11 27.544 7.129 1.80518 25.5 12 −393.901 4.679 13 ∞(絞り) 6.518 14 −131.507 8.000 1.48749 70.4 15 −18.036 0.594 16 −17.687 5.740 1.80518 25.5 17 48.777 11.062 1.51680 64.2 18 −37.425 2.620 19 −983.469 8.306 1.49154 57.8 20 −46.434 0.329 21 178.975 12.469 1.65844 50.9 22 −52.287 5.000 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.540 非球面 第６面 K＝−0.615659，A＝−0.211762×10-5，B＝−0.300808×10-8， C＝−0.181833×10-11，D＝0.833522×10-15，E＝−0.198702×10-17 第１９面 K＝946.354967，A＝−0.376758×10-5，B＝0.149254×10-8， C＝−0.764429×10-12，D＝−0.217488×10-14，E＝0.220038×10-17 条件式の値 （１）−2.46 （２） 2.33 （３） 3.08 （Ｄの値は空気換算長＝53.32である。） 図１５に、実施例７の投射用レンズを縮小側で評価した
収差図を示す。Embodiment 7 FIG. 8 shows a lens configuration of a projection lens according to Embodiment 7 in FIG.
Shown after f = 17.3, F / No = 2.4, ω = 45.6 degrees, bf = 43.58 SRD Nd νd 1 73.386 5.500 1.72000 50.3 2 52.609 5.010 3 68.117 5.500 1.73400 51.1 4 39.481 4.864 5 50.658 5.000 1.49154 57.8 6 22.227 19.548 7 ∞ 48.000 1.51680 64.2 8 ∞ 2.122 9 166.871 4.323 1.48749 70.4 10 24.856 1.490 11 27.544 7.129 1.80518 25.5 12 −393.901 4.679 13 ∞ (Aperture) 6.518 14 −131.507 8.000 1.48749 70.4 15 −18.036 0.594 16 −17.687 5.740 1.80518 25.5 17 48.777 11.062 1.51680 64.2 18 −37.425 2.620 19 −983.469 8.306 1.49154 57.8 20 −46.434 0.329 21 178.975 12.469 1.65844 50.9 22 −52.287 5.000 23 ∞ 48.000 1.51680 64.2 24 ∞ 7.540 Aspheric surface 6th surface K = −0.615659, A = −0.211762 × 10 -5 , B = −0.300808 × 10 −8 , C = −0.181833 × 10 −11 , D = 0.833522 × 10 −15 , E = −0.198702 × 10 −17 Page 19 K = 946.354967, A = −0.376758 × 10 −5 , B = 0.149254 × 10 -8, C = -0.764429 × 10 -12, D = -0.217488 × 10 -14, E = 0.220038 × 10 -17 condition value (1) -2.46 (2 2.33 (3) 3.08 (D value is air equivalent length = 53.32.) Figure 15 shows aberration diagrams of the evaluation of the projection lens of Example 7 in the reduction side.
【００２０】上記実施例４と７とは、投射用レンズの第
１レンズ群と第２レンズ群の間に、プリズムを挿入した
例である。第１レンズ群と第２レンズ群の機構的な間隔
を一定に保つ条件下であれば、プリズムを挿入すること
により光学的な長さが短くなるので、第１レンズ群の外
径を小さくできるのでコンパクト性に有利となる。図１
６は、実施例５の投射用レンズの、第１レンズ群Ｉと第
２レンズ群IIの間に、反射手段として平面反射ミラーＭ
を配置した例である。実施例１，２，３，６の投射用レ
ンズも、同様に、第１レンズ群と第２レンズ群の間に平
面反射ミラーＭを配置することが可能である。図１７
は、実施例４の投射用レンズの第１レンズ群と第２レン
ズ群の間のプリズムを、反射面を持つプリズムＲＰにし
た例である。実施例７の投射用レンズも同様に、反射面
を持つプリズムＲＰにすることが可能である。このよう
に光路を自由に曲げることにより、投射用レンズのコン
パクト性が向上し、３板式液晶リアプロジェクタ本体内
のレイアウトの自由度が増し、本体そのものもコンパク
トにする事が可能になる。Embodiments 4 and 7 are examples in which a prism is inserted between the first lens unit and the second lens unit of the projection lens. Under the condition that the mechanical distance between the first lens group and the second lens group is kept constant, the optical length becomes shorter by inserting the prism, so that the outer diameter of the first lens group can be reduced. This is advantageous for compactness. FIG.
