JP7443930B2 - Vehicle display device and method for manufacturing vehicle display device - Google Patents

Description

The present disclosure relates to a vehicle display device and a method of manufacturing the vehicle display device.

As a conventional vehicle display device, there is one described in Patent Document 1. The vehicle display device described in Patent Document 1 includes a metal case and a circuit board fixed to the bottom surface of the case and mounting an LED (Light Emitting Diode). The vehicle display device described in Patent Document 1 ensures heat dissipation by a heat dissipation sheet provided between a circuit board, which is a heat generating body, and the bottom surface of a case.

JP 2017-126468 Publication

When ensuring heat dissipation, instead of using a heat dissipation sheet as described above, a heat dissipation agent such as heat dissipation grease may be filled between the heating element and the case. In this case, before assembling the heat generating element into the case, it is necessary to apply a heat dissipating agent to the case or the heat generating element in advance, which may impose restrictions on the assembly procedure.

The present disclosure has been made in view of the above circumstances, and aims to provide a vehicle display device that is easy to assemble and a method for manufacturing the vehicle display device.

In order to achieve the above object, a vehicle display device according to a first aspect of the present disclosure includes:
A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element and a bottom portion in which a through hole is formed ,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The wall portion has a groove recessed in a direction away from the heating element, and stands from the bottom toward the opening,
The groove connects the injection port and the through hole, and extends from the injection port toward the bottom.

In order to achieve the above object, a vehicle display device according to a second aspect of the present disclosure includes:
A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element and a bottom portion,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The wall portion has a groove recessed in a direction away from the heating element, and a flat portion adjacent to the groove, and stands from the bottom portion toward the opening,
The groove is connected to the injection port and extends from the injection port toward the bottom,
The heat dissipating agent is filled inside the groove recessed with respect to the flat portion and between the flat portion and the heating element.
Further, in order to achieve the above object, a vehicle display device according to a third aspect of the present disclosure includes :
A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The inner surface portion is formed into a mortar shape.

According to the present disclosure, it is possible to provide a vehicle display device with good assemblability and a method of manufacturing the vehicle display device.

FIG. 1 is a diagram showing how a vehicle display device is mounted according to an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the vehicle display device according to the embodiment. FIG. 3 is an enlarged view of section A shown in FIG. 2. 4 is a schematic cross-sectional view of the case and the first light source substrate taken along line BB shown in FIG. 3. FIG. FIG. 3 is an enlarged perspective view of the main parts of the case according to the embodiment. FIG. 3 is a schematic diagram for explaining a heat dissipation section according to the embodiment same as above.

An embodiment of the present disclosure will be described with reference to the drawings.

The vehicle display device according to the present embodiment is a head-up display (HUD) device 100 that is provided in an instrument panel of a vehicle, and as shown in FIG. 1, emits display light DL representing an image onto a windshield WS of the vehicle. It is. The image represented by the display light DL shows vehicle information such as traveling speed, various warnings, route guidance, etc., for example. When the vehicle passenger (viewer) Vr looks at the windshield WS from the eyebox EB, he or she can see the virtual image Vi of the image represented by the display light DL in front of the windshield WS.

Below, each structure may be explained using the left and right, up and down, and front and rear directions of the vehicle. In each figure, an X-axis along the left-right direction, a Y-axis along the up-down direction, and a Z-axis along the front-back direction are shown. Note that the arrow indicating the X axis points to the right, the arrow indicating the Y axis points upward, and the arrow indicating the Z axis points backward.

As shown in FIG. 1, the HUD device 100 includes a display 10, a reflective section 20, and a housing section 30 that accommodates the display 10 and the reflective section 20. As shown in FIG. 2, the housing section 30 includes a case 40 and a cover 50 that covers the case 40 from below. Note that FIG. 2 is an exploded perspective view of the HUD device 100 when viewed from below. Further, the HUD device 100 includes a heat dissipating agent 60 shown in FIG. 6 and a control section not shown.

