Circuit board for vehicle display device

Abstract

To provide a circuit board for a vehicle display device that can be applied to both two-wire sensor elements and three-wire sensor elements and can suppress noise.SOLUTION: A circuit board 24, on which a microcomputer 60 that displays the vehicle speed on a display unit 50 is mounted, includes a terminal P2 that receives a detection signal S1 indicating vehicle speed information from a sensor element 40a, a second acquisition circuit 22 that converts the detection signal S1 into a conversion signal S2 readable by the microcomputer 60 and outputs the converted signal to the microcomputer 60, a conductive pattern L2 that provides electrical continuity between the second acquisition circuit 22 and the terminal P2, a ground pattern GP, and a reverse connection protection diode D provided at the end of the conductive pattern L2 on the terminal P2 side. A mountable area A1 is formed in the conductive pattern L2 where a resistor can be mounted to provide electrical continuity between the conductive pattern L2 and the ground pattern GP.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a circuit board for a vehicle display device. [Background technology]

[0002] The rotation detection device described in Patent Document 1 comprises a magnetic detection element and an electrical cord connected to the magnetic detection element, and this electrical cord consists of three lines in total: two electrode supply lines (positive power supply and negative power supply) to the magnetic detection element and one signal output line from the magnetic detection element. The magnetic detection means of the rotation detection device described in Patent Document 2 includes a pair of reeds corresponding to a power supply line to the magnetic detection means and an output line from the magnetic detection means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4432027 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-83231 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Documents 1 and 2, there are two types of sensor elements for rotation detection devices: three-wire sensor elements, which have three lines connected, and two-wire sensor elements, which have two lines connected. This requires separate circuit boards for each type. In particular, if conductive patterns corresponding to each line are formed on the circuit board for a three-wire sensor element, an extra conductive pattern is generated when the circuit board is used for a two-wire sensor element, and this extra conductive pattern transmits and receives noise, which is undesirable.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a circuit board for a vehicle display device that can be applied to both two-wire sensor elements and three-wire sensor elements and can suppress noise. [Means for solving the problem]

[0006] In order to achieve the above object, a circuit board for a vehicle display device according to a first aspect of the present disclosure comprises: A circuit board for a vehicle display device on which a control unit for displaying a vehicle speed on a display unit is mounted, a terminal for inputting a detection signal indicating vehicle speed information from the sensor element; a capture circuit that converts the detection signal into a conversion signal that can be read by the control unit and outputs the conversion signal to the control unit; a conductive pattern that electrically connects the capture circuit and the terminal; The ground pattern and a reverse connection protection diode provided at an end of the conductive pattern on the terminal side, The conductive pattern has a mountable area on which a conductive means for establishing electrical continuity between the conductive pattern and the ground pattern can be mounted.

[0007] In order to achieve the above object, a circuit board for a vehicle display device according to a second aspect of the present disclosure comprises: A circuit board for a vehicle display device on which a control unit for displaying a vehicle speed on a display unit is mounted, a terminal for supplying power to the sensor element while receiving a detection signal indicating vehicle speed information from the sensor element; a capture circuit that converts the detection signal into a conversion signal that can be read by the control unit and outputs the conversion signal to the control unit; a utilization conductive pattern that electrically connects the capture circuit and the terminal; a floating pattern which is an unused conductive pattern different from the utilized conductive pattern; a ground pattern; The floating pattern has a mountable area on which a conductive means for establishing electrical continuity between the floating pattern and the ground pattern can be mounted, The conductive means is mounted in the mountable area.

[0008] In order to achieve the above object, a circuit board for a vehicle display device according to a third aspect of the present disclosure comprises: A circuit board for a vehicle display device for mounting a control unit that displays a vehicle speed on a display unit, a terminal to which a detection signal line of the sensor element can be connected; a first mountable area in which a capture circuit can be mounted, the capture circuit converting a detection signal indicating vehicle speed information from the sensor element into a converted signal readable by the control unit and outputting the converted signal to the control unit; a conductive pattern extending between the first mountable area and the terminal; a second mountable area located at an end of the conductive pattern on the terminal side, where a reverse connection protection diode can be mounted; a ground pattern; A third mountable area is formed at the end of the conductive pattern on the side of the first mountable area opposite the second mountable area, in which a conductive means for establishing electrical continuity with the ground pattern can be mounted. [Effects of the Invention]

