Patent ID: 8019240

Claim:
A developing apparatus used in an electrophotographic image forming apparatus, the developing apparatus comprising: a developer carrying member for developing an electrostatic latent image formed on an electrophotographic photosensitive member; a developing container for containing a developer to be supplied to the developer carrying member; a developer conveying member provided in the developing container, for supplying the developer within the developing container to the developer carrying member; a light transmissive member which has a light emitting guide portion and a light receiving guide portion, wherein the light emitting guide portion is adapted to guide, into the developing container, a detecting light which is emitted from a light emitting element provided in an apparatus main body of the electrophotographic image forming apparatus and which is used for detecting a developer remaining amount in the developing container, and wherein the light receiving guide portion is adapted to guide the detecting light that has passed through the developing container to a light receiving element provided in the apparatus main body; and a covering member for covering an area between the light emitting guide portion and the light receiving guide portion in the light transmissive member, wherein the covering member reduces the detecting light which travels toward the light receiving elemnt, and wherein the covering member an the light transmissive member are formed integrally with each other by coinjection molding.