Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/10009—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets
  • B32B17/10036—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the number, the constitution or treatment of glass sheets comprising two outer glass sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B17/00—Layered products essentially comprising sheet glass, or glass, slag, or like fibres
  • B32B17/06—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material
  • B32B17/10—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin
  • B32B17/10005—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing
  • B32B17/1055—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer
  • B32B17/10761—Layered products essentially comprising sheet glass, or glass, slag, or like fibres comprising glass as the main or only constituent of a layer, next to another layer of a specific material of synthetic resin laminated safety glass or glazing characterized by the resin layer, i.e. interlayer containing vinyl acetal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
  • B60S1/00—Cleaning of vehicles
  • B60S1/02—Cleaning windscreens, windows or optical devices
  • B60S1/04—Wipers or the like, e.g. scrapers
  • B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
  • B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
  • B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
  • B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
  • B60S1/00—Cleaning of vehicles
  • B60S1/02—Cleaning windscreens, windows or optical devices
  • B60S1/04—Wipers or the like, e.g. scrapers
  • B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
  • B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
  • B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
  • B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
  • B60S1/0825—Capacitive rain sensor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60S—SERVICING, CLEANING, REPAIRING, SUPPORTING, LIFTING, OR MANOEUVRING OF VEHICLES, NOT OTHERWISE PROVIDED FOR
  • B60S1/00—Cleaning of vehicles
  • B60S1/02—Cleaning windscreens, windows or optical devices
  • B60S1/04—Wipers or the like, e.g. scrapers
  • B60S1/06—Wipers or the like, e.g. scrapers characterised by the drive
  • B60S1/08—Wipers or the like, e.g. scrapers characterised by the drive electrically driven
  • B60S1/0818—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like
  • B60S1/0822—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means
  • B60S1/0874—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield
  • B60S1/0877—Wipers or the like, e.g. scrapers characterised by the drive electrically driven including control systems responsive to external conditions, e.g. by detection of moisture, dirt or the like characterized by the arrangement or type of detection means characterized by the position of the sensor on the windshield at least part of the sensor being positioned between layers of the windshield

Definitions

• the present invention relates to glazings comprising a rain sensor, and in particular those used on motor vehicles.
• sensors to detect the presence of water on a glazing unit, for example to control an operation such as the starting of wipers for motor vehicles is usual.
• the marketed sensors are of the type using the alteration of a light signal on the path of which are the drops of water to be detected.
• the sensor comprises a transmitter and a receiver of the light signal constituted for example by a reflected ray.
• the sensors operating on these optical signals when used in particular on automotive windows, have the disadvantage of leading to the presence on the glazing of non-transparent elements. Even miniaturized, the sensor covers about ten square centimeters. To minimize annoyance to the windshields, the sensor is usually hidden behind the interior rearview mirror. Even in this arrangement, the presence of the sensor on the windshield remains unsightly, at least seen from the outside.
• Another type of sensor has been proposed previously, which implements a device in which the signal is generated by a variation of capacity.
• An electrode assembly is disposed on the glazing.
• This variation constitutes the signal generated by the sensor.
• Provisions have been proposed, wherein the electrodes constituting the capacitive sensor are located on the face of the glazing not exposed to rain. In these embodiments the sensors usually have insufficient sensitivity. They have the further disadvantage of generating erroneous signals when the glazing is the object of fogging on the face carrying the sensor.
• the electrodes between the glass sheets in the laminated glazings using, to form these electrodes, a conductive layer coating this glazing and intended in particular to reduce the transmission of infrared radiation.
• layers having this property are conductive layers that are formed of conductive oxides such as ITO I 1 ( “indium-tin oxide”) or, more frequently a set of layers including the reflecting infrared is a thin metal layer, most often silver.
• the advantage of the layers in question is that they retain a very large transmission of the visible light spectrum.
• laminated glazing comprising these layers offer as the regulation requires for automotive windshields, a light transmission that is not less than 75%.
• Capacitive sensors of the latter type like those of the previous types, have not experienced any industrial operation to date.
• the inventors proposed capacitive rain sensors that are compatible with all laminated glazing, without these windows have a layer limiting the transmission of infrared rays.
• these sensors are introduced into a laminated glazing in the form of an insert disposed between the sheets of the glazing.
• the insert comprises a substantially transparent support sheet on which the conductive circuit constituting the sensor is disposed.
