M281179 16510twf.doc/r 八、新型說明： 【新型所屬之技術領域】 本創作是有關於一種變焦鏡頭，且特別是有關於一種 具有高解像力的變焦鏡頭。 【先前技術】 一般投影裝置係藉由光學引擎產生影像，再藉由變焦 鏡頭將影像投影於螢幕上，所以投影裝置所投影出的晝面 品質是與光學引擎及變焦鏡頭的光學品質息息相關。 圖1A與圖1B分別繪示為習知一種變焦鏡頭在不同變 焦倍率下的結構示意圖。習知的變焦鏡頭1〇〇主要係由三 透鏡群110、120、130所組成。而此三透鏡群11〇、12〇、 130分別由4片透鏡112、2片透鏡122及4片透鏡132所 組成。當變焦鏡頭100之倍率由望遠端⑽e-end)(如圖1A 所不）變成廣角端(wide_end)(如圖1B所示），或者由廣角端 變成望遠端時，此三透鏡群110、120、130必須同時移動， 以達到倍率放大或縮小的效果。 然而習知變焦鏡頭1〇〇的解像力有限，因此僅適於搭 配I·55吋、解析度為800x600(SVGA)的光閥來使用。但在 :4的才又影裳置中，〇·55吋、解析度為1〇24x768(XGA)的 漸成為主流。在這種情況下，如何提高變焦鏡頭 力’已為目前亟欲解決的問題。 【新型内容】 苴且有ί"於此，本創作的目的就是在提供一種變焦鏡頭， ^具有兩解像力，因此可與不畴析度但尺寸相同的光間 杧配使用，進而降低投影機整體的生產成本。 5 M281179 16510twf.doc/r 本創作k出一種變焦鏡頭’其適於將顯 之影像投影於螢幕上。此變隹杯、 斤產生 透鏡群，其中第—靜鏡群與第二 叙的表面分別具有—曲率中心、，而每—曲 二透 所對應之表面的同—側。第 =;其 與顯示元件之間，且笛_^群禮置於弟—透鏡群 一、惫比 弟一透鏡群之光學焦度值為負值，裳 一透叙群之光學焦度值為正值。 、弟M281179 16510twf.doc / r 8. Explanation of the new model: [Technical field to which the new model belongs] This creation is about a zoom lens, and in particular, a zoom lens with high resolution. [Previous technology] Generally, the projection device generates an image by using an optical engine and then projects the image on the screen by using a zoom lens. Therefore, the quality of the daylight projected by the projection device is closely related to the optical quality of the optical engine and the zoom lens. FIG. 1A and FIG. 1B are schematic structural diagrams of a conventional zoom lens under different zoom magnifications, respectively. The conventional zoom lens 100 is mainly composed of three lens groups 110, 120, and 130. The three lens groups 110, 120, and 130 are respectively composed of four lenses 112, two lenses 122, and four lenses 132. When the magnification of the zoom lens 100 is changed from the telephoto end ⑽e-end (as shown in Fig. 1A) to the wide-angle end (as shown in Fig. 1B), or from the wide-angle end to the telephoto end, the three lens groups 110, 120 , 130 must move at the same time to achieve the effect of magnification or reduction. However, the resolution of the conventional zoom lens 100 is limited, so it is only suitable for use with I. 55-inch light valves with a resolution of 800x600 (SVGA). However, among the talents of the 4th generation, the 55.55 inches and the resolution of 1024x768 (XGA) gradually became the mainstream. In this case, how to increase the power of the zoom lens has become an urgent problem to be solved. [New content] Here, the purpose of this creation is to provide a zoom lens, which has two resolutions, so it can be used with non-resolution, but the same size light, thereby reducing the overall projector Production costs. 5 M281179 16510twf.doc / r This creation creates a zoom lens ’which is suitable for projecting a displayed image on the screen. This change produces a lens group, in which the surface of the first-static lens group and the surface of the second lens respectively have a center of curvature, and each surface of the second lens corresponds to the same side of the surface. No. =; between it and the display element, and the diopter group is placed in the lens-lens group, the lens group is negative, and the optical power value of the lens group is negative; Positive values. ,younger brother
