Abstract: A deviation detecting system for detecting a relative positional deviation between first and second diffraction gratings, includes a light source, an illuminating device for projecting first and second light beams from the light source, having different directions of polarization, onto the first and second diffraction gratings along different directions, a first signal detecting device for detecting a first interference light signal from the first diffraction grating, being based on a combination of diffraction light of the first light beam and diffraction light of the second light beam, a second signal detecting device for detecting a second interference light signal from the second diffraction grating, being based on a combination of diffraction light of the first light beam and diffraction light of the second light, a first phase difference detecting device for detecting a phase difference between the first and second interference light signals and, a second phase difference detecting device for producing

Abstract: A magnetic toner is constituted by at least a binder resin and a magnetic iron oxide. The magnetic iron oxide is characterized by having an Fe(II) content of 18.5-24.1 wt. %, and shows a BET specific surface area of S (m.sup.2 /g) and an X-ray diffraction pattern giving a half-value width W (deg.) of a diffraction peak corresponding to 311 plane of the magnetic iron oxide in spinel structure, the values S and W satisfying: 4.5.times.10.sup.-3 S+0.130.ltoreq.W.ltoreq.4.5.times.10.sup.-3 S+0.160, and 4.5.ltoreq.S.ltoreq.11.0. Alternatively, the magnetic iron oxide is characterized by having a number-average particle size D satisfying a relationship with W of: -0.08D+0.180.ltoreq.W.ltoreq.-0.08D+0.212, and 0.10.ltoreq.D.ltoreq.0.45. The relationship between W and S or D indicates a good crystallinity of the magnetic iron oxide which provides the magnetic toner with a stable performance for a long period of time. The magnetic iron oxide can be obtained through a heating treatment at a temperature of 130.degree.

Abstract: A charging member for charging a body to be charged includes a blade member, a supporting member which supports the blade member, and an electrode layer which is provided on the blade member and is connected to the supporting member. The electrode layer is formed after connecting the blade member to the supporting member. A charging device uses the charging member. A process unit including the charging device is detachable relative to an image forming apparatus.

Abstract: An electrophotographic image forming member having on a substrate a photoconductive layer constructed by laminating a crystalline silicon layer and an amorphous silicon layer.