Windshield

Abstract

The present invention is a windshield on which at least information pertaining to an automobile is projected by light emitted from a head-up display device. The windshield is provided with: an outer glass plate; an inner glass plate that faces the outer glass plate; an intermediate film that bonds the inner glass plate and the outer glass plate; a first shield layer that is disposed at the peripheral edge of at least one of the outer glass plate and the inner glass plate; and a second shield layer which is disposed in a region on the inner side of the first shield layer, in at least one of the outer glass plate and the inner glass plate, and on which the information pertaining to the automobile is projected.

Description

Windshield

[0001] The present invention relates to a windshield onto which at least information relating to a vehicle is projected by light emitted from a head-up display device (HUD device).

[0002] Patent Document 1 discloses a windshield that projects light from an HUD device and displays various information related to a vehicle.

[0003] Special Publication No. 2014-24752

[0004] As described above, the image projected onto the windshield contains information that the driver must see, such as a speed display. However, the area of ​​the windshield where the projected image is displayed also transmits light from outside the vehicle, which can make the projected image difficult to see. The present invention has been made to solve this problem, and it is an object of the present invention to provide a windshield that can reduce the influence of light from outside the vehicle on the image projected onto the windshield by a HUD device.

[0005] Item 1. A windshield on which at least information related to a vehicle is projected by light emitted from a head-up display device, the windshield comprising: an outer glass sheet; an inner glass sheet facing the outer glass sheet; an interlayer film bonding the inner glass sheet and the outer glass sheet; a first shielding layer disposed on a peripheral edge of at least one of the outer glass sheet and the inner glass sheet; and a second shielding layer disposed on at least one of the outer glass sheet and the inner glass sheet in a region more inward than the first shielding layer, and on which the information related to the vehicle is projected.

[0006] Item 2. The windshield according to Item 1, wherein the upper end of the second shielding layer is located either below the reduced test area B specified in JIS R3212 (2021) JA.1.1.4b, or below 25 mm from the lower end of the expanded test area B specified in JIS R3212 (2021) JA.1.1.4b.

[0007] Item 3. The windshield according to Item 1, wherein the first shielding layer is disposed on at least the vehicle interior surface of the inner glass sheet, of the vehicle interior surface of the outer glass sheet or the vehicle interior surface of the inner glass sheet, and the second shielding layer is disposed at least on a surface other than the vehicle interior surface of the inner glass sheet.

[0008] Item 4. The windshield according to Item 1, wherein the first shielding layer is disposed on at least the vehicle interior surface of the inner glass sheet, of the vehicle interior surface of the outer glass sheet or the vehicle interior surface of the inner glass sheet, and the first shielding layer is disposed at least on the same plane as a surface on which the second shielding layer is disposed.

[0009] Item 5. The windshield according to Item 4, wherein the first shielding layer and the second shielding layer are connected.

[0010] Item 6. The windshield according to Item 1 or 2, wherein the second shielding layer is disposed on an interior surface of the outer glass sheet.

[0011] Item 7. The windshield according to Item 6, wherein a reflective film is disposed on the surface of the inner glass plate facing the interior of the vehicle.

[0012] Item 8. The windshield according to Item 7, wherein a difference between a refractive index of the inner glass sheet and a refractive index of the interlayer film overlapping the second shielding layer is larger than a difference between a refractive index of the interlayer film overlapping the second shielding layer and a refractive index of the second shielding layer.

[0013] Item 9. The windshield according to Item 7, wherein the reflective film covers a portion of the first shielding layer.

[0014] Item 10. The windshield according to Item 1 or 2, wherein the information relating to the vehicle includes at least one of a speedometer and an odometer.

[0015] Item 11. The windshield according to Item 1 or 2, wherein the second shielding layer is disposed on the lower side when the windshield is attached to a vehicle.

[0016] Item 12. The windshield according to Item 1 or 2, wherein the light is P-polarized.

[0017] Item 13. The windshield according to Item 12, wherein one or more layers of a reflective film are disposed on a vehicle-interior surface of the inner glass plate, and when the angle of incidence of light emitted from the head-up display device is larger than the Brewster angle at the inner glass plate, the refractive index of an outermost layer of the reflective film is smaller than the refractive index of the inner glass plate.

[0018] Item 14. The windshield according to Item 12, wherein one or more layers of a reflective film are disposed on an interior surface of the inner glass sheet, and when the angle of incidence of light emitted from the head-up display device is smaller than the Brewster angle at the inner glass sheet, the refractive index of an outermost surface layer of the reflective film is larger than the refractive index of the inner glass sheet.

[0019] Item 15. The windshield according to Item 1 or 2, further comprising an illumination area where light from a second head-up display device is irradiated and projected onto an area where the first shielding layer and the second shielding layer are not disposed and where external light passes through and enters.

