Windshield

Abstract

The present invention provides a windshield having an ARHUD region for displaying a first image irradiated from a head-up display device on an exterior scene seen from outside of a vehicle, the windshield comprising a plate-shaped glass member having the ARHUD region, and when X1 is the longitudinal slope difference in the ARHUD region, X1 is the longitudinal slope difference in the ARHUD region, X2 is the longitudinal slope difference in the ARHUD region, X3 is the longitudinal slope difference in the ARHUD region, X2 is the longitudinal slope difference in the ARHUD region, and X3 is the longitudinal slope difference in the ARHUD region. The following condition is satisfied: X1 < 0.0008 (rad / mm), in the ARHUD region, m points Aij (1 < = i < = m, 1 < = j < = n) in the horizontal direction and n points Aij (1 < = i < = m, 1 < = j < = n) arranged in a lattice in the vertical direction are defined, and the inclination angle between the points Aij and Ai (j + 1) (where 1 < = i < = m, 1 < = j < = n-1) adjacent to each other in the vertical direction is set as [theta] Aij (rad). X1 is a value obtained by dividing the difference between two points of any [theta] Aij and [theta] Aij other than [theta] Aij (excluding points located at the same horizontal direction) by the distance in the vertical direction between the two points.

Description

Technical Field

[0001] The present invention relates to a windshield. Background Art

[0002] Head-up displays (HUDs) have been proposed that project information such as vehicle speed onto a vehicle's windshield by illuminating it with image light. These HUDs allow drivers to check vehicle speed by viewing the information projected onto the windshield, rather than onboard instruments like the speedometer. This eliminates the need to significantly shift their gaze forward while driving. This has the advantage of improving driving safety.

[0003] In recent years, a technology has been proposed that superimposes images generated by the image light emitted from the HUD device on the scenery outside the vehicle. This technology uses augmented reality (AR) technology to superimpose images such as arrows on roads and buildings in the scenery, thereby facilitating navigation.

[0004] For example, Patent Document 1 proposes a technique for correcting positional deviations of an augmented reality image (hereinafter referred to as an AR image) in accordance with changes in the posture of a vehicle caused by changes in vehicle speed.

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 2021-104803 Summary of the Invention

[0006] Technical problem to be solved by the invention However, as mentioned above, there are limits to correcting the positional offset of the AR image in response to changes in vehicle speed. Even with corrections, it is difficult to eliminate the positional offset if the windshield is deformed, for example. For example, if the windshield is deformed, not only will positional offset occur, but the AR image itself may also be distorted.

[0007] The present invention has been made to solve the above-mentioned technical problems, and an object of the present invention is to provide a windshield capable of suppressing deformation of an AR image.

[0008] Technical solutions to technical problems Item 1. A windshield having an ARHUD area for displaying a first image emitted from a head-up display device superimposed on a scene viewed from outside the vehicle. The windshield includes a plate-shaped glass member having the ARHUD area. In the ARHUD region, the slope of the surface shape of the glass member is defined, and when the longitudinal difference is defined as X1, the following conditions are satisfied: X1<0.0008(rad / mm) In the ARHUD area, m points in the horizontal direction and n points in the vertical direction are arranged in a grid pattern, with a total of m×n points Aij (1≤i≤m, 1≤j≤n). On the surface of the glass member on the vehicle interior side, the inclination angle between the vertically adjacent points Aij and Ai(j+1) (where 1≤i≤m, 1≤j≤n-1) is θAij (rad) as the slope. X1 is a value obtained by dividing the difference between an arbitrary θAij and another θAij (excluding points at the same horizontal position) by the vertical distance between the two points.

[0009] Item 2. The windshield according to Item 1, wherein, within the ARHUD region, when the lateral difference in the slope is defined as Y1, the following conditions are satisfied: Y1<0.0003(rad / mm) Here, Y1 is a value obtained by dividing the difference between any two points, θA11 and another θAij (excluding points at the same vertical position), by the horizontal distance between the two points.

[0010] Item 3. The windshield according to Item 1 or 2, wherein, when the longitudinal difference in the slope of the outer region excluding the ARHUD region is defined as X2 and the lateral difference in the slope is defined as Y2, at least one of the following equations is satisfied: X1<X2 Y1<Y2 In the outer region, m points in the horizontal direction and n points in the vertical direction are arranged in a grid pattern, totaling m×n points Bij (1≤i≤m, 1≤j≤n). On the surface of the glass member on the vehicle interior side, let the inclination angle between the vertically adjacent points Bij and Bi,j+1 (where 1≤i≤m, 1≤j≤n-1) be θBij (rad), X2 is the value obtained by dividing the difference between any θBij and another θBij (excluding points at the same horizontal position) by the vertical distance between the two points. Y2 is a value obtained by dividing the difference between an arbitrary θBij and another θBij (excluding points at the same vertical position) by the horizontal distance between the two points.

[0011] Item 4. The windshield according to Item 3, wherein: 0.0008(rad / mm)<X2<0.0015(rad / mm); and 0.0003 (rad / mm)<Y2<0.0010 (rad / mm).

[0012] Item 5. The windshield according to any one of Items 1 to 4, wherein the glass component comprises: inner glass panel; an outer glass plate disposed opposite to the inner glass plate; and An intermediate film is provided to bond the inner glass plate and the outer glass plate together.

[0013] Item 6. The windshield according to Item 3, wherein a second image emitted from the head-up display device is displayed in the outer area.

