Methods and apparatus for use in imaging an object

Abstract

The present invention concerns methods and apparatuses for imaging an object by detecting radiation reflected from and/or transmitted through the object (O;P;M) using an imaging sensor system. To perform an optimized selection between the imaging resolution and the sensitivity of the imaging sensor, the sensor system is configured by means of a control scheme based on combining, or binning, the radiation-responsive imaging elements of the imaging sensor along the rows and/or columns of the sensor matrix into clusters of a plurality of imaging elements. The sensor pixel charges, which represent the image information obtained from the individual imaging elements of said clusters, are straightforwardly binned into the clusters in their charge form. According to a second method of the invention, the TDI-mode imaging technique is applied and a mutual, relative motion is arranged between object to be imaged and the imaging sensor. The charge-mode image, which is formed from the object to be imaged on the CCD sensor elements, is transferred at the same speed with said relative movement and the image information gathered from the object is accumulated for an extended time simultaneously achieving an increased sensitivity of the sensor. The physical pixel size of the sensor is selected smaller than that required to achieve the maximum resolution required from sensor and that the image blur caused by the relative movement between the object to be imaged and the imaging sensor is reduced by shifting the pixel charges in synchronized steps corresponding to the physical size of the CCD sensor pixels, whereby the tracking of the relative movement between the object to be imaged and the CCD sensor occurs with maximum accuracy.