[0009] According to the present disclosure, noise can be suppressed while being applicable to both two-wire sensor elements and three-wire sensor elements. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram of a vehicle display device according to a first embodiment of the present disclosure. [Figure 2] 1 is a schematic cross-sectional view of a vehicle display device according to a first embodiment of the present disclosure. [Figure 3] FIG. 10 is a block diagram of a vehicle display device according to a second embodiment of the present disclosure. [Figure 4] FIG. 10 is a diagram showing a surface of a circuit board according to a second embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram showing the back surface of a circuit board according to a second embodiment of the present disclosure. [Figure 6] FIG. 10 is a block diagram of a circuit board before components are mounted according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] First to third embodiments of the present disclosure will be described with reference to the drawings. The first embodiment is a circuit board connected to a three-wire sensor element by three lines (power supply line, ground line, and detection signal line). The second embodiment is a circuit board that is connected to a two-wire sensor element by two lines (a power line and a ground line). The third embodiment is a circuit board before components of the circuit board unit of the first and second embodiments are mounted. The circuit boards of the first and second embodiments are applied to a display device, which is a vehicle display device mounted on a vehicle such as a four-wheeled automobile or a two-wheeled automobile. The first to third embodiments will be described in order below.

[0012] (First embodiment) The vehicle display system 1 includes a vehicle display device 10 and a sensor element 40a. The vehicle display device 10 includes a circuit board unit 20a and a display unit 50. The sensor element 40a is a Hall element that detects the rotation of rotating bodies such as gear teeth, front hub, etc. The sensor element 40a is a three-wire sensor and is connected to the circuit board unit 20a by three lines: a power supply line Lv, a ground line Lg, and a detection signal line Ld. The sensor element 40a detects the rotation speed of the rotor as the vehicle speed and outputs a detection signal S1 to the circuit board unit 20a via a detection signal line Ld. The detection signal S1 is composed of a pulse wave with a duty ratio that corresponds to the vehicle speed. The sensor element 40a receives power via a power supply line Lv and transmits this power to a ground pattern GP of the circuit board 24 (described later) via a ground line Lg.

[0013] The circuit board unit 20a includes a circuit board 24, a second acquisition circuit 22, a power supply circuit 23, a microcomputer 60, a connector 65, and a reverse connection protection diode D.

[0014] As shown in FIG. 2, the display unit 50 is located on the front side (viewer side) of the circuit board unit 20a. The display unit 50 includes a display panel 51 and a backlight unit 52 . The display panel 51 is a TFT (Thin Film Transistor) type liquid crystal display panel. Under the control of the microcomputer 60, the display panel 51 displays an image including vehicle speed information. The backlight unit 52 is located behind the display panel 51, and illuminates the display panel 51 under the control of the microcomputer 60. The backlight unit 52 includes a plurality of LEDs (Light Emitting Diodes) as light sources.

[0015] The microcomputer 60 includes a CPU (Central Processing Unit), a GDC (Graphics Display Controller), a memory, etc., and controls the display unit 50. The microcomputer 60 receives the converted signal S2 from the second acquisition circuit 22, recognizes the vehicle speed, and displays the recognized vehicle speed on the display panel 51 as vehicle information.

[0016] The circuit board 24 is a printed circuit board on which components can be mounted on both the front surface 24F and the back surface 24B. A microcomputer 60 and a connector 65 are mounted on the back surface 24B.

[0017] As shown in FIG. 1, the circuit board 24 includes terminals P1 to P3 to which the connector 65 is connected, a plurality of conductive patterns L1 to L3, a ground pattern GP, ​​a mountable area 21A in which the first capture circuit 21 (see FIG. 3 of the second embodiment described later) can be mounted, a mountable area 22A in which the second capture circuit 22 can be mounted, a mountable area DA in which the reverse connection protection diode D can be mounted, a mountable area CA in which the capacitor C (see FIG. 3 of the second embodiment described later) can be mounted, and mountable areas A1 to A3 in which the resistors R1 to R3 (see FIG. 3 of the second embodiment described later) can be mounted. In this embodiment, the second capturing circuit 22, the power supply circuit 23, the microcomputer 60, and the reverse connection protection diode D are mounted on the circuit board 24, but the first capturing circuit 21, the resistors R1 to R3, and the capacitor C are not mounted on the circuit board 24.

