Patent ID: 7010238

Claim:
An image printing apparatus comprising: a photosensitive medium; a light scanning unit including a light source to emit a light beam onto the photosensitive medium; a developing portion to develop an electrostatic latent image formed on the photosensitive medium by the light scanning unit with a developer; a transfer roller to transfer the image developed on the photosensitive medium with the developer to a fed paper; a printing engine state diagnosing portion to detect an effective resistance value of the photosensitive medium and the transfer roller; a controller to determine a transfer voltage to be supplied to the transfer roller to print according to the effective resistance value in a printing engine driving condition determining mode, and to determine a driving voltage for a printing mode with respect to the light source of the light scanning unit based on the determined transfer voltage; and a light source drive unit to drive the light source according to the driving voltage in the printing mode under the control of the controller.