MXPA06008794A - Transparent window panel with a field of view that can be partially darkened and method of controlling a surface element that can be electrochromically lightened inside a transparent window panel - Google Patents

Abstract

The invention relates to a transparent window panel with a field of view that can be darkened on part of the surface thereof, by electrically controlling at least one functional element which is built into a composite material comprising several layers, the transmission of light being reversibly variable. The aforementioned functional element, which, in particular, takes the form of a solid electrochromic layer system, comprises at least one electrochromic functional layer which is enclosed between two surface electrodes. According to the invention, the surface electrodes (2E, 4) of the functional element (2) and the connectors thereof (12, 14, 16, 18, 19, 20) are adapted to one another and are disposed spatially in relation to one another such that the darkening process begins at one edge of the functional element and, under a remaining voltage applied between the surface electrodes (2E, 4), propagates continuously over the surface thereof until it has been completely and uniformly coloured. The invention also relates to a method of controlling one such functional element, which can preferably be used as an electrically-controlled sun visor for vehicle windscreens and similar.

Description

TRANSPARENT WINDOW GLASS WITH FIELD OF VISION THAT IT CAN BE DARKED AND METHOD TO CONTROL AN ELEMENT OF SURFACE THAT CAN BE ILLUMINATED ELECTROCROMICALLY INSIDE A TRANSPARENT WINDOW GLASS. The invention relates to transparent glazing with a field of view that can be partially obscured on a portion of its surface by electrically controlling at least one functional element incorporated in a multi-layer composite, glaze whose • Transmission of light can be varied in a reversible manner, in whose portion of the functional element, in particular. in the form of an electrochromic multiple layer solid state system, it comprises at least one electrochromic functional layer enclosed between two surface electrodes, and a method for controlling a surface element that can be electrochromically bleached in the transparent glaze.

WO 93/04885 A1 and US 4 832 468 describe vehicle windshields, whose upper edge band is equipped with electrochromic elements whose transparency can be varied in an adjustable manner. Consequently, mechanical sun shields are superfluous or, at least, supplemented. The edge band can be provided over its width with separately controllable elements, so that it does not have to be always obscured over its total area.

WO 03/007065 A1 discloses a request for a multi-layer electrochromic solid-state system, especially for the aforementioned purpose. US 6 277 523 Bl describes the chemical and physical principles of those multi-layer electrochromic solid-state systems.

US 5 523 877 describes in great detail several possible ways of varying the transmission of the transparent laminated glaze by means of multi-layer electrochromic elements. The document also indicates that the electrochromic elements can act on roofs, windshields or in the "shading bands" of vehicles. However, in each case it is necessary to accept that the respective element can always be electrocromically obscured over its entire area.

Finally, document DE 100 46 103 A1 describes transparent glazing with an attachment that allows the reversible dimming of only certain sectors through electrochromic means, whose location on the surface of the glaze is determined by a sensor-induced control. However, that document does not give any technical detail about the production of that glaze. In particular, it is not clear how electrochromic layers or elements should be deposited on the glaze.

The basic problem of the invention is how to provide another transparent glaze in which only a portion of the visual field is equipped with an electrochromic element, and to provide a method, which allows to control this electrochromic element.

According to the invention, this problem is solved by the fact that the surface electrodes of the functional element and its cables are connected to one another and spatially separated from each other in such a way that their obscuration starts at one edge of the other. functional element and, with a remaining voltage applied between the surface electrodes, it propagates continuously over the area of the element until it is completely and uniformly colored with respect to the glaze and by the fact that the surface electrodes are produced with different elements of resistance to the surface, from which the propagation of a potential on the surface of these surface electrodes proceeds at different ranges for any voltage level, and because an effective electric potential is introduced into one of the surface electrodes with relationship to the other surface electrode, forcing the electrochromic change of the color on one side of the electrochromic element of the surface, • in order to control an • propagation direction of the color change of the electrochromic element of the surface.

The claims respectively dependent on the independent claim have the advantageous representations of the invention.

