Display device

Abstract

To provide a display device that can achieve both cooling efficiency and manufacturing efficiency.SOLUTION: A display device 1 according to an embodiment includes a display unit 20, a circuit board 30 that controls the display unit 20 and emits heat, and a heat sink 50 including a flow channel with an inlet and an outlet for air where air flows at a distance from the circuit board 30 and cooling the circuit board 30 with the air flowing in the flow channel. In addition, the display device 1 includes a rear face cover 60 that covers the flow channel, and a rear face 11b that opens forward and faces backward, and further includes a case 10 that accommodates the display unit 20. The circuit board 30 and the heat sink 50 are disposed on the rear face 11b of the case 10, and the rear face cover 60 covers the flow channel and the circuit board 30 from the back.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a display device mounted on a vehicle or the like. [Background technology]

[0002] Display devices equipped with IC (Integrated Circuit) chips that generate a large amount of heat are provided with heat dissipation measures. For example, a display device is known in which the case housing the circuit board has ventilation holes to exchange air between the inside and outside of the case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-189453 A Summary of the Invention [Problem to be solved by the invention]

[0004] To improve the cooling efficiency, it is possible to use forced cooling, which forces air to flow inside the case. However, there is a risk that moisture in the air may cause contact problems with the IC chips mounted on the circuit board. In order to use forced cooling, measures must be taken to protect the circuit board from moisture, which complicates the manufacturing process.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a display device that can achieve both cooling efficiency and manufacturing efficiency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the display device of the present disclosure includes a display unit, a circuit board that controls the display unit and generates heat, and a heat sink that has an air inlet and outlet, has a flow path through which the air flows while being isolated from the circuit board, and cools the circuit board with the air flowing through the flow path; The device comprises a flow path cover that covers the flow path, and a case that has an opening at the front and a rear surface facing rear and that houses the display unit, the circuit board and the heat sink are arranged at the rear surface of the case, and the flow path cover covers the circuit board from the rear together with the flow path. Effect of the Invention

[0007] In the display device of the present disclosure, both cooling efficiency and manufacturing efficiency can be achieved. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a display device according to an embodiment of the present disclosure, viewed from the front. [Diagram 2] 1 is a perspective view showing a display device according to an embodiment of the present disclosure, viewed from the rear. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 2 is a diagram showing the display device from the rear with the rear cover removed. [Diagram 5] FIG. 4 is a cross-sectional view showing a display device as a first modified example corresponding to FIG. 3. [Figure 6] FIG. 13 is a rear view of a display device according to a second modified example with the rear cover removed. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6 . [Figure 9] FIG. 7 is a cross-sectional view taken along line IX-IX in FIG. 6. [Figure 10] FIG. 13 is a diagram showing a display device as a third modified example from the rear with the rear cover removed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 can be mounted on vehicles such as automobiles and motorcycles, ships, agricultural machinery, and construction machinery.

[0010] FIG. 1 is a perspective view showing, from the front, a display device 1 which is an embodiment of the display device of the present disclosure. FIG. 2 is a perspective view showing a display device 1, which is an embodiment of the display device of the present disclosure, from the rear. FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a rear view of the display device 1 with the rear cover 60 removed.

[0011] In the following description, "front," "back," "upper," "lower," "right," and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R," and "L" in Figures 1 to 10.

[0012] The display device 1 mainly includes a case 10, a display unit 20 (display section), a circuit board 30, a protective cover 40, a heat sink 50, and a rear cover 60 (passage cover).

[0013] Case 10 is made of, for example, a metal (e.g., magnesium alloy or aluminum) or a resin with high thermal conductivity, and supports display unit 20 and circuit board 30. Case 10 also has a structure for being fixed to, for example, a vehicle instrument panel (not shown). Case 10 has a bottom surface 11 and side surfaces 12. Side surfaces 12 rise approximately vertically forward from the periphery of bottom surface 11. Bottom surface 11 and side surfaces 12 have a space for accommodating display unit 20 and an opening 15 for exposing display unit 20.

[0014] The case 10 has a circuit board accommodating wall 17 on a back surface 11b, which is the surface facing rearward of the bottom surface 11. The circuit board accommodating wall 17 is a closed standing wall that rises rearward substantially vertically from the back surface 11b and surrounds the circuit board 30 along substantially the outer edge of the circuit board 30.

