Touchscreen sensor for touchscreen display unit

• US 9,069,414 B2
• Filed: 08/02/2012
• Issued: 06/30/2015
• Est. Priority Date: 08/02/2012
• Status: Expired due to Fees

• Current Assignee: OOO Nanooptic Devices (NanoOptic Devices LLC)
• Original Assignee: Nano-Optic Devices LLC
• Inventors: Yankov, Vladimir
• Primary Examiner(s): Ngo, Tony N
• Application Number:
  US13/565,773
• Publication Number:
  US 20140035878A1
• Time in Patent Office: 1,062 Days
• US Class Current: 1/1
• 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

Proposed is a touchscreen sensor for touchscreen devices such as iPhones, iPads, etc. The sensor comprises a substrate that supports an IR laser light source that transmits light to a light-delivery ridge waveguide formed on one side of the substrate and an array of photoreceivers on the opposite side of the substrate. The light-delivery waveguide and the photoreceivers of the array are interconnected by a plurality of strip-like illumination waveguides that are divided by touch-sensitive detectors into input and output waveguides. The touch-sensitive detectors are distributed under the external plate with a density that changes optical conditions of the touch-sensitive optical detector when an object, e.g., a finger, touches the external plate. The place of contact is detected and is then used to activate the appropriate command.

Claims

1. A touchscreen sensor for a touchscreen device comprising:

a substrate;

a light source attached to the substrate;

a light-delivery unit, which is formed on the substrate and connected to the light source;

a light-receiving unit formed on the substrate;

a plurality of ridge waveguides extending between the light-delivery unit and the light-receiving unit;

a plurality of touch-sensitive optical detectors, each one being formed in one of the ridge waveguides and dividing the respective ridge waveguides into light-input waveguides, which are located between the touch-sensitive optical detector and the light-delivery unit, and light-output waveguides, which are located between the respective detector and the light-receiving unit; and

an external plate that covers at least the ridge waveguides, the touch-sensitive detectors being distributed on the substrate under the external plate with a density that changes optical conditions of the touch-sensitive optical detector when an object touches the external plate.

2. The touchscreen sensor of claim 1, wherein the light source is a laser light source, the light-delivery unit comprises a light-delivery ridge waveguide that is connected to the laser light source, and the light-receiving unit comprises an array of photoreceivers.

3. The touchscreen sensor of claim 2, wherein each touch-sensitive optical detector comprises a pair of optically interacting holograms, one of which is formed on the end of the respective light-input waveguide and the other on the end of the respective light-output waveguide.

4. The touchscreen sensor of claim 1, wherein at least the substrate, the ridge waveguide, and the external plate are transparent.

5. The touchscreen sensor of claim 2, wherein at least the substrate, the ridge waveguide, and the external plate are transparent.

6. The touchscreen sensor of claim 3, wherein at least the substrate, the ridge waveguide, and the external plate are transparent.

7. The touchscreen sensor of claim 1, wherein the light-delivery unit and the light-receiving unit are linear and wherein in a direction parallel to the light-receiving unit the touch-sensitive detectors lie on lines parallel to the light-delivery unit while in the direction from the light-delivery unit toward the light-receiving unit the touch-sensitive detectors lie on oblique lines that are inclined with respect to a perpendicular between the light-delivery unit toward the light-receiving unit.

8. The touchscreen sensor of claim 3, wherein the light-delivery unit and the light-receiving unit are linear and wherein in a direction parallel to the light-receiving unit the touch-sensitive detectors lie on lines parallel to the light-delivery unit while in the direction from the light-delivery unit toward the light-receiving unit the touch-sensitive detectors lie on oblique lines that are inclined with respect to a perpendicular between the light-delivery unit toward the light-receiving unit.

9. The touchscreen sensor of claim 6, wherein the light-delivery unit and the light-receiving unit are linear and wherein in a direction parallel to the light-receiving unit the touch-sensitive detectors lie on lines parallel to the light-delivery unit while in the direction from the light-delivery unit toward the light-receiving unit the touch-sensitive detectors lie on oblique lines that are inclined with respect to a perpendicular between the light-delivery unit toward the light-receiving unit.

10. A touchscreen sensor for a touchscreen display unit comprising:

a transparent substrate having a shape that corresponds to the shape of the display;

a laser light source attached to the transparent substrate;

a light-delivery ridge waveguide formed on said substrate on one side thereof and optically coupled to the laser light source;

a photoreceiver array that has a plurality of photoreceivers and is attached to the side of the substrate opposite to the light-delivery ridge waveguide;

a plurality of light-direction reorientation elements formed on the light-delivery ridge waveguide for reorientation of light that propagates from the laser light source along the light-delivery ridge waveguide to the direction perpendicular to the light-delivery ridge waveguide, the number of light-direction reorientation elements corresponding to the number of photoreceivers;

a plurality of pairs of parallel illumination ridge waveguides that are formed on the substrate adjacent to each other but spaced from each other and that extend between the light-delivery ridge waveguide and the respective photoreceivers, each pair of the illumination ridge waveguides comprising light-input ridge waveguides that are coupled with butt connections to the light-delivery ridge waveguide in the place near the light-direction reorientation elements and light-output ridge waveguides that are connected to the respective photoreceivers, the mating ends of the light-input ridge waveguides that are opposite to the light-delivery ridge waveguide and the ends of the light-output ridge waveguides that are connected to the respective photoreceivers being located in proximity to each other;

a plurality of light-sensitive detectors that comprise a pair of light-sensitive elements formed on the mating ends and that are under conditions of mutual optical interaction; and

an external plate that covers at least the illumination ridge waveguides, the light-sensitive detectors being distributed under the external plate with a density that provides change in the optical mutual interaction between the light-sensitive elements of the light-sensitive detectors when an object is brought in contact or in proximity with the external plate.

11. The touchscreen sensor of claim 10, wherein the laser light source is an IR laser diode operating in an invisible wavelength range.

12. The touchscreen sensor of claim 11, wherein the light-direction reorientation elements are 45°

gratings that redirect light from the light-delivery ridge waveguide to the light-input ridge waveguides.

13. The touchscreen sensor of claim 11, wherein the light-delivery ridge waveguide and the photoreceiver array are linear and wherein in a direction parallel to the light-delivery ridge waveguide the light-sensitive detectors lie on lines parallel to the light-delivery ridge waveguide while in the direction from the light-delivery unit toward the photoreceiver array the light-sensitive detectors lie on oblique lines that are inclined with respect to a perpendicular between the light-delivery ridge waveguide toward the photoreceiver array.

14. The touchscreen sensor of claim 12, wherein the light-delivery ridge waveguide and the photoreceiver array are linear and wherein in a direction parallel to the light-delivery ridge waveguide the light-sensitive detectors lie on lines parallel to the light-delivery ridge waveguide while in the direction from the light-delivery unit toward the photoreceiver array the light-sensitive detectors lie on oblique lines that are inclined with respect to a perpendicular between the light-delivery ridge waveguide toward the photoreceiver array.

15. The touchscreen sensor of claim 10, wherein the light-sensitive elements of the light-sensitive detectors comprise a pair of holograms.

16. The touchscreen sensor of claim 12, wherein the light-sensitive elements of the light-sensitive detectors comprise a pair of holograms.

17. The touchscreen sensor of claim 14, wherein the light-sensitive elements of the light-sensitive detectors comprise a pair of holograms.