Relay system and projector

A projector comprising:

• a relay system that couples an enlargement-side image formation plane at an enlargement side to a reduction-side image formation plane at a reduction side, the reduction-side image formation plane being a reduced version of the enlargement-side image formation plane, the relay system comprising:
• a first lens group formed of a plurality of lenses and having positive power;
• a second lens group including a diaphragm and at least one negative lens and having negative power;
• and a third lens group formed of a plurality of lenses and having positive power, the first lens group, the second lens group and the third lens group being sequentially arranged in a direction in which beams travel from the enlargement side toward the reduction side,
• wherein a number of lenses of the first lens group and a number of lenses of the third lens group are equal to each other,
• an arrangement of lens power of the plurality of lenses of the first lens group, which are arranged from the enlargement side toward the reduction side, is the same as an arrangement of lens power of the plurality of lenses of the third lens group, which are arranged from the reduction side toward the enlargement side, and
• enlargement-side and reduction-side portions of the relay system are telecentric portions;
• a light source;
• a color separation system that separates white light output from the light source into first color light having a first wavelength band containing blue light and other color light having a wavelength band longer than the first wavelength band;
• a first light modulator that modulates the first color light separated by the color separation system;
• a second light modulator that modulates the other color light separated by the color separation system;
• the relay system, in which the first light modulator is disposed at the enlargement-side image formation plane and which reduces a luminous flux width of the first color light modulated by the first light modulator to a size of the reduction-side image formation plane;
• a light combining prism that combines the first color light the luminous flux width of which is reduced by the relay system and the other color light modulated by the second light modulator with each other into combined light and outputs the combined light;
• and
• a projection system that projects the combined light output from the light combining prism,
• wherein an effective area of the first light modulator is larger than an effective area of the second light modulator,
• the relay system includes a first planar mirror disposed between the enlargement-side image formation plane and the first lens group, and a second planar mirror disposed between the third lens group and the reduction-side image formation plane,
• the first and second planar mirrors each deflect the beams,
• an optical axis of the enlargement-side image formation plane and an optical axis of the reduction-side image formation plane are parallel to each other, and
• a direction in which the first color light is incident on the enlargement-side image formation plane is opposite a direction in which the first color light exits via the reduction-side image formation plane.

A projector comprising:

• a relay system that couples an enlargement-side image formation plane at an enlargement side to a reduction-side image formation plane at a reduction side, the reduction-side image formation plane being a reduced version of the enlargement-side image formation plane, the relay system comprising:
• a first lens group formed of a plurality of lenses and having positive power;
• a second lens group including a diaphragm and at least one negative lens and having negative power;
• and a third lens group formed of a plurality of lenses and having positive power, the first lens group, the second lens group and the third lens group being sequentially arranged in a direction in which beams travel from the enlargement side toward the reduction side,
• wherein a number of lenses of the first lens group and a number of lenses of the third lens group are equal to each other,
• an arrangement of lens power of the plurality of lenses of the first lens group, which are arranged from the enlargement side toward the reduction side, is the same as an arrangement of lens power of the plurality of lenses of the third lens group, which are arranged from the reduction side toward the enlargement side, and
• enlargement-side and reduction-side portions of the relay system are telecentric portions;
• a light source;
• a color separation system that separates white light output from the light source into first color light having a first wavelength band containing blue light and other color light having a wavelength band longer than the first wavelength band;
• a first light modulator that modulates the first color light separated by the color separation system;
• a second light modulator that modulates the other color light separated by the color separation system;
• the relay system, in which the first light modulator is disposed at the enlargement-side image formation plane and which reduces a luminous flux width of the first color light modulated by the first light modulator to a size of the reduction-side image formation plane;
• a light combining prism that combines the first color light the luminous flux width of which is reduced by the relay system and the other color light modulated by the second light modulator with each other into combined light and outputs the combined light;
• and
• a projection system that projects the combined light output from the light combining prism,
• wherein an effective area of the first light modulator is larger than an effective area of the second light modulator,
• the relay system includes a first planar mirror disposed between the enlargement-side image formation plane and the first lens group, and a second planar mirror disposed in the first lens group,
• the first and second planar mirrors each deflect the beams,
• an optical axis of the enlargement-side image formation plane and an optical axis of the reduction-side image formation plane are parallel to each other, and
• a direction in which the first color light is incident on the enlargement-side image formation plane is opposite a direction in which the first color light exits via the reduction-side image formation plane.