Zoom projection lens and imaging device

Abstract

The application relates to the field of optics, in particular to a zoom projection lens and an imaging device. The zoom projection lens is characterized in that the zoom projection lens is sequentially composed of a focusing lens group with negative optical power, a first fixed lens group with negative optical power, a first variable magnification lens group with negative optical power, a second variable magnification lens group with positive optical power, a third variable magnification lens group with positive optical power, a fourth variable magnification lens group with positive optical power, a second fixed lens group with positive optical power and a light splitting prism from the object plane side to the image plane side. The zoom projection lens satisfies the following conditional expressions: ft / fw<2; Fno<1.9; FOVt>80 DEG. Through the above structure and parameter limitation, the zoom projection lens realizes a small magnification, a large aperture effect, an ultralarge field of view, a large range of view and increased user experience.

Description

A zoom projection lens and imaging device Technical Field

[0001] This invention relates to the field of optics, specifically to a zoom projection lens and an imaging device. Background Technology

[0002] A zoom lens is a camera lens that can change its focal length within a certain range, thereby obtaining different widths of field of view, different image sizes, and different ranges of scenery. A zoom lens can change the shooting range by changing the focal length without changing the shooting distance, which is very beneficial for image composition. Since a zoom lens can perform the function of several prime lenses, it not only reduces the amount of photography equipment needed when traveling but also saves time changing lenses.

[0003] Currently, projection lenses typically use zoom technology to expand their application scenarios and resolution. However, existing projection lenses often use a large number of zoom groups within the zoom lens to increase the zoom range, thereby achieving a larger zoom range, but this results in a decrease in the resolution of the zoom lens. Summary of the Invention

[0004] This invention addresses existing technical problems by providing a zoom projection lens and imaging device. Through the aforementioned structure and parameter limitations, it achieves a large aperture effect while maintaining a small magnification of the zoom projection lens. It also enables a super-wide field of view, resulting in a larger framing range and enhanced user experience.

[0005] The technical solution provided by this invention is as follows:

[0006] A zoom projection lens, comprising, from the object plane side to the image plane side, a focusing lens group with negative optical power, a first fixed lens group with negative optical power, a first zoom lens group with negative optical power, a second zoom lens group with positive optical power, a third zoom lens group with positive optical power, a fourth zoom lens group with positive optical power, a second fixed lens group with positive optical power, and a beam splitter.

[0007] The first fixed lens group is a first fixed lens with negative optical power;

[0008] The second fixed lens group is a second fixed lens with positive optical power;

[0009] The third zoom lens is a fifth zoom lens with positive optical power;

[0010] The zoom projection lens satisfies the following condition:

[0011] ft / fw < 2;

[0012] Fno < 1.9;

[0013] FOVt > 80°;

[0014] Wherein, fw is the focal length of the zoom projection lens in wide-angle mode, ft is the focal length of the zoom projection lens in telephoto mode, Fno is the aperture number of the zoom projection lens, and FOVt is the field of view of the zoom projection lens in telephoto mode.

[0015] In this technical solution, by limiting the structure and parameters described above, a large aperture effect is achieved while maintaining a small magnification of the zoom projection lens. It also enables a super-large field of view, resulting in a wider framing range and enhancing the user experience.

[0016] Preferably, the focusing lens group consists of a first focusing lens with negative optical power and a second focusing lens with negative optical power, arranged sequentially from the object plane side to the image plane side.

[0017] Preferably, the first zoom lens group consists of a first zoom lens with negative optical power and a second zoom lens with positive optical power, arranged sequentially from the object plane side to the image plane side.

[0018] Preferably, the second zoom lens group consists of a third zoom lens with positive optical power and a fourth zoom lens with negative optical power, arranged sequentially from the object plane side to the image plane side, and the third zoom lens and the fourth zoom lens are cemented together.

[0019] Preferably, the fourth zoom lens group consists of, from the object plane side to the image plane side, a sixth zoom lens with positive optical power, a seventh zoom lens with negative optical power, an eighth zoom lens with positive optical power, a ninth zoom lens with negative optical power, a tenth zoom lens with positive optical power, an eleventh zoom lens with negative optical power, and a twelfth zoom lens with positive optical power; the seventh and eighth zoom lenses are cemented together, and the ninth, tenth, and eleventh zoom lenses form a cemented triplet lens.

[0020] Preferably, the zoom projection lens satisfies the following condition:

[0021] FG3 / f < -75;

[0022] Wherein, FG3 is the focal length of the first zoom lens group.