Through the design, arrangement and local electrical control of the electrodes of the multi-layer electrochromic solid-state system (hereinafter referred to as the EC system), it is possible, according to the invention, that the color change of the system (the change being totally reversible) has a rolling effect, that is, the color change of the system or, depending on the case, of the EC element, starts at one of its edges and then propagates relatively quickly (depending on the applied electrical voltage) as far as the opposite edge. With the experimental specimen, the time required for a complete color change on an EC element of 15 c in width is less than 30 seconds.

A particularly preferable application of this effect is to combine it with the vehicle windscreens in the configuration explained in the introduction. Here, it is possible to propagate the darkening in the form of unwinding starting from the upper edge of the windshield downwards, to the opposite edge of the EC system located in the field of vision of the glaze.

Of course, these applications can be contemplated not only for land vehicles, but also for the windows of aircraft, spacecraft, etc., ships and especially vehicles, and also obviously, in general, but not uniquely, for the front windows or windshield, but also for the side windows or the rear windows. In addition, other applications are conceivable, particularly in the construction sector.

According to an advantageous embodiment of the invention, the illumination propagates in the opposite direction of the darkening, namely from the bottom up, so that an unwinding effect appears again. Apart from the aesthetic aspect of that representation, this dynamic form in which the color change operations take place could be more acceptable to the occupants of the vehicle than a sudden darkening over the entire area, which. it must be accepted when the known EC elements are used.

Since the color change operations propagate continuously over the area of the entire element, while applying the voltage supplied, it also turns out to be superior to the known subdivision of the EC elements in individual bands that are controlled separately. Apart from this aspect, the arrangements of other electrodes in the region of the surface, which is covered by the electrochromic layer, and the corresponding subdivision of this layer also allow, with this technology, to obtain a subdivision in several fields that are controlled separately, it being then possible for each of these fields to perform, if required, the aforementioned unwinding effect.

With a particular preference, the present invention can be used with multi-layer solid state EC systems operating on the basis of a reversible dispersion of the cations in an electrochromic functional layer. The differences in transmission and color are the external signals of the different oxidation states of the electrochromic material (containing, for example, tungsten oxide).

The activation of the coloration and the discoloration, respectively, of the element EC, can be controlled manually by means of the appropriate switching means. As a variant, or in combination with a manual control for switching operations, it is also possible for the control to be through sensors. In this case, one or more sensors (for example photodiodes or similar photosensitive converters) can be provided in the window glass, which itself is equipped with the EC element, or locally, separated from the latter. In DE 199 25 335 A1 an example of a possible optimized control has been described.

In any case, an electronic control device or the like may be provided to receive the manual adjustment or the control signals, and / or the sensors, and to deliver the corresponding voltage supplies to the electrodes of the EC element, i.e., at least a voltage to color it and another voltage to discolor it, these two voltages being delivered to the cable of the common electrode of the surface (or to the "upper" electrode of the surface in view of the illustrated example) and to one or other of the two cables, respectively, for the other surface electrode (or "bottom" electrode of the surface).

Other details and advantages of the subject matter of the invention will emerge from the drawings of an example of illustration and from the detailed description that follows.

In these simplified representations, which do not have a particular scale: Figure 1 is a view of a vehicle windshield, in which the arrangement of an EC element and its electrodes is shown schematically; and - Figure 2 shows a cross-section through the glaze of Figure 1 in the region of the EC element, along the line (II-II).

As shown in Figure 1, on a windshield (1) formed by laminated glaze with a substantially trapezoidal profile, an element EC (2), also of trapezoidal profile, is located in the region of the short parallel side of the trapezoid on the face of the glaze that is located inside the composite. In the mounted position of the windscreen, it extends along the upper edge of the glaze with a height of about 15 to 20 cm. Unlike conventional sun shields, the element EC (2) completely covers this band, even when its edges are defined at short distances from the upper sides of the glaze (1).

