US 8,941,800 B2Granted

Reflective image forming element and optical system

AssigneeSharp Kabushiki Kaisha

InventorsKentarou Imamura, Shigeto Yoshida, Takafumi Shimatani

Life of this patent

Estimating the term…

Loading patent…

Abstract

A reflective imaging element includes: a plurality of holes penetrating through the plate-like substrate along a thickness direction thereof; two orthogonally-disposed specular elements on inner walls of the plurality of holes; a first principal face on which light from an object is received; a second principal face parallel to the first principal face; and two taper elements opposing the two specular elements. The two taper elements each have a first side parallel to the first principal face, a second side orthogonal to the first principal face and to the first side, and a hypotenuse meeting the first and second sides and constituting an angle β with the second side. An angle constituted by a normal direction of the first principal face and an incident direction of light striking the first principal face defines an incident angle θ, such that, in a range of 0°<θ<90°, the angle β satisfies (90°−θ)/4≦β.

Claims7

Dependent claims

An optical system, comprising:

a reflective imaging element;
and
a display panel, wherein
the reflective imaging element, comprises:
a plate-like substrate;
a plurality of holes penetrating through the plate-like substrate along a thickness direction thereof;
two orthogonally-disposed specular elements on inner walls of the plurality of holes;
a first principal face on which light from the display panel is received;
and a second principal face parallel to the first principal face, wherein,
the first principal face has a plurality of first light-transmitting portions, and the second principal face has a plurality of second light-transmitting portions, an area of each of the plurality of first light-transmitting portions being larger than an area of each of the plurality of second light-transmitting portions;
each of the plurality of first light-transmitting portions is connected to a respective one of the plurality of second light-transmitting portions via a corresponding hole among the plurality of holes;
two taper elements opposing the two specular elements are comprised;
the two taper elements each have a first side which is parallel to the first principal face, a second side which is orthogonal to the first principal face and to the first side, and a hypotenuse which meets the first and second sides and constitutes an angle β with the second side;
and
an angle constituted by a normal direction of the first principal face and an incident direction of light striking the first principal face defines an incident angle θ, such that, in a range of 0°<θ<90°,
the angle β satisfies (90°−θ)/4≦β, and the light is reflected at least two times at the two taper elements.

13 more elements

An optical system comprising:

a reflective imaging element;
the reflective imaging element comprising:
a plate-like substrate;
a plurality of holes penetrating through the plate-like substrate along a thickness direction thereof;
two orthogonally-disposed specular elements on inner walls of the plurality of holes;
a first principal face on which light from a display panel is received;
and a second principal face parallel to the first principal face, wherein,
the first principal face has a plurality of first light-transmitting portions, and the second principal face has a plurality of second light-transmitting portions, an area of each of the plurality of first light-transmitting portions being larger than an area of each of the plurality of second light-transmitting portions;
each of the plurality of first light-transmitting portions is connected to a respective one of the plurality of second light-transmitting portions via a corresponding hole among the plurality of holes;
two taper elements opposing the two specular elements are comprised;
the two taper elements each have a first side which is parallel to the first principal face, a second side which is orthogonal to the first principal face and to the first side, and a hypotenuse which meets the first and second sides and constitutes an angle β with the second side;
and
an angle constituted by a normal direction of the first principal face and an incident direction of light striking the first principal face defines an incident angle θ, such that, in a range of 0°<θ<90°,
the angle β satisfies (90°−θ)/4≦β;
and the display panel disposed at the first principal face side,
the optical system causing an image displayed on a display surface of the display panel to form an image at a position of planar symmetry with respect to the reflective imaging element as a plane of symmetry, wherein,
the first and second light-transmitting portions of the reflective imaging element each have first and second sides orthogonal to each other;
ab>a′b′ holds, where a is a length of the first side and b is a length of the second side of the first light-transmitting portion, a′ is a length of the first side and b′ is a length of the second side of the second light-transmitting portion, and c is a height of the hole;
and
an incident angle θ constituted by a normal direction of the first principal face and an incident direction of light on the first principal face satisfies the following eq. (1) in a range of 0°<θ<90°
90
⁢
°
-
tan
-
1
(
c
a
′2
+
b
′
2
)
≦
θ
≦
90
⁢
°
-
tan
-
1
(
c
a
2
+
b
2
)
(
1
)

54 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/581,983Filed 25 Feb 2011
Priority: JP 2010-0446931 Mar 2010
Published: US 2012/0320322 A120 Dec 2012
Granted: 27 Jan 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G02B 17/002
Systems with reflecting surfaces, with or without refracting elements: arrays of reflective systems
G02B 5/12
Optical elements other than lenses: reflex reflectors
G02B 5/136
Reflex reflectors: plural reflecting elements forming part of a unitary body
G02B 30/56
The image being built up from image elements distributed over a three-dimensional [3D] volume, e.g. voxels: by projecting aerial or floating images