JP2016179715A - Display device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device for a vehicle having a structure of which a size and a weight can be reduced.SOLUTION: A display control IC 49 mounted on a control wiring board 29 is adhered to a protruded part 45 of a metal wiring board 31. Heat from the display control IC 49 is transmitted to the metal wiring board 31 and is diffused. Meanwhile, relatively cold air 66 enters inside a case body 32 from a lower vent hole 62. The entering air 66 contacts with the metal wiring board 31, and rises while taking the heat of the metal wiring board 31 away. The heated air 67 rises based on the principle of natural convection, and flows out from an upper vent hole 61 as an upper opening. That is, the metal wiring board 31 is cooled efficiently by circulation of the air 66, 67, and a temperature increase of the heat generating component 49 or the like is prevented.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a display device for a vehicle having a heat dissipation structure.

A conventional vehicle display device is disclosed in Patent Document 1, for example.
As shown in FIG. 1 of Patent Document 1, in an electronic control device that prevents connection failure of an electronic component having a heat generating element and increases heat dissipation efficiency, a heat generating element (31) (the numbers in parentheses are described in Patent Document 1). The electronic component (30) having a heat sink (32) that promotes heat dissipation of the heat generating element (31) is connected to the metal casing (20) on the heat dissipation side (30b). It arrange | positions so that it may contact | abut to the upper surface (40a) of a board | substrate (40) in a heat-dissipating side (30c) while contact | abutting to the bottom wall (21a) of an upper cover (21).

  Further, by fastening bolts (24) that pass through the through holes (41) of the substrate (40) to the spacers (23), the bottom wall (21a) of the housing (20) is attached to the electronic component (30). While being pressed by the heat radiating side (30b), the upper surface (40a) of the board (40) is pressed by the non-heat radiating side (30c) of the electronic component (30). The electronic component (30) and the substrate (40) are electrically connected via a flexible substrate (50) having flexibility.

  In recent vehicle display devices, graphic circuits have been improved in performance due to the increase in content to be displayed and the need to output more easily understandable image representations, and multilayer circuit boards have been adopted along with circuit complexity. The Multilayered substrates increase costs.

  In addition, the graphic processor, which is at the center of high-performance graphic circuits, increases the system clock frequency to improve graphic performance, expands the bus width of the internal wiring of the graphic processor and performs wiring for parallel processing of image processing data. Heat generation increases due to parallelization, multi-layered internal bus wiring for package size reduction, and an increase in current consumption accompanying an increase in processing speed.

  In order to cope with this increasing heat generation, it is necessary to increase the heat transfer amount by expanding the area of the heat sink (32) in the structure of Patent Document 1. However, the increase in size of the heat sink (32) increases the cost of the display device and increases the size and weight of the display device.

In recent years, two contradictory demands have been made: higher performance and smaller and lighter display devices.
Therefore, there is a demand for a display device for a vehicle having a structure that can improve the performance and reduce the size and weight of the display device.

JP 2009-295706 A

  An object of the present invention is to provide a display device for a vehicle having a structure capable of reducing the size and weight of the display device while improving the performance.

The invention according to claim 1 is a liquid crystal display module for displaying vehicle information;
A metal wiring board that can be deformed by mounting optical components for analog gauges or indicators for displaying vehicle information,
A control wiring board installed between the liquid crystal display module and the metal wiring board and mounted with a circuit for controlling the liquid crystal display module;
A control circuit device mounted on the control wiring board and controlling the liquid crystal display module, or a control circuit peripheral device, is in close contact with the metal wiring board.

  In the invention according to claim 2, the metal wiring board includes a metal base and a copper foil layer that is covered with an insulating layer on at least one surface of the metal base to form a wiring pattern. It is characterized by being configured as a substrate.

  The invention according to claim 3 is characterized in that the metal wiring board is deformed along the unevenness of the component group mounted on the control wiring board, and is arranged close to the control wiring board.

In the invention according to claim 4, a liquid crystal display module for displaying vehicle information;
A metal wiring board that can be deformed by mounting optical components for analog gauges or indicators for displaying vehicle information,
A control wiring board installed between the liquid crystal display module and the metal wiring board and mounted with a circuit for controlling the liquid crystal display module;
The control circuit device mounted on the control wiring board and controlling the liquid crystal display module, or the control circuit peripheral device, hits the metal wiring board via a heat transfer material.

