Jiaqin commented on OFILM's (SZ.002456) optical lens assembly patent, which uses the first lens with positive refractive power and the second and fifth lenses with negative refractive power. In DMS, driver information can be captured accurately and in real time to ensure driving safety.
According to micronet news, OFILM entered the field of smart cars as early as 2015, with in-depth layout of autonomous driving, body electronics and instrument central control. Based on optical lenses and cameras, it has continuously enriched its product matrix layout and has already Take a place among the new forces.
With the development of the automotive industry, technologies such as ADAS and DMS have gradually matured. Among them, DMS needs to monitor the driver's head, face and other expressions and movements in real time, and provide early warning for driver fatigue and distraction. Early warning states include closing eyes, lowering head, yawning, looking left and right, smoking, talking on the phone, etc. In order for the DMS to accurately detect the driver's head, face and other expressions and movements in challenging lighting environments such as at night and backlighting, a camera device with high pixels and high resolution is urgently needed.
To this end, OFILM applied for an invention patent called "an optical lens assembly, camera module and terminal" on December 30, 2019 (application number: 201911403710.8). The applicant is Tianjin OFILM OPTOELECTRONICS LIMITED.
Figure 1 is a schematic structural diagram of the optical lens group
Figure 1 is a schematic structural diagram of the optical lens group proposed by the present invention. The imaging optical lens group includes a first lens 110, a second lens 120, The three lenses 130, the fourth lens 140 and the fifth lens 150 are arranged sequentially along the optical axis from the object plane to the image plane.
The first lens has positive refractive power, the radius of curvature of the object side is positive, the radius of curvature of the image side is negative, the focal length is f1, and the focal length of the optical lens group is f, 1 f1/f 3. The first lens is close to the object surface and is a positive lens. It can provide positive refractive power to the system and focus the incident light beam, which is conducive to the effective transmission of image information collected by the optical lens group to the image plane.
The second lens has negative refractive power, the radius of curvature of the object side is negative, the radius of curvature of the image side is positive, and the thickness at the optical axis is CT2, CT2>0.3. By reasonably limiting the position of the second lens at the optical axis, the processability of the lens can be ensured.
The third lens has positive refractive power, the radius of curvature of the object side is negative, the radius of curvature of the image side is negative, the reciprocal of the radius of curvature of the object side is cuy s5, and the optical effective diameter of the object side is map s5, the reciprocal of the radius of curvature of the image side is cuy s6, the optical effective diameter of the image side is map s6, and satisfies the following conditional expression: |(cuy s5)*(maps5)-(cuy s6)*(map s6)|/ 2>0.05. By reasonably limiting the above four data, the ease of processing of meniscus lenses can be controlled and the process capabilities of meniscus lenses can be guaranteed.
The fourth lens has positive refractive power, the radius of curvature of the object side is positive, and the radius of curvature of the image side is negative. The distance between the image side of the third lens and the object side of the fourth lens on the optical axis is d34. The maximum periphery of the optically effective area of ??the image side of the third lens and the object side of the fourth lens is at the projection point on the optical axis. The distance is Ed34, Ed34/d34 20. By reasonably limiting the above data, it is possible to control the curvature of the image side of the third lens and the object side of the fourth lens, which is beneficial to miniaturization of the system. At the same time, because the image side of the third lens and the object side of the fourth lens are both convex, it can also avoid excessive bending of the two convex surfaces while ensuring high pixels, avoid collisions during the assembly process, and improve the assembly yield.
The fifth lens has negative refractive power, the radius of curvature of the object side is negative, the radius of curvature of the image side is negative or the image side is a plane, the radius of curvature of the image side is Rs10, Rs10