公开(公告)号：US3039005A

公开(公告)日：1962-06-12

申请号：US2101660

申请日：1960-04-08

Applicant: IBM

Inventor： O'CONNELL JAMES A ,  BERNT NARKEN

IPC: G02F1/00 ,  G09G3/02 ,  H03K17/78 ,  H05B33/12

CPC classification number: H05B33/12 ,  G02F1/00 ,  G09G3/02 ,  G09G3/30 ,  G09G2360/141 ,  H03K17/78

公开(公告)号：US2981858A

公开(公告)日：1961-04-25

申请号：US82859959

申请日：1959-07-21

Applicant: IBM

Inventor： O'CONNELL JAMES A

IPC: G09F13/22 ,  H05B33/20

CPC classification number: H05B33/20 ,  C08K3/02 ,  C08K3/30 ,  C09J7/38 ,  C09J9/00 ,  C09J2205/102 ,  G09F13/22

公开(公告)号：DE1139545B

公开(公告)日：1962-11-15

申请号：DEJ0019709

申请日：1961-04-07

Applicant: IBM

Inventor： O'CONNELL JAMES A ,  NARKEN BERNT

IPC: G02F1/00 ,  G09G3/02 ,  H03K17/78 ,  H05B33/12

Abstract: In an electro-optical device, Fig. 1, comprising a photo-conductive element 11 in series with light source 13 and an A.C. power supply 12, the light source being optically coupled to the photo-conductor whereby the device may be triggered on by a short duration light pulse from a separate source 15 and remains triggered on due to the optical feed-back between 11 and 13, the photo-conductive element is arranged to exhibit current undershoot (see Journal of Physics and Chemistry of Solids, Vol. 1, No. 4, 1957, pages 234-248), whereby, in response to the termination of a subsequent light pulse equal to or greater than a predetermined intensity and duration from source 15, the resistivity becomes for a time greater than normal and causes light source 13 to extinguish and the device to trigger off. As illustrated, the light source comprises an electroluminescent element. In another embodiment, Figs. 7 and 8 (not shown), a neon tube is used. A display panel, Fig. 3, may be made of an array of devices as shown in Fig. 1 by forming between glass plates 32, 33 and transparent conductive layers 31, 34 an electroluminescent layer 35 bearing individual photo-conductive elements 30. A picture is set up by scanning the panel by an appropriately controlled flying-spot scanner 39 and any changes necessary in the picture are effected by illuminating areas to be darkened by a slow scan. Alternatively, the entire display may be blanked by unfocused illumination of long duration or a high intensity scan and then a further picture imparted by a low intensity scan. Photo-conductive material said to exhibit the current undershoot phenomenon to a sufficient pronounced extent comprises cadmium selenide with copper and silver acceptor atoms and chlorine donor atoms. In another form of device, Fig. 4, the photo-conductive element 41 is shunted by a normal resistive element 42 chosen so that the potential distribution in the circuit is such that the device is normally "on" with light source 44 (an electroluminescent element) producing light. If light from a separate source 46 of sufficient intensity is now impinged on element 41 for a sufficient period and subsequently extinguished, the resulting rise in resistance above normal, due to current undershoot, extinguishes source 44 and triggers the device off. The device persists off only momentarily, for the photo-conductive element reverts towards its normal resistance and once again allows source 44 to come on. A device as described in connection with Fig. 4 may be constructed as shown in Fig. 6 by forming on a glass plate 61 in successive layers: a transparent tin oxide electrode 62, an electroluminescent element 63, an insulator 64, a photo-conductive element 66 and a resistive element 67 formed of tin oxide. A hole 65 in insulator 64 allows a common connection to be established between elements 63, 66 and 67.