3.12-inch LCD projection lens
By using a combination of three spherical lenses and Fresnel lenses, the problem of difficulty in designing short-focus lenses for a single-chip LCD projector is solved, and the effect of high-definition 1080p image quality and high relative illumination is achieved.
Patent Information
- Application Number
- CN202411775828.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-05
- Publication Date
- 2025-01-10
AI Technical Summary
Due to the large LCD size of a single-chip LCD projector, it is difficult to design a short-focus projection lens, and cannot meet the high-definition 1080p image quality requirements.
A global high-definition lens consisting of three spherical lenses of different shapes and optical properties, combined with Fresnel lenses, achieves gradient focal length, 95mm, F/# is 2.8, and a projection ratio of 1.25, suitable for 3.12-inch single LCD LCD projector.
The TV distortion is less than 0.2%, the message is greater than 50% @ 14lp/mm, which meets the high-definition 1080p image quality requirements, and improves the relative illumination by more than 72%.
Smart Images
Figure CN119291890A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a projection lens (hereinafter referred to as lens) used in a liquid crystal (LCD, short for Liquid Crystal Display) projector. The liquid crystal projector is mainly composed of an illumination light path and an imaging device, and the LCD and the lens form an imaging component. The illumination light path is composed of a light emitting diode (LED) and other optical devices. Background Art
[0002] According to the display device classification, the current projectors are divided into 3LCD, LCOS, DLP, and single-chip LCD, and the through-type liquid crystal projectors are divided into 3LCD and single-chip LCD. At present, 3LCD liquid crystal projectors have long-focus projection lenses and short-focus projection lenses, and single-chip LCD liquid crystal projectors have a large LCD size, generally between 2.69 and 5.7 inches, so it is difficult to use short-focus projection lenses in the design of single-chip LCD projectors. The present invention invents and implements a short-focus lens on a 3.12-inch LCD, with a projection ratio of 1.25, a focal length of 95mm, F / #2.8, and a full-spherical lens combination. The Fresnel lens that participates in the imaging together has the characteristic of a gradual focal length, so that the TV distortion is less than 0.2%, the transfer function is greater than 50%@14lp / mm, and the high-definition 1080p image quality requirements are met, and the relative illumination is greater than 72%. Summary of the invention
[0003] The present invention is a spherical high-definition lens composed of three lenses of different shapes and different optical properties. It is a large-size LCD projection lens with a spherical solution. Its focal length is 95mm, F / # is 2.8, and the projection ratio is 1.25, which makes up for the lack of short-focus lens application in 3.12-inch single-chip LCD projectors on the market.
[0004] The present invention is composed of three spherical lenses. Figure 1L1, L2, and L3 shown in the figure refer to three spherical lenses of the present invention from left to right. Lens L1 is a convex-concave spherical lens with positive refractive power, made of LAK7A, with a lens diameter of 40.00mm and a center thickness of 4.910mm. Its spherical curvature radii are 37.321mm and 88.042mm respectively. In the present invention, the surface with a spherical curvature radius of 37.321mm is on the left, and the other surface is on the right; Lens L2 is a double concave spherical lens with negative refractive power, made of F4, with a lens diameter of 28.00mm and a center thickness of 1.180mm. Its spherical curvature is The radii are 52.085mm and 41.624mm respectively. In the present invention, the surface with a spherical curvature radius of 52.085mm is on the left, and the other surface is on the right; Lens L3 is a double convex spherical lens with positive refractive power, 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. In the present invention, the surface with a spherical curvature radius of 80.305mm is on the left, and the other surface is on the right. The intervals between the three spherical lenses of the present invention are: 12.84mm between L1 and L2, and 2.80mm between L2 and L3. The total length of the three spherical lenses combined is 26.99mm.
[0005] Three spherical lenses are fixed by plastic fasteners to form a whole, namely the present invention. Figure 1 As shown, the plastic fasteners for fixing the lenses fix the spherical lenses L1, L2, and L3 in sequence from left to right according to the spacing distance requirements between them.
[0006] When the present invention is used, a 3.12-inch liquid crystal display panel with a resolution of 1920*1080 is used as the object surface of the projection lens to project an image through the present invention.
[0007] When the present invention is used, a Fresnel lens with a length and width of 76mm*47mm and a thickness of 1.60mm is also required. The Fresnel lens has the characteristic of gradual focal length. Figure 2 As shown, it is placed between the liquid crystal display panel and the three-piece spherical lens combination of the present invention, the distance between the Fresnel lens and the three-piece spherical lens combination is 69.89 mm, and the distance between the Fresnel lens and the liquid crystal display panel is 11.50 mm.
[0008] The spherical lens used in the composition of the present invention has low processing cost and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is further described below in conjunction with the accompanying drawings and embodiments.
[0010] Figure 1It is a schematic diagram of the present invention. Three spherical lenses are fixed by plastic fasteners, and L1, L2, and L3 are three spherical lenses. Figure 2 The figure shows the positional relationship between the three-piece spherical lens combination of the present invention and the liquid crystal display panel and the Fresnel lens when used. From left to right, they are: the three-piece spherical lens combination of the present invention, the Fresnel lens and the liquid crystal display panel. The interval between the Fresnel lens and the three-piece spherical lens combination is 69.89 mm, and the interval between the Fresnel lens and the liquid crystal display panel is 11.50 mm. DETAILED DESCRIPTION
[0011] The present invention comprises three spherical lenses ( Figure 1 L1, L2, L3) in sequence, using plastic fasteners to press Figure 1 As shown, L1, L2, and L3 are fixed from left to right in sequence, with the surface of L1 having a spherical curvature radius of 37.321 mm on the left and the other surface on the right, the surface of L2 having a spherical curvature radius of 52.085 mm on the left and the other surface on the right, and the surface of L3 having a spherical curvature radius of 80.305 mm on the left and the other surface on the right. When the present invention is used, the three spherical lenses are combined and placed on the left side of the liquid crystal display panel, and a Fresnel lens is placed between the present invention and the liquid crystal display panel. The Fresnel lens has a specification of 76 mm*47 mm, a thickness of 1.60 mm, and a focal length of a gradual focal length. The Fresnel lens is spaced 69.89 mm from the present invention, and the Fresnel lens is spaced 11.50 mm from the liquid crystal display panel.
Claims
1. A 3.12-inch LCD projection lens, characterized in that: A combination of three spherical lenses is used, with a total length of 26.99 mm.
2. According to the spherical lens assembly of claim 1, the feature of lens 1 is that it is a convex-concave spherical lens with positive refractive power, made of LAK7A, with a lens diameter of 40.00 mm, a center thickness of 4.910 mm, and spherical curvature radii of 37.321 mm and 88.042 mm respectively.
3. According to the spherical lens assembly of claim 1, the lens 2 is characterized in that it is a double concave spherical lens with negative refractive power, made of F4, with a lens diameter of 28.00 mm, a center thickness of 1.180 mm, and a spherical curvature radius of 52.085 mm and 41.624 mm respectively.
4. According to the spherical lens assembly of claim 1, the lens 3 is characterized in that it is a biconvex spherical lens with positive refractive power, made of LAK7A, with a lens diameter of 30.00 mm, a center thickness of 5.260 mm, and a spherical curvature radius of 80.305 mm and 45.555 mm respectively.
5. The spherical lens assembly according to claim 1, wherein the intervals between the three spherical lenses are: the interval between lens 1 and lens 2 is 12.84 mm, and the interval between lens 2 and lens 3 is 2.80 mm.