JP6998661B2 - Rear glass - Google Patents

Description

The present invention relates to a rear glass attached to the rear of a vehicle.

In recent years, a camera for photographing the rear of a vehicle may be provided at the rear of the vehicle, for example, as in Patent Document 1. Such a camera, as a back monitor, turns on when the vehicle moves backward and photographs the rear of the vehicle.

By the way, in recent years, a device called an electronic mirror device has been proposed in place of the rearview mirror. The electronic mirror device uses a camera to photograph the outside of the vehicle through the rear glass of the vehicle, and displays the photographed image on a monitor installed at the position of the rearview mirror. Such a camera is designed to take a picture of the outside of the vehicle through a shooting window formed in the rear glass. The photographing window is formed on a shielding layer such as ceramics coated on the peripheral edge of the rear glass.

Japanese Unexamined Patent Publication No. 2014-372939

By the way, the rear glass as described above is manufactured by applying a shielding layer on a glass plate, heating the glass plate, and then forming the rear glass into a curved surface. At that time, since the shielding layer is formed in a dark color such as black, the amount of heat absorbed by the glass plate is larger than that in the region where the shielding layer is not formed. Here, since the coefficient of thermal expansion of the shielding layer made of ceramic is different from that of glass, the amount of expansion due to heat absorption is different. Therefore, it was found that the glass plate is distorted near the boundary between the shielding layer and the region where the shielding layer is not formed due to the difference in the amount of expansion, and the image seen through the glass plate is distorted. .. Then, it was found that this problem may cause the following problem in the rear glass provided with the above-mentioned camera. That is, if such distortion occurs near the boundary between the shielding layer and the photographing window, the image taken may be distorted due to refraction of light due to the distortion when photographing with a camera.

Such a problem is not limited to the electronic mirror device, but may occur in the entire rear glass for photographing the outside of the vehicle through the photographing window. Therefore, the present invention has been made to solve the above-mentioned problems, and to provide a rear glass capable of taking an accurate picture in a rear glass for taking a picture of the outside of a vehicle through a picture window formed in a shielding layer. The purpose.

The present invention is a rear glass attached to the rear portion of a vehicle, which has a peripheral portion and a central portion surrounded by the peripheral portion, and has a thickness of 2.0 mm or more and at least a peripheral portion of the glass plate. It is provided with a shielding layer that is laminated along a part thereof and blocks the field of view from the outside of the vehicle, and the shielding layer is formed with at least one photographing window capable of photographing the outside of the vehicle by a camera provided inside the vehicle. The size of the photographing window is 2500 mm ² or less.

In the rear glass, the surface compressive stress of the portion of the glass plate corresponding to the photographing window can be 1000 kg / cm ² or more.

In the rear glass, the shielding layer can be laminated on 20% or more of the area of the glass plate.

Each of the rear glasses further includes a pair of bus bars arranged along both sides of the glass plate, and a plurality of heating wires arranged in parallel so as to connect the pair of first bus bars. The heating wire can be arranged at least one first heating wire arranged in the region including the central portion of the glass plate and the region in the shielding layer where the photographing window is formed or around the region. At least one second heating wire can be provided.

In each of the rear glasses, the pair of bus bars can be provided with a first bus bar and a second bus bar arranged with a gap in the vertical direction, respectively, and the pair of the first bus bars sandwich the central portion. The pair of the second bus bars are arranged so as to sandwich the photographing window, and the first heating wire is arranged so as to connect the pair of the first bus bars. The heating wire can be arranged so as to connect the pair of the second bus bars.

In the rear glass, the second heating wire can be arranged so as to pass through the photographing window.

Each of the rear glasses includes a plurality of the photographing windows having at least a first photographing window and a second photographing window, and the first photographing window can be arranged at a position higher than the second photographing window. ..

Each of the rear glasses further includes an antenna device having at least one antenna element, and the antenna element can be provided at an end portion of the peripheral portion of the glass plate opposite to the photographing window.

In each of the rear glasses, the glass plate is installed at an angle within 45 degrees from a vertical straight line extending in the vertical direction, and the photographing window can be formed on the shielding layer laminated on the upper end portion of the glass plate. ..

Each of the rear glasses may be further provided with a mounting member for mounting the camera so as to face the photographing window.

In each of the rear glasses, the photographing window can be arranged in the passage area of the wiper for cleaning the rear glass.

In each of the rear glasses, at least the central portion of the glass plate is coated with a functional film, and the photographing window can be configured so that the functional film is not coated.

In each of the rear glasses, an anti-fog member having an anti-fog layer can be attached to the photographing region corresponding to the photographing window in the glass plate.

In each of the rear glasses, the anti-fog member may further support the anti-fog layer and further include a base film attached to the photographing region.

In each of the rear glasses, the calorific value of the second heating wire can be made different from the calorific value of the first heating wire.

In this case, for example, a plurality of the second heating lines can be provided, and the plurality of the second heating lines can be coupled in the vicinity of the region where the photographing window is formed.

