JPH0356931B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a safety light device for a vehicle such as a bicycle tail light.

(b) Prior art This type of device was published in the Transportation Equipment Newspaper dated November 15, 1981, and as shown in Figure 1, it is a device for bicycles that has a light emitting diode 2 that is lit by a solar cell 1. A tail light device 3 is known.

This device consists of solar cells 1 arranged horizontally upward.
By charging the secondary battery 4 during the day, the light-emitting diode 2 is energized and lit at night, and the bicycle B is turned on.
This is to make car drivers aware of the existence of

In such a configuration, since the solar cell 1 is installed on the bicycle B, the light collecting area is limited, and therefore the charging capacity of the secondary battery 4 cannot be increased.
As a result, the current flowing when the light emitting diode 2 is turned on is kept low, and the brightness is low, making it easy to see in pitch darkness, but visibility deteriorates when exposed to the light of a car's headlights, making it difficult for Bicycle B to ride at night. There was a problem with the decrease in

(c) Purpose of the Invention In view of the above-mentioned problems, an object of the present invention is to reduce the current consumption of the safety lights and improve the visibility of the safety lights when necessary, thereby enabling safe driving.

(d) Structure of the Invention The structure of the present invention includes a solar cell, a secondary battery charged by the solar cell, a safety light lit by the secondary battery, and a detection means for detecting external light. The present invention is characterized in that it includes brightness increasing means for increasing the brightness of the safety light when the detecting means detects an illuminance of a predetermined level or more.

With this configuration, the safety light normally lights up at low current and low brightness when driving at night, so current consumption is small, and when external light from a car or the like is detected by the detection means, the brightness of the safety light increases and visibility improves.

(E) Embodiment An embodiment of the present invention will be described with reference to FIGS. 2 and 3. Reference numeral 5 denotes a safety light unit attached to the tail of the bicycle, in which a solar cell 7, a secondary battery 8, first and second light emitting diodes (hereinafter referred to as LEDs) 9, 10, etc. as safety lights are installed inside a translucent cover 6. It has built-in components attached to the board 11. These electric circuit elements are connected as shown in FIG. 3, and the solar cell 7 is exposed through the opening of the case 6 and receives sunlight S and external light W in a substantially horizontal direction such as the headlights of a car. It is slanted at a predetermined angle θ with the ground, and is oriented upward.

The secondary battery 8 is connected to the solar cell 7 via a rectifier 12, the first LED 9 is attached to the substrate 11 so as to be visible from the rear of the bicycle, and one end of the first LED 9 is connected to the secondary battery 8 via a manual switch 13.
, the other end is the first resistor R ₁ for current limiting, the first
The base of the first transistor Tr ₁ is connected to the negative electrode of the secondary battery 8 via the transistor Tr ₁ , and the base of the first transistor Tr 1 is connected to the second transistor whose base is connected in series to the solar cell 8.
The collector is connected to the fourth resistor at the midpoint between the third resistors R ₂ and R ₃ .
A midpoint between the switch 13 and the first LED 9 is connected via a resistor R ₄ to the collector of a second transistor Tr ₂ whose emitter is connected to the negative electrode of the secondary battery 8, respectively.

Further, the second LED 10 is attached to the substrate 11 so as to be visible from the rear of the bicycle, and its one end is connected to the midpoint between the switch 13 and the first LED 9, and the other end is connected to the second LED 10 through the fifth resistor _R5 and the third transistor _Tr3 . The first resistor R ₁ and the collector of the first transistor Tr ₁ are connected to each other. The base of the third transistor Tr ₃ is the sixth resistor connected in series to the solar cell 7.
It is connected to the connection midpoint of R ₆ and the seventh resistor R ₇ .

The resistance values r ₂ and r 3 of the second and third resistors R ₂ and _{R 3 are} such that when the solar cell 7 receives a predetermined value or more of, for example, 100 lux to 200 lux, the second transistor Tr ₂ is turned on;
The sixth,
The resistance values r ₆ , r ₇ of the seventh resistors R ₆ , R ₇ are such that the first transistor Tr ₁ turns on when the solar cell 7 receives light from, for example, a car headlight and senses light of several tens of lux.
It is set to turn on under the following conditions and turn off under several tens of lux. Furthermore, the resistance values r 1 _and r 5 of the first and fifth resistors R _{1 and R 5 are} set to satisfy r ₁ > r ₅ .

