WO2017162648A1

WO2017162648A1 - Interactive system

Info

Publication number: WO2017162648A1
Application number: PCT/EP2017/056660
Authority: WO
Inventors: John MACEY; John BRANNAN; Pham NGUYEN
Original assignee: Promethean Limited
Priority date: 2016-03-21
Filing date: 2017-03-21
Publication date: 2017-09-28
Also published as: GB201604747D0; GB2548577A

Abstract

There is provided a display controller comprising : a light source for generating at least two light beams of different wavelengths and different angular offsets; a reflective device to receive the different wavelength beams having different angular offsets and to emit the different wavelength beams substantially coincidental and at a substantially common angle; a reflector array for receiving the different wavelength beams from the reflective device and for generating at least two substantially collinear illumination fields corresponding to the at least two different wavelengths.

Description

INTERACTIVE SYSTEM

BACKGROUND OF THE INVENTION:

Field of the Invention :

The invention relates to the provision and adjustment of an LGA (Light Generating Array or Laser Generator Array) for an interactive surface.

Description of the Related Art:

It is known in the art to provide an interactive surface which provides an illumination field across the interactive surface in order to allow for detection of contact points at the interactive surface . Images are displayed on the interactive surface, and the illumination field is used to detect contact points in order to map the position of those contact points to the displayed images.

The images may be projected onto the surface, or the surface may be an emissive surface on which images are generated .

Such a surface is typically provided by a whiteboard, and an LGA (Light Generating Array or Laser Generator Array) may be mounted to the whiteboard in order to generate the illumination field across the whiteboard surface.

The LGA must be positioned with respect to the surface to ensure that an illumination field is generated across the entire surface, and preferably that the distance of the illumination field from the surface is uniform across the surface .

When an LGA is mounted to a whiteboard care needs to be taken to ensure that it is correctly fitted to provide the necessary illumination field. For this reason there is usually provided an adjustment mechanism to allow the positioning of the LGA to be adjusted in order to correctly generate the illumination field.

The amount of adjustment of the LGA may vary dependent on the nature of the fitting required . The more precisely- manufactured the whiteboard, the less adjustment may be required . However, for fitting to generic whiteboards, or for general fitting to a surface which is used for an interactive display (such as a wall) , careful adjustment of the LGA may be requi red .

It is well known in the prior art that the LGA of such interactive systems produce non-visible light illumination fields, usually in the infra-red spectrum. As these illumination fields are invisible to the naked eye, sophisticated tools and/or methods are required in order to adjust the LGA to ensure that the illumination field is uniform across the surface .

It is an aim of the invention to provide improvements to such an interactive system.

SUMMARY OF THE INVENTION: There is provided a display controller comprising a light source for generating at least two light beams of different wavelengths and different angular offsets, a reflective device to receive the different wavelength beams having different angular offsets and to emit the different wavelength beams substantially coincidental and at a substantially common angle and a reflector array for receiving the different wavelength beams from the reflective device and for generating at least two substantially coilinear illumination fields corresponding to the at least two different wavelengths. ' Substantially' should be understood to mean that the different wavelength beams and/or the illumination fields are, within acceptable tolerances, superimposed on each other to produce a bean and/or illumination field that can be seen as a single coincidental beam and/or illumination field .

The light source generates visible and non-visible light .

The light source may consist of an independent visible light generator and an independent non-visible light generator . The two light generators maybe located in non-concurrent locations .

The light source may further be a single integrated light source incorporating visible and non-visible light generators .

The light source is selectively switchable .

The visible and non-visible light generators work independently .

The light source further generates a collimated beam.

The light source may be chosen from one of a laser, light- emitting electrochemical ceil or light-emitting diode .

The reflective device is a mirror having nonparallel dichroic surfaces .

The reflective device is rotatably adjustable to adjust the angular offset of the different wavelength beams.

The angle of incident with respect to the light source of at least one of the dichroic surfaces of the reflective device changes when the reflective device is rotatably adjusted.

