Compact Finger Navigation Device Using Diffractive Lens
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Solution Overview
Problem
Conventional finger navigation devices for electronic devices are too large to fit in smaller devices like cellular telephones, limiting their size reduction.
Innovation Solution
A finger navigation device with a compact design featuring a substrate with light source and photosensor chambers, a diffractive lens, and a transparent surface for finger movement tracking, allowing for reduced height and functionality similar to a computer mouse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional finger navigation devices are used, then navigation functionality is provided, but the device size becomes too large for smaller electronic devices
Solution Approach 1:
The patent replaces conventional mechanical navigation structures with an optical system consisting of a light source, diffractive lens, and photosensor. This substitution enables significantly reduced device dimensions while maintaining finger tracking capability, directly resolving the contradiction between small size and navigation functionality.
Solution Approach 2:
The patent transitions from two-dimensional surface navigation to three-dimensional optical field navigation by using a diffractive lens to manipulate light waves. This dimensional change in the optical field allows for compact integration of navigation components, reducing the overall device volume while preserving operational effectiveness.
2Length of stationary object
If the navigator is made smaller for electronic devices, then device size is reduced, but the navigation capability may be compromised
Solution Approach 1:
The patent changes the physical parameters of the optical system by using a diffractive lens with specific focal lengths and aperture ratios. These parameter optimizations enable accurate finger tracking within a compact form factor, resolving the contradiction between reduced device height and maintained tracking precision.
Solution Approach 2:
The diffractive lens serves as an intermediary element that converts finger position information into optical patterns detectable by the photosensor. This intermediary optical transformation enables precise measurement of finger movement despite the reduced size of the navigation device.
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 navigation in smaller electronic devices by utilizing diffracted light for finger tracking, allowing the device to be integrated into compact designs while maintaining functionality.
Implementation Method 1
The navigation device may have a light source and a diffractive lens
Implementation Method 2
A light source and a photosensor are located in different chambers
Data Source
AI summary
A finger navigation device is disclosed herein. An embodiment of the navigation device comprises a substrate; a light emitter located on the substrate; a photosensor located on the substrate; and a first cover located above the light emitter and the photosensor. The first cover has a first side and a second side, wherein the first side faces the substrate. A first lens is located in the first cover proximate the light emitter. An aperture is located in the first cover proximate the photosensor. A second cover faces the second side of the first cover and has a first surface proximate a transparent portion.