TitleScriptel Digitizing Tablet
|Other number||894 2285||Verso|
Dimensionsoverall: 8 x 10
DescriptionB&W image of two Scriptel digitizing tablets along with a pen and scanning tool.
Metadata supplied with image: " Transparent Digitizing tablet Scriptel Corp 1984 The Computer Museum
A transparent tablet allows original artwork or photographs to be placed underneath the tablet, protected from scratching or staining. The tablet can be mounted onto a flat display screen enabling- video images to be digitized. With a frosted glass finish, a slide could be back projected onto the tablet for digitizing. A major application is the digitization of medical images, particularily x-rays. The rear of the glass tablet is coated with a continous layer of resistive material, Indium oxide. One edge of the tablet is grounded while an AC voltage is applied to the opposite edge. the puck contains a receivcer which produces a signal through capacitative coupling when placed on the tablet. The strength of the signal yields the coordinate along one axis which is checked by reversing the ground and live edges. The proces is repeated for the complementary pair of edges, yielding the second coordinate. 150 coordinate pair measurements are made per second."