Adaptive Current Control for Image Sensor Noise Reduction
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Solution Overview
Problem
Conventional image capturing devices face challenges in achieving low electrical power consumption at high illuminance and low noise at low illuminance due to the sensitivity of noise levels to current consumption in analog circuits, which increases power usage and costs.
Innovation Solution
An image capturing apparatus with a photoelectric conversion element, a conversion unit, and a control unit that adjusts current flow to the analog circuit based on the output signal from the conversion unit, allowing adaptive control of current consumption to optimize power usage and noise levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If current consumed at an analog circuit is increased to reduce thermal noise, then noise level is reduced, but electrical power consumption increases
Solution Approach 1:
The patent implements dynamic current control in the analog circuit by using a control unit that adjusts the current consumed at the analog circuit in a variable manner on the basis of an AD converted output signal. This allows the system to adaptively change noise level according to actual imaging conditions, reducing thermal noise when needed while minimizing electrical power consumption during normal operation.
2Object-affected harmful factors
If current consumed at an analog circuit is increased to reduce 1/f noise, then noise level is reduced, but electrical power consumption increases
Solution Approach 1:
The control unit dynamically adjusts the current consumed at the analog circuit based on AD converted output signals, enabling the system to reduce 1/f noise adaptively only when necessary. This dynamic control mechanism ensures that increased current consumption for noise reduction is applied selectively rather than continuously, thereby reducing overall electrical power consumption.
3Object-affected harmful factors
If current consumed at an analog circuit is increased to reduce quantization noise, then noise level is reduced, but electrical power consumption increases
Solution Approach 1:
The system uses a control unit that adaptively changes the current consumed at the analog circuit in a variable manner based on AD converted output signals. This allows quantization noise to be reduced only when the imaging conditions require it, rather than maintaining high current consumption continuously, thereby achieving noise reduction while minimizing electrical 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
This approach enables low electrical power consumption at high illuminance and reduced noise at low illuminance by dynamically adjusting current consumption, thereby improving image quality and reducing power costs.
Implementation Method 1
Each image sensor includes a pixel in which a photodiode (PD) configured to perform photoelectric conversion
Data Source
AI summary
The present technology relates to an image capturing apparatus and an electronic device that are capable of reducing noise.A photoelectric conversion element, a conversion unit configured to convert a signal from the photoelectric conversion element into a digital signal, and a control unit configured to control current flowing to an analog circuit on the basis of an output signal from the conversion unit are provided. The conversion unit converts the signal from the photoelectric conversion element into a digital signal by using a slope signal having a level that monotonically decreases as time elapses. The control unit performs control to increase or reduce current flowing to the analog circuit in a case where the output signal has a large level. The present technology is applicable to, for example, an image capturing apparatus.