GB1476694A - Acquisition system for slide analysis - Google Patents

Abstract

1476694 Positioning a slide CORNING GLASS WORKS 20 Sept 1974 [26 Sept 1973] 41039/74 Heading G1A In an apparatus for adjusting the position of a specimen, a blood cell, on an analytical slide 10 for microscopic analysis using a vidicon target scanning unit 36, the slide is positioned by means of a X positioning motor 56 and a Y positioning motor 54, under the control of logic circuitry 52, until the image of a specimen is central of an aperture 28. Light from a source 12 is directed via a lens 14, fold mirror 16, condenser lens 18 and the slide 10 on to a beam-splitter 22 that directs some of the slide's image to rotating multi-faceted mirror and some of the light via mirrors 24 and 26 to an aperture 28 in front of the vidicon unit. (The vidicon unit blood cell classification is subject of copending Application No 16412/74 Pat No 1456317). The rotating mirror effectively scans the slide 10, in the "X" direction, also Figs. 2A- 2D (not shown) and the reflected beam is directed as shown on to a photo-sensitive device 40 (The other two photo-sensitive devices form part of the automatic focusing system subject of Specification 1476693). The photo-sensitive device 40 produces a pulse signal when the area of the slide being scanned contains a specimen of interest, and this pulse signal is sent via pulse shaping circuitry 46 to the logic circuit 52 that also receives a pulse signal from a source 48 and detector arrangement 50 that are arranged, as shown, to produce a synchronization pulse at the beginning of each scan. The logic circuitry 52, also Figs. 3A, 3B, 3C (not shown) produces a "normal stage motion signal" at the end of each scan within which no specimen has been detected, and this signal is applied to the "Y" positioning motor 54 to move the slide one increment in the "Y" direction. The logic circuitry uses the synchronization signal to produce a centre pulse signal which occurs in the middle of each scan and this signal causes, when a pulse due to a specimen occurs, the activation of the "X" positioning motor 56 which drives the slide in the "+X" or "-X" direction depending on whether or not the specimen signal occurred before or after the centre pulse signal. The X positioning motor 56 is activated until the specimen is at the centre of the scan and when this happens a specimen centered signal is produced which stops the X positioning motor 56 and activates the vidicon scanning unit 36 to scan the specimen blood cell.