Indication device

Abstract

To provide a display device which can reduce adhesion of dust to a display surface of a display.SOLUTION: A display device includes a display part 40 having a display surface 41, a platy circuit board 50 arranged on the rear side of the display part 40, a first case member 20 covering a front face 51 which is the display part 40 side of the circuit board 50, and a second case member 60 covering a back face 52 of the circuit board 50, wherein the second case member 60 has a hole part 61a inserted to the outside, the first case member 20 has a first projection 23 which is formed at a position facing the front face 51 outside the display part 40 so as to protrude in the rib form, and the second case member 60 has an opposite face part 63a opposite to the back face 52.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a display device mounted on a vehicle such as an automobile. [Background technology]

[0002] An example of a conventional display device is disclosed in Patent Document 1. This display device is composed of a display, an inside cover placed in front of the display, a lens (transparent member) placed in front of the inside cover, an inner case that holds the display, a circuit board placed behind the inner case on which the inner case is placed, and a lower case that covers these from behind, and displays various information as images on the display surface of the display. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-196094 Summary of the Invention [Problem to be solved by the invention]

[0004] In the past, dust and other particles that entered through the lower case would move around the periphery of the circuit board toward the display at the front of the circuit board, but would not adhere to the display surface because they were blocked by the middle case. However, in recent years, as the display surfaces of displays have become larger, displays have come to be placed directly on the circuit board rather than held in the middle case, which has led to problems such as dust adhering to the display surface and reducing the marketability of the display.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a display device that can reduce the adhesion of dust to the display surface of the display. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the display device of the present invention includes a display unit 40 having a display surface 41, a flat circuit board 50 arranged behind the display unit 40, a first case member 20 covering a front surface 51 of the circuit board 50 on the display unit 40 side, and a second case member 60 covering a rear surface 52 of the circuit board 50, wherein the second case member 60 has a hole portion 61a for insertion with the outside, the first case member 20 has a first protrusion portion 23 formed in a protruding rib shape at a position outside the display unit 40 and facing the front surface 51, and the second case member 60 has an opposing surface portion 63a facing the rear surface 52. The opposing surface portion 63a has a gap G2 with the rear surface 52. It is characterized by: The device also comprises a display unit 40 having a display surface 41, a flat circuit board 50 arranged behind the display unit 40, a first case member 20 covering the front surface 51 of the circuit board 50 on the display unit 40 side, and a second case member 60 covering the back surface 52 of the circuit board 50, wherein the second case member 60 has a hole portion 61a that is inserted through to the outside, the first case member 20 has a first protrusion portion 23 that protrudes in a rib-like manner outside the display unit 40 and at a position facing the front surface 51, and a second protrusion portion 24 that protrudes in a rib-like manner at a position outside the first protrusion portion 23, the second case member 60 has an opposing surface portion 63a that faces the back surface 52, and the tip 24a of the second protrusion portion 24 is formed at a position beyond the front surface 51. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing a display device according to a first embodiment of the present disclosure, as viewed from the front side. [Figure 2] Cross-sectional view taken along line AA in Figure 1. [Figure 3] Cross-sectional view taken along line BB in Figure 1. [Figure 4] FIG. 3 is a cross-sectional view showing a display device according to a second embodiment of the display device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of a display device according to the present disclosure will be described with reference to the accompanying drawings. The display device according to the present disclosure is mounted on a vehicle such as an automobile or a motorcycle, a ship, an agricultural machine, or a construction machine. In this embodiment, the display device according to the present disclosure will be described using a display device mounted in an instrument panel of a vehicle as an example.

[0009] In the following description, "front (front face)", "rear (rear face)", "upper", "lower", "right", and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R", and "L" in Figures 1 to 4. Note that the side of the display device 100 that is visible to the user is defined as "front".

[0010] (First embodiment) 1 to 3, the display device 100 mainly includes a display unit (display section) 40 having a display surface 41 at the front, a circuit board 50 disposed behind the display unit 40 and fixing the display unit 40, an inner case 30 disposed in front of the circuit board 50 and housing the display unit 40, a lower case (second case member) 60 disposed behind the circuit board 50, an inside cover 20 (first case member) covering the front of the inner case 30, and a lens 10 covering the front of the inside cover 20.

[0011] The lens 10 is made of translucent inorganic glass or resin (for example, polymethyl methacrylate (PMMA)). The lens 10 covers the front of the end cover 20 and protects the inside from dust and the like.

[0012] The end cover 20 is made of a light-blocking synthetic resin (e.g., polypropylene resin) such as black. The end cover 20 is attached from the front to the lower case 60 at the back via a hook or the like, and houses the middle case 30, display unit 40, and circuit board 50 inside. The end cover 20 has a front surface 21, an upright wall 22, a first rib (first protrusion) 23, and a second rib (second protrusion) 24.

