JPH0354593A - Projection type display device - Google Patents

Abstract

PURPOSE:To obtain a projection type display device with a bright screen in which brightness hardly lowers and the unevenness of brightness and the irregularity of color occur a little by arranging one or more convex lenses having plane parts in their central parts between a light source and a light valve. CONSTITUTION:Light emitted from the light source 5 is turned into the nearly collimated beam of light by a reflector 6 and made incident on the lenses 4-c to 4-a whose central parts are plane. Since the light leaking to a peripheral part is collected to the central part by the lenses, the light which is not utilized originally can be guided to the light valve 3. Furthermore, more light which is going to leak is incorporated inside by arranging many lenses whose central parts are plane at a proper distance apart, so that the effective utilization efficiency of the luminous flux emitted from the light source is improved and a bright video can be offered on a screen 1. Since the intensity distribution of the light becomes moderate in comparison with forcible prevention of scattering by a lens barrel, the high image quality with little unevenness of brightness and little irregularity of color is obtained.

Description

【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、ビデオ映像や、コンピューターグラフイ クス画像を表示する投写型表示装置に関する。[Detailed description of the invention] [Industrial application field] The present invention is applicable to video images and computer graphics. The present invention relates to a projection type display device that displays a screen image.

［従来の技Ｗｉ］ 従来の投写型表示装置は、光源から直接もしくは、周囲
へ発散しないように、鏡面筒で光を導く等の方法がとら
れていた。[Conventional Technique Wi] Conventional projection display devices have adopted a method such as guiding light directly from a light source or using a mirrored tube to prevent it from radiating into the surroundings.

［発明が解決しようとする課題］ しかし、前述の従来技術では、直接何もなくてライトパ
ルプへ照射すれば、周囲へ洩れが発生しスクリーン上の
輝度が低下し、周囲へ発散しないように鏡崩筒で光を導
くと、スクリーン上の特に周辺部に輝度ムラや色ムラが
発生するという問題点を有する。そこで本発明は、この
ような問題点を解決するもので、その目的とするところ
は、輝度の低下が少なく、明るい画面でなお且つ輝度ム
ラ色ムラの少ない投写表示画質の良い投写型表示装置を
提供するところにある。[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, if the light pulp is irradiated directly without anything, it will leak to the surroundings and the brightness on the screen will decrease. When light is guided by a collapsible tube, there is a problem in that uneven brightness and color occur on the screen, especially in the peripheral area. SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and its purpose is to provide a projection type display device that has a bright screen with little reduction in brightness, and has good projection display image quality with less uneven brightness and color. It's there to provide.

［課題を解決するための手段］ 本発明の投写型表示装置は、 （１）　光源から出射された略平行な光を強度変調する
ライトバルブ、該ライトバルプを通過した光をスクリー
ン上に拡大投写するレンズを有する投写型表示装置にお
いて、光源とライトパルプの間に中央部に平面部を有す
る凸レンズを一枚以上配したことをｌ＃徴とする。[Means for Solving the Problems] The projection display device of the present invention includes: (1) a light valve that modulates the intensity of substantially parallel light emitted from a light source; and enlarges and projects the light that has passed through the light valve onto a screen. In a projection type display device having a lens, one or more convex lenses having a flat portion in the center are disposed between the light source and the light pulp, which is referred to as an l# feature.

（２）　前記凸レンズの中央の平面部のかわりにレンズ
の曲率と異なる曲面部を中央に有することを特徴とする
。(2) Instead of the flat part at the center of the convex lens, the convex lens has a curved part at the center having a curvature different from that of the lens.

