201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種投影系統、投影屏幕及投影方 法，且特別是有關於一種可在外界環境光下提供良好影像 品質的投影系統、投影屏幕及投影方法。 . 【先前技術】 • 在一般的使用環境下，投影聚置所投射的影像會混入 環境光，而使得影像暗部細節亮度提高，進而導致視覺對 比大幅下降。在習知技術中，改善對比的方式有許多種， 以液晶顯示投影裝置為例，可藉由降低液晶顯示面板的開 口率(Aperture Rate)改善其暗態漏光的問題，進而增加液晶 顯示投影裝置的對比。 以數位光學處理(Digital Light Processing，DLP)投影裝置 為例’可藉由提高數位微反射鏡元件(Digital micr〇㈤耐 馨 iCe’DMD)表面的細腻度，而增加數位光學處理投影裝置其 ^射〜像的對比H採用上述方法所提升之影像對比 度均無法有效地弭平環境光所造成的影響。 【發明内容】 άτ* 此’本發明提供—種投影純及投影屏幕，其 界環境光下提供良好的影像品質。此外，本發明亦 出Γ 3投影方法’依此郷方法可在外界魏光下投射 出。α質良好的影像。 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 本發明提供一種投影系統，包括投影裝置及投影屏 幕。投影裝置適於提供具有第一偏振方向的影像光束。投 影屏幕配置於影像光束轉祕徑上。投料幕包括分光 式偏光元件、相位板以及投影板，其中來自投影裝置並具 有第-偏振方向的影像光束適於依序通過分光式偏光元件 與相位板而㈣至投影板。影像絲被投影板反射而通過 相位板後具有第二偏振方向，而具有第二偏振方向的影像 光束適於通過分光式偏光元件。 ^發崎供-缝财法，此投影枝包括下述步 私。提供具有第-偏振方向的影像光束。依序設置分光式 =元件、相位板以及投影板於具有第_偏振方向的影^象 光束的傳遞路控上，以使具有第一偏振方向的影 Ϊ ==影像光束被投影板反射一^ 於通件而具有第二偏振方向郷像光東適 -值供—歡料幕，此投與幕配置於具有第 式偏光元件、相位板以及投影 ^幕!括分先 ^板之-侧，而投影板相對:光=== 偏振方向的影像光束適於依序通過 办板反射而通過相位板後具有第二偏振方向=技 偏振^ Μ彡縣束雜通齡光錢光元件。 偏振方财’上狀第—偏財向與第二 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 在本發明之-實施例中，上述之第一偏振方向與第二 偏振方向為線偏振。 在本發明之-實施例中，上述之投影裝置包括照明系 ^、光閥、投影鏡頭以及投影偏光片m统適於提供 照明光束。糊配置於照明光束的傳遞路徑上，並適於將 =明光束轉換成影像絲。投影鏡頭配置於影像光束的傳 西於光閥與投影屏幕之間。投影偏光片適於 卢厂像光束或照明光束的傳遞路徑上，以使影像光 在傳遞至投影縣之前具有第-偏振方向。 在本發明之一實施例中，上述之投影偏光片配置於投 影鏡頭與投影屏幕之間 上述之投影偏光片配置於光 上述之投影偏光片配置於照 上述之投影偏光片包括多個 在本發明之一實施例中 閥與投影鏡頭之間。 在本發明之一實施例中 明系統與光閥之間。 在本發明之一實施例中—^ 個第二稜鏡柱以及多個偏光膜。多個第-魅文鏡柱交替排列。多個偏細分別配置於第 鏡^二稜鏡柱之間，並連接第—稜鏡柱與第二稜 ^ 本考x月之具施例中，上述之投影偏光片可進一步 ^括夕個相差則，相錢片分觀置於第二稜鏡柱之表 之-1發明之—實施财，上述之相差膜片分別為二分 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 在本發明之一實施财，上述之相位板為四分之 板。 又 ^本發明之-實施例t，上述之分光式偏光元件包括 的分光式偏光單元。每一分光式偏光單元具 稜鏡柱以及偏光膜’而偏光膜配置於 第一稜鏡柱與第二稜鏡柱之間。 施丄t發明之一實施财，提供具有第一偏振方向的影 像先束的方法包括下列步驟。首先，提供照明系統， 照明糸統適於提供照明光束。接著，設 ^ rfrr其中光闕適於將照明光束轉換成景= 束而後，δ又置投影鏡頭於影像光束的傳遞路徑上，201232151 PNAI-AC-0037-TWXX 36647twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to a projection system, a projection screen and a projection method, and in particular to an external environment A projection system, projection screen, and projection method that provide good image quality under light. [Prior Art] • In a normal use environment, the image projected by the projection overlay will be mixed with ambient light, which will increase the brightness of the details of the dark portion of the image, which will result in a sharp drop in visual contrast. In the prior art, there are many ways to improve the contrast. Taking the liquid crystal display projection device as an example, the problem of dark light leakage can be improved by reducing the aperture ratio of the liquid crystal display panel, thereby increasing the liquid crystal display projection device. Contrast. Taking a digital light processing (DLP) projection device as an example, the digital optical processing projection device can be increased by increasing the surface roughness of the digital micro mirror element (Digital micr〇 (5) 耐心iCe'DMD). The contrast of the image-image contrast H is improved by the above method, and the image contrast cannot be effectively flattened by the ambient light. SUMMARY OF THE INVENTION The present invention provides a projection-only and projection screen that provides good image quality under ambient light. In addition, the present invention also produces a projection method in which the projection method can be projected under ambient light. Good quality alpha image. 