Patent ID: 6073928
Filing Date: 2000-06-13
Classification: B65H

Abstract:
A sheet end detecting mechanism for use in a printing device for detecting an end of a recording sheet and for controlling the conveyance of the recording sheet and a subsequent recording sheet as the recording sheets are moved through the printing device by rollers, said mechanism comprising:optical detecting means for detecting an end of a first type of recording sheet and for controlling the conveyance in a sheet conveyance direction of a subsequent first type of recording sheet, said optical detecting means detecting a reflected light from a surface of the first type of recording sheet and which is disposed at a slightly upper-path-side of a printing position in the printing device in the sheet conveyance direction;a first mechanical detecting means for detecting an end of a second type of recording sheet and for controlling conveyance in the sheet conveyance direction of a subsequent second type of recording sheet when said optical detecting means does not detect the first type of recording sheet, said first mechanical detecting means being displaced by passing of the second type of recording sheet therethrough and being disposed on the upper-path-side of said optical detecting means; anda second mechanical detecting means for detecting an end of the second type of recording sheet moved in a direction opposite of the sheet conveyance direction and for controlling conveyance in the opposite direction of a subsequent second type of recording sheet when said optical detecting means does not detect the first type of recording sheet, said second mechanical detecting means being displaced by passing of the second type of recording sheet therethrough and being disposed on a lower-path-side of said optical detecting means.