公开(公告)号：US3829222A

公开(公告)日：1974-08-13

申请号：US34464473

申请日：1973-03-26

Applicant: SAAB SCANIA AB

Inventor： ASLUND N

IPC: G01D5/34 ,  G01J3/40 ,  G01N21/22

CPC classification number: G01J3/40 ,  G01D5/341

Abstract: Density variation across a localized area of a photographic plate is detected by directing a beam through said area and thence onto a photoelectric detector through a narrow slot at the imaging plane. Relative motion is effected between the beam and the slot, hence detector output varies with density across the scanned zone. A fiducial mark carrier is in a separate beam (preferably emanating from the same source) which follows a path in bypass relation to the plate but which is combined with the image carrying beam at the slot. Light filters in the respective beams enable separate electronic processing of image beam signals and fiducial mark beam signals.

公开(公告)号：US3809482A

公开(公告)日：1974-05-07

申请号：US34741773

申请日：1973-04-03

Applicant: SAAB SCANIA AB

Inventor： ASLUND N ,  PETTERSSON S ,  ANGELSTRAND S

IPC: G01J3/28 ,  G01J3/40 ,  G01N21/59 ,  G01N21/06 ,  G01N21/22

CPC classification number: G01J3/40 ,  G01J2003/2866 ,  G01N21/5911

Abstract: An image beam from a constant intensity light source is passed through a small area of an image on a photographic plate, thence through a variable width scanning slot and onto a photoelectric detector. Relative scanning motion between beam and slot is effected in directions transverse to slot length. A second beam from the same source is directed around the plate, through the slot and onto the detector. The beams fall on the detector alternately, in synchronism with scanning, so that the second beam produces calibration pulses. Detector output is so amplified as to maintain amplified calibration pulses at constant magnitude.

Abstract translation: 来自恒定强度光源的图像光束通过照相板上的图像的小区域，然后通过可变宽度的扫描槽并到达光电检测器。 光束和狭缝之间的相对扫描运动在横向于槽长度的方向上进行。 来自相同源的第二个光束被引导在板周围，穿过槽并且到达检测器。 光束与扫描同步地交替地落在检测器上，使得第二光束产生校准脉冲。 检测器输出被放大，以将放大的校准脉冲保持在恒定幅度。