The display device 10 generates display light DL by spatially modulating the light emitted from each of a plurality of LEDs (Light Emitting Diodes) using a DMD (Digital Micromirror Device), for example. The plurality of LEDs are composed of a red LED, a green LED, and a blue LED, and are driven by the control section in a field sequential manner.

As shown in FIG. 2, the display 10 includes a frame 10a, and a first light source substrate 11, a second light source substrate 12, and a third light source substrate 13 supported by the frame 10a. The first light source substrate 11, the second light source substrate 12, and the third light source substrate 13 are composed of PCBs (Printed Circuit Boards) on which LEDs of different emission colors are mounted. For example, the first light source substrate 11 includes a blue LED, the second light source substrate 12 includes a red LED, and the second light source substrate 13 includes a green LED.

The reflecting section 20 shown in FIG. 1 is made of, for example, a concave mirror, and reflects the display light DL emitted by the display device 10 toward the windshield WS.

A control unit (not shown) includes a microcomputer that controls the overall operation of the HUD device 100. The control unit communicates with a system such as an ECU (Electronic Control Unit) that controls each part of the vehicle, and drives the display 10 via a display control driver.

The case 40 is made of metal and has a box shape. As shown in FIG. 2, the case 40 has an opening 40a formed therein. This opening 40a opens toward the bottom of the case 40 when the HUD device 100 is mounted on a vehicle as shown in FIG. The display 10 is housed inside the case 40. The display 10 is inserted into the case 40 through the opening 40a and assembled. A storage chamber that accommodates the reflection section 20 is formed on the upper side (not shown) of the case 40, and an upper cover that covers the storage chamber from above is attached. The upper cover includes a cover glass that transmits the display light DL reflected by the reflection section 20 toward the windshield WS. The main structure of the case 40 will be described later.

The cover 50 is made of metal and closes the opening 40a of the case 40. That is, when the HUD device 100 is mounted on a vehicle as shown in FIG. 1, the cover 50 constitutes the lower end of the housing section 30. A heat sink 51 having a plurality of radiation fins is formed on the cover 50.

From here, the main structure of the case 40 and the heat dissipating agent 60 will be explained.

As shown in FIGS. 3 to 5, the case 40 includes a wall portion 41 facing the first light source substrate 11, which is an example of a heating element, and a bottom portion 42 to which the frame 10a of the display device 10 is fixed. . When the HUD device 100 is mounted on a vehicle as shown in FIG. 1, the bottom portion 42 is located above the display device 10. The wall portion 41 is provided so as to stand from the bottom portion 42 toward the opening 40a (that is, toward the bottom). Note that FIG. 4 schematically shows the frame 10a. Further, although not shown, the LED provided in the first light source substrate 11 is mounted on the back surface of the surface facing the wall portion 41 of the substrate.

As shown in FIG. 5, the wall portion 41 mainly includes an injection port 410 and an injection port 410 for injecting a heat dissipating agent 60 (see FIG. 6) into the gap between the first light source substrate 11 and the wall portion 41. It has a connecting groove 411 and a flat portion 412.

The injection port 410 is provided at the end of the wall portion 41 facing the opening 40a. The injection port 410 has an inner surface portion 410a that is depressed in a direction away from the first light source substrate 11. The inner surface portion 410a is formed into a mortar shape that tapers toward the groove 411.

The groove 411 is recessed in a direction away from the first light source substrate 11 and is formed to extend from the injection port 410 toward the bottom 42 . As shown in FIG. 5, the groove 411 has a shape that tapers from the injection port 410 toward the bottom portion 42. As shown in FIG. The groove 411 connects the injection port 410 and the through hole 42a formed in the bottom 42. The through hole 42a passes through the bottom portion 42 in the Y direction.

The flat portion 412 is formed in a portion adjacent to the groove 411. The groove 411 is recessed relative to the flat portion 412 . Specifically, the flat portions 412 are formed in a region of the wall portion 41 on the bottom portion 42 side, and are located on both sides with the groove 411 in between. A depressed portion 413 that is depressed from the flat portion 412 is formed in the wall portion 41 closer to the injection port 410a than the flat portion 412 . The depressed portions 413 are also located on both sides of the groove 411.

