Display device

Abstract

The present invention suppresses cracking of a cover member. This display device 1 includes: a bottom member 5; a display panel 3 provided on the bottom member 5; side wall members 8b and 8c provided around the display panel 3; and a glass cover member 2 provided on the display panel 3 and the side wall members 8b and 8c and having a thickness tcg of 0.3-0.7 mm. When the orientation from the bottom member 5 toward the cover member 2 is defined as a first orientation in the thickness direction of the cover member 2, the cover member 2 has a first main surface 2A on the first orientation side, a second main surface 2B on the opposite side to the first main surface 2A, and an end surface 2C connecting the first main surface 2A and the second main surface 2B. When a parameter A is a value represented by formula (1), a parameter B is a value represented by formula (2), a parameter C is a value represented by formula (3), a parameter D is a value represented by formula (4), and a parameter T is a value represented by formula (5), the parameter T is less than 0.

Description

display device

[0001] The present invention relates to a display device.

[0002] Liquid crystal displays and organic electroluminescence (EL) displays are often used in vehicle-mounted display devices that display information necessary for driving. These display devices are sometimes equipped with a glass cover member to protect the front surface. For example, Patent Document 1 (JP-A-2005-102626) describes a vehicle-mounted display device in which the impact resistance of the cover member can be improved.

[0003] International Publication No. 2016 / 027812

[0004] For example, in-vehicle display devices and the like are required to have such excellent impact resistance that the cover member will not break even if it is hit by the head of an occupant in the event of a vehicle collision.

[0005] An object of the present invention is to provide a display device that can prevent cracking of a cover member.

[0006] A display device according to the present disclosure is a display device having a bottom member, a display layer provided on the bottom member, side wall members provided around the display layer, and a glass cover member provided on the display layer and the side wall members and having a thickness of 0.3 mm or more and 0.7 mm or less, wherein, when a direction from the bottom member toward the cover member in a thickness direction of the cover member is defined as a first direction, the cover member has a first main surface on the first-direction side, a second main surface opposite to the first main surface, and an end surface connecting the first main surface and the second main surface, and wherein when parameter A is a value shown in the following formula (1), parameter B is a value shown in the following formula (2), parameter C is a value shown in the following formula (3), parameter D is a value shown in the following formula (4), and parameter T is a value shown in the following formula (5), the parameter T is less than 0.

[0007] A = Ecg x tcg ２ ...(1) B=Σ(Eb×tb ２ ) ...(2) C=Σ(Eb×tc) ...(3) D=Ed×td ２...(4) T=0.212245+A(-0.00997+0.000124×B+0.0000362×C-0.000022×D-0.00809×G)-0.00817×B-0.00183×C+0.001722×D+0.957752×G ...(5)

[0008] where Ecg is the Young's modulus (GPa) of the cover member, tcg is the thickness (mm) of the cover member, Eb is the Young's modulus (GPa) of the side wall member, tb is the thickness (mm) of the portion of the side wall member that protrudes outward from the end face of the cover member, tc is the protrusion length (mm) of the portion of the side wall member that protrudes outward from the end face of the cover member, Ed is the Young's modulus (GPa) of the bottom member, td is the thickness (mm) of the bottom member, and G is the protrusion length (mm) of the first main surface of the cover member in the first direction from the surface of the first-facing side of the frame member that is adjacent to the outer side of the end face of the cover member.

[0009] According to the present invention, cracking of the cover member can be suppressed.

[0010] FIG. 1 is a schematic diagram showing a display device according to this embodiment. FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. FIG. 4 is a bottom view of a bottom member. FIG. 5 is a partially enlarged view of a cross section of a display device according to this embodiment. FIG. 6 is a schematic partially enlarged view of a bottom member provided with ribs.

[0011] A display device according to the present disclosure includes a bottom member, a display layer provided on the bottom member, sidewall members provided around the display layer, and a glass cover member provided on the display layer and the sidewall members and having a thickness of 0.3 mm to 0.7 mm, wherein, when a direction from the bottom member toward the cover member in a thickness direction of the cover member is defined as a first direction, the cover member has a first main surface on the first-direction side, a second main surface opposite the first main surface, and an end surface connecting the first main surface and the second main surface, and wherein, when parameter A is the value shown in the above formula (1), parameter B is the value shown in the above formula (2), parameter C is the value shown in the above formula (3), parameter D is the value shown in the above formula (4), and parameter T is the value shown in the above formula (5), the parameter T is less than 0. Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes configurations that combine the respective embodiments. Furthermore, the numerical values ​​include the range of rounding.

[0012] (1. Configuration of the Display Device) FIG. 1 is a schematic diagram showing a display device according to the present embodiment, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. As shown in FIG. 1, the display device 1 according to the present embodiment is an in-vehicle display device installed in a vehicle. The display device 1 is, for example, a car navigation device, but its use is arbitrary and it may be another display device installed in a vehicle, such as a display audio. As will be described in detail later, the display device 1 is fixed to an interior part 10 of the vehicle via a fixing point P formed on the back surface opposite the display surface. The interior part 10 is a member installed inside the vehicle, and is, for example, a part of the dashboard of the vehicle. The display device 1 of the present embodiment is particularly suitable for use as a display device installed in the front row of the vehicle, i.e., in the case of a passenger car, on the dashboard in front of the driver's seat or passenger seat. However, the use of the display device 1 is arbitrary and it does not have to be installed in a vehicle. Hereinafter, the thickness direction of the display device 1 is referred to as the Z direction. When the display device 1 is mounted on a vehicle, one direction perpendicular to the Z direction and along a horizontal plane (left-right direction in the example of FIG. 1 ) is referred to as the X direction. The direction perpendicular to the Z direction and the X direction (up-down direction in the example of FIG. 1 ) is referred to as the Y direction. Furthermore, one direction along the X direction (rightward in the example of FIG. 1 ) is referred to as orientation X1. The other direction along the X direction (leftward in the example of FIG. 1 ) is referred to as orientation X2. One direction along the Y direction (direction heading vertically upward) is referred to as orientation Y1. The other direction along the Y direction (direction heading vertically downward) is referred to as orientation Y2. One direction along the Z direction (direction from the back surface of the display device 1 toward the display surface) is referred to as orientation Z1 (first orientation). The other direction along the Z direction (direction from the display surface of the display device 1 toward the back surface) is referred to as orientation Z2. In this embodiment, the end of the display device 1 on the Y1 side is the upper end (top end) in the vertical direction.

[0013] 2 , the display device 1 includes a cover member 2, a display panel 3 as a display layer, a backlight unit 4, a bottom member 5, and a peripheral member 8. The display device 1 is arranged in the direction Z1 with the bottom member 5, backlight unit 4, display panel 3, and cover member 2 lined up (overlapping) in this order, and a frame-shaped peripheral member 8 is arranged around the cover member 2, display panel 3, and backlight unit 4. In other words, the cover member 2, bottom member 5, and peripheral member 8 form a housing 1A that houses the display panel 3. The bottom member 5 covers the back surfaces (surfaces opposite to the display side) of the cover member 2 and the display panel 3, and the peripheral member 8 covers the side surfaces of the cover member 2 and the display panel 3.

[0014] (Cover Member) The cover member 2 is a transparent plate-like member that transmits visible light. The cover member 2 is provided on the display panel 3 and the side wall members (described later) (on the Z1-direction side of the display panel 3 and the side wall members). The cover member 2 has a first main surface 2A that is the main surface on the Z1-direction side (display surface side), a second main surface 2B that is the main surface on the Z2-direction side (back side), and an end surface 2C connecting the first main surface 2A and the second main surface 2B. The end surface 2C can also be considered a side surface of the cover member 2. Preferably, the second main surface 2B of the cover member 2 faces the display panel 3, and the first main surface 2A is the surface exposed to the outside, opposite the display panel 3. The cover member 2 may have a printed layer on the second main surface 2B side (on the second main surface 2B). The printed layer is a layer that shields the cover member 2 and has a lower transmittance to visible light than the cover member 2. Examples of the printed layer include a black layer with low visible light transmittance and a layer with a wood grain pattern. The printed layer is preferably provided so as to surround the area of ​​the second main surface 2B that overlaps with the display panel 3 when viewed from the Z direction. Furthermore, the cover member 2 may be provided on the first main surface 2A side with a functional layer including at least one of an antiglare layer, an antireflection layer, and an antifouling layer.

