| 摘要 |
<p>1325678 Data retrieval apparatus PLESSEY CO Ltd 15 Oct 1970 [21 Oct 1969] 51507/69 Heading G4H Apparatus for retrieving data stored on the frames of microfilm comprises a keyboard 20 for inserting in registers 30 and 32 binary representations of the first and second letters respectively of the name of the selected data and comparators 88, 90 for comparing the binary coded letters with the outputs a-j of a frame counter 54 so that the microfilm is stopped when the selected data is positioned at a viewing screen 18. The data may be lists of pharmaceuticals and each frame stores those pharmaceuticals having common first and second letters for their names. Each letter of the alphabet is assigned a decimal number and when the keys corresponding to the first and second letters of the selected name are depressed successively, the registers 30, 32 store the binary representations of the decimal numbers assigned to the selected letters. The depression of the second key energizes the microfilm drive motor via a lead 12 and a lead 14 supplies one pulse to the counter 54 for each frame that passes the viewing position. When each of the comparators 88A-88F and 90A- 90D have equal inputs a signal is provided on each of lines 92, 94 connected to an "AND" gate 96 the output of which energizes a line 16 to stop the drive motor.</p> |
