Patent GB-866016-A (GB)
Title: Improvements in or relating to photographic projection printing apparatus
IPC: G03B27/46
Filed: 1957-06-25
Abstract: 866,016. Photographic projection-printing apparatus. EASTMAN KODAK CO. June 25, 1957 [June 26, 1956], No. 20000/57. Class 98(1) In a projection printer in which elements bearing several images are taken from a supply stack to a projector and from the projector to a receiving stack, each element is moved stepwise through the projector to locate its images successively. on the projection axis and the light-sensitive image receiving material is changed after each step-wise movement. Preferably, the elements are supported during their movement from the supply stack to the receiv-. ing stack by a carrier. As shown in Fig. 17 a film element 30 is mounted on a carrier 85 and located thereon by a pin 89 entering a slot 31 and abutments 90, 91, 92. The printer is automatically controlled to print by the presence of indicia 35 and 36. The printer reads the bits represented by the indicia 35 and 36 into a magnetic core register 308 (Fig. 19A) before the element reaches the projector. Photo-cells 79 and 78 respond to indicia, 35 and 36 respectively and a further photo-cell 81 is operated by apertures 93 in carrier 85. Certain indicia 36 may be punched out so as not to operate cell 78 and, accordingly, to prevent the corresponding images from being printed. Further selection of the image to be printed is obtained by switch 287. When switch 287 is closed every image area for which an indicium 36 remains will be printed. When switch 287 is open only image areas for which a combination of indicia 35 and 36 are provided will be printed. "And" gates 400-403 and "or" gate 404, 405 are arranged to transmit a pulse only when a print is to be made. The element 30 also has a variable area 33 of code bits which extends over from two (as shown) to twelve image areas. It is not intended to print the code area and accordingly each column of code has a mark 34 which is an instruction to the printer to ignore any indicia in the two lowermost rows of code (to which photo-cells 78 and 79 would spuriously respond). Marks 34 operate photo-cell 80 and the signal is combined with the signal from photocell 81 at "and" gate 406, 407. A final "and" gate 408, 409 determines the signal fed to magnetic core 121 of register 308. A signal from photocell 81 produces two shift pulses which each shift all bits from one core to the next. One pulse from 302 is stated to act at the same time as the bit is fed into core 121 but the second pulse from 322 is delayed. The circuits of amplifier 288, trigger components 292, cathode followers 294, 296 and 309, detection component 297 and single shot multi-vibrators 301 and 303 are more fully described as typical of the circuits employed. Projector housing 57 can be moved by a cam between two positions aligned respectively with either row of image areas which are referred to as the E row and the O row. The printer is driven by a continuously running electric motor 100 and drive shafts are successively coupled with this motor to perform the sequence of operations. Solenoid controlled drive shafts turn through either a half or a whole revolution at each actuation of the solenoid. To collect an element 30 from stack 40, with the carrier 85 in position thereat, solenoid MC is energised by the start button and frees clutch 131 (Figs. 13, 14 not shown). Cam 154 on the drive shaft turns through one half a revolution and operates plunger 165 through arm 157 to place the element on the carrier. Relays and cams (not shown) are thus operated to close switches to energise magnetic clutch CC so that the carrier is driven by motor 100 by means of belts 109, 118 past the reading station 74 to the projector. The carrier then operates switches CES to de-energise clutch CC and is positioned by the engagement of locating pawl 258 with a rack 98. Spring motor 115 is wound during the forward movement of the carrier and draws it into engagement with pawl 258. Meanwhile other switches have energised a solenoid to open a shutter 275 and prepare photocells 78-81. In the projection position a solenoid is energised so that a half turn of a device shaft (Fig. 3, not shown) lowers a transparent plate 217 (Fig. 11, not shown) and element 30 is held flat thereagainst by suction. Cams on the drive shaft operate switches and switch GLB2 (Fig. 19B) is thus closed. Solenoids LC and IC are provided to couple drive shafts of a projector housing moving cam (Fig 3, not shown) and a carrier moving eccentric (Fig. 6, not shown) to the motor 100 for a half and a whole revolution respectively. These drive shafts carry cams which operate switches LCE1, LCE2 and LCE3 (closed when the projection axis is aligned with the'E'row of image area) LC01, LC02 (closed when the projection axis is aligned with the O row of image areas) and LCA1, ICA1, ICB1, ICC1. Switch CE4 is closed by the carrier 85 as it enters the projection position. Thus solenoid IC is immediately energised through CE4, 04, E4, GLB2 and ICA1 to allow the carrier 85 to be moved one step forward to position the first pair of image areas in the projection axis. Switches ICB1 and ICC1 are alternately operated by a cam on the drive shaft of the carrier moving an eccentric to generate four shift pulses so that the bits stored in magnetic cores 1<SP>1</SP> and 21 are applied to relays E and O: For the first three pulses contact ICA1 is held open. Energisation of relay E closes switches E3, E5 and E7 and opens switches E2, E4 and E6 and results in the projection of an image area in the E row. Energisation of relay O closes switches 02, 04 and 06 and open switches 03, 05 and 07 and results in the projection of an image area in the O row. The four shift pulses thus set the switches E2-7 and 02-7 so that the circuit of Fig. 19B complies with the signals applied to relays E and O for each pair of image areas. On completion of the projection and projection housing movement the solenoid IC is energised to move carrier 85 by one step to position the next pair of image areas, to operate switches ICB1, ICC1 and open switch ICA1 to deenergise relays E and O If neither relay E or O is energised the path CE4, 04, E4, GLB2 and ICA1 is not interrupted and the carrier movement is continued for a further step. The exposure of light sensitive material 277 is effected by lighting projection lamp 64. The duration of the exposure is timed by a known relay controlled timer. Material 277 may be cut by knife 283 before being transferred by belt 284 to processing apparatus. When the projection has been completed, transparent plate 217 is lifted by a cam on a drive shaft and moved back into its original position by a return spring. Clutch CC is energised and carrier 85 moves towards the receiving stack 50. On reaching the stack, the carrier closes switch EC to energise solenoid MC. Clutch 131 thus turns a cam similar to cam 154 through half a revolution and carries a plunger (Fig. 7A, not shown) to insert element 30 in stack 50. Solenoids CR1 and CR2 are then energised to move pawls 258 and 261 out of the path of carrier 85 so that it can return under spring motor 115 to the supply stack 40. On reaching the supply stack 40 the carrier 85 operates switches CH to close shutter 275 and re-energise the solenoid to start the next cycle. The printer continues to operate until the stack 40 is emptied. If however the projector lamp 64 or the photocell reading lamp (Fig. 16 not shown) burn out, the carrier 85 returns to the supply stack 40 and remains there. If no image areas on an element are to be projected the thyratron 313 is not fired to actuate a relay and the carrier 85 passes through the projector without stopping. If the carrier 85 has failed to collect an element 30 its absence is detected through the absence of marks 34 and consequent non-firing of thyratron 312 and the carrier is returned from the reading position to the supply position to re-collect.