JPH031674B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a display that displays various information such as vehicle operating status (e.g. vehicle speed, engine speed, coolant temperature, remaining fuel amount) and time by lighting a plurality of segments installed on the vehicle. The present invention relates to an improvement in a device for checking whether each segment of the device is illuminated.

In conventional display devices, all segments were lit when the display check switch was closed (ON) when the vehicle's key switch was not open (OFF). As a result, if the display check switch was accidentally turned on while driving, all driving displays would disappear and all segments would turn on.

The present invention was proposed in order to solve the above-mentioned problems, and the operating state of the vehicle obtained by the sensor is calculated in the calculation section and converted into a digital display signal. It has an indicator that displays the operating status, and a check circuit that lights up all the segments when the key switch of the vehicle is located at a position other than the ignition coil energized position and the starter motor operating position and the manual check switch is closed. The present invention relates to a vehicle display device characterized by the following. Therefore, the segment lighting check that lights up all segments of the display device is performed when the key switch is in a position other than the ignition coil energized position or the starter operating position and the display check switch is turned on, so false indications may occur while driving. Even if the check switch is turned on, the lighting of the segments of the display device is not checked and the operating status continues to be displayed.

Examples of the present invention will be specifically described below.

In the first embodiment shown in FIG. 1, a display 1 provided on the instrument panel of the vehicle displays the vehicle speed with three digits, and the 100's digit is either 1 or not displayed, so it has two segments. consisting of 10 and 1
The digit is a liquid crystal display consisting of 7 segments. The latch driver 2 turns each segment of the display 1 on and off in response to a signal from the shift register 3. The vehicle speed calculation circuit 4 calculates the vehicle speed based on the output signal corresponding to the vehicle speed of the vehicle speed sensor 5 connected to the output shaft of the transmission, and sends a vehicle speed display signal to the shift register 3. A constant voltage power supply 6 is connected to a battery 7 of the vehicle, and supplies voltage to the vehicle speed calculation circuit 4, shift register 3, and latch driver 2. An ignition key switch (hereinafter referred to as key switch) 8 is connected to the battery 7 and has OFF, ACC, IG, and ST terminals. The ACC terminal is a vehicle electrical accessory,
For example, the IG can only operate the radio, heater fan, wipers, etc., and at the same time supplies power to the ignition coil, it also supplies power to all of the vehicle's electrical circuits. The ST terminal is connected to the engine starter motor activation relay, and at the same time,
It is also connected to the IG terminal. The check circuit 9 consists of a segment check circuit 10 and a blanking circuit 11, and the segment check circuit 10 consists of diodes _D1 , _D2 , transistors _Tr1 , _Tr2 , and resistors _R1 to _R3 , and the A terminal is connected to the ACC. It is connected to a resistor _R4 connected to the terminal and to a check switch 12 which is grounded. Note that the check switch 12 is provided on the instrument panel. Further, the B terminal is connected to the IG terminal via a resistor _R5 , the C terminal is connected to the F terminal of the blanking circuit 11, and the D terminal is connected to the segment test terminal of the latch driver 2. The E terminal is connected to a constant voltage power supply 6. The blanking circuit 11 includes diodes D ₃ , D ₄ ,
It consists of transistors Tr ₃ , Tr ₄ and resistors R ₆ to R ₈ , and its G terminal is connected to the IG terminal via a resistor R ₉ .
The H terminal is connected to the blanking input terminal of the latch driver 2, and the I terminal is connected to the constant voltage power supply 6.

When the vehicle runs, the vehicle speed sensor 5 sends a signal according to the vehicle speed to the vehicle speed calculation circuit 4, which calculates the vehicle speed, and sends a signal to the shift register 3 to light up a segment displaying the calculated vehicle speed. sends the display signal to latch driver 2,
The display 1 digitally displays the vehicle speed.

By the way, if you set key switch 8 to ACC,
Since the check switch 12 is OFF, a voltage is applied to the A terminal and a voltage is generated at the D terminal, so the segment test terminal of the latch driver 2 is not grounded and no segment lighting check is performed. Furthermore, since no voltage is generated at the C terminal, the H terminal is grounded and the display signal input to the latch driver 2 is not erased.

Here, when the check switch 12 is turned on, the A terminal is grounded, a voltage is generated at the C terminal, and a voltage is generated at the H terminal of the blanking circuit 11 to erase each segment display signal of the latch driver 2. At the same time, since the D terminal is grounded, a current from the constant voltage power supply 6 is applied to the segment terminals of the latch driver 2, and the latch driver 2 is activated, causing all segments of the display 1 to light up.

