JPH0112699B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake light device for an automobile, and more particularly to a pressure-responsive brake light device whose brightness changes in response to the pressure force of a brake pedal and the brightness around the brake light.

Conventional automobile brake lights use the vehicle's battery as a power source, an incandescent light bulb as the light source, and a red filter that turns the brake lights on and off with a switch that turns on and off depending on the movement of the brake pedal. was. Brake lights must be bright enough to warn the vehicles behind you of danger, but if they are too bright, they will blind the drivers of the vehicles behind you, causing danger, and will also increase power consumption and cause battery damage. It can also cause over-discharge. Brake lights are used to notify following vehicles of danger and prevent accidents, but just as traffic lights also have several indications: flashing yellow, solid yellow, flashing red, and solid red, they notify following vehicles of danger. There is also no single type of danger. However, conventional brake lights only have the simplest indication of turning on and off, so even if the driver can change the display by stepping on the brake intermittently, there are restrictions on the types of displays, especially when the brake light is the most dangerous. There was no way to notify me when I braked suddenly.

In addition, because displays with a single brightness were used even though the outside illuminance was significantly different between daytime and nighttime, displays with sufficient brightness during the daytime could dazzle the drivers of following cars or be unnecessary. It was also a cause of wasted electricity. In addition, brake lights are red, the same color as taillights used at night, so if there is little difference in brightness from the taillights, the driver of the vehicle following will not be able to tell the difference, and there is a high risk of a rear-end collision when braking suddenly. It was big and warm.

An object of the present invention is to change the light intensity or brightness of a brake light in response to the pressing force of the brake, and to clearly notify the degree of danger by changing the light intensity according to the surrounding brightness to indicate a change in the control amount. An object of the present invention is to provide a press-responsive brake light device that can perform the following functions.

According to one embodiment of the present invention, the brake light is configured with a red light emitting diode circuit, and the power supplied between the battery power source and the brake light device is changed in response to the pressing force of the brake pedal and the brightness of the outside world. A control circuit is connected. This control circuit changes the brightness of the brake lights in response to the pressure applied to the brakes, allowing the driver of the following vehicle to be informed of the degree of danger, and changes the standard brightness of the brake lights in response to the brightness of the outside world. This prevents the driver of the following vehicle from being dazzled at night, and the standard brightness is also increased by the headlights of the following vehicle, so even if the brake light is illuminated by the headlight from behind, it is sufficient to confirm the brake light. It has the characteristics of being able to Furthermore, power consumption can be reduced by using a highly efficient light emitting diode as a light source.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing a basic embodiment of the present invention, in which a brake light 1 is connected to a power source 3 via a control circuit 2. In FIG. When the brake pedal 21 is not depressed, the control circuit 2 switches the brake light 1 to the power source 3.
When the brake pedal 21 is depressed, the electric power supplied to the brake light 1 is changed depending on the pressing force of the brake pedal 21.
Therefore, the brake light 1 changes its brightness in response to the pressing force of the brake pedal.

In addition, the brake switch can be used to simply flash the lights in exactly the same way as in the conventional system, and a light beam that changes in brightness can be separately provided to notify following vehicles of the operating state of the brakes.

Further, an element 26 whose resistance value changes with respect to external light is provided around the brake light 1, and is connected to the control circuit 2 to change the supplied power in response to the surrounding brightness.

When using a light emitting diode as a light source, for example, Ga _x Al _1-x As or
If a GaAs _y P _1-y red light emitting diode is used, it will not emit light of unnecessary wavelengths, and together with the difference in light emitting mechanism, high efficiency can be achieved. For example, with currently available Ga _x Al _1-x As red light emitting diodes, it is easy to obtain an efficiency that is about 50 times higher than that of an incandescent plus red filter. Light-emitting diodes made of GaAlAs and other materials made by vapor pressure controlled temperature difference liquid phase growth have superior efficiency and brightness compared to conventional ones. Furthermore, light emitting diodes are very suitable for performing the brightness modulation of the present invention because brightness can be easily controlled by forward current.

