JP2009288484A - Light emitting display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting display that prevents electromagnetic noise generated from a circuit board from leaking and excellently dissipates heat. <P>SOLUTION: The circuit board 44 is covered with a housing 46 made of a metallic material, a lid body 47 made of a metallic material, a light box 49 made of a metallic material, etc., to block the electromagnetic noise generated from the circuit board 44. Heat generated by a back light source 42 as a heat source is absorbed by the housing 46 and lid body 47 made of the metallic materials, and the absorbed heat is dissipated from the housing 46 and the lid body 47 directly to the outer side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting display device in which a liquid crystal display panel and a liquid crystal display having a backlight light source such as a light emitting diode for illuminating the liquid crystal display panel are accommodated in a housing.

Conventionally, various head-up display devices for vehicles using a liquid crystal display have been proposed. Such a vehicle head-up display device 1 projects display light L onto a transflective plate called a vehicle windshield or combiner to display a virtual image. The vehicle head-up display device 1 includes a case 3 having a translucent window portion 2 and a liquid crystal display 4 and a reflecting mirror 5 accommodated therein. The display light L emitted from the liquid crystal display 4 is reflected. It is reflected by the mirror 5 and projected onto the windshield or transflective plate (see FIG. 4).
JP 2004-17708 A

  The liquid crystal display 4 includes a liquid crystal display panel 6, a backlight light source 7 such as a light emitting diode that transmits and illuminates the liquid crystal display panel 6 from behind, and a heat sink 8 fixed to the backlight light source 7. It is. The liquid crystal display panel 6 includes a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates on which a transparent electrode film is formed, and polarizing plates attached to both front and rear surfaces of the liquid crystal cell. A drive circuit 10 for driving the liquid crystal display panel 6 and a drive circuit 10 a for driving the backlight light source 7 are mounted on the circuit board 11.

  However, electromagnetic noise generated from the drive circuit 10 and the circuit board 11 may cause noise in the radio mounted on the vehicle. The heat sink 8 can absorb the heat generated by the backlight light source 7. However, since the liquid crystal display 4 is accommodated in the case 3, the heat absorbed by the heat sink 8 can be efficiently transferred to the outside of the case 3. There was a problem that heat could not be dissipated.

  The present invention has been made in view of these problems, and it is an object of the present invention to provide a light-emitting display device that makes it difficult to leak electromagnetic noise generated from a circuit board and can perform heat dissipation well. is there.

  In order to solve the above-described problems, the present invention provides a liquid crystal display panel, a first circuit board electrically connected to the liquid crystal display panel, and the liquid crystal disposed behind the liquid crystal display panel. A backlight light source that transmits and illuminates the display panel; a metal second circuit board that mounts the backlight light source; an opening that is provided so as to expose at least a display area of the liquid crystal display panel; A first mounting portion having a concave shape for mounting and fixing the circuit board, and a second mounting portion for receiving and fixing the second circuit board, and at least the second circuit board is A housing made of a metal material that absorbs heat, a lid made of a metal material fixed to the housing and magnetically shielded to cover the first circuit board, and the liquid crystal display panel disposed in the opening. A base plate made of a metal material on which a light source is mounted and electrically connected to the housing; and a liquid crystal display for displaying light from the backlight light source electrically connected to the base plate and the second circuit board And a light box made of a substantially cylindrical metal material guided to a panel. With this configuration, electromagnetic noise generated from the circuit board can be shielded by a housing made of a metal material, a lid made of a metal material, a light box made of a metal material, etc. The heat generated from the backlight light source, which is a heat source, is transmitted to the second circuit board 45 made of metal, and then absorbed by the metal housing or lid, and the absorbed heat Can be radiated directly from the housing and lid to the outside, and a light-emitting display device with good electromagnetic shielding and heat dissipation can be provided.

