Touch Sensitive Holographic Displays

• US 20110251905A1
• Filed: 12/03/2009
• Published: 10/13/2011
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Promethean Limited (Best Assistant Education Group Co.)
• Original Assignee: Light Blue Optics Ltd (Lifesize Communications Incorporated)
• Inventors: Routley, Paul R., Cable, Adrian James, Lawrence, Nicholas A.
• Granted Patent: US 8,514,194 B2
• Time in Patent Office: Days
• US Class Current: 705/15
• CPC Class Codes: G03H 1/0005 Adaptation of holography to specific applications holographic optical element G02B5/32; holographic scanner G02B26/106; recognition using holographic mask G06V10/88; holographic memories G11B7/0065, G11C13/042
• CPC Class Codes: G03H 1/2205 using downstream optical component
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 2001/0061 in haptic applications when the observer interacts with the holobject
• CPC Class Codes: G03H 2001/2213 Diffusing screen revealing the real holobject, e.g. container filed with gel to reveal the 3D holobject
• CPC Class Codes: G03H 2001/2215 Plane screen
• CPC Class Codes: G03H 2001/2221 Screen having complex surface, e.g. a structured object
• CPC Class Codes: G03H 2001/2271 RGB holobject
• CPC Class Codes: G03H 2210/22 2D SLM object wherein the object beam is formed of the light modulated by the SLM SLM per se G03H2001/0224
• CPC Class Codes: G03H 2210/441 Numerical processing applied to the object data other than numerical propagation synthesizing propagation G03H1/0808
• CPC Class Codes: G06F 1/3231 Monitoring the presence, absence or movement of users
• CPC Class Codes: G06F 3/042 by opto-electronic means
• 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
• CPC Class Codes: G06F 3/0426 tracking fingers with respect to a virtual keyboard projected or printed on the surface virtual keyboards on touch screens G06F3/04886
• CPC Class Codes: G06Q 50/12 Hotels or restaurants
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

We describe a touch sensitive holographic image display device for holographically projecting a touch sensitive image at an acute angle onto a surface on which the device is placed. The device includes holographic image projection optics comprising at least one coherent light source illuminating a spatial light modulator (SLM), output optics to project a hologram onto an acute angle surface, and a remote touch sensing system to remotely detect a touch of a location within or adjacent to the holographically displayed image. A control system is configured to provide data defining an image for display, to receive detected touch data, and to control the device responsive to remote detection of a touch of a the displayed image.

Claims

1. A touch sensitive holographic image display device for holographically projecting a touch sensitive displayed image at an acute angle onto a surface on which the device is placed, the device comprising:

holographic image projection optics comprising at least one coherent light source;

a remote touch sensing system to remotely detect a touch of a location within or adjacent to said displayed image and having a touch data output to provide detected touch data; and

a configuration having a first input coupled to receive said detected touch data wherein said control system is configured to control said device responsive to remote detection of a touch of a said location within or adjacent to said displayed image; and

wherein the device further comprises;

a device data input to receive data defining an image for display;

wherein said holographic image projection optics comprises a spatial light modulator (SLM) illuminated by said coherent light source and output optics to project modulated coherent light from said SLM onto said surface at said acute angle; and

wherein said control system includes memory for storing said data defining said image for display and has a second input coupled to receive said data defining said image for display and an output for driving said SLM to display hologram data on said SLM to replay said displayed image on said surface.

2. A touch sensitive holographic image display device as claimed in claim 1 wherein said data defining said image for display comprises hologram data defining at least one hologram for display on said SLM to replay a target image distorted to compensate for projection onto said surface at said acute angle.

3. A touch sensitive holographic image display device as claimed in claim 2 wherein said hologram data defines a plurality of, temporal holographic subframes each for display on said SLM, each encoding said image for display, and wherein said control system is configured to display said temporal holographic subframes in rapid succession such that the corresponding replayed images average in an observer'"'"'s eye to give the impression of a reduced-noise displayed image.

