TW201039040A - Zoom projection lens - Google Patents

Abstract

The present invention provides a zoom projection lens, suitable for projection display of non-telecentric optical system or image acquisition optical system. The lens is consists of a first lens set of negative diopter and a second lens set of positive diopter, in which the first lens set is installed on the lateral side of a monitor, which may be moved along an optical axis and includes at least one plastic aspheric lens; the second lens set is installed to the plane side of the image, which may also be moved along the optical axis and includes at least one glass aspheric lens. Alternatively, an aperture diaphragm is provided between two adjacent lenses in the second lens set, which may be moved along with the second lens set at the same time. By adopting the structure of two sets of negative/positive lens set and aspheric design and meeting with certain conditions, the zoom projection lens of the present invention may achieve the features of smaller size, simple structure, lower cost, and better imaging quality, and posses longer back focal length.

Description

201039040 • 6. Description of the Invention: The present invention relates to a zoom projection lens ′, particularly a miniaturized zoom projection lens suitable for use in a non-telecentric projection display optical system or an image capture optical system. [Prior Art] Press, a device that projects an image onto a large-size screen by optical projection, and can be classified into an LCD 〇 (Liquid Crystal Display) depending on the light engine (Light Engine) used therein. Projector, DLP (Digital Light Processor) projector and LCOS (Liquid Crystal on Silicon) projector, in which the LCD projector is a transmissive projector because of the light passing through the LCD panel, while LCOS and DLP are It is developed by the principle of light reflection, so it is called a reflective projector. According to the different projection direction of the light, the projector can be divided into two types: Front Projection and Rear Projection. The front projection projector is the same side of the projector and the viewer on the screen. Separate from the screen, the rear projection projector is on the different side of the screen from the viewer. In addition, front-projection or rear-projection projectors can be divided into single-chip type, two-piece type and three-piece type depending on the number of light valves used. Among LCD, DLP and LCOS projectors, DLP projectors using Non-Telecentric System have developed rapidly in recent years, and their development trend is to achieve large screen, high definition and high in short projection distance. The image display of brightness is more capable of obtaining product characteristics such as small size and light weight. The key component of DLP projector is _ (Digital Micromirror Device) digital micro-mirror device; DMD is a digital image chip exclusively controlled and developed by Texas Instruments, USA. Due to its relatively short time, it is compatible with DMD technology. There are not many patented technologies for DLP projection imaging optical systems, and the existing projection lenses such as LCD and LCOS use the telecentric optical system, so 201039040 can not fully meet the requirements of DMD digital image chip. This is mainly because the micro mirror on the DMD has a 1 degree or 12 degree flip with the image signal during operation to reflect the light from the illumination source through the flip of the micro mirror into the entrance of the projection lens and focus. On the screen. Based on this feature, projection lenses such as LCD and LCOS usually cannot fully meet the matching requirements of DMD digital image chips. In addition, for the reflective DLP projector including the LCOS projector, in order to improve the projection quality, the interval between the incident optical path and the outgoing optical path incident on the reflective imager such as the DMD digital micromirror device is increased to form an interval. Isolation, so as to avoid the exiting light path being interfered by other light sources. Therefore, the projection lens in the projection display optical system needs to have a sufficiently long back focus (BFL). The zoom projection lens used by % mostly uses a multi-group lens group to operate and the length of each lens group is long, so it has not been in line with the trend of miniaturization of the current projector. U.S. Patent No. 6,59, 716 discloses a two-group zoom projection lens comprising a first lens group having negative refracting power, a second lens group having positive refracting power, and a third lens group having (four) luminosity. And the fourth lens group having positive refracting power, the fourth and third lens groups are fixed, and the second and third lens Ο " can be operated by 惟 惟 'because of the structure of the lens lens group of the zoom lens The penetration and the eve of the 12' lead to a longer total length of the mirror and increase the size cost and weight of the final projection machine. This is also inconsistent with the trend of miniaturization and low cost of the current projector. The zoom lens lens is only suitable for lcd, lc〇s projectors using telecentric optical systems, and is not suitable for DLP projectors using non-telecentric optical systems. In addition, 'in the lens shape and material selection of the zoom projection lens, since the traditional spherical lens has many materials, it is advantageous for the positive color recording, so it has been widely used in the industry. When the fine (4)-) is small and the angle ge) is larger, the aberrations such as spherical aberration and astigmatism are still difficult. For 4 201039040, there is _ positive aberration, as described above. 'The conventional missing shadow lens is usually made up of multiple lenses', resulting in a long read length, a large money, and a high. The fine aspherical lens can solve the problem, which can greatly improve the barrel deformation of the recording quality domain _ and the aspherical lens can replace several spherical lenses to compensate for the aberration, which can significantly simplify the optics of the lens. The design 'reduces its size and weight. 'Whether the spherical ship is a non-ball mirror, Wei Zuo material mainly has _ and plastic, in which the glass has a large transmission coefficient and good imaging effect, but the price is higher, mainly used in fine products; The light coefficient is small, the price is low, and the main surface is used for low-order production. However, because the plastic material f is light and the glass material is relatively heavy, the combination of the glass lens and the lens lens is adopted in the lens design day, thereby complementing each other. Thereby designing the desired lens group. If the _ full-valve is wealthy, it will turn the lens, and the tolerance requirements will be stricter. Therefore, 'integrated above' is how to design a zoom projection lens suitable for use in a non-telecentric projection wire system or an image capture optical system, which has a short size, a simple structure, a low cost, and a good image quality. Excellent, point, and at the same time has the characteristics of longer back focus, has become a common appeal of the industry.

