Patent ID: 7894702

Claim:
A method of obtaining directivity in an optical waveguide, the method comprising the steps of: falling incident light on at least one of diffuse reflection members that are opposed with each other and are arranged at a center portion of the optical waveguide into which the light is propagated; generating a first table relative to an amount of emitted light that is acquired at a circumference of the optical waveguide by controlling at least one of an image control factor that is used for changing an image of the light which is incident to the diffuse reflection members and a coordinate control factor that is used for changing coordinates of the light which is incident to the diffuse reflection member with at least one of the image and the coordinates of the light which is incident to the diffuse reflection members of the optical waveguide being changed; and generating a second table relative to a pattern of the light which is incident to the diffuse reflection member in the optical waveguide by seeking for a combination of the image and the coordinates of the light based on the generated first table, the combination presenting a desired distribution of the amount of the emitted light at the circumference of the optical waveguide.