The reflective device further includes a colllmating lens for receiving the different wavelength beams from the reflective device and for providing its output as an input to the reflective array .

The reflector array consists of a reflector assembly and a diffuser assembly.

The reflector assembly of the reflector array is a combination of one or more partial reflectors and a reflector for creating illumination fields .

The one or more partial reflectors and reflector of the reflector assembly of the reflector array are disposed at different angles of incident to the light beam.

The diffuser assembly of the reflector array consists of a plurality of diffusers for diffusing the reflected light from the reflectors, wherein the number of diffusers is equal to the number of reflectors in the reflector assembly of the reflector array .

BRIEF DESCRIPTION OF THE FIGURES:

The present invention is described by way of example with reference to the accompanying figures , in which :

FIG. la and FIG. lb illustrate an exemplary implementation of a display controller in an interactive display system;

FIG. 2 illustrates an exemplary implementation of a display controller;

FIG. 3 illustrates in further detail an exemplary implementation of the reflector device of FIG. 2;

FIG. 4a and FIG. 4b illustrate in further detail the rotation of the reflector device of FIG. 2;

FIG. 5a to FIG. 5c illustrate the illumination field of an interactive display system. DESCRIPTION OF PREFERRED EMBODIMENTS:

The invention is now described by way of example to particular arrangements and examples in which the invention and its aspects and variations may be utilised. The invention is not limited to the details of any arrangement or example, unless explicitly stated herein or defined in the appended claims.

With reference to FIG. 1 there is illustrated a display surface 12 of an interactive whiteboard 10. Also shown is the provision of a display controller 200. The provision of the display controller 200 is not limited to an interactive whiteboard, and the controller 200 may generally be provided on any surface which is to provide an interactive display surface .

For ease of explanation, FIG. 1 does not show any details of any projection and/or sensing equipment. It will be understood that the display controller 200 may or in general may be used in combination with any projection and/or sensing equipment where it is desired to provide an illumination field for an interactive display . The illumination field may be intended to be utilised to provide an object for the sensing equipment to track due to the illumination field being interfered with .

The display controller 200 is provided to illuminate the surface 12 , so as to provide an illumination field or light curtain 800 across the entire surface.

The display controller 200 generates a plurality of substantially overlapping beams from light produced by a light source to produce an illumination field that covers the display field in a substantially contiguous fashion. In a preferred implementation, the display controller 200 generates an illumination field of four overlapping beams using light from the light source . An exemplary implementation of the display controller 200 is illustrated in FIG . 2 .

As illustrated in FIG . 2 , the display controller comprises a light source 210 , a collimating lens 610, a reflective device 300, a collimating lens 620, three partial reflectors 400a to 400c, a reflector 410, and four diffusers 500a to 500d.

In the preferred implementation as illustrated in FIG . 2 , the light source 210 is a laser diode, although a person skilled in the art will understand that the light source may additionally be chosen from any suitable light generator such as a light - emitting electrochemical cell or light-emitting diode .

The light source 210 generates both visible and non-visible light . In the preferred implementation, the light source is a single chip switchable laser diode that can be switched between generating visible and non-visible light or can produce visible and non-visible light simultaneously. However, in further implementations, the light source may consist of a plurality of single light generators . The individual light generators may be placed in any suitable orientation, although preferably the light generators are placed side-by-side.

In the illustrated embodiment, the light source 210 is an individual light generator producing either visible 320b, non- visible light 320a or both . In an alternative embodiment, the light source can be switched between individual light generators .

The visible 320b and non-visible 320a light generated by the light source 210 have different wavelengths and angular offsets with respect to each other, as illustrated in FIG . 2. The visible light generated by the light source may have a wavelength of between 380nm and 750nm. In a preferred embodiment the visible light generated by the light source may have a wavelength of between 450nm and 750nm. In a more preferred embodiment the visible light generated by the light source may have a wavelength of between 620nm and 750nm (red light) . In a further preferred embodiment the visible light generated by the light source may have a wavelength of between 450nm and 495nm (blue light) . In a preferred embodiment the non-visible light generated by the light source is infrared light having a wavelength of between 700nm and 1mm.

