Frequency-alternating synchronized infrared

• US 5,682,157 A
• Filed: 10/19/1992
• Issued: 10/28/1997
• Est. Priority Date: 10/19/1992
• Status: Expired due to Term

• Current Assignee: Fasirand Corporation
• Original Assignee: Fasirand Corporation
• Inventors: Dillon, Thomas P., Asmussen, Daniel R., Shride, Michael D., Sloate, James A.
• Primary Examiner(s): Young, Brian K.
• Application Number:
  US07/962,746
• Time in Patent Office: 1,835 Days
• Field of Search: 341/68, 341/70, 341/13, 341/69, 341/50
• US Class Current: 341/68
• CPC Class Codes: H03M 5/04 the pulses having two levels
• CPC Class Codes: H03M 5/12 Biphase level code, e.g. split phase code, Manchester code; Biphase space or mark code, e.g. double frequency code
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence

Abstract

Disclosed is a system for rapid, wireless communication of electrically-generated and detected, serial digital data signals via a plurality of infrared (or other compatible wireless medium) transceivers. Signals are communicated without electrical connection among computers, fax machines, computer peripheral equipment, or may be employed within self-contained communication, control data-acquisition, and/or display systems. The system operates at predetermined maximum data rates and sub-multiples thereof. The disclosed transceivers can be joined with additional circuits, to form an arrangement that operates as a wireless modem. In each arrangement, light is continuously modulated at either of two precise multiples of the predetermined maximum data rate, and is synchronized to transmitted-data transitions. Upon receipt of light-signals thus produced, the system'"'"'s receiving transceiver synchronizes received-data electrical output signals to the received modulated light signals. Received light-modulation periods are measured and verified continuously within each data-state interval, minimizing data-delay times and transition-timing distortions in the system'"'"'s electrical output signals.

Claims

1. A signal transformation means for conversion of electrical, separately-generated serial binary information signals from an original sequential signal form having binary state transitions that can occur only at predictable intervals, and having a highest-permissible data transitions-rate, to a second sequential signal form suitable for transmission over a distance via light path or other media as a continuous signal of a form that permit conversion again into the original signal form, or other useful signal form, said signal transformation means comprising in combination:

a) an electrical sensing means to determine sequential binary states of said separately-generated serial binary information signals;

b) a first timing means to determine binary state-intervals of said separately-generated serial binary information signals;

c) a second timing means to determine binary state-transitions of said separately-generated serial binary information signals;

d) a third timing means to form, concurrently with, and produced from, timing of binary state-transitions of said separately-generated serial binary information signals, binary states and transitions of said second sequential signal form, such that the second sequential signal form continuously alternates at one of two fundamental frequencies;

e) a control means, used to control said third timing means, to select between two fundamental frequencies of the second sequential signal form, each frequency corresponding to a separate logic state of the separately-generated serial binary information signals,

f) an electrical amplifying means to convert logic states of said second sequential signal form from low signal power levels to higher signal power levels suitable to operate and control intensity of a light transmitting source, or otherwise modulate any other suitable, second sequential signal transmission means;

g) a light, or other media, transmission means, suitable to transmit said second sequential signal form;

h) a second sensing means to convert light, or other suitable signal means, to electrical analog signals;

i) a second electrical amplifying means, suitable to increase electrical analog signals produced by said second sensing means to levels suitable for subsequent detection and timing measurement;

j) a signal-level comparison means to infinitely clip, and thereby convert, electrical analog signals produced by said second sensing means and increased by said second electrical amplifying means to binary signals;

k) a fourth timing means to determine binary state-transition times of like-polarity transitions of binary signals as produced by said signal-level comparison means, and to classify timed periods of said binary state-transition times within at least four predetermined ranges, classified as in-band high, in-band low, out-of-band high, and out-of-band low;

l) a fifth timing means to form, concurrently with, and produced from, binary state-transition times determined from the fourth timing means, a new, final sequential binary signal, which accurately duplicates binary states and transition-timing characteristics of the separately-generated serial binary information signals.