A second aspect of the present invention is a rear glass mounted at the rear of a vehicle, along a glass plate having a peripheral edge and a central portion surrounded by the peripheral edge, and at least a portion of the peripheral edge of the glass plate. It is provided with a shielding layer that is laminated and blocks the view from the outside of the vehicle, and the shielding layer is formed with at least one photographing window capable of photographing the outside of the vehicle by a camera provided inside the vehicle, and the image is taken by the camera. The image is configured to be displayed by an electronic mirror device installed at the mounting position of the rear-view mirror in the vehicle.

According to the present invention, accurate photographing can be performed on the rear glass for photographing the outside of the vehicle through the photographing window formed in the shielding layer.

It is a perspective view of the back door which concerns on this invention. FIG. 3 is a cross-sectional view taken along the line AA of FIG. It is an exploded perspective view of the back door of FIG. It is a front view of the rear glass of the back door of FIG. It is a block diagram which shows the hardware composition of an electronic mirror apparatus. It is a front view and a sectional view of the display part of an electronic mirror device. It is a graph which shows the distortion of a glass plate. It is a front view which shows the other example of a rear glass. It is a front view which shows the other example of a rear glass.

Hereinafter, an embodiment of a back door of a vehicle provided with a rear glass according to the present invention will be described with reference to the drawings. 1 is a front view of the back door according to the present embodiment, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is an exploded perspective view of the back door of FIG. In the following, for convenience of explanation, the vertical direction of FIG. 1 may be referred to as a vertical direction or a vertical direction, and the horizontal direction of FIG. 1 may be referred to as a horizontal direction or a horizontal direction based on the orientation of each figure. be. However, this orientation does not limit the present invention.

<1. Backdoor overview>
As shown in FIG. 1, the back door according to the present embodiment closes, for example, an opening (not shown) at the rear of a hatchback type vehicle, and the roof panel (not shown) of the vehicle constituting the upper edge of this opening. It is attached to (omitted) via a hinge (not shown). That is, it constitutes a flip-up door. Specifically, it is configured as follows. In the following description, when indicating the direction of each part of the back door, the direction with the opening closed shall be indicated unless otherwise specified.

As shown in FIGS. 1 to 3, the back door includes an inner panel 1 arranged inside the vehicle, outer panels 21 and 22 attached to the outside of the inner panel 1, rear glass 3, and an inner panel 1. It has a pair of reinforced frames 4 arranged on the upper part of the frame.

As shown in FIG. 3, the inner panel 1 has a rectangular main body portion 11, a pair of side edge portions 12 attached to the upper end portions of the main body portion 11, and an upper edge connecting the upper ends of both side edge portions 12. A portion 13 is provided, and these are integrally formed. The main body portion 11 is a portion that closes the lower part of the opening, and is formed so as to extend substantially in the vertical direction when the opening is closed. The pair of side edge portions 12 extend diagonally upward from both sides of the upper edge of the main body portion 11. That is, as it goes upward, it extends diagonally toward the front of the vehicle. Then, in order to connect the upper ends of both side edge portions 12 to each other, the upper edge portion 13 has a rectangular window opening 14 formed by the upper edge portion 12, both side edge portions 12, and the upper edge portion 13 of the main body portion 11. The window. Then, the rear glass 3 is attached so as to close the window opening 14.

The outer panel is composed of two members, that is, an upper panel 21 and a lower panel 22. The upper panel 21 is a rectangular member that covers the upper edge portion 13 of the inner panel 1. Further, the lower panel 22 is a member that covers the main body portion 11 of the inner panel 1. Therefore, the rear glass 3 is attached between the upper panel 21 and the lower panel 22.

Since both reinforced frames 4 have a symmetrical shape, only the reinforced frame 4 on the left side will be described here. The reinforced frame 4 has a first portion 41 extending in the vertical direction and a second portion 42 connected to the upper end of the first portion 41 and extending horizontally to the right, and L formed integrally with these. It is a character-shaped member. The reinforced frame 4 is arranged between the inner panel 1 and the outer panels 21 and 22. That is, the first portion 41 of the reinforced frame 4 is attached to the side edge portion 12 of the inner panel 1 and the region corresponding to the vicinity of the upper end of the main body portion 11 following the side edge portion 12. On the other hand, the second portion 42 is attached to a region corresponding to the vicinity of the center from the left end portion of the upper edge portion 13 of the inner panel 1. Therefore, the two reinforcing frames 4 reinforce the vicinity of the upper end of the main body portion 11 of the inner panel 1, the side edge portions 12, and the upper edge portion 13.

The inner panel 1, the upper panel 21, the lower panel 22, and the reinforced frame 4 are made of a resin material. For example, carbon fiber reinforced resin (CFRP) can be adopted. However, since the lower panel 22 does not contribute much to the rigidity of the back door, it can be formed of a resin material such as polypropylene.

Further, a stereo camera 71 used in the electronic mirror device 7 described later is attached to the back door according to the present embodiment. As shown in FIG. 2, the stereo camera 7 is fixed to the inner surface of the rear glass 3 by a bracket 38.

