In-cell Spatial Filter for Accurate Optical Fingerprint Imaging
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Solution Overview
Problem
Current optical fingerprint identification apparatuses face challenges in achieving accurate image capturing due to inadequate filtering capabilities of spatial filters, leading to decreased fingerprint identification accuracy and increased thickness in on-cell display apparatuses.
Innovation Solution
An image capture apparatus with a spatial filter comprising a translucent substrate and light shielding structures, including a light absorbing/reflective layer stack, where the reflective layer and light absorbing layer are strategically positioned to direct light beams accurately to pixel regions, reducing cross-talk and improving image capturing quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional spatial filter is used, then the structure is simple, but the filtering capability is insufficient leading to poor image capturing accuracy
Solution Approach 1:
The spatial filter is segmented into multiple functional layers: a translucent substrate layer, a light shielding layer with first openings, and a reflective layer with second openings. Each layer performs a specific filtering function, allowing light to pass through only through precisely aligned openings while blocking stray light, thereby improving image capturing accuracy through structured segmentation.
Solution Approach 2:
The invention transitions from a conventional single-layer spatial filter to a multi-layer stacked structure in the vertical dimension. By adding depth through multiple layers with precisely aligned openings, the filter achieves superior light control and filtering capability without increasing lateral complexity, resolving the contradiction between accuracy and structural simplicity.
2Device complexity
If the image capture apparatus is adhered on one layer of the display apparatus, then the integration is achieved, but the thickness of the display apparatus increases
Solution Approach 1:
The image capture apparatus is merged with the display apparatus by integrating the spatial filter structure into the existing display layers. The translucent substrate and light shielding/reflective layers are combined with the display panel structure, allowing the image capture function to be embedded within the display thickness rather than adding a separate external module.
Solution Approach 2:
The spatial filter components are nested within the display apparatus structure. The light shielding layer and reflective layer are positioned between the display panel layers, with the image capture element integrated into the same stack, creating a nested configuration that achieves integration without proportionally increasing overall thickness.
3Measurement precision
If the light shielding structure uses only a light absorbing layer, then the structure is simple, but the light beam cannot be accurately directed to pixel regions
Solution Approach 1:
The light shielding structure is segmented into two distinct functional layers: a light absorbing layer that absorbs stray light and a reflective layer that reflects light beams toward the pixel regions. This segmentation allows each layer to perform its specific optical function, achieving accurate light direction through the coordinated action of absorption and reflection.
Solution Approach 2:
The reflective layer acts as an intermediary between the incoming light and the pixel regions. By positioning the reflective layer below the light absorbing layer, the structure uses reflection as an intermediate mechanism to redirect light beams accurately to the corresponding pixel regions, improving directional precision beyond what a single absorbing layer could achieve.
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 enhances image capturing accuracy and reduces the thickness of in-cell display apparatuses by ensuring light beams are accurately transmitted to corresponding pixel regions, minimizing cross-talk and improving overall image quality.
Implementation Method 1
the light shielding structure comprises a light absorbing/reflective layer and a reflective layer in the first direction stacked to each other. The light absorbing/reflective layer has a plurality of first openings in a second direction perpendicular to the first direction
Implementation Method 2
the reflective layer has a plurality of second openings in the second direction, each of the first openings is corresponding to one of the pixel regions, and one of the second openings and one of the micro lenses in the first direction
Data Source
AI summary
An image capture apparatus is illustrated, which has an image capture element and an optical component layer. The image capture element has a plurality of pixel regions. The optical component layer comprises a microstructure layer and a spatial filter formed on the image capture element in a first direction. The microstructure layer has micro lenses formed on a surface of the microstructure layer. The spatial filter has at least one translucent substrate and at least one light shielding structure, and the light shielding structure has a light absorbing/reflective layer and a reflective layer in the first direction stacked to each other. The light absorbing/reflective layer is another one light reflective layer or a light absorbing layer.