[0020] Item 16. The windshield according to Item 15, wherein, on the vehicle interior side of the inner glass sheet, the reflectance of the irradiated area is lower than the reflectance of an area where the first shielding layer and the second shielding layer are provided.

[0021] Item 17. The windshield according to Item 1 or 2, wherein the second shielding layer is formed on a vehicle interior surface of the outer glass sheet or a vehicle exterior surface of the inner glass sheet, and the glossiness of the second shielding layer is lower than the glossiness of the first shielding layer.

[0022] According to the present invention, the image projected onto the windshield by the HUD device can be made less susceptible to the influence of light from outside the vehicle.

[0023] FIG. 1 is a front view of a windshield according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of FIG. 1. FIG. 3 is a cross-sectional view of laminated glass. FIG. 4 is a cross-sectional view showing the projection of an image by a HUD device. FIG. 5 is a block diagram of an image processing device. FIG. 6 is a cross-sectional view of a windshield provided with a reflective film. FIG. 7 is a graph showing the relationship between the angle of incidence and reflectance. FIG. 8 is a cross-sectional view showing the projection of an image by an AR-HUD device. FIG. 9 is a front view of a windshield onto which an image is projected by an AR-HUD device.

[0024] An embodiment of a windshield of the present invention will be described below with reference to the drawings. Fig. 1 is a plan view of the windshield, and Fig. 2 is a cross-sectional view of Fig. 1. For ease of explanation, the up-down direction in Fig. 1 will be referred to as "up-down," "vertical," and "longitudinal," and the left-right direction in Fig. 1 will be referred to as "left-right." Fig. 1 illustrates a windshield as seen from the inside of a vehicle. That is, the front side of Fig. 1 is the inside of the vehicle, and the back side of Fig. 1 is the outside of the vehicle.

[0025] 1 and 2 , the windshield 1 includes a substantially rectangular laminated glass 10 and is installed on the vehicle body in an inclined position. A first shielding layer 110 and a second shielding layer 120 that block the view from outside the vehicle are laminated on the laminated glass 10. A photographing device 2 incorporating a camera for photographing the situation outside the vehicle is attached to the first shielding layer 110 via a bracket (not shown). A photographing window 113 is provided in the first shielding layer 110 at a position corresponding to the photographing device 2, and the photographing device 2 can photograph the situation outside the vehicle through the photographing window 113.

[0026] An image processing device 3 is connected to the photographing device 2, and the photographed images acquired by the photographing device 2 are processed by this image processing device 3. The photographing device 2 and the image processing device 3 constitute an in-vehicle system 5 (see FIG. 5 ), and this in-vehicle system 5 can provide various information to passengers in accordance with the processing of the image processing device 3.

[0027] Furthermore, a head-up display device (hereinafter referred to as HUD device) 500 is provided inside the vehicle. This HUD device 500 projects information such as vehicle speed onto the windshield by projecting image light showing vehicle speed, other characters, figures, etc.

[0028] 4, which will be described later, the second shielding layer 120 is disposed in an area irradiated with light from the HUD device 500. Each component will be described below.

[0029] <1. Laminated Glass> <1-1. Glass Sheets> First, the outer glass sheet 11 and the inner glass sheet 12 will be described. The outer glass sheet 11 and the inner glass sheet 12 can be made of known glass sheets, and can also be made of heat-absorbing glass, general clear glass, green glass, dark green glass, or UV-green glass. However, these glass sheets 11 and 12 must achieve a visible light transmittance that complies with the safety standards of the country in which the automobile is used. For example, the outer glass sheet 11 can ensure the required solar absorptance, and the inner glass sheet 12 can be adjusted to have a visible light transmittance that satisfies the safety standard. Examples of clear glass, heat-absorbing glass, and soda-lime glass are shown below.

[0030] (Clear glass) SiO2: 70 to 73 mass% Al2O3: 0.6 to 2.4 mass% CaO: 7 to 12 mass% MgO: 1.0 to 4.5 mass% R2O: 13 to 15 mass% (R is an alkali metal) Total iron oxide (T-Fe2O3) converted to Fe2O3: 0.08 to 0.14 mass%

[0031] (Heat-ray absorbing glass) The composition of the heat-ray absorbing glass can be, for example, based on the composition of clear glass, such that the ratio of total iron oxide (T-Fe2O3) converted to Fe2O3 is 0.4 to 1.3 mass%, the ratio of CeO2 is 0 to 2 mass%, and the ratio of TiO2 is 0 to 0.5 mass%, and the amount of glass framework components (mainly SiO2 and Al2O3) is reduced by the amount of increase in T-Fe2O3, CeO2, and TiO2.

