A variable color optical device comprises three light emitting diodes for emitting upon activation light signals of respectively different primary colors and means for blending the light signals to obtain a composite light signal of a composite color. The light emitting diodes are substantially simulteneously activated by pulses of a substantially constant amplitude. Color control selectively controls the durations of the pulses to control the portions of the primary colors, to thereby control the color of the composite light signal emitted from the optical device.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a division of my copending application Ser. No. 06/922,847, filed on Oct. 24, 1986, entitled Continuously Variable Color Display Device now U.S. Pat. No. 4,845,481, which is a division of my application Ser. No. 06/817,114, filed on Jan. 8, 1986, entitled Variable Color Digital Timepiece, now U.S. Pat. No. 4,647,217 issued on Mar. 3, 1987.
Reference is also made to my applications Ser. No. 06/839,626, filed on Mar. 14, 1986, entitled Variable Color Display Typewriter, now abandoned, and Ser. No. 06/819,111, filed on Jan. 15, 1986, entitled Variable Color Digital Multimeter, now U.S. Pat. No. 4,794,383 issued on Dec. 27, 1988.
A high efficiency light emitting diode (LED) driving circuit includes a first LED coupled in a forward current path between first and second nodes and a second LED being coupled in a reverse current path between the second and first nodes. A power supply is drives the first node with voltage pulses. A capacitor is coupled to the second node and stores charge while the power supply is driving the first LED in the forward current path during voltage pulses. A discharge circuit drains charge from the capacitor to drive the second LED in the reverse current path between voltage pulses.
Apparatus for color correcting a display module is disclosed. The display module includes a plurality of light emitting elements such as LEDs. The LEDs typically include sources of nominally red, green and blue colors. The apparatus includes a device for activating a light emitting element to emit an uncorrected first color and a device for activating at least one further light emitting element which emits a color other than the first color, to produce a corrected first color. An array of corrected display modules and a method of correcting a color in a display module are also disclosed.
A color display device in which a plurality of units are arranged in a matrix, each unit having collectively disposed three light emission diodes of three colors, for example, red, yellowish green, and blue, and in which emission intensity and a luminous color of each light emission diode can be controlled by supplying each light emission diode with a time series electric pulse while varying its intensity and width. In the device according to the present invention, the electrodes are provided collectively on one side of the flexible insulator substrate and multilayer wiring is formed by evaporation or plating on the substrate so that the device has an advantage which could not obtained in the conventional display devices in that the display portion thereof can be rolled.
The present invention provides a parallel pulse code modulation system enabling the independent control of a plurality of groups of one or more electronic devices. A memory unit receives control data from an external source, and a multiplexer connected to the memory unit receives control data therefrom and organizes it into a serial data stream. A shift register connected to the multiplexer receives the serial data stream and translates groups of data into parallel data stream output, representing control parameters for a particular group of one or more electronic devices. A latch connected to the shift register and to the groups of electronic devices receives each parallel data stream output and sends a particular parallel data stream output to a corresponding group electronic devices. A logic sequencer provides sequencing and timing signals to the memory unit, the multiplexer, the shift register and the latch.
The invention provides a system of generation of multi-channel analog output signals, from a single analog input signal, and the controlled activation of peripheral devices responsive to the multi-channel analog output signals. A single-channel to multi-channel analog-to-analog converter is provided to convert the single analog input signal to multiple output channels. Uni-directional coupling is used for coupling and mixing the multi-channel outputs and transferring the mixed outputs to a data buss. Signals on the data buss are used to drive the multiple peripheral devices.
