JPWO2016208370A1 - Windshield - Google Patents

Abstract

The present invention relates to a windshield used in a vehicle in which an information device that acquires information or provides information by light irradiation and / or incidence can be arranged, and includes a window glass having at least one glass plate. The window glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between the two glass plates, the window glass from light incident on the information device, or the information device An absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when the light passes through each glass plate is provided. On the other hand, the absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when light passes through the passage region is 10 mdpt or less.

Description

  The present invention relates to a windshield.

  In recent years, various systems for supporting driving and enhancing safety, for example, information devices having optical systems such as a front monitoring camera, laser radar, and HUD (head-up display) are arranged inside the windshield. A proposed system has been proposed. These devices irradiate light or receive and receive information by receiving light. A windshield through which such light passes or reflects also functions as one of the optical elements. Therefore, the optical characteristics of the windshield are also required to have high accuracy corresponding to these devices, and various windshields have been proposed (for example, Patent Document 1).

JP 2007-290549 A

  By the way, the window glass which comprises a windshield is the laminated glass manufactured by the float glass process. More specifically, a resin intermediate film is disposed between the outer glass plate and the inner glass plate manufactured by the float process. However, since irregular irregularities are formed on the surface of the window glass manufactured by the float process, the inventor says that such irregularities adversely affect image formation in the optical system in the information device. I found a problem. Hereinafter, this point will be described in detail.

  First, as shown in FIG. 35, the irregular glass irregularities are formed in a predetermined direction on the single glass plate 10 manufactured by the float process. However, since the amount of change in the thickness of the glass plate 10 is smaller than the amount of unevenness on the front surface, the unevenness formed on the front surface corresponds to the shape of the unevenness formed on the back surface. Therefore, the inclination of the front surface and the inclination of the back surface corresponding to this are substantially the same. Therefore, for example, as shown in FIG. 35, the light incident from the surface having irregular irregularities is refracted on the surface, but is refracted and emitted at the reverse angle on the back surface. Is almost parallel. Therefore, it was found that a single glass plate manufactured by the float process has small defects on the wavefront that is transmitted even if irregular irregularities occur on the front and back surfaces (hereinafter referred to as “cancellation by both sides of the single plate”). Function ”or“ cancellation effect ”). As a result, it was found that irregular irregularities of the transmitted wavefront were reduced, and thereby the lens action was suppressed.

  In contrast, a laminated glass as shown in FIG. 36 includes an outer glass plate 11 and an inner glass plate 12, and an intermediate film 13 is disposed between them. Here, the outer glass plate 11 and the intermediate film 13 and the inner glass plate 12 and the intermediate film 13 are in close contact with each other, and there is almost no difference in refractive index. . In addition, the outer glass plate alone or the inner glass plate alone has irregular irregularities between the front surface and the back surface as described above, so that distortion of the image is suppressed, but the outer glass plate 11 and the inner glass plate are suppressed. Since the plate 12 is a different glass plate, the unevenness does not necessarily match, but rather the position of the unevenness is naturally shifted. Therefore, as shown in FIG. 36, the unevenness of the vehicle outer surface of the outer glass plate 11 and the unevenness of the vehicle inner surface of the inner glass plate 12 are separated from each other. The light incident from the side is refracted and travels straight inside the outer glass plate 11, the intermediate film 13, and the inner glass plate 12, and is further refracted on the inner surface of the inner glass plate 12. Therefore, the incident light and the outgoing light are not parallel to each other and are at different angles. That is, it was found that the wavefront defect of the light that passed through the laminated glass 10 was large. As a result, irregular irregularities of the transmitted wavefront increase, and as a result, the lens action increases, and the image generated by the light incident on the camera (information device) through the laminated glass 10 may be distorted. It was found.

  Thus, it has been found that when conventional laminated glass is used, a problem may occur in information processing due to an adverse effect on image formation. The present invention has been made to solve this problem, and provides a windshield that can accurately irradiate and / or receive light by an information device and accurately process information. The purpose is to do.

Item 1: A windshield used in a vehicle capable of arranging an information device that acquires information or provides information by light irradiation and / or incidence,
Comprising a window glass having at least one glass plate;
The window glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between the two glass plates,
The window glass includes a light incident area to the information device or a light passing region irradiated from the information device,
When the absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when the light is transmitted through the window glass is 10 mdpt or more, the light is transmitted through the passage region. A windshield in which the absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated in the lens is 10 mdpt or less.

Item 2: The windshield according to claim 1, wherein the outer glass surface of the outer glass and the inner glass surface of the inner glass plate are substantially parallel to each other.

Item 3: A windshield used in a vehicle capable of arranging an information device that acquires information or provides information by light irradiation and / or incidence,
With window glass,
The window glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between the two glass plates,
The absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when light passes through each glass plate is 10 mdpt or more,
The window glass includes a light incident area to the information device or a light passing region irradiated from the information device,
A windshield in which a through hole is formed in at least the intermediate film among the intermediate film and the inner glass plate at a position corresponding to the passage region of the window glass.

Item 4: The windshield according to item 3, wherein a through-hole is formed in both the intermediate film and the inner glass plate at a position corresponding to the passage region of the window glass.

Item 5: The windshield according to Item 5, wherein an antireflection film is provided on at least a part of at least one of the vehicle outer surface and the vehicle inner surface in the passage region of the inner glass plate.

Item 6: In the passage region of the outer glass plate and / or the inner glass plate, at least a part of at least one of the vehicle outer surface and the vehicle inner surface is provided with an antifogging means. The described windshield.

  According to the present invention, light irradiation and / or light reception by an information device can be performed with high accuracy, and information processing can be performed accurately.

It is a top view which shows one Embodiment of the windshield which concerns on this invention. It is sectional drawing of FIG. It is sectional drawing of a laminated glass. It is a schematic plan view which shows the measurement position of the thickness of a laminated glass. It is an example of the image used for the measurement of an intermediate film. It is a block diagram of the vehicle-mounted system arrange | positioned at the windshield of FIG. It is the schematic which shows an example of the manufacturing process of the windshield of FIG. It is sectional drawing which shows passage of the light ray in a parallel plate glass. It is sectional drawing which shows passage of the wave of light in a parallel plate glass. It is a schematic diagram explaining that the wavefront aberration generated when light is transmitted through the surface of the windshield is a composite of a spherical component, an ass component, and an irregular component. It is sectional drawing of the windshield which concerns on 1st Embodiment. It is sectional drawing which shows the other example of the windshield which concerns on 1st Embodiment. FIG. 13 is a model diagram (a) for examining distortion in the windshield of FIG. 12 and a diagram (b) showing evaluation points on the target. It is a graph which shows the relationship between the taper angle calculated by the model of Fig.13 (a), and the amount of distortion. It is sectional drawing which shows the windshield which concerns on 2nd Embodiment. It is sectional drawing which shows the other example of the windshield which concerns on 2nd Embodiment. It is the figure which expressed the surface of the glass plate concerning Example 1 three-dimensionally. It is the figure which expressed the state which left the irregular component in the surface of the glass plate which concerns on Example 1 in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is the figure which expressed the transmitted wave front of the glass plate concerning Example 1 three-dimensionally. It is the figure which represented the state which left the irregular component in the transmitted wave front of the glass plate which concerns on Example 1 in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is the figure which expressed the transmitted wave front of the glass plate which concerns on a comparative example three-dimensionally. It is the figure which represented the state which left the irregular component in the transmitted wave front of the glass plate which concerns on a comparative example, in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is the figure which expressed A surface of the glass plate concerning Example 2 three-dimensionally. It is the figure which expressed the state which left the irregular component in the A surface of the glass plate which concerns on Example 2 in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is the figure which expressed the transmitted wave front of the glass plate which concerns on Example 2 three-dimensionally. It is the figure which expressed the state which left the irregular component in the transmitted wave front of the glass plate which concerns on Example 2 in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is the figure which expressed the transmitted wave front of the glass plate which concerns on Example 3 three-dimensionally. It is the figure which represented the state which left the irregular component in the transmitted wave front of the glass plate which concerns on Example 3 in three dimensions. It is a figure which shows the height difference of the wave front along the white line of FIG. It is a figure explaining the light which passes the glass plate of the single plate manufactured by the float glass process. It is a figure explaining the light which passes the laminated glass manufactured by the float glass process.

