Continuously variable color optical device

• US 4,965,561 A
• Filed: 03/13/1989
• Issued: 10/23/1990
• Est. Priority Date: 01/08/1986
• Status: Expired due to Term

• Current Assignee: Texas Digital Systems, Inc. (NCR Voyix Corporation)
• Original Assignee: Karel Havel
• Inventors: Havel, Karel
• Primary Examiner(s): Oberley, Alvin E.
• Assistant Examiner(s): HJERPE, RICHARD A
• Application Number:
  US07/322,341
• Time in Patent Office: 589 Days
• Field of Search: 340/701, 340/702, 340/703, 340/762, 340/756, 340/782, 340/793, 340/767, 340/815.03, 340/815.04, 340/815.1
• US Class Current: 345/46
• CPC Class Codes: G04G 21/025 for measuring physiological data
• CPC Class Codes: G04G 9/12 using light valves, e.g. liquid crystals

Abstract

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.

Claims

1. A method of controlling a color of a variable color optical device which comprises a plurality of light sources for emitting upon activation light signals of respectively different primary colors and means for combining said light signals to obtain a composite light signal of a composite color, by repeatedly substantially simultaneously activating said light sources for brief time intervals by pulses of a substantially constant amplitude to cause them to emit light signals of said primary colors, and by selectively controlling durations of the time intervals of activation of respective light sources to control the portions of said primary colors, to thereby control the color of said composite light signal.

2. A variable color optical device comprising:

a plurality of light sources for emitting upon activation light signals of respectively different primary colors and means for combining said light signals to obtain a composite light signal of a composite color;

means for repeatedly activating said light sources by substantially simultaneously applying thereto pulses of a substantially constant amplitude for causing said light sources to emit light signals of said primary colors; and

color control means for selectively controlling durations of the pulses applied to respective light sources to control the portions of said primary colors, to thereby control the color of said composite light signal.

3. A method of controlling a color of a variable color optical device which comprises a plurality of light emitting diodes for emitting when forwardly biased light signals of respectively different primary colors and means for combining said light signals to obtain a composite light signal of a composite color, by repeatedly substantially simultaneously forwardly biasing said light emitting diodes by pulses of a substantially constant amplitude to cause them to emit light signals of said primary colors, and by selectively controlling durations of the pulses to control the time intervals of forward biasing of respective light emitting diodes, to control the portions of said primary colors, to thereby control the color of said composite light signal.

4. A variable color optical device comprising:

a plurality of light emitting diodes for emitting when forwardly biased light signals of respectively different primary colors and means for combining said light signals to obtain a composite light signal of a composite color;

means for repeatedly forwardly biasing said light emitting diodes by substantially simultaneously applying thereto pulses of a substantially constant amplitude for causing said light emitting diodes to emit light signals of said primary colors; and

color control means for selectively controlling durations of the pulses applied to respective light emitting diodes to control the portions of said primary colors, to thereby control the color of said composite light signal.

5. An optical device comprising:

a first light emitting diode for emitting when forwardly biased light signals of a first color;

a second light emitting diode for emitting when forwardly biased light signals of a second color;

a third light emitting diode for emitting when forwardly biased light signals of a third color;

means for combining light signals emitted by said first light emitting diode, by said second light emitting diode, and by said third light emitting diode to obtain a composite light signal of a composite color;

first means for repeatedly applying to said first light emitting diode pulses of a uniform amplitude for forwardly biasing it to emit light signals of said first color;

first means for selectively controlling durations of the pulses applied to said first light emitting diode to control the portion of said first color;

second means for repeatedly applying to said second light emitting diode pulses of a uniform amplitude for forwardly biasing it to emit light signals of said second color;

second means for selectively controlling durations of the pulses applied to said second light emitting diode to control the portion of said second color;

third means for repeatedly applying to said third light emitting diode pulses of a uniform amplitude for forwardly biasing it to emit light signals of said third color; and

third means for selectively controlling durations of the pulses applied to said third light emitting diode to control the portion of said third color.

6. An optical device comprising:

a first light emitting diode for emitting when forwardly biased light signals of a first color;

a second light emitting diode for emitting when forwardly biased light signals of a second color;

a third light emitting diode for emitting when forwardly biased light signals of a third color;

means for combating light signals emitted by said first light emitting diode, by said second light emitting diode, and by said third light emitting diode to obtain a composite light signal of a composite color;

clock means for sequentially producing clock pulses;

a cycle counter responsive to said clock pulses for sequentially producing a timing signal;

first memory means for storing data representing a portion of said first color, said first memory means having a first memory output indicative of the values of the stored data;

a first counter responsive to said timing signal and to said first memory output, for extracting in accordance with the timing signal from said first memory means the value of the data and loading it as its counter contents, and to said clock pulses, for incrementing in accordance with said clock pulses its counter contents, said first counter having a first counter output for developing a first counter signal indicative when its counter contents reaches zero;

a first flip-flop responsive to said timing signal, for being set to its first condition when said timing signal occurs, and to said first counter signal, for being set to its second condition when said first counter signal occurs, said first flip-flop having an output indicative of its condition, said output being coupled to said first light emitting diode for forwardly biasing it while said first flip-flop is in its first condition;

second memory means for storing data representing a portion of said second color, said second memory means having a second memory output indicative of the values of the stored data;

a second counter responsive to said timing signal and to said second memory output, for extracting in accordance with the timing signal from said second memory means the value of the data and loading it as its counter contents, and to said clock pulses, for decrementing in accordance with said clock pulses its counter contents, said second counter having a second counter output for developing a second counter signal indicative when its counter contents reaches zero;

a second flip-flop responsive to said timing signal, for being set to its first condition when said timing signal occurs, and to said second counter signal, for being set to its second condition when said second counter signal occurs, said second flip-flop having an output indicative of its condition, said output being coupled to said second light emitting diode for forwardly biasing it while said second flip-flop is in its first condition;

third memory means for storing data representing a portion of said third color, said third memory means having a third memory output indicative of the values of the stored data;

a third counter responsive to said timing signal and to said third memory output, for extracting in accordance with the timing signal from said third memory means the value of the data and loading it as its counter contents, and to said clock pulses, for decrementing in accordance with said clock pulses its counter contents, said third counter having a third counter output for developing a third counter signal indicative when its counter contents reaches zero; and

a third flip-flop responsive to said timing signal, for being set to its first condition when said timing signal occurs, and to said third counter signal, for being set to its second condition when said third counter signal occurs, said third flip-flop having an output indicative of its condition, said output being coupled to said third light emitting diode for forwardly biasing it while said third flip-flop is in its first condition.