projection lens

Abstract

A projection lens includes a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group. The first lens group has negative refractive power. The second, third, and sixth lens groups have positive refractive power. The fourth and fifth lens groups have refractive power. The first, second, third, fourth, fifth, and sixth lens groups are arranged sequentially along the optical axis from the projection side to the image source side. The first lens group includes lens 1-1 and lens 1-2, where lens 1-1 is a meniscus lens and lens 1-2 is a biconcave lens. The fourth lens group includes lens 4-1, which is a biconvex lens. The fifth lens group includes a cemented lens. The sixth lens group includes lens 6-1, which has positive refractive power and includes a concave surface or a flat surface facing the projection side and a convex surface facing the image source side.

Description

Technical Field

[0001] This invention relates to a projection lens. Background Technology

[0002] The current trend in projection lens development is towards larger field of view and larger aperture. In order to improve installation flexibility and achieve variable projection screen size (with a fixed projector position), projection lenses also need to have optical zoom capabilities. Existing projection lenses can no longer meet current needs, and a new type of projection lens architecture is required to simultaneously meet the requirements of large field of view, large aperture, and optical zoom. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a projection lens that has a large field of view, a small aperture value, and optical zoom capability, while still having good optical performance, in order to address the above-mentioned deficiencies of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is to provide a projection lens comprising a first lens group, a second lens group, a third lens group, a fourth lens group, a fifth lens group, and a sixth lens group. The first lens group has negative refractive power. The second lens group has positive refractive power. The third lens group has positive refractive power. The fourth lens group has refractive power. The fifth lens group has refractive power. The sixth lens group has positive refractive power. The first, second, third, fourth, fifth, and sixth lens groups are arranged sequentially along the optical axis from the projection side to the image source side. The first lens group includes lens 1-1 and lens 1-2. Lens 1-1 is a meniscus lens, and lens 1-2 is a biconcave lens, including one concave surface facing the projection side and another concave surface facing the image source side. Lens 1-1 and lens 1-2 are arranged sequentially along the optical axis from the projection side to the image source side. The fifth lens group includes a cemented lens. The sixth lens group includes a 6-1 lens, which has positive refractive power and includes a concave surface or a flat surface facing the projection side and a convex surface facing the image source side.

[0005] Lens 1-1 has negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side; lens 1-2 has negative refractive power; the second lens group includes lens 2-1, which has positive refractive power and includes a convex surface facing the image source side; the third lens group includes lens 3-1, which has positive refractive power and includes a convex surface facing the projection side; the fourth lens group includes lens 4-1 and lens 4-2, where lens 4-1 is a biconvex lens with positive refractive power, and lens 4-2 has... The fifth lens group may further include a 5-3 lens, which is a biconvex lens with positive refractive power and includes one convex surface facing the projection side and another convex surface facing the image source side. The cemented lens has negative refractive power and includes a 5-1 lens and a 5-2 lens. The 5-1 lens is a biconcave lens with negative refractive power and includes one concave surface facing the projection side and another concave surface facing the image source side. The 5-2 lens is a biconvex lens with positive refractive power and includes one convex surface facing the projection side and another convex surface facing the image source side.

[0006] Lens 2-1 is a plano-convex lens and may further include a plane facing the projection side; lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side; the fourth lens group has positive refractive power; lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side; the fifth lens group has negative refractive power; and lenses 1-1, 1-2, 2-1, 3-1, 4-2, 4-1, 5-1, 5-2, and 5-3, and lens 6-1 are arranged sequentially along the optical axis from the projection side to the image source side.

[0007] Lens 2-1 is a biconvex lens and may further include a convex surface facing the projection side; lens 3-1 is a meniscus lens and may further include a concave surface facing the image source side; the fourth lens group has negative refractive power; lens 4-2 is a biconcave lens and includes a concave surface facing the projection side and another concave surface facing the image source side; lens 4-2 is cemented with lens 4-1; the fifth lens group has positive refractive power; and lenses 1-1, 1-2, 2-1, 3-1, 4-2, 4-1, 5-1, 5-2, 5-3, and 6-1 are arranged sequentially along the optical axis from the projection side to the image source side.

[0008] The first lens group may further include lenses 1-3 disposed between the projection side and lens 1-1, and lens 1-4 disposed between lens 1-1 and lens 1-2. Lens 1-3 is a meniscus lens with positive refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 1-4 is a meniscus lens with negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. The second lens group may further include lens 2-2 disposed between lens 2-1 and the third lens group. Lens 2-1 is a meniscus lens and may further include a concave surface facing the projection side. Lens 2-2 is biconvex. The lens has positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source side. Lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side. The fourth lens group has positive refractive power and may further include lens 4-3 disposed between lens 4-1 and the fifth lens group. Lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 4-3 is a meniscus lens with negative refractive power and includes a concave surface facing the projection side and a convex surface facing the image source side. Lens 4-1 and lens 4-3 are cemented together. The fifth lens group has negative refractive power.

[0009] The first lens group may further include lens 1-3 disposed between the projection side and lens 1-1. Lens 1-3 is a meniscus lens with positive refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. The second lens group may further include lens 2-2 disposed between lens 2-1 and the third lens group. Lens 2-1 is a meniscus lens and may further include a concave surface facing the projection side. Lens 2-2 is a biconvex lens with positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source. On one side, lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side; the fourth lens group has positive refractive power and may further include lens 4-3 disposed between lens 4-1 and the fifth lens group; lens 4-2 is a biconcave lens and includes a concave surface facing the projection side and another concave surface facing the image source side; lens 4-3 is a meniscus lens with negative refractive power and includes a concave surface facing the projection side and a convex surface facing the image source side; lens 4-1 and lens 4-3 are cemented together; and the fifth lens group has negative refractive power.

[0010] The first lens group may further include lens 1-3 disposed between the projection side and lens 1-1. Lens 1-3 is a meniscus lens with negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. The second lens group may further include lens 2-2 disposed between lens 2-1 and the third lens group. Lens 2-1 is a meniscus lens and may further include a concave surface facing the projection side. Lens 2-2 is a biconvex lens with positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source side. Lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side. The fourth lens group has negative refractive power and may further include lens 4-3 disposed between lens 4-1 and the fifth lens group. Lens 4-2 is a meniscus lens and includes a concave surface facing the projection side and a convex surface facing the image source side. Lens 4-3 is a meniscus lens with negative refractive power and includes a concave surface facing the projection side and a convex surface facing the image source side. Lens 4-1 and lens 4-3 are cemented together. The fifth lens group has positive refractive power.

[0011] The first lens group may further include lens 1-3 disposed between the projection side and lens 1-1, and lens 1-4 disposed between lens 1-3 and lens 1-1. Lens 1-3 is a meniscus lens with negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 1-4 is a meniscus lens with positive refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 2-1 is a biconvex lens and may further include a convex surface facing the projection side. Lens 3-1 is a meniscus lens and may further include a concave surface facing the image source side. The fourth lens group has positive refractive power. Lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 4-2 and lens 4-1 are cemented together. The fifth lens group has positive refractive power.

[0012] The first lens group may further include lenses 1-3 disposed between the projection side and lens 1-1. Lenses 1-3 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. Lens 2-1 is a meniscus lens and may further include a concave surface facing the projection side. Lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side. The fourth lens group has positive refractive power. Lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 4-2 is cemented with lens 4-1. The fifth lens group has negative refractive power.

[0013] The first lens group may further include lenses 1-3 disposed between the projection side and lens 1-1, and lens 1-4 disposed between lens 1-1 and lens 1-2. Lens 1-3 is a meniscus lens with positive refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 1-4 is a meniscus lens with negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. The second lens group may further include lens 2-2 disposed between lens 2-1 and the third lens group. Lens 2-1 is a meniscus lens and may further include a concave surface facing the projection side. Lens 2-2 is a biconvex lens and includes a convex surface facing the projection side and another convex surface facing the image source side. Lens 3-1 is a biconvex lens and may further include a convex surface facing the image source side. The fourth lens group has positive refractive power. Lens 4-2 is a biconcave lens and includes a concave surface facing the projection side and another concave surface facing the image source side. The fifth lens group has positive refractive power.

[0014] The first lens group may further include lens 1-3 disposed between the projection side and lens 1-1. Lens 1-3 is a biconvex lens with positive refractive power and includes one convex surface facing the projection side and another convex surface facing the image source side. The second lens group may further include lens 2-2 disposed between lens 2-1 and the third lens group. Lens 2-1 is a meniscus lens and may further include one concave surface facing the projection side. Lens 2-2 is a meniscus lens with positive refractive power and includes one convex surface facing the projection side and one concave surface facing the image source side. Lens 3-1 is a biconvex lens and may further include one convex surface facing the image source side. The fourth lens group has negative refractive power. Lens 4-2 is a biconcave lens and includes one concave surface facing the projection side and another concave surface facing the image source side. The fifth lens group has positive refractive power.

[0015] The projection lens must satisfy at least one of the following conditions: 6.02 <TTL / f<23.34;3.84<TTL / BFL<5.85;-5.28<fCL / f<-1.17;1<(R 6-11 +R 6-12 ) / (R 6-11 -R 6-12 <1.5; -1.51 <R 6-12 / BFL<-0.88; Vd6-1<21; -1.06 <fCL / f LG6 <-0.48; where TTL is the distance from the projection side of the lens closest to the projection side to the optical axis of an image source, BFL is the distance from the image source side of the 6-1 lens to the optical axis of the image source, f is the effective focal length of the projection lens, fCL is the effective focal length of the cemented lens, and R 6-11 R is the radius of curvature of the projected side surface of the 6-1 lens. 6-12 Let Vd6-1 be the radius of curvature of the image source side of the 6-1 lens, and f be the Abbe coefficient of the 6-1 lens.LG6 This is the effective focal length of the sixth lens group.

[0016] The spacing between these lens groups can be changed to allow the projection lens to zoom from the wide-angle end to the telephoto end. When the projection lens zooms, the first lens group is fixed or moves along the optical axis towards the image source side, the second lens group moves along the optical axis towards the projection side, the third lens group moves along the optical axis towards the projection side, the fourth lens group moves along the optical axis towards the projection side, the fifth lens group moves along the optical axis towards the projection side, and the sixth lens group is fixed. The aperture moves with the third lens group, moves with the fourth lens group, or moves independently. The first lens group can move along the optical axis to allow the projection lens to focus.

[0017] The projection lens implementing this invention has a large field of view, a small aperture value, and optical zoom capability, but still has good optical performance. Attached Figure Description

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the first embodiment of the projection lens according to the present invention.