<2. Overview of rear glass>
Next, the rear glass 3 will be described with reference to FIG. FIG. 4 is a front view of the rear glass. As shown in FIG. 4, the rear glass 3 is formed in a rectangular shape, and is formed between the upper panel 21 and the lower panel 22 arranged in the vertical direction by a fastening material (not shown) to the inner panel 1 and the reinforcing frame 4. It is fixed. The rear glass 3 includes a glass plate 31 and a shielding layer 32 laminated on the peripheral edge of the glass plate 31 to block the field of view from the outside of the vehicle. Further, the defogger 5 and the antenna element 6 are mounted on the glass plate 31. Hereinafter, each member will be described in order.

<2-1. Glass plate>
As the glass plate 31, a known glass plate for automobiles can be used. For example, as the glass plate 31, heat ray absorbing glass, general clear glass or green glass, or UV green glass may be used. However, such glass plates need to achieve visible light transmittance in line with the safety standards of the country in which the vehicle is used. For example, the solar radiation absorption rate, the visible light transmittance, and the like can be adjusted so as to satisfy the safety standards. An example of the composition of the clear glass and an example of the composition of the heat ray absorbing glass are shown below.

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

(Heat ray absorbing glass)
For the composition of the heat ray absorbing glass, for example, the ratio of total iron oxide (T-Fe ₂ O ₃ ) converted to Fe ₂ O ₃ is set to 0.4 to 1.3% by mass based on the composition of clear glass, and CeO. The ratio of ₂ is 0 to 2% by mass, the ratio of TiO ₂ is 0 to 0.5% by mass, and the skeleton components of glass (mainly SiO ₂ and Al ₂ O ₃ ) are T-Fe ₂ O ₃ and CeO. The composition can be reduced by the amount of increase in ₂ and TiO ₂ .

The type of the glass plate 31 is not limited to clear glass or heat ray absorbing glass, and can be appropriately selected according to the embodiment. For example, the glass plate may be an acrylic-based or polycarbonate-based resin window.

The thickness of the glass plate 31 can be, for example, 2.0 mm or more, preferably 2.5 mm or more, more preferably 2.8 mm or more, and particularly preferably 3.0 mm or more. ..

Further, the glass plate 31 is appropriately formed into a curved shape so as to follow the shape of the inner panel 1. In addition to being composed of a single glass plate, such a glass plate 31 may be a laminated glass in which an interlayer film such as a resin is sandwiched between a plurality of glasses.

Further, as shown in FIG. 2, the glass plate 31 is supported by the back door at an inclination angle α within 45 degrees from the vertical straight line N extending in the vertical direction.

The glass plate 31 as described above can be manufactured by various methods, and for example, it can be manufactured by the following method. First, when the glass plate is sent to the heating furnace, it is heated to about 620 ° C. near the softening point. Then, the glass plate is carried out from the heating furnace at about 620 ° C., and is rapidly cooled to about 450 ° C. in the air-cooled strengthening section. Due to this quenching, compressive stress is generated on the surface layer of the glass plate, and the glass plate becomes a tempered glass plate. Next, the air-cooled glass plate is slowly cooled and cooled to room temperature. Subsequently, the tempered glass plate in a normal temperature state is carried into the soak furnace, and the temperature is raised to the above-mentioned predetermined temperature range at a specific temperature rising rate. At this time, if α-NiS (α phase) is contained in the tempered glass plate, this NiS undergoes a phase transition from the α phase to the stable β phase via the unstable β phase. Due to the phase transition from the α phase to the β phase, the volume of nickel sulphate (NiS) increases, causing cracks from the interface between the nickel sulphate (NiS) particles and the glass in the direction orthogonal to the circumference of the glass. As a result, the glass plate of the defective product containing nickel (NiS) sulfide can be completely eliminated because it leads to sudden natural damage.

The compressive stress generated on the surface layer of the glass plate 31 (hereinafter referred to as surface compressive stress) can be measured according to Japanese Industrial Standards (JIS) R3222. In the photographing window described later, for example, a plurality of measurements around the center of the photographing window can be measured, and the average value thereof can be used as the surface compressive stress. The rear glass according to the present embodiment preferably has a weight of 1000 kg / cm ² or more, preferably 1500 kg / cm ² or more, and preferably 2000 kg / cm ² or more.

<2-2. Shielding layer>
As shown in FIG. 4, the shielding layer 32 is laminated on the peripheral edge of the inner surface of the glass plate 31. That is, it is formed in a frame shape by the upper end portion 321 and the lower end portion 322, and the pair of side end portions 323. Since the shielding layer 32 is formed by laminating a dark-colored ceramic layer as described later, the field of view from the outside of the vehicle is blocked. That is, the inside of the vehicle cannot be seen through the peripheral edge of the glass plate 31. In the present embodiment, the above-mentioned inner panel 1 and the reinforcing frame 4 are arranged at positions corresponding to the shielding layer 32 so that they cannot be seen from the outside of the vehicle through the glass plate 31. Further, in the glass plate 31, the rectangular central portion 34 surrounded by the shielding layer 32 allows light to pass through and secures a field of view from the inside of the vehicle or from the outside of the vehicle.