4. A touch sensitive holographic image display device as claimed in claim 1 wherein said data defining said image for display comprises image data, the device further comprising a processor configured to:

input said image data;

convert said input image data to target image data;

generate from said target image data hologram data for display as a hologram on said spatial light modulator to reproduce a target image corresponding to said target image data; and

output said hologram data for said spatial light modulator; and

wherein said target image is distorted to compensate for said protection of said hologram at an acute angle to form said displayed image.

5. A touch sensitive holographic image display device as claimed in claim 4 wherein the device is configured to, in operation, rest against said surface with said output optics at a defined height from said surface, and wherein said distortion of said target image compensates for a combination of said acute angle and said defined height.

6. A touch sensitive holographic image display device as claimed in claim 5 wherein said control system is configured to change said displayed image responsive to said remote detection of a touch.

7. A touch sensitive holographic image display device as claimed in claim 4, wherein said conversion of said input image data to said target image data comprises mapping pixels of said target image data to pixels of said input image data and looking up values for said pixels of said target image data in said input image data.

8. A touch sensitive holographic image display device as claimed in claim 4, wherein said conversion of said input image data to said target image data comprises mapping pixels of said input image data to pixels of said target image data have values dependent on a single pixel of said input image data and additionally or alternatively such that a single pixel of said target image data has a value dependent on values of a plurality of pixels of said input image data.

9. A touch sensitive holographic image display device as claimed in claim 4 wherein said conversion of said input image data to said target image data further comprises compensating for variations in per unit area brightness of said image due to said acute angle protection.

10. A touch sensitive holographic image display device as claimed in claim 4 wherein said projected image comprises a multicolor image, wherein said illumination system comprises a multicolor illumination system, wherein said conversion of said input image data to said target image data comprises compensating for different scaling of different color components of said multicolor projected image due to said holographic projection.

11. A touch sensitive holographic image display device as claimed in claim 10 wherein said compensating further comprises compensating for different aberrations of said different color components by spatial mapping of said aberrations for a said color component.

12. A touch sensitive holographic image display device as claimed in claim 4 wherein said processor is configured to generate from said target image data hologram data for display by omitting to process portions of target image space in which said target image data is located from which data for said image is absent.

13. A touch sensitive holographic image display device as claimed in claim 6 where said processor is configured to generate a plurality of temporal holographic subframes for display in rapid succession said that corresponding temporal subframe images average in an observer'"'"'s eye to give the impression of a reduced-noise displayed image.

14. A touch sensitive holographic image display device as claimed in claim 1 wherein said acute angle is less than 65 o, 50 o or 45 o.

15. A touch sensitive holographic image display device as claimed in claim 1 wherein said remote touch sensing system comprises an optical remote touch sensing system.

16. A touch sensitive holographic image display device as claimed in claim 15 wherein said optical remote touch sensing system shares part of said holographic image projection optics.

17. A touch sensitive holographic image display device as claimed in claim 15 wherein said optical remote touch sensing system comprises infrared illumination optics to provide illumination in a region above said surface on which said image is displayed, and location sensing optics to detect light from touching said displayed image through said illuminated region.

18. A touch sensitive holographic image display device as claimed in claim 17 wherein said illuminated region comprises a sheet above said surface and wherein said location sensing optics is configured to detect scattered light from said sheet.

19. A touch sensitive holographic image display device as claimed in claim 17 wherein said location sensing optics comprises a sensor for optical time-of-flight ranging.

20. A touch sensitive holographic image display device as claimed in claim 1 where said remote touch sensing system comprises an acoustic touch sensing system.

21. A touch sensitive holographic image display device as claimed in claim 1 wherein said detected touch data comprises location data identifying a position of a detected touch on displayed image, and wherein said remote touch sensing system includes a system to compensate for keystone distortion of said position of said detected touch in relation to said displayed image arising from said acute angle projection.

22. A touch sensitive holographic image display device as claimed in claim 1 wherein said control system is further configured to display a calibration image to enable a user to collaborate positions of one or more touch sensitive locations on said displayed image to compensate for variable keystone distortion of said displayed image.

23. A touch sensitive holographic image display device as claimed in claim 1 wherein said spatial light modulator is a reflective spatial light modulator.