[0014] Item 7. The windshield according to any one of Items 1 to 6, wherein the points Aij are defined at a pitch of 20 mm or less in the ARHUD region. When the wedge angles at the above-mentioned points Aij are measured on the vehicle interior side surface of the above-mentioned glass component using an interferometer (where m and n are each set to be greater than 240), the difference between the maximum and minimum values ​​of the wedge angles is within 0.32 mrad.

[0015] Item 8. The windshield according to any one of Items 1 to 7, wherein the first image is formed at a distance of 3 meters or more from the driver.

[0016] Item 9. The windshield according to any one of Items 1 to 8, wherein the ARHUD region has an area of ​​50 mm×50 mm or more.

[0017] Item 10. The windshield according to any one of Items 1 to 9, wherein the first image is at least one of text and graphics. The first image is configured to overlap with at least one of a building, a road, a pedestrian, and a transport machine included in the outside scene.

[0018] Item 11. The windshield according to any one of Items 1 to 10, wherein the height of the first image displayed on the glass member changes.

[0019] Effects of the Invention The present invention can suppress deformation of AR images. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a plan view showing an embodiment in which the laminated glass for an automobile according to the present invention is applied to a windshield.

[0021] Figure 2 yes Figure 1 Cross-sectional view of .

[0022] Figure 3 It is a cross-sectional view of the interlayer.

[0023] Figure 4 is an example of a block diagram of an in-vehicle system.

[0024] Figure 5 This is a cross-sectional view illustrating display of a first image using the HUD device.

[0025] Figure 6 This is a front view for explaining how the first image and the second image are displayed using the HUD device.

[0026] Figure 7 This is a diagram illustrating the arrangement of grid points within the ARHUD area.

[0027] Figure 8 It means along Figure 7 A diagram showing the cross-sectional shape of the surface of the inner glass plate on the vehicle inner side taken along an arbitrary vertical line.

[0028] Figure 9 This is a diagram illustrating the inclination angle between adjacent points Aij and Aij+1.

[0029] Figure 10 It means along Figure 7 A diagram showing the cross-sectional shape of the surface of the inner glass plate on the vehicle interior side taken along the perpendicular lines L2 and L3.

[0030] Figure 11 This is a diagram illustrating the deformation of Sample 1.

[0031] Figure 12 This is a diagram illustrating the deformation of Sample 1. DETAILED DESCRIPTION

[0032] Hereinafter, one embodiment of the windshield according to the present invention will be described with reference to the drawings. Figure 1 This is a top view of the windshield. Figure 2 yes Figure 1 For the sake of convenience, Figure 1 The up and down directions are called "up and down", "vertical", and "longitudinal". Figure 1 The left and right directions are called "left and right". Figure 1The windshield as seen from the inside of the car is shown as an example. Figure 1 The front side of the paper is the outside of the car. Figure 1 The inside of the paper is the inside of the car.

[0033] like Figure 1 and Figure 2 As shown, the windshield 1 comprises a generally rectangular laminated glass 10, which is tilted relative to the vehicle body. Furthermore, a shielding layer 110 is laminated on the inner surface of the laminated glass 10, which faces the vehicle interior, to block the view from outside the vehicle. Furthermore, a camera 2, which includes a built-in camera for capturing images of conditions outside the vehicle, is mounted on the shielding layer 110 via a bracket (not shown). A capturing window 113 is provided on the shielding layer 110 at a position corresponding to the camera 2, allowing the camera 2 to capture images of conditions outside the vehicle.

[0034] The image processing device 3 is connected to the imaging device 2, and the image captured by the imaging device 2 is processed by the image processing device 3. The imaging device 2 and the image processing device 3 constitute the vehicle-mounted system 5 (see Figure 4 ), the vehicle-mounted system 5 can provide various information to passengers based on the processing of the image processing device 3.

[0035] Furthermore, a head-up display device (hereinafter referred to as HUD device) 500 is installed in the vehicle. This HUD device 500 projects information such as vehicle speed onto the windshield by emitting image light of vehicle speed, other text, graphics, etc. Below, each component is described.

[0036] <1. Laminated glass> 1-1. Glass Plate First, the outer glass sheet 11 and the inner glass sheet 12 will be described. These outer and inner glass sheets 11, 12 can be made of known glass sheets and can be made of heat-absorbing glass, ordinary clear glass, green glass, dark green glass, or UV green glass. However, these glass sheets 11 and 12 must achieve visible light transmittances that meet national safety standards for automobiles. For example, the outer glass sheet 11 can ensure the required solar absorption rate, while the inner glass sheet 12 can adjust the visible light transmittance to meet safety standards. The following illustrates an example of clear glass, heat-absorbing glass, and soda-lime glass.

[0037] (clear glass) SiO2: 70-73% by mass Al2O3: 0.6-2.4 mass% CaO: 7-12 mass% MgO: 1.0-4.5 mass% R2O: 13-15 mass% (R is an alkali metal) Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.08-0.14 mass%.

[0038] (Heat-absorbing glass) The composition of the heat-absorbing glass can be set as follows, for example: based on the composition of the transparent glass, the ratio of total iron oxide (T-Fe2O3) converted into Fe2O3 is 0.4 to 1.3 mass%, the ratio of CeO2 is 0 to 2 mass%, the ratio of TiO2 is 0 to 0.5 mass%, and the skeleton component of the glass (mainly SiO2 or Al2O3) is reduced only by the amount equivalent to the increase in T-Fe2O3, CeO2 and TiO2.

