JPH03170032A - Light indicator - Google Patents

Abstract

PURPOSE:To operate a light indicator stably to ambient light by making a light emitting element blink or illuminate continuously when a photodetection level is lowered to a 1st level or below and turning off the light emitting element when the level rises to a 2nd level or above. CONSTITUTION:When an ambient part is bright, a current voltage converting circuit 25 is in a high-level, a transistor(Tr) 27 turns on, and a Tr 28 turns off. The input level to the inverted input terminal of a comparator 35 is higher than that to the uninverted input terminal and a low-level output is generated; and a capacitor 41 is charged through a resistor 33, a Tr 22 is off, and a lamp 7 is turned off. When it becomes dark, the output level of the circuit 25 is lowered gradually and when the level is lowered below a set level, the Tr 27 turns off and the Tr 28 turns on; and the capacitor 41 is discharged through the Tr 28, so that the output of the comparator 35 rises to the high level. Thus, the Tr 22 turns on and the lamp 7 turns off. Consequently, the lamp 7 is blinked to stably indicate that it becomes dark.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a light indicator that detects and informs that the surroundings have become dark.

(Prior art) Conventionally, this type of light indicator uses a light sensor to detect external light, and when the surroundings become dark, the light detection level of the light sensor decreases, which affects the light sensor separately from the light sensor. This notification was provided by lighting a lamp installed in a position where no warning was to be given.

However, if the light sensor is placed in a position where light does not affect the light sensor, the light sensor and lamp must be installed quite far apart, making it difficult to install in a relatively narrow space, and also making it difficult to install both in a relatively narrow space. Wiring was troublesome as long wiring was required for connection.

Therefore, the inventors of the present invention have previously developed and filed an application for a light indicator that allows a light sensor and a light emitting element to be placed close to each other, making it easy to install and wire in a narrow space. (Special application 1986-1
(No. 48255) (Problem to be Solved by the Invention) By the way, when the light-emitting element and the optical sensor are brought close together in this way, the optical sensor receives light from the light-emitting element, so of course it is necessary to consider countermeasures against this. , it is required to perform stable operation against ambient light. However, the device of the earlier application was insufficient in terms of stable operation against ambient light.

SUMMARY OF THE INVENTION Therefore, the present invention seeks to provide a light indicator that is provided to optically couple a light emitting element and an optical sensor and is capable of stably operating the light emitting element against ambient light. .

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a light emitting element, and a light sensor that is provided to be optically coupled to the light emitting element and detects ambient light including light from the light emitting element. , the light detection level of this light sensor is the first
A control means is provided which causes the light-emitting element to start lighting when the level falls below the level, and turns off the light-emitting element when the level reaches a second level higher than the first level, and causes the light-emitting element to flash or continuously light when the light-emitting element is turned on. It is something that

(Function) In the present invention having such a configuration, the light sensor detects ambient light, and when the light detection level becomes equal to or lower than the first level, lighting of the light emitting element is started.

In this state, the light emitting element is blinked or lit continuously to notify that the surroundings have become dark.

Further, when the light detection level reaches the second level or higher, it is determined that the surroundings have become brighter, and the light emitting element is kept in the off state.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In this embodiment, the present invention will be described in which the present invention is applied to a tail lamp device of an automobile.

As shown in FIG. 5, a tail lamp 3 serving as an illumination lamp is connected to a battery 1 via a tail lamp switch 2 serving as an operation switch.

A human power terminal of a light indicator 4 is connected to both ends of the tail lamp switch 2.

As shown in FIGS. 2 and 3, the light indicator 4 is constructed by placing an optical sensor 6 and a lamp 7, which is a light emitting element, at a predetermined distance on a case 5 that houses a circuit board incorporating a control circuit, etc. They are arranged and fixed, and the optical sensor 6 and lamp 7 are surrounded by a cylindrical cap 8. The light-receiving surface 6a of the optical sensor 6 is provided on the opposite side from the lamp 7 side, so that the light from the lamp 7 is not directly incident thereon.

The case 5 is made black to improve the heat dissipation effect, and the cap 8 is made white to improve the heat reflectance.