[0032] (Soda-lime glass) SiO2: 65 to 80 mass% Al2O3: 0 to 5 mass% CaO: 5 to 15 mass% MgO: 2 mass% or more NaO: 10 to 18 mass% K2O: 0 to 5 mass% MgO + CaO: 5 to 15 mass% Na2O + K2O: 10 to 20 mass% SO3: 0.05 to 0.3 mass% B2O3: 0 to 5 mass% Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.02 to 0.03 mass%

[0033] (Green glass) SiO2: 65 to 80 mass% Al2O3: 0 to 5 mass% CaO: 5 to 15 mass% MgO: 2 mass% or more NaO: 10 to 18 mass% K2O: 0 to 5 mass% MgO + CaO: 5 to 15 mass% Na2O + K2O: 10 to 20 mass% SO3: 0.05 to 0.3 mass% B2O3: 0 to 5 mass% Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.4 to 0.6 mass%

[0034] (Dark green glass) SiO2: 65 to 80 mass% Al2O3: 0 to 5 mass% CaO: 5 to 15 mass% MgO: 2 mass% or more NaO: 10 to 18 mass% K2O: 0 to 5 mass% MgO + CaO: 5 to 15 mass% Na2O + K2O: 10 to 20 mass% SO3: 0.05 to 0.3 mass% B2O3: 0 to 5 mass% Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.7 to 1.3 mass%

[0035] The visible light transmittance of each glass plate 11, 12 can also be adjusted. To do so, for example, the content of Fe2O3 is adjusted to color the glass plates 11, 12, thereby adjusting the visible light transmittance. For example, when the content of Fe2O3 is increased, the glass plates 11, 12 are colored green, resulting in the above-mentioned green glass or dark green glass. On the other hand, when the content of Fe2O3 is decreased, the above-mentioned clear glass is obtained.

[0036] The thickness of the laminated glass 10 according to the present embodiment is not particularly limited. However, the total thickness of the outer glass sheet 11 and the inner glass sheet 12 can be, for example, 2.1 to 6 mm. From the viewpoint of weight reduction, the total thickness of the outer glass sheet 11 and the inner glass sheet 12 is preferably 2.4 to 3.8 mm, more preferably 2.6 to 3.4 mm, and particularly preferably 2.7 to 3.2 mm.

[0037] The outer glass sheet 11 is primarily required to be durable and impact resistant against external obstacles, and as an automobile windshield, it must be impact resistant against flying objects such as pebbles. On the other hand, a larger thickness is undesirable because it increases the weight. From this perspective, the thickness of the outer glass sheet 11 is preferably 1.8 to 2.3 mm, and more preferably 1.9 to 2.1 mm. The thickness to be adopted can be determined depending on the application of the glass.

[0038] The thickness of the inner glass sheet 12 can be the same as that of the outer glass sheet 11, but can be thinner than the outer glass sheet 11, for example, to reduce the weight of the laminated glass 10. Specifically, taking into account the strength of the glass, the thickness 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. Furthermore, the thickness of 0.8 to 1.3 mm is more preferable. The thickness of each of the glass sheets 11, 12 will be described later.

[0039] Furthermore, as will be described in detail later, this laminated glass 10 is curved so as to be convex toward the exterior of the vehicle. In this case, the thickness is measured at two locations, one above and one below a center line extending vertically through the center of the laminated glass 10 in the left-right direction. The measuring device is not particularly limited, but for example, a thickness gauge such as the SM-112 manufactured by Teclock Corporation can be used. During measurement, the curved surface of the laminated glass 10 is placed on a flat surface, and the edge of the laminated glass 10 is clamped between the thickness gauges to perform the measurement.

[0040] <1-2. Interlayer Film> Fig. 3 shows an example of the interlayer film. As shown in Fig. 3, the interlayer film 13 can be configured as three layers, with a soft core layer 136 sandwiched between a pair of harder outer layers 137 and 138. However, the configuration is not limited to this, and the interlayer film 13 may be formed of multiple layers including the core layer 136 and at least one outer layer disposed on the outer glass sheet 11 side.

[0041] The hardness of the core layer 136 is not particularly limited as long as it is softer than the outer layers 137 and 138. The materials constituting each of the layers 136-138 are not particularly limited, but can be selected based on, for example, Young's modulus. Specifically, the Young's modulus of the core layer 136 is preferably 1 to 20 MPa, more preferably 1 to 18 MPa, and particularly preferably 1 to 14 MPa, at a frequency of 100 Hz and a temperature of 20°C. Setting the Young's modulus in this range can prevent a decrease in sound transmission loss (STL) in the low frequency range of approximately 3500 Hz or less. On the other hand, the Young's modulus of the outer layers 137 and 138 is preferably high to improve sound insulation performance in the high frequency range, and can be 560 MPa or more, 600 MPa or more, 650 MPa or more, 700 MPa or more, 750 MPa or more, 880 MPa or more, or 1300 MPa or more at a frequency of 100 Hz and a temperature of 20°C. The upper limit of the Young's modulus of the outer layer 522 is not particularly limited, but can be set, for example, from the viewpoint of processability. For example, it is known empirically that if the Young's modulus is 1750 MPa or more, processability, particularly cutting, becomes difficult.

