Zoom projection lens

Abstract

The invention relates to a zoom projection lens, which sequentially comprises a front fixed lens group, a focusing lens group, a plurality of zoom lens groups and a rear fixed lens group from the magnification side to the reduction side of the lens, and is used for satisfying 1lt; f < t > / F < wlt >; 2 and 10 lt; oAL / IMHlt; 24, Ft is the effective focal length of the telephoto end, Fw is the effective focal length of the wide-angle end, OAL is the distance from the first lens of the lens to the focal plane, and IMH is the half height of the focal plane. Therefore, the zoom projection lens provided by the invention has the effects of meeting the zoom projection requirement and giving consideration to the projection imaging quality.

Description

Technical Field

[0001] The present invention relates to a zoom projection lens, particularly a design that meets the zoom projection requirements and takes into account the projection imaging quality. Background Art

[0002] There is a corresponding relationship between the brightness of the projector and the ambient brightness. When using the projector in a brighter environment, a projector with a higher brightness must be used. Furthermore, in addition to meeting the requirements of the aforementioned high-brightness projection, the projection lens usually needs to zoom through several lens groups inside the lens according to the installation position of the projector to adjust the projection screen to an appropriate size. Therefore, enabling the projection lens to simultaneously meet the projection requirements of high brightness and zoom while also taking into account the projection imaging quality is the problem to be solved by the present invention. Summary of the Invention

[0003] The main technical problem to be solved by the present invention is to overcome the above-mentioned defects existing in the prior art and provide a zoom projection lens that has the effect of meeting the zoom projection requirements and taking into account the projection imaging quality.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows:

[0005] A zoom projection lens sequentially includes, from the magnifying side to the reducing side of the lens: a front fixed lens group, a focusing lens group, several zoom lens groups, and a rear fixed lens group, so as to satisfy 1 < Ft / Fw < 2 and 10 < OAL / IMH < 24, where Ft is the effective focal length at the telephoto end, Fw is the effective focal length at the wide-angle end, OAL is the distance from the first lens of the lens to the focal plane, and IMH is the semi-height of the focal plane.

[0006] The focusing lens group includes at least one lens with a positive refractive power. The zoom lens group with the largest number of lenses among the several zoom lens groups has a positive refractive power and includes at least two lenses with a positive refractive power. Among the several zoom lens groups, there are two zoom lens groups that each include at least one lens with a positive refractive power.

[0007] The front fixed lens group has a positive refractive power, the focusing lens group has a negative refractive power, and the several zoom lens groups sequentially include, after the focusing lens group: a first zoom lens group with a positive refractive power, a second zoom lens group with a positive refractive power, a third zoom lens group with a negative refractive power, and a fourth zoom lens group with a positive refractive power. The rear fixed lens group has a positive refractive power; among them, the fourth zoom lens group is the zoom lens group with the largest number of lenses among the several zoom lens groups.

[0008] The front fixed lens group has negative refractive power, the focusing lens group has negative refractive power, and the plurality of zoom lens groups include, following the focusing lens group, a first zoom lens group with positive refractive power, a second zoom lens group with positive refractive power, a third zoom lens group with negative refractive power, a fourth zoom lens group with positive refractive power, and a fifth zoom lens group with positive refractive power. The rear fixed lens group has positive refractive power; wherein the fourth zoom lens group is the zoom lens group with the largest number of lenses among the plurality of zoom lens groups.

[0009] The beneficial effect of the present invention is that it can meet the needs of zoom projection while taking into account the projection imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described below with reference to the accompanying drawings and examples.

[0011] Figure 1A Schematic diagram of the lens configuration at the wide-angle end of the first embodiment of the present invention.

[0012] Figure 1B Schematic diagram of the lens configuration at the telephoto end of the first embodiment of the present invention.

[0013] Figure 1C This is a light aberration diagram of Example 1 of the present invention at the wide-angle end.

[0014] Figure 1D 1. The longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the first embodiment of the present invention at the wide-angle end.