• This conductive circuit is advantageously in the form of a conductive thin film itself essentially transparent or a very thin metal film retaining a certain transparency.
• the glazing in question is usually made of two sheets of glass assembled by means of an interlayer sheet of synthetic material such as polyvinyl butyral (PVB), an ethylene vinyl acetate (EVA) resin or any conventional interlayer for this purpose. type of assembly.
• PVB polyvinyl butyral
• EVA ethylene vinyl acetate
• it can also be so-called "bilayer" glazing which comprise a sheet of glass associated with a sheet of a plastic material, in particular polyurethane, a material which simultaneously offers the plasticity ensuring the resistance against the eviction of the passengers in case accident, and sufficient surface quality to resist scratching.
• the capacitive sensor is inserted in the glazing. In other words, it is not on the face of the glazing exposed to rain, and is not in contact with the atmosphere located on the other side of the glazing. It is at least isolated from this atmosphere by a non-conductive protective film of electricity.
• the introduction into the glazing is advantageously carried out during the lamination operation.
• the sensor and the elements that constitute it are then subjected to relatively moderate operating conditions compared to those corresponding to the forming of bending and tempering glass sheets.
• the assembly of the laminated glazing is usually performed under conditions including temperature of the order of 150 0 C which do not affect the constituent elements of the sensors.
• the presence of the inserted element changes the quality of the assembly. This element whether the conductive circuit or the sheet constituting the support of this circuit does not have most often properties promoting adhesion to glass sheets.
• Another embodiment involves inserting the sensor between a glass sheet and the interlayer using an adhesive on the face in contact with the glass sheet. Multiplying the introduced elements makes the assembly more delicate and more expensive, and significantly increases the risk of defective parts.
• the invention proposes to develop capacitive sensors in the form of inserts, which are of simplified manufacture and implementation.
• a first characteristic of the invention is to propose capacitive detectors in the form of an insert comprising a support sheet and a circuit constituting the detector, the assembly being substantially transparent, the insert in question being provided on at least one of its faces. an adhesive film selected from those capable of good adhesion to the glass.
• the introduction is advantageously further simplified by using a pressure-sensitive adhesive. Fixing on the glass sheet is thus obtained instantly and avoids any displacement or subsequent deformation of this assembly that its small thickness makes mechanically fragile.
• the supports on which the circuits forming the rain sensor are constituted are necessarily very thin to remain transparent on the one hand, and secondly to be introduced into the laminated assemblies without substantially modifying the structure of the glazing.
• the sheets for example PET, which are advantageously used for support, have for example a thickness of the order of twenty microns. But at these thicknesses if the mechanical properties are sufficient in terms of tensile strength in particular, the sheets are difficult to handle because of their lack of rigidity.
• the semi-rigid sheet is chosen from a material which limits the adhesion so that during its separation it practically does not cause the adhesive in question.
• the inserts according to the invention necessarily include a strong adhesive to fix the insert to the glass sheet.
• the adhesive is on the backing sheet or on the material constituting the ⁇
• the adhesion of the side facing the interlayer is normally easier to achieve because of the nature of the interlayer.
• the materials constituting the capacitive circuit generally adhere sufficiently to the interlayer, particularly when it is made of a sheet of PVB.
• Some substrates such as PET sheets, offer only limited adhesion with traditional interleaves.
• the adhesion is reinforced either by means of a second adhesive or by modifying the surface state of the support in order to improve its adhesion characteristics.
• a suitable modification consists for example of a "flame" or a plasma discharge activation treatment.
• the adhesive intended to fix the insert on the glass sheet is advantageously protected by a film whatever the face of the coated insert, (that bearing the circuit or the other face), it is also preferred to protect the second face by a second protective film removed at the time of use, that is to say during assembly in the glazing.
• This second protective film is all the more useful when the capacitive circuit is not turned on the side of the glass and therefore is not covered by the adhesive and the first protective film.
• the second protective film has a preferably low adhesive coating and preferably also such that it remains on the protective film in question when the latter is removed during the introduction of the insert.
• the face in contact with the interlayer is also advantageously coated with an adhesive when the interlayer sheet does not present itself.
• a sufficiently "sticky” character This is particularly the case for some media like PET sheets with what is most commonly used as an interlayer sheet namely PVB.
