200914875 九、發明說明： 【發明所屬之技術領域】 本發明關於一種投影光學系統，尤其係一種具有高 對比度之立體投影光學系統。 【先前技術】 近年來，圖像投影儀，尤其數位投影儀，作為向觀 眾顯示多種訊息之工具已經逐漸流行。一般，這些投影 儀用於將由電腦生成之圖像投影到螢幕上。對觀看者來 垅，圖像投景；^儀投影之圖像通常看起來係平面二維圖 像，除圖像本身外無法顯示任何圖像景深訊息。這種顯 不可以適用於顯示多種訊息。但是，在某些情況下，觀 看者希望能有比二維顯示能夠更大程度地顯示圖像之景 深或結構特徵之投影儀。 使二維顯示之圖像能給出圖像景深之一種方式係通 過立體地顯示圖像。立體圖像，通常稱為“三維，，或 3D圖像，在觀看者看來具有深度尺寸。這些圖像包 括分開的、疊合的左眼及右眼圖像，這些圖像設置成模 仿人之左右眼觀看時，由於人眼睛間隔引起之三維物體 表面之微小差別’而具有之景深圖像。左眼及右眼圖像 係這樣來顯示，即觀看者之右眼看不到左眼圖像，左眼 看不到右眼圖像。這種顯示方式一般借助於觀看者佩 之光學濾光鏡。 ” 通常顯示讀®像之方式錢用兩個分開之圖像投 影系統分別來投影左眼圖像及右眼圖像。而這種系統^ 200914875 成功地用於形成立體圖像之同時，系統之成本和重量則 比單個投影儀要高很多。而且，兩個投影儀要求光學對 準相對困難並比較費時。還有，由於這兩個系統之重量 及體積，使這種系統在兩個位置之間移動起來特別困 難，還有存在潛在之圖像對準之問題。 【發明内容】 有鑒於此，有必要提供一種能夠提高對比度之立體 投影光學系統。 一種立體投影光m其包括依光路設置之： 一圖像吸收n，用於接收人射光，對該人射光進行 調制並載人空間訊息，並出射經調制並載人有空間訊息 之偏振方向垂直之第—偏振光及第二偏振光； —一穿透式轴制器，設置於所述圖像吸收器出射之 射光路上’該穿透式光調制器具有開啟 個父替之工作狀態，該穿透式光調制器處於開 二述第一偏振光穿過所述穿透式光調制器， 處於截止狀態時，所述穿透式光調制 弟一偏振光調制為第二偏振光並出射。 制器輸人訊號使得該穿透式光 為牙透式先调 個交替之工作狀態，使得觀看有開啟及截止兩 同偏振狀態之影像，當該輪入訊=頻=不 看者之左右眼分別戴上檢偏方向;足夠= 片，就可以觀察到立體之圖像訊息。 兩片偏振 200914875 【實施方式】 :面將結合_，細下触實施例並配合圖式詳 細描述如下。 請參閱圖1及圖 ^ 2為本發明提供之第一實施例之立 光學系統100之結構示意圖。該立體投影光學孕 包括沿光路方向依次設置之-光源組件n、-圖 ::為12、一設置於所述圖像吸收器12出射光路上之 牙透式光調制器14以及—投影鏡頭15。 111 所述光源組件U包括依光路設置之—照明光源 一色輪112以及—積分器113。所述照明光源1U 發射^括顯不％色圖像所需之紅光⑻、綠光(G)及藍光⑻ 之白光該光源11可以為自素燈、金屬函化物燈、氣燈 或LED #。在本實施例中，該光源^為齒素燈。所述 色輪112包括紅、綠、藍三色區，其可在電機（圖未示） 的可動下间速旋轉’以給投影光路配以各種色彩。所述 積分器113用來均勻化及有效地使用光源11發出之光。 所述圖像吸收器12 &括依光路設置之-偏振分束器 121及一反射式空間光調制器122。所述偏振分束器 (Polarization Beam Splitter，PBS) 121 用於將來自光源元 件11之非偏振光變成第一偏振光及第二偏振光，在本實 施例中所第-偏振光為s偏振光，第二偏振光為p偏二 光。該S偏振光被該偏振分束器121反射，而p偏振光 透過該偏振分束器〗21。該偏振分束器121可以為金屬柵 格型偏振片（Wire Grid Polarizer，簡稱WGP偏振片），也 200914875 可以為偏振分光棱鏡，在本實施例中，該偏振分束器ΐ2ι 為偏振分光棱鏡。該偏振分束器121根據對s偏振光和p 偏振光之作用不同，可以分為反射s偏振光而透過？偏 振光，與透過S偏振光而反射p偏振光兩種形式。在本 實施例中，所述偏振分束器23反射s偏振光，而可以讓 P偏振光透過。 所述反射式空間光調制器122可以為矽基液晶 (Liquid Crystal on Silicon，LCoS)顯示面板。該矽基液晶 顯示面板工藝結構結合了液晶技術與半導體積體電路技 術。LCoS面板利用半導體製程製作驅動面板，然後在電 晶體上採用研磨技術磨平，並鍍上鋁或銀等當作反射 鏡，形成CMOS基板，再將CM〇S基板與含有透明電極 的玻璃基板貼全後灌入液晶分子並封裝測試，形成lc〇s 面板。L C 〇 S面板通過控制光的偏振狀態來調制入射光並 給入射光加入空間訊息，形成包括該入射光及該空間訊 息經過調制之出射光。所述空間訊息可以為該Lc〇s所載 入之控制訊號電壓，該控制訊號電壓直接控制薄膜電晶 體之開關狀態，再利用該薄膜電晶體來控制所述液晶分 子之偏轉狀態，而液晶分子具有明顯之光學各向異:: 能夠控制來自入射光之光線，從而實現為入射光載入圖 像訊號之目的。在本實施例中，該反射式空間光調制哭 122對S偏振光進行調制並載入空間訊息，並將經調制: 載入有空間§孔息之P偏振光反射出去，該p偏振光、 偏振分束器121並發射出去。 ° 200914875 所述穿透式光調制器14可以為液晶顯示裝置（Liquid Cry stal Dispaly，LCD)。通過為該穿透式光調制器14輸入 脈衝訊號來控制該穿透式光調制器14之開啟與截止。如 圖3所示，為輸入穿透式光調制器14之輸入訊號以及相 對於左右眼輸出光之偏振狀態之波形圖。在本實施例 中，所述穿透式光調制器14按照圖3所示之輸入訊號波 形圖開啟或截止，從而交替為左右眼提供不同偏振方向 的S偏振光及P偏振光。當為該穿透式光調制器輸入該 訊號時，該穿透式光調制器14便可交替輸出S偏振光或 P偏振光以提供觀看者左右眼之不同偏振方向之光。可以 理解的是，該輸入訊號之週期係可以調整的。通過穿透 式光調制器14之開啟與截止可以控制所輸入偏振光之偏 振方向，在本實施例中，輸入穿透式光調制器14的係P 偏振光，下以P偏振光為例，來說明該穿透式光調制器 14的作用原理。當然，可以想到的是，對S偏振光之作 用係與P偏振光相同。 在該穿透式光調制器14開啟時，如圖1所示，該P 偏振光直接穿過該穿透式光調制器14而不會對該P偏振 光之偏振狀態進行調制。但是，在穿透式光調制器14截 止時，如圖2所示，就會對穿過之P偏振光進行調制， 即把輸入之P偏振光調制為S偏振光輸出，從而可以交 替地為觀看者提供左右眼之不同偏振方向之光。 所述投影鏡頭15設置於穿透式光調制器14之出射光 之光路上，用於將出射光所形成之圖像放大，並將放大 10 200914875 之圖像投影到螢幕（圖未示）上。 圖4為本發明提供之第二實施例之立體投影光學系 統200之結構示意圖。該立體投影光學系統200包括沿 光路方向依次設置之一光源組件21、一圖像吸收器22， 一設置於所述圖像吸收器22出射光路上之穿透式光調制 器24以及一投影鏡頭25。 該第二實施例與第一實施例之不同在於所述圖像吸 收器22之組成結構不同，第二實施例之圖像吸收器22 包括一偏振分束器221及一穿透式空間光調制器222。該 穿透式空間光調制器222可以為液晶顯示裝置（Liquid Crystal Dispaly，LCD)。所述穿透式空間光調制器222通 過控制輸入光之偏振狀態來調制入射光並給入射光加入 空間訊息，形成包括該空間訊息之經過調制之出射光。 所述空間訊息可以為所述穿透式空間光調制器222所載 入的控制訊號電壓，該控制訊號電壓直接控制薄膜電晶 體之開關狀態，再利用該薄膜電晶體來控制所述液晶分 - 子之偏轉狀態，而液晶分子具有明顯之光學各向異性， 能夠控制來自入射光之光線，從而實現為入射光載入圖 像訊號之目的。在本實施例中，該所述穿透式空間光調 制器222對入射之S偏振光進行調制，並在所述S偏振 光上疊加空間訊息，以產生一包括空間訊息之出射光， 即包括有空間訊息之P偏振光。該P偏振光穿過該穿透 式空間光調制器222後發射出去。而該P偏振光或S偏 振光在其他光學元件如穿透式光調制器24中之傳輸光路 11 200914875 相同。 上述立體投影光學系統使用時可通過為穿透式光調 制器輸入訊號使得該穿透式光調制器具有開啟及截止兩 個交替之工作狀態，使得觀看者之左、右眼交替獲得不 同偏振狀態之影像，當該輸入訊號之頻率足夠快時，觀 看者之左右眼分別戴上檢偏方向相互垂直之兩片偏振 片，就可以觀察到立體之圖像訊息。 