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n The present invention provides a projection system including a projection device and a projection screen. The projection device is adapted to provide an image beam having a first polarization direction. The projection screen is placed on the image beam path. The feeding screen comprises a spectroscopic polarizing element, a phase plate and a projection plate, wherein the image beam from the projection device having the first-polarization direction is adapted to sequentially pass the spectroscopic polarizing element and the phase plate and (4) to the projection plate. The image filament is reflected by the projection plate and passes through the phase plate to have a second polarization direction, and the image beam having the second polarization direction is adapted to pass through the spectroscopic polarization element. ^ 崎崎供-sewing method, this projection branch includes the following steps. An image beam having a first polarization direction is provided. The splitting mode component, the phase plate, and the projection plate are sequentially disposed on the transmission path of the image beam having the _ polarization direction so that the image having the first polarization direction == the image beam is reflected by the projection plate. In the case of the through-piece, there is a second polarization direction, such as a light-to-value-for-sales curtain, which is disposed on the side having the first type of polarizing element, the phase plate, and the projection screen; The projection plate is opposite: light === The image beam of the polarization direction is suitable for sequentially reflecting through the board and passing through the phase plate to have a second polarization direction = technical polarization. In the embodiment of the present invention, the first polarization direction and the second polarization direction are linear polarizations in the embodiment of the present invention. . In an embodiment of the invention, the projection apparatus described above includes an illumination system, a light valve, a projection lens, and a projection polarizer m adapted to provide an illumination beam. The paste is disposed on the transmission path of the illumination beam and is adapted to convert the = bright beam into a video filament. The projection lens is disposed between the light beam and the projection screen. The projection polarizer is adapted to the transmission path of the Luzhou image beam or the illumination beam such that the image light has a first-polarization direction before being transmitted to the projection county. In an embodiment of the present invention, the projection polarizer is disposed between the projection lens and the projection screen, and the projection polarizer is disposed on the light. The projection polarizer is disposed on the projection polarizer. In one embodiment between the valve and the projection lens. In an embodiment of the invention, between the system and the light valve. In one embodiment of the invention, a second mast and a plurality of polarizing films are provided. Multiple sympathetic columns are alternately arranged. a plurality of partial thicknesses are respectively arranged between the first mirror and the second prism, and are connected to the first column and the second edge. In the example of the test, the above-mentioned projection