[0039] (Soda-lime glass) SiO2: 65-80 mass% Al2O3: 0-5 mass% CaO: 5-15% by mass MgO: 2% by mass or more NaO: 10-18 mass% K2O: 0-5% by mass MgO + CaO: 5-15 mass% Na2O+K2O: 10-20 mass% SO3: 0.05-0.3% by mass B2O3: 0-5% by mass Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.02-0.03 mass %.

[0040] (Green Glass) SiO2: 65-80 mass% Al2O3: 0-5 mass% CaO: 5-15% by mass MgO: 2% by mass or more NaO: 10-18 mass% K2O: 0-5% by mass MgO + CaO: 5-15 mass% Na2O+K2O: 10-20 mass% SO3: 0.05-0.3% by mass B2O3: 0-5% by mass Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.4-0.6 mass %.

[0041] (Dark green glass) SiO2: 65-80 mass% Al2O3: 0-5 mass% CaO: 5-15% by mass MgO: 2% by mass or more NaO: 10-18 mass% K2O: 0-5% by mass MgO + CaO: 5-15 mass% Na2O+K2O: 10-20 mass% SO3: 0.05-0.3% by mass B2O3: 0-5% by mass Total iron oxide converted to Fe2O3 (T-Fe2O3): 0.7-1.3 mass %.

[0042] The visible light transmittance of each glass sheet 11, 12 can also be adjusted. For example, by adjusting the Fe2O3 content and coloring the glass sheets 11, 12, the visible light transmittance can be adjusted. For example, a high Fe2O3 content results in a green color, creating the aforementioned green glass or dark green glass. On the other hand, a low Fe2O3 content results in the aforementioned clear glass.

[0043] The thickness of the laminated glass 10 involved in this embodiment is not particularly limited. As an example, the total thickness of the outer glass plate 11 and the inner glass plate 12 can be set to 2.1 to 6 mm. From the perspective of weight reduction, the total thickness of the outer glass plate 11 and the inner glass plate 12 is preferably set to 2.4 to 3.8 mm, more preferably 2.6 to 3.4 mm, and particularly preferably 2.7 to 3.2 mm.

[0044] The outer glass sheet 11 primarily requires durability against external damage and impact resistance. For automobile windshields, it requires resistance to impacts from flying objects such as pebbles. On the other hand, increasing the thickness increases the weight, making it less desirable. From this perspective, the thickness of the outer glass sheet 11 is preferably 1.8 to 2.3 mm, more preferably 1.9 to 2.1 mm. The appropriate thickness can be determined based on the intended use of the glass.

[0045] The thickness of the inner glass sheet 12 can be the same as that of the outer glass sheet 11. For example, to reduce the weight of the laminated glass 10, the thickness can be smaller than that of the outer glass sheet 11. Specifically, considering 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. More preferably, it is 0.8 to 1.3 mm. The thickness of each glass sheet 11 and 12 is described in detail below.

[0046] As described in detail below, the laminated glass 10 is curved to convexly face the vehicle exterior. In this case, the thickness is measured at two locations, above and below a center line (curve OP, described below) extending in the vertical direction from the left-right center of the laminated glass 10. The measuring instrument is not particularly limited; for example, a thickness gauge such as the SM-112 manufactured by TECLOCK Co., Ltd. can be used. During measurement, the curved surface of the laminated glass 10 is placed on a flat surface, and the thickness gauge is used to clamp the ends of the laminated glass 10.

[0047] <1-2. Interlayer> like Figure 3 As shown, the intermediate film 13 can be composed of three layers, with a soft core layer 136 sandwiched between a pair of harder outer layers 137 and 138. However, this configuration is not limiting, and the intermediate film 13 can be composed of multiple layers including the core layer 136 and at least one outer layer disposed on the outer glass sheet 11 side. Alternatively, the intermediate film 13 can be composed of a single layer.

[0048] 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 layer 136-138 are not particularly limited; for example, the material can be selected based on Young's modulus. Specifically, the Young's modulus of the core layer 136 is preferably 1-20 MPa at a frequency of 100 Hz and a temperature of 20°C, more preferably 1-18 MPa, and particularly preferably 1-14 MPa. Within this range, a decrease in sound transmission loss (STL) can be prevented in the low-frequency range of approximately 3500 Hz or less. On the other hand, to improve sound insulation performance in the high-frequency range, the Young's modulus of the outer layers 137 and 138 is preferably higher. At a frequency of 100 Hz and a temperature of 20°C, it can be set to 560 MPa or higher, 600 MPa or higher, 650 MPa or higher, 700 MPa or higher, 750 MPa or higher, 880 MPa or higher, or 1300 MPa or higher. The upper limit of the Young's modulus of the outer layer 522 is not particularly limited and can be set from the viewpoint of processability. For example, it is known from experience that processability, particularly cutting, becomes difficult when the Young's modulus is 1750 MPa or higher.

[0049] As a specific material, outer layers 137 and 138 can be made of, for example, polyvinyl butyral resin (PVB). Polyvinyl butyral resin is preferred due to its excellent adhesion to the outer glass plate 11 and its penetration resistance. Meanwhile, core layer 136 can be made of, for example, ethylene vinyl acetate resin (EVA) or a polyvinyl acetal resin that is softer than the polyvinyl butyral resin that constitutes the outer layers. By sandwiching a soft core layer, adhesion and penetration resistance comparable to a single-layer resin interlayer can be maintained, while significantly improving sound insulation performance.

