Annular Fingerprint Assembly for Uniform Light Emission
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Solution Overview
Problem
Fingerprint assemblies with light emitting elements and light guide components face challenges in achieving a small size and uniform brightness due to the need for a space between them, leading to uneven brightness and increased size.
Innovation Solution
A fingerprint assembly design featuring a first and second circuit board enclosing an annular groove for an annular light emitting element, with a light guide aperture and reflection surfaces to evenly distribute light, using materials like light-transmitting plastic or glass, and incorporating a diffuser sheet for uniform emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a space is formed between the light emitting element and the light guide component, then light can reach each part of the receiving surface, but the fingerprint assembly size increases and brightness becomes uneven
Solution Approach 1:
The patent merges the light emitting element and light guide component by forming the light guide component's receiving surface directly on the circuit board where the light emitting element is mounted, eliminating the need for separate space between them. This integration allows light to reach all parts of the receiving surface without increasing assembly size.
Solution Approach 2:
The patent utilizes the circuit board as a three-dimensional structure to form the receiving surface of the light guide component, transitioning from a planar arrangement to a vertical integration. This dimensional change allows the light guide component to be positioned directly above the light emitting element while maintaining proper light distribution.
2Illumination intensity
If a space is formed between the light emitting element and the light guide component, then light can reach each part of the receiving surface, but the structure becomes more complex
Solution Approach 1:
The patent combines multiple functions into the circuit board: it serves as the mounting substrate for the light emitting element, the structural support for the light guide component, and the formation of the receiving surface. This merging reduces the number of separate components and simplifies the overall structure.
Solution Approach 2:
The circuit board is designed to perform multiple functions simultaneously: electrical connection, mechanical support, and optical function (forming the receiving surface). This multi-functionality reduces the need for additional components and simplifies the assembly structure.
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 design achieves uniform light emission and a smaller volume while maintaining a simple structure, ensuring even brightness across the assembly.
Implementation Method 1
a light guide component for refracting light emitted by the light emitting element to the outside
Implementation Method 2
a reflection portion opposite to the light output surface is formed at the second circuit board
Implementation Method 3
incorporating a diffuser sheet for uniform emission
Data Source
AI summary
A fingerprint assembly including: a first circuit board, a second circuit board connected to a side of the first circuit board, a chip connected to a side of the second circuit board away from the first circuit board, a light guide aperture connected between an outer periphery of the chip and the first circuit board, and an annular-shaped light emitting element connected to the first circuit board. The first and second circuit boards and the light guide aperture jointly enclose to define an annular groove matching with the light emitting element, which is arranged in the annular groove. A light entrance surface is formed at a side of the light guide aperture facing the light emitting element and a light exit surface is formed at a side of the light guide aperture away from the first circuit board. The fingerprint assembly solves a problem of uneven light emission.