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Touch fingerprint sensor based on sensor cell isolation technique with pseudo direct signaling Cover

Touch fingerprint sensor based on sensor cell isolation technique with pseudo direct signaling

By: Hyeopgoo Yeo  
Open Access
|May 2018

Figures & Tables

Figure 1

Fingerprint sensor cell (A) circuit for isolation scheme of sensor cell (B) implemented layout of the sensor cell.
Fingerprint sensor cell (A) circuit for isolation scheme of sensor cell (B) implemented layout of the sensor cell.

Figure 2

Top view layout of the 25 fingerprint sensor cell array with fingerprint sensor with isolation sensor cell scheme, an evaluation sensor cell, isolation sensor cells, and transmission sensor cells.
Top view layout of the 25 fingerprint sensor cell array with fingerprint sensor with isolation sensor cell scheme, an evaluation sensor cell, isolation sensor cells, and transmission sensor cells.

Figure 3

The implemented fingerprint sensor with pipelin scan driver hitecture.
The implemented fingerprint sensor with pipelin scan driver hitecture.

Figure 4

The timing diagram and output voltage characteristics of the pipelined scan driver for the fingerprint sensor.
The timing diagram and output voltage characteristics of the pipelined scan driver for the fingerprint sensor.

Figure 5

The implemented full chip layout of the 96 × 96 fingerprint sensor with standard CMOS 0.25 μm technology.
The implemented full chip layout of the 96 × 96 fingerprint sensor with standard CMOS 0.25 μm technology.

Figure 6

Fabricated fingerprint sensor (A) die photo, (B) LGA package front and back.
Fabricated fingerprint sensor (A) die photo, (B) LGA package front and back.

Figure 7

Fingerprint sensor test evaluation environment.
Fingerprint sensor test evaluation environment.

Figure 8

PC interface program.
PC interface program.

Figure 9

Captured fingerprint image (A) original (B) histogram equalization.
Captured fingerprint image (A) original (B) histogram equalization.

Figure 10

Wiener filtered fingerprint image (A) local size of 3 × 3, (B) local size of 5 × 5.
Wiener filtered fingerprint image (A) local size of 3 × 3, (B) local size of 5 × 5.

Figure 11

Weight of 2D Gaussian filter (A) 3 × 3, (B) 5 × 5.
Weight of 2D Gaussian filter (A) 3 × 3, (B) 5 × 5.

Figure 12

2D Gaussian filtered fingerprint images (A) local size of 3 × 3, (B) local size of 5 × 5.
2D Gaussian filtered fingerprint images (A) local size of 3 × 3, (B) local size of 5 × 5.

Figure 13

Weight estimation of 2D FIR filter for 50 µm-thick molded fingerprint sensor.
Weight estimation of 2D FIR filter for 50 µm-thick molded fingerprint sensor.

Figure 14

Weight of 2D FIR filter (A) 3 × 3, (B) 5 × 5.
Weight of 2D FIR filter (A) 3 × 3, (B) 5 × 5.

Figure 15

2D FIR filtered fingerprint images (A) 3 × 3, (B) 5 × 5.
2D FIR filtered fingerprint images (A) 3 × 3, (B) 5 × 5.

Figure 16

The matching performance of the fingerprint sensor (FAR vs. FRR).
The matching performance of the fingerprint sensor (FAR vs. FRR).

Performance summary and comparisons_

ParameterThis workRef. Hassan and Kim (2018)Ref. Shimamura et al. (2010)Ref. Jung et al. (2005)
Technology0.25 µm0.13 µm0.5 µm0.35 µm
Type of sensorCapacitiveCapacitiveCapacitiveCapacitive
Supply voltage1.8~2.5 V1.5 V3.3 V3 V
Molding thickness80 µm
Operating frequency10 MHz (readout 30 MHz)1 MHz40 MHz
Power dissipation<3 mA7.5 mA (25 mW)7.5 mA (25 mW)
Image capture timea <20 ms0.2 ms20 ms
Array size96 × 9620 × 16224 × 256160 × 192
Image resolution508 ppi282 ppi508 ppi423 ppi
FRR@FAR = 10−4 2.2%
Language: English
Page range: 1 - 9
Submitted on: Oct 18, 2018
Accepted on: Mar 2, 2019
Published on: May 2, 2018
Published by: Professor Subhas Chandra Mukhopadhyay
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2018 Hyeopgoo Yeo, published by Professor Subhas Chandra Mukhopadhyay
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.