Projection Device Image Rotation Mechanism

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Solution Overview

Problem

Virtual reality projection devices face challenges in comprehensively adjusting projection images to overlap two virtual images for stereoscopic viewing, as traditional adjustment methods affect incident light energy rather than moving the image itself, leading to dark or distorted images.

Innovation Solution

A projection device with an adjusting structure that includes a base and adjusting elements allowing the projection module and reflecting element to rotate along specific axes, enabling comprehensive movement and rotation of the projection image, ensuring accurate overlap and clear stereoscopic vision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the projection device moves horizontally and vertically, then the incident light energy is affected, but the image of the angle space distribution does not move accordingly and becomes dark

Engineering Contradiction:
Improvebrightness of projection imageVSAvoidadjustment of projection image position
Core Design Contradiction:
Illumination intensityVSEase of operation

Solution Approach 1:

The patent divides the adjustment function into two independent parts: (1) adjusting the incident light energy to control brightness, and (2) adjusting the angle of incident light to control image position. This segmentation allows each function to be optimized independently without compromising the other.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a rotating component that can dynamically adjust the angle of the incident light beam relative to the waveguide sheet. This dynamic adjustment mechanism enables the projection image position to be changed without affecting the brightness, as the light energy incidence remains optimized while only the angle varies.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the projection device rotates horizontally or vertically, then the projection image becomes a trapezoid, but the image cannot be properly adjusted for stereoscopic viewing

Engineering Contradiction:
Improveadjustment of projection image orientationVSAvoidshape of projection image
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

Instead of rotating the entire projection device which causes trapezoidal distortion, the patent inverts the approach by rotating only the incident light beam angle relative to the waveguide sheet. This selective rotation adjusts the projection image orientation without causing geometric distortion, as the light enters the waveguide at the correct angle for maintaining image shape.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies local adjustment by rotating only the light incident angle at the waveguide interface rather than rotating the entire projection device. This localized adjustment maintains the overall device stability and optical path geometry, preventing trapezoidal distortion while achieving the necessary image orientation adjustment for stereoscopic viewing.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If traditional adjustment methods are used, then the device structure is simple, but the projection image cannot be comprehensively adjusted for accurate overlap of virtual images

Engineering Contradiction:
Improvecomprehensive adjustment capability of projection imageVSAvoidstructure of projection device
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the brightness control function and position control function into a unified optical adjustment system. By merging these functions into the light incident angle adjustment mechanism, the system achieves comprehensive adjustment capability without requiring separate independent systems, thus limiting the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotating component designed to adjust the light incident angle serves multiple functions simultaneously: it controls the horizontal position of the projection image, controls the vertical position, and maintains proper image orientation for stereoscopic viewing. This multi-functionality achieves comprehensive adjustment capability without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 allows for precise horizontal and vertical movement and rotation of the projection image, effectively adjusting the projection to ensure clear, overlapping stereoscopic images are presented to the user's eyes.

Implementation Method 1

The reflecting element is disposed between the at least one projection module and the projection target and located on the optical axis and has a reflecting surface. The reflecting surface is adapted to reflect the projection beam to the projection target.

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

an image beam projected from the projection device is incident into a waveguide sheet for continuous total internal reflection and propagates forward

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3502778B1Projection device
Publication Date: 2022.01.12 CORETRONIC CORPORATION
  • EP3502778B1 patent drawingFigure 1
  • EP3502778B1 patent drawingFigure 2
  • EP3502778B1 patent drawingFigure 3

AI summary

A projection device including at least one projection module, at least one reflecting element, and at least one adjusting structure is provided. The projection module has at least one optical axis. The projection module is adapted to provide a projection beam. The projection beam is transmitted along a light transmission path to a projection target to form a projection image. The reflecting element is disposed between the at least one projection module and the projection target and located on the optical axis and has a reflecting surface, wherein the reflecting surface is adapted to reflect the projection beam to the projection target. The adjusting structure is connected to the projection module and the reflecting element. The adjusting structure is adapted to drive the projection module and the reflecting element to rotate along a second axis such that the projection image rotates.