GB2342466A

GB2342466A - Light projector

Info

Publication number: GB2342466A
Application number: GB9921931A
Authority: GB
Inventors: Gary Stuart Morris
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-09-18
Filing date: 1999-09-17
Publication date: 2000-04-12
Also published as: GB9921931D0; GB9820223D0

Abstract

A light projector 2 comprises a housing 8 and a laser 16 mounted within the housing. The housing is mounted on a housing movement device, such as a gimbal arrangement 12 on a fixing base 6 which allows rotation and tilting of the housing 8. A scanning device 20 is connected to a scanner control device 22, and effects movement of a light beam produced by the laser in order to form patterns on a surface, such as a building. The control device 22 is connected to a signal decoder and microprocessor 24, and a switch mode power supply 18 is connected to the laser 16, the scanning devices 20, 22 and the microprocessor 24. A mirror 19, diffraction wheel 33, colour selection device 35 and shutter/beam modulation device 34 are also provided. A remote control device 4 is used to communicate control signals to the laser 16, the scanning device 20, 22 and the housing movement device 12. The light projector may be one of a number of projectors combined to form a system controlled from a single such remote control device which is preferably configured to conform to a standardised protocol, such as DMX protocol.

Description

LIGHT PROJECTOR This invention relates to a light projector of the kind used to produce light displays in advertising, discothèques, clubs, etc.

Known light projectors typically comprise a lamp disposed behind a stencil and colour filter in a movable housing or a fixed housing with a movable mirror. The light from the lamp is directed past the stencil through the filter to project an image or pattern on to a surface such as a wall and the image is moved around the surface by moving the housing or the mirror.

The colour is changed by moving the filter. Each image requires a change of stencil. The selection of this stencil and the movement of the housing or mirror and other parameters such as light intensity and colour, etc. are controlled remotely by connection to a control desk which provides control signals using a standardised protocol (DMX). Multiple projectors may be used with the same control desk.

Lasers offer an alternative light source, having the advantage that a large selection of patterns or images can be achieved by scanning movements of the laser beam rather than using changeable stencils.

Hitherto, lasers have been incorporated into standard projection systems by using an external laser connected to a standard housing by fibre optic cable. The image or pattern to be projected is generated by controlled movements of a mirror under the control of a dedicated laser controller.

However, such a system is very expensive to produce and a significant amount of skill or technical knowledge is required for the operation of the laser controller.

It is an object of the present invention to provide a light-projector with a laser which is of simple and convenient construction and can be readily adapted for operation alongside conventional lamp projectors using standard control techniques.

According to the present invention therefore there is provided a light projector comprising a housing, a laser within the housing, a housing movement device for positional adjustment of the housing thereby to effect positional adjustment of the laser, a scanning device for movement of a light beam produced by the laser to form patterns on a surface, and an interface for communication of control signals from an external remote control device to the laser, the scanning device, and the housing movement device.

This arrangement provides a projector which is of simple, convenient construction, having an integral laser, and may be readily adapted for use with standardised control techniques alongside other conventional lamp- projectors.

The light projector of the invention may have wide application, including use in advertising, e. g. outdoor use for projection on to billboards, buildings, use in musical performances, firework displays, open air events etc.

The projector may be a conventional housing adapted to incorporate the laser. Alternatively, the housing may be designed specifically to incorporate a laser and any associated components, circuitry etc.

The housing may comprise a hollow metal box, alternatively it may comprise a hollow moulded plastic box with a metal subframe.

The housing may be positionally adjustable in any suitable way, the housing movement device allowing rotational or translational movement of the housing in any desired direction along or about a fixed or moving axis or axes.

The housing movement device may allow rotation of the housing about one axis or two or three mutually perpendicular axes.

Preferably, the housing movement device comprises a gimbal arrangement by which means the housing may rotate.

In a preferred embodiment, the gimbal effects positional adjustment of the housing corresponding to conventional positional adjustment ie, 'pan','tilt'and'roll'where'pan','tilt'and'roll'correspond to rotation of the housing about respective axes, which may intersect and may be mutually perpendicular.