[0050] The thickness of the core layer 136 is not particularly limited, but is preferably 0.1 to 2.0 mm, more preferably 0.1 to 0.6 mm. The thickness of each outer layer 137 , 138 is not particularly limited, but is preferably 0.1 to 2.0 mm, more preferably 0.1 to 1.0 mm, for example.

[0051] <2. Shielding layer> Next, the shielding layer 110 will be described. Figure 1 and Figure 2 As illustrated, in this embodiment, the shielding layer 110 is laminated on the inner surface 130 of the laminated glass 10 on the vehicle interior side (the inner surface of the inner glass plate 12) and is formed along the peripheral edge of the laminated glass 10. Figure 1 As shown, the shielding layer 110 can be divided into a peripheral region 111 along the periphery 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 from the periphery of the windshield. On the other hand, the protruding region 112 is provided to prevent the camera 2 disposed inside the vehicle from being visible from outside the vehicle.

[0052] However, if the shielding layer 110 blocks the camera 2's shooting range, the camera 2 cannot capture the scene outside the vehicle. Therefore, in this embodiment, a rectangular shooting window 113 is provided in the protruding area 112 of the shielding layer 110, corresponding to the camera 2, to enable the camera 2 to capture the scene outside the vehicle. Specifically, the shooting window 113 is the area where the shielding layer 110 is not formed, and through the shooting window 113, the scene outside the vehicle can be captured from inside the vehicle.

[0053] As described above, the shielding layer 110 may be laminated on the inner surface of the inner glass plate 12, or may be laminated on the inner surface of the outer glass plate 11 or the outer surface of the inner glass plate 12. Alternatively, the shielding layer 110 may be laminated on both the inner surface of the outer glass plate 11 and the inner surface of the inner glass plate 12.

[0054] Next, the material of the shielding layer 110 will be described. The material of the shielding layer 110 can be appropriately selected according to the embodiment as long as it can block the view from outside the vehicle. For example, dark ceramics such as black, brown, gray, and dark blue can be used.

[0055] When black ceramic is selected as the material for the shielding layer 110, for example, black ceramic is laminated on the periphery of the inner surface 130 of the inner glass plate 12 by screen printing or other methods, and the ceramic laminated along with the inner glass plate 12 is then heated. This allows the shielding layer 110 to be formed along the periphery of the inner glass plate 12. Furthermore, when printing the black ceramic, a localized area where the black ceramic is not printed can be provided. This allows the imaging window 113 to be formed. The ceramic used for the shielding layer 110 can be made of a variety of materials. For example, the ceramic compositions shown in Table 1 below can be used for the shielding layer 110.

[0056] [Table 1] *1, Main components: copper oxide, chromium oxide, iron oxide and manganese oxide *2, Main ingredients: bismuth borosilicate, zinc borosilicate <3. In-vehicle systems> Next, refer to Figure 5 The vehicle-mounted system 5 including the imaging device 2 and the image processing device 3 will be described. Figure 5 The configuration of the vehicle-mounted system 5 is illustrated as follows. Figure 5 As shown, the vehicle-mounted system 5 according to the present embodiment includes the above-mentioned imaging device 2 and an image processing device 3 connected to the imaging device 2 .

[0057] The image processing device 3 processes images captured by the imaging device 2. The image processing device 3 includes, for example, conventional hardware components such as a storage unit 31, a control unit 32, and an input / output unit 33 connected via a bus. However, the hardware configuration of the image processing device 3 is not limited to this example. The specific hardware configuration of the image processing device 3 may include additions, omissions, or additions to components as appropriate depending on the implementation.

[0058] The storage unit 31 stores various data and programs (not shown) used in the processing executed by the control unit 32. The storage unit 31 can be implemented, for example, as a hard disk or a recording medium such as a USB memory stick. Furthermore, the various data and programs stored in the storage unit 31 can be obtained from a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The storage unit 31 can also be referred to as an auxiliary storage device.

[0059] As described above, the laminated glass 10 is tilted relative to the vertical and curved. Furthermore, the camera 2 captures the exterior of the vehicle through the laminated glass 10. Therefore, the image captured by the camera 2 is distorted by factors such as the position, shape, refractive index, and optical defects of the laminated glass 10. Furthermore, the image is affected by inherent aberrations of the camera lens of the camera 2. Therefore, the storage unit 31 may also store correction data for correcting image distortion caused by aberrations between the laminated glass 10 and the camera lens.

[0060] The control unit 32 includes one or more processors, such as a microprocessor or CPU (Central Processing Unit), and peripheral circuits (such as ROM (Read Only Memory), RAM (Random Access Memory), and interface circuits) used for processing by these processors. ROM, RAM, and the like are also referred to as main storage devices, meaning they are located within the address space processed by the processors within 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.

[0061] The image processing unit 321 processes the captured image obtained by the camera 2. The processing of the captured image can be appropriately selected according to the embodiment. For example, the image processing unit 321 analyzes the captured image through pattern matching, etc., so that the subject captured in the captured image can be identified. In this embodiment, in order to capture the situation in front of the vehicle, the image processing unit 321 can also determine whether a person or other living thing is captured in front of the vehicle based on the subject recognition. In addition, when a person is captured in front of the vehicle, the image processing unit 321 can also output a warning message according to a prescribed method. In addition, for example, the image processing unit 321 can also perform prescribed processing on the captured image. Moreover, the image processing unit 321 can also output the processed captured image to a display device (not shown) such as a display connected to the image processing device 3.

