Touch screen, positioning method thereof and touch display device

Patent metadata

Field	Value
Publication number	US-2016306498-A1
Application number	US-201414779164-A
Country	US
Kind code	A1
Filing date	Nov 24, 2014
Priority date	Aug 28, 2014
Publication date	Oct 20, 2016
Grant date	—

Abstract

A touch screen, a positioning method thereof and a touch display device. The touch screen includes a touch area; a plurality of emitters disposed on a first side of the touch area; a plurality of receivers disposed on a second side of the touch area opposite to the first side of the touch area; and direction changing units disposed in the light ray-emitting directions of at least part of the emitters and configured to change emitting directions of light rays emitted by the emitters so that the light rays with different emitting directions are emitted at different time periods and the light rays with the different emitting directions are received by different receivers. The touch screen has an increased resolution.

First claim

1 . A touch screen, comprising
a touch area; a plurality of emitters, which are disposed on a first side of the touch area; and a plurality of receivers, which are disposed on a second side of the touch area opposite to the first side of the touch area; direction changing units being disposed in the light ray-emitting directions of at least part of the emitters, wherein the emitters are configured to emit light rays, wherein the direction changing units are configured to change emitting directions of light rays emitted by the emitters so that the light rays with different emitting directions are emitted at different time periods and the light rays with the different emitting directions are emitted to different receivers, and wherein the receivers are configured to receive the light rays emitted by the emitters.

2 . The touch screen of claim 1 , wherein the emitters are further disposed on a third side of the touch area, and the receivers are further disposed on a fourth side of the touch area opposite to the third side.

3 . The touch screen of claim 1 , wherein the direction changing units each comprise a first substrate and a second substrate which are oppositely disposed,
wherein a first electrode is disposed on the first substrate, a second electrode is disposed on the second substrate, a light transmitting layer and a liquid crystal layer are disposed between the first substrate and the second substrate, and a contact surface of the light transmitting layer and the liquid crystal layer is not parallel to the second substrate.

4 . The touch screen of claim 3 , wherein the light rays emitted by the emitters comprise first polarized light rays which are perpendicular to the plane of the touch area and second polarized light rays which are parallel to the plane of the touch area.

5 . The touch screen of claim 4 , wherein, when a first voltage is applied between the first electrode and the second electrode, the first polarized light rays and the second polarized light rays pass through the liquid crystal layer without any refraction occurring on the contact surface of the liquid crystal layer and the light transmitting layer, and directly transmit through the light transmitting layer; or
when a second voltage is applied between the first electrode and the second electrode, the first polarized light rays passes through the liquid crystal layer with refraction occurring on the contact surface of the liquid crystal layer and the light transmitting layer, and the refracted first polarized light rays pass through the light transmitting layer, the second polarized light rays pass through the liquid crystal layer without any refraction occurring on the contact surface of the liquid crystal layer and the light transmitting layer, and directly transmit through the light transmitting layer.

6 . The touch screen of claim 5 , wherein, when the first voltage is applied between the first electrode and the second electrode, the refractive index of the light transmitting layer is the same as the refractive index of the liquid crystal layer.

7 . The touch screen of claim 5 , wherein, when the second voltage is applied between the first electrode and the second electrode, the liquid crystal molecules in the liquid crystal layer are deflected at a plane which is perpendicular to the touch area in order to change the refractive index of the liquid crystal layer.

8 . The touch screen of claim 3 , wherein a material of the light transmitting layer comprises polymethylacrylate or polycarbonate.

9 . A touch display device comprising the touch screen according to claim 1 .

10 . A positioning method for a touch screen including a touch area, a plurality of emitters disposed on a first side of the touch area, a plurality of receivers disposed on a second side of the touch area opposite to the first side of the touch area, and direction changing units disposed in the light ray-emitting directions of at least part of the emitters, the method comprising:
determining whether a light ray is blocked and, if the light ray is blocked, determining a path of the blocked light ray; and calculating coordinates of at least one of intersections between blocked light rays from the determined paths of the blocked light rays and determining a position of a touch point from the coordinates of the at least one of intersections.

11 . The positioning method for the touch screen of claim 10 , wherein a calculating formula for calculating the coordinates of the intersections of the blocked light rays from the determined paths of the blocked light rays is as follow.

x
=

ad
-
bc

a
-
b
-
c
+
d

,



y
=

an
-
bn
-

c



m

+

d



m

a
-
b
-
c
+
d

where the coordinates of the intersection are (x, y), the coordinates of the emitter corresponding to one of paths of the blocked light rays is (a, m), the coordinates of the corresponding receiver is (c, n), the coordinates of the emitter corresponding to the other of paths of the blocked light rays is (b, m), the coordinates of the corresponding other receiver is (d, n), with a−b−c+d≠0.

12 . The positioning method for the touch screen of claim 10 , wherein a calculating formula for calculating the coordinates of the intersection of the blocked light rays from the determined paths of the blocked light rays is as follow,

x
=

an
-
bn
-

c



m

+

d



m

a
-
b
-
c
+
d

Assignees

• Boe Technology Group Co Ltd
• Hefei Xinsheng Optoelectronics Technology Co Ltd
• Hefei Xinsheng Optoelectronics Technology Co Ltd

Inventors

• Wang Huan
• Shin Mookeun
• Tu Zhizhong
• Yoon Yong Jun

Classifications

• G06F3/0421 Primary

  by interrupting or reflecting a light beam, e.g. optical touch-screen · CPC title

• G09G3/3696

  Generation of voltages supplied to electrode drivers · CPC title

• G02F1/00

  Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics · CPC title

• G02F1/29

  for the control of the position or the direction of light beams, i.e. deflection · CPC title