JPH0463333A - Polarizing screen for liquid crystal projector - Google Patents

Polarizing screen for liquid crystal projector

Info

Publication number
JPH0463333A
JPH0463333A JP2123580A JP12358090A JPH0463333A JP H0463333 A JPH0463333 A JP H0463333A JP 2123580 A JP2123580 A JP 2123580A JP 12358090 A JP12358090 A JP 12358090A JP H0463333 A JPH0463333 A JP H0463333A
Authority
JP
Japan
Prior art keywords
liquid crystal
screen
crystal projector
light
polarizing
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.)
Pending
Application number
JP2123580A
Other languages
Japanese (ja)
Inventor
Masaharu Hara
原 政春
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Corp
Original Assignee
Sharp Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Priority to JP2123580A priority Critical patent/JPH0463333A/en
Publication of JPH0463333A publication Critical patent/JPH0463333A/en
Pending legal-status Critical Current

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  • Overhead Projectors And Projection Screens (AREA)

Abstract

PURPOSE:To obtain a high contrast image by arranging a polarizing plate having the same transmissivity curve as the wavelength characteristics of the three primary colors of a liquid crystal projector in the front of a screen, efficiently transmitting using light and reducing the transmission of unused light. CONSTITUTION:The ratio of brightness Ie of light emitted from the liquid crystal projector to external light Io on the polarizing screen 1 is IeXT<2>/IoXTX0.5XT =2.0XIe/Io. In this case, the transmissivity T of the external light is practically changed from that of the projector. Namely when the polarizing screen capable of transmitting only a spectra used for liquid crystal is used, the transmissibity of the external light is reduced and the contrast of an image on a bright position can be improved. When the polarizing plate 3 having transmissivity shown in the figure is stuck to the reflection face 2a of a screen main body 2 in the screen 1 for the liquid crystal projector, the transmission of the three primary colors R, G, B emitted from the projector is improved and that of other colors is deteriorated, so that a color reproducing range capable of reducing the influence of external light can be obtained.

Description

【発明の詳細な説明】 「産業上の利用分野」 この発明は、液晶プロジェクタ−用偏光スクリーンに関
し、特に、屋外や明るい屋内で見るときに有効な液晶プ
ロジェクタ−用偏光スクリーンに間する。
DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a polarizing screen for a liquid crystal projector, and particularly to a polarizing screen for a liquid crystal projector that is effective for viewing outdoors or indoors in bright light.

「従来の技術」 通常、液晶プロジェクタ−では、屋外や明るい屋内でも
ハイコントラスな画像を得るために偏光スクリーンが使
用される。
"Prior Art" Usually, a polarizing screen is used in a liquid crystal projector in order to obtain a high contrast image even outdoors or indoors in bright light.

そして、その偏光スクリーンは、液晶プロジェクタ−に
使用する原色の範囲と、使用しない波長域とが第3図で
示すようにフラットな分光透過率であるために、外光の
R,G、  B以外の光も良く反射透過していた。その
結果、液晶プロジェクタ−のコントラストを明るいとこ
ろでより悪くしていた。
The polarizing screen has a flat spectral transmittance between the range of primary colors used in the liquid crystal projector and the wavelength range not used, as shown in Figure 3. The light was reflected and transmitted well. As a result, the contrast of the liquid crystal projector becomes worse in bright areas.

「発明が解決しようとする課題」 液晶プロジェクタ−で偏光スクリーンを使用するのは、
屋外や明るい屋内等の状況下でもハイコントラスな画像
を得るためであるが、従来の技術で述べたように十分な
コントラスが得られなかった。
``Problem to be solved by the invention'' The use of a polarizing screen in a liquid crystal projector is
The purpose is to obtain high-contrast images even under conditions such as outdoors or brightly indoors, but as described in the related art, sufficient contrast could not be obtained.

その理由は、従来型の偏光板の透過率は、液晶プロジェ
クタ−自身の発光する光のスペクトルに関係なく設定さ
れているためてあり、光の利用効率が悪いためである。
The reason for this is that the transmittance of conventional polarizing plates is set regardless of the spectrum of light emitted by the liquid crystal projector itself, resulting in poor light utilization efficiency.

二の発明は、上記の点に鑑みてなされたもので、使用光
を良く透過し、不使用光を少なくすることによりハイコ
ントラスな画像を得ることができ、かつ、色再現性の範
囲も広くすることができる液晶プロジェクタ−用偏光ス
クリーンの提供を目的とする。
The second invention was made in view of the above points, and it is possible to obtain high-contrast images by transmitting used light well and reducing unused light, and also has a wide range of color reproducibility. An object of the present invention is to provide a polarizing screen for a liquid crystal projector that can be used for a liquid crystal projector.

