Because output power generally scales with output area, this increase in output area results in higher possible output powers.

Edges are a and b

Direction of observation

A reflective surface (S2) reflects the vieo image from the entrance surface (S1) to an exit surface (S3) wherein the user views the video image directly through the exit surface (S3).

A surface perpendicular to the light entrance surface serves as a light exit surface.

The light exit surface structural layer has an uneven structure on a surface on a device light exit surface side.

The lower step surface (14) is an out-light surface.

Screen (20) has an inlet screening surface (23) and an outlet surface (unlabled).

An optical coupler has an input surface and an output surface.

The prism further includes an exit surface (230) perpendicular to the sensing surface and the bottom surface, the exit surface for permitting the reflected light to exit from the prism.

The light reflecting surface (45) faces the light exiting surface (47).

The axis of the exit surface is the z-axis, the position of the bottom part of the illuminating lens is z=0, and the x and y axes are set in a plane perpendicular to the z-axis including z=0.

The area of the excitation light incident surface is larger than the area of the fluorescent light exit surface.

The light projected to the light-out surface (134) is ejected out of the lens (130) by the light-out surface.

At least one surface indicator is visible near the exit surface.