[0023] In this technical solution, by limiting the focal length of the first zoom lens group, the first zoom lens group can assist the second zoom lens group in zooming during the movement of the second zoom lens group, thereby further increasing the resolution of the zoom projection lens.

[0024] Preferably, the zoom projection lens satisfies the following condition:

[0025] 1.5 < XG4 / fw < 2;

[0026] Wherein, XG4 is the moving distance of the second zoom lens group.

[0027] In this technical solution, by limiting the moving distance of the second zoom lens group, the moving distance of the second zoom lens group is further increased on the basis of achieving a certain degree of zoom of the zoom projection lens, thereby increasing the resolution of the zoom projection lens.

[0028] Preferably, the zoom projection lens satisfies the following condition:

[0029] 0.2 < XG3 / XG4 < 0.3;

[0030] Wherein, XG3 is the moving distance of the first zoom lens group.

[0031] In this technical solution, by limiting the moving distance of the first zoom lens group, the total length of multiple zoom lens groups is reduced, and the total optical length of the zoom projection lens is reduced.

[0032] Preferably, the zoom projection lens satisfies the following condition:

[0033] 0.5 < XG6 / XG4 < 0.6;

[0034] Wherein, XG6 is the moving distance of the fourth zoom lens group.

[0035] In this technical solution, by limiting the moving distance of the fourth zoom lens group, the total length of multiple zoom lens groups is reduced, and the resolution of the zoom projection lens can be further increased.

[0036] Preferably, the zoom projection lens satisfies the following condition:

[0037] -4 < fc78 / fw < -3;

[0038] Wherein, fc78 is the combined focal length of the cemented lens composed of the seventh zoom lens c7 to the eighth zoom lens c8.

[0039] In this technical solution, the use of cemented lenses reduces reflection and scattering between lenses, resulting in a wider field of view and further increasing the field of view of the zoom projection lens.

[0040] One of the objectives of this invention is to provide an imaging device, comprising: a zoom projection lens; and an imaging element configured to receive an image formed by the zoom projection lens.

[0041] Compared with the prior art, the zoom projection lens and imaging device provided by the present invention have the following advantages:

[0042] Beneficial effects:

[0043] 1. By limiting the structure and parameters described above, a zoom projection lens can achieve a large aperture effect while maintaining a small magnification. It can also achieve an ultra-wide field of view, resulting in a larger framing range and enhancing the user experience.

[0044] 2. By limiting the focal length of the first zoom lens group, the first zoom lens group can assist the second zoom lens group in zooming during the movement of the second zoom lens group, thereby further increasing the resolution of the zoom projection lens.

[0045] 3. By using cemented lenses, reflections and scattering between lenses are reduced, resulting in a wider field of view and further increasing the field of view of the zoom projection lens. Attached Figure Description

[0046] The preferred embodiments will now be described in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of a zoom projection lens and imaging device.

[0047] Figure 1 is a schematic diagram of the structure of a zoom projection lens according to the present invention;

[0048] Figure 2 is a coma diagram of a zoom projection lens in telephoto mode according to the present invention.

[0049] Figure 3 is an aberration diagram of a zoom projection lens in telephoto mode according to the present invention;

[0050] Figure 4 is a coma diagram of a zoom projection lens in a wide-angle state according to the present invention;

[0051] Figure 5 is an aberration diagram of a zoom projection lens in a wide-angle state according to the present invention;

[0052] Figure 6 is a schematic diagram of another zoom projection lens of the present invention;

[0053] Figure 7 is a coma diagram of another zoom projection lens in telephoto mode according to the present invention;

[0054] Figure 8 is an aberration diagram of another zoom projection lens in telephoto mode according to the present invention;

[0055] Figure 9 is a coma diagram of another zoom projection lens in a wide-angle state according to the present invention;

[0056] Figure 10 is an aberration diagram of another zoom projection lens in the wide-angle state according to the present invention.