「課題を解決するための手段」 上述の課題を解決するため、この発明においては、液晶
パネルの透過光を光学系により拡大投映する液晶プロジ
ェクタ−用偏光スクリーンにおいて、 液晶プロジェクタ−の3原色の波長特性と同一の透過率
曲線の偏光板をスクリーンの前面に配したことを特徴と
するものである。
"Means for Solving the Problems" In order to solve the above-mentioned problems, in the present invention, in a polarizing screen for a liquid crystal projector that enlarges and projects the transmitted light of a liquid crystal panel using an optical system, wavelengths of three primary colors of the liquid crystal projector are provided. The feature is that a polarizing plate with the same transmittance curve as the characteristics is placed in front of the screen.

「作 用」 偏光スクリーンlての外光Ioと液晶ブコジエクターの
発光する輝度1eとの比は、 IeXT”/IoXTX0.5XT となる。
"Function" The ratio between the external light Io of the polarizing screen l and the luminance 1e emitted from the liquid crystal display is IeXT''/IoXTX0.5XT.

このとき、外光の透過率Tを液晶プロジェクタ−の透過
率と実質的に変える。つまり、液晶で使用している分光
スペクトルのみ透過させる偏光スクリーンを使うことに
より、外光の透過率はより悪くなり、明るいところでコ
ントラストを高くすることができる。
At this time, the transmittance T of external light is substantially changed from the transmittance of the liquid crystal projector. In other words, by using a polarizing screen that transmits only the spectral spectrum used by the liquid crystal, the transmittance of external light becomes worse and contrast can be increased in bright areas.

「実 施 例」 続いて、この発明に係る液晶プロジェクタ−用偏光スク
リーンの実施の一例について、図面を参照して詳細に説
明する。
"Embodiment" Next, an embodiment of the polarizing screen for a liquid crystal projector according to the present invention will be described in detail with reference to the drawings.

第1図は、この発明に係る液晶ブaシエクター用偏光ス
クリーンの実施例を示す透過率曲線図である。
FIG. 1 is a transmittance curve diagram showing an embodiment of a polarizing screen for a liquid crystal display panel according to the present invention.

また、第2図はこの発明に係る液晶プロジェクタ−用偏
光スクリーンの機能図である。
Further, FIG. 2 is a functional diagram of a polarizing screen for a liquid crystal projector according to the present invention.

この第2図において、液晶プロジェクタ−用偏光スクリ
ーン(以下、単に偏光スクリーンと称す)1は、スクリ
ーン本体2の反射面2aに偏光板3が貼着されている。
In FIG. 2, a polarizing screen for a liquid crystal projector (hereinafter simply referred to as a polarizing screen) 1 has a polarizing plate 3 attached to a reflective surface 2a of a screen body 2. As shown in FIG.

そして、不定偏光波である外部光の輝度IOは、偏光ス
クリーン1に入射すると前面の偏光板3によってベクト
ルの50%が吸収され、さらに、偏光板3の透過率によ
ってもベクトルが減じられる。
When the brightness IO of the external light, which is an undefined polarized light wave, is incident on the polarizing screen 1, 50% of the vector is absorbed by the polarizing plate 3 on the front side, and the vector is further reduced by the transmittance of the polarizing plate 3.

その結果、スクリーン面で反射された光が偏光板3の特
性を示し、偏光板3による透過率で減じられて出射され
る。
As a result, the light reflected on the screen surface exhibits the characteristics of the polarizing plate 3, is reduced by the transmittance of the polarizing plate 3, and is emitted.

外部光の輝度(スクリーンに入射する光)I。Brightness of external light (light incident on the screen) I.

は、偏光スクリーン10反射面2aに反射され、液晶プ
ロジェクタ−の発光する光reと混色する。
is reflected by the reflective surface 2a of the polarizing screen 10 and mixed with the light re emitted from the liquid crystal projector.

その混色した光は、 I oXo、5XTXT=0.5T2r。The mixed color light is I oXo, 5XTXT=0.5T2r.

(透過率をT%とする) また、液晶プロジェクタ−から発する光Ieは、すでに
偏光波で偏光スクリーン1によって影響される光量は、
T2×Ieとなる。
(The transmittance is T%) Also, the light Ie emitted from the liquid crystal projector is already a polarized wave, and the amount of light affected by the polarizing screen 1 is:
It becomes T2×Ie.

よって、コントラストは、m a X輝度/ m i 
n輝度X100であるので、 出射光max(Io’+Ie’)/出射光min (I
o“+Ie“)となり、 To’=Io ″ =0.  5XT2XI。
Therefore, the contrast is m a X brightness/m i
Since n brightness is X100, output light max (Io'+Ie')/output light min (I
o“+Ie“), and To'=Io''=0.5XT2XI.