  Hereinafter, first and second embodiments of a windshield according to the present invention will be described with reference to the drawings. The windshield according to each embodiment is provided with a generally common glass plate, and a photographing device is disposed on the inner side of the vehicle. In the following, first, an in-vehicle system including a glass plate, a shielding layer, and an imaging device, and a method for manufacturing a windshield, which are generally common to the respective embodiments, will be described, and then a unique configuration of each embodiment will be described.

<1. Common configuration>
<1-1. Schematic configuration>
First, the structure of the windshield which concerns on each embodiment is demonstrated using FIG.1 and FIG.2. FIG. 1 is a plan view of the windshield, and FIG. 2 is a cross-sectional view of FIG. For convenience of explanation, the vertical direction in FIG. 1 is referred to as “up and down”, “vertical”, and “vertical”, and the horizontal direction in FIG. 1 is referred to as “left and right”. FIG. 1 illustrates a windshield viewed from the inside of the vehicle. That is, the back side of the sheet of FIG. 1 is the outside of the vehicle, and the front side of the sheet of FIG. 1 is the inside of the vehicle.

  The windshield includes a substantially rectangular window glass 10 and is installed on the vehicle body in an inclined state. The inner surface 130 of the window glass 10 facing the vehicle interior is provided with a shielding layer 110 that shields the field of view from the outside of the vehicle, and the photographing device 2 is arranged so as not to be seen from the outside of the vehicle by the shielding layer 110. ing. However, the photographing device 2 is a camera for photographing a situation outside the vehicle. For this reason, the shielding layer 110 is provided with a photographing window at a position corresponding to the photographing device 2, and a situation outside the vehicle can be photographed by the photographing device 2 disposed inside the vehicle.

  An image processing device 3 is connected to the photographing device 2, and a photographed image acquired by the photographing device 2 is processed by the image processing device 3. The imaging device 2 and the image processing device 3 constitute an in-vehicle system 5, and the in-vehicle system 5 can provide various information to the passenger according to the processing of the image processing device 3. Hereinafter, each component will be described.

<1-2. Glass plate>
<1-2-1. Configuration of glass plate / Configuration of laminated glass>
The window glass 10 can have various configurations. For example, the window glass 10 can be configured of laminated glass having a plurality of glass plates, or can be configured of a single glass plate. In the case of using laminated glass, for example, it can be configured as shown in FIG. FIG. 3 is a sectional view of the laminated glass.

  As shown in the figure, the laminated glass 10 includes an outer glass plate 11 and an inner glass plate 12, and a resin intermediate film 13 is disposed between the glass plates 11 and 12. First, the outer glass plate 11 and the inner glass plate 12 will be described. As the outer glass plate 11 and the inner glass plate 12, known glass plates can be used, and they can be formed of heat ray absorbing glass, general clear glass, green glass, or UV green glass. However, these glass plates 11 and 12 need to realize visible light transmittance in accordance with the safety standards of the country where the automobile is used. For example, the required solar radiation absorption rate can be ensured by the outer glass plate 11, and the visible light transmittance can be adjusted by the inner glass plate 12 so as to satisfy safety standards. Below, an example of clear glass, heat ray absorption glass, and soda-lime-type glass is shown.

(Clear glass)
SiO ₂ : 70 to 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 mass%
R ₂ O: 13 to 15% by mass (R is an alkali metal)
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.08~0.14 wt%

(Heat ray absorbing glass)
The composition of the heat-absorbing glass, for example, based on the composition of the clear glass, the proportion of the total iron oxide in terms of _{Fe 2 O 3 (T-Fe} 2 O 3) and 0.4 to 1.3 wt%, CeO ₂ ratio as 0-2 mass%, the proportion of TiO ₂ and 0 to 0.5 wt%, framework component of the glass (mainly, SiO ₂ and Al ₂ O ₃₎ to T-Fe ₂ O _3, CeO _The composition can be reduced by an increase of ₂ and TiO ₂ .

(Soda-lime 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 Na ₂ O: 10-18% 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
SO ₃ : 0.05 to 0.3% by mass
B ₂ O ₃ : 0 to 5% by mass
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.02~0.03 wt%

  Although the thickness of the laminated glass which concerns on this embodiment is not specifically limited, From a viewpoint of weight reduction, it is preferable that the sum total of the thickness of the outer side glass plate 11 and the inner side glass plate 12 shall be 2.4-3.8 mm. It is more preferable to set it as 2.6-3.4 mm, and it is especially preferable to set it as 2.7-3.2 mm. Thus, since it is necessary to reduce the total thickness of the outer glass plate 11 and the inner glass plate 12 for weight reduction, the thickness of each glass plate is not particularly limited, 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 mainly needs durability and impact resistance against external obstacles. For example, when this laminated glass is used as a windshield of an automobile, the outer glass plate 11 has impact resistance performance against flying objects such as pebbles. is necessary. On the other hand, as the thickness is larger, the weight increases, which is not preferable. From this viewpoint, the thickness of the outer glass plate 11 is preferably 1.8 to 2.3 mm, and more preferably 1.9 to 2.1 mm. Which thickness is adopted can be determined according to the application of the glass.

  Although the thickness of the inner side glass plate 12 can be made equivalent to the outer side glass plate 11, for example, thickness can be made smaller than the outer side glass plate 11 for weight reduction of a laminated glass. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.0 mm, more preferably 0.8 to 1.6 mm, and particularly preferably 1.0 to 1.4 mm. preferable. Furthermore, it is preferable that it is 0.8-1.3 mm. Which thickness is used for the inner glass plate 12 can be determined according to the purpose of the glass.

  Moreover, the shape of the outer side glass plate 11 and the inner side glass plate 12 which concerns on this embodiment has comprised the curved shape. Here, an example of a method for measuring the thickness of the glass plate (laminated glass) 1 will be described. First, about a measurement position, as shown in FIG. 4, it is two places up and down on the center line S extended in the up-down direction at the center of the left-right direction of a glass plate. The measuring instrument is not particularly limited, and for example, a thickness gauge such as SM-112 manufactured by Teclock Co., Ltd. can be used. At the time of measurement, it is arranged so that the curved surface of the glass plate is placed on a flat surface, and the end of the glass plate is sandwiched by the thickness gauge and measured.

  The base plate of the glass plate is manufactured by a known float method, and then cut or bent to form the above glass plate. The float process is a manufacturing method in which a glass plate is formed by pouring a glass substrate in a predetermined direction on molten tin. On the surface of the glass plate formed by the float method, unevenness occurs along the flow direction of the glass substrate, so that uneven stripes extending along this direction occur, resulting in image distortion described later. May occur. For example, on the window glass 10 of FIG. 1 cut so that the flow direction of the glass substrate is the short side (longitudinal) direction, a streak extending along the short side (longitudinal) direction is formed. Unevenness is formed in the long side direction.

<1-2-2. Laminated glass interlayer>
The intermediate film 13 is formed of at least one layer. For example, as shown in FIG. 3, the intermediate film 13 can be configured by three layers in which a soft core layer 131 is sandwiched between harder outer layers 132. However, it is not limited to this configuration, and may be formed of a plurality of layers including the core layer 131 and at least one outer layer 132 disposed on the outer glass plate 11 side. For example, two layers of the intermediate film 13 including the core layer 131 and one outer layer 132 disposed on the outer glass plate 11 side, or two or more outer layers 132 are disposed on both sides around the core layer 131. The intermediate film 13 or the intermediate film 13 in which one outer layer 132 is disposed on one side and two or more outer layers 132 are disposed on the other side with the core layer 131 in between may be used. When only one outer layer 132 is provided, the outer layer 132 is provided on the outer glass plate 11 side as described above, but this is to improve the resistance to breakage against an external force from outside the vehicle or outside. Further, when the number of outer layers 132 is large, the sound insulation performance is also enhanced.

  As long as the core layer 131 is softer than the outer layer 132, the hardness thereof is not particularly limited. Although the material which comprises each layer 131,132 is not specifically limited, For example, a material can be selected on the basis of a Young's modulus. Specifically, at a frequency of 100 Hz and a temperature of 20 degrees, it is preferably 1 to 20 MPa, more preferably 1 to 18 MPa, and particularly preferably 1 to 14 MPa. With such a range, it is possible to prevent the STL (sound transmission loss) from being lowered in a low frequency range of approximately 3500 Hz or less. On the other hand, the Young's modulus of the outer layer 132 is preferably large in order to improve sound insulation performance in a high frequency region, as will be described later, and is 560 MPa or more, 600 MPa or more, 650 MPa or more, 700 MPa or more at a frequency of 100 Hz and a temperature of 20 degrees. It can be set to 750 MPa or more, 880 MPa or more, or 1300 MPa or more. On the other hand, the upper limit of the Young's modulus of the outer layer 132 is not particularly limited, but can be set from the viewpoint of workability, for example. For example, it is empirically known that when it becomes 1750 MPa or more, workability, particularly cutting becomes difficult.