[0018] Terminal P1 is connected to sensor element 40a via power supply line Lv, terminal P2 is connected to sensor element 40a via detection signal line Ld, and terminal P3 is connected to sensor element 40a via ground line Lg.

[0019] The power supply circuit 23 is connected to the terminal P1 via the conductive pattern L1. The power supply circuit 23 converts (boosts or drops) the voltage from the power supply Vc to a voltage suitable for the sensor element 40a and outputs the converted voltage. This converted voltage is supplied to the sensor element 40a via the conductive pattern L1, the terminal P1, and the power supply line Lv.

[0020] The second acquisition circuit 22 is mounted in the mountable area 22A. Specifically, the second acquisition circuit 22 is composed of electronic components such as a transistor TR, a capacitor, and a resistor, and is configured by mounting these electronic components on a conductive pattern in the mountable area 22A. The second acquisition circuit 22 is connected to the terminal P2 via the conductive pattern L2. The second acquisition circuit 22 converts the detection signal S1 into a conversion signal S2 that can be read by the microcomputer 60. The transistor TR of the second acquisition circuit 22 is turned on and off by the detection signal S1, thereby outputting the conversion signal S2 as a square wave whose constant voltage periodically switches between high and low. The second acquisition circuit 22 and the mountable area 22A are installed near the microcomputer 60 to suppress noise from being introduced into the conversion signal S2. This is because the conversion signal S2 has lower noise resistance than the unconverted detection signal S1.

[0021] A mountable area DA is formed at the end of the conductive pattern L2 closer to terminal P2. The mountable area DA is composed of lands for mounting discrete components. A reverse connection protection diode D is mounted in the mountable area DA. The reverse connection protection diode D is arranged so that its cathode terminal faces terminal P2, and is provided to protect the internal circuitry of the circuit board unit 20a from high voltage in the event of reverse line connection. The reverse connection protection diode D is arranged closer to terminal P2 from the perspective of functionality and board design. Since the mountable area DA and the mountable area 22A need to be arranged on both ends of the conductive pattern L2, the length of the conductive pattern L2 is longer than that of the conductive pattern L3. In this embodiment, the portion of the conductive pattern L2 between the reverse connection protection diode D and the second acquisition circuit 22 is used as a current path for the detection signal S1, but in the second embodiment described later, it becomes a floating pattern Lf (see Figure 3) that is not used.

[0022] One end of the conductive pattern L3 is connected to the terminal P1 via the conductive pattern L1, and the other end of the conductive pattern L3 is connected to the mountable area 21A. A mountable area CA is formed on the conductive pattern L3. The mountable area CA is composed of lands for mounting discrete components. No capacitor C is mounted in the mountable area CA. Therefore, the conductive pattern L3 is formed as a floating pattern Le through which no electrical signal flows. Because the floating pattern Le is shorter than the floating pattern Lf in the second embodiment, it is less likely to function as an antenna for transmitting and receiving noise.

[0023] (effect) According to the first embodiment described above, the following effects are achieved. The circuit board 24, which is an example of a circuit board for a vehicle display device and on which a microcomputer 60, which is an example of a control unit that displays the vehicle speed on a display unit 50, is mounted, includes a terminal P2 that receives a detection signal S1 indicating vehicle speed information from the sensor element 40a, a second capture circuit 22, which is an example of a capture circuit that converts the detection signal S1 into a conversion signal S2 readable by the microcomputer 60 and outputs the converted signal S2 to the microcomputer 60, a conductive pattern L2 that provides electrical continuity between the second capture circuit 22 and the terminal P2, a ground pattern GP, ​​and a reverse connection protection diode D provided at the end of the conductive pattern L2 on the terminal P2 side. The conductive pattern L2 has a mountable area A1 on which a resistor R1, which is an example of conductive means for providing electrical continuity between the conductive pattern L2 and the ground pattern GP, ​​can be mounted. The above configuration is a configuration in which the circuit board 24 is applied to the three-wire sensor element 40a, but even if this configuration is applied to the two-wire sensor element 40b, a resistor R1 that grounds the unnecessary conductive pattern L2 can be provided in the mountable area A1, thereby preventing the conductive pattern L2 from transmitting and receiving noise.

