It is known to simulate a flame in an electrical fire by rotating a reflector in front of light bulbs. The reflector interferes with the direct passage of light to simulate a flame effect. Normally the flame effect is driven by ordinary light bulbs and mechanical devices, but the disadvantage is that the flame effect is repetitive, which rapidly reduces the effectiveness of the illusion. Furthermore the mechanical components are liable to wear. It is also known to use a plurality of electrically powered light sources and a controller to control the light sources to cause groups to come on and go off in a sequence to simulate a flame. The light of these light sources is directed towards the viewer or projected onto a screen. This construction has the disadvantage that the flame effect does not look very natural. The construction requires a lot of space in order for the viewer to view the flame and not look directly into the light source.

The present invention provides apparatus for simulating a flame, the apparatus comprising a light source, reflection means for directing the light from the light source towards a viewer, and a viewing means through which a viewer may, in use, view the reflection means.

The reflection means may comprise a reflection member for scattering light. The reflection member may be arranged to reflect light in a pattern which may be a curved or linear pattern. The reflection means preferably comprises at least one multi-facet mirror and/or one wavelength selective mirror and/or at least one prism and/or at least one holographic element. The holographic element may consist of holographic paper.

The light source may comprise a plurality of light elements of different colours. The different colours may include red, yellow, orange and blue. The light elements may consist predominantly of the colours yellow and orange to simulate a wood flame. The light elements may consist predominantly of the colours yellow and red for simulating a coal flame. The colours may include blue when simulating a gas flame. The light elements of a first colour may be arranged in a first arrangement and the light elements of a second colour may be arranged in a second arrangement. The first arrangement may be perpendicular to the second arrangement. The light elements may be arranged in lines, in groups or in an irregular pattern. The light elements are preferably LEDs.

Preferably, the viewing means consist of a diffuser. The diffuser may consist of a screen. The diffuser may be opaque and/or semi-transparent and/or transparent. The diffuser may be substantially vertical to simulate the window of a conventional fire.

The apparatus may also comprise a controller for controlling the light source. The controller may also control the output of the light elements, either individually or in groups.

Preferably the controller is arranged to control the light source to simulate all or part of a life cycle of a flame, from initial kindling to full burning and then dying away to small flames or embers. Preferably the controller is an electronic controller. The controller may be programmable.

The light source may be movably arranged. The viewing means may also be movably arranged. The reflection means are preferably movably arranged.

The controller may control the movement of the light source and the reflection means relative to one another. The controller may also control the movement of the viewing means.

The invention further relates to a fireplace having an apparatus for simulating a flame as described in previous paragraphs.

The invention still further relates to a method of simulating a flame, in which light is produced by a light source as described in any of the previous paragraphs, the light is directed from the light source towards a viewer by reflection means as described in any of the previous paragaphs, and the reflection means are subsequently viewed through viewing means as described in any of the previous paragraphs.

Embodiments of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which:- Fig. 1 shows a vertical section through a fireplace incorporating apparatus according to the invention; Fig. 2 diagrammatically shows the face of the light source, indicating the arrangement of the light elements; Fig. 3 shows the arrangement of the controller for controlling light elements; and Fig. 4 shows a reflecting means comprising a holographic mirror.

Fig. 1 shows a fireplace 1 which consists of a housing 2 into which the flame simulating apparatus (indicated generally at 3) is built. The flame apparatus 3 includes a light source 4 comprising various light elements 5, which are preferably light-emitting diodes (LEDs). These light elements 5 may alternatively consist of conventional light bulbs or other light sources. The apparatus 3 further comprises a reflective element 6 and a diffuser screen 7 through which a viewer may view an image of the light elements 5, thrown against the diffuser screen 7 by the reflective element 6.

The apparatus 3 also incorporates a controller 9 for controlling the light source 4, as will be described.

It is useful to describe briefly the manner in which the apparatus operates to create a flame effect, before describing the apparatus in more detail.

Briefly, the light source 4 creates a changing pattern of light which is projected onto the mirror 6. The mirror 6 then directs the light towards the diffuser screen 7 through which the viewer 8 views the image in the mirror 6. The viewer therefore sees a flame effect behind a panel which, in this example, is substantially vertical, thereby simulating the vertical glass window present in many designs of real coal and gas fires. This aids the quality of the simulation.