[0020] Figure 2A , 2B Figures 2C and 2D are field curvature, distortion, modulation transfer function, and through focus modulation transfer function diagrams at the wide-angle end of the first embodiment of the projection lens according to the present invention.

[0021] Figure 3A , 3B 3C and 3D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance according to the first embodiment of the projection lens of the present invention.

[0022] Figure 4 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the second embodiment of the projection lens according to the present invention.

[0023] Figure 5A , 5B 5C and 5D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the second embodiment of the projection lens according to the present invention.

[0024] Figure 6A , 6B 6C and 6D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance according to a second embodiment of the projection lens of the present invention.

[0025] Figure 7 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the projection lens according to the third embodiment of the present invention.

[0026] Figure 8A , 8B 8C and 8D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the third embodiment of the projection lens according to the present invention.

[0027] Figure 9A , 9B 9C and 9D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the third embodiment of the projection lens according to the present invention.

[0028] Figure 10 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the fourth embodiment of the projection lens according to the present invention.

[0029] Figure 11A , 11B 11C and 11D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the fourth embodiment of the projection lens according to the present invention.

[0030] Figure 12A , 12B 12C and 12D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the fourth embodiment of the projection lens according to the present invention.

[0031] Figure 13 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end according to the fifth embodiment of the projection lens of the present invention.

[0032] Figure 14A , 14B 14C and 14D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the fifth embodiment of the projection lens according to the present invention.

[0033] Figure 15A , 15B 15C and 15D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the fifth embodiment of the projection lens according to the present invention.

[0034] Figure 16 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the sixth embodiment of the projection lens according to the present invention.

[0035] Figure 17A , 17B 17C and 17D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the sixth embodiment of the projection lens according to the present invention.

[0036] Figure 18A , 18B 18C and 18D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the sixth embodiment of the projection lens according to the present invention.

[0037] Figure 19 This is a schematic diagram of the lens configuration and optical path of a seventh embodiment of a projection lens according to the present invention.

[0038] Figure 20A , 20B 20C and 20D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams of the seventh embodiment of the projection lens according to the present invention.

[0039] Figure 21 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the projection lens according to the eighth embodiment of the present invention.

[0040] Figure 22A , 22B 22C and 22D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the eighth embodiment of the projection lens according to the present invention.

[0041] Figure 23A , 23B 23C and 23D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the eighth embodiment of the projection lens according to the present invention.

[0042] Figure 24 This is a schematic diagram of the lens configuration and optical path at the wide-angle end and telephoto end of the projection lens according to the ninth embodiment of the present invention.

[0043] Figure 25A , 25B 25C and 25D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the wide-angle end of the ninth embodiment of the projection lens according to the present invention.

[0044] Figure 26A , 26B26C and 26D are field curvature diagrams, distortion diagrams, modulation conversion function diagrams, and defocus modulation conversion function diagrams at the telescope distance of the ninth embodiment of the projection lens according to the present invention. Detailed Implementation

[0045] This invention provides a projection lens, comprising: a first lens group having negative refractive power; a second lens group having positive refractive power; a third lens group having positive refractive power; a fourth lens group having refractive power; a fifth lens group having refractive power; and a sixth lens group having positive refractive power; wherein the first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group are arranged sequentially along the optical axis from the projection side to the image source side; wherein the first lens group includes a 1-1 lens and a 1-2 lens, the 1-1 lens being a meniscus lens and the 1-2 lens being a biconcave lens; wherein the fifth lens group includes a cemented lens, which helps to correct aberrations and improve resolution; wherein the sixth lens group includes a 6-1 lens, the 6-1 lens having positive refractive power and including a concave surface or a flat surface facing the projection side, which helps to eliminate ghosting. This embodiment satisfies the features of this embodiment and does not require other conditional features to achieve the basic operation of the optical system of this invention.

[0046] Please refer to Tables 1, 2, 4, 5, 7, 8, 10, 11, 13, 14, 16, 17, 19, 20, 22, 23, 25, and 26 below. Tables 1, 4, 7, 10, 13, 16, 19, 22, and 25 are the relevant parameter tables for each lens in the first to ninth embodiments of the projection lens according to the present invention. Tables 2, 5, 8, 11, 14, 17, 20, 23, and 26 are the relevant parameter tables for the aspherical surface of the aspherical lens in Tables 1, 4, 7, 10, 13, 16, 19, 22, and 25, respectively.

[0047] Please also refer to Figure 1 , 47, 10, 13, 16, 19, 21, 24, wherein the first lens group LG11, LG21, LG31, LG41, LG51, LG61, LG71, LG81, LG91 have negative refractive power and respectively include 1-1 lenses 1L11, 2L11, 3L11, 4L11, 5L11, 6L11, 7L11, 8L11, 9L11 and 1-2 lenses 1L12, 2L12, 3L12, 4L12, 5L12, 6L12, 7L12, 8L12, 9L12, and the second lens group LG12, LG22, LG32, LG42, LG52, LG62, LG72, LG82, LG92 have negative refractive power. The first group of lenses has positive refractive power and includes lenses 1L21, 2L21, 3L21, 4L21, 5L21, 6L21, 7L21, 8L21, and 9L21 (2-1 lenses). The second group of lenses LG13, LG23, LG33, LG43, LG53, LG63, LG73, LG83, and LG93 have positive refractive power and include lenses 1L31, 2L31, 3L31, 4L31, 5L31, 6L31, 7L31, 8L31, and 9L31 (3-1 lenses). The third group of lenses LG14, LG24, LG34, LG44, LG54, LG64, LG74, LG84, and LG94 have refractive power and include lenses 4-2... Lenses 1L42, 2L42, 3L42, 4L42, 5L42, 6L42, 7L42, 8L42, 9L42 and 4-1 lenses 1L41, 2L41, 3L41, 4L41, 5L41, 6L41, 7L41, 8L41, 9L41, and the fifth lens group LG15, LG25, LG35, LG45, LG55, LG65, LG75, LG85, LG95 have refractive power and respectively include cemented lenses 1LCL, 2LCL, 3LCL, 4LCL, 5LCL, 6LCL, 7LCL, 8LCL, 9LCL and 5-1 lenses 1L51, 2L51, 3L51, 4L51, 5L5 1. Lenses 6L51, 7L51, 8L51, 9L51 and 5-2 lenses 1L52, 2L52, 3L52, 4L52, 5L52, 6L52, 7L52, 8L52, 9L52, and 5-3 lenses 1L53, 2L53, 3L53, 4L53, 5L53, 6L53, 7L53, 8L53, 9L53, and the sixth lens group LG16, LG26, LG36, LG46, LG56, LG66, LG76, LG86, LG96 have positive refractive power, and include 6-1 lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L61, 9L61.

[0048] Lenses 1-1, 1L11, 2L11, 3L11, 4L11, 5L11, 6L11, 7L11, 8L11, and 9L11 are meniscus lenses with negative refractive power. Their projection sides S11, S21, S33, S43, S53, S63, S73, S83, and S93 are convex, while their image source sides S12, S22, S34, S44, S54, S64, S74, S84, and S94 are concave. Lenses 1-2, 1L12, 2L12, 3L12, 4L12, 5L12, 6L12, 7L12, 8L12, and 9L12, have negative refractive power. Their projection sides S13, S23, S37, S45, S55, S67, S75, S87, and S95, as well as their image source sides S14, S24, S38, S46, S56, S68, S76, S88, and S96, are all concave and spherical surfaces.

[0049] Lenses 1L21, 2L21, 3L21, 4L21, 5L21, 6L21, 7L21, 8L21, and 9L21 have positive refractive power, and their image source sides S16, S26, S310, S48, S58, S610, S78, S810, and S98 are convex and spherical surfaces.

[0050] Lenses 1L31, 2L31, 3L31, 4L31, 5L31, 6L31, 7L31, 8L31, and 9L31 of 3-1 have positive refractive power. Their projection sides S17, S27, S313, S411, S511, S611, S79, S813, and S911 are convex and spherical surfaces, while the image source sides S18, S28, S314, S412, S512, S612, S710, S814, and S912 are spherical surfaces.

[0051] Lenses 1L42, 2L42, 3L42, 4L42, 5L42, 6L42, 7L42, 8L42, and 9L42 of the 4-2 series have negative refractive power. Their projection sides S110, S210, S316, S414, S514, S614, S712, S816, and S914, as well as the image source sides S111, S211, S317, S415, S515, S615, S713, S817, and S915, are all spherical surfaces. Lenses 1L41, 2L41, 3L41, 4L41, 5L41, 6L41, 7L41, 8L41, and 9L41 are biconvex lenses with positive refractive power. The projection sides S112, S211, S318, S416, S516, S615, S713, S818, and S916, as well as the image source sides S113, S212, S319, S417, S517, S616, S714, S819, and S917, are all spherical surfaces.

[0052] Cemented lenses 1LCL, 2LCL, 3LCL, 4LCL, 5LCL, 6LCL, 7LCL, 8LCL, and 9LCL have negative refractive power. Lenses 1L51, 2L51, 3L51, 4L51, 5L51, 6L51, 7L51, 8L51, and 9L51 are biconcave lenses with negative refractive power. Their projection sides S114, S213, S321, S419, S519, S617, S715, S820, and S918, as well as their image source sides S115, S214, S322, S420, S520, S618, S716, S821, and S919, are all spherical surfaces. Lenses 1L52, 2L52, 3L52, 4L52, 5L52, 6L52, 7L52, 8L52, and 9L52 are biconvex lenses with positive refractive power. Their projection sides S115, S214, S322, S420, S520, S618, S716, S821, and S919, as well as the image source sides S116, S215, S323, S421, S521, S619, S717, S822, and S920, are all spherical surfaces. Lenses 1L53, 2L53, 3L53, 4L53, 5L53, 6L53, 7L53, 8L53, and 9L53 of the 5-3 series have positive refractive power. Their projection sides S117, S216, S324, S422, S522, S620, S718, S823, and S921, as well as the image source sides S118, S217, S325, S423, S523, S621, S719, S824, and S922, are all convex. The aforementioned 5-1 lenses 1L51, 2L51, 3L51, 4L51, 5L51, 6L51, 7L51, 8L51, and 9L51 are respectively bonded to 5-2 lenses 1L52, 2L52, 3L52, 4L52, 5L52, 6L52, 7L52, 8L52, and 9L52. The bonding described in the instruction manual refers to tight adhesion or the absence of air gaps between the two to form a bonded lens.

[0053] Lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L61, and 9L61 of the 6-1 series have positive refractive power, and their image source sides S120, S219, S327, S425, S525, S623, S721, S826, and S924 are convex surfaces.

