DE29500213U1 - Thin film protection filter - Google Patents

Description

Thin film shielding filter

Inventor: Walter Rath, Cologne.

Description

Area affected by the innovation

The sun not only gives us visible light, but also ultraviolet light, especially the vital heat (also in the form of rays, just like light). But sometimes it is too much. It gets too hot for us. Carpets and curtains are bleached. The ultraviolet light, which not only gives our skin a healthy-looking tan, can sometimes burn it and cause cancer.

The innovation provides for sun protection through optical filters applied to curtains, roller blinds, Venetian blinds, awnings, parasols or applied to thin plastic films that are glued to glass panes.

State of the art and knowledge

Physicists have calculated and created filters that, as (very) thin layers on glass, only let through the sun's rays that we want. The coating material, the respective layer thickness and the number of layers all play a role as variables in the calculation.

In vacuum chambers, glass lenses and even large window panes are provided with so-called optically thin layers by evaporating metals, metal oxides, semiconductors or non-metals. Optically thin means that a layer is no thicker than a quarter of a light wavelength (or a multiple thereof), i.e. in the range of about a ten-millionth of a meter (ie 100 nanometers = 100 * 10 " ⁹ m).

Theoretically, a filter could be "built" from many layers that allows visible light to pass through without restriction (Fig. 1). But that would be unaffordable and would not suppress the light that blinds us and bleaches objects. Fortunately, our eyes are so adaptable that a filter that matches the example curve seems almost ideal to us (Fig. 2).

It should be mentioned that optically thin layers generally serve as heat protection filters, i.e. they keep the sun's heat out of a room in summer and prevent the heat from the heater from escaping outside in winter. The heat is reflected back to where it came from.

It is state of the art to coat large panes of glass in huge vacuum machines, which are often also designed as half-mirrors so that you cannot see through them from the outside to the inside (from light to dark). There are also thin films, for example, that make the panes appear golden or metallically bluish (in addition to the properties mentioned above).

Vacuum machines are now also in use, in which rolls of up to 2 meters wide are wrapped in a kilometer-long plastic film. For example, a (single) layer of aluminum is vapor-deposited onto the plastic. Such films are mainly used for packaging.

Now, for example, more or less heavily "perforated" plastics are being coated with metal, especially aluminum, which is used as material for blinds. However, you cannot see through them, or at least only to a very limited extent, which calls into question the original function of a window, namely to be transparent, i.e. to let light through.

problem

Coated glass panes are quite expensive because the vacuum machines have to be very large and glass (because of its fragility) has to be handled quite carefully. It is also expensive to deliver the coated glass to the consumer and fit it into frames. In particular, it is very expensive to replace existing window glass, i.e. uncoated with coated.

Coated plastic material with more or less large pores is also relatively expensive and prevents not only the passage of heat but also the entire light spectrum.

innovation

What is new (and has already been implemented as a laboratory model), but is not the subject of this utility model application, is to use a machine used to manufacture packaging material to apply thin layers to transparent (crystal-clear to milky or pre-colored) plastics (as films of various thicknesses, so that they can also be cut to sufficiently rigid slats if necessary), which

♦ serve as a protective filter to prevent heat from passing through (as an "infrared mirror"),

♦ reduce or completely block ultraviolet light (i.e. partially or completely reflect),

♦ attenuate or color visible light as desired, including golden, bluish or silvery,

♦ reflect more or less strongly overall, for example to only allow one to see through the film in one direction.

♦ Patterns can also be coated onto the plastic film or slat or printed in the usual way.

♦ It is also state of the art to vaporize material that is extremely water-repellent, e.g. to prevent "fogging" (condensation of moisture).

Any combination for the above list is possible.

Coated plastic films can be subsequently glued onto glass panes, e.g. to prevent the unpleasant greenhouse effect in a car.

This means that the existing glass panes do not need to be replaced with directly coated ones, which are quite expensive, and the costs for the labor must also be taken into account.

