CMOS Rolling Shutter Camera Light Filling Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CMOS video cameras using rolling shutter exposure require inefficient and constant light filling, reducing light-filling efficiency and shortening the working life of light-filling lamps, as they are always on rather than only being active when needed.
Innovation Solution
A method and system for a CMOS video camera that determines a strobe period based on frame interval and exposure time, using a light-filling lamp with a predetermined duty cycle greater than 0 and less than 1, optimizing light filling by only illuminating when necessary, and calculating the strobe period through greatest common divisors and factor selection to improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a normally on light-filling lamp is used to fill light for the CMOS video camera, then the light filling is continuous and stable, but the light-filling efficiency is low and the working life of the light-filling lamp is shortened
Solution Approach 1:
The patent applies periodic action by controlling the light-filling lamp to operate in periodic pulses rather than continuously. The control module activates the lamp during specific exposure periods and deactivates it during other periods, creating a pulsed illumination pattern that matches the rolling shutter exposure cycles. This periodic operation maintains necessary illumination stability while significantly reducing overall lamp usage time, thereby extending working life and improving light-filling efficiency.
Solution Approach 2:
The patent implements dynamics by making the light-filling lamp's operation state changeable between on and off based on real-time exposure requirements. The control module dynamically adjusts the lamp's operation status according to the rolling shutter exposure timing, transitioning from a static always-on state to a dynamic state-responsive operation. This dynamic control ensures illumination is provided only when needed during pixel exposure, optimizing both efficiency and lamp longevity.
2Illumination intensity
If a normally on light-filling lamp is used to fill light for the CMOS video camera, then the illumination is always available, but the light-filling efficiency is reduced
Solution Approach 1:
The patent applies periodic action by controlling the light-filling lamp to operate in periodic pulses rather than continuously. The control module activates the lamp during specific exposure periods and deactivates it during other periods, creating a pulsed illumination pattern that matches the rolling shutter exposure cycles. This periodic operation maintains necessary illumination stability while significantly reducing overall lamp usage time, thereby extending working life and improving light-filling efficiency.
Solution Approach 2:
The patent applies partial action by providing illumination only during the specific partial time periods when pixel exposure occurs, rather than during the entire operational cycle. The control module activates the lamp only for the duration needed to illuminate the scene during rolling shutter exposure, and keeps it off during periods when illumination is not required. This partial illumination approach maintains sufficient lighting availability during critical exposure moments while dramatically improving overall light-filling efficiency by eliminating wasted illumination during non-exposure periods.
3Illumination intensity
If the light-filling lamp is always on, then sufficient illumination is provided at all times, but power consumption increases and lamp life decreases
Solution Approach 1:
The patent applies periodic action by controlling the light-filling lamp to operate in periodic pulses rather than continuously. The control module activates the lamp during specific exposure periods and deactivates it during other periods, creating a pulsed illumination pattern that matches the rolling shutter exposure cycles. This periodic operation maintains necessary illumination stability while significantly reducing overall lamp usage time, thereby extending working life and improving light-filling efficiency.
Solution Approach 2:
The patent applies partial action by providing illumination only during the specific partial time periods when pixel exposure occurs, rather than during the entire operational cycle. The control module activates the lamp only for the duration needed to illuminate the scene during rolling shutter exposure, and keeps it off during periods when illumination is not required. This partial illumination approach maintains sufficient lighting availability during critical exposure moments while dramatically improving overall light-filling efficiency by eliminating wasted illumination during non-exposure periods.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present disclosure provides a Complementary Metal Oxide Semiconductor (CMOS) video camera and method for filling light, the CMOS video camera using an exposure way of rolling shutter. The method includes: acquiring a frame interval and an exposure time of each line of pixels; determining a strobe period according to the acquired frame interval and exposure time of each line of pixels; and filling light for each frame of an image by using a light-filling lamp according to the determined strobe period and a predetermined duty cycle, wherein the predetermined duty cycle is larger than 0 and lower than 1. According to the present disclosure, the light-filling efficiency is improved, and the working life of the light-filling lamp is prolonged.