JP2023043115A - windshield - Google Patents

Abstract

To provide a windshield that enables heat generation to allow an information acquisition device to accurately obtain information.SOLUTION: The present invention is an automotive windshield on which an information acquisition device can be disposed, the information acquisition device acquiring information from the outside of the vehicle by emitting and/or receiving light, the windshield comprising an outer glass plate, an inner glass plate disposed to oppose the outer glass plate, and an intermediate film disposed between the outer glass plate and the inner glass plate, wherein the intermediate film comprises a heat generation layer disposed at a position corresponding to an information acquisition area which opposes the information acquisition device and transmits light and a pair of busbars configured to feed power to the heat generation layer, the heat generation layer being formed to extend in a first direction and a second direction orthogonal to the first direction with the heat generation layer formed to be shorter in the first direction than in the second direction, and the pair of busbars being respectively disposed at the ends of the heat generation layer in the first direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to windshields.

In recent years, the safety performance of automobiles has been dramatically improved, and one of them is to avoid collision with the vehicle ahead by sensing the distance to the vehicle ahead and the speed of the vehicle ahead. A brake activated safety system has been proposed. Such systems measure the distance to the vehicle in front using a laser radar or camera. A laser radar and a camera are generally placed inside a windshield, and perform measurement by irradiating light such as infrared light forward (for example, Patent Document 1).

As described above, a measuring device such as a laser radar and a camera is arranged on the inner surface side of the glass plate that constitutes the windshield, and irradiates and receives light through the glass plate. However, on cold days or in cold regions, the glass plate may fog up or freeze. However, if the glass plate becomes cloudy, there is a risk that light cannot be emitted or received accurately from the measurement device. As a result, the inter-vehicle distance may not be calculated accurately.

Such a problem is not limited to inter-vehicle distance measuring devices, but can occur in general information acquisition devices that acquire information from outside the vehicle by receiving light, such as rain sensors, light sensors, and optical beacons.

JP-A-2006-96331

In order to solve the above problem, it has been proposed to place a heating wire in the area through which the light passes. However, in this region, sufficient heat generation is required for accurate information acquisition by the information acquisition device, but the required heat generation cannot be obtained simply by arranging the heating wire. SUMMARY OF THE INVENTION An object of the present invention is to provide a windshield capable of generating heat so that information can be obtained accurately by an information obtaining device.

Section 1. A windshield of an automobile in which an information acquisition device that acquires information from outside the vehicle by irradiating and/or receiving light can be arranged,
an outer glass plate;
an inner glass plate arranged to face the outer glass plate;
an intermediate film disposed between the outer glass plate and the inner glass plate;
with
The intermediate film is
a heating layer facing the information acquisition device and arranged at a position corresponding to the information acquisition region through which the light passes;
a pair of bus bars configured to supply power to the heating layer;
with
The heat generating layer is formed to extend in a first direction and a second direction orthogonal to the first direction,
The length of the heat generating layer in the first direction is shorter than the length in the second direction,
The windshield, wherein the pair of bus bars are arranged at both ends of the heat generating layer in the first direction.

Section 2. further comprising a shielding layer laminated on at least one of the outer glass plate and the inner glass plate and having an opening formed at a position corresponding to the information acquisition area;
Item 2. The windshield according to item 1, wherein the pair of bus bars are arranged so as to be covered with the shielding layer outside the opening.

Item 3. Item 3. The windshield according to Item 2, wherein the distance between the edge of the opening and the bus bar is 8 mm or more in the first direction.

Section 4. 4. The windshield according to any one of Items 1 to 3, wherein t/W is 0.01 or less, where t (mm) and W (mm) are the thickness and width of each bus bar.

Item 5. Item 5. The windshield according to any one of Items 1 to 4, wherein the heat generating layer has a thickness of 310 µm or less.

Item 6. Item 6. The windshield according to any one of Items 1 to 5, wherein the heat generating layer is arranged outside the test area A defined by JIS R3212.

Item 7. Item 7. The windshield according to any one of Items 1 to 6, wherein the intermediate film further includes a functional film surrounding the heat generating layer.

Item 8. Item 8. The windshield according to Item 7, wherein the difference in thickness between the functional film and the heat generating layer is 310 μm or less.

Item 9. Item 9. A windshield according to Item 7 or 8, wherein the functional film is an optical film.

Item 10. Item 10. The windshield according to any one of Items 1 to 9, wherein the heat generating layer is formed of a transparent conductive film.

Item 11. Item 10. The windshield according to any one of Items 1 to 9, wherein the heat generating layer includes a base sheet and a plurality of heating wires connecting the bus bars.

According to the windshield of the present invention, it is possible to generate heat so that the information acquisition device can acquire information accurately.