In the above configuration, the solar cell 7 also functions as a means for detecting sunlight and external light such as headlights of a car, and the first to fourth resistors R ₁ , R ₂ , R ₃ ,
R ₄ and the first and second transistors Tr ₁ and Tr ₂ constitute a lighting suppression circuit that detects the presence or absence of a predetermined amount of sunlight and prevents the diodes 9 and 10 from lighting during the daytime. The seventh resistors R ₅ , R ₆ , R ₇ and the third transistor Tr ₃ constitute a brightness increasing circuit that lights up the diode 10 when receiving external light at night, thereby achieving high-intensity lighting.

Next, the operation of the configuration of the above embodiment will be explained. Assume that the manual switch 13 is now closed. When exposed to daytime sunlight S, an electromotive force is generated in the solar cell 7, thereby charging the secondary battery 8. At this time, when the illuminance in the solar cell 7 exceeds a predetermined value, the second transistor Tr ₂ is turned on and the first transistor Tr ₁ is turned off, thereby preventing the LEDs 9 and 10 from lighting up. Therefore, turn on manual switch 13.
Even if you do so, power consumption due to unnecessary lighting can be prevented.

At night, the second transistor Tr ₂ is turned off,
The first transistor Tr 1 is inverted to ON, and the first transistor Tr ₁ is inverted to ON.
The charge from the battery 8 flows into the 1LED 9, which lights up. At this time, the current flowing through the LED 9 is limited by the first resistor _R1 , resulting in low brightness lighting, but there is no problem in visibility since the surroundings are dark.

Then, when a car runs from behind the bicycle and approaches the bicycle, the solar cell 8 receives the light from the headlight. At this time solar cell 8
The electromotive voltage is enough to turn off the second transistor Tr ₂ and turn on the third transistor Tr ₃ , and the voltage of the first LED 9 turns off.
continues to be lit, and the second LED 10 is newly lit. This second LED 10 has a large amount of current flowing through it because the resistance value of the fifth resistor _R5 is set to a small value, and is lit with high brightness to improve visibility despite the presence of the headlight beam.

Further, when the first and second LEDs 9 and 10 do not need to be lit, the switch 13 is turned off.

In the configuration of the above embodiment, since the solar cell 8 also serves as a means for detecting external light, a separate detecting means is not required, and the device can be made smaller and lower in cost.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can also be applied to direction indicators and headlights other than taillights. Alternatively, the solar cell 7 may be provided horizontally, and a means for detecting external light in a substantially horizontal direction may be provided separately. Alternatively, the solar cell 7 may be provided in a manner that it can be raised and lowered so that it is placed horizontally during the day to receive sunlight, and placed vertically during the night to receive external light. or,
In the above embodiment, the second LED 10 is provided for high-intensity lighting, but it may be configured such that only one LED is provided and the current amount of this LED is increased when receiving external light to cause high-intensity lighting.

Further, other lighting equipment such as a strobe may be used to obtain high-intensity lighting. Furthermore, the mounting position of the safety light is not limited to the rear of a bicycle, and can also be mounted on a vehicle such as a motorbike.

(F) Effects of the Invention According to the present invention configured as described above, the safety light turns on with high brightness when receiving substantially horizontal external light such as a headlight, so visibility is improved and safe driving is possible. Become. Furthermore, since the safety light is configured to turn on at high brightness only when necessary and increase current consumption, it has great effects such as making it possible to reduce the capacity and size of solar cells and secondary batteries.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional example, FIG. 2 is an enlarged view of essential parts of an embodiment of the present invention, and FIG. 3 is an electric circuit diagram of the same embodiment. 7... Solar cell, 8... Secondary battery, 9, 10... Light emitting diode (safety light).

Claims (1)

[Claims] 1. A solar cell, a secondary battery charged by the solar cell, a safety light lit by the secondary battery, a detection means for detecting external light, and this detection means A vehicular safety light device comprising: brightness increasing means for increasing the brightness of the safety light when the safety light detects illuminance above a predetermined level. 2. The vehicle safety light device according to claim 1, wherein the solar cell also serves as the detection means. 3. The safety light device for a vehicle according to claim 2, wherein the solar cell is mounted upward at a predetermined angle with respect to the ground.