Display device, display system, display control method for same, electronic device, program, computer-readable recording medium, and light guide element

1. A display device, comprising:

a display panel including a display region in which pixels are aligned in at least one direction and a frame region which is a non-display region positioned outside the display region; and

a light guide element, positioned on a display surface of the display panel, for guiding a part of light emitted from the display region toward above the frame region so that an image on the display region is displayed above the frame region,

the light guide element including a plurality of light guide sections each including a transmissive layer and being parallel to each other,

the plurality of light guide sections being designed such that

an interface between adjacent ones of the plurality of light guide sections is inclined with respect to an incident surface and an emission surface of the light guide element so that an incident surface of at least a part of the plurality of light guide sections overlaps a part of the display region and an emission surface of said at least a part of the plurality of light guide sections overlaps at least a part of the frame region above which an image on the display region is to be displayed, and

when a distance between interfaces of adjacent ones of the plurality of light guide sections on the incident surface of the light guide element is referred to as a pitch p 1 , a distance between interfaces of adjacent ones of the plurality of light guide sections in a direction perpendicular to an optical transmission direction is referred to as a pitch p 11 , a pitch between pixels adjacent to the frame region above which an image on the display region is to be displayed is referred to as a pitch p 2 , an acute angle between a plane parallel to the display surface of the display panel and a borderline between adjacent ones of the plurality of light guide sections on a cross section of the light guide element in a normal direction is referred to as an inclination angle α, and m is a natural number,

in a case of P 1 >P 2 , a relation

( m+ 0.3)× p 2×sin α< p 11<( m+ 0.7)× p 2×sin α

being met, and

in a case of P 1 <P 2 , a relation

p 2×sin α/( m+ 0.7)< p 11< p 2×sin α/( m+ 0.3)

being met.

2. The display device as set forth in claim 1 , wherein a relation below is met,

α>sin −1 ( n 0 /n 1 )

where n 0 indicates an absolute refractive index of an air layer and n 1 indicates a relative refractive index of the transmissive layer in the light guide section which is relative to the absolute refractive index of the air layer.

3. The display device as set forth in claim 1 , wherein the light guide element has a plate shape and covers a whole of the display region of the display panel and at least a part of the frame region above which part an image on the display region is to be displayed.

4. A display system, comprising a plurality of display devices aligned on a single plane, each of the plurality of display devices being a display device as set forth in claim 3 .

5. An electronic device, comprising a display system as set forth in claim 4 , being foldable at an interface section between adjacent display devices.

6. The display device as set forth in claim 3 , wherein the light guide element in the display device is designed such that

an incident surface is parallel to the display surface of the display panel and an emission surface is inclined with respect to the display surface of the display panel in such a manner that a thickness of the light guide element is reduced toward an end of the incident surface which end is closer to the display region of the display panel,

the light guide element has a triangular pillar shape whose cross section in a direction perpendicular to the direction in which pixels adjacent to the frame region are aligned is a right triangle, and

the light guide element covers a part of the display region of the display panel and at least a part of the frame region above which an image on the display region is to be displayed.

7. A display system, comprising a plurality of display devices aligned on a single plane, each of the plurality of display devices being a display device as set forth in claim 6 .

8. An electronic device, comprising a display system as set forth in claim 7 , being foldable at an interface section between adjacent display devices.