Display Device, Viewing Angle Control Device, and Electronic Apparatus

• US 20080316366A1
• Filed: 09/01/2005
• Published: 12/25/2008
• Est. Priority Date: 09/07/2004
• 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
• Granted Patent: US 7,834,834 B2
• Time in Patent Office: Days
• US Class Current: 348/705
• CPC Class Codes: G02F 1/1323 Arrangements for providing a switchable viewing angle
• 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. In the multiple image display mode, the display switch makes it possible that (a) the image displayed by the image display is seen from a front direction and (b) an image obtained by superimposing, onto the image displayed by the image display, a switching image formed by the display switch is seen from an oblique direction. The switching image is formed by providing, with at least one of a pair of transparent electrode films for applying a voltage to a liquid crystal layer, a patterning having an area larger than 50% of an area of a display screen.

Claims

1. A display device, comprising:

image display means for displaying an image; and

display switching means for electrically switching 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,

in the single image display mode, the display switching means allowing an image displayed by the image display means to be seen from any direction,

in the multiple image display mode, the display switching means (a) allowing an image displayed by the image display means to be seen from a front direction and (b) allowing an image obtained by superimposing, on an image displayed by the image display means, a switching image formed by the display switching means to be seen from an oblique direction,

the switching image including a transmission region and a non-transmission region, the transmission region having a proportion smaller than 50% of an entire display screen.

2. The display device as set forth in claim 1, wherein, the transmission region of the switching image has a proportion of not less than 20% and not more than 40% of the entire display screen.

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

the display switching means is a liquid crystal layer provided between a pair of substrates, and further includes (i) first polarizing means for causing linear polarized light having a fixed polarization direction to be incident on the display switching means and (ii) second polarizing means for extracting linear polarized light having a fixed polarization direction from light emitted from the display switching means;

the liquid crystal layer has liquid crystal molecules whose long axis direction 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 substrates;

the second polarizing means extracts linear polarized light emitted from the liquid crystal molecules;

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 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 substrates.

4. The display device as set forth in claim 3, wherein:

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

the switching image is formed in accordance with the shape of 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 (i) a liquid crystal layer provided between a pair of substrates and (ii) pattern electrodes through which a voltage is applied to the liquid crystal layer; and

a linear polarization plate provided on the liquid crystal element,

the liquid crystal element having liquid crystal molecules whose long axis direction is included in a surface defined by a transmission axis or an absorption axis of the linear polarization plate 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,

at least one of the pattern electrodes of the liquid crystal element being patterned so as to have an area of not less than 60% and not more than 80% of a region on which the incident light is incident.

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