| 摘要 |
PURPOSE:To always keep constant resolution and to accomplish high speed decision by performing normalization for the change of the illuminance of a light source like analog. CONSTITUTION:The respective components of the output of resolved wavelength on a monitor side which is directly taken out from a light source 1 and the output of resolved wavelength on an object side taken out owing to the reflection, etc., on an object 9 are guided to logarithmic amplifiers LA1-LA6 and logarithmically converted to be outputted. The corresponding outputs of the components of resolved wavelength are respectively supplied to differential amplifiers DA1-DA3 so as to obtain the difference of logarithmic function. Since the difference is nothing but the logarithm of the ratio of the components of resolved wavelength, the normalization for the change of the illuminance of the light source can be performed. The normalization of the measured value for the change of the illuminance of the light source is all performed by an analog circuit, so that a deciding speed can be made remarkably high. The obtained value is logarithmically compressed, whereas the lowering of resolution can be prevented even if the illuminance of the light source decreases or the reflectance or the transmittivity of the object is low. |
