Search

CN-119165619-B - Projection lens

CN119165619BCN 119165619 BCN119165619 BCN 119165619BCN-119165619-B

Abstract

The invention provides a projection lens, which sequentially comprises a first lens with positive focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with positive focal power, a fifth lens with positive focal power and a fifth lens with positive focal power from a projection surface to an image source surface, wherein the projection side surface of the first lens is concave, the image source side surface of the first lens is convex, the second lens with positive focal power is a meniscus lens, the projection side surface of the third lens with negative focal power and the image source side surface of the third lens are concave, the projection side surface of the fourth lens with positive focal power and the image source side surface of the fourth lens are convex, and the image source side surface of the fifth lens with positive focal power is convex, wherein the curvature radius R1 of the projection side surface of the first lens and the curvature radius R2 of the image source side surface of the first lens meet the condition that 2.4< (R1+R2)/(R1-R2) <6.1. The invention improves the imaging quality of the projection lens, reduces the aberration and improves the projection quality of the projection lens through reasonable configuration of the surface type of each lens and reasonable collocation of the focal power.

Inventors

  • Liang Liufeng
  • BAO YUMIN

Assignees

  • 江西联创电子有限公司

Dates

Publication Date
20260512
Application Date
20240927

Claims (10)

  1. 1. A projection lens comprises five lenses in total, and is characterized by comprising, in order from a projection surface to an image source surface along an optical axis: a first lens having positive power, a projection side surface of which is concave, and an image source side surface of which is convex; a second lens having positive optical power, the second lens being a meniscus lens; A third lens having negative optical power, the projection side surface and the image source side surface of which are both concave; A fourth lens having positive optical power, the projection side surface and the image source side surface of which are both convex; a fifth lens having positive optical power, the image source side surface of which is convex; Wherein the radius of curvature R1 of the projection side surface of the first lens and the radius of curvature R2 of the image source side surface of the first lens satisfy 2.4< (R1+R2)/(R1-R2) <6.1; the maximum field angle FOV of the projection lens and the aperture value Fno of the projection lens satisfy 19 ° < FOV/Fno <27 °.
  2. 2. The projection lens of claim 1, wherein the chief ray incidence angle CRA at the maximum image height of the projection lens satisfies 5.1 ° < CRA <7 °, and the back focal length BFL of the projection lens and the total optical length TTL of the projection lens satisfy 0.35< BFL/TTL <0.6.
  3. 3. The projection lens according to claim 1, wherein a projection side surface curvature radius R1 of the first lens and an image source side surface curvature radius R2 of the first lens satisfy 2.68< (R1+R2)/(R1-R2) <5.6; The maximum field angle FOV of the projection lens and the aperture value Fno of the projection lens satisfy 21.46 ° < FOV/Fno <24.21 °.
  4. 4. The projection lens of claim 1, wherein the effective focal length f of the projection lens and the real image height IH corresponding to the maximum field angle of the projection lens satisfy 0.38< IH// f <0.55.
  5. 5. The projection lens of claim 1, wherein the real image height IH corresponding to the maximum field angle of the projection lens and the radian θ of the maximum half field angle of the projection lens satisfy 29mm/rad < (IH/2)/θ <42mm/rad.
  6. 6. The projection lens of claim 1, wherein the focal length f2 of the second lens and the effective focal length f of the projection lens satisfy 4.5< f2/f <9.6, and the focal length f3 of the third lens and the effective focal length f of the projection lens satisfy-1.2 < f3/f < -0.8.
  7. 7. The projection lens of claim 1, wherein the radius of curvature R10 of the image source side surface of the fifth lens and the effective focal length f of the projection lens satisfy-3.8 < R10/f < -1.1.
  8. 8. The projection lens of claim 1, wherein a focal length f1 of the first lens and a projection side surface curvature radius R1 of the first lens satisfy-1 < R1/f1< -0.1, and an image source side surface curvature radius R2 of the first lens and a focal length f1 of the first lens satisfy-0.5 < R2/f1< -0.1.
  9. 9. The projection lens of claim 1, wherein a focal length f5 of the fifth lens and a curvature radius R10 of an image source side surface of the fifth lens satisfy-2.6 < R10/f5< -0.4, and an image source side surface light passing half-caliber d10 of the fifth lens and an image source side surface light passing half-caliber sagittal height Sag10 of the fifth lens satisfy-0.35 < Sag10/d10< -0.05.
  10. 10. The projection lens of claim 1, wherein the projection side surface light-transmitting half-aperture d1 of the first lens and the projection side surface light-transmitting half-aperture sagittal height Sag1 of the first lens satisfy-0.3 < Sag1/d1< -0.05, and the image source side surface light-transmitting half-aperture d2 of the first lens and the image source side surface light-transmitting half-aperture sagittal height Sag2 of the first lens satisfy-0.3 < Sag2/d2< -0.15.

