3.12-inch LCD projection lens
By combining three spherical lenses and a graduated focal length Fresnel lens, the shortcomings of short-throw lenses in single-chip LCD projectors are solved, achieving high-definition image quality and excellent optical performance, suitable for 3.12-inch LCD projectors.
Patent Information
- Application Number
- CN202422990229.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-12-05
AI Technical Summary
Existing technologies make it difficult to effectively apply short-throw lenses in single-chip LCD projectors, especially 3.12-inch LCD projectors, resulting in insufficient high-definition image quality and optical performance.
It employs a combination of three spherical lenses of different shapes and optical properties, along with a Fresnel lens with a graduated focal length, to form a global high-definition lens with a focal length of 95mm, an f/# of 2.8, and a throw ratio of 1.25, for use in 3.12-inch LCD projectors.
It achieves high-definition 1080p image quality, TV distortion of less than 0.2%, transfer function of greater than 50%@14lp/mm, and relative illumination of greater than 72%, meeting the requirements for high-definition display.
Smart Images
Figure CN223711910U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the projection objective lens (hereinafter referred to as the lens) used for liquid crystal (LCD, the abbreviation of Liquid Crystal Display) projector. The liquid crystal projector is mainly composed of the illumination light path and the imaging device, and the LCD and the lens form the imaging assembly. The illumination light path adopts light emitting diode (LED) and other optical devices. BACKGROUND
[0002] According to the display device classification, the current projector is divided into 3LCD, LCOS, DLP and single-chip LCD, and the through type liquid crystal projector is divided into 3LCD and single-chip LCD. At present, the 3LCD liquid crystal projector has long-focus projection lens and short-focus projection lens, and the single-chip LCD liquid crystal projector is generally between 2.69~5.7 inches due to the large LCD size, so it is difficult to use the short-focus projection lens in the design of the single-chip LCD projector. The utility model implements the short-focus lens on the 3.12-inch LCD, the projection ratio is 1.25, the focal length is 95mm, F / # is 2.8, the global surface lens combination is adopted, the Fresnel lens participating in imaging together has the characteristics of gradually changing focal length, so that the TV distortion is less than 0.2%, the transmission function is greater than 50% @ 14lp / mm, the high-definition 1080p image quality requirement is reached, and the relative illumination is greater than 72%. SUMMARY
[0003] The utility model is a global surface high-definition lens combined by three pieces of lenses with different shapes and different optical properties, and is a global surface scheme large-size LCD projection lens, the focal length is 95mm, F / # is 2.8, the projection ratio is 1.25, and the shortage of the short-focus lens application in the 3.12-inch single-chip LCD liquid crystal projector on the market is made up.
[0004] The utility model is composed of three pieces of spherical lenses, and the three pieces of spherical lenses are arranged according to Figure 1L1, L2, L3 respectively refer to three pieces of spherical lenses of the utility model from left to right. The lens L1 is a convex-concave spherical lens with positive diopter, the material is LAK7A, the lens aperture is 40.00mm, the center thickness is 4.910mm, the spherical radii of curvature are 37.321mm and 88.042mm respectively, in the utility model, the face with the spherical radius of curvature of 37.321mm is on the left, and the other face is on the right; the lens L2 is a double-concave spherical lens with negative diopter, the material is F4, the lens aperture is 28.00mm, the center thickness is 1.180mm, the spherical radii of curvature are 52.085mm and 41.624mm respectively, in the utility model, the face with the spherical radius of curvature of 52.085mm is on the left, and the other face is on the right; the lens L3 is a double-convex spherical lens with positive diopter, the material is LAK7A, the lens aperture is 30.00mm, the center thickness is 5.260mm, the spherical radii of curvature are 80.305mm and 45.555mm respectively, in the utility model, the face with the spherical radius of curvature of 80.305mm is on the left, and the other face is on the right. The intervals between the three pieces of spherical lenses are 12.84mm between L1 and L2 and 2.80mm between L2 and L3 in turn. The total length of the three pieces of spherical lens combination is 26.99mm.
