Electro-optic Aperture for Thin Camera Modules
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Solution Overview
Problem
Conventional variable apertures in consumer electronics devices, such as smartphones and tablets, are complex, prone to physical shock, and require additional z-height, making them unsuitable for thin-profile devices.
Innovation Solution
An electro-optic variable aperture using an active electro-chromic medium with a stack of transparent conductor layers and an electrolyte medium, controlled by a driver circuit to adjust light transmission, allowing for a continuously variable or discrete adjustment of the aperture size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional variable apertures using leaflets are used, then aperture control function is achieved, but device complexity increases and reliability decreases
Solution Approach 1:
The patent replaces the mechanical leaflet-based aperture system with an electro-optic aperture that uses electric fields to control light transmission. The electro-optic medium changes its optical properties (absorption coefficient) in response to applied voltage, eliminating the need for moving mechanical parts while achieving the same aperture control function.
Solution Approach 2:
The patent changes the optical parameter (transmission coefficient) of the aperture medium by applying different voltages. By varying the voltage applied to the electro-optic medium, the absorption coefficient changes, thereby controlling the amount of light transmitted through the aperture without any mechanical movement.
2Adaptability or versatility
If conventional variable apertures using leaflets are used, then aperture control function is achieved, but device reliability decreases due to physical shock susceptibility
Solution Approach 1:
The patent eliminates mechanical components by using an electro-optic medium that controls light transmission through electric field effects. Since there are no moving parts, the aperture is inherently resistant to physical shock and damage, significantly improving reliability in portable devices.
3Adaptability or versatility
If conventional variable apertures using leaflets are used, then aperture control function is achieved, but device thickness increases
Solution Approach 1:
The patent replaces the bulky mechanical leaflet structure with a thin electro-optic medium layer sandwiched between transparent electrodes. This electro-optic aperture can be integrated into the existing optical path without requiring additional z-height space, thereby reducing overall device thickness.
Solution Approach 2:
The patent uses a thin electro-optic medium layer (electrochromic or liquid crystal material) as the aperture control element. This thin film structure allows the aperture to be integrated within the existing optical path without adding significant thickness to the device.
4Length of stationary object
If electro-optic aperture with EC medium is used, then device thickness and complexity are reduced, but light transmission control capability must be maintained
Solution Approach 1:
The patent controls the light transmission parameter by changing the voltage applied to the electro-optic medium. By varying the voltage, the absorption coefficient of the medium changes, enabling continuous control of light transmission from fully transparent to fully opaque states, thereby maintaining full aperture control capability.
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
Enables flexible fine-tuning of exposure settings in camera modules, reducing device thickness and complexity while maintaining image quality, by varying the aperture size to control light transmission effectively.
Implementation Method 1
The electro-optic aperture may include an electro-chromic (EC) medium that attenuates light from the scene that is passing through the aperture, in response to a voltage being applied to a pair of transparent conductor layers between which the EC medium is sandwiched
Data Source
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AI summary
An electro-optic aperture has a stack that includes a front transparent conductor medium, an active electro-chromic medium, and a rear transparent conductor medium. The front and rear transparent conductor mediums are directly connected to each other by a conductive section located within the imaging path. Other embodiments are also described and claimed.