Abstract: An image forming apparatus includes a main body, a cartridge support member configured to have a process cartridge provided with first electrical contact points attachable thereto, and a holder configured to have second electrical contact points which are electrically contactable to the first electrical contact points. When the cartridge support member is moved from a first position to a second position in the main body, the second electrical contact points are electrically connected to the first electrical contact points while the cartridge support member is at the first position, while the cartridge support member moves between the first position and the second position, and while the cartridge support member is at the second position. The holder electrically disconnects the second electrical contact points from the first electrical contact points when the cartridge support member is moved to a third position outside the main body.

Abstract: An image forming apparatus includes a main body, a cartridge support member configured to have a process cartridge provided with first electrical contact points attachable thereto, and a holder configured to have second electrical contact points which are electrically contactable to the first electrical contact points. When the cartridge support member is moved from a first position to a second position in the main body, the second electrical contact points are electrically connected to the first electrical contact points while the cartridge support member is at the first position, while the cartridge support member moves between the first position and the second position, and while the cartridge support member is at the second position. The holder electrically disconnects the second electrical contact points from the first electrical contact points when the cartridge support member is moved to a third position outside the main body.

Abstract: Provided is an electrophotographic image forming apparatus including a developing device attached to/detached from a main body; a memory unit provided in the developing device to transfer information related to the developing device to the main body, and a contact portion for connecting to the main body; and a connection portion provided in the main body, and connecting to the contact portion when the developing device is attached to the main body, wherein one of the connection portion and the contact portion has a first location, where the connection portion or the contact portion is inclined with respect to the first direction of the developing device, and a second location, where the connection portion or the contact portion is in parallel with the first direction.

Abstract: Provided is an electrophotographic image forming apparatus including a developing device attached to/detached from a main body; a memory unit provided in the developing device to transfer information related to the developing device to the main body, and a contact portion for connecting to the main body; and a connection portion provided in the main body, and connecting to the contact portion when the developing device is attached to the main body, wherein one of the connection portion and the contact portion has a first location, where the connection portion or the contact portion is inclined with respect to the first direction of the developing device, and a second location, where the connection portion or the contact portion is in parallel with the first direction.

Abstract: A light scanning unit includes a light source to emit a light beam; a polygonal mirror to deflect the light beam in a main scanning direction; and an imaging optical system to image the light beam onto a scanning surface. The polygonal mirror includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis and an internal mirror surface that defines a hole. A ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3. The polygonal mirror is adhered to a motor unit that supports and rotates the polygonal mirror, using an adhesive. The internal mirror surface of the polygonal mirror defining the hole is point-bonded to the motor unit using the adhesive, and the point-bonding is conducted in a direction toward a corner of the reflection surfaces.

Abstract: An image forming apparatus including a plurality of developers and optical scanners, each of the optical scanners having a light source and a light reflecting unit and forming an electrostatic latent image on a photo conductor of each of the developers. The optical scanners have the same focusing distance from the light source to the photo conductor. The light reflecting unit of one of the optical scanners is arranged at a position different from the light reflecting unit of another optical scanner, such that intervals between the developers vary. The plurality of developers include a yellow (Y) developer, a magenta (M) developer, a cyan (C) developer, and a black (K) developer. The optical scanners include a first optical scanner, which forms electrostatic latent images on two of the developers including the black (K) developer, and a second optical scanner, which forms electrostatic latent images on the other two developers.

Abstract: A light scanning unit, a method of detecting a failure of a synchronization signal, and an electrophotographic image forming apparatus using the light scanning unit are provided. The light scanning unit includes a synchronization sensor which receives a portion of a light beam that is emitted from a light source and then deflected and scanned from a light deflector, to detect a horizontal synchronization signal. A width of a light-receiving surface of the synchronization sensor in a main scanning direction varies along a sub scanning direction. The light scanning unit having the above-described structure determines a high quality or a failure of a synchronization signal by using a width of a horizontal synchronization signal detected in a test operation.

Abstract: A light scanning unit includes a light source to emit a light beam; a polygonal mirror to deflect the light beam in a main scanning direction; and an imaging optical system to image the light beam onto a scanning surface. The polygonal mirror includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis and an internal mirror surface that defines a hole. A ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3. The polygonal mirror is adhered to a motor unit that supports and rotates the polygonal mirror, using an adhesive. The internal mirror surface of the polygonal mirror defining the hole is point-bonded to the motor unit using the adhesive, and the point-bonding is conducted in a direction toward a corner of the reflection surfaces.

Abstract: A polygonal mirror, a light scanning unit using the polygonal mirror, and an image forming apparatus. The polygonal mirror is formed of a plastic and includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis, and an internal mirror surface that defines a hole, wherein a ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3.

Abstract: An optical unit includes an optical element having a first combining surface and a second combining surface that applied an adhesive that is cured when exposed to a curing light respectively and that have different transmittance of the curing light; and a mount member combined with the optical element by the adhesive. The adhesive is cured when exposed to the curing light.

Abstract: An image forming apparatus including a black developer with increased capacity. The image forming apparatus includes optical scanners, where the optical scanners have the same focusing distance from the light source to the photo conductor, and the light reflecting unit of one of the optical scanners is arranged at a position different from the light reflecting unit of another optical scanner, such that intervals between the developers vary. Accordingly, although developers of the same type are used, the capacity of the black developer, which is most frequently used, may be easily increased by arranging the relative positions of the developers.

Abstract: A light scanning unit that includes: a light source unit for emitting first and second light beams; a beam deflector for deflecting the first and second light beams emitted from the light source unit; synchronization detection sensors for detecting scanning synchronization of the first and second light beams; and synchronization optical path converting members to deflect the first and second light beams toward the synchronization detection sensors. The optical paths of the portions of the first and second light are directed to come into close proximity with one another. The light scanning unit may be incorporated in an image forming apparatus.

Abstract: A polygonal mirror, a light scanning unit using the polygonal mirror, and an image forming apparatus. The polygonal mirror is formed of a plastic and includes a plurality of reflection surfaces that are formed in an outer portion of the polygonal mirror and rotate around a rotational axis, and an internal mirror surface that defines a hole, wherein a ratio of an internal diameter d to an outer diameter D satisfies 0.1?d/D?0.3.

Abstract: An image forming apparatus including a black developer with increased capacity. The image forming apparatus includes optical scanners, where the optical scanners have the same focusing distance from the light source to the photo conductor, and the light reflecting unit of one of the optical scanners is arranged at a position different from the light reflecting unit of another optical scanner, such that intervals between the developers vary. Accordingly, although developers of the same type are used, the capacity of the black developer, which is most frequently used, may be easily increased by arranging the relative positions of the developers.

Abstract: A light scanning unit comprises: a light source unit for emitting first and second light; a beam deflector for deflecting the first and second light emitted from the light source unit; and a synchronization detection optical system. The synchronization detection optical system includes synchronization detection sensors for detecting scanning synchronization of the first and second light and synchronization optical path converting members for converting optical paths of portions of the first and second light deflected by the beam deflector. The optical paths of the portions of the first and second light are directed to come into close proximity with one another. The light scanning unit may be incorporated in an image forming apparatus.

Abstract: An optical unit includes an optical element having a first combining surface and a second combining surface that applied an adhesive that is cured when exposed to a curing light respectively and that have different transmittance of the curing light; and a mount member combined with the optical element by the adhesive. The adhesive is cured when exposed to the curing light.