[0057] Explanation of reference numerals: G1, Focusing lens group; G2, First fixed lens group; G3, First zoom lens group; G4, Second zoom lens group; G5, Third zoom lens group; G6, Fourth zoom lens group; G7, Second fixed lens group; a1, First focusing lens; a2, Second focusing lens; b1, First fixed lens; b2, Second fixed lens; c1, First zoom lens; c2, Second zoom lens; c3, Third zoom lens; c4, Fourth zoom lens; c5, Fifth zoom lens; c6, Sixth zoom lens; c7, Seventh zoom lens; c8, Eighth zoom lens; c9, Ninth zoom lens; c10, Tenth zoom lens; c11, Eleventh zoom lens; c12, Twelfth zoom lens; P, Beam splitter; STO, Aperture stop. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0060] Example 1

[0061] As shown in Figures 1 and 6, a zoom projection lens is composed of, from the object plane side to the image plane side, a focusing lens group G1 with negative optical power, a first fixed lens group G2 with negative optical power, a first zoom lens group G3 with negative optical power, a second zoom lens group G4 with positive optical power, a third zoom lens group G5 with positive optical power, a fourth zoom lens group G6 with positive optical power, a second fixed lens group G7 with positive optical power, and a beam splitter P.

[0062] The first fixed lens group G2 is a first fixed lens b1 with negative optical power;

[0063] The second fixed lens group G7 is a second fixed lens b2 with positive optical power;

[0064] The third zoom lens c3 is a fifth zoom lens c5 with positive optical power;

[0065] The zoom projection lens satisfies the following condition:

[0066] ft / fw < 2;

[0067] Fno < 1.9;

[0068] FOVt > 80°;

[0069] Wherein, FOVt is the field of view of the zoom projection lens in telephoto mode, and Fno is the aperture number of the zoom projection lens.

[0070] By limiting the structure and parameters described above, a zoom projection lens can achieve a large aperture effect while maintaining a small magnification, as well as an ultra-wide field of view, resulting in a larger framing range and enhanced user experience.

[0071] The focusing lens group G1 consists of a first focusing lens a1 with negative optical power and a second focusing lens a2 with negative optical power, arranged sequentially from the object plane side to the image plane side.

[0072] The first zoom lens group G3 consists of a first zoom lens c1 with negative optical power and a second zoom lens c2 with positive optical power, arranged sequentially from the object plane side to the image plane side.

[0073] The second zoom lens group G4 consists of a third zoom lens c3 with positive optical power and a fourth zoom lens c4 with negative optical power, arranged sequentially from the object plane side to the image plane side. The third zoom lens c3 and the fourth zoom lens c4 are cemented together.

[0074] The fourth zoom lens group G6 consists of, from the object plane side to the image plane side, a sixth zoom lens c6 with positive optical power, a seventh zoom lens c7 with negative optical power, an eighth zoom lens c8 with positive optical power, a ninth zoom lens c9 with negative optical power, a tenth zoom lens c10 with positive optical power, an eleventh zoom lens c11 with negative optical power, and a twelfth zoom lens c12 with positive optical power; the seventh zoom lens c7 and the eighth zoom lens c8 are cemented together, and the ninth zoom lens c9, the tenth zoom lens c10, and the eleventh zoom lens c11 form a cemented triplet lens.

[0075] The zoom projection lens satisfies the following condition:

[0076] FG3 / fw < -75;

[0077] Wherein, FG3 is the focal length of the first zoom lens group G3.

[0078] By limiting the focal length of the first zoom lens group G3, the first zoom lens group G3 can assist the second zoom lens group G4 in zooming during the movement of the second zoom lens group G4, thereby further increasing the resolution of the zoom projection lens.

[0079] The zoom projection lens satisfies the following condition:

[0080] 1.5 < XG4 / fw < 2;

[0081] Wherein, XG4 is the moving distance of the second zoom lens group G4.

[0082] By limiting the moving distance of the second zoom lens group G4, the moving distance of the second zoom lens group G4 is further increased on the basis of achieving a certain degree of zoom of the zoom projection lens, thereby increasing the resolution of the zoom projection lens.

[0083] The zoom projection lens satisfies the following condition:

[0084] 0.2 < XG3 / XG4 < 0.3;

[0085] Wherein, XG3 is the moving distance of the first zoom lens group G3.

[0086] By limiting the moving distance of the first zoom lens group G3, the total length of multiple zoom lens groups is reduced, thus reducing the total optical length of the zoom projection lens.

[0087] The zoom projection lens satisfies the following condition:

[0088] 0.5 < XG6 / XG4 < 0.6;

[0089] Wherein, XG6 is the moving distance of the fourth zoom lens group G6.

[0090] By limiting the moving distance of the fourth zoom lens group G6, the total length of multiple zoom lens groups is reduced, and the resolution of the zoom projection lens can be further increased.

[0091] The zoom projection lens satisfies the following condition:

[0092] -4 < fc78 / fw < -3;

[0093] Wherein, fc78 is the combined focal length of the cemented lens composed of the seventh zoom lens c7 to the eighth zoom lens c8.

