Tricolor LED display system having audio output

• US 6,683,590 B1
• Filed: 11/10/2000
• Issued: 01/27/2004
• Est. Priority Date: 03/20/1998
• Status: Expired due to Term

• Current Assignee: City University of Hong Kong, Versitech Limited (Government of Hong Kong Special Administrative Region)
• Original Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Inventors: Yang, Edward S., Pang, Grantham Kwok-Hung, Kwan, To-On, Ho, Ka-Lim, Chan, Chi-Ho
• Primary Examiner(s): Liang, Regina
• Application Number:
  US09/646,649
• Time in Patent Office: 1,173 Days
• Field of Search: 345/82, 345/83, 345/39, 345/84, 348/801, 348/802, 340/901-903, 340/905, 340/906, 340/815.4, 340/815.45, 340/815.53
• US Class Current: 345/82
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2352/00 Parallel handling of streams of display data
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: H04B 10/1141 One-way transmission
• CPC Class Codes: H04B 10/116 Visible light communication

Abstract

A tricolor LED display system (10) is provided having a plurality of multi-color LEDs (22) that operate as concurrent display and data communication elements. These dual-use tricolor LEDs are coupled to a special-purpose computer system (12) and audio signal transmitter (16) for simultaneously controlling the visible display signal from the LEDs, and for modulating audio information onto the visible light signal emitted by the LEDs. A receiver circuit (24) receives the modulated visible light signal from the LEDs and demodulates the received signal to recover the audio information, which is then presented to a user of the system through an audio interface.

Claims

1. A tricolor LED display system, comprising:

a transmitter sub-system for simultaneously transmitting visible display signals and modulated visible light signals through a tricolor LED display, wherein the modulated visible light signals carry modulated audio information; and

a receiver sub-system for receiving the modulated visible light signals and for demodulating the visible light signals to recover the transmitted audio information.

2. The system of claim 1, wherein the tricolor LED display is capable of displaying red, green and amber colors.

3. The system of claim 1, wherein the receiver sub-system includes:

an optical sensor for receiving the modulated visible light signal from the tricolor LED display;

a demodulator coupled to the optical sensor for demodulating the modulated visible light signal to recover the transmitted audio signal; and

a speaker coup led to the audio signal.

4. The system of claim 3, wherein the receiver sub-system further includes a lens for focusing light emitted by the tricolor LED display onto the optical sensor.

5. The system of claim 3, wherein the optical sensor is a photo-detector.

6. A tricolor LED display system, comprising:

a transmitter sub-system for simultaneously transmitting visible display signals and modulated visible light signals through a tricolor LED display, wherein the modulated visible light signals carry modulated audio information; and

a receiver sub-system for receiving the modulated visible light signals and for demodulating the visible light signals to recover the transmitted audio information;

the transmitter sub-system including;

a computer system for generating display information;

an audio signal transmitter for generating a modulated audio signal; and

an interface circuit coupled to the computer system and the audio signal transmitter for applying the display information and the modulated audio signal to the tricolor LED display.

7. The system of claim 6, wherein the computer system is coupled to the interface circuit through a parallel port interface.

8. The system of claim 6, further including an executive computer program operating on the computer system for controlling the generation of display information.

9. The system of claim 6, wherein the audio signal transmitter includes:

a source of audio information for generating an audio signal; and

a modulator coupled to the source of audio information for generating the modulated audio signal.

10. The system of claim 9, wherein the modulator is a voltage controlled oscillator.

11. The system of claim 10, wherein the voltage-controlled oscillator operates as a frequency modulator.

12. The system of claim 6, wherein the interface circuit includes:

a row counter decode system coupled to the modulated audio signal for controlling the row selection of the LEDs in the tricolor LED display; and

a segment counter decode system coupled to the display information for controlling the segment selection of the LEDs in the tricolor LED display.

13. The system of claim 12, herein the interface circuit further includes:

a parallel port interface for receiving the display information, the display information including display data and addressing information for the LED display;

an address comparison unit for comparing the addressing information for the LED display with system addressing information generated by the row counter decode system and the segment counter decode system; and

a pattern storage system for storing the display data when the address comparison unit indicates that the addressing information for the LED display is the same as the addressing information generated by the row counter decode system and the segment counter decode system.

14. The system of claim 13, wherein the interface circuit further includes:

a status indicator coupled to the parallel port interface for generating a write complete signal to the computer system when the display data is written to the pattern storage system.

15. A tricolor LED display system, comprising:

a tricolor LED dot matrix display having a plurality of tricolor LEDs;

means for applying a display signal to the tricolor LEDs to generate a visible signal pattern; and

means for applying an audio signal to the tricolor LEDs to emit a modulated visible light signal that carries the audio signal.

16. An interface circuit for controlling a tricolor LED display, comprising:

a row counter decode system coupled to a frequency-modulated audio signal for controlling the row selection of the LEDs in the tricolor LED display; and

a segment counter decode system coupled to display information for controlling the segment selection of the LEDs in the tricolor LED display.

17. An interface circuit for controlling a tricolor LED display, comprising:

a row counter decode system coupled to a modulated audio signal for controlling the row selection of the LEDs in the tricolor LED display;

a segment counter decode system coupled to display information for controlling the segment selection of the LEDs in the tricolor LED display;

a parallel port interface for receiving the display information, the display information including display data and addressing information for the LED display;

an address comparison unit for comparing the addressing information for the LED display with system addressing information generated by the row counter decode system and the segment counter decode system; and

a pattern storage system for storing the display data when the address comparison unit indicates that the addressing information for the LED display is the same as the addressing information generated by the row counter decode system and the segment counter decode system.