Reference numeral 6 denotes a plane reflecting mirror M as a reflecting means between the first lens group I and the second lens group II of the projection lens of the fifth embodiment.
Is an example in which. Similarly, in the projection lenses of the first, second, third, and sixth embodiments, the plane reflection mirror M can be disposed between the first lens group and the second lens group. FIG.
Is an example in which the prism between the first lens group and the second lens group of the projection lens of Example 4 is a prism RP having a reflecting surface. Similarly, the projection lens of the seventh embodiment can be a prism RP having a reflecting surface. By freely bending the optical path in this manner, the compactness of the projection lens is improved, the degree of freedom in layout within the three-panel liquid crystal rear projector main body is increased, and the main body itself can be made compact.
【００２１】各収差図に示されるように、本発明による
投射用レンズは、各実施例とも、高い光学性能を持って
いる。As shown in the aberration diagrams, the projection lens according to the present invention has high optical performance in each embodiment.
【００２２】上に挙げた実施例１〜７の投射用レンズは
何れも、拡大側から縮小側に向かって、負の屈折力を持
つ第1レンズ群Ｉ、正の屈折力を持つ第２レンズ群II、
正の屈折力を持つ第３レンズ群IIIを配し、第１レンズ
群Ｉと第２レンズ群II間に比較的長い間隔を有し、第１
レンズ群Ｉは全て負レンズで構成され、第１レンズ群の
内、最も縮小側のレンズが非球面（第６面）を有する
（請求項１）。また、実施例３〜７は何れも、第３レン
ズ群を構成するレンズの内、少なくとも１枚が非球面
（実施例３では第１５面、実施例４では第１７面、実施
例５では第１５面、実施例６では第１８面、実施例７で
は第１９面）を有する（請求項２）。また、実施例１〜
７の投射用レンズは何れも、レンズ全系の焦点距離：
f、第１レンズ群の焦点距離：ｆ１、第３レンズ群の焦
点距離：ｆ３、第１レンズ群と第２レンズ群の間の空気
間隔：Ｄが、条件： （１） −２．７＜ｆ１／ｆ＜−２．０ （２） ２．２＜ｆ３／ｆ＜ ２．８ （３） ２．９＜ Ｄ／ｆ＜ ４．１ を満足する（請求項３）。また、各実施例とも、第２レ
ンズ群は、負の屈折力を持つレンズＬ２Ａと正の屈折力
を持つレンズＬ２Ｂとで構成されており、レンズＬ２Ａ
のアッベ数がレンズＬ２Ｂのアッベ数よりも大きく（請
求項４）、第３レンズ群の拡大側の焦点位置近傍に開口
絞りＳＴが配置されている（請求項５）。また、図１６
に示すように、実施例５や実施例１，２，３，６の投射
用レンズの、第１レンズ群と第２レンズ群の間に、反射
手段として平面反射ミラーを配置でき、図１７に示すよ
うに、実施例４、７の投射用レンズの第１レンズ群と第
２レンズ群の間に、反射面を持つプリズムを配置するこ
とができる（請求項６）。Each of the projection lenses of Examples 1 to 7 above has a first lens unit I having a negative refractive power and a second lens having a positive refractive power from the enlargement side to the reduction side. Group II,
A third lens group III having a positive refractive power is disposed, and a relatively long distance is provided between the first lens group I and the second lens group II.