[0042] As a specific material, the outer layers 137, 138 can be made of, for example, polyvinyl butyral resin (PVB). Polyvinyl butyral resin is preferable because it has excellent adhesion to the outer glass plate 11 and excellent penetration resistance. On the other hand, the core layer 136 can be made of, for example, ethylene vinyl acetate resin (EVA) or polyvinyl acetal resin, which is softer than the polyvinyl butyral resin that makes up the outer layers. By sandwiching a soft core layer between the two layers, sound insulation performance can be significantly improved while maintaining the same adhesion and penetration resistance as a single-layer resin interlayer.

[0043] The thickness of the core layer 136 is not particularly limited, but 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 of the outer layers 137 and 138 is not particularly limited, but is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 1.0 mm.

[0044] However, the above-mentioned intermediate film 13 is only an example, and it may be formed as a single layer, or may include various functional layers such as a heat reflecting film, an ultraviolet absorbing film, etc.

[0045] 2. First Shielding Layer Next, the first shielding layer 110 will be described. As illustrated in FIGS. 1 and 2 , in this embodiment, the first shielding layer 110 is formed along the peripheral edge of the laminated glass 10 on the interior side of the outer glass sheet 11 and on the interior side of the inner glass sheet 12. Specifically, as shown in FIG. 1 , the first shielding layer 110 can be divided into a peripheral region 111 that follows the peripheral edge of the laminated glass 10 and a protruding region 112 that protrudes downward in a rectangular shape from the upper edge of the laminated glass 10. The peripheral region 111 blocks light from entering through the peripheral edge of the windshield. On the other hand, the protruding region 112 prevents the imaging device 2 placed inside the vehicle from being seen from outside the vehicle.

[0046] However, if the first shielding layer 110 blocks the imaging range of the imaging device 2, it will be impossible for the imaging device 2 to capture images of the situation ahead outside the vehicle. Therefore, in this embodiment, a rectangular imaging window 113 is provided in the protruding region 112 of the first shielding layer 110 at a position corresponding to the imaging device 2 so that the imaging device 2 can capture images of the situation outside the vehicle.

[0047] The first shielding layer 110 may be laminated on at least one of the inner surface of the outer glass sheet 11 and the outer surface of the inner glass sheet 12 .

[0048] Next, a description will be given of the material of the first shielding layer 110. The material of the first shielding layer 110 may be appropriately selected depending on the embodiment as long as it can block the view from outside the vehicle, and for example, a dark-colored ceramic such as black, brown, gray, or dark blue may be used.

[0049] If black ceramic is selected as the material for the first shielding layer 110, for example, the black ceramic is laminated on the peripheral portion of the interior surface of the inner glass sheet 12 by screen printing or the like, and the laminated ceramic is then heated together with the outer glass sheet 11 and the inner glass sheet 12. This allows the first shielding layer 110 to be formed on the peripheral portions of the outer glass sheet 11 and the inner glass sheet 12. Furthermore, when printing the black ceramic, a region is left where the black ceramic is not printed. This allows the imaging window 113 to be formed. Note that various materials can be used as the ceramic for the first shielding layer 110. For example, ceramics having the compositions shown in Table 1 below can be used for the first shielding layer 110.

[0050] *1, Main components: copper oxide, chromium oxide, iron oxide and manganese oxide *2, Main components: bismuth borosilicate, zinc borosilicate

[0051] 3. Second Shielding Layer The second shielding layer 120 is disposed in an area irradiated with light from the HUD device 500. Specifically, as shown in FIG. 4 , the second shielding layer 120 is disposed on the interior surface of the outer glass plate 11. The HUD device 500 is disposed inside or on top of the dashboard of the vehicle, irradiates light toward the second shielding layer 120, and projects information about the vehicle onto the windshield. The information about the vehicle may be various information such as a speedometer or odometer as defined in Article 46 of the Road Transport Vehicle Safety Standards, as well as information such as a tachometer, fuel gauge, water gauge, and warning lights. Note that while FIG. 4 illustrates the light from the HUD device 500 as being reflected only by the interior surface of the inner glass plate 12, in reality, the light is also reflected by the exterior surface of the inner glass plate 12 and the interior surface of the second shielding layer 120, as described below.

[0052] In particular, the speedometer or odometer stipulated in Article 46 of the Vehicle Safety Standards must be easily visible to the driver. If light from outside the vehicle overlaps with light from the HUD device 500, the light may be affected by changes in the brightness of the external environment, making it difficult for the driver to easily see the image from the HUD device 500. For these reasons, the second shielding layer 120 is required to block visible light from outside. Furthermore, by reducing at least one of the ultraviolet transmittance (ISO 9050) and solar transmittance (JIS R 3106) of the second shielding layer 120, it is possible to prevent the flat light source of the HUD device 500 from deteriorating due to ultraviolet light or heat entering the vehicle interior from outside the vehicle through the second shielding layer 120.

