Fingerprint identifying device and fingerprint identifying system

Patent metadata

Field	Value
Publication number	US-9811710-B2
Application number	US-201615116172-A
Country	US
Kind code	B2
Filing date	Jan 21, 2016
Priority date	Aug 28, 2015
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A fingerprint identifying device and a fingerprint identifying system are provided. The fingerprint identifying device including: a substrate; a transparent cover plate, located right above the substrate; a detection light source, located on a first side of the transparent cover plate; and a photoelectric sensor, located on a side of a lower surface of the transparent cover plate, wherein, a refractive index of the transparent cover plate is less than a refractive index of a skin of a human fingerprint part, the transparent cover plate has a side surface on the first side, and an angle between the side surface and an upper surface of the transparent cover plate is an acute angle, the detection light source is configured to provide a light beam towards the side surface of the transparent cover plate, so that the light beam is incident to the upper surface of the transparent cover plate through the side surface of the transparent cover plate, and the light beam is totally reflected on the upper surface of the transparent cover plate in a case that the upper surface of the transparent cover plate is in contact with air, the photoelectric sensor is configured to receive a light beam reflected from the upper surface of the transparent cover plate. The fingerprint identifying device is capable of improving the identifying accuracy thereof.

First claim

The invention claimed is:

1. A fingerprint identifying device, comprising:
a substrate;
a transparent cover plate, located right above the substrate;
a detection light source, located on a first side of the transparent cover plate; and
a photoelectric sensor, located on a side of a lower surface of the transparent cover plate, wherein,
a refractive index of the transparent cover plate is less than a refractive index of a skin of a human fingerprint part, the transparent cover plate has a side surface on the first side, and an angle α between the side surface and an upper surface of the transparent cover plate is an acute angle,
the detection light source is configured to provide a light beam towards the side surface of the transparent cover plate, so that the light beam is incident to the upper surface of the transparent cover plate through the side surface of the transparent cover plate, and the light beam is totally reflected on the upper surface of the transparent cover plate in a case that the upper surface of the transparent cover plate is in contact with air,
the photoelectric sensor is configured to receive a light beam reflected from the upper surface of the transparent cover plate.

2. The fingerprint identifying device according to claim 1 , wherein, the light beam provided by the detection light source is a parallel light beam, and an incident angle β of the parallel light beam on the side surface of the transparent cover plate satisfies equations as follows: β=90°−α, or β=0°.

3. The fingerprint identifying device according to claim 2 , wherein, the substrate is a display panel, and the display panel has a display region and a peripheral region; wherein,
the photoelectric sensor is located in the display region, and the angle α is determined by a formula as follows:
h ·tan θ 1 +h /tan α+ d ·tan θ 1 <L 1

where, if β=90°−α, θ 1 =arc sin(sin β·n 0 /n 1 ); and if β=0°, θ 1 =α;
n 1 denotes a refractive index of the transparent cover plate, h denotes a thickness of the transparent cover plate, d denotes a distance from a light receiving surface of the photoelectric sensor to the upper surface of the transparent cover plate, L 1 denotes a width from an edge of the upper surface of the transparent cover plate on the first side to a vertical projection of an interface between the display region and the peripheral region on a side opposite to the first side on the upper surface of the transparent cover plate, n 0 denotes a refractive index of a medium adjoining to the side surface on the first side of the transparent cover plate, and θ 1 denotes an incident angle of the light beam on the upper surface after entering into the transparent cover plate.

4. The fingerprint identifying device according to claim 3 , wherein, the angle α is further determined by a width w 1 of a touch region; wherein, w 1 =h·tan θ 1 +h/tan α.

5. The fingerprint identifying device according to claim 4 , wherein, the display panel has an array substrate and a counter substrate which are arranged opposite to each other in the display region; wherein, the counter substrate is located between the transparent cover plate and the array substrate;
the photoelectric sensor is located on a side of the array substrate facing the counter substrate; or
the photoelectric sensor is located on a side of the counter substrate facing the array substrate; or
the photoelectric sensor is located between the transparent cover plate and the counter substrate.