[0015] The thickness tcg of the cover member 2 is 0.3 mm to 0.7 mm, preferably 0.4 mm to 0.7 mm, more preferably 0.4 mm to 0.55 mm, and more preferably 0.4 mm to less than 0.5 mm. The thickness tcg is the length in the Z direction from the first main surface 2A to the second main surface 2B.

[0016] In this embodiment, the cover member 2 has a rectangular, flat plate shape when viewed from the Z direction. Regarding the size of the cover member 2, for example, if the cover member 2 is rectangular, the length in the longitudinal direction (X direction in this embodiment) is 50 mm to 1500 mm, preferably 100 mm to 1200 mm, and the length in the lateral direction (Y direction in this embodiment) is 40 mm to 500 mm, preferably 100 mm to 300 mm. However, the cover member 2 is not limited to a rectangular, flat plate shape when viewed from the Z direction, and may have any shape, such as an elliptical shape when viewed from the Z direction, or a curved shape. The size of the cover member 2 may also be arbitrary. When the cover member 2 has a curved shape, the thickness direction of the cover member 2 at the center position of the main surface of the cover member 2 may be defined as the Z direction.

[0017] The Young's modulus Ecg of the cover member 2 is preferably 60 GPa or more and 90 GPa or less, more preferably 70 GPa or more and 80 GPa or less, and even more preferably 70 GPa or more and 75 GPa or less. The Young's modulus of each member including the cover member 2 may be determined by a tensile test (JIS K7161-1, 2: 2014, JIS K7113: 1995).

[0018] In this embodiment, the cover member 2 is made of glass. The cover member 2 is preferably tempered glass, and the tempered glass is preferably chemically tempered glass. When the cover member 2 is chemically tempered glass, the thickness (DOL) of the compressive stress layer of the cover member 2 is, for example, preferably 10 μm or more, more preferably 10 μm or more and 180 μm or less, even more preferably 15 μm or more and 50 μm or less, even more preferably 25 μm or more and 50 μm or less, and even more preferably 30 μm or more and 50 μm or less. The surface compressive stress (CS) of the compressive stress layer is preferably 500 MPa or more, more preferably 650 MPa or more, and even more preferably 750 MPa or more. There is no particular limit to the upper limit, but for example, CS is preferably 1200 MPa or less. A method of obtaining chemically tempered glass by subjecting glass to chemical tempering treatment typically involves kneading the glass with KNO ３One method is to immerse the material in a molten salt, perform an ion exchange treatment, and then cool it to near room temperature. ３ The treatment conditions, such as the temperature of the molten salt and the immersion time, may be set so that the surface compressive stress and the thickness of the compressive stress layer are at the desired values. Examples of the glass type include soda lime glass, aluminosilicate glass (SiO ２ -Al ２ O ３ -Na ２ Among them, aluminosilicate glass is preferable from the viewpoint of strength. Examples of glass materials include SiO, expressed in mole percent based on oxides. ２ 50% or more and 80% or less, Al ２ O ３ 1% or more and 20% or less, Na ２ O is 6% or more and 20% or less, K is ２ O is 0% or more and 11% or less, MgO is 0% or more and 15% or less, CaO is 0% or more and 6% or less, and ZrO ２ Examples of suitable glass materials include glass materials containing 0% to 5% of CI. Chemically strengthened glass based on aluminosilicate glass (for example, "Dragon Trail (registered trademark)" manufactured by AGC) is also suitable.

[0019] More specifically, the following glass compositions are preferred for the glass for the cover member 2. For example, "containing 0 to 25% MgO" means that MgO is not essential but may be contained up to 25%. The following glass (i) is included in soda lime silicate glass, the following glasses (ii) and (iii) are included in aluminosilicate glass, and the following glasses (iv) to (vi) are included in lithium aluminosilicate glass. (i) A composition expressed in mole percent based on oxides, where SiO ２ 63 to 73%, Al ２ O ３ 0.1 to 5.2%, Na ２ O 10-16%, K ２ 0 to 1.5% O, Li ２ (ii) A glass containing 0 to 5.0% of O, 5 to 18% of MgO, and 1 to 10% of CaO, the composition of which, expressed in mole percent on an oxide basis, is: SiO ２50 to 74%, Al ２ O ３ 5 to 15%, Na ２ O 10-20%, K ２ O 0 to 8%, Li ２ O 0 to 5.0%, MgO 2 to 15%, CaO 0 to 6% and ZrO ２ Contains 0 to 5% of SiO ２ and Al ２ O ３ The total content of 65-85%, Na ２ O and K ２ (iii) A glass having a composition expressed in mole percent on an oxide basis of SiO ２ 68 to 80%, Al ２ O ３ 4-10%, Na ２ O 5-15%, K ２ O 0-1%, Li ２ O 0 to 5.0%, MgO 4 to 15% and ZrO ２ (iv) A glass containing 0 to 1% of SiO ２ 67 to 75%, Al ２ O ３ 0-4%, Na ２ O 7-15%, K ２ O 1 to 9%, Li ２ O 0 to 5.0%, MgO 6 to 14% and ZrO ２ Contains 0 to 1.5% of SiO ２ and Al ２ O ３ The total content of 71-75%, Na ２ O and K ２ (v) A glass having a composition expressed in mole percent on an oxide basis of SiO ２ 50 to 73%, Al ２ O ３ 5 to 20%, B ２ O ３ 0 to 6%, P ２ O ５ 0 to 10%, Li ２4-12% O, Na ２ O 3-20%, K ２ O 0-5%, MgO 0-8%, CaO 0-2%, SrO 0-5%, BaO 0-5%, ZnO 0-5%, TiO ２ 0 to 2%, ZrO ２ (vi) A glass containing 0 to 4% of SiO ２ 58 to 80%, Al ２ O ３ 13-18%, B ２ O ３ 0 to 5%, P ２ O ５ 0.5-4%, Li ２ 3-10% O, Na ２ O 5-20%, K ２ O 0-2%, MgO 0-11%, CaO 0-20%, SrO 0-20%, BaO 0-15%, ZnO 0-10%, TiO ２ 0 to 1%, ZrO ２ Glass containing 0 to 2% of

[0020] (Display Panel) The display panel 3 is a panel that displays images and is provided on the bottom member 5 (on the Z1-direction side of the bottom member). More specifically, the display panel 3 is disposed on the Z2-direction side of the cover member 2 so as to overlap the cover member 2. The display surface of the display panel 3, which is the surface on the Z1-direction side, is adhered to the second main surface 2B of the cover member 2 by an adhesive layer (not shown). The adhesive layer is, for example, an OCA (Optical Clear Adhesive) film or OCA tape, and its thickness (length in the Z direction) is, for example, 5 μm or more and 400 μm or less, and preferably 50 μm or more and 200 μm or less.

[0021] The display panel 3 may be a liquid crystal panel, an organic EL panel, a flexible organic EL panel, a plasma display panel (PDP), an electronic ink panel, or the like, and may also have a touch panel. When the display panel 3 has a glass substrate, the glass substrate is the thickest and determines the rigidity of the entire display panel. Therefore, the Young's modulus of the glass substrate may be considered to be the Young's modulus of the display panel 3. The Young's modulus of the display panel 3 is preferably 1.5 GPa or more, more preferably 60 GPa or more, and even more preferably 70 GPa or more. The Young's modulus of the display panel 3 is preferably 90 GPa or less, and more preferably 75 GPa or less. The upper and lower limit numerical ranges may be appropriately combined; that is, the Young's modulus of the display panel 3 is preferably 1.5 GPa or more and 90 GPa or less, more preferably 60 GPa or more and 75 GPa or less, and even more preferably 70 GPa or more and 75 GPa or less. The thickness of the display panel 3 is preferably 0.05 mm to 2.0 mm, more preferably 1.0 mm to 1.3 mm, and even more preferably 1.1 mm to 1.3 mm. The thickness of the display panel 3 is the length in the Z direction from the main surface of the display panel 3 on the Z1 direction side to the main surface on the Z2 direction side.

