Illumination unit and display unit
There are provided an illumination unit capable of reducing formation of a double image in three-dimensional display and a display unit including the same. 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 are included. The reflective plate reflects 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.
1. 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 a pitch of a cubic shape in the reflective surface is equal to a pitch of the part that generates the linear illumination light.
2. The illumination unit according to claim 1 , wherein the reflective plate has, directly below the part that generates the linear illumination light, a surface shape where the reflected light is focused.
3. The illumination unit according to claim 1 , 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:
H 1/ nr−W 1≦ H 2≦ H 1/ nr+W 1
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.
4. The illumination unit according to claim 1 , 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:
H 2= H 1/ 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.
5. The illumination unit according to claim 1 , 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.
6. The illumination unit according to claim 5 , 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 =( H 2 2 +( P 1/2) 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.
7. The illumination unit according to claim 1 , 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):
H 2= H 1/ nr (1)
r ( H 2 2 +( P 1/2) 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.
8. The illumination unit according to claim 1 , wherein
the illumination optical system includes a light guide plate, and
the reflective plate includes an adhesive layer allowing the reflective plate and a part or a whole of an outer edge of the light guide plate to be bonded together.
9. 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:
H 1/ nr−W 1≦ H 2≦ H 1/ nr+W 1
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.
10. The illumination unit according to claim 9 , wherein
the illumination optical system includes a light guide plate, and
the reflective plate includes an adhesive layer allowing the reflective plate and a part or a whole of an outer edge of the light guide plate to be bonded together.
11. 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:
H 2= H 1/ 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.
12. The illumination unit according to claim 11 , wherein
the illumination optical system includes a light guide plate, and
the reflective plate includes an adhesive layer allowing the reflective plate and a part or a whole of an outer edge of the light guide plate to be bonded together.
13. 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 =( H 2 2 +( P 1/2) 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.
14. The illumination unit according to claim 13 , wherein
the illumination optical system includes a light guide plate, and
the reflective plate includes an adhesive layer allowing the reflective plate and a part or a whole of an outer edge of the light guide plate to be bonded together.
15. 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):
H 2= H 1/ nr (1)
r =( H 2 2 +( P 1/2) 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.
16. The illumination unit according to claim 15 , wherein
the illumination optical system includes a light guide plate, and
the reflective plate includes an adhesive layer allowing the reflective plate and a part or a whole of an outer edge of the light guide plate to be bonded together.