polarizer can further The difference is that the phase of the money is placed on the second column of the -1 invention - implementation of the financial, the above phase difference diaphragm is two points 201232151 PNAI-AC-0037-TWXX 36647twf.doc / n in the present invention One of the implementations, the above phase plate is a quarter board. Further, the present invention is the spectroscopic polarizing unit of the above-described spectroscopic polarizing element. Each of the splitting type polarizing units has a mast and a polarizing film', and the polarizing film is disposed between the first mast and the second mast. In one embodiment of the invention, the method of providing an image pre-beam having a first polarization direction comprises the following steps. First, an illumination system is provided, the illumination system being adapted to provide an illumination beam. Next, let r rrr, where the aperture is adapted to convert the illumination beam into a beam of view, and then δ is placed on the transmission path of the image beam.
投影鏡頭位於光_投料幕之間。料，設置投影偏I 片於配置於影像光束或照明光束的傳遞路徑上 光束在傳遞至投影屏幕之前具有第一偏振方向。使〜像 基於上述，在本發明之範例實施例中，上述之 統(或投影綠)可藉&上狀投料幕使部 ^離 開投影屏幕’而不易進人觀察者眼中。如此n 束投射至觀察者眼中的量便可 減少 者觀看到的投影影像對比度大幅地提高。換言 束存在㈣况仍旱有良好的投射影像品質。 為讓本發明之上述特徵和優點能更明 舉實施例，並配合所附圖式作詳細說明如下。下文特 【實施方式】 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 圖1為本發明一實施例之投影系統示意圖。圖2為本 發明一實施例之投影裝置示意圖。請同時參照圖丨及圖2, 本實施例之投影系統100包括投影裝置11〇及投影屏幕 120。本實施例之投影裝置110適於提供影像光束l，而影 像光束L具有第一偏振方向。 具體而言，本實施例之投影裝置110可包括照明夺統 112、投影鏡頭114、光閥116以及投影偏光片118。照明 鲁 糸統112適於提供照明光束1。光閥116配置於照明系統 112與投影鏡頭114之間’且位於照明光束1的傳遞路徑 上，以將照明光束1轉換為影像光束L。投影鏡頭1μ配 置於影像光束L的傳遞路徑上並位於光閥116與投影屏幕 120之間。在本實施例中，投影系統可包括有一投影偏光 片118 ’配置於照明系統112與投影屏幕12〇之間，且位 於影像光束L或照明光束1的傳遞路徑上，以使影像光束 L在傳遞至投影屏幕120之前具有第一偏振方向。更進一 步地說’本實施例之投影偏光片118可配置於投影鏡頭114 • 與投影屏幕120之間，以簡化投影裝置ι10的光學設計。 當然’在其他貫施例中’投影偏光片Η 8亦可配置於光間 116與投影鏡頭114之間、投影鏡頭Π4内部或照明系統 112與光閥116之間，其中本實施例是以投影偏光片118 設置於投影鏡頭114與投影屏幕12〇之間作為舉例說明， 但不限於此。在本貫施例中，光閥116例如為一數位微反 射鏡元件(Digital micro mirror device，DMD)。 在本實施例中，投影偏光片118例如為分光式偏光片 (beam splitting polarizer)，例如為圖3中所示。分光式偏光 7 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 片可包括有多個第一稜鏡柱118a、多個第二稜鏡柱U8b、 多個偏光膜118c以及多個相差膜片118d。具體而言，第 一稜鏡柱118a與第二稜鏡柱118b交替排列，而偏光膜 118c配置於第一棱鏡柱U8a與第二稜鏡柱丨丨肋之間並連 接第一稜鏡柱118a與第二稜鏡柱118b。另外，相差膜片 118d配置於第二稜鏡柱118b接近投影屏幕12〇之表面s 上，如圖3所示。在本實施例中，第一棱鏡柱U8a與第二 稜鏡柱118b例如是沿著y方向延伸的菱形柱。 在本實施例中’當來自光閥的影像光束L傳遞至投影 偏光片118的偏光膜U8c時，影像光束L會被分為沿著$ 方向線性偏振的第-影像光束L1及沿著χ方向線性偏振 的第二影像光束L2，而第二影像光束L2透過相差膜片 118d(例如二分之一波板)可將其偏振方向轉換為與第一、 像光束L1相同的偏振方向，如圖3所示。換言之，透過 相差膜片118d的使用，可使所有影像光束L皆可被轉= 為沿著y方向偏振的線性偏振光，進而可為後續段所 提及的投影屏幕120所充分利用。 圖4為圖i之投影屏幕局部放大示意圖。請同時泉昭 圖1及圖4，本實施例之投影屏幕120配置於具有第二偏' 振方向(例如沿著y方向線性偏振)的影像光束L的傳遞路 ，上。在本實施例中，投影屏幕120自遠離投影裝置110 的方向上依序包括分光式偏光元件122、相 投影板126。在本實施例中，分光式偏光元件m可2 多個陣列排列的分光式偏光單元122，(圖 偏光單元122,做為代表），其中每-分光式偏光=j 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 具有第一稜鏡柱122a(例如沿著y方向延伸的三角柱）、第 二棱鏡柱122b(例如沿著y方向延伸的三角柱）以及偏光膜 122c。偏光膜122c配置於第一稜鏡柱122a與第二稜鏡柱 122b之間，並連接第一稜鏡柱122a與第二稜鏡柱122b。 在本實施例中，相位板124例如為四分之一波板。另外， 本實施例之投影板126可用來承載分光式偏光元件122與 相位板124 ’因此本實施例之投影板126較佳的是採用硬 質基材。 具體而言，來自投影裝置11 〇並具有第一偏振方向（例 如沿著y方向線性偏振)的影像光束L會依序通過分光式偏 光元件122與相位板124而傳遞至投影板126，且影像光 束L被投影板126反射而通過相位板124後具有第二偏振 方向（例如沿著z方向線性偏振方向），而具有第二偏振方 向的影像光束L會通過分光式偏光元件122。在本實施例 中，當投影系統100於環境光束L’下進行晝面投影時，環 境光束L’中具有第一偏振方向(例如沿著y方向線性偏振) 的第一環境光束L1，會依序通過投影屏幕120之分光式偏 光元件122與相位板124而傳遞至投影板126，其中第一 環境光束L1’會被投影板126反射而通過相位板124後具 有第二偏振方向（例如沿著z方向線性偏振），且具有第二 偏振方向（例如沿著z方向線性偏振)的第一環境光束li， 便會通過分光式偏光元件122。 