  In the invention according to claim 1, the control circuit device or the control circuit peripheral device mounted on the control wiring board and controlling the liquid crystal display module and the metal wiring board are brought into close contact with each other. The generated heat can be diffused via the metal wiring board. By this thermal diffusion action, the temperature rise of the control circuit device or the control circuit peripheral device is suppressed, and a more stable operation of the control circuit device or the like can be ensured.

  That is, the invention according to claim 1 does not require a conventional heat sink. Since a space for housing the heat sink is not necessary, the display device can be reduced in size, and the heat sink is unnecessary, so that the display device can be reduced in weight.

In the invention according to claim 2, since the metal wiring board is based on the metal base, not only the copper foil layer forming the wiring pattern but also the metal base itself functions as a heat sink.
Further, the metal base can be plastically processed, and can form and hold a desired shape. That is, since the shape addition is relatively simple, a plurality of wiring boards can be integrated into one sheet while corresponding to the configuration required for design and design. If one sheet is used, assembly is easier than a plurality of sheets.
That is, the assemblability is good, the number of component parts can be reduced, and the management of the parts becomes easy.

  In the invention according to claim 3, when the metal base is copper or aluminum, shape processing is easy, and it can be shaped along the uneven portion formed by the components mounted on the control wiring board, The total thickness of the metal wiring board and the control wiring board can be reduced. Further, even a vehicular display device having a curved design (design) can be shaped according to the shape, and can be adapted to a design having a smaller thickness.

  In the invention according to claim 4, by applying a control circuit device or a control circuit peripheral device mounted on the control wiring board to control the liquid crystal display module, and a metal wiring board through a heat transfer material, Similarly, the heat generated by the control circuit device or the control circuit peripheral device can be diffused via the metal wiring board. By this thermal diffusion action, the temperature rise of the control circuit device or the control circuit peripheral device is suppressed, and a more stable operation of the control circuit device or the like can be ensured.

  Since it is possible to change the thickness of the heat transfer material, it is possible to give a degree of freedom to the shape design of the metal wiring board. Further, even if there is an inevitable variation in manufacturing in the metal wiring board, it is possible to absorb this variation with the heat transfer material, and the manufacturing cost of the metal wiring board can be reduced.

It is a front view of the display apparatus for vehicles concerning the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is an exploded view of the display apparatus for vehicles. FIG. 4 is an enlarged view of part 4 of FIG. 3. It is a system block block diagram. FIG. 6 is a sectional view taken along line 6-6 of FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

  As shown in FIG. 1, the vehicle display device 10 includes, for example, a liquid crystal display module 11 formed of a TFT (thin film transistor) module in the center, analog gauges 12 and 13 on the left and right of the liquid crystal display module 11, and an upper side 14. This is a vehicle-mounted combination meter provided with warning designs 17, 18 and 19 on the left and right sides 15 and 16, respectively.

In this example, the left analog gauge 12 is a rotation meter having a dial 21 indicating an engine speed and a pointer 22, and the right analog gauge 13 is a speed having a dial 23 indicating a vehicle speed and a pointer 24. It is a meter.
That is, the combination meter is disposed in front of the driver's seat of the vehicle at a position that can be visually recognized by the driver, and displays various information such as vehicle information such as travel distance and outside air temperature so that the driver can visually recognize the information. It is.

The configuration of the vehicle display device 10 will be described with reference to FIGS. For ease of understanding, FIG. 3 will be described first.
As shown in FIG. 3, the vehicular display device 10 includes a lens 26, a turnout 27, a liquid crystal display module 11, an inner case 28, a control wiring board 29, a metal wiring board 31, and a case body 32. And a cover 33.

  The lens 26 is a translucent body provided with a warning design, a gauge display region, or a design such as a black frame for dividing the TFT display region, and is formed of a thin plate such as an acrylic resin or polycarbonate. The warning design (FIG. 1, reference numerals 17 to 19) may be formed by printing on the upper surface or the lower surface of the lens 26, or a preprinted film may be inserted during injection molding. It may be integrated.

  A colored layer having translucency or semi-translucency is provided on a portion other than the display range such as the design, gauge, and TFT, and the design is formed by a colored layer having translucency. When illuminated by the light sources 34 and 35 provided on the metal wiring board 31, a contrast is displayed due to a difference in transmitted luminance. That is, the light sources 34 and 35 are optical components for indicators, and LEDs (light emitting diodes) are preferable.

