Projection surface with reflective elements for non-visible light

• US 9,041,691 B1
• Filed: 02/11/2013
• Issued: 05/26/2015
• Est. Priority Date: 02/11/2013
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Rawles, LLC (Amazon.com, Inc.)
• Inventors: Haskin, Menashe, Velusamy, Kavitha, Yao, Ning, Kamarshi, Vijay, Sjoberg, Robert Warren, Arthur, Kevin Wayne
• Primary Examiner(s): Johnson, Gerald
• Assistant Examiner(s): KOHLMAN, CHRISTOPHER J
• Application Number:
  US13/764,647
• Time in Patent Office: 834 Days
• Field of Search: 359/443, 359/449, 359/452, 359/459
• US Class Current: 345/175
• CPC Class Codes: G03B 21/26 Projecting separately subsidiary matter simultaneously with main image
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G03B 21/60 characterised by the nature of the surface
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386

Abstract

A passive projection screen presents images projected thereon by a projection system. A surface of the screen includes elements that are reflective to non-visible light, such as infrared (IR) light. When non-visible light is directed to the screen, the non-visible light is reflected by the reflective elements back. Part of the reflected light may contact and reflect from a user'"'"'s fingertip or hand (or other object, such as a stylus) while another part is reflected to the projection system. The projection system differentiates among distances to the surface and distances that include the additional travel to the fingertip. As the fingertip moves closer to the surface, the distances approach equality. When the distances are approximately equal, the finger is detected as touching the surface. In this manner, a projection surface equipped with reflective elements facilitates more accurate touch detection.

Claims

1. A system comprising:

a projector to project images using visible light;

an infrared (IR) light device to emit IR light;

a passive display screen to present the images projected thereon by the projector, the passive display screen comprising;

a surface to scatter the visible light received from the projector and thereby present the images; and

a plurality of reflective elements on the surface, the plurality of reflective elements being configured to reflect the IR light;

a depth sensor to capture the IR light reflected by at least some of the reflective elements of the passive display screen, the depth sensor generating data used to compute distances to the surface; and

wherein at least a portion of the IR light emitted by the IR light device is reflected by at least some of the reflective elements of the passive display screen onto a hand when the hand is proximal to the passive display screen and the distances derived from the data generated by the depth sensor is used to determine if the hand touches the surface.

2. The system of claim 1, wherein the plurality of reflective elements of the passive display screen are clustered in one or more areas on the surface.

3. The system of claim 1, wherein the plurality of reflective elements of the passive display screen are arranged in a pattern on the surface.

4. The system of claim 1, wherein the depth sensor comprises a time-of-flight sensor.

5. The system of claim 1, wherein a first distance is derived from the data associated with IR light reflected by at least a first portion of the reflective elements of the passive display screen back to the depth sensor and a second distance is derived from the data associated with the IR light reflected by at least a second portion of the reflective elements onto the hand.

6. The system of claim 5, wherein a touch is determined to occur when the first and second distances are substantially equal.

7. The system of claim 1, wherein the data generated by the depth sensor is used to detect a gesture made by the hand relative to the surface.

8. A device comprising:

a passive display screen to present images projected thereon from a projector, the passive display screen comprising;

a substrate;

a surface of the substrate to scatter visible light received from the projector to present the images; and

a plurality of reflective elements on the surface, the plurality of reflective elements being configured to reflect non-visible light such that when an object is moved proximal to the passive display screen, the non-visible light is reflected by at least a portion of the reflective elements onto the object for use in detection of proximity of the object to the surface.

9. The device of claim 8, wherein the non-visible light comprises infrared light.

10. The device of claim 8, wherein the plurality of reflective elements are clustered in one or more areas on the surface.

11. The device of claim 8, wherein the plurality of reflective elements are arranged in a pattern on the surface.

12. The device of claim 8, wherein the passive display screen further comprises a raised portion that forms a border around the surface, and the reflective elements being on the raised portion.

13. The device of claim 8, wherein each of the reflective elements comprises at least one of an annular perimeter or a polygonal perimeter.

14. The device of claim 8, wherein each of the reflective elements comprises at least one of a flat reflection surface or a paraboloidal reflection surface.

15. The device of claim 8, wherein individual reflective elements within the plurality of reflective elements are angled relative to one another.

16. The device of claim 8, wherein the object comprises a human finger.

17. A method comprising:

emitting non-visible light toward a projection screen, the projection screen having a plurality of reflective elements that reflect the non-visible light;

capturing a first portion of the non-visible light reflected by the reflective elements on the projection screen;

deriving a first distance from the first portion of the reflected non-visible light, the first distance being indicative of a distance to the projection screen;

capturing a second portion of the non-visible light that is reflected by the reflective elements onto an object;

deriving a second distance from the second portion of the reflected non-visible light, the second distance being indicative of a combined distance to the projection screen and from the projection screen to the object; and

determining when the object contacts the projection screen based at least in part on the first and second distances.

18. The method of claim 17, wherein determining when the object contacts the projection screen comprises declaring a contact when a difference between the first and second distances are within a predefined range.

19. The method of claim 17, wherein determining when the object contacts the projection screen comprises declaring a contact when the first and second distances are approximately equal.

20. The method of claim 17, wherein the object comprises a human finger.

21. The method of claim 17, wherein the object comprises a stylus.

22. The method of claim 17, further comprising detecting a gesture made by a human relative to the projection screen based at least in part on the first and second distances.