Laser Scanning Display Device with Dither Noise Normalization
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Solution Overview
Problem
Existing laser scanning display devices face challenges in maintaining high resolution and luminance when dealing with high resonance frequencies and increased oscillation quantities of micro-mirrors, particularly due to fixed laser modulation frequencies that can lead to uneven pixel arrangements and missing pixels.
Innovation Solution
A scanning display device with a laser control unit that includes a dither noise generator and normalizing unit to adjust pixel addresses, ensuring accurate pixel placement and distribution, even with fluctuating resonance frequencies, by normalizing scanning positions and using a pixel address table to read image data from an image memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the laser modulation frequency is fixed, then the device complexity is reduced, but the manufacturing precision deteriorates due to insufficient resolving property causing uneven pixel arrangement
Solution Approach 1:
The patent applies dynamics by making the pixel address determination adaptive rather than fixed. The system dynamically adjusts pixel addressing based on actual mirror scanning positions, allowing the pixel mapping to flex and adapt to resonance frequency variations while keeping the laser modulation frequency fixed. This resolves the contradiction by introducing dynamic adaptation at the software/addressing level.
Solution Approach 2:
The patent changes the parameter of pixel address assignment based on scanning position feedback. By monitoring actual mirror positions and adjusting pixel address mapping accordingly, the system compensates for frequency drift and maintains uniform pixel arrangement without changing the laser modulation frequency. This parameter adaptation resolves the precision issue while maintaining fixed frequency operation.
2Manufacturing precision
If the resonance frequency is increased to achieve higher resolution, then the display resolution is improved, but the laser modulation frequency must be increased which is difficult to achieve
Solution Approach 1:
The patent introduces an intermediary addressing system that decouples the relationship between mirror oscillation frequency and laser modulation frequency. The pixel address table and position determination unit act as intermediaries, allowing the system to achieve high resolution through increased mirror oscillation while maintaining a manageable laser modulation frequency. This intermediary layer resolves the contradiction by breaking the direct frequency coupling.
Solution Approach 2:
The patent segments the resolution achievement into two independent components: mirror oscillation parameters (controlling spatial resolution) and laser modulation frequency (controlling temporal sampling). By separating these functions, the system can optimize mirror oscillation for high resolution without being constrained by laser modulation frequency limitations.
3Productivity
If the frame frequency is expanded to cope with high resonance frequency, then the productivity is improved, but the pixel address distribution becomes uneven causing missing pixels
Solution Approach 1:
The patent implements feedback by continuously monitoring actual mirror scanning positions and using this information to adjust pixel address assignment. The position determination unit provides feedback on real-time mirror location, and the pixel address table uses this feedback to ensure uniform pixel distribution even at expanded frame frequencies. This feedback loop prevents missing pixels while maintaining high productivity.
Solution Approach 2:
The patent applies preliminary action by pre-calculating and storing optimal pixel address mappings in the pixel address table before scanning occurs. This pre-computed addressing scheme anticipates position variations and ensures uniform pixel distribution is maintained even when frame frequency is expanded. The preliminary preparation of address mappings prevents pixel distribution issues.
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
The solution enables high-resolution displays with consistent luminance and pixel distribution, effectively addressing issues of pixel unevenness and missing pixels, while accommodating increased frame frequencies and angles of view.
Implementation Method 1
the method of modulating light intensity of the beam in accordance with the video information adapted to the beam scanning position by means of the micro-mirror which oscillates with resonance (horizontal direction) and dissonance (vertical direction) through a MEMS (Micro Electro Mechanical System) element
Implementation Method 2
modulating light intensity of the beam in accordance with the video information adapted to the beam scanning position
Data Source
AI summary
The purpose of the present invention is to provide a laser scanning display device capable of achieving high-resolution projection display while ensuring that the luminance and the size of the pixels are uniform to maintain the quality of the projection display. The scanning display device is configured to apply noise from a dither noise generator (21) to a horizontal scanning position on an oscillating mirror (11,12) determined by a scanning position determination unit (13); normalize the horizontal scanning position to which the noise was applied using a normalizing unit (22); acquire a pixel address corresponding to the normalized horizontal scanning position by referring to a pixel address table (23); read pixel data corresponding to the pixel address from an image memory (14); and modulate laser light by driving a light source (17) for emitting the laser light.