The structure and function of the various components can now be described in more detail, as follows.

Fig. 2 shows the layout of the various LEDs 5 which make up the light source 4. In this example, the position of red LEDs is indicated by 5A, and the posiiton of yellow LEDs is indicated by 5B. As can be seen, a central line of red LEDs 5A is crossed by generally perpendicular lines of yellow LEDs 5B. The central line will, in use, be arranged substantially horizontally across the source 4, with the yellow LEDs 5B running in lines up the source 4. This creates an image to the viewer of a red bed of a fire, from which yellow flames are rising, simulating a coal flame fire. The image is further enhanced by the controller 9, which is operable to turn the LEDs 5A, 5B on and off in various patterns and at various speeds. In a preferred mode of operation, the red LEDs will remain permanently illuminated (to simulate glowing embers), while yellow LEDs will be sequentially activated along their lines in various patterns, to simulate flames rising, falling and flickering.

Other flames can be simulated by changing the layout of the LEDs, their colours, and the patterns of their illumination. For instance, it is found that a coal fire is best simulated by the use, predominantly, of red and yellow LEDs, while a wood fire is best simulated by the use, predominantly, of yellow and orange LEDs. A gas fire is best simulated by the addition of some blue LEDs.

Fig. 3 shows the arrangement of the controller 9. The controller 9 consists of a micro-controller for switching the LEDs 5 individually or in groups, a driver circuit 11 which acts as an interface between a micro-controller 10 and the light elements, and current limiting resistors 12. The micro-controller 10 can be a microprocessor based programmable device or a simple timer. The driver circuit 11 can consist of an amplifier based, for instance, on transistors or operational amplifiers. Very many designs of circuit suitable for driving an LED from a microprocessor, timer or similar device are well known to the skilled reader.

Fig. 4 shows the reflective member 6 which consists of a support member (not shown in Fig. 4) which may be flat, concave or convex, and on which a holographic mirror 13 is supported. It is found that a holographic mirror based on the Harry Basken's principle produces good results. A holographic mirror 13 of appropriate form can be purchased as holographic gift paper, such as is produced by the company Hype Associates Ltd., of Upton Wirral, Merseyside, United Kingdom. The holographic mirror 13 is provided with a pattern 14. The pattern 14 is of a set of wavy lines. In the arrangement as shown in Figs. 1 to 4 the wavy lines extend in the generally vertical direction up the mirror.

It is found that this pattern from the top to the bottom of the mirror as shown in Fig. 4 produces the most natural looking flame effect. In particular, the wavy lines cause the flame images to rise and fall with a non-linear appearance, aiding the simulation effect.

The screen 7 may be a sheet of any suitable semi-opaque material, such as acid-etched or obscured glass, or a synthetic plastics material.

There is thus described an apparatus for simulating a flame with a number of advantageous features. It provides a natural looking flame effect, yet its components are cheap. The apparatus is compact because of the use of a reflective surface; and it is therefore very easy to fit into existing fireplaces.

Because of the use of a controller for controlling the light source the effects can be varied to avoid appearing repetitive. Various effects can be produced including gas, coal and wood flames. The application of a reflective surface and a diffuser enables the viewer to view the flames from a wide range of viewing angles.

In use, the red LEDs 5A are maintained illuminated to simulate the embers of the fire. The lines of yellow LEDs 5B are illuminated in various changing patterns. The patterns can be made to change unpredictably, or randomly, with sufficient sophistication of the controller 9. An image of the source 4 is viewed through the screen 7, which blurs the image, and through the holographic mirror 6, which further distorts the image. The result is a soft image highly reminiscent of a real fire.

The simulation can be further enhanced by programming the controller 9 to vary the simulation over a lengthy period, such as several hours. Initially, small flames of a newly kindled fire would be simulated. The flames would then be increased in size as the simulated fire grows. Finally, the flames would dwindle, as the fire dies down.

Various modifications may be made without departing from the scope of the invention. For example, an additional light source may be fitted for simulating the wood and/or coal. Many types of reflector could be used, including plain or obscure-glass mirrors, multi-faceted mirrors, and prismatic or other wavelength selective mirrors. The apparent flame height will depend on the relative angles of the mirror, light source and diffuser, so that a further improved simulation can be achieved by providing for the angle of one or more of these components to be adjustable or to be continuously varied, preferably under the control of the controller 9.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.