Viewfinder Unit Line-of-Sight Detection with Nested Illumination
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Solution Overview
Problem
Existing camera systems with line-of-sight detection functions face challenges in integrating infrared LEDs for eye detection without increasing the size of the viewfinder unit, while maintaining effective illumination and detection capabilities.
Innovation Solution
The viewfinder unit incorporates a display unit, an eyepiece portion, an optical member, an illumination device, a sensor, and a detector, with the illumination device and detector located in the same plane orthogonal to the optical axis, and the illumination device positioned inside an opening wider than the display area, allowing for efficient line-of-sight detection without obstructing the display or increasing the unit's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If infrared LEDs are placed outside the viewfinder opening to enable line-of-sight detection, then detection function is achieved, but the viewfinder unit size increases and the infrared LEDs may be visually recognized by the photographer
Solution Approach 1:
The infrared LEDs are nested inside the viewfinder opening, positioned within the optical path structure rather than outside. The illumination device is integrated into the existing viewfinder housing, with the infrared LEDs arranged to project through the optical member without requiring external placement, thus eliminating the need to increase the viewfinder unit size.
Solution Approach 2:
The optical member acts as an intermediary that guides the infrared light from the LEDs positioned inside the viewfinder opening to the photographer's eye. The optical member transmits the infrared illumination effectively while the infrared LEDs remain concealed within the viewfinder structure, preventing visual recognition by the photographer.
2Reliability
If infrared LEDs are placed outside the viewfinder opening, then line-of-sight detection is enabled, but the infrared LEDs may be visually recognized by the photographer
Solution Approach 1:
The optical member serves as an intermediary that transmits infrared light from the LEDs to the photographer's eye while the LEDs themselves remain hidden inside the viewfinder opening. This intermediary structure allows the infrared illumination to reach the eye without the LEDs being visually recognizable to the photographer.
Solution Approach 2:
The infrared LEDs are positioned at specific locations inside the viewfinder opening where they can effectively illuminate the eye through the optical member while remaining concealed. The local arrangement of LEDs within the optical path structure allows them to perform their function without being visible to the photographer.
3Ease of operation
If the viewfinder opening is made wider than the display area, then the illumination device can be positioned inside the opening without obstructing the display, but the structural complexity increases
Solution Approach 1:
The viewfinder opening is designed to serve multiple functions: it allows the display area to be viewed, accommodates the infrared LEDs for line-of-sight detection, and provides space for the illumination device. By making the opening wider than the display area, a single structural feature achieves multiple objectives without requiring separate components or complex arrangements.
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 configuration enables accurate line-of-sight detection while minimizing the viewfinder unit's size, ensuring effective eye illumination and detection without visual recognition of the infrared LEDs by the photographer.
Implementation Method 1
a plurality of infrared LEDs outside a viewfinder opening of an eyepiece portion and uses the infrared LEDs to illuminate an eyeball of a user who looks into the viewfinder
Implementation Method 2
illuminate an eye of a photographer with predetermined light
Implementation Method 3
a line-of-sight sensor and to obtain a position where the user is looking by performing computations on the two types of images
Implementation Method 4
an optical member provided between the display unit and the eyepiece portion
Implementation Method 5
detect a user's eyeball image and conical reflection images of the infrared LEDs, formed by specular reflection from a cornea
Data Source
AI summary
A viewfinder unit includes an optical member between a display and an eyepiece, a first member holding the optical member in a direction orthogonal to an optical axis of the optical member, an illuminator, a second member holding the illuminator, a sensor picking up a photographer's eye image, a detector detecting proximity of the eye to the eyepiece, and an opening wider than a display area of the display in the optical axis direction. When the eyepiece is viewed in the optical axis direction, the illuminator is inside the opening and outside the display area. Part of a first area of the optical member, projecting from an outline of the first member in the optical axis direction, is inside the opening in the orthogonal direction, and at least one of the illuminator and the second member is in a second area surrounded by the outline and the first area.