Abstract: There is provided a kit having integrally a supply toner storage section for supplying a developer to a developing unit, and a waste toner storing section for storing the developer removed from a photosensitive body by a non-transferred toner removing means. The kit is detachable from the developing unit and the non-transferred toner removing means. The condition of (B)>(C)>(B).times.(A) is satisfied, where (A)=the non-transfer rate by a transfer charger, (B)=the developer storage amount of the supply toner storage section, and (C)=the developer storage amount of the waste toner storage section.

Abstract: There is provided a kit comprising integrally a supply toner storage section for supplying a developer to a developing unit, and a waste toner storing section for storing the developer removed from a photosensitive body by non-transferred toner removing means. The kit is detachable from the developing unit and the non-transferred toner removing means.

Abstract: The improved image building apparatus is constructed such that recording medium, that is, recording paper, is normally introduced into the image building section with a thermal head or the like component incorporated therein while it is stretched under the effect of a certain intensity of braking force which is exerted on the recording paper from the rear side as seen in the direction of transportation thereof. This causes an occurrence of such a malfunction as skewing, loosening or the like of the recording paper to be inhibited at least in the image building section. Thus, image building can be achieved without incorrect registering, deformation or the like recognized with the printing paper on which image transference has been carried out.