綜上所述，本發明符合發明專利要件，爰依法提出 專利申請。惟，以上所述者僅為本發明之較佳實施方式， 本發明之範圍並不以上述實施方式為限，舉凡熟悉本案 技藝之人士援依本發明之精神所作之等效修飾或變化， 皆應涵蓋於以下申請專利範圍内。 【圖式簡單說明】 圖1係本發明第一實施例之立體投影光學系統在所 述穿透式光調制器開啟時之結構示意圖。 圖2係本發明第一實施例之立體投影光學系統在所 - 述穿透式光調制器截止時之結構示意圖。 圖3係圖1的所述穿透式光調制器之輸入訊號以及 相對於左右眼輸出之光之偏振狀態之波形圖。 圖4係本發明提供之第二實施例之立體投影光學系 統之結構示意圖。 12 200914875 【主要元件符號說明】 立體投影光學系統 100 、 200 光源組件 11、21 照明光源 111 色輪 112 積分器 113 圖像吸收器 12、22 偏振分束器 121 、 221 穿透式光調制器 14、24 投影鏡頭 15、25 反射式空間光調制器 122 ' 222 13200914875 IX. Description of the Invention: [Technical Field] The present invention relates to a projection optical system, and more particularly to a stereoscopic projection optical system having high contrast. [Prior Art] In recent years, image projectors, especially digital projectors, have become popular as tools for displaying a variety of messages to viewers. Typically, these projectors are used to project a computer-generated image onto a screen. For the viewer, the image is projected; the image projected by the instrument usually looks like a flat 2D image, and no image depth of field information can be displayed except the image itself. This display is not suitable for displaying multiple messages. However, in some cases, the viewer desires to have a projector that can display the depth of field or structural features of the image to a greater extent than the two-dimensional display. One way to enable an image of a two-dimensional display to give an image depth of field is to display the image stereoscopically. Stereoscopic images, often referred to as "three-dimensional," or 3D images, have depth dimensions to the viewer's view. These images include separate, superimposed left and right eye images that are set to mimic people When viewed from the left and right eyes, the depth of field image is displayed due to the slight difference in the surface of the three-dimensional object caused by the human eye interval. The left and right eye images are displayed such that the right eye of the viewer cannot see the left eye image. The left eye does not see the right eye image. This display method is generally by means of the viewer's optical filter." Usually the way to read the ® image is displayed. Two separate image projection systems are used to project the left eye image. Like and right eye images. While this system ^ 200914875 was successfully used to form stereo images, the cost and weight of the system was much higher than that of a single projector. Moreover, the two projectors require optical alignment to be relatively difficult and time consuming. Also, due to the weight and volume of the two systems, it is particularly difficult to move the system between two positions, and there is a potential for image alignment. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide a stereoscopic projection optical system capable of improving contrast. A stereoscopic projection light m is arranged according to an optical path: an image absorption n is used for receiving human light, modulating the human light and carrying a spatial information, and emitting a modulated and manned spatial information with a vertical polarization direction a first-polarized light and a second polarized light; a transmissive shafting device disposed on the outgoing light path of the image absorber; the transmissive light modulator has an active working state The transmissive light modulator is configured to open the first polarized light through the transmissive light modulator, and when the off-state is in an off state, the transmissive light modulation is modulated into a second polarized light and