Camera Module VCM Auto Focusing Posture Detection

Solution Overview

Problem

Conventional bi-directional VCMs in camera modules require significant time and current consumption for auto focusing due to displacement-dependent posture and non-driving sections, even when a driving signal is applied.

Innovation Solution

A camera module with a VCM that includes a posture detection sensor and an ISP to determine the rotor's posture and non-driving sections, skipping auto focusing in non-driving sections and performing it only in driving sections, using an optimized auto focus algorithm to reduce focusing time and current consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a bi-directional VCM is used to enable auto focusing by moving the rotor up and down, then the camera module can achieve auto focusing capability, but the rotor has displacement depending on posture and includes non-driving sections, causing increased auto focusing time and current consumption

Engineering Contradiction:

Improveauto focusing capabilityVSAvoidauto focusing time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs preliminary detection of the rotor's posture using a posture detection sensor before initiating the auto focusing operation. Based on the detected posture, the system pre-determines the non-driving section and adjusts the driving section accordingly, so that the auto focusing operation starts from the correct position without wasting time on sections that cannot be driven.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the driving section of the rotor based on the detected posture. The driving section is changed according to the posture-dependent non-driving section, making the auto focusing operation adaptive to different orientations rather than using a fixed driving range.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If a bi-directional VCM is used to enable auto focusing by moving the rotor up and down, then the camera module can achieve auto focusing capability, but the rotor has displacement depending on posture and includes non-driving sections, causing increased current consumption

Engineering Contradiction:

Improveauto focusing capabilityVSAvoidcurrent consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary detection of the rotor's posture using a posture detection sensor before initiating the auto focusing operation. Based on the detected posture, the system pre-determines the non-driving section and adjusts the driving section accordingly, so that the auto focusing operation starts from the correct position without wasting time on sections that cannot be driven.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of applying driving current across the entire rotor range, the system applies driving current only to the effective driving section that excludes the non-driving section. This partial action reduces unnecessary current consumption while still achieving the required auto focusing capability.

Inventive Principle:

Principle #16Partial or excessive action

3Device complexity

If auto focusing is performed without considering rotor posture and non-driving sections, then the auto focusing algorithm can be simple, but the system takes lots of time for auto focusing and consumes lots of current

Engineering Contradiction:

Improveauto focusing algorithm complexityVSAvoidauto focusing speed

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The system performs preliminary detection of the rotor's posture using a posture detection sensor before initiating the auto focusing operation. Based on the detected posture, the system pre-determines the non-driving section and adjusts the driving section accordingly, so that the auto focusing operation starts from the correct position without wasting time on sections that cannot be driven.

Inventive Principle:

Principle #10Preliminary action

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 significantly shortens auto focusing time and reduces current consumption by identifying and skipping non-driving sections, allowing for efficient and rapid auto focusing operations.

Implementation Method 1

a VCM (Voice Coil Motor) capable of adjusting a gap between an image sensor and a lens

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS9723198B2Camera module and auto focusing method of camera module

Publication Date: 2017.08.01 LG INNOTEK CO LTD

AI summary

A camera module and an auto focusing method of the camera module are provided, the camera module including a VCM (Voice Coil Motor) including a rotor including a lens distanced from a reference plane, in a case no driving signal is applied, a posture detection sensor determining a posture of the VCM; an ISP (Image Signal Processor) generating a driving signal for driving the VCM using an optimum focus value of the lens calculated by an auto focus algorithm in response to a posture of the VCM determined by the posture detection sensor, an image sensor changing lens-passed light to a digital signal, and a controller controlling the VCM, the posture detection sensor, the image signal processor and the image sensor.