Windshield with electrically controllable sun visor

Abstract

A windshield with an electrically controllable sun visor is described. The windshield includes an outer pane and an inner pane that are bonded to one another via an intermediate layer. According to one aspect, a functional element with electrically controllable optical properties is incorporated into the intermediate layer and above a central field of vision. The functional element is connected to the outer pane via a region of a first thermoplastic layer, and is connected to the inner pane via a region of a second thermoplastic layer. According to another aspect, the region of the first thermoplastic layer and/or the region of the second thermoplastic layer is tinted or colored.

Claims

1. A Windshield with an electrically controllable sun visor, the windshield comprising: an outer pane; an intermediate layer; and an inner pane bonded to the outer pane via the intermediate layer, wherein above a central field of vision, a functional element with electrically controllable optical properties is incorporated into the intermediate layer, wherein the functional element is connected to the outer pane via a region of a first thermoplastic layer, and is connected to the inner pane via a region of a second thermoplastic layer, and wherein at least one of the region of the first thermoplastic layer and the region of the second thermoplastic layer is a tinted or colored region, and wherein the functional element is divided by isolating lines into segments that can be electrically actuated separately.

2. The windshield according to claim 1, wherein the intermediate layer is transparent in the central field of vision.

3. The windshield according to claim 1, wherein the functional element is a polymer dispersed liquid crystal.

4. The windshield according to claim 1, wherein the tinted or colored region has a transmittance in the visible spectral range of 10% to 50%.

5. The windshield according to claim 1, wherein the tinted or colored region has a transmittance in the visible spectral range of 20% to 40%.

6. The windshield according to claim 1, wherein the functional element comprises an edge seal that is formed by a transparent colorless adhesive and a transparent colorless adhesive tape.

7. The windshield according to claim 1, wherein the functional element is peripherally surrounded by a third thermoplastic layer.

8. The windshield according to claim 7, wherein the lower edge of the functional element is arranged flush with the third thermoplastic layer.

9. The windshield according to claim 1, wherein the upper edge and the side edges of the functional element are obscured in through-vision by an opaque masking print.

10. The windshield according to claim 1, wherein the first thermoplastic layer and the second thermoplastic layer comprise at least one of: polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), and/or polyurethane (PU).

11. The windshield according to claim 1, wherein the first thermoplastic layer and the second thermoplastic layer comprise polyvinyl butyral (PVB).

12. The windshield according to one of claim 1, wherein the tinted or colored region protrudes beyond the lower edge of the functional element.

13. A Vehicle having a windshield, comprising: a windshield including an outer pane; an intermediate layer; and an inner pane bonded to the outer pane via the intermediate layer, wherein above a central field of vision, a functional element with electrically controllable optical properties is incorporated into the intermediate layer, wherein the functional element is connected to the outer pane via a region of a first thermoplastic layer, and is connected to the inner pane via a region of a second thermoplastic layer, and wherein at least one of the region of the first thermoplastic layer and the region of the second thermoplastic layer is a tinted or colored region and wherein the vehicle is devoid of a roof-mounted mechanically hinged sun visor, and wherein the functional element is divided by isolating lines into segments that can be electrically actuated separately.

14. A method for producing a windshield with an electrically controllable sun visor, the method comprising: arranging in order, one atop another, an outer pane, a first thermoplastic layer, a functional element with electrically controllable optical properties, a second thermoplastic layer, and an inner pane, wherein the functional element is arranged in a region above a central field of vision, and wherein the functional element is divided by isolating lines into segments that can be electrically actuated separately and wherein the first thermoplastic layer and the second thermoplastic layer has a tinted or colored region that is arranged between the functional element and the outer pane and the inner pane, and bonding the outer pane and the inner pane by lamination, thereby forming, from the first thermoplastic layer and the second thermoplastic layer, an intermediate layer with an incorporated functional element.

