Linear light source apparatus and image reading apparatus

摘要

A linear light source apparatus is provided, being configured to convert light emitted from one light emitting element to light extended linearly, and output thus converted light. There is a lens that diffuses light flux within a predetermined region including the optical axis of the light emitting element, out of the light incident from the light emitting element, at a predetermined diffusion angle in the second direction (x-direction). The light is made to converge with respect to the first direction (y-direction). This converts the light from one light emitting element to light extended linearly and outputs the converted light. As for the second direction (x-direction), it is possible to make the light flux sparse in the predetermined region, and in the region outside thereof, the light flux is rendered to be dense. Therefore, a distribution of light quantity in the longitudinal direction (x-direction) is implemented by controlling the light flux density, upon employing the linear light source apparatus as a light source of the image reading apparatus.

主权项

1. A linear light source apparatus comprising,
a light emitting element, and a lens configured to converge light being emitted from the light emitting element, with respect to a first direction, and output flat light flux being extended linearly in a second direction that is orthogonal to the first direction, wherein, the lens diffuses light flux in a predetermined region including an optical axis of the light emitting element, out of the light incident from the light emitting element, in the second direction at a predetermined diffusion angle, and the lens diffuses light flux in a region outside the predetermined region including the optical axis, at a diffusion angle smaller than the diffusion angle of the light flux in the predetermined region including the optical axis, thereby reducing an emitted light quantity at the optical axis of the lens to be lower than the emitted light quantity in the region outside the predetermined region including the optical axis, with respect to the second direction.