Retrofocus Optical Layout for Wide-FOV Peripheral Light Capture
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Solution Overview
Problem
Optical systems with a wide field of view experience peripheral light falloff due to the cosine fourth law, and resin lenses, while lightweight, require temperature compensation for use in measurement devices like LIDAR devices that operate across varying temperatures.
Innovation Solution
An optical system with a retrofocus configuration, comprising a front group with negative power and a rear group with positive power, using resin lenses for the front and rear groups with specific aspherical surfaces and glass lenses for temperature compensation, achieving negative distortion aberration to enhance peripheral light reception and temperature stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a wide field of view is achieved in an optical system, then the field of view is improved, but peripheral light falloff occurs according to the cosine fourth law
Solution Approach 1:
The patent applies parameter changes by introducing negative distortion aberration as a key optical parameter. Specifically, the optical system is designed to have negative distortion aberration of 5% or more, which compensates for the cosine fourth law effect and increases peripheral light amounts. This parameter change allows the system to maintain wide field of view while improving peripheral illumination intensity.
Solution Approach 2:
The patent utilizes curved surfaces in the lens design, particularly aspherical surfaces, to control distortion aberration. The front-group second lens includes an aspherical surface, and the lens configurations are designed to generate negative distortion aberration, which helps correct the peripheral light falloff issue while maintaining a wide field of view.
2Weight of moving object
If resin lenses are used to achieve weight reduction, then the weight is reduced, but temperature compensation becomes necessary for maintaining performance across wide temperature ranges
Solution Approach 1:
The patent employs composite materials by combining resin lenses and glass lenses in a single optical system. The resin lenses provide weight reduction, while the glass lenses (specifically the rear-group first lens with positive power) provide temperature compensation. This composite approach allows the system to achieve both weight reduction and temperature stability simultaneously.
Solution Approach 2:
The patent uses parameter changes in the lens configuration, specifically designing the rear-group first lens with positive power made of glass to compensate for temperature-induced parameter changes in the resin lenses. This ensures that the overall optical performance remains stable across wide temperature ranges while maintaining the weight benefits of resin lenses.
3Weight of moving object
If resin lenses are used in measurement devices mounted on vehicles, then weight is reduced, but temperature compensation is required to maintain performance across wide temperature ranges
Solution Approach 1:
The patent uses composite materials by combining resin and glass lenses to create an optical system that is both lightweight and temperature-stable. The resin lenses reduce weight, while the glass lens component ensures adaptability across wide temperature ranges, making the device suitable for vehicular applications.
Solution Approach 2:
The patent applies local quality by using different materials (resin vs. glass) in different parts of the optical system based on their specific functions. Resin lenses are used where weight reduction is critical, while glass lenses are used where temperature compensation is needed, optimizing each component for its specific role in the overall system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system increases peripheral light reception and maintains performance across a wide temperature range, suppressing peripheral light falloff and achieving weight reduction by combining resin and glass lenses for temperature compensation.
Implementation Method 1
a front-group first lens disposed on the object side and being constituted by a resin lens having negative power; and a front-group second lens disposed closest to the stop position and being constituted by a resin lens, a sensor-side surface thereof having an aspherical surface
Implementation Method 2
a front-group second lens disposed closest to the stop position and being constituted by a resin lens, a sensor-side surface thereof having an aspherical surface
Data Source
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AI summary
An optical system according to the present disclosure includes: a front group disposed on an object side and having negative power as a whole; and a rear group disposed further toward a sensor side than a stop position and having positive power as a whole, wherein the optical system has negative distortion aberration as a whole. The front group includes: a front-group first lens disposed on the object side and being constituted by a resin lens having negative power; and a front-group second lens disposed closest to the stop position and being constituted by a resin lens, a sensor-side surface thereof having an aspherical surface. The rear group includes: a rear-group first lens disposed closest to the stop position and being constituted by a glass lens having positive power; and a rear-group second lens disposed closest to the sensor and being constituted by a resin lens having positive power. An object-side surface of the front-group second lens is concave, and the sensor-side surface thereof is convex.