JP2022130892A - Display device - Google Patents

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

The present disclosure relates to a display device mounted on a vehicle or the like.

A display device mounted with an IC (Integrated Circuit) chip that generates a large amount of heat is provided with measures to dissipate heat. For example, there is known a display device in which a case for housing a circuit board has a ventilation hole and exchanges air between the inside and the outside of the case.

JP 2005-189453 A

In order to increase the cooling efficiency, it is conceivable to perform forced cooling by forcing air to flow inside the case. However, an IC chip or the like mounted on a circuit board may cause contact failure due to moisture contained in the air. In order to perform forced cooling, it is necessary to take measures against moisture in the circuit board, which complicates the manufacturing process.

The present disclosure has been made in consideration of such circumstances, and an object thereof is to provide a display device capable of achieving both cooling efficiency and manufacturing efficiency.

In order to solve the above-described problems, the display device of the present disclosure has a display section, a circuit board that controls the display section and emits heat, and has an inlet and an outlet for air, and isolates the display device from the circuit board. a heat sink having an air flow path for cooling the circuit board with the air flowing through the flow path.

In the display device of the present disclosure, both cooling efficiency and manufacturing efficiency can be achieved.

1 is a front perspective view of a display device that is an embodiment of the display device of the present disclosure; FIG. 1 is a rear perspective view of a display device that is an embodiment of the display device of the present disclosure; FIG. Sectional drawing which follows the III-III line of FIG. FIG. 4 is a view showing the display device from the rear with the rear cover removed; FIG. 4 is a cross-sectional view showing a display device as a first modified example corresponding to FIG. 3; The figure which shows the display apparatus as a 2nd modification from back in the state which removed the back cover. Sectional drawing which follows the VII-VII line of FIG. Sectional drawing which follows the VIII-VIII line of FIG. Sectional drawing which follows the IX-IX line of FIG. The figure which shows the display apparatus as a 3rd modification from back in the state which removed the back cover.

An embodiment of the display device of the present disclosure will be described based on the accompanying drawings. The display device of the present disclosure can be mounted, for example, on vehicles such as automobiles and motorcycles, ships, agricultural machinery, and construction machinery.

FIG. 1 is a front perspective view of a display device 1 that is an embodiment of the display device of the present disclosure.
FIG. 2 is a perspective view showing the 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 back cover 60 removed.

In the following description, "front (front)", "back (back)", "upper", "lower", "right", and "left" are defined as "Fr." Re.", "To.", "Bo.", "R", and "L".

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 back cover 60 (flow path cover).

The case 10 is made of, for example, metal (such as magnesium alloy or aluminum) or resin having high thermal conductivity, and supports the display unit 20 and the circuit board 30 . Further, the case 10 has a structure (not shown) to be fixed to, for example, an instrument panel of a vehicle. The case 10 has a bottom surface 11 and side surfaces 12 . The side surface 12 rises substantially vertically forward from the peripheral edge of the bottom surface 11 . The bottom surface 11 and side surfaces 12 have a space for accommodating the display unit 20 and an opening 15 for exposing the display unit 20 .

The case 10 has a circuit board housing wall 17 on the rear surface 11b of the bottom surface 11 facing rearward. The circuit board housing wall 17 is a closed standing wall that rises substantially vertically rearward from the rear surface 11 b and surrounds the circuit board 30 along substantially the outer edge of the circuit board 30 .

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 an LED (Light Emitting Diode) for illuminating the liquid crystal display element is mounted, and serves as a backlight for the liquid crystal display element. The light source substrate is arranged behind the liquid crystal display element. Further, the display unit 20 includes necessary members such as a light guide plate for spreading the light of the LED 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. have The display unit 20 is connected to the circuit board 30 via a flexible printed board (not shown).

The circuit board 30 is arranged in the circuit board housing wall 17 behind the case 10 so as to be substantially parallel to the rear surface 11b. The circuit board 30 is fixed to the bottom surface 11 with screws or the like. The circuit board 30 mainly has a control section 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 predetermined arithmetic processing according to a program written in the ROM, for example. The control unit acquires, for example, vehicle speed, engine speed, various vehicle information, navigation information, and the like from an ECU (Electronic Control Unit) of the vehicle via various sensors and the like. The control unit causes the display unit 20 to display information based on the acquired information. The control unit is an IC chip 31 called a so-called GDC (Graphics Display Controller) that controls the display unit 20, and is a heating element that generates relatively high heat. Therefore, the circuit board 30 generates heat and requires heat generating means. The IC chip 31 is mounted on the rear-facing surface of the circuit board 30 .

The protective cover 40 is a translucent plate member (for example, inorganic glass, polycarbonate resin, PMMA resin). The protective cover 40 protects the display unit 20 inside the case 10 from dust and the like by covering the opening 15 of the case 10 . The protective cover 40 is adhered to the front surface of the display unit 20 by optical bonding with a translucent adhesive.

