Optical device and head-mounted display device and imaging device equipped with the same

Patent metadata

Field	Value
Publication number	US-9857594-B2
Application number	US-201615009989-A
Country	US
Kind code	B2
Filing date	Jan 29, 2016
Priority date	Jan 29, 2015
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

An optical device includes a light-shielding layer and a microlens array. The light-shielding layer includes a plurality of openings. The microlens array is divided into a plurality of microlenses corresponding to the respective plurality of openings. A refractive index of the microlens array is variable so that light is incident on the microlenses is focused on the respective plurality of openings. A portion where light is focused includes a central position of the corresponding opening.

First claim

What is claimed is:

1. An optical device comprising:
a light-shielding layer including a plurality of openings; and
a microlens array divided into a plurality of microlenses corresponding to the respective plurality of openings, a refractive index of the microlens array being variable so that light is incident on the microlenses is focused on the respective plurality of openings, the microlens array comprising:
control electrodes formed so as to correspond to the openings for the respective microlenses;
a common electrode arranged opposite to the control electrodes; and
a liquid-crystal layer sealed between the common electrode and the control electrodes,
wherein a refractive index of the liquid-crystal layer is changed according to a voltage applied by the control electrodes and the common electrode,

wherein a portion where light is focused includes a central position of the corresponding opening.

2. The optical device according to claim 1 , wherein a direction of the light emitted from the plurality of microlenses and being incident on the respective plurality of openings is inclined to the direction perpendicular to the light-shielding layer.

3. The optical device according to claim 1 , wherein the refractive index for one of the plurality of microlenses being variable independently.

4. The optical device according to claim 3 , further comprising a tilt sensor configured to detect a tilt of the optical device,
wherein the refractive index is varied according to the tilt detected by the tilt sensor.

5. The optical device according to claim 1 , wherein the liquid-crystal layer is an ultraviolet-curing liquid-crystal layer, and alignment in the liquid-crystal layer is controlled by irradiation with ultraviolet rays.

6. The optical device according to claim 1 , wherein each of the openings has a circular shape, an elliptic shape, or a shape symmetric with reference to an array of the openings.

7. The optical device according to claim 1 , wherein each of the openings has an elliptic shape,
each of the control electrodes has an opening shaped to correspond to each of the openings, and
an alignment axis for liquid-crystal molecules in the liquid-crystal layer coincides with an elliptic minor axis of the opening in each of the control electrodes.

8. The optical device according to claim 1 , wherein the openings are arranged in a square array or a hexagonal array.

9. The optical device according to claim 1 , wherein the microlens array is a gradient index microlens array.

10. A head mounted display device comprising:
the optical device according to claim 1 ; and
a video panel formed at a back surface of the microlens array to allow image rays to enter the optical device.

11. An imaging device comprising:
the optical device according to claim 1 ; and
an image sensor configured to receive light beams emitted from the optical device.

12. The head mounted display device according to claim 10 , wherein the liquid-crystal layer is an ultraviolet-curing liquid-crystal layer, and alignment in the liquid-crystal layer is controlled by irradiation with ultraviolet rays.

13. The head mounted display device according to claim 10 , wherein each of the openings has a circular shape, an elliptic shape, or a shape symmetric with reference to an array of the openings.

14. The head mounted display device according to claim 10 , wherein the openings are arranged in a square array or a hexagonal array.

15. The head mounted display device according to claim 10 , wherein the microlens array is a gradient index microlens array.

16. The imaging device according to claim 11 , wherein the liquid-crystal layer is an ultraviolet-curing liquid-crystal layer, and alignment in the liquid-crystal layer is controlled by irradiation with ultraviolet rays.

17. The imaging device according to claim 11 , wherein each of the openings has a circular shape, an elliptic shape, or a shape symmetric with reference to an array of the openings.

18. The imaging device according to claim 11 , wherein the openings are arranged in a square array or a hexagonal array.

19. The imaging device according to claim 11 , wherein the microlens array is a gradient index microlens array.

Assignees

• Toshiba Kk

Inventors

• Kizu Yuko
• Kizaki Yukio
• Kwon Honam
• Ito Machiko
• Ueno Risako
• Kobayashi Mitsuyoshi
• Ishii Koichi
• Takayama Satoshi
• Nakanishi Tsutomu
• Sasaki Takashi
• Nonaka Ryosuke
• Tsuruyama Tomoya

Classifications

• G02B3/0056

  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

• G02B3/0087

  with index gradient · CPC title

• G02F1/29

  for the control of the position or the direction of light beams, i.e. deflection · CPC title

• H04N5/2254

  Electricity · mapped topic

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title