An opaque region of the edge is formed as a peripheral frame (3) on one face of the glaze located inside the compound, a region which, as is well known, serves to cover the view, on the one hand, of the windshield joint (1) in the body of the vehicle and, on the other hand, the external electrical cables for the EC element. As can be seen in Figure 2, the frame (3) and the element EC (2) are placed on different faces or fall on different planes of the glaze inside the latter.

In vertical projection on the surface of the glaze, the frame (3) covers the lateral edges and the upper edge of the element EC (2). However, the lower order of this element EC falls into the field of vision of the glaze (1), surrounded by the frame (3). Unlike the simplified representation of the pattern, the transition between the opaque frame and the viewing frame is smoothed by a dot grid pattern or the like, with the edges of the EC element (2) preferably in the completely opaque region.

In the region of the surface of the EC element, the transmission of light is, in the deactivated state, slightly smaller (approximately 60%) than in the field of view of the windshield (where it must be at least 75% in accordance with a European standard). This is indicated by the light gray shading of this surface. The lower edge of the EC element (2) is positioned in such a way that the main field of vision of the windshield (1), defined by the respective authorization provisions, is not affected.

It is evident that it is possible, if necessary, to provide cavities on the surface or the edge of the EC element, for example when it is necessary to place, behind the electrochromic region to be colored, the sensors, a camera or the like, again with infrared base, the transmission paths from which they must pass through the glaze (1) and could be affected by the EC element and / or by the layers of the latter. These cavities can advantageously be placed below a support of the interior rearview mirror attached to the internal face of the glaze, which support can also contain the sensors and similar devices mentioned above.

In the present illustrative example, the surface of the glaze is covered with a transparent electrically conductive cover (4) which serves as a surface electrode near the substrate for the element EC (2). For the EC element (2) to operate, it should be sufficient, however, to provide in principle the cover (4) only on the surface covered with the EC element, but with the cover extending slightly on the edge side.

However, the complete cover is easier to achieve because then it is possible to dispense with the partial masking of the substrate. Furthermore, the complete coverage of the surface has the advantage that it could also, when provided with the appropriate cables (in a manner known per se), be used to heat the laminated glaze.

Although it is possible to deposit the cover before cutting the glaze, in the present case it is deposited, such as the element EC (2) itself, on the finished glaze, which optionally can be curved. The cover may include a layer of indium tin oxide (ITO); however, other multi-layer conductive systems, possibly composed of more than one clear layer, which have been described several times in the prior art, can be used as the surface electrode. The cover can also have thermal insulation properties (by reflection of infrared radiation).

Preferably, these covers are deposited in a manner known per se, through magnetically enhanced electronic deposition (electronic deposition / PVD process) directly on the surface of the glaze. However, it is also possible that they are deposited by the CVD procedures.

Directly deposited on the layer (4) of the electrode is a multi-layer electrochromic system (possibly comprising several layers) according to the prior art mentioned in the introduction, which forms the element EC (2). Again deposited on the electrochromic layer is another transparent surface electrode to form a remote return electrode from the substrate. The multiple layer structure of the EC element will be explained later in greater detail with respect to Figure 2. In all cases, its. Layers can be deposited economically by electronic deposit in industrial scale facilities. ' For the element 'EC to be electrically controlled in the manner defined within the present invention, several electric cables are required. The cover (4) and the element EC (2) are divided by a first separation line (5) and by a second separation line (7) in a central field and two relatively narrow bands (6 and 8). These bands extend parallel to the two short sides (oblique) of the trapezoid of the glaze and are located on the surface covered by the frame (3).

Provided on the right side, along the right edge of the glaze (1), there is another separation line (9), which separates another narrow band (10) from the cover (4) of the side band (8). Finally, again at the right edge of the glaze (1), there is a short separation line (11) separating the bands (10 and 8) from the cover.

All the separation lines mentioned represent the complete electrical separation of the fields. divided, or alternatively of the divided regions of the surface. Preferably, they are drawn only after • of the complete construction of the EC element (preferably being traced by laser beam machining). However, they can also be plotted first on the cover - (4) and subsequently on the EC element (2). There can be no current flow through these separation lines within the subdivided covers, for • avoid short circuits.

