Abstract: A sealing structure sealing a clearance between a base (1) having a storage part (11) and a cover (2) joined to the base (1) so as to close the storage part (11) through a gasket (4) formed of a rubber-like elastic material. The base (1) and the cover (2) comprise side peripheral surfaces (12a) and (22a) opposed to each other in a direction different from a joining direction with a screw member (3). The gasket (4) is integrally fitted onto the side peripheral surface (12a) of the base (1) (or the side peripheral surface (22a) of the cover (2)), and the seal surface (41a) of the gasket is closely fitted to the side peripheral surface (22a) of the cover (2) (or the side peripheral surface (12a) of the base (1)). Thus, the outer shell of a device formed of the base (1) and the cover (2) can be easily thinned and the cover (2) can be prevented from being nonuniformly deformed by the repulsion of the gasket (4).

Abstract: A sheet feeder provided with a feed roller having a circumferential surface portion and a cutout surface portion and capable of reliably feeding sheets regardless of the thickness and weight of the recording medium. The feed roller has a roller shaft extending from both side thereof. Each roller has an inner peripheral surface through which the roller shaft extends, and has an outer peripheral portion serving as a contact portion for contacting with a separation pad when the cutout surface portion is in confrontation with the pad. An annular space is provided between the inner peripheral surface of the roller and an outer peripheral surface of the roller shaft. A spacer is movable over the roller shaft and is insertable into and rectactable from the annular space. In the insertion position, a distance between an axial center of the roller shaft and the contact portion is increased. In the retracted position, the distance is decreased because of the urging of the separation pad toward the roller.

Abstract: A sheet feeder provided in an image forming device and includes a sheet feed roller, a pair of rollers provided at both ends of the sheet feed roller and rotatable independent of the sheet feed roller, and a separation pad provided in confronting relation to the sheet feed roller and the pair of rollers. The sheet feed roller has a circumferential surface portion and a cut-out surface portion. When the cut-out surface portion is opposite a sheet and the separating pad, outer peripheral surface portions of the pair of rollers contact the sheet at approximately the same level position that the circumferential surface portion of the feed roller contacts the sheet. This maintains the separating pad in approximately the same position.

Abstract: A sheet supply unit for use in an image forming device. The sheet supply unit includes a sheet supply roller rotatable in a rotational direction. The sheet supply roller has a circumferential surface both made of a resilient member. The circumferential surface has a first contacting portion and a last contacting portion. The first contacting portion has a width which increases in the rotational direction, and the last contacting portion has a width which decreases in the rotational direction. This enables a sheet to smoothly come into contact with and separated from the circumferential surface. Therefore, the sheet is prevented from being damaged by a sharp increase of pressing force. Also, redundant supply of sheets can be prevented.

Abstract: A paper cassette adapted to be removably mounted in a paper feed section of an image forming device. The paper cassette is generally constructed of a main frame and an auxiliary frame slidably engaged with the main frame. The auxiliary frame is moved forwardly or rearwardly relative to the main frame in accordance with a longitudinal size of the desired sheets of paper to be stored in the paper cassette. Thereafter, the auxiliary frame is fixedly positioned by a position adjusting member provided on the main frame. Thus, a longitudinal size or length of the paper cassette to be mounted into the paper feed section of the image forming device can be varied in accordance with a longitudinal size of the desired sheets of paper to be used, thereby reducing the types of paper cassettes required.

Abstract: An image forming apparatus in which probability of sheet jamming is reduced and jammed sheet can be easily removed. The apparatus is provided with a guide plate, a movable guide plate defining a sheet feed passage therebetween, and a first sheet feed roller. A detachable sheet cassette is provided for attachment to a main body portion of the apparatus. In the sheet cassette, are provided a second sheet feed roller and a leaf spring which urges the second sheet feed roller toward the first sheet feed roller when the sheet cassette is attached to the main body portion. The sheet feed passage is opened by pivotal movement of the movable guide plate when the sheet cassette is detached from the main body portion, to thereby facilitate removal of the jamming sheet from the sheet feed passage.