Patent ID: 8864276

Claim:
A printhead comprising a plurality of element substrates, each having a plurality of printing elements and a driving circuit for driving the plurality of printing elements, each of the plurality of element substrates comprising: an error detection circuit, connected to a first terminal for inputting print data from outside and to a second terminal for inputting a clock signal from outside, configured to detect whether or not a transfer error has occurred in a print data signal corresponding to printing elements of one element substrate input to the first terminal; and an error output circuit configured to receive a detection result from the error detection circuit, and output the result of detection to outside, wherein a plurality of error output circuits included in the plurality of element substrates are cascade-connected via a third terminal different from the first and second terminals, and wherein the error output circuit on an n-th stage, other than the error output circuits on a first stage and a final stage of the plurality of cascade-connected error output circuits, is further configured to output information, based on a detection result received from the error output circuit on an (n−1)-th stage and a detection result from the error detection circuit on the n-th stage, to the error output circuit on an (n+1)-th stage.