emitted. The input signal of the device makes the transmissive light adjust the working state of the tooth-transformed first, so that the image with the same polarization state of turning on and off is observed, and when the round enters the frequency=frequency=the left eye of the viewer Wear the direction of the detection separately; enough = the film, you can observe the stereo image information. Two-plate polarization 200914875 [Embodiment]: The surface will be combined with _, and the embodiment will be described in detail below and described in detail with reference to the drawings. Please refer to FIG. 1 and FIG. 2 for a schematic structural view of a vertical optical system 100 according to a first embodiment of the present invention. The stereoscopic projection optical pregnancy includes a light source assembly n arranged in the direction of the optical path, a picture: 12, a translucent optical modulator 14 disposed on the exiting optical path of the image absorber 12, and a projection lens 15 . 111 The light source assembly U includes an illumination source, a color wheel 112, and an integrator 113. The illumination light source 1U emits white light of red light (8), green light (G) and blue light (8) required for displaying a non-% image. The light source 11 may be a self-generating lamp, a metal-focal lamp, a gas lamp or an LED # . In this embodiment, the light source ^ is a tooth lamp. The color wheel 112 includes red, green, and blue color zones that are rotatably movable under the movable motion of a motor (not shown) to match the projection light path with various colors. The integrator 113 is used to homogenize and effectively use the light emitted by the light source 11. The image absorber 12 & includes a polarization beam splitter 121 and a reflective spatial light modulator 122 disposed in accordance with the optical path. The polarization beam splitter (PBS) 121 is configured to change the unpolarized light from the light source element 11 into the first polarized light and the second polarized light. In the embodiment, the first polarized light is s-polarized light. The second polarized light is p-biased light. The S-polarized light is reflected by the polarization beam splitter 121, and the p-polarized light is transmitted through the polarization beam splitter. The polarization beam splitter 121 may be a wire grid polarizer (WGP polarizer), and the 200914875 may be a polarization beam splitter. In the embodiment, the polarization beam splitter ΐ2 is a polarization beam splitter. The polarization beam splitter 121 can be divided into reflected s-polarized light and transmitted according to the difference between the effects of the s-polarized light and the p-polarized light. The polarized light is reflected in two forms of p-polarized light transmitted through S-polarized light. In the present embodiment, the polarization beam splitter 23 reflects s-polarized light and allows P-polarized light to pass therethrough. The reflective spatial light modulator 122 can be a Liquid Crystal on Silicon (LCoS) display panel. The bismuth-based liquid crystal display panel process structure combines liquid crystal technology and semiconductor integrated circuit technology. The LCoS panel uses a semiconductor process to fabricate the driver panel, and then grinds it on the transistor using a grinding technique, and plated with aluminum or silver as a mirror to form a CMOS substrate, and then attaches the CM〇S substrate to the glass substrate containing the transparent electrode. The liquid crystal molecules are poured