铲ί述f弟一透鏡群例如是包括依序排列之第-透 乂兄透鏡、第三透鏡以及第四透鏡，其中第四透鏡是 位於鄰近顯示元件之一側，而第一、第：盥j叙： 鏡的光學域健料正值、貞值、貞值與域:四透 μ上迭之第一透鏡群例如是包括依序排列之複合透鏡、 =五透鏡、第六透鏡、第七透鏡以及H鏡，其中第八 ，鏡是位於鄰近顯示元件之―側，而複合透鏡、第五透鏡、 弟六透鏡、第七透鏡與“透鏡的光學焦度值依序為正 值正值、負值、正值與正值。此複合透鏡例如是由二透 鏡所構成。 上述之第六透鏡具有一阿貝數Ab6，且第七透鏡具有 一阿貝數Ab?，而阿貝數战與Ab7的關係例如是Ab7/ Ab6 。 上述之第一透鏡群例如是具有負光學屈光度，且第 透|兄群與弟一透鏡群適於沿一轴向朝相互遠離或相互接 近之方向移動。其中當第一透鏡群與第二透鏡群沿此轴向 朝相互遠離之方向移動時至廣角端時，此變焦鏡頭具有正 6 M281179 165】0twf.doc/r 光學屈光度p。而且，負光學糾度0丨與正光學屈光声 0 2之關係為|必1/必2 | g〇.〇35。 又 依照本創作的較佳實補所述，當 ，群沿此軸向朝相互遠離之方向移動至廣 =通過苐-透鏡之主域高料CHw，而#第_透^表 ^弟二透鏡群沿_向朝相互接近之 =邊緣視場通過第一透鏡之主光線高度為cHt望二 CHw/CHtl^j.238, | CHw-CHt 1^3.538 〇 頭的疋=====提下，可提高變焦鏡 隹㈣％ 崎度萄的糾可以制本創作變 兄頭L進而降低投影裝置整體的生產成本。 易懂為和其他目的、特徵和優點能更明顯 明如下。牛1^貫施例’並配合所附圖式，作詳細說 【實施方式】 將顯示科5G 7適於 其中第二透鏡鏡群別與—第二透鏡群⑽， 5〇之間，且第—透於君:，己置於3 一透鏡群210與顯示元件 值分別為負值與正^ 1〇與第二透鏡群220的光學焦度 表面=由多個透鏡所構成，且這些透鏡的 之表面㈣1。:而每—曲率巾心、均位於其所對應 側。換舌之，假設曲率中心位於曲面之右側 M281179 16510twf.doc/r 時 疋義曲面的曲率半徑為正值，則本實施例中這些透鏡 表面的曲率半徑均為正值。對此，後文將進一步做說明。 在本實施例中，第一透鏡群210例如是由依序排列之 第一透鏡212、第二透鏡214、第三透鏡210以及第四透鏡 218所組成，其中第四透鏡218是鄰近第二透鏡群22〇，而 第一透鏡212、第二透鏡214、第三透鏡216與第四透鏡 218之光學焦度值例如是依序為正值、負值、負值與正值。 苐一透知群220例如是由依序排列之複合透鏡222、 第五透鏡224、第六透鏡226、第七透鏡228與第八透鏡 229所組成，其中第八透鏡229是鄰近於顯示元件5〇之一 側。複合透鏡222適於消除大角度光線入射時所產生的橫 向色差、，且複合透鏡222例如是由二透鏡221、223所組 在此，複合透鏡222、第五透鏡224、第六透鏡〕％、 ，鏡2=與第人透鏡229之光學焦度值例如是依序為正 值、正值、負值、正值與正值。 顯示元件50前方例如配置有一保護鏡片6〇。 上述之變焦鏡頭200中，第一透鏡群2 負光學屈光度…且第—透鏡群⑽與第二透]鏡=有 例如適於沿遠離辅近彼此的方 透 變焦鏡頭200之倍率。進—步來說，者 以改艾此 大時，變焦鏡頭200會由望遠端(如圖= =最 (如圖2Β所示）。當第—透鏡群21Q與第 學屈光咖。在-實施例中，負光學屈光 8 M281179 16510twf.doc/r 學屈光度0 2之間的關係例如是符合I 0丨/I $〇 〇35 的條件’藉以改善在相同變倍比(z〇〇mrati〇)的條件下，會 造成第一透鏡群210的累積像差過大，以致於第二透鏡群 220無法完全消除累積像差，而提高變焦鏡頭2〇〇的光學 口口貝。另一方面，當倍率由最大變至最小時，變焦鏡頭200 會由廣角端變成望遠端。也就是說，第一透鏡群21〇與第 二透鏡群220是朝接近彼此的方向移動。 ^备、交焦鏡頭200之倍率變為廣角端時，邊緣視場通過 第透叙212主光線高度例如是CHw，而當變焦鏡頭2〇〇 =倍率變為望遠端時，邊緣視場通過第一透鏡212主光線 回度例如是CHt，且高度CHw與高度⑽之間例如是符 合丨CHw/CHt | g238與丨CHw_CHt丨幻.538的條件。 、、在本實施例之變焦鏡頭2〇〇中，更可藉由第一透鏡群 210 & X軸朝遠離或接近顯示元件5〇的方向移動，以調整 位置時的成像位置，使變焦鏡頭投影出清 /像。換言之，第一透鏡群21〇除了具有變焦的功能外， =成:補？功能，所以可以避免像差與成像 些微地移動第一透;君鏡1會由廣角端變成望遠端時， 、 抄初乐透知群210，即可補償回在此倍率、變拖 =中所造成像平面偏移的現象。而且，在相同的投影距 :下’廣角端至望遠端的重新聚焦 : 便於進行重新聚焦的動作。 相古 值传—提的是’在本實施例之變焦鏡頭中，敏_ 、兄君f之第六透鏡之阿貝數(Abbe number)為Ab6，而第= 9 M281179 16510twf.doc/r Μ7 ’且Ab6與Ab7之間的關係例如是符 口 Ab7/ Ab6 = 2的條件’精以改善於第二透鏡群中造成色 差無法自我消除的問題，而達到滿足高解像力及低像散 (Astigmatism)的需求。The lens group includes, for example, a first-transparent lens, a third lens, and a fourth lens arranged in order. The fourth lens is located on one side of the adjacent display element, and the first and second: J: Positive value, true value, true value, and true value of the optical domain of the mirror: The first lens group with four transparent μ superimposed is, for example, a compound lens arranged in order, five lenses, sixth lens, seventh The lens and the H lens, the eighth of