-1- 2391614
Flame Simulating Apparatus The present invention relates to a flame simulating apparatus, preferably for use in a heating appliance to create a flame picture. It also relates to an ember simulating apparatus for creating the appearance of glowing embers, preferably in a heating appliance. It further relates to heating appliances when incorporating such flame simulating apparatus and/or ember simulating apparatus.
Heating appliances that strive to mimic the appearance of a real fire to have been well known for a long time. So called flame-effect fires use a variety of mechanisms to simulate flames whilst hidden or discrete heating elements provide the actual heat. Several methods have previously been used to create these flame simulations, and whilst some have proved adequate they have by no means realistically emulated flames.
15 By far the most common method utilises one or a few red/orange fixed bulbs that cast light onto a number of reflective strips that are moved by an air current generated by a fan. To an observer, the fluttering motion of the strips causes the coloured light incident thereon to appear to move somewhat like a flame. This method, whilst widely used, produces an effect that is little like a 20 real flame and has none of the natural variation that is present in the flames of a real fire.
Improvements to this method, wherein a mirror or other reflective surface is used to alter the apparent depth of view have been proposed.
Whilst these are beneficial, they only address the apparent twodimensionality 25 of the flame effect created. They do not make the flames seem any more
- 2 real. What is more, the existing methods do not permit variation in the type of flame effect generated. Each provides only one visual effect which cannot be changed without changing the mechanism by which it is created.
In addition to the desire to simulate flames it is also desired to simulate 5 the glowing embers of the fire, especially when creating a coal effect. Such ember effects have previously used translucent shaped screens through which fixed (perhaps coloured) light shines, to give the appearance of glowing logs/coals. The effects created by this method have been improved slightly by various methods, including the use of moving fans that cast moving shadows to on the shaped screen to give a flicker effect. These have, however, provided I only poor imitations of a bed of glowing embers.
It is an aim of the present invention to provide an apparatus that improves the flame simulation ability of flame-effect appliances. It is a further aim to provide means for improving the ember simulation of such appliances.
15 Therefore, according to the present invention there is provided a flame simulating apparatus for use in creating a flame image, which flame simulating apparatus comprises a light source; a lens associated with the light source, and formed from a plurality of laminated sheets of a translucent material, through which light from the light source is projected; and a screen onto which i 20 the projected light is incident to create the flame image. 1 The light from the light source passes into and then out of the lens and usually travels therethrough in a direction generally parallel to the plane of the sheets from which the lens is formed. The use of laminated sheets of translucent material allows the light derived from the light source to be i 25 internally refracted and the resultant light to be intensified and striated. When
- 3 directed on to the screen this generates numerous combinations and effects, which in turn generate a far more convincing flame image.
The present invention can be achieved by using any light source, as it is the effect of the lens that is most important. However, the invention is 5 particularly well suited to use with light emitting diodes (LEDs), and it is therefore highly preferred that they are used as the light source.
The invention may utilise a single light source directed through one or more lenses, but it is preferred that it comprises a plurality of individual sources - for example an array of LEDs. The or each light source may be 10 directed through one or more lens. The use of multiple lenses, each with an associated light source, allows the flame image to be created from a compound of the light projected from these lenses, which gives rise to a yet more realistic display.
When a number of LEDs are used, these may be all the same colour, 15 or instead a plurality of differently coloured light emitting diodes may be used.
The use of various colours, appropriately mixed and controlled will together generate a further improved flame image on the screen.
The or each lens used is preferably formed from 3 or more sheets of translucent material laminated together by a suitable adhesive or other 20 mechanically bonding. Each lens generally has an incident face through I which light enters the lens and a resultant face through which light exits the lens. In general the incident face comprises the face formed by the corresponding edges of the laminated sheets, and the resultant face is formed by the opposed edges of the laminated sheets, with the light moving generally i 25 parallel to the plane of the laminated sheets.!
- 4 ( The light passing through the lens tends to be reflected off the internal surfaces of the laminated sheets due to shallow angles of incidence.
However some light may escape from the sides. To mitigate this the faces of the lens other than the incident and resultant faces may be covered with 5 inwardly directed reflective material which reflects any light that escapes from! one of these faces back into the lens. Instead, the other faces may simply be made opaque, but this is less effective as it results in the absorption of some of the light.
As mentioned above a plurality of lenses may be used wherein each 10 lens has an associated light source (which can be the same for each or can I be independent), which lenses direct the light therefrom onto the same screen. Such independent lenses may be independently positioned so as to direct light on to different or overlapping parts of the screen.
