GB2488012A

GB2488012A - Flame image enlarged onto a screen

Info

Publication number: GB2488012A
Application number: GB201200862A
Authority: GB
Inventors: John Leslie Watts
Original assignee: Flamerite Fires Ltd
Current assignee: Flamerite Fires Ltd
Priority date: 2011-02-09
Filing date: 2012-01-19
Publication date: 2012-08-15
Also published as: GB201200862D0; GB201102235D0

Abstract

An imaging apparatus has an electronic moving flame image generator (e.g a media player), enlarging means for the image and a screen on which a final image is displayed in use to a viewer. The enlarging means can have a mirror to fold the optical path, possibly to the side about axis P-Pâ (fig 2), lens or curved mirrors, a light blocking mask. Part of the screen can be reflective and another part at least partially light transmitting (e.g. having a diffusing texture), the effects varying across or down the screen. A display of the generator LCD or plasma lit by an LED. The image generator can distort the image to compensate for geometrical keystone distortion (fig 5). A thin sheet Fresnel lens can also magnify artificial fuel (fig 6). A front window can act visually one-way. The apparatus can be part of an electric or gas fire.

Description

TMAGING APPARATUS

BACKGROUND OF THE INVENTION

The present invention relates to a display device and more particularly to an apparatus and method for simulating a realistic flame effect for use in an electric or gas fire.

Many electric or gas fires include some form of flame-effect image located behind or in front of a fuel effect. The latter may be realistic (coal or wood) or decorative (for example based on pebbles or glass). The prior art generally provides unsatisfactory simulation of a real fire in that simulated flames do not appear to emerge from the centre of the fuel effect.

There is a requirement for a more realistic fire simulation in which thc viewable flame image is located at the centre of a fuel effect.

SUMMARY OF THE INVENTION

An imaging apparatus comprising an image generator means for creating a moving image depicting flames, enlarging means for enlarging said moving image and a screen on which a final image is displayed in use to a viewer, said image generator means including an electronic image display device on which said moving image is created, arranged in such a way that the image generator means, enlarging means and screen define an optical path along which the moving image passes.

A more complete understanding of the invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings. For the purposes of clarity details relating to technical material that is known in the technical fields related to the invention have not been described in detail.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.! is a schematic unfolded side elevation view of one embodiment of the invention.

FIG.2 is a schematic side elevation view of a particular embodiment of the invention.

FIG.3 provides schematic side and elevation view of the optical components from the light source to the first folding mirror in the embodiment of FIG.2.

FIG.4 provides front elevation view of a first and second folding mirrors and the screen in the embodiment of FIG.2.

FIG.5 provides a schematic front elevation view of a pre-distorted image frame displayed on the LCD panel used in the embodiment of FIG.2.

FIG.6 illustrates a means for providing a magnified image of a fuel bed.

DETAILED DESCRIPTION OF THE INVENTION

According to one aspect of the present invention illustrated in the schematic side elevation view of FIG. 1 an apparatus for simulating a flame effect and suitable for use in an electric or gas fire comprises an image generator means for creating a moving image, means for enlarging said moving image and a screen on which a final image is displayed.

The image generator means comprises at least one media player means, at least one media storage means holding a sequence of frames of moving flame image and an electronic image display device. The moving flame image held in the media storage means is transmitted in a continuous loop to the media player which transmits the image to the display screen.

The imaging apparatus preferably further comprises a fuel effect as hereinbefore defined such as artificial coals preferably disposed in front of and behind the screen.

The electronic display device may be a liquid crystal display panel (LCD) illuminated by light from at least one white light source. In certain embodiments of the invention a condenser lens may be required to control the spatial uniformity of the light as shown in FIG. 1. Advantageously, the light source is a LED. Examples of the electronic image display device are an LCD panel or a plasma display. The invention is not limited to any particular type of electronic display technology or light source.

The upper portion of screen is preferably highly reflective or high in gain (a measure of reflectivity of light), or degree of light reflection of the screen may be perfectly uniform across its entirety. Gain in this case is the measure of how bright the image is on the screen.

Gain is controlled by diffusion of the screen however the most desired brightness of the screen depends on ambient light levels and the luminous power of the image source. The lower portion of the screen is preferably at least partially light transmitting. At least one of the surfaces of the screen is preferably textured to provide light diffusion. The light diffusing characteristics may be designed to vary across the screen. In another embodiment, the screen is graduated from top to bottom so that more light is reflected at the top than the bottom, or the reverse.

The enlarging means preferably includes at least one mirror (labelled as a first beam-folding mirror in FIG.1) for folding the optical path in plan view. In other words, referring to FIG. 1, the first beam-folding mirror rotates the optical train from the lamp to the biconvex lens into a direction normal to the plane of the drawing. The rotation takes place around the axis labelled by the symbols PP'. Advantageously, the mirror rotates the optical train through degrees.

The enlarging means preferably also includes at least one planar mirror (labelled as a second beam-folding mirror in FIG. 1) for folding the optical path in a side elevation.

The enlarging means preferably includes at least one lens. In the embodiments of FIG. 1 two lenses comprising a plano-convex lens and a biconvex lens are used to control the projected image size and sharpness. The invention does not assume any particular type of lens. Any type of lens known to designers of projection displays may he used to apply the invention.