[0054] Through the above design, projection lenses 1, 2, 3, 4, 5, 6, 7, 8, and 9 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberrations. In addition, in a preferred embodiment, projection lenses 1, 2, 3, 4, 5, 6, 7, 8, and 9 can achieve the preferred embodiment by satisfying at least one of the following conditions (1) to (7):

[0055] 6.02 <TTL / f<23.34; (1)

[0056] 3.84 <TTL / BFL<5.85; (2)

[0057] -5.28 <fCL / f<-1.17; (3)

[0058] 1<(R 6-11 +R 6-12 ) / (R 6-11 -R 6-12 (4) < 1.5;

[0059] -1.51 <R 6-12 / BFL<-0.88; (5)

[0060] Vd6-1<21; (6)

[0061] -1.06 <fCL / f LG6 <-0.48 (7)

[0062] Wherein, TTL refers to the distance between the projection sides S11, S21, S31, S41, S51, S61, S71, S81, S91 of the lenses 1L11, 2L11, 3L13, 4L13, 5L13, 6L13, 7L13, 8L13, and 9L13 closest to the projection side and an image source IS1, IS2, IS3, IS4, IS5, IS6, IS7, IS8, IS9 on the optical axes OA1, OA2, OA3, OA4, OA5, OA6, OA7, OA8, OA9 in the first to ninth embodiments, and BFL refers to the distance between the 6-1 lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L13 and 9L13 closest to the projection side on the optical axes OA1, OA2, OA3, OA4, OA5, OA6, OA7, OA8, OA9 in the first to ninth embodiments. The distances from the image source sides S120, S219, S327, S425, S525, S623, S721, S826, S924 to the image sources IS1, IS2, IS3, IS4, IS5, IS6, IS7, IS8, IS9 on the optical axes OA1, OA2, OA3, OA4, OA5, OA6, OA7, OA8, OA9, f is the effective focal length of projection lenses 1, 2, 3, 4, 5, 6, 7, 8, 9 in the first to ninth embodiments, fCL is the effective focal length of cemented lenses 1LCL, 2LCL, 3LCL, 4LCL, 5LCL, 6LCL, 7LCL, 8LCL, 9LCL in the first to ninth embodiments, R 6-11For the first to ninth embodiments, the radii of curvature of the projection side surfaces S119, S218, S326, S424, S524, S622, S720, S825, S923 of the 6-1 lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L61, 9L61, R 6-12 For the first to ninth embodiments, the radii of curvature of the image source side surfaces S120, S219, S327, S425, S525, S623, S721, S826, S924 of the 6-1 lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L61, 9L61, Vd6-1 is the Abbe number of the 6-1 lenses 1L61, 2L61, 3L61, 4L61, 5L61, 6L61, 7L61, 8L61, 9L61 in the first to ninth embodiments, f LG6 For the first to ninth embodiments, the effective focal lengths of the sixth lens groups LG16, LG26, LG36, LG46, LG56, LG76, LG86, LG96.

[0063] When the condition (1): 6.02 < TTL / f < 23.34 is satisfied, it can ensure that the projection lens has a better lens size and sufficient back focal length space for reserving additional required components; when the condition (2): 3.84 < TTL / BFL < 5.85 is satisfied, it can ensure that the projection lens has a better lens size and sufficient back focal length space for reserving additional required components; when the condition (3): -5.28 < fCL / f < -1.17 is satisfied, it helps to correct the aberration of the projection lens, can effectively reduce chromatic aberration, and greatly improve the resolution quality; when the condition (4): 1 < (R 6-11 +R 6-12 ) / (R 6-11 -R 6-12 ) < 1.5 is satisfied, it can reduce the ghosting caused by internal reflection between the projection lens and the light source; when the condition (5): -1.51 < R 6-12 / BFL < -0.88 is satisfied, it can achieve a better balance between a longer back focal length and optical performance; when the condition (6): Vd6-1 < 21 is satisfied, in cooperation with the materials of the foregoing lens groups, it can effectively correct the chromatic aberration of the three colors of red, green, and blue in the lens; when the condition (7): -1.06 < fCL / f LG6 < -0.48 is satisfied, it can effectively correct the lens aberration and improve the image quality.

[0064] Now, a first embodiment of the projection lens of the present invention will be described in detail. Please refer to Figure 1The projection lens 1, along the optical axis OA1 from the projection side to the image source side, sequentially includes a first lens group LG11, a second lens group LG12, a third lens group LG13, an aperture ST1, a fourth lens group LG14, a fifth lens group LG15, a sixth lens group LG16, a flat glass PG1, a prism P1, and a protective glass CG1. The first lens group LG11, along the optical axis OA1 from the projection side to the image source side, sequentially includes a 1-1 lens 1L11 and a 1-2 lens 1L12. The second lens group LG12 includes a 2-1 lens 1L21. The third lens group LG13 includes a 3-1 lens 1L31. The fourth lens group LG14, along the optical axis OA1 from the projection side to the image source side, sequentially includes a 4-2 lens 1L42 and a 4-1 lens 1L41. The fifth lens group LG15, along the optical axis OA1 from the projection side to the image source side, includes a cemented lens 1LCL and a 5-3 lens 1L53 in sequence. The cemented lens 1LCL, from the projection side to the image source side, includes a 5-1 lens 1L51 and a 5-2 lens 1L52 in sequence. The sixth lens group LG16 includes a 6-1 lens 1L61. During projection, light rays from an image source IS1 are ultimately projected onto the projection side.

[0065] Projection lens 1 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 1 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 1 As shown in the lower half, the first lens group LG11 is fixed; the second lens group LG12, the third lens group LG13, the fourth lens group LG14, and the fifth lens group LG15 move along the optical axis OA1 towards the projection side, while the sixth lens group LG16 remains fixed, thus changing the spacing between the lens groups. Additionally, the aperture ST1 can move following the third lens group LG13 and the fourth lens group LG14, or move independently. When the aperture moves independently, the wide-angle end and the telephoto end can have the same aperture value without changing the aperture value, by controlling the position of the aperture. The apertures in embodiments 2 to 9 below are the same as those described in this embodiment, and therefore will not be repeated. The projection lens 1 of the first embodiment starts from the wide-angle end (e.g., Figure 1 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 1When shown in the lower half), its zoom ratio is approximately 1.30x (22.2mm / 17.08mm≈1.30). The first lens group LG11 can move along the optical axis OA1 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: lens 1-1 has aspherical surfaces on both its projection side S11 and image source side S12; lens 2-1 1L21 is a plano-convex lens with a planar projection side S15; lens 3-1 1L31 is a biconvex lens with a convex image source side S18; the fourth lens group LG14 has positive refractive power, lens 4-2 1L42 is a meniscus lens with a convex projection side S110 and a concave image source side S111; the fifth lens group LG15 has negative refractive power, and lens 5-3 1L53 has a convex projection side S117 and an image source side S111... 18 are all aspherical surfaces; 6-1 lens 1L61 is a meniscus lens, its projection side S119 is concave, and the projection side S119 and the image source side S120 are spherical surfaces; the projection sides S121, S123, S125 of the flat glass PG1, prism P1, and protective glass CG1, and the image source sides S122, S124, S126 are all planar; by utilizing the above lens group, aperture ST1, and the design that satisfies at least one of conditions (1) to (7), the projection lens 1 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 1 is as follows Figure 1 Table of relevant parameters for each lens when the projection lens 1 is at the wide-angle end (w) and the telescope end (t).

[0066] Table 1

[0067]

[0068]

[0069] The aspherical surface concavity z of the aspherical lens in Table 1 is obtained by the following formula:

[0070] z = ch 2 / {1+[1-(k+1)c 2 h 2 ] 1 / 2}+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16

[0071] in:

[0072] c: curvature;

[0073] h: The perpendicular distance from any point on the lens surface to the optical axis;

[0074] k: Conic constant;

[0075] A~G: Aspherical coefficients.

[0076] Table 2 is a table of relevant parameters for the aspherical surface of the aspherical lens in Table 1.

[0077] Table 2

[0078]

[0079]

[0080] Table 3 shows the relevant parameter values ​​of the projection lens 1 in the first embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 3, the projection lens 1 in the first embodiment can meet the requirements of conditions (1) to (7).

[0081] Table 3

[0082]

[0083] Furthermore, the optical performance of the projection lens 1 in the first embodiment also meets the requirements. Figure 2A It can be seen that the field curvature of the projection lens 1 in the first embodiment is between -0.04mm and 0.08mm at the wide-angle end. Figure 2B It can be seen that the distortion of the projection lens 1 in the first embodiment is between -0.8% and 0% at the wide-angle end. Figure 2C It can be seen that the modulation conversion function value of the projection lens 1 in the first embodiment is between 0.58 and 1.0 at the wide-angle end. Figure 2D It can be seen that, in the first embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 1 is between 0.0 and 0.80. Figure 3A It can be seen that the field curvature of the projection lens 1 in the first embodiment is between -0.12mm and 0.08mm at the telescope. Figure 3B It can be seen that the distortion of the projection lens 1 in the first embodiment is between 0% and 0.8% at the telescope. Figure 3C It can be seen that the modulation conversion function value of the projection lens 1 in the first embodiment is between 0.55 and 1.0. Figure 3DAs can be seen, at the telescope distance, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value is between 0.0 and 0.76. Clearly, the field curvature and distortion of the projection lens 1 in the first embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0084] The second embodiment of the projection lens of the present invention will now be described in detail. Please refer to... Figure 4 The projection lens 2, along the optical axis OA2 from the projection side to the image source side, sequentially includes a first lens group LG21, a second lens group LG22, a third lens group LG23, an aperture ST2, a fourth lens group LG24, a fifth lens group LG25, a sixth lens group LG26, a flat glass PG2, a prism P2, and a protective glass CG2. The first lens group LG21, along the optical axis OA2 from the projection side to the image source side, sequentially includes a 1-1 lens 2L11 and a 1-2 lens 2L12. The second lens group LG22 includes a 2-1 lens 2L21. The third lens group LG23 includes a 3-1 lens 2L31. The fourth lens group LG24, along the optical axis OA2 from the projection side to the image source side, sequentially includes a 4-2 lens 2L42 and a 4-1 lens 2L41. The fifth lens group LG25, along the optical axis OA2 from the projection side to the image source side, sequentially includes a cemented lens 2LCL and a 5-3 lens 2L53. The cemented lens 2LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 2L51 and a 5-2 lens 2L52. The sixth lens group LG26 includes a 6-1 lens 2L61. During projection, light rays from an image source IS2 are ultimately projected onto the projection side.