It is a top view showing one embodiment of a windshield concerning the present invention. FIG. 2 is a cross-sectional view showing a state in which the windshield of FIG. 1 is attached to a vehicle; 2 is an enlarged plan view of the vicinity of a photographing window of the windshield of FIG. 1; FIG. 4 is a cross-sectional view taken along line AA of FIG. 3; FIG. 1 is a block diagram of an in-vehicle system; FIG. FIG. 10 is a diagram showing deformation of the glass plate when the distance between the busbars is wide; FIG. 10 is a diagram showing deformation of the glass plate when the interval between busbars is narrow; FIG. 11 is an enlarged plan view showing another example of the vicinity of the photographing window of the windshield of FIG. 1; FIG. 4 is a plan view showing another example of the windshield according to the present invention; FIG. 10 is a cross-sectional view of the windshield of FIG. 9 near a photographing window; FIG. 4 is a plan view showing another example of bus bars and wiring; FIG. 4 is a plan view showing another example of bus bars and wiring; FIG. 2 is a plan view of Examples 1 to 4; FIG. 5 is a plan view of Comparative Examples 1 to 3; 4 is a diagram showing deformation of the glass plates of Example 1 and Comparative Example 1. FIG. FIG. 4 is a diagram showing deformation of the glass plates of Examples 1 and 2; It is a side view which shows the measuring method of perspective distortion. 4 is a plan view showing a target; FIG. 5 is a graph showing the relationship between the thickness of a heat generating layer and perspective distortion. 10 is a graph showing the relationship between the thickness of the heat generating layer and perspective distortion in Examples 3 and 4. FIG. 10 is a graph showing the distance between the imaging window and the busbar when perspective distortion of 400 mdpt occurs in Examples 3 and 4. FIG.

An embodiment of a windshield according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of the windshield, and FIG. 2 is a sectional view showing the windshield of FIG. 1 attached to a vehicle. For convenience of explanation, the vertical direction in FIG. 1 will be referred to as "vertical", "vertical", and "longitudinal", and the horizontal direction in FIG. 1 will be referred to as "left and right". FIG. 1 illustrates the windshield viewed from the inside of the vehicle. That is, the far side of the paper surface of FIG. 1 is the outside of the vehicle, and the front side of the paper surface of FIG. 1 is the inside of the vehicle.

As shown in FIGS. 1 and 2, the windshield 1 includes a substantially rectangular laminated glass 10 and is installed on the vehicle body in an inclined state. The windshield 1 also comprises an outer glass plate 11, an inner glass plate 12, and an intermediate film 13 arranged between the glass plates 11,12. A mask layer 110 is laminated on each of the vehicle-interior surfaces of the outer glass plate 11 and the inner glass plate 12 . A photographing device 2 having a built-in camera for photographing the situation outside the vehicle is attached to the mask layer 110 via a bracket (not shown). A photographing window 113 is provided in the mask layer 110 at a position corresponding to the photographing device 2 , and the photographing device 2 can photograph the situation outside the vehicle through the photographing window 113 .

An image processing device 3 is connected to the photographing device 2 , and the photographed image acquired by the photographing device 2 is processed by this image processing device 3 . The photographing device 2 and the image processing device 3 constitute an in-vehicle system 5 (see FIG. 5), and the in-vehicle system 5 can provide various information to passengers according to the processing of the image processing device 3. .

<1. Overview of the windshield>
<1-1. Glass plate>
The outer glass plate 11 and the inner glass plate 12 can be made of known glass plates, and can be made of heat-absorbing glass, general clear glass, green glass, or UV green glass. However, these glass plates 11 and 12 must achieve visible light transmittance that meets the safety standards of the countries where automobiles are used. For example, the outer glass plate 11 can ensure a necessary solar absorptivity, and the inner glass plate 12 can be adjusted so that the visible light transmittance satisfies safety standards. Examples of clear glass, heat-absorbing glass, and soda-lime-based glass are shown below.

(clear glass)
SiO ₂ : 70-73% by mass
Al ₂ O ₃ : 0.6 to 2.4% by mass
CaO: 7 to 12% by mass
MgO: 1.0 to 4.5% by mass
R ₂ O: 13-15% by mass (R is an alkali metal)
Total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ : 0.08 to 0.14% by mass

(heat-absorbing glass)
The composition of the heat-absorbing glass is, for example, based on the composition of the clear glass, the ratio of total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ is 0.4 to 1.3% by mass, and CeO ₂ is 0 to 2% by mass, the ratio of TiO ₂ is 0 to 0.5% by mass, and the framework components of the glass (mainly SiO ₂ and Al ₂ O ₃ ) are T—Fe ₂ O ₃ and CeO. ₂ and TiO ₂ increments.

