TIR Suppression Bracket for Head Mounted Device Camera
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current camera modules in head-mounted devices, such as AR and VR headsets, face challenges in accurately imaging facial gestures due to optical noise and dust interference, which can result in ghost images and reduced accuracy in capturing lower face region details like lips, chin, and nose.
Innovation Solution
Incorporating a lower-face imaging camera module with a total internal reflection (TIR) suppression bracket angled to prevent ghost images and an energy-absorbing mechanical structure to secure the image sensor and lens assembly, along with non-visible light sources for illumination, allowing for precise imaging of facial gestures by focusing on near-infrared wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a camera module is used to capture facial gestures in head-mounted devices, then image capture capability is provided, but optical noise and dust interference cause ghost images and reduced imaging accuracy
Solution Approach 1:
The patent introduces a bracket as an intermediary component positioned between the camera module and the environment. This bracket serves multiple functions: it physically blocks dust from contacting the camera lens and image sensor, and it suppresses total internal reflection (TIR) of light that causes ghost images. By placing this intermediary structure, the harmful factors of dust and optical noise are prevented from reaching the camera module, thereby improving facial gesture detection accuracy without compromising the camera's imaging capability
Solution Approach 2:
The patent extracts and removes the harmful elements (dust particles and reflected light rays) from the optical path. The bracket design specifically targets and eliminates dust interference by creating a protective barrier, and removes ghost image interference by blocking the path of internally reflected light. This extraction of harmful factors allows the camera module to capture clear images of facial gestures without degradation
2Adaptability or versatility
If the camera module is exposed to the environment for imaging, then facial gesture capture is enabled, but dust can contact the camera components causing degradation
Solution Approach 1:
The bracket acts as a protective intermediary that allows the camera module to remain exposed for imaging while preventing dust contact. The bracket is positioned to create a protective barrier around the camera lens and sensor area, enabling the camera to maintain its imaging capability for facial gestures while the bracket reliably blocks environmental dust particles from reaching and degrading the sensitive camera components
Solution Approach 2:
The patent implements protective measures beforehand by installing the bracket before dust contamination can occur. The bracket is pre-positioned to block dust particles from contacting the camera module, providing advance protection against potential degradation. This prior cushioning ensures the camera components remain clean and functional throughout the device's operation
3Illumination intensity
If total internal reflection occurs in the camera module, then light paths are created, but ghost images are generated reducing image quality
Solution Approach 1:
The patent converts the harmful effect of total internal reflection (which creates ghost images) into a beneficial outcome by using the bracket to strategically block these reflected light paths. The bracket is designed to intercept and block the specific angles of internally reflected light that would otherwise create ghost images, while still allowing the primary light paths needed for imaging to pass through. This transforms the problematic TIR phenomenon into an opportunity for improved image clarity
Solution Approach 2:
The bracket extracts and removes the harmful reflected light rays from the optical system. By positioning the bracket to block specific light paths where total internal reflection occurs, the patent extracts the ghost image-causing light rays from the system, preventing them from reaching the image sensor. This leaves only the clean, direct light paths that produce clear images of facial gestures
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
The solution effectively reduces optical noise, prevents dust from contacting the camera, and enhances the accuracy of facial gesture detection by providing a clear field of view for the lower face region, enabling precise interaction and control in virtual environments.
Implementation Method 1
A total internal reflection (TIR) suppression bracket is included in the head mounted device where the TIR suppression bracket is angled with respect to the transparent cover to reflect image light incident onto the TIR suppression bracket at a reflection angle that exits the transparent cover without the transparent cover confining reflected image light by way of TIR
Implementation Method 2
a lens assembly and an image sensor. The lens assembly is configured to focus image light from a field-of-view (FOV) onto the image sensor
Data Source
AI summary
Devices and camera modules are configured for imaging facial gestures. The imaging may be directed at lower face imaging. The camera modules may be disposed along outside surfaces of devices such as head mounted devices to have a field of view that images a lower face region.