Printing apparatus with automatically interchangeable ribbon cartridges

Claim 1

A printing apparatus which is loaded with a transfer member including a color agent to be transferred to a sheet and transfers the color agent to the sheet in accordance with a pattern, thereby forming an image on the sheet, comprising: a housing including means for transferring the color agent to the sheet and a sheet cassette mounting portion capable of being fitted with a sheet cassette for supplying sheets to which the color agent is to be transferred by the transfer member, said cassette mounting portion having a detection mechanism for detecting the type of the sheets contained in the sheet cassette and delivering a detection signal; mounting means in the housing for mounting the transfer member; means for holding a plurality of spare transfer members for replacement, said holding means including shifting means for automatically replacing the transfer member set in the mounting means with one of the spare transfer members, said shifting means including a positioning mechanism for supporting the transfer members held in the holding means and locating a specified one of the transfer members in a position corresponding to the mounting means in the housing, and a shifting mechanism for moving the transfer member from the set position to the mounting means so that the transfer member is set in the mounting means; detecting means for detecting the type of each of the transfer members set in the holding means and delivering a detection signal; and a control mechanism provided in said housing, said control mechanism being coupled to said detection mechanism, said detecting means and said positioning mechanism and being adapted to control the positioning mechanism so that the transfer member corresponding to the type of the sheets detected by the detection mechanism is automatically set in the position corresponding to the mounting means in the housing.