| Patent application number | Description | Published |
|---|
| 20080204842 | OPTICAL SCANNING DEVICE AND IMAGE FORMING APPARATUS - By setting elements within the range that predetermined conditions are satisfied, for example, so that a size of a rotating polygon mirror is minimized, the rotating polygon mirror is made compact while the eclipse of light beams in the main scanning direction is prevented. The cost reduction of an apparatus is thus realized. The compact rotating polygon mirror reduces the consumption energy and the amount of heat generated in its drive system. Deteriorations in various optical characteristics including an increase in spot diameter of the light beam by temperature variation, uneven scanning pitch, and sub-scanning direction variation in beam pitch are suppressed. | 08-28-2008 |
| 20080219601 | OPTICAL SCANNER AND IMAGE FORMING APPARATUS - An optical scanner includes a housing and an intermediate member that includes a first joining surface and a second joining surface. The first joining surface is attached to the housing and the second joining surface is attached to at least one optical element of any one of a first optical system and a second optical system. In a three-dimensional coordinate in which a first one of coordinate axes is a direction that is parallel to both the first joining surface and the second joining surface, a second range on the first coordinate axis corresponding to the second joining surface includes a center point of a first range on the first coordinate axis corresponding to the first joining surface. | 09-11-2008 |
| 20090141316 | IMAGE FORMING APPARATUS - A deflector deflects a light beam from a light source. A scanning optical system focuses the light beam deflected by the deflector. An image carrying member is located at a focal position of the light beam and includes a surface that is scanned in a main scanning direction with the light beam focused by the scanning optical system. One pixel of an image is formed by a plurality of light spots having different focal positions in at least a sub-scanning direction. At least one light spot from among the light spots is formed on the surface of the image carrying member at a scan timing different from those of rest of the light spots. | 06-04-2009 |
| 20090195636 | OPTICAL SCANNING DEVICE AND IMAGE FORMING APPARATUS - A pre-deflector optical system includes an isolator arranged on an optical path of a light beam from a light source. The isolator has a first surface with different light transmittances depending on a polarization state of an incident light beam on a first side close to the light source and a second surface imparting an optical phase difference of a ΒΌ wavelength to the incident light beam on a second side. A deflector deflects the light beam passed through the pre-deflector optical system. A rotation mechanism rotates the isolator around its optical axis. A holding member holds the light source and the isolator in a predetermined positional relationship. | 08-06-2009 |
| 20090314927 | OPTICAL SCANNING DEVICE, IMAGE FORMING APPARATUS, AND OPTICAL SCANNING METHOD - A surface-emitting laser array includes a plurality of surface-emitting laser devices arranged in an array. An optical system includes a plurality of optical devices to guide a light beam composed of lights emitted from the surface-emitting laser array to a target surface to be scanned. A light-intensity-control-device switching unit places one of light-intensity control devices having different light transmittances at a predetermined position in an optical path of the light beam. | 12-24-2009 |
| 20110012982 | OPTICAL SCANNING DEVICE AND IMAGE FORMING APPARATUS - An optical scanning device includes: a light source; an optical deflecting unit that deflects a light beam emitted from the light source to scan on a scanning surface in main-scanning direction; and a scanning optical system that includes a first scanning lens and a second scanning lens that converge the light beam that is deflected onto the scanning surface. Distance between an exit surface of the first scanning lens and an incident surface of the second scanning lens is shorter than distance between a deflection facet of the optical deflecting unit and an incident surface of the first scanning lens, an exit surface of the second scanning lens is nearer to the deflection facet than a midpoint between the deflection facet and the scanning surface, and an image-surface-side principal point of the scanning optical system in sub-scanning direction is nearer to the scanning surface than the midpoint. | 01-20-2011 |
| 20110052263 | OPTICAL SCANNER AND IMAGE FORMING APPARATUS - An optical scanner includes a light source including light emitters, an aperture member collimating light beams from the light source, a deflector deflecting the light beams passing through the aperture member, and a scanning optical system condensing the deflected light beams onto a scanned surface to optically scan the surface in a main-scanning direction. The scanning optical system includes a resin scanning system having at least one resin scanning lens. At least one folding mirror/sheet glass is disposed between a scanning lens nearest to the deflector in the resin scanning system and the scanned surface. At least one scanning lens in the resin scanning system has an uneven birefringence distribution with respect to a sub-scanning direction. An optical conjugate image of the aperture member is formed between a lens surface nearest to the deflector in the resin scanning system and a lens surface nearest to the scanned surface with respect to the sub-scanning direction. | 03-03-2011 |
| 20110122217 | OPTICAL SCANNER AND IMAGE FORMING APPARATUS - An optical scanning system for a K station includes a resin scanning lens and three reflecting mirrors. Two reflectance ratios are calculated: one being the reflectance ratio of a luminous flux traveling toward the scanning start position of a drum-shaped photosensitive drum and the other being the reflectance ratio of a luminous flux traveling toward the scanning end position of the photosensitive drum. The magnitude relation between the two reflectance ratios is such that the reflecting mirror has an inverse magnitude relation to that of the other reflecting mirrors. Moreover, the difference is calculated between the largest value and the smallest value of the reflectance ratio, where the reflectance ratio depends on the angle of deviation of the polygon mirror. The reflecting mirror has the largest difference among the three reflecting mirrors. | 05-26-2011 |