Further, two rectangular photographing windows, that is, a first photographing window 331 and a second photographing window 332 are formed near the center of the lower end portion 322 of the shielding layer 32. These shooting windows 331 and 332 are openings formed in the shielding layer 32, and a pair of cameras constituting the stereo camera 71 are located at positions corresponding to the shooting windows 331 and 332 in the vehicle, respectively, as will be described later. Each camera is arranged so that the outside of the vehicle can be photographed through these photographing windows 331 and 332. Further, in the present embodiment, the first photographing window 331 is arranged on the upper side, and the second photographing window 332 is arranged on the lower right of the first photographing window 331. The area of each photographing window 331, 332 is 2500 mm ² or less, preferably 2000 mm ² or less, and more preferably 1500 mm ² or less.

＊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 The ceramic layer constituting the shielding layer 32 can be formed of various materials, and can have, for example, the following composition.

* 1, Main component: Copper oxide, Chromium oxide, Iron oxide and Manganese oxide * 2, Main component: Bismuth borosilicate, Zinc borosilicate

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

The shielding layer 32 is preferably formed in 20% or more of the area of the glass plate 31, more preferably 30% or more, and particularly preferably 40% or more.

As described above, Aglas can be manufactured as follows. For example, first, the shielding layer 32 is formed on the glass plate 31. The glass plate 31 is heated to about 650 degrees by passing it through a heating furnace, and then molded into a curved surface using a molding die. The curved surface shape in this case may have a curvature in only one direction, or may have a curvature in a plurality of directions. After that, slow cooling is performed outside the heating furnace. Molding with a molding die can be performed by, for example, a press, or a curved surface is formed by heating with the peripheral edge of the glass plate placed in the molding die and bending the vicinity of the center of the glass plate downward due to its own weight. Can also be done.

<2-3. Defogger>
Next, the defogger 5 will be described. As shown in FIG. 4, the defogger 5 includes a pair of bus bars 51a and 51b for feeding, which extend in the vertical direction along both side edges of the glass plate 31. Further, a plurality of heating lines 52 extending in the horizontal direction are arranged in parallel at predetermined intervals so as to connect the two bus bars 51a and 51b, and these heating lines 52 are supplied with power from the bus bars 51a and 51b. Anti-fog heat is generated.

The bus bars 51a and 51b and the heating wire 52 are arranged on the inner surface of the glass plate 31. More specifically, both bus bars 51a and 51b are arranged on the side end portion 323 of the shielding layer 32, sandwich the central portion 34 of the glass plate 31, and further extend to the lower end portion 322 of the shielding layer 32. .. As a result, the bus bars 51a and 51b are invisible from the outside of the vehicle. Further, the plurality of heating wires 52 are composed of a first heating wire 521 passing through the central portion 34 of the glass plate 31 and a second heating wire 522 passing through the lower end portion 322 of the shielding layer 32. Of these, the second heating wire 522 is arranged so as to pass through the photographing windows 331 and 332.

<2-4. Brackets and cameras>
As described above, the camera 71 is fixed to the inner surface of the rear glass 3 via the bracket 38. The shape of the bracket 38 is not particularly limited, but it may be any shape that can support the camera 71. In the present embodiment, two cameras are used as the stereo camera 71, and they are arranged at positions corresponding to the above-mentioned first shooting window 331 and the second shooting window 332. Then, in order to fix the position of each camera, it is supported by the bracket 38. The bracket 38 is fixed to the glass plate with double-sided tape or an adhesive.

<2-5. Antenna device>
Next, the antenna device will be described. The antenna device according to the present embodiment is an antenna for a digital television, and includes an antenna element 6 arranged on a glass plate 31. As shown in FIG. 4, the antenna element 6 is arranged near the center of the upper end portion 321 of the shielding layer 32, and is composed of an antenna main body element 61 and a ground connection element 62. The antenna main body element 61 has a rectangular feeding portion 611 and a horizontal portion 612 extending to the right from the feeding portion 611. On the other hand, the ground connection element 62 includes a rectangular ground connection portion 621 arranged on the left side of the power feeding portion 611, and a ground main body 622 connected to the ground connection portion 621. The ground body 622 extends from the upper end of the ground connection portion 621 to the left side, the vertical portion extending downward from the left end of the upper horizontal portion, and the lower end of the vertical portion to the right side, and extends to the lower end of the ground connection portion 621. It is composed of a second horizontal portion to be connected.

In addition, the automobile is provided with a receiver for a digital television (not shown) and an amplifier connected to the receiver (not shown), and power is supplied to the internal conductor of the coaxial cable (not shown) connected to the amplifier. The unit 611 is connected. On the other hand, the ground connection portion 621 is electrically connected to the outer conductor of the coaxial cable and is grounded.

<2-6. Material>
The defogger 5 and the antenna element 6 as described above are configured by combining wire rods, and these are made by laminating a conductive material having conductivity on the surface of a glass plate 31 so as to have a predetermined pattern. Can be formed with. As such a material, it suffices to have conductivity and can be appropriately selected depending on the embodiment, and examples thereof include silver, gold, and platinum. Specifically, for example, it can be formed by printing a conductive silver paste containing silver powder, glass frit, etc. on the surface of the rear glass 3 and firing it.