(Soda-lime-based glass)
SiO ₂ : 65-80% by mass
Al ₂ O ₃ : 0 to 5% by mass
CaO: 5 to 15% by mass
MgO: 2% by mass or more NaO: 10 to 18% by mass
K ₂ O: 0 to 5% by mass
MgO + CaO: 5 to 15% by mass
Na ₂ O + K ₂ O: 10 to 20% by mass
_SO3 : 0.05 to 0.3% by mass
_B2O3 : 0 to 5% _by mass
Total iron oxide converted to Fe ₂ O ₃ (T-Fe ₂ O ₃ ): 0.02 to 0.03% by mass

The thickness of the laminated glass 10 according to the present embodiment is not particularly limited, but from the viewpoint of weight reduction, the total thickness of the outer glass plate 11 and the inner glass plate 12 may be 2.4 to 5.0 mm. It is preferably 2.6 to 3.4 mm, particularly preferably 2.7 to 3.2 mm. Thus, in order to reduce the weight, it is necessary to reduce the total thickness of the outer glass plate 11 and the inner glass plate 12. For example, the thickness of the outer glass plate 11 and the inner glass plate 12 can be determined as follows.

The outer glass plate 11 is mainly required to have durability and impact resistance against obstacles from the outside. is necessary. On the other hand, the larger the thickness, the greater the weight, which is not preferable. From this point of view, the thickness of the outer glass plate 11 is preferably 1.0 to 3.0 mm, more preferably 1.6 to 2.3 mm. Which thickness to use can be determined according to the use of the glass.

The thickness of the inner glass plate 12 can be made equal to that of the outer glass plate 11, but can be made smaller than the thickness of the outer glass plate 11 in order to reduce the weight of the laminated glass 10, for example. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.0 mm, more preferably 0.8 to 1.8 mm, and more preferably 0.8 to 1.6 mm. Especially preferred. Further, it is preferably 0.8 to 1.3 mm. Which thickness to use for the inner glass plate 12 can also be determined according to the use of the glass.

Further, the shapes of the outer glass plate 11 and the inner glass plate 12 according to this embodiment may be curved shapes. However, when the glass plates 11 and 12 are curved, the sound insulation performance is degraded as the amount of overlap increases. The amount of doubling is an amount that indicates the amount of bending of the glass plate. It is defined as the amount of doubling D.

In addition, the curved glass plate does not have a large difference in sound transmission loss (STL) when the double amount D is in the range of 30 to 38 mm, but compared to the flat glass plate, the frequency is 4000 Hz or less. It can be seen that the sound transmission loss is reduced in the band. Therefore, when producing a curved glass plate, the overlap amount D is preferably as small as possible. Specifically, the overlap amount D is preferably less than 30 mm, more preferably less than 25 mm, and particularly preferably less than 20 mm.

Here, an example of a method for measuring the thickness when the glass plate is curved will be described. First, the measurement positions are two points above and below a center line extending vertically from the center of the glass plate in the horizontal direction. Although the measuring instrument is not particularly limited, for example, a thickness gauge such as SM-112 manufactured by Teclock Co., Ltd. can be used. At the time of measurement, the curved surface of the glass plate is placed on a flat surface, and the edge of the glass plate is held between the thickness gauges.

＊１，主成分：酸化銅、酸化クロム、酸化鉄及び酸化マンガン
＊２，主成分：ホウケイ酸ビスマス、ホウケイ酸亜鉛 <1-2. Mask layer>
As shown in FIGS. 1 and 2, a mask layer 110 made of dark-colored ceramic such as black is laminated on the periphery of the windshield 1 . This mask layer 110 shields the field of view from inside or outside the vehicle, and is laminated along the outer edge of the windshield 1. The peripheral edge portion 111 corresponds to the upper side of the windshield 1. and a protrusion 112 extending downward from near the center of the portion. A rectangular photographing window 113 is formed in the projecting portion 112 . The photographing window 113 is a portion where the mask layer 110 is not formed, and is a portion through which the inside and outside of the windshield 1 are transmitted. The photographing device 2 described above is arranged inside the vehicle and acquires information from outside the vehicle through the photographing window 113 . The mask layer 110 can be made of various materials such as ceramics, and can have, for example, the following composition.

*1, Main ingredients: copper oxide, chromium oxide, iron oxide and manganese oxide *2, Main ingredients: bismuth borosilicate, zinc borosilicate

The ceramic can be formed by screen printing, but can also be produced by transferring a transfer film for firing to a glass plate and firing the film. When screen printing is adopted, for example, polyester screen: 355 mesh, coat thickness: 20 μm, tension: 20 Nm, squeegee hardness: 80 degrees, mounting angle: 75 degrees, printing speed: 300 mm / s. A ceramic can be formed by drying at 150° C. for 10 minutes.

The mask layer 110 can also be formed by laminating ceramics or by attaching a dark-colored resin-made shielding film.

<1-3. Intermediate Film>
Next, the intermediate film will be described with reference to FIGS. 3 and 4. FIG. 3 is an enlarged plan view of the vicinity of the photographing window in the windshield of FIG. 1, and FIG. 4 is a sectional view taken along the line AA of FIG. As shown in FIGS. 3 and 4, the intermediate film 13 includes a transparent first adhesive layer 131 adhered to the outer glass plate 11, a transparent second adhesive layer 132 adhered to the inner glass plate 12, and a transparent adhesive layer 132 adhered to the inner glass plate 12. and a heat-generating layer 133 arranged between both adhesive layers 131 and 132 .