  According to a second aspect of the present invention, in the light-emitting display device according to the first aspect of the present invention, the housing includes a blower member disposed on an outer surface portion of the housing corresponding to the second placement portion. The light emitting display device. By comprising in this way, the heat accumulate | stored in the housing can be spread | diffused by a ventilation member, and heat dissipation can be improved.

  According to a third aspect of the present invention, in the light emitting display device according to the first aspect of the present invention, the housing is integrally provided with a radiation fin at an outer surface portion of the housing corresponding to the second mounting portion. The light emitting display device. By comprising in this way, heat dissipation can be improved further.

  According to a fourth aspect of the present invention, in the light emitting display device according to the third aspect of the present invention, a blower member is disposed on an outer surface portion of the radiating fin. By comprising in this way, heat dissipation can be improved with a radiation fin.

  In the present invention, electromagnetic noise generated from a circuit board can be shielded by covering the circuit board with a housing made of a metal material, a lid made of a metal material, a light box made of a metal material, etc., and a heat source The heat generated from the backlight light source is absorbed by the housing and lid made of a metal material, and the absorbed heat can be directly radiated from the housing and lid directly to the outside. The initial purpose can be achieved.

  Hereinafter, based on an accompanying drawing, it explains based on an embodiment which applied a light emitting display device made into a subject of the present invention to a head up display device for vehicles.

  FIG. 1 and FIG. 2 show a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a head-up display device, and FIG. 2 is a cross-sectional view showing a main part of the embodiment.

  In the figure, the vehicle head-up display device 20 is disposed in a dashboard 21 of the vehicle. The display light L projected by the vehicle head-up display device 20 is reflected by the windshield 22 to the observer 23. The observer 23 can visually recognize the virtual image V superimposed on the landscape.

  The vehicle head-up display device 20 is configured by housing a reflector 30, a liquid crystal display 40 which is a light emitting display device, and the like in a case body 50.

  The reflector 30 includes a concave mirror 31, a mirror holder 32, and a stepping motor 33, and is fixedly held on the case body 50. The concave mirror 31 is formed by depositing a metal (for example, aluminum) on a resin (for example, polycarbonate) to form a reflective surface 31a. The reflecting surface 31a is a concave surface, and the display light L is enlarged to display the virtual image V. The concave mirror 31 is bonded to the mirror holder 32 with a double-sided adhesive tape. The mirror holder 32 is made of resin (for example, ABS), and the gear portion 32a and the shaft portion 32b are integrally formed.

  A gear 33 a is attached to the rotation shaft of the stepping motor 33, and the gear 33 a is engaged with the gear portion 32 a of the mirror holder 32. The concave mirror 31 is supported so as to be rotatable together with the mirror holder 32, and the projection direction of the display light L can be adjusted by rotating the concave mirror 31 by the stepping motor 33. The observer 23 operates a push button switch (not shown) to adjust the angle of the concave mirror 31 so that the display light L is reflected at the position of the eyes (that is, the virtual image V can be visually recognized).

  A liquid crystal display 40 which is a light emitting display device drives a liquid crystal display panel (liquid crystal display element) 41, a backlight light source 42 using high-brightness LEDs that transmit and illuminate the liquid crystal display panel 41 from behind, and the liquid crystal display panel 41. A first circuit board 44 on which a drive circuit 43 including electronic parts and a drive circuit 43a including electronic parts for driving the backlight light source 42 are mounted, and a metal second circuit board 45 on which the backlight light source 42 is mounted. The liquid crystal display panel 41 is assembled and a housing 46 made of a metal material for mounting and fixing the first circuit board 44 and the second circuit board 45, and the first circuit board 44 fixed to the housing 46 A lid 47 made of a metal material that covers and magnetically shields, and a metal material on which the liquid crystal display panel 41 is placed and is electrically connected to the housing 46 And a light box 49 made of a substantially cylindrical metal material that is electrically connected to the base plate 48 and the second circuit board 45 and guides the light from the backlight light source 42 to the liquid crystal display panel 41. And the whole is constituted.