[0094] By using cemented lenses, reflections and scattering between lenses are reduced, resulting in a wider field of view and further increasing the field of view of the zoom projection lens.

[0095] Example 2

[0096] As shown in Figures 1 to 5, a zoom projection lens is composed of, from the object plane side to the image plane side, a focusing lens group G1 with negative optical power, a first fixed lens group G2 with negative optical power, a first zoom lens group G3 with negative optical power, a second zoom lens group G4 with positive optical power, a third zoom lens group G5 with positive optical power, a fourth zoom lens group G6 with positive optical power, a second fixed lens group G7 with positive optical power, and a beam splitter P.

[0097] The focusing lens group G1 consists of a first focusing lens a1 with negative optical power and a second focusing lens a2 with negative optical power, arranged sequentially from the object plane side to the image plane side.

[0098] The first fixed lens group G2 is a first fixed lens b1 with negative optical power;

[0099] The first zoom lens group G3 consists of a first zoom lens c1 with negative optical power and a second zoom lens c2 with positive optical power, arranged sequentially from the object plane side to the image plane side.

[0100] The second zoom lens group G4 consists of a third zoom lens c3 with positive optical power and a fourth zoom lens c4 with negative optical power, arranged sequentially from the object plane side to the image plane side. The third zoom lens c3 and the fourth zoom lens c4 are cemented together.

[0101] The third zoom lens c3 is a fifth zoom lens c5 with positive optical power.

[0102] The fourth zoom lens group G6 consists of, from the object plane side to the image plane side, a sixth zoom lens c6 with positive optical power, a seventh zoom lens c7 with negative optical power, an eighth zoom lens c8 with positive optical power, a ninth zoom lens c9 with negative optical power, a tenth zoom lens c10 with positive optical power, an eleventh zoom lens c11 with negative optical power, and a twelfth zoom lens c12 with positive optical power; the seventh zoom lens c7 and the eighth zoom lens c8 are cemented together, and the ninth zoom lens c9, the tenth zoom lens c10, and the eleventh zoom lens c11 form a cemented triplet lens.

[0103] The second fixed lens group G7 is a second fixed lens b2 with positive optical power;

[0104] The basic lens data of the zoom projection lens in this embodiment is shown in Table 1, the variable parameters in Table 1 are shown in Table 2, and the aspherical coefficients are shown in Table 3.

[0105] The surface number column shows the surface number when the object-side surface is set as surface 1 and the numbering is increased sequentially towards the image side; the surface type column shows the surface type of a lens; the radius of curvature column shows the radius of curvature of a lens, where a positive radius of curvature indicates that the surface is curved towards the object side and a negative radius of curvature indicates that the surface is curved towards the image side; the center thickness column shows the surface spacing on the optical axis between each surface and the surface adjacent to it on the image side; the refractive index column shows the refractive index of a lens; and the Abbe number column shows the Abbe number of a lens.

[0106] In Table 2, the WIDE column indicates the specific values ​​of each variable parameter when the zoom projection lens is in the wide-angle end state, and the TELE column indicates the specific values ​​of each variable parameter when the zoom projection lens is in the telephoto end state.

[0107] In Table 3, K is the conic coefficient, and e is the scientific notation, for example, e-05 represents 10. -5 .

[0108] Table 1

[0109]

[0110]

[0111] Table 2

[0112] WIDETELED119.3815.8D219.286.6D30.22.9D411.1815.3D52.0711.6 surface

[0113] Table 3

[0114]

[0115]

[0116] In this embodiment, fw = 9.25 mm, ft = 11.5 mm, ft / fw = 1.24; Fno = 1.71~1.83, TTL = 230.03 mm, FOVt = 87.82°, FOVw = 100.42°;

[0117] Wherein, fw is the focal length of the zoom projection lens in wide-angle mode, ft is the focal length of the zoom projection lens in telephoto mode, Fno is the aperture number of the zoom projection lens, TTL is the total optical length of the zoom projection lens, FOVt is the field of view of the zoom projection lens in telephoto mode, and FOVw is the field of view of the zoom projection lens in wide-angle mode.

[0118] FG3=-736.72mm; FG3 / fw=-79.6;

[0119] Wherein, FG3 is the focal length of the first zoom lens group G3.