  Moreover, as a specific material, the outer layer 132 can be comprised by polyvinyl butyral resin (PVB), for example. Polyvinyl butyral resin is preferable because it is excellent in adhesiveness and penetration resistance with each glass plate. On the other hand, the core layer 131 can be made of, for example, an ethylene vinyl acetate resin (EVA) or a polyvinyl acetal resin that is softer than the polyvinyl butyral resin constituting the outer layer. By sandwiching the soft core layer between them, the sound insulation performance can be greatly improved while maintaining the same adhesion and penetration resistance as the single-layer resin intermediate film.

  In general, the hardness of the polyvinyl acetal resin is controlled by (a) the degree of polymerization of the starting polyvinyl alcohol, (b) the degree of acetalization, (c) the type of plasticizer, (d) the addition ratio of the plasticizer, etc. Can do. Therefore, by appropriately adjusting at least one selected from these conditions, a hard polyvinyl butyral resin used for the outer layer 132 and a soft polyvinyl butyral resin used for the core layer 131 even if the same polyvinyl butyral resin is used. Can be made separately. Furthermore, the hardness of the polyvinyl acetal resin can also be controlled by the type of aldehyde used for acetalization, coacetalization with a plurality of aldehydes, or pure acetalization with a single aldehyde. Although it cannot generally be said, the polyvinyl acetal resin obtained by using an aldehyde having a large number of carbon atoms tends to be softer. Therefore, for example, when the outer layer 132 is made of polyvinyl butyral resin, the core layer 131 has an aldehyde having 5 or more carbon atoms (for example, n-hexylaldehyde, 2-ethylbutyraldehyde, n-heptylaldehyde, n-octylaldehyde) can be used as the polyvinyl acetal resin obtained by acetalization with polyvinyl alcohol. In addition, when predetermined | prescribed Young's modulus is obtained, it is not limited to the said resin.

  The total thickness of the intermediate film 13 is not particularly limited, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferred. Moreover, the thickness of the core layer 131 is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 0.6 mm. On the other hand, the thickness of each outer layer 132 is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 1.0 mm. In addition, the total thickness of the intermediate film 13 can be made constant, and the thickness of the core layer 131 can be adjusted therein.

  The thickness of the core layer 131 and the outer layer 132 can be measured as follows, for example. First, the cross section of the laminated glass is enlarged and displayed by 175 times with a microscope (for example, VH-5500 manufactured by Keyence Corporation). And the thickness of the core layer 131 and the outer layer 132 is specified visually, and this is measured. At this time, in order to eliminate visual variation, the number of measurements is set to 5 times, and the average value is defined as the thickness of the core layer 131 and the outer layer 132. For example, an enlarged photograph of a laminated glass as shown in FIG. 5 is taken, and the core layer and the outer layer 132 are specified in this and the thickness is measured.

  Note that the thickness of the core layer 131 and the outer layer 132 of the intermediate film 13 does not have to be constant over the entire surface. For example, for the prevention of double image generation in the head-up display device or in the first embodiment described later. In order to be used for the laminated glass to be used, the whole or a part thereof can be wedge-shaped. In this case, the thicknesses of the core layer 131 and the outer layer 132 of the intermediate film 13 also have partially different values, but the “thickness” of each layer in the above-described intermediate film 13 is the portion with the smallest thickness. When the intermediate film 13 is wedge-shaped, the outer glass plate and the inner glass plate are not strictly arranged in parallel, but such arrangement is also included in the glass plate in the present invention. That is, in the present invention, for example, the arrangement of the outer glass plate and the inner glass plate when the intermediate film 13 using the core layer 131 or the outer layer 132 whose thickness is increased at a change rate of 3 mm or less per 1 m is used. including.

  The method for producing the intermediate film 13 is not particularly limited. For example, the resin component such as the polyvinyl acetal resin described above, a plasticizer, and other additives as necessary are blended and kneaded uniformly, and then each layer is collectively And a method of laminating two or more resin films prepared by this method by a pressing method, a laminating method or the like. The resin film before lamination used in a method of laminating by a press method, a laminating method or the like may have a single layer structure or a multilayer structure. Further, the intermediate film 13 can be formed of a single layer in addition to the above-described plural layers.

<1-3. Shielding layer>
Next, the shielding layer 110 will be described. As illustrated in FIGS. 1 and 2, in the present embodiment, the shielding layer 110 is laminated on the inner surface 130 on the inner side of the vehicle and is formed along the peripheral edge of the window glass 10. Specifically, as illustrated in FIG. 1, the shielding layer 110 according to the present embodiment protrudes in a rectangular shape downward from the peripheral region 111 along the peripheral portion of the window glass 10 and the upper side portion of the window glass 10. The protruding region 112 can be divided. The peripheral region 111 shields light incident from the peripheral portion of the windshield 1. On the other hand, the protruding region 112 prevents the photographing device 2 disposed in the vehicle from being seen from outside the vehicle.

  However, if the shielding layer 110 blocks the imaging range of the imaging device 2, the imaging device 2 cannot capture the situation in front of the vehicle. Therefore, in the present embodiment, a rectangular imaging window 113 is provided in a position corresponding to the imaging device 2 in the protruding region 112 of the shielding layer 110 so that the imaging device 2 can be outside the vehicle.

  The photographing window 113 is an area where the material of the shielding layer 110 is not laminated, and is configured to have a visible light transmittance that allows the photographing apparatus 2 to photograph a situation outside the vehicle. For example, the imaging window 113 is configured so that the visible light transmittance is 70% or more. Moreover, this transmittance | permeability can be measured by the spectroscopic measurement method prescribed | regulated to JISZ8722 as prescribed | regulated by JISR3212 (3.11 visible light transmittance | permeability test). In the present embodiment, the imaging window 113 is provided in the protruding area 112. That is, the imaging window 113 is provided independently from the non-shielding region 120 on the inner side in the plane direction than the shielding layer 110. In the photographing window 113, a region through which light incident on the photographing device passes corresponds to a passage region of the present invention.

  Further, when the distance between vehicles is measured using a laser radar or the like instead of the imaging device 2, the transmittance of the glass plate is 20% or more and 80% or less for light (infrared rays) having a wavelength of 850 to 950 nm. It is said that it is useful that it is at least 20% or more and 60% or less. The measuring method of the transmittance can be UV3100 (manufactured by Shimadzu Corporation) as a measuring device according to JIS R3106. Specifically, the transmission of light in one direction irradiated at an angle of 90 degrees with respect to the surface of the glass plate is measured.

  Note that the non-shielding region 120 is a region where the material of the shielding layer 110 is not laminated, like the imaging window 113. The driver and a companion sitting in the passenger seat confirm the traffic conditions outside the vehicle through the non-shielding area 120. Therefore, the non-shielding region 120 is configured to have a visible light transmittance so that at least the traffic situation outside the vehicle can be visually observed.

  Next, the material of the shielding layer 110 will be described. The material of the shielding layer 110 may be appropriately selected according to the embodiment as long as the field of view from the outside of the vehicle can be shielded. For example, dark ceramics such as black, brown, gray, and dark blue are used. Also good.

  When black ceramic is selected as the material of the shielding layer 110, black ceramic is laminated on the peripheral portion on the inner surface 130 of the window glass 10 by screen printing or the like, and the ceramic laminated with the window glass 10 is heated. Thereby, the shielding layer 110 can be formed on the peripheral edge of the window glass 10. Moreover, when printing black ceramic, the area | region which does not print black ceramic partially is provided. As a result, the photographing window 113 can be formed. Note that various materials can be used for the ceramic used for the shielding layer 110. For example, a ceramic having the composition shown in Table 1 below can be used for the shielding layer 110.

<1-4. 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. 6 illustrates the configuration of the in-vehicle system 5. As illustrated in FIG. 6, the in-vehicle system 5 according to the present embodiment includes the imaging device 2 and an image processing device 3 connected to the imaging device 2.