[0053] When an image of light emitted from the HUD device 500 (hereinafter referred to as the HUD image) is projected onto an area through which external light passes, the light reflected from the HUD image projected onto the windshield overlaps with the external light. Therefore, to improve the visibility of the HUD image, the intensity of the emitted light must be stronger than the external light. Continuing to irradiate the same area of ​​the windshield with such strong light may cause discoloration of the windshield. Therefore, it is desirable to project information (HUD image) that will be displayed in the same area for a long period of time onto the second shielding layer 120. In particular, when projecting the HUD image onto the second shielding layer 120, there is no need to consider external light, so illuminance can be reduced. As a result, discoloration of the windshield can be suppressed.

[0054] The second shielding layer 120 can also be formed of the same material as the first shielding layer 110. Furthermore, like the first shielding layer 110, the second shielding layer 120 can be laminated on at least one of the interior surface of the outer glass plate 11, the exterior surface of the inner glass plate 12, and the interior surface of the inner glass plate 12.

[0055] The second shielding layer 120 is positioned in the left-right direction in front of the driver on the windshield. For example, in a right-hand drive vehicle, it is positioned on the right side of the windshield as seen from the driver's perspective. The second shielding layer 120 is positioned in the up-down direction, for example, at a position lower than (i) or (ii) below, so as not to obstruct the driver's forward field of view. (i) Lower than the lower end of the "reduced test area B" specified in JIS R3212 (2021) JA. 1.1.4b. (ii) Lower than a position 25 mm from the lower end of the "expanded test area B" specified in JIS R3212 (2021) JA. 1.1.4b.

[0056] That is, the second shielding layer 120 is provided at the bottom of the windshield.

[0057] The shape of the second shielding layer 120 is not particularly limited, but may be any shape that allows easy display of information, and may be various shapes such as rectangular, polygonal, circular, elliptical, or irregular shapes.

[0058] 4. In-Vehicle System Next, an in-vehicle system 5 including an image capturing device 2 and an image processing device 3 will be described with reference to Fig. 5. Fig. 5 illustrates an example of the configuration of the in-vehicle system 5. As shown in Fig. 5, the in-vehicle system 5 according to this embodiment includes the image capturing device 2 and the image processing device 3 connected to the image capturing device 2.

[0059] The image processing device 3 is a device that processes the captured images acquired by the imaging device 2. The image processing device 3 has, for example, general hardware such as a storage unit 31, a control unit 32, and an input / output unit 33 connected via a bus as a hardware configuration. However, the hardware configuration of the image processing device 3 is not limited to this example, and components can be added, omitted, or added as appropriate to the specific hardware configuration of the image processing device 3 depending on the embodiment.

[0060] The storage unit 31 stores various data and programs (not shown) used in the processes executed by the control unit 32. 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 also be acquired from a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). Furthermore, the storage unit 31 may also be called an auxiliary storage device.

[0061] As described above, the laminated glass 10 is disposed at an angle relative to the vertical direction and is curved. The image capturing device 2 captures an image of the situation outside the vehicle through the laminated glass 10. Therefore, the captured image captured by the image capturing device 2 is deformed depending on the orientation, shape, refractive index, optical defects, etc. of the laminated glass 10. In addition, aberration inherent to the camera lens of the image capturing device 2 is also added. Therefore, the memory unit 31 may store correction data for correcting the image deformed by the aberration of the laminated glass 10 and the camera lens.

[0062] The control unit 32 has 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, etc.) used for processing by the processor. The ROM, RAM, etc. may be called main memory devices in the sense that they are arranged in the address space handled by the processor in the control unit 32. The control unit 32 functions as an image processing unit 321 by executing various data and programs stored in the memory unit 31.

[0063] The image processing unit 321 processes the captured image acquired by the image capturing device 2. The processing of the captured image can be selected as appropriate depending on the embodiment. For example, the image processing unit 321 may recognize a subject appearing in the captured image by analyzing the captured image using pattern matching or the like. In this embodiment, since the image capturing device 2 captures an image of the situation ahead of the vehicle, the image processing unit 321 may further determine whether a living thing, such as a human, is present in front of the vehicle based on the subject recognition. If a person is present in front of the vehicle, the image processing unit 321 may output a warning message using a predetermined method.

[0064] The input / output unit 33 is one or more interfaces for transmitting and receiving data to and from devices external to the image processing device 3 .

[0065] Such image processing device 3 may be a device designed specifically for the service to be provided, or may be a general-purpose device such as a PC (Personal Computer) or a tablet terminal.

[0066] 5. Features The windshield configured as described above can achieve the following effects: (1) Because the second shielding layer 120 is arranged so as to overlap the projection area of ​​the HUD device 500, light from outside the vehicle can be blocked by the second shielding layer 120, thereby preventing the information from the HUD device 500 projected onto the windshield from becoming difficult to see due to light from outside the vehicle. In other words, the projected information can be made more visible regardless of the brightness outside the vehicle.