• the adhesive used can also maintain the second protective film but is not removed with the latter.
• the manufacture of the inserts according to the invention can also benefit from certain simplifications because of their structure.
• the simplification concerns in particular the mode of production of the conductive circuit forming the capacitive detector.
• the elements constituting the circuit, electrodes and supply conductors are advantageously formed in a layer or set of thin layers or in a thin metal film.
• circuit forming techniques on the support directly according to the chosen pattern.
• the means used in this case depend on the nature of the conductive material.
• a masking technique In particular in the techniques of forming conductive layers by pyrolysis or by vacuum deposition it is possible to use a masking technique. This mode is however relatively inconvenient to produce elements of very small dimensions (eg drivers). For this reason to form such drawings the most usual is to form the circuit by localized ablation from a united surface. Ablation, whatever the means used, in particular a laser beam, remains a relatively delicate and expensive operation.
• the mode of formation of the most usual circuit passes through a continuous conductive element on the entire surface of the support, followed by the formation of the pattern usually by localized ablation.
• the support and the conductive circuit being very thin, they must be associated with a holding means during and after cutting. Otherwise they would not be practically manipulable.
• the conductive surface and its support are reinforced by a semi-rigid sheet on which they are temporarily fixed.
• This semi-rigid sheet is advantageously of a polymer material having a limited adhesion to facilitate subsequent separation from the sensor itself. This is for example a sheet of polyethylene, polyamide, etc.
• the thickness of the sheet to give it the required rigidity is advantageously greater than 0.1 mm.
• the semi-rigid sheet gives the insert the consistency that allows its implementation in a convenient manner.
• the circuit can then be formed by cutting the layer and its support according to the shape of the final circuit the depth of the cut leaving substantially intact the semi-rigid sheet.
• the superfluous elements are eliminated the circuit and its support, which then have the same design, remain alone fixed on the semi-rigid sheet.
• the circuit thus formed is held on the semi-rigid sheet until it is applied to the glass sheet as will be described below with reference to the drawings.
• This method of manufacture is all the more advantageous as it corresponds to the general structures of products according to the invention necessarily comprising an adhesive which is preferably protected by a sheet.
• the same sheet can thus be used for cutting and subsequent application of the sensor.
• Conductive structures used according to the invention are, for example, layers of conductive oxide type, or thin metal layers protected by dielectric layers.
• the formation is advantageously obtained by a pyrolysis technique.
• the formation is obtained by vacuum techniques, such as magnetron sputtering.
• Metal films, silver, aluminum, copper, gold, platinum in particular are also usable, but must be very thin.
• the thickness of the layer is, of course, a function of the nature of the materials that constitute it.
• the thicknesses are advantageously between 25 and 200 ° and preferably between 50 and 150 °.
• the electrodes advantageously consist of a silver layer 60 to 140 thick, arranged between layers of oxide protecting the silver and to achieve a good neutrality of color in reflection in particular.
• the thickness is substantially greater, of the order of 50 to 1000 nm and most frequently 100 to 500 nm.
• the thicknesses can be even greater. They are for example between 1 and 50 ⁇ , and
• the sensor according to the invention is preferably of sufficiently low thickness to maintain an essentially transparent character.
• the light transmission in the visible range of the support elements and the capacitive circuit is advantageously greater than
• the supports used in the constitution of the inserts can be of varied nature. They are, for example, polypropylene sheets, high or low density polyethylene, but especially polyethylene glycol terephthalate (PET).
• PET polyethylene glycol terephthalate
• Preferred films are polyethylene glycol terephthalate (PET). These films have a high mechanical strength, which allows them to be used at extremely low thicknesses of the order of a few tens of microns. These low thicknesses favor a very important visible light transmission. In other words, the presence of this additional film does not cause a significant reduction in light transmission. Note that the very small thickness of the support does not affect the stability and accuracy of the pattern in the glazing. These are ensured by the use of the adhesive. Once applied to the glass sheet, the adhesion is such that the intrinsically fragile structure of the sensor is well stabilized. In the same way the fixing on a semi-rigid sheet before the application on the sheet of glass avoids the accidental deformations.
• PET polyethylene glycol terephthalate
• the sensor circuit essentially comprises the electrodes and possibly the conductive elements connecting these electrodes to the signal supply and analysis device.
