GB1428732A - Apparatus for displaying features having a predetermined parameter occurring within a particular field of an image - Google Patents

Abstract

1428732 Automatic control of position; scanning microscope slides NUTRITIONAL RESEARCH UNIT Ltd [trading as HUNTINGDON INSTRUMENTS] 3 April 1974 [5 April 1973] 16387/73 Headings G2J and G3N An apparatus for displaying features having a predetermined parameter with a particular field of an image comprises a microscope, an optoelectronic converter, a detector, connected to the converter output, of features having the predetermined parameter a store for the co-ordinates of the features and a control circuit for a drive means of the microscope whereby each feature detected is sequentially displayed. As shown, a stage 2 of a microscope 1 is positioned by a stepping motor drive 10 in response to signals from a logic control 9 connected through a read circuit 8 to a MOS dynamic store 7, or directly to a feature store 17 and a manual positioning control 15. A slide to be examined is mounted on the stage 2 and positioned manually to a reference position by the control 15. A co-ordinate button 17 is then depressed to record the position in store 17. A zone of interest on the slide is then found and the store 17 updated. The zone of interest is scanned, at low magnification, by a T.V. camera 3, monitored by a screen 21, and the amplified video signals passed to a detector 5, set manually at the signal amplitude corresponding to a desired feature. The co-ordinate positions of detected features through a load control 6 are set in the store 7. During the subsequent read-out of detected features, at a high magnification selected by the actuation of an objective turret 12, via a logic control 9 an operative can decide on the nature of the detected feature, e.g. a type of bloodcell, and press an appropriate count button 22 to up-date counters in an accumulator 23, with associated display 33, or reject by depressing a button 16. A total count is maintained in an accumulator 28 and a desired number of bloodcell analyses set by a thumb-wheel; completion of a count being shown on an indicator 31 energized by a comparator 30. Facilities are provided for selecting a fresh zone of interest if the zone selected does not provide sufficient features for the desired number of analyses.