Flash Control Circuit Timing Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mobile terminal flash systems face issues with uneven brightness and prolonged flash duration, leading to unclear photos and user discomfort, as they lack a mechanical shutter and have difficulty in accurately controlling the flash-on time.
Innovation Solution
A control method and apparatus that determine the turn-on time of the flash based on output time and exposure time information, using a logic gate circuit to generate a pulse signal for the flash, ensuring it is only active during the necessary time periods, thereby shortening the flash-on time and improving user experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the flash brightness setting is increased to improve photo clarity, then the captured photo becomes clearer, but the flash irritates the eyes of the subject
Solution Approach 1:
The patent implements dynamic control of the flash by precisely timing its activation to coincide exactly with the image sensor's exposure window. The flash controller adjusts the flash duration and timing based on exposure parameters, ensuring the flash operates only during the brief moment when the sensor is capturing light, thereby maintaining necessary brightness while minimizing eye irritation from prolonged exposure.
Solution Approach 2:
The system changes the temporal parameters of flash operation by controlling the flash duration to match the exposure time window. Instead of using a fixed or prolonged flash duration, the controller dynamically adjusts the flash activation time and duration based on the exposure time information from the image sensor, optimizing both photo quality and subject comfort.
2Reliability
If the flash duration is prolonged to ensure light capture without a mechanical shutter, then the camera chip can capture the flash light, but the flash duration is excessively long causing user discomfort
Solution Approach 1:
The system employs feedback from the image sensor's exposure time information to control the flash duration. The flash controller receives timing information from the sensor about when exposure begins and ends, and uses this feedback to precisely control the flash activation window, ensuring the flash operates only during the exact period when the sensor is capturing light, thus achieving reliable light capture with minimal duration.
Solution Approach 2:
The flash system transitions from static or prolonged flash duration to dynamic timing control. The controller continuously monitors exposure time information and adjusts the flash activation timing accordingly, making the flash duration adaptive to the specific exposure requirements rather than using a fixed extended duration.
3Device complexity
If the flash is controlled without precise timing information, then the control system is simpler, but the flash-on time cannot be accurately controlled leading to uneven brightness
Solution Approach 1:
The patent merges the flash control function with the image sensor's existing timing information system. By utilizing the exposure time information already generated by the sensor for its normal operation, the flash controller can achieve precise timing synchronization without requiring separate complex timing generation circuits, thus maintaining relatively simple system architecture while achieving accurate flash timing.
Data Source
AI summary
Embodiments of the present disclosure provides a method, including: obtaining an output time of an image being taken by an image capturing apparatus; obtaining an exposure time of the image being taken by an image capturing apparatus; and based on the output time and the exposure time, controlling a turn-on time of a flash corresponding to the image being taken by the image capturing apparatus.