| 主权项 |
1. A developer accommodating unit, usable with an electrophotographic image forming apparatus, for accommodating developer for an electrophotographic image forming process, said developer accommodating unit comprising:
a developer accommodating chamber, formed by a developer accommodating frame, for accommodating the developer; and a light guide member, provided through said developer accommodating frame, for detecting a remaining toner amount, wherein said light guide member includes (i) a light-incident-side light guide portion for guiding detection light coming from a light emitting element provided outside of said developer accommodating chamber to an inside of said developer accommodating chamber and (ii) a light-emergent-side light guide portion for guiding the detection light passed through the inside of said developer accommodating chamber to a light receiving element provided outside of said developer accommodating chamber, said light-incident-side light guide portion and said light-emergent-side light guide portion being integrally formed, wherein said light-incident-side light guide portion includes an incident portion on which the detection light is incident, and includes a light-emergent-side window through which the detection light emerges into said developer accommodating chamber, wherein said light-emergent-side light guide portion includes a light-incident-side window on which the detection light passed through the inside of said developer accommodating chamber is incident, and includes an emergent portion from which the detection light emerges toward the light receiving element, wherein said developer accommodating frame includes a light guide member mounting portion for mounting said light guide member, said light guide member mounting portion including an incident side opening and an emergent side opening for exposing said incident portion and said emergent portion, respectively, to the outside of said developer accommodating chamber, said light guide member mounting portion being provided on an inner side wall of said developer accommodating chamber, and wherein said light guide member (i) is mounted to said developer accommodating frame in a state in which said incident portion and said emergent portion are exposed through the incident side opening and the emergent side opening, respectively and (ii) is connected with said developer accommodating frame in a sealed state so that the outside and inside of said developer accommodating chamber are prevented from communicating with each other via the incident side opening and the emergent side opening. |
