JP2013148753A - Circuit board of vehicle display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board of a vehicle display device for suppressing influence of static electricity applied via a connector and the like on a display.SOLUTION: A circuit board of a vehicle display device includes: a connector 6 mounted to connect external equipment using a plurality of terminals including a ground terminal 62 for grounding and a terminal 61 for signal transfer; a ground pattern 71c which includes a conductive member and is connected to the ground terminal 62 for grounding; signal lines 71a, 71b connected to the terminal 61 for signal transfer; and electronic components C1, C2, R1, C3 and Z mounted by being connected to the ground pattern 71c and the signal lines 71a and 71b. A land (first connection section) 74a where the electronic components C1, C2, R1, C3 and Z and the ground pattern 71c are solder-connected is provided to be closer to the ground terminal 62 side than a land (second connection section) 74b where the electronic components C1, C2, R1, C3 and Z and the signal lines 71a and 71b are solder-connected.

Description

  The present invention relates to a circuit board of a display device for a vehicle, and is suitable for, for example, a configuration for performing communication with an external device and supplying power using a connector.

  As a technique related to countermeasures against static electricity of liquid crystal display devices such as audio equipment, for example, a technique described in Patent Document 1 is known. In the liquid crystal display device described in Patent Document 1, conductive electrodes are formed on one side, respectively, and the first and second substrates facing each other and the first and second substrates are sandwiched between the first and second substrates. A liquid crystal composition and a polarizing plate provided on the other side of the first and second substrates, and a varistor characteristic between the first and second substrates (when charged by static electricity with a relatively high voltage) Ceramics exhibiting electrical properties) are sandwiched. In the technique described in Patent Document 1, by adopting the above configuration, occurrence of display density unevenness due to static electricity generated in the manufacturing process is suppressed.

Japanese Patent Laid-Open No. 5-158075

  In recent years, display devices typified by liquid crystal display devices have been provided in various electronic devices such as audio devices. On the other hand, in display devices, there are concerns about circuit damage and screen distortion due to the application of static electricity during the manufacturing process and use, and technological development is being advanced to reduce the effects of static electricity. .

  In particular, in a display device mounted on a vehicle, when static electricity is applied to an electric signal line from the vehicle side, a control device (for example, a graphic controller) for controlling display of the display device or the control device. There is a possibility that static electricity may be superimposed on the signal line from the display to the display, and the display image of the display may be disturbed.

  SUMMARY OF THE INVENTION Accordingly, in view of the above-described background, an object of the present invention is a technique for countermeasures against static electricity in a display device for a vehicle, and a circuit for a display device for a vehicle that suppresses the influence of static electricity applied through a connector and the like on a display It is to provide a substrate.

  The circuit board of the vehicle display device of the present invention comprises a connector mounted for connecting to an external device using a plurality of terminals including a grounding terminal and a signal transfer terminal, and a conductive member, and the grounding A ground pattern connected to the terminal for signal transmission, a signal transfer pattern connected to the terminal for signal transfer, and an electronic component connected to and mounted on the ground pattern and the signal transfer pattern, the electronic component The first connection part to which the ground pattern is connected by soldering is provided closer to the grounding terminal than the second connection part to which the electronic component and the signal transfer pattern are connected by soldering. It is characterized by.

  Further, the ground pattern is characterized in that the first connection portion connected to at least a connector-side electronic component mounted on the signal transfer pattern is provided.

  The present invention relates to a circuit board of a display device for a vehicle and can suppress an influence on a display device due to static electricity applied via a connector or the like.

The block diagram regarding the display apparatus for vehicles in embodiment of this invention. The figure which shows the example of the input circuit in embodiment same as the above. The figure which shows the example of another input circuit in embodiment same as the above. The figure which shows the wiring pattern of the circuit board in embodiment same as the above.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a circuit board of a display device for a vehicle according to the present invention will be described with reference to the drawings, taking an example applied to an instrument device.

  FIG. 1 shows a configuration of a display device for a vehicle according to the present invention. A display 1, a control circuit 2, a power supply circuit 3, an input circuit 4, a drive circuit 5, and a connector 6 are provided on a circuit board. Implemented and configured. In addition, the circuit board containing these structures is accommodated in the inside of the instrument apparatus A by the insulating housing | casing which consists of synthetic resins etc., and suppresses that the static electricity from the exterior of an instrument apparatus penetrate | invades inside. .

  The display 1 uses a device capable of displaying an image, such as an organic EL element or a liquid crystal display element having a backlight, and displays information related to a plurality of vehicle information. The display 1 is based on a control signal from the control circuit 2. It informs the user of the vehicle status.

