US 201213563563 A description fig1 illustrates the digital imaging apparatus suitable for use in accordance with a preferred embodiment of the present invention the imaging apparatus 1 comprises a microscope 3 having a motorised microscope stage 5 for holding a microscope slide 7 and an optical subsystem 9 including an objective lens 11 and eyepiece 15 an example of a suitable microscope is the axioplan 2 imaging microscope available from carl zeiss of germany using an apochromat objective lens the stage may be any suitable motorised stage having the necessary positioning accuracy for example the proscan stage available from prior scientific instruments limited of cambridge uk the motorised stage 5 is driven under the control of a stage controller 17 which controls the stage in response to instructions from computer 19 the motorised stage 5 is typically driven only in the x and y directions in addition focusing of the microscope is controlled by a piezo electric controller 21 which controls a focussing device 21 a which moves the objective lens 11 towards and away from the slide 7 along the axis of the optical system 9 to focus the microscope 3 under control of computer 19 a suitable piezo electric focusing controller 21 is available from physik instrumente of germany the imaging apparatus 1 additionally includes a digital camera 25 preferably a high.