[0015] The display unit 20 has a liquid crystal display element and a light source substrate. The liquid crystal display element is, for example, a TFT (Thin Film Transistor) type liquid crystal display panel formed by sealing liquid crystal molecules between a pair of glass substrates. The light source substrate is, for example, a substrate on which LEDs (Light Emitting Diodes) for illuminating the liquid crystal display element are mounted, and serves as a backlight for the liquid crystal display element. The light source substrate is disposed behind the liquid crystal display element. The display unit 20 also has necessary members such as a light guide plate for dispersing the light of the LEDs over the entire surface of the liquid crystal display element, a reflector provided behind the light guide plate, and a diffusion plate provided in front of the light guide plate. The display unit 20 is connected to the circuit board 30 by a flexible printed circuit board (not shown).

[0016] The circuit board 30 is disposed in the circuit board housing wall 17 so as to be approximately parallel to the rear surface 11b at the rear of the case 10. The circuit board 30 is fixed to the bottom surface 11 by screws or the like. The circuit board 30 mainly has a control unit for controlling the display unit 20. The control unit has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and executes a predetermined arithmetic processing according to a program written in the ROM, for example. The control unit 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 causes the display unit 20 to display information based on the acquired information. The control unit is an IC chip 31, so-called a GDC (Graphics Display Controller), which controls the display unit 20, and is a heat generating body that generates relatively high heat. For this reason, the circuit board 30 requires a heat generating means to generate heat. The IC chip 31 is mounted on the surface of the circuit board 30 facing the rear.

[0017] The protective cover 40 is a plate-like member having translucency (e.g., inorganic glass, polycarbonate resin, PMMA resin). The protective cover 40 covers the opening 15 of the case 10, thereby protecting the display unit 20 inside the case 10 from dust and the like. The protective cover 40 is optically bonded to the front surface of the display unit 20 with a translucent adhesive.

[0018] The heat sink 50 is disposed behind the case 10 and is formed integrally with the case 10. The heat sink 50 is made of, for example, a metal (magnesium alloy or aluminum) like the case. The heat sink 50 has a plurality of fins 55 that rise up substantially vertically from the rear surface 11b other than the area where the circuit board 30 is disposed. For example, four fins 55 are formed at predetermined intervals in a direction away from the outer edge of the circuit board 30. The multiple fins 55 extend along the outer edges of three sides of the circuit board 30. That is, as shown in FIG. 4, each fin 55 has a first side 51 that extends upward from the lower left of the rear surface 11b, a second side 52 that bends to the right from the first side 51 and further extends, and a third side 53 that bends downward from the second side 52 and further extends.

[0019] Each fin 55 is a flow path for air, with the lower end of the first side 51 serving as an air inlet 56 and the lower end of the third side 53 serving as an air outlet 57. At this time, the three sides of the circuit board housing wall 17 parallel to the first side 51, the second side 52, and the third side 53 form a flow path together with the fin 55a arranged closest to the circuit board 30. The inlet 56 is connected to a duct 58. The duct 58 forcibly sends air blown from the vehicle to which the display device 1 is attached to the flow path. As a result, the spaces between the fins 55 and between the fin 55a arranged closest to the circuit board 30 and the circuit board housing wall 17 become flow paths for air to flow while being isolated from the circuit board 30.

[0020] The rear cover 60 is made of, for example, metal or resin (electrolytic galvanized steel sheet, ABS resin, thermoplastic resin, etc.). The rear cover 60 has a flow path side cover 61 and a circuit board side cover 62, which are formed as an integrally molded product and cover the flow path and the circuit board 30. The rear cover 60 is detachably fixed to the circuit board housing wall 17, the fins 55, and the case 10 by a fixing structure such as a hook.

[0021] 3, the flow path side cover 61 covers and closes the flow path from the rear by contacting the tips 59 (rear ends) of each fin 55. In this way, the flow path side cover 61 prevents the air flowing through the flow path from escaping from the rear.

[0022] The circuit board side cover 62 covers the circuit board 30 from the rear. The circuit board side cover 62 matches the shape of the circuit board accommodating wall 17, faces the tip 18, and forms a closed space together with the circuit board accommodating wall 17. The circuit board 30 is accommodated in this closed space. The circuit board side cover 62 is thermally connected to the IC chip 31, which is a heat generating member of the circuit board 30, by a heat conductive member 63.

