JP7484384B2 - Display device - Google Patents

Description

This disclosure relates to a display device used, for example, in a vehicle instrument device.

One example of a conventional display device is that disclosed in Patent Document 1. The display device in Patent Document 1 has a structure in which a transparent cover plate and a display made of liquid crystal are bonded together with a light-curing adhesive. The light-curing adhesive is filled into an area surrounded by a frame-shaped retaining frame, and prevents the adhesive from protruding from between the cover plate and the display.

This method requires a retaining frame, which increases parts costs. To solve this problem, a method is known in which a dike is formed using a high-viscosity adhesive, and the area surrounded by this dike is filled with a light-curing adhesive.

JP 2017-026999 A

However, there were problems with this, such as the dike moving due to the filling pressure of the light-curing adhesive, causing the light-curing adhesive to protrude from between the cover plate and the display, resulting in reduced product yield.

Therefore, this disclosure has been made in consideration of these points, and aims to provide a display device that prevents the light-curing adhesive from protruding from between the cover plate and the display.

In order to achieve the above-mentioned object, the display device 100 of the present disclosure has at least a display means 2 having a display element 21 provided with a display area 21a capable of displaying predetermined information, a protective member 1 covering the display means 2 on the front side of the display means 2, a resin member 5 filling a gap formed between the display means 2 and the protective member 1 and adhering the display means 2 to the protective member 1, and an embankment member 6 arranged in the gap formed between the display means 2 and the protective member 1 and on the outer periphery of the resin member 5, wherein the protective member 1 has uneven portions 13, 15 formed in a concave or convex shape at a position facing the embankment member 6 , and a colored layer 12 on the display means 2 side, the uneven portions 13, 15 do not have the colored layer 12, the embankment member 6 is formed in a similar color to the colored layer 12, the uneven portions 13, 15 hold the embankment member 6 , and the embankment member 6 blocks the resin member 5 from flowing out of the gap .

1 is a front view of a display device according to a first embodiment of the present disclosure. 2 is a cross-sectional view taken along line AA of the display device shown in FIG. 1. FIG. 4 is a diagram corresponding to FIG. 2 of a display device according to a second embodiment of the present disclosure.

A display device 100 according to an embodiment of the present disclosure will be described with reference to Figures 1 to 3.

The display device 100 is mounted on a vehicle (e.g., an automobile) and configured as an instrument device that displays a predetermined measurement quantity (such as vehicle speed). However, the display device 100 can also be applied to an instrument device for a vehicle mounted on a moving object such as a motorcycle or agricultural or construction machinery.

In the following, to facilitate understanding of the configuration of the display device 100, the direction in which the user seated in the driver's seat of the vehicle is viewed from the display device 100 (the cover plate 1 side) is referred to as the "front" for each component, and the opposite side (the circuit board 4 side) is referred to as the "rear", and these are indicated by the arrows "Fr." and "Re." in the figure.

(First embodiment)
As shown in Figures 1 and 2, the display device 100 at least comprises a display (display means) 2 having a display element 21 with a display area 21a capable of displaying predetermined information, a cover plate (protective member) 1 covering the display 2 from the front side thereof, a circuit board 4 arranged behind the display 2, a transparent adhesive layer (resin member) 5 filling the gap formed between the display means 2 and the cover plate 1 and adhering the display means 2 and the cover plate 1, a case body 3 arranged between the cover plate 1 and the circuit board 4 and supporting the cover plate 1, and a dike member 6 arranged in the gap formed between the display means 2 and the cover plate 1 and on the outer periphery of the transparent adhesive layer 5.

The cover plate 1 is disposed on the front surface of the case body 3 and is made of a base material 11 and a light-shielding layer (colored layer) 12. The base material 11 is made of, for example, a transparent or translucent thin-plate synthetic resin (for example, polycarbonate or acrylic). The light-shielding layer 12 is made of a base material 11 with a light-shielding ink colored black printed over almost the entire area of its back surface.

The light-shielding layer 12 has a window portion 12a and a light-emitting portion 12b. The window portion 12a is formed in a substantially rectangular shape in correspondence with the display area 21a at a position substantially in the center of the display device 100, and is a portion where the light-shielding layer 12 is not formed. The window portion 12a allows the driver to see through the display area 21a. The light-emitting portions 12b are arranged in multiple units around the outer periphery of the window portion 12a, and are formed in the shape of icons, symbols, etc., in the form of so-called cut-out characters, and are the portion that forms the design of a specified operation light or warning light.

