An organic light emitting display includes: scan lines for applying scan signals; control lines for applying control signals; and data lines for applying data signals. More specifically, this invention relates to the field of mass spectrometry, especially to the type of matrix-assisted laser desorptionionization, time-of-flight mass spectrometry used to analyze macromolecules, such as proteins or biomolecules. The electrical conducting member and electrical conducting layer function as a current return path. The guide assembly is interlocked with the base and is securable within the base opening such that the guide assembly has infinite adjustability within the base opening. A depth order may be restored based on a line tracing and an edge map generated from an input image, and a stereo image may be generated using depth information. The invention provides a black and white photothermographic material having high image quality and an excellent storability, and an image forming method.