[0013] The front surface portion 21 is formed in a generally box-like shape with an open rear end, and covers the front of the middle case 30 and the lower case 60. The front surface portion 21 has a display opening 21a and an indicator opening 21b. The display opening 21a is a rectangular hole opened in a position facing the display surface 41 of the display unit 40. The indicator opening 21b is a hole opened in a position facing a plurality of design portions 71a of the display plate 70 described below. The standing wall portion 22 is formed in a generally cylindrical shape so as to surround the display opening 21a and the indicator opening 21b.

[0014] The first rib 23 is disposed outside the display unit 40 at a position facing the circuit board 50, and is formed in a rib-like shape so as to protrude toward the circuit board 50. The first rib 23 is formed at a position where the tip 23a does not abut against the front surface 51 of the circuit board 50, and the tip 23a has a gap G1 with the front surface 51.

[0015] The second ribs 24 are disposed outside the display unit 40 at a position not facing the circuit board 50, and are formed in a rib-like shape protruding toward the circuit board 50. The second ribs 24 are formed at a position outside the first ribs 23. The second ribs 24 are formed at a position where their tips 24a extend beyond the front surface 51 of the circuit board 50. In the present disclosure, the first ribs 23 and the second ribs 24 are formed within the range of line X1 above the display unit 40 shown in FIG. 1 and within the range of line X2 below the display unit 40.

[0016] The inner case 30 is made of a light-blocking synthetic resin (for example, polypropylene resin) such as white. The inner case 30 is disposed between the end cover 20 and the circuit board 50 and is placed on the circuit board 50. One inner case 30 is disposed on each side of the display unit 40. The inner case 30 has multiple cylindrical lighting chambers 31 that each house multiple light sources 53.

[0017] The display panel 70 is disposed between the middle case 30 and the front surface 21 of the endpaper 20 in front of the lighting chamber 31.

[0018] The display board 70 is made of a thin, flat base material made of translucent synthetic resin (such as polycarbonate). The display board 70 is formed by printing various inks, such as translucent, light-blocking, and light-diffusing inks, on its front and back. The display board 70 has multiple design portions 71a in the shape of warning lights or the like, which are formed by cutting and printing light-blocking ink 71. The design portions 71a are illuminated from behind by a light source 53, which will be described later, to emit light.

[0019] The display unit 40 has four bosses 42 that protrude cylindrically toward the circuit board 50. The display unit 40 is fixed to the circuit board 50 by inserting screws 80 from behind the circuit board 50. The display unit 40 has a display panel and a backlight unit, not shown.

[0020] The display panel is, for example, a TFT (Thin Film Transistor) liquid crystal display panel. The display panel is, for example, a large panel of 12 inches or more. The display panel has a display surface 41 on the front. The display panel has a pair of surface glass substrates that encapsulate a liquid crystal layer. Transparent electrodes are formed on the pair of glass substrates using ITO (Indium Tin Oxide) or the like. The display panel also has a pair of surface polarizers (polarizing filters) arranged to sandwich the pair of surface glass substrates.

[0021] The display panel is connected to the circuit board 50 via a flexible printed circuit (FPC (Flexible Printed Circuits)) not shown. The display panel is controlled by a control unit 54 of the circuit board 50, and a drive voltage is applied to the liquid crystal layer via the transparent electrodes. This controls the orientation of the liquid crystal molecules in the liquid crystal layer, and changes the transmittance of each pixel of the display panel, causing the display panel to display an image.

[0022] The backlight unit is provided behind the display panel. The backlight unit is made up of a light source substrate and a light guide, and illuminates the display panel from behind. The light source substrate is mounted with a plurality of LEDs (Light Emitting Diodes), which are an example of a light source. The light source substrate is connected to the circuit board 50 via a flexible substrate such as an FPC. When a driving current is supplied, the LEDs emit light toward the light guide. The light guide guides the light emitted by the LEDs toward the display panel. The light guide is formed into a flat plate and is made of transparent resin (e.g., PMMA).

[0023] The circuit board 50 is made of, for example, a rigid circuit board in which a copper foil pattern is arranged on a flat epoxy resin plate based on a predetermined electrical circuit. The circuit board 50 is formed in a substantially rectangular shape, and a rear surface 52 thereof is supported by the lower case 60. A front surface 51 of the circuit board 50 supports the inner case 30 and the display unit 40. A control unit 54 for controlling the display unit 40 is mounted on the rear surface 52 of the circuit board 50.

[0024] The control unit 54 has a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), GDC (Graphics Display Controller), etc., and executes predetermined arithmetic processing according to, for example, a program written in the ROM. The CPU, ROM, RAM, and GDC are made up of IC (Integrated Circuit) chips, and generate heat by consuming power. The control unit 54 acquires, for example, vehicle speed, engine RPM, various vehicle information, navigation information, etc. from the vehicle's ECU (Electronic Control Unit) via various sensors, etc. The control unit 54 displays information on the display unit 40 based on the acquired information.

