Developer seal

In an electro-photographic image developing system including a photo conductive member having an image carrying surface, housing means forming a reservoir chamber containing toner material and carrier particles and having a communicating opening facing said surface, and means for carrying a layer of said carrier particles and triboelectrically attached toner material from said chamber to a position within said opening and proximate said image carrying surface and then back into said reservoir through a return passageway formed between one side of said opening and the particle carrying surface of said carrying means, the improvement comprising:

• an elongated flexible and resilient strip means for closing said return passageway and having one elongated side affixed to said housing means at said one side of said opening and the other elongated side of said strip means resiliently extending into engagement with the particle carrying surface of said carrying means such that carrier particles transported thereby into said opening past the surface of said photo conductive surface and then to said return passageway cause said resilient strip means to be temporarily deformed away from said particle carrying surface thereby opening said passageway to admit said carrier particles, whereby toner dust created within said chamber is contained therewithin.