FINGERPRINT DETECTION DEVICE AND DISPLAY DEVICE

• US 20170213065A1
• Filed: 01/23/2017
• Published: 07/27/2017
• Est. Priority Date: 01/27/2016
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Uehara, Toshinori, Kurasawa, Hayato, Mizuhashi, Hiroshi
• Granted Patent: US 10,242,244 B2
• Time in Patent Office: Days
• 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; and

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

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

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

a gate line configured to supply a scanning signal to the switching element, wherein

the detection electrode is provided in a layer in which the gate line is provided, or the detection electrode is provided closer to the second surface than the gate line is.

3. The fingerprint detection device according to claim 1, further comprising first wire having conductivity between the detection electrode and the gate line, wherein

the first wire is supplied with a signal synchronized with the drive signal.

4. The fingerprint detection device according to claim 3, wherein the first wire is provided to surround a periphery of the detection electrode.

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

6. The fingerprint detection device according to claim 3, further comprising second wire that is provided along the gate line so as to overlap with the gate line.

7. The fingerprint detection device according to claim 6, wherein the second wire has a width larger than a width of the gate line.

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

9. 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.

10. 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.

11. The fingerprint detection device according to claim 10, wherein the inorganic material comprises a translucent conductive material.

12. 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.

13. 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; and

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.

14. 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; and

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.

15. The fingerprint detection device according to claim 14, wherein the first detection electrode is provided to overlap with the second detection electrode.

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

17. The fingerprint detection device according to claim 14, further comprising:

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

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

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

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

18. The fingerprint detection device according to claim 17, further comprising first wire that overlaps with the first detection gate line.

19. The fingerprint detection device according to claim 17, further comprising second wire that overlaps with the second detection gate line.