[0025] The circuit board 50 has multiple connectors 55 on the back surface 52. Some of the connectors 55 penetrate the lower case 60 and are exposed, and are connected to cables (not shown) extending from the vehicle. The circuit board 50 has light sources 53 that illuminate the design portion 71a of the display panel 70. The light sources 53 are made of LEDs. Three light sources 53 are arranged on each side of the display unit 40.

[0026] The lower case 60 is made of a resin (e.g., polypropylene resin) in a black color or the like, and is formed in a generally box-like shape with an open front. The lower case 60 has a bottom surface 61, a side wall 62 extending forward from the outer periphery of the bottom surface 61 so as to cover the outer peripheries of the middle case 30, the display unit 40, and the circuit board 50, and a step 63.

[0027] The bottom surface 61 is formed to face the circuit board 50. The bottom surface 61 has ventilation holes (holes) 61a and acoustic member holes 61b. The ventilation holes 61a are provided to allow heat generated by the CPU, ROM, RAM, and GDC to escape to the outside. The acoustic member holes 61b are used to fix the speakers 90 with fixing means such as screws.

[0028] The speaker 90 is a visual information providing component that converts an audio output signal (electrical signal) into sound and emits voice or warning sounds. The speaker 90 is a disc-shaped electrodynamic speaker (cone speaker) that is composed of a magnetic circuit, a voice coil, a diaphragm, and a frame (not shown in detail). When a current is passed through the voice coil, a force acts on the voice coil, causing the diaphragm to vibrate in conjunction with the movement of the voice coil, thereby emitting sound. As shown in FIG. 2, a cord 91, which is an electric cord, is connected to the speaker 90. The cord 91 is connected to the connector 55 and is electrically connected to the circuit board 50.

[0029] The side wall portion 62 is formed to extend forward from the outer periphery of the bottom surface portion 61 to cover the outer peripheries of the inner case 30, the display unit 40, and the circuit board 50. The side wall portion 62 has mounting stays 62a. The mounting stays 62a are formed at the center position on the upper side and at left and right positions on the lower side. The display device 100 is fixed to the vehicle by inserting screws into the mounting stays 62a and fastening the screws to the vehicle's instrument panel.

[0030] The step portion 63 is formed by recessing one step inward (toward the circuit board 50) at the corner formed by the bottom surface portion 61 and the side wall portion 62. The step portion 63 has an opposing surface portion 63a and a lower side wall portion 63b.

[0031] The facing surface portion 63a extends inward from the side wall portion 62 and is formed to face the outer edge of the back surface 52 of the circuit board 50. The facing surface portion 63a faces the first rib 23 and the second rib 24 and is formed up to the outer edge of the circuit board 50 at a position facing the first rib 23 across the circuit board 50. There is a gap G2 between the facing surface portion 63a and the back surface 52. The facing surface portion 63a has ribs 63c at various locations and supports the circuit board 50. The side wall lower portion 63b extends forward from the outer periphery of the bottom surface portion 61 and is formed to connect with the inside of the facing surface portion 63a.

[0032] By forming it in this manner, as shown by line L1 in Fig. 3, gap G2 can prevent dust such as dirt that has entered the interior of display device 100 through ventilation hole 61a of lower case 60 from moving around the outer edge of circuit board 50 toward front surface 51 of circuit board 50. Even if dust passes through gap G2, it hits second rib 24 and falls toward back surface 52 of circuit board 50, as shown by line L2 in Fig. 3, and is therefore prevented from moving toward front surface 51.

[0033] Even if dust were to go over the second rib 24 and reach the front surface 51, it would hit the first rib 23 as shown by line L3 in Fig. 3, preventing it from moving toward the display unit 40. Even if dust were to go over the first rib 23, it would simply pass behind the display unit 40 as shown by line L4 in Fig. 3, reducing adhesion of the dust to the display surface 41 of the display unit 40.

[0034] In particular, gap G2 can have a larger facing area with respect to the circuit board 50 than gap G1. Furthermore, gap G1 cannot be made small because it is necessary to separate the first rib 23 from the circuit board 50 to prevent noise. In contrast, gap G2 can be set smaller than gap G1 because the facing surface portion 63a abuts against the circuit board 50 at various points via the ribs 63c. This allows gap G2 to be more effective at preventing dust from passing through than gap G1.

[0035] (Second embodiment) A second embodiment of a display device according to the present disclosure will be described with reference to Fig. 4. The same parts and equivalent portions as those in the first embodiment will be denoted by the same reference numerals.

