Improvements in or relating to phototypesetting apparatus

985,041. Photographic type - composing. HARRIS - INTERTYPE CORPORATION. May 9, 1961, No. 16832/61. Heading B6W. [Also in Division G2] Photographic type-composing apparatus comprises a character matrix and a primary optical system forming matrix character images on a photographic recording material, the optical system including means for controlling the size of the recorded image, means for producing relative movement between the optical system and the recording material in accordance with character image spacing requirements, a pi character plate having transparent and opaque portions defining a pi character, means for illuminating said plate, and light-deflecting means for directing as pi character imageforming light beam into said primary optical system and through said size controlling means to record the pi character in an appropriate size. As shown, the invention is applied to the machine disclosed in Specification 891,142, and the pi character, a pointing finger on a plate 115 is supported in a frame 119 to produce by means of a second optical system 122 a reduced image in the same point size as the characters on the matrix disc 10 at a distance X from a reflector 125 equal to its distance X1 from the disc 10. Tabs or fingers 116 on the pi character plate, on insertion of the plate in the frame 119, close one or more of switches 118a . . . 118e to condition pentodes 130 (suppressor grids omitted as shown), which set the pi character relative width in binary code into the counter N of the width computer 42 of the above-mentioned machine, the desired point size being set in the counter P so that the output over line 45 represents the desired character width. When the pi character is to be recorded a switch is operated, e.g. from a push-button on the machine keyboard. This causes a switch 144 to close and operate a timer 142 controlling the lamp 120 for the pi character and also causes switch 138 to close on to the grounded contact, producing a negative pulse which has no effect. When the character has been recorded, the timer returns the switch 138 to the position shown producing a positive pulse which operates the pentodes previously conditioned by the closed switches 118 arid operates tube 150 to start the pulse generator 80. The character width is thus set up in the computer 42, and pulses are fed by generator 80 to the computer, the line length counter SM and the transducer feeding the photographic recording strip. When the computer 42 has received