Microlens array, image display apparatus, object apparatus, and mold

Patent metadata

Field	Value
Publication number	US-10534112-B2
Application number	US-201816230497-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Sep 28, 2016
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

A microlens array includes N lenses ranging from a 1 st lens to an N th lens and a lens arrangement area. N is a positive integer. The lens arrangement area has the N lenses arranged in array. The lens arrangement area receives light emitted from a light source. An i th (i being 1 st to N th ) lens satisfies a conditional expression below:

−20°≤θ≤20°
where θ denotes an angle formed by a main-axis orientation of double refraction and a reference orientation.

First claim

What is claimed is:

1. An apparatus comprising:
a light source to emit the light;
an image forming element to form an image with the light emitted from the light source; and
a microlens array comprising:
N lenses ranging from a 1 st lens to an N th lens, N being a positive integer; and
a lens arrangement area having the N lenses arranged in array, the lens arrangement area to receive light emitted from a light source,
at least one of the N lenses satisfying a conditional expression below:
−20°≤θ≤20°

where
θ denotes an angle formed by a main-axis orientation of double refraction and a reference orientation,
wherein at least a part of the lens arrangement area is irradiated with the light for forming the image.

2. The apparatus according to claim 1 ,
wherein the light-source unit includes a light source to emit the light that is linearly polarized, and
wherein the reference orientation is a polarization direction of the light for forming the image.

3. The apparatus according to claim 1 ,
wherein the light-source unit includes a plurality of light sources constituted by the light source and at least another light source,
wherein the light-source unit further includes a combiner to combine light beams emitted from the plurality of light sources into one light beam, and
wherein chromaticity coordinates over a whole area of an image, which are formed with light beams emitted from the plurality of light sources based on image data of a white color, fall within a circle having a radius of 0.015 and having a center at a center of the white color in a chromaticity coordinate system.

4. The apparatus according to claim 1 , further comprising:
a light emitter to project the light having passed through the microlens array; and
a transmission and reflection member to make the light projected from the light emitter viewable.

5. An object apparatus comprising:
the apparatus according to claim 4 ; and
an object equipped with the apparatus.

6. The object apparatus according to claim 5 ,
wherein the object is a mobile object, and
wherein the transmission and reflection member is a windshield mounted on the mobile object.

7. An apparatus comprising:
a light source to emit light, the light being polarized;
an image forming element to form an image with the light emitted from the light source; and
a screen having N lenses arranged in array, N being a positive integer, the screen having an optically effective area through which the light for forming the image passes, the N lenses ranging from a 1 st lens to an N th lens,
at least one of the N lenses of the screen satisfying a conditional expression below:
−20°≤θ≤20°

where
θ denotes an angle formed by a main-axis orientation of double refraction and a polarization direction of the light beam.

8. The apparatus according to claim 7 ,
wherein the screen includes a microlens array having a lens arrangement area including the N lenses, and
wherein the optically-effective area is at least a part of the lens arrangement area.

9. The apparatus according to claim 7 ,
wherein the light source includes a plurality of light sources,
wherein the light source further includes a combiner to combine light beams emitted from the plurality of light sources into one light beam, and
wherein chromaticity coordinates over a whole area of an image, which are formed with light beams emitted from the plurality of light sources based on image data of a white color, fall within a circle having a radius of 0.015 and having a center at a center of the white color in a chromaticity coordinate system.

10. The apparatus according to claim 7 , further comprising:
a light emitter to project the light having passed through the screen; and
a transmission and reflection member to make the light projected from the light emitter viewable.

11. A mold for producing a microlens array by injection molding comprising:
a lens section to form a lens arrangement area, in which a plurality of lenses are to be formed, of a microlens array; and
a gate section to let resin in the lens section,
the gate section having an inner wall that increases in width in a direction that approaches the lens section in a planar view.

12. The mold according to claim 11 ,
wherein the inner wall of the gate section has a maximum width that is less than or equal to a width of an edge on a side of the lens section which is adjacent to the gate section.

13. The mold according to claim 11 ,
wherein an inner wall of the lens section has a rectangular shape having, on a side of the gate section, an edge shorter than another edge in the planar view.

14. A microlens array molded using the mold according to claim 11 .

15. A method of displaying an image, comprising:
generating polarized light;
irradiating the polarized light through a screen including a plurality of lenses in an array;
displaying an image using the polarized light which has passed through the screen,
wherein each of the plurality of lenses satisfies:
−20°≤θ≤20°

where θ denotes an angle formed by a main-axis orientation of double refraction and a polarization direction of the polarized light.

Assignees

• Sakai Kohji
• Higuchi Miho
• Watanabe Jun
• Ricoh Co Ltd

Inventors

• Sakai Kohji
• Higuchi Miho
• Watanabe Jun

Classifications

• G03B21/2033

  LED or laser light sources · CPC title

• G03B21/625

  Lenticular translucent screens · CPC title

• G02B3/0037

  characterized by the distribution or form of lenses · CPC title

• G02B3/0043

  Inhomogeneous or irregular arrays, e.g. varying shape, size, height · CPC title

• G02B3/0056 Primary

  arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses (G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085) · CPC title