The housing movement device may include a fixing portion for mounting the projector on a structure or device.

The housing may be positionally adjustably manually or, alternatively or additionally, positional adjustment of the housing may be power assisted.

Accordingly the housing movement device may incorporate power means of any suitable type, for example, an electric motor which may be a stepper motor, which may be incorporated in any gimbal arrangement.

The scanning device may effect movement of the laser beam in any suitable way for example it may incorporate beam reflection devices such as mirrors.

One or more characteristics of the laser beam may be adjustable, for example, light intensity which may be controlled by adjusting the power of the laser beam, and also image size, diffraction etc.

Conventional lamp-type projectors are controlled by control signals (from the external remote control device) which conform to a standardised, e. g. DMX protocol.

Advantageously therefore, the interface is preferably configured to communicate control signals which conform to a standardised DMX protocol.

The above arrangement allows the light projector to be controlled using standardised control techniques.

Each part or of the DMX signal may control a specific and separate function of the projector. Preferably, the external control device is configured to provide a separate signal channel for each part of the signal (ie function).

Preferably the channel allocations may be altered or be programmable to enable different combinations and configurations of channels. This arrangement would enable the laser projector to mimic different types of lighting projectors by providing functional compatibility between different types of projector.

The light projector may be one of a plurality of projectors combined to form a light projection system controlled from a single remote control device. The other projectors of such a multiple-projector system may be laser and/or lamp-type projectors.

Accordingly, in a further aspect the invention provides a light projection system comprising a plurality of projectors at least one of which is a light projector according to the first aspect of the invention, the system being controlled from a single remote control device.

Low-cost DMX-protocol controllers and lamp-type projectors are available and these use a reduced number of controls and associated signal channels. Many operate on the basis of only four signal channels.

Accordingly, the system may be configured so that the or each light projector may be controlled using four signal channels. In this embodiment the projector may have four functions, corresponding to the four signal channels (or five or mole functions: two functions may share one channel) controlled by the external control device. The light projector housing may be manually position adjustable and may have 360 rotation using one axis of rotation. Alternatively it may even be fixed (without a gimbal arrangement) as opposed to its movement being controlled by the external control device. In the case where the housing is fixed the laser scanning device may be utilised to provide'pan and'tilt'control of the laser beam.

This would provide a low-cost projector compatible with budget DMX controllers and light projectors and which is also very simple to operate.

It is also envisaged that a more advanced form of system may be provided.

Therefore, in a separate embodiment, the system is configured so that the or each light projector may be controlled using eight or more channels. This may allow individual control of eight or more functions of the or each projector, by the remote control device, and may allow for remote control of the positional adjustment of the or each respective housing. This would allow for additional features and greater control than the above low-cost projector.

DMX is a serial protocol and where a plurality of projectors are controlled by a single external remote control device, the projectors are normally connected in series by a single cable to the control device.

Consequently the control signals for all the projectors are communicated in the cable in a series, the signals for each projector being identified by for example, an'address'code.

Preferably, the interface of the or each light projector of the system is operable to direct the appropriate control signal (s), (which may be coded or'addressed', etc to identify the projector), to the laser, scanning device and housing movement device and any additional devices which may each be connected individually ie. in parallel to the interface.

Preferably, the external remote control device (which may be 'external'of the projectors but integral to the system) has a plurality of controls e. g. buttons, switches, fader switches to enable a user to control the or each projector and its components.

The external remote control device may be configured and the DMX coding arranged so that the controls correspond with respective controls for adjustment of identical or similar functions of a conventional lamp projector.

For example, a laser power control for a laser projector may correspond with a lamp intensity control for a lamp projector both operative to control the intensity of the light projected.

With this arrangement a laser projector may be conveniently incorporated into scenes with other conventional (lamp) lighting projectors and/or more lasers projectors.

Preferably the external remote control device forms a part of a control system which incorporates data storage and retrieval facilities so that selected characteristics of the laser beam, images, patterns, scenes and sequences, etc. may be stored and consequently retrieved.

