Light Source Driving Device Nonlinear Dimming Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source control systems face challenges in approximating control values along a nonlinear dimming curve, such as a log curve, which requires a large number of stored control values, leading to increased costs due to the need for expensive storage units.
Innovation Solution
A light source driving device that uses a fade control table with three or more combinations of light control steps and duties, allowing for nonlinear dimming curve control through linear interpolation, reducing the need for extensive storage capacity by storing only key points on the dimming curve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large number of control values are stored in a storage unit to sufficiently approximate the control value to the nonlinear curve, then the approximation precision is improved, but the storage capacity and cost increase
Solution Approach 1:
The patent divides the fade control process into multiple light control steps (first light control step, second light control step, etc.). Instead of storing all intermediate control values, the system only stores control values at these segmented key points. The control values between key points are calculated through linear interpolation, thus segmenting the storage requirement into minimal essential points while maintaining curve approximation precision.
Solution Approach 2:
The patent pre-stores only the essential control values corresponding to key light control steps in the fade control table before operation. These preliminary stored values serve as anchor points that enable reconstruction of the entire nonlinear dimming curve through interpolation, avoiding the need to pre-store all possible intermediate values.
2Device complexity
If linear approximation is used to obtain control voltage for desired optical level, then the calculation simplicity is improved, but the dimming curve linearity deteriorates
Solution Approach 1:
The patent changes the parameter representation by storing control values (duties) corresponding to specific light control steps in a fade control table. Instead of using continuous linear approximation, the system uses discrete stored values at key points and performs linear interpolation between them. This parameter transformation allows the system to maintain simple calculation procedures while achieving nonlinear dimming curve characteristics through the selective storage and interpolation of control values.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A light source driving device 20 according to an embodiment includes a storage unit 202 that stores therein three or more combinations of a level indicating brightness of light emitted from a light source 301, and a control value used when light with brightness corresponding to the level is emitted from the light source 301, the control value having a nonlinear relation with the level; and a control unit 203 that controls the light source 301 so that the brightness of the light emitted from the light source 301 is gradually changed to brightness corresponding to a level indicated by a light control instruction signal to be supplied, by using two or more combinations among the combinations stored in the storage unit 202.