Furthermore, when the key switch 8 is set to IG, the D terminal generates voltage and the H terminal is grounded, so the latch driver 2 uses the display signal from the shift register 3 to light the segment of the display 1 to display the vehicle speed. .

At this point, I turned on check switch 12 by mistake.
However, since voltage is applied to the B terminal, the display 1 continues to display the vehicle speed.

Therefore, only when the key switch 8 is set to ACC and the check switch 12 is turned on, all the segments of the display 1 will light up and you can confirm that the segments are lit.
Since the segment illumination check cannot be performed while the engine is running with IG on, the vehicle speed will continue to be displayed even if the check switch 12 is accidentally turned on while driving.

Incidentally, in a vehicle having a diesel engine, the present embodiment is the same as the above embodiment except that the IG position of the key switch 8 is set to the ON position, and thus functions in the same manner as the above embodiment.

In the second embodiment shown in FIGS. 2 to 4, parts common to the first embodiment will be described with the same reference numerals.

2 to 4, the display 20 has the same speedometer 1', tachometer 13, water temperature gauge 14, fuel gauge 15, and speed warning 16 as the display 1 of the first embodiment. The speedometer 1' is formed by a segment of liquid crystal and has a speed of 100
The digits digit is made up of two segments so that only "1" can be displayed, and the tens and ones digits are made up of seven segments so that 0 to 9 can be displayed.
The tachometer 13 displays one liquid crystal segment for every 100 revolutions from 0 rpm to 7500 rpm, and has 75 segments. Water temperature gauge 1
4 displays the water temperature by lighting one of the 10 liquid crystal segments. The fuel gauge 15 displays the remaining amount of fuel in a bar graph using 15 liquid crystal segments. The speed warning 16 consists of one liquid crystal segment and lights up when the vehicle speed exceeds 100 km/h. The microcomputer 17 calculates the vehicle speed based on the signal from the vehicle speed sensor 5, sends a display signal for displaying this vehicle speed to the shift register 3, and calculates the engine speed based on the signal from the rotational speed sensor 18, A display signal for displaying the number is sent to the shift register 3,
Furthermore, the water temperature is calculated based on the signal from the water temperature sensor 19, and a display signal indicating this water temperature is sent to the shift register 3. In addition, the remaining fuel amount is calculated based on the signal from the fuel sensor 21, and this fuel remaining amount display signal is sent to the shift register 3. It is sent to shift register 3. The rotational speed sensor 18 turns a reed switch ON and OFF by the rotation of a magnet driven by the rotor shaft of the engine distributor, and sends "H" and "L" signals to the microcomputer 17 according to the rotational speed. The water temperature sensor 19 is made of a thermistor and is installed in the cooling water of the engine, and sends a voltage corresponding to the temperature of the cooling water to the microcomputer 17.
The fuel sensor 21 is provided in the fuel tank of the vehicle, has a resistance value that is varied according to the amount of fuel, and provides a voltage to the microcomputer 17. The IG input circuit 22 connected to the IG terminal of the key switch 8 includes a transistor _Tr5 , resistors _R9 to _R11 , and a diode _D5 . The J terminal of this IG input circuit 22 is connected to the IG terminal, and the K terminal is connected to the display command terminal of the microcomputer 17. The ACC input circuit 23 forming a check circuit consists of a transistor Tr ₆ , resistors R ₁₂ to R ₁₄ , and a diode D ₆ , its L terminal is connected to the ACC terminal of the key switch 8 via the check switch 12 , and its M terminal is connected to the check circuit. is connected to a first input terminal of a decision circuit 24 forming a. The determination circuit 24 has a second input terminal connected to the K terminal, and an output terminal connected to the microcomputer 17. Further, the microcomputer 17 has a built-in lighting check program that forms a check circuit for checking whether each segment of the display 20 lights up based on the output signal "L" from the judgment circuit 24.