Provided in the region of the upper edge of the frame (3), between the lines (5 and 7) of separation, parallel to the upper side of the glaze (1), there is an elongated connection band 812) connected in an electrically conductive manner with the cover (4). It includes an external cable (13) that is shown in a simplified way in the form of a cable. The entire field of the cover (4) located between the lines (5 and 7) of separation can be supplied. electrically through the cable, in the form of a surface electrode for the EC element (2).

The element EC (2) also includes a remote electrode of the substrate, with the same surface dimensions as the EC element itself (therefore, corresponding to the gray area in Figure 1), this electrode being discussed in greater detail in relation to the Figure 2. This electrode. it may not have a direct electrically conductive connection with the cover (4). However, since the element EC (2) does not extend straight to the bottom side of the glaze (1), it is sensible to place the contacts designed to connect to the remote electrode of the substrate laterally with respect to the cable for the cover (4). ). This therefore avoids the crossing and isolation problems that could arise with an arrangement of external cables for the remote electrode of the substrate also along the upper edge of the glaze (1). Finally, it is not possible, for technical reasons, to place the connecting band (12) below the EC element (2).

Therefore, another connection band (14) with an external cable (15) is placed in the band (6) on the left side, while it is still electrically isolated from the main field of the cover (4) and the band ( 12) connection through the separation line (5). Correspondingly, a third connection band (16), with an external cable (17), is placed on the band (8) on the right side. These cables mentioned above have a low ohmic resistance compared to the cover (4).

When it is in a state mounted on the body of a vehicle; the edges of the windshield are covered with an internal cover, in such a way that the regions are, even from the inside, hidden from view.

The two connecting bands (14 and 16) are electrically connected to one another by very thin metal wires (18). These metal wires (18) are located, unlike the connecting bands, over a large proportion of their length, in the field of view of the windshield. They pass through the surface covered with the EC element (2) and are . connected in an electrically conductive manner with the remote electrode of the substrate of the EC element.

Therefore, the wires form "closing" connections for electrically connecting the remote electrode of the substrate with the connecting bands (14 and 16). It should be explicitly emphasized that two connection bands of the same polarity must not necessarily be provided on each side of the EC element (2), instead it is also possible, in principle, to place the wires from a single connection band, example with the free ends or forming a circuit, insofar as a - Uniform color change of the EC element (2) with the desired unwinding effect.

These arrangements of the wires are of course known in electrically heated laminated windows that use heating wire arrays. The individual wires are so thin that they are virtually imperceptible to the naked eye, and are also covered by the light coloration of the EC element (2). Usually the wires are made of tungsten and can withstand a high mechanical load, so that they have the necessary robustness to be placed by a machine, despite the minimum diameter of the wires.

Finally, another electric cable (19) is provided in the region of the band (10) of the right outer side, whose cable (19) is first parallel to the right side of the glaze and is taken below the line (11) separation in the field of vision of the glaze, in the form of another thin wire (20) parallel to the bottom side of the element EC, this cable being connected, as a direct conductor electrical link, with the cover (4). The cable (19) and the wire (20) are electrically isolated from the connection band (16) by the lines (9 and 11) of separation. However, they are connected in an electrically conductive manner with the connection band (12) via the cover (4) and are therefore, in principle, at the same electrical potential as the latter.

Although the cable (19) has been shown here again as a line, however it can also be made in the form of a connecting band in the region of the opaque frame if the available width is sufficient.

For the sake of clarity, the mutual distances between the bottom edge of the element EC, the line of separation (11) and the horizontal portion of the cable (19) have been exaggerated. In . the mass production glaze, the horizontal portion (20) of the cable (19) will be carried as close as possible to the bottom side of the element EC 82).

At this point it should be emphasized that, if the requirement is that the supply to the surface of the voltages and of the operating currents for the -element EC within the two surface electrodes be as uniform as possible, more than two wires can be provided. (18) and more than one wire (20).