6. The fingerprint identifying device according to claim 3 , wherein, the display panel has an array substrate and a counter substrate which are arranged opposite to each other in the display region; wherein, the counter substrate is located between the transparent cover plate and the array substrate;
the photoelectric sensor is located on a side of the array substrate facing the counter substrate; or
the photoelectric sensor is located on a side of the counter substrate facing the array substrate; or
the photoelectric sensor is located between the transparent cover plate and the counter substrate.

7. The fingerprint identifying device according to claim 1 , wherein, the transparent cover plate is a glass cover plate.

8. The fingerprint identifying device according to claim 7 , wherein, the substrate is a display panel, and the display panel has a display region and a peripheral region; wherein,
the plurality of photoelectric sensors are located in the peripheral region on a side opposite to the first side, and the angle α is determined by a formula as follows:
0<( d−L+h ·tan θ 1 +h /tan α− L 2)· cot θ 1 ·cot [arc sin(cos θ 1 ·n 1 /n 2 ]<L 2

where, if β=90°−α, θ 1 =arc sin(sin β·n 0 /n 1 ); and if β=0°, θ 1 =α;
n 1 denotes a refractive index of the transparent cover plate, h denotes a thickness of the transparent cover plate, d denotes a distance from a light receiving surface of the photoelectric sensor to the upper surface of the transparent cover plate, L 2 denotes a width of a peripheral region O, L denotes a width from an edge of the upper surface of the transparent cover plate on the first side to a vertical projection of an outer edge of the peripheral region on a side opposite to the first side on the upper surface of the transparent cover plate, n 0 denotes a refractive index of a medium adjoining to the side surface on the first side of the transparent cover plate, θ 1 denotes an incident angle of the light beam on the upper surface after entering into the transparent cover plate, and n 2 denotes a refractive index of a medium through which the light beam reflected from the upper surface of the transparent cover plate passes after entering into the peripheral region.

9. The fingerprint identifying device according to claim 8 , wherein, the angle α is further determined by a width w 1 of a touch region; where, w 1 =d·tan θ 1 −(L−h·tan θ 1 −h/tan α−L 2 ).

10. The fingerprint identifying device according to claim 8 , wherein, the fingerprint identifying device further comprises a light-blocking layer located in the peripheral region and arranged between the display panel and the transparent cover plate.

11. The fingerprint identifying device according to claim 10 , wherein, the light blocking layer is provided with a plurality of via holes, the light beam reflected from the upper surface of the transparent cover plate irradiates on a light receiving surface of the photoelectric sensor through the via holes.

12. The fingerprint identifying device according to claim 7 , wherein, the substrate is a display panel, and the display panel has a display region and a peripheral region; wherein,
the photoelectric sensor is located in the display region, and the angle α is determined by a formula as follows:
h ·tan θ 1 +h /tan α+ d ·tan θ 1 <L 1

where, if β=90°−α, θ 1 =arc sin(sin β·n 0 /n 1 ); and if β=0°, θ 1 =α;
n 1 denotes a refractive index of the transparent cover plate, h denotes a thickness of the transparent cover plate, d denotes a distance from a light receiving surface of the photoelectric sensor to the upper surface of the transparent cover plate, L 1 denotes a width from an edge of the upper surface of the transparent cover plate on the first side to a vertical projection of an interface between the display region and the peripheral region on a side opposite to the first side on the upper surface of the transparent cover plate, n 0 denotes a refractive index of a medium adjoining to the side surface on the first side of the transparent cover plate, and θ 1 denotes an incident angle of the light beam on the upper surface after entering into the transparent cover plate.

Assignees

• Boe Technology Group Co Ltd
• Beijing Boe Optoelectronics Tech Co Ltd

Inventors

• Gao Jian
• Liu Yingming
• Niu Xiaochen
• Chen Xiaochuan
• Wang Haisheng
• Wang Qian
• Yang Ming
• Lu Pengcheng

Classifications

• G06V40/1318 Primary

  using electro-optical elements or layers, e.g. electroluminescent sensing · CPC title

• G06V40/1324 Primary

  by using geometrical optics, e.g. using prisms (G06V40/1312 takes precedence) · CPC title

• G06K9/00053

  Physics · mapped topic

• G06K9/0004 Primary

  Physics · mapped topic

• G06V40/1329

  Protecting the fingerprint sensor against damage caused by the finger · CPC title