Dual Prism Optical Image Stabilization for Slim Camera Design

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Solution Overview

Problem

Existing camera systems face challenges in accurately performing optical image stabilization (OIS) for dual prisms caused by camera shake, particularly due to hand tremors, which affects image quality and requires complex lens movements that complicate slim camera design.

Innovation Solution

A prism apparatus with independently rotating dual prisms, each with its own actuator and hall sensor, adjusts angles based on control signals to compensate for movement, allowing for precise optical image stabilization and enabling a slim camera design by intersecting the prisms' optical paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dual prism is used for optical image stabilization, then image quality is improved, but device complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical image stabilization system is segmented into two independent prism units, each with its own actuator and control mechanism. The first prism handles stabilization in one direction while the second prism handles the perpendicular direction, dividing the complex stabilization task into manageable independent segments that can be controlled separately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The prisms are designed to be rotatable about their respective rotation axes, allowing dynamic adjustment of the optical path in real-time. This dynamic capability enables the system to compensate for camera shake in multiple directions simultaneously, improving image stabilization effectiveness while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #15Dynamics

2Reliability

If lens movement is used for optical image stabilization, then image quality is improved, but camera thickness increases

Engineering Contradiction:
Improveimage qualityVSAvoidcamera thickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent replaces the traditional mechanical lens movement system with a rotational prism system. Instead of moving the lens assembly to compensate for camera shake, the prisms rotate about their axes to redirect the optical path, achieving the same image stabilization effect without requiring the space needed for lens movement mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The stabilization mechanism transitions from one-dimensional lens movement to two-dimensional prism rotation. By allowing prisms to rotate about perpendicular axes, the system achieves stabilization in multiple directions simultaneously within a compact footprint, eliminating the need for thick lens movement mechanisms.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If dual prism rotation is implemented, then optical image stabilization accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveoptical image stabilization accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control system is segmented into independent control channels for each prism, with each actuator receiving and processing control signals independently. This segmentation allows for precise control of each prism's rotation angle and speed, improving stabilization accuracy while keeping the control architecture manageable through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback control where the rotation angles of both prisms are monitored and adjusted based on real-time performance requirements. Control signals are generated and applied to the actuators based on detected camera shake, creating a closed-loop system that continuously optimizes stabilization accuracy.

Inventive Principle:
Principle #23Feedback

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 solution enhances the accuracy of optical image stabilization, reduces the thickness of cameras, and improves image quality by compensating for camera shake without increasing the camera's size, enabling efficient motion compensation regardless of lens zoom levels.

Implementation Method 1

a first prism configured to reflect input light toward a first reflected direction

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a second prism configured to reflect the light reflected from the first prism toward a second reflected direction

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a first actuator configured to change an angle of the first prism about a first rotation axis to change the first reflected direction based on a first control signal

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 4

a second actuator configured to change an angle of the second prism about a second rotation axis to change the second reflected direction based on a second control signal

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Data Source

PatentEP3777123B1Prism apparatus, and camera apparatus including the same
Publication Date: 2024.05.15 LG ELECTRONICS INC
  • EP3777123B1 patent drawingFigure 1a
  • EP3777123B1 patent drawingFigure 1b
  • EP3777123B1 patent drawingFigure 2

AI summary

A prism apparatus, and a camera and an image display apparatus including the same are disclosed. The prism apparatus includes: a first prism configured to reflect input light toward a first reflected direction, a first actuator configured to change an angle of the first prism about a first rotation axis to change the first reflected direction based on a first control signal, a second prism configured to reflect the light reflected from the first prism toward a second reflected direction, and a second actuator configured to change an angle of the second prism about a second rotation axis to change the second reflected direction based on a second control signal.