Protected touch panel display system

• US 6,864,882 B2
• Filed: 03/22/2001
• Issued: 03/08/2005
• Est. Priority Date: 05/24/2000
• Status: Expired due to Fees

• Current Assignee: Smart Technologies ULC (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Next Holdings Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Newton, John
• Primary Examiner(s): Shankar, Vijay
• Assistant Examiner(s): Shapiro, Leonid
• Application Number:
  US09/815,163
• Publication Number:
  US 20020118177A1
• Time in Patent Office: 1,447 Days
• Field of Search: 345156-157, 345/173, 345/175, 345/178, 178 1801- 1809, 178/20.01
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen

Abstract

A display screen is positioned relative to the interior side of a protective barrier. Also positioned relative to the interior side of the protective barrier are emitters adapted for emitting energy beams and detectors adapted for detecting the energy beams. Emission guides positioned relative to the exterior side of the protective barrier are adapted to receive the energy beams and to channel the energy beams across the exterior side of the protective barrier and through to the interior side of the protective barrier for detection. The display screen, the emitters and the detectors may not be accessible from the exterior side of the protective barrier. A touch on the exterior side of the protective barrier will interrupt at least two energy beams. The location of the touch on the exterior side of the protective barrier may be calculated based on the interrupted energy beams.

Claims

1. A protected touch panel display system comprising:

a protective barrier through which light and energy can be emitted, the protective barrier having an interior side and an exterior side;

a display screen for displaying information, the display screen positioned relative to the interior side of the protective barrier;

a plurality of emitters positioned relative to the interior side of the protective barrier, each of the emitters adapted for emitting energy beams;

a plurality of detectors positioned relative to the interior side of the protective barrier and each adapted to a generate a detection signal upon detecting any one of the energy beams;

at least one emission guide positioned relative to the exterior side of the protective barrier and adapted to receive the energy beams from the interior side of the protective barrier and to channel the received energy beams across the exterior side of the protective barrier and through to the interior side of the protective barrier for detection by at least one of the detectors;

a computer-readable medium for storing detection maps indicating which of the detectors should be receiving one of the energy beams from at least one of the emitters at any point in time; and

a processor for executing computer-executable instructions for;

generating a reference detection map based on the detection signals generated by the detectors and storing the reference detection map on the computer-readable medium,

periodically generating a current detection map based on the detection signals generated by the detectors at a current point in time, wherein the current detection map and the reference detection map are generated at different times,

accessing the computer-readable medium to compare the current detection map to the reference detection map in order to determine an absence of expected detection signals from at least one of the detectors,

based on the absence of the expected detection signals, determining that at least two of the energy beams have been interrupted by a touch of the protective barrier, and

based on the at least two interrupted energy beam, determining the location of the touch on the protective barrier.

2. The protected touch panel display system of claim 1, wherein the reference detection map comprises an average of several previously stored detection maps.

3. The protected touch panel display system of claim 1, wherein the processor executes further computer executable instructions for controlling activation of the emitters.

4. The protected touch panel display system of claim 3, wherein controlling activation of the emitters comprises controlling the emitters to emit the energy beams in a cycle such that each emitter is activated and deactivated according to a sequence.

5. The protected touch panel display system of claim 4, wherein the cycle is rapid enough to substantially ensure that a plurality of the energy beams will be interrupted by a touch of the protective barrier, each of the interrupted energy beams being emitted by different ones of the emitters at different times.

6. The protected touch panel display system of claim 3, wherein controlling activation of the emitters comprises controlling the duty cycle of the emitters.

7. The protected touch panel display system of claim 6, wherein the detectors are adapted for automatic gain control for adjusting the sensitivity of the detectors in response to a change in the duty cycle of the emitters.

8. The protected touch panel display system of claim 3, wherein the duty cycle of the emitters is changed depending on ambient light levels.

9. The protected touch panel display system of claim 1, wherein each of the detectors is capable of detecting the energy beams transmitted by the emitters over a range of angles.

10. A method for implementing a protected touch panel display screen comprising:

providing a protective barrier through which light and energy can be emitted, the protective barrier having an interior side and an exterior side;

positioning a display screen relative to the interior side of the protective barrier, the display screen adapted for displaying information;

positioning a plurality of emitters relative to the interior side of the protective barrier, each of the emitters adapted for emitting energy beams;

positioning a plurality of detectors relative to the interior side of the protective barrier, each of the detectors adapted to receive the energy beams over a range of angles and to generate a detection signal upon detecting any one of the energy beams, wherein the number of detectors is less than the number of emitters, such that not every emitter is aligned on-axis with a corresponding detector;

positioning at least one emission guide relative to the exterior side of the protective barrier, the at least one emission guide adapted to receive the energy beams from the interior side of the protective barrier and to channel the received energy beams across the exterior side of the protective barrier and through to the interior side of the protective barrier for detection by at least one of the detectors; and

wherein the plurality of emitters and the plurality of detectors are positioned such that the energy beams channeled across the exterior side of the protective barrier substantially cover the display screen, so that a touch of the protective barrier at any location relative to the display screen can be detected.

11. The method of claim 10, wherein the display screen, the emitters and the detectors are not accessible from the exterior side of the protective barrier.

