Image Capture Apparatus Light Guiding Member for Fingerprint Accuracy
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Solution Overview
Problem
Conventional fingerprint identification devices integrated with thin film transistor liquid crystal displays suffer from image blurriness and reduced accuracy due to light beam diffusion and contamination on the outer surface of the light transmitting element.
Innovation Solution
An image capture apparatus is designed with a light guiding member divided into a light guiding portion and a light penetrating portion, and a first and second reflecting layer on the display panel, which directs the sensing light beam to prevent surface contaminants from affecting the image quality by ensuring total reflection and transmission within the light guiding member.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a light transmitting plate is used for fingerprint recognition, then the device can be integrated with display panels, but contaminants on the outer surface break total reflection and reduce image quality
Solution Approach 1:
A light guiding member is introduced as an intermediary component between the light source and the light transmitting plate. This member guides the light beam through its internal structure to reach the sensing area without the light path being exposed to contaminants on the outer surface, thus maintaining image quality while enabling display integration
Solution Approach 2:
The light beam path is redirected from a direct horizontal path (exposed to surface contaminants) to a vertical path through the light guiding member. By changing the dimensionality of light propagation, the system achieves total reflection within the light guiding member while avoiding contamination on the outer surface
2Device complexity
If the light beam is projected directly onto the light transmitting plate, then the structure is simple, but surface contaminants break total reflection and cause beam loss
Solution Approach 1:
The light guiding member serves as a mediator that preserves the light beam by guiding it through a protected path. This additional component prevents direct exposure of the light path to surface contaminants, reducing beam loss from broken total reflection
Solution Approach 2:
The system replaces direct optical contact with a guided optical path. Instead of relying on direct total reflection at the exposed surface, the light beam is transmitted through the light guiding member which maintains controlled optical conditions, substituting a protected mechanical-guided path for direct optical exposure
3Illumination intensity
If a diffusion sheet is used in the display panel, then light distribution is achieved, but the fingerprint image becomes blurred reducing identification accuracy
Solution Approach 1:
The light guiding member is divided into distinct functional portions: a light guiding portion for maintaining beam direction and a light penetrating portion for allowing light transmission to the sensing area. This segmentation allows different regions to perform different functions - maintaining light directionality for image clarity while still achieving adequate light distribution
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
This solution enhances image quality by maintaining the integrity of the sensing light beam, reducing the impact of surface contaminants and improving the accuracy of fingerprint identification.
Implementation Method 1
a portion of the sensing light beam is totally reflected by the surface to form a signal light beam
Implementation Method 2
The light emitting element is disposed on one side of the light guiding member and is configured to generate a sensing light beam
Implementation Method 3
The image capture apparatus is disposed on the other side of the light guiding member to receive the signal light beam
Data Source
AI summary
An image capturing apparatus includes a light transmitting cover, a display panel, a Light guiding member, a light emitting element, and an image capturing element. The light transmitting cover has a surface in contact with the environmental medium. The light emitting element is disposed on one side of the Light guiding member. The sensing light beam is transmitted to the light penetrating portion in the first light guiding portion to be projected to the display area of the light transmitting cover, and a portion of the sensing light beam is totally reflected by the surface to form a signal beam that enters the second light guiding portion from the light penetrating portion. The image capturing element is disposed on the other side of the Light guiding member to receive the signal light beam that is transmitted in the second light guiding portion.