which is located near the display element, and the optical power of the compound lens, the fifth lens, the sixth lens, the seventh lens, and the "lens are sequentially positive, Negative, positive, and positive values. This compound lens is composed of, for example, two lenses. The sixth lens described above has an Abbe number Ab6, and the seventh lens has an Abbe number Ab? The relationship of Ab7 is, for example, Ab7 / Ab6. The above-mentioned first lens group has, for example, negative optical power, and the first lens group and the second lens group are adapted to move in a direction away from or close to each other along an axial direction. When the first lens group and the second lens group move away from each other along this axis When moving to the wide-angle end, this zoom lens has a positive 6 M281179 165] 0twf.doc / r optical diopter p. Moreover, the relationship between the negative optical correction 0 丨 and the positive optical refractive sound 0 2 is | must 1 / must 2 g〇.〇35. Also according to the better practical supplement of this creation, when, the group moves along this axis toward each other in the direction of distant from each other to wide = through the main field of the 苐 -lens high material CHw, and # 第 _ ^^^^ The two lens groups are close to each other in the _ direction = the height of the main ray of the edge field of view passing through the first lens is cHt Wang II CHw / CHtl ^ j.238, | CHw-CHt 1 ^ 3.538 ===== As mentioned, the zoom lens can be improved by 崎%. The correction can be used to create the original L and reduce the overall production cost of the projection device. It is easy to understand and can be more obvious with other purposes, features and advantages. The description is as follows. Niu 1 ^ exemplifies the embodiment and cooperates with the attached drawings to explain in detail. [Embodiment] The display section 5G 7 is suitable for the second lens group and the second lens group, between 50 , And the first through the Jun :, have been placed in the three lens group 210 and the display element values are negative and positive ^ 10 and the second lens group 220 optical Degree surface = composed of multiple lenses, and the surfaces of these lenses ㈣1: and each-the center of curvature, is located on its corresponding side. In other words, suppose the center of curvature is located on the right side of the curved surface. M281179 16510twf.doc / r When the radius of curvature of the sense curved surface is positive, the curvature radii of the lens surfaces in this embodiment are all positive values. This will be further described later. In this embodiment, the first lens group 210 is, for example, It consists of a first lens 212, a second lens 214, a third lens 210, and a fourth lens 218 which are arranged in order. The fourth lens 218 is adjacent to the second lens group 22o, and the first lens 212 and the second lens 214 The optical power values