Image forming apparatus with rotary element opposite an image reading unit

Abstract

An image forming apparatus includes a sheet transport path that transports a sheet on which an image has been recorded, the sheet transport path including a first guide surface and a second guide surface opposed to the first guide surface, an image reading unit disposed on the same side as the first guide surface of the sheet transport path to read the image, and a rotary element disposed on the same side as the second guide surface, the rotary element being rotatably disposed with a gap between the rotary element and the first guide surface.

What is claimed is: 
     
       1. An image forming apparatus comprising:
 a sheet transport path configured to transport a sheet on which an image has been recorded, the sheet transport path including a first guide surface and a second guide surface opposed to the first guide surface; 
 an image reading unit disposed on a same side as the first guide surface of the sheet transport path and configured to read the image, the image reading unit includes a light-emitting part to emit light; and 
 a cylindrical rotary element disposed on a same side as the second guide surface, the cylindrical rotary element being rotatably disposed with a an air gap between the cylindrical rotary element and the first guide surface, along a full length of the cylindrical rotary element, when the image reading unit reads the image, 
 wherein the first guide surface includes a light passing part configured to allow light emitted from the light-emitting part pass through, 
 wherein the cylindrical rotary element is disposed overlapping the light passing part in a direction of transport of the sheet in the sheet transport path, and 
 wherein the cylindrical rotary element is disposed in an area opposite to the image reading unit in a direction perpendicular to a surface of the transported sheet. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein the cylindrical rotary element is disposed in an area opposite to the image reading unit, and disposed in an area that is not opposite to the image reading unit in a direction that crosses a direction of transport of the sheet. 
     
     
       3. The image forming apparatus according to  claim 2 , further comprising a detector that detects a test image formed on the sheet being transported,
 wherein the cylindrical rotary element is disposed opposite to an area in which the test image is detected by the detector. 
 
     
     
       4. The image forming apparatus according to  claim 1 , further comprising a detector that detects a test image formed on the sheet being transported,
 wherein the cylindrical rotary element is disposed opposite to an area in which the test image is detected by the detector. 
 
     
     
       5. The image forming apparatus according to claim  4  3, wherein the test image includes a predetermined trigger image, and the cylindrical rotary element has a surface color that is selected in accordance with the predetermined trigger image. 
     
     
       6. The image forming apparatus according to  claim 1 , wherein the cylindrical rotary element is removably disposed on the second guide surface. 
     
     
       7. The image forming apparatus according to  claim 1 , further comprising a cooling unit that cools the sheet, the cooling unit being disposed upstream of the image reading unit in a direction of transport of the sheet in the sheet transport path. 
     
     
       8. The image forming apparatus according to  claim 7 ,
 wherein the cooling unit includes 
 a heat dissipation element that contacts one side of the sheet being transported, 
 an endless belt that circulates with the sheet sandwiched between the endless belt and the heat dissipation element to transport the sheet, and 
 an air blower that blows air onto the heat dissipation element and the endless belt. 
 
     
     
       9. The image forming apparatus according to  claim 1 , further comprising a bending unit that bends the sheet, the bending unit being disposed downstream of the image reading unit in a direction of transport of the sheet in the sheet transport path. 
     
     
       10. The image forming apparatus according to  claim 1 , further comprising a bending unit that bends the sheet, the bending unit being disposed upstream of the image reading unit and downstream of a cooling unit in a direction of transport of the sheet in the sheet transport path. 
     
     
       11. The image forming apparatus according to  claim 1 , wherein the cylindrical rotary element includes a plurality of cylindrical rotating elements each separated by a gap along a rotating axis of the cylindrical rotary element. 
     
     
       12. The image forming apparatus according to  claim 11 , wherein the second guide surface includes a plurality of openings, each of the cylindrical rotating elements projecting through a corresponding one of the openings. 
     
     
       13. The image forming apparatus according to  claim 11 , further comprising a photosensor configured to read a pattern on the sheet, the photosensor aligned with one of the cylindrical rotating elements and the image reading unit aligned with a different one of the cylindrical rotating elements. 
     
     
       14. The image forming apparatus according to claim 1, wherein the cylindrical rotary element is fixed with respect to the first guide surface to maintain the gap. 
     
     
       15. The image forming apparatus according to claim 1, wherein the second guide surface approaches the first guide surface along the sheet transport path in the transport direction. 
     
     
       16. The image forming apparatus according to claim 1, wherein the first guide surface extends along the sheet transport path.