[0015] Figure 1E This is a light aberration diagram of the first embodiment of the present invention at the telephoto end.

[0016] Figure 1F This is a diagram of longitudinal spherical aberration, astigmatism, and distortion at the telephoto end of the first embodiment of the present invention.

[0017] Figure 2A Schematic diagram of the lens configuration at the wide-angle end of the second embodiment of the present invention.

[0018] Figure 2B Schematic diagram of the lens configuration at the telephoto end of the second embodiment of the present invention.

[0019] Figure 2C This is a light aberration diagram of the second embodiment of the present invention at the wide-angle end.

[0020] Figure 2D These are the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the second embodiment of the present invention at the wide-angle end.

[0021] Figure 2E This is a light aberration diagram of the second embodiment of the present invention at the telephoto end.

[0022] Figure 2FThese are the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the second embodiment of the present invention at the telephoto end.

[0023] Description of the numbers in the figure:

[0024] 10, 20 zoom projection lens

[0025] 11, 21 front fixed lens group

[0026] 12, 22 focusing lens groups

[0027] 13, 23 First zoom lens group

[0028] 14, 24 Second zoom lens group

[0029] 15, 25 third zoom lens group

[0030] 16, 26 fourth zoom lens group

[0031] 27Fifth zoom lens group

[0032] 17, 28 rear fixed lens group

[0033] 1G1, 2G1 first lens

[0034] 1G2, 2G2 second lens

[0035] 1G3, 2G3 third lens

[0036] 1G4, 2G4 fourth lens

[0037] 1G5, 2G5 fifth lens

[0038] 1G6, 2G6 sixth lens

[0039] 1G7, 2G7 seventh lens

[0040] 1G8, 2G8 eighth lens

[0041] 1G9, 2G9 ninth lens

[0042] 1G10, 2G10 tenth lens

[0043] 1G11, 2G11 eleventh lens

[0044] 1G12, 2G12 twelfth lens

[0045] 1G13, 2G13 thirteenth lens

[0046] 1G14, 2G14 fourteenth lens

[0047] 1G15, 2G15 fifteenth lens

[0048] 1G16, 2G16 sixteenth lens

[0049] 1G17, 2G17 seventeenth lens

[0050] 1G18, 2G18 eighteenth lens

[0051] S-iris

[0052] T-type smooth image device

[0053] P-prism

[0054] C cover glass

[0055] IMA Image Source DETAILED DESCRIPTION

[0056] First, see Figure 1A 、 Figure 1B As shown, the zoom projection lens 10 of the first embodiment of the present invention includes, from the magnification side to the reduction side of the lens, the following components:

[0057] The front fixed lens group 11 has a positive refractive power and includes a first lens 1G1;

[0058] The focusing lens group 12 has a negative refractive power and includes, in order, a second lens 1G2, a third lens 1G3, a fourth lens 1G4, a fifth lens 1G5, a sixth lens 1G6, and a seventh lens 1G7. The refractive power of the sixth lens 1G6 is positive.

[0059] The first zoom lens group 13 has a positive refractive power and includes an eighth lens 1G8. The eighth lens 1G8 has a positive refractive power.

[0060] The second zoom lens group 14 has a positive refractive power and includes a ninth lens 1G9. The ninth lens 1G9 has a positive refractive power.

[0061] The third zoom lens group 15 has a negative refractive power and includes a tenth lens 1G10 and an eleventh lens 1G11 in this order. The refractive power of the eleventh lens 1G11 is positive.