of the third lens 216 and the fourth lens 218 are, for example, positive values, negative values, negative values, and positive values in this order. The first transparent group 220 is composed of, for example, a compound lens 222, a fifth lens 224, a sixth lens 226, a seventh lens 228, and an eighth lens 229, which are arranged in order. The eighth lens 229 is adjacent to the display element 50. One side. The compound lens 222 is suitable for eliminating the lateral chromatic aberration generated when a large angle of light is incident. For example, the compound lens 222 is composed of two lenses 221 and 223. The compound lens 222, the fifth lens 224, and the sixth lens]%, The optical power values of the lens 2 = and the first lens 229 are, for example, positive values, positive values, negative values, positive values, and positive values in this order. A protective lens 60 is arranged in front of the display element 50, for example. In the above-mentioned zoom lens 200, the first lens group 2 has a negative optical dioptric power ... and the first lens group ⑽ and the second lens] have = the magnification of the zoom lens 200 suitable for, for example, passing through the square lenses far away from each other. Further, when the change is made, the zoom lens 200 will be changed from the telephoto end (as shown in the picture = = the most (as shown in Fig. 2B). When the first-lens group 21Q and the first school refractive coffee. In- In the embodiment, the relationship between the negative optical power 8 M281179 16510twf.doc / r and the optical power 0 2 is, for example, to meet the condition of I 0 丨 / I $ 〇〇35 to improve the same zoom ratio (z〇〇mrati 〇), the cumulative aberration of the first lens group 210 is too large, so that the second lens group 220 cannot completely eliminate the cumulative aberration, and increase the optical mouthpiece of the zoom lens 200. On the other hand, When the magnification is changed from the maximum to the minimum, the zoom lens 200 will change from the wide-angle end to the telephoto end. That is, the first lens group 21 and the second lens group 220 move toward each other. ^ Preparation, cross-focus lens When the magnification of 200 becomes the wide-angle end, the height of the edge field of view through the first 212 main light is CHw, and when the zoom lens 200 = the magnification becomes the telephoto end, the edge field of view returns through the main light of the first lens 212. The degree is, for example, CHt, and the height between CHw and height 符合 corresponds to, for example, CHw / CHt | g 238 and CHw_CHt 丨 magic. 