[0036] The display device 200 does not have an end cover 20. The lens 10 of the display device 200 is formed in a roughly box shape with an open rear end, and covers the front of the middle case 30 and the lower case 60. The lens 10 has a light-shielding layer 11 on the front surface. The light-shielding layer 11 is made of a film printed with light-shielding ink, and has openings corresponding to the display opening 21a and the indicator opening 21b of the first embodiment.

[0037] The lens 10 has a lens rib 12 that corresponds to the second rib 24 of the first embodiment. The lens rib 12 is also disposed outside the display unit 40 at a position that does not face the circuit board 50, and is formed to protrude in a rib shape toward the circuit board 50. The lens rib 12 is formed outside an inner case rib 33, which will be described later. The lens rib 12 is formed at a position where a tip 12a extends beyond the front surface 51 of the circuit board 50.

[0038] The inner case 30 of the display device 200 has a connecting portion 32 that connects the left and right inner cases 30 to the outside of the display unit 40. The connecting portion 32 has an inner case rib 33 that corresponds to the first rib 23 of the first embodiment. The inner case rib 33 is also disposed outside the display unit 40 in a position facing the circuit board 50, and is formed to protrude in a rib-like shape toward the circuit board 50. The inner case rib 33 is formed in a position where its tip 33a does not abut against the front surface 51 of the circuit board 50, and there is a gap G3 between the tip 33a and the front surface 51.

[0039] The lower case 60 of the display device 200 does not have a step portion 63. The lower case 60 has a lower case rib 64. The lower case rib 64 is disposed in a position facing the circuit board 50, and is formed to protrude in a rib shape toward the circuit board 50. The lower case rib 64 is formed in a position where a tip 64a does not abut against the back surface 52 of the circuit board 50, and there is a gap G4 between the tip 64a and the back surface 52.

[0040] With this configuration, dust such as dirt that has entered the interior of the display device 100 through the ventilation holes 61a of the lower case 60 can be prevented from moving around the outer edge of the circuit board 50 toward the front surface 51 of the circuit board 50 by the lower case ribs 64 and lens rib 12. Even if the dust were to go beyond these ribs and reach the front surface 51, it would hit the middle case rib 33, preventing it from moving toward the display unit 40.

[0041] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0042] In the present disclosure, the first rib 23 and the second rib 24 are formed within the range of line X1 above the display unit 40 shown in FIG. 1 and within the range of line X2 below the display unit 40, but for example, they may be formed at least within the range of line X1, and it is also preferable to provide them around the entire circumference of the display unit 40. [Explanation of symbols]

[0043] 100,200 display devices 10 Lenses 11 Light blocking layer 12 Lens Rib 20 End cover (first case member) 21 Front part 21a Display opening 21b Indicator opening 22 Vertical wall 23 First rib (first protrusion) 23a tip 24 Second rib (second protrusion) 24a tip 30 Medium Case 31 Lighting Room 32 Joint 33 Middle case rib 40 Display unit (display section) 41 Display surface 50 Circuit Board 51 Front 52 Back 53 Light source 54 Control Unit 55 Connector 70 Display board 71 Ink 71a Design Department 60 Lower case (second case member) 61 Bottom part 61a Ventilation hole (hole) 62 Side wall 62a Mounting stay 63 Stepped section 63a Opposite surface part 63b Lower side wall 64 Lower case rib 90 Speaker 91 Code G1, G2, G3, G4, G5 gap

Claims

1. a display unit having a display surface; a flat circuit board disposed behind the display unit; a first case member that covers a front surface of the circuit board that faces the display unit; a second case member that covers the back surface of the circuit board, the second case member has a hole that is inserted into the outside, the first case member has a first protrusion formed in a rib shape at a position outside the display unit and facing the front surface, the second case member has an opposing surface portion that faces the rear surface, The display device is characterized in that the opposing surface portion has a gap between the rear surface and the opposing surface portion.

2. The display device according to claim 1 , wherein the first protrusion has a gap between itself and the front surface.

3. The display device according to claim 2 , wherein the facing surface portion is formed at a position facing the first protrusion portion.

4. A display device as described in Claim 2, characterized in that the gap of the opposing surface portion has a larger opposing area with the circuit board than the gap of the first protrusion portion and is set smaller than the gap of the first protrusion portion.

5. A display unit having a display surface; a flat circuit board disposed behind the display unit; a first case member that covers a front surface of the circuit board that faces the display unit; a second case member that covers the back surface of the circuit board, the second case member has a hole that is inserted into the outside, the first case member has a first protruding portion formed in a rib-like shape at a position outside the display portion and facing the front surface, and a second protruding portion formed in a rib-like shape at a position outside the first protruding portion, the second case member has an opposing surface portion that faces the rear surface, The display device is characterized in that the tip of the second protrusion is formed at a position that exceeds the front surface.

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