When the key of the key switch 8 is placed in the IG position and the engine is started to drive the vehicle, voltage is applied to the J terminal of the IG input circuit 22 and the K terminal is grounded, so that the microcomputer 17 is given a display output command. The microcomputer 17 calculates the vehicle speed based on the signal from the vehicle speed sensor 5, sends a display signal of this vehicle speed to the latch driver 2 via the shift register 3, and digitally displays the vehicle speed on the speedometer 1' of the display 20. Also,
The engine rotation speed at this time is detected and calculated by the rotation speed sensor 18 and the microcomputer 17,
A rotational speed display signal is sent to the latch driver 2 via the shift register 3, and the engine rotational speed is digitally displayed on the tachometer 13. Furthermore, the water temperature sensor 19 sends a signal according to the cooling water temperature to the microcomputer 17, which calculates the water temperature, and sends a display signal to the latch driver 2 via the shift register 3 to light up a segment according to the water temperature. , the water temperature is displayed on the water temperature gauge 14. The fuel sensor 21 sends a signal corresponding to the amount of fuel to the microcomputer 17, which sends a signal indicating the remaining amount of fuel to the latch driver 2 via the shift register 3.
The latch driver 2 lights up a segment corresponding to the remaining fuel amount to display the remaining fuel amount on the fuel gauge 15.
Further, when the vehicle speed exceeds 100 km/h, the microcomputer 17 sends a speed warning lighting signal to the latch driver 2 via the shift register 3 to display a speed warning. Note that the second
Since the input terminal becomes "L" because the K terminal becomes "L", and the judgment circuit 24 continues to output "H", the microcomputer 17 does not perform a segment lighting check operation.

Next, when key switch 8 is set to the ACC position,
Since no voltage is applied to the J terminal of the IG input circuit 22, the K terminal becomes "H" and the microcomputer 17 no longer commands display from each sensor. Further, the “H” output from the K terminal is sent to the determination circuit 24.

Here, if check switch 12 is OFF,
Since "H" is output to the M terminal of the ACC input circuit 23, the judgment circuit 24 outputs "H", so the microcomputer 17 does not start the segment check and nothing is displayed on the display 20. . Now, when the check switch 12 is turned on, a voltage is applied to the L terminal of the ACC input circuit 23, the M terminal becomes "L", the judgment circuit 24 outputs "L", and the microcomputer 17 lights up the segment. Sends a check signal. Then, this lighting check signal causes the microcomputer 17 to perform the check operation shown in the flowchart of FIG. That is, when the lighting check signal is input, all the segments of the display 20 are turned on at the same time, and if this continues for more than 3 seconds, all the segments are turned off at the same time. Next, tachometer 1
Automatically start checking each segment of 3.
First, the data counter T is set to 0, a signal to turn off the segment of the tachometer 13 is sent to the latch driver 2, and the timer changes this display output from 0.5 to 0.
Hold for 1 second, check the number of data counters at this time, and if T<75, latch driver 2
The display drive output to the latch driver 2 is turned off, the data counter T is set to 1, and the display drive output for lighting the first segment is sent to the latch driver 2 to light the first segment. In this way, the 75 segments of the tachometer 13 are sequentially changed from 1 to 1.
Turn the lights on and off one by one. Then, when the 75th segment is turned on, the number in the data counter T becomes T≧75, so the data counter T is set to 0 and the 75th segment is turned off. Next, the segment check of the fuel gauge 15 is started, first, data counter B is set to B = 0, the segment of fuel gauge 15 is turned off, then data counter B is set to 1, and the first Outputs the display drive of the segment to the latch driver 2,
Turn on the first segment. The timer holds the display drive output for 0.5 to 1 second, then checks the number B of the data counter, and since B≧15 is not found, the display drive output is turned off to turn off the first segment, and the data counter 13 is turned off.
is set to 2, the second segment lights up, and the timer holds the above display drive output for 0.5 to 1 second.
Repeat this until B = 15, and the fuel gauge will be 15 of 15.
Turn on and off the segments one by one, and when B≧15, set the data counter B to 0 and set the fuel gauge to 15.
Finish segment check. Next, a segment check of water temperature gauge 14 is automatically started,
Data counter A is set to 0 to turn off the segment, and then data counter A is set to 1. Then, it outputs a display drive signal that lights up the first segment of the water temperature gauge, operates the latch driver, and lights up the first segment. After a certain period of time (0.5 to 1 second) has elapsed by a timer, the number on counter A is checked, and if A≧10, the display drive output is turned off, data counter A is set to 2, and the second segment is lit. Thereafter, this process is repeated to turn on and off the 10 segments of the water temperature gauge 14 one by one. When A≧10, the data counter A is reset to 0 and the segment check of the water temperature gauge 14 is completed. Next, a segment check of the speedometer 1' is started. first,
Set data counter S to S=00. Then, a display drive signal is output to the latch driver 2 to display "00", "00" is displayed on the speedometer 1', and a timer is set to display "00" for a certain period of time (for example, 0.5~
1 second) Hold this, and when this time ends, check the number of data counters at this time, and
If not ≧99, the data counter S is set to S=11, the display drive output is sent to the latch driver 2, and "11" is displayed on the speed meter 1'. and,
Repeat this process and read "99" on the speedometer 1'.
is displayed and a certain period of time has elapsed, the data counter S is set to S because S≧99.
= 100, and "100" is displayed on the speedometer 1' for a certain period of time by the operation of the timer. Next, the microcomputer 17 checks whether it is operating properly using its own internal check circuit, and if it is not operating correctly, it sets the data counter S to display a fault display according to the location of the fault, and then drives the display. Turn on the output and hold the failure indication on speedometer 1' for a certain period of time using a timer. When this predetermined period of time has elapsed, the data counter S is set to "EE" and a display drive output is generated, the latch driver 2 is operated and the timer displays "EE" on the speedometer 1' for a predetermined period of time. Furthermore, if the microcomputer 17 is operating correctly, no failure indication is made, and the data counter S is immediately set to "EE".
"EE" is displayed on speedometer 1'. When the "EE" display appears, the lighting check for each segment and the circuit check are completed. Therefore, it has the same effect as the first embodiment, and also has a tachometer 13 and a water temperature gauge 1.
4. Since each segment of the fuel gauge 15 is lit one by one, it is easy to find that one of the many segments lined up in a bar graph is burnt out. In addition, it is also possible to check whether the microcomputer 17 is operating properly.