[0085] Projection lens 2 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 4 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 4 As shown in the lower half, the first lens group LG21 moves along the optical axis OA2 towards the image source side; the second lens group LG22, the third lens group LG23, the fourth lens group LG24, and the fifth lens group LG25 move along the optical axis OA2 towards the projection side, while the sixth lens group LG26 remains fixed, thus changing the spacing between the lens groups. The projection lens 2 of the second embodiment starts from the wide-angle end (e.g., ... Figure 4 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 4When shown in the lower half), its zoom ratio is approximately 1.30x (22.1mm / 17.00mm = 1.3). The first lens group LG21 can move along the optical axis OA2 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: lens 1-1 has aspherical surfaces on both its projection side S21 and image source side S22; lens 2-1 2L21 is a biconvex lens, with its projection side S25 being convex and spherical; lens 3-1 2L31 is a meniscus lens, with its image source side S28 being concave; the fourth lens group LG24 has negative refractive power, and lens 4-2 2L42 has concave surfaces on both its projection side S210 and image source side S211, and lens 4-2 2L42 is cemented with lens 4-1 2L41; the fifth lens group LG25 has positive refractive power, and lens 5-3 2L53 has a projection side S210 and image source side S211 being concave; Side S216 and image source side S217 are both aspherical surfaces; 6-1 lens 2L61 is a plano-convex lens, its projection side S218 is a plane, and its image source side S219 is a spherical surface; the projection sides S220, S222, S224 of the flat glass PG2, prism P2, and protective glass CG2, and the image source sides S221, S223, and S225 are all planes; by utilizing the above lens group, aperture ST2, and the design that satisfies at least one of conditions (1) to (7), the projection lens 2 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 4 shows... Figure 4 Table of relevant parameters for each lens when the projection lens 2 is at the wide-angle end (w) and the telescope end (t).

[0086] Table 4

[0087]

[0088]

[0089] The definition of the aspherical surface concavity z of the aspherical lens in Table 4 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 5 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 4, where k is the conic constant and A to G are the aspherical coefficients.

[0090] Table 5

[0091]

[0092] Table 6 shows the relevant parameter values ​​of the projection lens 2 in the second embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 6, the projection lens 2 in the second embodiment can meet the requirements of conditions (1) to (7).

[0093] Table 6

[0094]

[0095] Furthermore, the optical performance of the projection lens 2 in the second embodiment also meets the requirements. Figure 5A It can be seen that the field curvature of the projection lens 2 in the second embodiment is between -0.04mm and 0.08mm at the wide-angle end. Figure 5B It can be seen that the distortion of the projection lens 2 in the second embodiment is between -0.8% and 0% at the wide-angle end. Figure 5C It can be seen that the modulation conversion function value of the projection lens 2 in the second embodiment is between 0.65 and 1.0 at the wide-angle end. Figure 5D It can be seen that, in the second embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 2 is between 0.0 and 0.80. Figure 6A It can be seen that the field curvature of the projection lens 2 in the second embodiment is between -0.08mm and 0.08mm at the telescope. Figure 6B It can be seen that the distortion of the projection lens 2 in the second embodiment is between -0.8% and 0% at the telescope. Figure 6C It can be seen that the modulation conversion function value of the projection lens 2 in the second embodiment is between 0.47 and 1.0. Figure 6D As can be seen, in the second embodiment, the projection lens 2 at the telescope has a modulation conversion function value between 0.04 and 0.8 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 2 in the second embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0096] The third embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 7The projection lens 3, along the optical axis OA3 from the projection side to the image source side, sequentially includes a first lens group LG31, a second lens group LG32, a third lens group LG33, an aperture ST3, a fourth lens group LG34, a fifth lens group LG35, a sixth lens group LG36, a flat glass PG3, a prism P3, and a protective glass CG3. The first lens group LG31, along the optical axis OA3 from the projection side to the image source side, sequentially includes a 1-3 lens 3L13, a 1-1 lens 3L11, a 1-4 lens 3L14, and a 1-2 lens 3L12. The second lens group LG32, along the optical axis OA3 from the projection side to the image source side, sequentially includes a 2-1 lens 3L21 and a 2-2 lens 3L22. The third lens group LG33 includes a 3-1 lens 3L31. The fourth lens group LG34, along the optical axis OA3 from the projection side to the image source side, sequentially includes a 4-2 lens 3L42, a 4-1 lens 3L41, and a 4-3 lens 3L43. The fifth lens group LG35, along the optical axis OA3 from the projection side to the image source side, sequentially includes a cemented lens 3LCL and a 5-3 lens 3L53. The cemented lens 3LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 3L51 and a 5-2 lens 3L52. The sixth lens group LG36 includes a 6-1 lens 3L61. During projection, light from an image source IS3 is ultimately projected onto the projection side. The projection lens 3 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 7 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 7 As shown in the lower half, the first lens group LG31 is fixed, the second lens group LG32, the third lens group LG33, the fourth lens group LG34, and the fifth lens group LG35 move along the optical axis OA3 towards the projection side, and the sixth lens group LG36 is fixed, thus changing the spacing between the lens groups. The projection lens 3 of the third embodiment starts from the wide-angle end (e.g., ... Figure 7 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 7When shown in the lower half), its zoom ratio is approximately 1.34x (23.3mm / 17.37mm≈1.34). The first lens group LG31 can move along the optical axis OA3 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: lens 3L13 of 1-3 is a meniscus lens with positive refractive power, its projection side S31 is convex, and its image source side S32 is concave, and both the projection side S31 and the image source side S32 are spherical surfaces; lens 3L11 of 1-1 has both its projection side S33 and its image source side S34 as spherical surfaces; lens 3L14 of 1-4 is a meniscus lens with negative refractive power, its projection side S35 is convex, and its image source side S36 is concave, and both the projection side S35 and the image source side S36 are spherical surfaces. All surfaces S36 are spherical; Lens 3L21 (2-1) is a meniscus lens, its projection side S39 is concave and spherical; Lens 3L22 (2-2) has positive refractive power, its projection side S311 is convex, and its image source side S312 is convex, both projection side S311 and image source side S312 are spherical surfaces; Lens 3L31 (3-1) is a biconvex lens, its image source side S314 is convex; The fourth lens group LG34 has positive refractive power; Lens 3L42 (4-2) is a meniscus lens, its projection side S311 is convex. Lens 6 is convex, image source side S317 is concave, lens 4-3 3L43 is a meniscus lens with negative refractive power, its projection side S319 is concave, and image source side S320 is convex. Both projection side S319 and image source side S320 are spherical surfaces. Lens 4-1 3L41 is cemented with lens 4-3 3L43; the fifth lens group LG35 has negative refractive power, and both projection side S324 and image source side S325 of lens 5-3 3L53 are aspherical surfaces; lens 6-1 3L61 is a meniscus lens. Its projection side S326 is concave, and both the projection side S326 and the image source side S327 are spherical surfaces; the projection sides S328, S330, and S332 of the flat glass PG3, prism P3, and protective glass CG3, and the image source sides S329, S331, and S333 are all planar; by utilizing the above lens group, aperture ST3, and the design that satisfies at least one of conditions (1) to (7), the projection lens 3 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 7 shows... Figure 7 Table of relevant parameters for each lens when the projection lens 3 is at the wide-angle end (w) and the telescope end (t).

[0097] Table 7

[0098]

[0099] The definition of the aspherical surface concavity z of the aspherical lens in Table 7 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 8 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 7, where k is the conic constant and A to G are the aspherical coefficients.

[0100] Table 8

[0101]

[0102] Table 9 shows the relevant parameter values ​​of the projection lens 3 in the third embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 9, the projection lens 3 in the third embodiment can meet the requirements of conditions (1) to (7).

[0103] Table 9

[0104]

[0105] Furthermore, the optical performance of the projection lens 3 in the third embodiment also meets the requirements. Figure 8A It can be seen that the field curvature of the projection lens 3 in the third embodiment is between -0.04mm and 0.08mm at the wide-angle end. Figure 8B It can be seen that the distortion of the projection lens 3 in the third embodiment is between -2.0% and 0% at the wide-angle end. Figure 8C It can be seen that the modulation conversion function value of the projection lens 3 in the third embodiment is between 0.63 and 1.0 at the wide-angle end. Figure 8D It can be seen that, in the third embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 3 is between 0.0 and 0.84. Figure 9A It can be seen that the field curvature of the projection lens 3 in the third embodiment is between -0.04mm and 0.08mm at the telescope. Figure 9B It can be seen that the distortion of the projection lens 3 in the third embodiment is between -2.0% and 0% at the telescope. Figure 9C It can be seen that the modulation conversion function value of the projection lens 3 in the third embodiment is between 0.51 and 1.0. Figure 9D As can be seen, in the third embodiment, the projection lens 3 at the telescope has a modulation conversion function value between 0.01 and 0.8 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 3 in the third embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0106] The fourth embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 10The projection lens 4, along the optical axis OA4 from the projection side to the image source side, sequentially includes a first lens group LG41, a second lens group LG42, a third lens group LG43, an aperture ST4, a fourth lens group LG44, a fifth lens group LG45, a sixth lens group LG46, a flat glass PG4, a prism P4, and a protective glass CG4. The first lens group LG41, along the optical axis OA4 from the projection side to the image source side, sequentially includes a 1-3 lens 4L13, a 1-1 lens 4L11, and a 1-2 lens 4L12. The second lens group LG42, along the optical axis OA4 from the projection side to the image source side, sequentially includes a 2-1 lens 4L21 and a 2-2 lens 4L22. The third lens group LG43 includes a 3-1 lens 4L31. The fourth lens group LG44, along the optical axis OA4 from the projection side to the image source side, sequentially includes a 4-2 lens 4L42, a 4-1 lens 4L41, and a 4-3 lens 4L43. The fifth lens group LG45, along the optical axis OA4 from the projection side to the image source side, sequentially includes a cemented lens 4LCL and a 5-3 lens 4L53. The cemented lens 4LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 4L51 and a 5-2 lens 4L52. The sixth lens group LG46 includes a 6-1 lens 4L61. During projection, light from an image source IS4 is ultimately projected onto the projection side. The projection lens 4 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 10 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 10 As shown in the lower half, the first lens group LG41 is fixed, the second lens group LG42, the third lens group LG43, the fourth lens group LG44, and the fifth lens group LG45 move along the optical axis OA4 towards the projection side, and the sixth lens group LG46 is fixed, thus changing the spacing between the lens groups. In the fourth embodiment, the projection lens 4 starts from the wide-angle end (e.g., ...). Figure 10 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 10When shown in the lower half), its zoom ratio is approximately 1.60x (32.5mm / 20.3mm≈1.60). The first lens group LG41 can move along the optical axis OA4 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: 1-3 lens 4L13 is a meniscus lens with positive refractive power, its projection side S41 is convex, its image source side S42 is concave, and both the projection side S41 and the image source side S42 are spherical surfaces; 1-1 lens 4L11 has both its projection side S43 and its image source side S44 as spherical surfaces; 2-1 lens 4L21 is a meniscus lens, its projection side S47 is concave and is a spherical surface; 2-2 lens Lens 4L22 has positive refractive power; its projection side S49 is convex, and its image source side S410 is convex. Both projection side S49 and image source side S410 are spherical surfaces. Lens 4L31 (3-1) is a biconvex lens; its image source side S412 is convex. The fourth lens group LG44 has positive refractive power. Lens 4L42 (4-2) has a concave projection side S414 and a concave image source side S415. Lens 4L43 (4-3) is a meniscus lens with negative refractive power. Its projection side S417 is concave, and its image source side S418 is convex. Both projection side S417 and image source side S418 are spherical surfaces. Lens 4L41 (4-1) and lens 4L43 (4-3) are cemented together. The fifth lens group LG45 has negative refractive power. The projection side S422 and image source side S423 of lens 4L53 (5-3) are both aspherical surfaces. Lens 4L61 (6-1) is a meniscus lens. Its projection side S424 is concave, and its projection side S42... 4. Both the projection surfaces of the image source and the image source side S425 are spherical surfaces; the projection surfaces S426, S428, and S430 of the flat glass PG4, prism P4, and protective glass CG4, and the image source sides S427, S429, and S431 are all planar surfaces; by utilizing the above lens group, aperture ST4, and the design that satisfies at least one of conditions (1) to (7), the projection lens 4 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 10 shows... Figure 10 Table of relevant parameters for each lens when the projection lens 4 is at the wide-angle end (w) and the telescope end (t).

