Imaging Reader Illumination Rate Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging readers experience annoying illumination pulses due to synchronized frame and illumination rates, leading to flashing light perception, especially at low frame rates or with newer megapixel sensor arrays, which is undesirable.
Innovation Solution
Decoupling the illumination and frame rates by energizing the illuminating light source during both exposure and non-exposure periods to produce a consistently high illumination rate, independent of the frame rate, ensuring illumination pulses are perceived as continuous by the human eye.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the illumination rate is synchronized to the frame rate, then power consumption is reduced and heat buildup is minimized, but annoying illumination pulses are produced at low frame rates
Solution Approach 1:
The illumination function is segmented into two independent control systems: one synchronized with the frame rate for power efficiency, and another running at a fixed high rate to eliminate visible flicker. This allows the illumination to be divided into functional segments that address different requirements simultaneously.
Solution Approach 2:
The illumination rate is made dynamic and adaptable rather than strictly synchronized. The system can operate at different illumination rates independent of frame rate changes, allowing it to maintain high illumination rates even when frame rates drop, thereby eliminating annoying pulses while preserving power efficiency at higher frame rates.
2Measurement precision
If the frame rate is reduced for longer exposure time or slower video modes, then image quality is improved, but the synchronized illumination rate produces visible flashing
Solution Approach 1:
The illumination control is segmented into frame-synchronized illumination for power efficiency and a separate high-rate illumination component that operates independently to eliminate visible flicker during low frame rate operations.
Solution Approach 2:
The illumination action is made continuous at a high rate independent of frame rate variations. By maintaining a constant high illumination rate separate from the frame rate, the system ensures continuous useful illumination without the interruptions that cause visible flashing during low frame rate operation.
3Loss of energy
If the illumination rate is automatically reduced with frame rate reduction, then power consumption is minimized, but the human eye perceives annoying pulses
Solution Approach 1:
The illumination system is segmented into two independent rate controls: a frame-rate-synchronized component for power management and a fixed high-rate component for user comfort. This allows selective operation where the high-rate component runs continuously or near-continuously to prevent visible flicker while the synchronized component handles power-efficient baseline illumination.
Solution Approach 2:
The illumination rate parameter is decoupled from the frame rate parameter. Instead of automatically reducing illumination rate with frame rate, the system maintains the illumination rate at a fixed high value independent of frame rate changes, changing the operational parameter relationship to prioritize user comfort while managing power consumption through alternative means.
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 prevents reduction in illumination rate with frame rate reductions, eliminating annoying flashing and maintaining a high, continuous illumination perception regardless of sensor array settings.
Implementation Method 1
an imaging lens assembly for capturing return light scattered and/or reflected from the target being imaged along an imaging axis through the window, and for projecting the return light onto the sensor array to initiate capture of an image of the target during an exposure time period
Implementation Method 2
an illuminating light assembly is provided for illuminating the target with illumination light from an illuminating light source, e.g., one or more light emitting diodes (LEDs) and illuminating lenses, through the window for reflection and scattering from the target
Data Source
AI summary
An imaging module for electro-optically imaging a target, includes an energizable illuminating light source for illuminating the target with illumination light for return from the target, an energizable solid-state imager for capturing return light from the target, and a controller for energizing the imager during an exposure time period to capture the return light at a frame rate, for deenergizing the imager during a non-exposed time period, and for energizing the illuminating light source not only during the exposure time period, but also during the non-exposed time period, to produce a plurality of illumination light pulses at an illumination rate that enables the human eye to perceive the illumination light pulses as substantially continuous. The illumination rate of one or more of the illumination light pulses produced during the non-exposed time period is substantially independent and decoupled from the frame rate.