The first adhesive layer 131 and the second adhesive layer 132 are not particularly limited as long as they are adhered to the respective glass plates 11 and 12 by fusion bonding, but examples include polyvinyl butyral resin (PVB) and ethylene vinyl acetate resin. (EVA) or the like. In general, the hardness of a polyvinyl acetal resin is controlled by (a) the degree of polymerization of polyvinyl alcohol as a starting material, (b) the degree of acetalization, (c) the type of plasticizer, and (d) the addition ratio of the plasticizer. can be done.

Although the thickness of the first adhesive layer 131 and the second adhesive layer 132 is not particularly limited, it is preferably 0.05 to 2.0 mm, more preferably 0.1 to 1.0 mm. However, the thicknesses of both adhesive layers 131 and 132 may be the same or different.

Also, the total thickness of both adhesive layers 131 and 132 is preferably 0.6 mm or more. This is to ensure penetration resistance and the like as defined in JIS R3211 and R3212, for example, in the windshield.

Since the first adhesive layer 131 and the second adhesive layer 132 are melted and integrated in an autoclave, which will be described later, the boundary between the two adhesive layers 131 and 132 cannot be visually recognized on the completed windshield 1 . However, for convenience of explanation, the intermediate film shown in FIG.

The heat generating layer 133 is formed of a transparent conductive film arranged at a position corresponding to the photographing window 113 . More specifically, the heat generating layer 133 is formed slightly larger than the photographing window 113 and arranged so as to cover the photographing window 113 . The heat generation layer 133 is formed in a rectangular shape whose length in the horizontal direction is shorter than in the vertical direction, and bus bars 134 are laminated on both the left and right ends thereof with an adhesive such as solder. Each bus bar 134 is for supplying power to the heat generating layer 133 and extends upward on both sides of the heat generating layer 133 . A wiring 139 is connected to the upper end of each bus bar 134 , and the upper end of each wiring 139 protrudes from the upper sides of the glass plates 11 and 12 . A positive electrode and a negative electrode of a power source (not shown) are connected to each wiring 139 . Moreover, since each bus bar 134 is laminated on both the left and right ends of the heat generation layer 133 , it is hidden by the mask layer 110 and cannot be seen through the photographing window 113 .

The transparent conductive film forming heat generating layer 133 is configured to generate heat when a voltage is applied by both bus bars 134 . Such transparent conductive films include, for example, ITO, _SnO2 doped with Sb and F, zinc oxide doped with Al and Ga, TiO2 doped with Nb, TCO (Transparent Conductive Oxide) such as tungsten oxide, and the like. and a metal film are laminated on a base film. Incidentally, the resistance of the TCO can be, for example, 3 to 160Ω/□. This is because if the resistance exceeds 160 Ω/□, heat generation will be insufficient, and the anti-fogging or de-icing performance will be insufficient. On the other hand, if it is lower than 3 Ω/□, there is a risk of abnormal heat generation and excessive power consumption, which may lead to breakage of the glass plate and adverse effects on devices such as sensors. The base film is formed of a transparent resin film, and can be formed of, for example, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, or acrylic resin.

The thickness of the heat generating layer 133 is, for example, preferably 38-310 μm, more preferably 50-125 μm. This is because if the thickness of the heat generating layer 133 is too small, handling becomes difficult, while if the thickness of the heat generating layer 133 is too large, perspective distortion increases. Moreover, if the heat generation layer 133 is too thick, a step may occur, and the glass plates 11 and 12 may be easily deformed.

The bus bar 134 is not particularly limited as long as it is made of a conductive material, and examples thereof include copper, silver, gold, and platinum. Although the width and thickness of the bus bar 134 are not particularly limited, for example, the width of the bus bar 134 is preferably 3 to 12 mm, and the thickness of the bus bar is preferably 10 to 100 μm. Further, when the width and thickness of bus bar 134 are W (mm) and t (mm), respectively, t/W is preferably 0.01 or less. Furthermore, the distance s (see FIG. 4) between the bus bar 134 and the photographing window 113 is preferably 8 mm or more, more preferably 15 mm or more. This is because the glass plates 11 and 12 are likely to be deformed due to the step caused by the bus bar 134, so it is preferable that the bus bar 134 and the photographing window 113 are separated as much as possible.

<2. In-vehicle system>
Next, the in-vehicle system 5 including the photographing device 2 and the image processing device 3 will be described with reference to FIG. FIG. 5 illustrates the configuration of the in-vehicle system 5. As shown in FIG. As shown in FIG. 5 , an in-vehicle system 5 according to this embodiment includes the photographing device 2 and an image processing device 3 connected to the photographing device 2 .

