KR20170048249A - On-board display apparatus - Google Patents

Abstract

A vehicle-mounted display device having excellent impact resistance of a cover glass.
Wherein the cover glass has a thickness of 0.5 to 2.5 mm and a thickness of the surface compressive stress layer of 10 m or less, Or more, and satisfies a specific formula (I).

Description

[0001] ON-BOARD DISPLAY APPARATUS [0002]

The present invention relates to a vehicle-mounted display device.

BACKGROUND ART Conventionally, in order to protect a display panel such as a liquid crystal panel, a transparent protective member covering a display surface (display area) of the display panel is used. As a protective member for protecting the display device as described above, for example, Patent Document 1 discloses an adhesive layer-forming transparent face material having an adhesive layer formed on its surface.

International Publication No. 2011/148990

Vehicles such as automobiles are equipped with on-vehicle display devices such as car navigation systems. The types of on-vehicle display devices include, for example, an on-dash type formed on the outside of a dashboard, a dash type embedded in a dashboard, and the like.

Also in such a vehicle-mounted display device, a transparent protective member such as a film or glass is used from the viewpoint of protecting the display panel. In recent years, from the viewpoint of texture, the use of a protective member (cover glass) . Among the glass, the lumber glass tends to be thicker, which tends to cause problems in design and is also expensive, and therefore, the use of tempered glass is demanded.

From the viewpoint of safety, the cover glass for a vehicle display device is required to have excellent impact resistance such that the head portion of a passenger does not crack even when a collision accident occurs in a vehicle. However, the shock caused by the collision is significantly higher in energy than the shock which is assumed in a stationary display device such as a liquid crystal television, for example, and thus a high impact resistance is required for the cover glass.

The present invention has been made in view of the above points, and an object thereof is to provide a vehicle-mounted display device having excellent impact resistance of a cover glass.

An on-vehicle display device according to an embodiment of the present invention is a in-vehicle display device in which a cover glass in a surface layer is a first layer and members up to the nth layer are laminated, wherein the cover glass has a thickness of 0.5 to 2.5 mm And the surface compressive stress layer has a thickness of 10 탆 or more, and the on-vehicle display device is a on-vehicle display device satisfying the following formula (I).

Equation (I) ... P? 0.0302t ₁ ² + 0.0039t ₁ + 0.0478

(In this formula, (Ⅰ) _{of, P = E 1 / (E} 1 t 1 2 + ... + E n t n 2), E 1: Young's modulus of the cover glass (unit: ㎬), t _1: thickness of the cover glass (Unit: mm), E _n is the Young's modulus of the member of the n-th layer (unit: mm), t _n is the thickness of the n-th layer (unit: mm), and n is an integer of 2 or more)

According to the present invention, it is possible to provide a vehicle-mounted display device having excellent impact resistance of a cover glass.

1 is a schematic cross-sectional view showing a cover glass on which an adhesive layer is formed.
2 is a schematic cross-sectional view showing the on-vehicle display device.
3 is a schematic diagram showing a four-layer structure.
4 is a perspective view showing the test body.
5 is a sectional view taken along line AA in Fig.
6 is a plan view showing a test body.
7 is a graph plotting the evaluation results of the impact resistance.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and substitutions may be made to the following embodiments without departing from the scope of the present invention. Can be added.

Hereinafter, first, a cover glass on which an adhesive layer for use in the in-vehicle display device of the present embodiment is formed will be described, and then the in-vehicle display device of the present embodiment will be described.

[Cover glass on which an adhesive layer is formed]

1 is a schematic cross-sectional view showing a cover glass on which an adhesive layer is formed. In this embodiment, as a method of manufacturing a vehicle-mounted display device, a cover glass on which a pressure-sensitive adhesive layer is formed is manufactured, and the cover glass is attached to the display panel as an example. However, It is not limited. For example, the cover glass and the display panel may be joined together through an OCA (Optically Clear Adhesive) film or the like.

The cover glass 10 on which the adhesive layer shown in Fig. 1 is formed has a transparent cover glass 12, an adhesive layer 14, a protective film 16, and a light shielding portion 20.

