Always-On Image Sensor Mode Switching for Mobile Power Saving
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Solution Overview
Problem
Image sensors in mobile devices do not operate in ultra-low power mode, leading to unnecessary battery consumption during low-power states.
Innovation Solution
Implementing an image sensor with an always-on (AON) mode that captures low-resolution images during low-power states and high-resolution images during normal-power states, utilizing a sensor hub to analyze sensor data for state changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image sensors operate continuously in normal-power state to capture high resolution image data, then image quality and functionality are maintained, but battery power is consumed unnecessarily during low-power states
Solution Approach 1:
The image sensor dynamically switches between two operational modes: a low-power mode during low-power states and a normal mode during active states. This dynamic adaptation allows the sensor to optimize power consumption based on device state while maintaining image quality when needed.
Solution Approach 2:
The patent changes operational parameters of the image sensor based on device power state. During low-power states, the sensor operates with reduced power consumption parameters; during active states, it transitions to full-performance parameters, thereby resolving the contradiction between power saving and image quality.
2Use of energy by moving object
If image sensors are powered down during low-power states to conserve battery, then power consumption is reduced, but the device cannot detect scene changes or perform face recognition
Solution Approach 1:
The patent segments the image sensor's functionality into two distinct modes: a low-power monitoring mode that maintains basic scene detection capability, and a full-performance mode for high-quality image capture. This segmentation allows the device to maintain reliability for wake-up detection while reducing power consumption.
Solution Approach 2:
During low-power states, the image sensor performs partial action by capturing images at reduced resolution or with reduced frequency, which is sufficient for scene change detection and face recognition but consumes less power than full-resolution capture.
3Use of energy by moving object
If image sensors capture low resolution image data in low-power mode, then battery power is conserved, but image quality is reduced
Solution Approach 1:
The patent applies partial action by capturing images at low resolution during low-power states. This partial action is sufficient for the intended purpose of scene detection and face recognition, while avoiding the excessive power consumption of full-resolution capture.
Solution Approach 2:
The image sensor applies local quality by focusing capture effort on key regions of interest (such as faces) at higher detail while using lower resolution for the overall scene, thereby maintaining detection accuracy while reducing overall power consumption.
Data Source
AI summary
A mobile device includes an application processor and an image sensor. The application processor includes an imaging subsystem configured to process high resolution image data through a first interface and a sensor hub configured to process sensor data through a second interface. The image sensor operates in one of first and second modes. The image sensor is configured to capture the high resolution image data in response to a request from the imaging subsystem and the imaging subsystem is configured to access the high resolution image data using the first interface for performing a first operation, during the first mode. The image sensor is configured to capture low resolution image data and the sensor hub is configured to access the low resolution image data using the second bus for performing a second operation, during the second mode.