The image processing device 3 is a device that processes the captured image acquired by the imaging device 2 . The image processing apparatus 3 has, for example, general hardware such as a storage unit 31, a control unit 32, an input/output unit 33, etc., which are connected via a bus as a hardware configuration. However, the hardware configuration of the image processing device 3 may not be limited to such an example, and regarding the specific hardware configuration of the image processing device 3, addition or omission of components may be made as appropriate according to the embodiment. and can be added.

The storage unit 31 stores various data and programs used in the processing executed by the control unit 32 (not shown). The storage unit 31 may be realized by, for example, a hard disk, or may be realized by a recording medium such as a USB memory. Also, the various data and programs stored in the storage unit 31 may be acquired from a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). Furthermore, the storage unit 31 may be called an auxiliary storage device.

As described above, the laminated glass 10 is arranged in an inclined posture with respect to the vertical direction and is curved. Then, the photographing device 2 photographs the situation outside the vehicle through such laminated glass 10 . Therefore, the photographed image acquired by the photographing device 2 is deformed according to the orientation, shape, refractive index, optical defects, and the like of the laminated glass 10 . In addition, an aberration specific to the camera lens of the photographing device 2 is also added. Therefore, the storage unit 31 may store correction data for correcting an image deformed by such aberrations of the laminated glass 10 and the camera lens.

The control unit 32 includes one or more processors such as a microprocessor or a CPU (Central Processing Unit), and peripheral circuits (ROM (Read Only Memory), RAM (Random Access Memory), interface circuits used for the processing of this processor. etc.). ROM, RAM, etc. may be called a main storage device in the sense that they are arranged in an address space handled by the processor within the control unit 32 . The control unit 32 functions as an image processing unit 321 by executing various data and programs stored in the storage unit 31 .

The image processing unit 321 processes captured images acquired by the imaging device 2 . The processing of the captured image can be appropriately selected according to the embodiment. For example, the image processing unit 321 may recognize the subject appearing in the captured image by analyzing the captured image by pattern matching or the like. In this embodiment, since the photographing device 2 photographs the situation in front of the vehicle, the image processing unit 321 further determines whether or not a creature such as a human being is photographed in front of the vehicle based on the subject recognition. good too. Then, when a person appears in front of the vehicle, the image processing section 321 may output a warning message by a predetermined method. Further, for example, the image processing unit 321 may apply predetermined processing to the captured image. Then, the image processing unit 321 may output the processed captured image to a display device (not shown) such as a display connected to the image processing device 3 .

The input/output unit 33 is one or a plurality of interfaces for transmitting/receiving data to/from a device existing outside the image processing device 3 . The input/output unit 33 is, for example, an interface for connecting to a user interface, or an interface such as a USB (Universal Serial Bus). Note that in the present embodiment, the image processing device 3 is connected to the imaging device 2 via the input/output unit 33 and acquires an image captured by the imaging device 2 .

Such an image processing apparatus 3 may be a general-purpose apparatus such as a PC (Personal Computer), a tablet terminal, or the like, as well as an apparatus designed exclusively for the service provided.

The imaging device 2 is attached to a bracket (not shown), and the bracket is attached to the mask layer 110 . Therefore, in this state, the attachment of the imaging device 2 to the bracket and the attachment of the bracket to the mask layer are adjusted so that the optical axis of the camera of the imaging device 2 passes through the imaging window 113 . A cover (not shown) is attached to the bracket so as to cover the imaging device 2 . Therefore, the photographing device 2 is arranged in a space surrounded by the laminated glass 10, the bracket, and the cover, so that it cannot be seen from the inside of the vehicle, and only a part of the photographing device 2 can be seen from the outside of the vehicle through the photographing window 113. It's not supposed to. The photographing device 2 and the input/output unit 33 are connected by a cable (not shown). This cable is pulled out from the cover and connected to the image processing device 3 arranged at a predetermined position inside the vehicle. .

<3. Windshield manufacturing method>
Next, an example of a method for manufacturing the windshield configured as described above will be described. First, a method for manufacturing the laminated glass 10 will be described.

First, the mask layer 110 described above is laminated on at least one of the flat plate-like outer glass plate 11 and inner glass plate 12 . Next, these glass plates 11 and 12 are molded so as to be curved. A molding method is not particularly limited, and a known method can be adopted. For example, after a flat glass plate passes through a heating furnace, it can be molded into a curved shape by pressing with an upper mold and a lower mold. Alternatively, a flat outer glass plate and an inner glass plate are overlapped, placed on a frame mold, and passed through a heating furnace. As a result, both glass sheets are softened and formed into a curved shape by their own weight.

