Projector Distortion Correction with Vibration Filtering

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Solution Overview

Problem

Recent projector devices often degrade image quality due to unnecessary trapezoidal distortion correction caused by vibrations, especially when the user operates the device, as they constantly update the projection image based on detected inclination angles, including those from minor vibrations.

Innovation Solution

A projector device with a distortion corrector that detects the inclination angle using an accelerometer and only performs correction when the angle exceeds a predetermined minimum value, and temporarily halts corrections during user operation to prevent unnecessary adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the projector device performs distortion correction based on accelerometer output signals, then trapezoidal distortion is corrected, but image quality degrades due to unnecessary corrections from vibrations

Engineering Contradiction:
Improvedistortion correction accuracyVSAvoidimage quality stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the parameter threshold for triggering distortion correction by introducing a minimum angle threshold (e.g., 0.5 degrees). The distortion correction is only performed when the detected inclination angle exceeds this threshold, filtering out minor vibrations that would otherwise cause unnecessary corrections and image quality degradation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic control of the distortion correction function based on the magnitude of detected vibrations. The system dynamically adjusts whether to perform correction based on real-time accelerometer readings, enabling the correction function to be activated only when necessary (during significant tilting) and deactivated during normal operation or minor vibrations.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the projector device constantly updates the projection image based on detected inclination angles, then distortion correction is maintained, but the frequency of corrections increases during user operation

Engineering Contradiction:
Improvedistortion correction maintenanceVSAvoidcorrection update frequency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent modifies the update frequency parameter of distortion correction based on the operational context. During user operation (when buttons are pressed or sliders are moved), the system changes the update frequency to a lower value or suspends updates temporarily, reducing the number of corrections performed during interaction while maintaining corrections during normal projection.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic adjustment of the correction update frequency based on system state. The update frequency is high during normal projection to maintain correction accuracy, but is reduced or suspended during user operation to prevent excessive updates caused by handling vibrations, thus adapting the system behavior to current operational needs.

Inventive Principle:
Principle #15Dynamics

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 reduces the frequency of distortion corrections, thereby maintaining image quality by avoiding unnecessary updates and minimizing the impact of user-induced vibrations on the projection image.

Implementation Method 1

the projector device detects an inclination angle of the projector device using an accelerometer

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP2590019B1Projector device, distortion correction method, and distortion correction program
Publication Date: 2018.09.19 RICOH CO LTD
  • EP2590019B1 patent drawingFigure 1
  • EP2590019B1 patent drawingFigure 2A~2D
  • EP2590019B1 patent drawingFigure 3A~3B

AI summary

A projector device (1), a method of correcting trapezoidal distortion, and a distortion correction program stored in a recording medium are provided, each of which projects an image onto a projection surface, detects inclination of the projector device (1) with respect to a horizontal surface to output an inclination angle value (X) of the projector device (1), corrects trapezoidal distortion in an image to be projected based on the inclination angle value (X), determines whether an operation device (60) of the projector device (1) is being operated by a user to generate a determination result, and prohibits the projector device (1) from performing trapezoidal distortion correction when the determination result indicates that the operation device (60) is being operated by the user.