  The image processing device 3 is a device that processes a captured image acquired by the imaging device 2. The image processing apparatus 3 includes, for example, general hardware such as a storage unit 31, a control unit 32, and an input / output unit 33 connected by a bus as a hardware configuration. However, the hardware configuration of the image processing apparatus 3 does not have to be limited to such an example, and the specific hardware configuration of the image processing apparatus 3 is appropriately added or omitted according to the embodiment. And additions are possible.

  The storage unit 31 stores various data and programs used in processing executed by the control unit 32 (not shown). The storage unit 31 may be realized, for example, by a hard disk or a recording medium such as a USB memory. 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 referred to as an auxiliary storage device.

  As described above, the window glass 10 is disposed in an inclined posture with respect to the vertical direction and is curved. And the imaging device 2 images the situation outside the vehicle through such a window glass 10. Therefore, the captured image acquired by the imaging device 2 is deformed according to the attitude, shape, refractive index, optical defect, and the like of the window glass 10. In addition, aberration inherent to the camera lens of the photographing apparatus 2 is also added. Therefore, the storage unit 31 may store correction data for correcting an image deformed due to the aberration of the window 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 processing of the processor. Etc.). ROM, RAM, and the like may be referred to as a main storage device in the sense that they are arranged in an address space handled by the processor in the control unit 32. The control unit 32 functions as the image processing unit 321 by executing various data and programs stored in the storage unit 31.

  The image processing unit 321 processes a captured image acquired by the imaging device 2. The processing of the captured image can be selected as appropriate 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, the window glass 10 is a windshield, and the imaging device 2 captures the situation in front of the vehicle. Therefore, the image processing unit 321 may further determine whether or not a living creature such as a human is captured in front of the vehicle based on the subject recognition. When a person is captured in front of the vehicle, the image processing unit 321 may output a warning message by a predetermined method. Further, for example, the image processing unit 321 may perform a predetermined processing on the captured image. Then, the image processing unit 321 may output the processed photographed 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 an apparatus existing outside the image processing apparatus 3. The input / output unit 33 is, for example, an interface for connecting to a user interface or an interface such as USB (Universal Serial Bus). In the present embodiment, the image processing apparatus 3 is connected to the photographing apparatus 2 via the input / output unit 33 and acquires a photographed image photographed by the photographing apparatus 2.

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

<1-5. Windshield manufacturing method>
Next, the manufacturing method of the windshield 1 which concerns on this embodiment is demonstrated using FIG. FIG. 7 schematically illustrates a molding process of the window glass 10 of the windshield 1 according to the present embodiment. In addition, the manufacturing method of the windshield 1 demonstrated below is only an example, and each step may be changed as much as possible. Further, in the manufacturing process described below, steps can be omitted, replaced, and added as appropriate according to the embodiment.

  As illustrated in FIG. 7, in this production line, the heating furnace 80 and the molding apparatus 82 are arranged in this order from upstream to downstream. And the roller conveyor 81 is arrange | positioned from the heating furnace 80 to the shaping | molding apparatus 82 and its downstream, The window glass 10 used as a process target is conveyed by this roller conveyor 81. FIG. Note that the window glass 10 is formed into a flat plate shape by the above-described float method, and after the shielding layer 11 is laminated on the inner surface 130, the window glass 10 is carried into the heating furnace 80.

  The heating furnace 80 can have various configurations. For example, the heating furnace 80 can be an electric heating furnace. The heating furnace 80 includes a rectangular tube-shaped furnace main body that is open at the upstream and downstream ends, and a roller conveyor 81 is disposed in the interior from upstream to downstream. Heaters (not shown) are arranged on the upper surface, the lower surface, and the pair of side surfaces of the inner wall surface of the furnace body, and the temperature at which the window glass 10 passing through the heating furnace 80 can be formed, for example, the softening point of the glass Heat to near.

  The molding apparatus 82 is configured to press the window glass 10 with an upper mold 821 and a lower mold 822 and mold the glass into a predetermined shape. The upper mold 821 has a curved surface that protrudes downward so as to cover the entire upper surface of the window glass 10, and is configured to be movable up and down. The lower mold 822 is formed in a frame shape corresponding to the peripheral edge of the window glass 10, and the upper surface thereof has a curved surface shape corresponding to the upper mold 821. With this configuration, the window glass 10 is press-molded between the upper mold 821 and the lower mold 822 to be molded into a final curved shape. A roller conveyor 81 is disposed in the frame of the lower mold 822, and the roller conveyor 81 can be moved up and down so as to pass through the frame of the lower mold 822. And although illustration is abbreviate | omitted, the slow cooling apparatus (illustration omitted) is arrange | positioned in the downstream of the shaping | molding apparatus 82, and the shape | molded glass plate is cooled.

  Here, the heating furnace 80 is heated at about 650 degrees. At this time, since the ceramic that is the material of the shielding layer 110 is a dark color such as black, the amount of heat absorbed is smaller than that of the area where the ceramic is not laminated, for example, the area of the imaging window 113 and the non-shielding area 120. Become more. And since the ceramic which forms the shielding layer 110 has a thermal expansion coefficient different from the window glass 10, a compressive stress and a tensile stress generate | occur | produce in the area | region in which the shielding layer 110 is formed at the time of this shaping | molding process. Therefore, a distorted region in which distortion of the degree described later is generated is formed at the peripheral portion of the imaging window 113 and the boundary portion between the non-shielding region 120 and the shielding layer 110.

  Therefore, as described above, the size of the photographing window may be set in consideration of the width of the distortion region. For example, assuming that the width of the distortion area is 8 mm, a range in which the periphery of the light passage area to the camera is enlarged by 8 mm in all directions is set as the minimum size of the photographing window 113. Thus, the size of the photographing window 113 can be formed relatively small while avoiding the influence of distortion on the photographing device 2.

  The roller conveyor 81 as described above is a well-known one, and a plurality of rollers 811 whose both ends are rotatably supported are arranged at predetermined intervals. There are various methods for driving each roller 811. For example, a sprocket can be attached to the end of each roller 811 and a chain can be wound around each sprocket to drive it. And the conveyance speed of the window glass 10 can also be adjusted by adjusting the rotational speed of each roller 811. FIG. The lower mold 822 of the molding apparatus 82 may be in contact with the entire surface of the window glass 10. In addition, as long as the shaping | molding apparatus 82 shape | molds the window glass 10, the form of an upper mold | type and a lower mold | type is not specifically limited.

<2. First Embodiment>
Next, the windshield which concerns on 1st Embodiment of this invention is demonstrated, referring FIGS. 8-10. The shielding layer 110 and the imaging device 2 are as described above unless otherwise specified, and are omitted from the drawings. This point is the same also in the following second embodiment. Therefore, the specific configuration of the first embodiment will be described below.

  As described above, the window glass 10 used in the present embodiment is made of laminated glass manufactured by the float process. As described above, the conventional laminated glass has a large wavefront defect of light that has passed through the laminated glass because the glass plate having uneven stripes formed on the surface is bonded by the float process. As a result, irregular irregularities of the transmitted wavefront are increased, resulting in an increase in lens action, and it is found that an image generated by light incident on the imaging device 2 through the laminated glass is distorted. ing.

  As described above, the conventional laminated glass has a problem that the lens action is increased. However, in the following, first, how optically is caused by the unevenness of the surface of the glass plate manufactured by the float process. The configuration of the first embodiment for suppressing the influence will be described in detail. However, in the following, for convenience of explanation, it may be described as a single plate on the drawings.

FIG. 8 is a schematic diagram showing a case where a parallel luminous flux passes through the window glass 10 having a spherical convex defect portion 101 having a width L and a height difference d. As shown in the figure, the light ray passing through the defect portion 101 changes its direction and becomes an aberration of the light ray. By the way, since the essence of light is “wave”, when the same situation as FIG. 8 is expressed by “wavefront”, FIG. 9 is obtained, and the defect portion 101 causes disturbance of the spherical wavefront (wavefront aberration). In the case of FIG. 9, the width of the defect portion is L, the height difference of the wavefront aberration is d ′, the radius of curvature of the wavefront aberration is R, the half angle formed by the wavefront aberration portion viewed from the center of curvature is θ, and the window glass 10 When the refractive index of n is n, the following relational expression holds.
d ′ = (n−1) × d (1)
Rsin θ = L / 2
d ′ = R−R cos θ

From the above relationship, R = L ² / 8d ′ by small angle approximation.
It becomes. When the spherical wave of the defective portion travels, the focal point is focused at the position of the distance R, so this defective portion is a convex lens having the focal length R. The lens action D can be expressed in dpt units (dioptre, 1 / m) by taking the reciprocal of R.
D = 8d ′ / L ² (2)

  As an example, when the amount of wavefront aberration is d ′ = 1λ (the wavelength λ is 632.8 nm) and L = 10 mm, the lens action is 50.6 mdpt when applied to the above equation (2). However, mdpt means “mill-dioptre”.

