BJT Pixel Pre-Flash Time Adaptation for Image Sensors
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Solution Overview
Problem
Conventional image sensor devices with BJT pixels require a fixed and long pre-flash time to ensure operation on various surfaces, leading to high power consumption.
Innovation Solution
Adaptive adjustment of pre-flash time based on surface quality signals and shutter turn-on time for BJT pixels in an image sensor apparatus, minimizing the turn-on time of the light emitting circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed and long pre-flash time is configured for BJT pixels, then the image sensor device can operate on various working surfaces to generate good tracking results, but the total turn-on time period of the light emitting unit increases and power consumption becomes higher
Solution Approach 1:
The patent implements dynamic adjustment of pre-flash time based on detected surface characteristics. The system transitions from a fixed pre-flash time configuration to a variable one that adapts to different working surfaces. The processor determines optimal pre-flash time values based on surface reflectivity and texture characteristics, allowing the light emitting unit to use shorter pre-flash times for favorable surfaces while maintaining sufficient pre-flash duration for challenging surfaces, thereby reducing overall power consumption while preserving tracking performance.
Solution Approach 2:
The patent changes the pre-flash time parameter dynamically based on surface quality assessment. The system measures surface characteristics (such as reflectivity and texture) and adjusts the pre-flash time parameter accordingly. This parameter adaptation allows the system to use minimal pre-flash time when surface conditions permit, reducing the total turn-on time and power consumption, while ensuring adequate pre-flash duration when surface conditions require it for reliable tracking.
2Stability of the object's composition
If a fixed and enough long pre-flash time is configured, then stable beta condition can be achieved for BJT pixels on various surfaces, but the total turn-on time period of the light emitting unit is dominated by this fixed time
Solution Approach 1:
The system dynamically adjusts pre-flash time based on real-time surface characterization. Instead of using a fixed pre-flash time that guarantees stable beta condition for all surfaces, the processor evaluates surface properties and determines the minimum pre-flash time required to achieve stable beta condition for each specific surface. This dynamic approach reduces total turn-on time when stable beta condition can be achieved with shorter pre-flash durations.
Solution Approach 2:
The patent applies partial action by using only the necessary amount of pre-flash time required to achieve stable beta condition for each surface, rather than applying excessive fixed pre-flash time to all surfaces. The system determines the sufficient pre-flash duration based on surface characteristics, avoiding unnecessary extended pre-flash periods that would increase total turn-on time without providing additional benefit for favorable surfaces.
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 reduces power consumption and extends battery life while maintaining tracking performance by dynamically adjusting the pre-flash time according to the surface quality and shutter turn-on time.
Implementation Method 1
a bipolar-junction-transistor (BJT) pixel which is configured to sense a first image
Data Source
AI summary
A method applied to a BJT pixel of an image sensor apparatus includes: obtaining at least one of a surface quality signal of a first image sensed by the BJT pixel and a shutter turn-on time corresponding to the first image; and adaptively adjusting a pre-flash time of the BJT pixel for sensing of a second image according to the at least one of the surface quality signal of the first image and the shutter turn-on time corresponding to the first image; wherein the second image follows the first image.