Patent ID: 7717567

Claim:
A lighting optical system, comprising: a light separating means for separating incident light into three colored lights according to wavelength bands, and progressing the three separate colored lights for the same amount of distance from a light source of the incident light through different optical paths, and emitting the three separate colored lights; a first LCD, a second LCD and a third LCD for respectively receiving the three colored lights from the light separating means, forming images therefrom, and emitting the received three separate colored lights; and a light combining means for synthesizing the three separate colored lights emitted from the first LCD, the second LCD, and the third LCD, and outputting the synthesized light outside, wherein the light combining means comprises at least one triangle-shaped prism, wherein the light separating means includes light separation planes and emission planes and the light combining means includes incident planes, wherein at least two of the first LCD, the second LCD, or the third LCD, are located between the incident planes of the light combining means and the emission planes of the light separating means, wherein at least two of the first LCD, the second LCD, or the third LCD, are in contact with the incident planes and the emission planes, and wherein the light separating means comprises: a first parallelogram-shaped prism comprising a first inclined surface including a first color separating plane and the first parallelogram-shaped prism further comprising a second inclined surface including a total reflection plane, a second parallelogram-shaped prism comprising an inclined surface including a second color separating plane, and a first triangle-shaped prism.