24. A touch sensitive holographic image display device as claimed in claim 23 wherein said projection optics defines two antiparallel optical paths for said coherent light, one towards and one away from said reflective SLM via a shared beamsplitter.

25. A touch sensitive holographic image display device as claimed in claim 1 wherein said output optics comprises an off-axis lens.

26. A touch sensitive holographic image display device as claimed in claim 1 wherein said projection optics is configured to form an intermediate image at an intermediate image surface, said intermediate image corresponding to a distorted version of said displayed imaged, and wherein said projection optics further comprises a diffuser located at said intermediate image surface and an actuator mechanically coupled to said diffuser.

27. A touch sensitive holographic image display device as claimed in claim 26 wherein said diffuser comprises a pixellated, quantised phase diffuser.

28. A touch sensitive holographic image display device as claimed in claim 1 wherein said control system is configured to change said displayed image responsive to said remote detection of a touch.

29. A touch sensitive holographic image display device as claimed in claim 1 wherein said control system is configured to send a wireless message to a remote computer system image responsive to said remote detection of a touch.

30. A restaurant menu display and food ordering device comprising a touch sensitive holographic image display device as recited in any preceding claim, wherein said memory stores data for a plurality of menus for display together with menu link data defining links between the menus, and price data, and further comprising a bidirectional communications link for receiving said price data and for transmitting a customer order, wherein said system controller is configured to display selected said menus response to a said customer touching menu link regions of said displayed menus, a said menu link region being associated with said link data to define selected menu to display in response to detection of touching of a said link region, and to input an order for one or both of food and drink by detection of said customer touching one or more touch sensitive order regions of a said menu displayed by the display device, and to transmit said order to a remote computer system for output for fulfilling the order.

31. A restaurant menu display and food ordering device as claimed in claim 30 further comprising means for a customer to identify themselves to said remote computer system using the device, and means to receive and display customer-specific data for said identified customer.

32. A restaurant menu display and food ordering device comprising a touch sensitive holographic image display device, memory storing data for a plurality of menus for display together with menu link data defining links between the menus, and price data, and further comprising a bidirectional communications link for receiving said price data and for transmitting a customer order, and a system controller configured to display selected said menus response to a said customer touching menu link regions of said displayed menus, a said menu link region being associated with said link data to define selected menu to display in response to detection of touching of a said link region, and to input an order for one or both of food and drink by detection of said customer touching one or more touch sensitive order regions of a said menu displayed by the display device, and to transmit said order to a remote computer system for output for fulfilling the order.

33. A touch sensitive holographic image display device for holographically projecting a touch sensitive displayed image onto a curved display surface, the device comprising:

a spatial light modulator (SLM) to display a hologram;

an illumination system to illuminate said displayed hologram;

projection optics to project light from said illuminated displayed hologram onto said display surface to form said image; and

a processor having an input to received image data for display and having an output for driving said SLM, and wherein said processor is configured to process said image data to generated hologram data for display on said SLM to form said image on said display surface;

non-volatile data memory coupled to said processor to store wavefront correction data for said display surface;

wherein said processor is configured to apply a wavefront correction responsive to said stored wavefront correction data when generating said hologram data to correct said image for aberration due to a shape of said display surface;

a touch sensing system to detect touch of said display surface and having a touch data output to provide detected touch data; and

a control system configured to control said device responsive to detection of a touch of said displayed image.

34. A touch sensitive holographic image display device as claimed in claim 33 wherein said touch sensing system comprises a system to detect scattered light resulting from touching said display surface.

35. A touch sensitive holographic image display device as claimed in claim 33 wherein said touch sensing system comprises a system to detect touching of said display surface by acoustic means.

36. A touch sensitive holographic image display device as claimed in claim 33, wherein said touch sensing system is configured to detect a location of said touch, and wherein said detected touch data includes touch location data.

37. A touch sensitive holographic image display device as claimed in claim 33 wherein said surface comprises a light transmissive screen, and wherein said projection optics are configured to project onto a rear surface of said light transmissive screen.

38. A touch sensitive holographic image display device as claimed in claim 33 wherein said control system is configured to change said displayed image responsive to said detection of a touch.