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SUMMARY OF THE INVENTION The line item of the present invention is to provide a view-and-observation image, which can be a non-telecentric projection display optical system or a photonic optical system, which has the characteristics of short size, simple structure, low cost, and good image quality. . Another object of the present invention is to read the projection display optical system of the New Zealand program. A further object of the present invention is to provide an optical system with an image of the 掏 201039040. According to the main purpose of the present invention, the zoom projection program can be finer than the non-telecentric projection display optical subtraction or image capture optical button, which is composed of a first lens group having a negative refracting power and a second lens having a positive refracting power. She becomes, the towel-lens group is set on the screen side. It can be: 3⁄4 optical axis shifting contains at least one flap aspherical lens; the second lens set is set in the like It also contains at least a sinus spherical lens. An aperture stop is further disposed between two adjacent lenses of the second lens group, and the aperture stop can move together with the second lens group. The zoom projection lens satisfies the following conditional expression: f2 - 0.75 <g<-〇_46; fl _3·0<^-<-ΐ.6〇; and rw f2 L20<-<1.40 fw where 'f lens The focal length of the group, the focal length of the second lens group of £2, is added as the focal length of the zoom projection lens as a whole at the wide-angle end. According to the Wei-Yi lens of the first embodiment of the present invention, the first lens group includes a crescent-shaped Wei mirror and a new (four) positive lens along the optical order from the screen side to the image plane side, wherein the crescent-shaped positive lens Lin-Na aspherical lens, the second lens from the screen side to the image plane side along the optical axis sequentially includes a new positive Wei, a double concave transparent - plano-convex lens, wherein the double concave lens system - glass fringe lens. The aperture stop is disposed between the crescent-shaped positive lens of the second lens group and the biconcave lens. According to the zoom projection lens of the second embodiment of the present invention, the first lens group sequentially includes a crescent-shaped negative lens and a crescent-shaped positive lens along the optical axis from the silk side to the image plane side, wherein the 201039040 crescent type Positive lens system - plastic aspheric lens. The second lens group sequentially includes a - lenticular lens, a crescent-shaped positive lens, a double-shot mirror and a first-lenticular lens from the screen side to the image plane side along the optical axis. Lin - glass scale spherical Wei. The aperture diaphragm is disposed between the third ship and the double concave lens. According to a third embodiment of the present invention, the first lens group includes a __ crescent-type negative lens and a composite lens along the optical axis from the screen side to the image plane side, wherein the composite lens is composed of - The double concave lens is joined to a lenticular lens, and the crescent-shaped negative lens is a plastic aspherical surface. The second wei _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Dear. The aperture light is disposed between the crescent-shaped positive lens of the second lens group and the biconcave lens. The zoom projection lens of the three embodiments of the present invention further satisfies the following conditional formula: 0.75 < - < 0.84 ϊ ◎ 3.50 < — <3.84 fw 2.79 <^< 2.96 ex 1.43<-<-1.20 ; ^ 0.625 <-<0.663 tt where fW is the focal length of the zoom projection lens as a whole at the wide-angle end, bf is the focal length of the zoom projection lens, and tt is the total length of the optical system of the zoom projection lens, ex is The change 7 201039040 focal projection mirror Lai Mi out of position 4, It is the head of the zoom projection. ❹

