JPH02234856A - Display device - Google Patents

Abstract

PURPOSE:To inform other vehicles such as following vehicle of the degree of speed of one's own vehicle by displaying the rotating speed of engine on a display means disposed outside of the vehicle in place of the operating quantity of accelerator pedal in automobile. CONSTITUTION:A ROM 2 in which its executive program is written and a quartz oscillator 7 for clock oscillation are connected to a MPU 1. In a sensor 3, the rotating speed of an engine is detected, and this detection signal is inputted to the MPU 1 through an one-short multi-vibrator 4. In the MPU 1, a determined control signal based on the detection signal inputted is outputted, to a 4-column 7-segment display 6 disposed outside of the vehicle through a decoder/driver 5. Hence, the rotating speed of the engine is indicated on a display 6, thereby precisely informing other vehicles such as following car of the degree of speed of its own vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a display device for displaying the engine rotation speed or the degree of engine rotation speed on the outside of an automobile.

[Conventional technology]

A display device is provided outside the automobile, and the display device displays a display change corresponding to a change in the degree of depression of an accelerator pedal,
Accordingly, a display device has been proposed that is configured to inform following vehicles etc. of the speed of the vehicle.

[Problems with conventional technology]

By the way, for example, when a car is moving from a flat road to a slope, or from a flat asphalt road to a gravel road, the speed will not increase no matter how hard you press the accelerator pedal. Sometimes.

Therefore, the gear is changed to increase the engine speed to achieve the desired speed. In this way, even if the accelerator pedal is depressed more, the speed of the car does not necessarily increase, so a display device that displays the change in the accelerator pedal depression to inform the speed of the car is used. had the problem that it sometimes did not match the actual situation. [Object of the Invention] In view of the above-mentioned conventional drawbacks, an object of the present invention is to provide a display device that can accurately inform following vehicles of the speed of an automobile.

[Key points of the invention]

According to the present invention, the above object is achieved by providing a display device including a display means for displaying information related to the rotational speed of an engine in an automobile on the outside of the automobile.

〔Example〕

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a block diagram of a display device according to the present invention. In the figure, a microprocessor unit (hereinafter referred to as MPU)
1 is the CPU, RAM, parallel input/output board,
It is a so-called one-chip microprocessor that has a built-in timer, clock oscillation circuit, etc. The program executed by the MPUI is written in the ROM2, and the ROM2 is electrically connected to the MPtJl via a data path, address bus, etc.

The output of the sensor 3 that detects the rotational speed of the engine is inputted to the one-shot multi-vibrator 4, and the output of the eight-shot one-shot mano-reflector 4 is inputted to the MP
It is entered into one of the input ports of the UI.

On the other hand, the output from the output port (16 bits) of the MPUI is input to a decoder/driver 5, and the output of the decoder/driver 5 is input to a 4-digit 7-segment display 6. Note that the crystal oscillator 7 is provided for clock oscillation.

Various sensors can be used as the sensor 3, and for example, a neon lamp or the like can be used as shown in FIG. In the figure, a neon lamp 9 is provided adjacent to the spark plug 8, and one electrode of the neon lamp 9 is connected to one end of an electric wire 11 wound around a high voltage lead-in cord lo to the spark plug 8. ing. Further, a resistor 1 is connected to the other electrode of the neon lamp 9.
2 and one lead of capacitor 13 are connected,
The other lead of the resistor l2 is grounded. Although the lead on the other side of the capacitor 13 is not shown, it is connected to the one-shot multi-hyperator 4,
From here, a trigger signal is supplied to the one-shot multi-by-break 4. As a means for detecting the engine rotation speed, for example, a vibration sensor such as a microphone or a pickup is installed at an appropriate location in the engine room, and the output of the vibration sensor is rectified, smoothed, amplified, etc. /D converter, and the digital value obtained by the A/D converter is input to the MP. The engine rotation speed can also be displayed on the 4-digit 7-segment display 6 by processing in U1.

The 4-digit 7-segment display 6 is constructed by arranging four 7-segment displays each having the size of a package of 20 cigarettes, such as Highlight, Seven Star, and Castor, in a suitable case. When this is attached to, for example, the rear hood of a car and displayed, the numerical value can be read from inside the car of a following car.