A rib 414 that protrudes toward the first light source substrate 11 is formed between the groove 411 and the recessed portion 413 . That is, the groove 411 is located between the pair of ribs 414. As shown in FIG. 3, the pair of ribs 414 are formed so that the distance between them increases toward the first light source substrate 11. Thereby, the heat dissipating agent 60 injected as described later flows so as to spread in the surface direction of the first light source substrate 11. In other words, depending on the shape of the ribs 414, the flow of the heat dissipating agent 60 during injection can be controlled.

The heat dissipating agent 60 is called heat dissipating grease, thermal paste, or the like. The heat dissipating agent 60 of this embodiment is made by mixing aluminum nitride particles into silicone grease. The heat dissipating agent 60 may be any known heat dissipating agent, and may be one using silicone-free grease, one that hardens after application, one that maintains viscosity without hardening after application, or the like.

As shown in FIG. 6, the heat dissipating agent 60 is filled in the gap between the first light source substrate 11, which is a heating element, and the wall portion 41. Specifically, the heat dissipating agent 60 is filled at least inside the groove 411 and between the flat portion 412 and the first light source substrate 11 . Thereby, the heat generated by the first light source substrate 11 is conducted to the wall portion 41 of the case 40 made of metal via the heat dissipating agent 60, and can be efficiently dissipated.

From here on, of the method for manufacturing the HUD device 100 having the above configuration, an example of the process of injecting the heat dissipating agent 60 will be mainly described.

Before injecting the heat dissipating agent 60, the display device 10 that has been assembled in advance into a unit is inserted through the opening 40a of the case 40 that has been turned over, and assembled inside the case 40, as shown in FIG. That is, an arrangement step is performed in which the first light source substrate 11 as a heating element is arranged at a position facing the wall portion 41 of the case 40 .

Following the placement step, as shown in FIG. 6, an injection step is performed in which the heat dissipating agent 60 is injected into the gap between the first light source substrate 11 and the wall portion 41 from the injection port 410 of the wall portion 41.

In the injection step, first, the nozzle 61 for discharging the heat dissipating agent 60 is set in the injection port 410. At this time, the attitude of the nozzle 61 during injection can be controlled by aligning the tip of the nozzle 61 with the mortar-shaped inner surface 410a formed in the injection port 410. After setting the nozzle 61, the heat dissipating agent 60 is discharged from the nozzle 61. The released heat dissipating agent 60 flows along the groove 411 of the wall portion 41 toward the through hole 42 a formed in the bottom portion 42 . At this time, the through holes 42a serve as air holes, allowing the heat dissipating agent 60 to flow well. In the process of filling the groove 411 with the heat dissipating agent 60, the heat dissipating agent 60 spreads in the surface direction of the first light source substrate 11 due to the pair of ribs 414 whose distance increases toward the first light source substrate 11. The light flows and accumulates between the flat portion 412 and the first light source substrate 11. Then, after filling at least the inside of the groove 411 and the space between the flat portion 412 and the first light source substrate 11 with the heat dissipating agent 60, the step of injecting the heat dissipating agent 60 is completed.

Note that the through hole 42a of the bottom portion 42 can be used to confirm whether the required amount of heat dissipating agent 60 is filled. For example, when the inside of the through hole 42a is filled with the heat dissipating agent 60, it can be determined that the required amount of the heat dissipating agent 60 is filled. That is, the through hole 42a functions not only as an air hole but also as a hole for checking whether or not the heat dissipating agent 60 is filled. Further, excess heat dissipating agent 60 leaking out from the through hole 42a or accumulating on the inner surface 410a of the injection port 410 may be wiped off after the injection step.

