To make development efficient and to reduce the cost of a mold on the occasion of developing several kinds of image plane sizes, in regard to an electronic white board used for a conference room and the like.

A reading part 1 and an output part 2 are integrated in a unit. The unit can recognize image planes 3 of several kinds of sizes (standard size, wide size, narrow size, etc.), and a speed reduction mechanism is provided so that a feeding speed of an image plane film 14 conformed to the image plane sizes be obtained, for image plane parts of several kinds of sizes which can be fitted to the unit. Thereby the image planes of the several kinds of sizes can be controlled by the same control device.