JP2011207645A - Laminated glass for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide laminated glass for vehicle preventing a double image while preventing the occurrence of distortion.SOLUTION: The laminated glass 50 for vehicle comprises first window glass 51 provided in the vehicle interior side, an interlayer 52 stuck on the vehicle exterior side of the first window glass 51 and having a wedge shape in the cross-sectional view and second window glass 53 provided in the vehicle exterior side of the interlayer 52 and stuck to the interlayer 52, wherein information from a head-up display device 54 is projected on the first window glass 51. The curvature radius R2 in the height direction of the second window glass 53 is larger than the curvature radius R1 in the height direction of the first window glass 51. The interlayer 52 made thin to prevent the occurrence of the distortion is adopted. The double image occurring by making the interlayer 52 thin is prevented by increasing the curvature radius R2 of the second window glass 53 and changing the reflection direction of a virtual image. Thereby the double image is prevented while preventing the occurrence of the distortion.

Description

  The present invention relates to a laminated glass used in a vehicle.

  It is known to project information such as vehicle speed on a windshield of a vehicle with a head-up display device. It is also known to use laminated glass for the windshield of a vehicle. It has been proposed to project information such as vehicle speed onto such a laminated glass with a head-up display device (see, for example, Patent Document 1 (FIG. 2)).

Patent document 1 is demonstrated based on the following figure.
As shown in FIG. 13, the laminated glass 100 is bonded to the first window glass 101 on the passenger compartment side, the wedge-shaped intermediate film 102 bonded to the first window glass 101, and the intermediate film 102. Second window glass 103.

  The taper angle of the wedge-shaped intermediate film 102 sandwiched between the first and second window glasses 101 and 103 is set to θt. By setting the taper angle θt to a predetermined angle, a real image 104 (main image) projected on the first window glass 101 and a virtual image 105 (double image) appearing by reflection on the second window glass 103 are obtained. Overlap. Since the real image 104 and the virtual image 105 overlap, the double image phenomenon in which the images appear to be double can be prevented.

  That is, by adjusting the taper angle θt, the angle at which the second window glass 103 is installed with respect to the first window glass 101 is adjusted, and the double image phenomenon can be prevented.

  By the way, when the taper angle θt is increased, the thickness W of the intermediate film is increased. Due to the large thickness W of the intermediate film, the problem described in the next figure arises.

As shown in FIG. 14, the object 111 to be visually recognized outside the laminated glass 100 is recognized by the driver's eyes 112 through the laminated glass 100.
By the way, the refractive index of the intermediate film 102 differs from the refractive indexes of the first and second window glasses 101 and 103 due to the different materials. Due to the difference in refractive index, the object 112 is recognized by the eye 112 in a distorted state.

In particular, when the taper angle (FIG. 12, sign θt) is increased, the thickness W of the intermediate film near the upper end of the laminated glass 100 is particularly increased. When the thickness W is large, distortion becomes remarkable.
Based on this knowledge, the present inventors conducted an experiment. The contents of the experiment will be described with reference to FIG.

  Experiments were performed to observe the occurrence of double images and the occurrence of distortion while changing the taper angle of the intermediate film 102 shown in FIG. The results are shown in the following table.

  First, an experiment was performed at a taper angle θ1 in accordance with the conditions described in Patent Document 1. That is, θ1 is the same angle as θt. In the case of θ1, a double image did not occur and distortion occurred.

  Next, an experiment was conducted with the taper angle θ2. θ2 is smaller than θt. That is, a thin interlayer film was used. At θ2, a double image was generated and no distortion was generated.

  Finally, an experiment was conducted with a taper angle θ3. θ3 is larger than θt. That is, a thick intermediate film was used. At θ3, a double image was generated and a large distortion was generated.

  It is desired to provide a laminated glass for a vehicle that can prevent double images while preventing distortion.

JP-A-2-279437

  This invention makes it a subject to provide the laminated glass for vehicles which can prevent a double image, preventing generation | occurrence | production of distortion.