  The facing 27 is a member surrounding the outer periphery and the rear surface of the lens 26. The facing 27 is made of a light-shielding colored synthetic resin, such as black ABS resin, and holds the lens 26 with an adhesive or the like. The light from the light sources 34 and 35 provided on the metal wiring board 31 is divided by a partition wall integrally formed on the turn-back 27 so as to emit light only in a desired range.

  The liquid crystal display module 11 made of a TFT module omits a fine internal structure, but includes a liquid crystal panel, a backlight, a frame that houses and supports the liquid crystal panel and the backlight, and a metal plate 37 that covers the back of the frame. The inner case 28, the control wiring board 29, the metal wiring board 31, and the case body 32 are fastened together by a plurality of screws through attachment portions provided on the metal plate 37.

  Then, one end of the flexible circuit board is connected to the liquid crystal display module 11 made of a TFT module, and the other end of the flexible circuit board is connected to the control wiring board 29, whereby the liquid crystal display module 11 and the control wiring are connected. The substrate 29 is electrically connected.

  The inner case 28 is made of, for example, a white synthetic resin having a light shielding property, and a partition wall is formed between the turn-around 27 and the metal wiring board 31 so as to surround the warning light sources 34 and 35 and the gauge light source. , Each lighting range is divided. Further, a housing portion 38 for housing the liquid crystal display module 11 is provided on the front side.

  The control wiring board 29 is a hard wiring board made of glass fiber reinforced plastic (glass epoxy resin) or the like on which a copper foil pattern is formed, and a function in which the main functional circuit of the combination meter (vehicle display device 10) is carried. It is a circuit board.

As will be described later with reference to the drawings, the control wiring board 29 includes a control circuit for lighting the light sources 34 and 35 based on an electric signal from the vehicle, a communication circuit for communicating with the vehicle side, a microcomputer, and the like. And various circuits such as a power supply circuit for driving the light sources 34 and 35, and an IC 49 for causing the TFT module (the liquid crystal display module 11) to draw an image and other devices 57 and 58 are mounted.
In other words, the devices to be mounted include devices that generate electromagnetic noise such as a display control IC or generate heat.

  The metal wiring board 31 is a design circuit board on which necessary parts such as warning light sources 34 and 35, an analog gauge light source, and movements 39 and 39 are mounted according to design requirements based on the design of the combination meter. . The metal wiring board 31 is electrically connected to the control wiring board 29 via a connecting member, and warning light sources 34 and 35 and gauge light sources arranged at desired positions are supplied from the control wiring board 29. It is turned on and off based on an electrical signal.

  The metal wiring board 31 has a warning design (FIG. 1, reference numerals 17 to 19) mounted with light sources 34, 35, etc. for illuminating on the left and right sides and the upper side, and mounted with resistors therefor. Implement a part.

  The analog gauges 12 and 13 are composed of hands 22 and 24, dials 21 and 23, a color, a light guide, and the like, and the hands 22 and 24 are rotated by movements 39 and 39 mounted on the metal wiring board 31. Indicates the indicated value such as vehicle speed.

  As shown in FIG. 4, the metal wiring board 31 preferably includes a metal base 41, and a copper foil layer 43 that covers one side or both sides of the metal base 41 via an insulating layer 42 and constitutes a circuit. Consists of. The metal base 41 is preferably an aluminum plate having a thickness of about 0.3 mm. Aluminum plates are lighter and have higher thermal conductivity than carbon steel plates.

  The metal base 41 can be plastically deformed by a press or the like. In this example, as shown in FIG. 3, a concave portion 44 that accommodates the control wiring board 29 is integrally formed and protrudes toward the control wiring board 29. The convex part 45 was integrally formed.

  In FIG. 3, a case body 32 is made of, for example, black synthetic resin having a light shielding property, and a storage portion formed in a bathtub shape includes a metal wiring board 31, a control wiring board 29, an inner case 28, and a liquid crystal. The display module 11 is accommodated. A plurality of fastening portions are provided along the outer edge of the case body 32, and are screwed to fastening bosses provided on the facing 27, and are housed in the metal wiring board 31, the control wiring board 29, and the inner parts housed in the housing part. The case 28 and the liquid crystal display module 11 are fixed and held by sandwiching the case 27 between the facing 27.

  The cover 33 is a panel-like member made of synthetic resin or the like, and is fixed to the case body 32 from the back side of the meter with a hook or a double-sided tape.