The cover plate 1 has a recess (uneven portion) 13 on the back surface of the base material 11. The recess 13 is a U-shaped recessed cutout that opens on the back surface side. The recess 13 is formed so as to cover the outer periphery of the window portion 12a at a position between the window portion 12a and the light-emitting portion 12b and at a position opposite the front edge portion 27b of the frame 27 described below.

The display device 2 is composed of a display element 21 arranged in front and provided with a roughly rectangular display area 21a, a lighting means 26 consisting of an optical sheet 22, a light guide 23, a reflector 24, and a panel light source 25 for directing illumination light from behind the well-known display element 21, a frame 27 made of a metal such as aluminum that holds and houses the display element 21 and the lighting means 26, and a flexible printed circuit (FPC) 28 that is connected to the display element 21 and the panel light source 25 and leads out from the back of the frame 27 to the outside.

The display element 21 is, for example, a dot-matrix type TFT (Thin Film Transistor) LCD (Liquid Crystal Display) display panel having a plurality of pixels. The display element 21 is electrically connected to the circuit board 4 via a flexible wiring board 28, and displays predetermined information related to the vehicle, such as engine speed, average fuel efficiency, fuel consumption, and outside air temperature, as an image in the display area 21a based on various information acquired from the vehicle's ECU (Electronic Control Unit).

The frame 27 is made of a conductive metal material such as aluminum or stainless steel, and has a roughly rectangular opening 27a at the front corresponding to the display area 21a, and a front edge 27b that is the outer periphery of the opening 27a and is located between the cover plate 1 and the display element 21.

The panel light source 25 is made of a vertically emitting LED (chip-type light emitting diode: Light Emitting Diode), emits light of any color in a direction parallel to the surface direction of the display element 21, and causes the light to enter the light guide 23. The light guide 23 is made of a transparent, flat synthetic resin plate, guides the light from the panel light source 25, and emits the light to the optical sheet 22 via a white reflector 24. The optical sheet 22 is made of, for example, a diffusion sheet or a prism sheet, and diffuses the light from the light guide 23 and transmits it toward the display element 21.

One end of the flexible wiring board 28 is connected to the rear surface of the circuit board 4, and electrically connects the display 2 to the circuit board 4. The display 2 may be an organic electroluminescence display (OELD) or the like.

The case body 3 is made of, for example, a light-blocking white synthetic resin material (e.g., polypropylene) and is disposed behind the display 2 and in front of the circuit board 4. The case body 3 has a storage section 31 and an illumination chamber 32.

The storage section 31 is formed in a concave shape so as to cover the back side of the display unit 2 except for the front side, and stores the display unit 2. The lighting chamber 32 is formed in a cylindrical shape corresponding to each light-emitting unit 12b, and stores the light source 7 arranged on the circuit board 4 described later.

The light source 7 is a chip-type light-emitting diode that emits an appropriate color and is disposed in the lighting chamber 32 on the circuit board 4 behind the light-emitting portion 12b. The light emitted by the light source 7 is efficiently reflected by the inner surface of the lighting chamber 32, reaches the cover plate 1, and passes through the light-emitting portion 12b, allowing the user to visually recognize the light-emitting portion 12b.

The circuit board 4 is constructed by printing various wiring on an insulating plate-shaped base material made of, for example, glass epoxy resin (glass fiber reinforced plastics). The light source 7, control unit 8, necessary electronic elements (not shown), etc. are mounted on the front side of the circuit board 4 and are electrically connected. The control unit 8 causes the display unit 2 to display based on information input from the outside.

The embankment member 6 is a silicone-based adhesive colored black, similar to the light-shielding layer 12. The embankment member 6 is adhesive (an intermediate state between liquid and solid) and is applied generously so that it overflows into the recess 13 of the cover plate 1. The embankment member 6 is then placed in the gap formed between the recess 13 and the front edge portion 27b when the display 2 and the cover plate 1 are attached. The embankment member 6 is a material with a higher viscosity than the transparent adhesive layer 5, and temporarily bonds the cover plate 1 and the display 2. The embankment member 6 may be hardened by various methods, such as natural drying or UV irradiation.