According to a first aspect of the present invention, a first window glass provided on the vehicle interior side, an intermediate film bonded to the vehicle outer side of the first window glass and exhibiting a wedge shape in cross section, and provided on the vehicle outer side of the intermediate film. It consists of a second window glass bonded to an interlayer film, and is a laminated glass for vehicles in which information from the head-up display device is projected onto the first window glass,
The curvature radius in the height direction of the second window glass is larger than the curvature radius in the height direction of the first window glass.

By setting the taper angle small, an increase in the thickness of the intermediate film can be suppressed, and image distortion can be prevented.
However, when the taper angle is reduced, the double image tends to become prominent.
Therefore, in claim 1, the curvature radius in the height direction of the second window glass is made larger than the curvature radius in the height direction of the first window glass. When the radius of curvature of the second window glass is changed, the appearance direction of the virtual image is changed. By changing the radius of curvature of the second window glass, the appearance direction of the virtual image coincides with the real image, thereby preventing the generation of a double image. As a result, double images can be prevented while preventing distortion.

It is a figure explaining 1st experiment. It is a graph explaining a 1st experiment result. It is sectional drawing of the laminated glass for vehicles used for the 2nd experiment. It is a figure explaining 2nd experiment. It is a graph explaining the result of experiment number 1. It is a graph explaining the result of experiment numbers 2 and 3. It is a graph explaining the result of experiment numbers 4-6. It is a graph explaining the result of experiment numbers 7-12. It is a graph explaining the result of a 2nd experiment. It is a graph explaining the result of an additional experiment. It is a figure explaining the reason of an experimental result. It is sectional drawing of the laminated glass for vehicles which concerns on this invention. It is a figure explaining the basic principle of the prior art. It is a figure explaining the problem of the prior art.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, generally, a laminated glass 10 for a vehicle includes a first window glass 11 provided on the vehicle interior side, and an intermediate film that is bonded to the vehicle exterior side of the first window glass 11 and has a wedge shape in a sectional view. 12 and a second window glass 13 provided outside the intermediate film 12 and bonded to the intermediate film 12.
A head-up display device 14 for projecting information is disposed below the laminated glass 10 for vehicles.

  The inventors conducted experiments on the generation of a double image and the generation of distortion while changing the taper angle θn of the intermediate film 12. Specifically, it was examined how the distance t from the real image to the virtual image is related to the taper angle θn. In addition, the taper angle θn and the distortion of the upper part of the vehicle window glass were also observed. The result will be described with reference to the next figure.

  As shown in FIG. 2A, the horizontal axis indicates the taper angle θn, and the vertical axis indicates the distance t between the real image and the virtual image. It was found that the double image distance increases as the taper angle θn decreases. The region below the position indicated by the imaginary line 15 can be said to be a double image that does not matter even if a double image is generated.

As shown in (b), the horizontal axis indicates the taper angle θn, and the vertical axis indicates the magnitude of distortion. The distortion increases as the taper angle θn increases. When the magnitude of the distortion is below the position indicated by the imaginary line 16, it is a distortion that does not matter even if a distortion occurs.
Based on the above findings, the present inventors have obtained the following idea. Details are described in the following figure.

  As shown in FIG. 3, an intermediate film 22 having a taper angle θn is used, and a first window glass 21 and a second window glass 23 having different curvature radii in R1 and R2 are used.

  When the intermediate film 22 is selected after the first and second window glasses 21 and 23 are determined in advance, the taper angle θn of the intermediate film 22 may become too large. Distortion occurs when the taper angle θn is too large.

  Therefore, the present inventors prepared in advance an intermediate film 22 having a taper angle θn that does not cause distortion. Next, the second window glass 23 is inclined with respect to the first window glass 21 by setting the curvature radius R 1 of the first window glass 21 and the curvature radius R 2 of the second window glass 23 to different values. It has been found that the direction in which the virtual image is reflected is adjusted by inclining the second window glass 23 with respect to the first window glass 21.

Based on this knowledge, the present inventors conducted an experiment to derive what kind of second window glass 23 should be selected for the first window glass 21.
The experiment will be described in detail with reference to the following figure.