The adhesive layer (14) is formed on the cover glass (12). A region where the adhesive layer 14 is formed in the cover glass 12 is referred to as a placement region 12a. The cover glass 12 is provided with a light shielding portion 20 on the peripheral edge portion 12b and an adhesive layer 14 is formed on the first main surface 12c of the cover glass 12. [

The shape of the cover glass 12 and the adhesive layer 14 is, for example, a rectangular shape when viewed in plan view, and the appearance of the adhesive layer 14 is small. The adhesive layer 14 is disposed on the cover glass 12, for example, with its center aligned. The light shielding portion 20 is formed in a frame shape on the peripheral edge portion 12b of the periphery of the arrangement region 12a on the first main surface 12c of the cover glass 12. [

The shielding portion 20 shields the wiring member or the like connected to the display panel from the second main surface 12d side of the cover glass 12 other than the display surface (display region) . However, in the case where the wiring member or the like of the display panel can not be visually recognized from the side where the display panel is viewed, the light-shielding portion 20 does not necessarily have to be formed.

A protective film 16 covering the entire surface of the cover glass 12 is formed on the first main surface 14a of the adhesive layer 14 so as to be peelable. When the cover glass 10 on which the adhesive layer is formed is bonded to the on-vehicle display device, the protective film 16 is peeled off. In this case, for example, a cut is made on the first main surface 16a of the protective film 16, and the protective film 16 is peeled off. The protective film 16 is not particularly limited, and for example, a relatively flexible film such as polyethylene or polypropylene is used.

[Cover Glass]

The cover glass 12 protects the display surface (display area) of the in-vehicle display device, and is usually a flat plate or a flat plate (glass plate) having a curved surface.

The plate thickness of the cover glass 12 is 0.5 to 2.5 mm. If the plate thickness is less than 0.5 mm, the strength of the cover glass 12 itself becomes insufficient, and the impact resistance of the cover glass 10 on which the adhesive layer is formed may be lowered. If the plate thickness exceeds 2.5 mm, it becomes excessively thick, which is unsuitable for use in on-vehicle display devices from the viewpoint of design.

The outer shape and size of the cover glass 12 are generally larger than the size of the display panel in view of design, mounting of the sensor, and mounting to the display module. The shape of the cover glass 12 is appropriately determined in accordance with the on-vehicle display device in terms of design. However, in such a case, the outer shape of the cover glass 12 is often equivalent to the outer shape of the on-vehicle display device. Depending on the external form of the on-vehicle display device, a cover glass 12 having a shape including a curve in an outer shape that covers the entire surface of the display surface of the display panel can also be used.

As an example of the size of the cover glass 12, for example, in the case of a quadrangle, the longitudinal direction is 100 to 800 mm, and the width direction is 40 to 300 mm.

In this embodiment, as the cover glass 12, for example, a plate-like tempered glass obtained by subjecting a colorless transparent soda lime glass or an aluminosilicate glass (SiO ₂ -Al ₂ O ₃ -Na ₂ O-based glass) Is used.

As the cover glass 12, for example, a chemically tempered glass (for example, "Dragon Trail (registered trademark)" manufactured by Asahi Glass Co., Ltd.) subjected to an ion exchange strengthening treatment on an aluminosilicate glass is preferably used.

Examples of the glass material constituting the cover glass 12 include 50 to 80% of SiO ₂ , 1 to 20% of Al ₂ O ₃ , 6 to 20% of Na ₂ O, , 0 to 11% of K ₂ O, 0 to 15% of MgO, 0 to 6% of CaO and 0 to 5% of ZrO ₂ .

A compressive stress layer is formed on both surfaces of the surface of the chemically strengthened cover glass 12. The thickness of the surface compressive stress layer is 10 占 퐉 or more, preferably 15 占 퐉 or more, more preferably 25 占 퐉 or more , More preferably not less than 30 mu m. The surface compressive stress in the surface compressive stress layer is preferably 650 MPa or more, and more preferably 750 MPa or more.

The method of performing the chemical strengthening treatment on the cover glass 12 is typically a method in which the cover glass 12 is immersed in a KNO ₃ molten salt, subjected to an ion exchange treatment, and then cooled to a temperature near room temperature. The processing conditions such as the temperature and the immersion time of the KNO ₃ molten salt may be set so that the surface compressive stress and the thickness of the surface compressive stress layer are desired values.

[Adhesive layer]

The adhesive layer 14 is for adhering the cover glass 12 to the on-vehicle display device when the cover glass 12 is adhered to the on-vehicle display device. It is preferable that the adhesive layer 14 is transparent in the same manner as the cover glass 12 and that the refractive index difference between the cover glass 12 and the adhesive layer 14 is small.

As the adhesive layer 14, for example, there can be mentioned a layer made of a transparent resin obtained by curing a liquid curable resin composition. Examples of the curable resin composition include a photo-curable resin composition, a thermosetting resin composition and the like, among which a photo-curable resin composition containing a curable compound and a photopolymerization initiator is preferable. As the curable resin composition, for example, the photo-curable resin composition for forming an upper layer described in Patent Document 1 is preferably used.