The lenses may be simple blocks formed from laminated sheets, with 5 generally flat incident and resultant faces. Altematively the incident and / or resultant faces of the lenses may be shaped to improve the name picture generated. This shaping can be in either or both planes of the faces i.e. width wise or lengthwise. The lenses may also be provided with occlusions in the light path.
20 The flame image created by the present invention is so effective that it I can be projected on to a plain flat screen, with the appearance of movement being created by control of the light source, particularly when the source comprises multiple LEDs. However, the screen may be moveable further to enhance the flame image. The screen may comprise a complete sheet of 25 moveable reflective material, or it may use conventional discrete strips of
- - reflective material, which strips are independently movable. These moveable strips or the moveable screen may be moved by an air current that is blown thereover, the current being normally generated by a blower such as a tangential fan.
5 The sheets of translucent material from which the lens is formed may be any material with suitable transmissive properties, such as glass or plastics material. Clear acrylic is particularly preferred due to its optical and structural properties. The translucent material lens may be clear, but may also be tinted to colour the projected light. A lens may be formed from all the same colour 10 sheets, or from a composite of differently tinted sheets.
The operation of each light source may be independently controlled.
They may be switched on and off and their intensity may be varied to control the amount of light emitted. When an array of multiple light sources is used they may be subject to overall control such that switching and/or intensity control may be coordinated to achieve a flame image that appears to flicker and move like a real fire. This overall control may be achieved by a microprocessor or other electronic circuitry. The microprocessor may be able to operate the flame simulating apparatus in a number of predetermined patterns so that a user may alter the flame image simply by selecting the 20 appropriate mode.
According to the present invention there is also provided a heating appliance incorporating a flame simulating apparatus as discussed above.
Such a heating appliance might usually include a heater, a mounting arrangement mimicking a fireplace, and a flame simulating apparatus.
- 6 ( As discussed above the present invention provides a significantly improved flame effect as compared to existing technology. However many flame effect fires also strive to emulate the burning embers that a normal fire also has.
5 Therefore according to the present invention there is yet further provided an ember simulating apparatus for use in creating the appearance of ember glow in a heating appliance, which ember simulating apparatus comprises a light source containing a plurality of discrete light elements; a fluorescent or reflective mounting panel in which the lighting elements are 10 mounted and from which the light therefrom is projected; and a translucent ember effect screen on to one side of which the projected light is incident so as to create the desired ember effect when viewed from the other side thereof.
The translucent ember effect screen may be contoured to represent coal or log shapes. A variety of differently coloured light elements may be used. The lighting elements are preferably LEDs, whose terminals extend from the rear of the mounting panel so that they may be attached to electrical connections. These lighting elements may be switched on and off and their intensity controlled in patterns such that the effect generated appears to better go represent an ember glow than existing techniques. A controller in the form of a microprocessor may coordinate and control the illumination of these LEDs, and the controller may be able to alter the pattern of illumination such that the particular type of ember glow perceived is changeable.
According to the present invention there is also provided a heating 2s appliance incorporating an ember simulating apparatus as discussed above or
-7 one incorporating both a flame simulating apparatus and an ember simulating apparatus according to the present invention.
In order that it may be better understood, but by way of example only, the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a flame effect appliance incorporating one embodiment of flame simulating apparatus and one embodiment of ember simulating apparatus according to the present invention; Figure 2 is a view of a projector of the apparatus of Figure 1 including 10 the light source and the lens; Figure 3 is a side view of the projector of Figure 2; Figure 4 is a top view of the projector of Figure 2; Figure 5 is an underside view of the projector of Figure 2; Figure 6 shows a range of different lens cross-sectional shapes; and 15 Figure 7 is an exploded perspective view of an embodiment of lens and light source alternative to that shown in the previous figures.
A flame effect appliance, generally indicated 10, is shown in Figure 1.
The appliance comprises a rear part 11 and a decorative front part 12 which is fixed over the rear part 11 in use, but is shown removed so that the flame 20 simulating apparatus can be seen.
A number of projectors 14, each of which comprise a lens and several LEDs (these are explained in more detail with respect to the following Figures) , are mounted on the rear part 11. Strips 15 of thin flexible reflective material are mounted vertically on the rear part, in front of a back screen 16 as and are tethered at either end. A fan (not shown) passes a current of air over
- 8 these strips 15 and causes them to flutter. An ember display panel 17 is provided at the front of the rear part and ember LEDs 18 are mounted therein such that light from these is outwardly directed.
The front part 12, which is shown partially cut away, comprises a 5 decorative frame 20 around a generally rectangular viewing screen 21. The viewing screen is formed from smoked glass that is partially translucent, and so that an image projected thereon from one side is viewable from the other.
