Mobile terminal and display controlling method thereof

1. A mobile terminal, comprising:

a detachable e-paper kit including e-paper, a transparent type solar cell, and a member of the detachable e-paper kit, the e-paper arranged between the transparent type solar cell and the member of the detachable e-paper kit; and

an external case including:

a wireless communication unit;

a display unit;

a power source;

a first control unit configured to control the display unit to display first information using the power source and to control the wireless communication unit to receive at least one incoming call;

a second control unit configured to control the e-paper to display second information using the solar cell; and

an attaching mechanism configured to receive the detachable e-paper kit,

wherein, when the detachable e-paper kit is attached, the first control unit is configured to control the display unit to display an incoming call indication while the wireless communication unit receives an incoming call, and to control the e-paper to display another call indication if the display unit is deactivated, and

wherein the another call indication includes a number of incoming calls when the display unit is deactivated.

2. The mobile terminal of claim 1 , wherein the e-paper kit further includes at least one of a touchpad configured to receive an input of a touch action to the e-paper and a light emitting device configured to illuminate light to the e-paper.

3. The mobile terminal of claim 1 , wherein the solar cell includes:

a transparent light concentrating unit configured to concentrate received solar energy, and

a storage unit configured to convert the solar energy received by the light concentrating unit into electric energy and to store the electric energy.

4. The mobile terminal of claim 1 , wherein the first control unit is further configured to display a dynamic picture on the display unit and to operate in conjunction with the second control unit in the e-paper kit to display a static picture on the e-paper.

5. The mobile terminal of claim 1 , wherein the second control unit is further configured to display the second information on the e-paper independently from the first control unit of the mobile terminal.

6. The mobile terminal of claim 1 , further comprising:

an external case forming an exterior of the mobile terminal,

wherein the e-paper kit is further configured to be detachably attached to one portion of the external case and thereby be connected to the mobile terminal.

7. The mobile terminal of claim 6 , wherein the first control unit is further configured to display the first information on the display unit and the second control unit is further configured to display the second information on the e-paper based on one of 1) whether the mobile terminal is opened or closed, 2) whether or not the mobile terminal is connected to the external case, and 3) a type of loading the mobile terminal in the external case.

8. The mobile terminal of claim 1 , wherein the second control unit is further configured to control operations of the e-paper kit when the e-paper kit is folded or rolled-up.

9. The mobile terminal of claim 1 , wherein the second control unit is further configured to display status information of the solar cell on the e-paper.

10. The mobile terminal of claim 1 , wherein the second control unit is further configured to maintain displaying the second information on the e-paper kit when the mobile terminal has been abnormally terminated.

11. The mobile terminal of claim 10 , wherein the second control unit is further configured to display prescribed information extracted from a memory of the mobile terminal when the mobile terminal is normally terminated.

12. The mobile terminal of claim 1 , wherein the wireless communication unit is further configured to receive at least one incoming message,

wherein the first control unit is further configured to control the wireless communication unit to display a received message indication if an incoming message is received, and

wherein the received message indication includes a number of received messages.

13. The mobile terminal of claim 1 , wherein, if the external case is switched from a close state to an open state, the first control unit is further configured to automatically release a touch function locked state of the first display unit and to automatically set the touch function locked state of the e-paper, and

wherein, if the external case is switched from the open state to the close state, the first control unit is further configured to automatically set the touch function locked state of the first display unit and to automatically release the touch function locked state of the e-paper.

14. A method of controlling a mobile terminal, the method comprising:

supplying power to the mobile terminal using a power source;

controlling operations of the mobile terminal by a first control unit;

receiving an attaching signal of a detachable e-paper kit including e-paper, a transparent type solar cell, and a member of the e-paper kit, the e-paper arranged between the transparent type solar cell and the member of the e-paper kit;

controlling, by the first control unit, a display unit of the mobile terminal to display first information using the power source and to control a wireless communication unit to receive at least one incoming call;

controlling, by a second control unit, the detachable e-paper kit to display second information on the e-paper using the solar cell; and

controlling, by the first control unit, the power source to apply the power to the detachable e-paper kit when a power applied by the solar cell is below a predetermined threshold,

wherein, when the detachable e-paper kit is attached, the first control unit is configured to control the display unit to display an incoming call indication while the wireless communication unit receives an incoming call, and to control the e-paper to display another call indication if the display unit is deactivated,

wherein the another call indication includes a number of incoming calls when the display unit is deactivated, and

wherein the display unit, the power source, the first control unit, the second control unit, and the wireless communication unit are included in an external case.

15. The method of claim 14 , wherein the solar cell includes:

a transparent light concentrating unit configured to concentrate received solar energy, and a storage unit configured to convert the solar energy received by the light concentrating unit into electric energy and to store the electric energy.

16. The method of claim 14 , further comprising:

displaying, by the first control unit, a dynamic picture on the display unit; and

displaying, by the first control unit operating in conjunction with the second control unit in the e-paper kit, a static picture on the e-paper.

17. The method of claim 14 , further comprising:

displaying, by the second control unit, the second information on the e-paper independently from the first control unit of the mobile terminal.

18. The method of claim 14 , further comprising:

displaying, by the first control unit, the first information on the display unit and displaying, by the second control unit, the second information on the e-paper based on one of 1) whether the mobile terminal is opened or closed, 2) whether or not the mobile terminal is connected to the external case, and 3) a type of loading the mobile terminal in the external case.

19. The method of claim 14 , further comprising:

controlling, by the second control unit, operations of the e-paper kit when the e-paper kit is folded or a rolled-up.

20. The method of claim 14 , further comprising:

maintaining, by the second control unit, the displaying of the second information on the e-paper kit when the mobile terminal has been abnormally terminated.