Image display device

Patent metadata

Field	Value
Publication number	US-2016154269-A1
Application number	US-201414898765-A
Country	US
Kind code	A1
Filing date	Aug 5, 2014
Priority date	Aug 5, 2013
Publication date	Jun 2, 2016
Grant date	—

Abstract

There is provided an image display device that includes a display in which a background is transparently seen from a front surface side, and has a high degree of freedom at the time of installation. A liquid crystal panel ( 32 ) for adjusting transparency/light-emission adjusts, for each pixel, a ratio between transmitted light-source light and ambient light by respectively controlling a polarization direction of a reflected polarization component of the light-source light irradiated to a reflection-type polarization plate ( 20 ) from a light guide plate ( 180 ) and a polarization direction of a transmitted polarization component of the ambient light incident to the reflection-type polarization plate ( 20 ) from a rear surface side of the display, based on transparent/light-emitting pixel information. Accordingly, when the image display device is viewed from the front surface side of the display, an image is seen for each pixel, a background is transparently seen, or the background is seen so as to be superimposed on the image. Since it is not necessary to attach the image display device to a case filled with light, the image display device is widely used without limitation of use.

First claim

1 . An image display device capable of performing transparent display in which a background is transparently seen from a front surface side of a display, the device comprising:
a light-source light/ambient light adjuster which includes a pixel array in which a plurality of pixels is arranged, controls a polarization direction of light for each pixel in response to an image signal applied from outside, and transmits light having a desired polarization component to the front surface side of the display; a polarization component selector which is disposed closer to a rear surface side than the light-source light/ambient light adjuster, selects one polarization component of ambient light incident from a rear surface side of the display to transmit the selected polarization component of the ambient light, selects a component of polarization components of light-source light incident from the front surface side of the display which is perpendicular to the polarization component of the ambient light to reflect the selected component of the light-source light, and guides the polarization components of the ambient light and the light-source light to the light-source light/ambient light adjuster; a light-source light irradiator which is disposed closer to the front surface side than the polarization component selector, and irradiates the light-source light toward the rear surface side of the display, wherein the image signal includes transparent/light-emitting pixel information for determining a ratio of transmission at which the ambient light which is incident from the rear surface of the display and is selected by the polarization component selector and the light-source light which is irradiated from the light-source light irradiator and is selected by the polarization component selector transmit through the light-source light/ambient light adjuster, and the light-source light/ambient light adjuster adjusts, for each pixel, a ratio at which the light-source light and the ambient light transmit by respectively controlling the polarization component of the ambient light selected by the polarization component selector and the polarization component of the light-source light selected by the polarization component selector, based on the transparent/light-emitting pixel information.

2 . The image display device according to claim 1 ,
wherein the polarization component selector includes a reflection-type polarization plate that transmits polarization components of the ambient light and the light-source light which have an identical polarization direction as a transmission axis direction, and reflects polarization components which have an identical polarization direction as a reflection axis direction, and the light-source light irradiator is disposed in a space interposed between the light-source light/ambient light adjuster and the reflection-type polarization plate or near the space, and irradiates the light-source light to the reflection-type polarization plate.

3 . The image display device according to claim 1 , further comprising:
a first absorption-type polarization plate that is disposed closer to the front surface side of the display than the light-source light irradiator; and a second absorption-type polarization plate that is disposed close to a front surface side of the light-source light/ambient light adjuster, and causes the polarization direction of the light-source light or the ambient light transmitted through the light-source light/ambient light adjuster to be in line with a polarization direction of the first absorption-type polarization plate, wherein the polarization component selector includes a reflection-type polarization plate that transmits polarization components of the ambient light and the light-source light which have an identical polarization direction as a transmission axis direction, and reflects polarization components which have an identical polarization direction as a reflection axis direction, the light-source light irradiator is disposed in a space interposed between the first absorption-type polarization plate and the second absorption-type polarization plate or near the space, and irradiates the light-source light to the second absorption-type polarization plate, and the first absorption-type polarization plate transmits at least any one of the light-source light and the ambient light transmitted through the second absorption-type polarization plate to the front surface side of the display, and absorbs light-source light which has leaked to the front surface side, of the light-source light irradiated from the light-source light irradiator.

4 . The image display device according to claim 1 ,
wherein the light-source light irradiator includes a light source that emits the light-source light including a plurality of polarization components having different polarization directions, the polarization component selector includes a polarization component selecting sheet that reflects the light-source light to the front surface side of the display at an angle different from an incident angle, a first polarization component selecting polarization plate that is disposed close to a rear surface side of the polarization component selecting sheet, and transmits polarization components having a specific polarization direction, of the ambient light incident from the rear surface side of the display, and a second polarization component selecting polarization plate that is disposed on a surface of the light source, and transmits a polarization component having a polarization direction, which is perpendicular to the specific polarization direction, of the light-source light emitted from the light source, and the light source is disposed near a space interposed between the light-source light/ambient light adjuster and the polarization component selecting sheet, and irradiates the polarization components of the light-source light, which have transmitted through the second polarization component selecting polarization plate, to the polarization component selecting sheet.

5 . The image display device according to claim 2 ,
wherein, on the display, a luminance of the light-source light transmitted through a first region set such that only the light-source light transmits, a luminance of the light-source light leaking to the front surface side from a second region set such that the light-source light does not transmit, and a luminance of the ambient light transmitting through a third region set such that only the ambient light transmits satisfy the following relationship:
Luminance of Light-source Light Transmitted through First Region>Luminance of Ambient Light Transmitted through Third Region>Luminance of Light-source Light Leaking from Second Region

6 . The image display device according to claim 1 , further comprising:
a transmittance adjuster which is disposed close to a front surface sided of the light-source light/ambient light adjuster, and adjusts transmittances of the light-source light and the ambient light transmitted through the light-source light/ambient light adjuster; and a first absorption-type polarization plate that is disposed close to a front surface side of the transmittance adjuster, wherein the polarization component selector includes a reflection-type polarization plate that transmits polarization components of the ambient light and the light-source light which have an identical polarization direction as a transmission axis direction, and reflects polarization components having an identical polarization direction as a reflection axis direction, the light-source light irradiator is disposed in a space interposed between the light-source light/ambient light adjuster and the reflection-type polarization plate or near the space, and irradiates polarization components o

Assignees

• Sharp Kk

Inventors

• Fukuoka Kenta
• Ishihara Tomoyuki
• Ake Yasunori

Classifications

• G09G3/36

  using liquid crystals · CPC title

• G02F1/13306

  Circuit arrangements or driving methods for the control of single liquid crystal cells (G02F1/132, G02F1/133382 take precedence) · CPC title

• G02F1/13471 Primary

  in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells (G02F1/13475 takes precedence) · CPC title

• G02F1/133536

  Reflective polarizers (G02F1/13362 takes precedence) · CPC title

• G02F1/13362

  providing polarized light, e.g. by converting a polarisation component into another one · CPC title