After the outer glass plate 11 and the inner glass plate 12 are thus formed into a curved shape, the above-described intermediate film 13 is sandwiched between the outer glass plate 11 and the inner glass plate 12, and then wrapped in a rubber bag. and pre-adhered at about 70 to 110° C. while vacuuming. The intermediate film 13 sandwiches the heat generating layer 133, the bus bar 134 and the wiring 139 between the adhesive layers 131 and 132 described above. Other pre-bonding methods are possible. For example, the intermediate film 13 is sandwiched between the outer glass plate 11 and the inner glass plate 12 and heated at 45 to 65° C. in an oven. Subsequently, this laminated glass is pressed with rolls at 0.45 to 0.55 MPa. Next, this laminated glass is heated again in an oven at 80 to 105° C., and then pressed again with a roll at 0.45 to 0.55 MPa. Thus, pre-bonding is completed.

Next, final adhesion is performed. The pre-bonded laminated glass is subjected to main bonding by an autoclave, for example, at 8 to 15 atmospheres and 100 to 150°C. Specifically, for example, the main adhesion can be performed under the conditions of 14 atmospheric pressure and 145°C. Thus, the laminated glass 10 according to this embodiment is manufactured.

<4. Features>
(1) Since the heating layer 133 generates heat when the bus bar 134 supplies power, the portions of both the glass plates 11 and 12 corresponding to the photographing window 113 can be heated. Therefore, both the glass plates 11 and 12 can be prevented from being fogged, and the image of the outside of the vehicle can be appropriately photographed by the photographing device 2. - 特許庁

(2) In the present embodiment, the heat generation layer 133 is formed in a rectangular shape in which the length in the left-right direction (first direction) is shorter than the length in the up-down direction (second direction). are arranged at the upper and lower ends of the heat generating layer 133, the distance between the two bus bars 134 is shorter. Therefore, the following effects can be obtained.

As shown in FIG. 6, if the distance between the busbars 134 is large, the busbars 134 will become a fulcrum when the two glass plates 11 and 12 are pressed by the autoclave, for example, if the rigidity of the glass plates is constant. Therefore, in the outer glass plate 11, the portion between the two bus bars 134 is flexed toward the heat generation layer side by a large amount. As a result, perspective distortion of an image formed by light passing through the photographing window 113 arranged between the bus bars 134 becomes large, and there is a possibility that an appropriate image cannot be generated by the image processing described above. On the other hand, as shown in FIG. 7, when the distance between the bus bars 134 is small, the portion of the outer glass plate 11 between the bus bars 134 can be flexed toward the heat generating layer 133 by a small amount. As a result, an appropriate image can be generated by the image processing described above. Therefore, in the present embodiment, the heat generation layer 133 whose length in the horizontal direction is shorter than that in the vertical direction is used, and the bus bars 134 are arranged at both ends of the heat generation layer 133 in the horizontal direction. can be made smaller. The inner glass plate 12 is also deformed in the same manner as the outer glass plate 11, but the explanation is omitted here.

<5. Variation>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the invention. Note that the following modified examples can be combined as appropriate.

<5-1>
Although the heat generation layer 133 is formed of a transparent conductive film in the above embodiment, the configuration of the heat generation layer is not limited to this. For example, as shown in FIG. 8, a pair of bus bars 134 are arranged at both ends of a base sheet 135 having the same shape as the heat generating layer 133 described above. A plurality of heating wires 136 are arranged in parallel on the base sheet 135 so as to connect both bus bars 134 . By doing so, both the glass plates 11 and 12 can be heated by the heating wire 136, and fogging can be prevented. The base sheet 135 can be made of, for example, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, or acrylic resin. The outer diameter of the heating wire 136 is preferably smaller than the thickness of the bus bar 134, for example 5 to 30 μm.

<5-2>
As shown in FIGS. 9 and 10, a functional film 137 can also be arranged inside the intermediate film 13 so as to surround the heat generating layer 133 . By arranging such a functional film 137 , it is possible to reduce a step occurring around the heat generating layer 133 inside the intermediate film 13 . Thereby, the deformation of the glass plates 11 and 12 can be suppressed, and the occurrence of perspective distortion can be suppressed. Although the functional film is not particularly limited, for example, optical films such as reflective films for head-up displays and heat reflective films can be used. The thickness of the functional film 137 is preferably the same as that of the heat-generating layer 133. For example, the difference in thickness between the heat-generating layer 133 and the functional film 137 is preferably 310 μm or less. A gap may be provided between the functional film 137 and the heat generating layer 133, or at least a part of both 137 and 133 may be in contact with each other.

<5-3>
In addition to the above embodiment, the mask layer 110 can take various forms such as only the inner surface of the outer glass plate 11 or only the inner surface of the inner glass plate 12, for example. Moreover, the shape of the mask layer 110 is an example, and the configuration is not particularly limited, and the shape can be changed as appropriate depending on the equipment provided. When the mask layer 110 is provided on both the outer glass plate 11 and the inner glass plate 12, the mask layers 110 may have the same shape or different shapes. For example, the mask layer 110 laminated on one of the glass plates 11 and 12 can be composed only of the protrusions 112 .

Also, the position of the imaging window 113 in the mask layer 110 is not particularly limited, and can be changed as appropriate. However, the position where the photographing window 113 is provided is preferably outside the test area A specified in JIS R 3212 (1998, "Automotive safety glass test method").

