Patent ID: 7428066

Claim:
A testing apparatus for verifying an operation of a controller unit which forms output image data, outputs a command signal to an engine unit, and serves as an image output apparatus in cooperation with the engine unit for outputting the formed output image data onto a medium, by emulating the engine unit, comprising: interface means, provided on an extension bus unit of a general-purpose computer, for connecting to a video interface of the controller unit, and for making data communication with the controller unit; obtaining means for obtaining the command signal outputted by the controller unit via said interface means; a timer for providing a notification of an elapse of a predetermined time indicating a pseudo-engine timing as a virtual engine unit; setting means for setting a state of the virtual engine unit as a state of the engine unit in accordance with the notification of the elapsed time by said timer and the obtained command signal; transmitting means for transmitting a response signal via said interface means in accordance with the state of the virtual engine unit and the obtained command signal; and generating means for generating a pseudo-image sync signal as the virtual engine unit to the controller unit in accordance with the state of the virtual engine unit, wherein said testing apparatus is connected to the controller unit as the virtual engine unit in place of the engine unit, when verification of the operation of the controller unit is executed.