• the electrodes are of such size and configuration that they develop sufficient capabilities to have adequate sensitivity to changes related to the presence of water drops.
• the conductors respond only to the need to connect the electrodes to the analyzer or to the ground. They are also as little as possible to the measured variations. They therefore have a relatively small surface area compared to those of the electrodes.
• the conductive surface may also extend beyond the elements forming the actual sensor. These conductive elements adjoining the sensor itself do not participate strictly speaking in the measurement. These conductive elements, which may also be grounded, are preferably of limited area so as not to unnecessarily increase the areas of the glazing comprising conductive elements, which even essentially transparent remain discernible.
• the conducting elements constituting the electrodes of the sensor must offer a certain capacity so that the modification of the dielectric constant related to the presence of water on the glazing introduces a significant variation of this capacity. For this reason the electrodes must offer a certain surface given that the thicknesses of the conductive layers are necessarily very small.
• the distance between the electrodes is low to favor the intensity of the electric fields, it is necessary that it is sufficient to prevent a risk of short circuit due to a possible insufficiently precise configuration. It is especially necessary that the surface located between the electrodes is sufficient so that the presence of drops of water on the glazing is detected from their appearance, and this regardless of the fact that their distribution is necessarily random. In this sense the increase of the surface "sensitive" to the presence of drops of water increases the probability of finding drops as soon as they appear.
• the design of the sensor may comprise two or three or more electrodes, depending on the signal to be developed and its mode of analysis.
• a type of sensor with two electrodes is described for example in European Application No. 04104149.2
• Another technique for analyzing the signal variation proposed previously requires the comparison of two capacitors.
• the so-called “differential” technique is based on the principle that within the limits of the size of the field on which the drops are capable of modifying the capacitance, two neighboring capacitors are never precisely modified in the same way, the random distribution not leading to variations of exactly the same magnitude.
• the analysis then consists of a capacity state corresponding to the absence of water, to detect the imbalances introduced by the presence of drops.
• both capacities can be formed from three or more electrodes.
• FIG. 1 is a schematic perspective representation of the principle of implementation of a rain sensor on a car windshield
• FIG. 2 illustrates in "exploded" a mode of arrangement of the elements of the glazing with respect to each other;
• FIG. 3a is a section along A-A of Figure 1 of a glazing assembled as in Figure 2;
• Figure 3b is a section similar to Figure 3a in which the insert is disposed between two intermediate sheets;
• FIGS. 4a and 4b are schematic perspective views of the basic elements of the insert according to the invention.
• FIG. 5 is a schematic perspective view of an assembly used according to the invention for the convenient implementation of the inserts according to the invention;
• FIG. 6 is a diagrammatic view of a means of cutting the circuits constituting a sensor according to the invention.
• FIG. 7 schematically illustrates a mode of application of an insert according to the invention
• FIGS. 8a and 8b schematically show an electrical connection mode according to the invention
• FIGS. 9a and 9b show another connection mode according to the invention.
• FIG. 10 schematically shows a drawing of the electrodes of a sensor according to the invention.
• FIG. 11 is another electrode pattern of a sensor according to the invention.
• FIG. 12 is yet another drawing of a sensor according to the invention.
• FIG. 13 shows an embodiment of an insert according to the invention wherein the connections with the outside of the glazing are integrated during the production of the insert.
• Figure 1 shows the typical arrangement of a rain sensor on a car windshield 1.
• the rain sensor 4 On the windshield the rain sensor 4 is necessarily located in a zone 2, 3 swept by the wipers. In the figure these areas are shown schematically by broken lines. This provision is controlled by the fact that the sensor 4 is intended to trigger the movement of the wipers in the presence of water on the scanned areas. Outside these areas, water may remain after rain has ceased. As a result, if the sensor were disposed out of the swept areas, the movement of the wipers could be unnecessarily maintained.
• the senor which has non-transparent elements is preferably located at a point where it does not cause any inconvenience to the driver. If nevertheless it is still in the field of vision, preferably this location is already obscured by another functional element. Very usually the optical sensors are arranged behind the interior rearview mirror.
• the fact that the electrodes are very largely transparent to visible radiation offers a greater latitude in the choice of this location, even if the surface occupied by the sensor is substantially larger than the masked surface. by traditional optical sensors.
