Image reading apparatus having detachable optical system

A detachable two-part component image recording apparatus comprising:

• a first image processing unit consisting of a first housing member, a light source, a rod lens, a first electrical connector, and means for synchronizing the reading of image data, the first housing member operatively supporting the light source to illuminate a document and the rod lens to transmit any image, the means for synchronization including a synchronizing clock generator for providing clock signals being supported within the first housing;
• and
• a second image processing unit having a second housing member detachably mounted to the first housing member, the second housing member integrally supporting an image sensor for alignment with the rod lens, a second electrical connector for attachment to the first electrical connector, a signal processor for processing an output of the image sensor in response to the clock signals from the synchronizing clock generator and a detachable memory for storing the processed output.