2. In a signal transformation means as described in claim 1, an improvement comprising an analog signal filtering means to limit signal-bandwidth content of analog signals produced by the second sensing means and increased by said second electrical amplifying means, in order to reduce influence of foreign light sources or other interfering signals that can otherwise disturb timing-accuracy determinations of the second sequential signal, as it is received.

3. In the signal transformation means according to claim 1, a binary signal-synchronizing means to cause states and state-transitions of said second sequential signal form to occur at times, relative to state-transitions of said separately-generated serial binary signals, which are predictable and of minimal delay.

4. In the signal transformation means according to claim 1, a binary signal-synchronizing means to cause states and state-transitions of the final sequential binary signal to occur at times, relative to binary state-transitions of said second sequential signal form, which are predictable and of minimal delay.

5. A signal transformation means as described in claim 1, wherein the second sequential signal form is comprised of a series of continuous pulses whose pulse-rates are altered by states of the separately-generated serial binary information signals.

6. A signal transformation means as described in claim 1, wherein state-transitions of the second sequential signal form are synchronized to state-transitions of said separately-generated serial binary information signals, and state-transitions of said final sequential binary signal are synchronized to state transitions of the second sequential signal form, such as to cause a summation of times required for transformation of the separately-generated serial binary signals to the final sequential binary signal to be predictable and of minimal delay.

7. A signal transformation means as described in claim 6, wherein the second sequential signal form is comprised of a series of continuous pulses whose pulse-rates are altered by states of the separately-generated serial binary information signals.

8. A signal transformation means as described in claim 5, wherein pulse intervals of the second sequential signal form are integer-multiples of minimum binary state transition intervals present in the separately-generated serial binary information signals, thereby providing multiple and continuous verifications of states of the separately-generated serial binary information signals.

9. A signal transformation means as described in claim 8, wherein a common synchronous logic time-base, derived from an external logic clock signal, is chosen to have a fundamental frequency which is a common multiple of two frequencies, comprising the second sequential signal form, which represent logic states of the separately-generated serial binary information signals.

10. In a signal transformation means as described in claim 6, an improvement comprising a timing and re-synchronizing means to delay by a fixed interval relative to state-transitions of said second sequential signal form, transitions of the final sequential binary signal to occur at times, wherein differences in pulse intervals of the second sequential signal received are precisely compensated such as to minimize transition timing errors of the final sequential binary signal which would otherwise occur.

11. A signal transformation means as described in claim 8, wherein frequencies of the second sequential signal form are chosen to be respectively, either two and three times, or three and four times, the highest-permissible data transition rates of the separately-generated binary information signals.

12. A signal transformation means as described in claim 11, wherein a common synchronous logic time-base is chosen to have a frequency equal to the highest-permissible data transition rates of the separately-generated binary information signals, multiplied by an integer value of 192, 96, 48, 24, 12, each of these integers being a common multiple of ratios of pulse frequencies of the second sequential signal form to the highest permissible data transition rates of the separately-generated binary information signals.

13. A signal transformation means as described in claim 1, in which common circuits are combined such as to transform separately-generated serial binary information signals to the second sequential signal form at one time, and from the second sequential signal form to the final sequential binary signal at another time, as determined by states of a separately-controlled input signal.

14. A signal transformation means as described in claim 1, in which a first said signal transformation means transforms separately-generated serial binary information signals to the second sequential signal form and a second said signal transformation means transforms signals of the second sequential signal form, received from a separate first said signal transformation means by separated light or other suitable paths, to a final sequential binary signal, at concurrent times.

15. A data, control or sensing network, comprised of a plurality of signal transformation means as described in claim 1, and employing light or other suitable transmission means to pass data or control signals among separate devices or equipments.

16. A signal transformation means as described in claim 1, including a decoding means and an encoding means to enable certain non-return-to-zero serial data formats, as required by separate devices or equipments, to be transmitted and received via the signal transformation means of claim 1 at maximum data rates which are equal to data rates of other non-return-to-zero serial data formats.