into the whole and packaged and tested to form an lc〇s panel. The L C 〇 S panel modulates the incident light by controlling the polarization state of the light and adds a spatial message to the incident light to form an outgoing light including the incident light and the spatial information modulated. The spatial information may be a control signal voltage loaded by the Lc〇s, the control signal voltage directly controls a switching state of the thin film transistor, and the thin film transistor is used to control a deflection state of the liquid crystal molecule, and the liquid crystal molecule Significant optical divergence:: Ability to control light from incident light for the purpose of loading image signals into incident light. In this embodiment, the reflective spatial light modulation crying 122 modulates the S-polarized light and loads the spatial information, and modulates: P-polarized light loaded with a space § aperture, the p-polarized light, The polarization beam splitter 121 is emitted and emitted. ° 200914875 The transmissive light modulator 14 can be a liquid crystal display device (LCD). The turn-on and turn-off of the transmissive light modulator 14 is controlled by inputting a pulse signal to the transmissive light modulator 14. As shown in Fig. 3, it is a waveform diagram of the input signal input to the transmissive optical modulator 14 and the polarization state of the output light with respect to the left and right eyes. In the present embodiment, the transmissive light modulator 14 is turned on or off according to the input signal waveform pattern shown in Fig. 3, thereby alternately providing S-polarized light and P-polarized light of different polarization directions for the left and right eyes. When the signal is input to the transmissive light modulator, the transmissive light modulator 14 alternately outputs S-polarized or P-polarized light to provide light of different polarization directions of the left and right eyes of the viewer. It can be understood that the period of the input signal can be adjusted. The polarization direction of the input polarized light can be controlled by the turn-on and turn-off of the transmissive light modulator 14. In the present embodiment, the P-polarized light of the transmissive light modulator 14 is input, and the P-polarized light is taken as an example. The principle of operation of the transmissive light modulator 14 will be described. Of course, it is conceivable that the effect on S-polarized light is the same as that of P-polarized light. When the transmissive light modulator 14 is turned on, as shown in Fig. 1, the P-polarized light passes directly through the transmissive light modulator 14 without modulating the polarization state of the P-polarized light. However, when the transmissive optical modulator 14 is turned off, as shown in FIG. 2, the P-polarized light that passes through is modulated, that is, the input P-polarized light is modulated into an S-polarized light output, so that it can be alternately The viewer provides light of different polarization directions for the left and right eyes. The projection lens 15 is disposed on the optical path of the outgoing light of the transmissive light modulator 14 for amplifying the image formed by the emitted light, and projecting the image of the enlarged 10 200914875 onto the screen (not shown). . 