Projection Optical Actuator Waveform Feedback for Stable Pixel Shifting

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Solution Overview

Problem

Conventional projector driving devices for pixel shift actuators lack real-time adjustment capabilities, leading to excessive vibration and noise due to image pixel displacement variations caused by mechanical and environmental factors, which are not compensated for after factory calibration.

Innovation Solution

A closed-loop system is implemented with a driving device that includes a sensor, a driving waveform signal generator, and a control element to dynamically adjust the driving waveform based on position feedback, ensuring the maximum amplitude in the initial period is less than or equal to that in the stable period, stabilizing the optical path shift element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the output value is directly set to equal the target value in an open-loop design, then the device complexity is reduced, but the positional stability of the optical path shift element deteriorates due to lack of real-time compensation

Engineering Contradiction:
Improvedriving device structureVSAvoidpositional stability of optical path shift element
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent implements a closed-loop control system where a sensor detects the actual position of the optical path shift element and feeds back position information to a control element. The control element compares the actual position with the target position and dynamically adjusts the driving waveform signal to compensate for deviations, thereby maintaining positional stability without requiring overly complex mechanical structures.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically changes the parameters of the driving waveform signal (amplitude, frequency, phase) based on real-time position feedback. The control element adjusts these parameters to optimize the actuator's response and maintain stable positioning, resolving the contradiction between simple device structure and stable positioning performance.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the actuator is driven with full amplitude signal from the start, then the productivity is improved by reducing settling time, but harmful factors increase due to excessive vibration and collision noise

Engineering Contradiction:
Improvesettling timeVSAvoidvibration and collision noise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by using a ramp-up approach where the driving signal amplitude is gradually increased from zero to the target amplitude over an initial period. This preliminary gradual excitation prevents sudden large vibrations and collisions, and the control element monitors position feedback to ensure smooth transitions before full-amplitude operation begins.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent divides the driving process into distinct periodic phases: an initial period with gradually increasing amplitude to avoid sudden vibrations, and a stable period with full amplitude for efficient operation. This periodic structure allows the system to balance productivity and harm reduction by controlling vibration characteristics in different time phases.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4593371A1Driving device, projection device and driving method thereof
Publication Date: 2025.07.30 CORETRONIC CORPORATION
  • EP4593371A1 patent drawingFigure 1
  • EP4593371A1 patent drawingFigure 2
  • EP4593371A1 patent drawingFigure 3A~3B

AI summary

A driving device and a driving method are provided. The driving device includes a driving waveform signal generator and a control element. The driving waveform signal generator is configured to provide a driving waveform signal to an optical actuator according to waveform information provided by the control element. The control element is configured to generate updated waveform information based on a synchronization signal and the position information received from the sensor. The driving waveform signal generator provides an updated driving waveform signal to the optical actuator according to the updated waveform information, so that a maximum amplitude value of the driving waveform signal in an initial period is less than or equal to a maximum amplitude value of the driving waveform signal in a stable period.