538. In the zoom lens 200 of this embodiment, the first lens group 210 & X axis can be moved away from or close to the display element 50, In order to adjust the imaging position, the zoom lens projects a clear image. In other words, in addition to the zoom function, the first lens group 21 has a function of: compensation ?, so it can avoid aberration and imaging to move slightly. Once through; when the mirror 1 will change from the wide-angle end to the telephoto end, copy the early lotto knowledge group 210 to compensate for the phenomenon of image plane shift caused by this magnification and variable drag =. Also, in the same Projection distance: down 'Refocusing from wide-angle end to telephoto end: It is convenient to perform refocusing. It ’s ancient value-mentioning that' in the zoom lens of this embodiment, the sixth lens of Min_, Xiongjun f The Abbe number is Ab6, and the number = 9 M281179 16510twf.doc / r M7 'and the relationship between Ab6 and Ab7 is, for example, the condition of the symbol Ab7 / Ab6 = 2' to improve in the second lens group Causes the problem that chromatic aberration cannot be eliminated by itself, and achieves high resolution And low astigmatism (Astigmatism) requirements.
以下内容將舉出變焦鏡頭200之一較佳實施例，此變 焦鏡頭200之光學屈光度與阿貝數均符合丨丨^ 〇·〇35及AbV Ab6^2的條件。然而，下述之表一及表二中 所列的數據資料並非用以限定本創作，任何熟習此項技術 之人士在參照本創作之後，當可對其參數或設定作適當的 更動，惟其仍應屬於本創作之範疇内。 有效焦距=22·3 lmm〜26·73πιπι 焦距直徑比=2·49〜2·74 表面數 曲率半徑(mm) 厚度(mm) 折射率 色散值 S1 59.17 7 1.6 60.6 S2 428.48 1.72 S3 56.78 2 1.77 49.6 S4 18.56 6.23 S5 1946.31 2.5 1.77 49.6 S6 24.53 9.19 Γ^： S7 33.0 5.5 1.85 23.8 S8 56.51 A \ S9 80.01 7.5 1.52 - \ 58.9 S10 -25.19 1.5 1.73 28.5The following will give a preferred embodiment of the zoom lens 200. The optical power and Abbe number of this zoom lens 200 are in accordance with the conditions of 丨 丨 ^ 35 and AbV Ab6 ^ 2. However, the data and materials listed in Tables 1 and 2 below are not intended to limit this creation. Anyone familiar with this technology can refer to this creation to make appropriate changes to its parameters or settings, but they still have It belongs to the scope of this creation. Effective focal length = 22 · 3 lmm ~ 26 · 73πιπι Focal length diameter ratio = 2 · 49 ~ 2 · 74 Surface number curvature radius (mm) Thickness (mm) Refractive index dispersion value S1 59.17 7 1.6 60.6 S2 428.48 1.72 S3 56.78 2 1.77 49.6 S4 18.56 6.23 S5 1946.31 2.5 1.77 49.6 S6 24.53 9.19 Γ ^: S7 33.0 5.5 1.85 23.8 S8 56.51 A \ S9 80.01 7.5 1.52-\ 58.9 S10 -25.19 1.5 1.73 28.5
M281179 16510twf.doc/r S11 -46.55 7 S12 25.5 3.13 1.65 33.8 S13 91.18 7.44 S14 無限大 1.09 S15 -45.95 7 1.81 25.4 S16 33.70 0.87 S17 296.82 2.33 1.69 53.2 S18 -33.34 0.1 S19 -105.28 0 S20 40.65 2.47 1.73 51.5 S21 -110.81 B S22 無限大 3 S23 無限大 0.483 1.49 70.4 S24 無限大 表一 焦距(mm) A (mm) B (mm) 廣角端 22.31 9.339 2.056 望遠端 26.73 35.594 40.580 表二 在表一中，表面SI、S2為第一透鏡212之二表面、 表面S3、S4為第二透鏡214之二表面、表面S5、S6為第 三透鏡216之二表面、表面S7、S8為第四透鏡218之二 11 M281179 16510twf.doc/r 表面、表面S9為透鏡221之表面、表面S10為透鏡221 與透鏡223相連之表面、表面S11為透鏡223鄰近顯示元 件50之表面、表面S12、S13為第五透鏡224之二表面。 特別的是，本實施例是在第五透鏡224與第六透鏡226之 間配置光攔90，用以限制通光量，而表面SM即為光搁 • 90之表面°S15、S16為第六透鏡226之二表面、表面Sl7、 S18為第七透|見228之二表面。此外，本實施例亦在第七 φ 透鏡228與第八透鏡229之間配置光欄95,且表面S19為 光攔95之表面、表面S2〇、S21為第八透鏡229之二表面、 表面S22、S23保護鏡片60之二表面，而表面S24為顯示 兀件50之一表面。