VR Headset Wedge Lens for Eye Tracking Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing VR technologies face difficulties in accurately acquiring an infrared image of a user's eye due to structural constraints within VR head-mounted apparatuses, affecting biometric recognition and eye tracking.
Innovation Solution
A VR head-mounted apparatus incorporating a convex lens and a partial-reflection partial-transmission lens that reflects infrared light obliquely to a camera, minimizing distortion and improving image acquisition accuracy, while allowing visible light to pass through unaffected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional camera setup is used in VR apparatus, then the structure is simple, but the infrared image acquisition accuracy is poor due to structural constraints
Solution Approach 1:
An infrared reflective lens is introduced as an intermediary component between the user's eye and the camera. This lens reflects infrared light at a specific angle (e.g., 45 degrees) to redirect it toward the camera, enabling accurate infrared image acquisition without requiring the camera to be positioned directly in line with the eye. This mediator component resolves the structural constraint problem while maintaining system feasibility.
Solution Approach 2:
The optical system utilizes angular dimension by positioning the infrared reflective lens at an oblique angle (e.g., 45 degrees) relative to the camera axis. This allows the camera to capture infrared images from a different spatial dimension, avoiding direct interference with the user's forward view through the display lens while still achieving accurate eye imaging.
2Measurement precision
If the camera is positioned to directly capture the eye, then the image acquisition is straightforward, but it blocks the user's view of the VR display
Solution Approach 1:
The infrared reflective lens is designed with wavelength-selective properties, being highly reflective for infrared light (780-1500nm) while being transparent or low-reflection for visible light (380-780nm). This local quality differentiation allows the lens to serve dual functions: capturing infrared eye images accurately while simultaneously allowing the user to view the VR display content without obstruction.
Solution Approach 2:
The system separates the optical paths for different wavelengths by using an oblique reflection angle. The infrared light path is redirected at an angle (e.g., 45 degrees) toward the camera, while visible light passes through the lens to the user's eye. This dimensional separation in the optical path ensures that infrared image capture does not interfere with the user's viewing experience.
3Measurement precision
If an infrared reflective lens is added to improve image acquisition, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The infrared reflective lens serves multiple functions simultaneously: (1) It acts as an infrared mirror to redirect eye reflection toward the camera for accurate imaging; (2) It allows visible light to pass through to maintain the user's VR display viewing; (3) It is positioned outside the user's direct viewing area to avoid blocking the display. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
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
Enhances the accuracy and precision of infrared image acquisition, reducing deformation and distortion, and enabling effective eye tracking and iris recognition without interfering with the user's VR experience.
Implementation Method 1
a lens surface of the partial-reflection partial-transmission lens may be disposed obliquely to reflect an infrared image of an eye of the user to the first camera
Implementation Method 2
the partial-reflection partial-transmission lens may include an infrared dichroic mirror
Data Source
AI summary
Methods, systems, and apparatus for a virtual reality (VR) head-mounted apparatus are provided. One of the apparatus includes a convex lens, a camera and a partial-reflection partial-transmission lens. The partial-reflection partial-transmission lens is located on a side of the convex lens towards a user when the user wears the VR head-mounted apparatus, and a lens surface of the partial-reflection partial-transmission lens is disposed obliquely to reflect an infrared image of an eye of the user to the camera. The VR head-mounted apparatus improves the acquisition accuracy for an infrared image of an eye of the user.