<3. Electronic mirror device>
Next, the electronic mirror device 7 will be described with reference to FIGS. 5 and 6. First, the hardware configuration of the electronic mirror device 7 will be described. As shown in FIG. 5, the electronic mirror device 7 includes a stereo camera 71, a control unit 72, an operation unit 73, a display unit 74, and a storage unit 75. The control unit 72 controls to process the captured image captured by the stereo camera 71 and display it on the display unit 74. It also controls the overall information of the electronic mirror device 7. More specifically, the control unit 72 includes one or a plurality of processors such as a microprocessor or a CPU (Central Processing Unit), and peripheral circuits (ROM (Read Only Memory), RAM (Random)) used for processing of this processor. Access Memory), interface circuit, etc.). The ROM, RAM, and the like may be referred to as a main storage device in the sense that they are arranged in the address space handled by the processor in the control unit 72. Then, the control unit 72 executes various data and programs stored in the storage unit 75, which will be described later, to perform various types of electronic mirror devices 7 such as control of the operation unit 73 as well as the image processing described above. Do the action.

The storage unit 75 stores various data and programs used in the processing executed by the control unit 72. The storage unit 75 may be realized by, for example, a hard disk or a recording medium such as a USB memory. Further, the various data and programs stored in the storage unit 75 may be acquired from a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). Further, the storage unit 75 may be referred to as an auxiliary storage device.

Next, the display unit 74 will be described. As shown in FIG. 6, the display unit 74 is fixed to the inner surface of the windshield (not shown) as a so-called rearview mirror, and has a horizontally long rectangular housing 741 and the housing 741. A support portion 742 for fixing the housing 741 to the inner surface of the windshield is provided. An internal space is formed in the housing 741, and this internal space is open to the outside through an opening facing the inside of the vehicle. A half mirror 743 and a liquid crystal display 744 are attached to the internal space in this order from the inside of the vehicle. That is, a half mirror 743 is fitted in the opening of the housing 741, and a liquid crystal display 744 is attached behind the half mirror 743. Then, the liquid crystal display 744 displays the captured image captured by the stereo camera 71.

The operation unit 73 turns on / off the display of the captured image on the liquid crystal display 744. For example, when the liquid crystal display 744 is turned on by the operation unit 73, the captured image is displayed on the liquid crystal display 744. As a result, the captured image displayed on the liquid crystal display 744 can be viewed from inside the vehicle via the half mirror 743. On the other hand, when the liquid crystal display 744 is turned off by the operation unit 73, the back of the half mirror 743 becomes dark inside the housing 741, so that the light from the inside of the vehicle is reflected on the half mirror 743 and functions as a mirror. ..

<4. Features>
As described above, according to the present embodiment, the following effects can be obtained.

(1) In the present embodiment, the photographing windows 331 and 332 are formed on the shielding layer 32, and the outside of the vehicle is photographed from the photographing windows 331 and 332 by the stereo camera 71 for the electronic mirror device 7. .. For example, if the stereo camera 71 is arranged in the central portion 34 of the glass plate 31, the field of view from the inside of the vehicle is obstructed. However, by providing the photographing windows 331 and 332 in the shielding layer 32, the stereo camera 71 is provided in the central portion 34. Since it is not arranged, it is possible to prevent the rear glass 3 from being reduced in the field of view from the inside of the vehicle. In particular, in the rear glass 3, as described above, since the inner panel 1 and the reinforcing frame 4 are hidden, the area of the shielding layer 32 is larger than that of the windshield, so that the areas forming the photographing windows 331 and 332 can be easily formed. Can be secured.

(2) The photographing windows 331 and 332 formed as described above are formed in the shielding layer 32, but as pointed out in the above-mentioned problems, there are the following problems. That is, since the coefficient of thermal expansion of the shielding layer 32 made of ceramic is different from that of glass, the amount of expansion due to heat absorption is different. Therefore, the glass plate is distorted in the vicinity of the boundary between the shielding layer 32 and the region where the shielding layer 32 is not formed during molding due to the difference in the amount of expansion. This point was examined as follows.

That is, when the strain of the glass plate near the boundary of the shielding layer was measured, it was as shown in FIG. In this graph, the horizontal axis is the length of the glass plate in the plane direction, and the vertical axis is the lens power (mili diopter: reciprocal of the focal length). The method for measuring the lens power is as follows. First, light is projected onto the glass plate in a dark room to form a shadow on the screen behind the glass plate. At this time, if there is a convex lens on the glass plate, the light is condensed and the shadow on the screen becomes bright. On the other hand, if there is a concave lens on the glass plate, it will be dark. Here, there is a correlation between the lens power and the brightness of the shadow on the screen, and by placing a lens with a known lens power and measuring the brightness on the screen at that time, the relationship between the lens power and the brightness Can be obtained. Therefore, the lens power of the glass plate can be obtained by arranging the target glass plate and measuring the brightness on the screen over the entire surface of the glass.