  The case body 50 of the vehicle head-up display device 20 is made of resin (for example, polypropylene), and the liquid crystal display 40 and the reflector 30 are housed in the case body 50, and the display light L is received in the case body 50. An exit window 51 is provided. The window 51 is made of a translucent resin such as acrylic and has a curved shape. The case body 50 is provided with a light shielding wall 52 to prevent a phenomenon (washout) in which external light such as sunlight enters the liquid crystal display 40 and the virtual image V becomes difficult to see. The light shielding wall 52 has a flat plate shape and is formed so as to hang obliquely from the upper part of the case body 50. The case body 50 is formed with an opening 53 for assembly through which the housing 46 of the liquid crystal display 40 is inserted.

  By the way, the liquid crystal display panel 41 constituting a part of the light emitting display device in the first embodiment includes a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates on which a transparent electrode film is formed, and both front and rear surfaces of the liquid crystal cell. The liquid crystal display panel 41 is assembled and fixed to the housing 46 via a base plate 48 made of a metal material.

  Further, the housing 46 is made of a metal material such as aluminum, and the housing 46 has a part of the housing 46 to the outside from the opening 53 for assembling the case body 50 of the vehicle head-up display device 20. It is provided to be exposed.

  The housing 46 is provided with a transparent displayable opening 46a that is cut out so that at least the display area of the liquid crystal display panel 41 is exposed at a position where the liquid crystal display panel 41 is attached. The liquid crystal display panel 41 is assembled and fixed to the window frame portion together with the base plate 48 made of a metal material. At this time, a window portion 48a is formed in the center of the base plate 48 in accordance with the transmissive display area of the liquid crystal display panel 41, and a light box 49 made of a metal material is formed along the rectangular shape of the window portion 48a. Are arranged so as to connect between the base plate 48 and the second circuit board 45, and from the base plate 48 made of a metal material to the second circuit board 45 through a light box 49 made of the metal material. By connecting as a ground line, the electromagnetic shielding property can be improved.

  In addition, a first placement portion 46b made of a concave-shaped recess for mounting and fixing the first circuit board 44 is formed on one side of the wall portion of the housing 46 (lower wall portion in FIG. 2). In order to magnetically shield the first circuit board 44, the first mounting portion 46b is covered with a lid 47 made of a metal material having electromagnetic shielding properties such as a galvanized steel plate.

  Further, the housing 46 is provided with a second mounting portion 46c on the inner wall surface on the side opposite to the side on which the liquid crystal display panel 41 is mounted and fixed, to which the second circuit board 45 can be assembled and fixed. A plurality of heat radiating fins 46d are integrally provided on the outer surface of the housing 46 corresponding to the second mounting portion 46c.

  Further, in order to electrically connect the first circuit board 44 and the liquid crystal display panel 41, a flexible print is provided between the liquid crystal display panel connection connector 44 a provided on the first circuit board 44 and the liquid crystal display panel 41. It is provided so as to be electrically connected via a wiring member 70 such as a wiring board. In addition, in order to electrically connect the first circuit board 44 and the metal second circuit board 45 on which the backlight light source 42 is mounted, a backlight light source connection provided on the first circuit board 44 is used. Flexible printed wiring between the connector 44b and a wiring pattern (not shown) provided on the second circuit board 45 made of a metal material (for example, aluminum or its alloy, zinc or its alloy) via an insulating film The first circuit board 44 and the backlight light source 42 mounted on the second circuit board 45 are electrically connected by being electrically connected via a wiring member 70a such as a plate.

  According to this embodiment, since the first circuit board 44 is covered with the housing 46 and the lid body 47, electromagnetic noise generated from the first circuit board 44 including the drive circuits 43 and 43a can be shielded. Electromagnetic noise generated from the backlight light source 42 side can be shielded by the light box 49, the base plate 48, the second circuit board 45, etc. made of a metal material, and the shielding effect can be maintained.