The enlarging means preferably includes at least one mask e.g. an aperture stop for blocking stray light. An example of a mask is a piece of metal or plastic with an aperture in it.

One particular embodiment of the invention is illustrated in FIG.2-3. FIG.2 is a side elevation view in which the optical train up to the first beam-folding mirror is folded into a direction normal to the drawing. HG.3 provides plan and side elevation views of the optical train from the source to the first beam-folding mirror. Other equivalent combinations of lenses and mirror will be apparent to those skilled in the art of optical design.

In one embodiment of the invention the second beam-folding mirror is replaced by a curved mirror.

Preferably the imaging apparatus is also provided with a casing and the casing is usually inset into a wall or other building component. Alternatively the casing may be free-standing, e.g. in the form of a stove or fire, or the fire may be hung on a wall. Preferably the casing is designed to minimize the ingress of ambient light, in which case it would not be transparent.

The image generator means preferably includes means for pre-distorting the input image to compensate for geometrical optical distortion created by the enlarging means, e.g. by tilting the lenses or by pre-distorting the image on the electronic image display device.

Typically, projection displays in which the projection path is at a steep angle to the screen suffer from the problems of key-stoning and pincushion distortion. FIG.5 shows the geometry of the pre-distorted image that provides a rectangular output image when projected through the apparatus of FIGS.2-3.

In one embodiment of the invention the apparatus of FIG. 1 further comprises a lens, preferably in the form of a thin sheet, adjacent to and preferably forming an interface with the surface of the lower portion of the screen, as shown in Figure 6. The lens forms a magnified virtual image of the fuel effect (artificial coals) behind the screen. Advantageously, the lens is of the Fresnel type as conventional curved surface lenses of the same power would result in a much thicker screen. The upper edge of the lens is preferably cut in the shape of a cross-section of the fuel effect (artificial coals).

The front panel in Figure 1 is a window, and although this may be transparent, or indeed clear, it is preferably slightly etched or tinted or has a film or coating applied to make it visually more one-way with the aim of making the inside of the appliance darker than on the outside.

The darker the area in which the projected image has to travel the clearer and stronger the image will be, once captured on the screen. Too much ambient light coming from outside the appliance will cause diffusion or interference with the projected image, thus making it weaker and less likely to be seen upon hitting the screen.

It will be appreciated that certain features of the invention which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are for brevity described in the context of a single embodiment, may also be provided separately or in any suitable combination.

Claims

CLAIMS1. An imaging apparatus comprising an image generator means for creating a moving image depicting flames, enlarging means for enlarging said moving image and a screen on which a final image is displayed in use to a viewer, said image generator means including an electronic image display device on which said moving image is created, ananged in such a way that the image generator means, enlarging means and screen define an optical path along which the moving image passes.
2. The imaging apparatus of claim 1 wherein the upper portion of said screen is reflective and the lower portion of said screen is at least partially light transmitting.
3. The imaging apparatus of claim 1 or 2 wherein the screen is graduated from top to bottom so that more light is reflected at the top than the bottom,
4. The imaging apparatus of claim 1 or 2 wherein the screen is graduated from bottom to top so that more light is reflected at the bottom than the top,
5. The imaging apparatus of claim 1 wherein the degree of light reflection of the screen is perfectly uniform across its entirety.
6. The imaging apparatus of claim 1 wherein said image generator means includes an electronic memory device for storing and playing back a sequence of image frames.
7. The imaging apparatus of any preceding claim wherein said electronic image display device is a liquid crystal display panel illuminated by light from at least one LED.
8. The imaging apparatus of any preceding claim wherein said screen has light diffusing characteristics.
9. The imaging apparatus of claim 8 wherein said screen has light diffusing characteristics that vary across a surface of the screen.
10. The imaging apparatus of any preceding claim wherein said enlarging means includes at least one mask for blocking stray light.
11. The imaging apparatus of any preceding claim wherein said image generator means includes means for pre-distorting the moving image (the input image) to compensate for geometrical optical distortion created by said enlarging means.
12. The imaging apparatus according to any preceding claim wherein a fuel effect is disposed in front of and behind said screen.
13. The imaging apparatus according to any preceding claim further comprising a lens adjacent to the lower screen portion.
14. The imaging apparatus of claim 13 wherein the lens forms an interfacc with a surface of said lower screen portion.
15. The imaging apparatus of claim 13 or 14 in which the lens comprises a Fresnel lens.
16. The imaging apparatus according to any preceding claim wherein said enlarging means includes at least one lens.
17. The imaging apparatus according to any preceding claim wherein said enlarging means includes at least one mirror for folding the optical path through said enlarging means in a side view.
18. The imaging apparatus according to any preceding claim wherein said enlarging means includes at least one mirror for folding the optical path through said enlarging means in a plan view.
19. The imaging apparatus according to any preceding claim wherein said enlarging means includes at least one curved mirror.
20. The imaging apparatus according to any preceding claim in which the front of the fire comprises a window which is adapted to make it visually more one-way so that the inside of the appliance darker than on the outside.
21. The imaging apparatus according to any preceding claim which is adapted to make the inside of the appliance darker than on the outside.
22. The imaging apparatus according to claim 1 and substantially as herein described.
23. The imaging apparatus according to claim 1 and substantially as described with reference to any one of Figures 1 to 6.
24. The imaging apparatus according to any preceding claim which is incorporated into a fire.IS