15. The method according to claim 14, wherein the functional element is in the form of a multilayer film and is cut to size using a laser.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are a schematic representation and are not to scale. The drawings in no way restrict the invention. They depict:

(2) FIG. 1 a plan view of a first embodiment of the windshield according to the invention,

(3) FIG. 2 a cross-section through the windshield of FIG. 1,

(4) FIG. 3 an enlarged representation of the region Z of FIG. 2,

(5) FIG. 4 a cross-section through another embodiment of the windshield according to the invention,

(6) FIG. 5 a plan view of another embodiment of the windshield according to the invention,

(7) FIG. 6 an exemplary embodiment of the method according to the invention using a flowchart.

DETAILED DESCRIPTION

(8) FIG. 1, FIG. 2, and FIG. 3 depict in each case a detail of a windshield according to the invention. The windshield comprises an outer pane 1 and an inner pane 2, which are bonded to one another via an intermediate layer 3. The outer pane 1 has a thickness of 2.1 mm and is made of a green-colored soda lime glass. The inner pane 2 has a thickness of 1.6 mm and is made of a clear soda lime glass. The windshield has an upper edge D facing the roof in the installed position and a lower edge M facing the engine compartment in the installed position.

(9) The windshield is equipped with an electrically controllable sun visor 4 in a region above the central field of vision B (as defined in ECE-R43). The sun visor 4 is formed by a commercially available PDLC multilayer film as functional element 5, which is incorporated into the intermediate layer 3. The height of the sun visor is, for example, 21 cm. The intermediate layer 3 comprises a total of three thermoplastic layers 6, 7, 8, which is in each case implemented by a thermoplastic film with a thickness of 0.38 mm made of PVB. The first thermoplastic layer 6 is bonded to the outer pane 1; the second thermoplastic layer 7, to the inner pane 2. The third thermoplastic layer 8 therebetween has a cutout, into which the PDLC multilayer film cut to size is inserted with a precise fit, in other words, flush on all sides. The third thermoplastic layer thus forms, so to speak, a sort of mat for the functional element 5, which is thus encapsulated all around in a thermoplastic material and is thus protected.

(10) The first thermoplastic layer 6 has a tinted region 6a that is arranged between the functional element 5 and the outer pane 1. The light transmittance of the windshield is thus additionally reduced in the region of the sun visor 4 and the milky appearance of the PDLC functional element 5 is mitigated in the diffusive state. The aesthetics of the windshield thus become significantly more attractive. The first thermoplastic layer 6 has in the region 6a, for example, an average light transmittance of 30%, with which good results are obtained.

(11) The region 6a can be homogeneously tinted. However, it is visually more attractive for the tinting to decrease in the direction of the lower edge of the functional element 5 such that the tinted and the untinted region transition smoothly from one to the other.

(12) In the case depicted, the lower edges of the tinted region 6a and of the PDLC functional element 5 are arranged flush. This is, however, not necessarily the case. It is also possible for the tinted region 6a to protrude beyond the functional element 5 or, conversely, for the functional element 5 to protrude beyond the tinted region 6a. In the latter case, the entire functional element 5 would not be bonded to the outer pane 1 via the tinted region 6a.

(13) The controllable functional element 5 is a multilayer film, consisting of an active layer 11 between two flat electrodes 12, 13 and two carrier films 14, 15. The active layer 11 includes a polymer matrix with liquid crystals dispersed therein, which align themselves as a function of the electrical voltage applied to the flat electrodes, by which means the optical properties can be controlled. The carrier films 14, 15 are made of PET and have a thickness of, for example, 0.125 mm. The carrier films 14, 15 are provided with a coating of ITO facing the active layer 11 and having a thickness of approx. 100 nm, which form the electrodes 12, 13. The electrodes 12, 13 can be connected to the vehicle's electrical system via busbars (not shown) (implemented, for example, by a silver-containing screen print) and connection cables (not shown).

(14) The windshield has, as is customary, a surrounding peripheral masking print 9, which is implemented by an opaque enamel on the interior-side surfaces (facing the interior of the vehicle in the installed position) of the outer pane 1 and of the inner pane 2. The distance of the functional element 5 from the upper edge D and from the side edges of the windshield is less than the width of the masking print 9 such that the side edges of the functional element 5with the exception of the side edge pointing toward the central field of vision Bare obscured by the masking print 9. The electrical connections (not shown) are also reasonably installed in the region of the masking print 9 and thus hidden.

