Semiconductor Fingerprint Sensor Row-Selective Readout
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Solution Overview
Problem
Current fingerprint authentication methods using light-emitting and light-receiving elements are inefficient, requiring extended time to obtain high-resolution images, which can be stressful for users and are not highly accurate or reliable.
Innovation Solution
A semiconductor device with a light-emitting apparatus and an imaging apparatus featuring a pixel portion arranged in a matrix and a row driver circuit with a shift register, allowing for selective detection and imaging of a finger's fingerprint by skipping unnecessary rows and columns, thereby reducing the time and increasing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light is emitted and reflected by the finger to obtain a high-resolution fingerprint image, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The pixel array is divided into multiple regions, with only the region corresponding to the finger placement area being actively used for fingerprint capture. This segmentation allows the system to maintain high measurement precision for the fingerprint region while reducing the total number of pixels that need to be read out, thereby decreasing authentication time.
Solution Approach 2:
Different regions of the pixel array are assigned different functions: the central region captures fingerprint information with high precision, while surrounding regions are skipped or used for other purposes. This local quality approach ensures that measurement precision is concentrated where needed (on the fingerprint) while reducing overall processing time by not uniformly processing all pixels.
2Measurement precision
If all pixels in the pixel array are used for imaging, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and processes only the relevant portion of the pixel array data corresponding to the fingerprint region, rather than processing all pixel data. This extraction principle reduces device complexity by eliminating unnecessary data processing steps while maintaining measurement precision for the essential fingerprint information.
Solution Approach 2:
Instead of using all pixels in the array (excessive action), the system uses only the necessary subset of pixels that correspond to the finger placement area (partial action). This approach maintains adequate measurement precision for fingerprint authentication while significantly reducing the complexity of data processing and readout operations.
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 semiconductor device enables fast, accurate, and reliable fingerprint authentication by selectively reading out image data from specific rows and columns, reducing the overall authentication time and improving user experience.
Implementation Method 1
a function of detecting a detection target that is located over the pixels in the p-th to q-th rows (p and q are each an integer greater than or equal to 1 and less than or equal to m, and p is smaller than q) of the pixel portion when light that is emitted by the light-emitting apparatus and detected by the detection target is detected
Data Source
AI summary
A semiconductor device capable of performing authentication in a short time and a driving method thereof are provided. A semiconductor device including a light-emitting apparatus and an imaging apparatus and a driving method thereof. The imaging apparatus includes pixels arranged in a matrix and a row driver including a shift register circuit. The driving method includes a first mode and a second mode. The first mode includes a step of detecting a position of a finger of a user. The second mode includes a step of reading out an image of a fingerprint of the user from pixels in the first row to a row of the position where the fingerprint of the user is detected in the first mode, row by row. The operation of the shift register circuit is stopped after the first mode and the second mode are completed.