[0024] (Second embodiment) Next, a second embodiment will be described with reference to Figures 3 to 5. The following description will focus on the differences from the first embodiment. The sensor element 40b is a two-wire sensor and is connected to the circuit board unit 20b by two lines: a power supply line Lv and a ground line Lg. The sensor element 40b superimposes a detection signal S3 indicating the vehicle speed on the power supplied to the power supply line Lv. That is, in this embodiment, the power supply line Lv serves both the functions of the detection signal line Ld and the power supply line Lv in the first embodiment.

[0025] The first capturing circuit 21 is mounted in the mountable area 21A, and the capacitor C is mounted in the mountable area CA. This allows the conductive pattern L3 to provide electrical continuity between the first capturing circuit 21 and the conductive pattern L1. The capacitor C has the functions of removing noise and stabilizing voltage, and passes the detection signal S3, which is a square wave.

[0026] The first acquiring circuit 21 receives the detection signal S3 flowing through the conductive pattern L3 and converts the detection signal S3 into a conversion signal S4 that can be read by the microcomputer 60. The first acquiring circuit 21 is composed of an operational amplifier OP, a capacitor, a resistor, etc. The operational amplifier OP amplifies the detection signal S3 and outputs the conversion signal S4. The terminal Pi to which the conversion signal S4 of the microcomputer 60 is input is the same as the terminal Pi to which the conversion signal S2 in the first embodiment is input.

[0027] In the second embodiment, the second capture circuit 22 is not mounted in the mountable area 22A, and the reverse connection protection diode D is not mounted in the mountable area DA either. Therefore, the conductive pattern L2 becomes a floating pattern Lf through which no electrical signal flows.

[0028] As described above, the mountable area DA and the mountable area 22A need to be arranged on both ends of the conductive pattern L2, so the length of the conductive pattern L2, which becomes the floating pattern Lf, is longer than the conductive pattern L3. The length of the floating pattern Lf is, for example, 15 cm to 25 cm, and as an example, about 20 cm (including ±1 cm).

[0029] As shown in FIGS. 4 and 5, the floating pattern Lf (conductive pattern L2) is formed across both the front surface 24F (first surface) and the back surface 24B (second surface) of the circuit board 24 through vias B1 to B3. 4, the floating pattern Lf (conductive pattern L2) starts at terminal P2 on the front surface 24F of the circuit board 24 and extends in the following order: terminal P2 → mountable area DA → mountable area A2 → mountable area A3 → via B1. The mountable area A2 is formed immediately after the mountable area DA, and the mountable area A3 is formed immediately before the via B1. Regarding the front-to-rear directions between "immediately after" and "immediately before," the direction from terminal P2 toward the mountable area 22A in the conductive pattern L2 is defined as the front direction, and the direction from the mountable area 22A toward terminal P2 is defined as the rear direction. 5, the floating pattern Lf (conductive pattern L2) extends from via B1 to via B2 on the back surface 24B of the circuit board 24. Next, as shown in Fig. 4, the floating pattern Lf (conductive pattern L2) extends from via B2 to via B3 on the front surface 24F of the circuit board 24. Finally, as shown in Fig. 5, the floating pattern Lf (conductive pattern L2) extends from via B3 to the mountable area 22A on the back surface 24B of the circuit board 24, passing through the mountable area A1.

[0030] 3 to 5, resistors R1 to R3 are mounted in the mountable areas A1 to A3. The resistors R1 to R3 are jumper resistors, and are conductive elements for electrically connecting the floating pattern Lf to the ground pattern GP. The resistance value of each of the resistors R1 to R3 is 0 Ω. The resistance value of each of the resistors R1 to R3 is not limited to 0 Ω, as long as it has a low resistance value, for example, 10 Ω or less. As shown in FIG. 3, one end of the resistor R1 is connected to the end of the floating pattern Lf on the mountable area 22A side, and the other end of the resistor R1 is connected to the ground pattern GP. One end of the resistor R2 is connected to the end of the floating pattern Lf on the terminal P2 side, and the other end of the resistor R2 is connected to the ground pattern GP. One end of resistor R3 is connected between the connection points of resistors R1 and R2 in floating pattern Lf, and the other end of resistor R3 is connected to ground pattern GP. In particular, since the impedance of conductive pattern L2 is easily disturbed around via B1 (see Figure 4), providing resistor R3 around via B1 is expected to improve noise immunity. Since the floating pattern Lf is grounded by the resistors R1 to R3, the floating pattern Lf is prevented from becoming an antenna that transmits and receives noise.