[0062] Aperture S;

[0063] a fourth zoom lens group 16 having positive refractive power and including, in order, a twelfth lens 1G12, a thirteenth lens 1G13, a fourteenth lens 1G14, a fifteenth lens 1G15, a sixteenth lens 1G16, and a seventeenth lens 1G17; the twelfth lens 1G12, the fourteenth lens 1G14, the sixteenth lens 1G16, and the seventeenth lens 1G17 having positive refractive power;

[0064] The rear fixed lens group 17 has a positive refractive power and includes an eighteenth lens 1G18; and

[0065] The transmissive smooth picture actuator T is sequentially arranged behind the eighteenth lens 1G18, and behind the transmissive smooth picture actuator T, a prism P, a cover glass C, and an image source IMA are sequentially arranged;

[0066] Thereby, it is used to satisfy 1 < Ft / Fw < 2 and 10 < OAL / IMH < 24, where Ft is the effective focal length at the telephoto end, Fw is the effective focal length at the wide-angle end, OAL is the distance from the first lens of the lens to the focal plane, and IMH is half the height of the focal plane.

[0067] The lens design parameters of the zoom projection lens 10 are shown in Table 1:

[0068]

[0069]

[0070]

[0071] Table 1

[0072] Figure 1C is the ray aberration diagram of the wide-angle end of the zoom projection lens 10. With the first wavelength (λ1) of 620 nm, the second wavelength (λ2) of 550 nm, and the third wavelength (λ3) of 460 nm, and the relative field heights being 1.00, 0.75, 0.50, 0.25, 0.00 respectively, the corresponding ray aberrations of different Y-fan rays and X-fan rays are simulated respectively, so that the relative field heights of 1.00, 0.75, 0.50, 0.25, 0.00 present half-angles of (34.34°), (27.18°), (18.86°), (9.656°), (0.000°) respectively. And from the ray aberration diagram, the maximum aberration of each field point is controlled within the range of (-0.02 mm, 0.02 mm).

[0073] Figure 1DThe diagram includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram at the wide-angle end of the zoom projection lens 10. The longitudinal spherical aberration diagram shows the deviation of the convergent focus of light of different wavelengths passing through the lens. The longitudinal spherical aberration diagram shows that the maximum focus shift at each reference wavelength is controlled within the range of (-0.010m, 0.040mm). The curves T and S of the astigmatic field curves are the tangential field curvature characteristic curve and the sagittal field curvature characteristic curve, respectively. The astigmatic field curvature diagram shows that the meridional field curvature value and the sagittal field curvature value at a wavelength of 550nm are controlled within the range of (-0.025mm, 0.025mm). The distortion diagram shows that the distortion at a wavelength of 550nm is controlled within the range of (-1.50%, 0).

[0074] Figure 1E The figure shows the light aberration diagram of the zoom projection lens 10 at the telephoto end. The light aberrations corresponding to different Y-fan-shaped and X-fan-shaped rays are simulated using a first wavelength (λ1) of 620 nm, a second wavelength (λ2) of 550 nm, and a third wavelength (λ3) of 460 nm, respectively, with relative field heights of 1.00, 0.75, 0.50, 0.25, and 0.00. The half-viewing angles of 1.00, 0.75, 0.50, 0.25, and 0.00 are respectively (23.24°), (17.87°), (12.12°), (6.126°), and (0.000°). The light aberration diagram shows that the maximum aberration at each field point is controlled within the range of (-0.02 mm, 0.02 mm).

[0075] Figure 1F It includes the longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the telephoto end of the zoom projection lens 10; it can be seen from the longitudinal spherical aberration diagram that the maximum focus offset of each reference wavelength is controlled within the range of (-0.010m, 0.040mm); the curves T and S of the field curvature astigmatism diagram are the meridional field curvature characteristic curve and the sagittal field curvature characteristic curve, respectively. It can be seen from the field curvature astigmatism diagram that the meridional field curvature value and the sagittal field curvature value at a wavelength of 550nm are controlled within the range of (-0.025mm, 0.020mm); the distortion diagram shows that the distortion amount at a wavelength of 550nm is controlled within the range of (-0.50%, 0).