[0023] The display device 1 configured in this manner can eliminate the need for measures against moisture in the air for the circuit board 30, even when cooling the circuit board 30 (IC chip 31) by using forced cooling using air blown from a vehicle to improve cooling efficiency. That is, since the display device 1 is formed by isolating the air flow path from the circuit board 30, it can eliminate the need for measures against moisture for the circuit board 30. Specifically, the display device 1 can eliminate the need for providing a moisture-resistant coating on the circuit board 30 or arranging a porous film or the like that allows air to pass but not moisture to pass therethrough, thereby reducing the manufacturing process and manufacturing costs.

[0024] Furthermore, in the display device 1, each flow path is covered with the rear cover 60, so that the air blown into the flow path can be guided to the outlet 57 without leaking.

[0025] Furthermore, since the display device 1 has the flow path side cover 61 and the circuit board side cover 62 molded as an integral part, the heat of the IC chip 31 transmitted from the thermal conductive member 63 can be efficiently cooled by the air flowing through the flow path by being transmitted to the flow path side cover 61. Furthermore, since the display device 1 has the circuit board side cover 62 and the flow path side cover 61 molded as an integral part, the number of parts can be reduced.

[0026] Furthermore, the light source board of the display unit 20 is in thermal contact with the bottom surface 11 of the case 10, so that, like the circuit board 30, the light source board is also efficiently cooled by the air flowing through the flow path.

[0027] Although some 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 implemented 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 in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0028] For example, the rear cover 60 may be divided into a plurality of parts, although the flow path side cover 61 and the circuit board side cover 62 are an integrally molded product in the above example. When the rear cover 60 is divided, it is not limited to the case where the rear cover 60 is divided into the circuit board side cover 62 and the flow path side cover 61, but the circuit board side cover 62 and a part of the flow path side cover 61 may be an integrally molded product, and the other part of the flow path side cover 61 may be divided as a separate part. Furthermore, the part of the rear cover 60 is not limited to being made of a material such as resin, and may be made of a separate material such as a resin sheet.

[0029] Moreover, the air on the inlet 56 side flows to the outlet 57 side while being cooled, and therefore flows while being heated. Therefore, the cooling efficiency on the outlet 57 side is lower than that on the inlet 56 side. Therefore, the cooling efficiency on the inlet 56 side and the outlet 57 side may be controlled by changing the height of the fins 55. FIG. 5 is a cross-sectional view showing a display device 101 as a first modified example corresponding to FIG. 3. In FIG. 5 to FIG. 10, the same reference numerals are used for configurations and parts corresponding to the display device 1, and duplicated explanations will be omitted.

[0030] While the fins 55 of the display device 1 have the same height, in the display device 101, the fin 155a closest to the circuit board 30 (which is the circuit board housing wall 17, but will be described as fin 155a for convenience of explanation) and the fin 155b furthest from the circuit board 30, the fins 155c, 155d, and 155e between the pair of fins 155a and 155b facing the outermost side of the flow path, are shorter in height than the pair of fins 155a and 155b facing the outermost side of the flow path. As a result, the surface area of ​​the fins 155c, 155d, and 155e is reduced, and thus the cooling efficiency is reduced, but the air is sent to the outlet 57 side at a lower temperature than when the fins 55 have uniform height.

[0031] Fig. 6 is a rear view of a display device 201 as a second modified example with the rear cover 60 removed. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 6. Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 6.

[0032] In the display device 201, the fins 255c, 255d, and 255e between a pair of fins 255a (which are the circuit board housing wall 17 but will be described as fins 255a for convenience of explanation) and 255b facing the outermost side of the flow path have heights that gradually increase from the inlet 56 to the outlet 57. As a result, the surface area of ​​the fins 255c, 255d, and 255e on the inlet 56 side is small and the surface area of ​​the fins 255c, 255d, and 255e on the outlet 57 side is large, so that like the display device 101, the cooling efficiency on the inlet 56 side is reduced, but the air on the outlet 57 side is sent to the outlet 57 side at a lower temperature than in the case where the fins 55 have a uniform height, and can be cooled by the fins 255c, 255d, and 255e with a large surface area, so that the cooling efficiency on the outlet side can be improved.

