GB2249164A - An illumination lamp apparatus - Google Patents

Abstract

The apparatus comprises a conventional lamp for providing lighting effects at concerts or shows and the like to which a laser scanning device 100 has been added. Safely cut-out devices operated by cams and switches are provided in order to ensure that the laser is not pointed at the audience or performers. <IMAGE>

Description

AN ILLUMINATION LAMP APPARATUS The present invention relates to an illumination lamp apparatus of the type for producing a beam of light so that various illumination effects can be achieved.

It is quite common practice in popular music concerts, TV shows, films, and the like to have an elaborate illumination display to enhance the effects of the music. These are produced by illumination lamp apparatus which have to be controlled to give the desired effect. Most known apparatus are fairly cumbersome and are usually mounted on an elaborate gantry and each has to be individually controlled from a central console via a remote link between the console and the individual lamp apparatus.

A more compact apparatus is described in European Patent Application No EP-A-0,260,895 of the present Applicants which is described below with reference to Figure 1. The apparatus shown in Figure 1 is normally mounted in a cradle allowing pivoting about both a vertical axis and a horizontal axis.

Such a cradle is of a well known type.

The apparatus 1 itself comprises a frame formed by three fibreglass support boards 10, 11, 12 these being spaced apart from one another by metal spacers 14 with associated securing bolts 16. One or more of the support boards 10, 11, 12 may carry printed circuit elements (not shown) of a conventional nature.

Mounted rearwardly of the support board 10, is a rear subframe 22 carrying a source of illumination provided with a beam producing reflector (not shown) adapted to project a beam of light along the main axis of the apparatus. The source and reflector are purely conventional and can be removably mounted in the sub-frame 22 for ready replacement.

The sub-frame 22 also carries, on spaced pivots openable and closable shutters operable by two solenoids which are intended to enable the beam of light to be blocked.

Mounted in front of the forward support board 12 is a front sub-frame 32 having four forwardly extending guide rods 34 parallel to the main axis of the apparatus. These carry a conventional lens assembly 36 which can be moved back and forth a short distance. The lens assembly may include a simple lens or may include several lenses, at least one of which may be individually adjustable relative to one another to alter the focal length of the assembly.

Mounted between the support boards 11, 12 is firstly, and near to the circuit board 12, an iris 40 which can be opened and shut by a lever 42 mounted on a ring gear 43 which in turn is mounted on pinions 45 one of which can be seen in Figure 1. Mounted rearwardly of the iris 40 is a gobo disk 44 which is spaced from the plane of the iris itself by a given distance, for example, 7 millimetres.

Positioned forwardly of the gobo disk are four colour disks 46, 48, 50, 51. The gobo disk 44 is provided, at circumferentially spaced locations, with several apertures.

The first aperture is a purely circular aperture of approximately the same size as the fully opened iris 40. The remaining apertures are provided with different shaped holes, cut-outs and slots. Each colour disk 46, 48, 50, 51 is provided with six circumferentially spaced openings into which can be positioned coloured or interference filters, these being retained in place by spring clips (now shown).

The gobo disk can be formed in the same way, to enable slides with different aperture configurations to be substituted to give a desired effect.

It is an aim of the present invention to provide an illumination lamp apparatus which is capable of additional effects.

According to the present invention there is provided an illumination lamp apparatus comprising a laser light source for generating a laser beam; a scanning means for scanning said laser beam in desired patterns; and support means for supporting said scanning means, said support means including rotation means for changing the orientation of said scanning means about at least one axis.

The present invention will be further described with reference to the following description of an exemplary embodiment and the accompanying drawings, in which: Fig 1 is a partially cut-away perspective view of a prior art lamp; Fig 2 is a partially cut-away perspective view of an embodiment of the present invention; Fig 3 is a perspective view of a base and cradle of an embodiment of the present invention; Figs 4 and 5 are expanded views of parts of the base of Fig 3; Figs 6 and 7 are side views of a tilt mechanism of the present invention; and Figs 8 and 9 show a shutter mechanism used in embodiments of the present invention.

Figure 2 shows an embodiment of the illumination lamp apparatus according to the present invention. The apparatus 2 basically comprises a lamp apparatus as described hereinbefore with reference to Figure 1 to which a laser scanning head 100 has been added. The known part of the apparatus functions as has been described to produce a wide variety of illumination effects while the laser scanning head, which will be described in more detail below, produces further effects which overlie and fill in the effects produced by the colour and gobo disk combinations.

The laser light for the laser scanning head is generated remotely from the scanning head by a conventional laser 101 and piped to the scanning head via an optical fibre 102. The laser beam passes through a shutter mechanism 104 which can block the beam. The beam is then passed to an arrangement of moving mirrors (X and Y axis) 110 which can be controlled to scan the beam as desired. The beam then passes through two effects mechanisms 106, 108 which can introduce various diffraction effects such as linear diffraction or spectral (starburst) diffraction.