[0076] Next, see Figure 2A 、 Figure 2B As shown, the zoom projection lens 20 of the second embodiment of the present invention includes, from the magnification side to the reduction side of the lens, the following components:

[0077] The front fixed lens group 21 has a negative refractive power and sequentially includes a first lens 2G1, a second lens 2G2, a third lens 2G3, a fourth lens 2G4, and a fifth lens 2G5;

[0078] The focusing lens group 22 has a negative refractive power and sequentially includes a sixth lens 2G6 and a seventh lens 2G7, and the seventh lens 2G7 has a positive refractive power;

[0079] The first zoom lens group 23 has a positive refractive power and includes an eighth lens 2G8, and the eighth lens 2G8 has a positive refractive power;

[0080] The second zoom lens group 24 has a positive refractive power and includes a ninth lens 2G9, and the ninth lens 2G9 has a positive refractive power;

[0081] The third zoom lens group 25 has a negative refractive power and includes a tenth lens 2G10;

[0082] An aperture S;

[0083] The fourth zoom lens group 26 has a positive refractive power and sequentially includes an eleventh lens 2G11, a twelfth lens 2G12, a thirteenth lens 2G13, a fourteenth lens 2G14, a fifteenth lens 2G15, and a sixteenth lens 2G16. The eleventh lens 2G11, the thirteenth lens 2G13, and the fifteenth lens 2G15 have positive refractive powers;

[0084] The fifth zoom lens group 27 has a positive refractive power and includes a seventeenth lens 2G17, and the seventeenth lens 2G17 has a positive refractive power;

[0085] The rear fixed lens group 28 has a positive refractive power and includes an eighteenth lens 2G18; and

[0086] A transmissive smooth image device T is sequentially arranged after the eighteenth lens 2G1, and a prism P, a cover glass C, and an image source IMA are sequentially arranged after the transmissive smooth image device T;

[0087] Thereby, it is used to satisfy 1 < Ft / Fw < 2 and 10 < OAL / IMH < 24, where Ft is the effective focal length at the telephoto end, Fw is the effective focal length at the wide-angle end, OAL is the distance from the first lens of the lens to the focal plane, and IMH is half the height of the focal plane.

[0088] The lens design parameters of the zoom projection lens 20 are shown in Table 2:

[0089]

[0090]

[0091] Figure 2CThe figure shows the light aberration diagram of the zoom projection lens 20 at the wide-angle end. A first wavelength (λ1) of 620 nm, a second wavelength (λ2) of 550 nm, and a third wavelength (λ3) of 460 nm are used, and relative field heights of 1.00, 0.75, 0.50, 0.25, and 0.00 are used to simulate the corresponding light aberrations of different Y-fan-shaped light and X-fan-shaped light. The relative field heights of 1.00, 0.75, 0.50, 0.25, and 0.00 respectively present half viewing angles of (33.15°), (25.96°), (17.88°), (9.122°), and (0.000°). The light aberration diagram shows that the maximum aberration at each field point is controlled within the range of (-0.01 mm, 0.01 mm).

[0092] Figure 2D The diagram includes a longitudinal spherical aberration diagram, an astigmatism diagram, and a distortion diagram for the wide-angle end of the zoom projection lens 20. The longitudinal spherical aberration diagram shows that the maximum focus shift at each reference wavelength is controlled within the range of (-0.040m, 0.025mm). Curves Y and X of the field curvature astigmatism diagram are the meridional field curvature characteristic curve and the sagittal field curvature characteristic curve, respectively. The field curvature astigmatism diagram shows that the meridional field curvature value and the sagittal field curvature value at a wavelength of 550nm are controlled within the range of (-0.020mm, 0.020mm). The distortion diagram shows that the distortion at a wavelength of 550nm is controlled within the range of (-2.50%, 0).

[0093] Figure 2E The figure shows the light aberration diagram of the zoom projection lens 20 at the telephoto end. A first wavelength (λ1) of 620 nm, a second wavelength (λ2) of 550 nm, and a third wavelength (λ3) of 460 nm are used, and relative field heights of 1.00, 0.75, 0.50, 0.25, and 0.00 are used to simulate the corresponding light aberrations of different Y-fan-shaped light and X-fan-shaped light. The relative field heights of 1.00, 0.75, 0.50, 0.25, and 0.00 respectively present half viewing angles of (22.33°), (17.03°), (11.49°), (5.788°), and (0.000°). The light aberration diagram shows that the maximum aberration at each field point is controlled within the range of (-0.02 mm, 0.015 mm).

