公开(公告)号：DE1549756A1

公开(公告)日：1971-04-15

申请号：DE1549756

申请日：1967-03-04

Applicant: IBM

Inventor： WARNER HARDIN WILLIAM ,  JOSEPH KENNEDY JAMES ,  RUSSELL PLUMMER NORMAN

IPC: G06V30/144 ,  G06K9/16

Abstract: 1,117,854. Pattern recognition. INTERNATIONAL BUSINESS MACHINES CORPORATION. 13 Feb., 1967 [14 March, 1966], No. 6710/67. Heading G4R. Apparatus for controlling the movement of a beam of radiation scanning around a pattern comprises means for defining a band of predetermined width extending across the pattern and for defining an area displaced from the band and on the periphery of the pattern, and means for determining when the beam has scanned across the band and area to indicate completion of a scan cycle. The photomultiplier 9 of a flying-spot scanner 5, 9 controls, via AND 47, attenuation 26, 27 of sine and cosine voltages being fed to Y and X integrators 29, 28 providing the vertical and horizontal deflection voltages for the scanner so that the outline of the character to be recognized is followed round. The maximum and minimum vertical deflection voltages during following round are stored at 33, 35 and in order to move to the next character the average of these voltages is compared 31 with the current vertical deflection voltage to control attenuation 26, 27 via AND 39 so that the beam follows an imaginary horizontal boundary to the next character. A voltage divider R11 to R14 specifies the upper and lower limits of a horizontal stop band (which should contain the scan path between characters) to comparators 67, 69 which also receive the vertical deflection voltage to indicate whether the beam is within the stop band at any given time. When the beam has been following round a character for a predetermined time, as indicated by an output at V derived from the photomultiplier 9 being present for this time, and the beam is not in the stop band, a latch 71 is set, thus causing the current vertical and horizontal deflection voltages to be stored at 63, 51, voltage dividers R7 to B10, R3 to R6 supplying predetermined fractions of the stored voltages to comparators 59, 61, 55, 57 to specify the limits of a stop box. The comparators compare these limits with the vertical and horizontal deflection voltages to specify whether the beam is within the stop box at any given time. Setting of the latch 71 enables a latch 81 to be set as soon as the beam is next in the stop band but not in the stop box, and this enables a latch 95 to be set as soon as the beam is next outside both stop band and stop box. Setting of latch 95 allows a latch 99 to be set as soon as the beam is next inside the stop box and this allows a latch 103 to be set as soon as the beam next leaves the stop box. Setting of latch 103 applies signal CCDO to the recognition system 13 to indicate completion of following round the character (e.g. to initiate a character recognition scan, the first scan being for normalization).