  By the way, in the case of a windshield that is actually used for a passenger car or the like, a surface shape defect (deviation from the design value) is caused by a “spherical component” that is a spherical convex surface or a concave surface, and a curvature that varies depending on the direction. Point aberration) component (astigmatism component) ". Furthermore, since irregular irregular streaks extending along the flow direction of the glass substrate are generated on the surface of the above-mentioned float glass, streaky irregular wavefront aberration due to the irregular irregularities is also generated. That is, the wavefront aberration that occurs when light passes through the surface of the windshield is a composite of spherical components, asphalt components, and irregular components, as shown in FIG.

  Among them, the spherical component and the asphalt component are gentle undulations on the glass surface, so that the lens action is small, and correction can be made relatively easily by correcting the image data of the information equipment. However, the irregular component is difficult to correct as described above and causes a strong lens action locally. A strong lens action greatly changes the direction of the light beam, which causes, for example, local displacement (irregular distortion) of the camera image. Therefore, it is preferable to make the irregular component as small as possible.

As shown in Examples and Comparative Examples described later, the irregular uneven streaks on the surface of the float glass have a structure in which strip-like convex lenses and concave lenses having a width of approximately 5 to 20 mm are arranged in a specific direction. Here, assuming that the total width of a single lens portion is 10 mm and the lens action is 10 mdpt (focal length 100 m), the bending angle of the light beam at the end of the lens portion is from tan ⁻¹ (0.005 / 100) to 0. 05mrad.

On the other hand, when the effective diameter of an objective lens used in optical equipment is Amm, the focal length is fmm, and the wavelength of light is λ, the angular resolution of the image by the objective lens is defined by the Airy disk diameter B, which is the theoretical minimum spot diameter. Then
B = 1.22λ / (A / 2f)
Therefore, the angular resolution is tan ⁻¹ (B / f) = tan ⁻¹ (2.44λ / A).
It is. Here, from the viewpoint of weight and size, if the maximum diameter of an objective lens mounted on an automobile is 30 mm and λ is visible light of 587.6 nm, the angular resolution is 0.048 mrad.

  From the above results, it can be seen that if the absolute value of the lens action is suppressed to about 10 mdpt or less, the irregular light beam bending angle in the windshield can be set to a negligible level below the angular resolution of the objective lens. Under such circumstances, the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when light passes through the imaging window 13 is 10 mdpt or less, preferably 10 mdpt. If it is less than, more preferably 8 mdpt or less, particularly preferably 6 mdpt or less, the performance of the objective lens can be ensured.

  On the other hand, as will be described later in the Examples section, in the glass plate manufactured by the float method, the irregular component obtained by removing the spherical component and the asphalt component from the wavefront aberration has a width of approximately 5 to 20 mm. It has a shape of an elongated convex lens or concave lens, and the absolute value of the lens action is 10 mdpt or more.

  The range L for evaluating the lens action is preferably set to a value of approximately 5 to 20 mm in accordance with the size of the lens portion, and in order to simplify the evaluation, a typical value is set to 10 mm. preferable. A convex portion or concave portion having a size of 5 mm or less can be ignored because the wavefront aberration amount itself is smaller than the Rayleigh limit value (λ / 4), which is a criterion for no aberration, even if the lens action is strong. For example, taking a lens portion corresponding to L = 3 mm and 30 mdpt as an example, the amount of wavefront aberration is 0.034 μm from the above equation (2). Since the wavelength λ of visible light is 0.4 to 0.7 μm, it is much smaller than the limit value of Rayleigh.

  For example, a fine unevenness in a range of 5 mm or less as shown in FIG. 22 described later may be 10 mdpt or more due to apparent calculation. However, even if the lens action is strong, the small convex portion or concave portion can be ignored because the wavefront aberration amount itself is smaller than the Rayleigh limit value (λ / 4) which is a criterion for no aberration. For example, taking a lens portion corresponding to L = 3 mm and 30 mdpt as an example, the amount of wavefront aberration is 0.034 μm from the above equation (2). Since the wavelength λ of visible light is 0.4 to 0.7 μm, it is much smaller than the limit value of Rayleigh. Therefore, the range L for evaluating the lens action is preferably set to a value of approximately 5 to 20 mm. In order to simplify the evaluation, a typical value of 10 mm is preferable.

  Therefore, if the front and back surfaces of the window glass 10 are molded so that the absolute value of the lens action due to irregular irregularities is smaller than 10 mdpt for the area corresponding to the shooting window 113 (passing area) of the window glass 10, Even if it is glass, the bad influence on image formation can be suppressed. For this purpose, for example, by polishing the surface of the window glass 10, the irregular uneven lens action can fall within the above range. However, other methods may be used as long as the lens action can be reduced.

  FIG. 11 shows an example of a cross section of the window glass 10, but as shown in FIG. 11, the passing area corresponding to the photographing window 113 can be polished on both surfaces of the window glass 10. Since the purpose is to smooth irregular irregularities and reduce the lens action, the polishing amount may be such that the radius of curvature of the glass surface is hardly changed, for example, about 1 to 5 μm or more. In addition, when using the laminated glass as described above, the lens action may be set within the above range for both the outer surface of the outer glass plate and the inner surface of the inner glass plate. Even if only one side is polished for cost or process reasons, there is a partial effect.

  Further, when the surface and the back surface of the window glass 10 are made substantially parallel by increasing the polishing amount, the spherical component and the asphalt component on the glass surface are also eliminated, so that the wavefront aberration due to the transmission of the window glass 10 is further suppressed. Can do. In addition, when using laminated glass as the window glass 10, what is necessary is just to make it the vehicle outside surface of an outer side glass plate, and the vehicle inner side surface of an inner side glass plate parallel. However, the term “parallel” does not have to be strictly parallel. For example, there may be an angle of about ± 0.08 degrees.

  This point will be discussed with reference to FIGS. The window glass 10 of the windshield shown in FIG. 12 is formed with a photographing window 113 (passage area) in which the vehicle outer surface 1131 and the vehicle inner surface 1132 are not parallel.

Subsequently, the model of FIG. 12 was produced and simulated. The model is as shown in FIG. The calculation procedure is as described above, but the thickness is set so that the taper angle φ is formed on the inner surface side of the imaging window 113. Then, as shown in FIG. 12, nine evaluation points are arranged on the target T. The evaluation points are the following nine points when the coordinates of the center of the rectangular target are (0, 0). The unit of coordinates is mm. The X direction is the left-right direction, and the Y direction is the up-down direction.
Point A: (x, y) = (− 400, 300)
Point B: (x, y) = (− 400, 0)
Point C: (x, y) = (− 400, −300)
Point D: (x, y) = (0,300)
Point E: (x, y) = (0, 0)
Point F: (x, y) = (0, −300)
Point G: (x, y) = (400, 300)
Point H: (x, y) = (400, 0)
Point I: (x, y) = (400, −300)

  The distance Q between the entrance pupil of the photographing apparatus (camera) and the center of the passage area on the inner surface 1132 of the glass plate 10 was set to 0 mm.

The optical calculation software OSLO premium Edition Release 6.3 (manufactured by Lambda Research Corp., USA) was used for the following calculations. The same applies to each embodiment described later. Under the above conditions, the angles of the principal rays exiting from each evaluation point and entering the entrance pupil in the Y direction and the X direction are determined when there is no glass plate (θy ₀ , θx ₀ ) and when there is a glass plate (θy , Θx), respectively. However, the chief ray from the point E (0, 0) on the target T was set to zero inclination as a reference for the angle.

Next, the distortion amount in the Y direction and the X direction due to the transmission of the glass plate was set for each evaluation point as follows.
Y-direction distortion amount: DSy = (tan θy−tan θy ₀ ) / tan θy ₀
X direction distortion amount: DSx = (tan θx−tan θx ₀ ) / tan θx ₀

  Subsequently, the thickness was set to change toward the inner surface 1132 side of the photographing window 113 so that the taper angle φ was obtained. Then, the sum of the distortion amounts DSy and DSx at the nine evaluation points was obtained, and the taper angle φ at which the sum was minimized was determined. When the taper angle φ is a positive value, the thickness Tg of the imaging window 113 increases as it goes downward.