[0107] Table 10

[0108]

[0109]

[0110] The definition of the aspherical surface concavity z of the aspherical lens in Table 10 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 11 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 10, where k is the conic constant and A to G are the aspherical coefficients.

[0111] Table 11

[0112]

[0113] Table 12 shows the relevant parameter values ​​of the projection lens 4 in the fourth embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 12, the projection lens 4 in the fourth embodiment can meet the requirements of conditions (1) to (7).

[0114] Table 12

[0115]

[0116] Furthermore, the optical performance of the projection lens 4 in the fourth embodiment also meets the requirements. Figure 11A It can be seen that the field curvature of the projection lens 4 in the fourth embodiment is between -0.08mm and 0.08mm at the wide-angle end. Figure 11B It can be seen that the distortion of the projection lens 4 in the fourth embodiment is between -2.0% and 0% at the wide-angle end. Figure 11C It can be seen that the modulation conversion function value of the projection lens 4 in the fourth embodiment is between 0.59 and 1.0 at the wide-angle end. Figure 11D It can be seen that, in the fourth embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 4 is between 0.0 and 0.8. Figure 12A It can be seen that the field curvature of the projection lens 4 in the fourth embodiment is between -0.12mm and 0.12mm at the telescope. Figure 12B It can be seen that the distortion of the projection lens 4 in the fourth embodiment is between -1.2% and 0% at the telescope. Figure 12C It can be seen that the modulation conversion function value of the projection lens 4 in the fourth embodiment is between 0.49 and 1.0. Figure 12D As can be seen, in the fourth embodiment, the projection lens 4 at the telescope has a modulation conversion function value between 0 and 0.7 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 4 in the fourth embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0117] The fifth embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 13The projection lens 5, along the optical axis OA5 from the projection side to the image source side, sequentially includes a first lens group LG51, a second lens group LG52, a third lens group LG53, an aperture ST5, a fourth lens group LG54, a fifth lens group LG55, a sixth lens group LG56, a flat glass PG5, a prism P5, and a protective glass CG5. The first lens group LG51, along the optical axis OA5 from the projection side to the image source side, sequentially includes a 1-3 lens 5L13, a 1-1 lens 5L11, and a 1-2 lens 5L12. The second lens group LG52, along the optical axis OA5 from the projection side to the image source side, sequentially includes a 2-1 lens 5L21 and a 2-2 lens 5L22. The third lens group LG53 includes a 3-1 lens 5L31. The fourth lens group LG54, along the optical axis OA5 from the projection side to the image source side, sequentially includes a 4-2 lens 5L42, a 4-1 lens 5L41, and a 4-3 lens 5L43. The fifth lens group LG55, along the optical axis OA5 from the projection side to the image source side, sequentially includes a cemented lens 5LCL and a 5-3 lens 5L53. The cemented lens 5LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 5L51 and a 5-2 lens 5L52. The sixth lens group LG56 includes a 6-1 lens 5L61. During projection, light from an image source IS5 is ultimately projected onto the projection side. The projection lens 5 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 13 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 13 As shown in the lower half, the first lens group LG51 remains fixed; the second lens group LG52, the third lens group LG53, the fourth lens group LG54, and the fifth lens group LG55 move along the optical axis OA5 towards the projection side, while the sixth lens group LG56 remains fixed, thus changing the spacing between the lens groups. In the fifth embodiment, the projection lens 5 starts from the wide-angle end (e.g., ...). Figure 13 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 13When shown in the lower half), its zoom ratio is approximately 1.10x (12.5mm / 11.4mm≈1.10). The first lens group LG51 can move along the optical axis OA5 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: 1-3 lens 5L13 is a meniscus lens with negative refractive power, its projection side S51 is convex, its image source side S52 is concave, and both the projection side S51 and the image source side S52 are spherical surfaces; 1-1 lens 5L11 has both its projection side S53 and its image source side S54 aspherical surfaces; 2-1 lens 5L21 is a meniscus lens, its projection side S57 is concave and is a spherical surface; 2-2 lens 5 L22 has positive refractive power; its projection side S59 is convex, and its image source side S510 is convex. Both projection side S59 and image source side S510 are spherical surfaces. Lens 5L31 (3-1) is a biconvex lens; its image source side S512 is convex. The fourth lens group LG54 has negative refractive power; lens 5L42 (4-2) is a meniscus lens; its projection side S514 is concave, and its image source side S515 is convex. Lens 5L43 (4-3) is a meniscus lens with... Negative refractive power; its projection side S517 is concave, and its image source side S518 is convex. Both projection side S517 and image source side S518 are spherical surfaces. Lens 5L41 (4-1) and lens 5L43 (4-3) are cemented together. The fifth lens group LG55 has positive refractive power; both projection side S522 and image source side S523 of lens 5L53 (5-3) are aspherical surfaces. Lens 5L61 (6-1) is a meniscus lens; its projection side S524 is concave, and its projection side... S524 and the image source side S525 are both spherical surfaces; the projection sides S526, S528, and S530 of the flat glass PG5, prism P5, and protective glass CG5, and the image source sides S527, S529, and S531 are all planar; by utilizing the above lens group, aperture ST5, and design that satisfies at least one of conditions (1) to (7), the projection lens 5 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 13 shows... Figure 13 Table of relevant parameters for each lens when the projection lens 5 is at the wide-angle end (w) and the telescope end (t).

[0118] Table Thirteen

[0119]

[0120]

[0121] The definition of the aspherical surface concavity z of the aspherical lens in Table 13 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 14 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 13, where k is the conic constant and A to G are the aspherical coefficients.

[0122] Table 14

[0123]

[0124] Table 15 shows the relevant parameter values ​​of the projection lens 5 in the fifth embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 15, the projection lens 5 in the fifth embodiment can meet the requirements of conditions (1) to (7).

[0125] Table 15

[0126]

[0127] Furthermore, the optical performance of the projection lens 5 in the fifth embodiment also meets the requirements. Figure 14A It can be seen that the field curvature of the projection lens 5 in the fifth embodiment is between -0.04mm and 0.08mm at the wide-angle end. Figure 14B It can be seen that the distortion of the projection lens 5 in the fifth embodiment is between -2% and 0% at the wide-angle end. Figure 14C It can be seen that the modulation conversion function value of the projection lens 5 in the fifth embodiment is between 0.64 and 1.0 at the wide-angle end. Figure 14D It can be seen that, in the fifth embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 5 is between 0.01 and 0.81. Figure 15A It can be seen that the field curvature of the projection lens 5 in the fifth embodiment is between -0.04mm and 0.08mm at the telescope. Figure 15B It can be seen that the distortion of the projection lens 5 in the fifth embodiment at the telescope distance is between -1.2% and 0%. As shown in Figure 15C, the modulation transfer function value of the projection lens 5 in the fifth embodiment at the telescope distance is between 0.55 and 1.0. Figure 15D As can be seen, in the fifth embodiment, the projection lens 5 at the telescope has a modulation conversion function value between 0 and 0.89 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 5 in the fifth embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0128] The sixth embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 16The projection lens 6, along the optical axis OA6 from the projection side to the image source side, sequentially includes a first lens group LG61, a second lens group LG62, a third lens group LG63, an aperture ST6, a fourth lens group LG64, a fifth lens group LG65, a sixth lens group LG66, a flat glass PG6, a prism P6, and a protective glass CG6. The first lens group LG61, along the optical axis OA6 from the projection side to the image source side, sequentially includes a 1-3 lens 6L13, a 1-4 lens 6L14, a 1-1 lens 6L11, and a 1-2 lens 6L12. The second lens group LG62 includes a 2-1 lens 6L21. The third lens group LG63 includes a 3-1 lens 6L31. The fourth lens group LG64, along the optical axis OA6 from the projection side to the image source side, sequentially includes a 4-2 lens 6L42 and a 4-1 lens 6L41. The fifth lens group LG65, along the optical axis OA6 from the projection side to the image source side, sequentially includes a cemented lens 6LCL and a 5-3 lens 6L53. The cemented lens 6LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 6L51 and a 5-2 lens 6L52. The sixth lens group LG66 includes a 6-1 lens 6L61. During projection, light from an image source IS6 is ultimately projected onto the projection side. The projection lens 6 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 16 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 16 As shown in the lower half, the first lens group LG61 moves along the optical axis OA6 towards the image source side; the second lens group LG62, the third lens group LG63, the fourth lens group LG64, and the fifth lens group LG65 move along the optical axis OA6 towards the projection side, while the sixth lens group LG66 remains fixed, thus changing the spacing between the lens groups. The projection lens 6 of the sixth embodiment starts from the wide-angle end (e.g., ... Figure 16 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 16When shown in the lower half), its zoom ratio is approximately 1.09x (12.2mm / 11.2mm≈1.09). The first lens group LG61 can move along the optical axis OA6 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: lens 6L13 of 1-3 is a meniscus lens with negative refractive power, its projection side S61 is convex, and its image source side S62 is concave; both projection side S61 and image source side S62 are aspherical surfaces; lens 6L14 of 1-4 is a meniscus lens with positive refractive power, its projection side S63 is convex, and its image source side S64 is concave; both projection side S63 and image source side S64 are aspherical surfaces. Lens 6L11 (1-1) has spherical surfaces on both its projection side S65 and image source side S66; Lens 6L21 (2-1) is a biconvex lens with a convex projection side S69 and a spherical surface; Lens 6L31 (3-1) is a meniscus lens with a concave image source side S612; the fourth lens group LG64 has positive refractive power, and Lens 6L42 (4-2) is a meniscus lens with a convex projection side S614. The image source side S615 is concave, and the 4-2 lens 6L42 and the 4-1 lens 6L41 are cemented together; the fifth lens group LG65 has positive refractive power, the projection side S620 of the 5-3 lens 6L53 is an aspherical surface, and the image source side S621 is an aspherical surface; the 6-1 lens 6L61 is a plano-convex lens, its projection side S622 is a plane, and the image source side S623 is a spherical surface; the flat glass PG6 has a projection side S624 and an image source side S625 that are both planes; the prism P6 has a projection side S626 and an image source side S627 that are both planes; the protective glass CG6 has a projection side S628 and an image source side S629 that are both planes; by using the above lens group, the aperture ST6 and the design that satisfies at least one of the conditions (1) to (7), the projection lens 6 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 16 is Figure 16 Table of relevant parameters for each lens of the projection lens 6 when it is at the wide-angle end (w) and the telescope end (t).