In the ROM 2, for example, a timer interrupt processing program is written which monitors the state of the input port to which the output of the one-shot multi-by-pass brake 4 is input. When the spark plug 8 sparks, the neon lamp 9 lights up accordingly,
A current flows through the resistor 12, and the resulting voltage drop is supplied to the one-shot multi-byte break 4 as a trigger signal via the capacitor 13. As a result, the one-shot multi-by-break 4 outputs a pulse with a constant pulse width to the input port of the MPUI. When the state of the input port changes from, for example, 'L' to 'H', the contents of the register operating as a counter in the MPUI or the RAM at a predetermined address are incremented by the interrupt processing. The processing is repeated every time the state of the input port changes as described above.On the other hand, in other interrupt processing of the ROM 2, for example, the register operating as the counter every second, etc. Processing is performed such as reading out the contents of , multiplying it by 60 and writing the contents to a predetermined address on the RAM, and clearing the contents of the registers and the like.

The CPU in the MPUI reads the content multiplied by 60 by the main program from the RAM and stores it in BCD.
and outputs its contents to the output port,
This process is updated every second, for example. The data is decoded by the decoder section of the decoder/driver 5 in accordance with the engine rotational speed data output to the output boat and input to the 4-digit 7-segment display 6 via the driver. Thereby, each segment is selectively driven and the rotation speed corresponding to the rotation speed data is set to the four rotation speeds.
The digits are displayed on the 7-segment display 6.

FIG. 3 is a block diagram showing an embodiment in which the engine speed is displayed on the outside of the vehicle. In the same figure, the program executed by the MPU 14 is stored in the ROM.
15, and the aiROM15 is electrically connected to the MPU 14 via a data path, an address bus, etc.

A vibration sensor 16 such as a microphone or a pickup is provided at an appropriate location in the engine room, and the output of the vibration sensor 16 is input to a detection circuit 17 that performs functions such as rectification, smoothing, and DC amplification. In addition, the detection circuit 17
The output of the comparator 18 is supplied to a comparator 18, and the output of the comparator 18 is supplied to one (one bit) of the input ports of the MPU14.

On the other hand, for example, 9 bits of the output port of the MPU 14 are connected to a controller 19, and the output of the controller 19 is supplied to the comparator 18 as a reference voltage.

The controller 19 has a plurality of resistors, switching elements, etc., as shown in FIG.
Various reference voltages are changed.

The other output port of the MPU 14 is supplied to a driver 20, and the output of the driver 20 is supplied to a display 21. Note that the crystal oscillator 22 is provided for clock oscillation.

FIG. 4 is a circuit diagram showing an example of a detailed configuration of the controller 19. In the same figure, the resistor Ro has a resistor R1
to R, and ground via switching elements S1 to S9 such as transistors and FETs (connected to the common power supply line)
has been done. Each control terminal, for example, a gate, of the switching element selects one of the resistors R1 to R by setting any one of the output bauds P+ to P9 of the MPU 14 to a "'H'° level. , the resistance R
A divided voltage output between o and any one of the resistors R+ to R9 can be obtained across the terminal. Note that a voltage stabilized by, for example, a Zener diode is supplied between the terminal D and the ground. Further, the voltage generated across the terminal is supplied as a reference voltage to the comparator 18 shown in FIG.

FIG. 5 is a circuit diagram showing an example of a detailed configuration of the driver 20 and the display 21. In the figure, the driver 20 is a transistor Tr. Trg to Trg, and the base of each transistor is a resistor Rl9 to R2?
The MPU 14 via a corresponding one of the
The light emitting elements LED1 to LED8 are output via corresponding one of the other output ports Pll+ to Pl8.
It is connected to one terminal of the corresponding one of them.

The other terminal of these light emitting elements LED1 to LED8 is connected to a positive terminal (not shown) of a power source via a corresponding one of the light emitting elements LEDIO to LED17.
+12V).

This display 21 is housed in a suitable container, for example,
It can be attached to the rear hood of a car, etc.

The operation of the display device of the present invention configured as above will be described below.

Vibrations within the engine room are detected by the vibration sensor 16 and converted into voltage changes corresponding to the magnitude of the vibrations. The voltage change is rectified by a diode (not shown) of the detection circuit 17, and the rectified output is smoothed by a filter (not shown) and amplified by a DC amplifier such as an operational amplifier, resulting in a change in DC voltage that is output to the converter 18. is input as the compared signal.

On the other hand, the MPU 14 operates the controller 19 by executing other programs. Referring to FIG. 4, for example, first, the output port P+ of the output baud}P+ to P9 is changed from the "L" level to the 'H'' level.
Then, since the switching element S becomes conductive, the terminal voltage of the resistor RI is supplied to the comparator 18 as a reference voltage. The output of the converter 18 is supplied to the input port of the MPU 14.
14 checks whether the input state of this input port has changed from, for example, the "L" level to the "H" level. If it has not changed, return the output port Pl to the original "L" level, and then change the output port P2 from the "L" level to "
Similarly to the above, the MPU 14 checks the state of the input port.If the state of the input port has not changed, it returns the output port P2 to the original "L" level, and the MPU 14 checks the state of the input port. P3 from “L” level to “H”
level, and the MPU 14 checks the status of the input port. Thereafter, such operations are sequentially repeated until reaching the output boat P9.