Table 2 shows values of the optimum taper angle φ obtained when the calculation conditions are changed as follows.
Installation angle: θ = 40, 50, 60, 70 (°)
-Thickness of the photographing window 113 at the center of the passing area: Tg = 1.0, 2.0, 4.0, 6.0 (mm)
The average refractive index of the photographing window 113: ng = 1.45, 1.52, 1.70

  The distance Q between the entrance pupil of the imaging device (camera) and the center of the passing area on the surface 1132 on the vehicle inner side of the imaging window 113 was set to 0 mm.

Subsequently, an approximate expression is obtained from the relationship between θ, Tg, ng and φ shown in Table 2 as follows.
φ ′ = (K1 · θ ² −K2 · θ + K3) Tg · ng / (ng−1) (K1, K2, and K3 are constants)

Here, the conditions under which the value of Σ {(φ′−φ) ² } in Table 2 is minimized are as follows.
K1 = 1.549X10 ⁻⁶
K2 = 3.377 × 10 ⁻⁴
K3 = 1.666X10 ^-2

  Table 2 also shows the values of φ ′ and φ′−φ calculated using the constants K1 to K3. The error | φ′−φ | by the approximate expression is 0.0026 ° at the maximum.

Further, the preferred range of φ is as follows. For example, when θ = 60, Tg = 4.0, and nt = 1.52, the distortion amount (x direction and y direction) at each measurement point (A to I) with respect to the value of φ is as shown in FIG. Become. Note that some measurement points (By, Ex, Ey, etc.) are omitted because the distortion is close to zero due to symmetry. As shown in FIG. 14, it can be seen that the distortion at each point is the minimum (optimum value) around φ = 0.02 °. In addition, when it is desired to set the amount of distortion to approximately ± 1%, which is a good range, it is understood that the value of φ only needs to be in the range of ± 0.08 ° from the optimum value (0.02 °). Therefore, the preferable range of the taper angle φ is as follows.
E−0.08 <φ <E + 0.08
However, E = (K1 · θ ² −K2 · θ + K3) Tg · ng / (ng−1), which is based on the above-described approximate expression.

The optimum value of 0.02 degrees is a very small value. Therefore, if the angle formed between the vehicle inner surface 1132 and the vehicle outer surface 113 of the photographing window 113 is approximately ± 0.08 degrees, the distortion amount is ± 1% or less.

<3. Second Embodiment>
Next, a windshield according to a second embodiment of the present invention will be described with reference to FIG. As described above, it has been found that in the conventional laminated glass, the lens action is increased, and the image generated by the light incident on the photographing apparatus 2 through the laminated glass is distorted.

  Therefore, in the windshield according to the present embodiment, as shown in FIG. 15A, through holes 18 are formed in the intermediate film 13 and the inner glass plate 12 at least in the passage region of light incident on the imaging device 2. Yes. That is, only the outer glass plate 11 is arranged in the passage region.

  As described above, when the through hole 18 is formed in the intermediate film 13 and the inner glass plate 12 in the light passage region, the light passes through only the outer glass plate 11 and enters the photographing apparatus 2. Therefore, as compared with the laminated glass of FIG. 35, the lens action due to the defect of the transmitted wavefront described above is greatly reduced. As a result, distortion of the formed image can be suppressed. Note that image distortion can be similarly suppressed by leaving only the inner glass plate 12 and forming through holes in the outer glass plate 11 and the intermediate film 13.

  Or it can also be as follows. That is, as shown in FIG. 15B, a through hole 18 is formed in the intermediate film 13 in the light passage region. Thereby, the air layer 19 is formed between the outer side glass plate 11 and the inner side glass plate 12 in a passage area | region in a laminated glass. Then, the light from the outside of the vehicle passes through the outer glass plate 11, the air layer 19, and the inner glass plate 12 and enters the photographing apparatus 2. As described above, since the incident light and the emitted light are substantially parallel in the glass plate alone, the light incident on the outer glass plate 11 is emitted substantially in parallel with this and travels straight through the air layer 19 and then the inner glass. The light enters the plate 12 and exits in parallel with this. Therefore, the incident light on the outer glass plate 11 and the outgoing light from the inner glass plate 12 are substantially parallel and have little direction change. As a result, the lens action due to the defect of the transmitted wavefront is reduced, and distortion in the image formed by the photographing apparatus 2 is suppressed.

<4. Modification>
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning.

<4-1>
In addition to the cameras shown in the above embodiment, laser radar and other devices that irradiate light and receive reflected light to measure distance between vehicles, etc. It is also possible to use a device that does this. Moreover, it can also be used for an apparatus that displays information on a window glass by light irradiated on the window glass, such as a head-up display, thereby providing information. In any case, the configuration according to the first and second embodiments may be provided in a region where light passes or is irradiated, that is, a passing region.

<4-2>
In the example shown in FIG. 15B in the second embodiment, the air layer 19 is formed in the passage region. When such an air layer 19 is formed, the glass in the transmission region of the windshield is formed. The interface between the plate and air increases from two to four. Since the refractive index difference between the glass plate and air is large and Fresnel reflected light is generated at the interface, the configuration in FIG. 15B is compared with the configuration in FIGS. 11 and 15A where the air interface is two surfaces. As a result, the contrast of the image in the photographing apparatus 2 may be deteriorated. In contrast, as shown in FIG. 16, in the inner glass plate 12, an antireflection film 500 can be provided on the vehicle outer surface and the vehicle inner surface in a region facing the air layer 19. Thereby, reflection of the light on the inner side glass plate 12 can be prevented, and a double image and image distortion can be prevented. Such an antireflection film 500 may be provided on either the vehicle outer side or the vehicle inner side of the inner glass plate 12 or may be provided on a part of the passage region. Further, a similar antireflection film may be provided on one side or both sides of the outer glass plate 11.

Various modes are possible for the antireflection film. For example, the following can be used. That is, the antireflection film is divided into several groups according to the number of layers. That is, a single layer configuration, a two layer configuration, a three layer configuration, and a multilayer configuration. First, the antireflection film having a single layer structure is formed on a glass plate as a transparent substrate, for example, with a refractive index lower than that of the glass plate. Examples of practical low refractive index materials include MgF ₂ and SiO ₂ . In such a single layer configuration, since the antireflection effect is not sufficient, an antireflection film having a two-layer configuration in which two layers of a refractive index layer higher than the refractive index of the glass plate and a low refractive index layer are combined is used. .

  Further, when the antireflection effect is not sufficient even with a two-layer structure, a three-layer structure including a low-refractive index layer, a medium-refractive index layer, and a high-refractive index layer, or an antireflection film including four or more layers is also possible Used.

In any case, a refractive index layer lower than the refractive index of the transparent substrate is formed on the uppermost layer of the antireflection film. For example, as the low refractive index material for the glass plate, only the above-described MgF ₂ and SiO ₂ are practical. However, MgF ₂ has poor durability and weather resistance, and cannot withstand the heating in the bending process of the glass plate. Therefore, the only material applicable for such use is SiO ₂ .

  Here, considering the case where an antireflection film is applied to a bent glass plate for a vehicle, an antireflection film is formed in a flat state and then heated to bend the glass plate from the uniformity of the film thickness. Is preferred.

Calculates the refractive index of a high refractive index material combined with SiO ₂ with n ₂ = 1.46, which is a low refractive index material, in an antireflection film having a relatively simple film configuration and a large antireflection effect. Try it. The relationship between n ₁ and n ₂ is given by the following equation, where n _g is the refractive index of glass (= 1.52) and n ₃ is the refractive index of air (= 1.0).
n ₁ = [(n ₂ ) ² × _ng / n ₃ ] ^1/2
When n ₁ is obtained from this equation, n ₁ = 1.80.

In consideration of application to a glass plate for a vehicle, film formation by a sol-gel method that can be applied to a large area and is simple in terms of equipment is preferable. There is no suitable material having a refractive index near n ₁ = 1.80 in a single material that can be formed by a sol-gel method. Therefore both the sol - capable deposited by gel method, it is conceivable to apply a layer of a mixture of SiO ₂ of the TiO ₂ and n = 1.46 for n = 2.2. Further, a high refractive index layer may be formed by including ZrO _{2 with} n = 1.95, CeO ₂ , Bi ₂ O ₃ or the like.