<5-4>
In the above embodiment, the heat generation layer 133 whose horizontal length is smaller than its vertical length is used. A heat generating layer 133 with a small σ can also be used. In this case, the busbars 134 are arranged at the upper and lower ends of the heat generating layer 133, respectively. Also, as shown in FIG. 11, one wiring 139 is formed to extend from the left end of one (upper) bus bar 134 to the upper side of the glass plates 11 and 12, and the other wiring 139 is formed to extend from the other (lower) bus bar 134 can be formed so as to extend from the right end of the bus bar 134 to the upper sides of the glass plates 11 and 12 . Alternatively, as shown in FIG. 12, both wirings 139 can be formed to extend from the same side (right end) of each bus bar 134 to the upper sides of the glass plates 11 and 12 . Moreover, the bus bar 134 may be laminated on the heat generating layer 133 or may be adjacent to the heat generating layer 133 .

<5-6>
In the above embodiment, the wiring 139 is connected to the bus bar 134, but these may be integrated to extend the bus bar 134 and wiring 139 to the ends of the glass plates 11 and 12, or to extend the wiring halfway to the ends. , the wires can be connected to each other and pulled out to the edge of the glass.

<5-7>
In the above embodiment, the heat generation layer 133 is formed in a rectangular shape, but is not limited thereto, and in two orthogonal directions, the maximum length of one of them is shorter than the maximum length of the other. If it is Therefore, the heating layer 133 may be trapezoidal, for example. Therefore, both bus bars 134 do not necessarily have to be arranged in parallel, and may be arranged obliquely depending on the shape of the heat generating layer 133 .

<5-8>
In the above embodiment, the pair of bus bars 134 are arranged on the heat generating layer 133, but instead of the heat generating layer, an optical layer or the like for changing the optical characteristics of the information acquisition area can be arranged. . In this case, by arranging the step forming members at both ends of the optical layer instead of the bus bars, it is possible to suppress the perspective distortion in the information-oriented area.

<5-9>
In the above embodiment, the information acquisition device of the present invention is exemplified by a photographing device, but the information acquisition device is not limited to this. It may be a device that acquires

Examples of the present invention will be described below. However, the present invention is not limited to the following embodiments.

<1. Examination of Deformation of Glass Plate>
Examples 1 and 2 and Comparative Example 1 below were produced. Here, for the sake of simplification, glass plate modules simulating the vicinity of the photographing window of the windshield were produced as Examples 1 and 2 and Comparative Examples 1 and 2. Examples 1 and 2 and Comparative Example 1 are composed of the following materials.

・Outer glass plate, inner glass plate: float glass, 300 mm x 300 mm, thickness 2 mm
- The first and second adhesive layers of the intermediate film: PVB, thickness 0.38 mm
Heat-generating layer: transparent conductive film obtained by coating ITO on a PET base film, 160 mm (horizontal) × 90 mm (vertical), thickness 125 μm (Example 1, Comparative Example 1), thickness 50 μm (Example 2)
・Bus bar: copper ribbon (fixed to the heating layer with low melting point solder), width 10 mm, thickness 50 μm,

FIG. 13 shows Examples 1 and 2, in which the bus bars are arranged at the upper and lower ends of the heat generating layer, respectively. FIG. 14 shows Comparative Example 1, in which the busbars are arranged at the left and right ends of the heat generating layer, respectively. The cross sections of Examples 1 and 2 and Comparative Example 1 are configured in the same manner as in FIG.

For Examples 1 and 2 and Comparative Example 1 produced as described above, the thickness of the glass plate was measured. Here, the thickness of the glass plate was measured at predetermined intervals from the upper edge on a line extending vertically in the center of the heat generating layer in the horizontal direction, and the difference from the smallest thickness was plotted, and the difference was plotted. created a graph. The graph in FIG. 15 shows Example 1 and Comparative Example 1. FIG. According to this graph, in Comparative Example 1, in which the interval between the busbars is wide, the deflection amount near the center of the heat generating layer is larger than in Example 1, in which the interval between the busbars is narrow. Therefore, if the distance between the busbars is wide, the glass plate tends to bend between them, which is considered to affect perspective distortion.

Moreover, the graph of FIG. 16 shows Example 1 and Example 2. FIG. According to this graph, the smaller the thickness of the heat generating layer, the smaller the deflection amount of the glass plate. This is because the heat-generating layer is located in a part of the glass plate, and the heat-generating layer is less deformed than the adhesive layer. It is considered that the bending of the glass plate becomes large at .

<2. Examination of Perspective Distortion>
Examples 3 and 4 and Comparative Examples 2 and 3 below were produced. Examples 3 and 4 and comparative examples 2 and 3 have substantially the same configurations as those in FIGS. 13 and 14, respectively. Moreover, these cross sections are configured in the same manner as in FIG. Examples 3 and 4 and Comparative Examples 2 and 3 are composed of the following materials.

