| 摘要 |
PURPOSE: An optical device for a projector is provided so that an optical loss can be minimized near a projection lens and a projection screen can have homogeneous brightness, by providing a horizontal direction property to a projected optical beam by adding a glass bead to an optical projection surface of a cathode ray tube or field emission display. CONSTITUTION: A glass bead(25) for providing a direction property to light is added into a front surface glass(26) on a fluorescent surface(24) of a cathode ray tube. In the case that a field emission display is used as a light source, the glass bead(25) is added into a front surface glass of the field emission display. Here, the light generated from the fluorescent surface(24) by the glass bead(25) has the direction property. In addition, a linear polarization converting unit converts an incident beam of a projection side of the field emission display into linear polarization elements. A linear polarization plate is used to intercept non-linear polarization elements from the optical beams from the linear polarization converting unit. Accordingly, the light from the fluorescent surface(24) is not emitted in all directions but in a horizontal direction vertical to the fluorescent surface(24). Therefore, the optical beams from the cathode ray tube(22) have the horizontal direction property, and are all incident on a projection lens, thus minimizing an optical loss in adjacent portions of the projection lens.
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