1227368 五、發明說明α) 【發明所屬之技術領域】 本發明係有關投影光學系統，尤其係指一種可遮蔽投射 於螢幕上雜光之投影光學系統。 【先前技術】 請參閱第1圖所示，係習知斜射之數位光源處理（D L Ρ， D i g i t a 1 L i gh t P r〇c e s s i ng)投影顯示系統採用之數位微型 鏡裝置（Digital micro-mirror device， DMD) 1 1 A ，其進行封裝時，會設置一光學玻璃1 1 1 A於D M D晶 片1 1 2A上，並利用氣相沉積（Vapor deposition)方法 直接於光學玻璃1 1 1A上形成一遮蔽薄膜1 1 3A，再於 遮蔽薄膜1 1 3 A中心以化學蝕刻形成一孔徑，後將光學玻 璃111A之遮蔽薄膜113A貼近DMD晶片112A入 射面設置，以藉由遮蔽薄膜1 1 3A遮蔽DMD 1 1A有效 區域外金屬導線等產生反射之雜光進入投影鏡頭（圖未示 )，而具有高成像品質；但由於光學玻璃1 1 1 A需接近D MD晶片1 1 2A入射面設置，因此當光學玻璃1 1 1A上 具有微小雜質時，易隨影像投射於螢幕（圖未示）上而影響 晝質，故一般需採用高潔淨度之光學玻璃以改善雜質之影 響，但此方式將會使D M D成本提高；此外，此項較不重要 遮蔽封裝製程之成敗，直接影響昂貴前D M D製程之良率， 而加重製造成本。 因此，為了降低DMD成本及提昇良率，目前之DMD 11Β (如第2圖所示）於封裝時不利用光學玻璃來遮蔽D M D晶片外之區域，而直接將電子電路1 1 4 Β暴露出來；1227368 V. Description of the invention α) [Technical field to which the invention belongs] The present invention relates to a projection optical system, and particularly to a projection optical system that can block stray light projected on a screen. [Prior art] Please refer to FIG. 1, which is a digital micro-mirror device (Digital micro-) used in the conventional oblique digital light source processing (DL P, Digita 1 L i gh t P rcess). Mirror device (DMD) 1 1 A. When packaging, an optical glass 1 1 1 A is set on the DMD wafer 1 1 2A, and it is formed directly on the optical glass 1 1 1A by a vapor deposition method. A masking film 1 1 3A is formed by chemical etching at the center of the masking film 1 1 3 A to form an aperture, and then a masking film 113A of the optical glass 111A is placed close to the incident surface of the DMD wafer 112A to shield the DMD by the masking film 1 1 3A. 1 1A Stray light generated by metal wires outside the effective area enters the projection lens (not shown) and has high imaging quality; however, since the optical glass 1 1 1 A needs to be set close to the D MD chip 1 1 2A incident surface, so when When optical glass 1 1 1A has small impurities, it is easy to affect the daytime quality as the image is projected on the screen (not shown). Therefore, it is generally necessary to use high-cleanness optical glass to improve the effect of impurities, but this method will Increase D M D cost; In addition, this less important masks the success or failure of the packaging process, which directly affects the yield of the expensive former D M D process and increases manufacturing costs. Therefore, in order to reduce the DMD cost and improve the yield, the current DMD 11B (as shown in Figure 2) does not use optical glass to shield the area outside the D M D chip during packaging, and directly exposes the electronic circuit 1 1 4 B;
1227368 五、發明說明（2) 當其應用於背投影系統時係利用顯示螢幕周圍設置螢幕框架 作為遮罩，而遮住隨暴露的電子電路投射於螢幕之雜散敎 像，使其不影響影像品質；然於前投影系統中因不具備螢幕 框架，因此，利用框架遮蔽方式顯然無法應用於前投影系 統。 而習知一應用於斜射之前投影系統之方式，請參閱第2 圖所示，係利用於照明單元1 2入射於D M D 1 1 B之光路 徑上設置一遮蔽元件1 3 ，藉由遮蔽元件1 3以遮蔽雜散光 後再入射於D M D 1 1 Β ，但於斜射之投影系統中，照明單 元1 2提供之矩形光束（如第3 Α圖所示）將斜向入射於D M D 1 1 ， 致使照明光斑於D M D 1 1 Β上產生形變光束 (如第3 Β圖所示），且為了降低光斑變形造成外圍亮度損 失，一般於DMD1 1Β上之光斑將大於DMD晶片1 1 2 Β區域，致使部分光束會投射於D M D 1 1 Β之電子電路1 14Β區域，因此，將遮蔽元件1 3設於DMD1 1Β入射 光路徑上，僅可遮蔽有效光束外之雜散光，卻無法遮敝斜射 形變後或光斑增大造成之雜散光（即投射於電子電路區域並 反射至投影鏡頭1 4之光束）；因此，習知利用遮蔽元件之 方式由於受到斜射系統具有光斑形變之影響，而無法有效達 到遮蔽雜散光。 【發明内容】 本發明之一目的，係提供一種投影光學系統，利用成像 透鏡將光閥影像形成於光閥外之成像面，並設置一遮蔽元件 於成像面上以遮蔽雜散光，而提高成像品質且降低成本。1227368 V. Description of the invention (2) When it is applied to a rear projection system, it uses the screen frame around the display screen as a mask to shield the stray artifacts projected on the screen with the exposed electronic circuits, so that it does not affect the image Quality; however, because the front projection system does not have a screen frame, it is obvious that using the frame masking method cannot be applied to the front projection system. The conventional method is applied to the projection system before the oblique projection. Please refer to FIG. 2, which is used to set a shielding element 1 3 on the light path of the lighting unit 12 incident on the DMD 1 1 B, and the shielding element 1 3 to block stray light before entering the DMD 1 1 Β, but in the oblique projection system, the rectangular beam provided by the lighting unit 12 (as shown in Figure 3A) will be incident on the DMD 1 1 obliquely, resulting in illumination The light spot