Fingerprint detection device and display device

• US 10,242,244 B2
• Filed: 01/23/2017
• Issued: 03/26/2019
• Est. Priority Date: 01/27/2016
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Kurasawa, Hayato, Uehara, Toshinori, Mizuhashi, Hiroshi
• Primary Examiner(s): Woldemariam, Aklilu K
• Application Number:
  US15/412,793
• Publication Number:
  US 20170213065A1
• Time in Patent Office: 792 Days
• Field of Search: 382124, 382125, 382126, 345173, 345174, 345175
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

A fingerprint detection device includes: a substrate having a first surface and a second surface on an opposite side of the first surface, the first surface serving as a detection surface configured to detect unevenness of an object in contact or in proximity; a detection electrode provided on the second surface side of the substrate and configured to detect unevenness of a finger in contact or in proximity on the basis of an electrostatic capacitance change; and a drive circuit provided on the second surface side of the substrate and configured to supply a drive signal to the detection electrode.

Claims

1. A fingerprint detection device, comprising:

a substrate having a first surface and a second surface on an opposite side of the first surface, the first surface serving as a detection surface configured to detect unevenness of an object in contact or in proximity;

a detection electrode provided on the second surface side of the substrate and configured to detect unevenness of a finger in contact or in proximity on the basis of an electrostatic capacitance change;

a drive circuit provided on the second surface side of the substrate and configured to supply a drive signal to the detection electrode;

a switching element provided at a position corresponding to the detection electrode;

a gate line configured to supply a scanning signal to the switching element; and

a first wire having conductivity, the first wire being supplied with a signal synchronized with the drive signal, wherein

in a first direction perpendicular to the second surface, a distance from the detection electrode to the second surface is no more than a distance from the gate line to the second surface, and is shorter than a distance from the switching element to the second surface,

the gate line extends in a second direction along one side of the detection electrode, the first wire extends in the second direction and is disposed between the detection electrode and the gate line in a third direction crossing the second direction, and in the first direction, the distance from the detection electrode to the second surface is no more than a distance from the first wire to the second surface.

2. The fingerprint detection device according to claim 1, wherein the first wire is provided to surround a periphery of the detection electrode.

3. The fingerprint detection device according to claim 1, wherein the first wire is provided in a layer in which the gate line is provided.

4. The fingerprint detection device according to claim 1, further comprising a second wire that is provided along the gate line so as to overlap with the gate line, wherein in the first direction, the distance from the detection electrode to the second surface is no more than a distance from the second wire to the second surface.

5. The fingerprint detection device according to claim 4, wherein the second wire has a width larger than a width of the gate line.

6. The fingerprint detection device according to claim 4, wherein the second wire has a light transmittance smaller than a light transmittance of the substrate.

7. The fingerprint detection device according to claim 1, further comprising a conductive layer that covers the detection electrode and is provided at a position farther away from the second surface than the detection electrode is.

8. The fingerprint detection device according to claim 1, further comprising:

a planarization layer provided on the second surface side to cover the detection electrode; and

a protective layer including an inorganic material on the planarization layer.

9. The fingerprint detection device according to claim 8, wherein the inorganic material comprises a translucent conductive material.

10. The fingerprint detection device according to claim 1, wherein the substrate is fixed to a casing, and the first surface is exposed from an opening provided in the casing.

11. A display device, comprising:

a first substrate having a first surface and a second surface on an opposite side of the first surface, the second surface serving as a detection surface configured to detect unevenness of an object in contact or in proximity;

a second substrate having a display surface, in which a surface on an opposite side of the display surface is opposed to the first surface of the first substrate;

a detection electrode provided on the first surface side of the first substrate and configured to detect unevenness of a finger in contact or in proximity with the second surface;

a switching element provided at a position corresponding to the detection electrode;

a gate line configured to supply a scanning signal to the switching element;

a display function layer provided between the first substrate and the second substrate at a position farther away from the first surface than the detection electrode is, the display function layer being configured to form an image to be displayed on the display surface; and

a first wire having conductivity, the first wire being supplied with a signal synchronized with the drive signal, wherein

in a direction perpendicular to the second surface, a distance from the detection electrode to the second surface is no more than a distance from the gate line to the second surface, and is shorter than a distance from the switching element to the second surface, the gate line extends in a second direction along one side of the detection electrode, the first wire extends in the second direction and is disposed between the detection electrode and the gate line in a third direction crossing the second direction, and in the direction, the distance from the detection electrode to the second surface is no more than a distance from the first wire to the second surface.

12. A fingerprint detection device, comprising:

a substrate having a first surface and a second surface on an opposite side of the first surface;

a first detection electrode provided on the first surface side of the substrate and configured to detect unevenness of a finger in contact or in proximity with the second surface;

a second detection electrode provided on the first surface side of the substrate at a position farther away from the first surface than the first detection electrode is, and configured to detect unevenness of a finger in contact or in proximity on the first surface side;

a first detection switching element provided at a position corresponding to the first detection electrode;

a first detection gate line configured to supply a scanning signal to the first detection switching element; and

a first wire having conductivity, the first wire being supplied with a signal synchronized with the drive signal, wherein

in a first direction perpendicular to the second surface, a distance from the first detection electrode to the second surface is no more than a distance from the first detection gate line to the second surface, and is shorter than a distance from the first detection switching element to the second surface,

the gate line extends in a second direction along one side of the detection electrode, the first wire extends in the second direction and is disposed between the detection electrode and the gate line in a third direction crossing the second direction, and in the first direction, the distance from the detection electrode to the second surface is no more than a distance from the first wire to the second surface.

13. The fingerprint detection device according to claim 12, wherein the first detection electrode is provided to overlap with the second detection electrode.

14. The fingerprint detection device according to claim 12, further comprising a conductive layer provided between the first detection electrode and the second detection electrode in a second direction perpendicular to the first surface so as to cover the first detection electrode.

15. The fingerprint detection device according to claim 12, further comprising:

a second detection switching element provided at a position corresponding to the second detection electrode; and

a second detection gate line configured to supply a scanning signal to the second detection switching element.

16. The fingerprint detection device according to claim 15, further comprising a second wire that overlaps with the second detection gate line.