Zoom Lens With Reflective Element and Plastic Lenses

The patent replaces expensive glass mold lenses with plastic injection-molded lenses. Although plastic lenses have shorter service life compared to glass, they can be mass-produced at low cost through injection molding, making them economically viable for consumer electronics. The patent specifically uses plastic lenses with aspheric surfaces to achieve aberration correction without the high manufacturing costs of glass mold lenses.

The patent changes the material parameter from glass to plastic, which fundamentally alters the manufacturing process and cost structure. Plastic lenses can be injection molded with aspheric surfaces directly, eliminating the need for expensive glass molding processes. The patent optimizes the lens design by adjusting curvature radii, thickness, and material properties to achieve the desired optical performance with plastic material.

The patent employs a composite lens structure where a plastic lens is combined with a resin coating layer. The resin layer has different thermal expansion characteristics than the plastic substrate, creating a compensation effect that reduces the overall temperature sensitivity of the lens system. This composite structure allows the lens to maintain optical performance across a wider temperature range while retaining the cost advantages of plastic injection molding.

The patent selects specific plastic materials with optimized thermal properties and adjusts the lens design parameters (curvature, thickness, aperture) to minimize temperature-induced aberrations. By carefully controlling the material parameters and geometric parameters, the patent achieves temperature compensation without requiring active thermal management systems.

The patent transitions from correcting aberrations primarily through axial positioning (one dimension) to utilizing aspheric surface geometry (adding dimensional complexity to the lens surfaces themselves). By incorporating aspheric surfaces with specific curvature variations in the radial direction, the patent achieves superior aberration correction without increasing the axial length of the optical system, thereby maintaining compact device form factor.

The patent employs aspheric lens surfaces instead of simple spherical surfaces. The aspheric profiles provide additional degrees of freedom in controlling light ray paths, enabling effective correction of spherical aberration, coma, and other off-axis aberrations within a compact optical train. The specific aspheric coefficients are optimized to achieve the desired correction while minimizing the overall system length.

The patent systematically replaces glass lenses with plastic injection-molded lenses throughout the optical system. This substitution dramatically reduces manufacturing cost and enables mass production while accepting the trade-off of reduced service life and increased temperature sensitivity, which are managed through material selection and optical design optimization. The plastic lenses are designed to meet the specific performance requirements of mobile terminal cameras where cost and miniaturization are critical.

The patent changes the fundamental material parameter from glass to plastic, which enables injection molding manufacturing processes. This material substitution allows for integrated molding of multiple lens elements and aspheric surfaces in a single process step, reducing assembly complexity and cost. The optical design is simultaneously optimized for plastic material properties including refractive index, Abbe number, and thermal expansion characteristics.