produces a deformed light beam on DMD 1 1 Β (as shown in Figure 3B), and in order to reduce the deformation of the light spot and cause peripheral brightness loss, the light spot on DMD 1 1B will generally be larger than the DMD chip 1 1 2 Β area, causing part of the light beam It will be projected on the electronic circuit 1 14B area of DMD 1 1 Β. Therefore, setting the shielding element 1 3 on the incident light path of DMD1 1B can only block the stray light outside the effective beam, but cannot obstruct the oblique deformation or increase the light spot. Large stray light (ie, the light beam projected on the electronic circuit area and reflected to the projection lens 14); therefore, the conventional method of using a shielding element is affected by the deformation of the light spot due to the oblique system, which cannot Up to shield stray light. SUMMARY OF THE INVENTION An object of the present invention is to provide a projection optical system, which uses an imaging lens to form a light valve image on an imaging surface outside the light valve, and sets a shielding element on the imaging surface to block stray light, thereby improving imaging. Quality and reduced costs.
1227368 五、發明說明（3) 本發明之一目的，係提供一種投影光學系統，利用將遮 蔽元件設於光閥外之反射路徑上，以有效阻絕斜射造成缸電 子電路反射之雜散光。 為達上述目的，本發明之投影光學系統包括一光源、一 光閥、一成像透鏡、一遮蔽元件及一投影鏡頭，其中該遮蔽 元件具有孔徑及遮蔽區並設於成像透鏡形成之成像面上；當 光源提供之照明光束投射於光閥上，藉由光閥將照明光束轉 化成影像光束，再入射於成像透鏡而將影像成像於遮蔽元件 上，利用遮蔽區將雜散影像遮蔽後，再經投影鏡頭將影像呈 現於螢幕上，由於於成像面上遮蔽雜散影像且遮蔽元件不需 貼近光閥設置，故可提高成像品質且降低成本。 【實施方式】 有關本發明為達到上述目的，所採用之技術手段及其餘 功效，茲舉一較佳實施例，並配合圖式加以說明如下： 請參閱第4圖所示，本發明斜射之投影光學系統2 0包 括一光源2 1 、一光閥2 2、一成像透鏡2 3 、一遮蔽元件 2 4及一投影鏡頭2 5 ;其中該光源2 1提供一照明光束2 1 1 A，照明光束2 1 1 A經色輪2 6及積分柱2 7作濾光 及均勻化處理後，斜向投射於設於照明光束2 1 1 A光路徑 上之光閥2 2 ;光閥2 2係將一光閥晶片2 2 1設於一基座 222上而形成一有電子電路223裸露之光閥22 ，其中 光閥2 2可為D M D或液晶面板，藉由光閥2 2其將照明光 束2 1 1Α轉化成一影像光束2 1 1 Β ，再入射於設於影像 光束2 1 1 Β光路徑（即光閥2 2之反射光路）上之成像透1227368 V. Description of the invention (3) An object of the present invention is to provide a projection optical system that utilizes a shielding element provided on a reflection path outside a light valve to effectively block stray light caused by oblique reflection from a cylinder electronic circuit. To achieve the above object, the projection optical system of the present invention includes a light source, a light valve, an imaging lens, a shielding element, and a projection lens, wherein the shielding element has an aperture and a shielding area and is disposed on an imaging surface formed by the imaging lens. ; When the illumination beam provided by the light source is projected on the light valve, the illumination beam is converted into an image beam by the light valve, and then incident on the imaging lens to image the image on the shielding element, and the stray image is masked by the shielding area, and then The image is presented on the screen through a projection lens. Since the stray image is shielded on the imaging surface and the shielding element does not need to be placed close to the light valve, the imaging quality can be improved and the cost can be reduced. [Embodiment] Regarding the technical means and other effects adopted by the present invention in order to achieve the above-mentioned object, a preferred embodiment is described below with reference to the drawings: Please refer to FIG. 4, the oblique projection of the present invention The optical system 20 includes a light source 2 1, a light valve 2 2, an imaging lens 2 3, a shielding element 2 4 and a projection lens 2 5; wherein the light source 2 1 provides an illumination beam 2 1 1 A, and an illumination beam After 2 1 1 A is filtered and homogenized by the color wheel 26 and the integrating column 27, the light valve 2 2 is projected obliquely on the light path 2 1 1 A; the light valve 2 2 A light valve wafer 2 2 1 is provided on a base 222 to form a light valve 22 with an electronic circuit 223 exposed. The light valve 2 2 can be a DMD or a liquid crystal panel, and the light beam 2 can be illuminated by the light valve 2 2. 1 1Α is converted into an image beam 2 1 1 Β, and then incident on the imaging beam set on the optical path of the image beam 2 1 1 Β (that is, the reflected light path of the light valve 22).
