Patent SE-315133-B (SE)
Inventor: MUIR D
IPC: G01B11/02
Filed: 1964-01-13
Abstract: 1,066,841. Selective signalling systems. MOLINS ORGANISATION Ltd., and D. W. B MUIR. Jan. 14, 1964 [Jan. 14, 1963], No. 1589/63. Heading G4H. A vidicon tube or flying spot scanner 1, Fig. 1A, is used to scan articles such as cigarettes in order to measure the length of the cigarettes, the length of the filter tips, and, if desired, the length of a printed area on the cigarettes. The apparatus is also used to check the quality of the printing in a predetermined area of the cigarettes. The cigarettes are rotated while being scanned so that the entire surface is examined. Signals from scanner 1 are applied to a differentiator 6 which is connected to an amplitude discriminator 7 providing pulses on leads 8, 9, 10, 66 in accordance with the amplitudes of pulses supplied thereto. A trigger 13 is set by a start of line scan pulse and enables gate 12 so that a pulse on line 8 representing the scanning of the leading edge of the cigarette sets trigger 16 and enables pulses from crystal oscillator 22 to pass through gate 46 to a three decade counter 47, Fig. 1B. Switches 49, 48 are preset to represent lower and upper acceptable limits for the length of a cigarette. When the lower limit is reached, gate 55 is enabled and trigger 61 is set. A pulse on lead 9 from discriminator 7 opens gate 62 when the scan reaches the trailing edge of the cigarette, and providing the upper limit has not been previously exceeded and trigger 61 reset through gate 54, trigger 63 is set to indicate that the length is within the preset limits. Trigger 63 remains reset if the length is below the lower limit since trigger 61 is not set before gate 62 is enabled. The process is repeated for each of the 25 line scans which are performed in examining each cigarette. In a similar manner the length of the filter tip is examined to check that it lies within limits which are preset on switches 50, 51. Trigger 64 is set when the lower limit is exceeded and gate 65 is opened by a pulse derived from lead 66 of discriminator 7 when the leading edge of the tip is scanned, an acceptable length being registered by setting trigger 70. At the end of each line scan, a trigger 73 is set if either the cigarette length or tip length has been found to be incorrect. Further switches 52, 53 are preset to values representing the acceptable limit positions for printing on the cigarettes. Trigger 80 is reset when the lower limit is exceeded, and thereafter pulses are supplied through gate 81 to a counter 82 which represent the density of the printing within the selected limits. Another gate 88 is opened when the scan is outside the limits set on switches 52, 53 and supplies pulses to a further counter 89 which are representative of the number and density of undesired marks e.g. displaced printing. Counters 82, 89 accumulate pulses over all 25 line scans, thus trigger 87 is set if the printing quality is within the preset limits, and likewise trigger 94 is set if the amount of undesirable marking is acceptable, when the entire surface of a cigarette has been examined. The outputs of triggers 87, 94 are gated with that of trigger 73 and provide an error signal on lead 98 which may be used to reject a cigarette which fails to conform with any one of the preset standards.