Data communication system

Abstract

A data communication system installed in an electric machine includes a transmission terminal and a reception terminal both mounted on the electric machine, a transmission-side opposed conductive member disposed on the transmission terminal, a transmission circuit for applying voltage between the transmission-side conductive member and the conductive body, thereby changing electric field generated on the entire surface of the conductive body, the voltage being changed according to information to be transmitted, a reception-side opposed conductive member provided on the reception terminal, thereby being capable of generating potential difference according to the electric field between the conductive body and the reception-side opposed conductive member, and a reception circuit for receiving the information based on a change in the potential difference between the conductive body and the reception-side opposed conductive member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become clear upon reviewing the following description of the embodiment, with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of a data communication system in accordance with a first embodiment of the present invention;

FIG. 2 is a conceptual illustration of a vehicle provided with the data communication system;

FIG. 3 is a sectional view of a tire and a tire pressure detector;

FIG. 4 is an electrical circuit diagram of the tire pressure detector;

FIG. 5 is an electrical circuit diagram of a tire monitor device;

FIG. 6 is another electrical circuit diagram of the tire monitor device;

FIG. 7 is an electrical circuit diagram of the data communication system;

FIG. 8 is a conceptual illustration of the data communication system;

FIG. 9 is an electrical circuit diagram of the data communication system in accordance with a second embodiment of the invention; and

FIG. 10 is a waveform chart of a digital signal the reception terminal transmits based on reception data.

Claims

1. A data communication system installed in an electric machine including an electrically conductive body insulated from the ground and having a surface, the system transmitting and receiving information between two different locations in the electric machine, the system comprising: a transmission terminal and a reception terminal both mounted on the electric machine;a transmission-side opposed conductive member provided on the transmission terminal so as to be opposed to the conductive body;a transmission circuit provided on the transmission terminal for applying voltage between the transmission-side opposed conductive member and the conductive body, thereby changing electric field generated on the entire surface of the conductive body, said voltage being changed according to information to be transmitted;a reception-side opposed conductive member provided on the reception terminal so as to be opposed to the conductive body, thereby being capable of generating potential difference according to the electric field between the conductive body and the reception-side opposed conductive member; anda reception circuit provided on the reception terminal for receiving the information based on a change in the potential difference between the conductive body and the reception-side opposed conductive member.

2. The system according to claim 1, wherein a plurality of transmission/reception terminals are provided each for serving both as the transmission terminal and as the reception terminal.

3. The system according to claim 1, wherein the transmission circuit processes the information as a digital signal and switches voltage between a high level and a low level according to a binary voltage of the digital signal, said voltage being applied between the transmission-side opposed conductive member and the conductive body, and the reception circuit receives as the digital signal a change in potential difference between the conductive body and the reception-side opposed conductive member.

4. The system according to claim 1, further comprising a modulation circuit provided on the transmission circuit for modulating a carrier wave according to the information, thereby applying amplitude voltage of the carrier wave between the transmission-side opposed conductive member and the conductive body, and a demodulation circuit provided on the reception circuit for obtaining as a carrier wave a change in potential difference between the conductive body and the reception-side opposed conductive member and demodulating the carrier wave, thereby obtaining information.

5. The system according to claim 1, further comprising a voltage follower circuit provided on the reception circuit so as to be input the potential difference between the conductive body and the reception-side opposed conductive member into.

6. The system according to claim 3, further comprising a voltage follower circuit provided on the reception circuit so as to be input the potential difference between the conductive body and the reception-side opposed conductive member into.

7. The system according to claim 4, further comprising a voltage follower circuit provided on the reception circuit so as to be input the potential difference between the conductive body and the reception-side opposed conductive member into.

8. The system according to claim 1, wherein the transmission circuit applies voltage to the transmission-side opposed conductive member with the conductive body serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

9. The system according to claim 3, wherein the transmission circuit applies voltage to the transmission-side opposed conductive member with the conductive body serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

10. The system according to claim 4, wherein the transmission circuit applies voltage to the transmission-side opposed conductive member with the conductive body serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

11. The system according to claim 5, wherein the transmission circuit applies voltage to the transmission-side opposed conductive member with the conductive body serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

12. The system according to claim 1, wherein the transmission circuit applies voltage to the conductive body with the transmission-side opposed conductive member serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

13. The system according to claim 3, wherein the transmission circuit applies voltage to the conductive body with the transmission-side opposed conductive member serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

14. The system according to claim 4, wherein the transmission circuit applies voltage to the conductive body with the transmission-side opposed conductive member serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

15. The system according to claim 5, wherein the transmission circuit applies voltage to the conductive body with the transmission-side opposed conductive member serving as an electrical ground to generate an electric field between the transmission-side opposed conductive member and the conductive body.

