Obscuration having superior strength and optical quality for a laminated automotive windshield

Abstract

Laminated automotive glazing including plastic layers and glass having an obscuration area produced by printing on the plastic layers of the laminate rather than printing and firing a black enamel frit onto the glass. This results in an obscuration having superior optical quality, higher strength and a lower probability of breakage as compared to a black enamel frit obscuration.

Claims

1. A laminated windshield comprising: at least two glass layers; at least two plastic layers sandwiched between the at least two glass layers, the at least two plastic layers attaching said at least two glass layers to each other; at least one obscuration produced by inkjet printing said obscuration onto two surfaces of the at least two plastic layers to produce a three dimensional appearance; a UV blocking plastic layer sandwiched between the at least two glass layers; and a color correction filter printed directly onto at least one of the at least two plastic layers; wherein the laminated windshield has improved fracture strength, reduced distortion and reduced double image.

2. The laminated windshield of claim 1 further comprising an equipment obscuration printed onto at least one of the at least two plastic layers.

3. The laminated windshield of claim 1 further comprising a black band obscuration printed onto at least one of the at least two plastic layers.

4. The laminated windshield of claim 3 further comprising an equipment obscuration separate from and spaced from the black band obscuration.

5. The laminated windshield of claim 1 further comprising a wiper rest obscuration printed onto at least one of the at least two plastic layers.

6. The laminated windshield of claim 1 further comprising at least one performance film plastic layer.

7. The laminated windshield of claim 1, wherein the obscuration is printed on two parallel surfaces of the at least two plastic layers.

8. The laminated windshield of claim 1, wherein at least one performance film plastic layer is sandwiched between the at least two plastic layers.

9. The laminated windshield according to claim 1, wherein the improved fracture strength is about 115 Mpa, the reduced distortion is 25 milli diopters, and the reduced double image is 3 arc minute.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a typical automotive windshield with a black band obscuration 32, a wiper rest obscuration 31 and an equipment obscuration 34 extending downward from the black band obscuration, having openings 30 to provide a forward field of view for two cameras.

(2) FIG. 2 shows an automotive windshield with a black band 32, a wiper rest obscuration 31 and an obscuration 34 separated from the black band, having openings 30 to provide a forward field of view for two cameras.

(3) FIG. 3 shows a panoramic automotive windshield with a black band 32, a wiper rest obscuration 31 and an obscuration 34 separated from the black band, having openings 30 to provide a forward field of view for two cameras.

(4) FIG. 4 shows the obscuration 8 of the prior art, a black enamel frit applied to the fourth surface 24.

(5) FIG. 5 shows the obscuration 8 printed on the interlayer 4 facing the third surface 23.

(6) FIG. 6 shows the obscuration 8 printed on the interlayer 4 facing the second surface 22.

(7) FIG. 7 shows the obscuration 8 printed on both sides of the interlayer 4.

(8) FIG. 8 shows the obscuration 8 printed on a sheet of plastic laminated between two sheets of interlayer 4.

(9) FIG. 9 shows the obscuration 8 printed on a sheet of performance plastic laminated between two sheets of plastic interlayer 4 having an obscuration 8 printed on at least one side.

REFERENCE NUMERALS

(10) 3 Performance Plastic Layer

(11) 4 Plastic Interlayer Layer

(12) 5 Glass

(13) 8 Obscuration

(14) 10 Equipment Mounted To Glass

(15) 12 Device Housing

(16) 14 Cover

(17) 17 Film

(18) 21 First Surface Of Glass

(19) 22 Second Surface Of Glass

(20) 23 Third Surface Of Glass

(21) 24 Fourth Surface Of Glass

(22) 30 Openings In Equipment Obscuration

(23) 31 Wiper Rest Obscuration

(24) 32 Black Band Obscuration

(25) 34 Equipment Obscuration

DETAILED DESCRIPTION OF THE INVENTION

(26) Experimental Results

(27) Experimental results have demonstrated the remarkable magnitude of improvement of the invention and are shown in the following table (Table 1). Fracture strength is more than doubled, distortion is reduced by a factor of six and double image if reduced from 20 to 3. One should also note that all three of these parameters are critical to the operation of a safety camera.