In the above embodiment, check switch 1
If 2 is turned ON temporarily, even if key switch 8 is set to a position other than ACC during segment check,
Segment checking is not stopped and continues until the end, but the key switch 8 is constantly checked during segment checking.
If you do this while checking the position of
The segment check can be stopped as soon as key switch 8 is set to a position other than ACC. This allows the display 20 to immediately display the operating status of the vehicle when the vehicle is driven quickly after the segment check has started.

In the third embodiment shown in FIG. 5, the same parts as in the first embodiment will be described with the same reference numerals.
In Figure 5, a battery 7 as a DC power source
The voltage from the circuit is selectively sent to each circuit by a key switch 8.

From the ACC terminal corresponding to the accessory (ACC) position, which is a position other than the ignition coil position of key switch 8, connect its anode side.
Via the diode D ₇ connected to the ACC terminal,
Display control circuit 4' (vehicle speed calculation circuit 4 of the first embodiment,
It consists of a shift register and a latch driver 2. ) is supplied with voltage to the voltage supply (Vcc) terminal, and also to other circuits operating at the accessory location.

Voltage is supplied from the ignition (IG) terminal of the key switch 8 to the voltage supply (Vcc) terminal of the display control circuit 4' via a diode _D8 whose anode side is connected to the IG terminal. , and other circuits operating at the ignition position are also supplied with voltage.

Note that these diodes D ₇ and D ₈ are for supplying voltage only to the Vcc terminal of the display control circuit 4', and are for eliminating malfunctions.

No wire is connected to the off (OFF) terminal of the key switch 8, and voltage is supplied from the start (ST) terminal of the key switch 8 only to other circuits for starting.

Further, a check switch 12 constituting the check circuit 9 is provided, and this check switch 12 is normally open, and is closed (on) while the switch is pressed during diagnosis. It's summery. One end of the check switch 12 is connected to ground, and the other end is connected to one end of the switch portion of the relay 25.

A voltage supply connection is made from the IG terminal of the key switch 8 to one end of a coil portion of a relay 25 as a diagnostic circuit deactivation mechanism constituting the check circuit 9, and the other end is grounded.

The switch portion of the relay 25 is normally closed, and opens when current flows through the coil portion of the relay 25, that is, when the key switch 8 is in the ignition position. In this open state, the check circuit 9 is inactive. The other end of the switch portion of this relay 25 is connected to a diagnosis (CHECK) terminal of the display control circuit 4'. The display control circuit 4' controls the key switch 8.
When a voltage is supplied to the ACC terminal or the IG terminal, a voltage is supplied to the Vcc terminal, and this voltage is the operating voltage of the display control circuit 4'. Further, a diagnostic signal is sent from the check circuit 9 to the CHECK terminal of the display control circuit 4', and in this case, the diagnostic operation is performed when the diagnostic signal is at zero voltage.

