Image forming apparatus

1. An image forming apparatus, comprising:

an upper cover;

an image forming unit comprising:

an image carrier; and

a developing device to develop an electrostatic latent image formed on the image carrier with developer;

a toner container detachably connectable to the developing device to supply toner to the developing device through an opening in the toner container;

a shutter provided to the toner container and biased by a first elastic member in a direction to close the opening of the toner container with an elastic force;

a link member integrated with the shutter;

a shutter switching member to switch a position of the shutter to an open position against the elastic force of the first elastic member by applying an elastic force of a second elastic member to the link member and moving the link member to a pressing position; and

an interlock mechanism to retract the shutter switching member from the pressing position against the elastic force of the second elastic member in conjunction with opening of the upper cover of the image forming apparatus,

the opening being closed with the shutter receiving the elastic force of the first elastic member by switching the shutter switching member to a retracted position in conjunction with the opening of the upper cover.

2. The image forming apparatus according to claim 1 , further comprising:

a latch mechanism to hold the shutter switching member at the retracted position upon closing of the opening of the toner container with the shutter;

a release mechanism to release the latch mechanism upon power supply to the release mechanism; and

a detector to detect presence or absence of the image forming unit,

wherein the release mechanism releases the latch mechanism upon detection of presence of the image forming unit by the detector after the upper cover is closed to switch the shutter to the open position by moving the shutter switching member to the pressing position by the elastic force of the second elastic member.

3. The image forming apparatus according to claim 2 , further comprising a motor that provides a drive force by which the release mechanism releases the latch mechanism.

4. The image forming apparatus according to claim 2 , wherein the release mechanism is a solenoid.

5. The image forming apparatus according to claim 4 , wherein the solenoid comprises an elastic body.

6. The image forming apparatus according to claim 5 , wherein the elastic body is a spring.

7. The image forming apparatus according to claim 5 , wherein the elastic body is a foam body.

8. The image forming apparatus according to claim 5 , wherein the elastic body is an air damper.

9. The image forming apparatus according to claim 5 , wherein the elastic body is an oil damper.

10. The image forming apparatus according to claim 1 , further comprising:

an image forming part employing a tandem-type intermediate transfer system, the image forming part comprising a transfer unit to primarily transfer the toner image formed on the image carrier onto an intermediate transfer body disposed opposite the image carrier and secondarily transfer the toner image from the intermediate transfer body onto a recording medium; and

multiple image forming units each constructed of the image carrier and the developing device and disposed opposite the intermediate transfer body along a direction of rotation of the intermediate transfer body.

11. The image forming apparatus according to claim 1 , wherein the interlock mechanism is a wire.

12. The image forming apparatus according to claim 1 , wherein the interlock mechanism is constructed of a rack and a gear.

13. The image forming apparatus according to claim 1 , wherein the second elastic member is a spring.

14. The image forming apparatus according to claim 1 , wherein the second elastic member is made of rubber.