Abstract: An optical system is provided which includes an illumination system with a light source, a lens member which guides light from the light source, and a mirror member; an image unit on which an image is formed and on which light from the illumination system is incident; a projection system which magnifies and projects the image formed on the image unit; and a blocking unit which is mounted to the mirror member of the illumination system and partially blocks light from the light source that is directed to the mirror member.

Abstract: A focus adjustment device for adjusting a focus state of a projection lens unit in an image projection apparatus is provided. The focus adjustment device includes a focus adjustment member rectilinearly movable in a first direction; a rotational shaft; a first movement-converting member for converting a rectilinear movement of the focus adjustment member into a rotary movement of the rotational shaft; and a second movement-converting member for converting the rotary movement of the rotational shaft into in a rectilinear movement of the projection lens unit along a focusing direction.

Abstract: A focus adjustment device for adjusting a focus state of a projection lens unit in an image projection apparatus is provided. The focus adjustment device includes a focus adjustment member rectilinearly movable in a first direction; a rotational shaft; a first movement-converting member for converting a rectilinear movement of the focus adjustment member into a rotary movement of the rotational shaft; and a second movement-converting member for converting the rotary movement of the rotational shaft into in a rectilinear movement of the projection lens unit along a focusing direction.

Abstract: An optical system is provided which includes an illumination system with a light source, a lens member which guides light from the light source, and a mirror member; an image unit on which an image is formed and on which light from the illumination system is incident; a projection system which magnifies and projects the image formed on the image unit; and a blocking unit which is mounted to the mirror member of the illumination system and partially blocks light from the light source that is directed to the mirror member.

Abstract: A light emitting diode (LED) module includes a plurality of LEDs which emit light, and a metal substrate on which the LEDs are mounted and which includes a fixing part to be directly fixed to an outer frame, wherein the metal substrate is a heat sink that absorbs heat generated by the LEDs.