Projector attachment wide-angle magnification lens

Abstract

The application provides a projector additional wide-angle magnifying lens, which comprises a first lens, a second lens, a third lens and a fourth lens in sequence from an object side; the first lens is a meniscus negative lens and comprises a first convex spherical surface and a second concave spherical surface; the second lens is a double-convex positive lens and comprises a third convex spherical surface and a fourth convex spherical surface; the third lens is a double-concave negative lens and comprises a fifth concave spherical surface and a sixth concave spherical surface; and the fourth lens is a double-convex positive lens and comprises a seventh convex spherical surface and an eighth convex spherical surface. The lens uses a large amount of abnormal dispersion optical glass and super-low dispersion optical glass and has super-high optical performance.

Description

Technical Field

[0001] This invention belongs to the field of digital projection technology, specifically relating to a wide-angle magnifying lens for a projector. Background Technology

[0002] Most home projectors use medium to long telephoto lenses, which can only project an 80-100 inch image in most home environments. With rapid economic development and technological advancements, the ultra-large screen effect of home theaters is attracting people who aspire to a better life. Therefore, the addition of wide-angle magnifying lenses to projectors has become a hot research topic. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a projector-attached wide-angle magnifying lens.

[0004] The projector-attached wide-angle magnifying lens provided by the present invention includes, in sequence from the object side, a first lens, a second lens, a third lens, and a fourth lens. The first lens is a meniscus negative lens, including a first convex spherical surface and a second concave spherical surface. The second lens is a biconvex positive lens, including a third convex spherical surface and a fourth convex spherical surface. The third lens is a biconcave negative lens, including a fifth concave spherical surface and a sixth concave spherical surface. The fourth lens is a biconvex positive lens, including a seventh convex spherical surface and an eighth convex spherical surface.

[0005] Preferably, the first lens, the second lens, the third lens, and the fourth lens are all made of glass.

[0006] Further preferably, the refractive index of the first lens is greater than 1.45 and less than 1.55, and the dispersion is greater than 70 and less than 93.

[0007] The refractive index of the second lens is greater than 1.70 and less than 1.79, and the dispersion is greater than 20 and less than 29.

[0008] The refractive index of the third lens is greater than 1.85 and less than 1.92, and the dispersion is greater than 20 and less than 33.

[0009] The fourth lens has a refractive index greater than 1.45 and less than 1.55, and a dispersion greater than 60 and less than 75.

[0010] Further preferably, the material of the first lens is HFK61-CDGM, with a refractive index of 1.4970 and a dispersion of 81.6;

[0011] The second lens is made of Japanese HOYA FF8, with a refractive index of 1.75 and a dispersion of 25.2.

[0012] The material of the third lens is H-ZLAF75A-CDGM, with a refractive index of 1.904 and a dispersion of 31.3.

[0013] The fourth lens is made of HQK3L-CDGM material, with a refractive index of 1.487 and a dispersion of 70.4.

[0014] Further preferred, the parameters of the lens are as follows:

[0015]

[0016] Compared with the prior art, the advantages of the present invention are that all lenses adopt a spherical design to correct various aberrations, and all are made of glass, which improves the quality of the lenses and the sharpness of the lens, thereby improving the performance of the lens. Attached Figure Description

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 A schematic diagram of the structure of the projector with an attached wide-angle magnifying lens provided by the present invention;

[0019] Figure 2 MTF diagram of a projector with an attached wide-angle magnifying lens provided by the present invention;

[0020] Figure 3 Field curvature diagram of a projector with an attached wide-angle magnifying lens provided by the present invention;

[0021] Figure 4 Optical distortion diagram of a projector with an attached wide-angle magnifying lens provided by the present invention;

[0022] Figure 5 The relative illumination diagram for the projector with an attached wide-angle magnifying lens provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0024] This invention provides a projector with an attached wide-angle magnifying lens, such as... Figure 1 As shown, the object side sequentially includes a first lens, a second lens, a third lens, and a fourth lens. The first lens is a meniscus negative lens, including a first convex spherical surface and a second concave spherical surface. The second lens is a biconvex positive lens, including a third convex spherical surface and a fourth convex spherical surface. The third lens is a biconcave negative lens, including a fifth concave spherical surface and a sixth concave spherical surface. The fourth lens is a biconvex positive lens, including a seventh convex spherical surface and an eighth convex spherical surface.

