Line source unit and image input apparatus
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorToshio Matsumoto
Life of this patent
Estimating the term…
Abstract
A line source unit with a uniform light generation characteristic and an image input apparatus are provided. In the line source unit, only defective element(s) can be replaced. Light enters at the side portion of a light guiding member which is transparent and placed within a cover, and travels within the light guiding member undergoing total reflection. The light is then released to the outside of the member by reflecting the light at a light diffusing portion formed on a part of the light guiding member. Inner part of the cover which closely contacts with the light guiding member is partly black in color, within a predetermined range from light generation elements. With this construction, the line source unit provides a uniform light amount.
Claims20
A line source unit comprising a cover member, a light guiding member which is independent of said cover member, and which is transparent and is placed within the cover member, and a light source equipped to neighbor both the cover member and the light guiding member, wherein in said line source unit, light emitted by the light source undergoes total reflection to travel through said light guiding member and the light reflected by a light diffusing portion which is formed on the light guiding member is released to outside of the light guiding member via a predetermined facet of the light guiding member, said line source unit including:
- a first portion of an internal surface of the cover member being in close contact with the light guiding member and extending a predetermined range from said light source, said first portion being constructed to have a light reflection rate smaller than that of a second portion of said internal surface of said cover member excluding the first portion.
An image input apparatus for inputting an image using a line source unit, said line source unit comprising a cover member, a light guiding member which is independent of said cover member, and which is transparent and is placed within the cover member, and a light source equipped to neighbor both the cover member and the light guiding member, wherein in said line source unit, light emitted by the light source undergoes total reflection to travel through said light guiding member and the light reflected by a light diffusing portion which is formed on the light guiding member is released to outside of the light guiding member via a predetermined facet of the light guiding member, and wherein said line source unit including:
- a first portion of an internal surface of the cover member being in close contact with the light guiding member and extending a predetermined range from said light source, said first portion being constructed to have a light reflection rate smaller than that of a second portion of said internal surface of said cover member excluding the first portion.
Dependencies are inferred from the claim text.