[0022] As shown in FIG. 1 , distance S1 is the distance from the end of the cover member 2 on the Y1-direction side to the end of the display panel 3 on the Y1-direction side, as viewed from the Z direction. From the viewpoint of adhering and holding the cover member 2 with sufficient adhesive strength, distance S1 is preferably 2 mm or more and 30 mm or less, and more preferably 5 mm or more and 20 mm or less. The same numerical range of distance S1 can also be applied to the distance from the end of the cover member 2 on the Y2-direction side to the end of the display panel 3 on the Y2-direction side. Also, as shown in FIG. 1 , distance S2 is the distance from the end of the cover member 2 on the X1-direction side to the end of the display panel 3 on the X1-direction side, as viewed from the Z direction. From the viewpoints of adhesive strength and design, distance S2 is preferably 2 mm or more and 200 mm or less, and more preferably 5 mm or more and 150 mm or less. The same numerical range of distance S2 can also be applied to the distance from the end of the cover member 2 on the X2-direction side to the end of the display panel 3 on the X2-direction side.

[0023] (Backlight Unit) The backlight unit 4 is a light source that irradiates the display panel 3 with light for displaying an image, and is disposed on the Z2 side of the display panel 3 so as to overlap the display panel 3.

[0024] The backlight unit 4 is generally composed of components such as a lens sheet, a diffusion sheet, a light guide plate, a lamp, and a reflector. Among these components, the light guide plate is usually the thickest, and the light guide plate determines the rigidity of the entire backlight unit 4. Therefore, the Young's modulus of the light guide plate may be considered to be the Young's modulus of the backlight unit 4. The Young's modulus of the backlight unit 4 is preferably 1 GPa to 90 GPa, more preferably 2 GPa to 85 GPa, and even more preferably 60 GPa to 85 GPa. The thickness of the backlight unit 4 is preferably 1 mm to 10 mm, more preferably 2 mm to 6 mm, and even more preferably 3 mm to 5 mm. The thickness of the backlight unit 4 is the length in the Z direction from the main surface of the backlight unit 4 facing the Z1 direction to the main surface of the backlight unit 4 facing the Z2 direction.

[0025] The display device 1 does not necessarily need to be provided with a backlight unit 4. In this case, the display device 1 is arranged in the direction Z2 with the cover member 2, the display panel 3, and the bottom member 5 lined up (overlapping) in this order. When the backlight unit 4 is not provided, a self-luminous display panel that does not require the backlight unit 4, such as an organic EL panel or a micro LED panel, is selected as the display panel 3.

[0026] (Bottom Member) The bottom member 5 is disposed on the Z2 side of the display panel 3 (backlight unit 4 in this embodiment) so as to overlap the display panel 3 (backlight unit 4 in this embodiment), and can be considered the bottom part of the housing.

[0027] The bottom member 5 may include a plate portion 6 and a rib 7. The plate portion 6 is a plate-shaped member arranged to overlap the display panel 3. The rib 7 is a member formed to protrude from the main surface 6A of the plate portion 6 on the Z2 direction side, and in this embodiment, is in the shape of a quadrangular prism. By forming the bottom member 5 in a shape that includes the rib 7, the display device 1 can be made lighter than if the bottom member 5 were formed in a thick plate shape without the rib 7.

[0028] FIG. 4 is a bottom view of the bottom member 5. When the bottom member 5 of this embodiment is viewed from the Z2 direction toward the Z1 direction as shown in FIG. 4 , a plurality of ribs 7 are arranged in a lattice pattern on the bottom member 5. Specifically, a plurality of ribs 7 (ribs 71, 72, 73, and 74) extending in the Y direction in FIG. 4 intersect with a plurality of ribs 7 (ribs 75, 76, and 77) extending in the X direction in FIG. 4 . However, the shape of the ribs 7 is not limited to that shown in FIG. 3 and may be any shape. For example, the ribs 7 may be curved instead of linear, and may not be arranged in a lattice pattern. The bottom member 5 may not have the ribs 7. In this case, the bottom member 5 is composed of only the plate portion 6.

[0029] In FIG. 3 , a fixed point P is formed on the main surface 5A of the bottom member 5 on the Z2-direction side. The fixed point P is a location on the bottom member 5 that serves as an interface for fixing the bottom member 5 to the vehicle (to the interior portion 10 in this embodiment), and in this embodiment, is a location where a bracket 9 (described later) is attached. The bottom member 5 is fixed to the bracket 9 with the main surface 5A in contact with the fixing member (here, the bracket 9). If the area of ​​the main surface 5A that contacts the fixing member is defined as the contact area, the fixed point P can be considered to be a point on the contact area. The fixed point P can be any position on the contact area. For example, in FIG. 1 , the fixed points P (fixed points P1 to P4) are illustrated as midpoints in the X direction of the sides of each contact area that are located on the Y2-direction side. In this way, the fixed point P can be the midpoint in the X direction of the sides of the contact area that are located on the Y2-direction side. It can be considered that one fixed point P is formed for each contact area. That is, when there are multiple fixing points P, it can be said that multiple contact areas are formed at separate positions, and one fixing point P is formed in each contact area. When there is one fixing point P, it can be said that there is also one contact area. For example, when the display device 1 (bottom member 5) is fixed to the bracket 9, the fixing point P may be a position on the main surface 5A that overlaps with the midpoint of one side of the end of the convex surface 9a of the bracket 9 (i.e., the midpoint in the X direction of the side on the Y2-direction side of the contact area). Furthermore, when the bottom member 5 is fixed to the bracket 9 with a fastener such as a bolt, the fixing point P may be a location on the main surface 5A where a hole (e.g., a bolt hole) through which the fastener is inserted is opened. When the bottom member 5 is fixed to the bracket 9 with multiple fasteners per contact area, the fixing point P may be a central position between the locations where the holes (e.g., bolt holes) through which the fasteners are inserted are opened. Furthermore, when the bottom member 5 is fixed to the bracket 9 with an adhesive or the like, the fixing point P may be a point on the main surface 5A on the contact area to which the adhesive is applied. In addition, for example, a protrusion may be formed on the main surface 5A of the bottom member 5, and the protrusion may be inserted into a recess formed in the vehicle (interior part 10 in this embodiment), thereby fixing the bottom member 5 to the vehicle. In this case, the protrusion of the bottom member 5 may be considered as the bracket 9, without providing a separate bracket 9.In this case, the surface of the bottom member 5 on the Z1-direction side of the protrusion becomes the contact area, and a point on the contact area may be the fixed point P. Alternatively, for example, a recess may be formed on the main surface 5A of the bottom member 5, and a protrusion formed on the vehicle (interior part 10 in this embodiment) may be inserted into the recess on the main surface 5A, thereby fixing the bottom member 5 to the vehicle. In this case, the protrusion on the vehicle may be considered to be the bracket 9, without providing a separate bracket 9. In this case, the surface of the bottom member 5 on the Z1-direction side of the recess becomes the contact area, and a point on the contact area may be the fixed point P. The position of the fixed point P will be described later.

[0030] The Young's modulus Ed of the bottom member 5 is preferably 1.5 GPa or more, more preferably 30 GPa or more, and even more preferably 40 GPa or more. The Young's modulus Ed of the bottom member 5 is preferably 250 GPa or less, more preferably 100 GPa or less, and even more preferably 80 GPa or less.

[0031] In addition, in the display device according to this embodiment, it is preferable that the above-mentioned cover member 2 is tempered glass having a compressive stress layer thickness of 10 μm or more, the Young's modulus Ecg of the cover member 2 is 60 GPa or more and 90 GPa or less, and the Young's modulus Ed of the bottom member 5 is 40 GPa or more and 250 GPa or less.

[0032] The material of the bottom member 5 is preferably a metal (single element) or an alloy containing a metal element such as aluminum or magnesium. The material of the bottom member 5 may also be a resin, or a laminate of a resin layer and a metal layer.

[0033] In the example of this embodiment, the bottom member 5 is disposed furthest in the direction Z1 among the members of the display device 1, but this is not limited thereto, and for example, another member may be provided on the Z1 side of the bottom member 5. In other words, even if another member is located on the Z1 side of the bottom member 5, the layer on which the fixed point P is formed (the bottom member 5) is treated as the bottom member in this embodiment. In other words, the layer on which the fixed point P is formed and which is furthest in the direction Z1 is treated as the bottom member 5.

