Low-cost film sheet welcome lamp lens and imaging method

Abstract

The application relates to the technical field of lenses, in particular to a low-cost film welcome light lens and an imaging method. An optical system of the lens is composed of a diaphragm, a first lens and a second lens arranged in sequence from left to right along a light incident path. In the case of not considering the reverse bending caused by the aspherical coefficient, the first lens is a meniscus convex positive lens, the object side of which is a convex surface and the image side is a concave surface; the second lens is a meniscus concave negative lens, the object side of which is a concave surface and the image side is a convex surface; the first lens and the second lens are aspherical lenses. By reasonably distributing the optical power, surface type, central thickness of each lens and the axial distance between each lens, the total length of the lens and the radial size of each lens are reduced while the imaging performance of the lens is met, and the lens group is small in size and low in cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lenses, in particular to a low-cost film piece welcome light lens and imaging method. BACKGROUND

[0002] The optical system of a vehicle-mounted projection loqo light generally comprises an illumination system, a film pattern (or a transparent display screen to realize a dynamic pattern) and an imaging projection, and is basically a transplanted application of a conventional consumer projection system. The function of the welcome light is to increase the high-tech feeling of the vehicle and improve the product commodity, which is generally used in the high-end and top-end configuration of the vehicle. The commonly used welcome light scheme is a scheme using a film piece. In order to project a LOGO on the ground, the first step is to focus the light of the light source at the focal point of the LOGO; the second step is to disperse the light passing through the LOGO film, so as to achieve the effect of enlarging the LOGO.

[0003] The most widely used is a film piece of PET substrate, which uses the imaging and shooting principle of a film camera to expose and print a LOGO pattern on the film piece. The earliest welcome light of the outside rearview mirror used by Guangqi Passenger Vehicle is a certain vehicle model, which is favored by the majority of customers and greatly improves the user's experience. However, with the increasing popularity and technical innovation of the scheme, it is imperative to reduce the cost to gain the favor of the market. SUMMARY

[0004] The purpose of the present application is to provide a low-cost film piece welcome light lens and imaging method. The lens is reasonably matched with various optical lenses, so that the system structure is compact and reasonable, easy to assemble, more suitable for large-scale high-yield production, and has a lower manufacturing cost.

[0005] The technical scheme of the present application is as follows: a low-cost film piece welcome light lens, the optical system of the lens comprises, from left to right along the light incident path, an aperture, a first lens and a second lens; without considering the reverse curvature caused by the aspherical coefficient, the first lens is a meniscus convex positive lens, the object side is convex, and the image side is concave; the second lens is a meniscus concave negative lens, the object side is concave, and the image side is convex; the first lens and the second lens are aspherical lenses.

[0006] Further, the first lens and the second lens are made of plastic material.

[0007] Further, the focal length of the optical system is , and the focal lengths of the first lens and the second lens are , wherein and satisfy the following ratio: .

[0008] Further, the first lens satisfies a relationship: , ; the second lens satisfies a relationship: , wherein is a refractive index, is an Abbe number.

[0009] Further, an air gap between the first lens and the second lens is 0.5-1.0 mm.

[0010] Further, an optical total length TTL of the optical system and a focal length f of the optical system satisfy TTL / f≥1.

[0011] Further, an F number of the optical system is ≤2.8.

[0012] Further, an image height H of the optical system and the focal length f of the optical system satisfy H / f≤1.0.

[0013] Further, a stop of the optical system is a mirror surface of an object side surface of the first lens.

[0014] An imaging method of a low-cost film welcome light lens, comprising a low-cost film welcome light lens, light from the object side to the image side in turn through the stop, the first lens, the second lens, and then imaged on the imaging surface.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] 1. The lens has an imaging angle of the object greater than 20 degrees, and can project a 12 cm wide picture at 33.5 cm while ensuring that the TV Distortion is less than 1%.

[0017] 2. It has a large clear aperture and low tolerance sensitivity.

[0018] 3. By reasonably matching each optical lens, the system structure is compact and reasonable, easy to assemble, and has low tolerance sensitivity, which is more suitable for large-scale high-yield production.

[0019] 4. The all-plastic structure has low manufacturing cost and light weight, which is beneficial to the manufacturing and installation of the module.

[0020] 5. The axial color difference, sagittal color difference and high-order color difference are corrected, ensuring that the imaging system also has high imaging quality at a large angle.

[0021] 6. The advantages of aspheric lens in correcting aberration are fully utilized, which meets the requirements of high-definition imaging while having smaller lens outer diameter and shorter optical total length, ensuring the miniaturization of the lens.

