Coherent Light Source Dimming via DAC Gain and Data Division
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing laser-based projection systems, such as HUDs, face challenges in controlling laser intensity without affecting color combinations and require wide dynamic range dimming to adapt to varying ambient illuminations, which current methods like variable optical attenuators are unable to effectively address due to limited gray scale resolution and increased system cost.
Innovation Solution
A method utilizing independently controlled dimming components, including laser pixel width, Data Reference DAC gain, and data value division, to achieve a wide dimming ratio without increasing system cost or size, by reducing laser power consumption and maintaining color balance through correction factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If variable optical attenuators are used to control laser intensity, then the laser intensity can be reduced, but the system cost increases and the gray scale resolution remains limited
Solution Approach 1:
The patent replaces the mechanical variable optical attenuator system with an electronic control system that manipulates laser data current through DAC gain adjustment and data value division. This substitution eliminates the need for complex optical attenuation hardware while achieving the same intensity control function through electronic means, thereby reducing system cost and complexity.
Solution Approach 2:
The patent changes the control parameter from optical attenuation to electrical current control by adjusting the Data Reference DAC gain and dividing data values. This parameter transformation allows intensity control to be achieved through electronic gain adjustment rather than mechanical optical attenuation, resolving the contradiction between intensity control capability and system complexity.
2Illumination intensity
If variable optical attenuators are used to control laser intensity, then the laser intensity can be reduced, but the gray scale resolution is limited to 8 or 10 bits
Solution Approach 1:
The patent segments the intensity control function into two independent parts: DAC gain adjustment for coarse control and data value division for fine control. This segmentation allows the system to achieve high effective resolution by combining the precision of gain adjustment with the granularity of data division, exceeding the limitations of traditional 8 or 10-bit gray scale systems.
Solution Approach 2:
The patent adds a new dimension to intensity control by introducing data value division as a separate control mechanism alongside DAC gain adjustment. This dimensional expansion transforms the control space from a single 8 or 10-bit parameter to a two-dimensional control space, enabling resolution beyond traditional gray scale limitations.
3Illumination intensity
If the intensity of color components is changed to control laser intensity, then the brightness can be adjusted, but the color combination is affected
Solution Approach 1:
The patent introduces data value division as an intermediary mechanism that controls overall intensity independently of color component ratios. By using division as a mediator applied uniformly across all color channels, the system can adjust brightness without disrupting the color balance, unlike direct intensity modification of individual color components.
Solution Approach 2:
The patent makes the data value division mechanism universal across all color channels, applying the same division factor to red, green, and blue components simultaneously. This universal application ensures that intensity adjustment maintains color proportions while the DAC gain adjustment provides channel-specific control, together achieving brightness control without color distortion.
Data Source
AI summary
A system and method for providing a dimming factor of N using a laser display device having plural colored laser diodes each generating a colored laser beam according to control parameters. At least one of the control parameters of at least one of the laser diodes is varied, at least one of the control parameters being operative to reduce intensity of at least one of the colored laser beams. Varying may comprise providing a dimming factor of m<N using first laser diode data current control apparatus able to provide m<N dimming levels and a dimming factor of at least N/m<N, using at least a second laser diode data current control apparatus able to provide a dimming factor of at least N/m, but less than N.