| 摘要 |
PURPOSE:To obtain a stable color index signal even a screen is at a black level by mixing an UV laser beam and an infrared laser beam, irradiating/ scanning a screen with the mixed beam, and converting the infrared beam reflected by a reflector to an electric signal by a photodetector. CONSTITUTION:The UV laser beam generated from a light source 1 is made incident on a light modulator 12 and is modulated by a color image signal; moreover, the UV laser beam is made incident on a polarizing beam splitter PBS 19 through an expander 13 constituted of such as a concave lens and a focal lens. An IR laser beam and the UV laser beam which are made incident on the PBS 19 are polarized linearly. If the UV laser has P polarizing component and the IR laser beam S polarizing component, 100% of the P polarizing component of the UV laser beam passes through the PBS 19. S polarizing component of the IR laser beam is reflected by the boundary surface of the PBS 19 and becomes a mixed laser beam 16. The screen 4 is irradiated with the mixed laser beam 16. In this normal beam, the visible light phospher normally emits, and excitation corresponding to the black level is transmitted without affecting the visible light phospher at the black level. |
