Illumination unit, display, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-9395578-B2
Application number	US-201214347719-A
Country	US
Kind code	B2
Filing date	Sep 4, 2012
Priority date	Oct 5, 2011
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

Provided is an illumination unit capable of utilizing back light. Also provided are a display and an electronic apparatus each including this illumination unit. A display includes a display panel, and an illumination unit configured to illuminate the display panel. The illumination unit includes a light-guiding plate, a diffusion modulation device, and a reflection modulation device in this order, from the display panel side. The light-guiding plate has a light source on a side face thereof. The diffusion modulation device is capable of performing modulation between a first state of diffusing light from the light source, and a second state of allowing incident light from a back face side to pass to a front face side. The reflection modulation device is capable of performing modulation between a third state of reflecting transmitted diffused light of the diffusion modulation device to a front face side, and a fourth state of allowing incident light from a back face side to the front face side.

First claim

The invention claimed is:

1. A display comprising:
a display panel; and
an illumination unit configured to illuminate the display panel,
the illumination unit including, in recited order, from a back side of the display panel,
a light-guiding plate having a light source on a side face thereof,
a diffusion modulation device being capable of performing modulation between a first state of diffusing light from the light source, and a second state of allowing incident light from a back face side to pass to a front face side, and
a reflection modulation device being capable of performing modulation between a third state of reflecting transmitted diffused light of the diffusion modulation device to a front face side, and a fourth state of allowing incident light from a back face side to the front face side,
each of the light-guiding plate, the diffusion modulation device, and the reflection modulation device being separate from each other, and
said reflection modulation device being directly adhered to the back face side of the diffusion modulation device without an air gap therebetween.

2. The display according to claim 1 , wherein the reflection modulation device performs the modulation electrically between the third state and the fourth state.

3. The display according to claim 1 , wherein the diffusion modulation device performs the modulation electrically between the first state and the second state.

4. The display according to claim 1 , wherein the reflection modulation device performs specular reflection of the transmitted diffused light of the diffusion modulation device in the third state.

5. The display according to claim 1 , wherein the diffusion modulation device includes an optical modulation layer in which liquid crystal molecules are dispersed in a polymer.

6. A display comprising:
a display panel; and
an illumination unit configured to illuminate the display panel,
the illumination unit including, in recited order, from a back side of the display panel,
a light-guiding plate having a light source on a side face thereof,
a diffusion modulation device being capable of performing modulation between a first state of diffusing light from the light source, and a second state of allowing incident light from a back face side to pass to a front face side, and
a reflection modulation device being capable of performing modulation between a third state of reflecting transmitted diffused light of the diffusion modulation device to a front face side, and a fourth state of allowing incident light from a back face side to the front face side,
wherein the diffusion modulation device includes an optical modulation layer in which liquid crystal molecules are dispersed in a polymer, and
wherein the reflection modulation device includes an optical modulation layer in which liquid crystal molecules are dispersed in a polymer, and performs diffuse reflection of the transmitted diffused light of the diffusion modulation device in the third state.

7. The display according to claim 6 , wherein a cloudiness degree of the reflection modulation device in the third state is greater than a cloudiness degree of the diffusion modulation device in the first state.

8. The display according to claim 1 , wherein an action state of each of the diffusion modulation device and the reflection modulation device is set,
to any of a combination of the first state of the diffusion modulation device and the third state of the reflection modulation device, a combination of the first state of the diffusion modulation device and the fourth state of the reflection modulation device, a combination of the second state of the diffusion modulation device and the third state of the reflection modulation device, and a combination of the second state of the diffusion modulation device and the fourth state of the reflection modulation device.

9. The display according to claim 1 , further comprising a drive section configured to drive the display panel and the illumination unit based on an image signal, wherein
the drive section is configured to synchronize the first state the diffusion modulation device and the third state of the reflection modulation device.

10. A display comprising:
a display panel;
an illumination unit configured to illuminate the display panel; and
a drive section configured to drive the display panel and the illumination unit based on an image signal,
the illumination unit including, in recited order, from a back side of the display panel,
a light-guiding plate having a light source on a side face thereof,
a diffusion modulation device being capable of performing modulation between a first state of diffusing light from the light source, and a second state of allowing incident light from a back face side to pass to a front face side, and
a reflection modulation device being capable of performing modulation between a third state of reflecting transmitted diffused light of the diffusion modulation device to a front face side, and a fourth state of allowing incident light from a back face side to the front face side,

wherein the drive section is configured to synchronize the first state of the diffusion modulation device and the third state of the reflection modulation device, and
wherein the drive section is configured to allow an image to appear on the display panel, by synchronizing the second state of the diffusion modulation device and the fourth state of the reflection modulation device, and gradually increasing a period of the first state of the diffusion modulation device and the third state of the reflection modulation device, while alternately repeating the first state of the diffusion modulation device as well as the third state of the reflection modulation device, and the second state of the diffusion modulation device as well as the fourth state of the reflection modulation device.

11. A display comprising:
a display panel; and
an illumination unit configured to illuminate the display panel,
the illumination unit including, in recited order, from a back side of the display panel,
a light-guiding plate having a light source on a side face thereof,
a diffusion modulation device being capable of performing modulation between a first state of diffusing light from the light source, and a second state of allowing incident light from a back face side to pass to a front face side,
an absorption modulation device, and
a reflection modulation device being capable of performing modulation between a third state of reflecting transmitted diffused light of the diffusion modulation device to a front face side, and a fourth state of allowing incident light from a back face side to the front face side

wherein the absorption modulation device is between the diffusion modulation device and the reflection modulation device, and
wherein the absorption modulation device is configured to perform modulation between a fifth state of absorbing light incident from the display panel side, and a sixth state of allowing the light incident from the display panel side to pass to the reflection modulation device side.

12. The display according to claim 1 , further comprising a drive section configured to drive the display panel and the illumination unit based on an image signal, wherein
the drive section is configured to synchronize the second state of the diffusion modulation device and the third state of the reflection modulation device.

13. A display comprising:
a display panel;
an illumination unit configured to illuminate the display panel; and
a drive section configured to drive the display panel and the illumination unit based on an image signal,

Assignees

• Furukawa Norimasa
• Okuyama Kentaro
• Sony Corp

Inventors

• Furukawa Norimasa
• Okuyama Kentaro

Classifications

• G09G2360/144

  the light being ambient light · CPC title

• G09G2300/0456

  with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels · CPC title

• G02F2203/62

  Switchable arrangements whereby the element being usually not switchable · CPC title

• G02F1/1334

  based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals · CPC title

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title