On the upper part of the case 5, spring plate contacts 9 and 10 are provided facing each other so as to protrude outward from the lower end of the cap 8, and this light indicator is provided at a position offset by 90@ from each of the contacts 9 and 10. Locking pieces 11, 12 are provided which are used when attaching to other members. Then, the sizes of the locking pieces 11 and the locking pieces 12 are made different so that each of the contacts 9
．． 10 to the battery 1 side so that the polarity is correct.

In this way, the light indicator is configured as a socket type.

The control circuit housed in the case 5 has the configuration shown in FIG. That is, a series circuit of the lamp 7 and the first NPN transistor 22 is connected between the power terminals of 0>(1) via a diode 21, and a constant voltage diode is connected via the diode 21 and the resistor 23 in series. 24 are connected. Note that each of the power terminals (+) and (-) is connected to the contact 9.10.

The optical sensor 6 is made of, for example, a photodiode,
The current output from the optical sensor 6 is supplied to a current-to-voltage conversion circuit 25 consisting of an operational amplifier. The output terminal of the current-to-voltage conversion circuit 25 is connected via a resistor 26 to the base of a second transistor 27 of a Schmitt circuit 29 consisting of NPN type second and third transistors 27 and 28.

The Schmitt circuit 29 connects the collector of the second transistor 27 to the constant current diode 24 via a resistor 30.
and the base of the third transistor 28 via a resistor 31;
, the emitters of the third transistors 27 and 28 are connected to the resistor 32.
The collector of the third transistor 28 is connected to the anode terminal of the voltage regulator diode 24 through the resistor 3.
3 to the cathode terminal of the voltage regulator diode 24, and the base of the third transistor 28 is connected to the anode terminal of the voltage regulator diode 24 via a resistor 34.

Further, the collector of the third transistor 28 is connected to the inverting input terminal (1) of a comparator 35 consisting of an operational amplifier.

A series circuit of a resistor 36 and an NPN type fourth transistor 37 is connected in parallel to the series circuit of the resistor 30 and the second transistor 27 of the Schmitt circuit 29 and the series circuit of the resistor 33 and the third transistor 28. Connected.

A resistor 38 and three series voltage dividing circuits are also connected in parallel to the constant voltage diode 24, and the connection point of the resistors 38 and 39 is connected to the non-inverting input terminal (+) of the comparator 35. The output terminal of the comparator 35 and the non-inverting input terminal (
+) is connected with a resistor 40.

A capacitor 41 is connected in parallel to the series circuit of the third transistor 28 and the resistor 32. The resistor 33 and capacitor 41 constitute an integrating circuit.

A capacitor 43 is connected in parallel between the output terminals of the comparator 35 via a diode 42. The connection point between the diode 42 and the capacitor 43 is then connected to the fourth transistor via a resistor 44. It is connected to the base of transistor 37.

Further, the output terminal of the comparator 35 is connected to the base of the first transistor 22 via a resistor 45. Note that a resistor 46 is connected between the base and emitter of the first transistor 22.

The output terminal of the current-voltage conversion circuit 25 and the resistor 33
and the connection point with the capacitor 41.
The collector and emitter of the transistor 47 are connected.

The base of the fifth transistor 47 is a resistor 48.49.
are connected in series to the anode terminal of the voltage regulator diode 24. The connection point of the resistors 48 and 49 is connected to the cathode terminal of the constant voltage diode 24 via a capacitor 50.

In this embodiment having such a configuration, when the surroundings are bright, the output of the current-to-voltage conversion circuit 25 is at a high level, the second transistor 27 is on, and the third transistor 28 is off. Therefore, in the comparator 35, the human power level to the inverting input terminal (1) is higher than the human power level to the non-inverting input terminal (+), and the output of the comparator 35 is at a low level.At this time, Capacitor 41 is charged via resistor 33.

Therefore, the first transistor 22 is in an off state and the lamp 7 is in an extinguished state.

In this state, when the surroundings become dark, the output level of the current-to-voltage conversion circuit 25 gradually decreases as shown by the dotted line waveform in FIG. When the voltage drops below the first level, the second transistor 27 is turned off and the third transistor 28 is turned on. As a result, the capacitor 41 of the integrating circuit is discharged via the third transistor 28, and the output level of the integrating circuit, that is, the inverting input terminal of the comparator 35 (
When the human power level to (1) decreases and the output level of the integrating circuit becomes less than the human power level a1 to the non-inverting input terminal (+), the output of the comparator 35 is inverted and becomes high level.