[0031] (effect) According to the second embodiment described above, the following effects are achieved. The circuit board 24, on which the microcomputer 60 that displays the vehicle speed on the display unit 50 is mounted, includes a terminal P1 that receives a detection signal S3 indicating vehicle speed information from the sensor element 40b and supplies power to the sensor element 40b, a first capture circuit 21 that is an example of a capture circuit that converts the detection signal S3 into a conversion signal S4 readable by the microcomputer 60 and outputs the converted signal S4 to the microcomputer 60, a conductive pattern L3 that is an example of an available conductive pattern that connects the first capture circuit 21 and the terminal P1, a floating pattern Lf that is an unused conductive pattern different from the conductive pattern L3, and a ground pattern GP that is formed with a gap between the conductive pattern L3 and the floating pattern Lf. A mountable area A1 is formed in the floating pattern Lf where a resistor R1 that connects the floating pattern Lf to the ground pattern GP can be mounted. The resistor R1 is mounted in the mountable area A1. The above configuration is a configuration in which the circuit board 24 is applied to the two-wire sensor element 40b, and in this case, the floating pattern Lf that occurs is conducted to the ground pattern GP via the resistor R1, thereby preventing the floating pattern Lf from transmitting and receiving noise.

[0032] (Third embodiment) Next, a third embodiment will be described with reference to Fig. 6. The following description will focus on differences from the first embodiment. The third embodiment is a circuit board before various components are mounted in the circuit board unit of the first and second embodiments.

[0033] As shown in FIG. 6, the unmounted circuit board 20c includes terminals P1 to P3, a plurality of conductive patterns L1 to L3, a plurality of mountable areas 21A, 22A, A1 to A3, CA, and DA, and a ground pattern GP. The power supply circuit 23, the microcomputer 60, the second acquisition circuit 22, and the diode D are mounted on the pre-mounting circuit board 20c, thereby manufacturing the circuit board unit 20a according to the first embodiment. Furthermore, the power supply circuit 23, the microcomputer 60, the first acquisition circuit 21, the resistors R1 to R3, and the capacitor C are mounted on the pre-mounting circuit board 20c, thereby manufacturing the circuit board unit 20b according to the second embodiment.

[0034] (effect) According to the third embodiment described above, the following effects are achieved. (1) The pre-mounting circuit board 20c for mounting the microcomputer 60 that displays the vehicle speed on the display unit 50 includes a terminal P2 to which the detection signal line Ld of the sensor element 40a can be connected, a mountable area 22A as an example of a first mountable area in which a second acquisition circuit 22 can be mounted that converts a detection signal S1 indicating vehicle speed information from the sensor element 40a into a conversion signal S2 readable by the microcomputer 60 and outputs the converted signal to the microcomputer 60, a conductive pattern L2 extending between the mountable area 22A and the terminal P2, a mountable area DA located at an end of the conductive pattern L2 on the terminal P2 side and as an example of a second mountable area in which a reverse connection protection diode D can be mounted, and a ground pattern GP. A mountable area A1 as an example of a third mountable area in which a resistor R1 for establishing conduction between the conductive pattern L2 and the ground pattern GP can be mounted is formed at an end of the conductive pattern L2 on the mountable area 22A side opposite the mountable area DA. According to this configuration, even if a floating pattern Lf (conductive pattern L2) occurs when applied to the two-wire sensor element 40b, the floating pattern Lf is grounded via the resistor R1, thereby preventing the floating pattern Lf from transmitting and receiving noise.

[0035] (2) The pre-mounting circuit board 20c includes a terminal P1 that inputs a detection signal S3 indicating vehicle speed information from the sensor element 40b while supplying power to the sensor element 40b, a mountable area 21A that is an example of a fourth mountable area in which a first acquisition circuit 21 that converts the detection signal S3 into a conversion signal S4 readable by the microcontroller 60 and outputs the signal to the microcontroller 60 can be mounted, a conductive pattern L3 that extends between the mountable area 21A and the terminal P1, and a mountable area CA that is an example of a fifth mountable area in which a capacitor C that is an example of a conductive member formed on the conductive pattern L3 can be mounted. This configuration makes it possible to apply the sensor element 40a, 40b to both two-wire and three-wire types by changing the components mounted on the circuit board 20c before mounting. Specifically, by mounting the capacitor C and the first capture circuit 21 on the circuit board 20c before mounting, it becomes possible to apply the sensor element 40b to the two-wire type.

