Photographing apparatus for recognizing type of external device, method of controlling the photographing apparatus, and the external device

1. A photographing apparatus comprising:

a single conductor comprising a first terminal that is electrically connected to an external device;

a first resistor that is electrically connected to the first terminal via a first node; and

an external device recognizing unit that recognizes a type of the external device according to a voltage level of the first node; and

a trigger signal generating unit that outputs a trigger signal triggering light emission of a speed light via the first terminal when the external device is the speed light,

wherein:

a voltage level of the first node is determined according to voltage distributions of the first resistor and a second resistor included in the external device, and

both a presence of the external device is detected and the type of the external device is recognized using only the single conductor.

2. The photographing apparatus of claim 1 , further comprising a power supply unit that applies a first voltage to an end other than the first node of the first resistor when the external device is connected to the conductor, and stops applying the first voltage when the type of the external device is completely recognized.

3. The photographing apparatus of claim 1 , wherein the external device recognizing unit recognizes the type of the external device by using a lookup table including data about the voltage level of the first node according to the type of the external device.

4. The photographing apparatus of claim 1 , wherein a first electrode transmits an analog signal.

5. The photographing apparatus of claim 1 , further comprising an external device detecting unit that detects whether the external device is connected to the photographing apparatus by using power supplied from the external device.

6. The photographing apparatus of claim 5 , further comprising:

a power supply unit that applies the first voltage to the other end of the first resistor when the external device is connected to the conductor, and stops applying the first voltage when the type of the external device is completely recognized,

wherein the external device detecting unit detects whether the external device is connected to the photographing apparatus after the applying of the first voltage is stopped.

7. The photographing apparatus of claim 5 , further comprising:

a transistor comprising:

a gate terminal connected to the first terminal;

a first terminal connected to a second node; and

a grounded second terminal,

wherein:

the second node is coupled to a first power source,

when the external device is connected to the photographing apparatus, power is supplied from the external device via the first terminal, and

the external device detecting unit detects whether the external device is connected or not based on a voltage level of the second node as the transistor is electrically conductive due to the power supplied from the external device.

8. The photographing apparatus of claim 1 , further comprising a Zener diode connected to the first terminal.

9. An external device connected to a photographing apparatus, the external device comprising:

a second resistor having a resistance value determined according to a type of the external device, connected to the photographing apparatus via a single conductor comprising a first terminal of a single conductor of the photographing apparatus, and electrically connected to a first resistor included in the photographing apparatus, and

a trigger signal generating unit that outputs a trigger signal triggering light emission of a speed light via the first terminal when the external device is the speed light,

wherein a presence of the external device is detected and the type of the external device is recognized using only the single conductor.

10. The external device of claim 9 , wherein when the external device is connected to the photographing apparatus, the external device operates using power supplied from the photographing apparatus.

11. The external device of claim 9 , wherein the external device supplies a detection voltage, to the first terminal of the photographing apparatus by using the power supplied from the photographing apparatus.

12. A method of recognizing an external device by a photographing apparatus that recognizes a type of the external device when the external device is connected to the photographing apparatus, wherein the photographing apparatus comprises:

a single conductor comprising a first terminal and a first resistor electrically connected to the first terminal via a first node, and

the external device is connected to the photographing apparatus via the first terminal and comprises a second resistor that is electrically connected to the first resistor when the external device is connected to the photographing apparatus,

wherein the method comprises:

applying a first voltage to an end other than the first node of the first resistor;

measuring a voltage level of the first node; and

recognizing the type of the external device according to a voltage level of the first node; and

outputting a trigger signal triggering light emission of a speed light via the first terminal if the external device is the speed light,

wherein a presence of the external device is detected and the type of the external device is recognized using only the single conductor.

13. The method of claim 12 , further comprising, when the type of the external device is completely recognized, stopping application of the first voltage.

14. The method of claim 12 , wherein the type of the external device is recognized using a lookup table including data about the voltage level of the first node according to the type of the external device.

15. The method of claim 12 , further comprising detecting whether the external device is connected to the photographing apparatus by using power supplied from the external device.

16. The method of claim 15 , further comprising:

stopping application of the first voltage when the type of the external device is completely recognized,

wherein whether the external device is connected is detected after the applying of the first voltage is stopped.

17. The method of claim 12 , wherein the second resistor of the external device has a resistance value determined according to the type of the external device.

18. The method of claim 12 , wherein the external device operates using the power supplied from the photographing apparatus.