Laser Beam Intensity Stabilization in Head-Up Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser scanning image display systems face issues with reduced image quality due to stray light generated when a characteristics detecting laser beam is scattered on a gobo, leading to fluctuations in temperature affecting the output of laser light sources and resulting in unstable operations.
Innovation Solution
An image rendering apparatus with a light source unit, detecting unit, optical scanner, and adjusting unit that emits a characteristics detecting laser beam in a position and pattern corresponding to the rendered content, allowing for real-time adjustment of the laser beam output based on detected intensity, eliminating the need for a gobo to shield the detecting beam and thus preventing stray light from reaching the rendered image area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a gobo is used to shield the characteristics detecting laser beam, then the laser beam output can be detected, but stray light is generated that reaches the rendered image area and reduces image quality
Solution Approach 1:
The patent separates the detection beam path from the rendering beam path by using different spatial dimensions. The characteristics detecting laser beam is directed to a specific detection area on the screen that is spatially separated from the rendered image display area. This dimensional separation allows the detecting beam to be measured without its scattered light interfering with the rendered images, resolving the contradiction between detection capability and image quality.
2Reliability
If the laser light source temperature fluctuates, then the output value of the laser beam changes, but this causes errors in detection and reduces measurement precision
Solution Approach 1:
The patent implements a feedback mechanism where the detected laser beam intensity is used to adjust the driving current of the laser light source. The system continuously monitors the actual amount of light output and compares it with the target value, then adjusts the driving current to compensate for temperature-induced fluctuations. This closed-loop feedback control maintains measurement precision and output stability despite temperature variations.
Solution Approach 2:
The system uses a portion of its own laser beam output to detect and correct its performance characteristics. The characteristics detecting laser beam is drawn from the same laser light source that generates the rendering beams, allowing the system to self-diagnose and self-correct output variations caused by temperature changes without requiring external calibration equipment.
3Measurement precision
If a gobo is used to shield the detecting beam, then detection can be performed, but the device complexity increases due to additional components
Solution Approach 1:
The patent extracts the detection function from the rendering optical path by separating the detecting beam generation and rendering beam generation. Instead of using a gobo to shield the beam within a single optical path, the system extracts a portion of the laser output specifically for detection purposes and directs it to a separate detection area on the screen. This eliminates the need for complex shielding structures like gobos while maintaining detection capability.
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 solution stabilizes the output of the laser light source, reduces errors caused by temperature fluctuations, and maintains image quality by projecting the characteristics detecting laser beam directly onto the screen without scattering, enhancing the rendering process and reducing manufacturing costs.
Implementation Method 1
a light source unit configured to emit a laser beam
Implementation Method 2
an amount of the laser beam is measured by a photodiode in order to obtain an actual amount of light
Data Source
AI summary
An image rendering apparatus includes a light source unit, a detecting unit, an optical scanner, a light source driving unit, and an adjusting unit. The light source driving unit is configured to control the light source unit in such a way that a rendered image is generated by the scan of the optical scanner inside a scan area scanned by the optical scanner and that a characteristic laser beam is emitted at a position and in a pattern corresponding to a rendered content of the rendered image. The rendered image includes an indicator related to a speed of a vehicle. The light source driving unit is configured to control the light source unit to emit the characteristics detecting laser beam in such a way that a scale for the indicator related to the speed of the vehicle is rendered.