|Burroughs SD-11 Sphericular Display||
|Written by AnubisTTP on 2008-03-19
At first glance, the Burroughs SD-11 may appear to be a standard projection display, but it is in fact a sphericular display. The SD-11 operates in a similar manner to a lenticular device, but instead of being composed of bar-shaped elements, it is composed of a grid of circular elements. The front panel of the SD-11 is a complex two-dimensional array of faceted refractors which generate the displayed digit; there are no lenses or digit masks as in a standard projection display. The angle of the light striking the refractor controls which digit is displayed, by applying power to one of eleven bulbs inside the device. The digits zero through nine can be displayed with or without decimal point. Eliminating the bulky lenses used in projection displays allows for the manufacture of a display that is a fraction of the size of competing devices. The displayed characters on the SD-11 are not as clear as those displayed by most projection displays, but the visual appearance of the sphericular characters is quite distinctive.
Burroughs SD-11 specular optical display.
SD-11 disassembled, showing lamps and contacts.
The SD-11, which requires no lenses or digit masks, is much smaller than the average projection display.
Due to the way the SD-11 works, its appearance is noticeably improved by replacing the bulbs with LEDs. Narrow beam LEDs produce clearer numbers because they produce less backscatter that can strike unwanted pixels.
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