Patent GB-914441-A (GB)
Title: Improvements in or relating to methods of and apparatus for justifying a line of characters
Inventor: NEWTON GEORGE CHARLES
IPC: B41B13/08
Filed: 1958-01-23
Abstract: 914,441. Photographically justifying lines of type character; anamorphotic systems. ELECTRIC & MUSICAL INDUSTRIES Ltd. Jan. 9, 1959 [Jan. 23, 1958], No. 2295/58. Classes 97 (1) and 98 (1). A line of characters is photographically justified by subjecting the complete line to anamorphic magnification by applying the anamorphic magnification successively to optical images of changing small portions of the line projected on to a receiving surface to change the length of the line by a predetermined amount and effecting further change in the length of the line by varying the interword spacings during the course of the projection of the optical images on to the receiving surface. The anamorphic justification may be applied either to a continuously-changing portion of the line of characters or to discrete juxtaposed portions of the line. As shown, a tape 1 bears unjustified lines of characters and is provided for each line with a " start of line " perforation 2 at a distance " x " from the first character and an " end of line " perforation 3 adjacent one margin at a fixed distance " y " from the last character together with a perforation 4 which indicates by its distance " z " from the margin of the tape the interline leading required. Rollers 7 guide the tape from a spool 5 into a gate 8 having a length equal to the maximum line length and a height equal to the maximum character height, the tape being driven by engagement in the perforations 3 of the tape of a claw 13 on a continuously motor-driven endless belt 9 which simultaneously returns a carriage 20 for the scanning optical system which exposes the lightsensitive surface 42 in a magazine 46, the carriage 20 being slidably mounted on guides 21 and having a slot 18 engaged by a pin 17 on the belt 9. When the line is located wholly in the gate 8, a spring-loaded pin 15 frees the tape from the belt by ejecting the claw 13 from the tape perforation 3 and itself enters the perforation to position the tape. When the tape is at rest, a claw (not shown) moves transversely of the tape from a position of zero leading until it engages in the leading perforation 4. The movement of this claw is caused to operate either an electric motor 46 or through a direct mechanical connection to apply the appropriate interline spacing movement to the recording surface 42 before projection of the characters of the line. As the tape is being fed into the gate, a fixed lamp and photo-cell arrangement 63 . . . 65 counts the number of interword spaces and causes a relay 62 to emit pulses over lead a to a relay 61 which adjusts the setting of the number of interwords input of an interword justification control device I by moving the pivot 56 of a lever 53 leftwards from position O along a slot 57 in a support-plate or carrier 68. A claw 80 spring-biased to enter the tape perforations 2 and normally holding open a switch 81 is moved to the left by the engaged tape perforation 2 so that the switch closes to energize a motor to drive a screw-shaft which moves a nut carrying the switch to the left until the latter is again opened by engaging the claw 80 so that the motor stops. Thus the motor operates for a time proportional to the distance between the perforations 2 and 3, equal to x+ly, where " l " is the unjustified line length, which is a measure of the justified line deficit (positive or negative) and so rotates through universallyjointed shafts cams 50 and 51 which control the line justification deficit or excess to be accounted for by the anamorphic magnification and interword control device respectively. Cam 50 has an increasing radius between the lines - 5 and + 5 along the arc through O and is of fixed large and small radii beyond this arc while cam 51 is uniform over the arc - 5, 0, +5 and is of decreasing and increasing radii, respectively, beyond the lower and upper value lines. The cam 50 which is on a shaft mounted in a fixed part of the apparatus controls the position of a follower lever 34 which adjusts the inclination of a truck 32 having rollers 33, 31 riding along the lever, so that the tail 32a of the truck 32 operates through an antinous cable 45 a pair of levers 45c which pivot prisms 43 about their apices to adjust the magnification of the recording optical system anamorphically Œ5% in the along-the-line direction. To avoid overlap or gaps between anamorphically magnified or reduced characters on the recording surface 42, the gate 8 is moved during projection to the left or right as appropriate by a lead-screw 23 engaging the nut 22 secured to the