[0129] Table 16

[0130]

[0131]

[0132] The definition of the aspherical surface concavity z of the aspherical lens in Table 16 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 17 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 16, where k is the conic constant and A to G are the aspherical coefficients.

[0133] Table 17

[0134]

[0135] Table 18 shows the relevant parameter values ​​of the projection lens 6 in the sixth embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 18, the projection lens 6 in the sixth embodiment can meet the requirements of conditions (1) to (7).

[0136] Table 18

[0137]

[0138] Furthermore, the optical performance of the projection lens 6 in the sixth embodiment also meets the requirements. Figure 17A It can be seen that the field curvature of the projection lens 6 in the sixth embodiment is between -0.08mm and 0.12mm at the wide-angle end. Figure 17B It can be seen that the distortion of the projection lens 6 in the sixth embodiment is between -1.2% and 0.4% at the wide-angle end. Figure 17C It can be seen that the modulation conversion function value of the projection lens 6 in the sixth embodiment is between 0.49 and 1.0 at the wide-angle end. Figure 17D It can be seen that, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 6 in the sixth embodiment is between 0.02 and 0.77. As shown in Figure 18A, at the telephoto end, the field curvature of the projection lens 6 in the sixth embodiment is between -0.08mm and 0.08mm. Figure 18B It can be seen that the distortion of the projection lens 6 in the sixth embodiment is between -1.2% and 0.2% at the telescope. Figure 18C It can be seen that the modulation conversion function value of the projection lens 6 in the sixth embodiment is between 0.54 and 1.0. Figure 18D As can be seen, the projection lens 6 of the sixth embodiment, at the telescope distance, has a modulation conversion function value between 0.04 and 0.85 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 6 of the sixth embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0139] The seventh embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 19The projection lens 7, along the optical axis OA7 from the projection side to the image source side, sequentially includes a first lens group LG71, a second lens group LG72, a third lens group LG73, an aperture ST7, a fourth lens group LG74, a fifth lens group LG75, a sixth lens group LG76, a flat glass PG7, a prism P7, and a protective glass CG7. The first lens group LG71, along the optical axis OA7 from the projection side to the image source side, sequentially includes a 1-3 lens 7L13, a 1-1 lens 7L11, and a 1-2 lens 7L12. The second lens group LG72 includes a 2-1 lens 7L21. The third lens group LG73 includes a 3-1 lens 7L31. The fourth lens group LG74, along the optical axis OA7 from the projection side to the image source side, sequentially includes a 4-2 lens 7L42 and a 4-1 lens 7L41. The fifth lens group LG75, along the optical axis OA7 from the projection side to the image source side, sequentially includes a cemented lens 7LCL and a 5-3 lens 7L53. The cemented lens 7LCL, from the projection side to the image source side, sequentially includes a 5-1 lens 7L51 and a 5-2 lens 7L52. The sixth lens group LG76 includes a 6-1 lens 7L61. During projection, light rays from an image source IS7 are ultimately projected onto the projection side.

[0140] Projection lens 7 is a fixed-focus lens. The first lens group LG71 can move along the optical axis OA7 for focusing. According to paragraphs 1 to 9 of the [Specific Implementation], wherein: 1-3 lens 7L13 is a meniscus lens with negative refractive power, its projection side S71 is convex, and its image source side S72 is concave; both the projection side S71 and the image source side S72 are aspherical surfaces; 1-1 lens 7L11 has both its projection side S73 and its image source side S74 aspherical surfaces; 2-1 lens 7L21 is a meniscus lens, its projection side S77 is concave and is a spherical surface; 3-1 lens 7L31 has its image source side S710 as convex; the fourth lens group LG74 has positive refractive power; 4-2 lens 7L42 is a meniscus lens, its projection side S712 is convex, and its image source side S713 is concave; 4-2 lens 7L42 and 4-1 lens... 7L41 cemented; the fifth lens group LG75 has negative refractive power, and the projection side S718 and image source side S719 of the 5-3 lens 7L53 are both aspherical surfaces; the 6-1 lens 7L61 is a meniscus lens, and its projection side S720 is concave, while the projection side S720 and image source side S721 are both spherical surfaces; the projection sides S722, S724, and S726 of the flat glass PG7, the prism P7, and the protective glass CG7, and the image source sides S723, S725, and S727 are all planar; by utilizing the above lens group, the aperture ST7, and the design that satisfies at least one of conditions (1) to (7), the projection lens 7 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 19 is Figure 19Table of relevant parameters for each lens in projection lens 7.

[0141] Table 19

[0142]

[0143]

[0144] The definition of the aspherical surface concavity z of the aspherical lens in Table 19 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 20 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 19, where k is the conic constant and A to G are the aspherical coefficients.

[0145] Table 20

[0146]

[0147] Table 21 shows the relevant parameter values ​​of the projection lens 7 in the seventh embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 21, the projection lens 7 in the seventh embodiment can meet the requirements of conditions (1) to (7).

[0148] Table 21

[0149]

[0150]

[0151] Furthermore, the optical performance of the projection lens 7 in the seventh embodiment also meets the requirements. Figure 20A It can be seen that the field curvature of the projection lens 7 in the seventh embodiment is between -0.8mm and 0.2mm. Figure 20B It can be seen that the distortion of the projection lens 7 in the seventh embodiment is between -0.8% and 0.8%. Figure 20C It can be seen that the modulation conversion function value of the projection lens 7 in the seventh embodiment is between 0.61 and 1.0. Figure 20D As can be seen, the modulation conversion function value of the projection lens 7 in the seventh embodiment is between 0.04 and 0.89 when the focus offset is between -0.05mm and 0.05mm. Clearly, the field curvature and distortion of the projection lens 7 in the seventh embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0152] The eighth embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 21The projection lens 8, along the optical axis OA8 from the projection side to the image source side, sequentially includes a first lens group LG81, a second lens group LG82, a third lens group LG83, an aperture ST8, a fourth lens group LG84, a fifth lens group LG85, a sixth lens group LG86, a prism P8, and a protective glass CG8. The first lens group LG81, along the optical axis OA8 from the projection side to the image source side, sequentially includes a 1-3 lens 8L13, a 1-1 lens 8L11, a 1-4 lens 8L14, and a 1-2 lens 8L12. The second lens group LG82, along the optical axis OA8 from the projection side to the image source side, sequentially includes a 2-1 lens 8L21 and a 2-2 lens 8L22. The third lens group LG83 includes a 3-1 lens 8L31. The fourth lens group LG84, along the optical axis OA8 from the projection side to the image source side, sequentially includes a 4-2 lens 8L42 and a 4-1 lens 8L41. The fifth lens group LG85, along the optical axis OA8 from the projection side to the image source side, includes a cemented lens 8LCL and a 5-3 lens 8L53 in sequence. The cemented lens 8LCL, from the projection side to the image source side, includes a 5-1 lens 8L51 and a 5-2 lens 8L52 in sequence. The sixth lens group LG86 includes a 6-1 lens 8L61. During projection, light rays from an image source IS8 are ultimately projected onto the projection side.

[0153] Projection lens 8 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 21 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 21 As shown in the lower half, the first lens group LG81 is fixed, the second lens group LG82, the third lens group LG83, the fourth lens group LG84, and the fifth lens group LG85 move along the optical axis OA8 towards the projection side, the sixth lens group LG86 is fixed, and the aperture ST8 moves along the optical axis OA8 towards the projection side, thus changing the spacing between the lens groups. The projection lens 8 of the eighth embodiment starts from the wide-angle end (e.g., ... Figure 21 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 21When the zoom ratio is approximately 1.74x (23.7mm / 13.6mm≈1.74), as shown in the lower half, the first lens group LG81 can move along the optical axis OA8 for focusing. According to paragraphs one through nine of the [Specific Implementation], wherein: 1-3 lens 8L13 is a meniscus lens with positive refractive power, its projection side S81 is convex, its image source side S82 is concave, and both projection side S81 and image source side S82 are spherical surfaces; 1-1 lens 8L11 has both projection side S83 and image source side S84 as spherical surfaces; 1-4 lens 8L14 is a meniscus lens with negative refractive power, its projection side S85 is convex, its image source side S86 is concave, and both projection side S85 and image source side S86 are spherical surfaces; 2-1 lens 8L21 is a meniscus lens, its projection side S89 is concave and is a spherical surface; 2-2 lens 8L22 has positive refractive power, its projection side S811 and image source side S812 are both convex and spherical surfaces; 3-1 lens 8L31 has its image source side... S814 is a convex surface; the fourth lens group LG84 has positive refractive power, and the projection side S816 and image source side S817 of the 4-2 lens 8L42 are both concave surfaces; the fifth lens group LG85 has positive refractive power, and the projection side S823 and image source side S824 of the 5-3 lens 8L53 are both aspherical surfaces; the 6-1 lens 8L61 is a meniscus lens, and its projection side S825 is concave, while the projection side S825 and image source side S826 are both spherical surfaces; the projection sides S827 and S829 of the prism P8 and the protective glass CG8 and the image source sides S828 and S830 are both planar surfaces; by utilizing the above lens group, aperture ST8, and the design that satisfies at least one of conditions (1) to (7), the projection lens 8 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 22 is Figure 21 Table of relevant parameters for each lens of the projection lens 8 when it is at the wide-angle end (w) and the telescope end (t).