[0036] The present disclosure is not limited to the above-described embodiments and drawings. Modifications (including deletion of components) may be made as appropriate within the scope of the present disclosure. An example of such a modification is described below.

[0037] (Variation) In each of the above embodiments, the number of resistors R1 to R3 and mountable areas A1 to A3 can be changed as appropriate, and one or two of the resistors R1 to R3 or mountable areas A1 to A3 may be omitted. Also, three or more resistors R1 to R3 or mountable areas A1 to A3 may be provided. The resistors R1 to R3 may be any conductive means that provides electrical continuity between the floating pattern Lf and the ground pattern GP, ​​and may be, for example, a capacitor or solder. The floating pattern Le in the first embodiment may be electrically connected to the ground pattern GP via a conductive means such as a resistor, as in the second embodiment. In the above embodiments, the sensor elements 40a and 40b detect the vehicle speed, but they may also detect rotation, for example, the engine speed. Furthermore, in the above embodiment, the display unit 50 is not limited to a TFT-type liquid crystal display panel, and may be an organic electroluminescence display (OLED) or a DMD (Digital Mirror Device) type display device. [Explanation of symbols]

[0038] 1...vehicle display system, 10...vehicle display device 20a, 20b...circuit board unit, 20c...circuit board before mounting 21...first acquisition circuit, 22...second acquisition circuit, OP...operational amplifier, TR...transistor 23…Power circuit 24...circuit board, 24B...rear surface, 24F...front surface 40a, 40b...sensor elements 50...display section, 51...display panel, 52...backlight unit 60...microcomputer 65...Connector P1~P3, Pi... terminals, L1~L3... conductive patterns, Le, Lf... floating patterns, GP... ground pattern, B1~B3... vias, C... capacitors, D... reverse polarity protection diodes, R1~R3... resistors CA, DA, A1 to A3, 21A, 22A... Mountable areas S1, S3: detection signals, S2, S4: conversion signals Ld: detection signal line, Lg: ground line, Lv: power supply line, Vc: power supply

Claims

1. A circuit board for a vehicle display device on which a control unit for displaying a vehicle speed on a display unit is mounted, a terminal for inputting a detection signal indicating vehicle speed information from the sensor element; a capture circuit that converts the detection signal into a conversion signal that can be read by the control unit and outputs the conversion signal to the control unit; a conductive pattern that electrically connects the capture circuit and the terminal; The ground pattern and a reverse connection protection diode provided at an end of the conductive pattern on the terminal side, The conductive pattern has a mountable area on which a conductive means for establishing electrical continuity between the conductive pattern and the ground pattern can be mounted. Circuit board for vehicle display device.

2. A circuit board for a vehicle display device on which a control unit for displaying a vehicle speed on a display unit is mounted, a terminal for supplying power to the sensor element while receiving a detection signal indicating vehicle speed information from the sensor element; a capture circuit that converts the detection signal into a conversion signal that can be read by the control unit and outputs the conversion signal to the control unit; a utilization conductive pattern that electrically connects the capture circuit and the terminal; a floating pattern which is an unused conductive pattern different from the utilized conductive pattern; a ground pattern; The floating pattern has a mountable area on which a conductive means for establishing electrical continuity between the floating pattern and the ground pattern can be mounted, the conductive means is mounted on the mountable area; Circuit board for vehicle display device.

3. A circuit board for a vehicle display device for mounting a control unit that displays a vehicle speed on a display unit, a terminal to which a detection signal line of the sensor element can be connected; a first mountable area in which a capture circuit can be mounted, the capture circuit converting a detection signal indicating vehicle speed information from the sensor element into a converted signal readable by the control unit and outputting the converted signal to the control unit; a conductive pattern extending between the first mountable area and the terminal; a second mountable area located at an end of the conductive pattern on the terminal side, in which a reverse connection protection diode can be mounted; a ground pattern; a third mountable area capable of mounting a conductive means for establishing electrical continuity between the conductive pattern and the ground pattern, the third mountable area being formed at an end of the conductive pattern on the side of the first mountable area opposite to the second mountable area; Circuit board for vehicle display device.

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