Patent ID: 7525893

Claim:
An electron beam recorder comprising: an electron optical system for irradiating an electron beam on a master of an information recording medium; and an electron beam irradiation position detecting unit for detecting an irradiation position of the electron beam in the electron optical system while the electron beam is being irradiated on the master by the electron optical system, the electron beam irradiation position detecting unit including: a shielding plate for shielding the electron beam, which has a hole for shaping the electron beam to a desired beam diameter and is divided, at the hole, into first and second regions in a direction substantially perpendicular to a horizontal feed direction of the master; and first and second electron beam detectors for detecting, as first and second detection signals, quantities of the electron beam shielded by the first and second regions of the shielding plate, respectively such that a difference signal of the first and second detection signals is obtained.