Imaging Device Selective Pixel Readout for Power Reduction
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Solution Overview
Problem
Conventional imaging devices face increased power consumption and noise levels due to the need to read out both image data for display and phase difference detection simultaneously, leading to reduced battery life and image quality in mobile devices.
Innovation Solution
An imaging device with a pixel group having unit pixels receiving light through different pupil areas, equipped with color filters and a microlens, reads out focus detection signals and only the signal corresponding to detected subject color information, optimizing data readout to reduce power consumption and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If both image data for display and image data for phase difference detection are read out simultaneously, then focus detection accuracy is improved, but power consumption increases and noise level increases
Solution Approach 1:
The patent extracts only the necessary pixel signals for phase difference detection based on the detected subject color. Instead of reading out all pixel data, the system selectively reads out signals only from pixels corresponding to the detected subject color (e.g., red pixels for red subjects, green pixels for green subjects), thereby reducing power consumption while maintaining focus detection accuracy.
Solution Approach 2:
The patent changes the readout parameters dynamically based on subject color detection. The system adjusts which pixel signals are read out (red, green, or blue pixels) according to the detected subject color, optimizing the balance between focus detection accuracy and power consumption by adapting to different shooting scenarios.
2Measurement precision
If both image data for display and image data for phase difference detection are read out simultaneously, then focus detection accuracy is improved, but noise level increases
Solution Approach 1:
The patent extracts only the necessary pixel signals for phase difference detection based on the detected subject color. By reading out signals only from pixels corresponding to the detected subject color rather than all pixels, the system reduces the total data processing load and minimizes noise while maintaining focus detection accuracy.
3Speed
If readout period is shortened to accommodate both image data types, then real-time display performance is improved, but operation time of image sensor increases leading to higher power consumption
Solution Approach 1:
The patent extracts and reads out only the necessary pixel signals for phase difference detection based on subject color, reducing the total readout time required. This allows the system to maintain fast readout speeds for real-time display while reducing the image sensor's operation time and power consumption by eliminating redundant readouts.
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 allows for efficient power management and improved image quality by selectively reading out signals, maintaining autofocus performance while minimizing power usage and noise, thus extending battery life and ensuring clear live-view displays.
Implementation Method 1
a microlens provided in correspondence with the color filter
Implementation Method 2
unit pixels including a plurality of pixels receiving light fluxes
Data Source
AI summary
An imaging device, comprising: a pixel group in which unit pixels including a plurality of pixels receiving light fluxes having passed through different pupil areas of a photographing lens are provided in a form of a matrix; a plurality of types of color filters with different spectral transmittances provided in correspondence with the unit pixels; a microlens provided in correspondence with the color filter; a color information detection circuit which detects subject color information; and a pixel signal readout circuit which reads out a focus detection signal from the pixel group and reads out only a signal of the unit pixel in correspondence with a color filter associated with subject color information detected by the color information detection circuit.