Multi-Layer Camera Motion Photo-Sensor for Blur Reduction

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Solution Overview

Problem

Existing digital cameras face challenges in accurately detecting and estimating camera motion during image acquisition, which affects image quality due to motion blur, especially when using sensors like Foveon™ and CMOS, where charge integration varies non-linearly with camera movement.

Innovation Solution

A digital camera system employing a multi-layer sensor with p-type and n-type silicon layers and multiple camera motion photo-sensors to estimate camera movement by computing variance in photocurrent measurements, allowing for motion detection and compensation during exposure, and using a processor to analyze data from these sensors to reduce motion blur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a multi-layer photo-sensor is used to detect camera motion, then motion detection precision is improved, but device complexity increases

Engineering Contradiction:
Improvemotion detection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The photo-sensor is divided into multiple layers (first photo-sensor layer, second photo-sensor layer, third photo-sensor layer) with different light penetration depths. Each layer detects light at different depths, enabling precise measurement of camera motion by comparing charge variations across layers. This segmentation allows the system to achieve high motion detection precision while keeping each individual layer relatively simple in structure.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If multiple photocurrent measurements are performed during exposure, then motion estimation accuracy is improved, but loss of time increases

Engineering Contradiction:
Improvemotion estimation accuracyVSAvoidexposure time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs multiple photocurrent measurements continuously during the exposure period without interrupting the image capture process. The first, second, and third photocurrent measurements are taken at different times within the exposure duration, allowing motion estimation to be performed continuously alongside image acquisition. This eliminates the need for separate measurement phases and prevents time loss.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The camera motion photo-sensors perform preliminary motion detection during the exposure period before the main image processing occurs. By estimating camera motion in advance during exposure, the system can apply motion compensation to the captured image, improving motion estimation accuracy without adding post-processing time.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If camera motion is detected during image acquisition, then image quality is improved, but device complexity increases

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

Solution Approach 1:

The camera motion photo-sensors are integrated with the main imaging sensor array, sharing the same physical structure and readout circuitry where possible. The multi-layer photo-sensor structure is combined with the standard imaging pixels, allowing motion detection and image capture to occur simultaneously using a unified device architecture. This merging reduces the need for completely separate motion detection hardware.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-layer photo-sensor structure serves multiple functions: it acts as both the main imaging sensor for capturing images and as a camera motion sensor for detecting camera movement. The same physical layers that detect light for image formation also detect motion by measuring charge variations, eliminating the need for dedicated separate sensors and reducing overall 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 system effectively detects and compensates for camera motion, reducing motion blur in captured images by accurately estimating camera movement and synchronizing the main imaging sensor with the motion sensor, resulting in improved image quality.

Implementation Method 1

A camera motion photo-sensor includes a multi-layer photo-sensor having successive wells of known depths of p-type and n-type silicon layers... The camera motion photo-sensor estimates camera motion during an exposure period by measuring photocurrents of the multi-layer photo-sensor

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

Lights with different wavelengths have different depths of penetration in the silicon of a photo-detector... The photon flux generally decays exponentially with distance from surface

Methodology Applied
Scientific EffectLight Absorption in Silicon: Absorption (EM radiation)

Data Source

PatentEP2149108B1Detection and estimation of movement in a camera
Publication Date: 2015.02.25 FOTONATION LIMITED
  • EP2149108B1 patent drawingFigure 1A~1B
  • EP2149108B1 patent drawingFigure 2~3
  • EP2149108B1 patent drawingFigure 4A~5

AI summary

A digital camera includes an optical system, a main image sensor and a camera motion sensor for estimating relative camera-object motion during image capture. A processor estimates camera motion based on information obtained by the camera motion photo-sensor while the camera is exposed to an image of a scene. The processor reduces or removes a motion blur effect from the main image permitting a processed version of the main image to be thereafter rendered.