Image forming apparatus

1. An image forming apparatus comprising:

a body provided with an opening;

a transfer device movably mounted at the body so as to be removable through the opening; and

at least one locking lever rotatably installed at the transfer device, to rotate between a first position at which the at least one locking lever prevents the movement of the transfer device and a second position at which the at least one locking lever allows the movement of the transfer device,

wherein the at least one locking lever is disposed at the second position if the transfer device is mounted on the body to perform a transfer operation, and rotates to the first position to prevent the movement of the transfer device when the transfer device is being removed from the body.

2. The image forming apparatus of claim 1 , wherein one end of the at least one locking lever protrudes from the transfer device at the first position and is accommodated within the transfer device at the second position.

3. The image forming apparatus of claim 2 , wherein the body comprises a locking protrusion that is locked with another end of the at least one locking lever when the at least one locking lever is at the first position.

4. The image forming apparatus of claim 3 , further comprising a lever spring configured to elastically support the at least one locking lever such that the at least one locking lever is biased into the first position.

5. The image forming apparatus of claim 3 , further comprising:

one pair of guide members configured to guide movement of the transfer device while being disposed at opposite sides of inside the body, respectively,

wherein the one pair of guide members includes the locking protrusion and a rail part on which the transfer device is movably mounted.

6. The image forming apparatus of claim 3 , wherein the transfer device comprises an intermediate transfer belt on which toner is transferred, a driving roller and a driven roller to rotate the intermediate transfer belt, and one pair of transfer device frames which are spaced apart from each other and to which an end of each of the diving roller and the driven roller are rotatably installed, respectively, and

the at least one locking lever includes one pair of locking levers rotatably installed at the one pair of transfer device frames, respectively.

7. The image forming apparatus of claim 6 , wherein one end of the at least one locking lever is provided with a button part protruding from the transfer device, and another end of the at least one locking lever is provided with a locking part locked with the locking protrusion, and between the one and another ends there is provided a hinge part such that the at least one locking lever is rotatably installed at the one pair of transfer device frames, respectively.

8. The image forming apparatus of claim 7 , further comprising one pair of guide members, each of which includes a depression part provided in parallel to the locking protrusion such that the locking part is moved downward.

9. The image forming apparatus of claim 7 , wherein the one pair of transfer device frames comprises an accommodation part in which the at least one locking lever is accommodated, and a first through-hole to allow the button part to pass therethrough.

10. The image forming apparatus of claim 9 , wherein the transfer device further comprises a cover for the accommodation part,

wherein the cover includes a second through-hole allowing the locking part to pass therethrough.

11. An image forming apparatus comprising:

a body having an opening;

a cover to open and close the opening;

a plurality of developing units configured to develop an electrostatic latent image to a visible image through toner;

a transfer device movably mounted at the body so as to be removable through the opening; and

a sensing unit disposed to check toner transferred to the transfer device,

wherein the transfer device is removed through the opening while being movably mounted at an inside the body, and

the sensing unit rotates while interacting with movement of the transfer device.

12. The image forming apparatus of claim 11 , wherein the transfer device comprises an intermediate transfer belt on which visible images are transferred from the plurality of developing units, and

the sensing unit checks toner on the intermediate transfer belt.

13. The image forming apparatus of claim 12 , further comprising a cam member that is rotatably installed at one side of the sensing unit to allow the sensing unit to rotate according to movement of the transfer device.

14. The image forming apparatus of claim 13 , wherein the transfer device comprises a driving roller and a driven roller to rotate the intermediate transfer belt, and one pair of transfer device frames to which an end of each of the diving roller and the driven roller are rotatably installed, respectively, and

the transfer device includes a protrusion part protruding downward to interact with the cam member.

15. The image forming apparatus of claim 14 , wherein the cam member comprises a cam part formed to be locked with the protrusion part according to the movement of the transfer device.

16. The image forming apparatus of claim 13 , wherein the sensing unit comprises first hinge shafts formed at both side ends thereof, respectively, such that the sensing unit is rotatably installed at the body, and a second hinge shaft spaced apart from one of the first hinge shafts in parallel to the one of the first hinge shafts such that the cam member is rotatably installed at the second hinge shaft, and

the cam member comprises a hinge hole allowing the second hinge shaft to pass therethrough for installation.

17. The image forming apparatus of claim 11 , wherein the body comprises a body frame on which the sensing unit is rotatably installed, and

the image forming apparatus further comprises a sensor spring configured to elastically support the sensing unit such that one side of the sensing unit is biased in a state of being supported by the body frame.

18. An image forming apparatus comprising:

a body having an opening;

a cover to open and close the opening;

a plurality of developing units configured to develop an electrostatic latent image to a visible image through toner;

a transfer device movably mounted at the body so as to be insertable and removable relative to the opening;

a frame disposed within the body to guide the movement of the transfer device as it is removed from or inserted into the body;

a locking lever disposed on the transfer device that interacts with the frame to lock the transfer device into a position within the body;

a sensing unit that rotates in a direction of the movement of the transfer device as it is being removed from or inserted into the body,

wherein the locking lever rotates to lock the transfer device when the transfer device is being removed from the body.

19. An image forming apparatus of claim 18 , wherein the locking lever rotates between a first position at which one end of the locking lever protrudes from the transfer device and a second position at which the one end is accommodated within the transfer device, and

the frame comprises a locking protrusion that is locked with another end of the locking lever when the locking lever is at the first position.

20. An image forming apparatus of claim 19 , wherein the frame further comprises:

one pair of guide members configured to guide movement of the transfer device while being disposed at opposite sides of inside the body, respectively,

wherein the one pair of guide members includes the looking protrusion and a rail part on which the transfer device is movably mounted.

21. The image forming apparatus of claim 18 , further comprising a cam member that is rotatably installed at one side of the sensing unit to allow the sensing unit to rotate according to movement of the transfer device.

22. The image forming apparatus of claim 21 , wherein the sensing unit comprises first hinge shafts formed at both side ends thereof, respectively, such that the sensing unit is rotatably installed at the body, and a second hinge shaft spaced apart from one of the first hinge shafts in parallel to the one of the first hinge shafts such that the cam member is rotatably installed at the second hinge shaft, and

the cam member comprises a hinge hole allowing the second hinge shaft to pass therethrough.