Combination Lens for Ambient Light and Proximity Sensing
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Solution Overview
Problem
Ambient light sensors and proximity sensors using optical components face limitations due to small photosensitive areas and inefficiencies in light detection, particularly in multi-functional sensing applications where both ambient and proximity detection are required.
Innovation Solution
An optical system with a combination optical element that separates light detection areas on a photodetector, using a PS portion to focus reflected light for proximity detection and an ALS portion to diffuse ambient light, allowing for efficient simultaneous detection and processing of both types of light signals on a shared IC chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single photodetector is used for both ambient light sensing and proximity sensing, then device complexity is reduced, but measurement precision deteriorates due to light signal interference
Solution Approach 1:
The photodetector is divided into two distinct photosensitive regions: a first photosensitive region for ambient light sensing and a second photosensitive region for proximity sensing. This segmentation allows each region to independently detect its respective light signal without interference from the other type of light, thereby maintaining measurement precision while using a single integrated sensor structure.
Solution Approach 2:
Different regions of the photodetector are assigned different functional properties: the first photosensitive region is optimized for detecting ambient light signals while the second photosensitive region is optimized for detecting reflected light signals from proximity objects. This local differentiation of functional quality enables precise detection of both light types simultaneously without cross-interference.
2Measurement precision
If the photosensitive area is increased to improve detection accuracy, then measurement precision improves, but device area increases
Solution Approach 1:
The single photodetector performs multiple functions by detecting both ambient light and proximity light signals simultaneously through its two photosensitive regions. This multi-functionality allows the sensor to achieve comprehensive detection capabilities without requiring separate sensors, thereby maintaining compact device area while improving overall detection accuracy through the combined functionality of both regions.
3Measurement precision
If separate sensors are used for ambient light sensing and proximity sensing, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent combines the ambient light sensing function and proximity sensing function into a single photodetector device with two specialized photosensitive regions. This merging approach integrates multiple sensing functions into one component, reducing device complexity by eliminating the need for separate sensors while maintaining measurement precision through the specialized design of each photosensitive region.
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
Enhances the sensitivity and accuracy of both ambient light and proximity sensing by optimizing light distribution across the photodetector, enabling effective multi-functional sensing without compromising battery life or increasing complexity.
Implementation Method 1
a PS portion to focus reflected light for proximity detection
Implementation Method 2
an ALS portion to diffuse ambient light
Implementation Method 3
receiving light that reflects off an object-to-be-detected at the photodetector
Data Source
AI summary
A sensor, optical system, and combination lens for use with an optical sensor are disclosed. An illustrative optical system is described to include a photodetector having a proximity sensor area and an ambient light sensor area that is physically separated from the proximity sensor area as well as a combination lens that includes a proximity sensor focusing portion and an ambient light sensor focusing portion that each separately direct incident light for the proximity sensor area and the ambient light sensor area, respectively.