[0120] XG4=16.3mm, XG4 / fw=1.76;

[0121] XG3=3.6mm; XG3 / XG4=0.22;

[0122] XG6=9.5mm; XG6 / XG4=0.58;

[0123] Wherein, XG3 is the moving distance of the first zoom lens group G3, XG4 is the moving distance of the second zoom lens group G4, and XG6 is the moving distance of the fourth zoom lens group G6.

[0124] fc78=-33.59mm; fc78 / fw=-3.63;

[0125] Wherein, fc78 is the combined focal length of the cemented lens composed of the seventh zoom lens c7 to the eighth zoom lens c8.

[0126] Example 3

[0127] As shown in Figures 6 to 10, a zoom projection lens is composed of, from the object plane side to the image plane side, a focusing lens group G1 with negative optical power, a first fixed lens group G2 with negative optical power, a first zoom lens group G3 with negative optical power, a second zoom lens group G4 with positive optical power, a third zoom lens group G5 with positive optical power, a fourth zoom lens group G6 with positive optical power, a second fixed lens group G7 with positive optical power, and a beam splitter P.

[0128] The focusing lens group G1 consists of a first focusing lens a1 with negative optical power and a second focusing lens a2 with negative optical power, arranged sequentially from the object plane side to the image plane side.

[0129] The first fixed lens group G2 is a first fixed lens b1 with negative optical power;

[0130] The first zoom lens group G3 consists of a first zoom lens c1 with negative optical power and a second zoom lens c2 with positive optical power, arranged sequentially from the object plane side to the image plane side.

[0131] The second zoom lens group G4 consists of a third zoom lens c3 with positive optical power and a fourth zoom lens c4 with negative optical power, arranged sequentially from the object plane side to the image plane side. The third zoom lens c3 and the fourth zoom lens c4 are cemented together.

[0132] The third zoom lens c3 is a fifth zoom lens c5 with positive optical power.

[0133] The fourth zoom lens group G6 consists of, from the object plane side to the image plane side, a sixth zoom lens c6 with positive optical power, a seventh zoom lens c7 with negative optical power, an eighth zoom lens c8 with positive optical power, a ninth zoom lens c9 with negative optical power, a tenth zoom lens c10 with positive optical power, an eleventh zoom lens c11 with negative optical power, and a twelfth zoom lens c12 with positive optical power; the seventh zoom lens c7 and the eighth zoom lens c8 are cemented together, and the ninth zoom lens c9, the tenth zoom lens c10, and the eleventh zoom lens c11 form a cemented triplet lens.

[0134] The second fixed lens group G7 is a second fixed lens b2 with positive optical power;

[0135] The basic lens data of the zoom projection lens in this embodiment is shown in Table 4, the variable parameters in Table 4 are shown in Table 5, and the aspherical coefficients are shown in Table 6.

[0136] The surface number column shows the surface number when the object-side surface is set as surface 1 and the numbering is increased sequentially towards the image side; the surface type column shows the surface type of a lens; the radius of curvature column shows the radius of curvature of a lens, where a positive radius of curvature indicates that the surface is curved towards the object side and a negative radius of curvature indicates that the surface is curved towards the image side; the center thickness column shows the surface spacing on the optical axis between each surface and the surface adjacent to it on the image side; the refractive index column shows the refractive index of a lens; and the Abbe number column shows the Abbe number of a lens.

[0137] In Table 5, the WIDE column indicates the specific values ​​of each variable parameter when the zoom projection lens is in the wide-angle end state, and the TELE column indicates the specific values ​​of each variable parameter when the zoom projection lens is in the telephoto end state.

[0138] In Table 6, K is the conic coefficient, and e is the scientific notation, for example, e-05 represents 10. -5 .

[0139] Table 4

[0140]

[0141]

[0142] Table 5

[0143] WIDETELED119.5316.5D219.588.1D30.23.3D410.613.9D55.6113.7 surface

[0144] Table 6

[0145]

[0146] In this embodiment, fw = 9.7 mm, ft = 11.65 mm, ft / fw = 1.2; Fno = 1.7~1.8, TTL = 230 mm, FOVt = 86.86°, FOVw = 97.12°;

[0147] Wherein, fw is the focal length of the zoom projection lens in wide-angle mode, ft is the focal length of the zoom projection lens in telephoto mode, Fno is the aperture number of the zoom projection lens, TTL is the total optical length of the zoom projection lens, FOVt is the field of view of the zoom projection lens in telephoto mode, and FOVw is the field of view of the zoom projection lens in wide-angle mode.

