Further, thyratron 64 is prepared for the reception of some other defect pulse by the momentary opening of microswitch 75 which interrupts the HT supply to thyratron 64. The angular position of switch 75 is displaced a few degrees clockwise relative to the position of switch 62. while switchm 62, 7d and 75 are operated by one or more shaped disc members at tached to the mechanism of the rotating cutter 14. The rotation of the cutting blade 14 is anticlockwise. In FIG. 7, three shaped disc members are shown together with microswitches 62, 74 and 75, however, other switches such ‘as the commutator type with brush pick-ups may be employed. When the distance between the cutting position E and point F of the grading switch is greater but is of the order of the length of the cut sheets, the hereinbefore described method and means for producing the required delay is satisfactory. Other and more complex means may be employed when the speed of the carrying tapes 15 is not constant or when the distance between points E and F is much greater than the length of a cut sheet. In all cases, the delay must be such that the grading switch is de?ected just before the leading edge of a defective sheet approaches the edge 17 of the grading switch 16. In the operation of the invention thus far described, sheet paper 2 is fed from a large roll to auxiliary rollers 3 and 4, such rollers eliminating flutters and folds in the paper sheet. The paper then passes over inspection mem ber 5 after which, by means of draw rollers 11 ‘and 12, the paper sheet is moved from the inspection member 5 to the point E where it is cut into sections or lengths by means of cutting members 13 and 14. Immediately above inspection member 5, the paper 2 is ?ooded with strong, uniform light by means of the ?uorescent lamps 8. The lamps 8 are ‘arranged close to the paper surface and on opposite sides of the long, narrow aperture 7 so that the light rays therefrom are. directed downwardly on to the surface of the paper on the inspection member 5 and are then re?ected upwardly through aperture 7 to the photoelectric cells 6. As the sheet paper moves over the inspection member 5 and a defect appears in that portion of the paper be neath the aperture 7, the diffused, re?ected light rays falling upon the photoelectric cells 6 will increase or de crease the current of the photoelectric cells according to the nature or‘ characteristics of the defect and such changes in the current produce a corresponding voltage change such as signal 36 at the input of ampli?er 3-7. The ampli?ed signal 38 produced by the direct channel, or .also shown in FIGS. 2. and 3. 11 signal 42 produced by the integrator 41, passes the genera tor 39 and produces output pulse 43 which, in turn, ac tuates grading switch 16. ' At the instant the defect in the paper appears beneath aperture 7, output pulse 43 is produced. This output pulse is then delayed by a time period which is de?ned by the time period in which the said defect moves from be neath aperture 7 to the stationary cutting blade 13. The grading switch 16 moves upwardly at the instant the sta tionary and rotary cutting blades 13 and 14 meet to cut the defective sheet of paper. The defective sheet of cut paper is then carried to compartment 19 by tapes 15. When the cut sheets of paper are without defect, the de ?ector 16 remains stationary and such ?rst grade paper is carried to the ?rst grade compartment 20 by tapes 18. Referring now to FIG. 8 of the drawings, the lines numbered 77, 78, 79, 80, 81, 82, ‘83 and 84 represent the photoelectric cells shown in FIG. 2 and FIG. 3, such lines also give visual representation of the aperture 7 In practice, lines 77 through 84 meet and represent a part of the continuous aperture 7. The lines 77 through 84 also indicate equal sections of the sheet material under inspection, each such section being viewed by one, two or more photoelectric cells. The number of photoelectric cells viewing each section from 77 to 84 are equal. The cathode of the photoelectric cells, as for example seen at numerals 23 to 26 in FIG. 4, viewing sections indicated by numerals 77 and 79‘, are connected together and are connected by link 85, which may be a cathode or anode follower stage, such as is indicated by numeral 32 shown in FIG. 4, to one of the input control grids of ampli?er 87 which consists of the heretofore described long-tailed pair stages. Similarly, photoelectric cells viewing sections 81 and 83 are connected together and are connected by link 86 to the other input control grid of ampli?er 87. Sections 78, ‘80, ‘82 and ‘84 are interleaved with sec tions 77, 79, 81 and 83 and the photoelectric cells view ing sections 78, 80 and '82, 84 are connected by links 88, 89 to the two input control grids of ampli?er 90. Ampli?er 90 is identical in all its characteristics to am pli?er 187. According to my invention, the main rule of connec tions is that adjacent sections such as 77, 78 or 79, 80 and so on, are connected to different ampli?ers and that to each control grid of such ampli?ers the same number ' of photoelectric cells are connected and thus view sec tions of equal lengths. The number of ampli?ers used can be two or more, however, the number of sections used must be an even number. As an example of this, an alternative arrangement satisfying the aforementioned principle of connection is shown in ‘FIG. 9. ' 光电检测与分选机器英文文献和中文翻译(6):http://www.youerw.com/fanyi/lunwen_35843.html