WO2017029528A1

WO2017029528A1 - Framing-light projection

Info

Publication number: WO2017029528A1
Application number: PCT/GB2016/052604
Authority: WO
Inventors: Keith Allen SANETT; Jonathan Richard COLES
Original assignee: Light Chemistry Ltd
Priority date: 2015-08-20
Filing date: 2016-08-22
Publication date: 2017-02-23
Also published as: GB201514865D0; GB2558432A; GB201802684D0

Abstract

In methods and apparatus for framing-light projection onto a painting or other target, light from an array (1) of light- emitting diodes (LEDs) is reflected differentially by a micro- mirror array within a projection unit (4) to shape the cross- section of the projected light-beam. The shaping is under the control of an image-processing control unit (3) in accordance with a digitally-defined boundary in the form of a computer graphic of closed two-dimensional outline stored in a data storage unit (7). An image of the target from a digital camera (21) can be analysed in conjunction with a stored library of shapes to derive a digitally-defined framing- boundary for indication or motorised adjustment of the orientation/ setting of the projection unit (4) required for this framing. A light sensor 24 may be used with the projection unit (4) to maintain the lighting level of the target within a predetermined limit.

Description

Framing-Light Projection

This invention relates to methods of framing-light projection, and framing-light projection apparatus using the method.

Methods of framing-light projection, namely where there is shaping of the illuminated area of a target onto which a beam of light is projected, are well-known in the context of the illumination of artworks and architectural features. They commonly use physical masks or paddles to provide the shaping of the projected beam of light necessary for the desired framing illumination in the area of the target. The

configuration of physical masks and/or paddles required in any particular circumstance, and the positioning and orientation of them in order to achieve the desired result, is normally difficult, especially in the common situation in which the projected light beam is incident on the target at an acute angle.

The illuminated area in the framing of an artwork or other target may overlap the area of the target itself, and in the case of a painting for example, may extend just to the edge of the painting, to the outer edge of its frame, or by a certain amount beyond that .

It is one of the objects of the present invention to provide a method of framing-light projection, and framing-light

projection apparatus, by which the need for physical masks and/or paddles can be overcome, and the burden of the task made easier.

According to one aspect of the present invention there is provided a method of framing-light projection onto a target wherein signals in accordance with a digitally-defined boundary are supplied to a projection unit to shape a beam of light projected from the unit onto the target, and the configuration of the boundary is selectively adjustable to bring about a desired framing of the target by the projected beam of light.

According to another aspect of the present invention there is provided apparatus for framing-light projection onto a target, the apparatus comprising a unit for supplying signals in accordance with a digitally-defined boundary, a light source, and a projection unit for deriving from the light source a beam of light for projection onto the target, the projection unit being responsive to the supplied signals to shape the projected beam of light in accordance with the supplied signals .

The light beam of both the method and apparatus of the present invention may be derived from an array of light-emitting diodes (LEDs), and in this case the LEDs, or only some of them, may be of a kind that is capable of emitting light selectively in different colours according to their

energisation . The projection unit of both the method and apparatus may incorporate a mirror array that configures light it receives into the beam by differential reflection in accordance with the signals supplied to the projection unit. A method and apparatus for framing-light projection according to both aspects of the present invention, will now be

described, by way of example, with reference to the

accompanying drawings, in which: Figure 1 is a schematic drawing of framing-light projection apparatus according to the present invention;

Figures 2 and 3 are illustrative in side-view of installations of the framing-light apparatus of Figure 1 mounted

respectively from a ceiling and recessed in the ceiling; and

Figure 4 is a schematic drawing illustrating a modification of the apparatus of Figure 1 in accordance with the invention to provide for automatic adjustment, or indication, of

appropriate light framing of a target.

Referring to Figure 1, the framing-light projection apparatus has a light source that is formed by an array 1 of light- emitting diodes (LEDs) that is mounted on a heatsink 2.

Energisation of the LEDs of the array 1 is controlled from a unit 3 for providing the functions of image processing and control of the apparatus. The array 1 may, for example, be composed of LEDs that all emit white light, but it is

preferred to use LEDs of a kind that is capable selectively (according to width of pulse used for energisation) , to emit cool-white light (5000 K) or warm-white light (2600 K) . By energising some of the LEDs of the array 1 from the unit 3 to produce cool-white light and the remainder of the array 1 to produce warm-white light, and by varying the degrees of energisation to adjust the relative intensities of the two colours, it is possible for the light emitted from different areas of the array 1 to differ in colour and intensity from one another.

