Projection optical system, magnification projection optical system, magnification projection apparatus, and image projection apparatus

25:

• The magnification projection optical system as claimed in claim 24, comprising:
• a reflection optical system including a plurality of reflecting surfaces;
• and
• a transmission optical system including a plurality of transmitting surfaces.

28:

• The magnification projection optical system as claimed in claim 25, wherein:
• the reflecting surfaces of the reflection optical system have power and include at least one rotationally asymmetric reflecting surface;
• and
• the transmitting surfaces of the transmission optical system have refractive power and include at least one aspheric surface.

33:

• A magnification projection apparatus that:
• displays an image on an image display panel;
• illuminates the image display panel with light from a light source;
• and by a magnification projection optical system, guides a light beam from the image display panel to a screen in an upstream-downstream direction, projects the light beam from a direction inclined to a normal of the screen, and forms on the screen a magnified version of the image displayed on the image display panel, wherein:
• the magnification projection optical system comprises a reflection optical system and a transmission optical system;
• the reflection optical system includes a plurality of reflecting surfaces having power and includes at least one rotationally asymmetric reflecting surface;
• and
• the transmission optical system includes a transmitting surface having refractive power and includes at least one aspheric surface.

34:

• A magnification projection apparatus that:
• displays an image on an image display panel;
• illuminates the image display panel with light from a light source;
• and by a magnification projection optical system, guides a light beam from the image display panel to a screen in an upstream-downstream direction, projects the light beam from a direction inclined to a normal of the screen, and forms on the screen a magnified version of the image displayed on the image display panel, wherein:
• the magnification projection optical system comprises:
• a transmission optical system including a plurality of transmitting surfaces;
• a reflection optical system including a plurality of reflecting surfaces;
• and
• a diaphragm;
• and
• one of the reflecting surfaces, on which a light beam passing through the diaphragm is made incident first, has negative power.

35:

• A magnification projection apparatus that:
• displays an image on an image display panel;
• illuminates the image display panel with light from a light source;
• and by a magnification projection optical system, guides a light beam from the image display panel to a screen in an upstream-downstream direction, projects the light beam from a direction inclined to a normal of the screen, and forms on the screen a magnified version of the image displayed on the image display panel, wherein:
• a position and a shape of an intermediate image of the image display panel formed with negative magnification by light beams traveling from the image display panel to the screen are substantially identical to a position and a shape, respectively, of an intermediate image of the screen formed with negative magnification by light beams traveling from the screen to the image display panel.