Power supply and night vision device using the power supply

1. A night vision device comprising:

an optical system for forming a subject;

an image intensifier for converting and intensifying optical signals formed by the optical system into electrical signals, converting the electrical signals into optical signals, and outputting them;

a battery;

a switch including a power switch;

a booster for boosting a battery voltage provided by the battery to an established voltage according to an operation of the power switch, and outputting a boost voltage;

a voltage selector for comparing the voltage provided by the battery with a reference voltage, outputting the boost voltage when the battery voltage is below the reference voltage, and outputting the battery voltage when the battery voltage is beyond the reference voltage;

a supply controller operable according to a light sense signal, for providing the voltage output by the voltage selector to the image intensifier;

a high light sensor for comparing a surrounding brightness with an established brightness, and outputting a light sense signal according to a comparison result;

a coupling sensor for sensing coupling states between the night vision device and a mounting device, and outputting a corresponding coupling sense signal;

an infrared emitter; and

a battery voltage sensor;

wherein the supply controller comprises:

a first switching element, operable by the coupling sense signal, for forming a first transfer path of the boost voltage output by the booster;

a second switching element, operable by the coupling sense signal, for forming a second transfer path of the select voltage output by the voltage selector;

a third switching element, operable by the light sense signal, for transferring the boost voltage provided through the first transfer path to the infrared emitter or the battery voltage sensor; and

a fourth switching element operable by the light sense signal, for transferring the select voltage provided through the second transfer path to the image intensifier.

2. The night vision device of claim 1 , wherein the voltage selector comprises:

a voltage detector for comparing the battery voltage with the reference voltage, and outputting a first signal according to a comparison result;

a fifth switching element operable by the first signal, for forming a first output path for outputting the boost voltage provided by the booster; and

a sixth switching element operable according to an operation state of the fifth switching element, for forming a second output path for outputting the battery voltage.

3. The night vision device of claim 1 , wherein the supply controller terminates supply of power to the image intensifier when the high light sensor outputs a light sense signal indicating that the surrounding brightness is greater than the established brightness, and starts supply of power again when the surrounding brightness is lower than the established brightness.

4. The night vision device of claim 1 , wherein the switch further comprises an infrared operation switch, and

the infrared emitter comprises an infrared photodiode for emitting infrared rays according to the applied voltage when the infrared operation switch is operated.

5. The night vision device of claim 1 , further comprising:

a voltage detector for comparing the battery voltage with an established minimum driving voltage, and generating a second signal when the battery voltage is below the minimum driving voltage;

the battery voltage sensor including an emitter for emitting light according to the second signal, and warning that the battery voltage is below the minimum driving voltage.

6. The night vision device of claim 5 , wherein the high light sensor, the infrared emitter, and the light emitter of the battery voltage sensor are operated according to the voltage supplied by the booster, and the image intensifier is operated according to the voltage output by the voltage selector.

7. A night vision device comprising:

an optical system for forming a subject;

an image intensifier for converting and intensifying optical signals formed by the optical system into electrical signals, converting the electrical signals into optical signals, and outputting them;

a battery;

a switch including a power switch;

a booster for boosting a battery voltage provided by the battery to an established voltage according to an operation of the power switch, and outputting a boost voltage;

a voltage selector for comparing the voltage provided by the battery with a reference voltage, outputting the boost voltage when the battery voltage is below the reference voltage, and outputting the battery voltage when the battery voltage is beyond the reference voltage;

a supply controller operable according to a light sense signal, for providing the voltage output by the voltage selector to the image intensifier;

a high light sensor for comparing a surrounding brightness with an established brightness, and outputting a light sense signal according to a comparison result;

a coupling sensor for sensing coupling states between the night vision device and a mounting device, and outputting a corresponding coupling sense signal; and

a battery voltage sensor including an emitter for emitting light,

wherein the high light sensor, the infrared emitter, and the emitter of the battery voltage sensor are operated according to the voltage supplied by the booster, and

the image intensifier is operated according to the voltage output by the voltage selector.

8. The night vision device of claim 7 , wherein the supply controller comprises:

a first switching element operable by the coupling sense signal, for forming a first transfer path of the boost voltage output by the booster;

a second switching element operable by the coupling sense signal, for forming a second transfer path of the select voltage output by the voltage selector;

a third switching element operable by the light sense signal, for transferring the boost voltage provided through the first transfer path to the infrared emitter or the battery voltage sensor; and

a fourth switching element operable by the light sense signal, for transferring the select voltage provided through the second transfer path to the image intensifier.

9. The night vision device of claim 7 , wherein the voltage selector comprises:

a voltage detector for comparing the battery voltage with the reference voltage, and outputting a first signal according to a comparison result;

a first switching element operable by the first signal, for forming a first output path for outputting the boost voltage provided by the booster; and

a second switching element operable according to an operation state of the first switching element, for forming a second output path for outputting the battery voltage.

10. The night vision device of claim 7 , wherein the supply controller terminates supply of power to the image intensifier when the high light sensor outputs a light sense signal indicating that the surrounding brightness is greater than the established brightness, and starts supply of power again when the surrounding brightness is lower than the established brightness.

11. The night vision device of claim 7 , wherein the switch further comprises an infrared operation switch, and

the infrared emitter comprises an infrared photodiode for emitting infrared rays when the infrared operation switch is operated.

12. The night vision device of claim 7 , further comprising:

a voltage detector for comparing the battery voltage with an established minimum driving voltage, and generating a second signal when the battery voltage is below the minimum driving voltage;

wherein the battery voltage sensor warns that the battery voltage is below the minimum driving voltage.