When the Vcc voltage is supplied, the display control circuit 4' outputs a diagnostic display signal if the diagnostic signal is zero voltage.
By supplying the signal to the display 1 connected to the display (DISP) terminal of the display control circuit 4', displaying, for example, "188" on the display 1, and lighting each display segment of the digital speed display 9. It is now possible to perform display diagnostics. Note that all display segments may be lit.

Further, the display control circuit 4' is supplied with Vcc voltage,
And if no diagnostic signal is supplied, i.e. when the key switch 8 is in the ignition position,
The vehicle speed can be displayed digitally, and in this case, the display control circuit 4' counts the number of pulses corresponding to the vehicle speed from the vehicle speed sensor 5 and displays the vehicle speed on the digital speed indicator 1. Incidentally, the pulse from the vehicle speed sensor 5 is supplied to a clock (CLOCK) terminal of the display control circuit 4'.

In order to determine whether there is any abnormality in each circuit as a digital speedometer, a reference clock generation circuit (not shown) is provided in place of the vehicle speed sensor 5, and a switch (not shown) is used to switch from display diagnosis to circuit diagnosis. This reference clock is thereby supplied to the CLOCK terminal of the display control circuit 4'. At this time, if the circuit is normal, a predetermined display such as "1EE" is displayed to the driver to notify the driver of the diagnosis result that the circuit is normal.

Since the configuration is as described above, the diagnostic circuit deactivation mechanism does not operate only by the accessory position of the key switch 8, and if the diagnostic switch is turned on (closed) at this time, the diagnostic circuit operates and the display diagnosis or Circuit diagnosis is performed.

Further, when the key switch 8 is in the ignition position, a diagnostic circuit deactivation mechanism operates, and at this time, the diagnostic circuit does not operate regardless of whether the diagnostic switch is opened or closed, and the vehicle speed is displayed.

FIG. 6 is an electrical circuit diagram showing a case where a vehicle electronic device diagnostic device as a fourth embodiment of the present invention is applied to a digital speedometer. In FIG. 6, the same symbols as in FIG. show something

Check switch 7 forming check circuit 6
However, connect one end to the ACC terminal of key switch 8,
The other end is connected to the CHECK terminal of the display control circuit 4'.

Further, a diode D9 is provided as a diagnostic circuit deactivation mechanism constituting the check circuit 9, and the anode side of this diode D9 is connected to the CHECK terminal of the display control circuit, and the cathode side is connected to the Vcc terminal of the display control circuit. .

Because of this structure, when the check switch 12 constituting the check circuit 9 is turned on (closed) in the accessory position, which is a position other than the ignition position of the key switch 8, a diagnosis signal is sent to the CHECK terminal of the display control circuit 4'. A voltage as a signal is supplied, and a diagnostic operation is performed according to positive logic opposite to that of the third embodiment, so that, for example, "188" is displayed on the digital speed display 1.
When the key switch 8 is in the ignition position, the voltage supplied from the IG terminal of the key switch 8 is applied to the display control circuit 4' by arranging the diode D9 in the opposite direction as a diagnostic circuit deactivation mechanism constituting the check circuit 9. Since no power is supplied to the CHECK terminal, the diagnostic circuit does not operate, and therefore only the vehicle speed is displayed on the display 1.

The fourth embodiment has substantially the same effects and advantages as the third embodiment.

FIG. 7 is an electrical circuit diagram showing a case where a vehicle display device according to a fifth embodiment of the present invention is applied to a digital clock, and in FIG. 7, the same symbols as in FIG. Indicates.

An LSI 4'' is provided as a display control circuit, and this LSI 4'' receives a stabilizing voltage from a battery 7 to its V terminal via a constant voltage circuit 6, so that it is always on. . Also,
A constant voltage is constantly supplied to the positive end of the digital clock display 1''.

When the check switch 12 constituting the check circuit 9 (which has substantially the same configuration, operation, and effect as in FIG. 6) is turned on at a position other than the ignition position of the key switch 8, the check circuit 9
Since switch 12 is closed, the negative end of digital clock display 1'' is connected to the diode array.
It is grounded through D ₁₀ and D ₁₀ so that all display segments of the digital display 1'' are displayed at once. When the key switch 8 is in the ignition position, it is connected from the IG terminal through the display interface 26 as a display control circuit. A display instruction signal is supplied to the display instruction (DISP) terminal of LSI 4'.

