Optical transmitter and transceiver module for wireless data transmission

• US 6,424,442 B1
• Filed: 02/25/1997
• Issued: 07/23/2002
• Est. Priority Date: 09/03/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Richard, Heinz, Weiss, Beat, Gfeller, Fritz
• Primary Examiner(s): Chan, Jason
• Assistant Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US08/793,994
• Time in Patent Office: 1,974 Days
• Field of Search: 359/142, 359/152, 359/159, 359/163, 359/180, 362/240, 362/242, 362/243, 362/246, 362/252, 362/282, 362/800
• US Class Current: 398/135
• CPC Class Codes: H04B 10/1143 Bidirectional transmission
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

Disclosed are optical transmitter and transceiver modules for data communication. Such a transceiver module comprises an array of light emitting diodes mounted on a mounting base (140) being arranged in a regular and symmetrical manner in a dome-shaped housing (142). This housing (142) comprises diffusor means for source enlargement. In addition to the transmitter part consisting of said diodes, the transceiver module comprises a receiver. The receiver has four photodiodes (143) arranged below the mounting base (140). These photodiodes are tilted and face in different directions to receive light from all around the module. The photodiodes are protected by a thin wire mesh (145) which serves as Faraday cage to reduce electro magnetic interference. A substrate (144) for electronic circuitry in SMD-Technology is situated underneath the photodiodes (143).

Claims

1. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable;

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor; and

a phase hologram located inside the housing,

wherein said array is situated within said cavity such that infra-red light is emitted from said array inside said cavity through said phase hologram acting as a beam shaper and through said diffusor providing for an apparent source enlargement.

2. The module of claim 1, wherein the light emitting diodes of said array are located on a mounting base such that the main radiation axis of the diodes is approximately parallel to the center axis of said dome-shaped housing.

3. The module of claim 1, wherein the light emitting diodes of said array are located on a mounting base such that the main radiation axis of the diodes is tilted with respect to the center axis of said dome-shaped housing.

4. The module of claim 3, wherein the light emitting diodes are arranged such that they face towards said center axis.

5. The module of claim 3, wherein the light emitting diodes are arranged such that they face radially outwards with respect to said center axis.

13. The module of any one of the claims 1, 6, 7, 9, 10, 11, and 12, wherein said array of infra-red light emitting diodes are further arranged in a symmetrical manner.

17. The module of any one of the claims 1, 6, 7, 9, 10, 15, 11, 16 and 12, further comprising a receiver with an array of photodiodes being tilted with respect to said center axis of the housing.

18. The module of claim 17, wherein said photodiodes are located below said array of light emitting diodes in the same housing.

19. The module of claim 17, wherein said photodiodes are located above said array of light emitting diodes in the same housing.

20. The module of claim 17, wherein said photodiodes are mounted on a mounting base which is fixed in said housing.

21. The module of claim 17, wherein said housing further comprises a substrate with electronic circuitry and/or a thin wire mesh.

22. The module of any one of the claims 1, 6, 7, 9, 10, 15, 11, 16 and 12, wherein said optical data module is coupled to

a computer, having a bus, through a bus interface.

23. The module of claim 22, wherein said optical data module is attached to a display panel of the computer by a clip connected to said interface via a cable.

24. The module of claim 22, wherein said optical data module is integrated in a fixed or retractable manner into the display panel of the computer.

6. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable; and

a dome-shaped housing forming a cavity said dome-shaped housing having a diffusor formed by suspending particles of high refractive index within said dome-shaped housing,

wherein said array is situated within said cavity such that infra-red light is emitted from said array inside said cavity through said diffusor providing for an apparent source enlargement.

7. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable; and

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor formed by one or more corrugated surfaces situated at the inner and/or outer surface of said dome-shaped housing.

8. The module of claim 7, wherein said corrugated surface has a degree of roughness which matches the wavelength emitted by the light emitting diodes of the module.

9. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable; and

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor formed by one or more checkerboard pattern at the inner and/or outer surface of said dome-shaped housing.

10. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable;

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor; and

a prism ring cooperating with said dome-shaped housing,

wherein said array is situated within said cavity such that part of the infra-red light emitted from said array inside said cavity passes through said diffusor providing for an apparent source enlargement while part of the light (Δ

) emitted by said array of light emitting diodes passes through said prism ring deflecting the light downwards such that direct line-of-sight communication is improved.

11. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable;

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor; and

a series of reflectors, or a series of prisms located in a circular manner in said dome-shaped housing,

wherein said array is situated within said cavity such that infra-red light is directly emitted, reflected, or deflected from said array inside said cavity through a first portion of said housing operating as a diffusor, providing a corresponding first radiation pattern, or through a second portion of said housing, providing a corresponding second radiation pattern, such that, depending on the position of said array of light emitting diodes with respect to said reflectors or prisms, the radiation pattern of said module can be switched.