[0062] The input / output unit 33 is one or more interfaces for transmitting and receiving data with devices external to the image processing device 3. Examples of the input / output unit 33 include an interface for connecting to a user interface or an interface such as a USB (Universal Serial Bus). In this embodiment, the image processing device 3 is connected to the imaging device 2 via the input / output unit 33 to obtain images captured by the imaging device 2.

[0063] As the image processing device 3 , a general-purpose device such as a PC (Personal Computer) or a tablet terminal may be used, in addition to a device specifically designed for the provided service.

[0064] In addition, the above-mentioned camera device 2 is mounted on a bracket (not shown in the figure), and the bracket is mounted on the shielding layer 110. Therefore, in this state, the mounting of the camera device 2 on the bracket and the mounting of the bracket on the shielding layer are adjusted in such a manner that the optical axis of the camera of the camera device 2 passes through the shooting window 113. In addition, a cover (not shown in the figure) is mounted on the bracket in such a manner as to cover the camera device 2. Therefore, the camera device 2 is arranged in a space surrounded by the laminated glass 10, the bracket and the cover, and cannot be seen from the inside of the vehicle. From the outside of the vehicle, only a part of the camera device 2 can be seen through the shooting window 113. Moreover, the camera device 2 and the above-mentioned input and output unit 33 are connected by a cable (not shown in the figure), which is led out from the cover and connected to the image processing device 3 arranged at a predetermined position in the vehicle.

[0065] <4. HUD device> Next, refer to Figure 5 and Figure 6 The HUD device 500 will be described. Figure 5 As shown, the HUD device 500 of this embodiment displays the first image and the second image as virtual images on the windshield 1. The first image 51 is an image for AR (Augmented Reality) display, and is displayed in a manner overlapping with objects included in the external scene. The objects are objects included in the external scene that can be seen through the laminated glass 10, such as roads, buildings, pedestrians, vehicles ahead, transportation machinery / materials, road signs, etc. In addition, the first image 51 is Figure 6 In this example, graphics or text such as arrows are displayed overlapping the road in the exterior scene. That is, the first image 51 is displayed as an image formed on an object approximately 3 meters or more from the driver's eyes. Furthermore, the first image 51 can move within the driver's field of view, following the object while remaining relatively fixed to it. Therefore, the relative positional relationship between the driver's eyes, the object in the exterior scene, and the first image 51 can be continuously maintained. Therefore, the shape of the first image 51 can be continuously updated at a predetermined period based on the relative position and shape of the object. This first image 51 is displayed by projecting image light emitted from the HUD device 500 onto the ARHUD area 501 on the laminated glass 10.

[0066] On the other hand, the second image 52 is displayed as an image on the laminated glass 10, without overlapping the external objects. Like the first image 51, the second image 52 can also be graphics or text. In this embodiment, for example, it is a numerical value indicating the vehicle speed. This second image 52 is displayed by projecting image light emitted from the HUD device 500 onto an area 502 outside the ARHUD area 501 on the laminated glass 10.

[0067] <5. ARHUD Area> Next, the ARHUD area 501 in the laminated glass 10 for displaying the first image 51 will be described. In this embodiment, the ARHUD area 501 is rectangular and located in the lower right corner of the laminated glass 10 (or the lower left corner for left-hand driving). However, this is not limiting and may be located elsewhere. The size of the ARHUD area 501 is preferably, for example, 50 mm x 50 mm or larger, and more preferably 100 mm x 100 mm or larger.

[0068] In this embodiment, the slope of the surface shape of the laminated glass 10 is specified so that the difference in the longitudinal direction and the difference in the lateral direction are less than a specified value, thereby enabling a suitable image to be displayed in the ARHUD area 501. First, on the inner side of the laminated glass 10, the area where the ARHUD area 501 is provided is specified as follows. First, as Figure 7 As shown, in ARHUD area 501, a total of m×n points Aij (1≤i≤m, 1≤j≤n) are defined, with m points in the horizontal direction and n points in the vertical direction arranged in a grid pattern. The vertical pitch PA1 of the points Aij can be set to, for example, 5 to 20 mm, and the horizontal pitch PA2 can be set to, for example, 5 to 20 mm.

[0069] Next, the inclination angle θAij of the surface of the laminated glass 10 between the adjacent points Aij and Ai(j+1) is calculated. This is referred to as the slope. In this case, Figure 7 The m vertical lines L1 of the point Aij shown in FIG. 1 are traced on the inner side surface of the inner glass plate 12, for example Figure 8 As shown, the surface concavity and convexity are detected. Based on the coordinates obtained by this detection, for example Figure 9 As shown, the inclination angle θAij (rad) is calculated based on the following formula.

[0070] θAij≈tanθ≈((z(Aij)-z(Ai(j+1))) / (x(Aij)-x(Ai(j+1))), where 1≤i≤m, 1≤j≤n-1 Here, the coordinate of point Aij in the plane direction is denoted by x(Aij), and the coordinate of point Aij in the thickness direction of the laminated glass 10 is denoted by z(Aij). Since (z(Aij) - z(Ai(j+1)) used in calculating θAij is the coordinate difference, the origin of the thickness direction coordinate zAij can be set at any position. For example, the coordinates of any corner of the vehicle-exterior surface of the inner glass sheet 12 can be used as the origin.

