Optics-based fingerprint sensor, electric device including optics-based fingerprint sensor, and operation method of electric device

Patent metadata

Field	Value
Publication number	US-2019019000-A1
Application number	US-201815978586-A
Country	US
Kind code	A1
Filing date	May 14, 2018
Priority date	Jul 13, 2017
Publication date	Jan 17, 2019
Grant date	—

Abstract

An optics-based fingerprint sensor may include a first photodiode, a first metal shield structure that is formed on the first photodiode and includes a first opening, a first color filter structure that is formed on the first metal shield structure and including a second opening exposing the first opening, a second photodiode that is spaced apart from the first photodiode by a predetermined distance, a first nano-optical filter structure that is formed on the second photodiode, and a first band limit filter structure that is formed on the nano-optical filter structure.

First claim

1 . An optics-based fingerprint sensor comprising:
a first photodiode; a first metal shield structure formed on the first photodiode and including a first opening; a first color filter structure formed on the first metal shield structure and including a second opening exposing the first opening; a second photodiode spaced apart from the first photodiode by a predetermined distance; a first nano-optical filter structure formed on the second photodiode; and a first band limit filter structure formed on the first nano-optical filter structure.

2 . The optics-based fingerprint sensor of claim 1 , wherein the first metal shield structure and the first nano-optical filter structure are formed in a first layer disposed on the first photodiode and the second photodiode.

3 . The optics-based fingerprint sensor of claim 2 , wherein the first color filter structure and the first band limit filter structure are formed in a second layer disposed on the first layer.

4 . The optics-based fingerprint sensor of claim 1 , wherein the first band limit filter structure is configured to pass first wide band light, which belongs to a first band, of light reflected from a user fingerprint.

5 . The optics-based fingerprint sensor of claim 4 , wherein the first nano-optical filter structure includes a plurality of holes each having a first diameter and is configured to pass only first narrow band light, which is determined according to the first diameter, of the first wide band light.

6 . The optics-based fingerprint sensor of claim 4 , wherein the first nano-optical filter structure includes a plurality of discs each having a first diameter and is configured to block only first narrow band light, which is determined according to the first diameter, of the first wide band light.

7 . The optics-based fingerprint sensor of claim 1 , further comprising:
a third photodiode adjacent to the second photodiode; a second nano-optical filter structure formed on the second photodiode; and a second band limit filter structure formed on the second nano-optical filter structure, wherein the first nano-optical filter structure and the second nano-optical filter structure have different optical characteristics from each other.

8 . The optics-based fingerprint sensor of claim 7 , further comprising:
a fourth photodiode adjacent to the first photodiode; a second metal shield structure formed on the fourth photodiode and including a third opening; and a second color filter structure formed on the second metal shield structure and including a fourth opening exposing the third opening.

9 . The optics-based fingerprint sensor of claim 1 , wherein the first color filter structure includes:
a first color filter configured to pass first light, which corresponds to a first color, of light reflected from a user fingerprint; and a second color filter formed on the first color filter and configured to transmit second light, which corresponds to a second color, of the reflected light.

10 . The optics-based fingerprint sensor of claim 1 , wherein the first color filter structure includes:
a black color filter configured to block light reflected from the first metal shield structure.

11 . The optics-based fingerprint sensor of claim 1 , further comprising:
an optical lens formed on the first color filter structure and configured to focus light reflected from a user fingerprint.

12 . The optics-based fingerprint sensor of claim 1 , further comprising:
an infrared cut filter structure formed on the first color filter structure.

13 . An optics-based fingerprint sensor comprising:
a first fingerprint pixel configured to output a first signal, based on a first intensity of light reflected from a user fingerprint; a first spectrum pixel configured to output a second signal, based on a second intensity of first narrow band light, which has a first wavelength, of the reflected light; and a sensor driver configured to:
control the first fingerprint pixel and the first spectrum pixel, to generate fingerprint image information about the user fingerprint, based on the first signal, and
generate fingerprint spectrum information about the user fingerprint, based on the second signal.

14 . The optics-based fingerprint sensor of claim 13 , wherein the first spectrum pixel includes:
a first band limit filter structure configured to pass first wide band light, which belongs to a first band, of the reflected light; a first nano-optical filter structure formed under the first band limit filter structure and configured to pass the first narrow band light of the first wide band light; and a second photodiode formed under the first nano-optical filter structure and configured to output the second signal, based on the first narrow band light.

15 . The optics-based fingerprint sensor of claim 14 , wherein the first fingerprint pixel includes:
an optical lens configured to focus the reflected light; a first color filter structure formed under the optical lens and including a first opening configured to pass the focused reflected light; a first metal shield structure formed under the first color filter structure and including a second opening configured to pass the reflected light passing through the first opening; and a first photodiode configured to output the first signal, based on the reflected light passing through the second opening.

16 . The optics-based fingerprint sensor of claim 15 , wherein the first metal shield structure and the first nano-optical filter structure are formed in a first layer on the first photodiode and the second photodiode, and
wherein the first color filter structure and the first band limit filter structure are formed in a second layer on the first layer.

17 . The optics-based fingerprint sensor of claim 15 , wherein the first color filter structure comprises:
a first color filter configured to pass first light, which corresponds to a first color, of the reflected light; and a second color filter configured to pass second light, which corresponds to a second color, of the reflected light.

18 . The optics-based fingerprint sensor of claim 15 , wherein the first fingerprint pixel further comprises:
an infrared cut filter formed between the optical lens and the first color filter structure.

19 . The optics-based fingerprint sensor of claim 13 , further comprising:
a second spectrum pixel configured to output a third signal, based on an intensity of second narrow band light, which has a second wavelength, of the reflected light, wherein the sensor driver generates the fingerprint spectrum information, based on the second signal and the third signal.

20 . The optics-based fingerprint sensor of claim 13 , further comprising:
a dummy area interposed between the first fingerprint pixel and the first spectrum pixel.

21 - 30 . (canceled)

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Minchul
• Lee Kwanhee
• Chung Daeyoung
• Cho Sanghyun
• Cho Wonho
• Ko Hayoung
• Lee Jongsung
• Hwang Heechang

Classifications

• H10W90/00 Primary

  Package configurations · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title

• G02B5/204

  in which spectral selection is performed by means of a conductive grid or array, e.g. frequency selective surfaces (for use with wavelengths longer than the infrared light H01Q15/0006) · CPC title

• G02B27/0955

  Lenses (lenses per se G02B3/00) · CPC title

• G02B5/20

  Filters (polarising elements G02B5/30) · CPC title