4 is a schematic structural view of a stereoscopic projection optical system 200 according to a second embodiment of the present invention. The stereoscopic projection optical system 200 includes a light source assembly 21, an image absorber 22, an image transmissive device 24 disposed on the exiting path of the image absorber 22, and a projection lens. 25. The second embodiment differs from the first embodiment in that the image absorber 22 is different in composition. The image absorber 22 of the second embodiment includes a polarization beam splitter 221 and a transmissive spatial light modulation. 222. The transmissive spatial light modulator 222 can be a liquid crystal display (LCD). The transmissive spatial light modulator 222 modulates the incident light by controlling the polarization state of the input light and adds spatial information to the incident light to form modulated modulated light including the spatial information. The spatial information may be a control signal voltage loaded by the transmissive spatial light modulator 222, the control signal voltage directly controls a switching state of the thin film transistor, and the thin film transistor is used to control the liquid crystal sub- The deflection state of the sub-liquid, while the liquid crystal molecules have obvious optical anisotropy, can control the light from the incident light, thereby achieving the purpose of loading the image signal into the incident light. In this embodiment, the transmissive spatial light modulator 222 modulates incident S-polarized light and superimposes spatial information on the S-polarized light to generate an outgoing light including a spatial message, that is, includes P-polarized light with spatial information. The P-polarized light is transmitted through the transmissive spatial light modulator 222 and emitted. The P-polarized or S-polarized light is the same as the transmission path 11 200914875 in other optical components such as the transmissive optical modulator 24. The stereoscopic projection optical system can be used to input signals to the transmissive optical modulator such that the transmissive optical modulator has two alternating working states of opening and closing, so that the left and right eyes of the viewer alternately obtain different polarization states. In the image, when the frequency of the input signal is fast enough, the left and right eyes of the viewer respectively wear two polarizing plates whose detection directions are perpendicular to each other, and the stereoscopic image information can be observed. In summary, the present invention complies with the requirements of the invention patent, and proposes a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a stereoscopic projection optical system according to a first embodiment of the present invention when the transmissive optical modulator is turned on. Fig. 2 is a schematic view showing the structure of the stereoscopic projection optical system of the first embodiment of the present invention when the transmissive optical modulator is turned off. Fig. 3 is a waveform diagram showing the input signals of the transmissive optical modulator of Fig. 1 and the polarization states of the light outputted with respect to the left and right eyes. Fig. 4 is a schematic view showing the structure of a stereoscopic projection optical system according to a second embodiment of the present invention. 12 200914875 [Description of main component symbols] Stereoscopic projection optical system 100, 200 Light source assembly 11, 21 Illumination light source 111 Color wheel 112 Integrator 113 Image absorber 12, 22 Polarization beam splitter 121, 221 Transmissive light modulator 14 , 24 projection lens 15, 25 reflective spatial light modulator 122 ' 222 13