ToF Camera Proximity Detection Mode
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Solution Overview
Problem
Existing proximity sensors in mobile devices require additional space and power, making it challenging to incorporate them alongside other sensors in devices with limited space and power resources.
Innovation Solution
A Time of Flight (ToF) camera system that can operate in both a high-power depth imaging mode and a low-power proximity mode by adjusting the charge accumulation timing in the imaging sensor using a demodulation signal and applying column delays to determine object proximity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated proximity sensor is incorporated into the mobile device, then proximity detection capability is improved, but device space is reduced
Solution Approach 1:
The ToF camera system is configured to perform multiple functions: full depth imaging mode for comprehensive scene mapping and proximity detection mode for simple distance measurement. By making the ToF camera multi-functional, the patent eliminates the need for a separate dedicated proximity sensor, thereby saving device space while maintaining proximity detection capability
Solution Approach 2:
The patent combines the proximity detection function with the existing ToF camera system by introducing a delay block that applies column delays to the demodulation signal. This merging of functions allows the ToF camera to serve both depth imaging and proximity detection purposes, reducing the total number of sensors required in the device
2Reliability
If a dedicated proximity sensor is incorporated into the mobile device, then proximity detection capability is improved, but power consumption increases
Solution Approach 1:
The ToF camera system is configured to perform multiple functions: full depth imaging mode for comprehensive scene mapping and proximity detection mode for simple distance measurement. By making the ToF camera multi-functional, the patent eliminates the need for a separate dedicated proximity sensor, thereby saving device space while maintaining proximity detection capability
Solution Approach 2:
The patent combines the proximity detection function with the existing ToF camera system by introducing a delay block that applies column delays to the demodulation signal. This merging of functions allows the ToF camera to serve both depth imaging and proximity detection purposes, reducing the total number of sensors required in the device
3Measurement precision
If full ToF depth imaging mode is used, then depth mapping quality is improved, but power consumption increases
Solution Approach 1:
The system dynamically switches between two operational modes: full depth imaging mode for high-quality depth mapping and proximity detection mode for low-power operation. The image acquisition system can adaptively select the appropriate mode based on the current application requirements, optimizing the balance between measurement precision and power consumption
Solution Approach 2:
The patent changes the operational parameters of the ToF camera by applying column delays to the demodulation signal in proximity detection mode. This parameter change enables the system to operate in a simplified mode that consumes less power while still providing accurate proximity information, trading off some depth mapping quality for reduced power consumption
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 a single ToF camera system to perform both high-quality depth imaging and low-power proximity detection, reducing the need for multiple sensors and conserving device space and power.
Implementation Method 1
an imaging sensor comprising a plurality of pixels configured to accumulate charge based on incident light that comprises laser light reflected by the object
Implementation Method 2
a delay block arranged to apply a column delay to the demodulation signal used by pixel columns of the imaging sensor, such that the timing of application of the demodulation signal to at least some of the plurality of pixel columns of the imaging sensor is different
Data Source
AI summary
Systems and methods for a Time of Flight (ToF) camera system configured to be operable in a proximity mode. In the proximity mode, the proximity of an object may be estimated by relatively delaying or offsetting the charge accumulation timing of multiple different columns of pixels of the ToF imaging sensor. The relative charge accumulated in those pixel columns is dependent on the proximity of the object and the relative time delays in charge accumulation of each column. Therefore, by reading out the charge accumulated in multiple different pixel columns and knowing the relative accumulation delay of those pixel columns, the proximity of an object may be determined. This enables the operation of the ToF camera system to be switched between relatively high power, full ToF depth imaging, and relatively low power proximity mode of operation, thereby rendering a single system as being capable of performing two different functions.