As described above, OCA or the like, which is hardened separately on the cover glass 12, may be applied to the adhesive layer 14.

The thickness of the adhesive layer 14 is preferably 5 to 400 占 퐉, more preferably 50 to 200 占 퐉, for example. The storage shear modulus at 25 ° C of the adhesive layer 14 is preferably 5 to 5 MPa, more preferably 1 to 30 MPa, for example.

[Method of producing cover glass with adhesive layer formed]

A method of manufacturing the cover glass 10 having the adhesive layer formed thereon will be described. Hereinafter, a mode in which a liquid resin composition is coated on the cover glass 12 and cured is described.

First, the light shielding portion 20 is formed as a frame on the peripheral edge portion 12b of the cover glass 12. The light shielding portion 20 is covered on the entire surface of the first main surface 12c of the cover glass 12 and the curable resin composition is applied by using a method such as die coater or roll coater, Thereby forming a composition film (not shown). The curable resin composition film is cut as described below to form the adhesive layer 14.

Next, a film material (not shown) is pasted on the surface of the curable resin composition film. The film material is cut as described later to form the protective film 16. A film material is attached to the surface of the curable resin composition film and then the curable resin composition film is cured by a photo-curing treatment or a heat curing treatment to obtain a laminate protected with a curable resin composition film film material.

Next, in the obtained laminate, the position at which the side face 14b of the adhesive layer 14 is to be set is set as a cutting line, and the laminate is cut at the cut line using a laser beam. Thereby, the cover glass 10 having the adhesive layer formed with the protective film 16 on the first main surface 14a of the adhesive layer 14 is obtained.

Further, in the case of pasting the pre-cured pressure-sensitive adhesive layer film on the transparent face plate 10 or when the resin composition can be coated with good precision, the cutting step may be omitted.

[Onboard Display]

Next, the in-vehicle display device 100 of the present embodiment will be described.

2 is a schematic sectional view showing the on-vehicle display device 100. As shown in Fig.

As shown in Fig. 2, the on-vehicle display device 100 has a concave housing body 106. Fig. A backlight unit 102 is placed on the bottom case 107 of the case body 106 and the display panel 104 is placed on the backlight unit 102. [ In this manner, the backlight unit 102 and the display panel 104 are housed in the case body 106. [ An opening 108 is formed in the case body 106, and a display panel 104 is disposed on the opening 108 side. An area corresponding to the opening 108 of the display panel 104 is defined as a display surface 104a. The display panel module 100a is configured by using the backlight 102 and the display panel 104 as main constituent members.

Generally, the backlight unit 102 is constituted by a lens sheet, a diffusion sheet, a light guide plate, a lamp, a reflector, etc., and the light guide plate is usually thickest among these. In determining the overall stiffness of the backlight unit, Member. The thickness of the light guide plate is preferably 10 mm or less, more preferably 7 mm or less, and further preferably 5 mm or less. This is to attain thinning of the casing by narrowing the frame. The thickness of the light guide plate is preferably 1 mm or more, more preferably 2 mm or more, and further preferably 4 mm or more. This is to prevent breakage of the light guide plate due to bending stress when an impact is applied to the backlight unit.

The Young's modulus of the material for forming the light guide plate is preferably 1 mm or more, more preferably 2 mm or more, still more preferably 3 mm or more, and particularly preferably 60 mm or more. This is to improve the impact resistance of the cover glass.

The coefficient of linear expansion of the material forming the light guide plate is preferably 800 占^10-7 / 占 폚 or lower, more preferably 600 占^10-7 / 占 폚 or lower, and still more preferably 200 占^10-7 / 占 폚 or lower. This is for suppressing the rise of temperature in the vehicle interior and the thermal expansion of the light guide plate caused by the light source in the backlight unit and achieving the thinness of the case body by making the frame narrow.

It is preferable that the minimum value of the internal transmittance in the wavelength range of 400 to 700 nm is 80% or more and the difference between the maximum value and the minimum value of the internal transmittance is 15% or less under the condition of the optical path length of 50 mm, Or less. It is more preferable that the minimum value of the internal transmittance is 85% or more and the difference between the maximum value and the minimum value of the internal transmittance is 13% or less. When the minimum value of the internal transmittance is 90% or more and the difference between the maximum value and the minimum value of the internal transmittance is 8% Or less.

