Four-Element Aspheric Lens Assembly for Compact Camera Modules

The patent divides the lens system into four distinct lens elements with specific refractive powers and surface curvatures. This segmentation allows each element to contribute differently to the overall optical performance, enabling high image quality in a compact configuration where a three-element structure would fail.

The patent employs aspheric surfaces on the fourth lens element (and potentially other elements) to correct optical aberrations more effectively than spherical surfaces. This curvature variation enables better image quality control within the constrained total optical track length.

The patent specifies precise parameter ranges for each lens element including refractive power, radius of curvature, and thickness. By optimizing these parameters (e.g., R1, R2, R3, R4 relationships and SL/TTL ratio), the design achieves high image quality while maintaining a compact total optical track length, avoiding the longer track length associated with conventional glass doublet structures.

The patent combines lens elements with different refractive powers and materials properties to create a composite optical system. The fourth lens element with aspheric surfaces complements the earlier elements to achieve aberration correction in a compact form factor.

The patent uses aspheric surfaces on the fourth lens element to correct optical aberrations that spherical surfaces cannot address. This allows the use of plastic or easier-to-manufacture materials while achieving the same optical performance, simplifying the manufacturing process compared to precision glass doublet fabrication.

By specifying optimized parameter ranges for lens curvatures and thicknesses, the patent enables manufacturing processes to produce high-quality lenses more easily, reducing the difficulty associated with creating precision glass doublet lenses.