此外，有關於各表面之曲率半徑、厚度、 折射率與色散值，請參照表一，在此將不再重述。 、特別的是，表面S8與表面S21在廣角端、中間位置 或是，遠端時均可分別具有不同的厚度值，而表二即是列 出一實施例中表面S8與表面S21在廣角端與望遠端之 度值。 藝目3A與目3B分別纟t示為變焦鏡頭在望遠端及廣角端 所投影出之影像的辨識率與線對數的關係圖。以一般解析 度為1024x768的影像為例，其在丨毫米之距離内可顯示的 線對數(line pair)約為46，且當線對數為牝時，其辨識率 需大於0·5方屬於規範之規格内，或是被一般的使用者所 接受:請同時參照圖3A與圖3B，在本創作一較佳實 中，變焦鏡頭200無論是在望遠端或是在廣角端，其所投 衫出的影像之辨谶率，在線對數為46時仍在〇·5以上，由 12 M281179 16510twf.doc/r 此’可知本創作之變焦鏡頭具有高解像力。 ，4A與圖4B分別繪示為變焦鏡頭在望遠端及廣角端 所投影出的影像之場曲與畸變的曲線圖。請同時參照圖4八 與$ 4^，在本創作一較佳實施例中，變焦鏡頭2⑻無論是 在望退端或是在廣角端所投影出的影像之場曲（field curvature)與畸變(dist〇rti〇n)之數值皆在標準的範圍内。 圖5A與圖5B分別繪示為變焦鏡頭在望遠端及廣角端 所投影^的影像之橫向光線扇形圖，而圖6繪示為影像的 成像不意圖。請同時參照圖5A、圖5B與圖6，在圖5a 與圖5B中所綠示的_)、（b)、⑷、⑷、⑷，分別是在影 像8〇之點a、b、c、d、e所測出的橫向光線扇形圖(transverse ray jan plot)。由圖5A與圖5B可知，變焦鏡頭2〇〇無論是 望遠端或是在廣角端所投影出的影像，在點a、b、c、d、 e所測出的橫向光線扇形圖之圖形皆在標準的範圍内。 因此，由圖3A、圖3B、圖4A、圖4B、圖5A及圖 5B中所顯不出的各種圖形可知，本創作之變焦鏡頭· 具有良好的光學品質，因而能夠投射出品質佳的影像。 綜上所述，本創作之變焦鏡頭至少具有下列優點·· 1·本創作之變焦鏡頭是與習知使用數量相同之透鏡 數，也就是說本創作是在不增加生產成本的前提下，提高 變焦鏡頭的解像力，以使其能夠與〇·55吋、解析度為1〇24 Χ768的光閥搭配使用，並且相容於〇·55吋、解析度為$⑽ Χ600的光閥。換言之，解析度為8〇〇χ6〇〇及1〇2=768的 光閥可以共用本創作變焦鏡頭，進而降低投影裝置整體的 M281179 165 l〇twf.doc/r 生產成本。 2. 在本創作之變焦鏡頭中，第一透鏡 能，因此可以避免像差及成像面偏移的問題衆具影像之功 3. 本創作之變焦鏡頭是以光學屈光户為 透鏡群搭配光學屈光度為正值的第二透鈐二‘、、' 負值的第一 消除像差。而且，由於第二透鏡群滿足、進而有效地 ^因此能夠自我雜色散，細使本㈣之^=的條 有咼解像力及低像散的特性。 又〃、、鏡碩具 雖然本創作已以較佳實施例揭露如上，麸 蚊本創作，任何熟習此技藝者，在不脫離 ，些許之更動與潤飾’ 耗圍當視後附之申請專利範圍所界定者為 <保叹 【圖式簡單說明】 ° 隹供圖1Β分別繪示為習知一種變焦鏡頭在不同變 ,、、、L率下的結構示意圖。 之一 ^^^目犯分麟7"舰本购—錄實施例所述 之一種变焦叙頭在不同變焦倍率下的結構示意圖。 π圖3Α與@3Β分麟示為魏鏡财望&及 所投影出之影像的辨識率與線對數的關係圖。 八 圖4Α與圖4Β分別繪示為變焦鏡頭在望遠端及廣 所投景> 出的影像之場曲與畸變的曲線圖。 圖5Α與圖5Β分麟示為魏鏡頭在 所投影出的影像之橫向光線扇形圖。 七角鈿 圖6纟會示為影像的成像示意圖。 14 M281179 16510twf.doc/r 【主要元件符號說明】 50 :顯示元件 60 :保護鏡片 80 :影像 90、95 :光欄 • 100、200 :變焦鏡頭 110、120、130 :透鏡群 112、122、132、221、223 :透鏡 • 210 :第-透鏡群 212 :第一透鏡 214 :第二透鏡 216 :第三透鏡 218 :第四透鏡 220 :第二透鏡群 222 :複合透鏡 224 :第五透鏡 • 226 ··第六透鏡 228 :第七透鏡 229 :第八透鏡 S1〜S24 :表面 15M281179 16510twf.doc / r S11 -46.55 7 S12 25.5 3.13 1.65 33.8 S13 91.18 7.44 S14 Infinity 1.09 S15 -45.95 7 1.81 25.4 S16 33.70 0.87 S17 296.82 2.33 1.69 53.2 S18 -33.34 0.1 S19 -105.28 0 S20 40.65 2.47 1.73 51.5 -110.81 B S22 Infinity 3 S23 Infinity 0.483 1.49 70.4 S24 Infinity Table 1 Focal length (mm) A (mm) B (mm) Wide-angle end 22.31 9.339 2.056 Telephoto end 26.73 35.594 40.580 Table 2 In Table 1, the surface SI, S2 is the two surfaces of the first lens 212, surfaces S3 and S4 are the two surfaces of the second lens 214, surfaces S5 and S6 are the two surfaces of the third lens 216, and surfaces S7 and S8 are the fourth lens 218 of 11 M281179 16510twf .doc / r Surface, surface S9 is the surface of lens 221, surface S10 is the surface of lens 221 and lens 223, surface S11 is the surface of lens 223 adjacent to display element 50, and surfaces S12 and S13 are the two surfaces of fifth lens 224 . In particular, in this embodiment, a light block 90 is arranged between the fifth lens 224 and the sixth lens 226 to limit the amount of light passing through, and the surface SM is the light beam. The surface of 90 ° S15, S16 is the sixth