[0025] To improve the quality of the lens itself, as an improvement to the technical solution, the first lens, the second lens, the third lens, and the fourth lens are provided.

[0026] As an improvement to the technical solution, the refractive index of the first lens is greater than 1.45 and less than 1.55, and the dispersion is greater than 70 and less than 93; the preferred material for the first lens is HFK61-CDGM, which has a refractive index of 1.4970 and a dispersion of 81.6.

[0027] The refractive index of the second lens is greater than 1.70 and less than 1.79, and the dispersion is greater than 20 and less than 29. The preferred material for the second lens is Japanese HOYA FF8, which has a refractive index of 1.75 and a dispersion of 25.2.

[0028] The third lens has a refractive index greater than 1.85 and less than 1.92, and a dispersion greater than 20 and less than 33; the preferred material for the third lens is H-ZLAF75A-CDGM, with a refractive index of 1.904 and a dispersion of 31.3.

[0029] The fourth lens has a refractive index greater than 1.45 and less than 1.55, and a dispersion greater than 60 and less than 75. The preferred material for the fourth lens is HQK3L-CDGM, with a refractive index of 1.487 and a dispersion of 70.4.

[0030] As an improvement to the technical solution, the parameters of the lens are as follows:

[0031]

[0032] Figure 2 This is the modulation transfer function (MTF) of this lens under ideal master lens conditions. It exhibits near-continuous diffraction at 60 line pairs, demonstrating excellent performance.

[0033] like Figures 3 to 5 As shown, the projector's wide-angle magnifying lens exhibits meridional and sagittal field curvatures greater than -0.04mm and less than 0.09mm, respectively, and optical distortion greater than -2.5% and less than +0.2%, all meeting imaging performance requirements. Its edge relative illumination reaches 73%. Compared to existing technologies, the lens is entirely made of glass, improving the lens's inherent quality and sharpness, thus enhancing its overall performance.

Claims

1. A wide-angle magnifying lens for a projector, characterized in that: The projector's additional wide-angle magnifying lens has a total of four lenses, which, from the object side, include a first lens, a second lens, a third lens, and a fourth lens. The first lens is a meniscus negative lens, including a first convex spherical surface and a second concave spherical surface. The second lens is a biconvex positive lens, including a third convex spherical surface and a fourth convex spherical surface. The third lens is a biconcave negative lens, including a fifth concave spherical surface and a sixth concave spherical surface. The fourth lens is a biconvex positive lens, including a seventh convex spherical surface and an eighth convex spherical surface. All four lenses are made of glass. The first lens has a refractive index greater than 1.45 and less than 1.55, and a dispersion greater than 70 and less than 93. The refractive index of the second lens is greater than 1.70 and less than 1.79, and the dispersion is greater than 20 and less than 29. The refractive index of the third lens is greater than 1.85 and less than 1.92, and the dispersion is greater than 20 and less than 33. The fourth lens has a refractive index greater than 1.45 and less than 1.55, and a dispersion greater than 60 and less than 75.

2. The projector with an attached wide-angle magnifying lens according to claim 1, characterized in that: The first lens is made of HFK61-CDGM, with a refractive index of 1.4970 and a dispersion of 81.

6. The second lens is made of Japanese HOYA FF8, with a refractive index of 1.75 and a dispersion of 25.

2. The material of the third lens is H-ZLAF75A-CDGM, with a refractive index of 1.904 and a dispersion of 31.

3. The fourth lens is made of HQK3L-CDGM material, with a refractive index of 1.487 and a dispersion of 70.

4.

3. The projector with an attached wide-angle magnifying lens according to claim 1, characterized in that: The parameters of the lens are as follows: 。

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