Compared with the prior art, the zoom projection lens of the present invention has only two sets of lens groups whose refractive powers are negative and positive respectively, including only 5 to 7 lenses, and therefore has a short size, a simple structure, and a low cost. By making at least the combination of the face and the ray, the combination of the lens, and the satisfaction of the specific conditional formula, the various aberrations can be effectively bridged while reducing the total length of the frame. Therefore, the present invention Wei Yu Zhi Lin Yu Zhipin [In addition, the zoom fiberglass of the present invention has a longer focus and is not as good as a money-based projector such as a DLP, and has a New Focus image." It is used in the display light system of the DLP projector, such as the DLP projector, to project the image on the imager onto the screen. The detailed description of the preferred embodiment of the reference pattern of the _, _, and _, _, _, _, _, _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Head from the screen side (corresponding to the first, Γ_, one _ side ==; side: The first refractive power - lens group G1 and - means screen image having a positive refractive power of the second lens group (iv) may ⑻ ... projected thereon a flat 'Ming and

The setting of the digital micro-mirror H piece. 'And the county secret domain like the following D first lens group G1 can move along the optical axis ,, mirror U two lenses, the first lens lens = L1 and the second through the 罘 罘 mirror L2 form For a new moon 8 201039040 type negative lens and a crescent type positive lens. The crescent-type negative lens L1 is made of a global glass frit material having a convex surface R1 on the screen side and a concave surface R2 on the image plane side. The crescent-shaped positive lens L2 is a plastic aspherical lens which is formed by injection molding and has a concave surface on the screen side and a convex surface R4 on the image plane side. Preferably, the crescent-shaped positive lens L2_face R3 and the convex surface R4 are aspherical. Ο

