Illumination unit and display unit

An illumination unit comprising:

• an illumination optical system configured to generate linear illumination light formed by two-dimensionally arranging a plurality of linear illumination light beams or a plurality of point-like illumination light beams;
• and
• a reflective plate configured to reflect the linear illumination light,
• wherein the reflective plate is configured to reflect the linear illumination light to or close to a plane passing through a part that generates the linear illumination light and being perpendicular to a plane including the reflective plate,
• wherein the reflective plate generates reflected light focused on a focal point located on or near a line segment passing through the part that generates the linear illumination light and being parallel to a normal to the plane including the reflective plate, when a light component parallel to a plane perpendicular to the part that generates the linear illumination light, and
• wherein the reflective plate has a surface shape allowing the reflected light to be focused on a focal point at a position satisfying a following expression:
• H1/nr−W1≦H2≦H1/nr+W1
• where H1 is a distance between a first plane including a plurality of apexes formed on a top surface of the reflective plate and the part that generates the linear illumination light,
• H2 is a distance between the first plane and the position of the focal point,
• nr is a relative refractive index (n1/n2),
• n1 is a refractive index of a region between the first plane and the part that generates the linear illumination light,
• n2 is a refractive index of a region between the first plane and a reflective surface of the reflective plate, and
• W1 is a width of the part that generates the linear illumination light.

An illumination unit comprising:

• an illumination optical system configured to generate linear illumination light formed by two-dimensionally arranging a plurality of linear illumination light beams or a plurality of point-like illumination light beams;
• and
• a reflective plate configured to reflect the linear illumination light,
• wherein the reflective plate is configured to reflect the linear illumination light to or close to a plane passing through a part that generates the linear illumination light and being perpendicular to a plane including the reflective plate,
• wherein the reflective plate generates reflected light focused on a focal point located on or near a line segment passing through the part that generates the linear illumination light and being parallel to a normal to the plane including the reflective plate, when a light component parallel to a plane perpendicular to the part that generates the linear illumination light, and
• wherein the reflective plate has a surface shape allowing the reflected light to be focused on a focal point located at a position satisfying a following expression:
• H2=H1/nr
• where H1 is a distance between a first plane including a plurality of apexes formed on a top surface of the reflective plate and the part that generates the linear illumination light,
• H2 is a distance between the first plane and the position of the focal point,
• nr is a relative refractive index (n1/n2),
• n1 is a refractive index of a region between the first plane and the part that generates the linear illumination light, and
• n2 is a refractive index of a region between the first plane and a reflective surface of the reflective plate.

An illumination unit comprising:

• an illumination optical system configured to generate linear illumination light formed by two-dimensionally arranging a plurality of linear illumination light beams or a plurality of point-like illumination light beams;
• and
• a reflective plate configured to reflect the linear illumination light,
• wherein the reflective plate is configured to reflect the linear illumination light to or close to a plane passing through a part that generates the linear illumination light and being perpendicular to a plane including the reflective plate,
• wherein the reflective plate generates reflected light focused on a focal point located on or near a line segment passing through the part that generates the linear illumination light and being parallel to a normal to the plane including the reflective plate, when a light component parallel to a plane perpendicular to the part that generates the linear illumination light,
• wherein the reflective plate has, as a reflective surface, a part of an inner surface of a cylinder at a position facing the part that generates the linear illumination light, and
• wherein a radius r of a part corresponding to the part of the inner surface of the cylinder in the reflective surface satisfies a following expression:
• r=(H22+(P1/2)2)1/2
• where H2 is a distance between a first plane including a plurality of apexes formed on a top surface of the reflective plate and the position of the focal point, and
• P1 is a pitch of the part that generates the linear illumination light.

An illumination unit comprising:

• an illumination optical system configured to generate linear illumination light formed by two-dimensionally arranging a plurality of linear illumination light beams or a plurality of point-like illumination light beams;
• and
• a reflective plate configured to reflect the linear illumination light,
• wherein the reflective plate is configured to reflect the linear illumination light to or close to a plane passing through a part that generates the linear illumination light and being perpendicular to a plane including the reflective plate,
• wherein the reflective plate generates reflected light focused on a focal point located on or near a line segment passing through the part that generates the linear illumination light and being parallel to a normal to the plane including the reflective plate, when a light component parallel to a plane perpendicular to the part that generates the linear illumination light, and
• wherein the reflective plate has a surface shape where the reflected light is focused on a focal point located at a position satisfying a following expression (1), and has, as a reflective surface, a part of an inner surface of a cylinder at a position facing the part that generates the linear illumination light,
• a pitch of a cubic shape in the reflective surface is equal to a pitch of the part that generates the linear illumination light, and
• a radius r of a part corresponding to the part of the inner surface of the cylinder satisfies a following expression (2):
• H2=H1/nr (1)
• r=(H22+(P1/2)2)1/2 (2)
• where H1 is a distance between a first plane including a plurality of apexes formed on a top surface of the reflective plate and the part that generates the linear illumination light,
• H2 is a distance between the first plane and the position of the focal point,
• nr is a relative refractive index (n1/n2),
• n1 is a refractive index of a region between the first plane and the position of the focal point,
• n2 is a refractive index of a region between the first plane and the reflective surface of the reflective plate,
• P1 is a pitch of the part that generates the linear illumination light.