Then, the process returns to the operation of the output port }P+, and the above operation is repeated. The time required for one round of such operations is approximately 500 μs. The operation is performed such that the reference voltage of the comparator 18 changes stepwise from a high voltage to a low voltage.
If the state of the input port, i.e. the comparator 18
When the output changes from “L I1 level” to “H” level,
It is determined which of the output ports 1-P+ to P is at the "H" level, and based on this, the output ports Pro to PI output to the driver 20 are determined.
It is decided which of the 1+ and which ones will be set to “H” level.
That's how it runs.

The compared signal of the comparator 18 is set to be maximum when the engine is at full rotation, and the difference between the voltage of the compared signal when the engine is stopped and the maximum voltage is determined, and this is used in the embodiment. In this case, the resistors Re to R9 of the controller 19 are determined so that each voltage is divided into nine stages and supplied to the converter 18 as a reference voltage. For example, the maximum voltage is 5V, and the voltage of the compared signal when the engine is stopped is 0.6V.
Then, the difference is 4.4■. Therefore, by operating the output ports P+ to P9, the converter 8 receives a reference voltage of 4.4V, 3.9V, 3V.
．． 4 2 V, 2.9 3 V, 2. 4 4 V,
1. 96■, 1.47V, 0.98V, 0.49V (
7) Voltages are applied sequentially. If it is assumed that the voltage when the rotation of the engine is stopped, that is, 0.6V, is supplied as the comparison signal, the controller will be operated one day in sequence as described above, and eventually,
When the output port P9 becomes "H" level, the converter 18 outputs 0. A reference voltage of 49 V is supplied. As a result, the voltage of the compared signal of the comparator 18 becomes higher than the reference voltage, and the output of the comparator 18 changes from the "L" level to the "H" level.

As a result, the MPU 14 sets only Pl8 of the output port output to the driver 20 to the "H" level.
Therefore, when the engine is stopped, only the LED 9 in FIG. 5 lights up.

When the engine speed increases a little, for example, 1. When 70 V is supplied to the comparator 18, the output port P7 becomes "H" level and the comparator 18 outputs 1. 4 TV
When the reference voltage of the MPU 1 is supplied, the output of the converter 18 becomes "H" level.
4 are output ports Pl& and PI? which output to the driver 20. is set to "H" level, and the output port peaO is returned to "L" level. Therefore, in this case, LED7, LED8, LEDIO, and LEDII in FIG. 5 are lit.

When the engine reaches full rotation and 5V is supplied to the comparator 18 as the compared signal, the output port P becomes the "HI1" level and a reference voltage of 4.4■ is applied to the comparator 18. When supplied, the output of the converter 18 becomes "H" level. by this. , the MPU 14 has an output port P1 that outputs to the driver 20. to PAT are set to "H" level. Therefore, when the engine is running at full speed,
For example, green LEDs 1 to LE excluding LED 9 in FIG.
All D17 lights up. Further, in the above embodiment, the light emitting element is composed of an LED, but it can also be composed of an incandescent light bulb.

As described above, with the above configuration, the light emitting display of the display can be displayed by expanding and contracting in the left and right directions according to the degree of engine rotation speed. [Effects of the Invention] As described in detail above, the present invention According to , the display device is configured to display information related to the engine speed outside the vehicle, making it possible to accurately inform following vehicles of the speed of the vehicle, thereby contributing to traffic safety. can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a display device of the present invention, Fig. 2 is a schematic configuration diagram showing an example of a sensor that detects the engine rotation speed, and Fig. 3 is a display of the engine rotation speed outside the vehicle. FIG. 4 is a circuit diagram showing an example of a detailed configuration of a controller, and FIG. 5 is a circuit diagram showing an example of a detailed configuration of a driver and a display. l...MPU, 2...ROM, 3...sensor, 5...decoder/driver, 6...4-digit 7-segment display. Patent applicant Kumapack Co., Ltd.

Claims (2)

[Claims] (1) A display device comprising display means for displaying the engine rotational speed of an automobile on the outside of the automobile. (2) A display device comprising display means for displaying the degree of rotational speed of an engine in an automobile on the outside of the automobile.