In this way, the first transistor 22 is turned on and the lamp is lit. Also, the capacitor 4 is connected via the diode 42.
3 is charged and the fourth transistor 37 is turned on. Further, the output of the comparator 35 is fed back to the non-inverting input terminal (+) via the resistor 40, and the output of the comparator 35 is fed back to the non-inverting input terminal (+).
+)'s human power level increases from a1 to a2.

When the fourth transistor 37 is turned on, the resistor 36 is connected in parallel to the resistor 33, so the third transistor 2
The emitter potential of transistor 8 rises, and the collector potential of transistor 28 also rises. Thus, the capacitor 41 becomes charged via the resistor 33.

In this way, the output level of the capacitor 41 of the integrating circuit is the fourth
As shown by the solid line waveform in FIG.
2 or more, the L voltage of the comparator 35 is inverted to low level, and the first transistor 2'. is turned off and the lamp 7 is extinguished. Then, the input level 4a2 to the non-inverting input terminal (+) of the compensator 35 decreases to a.Furthermore, the fourth transistor 37 is also turned off due to the discharge of the capacitor 43.

In this way, the capacitor 41 of the integrating circuit is discharged via the =th transistor 28 again.

In this way, when the output level of the optical sensor 6, that is, the output level of the current-to-voltage conversion circuit 25 is below the negative level, the capacitor 41 of the integrating circuit is repeatedly discharged and charged, and the comparator 35 is When the human power level to the b-inverting input terminal (-) becomes equal to or lower than a1, the first transistor 22 is turned off and the lamp 7 goes out, and the human power level to the inverting input terminal (-) of the comparator 35 becomes lower than a1. When the voltage exceeds a2, the first transistor 22 is turned on and the lamp 7 is turned on. That is, the lamp 7 is blinked as shown in FIG. 4(b).

In this way, by blinking the lamp 7, it is possible to notify that the surroundings have become dark. Therefore, the driver is lamp 7
When the tail lamp switch 2 is turned on after seeing the flashing of the tail lamp 3, the tail lamp 3 is turned on. Further, by turning on the switch 2, the human power terminals (+) and (-) of the light indicator 4 are short-circuited, so that the operation of the light indicator 4 is stopped.

Further, when the surroundings become bright with the tail lamp switch 2 turned off, the output level of the current-to-voltage conversion circuit 25 increases as shown by the dotted line waveform in FIG. 4(a). When the output level exceeds the second level, the Schmitt circuit 29 is inverted, the second transistor 27 is turned on, and the third transistor 28 is turned off.

Therefore, from now on, the output level of the comparator 35 is maintained at a low level, and the first transistor 22 is maintained in an off state. In other words, the lamp 7 stops blinking and remains off.In this way, the light sensor 6
After the output level of the current-to-voltage conversion circuit 25 falls below the first level, the lamp 7 blinks to perform the notification operation until it reaches a second level higher than the first level. can. Therefore, even if the surroundings become slightly brighter after the output level of the current-to-voltage conversion circuit 25 drops below the first level due to darkness in the surroundings, this will not stop the blinking operation of the lamp 7 and stabilize the lamp 7. It can be operated as follows. This means that, for example, even if the light from a street lamp enters when the surroundings are dark, the blinking operation of the lamp 7 will not be stopped, and it is possible to reliably notify that it has become dark.

Note that when you insert the key to drive the car when the surroundings are bright, the battery 1 is connected and charging of the capacitor 41 is started, but the charge level of the capacitor 41 is higher than the non-inverting input terminal of the comparator 35. It takes some time for the input level to reach (+) or higher, and during this time the output level of the comparator 35 becomes high level, causing the problem that the lamp 7 lights up. Therefore, in the full-length embodiment, when the battery 1 is connected, a base current is supplied to the base of the fifth transistor 47 via the capacitor 50, so that the transistor 47 is turned on for a short time, and the capacitor 41 is instantly charged and the lamp is turned on. 7 is prevented from lighting up.

Next, other embodiments of the present invention will be described with reference to the drawings. It should be noted that the same parts as in the previous embodiment are given the same reference numerals and detailed explanations will be omitted.