• Capacitive sensors work with a set of analysis of the signals they generate. Most usually the assembly in question consists of a relatively small electronic circuit. It can even be reduced to a "chip" of a few square millimeters or less. This set is ordinarily non-transparent. For this reason it is advantageous to locate it outside the transparent part of the glazing. For the reasons indicated, however, the analysis assembly is as close as possible to the electrodes of the sensor. It is located for example behind the enamelled strips that are often placed at the edge of the glazing. Given their size, most often extremely small, they can even fit between the sheets of glass. The conductors connecting the electrodes to this analysis circuit are inevitably the seat of parasitic signals, except to protect them by a "shielding".
• This protection is generally not desirable insofar as it is established by means of sheaths that are not transparent. To ensure that the conductors are as little visible as possible, they are preferably unsheathed. They develop themselves a certain capacity which is superimposed on that of the electrodes of the sensor. To minimize this parasitic effect, it is desirable to shorten these conductors as much as possible. For this reason the sensor is normally near an edge of the glazing.
• the senor is, as is common, in the central high position, ie behind the rearview mirror. Given the essentially transparent nature another positioning is nevertheless possible.
• Figure 2 shows the superposition of the various elements of the glazing, and the location of the sensor as an insert.
• the glazing comprises two sheets of glass 9 and 10, and a thermoplastic interlayer sheet 11, for example PVB, intended to bond the two sheets of glass.
• the insert 15 carrying the circuit forming the sensor is disposed between the glass sheet 10 and the intermediate sheet 11.
• the sensor comprises a part on which the electrodes are arranged and a part 18 comprising the conductors which connect the electrodes to the assembly measurement not shown.
• the insert can be disposed between the outer glass sheet and the spacer to optimize sensitivity, but it can also be located between the spacer and the inner sheet.
• the section of the glazing unit of FIG. 3a reproduces the arrangement indicated with reference to FIG. 2.
• the electrodes 12 and 13 are schematically represented on a support 5.
• the various elements are disjoint in the figure and their exaggerated dimensions to better distinguish them.
• the dimensions of the electrodes in particular their thickness and the distances between them are voluntarily forced.
• the distances between the electrodes are relatively small, usually 1 to 5 millimeters, to maximize the electric field. It is a question of establishing a compromise between a sufficiently intense field, and a surface sufficient to cover a variation of field well representative of the detected phenomenon.
• the arrangement of Figure 3b is similar to the previous one.
• the insert is this time between two interlayer sheets 11a and 11b.
• the arrangement does not normally require the use of additional adhesive, but the use of two interlayers is not economical.
• the invention relates to the use of inserts between a spacer sheet and the glazing without the need to apply an adhesive at the time of assembly of the sheets.
• FIGS 4a and 4b show schematically exploded a set of elements involved in the constitution of a detector according to the invention.
• This set consists of a support sheet 5.
• This support sheet 5 is essentially non-conductive and sufficiently transparent. Its thickness for this reason as small as its role of support allows it.
• it is a PET film whose thickness is between 15 and 100 ⁇ .
• the conductive element 6 in which the capacitive circuit is formed.
• the element conductor is shown as a sheet or continuous layer, the circuit is not drawn.
• the entire support 5 and the conductive element 6 further comprises an adhesive coating 8.
• the adhesive 8 is represented on the face of the support 5 opposite to that comprising the conductive element 6.
• This arrangement is that which is advantageously used when the connections with the conductors external to the glazing are applied between the sheets. at the time of assembly thereof after the insert has been previously arranged on the glass sheet as indicated below.
• the arrangement of Figure 4b according to which the adhesive 8 for fixing on the glazing is on the conductive element is equally satisfactory. The latter is advantageous when the insert has the external conductors even before application to the glass sheet (see Figure 13). In this case once the insert applied to the glass sheet, the circuit is protected by the support 5 against possible alterations at the time of assembly of the sheets constituting the glazing.
• the adhesive 8 must itself be covered until the installation of the capacitive detector.
• a film (not shown in Figures 4a and 4b) that can be easily removed (“stripable”) is used.
• stripable its contact face with the adhesive can advantageously in a known manner be coated with a release-resistant compound, for example a compound based on silicone wax. This release agent also ensures the retention of the adhesive on the insert during the removal of the protective film.
• Figure 5 further comprises a film 17 and its adhesive coating 7.
• This film 17 is shown relatively thick relative to the other constituents. It is convenient indeed to facilitate handling to have a less flexible element that is the support 5. The flexibility of the latter is mainly due to its very small thickness.