The apparatus is further provided with safety switches linked to the shutter mechanism 104 and an additional shutter mechanism 105 at the laser source to cut of the laser beam when it points in certain selectable directions. This is most advantageously achieved by providing an arrangement of cam operated switches on the pan and tilt mechanisms of the lamp which can be set to cut the laser beam if the lamp points in certain selectable directions. It is advantageous to block the beam at both the scanning head and the source to provide extra safety protection.

Figures 3, 4 and 5 show the base 120 which incorporates the pan mechanism and on which the lamp 2 is mounted. The lamp 2 is supported by the cradle 122 and tilt mechanism (Figure 6).

The cradle 122 is rotated by the pan mechanism under the control of the operator. Two cams 124a,b are attached to the cradle 122, these are generally circular save for a stepped portion 130 of increased radius, shown in Figure 4, which occupies approximately 120 of arc. Two microswitches 132, 134 are mounted on the base 120 in such a position that they are closed by the step portion 130 when it is opposite them.

The switches are connected in series to the shutter mechanism 104 and the additional shutter mechanism 105 so that all switches 132, 134, 140 a and b must be closed before the shutter mechanisms are opened. Therefore if any of the switches should fail or break, the beam will be blocked.

Also in the event of a power failure the shutter mechanisms will block the beam. A roller 133, bearing on both cams, may be provided between the microswitches and the cams to avoid wear to the switches. As is shown in Figure 5 the two cams 124a,b are held in place by two members 136a,b which are clamped together by a bolt 128. Releasing the bolt 128 allows the cams to be rotated independently relative to the cradle 12. This enables the operator to preset a range of between 120 and 240 or two ranges of 1200, at any position relative to the cradle 122, over which the beam will be blocked.It has been found that for most purposes two cams with 120 beam cut out portions is convenient, however if other or additional ranges are desired additional or custom built cams can be added or used in place of the standard ones.

Figures 6 and 7 show the arrangement of cams connected to the tilt mechanism. The lamp 2 is supported by the cradle 122 such that it can be rotated by a tilt mechanism 137.

Similarly to the pan mechanism, two cams 138a,b are attached to the lamp 2 and two switches 140a,b are mounted on the cradle 122 so that they are closed by the stepped portion of the cams. As before the cams can be released and independently rotated relative to the lamp in order to set the portion over which the beam is to be cut. If the two sets of switches are arranged in series then only one of each must be open to block the beam, i.e. the beam is cut off if it is pointing in either a prohibited declination and a prohibited bearing or both.

Figures 8 and 9 show the shutter mechanism 104. The optical fibre ends at port 142 from which the laser beam 144 issues.

The beam 144 then reflects off mirror 146 and passes onto the rest of the scanning head unless it is blocked by plate 148.

Plate 148 is mounted on lever 150 which pivots about pivot 152 under the control of arm 154. Arm 154 may be driven by a servo motor or a solenoid, for example. Figure 9 shows the arrangement of Figure 8 in place. As can be seen the beam will pass unhindered when the plate and lever are in the dashed configuration. The plate 148 is painted black to absorb the beam. The additional shutter mechanism 105 may be of a similar construction.

When, as is usual, the lamp is controlled by computerised control apparatus it would be possible to build in software to monitor the direction of the beam and cut it when it points in prohibited directions, however the use of cams and switches attached directly to the pan and tilt mechanisms guards additionally against the possibility of mechanical failure of the drive mechanisms.

While the present invention has been described with reference to a particular type of non-coherent lamp apparatus it is to be appreciated that the above described laser scanning head may be combined with any suitable lamp.

Claims (9)

1. An illumination lamp apparatus comprising: a laser light source for generating a laser beam; a scanning means for scanning said laser beam in desired patterns; and support means for supporting said scanning means, said support means including rotation means for changing the orientation of said scanning means about at least one axis.

2. An apparatus according to claim 1, further comprising a non coherent beam producing apparatus mounted on said support means in such a manner that the non coherent beam producing apparatus is rotated by said rotation means together with said scanning means.

3. An apparatus according to claim 1 or 2, further comprising beam cut-off means for cutting off said laser beam when said scanning means is pointing in at least one predetermined range of directions.

4. An apparatus according to claim 3, wherein said beam cut-off means comprises a shutter mechanism for blocking said laser beam.

5. An apparatus according to claim 3 or 4, wherein said cut-off means comprises at least one cam member mounted on said support means so as to rotate in synchronism with said scanning means and at least one switch arranged to be closed by the or each cam member at selected positions of said scanning means.

6. An apparatus according to claim 5, wherein said cutoff means comprises a plurality of cam members each having at least one portion of increased radius adapted to operate said at least one switch.

7. An apparatus according to claim 5 or 6, wherein the rotational position of the or each cam member relative to said scanning means is adjustable.

8. An apparatus according to any one of claims 1 to 7, wherein said rotation means comprises first and second rotation means for rotating said scanning means about first and second orthogonal directions.

9. An illumination lamp apparatus constructed and arranged to operate substantially as hereinbefore described with reference to, and as illustrated in, Figures 2 to 9 of the accompanying drawings.