[0005] The three pieces of spherical lenses are fixed by plastic fasteners to form an integral whole, namely the utility model. Figure 1 As shown, the plastic fasteners for fixing the lenses fix the spherical lenses L1, L2 and L3 from left to right according to the interval distance requirements between them.
[0006] In use, a piece of 3.12-inch liquid crystal display panel with a resolution of 1920*1080 is needed as the object plane of the projection lens and is projected and imaged by the utility model.
[0007] In use, a piece of Fresnel lens with a length of 76mm and a width of 47mm and a thickness of 1.60mm is also needed, the Fresnel lens has the characteristics of variable focal length, as shown in Figure 2 The Fresnel lens is placed between the liquid crystal display panel and the three-piece spherical lens combination of the utility model, the interval between the Fresnel lens and the three-piece spherical lens combination is 69.89mm, and the interval between the Fresnel lens and the liquid crystal display panel is 11.50mm.
[0008] The spherical lens used in the utility model has low processing cost and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS
[0009] The utility model will be further described below in combination with the drawings and examples.
[0010] Figure 1This is a schematic diagram of the present invention. The three spherical lenses are fixed by plastic fasteners, and L1, L2, and L3 are the three spherical lenses. Figure 2 This diagram illustrates the positional relationship between the three spherical lens assembly of this invention and the liquid crystal display panel and Fresnel lens during specific use. From left to right: the three spherical lens assembly of this invention, the Fresnel lens, and the liquid crystal display panel. The Fresnel lens is 69.89 mm away from the three spherical lens assembly, and the Fresnel lens is 11.50 mm away from the liquid crystal display panel. Detailed Implementation
[0011] This utility model consists of three spherical lenses ( Figure 1 The structure consists of L1, L2, and L3 in sequence, and uses plastic fasteners. Figure 1 As shown, L1, L2, and L3 are fixed sequentially from left to right. L1, with a spherical radius of curvature of 37.321 mm, is on the left, and the other side is on the right. L2, with a spherical radius of curvature of 52.085 mm, is on the left, and the other side is on the right. L3, with a spherical radius of curvature of 80.305 mm, is on the left, and the other side is on the right. In use, the three spherical lenses are arranged and placed on the left side of the LCD panel. A Fresnel lens, measuring 76 mm x 47 mm and 1.60 mm thick, is placed between the LCD panel and the LCD panel. The Fresnel lens has a graduated focal length. The distance between the Fresnel lens and the LCD panel is 69.89 mm, and the distance between the Fresnel lens and the LCD panel is 11.50 mm.
Claims
1. A 3.12-inch LCD projection lens, characterized in that: The system uses a combination of three spherical lenses, with a total length of 26.99 mm. Its structure, along the optical axis from the projection plane to the image source plane, includes: a first lens (L1) with positive refractive power, a second lens (L2) with negative refractive power, and a third lens (L3) with positive refractive power, fixed together by plastic fasteners. The first lens (L1) is a convex-concave spherical lens made of LAK7A material, with a lens diameter of 40.00 mm, a center thickness of 4.910 mm, and radii of curvature of 37.321 mm and 88.042 mm, respectively. The second lens (L2) is a biconcave spherical lens made of F4 material, with a lens diameter of 28.00 mm and a center thickness of 4.910 mm. The thickness of the first lens is 1.180mm, and its spherical curvature radii are 52.085mm and 41.624mm respectively. The third lens (L3) is a biconvex spherical lens made of LAK7A with a lens diameter of 30.00mm and a center thickness of 5.260mm. Its spherical curvature radii are 80.305mm and 45.555mm respectively. The spacing between the three spherical lenses is as follows: 12.84mm between the first lens (L1) and the second lens (L2), and 2.80mm between the second lens (L2) and the third lens (L3).