[0033] The fins having a height smaller than that of the pair of fins 155a, 155b facing the outermost side of the flow path in the display device 101 may be at least a part of the fins 155c, 155d, and 155e. The fins having a height that gradually increases from the inlet 56 to the outlet 57 in the display device 201 may be at least a part of the fins 255c, 255d, and 255e.

[0034] As a means for further improving the cooling efficiency, the heat sink 50 may further include a flow path that guides a portion of the air flowing through the flow path to the circuit board 30. Fig. 10 is a rear view of a display device 301 as a third modified example with the rear cover 60 removed.

[0035] In the display device 301, a flow path formed by the fin 355a (which is the circuit board housing wall 17 but will be described as the fin 355a for convenience of explanation) closest to the circuit board 30 and the fin 355b second closest to the circuit board 30 has an inlet opening 317a and an outlet opening 317b, thereby forming a branch flow path. The inlet opening 317a is formed, for example, near the IC chip 31, and the outlet opening 317b is formed near the outlet 57. In addition, the rear cover 60 has a flow path wall 64 protruding toward the circuit board 30 side on the circuit board side cover 62. The flow path wall 64 protrudes toward the circuit board 30 side with a gap provided so as not to interfere with the circuit board 30 and the components arranged on the circuit board 30. The flow path wall 64 is formed by a pair of walls from the inlet opening 317a to the outlet opening 317b via the IC chip 31. As a result, the branch flow path allows air to flow from the vicinity of IC chip 31 to the vicinity of outlet 57 toward circuit board 30, and the air directly cools circuit board 30. The air that has cooled circuit board 30 and reached outlet opening 317b returns to the flow path formed by fins 355a and 355b, and is discharged from outlet 57 together with the air flowing through the flow path formed by the other fins 355.

[0036] In this case, a moisture-resistant coating or the like is required for the circuit board 30, but the cooling performance of the circuit board 30 can be improved by slightly modifying the flow path and forming the inlet opening 317a and the outlet opening 317b without adding a completely separate structure. In addition, since air can be sent to a desired location depending on the position of the inlet opening 317a, it is possible to reduce the unnecessary exposure of moisture to objects other than those being cooled. [Explanation of symbols]

[0037] 1, 101, 201, 301 Display device 10 Cases 11 Bottom 11b Back 12 Side 15 Aperture 17 Circuit Board Housing Wall 18 Tip 20 Display unit (display section) 30 Circuit Board 31 IC chip 40 Protective cover 50 Heatsink 51 First Side 52 Second Side 53 Third Side 55, 55a fins 56 Entrance 57 Exit 58 Duct 59 Tip 60 Rear cover (flow passage cover) 61 Flow passage side cover 62 Circuit board side cover 63 Thermal Conductive Materials 64 Channel Wall 155a, 155b, 155c, 155d, 155e Fins 255a, 255c, 255d, 255e Fins 317a Entrance opening 317b Exit opening 355, 355a, 355b Fins

Claims

1. A display unit; A circuit board that controls the display unit and generates heat; a heat sink having an air inlet and an outlet, a flow path through which the air flows while being isolated from the circuit board, and the heat sink cools the circuit board with the air flowing through the flow path; A flow path cover that covers the flow path; a case having an opening toward the front and a rear surface facing rearward, the case housing the display unit; the circuit board and the heat sink are disposed on the rear surface of the case; The flow path cover covers the flow path and the circuit board from behind.

2. The display device according to claim 1 , wherein the flow passage cover is thermally connected to the circuit board.

3. the circuit board is disposed substantially parallel to the rear surface of the case; The display device according to claim 1 , wherein the heat sink has a plurality of fins that rise substantially perpendicularly from the rear surface other than the area where the circuit board is disposed and form the flow path along an outer edge of the circuit board.

4. The display device according to claim 3 , wherein at least a portion of the fins between a pair of fins facing the outermost sides of the flow path has a height smaller than that of the pair of fins facing the outermost sides of the flow path.

5. The display device according to claim 3 , wherein at least a portion of the fins between a pair of fins facing the outermost sides of the flow channel has a height that increases from the inlet to the outlet.

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