Illumination optical system and image projection apparatus

An illumination optical system capable of changing a light beam diameter in at least one of a first cross section and a second cross section orthogonal to each other, the first and second cross sections including an optical axis, the illumination optical system comprising:

• a light source;
• a condenser lens configured to concentrate light from the light source;
• a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident;
• a second fly-eye lens including a second lens cell corresponding to the first lens cell;
• and
• an image display element configured to display an image based on light from the second fly-eye lens,
• wherein the following relations are satisfied:
• (αX)/(βY)<0.9 or 1.1<(αX)/(βY), and
• 0.78<(αX)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in the first and second cross sections respectively, x and y are widths of a light emitting surface of the light source in the first and second cross sections respectively, D1x and D1y are widths of the first fly-eye lens in the first and second cross sections respectively, D2x and D2y are widths of the second fly-eye lens in the first and second cross sections respectively, and change rates α and β of the light beam diameters in the first and second cross sections respectively are defined as α=D2x/D1x and β=D2y/D1y.

An illumination optical system capable of changing a light beam diameter in at least one of a first cross section and a second cross section orthogonal to each other, the first and second cross sections including an optical axis, the illumination optical system comprising:

• a light source;
• a condenser lens configured to concentrate light from the light source;
• a rod integrator on which light concentrated by the condenser lens is incident;
• and
• an image display element configured to display an image based on light from the rod integrator,
• wherein the following relations are satisfied:
• (αX)/(βY)<0.9 or 1.1<(αX)/(βY), and
• 0.78<(αX)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in the first and second cross sections respectively, x and y are widths of a light emitting surface of the light source in the first and second cross sections respectively, D3x and D3y are widths of an exit surface of the rod integrator in the first and second cross sections respectively, D4x and D4y are widths of an entrance surface of the rod integrator in the first and second cross sections respectively, and change rates α and β of the light beam diameters in the first and second cross sections respectively are defined as α=D4x/D3x and β=D4y/D3y.

An image projection apparatus capable of changing a light beam diameter in at least one of a first cross section and a second cross section orthogonal to each other, the first and second cross sections including an optical axis, the image projection apparatus comprising:

• a light source;
• a condenser lens configured to concentrate light from the light source;
• a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident;
• a second fly-eye lens including a second lens cell corresponding to the first lens cell;
• a polarization conversion element configured to perform polarization conversion on light from the second fly-eye lens;
• and
• an image display element configured to display an image based on light from the polarization conversion element,
• wherein the following relations are satisfied:
• (αX/2)/(βY)<0.9 or 1.1<(αX/2)/(βY), and
• 0.78<(αX/2)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in the first and second cross sections respectively, x and y are widths of a light emitting surface of the light source in the first and second cross sections respectively, D1x and D1y are widths of the first fly-eye lens in the first and second cross sections respectively, D2x and D2y are widths of the second fly-eye lens in the first and second cross sections respectively, and change rates α and β of the light beam diameters in the first and second cross sections respectively are defined as α=D2x/D1x and β=D2y/D1y.

An illumination optical system comprising:

• a light emitting surface;
• a condenser lens configured to concentrate light from the light emitting surface;
• a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident;
• a second fly-eye lens including a second lens cell corresponding to the first lens cell;
• a polarization conversion element configured to perform polarization conversion on light from the second fly-eye lens;
• and
• an image display element configured to display an image based on light from the polarization conversion element,
• wherein the following relations are satisfied:
• (αX/2)/(βY)<0.9 or 1.1<(αX/2)/(βY), and
• 0.78<(αX/2)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in a first cross section and a second cross section respectively, the first and second cross sections are orthogonal to each other and include an optical axis of the illumination system, x and y are widths of the light emitting surface in the first and second cross sections respectively, D1x and D1y are widths of the first fly-eye lens in the first and second cross sections respectively, D2x and D2y are widths of the second fly-eye lens in the first and second cross sections respectively, and change rates α and β of a light beam diameters in the first and second cross sections respectively are defined as α=D2x/D1x and β=D2y/D1y.

An illumination optical system comprising:

• a light emitting surface;
• a condenser lens configured to concentrate light from the light emitting surface;
• a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident;
• a second fly-eye lens including a second lens cell corresponding to the first lens cell;
• and
• an image display element configured to display an image based on light from the second fly-eye lens,
• wherein the following relations are satisfied:
• (αX)/(βY)<0.9 or 1.1<(αX)/(βY), and
• 0.78<(αX)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in a first cross section and a second cross section respectively, the first and second cross sections are orthogonal to each other and include an optical axis of the illumination system, x and y are widths of the light emitting surface in the first and second cross sections respectively, D1x and D1y are widths of the first fly-eye lens in the first and second cross sections respectively, D2x and D2y are widths of the second fly-eye lens in the first and second cross sections respectively, and change rates α and β of a light beam diameters in the first and second cross sections respectively are defined as α=D2x/D1x and β=D2y/D1y.

An illumination optical system comprising:

• a light emitting surface;
• a condenser lens configured to concentrate light from the light emitting surface;
• a rod integrator on which light concentrated by the condenser lens is incident;
• and
• an image display element configured to display an image based on light from the rod integrator,
• wherein the following relations are satisfied:
• (αX)/(βY)<0.9 or 1.1<(αX)/(βY), and
• 0.78<(αX)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in a first cross section and a second cross section respectively, the first and second cross sections are orthogonal to each other and include an optical axis of the illumination system, x and y are widths of the light emitting surface in the first and second cross sections respectively, D3x and D3y are widths of an exit surface of the rod integrator in the first and second cross sections respectively, D4x and D4y are widths of an entrance surface of the rod integrator in the first and second cross sections respectively, and change rates α and β of a light beam diameters in the first and second cross sections respectively are defined as α=D4x/D3x and β=D4y/D3y.

An image projection apparatus comprising:

• a light emitting surface;
• a condenser lens configured to concentrate light from the light emitting surface;
• a first fly-eye lens including a first lens cell on which light concentrated by the condenser lens is incident;
• a second fly-eye lens including a second lens cell corresponding to the first lens cell;
• a polarization conversion element configured to perform polarization conversion on light from the second fly-eye lens;
• and
• an image display element configured to display an image based on light from the polarization conversion element,
• wherein the following relations are satisfied:
• (αX/2)/(βY)<0.9 or 1.1<(αX/2)/(βY), and
• 0.78<(αX/2)/(βY)×(y/x)<1.28,
• where X and Y are widths of the image display element in a first cross section and a second cross section respectively, the first and second cross sections are orthogonal to each other and include an optical axis of the illumination system, x and y are widths of the light emitting surface in the first and second cross sections respectively, D1x and D1y are widths of the first fly-eye lens in the first and second cross sections respectively, D2x and D2y are widths of the second fly-eye lens in the first and second cross sections respectively, and change rates α and β of a light beam diameters in the first and second cross sections respectively are defined as α=D2x/D1x and β=D2y/D1y.