A light-producing structure for a wheeled traveling case assembly includes a mini generator having a rotary shaft with a frictional wheel connected thereto to frictionally contact with an adjacent wheel of the assembly. 5 mm or less in an absolute value, and wherein the intermediate transfer belt is configured to receive, by transferring, a toner image formed by developing, with a toner, a latent image formed on an image bearing member. The pattern of fingered electrodes creates a longer and more complicated measurement signal shape which leads to a significant improvement of measurement sensitivity. The jet regulator provides an improved fractionating of the incoming individual jets. An RFID identifier is stored along with an indication of the time that the identifier was read.