According to the micro-grid news, Shenzhen O-Film Tech Co. (lt) entered the field of smart cars as early as 20 15, with deep layout in autonomous driving, body electronics, instrument control and other aspects, constantly enriching the product matrix layout based on optical lenses and cameras, and has occupied a place among the new forces.
With the development of the vehicle 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 give early warning of the driver's fatigue and distracted state, including closing his eyes, bowing his head, yawning, looking around, smoking, making phone calls and so on. In order to enable DMS to accurately monitor the driver's head, face and other expressions and actions in challenging lighting environments such as night and backlight, a high-pixel and high-resolution camera equipment is urgently needed.
Therefore, on February 30th, 20 19, 19, Shenzhen O-film Tech Co.,lt applied for an invention patent (application number: 2019110.8), which was named "I".
Figure 1 Schematic diagram of optical lens group structure
Fig. 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 1 10, a second lens 120, a third lens 130, a fourth lens 140 and a fifth lens 150. Five lenses are arranged from the object plane along the optical axis.
The first lens has positive refractive power, its object side radius of curvature is positive, its image side radius of curvature is negative, its focal length is f 1, and the focal length of the optical lens group is F 1F 1/F3. The first lens is close to the object surface and is a positive lens, which can provide positive refractive power for the system and focus the incident beam, which is beneficial to the effective transmission of image information collected by the optical lens group to the image surface.
The second lens has negative refractive power, its object side curvature radius is negative, its image side curvature radius is positive, and the thickness at the optical axis is CT2, CT2 >；; 0.3。 By reasonably limiting the second lens on the optical axis, the machinability of the lens can be ensured.
The third lens has positive refractive power, negative object-side radius of curvature, negative image-side radius of curvature, the reciprocal of object-side radius of curvature is cuy s5, the object-side optical effective diameter is map s5, the reciprocal of image-side radius of curvature is cuy s6, and the image-side optical effective diameter is map s6, which satisfies the following conditional expressions: | (CuYS5) * (MapS5) * (Map 0 .05).
The fourth lens has a positive refractive power, with a positive radius of curvature on the object side and a negative radius of curvature on the image side. The distance between the image side of the third lens and the object side of the fourth lens on the optical axis is d34, and the distance between the projection point of the maximum circumference of the optical effective area of the image side of the third lens on the optical axis and the object side of the fourth lens is Ed34, Ed34/d34 20. By reasonably limiting the above data, the curvature of the image side of the third lens and the object side of the fourth lens can be controlled, which is beneficial to the miniaturization of the system. At the same time, because the image side surface of the third lens and the object side surface of the fourth lens are convex, the two convex surfaces can be prevented from being excessively bent on the premise of ensuring high pixels, and collision in the assembly process can be avoided, thereby improving the assembly yield.
The fifth lens has negative refractive power, its object side curvature radius is negative, its image side curvature radius is negative or its image side is flat, and its image side curvature radius is Rs 10 and Rs 10.