12. The module of claim 11, wherein said dome-shaped housing is stepwise rotatable with respect to said array of light emitting diodes.

14. The module of claim 11, wherein said second portion of said housing operates as a diffusor providing a corresponding modified second radiation pattern.

15. An optical data module comprising:

an array of infra-red light emitting diodes arranged in a regular manner and being individually and/or commonly addressable;

a dome-shaped housing forming a cavity, said dome-shaped housing having a diffusor; and

a series of reflectors, upward facing deflector prisms, and downward facing deflector prisms located in a circular manner at the inner surface of the housing,

wherein said array is situated within said cavity such that infra-red light is directly emitted or is reflected from said array inside said cavity through said diffusor, providing for a an apparent source enlargement, or through said upward or downward facing deflector prisms, providing for a corresponding upward or downward directional radiation pattern, such that, depending on the position of said array of light emitting diodes with respect to said reflectors and deflector prisms, the radiation pattern of said module can be switched.

16. The module of claim 15, wherein said dome-shaped housing is stepwise rotatable with respect to said array of light emitting diodes.

25. A Transceiver for wireless data communication and for use in connection with a optical transmitter module having a dome-shaped housing forming a cavity having a diffusor means, an array of infra-red light emitting diodes being arranged in a regular manner and being either individually or commonly addressable, said array situated within said cavity, wherein said infra-red light is emitted from said array inside said cavity through said diffusor means providing for an apparent source enlargement, said transceiver comprising:

a) an array of photodiodes,

b) amplifiers for amplification of the signals received by said array of photodiodes,

c) means for detecting the information carried in the signals received by said array of photodiodes,

d) driver means for driving the array of infra-red light emitting diodes of said optical transmitter module,

e) means for active selection and individual combination of the signals received by each of the photodiodes of said array of photodiodes,

f) means for proximity detection by determining the strength of an echo signal and switching off the array of infra-red light emitting diodes of said optical transmitter module if said echo signal exceeds a predefined limit.

26. A Transceiver for wireless data communication and for use in connection with a optical transmitter module having a dome-shaped housing forming a cavity having a diffusor means, an array of infra-red light emitting diodes being arranged in a regular manner and being either individually or commonly addressable, said array situated within said cavity, wherein said infra-red light is emitted from said array inside said cavity through said diffusor means providing for an apparent source enlargement, and with a receiver with an array of photodiodes being tilted with respect to said center axis of the housing, said transceiver comprising:

a) amplifiers for amplification of the signals received by the array of photodiodes of said module,

b) means for detecting the information carried in the signals received by the array of photodiodes of said module,

c) driver means for driving the array of infra-red light emitting diodes of said module,

d) means for active selection and individual combination of the signals received by each of the photodiodes of the array of photodiodes of said module,

e) means for proximity detection by determining the strength of an echo signal and switching off the array of infra-red light emitting diodes of said module if said echo signals exceeds a predefined limit.

27. A computer system comprising:

a computer having a bus;

an optical transmitter module having a dome-shaped housing forming a cavity having a diffusor means, an array of infra-red light emitting diodes being arranged in a regular manner and being either individually or commonly addressable, said array situated within said cavity, wherein said infra-red light is emitted from said array inside said cavity through said diffusor means providing for an apparent source enlargement, an interface means for coupling said optical transmitter module to the bus of said computer; and

an optical transceiver having an array of photodiodes, amplifiers for amplification of the signals received by said array of photodiodes, means for detecting the information carried in the signals received by said array of photodiodes, driver means for driving the array of infra-red light emitting diodes of said optical transmitter module, means for active selection and individual combination of the signals received by each of the photodiodes of said array of photodiodes, means for proximity detection by determining the strength of an echo signal and switching off the array of infra-red light emitting diodes of said optical transmitter module if said echo signal exceeds a predefined limit, an interface means for coupling said optical transceiver module to the bus of said computer.

28. A computer system comprising:

a computer having a bus;

an optical transmitter module having a dome-shaped housing forming a cavity having a diffusor means, an array of infra-red light emitting diodes being arranged in a regular manner and being either individually or commonly addressable, said array situated within said cavity, wherein said infra-red light is emitted from said array inside said cavity through said diffusor means providing for an apparent source enlargement, and with a receiver with an array of photodiodes being tilted with respect to said center axis of the housing, and an interface means for coupling said optical transmitter module to the bus of said computer; and

,

an optical transceiver having amplifiers for amplification of the signals received by the array of photodiodes of said module, means for detecting the information carried in the signals received by the array of photodiodes of said module, driver means for driving the array of infra-red light emitting diodes of said module, means for active selection and individual combination of the signals received by each of the photodiodes of the array of photodiodes of said module, means for proximity detection by determining the strength of an echo signal and switching off the array of infra-red light emitting diodes of said module if said echo signals exceeds a predefined limit, and an interface means for coupling said optical transmitter module to the bus of said computer.