The transparent adhesive layer 5 is a transparent silicone-based optical adhesive. The transparent adhesive layer 5 is in a liquid state and fills the gap formed between the cover plate 1 and the display 2, and the space formed by the cover plate 1, the display 2, and the embankment member 6. The transparent adhesive layer 5 is then cured by various methods such as natural drying or UV irradiation, and bonds the cover plate 1 and the display 2 together. The refractive index of the transparent adhesive layer 5 is set to be approximately the same as the refractive index of the cover plate 1.

The transparent adhesive layer 5 prevents interfacial reflection between the cover plate 1 and the air layer or between the display element 21 and the air layer, improving the visibility of the specified information displayed in the display area 21a. The transparent adhesive layer 5 and the embankment member 6 may be made of a urethane-based or acrylic-based adhesive.

By forming the embankment member 6 in this manner, the embankment member 6 is formed to fill the recess 13. Therefore, even if the filling pressure of the transparent adhesive layer 5 is applied to the embankment member 6 when the transparent adhesive layer 5 is being filled, the embankment member 6 is caught in the recess 13 and does not move, so that it is possible to prevent the liquid from flowing out of the gap formed between the cover plate 1 and the display 2.

In addition, the embankment member 6 is colored in a similar color to the light-shielding layer 12, which reduces the outward appearance of the recess 13.

Second Embodiment
A second embodiment of the display device according to the present disclosure will be described with reference to Fig. 3. The same parts and equivalent parts as those in the first embodiment will be described with the same reference numerals.

In the first embodiment, the light-shielding layer 12 was formed on the back surface of the substrate 11, but in this embodiment, the light-shielding layer 12 is printed on the front surface of the substrate 11 in the same printing range as the light-shielding layer 12, forming the light-shielding layer 14. The light-shielding layer 14 has a window portion 14a and a light-emitting portion 14b, similar to the light-shielding layer 12.

In this embodiment, the recess 13 is formed as a convex portion (uneven portion) 15 that protrudes in a U-shape on the back side. The convex portion 15 is formed in the same position as the recess 13. The embankment member 6 is adhesive and applied generously to the inside of the convex portion 15. The embankment member 6 is then placed in the gap formed between the convex portion 15 and the front edge portion 27b when the display 2 and the cover plate 1 are attached together.

By forming the embankment member 6 in this manner, even if the filling pressure of the transparent adhesive layer 5 is applied to the embankment member 6 when the transparent adhesive layer 5 is filled, the embankment member 6 is caught by the protrusion 15 and does not move, so that it can prevent the liquid from flowing out of the gap formed between the cover plate 1 and the display 2.

Note that this disclosure is not limited to the embodiment described above, and various modifications are possible within the scope of the gist of this disclosure without departing from the scope of this disclosure.

1 Cover plate (protective member)
11 Substrate 12 Light-shielding layer (colored layer)
12a Window portion 12b Light emitting portion 13 Recessed portion (uneven portion)
14 Light-shielding layer (colored layer)
14a Window portion 14b Light emitting portion 15 Convex portion (concave-convex portion)
2. Display (display means)
21 Display element 21a Display area 3 Case body 31 Recess 32 Illumination chamber 4 Circuit board 5 Transparent resin sheet (resin member)
6 Embankment member 7 Light source 8 Control unit

Claims (3)

A display means having a display element provided with a display area capable of displaying predetermined information;
a protective member covering the display means on a front surface of the display means;
a resin member that fills a gap formed between the display means and the protective member and bonds the display means and the protective member;
a barrier member disposed in a gap between the display means and the protective member and on an outer periphery of the resin member;
In a display device having at least
the protective member has an uneven portion formed in a concave or convex shape at a position facing the bank member, and a colored layer on the display means side,
The uneven portion does not have the colored layer,
The embankment member is formed in a similar color to the colored layer,
The display device, characterized in that the uneven portion holds the embankment member, and the embankment member blocks the resin member from flowing out of the gap. The display device according to claim 1, characterized in that the uneven portion is formed in the concave shape, and the embankment member is filled inside the concave shape. the colored layer has a window portion through which the display means can be seen, and a light-emitting portion on an outer periphery of the window portion,
A light source is provided behind the light emitting unit,
The display device according to claim 1 , wherein the uneven portion is located between the window portion and the light-emitting portion.

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