As a result of such measurement, according to FIG. 7, it can be seen that the distortion increases because the lens power increases sharply in the vicinity of the boundary from the shielding layer toward the photographing window. It can be seen that the strain is reduced when the distance from the boundary is a predetermined length, and disappears when the distance is further increased.

Therefore, it has been found that when shooting with a camera, the shot image may be distorted due to refraction of light due to distortion near the boundary between the shielding layer and the shooting window. It should be noted that such a problem may occur even when the front of the vehicle is photographed in the windshield. That is, a shielding layer is also provided on the windshield, and the above-mentioned problems may occur when photographing the outside of the vehicle from the photographing window formed in the shielding layer.

On the other hand, it is conceivable to enlarge the shooting window so that the vicinity of the periphery of the shooting window is not covered by the shooting range. However, since the rear glass according to the present embodiment has a thickness of 2.0 mm or more, it has been found by the present inventor that the strain as described above is small. Therefore, according to the present embodiment, even if the size of each shooting window 331, 332 is not increased, that is, even if the size is 2500 mm ² or less, the distortion is small and the influence of the distortion on the shot image is reduced. can do. This point is different from the windshield made of laminated glass. That is, since the laminated glass constituting the windshield is generally made by laminating glass plates of less than 2 mm, distortion is likely to occur in either or both of the glass plates on which the shielding layer is formed. Therefore, it will be considered that the photographing window formed on the windshield is formed large in consideration of the influence of the above distortion.

Further, in the rear glass of the present embodiment, the photographing window can be made smaller than that of the windshield from the following points. First, the windshield is a laminated glass in which an inner glass plate and an outer glass plate are bonded together, and the shielding layer is laminated on the inner surface of the inner glass plate (hereinafter referred to as the innermost surface). Then, as described above, when distortion occurs in the vicinity of the boundary between the shielding layer and the region where the shielding layer is not formed during molding, the innermost surface becomes convex. On the other hand, since the shielding layer is not laminated on the outer glass plate, stress does not act. Therefore, the outer surface of the outer glass plate (hereinafter referred to as the outermost surface) does not have a convex shape. As a result, when the shielding layer is laminated on the innermost surface of the windshield, the outermost surface and the innermost surface become non-parallel, and the distortion becomes remarkable.

On the other hand, since the rear glass is a single plate, even if stress is applied by laminating the shielding layer, the inner surface of the vehicle and the outer surface of the vehicle are kept substantially parallel, so that the occurrence of distortion is suppressed. Therefore, from this viewpoint as well, it is possible to reduce the influence of distortion on the photographed image without increasing the size of the photographing windows 331 and 332.

It has also been found by the present inventor that the reduction of strain can also be achieved by increasing the surface compressive stress. That is, it has been found by the present inventor that the strain is reduced when the rear glass is made of tempered glass and the surface compressive stress in the region corresponding to the photographing windows 331 and 332 is 1000 kg / cm ² or more.

(3) Since the second heating line 522 of the defogger 5 passes through the photographing windows 331 and 332, it is possible to prevent the photographing windows 331 and 332 from becoming cloudy. That is, the photographing windows 331 and 332 can be prevented from fogging by utilizing the defogger that heats the central portion. The second heating line 522 does not have to pass through the photographing windows 331 and 332, and may pass around the photographing windows 331 and 332.

(4) In the present embodiment, since the two shooting windows 331 and 332 are provided, for example, even if one shooting window 331 is blocked by dirt or the like, the image taken from the other shooting window 332 is provided. Can be displayed on the liquid crystal display 744 by performing image processing. Further, in the present embodiment, since the heights of the two shooting windows 331 and 332 are changed, it becomes easy to form a three-dimensional image by image processing.

(5) In the present embodiment, the antenna element 6 is arranged at the upper end portion 321 of the shielding layer 32, and the photographing windows 331 and 332 are arranged at the lower end portion 322 of the shielding layer 32. That is, since the distance between the antenna element 6 and the stereo camera 71 is increased, the noise from the stereo camera 71 can be reduced in the antenna element 6. In particular, by arranging the antenna element 6 on the upper part of the rear glass 3, the reception performance can be improved.

(6) Since the inclination angle of the glass plate 31 is within 45 degrees, the following effects can be obtained. In the production of the glass plate, the glass plate is conveyed by a roller in a heating furnace. At this time, since the glass bends between the adjacent rollers, the glass plate may be distorted to extend in parallel. Therefore, when the tilt angle of the glass plate 31 is large, the apparent distortion interval becomes small, and the distortion may be conspicuous. On the other hand, if the inclination angle of the glass plate 31 is made small so as to be within 45 degrees, the apparent distortion interval becomes large, so that the distortion can be prevented from being conspicuous. Further, when the inclination angle of the glass plate 31 is reduced, the thickness of the glass plate 31 in the horizontal direction is reduced, so that the influence of the distortion of the light passing through the glass plate 31 can be reduced.

<5. Modification example>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. The following modifications can be combined as appropriate.

