Image reading apparatus

1. An image reading apparatus, comprising:

a shooter where a first mounting surface that is inclined with respect to a horizontal plane is formed thereon;

a stacker where a second mounting surface is formed thereon;

a supporting unit that movably supports the stacker in such a manner that the stacker is arranged in a first region or a second region;

a conveyance unit that conveys a document that is mounted on the first mounting surface from the shooter to the stacker in such a manner that a back surface for a surface of the document that faces the first mounting surface faces the second mounting surface after conveyance thereof when the stacker is arranged in the first region, and thereby, mounts the document on the second mounting surface; and

a reading unit that reads an image from the document when the document is conveyed by the conveyance unit, wherein

a surface area of a region of the first mounting surface that is covered by the stacker when the stacker is arranged in the first region is greater than a surface area of a region of the first mounting surface that is covered by the stacker when the stacker is arranged in the second region, and

the stacker is formed to be capable of being lengthened or shortened in such a manner that the stacker is lengthened when the stacker is in the first region and the stacker is shortened when the stacker is in the second region.

2. The image reading apparatus according to claim 1 , wherein the supporting unit rotatably supports the stacker in such a manner that the stacker is arranged in the first region or the second region.

3. The image reading apparatus according to claim 2 , wherein the second region is closer to the shooter than the first region.

4. The image reading apparatus according to claim 3 , further comprising

an actuator that moves the stacker in such a manner that the stacker is arranged in the first region or the second region.

5. The image reading apparatus according to claim 4 , wherein:

the actuator has:

a motor that normally rotates or reversely rotates; and

an interlocking mechanism that moves the stacker in such a manner that the stacker is arranged in the first region when the motor normally rotates, and moves the stacker in such a manner that the stacker is arranged in the second region when the motor reversely rotates, wherein

the conveyance unit conveys the document from the shooter to the stacker when the motor normally rotates.

6. The image reading apparatus according to claim 4 , further comprising:

an extension actuator that lengthens or shortens the stacker; and

a controller configured to control the extension actuator in such a manner that the stacker is lengthened when the stacker is arranged in the first region and the stacker is shortened when the stacker is arranged in the second region.

7. The image reading apparatus according to claim 6 , wherein the controller controls the actuator in such a manner that the stacker moves to the first region when reading of the document by the reading unit is started.

8. The image reading apparatus according to claim 6 , wherein the controller controls the actuator and the extension actuator in such a manner that the stacker is shortened while the stacker moves from the first region to the second region.

9. The image reading apparatus according to claim 8 , further comprising

a sensor that detects whether the document is mounted on the first mounting surface, wherein

the controller controls the actuator in such a manner that the stacker is arranged in the second region when it is detected that the document is not mounted on the first mounting surface.

10. The image reading apparatus according to claim 1 , wherein the shooter is movably supported in such a manner that an upper end of the shooter moves down when the stacker is arranged in the second region.