12. The method of claim 10, wherein signage is displayed on the interior side of the protective barrier so as to be visible from the exterior side of the protective barrier;

and

wherein the plurality of emitters and the plurality of detectors are positioned such that the energy beams channeled across the exterior side of the protective barrier substantially cover the display screen and the signage, so that a touch of the protective barrier at any location relative to the display screen or the signage can be detected.

13. The method of claim 10, wherein a the touch of the protective barrier will interrupt at least two of the energy beams and will cause at least one of the detectors to not detect the at least two interrupted energy beams.

14. The method of claim 13, further comprising determining a location of the touch on the protective barrier based on the interrupted energy beams.

15. The method of claim 10, further comprising controlling an activation cycle of the emitters such that each emitter is activated and deactivated according to a sequence.

16. The method of claim 15, wherein the activation cycle of the emitters is rapid enough to substantially ensure that a plurality of the energy beams will be interrupted by a touch of the protective barrier, each of the interrupted energy beams being emitted by different ones of the emitters at different times.

17. The method of claim 10, further comprising positioning at least one interior emission guide relative to the interior side of the protective barrier, the at least one interior emission guide adapted to receive the energy beams from at least one of the emitters and channel the energy beams through to the exterior side of the protective barrier.

18. The method of claim 10, further comprising positioning at least one interior emission guide relative to the interior side of the protective barrier, the at least one interior emission guide adapted to receive the energy beams from the exterior side of the protective barrier and to channel the energy beams to at least one of the detectors.

19. The method of claim 10, further comprising changing a duty cycle of the emitters depending on ambient light levels.

20. The method of claim 19, further comprising adapting the detectors for automatic gain control for adjusting the sensitivity of the detectors in response to a change in the duty cycle of the emitters.

21. The method of claim 10, wherein the protective barrier comprises a layer of glass.

22. The method of claim 21, wherein the layer of glass comprises a window.

23. A protected touch panel display system comprising:

a protective barrier through which light and energy can be emitted, the protective barrier having an interior side and an exterior side;

a display screen for displaying information, the display screen positioned relative to the interior side of the protective barrier;

a plurality of emitters positioned relative to the interior side of the protective barrier, each of the emitters adapted for emitting energy beams;

a plurality of detectors positioned relative to the interior side of the protective barrier, each of the detectors adapted to receive the energy beams over a range of angles and to generate a detection signal upon detecting any one of the energy beams, wherein the number of detectors is less than the number of emitters, such that not every emitter is aligned on-axis with a corresponding detector;

at least one emission guide positioned relative to the exterior side of the protective barrier, the at least one emission guide adapted to receive the energy beams from the interior side of the protective barrier and to channel the received energy beams across the exterior side of the protective barrier and through to the interior side of the protective barrier for detection by at least one of the detectors; and

wherein the plurality of emitters and the plurality of detectors are positioned such that the energy beams channeled across the exterior side of the protective barrier substantially cover the display screen, so that a touch of the protective barrier at any location relative to the display screen can be detected.

24. The protected touch panel display system of claim 23, wherein the display screen, the emitters and the detectors are not accessible from the exterior side of the protective barrier.

25. The protected touch panel display system of claim 23, wherein signage is displayed on the interior side of the protective barrier so as to be visible from the exterior side of the protective barrier;

and

wherein the plurality of emitters are positioned such that the energy beams channeled across the exterior side of the protective barrier substantially cover the display screen and the signage, so that a touch of the protective barrier at any location relative to the display screen or the signage can be detected.

26. The protected touch panel display system of claim 23, wherein the touch of the protective barrier will interrupt at least two of the energy beams and will cause at least one of the detectors to not detect the at least two interrupted energy beams.

27. The protected touch panel display system of claim 26, wherein a location of the touch on the protective barrier is determined based on the interrupted energy beams.

28. The protected touch panel display system of claim 23, further comprising means for controlling an activation cycle of the emitters such that each emitter is activated and deactivated according to a sequence.

29. The protected touch panel display system of claim 28, wherein the activation cycle of the emitters is rapid enough to substantially ensure that a plurality of the energy beams will be interrupted by a touch of the protective barrier, each of the interrupted energy beams being emitted by different ones of the emitters at different times.

30. The protected touch panel display system of claim 23, further comprising at least one interior emission guide positioned relative to the interior side of the protective barrier, the at least one interior emission guide adapted to receive the energy beams from at least one of the emitters and channel the energy beams through to the exterior side of the protective barrier.

31. The protected touch panel display system of claim 23, further comprising a least one interior emission guide positioned relative to the interior side of the protective barrier, the at least one interior emission guide adapted to receive the energy beams from the exterior side of the protective barrier and to channel the energy beams to at least one of the detectors.

32. The protected touch panel display system of claim 23, further comprising means for changing a duty cycle of the emitters depending on ambient light levels.

33. The protected touch panel display system of claim 32, wherein the detectors are adapted for automatic gain control for adjusting the sensitivity of the detectors in response to a change in the duty cycle of the emitters.

34. The protected touch panel display system of claim 23, wherein the protective barrier is constructed from a material selected from the group consisting of glass, plastic, plexi-glass, acrylic and crystal.