Proximity Sensor Boost Emitter for Dark-Condition Accuracy
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Solution Overview
Problem
Proximity sensors based on infrared light detection face challenges in accurately determining object proximity due to environmental conditions such as varying ambient light, which can lead to incorrect readings and reduced photodiode responsivity, especially in dark conditions.
Innovation Solution
Incorporating a boost emitter within the proximity sensor's housing to directly illuminate the photodiode, maintaining its charge carriers and responsivity under dark conditions by priming it with infrared light before sensing, thereby preventing direct illumination interference and maintaining linear responsivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the photodiode is used for proximity sensing in dark conditions, then power consumption is reduced, but the photodiode responsivity deteriorates and detection accuracy decreases
Solution Approach 1:
The boost emitter performs preliminary illumination of the photodiode before the actual sensing operation in dark conditions. This preliminary action maintains the photodiode's charge carrier population and responsivity, ensuring accurate detection when the sensor is activated without requiring continuous illumination that would increase power consumption.
Solution Approach 2:
The boost emitter acts as an intermediary component that provides auxiliary infrared illumination to the photodiode. This intermediary light source compensates for the lack of ambient light in dark conditions, enabling the photodiode to maintain its sensing capability without requiring higher operating power.
2Illumination intensity
If the first light emitter illuminates the display, then the display brightness is improved, but the proximity detection accuracy deteriorates due to direct illumination of the photodiode
Solution Approach 1:
The housing structure segments the optical paths by implementing separate illumination zones. The first light emitter's illumination is confined to the display area through strategic positioning and housing geometry, while the photodiode is positioned in a region shielded from this direct illumination, thus preventing false proximity signals while maintaining display brightness.
Solution Approach 2:
Different regions of the device are assigned different optical properties. The display region receives direct illumination from the first light emitter for brightness, while the photodiode region is designed with shielding characteristics to reject this illumination, allowing each component to operate in its optimal optical environment.
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
This approach enhances the accuracy of proximity detection under changing light conditions, reducing errors and power consumption while minimizing visual artifacts on displays.
Implementation Method 1
The first light emitter is configured to emit light for a first time period
Implementation Method 2
a light detector (e.g., a photodiode or phototransistor)
Implementation Method 3
a second light emitter (e.g., an infrared light emitter)
Implementation Method 4
The light detector is configured to detect light during a second time period while the second light emitter is emitting light
Data Source
AI summary
Devices, methods, and systems for detecting proximity. A first light emitter emits light for a first time period while a light detector is not sensing. A second light emitter emits light for a second time period while the light detector is sensing. In some implementations, the first light emitter directly illuminates the light detector during the first time period, whereas the second light emitter is obstructed from directly illuminating the light detector during the second time period. In some implementations, the first light emitter is obstructed from illuminating a display during the first time period, and the second light emitter is obstructed from directly illuminating the light detector during the second time period. In some implementations, the first light emitter emits the light during the first time period such that the light detector maintains a linear responsivity during the second time period.