The lens unit I is composed of all negative lenses, and the lens closest to the reduction in the first lens unit has an aspherical surface (sixth surface). In all of Examples 3 to 7, at least one of the lenses constituting the third lens group is an aspheric surface (the 15th surface in the third embodiment, the 17th surface in the fourth embodiment, and the 17th surface in the fifth embodiment). 15 surface, the 18th surface in the sixth embodiment, and the 19th surface in the seventh embodiment). Further, Examples 1 to
Each of the projection lenses 7 has a focal length of the entire lens system:
f, the focal length of the first lens group: f1, the focal length of the third lens group: f3, and the air gap between the first lens group and the second lens group: D, provided that: (1) -2.7 < f1 / f <−2.0 (2) 2.2 <f3 / f <2.8 (3) 2.9 <D / f <4.1 is satisfied (claim 3). In each embodiment, the second lens group includes a lens L2A having a negative refractive power and a lens L2B having a positive refractive power.
Is larger than the Abbe number of the lens L2B (Claim 4), and the aperture stop ST is arranged near the focal position on the enlargement side of the third lens group (Claim 5). FIG.
As shown in FIG. 17, a plane reflecting mirror can be arranged as a reflection means between the first lens group and the second lens group in the projection lenses of the fifth and the first, second, third and sixth embodiments. As shown, a prism having a reflecting surface can be arranged between the first lens group and the second lens group of the projection lenses of Examples 4 and 7 (claim 6).
【００２３】[0023]
【発明の効果】以上に説明したように、この発明によれ
ば、Ｆ値２．４程度の明るさ、半画角４５度以上の高画
角でありながらも高い解像力を維持し、十分な長さのバ
ックフォーカス、高いテレセントリック性、コンパクト
性を有する投射用レンズを実現できる。特に、この発明
の投射用レンズを３板式液晶リアプロジェクタに搭載す
ることにより、プロジェクタ本体をコンパクト化するこ
とができ、高画角、大画面でありながらも、明るく、質
の高い映像を実現することが可能となる。As described above, according to the present invention, it is possible to maintain a high resolving power despite maintaining a high F-number of about 2.4 and a high angle of view of at least a half angle of view of 45 degrees. A projection lens having a long back focus, high telecentricity, and compactness can be realized. In particular, by mounting the projection lens of the present invention on a three-panel liquid crystal rear projector, it is possible to reduce the size of the projector body, and realize a bright, high-quality image despite having a large angle of view and a large screen. It becomes possible.
【図１】本発明の投射用レンズを説明する図である。FIG. 1 is a diagram illustrating a projection lens of the present invention.
【図２】実施例１のレンズ構成を示す図である。FIG. 2 is a diagram illustrating a lens configuration according to a first exemplary embodiment.
【図３】実施例２のレンズ構成を示す図である。FIG. 3 is a diagram illustrating a lens configuration according to a second embodiment.
【図４】実施例３のレンズ構成を示す図である。FIG. 4 is a diagram illustrating a lens configuration according to a third embodiment.
【図５】実施例４のレンズ構成を示す図である。FIG. 5 is a diagram illustrating a lens configuration of a fourth embodiment.
【図６】実施例５のレンズ構成を示す図である。FIG. 6 is a diagram showing a lens configuration of a fifth embodiment.
【図７】実施例６のレンズ構成を示す図である。FIG. 7 is a diagram illustrating a lens configuration according to a sixth embodiment.
【図８】実施例７のレンズ構成を示す図である。FIG. 8 is a diagram showing a lens configuration of a seventh embodiment.
【図９】実施例１に関する収差図である。FIG. 9 is an aberration diagram relating to Example 1.
【図１０】実施例２に関する収差図である。FIG. 10 is an aberration diagram relating to Example 2.
【図１１】実施例３に関する収差図である。FIG. 11 is an aberration diagram relating to Example 3.
【図１２】実施例４に関する収差図である。FIG. 12 is an aberration diagram relating to Example 4.
【図１３】実施例５に関する収差図である。FIG. 13 is an aberration diagram relating to Example 5.
【図１４】実施例６に関する収差図である。FIG. 14 is an aberration diagram relating to Example 6.
【図１５】実施例７に関する収差図である。FIG. 15 is an aberration diagram relating to Example 7.
【図１６】実施例５のレンズ構成で、別の形態を示す図
である。FIG. 16 is a diagram showing another configuration of the lens configuration of the fifth embodiment.
【図１７】実施例４のレンズ構成で、別の形態を示す図
である。FIG. 17 is a diagram illustrating another configuration of the lens configuration of the fourth embodiment.
