Patent GB-980183-A (GB)
Title: Improvements in or relating to printing machines
IPC: B41J21/16
Filed: 1961-06-30
Abstract: 980,183. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION June 30, 1961 [July 5, 1960], No. 23684/61. Heading B6F. [Also in Divisions G1 and G4] In a typewriter wherein the work form to be typed is supported by a carriage movable relatively to the printing position, the movement of the carriage is controlled through the sensing of indicia on a programme form, so that when the printing members are operated either manually or by signals fed to the machine, items are positioned along a line as required according to the indicia on the programme form. The line spacing may also be determined by indicia on the programme form. The work form may be stationary during printing of a line, and the printing mechanism moved along the printing line. In an arrangement, whereas the machine keys can be operated either manually or by electric signals, an extended platen 14, Fig. 1, is provided and the programme form 17, which has transparent and opaque areas, is mounted on the extension so as to move horizontally and vertically with the work form 16. Opaque areas in a column 26 adjacent to the left edge of the form 17, Fig. 3, indicate that matter is to be typed on horizontal lines corresponding to the areas, and opaque areas 28 in the next column and used to control vertical tabulation. The remaining opaque areas 25 indicate where printing is to be effected on the form 16 and control the horizontal movement of the carriage. A fixed sensing device 20 comprising photosensitive elements F, V, 0 . . . 7, Fig. 6, in line with the printing station 11, Fig. 1, and spaced according to the character (i.e. column) spacing is so positioned that when the carriage is in its extreme rightward position, the element F is opposite column 26 and the element V is opposite column 28. The element 0 is always opposite that column of the form 17 corresponding to the column of form 16 at the printing position 11, so that elements 1 . . . 7 sense columns corresponding to columns of the form 16 in which successive characters may be required to be printed. The photo elements control inverters 54 . . . 62, Fig. 5, whereby inverse signals, e.g. 0, 0, in respect of element 0, are fed to typewriter control circuits 22 depending on whether a transparent or an opaque area is sensed by an element. The circuits 22 provide signals controlling the typewriter actuating circuits which include solenoids 82 . . . 85 operating carriage return, spacing, tabulating and stop tabulating devices, and also skip, vertical tabulation, left-hand margin and righthand margin switches 89 . . . 92. The mechanically-moved part of each solenoid 82. . . 84 opens a switch 86 . . . 88 in a circuit common to the solenoids when the corresponding solenoid is actuated, so that actuation of one solenoid prevents actuation of the other. Actuation of tabulation solenoid 84 in addition to opening the switch 88 closes a switch 107 in the circuit of stop tabulate solenoid 85. The latter operates a pawl which is moved to catch on the fly one of the tabulation stops, all of which are set, and is actuated three spaces in advance of the required tabulating position. A trigger circuit 93 supplies a signal to the control circuits when a skip signal is received and a similar circuit 94 provides a signal to operate vertical tabulation when the left-hand margin switch is closed and a tabulation mark is sensed at column 28, Fig. 3. A third trigger circuit 95 supplies either a signal L for operating the carriage return solenoid 82 or a signal L indicating that the machine is operating in a column search mode, i.e. it is printing along a line. In operation, assuming that element F senses an opaque area in column 26 and element V senses a transparent area, i.e. matter is to be printed on the line at the printing position, the elements 0 . . . 3 control the carriage movements so that items received from a data source 23, Fig. 1, are printed on the form 16 at places corresponding to the opaque areas on the form 17. Where a transparent area occurs between opaque areas on the same line, if the start of the second area is three columns or less away from the end of the first area, the carriage is letter-spaced from one area to the next. If the spacing is greater than three columns, the sensing causes tabulation of the carriage. Actuation of the skip switch by the operator or by a skip instruction also causes the carriage to space or tabulate to the next printing field. The sensing by the elements 0 . . . 7 also controls the sequential coupling of signals to the typewriter from a character storage register having a number of character positions corresponding to the number of elements, each character being stored in binary units. The programme form may be an endless band whereby the same formate may be effected on successive sections of a continuous work form. In the case where the work form is stationary during printing of a line, the movable printing device may comprise type-wheels. In a modified arrangement, the programme form 17 is not movable with the work form, but remains in one position between a planar light source 232, Fig. 12, comprising horizontal luminescent strips 233 corresponding to the lines on the work form and the programme form, and a planar photo-sensitive element comprising vertical photo-conductive strip 237 corresponding to columns. The strips are coupled to external contacts 228, and a selector device 230 movable with the typewriter carriage makes contact with selected sets of the contacts 228 as the carriage moves. An endless perforated strip driven by the platen or starwheels coupled to the line-spacing mechanism of the machine energizes the one of the luminescent strips 233 corresponding to the line to be printed and scanning of the sheet along that line provides signals as in the first arrangement to control the movements of the carriage.