In addition to the injection step of injecting the heat dissipating agent 60 between the first light source substrate 11 and the wall portion 41, a heat dissipating agent (not shown) is also applied to the second light source substrate 12 and the third light source substrate 13. Then, the cover 50 is attached to the case 40 so as to close the opening 40a. The second light source substrate 12 and the third light source substrate 13 are in contact with the cover 50 via a heat dissipating agent. Thereby, the heat generated by the second light source substrate 12 and the third light source substrate 13 is conducted to the cover 50 on which the heat sink 51 is formed via the heat dissipating agent, and can be efficiently dissipated.

Here, in a configuration that does not include the injection port 410 (hereinafter referred to as a comparative configuration), a heat dissipating agent is applied to the first light source substrate 11 or the wall before the step of arranging the display 10 in the case 40. 41 must be applied. Therefore, in the comparative configuration, there are parts to which a heat dissipating agent should be applied before the display device 10 is assembled to the case 40, and parts to which the heat dissipating agent should be applied after the display device 10 is assembled to the case 40. There are restrictions on the assembly procedure. On the other hand, by using the injection port 410 according to the present disclosure, after the display device 10 is assembled to the case 40, the heat dissipating agent can be applied to the necessary portions all at once. That is, according to the HUD device 100 and the manufacturing method thereof according to the present disclosure, the assemblability is good.

Note that the present disclosure is not limited to the above embodiments and drawings. It is possible to make changes (including deletion of components) as appropriate without changing the gist of the present disclosure.

The display 10 is not limited to a projection type display using a DMD, but may be any other display. For example, the display device 10 may use an LCD (Liquid Crystal Display) or an OLED (Organic Light-Emitting Diode). Further, the vehicle display device is not limited to the HUD device 100 that displays the virtual image Vi, but may be one that displays an image on the display surface of the display device 10.

The configuration of the optical system within the HUD device 100 is arbitrary as long as it can radiate the display light DL from the display 10 to the windshield WS, and the number, shape, and arrangement of the mirrors forming the reflection section 20 may be changed as appropriate. be able to.

Although the example in which the heat generating body is the first light source substrate 11 has been described above, the type of the heat generating body is not limited and can be changed arbitrarily. For example, the heating element may be the second light source substrate 12 or the third light source substrate 13. Further, the heating element may be a board on which a motor for rotationally driving a concave mirror is mounted, a board on which a control unit is mounted, a core of a transformer included in a power supply device mounted on a vehicle display device, or the like.

The type of vehicle in which the vehicle display device is mounted is not limited. The vehicle display device is applicable to various vehicles such as four-wheeled motor vehicles and motorcycles.

In the above description, descriptions of known technical matters have been omitted as appropriate in order to facilitate understanding of the present disclosure.

100 Head-up display device (an example of a vehicle display device)
DL Display light WS Windshield Vr Passenger Vi Virtual image 10 Display 10a Frame 11 First light source substrate (an example of a heating element)
20 Reflection part 30 Housing part 40 Case 40a Opening part 41 Wall part 410 Inlet 410a Inner surface part 411 Groove 412 Flat part 413 Recessed part 414 Rib 42 Bottom part 50 Cover 60 Heat sink 61 Nozzle

Claims (3)

A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element and a bottom portion in which a through hole is formed ,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The wall portion has a groove recessed in a direction away from the heating element, and stands from the bottom toward the opening,
The groove connects the injection port and the through hole and extends from the injection port toward the bottom.
Vehicle display device. A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element and a bottom portion,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The wall portion has a groove recessed in a direction away from the heating element, and a flat portion adjacent to the groove, and stands from the bottom portion toward the opening,
The groove is connected to the injection port and extends from the injection port toward the bottom,
The heat dissipating agent is filled inside the groove recessed with respect to the flat part and between the flat part and the heating element.
Vehicle display device. A heating element; a case accommodating the heating element and having an opening formed therein;
The case has a wall portion facing the heating element,
An injection port for injecting a heat dissipating agent into a gap between the heating element and the wall is provided at an end of the wall facing the opening,
The injection port has an inner surface recessed in a direction away from the heating element,
The inner surface portion is formed in a mortar shape.
Vehicle display device.