By combining the above, the vehicle display device 10 shown in FIG. 2 is obtained.
That is, as shown in FIG. 2, the vehicular display device 10 includes a lens 26, a turnout 27, a liquid crystal display module 11, an inner case 28, a control wiring board 29, a metal wiring board 31, and a case body. 32 and a cover 33.

  The metal wiring board 31 is deformed along the unevenness formed by the components 57, 58 and the like mounted on the control wiring board 29, and is disposed close to the control wiring board 29. As a result, the vehicle display device 10 can be made thin.

Next, the system block configuration of the control wiring board 29 and the metal wiring board 31 will be described in detail.
As shown in FIG. 5, the vehicle display device 10 receives a display command command for instructing image display from the vehicle side via the signal line b <b> 1 by the communication circuit 47 of the control wiring board 29. The communication circuit 47 converts the signal level and transmits a display command to a microcomputer (hereinafter abbreviated as “microcomputer”) 48. The microcomputer 48 that has received the display command determines the display content of one screen based on the display command information.

  Note that the display command information is not limited to a single screen display command, such as a continuous screen display command such as an animation screen, a moving image file such as MPEG or MOV, a video signal such as navigation information or a camera image, or the like. It may be an instruction, and its type and form are arbitrary.

The microcomputer 48 confirms the priority order of the instruction processing in the program processing being executed, and transmits a display instruction command to the display control IC 49 via the signal line b2 at an appropriate timing.
Note that the communication format of the signal line b2 is generally a case where a CPU is built in the display control IC 49, and thus serial communication is often used. When the display control IC 49 does not include a CPU, it may be connected to an external path of the microcomputer 48 and receive a command.

The display control IC 49 that has received the display command command reads the image block data necessary for configuring one screen from the nonvolatile memory 51 and transfers it to the volatile memory 52.
The display control IC 49 uses the volatile memory 52 to create picture data for one screen based on the image block. When the volatile memory 52 confirms the completion of picture data for one screen, the display control IC 49 transfers it to the liquid crystal display module 11 via the signal line b3 in accordance with the drawing timing.

  In the moving image file display command such as MPEG or MOV, the data is stored in the nonvolatile memory 51, and once the data is expanded in the volatile memory 52, the data is transferred to the liquid crystal display module 11 by the display control IC 49. . Whether the image data is transferred collectively or partially depends on the contents of the display command received by the display control IC 49.

  The image data ideographic command such as navigation information and camera image may be fetched from the signal line (video signal) b6 to the display IC 49, and the display control IC 49 performs an appropriate process according to the display command command. Transfer to the liquid crystal display module 11.

  Next, a description will be given of control of warnings indicating warning information and the like by lighting of an analog gauge that indicates an instruction value such as a vehicle speed, and light sources arranged on the upper side and the left and right sides.

  A command command for instructing the memory position such as the vehicle speed, the engine speed, the water temperature level, and the fuel level is transmitted from the vehicle side to the communication circuit 47 of the control wiring board 29 via the signal line b1. The communication circuit 47 that has received the command command converts the signal level and transmits an instruction command command to the microcomputer 48. The microcomputer 48 that has received the instruction command command transmits the instruction information to the pointer driver 53 via the signal line b4.

  The pointer driver 53 drives the pointer 22 and the pointer 24 to a designated memory position. Similarly, lighting / flashing of the light sources 34 and 35 indicating warnings is controlled by the command command from the vehicle side via the communication circuit 47 → the microcomputer 48 → the signal line b5 → the shift register 54. .

The display control IC 49 mounted on the control wiring board 29 generates heat during use. It is an object of the present invention to efficiently discharge this heat and prevent a temperature rise, and its structure will be described next.
In FIG. 2, the display control IC 49 mounted on the control wiring board 29 is in direct contact with the metal wiring board 31 via the protrusion 45, and the heat generated by the display control IC 49 is generated by the metal wiring board 31. Is spread via.

Note that the contact state capable of transferring heat can be maintained by being pressed against the display control IC 49 by the deformation of the metal wiring board 31.
Further, the display control IC 49 may be brought into direct contact with the metal wiring board 31 or may be applied to the metal wiring board 31 through a good heat transfer material 56 having good thermal conductivity. The good heat transfer material 56 has a good thermal conductivity, and a hard sheet or a soft sheet having an adhesive layer on one or both sides is recommended.
In addition, by applying an elastic material such as a soft sheet to the good heat transfer material 56, the vehicle travels.

