Sharp Kabushiki Kaisha Corporation

Tohoku University

Yoshihiro Hashimoto

Yutaka Ishii

Tatsuo Uchida

Takahiro Ishinabe

Tohru Kawakami

Yoshito Suzuki

Shuichi Kozaki

Shoichi Ishihara

Baku Katagiri

Katsunori Ehara

Kazuo Sekiya

Yoshitaka Yamamoto

Yasuhisa Itoh

Masahiro Nishizawa

Kozo Nakamura

Toshiki Matsuoka

David James Montgomery

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

A backlight system includes: a light-emitting section () having a plurality of light sources that emit beams of light at different dominant wavelengths from one another; and an imaging optical system () including a plurality of microlenses () that focus beams of light emitted from the light-emitting section (), the backlight system irradiating a liquid crystal panel with beams of light having passed through the imaging optical system (), the liquid crystal panel including a plurality of pixels arrayed at a predetermined pitch from each other, on the assumption that the pitch at which the pixels are arrayed is denoted as P and the imaging optical system () has an imaging magnification of (1/n), the light sources () being arrayed at a pitch (P) given as P=n&#xd7;P, the microlenses () being arrayed at a pitch (P) given as P=(n/(n+1))&#xd7;P.

Backlight system and liquid crystal display device using the same

A thin backlight system includes: a light emitting section emitting lights that have different dominant wavelengths; and a plurality of light transmitting portions, the thin backlight system deflecting the lights and then converging the lights on the plurality of light transmitting portions. The thin backlight system further includes: an imaging optical system provided to face surfaces, of the plurality of light transmitting portions, on which the lights are converged. The imaging optical system including a plurality of identical lenses arranged in a vertical and/or a horizontal direction at a pitch determined by multiplying a pitch at which the plurality of light transmitting portions are arranged in a vertical and/or a horizontal direction by the number of types of the different dominant wavelengths and being configured to converge the lights from the light emitting section on light transmitting portions to which the different dominant wavelengths of the lights correspond.

Thin backlight system and liquid crystal display device using the same

Surface light source device includes: point light sources (); light guide plate () having (i) two end parts in length direction, one of which serves as incident surface (), and (ii) two end parts in thickness direction which serve as exit surface () and back surface (), light guide plate () directing light, emitted from point light sources (), incident on incident surface (), so as to cause light to exit from substantially entire area of exit surface (); and reflector () which reflects, toward incident surface (), part of light which is emitted from point light sources () and is then reflected from incident surface (). Incident surface () has elliptic arc () which is concave part having surface shape along elliptic arc identical to elliptic arc which is part of ellipse () having two focal points corresponding to point light sources () and reflector (). Point light sources () and reflector () are provided on ellipse focal point lines (and) obtained by moving two focal points in width direction of light guide plate ().

Surface light source device

A dichroic filter column () is provided on an incident surface (). At least one of two end parts of a light guide plate () in a thickness direction is divided into a plurality of light guide paths (), in a width direction of the light guide plate () by a plurality of cutout grooves (). Portions of the plurality of light guide paths () on an incident surface () side are aligned in accordance with positions of a plurality of dichroic filters (), respectively. The plurality of dichroic filters () are elements of the dichroic filter column ().

Growing community of inventors

Osaka, Japan

Yoshihiro Hashimoto