Abstract: A feeding device includes: a sheet material housing configured to allow a plurality of sheet materials to be stacked; an upper surface suction unit that sucks a top sheet material by generating negative pressure at a position facing the upper surface of the top sheet material; a sheet material conveying unit that causes the top sheet material, which is sucked up, to be sucked onto a conveying member and conveys the top sheet material; and a lower suction unit that exerts a suction force downward onto the sheet materials that are positioned near the top sheet material, wherein a suction force exerted on the top sheet material downward by suction of the lower suction unit is smaller than a suction force exerted on the top sheet material upward by suction of the upper surface suction unit and is larger than adhesion between the sheet materials.

Abstract: A feeding device includes: a sheet material housing configured to allow a plurality of sheet materials to be stacked; an upper surface suction unit that sucks a top sheet material by generating negative pressure at a position facing the upper surface of the top sheet material; a sheet material conveying unit that causes the top sheet material, which is sucked up, to be sucked onto a conveying member and conveys the top sheet material; and a lower suction unit that exerts a suction force downward onto the sheet materials that are positioned near the top sheet material, wherein a suction force exerted on the top sheet material downward by suction of the lower suction unit is smaller than a suction force exerted on the top sheet material upward by suction of the upper surface suction unit and is larger than adhesion between the sheet materials.

Abstract: A hydrodynamic bearing unit using oil includes a shaft to be driven, a bearing member configured to support the shaft in a non-contact manner through a bearing gap by a hydrodynamic pressure of the oil, which is generated in the bearing gap while the shaft relatively rotate with respect to the bearing member, a housing configured to house the bearing member and having an opening at one end thereof, another end thereof being enclosed, a sealing member configured to seal a part of the opening of the housing, a channel configured to communicate a space formed between the shaft, the bearing member and the housing with an outside air, and a pressing member configured to press and fix the bearing member on the housing. At least one open part configured to release an air bubble contained in the housing is provided between the bearing member and the sealing member.

Abstract: A hydrodynamic bearing unit using oil includes a shaft to be driven, a bearing member configured to support the shaft in a non-contact manner through a bearing gap by a hydrodynamic pressure of the oil, which is generated in the bearing gap while the shaft relatively rotate with respect to the bearing member, a housing configured to house the bearing member and having an opening at one end thereof, another end thereof being enclosed, a sealing member configured to seal a part of the opening of the housing, a channel configured to communicate a space formed between the shaft, the bearing member and the housing with an outside air, and a pressing member configured to press and fix the bearing member on the housing. At least one open part configured to release an air bubble contained in the housing is provided between the bearing member and the sealing member.

Abstract: An optical deflector, a method of producing the optical deflector, an optical scanning device, and an image forming apparatus are disclosed that are able to save resources, provide high reliability at low cost, and enable stacked and relatively-offset polygon mirrors to be arranged precisely. The optical deflector includes a rotary member supported by a bearing with plural polygon mirrors fixed thereon. The polygon mirrors are stacked along a rotation axis of the rotary member, the polygon mirrors are relatively offset by a predetermined angle in a rotation plane of the rotary member, and an effective deflection area of each of the reflection surfaces of any one of the polygon mirrors is positioned away from a center of the corresponding reflection surfaces of the other one of the polygon mirrors in the direction of the rotation axis.

Abstract: Disclosed is a polygon mirror scanner device, used as a rotor, having a plurality of mirror faces on the outer peripheral face of a mirror member having a substantially tubular shape, with a tubular magnet adhered to the lower inner peripheral face of the mirror member. A depression is uniformly formed in the circumferential direction on the inner peripheral face, at a position opposite the mirror faces, such that a gap forms between the magnet and the inner peripheral face when the magnet is at a predetermined positioned. An adhesive agent is provided at the upper end and lower end of the magnet, but not in the gap. When the mirror faces are two-tiered, the upper end of the magnet is located at substantially an intermediate position in the height direction of the two-tier mirror faces.

Abstract: An optical deflector, a method of producing the optical deflector, an optical scanning device, and an image forming apparatus are disclosed that are able to save resources, provide high reliability at low cost, and enable stacked and relatively-offset polygon mirrors to be arranged precisely. The optical deflector includes a rotary member supported by a bearing with plural polygon mirrors fixed thereon. The polygon mirrors are stacked along a rotation axis of the rotary member, the polygon mirrors are relatively offset by a predetermined angle in a rotation plane of the rotary member, and an effective deflection area of each of the reflection surfaces of any one of the polygon mirrors is positioned away from a center of the corresponding reflection surfaces of the other one of the polygon mirrors in the direction of the rotation axis.

Abstract: Disclosed is a polygon mirror scanner device, used as a rotor, having a plurality of mirror faces on the outer peripheral face of a mirror member having a substantially tubular shape, with a tubular magnet adhered to the lower inner peripheral face of the mirror member. A depression is uniformly formed in the circumferential direction on the inner peripheral face, at a position opposite the mirror faces, such that a gap forms between the magnet and the inner peripheral face when the magnet is at a predetermined positioned. An adhesive agent is provided at the upper end and lower end of the magnet, but not in the gap. When the mirror faces are two-tiered, the upper end of the magnet is located at substantially an intermediate position in the height direction of the two-tier mirror faces.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

Abstract: The current invention is directed to a high-speed optical deflector which includes a brushless motor operating in a high-temperature environment. The brushless motor components include rotatable parts made of various materials whose thermal expansion coefficients significantly vary. These rotational components include a steel rotor flange, a magnet rotor, and an aluminum shaft. To substantially eliminate rotational imbalance or vibration caused by the thermal expansion, the above described components are fixed with a certain adhesive which prevents these components from causing the rotational imbalance. A certain heat-resistant adhesive provides a sufficient structural strength to substantially minimize a rotational imbalance caused by the thermally expanding components in an operating temperature range.