［実施例］ 第１図は、本発明の実施例における主要断面図であって
、光源から出射される光をリフレクターで略平行に出射
し、ライトバルプに至る前に中央部が平面もしくは曲率
半径の大きい曲面とした凸レンズを一枚以上挿入するこ
とにより、周辺部に洩れた光は凸レンズによ．り中央部
へ集められることにより、本来利用されない光をライト
バルブヘ導くことができる。第２図に示すように中央平
面もしくは曲率半径の大きな部分はライトバルブと同寸
法、同形状とすれば、非常に効果的に光を中央部にライ
トバルブ内へ導くことができる。さらに、上記中央部平
面レンズを適当な距離間隔で多数配列することにより、
より多くの洩れようとする光を内側へ取り込むことがで
きる。[Embodiment] Fig. 1 is a main cross-sectional view of an embodiment of the present invention, in which the light emitted from the light source is emitted approximately parallel to the reflector, and the central part is flat or has a radius of curvature before reaching the light bulb. By inserting one or more convex lenses with large curved surfaces, light leaking to the periphery can be absorbed by the convex lenses. By concentrating the light in the center, it is possible to guide light that would otherwise not be used to the light valve. As shown in FIG. 2, if the central plane or the portion with a large radius of curvature has the same size and shape as the light valve, light can be guided very effectively into the light valve at the center. Furthermore, by arranging a large number of the central plane lenses at appropriate distance intervals,
It allows more light that would otherwise leak into the interior.

［発明の効果コ 以上述べたように、本発明によれば、光源とライトバル
プの間に、中央部に平面部を有する凸レンズ群を挿入す
ることにより、周囲に散逸しようとする光を再び、中央
部へ導くことができ、光源の出射光束を有効利用効率が
良くなり、明るいスクリーン上の映像を提供することが
できるという効果を有する。また鏡筒による強制的な散
一防止に比して、ゆるやかな強度分布になるため輝度ム
ラや、色ムラの少ない高画質を提供できるという効果を
有する。[Effects of the Invention] As described above, according to the present invention, by inserting a convex lens group having a flat part in the center between the light source and the light bulb, light that would otherwise be scattered to the surroundings is redirected to the center. This has the effect that the luminous flux emitted from the light source can be efficiently utilized and a bright image on the screen can be provided. Furthermore, compared to forced scattering prevention using a lens barrel, the intensity distribution is gentler, so it has the effect of providing high image quality with less uneven brightness and color.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は、本発明の投写型表示装置の一実施例を示す主
要断面図。 第２図は、本発明の投写型表示装置の一実施例のレンズ
の光軸方向から見た平面図。 １・・・・・・・・・スクリーン ２・・・・・・・・・投写レンズ ３・・・・・・・・・ライトバルフ ４−α，４−ｈ，４−ｃ・・・・・・レンズ５・・・・
・・・・・光　源 ６・・・・・・・・・リフレクター ２１・・・・・・平面部 ２２・・・・・・球面レンズ部 以上FIG. 1 is a main sectional view showing an embodiment of a projection type display device of the present invention. FIG. 2 is a plan view of an embodiment of the projection display device of the present invention as viewed from the optical axis direction of the lens. 1...Screen 2...Projection lens 3...Light bulb 4-α, 4-h, 4-c...・Lens 5...
...Light source 6...Reflector 21...Flat section 22...Spherical lens section or higher

Claims (2)

【特許請求の範囲】[Claims] （１）光源から出射された略平行な光を強度変調するラ
イトバルブ、該ライトバルブを通過した光をスクリーン
上に拡大投写するレンズを有する投写型表示装置におい
て、光源とライトバルブの間に中央部に平面部を有する
凸レンズを一枚以上配したことを特徴とする投写型表示
装置。(1) In a projection display device that includes a light valve that modulates the intensity of substantially parallel light emitted from a light source and a lens that magnifies and projects the light that has passed through the light valve onto a screen, the center is located between the light source and the light valve. 1. A projection display device comprising one or more convex lenses each having a flat surface. （２）前記凸レンズの中央の平面部のかわりにレンズの
曲率と異なる曲面部を中央に有することを特徴とするこ
とを特徴とする請求項１記載の投写型表示装置。(2) The projection type display device according to claim 1, characterized in that the convex lens has a curved surface portion at the center with a curvature different from that of the lens instead of a flat surface portion at the center thereof.