Detecting method for color shade or the like

Abstract

Abstract PURPOSE:To eliminate the influence of the upward/downward movement of a body to be measured by comparing the quantities of reflected light or transmitted light measured by plural photodetectors arranged in the conveyance direction of the body to be measured with each other at the same time. CONSTITUTION:Photodetection parts 7a and 8a at one-terminal sides of optical fibers 7 and 8 are arranged above a product 6 at a proper interval in the conveyance direction. The light receiving parts 7a and 8a receive light which is emitted by a white light source and reflected by the product 6, and light beams emitted by three branch bundles 7b-8d are diffracted spectrally by spectral filters 9a-10c, received by optoelectric converters 11a-12c, and converted into voltages through current-voltage converters 13a-14c. Photoelectric signals are inputted to comparators 15a-15c and compared with photoelectric signals passed through the spectral filters 9a-10c, which output operating signals when their differences exceed a constant voltage difference. Those signals are passed through power amplifier circuits 16a-16c to operate relays 17a-17c and inputted to a pulse counter 18, so that they are counted as a value proportional to color shade 16, etc.

Inventors

• 👤 Yukio Murata
• 👤 村田　幸男

Bibliographic Details