The light from the array 1, which may for example have a luminous flux in excess of 1,000 lumens, passes into a projection unit 4 via an input lens unit 5. Components of the light entering the unit 4 are reflected differentially into a beam of light that exits the unit 4 via an output lens unit 6. Reflection of the light in the unit 4 is by a micro-mirror array of microscopically-small mirrors laid out on a

semiconductor chip that uses Digital Light Processing ('DLP') technology to mix and configure the light received from the LED array 1 into a coherent beam that is shaped according to digital data control signals received from the unit 3.

The digital data control signals supplied to the unit 4 from the unit 3 are derived within the unit 3 in accordance with data stored in a data storage unit 7. The data stored in the unit 7 is in accordance with a digitally-defined boundary in the form of a computer graphic of a closed two-dimensional outline previously generated by a computer (not shown) during set-up of the projection installation. The graphics data is entered in the unit 3 for storage in the unit 7 during set-up via a connection that is established through a unit 8 which interfaces with a local-area network or wireless node 9 accessed by the set-up computer. The unit 3 reads out the data stored in the unit 7 and supplies signals in accordance with this data to the unit 4, which, through the response of its micro-mirror array, configures the light projected from it into a beam having a shape (in cross-section) that corresponds to that of the closed two-dimensional boundary outline previously generated by the set-up computer. As projected from the unit 4 via the lens unit 6, this beam provides the required framing

illumination of the target. Initially during the set-up process with the computer accessing the node 9, the set-up computer is operated in a graphics mode to display an image of a closed two-dimensional boundary outline. The data signals in accordance with this shape received by the unit 3 are stored in the unit 7, and when read out and supplied by the unit 3 to the unit 4 cause the light beam projected by the unit 4 to adopt a cross- sectional shape corresponding to the outline displayed by the set-up computer connected to the node 9. The consequential illumination of the target by this beam is observed, and adjustments are made at the computer to the shape of the outline using the standard graphic-toggle techniques to the edge and elsewhere of the graphic display. The adjustments are made while observing in real time the consequential changes to the illumination of the target, and are continued until the illumination of the target by the projected beam is brought accurately to the framing desired. Once the desired framing has been achieved, the data signals from the set-up computer are stored safely in the unit 7 for use in

maintaining the configuration of the projected light beam required to produce the desired framing of the target. The apparatus can then operate in a "run" mode in which it will operate autonomously, and return to the saved beam

configuration each time it is switched on. The intensity of the light framing the target is adjustable via a dimming control unit 10 that is connected to the unit 3 for regulation of the brightness signals supplied to the projection unit 4. Thus, it will be appreciated from the method of the present invention as described above with reference to Figure 1, that the present invention provides a very-direct and easy way of achieving the configuration of light beam required for framing, without the necessity for complicated calculations or design and orientation of physical masks or paddles. The required configuration of light beam is advantageously derived and directly implemented simply from adjustment to the extent necessary of the shape of a closed two-dimensional boundary outline in computer graphics, for achieving and retaining the set-up required for the desired framing of the target. An important factor is that the required projection is set up, and can be readily up-dated, live. The user when observing the projection in setting up and up-dating is seeing the actual, real-world form of the framing, with the effects of any distortion, skew or distance related to the projection being immediately revealed and readily negated.

The mounting of the apparatus of Figure 1 may, for example, be from a ceiling, or recessed in the ceiling. An example of apparatus mounted from a ceiling is illustrated in Figure 2 and will now be described.

Referring to Figure 2, the units 3 and 4 of the apparatus are in this case enclosed together with the optical elements of the units 5 and 6, within a projector 11 that is mounted securely beneath an electrical power-supply unit 12. The unit 12 is mounted on the underside of the ceiling 13 with the projector 11 below it. The projector 11 is inclined

downwardly to project the generated beam towards the target (not shown) .

An example of apparatus recessed into the ceiling is

illustrated in Figure 3.

Referring to Figure 3, the components of the apparatus of Figure 1 are in this case enclosed together within a projector 14. The projector 14 is directed downwardly at an adjustable angle to project the generated beam through a small-diameter opening 15 through the ceiling 16.

The target may be a painting, architectural feature, or other artwork, and if certain areas of the target are to have emphasis in the framing, this can be readily achieved with increased intensity of illumination in those areas. Furthermore, if the target is larger than can be framed with one projector, two or more projectors 14 can be used and the light from them combined overlapping or abutting one another. A facility of the software used can allow for crossfade between overlapping beams of light to fade the intensities or 'feather' the edges that overlap. The projectors with overlapping light are set-up together and the crossfade between them can result in an even light-intensity throughout the framing.

Operation of the apparatus may be automated by the addition of a camera and a logic system that are operative automatically to select or suggest by indication the framing outline appropriate for use. An example of equipment that may be adopted to add this functionality to the apparatus of Figure 1, is illustrated in Figure 4.