The control system may incorporate or be incorporated to a computer which may be operable to digitise images (and store/retrieve stored images) which may then be communicated to the interface by signals which may conform to a standardised e. g. DMX protocol. This would allow for computer generated images e. g. custom logos, new pictures, to be projected by the laser beam and software operating system updates to be utilised, etc.

Although, the invention can be used to utilise lasers without using an external laser device, where appropriate, the system may also be configured to incorporate an external laser device which may be connected by fibre optic cable to the laser projector. The external laser device may be controlled using the external remote control device.

Thus a large, high powered laser system could be utilised if so desired. The benefit here is that the laser projector would be controllable using standard e. g. DMX control techniques.

The invention will now be described by way of example onty and with reference to the accompanying drawings in which: Fig. 1 is a diagrammatic representation of a light projector according to one form of the present invention, and Fig. 2 is a diagrammatic representation of a light projector according to another form of the present invention.

Referring to figure 1, the light projection system 1 comprises a plurality of projectors (only one shown) mounted at various locations internally and externally of a building (not shown). The projector 2 shown is mounted on overhead scaffolding inside the building. (The projector may alternatively be mounted on the ceiling, wall, roof, lighting rig or any means available). The projectors are all connected in series by cable 3a and 3b (for transmission of signals to and from the projectors) to a desk mounted remote control device 4. Cable 3b is fed to the other projectors in the system 1. Each projector is controlled individually from the desk. The projectors are operable to project light images on the internal and external surfaces of the building. The externally mounted projectors (not shown) are also operable to project images in to the open air, surrounding buildings, etc.

The projector 2 is a laser projector having a movable housing 8 mounted by a housing movement device comprising a gimbal arrangement 12 on a fixing base 6.

The remaining projectors (not shown) are lamp (ie. halogen bulb) and laser type projectors.

The housing 8 of the projector 2 comprises a hollow rectangular metal box having a aperture 9, on side 8a. Alternatively, the housing may be a plastic moulding with a metal subframe.

Housed within the housing 8 is a laser 16 having a light beam output point 16a.

The housing 8 also houses a scanning device 20 for movement of a light beam to form patterns on the surfaces of the building and which is connected to a scanner control device 22. This is in turn connected to a signal decoder and micro-processor system 24. A switch mode power supply unit (PSU) 18 is connected to the laser 16, the signal decoder and micro-processor 24 and both scanner components 20,22. A mirror 19 is located in the housing adjacent the aperture 9 and aligned with the laser beam 30 of the laser 16 and scanning device 20.

A diffraction wheel 33 is located between the scanner component 20 and the aperture 9 and is connected to the signal decoder 24. A colour selection device 35 and shutter/beam modulation device 34 are located at spaced apart positions between the mirror 19 and the beam output point 16a, and are connected to the signal decoder 24.

The fixing base 6 of the projector 2 comprises a hollow metal body housing a motor (not shown) and incorporating integral clamps (not shown) with which the base is fixed to the scaffolding.

The gimbal arrangement 12 comprises a pivotable U-shaped ring 26.

Opposing sides 8b and 8c of the main body are pivotally attached to respective ends of the U-shaped ring 26 which engage respective drive shafts of motors located in the housing 8. This ring arrangement is constructed to allow the rotation or tilting of the housing 8 relative to the ring about a tilt axis T-T, and the rotation is restricted to be within a range of 270 .

The U-shaped ring 26 is pivotally mounted on the fixing base by a pivot member 28 extending from its mid-point to engage a drive shaft of the base motor. This allows motor driven rotation of the ring 26 relative to the base 6 (to effect'panning'of the projector) about a'pan'axis P-P (which is perpendicular to axis T-T). The ring is able to rotate in 360 .

The desk mounted control device 4 is of the conventional type used to operate standard lamp-type lighting projectors and which has user operable controls to control separately the functions (or characteristics) of each projector. Control signals are communicated from the control device 4 to the projectors using DMX protocol. Signals for each projector communicated via the cable 3a from the control unit. DMX code specific to each projector is routed to the relevant projector using identification code in the signal.