然而，由於分光式偏光元件122僅適於讓具有第一偏 振方向（例如沿著y方向線性偏振)之光線傳遞至投影板 126上，因此，環境光束L，中具有第二偏振方向(例如沿著 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n z方向線性偏振)的第二環境光束L2’便會被分光式偏光 元件122所反射而離開投影屏幕12〇，如圖4所示。換言 之，由於部分的環境光束L，僅(如：第二環境光束L2，& 被分光式偏光元件122所反射而無法傳遞至投影板上，而 僅有部伤的環i兄光束L’(即如：第一環境光束L1，)會進入 觀察者眼巾。如此-來’目此，環境光束L，賴射影像的 影響便可有效地被降低，進而可使得觀察者在環境光束L， 存在的情況下仍可享有良好的投射影像品質也就是說， 本^施例之投影系統1 〇 〇在進行畫面投影時便可有效地降 低環境光束L’投射至投影板126上的光強度，進而可呈現 高對比度投f彡晝面。具财說，純於傳絲_本實施 例=提出之概念的投料、統所呈_投影晝面之對比度， 本實施例之投影系統丨0 〇所呈現的投影畫面之對比 提升了 50%。 基於上述，本實施例亦提出一種投影方法適用於上述 的投影裝置11G及投影屏幕12G。此投影方法至少包括下 列步驟。首先’可利用前述的投影裝置11〇提供呈有第一 偏振方向的影像光束L。接著，可依序設置上述^ ί = 位板m以及投影板126於具有第-偏振 2=光束L的傳遞路徑上，以使具有第一偏振方向 =像光束L傳遞至投影板126上，並使影像光束l被投 衫板*126反射而通過相位板124後具有第二偏振方向，而 ^第二偏振方向的影像光束Lit於通過分光式偏光元件 122 〇 具體而言’當環境光束L’（包括具有第—偏振方向的 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n 第一環境光束Ll，以及具有第 ί夂二 偏振方向的第一環境光束以可於通過分 而傳遞至投影板ΐ26。具有第二偏振方 反射而The projection lens is located between the light_feed screens. The projection is set on the transmission path of the image beam or the illumination beam. The beam has a first polarization direction before being transmitted to the projection screen. Based on the above, in the exemplary embodiment of the present invention, the above-described system (or projection green) can be moved from the projection screen by the & The amount of projection of the n-beam into the viewer's eye can greatly reduce the contrast of the projected image viewed by the viewer. In other words, there is a good image quality in the presence of the beam (4). The above described features and advantages of the invention will be apparent from the following description. [Embodiment] 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n FIG. 1 is a schematic diagram of a projection system according to an embodiment of the present invention. 2 is a schematic view of a projection apparatus according to an embodiment of the present invention. Referring to FIG. 2 and FIG. 2 simultaneously, the projection system 100 of the present embodiment includes a projection device 11 and a projection screen 120. The projection device 110 of the present embodiment is adapted to provide an image beam l, and the image beam L has a first polarization direction. Specifically, the projection device 110 of the present embodiment may include an illumination system 112, a projection lens 114, a light valve 116, and a projection polarizer 118. Illumination Lu Xing 112 is adapted to provide an illumination beam 1. The light valve 116 is disposed between the illumination system 112 and the projection lens 114 and is located on the transmission path of the illumination beam 1 to convert the illumination beam 1 into the image beam L. The projection lens 1μ is disposed on the transmission path of the image beam L and is located between the light valve 116 and the projection screen 120. In this embodiment, the projection system may include a projection polarizer 118' disposed between the illumination system 112 and the projection screen 12A, and located on the transmission path of the image beam L or the illumination beam 1, so that the image beam L is transmitted. There is a first polarization direction before the projection screen 120. Further, the projection polarizer 118 of the present embodiment can be disposed between the projection lens 114 and the projection screen 120 to simplify the optical design of the projection device ι10. Of course, in other embodiments, the projection