Referring to Figure 4, a digital camera 21 is mounted with the projection unit 4 of the framing-light projection apparatus of Figure 1, to include a target T within its field of view F-F . The digital image or photograph of the target T derived by the camera 21 is analysed within a shape-recognition module 22 in conjunction with a stored library of shapes, to establish within a processor 23 a digitally-defined boundary of the target T. The boundary establishes an effective computer- graphics mask for confining the projected beam of light from the projection unit 4 to the appropriate shape for framing the target T. This mask may be used in the processor 23 to adjust the projection unit 4 automatically to an appropriate

orientation (for example on a motorised mounting that is adjustable independently in each of three mutually-orthogonal axes) and/or setting to achieve this framing, and/or to give an indication, graphically or otherwise, of the adjustment required . A light sensor 24 may be included with the apparatus of Figure 4 to sense the level of light incident on a painting or other target, and in these circumstances the intensity of the relevant framing-light projected onto the target may be regulated in dependence on the sensed level of light to ensure that a prescribed maximum intensity of total light is not exceeded. This feature is particularly advantageous in circumstances where a target painting or other artwork is insured for high value and the insurers require provision for protecting it from exposure to excessive levels of light. For this, for example, the light sensor 24 may be aimed at the location of the target onto which the projected light beam is centred (which may be the centre of the target) for spot metering of the light, and may sample the light level at regular intervals (for example, every few seconds). In the event that the sampled light level exceeds a prescribed level, a processor 25 exerts control via the unit 3 (Figure 1) to correct this by dimming the light level of the beam projected from the projection unit 4.

Claims

Claims :

1. A method of framing-light projection onto a target wherein signals in accordance with a digitally-defined boundary are supplied to a projection unit to shape a beam of light projected from the unit onto the target, and the configuration of the boundary is selectively adjustable to bring about a desired framing of the target by the projected beam of light.

2. A method according to claim 1 wherein the light beam is derived from an array of light-emitting diodes (LEDs) .

3. A method according to claim 2 wherein at least some of the light-emitting diodes are operable to emit light in different colours according to their energisation.

4. A method according to any one of claims 1 to 3 wherein the projected beam of light is shaped by differential

reflection of light in accordar ce with the signals supplied to the projection unit.

5. A method according to claim 4 wherein the differential reflection of light in accordance with the signals supplied to the projection unit includes mixing of components of that light into the beam.

6. A method according to any one of claims 1 to 5 wherein an image of the target derived by digital camera is analysed in conjunction with a stored library of shapes to define digitally from the analysis a light-framing boundary of the target, and wherein the signals supplied to the projection unit are derived from this analysis.

7. A method according to claim 6 wherein adjustment of the projection unit in orientation and/or setting is made or indicated for light-framing of the target in accordance with the framing boundary defined digitally from the analysis .

8. A method according to any one of claims 1 to 7 wherein the light incident on the target is sensed, and the light projected from the projection unit is adjusted to maintain the level of light incident on the target within a predetermined limit .

9. Apparatus for framing-light projection onto a target, the apparatus comprising a unit for supplying signals in accordance with a digitally-defined boundary, a light source, and a projection unit for deriving from the light source a beam of light for projection onto the target, the projection unit being responsive to the supplied signals to shape the beam of light in accordance with the supplied signals .

10. Apparatus according to claim 9 wherein the light source is an array of light-emitting diodes (LEDs) .

11. Apparatus according to claim 10 wherein at least some of the light-emitting diodes are operable to emit light in different colours according to their energisation.

12. Apparatus according to any one of claims 9 to 11 including a micro-mirror array for shaping the projected beam in accordance with the signals supplied to the projection unit by differential reflection of light from the light source.

13. Apparatus according to claim 12 wherein the differential reflection of light according to the signals supplied to the projection unit includes mixing of components of that light into the beam.

14. Apparatus according to any one of claims 9 to 13 including a digital camera to derive an image of the target, and a shape-recognition module to act in conjunction with a stored library of shapes for analysis to define digitally a light-framing boundary of the target, and wherein the signals supplied to the projection unit are derived from this

analysis .

15. Apparatus according to claim 14 wherein the projection unit is adjustable in orientation and/or setting for light- framing of the target in accordance with the light-framing boundary defined digitally from the analysis.

16. Apparatus according to any one of claims 9 to 15 including a light sensor to sense the level of light incident on the target, and the projection unit is operable to adjust the light projected from the projection unit to maintain the level of light incident on the target within a predetermined limit .

17. Apparatus according to any one of claims 9 to 16 including a light sensor, and wherein provision is made for regulating the light projected from the projection unit to maintain the level of light incident on the target within a predetermined limit.