JP2003104086A - Displaying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a displaying device having a heat radiating structure capable of efficiently radiating heat generated from a light source. SOLUTION: This displaying device comprises a liquid crystal display element 33, a light emitting diode 35 of a discrete type for lighting up the liquid crystal display element 33, a hard patchboard 37 for connecting and fixing the light emitting diode 35, a heat sink 38 disposed on the connection and fixing surface side of the light emitting diode 35 of the hard patchboard 37, and a silicone rubber 39 having elasticity disposed between the hard patchboard 37 and the heat sink 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a display device having a light source for illuminating a transmissive display member (for example, a transmissive liquid crystal display element) from behind.

[0002]

2. Description of the Related Art Conventionally, a display device as shown in FIG. 5 has been known, and a liquid crystal display element A having a polarizing member attached to the front and rear surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates. ,
A light source C that is connected to the hard wiring board B and illuminates the liquid crystal display element A is provided, and a display image emitted from the liquid crystal display element A illuminated by the light source C is reflected by a reflecting mirror D, and a vehicle windshield or a semi-transparent plate ( There is a device such as a reflection plate) for projecting on the display unit E. Such a display device is called a head-up display.

Since such a display device has a structure for projecting on the display section E, a part of light is transmitted at the time of projection, and it is necessary to project a display image with good contrast even in the daytime. Therefore, it is necessary to illuminate the liquid crystal display element A with a light source having high brightness such as a halogen lamp or a light emitting diode.

[0004]

However, such a display device may be used in a high temperature environment by being exposed to direct sunlight like a vehicle, and the light source C is substantially sealed. In order to illuminate while generating heat,
There is a possibility that the allowable temperature limit of the light source C and other electronic parts may be exceeded, which is a problem.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a display device having a heat dissipation structure capable of efficiently dissipating heat generated from a light source.

[0006]

According to a first aspect of the present invention, there is provided a display device comprising a transmissive display member, a discrete type light emitting diode for illuminating the transmissive display member, and the light emitting diode. A wiring board for connection and fixation, a heat dissipation member provided on the connection fixation surface side of the light emitting diode in the wiring board, and an elastic heat transfer member provided between the wiring board and the heat dissipation member,
It is characterized by comprising.

Further, the display device of the present invention, as set forth in claim 2, projects a display image of a transmissive display member mounted on a vehicle and illuminated by a light source onto a windshield surface or a reflector of the vehicle. And a display device for displaying,
The light source is composed of a discrete type light emitting diode, the light emitting diode is soldered to a wiring board and fixedly disposed, and a heat dissipation member is provided on a solder connection surface side of the wiring board, and a solder connection surface of the wiring board is provided. A heat transfer member having elasticity is provided so as to be in contact with the heat dissipation member.

According to a third aspect of the present invention, in the display device according to the first or second aspect, the heat transfer member is electrically insulating and is in contact with the leads of the light emitting diode. It is characterized by being arranged.

Further, as described in claim 4, in the display device according to any one of claims 1 to 3,
The heat transfer member is provided so as to be sandwiched while being pressed by the wiring board and the heat dissipation member.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described with reference to the accompanying drawings, taking as an example a vehicle head-up display for displaying vehicle speed, engine speed, etc.

FIG. 1 shows a vehicle head-up display mounted on a vehicle, and a display image projected by a display device 3 provided on an upper portion of a dashboard 2 of the vehicle 1 is
The surface of the windshield 4 reflects in the direction of the observer 5. The observer 5 can observe the displayed image as a virtual image V by superimposing it on the landscape.

Further, the display device 3 according to the embodiment of the present invention is provided with a concave mirror 31 and a liquid crystal display 32 in a housing 30 provided so as to be embedded in the upper portion of the dashboard 2, and FIG. Explain.

The housing 30 is made of a light-shielding synthetic resin material, and has a first opening 30A for opening an upper portion (on the windshield side) where the concave mirror 31 is disposed and a second opening for projecting a heat sink which will be described later. 30B is provided, and sunlight is stored in the housing 30 in the liquid crystal display 32.
A light-shielding wall 30C that prevents the virtual image V from becoming hard to be seen (washout) by being incident on is provided, and is formed integrally with the housing 30 in the present embodiment. Further, a translucent cover 30D made of a translucent synthetic resin material (for example, acrylic) is provided on the upper portion of the housing 30, and is disposed so as to close the first opening 30A.