  The control circuit 2 can be applied with an arithmetic circuit such as a microcomputer, inputs vehicle information based on signals from various sensors and switches of the vehicle, and stores the vehicle information and various programs stored in storage means such as a ROM. Display the desired vehicle information, for example, measured values such as the traveling speed of the vehicle, the cruising distance, the accumulated traveling distance, the operation indicators such as the headlamp, the direction indicator, and the gear position, and various alarms. Image information to be displayed on the display 1 can be generated and output to the display 1. The control circuit 2 includes a drive driver that generates a drive signal for causing the display 1 to display image information.

  The power supply circuit 3 generates a drive voltage for the control circuit 2 or the like using the power supply of the on-vehicle battery, and supplies power input via the connector 6 to the electronic component to be driven. In this case, the power supply circuit 3 inputs a power supply voltage (for example, 8 to 14 V) to the vehicle-mounted battery side via a vehicle start switch such as an ignition switch, and converts it into a desired voltage (for example, 5 V). Output.

  The input circuit 4 is connected to the connector 6 and the control circuit 2 and inputs vehicle information such as a status signal of a switch provided on the vehicle side and a communication signal from various sensors so that the control circuit 2 can input it. Circuit including a protection circuit and a communication driver.

  For example, a plurality of input circuits 4a are provided for each vehicle information, and as shown in FIG. 2, noise absorbing capacitors C1 and C2 and voltage dividing resistance elements with respect to a vehicle-side switch input inputted from a connector 6. Electronic components such as R1 are provided. As another input circuit 4b, as shown in FIG. 3, an electronic component including a Zener diode Z for a protection circuit of a communication driver and a capacitor C3 for load setting capacitance is provided.

  The drive circuit 5 can be applied with a driver IC connected to the connector 6 and the display 1, and is a circuit for driving the display 1 without going through the control circuit 2, such as LVDS (low voltage differential signal). Is converted into a drive signal for displaying on the display 1 and output. In this case, the drive circuit 5 outputs a digital RGB signal based on image information input via the connector 6 to the display 1.

  The connector 6 is a connecting member that is mounted on a circuit board and includes a plurality of terminals for connecting cables to various switches, power supplies, sensors, and the like on the vehicle side. This is an interface for inputting information to be displayed on the display 1 such as the above and driving power of various electronic components on the circuit board.

  Next, the wiring pattern 71 of the circuit board 7 near the connector 6 will be described with reference to FIG.

  The circuit board 7 is formed with a wiring pattern 71 connected to each terminal when the connector 6 is mounted. In this case, each terminal of the connector 6 is soldered after being inserted into the through hole 72 and connected to each wiring pattern 71, and is further screwed through a hole 73 for fixing the connector 6 provided in the circuit board 7. To be fixed. Even if the above-described through hole 72 is not used, it can be surface-mounted by soldering to each land provided on the surface of the circuit board 7.

  The wiring pattern 71 includes signal lines (signal transfer patterns) 71a and 71b connected to a signal transfer terminal 61 among the terminals of the connector 6, and a ground pattern (ground pattern) connected to the ground terminal 62 as a reference potential point. ) 71c and the like.

  Components such as the capacitors C1 and C2 and the resistor element R1 are mounted on the signal line 71a, and the capacitors C1 and C2 and the resistor element R1 are connected to the ground pattern 71c as reference potentials. At this time, the signal line 71a is disposed in the vicinity of the ground pattern 71c, and a land (first connection portion) 74a that solder-connects each of the electronic components C1, C2, and R1 to the ground pattern 71c is a signal line. It is provided closer to the ground terminal 62 of the connector 6 than a land (second connecting portion) 74b to be soldered to 71a.

  Therefore, even if static electricity is applied to the signal line 71a from an external device or a cable, the electronic device C1, C2, R1, the ground pattern 71c, the ground terminal 62, and the cable are connected to the outside of the instrument device A. Since it can be emitted, the influence on other electronic components and other signal lines can be reduced. In addition, by setting the direction of the electronic component so that it can easily flow from the signal line 71a to the ground terminal 62 side, static electricity can be efficiently transferred to the outside of the instrument device A without being bypassed or transmitted to other wiring or other electronic components. Can be released. Therefore, in particular, the influence on the signal line (for example, the input signal line of the display device 1) directly related to the display can be suppressed, and the malfunction of the display device 1 can be prevented.

