HP 8550 Service Manual - Page 189

Table 57. Sequence functions Item INTR (initial rotation) DSRDY (scanning preparation) COPY (copy) LSTR (last rotation) Period Purpose Remarks From when a key input is made or an original is set until COPY START is pressed. To rotate the laser scanner motor, thereby stabilizing the sensitivity of the photosensitive drum. From when COPY START key is pressed until the point of rotation of the intermediate transfer drum reaches the leading edge of the first color. From when control rotation ends until all toner has been transferred to the copy paper. To turn on and off the laser beam using video signals so as to form an image on the photosensitive drum; thereafter, to turn the toner image into a visible image and transfer the result to copy paper. From when COPY ends until the main motor stops. To discharge copy paper and to clean the intermediate transfer drum. The intermediate transfer drum is cleaned for each copy. In the case of continuous copying, cleaning is also executed during COPY. EN Copy module 187