16. The system according to claim 1, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the conductive body serving as an electrical ground.

17. The system according to claim 3, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the conductive body serving as an electrical ground.

18. The system according to claim 4, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the conductive body serving as an electrical ground.

19. The system according to claim 5, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the conductive body serving as an electrical ground.

20. The system according to claim 8, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the conductive body serving as an electrical ground.

21. The system according to claim 1, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the reception-side opposed conductive member serving as an electrical ground.

22. The system according to claim 3, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the reception-side opposed conductive member serving as an electrical ground.

23. The system according to claim 4, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the reception-side opposed conductive member serving as an electrical ground.

24. The system according to claim 5, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the reception-side opposed conductive member serving as an electrical ground.

25. The system according to claim 8, wherein the reception circuit picks up an electric field between the reception-side opposed conductive member and the conductive body with the reception-side opposed conductive member serving as an electrical ground.

26. The system according to claim 1, wherein each of the transmission- and reception-side opposed conductive members comprises a flat-plate antenna, linear antenna, spiral antenna, stepped antenna or pattern antenna.

27. The system according to claim 1, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

28. The system according to claim 2, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

29. The system according to claim 3, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

30. The system according to claim 4, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

31. The system according to claim 5, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

32. The system according to claim 8, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

33. The system according to claim 12, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

34. The system according to claim 16, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

35. The system according to claim 21, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

36. The system according to claim 26, wherein the electric machine is a vehicle and the conductive body is a vehicle-constituting conductor including a chassis, main body, axle shafts and tire wheels and insulated from the ground by tires.

37. The system according to claim 27, wherein the transmission terminal is a tire pressure detector which is mounted on the tire wheel for detecting an internal pressure of the tire, thereby transmitting a result of detection, the transmission-side opposed conductive member is mounted on the transmission terminal so as to be opposed to the tire wheel, the reception terminal is a tire monitor device mounted on the main body for receiving a result of detection of tire internal pressure, and the reception-side opposed conductive member is provided on the reception terminal so as to be opposed to the main body.

38. The system according to claim 29, wherein the transmission terminal is a tire pressure detector which is mounted on the tire wheel for detecting an internal pressure of the tire, thereby transmitting a result of detection, the transmission-side opposed conductive member is mounted on the transmission terminal so as to be opposed to the tire wheel, the reception terminal is a tire monitor device mounted on the main body for receiving a result of detection of tire internal pressure, and the reception-side opposed conductive member is provided on the reception terminal so as to be opposed to the main body.

39. The system according to claim 30, wherein the transmission terminal is a tire pressure detector which is mounted on the tire wheel for detecting an internal pressure of the tire, thereby transmitting a result of detection, the transmission-side opposed conductive member is mounted on the transmission terminal so as to be opposed to the tire wheel, the reception terminal is a tire monitor device mounted on the main body for receiving a result of detection of tire internal pressure, and the reception-side opposed conductive member is provided on the reception terminal so as to be opposed to the main body.

40. The system according to claim 31, wherein the transmission terminal is a tire pressure detector which is mounted on the tire wheel for detecting an internal pressure of the tire, thereby transmitting a result of detection, the transmission-side opposed conductive member is mounted on the transmission terminal so as to be opposed to the tire wheel, the reception terminal is a tire monitor device mounted on the main body for receiving a result of detection of tire internal pressure, and the reception-side opposed conductive member is provided on the reception terminal so as to be opposed to the main body.

41. The system according to claim 32, wherein the transmission terminal is a tire pressure detector which is mounted on the tire wheel for detecting an internal pressure of the tire, thereby transmitting a result of detection, the transmission-side opposed conductive member is mounted on the transmission terminal so as to be opposed to the tire wheel, the reception terminal is a tire monitor device mounted on the main body for receiving a result of detection of tire internal pressure, and the reception-side opposed conductive member is provided on the reception terminal so as to be opposed to the main body.

42. A data communication method in which a transmission terminal and a reception terminal are provided at two different locations on an electric machine including an electrically conductive body insulated from the ground and having a surface, the method comprising transmitting information by generating an electric field covering the entire surface of the conductive body by the transmission terminal so that electric-field energy is concentrated near the surface of the conductive body and changing the electric field, and picking up the electric field by the reception terminal, receiving the information.