polarizer 8 can also be disposed between the light 116 and the projection lens 114, inside the projection lens 4 or between the illumination system 112 and the light valve 116, wherein the embodiment is a projection. The polarizer 118 is disposed between the projection lens 114 and the projection screen 12A as an example, but is not limited thereto. In the present embodiment, the light valve 116 is, for example, a digital micro mirror device (DMD). In the present embodiment, the projection polarizer 118 is, for example, a beam splitting polarizer, for example, as shown in FIG. Spectroscopic Polarization 7 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n The sheet may include a plurality of first masts 118a, a plurality of second masts U8b, a plurality of polarizing films 118c, and a plurality of phase difference diaphragms 118d. Specifically, the first mast 118a and the second mast 118b are alternately arranged, and the polarizing film 118c is disposed between the first prism post U8a and the second mast rib and connected to the first mast 118a. With the second mast 118b. In addition, the phase difference film 118d is disposed on the surface s of the second mast 118b close to the projection screen 12A, as shown in FIG. In the present embodiment, the first prism column U8a and the second mast 118b are, for example, rhombic columns extending in the y direction. In the present embodiment, when the image light beam L from the light valve is transmitted to the polarizing film U8c of the projection polarizer 118, the image light beam L is divided into the first image beam L1 linearly polarized along the direction and along the χ direction. The linearly polarized second image beam L2, and the second image beam L2 transmitted through the phase difference film 118d (for example, a half wave plate) can convert its polarization direction into the same polarization direction as the first image beam L1, as shown in the figure. 3 is shown. In other words, through the use of the phase difference film 118d, all of the image light beams L can be rotated = linearly polarized light polarized along the y direction, which can be fully utilized for the projection screen 120 mentioned in the subsequent paragraph. 4 is a partially enlarged schematic view of the projection screen of FIG. At the same time, in the first and fourth embodiments, the projection screen 120 of the present embodiment is disposed on the transmission path of the image light beam L having the second partial vibration direction (for example, linearly polarized along the y direction). In the present embodiment, the projection screen 120 includes the spectroscopic polarizing element 122 and the phase projection plate 126 in this order from the direction away from the projection device 110. In the present embodiment, the spectroscopic polarizing element m can be arranged in a plurality of arrays of spectroscopic polarizing units 122 (as shown by the polarizing unit 122), wherein each-spectral polarizing = j 201232151 PNAI-AC-0037- TWXX 36647twf.doc/n has a first mast 122a (eg, a triangular post extending in the y-direction), a second prism post 122b (eg, a triangular post extending in the y-direction), and a polarizing film 122c. The polarizing film 122c is disposed between the first mast 122a and the second mast 122b, and connects the first mast 122a and the second mast 122b. In the present