Power unit and image forming apparatus provided with same mounted thereto

1. An image forming system for forming an image on a recording material, comprising:

an image forming apparatus for forming an image on a recording material;

a first option device mountable to said image forming apparatus;

an electrical substrate, mounted on said image forming apparatus, for supplying electric power to said first option device;

a second option device mountable to said image forming apparatus; and

an electric power source substrate for supplying electric power to said second option device, said electric power source substrate being mounted to said image forming apparatus when said second option device is mounted to said image forming apparatus and being not mounted to said image forming apparatus when said second option device is not mounted to said image forming apparatus.

2. A system according to claim 1 , wherein said electric power source substrate is capable of supplying electric power to a third option device mountable to said image forming apparatus.

3. A system according to claim 1 , wherein said electric power source substrate is provided with a connector for electrically connecting with one of said first and second option devices to supply the electric power to said one of said first and second option devices.

4. A system according to claim 1 , wherein said electric power source substrate comprises a plurality of connectors, which include a connector electrically connectable with at least one of said first and second option devices.

5. A system according to claim 1 , wherein said image forming apparatus comprises a voltage source board for supplying electric power to image forming means in addition to said electrical substrate for supplying electric power to said first option device.

6. A system according to claim 1 , wherein said first option device is an original reading apparatus for reading an original.

7. A system according to claim 1 , wherein said second option device is a recording material accommodating portion for accommodating recording material to be supplied to image forming means.

8. An image forming apparatus for forming an image on a recording material, said apparatus comprising:

a main assembly comprising an image forming portion;

one or more option devices mountable to said main assembly;

a power unit for supplying electric power to said one or more option devices, said power unit being mounted to said main assembly when said one or more option devices are mounted to said main assembly and being not mounted to said main assembly when said one or more option devices are not mounted to said main assembly; and

a connector for electrically connecting with said one or more option devices, said connector being mounted on said power unit.

9. An apparatus according to claim 8 , further comprising a voltage source board, wherein electric power supply to an option device which is different from said one or more option devices is effected by said voltage source board.

10. An apparatus according to claim 9 , further comprising a second voltage source board, different from said voltage source board, for supplying electric power to the image forming portion.

11. An apparatus according to claim 9 , wherein said option device to which the electric power is supplied from said voltage source board comprises an original reading apparatus for reading an original.

12. An apparatus according to claim 9 , wherein said option device to which the electric power is supplied from said voltage source board comprises a recording material accommodating portion for accommodating a recording material to be supplied to the image forming portion.

13. An apparatus according to claim 8 , wherein electric power supply to an option device which is different from said one or more option devices is effected by a second power unit detachably mountable to said image forming apparatus.

14. An apparatus according to claim 8 , wherein said power unit includes a plurality of connectors for respective option devices.