Transmitter for tire condition monitoring apparatus

• US 20050078002A1
• Filed: 03/17/2004
• Published: 04/14/2005
• Est. Priority Date: 10/14/2003
• Status: Active Grant

• Current Assignee: Pacific Industrial Company Limited
• Original Assignee: Pacific Industrial Company Limited
• Inventors: Okubo, Youichi
• Granted Patent: US 7,212,105 B2
• Time in Patent Office: Days
• US Class Current: 340/445
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A transmitter of a tire condition monitoring apparatus has an acceleration sensor, a transmission circuit, an antenna and a transmission controller. The transmitter is provided in a tire of a vehicle. The acceleration sensor detects a running state of the vehicle. The transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal. The antenna wirelessly transmits the transmission signal. The transmission controller changes a transmission power of the transmission circuit according to a detection result of the running state detection device. This is capable of transmitting signals with an appropriate transmission power.

Claims

1. A transmitter of a tire condition monitoring apparatus, wherein the transmitter is provided in a tire of a vehicle, the transmitter comprising:

a running state detection device for detecting a running state of the vehicle;

a transmission circuit, wherein the transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal;

an antenna for wirelessly transmitting the transmission signal; and

a controller that changes a transmission power of the transmission circuit according to a detection result of the running state detection device.

2. The transmitter according to claim 1, wherein the running state detection device includes an acceleration sensor.

3. The transmitter according to claim 1, wherein the controller determines whether the vehicle is moving based on a detection result of the running state detection device, and wherein, when the vehicle is determined to be moving, the controller makes the transmission power of the transmission circuit greater than the transmission power when the vehicle is determined not to be moving.

4. The transmitter according to claim 1, wherein the running state detection device detects a parameter that correlates with a speed of the vehicle, and wherein the controller changes the transmission power of the transmission circuit according to the speed pf the vehicle.

5. The transmitter according to claim 4, wherein the controller increases the transmission power of the transmission circuit for a greater value of the speed of the vehicle.

6. The transmission according to claim 4, wherein, when the speed of the vehicle is greater than or equal to a reference value, the controller makes the transmission power of the transmission circuit greater than the transmission power when the speed of the vehicle is less than the reference value.

7. A transmitter of a tire condition monitoring apparatus, wherein the transmitter is attached to a vehicle wheel to be located inside a tire, the transmitter comprising:

a detection device for detecting that the transmitter is attached to the wheel;

a transmission circuit, wherein the transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal;

an antenna for wirelessly transmitting the transmission signal; and

a controller that changes a transmission power of the transmission circuit according to a detection result of the detection device.

8. The transmitter according to claim 7, wherein the detection device is a switch that is switched to different states when the transmitter is attached to the wheel and when the transmitter is detached from the wheel.

9. The transmitter according to claim 7, wherein, when the transmitter is attached to the wheel, the controller makes the transmission power of the transmission circuit greater than the transmission power when the transmitter is detached from the wheel.

10. A transmitter of a tire condition monitoring apparatus, wherein the transmitter is provided in a tire of a vehicle and wirelessly transmits data representing a condition of the tire, the transmitter comprising:

a transmission circuit, wherein the transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal;

an antenna for wirelessly transmitting the transmission signal; and

a controller for detecting whether the antenna is detuned, wherein the controller changes a transmission power of the transmission circuit according to a detection result.

11. The transmitter according to claim 10, wherein, when the transmission antenna is determined to be detuned, the controller makes the transmission power of the transmission circuit greater than the transmission power when the transmission antenna is determined not to be detuned.

12. A method for controlling a transmission power, the method being applied to a transmitter of a tire condition monitoring apparatus, wherein the transmitter is provided in a tire of a vehicle and includes a transmission circuit and an antenna, wherein the transmission circuit generates a transmission signal containing data representing a condition of the tire and outputs the transmission signal, and wherein the antenna wirelessly transmits the transmission signal, the method comprising:

detecting a running state of the vehicle with a running state detection device; and

changing a transmission power of the transmission circuit according to a detection result of the running state detection device.