lens The surface of 226bis, the surfaces S7, S18 are the seventh transparent | see the surface of 228bis. In addition, in this embodiment, a light barrier 95 is also arranged between the seventh φ lens 228 and the eighth lens 229, and the surface S19 is the surface of the light block 95, the surfaces S20 and S21 are the two surfaces of the eighth lens 229, and the surface S22. S23 protects the two surfaces of the lens 60, and the surface S24 is one surface of the display element 50. In addition, for the curvature radius, thickness, refractive index and dispersion value of each surface, please refer to Table 1, which will not be repeated here. In particular, the surface S8 and the surface S21 may have different thickness values at the wide-angle end, the middle position, or the far end, respectively. Table 2 lists the surface S8 and the surface S21 at the wide-angle end in one embodiment. Degree of telemetry. Art heads 3A and 3B are respectively shown as the relationship between the recognition rate and the number of line pairs of the images projected by the zoom lens at the telephoto end and the wide-angle end. Taking an image with a general resolution of 1024x768 as an example, the number of line pairs that can be displayed within a distance of 丨 millimeters is about 46, and when the number of line pairs is 牝, its recognition rate must be greater than 0 · 5 to be a specification Within the specifications, or accepted by general users: please refer to FIG. 3A and FIG. 3B at the same time. In a better practice of this creation, the zoom lens 200 is cast at the telephoto end or the wide-angle end. The resolution of the output image is still above 0.5 when the online logarithm is 46, from 12 M281179 16510twf.doc / r This shows that the zoom lens of this creation has high resolution. 4A and 4B are graphs showing the field curvature and distortion of the image projected by the zoom lens at the telephoto end and the wide-angle end, respectively. Please refer to FIG. 4 and FIG. 4 ^ at the same time. In a preferred embodiment of this creation, the zoom lens 2⑻ is field curvature and distortion (dist) of the image projected at the telephoto end or the wide-angle end. The values of 〇rti〇n) are all within the standard range. FIG. 5A and FIG. 5B respectively show the horizontal ray fan diagrams of the images projected by the zoom lens at the telephoto end and the wide-angle end, and FIG. 6 shows the imaging of the image is not intended. Please refer to FIG. 5A, FIG. 5B and FIG. 6 at the same time. _), (B), ⑷, ⑷, ⑷ shown in green in FIGS. 5a and 5B are points a, b, c, Transverse ray jan plot measured by d and e. As can be seen from FIG. 5A and FIG. 5B, whether the image projected by the zoom lens 200 at the telephoto end or at the wide-angle end, the graphs of the fan-shaped graphs of the lateral light measured at points a, b, c, d, and e are all Within the scope of the standard. Therefore, from the various graphics that are not shown in Figs. 3A, 3B, 4A, 4B, 5A, and 5B, the zoom lens of this creation has good optical quality, so it can project high-quality images . To sum up, the zoom lens of this creation has at least the following advantages ... 