  As shown in FIG. 4, an intermediate film 22 that is thin enough to prevent distortion is sandwiched between the first window glass 21 and the second window glass 23. The double image was observed while the curvature radius R1 of the first window glass 21 was fixed and the curvature radius R2 of the second window glass 23 was changed.

  The double image was observed by measuring the distance t from the real image to the virtual image. The case where the virtual image was generated above the real image was defined as + (plus), and the case where the virtual image was generated below the real image was defined as-(minus). That is, when it is 0, the real image and the virtual image coincide with each other, which is preferable.

  As shown in FIG. 5, in Experiment No. 1 (“Real 1” in the figure, the same applies hereinafter) with R2 = R1 (= 8000 mm), t was not 0 and a double image was generated. Since a double image has occurred, it is necessary to change the value of R2 and change the direction in which the virtual image is reflected.

In Experiment No. 2, R2 was reduced, and in Experiment No. 3, R2 was increased, and the same experiment was performed.
The taper angle θn of the intermediate film at this time was 0.48 mRad.
The results of Experiment Nos. 2 and 3 are illustrated in the following figure.

As shown in FIG. 6, in the experiment number 2 in which R2 is reduced, the distance t between the real image and the virtual image is longer than that in the case of the experiment number 1.
On the other hand, in the experiment number 3 in which R2 is increased, the distance t between the real image and the virtual image is closer than in the case of the experiment number 1.

  If the distance t between the real image and the virtual image is 0, a double image is not generated. From the results so far, it can be considered that t is reduced by increasing R2. In the experiment number 4 and later, the magnitude of R2 was further increased as compared with the experiment number 3, and an experiment was conducted as to whether t would be zero. Details will be described in the next figure.

  As shown in FIG. 7, R2 was gradually increased over the experiment numbers 4-6. As R2 increased, the distance t between the real image and the virtual image decreased, approaching 0 most in Experiment No. 5, and turning negative in Experiment No. 6.

  It was found that the distance t between the real image and the virtual image is shortened by increasing R2. Whether or not this was true even when the taper angle θn was further reduced was examined using Experiment Nos. 7-12. This will be described in detail in the next figure.

As shown in FIG. 8, the same tendency as in Experiment Nos. 1 to 6 was obtained even in Experiment Nos. 7 to 12 in which the taper angle θn was 0.38 mRad.
The following figure summarizes the results.

  As shown in FIG. 9, the line 25 is a result of Experiment Nos. 1 to 6 in which the taper angle θn is 0.48 mRad. In Experiment Nos. 1 to 6, a point where the distance t between the real image and the virtual image was 0 was passed between Experiment Nos. 5 and 6.

  The line 26 is the result of the experiment numbers 7-12 which made taper angle (theta) n 0.38 mRad. In Experiment Nos. 7 to 12, a point where the distance t between the real image and the virtual image was 0 was passed between Experiment Nos. 11 and 12.

  When the distance t between the real image and the virtual image is 0, no double image is generated. That is, even when an intermediate film having a taper angle θn that does not cause distortion is used, the curvature radius R2 in the height direction of the second window glass is set to the curvature radius R1 in the height direction of the first window glass. It was found that a double image can be prevented by making it larger than that.

  In order to investigate the certainty of this, a further experiment was conducted by changing the curvature radius R1 of the first window glass after setting the taper angle θn to 0.48 mRad. Details are described in the following figure.

  As shown in FIG. 10, the line 27 shows the results of experiment numbers 13 to 16 with R1 = 6000 mm. Line 28 shows the results of experiment numbers 17-21 with R1 = 10000 mm.

Similar results were obtained when R1 was changed.
That is, even when an intermediate film having a taper angle θn that does not cause distortion is used, the curvature radius R2 in the height direction of the second window glass is set to the curvature radius R1 in the height direction of the first window glass. By making it larger than this, double images can be prevented.
The reason for this result will be described with reference to the following figure.