[0067] In particular, when speed indications and the like stipulated in Article 46 of the Vehicle Safety Standards are displayed on an instrument panel as in the past, the driver is required to visually confirm the speed indication by at least one of a large shift in line of sight and a change in focal length, which can easily cause eye strain, etc. Therefore, by using the HUD device 500 to display the speed indication and the like on the windshield, eye strain can be reduced.

[0068] The information provided by external light passing through the lower part of the windshield is information about a position where the distance to the hood or an object is short, and the focal length is short. On the other hand, the information provided by external light passing through the upper part of the windshield may have a long focal length. Therefore, for example, if the second shielding layer 120 is provided at the upper part of the windshield, the focal length may differ from the information obtained from external light, which may cause eye strain. Therefore, it is desirable to place the second shielding layer 120 at the lower part of the windshield, as in this embodiment.

[0069] (2) Because the surface of the second shielding layer 120 may be uneven, for example, if the second shielding layer 120 is disposed on the interior surface of the inner glass plate 12, the light from the HUD device 500 is hardly able to pass through the second shielding layer 120 and is reflected only by the second shielding layer 120. This may cause the image of the light from the HUD device 500 to fluctuate. Therefore, in this embodiment, the second shielding layer 120 is disposed on the interior surface of the outer glass plate 11 (it may be disposed on a surface other than the interior surface of the inner glass plate 12). This eliminates the influence of the unevenness on the surface of the second shielding layer 120 and prevents image fluctuating. However, the second shielding layer 120 may also be disposed on the interior surface of the inner glass plate.

[0070] (3) The light from the HUD device 500 can be P-polarized. This allows the driver to see the information projected onto the windshield even when wearing polarized sunglasses.

[0071] Article 46 of the Vehicle Safety Standards stipulates that the speedometer or odometer must be easily visible regardless of whether the driver is wearing polarized sunglasses, so it is desirable to make the information about the vehicle projected on the windshield visible. Therefore, it is desirable that the light from the HUD device 500 be P-polarized. For example, if an instrument panel is not provided and information such as a speed display is projected only on the windshield by the HUD device 500, the light from the HUD device 500 must be P-polarized.

[0072] 6. Modifications Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. Note that the following modifications can be combined as appropriate.

[0073] <6-1> As described in the above embodiment, when the second shielding layer 120 is disposed on the interior surface of the outer glass plate 11, the light from the HUD device 500 is reflected by the interior surface of the inner glass plate 12, the exterior surface of the inner glass plate 12 (the interior surface of the interlayer 13), and the interior surface of the second shielding layer 120. Therefore, these reflected lights may cause a discrepancy in the projected information (occurrence of a discrepancy in the reflected image). Therefore, in order to suppress such a discrepancy, the following measures can be taken.

[0074] (1) As shown in FIG. 6 , a transparent reflective film 7 is provided on the interior surface of the inner glass plate 12. This reduces the amount of light transmitted through the inner glass plate 12, thereby reducing reflections on the interior surface of the inner glass plate 12 and the interior surface of the second shielding layer 120. As a result, it is possible to prevent the deviation of the reflected image from becoming apparent. Furthermore, when the light from the HUD device 500 is P-polarized light, the reflectivity of P-polarized light is lower than that of S-polarized light, so sufficient reflectivity cannot be obtained on the windshield. Therefore, providing the reflective film 7 is useful. A known reflective film 7 can be used. Furthermore, the reflective film 7 may be composed of a single layer or multiple layers.

[0075] (2) The difference between the refractive index of the inner glass plate 12 and the refractive index of the intermediate film 13 overlapping the second shielding layer 120 can be made larger than the difference between the refractive index of the intermediate film 13 overlapping the second shielding layer 120 and the refractive index of the second shielding layer 120.

[0076] This allows the reflection of light on the vehicle interior surface of the interlayer 13 to be greater than the reflection of light on the vehicle interior surface of the second shielding layer 120. As a result, the reflection of light on the vehicle interior surface of the interlayer 13 is reduced, thereby reducing the deviation of the reflected image.

[0077] (3) When the angle of incidence of light irradiated from the HUD device 500 onto the reflective film 7, which consists of at least one layer, is larger than the Brewster angle at the interface between the inner glass plate 12 and the atmosphere, the reflectance at the outermost layer of the reflective film 7 can be increased by making the refractive index of the outermost layer of the reflective film 7 that comes into contact with the atmosphere smaller than the refractive index of the inner glass plate 12. Conversely, when the angle of incidence of light irradiated from the HUD device 500 onto the reflective film 7, which consists of at least one layer, is smaller than the Brewster angle at the interface between the inner glass plate 12 and the atmosphere, the reflectance at the outermost layer of the reflective film 7 can be increased by making the refractive index of the outermost layer of the reflective film 7 that comes into contact with the atmosphere larger than the refractive index of the inner glass plate 12.