Description

Projection lens Technical Field The present disclosure relates to imaging lenses, and particularly to a projection lens. Background With the continuous increase of driving experience demands of people, the functions of the vehicle headlight are gradually changed from single illumination to multifunctional application. The traditional intelligent headlight is generally of ten-thousand-level pixels and has higher precision, but relatively speaking, the light beam control capability is slightly low, and extremely fine area illumination can not be realized like a megapixel car light. Millions of pixel car lights can support more complicated intelligent lighting functions, for example, functions such as holiday blessing and weather can be projected in a static state, and multiple functions such as curve light blanket lighting, car distance prompting, narrow road width, lane changing prompting, lane safety guidance and pedestrians can be realized in a dynamic state, so that driving experience of a driver can be effectively improved, and more consumers pay attention to the functions. The projection principle of the intelligent headlight of the vehicle is similar to that of the traditional optical projection, and the intelligent headlight of the vehicle is realized by reflection and virtual imaging based on the optical imaging technology. The vehicle-mounted system drives the projector to generate an image according to the real-time information, the image is reflected by the reflecting mirror and focused on the projection lens, and finally the image is accurately projected to a road or an environment. The existing lens has the problems of low pixels, low imaging quality and the like. Disclosure of Invention In view of the foregoing, an object of the present invention is to provide a projection lens with high imaging quality. The invention provides a projection lens, which comprises five lenses in sequence from a projection surface to an image source surface along an optical axis: a first lens having positive power, a projection side surface of which is concave, and an image source side surface of which is convex; a second lens having positive optical power, the second lens being a meniscus lens; A third lens having negative optical power, the projection side surface and the image source side surface of which are both concave; A fourth lens having positive optical power, the projection side surface and the image source side surface of which are both convex; a fifth lens having positive optical power, the image source side surface of which is convex; Wherein the radius of curvature R1 of the projection side surface of the first lens and the radius of curvature R2 of the image source side surface of the first lens satisfy 2.4< (R1+R2)/(R1-R2) <6.1. Further preferably, the incidence angle CRA of the chief ray at the maximum image height of the projection lens satisfies 5.1 DEG < CRA <7 DEG, and the back focal length BFL of the projection lens and the total optical length TTL of the projection lens satisfy 0.35< BFL/TTL <0.6. Further preferably, the maximum field angle FOV of the projection lens and the aperture value FNo of the projection lens satisfy 19 DEG < FOV/FNo <27 deg. Further preferably, the effective focal length f of the projection lens and the real image height IH corresponding to the maximum field angle of the projection lens satisfy 0.38< IH// f <0.55. Further preferably, the radian θ of the real image height IH corresponding to the maximum field angle of the projection lens and the maximum half field angle of the projection lens satisfies 29mm/rad < (IH/2)/θ <42mm/rad. Further preferably, the focal length f2 of the second lens and the effective focal length f of the projection lens satisfy 4.5< f2/f <9.6, and the focal length f3 of the third lens and the effective focal length f of the projection lens satisfy-1.2 < f3/f < -0.8. Further preferably, the radius of curvature R10 of the image source side surface of the fifth lens and the effective focal length f of the projection lens satisfy-3.8 < R10/f < -1.1. Further preferably, the focal length f1 of the first lens and the radius R1 of curvature of the projection side surface of the first lens satisfy-1 < R1/f1< -0.1, and the radius R2 of curvature of the image source side surface of the first lens and the focal length f1 of the first lens satisfy-0.5 < R2/f1< -0.1. Further preferably, the focal length f5 of the fifth lens and the curvature radius R10 of the image source side surface of the fifth lens meet the condition that-2.6 < R10/f5< -0.4, and the image source side surface light transmission half-caliber d10 of the fifth lens and the image source side surface light transmission half-caliber Sag10 of the fifth lens meet the condition that-0.35 < Sag10/d10< -0.05. Further preferably, the projection side surface light-transmitting half-aperture d1 of the first lens and the projection side surface light-transmitting half-aperture Sag1 of the first lens s