The material for forming the light guide plate is not particularly limited as long as it meets the above conditions and the completed on-vehicle display device 100 satisfies the following formula (I). The material for forming the light guide plate is concretely acrylic resin, polycarbonate, glass or the like, among which glass is preferable. This is because the Young's modulus is excellent, the strength of the casing and the backlight unit is achieved, the expansion due to heat and moisture is small, and the casing is thin. The glass may be reinforced, and it is preferable that the glass is chemically reinforced regardless of its chemical or physical properties. It is also preferable that the end face of the glass be chamfered. More preferably, it is chemically strengthened after chamfering. This is to prevent cracking from the end face of the light guide plate due to vibration of the vehicle display device.

The structure of the display panel 104 and the material of the case body 106 (including the case body bottom member 107) are not limited as long as the on-vehicle display device 100 satisfies the following formula (I) And is not particularly limited. The shape and size of the outer shape of the case body bottom member 107 are appropriately determined in accordance with the external shape of the on-vehicle display device 100. In the on-vehicle display device 100, the display panel module 100a is also thinned by design today. Therefore, it is general that the outer shape of the display panel 104 is a rectangle such as a rectangle. In this case, it is preferable that the outer shape of the case body bottom member 107 is rectangular. When the boundary between the cover glass 12 and the display panel 104 is referred to as a stepped portion 300 when CG is viewed from the plane of the case body bottom member 107, It is preferable that the case body bottom member 107 is attached to the lower portion so as to cover the step portion 300 entirely. This is because it exhibits excellent impact resistance in the head impact test described later. It is more preferable that the size of the case body bottom member 107 is the same as or larger than that of the cover glass 12.

When the unoccupied area from the display panel end to the cover glass end is wide, it is preferable that the case body bottom member 107 is attached to the lower portion so as to cover the stepped portion 300 with this CG.

Further, one or more additional plate-shaped members may be further adhered to the lower surface side of the case body bottom member 107, for example. With regard to the plate-like member, it is preferable that the CG is attached to the lower portion so as to cover the step portion 300 entirely when seen from the vertical in the vertical direction. This is also because it shows excellent impact resistance in a head impact test described later. It is more preferable that the size of the plate member is the same as or larger than that of the cover glass 12.

There is a step from the display surface 104a of the display panel 104 to the end face 106a of the case body 106 in the opening 108 of the case body 106 as shown in Fig.

The cover glass 10 on which the adhesive layer is formed can be obtained by peeling off the protective film 16 and then filling the opening 108 of the case body 106 so that the adhesive layer 14 contacts the display surface 104 of the display panel 104 (104a). Thereby, the cover glass 12 is covered from the display surface 104a of the on-vehicle display device 100 to the end surface 106a of the case body 106. [ The cover glass 12 functions as a protective member of the display surface 104a of the on-vehicle display device 100. [

As described above, the in-vehicle display device of the present invention has a structure in which the cover glass is the first layer and layers from the first layer to the n-th layer are laminated. Specifically, for example, in the on-vehicle display device 100 described above, at least the cover glass 12 (first layer), the display panel 104 (second layer), the backlight unit 102 Layer), and a case body bottom member 107 (fourth layer) are stacked in this order. In addition, the in-vehicle display device has no backlight unit and has at least three layers of a cover glass (first layer), a display panel (second layer), and a case bottom member (third layer) . For example, in the case where the display panel is an organic EL panel or a PDP panel, the above-described structure does not have a backlight unit.

In practice, an adhesive layer exists between the cover glass (first layer) and the display panel (second layer). The handling of the adhesive layer will be described later.

The above-mentioned on-vehicle display device is characterized in that the cover glass is a member of the first layer (that is, the first layer of the surface layer on the display surface side), one or more kinds of members The lamination means a configuration in which the constituent members are sequentially assembled in the order or sequentially assembled in that order, and each constituent member is composed of a constituent member Or may be laminated in a part or the whole with a gap therebetween, or may be a structure in which a part is surrounded or overlapped, or a laminated structure of various variations is included .

Incidentally, in the on-vehicle display device, the cover glass is required to have excellent impact resistance to such an extent that even if the head portion of the passenger collides with the passenger in the event of a collision of the vehicle, the passenger is not cracked.

The inventors of the present invention have found that when the on-vehicle display device having the above configuration satisfies the following formula (I), the impact resistance of the cover glass is excellent.

Equation (I) ... ... P? 0.0302t ₁ ² + 0.0039t ₁ + 0.0478

However, in the formula (I)

P = E ₁ / (E ₁ t ₁ ² + ... + E _n t _n ² )

E ₁ : Young's modulus of cover glass (unit: ㎬)

t ₁ : thickness of cover glass (unit: mm)

E _n : Young's modulus of the member of the n-th layer (unit: ㎬)

t _n : Thickness of the n-th layer (unit: mm)

to be. In the above formula, n is an integer of 2 or more.