  Further, in the circuit board 7, the ground terminal 62 and the electronic components C1, C2, R1 are connected by soldering only through the ground pattern 71c, so that static electricity can be discharged efficiently and in the shortest possible time. Therefore, for example, even in a multilayer circuit board in which signal lines and ground patterns are provided inside vias or the like, before static electricity is applied to the wiring pattern in the inner layer via signal lines 71 connected to the connector 6. Since it can discharge | release to the ground terminal 62 side via the ground pattern 71c of a surface layer, the bad influence to the wiring pattern of an internal layer and other electronic components connected to this can be suppressed.

  In this case, the path from the land 74a of the electronic components C1, C2, and R1 to the ground terminal 62 in the ground pattern 71c is wider than the signal line 71a, and the electronic components C1, C2, and R1 and the ground pattern 71c. By arranging the distance from the land 74a to the ground terminal 62 in the vicinity of 1 cm or less, the conductive efficiency from the electronic components C1, C2, R1 to the ground terminal 62 can be improved. The possibility that static electricity is applied to electronic components and other signal lines can be suppressed.

  Further, even in the signal line 71b in which the Zener diode Z and the capacitor C3 shown in FIG. 3 are mounted, the connection between the electronic components Z and C3 and the ground pattern 71c is the same as that of the signal line 71a described above. By configuring similarly, the same effect can be obtained. In this case, since it is not adjacent to the ground pattern 71c like the signal line 71a, by mounting the electronic components Z and C3 so as to straddle the signal line 71a, the above-described effect can be obtained, and a plurality of signal lines 71a, It is possible to take countermeasures against static electricity for 71b.

  Further, in the signal lines 71a and 71b, it is advantageous to apply the above-described configuration to the electronic components C1 and C3 that are connected to the ground and closest to the connector 6 because the possibility that static electricity can be discharged in the shortest time is increased. is there.

  In the circuit board 7 of such a vehicle display device, a connector 6 mounted for connecting to an external device using a plurality of terminals including a ground terminal 62 for grounding and a terminal 61 for signal transfer, and conductive A ground pattern 71c connected to the ground terminal 62 for grounding, signal lines 71a and 71b connected to the signal transfer terminal 61, and connected to the ground pattern 71c and signal lines 71a and 71b. Lands (first connecting portions) 74a that include electronic components C1, C2, R1, C3, and Z, and to which the electronic components C1, C2, R1, C3, Z and the ground pattern 71c are solder-connected, Provided closer to the ground terminal 62 than the land (second connecting portion) 74b to which the electronic components C1, C2, R1, C3, Z and the signal lines 71a and 71b are solder-connected. That.

  Therefore, the direction of the electronic components C1, C2, R1, C3, and Z is set so that the signal lines 71a and 71b can easily flow to the ground terminal 62 side, so that static electricity can be efficiently discharged out of the instrument device A. Therefore, in particular, it is possible to suppress an adverse effect on a signal line (for example, an input signal line of the display device 1) that is directly related to display and to prevent malfunction of the display device 1.

  The circuit board of the vehicle display device of the present invention has been described by way of example in the configuration of the above-described embodiment, but the present invention is not limited to this, and the present invention is also applicable to other configurations. It goes without saying that various improvements and display changes can be made without departing from the gist of the invention.

  The present invention relates to a circuit board of a vehicle display device that is mounted on a vehicle and displays various types of vehicle information. For example, the present invention relates to a vehicle display device that is mounted on a moving body including an automobile, a motorcycle, an agricultural machine, or a construction machine. Applicable.

1 Display 2 Control Circuit 3 Power Supply Circuit 4 Input Circuit 5 Drive Circuit 6 Connector 61 Signal Transfer Terminal 62 Ground Terminal (Ground Terminal)
71a, 71b Signal line (signal transfer pattern)
71c Ground pattern (ground pattern)
74a Land (first connection part)
74b Land (second connection part)
A Instrument device (Vehicle display device)
C1, C2, C3 capacitors (electronic components)
R1, R2 resistance elements (electronic components)

Claims (2)

A connector mounted to connect to an external device using a plurality of terminals including a terminal for grounding and a terminal for signal transfer;
A grounding pattern made of a conductive member and connected to the grounding terminal;
A signal transfer pattern connected to the signal transfer terminal;
An electronic component connected to and mounted on the ground pattern and the signal transfer pattern,
The first connection portion where the electronic component and the ground pattern are solder-connected is provided closer to the grounding terminal than the second connection portion where the electronic component and the signal transfer pattern are solder-connected. A circuit board for a display device for a vehicle.   2. The circuit board of a vehicle display device according to claim 1, wherein the ground pattern is provided with the first connection portion connected to at least a connector-side electronic component mounted on the signal transfer pattern. .

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