Using a light pointer for input on an interactive display surface

• US 20060244719A1
• Filed: 04/29/2005
• Published: 11/02/2006
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Wilson, Andrew D., Kurlander, David Joshua, Keam, Nigel S., Brigham, Robert Allan II
• Granted Patent: US 7,499,027 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• 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 light pointer is selectively activated to direct a light beam onto an interactive display surface, forming a pattern of light that is detected by a light sensor disposed within an interactive display table. The waveband of the light produced by the light pointer is selected to correspond to a waveband to which the light sensor responds, enabling the light sensor to detect the position of the pattern on the interactive display surface, as well as characteristics that enable the location and orientation of the light pointer to be determined. Specifically, the shape and size of the pattern, and the intensity of light forming the pattern are detected by the light sensor and are processed to determine the orientation of the light pointer and its distance from the interactive display surface. The pattern may comprise various shapes, such as circles, arrows, and crosshairs.

Claims

1. A method for providing an input to an interactive display system, wherein the interactive display system includes an interactive display surface and is able to display images and detect objects that are proximate to the interactive display surface, comprising the steps of:

(a) enabling a user to provide an input by directing light from a light source onto the interactive display surface to illuminate a portion thereof with the light from the light source; and

(b) detecting the light illuminating the portion of the interactive display surface with a light sensor that is also used for detecting light reflected from objects that are proximate to the interactive display surface, the light sensor producing a signal that is input to the interactive display system.

2. The method of claim 1, further comprising the step of determining a disposition and orientation of the light source based on characteristics of the signal that is produced by the light sensor, in response to a pattern with which the portion of the interactive display surface is illuminated by the light source.

3. The method of claim 2, wherein the step of determining the disposition and the orientation of the light source comprises the step of determining a shape and an orientation of the pattern on the interactive display surface.

4. The method of claim 3, wherein the step of determining the disposition and the orientation of the light source further comprises the step of determining a relative intensity of the light within the pattern between opposite ends of the pattern, a higher intensity at one end of the pattern indicating that said one end of the pattern is closer to the light source than an opposite end of the pattern.

5. The method of claim 3, wherein the pattern is circular in shape when the light source directs the light onto the portion of the interactive display surface along a path that is normal to the interactive display surface, and the pattern is elliptical in shape when the light source directs the light onto the portion of the interactive display surface along a path that is not normal to the interactive display surface.

6. The method of claim 3, wherein the step of determining the disposition and the orientation of the light source further comprises the step of determining a distance of the light source from the interactive display surface based upon a size of the pattern.

7. The method of claim 3, wherein the pattern comprises at least one of a crosshair, a projected pointing shape, a rotationally symmetrical shape, and a non-rotationally symmetrical projected shape.

8. The method of claim 7, wherein when the pattern comprises a crosshair, further comprising the step of determining the orientation of the light source based upon an angle between lines of the crosshair.

9. The method of claim 1, further comprising the step of modulating the light produced by the light source to provide a different input to the interactive display system than is provided using light from the light source that is not modulated.

10. An interactive display system that is responsive to an input signal comprising a light pattern, comprising:

(a) an interactive display surface on which images are displayed;

(b) a portable light source that produces a light pattern that is selectively capable of being directed by a user onto a portion of the interactive display surface from a selected position and a selected orientation;

(c) a light sensor that responds to light received from the interactive display surface, producing an input signal;

(d) a memory in which machine instructions are stored;

(e) a processor that is coupled to the light sensor to receive the input signal, the processor executing the machine instructions to carry out a plurality of functions, including;

(i) processing the input signal to determine location and a shape of the light pattern on the interactive display surface; and

(ii) based upon the shape of light pattern that was determined, determining the selected orientation of the portable light source.

11. The interactive display system of claim 10, wherein the processor executing the machine instructions further carries out the functions of:

(a) determining a relative intensity of the light within the pattern to determine one end of the pattern that is closer to the portable light source, because the intensity is greater at the one end than an opposite end; and

(b) determining the selected position of the portable light source based upon the relative intensity and the orientation of the light source.

12. The interactive display system of claim 10, wherein the portable light source produces a pattern that is at least one of:

(a) circular shape when directed along a path toward the interactive display surface that is normal to the interactive display surface, but an elliptical shape when the path is not normal to the interactive display surface;

(b) a symmetrical shape that is not circular and non-ellipsoidal;

(c) a crosshair;

(d) a projected pointing shape;

(e) a rotationally symmetrical shape; and

(f) a shape that is not rotationally symmetrical.

13. The interactive display system of claim 10, wherein the portable light source includes at least one of a visible light emitting source, a light emitting source that is not visible to a human, and a coherent light emitting source.

14. The interactive display system of claim 10, wherein the portable light source includes a switch that is selectively activatable to energize a light emitting source.

15. The interactive display system of claim 10, wherein the portable light source includes a modulator that modulates light emitted by the portable light source, and wherein light sensor detects a modulation of the light in the pattern produced by the portable light source, and in response, the machine instructions cause the processor to carry out a predefined function.

16. A portable, hand-held light source for providing input to an interactive display system that includes an interactive display surface and is able to display images and detect objects that are proximate to the interactive display surface, comprising:

(a) a housing;

(b) a battery power supply disposed in the housing;

(c) a light emitting source disposed in the housing so as to emit light; and

(d) a switch disposed in the housing and coupled between the battery power supply and the light emitting source, the switch being selectively activated by a user to energize the light emitting source so that it emits light in a waveband to which the interactive display system is sensitive, enabling a user to direct the light emitted by the light emitting source onto the interactive display surface to form a pattern on a selected portion of the interactive display surface that provides an input to the interactive display system, a shape and relative intensity of the light comprising the pattern indicating a location of the portable, hand-held light source relative to the interactive display surface.

17. The portable, hand-held light source of claim 16, wherein the light emitting source comprises a light emitting diode.

18. The portable, hand-held light source of claim 16, wherein the light emitting source comprises a coherent light source.

19. The portable, hand-held light source of claim 16, wherein the pattern comprises at least one of:

(a) circular shape when directed along a path toward the interactive display surface that is normal to the interactive display surface, but an elliptical shape when the path is not normal to the interactive display surface;

(b) a symmetrical shape that is not circular and non-ellipsoidal;

(c) a crosshair;

(d) a projected pointing shape;

(e) a rotationally symmetrical shape; and

(f) a shape that is not rotationally symmetrical.

20. The portable, hand-held light source of claim 16, further comprising a modulator that modulates the light emitted by the light emitting source according to a predefined modulation.