The heat sink 50 is integrally formed with the case 10 and arranged behind the case 10 . Like the case, the heat sink 50 is made of, for example, metal (magnesium alloy or aluminum). The heat sink 50 has a plurality of fins 55 that rise substantially vertically from the rear surface 11b other than the area where the circuit board 30 is arranged. For example, four fins 55 are formed at predetermined intervals in the direction away from the outer edge of the circuit board 30 . A plurality of 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 extending upward from the lower left side of the back surface 11b, a second side 52 that bends to the right from the first side 51 and further extends, and a second side 52 that extends from the second side 52. and a third side 53 that bends downward and further extends.

Each fin 55 is a flow path for air, with an air inlet 56 at the lower end of the first side 51 and an air outlet 57 at the lower end of the third side 53 . At this time, 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 fins 55a arranged closest to the circuit board 30 side. Inlet 56 is connected with duct 58 . The duct 58 forcibly sends the air blown from the vehicle to which the display device 1 is attached to the flow path. As a result, the space between the fins 55 and the space between the fins 55 a located closest to the circuit board 30 and the circuit board housing wall 17 form air flow paths while being isolated from the circuit board 30 .

The rear cover 60 is made of, for example, metal or resin (electrogalvanized steel plate, ABS resin, thermoplastic resin, etc.). The rear cover 60 has a channel side cover 61 and a circuit board side cover 62 which are integrally molded to cover the circuit board 30 together with the channel. 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 hooks.

As shown in FIG. 3, the channel-side cover 61 covers and closes the channel from behind by coming into contact with the tip 59 (rear end) of each fin 55 . As a result, the channel-side cover 61 prevents the air flowing through the channel from escaping from behind.

The circuit board side cover 62 covers the circuit board 30 from behind. The circuit board side cover 62 conforms to the shape of the circuit board housing wall 17 , faces and contacts the tip 18 , and forms a closed space together with the circuit board housing 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-conducting member 63 .

In the display device 1 configured in this manner, the circuit board 30 (IC chip 31) is cooled even when forced cooling using air blown from a vehicle is used to improve the cooling efficiency. Air humidity countermeasures for 30 can be dispensed with. That is, in the display device 1, since the air flow path is formed separately from the circuit board 30, the circuit board 30 does not need to be protected against humidity. Specifically, the display device 1 can eliminate the need to apply a moisture-resistant coating to the circuit board 30 or arrange a porous film or the like that allows air to pass through but does not allow water to pass through. Cost can be reduced.

In addition, since the display device 1 covers each channel with the back cover 60, the air blown into the channel can be guided to the outlet 57 without leaking.

Furthermore, in the display device 1, the channel side cover 61 and the circuit board side cover 62 are integrally formed. Can be efficiently cooled with air. Moreover, since the circuit board side cover 62 and the flow path side cover 61 are integrally molded in the display device 1, the number of parts can be reduced.

Furthermore, since the light source substrate of the display unit 20 is in thermal contact with the bottom surface 11 of the case 10, the light source substrate is efficiently cooled by the air flowing through the flow path, similarly to the circuit substrate 30.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

For example, the rear cover 60 has been described as an example in which the channel-side cover 61 and the circuit board-side cover 62 are integrally molded, but may be divided into a plurality of parts. When the rear cover 60 is divided, it is not limited to the case where it is divided into the circuit board side cover 62 and the channel side cover 61, and the circuit board side cover 62 and part of the channel side cover 61 may be integrally molded. Yes, the other part of the flow path side cover 61 may be divided like separate parts. Moreover, a part of the rear cover 60 is not limited to a member such as resin, and may be formed of another member such as a resin sheet.

Further, since the air on the inlet 56 side flows to the outlet 57 side while being cooled, it 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. In FIGS. 5 to 10, the same reference numerals are given to the configurations and parts corresponding to those of the display device 1, and redundant explanations are omitted.

While each fin 55 of the display device 1 has the same height, in the display device 101, the fin 155a (the circuit board housing wall 17) closest to the circuit board 30 is described as the fin 155a for convenience of explanation. ) and the fin 155b farthest from the circuit board 30, and the fins 155c, 155d, and 155e between the pair of fins 155a and 155b facing the outermost sides of the flow path are the pair of fins facing the outermost sides of the flow path. fins 155a and 155b. As a result, the surface areas of the fins 155c, 155d, and 155e are reduced, and thus the cooling efficiency is lowered.

FIG. 6 is a rear view of the display device 201 as a second modification with the back cover 60 removed. FIG. 7 is a cross-sectional view along line VII-VII of FIG. FIG. 8 is a cross-sectional view taken along line VIII--VIII of FIG. 9 is a cross-sectional view along line IX-IX in FIG. 6. FIG.