[0148] FG3=-1262.69mm; FG3 / fw=-130.17;

[0149] Wherein, FG3 is the focal length of the first zoom lens group G3.

[0150] XG4=14.6mm, XG4 / fw=1.51;

[0151] XG3=3.1mm; XG3 / XG4=0.21;

[0152] XG6=8.2mm; XG6 / XG4=0.56;

[0153] Wherein, XG3 is the moving distance of the first zoom lens group G3, XG4 is the moving distance of the second zoom lens group G4, and XG6 is the moving distance of the fourth zoom lens group G6.

[0154] fc78=-36.91mm; fc78 / fw=-3.81;

[0155] Wherein, fc78 is the combined focal length of the cemented lens composed of the seventh zoom lens c7 to the eighth zoom lens c8.

[0156] Example 4

[0157] An imaging apparatus, as shown in Figures 1 to 10, includes: a zoom projection lens as described in any of the above embodiments, and an imaging element configured to receive an image formed by the zoom projection lens.

[0158] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A zoom projection lens, characterized in that, The zoom projection lens, from the object plane side to the image plane side, consists of a focusing lens group with negative optical power, a first fixed lens group with negative optical power, a first zoom lens group with negative optical power, a second zoom lens group with positive optical power, a third zoom lens group with positive optical power, a fourth zoom lens group with positive optical power, a second fixed lens group with positive optical power, and a beam splitter; the first fixed lens group is a first fixed lens with negative optical power; the second fixed lens group is a second fixed lens with positive optical power; and the third zoom lens group is a fifth zoom lens with positive optical power. The first, second, third, and fourth zoom lens groups move along the principal optical axis of the zoom projection lens; the zoom projection lens satisfies the following conditions: ft / fw < 2; 1.7 ≤ Fno < 1.9; 80° < FOVt ≤ 100.42°; where fw is the focal length of the zoom projection lens in wide-angle mode, ft is the focal length of the zoom projection lens in telephoto mode, Fno is the aperture number of the zoom projection lens, and FOVt is the field of view of the zoom projection lens in telephoto mode.

2. A zoom projection lens according to claim 1, characterized in that: The focusing lens group consists of a first focusing lens with negative optical power and a second focusing lens with negative optical power, arranged sequentially from the object plane side to the image plane side.

3. A zoom projection lens according to claim 1, characterized in that: The first zoom lens group consists of a first zoom lens with negative optical power and a second zoom lens with positive optical power, arranged sequentially from the object plane side to the image plane side.

4. A zoom projection lens according to claim 1, characterized in that: The second zoom lens group consists of a third zoom lens with positive optical power and a fourth zoom lens with negative optical power, arranged sequentially from the object plane side to the image plane side. The third zoom lens and the fourth zoom lens are cemented together.

5. A zoom projection lens according to claim 1, characterized in that: The fourth zoom lens group consists of, from the object plane side to the image plane side, a sixth zoom lens with positive optical power, a seventh zoom lens with negative optical power, an eighth zoom lens with positive optical power, a ninth zoom lens with negative optical power, a tenth zoom lens with positive optical power, an eleventh zoom lens with negative optical power, and a twelfth zoom lens with positive optical power; the seventh and eighth zoom lenses are cemented together, and the ninth, tenth, and eleventh zoom lenses form a cemented triplet lens.

6. A zoom projection lens according to claim 1, characterized in that: The zoom projection lens satisfies the following condition: FG3 / fw < -75; where FG3 is the focal length of the first zoom lens group.

7. A zoom projection lens according to claim 1, characterized in that: The zoom projection lens satisfies the following condition: 1.5 < XG4 / fw < 2; where XG4 is the moving distance of the second zoom lens group.

8. A zoom projection lens according to claim 7, characterized in that: The zoom projection lens satisfies the following condition: 0.2 < XG3 / XG4 < 0.3; where XG3 is the moving distance of the first zoom lens group.

9. A zoom projection lens according to claim 7, characterized in that: The zoom projection lens satisfies the following condition: 0.5 < XG6 / XG4 < 0.6; where XG6 is the moving distance of the fourth zoom lens group.

10. A zoom projection lens according to claim 5, characterized in that: The zoom projection lens satisfies the following condition: -4 < fc78 / fw < -3; where fc78 is the combined focal length of the cemented lens composed of the seventh to eighth zoom lenses.

11. An imaging device, characterized in that, include: The zoom projection lens as described in any one of claims 1 to 10; An imaging element is configured to receive an image formed by the zoom projection lens.

Images