<5-1>
The shooting window can be arranged in the passage area of the wiper. This makes it possible to remove dirt from the shooting window. The wiper can have various configurations, and for example, a through hole may be formed in the glass plate 31 and the rotation axis of the wiper may be arranged therein. Alternatively, the rotation axis of the wiper may be arranged on the outer panel.

<5-2>
The glass plate 31 can be coated with various functional films. For example, it is possible to coat a functional film for UV cut, infrared cut, water repellency and the like. It is preferable that such a functional film is coated only on the central portion 34 of the glass plate 31 and not on the photographing windows 331 and 332. This is because if the photographing windows 331 and 332 are coated with the functional film, the transmittance of visible light may be reduced, which may interfere with the photographing by the camera.

<5-3>
In the above embodiment, the photographing windows 331 and 332 are formed on the lower end portion 322 of the shielding layer 32, but they can also be formed on the upper end portion 321 or the side end portion 323 of the shielding layer 32. In particular, if it is formed at the upper end portion 321 because it is arranged at a position close to the hinge of the back door, wiring into the vehicle becomes easy. When the photographing windows 331 and 332 are arranged at the upper end portion 321 of the shielding layer 32, it is preferable that the antenna element 6 is arranged at the lower end portion 322 of the shielding layer 32 on the opposite side. However, the positions of the photographing windows 331 and 332 and the antenna element 6 are not particularly limited.

<5-4>
In the above embodiment, two photographing windows 331 and 332 are provided, but one may be used. In this case, a normal camera is arranged instead of a stereo camera. Further, the shape and position of the photographing windows 331 and 332 are not particularly limited. For example, as shown in FIG. 8, an extending portion 324 extending downward can be provided in the center of the upper end portion 321 of the shielding layer 32, and a photographing window 339 can be formed in the extending portion 324. Then, a heating wire is arranged around the photographing window 339 as follows. That is, two heating lines 521a and 521b are extended from the upper portions of both bus bars 55a and 55b toward the extending portion 324, respectively, and the heating lines 521a and 521b come closer to each other as they approach the photographing window 339. Deploy. Then, these heating lines 521a and 521b are configured to merge on the side of the photographing window 339, and the merged heating lines 521c are arranged so as to surround the photographing window 339 along the side and the upper side of the photographing window 339. do. By doing so, it is possible to surely prevent fogging of the photographing window 339.

In this way, by arranging a plurality of heating lines 521a and 521b around the photographing window 339 to eliminate fogging at an early stage and combining them, the calorific value can be increased. In addition, in order to increase the calorific value, it is conceivable to reduce the line width of the heating wire, but if this is done, there is a risk of disconnection. Further, when forming a heating line by screen printing or the like, if the line width is small, it may not be formed properly. Therefore, as described above, when a plurality of heating lines are combined, the calorific value can be increased without reducing the line width. For example, assuming that the calorific value per heating wire is about 400 kW, in the case of the configuration as shown in FIG. 8, since the two heating wires 521a and 521b are connected around the photographing window 339, The calorific value can be about 800 kW. On the other hand, since the heating wires arranged in the other regions of the rear glass generate heat of about 400 kW, the heat generated by the heating wires 521a and 521b around the photographing window 339 is about twice that of the other regions. can do. In this way, the calorific value of the region including the vicinity of the photographing window 339 and the central portion of the other rear glass can be appropriately different. The heating wires 521a and 521b arranged around the photographing window 339 correspond to the second heating wire of the present invention, and the other heating wires correspond to the first heating wire of the present invention.

Further, in the above embodiment, the photographing windows 331 and 332 have a closed shape surrounded by the periphery, but a part thereof is U-shaped so as to open to the end side or the center portion 34 side of the glass plate 31. It may have a shape such as a mold.

<5-5>
In the above embodiment, the shielding layer 32 is arranged on the entire peripheral edge portion of the glass plate 31, but may be a part thereof. Further, the shape is not particularly limited, and for example, a convex portion protruding toward the central portion 34 may be formed, if necessary.

<5-6>
In the above embodiment, a digital TV antenna is used as the antenna device, but various antennas such as an FM antenna, an AM antenna, and a DAB antenna can be used, and at least one of these can be arranged on the glass plate 31. can. Therefore, the position and shape of the antenna element are not particularly limited. The antenna device can also be placed inside the back door. For example, it may be arranged between the inner panel 1 and the upper panel 21, or between the inner panel 1 and the lower panel 22.

<5-7>
The shape of the defogger 5 is not particularly limited, and can be, for example, as shown in FIG. As shown in FIG. 9, in this example, the Defogger bus bar is divided into two. That is, it includes a pair of first bus bars 55a arranged so as to sandwich the central portion 34 of the glass plate 31, and second bus bars 56a arranged on both sides of the lower end portion 322 of the shielding layer 32. The first heating wire 521 is arranged so as to connect the first bus bar 55a, and the second heating wire 522 is arranged so as to connect the second bus bar 56a. Further, the second heating wire 522 is arranged so as to pass through the two photographing windows 331 and 332 as in the above embodiment. However, it may pass around the photographing windows 331 and 332.

