Image display apparatus

Patent metadata

Field	Value
Publication number	US-9405125-B2
Application number	US-201414276828-A
Country	US
Kind code	B2
Filing date	May 13, 2014
Priority date	Nov 16, 2011
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

An image display apparatus capable of ensuring a wide view range is provided. The image display apparatus includes: an image display panel; a backlight located on a back surface side of the image display panel; prisms located between the image display panel and the backlight and configured to deflect incident light; a liquid crystal layer located between the image display panel and the backlight and configured to change a deflection direction of emitted light by changing a refractive index thereof according to a voltage applied thereto; a position detection section configured to detect a position of a user; and a control section configured to control the voltage applied to the liquid crystal layer, on the basis of information of the position of the user detected by the position detection section.

First claim

What is claimed is:

1. An image display apparatus comprising:
an image display panel;
a backlight device located on a back surface side of the image display panel;
a first optical element located between the image display panel and the backlight device and configured to deflect incident light;
a second optical element located between the image display panel and the backlight device and configured to change a deflection direction of emitted light by changing a refractive index thereof according to a voltage applied thereto;
a position detection section configured to detect a position of a user; and
a control section configured to control the voltage applied to the second optical element, on the basis of information of the position of the user detected by the position detection section, wherein:
the first optical element and the second optical element constitute a liquid crystal prism element,
in the liquid crystal prism element, the first optical element is composed of a plurality of prisms each having a triangular cross section and a ridge line extending in a first direction parallel to one side of the image display panel, the prisms being arranged between a pair of opposing substrates so as to be aligned in a second direction orthogonal to the first direction,
in the liquid crystal prism element, the second optical element is composed of a liquid crystal element which includes a liquid crystal layer formed between the plurality of the prisms and one of the opposing substrates, and electrodes provided on inner surfaces of the opposing substrates, and is configured to generate an electric field in a thickness direction thereof when a voltage is applied,
an entire planar region of the liquid crystal prism element is divided into a first region and a second region which are adjacent to each other in the second direction, and the cross sectional shape of each prism provided in the first region and the cross sectional shape of each prism provided in the second region are symmetrical to each other about a plane that is orthogonal to a display surface of the image display panel and passes through a boundary between the first region and the second region,
the first region of the entire planar region of the liquid crystal prism is configured to adjust left-eye light to one viewer, and
the second region of the entire planar region of the liquid crystal prism is configured to adjust right-eye light to the one viewer.

2. The image display apparatus according to claim 1 , wherein the backlight device includes:
a light guide plate having a pair of side surfaces and configured to guide light incident on the side surfaces, to an exit surface;
a first light source located so as to face one of the side surfaces; and
a second light source located so as to face the other of the side surfaces.

3. The image display apparatus according to claim 2 , wherein
an image signal for right eye and an image signal for left eye to which a parallax is provided are alternately inputted into the image display panel in a time division manner,
the first light source emits the right-eye light for displaying an image for right eye,
the second light source emits the left-eye light for displaying an image for left eye, and
the first light source and the second light source alternately light up in synchronization with switching between the image signal for right eye and the image signal for left eye.

4. The image display apparatus according to claim 1 , wherein:
each of the plurality of prisms of the first optical element has a triangular cross section having a first line, a second line and a third line,
the first line faces the second optical element and the third line faces the back light device,
the first line is longer than the third line and the third line is longer than the second line, and
all surfaces, each defined by the first line, of the plurality of prisms face the plane.

5. An image display apparatus comprising:
an image display panel;
a backlight device located on a back surface side of the image display panel;
a first optical element located between the image display panel and the backlight device and configured to deflect incident light;
a second optical element located between the image display panel and the backlight device and configured to change a deflection direction of emitted light by changing a refractive index thereof according to a voltage applied thereto;
a position detection section configured to detect a position of a user; and
a control section configured to control the voltage applied to the second optical element, on the basis of information of the position of the user detected by the position detection section, wherein:
the first optical element and the second optical element constitute a liquid crystal prism element,
in the liquid crystal prism element, the first optical element is composed of a plurality of prisms each having a triangular cross section and a ridge line extending in a first direction parallel to one side of the image display panel, the prisms being arranged between a pair of opposing substrates so as to be aligned in a second direction orthogonal to the first direction,
in the liquid crystal prism element, the second optical element is composed of a liquid crystal element which includes a liquid crystal layer formed between the plurality of the prisms and one of the opposing substrates, and electrodes provided on inner surfaces of the opposing substrates, and is configured to generate an electric field in a thickness direction thereof when a voltage is applied, and
an entire planar region of the liquid crystal prism element is divided into a first region and a second region which are adjacent to each other in the second direction, and the cross sectional shape of each prism provided in the first region and the cross sectional shape of each prism provided in the second region are symmetrical to each other about a plane that is orthogonal to a display surface of the image display panel and passes through a boundary between the first region and the second region,
the image display panel has a rectangular shape, shorter sides of which extend in the first direction, a first longer side of which extends in the second direction, and a second longer side of which extends in the second direction, and
the plane passes through a first midpoint of the first longer side of the rectangular shape of the image display panel and a second midpoint of the second longer side of the rectangular shape of the image display panel.

6. The image display apparatus according to claim 5 , wherein the backlight device includes:
a light guide plate having a pair of side surfaces and configured to guide light incident on the side surfaces, to an exit surface;
a first light source located so as to face one of the side surfaces; and
a second light source located so as to face the other of the side surfaces.

7. The image display apparatus according to claim 6 , wherein:
an image signal for right eye and an image signal for left eye to which a parallax is provided are alternately inputted into the image display panel in a time division manner,
the first light source emits illumination light for displaying an image for right eye,
the second light source emits illumination light for displaying an image for left eye, and
the first light source and the second light source alternately light up in synchronization with switching between the image signal for right eye and the image signal for left eye.

8. The image display apparatus according to claim 5 , wherein:
each of the plurality of prisms of the first optical element has a triangular cross section having a first line, a second line and a third line,
the first line faces the se

Assignees

• Panasonic Corp
• Panasonic Ip Man Co Ltd

Inventors

• Hayashi Katsuhiko
• Kasano Masahiro

Classifications

• G02B27/0093

  with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking · CPC title

• G02F1/1323

  Arrangements for providing a switchable viewing angle · CPC title

• G02F1/1347

  Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells · CPC title

• G06F3/005

  Input arrangements through a video camera · CPC title

• G02B30/24

  involving temporal multiplexing, e.g. using sequentially activated left and right shutters · CPC title