Sticking such a film on has the side effect that the films serve to stabilize the carrier material, e.g. as in the case of so-called laminated glass.

However, it is easier to roll the foil onto a roller blind or use it as a curtain, in order to be able to influence the passage of too much light and heat through a window pane as required.

There is also the advantage of possibly using different blinds, for example in winter those that absorb little or no visible light but let the heat into the room, while in summer you may be interested in protecting yourself against the intense and blinding sunlight as well as almost completely suppressing the heat.

The costs for purchasing roller blinds with filter films are hardly different from those that are commercially available without such filters.

However, significant price differences must be expected since, as already mentioned, the manufacturing costs depend on the filter quality.

As a rule, fairly simple filters are sufficient for higher requirements, since, as already mentioned (Fig. 2), our eyes adapt ideally to changing lighting conditions. For example, they adapt to incandescent lamps, whose higher proportion of red light we do not notice (compared to the higher proportion of blue during the day when the sun is shining). Only a color reversal film (slide film) can see these differences particularly clearly. (That is why there are still different reversal films for daylight and artificial light.)

There are roller blinds that can be pulled out in all possible directions: from top to bottom, to the side, horizontally, e.g. to provide heat protection under a roof window that is installed almost horizontally.

Depending on the thickness of the plastic base material, the plastic can be cut into strips after vapor deposition in the vacuum machine in order to be processed as slats for blinds.

The plastics or (possibly impregnated, i.e. water-repellent) textile fabrics produced as filters or mirrors can also be used for awnings and parasols.

For example, if an awning, i.e. a roll-up sunshade roof, is installed on the sunny side in front of a window or over a balcony or terrace and is covered with the coated material, heat or - generally speaking - light penetration can be completely prevented or - depending on the requirements - more or less filtered out. In any case, unwanted wavelengths are reflected back.

Sunshades can also be equipped with the filter material, whereby some of the ultraviolet light could be desirable for tanning the skin.

Preferably, an unpleasant build-up of heat under the awnings or parasols is prevented.

Instead of transparent or just transparent plastics of various colors and all possible profiles, natural products such as linen fabric can - as already mentioned - also be coated and processed into roller blinds, curtains, awnings, parasols, etc. according to the suggestions mentioned above.

Claims (11)

Protection claims: 1. Arrangement in front of or behind glass panes, in particular window panes, characterized in that it consists of one or more optically thin protective filter layers, i.e. transmission or reflection filters, applied to transparent or merely transparent plastic material of various thicknesses and possible basic colors, as well as all possible profiles or to corresponding natural products, such as textile fabrics. 2. Arrangement according to claim 1, characterized in that the material provided with a protective filter is wound onto a roller blind known per se and can be pulled out vertically, horizontally or in any other direction. 3. Arrangement according to claim 1, characterized in that a conventional, per se known curtain or drape consists of the material coated with a protective filter. 4. Arrangement according to claim 1, characterized in that the coated material is cut to size slats for blinds known per se, located in front of or behind the window. 5. Arrangement according to claim 4, characterized in that such a blind is located within the two panes of a double or multiple glazing. 6. Arrangement according to claim 1, characterized in that a known awning, i.e. a roll-up sun protection roof, is made of the coated material. 7. Arrangement according to claim 1, characterized in that the coated material is preferably applied or glued to the glass as a thin film. 8. Arrangement according to claim 1 and 7, characterized in that this film is located between the panes of a double or multiple glazing. 9. Sunshades known per se, characterized in that such sunshades are equipped with optically thin protective filter layers, i.e. with transmission or reflection filters, applied to plastic material or to natural products (such as textile fabrics). 10. Arrangement according to one of the above claims, characterized in that the material serving as a protective filter is additionally provided with patterns produced either directly during the coating process or before or after the coating by printing or gluing. 11. Arrangement according to one of the above claims, characterized in that a water-repellent layer is applied to the optical protective filter.