・Outer glass plate, inner glass plate: float glass, 300 mm (vertical) x 500 mm (horizontal), thickness 2 mm
- The first and second adhesive layers of the intermediate film: PVB, thickness 0.38 mm
Heat-generating layer: transparent conductive film obtained by coating ITO on a PET base film, 290 mm (horizontal) × 150 mm (vertical), thickness 125 μm (Example 3, Comparative Example 2), thickness 50 μm (Example 4, Comparative Example) 3)
・Bus bar: copper ribbon (fixed to the heating layer with low melting point solder), width 10 mm, thickness 50 μm,

For Examples 3 and 4 and Comparative Examples 2 and 3 produced as described above, perspective distortion (optical power) was measured. As shown in FIG. 17, the glass plate module according to the example or the comparative example was placed between the camera and the target at an angle of 25 degrees from the horizontal. A lattice pattern as shown in FIG. 18 was formed on the target, and this target was photographed with a camera through Examples and Comparative Examples to measure perspective distortion. For perspective distortion, the focal length was calculated from the amount of deviation from the grid pattern of the target, and 1/(focal length) was defined as perspective distortion (mdpt).

FIG. 19 is a graph showing absolute values of perspective distortion in Examples 3 and 4 and Comparative Examples 2 and 3. FIG. According to the figure, if the thickness of the heat generating layer is the same, the see-through distortion is smaller in Examples 3 and 4 in which the distance between the busbars is narrower than in Comparative Examples 2 and 3. Further, it was found that perspective distortion increased as the thickness of the heat generating layer increased. As described above, if the thickness of the heat generating layer is large, the perspective distortion becomes large, but if the thickness of the heat generating layer is small, the heat generating layer tends to be deformed and is difficult to handle. Therefore, depending on the application, the thickness of the heat generating layer may have to be increased. In this case, the increase in perspective distortion can be suppressed by reducing the distance between the busbars.

By the way, it is considered that the absolute value of perspective distortion may interfere with image processing if it exceeds 400 mdpt. In this respect, as shown in FIG. 20, drawing the approximate straight lines of Examples 3 and 4, the thickness of the heat generating layer at which the perspective distortion becomes 400 mdpt is considered to be 310 μm. For this reason, the thickness of the heat generating layer is preferably 310 μm or less.

Next, the thickness of the heating layer and the distance between the bus bar and the imaging window (distance s in FIG. 4) were measured when the perspective distortion was 400 mdpt. The results are as shown in FIG. In Example 3, it was 13 mm, and in Example 4, it was 8 mm. Therefore, it was found that the distance between the bus bar and the photographing window should preferably be 8 mm or less in order to prevent the problem of perspective distortion.

10 Laminated glass 11 Outer glass plate 12 Inner glass plate 13 Intermediate film 131 First adhesive layer 132 Second adhesive layer 133 Heat generating layer 134 Bus bar

Claims (11)

A windshield of an automobile in which an information acquisition device that acquires information from outside the vehicle by irradiating and/or receiving light can be arranged,
an outer glass plate;
an inner glass plate arranged to face the outer glass plate;
an intermediate film disposed between the outer glass plate and the inner glass plate;
with
The intermediate film is
a heating layer facing the information acquisition device and arranged at a position corresponding to the information acquisition region through which the light passes;
a pair of bus bars configured to supply power to the heating layer;
with
The heat generating layer is formed to extend in a first direction and a second direction orthogonal to the first direction,
The length of the heat generating layer in the first direction is shorter than the length in the second direction,
The windshield, wherein the pair of bus bars are arranged at both ends of the heat generating layer in the first direction. further comprising a shielding layer laminated on at least one of the outer glass plate and the inner glass plate and having an opening formed at a position corresponding to the information acquisition area;
2. The windshield according to claim 1, wherein said pair of bus bars are arranged outside said opening so as to be covered by said shielding layer. 3. The windshield according to claim 2, wherein the distance between the edge of the opening and the busbar is 8 mm or more in the first direction. The windshield according to any one of claims 1 to 3, wherein t/W is 0.01 or less, where t (mm) and W (mm) are the thickness and width of each bus bar. The windshield according to any one of claims 1 to 4, wherein the heat generating layer has a thickness of 310 µm or less. The windshield according to any one of claims 1 to 5, wherein the heat generating layer is arranged outside the test area A defined by JIS R3212. The windshield according to any one of claims 1 to 6, wherein said intermediate film further comprises a functional film surrounding said heat generating layer. The windshield according to claim 7, wherein the difference in thickness between the functional film and the heat generating layer is 310 µm or less. A windshield according to claim 7 or 8, wherein the functional film is an optical film. The windshield according to any one of claims 1 to 9, wherein said heat generating layer is formed of a transparent conductive film. The windshield according to any one of claims 1 to 9, wherein said heat generating layer comprises a base sheet and a plurality of heating wires connecting said bus bars.

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