  As shown in the comparative example of FIG. 11A, when the curvature radius R1 of the first window glass 31 and the curvature radius R2 of the second window glass 33 are the same, the thickness is such that distortion does not occur. By using the intermediate film 32, a double image may be generated.

  As shown in the embodiment of (b), when the curvature radius R2 of the second window glass 43 is larger than the curvature radius R1 of the first window glass 41, the intermediate film 42 has a thickness that does not cause distortion. Even if is used, a double image is not generated.

  As can be seen from the drawings in which the comparative example and the example of (c) are overlapped, the second window glass 43 is raised with respect to the first window glass 41 by increasing the curvature radius of the second window glass 43. Provided. By raising the second window glass 43 with respect to the first window glass 41, the angle at which the virtual image is reflected changes. It is thought that the virtual image could be superimposed on the real image by changing the reflection angle of the virtual image.

  In addition, it is desirable that the value of R2-R1 is 800 mm or more. Considering the tolerance that can occur in the first window glass 43 and the second window glass 44, the effect of the present invention is most exhibited when the value of R2-R1 is 800 mm or more.

  Moreover, it is desirable that the value of R2-R1 is less than 10000 mm because of the size of the laminated glass for vehicles that is usually used. If it is less than 10000 mm, the 2nd window glass 44 can be easily adhere | attached on the 1st window glass 43 by the conventional method.

Further, in consideration of the size of the glass usually used and the thickness of the intermediate film necessary for bonding these glasses with a predetermined strength, the value of R2-R1 is preferably 800 or more and less than 5000.
The laminated glass for vehicles according to the present invention will be described with reference to the following figure.

  As shown in FIG. 12, the laminated glass 50 for a vehicle includes a first window glass 51 provided on the vehicle interior side, an intermediate film 52 that is bonded to the vehicle exterior side of the first window glass 51 and has a wedge shape in cross section, The second window glass 53 is provided outside the intermediate film 52 and bonded to the intermediate film 52. Information from the head-up display device 54 is projected onto the first window glass 51, and the second window glass 53 The curvature radius R2 in the height direction is larger than the curvature radius R1 in the height direction of the first window glass 51.

  Such a vehicular laminated glass 50 is provided with an intermediate film 52 having a predetermined thickness that does not cause distortion, and a first curvature radius R1 is set in accordance with the thickness of the intermediate film 52. A window glass 51 and a second window glass 53 having a radius of curvature R2 in the height direction are prepared. The relationship between R1 and R2 is obtained in advance by experiments, and the first window glass 51 and the second window glass 53 have values that do not generate double images.

  By changing the curvature radius R2 of the second window glass 53, the direction in which the virtual image is reflected changes. On the other hand, by making the intermediate film 52 thin, it is possible to prevent distortion that occurs in the vicinity of the glass upper end portion 55.

  An intermediate film 52 that is thin enough to prevent distortion is employed. A double image that can be generated by thinning the intermediate film 52 is prevented by increasing the radius of curvature R2 of the second window glass 53 and changing the direction in which the virtual image is reflected. A double image can be prevented while preventing distortion.

  In addition, the interlayer film for laminated glass for vehicles according to the present invention may be any type of interlayer film having a sound insulation function, an interlayer film having a heat insulation function, or a combination thereof. Yes, it is not limited to these.

  The laminated glass for vehicles of the present invention is suitable for a four-wheeled vehicle.

  DESCRIPTION OF SYMBOLS 50 ... Laminated glass for vehicles, 51 ... 1st window glass, 52 ... Intermediate film, 53 ... 2nd window glass, 54 ... Head-up display apparatus.

Claims (1)

A first window glass provided on the vehicle interior side, an intermediate film bonded to the vehicle outer side of the first window glass and having a wedge shape in cross section, and a first window glass provided on the vehicle outer side of the intermediate film and bonded to the intermediate film It consists of two window glasses, and information from the head-up display device is laminated glass for vehicles projected on the first window glass,
A laminated glass for vehicles, wherein a curvature radius in a height direction of the second window glass is larger than a curvature radius in a height direction of the first window glass.

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