embodiment, the phase plate 124 is, for example, a quarter-wave plate. In addition, the projection plate 126 of the embodiment can be used to carry the spectroscopic polarizing element 122 and the phase plate 124'. Therefore, the projection plate 126 of the embodiment preferably employs a rigid substrate. Specifically, the image light beam L from the projection device 11 having the first polarization direction (for example, linearly polarized along the y direction) is sequentially transmitted to the projection plate 126 through the spectral polarization element 122 and the phase plate 124, and the image The light beam L is reflected by the projection plate 126 and passes through the phase plate 124 to have a second polarization direction (for example, a linear polarization direction along the z direction), and the image light beam L having the second polarization direction passes through the spectral polarization element 122. In the present embodiment, when the projection system 100 performs a facet projection under the ambient light beam L', the first ambient light beam L1 having the first polarization direction (eg, linearly polarized along the y direction) in the ambient light beam L' The sequence is transmitted to the projection plate 126 through the splitting polarizing element 122 of the projection screen 120 and the phase plate 124, wherein the first ambient light beam L1' is reflected by the projection plate 126 and passes through the phase plate 124 to have a second polarization direction (eg, along The first ambient light beam li having a second polarization direction (e.g., linearly polarized along the z-direction) passes through the spectral polarizing element 122. However, since the spectroscopic polarizing element 122 is only adapted to transmit light having a first polarization direction (eg, linearly polarized along the y direction) onto the projection plate 126, the ambient light beam L has a second polarization direction (eg, along The second ambient light beam L2' of 201232151 PNAI-AC-0037-TWXX 36647twf.doc/nz direction linear polarization) is reflected by the spectroscopic polarizing element 122 away from the projection screen 12A, as shown in FIG. In other words, due to part of the ambient light beam L, only (eg, the second ambient light beam L2, & is reflected by the spectroscopic polarizing element 122 and cannot be transmitted to the projection plate, but only the wounded ring i brother beam L' ( For example, the first ambient light beam L1,) will enter the observer's eyeglasses. Thus, the effect of the ambient light beam L, the reflected image, can be effectively reduced, thereby allowing the observer to be in the ambient light beam L, In the case where there is still a good projected image quality, the projection system 1 of the present embodiment can effectively reduce the intensity of light projected onto the projection panel 126 by the ambient light beam L' when performing screen projection. In addition, it can present a high-contrast projection surface. It is said that it is purely silk--this embodiment = the concept of the proposed feeding, the contrast of the projection surface, the projection system of the embodiment 丨0 〇 The contrast of the projected projection image is increased by 50%. Based on the above, the present embodiment also proposes a projection method suitable for the above-described projection device 11G