Display device, viewing angle control device, and electronic apparatus

• US 7,817,106 B2
• Filed: 09/09/2005
• Issued: 10/19/2010
• Est. Priority Date: 09/15/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Fukushima, Hiroshi, Yabuta, Koji, Takatani, Tomoo
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Steinberg; Jeffrey S
• Application Number:
  US11/575,112
• Publication Number:
  US 20080316198A1
• Time in Patent Office: 1,866 Days
• Field of Search: 345/32, 345 4- 9, 349/96
• US Class Current: 345/32
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/13471 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

Abstract

A portable phone has a main LCD and a SW-LCD, provided on a path of light to be transmitted by the main LCD, which electrically switches between (i) an image to be seen in a single image display mode and (ii) an image to be seen in a multiple image display mode. Furthermore, a first polarization plate serving as a reflective polarization plate is provided between the SW-LCD and the main LCD, and a second polarization plate is provided on a front surface side of the SW-LCD. The SW-LCD has a liquid crystal layer to which a voltage is applied in the multiple image display mode. With this, an image displayed by an image display can be seen from a front direction. In addition, the image displayed by the image display means is blocked by the second polarization plate when the image is seen from the an oblique direction, and outside light from the oblique direction is reflected by the first polarization plate, so that a mirror surface display is carried out.

Claims

1. A display device, comprising:

image display device arranged to display an image; and

a display switching device, provided on a front surface side of the image display device, and arranged to electrically switch between (i) an image to be seen in a single image display mode in which a main image displayed by the image display device is viewable from both a front direction and an oblique direction and (ii) an image to be seen in a multiple image display mode in which the main image displayed is viewable from the front direction and an image different from the main image is viewable from the oblique direction;

wherein

the display switching device is a liquid crystal layer provided between a pair of substrates; and

the display switching device further includes (a) a first polarizing device provided between the display switching device and the image display device and (b) a second polarizing device provided on a front surface side of the display switching device, the first polarizing device being a reflective polarization plate.

2. The display device as set forth in claim 1, wherein:

the liquid crystal layer includes liquid crystal molecules whose long axis direction that is always substantially parallel or substantially perpendicular to a polarization direction of linear polarized light incident on the liquid crystal molecules, the long axis direction being a direction obtained when the liquid crystal molecules are projected from a direction perpendicular to the pair of substrates;

in the single image display mode, at least part of the liquid crystal molecules of the liquid crystal layer is oriented so as to have a long axis direction substantially parallel or substantially perpendicular to the pair of substrates; and

in the multiple image display mode, at least part of the liquid crystal molecules of the liquid crystal layer is oriented so as to have a long axis direction tilted with respect to the pair of substrates.

3. The display device as set forth in claim 1, wherein the first polarizing device includes an absorptive polarization plate further provided on a back surface side thereof.

4. The display device as set forth in claim 2, wherein:

at least one of the pair of substrates of the display switching device includes a pattern electrode including a specific shape; and

a direction of orientation of the liquid crystal molecules is changed in a region receiving a voltage applied to the pattern electrode.

6. An electronic apparatus, comprising a display apparatus as set forth in claim 1.

5. A viewing angle control device in which outputting is carried out by controlling a viewing angle of incident light, the viewing angle control device, comprising:

a liquid crystal element which includes a liquid crystal layer provided between a pair of substrates;

a first polarizing device provided on a back surface side of the liquid crystal element; and

a second polarizing device provided on a front surface side of the liquid crystal element;

wherein

the liquid crystal element includes liquid crystal molecules whose long axis direction is included in a plane defined by a transmission axis or an absorption axis of the first polarizer and the second polarizer and a light traveling direction;

the liquid crystal molecules being able to be (a) in a state of being substantially perpendicular or substantially parallel to the light traveling direction or (b) in a state of being tilted with respect to the light traveling direction;

the first polarizing device is a reflective polarization plate;

the viewing angle control device is arranged and programmed to operate in;

a first state in which a voltage is either applied or not applied such that the liquid crystal layer transmits light in both a front direction and an oblique direction; and

a second state, different from the first state, in which a voltage is either applied or not applied such that the liquid crystal layer transmits light in the front direction but does not transmit light in the oblique direction.

7. An electronic apparatus, comprising a viewing angle control device as set forth in claim 5.