An optical apparatus includes: a light source including multiple light-emitting points arrayed in a first direction; and an imaging optical system including multiple lens optical systems arrayed in the first direction. The imaging optical system forms images of the multiple light-emitting points on a light-receiving surface. In a first cross-section and in a second cross-section, half-value of a maximum value of angle of divergence of an imaging optical flux input to the light-receiving surface, resolution, and a size of each image of the plurality of light-emitting points formed on the light-receiving surface, satisfy predetermined conditions.

An image reading device includes a transport unit that transports a medium along a transport path, a sensor unit that is disposed on the transport path and reads an image of the transported medium, and a pressing unit that presses the sensor unit toward the transport path facing the sensor unit. The sensor unit includes a lens array having an elongated shape, a base frame that supports the lens array, and a cover portion that engages with the base frame and covers the lens array. The pressing unit abuts against the cover portion and presses the cover portion toward the transport path, from an abutting portion of the pressing unit that abuts against the cover portion. The base frame and the cover portion are separated from each other in a pressing direction in which the pressing unit presses the cover portion.

An optical scanner is provided with a light source, a deflector, an optical element, an imaging lens, a fixing structure, and a housing. The optical element has a reflecting surface. The fixing structure has a first support wall, a second support wall and a biasing member. The first support wall has a support projection with a tip part protruding along a thickness direction toward a rear surface and abutting on the rear surface, and an inclined surface extending from a tip part to a side opposite to the second support wall. A first angle between a first straight line extending in the perpendicular direction orthogonal to a bottom surface of the housing and a surface of the optical element is smaller than a second angle between the first straight line and the inclined surface. The second angle is less than 90 degrees.

An optical line sensor reads an inspection object conveyed in a sub-scanning direction by a reading line L extending in a main scanning direction and includes a plurality of light-receiving lenses 11 and a plurality of light-receiving elements. The plurality of light-receiving lenses 11 are arranged along the main scanning direction. The plurality of light-receiving elements are arranged linearly along the main scanning direction, and receive light transmitted through the plurality of light-receiving lenses 11. The plurality of light-receiving lenses 11 are arranged to be separated from each other by a diameter of the light-receiving lens 11 or longer. A plurality of light-receiving elements 121 form at least one row or more of the reading lines L.