Optical Fingerprint Sensor Filter Base Removal
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Solution Overview
Problem
Conventional optical fingerprint identification apparatuses face challenges in improving imaging effects due to longer optical paths between light path directing structures and the finger, which degrades the imaging quality and increases device thickness.
Innovation Solution
The solution involves omitting the base material of the filter in the optical fingerprint apparatus, allowing the plating film to be directly applied on the optical fingerprint sensor, thereby reducing the optical path and thickness, and integrating the light path directing structure with the sensor to minimize the distance between the light path directing structure and the display screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional optical fingerprint identification apparatus uses a light path directing structure with a filter having base material, then the filter can effectively filter interference light, but the optical path length increases and imaging effect deteriorates
Solution Approach 1:
The patent extracts and removes the base material from the filter structure, retaining only the essential plating film layer that performs the light filtering function. This extraction eliminates the unnecessary optical path length contributed by the base material while preserving the interference light filtering capability through the plating film alone.
Solution Approach 2:
The patent employs a thin film plating structure without a rigid base material. The plating film serves as both the filtering element and the structural component, replacing the traditional thick base material with a much thinner flexible film structure that minimizes optical path length while maintaining filtering effectiveness.
2Stability of the object's composition
If a conventional optical fingerprint identification apparatus uses a filter with base material, then the filter structure is complete and stable, but the device thickness increases
Solution Approach 1:
The patent removes the base material from the filter structure, extracting only the essential plating film layer. This extraction reduces the overall thickness of the filter component while maintaining structural stability through the plating film's inherent properties and its direct integration with the optical fingerprint sensor.
Solution Approach 2:
The patent merges the filter structure with the optical fingerprint sensor by directly applying the plating film onto the sensor surface. This integration eliminates the need for a separate base material structure, reducing overall device thickness while maintaining filter stability through the unified structure.
3Device complexity
If the optical path between the light path directing structure and the finger is long, then the device can accommodate more components, but the imaging effect deteriorates
Solution Approach 1:
By removing the base material from the filter structure, the patent shortens the optical path length between the light path directing structure and the optical fingerprint sensor. This extraction eliminates the unnecessary optical path contribution from the base material, improving imaging effect while still accommodating essential components through the streamlined 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
This approach enhances the imaging effect of the light path directing structure, reduces the overall thickness of the fingerprint identification apparatus, and conserves space, leading to improved user experience and device design.
Implementation Method 1
an optical fingerprint sensor receives an optical signal reflected by a finger
Implementation Method 2
the optical fingerprint sensor receives an optical signal reflected by a finger on the display screen, where the optical signal may be used to generate fingerprint information of the finger
Data Source
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AI summary
Embodiments of the present application disclose a fingerprint identification apparatus and an electronic device, which can improve an imaging effect of a light path directing structure. The fingerprint identification apparatus is applicable to an electronic device having a display screen and comprises: an optical fingerprint sensor disposed under the display screen to implement under-screen optical fingerprint detection, wherein the optical fingerprint sensor comprises a photosensitive region, the photosensitive region comprises a plurality of sensing units, and the sensing units are configured to detect an optical signal returned via reflection on a finger surface; a light path directing structure disposed between the display screen and the optical fingerprint sensor to transmit the optical signal returned via the reflection on the finger surface to the photosensitive region of the optical fingerprint sensor; and a filter film formed above the photosensitive region of the optical fingerprint sensor and configured to filter the optical signal to filter out interference light.