In the lower region of the front part 12 there is provided an ember effect screen 22, which is shaped in this embodiment to mimic burning coals, but to could be shaped to mimic other combustible material such as logs. This ember effect screen 22 is usually partially translucent and may be formed from fibreglass or plastics material.
The LEDs in the projectors 14 transmit light through their associated lenses, which light is then projected on to the strips 15 and the back panel 16.
5 The projectors 14 are orientated such that at least some of the light that falls on the strips 15 or back panel 16 is reflected outwardly through the viewing screen 21 such that the appearance of flames is generated thereon.
The light from the ember LEDs 18 mounted in the ember display panel 17 is directed outwardly toward and through the ember screen 22, such that it 20 iS appropriately illuminated. By control of the ember LEDs 18 the ember effect can be enhanced by making it appear to move and flicker as desired, without the use of complex mechanical arrangements as were previously used in the art. Control and coordination of the illumination from the various light 25 sources, namely the ember LEDs 18 and the LEDs in the projectors 14, is
-9- performed by an electronic controller 25 connected to the LEDs by wires 26.
This controller has an associated power supply (not shown) and is also in control of the fan (also not shown). The controller can alter the timing and degree of illumination of the Lads either to allow selection of different modes 5 of illumination or to improve the name appearance that is created. The controller may be able to create a random phase pulsing effect that can enhance the flame image, by improving the random nature of the flame image. The projector 14 shown in Figure 1 is shown in more detail in Figures to 2, 3, 4 and 5. The projector comprises a lens 30 and a light source, in the form of three LEDs 31, which LEDs are attached to the lens 30 by a channel-
shaped holder 32. The lens 30 is formed from three sheets 33, 34, 35 of acrylic plastic laminated together. The light emitted from the LEDs 31 enters the lens through the incident face 37 thereof, and passes through the lens 15 until it is transmitted from the resultant face 38, from where it is directed toward the reflective strips 15. The other faces of the lens are coated with an inwardly reflective material such that light cannot escape save from the resultant face.
As the light passes through the laminated lenses it is refracted such 20 that the projected light is intensified and striated for projection on to the screen. This creates a more realistic flame image when reflected by the strips 15 onto the viewing screen 21.
Figure 6 shows a number of possible alternative profiles for the lenses.
For clarity the lens are shown in side elevation, without any other parts being 25 visible. In these versions, the incident surface 37 of each lens remains
- 10 generally flat, and the resultant surfaces 38 are shaped according to the desired effect. It is possible for the variation to be in the plane normal to that of the current view, it is also possible for the incident surfaces to be appropriately shaped. Variation in the length of a lens between its incident 5 and resultant faces can also be used to control the flame images generated, as can the use of partial occlusions in the light path.
It will be appreciated that by selecting appropriate colours, types and arrangements of LEDs (or indeed other light sources), by selecting the shapes, sizes and material of the lens, and by varying the type of screen on to to which the image is projected, an almost infinite number of flame effects can be generated. These can range from representations of fires significantly that are more realistic, through to flame effects that are more stylised and intended to provide an interesting light effect rather than simply to imitate a fire. For example by use of a correctly polished and shaped lens the present invention 15 can achieve diffraction of white light passed therethrough which can project an image containing the whole spectrum.
In Figure 7 there is shown an alternative embodiment of projector, which is generally indicated 40. This embodiment has a lens 41 formed from many sheets 42 of translucent material laminated together. The LEDs 43 20 (only two are shown, but in use many more would be utilised) that form the light source are located in a mounting panel 44 which is provided with multiple apertures 45. These apertures are arranged over the entire surface of the mounting panel 44, but in Figure 7 they are only shown at one end thereof.
An appropriate mixture of LEDs 43 are fixed in some or all of the 25 apertures 45, and the lens 41 is fixed above the mounting panel 44 such that
- 11 the light from the LEDs 43 can pass into the lens 41. The electrical connection terminals of the LEDs 43 may then be connected by wires to a controller, or may be integrated with such a controller by attaching them onto a printed circuit board (not shown). Any spare apertures 45 may be used to fix down the mounting panel 44.
The mounting panel 44 is designed for modular connection to other such units. One end of the panel is provided with a tongue 47 and the other end with a corresponding groove 48, so that by locating the tongue of one panel into the groove of another panel the two panels may be joined together.
to The projectors discussed above could also be used to project an image onto the ember screen, not just on to the flame effect screen. This would allow yet more complex ember effects to be generated.
Whilst the present invention has been discussed primarily with reference to its use in heating appliances, it will be appreciated that the flame 15 and ember simulating apparatus will be useful in other, perhaps purely decorative purposes. It does not have to be associated with a heating or air conditioning appliance although it often would be.