Also, the SiO ₂ layer, which is a low refractive index material, may be formed by a sol-gel method. Furthermore, the apparent refractive index may be lowered as a porous film. Further, the refractive index may be lowered by mixing inorganic fine particles having a low refractive index. Lowering the refractive index of the second layer increases the effect of antireflection. The second layer is mainly composed of silica, but may contain B ₂ O ₃ or Al ₂ O ₃ .

In this two-layer antireflection film, the first layer has a refractive index (n ₁ ) of 1.65 to 2.20 and a film thickness (d ₁ ) of 110 to 150 nm, and the second layer has a refractive index (n ₂ ) is preferably 1.37 to 1.49, and the film thickness (d ₂ ) is preferably 81 to 100 nm. Further, the refractive index (n ₁ ) of the first layer is preferably 1.67 to 1.8, and the refractive index (n ₂ ) of the second layer is more preferably 1.40 to 1.47.

  In addition, the structure of an antireflection film is not limited to this, For example, the film | membrane of Unexamined-Japanese-Patent No. 2005-256042 can also be used.

<4-3>
In the laminated glass shown in FIG. 15B, an intermediate film is not provided in the passage region, but some intermediate films contain infrared absorbing components, that is, IR absorbing particles. When such an IR absorbing particle is contained in the intermediate film, infrared rays are absorbed and the intermediate film generates heat. On the other hand, in the passage region where the intermediate film is not provided, heat generation does not occur, and thus there is a risk of clouding in winter. On the other hand, an anti-fogging means can be provided on at least one of the vehicle outer surface and the vehicle inner surface of the outer glass plate and / or the inner glass plate in the passage region.

  As the anti-fogging means, for example, a known anti-fogging film can be used. The antifogging film is not particularly limited as long as it exhibits the antifogging effect of the glass plate, and a known film can be used. In general, the antifogging film has a hydrophilic type in which water generated from water vapor is formed on the surface as a water film, a water absorption type that absorbs water vapor, and a water repellent type that repels water droplets generated from water vapor. The anti-fogging film can be applied. Specifically, for example, various types such as an antifogging film described in JP 2014-14802 A and JP 2001-146585 A can be used.

  In addition to the antifogging film, an antifogging film in which an antifogging functional layer is formed on a base material layer can be used as an antifogging film, and the base material layer side can be attached to a glass plate. As such an antifogging film, a known film can be used, and various films such as an antifogging film disclosed in Japanese Patent Application Laid-Open No. 2014-224213 can be used.

  Furthermore, instead of the antifogging film and the antifogging film, a heating wire can be provided to obtain an antifogging effect. When a heating wire is used, since the degree of freedom of wiring is high, it is possible to flexibly cope with a region to be defogged.

<4-4>
Moreover, the first and second embodiments described above can be combined as appropriate. For example, the glass plate of the second embodiment can be polished as in the first embodiment.

  Examples of the present invention will be described below. However, the present invention is not limited to the following examples. Hereinafter, Examples 1 to 4 and Comparative Examples 1 and 2 will be given and will be discussed.

<1. Example 1>
Two single-plate float glass plates having a thickness of 2 mm and a size of 100 × 100 mm were prepared (referred to as # 1 and # 2). It was measured by Zygo Model GPI). The evaluation range is a range of 50 × 50 mm at the center of each glass plate, and the measurement wavelength λ is 632.8 nm. The surface irregularities were determined by evaluating the fringes caused by interference between the reflected light on the reference plane and the reflected light of the light beam perpendicularly incident on the glass plate surface. The incident angle needs to be strictly perpendicular, and may be, for example, 0 ° ± 1 °.

The result is as shown in “Original Value” in Table 3. The PV (Peak to Valley) value representing the degree of unevenness is the difference between the maximum value and the minimum value of unevenness in the evaluation range, and the RMS value (Root Mean Square) is the root mean square value. In either case, the unit is λ.

By the way, FIG. 17 is a diagram in which the “original value” of the A surface of the glass plate # 1 is three-dimensionally represented. According to the figure, it can be seen that large undulation is caused by the overall spherical component and the asphalt component. The absolute value of the lens action D due to the large undulation is small. For example, taking the A surface of the glass plate # 1 as an example, the PV value is 8.330λ, and the diagonal line of the measurement range is 70.7 mm. Therefore, in the above formula (1) and formula (2), For example,
d = 8.330 × 632.8 (nm)
L = 70.7 (mm)
n = 1.52
Then, D = 4.4 mdpt. Therefore, it can be said that the lens action due to the undulation of the entire surface is approximately this level.

  However, the lens action due to irregular irregularities is much larger. Therefore, a value obtained by removing the spherical component and the asphalt component from the original value by the function of the interferometer and leaving the irregular component is the “corrected value” in Table 3. Further, FIG. 18 shows a three-dimensional representation of the correction value of the A surface of the glass plate # 1, and it can be seen that the horizontal streaks are clear. In FIG. 18, the part and direction (indicated by a white line) where the peak is the steepest are selected, and the difference in height of the wavefront along the white line is displayed in FIG. According to FIG. 19, since the height difference d = 0.5λ and the width L = 9.5 mm of the steepest peak portion (portion enclosed by a rectangle), the lens action of this portion is D = 14.6 mdpt. Great value. As described above, the data on the glass surface can be evaluated by obtaining the maximum value of the local lens action after making the “corrected value” by removing the entire spherical component and the asphalt component from the original value. it can. Table 3 shows correction values and maximum lens action values obtained by the same method on the B surface of the glass plate # 1, the A surface and the B surface of the glass plate # 2.

Next, the transmission wavefront was evaluated using the glass plate # 1 as a single plate. First, a mirror was placed perpendicular to the light beam of the interferometer, and the reflected light on the reference plane interfered with the reflected light on the mirror surface. In this state, a glass plate was placed between the reference plane and the mirror, and the irregularities of the transmitted wavefront were obtained by evaluating the disturbance of the interference fringes. The results are shown in Table 4. This evaluation corresponds to FIG. 15A of the second embodiment in which the passing region is formed only by the outer glass plate in the laminated glass. The PV value and RMS value indicating the unevenness of the transmitted wavefront are much smaller than the values of both surfaces shown in Table 3, and the “cancellation effect” described in FIG. 35 functions well.

  The “original value” and the “corrected value” of the transmitted wavefront of the glass plate # 1 are three-dimensionally shown in FIGS. 20 and 21, respectively. In FIG. 21, the portion and direction (white line) where the peak is the steepest FIG. 22 shows the wavefront height difference displayed. According to FIG. 22, since the height difference d ′ = 0.045λ and the width L = 9.52 mm of the peak portion (portion enclosed by a rectangle), the lens action of this portion is a value of D = 2.5 mdpt. became. Since the “cancellation function” on both sides of the glass plate is working, the lens action on the transmitted wavefront when both sides are combined is smaller than the lens action on each surface and is a good value of 10 mdpt or less.

<2. Comparative Example>
Next, the B surface of the glass plate # 1 and the A surface of the glass plate # 2 are opposed to each other, and a glycerin layer (refractive index: 1.473) having a thickness of about 0.2 mm is disposed between them. The plates were bonded together. That is, it corresponds to the laminated glass shown in FIG. 17, and this was used as a comparative example. However, two types were prepared, one in which the directions of the uneven stripes on each glass plate were bonded in parallel and the other in which the directions of the uneven stripes on each glass plate were perpendicular.

The laminated glass plate was placed in the middle of the reference mirror facing the interferometer, and the transmitted wavefront was measured. Table 5 shows the PV value and RMS value (original value and correction value) of the transmitted wavefront and the maximum lens action value as comparative examples. Table 5 also shows the evaluation results (the same values as in Table 2) of the A surface of glass # 1 and the B surface of glass 2 in contact with air. Since the B surface of glass # 1 and the A surface of glass # 2 are in contact with glycerin and almost no light refraction occurs, the lens action due to unevenness can be ignored.

  The three-dimensional representation of the “original value” and the “correction value” of the transmitted wavefront (parallel) in the comparative example is shown in FIGS. 23 and 24, and the streaky irregularities are clearer in the correction value. I understand that. In FIG. 24, the portion and direction (indicated by a white line) where the peak is the steepest are selected, and the wavefront height difference is displayed in FIG. According to FIG. 25, since the height difference d ′ = 0.5λ and the width L = 11.9 mm of the peak portion (portion enclosed by a rectangle), the lens action of this portion becomes a value of D = 17.9 mdpt. Become.