The first lens group G2 can also be moved along the optical axis OA. It is composed of three lenses of a third lens L3, a fourth lens Μ and a fifth lens. The lenses, which are made of a full-surface glass nitrate material, are in the form of a crescent-shaped positive lens, a biconcave lens and a plano-convex lens. Wherein, the crescent-shaped positive lens L3 has a convex surface R5 on the screen side and a concave surface R6 on the image plane side, and the double concave lens L4 has a concave R8 on the side of a concave surface of the image of the concave screen. The plano-convex lens L5 has a plane R9 on the side of the image plane and a convex surface R1〇 on the side of the image plane. The biconcave lens W is a glass aspherical lens made by a glass mold type method, and its concave and convex are preferably aspherical. The crescent-shaped positive lens 匕3 of the first lens group G2 and the biconcave lens w are additionally provided with a hole-controlling optical ST, which can be knee-length _, tyra 4 wide, and m ventilated G2 - lifting crane. A glass breaking plate GP is provided between the second penetrating age G2 and the face 1P (i.e., the imager). - Change of the example of the embodiment _ For each lens parameter, refer to the table below. "On behalf of the wide-angle end, · "Μ" stands for "surface number", looking far end. ·, represents the fine coefficient or F value of the lens; (Refer to the first - · "/ ^ 12 according to: the surface of the screen to touch the face of each lens surface / thickness version of the translating _ turn;" The optical lens is measured by the adjacent lens along the field 0Α, or the heart represents the two lenses (4), which represents 201039040 Table 1 F 21.2296(W)~22.2459fM)~23.2667(T) ~~-- Fno.=2. 57(W)~2.60( Μ)~2.64(Τ) - Surface No. Curvature Radius R(mm) Distance/Thickness D(mm) Refractive Index Nd Abbe Coefficient Vd 59 46 R1 102.70 1.5 1.539956 R2 15.27 12.85 R3 -92.70 7.5 1-524670 56 40 R4 -37.30 9.659251(W)~5.678908(M)~2.030964m 1^772499 49.60 23.59 R5 15.42 ' 5.3 R6 104.0 5.60 R7 -31.57 0.9 1-844630 R8 OS QC\ 4 54.68 U----_1_ 2.1 ~· 1 7〇αι c^7 —~-- 1 · /Zy1j/ Rll R12 1.05 1-487490 70.24 、 , as in the 'Beneficial' - Preferably, the two-surface lens of the crescent-shaped convex lens 匕2 of the first lens group G1 and the two surfaces rj and R8 of the lens 14 of the second lens group (5) are aspherical. The aspherical design formulas are expressed as follows: η =--CH2 4 ❹ 1 + + Ε4 ·H + Ε6 · H6 + E8 Η8 + Εω . H1. + E12. H12 + E14. Η :^ The amount of silk in the height ^ is the surface of the reference as the reference value from the optical axis = κ is the taper constant; CMIR is the radius of curvature: (10) the height of the lens; the aspheric coefficient of 2; E6 represents six times of the aspheric surface age table eight times, the number, E extinction and tenderness; E, 2 silk busy marriage _ number; u represents fourteen aspheric coefficients. Table II. u, related parameters of the respective aspherical surfaces of the zoom projection lens of the first embodiment of the present invention. 201039040 Table 2 Surface No. K e4 e6 Eg El〇En R3 -11.1665 8.75E-06 5.22E-08 -8.65E-10 2.93E-12 〇j«/14 〇R4 2.833118 3.56E-06 -8.90E-11 - 5.19E-10 1.62E-12 〇〇R7 7.546776 2.69E-07 1.78E-07 -2.20E-08 5.70E-10 0 〇R8 3.175439 7.18E-05 •4.57E-07 -1.33E-08 4.68E- 10 0 0 Design according to the parameters listed in Table 1 and Table 1, such as the second A to the second map (various aberration diagrams at the wide-angle end), and the third to third E maps (the intermediate angle ends The zoom projection lens of the first embodiment of the present invention shows various images at the wide angle end, the intermediate angle end, and the telephoto end, as shown in the aberration diagrams of the fourth and fourth diagrams (the aberration diagrams at the telephoto end). Poor bridges are good. The second A, the third A, and the fourth A diagram respectively show the longitudinal spherical aberration (longitudinal Spherical Aberration) performance of the zoom projection lens of the first embodiment of the present invention at the wide angle end, the intermediate angle end, and the telephoto end; b and FIG. 4B respectively show the lateral color difference performance of the zoom projection lens of the first embodiment of the present invention at the wide angle end, the intermediate angle end and the telephoto end; the second C, the third C and the fourth c diagram respectively show the present invention. The zoom projection lens of the first embodiment is represented by FieldCmvature at the wide-angle end, the intermediate apex end, and the telephoto end; and the second D, three, and four D-graphs respectively show the zoom projection lens of the first embodiment of the present invention The mtf ❹ modulation modulation transfer characteristic curve at the wide angle end, the intermediate angle end and the telephoto end shows that the zoom projection lens of the first embodiment of the present invention has good contrast characteristics and resolution performance. Second Embodiment Please refer to the second embodiment of the zoom projection lens of the present invention shown in FIG. 5, which is structurally different from the first embodiment shown in the first figure in the composition of the second lens group (5). different. In the second embodiment, the second lens, group G2 is composed of four lenses, and includes a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6. The lenses L3, ^, L5 and L6 are also made of global handle glass, and are in the form of a lenticular lens, a 201039040-crescent positive lens, a double concave lens and a second lenticular lens. The aperture stop sT is disposed between the crescent-shaped positive lens L4 and the biconcave lens L5 and is movable together with the second lens group G2. The lens parameters of the zoom projection lens of the second embodiment of the present invention can be referred to the following Table 3.