  The components that are directly or indirectly brought into close contact with the metal wiring board 31 are the display control IC 49, the heat generation component 57 around the display control IC 49, and the heat generation component 58 such as a power supply circuit.

  By adopting such a structure, the heat generated by the heat generating component mounted on the control wiring board 29 is diffused by the metal wiring board 31. As a result, an increase in the package temperature of each component can be suppressed, and the stable operation of each component can be maintained.

A supplementary explanation of thermal diffusion will be given based on FIG.
As shown in FIG. 6, the vehicle display device 10 is attached to, for example, a step portion of a vehicle instrument panel 60. The case body 32 of the vehicular display device 10 includes an upper ventilation hole 61 and a lower ventilation hole 62 in the lower part, and is covered with a cover 33 from the center to the upper part. The cover 33 constitutes a design surface.

A step portion of the instrument panel 60 of the vehicle includes a lower step 63, an upper step 64 above the lower step 63, and an opening 65 provided between the lower step 63 and the upper step 64.
For example, the turning 27 is applied to the lower stage 63, the upper ventilation hole 61 and the lower ventilation hole 62 are inserted into the opening 65, and the lower side of the cover 33 is applied to the upper stage 64.

  The occupant can see the lens 26 through the lower stage 63. Moreover, since the cover 33 which comprises a design surface exists on the upper stage 64, a passerby will visually recognize the beautiful cover 33 through a windshield, and aesthetics are maintained.

  A display control IC 49 mounted on the control wiring board 29 is in close contact with the convex portion 45 of the metal wiring board 31. Heat is transferred from the display control IC 49 to the metal wiring board 31 and diffused (conducted in the plate). On the other hand, relatively cool air 66 enters the case body 32 from the lower ventilation hole 62. The entered air 66 comes into contact with the metal wiring board 31 and rises while taking heat of the metal wiring board 31. The warmed air 67 rises based on the principle of natural convection and flows out from the upper ventilation hole 61 that is the upper opening. In other words, the metal wiring board 31 is efficiently cooled by the circulation of the air 66 and 67, and the temperature rise of the heat generating components 49, 57, and 58 is prevented.

  Although the vehicle display device 10 of the present embodiment is suitable for a vehicle-mounted combination meter, it may be applied to a vehicle display device for other uses or a general-purpose meter.

  The present invention is suitable for an in-vehicle combination meter.

  DESCRIPTION OF SYMBOLS 10 ... Display apparatus for vehicles, 11 ... Liquid crystal display module, 12, 13 ... Analog gauge, 29 ... Control wiring board, 31 ... Metal wiring board, 34, 35 ... Light source as optical components, 41 ... Metal base, 42 DESCRIPTION OF SYMBOLS ... Insulating layer, 43 ... Copper foil layer, 44 ... Concave part, 45 ... Convex part, 49 ... Display control IC as a control circuit device, 56 ... Good heat transfer material, 57, 58 ... Heat generating member as a control circuit peripheral device.

Claims (4)

A liquid crystal display module for displaying vehicle information;
A metal wiring board that can be deformed by mounting optical components for analog gauges or indicators for displaying vehicle information,
A control wiring board installed between the liquid crystal display module and the metal wiring board and mounted with a circuit for controlling the liquid crystal display module;
A display device for a vehicle, wherein a control circuit device or a control circuit peripheral device mounted on the control wiring board and controlling the liquid crystal display module is in close contact with the metal wiring board.   The metal wiring board includes a metal base and a copper foil layer that is covered with an insulating layer on at least one surface of the metal base to form a wiring pattern, and is configured as one wiring board. The vehicle display device according to claim 1, wherein:   The display device according to claim 1, wherein the metal wiring board is deformed along an unevenness of a component group mounted on the control wiring board, and is disposed in proximity to the control wiring board. . A liquid crystal display module for displaying vehicle information;
A metal wiring board that can be deformed by mounting optical components for analog gauges or indicators for displaying vehicle information,
A control wiring board installed between the liquid crystal display module and the metal wiring board and mounted with a circuit for controlling the liquid crystal display module;
A display device for a vehicle, wherein a control circuit device mounted on the control wiring board and controlling the liquid crystal display module or a control circuit peripheral device hits the metal wiring board via a heat transfer material.

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