The signal specific to the laser projector is then decoded by the signal decoder which generals the relevant control signals for the scanner control device 22, the diffraction wheel 33, the shutter/beam modulation device 34, the colour selection device 35, and the laser 16.

The signal coding is arranged so that the functions of the laser projector correspond closely to those of a lamp-type projector as follows, each corresponding function using corresponding channels of the control device.

CHANNEL NUMBER LAMP FUNCTION LASER FUNCTION 0 shutter/strobe shutter/strobe reset/lamp on/off reset/laser on/off 1 Lamp intensity Laser Power 2 Lamp colour 1 Laser colour 1 3 Colour 2 Colour 2 4 Rotating Gobo selection image bank number 5 Rotating Gobo Index Image number in selected bank 6 Fixed Gobo modulation eftects 7 Focus aux. feature 8 Iris image size 9 Prism Diffraction effects 10 Pan (pan coarse) PAN position 11 Pan (pan fine) X scanner position 12 Tilt coarse TILT position 13 Tilt fine Y scanner position 14 Speed pan/tilt Speed pan/tilt 15 Dimmer/iris/focus gobo indexing Power/sizing/image indexing This arrangement means that all the projectors 2 of the system 1 may be controlled from the same control desk 4 using standard (DMX) control techniques despite there being a combination of laser and lamp type projectors in the system 1. Of course it will be apparent to those skilled in the art that other channel/function configurations may be possible.

Thus each part (ie channel) of the DMX signal controls a separate function of the projector.

Positional adjustment of the projector's housing 8 is controlled by the 'PAN position'and'TILT position''and'speed of pan/tilt'settings (channels 10,12 and 14 respectively) connected to PAN and TILT controls on the desk. Again, it will be apparent to those skilled in the art that a different channel/function configuration may be used to effect control of positional adjustment of the housing.

The'Gobo'functions of the lamp projector correspond with'image bank'functions of the laser projector both being for selection of an image to be projected.

The DMX control signal inclues x, y co-ordinates of the image (where x and y are Cartesian Co-ordinates plotted with reference to linear, mutually perpendicular and intersecting axes X and Y) which control the position of the scanner and thereby control the direction of the projected light beam.

In use, the projector 2 is controlled from the control desk 4 by a operator using the controls which correspond to the projector functions as indicated above.

The laser is switched on and the laser 16 emits a beam 30 from the laser output point 16a. The beam is then reflected by a mirror 19, into the scanning device 20.

The operator selects the image 31 to be projected from a selection stored in image banks in the microprocessor unit 24 (by the control unit 4).

This generates the x, y co-ordinates (corresponding to the selected image) which are fed to the scanner controller 22. The scanner controller 22 controls the scanner 20 which moves the light beam (according to x, y co-ordinates) to project the two dimensional image 31.

The image 31 is then modified by modifying the properties of the beam 30. The beam 30 is modified in colour, light density etc using appropriate controls on the control unit 4 to control the diffraction wheel 33, colour selection device 34 and shutter/beam modulation device 35.

The beam exits the housing 8 via the aperture 9 on the side 8a and the image 31 is projected onto the interior surfaces of the building. (Of course, depending on where the projector is mounted, it may be operable to project light images on any e. g. external surfaces of the building and the open air etc).

The image 31 is moved around the surface by positional adjustment of the housing 8 and this is controlled using the PAN and TILT controls which control rotation of the body about respective pan P-P and tilt T-T axis in the usual way.

Referring to figure 2, the light projection system 100 is as described above except that this embodiment comprises a gimbal arrangement 112 which allows for rotation of the housing about three mutually perpendicular and intersecting axes P (pan), T (tilt) and R (roll).

The gimbal arrangement 112 comprises two pivotable brackets or rings 126 and 127.

Opposing sides 108a and 108c of the housing 108 are each pivotally attached to respective midpoints of opposing sides of the square bracket 127 via respective pivot members 127a and 127b. Respective motors located in the body 108 (or alternatively in the bracket 127) are operative to drive rotation of the body 108 relative to the bracket 127.