〇.5(WH · 287870(Μ)~2.098157(T) 四 四 Table 4 shows the relevant parameters of the aspheric surfaces of the zoom projection lens of the second embodiment of the present invention. -E6 e8 Ειο Εΐ2 Eh 4.21E- 08 -3.50E-10 1.03Ε-12 0 0 J.19E-08 ^4.26E-08 68E-07— -1.35E-10 3.94Ε-13 0 0 -6.87E-09 1.60Ε-10 -7.84Ε -13 0 -6.78E-09 8.83Ε-11 7.17Ε-14 0 As shown in Table 4, in the zoom projection lens of the second embodiment of the present invention, the surface number of the first lens group is ~R3~R12 12 201039040 Both surfaces of the convex lens L2 and the two surfaces Rn and R12 of the second lenticular lens L6 from which the second lens is sensitive are aspherical. Preferably, the crescent-shaped L2 is a Wei surface which is hidden by the radiation field. Ship, the double convex Wei l glass mold caused by a glass aspheric lens. Design according to the parameters listed in Table 3 and Table 4, such as the sixth gray figure to the sixth _ (wide-angle end of each picture ), the seventh A to the figure (the middle angle _ each image 1 table _ and the eighth picture to the person Ε diagram (distal end aberration performance map), the second real invention

The variation of the shadow lens of the embodiment can obtain better image quality at the wide-angle end, the intermediate angle end and the telephoto end to have good correction performance for various aberrations. a third embodiment, please refer to the third embodiment of the miniature image taking lens of the present invention shown in the ninth figure, which is structurally different from the second embodiment of the fifth figure in the first lens group. The composition of (7) is different. In the third embodiment, the _ lens group (1) is composed of three lenses, including a crescent-shaped negative lens L1, a biconcave lens L2, and a lenticular lens u, wherein the biconcave lens L2 and the double & lens U The system is made of global glass and joined together to form a composite lens. The new negative lens! ^ is a non-spherical nano lens. The lens parameters of the zoom projection lens according to the third embodiment of the present invention can be referred to the following table. 5 13 201039040 Table 5 F=21.6032(W)~22.6674(M)~23.7727(T) --- Fno.= 2 L56( W)~2.62 (M)~2.69('l) One~- Surface No. Curvature Radius R(mm) Distance/Thickness D(mm) Refractive Index Nd Abbe's Coefficient Vd R1 73.08 2,33 1.524670 56.40 R2 15.41 15.89 R3 - 22.61 1.0 1.548141 45.78 R4 52.82 4.24 1.834807 42.72 R5 -52.83 5.041052,(W)~1.348456nvi)~2.229454(7) R6 31.46 4.10 1.496999 81.61 R7 -111.17 0.10 R8^ 21.68 2.18 1.788001 47.39 R9 37.74 12.19 R10 -21.69122 0.6 1.846659 23.78 R11 35.40287 0.37 R12 30.21111 3.967 1.801910 40.89 R13 -18.20589 24.5 R14 〇〇3.0 1.487490 70.21 R15 〇〇0.5(W)~1.348456(M)~2.229454(T) Table 6 shows each of the zoom projection lenses of the third embodiment of the present invention. Related parameters for aspheric surfaces. Table six face number K ε4 ε6 Eg Ει〇Εΐ2 Εη R1 11.42132 1.22Ε-04 9.99Ε-06 9.78Ε-09 1.62Ε-11 8.30Ε-15 3.83Ε-17 R2 0.113487 1.04Ε-04 5.22Ε-06 2.64Ε -07 2.96Ε-09 4.19Ε-12 9.43Ε-14 R12 -12.3734 4.10Ε-04 9.92Ε-05 8.31Ε-07 6.93Ε-08 9.76Ε-10 0 R13 -0.13055 9.74Ε-03 5.54Ε-05 3.39 Ε-07 6.23Ε-08 9.44Ε-10 0 As shown in Table 6, in the zoom