| 摘要 |
<p>PURPOSE:To remove the disturbance asynchronously when image of an object light source is picked up and its position is measured. CONSTITUTION:Light projecting operation is performed first to emit light on which is subjected to intensity modulation with a certain cyclic waveform from the light source. Then, an image picking-up process is performed, and an image sensor photodetects the projection light to pick up the image of the light source, and stores corresponding image data, for every pixel. Then, a read process is performed, the image sensor is accessed at least four times successively with cycles <=1/4 of the cyclic waveform, and the image data are read out, for every pixel, to generate time- series data S. Then, the product sum arithmetic of the time-series data S is performed by using a reference waveform I which is asynchronous with the cyclic waveform used for the intensity modulation and has a cycle R approximate to the cycle P of the cyclic waveform to find 1st product sum data after the disturbance is removed. At the same time, an orthogonal waveform Q which is 90 deg. out of phase with the reference waveform I is used to perform the product sum arithmetic of the time-series data S, and 2nd product sum data after disturbance removal are found as well. Lastly, the 1st and 2nd product sum data found, for every pixel, are used to perform image arithmetic, extracting the position of the light source.</p> |