In the display device 201, a pair of fins 255a facing the outermost side of the flow path (the circuit board housing wall 17 is described as fins 255a for convenience of explanation), and fins 255c, 255d, and 255e between 255b. , has a gradually increasing height from the inlet 56 to the outlet 57 . As a result, the surface area of the fins 255c, 255d, and 255e on the side of the inlet 56 is small, and the surface area of the fins 255c, 255d, and 255e on the side of the outlet 57 is large. However, the air on the side of the outlet 57 is sent to the side of the outlet 57 with a lower temperature than when the fins 55 have a uniform height and can be cooled by the fins 255c, 255d, and 255e with a large surface area. side cooling efficiency can be improved.

At least some of the fins 155c, 155d, and 155e may be smaller in height than the pair of fins 155a and 155b facing the outermost side of the channel in the display device 101. FIG. At least some of the fins 255c, 255d, and 255e may be fins that gradually increase in height from the entrance 56 to the exit 57 in the display device 201. FIG.

Moreover, as means for further improving the cooling efficiency, the heat sink 50 may further include a channel for guiding part of the air flowing through the channel to the circuit board 30 . FIG. 10 is a rear view of the display device 301 as the third modification with the back cover 60 removed.

In the display device 301, the flow formed by the fin 355a closest to the circuit board 30 (the circuit board housing wall 17 is described as the fin 355a for convenience of explanation) and the fin 355b second closest to the circuit board 30. The channels have inlet openings 317a and outlet openings 317b, thereby forming branched flow paths. The entrance opening 317 a is formed near the IC chip 31 , for example, and the exit opening 317 b is formed near the exit 57 . Further, the back cover 60 has a flow path wall 64 protruding toward the circuit board 30 on the circuit board side cover 62 . The channel wall 64 protrudes toward the circuit board 30 with a gap provided so as not to interfere with the circuit board 30 and components arranged on the circuit board 30 . The channel wall 64 is formed of a pair of walls so that the IC chip 31 passes from the inlet opening 317a to the outlet opening 317b.

As a result, the branch flow path allows air to flow from the vicinity of the IC chip 31 to the vicinity of the outlet 57 toward the circuit board 30, thereby directly cooling the circuit board 30 with the air. The air that cools the circuit board 30 and reaches the outlet opening 317b returns to the channel formed by the fins 355a and 355b, and is discharged from the outlet 57 together with the air that flows through the channel formed by the other fins 355. .

In this case, although a moisture-resistant coating or the like is required for the circuit board 30, the circuit board 30 can be cooled by slightly changing the flow path and forming the inlet opening 317a and the outlet opening 317b without adding a completely separate structure. can improve performance. In addition, depending on the position of the inlet opening 317a, it is possible to send air to a desired location, so it is possible to reduce the excessive application of moisture to objects other than the object to be cooled.

1, 101, 201, 301 display device 10 case 11 bottom surface 11b rear surface 12 side surface 15 opening 17 circuit board housing wall 18 tip 20 display unit (display section)
30 circuit board 31 IC chip 40 protective cover 50 heat sink 51 first side 52 second side 53 third side 55, 55a fin 56 inlet 57 outlet 58 duct 59 tip 60 back cover (flow path cover)
61 channel side cover 62 circuit board side cover 63 heat conducting member 64 channel walls 155a, 155b, 155c, 155d, 155e fins 255a, 255c, 255d, 255e fins 317a inlet openings 317b outlet openings 355, 355a, 355b fins

Claims (8)

a display unit;
a circuit board that controls the display unit and generates heat;
A display device comprising: a heat sink that has a flow path that has an air inlet and an air outlet and that allows the air to flow while being isolated from the circuit board, and that cools the circuit board with the air that flows through the flow path. 2. The display device according to claim 1, further comprising a channel cover that covers said channel. further comprising a case that has a back surface that opens forward and faces backward, and that houses the display unit;
the circuit board and the heat sink are disposed on the back surface of the case;
3. The display device according to claim 2, wherein the channel cover covers the circuit board together with the channel from behind. 4. The display device according to claim 3, wherein said channel cover is thermally connected to said circuit board. The circuit board is arranged substantially parallel to the back surface of the case,
4. The display device according to claim 3, wherein said heat sink has a plurality of fins which rise substantially vertically from said back surface other than the area where said circuit board is arranged and which form said flow path along the outer edge of said circuit board. 6. The display device according to claim 5, wherein at least a portion of the fins between the pair of fins facing the outermost side of the channel has a smaller height than the pair of fins facing the outermost side of the channel. 6. A display device according to claim 5, wherein at least some of the fins between the pair of outermost fins of the channel have a height that increases from the inlet to the outlet. 2. The display device according to claim 1, wherein said heat sink further comprises a branch channel for guiding part of said air flowing through said channel to said circuit board.

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