By inputting this display instruction signal, LSI4''
The time is output to the digital clock display 1'', and current flows from the IG terminal to the coil section of the relay 25, which serves as the diagnostic circuit deactivation mechanism.
The check circuit 9 is designed not to operate.
That is, the time is displayed on the digital clock display 1''.

Note that the hour/minute setting changeover switch 27 is
A zero set switch 28 is connected to the hour (H) terminal and minute (M) terminal of LSI 4'' and to the zero set (S) terminal of LSI 4'.

The present invention can also be used for diagnosing displays and electric circuits in electronic control devices such as anti-skid brakes and electronic fuel control circuits.

Furthermore, the present invention may be configured such that a separately provided diagnostic result display lamp is made to blink, or the shape of the segment of each embodiment of the present invention may be changed to display, for example, "OK". good.

As described in detail above, according to the vehicle electronic device diagnostic device of the present invention, the vehicle electronic device is made to perform only its original operation while the vehicle is running, and the vehicle electronic device is allowed to perform only its original operation while the key switch is in a position other than the ignition (IG) position. When the driver presses the diagnostic switch, there is an advantage that the circuit and display can be accurately diagnosed.

Furthermore, when the service engineer tries to diagnose the speedometer, the key switch is placed in the ACC position, so no voltage is applied to the ignition circuit, so there is no risk of runaway, and there is no risk of burnout of the ignition coil, allowing for safe diagnosis. It has the advantage that it can be done.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention, FIG. 2 is a front view of a second embodiment of the present invention, FIG. 3 is a circuit diagram of the second embodiment, and FIG. 4 is a circuit diagram of the above-mentioned circuit. FIG. 5 is a circuit diagram showing the third embodiment of the present invention, FIG. 6 is a circuit diagram showing the fourth embodiment of the present invention, and FIG. FIG. 7 is a circuit diagram showing a fifth embodiment of the invention. 1: Display, 2: Latch driver, 4: Vehicle speed calculation circuit, 5: Vehicle speed sensor, 8: Ignition key switch, 9: Check circuit, 12: Check switch, 17: Microcomputer, 18:
Rotation speed sensor, 19: water temperature sensor, 21: fuel sensor.

Claims (1)

[Claims] 1. A display device that calculates the driving state of the vehicle obtained by the sensor in a calculation unit and converts it into a digital display signal, lights up a segment based on the digital display signal, and displays the driving state of the vehicle, as described above. A display device for a vehicle, characterized in that it has a check circuit that lights up all the segments when the key switch of the vehicle is located at a position other than the ignition coil energized position and the starter motor operating position and the manual check switch is closed. . 2. A vehicle display device according to claim 1, comprising a check circuit that lights up all the segments when the key switch is in the accessory position and the check switch is closed. 3. A vehicle display device according to claim 1, wherein the check circuit lights up all segments at the same time. 4. The vehicle display device according to claim 1, wherein the display device displays vehicle speed numerically, and the check circuit displays all the numbers in each digit of the display device. 5. In claim 1, the display device displays vehicle operating conditions such as engine speed, cooling water temperature, and remaining fuel level in a band shape, and the check circuit turns each segment of the display on and off one by one. A vehicle display device characterized in that: 6. The vehicle display device according to claim 3, wherein the check circuit turns on all segments at the same time and then turns on and off each segment one by one. 7 In claim 2, the display device includes a speedometer that displays the vehicle speed numerically, a tachometer that displays the engine speed in a strip, a water temperature gauge that displays the engine cooling water temperature, and a strip that displays the remaining fuel amount. The check circuit turns on and off all segments of the display at the same time, and then
Turn on and off each segment of the tachometer one by one, turn each segment of the water temperature gauge on and off one by one, turn each segment of the fuel gauge on and off one by one, and display all numbers in each digit of the speedometer. A vehicle display device characterized by: 8. Claim 1 provides a check circuit that checks whether the arithmetic unit is operating correctly after lighting all the segments, and if there is a malfunction, it is activated to display it on the display. A vehicle display device comprising: 9. A vehicle display device according to claim 6, characterized in that it has a check circuit that immediately stops operation when a key switch is placed in an ignition coil energized position or a starter motor operating position during a check operation. .