As illustrated in FIG. 2 , the light generated by light source 210 is collimated by collimating lens 610. The collimating lens narrows the rays of the visible and non-visible light generated by the light source so that the rays of the visible and non-visible light beams exiting the collimating lens are more parallel than when they entered the collimating lens but the angular offset between the visible and non-visible beams is maintained .

The collimated beam is reflected by reflective device 300. Reflective device 300 is a mirror having dichroxc surfaces 310a and 310b, as illustrated in FIG. 3. The dichroic surfaces 310a and 310b are selected so that beams of specific wavelengths are reflected. As illustrated in FIG. 3, the front dichroic surface 310a is selected not only to reflect a specific wavelength beam 320a but also to transmit the non-reflected wavelength beams to the rear dichroic surface 310b . In this way the angular offsets of the different wavelength beams are adjusted such that the reflected beams have a substantially common angle . Thus there is produced a single substantially coincidental beam 330.

In the preferred embodiment as illustrated in FIG. 3, the dichroic surfaces 310a and 310b of the reflective device 300 are non-parallel and designed to reflect visible 320b and non- visible 320a light respectively. However, it should be noted that the beam to be reflected by the dichroic surfaces is interchangeable and is dependent upon which wavelength is required to be adjusted to create the resulting substantially coincidental beam 330.

As illustrated in FIGs 4a and 4b, the reflective device 300 is rotatable around an axis 700 that is perpendicular to the front dichroic surface 310a of the reflective device 300, so that the coincidence between the visible and non-visible light can be optimised. As the reflective device 300 rotates, the angle with respect to the light source of the rear dichroic surface 310b changes due to its wedge shape, whilst the angle with respect to the light source of the front dichroic surface 310a remains constant , allowing the coincidence of visible and non-visible light to be aligned with greater accuracy.

The coincidental beam 330 produced by the reflective device 300, is collimated by collimating lens 620. The collimating lens narrows the rays of the coincidental bean produced by the reflective device so that the rays emitting from the collimating lens are more parallel than when they entered the collimating lens .

The collimated beam is split using three partial reflectors 400a to 400c, see FIG. 2. Each partial reflector partially passes the incident light beam and partially reflects the incident light beam. A final high reflecting mirror 410 fully reflects the incident light beam.

The partial reflectors 400a to 400c are selected to reflect the correct amount of light to ensure that the generated light is evenly distributed over the resulting four beams . The reflectors are actively aligned, such that each reflector is disposed at a different angle of incident to the generated light beam, to create a precise overlap of all four beams, and to ensure that the resulting illumination field produces a substantially planar field which is substantially parallel to the plane of the display surface .

Each of the four beams is diffused using custom one- dimensional engineered diffusers 500a to SOOd. The diffusers are also actively aligned to ensure overlap of the beams over their entire width.

In the preferred embodiment, the resulting illumination field 800 generated by display controller 200 consists of substantially collinear visible and non-visible light illumination fields 820a and 820b as illustrated in FIG.5a. FIG. 5b and FIG. 5c illustrates how the visible light illumination field 820b can provide a visible indication of the parallelism of the illumination field with respect to a display surface 12 of an interactive device 1000. In this example the interactive device could be a whiteboard or any other suitable surface. In FIG . 5b and FIG. 5c, illuminated area 1500 indicates the portion of the display surface 12 illuminated by the illumination fields 820a and 820b, whilst non-illuminated area 1502 indicates the area of the display surface 12 that is not illuminated by the illumination fields 820a and 820b . As illustrated in FIG. 5b and FIG. 5c, boundary line 1504 indicates the visible boundary between the illuminated and non-illuminated . The position of boundary line 1504 can be changed by making adjustments of the display controller 200 around the X-axis 1200, Y-axis 1201 and Z-axis 1202 of the display controller by any suitable methods, such as a screw mechanism. As adjustments of the display control ler 200 are made around the X-axis, Y-axis and Z-axis, the position of the coilinear visible and non-visible light illumination fields 820a and 820b either moves towards or away from the display surface . The physical position of the coilinear illumination field can be checked by the use of any suitable surface on which visible light is visible, such as a piece of white card. In this way, the alignment of the illumination field can be adjusted without the need of special adj ustment tools that detect non-visible light . On completion of the alignment of the illumination field the visible light generator can be switched off.