• the film 17 which is removed at the time of installation of the detector on the glazing may advantageously be in the form of a semi-rigid sheet, in particular to facilitate handling.
• the removal of the film 17 normally causes the adhesive 7 which in the structure shown in this figure is not intended for fixing on the glass, unlike the adhesive 8.
• the other side, which in the form presented is in contact with the interlayer material of the laminated glazing may not require the presence of additional adhesive.
• the adhesion may be improved as indicated above either by the use of a adhesive either by a modification treatment of the PET surface for example by "flame" or activation by plasma.
• the adhesive which holds the detector on the glass sheet (in the form shown in FIG. 5, the adhesive 8) is advantageously relatively powerful, whereas that that (7) which mainly maintains the protective film 17 may be significantly less powerful especially to allow easy removal of the protective film 17 ..
• the presence of a sufficiently rigid sheet 17 in the detector packaging may have additional advantages. If the conductive element 6 can be produced in the various previously mentioned ways relatively easily, the formation of the circuit, in other words the separation of conductive zones and non-conductive zones according to a precise drawing, requires relatively delicate operations in the modes previously proposed. .
• the invention makes it possible to use a simpler and less expensive type of stamping technique to constitute the circuit.
• the embodiment is illustrated schematically in FIG. 6.
• the support sheet 5 of the detector covered with the conductive element 6 (whether it be thin layers or a thin metallic sheet ), is fixed on the sheet 17 by means of the adhesive 7.
• the assembly 6, 5 is subjected to cutting by stamping. Precise adjustment limits the depth of the cut.
• the punch (or punch) 19 is shown schematically in Figure 6 in the deepest part of the cut. The latter can start the sheet 17 but must maintain the integrity of this sheet so that the formed circuit, which may comprise tenuous elements, remains well shaped on this sheet 17.
• the protection of this circuit is possibly completed by the introduction of the adhesive 8 and the protective film 16.
• the adhesive 8 and the film 16 are applied separately or simultaneously. If the adhesive 8 is to be relatively powerful to fix in a subsequent operation the detector on the glass sheet, the adhesion to the sheet 16 must be well controlled so that the separation of this sheet does not risk damaging the circuit during the transfer on the glass sheet or the removal of a portion of the adhesive 8. For this, if necessary the choice of the nature of the sheet 16 allows to limit the adhesion. This adhesion can also be controlled by the use of a coating, for example a silicone wax applied to the sheet 16.
• the mode of application of a detector comprising an assembly as represented in FIGS. 5 and 6, preferably comprises the following sequence:
• the circuit 6 and its support 5, which adhere to the protective film 17 via the adhesive 7, are firmly applied for example by means of a pressure roller 22 on the glass sheet 20 (FIG. 7) (possibly after the interposition of the external conductors, but preferably these are pre-arranged in the structure of the insert); the adhesive is advantageously of the pressure-activated type;
• the assembly of the glass, glass sheets and thermoplastic sheet, for example PVB is carried out according to the traditional techniques of lamination namely vacuum steaming and / or calendering techniques.
• the constituent elements of the inserted detector do not undergo operating conditions, in particular thermal conditions, capable of altering them.
• the pressures are normally exerted in terms of these elements without shearing force.
• the detector therefore does not risk deformation or tearing, or especially occurrence of short circuits between the separate conductive elements.
• connection means With the assembly of the sheets, the connection means must be put in place. Either the support and the conductors it carries, extend beyond the glazing. In this case the junction takes place outside the glazing and preferably in a set of "encapsulated" type, which prevents the risk of rupture of the support sheet, the latter being secured to the glass sheets in a a strong envelope from which the conductors which connect to the means for generating and analyzing the signals depart. Either conductors are reported in the glazing itself at the time of assembly of the sheets, traditional connecting elements of these conductors with the means of analysis completing the circuit. The first of these two modes is illustrated in Figures 8a and 8b.
• the support 5 taken between the glass sheet 10 and the interlayer sheet 11 exceeds the edge of the glazing of a portion 18 possibly forming a tongue.
• This portion 18 is advantageously folded and glued on the face of the glazing as 8b.
• Local "encapsulation" 23 formed for example by molding a shell of polymeric material by means for example of a thermoplastic material formed directly on the edge of the glazing. Connections with the conductors connected to the analysis device are for example provided by means of ribbon conductors 24 applied to the ends of the portion 18.
