APPARATUS FOR MEASURING CONCENTRATION OF DEVELOPER

摘要

PURPOSE: An apparatus for detecting a density of a developing solution is provided to detect a density of a developing solution by measuring transmissivity of the developing solution. CONSTITUTION: A base member(31) has a vessel(31a) for receiving a developing solution(36). A developing solution supply device(41,42) supplies a developing solution(36) to the vessel(31a). A bias member(35) is installed at the base member(31) to electrify a toner included in the developing solution(36). A conductive material is formed on a surface of a rotary roller(33). The developing solution(36) including the electrified toner particles forms a film of a predetermined thickness on the surface of the rotary roller(33). A light emitting device(37) and a light receiving device(39) measures a density of the developing solution(36) by irradiating the light to the film and receiving the light transmitting the film.