Light modulation element unit having a light modulating element and image projection apparatus for preventing foreign matters from adhering to light modulation element

An image projection apparatus comprising:

• a light modulation element unit comprising:
• a light modulation element having a light modulator configured to modulate incident light and a cover glass that covers a light incident surface of the light modulator and that has a first light incident surface facing the light incident surface of the light modulator and a second light incident surface positioned on an opposite side to the first light incident surface;
• a light shielding member disposed along the second light incident surface of the cover glass and has an opening through which light going toward the light modulator passes and a light shield to shield light that does not pass the opening;
• and
• a heat radiation member that is separate from the light shielding member provided on an opposite side of the cover glass with respect to the light modulation element,
• wherein the light shielding member further has an extension that extends to outside of the cover glass and that faces part of the heat radiation member with a first air gap,
• wherein the light shield is disposed along part of the second light incident surface of the cover glass with a second air gap,
• wherein the part of the second light incident surface of the cover glass is configured to communicate air through the first air gap and the second air gap, and
• wherein the first air gap is smaller than the second air gap;
• and
• an optical system configured to introduce light from a light source to the light modulation element, and project the light that is modulated by the light modulation element onto a target plane.

A light modulation element unit comprising:

• a light modulation element having a light modulator configured to modulate incident light and a cover glass that covers a light incident surface of the light modulator and that has a first light incident surface facing the light incident surface of the light modulator and a second light incident surface positioned on an opposite side to the first light incident surface;
• a light shielding member, which is disposed along the second light incident surface of the cover glass, and has an opening through which light going toward the light modulator passes and a light shield to shield light that does not pass the opening;
• and
• a heat radiation member that is separate from the light shielding member provided on an opposite side of the cover glass with respect to the light modulation element,
• wherein the light shielding member further has an extension that extends to outside of the cover glass and that faces part of the heat radiation member with a first air gap,
• wherein the light shield is disposed along part of the second light incident surface of the cover glass with a second air gap,
• wherein the part of the second light incident surface of the cover glass is configured to communicate air through the first air gap and the second air gap, and
• wherein a temperature gradient of the first air gap is larger than a temperature gradient of the second air gap.

An image projection apparatus comprising:

• a light modulation element unit comprising:
• a light modulation element having a light modulator configured to modulate incident light and a cover glass that covers a light incident surface of the light modulator and that has a first light incident surface facing the light incident surface of the light modulator and a second light incident surface positioned on an opposite side to the first light incident surface;
• a light shielding member disposed along the second light incident surface of the cover glass and has an opening through which light going toward the light modulator passes and a light shield to shield light that does not pass the opening;
• and
• a heat radiation member that is separate from the light shielding member provided on an opposite side of the cover glass with respect to the light modulation element,
• wherein the light shielding member further has an extension that extends to outside of the cover glass and that faces part of the heat radiation member with a first air gap,
• wherein the light shield is disposed along part of the second light incident surface of the cover glass with a second air gap,
• wherein the part of the second light incident surface of the cover glass is configured to communicate air through the first air gap and the second air gap, and
• wherein a temperature gradient of the first air gap is larger than a temperature gradient of the second air gap;
• and
• an optical system configured to introduce light from a light source to the light modulation element, and to project the light that is modulated by the light modulation element onto a target plane.