[0078] When the reflective film 7 is composed of multiple layers, its reflectance is the sum of the values ​​calculated at each interface by multiplying the transmittance of light incident at each interface by the reflectance at that interface. If the reflectance at the outermost surface can be increased, less light will be incident on the next interface, and therefore, for the same reflectance, less light will be reflected at that interface. Therefore, by increasing the reflectance at the outermost surface, reflection can be strengthened even with the same number of layers, making the reflected image easier to see. Note that, when considering the Brewster angle, the relationship between the angle of incidence at the outermost surface layer and the reflectance at the outermost surface layer is as shown in Figure 7.

[0079] <6-2> A second HUD device can be used in the windshield, which projects light onto an area through which external light passes. The second HUD device can display information that does not need to be displayed superimposed on objects in the external scene, as well as information that needs to be displayed superimposed on objects in the external scene. Examples of information that does not need to be displayed superimposed on objects in the external scene include information indicating the vehicle's status, such as a fuel gauge, a water temperature gauge, turn signals, headlights, whether the doors are open or closed, the operation status of ADAS functions, and warning lights, information about the vehicle's surroundings, such as a backup monitor, a compass, a map, car navigation information, such as the distance to the destination and the estimated time of arrival, and audio information, such as the operation of the audio system and the music being played.

[0080] On the other hand, information that needs to be displayed superimposed on objects in the external scene includes, for example, navigation information such as the location of corners to turn and lane change instructions, and information about objects that require attention, such as pedestrians, bicycles, and motorcycles. To display such information, a HUD device with an AR function (referred to as an AR-HUD device) can be used. As shown in FIG. 8 , the AR-HUD device 600 not only projects an image onto the windshield as described above, but also displays a second image 52 on the windshield as a virtual image. For ease of explanation, the image formed by light from the normal HUD device 500 will be referred to as a first image 51, and the image formed by light from the AR-HUD device 600 will be referred to as a second image 52. The second image 52 is an image for AR (Augmented Reality) display, and is displayed so as to be superimposed on objects included in the external scene. The objects are included in the external scene visible through the laminated glass 10, such as roads, buildings, pedestrians, vehicles ahead, and road signs. The second image 52 is a graphic or character such as an arrow as shown in FIG. 9 , and in this example, is displayed so as to be superimposed on the road in the external scene. That is, the first image 51 is displayed so as to be focused on an object located approximately 3 m or more away from the driver's eyes. The first image 51 can move as seen by the driver, tracking the object so as to be fixed relative to the object. Therefore, the relative positional relationship between the driver's eyes, a specific object in the external scene, and the first image 51 is continuously maintained. Therefore, the shape of the first image 51 may be continuously updated at a predetermined interval to match the relative position and shape of the specific object. The area of ​​the laminated glass 10 onto which the first image 51 is projected is different from the first shielding layer 110 and the second shielding layer 120 described above.

[0081] In this case, the reflectance of the area where the first image 51 is displayed can be made greater than the reflectance of the area where the second image 52 is displayed. This is because the second image 52 is displayed by being superimposed on transmitted light (external view) from outside the vehicle, and if the reflection of the interior of the vehicle becomes large due to reflection, the second image becomes difficult to see. On the other hand, the first image 51 is displayed at a position corresponding to the second shielding layer 120, and is therefore less affected by reflection.

[0082] <6-3> When the first shielding layer 110 arranged around the periphery of the windshield is arranged on the interior surface of the inner glass plate 12, applying an adhesive or the like to the first shielding layer 110 makes it easier to attach the windshield to the vehicle body. From this perspective, it is preferable that the first shielding layer 110 be arranged at least on the interior surface of the inner glass plate 12. In this case, applying the above-mentioned reflective film 7 on the first shielding layer 110 may reduce the adhesive strength with the vehicle body, so it is preferable that the reflective film 7 be arranged in a location where the first shielding layer 110 is not provided (or in a portion of the first shielding layer 110). In particular, if a reflective film having a film substrate and a reflective film 7 formed on this film substrate is used and the film substrate is attached to the first shielding layer 110 with a transparent adhesive layer, there is a concern that the adhesive strength between the windshield and the vehicle body may be reduced.

[0083] <6-4> When the first shielding layer 110 and the second shielding layer 120 are disposed on the same surface of either of the glass plates 11 and 12, they may be connected to each other. This allows the first shielding layer 110 and the second shielding layer 120 to be formed by a single printing process.

[0084] <6-5> It is also possible to adjust the glossiness instead of the reflectance. That is, the second shielding layer 120 can be formed on the vehicle interior surface of the outer glass plate 11 or the vehicle exterior surface of the inner glass plate 12, and the glossiness of the second shielding layer 120 can be made lower than the glossiness of the first shielding layer 110. For example, even if the first shielding layer 110 and the second shielding layer 120 are on the same surface of either of the glass plates 11, 12, the glossiness can be made different as described above.

