Object to be measured positioning method and concentration measurement for the object to be measured concentration measuring device

摘要

PROBLEM TO BE SOLVED: To accurately position an object to be measured in a density measuring position of a density measuring optical system.;SOLUTION: A color patch chart 202 is inserted while being transported at regular speed. By detecting a tip part of the patch chart 202 first, the chart 202 is fed at low speed. Pulse value of a pulse motor is reset by detecting a reference position indicator patch 216 at the side of the insertion tip. A reference position indicator patch 218 located at rear end side in a transport direction transported on the basis of the predetermined number of pulses (frame feed) is used for a frame feed control by the pulse control to recognize an error such as the slip of the transporting system. Length in the transport direction of the respective color patches of a color patch part 214 is not uniform and is intentionally and gradually made longer. This compensates the transport error caused by pulse transport control to some extent. The more the color patch advances to the rear end in the transport direction, the more the error accumulates, and the length of the color patch in the transport direction is changed accordingly.;COPYRIGHT: (C)2003,JPO