  Further, the heat generated from the backlight light source 42 as a heat source can be directly transmitted to the second circuit board 45 made of a metal material for mounting the backlight light source 42, and the second circuit board 45 is housed in the housing. Since the second mounting portion 46c provided in 46 is directly assembled and fixed, the heat transmitted to the second circuit board 45 can be guided to the housing 46 side. Heat can be transferred by the housing 46, the lid 47, and the heat radiation fins 46d provided on the housing 46, and the heat is directly transferred to the outside by the heat radiation fins 46d provided on the housing 46, the lid 47, and the housing 46. And the drive circuits 43, 43a including the electronic components mounted on the first circuit board 44 and the like. The problem that the liquid crystal display panel 41 cannot be operated normally due to the heating of the liquid crystal display panel 41 can be solved as well as the problem that the liquid crystal display panel 41 exceeds the allowable temperature limit. Can be suppressed.

  FIG. 3 shows a second embodiment of the present invention. Here, the heat dissipating fins 46d are integrally provided on the outer surface of the housing 46 exposed to the outside, and the air blowing member 80 is provided on the outer surface of the heat dissipating fins 46d. Thus, the heat radiation performance can be further enhanced in combination with the heat radiation fins 46d.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention. For example, the heat storage effect is enhanced by increasing the wall thickness of the housing 46, and the heat radiation effect is enhanced by setting the intervals between the radiation fins 46d close or changing the shape of the radiation fins 46d to increase the surface area. The air blowing member 80 may be set directly on the outer surface side of the 46 so that the heat transmitted through the housing 46 is cooled while stirring.

FIG. 1 is a schematic configuration diagram showing an example in which the light-emitting display device according to the first embodiment of the present invention is applied to a head-up display device. FIG. 2 is a cross-sectional view showing a main part of the light emitting display device according to the embodiment. FIG. 3 is a cross-sectional view showing a main part of a light emitting display device according to a second embodiment of the present invention. FIG. 4 is a cross-sectional view showing a conventional example of a light emitting display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Head-up display apparatus for vehicles 21 Dashboard 22 Windshield 23 Observer 30 Reflector 31 Concave mirror 31a Reflective surface 32 Mirror holder 32a Gear part 32b Shaft part 33 Stepping motor 33a Gear 40 Liquid crystal display (light emitting display apparatus)
41 Liquid Crystal Display Panel 42 Backlight Light Source 43, 43a Drive Circuit 44 First Circuit Board 44a, 44b Connector 45 Second Circuit Board 46 Housing 46a Opening 46b First Placement 46c Second Placement 46d Heat Dissipation Fin 47 Lid 48 Base plate 48a Window 49 Light box 50 Case body 51 Window 52 Light shielding wall 53 Opening 70, 70a Wiring member 80 Blowing member L Display light V Virtual image

Claims (4)

  A liquid crystal display panel; a first circuit board electrically connected to the liquid crystal display panel; a backlight light source disposed behind the liquid crystal display panel and illuminating the liquid crystal display panel; and the backlight light source A metal second circuit board to be mounted, an opening provided so as to expose at least a display area of the liquid crystal display panel, and a concave first mounting portion for mounting and fixing the first circuit board A housing made of a metal material that absorbs at least heat generated from the second circuit board, and a second mounting portion that houses and fixes the second circuit board. A lid made of a metal material that is fixed and covers and shields the first circuit board, and a metal that is disposed in the opening and on which the liquid crystal display panel is placed and is electrically connected to the housing A base plate made of a material, and a light box made of a substantially cylindrical metal material that is electrically connected to the base plate and the second circuit board and guides light from the backlight light source to the liquid crystal display panel And a light-emitting display device.   The light emitting display device according to claim 1, wherein a blower member is disposed on the outer surface of the housing corresponding to the second placement portion.   The light emitting display device according to claim 1, wherein the housing is integrally provided with a heat radiation fin at an outer surface portion of the housing corresponding to the second placement portion.   The light emitting display device according to claim 3, wherein an air blowing member is disposed on an outer surface portion of the heat radiation fin.

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