[0071] In this way, n-1 inclination angles θAij are obtained on each vertical line L1. Furthermore, since there are m vertical lines, a total of m×n-1 inclination angles θAij can be obtained.

[0072] Next, calculate the longitudinal difference X1 in slope (angle θAij). X1 is the difference between θAij and another θAij point (excluding points located at the same horizontal position) divided by the vertical distance (mm) between these two points. This yields m × (n - 1) - 1 slope differences X1. For example, the slope difference X1 between θA11 and θA12, where the vertical distance between θA11 and θA12 is PA1, is (θA11 - θA12) / P1. Similarly, the slope difference X1 between θA11 and θAmn, where the vertical distance between θA11 and θAmn is PA1 × (n - 1), is (θA11 - θAmn) / PA1 × (n - 1). Alternatively, for example, the slope difference X1 between θA23 and θA45 is (θA23 - θA45) / PA1 × 2, because the vertical distance between θA23 and θA45 is PA1 × 2. However, when the vertical distance between θA11 and θA21 is zero, the longitudinal slope difference X1 cannot be determined.

[0073] The longitudinal differences X1 of all slopes calculated in this manner satisfy the following formula (1).

[0074] X1<0.0008(rad / mm) (1) Furthermore, X1 is preferably less than 0.0004, more preferably less than 0.0001, and particularly preferably less than 0.00008.

[0075] Next, we'll explain how to calculate the lateral slope difference Y1. Y1 is the value obtained by dividing the difference between two points, θAij and another θAij, by the horizontal distance (mm) between these two points. This yields m × (n - 1) - 1 slope differences Y1. For example, the slope difference Y1 between θA11 and θA21 is (θA11 - θA21) / P2, because the horizontal distance between θA11 and θA21 is PA2. Similarly, the slope difference X1 between θA11 and θAmn is (θA11 - θAmn) / PA2 × (m - 1), because the horizontal distance between θA11 and θA21 is PA2 × (m - 1). Alternatively, for example, the slope difference Y1 between θA23 and θA45 is (θA23 - θA45) / PA2 × 2, because the horizontal distance between θA23 and θA45 is PA2 × 2. However, when the horizontal distance is zero, as in the case of θA11 and θA12, the slope difference Y1 cannot be determined.

[0076] The lateral differences Y1 of all slopes calculated in this manner satisfy the following formula (2).

[0077] Y1<0.0003(rad / mm) (2) Furthermore, Y1 is preferably less than 0.0001, more preferably less than 0.00008, and particularly preferably less than 0.00006.

[0078] In addition, it is preferable to appropriately combine the examples of the upper limit values ​​shown in formulas (1) and (2). For example, a combination such as X1 < 0.004 and Y1 < 0.0001 can be used. In addition, as shown in Sample 1 described later, X1 can be set to 0.00006 (rad / mm) or less, and Y1 can be set to 0.00005 (rad / mm) or less. In addition, as shown in Sample 2 described later, X1 can be set to 0.00029 (rad / mm) or less, and Y1 can be set to 0.00007 (rad / mm) or less.

[0079] <6. Outer Area> Next, the surface shape of the outer region 502 for displaying the second image 52 in the laminated glass 10 will be described. In the outer region 502, the longitudinal difference X2 of the slope and the lateral difference Y2 of the slope are also calculated. Figure 10As shown, a rectangular area is defined at an arbitrary position in the outer area 502, and a point Bij is defined within the area similarly to the ARHUD area 501. Next, the vertical slope difference X2 and the horizontal slope difference Y2 are calculated using the same method as for the ARHUD area 501.

[0080] The longitudinal difference X2 and the lateral difference Y2 of all slopes calculated in this way satisfy the following equations (3) and (4).

[0081] 0.0008 (rad / mm)<X2<0.0015 (rad / mm) (3) 0.0003 (rad / mm)<Y2<0.0010 (rad / mm) (4) Furthermore, it is more preferable to satisfy the following formula (5) and formula (6).

[0082] 0.0008 (rad / mm)<X2<0.0010 (rad / mm) (5) 0.0005 (rad / mm)<Y2<0.0008 (rad / mm) (6) The upper limit value and the lower limit value shown in the above formulas (3) to (6) can be combined as appropriate.

[0083] <7. Windshield Manufacturing Method> Next, an example of a method for manufacturing the windshield configured as described above will be described. First, a method for manufacturing the laminated glass 10 will be described.

[0084] First, the aforementioned shielding layer 110 is laminated onto at least one of the flat outer glass sheet 11 and the inner glass sheet 12. Next, these glass sheets 11 and 12 are formed into a curved shape. The forming method is not particularly limited, and known methods can be employed. For example, after passing the flat glass sheet through a heating furnace, it can be pressed using upper and lower molds to form a curved shape.

[0085] After the outer and inner glass sheets 11, 12 are formed into a curved shape, the interlayer film 13 is sandwiched between the outer and inner glass sheets 11, 12. The interlayer film is then placed in a rubber bag and pre-bonded at approximately 70-110°C while decompressing the bag. At this point, the reflective film 135 and the adhesive layers 131, 132, which constitute the interlayer film 13, are stacked and positioned between the two glass sheets 11, 12. Pre-bonding methods other than those described above can also be used. For example, the interlayer film 13 is sandwiched between the outer and inner glass sheets 11, 12 and heated in an oven at 45-65°C. The laminated glass is then pressed with rollers at 0.45-0.55 MPa. The laminated glass is then heated again in an oven at 80-105°C and pressed again with rollers at 0.45-0.55 MPa. This completes the pre-bonding process.