[0034] (Surrounding Member) The surrounding member 8 is a frame-shaped member that surrounds the cover member 2, the display panel 3, and the backlight unit 4 when viewed from the Z direction, and can be said to be a side wall portion of the housing.

[0035] The surrounding member 8 includes a frame member and a sidewall member. The frame member is a frame-shaped portion surrounding the cover member 2 and is a portion of the surrounding member 8 that is closer to the Z1 direction than the second main surface 2B of the cover member 2. In other words, the frame member can be said to be adjacent to the outer side of the end surface 2C of the cover member 2. Here, "outside" refers to the radially outer side when the central axis of the cover member 2 aligned in the Z direction is defined as the axial direction, and the same applies hereinafter. Note that the central axis of the cover member 2 is an axis that passes through the center point of the cover member 2 when viewed from the Z direction and extends in the Z direction. On the other hand, the sidewall member is a portion that surrounds the display panel 3 (and the backlight unit 4) (a portion provided around the display panel 3) and is a portion of the surrounding member 8 that is closer to the Z2 direction than the second main surface 2B of the cover member 2.

[0036] As shown in FIG. 2 , in this embodiment, the peripheral member 8 includes a frame member 8a and sidewall members 8b and 8c. In this embodiment, the frame member 8a and the sidewall member 8b are integral. The sidewall member 8b is connected to the end of the frame member 8a on the Z2 side and protrudes inward from the frame member 8a. Here, the "inward" refers to the radially inner side when the central axis of the cover member 2 along the Z direction is the axial direction, and the same applies hereinafter. The sidewall member 8b supports the outer periphery of the second main surface 2B of the cover member 2 on the Z1 side of the region protruding inward from the frame member 8a. In this embodiment, although not shown, the sidewall member 8b and the cover member 2 are bonded via an adhesive layer. The sidewall member 8c is a frame-shaped member provided on the Z2 side of the sidewall member 8b. In this embodiment, the sidewall member 8c is arranged to surround the display panel 3 and the backlight unit 4. In this embodiment, the surface of the side wall member 8c facing the Z1 direction is adhered to the side wall member 8b via an adhesive layer.

[0037] The shapes of the surrounding members 8 (frame member and sidewall members) are not limited to those described above and may be any shape. For example, the frame member 8a and the sidewall members 8b may be separate members. Furthermore, for example, the sidewall members may be composed of a single member or three or more members.

[0038] The Young's modulus of the surrounding members 8 (frame member and sidewall member) is preferably 1 Pa or more and 250 GPa or less, and more preferably 40 GPa or more and 230 GPa or less. When the sidewall member or frame member is made up of multiple members, it is preferable that the Young's modulus of each member is within the above range.

[0039] The material of the surrounding member 8 (frame member and sidewall member) is preferably a metal (single element) or alloy containing a metal element such as aluminum or magnesium. The material of the surrounding member 8 (frame member and sidewall member) may be a resin or a laminate of a resin layer and a metal layer. When the surrounding member 8 (frame member and sidewall member) is composed of multiple members, each member may be made of a different material. For example, in the structure shown in FIG. 2 , the frame member 8 a and the sidewall member 8 b may be made of resin, and the sidewall member 8 c may be made of metal.

[0040] In this embodiment, the peripheral member 8 and the bottom member 5 may be separate members or may be integrated members. For example, some of the multiple members constituting the peripheral member 8 may be integrated with the bottom member 5, and other parts may be separate from the bottom member 5. Figure 2 illustrates an example of a configuration in which the side wall member 8c is integrated with the bottom member 5, and the frame member 8a and the side wall member 8b are separate from the bottom member 5.

[0041] (2. Fixed State of Display Device) Next, a state in which the display device 1 is fixed to the interior portion 10 of the vehicle will be described. Fixing of the display device 1 will be described below.

[0042] (Fixed Points) As described above, fixed points P that are fixed to the interior portion 10 are formed on the main surface 5A of the bottom member 5 of the display device 1 on the Z2 direction side. In this embodiment, multiple fixed points P are provided, and in the example of FIG. 1, four fixed points P1, P2, P3, and P4 are provided. Fixed points P1 and P2 are aligned in the X direction (the width direction of the vehicle when attached to the vehicle). Fixed points P3 and P4 are located on the Y2 direction side (vertically downward when attached to the vehicle) of fixed points P1 and P2, and are aligned in the X direction. A line passing through fixed points P1 and P2 and a line passing through fixed points P3 and P4 are parallel to each other, and fixed points P1 to P4 form the four vertices of a rectangle.

[0043] 1 to 3, brackets 9, which are fixing members, may be attached to the fixing points P. In this case, the bottom member 5 is fixed to the interior portion 10 via the brackets 9. In the example of this embodiment, bracket 91 is attached to fixing point P1, bracket 92 is attached to fixing point P2, bracket 93 is attached to fixing point P3, and bracket 94 is attached to fixing point P4.

[0044] As shown in FIG. 3 , the bracket 9 is a long, plate-like member bent into a U-shape. The center of the bracket 9 in the width direction is positioned at a fixed point P. One side of the end of a convex surface 9a (the surface on the Y2 side in FIG. 3 ) formed by the U-shape bend of the bracket 9 contacts the fixed point P. The direction perpendicular to the convex surface 9a of the bracket 9 intersects perpendicularly with the X direction (the width direction of the vehicle). One surface 9b of the bracket 9 connected to the convex surface 9a contacts the bottom member 5, and the other surface 9c connected to the convex surface 9a contacts the interior portion 10. That is, the fixed point P is located at a position on the main surface 5A of the bottom member 5 that overlaps with the midpoint of one side of the end of the convex surface 9a of the bracket 9 (i.e., the midpoint in the X direction of the side on the Y2 side of the contact area). The bracket 9 is fixed to the bottom member 5 and the interior portion 10, for example, with screws (not shown). The shape of the bracket 9 is not limited to the above description and may be any shape, for example, be bent into an S shape.

[0045] Because the display device 1 is attached to the vehicle via the bracket 9 in this way, it can be said that the display device 1 and the bracket 9 constitute a display device unit. Furthermore, the bottom member 5 may be fixed to the interior portion 10 without using the bracket 9, for example, by deforming a portion of the bottom member 5. Conversely, a portion of the interior portion 10 may be deformed and fixed to the bottom member 5. In this case, each fixing point P may be defined as the center of each fixing location.

[0046] The positions and number of fixed points P are not limited to those described above. Any number of fixed points P may be formed, and in that case, the positions of the fixed points P may also be arbitrary.

[0047] (Midpoint PQ) After that, the position of the fixed point P in the Y direction relative to the display device 1 (YH / YH ｃｇ In order to explain the above, an intermediate point PQ is defined. The intermediate point PQ is the midpoint between the fixed point P1 and the fixed point P2. If the distance between the intermediate point PQ and the fixed point P1 (or the distance between the intermediate point PQ and the fixed point P2) is defined as distance X, then from the viewpoint of vibration characteristics (JIS D 1601:1995 Automotive Parts Vibration Test Method), distance X is preferably 30 mm or more and 200 mm or less, and more preferably 50 mm or more and 130 mm or less. Furthermore, if the distance between the fixed point P1 and the fixed point P3 (or the distance between the fixed point P2 and the fixed point P4) arranged in the Y direction is defined as distance Y, then distance Y is, for the same reason, preferably 30 mm or more and 200 mm or less, and more preferably 35 mm or more and 125 mm or less.

[0048] As described above, the number and positions of the fixed points P are arbitrary, so the definition of the intermediate points PQ for each variation in the position of the fixed points P will be described below.

[0049] Of the fixed points P provided on the bottom member 5, two fixed points P are selected from the Y1 direction side (vertically upward), and the midpoint between the two selected fixed points P is defined as the intermediate point PQ. For example, FIGS. 1 to 3 show an embodiment in which the bottom member 5 is fixed to the interior portion 10 at four fixed points P (fixed points P1 to P4) arranged in pairs in the Y direction. As shown in FIGS. 1 to 3, when there are multiple fixed points P in the Y direction, the two fixed points furthest in the Y1 direction (fixed points P1 and P2 in FIG. 1) are used as the fixed points P for defining the intermediate point PQ (and thus the virtual plane R, which will be described later).

