Abstract: A liquid ejection head includes an element substrate, an electric wiring board, a cover member, and a support member having a first through hole, a second through hole, and a support surface. The element substrate includes an ejection port and a pressure chamber to supply liquid to the ejection port. The cover member is joined to the support surface with a first adhesive. The support member supports the element substrate and the electric wiring board on the support surface. The first through hole serves as a flow passage through which the liquid is supplied to the pressure chamber and the second through hole opens in the support surface. The first adhesive is disposed in an outer peripheral region of the support surface of the support member. A space surrounded by the cover member, the support member, and the first adhesive communicates with the second through hole.

Abstract: Provided is a light source device capable of minimizing or preventing a decrease in amount of light emitted from portions in the vicinity of a locking member of a light guide plate, and capable of making intensity distribution in a plane of light emitted from the light guide plate uniform. The light source device includes a light guide plate 13 (13a, 13b) including a locking member 131a, 131b for disposition and fixing that is disposed on a peripheral portion of the light guide plate or disposed in a vicinity of the peripheral portion, and a light source (15a) capable of projecting light onto the peripheral portion, wherein the light that is projected from the light source onto portions of the light guiding plate, the portions being in the vicinity of the locking member, is higher in intensity than the light projected onto the other portions of the light guiding plate.

Abstract: It is an object of the present invention to provide a lighting device with improved light use efficiency.

Abstract: A backlight unit 12 includes LEDs 16, light guide plates 18 and air layers AR1 having a reflective index lower than the light guide member. Each of the light guide plates 18 includes a light entrance surface 34 provided to face the LED 16 and that light from the LED 16 enters, and a light exit surface 36 provided to be parallel to an arrangement direction in which the LED 16 and the light entrance surface 34 are arranged and through which the light exits. The light guide members 18 are arranged in a vertical direction that is the arrangement direction and in a horizontal direction that is a direction parallel to the light exit surface 36 and perpendicular to the arrangement direction. The air layer AR1 is provided between the horizontally adjacent light guide members 18.