(15) The side edges of the functional element 5 are provided peripherally with an edge seal 10, which is implemented by a transparent acrylic adhesive tape. Diffusion into or out of the active layer 11 is thus prevented. Since the edge seal 10 is transparent, the lower side edge, which is not obscured by the masking print 9, is also not disturbingly conspicuous. The edge seal 10 runs peripherally around the side edges of the multilayer film and extends, starting from the side edges, a few millimeters over the surfaces of the carrier films 14, 15 facing away from the active layer 11. The edge seal 10 prevents, in particular, the diffusion of plasticizers and other adhesive components of the thermoplastic layer 8 into the active layer 11, by which means the aging of the functional element 5 is reduced.

(16) A so-called high flow PVB, which has stronger flow behavior compared to standard PVB films, can preferably be used for the thermoplastic layers 6, 7, 8. Thus, the layers flow more strongly around the functional element 5, by which means a homogeneous visual impression is created and the transition from the functional element 5 to the layer 8 is less conspicuous. The high flow PVB can be used for all or even for only one or a plurality of the thermoplastic layers 6, 7, 8 having direct contact with the functional element 5.

(17) FIG. 4 depicts a cross-section through another embodiment of the windshield according to the invention. The tinted region 6a of the first thermoplastic layer 6 protrudes beyond the lower edge of the functional element 5. The protruding portion of the tinted region 6a can have a transmittance progression such that the tinting phases out, so to speak, toward the central field of vision.

(18) FIG. 5 depicts a plan view of another embodiment of the design of the windshield according to the invention. The windshield and the controllable sun visor 4 correspond substantially to the embodiment of FIG. 1. The PDLC functional element 5 is, however, divided by horizontal isolating lines 16 into six strip-like segments. The isolating lines 16 have, for example, a width of 40 m to 50 m and mutual spacing of 3.5 cm. They were introduced into the prefabricated multilayer film using a laser. The isolating lines 16 separate, in particular, the electrodes 12, 13 into strips isolated from one another, each of which has a separate electrical connection. Thus, the segments are switchable independently of one another. The thinner the isolating lines 16, the more inconspicuous they are. Yet thinner isolating lines 16 can be realized using etching methods.

(19) The segmentation enables adjusting the height of the darkened sun visor 4. Thus, the driver can darkened the entire sun visor 4 or only a part thereof depending on the position of the sun. The figure indicates that the upper half of the sun visor 4 is darkened and the lower half is transparent.

(20) In a particularly convenient embodiment, the segmented sun visor 4 is controlled by a capacitive switching area arranged in the region of the sun visor 4, wherein the driver specifies the degree of darkening by means of the location at which he touches the pane. Alternatively, the sun visor 4 can also be controlled by contact-free methods, for example, by recognizing gestures, or as a function of the state of the pupil or eyelid detected by a camera and suitable evaluation electronics.

(21) FIG. 6 depicts an exemplary embodiment of the production method according to the invention using a flowchart.

LIST OF REFERENCE CHARACTERS

(22) (1) outer pane

(23) (2) inner pane

(24) (3) intermediate layer

(25) (4) electrically controllable sun visor

(26) (5) functional element with electrically controllable optical properties

(27) (6) first thermoplastic layer

(28) (6a) tinted region of the first thermoplastic layer

(29) (7) second thermoplastic layer

(30) (8) third thermoplastic layer

(31) (9) masking print

(32) (10) edge seal

(33) (11) active layer of the functional element 5

(34) (12) flat electrode of the functional element 5

(35) (13) flat electrode of the functional element 5

(36) (14) carrier film

(37) (15) carrier film

(38) (16) isolating lines

(39) B central field of vision of the windshield

(40) D upper edge of the windshield, roof edge

(41) M lower edge of the windshield, engine edge

(42) X-X section line

(43) Z enlarged region