gate, the screw being driven as the truck 32 moves along the inclined lever 34 by a splined engagement with a reel 27 which is connected by a flexible strip 28 urged to wind up on the reel and attached to a slide 30 movable along guides on the carriage 20 and bearing the axle of the roller 31 of the truck. In the position shown, the follower lever 34 has passed beyond the variable portion of the cam 50 and the maximum anamorphic magnification of +5% is applied while the required further justification is set by the increasing radius portion of the cam 51 which is on a shaft mounted on the carrier 68 in which is formed the slot 57 and also a slot 55 for a cam follower roller 54 against which the lever 53 is held. As the carriage 20 starts to move to the left due to the pin 17 moving round the pulley 10, the source of radiation 36 and/or a shutter (not shown) are operated to project an image of a first elemental portion of the line of characters in the gate 8. When during the leftward tape scanning and image projection movement of the carriage 20 a word space is detected by the lamp and photo-cell arrangement 74 . . . 76 which moves with the carriage, relay 73 is energized and over lead b energizes solenoid 72 to rock a pawl 71 so that the spring 70 moves the carrier 68 one step to the right, the relay 61 moving with it so as not to disturb the setting of lever 53. This causes roller 77 to move downwardly under spring action so moving a wedge 26 which permits the shaft 24 and hence the gate 8 to move to the left, thus lengthening the space between characters recorded on the surface 42. After the complete justified line has been recorded, the source of radiation 36 is extinguished or the shutter for it is closed and the claws 15, 80 and the leading claw are withdrawn from the tape, for example as the result of actuation of a switch by the carriage 20 as it reaches the end of its leftward travel, the carrier 68 is moved to the left so that the cam 51, pivot 56 of lever 53, and roller 77 are in line, and cams 50, 51 are rotated to their starting positions so that their followers engage the part of smallest radius, ready for restarting of the described cycle for the next line. If the tape 1 contains a line which is not acceptable, the perforation 2 for that line is omitted so that the claw 80 is not moved and this is arranged to prevent the pin 15 from ejecting the claw from the tape perforation 3 so that the tape is passed through the gate 8 without being copied, the source 36 or the shutter for it not being energized to effect exposure. The recording surface 42 may be a material which is sensitive to ultraviolet and can be rapidly developed to provide a visible image by heating the exposed material. Such a developed exposed material may be used as the tape 1 to provide positive characters and the circuits for the photo-cells 63, 74 are arranged to signal interword spaces when the cells receive maximum radiation. Modifications.-Alternatively the tape may be opaque with transparent characters when the interword spaces are detected by receipt of minimum radiation. As a further variant the tape 1 need not be produced photographically but could be formed by ordinary printing methods or by means of a typewriter. Instead of using mechanical devices to detect the tape perforations, electrical feelers or contacts may be employed and instead of energizing and deenergizing the electrical motors used, the motors may be continuously running and coupled to the appropriate parts as required by electromagnetically-controlled clutches operated from the perforation detectors. Further, instead of the perforations the tape may bear marks which are detected photo-electrically. Different interword spaces in a line of characters could be indicated by coded groups of indicia and similarly detected. By compressing the characters on the tape 1 in width by 5%, an anamorphic expansion of 0-10% may be applied instead of reducing and expanding uncompressed characters by not more than 5%, this resulting in changes of the angular pivoting of the levers 34, 53 and in the compensating movement of the gate 8 during projection by the lead-screw 23 being in one direction only. The continuous projection of elements of the line may be replaced by intermittently energizing the source 36 and/or opening a shutter to effect projection when the carriage is stationary or intermittently projecting images of successive elements of the line either only when the carriage is stationary or while moving the carriage continuously. The Provisional Specification also refers to effecting justification by combining with anamorphic magnification alteration of the intercharacter spaces as well as or instead of altering the interword spaces.