[0050] When three or more fixed points P exist at the same position (same height) in the Y direction, two fixed points P with the smallest distance between them are selected, and the midpoint between them is set as the intermediate point PQ. When three or more fixed points exist at the same position in the Y direction and at equal intervals, the midpoint between any two fixed points P may be set as the intermediate point PQ. In other words, when there are multiple candidates for the intermediate point PQ (and thus the virtual plane R described below), it is sufficient that any one of them satisfies the requirements of this embodiment.

[0051] The bottom member 5 may be fixed to the interior portion 10 at three fixed points P. For example, referring to FIG. 1 , it is assumed that there are no fixed points P1 and P2, and instead, another fixed point P' (not shown in FIG. 1 ) exists on the line connecting fixed points P1 and P2. In this case, the bottom member 5 is fixed to the interior portion 10 at three points: fixed points P3, P4, and P'. In this case, if there is no difference in position (height) between fixed points P3 and P4 in the Y direction, the fixed point closer to fixed point P' is selected, and the midpoint between the selected fixed point and fixed point P' is designated as midpoint PQ. If there is no difference in distance from fixed point P', any one of the fixed points is selected, and the midpoint between the selected fixed point and fixed point P' is designated as midpoint PQ. Furthermore, if fixed points P3 and P4 are at different positions in the Y direction, as in the specification for four fixed points P, two fixed points P (fixed point P' and the fixed point between fixed points P3 and P4 on the direction Y1 side) are selected from the direction Y1 side, and the midpoint between the selected fixed points is set as the intermediate point PQ.

[0052] (YH / YH ｃｇ3, a plane that passes through the midpoint PQ and is perpendicular to the line connecting the fixed points P1 and P2 (the two fixed points P used to define the midpoint PQ) is defined as a virtual plane R. Also, as shown in FIG. 3, the length of the intersection line between the cover member 2 and the virtual plane R is defined as a distance YH. ｃｇ 3 , the length of the intersection line between the main surface of the display panel 3 and the imaginary plane R from the upper end (the end on the Y1 direction side) of the display panel 3 to a point corresponding to the midpoint PQ is defined as a distance YH. Note that the "point corresponding to the midpoint PQ" is a point located on the main surface of the display panel 3 by moving the midpoint PQ in the thickness direction (Z direction) of the display device 1.

[0053] The display device 1 detects the distance YH and the distance YH ｃｇ The ratio YH / YH ｃｇ It is preferable that the position of the fixed point P is set so that the ratio YH / YH is 0.5 or less. In other words, it can be said that the display device 1 is preferably an "in-dash type or on-dash type (hereinafter also simply referred to as "in-dash type") display device in which the vicinity of the upper end is also fixed to the interior part 10. The display device 1 is ｃｇ is more preferably 0.1 or more and 0.5 or less, and further preferably 0.3 or more and 0.5 or less. ｃｇ If the ratio is greater than 0.5, it can be said that the seat is of the "standing type" in which only the lower end of the base member is fixed to the dashboard.

[0054] That is, the bottom member 5 according to this embodiment has a plate portion 6 and a rib 7 protruding from a main surface of the plate portion 6 on the opposite side to the first orientation (the Z2 direction side), and at least two fixing points P that are fixed to the vehicle are formed on the main surface on the opposite side to the first orientation (the Z2 direction side), and an imaginary plane R passes through a midpoint PQ between the two fixing points P and is perpendicular to a line connecting the two fixing points P, and the length of the intersection line between the main surface of the cover member 2 and the imaginary plane R is a distance YH. ｃｇ and the distance YH is the length from the upper end to the point corresponding to the midpoint PQ of the intersection line between the main surface of the display layer (display panel 3) and the imaginary plane R. ｃｇ The ratio YH / YH ｃｇ is preferably 0.5 or less.

[0055] The display device 1 is fixed to the vehicle in the above manner.

[0056] (3. Structure for Suppressing Cracks in the Cover Member) The cover member 2 according to this embodiment has a thickness tcg of 0.3 mm or more and 0.7 mm or less, making it relatively thin. As a result of extensive research, the inventors have found that a cover member 2 of this thickness deforms differently when subjected to an impact compared to a cover member with a greater thickness. The inventors have also found that by setting the parameter T, which will be described later, within an appropriate range, cracks in a cover member 2 of this thickness can be suppressed. A structure for suppressing cracks in the cover member 2 will be described below. FIG. 5 is a partially enlarged view of a cross section of a display device according to this embodiment. FIG. 5 is a partially enlarged view of the B-B cross section of FIG. 1. The B-B cross section refers to a cross section perpendicular to the X direction at the position of a reference point H (described later) in the X direction.

[0057] (Parameter A) The parameter A for defining the parameter T is set to a value shown in the following equation (1).

[0058] A = Ecg x tcg ２ ...(1)

[0059] In the formula (1), Ecg is the Young's modulus (GPa) of the cover member 2, and tcg is the thickness (mm) of the cover member 2. That is, the parameter A is a parameter indicating the rigidity of the cover member 2.

[0060] (Parameter B) The parameter B for defining the parameter T is set to a value shown in the following equation (2).

[0061] B = Σ(Eb × tb ２ ) ... (2)

[0062] In Equation (2), Eb is the Young's modulus (GPa) of the sidewall member. tb is the thickness (mm) of the portion of the sidewall member that protrudes outward from the end face 2C of the cover member 2. When the sidewall member is made of two or more materials, parameter B is a parameter that indicates the sum of the rigidity of each portion of each material that protrudes outward from the end face 2C of the cover member 2 (i.e., the product of the "Young's modulus" of each portion and the "square of the thickness" of each portion). If the sidewall member is made of two or more materials and the thickness of the portion that protrudes outward from the end face 2C of each material is not uniform, the thickness tb of the sidewall member at a point 0.5 mm outward from the end face 2C may be used. In the example of FIG. 5 , a portion of sidewall member 8b and a portion of sidewall member 8c protrude outward from the end face 2C of the cover member 2. Therefore, if the thickness of the portion of the side wall member 8b that protrudes outward from the end surface 2C is taken as tb1, the Young's modulus of the side wall member 8b is taken as Eb1, the thickness of the portion of the side wall member 8c that protrudes outward from the end surface 2C is taken as tb2, and the Young's modulus of the side wall member 8c is taken as Eb2, then the parameter B is given by (Eb1×tb1 ２ ) + (Eb2 × tb2 ２ ) The value of parameter B is preferably greater than 0. By setting the value of parameter B within this range, cracking of the cover member 2 can be suitably suppressed.

[0063] (Parameter C) The parameter C for defining the parameter T is set to a value shown in the following equation (3).

[0064] C=Σ(Eb×tc)...(3)

[0065] In equation (3), tc is the protrusion length (mm) of the portion of the sidewall member protruding outward from the end surface 2C of the cover member 2. When the sidewall member is made of two or more materials, parameter C is a parameter that indicates the sum of the rigidity of each portion of each material protruding outward from the end surface 2C of the cover member 2 (i.e., the product of the "Young's modulus" and the "protrusion length" of each portion). In the example of FIG. 5 , the protrusion length tc is the distance in the X direction between the outer surface of the portion of the sidewall member protruding outward from the end surface 2C of the cover member 2 and the end surface 2C. Note that if the protrusion length of the portion protruding outward from the end surface 2C is not uniform, the average protrusion length for each position may be used as the protrusion length tc. In the example of FIG. 5 , a portion of the sidewall member 8b and a portion of the sidewall member 8c protrude outward from the end surface 2C of the cover member 2. Therefore, if the protrusion length of the portion of sidewall member 8b protruding outward from end face 2C is protrusion length tc1, the Young's modulus of sidewall member 8b is Eb1, the protrusion length of the portion of sidewall member 8c protruding outward from end face 2C is protrusion length tc2, and the Young's modulus of sidewall member 8c is Eb2, then parameter C is (Eb1 x tc1) + (Eb2 x tc2). It is preferable that protrusion length tc is greater than 0 mm. In other words, it is preferable that display device 1 has a sidewall portion that includes a portion that protrudes outward from end face 2C of cover member 2.

[0066] (Parameter D) The parameter D for defining the parameter T is set to a value shown in the following equation (4).