If, as mentioned here, the cover (4) completely covers the whole surface of the glaze, the wire rope (19/20) - or instead of this also a band of wider connection similar to the band (12) connection-can in principle be placed on the bottom side of the glaze (1), again on the surface covered by the frame (3) outside the field of vision of the glaze (1), as indicated by the dotted lines ( 20 ') of Figure 1. However, the behavior of the response of the EC element (2) during illumination can then be delayed more strongly in relation to the application of the switching voltages, than in the case of the representation that is indicates with solid lines, because, by the negligible resistance - on the surface of the cover (4), even when the potential is applied to the cover, the supplied voltage can only slowly increase through the EC layer. The Figure shows that, near the upper right corner of the laminated glaze (1), the three electric cables (13, 17 and 19) are grouped together very closely, while the electric cable (15) is placed in the corner upper left. Of course, it is possible that cables with the same polarity (13 and 15) are connected. directly together, by providing, preferably, a line for direct connection between them, parallel to the connecting band (12), in the region of the surface or in the side band covered with the opaque frame (3). However, this line must be electrically isolated from the region of the surface of the cover (4) which is located between the lateral bands (6 and 8). For example, for this purpose a flat cable could be provided, including (at least) an electrically conductive path in a non-conductive (plastic) support. All in all, it is necessary to put together, in one place, all the external cables for the element EC (and possibly for other functional electrical elements of the glaze (1)), and put them in contact with the electric circuit of the vehicle or with a electronic control unit, using, when necessary, a multiple connector or a multiple cable welded with solder.

The internal structure of the composite windshield (1) will now be explained with reference to Figure 2, which shows the windshield seen in cross section along the section line (II-II) of Figure 1. The identical components are They have been given the same numerical references as in Figure 1. This Figure shows two rigid individual glasses (1) (made of glass or plastic) and a layer of adhesive (21) electrically insulating and visually transparent, which joins them together adhesively in the usual way. This layer is divided horizontally by a dotted line, as an indication that it is in fact substantially thicker than the element EC (2) or that the individual layers of the latter. The material of the adhesive layer must be chosen according to its compatibility with the production of the layers of the element EC (2).

The corresponding references are found in the literature mentioned in the introduction. Due to their strong hygroscopic properties, the usual adhesive films, made of PVB, are the least considered here. Currently, thermoplastic polyurethane adhesive films are preferable, although other materials can also be contemplated. The functional layer of the EC element (2) must have a defined water content, which can not be "removed from it through the material of the film.

Mounted as a vehicle windshield, the upper glass of Figure 2 is placed on the outside and the bottom glass is turned towards the passenger compartment inside the vehicle. This figure shows, on the right edge, the position of the frame (3) on the surface of the upper glass located inside the composite (in the language of the experts, on the face (2) of the laminated glaze). On the inner side of the lower glass facing it (face (3)), the cover (4) is directly deposited as the electrode of the bottom of the element EC (2). To further reduce the aforementioned risk of dehydration of the EC element, the adhesive layer (21) of the laminated glaze can be sealed with an outer peripheral seal (22) (for example with a butyl sealant).

At the left edge of the section is a layer (2F) functional cover (4), and above this functional layer is another surface electrode (2E) for the element (2) EC. This functional layer and this surface electrode extend to the right beyond the separation line (7), but end, however, before the separation line (9), this being indicated with thick vertical lines. The functional layer (2F) 'is shown here in a simplified manner in the form of a single layer. In fact, it is composed of several individual layers, but it is not necessary to describe them here in detail, because they must be considered as known.

It can be seen that the separation line (7) passes through all the layers of the element 82) EC, namely the surface electrode (2E), the functional layer (2F) and the cover (4), and the electrically separates from the side band (8). However, it would also be possible to interrupt the cover (4) and the layers of the element (2) EC with a lateral deviation. Then a short circuit would also not be acceptable via these separation lines, because the functional layer (2F) of the EC element shows anisotropic conductivity, ie. it has much greater resistance on its surface than the surface normal (i.e., directly between the surface electrodes (4 and 2E)).