[0086] Next, main bonding is performed. The pre-bonded laminated glass is subjected to main bonding in an autoclave at, for example, 8 to 15 atmospheres and 100 to 150°C. Specifically, main bonding can be performed at, for example, 14 atmospheres and 145°C. In this manner, the windshield 1 according to this embodiment can be manufactured.

[0087] Furthermore, in order to make the difference in slope equal to or less than a predetermined value as described above, this can be achieved by, for example, making the surface of the upper mold as flat as possible by pressing.

[0088] <8. Features> The windshield 1 described above can provide the following effects.

[0089] (1) The inventors of the present invention have discovered that, in order to improve the image quality of the image projected by the image light emitted from the HUD device 500, it is not important to simply determine the value of the surface irregularities (e.g., surface roughness) of the laminated glass 10 surface, but rather to ensure that the angles of the irregularities on the surface of the inner glass plate 12 do not have locally steep portions. Specifically, the first image 51, which is an AR image, is displayed so as to overlap an object outside the vehicle and be imaged at a distance of approximately 3 meters or more from the driver. Therefore, if there is a steep portion on the surface of the inner glass plate 12, for example, the first image 51 to be overlapped with a graphic or the like may be offset, which may deteriorate the appearance.

[0090] In this regard, the inventors of the present invention have found that, as described above, in the ARHUD area 501, by satisfying the formula (1) regarding the longitudinal difference X1 of the slope and the formula (2) regarding the lateral difference Y1 of the slope, the deformation of the first image 51 can be suppressed. Regarding X1 and Y1, for example, not only the difference X1 between adjacent slopes such as θ11 and θ12 is calculated, but also the difference X1 between distant slopes such as θ11 and θ45 is calculated. When the longitudinal difference X1 between adjacent slopes is large, there is a possibility that deformation will occur in the first image 51 (arrow). On the other hand, for example Figure 8 As shown, even if the longitudinal difference X1 between adjacent slopes is small, if the longitudinal difference X1 between the slopes of distant locations is large, a difference in deformation will occur between the first images 51 displayed at distant locations, which may cause a user to feel uncomfortable.

[0091] Here, a comparison is made between Sample 1 in which X1 is 0.00006 (rad / mm) and Y1 is 0.00005 (rad / mm) and Sample 2 in which X1 is 0.00029 (rad / mm) and Y1 is 0.00007 (rad / mm). Figure 11 Indicates sample 1, Figure 12 This shows sample 2. To evaluate deformation, a grid with a single side of 14 mm was marked on the area used as the ARHUD area 501 for each sample. Then, using the rectangular frame marked with zeros as the reference frame, four frames 1 to 4 were selected, sharing the four vertices of this reference frame. A correct reference square (indicated by the solid line) sharing the four vertices of the reference frame was superimposed on these frames 1 to 4 to verify the positional misalignment of the vertices of frames 1 to 4 and the parallelism of their sides.

[0092] Figure 11 In the sample 1 shown, since X1 is small, the frames 1 to 4 are almost not offset from the vertices and sides of the reference square. Figure 12 In Sample 2 shown, since X1 is larger than that of Sample 1, the deviations of frames 1 to 4 from the vertices and sides of the reference square are larger than those of Sample 1. However, since X1 of Sample 2 is also smaller than the value specified by the above-mentioned formula (1), the inventors of the present invention have confirmed that there is no problem with the deformation of the first image.

[0093] However, since the windshield 1 is tilted in the front-to-back direction, the vertical difference in slope tends to affect the depth of field of the first image 51, resulting in a tendency for X1 to be greater than Y1. Therefore, in this embodiment, the upper limit of X1 is set to be greater than the upper limit of Y1. However, the inventors have confirmed that the aforementioned effects can be achieved even in this manner. This also applies to the relationship between X2 and Y2.

[0094] (2) The same is true for the difference in slope in the outer region 502. However, in the outer region 502, the second image 52 is displayed on the windshield 1 rather than as an AR image. Therefore, the influence of deformation caused by the surface shape of the inner glass plate 12 is smaller than that of the first image 51 displayed as an image outside the vehicle. From this perspective, the inventors of the present invention have discovered that in the outer region 502, by satisfying the above-mentioned equations (3) and (4), the deformation of the second image 52 can be suppressed.

[0095] For example, in Sample 1, X2 and Y2 were measured in area 502 outside the ARHUD area 501. X2 was 0.00086 (rad / mm) and Y2 was 0.00066 (rad / mm), satisfying Equations (3) and (4). When the second image (numerical value) was projected onto area 502 of Sample 1, no distortion was observed.

[0096] <9. Modifications> While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications can be made without departing from the main purpose thereof. The following modifications can also be appropriately combined. In addition, the following modifications can also be appropriately combined with the above embodiment.

[0097] <9-1> The positions and number of points A and B in the ARHUD region 501 and outer region 502 are not particularly limited. Even if they differ from one embodiment to another, the difference in slope is divided by the pitch of points A and B. Therefore, regardless of the positions of points A and B, the same effect can be achieved. Furthermore, the positions of the ARHUD region 501 and outer region 502 are not particularly limited and can be appropriately set to correspond to the positions where the first image 51 and the second image 52 are displayed.