[0094] Figure 2FIncluding the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the telephoto end of the zoom projection lens 20; from the longitudinal spherical aberration diagram, it can be seen that the maximum focal shift of each reference wavelength is controlled within the range of (-0.10 m, 0.05 mm); the curves Y and X of the field curvature and astigmatism diagram are the meridional field curvature characteristic curve and the sagittal field curvature characteristic curve respectively. From the field curvature and astigmatism diagram, it can be seen that the meridional field curvature value and the sagittal field curvature value at a wavelength of 550 nm are controlled within the range of (-0.040 mm, 0.0 mm); the distortion diagram shows that the distortion amount at a wavelength of 550 nm is controlled within the range of (-1.50%, 0).

[0095] Based on the above composition, the present invention forms several zoom lens groups through the first zoom lens group 13 / 23, the second zoom lens group 14 / 24, the third zoom lens group 15 / 25, the fourth zoom lens group 16 / 26 with the most lenses, and the fifth zoom lens group 27; thereby, it is used to meet the zoom projection requirements of 1 < Ft / Fw < 2 and 10 < OAL / IMH < 24, and at the same time, the aberration, longitudinal spherical aberration, field curvature, and distortion of the zoom projection lenses 10 and 20 at the wide-angle end and the telephoto end can be controlled within a small range; therefore, the present invention has the effect of meeting the zoom projection requirements and taking into account the projection imaging quality.

[0096] The above description is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A zoom projection lens, characterized in that: From the magnifying side to the reducing side of the lens, it sequentially includes: a front fixed lens group, a focusing lens group, several zoom lens groups, and a rear fixed lens group, to satisfy 1 < Ft / Fw < 2 and 10 < OAL / IMH < 24, where Ft is the effective focal length at the telephoto end, Fw is the effective focal length at the wide-angle end, OAL is the distance from the first lens of the lens to the focal plane, and IMH is the semi-height of the focal plane.

2. The zoom projection lens according to claim 1, wherein: The focusing lens group includes at least one lens with a positive refractive power.

3. The zoom projection lens according to claim 1, wherein: Among the several zoom lens groups, the zoom lens group with the largest number of lenses has a positive refractive power and includes at least two lenses with a positive refractive power.

4. The zoom projection lens according to claim 1, wherein: Among the several zoom lens groups, there are two zoom lens groups, each of which includes at least one lens with a positive refractive power.

5. The zoom projection lens according to claim 1, wherein: The front fixed lens group has a positive refractive power, the focusing lens group has a negative refractive power, and the several zoom lens groups sequentially include, after the focusing lens group: a first zoom lens group with a positive refractive power, a second zoom lens group with a positive refractive power, a third zoom lens group with a negative refractive power, and a fourth zoom lens group with a positive refractive power. The rear fixed lens group has a positive refractive power.

6. The zoom projection lens according to claim 5, wherein: The fourth zoom lens group is the zoom lens group with the largest number of lenses among the several zoom lens groups.

7. The zoom projection lens according to claim 1, wherein: The front fixed lens group has a negative refractive power, the focusing lens group has a negative refractive power, and the several zoom lens groups sequentially include, after the focusing lens group: a first zoom lens group with a positive refractive power, a second zoom lens group with a positive refractive power, a third zoom lens group with a negative refractive power, a fourth zoom lens group with a positive refractive power, and a fifth zoom lens group with a positive refractive power. The rear fixed lens group has a positive refractive power.

8. The zoom projection lens according to claim 7, wherein: The fourth zoom lens group is the zoom lens group with the largest number of lenses among the several zoom lens groups.

Images