17. A signal transformation means as described in claim 16, wherein the decoding means and the encoding means that enable transmission of certain non-return-to-zero serial formats at maximum data rates equal to data rates of other non-return-to-zero formats are specifically compatible with Manchester-encoded separately-generated binary information signals.

18. A signal transformation means as described in claim 17 wherein said decoding means includes synchronization means to require continuous transitions to occur in the separately-generated binary information signals, in order to begin or to continuously produce a sequence of pulses comprising the second sequential signal transmitted.

19. A signal transformation means as described in claim 17, wherein the encoding means includes synchronization means to require a continuous sequence of pulses comprising the second sequential signal received, in order to begin, or to continuously produce, transitions in the final sequential binary signal.

20. A signal transformation means as described in claim 17, wherein either an encoding means or a decoding means to enable Manchester-encoded data formats to be transmitted and received at data rates which are equal to data rates of other non-return-to-zero serial data formats, can be disabled to provide for conversion of serial data formats.

21. A signal transformation means as described in claim 5, including signal-detection means, further comprising a signal-error detection means, to provide separate indication of presence, absence, out-of range intervals or disruption of

the second sequential signal form received.

22. A signal transformation means as described in claim 21, wherein the signal-detection means provides for certain non-recurring, normal and expected, disruptions in the sequence of pulses comprising the second sequential signal received, without producing corresponding disruptions in the final sequential binary signal.

23. A signal transformation means as described in claim 22, wherein non-recurring, normal and expected disruptions in the sequence of pulses comprising the second sequential signal received result from synchronization of the second sequential signals to state-transitions of the separately-generated serial binary signals, prior to transmission.

24. A signal transformation means as described in claim 1, in which a summation of times required for transformation of separately-generated serial binary signals to the final sequential binary signal is less than an interval equal to a reciprocal of the highest-permissible data transition rate of the separately-generated binary information signals.

25. A signal transformation means as described in claim 1, in which the separately-generated serial binary information signals, generated at commonly used data-communication (baud) rates, can be passed at, or at a number of integer sub-multiples of, a maximum data transition rate for which circuit elements of the signal transformation means are designed, without requiring changes in operation, timing or characterization of any of said circuit elements.

26. A signal transformation means as described in claim 25, in which maximum data rates, for which circuit elements of the signal transformation means are readily designed, using presently available circuit components and techniques, are at least 38,400 bits per second.

27. A signal transformation means as described in claim 11, wherein separately generated serial binary signals to be transmitted may be obtained from TXD signal pins, and the final sequential binary signals received may compatibly be connected to RXD signal pins, as provided on any of several types of commonly used and available universal asynchronous receiver-transmitters or like signaling devices.

28. A data, control or sensing system or network or a part thereof, comprised of a plurality of signal transformation means as described in claim 26, wherein the separately generated serial binary information signals to be transmitted and the final sequential binary signals received are passed as the second sequential signal form via light path or other suitable medium, between or among computing devices and/or compatible devices and equipments.

29. A signal transformation means as described in claim 11, in which separately-generated serial binary signals, generated at commonly used data rates in networks for sensing, communicating and controlling purposes, can be passed at, or at a number of integer sub-multiples of, a maximum data transition rate for which circuit elements of the signal transformation means are designed, without requiring changes in operation, timing or characterization of any of said circuit elements.

30. A signal transformation means as described in claim 29, in which maximum data rates for which circuit elements of the signal transformation means are readily designed using presently available circuit components and techniques, are at least 39,063 bits per second.

31. A signal transformation means as described in claim 11, wherein the separately-generated serial binary signals to be transmitted may be obtained from output signal pins, and the final sequential binary signals received may compatibly be connected to input signal pins, and additional transmit/receive control signals are also compatibly connected to other pins, provided by a cell or other device used in a network for sensing, communicating and controlling.