公开(公告)号：DE1574708A1

公开(公告)日：1971-05-27

申请号：DE1574708

申请日：1968-02-23

Applicant: IBM

Inventor： WARNER HARDIN WILLIAM ,  JOHN NORMAN REINI

IPC: G06K9/32 ,  G06K9/04

Abstract: 1,209,361. Character recognition. INTERNATIONAL BUSINESS MACHINES CORP. 26 Feb., 1968 [28 Feb., 1967], No. 9109/68. Heading G4R. _ Character recognition apparatus performs a main scanning cycle, comprising a recognition scan of one character interleaved in time with a registration scan of another, data from the registration scan controlling a subsequent main scanning cycle. Vertical and horizontal deflection voltages for flying-spot scanner 22, 24 are supplied by respective integrators 52, 54. The scanner beam is positioned at the right hand end of a line of characters, then the beam executes a curlicue pattern progressing horizontally leftwards until the first character (2 in Fig. 3) is encountered when the flip-flops 64, 66 are reset to release resettable amplifiers 30, 28 to follow the deflection voltages (minus the curlicue, filtered off at 70, 68) which they do as if the voltages were zero when release occurred, i.e. they specify the subsequent changes. The curlicue follows round the outline of the character, positive movements of the vertical and horizontal amplifiers 30, 28 being followed and held by track-holds 144, 104 respectively. After the character has been followed round once, the track-holds 144, 104 hold voltages representing the top and right edges of the character respectively, these voltages being applied via switches 148, 102 to vertical and horizontal potential dividers 94, 92, tapped voltages from which are applied to a normalization matrix 32 as in Specification 1,013,036 to specify a matrix subdivision of the character. The scanner now performs the path consisting of straight line segments 1-13 shown in Fig. 3 under control of gating logic 72, for recognition of the first character and registration of the second, the points at which to change from one segment to the next being indicated by comparison of the vertical and horizontal deflection voltages (from amplifiers 30, 28) with voltages tapped from the voltage dividers 94, 92. The comparisons are done by voltage discriminators 82-91 (Fig. 2A, left) except where otherwise stated. When during scan segment 2, the beam reaches the centre of the first character, discriminator 108 (Fig. 2B) produces a start-of-vertical-scan signal from OR 112. This signal resets the horizontal amplifier 28 to ground, locks the horizontal centre in voltage divider 92 to ground via switch 114, sets flip-flop 168 (Fig. 2A) and resets flipflop 178. When the character is encountered in scan segment 3, threshold detector 98 sets flip-flop 178 which reverses the current state of flip-flop 183, resets flip-flop 146, and causes one of flip-flops 190-192 to be set by gates 170-172 according to whether encounter of the character has occurred in a top, middle or bottom portion thereof. The gates 170-172 are controlled by the voltage discriminators 88, 90 for this purpose. Flip-flops 193-195 and gates 173-175 perform the same function. Assuming that flip-flop 183 was in state 0 and is switched to 1 on encounter of the character, track-hold 184 was following the vertical amplifier 30 but is prevented from changing when flip-flop 183 is set to 1. The voltage in track-hold 184, representing the top of the character, is passed to vertical voltage divider 94 (Fig. 2B), with or without correction by a voltage divider 185 (Fig. 2A) depending on which of the flip-flops 190-192 was set, the flip-flop closing one of switches 150-152 via ANDS 160-162. Had the flip-flop 183 been in the opposite state when encounter of the character occurred, track-hold 186 and associated circuitry (bottom of Fig. 2A) would have been used for the same purpose instead. Two sets of circuitry are thus provided, each used during alternate scan segments 3. At the end of segment 3, flip-flop 66 is reset to release horizontal amplifier 28. During segment 6, while the scan is to the left of the first character (as indicated by voltage discriminator 120 controlled from the horizontal voltage divider 92 and the horizontal amplifier 28), track-hold 126 (Fig. 2B, top) follows the horizontal amplifier 128 until the second character is detected (which sets flip-flop 122). During segment 10, track-hold 128 functions like trackhold 126 in segment 6. Voltage discriminator 130 controls switches 132, 134 to pass the larger of the voltages in track-holds 126, 128 to voltage divider 138. This voltage represents the horizontal position of the rightmost encounter with the second character (6 in Fig. 3) during scan segments 6 and 10. The voltage divider 138 supplies a voltage representing the horizontal centre of the second character to voltage discriminator 142. Vertical misregistration of the second character too great for the above arrangements to correct for is detected during scan segments 4 and 12 when detection of a character will set a flip-flop 214. Horizontal misregistration too great for the above arrangements to correct for is detected if the second character . is not encountered during scan segment 6 or 10 in which ease a flip-flop 204 will remain reset. In either event, OR 206 causes segment 13 to be followed by a segment 14b in which the beam moves down until it reaches the middle position specified by the vertical voltage divider 94, then the beam executes a horizontally progressing curlicue until the second character is encountered, then follows it round as with the first character of the line. On the other hand, in the absence of an output from OR 206, segment 13 is followed by segment 14a which is horizontal movement to the left until the horizontal centre of the second character is reached when voltage discriminator 142 (Fig. 2B) produces the startof-vertical-scan signal from OR 112 which causes scanning of the second character to start with segment 3.

公开(公告)号：DE1922373A1

公开(公告)日：1969-12-18

申请号：DE1922373

申请日：1969-05-02

Applicant: IBM

Inventor： WARNER HARDIN WILLIAM

IPC: G06K9/38 ,  G06K9/00

Abstract: 1,262,001. Differential amplification. INTERNATIONAL BUSINESS MACHINES CORP. 14 May, 1969 [24 May, 1968], No. 24467/69. Heading G4G. In the differential amplifier 16, resistance R 3 is made unequal to resistance R 4 such that the output of the amplifier is the difference between multiples of the inputs. In the optical character reading device shown, the inputs to the amplifier 16 are the peak black and white levels detected by scanning device 10. The device is used to scan an initial character (e.g. the first letter of a line of print) in order to establish a clipping level at which the reading device operates after the initial scan (e.g. during the rest of the line). The clipping level is established by storing the output of amplifier 16 in a store 30 and adding to it in adder 32 a voltage representing the peak white level. The inequality of the resistances R 3 , R 4 ensure that the clipping level varies with the density of the characters.