Gaze Tracking With Synchronized Reference Light Sources
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gaze tracking systems, particularly intrusive and portable types, are not suited for determining the direction of gaze on mobile objects like mobile phones in a context of mobility, as the screen becomes mobile in the video flow, making it difficult to automatically track the user's area of interest.
Innovation Solution
A system that positions reference light sources in the same plane as the mobile phone screen and uses a scene camera fixed relative to the phone, along with a wearable camera setup, to maintain the screen's position in the video frame, allowing synchronization of light sources with the video signal to accurately determine the gaze direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a scene camera is used to film the observed scene while the user is in motion, then the user's freedom of movement is maintained, but the screen becomes mobile within the video flow, making it difficult to automatically determine the user's area of interest
Solution Approach 1:
The patent introduces a second camera fixed to the mobile device that films the screen in the device's frame of reference. This second camera acts as an intermediary to capture the screen position independently of the user's movement. By combining the scene camera video flow with the second camera's screen recording, the system can determine the user's area of interest despite the screen's mobility within the video flow.
2Device complexity
If the light source illumination is not synchronized with the video signal capture, then the system operation is simpler, but the determination of gaze direction becomes inaccurate due to ambient light interference
Solution Approach 1:
The patent implements periodic illumination of the light source synchronized with the video signal capture. The light source is activated only during specific time intervals when the camera captures the video signal, creating a periodic action that eliminates ambient light interference. This synchronization ensures that only the reflected light from the light source is captured, improving the accuracy of Purkinje point detection and gaze direction determination.
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
Enables easy and automatic tracking of the user's gaze on a mobile phone screen during mobility by maintaining the screen's position in the video frame and synchronizing light sources with the video signal, improving the accuracy of determining the user's area of interest.
Implementation Method 1
This principle involves placing an infrared LED (light-emitting diode) as the light source, positioned next to the lens of a video camera designed to capture images of the eye. This infrared LED emits light towards the eye in the same direction as the axis of the video camera lens. This light is reflected off the cornea of the eye: a bright spot, called a 'Purkinje point,' then appears on the image of the cornea captured by the video camera.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
One aspect of the invention relates to a device (10) for supporting, in motion, a mobile terminal (20) having a display surface (21), such as a mobile phone or a similar object. The invention is characterised in that it comprises: a supporting element (11) forming a hand grip for the device; and a plate (12) mounted such that it can move in relation to the supporting element (11), said plate (12) forming a housing that is intended to receive the mobile terminal in the use position, in which the display surface (21) can be observed by a user. The device comprises a plurality of reference light sources (16a, 16b, 16c, 16d) linked to the supporting element (11), which can emit light towards the user's eye and which are disposed in the environment of the housing in a two-dimensional array coplanar with the display surface (21) of the mobile terminal that is intended to be received in the housing.