【図１８】３板式液晶リアプロジェクタの色合成系以降
の説明図である。FIG. 18 is an explanatory diagram of a three-panel type liquid crystal rear projector after a color synthesizing system.
Ｉ 第１レンズ群 II 第２レンズ群 III 第３レンズ群 ＳＴ 絞り Ｐ クロス型ダイクロイックプリズム（色合成プリズ
ム） Ｍ 平面反射ミラー ＲＰ 反射面を持つプリズムI First lens group II Second lens group III Third lens group ST Stop P Cross-type dichroic prism (color combining prism) M Planar reflecting mirror RP Prism having reflecting surface
Claims (6)
を持つ第1レンズ群、正の屈折力を持つ第２レンズ群、
正の屈折力を持つ第３レンズ群を配し、 上記第１レンズ群と上記第２レンズ群間に比較的長い間
隔を有し、 上記第１レンズ群は全て負レンズで構成され、第１レン
ズ群の内、最も縮小側のレンズが非球面を有することを
特徴とする投射用レンズ。A first lens group having a negative refractive power, a second lens group having a positive refractive power, from the enlargement side to the reduction side,
A third lens group having a positive refractive power is disposed, a relatively long distance is provided between the first lens group and the second lens group, and the first lens group is entirely constituted by a negative lens; A projection lens, wherein the lens on the most reduction side in the lens group has an aspherical surface.
非球面を有することを特徴とする投射用レンズ。2. The projection lens according to claim 1, wherein at least one of the lenses constituting the third lens group has an aspherical surface.
いて、 レンズ全系の焦点距離をf、第１レンズ群の焦点距離を
ｆ１、第３レンズ群の焦点距離をｆ３、上記第１レンズ
群と上記第２レンズ群の間の空気間隔をＤとするとき、
これらが条件： （１） −２．７＜ｆ１／ｆ＜−２．０ （２） ２．２＜ｆ３／ｆ＜ ２．８ （３） ２．９＜ Ｄ／ｆ＜ ４．１ を満足することを特徴とする投射用レンズ。3. The projection lens according to claim 1, wherein the focal length of the entire lens system is f, the focal length of the first lens unit is f1, the focal length of the third lens unit is f3, and the first lens is a lens. Assuming that the air gap between the group and the second lens group is D,
These satisfy the following conditions: (1) -2.7 <f1 / f <-2.0 (2) 2.2 <f3 / f <2.8 (3) 2.9 <D / f <4.1 A projection lens.
ンズにおいて、 第２レンズ群が、負の屈折力を持つレンズＬ２Ａと正の
屈折力を持つレンズＬ２Ｂとで構成されており、レンズ
Ｌ２Ａのアッベ数がレンズＬ２Ｂのアッベ数よりも大き
いことを特徴とする投射用レンズ。4. The projection lens according to claim 1, wherein the second lens group includes a lens L2A having a negative refractive power and a lens L2B having a positive refractive power. A projection lens, wherein the Abbe number of L2A is larger than the Abbe number of lens L2B.
ンズにおいて、 第３レンズ群の拡大側の焦点位置近傍に、開口絞りが配
置されたことを特徴とする投射用レンズ。5. The projection lens according to claim 1, wherein an aperture stop is arranged near a focal position on the enlargement side of the third lens group.