Only the wire (18) goes beyond this separation line, and therefore represents the electrical conductive connection between the surface electrode (2E) and the connection band (16) (if several wires (18) are provided, as in Figure 1, each of them must extend, of course, beyond the separation line). The direct connection of the lateral band (8), or of the connecting band (16), respectively, to the central region of the surface - surrounded by the frame (3) - of the cover (4), is prevented with the line (7) of separation. It is admitted that it could be envisioned to provide the separation line (7) (and the corresponding separation line (5) on the other side) exactly next to the lateral end of the EC element, however this is more expensive than the representation that Here it is shown and does not provide a technical / electrical advantage.

The wire (18) also resolves the difference in height, inevitable in the present configuration of this glazing unit, between the respective connection bands (16 and 14) (which are relatively thicker) and the element (2) EC more thin.

To produce electrical cables, the film (21) Adhesive is equipped before the assembly of the individual layers of the laminate. On its face placed on the element (2) EC in the assembly position, it loads in particular the bands (12, 14, 16), the wires (18, 19 and 20) and, when necessary, also the cables (13). , 15 and 17) outside to where they are introduced into the composite, each time in the positions shown in Figure 1. It is also possible to provide certain guiding means on the back of this film, for example, the direct connection which is mentioned above between the connecting bands (14 and 16), possibly also the line (19).

The wires (18) can be connected in an electrically conductive manner to the solder connection bands (14 and 16), or alternatively with the incorporation of solder into a layer; this is also valid for any necessary connection between lines (19 and 20) that occur separately. All the parts of the connection are. finally mechanically coupled in a reliable and permanent manner, and put into electrical contact after the adhesive layer (Zl) and the second individual glass of the composite have been placed in position, by the action of heat and pressure (for example in an autoclave). In this case, the connecting band (12) and the wire (20) are again in sufficiently close contact with the cover (4), and the wires 818) in contact with the electrode (2E).

If it is necessary to prevent the cover (4) from corroding starting from the edge of the glaze, the cover (4) will end well before the outer side of the glaze. If it has been temporarily deposited on the entire surface, as already mentioned above, it can again be removed along the sides of the glaze using methods known per se. In the case of an ITO cover, cleaning the edges is not absolutely necessary. However, in this case of inner sealing with the seal (22) is also necessary. Similarly, the separation lines (5 and 7) already provide a degree of protection against penetration of corrosion.

Below will be explained how the EC element and its cables are used. In general, to operate the ES element, it is necessary to provide an electronic control unit (not shown), for example of the type described in DE 199 25 335 A1, which can provide, at various outputs, voltage levels positive and negative very defined. If necessary, this control unit is also connected to the sensors which can automatically darken the EC element, for example when there is a risk that the driver will be blinded by the sun descending the horizon.

During the darkening process, the band (12) Connection is used as a positive electrode to apply a positive voltage to the cover (4). Since it has a low ohmic resistance compared to the latter, its electrical potential is communicated along its entire length to the cover (4). During the application of the voltage, this voltage can increase only relatively slowly on the surface of the cover (4) (which has, for example, a resistance of about 6-7 ohms per unit area).

In the case of the example, the surface electrode (2E) has also been deposited integrally with a surface resistance of about 60-70 ohms per unit area, which is therefore much greater than the surface strength of the surface. the cover (4). This can be influenced and controlled ', during the deposition of the cover by electronic deposit, adjusting the working parameters and through the composition of the material of this electrode layer. - The functional layer (2F) of anisotropic conductivity has a very low electrical resistance perpendicular to the surface electrodes (2E and 4).

Below are the relationships between the resistors: R2F «R4 < R2E > where R represents each time the ohmic resistance. As a result, we can count on an almost immediate exchange of charges in the 'moment when there is' a sufficiently high voltage (the potential difference across the functional layer (2F)) in any region between the electrodes (4 • and 2E). This voltage (indicated on the left edge with an arrow and with a (ü) between the cover (4) and the surface electrode (2F) causes the functional layer (2F) of the EC to be obscured by the exchange of load.