[0067] D = Ed × td ２ ...(4)

[0068] In Equation (4), Ed is the Young's modulus (GPa) of the bottom member 5, and td is the thickness (mm) of the bottom member 5. That is, parameter D is a parameter indicating the rigidity of the bottom member 5. Here, the thickness td of the bottom member 5 refers to the thickness of the bottom member 5 in a region (overlapping region) of the bottom member 5 that overlaps with the cover member 2 when viewed from the Z direction. Parameter D is preferably 50 to 700, more preferably 70 to 500. Setting the lower limit of parameter D within this range enables appropriate fixation to the vehicle, and setting the upper limit within this range enables impact absorption and appropriate suppression of cracking of the cover member 2. More specifically, in this embodiment, thickness td refers to the thickness of the bottom member 5 at a position M, within the overlapping region of the bottom member 5, that is 10 mm inward from the position where the bottom member 5 overlaps with the edge surface of the display panel 3 when viewed from the Z direction. However, for example, if the bottom member 5 at position M has local unevenness and the thickness is locally larger or smaller (for example, if the thickness at position M deviates from the average thickness in the overlapping region of the bottom member 5 by more than 50% of the average thickness), a relatively flat location within 50 mm around position M that avoids local unevenness can be used as position M', and the thickness at position M' can be used as thickness td.

[0069] Furthermore, when the bottom member 5 is provided with a rib 7 within 100 mm of the position M or the position M′, the thickness td may be set to the value shown in the following formula (A): Figure 6 is a schematic partial enlarged view of the bottom member provided with a rib.

[0070]

[0071] In formula (A), a is the thickness (mm) of the plate portion 6 of the bottom member 5 in the Z direction as shown in FIG. 6, and w ２ is the width (mm) of the first rib Rb1 as shown in FIG. 6, and w １As shown in FIG. 6 , π is the distance (mm) between the first rib Rb1 and the second rib Rb2, and h is the thickness (mm) of the first rib Rb1 and the second rib Rb2 in the Z direction, as shown in FIG. 6 . The first rib Rb1 is the rib 7 of the bottom member 5 that is closest to position M (or position M'). The second rib Rb2 is the rib 7 that is located on a line connecting position M (or position M') and the first rib Rb1 and that is closest to the first rib Rb1. In other words, the second rib Rb2 is the rib that is located in the direction of a line that passes through position M (or position M') and the first rib Rb1 and is perpendicular to the center line of the first rib Rb1. The width of the first rib Rb1 refers to the width of the first rib Rb1 when viewed from the direction in which the first rib Rb1 extends. The distance between the first rib Rb1 and the second rib Rb2 refers to the distance between the central axis of the first rib Rb1 and the central axis of the second rib Rb2 when viewed from the extension direction of the first rib Rb1. Furthermore, the distance between the first rib Rb1 and the second rib Rb2 can be said to be the distance (the distance between the center lines) between the first rib Rb1 (rib 73) and the second rib Rb2 (rib 75) on a perpendicular line to the first rib Rb1 (rib 73) that passes through point p. Furthermore, if the thicknesses of the first rib Rb1 and the second rib Rb2 in the Z direction are different, h may be the average value of the thicknesses of the first rib Rb1 and the second rib Rb2 in the Z direction.

[0072] In formula (A), b is represented by the following formula (B).

[0073]

[0074] The thickness td of the bottom member 5 thus defined is preferably 0.5 mm to 5 mm, more preferably 1 mm to 4 mm, and even more preferably 1 mm to 3 mm. By setting the lower limit of the thickness td within this range, the cover member 2 can be properly fixed to the vehicle, and by setting the upper limit within this range, impact can be absorbed and cracking of the cover member 2 can be properly suppressed.

[0075] (Reference Point H) The reference point H, which is the reference position of the BB cross section, will be described.

[0076] 1 , on a corner 2D (boundary between the first main surface 2A and the end surface 2C) on the Y1-direction side of the cover member 2, a position that is equidistant from each of the two fixed points P used to define the midpoint PQ as viewed from the Z direction is defined as an equidistant point H0. In the example of this embodiment, fixed points P1 and P2 are used to define the midpoint PQ, so the equidistant point H0 can be said to be a point on the corner 2D on the Y-direction side of the cover member 2 that is equidistant from fixed point P1 and from fixed point P2 as viewed from the Z direction. That is, in the example of this embodiment, the distance from the equidistant point H0 to the fixed point P1 as viewed from the Z direction is equal to the distance from the equidistant point H0 to the fixed point P2 as viewed from the Z direction.

[0077] Furthermore, positions on the corner 2D that are a predetermined distance D1 away from the equidistant point H0 in the extension direction of the corner 2D on the Y direction side of the cover member 2 (the X direction in the example of FIG. 1 ) are defined as points H1 and H2. That is, in the example of FIG. 1 , the position on the corner 2D that is the predetermined distance D1 away from the equidistant point H0 in the direction X2 is point H1, and the position on the corner 2D that is the predetermined distance D1 away from the equidistant point H0 in the direction X1 is point H2. In this case, any position between points H1 and H2 on the corner 2D on the Y direction side of the cover member 2 is defined as the reference point H. The predetermined distance D1 here may be set arbitrarily and may be, for example, 18 mm.

[0078] The reference point H may be any position between points H1 and H2 on the corner 2D on the Y-direction side, but is preferably set to the position between points H1 and H2 on the corner 2D on the Y-direction side where the rigidity is minimum. In the example of this embodiment, the position between points H1 and H2 where the rigidity is minimum is the equidistant point H0, and therefore the equidistant point H0 is treated as the reference point H. However, the reference point H is not limited to the position between points H1 and H2 where the rigidity is minimum. For example, the equidistant point H0 may be treated as the reference point H without considering the rigidity. Note that the reference point H may be, for example, the impact point where the impactor is struck in a head impact test.

[0079] 2, a virtual line V is defined as a virtual line that passes through the reference point H and the bottom member 5 and is inclined at an angle θ with respect to the Z direction. In other words, the virtual line V can be said to be a line that passes through the reference point H and is inclined inward at an angle θ with respect to the Z direction. In this embodiment, the angle θ is equal to or greater than 30° and equal to or less than 45°. The virtual line V can be said to correspond to the direction in which a high impact is transmitted when an impact is applied to the corner 2D, such as in a head impact test.

[0080] (Parameter T) Next, a description will be given of the parameter T. The parameter T is set to a value shown in the following equation (5).

[0081] T=0.212245+A(-0.00997+0.000124×B+0.0000362×C-0.000022×D-0.00809×G)-0.00817×B-0.00183×C+0.001722×D+0.957752×G...(5)

[0082] As shown in FIG. 5 , G in formula (5) is the protrusion length (mm) of the first main surface 2A of the cover member 2 toward the Z1 direction from the surface 8aA on the Z1 side of the frame member 8a. For example, if the first main surface 2A protrudes 2 mm toward the Z1 direction from the surface 8aA, the protrusion length G is +2 mm. If the surface 8aA protrudes 2 mm toward the Z1 direction from the first main surface 2A, the protrusion length G is −2 mm. FIG. 5 also illustrates a configuration example in which the first main surface 2A protrudes toward the Z1 direction from the surface 8aA. FIG. 5 also illustrates a configuration example in which an adhesive layer 2E is provided on the second main surface 2B of the cover member 2, bonding the second main surface 2B to the side wall member 8b and the display panel 3.

[0083] The parameter T defined as above is less than 0, preferably -0.1 or less, and more preferably -0.2 or less. The present inventors have discovered that when an impact is applied to the corner 2D in a direction along the imaginary line V (e.g., in a head impact test), strong tensile stress occurs on the display side (first main surface 2A side) of the cover member 2, slightly inside the end surface 2C. In response to this, the present inventors have discovered that by setting the parameter T within the above range, it is possible to prevent the tensile stress from increasing and suppress cracking of the cover member 2, even in such cases. In other words, by designing the display device 1 so that the parameter T is within the above range, cracking of the cover member 2 can be suppressed.

[0084] (Parameter T1) The parameter T1 is set to a value shown in the following equation (6).