The excellent impact resistance of the cover glass when the formula (I) is satisfied is shown in [Examples] described later. That is, in the examples, the cover glass is cracked in the case of not satisfying the formula (I) (comparative example), while the cover glass is not cracked in the case of satisfying the formula (I) .

In addition, for example, in the on-vehicle display device described above, the four layers of the cover glass (first layer), the display panel (second layer), the backlight unit (third layer) Layer structure, the above-mentioned P is expressed as follows.

P = E ₁ / (E ₁ t ₁ ² + E ₂ t ₂ ² + E ₃ t ₃ ² + E ₄ t ₄ ² )

E ₁ : Young's modulus of cover glass (unit: ㎬)

t ₁ : thickness of cover glass (unit: mm)

E ₂ : Young's modulus of display panel (unit: ㎬)

t ₂ : thickness of display panel (unit: mm)

E ₃ : Young's modulus of backlight unit (unit: ㎬)

t ₃ : thickness of backlight unit (unit: mm)

E ₄ : Young's modulus of bottom member of case body (unit: ㎬)

t ₄ : Thickness of the case bottom member (unit: mm)

to be.

In addition, the backlight unit has a structure in which several thin functional films such as a glass plate, a polycarbonate plate or an acrylic resin, and a reflection type polarizing film and a brightness enhancement film are laminated, In order to control the rigidity of the backlight unit, the Young's modulus of the light guide plate is calculated as the Young's modulus of the backlight unit.

The Young's modulus (E ₁ ) of the cover glass is preferably from 60 to 80 하고, more preferably from 70 to 80..

The Young's modulus (E ₂ ) of the display panel is preferably 60 to 80 하고, more preferably 70 to 80..

The Young's modulus (E ₃ ) of the backlight unit is preferably 1 to 90,, more preferably 2 to 90 하고, and even more preferably 60 to 90..

The Young's modulus (E ₄ ) of the bottom of the case body is preferably from 40 to 250 하고, more preferably from 150 to 250.. Further, the display panel, the backlight unit, and the housing may be a composite material formed by combining a plurality of materials. In this case, it is preferable that the Young's modulus of the entire composite material falls within the above-mentioned numerical range.

The Young's modulus of each member is measured by a tensile test (JIS K 7161, JIS K 7113).

The thickness t ₁ of the cover glass is 0.5 to 2.5 mm, preferably 0.7 to 2 mm, more preferably 1.3 to 2 mm.

The thickness of the display panel (t ₂₎ is, 1 ~ 2 ㎜ is preferred, more preferably 1.1 ~ 1.3 ㎜.

The thickness t ₃ of the backlight unit is preferably 1 to 10 mm, more preferably 2 to 6 mm, and further preferably 3 to 5 mm.

The thickness t ₄ of the bottom body of the case body is preferably 0.5 to 4 mm, more preferably 1 to 4 mm.

The thickness of each member is the length in the vertical direction in Fig.

In addition, in the on-vehicle display device described above, at least one of the members from the cover glass (first layer) to the nth layer is actually an adhesive layer. For example, in the four-layer structure described above, an adhesive layer 14 (referred to as a 1.5th layer) is disposed between the cover glass 12 (first layer) and the display panel 104 (second layer) .

Here, in consideration of the Young's modulus (E _1.5 ) and the thickness (t _1.5 ) of the pressure-sensitive adhesive layer, the above-mentioned P is expressed as follows.

P = E ₁ / (E ₁ t ₁ ² + E _1.5 t _1.5 ² + E ₂ t ₂ ² + E ₃ t ₃ ² + E ₄ t ₄ ² )

However, the Young's modulus (E _1.5 ) of the adhesive layer is sufficiently small as compared with the Young's modulus of the other layers, and its thickness (t _1.5 ) is, for example, 5 to 400 μm. Therefore, the value of "E _1.5 t _1.5 ² " in the above P is small enough to be negligible in comparison with the other values of "E ₁ t ₁ ² " to "E ₄ t ₄ ² ".

Therefore, even in the case where an adhesive layer exists in the laminated structure (first layer to nth layer), it can be considered that no adhesive layer exists in the present embodiment when the formula (I) is considered. In other words, it is assumed that the value of "E _1.5 t _1.5 ² " is 0 (zero), and the value of P can be obtained.

P in the formula (I) will be described.