1227368 五、發明說明（4) 鏡2 3 ，而將光閥2 2影像成 使成像面2 3 1離開光閥2 2 於成像面2 3 1上，同時於該 可避免影響光閥2 2 ，另外， 位置，可依光閥大小而定，一 上之形狀與大小與投射於成像 請參閱第5圖所示，遮蔽元件 24 1及一遮蔽區242 ，該 1外圍’並以錄膜、黏貼或塗 (如：黑色金屬層、反射層） 散光束受到遮蔽層之阻絕，而 而投射於孔徑2 4 1之光閥2 1通過，經投影鏡頭2 5而成 達到遮敗雜散光束，使成像品 照明光束投射於光閥2 2上之 31上者相同，遮蔽元件24 效區域（即具有光閥晶片2 2 於設置遮蔽元件2 4及決定遮 由於本發明係藉由成像透 至成像於一光閥2 2外之成像 面2 3 1之遮蔽元件24 ，將 曝露之電子電路2 2 3區域） 頭2 5將遮除雜光後之影像呈 明之投影光學系統可直接於成 像於一預定成像面2 3 1上， ，以便容易設置遮蔽元件& 4 成像面2 3 1上進行遮蔽時， 該成像透鏡2 3之曲率與設置 般使照明光束投射於光閥2 2 面2 3 1上者相同為最佳； 2 4 具有一孔從（Aperture) 遮蔽區2 4 2係幾於孔徑2 4 佈方式設置適當寬度遮蔽層 ，使投射於遮蔽區2 4 2之雜 不將影像呈現於骛幕2 8上， 2有效區域光束可由孔徑2 4 像於一螢幕2 8上，因此，可 貝長：向；而當成像透鏡2 3使 形狀與大小與投射於成像面2 之孔徑2 4 1可依光閥2 2有 1區域）大小而設，以達到便 蔽元件2 4尺寸。 鏡2 3先將光閥2 2影像移動 面2 3 1上，再利用設於成像 光閥2 2有效區域外（例如·· 之影像遮蔽後，再經由投影鏡 現於螢幕2 8上，因此，本發 像透鏡2 3之成像面2 3 1上1227368 V. Description of the invention (4) Mirror 2 3, and the light valve 2 2 is imaged so that the imaging surface 2 3 1 leaves the light valve 2 2 on the imaging surface 2 3 1. At the same time, it can avoid affecting the light valve 2 2. In addition, the position can be determined according to the size of the light valve. The shape and size of the upper part and the projection on the image are shown in FIG. 5. The shielding element 24 1 and a shielding area 242 are recorded on the periphery of the 1 '. Or coating (such as: black metal layer, reflective layer) The scattered light beam is blocked by the shielding layer, and the light valve 2 1 projected through the aperture 2 4 1 passes through the projection lens 25 to reach the stray light beam. The illumination beam of the imaging product is projected on 31 of the light valve 22, the same as that of the shielding element 24 (i.e., the light valve chip 2 2 is used to set the shielding element 24 and the shadow is determined. As the present invention is through imaging through to imaging A light valve 2 2 is a shielding element 24 on the imaging surface 2 3 1 and the exposed electronic circuit 2 2 3 area) The head 2 5 is a projection optical system that will clear the image after stray light can be directly imaged on a predetermined On the imaging surface 2 3 1 so as to easily set the shielding element & 4 imaging surface 2 3 1 When masking, the curvature of the imaging lens 23 is the same as the setting so that the illumination beam is projected on the light valve 2 2 surface 2 3 1 is the best; 2 4 has an aperture from the (Aperture) masking area 2 4 2 series Set an appropriate width masking layer on the aperture 2 4 cloth, so that the shadows projected on the masking area 2 4 2 will not present the image on the screen 28, and the 2 effective area beam can be imaged on the screen 2 8 by the aperture 2 4. , Can be long: toward; and when the imaging lens 23 makes the shape and size and the aperture 2 4 1 projected on the imaging surface 2 can be set according to the size of the light valve 2 2 to achieve the size of the toilet element 2 4 . The mirror 2 3 firstly places the light valve 2 2 on the image moving surface 2 3 1, and then uses it outside the effective area of the imaging light valve 2 2 (for example, the image is masked, and then appears on the screen 2 8 through the projection mirror, so On the imaging surface 2 3 1 of the image lens 23
