Abstract: In a displacement sensor, an illumination optical system, which converts laser light emitted from an emission unit into first converging light, and irradiates with the first converging light a detection space through which a target moves. An imaging optical system converts laser light reflected from the target into second converging light, and irradiates with the second converging light a light-receiving surface of a detection unit. The image of the emission unit into which the illumination optical system focuses the first converging light is displaced along the optical axis of the imaging optical system by a temperature change of the illumination optical system. The range in which the image is displaced is limited to be located either anterior to the front principal point of the imaging optical system, or posterior to the rear principal point of the imaging optical system.

Abstract: In a displacement sensor, an illumination optical system, which converts laser light emitted from an emission unit into first converging light, and irradiates with the first converging light a detection space through which a target moves. An imaging optical system converts laser light reflected from the target into second converging light, and irradiates with the second converging light a light-receiving surface of a detection unit. The image of the emission unit into which the illumination optical system focuses the first converging light is displaced along the optical axis of the imaging optical system by a temperature change of the illumination optical system. The range in which the image is displaced is limited to be located either anterior to the front principal point of the imaging optical system, or posterior to the rear principal point of the imaging optical system.

Abstract: An optical scanning device comprises: photoreceptors corresponding one-to-one to solid colors; high-resolution light sources each emitting a set of beams irradiating the corresponding photoreceptor with a predetermined distance therebetween along a sub-scanning direction; a deflection unit; a first optical system directing the sets of beams from the high-resolution light sources to the deflection unit; a low-resolution light source emitting a set of beams irradiating a predetermined photoreceptor with a distance therebetween larger than the predetermined distance along the sub-scanning direction; and a second optical system directing all of the sets of beams to the corresponding photoreceptor.

Abstract: An optical scanning device comprises: photoreceptors corresponding one-to-one to solid colors; high-resolution light sources each emitting a set of beams irradiating the corresponding photoreceptor with a predetermined distance therebetween along a sub-scanning direction; a deflection unit; a first optical system directing the sets of beams from the high-resolution light sources to the deflection unit; a low-resolution light source emitting a set of beams irradiating a predetermined photoreceptor with a distance therebetween larger than the predetermined distance along the sub-scanning direction; and a second optical system directing all of the sets of beams to the corresponding photoreceptor.

Abstract: An optical scanning device in which optical beams from a light-emitting element are passed through a collimator lens and are deflected by a deflector and which scans over an image carrier by using the deflected optical beams, comprising: a device housing; and a holder supported on a base of the housing so as to be rotatable about an optical axis of the collimator lens, and penetrating through a through-hole in a side wall of the housing along the optical axis without contacting the side wall, wherein the holder includes first and second holder parts, the first holder part located inside the housing, and the second holder part located outside the housing, the collimator lens is held by the first holder part, the light-emitting element is held by the second holder part, and the optical beams pass through the through-hole in the side wall and reach the collimator lens.

Abstract: An image forming apparatus includes: an image carrier; a development unit for forming a toner image on the image carrier by supplying a toner contained in a developer reservoir to a latent image formed on the image carrier by means of a developer carrier; a transfer unit for transferring the toner image formed on the image carrier onto a transfer medium; a recovery unit for recovering the toner remaining on the image carrier after image transfer; a return unit for transporting the recover toner recovered by the recovery unit so as to return the recover toner into the developer reservoir of the development unit; and a separator/feeder for separating the toner contained in the developer reservoir from the recover toner thereby exclusively feeding the toner contained in the developer reservoir to the latent image formed on the image carrier by means of the developer carrier.

Abstract: An image forming apparatus includes: an image carrier; a development unit for forming a toner image on the image carrier by supplying a toner contained in a developer reservoir to a latent image formed on the image carrier by means of a developer carrier; a transfer unit for transferring the toner image formed on the image carrier onto a transfer medium; a recovery unit for recovering the toner remaining on the image carrier after image transfer; a return unit for transporting the recover toner recovered by the recovery unit so as to return the recover toner into the developer reservoir of the development unit; and a separator/feeder for separating the toner contained in the developer reservoir from the recover toner thereby exclusively feeding the toner contained in the developer reservoir to the latent image formed on the image carrier by means of the developer carrier.