Touch-sensing display apparatus and electronic device therewith

• US 8,884,900 B2
• Filed: 07/13/2012
• Issued: 11/11/2014
• Est. Priority Date: 07/13/2011
• Status: Active Grant

• Current Assignee: FlatFrog Laboratories AB
• Original Assignee: FlatFrog Laboratories AB
• Inventors: Wassvik, Ola
• Primary Examiner(s): NGUYEN, JENNIFER T
• Application Number:
  US13/548,749
• Publication Number:
  US 20130021300A1
• Time in Patent Office: 851 Days
• Field of Search: 345173-178, 178 1801- 1809
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A touch-sensing display apparatus comprises a display unit with integrated elements, and a planar light guide located in front of the display unit so as to define a touch surface. At least one light emitter is arranged to emit light into the light guide for propagation by total internal reflection inside the light guide, and at least one light detector is arranged to receive at least part of the light propagating inside the light guide. The integrated elements are designed as image-forming elements and touch-sensor elements, wherein the touch-sensor elements comprise the emitter(s) and/or the detector(s) and are arranged along a periphery region of the display unit. The image-forming elements and the touch-sensor elements may be integrated in one and the same composite substrate within the display unit.

Claims

1. A touch-sensing display apparatus, comprising:

a display unit comprising integrated elements;

a planar light guide located in front of the display unit, so as to define a touch surface;

at least one light emitter arranged to emit light into the light guide for propagation by total internal reflection inside the light guide; and

at least one light detector arranged to receive at least part of the light propagating inside the light guide;

wherein the integrated elements comprise image-forming elements and touch-sensor elements,

wherein the touch-sensor elements comprise at least one of said at least one emitter and said at least one detector and are arranged along a periphery region of the display unit, and

wherein the image-forming elements and the touch-sensor elements together form a single integral structure in which the image-forming elements are only functionally separated from the touch-sensor elements.

2. The touch-sensing display apparatus of claim 1, wherein the image-forming elements and the touch-sensor elements are integrated in one and the same composite substrate within the display unit.

3. The touch-sensing display apparatus of claim 1, wherein the touch-sensor elements are formed from functional structures also present in the display unit for the operation of the image-forming elements.

4. The touch-sensing display apparatus of claim 3, wherein the functional structures comprise at least one of an organic optoelectronic device, an OLED, a TFT, and an LED.

5. The touch-sensing display apparatus of claim 1, wherein the display unit comprises a common electrode arrangement which is connected to both the image-forming elements and the touch-sensor elements.

6. The touch-sensing display apparatus of claim 1, wherein the periphery region is located at a perimeter of a center region of the display unit, said center region comprising said image-forming elements.

7. The touch-sensing display apparatus of claim 1, wherein the image-forming elements are located only in a center region.

8. The touch-sensing display apparatus of claim 1, wherein the touch-sensor elements comprise said at least one emitter and said at least one detector.

9. The touch-sensing display apparatus of claim 8, wherein the light guide is arranged in contact with at least part of the display unit, such that light is coupled between the light guide and the touch-sensor elements.

10. The touch-sensing display apparatus of claim 9, wherein the light guide is attached to the periphery region of the display unit.

11. The touch-sensing display apparatus of claim 9, wherein the light guide is attached to the image-forming elements by a first material and to the touch-sensor elements by a second material, wherein the first material is configured to sustain the total internal reflection inside the light guide and the second material is configured to couple light between the light guide and the touch-sensor elements.

12. The touch-sensing display apparatus of claim 9, wherein an air gap is defined between the light guide and the image-forming elements of the display unit.

13. The touch-sensing display apparatus of claim 1, wherein the light guide is attached to the display unit by lamination.

14. The touch-sensing display apparatus of claim 1, wherein the light guide comprises a front cover of the touch-sensing display apparatus.

15. The touch-sensing display apparatus of claim 1, wherein the light guide is formed by a transparent substrate integrated with a top electrode layer of the display unit.

16. The touch-sensing display apparatus of claim 1, further comprising a light-redirecting structure configured to define a field of view of the touch-sensor elements.

17. The touch-sensing display apparatus of claim 16, wherein the light-redirecting structure is included in at least one of the touch-sensor elements, the light guide and a contact material between the periphery region and the light guide.

18. The touch-sensing display apparatus of claim 1, further comprising a surface structure on a periphery portion of the light guide for preventing impinging light from being reflected back into the light guide.

19. The touch-sensing display apparatus of claim 1, wherein the display unit comprises one or more intermediate organic layers between a first electrode layer and a second electrode layer, wherein the image-forming elements and the touch-sensor elements are formed as selectively addressable portions in said one or more organic layers.

20. The touch-sensing display apparatus of claim 1, wherein the display unit comprises a liquid crystal structure between a first electrode layer and a second electrode layer, the first electrode layer comprising a two-dimensional array of thin-film transistors, wherein at least part of the touch-sensor elements are formed by a subset of the thin-film transistors.

21. The touch-sensing display apparatus of claim 20, wherein the display unit further comprises a backlight for illuminating the liquid crystal structure through the first and second electrode layers, wherein at least part of the touch-sensor elements are integrated in the backlight.

22. The touch-sensing display apparatus of claim 20, wherein the periphery region is located outside a perimeter of the liquid crystal structure.

23. The touch-sensing display apparatus of claim 1, wherein a surface area of each touch-sensor element is larger than a surface area of each image-forming element.

24. The touch-sensing display apparatus of claim 1, further comprising a signal processor configured to process an output signal from said at least one light detector so as to determine touch data for one or more objects in contact with the touch surface, said one or more objects thereby attenuating the light propagating inside the light guide.

25. An electronic device comprising the touch-sensing display apparatus of claim 1, and a controller for causing the image-forming elements to display information content within at least part of the touch surface while causing the touch-sensor elements to provide touch sensitivity within said at least part of the touch surface.