VLC Light Dimming Method for Inter-Frame Flicker Alleviation
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Solution Overview
Problem
Existing Visible Light Communication (VLC) technologies face challenges in minimizing inter-frame flicker during data transmission, which affects the normal use of illumination equipment and requires accurate calculation of the duty cycle for the light source to match the line coding scheme.
Innovation Solution
A light dimming method and device that calculates the average luminance values of data and illumination states, determining if inter-frame flicker occurs and inserting a dimming frame with a calculated duty cycle range to compensate for luminance differences, ensuring the duty cycle of the dimming frame is within a specific range to avoid perceivable luminance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a sender in an idle/receiving state adopts an idle pattern with a frame used for regulating luminance, then inter-frame flicker can be alleviated, but the requirement for accurate calculation of duty cycle increases system complexity
Solution Approach 1:
The patent changes the parameter approach from requiring exact duty cycle matching to allowing a range of acceptable duty cycles. By defining a duty cycle range [A-K, A+K] instead of requiring precise equality, the system maintains flicker alleviation effectiveness while reducing calculation and implementation complexity.
Solution Approach 2:
The patent introduces dynamic adjustment capability by allowing the dimming frame duty cycle to vary within a calculated range rather than being fixed. This dynamic approach enables the system to adapt to different line coding schemes and transmission conditions while maintaining simplicity through the standardized range calculation method.
2Illumination intensity
If the duty cycle of the dimming frame is required to be exactly equal to the line coding scheme's duty cycle, then average luminance values match, but the luminance range for dimming is limited
Solution Approach 1:
The patent transforms the duty cycle parameter from a precise matching requirement to a range-based parameter. By defining the dimming frame duty cycle range as [A-K, A+K] where A is the line coding duty cycle and K is a constant, the system extends the usable luminance range while maintaining adequate flicker compensation.
Solution Approach 2:
The patent applies partial action by not requiring complete precision in duty cycle matching. Instead of demanding exact equality between dimming frame and data frame duty cycles, the system accepts a controlled deviation within the K tolerance, which is sufficient to prevent perceptible flicker while enabling broader luminance adjustment range.
3Reliability
If accurate calculation of duty cycle is required to match line coding scheme, then data transmission and illumination can coexist, but the system operation becomes more complex
Solution Approach 1:
The patent simplifies system operation by changing from precise parameter calculation to range-based parameter setting. The dimming frame duty cycle is set within [A-K, A+K] range using a standardized calculation method, which ensures reliable coexistence of data transmission and illumination while being easier to implement and maintain.
Data Source
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AI summary
Provided are a light dimming method for alleviating inter-frame flicker and dimming device, which relate to a Visible Light Communication (VLC) technology. The light dimming method includes that: an average luminance value Avgdata when a sender sends physical frames is calculated; whether inter-frame flicker is generated when the sender sends data or not is judged according to a ratio of Avgdata to an average luminance value Avglight in an illumination state; and if the inter-frame flicker is generated when the sender sends the data, the sender inserts a dimming frame in an idle pattern, wherein the dimming frame is used for compensating for a luminance difference between Avgdata and Avglight. In addition, a light dimming device for alleviating inter-frame flicker is also provided. A value of a duty cycle of the physical frame sent to regulate the luminance of the light source in the idle pattern of the sender is within a certain range, and is not required to be accurately equal to a duty cycle of a line coding method adopted for a physical layer.