Patent ID: 6876408

Claim:
A collimating plate comprising: a lens substrate; a plurality of microlenses disposed on a surface of said lens substrate, from which collimated light issued; a plurality of light entrance areas disposed on another surface of said lens substrate, into which light is launched, each having a circular form, a center of which is on an optical axis of each of said plurality of microlenses and set on another surface of the lens substrate reverse to said plurality of microlenses; a light shield layer formed on said another surface of said lens substrate reverse to said plurality of microlenses so as to cover an area other than said plurality of light entrance areas; and a diffuse reflecting layer formed on a surface of said light shield layer at a light entrance side of said light shield layer so as to cover the area other than said plurality of light entrance areas, wherein when a refractive index of said lens substrate is represented by n; a thickness of said lens substrate by t; a diameter of each of said plurality of light entrance areas by R; and a size of each of said plurality of microlenses by Sr, the following formula (1): Sr≧ 2 t ×tan θ+ R (1) (with the proviso that θ=sin −1 (1/n)) is satisfied.