1. The zoom lens of this creation is the same number of lenses as the conventional one, which means that this creation is to improve the production without increasing the production cost. The resolution of the zoom lens is such that it can be used with a 0.55 inch light valve with a resolution of 1024 x768 and is compatible with a 0.55 inch light valve with a resolution of $ ⑽ χ600. In other words, the light valve with a resolution of 800 × 600 and 10 = 768 can share this creative zoom lens, thereby reducing the overall production cost of the M281179 165 ltwf.doc / r of the projection device. 2. In the zoom lens of this creation, the first lens is able to avoid the problems of aberrations and imaging plane shifts. It has many functions of imaging. 3. The zoom lens of this creation is based on an optical refractive lens group with optical The first aberrations of the second lens with a diopter of a positive value, the first lens with a negative value, and the first value with a negative value are eliminated. In addition, since the second lens group satisfies and effectively ^, it is able to self-disperse, so that the characteristics of ^ = of this lens have a high resolution and low astigmatism. You Yi, Jing Shuogu Although this creation has been disclosed in the preferred embodiment above, this glutinous mosquito creation, anyone who is familiar with this skill, will not change, a little change and retouching. The definition is < Bao sigh [Simplified description of the drawing] ° 隹 For Figure 1B, the schematic diagrams of the structure of a zoom lens with different changes,,, and L rates are shown. One is a schematic diagram of the structure of a zoom narration head at different zoom magnifications described in the embodiment described in the embodiment described in the embodiment. Fig. 3A and @ 3Β 分 麟 show the relationship between the recognition rate of the projected image and the number of line pairs. Fig. 4A and Fig. 4B respectively show the field curvature and distortion of the image produced by the zoom lens at the telephoto end and the scene >. Fig. 5A and Fig. 5B show the fan-shaped diagrams of the lateral rays of the image projected by Wei lens. Heptagonal 钿 Figure 6 纟 shows the imaging diagram of the image. 14 M281179 16510twf.doc / r [Description of main component symbols] 50: Display element 60: Protective lens 80: Image 90, 95: Light bar 100, 200: Zoom lens 110, 120, 130: Lens group 112, 122, 132 , 221, 223: Lens210: First lens group 212: First lens 214: Second lens 216: Third lens 218: Fourth lens 220: Second lens group 222: Composite lens 224: Fifth lens • 226 Sixth lens 228: seventh lens 229: eighth lens S1 to S24: surface 15