32. A data, control or sensing system or network or a part thereof, comprised of a plurality of signal transformation means as described in claim 31, wherein separately generated serial binary information signals to be transmitted and the final sequential binary signals received are passed as the second sequential signal form via light path or other suitable medium, between or among computing devices and/or compatible devices and equipments.

33. A light-signal repeater, comprised of a pair of signal transformation means as described in claim 11, each including signal-detection means to provide a separate carrier-present output signal when the second sequential signal form is received, compatibly interconnected such that each, normally set to receive the second sequential signal form, will, upon detection of the second sequential signal form, set a second signal transformation means into a condition required for it to transform and re-transmit signals from the final sequential binary signal of a receiving signal transformation means, thereby repeating and amplifying light-transmitted signals around, through or past an optical barrier, in either signaling direction.

34. A plurality of light-signal repeaters as described in claim 33, each repeating and amplifying light-transmitted signals around, through or past optical barriers, in both signaling directions, thereby passing serial binary information signals between or among devices and equipments separated by more than one optical barrier.

35. In a signal transformation means as described in claim 1, an improvement comprising a logic clock-frequency prescaling means, included to produce a synchronous logic time-base, suitable for synchronizing and timing all logic operations of the signal-transformation means, from external clock signals of certain different, commonly-used frequencies, that are usually chosen to suit requirements of connected devices or equipments.

36. The improvement defined in claim 35, in which said logic clock-frequency prescaling means, when enabled, performs a non-integer division of an external clock signal on a transition-by-transition basis, rather than on a cycle-by-cycle basis, to produce a synchronous logic time-base which is more regular than other conventional means, thus producing minimal degradation of accuracy of signal-timing functions of the signal transformation means.

37. A light-path transceiver, comprising the signal transformation means according to claim 1, a light transmission means, suitable to transmit said second sequential signal form derived from states and state-transitions of the separately-generated serial binary information signals, and a light-sensing means to convert received light to electrical analog signals for amplification and signal level sensing to produce a binary signal whose transition intervals are timed, classified and are used to produce a final sequential binary signal essentially duplicating binary states and transition-timing characteristics of said separately-generated serial binary information signals.

38. The light-path transceiver of claim 37, used to transmit and receive light signals over a distance, through a light-permeable medium such as space, water or air.

39. The light-path transceiver of claim 37, used to transmit and receive infrared light signals over a distance.

40. The light-path transceiver of claim 37, wherein spectral output characteristics of said light transmission means closely match spectral response characteristics of said light-sensing means.

41. In a light-path transceiver according to claim 37, an improvement wherein one or more light-spectrum filtering means are used within a light path to minimize disturbances in electrical signals derived from the second sequential signal received, which disturbances may cause errors in response of the light-path transceiver when the light-path transceiver is operated as a light-signal receiver.

42. A signal transformation means as described in claim 5, wherein a lesser of two pulse rates chosen to comprise the second sequential signal form transmitted represents a logic zero state and a greater of two pulse rates chosen to comprise the second sequential signal form transmitted represents a logic one state.

43. A signal transformation means as described in claim 5, wherein a range encompassing a lesser of two pulse rates chosen to comprise the second sequential signal form, as received, represents a logic zero state, and a range encompassing a greater of two pulse rates chosen to comprise the second sequential signal form, as received, represents a logic one state.

44. A signal transformation means as described in claim 43, wherein received signals having no detectable transitions, or transitions which represent pulse rates outside either range described in claim 43, will operate to place the final sequential binary signal to an inactive, non-interfering state.

45. A signal transformation means as described in claim 43, wherein a signal-detection means is included, further comprising a signal-error detection means that provides a separate indication of signal presence, when received signals having no detectable transitions or transitions that represent pulse rates outside either range described in claim 43 are present, will operate to place said separate indication of signal presence in its false state.

46. A signal transformation means as described in claim 5, wherein reception of binary signal transitions within a range encompassing pulse rates chosen to comprise the second sequential signal form, as received, representing a logic one state, must be detected before reception of binary signal transitions within a range encompassing pulse rates chosen to comprise the second sequential signal form, as received, representing a logic zero state.