[0085] T1=0.7416-0.01455×B-0.01685×A+0.000244×A×B...(6)

[0086] The parameter T1 is preferably less than 0, more preferably equal to or less than −0.1, and even more preferably equal to or less than −0.2. When the parameter T1 is in this range, cracking of the cover member 2 can be more suitably suppressed. In other words, by increasing the parameter B, the cover member 2 can be appropriately protected by the side wall member and stress on the cover member 2 can be reduced, thereby more suitably suppressing cracking of the cover member 2.

[0087] Here, parameter B is preferably greater than 0, more preferably equal to or greater than 15, preferably equal to or greater than 50, and even more preferably equal to or greater than 70. When parameter B is in the above range, the rigidity of the side wall member is increased, deformation of the cover member when an impact is applied to corner portion 2D is suppressed, and the generation of tensile stress can be reduced.

[0088] (Parameter T2) The parameter T2 is set to a value shown in the following equation (7).

[0089] T2=0.313919-0.0045×C-0.01057×A-0.0000791×A×C...(7)

[0090] The parameter T2 is preferably less than 0, more preferably equal to or less than −0.1, and even more preferably equal to or less than −0.2. When the parameter T2 is in this range, cracking of the cover member 2 can be more suitably suppressed. In other words, by increasing the parameter C, the cover member 2 can be appropriately protected by the side wall member and stress on the cover member 2 can be reduced, thereby more suitably suppressing cracking of the cover member 2.

[0091] (Parameter T3) The parameter T3 is set to a value shown in the following equation (8).

[0092] T3=0.079709+0.001749×D-0.00791×A-0.000023×A×D...(8)

[0093] Parameter T3 is preferably less than 0, more preferably equal to or less than −0.1, and even more preferably equal to or less than −0.2. When parameter T3 is in this range, cracking of cover member 2 can be more suitably suppressed. In other words, by lowering parameter D, impact can be appropriately absorbed by bottom member 5, reducing stress on cover member 2, and therefore cracking of cover member 2 can be more suitably suppressed.

[0094] (Parameter T4) The parameter T4 is set to a value shown in the following equation (9).

[0095] T4=-0.40013+1.736071×G+0.00185×A-0.01998×G×A...(9)

[0096] Parameter T4 is preferably less than 0, more preferably equal to or less than −0.1, and even more preferably equal to or less than −0.2. When parameter T4 is in this range, cracking of the cover member 2 can be more suitably suppressed. In other words, by reducing the protruding length of the cover member 2, stress on the cover member 2 can be reduced, and therefore cracking of the cover member 2 can be more suitably suppressed.

[0097] In this embodiment, it is preferable that at least one of the parameters T1, T2, T3, and T4 be within the above range (for example, less than 0), but it is more preferable that at least the parameter T1 be within the above range, and it is even more preferable that all of the parameters T1, T2, T3, and T4 be within the above range.

[0098] (Protrusion Length G) For reasons of design of the display device 1, the protrusion length G is preferably -0.7 mm or more and 3 mm or less, more preferably -0.55 mm or more and 2 mm or less, and even more preferably -0.55 mm or more and 1 mm or less. Even if the protrusion length G is relatively small like this, cracking of the cover member 2 can be suppressed by setting the parameter T in the above range. Furthermore, when the protrusion length G is in the above range, it is more preferable that the parameter T1 be 0.38 or less. This makes it possible to suitably suppress cracking of the cover member 2 even if the protrusion length G is relatively small like this.

[0099] (Effects) As described above, the display device 1 according to the first aspect of the present disclosure includes a bottom member 5, a display panel 3 (display layer) provided on the bottom member 5, sidewall members provided around the display panel 3, and a glass cover member 2 provided on the display panel 3 and the sidewall members and having a thickness tcg of 0.3 mm to 0.7 mm. In the thickness direction (Z direction) of the cover member 2, if the direction from the bottom member 5 toward the cover member 2 is defined as a first orientation (orientation Z1), the cover member 2 has a first main surface 2A on the first orientation side, a second main surface 2B opposite to the first main surface 2A, and an end surface 2C connecting the first main surface 2A and the second main surface 2B, and the parameter T is less than 0. According to the present disclosure, cracking of a cover member 2 having such a thickness can be suitably suppressed.

[0100] A display device 1 according to a second aspect of the present disclosure is the display device according to the first aspect, wherein the cover member 2 is made of tempered glass having a compressive stress layer with a thickness of 10 μm or more, the cover member 2 preferably has a Young's modulus Ecg of 60 GPa or more and 90 GPa or less, and the bottom member 5 preferably has a Young's modulus Ed of 40 GPa or more and 250 GPa or less. According to the present disclosure, cracking of the cover member 2 can be suitably suppressed.

[0101] A display device 1 according to a third aspect of the present disclosure is the display device according to the first or second aspect, and preferably has a protrusion length tc of the side wall member greater than 0 mm. According to the present disclosure, the side wall portion includes a portion that protrudes outward from the end surface 2C of the cover member 2, thereby making it possible to suitably suppress cracking of the cover member 2.

[0102] The display device 1 according to the fourth aspect of the present disclosure is the display device according to any one of the first to third aspects, and preferably has parameter B greater than 0. By setting parameter B in this range, cracking of the cover member 2 can be suitably suppressed.

[0103] The display device 1 according to a fifth aspect of the present disclosure is the display device according to any one of the first to fourth aspects, and preferably has the parameter T1 less than 0. By setting the parameter T1 in this range, cracking of the cover member 2 can be suitably suppressed.

[0104] A display device 1 according to a sixth aspect of the present disclosure is the display device according to any one of the first to fifth aspects, and preferably has a protruding length G of −0.7 mm or more and 3 mm or less of the first main surface 2A of the cover member 2. By setting the protruding length G within this range, cracks in the cover member 2 can be suitably suppressed while being preferable from a design perspective.

[0105] A display device 1 according to a seventh aspect of the present disclosure is the display device according to any one of the first to sixth aspects, and preferably has a thickness td of 0.5 mm to 5 mm of the bottom member 5. By setting the thickness of the bottom member 5 within this range, cracking of the cover member 2 can be suitably suppressed and the housing 1A can be appropriately fixed.

[0106] The display device 1 according to an eighth aspect of the present disclosure is the display device according to any one of the first to seventh aspects, and preferably has a parameter D of not less than 50 and not more than 700. By setting the parameter D in this range, cracking of the cover member 2 can be suitably suppressed.

[0107] A display device 1 according to a ninth aspect of the present disclosure is the display device according to any one of the first to eighth aspects, wherein the bottom member 5 has a plate portion 6 and a rib 7 protruding from a main surface of the plate portion 6 on the Z2 direction side, at least two fixing points P that are fixed to a vehicle are formed on the main surface on the Z2 direction side, an imaginary plane R passes through the midpoint between the two fixing points P and is perpendicular to a line connecting the two fixing points P, and a length of an intersection line between the main surface of the cover member 2 and the imaginary plane R is a distance YH ｃｇ and the distance YH is the length from the top end to the point corresponding to the midpoint of the intersection line between the main surface of the display panel 3 and the imaginary plane R. ｃｇ The ratio YH / YH ｃｇ is 0.5 or less. That is, the display device 1 is preferably an in-dash type. According to the present disclosure, in the in-dash type display device 1, cracking of the cover member 2 can be appropriately suppressed.

[0108] A display device 1 according to a tenth aspect of the present disclosure is the display device according to any one of the first to ninth aspects, and preferably has a parameter T of −0.1 or less. By setting the parameter T in this range, cracking of the cover member 2 can be more suitably suppressed.

[0109] A display device 1 according to an eleventh aspect of the present disclosure is the display device according to any one of the first to tenth aspects, and preferably has a parameter T of −0.2 or less. By setting the parameter T in this range, cracking of the cover member 2 can be further preferably suppressed.

[0110] (Example) Next, an example will be described. Note that the embodiment may be modified as long as the effects of the invention are achieved.

[0111] In the examples, a simulation model of the display device 1 was generated, and a simulation was performed in which an impact was applied to the simulation model of the display device 1 at a reference point H, thereby simulating a head impact test. The models of each example are described below. Tables 1 to 4 are tables that explain each example.

[0112]

[0113]

[0114]

[0115]

[0116] Example 1 In Example 1, a model of a display device was prepared, which had a cover member, a display panel 3, a side wall member, and a bottom member. That is, the model of the display device 1 employed the structure described with reference to FIGS.

