Sharp Kabushiki Kaisha Corporation

Tohoku University

Katsunori Ehara

Yutaka Ishii

Tatsuo Uchida

Takahiro Ishinabe

Tohru Kawakami

Yoshito Suzuki

Yoshihiro Hashimoto

Yoshitaka Yamamoto

Yasuhisa Itoh

Kozo Nakamura

Toshiki Matsuoka

Kazuo Sekiya

Masahiro Nishizawa

David James Montgomery

Shuichi Kozaki

Shoichi Ishihara

Baku Katagiri

A lighting device () includes: a surface light source (); a first lens (L) having a first focal point (F), the first lens being provided on the light exit surface side of the surface light source; and a second lens (L) having a second focal point (F), the second lens being provided on a light exit surface side of the first lens, the surface light source, the first lens, and the second lens being configured such that a first virtual image (I) is formed by the first lens and a second virtual image (I) is formed by the second lens, wherein the first virtual image (I) is formed between the second focal point (F) and the first lens, and the second focal point (F) is on a side opposite to the light source side relative to a predetermined focal position f'.

Illumination device

To provide a thin optical sheet having improved efficiency for light utilization, an optical sheet () of one mode of the present invention includes, in sequence from a light entry side to a light emission side, a plurality of first prisms (), a &#xbc; wavelength plate (), and a polarized-light separating element (), the plurality of first prisms () each having (i) a first surface () through which light enters the first prism and (ii) a second surface () that reflects the light, having entered the first prism, toward the light emission side, the optical film further including, between the plurality of first prisms in an in-plane direction of the optical film, a second prism () that reflects light.

Optical film

A lighting device () includes: a surface light source (); a first lens (L) having a first focal point (F), the first lens being provided on the light exit surface side of the surface light source; and a second lens (L) having a second focal point (F), the second lens being provided on a light exit surface side of the first lens, the surface light source, the first lens, and the second lens being configured such that a first virtual image (I) is formed by the first lens and a second virtual image (I) is formed by the second lens, wherein the first virtual image (I) is formed between the second focal point (F) and the first lens, the second focal point (F) is on a side opposite to the light source side relative to a predetermined focal position f', and at least either of a light entry surface or a light exit surface of the first lens or the second lens includes a non-revolution surface (SO) as a lens surface, and a plurality of boundary lines (B-B) whose curvatures vary discontinuously are provided in the non-revolution surface.

A backlight system () includes a light emitting section () and an imaging optical system. The imaging optical system includes a first microlens array (MLA) and a second microlens array (MLA). The lenses (A) separates the beams of light emitted from the light emitting section () by RGB, and causes them to be converged at a pitch same as a pitch at which the picture elements are arrayed. The lenses (A) are provided in one-to-one correspondence to the picture elements such that the lenses (A) have their respective focal points at positions onto which beams of light having passed through the lenses (A) are converged. The lenses (A) thus deflect the beams of light which have passed through the lenses (A) in a substantially vertical direction with respect to the display surface of the liquid crystal panel.

Backlight system and LCD device using the same

Growing community of inventors

Sendai, Japan

Katsunori Ehara