Head-Mounted Display Flexible Circuit Stiffener Mass Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Head-mounted displays often cause user discomfort due to the mass and distribution of their components, leading to perceived weight and discomfort during use.
Innovation Solution
The design incorporates a housing with two display modules, each featuring a display, a lens, and an illuminator with a flexible circuit and a stiffener laminated with one or fewer layers of adhesive, allowing for reduced mass and shifted center of gravity for improved comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional rigid circuit boards and multiple adhesive layers are used to couple the lens to the display, then structural stability is improved, but device mass increases and center of gravity distribution worsens
Solution Approach 1:
The patent replaces traditional rigid circuit boards with flexible circuits that have integrated stiffeners. The flexible circuit substrate provides the necessary mechanical support while being significantly thinner and lighter than conventional rigid boards, directly reducing device mass while maintaining structural stability through the stiffener integration.
Solution Approach 2:
The patent combines multiple separate components (circuit board, stiffener, adhesive layers) into a single integrated flexible circuit assembly. This merging eliminates the need for multiple discrete adhesive layers and reduces the overall number of components, thereby reducing total mass while maintaining the structural stability function.
2Strength
If multiple adhesive layers and separate stiffener components are used, then bonding strength is improved, but device complexity increases
Solution Approach 1:
The patent integrates the stiffener directly into the flexible circuit structure, creating a single unified component rather than separate stiffener and circuit board assemblies. This integration maintains the necessary mechanical strength while significantly reducing device complexity by eliminating multiple discrete components and their associated assembly steps.
Solution Approach 2:
The patent extracts the stiffening function from a separate component and integrates it directly into the flexible circuit substrate. This extraction and integration approach maintains bonding strength requirements while simplifying the overall device structure by reducing the number of separate parts that need to be assembled and managed.
3Measurement precision
If traditional lens coupling methods are used, then optical alignment precision is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces the flexible circuit with integrated stiffener as an intermediary structure between the lens and display. This intermediary provides a compliant mounting surface that can accommodate minor manufacturing variations while maintaining optical alignment precision, thereby reducing the stringency of manufacturing precision requirements.
Solution Approach 2:
The patent changes the mechanical properties of the coupling structure by using a flexible circuit substrate with integrated stiffeners. This parameter change allows the structure to provide both structural support and compliance, enabling optical alignment precision to be maintained while reducing the need for extremely tight manufacturing tolerances.
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 user discomfort by minimizing the perceived weight and improving the distribution of mass within the head-mounted display, enhancing user comfort during extended wear.
Implementation Method 1
a lens for refracting the light output by the display
Implementation Method 2
a stiffener laminated to the flexible circuit with one or fewer layers of adhesive
Data Source
AI summary
A head-mounted display a housing, two display modules, and a head support. The two display modules ae coupled to the housing. Each of the two display modules includes a display for outputting light that forms graphical content, a lens for refracting the light output by the display, and an eye illuminator. The eye illuminator includes a light-emitting diode, a flexible circuit to which the light-emitting diode is coupled, and a stiffener laminated to the flexible circuit with one or fewer layers of adhesive. The lens is removably coupled to the display indirectly by the stiffener. The head support is coupled to the housing for supporting the housing on a head of a user with the two display modules positioned to provide the graphical content to eyes of the user.