First, with respect to the curvature (all layers are the same) and the stress occurring in each layer when the beams (combination beams) arranged in layers in a form in which the different materials are parallel to the neutral axis of bending are subjected to bending, Consider the following formulas (1) to (3) (A _i : cross sectional area of i layer, E _i : Young's modulus of i layer, I _i : second moment of section of i layer, n: number of layers).

· Position of neutral axis

[Equation 1]

· Curvature

&Quot; (2) "

&Quot; (3) "

(4) to (6) (M: bending moment, y ': position of the neutral axis, y: distance from the neutral axis) when the four-layer structure shown in Fig. 3 is considered.

&Quot; (4) "

&Quot; (5) "

&Quot; (6) "

Here, in the case of considering the four-layer structure of the cover glass / display panel / backlight unit / case body bottom member, it is preferable that the stress generated on the back surface of the cover glass as the first layer is low in order to prevent the cover glass from cracking. In short, it is preferable that? ₁ of the formula (4) is smaller, and that the Young's modulus of each member constituting the layer is high, and the thicker the layer, the smaller σ ₁ is.

From Equation (6), it can be seen that the secondary moment of inertia has a correlation with the third square of the thickness of the cover glass. From Equation (4), the back side position y of the first layer, From the equations (4) and (6), a P value represented by the following equation is derived as a parameter for determining that the cover glass is not cracked / cracked.

P = E ₁ / (E ₁ t ₁ ² + E ₂ t ₂ ² + E ₃ t ₃ ² + E ₄ t ₄ ² )

The display panel may be a liquid crystal panel, an organic EL panel, a PDP, an electronic ink-type panel, or the like, and may have a touch panel or the like.

In the case of a display panel other than the liquid crystal panel, for example, in the case of an organic EL panel or a PDP, calculation is performed in a configuration excluding the backlight unit.

Such on-vehicle display devices include, for example, on-dash type car navigation devices formed on a dashboard, in-dash type car navigation devices embedded in a dashboard of a vehicle, But may be a device other than the device (for example, an instrument panel).

Example

Hereinafter, embodiments of the present invention will be described in detail with reference to examples and the like, but the present invention is not limited to these examples.

<Preparation of cover glass>

As the cover glass, tempered glass (trade name: "Dragon Trail" (registered trademark) manufactured by Asahi Glass Co., Ltd.) having a chemical strengthening treatment on the aluminosilicate glass, the thickness of the compressive stress layer: 38 μm, the surface compressive stress : 774 MPa).

&Lt; Preparation of Cover Glass Having Adhesive Layer &gt;

An OCA film (&quot; MHM-FWD &quot; manufactured by Nichia Corporation) was laminated on the first main surface of the cover glass to produce a cover glass having an adhesive layer formed thereon.

&Lt; Preparation of test piece &

First, a test body 200 was manufactured in order to perform a test for colliding a rigid body model (also referred to as &quot; head impact test &quot;). The test body 200 will be described with reference to Figs. 4 to 6. Fig.

4 is a perspective view showing the test body. 5 is a sectional view taken along the line A-A in Fig. 6 is a plan view showing a test body.

The test body 200 is a on-dash type on-vehicle display device 100.

The on-vehicle display device 100 has a case body bottom member 107 as a thin plate. On the peripheral edge portion of the case body bottom member 107, four case body frames 109 with ribs formed therein are arranged. A case body 106 having a quadrangular concave portion in a central region is formed by the case body bottom member 107 and the four case frame 109. The backlight unit 102 and the display panel 104 as a main constituent member are disposed on the display panel module 100a.

The upper end of the backlight unit 102 is bonded to the lower end of the display panel 104 by a double-faced tape 207 or the like. Therefore, an air gap exists between the display panel 104 and the backlight unit 102 by the thickness of the double-faced tape 207 or the like. The gap between the backlight unit 102 and the display panel is 0.5 to 1.5 mm. In general, the air gap is set at 1.5 mm, and it is not necessary to have an air gap of 1.5 mm depending on the situation. This air gap is controlled by the thickness of the adhesive member such as the double-sided tape 207 or the like and may not be used depending on the situation. The upper surface of the display panel 104 is positioned lower than the upper surface of the case frame 109 arranged around it, and is a concave portion. And the adhesive layer 14 of the cover glass 10 on which the adhesive layer is formed is bonded to the upper surface of the display panel 104 so as to embed this recessed portion. When the boundary between the cover glass 12 and the display panel 104 is CG, the stepped portion 300 is formed. On the upper side of the side surface of the cover glass 12 and on the upper surface of the case frame 109, a case frame 110 is disposed.

The on-vehicle display device 100 of this type is constituted of a solid fixed rib 213 integrated with a flat support plate 215 by a bolt 211 disposed in a gap in one case frame 109, As shown in FIG.

