Ignition System

Abstract

An ignition system for a smoking machine is disclosed. The ignition system comprises an ignition head ( 12 ) for igniting one end of a smoking article which is held by a smoking machine, a sensor ( 18, 20 ) for detecting a distance between the end of the smoking article and the ignition head ( 12 ) in a direction parallel to the axis of the smoking article, and control means ( 21 ) for automatically adjusting ignition conditions in dependence on the detected distance. The sensor ( 18, 20 ) is arranged to detect the distance across a range of offset positions of the end of the smoking article in a plane perpendicular to the axis of the smoking article, which range is greater than the width of the end of the smoking article.

1 . An ignition system in a smoking machine, the ignition system comprising:
 an ignition head arranged to ignite one end of a smoking article which is held by a smoking machine;   a sensor which detects a distance between the end of the smoking article and the ignition head in a direction parallel to the axis of the smoking article;   a control unit which automatically adjusts ignition conditions in dependence on the detected distance; and   wherein the sensor is arranged to detect said distance across a range of offset positions of the end of the smoking article in a plane perpendicular to the axis of the smoking article, which range is greater than the width of the end of the smoking article.   
   
   
       2 . An ignition system according to  claim 1 , wherein the control unit is arranged to adjust the distance between the ignition head and the smoking article in dependence on the detected distance. 
   
   
       3 . An ignition system according to  claim 1 , wherein the control unit is arranged to adjust the operation of the ignition head in dependence on the detected distance. 
   
   
       4 . An ignition system according to  claim 1 , wherein the sensor comprises an emitter and a detector. 
   
   
       5 . An ignition system according to  claim 4  wherein the emitter is arranged to emit radiation which covers an area in a plane perpendicular to the axis of the smoking article which has dimensions greater than the depth of the radiation in a direction parallel to the axis of the smoking article. 
   
   
       6 . An ignition system according to  claim 1 , wherein the sensor comprises a plurality of emitters which are arranged to emit radiation in a plane perpendicular to the axis of the smoking article. 
   
   
       7 . An ignition system according to  claim 4 , wherein the emitter is arranged so as to emit a beam which is wider in the direction perpendicular to the axis of the smoking article than it is in the direction parallel to the axis of the smoking article. 
   
   
       8 . An ignition system according to  claim 4 , wherein the emitter is arranged to scan a beam in a plane perpendicular to the axis of the smoking article. 
   
   
       9 . An ignition system according to  claim 4 , further comprising a mechanism which moves the ignition system so as to move a beam from the emitter in a plane perpendicular to the axis of the smoking article. 
   
   
       10 . An ignition system according to  claim 4 , wherein the emitter is an emitter of electromagnetic radiation. 
   
   
       11 . An ignition system according to  claim 4 , wherein the sensor comprises a plurality of detectors. 
   
   
       12 . An ignition system according to  claim 1 , wherein the sensor comprises a plurality of emitters and a plurality of detectors, and each emitter is arranged to transmit a beam to a corresponding detector. 
   
   
       13 . An ignition system according to  claim 12  wherein all of the emitters are arranged to emit a beam at the same time. 
   
   
       14 . An ignition system according to  claim 12  wherein the emitters emit beams in a predetermined sequence. 
   
   
       15 . An ignition system according to  claim 12 , wherein each emitter is arranged to emit different type of radiation, and each detector is arranged to detect radiation from the corresponding emitter, but not from other emitters. 
   
   
       16 . An ignition system according to  claim 12 , wherein the emitters are spaced apart by no more than the width of a smoking article which it is desired to ignite. 
   
   
       17 . An ignition system according to  claim 4 , further comprising a lens which focuses radiation emitted from the emitter. 
   
   
       18 . An ignition system according to  claim 4 , further comprising a mask which masks radiation emitted from the emitter. 
   
   
       19 . An ignition system according to  claim 4 , wherein the ignition system is arranged to carry out a test procedure to determine the amount of radiation detected by the detector. 
   
   
       20 . An ignition system according to  claim 19 , wherein an amount of radiation emitted by the emitter is adjusted in dependence on the test procedure. 
   
   
       21 . An ignition system according to  claim 19  wherein the sensitivity of the detector is adjusted in dependence on the test procedure. 
   
   
       22 . An ignition system according to  claim 1  wherein the ignition head comprises a heat source. 
   
   
       23 . An ignition system according to  claim 1  wherein the ignition head is arranged such that it can ignite the smoking article across a range of offset positions of the end of the smoking article. 
   
   
       24 . An ignition system according to  claim 23  wherein the ignition head is of sufficient dimensions to ensure that the smoking article is lit even if the smoking article is offset from its anticipated position in a direction perpendicular to the axis of the smoking article by an amount greater than the width of the smoking article. 
   
   
       25 . An ignition system according to  claim 24 , further comprising a mechanism which adjusts the relative position of the ignition head and the smoking article in a direction perpendicular to the axis of the smoking article, in dependence on an output of the sensor. 
   
   
       26 . A smoking machine comprising an ignition system, the ignition system comprising:
 an ignition head arranged to ignite one end of a smoking article which is held by a smoking machine;   a sensor which detects a distance between the end of the smoking article and the ignition head in a direction parallel to the axis of the smoking article;   a control unit which automatically adjusts ignition conditions in dependence on the detected distance; and   wherein the sensor is arranged to detect said distance across a range of offset positions of the end of the smoking article in a plane perpendicular to the axis of the smoking article, which range is greater than the width of the end of the smoking article.   
   
   
       27 . A method of automatically igniting a smoking article held in a smoking machine using an ignition head, the method comprising:
 detecting a distance between the end of the smoking article and the ignition   head in a direction parallel to the axis of the smoking article;
 adjusting ignition conditions in dependence on the detected distance; 
 igniting one end of the smoking article; and 
 detecting said distance across a range of offset positions of the end of the smoking article in a plane perpendicular to the axis of the smoking article, which range is greater than the width of the end of the smoking article.