FR2660964A1 - Sun screen - Google Patents

Abstract

Variable opacity device which can be applied to windows. System consisting of two filters which unroll in opposite, mutually parallel, directions, thereby allowing a gradual, reversible, degree of opacity to be obtained ranging from virtual transparency to complete darkness. The filters (1) and (2) are made so that the degree of opacity over the area (3) and (4) is uniform. The filters can be moved by rolling them up (5a, 5b and 6a, 6b) which can be carried out manually or with the aid of one or more motors. The distance between the two filters is variable, thereby allowing a wide range of applications (windows, ceilings, doors, greenhouses (conservatories), verandahs, etc.).

Description

 The device which is the subject of the present invention is a device making it possible to vary the transparency.

Ie a new type of sun visor.

The different levels of transparency are traditionally obtained by separate filters (tinted windows) which make it possible to obtain different states of transparency. Other systems used by windows such
blinds allow darkening (progressive for some) but hinder vision. These systems do not allow continuity in the variation of transparency.

The present invention therefore makes it possible to obtain on the zone (3) and
(4) of Figure 1 this continuity by means of two rollers
((5) and (6) figure 1) of suitable filters (1) and (2) figure 1)
Each filter has a length greater than that of the zone which it is desired to equip with the system described. attached to each end on a roller, it can be moved back and forth
(we reason here on a vertical arrangement of the rollers, but it is obviously possible to arrange them in another way
(horizontal for example)). Each filter goes lighter
(full transparency) to darkest (total black) .The gradient of the two filters is opposite (figure 2) .The filters are made of plastic films for example. Circulating in opposite directions, they together ensure a continuous, reversible and homogeneous darkening on the area interested domain (3) and (4) (figure 2.

This is due on the one hand to the properties of the filters and on the other hand to their arrangement. The uniformity of the filtering is not modified by winding or unwinding the filters. The displacement of the filters only modifies the light intensity
transmitted.

The operating principle is as follows each fijm (l) and (2) has a variable transparency. The variation can be continuous or discontinuous although the continuous variation seems to be the most interesting. For example: p power i being the percentage of light transmitted by the filter (2) at a point G (figure2) and p power j being the percentage of light transmitted by the filter (1) at this point G (figure 2) then the amount of light passing through the two filters is p power (i + j). The filters are made in such a way that on all areas (3) and (4) it is the same. For example here, the variation of the filtering of each filter is of the exponential type.

PRESENTATION OF THE FIGURES
Figure (1) outlines the main lines of the invention.
see the two filters (1) and (2) one rising (2) (symbolized by an arrow up) the other descending (1), The rollers located at one end (Sa) (5b) and a the other (ba) (6b).

Figure 2 details Figure 1 by showing how the characteristics of the filter films (1) and (2) which, each transmitting a variable intensity, by superposition produce a uniform transmission of light on the two zones (3) and (4) (here the light intensity transmitted through the lens hood is equal to p power (i. j) times the light received).

Figure 3 shows an embodiment of a double-glazed window equipped with the sun visor.

Figures 4h and 4B show an embodiment where the filters are placed between several panes thus constituting a rigid structure.

Figure 5 shows the variation of filtering on a filter.

Figure 6 shows a possible re-evaluation of the system.

 FIG. 7 represents a perspective view of FIG. 3.

EXAMPLES OF EMBODIMENTS:
-System equipped with a filter passing inside a double glazing (FIGURE 3) and (Figure 6).

This embodiment is a double glazing sink (3) and (4), having a sun visor system passing between the two panes. The distance between the two panes (3) and (4? Is, for example 5 mm. The sun visor consists of soft filters (1) and (2) each having a thickness of 0.3 min, for example. The two ends of each filter are wound on two rollers ((5a), (6a)) and ((5b ), (6b)). The filters (1) and (2) circulate inside the double glazing. The filter (1) circulates in the direction of the arrow (for example) .This filter is blackened according to the law p x power. The other filter (2) flows in the opposite direction. It is blackened according to the same law. The filters are stretched so that they do not touch and do not rub against the windows. Four rubbers (9). (10 ) (11). (12) are arranged so that the filters do not touch the edge of the panes. The rollers ((5a). (6a)).

((5b). (6b)) rotate according to their axis thanks to a motor or a crank. They are hidden by two blocks of aluminum or wood, for example (7) and (8). This system therefore makes it possible to have an A brightness varying uniformly over the entire window.

 -System equipped with a rigid structure sun visor. The filters (1) and (2) are placed between three rigid surfaces (17> transparent (glass, plastic or other) (FIGURE 4A).

The thickness of these surfaces being sufficiently small (of the order of 3 mm) so as not to "weigh down" the device, they are intended to serve as a guide and to keep the filters in a correct position. In addition, they make it possible to create within the window on either side of the sun visor (18) and (14) FIGURE 4B a partial vacuum (thermal and sound insulation). The principle is illustrated FIGURE 4B. The filters (1) and (2) have a thickness of the order of a millimeter (maximum), therefore the assembly (rigid surface (17) and filters (1) and (2) has a thickness of less than 1 cm.

FIGURE 3B shows the use of this sun visor. It is a section of the window: the panes (3) and (4) are conventional panes. The pane (4), exterior, can be covered with '' a reflective film to avoid capturing heat.The assembly (15) consists of two films (1) and (2) and rigid surfaces (see FIGURE 4A). Thus thanks to the seals (16) the volumes (13) and (14) can be under a partial vacuum.

-Filter added to a window frame already in place.

Thanks to the rigid structure described above (see FIGURE 4A).

 there is the possibility of fitting a window already in place. The aperture of the sun visor is on the inside and its operating mode is identical to that described in example 2, the rigid structure (15) being placed in front of the window. in place. However it would be preferable for reasons of rCsîstance to opt for rigid surfaces thicker and solid because being directly accessible, they will be susceptible to knocks and alterations. Therefore the choice of a solid and thick glass would be desirable. separating the sun visor from the window is variable depending on the window frame to be fitted. In addition, depending on the type of window opening, various installation methods are to be expected.

-Use possible for ceilings, bays, glass doors, greenhouses, verandas and and any other system comprising windows.

Claims (10)

CLAIMS The device which is the subject of the present invention is a device making it possible to vary the transparency: that is to say a new type of sun visor. 1) device for varying the transparency, characterized in that it comprises two movable and parallel transparent filters, fixed at their ends on two rollers. 2) Device according to claim 1 characterized by the nature  filters that have varying transparency ranging from the  total transparency to total black. 3) Device according to claim 2 characterized by the nature of the variation of the filtering which is continuous and governed by a law of the exponential type where the law represents the percentage of light transmitted by the filter at a point, percentage which is constant over the width of the filter. 4) Device according to claims 1,2,3 characterized in that  that the two filters are identical. 5) Device according to claim 2 or 3 characterized in that  that each re has at one end a totally transparent area and at the other a totally dark area whose lengths are greater than the height of the window to be fitted. 6) Device according to any one of the claims characterized in that the superposition of the two filters in  opposite directions of variation ensures obscuration  uniform over the entire surface of the glass to be fitted. 7) Device according to one of any claims  characterized in that the filters are inside a  double glazing. 8) Device according to claim 1 characterized in that  the filters are activated by one or more motors. 9) Device according to one of any claims  characterized in that the two filters are placed between two  windows and separated by a third. 10) Windows, bay windows, verandas, greenhouses, ceilings, doors  glazed, characterized in that they include a sun visor  according to any of the preceding claims.