Ie’=IeXT Ie ″ =0 となり、 コントラスト比は、 となる。Ie’=IeXT Ie    =0 Then, The contrast ratio is becomes.

このとき、輝度のmaXとminとの比において、透過
率Tは関与しないものとなるが、色純度(色再現範囲)
において、液晶プロジェクタ−の発光スペクトルに合わ
せ第1図で示す透過率を持った偏光板3を使うと、液晶
プロジェクタ−から発せられる3原色R,G、  Bの
透過が良く、3原色以外は透過が悪くなり、外来光の影
響が少ない色再現範囲が得られる。
At this time, the transmittance T does not play a role in the ratio of luminance maX and min, but color purity (color reproduction range)
If a polarizing plate 3 with a transmittance shown in Fig. 1 is used in accordance with the emission spectrum of the liquid crystal projector, the three primary colors R, G, and B emitted from the liquid crystal projector will be transmitted well, and all other colors will be transmitted. This results in a color reproduction range that is less affected by external light.

「発明の効果」 以上のように、この発明に係る液晶プロジェクタ−用偏
光スクリーンは、偏光スクリーンの偏光板3を液晶プロ
ジェクタ−の3原色R,G、  Bが良く透過し、池の
波長範囲の透過を悪くしたものである。
"Effects of the Invention" As described above, in the polarizing screen for a liquid crystal projector according to the present invention, the three primary colors R, G, and B of the liquid crystal projector can be well transmitted through the polarizing plate 3 of the polarizing screen, and the polarizing screen for a liquid crystal projector according to the present invention can be used in a wavelength range of This makes the penetration worse.

従って、液晶プロジェクタ−を明るい状況下でもハイコ
ントラスで色純度の高い画像が得られる。
Therefore, images with high contrast and high color purity can be obtained even under bright conditions using the liquid crystal projector.

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

第1図はこの発明に係る液晶プロジェクタ−用偏光スク
リーンにおける偏光板の透過率曲線図、第2図は偏光ス
クリーンの機能図、第3図は従来の偏光板の透過率曲線
図である。  a O e ・偏光スクリーン ・反射面 ・偏光板 ・外光 ・液晶プロジェクタ−の出射光
FIG. 1 is a transmittance curve diagram of a polarizing plate in a polarizing screen for a liquid crystal projector according to the present invention, FIG. 2 is a functional diagram of the polarizing screen, and FIG. 3 is a transmittance curve diagram of a conventional polarizing plate. a O e ・Polarizing screen・Reflecting surface・Polarizing plate・Outside light・Emitted light from liquid crystal projector

Claims (1)

【特許請求の範囲】[Claims] (1)液晶パネルの透過光を光学系により拡大投映する
液晶プロジエクター用偏光スクリーンにおいて、 液晶プロジェクターの3原色の波長特性と同一又は近似
の透過率曲線の偏光板をスクリーンの前面に配したこと
を特徴とする液晶プロジェクター用偏光スクリーン。
(1) In a polarizing screen for a liquid crystal projector that magnifies and projects the transmitted light of the liquid crystal panel using an optical system, a polarizing plate with a transmittance curve that is the same or similar to the wavelength characteristics of the three primary colors of the liquid crystal projector is placed in front of the screen. A polarizing screen for LCD projectors featuring:
JP2123580A 1990-05-14 1990-05-14 Polarizing screen for liquid crystal projector Pending JPH0463333A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2123580A JPH0463333A (en) 1990-05-14 1990-05-14 Polarizing screen for liquid crystal projector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2123580A JPH0463333A (en) 1990-05-14 1990-05-14 Polarizing screen for liquid crystal projector

Publications (1)

Publication Number Publication Date
JPH0463333A true JPH0463333A (en) 1992-02-28

Family

ID=14864107

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2123580A Pending JPH0463333A (en) 1990-05-14 1990-05-14 Polarizing screen for liquid crystal projector

Country Status (1)

Country Link
JP (1) JPH0463333A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6765318B2 (en) 2001-03-26 2004-07-20 Fanuc Ltd. Linear driving device
CN101823633A (en) * 2010-04-28 2010-09-08 南京湘宝钛白制品实业有限公司 A kind of energy-saving automatic discharger and application
JP2011090256A (en) * 2009-10-26 2011-05-06 Nikon Corp Screen for projector and projection system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6765318B2 (en) 2001-03-26 2004-07-20 Fanuc Ltd. Linear driving device
JP2011090256A (en) * 2009-10-26 2011-05-06 Nikon Corp Screen for projector and projection system
CN101823633A (en) * 2010-04-28 2010-09-08 南京湘宝钛白制品实业有限公司 A kind of energy-saving automatic discharger and application

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