A plane-shaped lighting device has a light-directing plate and a light source that is placed in contact with or in the proximity of the light-incident surface of the light-directing plate, and the light source is constituted of a plurality of LED lamps each of which has an LED chip for emitting light and a semispherical lens for directing the light from the LED chip into the light-directing plate. Here, the distance from the LED chip to the top of the semispherical lens is set to be 1.8 times as long as the radius of curvature of the semispherical lens. This arrangement allows the light emitted from the LED chip to be efficiently incident on the light-incident surface of the light-directing plate, thereby improving the light-incidence efficiency to the light-directing plate. Further, the application of this plane-shaped lighting device to display devices makes it possible to improve the efficiency of light utilization, and consequently to provide thinner display devices with high visibility.
This application is a divisional of Application No. 08/652,304, filed on May 23, 1996, now U.S. Pat. No. 5,786,665 issued Jul. 28, 1998 the entire contents of which are hereby incorporated by reference.
An LED area-light source module used for an LCD. A metal housing constituting a flat base, a bending portion, and at least one raised portion, in which the bending portion is an extension of the flat base and the overlapping portion between the bending portion and the flat base serves as a lying space. An LED circuit board is assembled into the lying space and has a plurality of chips, at least one connecting pad and at least one concave portion. An optical plate module is assembled on the flat base of the metal housing. At least one wire has one end welded on the connecting pad and the other end connected to a power supply. An edge between the exposed portion and the unexposed portion of the wire is installed on the bottom side of the concave portion.
In this surface light source device, light is incident from a plurality of point light sources 2 arranged on a one side end surface of a light guide plate 1, is reflected on a light reflecting surface 11 on a rear surface of the light guide plate 1, and is emitted from a front surface of the light guide plate 1. The point light sources 2 comprise white light emitting diode elements. Two white light emitting diode elements out of six of the white light emitting diode elements having chromaticity outermost from a center of an aimed chromaticity range in opposite hue directions are arranged in an approximately center of a group of the white diode elements.
A semiconductor light emitting apparatus comprises: a semiconductor light emitting device; resin that seals the semiconductor light emitting device; and antireflective coating provided on a surface of the resin. The antireflective coating is made of material having an intermediate refractive index between the refractive index of the resin and the refractive index of air.
A light source and an original reading device are provided in which light can be emitted uniformly and with a low loss of light amount, by a minimum required number of light emitting elements. A surface of a substrate, at which surface LED elements are disposed, is covered with a resist film having high reflectance, such as a white resist film. Light emitted toward the substrate from the LED elements is reflected toward a photographic film (toward a side of the LED elements opposite a substrate side of the LED elements). In this way, at an LED light source, almost all of light emitted from the LED elements can be emitted toward the photographic film. A diffusion box is disposed so as to surround a periphery of the LED light source. Due to a light reflection diffusion plate of the diffusion box, light, which is emitted from the LED light source and enters into the diffusion box, is guided toward the photographic film while being diffused and reflected. In this way, the light is guided while being collected, without a loss in an amount of light incident from the LED light source. Non-uniformity of a light amount distribution can be corrected even more (non-uniformity of a light amount can be reduced).
An LED is mounted on a circuit substrate, the LED is encapsulated by a transparent resin layer. A reflection layer is provided on the resin layer for reflecting and transmitting lights emitted from the LED.