Further, in an actual on-vehicle display device, it is preferable that the case body bottom member 107 is attached to the lower portion so as to cover the step portion 300 entirely if it is CG when viewed from the vertical direction from the rear face. In addition, the distance between the outer periphery to the vehicle display device 100, the CG is step portion 300 as shown in FIG. 5 as L _2, and when the L ₁ to L _2/2, the case body floor member 107 As shown in Fig. 5 (a), one having a size larger than L1 by _one end than the dimension when viewed from the end face of the display panel 104 (that is, one side of the case body bottom member 107, 2L ₁ or more than one side of the display panel 104), and it is preferable that the whole of the stepped portion 300 be covered by CG. This is because the effect of reducing the tensile stress at the stepped portion 300 can be expected in the case of the CG at the head impact test. Further, it is more preferable to cover the whole of the stepped portion 300 using CG having a dimension larger than L _{1 and not} more than L _{2 at one} end than the dimension at the end face of the display panel 104. As shown in Fig. 5 (b), by using the one having a size larger by L ₂ than the dimension when viewed from the end face of the display panel 104 (in other words, when viewing the on-vehicle display device 100 in a vertical plane , It is more preferable to cover the entire step portion 300 with CG. This is because the effect of reducing the tensile stress at the stepped portion 300 can be expected most when the head impact test is performed.

Also in the actual on-vehicle display device, if the CG is the stepped portion 300, the case body bottom member 107 is stuck to the lower portion and the ribs at several positions with respect to the case frame 109 It is preferable to improve the rigidity by adopting the formed rib structure. This is because, in the housing frame 109, a resin material is often used in the design of the display panel and the rigidity is poor due to the resin. By adopting the rib structure, excellent impact resistance . The case body 106 may be a structure in which the case body frame 109, the case body bottom member 107, and the case body frame 110 are separated from each other, or may be a molded product that is entirely integrated, And is not particularly limited.

The cover glass 12, the display panel 104, the backlight unit 102 and the case body bottom member 107 were changed and the Young's modulus and thickness were measured in the following Table 1 And as shown in Table 2.

In the test piece 200, soda lime glass was used instead of the display panel 104, and a polycarbonate plate was used instead of the backlight unit 102.

As the case body bottom member 107, an aluminum plate (Young's modulus: 68.6 mm) or an iron plate (Young's modulus: 206 mm) was used.

In the case of the above-described display panel comprising a conventional TFT liquid crystal panel, the constitution is basically the same as that of the polarizing plate / glass substrate (for example, 0.55 mm plate thickness) / liquid crystal layer / glass substrate Plate thickness) / polarizing plate, and since the polarizing plate and the liquid crystal layer have low rigidity, the glass plate of the liquid crystal panel dominates the rigidity. Therefore, the Young's modulus of the glass substrate constituting the liquid crystal panel was substituted and calculated.

6, sizes H ₁ to H ₃ and W ₁ to W ₃ are H ₁ : 120 mm, H ₂ : 150 mm, H ₃ : 250 mm, W ₁ : 173 mm, W ₂ : 250 mm , W _{3 is} 350 mm, and the size of the case body bottom member 107 is 160 mm x 260 mm larger than the size of the display panel 104.

In the specimen 200, other parts were made as follows.

· Adhesive layer (14) ... Thickness: 175 占 퐉, length: 120 mm, width: 173 mm, storage shear modulus: 8 mm,

· Double-sided tape (207) ... Quot; Scotch PBT-10 &quot; manufactured by Sumitomo 3M, tape width: 5 mm, tape thickness: 0.5 mm,

· Case frame (109) ... Material: ABS, Thickness: 1 mm,

· Case frame frame (110) ... Material: ABS, plate thickness: 2 mm, width: 5 mm,

· Bolts (211) ... Material: Iron,

· Fixed rib (213) ... Material: iron, size: 19 mm x 100 mm x 50 mm,

· Support plate (215) ... Material: iron, plate thickness: 9 mm, length: 250 mm, width: 350 mm.

<Evaluation of Impact Resistance (Head Impact Test)>

Next, a support plate 215 of the test body 200 was placed on a horizontal plane, and an impact absorption cushion ("CF45" manufactured by KCC Corporation, thickness: 25.4 mm) was placed between the on-vehicle display device 100 and the support plate 215 (Material: iron, diameter: 165 mm, mass: 20 mm) is attached to the impact position P (see Fig. 6) of the second main surface 12d of the cover glass 12, 19.6 kg) was dropped from the height of 794 mm at a collision speed of 3.9 m / s so that the energy at the time of impact was 152.5 J.