projection lens according to the third embodiment of the present invention, both surfaces R1, R2 and the first surface of the crescent-shaped negative lens L1 of the first lens group G1 Both surfaces R12 and R13 of the lenticular lens of the two lens group G2, that is, the seventh lens L7 are aspherical. Preferably, the crescent-shaped negative lens L1 is a plastic aspherical lens made by injection molding, and the lenticular lens L7 is a glass aspherical lens made by a glass mold forming method. 14 201039040 Design according to the parameters listed in Tables 5 and 6, such as Figure 10A to Figure +E (various aberration diagrams at the wide-angle end), Figure 11A to Figure 1E (intermediate angle ends) The zoom projection lens of the third embodiment of the present invention is shown at the wide-angle end, the intermediate-angle end, and the telephoto end, as shown in the aberration diagrams of the twelfth and the twelfth to the eleventh (the telephoto performance diagrams at the telephoto end). Various aberrations have good corrective performance and better image quality. As is broadly understood from the above three embodiments, the zoom projection lens of the present invention is composed only of a first lens group G1 of negative diopter and a second lens group G2 of positive refracting power, wherein the lens group G1 includes a grazing plastic aspherical surface. The lens (in each of the three embodiments, a crescent-shaped positive lens L2, a crescent-type positive lens L2, and a crescent-type negative lens), and the second lens group G2 includes a glass aspheric lens (in three implementations) In the examples, a biconcave lens, a lenticular lens L6 and a lenticular lens L7) are respectively provided with an aperture stop st between two adjacent lenses. Preferably, the aspherical lenses [the surface side surface of the L2, L4, L6, and L7 and the image plane side surface 胄 are aspherical. The hairpin mirror is made up of the gryphon and the two sets of lens group structure. It can greatly reduce the length of the mirror, reduce the assembly and manufacturing cost of the weaving head and effectively correct various aberrations, thus obtaining a short size and structure. A zoom projection lens that is simple, low cost, and has good image quality. In the above three embodiments of the zoom projection lens of the present invention, the first lens group G1 includes only one plastic aspheric lens, and the second lens group G2 also includes only one glass aspheric lens. Breaking the mirror, with the combination of the glass and the plastic lens, the number of lenses is greatly reduced and the best effect of various aberrations is effectively corrected. However, the invention is not limited thereto. The first lens group G1 may also include one or more plastic aspherical lenses. The second lens 2 may also include a glass aspheric lens. The effect of temperature change on the optical properties of a plastic aspheric lens can be achieved by the front and back spacing of the lens group or the mirror-printed silk, which avoids the phenomenon of image quality degradation caused by temperature changes. 15 201039040 f2 —0.75 < — < —0.46 fl (1) fl — 3.0 < — < —1.60 (2) /S v fw f9 1.20<if<l.40 (3) fw