By dividing the bus bar into two in this way, it is possible to apply currents suitable for anti-fog of the central portion 34 and the photographing windows 331 and 332, respectively. That is, since the areas of the central portion 34 and the photographing windows 331 and 332 are different, the number of heating lines is also different. Therefore, rather than using the same bus bar, it is possible to design so that a current suitable for each can be applied.

<5-8>
It is also possible to prevent fogging by arranging an anti-fog member on the inner surface of the glass plate 31 corresponding to the shooting windows 331 and 332. The anti-fog member can have various configurations. For example, as the anti-fog member, a liquid material can be applied to form a cured anti-fog layer, which can be used as the anti-fog member. As the antifogging layer, a known one can be used, but in general, a hydrophilic type that forms water generated from water vapor as a water film on the surface, a water absorption type that absorbs water vapor, and a repellency that makes it difficult for water droplets to condense on the surface. There are a water-absorbing type and a water-repellent type that repels water droplets generated from water vapor, and any type of antifogging layer can be applied.

Further, such an anti-fog layer can be formed on the base film, and the base film can be attached to the glass plate 31 by the adhesive layer. That is, the base film on which the anti-fog layer is formed can also be used as the anti-fog member. The base film is formed of, for example, a transparent resin film, and can be formed of, for example, polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride, or an acrylic resin.

<5-9>
In the above embodiment, an example in which the rear glass of the present invention is provided on the back door has been described, but the rear glass of a sedan type vehicle can also be used, and the vehicle type is not particularly limited.

3: Rear glass 31: Glass plate 32: Shielding layer 331, 332: Shooting window 5: Defogger 6: Antenna element

Claims (15)

The rear glass that is attached to the rear of the vehicle
A glass plate which is a veneer having a peripheral portion and a central portion surrounded by the peripheral portion, having a thickness of 2.0 mm or more, and having a surface on the outside of the vehicle and a surface on the inside of the vehicle.
A shielding layer that is laminated along at least a part of the peripheral edge of the glass plate and blocks the field of view from the outside of the vehicle.
A pair of bus bars arranged along both sides of the glass plate, and
A plurality of heating wires arranged in parallel so as to connect the pair of first bus bars,
Equipped with
The shielding layer is formed with at least one photographing window capable of photographing the outside of the vehicle by a camera provided inside the vehicle.
The inner surface of the vehicle and the outer surface of the vehicle are substantially parallel to each other.
The size of the shooting window is 2500 mm ² or less .
The plurality of heating lines are
With at least one first heating wire arranged in the region including the central portion of the glass plate,
In the shielding layer, at least one second heating line arranged in or around the area where the photographing window is formed, and
The rear glass is equipped with . The rear glass according to claim 1, wherein the surface compressive stress of the portion of the glass plate corresponding to the photographing window is 1000 kg / cm ² or more. The rear glass according to claim 1, wherein the shielding layer is laminated on 20% or more of the area of the glass plate. The pair of bus bars each include a first bus bar and a second bus bar arranged with a gap in the vertical direction.
The pair of the first bus bars are arranged so as to sandwich the central portion thereof.
The pair of the second bus bars are arranged so as to sandwich the shooting window.
The first heating wire is arranged so as to connect the pair of the first bus bars.
The rear glass according to any one of claims 1 to 3, wherein the second heating wire is arranged so as to connect the pair of the second bus bars. The rear glass according to any one of claims 1 to 4, wherein the second heating line is arranged so as to pass through the photographing window. The plurality of shooting windows having at least a first shooting window and a second shooting window are provided.
The rear glass according to any one of claims 1 to 5 , wherein the first photographing window is arranged at a position higher than that of the second photographing window. Further equipped with an antenna device having at least one antenna element,
The rear glass according to any one of claims 1 to 6 , wherein the antenna element is provided at an end portion of the peripheral portion of the glass plate opposite to the photographing window. The glass plate is installed at an angle within 45 degrees from a vertical straight line extending in the vertical direction.
The rear glass according to any one of claims 1 to 7 , wherein the photographing window is formed on the shielding layer laminated on the upper end portion of the glass plate. The rear glass according to any one of claims 1 to 8 , further comprising a mounting member for mounting the camera so as to face the photographing window. The rear glass according to any one of claims 1 to 9 , wherein the photographing window is arranged in a passage region of a wiper for cleaning the rear glass. At least the central part of the glass plate is coated with a functional film.
The rear glass according to any one of claims 1 to 10 , wherein the photographing window is not coated with the functional film. The rear glass according to any one of claims 1 to 11 , wherein an anti-fog member having an anti-fog layer is attached to the photographing region corresponding to the photographing window in the glass plate. The rear glass according to claim 12 , wherein the anti-fog member supports the anti-fog layer and further includes a base film attached to the photographing region. The rear glass according to any one of claims 1 to 5 , wherein the calorific value of the second heating wire is different from the calorific value of the first heating wire. Equipped with a plurality of the second heating wires,
The rear glass according to claim 14 , wherein a plurality of the second heating lines are bonded in the vicinity of the region where the photographing window is formed.

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