[0154] Table 22

[0155]

[0156]

[0157] The definition of the aspherical surface concavity z of the aspherical lens in Table 22 is the same as the definition of the aspherical surface concavity z of the aspherical lens in Table 1 of the first embodiment, and will not be repeated here. Table 23 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 22, where k is the conic constant and A to G are the aspherical coefficients.

[0158] Table 23

[0159]

[0160] Table 24 shows the relevant parameter values ​​of the projection lens 8 in the eighth embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 24, the projection lens 8 in the eighth embodiment can meet the requirements of conditions (1) to (7).

[0161] Table 24

[0162]

[0163]

[0164] Furthermore, the optical performance of the projection lens 8 in the eighth embodiment also meets the requirements. Figure 22A It can be seen that the field curvature of the projection lens 8 in the eighth embodiment is between -0.04mm and 0.08mm at the wide-angle end. Figure 22B It can be seen that the distortion of the projection lens 8 in the eighth embodiment is between -2.0% and 0% at the wide-angle end. Figure 22C It can be seen that the modulation conversion function value of the projection lens 8 in the eighth embodiment is between 0.55 and 1.0 at the wide-angle end. Figure 22D It can be seen that, at the wide-angle end, when the focus offset of the projection lens 8 in the eighth embodiment is between -0.05mm and 0.05mm, its modulation conversion function value is between 0.02 and 0.8. Figure 23A It can be seen that the field curvature of the projection lens 8 in the eighth embodiment is between -0.12mm and 0.04mm at the telescope. Figure 23B It can be seen that the distortion of the projection lens 8 in the eighth embodiment is between -0.8% and 0% at the telescope. Figure 23C It can be seen that the modulation conversion function value of the projection lens 8 in the eighth embodiment is between 0.37 and 1.0. Figure 23D As can be seen, at the telescope distance, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value is between 0.02 and 0.69. Clearly, the field curvature and distortion of the projection lens 8 in the eighth embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0165] The ninth embodiment of the projection lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 24The projection lens 9, along the optical axis OA9 from the projection side to the image source side, sequentially includes a first lens group LG91, a second lens group LG92, a third lens group LG93, an aperture ST9, a fourth lens group LG94, a fifth lens group LG95, a sixth lens group LG96, a flat glass PG9, a prism P9, and a protective glass CG9. The first lens group LG91, along the optical axis OA9 from the projection side to the image source side, sequentially includes a 1-3 lens 9L13, a 1-1 lens 9L11, and a 1-2 lens 9L12. The second lens group LG92, along the optical axis OA9 from the projection side to the image source side, sequentially includes a 2-1 lens 9L21 and a 2-2 lens 9L22. The third lens group LG93 includes a 3-1 lens 9L31. The fourth lens group LG94, along the optical axis OA9 from the projection side to the image source side, sequentially includes a 4-2 lens 9L42 and a 4-1 lens 9L41. The fifth lens group LG95, along the optical axis OA9 from the projection side to the image source side, includes a cemented lens 9LCL and a 5-3 lens 9L53 in sequence. The cemented lens 9LCL, from the projection side to the image source side, includes a 5-1 lens 9L51 and a 5-2 lens 9L52 in sequence. The sixth lens group LG96 includes a 6-1 lens 9L61. During projection, light rays from an image source IS9 are ultimately projected onto the projection side.

[0166] Projection lens 9 is a zoom lens, extending from the wide-angle end (e.g., ...). Figure 24 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 24 As shown in the lower half, the first lens group LG91 is fixed, the second lens group LG92, the third lens group LG93, the fourth lens group LG94, and the fifth lens group LG95 move along the optical axis OA9 towards the projection side, the sixth lens group LG96 is fixed, and the aperture ST9 moves along the optical axis OA9 towards the projection side, thus changing the spacing between the lens groups. In the ninth embodiment, the projection lens 9 starts from the wide-angle end (e.g., ... Figure 24 (As shown in the upper part) Zoom to telephoto (e.g.) Figure 24When the zoom ratio is approximately 1.49x (33.3mm / 22.3mm≈1.49), as shown in the lower half, the first lens group LG91 can move along the optical axis OA9 for focusing. According to paragraphs one through nine of the [Specific Implementation], wherein: lens 9L13 (1-3) has positive refractive power, and both its projection side S91 and image source side S92 are convex and spherical surfaces; lens 9L11 (1-1) has both its projection side S93 and image source side S94 as spherical surfaces; lens 9L21 (2-1) is a meniscus lens, and its projection side S97 is concave and spherical; lens 9L22 (2-2) is a meniscus lens with positive refractive power, and its projection side S99 is convex, its image source side S910 is concave, and both its projection side S99 and image source side S910 are spherical surfaces; lens 9L31 (3-1) has its image source side S912 as convex; the fourth lens group LG94 has negative refractive power, and lens 9L42 (4-2) has its projection side S914 as concave. The image source side S915 is concave; the fifth lens group LG95 has positive refractive power; the projection side S921 and the image source side S922 of the 5-3 lens 9L53 are both aspherical surfaces; the 6-1 lens 9L61 is a meniscus lens, its projection side S923 is concave, and both the projection side S923 and the image source side S924 are spherical surfaces; the projection sides S925, S927, and S929 of the flat glass PG9, the prism P9, and the protective glass CG9, and the image source sides S926, S928, and S930 are all planar; by utilizing the above lens group, the aperture ST9, and the design that satisfies at least one of the conditions (1) to (7), the projection lens 9 can effectively reduce the aperture value, effectively increase the field of view, effectively correct aberrations, and effectively correct chromatic aberration. Table 25 is Figure 24 Table of relevant parameters for each lens when the projection lens 9 is at the wide-angle end (w) and the telescope end (t).

[0167] Table 25

[0168]

[0169]

[0170] The definition of the aspherical surface concavity z of the aspherical lens in Table 25 is the same as that in Table 1 of the first embodiment, and will not be repeated here. Table 26 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 25, where k is the conic constant and A to G are the aspherical coefficients.

[0171] Table 26

[0172]

[0173] Table 27 shows the relevant parameter values ​​of the projection lens 9 in the ninth embodiment and the calculated values ​​of the corresponding conditions (1) to (7). As can be seen from Table 27, the projection lens 9 in the ninth embodiment can meet the requirements of conditions (1) to (7).

[0174] Table 27

[0175]

[0176]

[0177] Furthermore, the optical performance of the projection lens 9 in the ninth embodiment also meets the requirements. Figure 25A It can be seen that the field curvature of the projection lens 9 in the ninth embodiment is between -0.02mm and 0.06mm at the wide-angle end. Figure 25B It can be seen that the distortion of the projection lens 9 in the ninth embodiment is between -1.2% and 0% at the wide-angle end. Figure 25C It can be seen that the modulation conversion function value of the projection lens 9 in the ninth embodiment is between 0.69 and 1.0 at the wide-angle end. Figure 25D It can be seen that, in the ninth embodiment, at the wide-angle end, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value of the projection lens 9 is between 0 and 0.8. Figure 26A It can be seen that the field curvature of the projection lens 9 in the ninth embodiment is between -0.1mm and 0.06mm at the telescope. Figure 26B It can be seen that the distortion of the projection lens 9 in the ninth embodiment is between -0.8% and 0% at the telescope. Figure 26C It can be seen that the modulation conversion function value of the projection lens 9 in the ninth embodiment is between 0.54 and 1.0. Figure 26D As can be seen, at the telescope distance, when the focus offset is between -0.05mm and 0.05mm, the modulation conversion function value is between 0.04 and 0.65. Clearly, the field curvature and distortion of the projection lens 9 in the ninth embodiment can be effectively corrected, and the lens resolution and depth of focus can also meet the requirements, thus achieving better optical performance.

[0178] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A projection lens characterized in that, include: The first lens group has negative refractive power; The second lens group has positive refractive power; The third lens group has positive refractive power; The fourth lens group has refractive power; The fifth lens group has refractive power; as well as The sixth lens group has positive refractive power; The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group are arranged sequentially along the optical axis from the projection side to the image source side. The first lens group includes lens 1-1 and lens 1-2. Lens 1-1 is a meniscus lens and lens 1-2 is a biconcave lens, including a concave surface facing the projection side and another concave surface facing the image source side. The third lens group consists of a 3-1 lens, which has positive refractive power; The fifth lens group consists of cemented lenses and 5-3 lenses; the cemented lenses consist of 5-1 lenses and 5-2 lenses, where 5-1 lens has negative refractive power, 5-2 lens has positive refractive power, and 5-3 lens has positive refractive power. The sixth lens group consists of a 6-1 lens, which has positive refractive power and includes a concave surface or a flat surface facing the projection side.

2. The projection lens as described in claim 1, characterized in that: The 1-1 lens has negative refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side; The 1-2 lens has negative refractive power; The second lens group includes a 2-1 lens, which has positive refractive power and includes a convex surface facing the image source side. When the 2-1 lens includes a convex surface facing the projection side, the 6-1 lens includes a flat surface facing the projection side; when the 2-1 lens includes a flat surface facing the projection side, the 6-1 lens includes a concave surface facing the projection side; when the 2-1 lens includes a concave surface facing the projection side, the 6-1 lens includes a concave surface facing the projection side. The third lens group includes a convex surface facing the projection side; The fourth lens group includes at least two lenses, wherein lens 4-1 is a biconvex lens with positive refractive power, and lens 4-2 has negative refractive power; and The 5-3 lens is a biconvex lens, and includes one convex surface facing the projection side and another convex surface facing the image source side. The cemented lens has negative refractive power. The 5-1 lens is a biconcave lens, and includes one concave surface facing the projection side and another concave surface facing the image source side. The 5-2 lens is a biconvex lens, and includes one convex surface facing the projection side and another convex surface facing the image source side.

3. The projection lens as described in claim 2, characterized in that: The 2-1 lens is a plano-convex lens, and further includes a plane facing the projection side; The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has positive refractive power. The 4-2 lens is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. This fifth lens group has negative refractive power, and; The 1-1 lens, the 1-2 lens, the 2-1 lens, the 3-1 lens, the 4-2 lens, the 4-1 lens, the 5-1 lens, the 5-2 lens, the 5-3 lens, and the 6-1 lens are arranged sequentially along the optical axis from the projection side to the image source side.