Where 'fi is the focal length of the first lens group G1, and β is the focal length of the second lens group G2, and the speculation is the same as the distance between the two. . As shown in the mirror structure of the first to second figures, the changes of the three embodiments of the present invention, d, and the heart mirror have a long focal length, and the back focal length refers to the final surface - the microfilament to the image plane The distance of IP. For example, in the first embodiment shown in the first figure, the back focus refers to the distance between the plane R10 of the plano-convex lens L5 to the image plane π. This longer post-focus system is adapted to the need for reflective or non-telecentric system projectors such as DLP projectors to require an increased spacing between the incident and outgoing optical paths. For image capture optics, longer post-focus can be used to place additional optics such as light-collecting prisms and IR filters for better optical performance. The zoom projection lens of the three embodiments of the present invention satisfies the following conditional formulas (4) to (6) at the wide-angle end: 〇.75<P<〇84 (4) 3.50<JL fw <3.84

16 201039040 2·79<·~<2.96 (6) The towel ' ^ is the focus of the Weitou head of the invention as the focal length of the wide angle end, bf is the focal length of the zoom projection of the present invention, tt is the zoom of the present invention The total length of the optical system of the projection mirror (refers to the distance between the hiding side surface of the first lens and the image plane Ip). Satisfying the above conditional expressions (4) to (4) can significantly lengthen the back focus of the zoom projection lens of the present invention in a wide-angle state, and can also effectively reduce the total length of the lens and correct various aberrations. The zoom projection lens of the three embodiments of the present invention further satisfies the following conditional expressions (7) and (8): ~L43<^<-1·20 (7) 0.625 ^ ~ < 0.663 ( 8 ) wherein ' ex is Inventing the zoom position of the zoom projection lens, bf is the back focus length of the zoom projection lens of the present invention, which is the total length of the zoom lens of the present invention (refers to the image plane of the first lens to the image plane of the last lens) The distance of the side surface), Du Weiqi The total length of the optical system of the zoom projection lens of the present invention. Satisfying the conditional expressions (7) and (8) can also effectively reduce the total lens length of the zoom projection lens of the present invention and increase the back focus length. In summary, compared with the conventional art, the zoom projection lens of the present invention is composed only of two sets of lens groups G1 and G2 whose refractive powers are respectively negative and positive, and includes only 5 to 7 lenses, so that the size is corrected. The advantages of simple display and low cost; by using at least two aspherical lenses combined with glass and lobed lenses, and the satisfaction of specific conditional expressions, various aberrations can be effectively corrected while reducing the total length of the lens. The zoom projection lens of the present invention also has better imaging quality. In addition, the zoom projection lens of the present invention also has a long back focus, which is suitable for non-telecentric systems or reflective applications such as DLP voting and images with long back focus requirements. The zoom projection lens of the present invention can be applied to a front projection projector of a non-telecentric system, especially a DLP projector, which not only miniaturizes the projector, but also improves device performance to obtain high quality images. In addition, the zoom projection lens of the present invention can also be applied to an image capturing optical system to reduce the total length of the light (4) and improve its optical performance. In fact, the zoom projection lenses disclosed in the three embodiments of the present invention all constitute an inverted telephoto structure, wherein the screen side (ie, the plane on which the image can be projected) can be used as an image plane, and the image plane side (ie, The surface of the display device, such as the DMD imager, can be used as a surface. However, when the optical performance of the zoom projection lens is evaluated on the display device side, the screen side is regarded as an object surface, and the zoom projection lens J is regarded as a fine shadow optical system (r〇S, Reduction Optical). System). In summary, the present invention has indeed met the requirements of the invention patent and has filed a patent application in accordance with the law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art to the spirit of the present invention are included in the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a schematic view showing the optical structure of a zoom projection lens according to a first embodiment of the present invention. The second A to the second E ® are schematic diagrams of the longitudinal spherical aberration, the lateral chromatic aberration, the field curvature, the distortion, and the MTF curve of the zoom steel of the first embodiment of the present invention at the wide angle end, respectively. The second to third E-graphs are schematic diagrams of longitudinal spherical aberration, lateral chromatic aberration, curvature of field, distortion, and MTF curve when the zoom projection lens of the first embodiment of the present invention is located at the intermediate angular end. The fourth to fourth E diagrams respectively illustrate the longitudinal spherical aberration, lateral chromatic aberration, field curvature, distortion, and MTF curve of the frog mirror at the telephoto end of the present embodiment. Fig. 5 is a schematic view showing the optical structure of a zoom projection lens according to a second embodiment of the present invention. 201039040 The present invention is a schematic diagram of the longitudinal, lateral chromatic aberration, curvature of field, distortion and secret of the zoom projection lens of the third embodiment of the present invention. The seventh to seventh E ® are the schematic diagrams of the longitudinal spherical aberration, lateral chromatic aberration, field curvature, distortion and MTF curve at the end of the speech. Eighth A to Eight E ® (4) Schematic diagrams of the longitudinal spherical aberration, the lateral chromatic aberration, the curvature of field, the distortion, and the curve of the zoom projection of the second embodiment of the present invention at the telephoto end. Figure 9 is a schematic view showing the optical structure of the photographic mirror of the third embodiment of the present invention.

10A to 10E are respectively schematic diagrams of longitudinal spherical aberration, lateral chromatic aberration, lion, distortion, and MTF curve when the photographic frame of the third embodiment of the present invention is located at the wide-angle end. The tenth through tenth to tenth-thth views are schematic diagrams of the longitudinal spherical aberration, the lateral chromatic aberration, the field curvature, the distortion, and the MTF curve when the zoom projection lens of the third embodiment of the present invention is located at the intermediate angle end.

