Touch panel display device

• US 8,581,882 B2
• Filed: 09/26/2008
• Issued: 11/12/2013
• Est. Priority Date: 12/03/2007
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Sohn, Min Ho, Choi, Jong Seong, Jang, Hyung Uk, Lee, Sang Rae, Bae, Sang Hyuck, Yu, Byung Chun
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): LEE, DAVID J
• Application Number:
  US12/232,951
• Publication Number:
  US 20090141002A1
• Time in Patent Office: 1,873 Days
• Field of Search: 345/175
• US Class Current: 345/175
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 2203/11 involving infrared radiation
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A touch panel display device includes a liquid crystal panel to display an image by regulating transmittance of light supplied from a back light unit, and a touch sensing part provided on upper edges of the liquid crystal panel in order to detect a position touched by a user or an object. The touch sensing part includes infrared lamps to generate and emit infrared light, infrared light reflecting tubes mounted with the infrared lamps, and image sensors to sense the infrared light output from the light output regions of the infrared light reflecting tubes. Each of the infrared light reflecting tubes has light output regions and non-output regions evenly formed at a surface facing an upper surface of the liquid crystal panel so that the infrared light emitted from the infrared lamps is evenly irradiated on the upper surface of the liquid crystal panel.

Claims

1. A touch panel display device comprising:

a liquid crystal panel to display an image by transmittance of light supplied from a back light unit; and

a touch sensing part provided on upper edges of the liquid crystal panel in order to detect a position touched by a user or an object,

wherein the touch sensing part includes;

a plurality of infrared lamps to generate and emit infrared light;

infrared light reflecting tubes mounted with the infrared lamps, each of the infrared light reflecting tubes having a plurality of light output regions and a plurality of non-output regions formed at a surface facing an upper surface of the liquid crystal panel so that the infrared light emitted from the infrared lamps is irradiated on the upper surface of the liquid crystal panel; and

a plurality of image sensors to sense the infrared light emitted from the infrared lamps;

a plurality of additional infrared lamps provided at certain positions of the infrared light reflecting tubes, wherein the certain positions correspond to where the intensity of the infrared light emitted from the infrared lamps drops below a threshold by which the image sensors sense a user'"'"'s or object'"'"'s touch;

wherein the plurality of light output regions and the plurality of non-output regions are formed along the length of the infrared light reflecting tubes;

wherein the infrared light emitted from the infrared lamps is irradiated along the length of the infrared light reflecting tubes, and

wherein the plurality of non-output regions are entirely made of a material reflecting infrared light;

wherein the plurality of light output regions comprise a first light output regions poisoned at a first row of the infrared light reflecting tubes, second light output regions poisoned at a second row of the infrared light reflecting tubes and third light output regions poisoned at a third row of the infrared light reflecting tubes;

wherein both a portion of one second light output region and a portion of the other second light output region are positioned between the corresponding first output region and third output region facing each other;

wherein the one second output region is adjacent with the other second output region;

wherein one first light output region positioned at the end of the infrared light reflecting tubes is smallest among the first output regions;

wherein one third light output region positioned at the end of the infrared light reflecting tubes is smallest among the third output regions.

2. The touch panel display device according to claim 1, wherein each of the infrared light reflecting tubes is formed in a rectangular parallelepiped shape.

3. The touch panel display device according to claim 1, wherein each of the light output regions formed at the surface of each of the infrared light reflecting tubes has a rectangular shape.

4. The touch panel display device according to claim 1, wherein the image sensors are disposed on the upper edges of the liquid crystal panel.

5. The touch panel display device according to claim 4, wherein the liquid crystal panel is formed in a rectangular shape including four sides,

and wherein the image sensors provided on the upper edges of the liquid crystal panel are positioned on any one of the four sides of the liquid crystal panel, or are positioned on corners at which the adjacent sides of the liquid crystal panel join.

6. The touch panel display device according to claim 1, further comprising:

at least one of the image sensors is disposed on a center portion of each of the upper edges of the liquid crystal panel.

7. The touch panel display device according to claim 1, wherein the inner surface of the infrared light reflecting tubes to which the infrared light is irradiated, is coated with a reflective material.

8. The touch panel display device according to claim 1, wherein the back light unit comprising:

a plurality of lamps to irradiate light to the liquid crystal panel;

a bottom cover mounted with lamps and an optical member for guiding the light emitted from the lamps to a liquid crystal display;

lamp holders coupled to the bottom cover to support the lamps;

a side frame positioned above the bottom cover;

a transparent plate provided above the side frame to support the liquid crystal panel; and

a spacer provided above the transparent plate;

wherein the infrared light reflecting tubes are provided above the spacer.

9. The touch panel display device according to claim 1, wherein each of the infrared light reflecting tubes has a width of 2 to 10 mm and a height of 2 to 10 mm.

10. The touch panel display device according to claim 1,

wherein the infrared lamps have an output of 160 to 200 mW;

and

wherein the infrared lamps are arranged at a regular gap of 150 mm therebetween in a longitudinal direction of the infrared light reflecting tubes.