In a particularly advantageous manner, the voltage is chosen in such a way that, combined with the careful determination of the resistance of the layers of the surface electrodes, the functional layer begins to darken at its slightly narrower upper edge, so that it is observed the unwinding effect,. which propagates in a few seconds as far as to the bottom edge of the EC element.

The substantial difference in the conductivity of the two surface electrodes (2E and 4) is considered as the initiator of the desired unwinding effect according to the invention. For the same voltage value, a sufficient supply of applied voltage will propagate more rapidly on the surface of the cover (4) than on the surface of the surface electrode (2E).

Intellectually, this can be represented as the advance of a voltage front or a changing high load current (which transports and disperses the cations) that flows briefly in the functional layer, starting from the point of application of the driving voltage to the extreme of the surface electrode.

However, in the final static state a uniform coloration of the EC element over the entire surface is achieved. This lasts as long as the supply voltage in the functional layer (2F) is maintained at a constant level or is at least pulsed. The discoloration (reverse ion exchange) of the functional layer (2F) takes place with a relative delay, so that it is sufficient to have a pulsed voltage supply.

In an experimental glazing unit with the EC element, a voltage of 1.55 V (DC voltage) was applied for the darkening. This resulted in the darkening, in less than 30 seconds, of an EC element with a height of about 15 cm.

If there is no voltage between the electrodes (4 and 2E) of surface (0 V), the element (2) EC will light up again little by little, returning to its natural key essentially transparent, without other measures, due to the fact that the electric charges that contribute to the darkening resume their initial state again. The method for operating the element (2) EC substantially corresponds to that of an accumulator.

However, it is possible, by means of the additional electrode formed by the cable (19/20) (which could also, as mentioned above, be located at the bottom edge of the glaze (1)), causing the illumination to unravel from the bottom edge of the element (2) EC, therefore in the opposite direction of the darkening, having the effect of a roller that is winding.

For this purpose, it is necessary, after the voltage in the connection band (12) has been cut off, • apply a reverse voltage in relation to the dimming voltage (U) between the portion (20) of the wire (and the cover (4)) and the surface electrode (2E), which does not necessarily have the same value as the voltage of darkening.

Then the unwinding effect appears again, due to the difference in the resistance of the electrode surface of the layer (4). and the electrode (2E) of the upper layer. Its highest resistance determines at what speed the current flows, to extract or remove the cations from the functional layer again, the resistance of the functional layer (2F) being, as mentioned, negligible and even lower during the discharge than during the dispersion of the cations.

Similarly, the portion (20) of the third cable has an ohmic resistance that is really small compared to the surface electrodes (4 and 2E), so that it is possible to observe here the same behavior as during the supply through the band (12) connection.

Of course, it would also be possible to reverse the "direction of movement" of the unwinding effect, that is, to cause the dimming to start in the field of view of the window glaze (if the dimming voltage was applied via cable 19 / 20), or cause the dimming to start simultaneously from two opposite sides of the EC element via the simultaneous supply from the cables (12 and 19/20).

If it is desired to produce several fields controlled separately with this EC element, these must be separated from each other with horizontal separation lines, and each one of its own electrodes must be provided "off".

Claims (16)