The tenth-A to ten-E diagrams of the third embodiment of the zoom projection are located at the telephoto end of the longitudinal spherical aberration, lateral chromatic aberration, curvature of field, distortion and MTF curve. [Major component symbol description] First lens group G1 Second lens group G2 First lens L1 Second lens L2 Third lens L3 Fourth lens L4 Fifth lens L5 Sixth lens L6 Seventh lens L7 Aperture stop ST Glass plate GP image plane IP Ο 201039040 R1-R15 Optical axis OA lens surface

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Claims (1)

201039040 VII. Patent application scope······································································ An at least one plastic aspherical lens may be included along the optical axis; the second lens group is disposed on the image plane side 'which may also move along the optical axis and include at least one grazing aspherical lens; Its towel __ offers another room - Liguang Pavilion, the hole The path pupil can be moved together with the second lens group; the zoom projection lens satisfies the following conditional expression: -0.75 &lt;ί?&lt;-0.46; fl ~3·0&lt;^:&lt;-1·6〇» A. 1.2〇&lt;£&lt;1·40, where 'fl is the focal length of the first lens group, and β is the focal length of the second lens group, which is the focal length of the zoom projection lens as a whole. 2. If applying for the general projection of the Wei projection lens as described in the item [to (4), she is in accordance with the touch object], the zoom lens of the first lens group as described in claim 2, the new moon The positive lens is a plastic aspheric lens. The lens 'where the second lens group includes a crescent lens from the crescent-shaped positive lens, the double-concave lens 4, as shown in the second aspect of the patent application, from the zoom projection screen side to the image plane side along the optical axis. The method of claim 4, wherein the double-lens lens-glass non-spherical lens is the zoom lens projection lens of the second lens group, wherein the aperture stop is configured Between the crescent-shaped positive lens and the biconcave lens. 7. The zoom projection lens of item 2, wherein the second lens group sequentially includes a - lenticular lens, a crescent-type positive lens, a double concave lens, and - from the shell side of the shell. Second lenticular lens. Ο 8. The zoom projection lens of claim 7, wherein the first lenticular lens of the second lens group is a glass aspheric lens. The zoom projection lens of claim 7, wherein the aperture light is disposed between the crescent-shaped positive lens of the second lens group and the biconcave lens. 10. The zoom projection lens of claim 1, wherein the first lens group sequentially includes a crescent-shaped negative lens and a composite lens and a pair along the optical axis from the screen side to the image plane side. The convex lenses are joined to each other. The zoom projection lens of claim 10, wherein the crescent-type negative lens of the first lens group is a plastic aspheric lens. The zoom projection lens of claim 1, wherein the second lens group sequentially includes a first lenticular lens, a crescent-shaped positive lens, and a pair along the optical axis from the screen side to the image plane side. a concave lens and a second lenticular lens. The zoom projection lens of claim 12, wherein the second lenticular lens of the second lens group is a glass aspheric lens. The zoom projection lens of claim 12, wherein the aperture stop 22 201039040 is disposed on the crescent lens of the second lens and the biconcave lens 15. As claimed in the patent scope The item 4...the mirror item 'more satisfies the following conditional expression α75&lt;ϊ7&lt;α84, where fw is the focal length of the zoom projection lens as the whole mountain focus projection lens. The angle ~ the focal length 'bf is the change. [6· If you apply for the patent program! Item #, _, "Sentence conditional: Ο 17 3.50&lt;--&lt;3.84 rw Among them, "for this zoom projection lens as - overall in editing... first ''long, fW for the zoom projection lens as - overall The focal length at the wide end. If you apply for the first touch of the zoom projection 2.79 &lt; .2.96 lens 'more satisfies the following conditions: Ο 18 where tt is the focal length of the zoom lens. + system total length, bf is the zoom projection lens. As described in the patent scope range item i: the zoom "mirror master, more satisfy the following _L43" ^ < 1.20 where 'for the zoom projection lens Back focal length. Jian, bf engage zoom projection lens 19 = The zoom projection lens described in the first paragraph of the patent range, more meet the following 23 201039040 0.625 &lt;-&lt;0.663 tt where It is the total length of the lens of the zoom projection lens, and tt is the total length of the optical system of the zoom projection lens. twenty four