Electronic Viewfinder Power Management via Eye and Sight Line Detection

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Solution Overview

Problem

Existing display control techniques for image capture apparatuses, such as digital cameras, fail to effectively combine eye approach detection and sight line detection functions to achieve a high power-saving effect, particularly when the camera is not in use, leading to unnecessary power consumption.

Innovation Solution

A method and apparatus that utilize eye approach detection and sight line detection functions to control the display of an electronic viewfinder (EVF) and a backside display unit, switching between display states based on user interaction and sight line detection, thereby optimizing power usage by turning off displays when not in use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If eye approach detection is continuously performed to enable quick display activation, then response speed is improved, but power consumption increases

Engineering Contradiction:
Improveresponse speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent dynamically adjusts the eye approach detection mode based on current state: using infrared detection when EVF is off (high responsiveness needed), and optical detection when EVF is on (lower power mode). This dynamic switching resolves the contradiction by adapting detection intensity to actual needs.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements periodic detection with different intervals: frequent infrared detection when EVF is off to quickly detect eye approach, and less frequent optical detection when EVF is on. This periodic action with variable frequency resolves the contradiction between continuous monitoring and power saving.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the electronic viewfinder continues to operate after eye approach detection to ensure user experience, then reliability is improved, but power consumption increases

Engineering Contradiction:
Improveuser experienceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses feedback from sight line detection to control EVF operation. When sight line is detected, EVF continues operating to ensure user experience. When sight line is not detected for a threshold period, EVF transitions to power save mode. This feedback mechanism resolves the contradiction by using detection information to intelligently control operation duration.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system automatically adjusts its own operation state based on detected conditions. The EVF autonomously transitions between active and power save modes based on sight line detection results, without requiring manual user intervention, thus resolving the contradiction between continuous operation and power saving.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the camera is carried on the neck with the viewfinder facing the user's body, then portability is improved, but false eye approach detection occurs leading to unnecessary power consumption

Engineering Contradiction:
ImproveportabilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces sight line detection as an intermediary verification step between eye approach detection and EVF activation. Even when eye approach is detected (which may be false due to neck carrying), the system checks for actual sight line before activating EVF. This intermediary mechanism resolves the contradiction by filtering false positives while maintaining portability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent performs preliminary sight line detection before activating the EVF, even when eye approach is detected. This preliminary check prevents false activation when the camera is carried on the neck, ensuring that EVF only activates when there is genuine intent to view, thus resolving the contradiction between portability and power consumption.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3761628B1Display control apparatus for an electronic viewfinder in a camera and control method thereof
Publication Date: 2023.12.13 CANON KK
  • EP3761628B1 patent drawingFigure 1A~1B
  • EP3761628B1 patent drawingFigure 2
  • EP3761628B1 patent drawingFigure 3A

AI summary

A display control apparatus comprises a first display unit capable of being viewed via an eyepiece part, a second display unit capable of being viewed without involving the eyepiece part, an eye approach detection unit configured to detect an eye approaching to the eyepiece part, a sight line detection unit configured to detect a sight line of the eye that is viewing the first display unit via the eyepiece part, and a control unit configured to perform control to stop display of the first display unit if a sight line is not detected by the sight line detection unit within a first time period in a state where an eye approaching is being detected by the eye approach detection unit.