Respective ends of the U-shaped bracket 126 are pivotally connected at respective midpoints of opposing sides of the bracket 127 at junctions 126a and 126b. Respective motors located in the junctions 126a and 126b are operative to drive rotation of the bracket 127 relative to bracket 126.

This gimbal arrangement 112 is constructed to allow rotation of the housing 108 relative to the base 106 about three intersecting and mutually perpendicular axes: P, T and R.

Rotation about axis T is restricted to be within a range of 270 ; and rotation about axis R is restricted to be within a range of 180 . Rotation about axis P is restricted to be within a range of 360 .

The signal coding in this embodiment is arranged as follows : CHANNEL NUMBER LAMP FUNCTION LASER FUNCTION Lamp Intensity Laser Power 2 Lamp colour 1 Laser colour 1 3 Colour 2 Colour 2 4 Rotating Gobo selection Image bank number 5 Rotating Gobo Index Image number in selected bank 6 Fixed Gobo modulation effects 7 Focus aux. feature 8 Iris Image size 9 Prism Diffraction effects 10 Pan (pan coarse) PAN position 11 Pan (pan fine) X scanner position 12 Tilt coarse TILT position 13 Tilt fine Y scanner position 14 ROLL ROLL POSITION 15 Speed pan/tilt Speed pan/tilt 16 Dimmer/iris/focus gobo indexing Power/sizinglimage indexing In use, the projector is controlled as described for the above embodiment except in that positional adjustment of the projector housing 108 is controlled by'PAN position', TILT position'and ROLL position' together with the speed control (channe 15).

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiments which are described by way of example only.

Claims

CLAIMS 1. A light projector comprising a housing, a laser within the housing, a housing movement device for positional adjustment of the housing thereby to effect positional adjustment of the laser, a scanning device for movement of a light beam produced by the laser to form patterns on a surface, and an interface for communication of control signals from an external remote control device to the laser, the scanning device, and the housing movement device.
2. A light projector according to claim 1 in which the housing movement device allows rotational or translational movement of the housing along or about a fixed or moving axis.
3. A light projector according to claim 1 or claim 2 in which the housing movement device allows rotation of the housing about one axis.
4. A light projector according to claim 1 or claim 3, in which the housing movement device allows rotation of the housing about two or three mutually perpendicular axes.
5. A light projector according to any preceding claim, in which the housing movement device comprises a gimbal arrangement by which means the housing may rotate.
6. A light projector according to any preceding claim in which the interface is configured to communicate signals which conform to a standardised DMX protocol.
7. A light projector according to claim 6 in which each part of the DMX signal controls a function of the projector.
8. A light projection system comprising a plurality of projectors, at least one of the said projectors being a light projector according to any preceding claim, and the system being controiled from a single remote control device.
9. A light projector system according to claim 8 in which the or each light projector has four functions which are controlled by the external control device using four corresponding signal channels.
10. A light projector according to claim 8 in which the or each light projector has five or more functions which are controlled by the external control device using four signal channels wherein two functions share one signal channe.
11. A light projector system according to claim 8 in which the or each light projector has eight or more functions controlled by the remote control device, using eight or more signal channels.
12. A light projector system according to claim 11 in which positional adjustment of the or each respective housing is remotely controlled by the said remote control device.
13. A light projection system according to any of claims 8 to 10 in which the external remote control device has a plurality of controls to enable a user to control the projector and its components.
14. A light projection system according to any of claims 8 to 13 in which the external remote control device forms part of a control system which incorporates data storage and retrieval facilities so that selected characteristics of the laser beam may be stored and consequently retrieved.
15. A light projection system according to claim 14 in which the control system is connected to a computer which is operable to digitise images, and store/retrieve stored images which are communicated to the interface by signals.
16. A light projection system according to claim 15 in which said signals conform to a standardised, e. g. DMX, protocol.
17. A light projector substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
18. A light projector systems substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.