Browse Prior Art Database

Multicolor Roled Displays

IP.com Disclosure Number: IPCOM000088339D
Original Publication Date: 1977-May-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Levine, J: AUTHOR

Abstract

In a rotating optical light-emitting diode (ROLED) display, a single line of light-emitting diodes (LEDs) is multiplexed by a rotating optical scanner. A multicolored display can be obtained by incorporating additional lines of LEDs of various colors. The major difficulties are obtaining proper registration of the different images and avoiding a proliferation of connections and drivers. The mounting arrangement of Fig. 1 solves both these problems.

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Multicolor Roled Displays

In a rotating optical light-emitting diode (ROLED) display, a single line of light-emitting diodes (LEDs) is multiplexed by a rotating optical scanner. A multicolored display can be obtained by incorporating additional lines of LEDs of various colors. The major difficulties are obtaining proper registration of the different images and avoiding a proliferation of connections and drivers. The mounting arrangement of Fig. 1 solves both these problems.

Fig. 1 shows, for example, three lines of LEDs (red, yellow and green). The LEDs of each color share a common connection (either cathode or anode). In addition, each vertical group of three shares a connection (e.g., a wire bond). Thus, an arbitrary pattern of LEDs may be pulsed, one color at a time. Good registration of the final images will be automatic if the LEDs are properly located during production.

Two methods of use are possible. If a low duty cycle is acceptable, different colors may be displayed during different scans, persistence of vision serving to fuse the various colors into a single image. In this case, the vertical spacing of the different LED lines is not critical provided that the lines are parallel. The images of the different colors, displaced by the vertical spacing, are easily brought into registration by introducing a time delay for each color such that the scanner advances sufficiently to displace the image field by the vertical spacing.

If instead it is desired to ch...