Any method or process described herein may be implemented as a computer controlled method or process. Any method or process may be a computer program comprising computer program code which, when operated on a computer system, carries out the defined method or process. A computer program product, such as a computer storage device , such as a computer memory, may store computer program code for carrying out any method or process described here . A computer program product may be a computer memory,, may be other storage device associated with a computer, or may be a stand-alone storage device associated with a computer such a memory disk or memory stick, such as that provided by a USB memory stick.

The invention has been described herein with reference to particular examples associated with interactive systems, and with reference to a particular exemplary interactive system. The invention is not limited to any described example or arrangement, and the scope of protection is defined by the appended claims .

Claims

1. A display controller comprising : a light source for generating at least two light beams of different wavelengths and different angular offsets; a reflective device to receive the different wavelength beams having different angular offsets and to emit the different wavelength beams substantially coincidental and at a substantially common angle ; a reflector array for receiving the different wavelength beams from the reflective device and for generating at least two substantially collinear illumination fields corresponding to the at least two different wavelengths .

2. The display controller of claim 1 wherein the light source generates visible and non-visible light .

3. The display controller of claims 1 and 2 wherein the light source consists of an independent visible light generator and an independent non-visible light generator .

4. The display controller of claims 1 and 2 wherein the light source is a single integrated light source incorporating visible and non-visible light generators.

5. The display controller of claims 3 and 4 wherein the light source is selectively switchable .

6. The display controller of claim 5 wherein the visible and non-visible light generators work independently.

7. The display controller of any of the proceeding claims wherein the light source generates a collimated beam.

8. The display controller of any one of claims 1 to 7 wherein the light source is chosen from one of a laser, light- emitting electrochemical cell or light-emitting diode.

9. The display controller of any of the preceding claims wherein the reflective device is a mirror having nonparallel dichroic surfaces .

10. The display controller of claim 9 wherein the reflective device is rotatably adjustable to adjust the angular offset of the different wavelength beams.

11. The display controller of claim 10 wherein the angle of incident with respect to the light source of at least one of the dichroic surfaces of the reflective device changes when the reflective device is rotatably adjusted.

12. The display controller of one of claims 1 to claim 11 wherein the reflective device further includes a collimating lens for receiving the different wavelength beams from the reflective device and for providing its output as an input to the reflective array.

13. The display controller of one of claim 1 to claim 12 wherein the reflector array consists of a reflector assembly and a diffuser assembly.

14. The display controller of claim 13 wherein the reflector assembly of the reflector array is a combination of one or more partial reflectors and a reflector for creating illumination fields .

15. The display controller of claim 14 wherein the one or more partial reflectors and reflector of the reflector assembly of the reflector array are disposed at different angles of incident to the light beam.

16. The display controller of claim 13 wherein the diffuser assembly of the reflector array consists of a plurality of diffusers for diffusing the reflected light from the reflectors, wherein the number of diffusers is equal to the number of reflectors in the reflector assembly of the reflector array .

17. A method, for an interactive system including a display region, the system being arranged to detect the position of a contact point on the display region, the system including a display controller, the method comprising: a . Generating a visible light illumination field across the display surface of the interactive display system; b . Adjusting the position of the display controller so that the visible light does not intersect the display surface and is planar to the display region; c . Generating a non-visible light illumination field across the display surface of the interactive display system; d. Detecting the position of a contact on the display region using the non-visible light illumination field .