RE IV INDI CAC I ONES

1. Transparent glazing with a field of view that can be obscured on a portion of its electrically controlled surface at least one functional element incorporated in a multi-layered composite, whose light transmission can be inversely varied, portion in which the functional element, in particular in the form of a multi-layer electrochromic solid-state system, comprises at least one electrochromic functional layer enclosed between two surface electrodes, characterized in that the surface electrodes of the functional element and its cables are coupled one with the other and are spatially separated from each other so that their dimming starts at one edge of the functional element and, with a remaining voltage applied between the surface electrodes, propagates continuously over the surface of the element until it is completely colored uniformly. Transparent glazing according to claim 1, characterized in that at least one of the surface electrodes is connected to at least one conductor of the connection having a low ohmic resistance, which conductor is parallel to, and is located near, a lateral edge of the functional element. 3. Transparent glazing according to claim 1 or 2, characterized in that at least one of the electrodes of . The surface is equipped with two conductors of the low ohmic resistance connection, which are placed on each side of the functional element and can be subjected to electrical potentials independently of one another through suitable external cables. 4. Transparent glazing according to any of the preceding claims, characterized in that the functional element extends along one side of the glaze and, from this side, within the field of view of the glaze, field of view whose obscuration initiates in the region on that side. Transparent glazing according to claims 3 and 4, characterized in that one of the conductors of the connection is placed near the side of the glaze and the other is placed on the other side of the functional element, in the region falling between the border located - in the field of vision and the opposite side of the glaze. Transparent glazing according to claim 5, characterized in that a conductor of the connection, which is in the field of view of the glaze, has the shape of at least one thin metal wire. - 7. Transparent glazing according to any of the preceding claims, characterized in that the functional element extends from a first side of the glaze and then between two mutually opposite sides of the glaze and that are angularly connected with this side, glaze in which one of its surface electrodes is brought into electrical contact towards the outside from at least one. surface that extends along opposite sides. 8. Transparent glazing according to claim 7, characterized in that the remote surface electrode of the substrate is electrically connected to at least one cable that rests on the edge of the glaze, 1 by means of al. minus a thin metal wire that extends over the surface of the functional element that falls into the field of view of the glaze. 9. Transparent glaze according to any of the preceding claims, characterized in that the surface electrode near the substrate has the form of a substantially complete cover of the glaze, in which the functional element is formed only on a portion of this cover, such so that the side strips not covered by the functional element are formed on at least two sides of the glaze forming an angle therebetween, in which the lateral strips of the surface electrode are electrically isolated from one another and in that on each side of the side bands a connection band is provided, one of which is electrically connected to the surface electrode near the substrate and the other of which is electrically connected. with the surface electrode distant from the substrate of the functional element. Transparent glazing according to any of the preceding claims, characterized in that the two surface electrodes are produced with different surface resistors. 11. Transparent glaze according to claim 10, characterized in that the surface electrode near the substrate has a surface resistance lower than that of the surface electrode distant from the substrate. 1

2. Transparent glazing according to claim 10 or 11, characterized in that the surface resistance of the surface electrode near the. substrate falls within the range of from 0.01 to 100 ohms per unit area, preferably from 2 to 10 ohms per unit area, and more preferably from about 6-7 ohms per unit area, and in which the surface strength of the Surface electrode far from the substrate is about 10 times these values. Transparent glazing according to any one of the preceding claims, characterized in that an opaque edge frame extends over at least a portion of its perimeter along the edge of the latter and in which the electric cables for the surface electrodes are placed on the surface of the edge frame. 14. Use of transparent glaze according to any of the preceding claims as for breezes for a vehicle, wherein the multi-layer electrochromic solid-state system is placed, as an electrically controllable shield for the sun, in a region of the upper edge in the been mounted. 15. Method for controlling a functional element in the form of a total solid state electrochromic surface element in a transparent glazing unit, a solid solid state element including a bifunctional layer that can be reversibly electrochromically bleached, being inserted between two surface electrodes, characterized in that the surface electrodes are produced with different surface resistors from which the increase in the voltage supplied at the surface of these surface electrodes proceeds at different ranges for any voltage level, and in that an effective electric potential is introduced into one of the surface electrodes in relation to the other surface electrode, forcing the electrochromic color change on one side of the electrochromic surface element, - in order to control a propagation direction of the color change of the electrochromic surface element. 16. Method according to claim 15, characterized in that at least one supply cable is provided for the electrical potentials causing the electrochromic color change in at least one of the surface electrodes on either side of the state surface element solid total. 0 17 '. Method according to claim 15 or 16, applied . via a first supply cable for the surface electrode relative to the other surface electrode, to induce a coloration in a predetermined direction of the propagation of the color change, and in which a second effective potential, or reverse polarity, is applied via a second supply cable for the surface electrode relative to the other surface element, to produce discoloration in a predetermined direction of the propagation of the color change. Method according to any of the preceding method claims, in an application for controlling an electrochromic functional element incorporated as a shield for the sun in the windshield of a vehicle.