Patent GB-1082133-A (GB)
Title: Improved mask selecting and positioning apparatus, for example for use in radiation-type printing or composing apparatus
IPC: G06K15/12
Filed: 1964-09-22
Abstract: 1,082,133. Photographic type-setting; typewriters. H. GERMER. Sept. 22, 1964 [Sept. 23, 1963], No. 38570/64. Headings B6F and B6W. In character selection apparatus for the projection and radiation type printing art, and particularly for a typewriter in which a selected character mask is interposed between a source of radiation and a ribbon carrying ink particles which soften under the influence of the radiation, and mechanical means causes the ribbon to deposit the softened particles on a recording surface such as paper, there is provided in an array at least two mask carriers each carrying a plurality of masks, the carriers having their surfaces in parallel planes and being displaceable with respect to each other in selectable amounts each in both of the co-ordinate directions lying in the plane of its surface, so that depending on the direction of the displacement, single selected mask is moved into a path of the rays while the or each carrier carrying the unselected masks disposes a radiation permeable area corresponding in size to a mask in the path of the rays. Character selection.-Figs. 1-3 illustrate three ways of setting out character masks 2 on a carrier leaving a radiation-permeable area 3 which is in the path of the radiation beam 4 when the carrier is in the neutral position. In Fig. 4, an array 12 consists of eight carriers of the type shown in Fig. 1, one behind the other. The carriers are numbered 111-118 and comprise respectively brackets 111a-118a, each in the form of a rectangular framework. The brackets increase in length with their order from the front of the array so that the flange, or slot or the like on each of the cross-pieces 111b-118b may engage with its respective displacement means, without obstruction by the other brackets. Return springs 14, 14<SP>1</SP> in the form of steel wires, serve to return a carrier from the position against a stop 13 or 13<SP>1</SP> when the displacement means becomes inoperative, and also serve to prevent an unselected mask carrier being frictionally entrained by a selected one. Fig. 5 illustrates an alternative arrangement in which the brackets are of equal length, but the crosspieces, e.g. 111c, are positioned at a different position for each bracket. In Fig. 6, an array of twelve mask carriers 111-122 of the type shown in Fig. 3 is accommodated in a protective housing 12. Assuming that it is desired to select with a keyboard the mask bearing the capital letter " K," which mask is located on carrier 111, Fig. 11 a selecting magnet 411, Figs. 7 and 8, is energized and moves the carrier displacement means in the form of a coupling spring or wire 211, to withdraw a corrugation 211c of the wire from a notch 24a in a fixed bracket 24 and to bring a corrugation 211b into engagement with a notch 25a of a setting band 25. The wire 211 is now operatively connected to the setting band 25, and movement of the setting band under the action of a setting magnet 30 is transmitted by the wire 211 to the carrier 111. After a predetermined delay, the magnets 22, Fig. 6, of vertical displacement means, are energized and a pin 19a is moved upwardly into engagement with the lower edge of the displaced carrier 111. (In the neutral position, the pin 19a would move into a slot 111g.) If character " B " were selected, movement of carrier 111 would have to be terminated before it comes on to its stop 16. To this end, the setting band 25 has a slot 33, Fig. 10a, into which there normally projects a narrow diameter part 35b of the armature 35a of a limiting magnet 35. To select character " B," the magnet 35 is energized whereby the widened part of 35c enters the slot and abuts edge 33a<SP>1</SP> when the mask bearing the character " B " is in the path of the beam 4. The typewriter keyboard comprises switches s1-s48 arranged in four even groups SI-SIV, Fig. 12. Switches having the same order in their groups have their static contacts connected together and to one of the selecting magnets 411-422. The setting magnets 30 and 30<SP>1</SP> and limiting magnet 35 are connected via release switches 61, 62 and 63 and OR gates 55, 56 and 57, to the movable contacts of the groups as shown. If, for example, one of the switches is closed in groups SI or SII, setting magnet 30 is energized and setting band 25 is moved towards the left in Fig. 8. For groups SIII and SIV, the setting band 25 is moved to the right. Limiting magnet 35 is energized when a switch of groups SII or SIII is closed. Switch 64 is associated with the shift key, and energizes vertical shift magnets 22 when closed. Known time delay means (not illustrated) are incorporated in the circuits of the shift magnets 22 and the release switches 61, 63 and 62. In a modified circuit. Fig. 14, a feed barrier is provided which becomes effective when two keys are depressed at the same time. In addition a three-stage memory circuit is provided. If three characters are present in the memory, further feeding of a character is prevented by a memory lock until the first fed character has been removed from the memory.