and projection screen 12G. The projection method includes at least the following steps. The projection device 11 〇 provides the image light beam L having the first polarization direction. Then, the above-mentioned ^ ί = position plate m and the projection plate 126 can be sequentially disposed on the transmission path having the first polarization 2 = light beam L so as to have The first polarization direction=image beam L is transmitted to the projection plate 126, and the image beam 1 is reflected by the shirtboard *126 and passes through the phase plate 124 to have a second polarization direction, and the image beam Lit of the second polarization direction is By the spectroscopic polarizing element 122 〇 specifically 'when the ambient light beam L' (including the 201232151 PNAI-AC-0037-TWXX 36647twf.doc/n first ambient light beam L1 having the first polarization direction, and having the second ambiguity The first ambient light beam of the direction is transmitted to the projection panel 26 by the partition. The second polarization side reflection
Tffi liL „ ^ 俠。之依上述之投影方法，部份的 衣f L (即第二環境光束L2，)便無法傳遞至 幕120。因此，環境光束L，對投嶋^ 二it 低’進而可使得觀察者享有品質較佳的 綜上所述，在本發明之範例實施例中，上述之 統(或投影方法)可藉由上述投影屏幕使部 = 而無法傳遞至投影板上，進而可使= 衣兄先束存在的情況仍享有良好的投射影像品質。也 雖然本發明已以較佳實施例揭露如上，然其並 明丄任何熟習此技藝者，在不脫離本發明之精神 i祀圍内’自可作些許之更動與潤飾，因此本發明之伴讀 範圍當視後附之申請專利範圍所界定者為準。 【圖式簡單說明】 圖1為本發明一實施例之投影系統示意圖。 圖2為本發明一實施例之投影裝置示意圖。 11 201232151 PNAI-AC-003 7-TWXX 36647twf.doc/n 圖3為本發明一實施例之投影偏光片示意圖。 圖4為圖1之投影屏幕局部放大示意圖。 【主要元件符號說明】 100 :投影系統 110 :投影裝置 112 :照明系統 114 :投影鏡頭 116 :光閥 118 :投影偏光片 118a、118b :稜鏡柱 118c :偏光膜 118d :相差膜片 120 :投影屏幕 122 :分光式偏光元件 122’ ：分光式偏光單元 122a、122b :稜鏡柱 124 :相位板 126 :投影板 S:棱鏡柱表面 X、y、z :方向 1 :照明光束 L、U、L2 :影像光束 L’、LI’、L2’ ：環境光束 12Tffi liL „ ^ 侠. According to the above projection method, part of the garment f L (ie the second ambient light beam L2) cannot be transmitted to the curtain 120. Therefore, the ambient light beam L is low on the throwing In the exemplary embodiment of the present invention, the above-mentioned system (or projection method) can be transmitted to the projection board by the above-mentioned projection screen, and thus can be transmitted to the projection board. The present invention has been shown to have a good projected image quality, and although the present invention has been disclosed in the preferred embodiments as described above, it will be apparent to those skilled in the art without departing from the spirit of the invention. The scope of the invention is defined by the scope of the appended patent application. FIG. 1 is a projection system according to an embodiment of the invention. 2 is a schematic view of a projection apparatus according to an embodiment of the present invention. 11 201232151 PNAI-AC-003 7-TWXX 36647twf.doc/n FIG. 3 is a schematic diagram of a projection polarizer according to an embodiment of the present invention. Partially enlarged projection screen [Main component symbol description] 100: Projection system 110: Projection device 112: illumination system 114: projection lens 116: light valve 118: projection polarizer 118a, 118b: mast 118c: polarizing film 118d: phase difference film 120: Projection screen 122: spectroscopic polarizing element 122': spectroscopic polarizing unit 122a, 122b: mast 124: phase plate 126: projection panel S: prism column surface X, y, z: direction 1: illumination beam L, U, L2: image beam L', LI', L2': ambient beam 12