ンズにおいて、 第１レンズ群と第２レンズ群の間に、光路を曲げるため
の反射手段が配置されたことを特徴とする投射用レン
ズ。6. A projection lens according to claim 1, wherein a reflecting means for bending an optical path is arranged between the first lens group and the second lens group. Projection lens.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29839999A JP4532630B2 (en) | 1999-10-20 | 1999-10-20 | Projection lens |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29839999A JP4532630B2 (en) | 1999-10-20 | 1999-10-20 | Projection lens |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001116990A true JP2001116990A (en) | 2001-04-27 |
| JP4532630B2 JP4532630B2 (en) | 2010-08-25 |
Family
ID=17859209
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29839999A Expired - Fee Related JP4532630B2 (en) | 1999-10-20 | 1999-10-20 | Projection lens |
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| Country | Link |
|---|---|
| JP (1) | JP4532630B2 (en) |
Cited By (8)
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|---|---|---|---|---|
| US7460307B2 (en) | 2004-05-17 | 2008-12-02 | Panasonic Corporation | Projector lens system |
| JP2010169885A (en) * | 2009-01-22 | 2010-08-05 | Ricoh Co Ltd | Image forming lens, camera device, and portable information terminal device |
| US8693109B2 (en) | 2011-10-11 | 2014-04-08 | Nittoh Kogaku K.K. | Projector lens system and projector apparatus |
| JP2017003775A (en) * | 2015-06-10 | 2017-01-05 | 株式会社リコー | Projection lens and image display device |
| JP2019192510A (en) * | 2018-04-26 | 2019-10-31 | 市光工業株式会社 | Vehicular lighting tool |
| JPWO2019163844A1 (en) * | 2018-02-21 | 2020-12-03 | 富士フイルム株式会社 | Optical unit and projection device |
| CN113219629A (en) * | 2021-04-28 | 2021-08-06 | 长光卫星技术有限公司 | Space light-emitting remote sensing optical lens |
| EP4137858A1 (en) * | 2021-08-17 | 2023-02-22 | Calin Technology Co., Ltd. | Optical imaging lens |
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| JPH08201688A (en) * | 1995-01-31 | 1996-08-09 | Mitsubishi Electric Corp | Retrofocus type lens and multivision projection type display device |
| JPH0996759A (en) * | 1995-09-28 | 1997-04-08 | Fuji Photo Optical Co Ltd | Retro-focus type lens |
| JP2000305012A (en) * | 1999-04-20 | 2000-11-02 | Minolta Co Ltd | Projection optical system |
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1999
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| JPH08201688A (en) * | 1995-01-31 | 1996-08-09 | Mitsubishi Electric Corp | Retrofocus type lens and multivision projection type display device |
| JPH0996759A (en) * | 1995-09-28 | 1997-04-08 | Fuji Photo Optical Co Ltd | Retro-focus type lens |
| JP2000305012A (en) * | 1999-04-20 | 2000-11-02 | Minolta Co Ltd | Projection optical system |
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7460307B2 (en) | 2004-05-17 | 2008-12-02 | Panasonic Corporation | Projector lens system |
| JP2010169885A (en) * | 2009-01-22 | 2010-08-05 | Ricoh Co Ltd | Image forming lens, camera device, and portable information terminal device |
| US8693109B2 (en) | 2011-10-11 | 2014-04-08 | Nittoh Kogaku K.K. | Projector lens system and projector apparatus |
| JP2017003775A (en) * | 2015-06-10 | 2017-01-05 | 株式会社リコー | Projection lens and image display device |
| JPWO2019163844A1 (en) * | 2018-02-21 | 2020-12-03 | 富士フイルム株式会社 | Optical unit and projection device |
| US11215907B2 (en) | 2018-02-21 | 2022-01-04 | Fujifilm Corporation | Optical unit and projection apparatus |
| JP6997854B2 (en) | 2018-02-21 | 2022-02-04 | 富士フイルム株式会社 | Optical unit and projection device |
| WO2019208559A1 (en) * | 2018-04-26 | 2019-10-31 | 市光工業株式会社 | Vehicle lamp |
| JP2019192510A (en) * | 2018-04-26 | 2019-10-31 | 市光工業株式会社 | Vehicular lighting tool |
| US11137125B2 (en) | 2018-04-26 | 2021-10-05 | Ichikoh Industries, Ltd. | Vehicle lamp |
| JP7151152B2 (en) | 2018-04-26 | 2022-10-12 | 市光工業株式会社 | vehicle lamp |
| CN113219629A (en) * | 2021-04-28 | 2021-08-06 | 长光卫星技术有限公司 | Space light-emitting remote sensing optical lens |
| EP4137858A1 (en) * | 2021-08-17 | 2023-02-22 | Calin Technology Co., Ltd. | Optical imaging lens |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4532630B2 (en) | 2010-08-25 |
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