As shown in FIG. 6, the output of the current-to-voltage conversion circuit 25 is supplied to the inverting input terminal (-) of a first comparator 61 consisting of an operational amplifier.

A series voltage divider circuit of resistor 62.63, a series voltage divider circuit of resistor 64.65, a series voltage divider circuit of resistor 66.67, and six capacitors are connected in parallel to the constant voltage diode 24 through the diode 68 in the opposite direction. Connected. The connection point between the resistors 62 and 63 is connected to the non-inverting input terminal (+) of the first comparator 61, and the connection point between the resistors 64 and 65 is connected to the inverting input terminal (+) of the second comparator 70. (-), and connect the connection point between the resistors 66 and 67 to the third comparator 71.
is connected to the non-inverting input terminal (+) of the third comparator 7, and the connection point between the diode 68 and the capacitor 69 is connected to the third comparator 7.
A resistor 72 is connected between the output terminal of the third comparator 71 and the non-inverting input terminal (+). The output terminal of the transistor 61 is connected to the collector of the sixth transistor 73 of NPN type, and the seventh transistor 7 of NPN type is connected to the collector of the sixth transistor 73 of NPN type.
It is connected to the emitter of 4. The emitter of the sixth transistor 73 is connected to the connection point between the diode 68 and the capacitor 69 via a resistor 75 and a diode 76 in series. A resistor 77 is connected in parallel to the series circuit of the sixth transistor 73 and resistor 75.

A connection point between the diode 68 and the capacitor 69 is connected to the collector of the seventh transistor 74 via a diode 78, and is further connected to a PNP via seven resistors.
It is connected to the base of an eighth transistor 80 of the type.

The base of the seventh transistor 74 is connected to the base of the eighth transistor 80 via a resistor 81.

The output terminal of the second comparator 70 is connected to the non-inverting input terminal (+) of the first comparator 61 through a resistor 82 and a diode 83 in series, and to the sixth transistor through a resistor 84. It is connected to the base of 73. A capacitor 8 is connected between the non-inverting input terminal (+) of the second comparator 70 and the anode terminal of the constant voltage diode 24.
5 is connected.

The output terminal of the third comparator 71 is connected to the base of the eighth transistor 80.

The eighth transistor 80 has its collector connected to the base of the first transistor 22 via a resistor 86 and also to the non-inverting input terminal (+) of the second comparator 70 via a resistor 87. .

A constant voltage diode 88 is connected between the cathode terminal of the constant voltage diode 24 and the emitter of the eighth transistor 80.

In this embodiment with such a configuration, when the surroundings are bright, the output level of the current-to-voltage conversion circuit 25 is high, so the output level of the first comparator 61 is low level. Further, the output level of the third comparator 71 is at a high level.

Therefore, the seventh transistor 74 is turned on, the eighth transistor 80 is turned off, the first transistor 22 is turned off, and the lamp 7 is turned off.

In this state, when the surroundings become dark and the output level of the current-to-voltage conversion circuit 25 decreases, the output level of the first comparator 61 is inverted and becomes a high level.

As a result, first, the six capacitors are charged via the resistor 77 and the diode 76 with a relatively large time constant. Also, the seventh transistor 74 is turned off.

The charge level of the capacitor 69 is determined by the third comparator 71.
When the human power level to the non-inverting input terminal (+>) of the third comparator 71 is inverted or higher, the output level of the third comparator 71 becomes low level.

Thus, the eighth transistor 80 is turned on, thereby turning on the first transistor 22 and lighting the lamp 7. In this way, the lamp 7 is turned on a while after the optical sensor 6 detects that the surroundings have become dark. Therefore, if the surroundings become bright during this time, the lamp 7 will not be lit. This can prevent inconveniences such as the lamp 7 accidentally turning on when, for example, the user crosses a dark place for a short time during the day.

Further, when the eighth transistor 80 is turned on, the capacitor 8
5 is charged through the resistor 87, and soon the second comparator 7
0 is inverted to make the output level high. Also the third
When the output level of comparator 71 becomes low level, capacitor 69 is discharged via diode 78 and resistor 79.

