Position Sensor

Abstract

A hinge position sensor comprises first and second members connected together to provide a hinge, and an optical fibre or wave-guide connected between the first and second members to provide a communication link between the first and second members. A laser or LED is coupled to the optical fibre or wave-guide to transmit optical signals between the first and second members and the optical signal is received by a photo-detector. The optical fibre or wave-guide is physically distorted by actuation of the hinge such that light escapes from the optical fibre or wave-guide. The optical power level received by the photo-detector is used to determine the position of the hinge.

1 . An apparatus comprising:
 a first member and a second member connected together to provide a pivoting joint;   an optical wave-guide;   a processor;   a light emitter to transmit an optical signal through the optical wave-guide; and   a light detector to detect the optical signal from the optical wave-guide;   wherein the processor is configured to process the detected signal to determine the signal-loss through the optical wave-guide and to use the determined signal-loss to determine the position of the joint.   
   
   
       2 . An apparatus according to  claim 1 , wherein the processor is configured to use the determined position of the joint to control the implementation of a power saving mode in the apparatus. 
   
   
       3 . An apparatus according to  claim 2 , wherein if the determined signal-loss increases above a predetermined threshold, the joint is determined to be closed. 
   
   
       4 . An apparatus according to  claim 2 , wherein if the determined signal-loss falls below a predetermined threshold, the joint is determined to be open. 
   
   
       5 . An apparatus according to  claim 1 , wherein the optical wave-guide comprises an optical fiber. 
   
   
       6 . An apparatus according to  claim 1  comprising a mobile telephone. 
   
   
       7 . An apparatus comprising:
 a lid and a base;   a light emitter to transmit optical signals;   a light detector for detecting the power level of optical signals; and   an optical wave-guide;   wherein the optical wave-guide is coupled to the light emitter and is connected between the lid and the base to provide a transmission medium for the optical signals, wherein the apparatus is configured to use the optical power level detected by the light detector to determine the position of the lid relative to the base, and wherein the apparatus is configured to use the position of the lid to employ a power-saving mode in the apparatus.   
   
   
       8 . The apparatus according to  claim 7 , wherein the optical wave-guide comprises an optical fiber. 
   
   
       9 . The apparatus according to  claim 7 , wherein if a determined signal-loss detected by the light detector increases above a predetermined threshold, the lid is determined to be closed. 
   
   
       10 . The apparatus according to  claim 7 , wherein if a determined signal-loss detected by the light detector falls below a predetermined threshold, the lid is determined to be open. 
   
   
       11 . A method comprising:
 transmitting an optical signal through an optical wave-guide;   detecting an optical power level of an optical signal from the optical wave guide;   determining the position of a lid of an apparatus relative to a base of the apparatus using the detected optical power level;   employing a power saving mode in the apparatus based on the determined position of the lid of the apparatus.   
   
   
       12 . The method of  claim 11 , wherein transmitting comprises transmitting the optical signal through an optical fiber. 
   
   
       13 . An apparatus comprising:
 means for transmitting an optical signal through an optical wave-guide;   means for detecting an optical power level of an optical signal from the optical wave-guide;   means for determining the position of a lid of an apparatus relative to a base of the apparatus using the detected optical power level;   means for employing a power saving mode in the apparatus based on the determined position of the lid of the apparatus.   
   
   
       14 . The apparatus of  claim 13 , wherein the optical wave-guide comprises an optical fiber. 
   
   
       15 . One or more computer readable media storing machine-readable instructions which, when executed by a computer apparatus, control the computer apparatus to perform a method comprising:
 determining the position of a lid of an apparatus relative to a base of the apparatus using a detected optical power level of an optical signal from an optical wave-guide;   employing a power saving mode in the apparatus based on the determined position of the lid of the apparatus.   
   
   
       16 . The computer readable media of  claim 15 , wherein the optical wave guide comprises an optical fiber. 
   
   
       17 . The computer readable media of  claim 15 , wherein the detected optical power level comprises a signal loss detected by a light detector that detects the optical signal from the optical wave-guide. 
   
   
       18 . The computer readable media of  claim 17 , wherein if the detected signal loss increases above a predetermined threshold, the lid is determined to be closed. 
   
   
       19 . The computer readable media of  claim 17 , wherein if the detected signal loss decreased below a predetermined threshold, the lid is determined to be closed.