Imaging System Selective A/D Power Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing number of pixels in image sensing apparatuses leads to higher power consumption and heat generation in A/D converting units, degrading image quality due to increased dark current and fixed pattern noise.
Innovation Solution
An imaging system that selectively supplies power to A/D converting units only when they receive signals from the pixel array, reducing power consumption and heat generation by switching off units not in use during the 1-line period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If all A/D converting units are driven simultaneously, then quick processing of image signals is achieved, but power consumption and heat generation increase
Solution Approach 1:
The patent implements periodic action by sequentially activating A/D converting units in batches corresponding to row selection periods. Instead of all units operating simultaneously, units are activated periodically based on which rows are being read out, thereby reducing overall power consumption while maintaining processing speed for active data.
Solution Approach 2:
The patent segments the A/D converting units into multiple groups corresponding to different rows in the pixel array. Each group is activated independently based on row selection, allowing only the necessary units to operate at any given time. This segmentation enables parallel processing of different data while reducing total power consumption.
2Speed
If all A/D converting units are driven simultaneously, then quick processing of image signals is achieved, but heat generation increases causing dark current and fixed pattern noise
Solution Approach 1:
By periodically activating only the A/D converting units corresponding to currently selected rows, the patent reduces continuous heat generation across all units. The periodic activation pattern ensures that temperature rise is limited to active units only, preventing the widespread thermal effects that would cause increased dark current and fixed pattern noise.
Solution Approach 2:
Segmenting the A/D converting units into row-based groups allows selective operation of only those units currently processing data. This segmentation prevents simultaneous operation of all units, thereby reducing overall heat generation and the associated thermal noise problems in the image sensing apparatus.
3Use of energy by moving object
If A/D converting units are not supplied with power, then power consumption is reduced, but signal processing capability is lost
Solution Approach 1:
The patent maintains signal processing capability by periodically supplying power to A/D converting units in sync with row selection. Units are powered on only when their corresponding rows are being read out, ensuring continuous processing capability for active data while minimizing power consumption during idle periods.
Solution Approach 2:
The patent employs preliminary action by pre-selecting which A/D converting units will be activated based on the row selection signal before actually powering them on. This allows the system to prepare the necessary processing capability in advance and activate only the required units, ensuring smooth signal processing without unnecessary 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 reduces power consumption, minimizes heat generation, and improves image quality by lowering dark current and fixed pattern noise, especially in high-speed continuous image acquisition scenarios.
Implementation Method 1
The A/D converting unit 4 A/D-converts the analog signal to generate a digital image signal
Implementation Method 2
The image sensing apparatus 700 photoelectrically converts an object image formed on its image sensing surface to generate an analog image signal
Data Source
AI summary
An imaging system comprises an image sensing apparatus including a pixel array, a row selection unit, and a readout unit; and a supply unit including a plurality of A/D converting units, and a transfer unit. The supply unit supplies a power supply voltage to an A/D converting unit which, of the plurality of A/D converting units, receives signals from the pixels in the pixel array by means of the transfer unit, and does not supply a power supply voltage to an A/D converting unit which, of the plurality of A/D converting units, receives no signals from the pixels in the pixel array by means of the transfer unit, in a 1-line period. The readout unit A/D-converts the signals from the pixels in the pixel array using the A/D converting unit supplied with the power supply voltage by the supply unit, and outputs a digital image signal.