[0117] In the model of display device 1 of Example 1, the size of the cover member was 250 mm in the X direction, 150 mm in the Y direction, and 0.4 mm in the Z direction (thickness tcg: 0.4 mm), the thickness of the compressive stress layer was 20 μm, and the Young's modulus Ecg was 74 GPa. In the model of display device 1, the size of the display panel 3 was 170 mm in the X direction, 125 mm in the Y direction, and 1.1 mm in the Z direction. Furthermore, the distance S1 between the Y-direction end of the cover member and the Y-direction end of the display panel 3 was 12.5 mm, and the distance S2 between the X-direction end of the cover member and the X-direction end of the display panel 3 was 40 mm. Furthermore, the thickness tb1 of the sidewall member (sidewall member 1 in Table 1) was 2 mm, the protrusion length tc1 outward from the end face of the cover member was 2.35 mm, and the Young's modulus Eb1 was 2.5 GPa. The bottom member had the same dimensions in the X and Y directions as the cover member, a thickness td of 2 mm, and a Young's modulus Ed of 70 GPa. A frame member was also provided to surround the cover member so as to be integrated with the sidewall member (sidewall member 1 in Table 1). The protrusion length G of the first main surface on the Z1 side of the cover member from the surface on the Z1 side of the frame member toward the Z1 side was set to 0 mm. In other words, the surface on the Z1 side of the frame member and the first main surface on the Z1 side of the cover member were flush with each other. Furthermore, in the display device model, the ratio YH / YH ｃｇThe bracket was positioned with a fixed point P set so that the θ was 0.5. The position of each fixed point in the X direction was the center between the X direction end of the cover member and the X direction end of the display panel. The reference point H was set on the corner of the cover member on the Y1 direction side, at a position equidistant from the fixed points P1 and P2. Furthermore, as shown in Table 1, the parameters T, T1, T2, T3, and T4 were calculated using equations (5) to (9).

[0118] (Examples 2 to 51) In Examples 2 to 51, as shown in Tables 1 to 4, models were generated by changing at least one of the thickness tcg of the cover member, Young's modulus Ecg, thickness tb1 of the sidewall member, protrusion length tc1, presence or absence of a second sidewall member (sidewall member 2 in Table 1), thickness td of the bottom member, Young's modulus Ed, and protrusion length G of the cover member. The thickness of the compressive stress layer was set to 20 μm. The second sidewall member (sidewall member 2 in Table 1) is the sidewall member located on the Z2 side of the first sidewall member (sidewall member 1 in Table 1). That is, the first sidewall member (sidewall member 1 in Table 1) corresponds to sidewall member 8b shown in FIG. 5, and the second sidewall member (sidewall member 2 in Table 1) corresponds to sidewall member 8c shown in FIG. 5.

[0119] (Evaluation) A simulation was performed in which an impactor was collided with the reference point H of the model generated in each example under the following conditions: Impactor collision energy: 97 (J) Impactor weight: 6.8 (kg) Impactor diameter: 165 (mm) Impactor collision angle (inclination angle of the impactor collision direction relative to the Z direction): 55 (°)

[0120] (Evaluation Results) Analysis results of the stress generated in the glass article when the impactor was struck at reference point H were obtained by simulation. If the maximum stress generated in the glass article was 95% or less of the threshold for cracking, it was rated A, if it was greater than 95% but less than 100%, it was rated B, and if it was 100% or more, it was rated C. A and B were rated as pass, and C was rated as fail.

[0121] As shown in Tables 1 to 4, Examples 6 to 15, 18, and 22 to 45, which are working examples in which the parameter T is less than 0, received pass evaluation results, indicating that cracking could be suppressed. On the other hand, Examples 1 to 5, 16 to 17, 19 to 21, and 46 to 51, which are comparative examples in which the parameter T is 0 or greater, received fail evaluation results, indicating that cracking could not be suppressed.

[0122] Although the embodiments of the present invention have been described above, the embodiments are not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the scope of what is called equivalents. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments.

[0123] According to the present invention, it is possible to provide a display device that can suppress cracking of the cover member.

[0124] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2023-123718) filed on July 28, 2023, the contents of which are incorporated herein by reference.

[0125] REFERENCE SIGNS LIST 1 display device 1A housing 2 cover member 2A first main surface 2B second main surface 2C end surface 3 display panel 4 backlight unit 5 bottom member 6 plate portion 7 rib 8 surrounding member 8a frame member 8b, 8c side wall member 9 bracket 10 interior portion

Claims

1. A display device having a bottom member, a display layer provided on the bottom member, a sidewall member provided around the display layer, and a glass cover member provided on the display layer and the sidewall member and having a thickness of 0.3 mm to 0.7 mm, wherein, in the thickness direction of the cover member, a direction from the bottom member toward the cover member is defined as a first direction, the cover member has a first main surface on the first direction side, a second main surface opposite to the first main surface, and an end surface connecting the first main surface and the second main surface, and wherein, when parameter A is a value shown in the following formula (1), parameter B is a value shown in the following formula (2), parameter C is a value shown in the following formula (3), parameter D is a value shown in the following formula (4), and parameter T is a value shown in the following formula (5), the parameter T is less than 0. A=Ecg×tcg ２ ...(1) B=Σ(Eb×tb ２ ) ...(2) C=Σ(Eb×tc) ...(3) D=Ed×td ２ ... (4) T = 0.212245 + A (-0.00997 + 0.000124 x B + 0.0000362 x C - 0.000022 x D - 0.00809 x G) - 0.00817 x B - 0.00183 x C + 0.001722 x D + 0.957752 x G ... (5) where, Ecg is the Young's modulus (GPa) of the cover member, tcg is the thickness (mm) of the cover member, Eb is the Young's modulus (GPa) of the side wall member, tb is the thickness (mm) of a portion of the side wall member that protrudes outward from the end face of the cover member, tc is the protrusion length (mm) of the portion of the side wall member that protrudes outward from the end face of the cover member, Ed is the Young's modulus (GPa) of the bottom member, td is the thickness (mm) of the bottom member, and G is the protruding length (mm) of the first main surface of the cover member in the first direction from the first-facing surface of the frame member that is adjacent to the outside of the end face of the cover member.

2. The display device according to claim 1, wherein the cover member is made of tempered glass having a compressive stress layer having a thickness of 10 μm or more, the cover member has a Young's modulus Ecg of 60 GPa or more and 90 GPa or less, and the bottom member has a Young's modulus Ed of 40 GPa or more and 250 GPa or less.

3. The display device according to claim 1 or 2, wherein the protruding length tc of the side wall member is greater than 0 mm.

4. The display device according to claim 1 or 2, wherein the value of the parameter B is greater than 0.

5. The display device according to claim 1 or 2, wherein a parameter T1 shown in the following formula (6) is less than 0. T1=0.7416-0.01455×B-0.01685×A+0.000244×A×B (6) 6. The display device according to claim 1 or 2, wherein a protruding length G of said first main surface of said cover member is not less than −0.7 mm and not more than 3 mm.

7. The display device according to claim 1 or 2, wherein the thickness td of the bottom member is 0.5 mm or more and 5 mm or less.

8. The display device according to claim 1 or 2, wherein the value of the parameter D is 50 or more and 700 or less.

9. The bottom member has a plate portion and a rib protruding from a main surface of the plate portion opposite to the first direction, and at least two fixing points fixed to a vehicle are formed on the main surface opposite to the first direction. A virtual plane R passes through the midpoint between the two fixing points and is perpendicular to a line connecting the two fixing points. The length of the intersection line between the main surface of the cover member and the virtual plane R is a distance YH. ｃｇ and the length from the upper end to the point corresponding to the midpoint of the line of intersection between the main surface of the display layer and the imaginary surface R is a distance YH, the distance YH and the distance YH ｃｇ Ratio to YH / YH ｃｇ The display device according to claim 1 , wherein the ratio of the pixel pitch to the pixel pitch is 0.5 or less.

10. The display device according to claim 1 or 2, wherein the parameter T is equal to or less than −0.

1.

11. The display device according to claim 1 or 2, wherein the parameter T is equal to or less than −0.2.

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