Abstract: Provided is a platform door device which makes it possible to reduce the length of time for a replacement operation when a panel-shaped portion of a door is damaged. The platform door device comprises a door, and a driving mechanism for moving the door forwardly and backwardly to close and open a gate on a platform. The driving mechanism includes a motor, a rotation body adapted to be rotated by the motor, and a driven body adapted to be driven according to the rotation of the rotation body so as to move the door, and the door has a panel-shaped main body, and a base segment detachably joined to the main body and attached to the driven body.

Abstract: Provided is a platform door device which makes it possible to reduce the length of time for a replacement operation when a panel-shaped portion of a door is damaged. The platform door device comprises a door, and a driving mechanism for moving the door forwardly and backwardly to close and open a gate on a platform. The driving mechanism includes a motor, a rotation body adapted to be rotated by the motor, and a driven body adapted to be driven according to the rotation of the rotation body so as to move the door, and the door has a panel-shaped main body, and a base segment detachably joined to the main body and attached to the driven body.

Abstract: At start of rotation of a photosensitive drum, rotation of a developing roller caused by a developing/register rollers driver is kept stopped until a time required for a predetermined point on the photosensitive member, which was located at a charging position when charging thereof by a charging device was started, to reach a development position elapses, and thereafter the developing roller is rotated by the developing/register rollers driver. When the predetermined point on the photosensitive member, which was located at the developing position when at least rotation of the photosensitive member was started, passes the transfer position, a roller cleaning voltage having the same polarity as the charge polarity of toner is applied to a transfer roller.

Abstract: A developing device used in an electrophotographic apparatus has seal members fixedly disposed between both end portions of a developing roller and those portions of inner walls of a device casing which correspond to both end portions of the developing roller. The seal members are made of a material which can be charged by friction with the developing roller to have the same polarity as charged toner. The toner is blocked by the seal members and presented from entering end portions of the developing roller.

Abstract: In a developing device for developing an electrostatic latent image formed on a photosensitive member in an electrophotographic apparatus, a developing roller and a developing blade are formed such that the hardness of the surface of the developing blade is higher than the hardness of the surface of the developing roller by 30 degrees or more in JIS-A hardness. The developing blade deforms and bites into the developing roller. Accordingly, the developing roller can be brought into tight contact with the developing blade, and a great frictional force is applied to the toner passing between the developing roller and blade to fully charge the toner.

Abstract: A transfer device of a contact transfer method wherein a transfer power supply applies a predetermined transfer voltage to a transfer roller contacting the rear surface of a printing sheet, so that an electric field for causing the toner to be attracted by the transfer roller is generated. A lumped constant resistor is electrically inserted between the transfer roller and the transfer power supply. The lumped constant resistor has an electric resistance smaller than an equivalent electric resistance obtained when the whole transfer roller is regarded as one electric resistor. When the electric resistance of the printing sheet changes in accordance with a change in ambient environment, the voltage drop across the lumped constant resistor is changed to compensate for the change in electric resistance of the printing sheet.

Abstract: A developing device used in an electrophotographic apparatus has seal members fixedly disposed between both end portions of a developing roller and those portions of inner walls of a device casing which correspond to both end portions of the developing roller. The seal members are made of a material which can be charged by friction with the developing roller to have the same polarity as charged toner. The toner is blocked by the seal members and prevented from entering end portions of the developing roller.

Abstract: In an electrophotographic device, a main body is divided into a lower body and a swingable upper body. A process unit formed of at least a toner holder, a charger, and a developer is detachably mounted in the lower body. The position of the process unit (particularly, the photosensitive member) relative to the lower body (particularly, a member driving gear) is controlled by placing a shaft of the member through a groove in a side wall of the lower body at one end of the member, and by bringing a lower end of the side wall of the process unit supporting the member into contact with an upper end of a support member supporting the member driving gear. An exposure unit mounted in the upper body is positioned to the photosensitive member with a predetermined distance therebetween by bringing a contact portion of the exposure head into contact with the side wall of the lower body supporting the member.

Abstract: A developing device includes an agitator rotated in a toner hopper. The agitator has a rod portion. A first coil spring portion is wound around the first portion of the rod portion in a first direction. A second coil spring portion is wound around the second portion of the rod portion in a second direction. The first direction is opposite to the second direction.

Abstract: A toner pack for use in an electrophotographic apparatus is formed of a polypropylene resin containing 30 to 50 wt % calcium carbonate filler. This resin has a high deformability, and generates a small amount of heat at the time of incineration thereof. Thus, the used toner pack can be disposed of together with flammable products made of paper and/or wood. Further, at the time of disposal, it is possible to fold the used toner pack to reduce its size.

Abstract: A developing device includes a device body which has a toner reception port and supplies toner stored therein to a photosensitive member, a toner cartridge, which is detachably mounted in the device body in coincidence with the toner reception port, has a toner discharge port opposed to the toner reception port, and supplies toner stored therein to the device body through the ports, a sealing member which is mounted on the device body to surround the toner reception port and seals between the device body and the toner cartridge mounted in the device body, and a pressing mechanism which is provided on the toner cartridge and presses the toner cartridge on the sealing member when the toner cartridge is mounted in the device body.

Abstract: A structure and method for mounting recording units in an electrophotgraphic recording apparatus wherein collar members provided at both ends of a photosensitive drum or a sleeve are disposed to come into tight contact with the opposing sleeve or photosensitive drum to secure a uniform developing gap therebetween and wherein a developing unit opposed to a drum unit is pivotably supported at a longitudinal central point of the developing unit. Even when the photosensitive drum is biased in its central axis, the above pivotable movement of the developing unit enables the sleeve to flexibly follow the axis biasing movement and also enables the rotational axes of the photosensitive drum and sleeve to be kept in their parallel relation, whereby the uniform developing gap can be positively secured at all times along the longitudinal direction of the photosensitive drum, and this can contribute to the stable picture image recording operation.