Various types of pressure sensitive elements can be used in the control circuit, and typical pressure sensitive elements include pressure sensitive conductive rubber, pressure sensitive semiconductor diodes, and other pressure sensitive elements. For example, pressure-sensitive conductive rubber has various characteristics such as A, B, and C as shown in Figure 2, and it is easy to select the appropriate material according to the characteristics of the pressing force of the brake pedal. It is becoming. The temperature characteristics are also flat from -40°C to +60°C, making it suitable for use in automobile environments. The pressing force can be sensed by inserting the brake pedal 21 between the brake pedal 21 and the push rod 24.

FIG. 3 is an example of a simple control circuit. Since it is impossible to control the power supplied to the light source using only a pressure-sensitive conductive material in terms of current capacity, it is preferable to use a control circuit using a bipolar transistor, FFT, or the like. By incorporating into the circuit an element whose resistance value changes depending on external light, it is possible to automatically control the reference brightness of the brake light. All elements such as photodiodes and phototransistors can be used.

In FIG. 3, when the brake pedal is depressed, the switch 22 is turned on and the control circuit is activated, and the resistance value of the pressure sensing element is lowered due to the push and pull force on the pressure sensing element 25, and the transistor _T2 is turned off. ₁ is on and the brake light emits brighter. 26 is an element such as a photodiode or a phototransistor whose resistance value changes with respect to external light.

FIG. 4 is an example of a brake light using a light emitting diode. The battery in the car is usually 12V.
are using. Therefore, it is only necessary to connect the units in series according to the required voltage per element and configure the unit in units of 12V. By installing a large number of units, if the unit stops lighting due to a defective light emitting diode, that unit can be easily replaced. Just replace it. _T3〜
T _o is the FET used to make the light emitting diode unit constant current. Since the current is constant, damage to the unit due to shorting of one element can be prevented.

A constant current method may be used such as using a bipolar transistor, but FETs have excellent temperature characteristics and are suitable for use in automobile environments.

A phototransistor or the like is installed in these units so that the amount of light emitted changes depending on the brightness of the outside world. As a result, the standard brightness of the brake light changes automatically, avoiding unnecessary brightness at night and providing sufficient brightness during the day.

FIG. 5 shows an example of the arrangement of brake lights. In FIG. 5a, the light emitting diode 1 lights up when a weak pressure is applied to the brake pedal, and as the pressure increases, it lights up in the direction of the arrows 2, 3, . . . n. All the lights up to n will light up when the brake pedal is pressed fully, such as when braking suddenly.

FIG. 5b shows an example of a circular arrangement.

As explained above, the present invention is capable of transmitting the amount of braking, especially in the daytime and at night, whereas conventional brake lights could only signal the following vehicle by simply turning them on and off. It is a device that constantly emits an appropriate amount of light by changing the standard brightness even in response to external brightness such as the above, and greatly reduces the risk of rear-end collisions with following vehicles, and its industrial value is extremely high.

[Brief explanation of drawings]

Figure 1 shows an example of the configuration of the brake pedal and control circuit.
FIG. 2 shows an example of the characteristics of pressure-sensitive conductive rubber, FIG. 3 shows an example of a control circuit, FIG. 4 shows an example of the structure of a light emitting diode unit, and FIG. 5 shows an example of the lighting structure of a brake lamp. 1... Brake lamp, 2... Control circuit, 3...
...power supply, 21...brake pedal, 22...brake lighting switch, 23, 25...pressure sensing element,
26...Photoresistance element.

Claims (1)

[Claims] 1. A brake light light source composed of a light emitting diode, a power supply, a pressure sensitive element whose electrical characteristics change in response to the pressing force of the brake pedal, and an external light amount detection device that detects the brightness around the brake light light source. a pressure-responsive brake light device, characterized in that the brightness of the brake light source is controlled by changing the electric power supplied to the brake light source by the external light amount detection element and the pressure sensitive element. .