[0085] If the glossiness of the second shielding layer 120 is lower than that of the first shielding layer 110, diffuse reflection increases, and by strengthening the reflection of the second shielding layer 120 relatively to the reflection of the first shielding layer 110, double images can be suppressed. In particular, it is preferable to place the second shielding layer 120 on the vehicle interior side of the inner glass plate 12, as this strengthens the reflection at the outermost surface of the vehicle interior side of the windshield. Furthermore, when the shielding layers 110, 120 are formed from ceramics, the glossiness can be improved by increasing the firing temperature. In other words, the glossiness can be controlled by adjusting the temperature distribution during firing. Furthermore, the glossiness can be reduced by using a ceramic material with a high melting point.

[0086] REFERENCE SIGNS LIST 10 Laminated glass 11 Outer glass sheet 12 Inner glass sheet 13 Interlayer 110 First shielding layer 120 Second shielding layer

Claims

1. A windshield on which at least information relating to the vehicle is projected by light irradiated from a head-up display device arranged on the inside of the vehicle, comprising: an outer glass plate; an inner glass plate facing the outer glass plate; an intermediate film bonding the inner glass plate and the outer glass plate; a first shielding layer arranged on the peripheral portion of at least one of the outer glass plate and the inner glass plate; and a second shielding layer arranged on at least one of the outer glass plate and the inner glass plate, in an area more inside than the first shielding layer, and on which information relating to the vehicle is projected.

2. The upper end of the second shielding layer is JIS R3212 (2021) J A. Below the reduced test area B specified in 1.1.4b, or JIS R3212 (2021) J A. The windshield of claim 1, which is located at any one of the following locations: A. More than 25 mm below the lower end of the expanded test area B as defined in 1.1.4b.

3. A windshield as described in claim 1, wherein the first shielding layer is disposed on at least the vehicle interior surface of the inner glass sheet, of the vehicle interior surface of the outer glass sheet or the vehicle interior surface of the inner glass sheet, and the second shielding layer is disposed at least on a surface other than the vehicle interior surface of the inner glass sheet.

4. A windshield as described in claim 1, wherein the first shielding layer is disposed on at least the vehicle interior side of the inner glass sheet, of the vehicle interior side of the outer glass sheet or the vehicle interior side of the inner glass sheet, and the first shielding layer is disposed at least on the same plane as the surface on which the second shielding layer is disposed.

5. The windshield of claim 1, wherein the first shielding layer and the second shielding layer are connected.

6. A windshield as described in claim 1 or 2, wherein the second shielding layer is disposed on the interior side of the outer glass sheet.

7. The windshield according to claim 6, wherein a reflective film is disposed on the surface of the inner glass sheet facing the interior of the vehicle.

8. A windshield as described in claim 7, wherein the difference between the refractive index of the inner glass sheet and the refractive index of the intermediate film overlapping with the second shielding layer is greater than the difference between the refractive index of the intermediate film overlapping with the second shielding layer and the refractive index of the second shielding layer.

9. The windshield according to claim 7, wherein the reflective film covers at least a portion of the second shielding layer.

10. The windshield of claim 1 or 2, wherein the information relating to the vehicle includes at least one of a speedometer or an odometer.

11. A windshield as described in claim 1 or 2, wherein the second shielding layer is positioned on the lower side when the windshield is installed on a vehicle.

12. The windshield of claim 1 or 2, wherein the light is P-polarized.

13. A windshield as described in claim 12, wherein one or more layers of reflective film are disposed on the vehicle interior surface of the inner glass plate, and when the angle of incidence of light irradiated from the head-up display device is larger than the Brewster's angle at the inner glass plate, the refractive index of the outermost layer of the reflective film is smaller than the refractive index of the inner glass plate.

14. A windshield as described in claim 12, wherein one or more layers of reflective film are disposed on the vehicle interior surface of the inner glass plate, and when the angle of incidence of light irradiated from the head-up display device is smaller than the Brewster's angle at the inner glass plate, the refractive index of the outermost layer of the reflective film is larger than the refractive index of the inner glass plate.

15. A windshield as described in claim 1 or 2, further comprising an illumination area into which light from a second head-up display device is irradiated and projected onto an area where external light is transmitted and incident and where the first shielding layer and the second shielding layer are not disposed.

16. The windshield according to claim 15, wherein on the vehicle interior side of the inner glass sheet, the reflectance of the irradiated area is smaller than the reflectance of an area where the first shielding layer and the second shielding layer are provided.

17. A windshield as described in claim 1 or 2, wherein the second shielding layer is formed on the interior side of the outer glass plate or the exterior side of the inner glass plate, and the glossiness of the second shielding layer is lower than the glossiness of the first shielding layer.

Images