(28) TABLE-US-00001 TABLE 1 Laminate w/ BEF Laminate w/ PI Fracture Strength (ring-on- 60 Mpa 115 Mpa ring) Distortion Camera window - 150 milli diopters 25 milli diopters 5 mm from the black edge) Double image (Camera 20 (arc minute) 3 (arc minute) window - 5 mm from the black edge) BEF = Black enamel frit PI = Printed interlayer with Clear glass

(29) Advantages

(30) 1. Frit induced surface defects are eliminated.

(31) 2. Residual stress caused by non-uniform heating of the frit is eliminated.

(32) 3. Residual stress causing surface mis-match due to the frit is eliminated.

(33) 4. Low distortion, comparable to ordinary clear glass.

(34) 5. Low double image, comparable to ordinary clear glass.

(35) 6. Lower probability of breakage.

(36) 7. Higher yield during bending due to elimination of non-uniform heating.

(37) 8. Higher yields during lamination due to higher strength, lower residual stress and less surface mismatch.

(38) 9. The ink jet process allows printing of a high resolution fade out, reducing sensitivity to variation.

(39) 10. Reduced sensitivity to equipment placement due to grayscale capability.

(40) TABLE-US-00002 TABLE 2 # Band Wiper Equipment 1 F F F 2 F F P 3 F P F 4 F P P 5 P F F 6 P F P 7 P P F 8 P P P F = Fired Frit P = Printed Ink

(41) Enamel frit and printed ink can both be used on the same part and in any combination that is convenient. With the three obscuration areas defined, there are eight possible combinations (#1, all black enamel frit is the prior art).

(42) When there is a laminate with a single sheet of interlayer, an obscuration can be printed on neither, either or both surfaces. If a sheet of performance film is added, there is the option of printing on neither, either or both surfaces of either of the sheets of interlayer and likewise on neither, either or both surfaces of the performance film. As can be appreciated, if the ways to print an obscuration are combined with the seven possible ways to select the obscuration areas printed with ink, there are too many variations to enumerate although each combination could be applied to the laminates of FIGS. 1, 2 and 3 and comprise an equivalent embodiment.

Embodiment 1

(43) The windshield of FIG. 1 comprising a black enamel frit band 32, a black enamel frit wiper rest area 31 and an equipment obscuration 8, 34 printed on one surface of the interlayer (FIG. 5 and FIG. 6).

Embodiment 2

(44) The windshield of FIG. 1 comprising a black enamel frit band 32, a black enamel frit wiper rest area 31 and an equipment obscuration 8, 34 printed on both surfaces of the interlayer (FIG. 7).

Embodiment 3

(45) The windshield of FIG. 1 comprising a wiper rest 31, black band 32 and an equipment obscuration 8, 34 printed on one surface of the interlayer (FIG. 5 and FIG. 6).

Embodiment 4

(46) The windshield of FIG. 1 comprising a wiper rest 31, black band 32 and an equipment obscuration 8, 34 printed on both surfaces of the interlayer (FIG. 7).

Embodiment 5

(47) The windshield of FIG. 1 comprising a performance film 17, a wiper rest 31, black band 32 and an equipment obscuration 8, 34 printed on one surface of the interlayer (FIG. 8).

Embodiment 6

(48) The windshield of FIG. 1 comprising a performance film 17, a wiper rest 31, black band 32 and an equipment obscuration 8, 34 printed on multiple surfaces (FIG. 9).

Embodiment 7

(49) The obscuration combinations of the previous embodiments, 1-6, further comprising an equipment obscuration separate from the black band and spaced from said black band by at least 3 mm illustrated in FIG. 2.

Embodiment 8

(50) A panoramic windshield (FIG. 3) with the equipment obscuration printed on one surface of the interlayer and an enamel frit wiper rest/black band.

Embodiment 9

(51) A panoramic windshield (FIG. 3) comprising and equipment obscuration printed on both surfaces of the interlayer.

Embodiment 10

(52) A panoramic windshield (FIG. 3) comprising a performance film and an equipment obscuration 8, 34 printed on multiple surfaces (FIG. 9).

Embodiment 11

(53) A panoramic windshield (FIG. 3) comprising and equipment obscuration and a color correction filter printed on the interlayer.

Embodiment 12

(54) A panoramic windshield (FIG. 3) comprising and equipment obscuration printed on both surfaces of the interlayer such that the obscuration is given a three dimensional appearance.