The concave mirror 31 reflects the display light projected from the liquid crystal display 32 to the windshield 4 side, and is provided so that the angle can be adjusted so that the observer 5 can easily visually recognize the display image.

The liquid crystal display 32 projects the display image of the transmissive display element onto the windshield via the concave mirror 32, and as shown in FIG. 2, the liquid crystal display element (transmissive display member) 33. , Reflecting member 34, light emitting diode 3
5, a lens array (lens) 36, a hard wiring board (wiring board) 37, a heat sink (heat dissipation member) 38, and a silicone rubber (heat transfer member) 39.

The liquid crystal display element 33 is a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates and polarizing members are attached to the front and rear surfaces thereof. In addition, the liquid crystal display element 33 drives a liquid crystal based on an arithmetic circuit (not shown) that measures the vehicle speed and the engine speed based on the output signals from the vehicle speed sensor and the engine speed sensor provided in the vehicle 1. A liquid crystal drive circuit (not shown) for displaying the measured values of the speed of the vehicle 1 and the engine speed as numerical values.

The reflecting member 34 is formed of a white synthetic resin material in a cylindrical shape with both ends open, and one opening (opening on the concave mirror side) 34A is arranged so as to be closed by the liquid crystal display element 33. To be done.

The light emitting diode 35 is provided on the other opening 34B side of the reflecting member 34. In this case, a plurality of discrete type and narrow directivity (20 to 30 degrees in this embodiment) are provided. It is used and is fixedly arranged on the hard wiring board 37 in such a direction that the illumination light passes through the inside of the reflecting member cylinder and illuminates the liquid crystal display element 33. It is desirable that the light emitting diodes 35 are arranged at equal intervals on the hard wiring board 37 so as to prevent uneven illumination.
In this case, as shown in FIG. 3, they are densely arranged at equal intervals.

The lens array 36 is made of a translucent synthetic resin material (for example, acrylic) and has a spherical convex portion 36 facing the respective positions where the plurality of light emitting diodes 35 are arranged.
It has A, and is provided between the reflecting member 34 and the light emitting diode 35. With this convex portion 36A,
The liquid crystal display element 33 can be illuminated by refracting the illumination light from the light emitting diode 35 as illumination light having a narrower directivity.

The convex portion 36A of the lens array 36
Is desired to have a shape such that the illumination light is emitted in a direction substantially perpendicular to the lens array 36.
5 is formed in a shape having a curvature and a size corresponding to the degree of directivity of 5 and the disposition distance from the light emitting diode 35 to the lens array 36.

As shown in FIGS. 3 and 4, the hard wiring board 37 has insulating properties provided with through holes 37A and 37B, copper foil wiring provided on the back surface, and lands (not shown) continuous to the copper foil wiring. The glass cloth base material is made of epoxy resin. Further, the hard wiring board 37 is provided with the light emitting diode 35 disposed on the front surface side
Lead 35A penetrates through hole 37A and leads 3
The land projecting from the back surface side of the hard wiring board 37 of 5A and the land are connected and fixed by the solder 37C.

The heat sink 38 is made of an aluminum material,
As shown in FIGS. 3 and 4, the fixed portion 38A, the storage portion 38
B, a radiation fin 38C is provided. Fixed part 38A
Is formed of a screw hole corresponding to the position of the through hole 37B of the hard wiring board 37, and a fixing member (not shown) made of a screw or a bolt is screwed into the screw hole so that a heat sink is provided on the back surface side of the hard wiring board 37. 38 for fixedly arranging. The storage portion 38B is formed in a concave shape slightly shallower than the thickness of the silicone rubber 39, and is for storing the silicone rubber 39. In addition, the radiation fin 38C is
A large number are provided (shown in FIG. 2) so as to project from the second opening portion 30B of the housing 30 and can contact the air outside the housing 30. Therefore, the heat radiation fins 38C of the heat sink 38 can efficiently dissipate the heat into the air, and the heat sink 38 and the silicone rubber 39 and the hard wiring board 37 that are in contact with the heat sink 38 can be cooled.

The silicone rubber 39 is a plate-like electrical insulating member having heat transferability and elasticity, and is contained in the storage portion 38B.
By being sandwiched while being pressed by the hard wiring board 37 and the heat sink 38, it is elastically deformed along the unevenness due to the leads 35A and the solder 37C on the back surface of the hard wiring board 37, and the back surface of the hard wiring board 37 and the leads 35.
A, the solder 37C, and the housing portion 38B of the heat sink 38
It is arranged so as to contact with and. Therefore, the heat of the hard wiring board 37 heated by the light emitting diode 35, the leads 35A, and the solder 37C can be dissipated to the heat sink 38 in a wide contact area.