4. The projection lens as described in claim 2, characterized in that: The 2-1 lens is a biconvex lens, and further includes a convex surface facing the projection side; The 3-1 lens is a meniscus lens and further includes a concave surface facing the image source side; The fourth lens group has negative refractive power. The 4-2 lens is a biconcave lens, and includes a concave surface facing the projection side and another concave surface facing the image source side. The 4-2 lens is cemented with the 4-1 lens. This fifth lens group has positive refractive power; and The 1-1 lens, the 1-2 lens, the 2-1 lens, the 3-1 lens, the 4-2 lens, the 4-1 lens, the 5-1 lens, the 5-2 lens, the 5-3 lens, and the 6-1 lens are arranged sequentially along the optical axis from the projection side to the image source side.

5. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1, and lenses 1-4 disposed between lens 1-1 and lens 1-2. Lenses 1-3 are meniscus lenses with positive refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. Lenses 1-4 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The second lens group further includes a 2-2 lens disposed between the 2-1 lens and the third lens group. The 2-1 lens is a meniscus lens and further includes a concave surface facing the projection side. The 2-2 lens is a biconvex lens with positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source side. The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has positive refractive power and further includes a 4-3 lens disposed between the 4-1 lens and the fifth lens group; the 4-2 lens is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side; the 4-3 lens is a meniscus lens with negative refractive power and includes a concave surface facing the projection side and a convex surface facing the image source side; the 4-1 lens and the 4-3 lens are cemented together; and This fifth lens group has negative refractive power.

6. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1. Lenses 1-3 are meniscus lenses with positive refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The second lens group further includes a 2-2 lens disposed between the 2-1 lens and the third lens group. The 2-1 lens is a meniscus lens and further includes a concave surface facing the projection side. The 2-2 lens is a biconvex lens with positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source side. The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has positive refractive power and further includes a 4-3 lens disposed between the 4-1 lens and the fifth lens group; the 4-2 lens is a biconcave lens, including one concave surface facing the projection side and another concave surface facing the image source side; the 4-3 lens is a meniscus lens with negative refractive power, including one concave surface facing the projection side and one convex surface facing the image source side; the 4-1 lens and the 4-3 lens are cemented together; and This fifth lens group has negative refractive power.

7. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1. Lenses 1-3 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The second lens group further includes a 2-2 lens disposed between the 2-1 lens and the third lens group. The 2-1 lens is a meniscus lens and further includes a concave surface facing the projection side. The 2-2 lens is a biconvex lens with positive refractive power and includes a convex surface facing the projection side and another convex surface facing the image source side. The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has negative refractive power and further includes a 4-3 lens disposed between the 4-1 lens and the fifth lens group; the 4-2 lens is a meniscus lens and includes a concave surface facing the projection side and a convex surface facing the image source side; the 4-3 lens is a meniscus lens with negative refractive power and includes a concave surface facing the projection side and a convex surface facing the image source side; the 4-1 lens and the 4-3 lens are cemented together; and This fifth lens group has positive refractive power.

8. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1, and lenses 1-4 disposed between lenses 1-3 and lens 1-1. Lenses 1-3 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. Lenses 1-4 are meniscus lenses with positive refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The 2-1 lens is a biconvex lens, and further includes a convex surface facing the projection side; The 3-1 lens is a meniscus lens and further includes a concave surface facing the image source side; The fourth lens group has positive refractive power. Lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 4-2 is cemented to lens 4-1. This fifth lens group has positive refractive power.

9. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1. Lenses 1-3 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The 2-1 lens is a meniscus lens, and further includes a concave surface facing the projection side; The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has positive refractive power. Lens 4-2 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 4-2 is cemented to lens 4-1. This fifth lens group has negative refractive power.

10. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1, and lenses 1-4 disposed between lens 1-1 and lens 1-2. Lenses 1-3 are meniscus lenses with positive refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. Lenses 1-4 are meniscus lenses with negative refractive power and include a convex surface facing the projection side and a concave surface facing the image source side. The second lens group further includes a 2-2 lens disposed between the 2-1 lens and the third lens group. The 2-1 lens is a meniscus lens and further includes a concave surface facing the projection side. The 2-2 lens is a biconvex lens and includes a convex surface facing the projection side and another convex surface facing the image source side. The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has positive refractive power. Lens 4-2 is a biconcave lens, comprising one concave surface facing the projection side and another concave surface facing the image source side; and This fifth lens group has positive refractive power.

11. The projection lens as described in claim 2, characterized in that: The first lens group further includes lenses 1-3 disposed between the projection side and lens 1-1. Lenses 1-3 are biconvex lenses with positive refractive power and include one convex surface facing the projection side and another convex surface facing the image source side. The second lens group further includes a 2-2 lens disposed between the 2-1 lens and the third lens group. The 2-1 lens is a meniscus lens and further includes a concave surface facing the projection side. The 2-2 lens is a meniscus lens with positive refractive power and includes a convex surface facing the projection side and a concave surface facing the image source side. The 3-1 lens is a biconvex lens, and further includes a convex surface facing the image source side; The fourth lens group has negative refractive power. Lens 4-2 is a biconcave lens, comprising one concave surface facing the projection side and another concave surface facing the image source side; and This fifth lens group has positive refractive power.

12. The projection lens according to any one of claims 1 to 11, wherein The projection lens satisfies at least one of the following conditions: 6.02 < TTL / f < 23.34; 3.84 < TTL / BFL < 5.85; -5.28 < fCL / f < -1.17; 1 < (R 6-11 +R 6-12 ) / (R 6-11 -R 6-12 ) < 1.5; -1.51 < R 6-12 / BFL < -0.88; Vd6-1 < 21; -1.06 < fCL / f LG6 < -0.48; wherein TTL is the distance from the projection side surface of the lens closest to the projection side to the image source on the optical axis, BFL is the distance from the image source side surface of the 6-1 lens to the image source on the optical axis, f is the effective focal length of the projection lens, fCL is the effective focal length of the cemented lens, R 6-11 is the radius of curvature of the projection side surface of the 6-1 lens, 6-12 is the radius of curvature of the image source side surface of the 6-1 lens, Vd6-1 is the Abbe number of the 6-1 lens, f LG6 is the effective focal length of the sixth lens group.

13. The projection lens as described in any one of claims 1-11, characterized in that, The projection lens also includes an aperture. The spacing between these lens groups can be changed to allow the projection lens to zoom from the wide-angle end to the telephoto end. When the projection lens zooms, the first lens group is fixed or moves along the optical axis toward the image source side, the second lens group moves along the optical axis toward the projection side, the third lens group moves along the optical axis toward the projection side, the fourth lens group moves along the optical axis toward the projection side, the fifth lens group moves along the optical axis toward the projection side, and the sixth lens group is fixed. The aperture moves with the third lens group, moves with the fourth lens group, or moves independently. The first lens group can move along the optical axis to allow the projection lens to focus.

14. A projection lens, characterized in that, include: The first lens group has negative refractive power; The second lens group has positive refractive power; The third lens group has positive refractive power; The fourth lens group has refractive power; The fifth lens group has refractive power; as well as The sixth lens group has positive refractive power; the sixth lens group includes a 6-1 lens, which has positive refractive power and includes a concave surface or a flat surface facing the projection side; The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group are arranged sequentially along the optical axis from the projection side to the image source side. The first lens group includes lens 1-1 and lens 1-2. Lens 1-1 has negative refractive power. Lens 1-1 is a meniscus lens and includes a convex surface facing the projection side and a concave surface facing the image source side. Lens 1-2 has negative refractive power, is a biconcave lens, and includes a concave surface facing the projection side and another concave surface facing the image source side. The second lens group includes a 2-1 lens, which has positive refractive power and includes a convex surface facing the image source side. When the 2-1 lens includes a convex surface facing the projection side, the 6-1 lens includes a flat surface facing the projection side; when the 2-1 lens includes a flat surface facing the projection side, the 6-1 lens includes a concave surface facing the projection side; when the 2-1 lens includes a concave surface facing the projection side, the 6-1 lens includes a concave surface facing the projection side. The third lens group includes a 3-1 lens, which has positive refractive power and includes a convex surface facing the projection side; The fourth lens group includes at least two lenses, wherein lens 4-1 is a biconvex lens with positive refractive power and lens 4-2 has negative refractive power; The fifth lens group includes a cemented lens and a 5-3 lens. The 5-3 lens is a biconvex lens with positive refractive power and includes one convex surface facing the projection side and another convex surface facing the image source side. The cemented lens has negative refractive power and includes a 5-1 lens and a 5-2 lens. The 5-1 lens is a biconcave lens with negative refractive power and includes one concave surface facing the projection side and another concave surface facing the image source side. The 5-2 lens is a biconvex lens with positive refractive power and includes one convex surface facing the projection side and another convex surface facing the image source side.

15. A projection lens, characterized in that, include: The first lens group has negative refractive power; The second lens group has positive refractive power; The third lens group has positive refractive power; The fourth lens group has refractive power; The fifth lens group has refractive power; as well as The sixth lens group has positive refractive power, and this sixth lens group includes lens 6-1; The first lens group, the second lens group, the third lens group, the fourth lens group, the fifth lens group, and the sixth lens group are arranged sequentially along the optical axis from the projection side to the image source side. The first lens group includes lens 1-1 and lens 1-2. Lens 1-1 is a meniscus lens; lens 1-2 is a biconcave lens and includes one concave surface facing the projection side and another concave surface facing the image source side. The fifth lens group includes cemented lenses. The projection lens meets the following conditions: 1 < (R 6-11 +R 6-12 ) / (R 6-11 -R 6-12 ) < 1.5; wherein R 6-11 is the radius of curvature of the projection side surface of the 6-1 lens, and R 6-12 is the radius of curvature of the image source side surface of the 6-1 lens.

16. The projection lens as described in claim 15, characterized in that, The projection lens satisfies at least one of the following conditions: -5.28 < fCL / f < -1.17; -1.06 < fCL / f LG6 < -0.48; 6.02 < TTL / f < 23.34; 3.84 < TTL / BFL < 5.85; -1.51 < R 6-12 / BFL < -0.88; wherein f is an effective focal length of the projection lens, fCL is an effective focal length of the cemented lens, f LG6 is an effective focal length of the sixth lens group, TTL is a distance from a projection side surface of a lens closest to the projection side to an image source on the optical axis, BFL is a distance from an image source side surface of the 6-1 lens to the image source on the optical axis, R 6-12 is a radius of curvature of the image source side surface of the 6-1 lens.

Images