Electronic Imager Micro-Mirror Frequency Reduction
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Solution Overview
Problem
Existing electronic imagers generate luminous noise during data recording on photographic media due to excessive changes in micro-mirror positions, leading to decreased precision and quality of archived digital data.
Innovation Solution
The electronic imager reduces switching frequency of micro-mirrors from the typical 150 kHz to a range of 1 Hz to 100 kHz, allowing only 32, 128, or 16 distinct light levels, and incorporates an electronic shutter to block or turn off light during mirror changes, minimizing residual brightness and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the micro-mirrors switch at a high reference frequency (e.g., 150 kHz) to achieve fine brightness control with many levels (65,000 levels), then the brightness resolution is improved, but luminous noise increases due to excessive changes in mirror position, creating streaks of light that decrease precision during data recovery
Solution Approach 1:
The patent applies periodic action by using pulse-width modulation (PWM) to control micro-mirror switching. Instead of continuous high-frequency switching, the system uses periodic pulses with variable width to control brightness. The micro-mirrors switch between on and off states in periodic cycles, and the duty cycle of these pulses determines the average brightness level. This periodic approach reduces the number of actual state changes compared to continuous high-frequency switching while maintaining fine brightness control through duty cycle variation.
Solution Approach 2:
The patent implements preliminary action by performing a systematic reset of all micro-mirrors to a zero state before transitioning to the required brightness level. This preliminary reset ensures that all mirrors start from a known state, reducing unpredictable transitions and associated luminous noise. By pre-positioning mirrors in a standardized state before making necessary changes, the system minimizes unnecessary mirror movements that would generate noise during data recording.
2Measurement precision
If the micro-mirrors are systematically reset to zero state before each transition to achieve precise brightness levels, then the brightness control precision is improved, but the number of state changes increases, generating more luminous noise
Solution Approach 1:
The patent applies partial action by selectively resetting only those micro-mirrors that need to change state, rather than systematically resetting all mirrors before each transition. The system identifies which mirrors are currently in the desired state and only performs reset operations on mirrors that require state changes. This partial approach maintains brightness control precision for the necessary mirrors while reducing the total number of state changes across the entire mirror array, thereby reducing luminous noise.
3Object-generated harmful factors
If the switching frequency is reduced to decrease luminous noise, then the luminous noise is reduced, but the number of distinguishable brightness levels decreases
Solution Approach 1:
The patent applies parameter changes by transitioning from controlling brightness through switching frequency to controlling brightness through pulse width (duty cycle). Instead of using high switching frequency to achieve fine brightness levels, the system maintains a lower switching frequency and achieves fine brightness control by varying the width of the PWM pulses. This parameter change allows the system to maintain distinguishable brightness levels while operating at a lower frequency that generates less luminous noise.
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 approach significantly reduces luminous noise, improving data recording precision and enabling durable archiving of digital data on photographic media by minimizing off-state scattering and diffraction, resulting in higher image quality and longer data preservation.
Implementation Method 1
at least one matrix array of micro-mirrors each of which is suitable for reflecting, during a change in position, a light beam originating from at least one light source toward a projecting optical element
Implementation Method 2
incorporates an electronic shutter to block or turn off light during mirror changes, minimizing residual brightness and noise
Data Source
AI summary
An electronic imager (1) for imaging a photographic medium, comprising at least one array (6) of micromirrors (2), each of which is suitable for reflecting, during a change in position, a light beam coming from at least one light source (3) towards a projecting optical element (4), the change in position of the micromirrors (2) being controlled by a signal modulated at a toggling frequency (fb) of the micromirrors comprised between 1 Hz and 100 kHz.