[0098] <9-2> In the above embodiment, the slope differences X1 and Y1 of the ARHUD area satisfy both equations (1) and (2). However, as described above, considering that the longitudinal slope of the uneven surface of the inner glass plate 12 has a greater influence on the deformation of the AR image 51, even if both equations (1) and (2) are not satisfied, at least equation (1) may be satisfied.

[0099] <9-3> In the above embodiment, the slope differences X1 and Y1 of the ARHUD region are both smaller than the slope differences X2 and Y2 of the outer region 502 . However, for example, any one of X1 < X2 and Y1 < Y2 may be satisfied.

[0100] <9-4> The shape of the shielding layer 110 is an example, and the configuration is not particularly limited, and the shape may be appropriately changed depending on the device to be installed.

[0101] <9-5> In the above embodiment, the imaging window 113 is formed on the shielding layer 110 and the imaging device 2 is disposed thereon. However, such an imaging window 113 and the imaging device 2 may not be provided.

[0102] <9-6> The position (height) at which the first image 51 is displayed may be changed in the inner glass plate 12 by adjustment performed by the HUD device 500 .

[0103] <9-7> The longitudinal cross-section of the laminated glass 10 can be wedge-shaped. In this case, at least one of the outer glass sheet, the inner glass sheet, and the interlayer film can be wedge-shaped. In this case, within the ARHUD region, points Aij are defined at intervals of 20 mm or less. When the wedge angle at each point Aij is measured on the inboard surface of the windshield using an interferometer (where m and n are each set to 240° or greater), the difference between the maximum and minimum wedge angles can be kept within 0.32 mrad.

[0104] Explanation of symbols 1: windshield; 11: outer glass plate; 12: inner glass plate; 13: intermediate film; 131: first adhesive layer; 132: second adhesive layer; 135: reflective film.

Claims

1. A windshield, characterized in that: The windshield has an ARHUD area for displaying a first image emitted from a head-up display device superimposed on an external scene seen from outside the vehicle. The windshield includes a plate-shaped glass member having the ARHUD area. In the ARHUD region, the slope of the surface shape of the glass member is specified, and when the longitudinal difference is X1, the following conditions are satisfied: X1<0.0008(rad / mm) In the ARHUD area, m points in the horizontal direction and n points in the vertical direction are provided in a grid pattern, with a total of m×n points Aij, where 1≤i≤m, 1≤j≤n, On the surface of the glass member on the vehicle interior side, the inclination angle between the vertically adjacent points Aij and Ai(j+1) is θAij (rad) as the slope, where 1≤i≤m, 1≤j≤n-1, X1 is a value obtained by dividing the difference between two points of an arbitrary θAij and another θAij excluding points located at the same horizontal position by the vertical distance between the two points.

2. The windshield according to claim 1, wherein: In the ARHUD area, when the lateral difference in the slope is set to Y1, the following conditions are met: Y1<0.0003(rad / mm) Here, Y1 is a value obtained by dividing the difference between two points of arbitrary θA11 and other θAij excluding points located at the same vertical position by the horizontal distance between the two points.

3. The windshield according to claim 1, wherein: When the longitudinal difference of the slope in the outer area outside the ARHUD area is defined as X2 and the lateral difference of the slope is defined as Y2, at least one of the following equations is satisfied: X1<X2 Y1<Y2 In the outer area, a total of m×n points Bij are arranged in a grid pattern, m in the horizontal direction and n in the vertical direction, where 1≤i≤m, 1≤j≤n, On the surface of the glass member on the vehicle interior side, the inclination angle between the vertically adjacent points Bij and Bi,j+1 is θBij (rad), where 1≤i≤m, 1≤j≤n-1, X2 is a value obtained by dividing the difference between any two points of θBij and other θBij, excluding points located at the same horizontal position, by the vertical distance between the two points. Y2 is a value obtained by dividing the difference between two points of an arbitrary θBij and another θBij excluding points located at the same vertical position by the horizontal distance between the two points.

4. The windshield according to claim 3, wherein: Satisfies: 0.0008 (rad / mm) < X2 < 0.0015 (rad / mm); and 0.0003 (rad / mm)<Y2<0.0010 (rad / mm).

5. The windshield according to claim 1, wherein: The glass component has: inner glass panel; an outer glass plate disposed opposite to the inner glass plate; and An intermediate film bonds the inner glass plate and the outer glass plate.

6. The windshield according to claim 3, wherein: The second image emitted from the head-up display device is displayed in the outer area.

7. The windshield according to claim 1, wherein: In the ARHUD area, the points Aij are defined with a pitch of less than 20 mm. When the wedge angle at each point Aij is measured on the vehicle interior surface of the glass member using an interferometer, the difference between the maximum and minimum values ​​of the wedge angle is within 0.32 mrad, where m and n are each set to be greater than 240.

8. The windshield according to claim 1, wherein: The first image is configured to be formed at a distance of more than 3 meters in front of the driver.

9. The windshield according to claim 1, wherein: The area of ​​the ARHUD region is greater than 50 mm×50 mm.

10. The windshield according to claim 1, wherein: The first image is at least one of text and graphics. The first image is configured to overlap with at least one of a building, a road, a pedestrian, and a transport machine included in the outside scene.

11. The windshield according to claim 1, wherein: The height of the first image displayed on the glass member is configured to change.

Images