When the output level of the second comparator 70 becomes high level,
The seventh transistor 73 is turned on, and the resistor 75 is connected in parallel to the resistor 77, and the resistor 82 and diode 8 are connected in parallel.
This is equivalent to connecting 3 series circuits in parallel to the resistor 62, and the level of human power applied to the non-inverting input terminal (+) of the first comparator 61 increases.Thus, the time constant for charging the 6 capacitors becomes small. At the same time, the operation of the first comparator 61 is stabilized.

Capacitor 69 is charged via resistors 75 and 77, but the level gradually decreases because more of the charge is discharged via resistor 79 (711m). When the charge level of the six capacitors falls below the human input level to the non-inverting input terminal (+) of the third comparator 71, the third comparator 71 is inverted and the output level is set to high level.

When the output level of the third comparator 71 becomes high level, the eighth and first transistors 80.22 are turned off and the lamp 7
goes out. Further, although the capacitor 85 is discharged, since the discharge time constant is large, the output level of the second comparator 70 is maintained at a high level.

Furthermore, when the output level of the third comparator 71 becomes high level, the discharge of the six capacitors stops! Therefore, the six capacitors are charged at a relatively high speed through the series circuit of the resistor 75 and the sixth transistor 73 and the parallel circuit of the resistor 77, and the charge level increases.

The charge level of the six capacitors is determined by the third comparator 71.
When the human input level to the non-inverting input terminal (+) of the third comparator 71 is exceeded, the third comparator 71 is inverted and the output level becomes low level.

The eighth transistor 80 is then turned on, which turns on the first transistor 22 and the lamp 7 is turned on again.

Further, when the output level of the third comparator 71 becomes low level, the six capacitors are discharged through the diode 78 and the seven resistors, and the charge level decreases. When the charge level of the six capacitors falls below the input level to the non-inverting input terminal (+) of the third comparator 71, the third comparator 71 is inverted and the output level becomes high level.

When the output level of the third comparator 71 becomes high level, the eighth and first transistors 80.22 are turned off and the ramp 7
goes out.

Thereafter, by repeating the same operation, the lamp 7 blinks at a relatively short period to notify that the surroundings have become dark.

Also, when the surroundings become bright, the current-voltage conversion circuit 2
The output level of the first comparator 6 increases, and the output level of the first comparator 6 increases.
When the input level to the non-inverting input terminal (+> of Therefore, the output level of the third comparator 71 is fixed at a high level, the seventh transistor 74 is turned on, and the eighth and first transistors 22 are turned on. is held in an off state, and the lamp 7 is held in an extinguished state.

By the way, when it gets bright after dark, the first
The input level to the non-inverting input terminal (+) of g61 is higher than the level initially set only by resistor 62 and 63 by the output level of second comparator 70 input via resistor 82 and diode 83. The prices are also getting higher.

Therefore, even in the full length embodiment, even if the surrounding area becomes dark and the output level of the current-to-voltage conversion circuit 25 decreases and the lamp 7 starts blinking, even if the surrounding area becomes somewhat brighter, this will cause the lamp 7 to continue blinking. The lamp 7 can be stably operated without being stopped. In other words, the effects of the above-mentioned embodiments and procedures are combined.

[Effects of the Invention] As detailed above, according to the present invention, in a device provided to optically couple a light emitting element and an optical sensor, it is possible to operate the light emitting element stably with respect to ambient light. It is possible to provide a light indicator that can be used.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is a circuit diagram of a light indicator, FIG. 2 is a side view,
FIG. 3 is a plan view, FIG. 4 is a waveform diagram for explaining the circuit operation of FIG. 1, FIG. 5 is a circuit diagram of a tail lamp device, and FIG. 6 is a light showing another length embodiment of the present invention FIG. 3 is a circuit diagram of an indicator. 4...Light indicator, 6...Top sensor 7...Lamp (light emitting element), 22, 27, 28.37...Transistor, 35...
・Comparator, 41.43... Capacitor, 33, 38, 39.40... Resistor.

Claims (1)

[Claims] a light emitting element; a light sensor that is provided to be optically coupled to the light emitting element and detects ambient light including light from the light emitting element; A control means is provided that causes the light-emitting element to start lighting, turns off the light-emitting element when the light-emitting element reaches a second level higher than the first level, and causes the light-emitting element to flicker or continuously light when the light-emitting element is turned on. A light indicator featuring