[0022] 7. RI is 90% or more. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is a schematic diagram of the optical structure of the present application;

[0024] Fig. 2 is a schematic diagram of the optical structure of the present application;

[0025] Fig. 3 is a full working waveband field curvature distortion diagram of the present application;

[0026] Fig. 4 is a full working waveband MTF diagram of the present application;

[0027] In the figure: L1 - first lens; L2 - second lens; IMA - imaging plane. DETAILED DESCRIPTION

[0028] In order to make the above features and advantages of the present application more apparent, the following specific examples are described in detail below, together with the accompanying drawings, as follows, but the present application is not limited thereto.

[0029] REFERENCE Figs. 1 to 4

[0030] A low-cost film welcome light lens, the optical system of the lens is composed of a diaphragm, a first lens and a second lens arranged in sequence from left to right along the light incident path. Without considering the reverse curvature caused by the aspherical coefficient, the first lens is a meniscus convex positive lens, the object side is convex, and the image side is concave. The second lens is a meniscus concave negative lens, the object side is concave, and the image side is convex. The first lens and the second lens are both made of plastic material, the first lens is an aspherical lens, and the second lens is an aspherical lens with negative focal power, so that the lens can adjust the large-angle light while reducing the distortion of the optical system. Through reasonable lens matching, the optical system realizes wide-angle, low-distortion, low-dispersion, large-aperture design, and the on-axis and off-axis aberrations are well corrected, so that the lens has good imaging quality.

[0031] In this embodiment, the focal length of the optical system is , the focal lengths of the first lens and the second lens are , and and satisfy the following ratio: .

[0032] In this embodiment, the first lens satisfies the relationship: , ; the second lens satisfies the relationship: , , wherein is the refractive index, is the Abbe number.

[0033] In this embodiment, the air gap between the first lens and the second lens is 0.5-1.0mm.

[0034] In this embodiment, the total optical length TTL of the optical system and the focal length f of the optical system satisfy TTL / f≥1; the image height H of the optical system and the focal length f of the optical system satisfy H / f≤1.0.

[0035] In this embodiment, the optical stop of the optical system is the object side surface of the first lens.

[0036] In this embodiment, the technical index that can be achieved by the optical system of the lens is as follows:

[0037] (1) focal length: 15.0≤EFFL≤16.0mm;

[0038] (2) aperture F≤2.8;

[0039] (3) field of view angle: 2w≥20°;

[0040] (4) working waveband: visible light waveband.

[0041] In this embodiment, to achieve the above design parameters, the specific design of each lens is shown in the following table:

[0042] .

[0043] In this embodiment, the aspheric coefficients of each aspheric lens of the optical system are as follows:

[0044] .

[0045] An imaging method of a low-cost film welcome light lens, comprising a low-cost film welcome light lens, light rays from left to right from the object side to the image side pass through the optical stop, the first lens, the second lens in turn and then form an image on the imaging surface.

[0046] The optical system reasonably allocates the optical power, surface type, central thickness of each lens and the axial distance between each lens, etc., so as to meet the imaging performance requirements of the lens, reduce the total length of the lens and the radial size of each lens, and achieve small size and low cost of the lens group.

[0047] The above merely describes the preferred embodiments of the present application, and for those skilled in the art, no creative labor is needed to design low-cost film welcome lamp lenses and imaging methods in different forms according to the teaching of the present application, and any equivalent changes, modifications, replacements and variations made within the scope of the present application should be included in the scope of the present application.

Claims

1. A low cost film welcome light lens characterized in that, The optical system of the lens is composed of a diaphragm, a first lens and a second lens arranged in sequence from left to right along the light incident path; without considering the reverse bending caused by the aspherical coefficient, the first lens is a meniscus convex positive lens, the object side surface of which is convex and the image side surface of which is concave; the second lens is a meniscus concave negative lens, the object side surface of which is concave and the image side surface of which is convex; the first lens and the second lens are aspherical lenses; the focal length of the optical system is , the focal lengths of the first lens and the second lens are respectively , wherein and satisfy the following ratio: ; the first lens satisfies the relationship: , ; the second lens satisfies the relationship: , , wherein is the refractive index, is the Abbe constant; the air gap between the first lens and the second lens is 0.5-1.0 mm; the optical total length TTL of the optical system and the focal length f of the optical system satisfy TTL / f≥1; the F number of the optical system is ≤2.8; the image height H of the optical system and the focal length f of the optical system satisfy H / f≤1.

0.

2. A low cost film welcome light lens according to claim 1, characterized in that, The first lens and the second lens are made of plastic material.

3. A low cost film welcome light lens according to claim 1, characterized in that, The stop of the optical system is a mirror surface on the object side of the first lens.

4. A low-cost method of imaging a film welcome light lens, comprising a low-cost film welcome light lens according to claim 1, 2 or 3, characterized in that, Light rays pass through the stop, the first lens and the second lens in sequence from the object side to the image side, and then form an image on the imaging surface.

Images