Abstract: An insert nut includes a cylindrical portion into which a bolt is removably insertable. An inner periphery of the cylindrical portion includes a first region, a second region and a third region which are provided in the order named from an upstream side to a downstream side with respect to an insertion direction of the bolt at an inner periphery thereof. The first region and the third region include a female screw portion threadably engageable with the bolt. The second region has a minimum inner diameter larger than D1+2×h1×0.3, where D1 is an inner diameter of the female screw portion in the first region at a screw thread position and h1 is a height of a screw thread of the female screw portion in the first region.

Abstract: An insert nut includes a cylindrical portion into which a bolt is removably insertable. An inner periphery of the cylindrical portion includes a first region, a second region and a third region which are provided in the order named from an upstream side to a downstream side with respect to an insertion direction of the bolt at an inner periphery thereof. The first region and the third region include a female screw portion threadably engageable with the bolt. The second region has a minimum inner diameter larger than D1+2×h1×0.3, where D1 is an inner diameter of the female screw portion in the first region at a screw thread position and h1 is a height of a screw thread of the female screw portion in the first region.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes a rotatable photosensitive drum; a charging roller for contacting and electrically charging the drum; a spacer for supporting a rotation shaft of the charging roller to space the drum from the charging roller; and an urging member for contacting the spacer to urge the charging roller toward the drum; wherein the spacer is movable between a first position for spacing the charging roller from the drum and a second position for contacting the charging roller to the drum, and an urging force of the urging member applied to the spacer is smaller when the spacer is in the second position than when the spacer is in the first position.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes a rotatable photosensitive drum; a charging roller for contacting and electrically charging the drum; a spacer for supporting a rotation shaft of the charging roller to space the drum from the charging roller; and an urging member for contacting the spacer to urge the charging roller toward the drum; wherein the spacer is movable between a first position for spacing the charging roller from the drum and a second position for contacting the charging roller to the drum, and an urging force of the urging member applied to the spacer is smaller when the spacer is in the second position than when the spacer is in the first position.

Abstract: An image pickup apparatus has an adjusting mechanism for zoom lens unit so that the apparatus is made compactly. The zoom lens unit is constituted by a first group having a negative refracting power, a second group having a positive refracting power, a stop, a third group having a positive refracting power and a fourth group having a negative refracting power which are sequentially arranged from the object side to be substantially symmetrical about the stop. An image forming magnification is changed by moving whole system and moving the second and third groups on an optical axis thereof while a distance between an object and the image is kept constant. Image formation characteristics of the overall lens system are adjusted by moving and/or decentering the first group and/or the fourth group on/from the optical axis.

Abstract: An image forming apparatus includes image forming device for forming an unfixed image on a recording material; a fixing device for fixing the unfixed image on the recording material, the fixing device including a heater which is stationary in use, a film in sliding contact with the heater and a pressing member cooperative with the film to form a nip for receiving the recording material, and an opening portion for opening the apparatus for permitting jam clearance operation of the recording material in the fixing device. The pressing member and the film are separated from each other in association with opening of the opening portion.

Abstract: A rotatable stirring member for stirring a developer for conveying the developer is provided within a receptacle housing the developer. The stirring member can be subjected to elastically twisted deformation so that a shaft portion at the side of one end for receiving a rotation driving force can rotate in a phase which is advanced from that of a shaft portion at the side of another end.