  In Table 5, the numerical values (PV value, RMS value, lens action) indicating the unevenness of the transmission wave front of the bonded layer are the same as the numerical value of “Each surface unevenness” in both cases (parallel) (right angle). The disturbance of the wave front due to is reflected as it is. Therefore, the maximum lens action at the time of bonding is a large numerical value exceeding 10 mdpt.

<3. Example 2>
The glass plates # 1 and # 2 bonded in Comparative Example 1 are separated, and the A side of the glass plate # 1 and the B side of the glass plate # 2 are respectively used with cerium oxide powder and urethane pad dissolved in water. Polished. The apparatus used for polishing was John Crane Inc., USA. A LapmaSter FT15 type manufactured by the company, and the polishing amount was 2 μm. The surface after polishing was evaluated with an interferometer, and the numerical values (PV value, RMS value, lens action) showing unevenness are shown in Table 6. Furthermore, the B surface of the glass plate # 1 and the A surface of the glass plate # 2 were again made to face each other and bonded together with a glycerin layer having a thickness of about 0.2 mm, which was designated as Example 2. That is, it is the same as the comparative example except that the surface in contact with air has been polished, and corresponds to the aspect of FIG. 11 of the first embodiment. However, two types were prepared, one in which the directions of the uneven stripes on each glass plate were bonded in parallel and the other in which the directions of the uneven stripes on each glass plate were perpendicular. Table 6 shows the PV value and RMS value (original value and correction value) of the transmitted wavefront and the maximum lens action value measured by the interferometer.

FIG. 26 and FIG. 27 are three-dimensional representations of the “original value” and the “corrected value” of the A surface (after polishing) of the glass plate # 1. Compared with before polishing (Table 3 and FIGS. 17 and 18), it can be seen that the PV value and the RMS value of the correction values are particularly small, and the streaky irregularities are unclear. In FIG. 27, the portion and direction (indicated by a white line) where the peak is the steepest are selected, and the wavefront height difference is displayed in FIG. According to FIG. 28, since the height difference d = 0.14λ and the width L = 13.4 mm of the peak portion (portion enclosed by a rectangle), the lens action of this portion is a value of D = 2.1 mdpt. It is much smaller than 14.6 mdpt before polishing.

  The three-dimensional representation of the “original value” and “corrected value” of the transmitted wavefront (parallel) in Example 2 is shown in FIG. 29 and FIG. 30, which is more streak than the comparative example (FIGS. 23 and 24). It can be seen that the unevenness of is unclear. In FIG. 30, the portion and direction (indicated by a white line) where the peak is the steepest are selected, and the difference in height of the wavefront is displayed in FIG. According to FIG. 31, since the height difference d ′ = 0.5λ and the width L = 20.7 mm of the peak portion (portion enclosed by a rectangle), the lens action of this portion is 10 mdpt or less, D = 5.9 mdpt. Value. Since the lens action on the surface is reduced, the lens action on the transmitted wavefront is also much smaller than before polishing (comparative example: (parallel) 17.9 mdpt, (right angle) 10.1 mdpt).

<4. Example 3>
Prepare glass plates # 3 and # 4 of the same standard as glass plates # 1 and # 2 described above, face B surface of glass plate # 3 and surface A of glass plate # 4, and the thickness between them An air layer was formed by sandwiching a spacer of about 0.3 mm. That is, Example 3 corresponding to FIG. 15B of the second embodiment was prepared. However, two types were prepared, one in which the directions of the uneven stripes on each glass plate were bonded in parallel and the other in which the directions of the uneven stripes on each glass plate were perpendicular. Table 7 shows the results of measuring the PV value, the RMS value, and the maximum lens action of the unevenness of each surface and the unevenness of the transmitted wavefront used as the laminated glass in the same manner as in Example 1.

The “original value” and “corrected value” of the transmitted wavefront (parallel) of Example 2 are three-dimensionally represented, respectively, in FIGS. 32 and 33. In FIG. 33, the portion and direction in which the peak is steepest are shown. FIG. 34 shows the wavefront height difference selected (displayed by white line). According to FIG. 34, since the height difference d ′ = 0.05λ and the width L = 5.5 mm of the peak portion (portion enclosed by a rectangle), the lens action of this portion becomes a value of D = 8.4 mdpt. became. Since the “cancellation function” is working on both surfaces of the glass plate # 3 and the glass plate # 4, the lens action on the transmitted wavefront when combined is (parallel) (right angle) in each case. It is a good value of 10 mdpt or less, which is smaller than the lens action.

<5. Example 4>
Ten single-plate float glasses having a thickness of 2 mm and a size of 300 × 300 mm were prepared, and only one side surface of each was polished using a polishing apparatus.

  The polishing apparatus has a polishing tool in which a polishing pad is attached to a flange (diameter: 120 mm) that rotates at high speed, and the polishing pad is pressed against the glass surface placed on a support table for polishing. At this time, the shaft position of the flange is not moved, and the support base on which the glass plate is placed is reciprocated in one direction. The polishing pad was a grooved product made of urethane, the pressing pressure was 9.5 kgf, and the rotation speed of the flange was 400 rpm. The support on which the glass plate was placed reciprocated at a stroke of 300 mm, and the time required for one reciprocation was 16 seconds. As an abrasive, a mixture of cerium oxide powder and water (10% by weight) was supplied to the center of the polishing pad at a rate of approximately 0.2 ml / min while stirring.

  Then, 50 glass plates were polished back and forth under the above conditions on one side of 10 glass plates. Then, two sheets were paired and aligned with the direction of the lines aligned, and the polished surface was directed outward. Then, an interlayer film having a thickness of about 2 mm was bonded between these glass plates, and this was used as the laminated glass according to Example 4.

  Comparative Example 2 was prepared for comparison with Example 4. Comparative Example 2 is a laminated glass using a glass plate of the same lot as that of Example 4, but differs in that polishing is not performed.

About the range of the center part (phi) 100mm of the laminated glass which concerns on Example 4 and the comparative example 2 which were produced as mentioned above, the transmitted wave front of perpendicular incident light was measured with the Fizeau interferometer. Table 8 shows the result of obtaining the maximum lens action after removing the spherical component and the asphalt component at this time. According to Table 8, the maximum lens effects of the five sets of laminated glasses according to Example 4 are all smaller than 10 mdpt. On the other hand, the maximum lens action of the five sets of laminated glasses according to Comparative Example 2 is a value of 10 mdpt or more.

1: Windshield 10: Window glass 2: Shooting device (information device)
11: Outer glass plate 12: Inner glass plate 13: Intermediate film 18: Through hole d: Height difference

Claims (7)

A windshield used in a vehicle capable of arranging an information device that acquires information or provides information by light irradiation and / or incidence,
Comprising a window glass having at least one glass plate;
The window glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between the two glass plates,
The window glass includes a light incident area to the information device or a light passing region irradiated from the information device,
When the absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when the light is transmitted through the window glass is 10 mdpt or more, the light is transmitted through the passage region. A windshield in which the absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated in the lens is 10 mdpt or less.   The windshield according to claim 1, wherein the outer glass surface of the outer glass and the inner surface of the inner glass plate are substantially parallel to each other. A windshield used in a vehicle capable of arranging an information device that acquires information or provides information by light irradiation and / or incidence,
With window glass,
The window glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between the two glass plates,
The absolute value of the lens action of the irregular component remaining after removing the spherical component and the asphalt component from the wavefront aberration generated when light passes through the window glass is 10 mdpt or more,
The window glass includes a light incident area to the information device or a light passing region irradiated from the information device,
A windshield in which a through hole is formed in at least the intermediate film among the intermediate film and the inner glass plate at a position corresponding to the passage region of the window glass.   The windshield according to claim 3, wherein a through-hole is formed in both the intermediate film and the inner glass plate at a position corresponding to the passage region of the window glass.   The windshield according to claim 3, wherein a through-hole is formed in the intermediate film at a position corresponding to the passage region of the window glass.   The windshield according to claim 5, wherein an antireflection film is provided on at least a part of at least one of a vehicle outer surface and a vehicle inner surface in the passage region of the inner glass plate.   The window according to claim 5, wherein in the passage region of the outer glass plate and / or the inner glass plate, at least a part of at least one of the vehicle outer surface and the vehicle inner surface is provided with an antifogging means. shield.