The upper tray held finely sifted wood ash, tamped flat and smooth, over which the wooden grid template was placed. A furrow was cut into the ash in the shape of the grid lines and then filled with powdered incense which burned at a uniform rate. Once the incense was placed into the continuous track, the grid was removed and the incense ignited. The latticework cover was then put in place to prevent a breeze from accelerating the rate of combustion of the burning incense. The incense would burn continuously for hours as the lighted edge made its way around the grid design.

Continual offerings of incense using a jokoban were often found in Japanese Buddhist temples during religious rites. Because long periods of time could be measured by the amount of incense burned, this type of Japanese incense clock was also used in community life as well as in the temples. Examples of old kobandokei show burn scars, overall evidence of handling and the presence of ash or powdered incense. Relatively few examples of antique incense clocks have survived. This is a rare item for Buddhist temples or serious Buddhist practitioners.