• the fixing of the conductors can be obtained by welding, gluing or crimping.
• the encapsulation 23 possibly makes it possible to avoid additional fixing the conductors are then simply brought into contact and embedded in the encapsulating material.
• Figures 9a and 9b illustrate the second mode of connection of the electric circuit.
• the constituent elements are shown exploded in Figure 9a as they are before assembly of the glazing.
• the contact between the reported conductor 25 and the corresponding conductor end of the detector circuit disposed on the support 5 is in the glazing itself.
• the maintenance of the outer conductor can then be ensured by the fact that it is caught in the lamination.
• the electrical continuity between the circuit of the detector and the conductor 25 is ensured possibly by simple contact and under the pressure exerted by the lamination. It is preferred to have either a solder or a conductive adhesive to prevent any failure.
• FIG. 13 shows another mode to ensure the electrical connections of the sensor with the elements outside the glazing.
• the figure shows the elements of Figure 6 after they have been joined together.
• the constitution of the circuit can be obtained as shown in FIG. 6 by die-cutting or by any other means, in particular by localized ablation of the conductive layer as indicated above.
• the conductors 25 are integrated in the assembly constituting the insert before it is placed in the glazing.
• the conductor 25 is in electrical contact with the elements 6 constituting the sensor.
• Their attachment may be at least partly achieved by the adhesive 8 which holds the protective sheet 16, which adhesive is subsequently used for bonding to the glass sheet. Nevertheless a stronger attachment of the conductor may be preferred. This may include the local use of a conductive glue or solder.
• the realization of this type of assembly limits as much as possible the operations performed during the assembly of the glazing. These only include the application and gluing on the glass sheet after removing the protective film 16 and the same detachment of the sheet 17.
• the sensor and its conductors 25 is then ready.
• the assembly of the glazing continues according to traditional techniques.
• FIG. 10 is an example of a circuit constituting a sensor according to the invention.
• the sensor shown has two electrodes 26 and 27 of rectangular shape.
• the same material which constitutes the electrodes also forms two conductors 28, 29 which terminate in connection pads 30 and 31 to which unrepresented external conductors are connected. All of these elements constitute the sensor circuit.
• two conductive elements 32, 33 remain from the operation of forming the design of the sensor from a support uniformly covered with the conductive element.
• These bodies which may possibly be removed as the non-conductive zones separating the electrodes, may be involved in the development of the signal and its treatment, especially when they are grounded.
• the sensor of FIG. 11 comprises three electrodes 34,
• the two capacitors consist of a common central electrode 35 and each of the lateral electrodes 34 and 36.
• the same differential mode can also be implemented with two completely separate capacitors, for example with four electrodes forming two by two capacitors.
• the trapezoidal shape of the electrodes and the distance between their respective edges which is not constant has the effect of promoting good detection of the drops regardless of how they appear, thin and many or, conversely, large and spaced.
• the arrangement presented leads to electric field intensities that are not uniform along the electrodes.
• the detection area is increased with the distance between the electrodes. To reduce the background noise caused by the conductors as much as possible, they are also located as close as possible to one another.
• the sensor of FIG. 11 can be introduced with a support 37 which extends well beyond the electrodes. It is however preferable, by taking advantage of the method of manufacture described above to cut support and electrical circuit according to the final design of the sensor. In this case the support 37 is superimposed exactly on the electrodes and the conductors.
• the sensor shown in FIG. 12 also comprises three electrodes 38, 39, 40, for example for differential operation.
• the measurement field is this time made between the electrodes 38 and 39 which have two distances Z 1 and z 2 to allow, as for the sensor of FIG. 11, to detect the drops of different dimensions.
• the electric field is more intense and makes it possible to detect drops of small dimensions.
• the sensitivity in the zone of distance z 2 in which the field is less intense increases the available surface and therefore the probability of finding a "big" drop less regularly distributed.
• the less intense field is compensated by the size of the drop which causes a more important modification of this field.

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• Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Mechanical Engineering (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

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• 2007
  • 2007-08-02 EP EP07802465A patent/EP2046610A1/de not_active Withdrawn
  • 2007-08-02 WO PCT/EP2007/058002 patent/WO2008015251A1/fr active Application Filing

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