1227368 五、發明說明（5) 遮蔽雜光，且成像透鏡2 3與遮蔽元件設於光閥2 2之反射 路徑上，致使斜射形變後或光斑增大而投射於電子電路產域 之光束，可由光閥反射後，經成像透鏡2 3將影像移至光閥 外再次成像後，再利用置於成像面之遮蔽元件2 4將雜散光 遮蔽，因此，可有效達到遮蔽效果。 另由於本發明不直接於光閥2 2成像面上遮蔽雜光，而 於藉由成像透鏡2 3將光閥影像形成於光閥外之成像面2 3 1上進行遮蔽雜光，因此遮蔽元件不接觸光閥2 2 ，故不會 影響光闊2 2成像品質且不需採用高潔淨度之光學玻璃，所 以，可降低系統成本。 以上所述，僅用以方便說明本發明之較佳實施例，本發 明之範圍不限於該等較佳實施例，凡依本發明所做的任何變 更，於不脫離本發明之精神下，皆屬本發明申請專利範圍。1227368 V. Description of the invention (5) The stray light is shielded, and the imaging lens 23 and the shielding element are arranged on the reflection path of the light valve 22, so that the beam projected into the electronic circuit production area after the oblique deformation or the increase of the light spot is caused by After the light valve reflects, the image is moved to the outside of the light valve by the imaging lens 23 to form an image again, and then the stray light is blocked by the shielding element 24 placed on the imaging surface, so the shielding effect can be effectively achieved. In addition, since the present invention does not directly shield stray light on the imaging surface of the light valve 22, but forms the light valve image on the imaging surface 2 3 1 outside the light valve by the imaging lens 2 3, thereby shielding the element It does not touch the light valve 2 2, so it will not affect the imaging quality of the light 2 2 and does not need to use high-cleanness optical glass, so the system cost can be reduced. The above description is only for the convenience of describing the preferred embodiments of the present invention, and the scope of the present invention is not limited to these preferred embodiments. Any changes made in accordance with the present invention may be made without departing from the spirit of the present invention. It belongs to the patent application scope of the present invention.
1227368 圖式簡單說明 【圖式簡要說明】 第1圖，係習知D M D結構圖。 第2圖，係習知斜射之前投影系統圖。 第3 Α圖，係習知照明單元之照明光束光斑圖。 第3 B圖，係習知D M D上之光束光斑圖。 第4圖，係本發明投影光學系統示意圖。 第5圖，係本發明遮蔽元件之立體圖。 【圖號簡要說明】 投影光學系統 20 光源 照明光束 影像光束 光閥 光閥晶片 基座 電子電路 成像透鏡 成像面 遮蔽元件 孔徑 遮蔽區 投影鏡頭 色輪 積分柱 2 1 1 A 2 1 1 B 2 2 2 2 1 2 2 2 2 2 3 2 3 2 3 1 2 4 2 4 1 2 4 2 2 71227368 Brief description of the diagram [Brief description of the diagram] Figure 1, is a structure diagram of the conventional D M D. Figure 2 is a diagram of the projection system before the conventional oblique projection. FIG. 3A is a light beam spot pattern of a conventional lighting unit. Figure 3B is the beam spot pattern on the conventional D M D. FIG. 4 is a schematic diagram of a projection optical system of the present invention. Fig. 5 is a perspective view of a shielding element according to the present invention. [Brief description of the drawing number] Projection optical system 20 light source illumination beam image beam light valve light valve wafer base electronic circuit imaging lens imaging surface shielding element aperture shielding area projection lens color wheel integrating column 2 1 1 A 2 1 1 B 2 2 2 2 1 2 2 2 2 2 3 2 3 2 3 1 2 4 2 4 1 2 4 2 2 7
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