The display device comprises a liquid crystal display element 33,
A discrete type light emitting diode 35 for illuminating the liquid crystal display element 33, a hard wiring board 37 for connecting and fixing the light emitting diode 35, a heat sink 38 provided on the connection fixing surface side of the light emitting diode 35 in the hard wiring board 37, and a hard By including the elastic silicone rubber 39 provided between the wiring board 37 and the heat sink 38, elastic deformation of the silicone rubber 39 causes the rigid wiring board 37 to be irrespective of unevenness on the back side of the rigid wiring board 37. Silicone rubber 39, which serves as a heat transfer member, can come into contact with the rear surface of the above in a large area. Therefore, the heat of the hard wiring board 37 heated by the light emitting diode 35 can be efficiently dissipated to the silicone rubber 39, and the heat dissipation efficiency of the light emitting diode 35 can be suppressed from rising beyond the allowable heat resistance range. Display device.

Further, in the present embodiment, since the silicone rubber 39 is also in contact with the leads 35A and the solder 37C, the heat is dissipated from the light emitting diode 35 which is a heat source and a portion closer to the light emitting diode 35 (a portion which easily becomes hot). As a result, the display device has excellent heat dissipation efficiency.

Further, since the silicone rubber 39 is provided so as to be sandwiched while being pressed by the hard wiring board 37 and the heat sink 38, it has a structure having high adhesion and a display device having a wide contact area and excellent heat dissipation efficiency. .

In the embodiment of the present invention, the case where the silicone rubber 39 is used as the heat transfer member has been described as an example, but the present invention is not limited to this.
For example, an elastic material containing rubber such as raw rubber, natural rubber, urethane-based or styrene-based synthetic rubber, and a thermally conductive filler such as powdered alumina, beryllia or magnesia may be used.

Further, although the transmissive display member in the embodiment of the present invention uses a liquid crystal display element, it may be, for example, an electrochromic device or a translucent substrate except a predetermined portion. It is also possible to perform light-shielding printing by means of light-shielding printing so that a display image having a shape corresponding to the predetermined portion is transparently displayed by illumination from the back side.

[0029]

The present invention is a display device for displaying a display image of a transmissive display member illuminated by a discrete type light emitting diode, and has a heat dissipation structure capable of efficiently dissipating heat generated from a light source. A display device can be provided.

[Brief description of drawings]

FIG. 1 is a side view of a vehicle showing an embodiment of the present invention.

FIG. 2 is a sectional view of the display device showing the embodiment.

FIG. 3 is a perspective view of a main part showing the embodiment.

FIG. 4 is a side view of an essential part showing a part of the embodiment in a cross section.

FIG. 5 is a side view of a display device showing a conventional example.

[Explanation of symbols]

1 vehicle 3 display devices 33 Liquid crystal display element (transmissive display member) 35 light emitting diode 35A lead 37 Hard wiring board (wiring board) 37C solder 38 Heat sink (heat dissipation member) 39 Silicone rubber (heat transfer member)

Claims (4)

[Claims] 1. A transmissive display member, a discrete type light emitting diode for illuminating the transmissive display member, a wiring board for connecting and fixing the light emitting diode, and a connection fixing surface side of the light emitting diode on the wiring board. A display device, comprising: a heat dissipation member provided; and an elastic heat transfer member provided between the wiring board and the heat dissipation member. 2. A display device which is mounted on a vehicle and projects and displays a display image of a transmissive display member illuminated by a light source on a windshield surface or a reflector of the vehicle, wherein the light source is a discrete type. It is composed of a light emitting diode, and this light emitting diode is soldered to a wiring board and fixedly arranged. A heat dissipation member is provided on the solder connection surface side of the wiring board, and is in contact with the solder connection surface of the wiring board and the heat dissipation member. A display device comprising a heat transfer member having elasticity as described above. 3. The display device according to claim 1, wherein the heat transfer member is electrically insulating and is arranged so as to come into contact with the leads of the light emitting diode. 4. The display device according to claim 1, wherein the heat transfer member is provided so as to be sandwiched while being pressed by the wiring board and the heat dissipation member.