Touch sensitive device and display device including the same

Patent metadata

Field	Value
Publication number	US-11435828-B2
Application number	US-201816163262-A
Country	US
Kind code	B2
Filing date	Oct 17, 2018
Priority date	Oct 18, 2017
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

Provided is a touch sensitive device including an electroactive layer formed of an electroactive matrix, wherein the electroactive matrix has a structure in which a piezoelectric ceramic and an electroactive polymer (EAP) are bonded and an electrode disposed on at least one surface of the electroactive layer. According to an exemplary embodiment of the present disclosure, the touch sensitive device uses an electroactive matrix has an excellent transparency, can be made thin, and has a high piezoelectric property so that the light transmittance and the vibration intensity of the touch sensitive device can be improved.

First claim

What is claimed is:

1. A touch sensitive device, comprising:
an electroactive layer formed of an electroactive matrix,
wherein the electroactive matrix includes a core particle formed of a piezoelectric ceramic having a hydroxyl group on a surface thereof and a shell enclosing the core particle and formed of an electroactive polymer (EAP) which bonds to the core particle by a hydrogen bond; and
an electrode disposed on at least one surface of the electroactive layer,
wherein the piezoelectric ceramic is a perovskite type nano particle represented by ABO 3 ,
wherein an oxygen atom constituting the piezoelectric ceramic is substituted with the hydroxyl group,
wherein the electroactive polymer comprises at least one among a polyphosphazene and a linear boron nitride polymer,
wherein the polyphosphazene comprises a repeating unit represented by the following Chemical Formula 1:

wherein R 1 and R 2 are the same or different and are each independently a substituted or unsubstituted C 6 to C 50 aryloxy group, and at least one of R 1 and R 2 is a C 6 to C 50 aryloxy group with at least one substituted halogen atom, and n is an arbitrary integer, and
wherein the linear boron nitride polymer comprises a repeating unit represented by the following Chemical Formula 4:

wherein R 3 is a C 1 to C 20 alkyl group, a C 1 to C 20 alkenyl group, a C 1 to C 20 alkynyl group, a C 5 to C 20 aryl group, a C 3 to C 20 cycloalkyl group, a C 1 to C 20 haloalkyl group, halide group or hydrogen, and R 4 is a C 1 to C 20 haloalkyl group or halide group, and m is an arbitrary integer.

2. The touch sensitive device according to claim 1 , wherein the piezoelectric ceramic is at least one of (K, Na) NbO 3 (KNN), BiNaTiO 3 (BNT), Bi(Na, K) TiO 3 (BNKT), and BiKTiO 3 (BKT).

3. The touch sensitive device according to claim 1 , wherein the electroactive polymer includes a halide group.

4. The touch sensitive device according to claim 3 , wherein the electroactive polymer is a ferroelectric polymer.

5. The touch sensitive device according to claim 3 , wherein the electroactive polymer is polyvinylidene fluoride (PVDF).

6. The touch sensitive device according to claim 1 , wherein R 1 is naphtoxy, phenoxy, or phenylphenoxy and R 2 is fluorophenoxy.

7. The touch sensitive device according to claim 1 , wherein the piezoelectric ceramic is (K, Na) NbO 3 (KNN).

8. The touch sensitive device according to claim 1 , wherein the hydroxyl group occupies a face-centered position of the perovskite type nano particle.

9. The touch sensitive device according to claim 1 , wherein a weight ratio between the piezoelectric ceramic and the electroactive polymer (EAP) is approximately 1:9 to 5:5.

10. A display device, comprising:
a display panel; and
a touch sensitive device above or below the display panel,
wherein the touch sensitive device includes an electroactive layer formed of an electroactive matrix,
wherein the electroactive matrix includes a core particle formed of a piezoelectric ceramic having a hydroxyl group on a surface thereof and a shell enclosing the core particle and formed of an electroactive polymer (EAP) which bonds to the core particle by a hydrogen bond,
wherein the piezoelectric ceramic is a perovskite type nano particle represented by ABO 3 , the perovskite type nano particle having a cubic unit structure,
wherein oxygen atoms constituting the piezoelectric ceramic are respectively substituted with the hydroxyl group,
wherein the hydroxyl group occupies face-centered positions of the perovskite type nano particle having the cubic unit structure,
wherein the electroactive polymer comprises at least one among a polyphosphazene and a linear boron nitride polymer,
wherein the polyphosphazene comprises a repeating unit represented by the following Chemical Formula 1:
[Chemical Formula 1]

wherein R 1 and R 2 are the same or different and are each independently a substituted or unsubstituted C 6 to C 50 aryloxy group, and at least one of R 1 and R 2 is a C 6 to C 50 aryloxy group with at least one substituted halogen atom, and n is an arbitrary integer, and
wherein the linear boron nitride polymer comprises a repeating unit represented by the following Chemical Formula 4:
[Chemical Formula 4]

wherein R 3 is a C 1 to C 20 alkyl group, a C 1 to C 20 alkenyl group, a C 1 to C 20 alkynyl group, a C 5 to C 20 aryl group, a C 3 to C 20 cycloalkyl group, a C 1 to C 20 haloalkyl group, halide group or hydrogen, and R 4 is a C 1 to C 20 haloalkyl group or halide group, and m is an arbitrary integer.

11. The display device according to claim 10 , further comprising:
an add-on type touch panel which is separately disposed on the display panel,
wherein the touch sensitive device is disposed between the display panel and the add-on touch panel.

12. The display device according to claim 10 , wherein the display panel is a liquid crystal display panel which includes a touch sensor configured to be integrated in the display panel,
a backlight unit is disposed below the liquid crystal display panel, and
the touch sensitive device is disposed between the liquid crystal display panel and the backlight unit.

13. The display device according to claim 10 , wherein the piezoelectric ceramic is at least one of (K, Na) NbO 3 (KNN), BiNaTiO 3 (BNT), Bi(Na, K) TiO 3 (BNKT), and BiKTiO 3 (BKT).

14. The display device according to claim 10 , wherein R 1 is naphtoxy, phenoxy, or phenylphenoxy and R 2 is fluorophenoxy.

15. The display device according to claim 10 , wherein a weight ratio between the piezoelectric ceramic and the electroactive polymer (EAP) is approximately 1:9 to 5:5.

Assignees

• Lg Display Co Ltd

Inventors

• Kim Chiwan
• Kim Taeheon
• Shin Sungeui
• Lee Yongwoo
• Ryu Kyungyeol
• Kho Yuseon

Classifications

• G06F3/016 Primary

  Input arrangements with force or tactile feedback as computer generated output to the user · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title

• C08G79/025

  Polyphosphazenes · CPC title

• G06F3/041

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• G08B6/00

  Tactile signalling systems, e.g. tactile personal calling systems · CPC title