The test method refers to the "Technical Standard for Shock Absorption of Attachment 28 Instrument Panel" (hereinafter referred to simply as "standard") of "Article 20 Riding Device" in "Security Standards for Road Transport Vehicles" indicated by the Ministry of Land, . In this &quot; Standard &quot;, a spherical rigid body model (material: iron, diameter: 165 mm, mass: 6.8 kg) was injected at a collision speed of 6.7 m / s and collided to make the energy at impact at 152.4 J .

That is, in the head impact test using the test body 200, the energy at the time of impact was made equal to the &quot; reference &quot;.

6) on the cover glass 12 that collides with the rigid body model is located at a position closer to the fixed rib 213 side than the center of the display panel module 100a when viewed from the upper surface of the specimen 200 Was placed on the opposite side. More specifically, the collision position P is on the display panel 104, not on the case frame 109, but at a position inside the display panel 104 by 10 mm.

As a result of collision of the rigid body model, the case where the cover glass was not cracked was indicated as &quot;? &Quot;, and the case where the cover glass was cracked was designated as &quot; x &quot; If it is &quot;? &Quot;, it can be evaluated that it exhibits excellent impact resistance that is not cracked even if the head portion of the passenger or the like collides with the passenger in the event of a collision. The results are shown in Tables 1 and 2 below.

As is evident from the graph shown in Fig. 7, in the case where the cover glass does not satisfy the formula (I) (comparative example), the cover glass cracks, while when the formula (I) is satisfied I could see that it was not.

Industrial availability

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a vehicle-mounted display device having excellent impact resistance of a cover glass, and is useful as a vehicle-mounted display device mounted on a vehicle such as an automobile.

The entire contents of the specification, claims, drawings and summary of Japanese Patent Application No. 2014-169322 filed on August 22, 2014 are hereby incorporated herein by reference.

10: Cover glass formed with an adhesive layer
12: Cover glass
12a: Batch area
12b:
12c: a first main surface of the cover glass
12d: the second main surface of the cover glass
14: Adhesive layer
14a: a first main surface of the adhesive layer
14b: Side of the adhesive layer
16: Protective film
16a: the first main surface of the protective film
20:
100: on-vehicle display
100a: Display panel module
102: Backlight unit
104: Display panel
104a: display surface
106: Case body
106a: cross-section of case body
107: Case body bottom member
108: opening
109: Case frame
110: Case frame frame
200: Test body
207: Double-sided tape
211: Bolt
213: Fixed rib
215:
300: CG,
P: collision position

Claims (7)

An on-vehicle display device comprising a cover glass as a first layer and a member up to an n-th layer laminated,
Wherein the cover glass is tempered glass having a thickness of 0.5 to 2.5 mm and a thickness of a surface compressive stress layer of 10 m or more,
The on-vehicle display device satisfies the following formula (I).
Equation (I) ... P? 0.0302t ₁ ² + 0.0039t ₁ + 0.0478
(Provided that in the formula (I)
P = E ₁ / (E ₁ t ₁ ² + ... + E _n t _n ² )
E ₁ : Young's modulus of cover glass (unit: ㎬)
t ₁ : thickness of cover glass (unit: mm)
E _n : Young's modulus of the member of the n-th layer (unit: ㎬)
t _n : thickness of the n-th layer (unit: mm)
to be. Here, n is an integer of 2 or more.) The method according to claim 1,
Wherein the display panel and the case body bottom member are provided on the member from the cover glass to the nth layer, and the size of the case body bottom member is larger than the display portion of the display panel. 3. The method according to claim 1 or 2,
Wherein the backlight unit includes a light guide plate, and the light guide plate is made of glass. 4. The method according to any one of claims 1 to 3,
And a display panel, a backlight unit, and a case body bottom member on a member from the cover glass to the nth layer, wherein the backlight unit is mounted on the case body bottom member, and the display panel is mounted on the backlight unit In-vehicle display device. 5. The method according to any one of claims 1 to 4,
Wherein at least one of the members from the cover glass to the nth layer includes an adhesive layer and the thickness of the adhesive layer is 5 to 400 mu m. 6. The method according to any one of claims 1 to 5,
Wherein the cover glass has a surface compressive stress of 650 MPa or more. 7. The method according to any one of claims 1 to 6,
Wherein the cover glass is a chemical tempered glass having a plate thickness of 0.5 to 2.5 mm, a thickness of a surface compressive stress layer of 10 m or more, and a surface compressive stress of 650 MPa or more.

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